fe-connect.c File Reference

#include "postgres_fe.h"
#include <sys/stat.h>
#include <fcntl.h>
#include <ctype.h>
#include <netdb.h>
#include <time.h>
#include <unistd.h>
#include "common/ip.h"
#include "common/link-canary.h"
#include "common/scram-common.h"
#include "common/string.h"
#include "fe-auth.h"
#include "libpq-fe.h"
#include "libpq-int.h"
#include "mb/pg_wchar.h"
#include "pg_config_paths.h"
#include "port/pg_bswap.h"
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>

Include dependency graph for fe-connect.c:

Go to the source code of this file.

Data Structures
struct	_internalPQconninfoOption

Macros
#define	PGPASSFILE   ".pgpass"
#define	ERRCODE_APPNAME_UNKNOWN   "42704"
#define	ERRCODE_INVALID_PASSWORD   "28P01"
#define	ERRCODE_CANNOT_CONNECT_NOW   "57P03"
#define	DefaultHost   "localhost"
#define	DefaultOption   ""
#define	DefaultChannelBinding   "disable"
#define	DefaultTargetSessionAttrs   "any"
#define	DefaultSSLMode   "disable"
#define	DefaultGSSMode   "disable"

Typedefs
typedef struct _internalPQconninfoOption	internalPQconninfoOption

Functions
static bool	connectOptions1 (PGconn *conn, const char *conninfo)
static bool	connectOptions2 (PGconn *conn)
static int	connectDBStart (PGconn *conn)
static int	connectDBComplete (PGconn *conn)
static PGPing	internal_ping (PGconn *conn)
static PGconn *	makeEmptyPGconn (void)
static void	pqFreeCommandQueue (PGcmdQueueEntry *queue)
static bool	fillPGconn (PGconn *conn, PQconninfoOption *connOptions)
static void	freePGconn (PGconn *conn)
static void	closePGconn (PGconn *conn)
static void	release_conn_addrinfo (PGconn *conn)
static void	sendTerminateConn (PGconn *conn)
static PQconninfoOption *	conninfo_init (PQExpBuffer errorMessage)
static PQconninfoOption *	parse_connection_string (const char *connstr, PQExpBuffer errorMessage, bool use_defaults)
static int	uri_prefix_length (const char *connstr)
static bool	recognized_connection_string (const char *connstr)
static PQconninfoOption *	conninfo_parse (const char *conninfo, PQExpBuffer errorMessage, bool use_defaults)
static PQconninfoOption *	conninfo_array_parse (const char *const *keywords, const char *const *values, PQExpBuffer errorMessage, bool use_defaults, int expand_dbname)
static bool	conninfo_add_defaults (PQconninfoOption *options, PQExpBuffer errorMessage)
static PQconninfoOption *	conninfo_uri_parse (const char *uri, PQExpBuffer errorMessage, bool use_defaults)
static bool	conninfo_uri_parse_options (PQconninfoOption *options, const char *uri, PQExpBuffer errorMessage)
static bool	conninfo_uri_parse_params (char *params, PQconninfoOption *connOptions, PQExpBuffer errorMessage)
static char *	conninfo_uri_decode (const char *str, PQExpBuffer errorMessage)
static bool	get_hexdigit (char digit, int *value)
static const char *	conninfo_getval (PQconninfoOption *connOptions, const char *keyword)
static PQconninfoOption *	conninfo_storeval (PQconninfoOption *connOptions, const char *keyword, const char *value, PQExpBuffer errorMessage, bool ignoreMissing, bool uri_decode)
static PQconninfoOption *	conninfo_find (PQconninfoOption *connOptions, const char *keyword)
static void	defaultNoticeReceiver (void *arg, const PGresult *res)
static void	defaultNoticeProcessor (void *arg, const char *message)
static int	parseServiceInfo (PQconninfoOption *options, PQExpBuffer errorMessage)
static int	parseServiceFile (const char *serviceFile, const char *service, PQconninfoOption *options, PQExpBuffer errorMessage, bool *group_found)
static char *	pwdfMatchesString (char *buf, const char *token)
static char *	passwordFromFile (const char *hostname, const char *port, const char *dbname, const char *username, const char *pgpassfile)
static void	pgpassfileWarning (PGconn *conn)
static void	default_threadlock (int acquire)
static bool	sslVerifyProtocolVersion (const char *version)
static bool	sslVerifyProtocolRange (const char *min, const char *max)
void	pqDropConnection (PGconn *conn, bool flushInput)
static void	pqDropServerData (PGconn *conn)
PGconn *	PQconnectdbParams (const char *const *keywords, const char *const *values, int expand_dbname)
PGPing	PQpingParams (const char *const *keywords, const char *const *values, int expand_dbname)
PGconn *	PQconnectdb (const char *conninfo)
PGPing	PQping (const char *conninfo)
PGconn *	PQconnectStartParams (const char *const *keywords, const char *const *values, int expand_dbname)
PGconn *	PQconnectStart (const char *conninfo)
static int	count_comma_separated_elems (const char *input)
static char *	parse_comma_separated_list (char **startptr, bool *more)
PQconninfoOption *	PQconndefaults (void)
PGconn *	PQsetdbLogin (const char *pghost, const char *pgport, const char *pgoptions, const char *pgtty, const char *dbName, const char *login, const char *pwd)
static int	connectNoDelay (PGconn *conn)
static void	getHostaddr (PGconn *conn, char *host_addr, int host_addr_len)
static void	emitHostIdentityInfo (PGconn *conn, const char *host_addr)
static void	connectFailureMessage (PGconn *conn, int errorno)
static int	useKeepalives (PGconn *conn)
static bool	parse_int_param (const char *value, int *result, PGconn *conn, const char *context)
static int	setKeepalivesIdle (PGconn *conn)
static int	setKeepalivesInterval (PGconn *conn)
static int	setKeepalivesCount (PGconn *conn)
static int	setTCPUserTimeout (PGconn *conn)
PostgresPollingStatusType	PQconnectPoll (PGconn *conn)
void	PQfinish (PGconn *conn)
void	PQreset (PGconn *conn)
int	PQresetStart (PGconn *conn)
PostgresPollingStatusType	PQresetPoll (PGconn *conn)
PGcancel *	PQgetCancel (PGconn *conn)
void	PQfreeCancel (PGcancel *cancel)
static bool	optional_setsockopt (int fd, int protoid, int optid, int value)
int	PQcancel (PGcancel *cancel, char *errbuf, int errbufsize)
int	PQrequestCancel (PGconn *conn)
int	pqPacketSend (PGconn *conn, char pack_type, const void *buf, size_t buf_len)
PQconninfoOption *	PQconninfoParse (const char *conninfo, char **errmsg)
PQconninfoOption *	PQconninfo (PGconn *conn)
void	PQconninfoFree (PQconninfoOption *connOptions)
char *	PQdb (const PGconn *conn)
char *	PQuser (const PGconn *conn)
char *	PQpass (const PGconn *conn)
char *	PQhost (const PGconn *conn)
char *	PQhostaddr (const PGconn *conn)
char *	PQport (const PGconn *conn)
char *	PQtty (const PGconn *conn)
char *	PQoptions (const PGconn *conn)
ConnStatusType	PQstatus (const PGconn *conn)
PGTransactionStatusType	PQtransactionStatus (const PGconn *conn)
const char *	PQparameterStatus (const PGconn *conn, const char *paramName)
int	PQprotocolVersion (const PGconn *conn)
int	PQserverVersion (const PGconn *conn)
char *	PQerrorMessage (const PGconn *conn)
int	PQsocket (const PGconn *conn)
int	PQbackendPID (const PGconn *conn)
PGpipelineStatus	PQpipelineStatus (const PGconn *conn)
int	PQconnectionNeedsPassword (const PGconn *conn)
int	PQconnectionUsedPassword (const PGconn *conn)
int	PQclientEncoding (const PGconn *conn)
int	PQsetClientEncoding (PGconn *conn, const char *encoding)
PGVerbosity	PQsetErrorVerbosity (PGconn *conn, PGVerbosity verbosity)
PGContextVisibility	PQsetErrorContextVisibility (PGconn *conn, PGContextVisibility show_context)
PQnoticeReceiver	PQsetNoticeReceiver (PGconn *conn, PQnoticeReceiver proc, void *arg)
PQnoticeProcessor	PQsetNoticeProcessor (PGconn *conn, PQnoticeProcessor proc, void *arg)
bool	pqGetHomeDirectory (char *buf, int bufsize)
pgthreadlock_t	PQregisterThreadLock (pgthreadlock_t newhandler)

Variables
static const internalPQconninfoOption	PQconninfoOptions []
static const PQEnvironmentOption	EnvironmentOptions []
static const char	uri_designator [] = "postgresql://"
static const char	short_uri_designator [] = "postgres://"
pgthreadlock_t	pg_g_threadlock = default_threadlock

Macro Definition Documentation

DefaultChannelBinding

#define DefaultChannelBinding   "disable"

Definition at line 123 of file fe-connect.c.

DefaultGSSMode

#define DefaultGSSMode   "disable"

Definition at line 135 of file fe-connect.c.

DefaultHost

#define DefaultHost   "localhost"

Definition at line 118 of file fe-connect.c.

DefaultOption

#define DefaultOption   ""

Definition at line 119 of file fe-connect.c.

DefaultSSLMode

#define DefaultSSLMode   "disable"

Definition at line 129 of file fe-connect.c.

DefaultTargetSessionAttrs

#define DefaultTargetSessionAttrs   "any"

Definition at line 125 of file fe-connect.c.

ERRCODE_APPNAME_UNKNOWN

#define ERRCODE_APPNAME_UNKNOWN   "42704"

Definition at line 88 of file fe-connect.c.

ERRCODE_CANNOT_CONNECT_NOW

#define ERRCODE_CANNOT_CONNECT_NOW   "57P03"

Definition at line 93 of file fe-connect.c.

ERRCODE_INVALID_PASSWORD

#define ERRCODE_INVALID_PASSWORD   "28P01"

Definition at line 91 of file fe-connect.c.

PGPASSFILE

#define PGPASSFILE   ".pgpass"

Definition at line 77 of file fe-connect.c.

Typedef Documentation

internalPQconninfoOption

typedef struct _internalPQconninfoOption internalPQconninfoOption

Function Documentation

closePGconn()

static void closePGconn ( PGconn *  conn )

static

Definition at line 4091 of file fe-connect.c.

{
    /*
     * If possible, send Terminate message to close the connection politely.
     */
    sendTerminateConn(conn);
 
    /*
     * Must reset the blocking status so a possible reconnect will work.
     *
     * Don't call PQsetnonblocking() because it will fail if it's unable to
     * flush the connection.
     */
    conn->nonblocking = false;
 
    /*
     * Close the connection, reset all transient state, flush I/O buffers.
     * Note that this includes clearing conn's error state; we're no longer
     * interested in any failures associated with the old connection, and we
     * want a clean slate for any new connection attempt.
     */
    pqDropConnection(conn, true);
    conn->status = CONNECTION_BAD;  /* Well, not really _bad_ - just absent */
    conn->asyncStatus = PGASYNC_IDLE;
    conn->xactStatus = PQTRANS_IDLE;
    conn->pipelineStatus = PQ_PIPELINE_OFF;
    pqClearAsyncResult(conn);   /* deallocate result */
    pqClearConnErrorState(conn);
    release_conn_addrinfo(conn);
 
    /* Reset all state obtained from server, too */
    pqDropServerData(conn);
}

References pg_conn::asyncStatus, conn, CONNECTION_BAD, pg_conn::nonblocking, PGASYNC_IDLE, pg_conn::pipelineStatus, PQ_PIPELINE_OFF, pqClearAsyncResult(), pqClearConnErrorState, pqDropConnection(), pqDropServerData(), PQTRANS_IDLE, release_conn_addrinfo(), sendTerminateConn(), pg_conn::status, and pg_conn::xactStatus.

Referenced by PQfinish(), PQreset(), and PQresetStart().

connectDBComplete()

static int connectDBComplete ( PGconn *  conn )

static

Definition at line 2074 of file fe-connect.c.

{
    PostgresPollingStatusType flag = PGRES_POLLING_WRITING;
    time_t      finish_time = ((time_t) -1);
    int         timeout = 0;
    int         last_whichhost = -2;    /* certainly different from whichhost */
    struct addrinfo *last_addr_cur = NULL;
 
    if (conn == NULL || conn->status == CONNECTION_BAD)
        return 0;
 
    /*
     * Set up a time limit, if connect_timeout isn't zero.
     */
    if (conn->connect_timeout != NULL)
    {
        if (!parse_int_param(conn->connect_timeout, &timeout, conn,
                             "connect_timeout"))
        {
            /* mark the connection as bad to report the parsing failure */
            conn->status = CONNECTION_BAD;
            return 0;
        }
 
        if (timeout > 0)
        {
            /*
             * Rounding could cause connection to fail unexpectedly quickly;
             * to prevent possibly waiting hardly-at-all, insist on at least
             * two seconds.
             */
            if (timeout < 2)
                timeout = 2;
        }
        else                    /* negative means 0 */
            timeout = 0;
    }
 
    for (;;)
    {
        int         ret = 0;
 
        /*
         * (Re)start the connect_timeout timer if it's active and we are
         * considering a different host than we were last time through.  If
         * we've already succeeded, though, needn't recalculate.
         */
        if (flag != PGRES_POLLING_OK &&
            timeout > 0 &&
            (conn->whichhost != last_whichhost ||
             conn->addr_cur != last_addr_cur))
        {
            finish_time = time(NULL) + timeout;
            last_whichhost = conn->whichhost;
            last_addr_cur = conn->addr_cur;
        }
 
        /*
         * Wait, if necessary.  Note that the initial state (just after
         * PQconnectStart) is to wait for the socket to select for writing.
         */
        switch (flag)
        {
            case PGRES_POLLING_OK:
                return 1;       /* success! */
 
            case PGRES_POLLING_READING:
                ret = pqWaitTimed(1, 0, conn, finish_time);
                if (ret == -1)
                {
                    /* hard failure, eg select() problem, aborts everything */
                    conn->status = CONNECTION_BAD;
                    return 0;
                }
                break;
 
            case PGRES_POLLING_WRITING:
                ret = pqWaitTimed(0, 1, conn, finish_time);
                if (ret == -1)
                {
                    /* hard failure, eg select() problem, aborts everything */
                    conn->status = CONNECTION_BAD;
                    return 0;
                }
                break;
 
            default:
                /* Just in case we failed to set it in PQconnectPoll */
                conn->status = CONNECTION_BAD;
                return 0;
        }
 
        if (ret == 1)           /* connect_timeout elapsed */
        {
            /*
             * Give up on current server/address, try the next one.
             */
            conn->try_next_addr = true;
            conn->status = CONNECTION_NEEDED;
        }
 
        /*
         * Now try to advance the state machine.
         */
        flag = PQconnectPoll(conn);
    }
}

References pg_conn::addr_cur, conn, pg_conn::connect_timeout, CONNECTION_BAD, CONNECTION_NEEDED, flag(), parse_int_param(), PGRES_POLLING_OK, PGRES_POLLING_READING, PGRES_POLLING_WRITING, PQconnectPoll(), pqWaitTimed(), pg_conn::status, pg_conn::try_next_addr, and pg_conn::whichhost.

Referenced by internal_ping(), PQconnectdb(), PQconnectdbParams(), PQreset(), and PQsetdbLogin().

connectDBStart()

static int connectDBStart ( PGconn *  conn )

static

Definition at line 2004 of file fe-connect.c.

{
    if (!conn)
        return 0;
 
    if (!conn->options_valid)
        goto connect_errReturn;
 
    /*
     * Check for bad linking to backend-internal versions of src/common
     * functions (see comments in link-canary.c for the reason we need this).
     * Nobody but developers should see this message, so we don't bother
     * translating it.
     */
    if (!pg_link_canary_is_frontend())
    {
        appendPQExpBufferStr(&conn->errorMessage,
                             "libpq is incorrectly linked to backend functions\n");
        goto connect_errReturn;
    }
 
    /* Ensure our buffers are empty */
    conn->inStart = conn->inCursor = conn->inEnd = 0;
    conn->outCount = 0;
 
    /*
     * Set up to try to connect to the first host.  (Setting whichhost = -1 is
     * a bit of a cheat, but PQconnectPoll will advance it to 0 before
     * anything else looks at it.)
     */
    conn->whichhost = -1;
    conn->try_next_addr = false;
    conn->try_next_host = true;
    conn->status = CONNECTION_NEEDED;
 
    /* Also reset the target_server_type state if needed */
    if (conn->target_server_type == SERVER_TYPE_PREFER_STANDBY_PASS2)
        conn->target_server_type = SERVER_TYPE_PREFER_STANDBY;
 
    /*
     * The code for processing CONNECTION_NEEDED state is in PQconnectPoll(),
     * so that it can easily be re-executed if needed again during the
     * asynchronous startup process.  However, we must run it once here,
     * because callers expect a success return from this routine to mean that
     * we are in PGRES_POLLING_WRITING connection state.
     */
    if (PQconnectPoll(conn) == PGRES_POLLING_WRITING)
        return 1;
 
connect_errReturn:
 
    /*
     * If we managed to open a socket, close it immediately rather than
     * waiting till PQfinish.  (The application cannot have gotten the socket
     * from PQsocket yet, so this doesn't risk breaking anything.)
     */
    pqDropConnection(conn, true);
    conn->status = CONNECTION_BAD;
    return 0;
}

References appendPQExpBufferStr(), conn, CONNECTION_BAD, CONNECTION_NEEDED, pg_conn::errorMessage, pg_conn::inCursor, pg_conn::inEnd, pg_conn::inStart, pg_conn::options_valid, pg_conn::outCount, pg_link_canary_is_frontend(), PGRES_POLLING_WRITING, PQconnectPoll(), pqDropConnection(), SERVER_TYPE_PREFER_STANDBY, SERVER_TYPE_PREFER_STANDBY_PASS2, pg_conn::status, pg_conn::target_server_type, pg_conn::try_next_addr, pg_conn::try_next_host, and pg_conn::whichhost.

Referenced by PQconnectStart(), PQconnectStartParams(), PQreset(), PQresetStart(), and PQsetdbLogin().

connectFailureMessage()

static void connectFailureMessage ( PGconn *  conn, int  errorno  )

static

Definition at line 1715 of file fe-connect.c.

{
    char        sebuf[PG_STRERROR_R_BUFLEN];
 
    appendPQExpBuffer(&conn->errorMessage,
                      "%s\n",
                      SOCK_STRERROR(errorno, sebuf, sizeof(sebuf)));
 
    if (conn->raddr.addr.ss_family == AF_UNIX)
        libpq_append_conn_error(conn, "\tIs the server running locally and accepting connections on that socket?");
    else
        libpq_append_conn_error(conn, "\tIs the server running on that host and accepting TCP/IP connections?");
}

References SockAddr::addr, appendPQExpBuffer(), conn, pg_conn::errorMessage, libpq_append_conn_error(), PG_STRERROR_R_BUFLEN, pg_conn::raddr, and SOCK_STRERROR.

Referenced by PQconnectPoll().

connectNoDelay()

static int connectNoDelay ( PGconn *  conn )

static

Definition at line 1600 of file fe-connect.c.

{
#ifdef  TCP_NODELAY
    int         on = 1;
 
    if (setsockopt(conn->sock, IPPROTO_TCP, TCP_NODELAY,
                   (char *) &on,
                   sizeof(on)) < 0)
    {
        char        sebuf[PG_STRERROR_R_BUFLEN];
 
        libpq_append_conn_error(conn, "could not set socket to TCP no delay mode: %s",
                           SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
        return 0;
    }
#endif
 
    return 1;
}

References conn, libpq_append_conn_error(), PG_STRERROR_R_BUFLEN, pg_conn::sock, SOCK_ERRNO, and SOCK_STRERROR.

Referenced by PQconnectPoll().

connectOptions1()

static bool connectOptions1 ( PGconn *  conn, const char *  conninfo  )

static

Definition at line 921 of file fe-connect.c.

{
    PQconninfoOption *connOptions;
 
    /*
     * Parse the conninfo string
     */
    connOptions = parse_connection_string(conninfo, &conn->errorMessage, true);
    if (connOptions == NULL)
    {
        conn->status = CONNECTION_BAD;
        /* errorMessage is already set */
        return false;
    }
 
    /*
     * Move option values into conn structure
     */
    if (!fillPGconn(conn, connOptions))
    {
        conn->status = CONNECTION_BAD;
        PQconninfoFree(connOptions);
        return false;
    }
 
    /*
     * Free the option info - all is in conn now
     */
    PQconninfoFree(connOptions);
 
    return true;
}

References conn, CONNECTION_BAD, pg_conn::errorMessage, fillPGconn(), parse_connection_string(), PQconninfoFree(), and pg_conn::status.

Referenced by PQconnectStart(), and PQsetdbLogin().

connectOptions2()

static bool connectOptions2 ( PGconn *  conn )

static

Definition at line 1019 of file fe-connect.c.

{
    int         i;
 
    /*
     * Allocate memory for details about each host to which we might possibly
     * try to connect.  For that, count the number of elements in the hostaddr
     * or host options.  If neither is given, assume one host.
     */
    conn->whichhost = 0;
    if (conn->pghostaddr && conn->pghostaddr[0] != '\0')
        conn->nconnhost = count_comma_separated_elems(conn->pghostaddr);
    else if (conn->pghost && conn->pghost[0] != '\0')
        conn->nconnhost = count_comma_separated_elems(conn->pghost);
    else
        conn->nconnhost = 1;
    conn->connhost = (pg_conn_host *)
        calloc(conn->nconnhost, sizeof(pg_conn_host));
    if (conn->connhost == NULL)
        goto oom_error;
 
    /*
     * We now have one pg_conn_host structure per possible host.  Fill in the
     * host and hostaddr fields for each, by splitting the parameter strings.
     */
    if (conn->pghostaddr != NULL && conn->pghostaddr[0] != '\0')
    {
        char       *s = conn->pghostaddr;
        bool        more = true;
 
        for (i = 0; i < conn->nconnhost && more; i++)
        {
            conn->connhost[i].hostaddr = parse_comma_separated_list(&s, &more);
            if (conn->connhost[i].hostaddr == NULL)
                goto oom_error;
        }
 
        /*
         * If hostaddr was given, the array was allocated according to the
         * number of elements in the hostaddr list, so it really should be the
         * right size.
         */
        Assert(!more);
        Assert(i == conn->nconnhost);
    }
 
    if (conn->pghost != NULL && conn->pghost[0] != '\0')
    {
        char       *s = conn->pghost;
        bool        more = true;
 
        for (i = 0; i < conn->nconnhost && more; i++)
        {
            conn->connhost[i].host = parse_comma_separated_list(&s, &more);
            if (conn->connhost[i].host == NULL)
                goto oom_error;
        }
 
        /* Check for wrong number of host items. */
        if (more || i != conn->nconnhost)
        {
            conn->status = CONNECTION_BAD;
            libpq_append_conn_error(conn, "could not match %d host names to %d hostaddr values",
                               count_comma_separated_elems(conn->pghost), conn->nconnhost);
            return false;
        }
    }
 
    /*
     * Now, for each host slot, identify the type of address spec, and fill in
     * the default address if nothing was given.
     */
    for (i = 0; i < conn->nconnhost; i++)
    {
        pg_conn_host *ch = &conn->connhost[i];
 
        if (ch->hostaddr != NULL && ch->hostaddr[0] != '\0')
            ch->type = CHT_HOST_ADDRESS;
        else if (ch->host != NULL && ch->host[0] != '\0')
        {
            ch->type = CHT_HOST_NAME;
            if (is_unixsock_path(ch->host))
                ch->type = CHT_UNIX_SOCKET;
        }
        else
        {
            free(ch->host);
 
            /*
             * This bit selects the default host location.  If you change
             * this, see also pg_regress.
             */
            if (DEFAULT_PGSOCKET_DIR[0])
            {
                ch->host = strdup(DEFAULT_PGSOCKET_DIR);
                ch->type = CHT_UNIX_SOCKET;
            }
            else
            {
                ch->host = strdup(DefaultHost);
                ch->type = CHT_HOST_NAME;
            }
            if (ch->host == NULL)
                goto oom_error;
        }
    }
 
    /*
     * Next, work out the port number corresponding to each host name.
     *
     * Note: unlike the above for host names, this could leave the port fields
     * as null or empty strings.  We will substitute DEF_PGPORT whenever we
     * read such a port field.
     */
    if (conn->pgport != NULL && conn->pgport[0] != '\0')
    {
        char       *s = conn->pgport;
        bool        more = true;
 
        for (i = 0; i < conn->nconnhost && more; i++)
        {
            conn->connhost[i].port = parse_comma_separated_list(&s, &more);
            if (conn->connhost[i].port == NULL)
                goto oom_error;
        }
 
        /*
         * If exactly one port was given, use it for every host.  Otherwise,
         * there must be exactly as many ports as there were hosts.
         */
        if (i == 1 && !more)
        {
            for (i = 1; i < conn->nconnhost; i++)
            {
                conn->connhost[i].port = strdup(conn->connhost[0].port);
                if (conn->connhost[i].port == NULL)
                    goto oom_error;
            }
        }
        else if (more || i != conn->nconnhost)
        {
            conn->status = CONNECTION_BAD;
            libpq_append_conn_error(conn, "could not match %d port numbers to %d hosts",
                               count_comma_separated_elems(conn->pgport), conn->nconnhost);
            return false;
        }
    }
 
    /*
     * If user name was not given, fetch it.  (Most likely, the fetch will
     * fail, since the only way we get here is if pg_fe_getauthname() failed
     * during conninfo_add_defaults().  But now we want an error message.)
     */
    if (conn->pguser == NULL || conn->pguser[0] == '\0')
    {
        free(conn->pguser);
        conn->pguser = pg_fe_getauthname(&conn->errorMessage);
        if (!conn->pguser)
        {
            conn->status = CONNECTION_BAD;
            return false;
        }
    }
 
    /*
     * If database name was not given, default it to equal user name
     */
    if (conn->dbName == NULL || conn->dbName[0] == '\0')
    {
        free(conn->dbName);
        conn->dbName = strdup(conn->pguser);
        if (!conn->dbName)
            goto oom_error;
    }
 
    /*
     * If password was not given, try to look it up in password file.  Note
     * that the result might be different for each host/port pair.
     */
    if (conn->pgpass == NULL || conn->pgpass[0] == '\0')
    {
        /* If password file wasn't specified, use ~/PGPASSFILE */
        if (conn->pgpassfile == NULL || conn->pgpassfile[0] == '\0')
        {
            char        homedir[MAXPGPATH];
 
            if (pqGetHomeDirectory(homedir, sizeof(homedir)))
            {
                free(conn->pgpassfile);
                conn->pgpassfile = malloc(MAXPGPATH);
                if (!conn->pgpassfile)
                    goto oom_error;
                snprintf(conn->pgpassfile, MAXPGPATH, "%s/%s",
                         homedir, PGPASSFILE);
            }
        }
 
        if (conn->pgpassfile != NULL && conn->pgpassfile[0] != '\0')
        {
            for (i = 0; i < conn->nconnhost; i++)
            {
                /*
                 * Try to get a password for this host from file.  We use host
                 * for the hostname search key if given, else hostaddr (at
                 * least one of them is guaranteed nonempty by now).
                 */
                const char *pwhost = conn->connhost[i].host;
 
                if (pwhost == NULL || pwhost[0] == '\0')
                    pwhost = conn->connhost[i].hostaddr;
 
                conn->connhost[i].password =
                    passwordFromFile(pwhost,
                                     conn->connhost[i].port,
                                     conn->dbName,
                                     conn->pguser,
                                     conn->pgpassfile);
            }
        }
    }
 
    /*
     * validate channel_binding option
     */
    if (conn->channel_binding)
    {
        if (strcmp(conn->channel_binding, "disable") != 0
            && strcmp(conn->channel_binding, "prefer") != 0
            && strcmp(conn->channel_binding, "require") != 0)
        {
            conn->status = CONNECTION_BAD;
            libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
                               "channel_binding", conn->channel_binding);
            return false;
        }
    }
    else
    {
        conn->channel_binding = strdup(DefaultChannelBinding);
        if (!conn->channel_binding)
            goto oom_error;
    }
 
    /*
     * validate sslmode option
     */
    if (conn->sslmode)
    {
        if (strcmp(conn->sslmode, "disable") != 0
            && strcmp(conn->sslmode, "allow") != 0
            && strcmp(conn->sslmode, "prefer") != 0
            && strcmp(conn->sslmode, "require") != 0
            && strcmp(conn->sslmode, "verify-ca") != 0
            && strcmp(conn->sslmode, "verify-full") != 0)
        {
            conn->status = CONNECTION_BAD;
            libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
                               "sslmode", conn->sslmode);
            return false;
        }
 
#ifndef USE_SSL
        switch (conn->sslmode[0])
        {
            case 'a':           /* "allow" */
            case 'p':           /* "prefer" */
 
                /*
                 * warn user that an SSL connection will never be negotiated
                 * since SSL was not compiled in?
                 */
                break;
 
            case 'r':           /* "require" */
            case 'v':           /* "verify-ca" or "verify-full" */
                conn->status = CONNECTION_BAD;
                libpq_append_conn_error(conn, "sslmode value \"%s\" invalid when SSL support is not compiled in",
                                   conn->sslmode);
                return false;
        }
#endif
    }
    else
    {
        conn->sslmode = strdup(DefaultSSLMode);
        if (!conn->sslmode)
            goto oom_error;
    }
 
    /*
     * Validate TLS protocol versions for ssl_min_protocol_version and
     * ssl_max_protocol_version.
     */
    if (!sslVerifyProtocolVersion(conn->ssl_min_protocol_version))
    {
        conn->status = CONNECTION_BAD;
        libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
                           "ssl_min_protocol_version",
                           conn->ssl_min_protocol_version);
        return false;
    }
    if (!sslVerifyProtocolVersion(conn->ssl_max_protocol_version))
    {
        conn->status = CONNECTION_BAD;
        libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
                           "ssl_max_protocol_version",
                           conn->ssl_max_protocol_version);
        return false;
    }
 
    /*
     * Check if the range of SSL protocols defined is correct.  This is done
     * at this early step because this is independent of the SSL
     * implementation used, and this avoids unnecessary cycles with an
     * already-built SSL context when the connection is being established, as
     * it would be doomed anyway.
     */
    if (!sslVerifyProtocolRange(conn->ssl_min_protocol_version,
                                conn->ssl_max_protocol_version))
    {
        conn->status = CONNECTION_BAD;
        libpq_append_conn_error(conn, "invalid SSL protocol version range");
        return false;
    }
 
    /*
     * validate gssencmode option
     */
    if (conn->gssencmode)
    {
        if (strcmp(conn->gssencmode, "disable") != 0 &&
            strcmp(conn->gssencmode, "prefer") != 0 &&
            strcmp(conn->gssencmode, "require") != 0)
        {
            conn->status = CONNECTION_BAD;
            libpq_append_conn_error(conn, "invalid %s value: \"%s\"", "gssencmode", conn->gssencmode);
            return false;
        }
#ifndef ENABLE_GSS
        if (strcmp(conn->gssencmode, "require") == 0)
        {
            conn->status = CONNECTION_BAD;
            libpq_append_conn_error(conn, "gssencmode value \"%s\" invalid when GSSAPI support is not compiled in",
                               conn->gssencmode);
            return false;
        }
#endif
    }
    else
    {
        conn->gssencmode = strdup(DefaultGSSMode);
        if (!conn->gssencmode)
            goto oom_error;
    }
 
    /*
     * validate target_session_attrs option, and set target_server_type
     */
    if (conn->target_session_attrs)
    {
        if (strcmp(conn->target_session_attrs, "any") == 0)
            conn->target_server_type = SERVER_TYPE_ANY;
        else if (strcmp(conn->target_session_attrs, "read-write") == 0)
            conn->target_server_type = SERVER_TYPE_READ_WRITE;
        else if (strcmp(conn->target_session_attrs, "read-only") == 0)
            conn->target_server_type = SERVER_TYPE_READ_ONLY;
        else if (strcmp(conn->target_session_attrs, "primary") == 0)
            conn->target_server_type = SERVER_TYPE_PRIMARY;
        else if (strcmp(conn->target_session_attrs, "standby") == 0)
            conn->target_server_type = SERVER_TYPE_STANDBY;
        else if (strcmp(conn->target_session_attrs, "prefer-standby") == 0)
            conn->target_server_type = SERVER_TYPE_PREFER_STANDBY;
        else
        {
            conn->status = CONNECTION_BAD;
            libpq_append_conn_error(conn, "invalid %s value: \"%s\"",
                               "target_session_attrs",
                               conn->target_session_attrs);
            return false;
        }
    }
    else
        conn->target_server_type = SERVER_TYPE_ANY;
 
    /*
     * Resolve special "auto" client_encoding from the locale
     */
    if (conn->client_encoding_initial &&
        strcmp(conn->client_encoding_initial, "auto") == 0)
    {
        free(conn->client_encoding_initial);
        conn->client_encoding_initial = strdup(pg_encoding_to_char(pg_get_encoding_from_locale(NULL, true)));
        if (!conn->client_encoding_initial)
            goto oom_error;
    }
 
    /*
     * Only if we get this far is it appropriate to try to connect. (We need a
     * state flag, rather than just the boolean result of this function, in
     * case someone tries to PQreset() the PGconn.)
     */
    conn->options_valid = true;
 
    return true;
 
oom_error:
    conn->status = CONNECTION_BAD;
    libpq_append_conn_error(conn, "out of memory");
    return false;
}

References Assert(), calloc, pg_conn::channel_binding, CHT_HOST_ADDRESS, CHT_HOST_NAME, CHT_UNIX_SOCKET, pg_conn::client_encoding_initial, conn, CONNECTION_BAD, pg_conn::connhost, count_comma_separated_elems(), pg_conn::dbName, DEFAULT_PGSOCKET_DIR, DefaultChannelBinding, DefaultGSSMode, DefaultHost, DefaultSSLMode, pg_conn::errorMessage, free, pg_conn::gssencmode, pg_conn_host::host, pg_conn_host::hostaddr, i, is_unixsock_path(), libpq_append_conn_error(), malloc, MAXPGPATH, pg_conn::nconnhost, pg_conn::options_valid, parse_comma_separated_list(), pg_conn_host::password, passwordFromFile(), pg_encoding_to_char(), pg_fe_getauthname(), pg_get_encoding_from_locale(), pg_conn::pghost, pg_conn::pghostaddr, pg_conn::pgpass, PGPASSFILE, pg_conn::pgpassfile, pg_conn::pgport, pg_conn::pguser, pg_conn_host::port, pqGetHomeDirectory(), SERVER_TYPE_ANY, SERVER_TYPE_PREFER_STANDBY, SERVER_TYPE_PRIMARY, SERVER_TYPE_READ_ONLY, SERVER_TYPE_READ_WRITE, SERVER_TYPE_STANDBY, snprintf, pg_conn::ssl_max_protocol_version, pg_conn::ssl_min_protocol_version, pg_conn::sslmode, sslVerifyProtocolRange(), sslVerifyProtocolVersion(), pg_conn::status, pg_conn::target_server_type, pg_conn::target_session_attrs, pg_conn_host::type, and pg_conn::whichhost.

Referenced by PQconnectStart(), PQconnectStartParams(), and PQsetdbLogin().

conninfo_add_defaults()

static bool conninfo_add_defaults ( PQconninfoOption *  options, PQExpBuffer  errorMessage  )

static

Definition at line 5806 of file fe-connect.c.

{
    PQconninfoOption *option;
    char       *tmp;
 
    /*
     * If there's a service spec, use it to obtain any not-explicitly-given
     * parameters.  Ignore error if no error message buffer is passed because
     * there is no way to pass back the failure message.
     */
    if (parseServiceInfo(options, errorMessage) != 0 && errorMessage)
        return false;
 
    /*
     * Get the fallback resources for parameters not specified in the conninfo
     * string nor the service.
     */
    for (option = options; option->keyword != NULL; option++)
    {
        if (option->val != NULL)
            continue;           /* Value was in conninfo or service */
 
        /*
         * Try to get the environment variable fallback
         */
        if (option->envvar != NULL)
        {
            if ((tmp = getenv(option->envvar)) != NULL)
            {
                option->val = strdup(tmp);
                if (!option->val)
                {
                    if (errorMessage)
                        libpq_append_error(errorMessage, "out of memory");
                    return false;
                }
                continue;
            }
        }
 
        /*
         * Interpret the deprecated PGREQUIRESSL environment variable.  Per
         * tradition, translate values starting with "1" to sslmode=require,
         * and ignore other values.  Given both PGREQUIRESSL=1 and PGSSLMODE,
         * PGSSLMODE takes precedence; the opposite was true before v9.3.
         */
        if (strcmp(option->keyword, "sslmode") == 0)
        {
            const char *requiresslenv = getenv("PGREQUIRESSL");
 
            if (requiresslenv != NULL && requiresslenv[0] == '1')
            {
                option->val = strdup("require");
                if (!option->val)
                {
                    if (errorMessage)
                        libpq_append_error(errorMessage, "out of memory");
                    return false;
                }
                continue;
            }
        }
 
        /*
         * No environment variable specified or the variable isn't set - try
         * compiled-in default
         */
        if (option->compiled != NULL)
        {
            option->val = strdup(option->compiled);
            if (!option->val)
            {
                if (errorMessage)
                    libpq_append_error(errorMessage, "out of memory");
                return false;
            }
            continue;
        }
 
        /*
         * Special handling for "user" option.  Note that if pg_fe_getauthname
         * fails, we just leave the value as NULL; there's no need for this to
         * be an error condition if the caller provides a user name.  The only
         * reason we do this now at all is so that callers of PQconndefaults
         * will see a correct default (barring error, of course).
         */
        if (strcmp(option->keyword, "user") == 0)
        {
            option->val = pg_fe_getauthname(NULL);
            continue;
        }
    }
 
    return true;
}

References libpq_append_error(), parseServiceInfo(), pg_fe_getauthname(), and option::val.

Referenced by conninfo_array_parse(), conninfo_parse(), conninfo_uri_parse(), and PQconndefaults().

conninfo_array_parse()

static PQconninfoOption * conninfo_array_parse ( const char *const *  keywords, const char *const *  values, PQExpBuffer  errorMessage, bool  use_defaults, int  expand_dbname  )

static

Definition at line 5648 of file fe-connect.c.

{
    PQconninfoOption *options;
    PQconninfoOption *dbname_options = NULL;
    PQconninfoOption *option;
    int         i = 0;
 
    /*
     * If expand_dbname is non-zero, check keyword "dbname" to see if val is
     * actually a recognized connection string.
     */
    while (expand_dbname && keywords[i])
    {
        const char *pname = keywords[i];
        const char *pvalue = values[i];
 
        /* first find "dbname" if any */
        if (strcmp(pname, "dbname") == 0 && pvalue)
        {
            /*
             * If value is a connection string, parse it, but do not use
             * defaults here -- those get picked up later. We only want to
             * override for those parameters actually passed.
             */
            if (recognized_connection_string(pvalue))
            {
                dbname_options = parse_connection_string(pvalue, errorMessage, false);
                if (dbname_options == NULL)
                    return NULL;
            }
            break;
        }
        ++i;
    }
 
    /* Make a working copy of PQconninfoOptions */
    options = conninfo_init(errorMessage);
    if (options == NULL)
    {
        PQconninfoFree(dbname_options);
        return NULL;
    }
 
    /* Parse the keywords/values arrays */
    i = 0;
    while (keywords[i])
    {
        const char *pname = keywords[i];
        const char *pvalue = values[i];
 
        if (pvalue != NULL && pvalue[0] != '\0')
        {
            /* Search for the param record */
            for (option = options; option->keyword != NULL; option++)
            {
                if (strcmp(option->keyword, pname) == 0)
                    break;
            }
 
            /* Check for invalid connection option */
            if (option->keyword == NULL)
            {
                libpq_append_error(errorMessage, "invalid connection option \"%s\"", pname);
                PQconninfoFree(options);
                PQconninfoFree(dbname_options);
                return NULL;
            }
 
            /*
             * If we are on the first dbname parameter, and we have a parsed
             * connection string, copy those parameters across, overriding any
             * existing previous settings.
             */
            if (strcmp(pname, "dbname") == 0 && dbname_options)
            {
                PQconninfoOption *str_option;
 
                for (str_option = dbname_options; str_option->keyword != NULL; str_option++)
                {
                    if (str_option->val != NULL)
                    {
                        int         k;
 
                        for (k = 0; options[k].keyword; k++)
                        {
                            if (strcmp(options[k].keyword, str_option->keyword) == 0)
                            {
                                free(options[k].val);
                                options[k].val = strdup(str_option->val);
                                if (!options[k].val)
                                {
                                    libpq_append_error(errorMessage, "out of memory");
                                    PQconninfoFree(options);
                                    PQconninfoFree(dbname_options);
                                    return NULL;
                                }
                                break;
                            }
                        }
                    }
                }
 
                /*
                 * Forget the parsed connection string, so that any subsequent
                 * dbname parameters will not be expanded.
                 */
                PQconninfoFree(dbname_options);
                dbname_options = NULL;
            }
            else
            {
                /*
                 * Store the value, overriding previous settings
                 */
                free(option->val);
                option->val = strdup(pvalue);
                if (!option->val)
                {
                    libpq_append_error(errorMessage, "out of memory");
                    PQconninfoFree(options);
                    PQconninfoFree(dbname_options);
                    return NULL;
                }
            }
        }
        ++i;
    }
    PQconninfoFree(dbname_options);
 
    /*
     * Add in defaults if the caller wants that.
     */
    if (use_defaults)
    {
        if (!conninfo_add_defaults(options, errorMessage))
        {
            PQconninfoFree(options);
            return NULL;
        }
    }
 
    return options;
}

References conninfo_add_defaults(), conninfo_init(), free, i, _PQconninfoOption::keyword, libpq_append_error(), options, parse_connection_string(), PQconninfoFree(), recognized_connection_string(), option::val, val, _PQconninfoOption::val, and values.

Referenced by PQconnectStartParams().

conninfo_find()

static PQconninfoOption * conninfo_find ( PQconninfoOption *  connOptions, const char *  keyword  )

static

Definition at line 6514 of file fe-connect.c.

{
    PQconninfoOption *option;
 
    for (option = connOptions; option->keyword != NULL; option++)
    {
        if (strcmp(option->keyword, keyword) == 0)
            return option;
    }
 
    return NULL;
}

Referenced by conninfo_getval(), and conninfo_storeval().

conninfo_getval()

static const char * conninfo_getval ( PQconninfoOption *  connOptions, const char *  keyword  )

static

Definition at line 6424 of file fe-connect.c.

{
    PQconninfoOption *option;
 
    option = conninfo_find(connOptions, keyword);
 
    return option ? option->val : NULL;
}

References conninfo_find(), and option::val.

Referenced by fillPGconn(), and parseServiceInfo().

conninfo_init()

static PQconninfoOption * conninfo_init ( PQExpBuffer  errorMessage )

static

Definition at line 5379 of file fe-connect.c.

{
    PQconninfoOption *options;
    PQconninfoOption *opt_dest;
    const internalPQconninfoOption *cur_opt;
 
    /*
     * Get enough memory for all options in PQconninfoOptions, even if some
     * end up being filtered out.
     */
    options = (PQconninfoOption *) malloc(sizeof(PQconninfoOption) * sizeof(PQconninfoOptions) / sizeof(PQconninfoOptions[0]));
    if (options == NULL)
    {
        libpq_append_error(errorMessage, "out of memory");
        return NULL;
    }
    opt_dest = options;
 
    for (cur_opt = PQconninfoOptions; cur_opt->keyword; cur_opt++)
    {
        /* Only copy the public part of the struct, not the full internal */
        memcpy(opt_dest, cur_opt, sizeof(PQconninfoOption));
        opt_dest++;
    }
    MemSet(opt_dest, 0, sizeof(PQconninfoOption));
 
    return options;
}

References _internalPQconninfoOption::keyword, libpq_append_error(), malloc, MemSet, options, and PQconninfoOptions.

Referenced by conninfo_array_parse(), conninfo_parse(), conninfo_uri_parse(), PQconndefaults(), and PQconninfo().

conninfo_parse()

static PQconninfoOption * conninfo_parse ( const char *  conninfo, PQExpBuffer  errorMessage, bool  use_defaults  )

static

Definition at line 5472 of file fe-connect.c.

{
    char       *pname;
    char       *pval;
    char       *buf;
    char       *cp;
    char       *cp2;
    PQconninfoOption *options;
 
    /* Make a working copy of PQconninfoOptions */
    options = conninfo_init(errorMessage);
    if (options == NULL)
        return NULL;
 
    /* Need a modifiable copy of the input string */
    if ((buf = strdup(conninfo)) == NULL)
    {
        libpq_append_error(errorMessage, "out of memory");
        PQconninfoFree(options);
        return NULL;
    }
    cp = buf;
 
    while (*cp)
    {
        /* Skip blanks before the parameter name */
        if (isspace((unsigned char) *cp))
        {
            cp++;
            continue;
        }
 
        /* Get the parameter name */
        pname = cp;
        while (*cp)
        {
            if (*cp == '=')
                break;
            if (isspace((unsigned char) *cp))
            {
                *cp++ = '\0';
                while (*cp)
                {
                    if (!isspace((unsigned char) *cp))
                        break;
                    cp++;
                }
                break;
            }
            cp++;
        }
 
        /* Check that there is a following '=' */
        if (*cp != '=')
        {
            libpq_append_error(errorMessage,
                               "missing \"=\" after \"%s\" in connection info string",
                               pname);
            PQconninfoFree(options);
            free(buf);
            return NULL;
        }
        *cp++ = '\0';
 
        /* Skip blanks after the '=' */
        while (*cp)
        {
            if (!isspace((unsigned char) *cp))
                break;
            cp++;
        }
 
        /* Get the parameter value */
        pval = cp;
 
        if (*cp != '\'')
        {
            cp2 = pval;
            while (*cp)
            {
                if (isspace((unsigned char) *cp))
                {
                    *cp++ = '\0';
                    break;
                }
                if (*cp == '\\')
                {
                    cp++;
                    if (*cp != '\0')
                        *cp2++ = *cp++;
                }
                else
                    *cp2++ = *cp++;
            }
            *cp2 = '\0';
        }
        else
        {
            cp2 = pval;
            cp++;
            for (;;)
            {
                if (*cp == '\0')
                {
                    libpq_append_error(errorMessage, "unterminated quoted string in connection info string");
                    PQconninfoFree(options);
                    free(buf);
                    return NULL;
                }
                if (*cp == '\\')
                {
                    cp++;
                    if (*cp != '\0')
                        *cp2++ = *cp++;
                    continue;
                }
                if (*cp == '\'')
                {
                    *cp2 = '\0';
                    cp++;
                    break;
                }
                *cp2++ = *cp++;
            }
        }
 
        /*
         * Now that we have the name and the value, store the record.
         */
        if (!conninfo_storeval(options, pname, pval, errorMessage, false, false))
        {
            PQconninfoFree(options);
            free(buf);
            return NULL;
        }
    }
 
    /* Done with the modifiable input string */
    free(buf);
 
    /*
     * Add in defaults if the caller wants that.
     */
    if (use_defaults)
    {
        if (!conninfo_add_defaults(options, errorMessage))
        {
            PQconninfoFree(options);
            return NULL;
        }
    }
 
    return options;
}

References buf, conninfo_add_defaults(), conninfo_init(), conninfo_storeval(), free, libpq_append_error(), options, and PQconninfoFree().

Referenced by parse_connection_string().

conninfo_storeval()

static PQconninfoOption * conninfo_storeval ( PQconninfoOption *  connOptions, const char *  keyword, const char *  value, PQExpBuffer  errorMessage, bool  ignoreMissing, bool  uri_decode  )

static

Definition at line 6450 of file fe-connect.c.

{
    PQconninfoOption *option;
    char       *value_copy;
 
    /*
     * For backwards compatibility, requiressl=1 gets translated to
     * sslmode=require, and requiressl=0 gets translated to sslmode=prefer
     * (which is the default for sslmode).
     */
    if (strcmp(keyword, "requiressl") == 0)
    {
        keyword = "sslmode";
        if (value[0] == '1')
            value = "require";
        else
            value = "prefer";
    }
 
    option = conninfo_find(connOptions, keyword);
    if (option == NULL)
    {
        if (!ignoreMissing)
            libpq_append_error(errorMessage,
                               "invalid connection option \"%s\"",
                               keyword);
        return NULL;
    }
 
    if (uri_decode)
    {
        value_copy = conninfo_uri_decode(value, errorMessage);
        if (value_copy == NULL)
            /* conninfo_uri_decode already set an error message */
            return NULL;
    }
    else
    {
        value_copy = strdup(value);
        if (value_copy == NULL)
        {
            libpq_append_error(errorMessage, "out of memory");
            return NULL;
        }
    }
 
    free(option->val);
    option->val = value_copy;
 
    return option;
}

References conninfo_find(), conninfo_uri_decode(), free, libpq_append_error(), option::val, and value.

Referenced by conninfo_parse(), conninfo_uri_parse_options(), conninfo_uri_parse_params(), and PQconninfo().

conninfo_uri_decode()

static char * conninfo_uri_decode ( const char *  str, PQExpBuffer  errorMessage  )

static

Definition at line 6335 of file fe-connect.c.

{
    char       *buf;
    char       *p;
    const char *q = str;
 
    buf = malloc(strlen(str) + 1);
    if (buf == NULL)
    {
        libpq_append_error(errorMessage, "out of memory");
        return NULL;
    }
    p = buf;
 
    for (;;)
    {
        if (*q != '%')
        {
            /* copy and check for NUL terminator */
            if (!(*(p++) = *(q++)))
                break;
        }
        else
        {
            int         hi;
            int         lo;
            int         c;
 
            ++q;                /* skip the percent sign itself */
 
            /*
             * Possible EOL will be caught by the first call to
             * get_hexdigit(), so we never dereference an invalid q pointer.
             */
            if (!(get_hexdigit(*q++, &hi) && get_hexdigit(*q++, &lo)))
            {
                libpq_append_error(errorMessage,
                                   "invalid percent-encoded token: \"%s\"",
                                   str);
                free(buf);
                return NULL;
            }
 
            c = (hi << 4) | lo;
            if (c == 0)
            {
                libpq_append_error(errorMessage,
                                   "forbidden value %%00 in percent-encoded value: \"%s\"",
                                   str);
                free(buf);
                return NULL;
            }
            *(p++) = c;
        }
    }
 
    return buf;
}

References buf, free, get_hexdigit(), libpq_append_error(), malloc, and generate_unaccent_rules::str.

Referenced by conninfo_storeval(), and conninfo_uri_parse_params().

conninfo_uri_parse()

static PQconninfoOption * conninfo_uri_parse ( const char *  uri, PQExpBuffer  errorMessage, bool  use_defaults  )

static

Definition at line 5908 of file fe-connect.c.

{
    PQconninfoOption *options;
 
    /* Make a working copy of PQconninfoOptions */
    options = conninfo_init(errorMessage);
    if (options == NULL)
        return NULL;
 
    if (!conninfo_uri_parse_options(options, uri, errorMessage))
    {
        PQconninfoFree(options);
        return NULL;
    }
 
    /*
     * Add in defaults if the caller wants that.
     */
    if (use_defaults)
    {
        if (!conninfo_add_defaults(options, errorMessage))
        {
            PQconninfoFree(options);
            return NULL;
        }
    }
 
    return options;
}

References conninfo_add_defaults(), conninfo_init(), conninfo_uri_parse_options(), options, and PQconninfoFree().

Referenced by parse_connection_string().

conninfo_uri_parse_options()

static bool conninfo_uri_parse_options ( PQconninfoOption *  options, const char *  uri, PQExpBuffer  errorMessage  )

static

Definition at line 5961 of file fe-connect.c.

{
    int         prefix_len;
    char       *p;
    char       *buf = NULL;
    char       *start;
    char        prevchar = '\0';
    char       *user = NULL;
    char       *host = NULL;
    bool        retval = false;
    PQExpBufferData hostbuf;
    PQExpBufferData portbuf;
 
    initPQExpBuffer(&hostbuf);
    initPQExpBuffer(&portbuf);
    if (PQExpBufferDataBroken(hostbuf) || PQExpBufferDataBroken(portbuf))
    {
        libpq_append_error(errorMessage, "out of memory");
        goto cleanup;
    }
 
    /* need a modifiable copy of the input URI */
    buf = strdup(uri);
    if (buf == NULL)
    {
        libpq_append_error(errorMessage, "out of memory");
        goto cleanup;
    }
    start = buf;
 
    /* Skip the URI prefix */
    prefix_len = uri_prefix_length(uri);
    if (prefix_len == 0)
    {
        /* Should never happen */
        libpq_append_error(errorMessage,
                           "invalid URI propagated to internal parser routine: \"%s\"",
                           uri);
        goto cleanup;
    }
    start += prefix_len;
    p = start;
 
    /* Look ahead for possible user credentials designator */
    while (*p && *p != '@' && *p != '/')
        ++p;
    if (*p == '@')
    {
        /*
         * Found username/password designator, so URI should be of the form
         * "scheme://user[:password]@[netloc]".
         */
        user = start;
 
        p = user;
        while (*p != ':' && *p != '@')
            ++p;
 
        /* Save last char and cut off at end of user name */
        prevchar = *p;
        *p = '\0';
 
        if (*user &&
            !conninfo_storeval(options, "user", user,
                               errorMessage, false, true))
            goto cleanup;
 
        if (prevchar == ':')
        {
            const char *password = p + 1;
 
            while (*p != '@')
                ++p;
            *p = '\0';
 
            if (*password &&
                !conninfo_storeval(options, "password", password,
                                   errorMessage, false, true))
                goto cleanup;
        }
 
        /* Advance past end of parsed user name or password token */
        ++p;
    }
    else
    {
        /*
         * No username/password designator found.  Reset to start of URI.
         */
        p = start;
    }
 
    /*
     * There may be multiple netloc[:port] pairs, each separated from the next
     * by a comma.  When we initially enter this loop, "p" has been
     * incremented past optional URI credential information at this point and
     * now points at the "netloc" part of the URI.  On subsequent loop
     * iterations, "p" has been incremented past the comma separator and now
     * points at the start of the next "netloc".
     */
    for (;;)
    {
        /*
         * Look for IPv6 address.
         */
        if (*p == '[')
        {
            host = ++p;
            while (*p && *p != ']')
                ++p;
            if (!*p)
            {
                libpq_append_error(errorMessage,
                                   "end of string reached when looking for matching \"]\" in IPv6 host address in URI: \"%s\"",
                                   uri);
                goto cleanup;
            }
            if (p == host)
            {
                libpq_append_error(errorMessage,
                                   "IPv6 host address may not be empty in URI: \"%s\"",
                                   uri);
                goto cleanup;
            }
 
            /* Cut off the bracket and advance */
            *(p++) = '\0';
 
            /*
             * The address may be followed by a port specifier or a slash or a
             * query or a separator comma.
             */
            if (*p && *p != ':' && *p != '/' && *p != '?' && *p != ',')
            {
                libpq_append_error(errorMessage,
                                   "unexpected character \"%c\" at position %d in URI (expected \":\" or \"/\"): \"%s\"",
                                   *p, (int) (p - buf + 1), uri);
                goto cleanup;
            }
        }
        else
        {
            /* not an IPv6 address: DNS-named or IPv4 netloc */
            host = p;
 
            /*
             * Look for port specifier (colon) or end of host specifier
             * (slash) or query (question mark) or host separator (comma).
             */
            while (*p && *p != ':' && *p != '/' && *p != '?' && *p != ',')
                ++p;
        }
 
        /* Save the hostname terminator before we null it */
        prevchar = *p;
        *p = '\0';
 
        appendPQExpBufferStr(&hostbuf, host);
 
        if (prevchar == ':')
        {
            const char *port = ++p; /* advance past host terminator */
 
            while (*p && *p != '/' && *p != '?' && *p != ',')
                ++p;
 
            prevchar = *p;
            *p = '\0';
 
            appendPQExpBufferStr(&portbuf, port);
        }
 
        if (prevchar != ',')
            break;
        ++p;                    /* advance past comma separator */
        appendPQExpBufferChar(&hostbuf, ',');
        appendPQExpBufferChar(&portbuf, ',');
    }
 
    /* Save final values for host and port. */
    if (PQExpBufferDataBroken(hostbuf) || PQExpBufferDataBroken(portbuf))
        goto cleanup;
    if (hostbuf.data[0] &&
        !conninfo_storeval(options, "host", hostbuf.data,
                           errorMessage, false, true))
        goto cleanup;
    if (portbuf.data[0] &&
        !conninfo_storeval(options, "port", portbuf.data,
                           errorMessage, false, true))
        goto cleanup;
 
    if (prevchar && prevchar != '?')
    {
        const char *dbname = ++p;   /* advance past host terminator */
 
        /* Look for query parameters */
        while (*p && *p != '?')
            ++p;
 
        prevchar = *p;
        *p = '\0';
 
        /*
         * Avoid setting dbname to an empty string, as it forces the default
         * value (username) and ignores $PGDATABASE, as opposed to not setting
         * it at all.
         */
        if (*dbname &&
            !conninfo_storeval(options, "dbname", dbname,
                               errorMessage, false, true))
            goto cleanup;
    }
 
    if (prevchar)
    {
        ++p;                    /* advance past terminator */
 
        if (!conninfo_uri_parse_params(p, options, errorMessage))
            goto cleanup;
    }
 
    /* everything parsed okay */
    retval = true;
 
cleanup:
    termPQExpBuffer(&hostbuf);
    termPQExpBuffer(&portbuf);
    free(buf);
    return retval;
}

References appendPQExpBufferChar(), appendPQExpBufferStr(), buf, cleanup(), conninfo_storeval(), conninfo_uri_parse_params(), PQExpBufferData::data, dbname, free, initPQExpBuffer(), libpq_append_error(), password, port, PQExpBufferDataBroken, termPQExpBuffer(), uri_prefix_length(), and user.

Referenced by conninfo_uri_parse().

conninfo_uri_parse_params()

static bool conninfo_uri_parse_params ( char *  params, PQconninfoOption *  connOptions, PQExpBuffer  errorMessage  )

static

Definition at line 6202 of file fe-connect.c.

{
    while (*params)
    {
        char       *keyword = params;
        char       *value = NULL;
        char       *p = params;
        bool        malloced = false;
        int         oldmsglen;
 
        /*
         * Scan the params string for '=' and '&', marking the end of keyword
         * and value respectively.
         */
        for (;;)
        {
            if (*p == '=')
            {
                /* Was there '=' already? */
                if (value != NULL)
                {
                    libpq_append_error(errorMessage,
                                       "extra key/value separator \"=\" in URI query parameter: \"%s\"",
                                       keyword);
                    return false;
                }
                /* Cut off keyword, advance to value */
                *p++ = '\0';
                value = p;
            }
            else if (*p == '&' || *p == '\0')
            {
                /*
                 * If not at the end, cut off value and advance; leave p
                 * pointing to start of the next parameter, if any.
                 */
                if (*p != '\0')
                    *p++ = '\0';
                /* Was there '=' at all? */
                if (value == NULL)
                {
                    libpq_append_error(errorMessage,
                                       "missing key/value separator \"=\" in URI query parameter: \"%s\"",
                                       keyword);
                    return false;
                }
                /* Got keyword and value, go process them. */
                break;
            }
            else
                ++p;            /* Advance over all other bytes. */
        }
 
        keyword = conninfo_uri_decode(keyword, errorMessage);
        if (keyword == NULL)
        {
            /* conninfo_uri_decode already set an error message */
            return false;
        }
        value = conninfo_uri_decode(value, errorMessage);
        if (value == NULL)
        {
            /* conninfo_uri_decode already set an error message */
            free(keyword);
            return false;
        }
        malloced = true;
 
        /*
         * Special keyword handling for improved JDBC compatibility.
         */
        if (strcmp(keyword, "ssl") == 0 &&
            strcmp(value, "true") == 0)
        {
            free(keyword);
            free(value);
            malloced = false;
 
            keyword = "sslmode";
            value = "require";
        }
 
        /*
         * Store the value if the corresponding option exists; ignore
         * otherwise.  At this point both keyword and value are not
         * URI-encoded.
         */
        oldmsglen = errorMessage->len;
        if (!conninfo_storeval(connOptions, keyword, value,
                               errorMessage, true, false))
        {
            /* Insert generic message if conninfo_storeval didn't give one. */
            if (errorMessage->len == oldmsglen)
                libpq_append_error(errorMessage,
                                   "invalid URI query parameter: \"%s\"",
                                   keyword);
            /* And fail. */
            if (malloced)
            {
                free(keyword);
                free(value);
            }
            return false;
        }
 
        if (malloced)
        {
            free(keyword);
            free(value);
        }
 
        /* Proceed to next key=value pair, if any */
        params = p;
    }
 
    return true;
}

References conninfo_storeval(), conninfo_uri_decode(), free, PQExpBufferData::len, libpq_append_error(), and value.

Referenced by conninfo_uri_parse_options().

count_comma_separated_elems()

static int count_comma_separated_elems ( const char *  input )

static

Definition at line 958 of file fe-connect.c.

{
    int         n;
 
    n = 1;
    for (; *input != '\0'; input++)
    {
        if (*input == ',')
            n++;
    }
 
    return n;
}

Referenced by connectOptions2().

default_threadlock()

static void default_threadlock ( int  acquire )

static

Definition at line 7272 of file fe-connect.c.

{
#ifdef ENABLE_THREAD_SAFETY
#ifndef WIN32
    static pthread_mutex_t singlethread_lock = PTHREAD_MUTEX_INITIALIZER;
#else
    static pthread_mutex_t singlethread_lock = NULL;
    static long mutex_initlock = 0;
 
    if (singlethread_lock == NULL)
    {
        while (InterlockedExchange(&mutex_initlock, 1) == 1)
             /* loop, another thread own the lock */ ;
        if (singlethread_lock == NULL)
        {
            if (pthread_mutex_init(&singlethread_lock, NULL))
                Assert(false);
        }
        InterlockedExchange(&mutex_initlock, 0);
    }
#endif
    if (acquire)
    {
        if (pthread_mutex_lock(&singlethread_lock))
            Assert(false);
    }
    else
    {
        if (pthread_mutex_unlock(&singlethread_lock))
            Assert(false);
    }
#endif
}

References Assert(), pthread_mutex_init(), pthread_mutex_lock(), and pthread_mutex_unlock().

Referenced by PQregisterThreadLock().

defaultNoticeProcessor()

static void defaultNoticeProcessor ( void *  arg, const char *  message  )

static

Definition at line 6949 of file fe-connect.c.

{
    (void) arg;                 /* not used */
    /* Note: we expect the supplied string to end with a newline already. */
    fprintf(stderr, "%s", message);
}

References arg, and fprintf.

Referenced by makeEmptyPGconn().

defaultNoticeReceiver()

static void defaultNoticeReceiver ( void *  arg, const PGresult *  res  )

static

Definition at line 6934 of file fe-connect.c.

{
    (void) arg;                 /* not used */
    if (res->noticeHooks.noticeProc != NULL)
        res->noticeHooks.noticeProc(res->noticeHooks.noticeProcArg,
                                    PQresultErrorMessage(res));
}

References arg, pg_result::noticeHooks, PGNoticeHooks::noticeProc, PGNoticeHooks::noticeProcArg, PQresultErrorMessage(), and res.

Referenced by makeEmptyPGconn().

emitHostIdentityInfo()

static void emitHostIdentityInfo ( PGconn *  conn, const char *  host_addr  )

static

Definition at line 1659 of file fe-connect.c.

{
    if (conn->raddr.addr.ss_family == AF_UNIX)
    {
        char        service[NI_MAXHOST];
 
        pg_getnameinfo_all(&conn->raddr.addr, conn->raddr.salen,
                           NULL, 0,
                           service, sizeof(service),
                           NI_NUMERICSERV);
        appendPQExpBuffer(&conn->errorMessage,
                          libpq_gettext("connection to server on socket \"%s\" failed: "),
                          service);
    }
    else
    {
        const char *displayed_host;
        const char *displayed_port;
 
        /* To which host and port were we actually connecting? */
        if (conn->connhost[conn->whichhost].type == CHT_HOST_ADDRESS)
            displayed_host = conn->connhost[conn->whichhost].hostaddr;
        else
            displayed_host = conn->connhost[conn->whichhost].host;
        displayed_port = conn->connhost[conn->whichhost].port;
        if (displayed_port == NULL || displayed_port[0] == '\0')
            displayed_port = DEF_PGPORT_STR;
 
        /*
         * If the user did not supply an IP address using 'hostaddr', and
         * 'host' was missing or does not match our lookup, display the
         * looked-up IP address.
         */
        if (conn->connhost[conn->whichhost].type != CHT_HOST_ADDRESS &&
            host_addr[0] &&
            strcmp(displayed_host, host_addr) != 0)
            appendPQExpBuffer(&conn->errorMessage,
                              libpq_gettext("connection to server at \"%s\" (%s), port %s failed: "),
                              displayed_host, host_addr,
                              displayed_port);
        else
            appendPQExpBuffer(&conn->errorMessage,
                              libpq_gettext("connection to server at \"%s\", port %s failed: "),
                              displayed_host,
                              displayed_port);
    }
}

References SockAddr::addr, appendPQExpBuffer(), CHT_HOST_ADDRESS, conn, pg_conn::connhost, pg_conn::errorMessage, pg_conn_host::host, pg_conn_host::hostaddr, libpq_gettext, pg_getnameinfo_all(), pg_conn_host::port, pg_conn::raddr, SockAddr::salen, pg_conn_host::type, and pg_conn::whichhost.

Referenced by PQconnectPoll().

fillPGconn()

static bool fillPGconn ( PGconn *  conn, PQconninfoOption *  connOptions  )

static

Definition at line 881 of file fe-connect.c.

{
    const internalPQconninfoOption *option;
 
    for (option = PQconninfoOptions; option->keyword; option++)
    {
        if (option->connofs >= 0)
        {
            const char *tmp = conninfo_getval(connOptions, option->keyword);
 
            if (tmp)
            {
                char      **connmember = (char **) ((char *) conn + option->connofs);
 
                free(*connmember);
                *connmember = strdup(tmp);
                if (*connmember == NULL)
                {
                    libpq_append_conn_error(conn, "out of memory");
                    return false;
                }
            }
        }
    }
 
    return true;
}

References conn, conninfo_getval(), free, libpq_append_conn_error(), and PQconninfoOptions.

Referenced by connectOptions1(), and PQconnectStartParams().

freePGconn()

static void freePGconn ( PGconn *  conn )

static

Definition at line 3961 of file fe-connect.c.

{
    /* let any event procs clean up their state data */
    for (int i = 0; i < conn->nEvents; i++)
    {
        PGEventConnDestroy evt;
 
        evt.conn = conn;
        (void) conn->events[i].proc(PGEVT_CONNDESTROY, &evt,
                                    conn->events[i].passThrough);
        free(conn->events[i].name);
    }
 
    /* clean up pg_conn_host structures */
    for (int i = 0; i < conn->nconnhost; ++i)
    {
        free(conn->connhost[i].host);
        free(conn->connhost[i].hostaddr);
        free(conn->connhost[i].port);
        if (conn->connhost[i].password != NULL)
        {
            explicit_bzero(conn->connhost[i].password, strlen(conn->connhost[i].password));
            free(conn->connhost[i].password);
        }
    }
    free(conn->connhost);
 
    free(conn->client_encoding_initial);
    free(conn->events);
    free(conn->pghost);
    free(conn->pghostaddr);
    free(conn->pgport);
    free(conn->connect_timeout);
    free(conn->pgtcp_user_timeout);
    free(conn->pgoptions);
    free(conn->appname);
    free(conn->fbappname);
    free(conn->dbName);
    free(conn->replication);
    free(conn->pguser);
    if (conn->pgpass)
    {
        explicit_bzero(conn->pgpass, strlen(conn->pgpass));
        free(conn->pgpass);
    }
    free(conn->pgpassfile);
    free(conn->channel_binding);
    free(conn->keepalives);
    free(conn->keepalives_idle);
    free(conn->keepalives_interval);
    free(conn->keepalives_count);
    free(conn->sslmode);
    free(conn->sslcert);
    free(conn->sslkey);
    if (conn->sslpassword)
    {
        explicit_bzero(conn->sslpassword, strlen(conn->sslpassword));
        free(conn->sslpassword);
    }
    free(conn->sslrootcert);
    free(conn->sslcrl);
    free(conn->sslcrldir);
    free(conn->sslcompression);
    free(conn->sslsni);
    free(conn->requirepeer);
    free(conn->ssl_min_protocol_version);
    free(conn->ssl_max_protocol_version);
    free(conn->gssencmode);
    free(conn->krbsrvname);
    free(conn->gsslib);
    free(conn->connip);
    /* Note that conn->Pfdebug is not ours to close or free */
    free(conn->write_err_msg);
    free(conn->inBuffer);
    free(conn->outBuffer);
    free(conn->rowBuf);
    free(conn->target_session_attrs);
    termPQExpBuffer(&conn->errorMessage);
    termPQExpBuffer(&conn->workBuffer);
 
    free(conn);
}

References pg_conn::appname, pg_conn::channel_binding, pg_conn::client_encoding_initial, conn, PGEventConnDestroy::conn, pg_conn::connect_timeout, pg_conn::connhost, pg_conn::connip, pg_conn::dbName, pg_conn::errorMessage, pg_conn::events, explicit_bzero(), pg_conn::fbappname, free, pg_conn::gssencmode, pg_conn::gsslib, pg_conn_host::host, pg_conn_host::hostaddr, i, pg_conn::inBuffer, pg_conn::keepalives, pg_conn::keepalives_count, pg_conn::keepalives_idle, pg_conn::keepalives_interval, pg_conn::krbsrvname, PGEvent::name, pg_conn::nconnhost, pg_conn::nEvents, pg_conn::outBuffer, PGEvent::passThrough, pg_conn_host::password, PGEVT_CONNDESTROY, pg_conn::pghost, pg_conn::pghostaddr, pg_conn::pgoptions, pg_conn::pgpass, pg_conn::pgpassfile, pg_conn::pgport, pg_conn::pgtcp_user_timeout, pg_conn::pguser, pg_conn_host::port, PGEvent::proc, pg_conn::replication, pg_conn::requirepeer, pg_conn::rowBuf, pg_conn::ssl_max_protocol_version, pg_conn::ssl_min_protocol_version, pg_conn::sslcert, pg_conn::sslcompression, pg_conn::sslcrl, pg_conn::sslcrldir, pg_conn::sslkey, pg_conn::sslmode, pg_conn::sslpassword, pg_conn::sslrootcert, pg_conn::sslsni, pg_conn::target_session_attrs, termPQExpBuffer(), pg_conn::workBuffer, and pg_conn::write_err_msg.

Referenced by makeEmptyPGconn(), and PQfinish().

get_hexdigit()

static bool get_hexdigit ( char  digit, int *  value  )

static

Definition at line 6403 of file fe-connect.c.

{
    if ('0' <= digit && digit <= '9')
        *value = digit - '0';
    else if ('A' <= digit && digit <= 'F')
        *value = digit - 'A' + 10;
    else if ('a' <= digit && digit <= 'f')
        *value = digit - 'a' + 10;
    else
        return false;
 
    return true;
}

References value.

Referenced by conninfo_uri_decode().

getHostaddr()

static void getHostaddr ( PGconn *  conn, char *  host_addr, int  host_addr_len  )

static

Definition at line 1626 of file fe-connect.c.

{
    struct sockaddr_storage *addr = &conn->raddr.addr;
 
    if (addr->ss_family == AF_INET)
    {
        if (pg_inet_net_ntop(AF_INET,
                             &((struct sockaddr_in *) addr)->sin_addr.s_addr,
                             32,
                             host_addr, host_addr_len) == NULL)
            host_addr[0] = '\0';
    }
    else if (addr->ss_family == AF_INET6)
    {
        if (pg_inet_net_ntop(AF_INET6,
                             &((struct sockaddr_in6 *) addr)->sin6_addr.s6_addr,
                             128,
                             host_addr, host_addr_len) == NULL)
            host_addr[0] = '\0';
    }
    else
        host_addr[0] = '\0';
}

References SockAddr::addr, conn, pg_inet_net_ntop(), and pg_conn::raddr.

Referenced by PQconnectPoll().

internal_ping()

static PGPing internal_ping ( PGconn *  conn )

static

Definition at line 3799 of file fe-connect.c.

{
    /* Say "no attempt" if we never got to PQconnectPoll */
    if (!conn || !conn->options_valid)
        return PQPING_NO_ATTEMPT;
 
    /* Attempt to complete the connection */
    if (conn->status != CONNECTION_BAD)
        (void) connectDBComplete(conn);
 
    /* Definitely OK if we succeeded */
    if (conn->status != CONNECTION_BAD)
        return PQPING_OK;
 
    /*
     * Here begins the interesting part of "ping": determine the cause of the
     * failure in sufficient detail to decide what to return.  We do not want
     * to report that the server is not up just because we didn't have a valid
     * password, for example.  In fact, any sort of authentication request
     * implies the server is up.  (We need this check since the libpq side of
     * things might have pulled the plug on the connection before getting an
     * error as such from the postmaster.)
     */
    if (conn->auth_req_received)
        return PQPING_OK;
 
    /*
     * If we failed to get any ERROR response from the postmaster, report
     * PQPING_NO_RESPONSE.  This result could be somewhat misleading for a
     * pre-7.4 server, since it won't send back a SQLSTATE, but those are long
     * out of support.  Another corner case where the server could return a
     * failure without a SQLSTATE is fork failure, but PQPING_NO_RESPONSE
     * isn't totally unreasonable for that anyway.  We expect that every other
     * failure case in a modern server will produce a report with a SQLSTATE.
     *
     * NOTE: whenever we get around to making libpq generate SQLSTATEs for
     * client-side errors, we should either not store those into
     * last_sqlstate, or add an extra flag so we can tell client-side errors
     * apart from server-side ones.
     */
    if (strlen(conn->last_sqlstate) != 5)
        return PQPING_NO_RESPONSE;
 
    /*
     * Report PQPING_REJECT if server says it's not accepting connections.
     */
    if (strcmp(conn->last_sqlstate, ERRCODE_CANNOT_CONNECT_NOW) == 0)
        return PQPING_REJECT;
 
    /*
     * Any other SQLSTATE can be taken to indicate that the server is up.
     * Presumably it didn't like our username, password, or database name; or
     * perhaps it had some transient failure, but that should not be taken as
     * meaning "it's down".
     */
    return PQPING_OK;
}

References pg_conn::auth_req_received, conn, connectDBComplete(), CONNECTION_BAD, ERRCODE_CANNOT_CONNECT_NOW, pg_conn::last_sqlstate, pg_conn::options_valid, PQPING_NO_ATTEMPT, PQPING_NO_RESPONSE, PQPING_OK, PQPING_REJECT, and pg_conn::status.

Referenced by PQping(), and PQpingParams().

makeEmptyPGconn()

static PGconn * makeEmptyPGconn ( void  )

static

Definition at line 3863 of file fe-connect.c.

{
    PGconn     *conn;
 
#ifdef WIN32
 
    /*
     * Make sure socket support is up and running in this process.
     *
     * Note: the Windows documentation says that we should eventually do a
     * matching WSACleanup() call, but experience suggests that that is at
     * least as likely to cause problems as fix them.  So we don't.
     */
    static bool wsastartup_done = false;
 
    if (!wsastartup_done)
    {
        WSADATA     wsaData;
 
        if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
            return NULL;
        wsastartup_done = true;
    }
 
    /* Forget any earlier error */
    WSASetLastError(0);
#endif                          /* WIN32 */
 
    conn = (PGconn *) malloc(sizeof(PGconn));
    if (conn == NULL)
        return conn;
 
    /* Zero all pointers and booleans */
    MemSet(conn, 0, sizeof(PGconn));
 
    /* install default notice hooks */
    conn->noticeHooks.noticeRec = defaultNoticeReceiver;
    conn->noticeHooks.noticeProc = defaultNoticeProcessor;
 
    conn->status = CONNECTION_BAD;
    conn->asyncStatus = PGASYNC_IDLE;
    conn->pipelineStatus = PQ_PIPELINE_OFF;
    conn->xactStatus = PQTRANS_IDLE;
    conn->options_valid = false;
    conn->nonblocking = false;
    conn->client_encoding = PG_SQL_ASCII;
    conn->std_strings = false;  /* unless server says differently */
    conn->default_transaction_read_only = PG_BOOL_UNKNOWN;
    conn->in_hot_standby = PG_BOOL_UNKNOWN;
    conn->verbosity = PQERRORS_DEFAULT;
    conn->show_context = PQSHOW_CONTEXT_ERRORS;
    conn->sock = PGINVALID_SOCKET;
    conn->Pfdebug = NULL;
 
    /*
     * We try to send at least 8K at a time, which is the usual size of pipe
     * buffers on Unix systems.  That way, when we are sending a large amount
     * of data, we avoid incurring extra kernel context swaps for partial
     * bufferloads.  The output buffer is initially made 16K in size, and we
     * try to dump it after accumulating 8K.
     *
     * With the same goal of minimizing context swaps, the input buffer will
     * be enlarged anytime it has less than 8K free, so we initially allocate
     * twice that.
     */
    conn->inBufSize = 16 * 1024;
    conn->inBuffer = (char *) malloc(conn->inBufSize);
    conn->outBufSize = 16 * 1024;
    conn->outBuffer = (char *) malloc(conn->outBufSize);
    conn->rowBufLen = 32;
    conn->rowBuf = (PGdataValue *) malloc(conn->rowBufLen * sizeof(PGdataValue));
    initPQExpBuffer(&conn->errorMessage);
    initPQExpBuffer(&conn->workBuffer);
 
    if (conn->inBuffer == NULL ||
        conn->outBuffer == NULL ||
        conn->rowBuf == NULL ||
        PQExpBufferBroken(&conn->errorMessage) ||
        PQExpBufferBroken(&conn->workBuffer))
    {
        /* out of memory already :-( */
        freePGconn(conn);
        conn = NULL;
    }
 
    return conn;
}

References pg_conn::asyncStatus, pg_conn::client_encoding, conn, CONNECTION_BAD, pg_conn::default_transaction_read_only, defaultNoticeProcessor(), defaultNoticeReceiver(), pg_conn::errorMessage, freePGconn(), pg_conn::in_hot_standby, pg_conn::inBuffer, pg_conn::inBufSize, initPQExpBuffer(), malloc, MemSet, pg_conn::nonblocking, pg_conn::noticeHooks, PGNoticeHooks::noticeProc, PGNoticeHooks::noticeRec, pg_conn::options_valid, pg_conn::outBuffer, pg_conn::outBufSize, pg_conn::Pfdebug, PG_BOOL_UNKNOWN, PG_SQL_ASCII, PGASYNC_IDLE, PGINVALID_SOCKET, pg_conn::pipelineStatus, PQ_PIPELINE_OFF, PQERRORS_DEFAULT, PQExpBufferBroken, PQSHOW_CONTEXT_ERRORS, PQTRANS_IDLE, pg_conn::rowBuf, pg_conn::rowBufLen, pg_conn::show_context, pg_conn::sock, pg_conn::status, pg_conn::std_strings, pg_conn::verbosity, pg_conn::workBuffer, and pg_conn::xactStatus.

Referenced by PQconnectStart(), PQconnectStartParams(), and PQsetdbLogin().

optional_setsockopt()

static bool optional_setsockopt ( int  fd, int  protoid, int  optid, int  value  )

static

Definition at line 4317 of file fe-connect.c.

{
    if (value < 0)
        return true;
    if (setsockopt(fd, protoid, optid, (char *) &value, sizeof(value)) < 0)
        return false;
    return true;
}

References fd(), and value.

Referenced by PQcancel().

parse_comma_separated_list()

static char* parse_comma_separated_list ( char **  startptr, bool *  more  )

static

Definition at line 982 of file fe-connect.c.

{
    char       *p;
    char       *s = *startptr;
    char       *e;
    int         len;
 
    /*
     * Search for the end of the current element; a comma or end-of-string
     * acts as a terminator.
     */
    e = s;
    while (*e != '\0' && *e != ',')
        ++e;
    *more = (*e == ',');
 
    len = e - s;
    p = (char *) malloc(sizeof(char) * (len + 1));
    if (p)
    {
        memcpy(p, s, len);
        p[len] = '\0';
    }
    *startptr = e + 1;
 
    return p;
}

References len, and malloc.

Referenced by connectOptions2().

parse_connection_string()

static PQconninfoOption * parse_connection_string ( const char *  connstr, PQExpBuffer  errorMessage, bool  use_defaults  )

static

Definition at line 5418 of file fe-connect.c.

{
    /* Parse as URI if connection string matches URI prefix */
    if (uri_prefix_length(connstr) != 0)
        return conninfo_uri_parse(connstr, errorMessage, use_defaults);
 
    /* Parse as default otherwise */
    return conninfo_parse(connstr, errorMessage, use_defaults);
}

References conninfo_parse(), conninfo_uri_parse(), connstr, and uri_prefix_length().

Referenced by connectOptions1(), conninfo_array_parse(), and PQconninfoParse().

parse_int_param()

static bool parse_int_param ( const char *  value, int *  result, PGconn *  conn, const char *  context  )

static

Definition at line 1754 of file fe-connect.c.

{
    char       *end;
    long        numval;
 
    Assert(value != NULL);
 
    *result = 0;
 
    /* strtol(3) skips leading whitespaces */
    errno = 0;
    numval = strtol(value, &end, 10);
 
    /*
     * If no progress was done during the parsing or an error happened, fail.
     * This tests properly for overflows of the result.
     */
    if (value == end || errno != 0 || numval != (int) numval)
        goto error;
 
    /*
     * Skip any trailing whitespace; if anything but whitespace remains before
     * the terminating character, fail
     */
    while (*end != '\0' && isspace((unsigned char) *end))
        end++;
 
    if (*end != '\0')
        goto error;
 
    *result = numval;
    return true;
 
error:
    libpq_append_conn_error(conn, "invalid integer value \"%s\" for connection option \"%s\"",
                       value, context);
    return false;
}

References Assert(), conn, error(), libpq_append_conn_error(), and value.

Referenced by connectDBComplete(), PQconnectPoll(), PQgetCancel(), setKeepalivesCount(), setKeepalivesIdle(), setKeepalivesInterval(), and setTCPUserTimeout().

parseServiceFile()

static int parseServiceFile ( const char *  serviceFile, const char *  service, PQconninfoOption *  options, PQExpBuffer  errorMessage, bool *  group_found  )

static

Definition at line 5179 of file fe-connect.c.

{
    int         result = 0,
                linenr = 0,
                i;
    FILE       *f;
    char       *line;
    char        buf[1024];
 
    *group_found = false;
 
    f = fopen(serviceFile, "r");
    if (f == NULL)
    {
        libpq_append_error(errorMessage, "service file \"%s\" not found", serviceFile);
        return 1;
    }
 
    while ((line = fgets(buf, sizeof(buf), f)) != NULL)
    {
        int         len;
 
        linenr++;
 
        if (strlen(line) >= sizeof(buf) - 1)
        {
            libpq_append_error(errorMessage,
                               "line %d too long in service file \"%s\"",
                               linenr,
                               serviceFile);
            result = 2;
            goto exit;
        }
 
        /* ignore whitespace at end of line, especially the newline */
        len = strlen(line);
        while (len > 0 && isspace((unsigned char) line[len - 1]))
            line[--len] = '\0';
 
        /* ignore leading whitespace too */
        while (*line && isspace((unsigned char) line[0]))
            line++;
 
        /* ignore comments and empty lines */
        if (line[0] == '\0' || line[0] == '#')
            continue;
 
        /* Check for right groupname */
        if (line[0] == '[')
        {
            if (*group_found)
            {
                /* end of desired group reached; return success */
                goto exit;
            }
 
            if (strncmp(line + 1, service, strlen(service)) == 0 &&
                line[strlen(service) + 1] == ']')
                *group_found = true;
            else
                *group_found = false;
        }
        else
        {
            if (*group_found)
            {
                /*
                 * Finally, we are in the right group and can parse the line
                 */
                char       *key,
                           *val;
                bool        found_keyword;
 
#ifdef USE_LDAP
                if (strncmp(line, "ldap", 4) == 0)
                {
                    int         rc = ldapServiceLookup(line, options, errorMessage);
 
                    /* if rc = 2, go on reading for fallback */
                    switch (rc)
                    {
                        case 0:
                            goto exit;
                        case 1:
                        case 3:
                            result = 3;
                            goto exit;
                        case 2:
                            continue;
                    }
                }
#endif
 
                key = line;
                val = strchr(line, '=');
                if (val == NULL)
                {
                    libpq_append_error(errorMessage,
                                       "syntax error in service file \"%s\", line %d",
                                       serviceFile,
                                       linenr);
                    result = 3;
                    goto exit;
                }
                *val++ = '\0';
 
                if (strcmp(key, "service") == 0)
                {
                    libpq_append_error(errorMessage,
                                       "nested service specifications not supported in service file \"%s\", line %d",
                                       serviceFile,
                                       linenr);
                    result = 3;
                    goto exit;
                }
 
                /*
                 * Set the parameter --- but don't override any previous
                 * explicit setting.
                 */
                found_keyword = false;
                for (i = 0; options[i].keyword; i++)
                {
                    if (strcmp(options[i].keyword, key) == 0)
                    {
                        if (options[i].val == NULL)
                            options[i].val = strdup(val);
                        if (!options[i].val)
                        {
                            libpq_append_error(errorMessage, "out of memory");
                            result = 3;
                            goto exit;
                        }
                        found_keyword = true;
                        break;
                    }
                }
 
                if (!found_keyword)
                {
                    libpq_append_error(errorMessage,
                                       "syntax error in service file \"%s\", line %d",
                                       serviceFile,
                                       linenr);
                    result = 3;
                    goto exit;
                }
            }
        }
    }
 
exit:
    fclose(f);
 
    return result;
}

References buf, exit(), i, sort-test::key, len, libpq_append_error(), and val.

Referenced by parseServiceInfo().

parseServiceInfo()

static int parseServiceInfo ( PQconninfoOption *  options, PQExpBuffer  errorMessage  )

static

Definition at line 5111 of file fe-connect.c.

{
    const char *service = conninfo_getval(options, "service");
    char        serviceFile[MAXPGPATH];
    char       *env;
    bool        group_found = false;
    int         status;
    struct stat stat_buf;
 
    /*
     * We have to special-case the environment variable PGSERVICE here, since
     * this is and should be called before inserting environment defaults for
     * other connection options.
     */
    if (service == NULL)
        service = getenv("PGSERVICE");
 
    /* If no service name given, nothing to do */
    if (service == NULL)
        return 0;
 
    /*
     * Try PGSERVICEFILE if specified, else try ~/.pg_service.conf (if that
     * exists).
     */
    if ((env = getenv("PGSERVICEFILE")) != NULL)
        strlcpy(serviceFile, env, sizeof(serviceFile));
    else
    {
        char        homedir[MAXPGPATH];
 
        if (!pqGetHomeDirectory(homedir, sizeof(homedir)))
            goto next_file;
        snprintf(serviceFile, MAXPGPATH, "%s/%s", homedir, ".pg_service.conf");
        if (stat(serviceFile, &stat_buf) != 0)
            goto next_file;
    }
 
    status = parseServiceFile(serviceFile, service, options, errorMessage, &group_found);
    if (group_found || status != 0)
        return status;
 
next_file:
 
    /*
     * This could be used by any application so we can't use the binary
     * location to find our config files.
     */
    snprintf(serviceFile, MAXPGPATH, "%s/pg_service.conf",
             getenv("PGSYSCONFDIR") ? getenv("PGSYSCONFDIR") : SYSCONFDIR);
    if (stat(serviceFile, &stat_buf) != 0)
        goto last_file;
 
    status = parseServiceFile(serviceFile, service, options, errorMessage, &group_found);
    if (status != 0)
        return status;
 
last_file:
    if (!group_found)
    {
        libpq_append_error(errorMessage, "definition of service \"%s\" not found", service);
        return 3;
    }
 
    return 0;
}

References conninfo_getval(), libpq_append_error(), MAXPGPATH, parseServiceFile(), pqGetHomeDirectory(), snprintf, stat, status(), and strlcpy().

Referenced by conninfo_add_defaults().

passwordFromFile()

static char * passwordFromFile ( const char *  hostname, const char *  port, const char *  dbname, const char *  username, const char *  pgpassfile  )

static

Definition at line 6998 of file fe-connect.c.

{
    FILE       *fp;
    struct stat stat_buf;
    PQExpBufferData buf;
 
    if (dbname == NULL || dbname[0] == '\0')
        return NULL;
 
    if (username == NULL || username[0] == '\0')
        return NULL;
 
    /* 'localhost' matches pghost of '' or the default socket directory */
    if (hostname == NULL || hostname[0] == '\0')
        hostname = DefaultHost;
    else if (is_unixsock_path(hostname))
 
        /*
         * We should probably use canonicalize_path(), but then we have to
         * bring path.c into libpq, and it doesn't seem worth it.
         */
        if (strcmp(hostname, DEFAULT_PGSOCKET_DIR) == 0)
            hostname = DefaultHost;
 
    if (port == NULL || port[0] == '\0')
        port = DEF_PGPORT_STR;
 
    /* If password file cannot be opened, ignore it. */
    if (stat(pgpassfile, &stat_buf) != 0)
        return NULL;
 
#ifndef WIN32
    if (!S_ISREG(stat_buf.st_mode))
    {
        fprintf(stderr,
                libpq_gettext("WARNING: password file \"%s\" is not a plain file\n"),
                pgpassfile);
        return NULL;
    }
 
    /* If password file is insecure, alert the user and ignore it. */
    if (stat_buf.st_mode & (S_IRWXG | S_IRWXO))
    {
        fprintf(stderr,
                libpq_gettext("WARNING: password file \"%s\" has group or world access; permissions should be u=rw (0600) or less\n"),
                pgpassfile);
        return NULL;
    }
#else
 
    /*
     * On Win32, the directory is protected, so we don't have to check the
     * file.
     */
#endif
 
    fp = fopen(pgpassfile, "r");
    if (fp == NULL)
        return NULL;
 
    /* Use an expansible buffer to accommodate any reasonable line length */
    initPQExpBuffer(&buf);
 
    while (!feof(fp) && !ferror(fp))
    {
        /* Make sure there's a reasonable amount of room in the buffer */
        if (!enlargePQExpBuffer(&buf, 128))
            break;
 
        /* Read some data, appending it to what we already have */
        if (fgets(buf.data + buf.len, buf.maxlen - buf.len, fp) == NULL)
            break;
        buf.len += strlen(buf.data + buf.len);
 
        /* If we don't yet have a whole line, loop around to read more */
        if (!(buf.len > 0 && buf.data[buf.len - 1] == '\n') && !feof(fp))
            continue;
 
        /* ignore comments */
        if (buf.data[0] != '#')
        {
            char       *t = buf.data;
            int         len;
 
            /* strip trailing newline and carriage return */
            len = pg_strip_crlf(t);
 
            if (len > 0 &&
                (t = pwdfMatchesString(t, hostname)) != NULL &&
                (t = pwdfMatchesString(t, port)) != NULL &&
                (t = pwdfMatchesString(t, dbname)) != NULL &&
                (t = pwdfMatchesString(t, username)) != NULL)
            {
                /* Found a match. */
                char       *ret,
                           *p1,
                           *p2;
 
                ret = strdup(t);
 
                fclose(fp);
                explicit_bzero(buf.data, buf.maxlen);
                termPQExpBuffer(&buf);
 
                if (!ret)
                {
                    /* Out of memory. XXX: an error message would be nice. */
                    return NULL;
                }
 
                /* De-escape password. */
                for (p1 = p2 = ret; *p1 != ':' && *p1 != '\0'; ++p1, ++p2)
                {
                    if (*p1 == '\\' && p1[1] != '\0')
                        ++p1;
                    *p2 = *p1;
                }
                *p2 = '\0';
 
                return ret;
            }
        }
 
        /* No match, reset buffer to prepare for next line. */
        buf.len = 0;
    }
 
    fclose(fp);
    explicit_bzero(buf.data, buf.maxlen);
    termPQExpBuffer(&buf);
    return NULL;
}

References buf, dbname, DEFAULT_PGSOCKET_DIR, DefaultHost, enlargePQExpBuffer(), explicit_bzero(), fprintf, hostname, initPQExpBuffer(), is_unixsock_path(), len, libpq_gettext, p2, pg_strip_crlf(), port, pwdfMatchesString(), S_IRWXG, S_IRWXO, S_ISREG, stat::st_mode, stat, termPQExpBuffer(), and username.

Referenced by connectOptions2().

pgpassfileWarning()

static void pgpassfileWarning ( PGconn *  conn )

static

Definition at line 7138 of file fe-connect.c.

{
    /* If it was 'invalid authorization', add pgpassfile mention */
    /* only works with >= 9.0 servers */
    if (conn->password_needed &&
        conn->connhost[conn->whichhost].password != NULL &&
        conn->result)
    {
        const char *sqlstate = PQresultErrorField(conn->result,
                                                  PG_DIAG_SQLSTATE);
 
        if (sqlstate && strcmp(sqlstate, ERRCODE_INVALID_PASSWORD) == 0)
            libpq_append_conn_error(conn, "password retrieved from file \"%s\"",
                              conn->pgpassfile);
    }
}

References conn, pg_conn::connhost, ERRCODE_INVALID_PASSWORD, libpq_append_conn_error(), pg_conn_host::password, pg_conn::password_needed, PG_DIAG_SQLSTATE, pg_conn::pgpassfile, PQresultErrorField(), pg_conn::result, and pg_conn::whichhost.

Referenced by PQconnectPoll().

PQbackendPID()

int PQbackendPID

(

const PGconn *

conn

)

Definition at line 6777 of file fe-connect.c.

{
    if (!conn || conn->status != CONNECTION_OK)
        return 0;
    return conn->be_pid;
}

References pg_conn::be_pid, conn, CONNECTION_OK, and pg_conn::status.

Referenced by get_prompt(), libpqrcv_get_backend_pid(), main(), and StartLogStreamer().

PQcancel()

int PQcancel	(	PGcancel *	cancel,
		char *	errbuf,
		int	errbufsize
	)

Definition at line 4349 of file fe-connect.c.

{
    int         save_errno = SOCK_ERRNO;
    pgsocket    tmpsock = PGINVALID_SOCKET;
    int         maxlen;
    struct
    {
        uint32      packetlen;
        CancelRequestPacket cp;
    }           crp;
 
    if (!cancel)
    {
        strlcpy(errbuf, "PQcancel() -- no cancel object supplied", errbufsize);
        /* strlcpy probably doesn't change errno, but be paranoid */
        SOCK_ERRNO_SET(save_errno);
        return false;
    }
 
    /*
     * We need to open a temporary connection to the postmaster. Do this with
     * only kernel calls.
     */
    if ((tmpsock = socket(cancel->raddr.addr.ss_family, SOCK_STREAM, 0)) == PGINVALID_SOCKET)
    {
        strlcpy(errbuf, "PQcancel() -- socket() failed: ", errbufsize);
        goto cancel_errReturn;
    }
 
    /*
     * Since this connection will only be used to send a single packet of
     * data, we don't need NODELAY.  We also don't set the socket to
     * nonblocking mode, because the API definition of PQcancel requires the
     * cancel to be sent in a blocking way.
     *
     * We do set socket options related to keepalives and other TCP timeouts.
     * This ensures that this function does not block indefinitely when
     * reasonable keepalive and timeout settings have been provided.
     */
    if (cancel->raddr.addr.ss_family != AF_UNIX &&
        cancel->keepalives != 0)
    {
#ifndef WIN32
        if (!optional_setsockopt(tmpsock, SOL_SOCKET, SO_KEEPALIVE, 1))
        {
            strlcpy(errbuf, "PQcancel() -- setsockopt(SO_KEEPALIVE) failed: ", errbufsize);
            goto cancel_errReturn;
        }
 
#ifdef PG_TCP_KEEPALIVE_IDLE
        if (!optional_setsockopt(tmpsock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
                                 cancel->keepalives_idle))
        {
            strlcpy(errbuf, "PQcancel() -- setsockopt(" PG_TCP_KEEPALIVE_IDLE_STR ") failed: ", errbufsize);
            goto cancel_errReturn;
        }
#endif
 
#ifdef TCP_KEEPINTVL
        if (!optional_setsockopt(tmpsock, IPPROTO_TCP, TCP_KEEPINTVL,
                                 cancel->keepalives_interval))
        {
            strlcpy(errbuf, "PQcancel() -- setsockopt(TCP_KEEPINTVL) failed: ", errbufsize);
            goto cancel_errReturn;
        }
#endif
 
#ifdef TCP_KEEPCNT
        if (!optional_setsockopt(tmpsock, IPPROTO_TCP, TCP_KEEPCNT,
                                 cancel->keepalives_count))
        {
            strlcpy(errbuf, "PQcancel() -- setsockopt(TCP_KEEPCNT) failed: ", errbufsize);
            goto cancel_errReturn;
        }
#endif
 
#else                           /* WIN32 */
 
#ifdef SIO_KEEPALIVE_VALS
        if (!setKeepalivesWin32(tmpsock,
                                cancel->keepalives_idle,
                                cancel->keepalives_interval))
        {
            strlcpy(errbuf, "PQcancel() -- WSAIoctl(SIO_KEEPALIVE_VALS) failed: ", errbufsize);
            goto cancel_errReturn;
        }
#endif                          /* SIO_KEEPALIVE_VALS */
#endif                          /* WIN32 */
 
        /* TCP_USER_TIMEOUT works the same way on Unix and Windows */
#ifdef TCP_USER_TIMEOUT
        if (!optional_setsockopt(tmpsock, IPPROTO_TCP, TCP_USER_TIMEOUT,
                                 cancel->pgtcp_user_timeout))
        {
            strlcpy(errbuf, "PQcancel() -- setsockopt(TCP_USER_TIMEOUT) failed: ", errbufsize);
            goto cancel_errReturn;
        }
#endif
    }
 
retry3:
    if (connect(tmpsock, (struct sockaddr *) &cancel->raddr.addr,
                cancel->raddr.salen) < 0)
    {
        if (SOCK_ERRNO == EINTR)
            /* Interrupted system call - we'll just try again */
            goto retry3;
        strlcpy(errbuf, "PQcancel() -- connect() failed: ", errbufsize);
        goto cancel_errReturn;
    }
 
    /* Create and send the cancel request packet. */
 
    crp.packetlen = pg_hton32((uint32) sizeof(crp));
    crp.cp.cancelRequestCode = (MsgType) pg_hton32(CANCEL_REQUEST_CODE);
    crp.cp.backendPID = pg_hton32(cancel->be_pid);
    crp.cp.cancelAuthCode = pg_hton32(cancel->be_key);
 
retry4:
    if (send(tmpsock, (char *) &crp, sizeof(crp), 0) != (int) sizeof(crp))
    {
        if (SOCK_ERRNO == EINTR)
            /* Interrupted system call - we'll just try again */
            goto retry4;
        strlcpy(errbuf, "PQcancel() -- send() failed: ", errbufsize);
        goto cancel_errReturn;
    }
 
    /*
     * Wait for the postmaster to close the connection, which indicates that
     * it's processed the request.  Without this delay, we might issue another
     * command only to find that our cancel zaps that command instead of the
     * one we thought we were canceling.  Note we don't actually expect this
     * read to obtain any data, we are just waiting for EOF to be signaled.
     */
retry5:
    if (recv(tmpsock, (char *) &crp, 1, 0) < 0)
    {
        if (SOCK_ERRNO == EINTR)
            /* Interrupted system call - we'll just try again */
            goto retry5;
        /* we ignore other error conditions */
    }
 
    /* All done */
    closesocket(tmpsock);
    SOCK_ERRNO_SET(save_errno);
    return true;
 
cancel_errReturn:
 
    /*
     * Make sure we don't overflow the error buffer. Leave space for the \n at
     * the end, and for the terminating zero.
     */
    maxlen = errbufsize - strlen(errbuf) - 2;
    if (maxlen >= 0)
    {
        /*
         * We can't invoke strerror here, since it's not signal-safe.  Settle
         * for printing the decimal value of errno.  Even that has to be done
         * the hard way.
         */
        int         val = SOCK_ERRNO;
        char        buf[32];
        char       *bufp;
 
        bufp = buf + sizeof(buf) - 1;
        *bufp = '\0';
        do
        {
            *(--bufp) = (val % 10) + '0';
            val /= 10;
        } while (val > 0);
        bufp -= 6;
        memcpy(bufp, "error ", 6);
        strncat(errbuf, bufp, maxlen);
        strcat(errbuf, "\n");
    }
    if (tmpsock != PGINVALID_SOCKET)
        closesocket(tmpsock);
    SOCK_ERRNO_SET(save_errno);
    return false;
}

References SockAddr::addr, pg_cancel::be_key, pg_cancel::be_pid, buf, CANCEL_REQUEST_CODE, closesocket, connect, EINTR, pg_cancel::keepalives, pg_cancel::keepalives_count, pg_cancel::keepalives_idle, pg_cancel::keepalives_interval, optional_setsockopt(), pg_hton32, PGINVALID_SOCKET, pg_cancel::pgtcp_user_timeout, pg_cancel::raddr, recv, SockAddr::salen, send, SOCK_ERRNO, SOCK_ERRNO_SET, socket, strlcpy(), and val.

Referenced by dblink_cancel_query(), DisconnectDatabase(), disconnectDatabase(), handle_sigint(), pgfdw_cancel_query(), PQrequestCancel(), ShutdownWorkersHard(), sigTermHandler(), and try_complete_step().

PQclientEncoding()

int PQclientEncoding

(

const PGconn *

conn

)

Definition at line 6820 of file fe-connect.c.

{
    if (!conn || conn->status != CONNECTION_OK)
        return -1;
    return conn->client_encoding;
}

References pg_conn::client_encoding, conn, CONNECTION_OK, and pg_conn::status.

Referenced by appendQualifiedRelation(), appendStringLiteralConn(), dblink_connect(), dblink_get_conn(), exec_command_encoding(), main(), processSQLNamePattern(), SendQuery(), setup_connection(), SyncVariables(), and vacuum_one_database().

PQconndefaults()

PQconninfoOption* PQconndefaults

(

void

)

Definition at line 1447 of file fe-connect.c.

{
    PQExpBufferData errorBuf;
    PQconninfoOption *connOptions;
 
    /* We don't actually report any errors here, but callees want a buffer */
    initPQExpBuffer(&errorBuf);
    if (PQExpBufferDataBroken(errorBuf))
        return NULL;            /* out of memory already :-( */
 
    connOptions = conninfo_init(&errorBuf);
    if (connOptions != NULL)
    {
        /* pass NULL errorBuf to ignore errors */
        if (!conninfo_add_defaults(connOptions, NULL))
        {
            PQconninfoFree(connOptions);
            connOptions = NULL;
        }
    }
 
    termPQExpBuffer(&errorBuf);
    return connOptions;
}

References conninfo_add_defaults(), conninfo_init(), initPQExpBuffer(), PQconninfoFree(), PQExpBufferDataBroken, and termPQExpBuffer().

Referenced by check_pghost_envvar(), dblink_fdw_validator(), do_connect(), get_connect_string(), InitPgFdwOptions(), and main().

PQconnectdb()

PGconn* PQconnectdb

(

const char *

conninfo

)

Definition at line 707 of file fe-connect.c.

{
    PGconn     *conn = PQconnectStart(conninfo);
 
    if (conn && conn->status != CONNECTION_BAD)
        (void) connectDBComplete(conn);
 
    return conn;
}

References conn, connectDBComplete(), CONNECTION_BAD, PQconnectStart(), and pg_conn::status.

Referenced by dblink_connect(), dblink_get_conn(), get_db_conn(), and main().

PQconnectdbParams()

PGconn* PQconnectdbParams	(	const char *const *	keywords,
		const char *const *	values,
		int	expand_dbname
	)

Definition at line 652 of file fe-connect.c.

{
    PGconn     *conn = PQconnectStartParams(keywords, values, expand_dbname);
 
    if (conn && conn->status != CONNECTION_BAD)
        (void) connectDBComplete(conn);
 
    return conn;
}

References conn, connectDBComplete(), CONNECTION_BAD, PQconnectStartParams(), pg_conn::status, and values.

Referenced by connect_pg_server(), ConnectDatabase(), connectDatabase(), do_connect(), doConnect(), ECPGconnect(), GetConnection(), main(), sql_conn(), and vacuumlo().

PQconnectionNeedsPassword()

int PQconnectionNeedsPassword

(

const PGconn *

conn

)

Definition at line 6794 of file fe-connect.c.

{
    char       *password;
 
    if (!conn)
        return false;
    password = PQpass(conn);
    if (conn->password_needed &&
        (password == NULL || password[0] == '\0'))
        return true;
    else
        return false;
}

References conn, password, pg_conn::password_needed, and PQpass().

Referenced by ConnectDatabase(), connectDatabase(), do_connect(), doConnect(), GetConnection(), main(), sql_conn(), and vacuumlo().

PQconnectionUsedPassword()

int PQconnectionUsedPassword

(

const PGconn *

conn

)

Definition at line 6809 of file fe-connect.c.

{
    if (!conn)
        return false;
    if (conn->password_needed)
        return true;
    else
        return false;
}

References conn, and pg_conn::password_needed.

Referenced by connect_pg_server(), ConnectDatabase(), and dblink_security_check().

PQconnectPoll()

PostgresPollingStatusType PQconnectPoll

(

PGconn *

conn

)

Definition at line 2210 of file fe-connect.c.

{
    bool        reset_connection_state_machine = false;
    bool        need_new_connection = false;
    PGresult   *res;
    char        sebuf[PG_STRERROR_R_BUFLEN];
    int         optval;
 
    if (conn == NULL)
        return PGRES_POLLING_FAILED;
 
    /* Get the new data */
    switch (conn->status)
    {
            /*
             * We really shouldn't have been polled in these two cases, but we
             * can handle it.
             */
        case CONNECTION_BAD:
            return PGRES_POLLING_FAILED;
        case CONNECTION_OK:
            return PGRES_POLLING_OK;
 
            /* These are reading states */
        case CONNECTION_AWAITING_RESPONSE:
        case CONNECTION_AUTH_OK:
        case CONNECTION_CHECK_WRITABLE:
        case CONNECTION_CONSUME:
        case CONNECTION_CHECK_STANDBY:
            {
                /* Load waiting data */
                int         n = pqReadData(conn);
 
                if (n < 0)
                    goto error_return;
                if (n == 0)
                    return PGRES_POLLING_READING;
 
                break;
            }
 
            /* These are writing states, so we just proceed. */
        case CONNECTION_STARTED:
        case CONNECTION_MADE:
            break;
 
            /* Special cases: proceed without waiting. */
        case CONNECTION_SSL_STARTUP:
        case CONNECTION_NEEDED:
        case CONNECTION_GSS_STARTUP:
        case CONNECTION_CHECK_TARGET:
            break;
 
        default:
            libpq_append_conn_error(conn, "invalid connection state, probably indicative of memory corruption");
            goto error_return;
    }
 
 
keep_going:                     /* We will come back to here until there is
                                 * nothing left to do. */
 
    /* Time to advance to next address, or next host if no more addresses? */
    if (conn->try_next_addr)
    {
        if (conn->addr_cur && conn->addr_cur->ai_next)
        {
            conn->addr_cur = conn->addr_cur->ai_next;
            reset_connection_state_machine = true;
        }
        else
            conn->try_next_host = true;
        conn->try_next_addr = false;
    }
 
    /* Time to advance to next connhost[] entry? */
    if (conn->try_next_host)
    {
        pg_conn_host *ch;
        struct addrinfo hint;
        int         thisport;
        int         ret;
        char        portstr[MAXPGPATH];
 
        if (conn->whichhost + 1 < conn->nconnhost)
            conn->whichhost++;
        else
        {
            /*
             * Oops, no more hosts.
             *
             * If we are trying to connect in "prefer-standby" mode, then drop
             * the standby requirement and start over.
             *
             * Otherwise, an appropriate error message is already set up, so
             * we just need to set the right status.
             */
            if (conn->target_server_type == SERVER_TYPE_PREFER_STANDBY &&
                conn->nconnhost > 0)
            {
                conn->target_server_type = SERVER_TYPE_PREFER_STANDBY_PASS2;
                conn->whichhost = 0;
            }
            else
                goto error_return;
        }
 
        /* Drop any address info for previous host */
        release_conn_addrinfo(conn);
 
        /*
         * Look up info for the new host.  On failure, log the problem in
         * conn->errorMessage, then loop around to try the next host.  (Note
         * we don't clear try_next_host until we've succeeded.)
         */
        ch = &conn->connhost[conn->whichhost];
 
        /* Initialize hint structure */
        MemSet(&hint, 0, sizeof(hint));
        hint.ai_socktype = SOCK_STREAM;
        conn->addrlist_family = hint.ai_family = AF_UNSPEC;
 
        /* Figure out the port number we're going to use. */
        if (ch->port == NULL || ch->port[0] == '\0')
            thisport = DEF_PGPORT;
        else
        {
            if (!parse_int_param(ch->port, &thisport, conn, "port"))
                goto error_return;
 
            if (thisport < 1 || thisport > 65535)
            {
                libpq_append_conn_error(conn, "invalid port number: \"%s\"", ch->port);
                goto keep_going;
            }
        }
        snprintf(portstr, sizeof(portstr), "%d", thisport);
 
        /* Use pg_getaddrinfo_all() to resolve the address */
        switch (ch->type)
        {
            case CHT_HOST_NAME:
                ret = pg_getaddrinfo_all(ch->host, portstr, &hint,
                                         &conn->addrlist);
                if (ret || !conn->addrlist)
                {
                    libpq_append_conn_error(conn, "could not translate host name \"%s\" to address: %s",
                                       ch->host, gai_strerror(ret));
                    goto keep_going;
                }
                break;
 
            case CHT_HOST_ADDRESS:
                hint.ai_flags = AI_NUMERICHOST;
                ret = pg_getaddrinfo_all(ch->hostaddr, portstr, &hint,
                                         &conn->addrlist);
                if (ret || !conn->addrlist)
                {
                    libpq_append_conn_error(conn, "could not parse network address \"%s\": %s",
                                       ch->hostaddr, gai_strerror(ret));
                    goto keep_going;
                }
                break;
 
            case CHT_UNIX_SOCKET:
                conn->addrlist_family = hint.ai_family = AF_UNIX;
                UNIXSOCK_PATH(portstr, thisport, ch->host);
                if (strlen(portstr) >= UNIXSOCK_PATH_BUFLEN)
                {
                    libpq_append_conn_error(conn, "Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
                                       portstr,
                                       (int) (UNIXSOCK_PATH_BUFLEN - 1));
                    goto keep_going;
                }
 
                /*
                 * NULL hostname tells pg_getaddrinfo_all to parse the service
                 * name as a Unix-domain socket path.
                 */
                ret = pg_getaddrinfo_all(NULL, portstr, &hint,
                                         &conn->addrlist);
                if (ret || !conn->addrlist)
                {
                    libpq_append_conn_error(conn, "could not translate Unix-domain socket path \"%s\" to address: %s",
                                       portstr, gai_strerror(ret));
                    goto keep_going;
                }
                break;
        }
 
        /* OK, scan this addrlist for a working server address */
        conn->addr_cur = conn->addrlist;
        reset_connection_state_machine = true;
        conn->try_next_host = false;
    }
 
    /* Reset connection state machine? */
    if (reset_connection_state_machine)
    {
        /*
         * (Re) initialize our connection control variables for a set of
         * connection attempts to a single server address.  These variables
         * must persist across individual connection attempts, but we must
         * reset them when we start to consider a new server.
         */
        conn->pversion = PG_PROTOCOL(3, 0);
        conn->send_appname = true;
#ifdef USE_SSL
        /* initialize these values based on SSL mode */
        conn->allow_ssl_try = (conn->sslmode[0] != 'd');    /* "disable" */
        conn->wait_ssl_try = (conn->sslmode[0] == 'a'); /* "allow" */
#endif
#ifdef ENABLE_GSS
        conn->try_gss = (conn->gssencmode[0] != 'd');   /* "disable" */
#endif
 
        reset_connection_state_machine = false;
        need_new_connection = true;
    }
 
    /* Force a new connection (perhaps to the same server as before)? */
    if (need_new_connection)
    {
        /* Drop any existing connection */
        pqDropConnection(conn, true);
 
        /* Reset all state obtained from old server */
        pqDropServerData(conn);
 
        /* Drop any PGresult we might have, too */
        conn->asyncStatus = PGASYNC_IDLE;
        conn->xactStatus = PQTRANS_IDLE;
        conn->pipelineStatus = PQ_PIPELINE_OFF;
        pqClearAsyncResult(conn);
 
        /* Reset conn->status to put the state machine in the right state */
        conn->status = CONNECTION_NEEDED;
 
        need_new_connection = false;
    }
 
    /* Now try to advance the state machine for this connection */
    switch (conn->status)
    {
        case CONNECTION_NEEDED:
            {
                /*
                 * Try to initiate a connection to one of the addresses
                 * returned by pg_getaddrinfo_all().  conn->addr_cur is the
                 * next one to try.
                 *
                 * The extra level of braces here is historical.  It's not
                 * worth reindenting this whole switch case to remove 'em.
                 */
                {
                    struct addrinfo *addr_cur = conn->addr_cur;
                    char        host_addr[NI_MAXHOST];
 
                    /*
                     * Advance to next possible host, if we've tried all of
                     * the addresses for the current host.
                     */
                    if (addr_cur == NULL)
                    {
                        conn->try_next_host = true;
                        goto keep_going;
                    }
 
                    /* Remember current address for possible use later */
                    memcpy(&conn->raddr.addr, addr_cur->ai_addr,
                           addr_cur->ai_addrlen);
                    conn->raddr.salen = addr_cur->ai_addrlen;
 
                    /*
                     * Set connip, too.  Note we purposely ignore strdup
                     * failure; not a big problem if it fails.
                     */
                    if (conn->connip != NULL)
                    {
                        free(conn->connip);
                        conn->connip = NULL;
                    }
                    getHostaddr(conn, host_addr, NI_MAXHOST);
                    if (host_addr[0])
                        conn->connip = strdup(host_addr);
 
                    /* Try to create the socket */
                    conn->sock = socket(addr_cur->ai_family, SOCK_STREAM, 0);
                    if (conn->sock == PGINVALID_SOCKET)
                    {
                        int         errorno = SOCK_ERRNO;
 
                        /*
                         * Silently ignore socket() failure if we have more
                         * addresses to try; this reduces useless chatter in
                         * cases where the address list includes both IPv4 and
                         * IPv6 but kernel only accepts one family.
                         */
                        if (addr_cur->ai_next != NULL ||
                            conn->whichhost + 1 < conn->nconnhost)
                        {
                            conn->try_next_addr = true;
                            goto keep_going;
                        }
                        emitHostIdentityInfo(conn, host_addr);
                        libpq_append_conn_error(conn, "could not create socket: %s",
                                           SOCK_STRERROR(errorno, sebuf, sizeof(sebuf)));
                        goto error_return;
                    }
 
                    /*
                     * Once we've identified a target address, all errors
                     * except the preceding socket()-failure case should be
                     * prefixed with host-identity information.  (If the
                     * connection succeeds, the contents of conn->errorMessage
                     * won't matter, so this is harmless.)
                     */
                    emitHostIdentityInfo(conn, host_addr);
 
                    /*
                     * Select socket options: no delay of outgoing data for
                     * TCP sockets, nonblock mode, close-on-exec.  Try the
                     * next address if any of this fails.
                     */
                    if (addr_cur->ai_family != AF_UNIX)
                    {
                        if (!connectNoDelay(conn))
                        {
                            /* error message already created */
                            conn->try_next_addr = true;
                            goto keep_going;
                        }
                    }
                    if (!pg_set_noblock(conn->sock))
                    {
                        libpq_append_conn_error(conn, "could not set socket to nonblocking mode: %s",
                                           SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
                        conn->try_next_addr = true;
                        goto keep_going;
                    }
 
#ifdef F_SETFD
                    if (fcntl(conn->sock, F_SETFD, FD_CLOEXEC) == -1)
                    {
                        libpq_append_conn_error(conn, "could not set socket to close-on-exec mode: %s",
                                           SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
                        conn->try_next_addr = true;
                        goto keep_going;
                    }
#endif                          /* F_SETFD */
 
                    if (addr_cur->ai_family != AF_UNIX)
                    {
#ifndef WIN32
                        int         on = 1;
#endif
                        int         usekeepalives = useKeepalives(conn);
                        int         err = 0;
 
                        if (usekeepalives < 0)
                        {
                            libpq_append_conn_error(conn, "keepalives parameter must be an integer");
                            err = 1;
                        }
                        else if (usekeepalives == 0)
                        {
                            /* Do nothing */
                        }
#ifndef WIN32
                        else if (setsockopt(conn->sock,
                                            SOL_SOCKET, SO_KEEPALIVE,
                                            (char *) &on, sizeof(on)) < 0)
                        {
                            libpq_append_conn_error(conn, "%s(%s) failed: %s",
                                               "setsockopt",
                                               "SO_KEEPALIVE",
                                               SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
                            err = 1;
                        }
                        else if (!setKeepalivesIdle(conn)
                                 || !setKeepalivesInterval(conn)
                                 || !setKeepalivesCount(conn))
                            err = 1;
#else                           /* WIN32 */
#ifdef SIO_KEEPALIVE_VALS
                        else if (!prepKeepalivesWin32(conn))
                            err = 1;
#endif                          /* SIO_KEEPALIVE_VALS */
#endif                          /* WIN32 */
                        else if (!setTCPUserTimeout(conn))
                            err = 1;
 
                        if (err)
                        {
                            conn->try_next_addr = true;
                            goto keep_going;
                        }
                    }
 
                    /*----------
                     * We have three methods of blocking SIGPIPE during
                     * send() calls to this socket:
                     *
                     *  - setsockopt(sock, SO_NOSIGPIPE)
                     *  - send(sock, ..., MSG_NOSIGNAL)
                     *  - setting the signal mask to SIG_IGN during send()
                     *
                     * The third method requires three syscalls per send,
                     * so we prefer either of the first two, but they are
                     * less portable.  The state is tracked in the following
                     * members of PGconn:
                     *
                     * conn->sigpipe_so     - we have set up SO_NOSIGPIPE
                     * conn->sigpipe_flag   - we're specifying MSG_NOSIGNAL
                     *
                     * If we can use SO_NOSIGPIPE, then set sigpipe_so here
                     * and we're done.  Otherwise, set sigpipe_flag so that
                     * we will try MSG_NOSIGNAL on sends.  If we get an error
                     * with MSG_NOSIGNAL, we'll clear that flag and revert to
                     * signal masking.
                     *----------
                     */
                    conn->sigpipe_so = false;
#ifdef MSG_NOSIGNAL
                    conn->sigpipe_flag = true;
#else
                    conn->sigpipe_flag = false;
#endif                          /* MSG_NOSIGNAL */
 
#ifdef SO_NOSIGPIPE
                    optval = 1;
                    if (setsockopt(conn->sock, SOL_SOCKET, SO_NOSIGPIPE,
                                   (char *) &optval, sizeof(optval)) == 0)
                    {
                        conn->sigpipe_so = true;
                        conn->sigpipe_flag = false;
                    }
#endif                          /* SO_NOSIGPIPE */
 
                    /*
                     * Start/make connection.  This should not block, since we
                     * are in nonblock mode.  If it does, well, too bad.
                     */
                    if (connect(conn->sock, addr_cur->ai_addr,
                                addr_cur->ai_addrlen) < 0)
                    {
                        if (SOCK_ERRNO == EINPROGRESS ||
#ifdef WIN32
                            SOCK_ERRNO == EWOULDBLOCK ||
#endif
                            SOCK_ERRNO == EINTR)
                        {
                            /*
                             * This is fine - we're in non-blocking mode, and
                             * the connection is in progress.  Tell caller to
                             * wait for write-ready on socket.
                             */
                            conn->status = CONNECTION_STARTED;
                            return PGRES_POLLING_WRITING;
                        }
                        /* otherwise, trouble */
                    }
                    else
                    {
                        /*
                         * Hm, we're connected already --- seems the "nonblock
                         * connection" wasn't.  Advance the state machine and
                         * go do the next stuff.
                         */
                        conn->status = CONNECTION_STARTED;
                        goto keep_going;
                    }
 
                    /*
                     * This connection failed.  Add the error report to
                     * conn->errorMessage, then try the next address if any.
                     */
                    connectFailureMessage(conn, SOCK_ERRNO);
                    conn->try_next_addr = true;
                    goto keep_going;
                }
            }
 
        case CONNECTION_STARTED:
            {
                socklen_t   optlen = sizeof(optval);
 
                /*
                 * Write ready, since we've made it here, so the connection
                 * has been made ... or has failed.
                 */
 
                /*
                 * Now check (using getsockopt) that there is not an error
                 * state waiting for us on the socket.
                 */
 
                if (getsockopt(conn->sock, SOL_SOCKET, SO_ERROR,
                               (char *) &optval, &optlen) == -1)
                {
                    libpq_append_conn_error(conn, "could not get socket error status: %s",
                                       SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
                    goto error_return;
                }
                else if (optval != 0)
                {
                    /*
                     * When using a nonblocking connect, we will typically see
                     * connect failures at this point, so provide a friendly
                     * error message.
                     */
                    connectFailureMessage(conn, optval);
 
                    /*
                     * Try the next address if any, just as in the case where
                     * connect() returned failure immediately.
                     */
                    conn->try_next_addr = true;
                    goto keep_going;
                }
 
                /* Fill in the client address */
                conn->laddr.salen = sizeof(conn->laddr.addr);
                if (getsockname(conn->sock,
                                (struct sockaddr *) &conn->laddr.addr,
                                &conn->laddr.salen) < 0)
                {
                    libpq_append_conn_error(conn, "could not get client address from socket: %s",
                                       SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
                    goto error_return;
                }
 
                /*
                 * Make sure we can write before advancing to next step.
                 */
                conn->status = CONNECTION_MADE;
                return PGRES_POLLING_WRITING;
            }
 
        case CONNECTION_MADE:
            {
                char       *startpacket;
                int         packetlen;
 
                /*
                 * Implement requirepeer check, if requested and it's a
                 * Unix-domain socket.
                 */
                if (conn->requirepeer && conn->requirepeer[0] &&
                    conn->raddr.addr.ss_family == AF_UNIX)
                {
#ifndef WIN32
                    char       *remote_username;
#endif
                    uid_t       uid;
                    gid_t       gid;
 
                    errno = 0;
                    if (getpeereid(conn->sock, &uid, &gid) != 0)
                    {
                        /*
                         * Provide special error message if getpeereid is a
                         * stub
                         */
                        if (errno == ENOSYS)
                            libpq_append_conn_error(conn, "requirepeer parameter is not supported on this platform");
                        else
                            libpq_append_conn_error(conn, "could not get peer credentials: %s",
                                               strerror_r(errno, sebuf, sizeof(sebuf)));
                        goto error_return;
                    }
 
#ifndef WIN32
                    remote_username = pg_fe_getusername(uid,
                                                        &conn->errorMessage);
                    if (remote_username == NULL)
                        goto error_return;  /* message already logged */
 
                    if (strcmp(remote_username, conn->requirepeer) != 0)
                    {
                        libpq_append_conn_error(conn, "requirepeer specifies \"%s\", but actual peer user name is \"%s\"",
                                           conn->requirepeer, remote_username);
                        free(remote_username);
                        goto error_return;
                    }
                    free(remote_username);
#else                           /* WIN32 */
                    /* should have failed with ENOSYS above */
                    Assert(false);
#endif                          /* WIN32 */
                }
 
                if (conn->raddr.addr.ss_family == AF_UNIX)
                {
                    /* Don't request SSL or GSSAPI over Unix sockets */
#ifdef USE_SSL
                    conn->allow_ssl_try = false;
#endif
#ifdef ENABLE_GSS
                    conn->try_gss = false;
#endif
                }
 
#ifdef ENABLE_GSS
 
                /*
                 * If GSSAPI encryption is enabled, then call
                 * pg_GSS_have_cred_cache() which will return true if we can
                 * acquire credentials (and give us a handle to use in
                 * conn->gcred), and then send a packet to the server asking
                 * for GSSAPI Encryption (and skip past SSL negotiation and
                 * regular startup below).
                 */
                if (conn->try_gss && !conn->gctx)
                    conn->try_gss = pg_GSS_have_cred_cache(&conn->gcred);
                if (conn->try_gss && !conn->gctx)
                {
                    ProtocolVersion pv = pg_hton32(NEGOTIATE_GSS_CODE);
 
                    if (pqPacketSend(conn, 0, &pv, sizeof(pv)) != STATUS_OK)
                    {
                        libpq_append_conn_error(conn, "could not send GSSAPI negotiation packet: %s",
                                           SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
                        goto error_return;
                    }
 
                    /* Ok, wait for response */
                    conn->status = CONNECTION_GSS_STARTUP;
                    return PGRES_POLLING_READING;
                }
                else if (!conn->gctx && conn->gssencmode[0] == 'r')
                {
                    libpq_append_conn_error(conn,
                                       "GSSAPI encryption required but was impossible (possibly no credential cache, no server support, or using a local socket)");
                    goto error_return;
                }
#endif
 
#ifdef USE_SSL
 
                /*
                 * Enable the libcrypto callbacks before checking if SSL needs
                 * to be done.  This is done before sending the startup packet
                 * as depending on the type of authentication done, like MD5
                 * or SCRAM that use cryptohashes, the callbacks would be
                 * required even without a SSL connection
                 */
                if (pqsecure_initialize(conn, false, true) < 0)
                    goto error_return;
 
                /*
                 * If SSL is enabled and we haven't already got encryption of
                 * some sort running, request SSL instead of sending the
                 * startup message.
                 */
                if (conn->allow_ssl_try && !conn->wait_ssl_try &&
                    !conn->ssl_in_use
#ifdef ENABLE_GSS
                    && !conn->gssenc
#endif
                    )
                {
                    ProtocolVersion pv;
 
                    /*
                     * Send the SSL request packet.
                     *
                     * Theoretically, this could block, but it really
                     * shouldn't since we only got here if the socket is
                     * write-ready.
                     */
                    pv = pg_hton32(NEGOTIATE_SSL_CODE);
                    if (pqPacketSend(conn, 0, &pv, sizeof(pv)) != STATUS_OK)
                    {
                        libpq_append_conn_error(conn, "could not send SSL negotiation packet: %s",
                                           SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
                        goto error_return;
                    }
                    /* Ok, wait for response */
                    conn->status = CONNECTION_SSL_STARTUP;
                    return PGRES_POLLING_READING;
                }
#endif                          /* USE_SSL */
 
                /*
                 * Build the startup packet.
                 */
                startpacket = pqBuildStartupPacket3(conn, &packetlen,
                                                    EnvironmentOptions);
                if (!startpacket)
                {
                    libpq_append_conn_error(conn, "out of memory");
                    goto error_return;
                }
 
                /*
                 * Send the startup packet.
                 *
                 * Theoretically, this could block, but it really shouldn't
                 * since we only got here if the socket is write-ready.
                 */
                if (pqPacketSend(conn, 0, startpacket, packetlen) != STATUS_OK)
                {
                    libpq_append_conn_error(conn, "could not send startup packet: %s",
                                       SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
                    free(startpacket);
                    goto error_return;
                }
 
                free(startpacket);
 
                conn->status = CONNECTION_AWAITING_RESPONSE;
                return PGRES_POLLING_READING;
            }
 
            /*
             * Handle SSL negotiation: wait for postmaster messages and
             * respond as necessary.
             */
        case CONNECTION_SSL_STARTUP:
            {
#ifdef USE_SSL
                PostgresPollingStatusType pollres;
 
                /*
                 * On first time through, get the postmaster's response to our
                 * SSL negotiation packet.
                 */
                if (!conn->ssl_in_use)
                {
                    /*
                     * We use pqReadData here since it has the logic to
                     * distinguish no-data-yet from connection closure. Since
                     * conn->ssl isn't set, a plain recv() will occur.
                     */
                    char        SSLok;
                    int         rdresult;
 
                    rdresult = pqReadData(conn);
                    if (rdresult < 0)
                    {
                        /* errorMessage is already filled in */
                        goto error_return;
                    }
                    if (rdresult == 0)
                    {
                        /* caller failed to wait for data */
                        return PGRES_POLLING_READING;
                    }
                    if (pqGetc(&SSLok, conn) < 0)
                    {
                        /* should not happen really */
                        return PGRES_POLLING_READING;
                    }
                    if (SSLok == 'S')
                    {
                        /* mark byte consumed */
                        conn->inStart = conn->inCursor;
 
                        /*
                         * Set up global SSL state if required.  The crypto
                         * state has already been set if libpq took care of
                         * doing that, so there is no need to make that happen
                         * again.
                         */
                        if (pqsecure_initialize(conn, true, false) != 0)
                            goto error_return;
                    }
                    else if (SSLok == 'N')
                    {
                        /* mark byte consumed */
                        conn->inStart = conn->inCursor;
                        /* OK to do without SSL? */
                        if (conn->sslmode[0] == 'r' ||  /* "require" */
                            conn->sslmode[0] == 'v')    /* "verify-ca" or
                                                         * "verify-full" */
                        {
                            /* Require SSL, but server does not want it */
                            libpq_append_conn_error(conn, "server does not support SSL, but SSL was required");
                            goto error_return;
                        }
                        /* Otherwise, proceed with normal startup */
                        conn->allow_ssl_try = false;
                        /* We can proceed using this connection */
                        conn->status = CONNECTION_MADE;
                        return PGRES_POLLING_WRITING;
                    }
                    else if (SSLok == 'E')
                    {
                        /*
                         * Server failure of some sort, such as failure to
                         * fork a backend process.  We need to process and
                         * report the error message, which might be formatted
                         * according to either protocol 2 or protocol 3.
                         * Rather than duplicate the code for that, we flip
                         * into AWAITING_RESPONSE state and let the code there
                         * deal with it.  Note we have *not* consumed the "E"
                         * byte here.
                         */
                        conn->status = CONNECTION_AWAITING_RESPONSE;
                        goto keep_going;
                    }
                    else
                    {
                        libpq_append_conn_error(conn, "received invalid response to SSL negotiation: %c",
                                           SSLok);
                        goto error_return;
                    }
                }
 
                /*
                 * Begin or continue the SSL negotiation process.
                 */
                pollres = pqsecure_open_client(conn);
                if (pollres == PGRES_POLLING_OK)
                {
                    /*
                     * At this point we should have no data already buffered.
                     * If we do, it was received before we performed the SSL
                     * handshake, so it wasn't encrypted and indeed may have
                     * been injected by a man-in-the-middle.
                     */
                    if (conn->inCursor != conn->inEnd)
                    {
                        libpq_append_conn_error(conn, "received unencrypted data after SSL response");
                        goto error_return;
                    }
 
                    /* SSL handshake done, ready to send startup packet */
                    conn->status = CONNECTION_MADE;
                    return PGRES_POLLING_WRITING;
                }
                if (pollres == PGRES_POLLING_FAILED)
                {
                    /*
                     * Failed ... if sslmode is "prefer" then do a non-SSL
                     * retry
                     */
                    if (conn->sslmode[0] == 'p' /* "prefer" */
                        && conn->allow_ssl_try  /* redundant? */
                        && !conn->wait_ssl_try) /* redundant? */
                    {
                        /* only retry once */
                        conn->allow_ssl_try = false;
                        need_new_connection = true;
                        goto keep_going;
                    }
                    /* Else it's a hard failure */
                    goto error_return;
                }
                /* Else, return POLLING_READING or POLLING_WRITING status */
                return pollres;
#else                           /* !USE_SSL */
                /* can't get here */
                goto error_return;
#endif                          /* USE_SSL */
            }
 
        case CONNECTION_GSS_STARTUP:
            {
#ifdef ENABLE_GSS
                PostgresPollingStatusType pollres;
 
                /*
                 * If we haven't yet, get the postmaster's response to our
                 * negotiation packet
                 */
                if (conn->try_gss && !conn->gctx)
                {
                    char        gss_ok;
                    int         rdresult = pqReadData(conn);
 
                    if (rdresult < 0)
                        /* pqReadData fills in error message */
                        goto error_return;
                    else if (rdresult == 0)
                        /* caller failed to wait for data */
                        return PGRES_POLLING_READING;
                    if (pqGetc(&gss_ok, conn) < 0)
                        /* shouldn't happen... */
                        return PGRES_POLLING_READING;
 
                    if (gss_ok == 'E')
                    {
                        /*
                         * Server failure of some sort.  Assume it's a
                         * protocol version support failure, and let's see if
                         * we can't recover (if it's not, we'll get a better
                         * error message on retry).  Server gets fussy if we
                         * don't hang up the socket, though.
                         */
                        conn->try_gss = false;
                        need_new_connection = true;
                        goto keep_going;
                    }
 
                    /* mark byte consumed */
                    conn->inStart = conn->inCursor;
 
                    if (gss_ok == 'N')
                    {
                        /* Server doesn't want GSSAPI; fall back if we can */
                        if (conn->gssencmode[0] == 'r')
                        {
                            libpq_append_conn_error(conn, "server doesn't support GSSAPI encryption, but it was required");
                            goto error_return;
                        }
 
                        conn->try_gss = false;
                        /* We can proceed using this connection */
                        conn->status = CONNECTION_MADE;
                        return PGRES_POLLING_WRITING;
                    }
                    else if (gss_ok != 'G')
                    {
                        libpq_append_conn_error(conn, "received invalid response to GSSAPI negotiation: %c",
                                           gss_ok);
                        goto error_return;
                    }
                }
 
                /* Begin or continue GSSAPI negotiation */
                pollres = pqsecure_open_gss(conn);
                if (pollres == PGRES_POLLING_OK)
                {
                    /*
                     * At this point we should have no data already buffered.
                     * If we do, it was received before we performed the GSS
                     * handshake, so it wasn't encrypted and indeed may have
                     * been injected by a man-in-the-middle.
                     */
                    if (conn->inCursor != conn->inEnd)
                    {
                        libpq_append_conn_error(conn, "received unencrypted data after GSSAPI encryption response");
                        goto error_return;
                    }
 
                    /* All set for startup packet */
                    conn->status = CONNECTION_MADE;
                    return PGRES_POLLING_WRITING;
                }
                else if (pollres == PGRES_POLLING_FAILED &&
                         conn->gssencmode[0] == 'p')
                {
                    /*
                     * We failed, but we can retry on "prefer".  Have to drop
                     * the current connection to do so, though.
                     */
                    conn->try_gss = false;
                    need_new_connection = true;
                    goto keep_going;
                }
                return pollres;
#else                           /* !ENABLE_GSS */
                /* unreachable */
                goto error_return;
#endif                          /* ENABLE_GSS */
            }
 
            /*
             * Handle authentication exchange: wait for postmaster messages
             * and respond as necessary.
             */
        case CONNECTION_AWAITING_RESPONSE:
            {
                char        beresp;
                int         msgLength;
                int         avail;
                AuthRequest areq;
                int         res;
 
                /*
                 * Scan the message from current point (note that if we find
                 * the message is incomplete, we will return without advancing
                 * inStart, and resume here next time).
                 */
                conn->inCursor = conn->inStart;
 
                /* Read type byte */
                if (pqGetc(&beresp, conn))
                {
                    /* We'll come back when there is more data */
                    return PGRES_POLLING_READING;
                }
 
                /*
                 * Validate message type: we expect only an authentication
                 * request, NegotiateProtocolVersion, or an error here.
                 * Anything else probably means it's not Postgres on the other
                 * end at all.
                 */
                if (!(beresp == 'R' || beresp == 'v' || beresp == 'E'))
                {
                    libpq_append_conn_error(conn, "expected authentication request from server, but received %c",
                                       beresp);
                    goto error_return;
                }
 
                /* Read message length word */
                if (pqGetInt(&msgLength, 4, conn))
                {
                    /* We'll come back when there is more data */
                    return PGRES_POLLING_READING;
                }
 
                /*
                 * Try to validate message length before using it.
                 * Authentication requests can't be very large, although GSS
                 * auth requests may not be that small.  Same for
                 * NegotiateProtocolVersion.  Errors can be a
                 * little larger, but not huge.  If we see a large apparent
                 * length in an error, it means we're really talking to a
                 * pre-3.0-protocol server; cope.  (Before version 14, the
                 * server also used the old protocol for errors that happened
                 * before processing the startup packet.)
                 */
                if ((beresp == 'R' || beresp == 'v') && (msgLength < 8 || msgLength > 2000))
                {
                    libpq_append_conn_error(conn, "expected authentication request from server, but received %c",
                                       beresp);
                    goto error_return;
                }
 
                if (beresp == 'E' && (msgLength < 8 || msgLength > 30000))
                {
                    /* Handle error from a pre-3.0 server */
                    conn->inCursor = conn->inStart + 1; /* reread data */
                    if (pqGets_append(&conn->errorMessage, conn))
                    {
                        /* We'll come back when there is more data */
                        return PGRES_POLLING_READING;
                    }
                    /* OK, we read the message; mark data consumed */
                    conn->inStart = conn->inCursor;
 
                    /*
                     * Before 7.2, the postmaster didn't always end its
                     * messages with a newline, so add one if needed to
                     * conform to libpq conventions.
                     */
                    if (conn->errorMessage.len == 0 ||
                        conn->errorMessage.data[conn->errorMessage.len - 1] != '\n')
                    {
                        appendPQExpBufferChar(&conn->errorMessage, '\n');
                    }
 
                    goto error_return;
                }
 
                /*
                 * Can't process if message body isn't all here yet.
                 */
                msgLength -= 4;
                avail = conn->inEnd - conn->inCursor;
                if (avail < msgLength)
                {
                    /*
                     * Before returning, try to enlarge the input buffer if
                     * needed to hold the whole message; see notes in
                     * pqParseInput3.
                     */
                    if (pqCheckInBufferSpace(conn->inCursor + (size_t) msgLength,
                                             conn))
                        goto error_return;
                    /* We'll come back when there is more data */
                    return PGRES_POLLING_READING;
                }
 
                /* Handle errors. */
                if (beresp == 'E')
                {
                    if (pqGetErrorNotice3(conn, true))
                    {
                        /* We'll come back when there is more data */
                        return PGRES_POLLING_READING;
                    }
                    /* OK, we read the message; mark data consumed */
                    conn->inStart = conn->inCursor;
 
                    /*
                     * If error is "cannot connect now", try the next host if
                     * any (but we don't want to consider additional addresses
                     * for this host, nor is there much point in changing SSL
                     * or GSS mode).  This is helpful when dealing with
                     * standby servers that might not be in hot-standby state.
                     */
                    if (strcmp(conn->last_sqlstate,
                               ERRCODE_CANNOT_CONNECT_NOW) == 0)
                    {
                        conn->try_next_host = true;
                        goto keep_going;
                    }
 
                    /* Check to see if we should mention pgpassfile */
                    pgpassfileWarning(conn);
 
#ifdef ENABLE_GSS
 
                    /*
                     * If gssencmode is "prefer" and we're using GSSAPI, retry
                     * without it.
                     */
                    if (conn->gssenc && conn->gssencmode[0] == 'p')
                    {
                        /* only retry once */
                        conn->try_gss = false;
                        need_new_connection = true;
                        goto keep_going;
                    }
#endif
 
#ifdef USE_SSL
 
                    /*
                     * if sslmode is "allow" and we haven't tried an SSL
                     * connection already, then retry with an SSL connection
                     */
                    if (conn->sslmode[0] == 'a' /* "allow" */
                        && !conn->ssl_in_use
                        && conn->allow_ssl_try
                        && conn->wait_ssl_try)
                    {
                        /* only retry once */
                        conn->wait_ssl_try = false;
                        need_new_connection = true;
                        goto keep_going;
                    }
 
                    /*
                     * if sslmode is "prefer" and we're in an SSL connection,
                     * then do a non-SSL retry
                     */
                    if (conn->sslmode[0] == 'p' /* "prefer" */
                        && conn->ssl_in_use
                        && conn->allow_ssl_try  /* redundant? */
                        && !conn->wait_ssl_try) /* redundant? */
                    {
                        /* only retry once */
                        conn->allow_ssl_try = false;
                        need_new_connection = true;
                        goto keep_going;
                    }
#endif
 
                    goto error_return;
                }
                else if (beresp == 'v')
                {
                    if (pqGetNegotiateProtocolVersion3(conn))
                    {
                        goto error_return;
                    }
                    /* OK, we read the message; mark data consumed */
                    conn->inStart = conn->inCursor;
                    goto error_return;
                }
 
                /* It is an authentication request. */
                conn->auth_req_received = true;
 
                /* Get the type of request. */
                if (pqGetInt((int *) &areq, 4, conn))
                {
                    goto error_return;
                }
                msgLength -= 4;
 
                /*
                 * Process the rest of the authentication request message, and
                 * respond to it if necessary.
                 *
                 * Note that conn->pghost must be non-NULL if we are going to
                 * avoid the Kerberos code doing a hostname look-up.
                 */
                res = pg_fe_sendauth(areq, msgLength, conn);
 
                /* OK, we have processed the message; mark data consumed */
                conn->inStart = conn->inCursor;
 
                if (res != STATUS_OK)
                    goto error_return;
 
                /*
                 * Just make sure that any data sent by pg_fe_sendauth is
                 * flushed out.  Although this theoretically could block, it
                 * really shouldn't since we don't send large auth responses.
                 */
                if (pqFlush(conn))
                    goto error_return;
 
                if (areq == AUTH_REQ_OK)
                {
                    /* We are done with authentication exchange */
                    conn->status = CONNECTION_AUTH_OK;
 
                    /*
                     * Set asyncStatus so that PQgetResult will think that
                     * what comes back next is the result of a query.  See
                     * below.
                     */
                    conn->asyncStatus = PGASYNC_BUSY;
                }
 
                /* Look to see if we have more data yet. */
                goto keep_going;
            }
 
        case CONNECTION_AUTH_OK:
            {
                /*
                 * Now we expect to hear from the backend. A ReadyForQuery
                 * message indicates that startup is successful, but we might
                 * also get an Error message indicating failure. (Notice
                 * messages indicating nonfatal warnings are also allowed by
                 * the protocol, as are ParameterStatus and BackendKeyData
                 * messages.) Easiest way to handle this is to let
                 * PQgetResult() read the messages. We just have to fake it
                 * out about the state of the connection, by setting
                 * asyncStatus = PGASYNC_BUSY (done above).
                 */
 
                if (PQisBusy(conn))
                    return PGRES_POLLING_READING;
 
                res = PQgetResult(conn);
 
                /*
                 * NULL return indicating we have gone to IDLE state is
                 * expected
                 */
                if (res)
                {
                    if (res->resultStatus != PGRES_FATAL_ERROR)
                        libpq_append_conn_error(conn, "unexpected message from server during startup");
                    else if (conn->send_appname &&
                             (conn->appname || conn->fbappname))
                    {
                        /*
                         * If we tried to send application_name, check to see
                         * if the error is about that --- pre-9.0 servers will
                         * reject it at this stage of the process.  If so,
                         * close the connection and retry without sending
                         * application_name.  We could possibly get a false
                         * SQLSTATE match here and retry uselessly, but there
                         * seems no great harm in that; we'll just get the
                         * same error again if it's unrelated.
                         */
                        const char *sqlstate;
 
                        sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
                        if (sqlstate &&
                            strcmp(sqlstate, ERRCODE_APPNAME_UNKNOWN) == 0)
                        {
                            PQclear(res);
                            conn->send_appname = false;
                            need_new_connection = true;
                            goto keep_going;
                        }
                    }
 
                    /*
                     * if the resultStatus is FATAL, then conn->errorMessage
                     * already has a copy of the error; needn't copy it back.
                     * But add a newline if it's not there already, since
                     * postmaster error messages may not have one.
                     */
                    if (conn->errorMessage.len <= 0 ||
                        conn->errorMessage.data[conn->errorMessage.len - 1] != '\n')
                        appendPQExpBufferChar(&conn->errorMessage, '\n');
                    PQclear(res);
                    goto error_return;
                }
 
                /* Almost there now ... */
                conn->status = CONNECTION_CHECK_TARGET;
                goto keep_going;
            }
 
        case CONNECTION_CHECK_TARGET:
            {
                /*
                 * If a read-write, read-only, primary, or standby connection
                 * is required, see if we have one.
                 */
                if (conn->target_server_type == SERVER_TYPE_READ_WRITE ||
                    conn->target_server_type == SERVER_TYPE_READ_ONLY)
                {
                    bool        read_only_server;
 
                    /*
                     * If the server didn't report
                     * "default_transaction_read_only" or "in_hot_standby" at
                     * startup, we must determine its state by sending the
                     * query "SHOW transaction_read_only".  This GUC exists in
                     * all server versions that support 3.0 protocol.
                     */
                    if (conn->default_transaction_read_only == PG_BOOL_UNKNOWN ||
                        conn->in_hot_standby == PG_BOOL_UNKNOWN)
                    {
                        /*
                         * We use PQsendQueryContinue so that
                         * conn->errorMessage does not get cleared.  We need
                         * to preserve any error messages related to previous
                         * hosts we have tried and failed to connect to.
                         */
                        conn->status = CONNECTION_OK;
                        if (!PQsendQueryContinue(conn,
                                                 "SHOW transaction_read_only"))
                            goto error_return;
                        /* We'll return to this state when we have the answer */
                        conn->status = CONNECTION_CHECK_WRITABLE;
                        return PGRES_POLLING_READING;
                    }
 
                    /* OK, we can make the test */
                    read_only_server =
                        (conn->default_transaction_read_only == PG_BOOL_YES ||
                         conn->in_hot_standby == PG_BOOL_YES);
 
                    if ((conn->target_server_type == SERVER_TYPE_READ_WRITE) ?
                        read_only_server : !read_only_server)
                    {
                        /* Wrong server state, reject and try the next host */
                        if (conn->target_server_type == SERVER_TYPE_READ_WRITE)
                            libpq_append_conn_error(conn, "session is read-only");
                        else
                            libpq_append_conn_error(conn, "session is not read-only");
 
                        /* Close connection politely. */
                        conn->status = CONNECTION_OK;
                        sendTerminateConn(conn);
 
                        /*
                         * Try next host if any, but we don't want to consider
                         * additional addresses for this host.
                         */
                        conn->try_next_host = true;
                        goto keep_going;
                    }
                }
                else if (conn->target_server_type == SERVER_TYPE_PRIMARY ||
                         conn->target_server_type == SERVER_TYPE_STANDBY ||
                         conn->target_server_type == SERVER_TYPE_PREFER_STANDBY)
                {
                    /*
                     * If the server didn't report "in_hot_standby" at
                     * startup, we must determine its state by sending the
                     * query "SELECT pg_catalog.pg_is_in_recovery()".  Servers