pqcomm.c File Reference

#include "postgres.h"
#include <poll.h>
#include <signal.h>
#include <fcntl.h>
#include <grp.h>
#include <unistd.h>
#include <sys/file.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <netdb.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <utime.h>
#include "common/ip.h"
#include "libpq/libpq.h"
#include "miscadmin.h"
#include "port/pg_bswap.h"
#include "storage/ipc.h"
#include "utils/guc_hooks.h"
#include "utils/memutils.h"

Include dependency graph for pqcomm.c:

Go to the source code of this file.

Macros
#define	PQ_SEND_BUFFER_SIZE   8192
#define	PQ_RECV_BUFFER_SIZE   8192

Functions
static void	socket_comm_reset (void)
static void	socket_close (int code, Datum arg)
static void	socket_set_nonblocking (bool nonblocking)
static int	socket_flush (void)
static int	socket_flush_if_writable (void)
static bool	socket_is_send_pending (void)
static int	socket_putmessage (char msgtype, const char *s, size_t len)
static void	socket_putmessage_noblock (char msgtype, const char *s, size_t len)
static int	internal_putbytes (const char *s, size_t len)
static int	internal_flush (void)
static int	Lock_AF_UNIX (const char *unixSocketDir, const char *unixSocketPath)
static int	Setup_AF_UNIX (const char *sock_path)
void	pq_init (void)
int	StreamServerPort (int family, const char *hostName, unsigned short portNumber, const char *unixSocketDir, pgsocket ListenSocket[], int MaxListen)
int	StreamConnection (pgsocket server_fd, Port *port)
void	StreamClose (pgsocket sock)
void	TouchSocketFiles (void)
void	RemoveSocketFiles (void)
static int	pq_recvbuf (void)
int	pq_getbyte (void)
int	pq_peekbyte (void)
int	pq_getbyte_if_available (unsigned char *c)
int	pq_getbytes (char *s, size_t len)
static int	pq_discardbytes (size_t len)
bool	pq_buffer_has_data (void)
void	pq_startmsgread (void)
void	pq_endmsgread (void)
bool	pq_is_reading_msg (void)
int	pq_getmessage (StringInfo s, int maxlen)
int	pq_putmessage_v2 (char msgtype, const char *s, size_t len)
int	pq_getkeepalivesidle (Port *port)
int	pq_setkeepalivesidle (int idle, Port *port)
int	pq_getkeepalivesinterval (Port *port)
int	pq_setkeepalivesinterval (int interval, Port *port)
int	pq_getkeepalivescount (Port *port)
int	pq_setkeepalivescount (int count, Port *port)
int	pq_gettcpusertimeout (Port *port)
int	pq_settcpusertimeout (int timeout, Port *port)
void	assign_tcp_keepalives_idle (int newval, void *extra)
const char *	show_tcp_keepalives_idle (void)
void	assign_tcp_keepalives_interval (int newval, void *extra)
const char *	show_tcp_keepalives_interval (void)
void	assign_tcp_keepalives_count (int newval, void *extra)
const char *	show_tcp_keepalives_count (void)
void	assign_tcp_user_timeout (int newval, void *extra)
const char *	show_tcp_user_timeout (void)
bool	pq_check_connection (void)

Variables
int	Unix_socket_permissions
char *	Unix_socket_group
static List *	sock_paths = NIL
static char *	PqSendBuffer
static int	PqSendBufferSize
static int	PqSendPointer
static int	PqSendStart
static char	PqRecvBuffer [PQ_RECV_BUFFER_SIZE]
static int	PqRecvPointer
static int	PqRecvLength
static bool	PqCommBusy
static bool	PqCommReadingMsg
static const PQcommMethods	PqCommSocketMethods
const PQcommMethods *	PqCommMethods = &PqCommSocketMethods
WaitEventSet *	FeBeWaitSet

Macro Definition Documentation

PQ_RECV_BUFFER_SIZE

#define PQ_RECV_BUFFER_SIZE   8192

Definition at line 120 of file pqcomm.c.

PQ_SEND_BUFFER_SIZE

#define PQ_SEND_BUFFER_SIZE   8192

Definition at line 119 of file pqcomm.c.

Function Documentation

assign_tcp_keepalives_count()

void assign_tcp_keepalives_count	(	int	newval,
		void *	extra
	)

Definition at line 1983 of file pqcomm.c.

{
    /* See comments in assign_tcp_keepalives_idle */
    (void) pq_setkeepalivescount(newval, MyProcPort);
}

References MyProcPort, newval, and pq_setkeepalivescount().

assign_tcp_keepalives_idle()

void assign_tcp_keepalives_idle	(	int	newval,
		void *	extra
	)

Definition at line 1927 of file pqcomm.c.

{
    /*
     * The kernel API provides no way to test a value without setting it; and
     * once we set it we might fail to unset it.  So there seems little point
     * in fully implementing the check-then-assign GUC API for these
     * variables.  Instead we just do the assignment on demand.
     * pq_setkeepalivesidle reports any problems via ereport(LOG).
     *
     * This approach means that the GUC value might have little to do with the
     * actual kernel value, so we use a show_hook that retrieves the kernel
     * value rather than trusting GUC's copy.
     */
    (void) pq_setkeepalivesidle(newval, MyProcPort);
}

References MyProcPort, newval, and pq_setkeepalivesidle().

assign_tcp_keepalives_interval()

void assign_tcp_keepalives_interval	(	int	newval,
		void *	extra
	)

Definition at line 1960 of file pqcomm.c.

{
    /* See comments in assign_tcp_keepalives_idle */
    (void) pq_setkeepalivesinterval(newval, MyProcPort);
}

References MyProcPort, newval, and pq_setkeepalivesinterval().

assign_tcp_user_timeout()

void assign_tcp_user_timeout	(	int	newval,
		void *	extra
	)

Definition at line 2006 of file pqcomm.c.

{
    /* See comments in assign_tcp_keepalives_idle */
    (void) pq_settcpusertimeout(newval, MyProcPort);
}

References MyProcPort, newval, and pq_settcpusertimeout().

internal_flush()

static int internal_flush ( void  )

static

Definition at line 1335 of file pqcomm.c.

{
    static int  last_reported_send_errno = 0;
 
    char       *bufptr = PqSendBuffer + PqSendStart;
    char       *bufend = PqSendBuffer + PqSendPointer;
 
    while (bufptr < bufend)
    {
        int         r;
 
        r = secure_write(MyProcPort, bufptr, bufend - bufptr);
 
        if (r <= 0)
        {
            if (errno == EINTR)
                continue;       /* Ok if we were interrupted */
 
            /*
             * Ok if no data writable without blocking, and the socket is in
             * non-blocking mode.
             */
            if (errno == EAGAIN ||
                errno == EWOULDBLOCK)
            {
                return 0;
            }
 
            /*
             * Careful: an ereport() that tries to write to the client would
             * cause recursion to here, leading to stack overflow and core
             * dump!  This message must go *only* to the postmaster log.
             *
             * If a client disconnects while we're in the midst of output, we
             * might write quite a bit of data before we get to a safe query
             * abort point.  So, suppress duplicate log messages.
             */
            if (errno != last_reported_send_errno)
            {
                last_reported_send_errno = errno;
                ereport(COMMERROR,
                        (errcode_for_socket_access(),
                         errmsg("could not send data to client: %m")));
            }
 
            /*
             * We drop the buffered data anyway so that processing can
             * continue, even though we'll probably quit soon. We also set a
             * flag that'll cause the next CHECK_FOR_INTERRUPTS to terminate
             * the connection.
             */
            PqSendStart = PqSendPointer = 0;
            ClientConnectionLost = 1;
            InterruptPending = 1;
            return EOF;
        }
 
        last_reported_send_errno = 0;   /* reset after any successful send */
        bufptr += r;
        PqSendStart += r;
    }
 
    PqSendStart = PqSendPointer = 0;
    return 0;
}

References ClientConnectionLost, COMMERROR, EAGAIN, EINTR, ereport, errcode_for_socket_access(), errmsg(), EWOULDBLOCK, InterruptPending, MyProcPort, PqSendBuffer, PqSendPointer, PqSendStart, and secure_write().

Referenced by internal_putbytes(), socket_flush(), and socket_flush_if_writable().

internal_putbytes()

static int internal_putbytes ( const char *  s, size_t  len  )

static

Definition at line 1282 of file pqcomm.c.

{
    size_t      amount;
 
    while (len > 0)
    {
        /* If buffer is full, then flush it out */
        if (PqSendPointer >= PqSendBufferSize)
        {
            socket_set_nonblocking(false);
            if (internal_flush())
                return EOF;
        }
        amount = PqSendBufferSize - PqSendPointer;
        if (amount > len)
            amount = len;
        memcpy(PqSendBuffer + PqSendPointer, s, amount);
        PqSendPointer += amount;
        s += amount;
        len -= amount;
    }
    return 0;
}

References internal_flush(), len, PqSendBuffer, PqSendBufferSize, PqSendPointer, and socket_set_nonblocking().

Referenced by pq_putmessage_v2(), and socket_putmessage().

Lock_AF_UNIX()

static int Lock_AF_UNIX ( const char *  unixSocketDir, const char *  unixSocketPath  )

static

Definition at line 590 of file pqcomm.c.

{
    /* no lock file for abstract sockets */
    if (unixSocketPath[0] == '@')
        return STATUS_OK;
 
    /*
     * Grab an interlock file associated with the socket file.
     *
     * Note: there are two reasons for using a socket lock file, rather than
     * trying to interlock directly on the socket itself.  First, it's a lot
     * more portable, and second, it lets us remove any pre-existing socket
     * file without race conditions.
     */
    CreateSocketLockFile(unixSocketPath, true, unixSocketDir);
 
    /*
     * Once we have the interlock, we can safely delete any pre-existing
     * socket file to avoid failure at bind() time.
     */
    (void) unlink(unixSocketPath);
 
    /*
     * Remember socket file pathnames for later maintenance.
     */
    sock_paths = lappend(sock_paths, pstrdup(unixSocketPath));
 
    return STATUS_OK;
}

References CreateSocketLockFile(), lappend(), pstrdup(), sock_paths, and STATUS_OK.

Referenced by StreamServerPort().

pq_buffer_has_data()

bool pq_buffer_has_data

(

void

)

Definition at line 1133 of file pqcomm.c.

{
    return (PqRecvPointer < PqRecvLength);
}

References PqRecvLength, and PqRecvPointer.

Referenced by ProcessStartupPacket().

pq_check_connection()

bool pq_check_connection

(

void

)

Definition at line 2029 of file pqcomm.c.

{
    WaitEvent   events[FeBeWaitSetNEvents];
    int         rc;
 
    /*
     * It's OK to modify the socket event filter without restoring, because
     * all FeBeWaitSet socket wait sites do the same.
     */
    ModifyWaitEvent(FeBeWaitSet, FeBeWaitSetSocketPos, WL_SOCKET_CLOSED, NULL);
 
retry:
    rc = WaitEventSetWait(FeBeWaitSet, 0, events, lengthof(events), 0);
    for (int i = 0; i < rc; ++i)
    {
        if (events[i].events & WL_SOCKET_CLOSED)
            return false;
        if (events[i].events & WL_LATCH_SET)
        {
            /*
             * A latch event might be preventing other events from being
             * reported.  Reset it and poll again.  No need to restore it
             * because no code should expect latches to survive across
             * CHECK_FOR_INTERRUPTS().
             */
            ResetLatch(MyLatch);
            goto retry;
        }
    }
 
    return true;
}

References FeBeWaitSet, FeBeWaitSetNEvents, FeBeWaitSetSocketPos, i, lengthof, ModifyWaitEvent(), MyLatch, ResetLatch(), WaitEventSetWait(), WL_LATCH_SET, and WL_SOCKET_CLOSED.

Referenced by ProcessInterrupts().

pq_discardbytes()

static int pq_discardbytes ( size_t  len )

static

Definition at line 1104 of file pqcomm.c.

{
    size_t      amount;
 
    Assert(PqCommReadingMsg);
 
    while (len > 0)
    {
        while (PqRecvPointer >= PqRecvLength)
        {
            if (pq_recvbuf())   /* If nothing in buffer, then recv some */
                return EOF;     /* Failed to recv data */
        }
        amount = PqRecvLength - PqRecvPointer;
        if (amount > len)
            amount = len;
        PqRecvPointer += amount;
        len -= amount;
    }
    return 0;
}

References Assert(), len, pq_recvbuf(), PqCommReadingMsg, PqRecvLength, and PqRecvPointer.

Referenced by pq_getmessage().

pq_endmsgread()

void pq_endmsgread

(

void

)

Definition at line 1170 of file pqcomm.c.

{
    Assert(PqCommReadingMsg);
 
    PqCommReadingMsg = false;
}

References Assert(), and PqCommReadingMsg.

Referenced by ProcessRepliesIfAny(), and ProcessStartupPacket().

pq_getbyte()

int pq_getbyte

(

void

)

Definition at line 976 of file pqcomm.c.

{
    Assert(PqCommReadingMsg);
 
    while (PqRecvPointer >= PqRecvLength)
    {
        if (pq_recvbuf())       /* If nothing in buffer, then recv some */
            return EOF;         /* Failed to recv data */
    }
    return (unsigned char) PqRecvBuffer[PqRecvPointer++];
}

References Assert(), pq_recvbuf(), PqCommReadingMsg, PqRecvBuffer, PqRecvLength, and PqRecvPointer.

Referenced by CheckSASLAuth(), CopyGetData(), recv_password_packet(), and SocketBackend().

pq_getbyte_if_available()

int pq_getbyte_if_available

(

unsigned char *

c

)

Definition at line 1016 of file pqcomm.c.

{
    int         r;
 
    Assert(PqCommReadingMsg);
 
    if (PqRecvPointer < PqRecvLength)
    {
        *c = PqRecvBuffer[PqRecvPointer++];
        return 1;
    }
 
    /* Put the socket into non-blocking mode */
    socket_set_nonblocking(true);
 
    r = secure_read(MyProcPort, c, 1);
    if (r < 0)
    {
        /*
         * Ok if no data available without blocking or interrupted (though
         * EINTR really shouldn't happen with a non-blocking socket). Report
         * other errors.
         */
        if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
            r = 0;
        else
        {
            /*
             * Careful: an ereport() that tries to write to the client would
             * cause recursion to here, leading to stack overflow and core
             * dump!  This message must go *only* to the postmaster log.
             */
            ereport(COMMERROR,
                    (errcode_for_socket_access(),
                     errmsg("could not receive data from client: %m")));
            r = EOF;
        }
    }
    else if (r == 0)
    {
        /* EOF detected */
        r = EOF;
    }
 
    return r;
}

References Assert(), COMMERROR, EAGAIN, EINTR, ereport, errcode_for_socket_access(), errmsg(), EWOULDBLOCK, MyProcPort, PqCommReadingMsg, PqRecvBuffer, PqRecvLength, PqRecvPointer, secure_read(), and socket_set_nonblocking().

Referenced by ProcessRepliesIfAny().

pq_getbytes()

int pq_getbytes	(	char *	s,
		size_t	len
	)

Definition at line 1070 of file pqcomm.c.

{
    size_t      amount;
 
    Assert(PqCommReadingMsg);
 
    while (len > 0)
    {
        while (PqRecvPointer >= PqRecvLength)
        {
            if (pq_recvbuf())   /* If nothing in buffer, then recv some */
                return EOF;     /* Failed to recv data */
        }
        amount = PqRecvLength - PqRecvPointer;
        if (amount > len)
            amount = len;
        memcpy(s, PqRecvBuffer + PqRecvPointer, amount);
        PqRecvPointer += amount;
        s += amount;
        len -= amount;
    }
    return 0;
}

References Assert(), len, pq_recvbuf(), PqCommReadingMsg, PqRecvBuffer, PqRecvLength, and PqRecvPointer.

Referenced by pq_getmessage(), and ProcessStartupPacket().

pq_getkeepalivescount()

int pq_getkeepalivescount

(

Port *

port

)

Definition at line 1774 of file pqcomm.c.

{
#ifdef TCP_KEEPCNT
    if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
        return 0;
 
    if (port->keepalives_count != 0)
        return port->keepalives_count;
 
    if (port->default_keepalives_count == 0)
    {
        socklen_t   size = sizeof(port->default_keepalives_count);
 
        if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
                       (char *) &port->default_keepalives_count,
                       &size) < 0)
        {
            ereport(LOG,
                    (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_KEEPCNT")));
            port->default_keepalives_count = -1;    /* don't know */
        }
    }
 
    return port->default_keepalives_count;
#else
    return 0;
#endif
}

References ereport, errmsg(), LOG, and port.

Referenced by pq_setkeepalivescount(), and show_tcp_keepalives_count().

pq_getkeepalivesidle()

int pq_getkeepalivesidle

(

Port *

port

)

Definition at line 1605 of file pqcomm.c.

{
#if defined(PG_TCP_KEEPALIVE_IDLE) || defined(SIO_KEEPALIVE_VALS)
    if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
        return 0;
 
    if (port->keepalives_idle != 0)
        return port->keepalives_idle;
 
    if (port->default_keepalives_idle == 0)
    {
#ifndef WIN32
        socklen_t   size = sizeof(port->default_keepalives_idle);
 
        if (getsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
                       (char *) &port->default_keepalives_idle,
                       &size) < 0)
        {
            ereport(LOG,
                    (errmsg("%s(%s) failed: %m", "getsockopt", PG_TCP_KEEPALIVE_IDLE_STR)));
            port->default_keepalives_idle = -1; /* don't know */
        }
#else                           /* WIN32 */
        /* We can't get the defaults on Windows, so return "don't know" */
        port->default_keepalives_idle = -1;
#endif                          /* WIN32 */
    }
 
    return port->default_keepalives_idle;
#else
    return 0;
#endif
}

References ereport, errmsg(), LOG, and port.

Referenced by pq_setkeepalivesidle(), and show_tcp_keepalives_idle().

pq_getkeepalivesinterval()

int pq_getkeepalivesinterval

(

Port *

port

)

Definition at line 1690 of file pqcomm.c.

{
#if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
    if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
        return 0;
 
    if (port->keepalives_interval != 0)
        return port->keepalives_interval;
 
    if (port->default_keepalives_interval == 0)
    {
#ifndef WIN32
        socklen_t   size = sizeof(port->default_keepalives_interval);
 
        if (getsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
                       (char *) &port->default_keepalives_interval,
                       &size) < 0)
        {
            ereport(LOG,
                    (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_KEEPINTVL")));
            port->default_keepalives_interval = -1; /* don't know */
        }
#else
        /* We can't get the defaults on Windows, so return "don't know" */
        port->default_keepalives_interval = -1;
#endif                          /* WIN32 */
    }
 
    return port->default_keepalives_interval;
#else
    return 0;
#endif
}

References ereport, errmsg(), LOG, and port.

Referenced by pq_setkeepalivesinterval(), and show_tcp_keepalives_interval().

pq_getmessage()

int pq_getmessage	(	StringInfo	s,
		int	maxlen
	)

Definition at line 1208 of file pqcomm.c.

{
    int32       len;
 
    Assert(PqCommReadingMsg);
 
    resetStringInfo(s);
 
    /* Read message length word */
    if (pq_getbytes((char *) &len, 4) == EOF)
    {
        ereport(COMMERROR,
                (errcode(ERRCODE_PROTOCOL_VIOLATION),
                 errmsg("unexpected EOF within message length word")));
        return EOF;
    }
 
    len = pg_ntoh32(len);
 
    if (len < 4 || len > maxlen)
    {
        ereport(COMMERROR,
                (errcode(ERRCODE_PROTOCOL_VIOLATION),
                 errmsg("invalid message length")));
        return EOF;
    }
 
    len -= 4;                   /* discount length itself */
 
    if (len > 0)
    {
        /*
         * Allocate space for message.  If we run out of room (ridiculously
         * large message), we will elog(ERROR), but we want to discard the
         * message body so as not to lose communication sync.
         */
        PG_TRY();
        {
            enlargeStringInfo(s, len);
        }
        PG_CATCH();
        {
            if (pq_discardbytes(len) == EOF)
                ereport(COMMERROR,
                        (errcode(ERRCODE_PROTOCOL_VIOLATION),
                         errmsg("incomplete message from client")));
 
            /* we discarded the rest of the message so we're back in sync. */
            PqCommReadingMsg = false;
            PG_RE_THROW();
        }
        PG_END_TRY();
 
        /* And grab the message */
        if (pq_getbytes(s->data, len) == EOF)
        {
            ereport(COMMERROR,
                    (errcode(ERRCODE_PROTOCOL_VIOLATION),
                     errmsg("incomplete message from client")));
            return EOF;
        }
        s->len = len;
        /* Place a trailing null per StringInfo convention */
        s->data[len] = '\0';
    }
 
    /* finished reading the message. */
    PqCommReadingMsg = false;
 
    return 0;
}

References Assert(), COMMERROR, StringInfoData::data, enlargeStringInfo(), ereport, errcode(), errmsg(), StringInfoData::len, len, PG_CATCH, PG_END_TRY, pg_ntoh32, PG_RE_THROW, PG_TRY, pq_discardbytes(), pq_getbytes(), PqCommReadingMsg, and resetStringInfo().

Referenced by CheckSASLAuth(), CopyGetData(), ProcessRepliesIfAny(), recv_password_packet(), and SocketBackend().

pq_gettcpusertimeout()

int pq_gettcpusertimeout

(

Port *

port

)

Definition at line 1849 of file pqcomm.c.

{
#ifdef TCP_USER_TIMEOUT
    if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
        return 0;
 
    if (port->tcp_user_timeout != 0)
        return port->tcp_user_timeout;
 
    if (port->default_tcp_user_timeout == 0)
    {
        socklen_t   size = sizeof(port->default_tcp_user_timeout);
 
        if (getsockopt(port->sock, IPPROTO_TCP, TCP_USER_TIMEOUT,
                       (char *) &port->default_tcp_user_timeout,
                       &size) < 0)
        {
            ereport(LOG,
                    (errmsg("%s(%s) failed: %m", "getsockopt", "TCP_USER_TIMEOUT")));
            port->default_tcp_user_timeout = -1;    /* don't know */
        }
    }
 
    return port->default_tcp_user_timeout;
#else
    return 0;
#endif
}

References ereport, errmsg(), LOG, and port.

Referenced by pq_settcpusertimeout(), and show_tcp_user_timeout().

pq_init()

void pq_init

(

void

)

Definition at line 172 of file pqcomm.c.

{
    int         socket_pos PG_USED_FOR_ASSERTS_ONLY;
    int         latch_pos PG_USED_FOR_ASSERTS_ONLY;
 
    /* initialize state variables */
    PqSendBufferSize = PQ_SEND_BUFFER_SIZE;
    PqSendBuffer = MemoryContextAlloc(TopMemoryContext, PqSendBufferSize);
    PqSendPointer = PqSendStart = PqRecvPointer = PqRecvLength = 0;
    PqCommBusy = false;
    PqCommReadingMsg = false;
 
    /* set up process-exit hook to close the socket */
    on_proc_exit(socket_close, 0);
 
    /*
     * In backends (as soon as forked) we operate the underlying socket in
     * nonblocking mode and use latches to implement blocking semantics if
     * needed. That allows us to provide safely interruptible reads and
     * writes.
     *
     * Use COMMERROR on failure, because ERROR would try to send the error to
     * the client, which might require changing the mode again, leading to
     * infinite recursion.
     */
#ifndef WIN32
    if (!pg_set_noblock(MyProcPort->sock))
        ereport(COMMERROR,
                (errmsg("could not set socket to nonblocking mode: %m")));
#endif
 
#ifndef WIN32
 
    /* Don't give the socket to any subprograms we execute. */
    if (fcntl(MyProcPort->sock, F_SETFD, FD_CLOEXEC) < 0)
        elog(FATAL, "fcntl(F_SETFD) failed on socket: %m");
#endif
 
    FeBeWaitSet = CreateWaitEventSet(TopMemoryContext, FeBeWaitSetNEvents);
    socket_pos = AddWaitEventToSet(FeBeWaitSet, WL_SOCKET_WRITEABLE,
                                   MyProcPort->sock, NULL, NULL);
    latch_pos = AddWaitEventToSet(FeBeWaitSet, WL_LATCH_SET, PGINVALID_SOCKET,
                                  MyLatch, NULL);
    AddWaitEventToSet(FeBeWaitSet, WL_POSTMASTER_DEATH, PGINVALID_SOCKET,
                      NULL, NULL);
 
    /*
     * The event positions match the order we added them, but let's sanity
     * check them to be sure.
     */
    Assert(socket_pos == FeBeWaitSetSocketPos);
    Assert(latch_pos == FeBeWaitSetLatchPos);
}

References AddWaitEventToSet(), Assert(), COMMERROR, CreateWaitEventSet(), elog(), ereport, errmsg(), FATAL, FeBeWaitSet, FeBeWaitSetLatchPos, FeBeWaitSetNEvents, FeBeWaitSetSocketPos, MemoryContextAlloc(), MyLatch, MyProcPort, on_proc_exit(), pg_set_noblock(), PG_USED_FOR_ASSERTS_ONLY, PGINVALID_SOCKET, PQ_SEND_BUFFER_SIZE, PqCommBusy, PqCommReadingMsg, PqRecvLength, PqRecvPointer, PqSendBuffer, PqSendBufferSize, PqSendPointer, PqSendStart, Port::sock, socket_close(), TopMemoryContext, WL_LATCH_SET, WL_POSTMASTER_DEATH, and WL_SOCKET_WRITEABLE.

Referenced by BackendInitialize().

pq_is_reading_msg()

bool pq_is_reading_msg

(

void

)

Definition at line 1186 of file pqcomm.c.

{
    return PqCommReadingMsg;
}

References PqCommReadingMsg.

Referenced by PostgresMain().

pq_peekbyte()

int pq_peekbyte

(

void

)

Definition at line 995 of file pqcomm.c.

{
    Assert(PqCommReadingMsg);
 
    while (PqRecvPointer >= PqRecvLength)
    {
        if (pq_recvbuf())       /* If nothing in buffer, then recv some */
            return EOF;         /* Failed to recv data */
    }
    return (unsigned char) PqRecvBuffer[PqRecvPointer];
}

References Assert(), pq_recvbuf(), PqCommReadingMsg, PqRecvBuffer, PqRecvLength, and PqRecvPointer.

pq_putmessage_v2()

int pq_putmessage_v2	(	char	msgtype,
		const char *	s,
		size_t	len
	)

Definition at line 1534 of file pqcomm.c.

{
    Assert(msgtype != 0);
 
    if (PqCommBusy)
        return 0;
    PqCommBusy = true;
    if (internal_putbytes(&msgtype, 1))
        goto fail;
 
    if (internal_putbytes(s, len))
        goto fail;
    PqCommBusy = false;
    return 0;
 
fail:
    PqCommBusy = false;
    return EOF;
}

References Assert(), internal_putbytes(), len, and PqCommBusy.

Referenced by send_message_to_frontend().

pq_recvbuf()

static int pq_recvbuf ( void  )

static

Definition at line 915 of file pqcomm.c.

{
    if (PqRecvPointer > 0)
    {
        if (PqRecvLength > PqRecvPointer)
        {
            /* still some unread data, left-justify it in the buffer */
            memmove(PqRecvBuffer, PqRecvBuffer + PqRecvPointer,
                    PqRecvLength - PqRecvPointer);
            PqRecvLength -= PqRecvPointer;
            PqRecvPointer = 0;
        }
        else
            PqRecvLength = PqRecvPointer = 0;
    }
 
    /* Ensure that we're in blocking mode */
    socket_set_nonblocking(false);
 
    /* Can fill buffer from PqRecvLength and upwards */
    for (;;)
    {
        int         r;
 
        r = secure_read(MyProcPort, PqRecvBuffer + PqRecvLength,
                        PQ_RECV_BUFFER_SIZE - PqRecvLength);
 
        if (r < 0)
        {
            if (errno == EINTR)
                continue;       /* Ok if interrupted */
 
            /*
             * Careful: an ereport() that tries to write to the client would
             * cause recursion to here, leading to stack overflow and core
             * dump!  This message must go *only* to the postmaster log.
             */
            ereport(COMMERROR,
                    (errcode_for_socket_access(),
                     errmsg("could not receive data from client: %m")));
            return EOF;
        }
        if (r == 0)
        {
            /*
             * EOF detected.  We used to write a log message here, but it's
             * better to expect the ultimate caller to do that.
             */
            return EOF;
        }
        /* r contains number of bytes read, so just incr length */
        PqRecvLength += r;
        return 0;
    }
}

References COMMERROR, EINTR, ereport, errcode_for_socket_access(), errmsg(), MyProcPort, PQ_RECV_BUFFER_SIZE, PqRecvBuffer, PqRecvLength, PqRecvPointer, secure_read(), and socket_set_nonblocking().

Referenced by pq_discardbytes(), pq_getbyte(), pq_getbytes(), and pq_peekbyte().

pq_setkeepalivescount()

int pq_setkeepalivescount	(	int	count,
		Port *	port
	)

Definition at line 1804 of file pqcomm.c.

{
    if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
        return STATUS_OK;
 
#ifdef TCP_KEEPCNT
    if (count == port->keepalives_count)
        return STATUS_OK;
 
    if (port->default_keepalives_count <= 0)
    {
        if (pq_getkeepalivescount(port) < 0)
        {
            if (count == 0)
                return STATUS_OK;   /* default is set but unknown */
            else
                return STATUS_ERROR;
        }
    }
 
    if (count == 0)
        count = port->default_keepalives_count;
 
    if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPCNT,
                   (char *) &count, sizeof(count)) < 0)
    {
        ereport(LOG,
                (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_KEEPCNT")));
        return STATUS_ERROR;
    }
 
    port->keepalives_count = count;
#else
    if (count != 0)
    {
        ereport(LOG,
                (errmsg("%s(%s) not supported", "setsockopt", "TCP_KEEPCNT")));
        return STATUS_ERROR;
    }
#endif
 
    return STATUS_OK;
}

References ereport, errmsg(), LOG, port, pq_getkeepalivescount(), STATUS_ERROR, and STATUS_OK.

Referenced by assign_tcp_keepalives_count(), and StreamConnection().

pq_setkeepalivesidle()

int pq_setkeepalivesidle	(	int	idle,
		Port *	port
	)

Definition at line 1640 of file pqcomm.c.

{
    if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
        return STATUS_OK;
 
/* check SIO_KEEPALIVE_VALS here, not just WIN32, as some toolchains lack it */
#if defined(PG_TCP_KEEPALIVE_IDLE) || defined(SIO_KEEPALIVE_VALS)
    if (idle == port->keepalives_idle)
        return STATUS_OK;
 
#ifndef WIN32
    if (port->default_keepalives_idle <= 0)
    {
        if (pq_getkeepalivesidle(port) < 0)
        {
            if (idle == 0)
                return STATUS_OK;   /* default is set but unknown */
            else
                return STATUS_ERROR;
        }
    }
 
    if (idle == 0)
        idle = port->default_keepalives_idle;
 
    if (setsockopt(port->sock, IPPROTO_TCP, PG_TCP_KEEPALIVE_IDLE,
                   (char *) &idle, sizeof(idle)) < 0)
    {
        ereport(LOG,
                (errmsg("%s(%s) failed: %m", "setsockopt", PG_TCP_KEEPALIVE_IDLE_STR)));
        return STATUS_ERROR;
    }
 
    port->keepalives_idle = idle;
#else                           /* WIN32 */
    return pq_setkeepaliveswin32(port, idle, port->keepalives_interval);
#endif
#else
    if (idle != 0)
    {
        ereport(LOG,
                (errmsg("setting the keepalive idle time is not supported")));
        return STATUS_ERROR;
    }
#endif
 
    return STATUS_OK;
}

References ereport, errmsg(), LOG, port, pq_getkeepalivesidle(), STATUS_ERROR, and STATUS_OK.

Referenced by assign_tcp_keepalives_idle(), and StreamConnection().

pq_setkeepalivesinterval()

int pq_setkeepalivesinterval	(	int	interval,
		Port *	port
	)

Definition at line 1725 of file pqcomm.c.

{
    if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
        return STATUS_OK;
 
#if defined(TCP_KEEPINTVL) || defined(SIO_KEEPALIVE_VALS)
    if (interval == port->keepalives_interval)
        return STATUS_OK;
 
#ifndef WIN32
    if (port->default_keepalives_interval <= 0)
    {
        if (pq_getkeepalivesinterval(port) < 0)
        {
            if (interval == 0)
                return STATUS_OK;   /* default is set but unknown */
            else
                return STATUS_ERROR;
        }
    }
 
    if (interval == 0)
        interval = port->default_keepalives_interval;
 
    if (setsockopt(port->sock, IPPROTO_TCP, TCP_KEEPINTVL,
                   (char *) &interval, sizeof(interval)) < 0)
    {
        ereport(LOG,
                (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_KEEPINTVL")));
        return STATUS_ERROR;
    }
 
    port->keepalives_interval = interval;
#else                           /* WIN32 */
    return pq_setkeepaliveswin32(port, port->keepalives_idle, interval);
#endif
#else
    if (interval != 0)
    {
        ereport(LOG,
                (errmsg("%s(%s) not supported", "setsockopt", "TCP_KEEPINTVL")));
        return STATUS_ERROR;
    }
#endif
 
    return STATUS_OK;
}

References ereport, errmsg(), LOG, port, pq_getkeepalivesinterval(), STATUS_ERROR, and STATUS_OK.

Referenced by assign_tcp_keepalives_interval(), and StreamConnection().

pq_settcpusertimeout()

int pq_settcpusertimeout	(	int	timeout,
		Port *	port
	)

Definition at line 1879 of file pqcomm.c.

{
    if (port == NULL || port->laddr.addr.ss_family == AF_UNIX)
        return STATUS_OK;
 
#ifdef TCP_USER_TIMEOUT
    if (timeout == port->tcp_user_timeout)
        return STATUS_OK;
 
    if (port->default_tcp_user_timeout <= 0)
    {
        if (pq_gettcpusertimeout(port) < 0)
        {
            if (timeout == 0)
                return STATUS_OK;   /* default is set but unknown */
            else
                return STATUS_ERROR;
        }
    }
 
    if (timeout == 0)
        timeout = port->default_tcp_user_timeout;
 
    if (setsockopt(port->sock, IPPROTO_TCP, TCP_USER_TIMEOUT,
                   (char *) &timeout, sizeof(timeout)) < 0)
    {
        ereport(LOG,
                (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_USER_TIMEOUT")));
        return STATUS_ERROR;
    }
 
    port->tcp_user_timeout = timeout;
#else
    if (timeout != 0)
    {
        ereport(LOG,
                (errmsg("%s(%s) not supported", "setsockopt", "TCP_USER_TIMEOUT")));
        return STATUS_ERROR;
    }
#endif
 
    return STATUS_OK;
}

References ereport, errmsg(), LOG, port, pq_gettcpusertimeout(), STATUS_ERROR, and STATUS_OK.

Referenced by assign_tcp_user_timeout(), and StreamConnection().

pq_startmsgread()

void pq_startmsgread

(

void

)

Definition at line 1146 of file pqcomm.c.

{
    /*
     * There shouldn't be a read active already, but let's check just to be
     * sure.
     */
    if (PqCommReadingMsg)
        ereport(FATAL,
                (errcode(ERRCODE_PROTOCOL_VIOLATION),
                 errmsg("terminating connection because protocol synchronization was lost")));
 
    PqCommReadingMsg = true;
}

References ereport, errcode(), errmsg(), FATAL, and PqCommReadingMsg.

Referenced by CheckSASLAuth(), CopyGetData(), ProcessRepliesIfAny(), ProcessStartupPacket(), recv_password_packet(), and SocketBackend().

RemoveSocketFiles()

void RemoveSocketFiles

(

void

)

Definition at line 865 of file pqcomm.c.

{
    ListCell   *l;
 
    /* Loop through all created sockets... */
    foreach(l, sock_paths)
    {
        char       *sock_path = (char *) lfirst(l);
 
        /* Ignore any error. */
        (void) unlink(sock_path);
    }
    /* Since we're about to exit, no need to reclaim storage */
    sock_paths = NIL;
}

References lfirst, NIL, and sock_paths.

Referenced by CloseServerPorts().

Setup_AF_UNIX()

static int Setup_AF_UNIX ( const char *  sock_path )

static

Definition at line 625 of file pqcomm.c.

{
    /* no file system permissions for abstract sockets */
    if (sock_path[0] == '@')
        return STATUS_OK;
 
    /*
     * Fix socket ownership/permission if requested.  Note we must do this
     * before we listen() to avoid a window where unwanted connections could
     * get accepted.
     */
    Assert(Unix_socket_group);
    if (Unix_socket_group[0] != '\0')
    {
#ifdef WIN32
        elog(WARNING, "configuration item unix_socket_group is not supported on this platform");
#else
        char       *endptr;
        unsigned long val;
        gid_t       gid;
 
        val = strtoul(Unix_socket_group, &endptr, 10);
        if (*endptr == '\0')
        {                       /* numeric group id */
            gid = val;
        }
        else
        {                       /* convert group name to id */
            struct group *gr;
 
            gr = getgrnam(Unix_socket_group);
            if (!gr)
            {
                ereport(LOG,
                        (errmsg("group \"%s\" does not exist",
                                Unix_socket_group)));
                return STATUS_ERROR;
            }
            gid = gr->gr_gid;
        }
        if (chown(sock_path, -1, gid) == -1)
        {
            ereport(LOG,
                    (errcode_for_file_access(),
                     errmsg("could not set group of file \"%s\": %m",
                            sock_path)));
            return STATUS_ERROR;
        }
#endif
    }
 
    if (chmod(sock_path, Unix_socket_permissions) == -1)
    {
        ereport(LOG,
                (errcode_for_file_access(),
                 errmsg("could not set permissions of file \"%s\": %m",
                        sock_path)));
        return STATUS_ERROR;
    }
    return STATUS_OK;
}

References Assert(), elog(), ereport, errcode_for_file_access(), errmsg(), LOG, STATUS_ERROR, STATUS_OK, Unix_socket_group, Unix_socket_permissions, val, and WARNING.

Referenced by StreamServerPort().

show_tcp_keepalives_count()

const char* show_tcp_keepalives_count

(

void

)

Definition at line 1993 of file pqcomm.c.

{
    /* See comments in assign_tcp_keepalives_idle */
    static char nbuf[16];
 
    snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivescount(MyProcPort));
    return nbuf;
}

References MyProcPort, pq_getkeepalivescount(), and snprintf.

show_tcp_keepalives_idle()

const char* show_tcp_keepalives_idle

(

void

)

Definition at line 1947 of file pqcomm.c.

{
    /* See comments in assign_tcp_keepalives_idle */
    static char nbuf[16];
 
    snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesidle(MyProcPort));
    return nbuf;
}

References MyProcPort, pq_getkeepalivesidle(), and snprintf.

show_tcp_keepalives_interval()

const char* show_tcp_keepalives_interval

(

void

)

Definition at line 1970 of file pqcomm.c.

{
    /* See comments in assign_tcp_keepalives_idle */
    static char nbuf[16];
 
    snprintf(nbuf, sizeof(nbuf), "%d", pq_getkeepalivesinterval(MyProcPort));
    return nbuf;
}

References MyProcPort, pq_getkeepalivesinterval(), and snprintf.

show_tcp_user_timeout()

const char* show_tcp_user_timeout

(

void

)

Definition at line 2016 of file pqcomm.c.

{
    /* See comments in assign_tcp_keepalives_idle */
    static char nbuf[16];
 
    snprintf(nbuf, sizeof(nbuf), "%d", pq_gettcpusertimeout(MyProcPort));
    return nbuf;
}

References MyProcPort, pq_gettcpusertimeout(), and snprintf.

socket_close()

static void socket_close ( int  code, Datum  arg  )

static

Definition at line 250 of file pqcomm.c.

{
    /* Nothing to do in a standalone backend, where MyProcPort is NULL. */
    if (MyProcPort != NULL)
    {
#ifdef ENABLE_GSS
        /*
         * Shutdown GSSAPI layer.  This section does nothing when interrupting
         * BackendInitialize(), because pg_GSS_recvauth() makes first use of
         * "ctx" and "cred".
         *
         * Note that we don't bother to free MyProcPort->gss, since we're
         * about to exit anyway.
         */
        if (MyProcPort->gss)
        {
            OM_uint32   min_s;
 
            if (MyProcPort->gss->ctx != GSS_C_NO_CONTEXT)
                gss_delete_sec_context(&min_s, &MyProcPort->gss->ctx, NULL);
 
            if (MyProcPort->gss->cred != GSS_C_NO_CREDENTIAL)
                gss_release_cred(&min_s, &MyProcPort->gss->cred);
        }
#endif                          /* ENABLE_GSS */
 
        /*
         * Cleanly shut down SSL layer.  Nowhere else does a postmaster child
         * call this, so this is safe when interrupting BackendInitialize().
         */
        secure_close(MyProcPort);
 
        /*
         * Formerly we did an explicit close() here, but it seems better to
         * leave the socket open until the process dies.  This allows clients
         * to perform a "synchronous close" if they care --- wait till the
         * transport layer reports connection closure, and you can be sure the
         * backend has exited.
         *
         * We do set sock to PGINVALID_SOCKET to prevent any further I/O,
         * though.
         */
        MyProcPort->sock = PGINVALID_SOCKET;
    }
}

References Port::gss, MyProcPort, PGINVALID_SOCKET, secure_close(), and Port::sock.

Referenced by pq_init().

socket_comm_reset()

static void socket_comm_reset ( void  )

static

Definition at line 235 of file pqcomm.c.

{
    /* Do not throw away pending data, but do reset the busy flag */
    PqCommBusy = false;
}

References PqCommBusy.

socket_flush()

static int socket_flush ( void  )

static

Definition at line 1313 of file pqcomm.c.

{
    int         res;
 
    /* No-op if reentrant call */
    if (PqCommBusy)
        return 0;
    PqCommBusy = true;
    socket_set_nonblocking(false);
    res = internal_flush();
    PqCommBusy = false;
    return res;
}

References internal_flush(), PqCommBusy, res, and socket_set_nonblocking().

socket_flush_if_writable()

static int socket_flush_if_writable ( void  )

static

Definition at line 1408 of file pqcomm.c.

{
    int         res;
 
    /* Quick exit if nothing to do */
    if (PqSendPointer == PqSendStart)
        return 0;
 
    /* No-op if reentrant call */
    if (PqCommBusy)
        return 0;
 
    /* Temporarily put the socket into non-blocking mode */
    socket_set_nonblocking(true);
 
    PqCommBusy = true;
    res = internal_flush();
    PqCommBusy = false;
    return res;
}

References internal_flush(), PqCommBusy, PqSendPointer, PqSendStart, res, and socket_set_nonblocking().

socket_is_send_pending()

static bool socket_is_send_pending ( void  )

static

Definition at line 1434 of file pqcomm.c.

{
    return (PqSendStart < PqSendPointer);
}

References PqSendPointer, and PqSendStart.

socket_putmessage()

static int socket_putmessage ( char  msgtype, const char *  s, size_t  len  )

static

Definition at line 1464 of file pqcomm.c.

{
    uint32      n32;
 
    Assert(msgtype != 0);
 
    if (PqCommBusy)
        return 0;
    PqCommBusy = true;
    if (internal_putbytes(&msgtype, 1))
        goto fail;
 
    n32 = pg_hton32((uint32) (len + 4));
    if (internal_putbytes((char *) &n32, 4))
        goto fail;
 
    if (internal_putbytes(s, len))
        goto fail;
    PqCommBusy = false;
    return 0;
 
fail:
    PqCommBusy = false;
    return EOF;
}

References Assert(), internal_putbytes(), len, pg_hton32, and PqCommBusy.

socket_putmessage_noblock()

static void socket_putmessage_noblock ( char  msgtype, const char *  s, size_t  len  )

static

Definition at line 1497 of file pqcomm.c.

{
    int         res PG_USED_FOR_ASSERTS_ONLY;
    int         required;
 
    /*
     * Ensure we have enough space in the output buffer for the message header
     * as well as the message itself.
     */
    required = PqSendPointer + 1 + 4 + len;
    if (required > PqSendBufferSize)
    {
        PqSendBuffer = repalloc(PqSendBuffer, required);
        PqSendBufferSize = required;
    }
    res = pq_putmessage(msgtype, s, len);
    Assert(res == 0);           /* should not fail when the message fits in
                                 * buffer */
}

References Assert(), len, PG_USED_FOR_ASSERTS_ONLY, pq_putmessage, PqSendBuffer, PqSendBufferSize, PqSendPointer, repalloc(), generate_unaccent_rules::required, and res.

socket_set_nonblocking()

static void socket_set_nonblocking ( bool  nonblocking )

static

Definition at line 898 of file pqcomm.c.

{
    if (MyProcPort == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_CONNECTION_DOES_NOT_EXIST),
                 errmsg("there is no client connection")));
 
    MyProcPort->noblock = nonblocking;
}

References ereport, errcode(), errmsg(), ERROR, MyProcPort, and Port::noblock.

Referenced by internal_putbytes(), pq_getbyte_if_available(), pq_recvbuf(), socket_flush(), and socket_flush_if_writable().

StreamClose()

void StreamClose

(

pgsocket

sock

)

Definition at line 832 of file pqcomm.c.

{
    closesocket(sock);
}

References closesocket.

Referenced by ClosePostmasterPorts(), CloseServerPorts(), ConnCreate(), and ServerLoop().

StreamConnection()

int StreamConnection	(	pgsocket	server_fd,
		Port *	port
	)

Definition at line 698 of file pqcomm.c.

{
    /* accept connection and fill in the client (remote) address */
    port->raddr.salen = sizeof(port->raddr.addr);
    if ((port->sock = accept(server_fd,
                             (struct sockaddr *) &port->raddr.addr,
                             &port->raddr.salen)) == PGINVALID_SOCKET)
    {
        ereport(LOG,
                (errcode_for_socket_access(),
                 errmsg("could not accept new connection: %m")));
 
        /*
         * If accept() fails then postmaster.c will still see the server
         * socket as read-ready, and will immediately try again.  To avoid
         * uselessly sucking lots of CPU, delay a bit before trying again.
         * (The most likely reason for failure is being out of kernel file
         * table slots; we can do little except hope some will get freed up.)
         */
        pg_usleep(100000L);     /* wait 0.1 sec */
        return STATUS_ERROR;
    }
 
    /* fill in the server (local) address */
    port->laddr.salen = sizeof(port->laddr.addr);
    if (getsockname(port->sock,
                    (struct sockaddr *) &port->laddr.addr,
                    &port->laddr.salen) < 0)
    {
        ereport(LOG,
                (errmsg("%s() failed: %m", "getsockname")));
        return STATUS_ERROR;
    }
 
    /* select NODELAY and KEEPALIVE options if it's a TCP connection */
    if (port->laddr.addr.ss_family != AF_UNIX)
    {
        int         on;
#ifdef WIN32
        int         oldopt;
        int         optlen;
        int         newopt;
#endif
 
#ifdef  TCP_NODELAY
        on = 1;
        if (setsockopt(port->sock, IPPROTO_TCP, TCP_NODELAY,
                       (char *) &on, sizeof(on)) < 0)
        {
            ereport(LOG,
                    (errmsg("%s(%s) failed: %m", "setsockopt", "TCP_NODELAY")));
            return STATUS_ERROR;
        }
#endif
        on = 1;
        if (setsockopt(port->sock, SOL_SOCKET, SO_KEEPALIVE,
                       (char *) &on, sizeof(on)) < 0)
        {
            ereport(LOG,
                    (errmsg("%s(%s) failed: %m", "setsockopt", "SO_KEEPALIVE")));
            return STATUS_ERROR;
        }
 
#ifdef WIN32
 
        /*
         * This is a Win32 socket optimization.  The OS send buffer should be
         * large enough to send the whole Postgres send buffer in one go, or
         * performance suffers.  The Postgres send buffer can be enlarged if a
         * very large message needs to be sent, but we won't attempt to
         * enlarge the OS buffer if that happens, so somewhat arbitrarily
         * ensure that the OS buffer is at least PQ_SEND_BUFFER_SIZE * 4.
         * (That's 32kB with the current default).
         *
         * The default OS buffer size used to be 8kB in earlier Windows
         * versions, but was raised to 64kB in Windows 2012.  So it shouldn't
         * be necessary to change it in later versions anymore.  Changing it
         * unnecessarily can even reduce performance, because setting
         * SO_SNDBUF in the application disables the "dynamic send buffering"
         * feature that was introduced in Windows 7.  So before fiddling with
         * SO_SNDBUF, check if the current buffer size is already large enough
         * and only increase it if necessary.
         *
         * See https://support.microsoft.com/kb/823764/EN-US/ and
         * https://msdn.microsoft.com/en-us/library/bb736549%28v=vs.85%29.aspx
         */
        optlen = sizeof(oldopt);
        if (getsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &oldopt,
                       &optlen) < 0)
        {
            ereport(LOG,
                    (errmsg("%s(%s) failed: %m", "getsockopt", "SO_SNDBUF")));
            return STATUS_ERROR;
        }
        newopt = PQ_SEND_BUFFER_SIZE * 4;
        if (oldopt < newopt)
        {
            if (setsockopt(port->sock, SOL_SOCKET, SO_SNDBUF, (char *) &newopt,
                           sizeof(newopt)) < 0)
            {
                ereport(LOG,
                        (errmsg("%s(%s) failed: %m", "setsockopt", "SO_SNDBUF")));
                return STATUS_ERROR;
            }
        }
#endif
 
        /*
         * Also apply the current keepalive parameters.  If we fail to set a
         * parameter, don't error out, because these aren't universally
         * supported.  (Note: you might think we need to reset the GUC
         * variables to 0 in such a case, but it's not necessary because the
         * show hooks for these variables report the truth anyway.)
         */
        (void) pq_setkeepalivesidle(tcp_keepalives_idle, port);
        (void) pq_setkeepalivesinterval(tcp_keepalives_interval, port);
        (void) pq_setkeepalivescount(tcp_keepalives_count, port);
        (void) pq_settcpusertimeout(tcp_user_timeout, port);
    }
 
    return STATUS_OK;
}

References accept, ereport, errcode_for_socket_access(), errmsg(), LOG, pg_usleep(), PGINVALID_SOCKET, port, PQ_SEND_BUFFER_SIZE, pq_setkeepalivescount(), pq_setkeepalivesidle(), pq_setkeepalivesinterval(), pq_settcpusertimeout(), STATUS_ERROR, STATUS_OK, tcp_keepalives_count, tcp_keepalives_idle, tcp_keepalives_interval, and tcp_user_timeout.

Referenced by ConnCreate().

StreamServerPort()

int StreamServerPort	(	int	family,
		const char *	hostName,
		unsigned short	portNumber,
		const char *	unixSocketDir,
		pgsocket	ListenSocket[],
		int	MaxListen
	)

Definition at line 321 of file pqcomm.c.

{
    pgsocket    fd;
    int         err;
    int         maxconn;
    int         ret;
    char        portNumberStr[32];
    const char *familyDesc;
    char        familyDescBuf[64];
    const char *addrDesc;
    char        addrBuf[NI_MAXHOST];
    char       *service;
    struct addrinfo *addrs = NULL,
               *addr;
    struct addrinfo hint;
    int         listen_index = 0;
    int         added = 0;
    char        unixSocketPath[MAXPGPATH];
#if !defined(WIN32) || defined(IPV6_V6ONLY)
    int         one = 1;
#endif
 
    /* Initialize hint structure */
    MemSet(&hint, 0, sizeof(hint));
    hint.ai_family = family;
    hint.ai_flags = AI_PASSIVE;
    hint.ai_socktype = SOCK_STREAM;
 
    if (family == AF_UNIX)
    {
        /*
         * Create unixSocketPath from portNumber and unixSocketDir and lock
         * that file path
         */
        UNIXSOCK_PATH(unixSocketPath, portNumber, unixSocketDir);
        if (strlen(unixSocketPath) >= UNIXSOCK_PATH_BUFLEN)
        {
            ereport(LOG,
                    (errmsg("Unix-domain socket path \"%s\" is too long (maximum %d bytes)",
                            unixSocketPath,
                            (int) (UNIXSOCK_PATH_BUFLEN - 1))));
            return STATUS_ERROR;
        }
        if (Lock_AF_UNIX(unixSocketDir, unixSocketPath) != STATUS_OK)
            return STATUS_ERROR;
        service = unixSocketPath;
    }
    else
    {
        snprintf(portNumberStr, sizeof(portNumberStr), "%d", portNumber);
        service = portNumberStr;
    }
 
    ret = pg_getaddrinfo_all(hostName, service, &hint, &addrs);
    if (ret || !addrs)
    {
        if (hostName)
            ereport(LOG,
                    (errmsg("could not translate host name \"%s\", service \"%s\" to address: %s",
                            hostName, service, gai_strerror(ret))));
        else
            ereport(LOG,
                    (errmsg("could not translate service \"%s\" to address: %s",
                            service, gai_strerror(ret))));
        if (addrs)
            pg_freeaddrinfo_all(hint.ai_family, addrs);
        return STATUS_ERROR;
    }
 
    for (addr = addrs; addr; addr = addr->ai_next)
    {
        if (family != AF_UNIX && addr->ai_family == AF_UNIX)
        {
            /*
             * Only set up a unix domain socket when they really asked for it.
             * The service/port is different in that case.
             */
            continue;
        }
 
        /* See if there is still room to add 1 more socket. */
        for (; listen_index < MaxListen; listen_index++)
        {
            if (ListenSocket[listen_index] == PGINVALID_SOCKET)
                break;
        }
        if (listen_index >= MaxListen)
        {
            ereport(LOG,
                    (errmsg("could not bind to all requested addresses: MAXLISTEN (%d) exceeded",
                            MaxListen)));
            break;
        }
 
        /* set up address family name for log messages */
        switch (addr->ai_family)
        {
            case AF_INET:
                familyDesc = _("IPv4");
                break;
            case AF_INET6:
                familyDesc = _("IPv6");
                break;
            case AF_UNIX:
                familyDesc = _("Unix");
                break;
            default:
                snprintf(familyDescBuf, sizeof(familyDescBuf),
                         _("unrecognized address family %d"),
                         addr->ai_family);
                familyDesc = familyDescBuf;
                break;
        }
 
        /* set up text form of address for log messages */
        if (addr->ai_family == AF_UNIX)
            addrDesc = unixSocketPath;
        else
        {
            pg_getnameinfo_all((const struct sockaddr_storage *) addr->ai_addr,
                               addr->ai_addrlen,
                               addrBuf, sizeof(addrBuf),
                               NULL, 0,
                               NI_NUMERICHOST);
            addrDesc = addrBuf;
        }
 
        if ((fd = socket(addr->ai_family, SOCK_STREAM, 0)) == PGINVALID_SOCKET)
        {
            ereport(LOG,
                    (errcode_for_socket_access(),
            /* translator: first %s is IPv4, IPv6, or Unix */
                     errmsg("could not create %s socket for address \"%s\": %m",
                            familyDesc, addrDesc)));
            continue;
        }
 
#ifndef WIN32
 
        /*
         * Without the SO_REUSEADDR flag, a new postmaster can't be started
         * right away after a stop or crash, giving "address already in use"
         * error on TCP ports.
         *
         * On win32, however, this behavior only happens if the
         * SO_EXCLUSIVEADDRUSE is set. With SO_REUSEADDR, win32 allows
         * multiple servers to listen on the same address, resulting in
         * unpredictable behavior. With no flags at all, win32 behaves as Unix
         * with SO_REUSEADDR.
         */
        if (addr->ai_family != AF_UNIX)
        {
            if ((setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
                            (char *) &one, sizeof(one))) == -1)
            {
                ereport(LOG,
                        (errcode_for_socket_access(),
                /* translator: third %s is IPv4, IPv6, or Unix */
                         errmsg("%s(%s) failed for %s address \"%s\": %m",
                                "setsockopt", "SO_REUSEADDR",
                                familyDesc, addrDesc)));
                closesocket(fd);
                continue;
            }
        }
#endif
 
#ifdef IPV6_V6ONLY
        if (addr->ai_family == AF_INET6)
        {
            if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY,
                           (char *) &one, sizeof(one)) == -1)
            {
                ereport(LOG,
                        (errcode_for_socket_access(),
                /* translator: third %s is IPv4, IPv6, or Unix */
                         errmsg("%s(%s) failed for %s address \"%s\": %m",
                                "setsockopt", "IPV6_V6ONLY",
                                familyDesc, addrDesc)));
                closesocket(fd);
                continue;
            }
        }
#endif
 
        /*
         * Note: This might fail on some OS's, like Linux older than
         * 2.4.21-pre3, that don't have the IPV6_V6ONLY socket option, and map
         * ipv4 addresses to ipv6.  It will show ::ffff:ipv4 for all ipv4
         * connections.
         */
        err = bind(fd, addr->ai_addr, addr->ai_addrlen);
        if (err < 0)
        {
            int         saved_errno = errno;
 
            ereport(LOG,
                    (errcode_for_socket_access(),
            /* translator: first %s is IPv4, IPv6, or Unix */
                     errmsg("could not bind %s address \"%s\": %m",
                            familyDesc, addrDesc),
                     saved_errno == EADDRINUSE ?
                     (addr->ai_family == AF_UNIX ?
                      errhint("Is another postmaster already running on port %d?",
                              (int) portNumber) :
                      errhint("Is another postmaster already running on port %d?"
                              " If not, wait a few seconds and retry.",
                              (int) portNumber)) : 0));
            closesocket(fd);
            continue;
        }
 
        if (addr->ai_family == AF_UNIX)
        {
            if (Setup_AF_UNIX(service) != STATUS_OK)
            {
                closesocket(fd);
                break;
            }
        }
 
        /*
         * Select appropriate accept-queue length limit.  It seems reasonable
         * to use a value similar to the maximum number of child processes
         * that the postmaster will permit.
         */
        maxconn = MaxConnections * 2;
 
        err = listen(fd, maxconn);
        if (err < 0)
        {
            ereport(LOG,
                    (errcode_for_socket_access(),
            /* translator: first %s is IPv4, IPv6, or Unix */
                     errmsg("could not listen on %s address \"%s\": %m",
                            familyDesc, addrDesc)));
            closesocket(fd);
            continue;
        }
 
        if (addr->ai_family == AF_UNIX)
            ereport(LOG,
                    (errmsg("listening on Unix socket \"%s\"",
                            addrDesc)));
        else
            ereport(LOG,
            /* translator: first %s is IPv4 or IPv6 */
                    (errmsg("listening on %s address \"%s\", port %d",
                            familyDesc, addrDesc, (int) portNumber)));
 
        ListenSocket[listen_index] = fd;
        added++;
    }
 
    pg_freeaddrinfo_all(hint.ai_family, addrs);
 
    if (!added)
        return STATUS_ERROR;
 
    return STATUS_OK;
}

References _, bind, closesocket, EADDRINUSE, ereport, err(), errcode_for_socket_access(), errhint(), errmsg(), fd(), listen, ListenSocket, Lock_AF_UNIX(), LOG, MaxConnections, MAXPGPATH, MemSet, pg_freeaddrinfo_all(), pg_getaddrinfo_all(), pg_getnameinfo_all(), PGINVALID_SOCKET, Setup_AF_UNIX(), snprintf, socket, STATUS_ERROR, STATUS_OK, UNIXSOCK_PATH, and UNIXSOCK_PATH_BUFLEN.

Referenced by PostmasterMain().

TouchSocketFiles()

void TouchSocketFiles

(

void

)

Definition at line 847 of file pqcomm.c.

{
    ListCell   *l;
 
    /* Loop through all created sockets... */
    foreach(l, sock_paths)
    {
        char       *sock_path = (char *) lfirst(l);
 
        /* Ignore errors; there's no point in complaining */
        (void) utime(sock_path, NULL);
    }
}

References lfirst, and sock_paths.

Referenced by ServerLoop().

Variable Documentation

FeBeWaitSet

WaitEventSet* FeBeWaitSet

Definition at line 164 of file pqcomm.c.

Referenced by pq_check_connection(), pq_init(), secure_read(), secure_write(), SwitchBackToLocalLatch(), SwitchToSharedLatch(), and WalSndWait().

PqCommBusy

bool PqCommBusy

static

Definition at line 134 of file pqcomm.c.

Referenced by pq_init(), pq_putmessage_v2(), socket_comm_reset(), socket_flush(), socket_flush_if_writable(), and socket_putmessage().

PqCommMethods

const PQcommMethods* PqCommMethods = &PqCommSocketMethods

Definition at line 162 of file pqcomm.c.

Referenced by pq_redirect_to_shm_mq(), and pq_set_parallel_leader().

PqCommReadingMsg

bool PqCommReadingMsg

static

Definition at line 135 of file pqcomm.c.

Referenced by pq_discardbytes(), pq_endmsgread(), pq_getbyte(), pq_getbyte_if_available(), pq_getbytes(), pq_getmessage(), pq_init(), pq_is_reading_msg(), pq_peekbyte(), and pq_startmsgread().

PqCommSocketMethods

const PQcommMethods PqCommSocketMethods

static

Initial value:

= {
    socket_comm_reset,
    socket_flush,
    socket_flush_if_writable,
    socket_is_send_pending,
    socket_putmessage,
    socket_putmessage_noblock
}

Definition at line 153 of file pqcomm.c.

PqRecvBuffer

char PqRecvBuffer[PQ_RECV_BUFFER_SIZE]

static

Definition at line 127 of file pqcomm.c.

Referenced by pq_getbyte(), pq_getbyte_if_available(), pq_getbytes(), pq_peekbyte(), and pq_recvbuf().

PqRecvLength

int PqRecvLength

static

Definition at line 129 of file pqcomm.c.

Referenced by pq_buffer_has_data(), pq_discardbytes(), pq_getbyte(), pq_getbyte_if_available(), pq_getbytes(), pq_init(), pq_peekbyte(), and pq_recvbuf().

PqRecvPointer

int PqRecvPointer

static

Definition at line 128 of file pqcomm.c.

Referenced by pq_buffer_has_data(), pq_discardbytes(), pq_getbyte(), pq_getbyte_if_available(), pq_getbytes(), pq_init(), pq_peekbyte(), and pq_recvbuf().

PqSendBuffer

char* PqSendBuffer

static

Definition at line 122 of file pqcomm.c.

Referenced by internal_flush(), internal_putbytes(), pq_init(), and socket_putmessage_noblock().

PqSendBufferSize

int PqSendBufferSize

static

Definition at line 123 of file pqcomm.c.

Referenced by internal_putbytes(), pq_init(), and socket_putmessage_noblock().

PqSendPointer

int PqSendPointer

static

Definition at line 124 of file pqcomm.c.

Referenced by internal_flush(), internal_putbytes(), pq_init(), socket_flush_if_writable(), socket_is_send_pending(), and socket_putmessage_noblock().

PqSendStart

int PqSendStart

static

Definition at line 125 of file pqcomm.c.

Referenced by internal_flush(), pq_init(), socket_flush_if_writable(), and socket_is_send_pending().

sock_paths

List* sock_paths = NIL

static

Definition at line 110 of file pqcomm.c.

Referenced by Lock_AF_UNIX(), RemoveSocketFiles(), and TouchSocketFiles().

Unix_socket_group

char* Unix_socket_group

Definition at line 107 of file pqcomm.c.

Referenced by Setup_AF_UNIX().

Unix_socket_permissions

int Unix_socket_permissions

Definition at line 106 of file pqcomm.c.

Referenced by Setup_AF_UNIX(), and show_unix_socket_permissions().