connect.c

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/* src/interfaces/ecpg/ecpglib/connect.c */

#define POSTGRES_ECPG_INTERNAL
#include "postgres_fe.h"

#include "ecpg-pthread-win32.h"
#include "ecpgerrno.h"
#include "ecpglib.h"
#include "ecpglib_extern.h"
#include "ecpgtype.h"
#include "sqlca.h"

#ifdef ENABLE_THREAD_SAFETY
static pthread_mutex_t connections_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_key_t actual_connection_key;
static pthread_once_t actual_connection_key_once = PTHREAD_ONCE_INIT;
#endif
static struct connection *actual_connection = NULL;
static struct connection *all_connections = NULL;

#ifdef ENABLE_THREAD_SAFETY
static void
ecpg_actual_connection_init(void)
{
    pthread_key_create(&actual_connection_key, NULL);
}

void
ecpg_pthreads_init(void)
{
    pthread_once(&actual_connection_key_once, ecpg_actual_connection_init);
}
#endif

static struct connection *
ecpg_get_connection_nr(const char *connection_name)
{
    struct connection *ret = NULL;

    if ((connection_name == NULL) || (strcmp(connection_name, "CURRENT") == 0))
    {
#ifdef ENABLE_THREAD_SAFETY
        ret = pthread_getspecific(actual_connection_key);

        /*
         * if no connection in TSD for this thread, get the global default
         * connection and hope the user knows what they're doing (i.e. using
         * their own mutex to protect that connection from concurrent accesses
         */
        /* if !ret then  we  got the connection from TSD */
        if (NULL == ret)
            /* no TSD connection, going for global */
            ret = actual_connection;
#else
        ret = actual_connection;
#endif
    }
    else
    {
        struct connection *con;

        for (con = all_connections; con != NULL; con = con->next)
        {
            if (strcmp(connection_name, con->name) == 0)
                break;
        }
        ret = con;
    }

    return ret;
}

struct connection *
ecpg_get_connection(const char *connection_name)
{
    struct connection *ret = NULL;

    if ((connection_name == NULL) || (strcmp(connection_name, "CURRENT") == 0))
    {
#ifdef ENABLE_THREAD_SAFETY
        ret = pthread_getspecific(actual_connection_key);

        /*
         * if no connection in TSD for this thread, get the global default
         * connection and hope the user knows what they're doing (i.e. using
         * their own mutex to protect that connection from concurrent accesses
         */
        /* if !ret then  we  got the connection from TSD */
        if (NULL == ret)
            /* no TSD connection here either, using global */
            ret = actual_connection;
#else
        ret = actual_connection;
#endif
    }
    else
    {
#ifdef ENABLE_THREAD_SAFETY
        pthread_mutex_lock(&connections_mutex);
#endif

        ret = ecpg_get_connection_nr(connection_name);

#ifdef ENABLE_THREAD_SAFETY
        pthread_mutex_unlock(&connections_mutex);
#endif
    }

    return ret;
}

static void
ecpg_finish(struct connection *act)
{
    if (act != NULL)
    {
        struct ECPGtype_information_cache *cache,
                   *ptr;

        ecpg_deallocate_all_conn(0, ECPG_COMPAT_PGSQL, act);
        PQfinish(act->connection);

        /*
         * no need to lock connections_mutex - we're always called by
         * ECPGdisconnect or ECPGconnect, which are holding the lock
         */

        /* remove act from the list */
        if (act == all_connections)
            all_connections = act->next;
        else
        {
            struct connection *con;

            for (con = all_connections; con->next && con->next != act; con = con->next);
            if (con->next)
                con->next = act->next;
        }

#ifdef ENABLE_THREAD_SAFETY
        if (pthread_getspecific(actual_connection_key) == act)
            pthread_setspecific(actual_connection_key, all_connections);
#endif
        if (actual_connection == act)
            actual_connection = all_connections;

        ecpg_log("ecpg_finish: connection %s closed\n", act->name ? act->name : "(null)");

        for (cache = act->cache_head; cache; ptr = cache, cache = cache->next, ecpg_free(ptr));
        ecpg_free(act->name);
        ecpg_free(act);
        /* delete cursor variables when last connection gets closed */
        if (all_connections == NULL)
        {
            struct var_list *iv_ptr;

            for (; ivlist; iv_ptr = ivlist, ivlist = ivlist->next, ecpg_free(iv_ptr));
        }
    }
    else
        ecpg_log("ecpg_finish: called an extra time\n");
}

bool
ECPGsetcommit(int lineno, const char *mode, const char *connection_name)
{
    struct connection *con = ecpg_get_connection(connection_name);
    PGresult   *results;

    if (!ecpg_init(con, connection_name, lineno))
        return false;

    ecpg_log("ECPGsetcommit on line %d: action \"%s\"; connection \"%s\"\n", lineno, mode, con->name);

    if (con->autocommit && strncmp(mode, "off", strlen("off")) == 0)
    {
        if (PQtransactionStatus(con->connection) == PQTRANS_IDLE)
        {
            results = PQexec(con->connection, "begin transaction");
            if (!ecpg_check_PQresult(results, lineno, con->connection, ECPG_COMPAT_PGSQL))
                return false;
            PQclear(results);
        }
        con->autocommit = false;
    }
    else if (!con->autocommit && strncmp(mode, "on", strlen("on")) == 0)
    {
        if (PQtransactionStatus(con->connection) != PQTRANS_IDLE)
        {
            results = PQexec(con->connection, "commit");
            if (!ecpg_check_PQresult(results, lineno, con->connection, ECPG_COMPAT_PGSQL))
                return false;
            PQclear(results);
        }
        con->autocommit = true;
    }

    return true;
}

bool
ECPGsetconn(int lineno, const char *connection_name)
{
    struct connection *con = ecpg_get_connection(connection_name);

    if (!ecpg_init(con, connection_name, lineno))
        return false;

#ifdef ENABLE_THREAD_SAFETY
    pthread_setspecific(actual_connection_key, con);
#else
    actual_connection = con;
#endif
    return true;
}


static void
ECPGnoticeReceiver(void *arg, const PGresult *result)
{
    char       *sqlstate = PQresultErrorField(result, PG_DIAG_SQLSTATE);
    char       *message = PQresultErrorField(result, PG_DIAG_MESSAGE_PRIMARY);
    struct sqlca_t *sqlca = ECPGget_sqlca();
    int         sqlcode;

    if (sqlca == NULL)
    {
        ecpg_log("out of memory");
        return;
    }

    (void) arg;                 /* keep the compiler quiet */
    if (sqlstate == NULL)
        sqlstate = ECPG_SQLSTATE_ECPG_INTERNAL_ERROR;

    if (message == NULL)        /* Shouldn't happen, but need to be sure */
        message = ecpg_gettext("empty message text");

    /* these are not warnings */
    if (strncmp(sqlstate, "00", 2) == 0)
        return;

    ecpg_log("ECPGnoticeReceiver: %s\n", message);

    /* map to SQLCODE for backward compatibility */
    if (strcmp(sqlstate, ECPG_SQLSTATE_INVALID_CURSOR_NAME) == 0)
        sqlcode = ECPG_WARNING_UNKNOWN_PORTAL;
    else if (strcmp(sqlstate, ECPG_SQLSTATE_ACTIVE_SQL_TRANSACTION) == 0)
        sqlcode = ECPG_WARNING_IN_TRANSACTION;
    else if (strcmp(sqlstate, ECPG_SQLSTATE_NO_ACTIVE_SQL_TRANSACTION) == 0)
        sqlcode = ECPG_WARNING_NO_TRANSACTION;
    else if (strcmp(sqlstate, ECPG_SQLSTATE_DUPLICATE_CURSOR) == 0)
        sqlcode = ECPG_WARNING_PORTAL_EXISTS;
    else
        sqlcode = 0;

    strncpy(sqlca->sqlstate, sqlstate, sizeof(sqlca->sqlstate));
    sqlca->sqlcode = sqlcode;
    sqlca->sqlwarn[2] = 'W';
    sqlca->sqlwarn[0] = 'W';

    strncpy(sqlca->sqlerrm.sqlerrmc, message, sizeof(sqlca->sqlerrm.sqlerrmc));
    sqlca->sqlerrm.sqlerrmc[sizeof(sqlca->sqlerrm.sqlerrmc) - 1] = 0;
    sqlca->sqlerrm.sqlerrml = strlen(sqlca->sqlerrm.sqlerrmc);

    ecpg_log("raising sqlcode %d\n", sqlcode);
}

/* this contains some quick hacks, needs to be cleaned up, but it works */
bool
ECPGconnect(int lineno, int c, const char *name, const char *user, const char *passwd, const char *connection_name, int autocommit)
{
    struct sqlca_t *sqlca = ECPGget_sqlca();
    enum COMPAT_MODE compat = c;
    struct connection *this;
    int         i,
                connect_params = 0;
    char       *dbname = name ? ecpg_strdup(name, lineno) : NULL,
               *host = NULL,
               *tmp,
               *port = NULL,
               *realname = NULL,
               *options = NULL;
    const char **conn_keywords;
    const char **conn_values;

    if (sqlca == NULL)
    {
        ecpg_raise(lineno, ECPG_OUT_OF_MEMORY,
                   ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
        ecpg_free(dbname);
        return false;
    }

    ecpg_init_sqlca(sqlca);

    /*
     * clear auto_mem structure because some error handling functions might
     * access it
     */
    ecpg_clear_auto_mem();

    if (INFORMIX_MODE(compat))
    {
        char       *envname;

        /*
         * Informix uses an environment variable DBPATH that overrides the
         * connection parameters given here. We do the same with PG_DBPATH as
         * the syntax is different.
         */
        envname = getenv("PG_DBPATH");
        if (envname)
        {
            ecpg_free(dbname);
            dbname = ecpg_strdup(envname, lineno);
        }

    }

    if (dbname == NULL && connection_name == NULL)
        connection_name = "DEFAULT";

#if ENABLE_THREAD_SAFETY
    ecpg_pthreads_init();
#endif

    /* check if the identifier is unique */
    if (ecpg_get_connection(connection_name))
    {
        ecpg_free(dbname);
        ecpg_log("ECPGconnect: connection identifier %s is already in use\n",
                 connection_name);
        return false;
    }

    if ((this = (struct connection *) ecpg_alloc(sizeof(struct connection), lineno)) == NULL)
    {
        ecpg_free(dbname);
        return false;
    }

    if (dbname != NULL)
    {
        /* get the detail information from dbname */
        if (strncmp(dbname, "tcp:", 4) == 0 || strncmp(dbname, "unix:", 5) == 0)
        {
            int         offset = 0;

            /*
             * only allow protocols tcp and unix
             */
            if (strncmp(dbname, "tcp:", 4) == 0)
                offset = 4;
            else if (strncmp(dbname, "unix:", 5) == 0)
                offset = 5;

            if (strncmp(dbname + offset, "postgresql://", strlen("postgresql://")) == 0)
            {

                /*------
                 * new style:
                 *  <tcp|unix>:postgresql://server[:port][/db-name][?options]
                 *------
                 */
                offset += strlen("postgresql://");

                tmp = strrchr(dbname + offset, '?');
                if (tmp != NULL)    /* options given */
                {
                    options = ecpg_strdup(tmp + 1, lineno);
                    *tmp = '\0';
                }

                tmp = last_dir_separator(dbname + offset);
                if (tmp != NULL)    /* database name given */
                {
                    if (tmp[1] != '\0') /* non-empty database name */
                    {
                        realname = ecpg_strdup(tmp + 1, lineno);
                        connect_params++;
                    }
                    *tmp = '\0';
                }

                tmp = strrchr(dbname + offset, ':');
                if (tmp != NULL)    /* port number given */
                {
                    *tmp = '\0';
                    port = ecpg_strdup(tmp + 1, lineno);
                    connect_params++;
                }

                if (strncmp(dbname, "unix:", 5) == 0)
                {
                    /*
                     * The alternative of using "127.0.0.1" here is deprecated
                     * and undocumented; we'll keep it for backward
                     * compatibility's sake, but not extend it to allow IPv6.
                     */
                    if (strcmp(dbname + offset, "localhost") != 0 &&
                        strcmp(dbname + offset, "127.0.0.1") != 0)
                    {
                        ecpg_log("ECPGconnect: non-localhost access via sockets on line %d\n", lineno);
                        ecpg_raise(lineno, ECPG_CONNECT, ECPG_SQLSTATE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION, realname ? realname : ecpg_gettext("<DEFAULT>"));
                        if (host)
                            ecpg_free(host);
                        if (port)
                            ecpg_free(port);
                        if (options)
                            ecpg_free(options);
                        if (realname)
                            ecpg_free(realname);
                        if (dbname)
                            ecpg_free(dbname);
                        free(this);
                        return false;
                    }
                }
                else
                {
                    if (*(dbname + offset) != '\0')
                    {
                        host = ecpg_strdup(dbname + offset, lineno);
                        connect_params++;
                    }
                }
            }
        }
        else
        {
            /* old style: dbname[@server][:port] */
            tmp = strrchr(dbname, ':');
            if (tmp != NULL)    /* port number given */
            {
                port = ecpg_strdup(tmp + 1, lineno);
                connect_params++;
                *tmp = '\0';
            }

            tmp = strrchr(dbname, '@');
            if (tmp != NULL)    /* host name given */
            {
                host = ecpg_strdup(tmp + 1, lineno);
                connect_params++;
                *tmp = '\0';
            }

            if (strlen(dbname) > 0)
            {
                realname = ecpg_strdup(dbname, lineno);
                connect_params++;
            }
            else
                realname = NULL;
        }
    }
    else
        realname = NULL;

    /*
     * Count options for the allocation done below (this may produce an
     * overestimate, it's ok).
     */
    if (options)
        for (i = 0; options[i]; i++)
            if (options[i] == '=')
                connect_params++;

    if (user && strlen(user) > 0)
        connect_params++;
    if (passwd && strlen(passwd) > 0)
        connect_params++;

    /*
     * Allocate enough space for all connection parameters.  These allocations
     * are done before manipulating the list of connections to ease the error
     * handling on failure.
     */
    conn_keywords = (const char **) ecpg_alloc((connect_params + 1) * sizeof(char *), lineno);
    conn_values = (const char **) ecpg_alloc(connect_params * sizeof(char *), lineno);
    if (conn_keywords == NULL || conn_values == NULL)
    {
        if (host)
            ecpg_free(host);
        if (port)
            ecpg_free(port);
        if (options)
            ecpg_free(options);
        if (realname)
            ecpg_free(realname);
        if (dbname)
            ecpg_free(dbname);
        if (conn_keywords)
            ecpg_free(conn_keywords);
        if (conn_values)
            ecpg_free(conn_values);
        free(this);
        return false;
    }

    /* add connection to our list */
#ifdef ENABLE_THREAD_SAFETY
    pthread_mutex_lock(&connections_mutex);
#endif
    if (connection_name != NULL)
        this->name = ecpg_strdup(connection_name, lineno);
    else
        this->name = ecpg_strdup(realname, lineno);

    this->cache_head = NULL;
    this->prep_stmts = NULL;

    if (all_connections == NULL)
        this->next = NULL;
    else
        this->next = all_connections;

    all_connections = this;
#ifdef ENABLE_THREAD_SAFETY
    pthread_setspecific(actual_connection_key, all_connections);
#endif
    actual_connection = all_connections;

    ecpg_log("ECPGconnect: opening database %s on %s port %s %s%s %s%s\n",
             realname ? realname : "<DEFAULT>",
             host ? host : "<DEFAULT>",
             port ? (ecpg_internal_regression_mode ? "<REGRESSION_PORT>" : port) : "<DEFAULT>",
             options ? "with options " : "", options ? options : "",
             (user && strlen(user) > 0) ? "for user " : "", user ? user : "");

    i = 0;
    if (realname)
    {
        conn_keywords[i] = "dbname";
        conn_values[i] = realname;
        i++;
    }
    if (host)
    {
        conn_keywords[i] = "host";
        conn_values[i] = host;
        i++;
    }
    if (port)
    {
        conn_keywords[i] = "port";
        conn_values[i] = port;
        i++;
    }
    if (user && strlen(user) > 0)
    {
        conn_keywords[i] = "user";
        conn_values[i] = user;
        i++;
    }
    if (passwd && strlen(passwd) > 0)
    {
        conn_keywords[i] = "password";
        conn_values[i] = passwd;
        i++;
    }
    if (options)
    {
        char       *str;

        /*
         * The options string contains "keyword=value" pairs separated by
         * '&'s.  We must break this up into keywords and values to pass to
         * libpq (it's okay to scribble on the options string).  We ignore
         * spaces just before each keyword or value.
         */
        for (str = options; *str;)
        {
            int         e,
                        a;
            char       *token1,
                       *token2;

            /* Skip spaces before keyword */
            for (token1 = str; *token1 == ' '; token1++)
                 /* skip */ ;
            /* Find end of keyword */
            for (e = 0; token1[e] && token1[e] != '='; e++)
                 /* skip */ ;
            if (token1[e])      /* found "=" */
            {
                token1[e] = '\0';
                /* Skip spaces before value */
                for (token2 = token1 + e + 1; *token2 == ' '; token2++)
                     /* skip */ ;
                /* Find end of value */
                for (a = 0; token2[a] && token2[a] != '&'; a++)
                     /* skip */ ;
                if (token2[a])  /* found "&" => another option follows */
                {
                    token2[a] = '\0';
                    str = token2 + a + 1;
                }
                else
                    str = token2 + a;

                conn_keywords[i] = token1;
                conn_values[i] = token2;
                i++;
            }
            else
            {
                /* Bogus options syntax ... ignore trailing garbage */
                str = token1 + e;
            }
        }
    }

    Assert(i <= connect_params);
    conn_keywords[i] = NULL;    /* terminator */

    this->connection = PQconnectdbParams(conn_keywords, conn_values, 0);

    if (host)
        ecpg_free(host);
    if (port)
        ecpg_free(port);
    if (options)
        ecpg_free(options);
    if (dbname)
        ecpg_free(dbname);
    ecpg_free(conn_values);
    ecpg_free(conn_keywords);

    if (PQstatus(this->connection) == CONNECTION_BAD)
    {
        const char *errmsg = PQerrorMessage(this->connection);
        const char *db = realname ? realname : ecpg_gettext("<DEFAULT>");

        /* PQerrorMessage's result already has a trailing newline */
        ecpg_log("ECPGconnect: %s", errmsg);

        ecpg_finish(this);
#ifdef ENABLE_THREAD_SAFETY
        pthread_mutex_unlock(&connections_mutex);
#endif

        ecpg_raise(lineno, ECPG_CONNECT, ECPG_SQLSTATE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION, db);
        if (realname)
            ecpg_free(realname);

        return false;
    }

    if (realname)
        ecpg_free(realname);

#ifdef ENABLE_THREAD_SAFETY
    pthread_mutex_unlock(&connections_mutex);
#endif

    this->autocommit = autocommit;

    PQsetNoticeReceiver(this->connection, &ECPGnoticeReceiver, (void *) this);

    return true;
}

bool
ECPGdisconnect(int lineno, const char *connection_name)
{
    struct sqlca_t *sqlca = ECPGget_sqlca();
    struct connection *con;

    if (sqlca == NULL)
    {
        ecpg_raise(lineno, ECPG_OUT_OF_MEMORY,
                   ECPG_SQLSTATE_ECPG_OUT_OF_MEMORY, NULL);
        return false;
    }

#ifdef ENABLE_THREAD_SAFETY
    pthread_mutex_lock(&connections_mutex);
#endif

    if (strcmp(connection_name, "ALL") == 0)
    {
        ecpg_init_sqlca(sqlca);
        for (con = all_connections; con;)
        {
            struct connection *f = con;

            con = con->next;
            ecpg_finish(f);
        }
    }
    else
    {
        con = ecpg_get_connection_nr(connection_name);

        if (!ecpg_init(con, connection_name, lineno))
        {
#ifdef ENABLE_THREAD_SAFETY
            pthread_mutex_unlock(&connections_mutex);
#endif
            return false;
        }
        else
            ecpg_finish(con);
    }

#ifdef ENABLE_THREAD_SAFETY
    pthread_mutex_unlock(&connections_mutex);
#endif

    return true;
}

PGconn *
ECPGget_PGconn(const char *connection_name)
{
    struct connection *con;

    con = ecpg_get_connection(connection_name);
    if (con == NULL)
        return NULL;

    return con->connection;
}