pgsql.c

/*
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | Authors: Zeev Suraski <zeev@php.net>                                 |
   |          Jouni Ahto <jouni.ahto@exdec.fi>                            |
   |          Yasuo Ohgaki <yohgaki@php.net>                              |
   |          Youichi Iwakiri <yiwakiri@st.rim.or.jp> (pg_copy_*)         |
   |          Chris Kings-Lynne <chriskl@php.net> (v3 protocol)           |
   +----------------------------------------------------------------------+
 */

#include <stdlib.h>

#define PHP_PGSQL_PRIVATE 1

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#define SMART_STR_PREALLOC 512

#include "php.h"
#include "php_ini.h"
#include "ext/standard/php_standard.h"
#include "zend_smart_str.h"
#include "ext/pcre/php_pcre.h"
#ifdef PHP_WIN32
# include "win32/time.h"
#endif
#include "php_pgsql.h"
#include "php_globals.h"
#include "zend_exceptions.h"

#ifdef HAVE_PGSQL

#ifndef InvalidOid
#define InvalidOid ((Oid) 0)
#endif

#define PGSQL_ASSOC           1<<0
#define PGSQL_NUM             1<<1
#define PGSQL_BOTH            (PGSQL_ASSOC|PGSQL_NUM)

#define PGSQL_NOTICE_LAST     1  /* Get the last notice */
#define PGSQL_NOTICE_ALL      2  /* Get all notices */
#define PGSQL_NOTICE_CLEAR    3  /* Remove notices */

#define PGSQL_STATUS_LONG     1
#define PGSQL_STATUS_STRING   2

#define PGSQL_MAX_LENGTH_OF_LONG   30
#define PGSQL_MAX_LENGTH_OF_DOUBLE 60

char pgsql_libpq_version[16];

#include "pgsql_arginfo.h"

#if ZEND_LONG_MAX < UINT_MAX
#define PGSQL_RETURN_OID(oid) do { \
	if (oid > ZEND_LONG_MAX) { \
		RETURN_STR(zend_ulong_to_str(oid)); \
	} \
	RETURN_LONG((zend_long)oid); \
} while(0)
#else
#define PGSQL_RETURN_OID(oid) RETURN_LONG((zend_long)oid)
#endif

#define CHECK_DEFAULT_LINK(x) \
	if ((x) == NULL) { \
		zend_throw_error(NULL, "No PostgreSQL connection opened yet"); \
		RETURN_THROWS(); \
	}

/* This is a bit hacky as the macro usage is "link = FETCH_DEFAULT_LINK();" */
#define FETCH_DEFAULT_LINK() \
		(PGG(default_link) ? pgsql_link_from_obj(PGG(default_link)) : NULL); \
		php_error_docref(NULL, E_DEPRECATED, "Automatic fetching of PostgreSQL connection is deprecated")

/* Used only when creating a connection */
#define FETCH_DEFAULT_LINK_NO_WARNING() \
		(PGG(default_link) ? pgsql_link_from_obj(PGG(default_link)) : NULL)

#define CHECK_PGSQL_LINK(link_handle) \
	if (link_handle->conn == NULL) { \
		zend_throw_error(NULL, "PostgreSQL connection has already been closed"); \
		RETURN_THROWS(); \
	}

#define CHECK_PGSQL_RESULT(result_handle) \
	if (result_handle->result == NULL) { \
		zend_throw_error(NULL, "PostgreSQL result has already been closed"); \
		RETURN_THROWS(); \
	}

#define CHECK_PGSQL_LOB(lob) \
	if (lob->conn == NULL) { \
		zend_throw_error(NULL, "PostgreSQL large object has already been closed"); \
		RETURN_THROWS(); \
	}

#ifndef HAVE_PQFREEMEM
#define PQfreemem free
#endif

ZEND_DECLARE_MODULE_GLOBALS(pgsql)
static PHP_GINIT_FUNCTION(pgsql);

/* {{{ pgsql_module_entry */
zend_module_entry pgsql_module_entry = {
	STANDARD_MODULE_HEADER,
	"pgsql",
	ext_functions,
	PHP_MINIT(pgsql),
	PHP_MSHUTDOWN(pgsql),
	PHP_RINIT(pgsql),
	PHP_RSHUTDOWN(pgsql),
	PHP_MINFO(pgsql),
	PHP_PGSQL_VERSION,
	PHP_MODULE_GLOBALS(pgsql),
	PHP_GINIT(pgsql),
	NULL,
	NULL,
	STANDARD_MODULE_PROPERTIES_EX
};
/* }}} */

#ifdef COMPILE_DL_PGSQL
#ifdef ZTS
ZEND_TSRMLS_CACHE_DEFINE()
#endif
ZEND_GET_MODULE(pgsql)
#endif

static int le_plink;

static zend_class_entry *pgsql_link_ce, *pgsql_result_ce, *pgsql_lob_ce;
static zend_object_handlers pgsql_link_object_handlers, pgsql_result_object_handlers, pgsql_lob_object_handlers;

static inline pgsql_link_handle *pgsql_link_from_obj(zend_object *obj) {
	return (pgsql_link_handle *)((char *)(obj) - XtOffsetOf(pgsql_link_handle, std));
}

#define Z_PGSQL_LINK_P(zv) pgsql_link_from_obj(Z_OBJ_P(zv))

static zend_object *pgsql_link_create_object(zend_class_entry *class_type) {
	pgsql_link_handle *intern = zend_object_alloc(sizeof(pgsql_link_handle), class_type);

	zend_object_std_init(&intern->std, class_type);
	object_properties_init(&intern->std, class_type);
	intern->std.handlers = &pgsql_link_object_handlers;

	return &intern->std;
}

static zend_function *pgsql_link_get_constructor(zend_object *object) {
	zend_throw_error(NULL, "Cannot directly construct PgSql\\Connection, use pg_connect() or pg_pconnect() instead");
	return NULL;
}

static void pgsql_link_free(pgsql_link_handle *link)
{
	PGresult *res;

	while ((res = PQgetResult(link->conn))) {
		PQclear(res);
	}
	if (!link->persistent) {
		PQuntrace(link->conn);
		PQfinish(link->conn);
	}
	PGG(num_links)--;

	zend_hash_del(&PGG(connections), link->hash);

	link->conn = NULL;
	zend_string_release(link->hash);

	if (link->notices) {
		zend_hash_destroy(link->notices);
		FREE_HASHTABLE(link->notices);
		link->notices = NULL;
	}
}

static void pgsql_link_free_obj(zend_object *obj)
{
	pgsql_link_handle *link = pgsql_link_from_obj(obj);

	if (link->conn) {
		pgsql_link_free(link);
	}

	zend_object_std_dtor(&link->std);
}

static inline pgsql_result_handle *pgsql_result_from_obj(zend_object *obj) {
	return (pgsql_result_handle *)((char *)(obj) - XtOffsetOf(pgsql_result_handle, std));
}

#define Z_PGSQL_RESULT_P(zv) pgsql_result_from_obj(Z_OBJ_P(zv))

static zend_object *pgsql_result_create_object(zend_class_entry *class_type) {
	pgsql_result_handle *intern = zend_object_alloc(sizeof(pgsql_result_handle), class_type);

	zend_object_std_init(&intern->std, class_type);
	object_properties_init(&intern->std, class_type);
	intern->std.handlers = &pgsql_result_object_handlers;

	return &intern->std;
}

static zend_function *pgsql_result_get_constructor(zend_object *object) {
	zend_throw_error(NULL, "Cannot directly construct PgSql\\Result, use a dedicated function instead");
	return NULL;
}

static void pgsql_result_free(pgsql_result_handle *pg_result)
{
	PQclear(pg_result->result);
	pg_result->result = NULL;
}

static void pgsql_result_free_obj(zend_object *obj)
{
	pgsql_result_handle *pg_result = pgsql_result_from_obj(obj);

	if (pg_result->result) {
		pgsql_result_free(pg_result);
	}

	zend_object_std_dtor(&pg_result->std);
}

static inline pgLofp *pgsql_lob_from_obj(zend_object *obj) {
	return (pgLofp *)((char *)(obj) - XtOffsetOf(pgLofp, std));
}

#define Z_PGSQL_LOB_P(zv) pgsql_lob_from_obj(Z_OBJ_P(zv))

static zend_object *pgsql_lob_create_object(zend_class_entry *class_type) {
	pgLofp *intern = zend_object_alloc(sizeof(pgLofp), class_type);

	zend_object_std_init(&intern->std, class_type);
	object_properties_init(&intern->std, class_type);
	intern->std.handlers = &pgsql_lob_object_handlers;

	return &intern->std;
}

static zend_function *pgsql_lob_get_constructor(zend_object *object) {
	zend_throw_error(NULL, "Cannot directly construct PgSql\\Lob, use pg_lo_open() instead");
	return NULL;
}

static void pgsql_lob_free_obj(zend_object *obj)
{
	pgLofp *lofp = pgsql_lob_from_obj(obj);

	zend_object_std_dtor(&lofp->std);
}

/* Compatibility definitions */

#ifndef HAVE_PGSQL_WITH_MULTIBYTE_SUPPORT
#define pg_encoding_to_char(x) "SQL_ASCII"
#endif

static zend_string *_php_pgsql_trim_message(const char *message)
{
	size_t i = strlen(message);

	if (i>2 && (message[i-2] == '\r' || message[i-2] == '\n') && message[i-1] == '.') {
		--i;
	}
	while (i>1 && (message[i-1] == '\r' || message[i-1] == '\n')) {
		--i;
	}
	return zend_string_init(message, i, 0);
}

#define PHP_PQ_ERROR(text, pgsql) { \
		zend_string *msgbuf = _php_pgsql_trim_message(PQerrorMessage(pgsql)); \
		php_error_docref(NULL, E_WARNING, text, ZSTR_VAL(msgbuf)); \
		zend_string_release(msgbuf); \
} \

static void php_pgsql_set_default_link(zend_object *obj)
{
	GC_ADDREF(obj);

	if (PGG(default_link) != NULL) {
		zend_object_release(PGG(default_link));
	}

	PGG(default_link) = obj;
}

static void _close_pgsql_plink(zend_resource *rsrc)
{
	PGconn *link = (PGconn *)rsrc->ptr;
	PGresult *res;

	while ((res = PQgetResult(link))) {
		PQclear(res);
	}
	PQfinish(link);
	/* See https://github.com/php/php-src/issues/12974 why we need to check the if */
#ifdef ZTS
	if (pgsql_module_entry.module_started)
#endif
	{
		PGG(num_persistent)--;
		PGG(num_links)--;
	}
	rsrc->ptr = NULL;
}

static void _php_pgsql_notice_handler(void *l, const char *message)
{
	if (PGG(ignore_notices)) {
		return;
	}

	zval tmp;
	pgsql_link_handle *link = (pgsql_link_handle *) l;

	if (!link->notices) {
		link->notices = zend_new_array(1);
	}

	zend_string *trimmed_message = _php_pgsql_trim_message(message);
	if (PGG(log_notices)) {
		php_error_docref(NULL, E_NOTICE, "%s", ZSTR_VAL(trimmed_message));
	}

	ZVAL_STR(&tmp, trimmed_message);
	zend_hash_next_index_insert(link->notices, &tmp);
}

static int _rollback_transactions(zval *el)
{
	PGconn *link;
	PGresult *res;
	zend_resource *rsrc = Z_RES_P(el);

	if (rsrc->type != le_plink) {
		return ZEND_HASH_APPLY_KEEP;
	}

	link = (PGconn *) rsrc->ptr;

	if (PQsetnonblocking(link, 0)) {
		php_error_docref("ref.pgsql", E_NOTICE, "Cannot set connection to blocking mode");
		return -1;
	}

	while ((res = PQgetResult(link))) {
		PQclear(res);
	}
	if ((PQprotocolVersion(link) >= 3 && PQtransactionStatus(link) != PQTRANS_IDLE) || PQprotocolVersion(link) < 3) {
		int orig = PGG(ignore_notices);
		PGG(ignore_notices) = 1;
		res = PQexec(link,"ROLLBACK;");
		PQclear(res);
		PGG(ignore_notices) = orig;
	}

	return ZEND_HASH_APPLY_KEEP;
}

static void release_string(zval *zv)
{
	zend_string_release((zend_string *) Z_PTR_P(zv));
}

static bool _php_pgsql_identifier_is_escaped(const char *identifier, size_t len) /* {{{ */
{
	/* Handle edge case. Cannot be a escaped string */
	if (len <= 2) {
		return false;
	}
	/* Detect double quotes */
	if (identifier[0] == '"' && identifier[len-1] == '"') {
		size_t i;

		/* Detect wrong format of " inside of escaped string */
		for (i = 1; i < len-1; i++) {
			if (identifier[i] == '"' && (identifier[++i] != '"' || i == len-1)) {
				return false;
			}
		}
	} else {
		return false;
	}
	/* Escaped properly */
	return true;
}

/* {{{ PHP_INI */
PHP_INI_BEGIN()
STD_PHP_INI_BOOLEAN( "pgsql.allow_persistent",      "1",  PHP_INI_SYSTEM, OnUpdateBool, allow_persistent,      zend_pgsql_globals, pgsql_globals)
STD_PHP_INI_ENTRY_EX("pgsql.max_persistent",       "-1",  PHP_INI_SYSTEM, OnUpdateLong, max_persistent,        zend_pgsql_globals, pgsql_globals, display_link_numbers)
STD_PHP_INI_ENTRY_EX("pgsql.max_links",            "-1",  PHP_INI_SYSTEM, OnUpdateLong, max_links,             zend_pgsql_globals, pgsql_globals, display_link_numbers)
STD_PHP_INI_BOOLEAN( "pgsql.auto_reset_persistent", "0",  PHP_INI_SYSTEM, OnUpdateLong, auto_reset_persistent, zend_pgsql_globals, pgsql_globals)
STD_PHP_INI_BOOLEAN( "pgsql.ignore_notice",         "0",  PHP_INI_ALL,    OnUpdateBool, ignore_notices,        zend_pgsql_globals, pgsql_globals)
STD_PHP_INI_BOOLEAN( "pgsql.log_notice",            "0",  PHP_INI_ALL,    OnUpdateBool, log_notices,           zend_pgsql_globals, pgsql_globals)
PHP_INI_END()

static PHP_GINIT_FUNCTION(pgsql)
{
#if defined(COMPILE_DL_PGSQL) && defined(ZTS)
	ZEND_TSRMLS_CACHE_UPDATE();
#endif
	memset(pgsql_globals, 0, sizeof(zend_pgsql_globals));
	zend_hash_init(&pgsql_globals->connections, 0, NULL, NULL, 1);
}

static void php_libpq_version(char *buf, size_t len)
{
	int version = PQlibVersion();
	int major = version / 10000;
	if (major >= 10) {
		int minor = version % 10000;
		snprintf(buf, len, "%d.%d", major, minor);
	} else {
		int minor = version / 100 % 100;
		int revision = version % 100;
		snprintf(buf, len, "%d.%d.%d", major, minor, revision);
	}
}

PHP_MINIT_FUNCTION(pgsql)
{
	REGISTER_INI_ENTRIES();

	le_plink = zend_register_list_destructors_ex(NULL, _close_pgsql_plink, "pgsql link persistent", module_number);

	pgsql_link_ce = register_class_PgSql_Connection();
	pgsql_link_ce->create_object = pgsql_link_create_object;

	memcpy(&pgsql_link_object_handlers, &std_object_handlers, sizeof(zend_object_handlers));
	pgsql_link_object_handlers.offset = XtOffsetOf(pgsql_link_handle, std);
	pgsql_link_object_handlers.free_obj = pgsql_link_free_obj;
	pgsql_link_object_handlers.get_constructor = pgsql_link_get_constructor;
	pgsql_link_object_handlers.clone_obj = NULL;
	pgsql_link_object_handlers.compare = zend_objects_not_comparable;

	pgsql_result_ce = register_class_PgSql_Result();
	pgsql_result_ce->create_object = pgsql_result_create_object;

	memcpy(&pgsql_result_object_handlers, &std_object_handlers, sizeof(zend_object_handlers));
	pgsql_result_object_handlers.offset = XtOffsetOf(pgsql_result_handle, std);
	pgsql_result_object_handlers.free_obj = pgsql_result_free_obj;
	pgsql_result_object_handlers.get_constructor = pgsql_result_get_constructor;
	pgsql_result_object_handlers.clone_obj = NULL;
	pgsql_result_object_handlers.compare = zend_objects_not_comparable;

	pgsql_lob_ce = register_class_PgSql_Lob();
	pgsql_lob_ce->create_object = pgsql_lob_create_object;

	memcpy(&pgsql_lob_object_handlers, &std_object_handlers, sizeof(zend_object_handlers));
	pgsql_lob_object_handlers.offset = XtOffsetOf(pgLofp, std);
	pgsql_lob_object_handlers.free_obj = pgsql_lob_free_obj;
	pgsql_lob_object_handlers.get_constructor = pgsql_lob_get_constructor;
	pgsql_lob_object_handlers.clone_obj = NULL;
	pgsql_lob_object_handlers.compare = zend_objects_not_comparable;

	/* libpq version */
	php_libpq_version(pgsql_libpq_version, sizeof(pgsql_libpq_version));

	register_pgsql_symbols(module_number);

	return SUCCESS;
}

PHP_MSHUTDOWN_FUNCTION(pgsql)
{
	UNREGISTER_INI_ENTRIES();
	zend_hash_destroy(&PGG(connections));

	return SUCCESS;
}

PHP_RINIT_FUNCTION(pgsql)
{
	PGG(default_link) = NULL;
	PGG(num_links) = PGG(num_persistent);
	zend_hash_init(&PGG(field_oids), 0, NULL, release_string, 0);
	zend_hash_init(&PGG(table_oids), 0, NULL, release_string, 0);
	return SUCCESS;
}

PHP_RSHUTDOWN_FUNCTION(pgsql)
{
	if (PGG(default_link)) {
		zend_object_release(PGG(default_link));
		PGG(default_link) = NULL;
	}

	zend_hash_destroy(&PGG(field_oids));
	zend_hash_destroy(&PGG(table_oids));
	/* clean up persistent connection */
	zend_hash_apply(&EG(persistent_list), (apply_func_t) _rollback_transactions);
	return SUCCESS;
}

PHP_MINFO_FUNCTION(pgsql)
{
	char buf[256];

	php_info_print_table_start();
	php_info_print_table_header(2, "PostgreSQL Support", "enabled");
	php_info_print_table_row(2, "PostgreSQL (libpq) Version", pgsql_libpq_version);
#ifdef HAVE_PGSQL_WITH_MULTIBYTE_SUPPORT
	php_info_print_table_row(2, "Multibyte character support", "enabled");
#else
	php_info_print_table_row(2, "Multibyte character support", "disabled");
#endif
	snprintf(buf, sizeof(buf), ZEND_LONG_FMT, PGG(num_persistent));
	php_info_print_table_row(2, "Active Persistent Links", buf);
	snprintf(buf, sizeof(buf), ZEND_LONG_FMT, PGG(num_links));
	php_info_print_table_row(2, "Active Links", buf);
	php_info_print_table_end();

	DISPLAY_INI_ENTRIES();
}

static void php_pgsql_do_connect(INTERNAL_FUNCTION_PARAMETERS, int persistent)
{
	char *connstring;
	size_t connstring_len;
	pgsql_link_handle *link;
	PGconn *pgsql;
	smart_str str = {0};
	zend_long connect_type = 0;
	PGresult *pg_result;

	if (zend_parse_parameters(ZEND_NUM_ARGS(), "s|l", &connstring, &connstring_len, &connect_type) == FAILURE) {
		RETURN_THROWS();
	}

	smart_str_appends(&str, "pgsql");
	smart_str_appendl(&str, connstring, connstring_len);
	smart_str_appendc(&str, '_');
	/* make sure that the PGSQL_CONNECT_FORCE_NEW bit is not part of the hash so that subsequent
	 * connections can re-use this connection. See bug #39979. */
	smart_str_append_long(&str, connect_type & ~PGSQL_CONNECT_FORCE_NEW);
	smart_str_0(&str);

	if (persistent && PGG(allow_persistent)) {
		zend_resource *le;

		/* try to find if we already have this link in our persistent list */
		if ((le = zend_hash_find_ptr(&EG(persistent_list), str.s)) == NULL) {  /* we don't */
			if (PGG(max_links) != -1 && PGG(num_links) >= PGG(max_links)) {
				php_error_docref(NULL, E_WARNING,
								 "Cannot create new link. Too many open links (" ZEND_LONG_FMT ")", PGG(num_links));
				goto err;
			}
			if (PGG(max_persistent) != -1 && PGG(num_persistent) >= PGG(max_persistent)) {
				php_error_docref(NULL, E_WARNING,
								 "Cannot create new link. Too many open persistent links (" ZEND_LONG_FMT ")", PGG(num_persistent));
				goto err;
			}

			/* create the link */
			pgsql = PQconnectdb(connstring);
			if (pgsql == NULL || PQstatus(pgsql) == CONNECTION_BAD) {
				PHP_PQ_ERROR("Unable to connect to PostgreSQL server: %s", pgsql)
				if (pgsql) {
					PQfinish(pgsql);
				}
				goto err;
			}

			/* hash it up */
			if (zend_register_persistent_resource(ZSTR_VAL(str.s), ZSTR_LEN(str.s), pgsql, le_plink) == NULL) {
				goto err;
			}
			PGG(num_links)++;
			PGG(num_persistent)++;
		} else {  /* we do */
			if (le->type != le_plink) {
				goto err;
			}
			/* ensure that the link did not die */
			if (PGG(auto_reset_persistent) & 1) {
				/* need to send & get something from backend to
				   make sure we catch CONNECTION_BAD every time */
				PGresult *pg_result;
				pg_result = PQexec(le->ptr, "select 1");
				PQclear(pg_result);
			}
			if (PQstatus(le->ptr) == CONNECTION_BAD) { /* the link died */
				if (le->ptr == NULL) {
					le->ptr = PQconnectdb(connstring);
				}
				else {
					PQreset(le->ptr);
				}
				if (le->ptr == NULL || PQstatus(le->ptr) == CONNECTION_BAD) {
					php_error_docref(NULL, E_WARNING,"PostgreSQL connection lost, unable to reconnect");
					zend_hash_del(&EG(persistent_list), str.s);
					goto err;
				}
			}
			pgsql = (PGconn *) le->ptr;
			/* consider to use php_version_compare() here */
			if (PQprotocolVersion(pgsql) >= 3 && zend_strtod(PQparameterStatus(pgsql, "server_version"), NULL) >= 7.2) {
				pg_result = PQexec(pgsql, "RESET ALL;");
				PQclear(pg_result);
			}
		}

		object_init_ex(return_value, pgsql_link_ce);
		link = Z_PGSQL_LINK_P(return_value);
		link->conn = pgsql;
		link->hash = zend_string_copy(str.s);
		link->notices = NULL;
		link->persistent = 1;
	} else { /* Non persistent connection */
		zval *index_ptr;

		/* first we check the hash for the hashed_details key. If it exists,
		 * it should point us to the right offset where the actual pgsql link sits.
		 * if it doesn't, open a new pgsql link, add it to the resource list,
		 * and add a pointer to it with hashed_details as the key.
		 */
		if (!(connect_type & PGSQL_CONNECT_FORCE_NEW)
			&& (index_ptr = zend_hash_find(&PGG(connections), str.s)) != NULL) {
			php_pgsql_set_default_link(Z_OBJ_P(index_ptr));
			ZVAL_COPY(return_value, index_ptr);

			goto cleanup;
		}
		if (PGG(max_links) != -1 && PGG(num_links) >= PGG(max_links)) {
			php_error_docref(NULL, E_WARNING, "Cannot create new link. Too many open links (" ZEND_LONG_FMT ")", PGG(num_links));
			goto err;
		}

		/* Non-blocking connect */
		if (connect_type & PGSQL_CONNECT_ASYNC) {
			pgsql = PQconnectStart(connstring);
			if (pgsql==NULL || PQstatus(pgsql)==CONNECTION_BAD) {
				PHP_PQ_ERROR("Unable to connect to PostgreSQL server: %s", pgsql);
				if (pgsql) {
					PQfinish(pgsql);
				}
				goto err;
			}
		} else {
			pgsql = PQconnectdb(connstring);
			if (pgsql==NULL || PQstatus(pgsql)==CONNECTION_BAD) {
				PHP_PQ_ERROR("Unable to connect to PostgreSQL server: %s", pgsql);
				if (pgsql) {
					PQfinish(pgsql);
				}
				goto err;
			}
		}

		object_init_ex(return_value, pgsql_link_ce);
		link = Z_PGSQL_LINK_P(return_value);
		link->conn = pgsql;
		link->hash = zend_string_copy(str.s);
		link->notices = NULL;
		link->persistent = 0;

		/* add it to the hash */
		zend_hash_update(&PGG(connections), str.s, return_value);

		/* Keep track of link => hash mapping, so we can remove the hash entry from connections
		 * when the connection is closed. This uses the address of the connection rather than the
		 * zend_resource, because the resource destructor is passed a stack copy of the resource
		 * structure. */

		PGG(num_links)++;
	}
	/* set notice processor */
	if (! PGG(ignore_notices) && Z_TYPE_P(return_value) == IS_OBJECT) {
		PQsetNoticeProcessor(pgsql, _php_pgsql_notice_handler, link);
	}
	php_pgsql_set_default_link(Z_OBJ_P(return_value));

cleanup:
	smart_str_free(&str);
	return;

err:
	smart_str_free(&str);
	RETURN_FALSE;
}
/* }}} */

/* {{{ Open a PostgreSQL connection */
PHP_FUNCTION(pg_connect)
{
	php_pgsql_do_connect(INTERNAL_FUNCTION_PARAM_PASSTHRU,0);
}
/* }}} */

/* {{{ Poll the status of an in-progress async PostgreSQL connection attempt*/
PHP_FUNCTION(pg_connect_poll)
{
	zval *pgsql_link;
	pgsql_link_handle *pgsql_handle;
	PGconn *pgsql;
	int ret;

	if (zend_parse_parameters(ZEND_NUM_ARGS(), "O", &pgsql_link, pgsql_link_ce) == FAILURE) {
		RETURN_THROWS();
	}

	pgsql_handle = Z_PGSQL_LINK_P(pgsql_link);
	CHECK_PGSQL_LINK(pgsql_handle);
	pgsql = pgsql_handle->conn;

	ret = PQconnectPoll(pgsql);

	RETURN_LONG(ret);
}
/* }}} */

/* {{{ Open a persistent PostgreSQL connection */
PHP_FUNCTION(pg_pconnect)
{
	php_pgsql_do_connect(INTERNAL_FUNCTION_PARAM_PASSTHRU,1);
}
/* }}} */

/* {{{ Close a PostgreSQL connection */
PHP_FUNCTION(pg_close)
{
	zval *pgsql_link = NULL;
	pgsql_link_handle *link;

	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|O!", &pgsql_link, pgsql_link_ce) == FAILURE) {
		RETURN_THROWS();
	}

	if (!pgsql_link) {
		link = FETCH_DEFAULT_LINK();
		CHECK_DEFAULT_LINK(link);
		zend_object_release(PGG(default_link));
		PGG(default_link) = NULL;
		RETURN_TRUE;
	}

	link = Z_PGSQL_LINK_P(pgsql_link);
	CHECK_PGSQL_LINK(link);

	if (link == FETCH_DEFAULT_LINK_NO_WARNING()) {
		GC_DELREF(PGG(default_link));
		PGG(default_link) = NULL;
	}
	pgsql_link_free(link);

	RETURN_TRUE;
}
/* }}} */

#define PHP_PG_DBNAME 1
#define PHP_PG_ERROR_MESSAGE 2
#define PHP_PG_OPTIONS 3
#define PHP_PG_PORT 4
#define PHP_PG_TTY 5
#define PHP_PG_HOST 6
#define PHP_PG_VERSION 7

/* php_pgsql_get_link_info */
static void php_pgsql_get_link_info(INTERNAL_FUNCTION_PARAMETERS, int entry_type)
{
	pgsql_link_handle *link;
	zval *pgsql_link = NULL;
	PGconn *pgsql;
	char *result;

	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|O!", &pgsql_link, pgsql_link_ce) == FAILURE) {
		RETURN_THROWS();
	}

	if (!pgsql_link) {
		link = FETCH_DEFAULT_LINK();
		CHECK_DEFAULT_LINK(link);
	} else {
		link = Z_PGSQL_LINK_P(pgsql_link);
		CHECK_PGSQL_LINK(link);
	}

	pgsql = link->conn;

	switch(entry_type) {
		case PHP_PG_DBNAME:
			result = PQdb(pgsql);
			break;
		case PHP_PG_ERROR_MESSAGE:
			RETURN_STR(_php_pgsql_trim_message(PQerrorMessage(pgsql)));
		case PHP_PG_OPTIONS:
			result = PQoptions(pgsql);
			break;
		case PHP_PG_PORT:
			result = PQport(pgsql);
			break;
		case PHP_PG_TTY:
			result = PQtty(pgsql);
			break;
		case PHP_PG_HOST:
			result = PQhost(pgsql);
			break;
		case PHP_PG_VERSION:
			array_init(return_value);
			add_assoc_string(return_value, "client", pgsql_libpq_version);
			add_assoc_long(return_value, "protocol", PQprotocolVersion(pgsql));
			if (PQprotocolVersion(pgsql) >= 3) {
				/* 8.0 or grater supports protorol version 3 */
				char *tmp;
				add_assoc_string(return_value, "server", (char*)PQparameterStatus(pgsql, "server_version"));

#define PHP_PQ_COPY_PARAM(_x) tmp = (char*)PQparameterStatus(pgsql, _x); \
	if(tmp) add_assoc_string(return_value, _x, tmp); \
	else add_assoc_null(return_value, _x);

				PHP_PQ_COPY_PARAM("server_encoding");
				PHP_PQ_COPY_PARAM("client_encoding");
				PHP_PQ_COPY_PARAM("is_superuser");
				PHP_PQ_COPY_PARAM("session_authorization");
				PHP_PQ_COPY_PARAM("DateStyle");
				PHP_PQ_COPY_PARAM("IntervalStyle");
				PHP_PQ_COPY_PARAM("TimeZone");
				PHP_PQ_COPY_PARAM("integer_datetimes");
				PHP_PQ_COPY_PARAM("standard_conforming_strings");
				PHP_PQ_COPY_PARAM("application_name");
			}
			return;
		EMPTY_SWITCH_DEFAULT_CASE()
	}
	if (result) {
		RETURN_STRING(result);
	} else {
		RETURN_EMPTY_STRING();
	}
}

/* Get the database name */
PHP_FUNCTION(pg_dbname)
{
	php_pgsql_get_link_info(INTERNAL_FUNCTION_PARAM_PASSTHRU,PHP_PG_DBNAME);
}

/* Get the error message string */
PHP_FUNCTION(pg_last_error)
{
	php_pgsql_get_link_info(INTERNAL_FUNCTION_PARAM_PASSTHRU,PHP_PG_ERROR_MESSAGE);
}

/* Get the options associated with the connection */
PHP_FUNCTION(pg_options)
{
	php_pgsql_get_link_info(INTERNAL_FUNCTION_PARAM_PASSTHRU,PHP_PG_OPTIONS);
}

/* Return the port number associated with the connection */
PHP_FUNCTION(pg_port)
{
	php_pgsql_get_link_info(INTERNAL_FUNCTION_PARAM_PASSTHRU,PHP_PG_PORT);
}

/* Return the tty name associated with the connection */
PHP_FUNCTION(pg_tty)
{
	php_pgsql_get_link_info(INTERNAL_FUNCTION_PARAM_PASSTHRU,PHP_PG_TTY);
}

/* Returns the host name associated with the connection */
PHP_FUNCTION(pg_host)
{
	php_pgsql_get_link_info(INTERNAL_FUNCTION_PARAM_PASSTHRU,PHP_PG_HOST);
}

/* Returns an array with client, protocol and server version (when available) */
PHP_FUNCTION(pg_version)
{
	php_pgsql_get_link_info(INTERNAL_FUNCTION_PARAM_PASSTHRU,PHP_PG_VERSION);
}

/* Returns the value of a server parameter */
PHP_FUNCTION(pg_parameter_status)
{
	zval *pgsql_link = NULL;
	pgsql_link_handle *link;
	PGconn *pgsql;
	char *param;
	size_t len;

	if (zend_parse_parameters_ex(ZEND_PARSE_PARAMS_QUIET, ZEND_NUM_ARGS(), "Os", &pgsql_link, pgsql_link_ce, &param, &len) == FAILURE) {
		if (zend_parse_parameters(ZEND_NUM_ARGS(), "s", &param, &len) == FAILURE) {
			RETURN_THROWS();
		}

		link = FETCH_DEFAULT_LINK();
		CHECK_DEFAULT_LINK(link);
	} else {
		link = Z_PGSQL_LINK_P(pgsql_link);
		CHECK_PGSQL_LINK(link);
	}

	pgsql = link->conn;

	param = (char*)PQparameterStatus(pgsql, param);
	if (param) {
		RETURN_STRING(param);
	} else {
		RETURN_FALSE;
	}
}

/* Ping database. If connection is bad, try to reconnect. */
PHP_FUNCTION(pg_ping)
{
	zval *pgsql_link = NULL;
	PGconn *pgsql;
	PGresult *res;
	pgsql_link_handle *link;

	if (zend_parse_parameters(ZEND_NUM_ARGS(), "|O!", &pgsql_link, pgsql_link_ce) == FAILURE) {
		RETURN_THROWS();
	}

	if (pgsql_link == NULL) {
		link = FETCH_DEFAULT_LINK();
		CHECK_DEFAULT_LINK(link);
	} else {
		link = Z_PGSQL_LINK_P(pgsql_link);
		CHECK_PGSQL_LINK(link);
	}

	pgsql = link->conn;

	/* ping connection */
	res = PQexec(pgsql, "SELECT 1;");
	PQclear(res);

	/* check status. */
	if (PQstatus(pgsql) == CONNECTION_OK)
		RETURN_TRUE;

	/* reset connection if it's broken */
	PQreset(pgsql);
	if (PQstatus(pgsql) == CONNECTION_OK) {
		RETURN_TRUE;
	}
	RETURN_FALSE;
}

/* Execute a query */
PHP_FUNCTION(pg_query)
{
	zval *pgsql_link = NULL;
	char *query;
	size_t query_len;
	int leftover = 0;
	pgsql_link_handle *link;
	PGconn *pgsql;
	PGresult *pgsql_result;
	ExecStatusType status;

	if (ZEND_NUM_ARGS() == 1) {
		if (zend_parse_parameters(ZEND_NUM_ARGS(), "s", &query, &query_len) == FAILURE) {
			RETURN_THROWS();
		}
		link = FETCH_DEFAULT_LINK();
		CHECK_DEFAULT_LINK(link);
	} else {
		if (zend_parse_parameters(ZEND_NUM_ARGS(), "Os", &pgsql_link, pgsql_link_ce, &query, &query_len) == FAILURE) {
			RETURN_THROWS();
		}
		link = Z_PGSQL_LINK_P(pgsql_link);
		CHECK_PGSQL_LINK(link);
	}

	pgsql = link->conn;

	if (PQsetnonblocking(pgsql, 0)) {
		php_error_docref(NULL, E_NOTICE,"Cannot set connection to blocking mode");
		RETURN_FALSE;
	}
	while ((pgsql_result = PQgetResult(pgsql))) {
		PQclear(pgsql_result);
		leftover = 1;
	}