1 files changed, 1344 insertions, 0 deletions

diff --git a/src/lib-sql/driver-pgsql.c b/src/lib-sql/driver-pgsql.c
new file mode 100644
index 0000000..63188c0
--- /dev/null
+++ b/src/lib-sql/driver-pgsql.c
@@ -0,0 +1,1344 @@
+/* Copyright (c) 2004-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "array.h"
+#include "ioloop.h"
+#include "hex-binary.h"
+#include "str.h"
+#include "time-util.h"
+#include "sql-api-private.h"
+#include "llist.h"
+
+#ifdef BUILD_PGSQL
+#include <libpq-fe.h>
+
+#define PGSQL_DNS_WARN_MSECS 500
+
+struct pgsql_db {
+	struct sql_db api;
+
+	pool_t pool;
+	char *connect_string;
+	char *host;
+	PGconn *pg;
+
+	struct io *io;
+	struct timeout *to_connect;
+	enum io_condition io_dir;
+
+	struct pgsql_result *pending_results;
+	struct pgsql_result *cur_result;
+	struct ioloop *ioloop, *orig_ioloop;
+	struct sql_result *sync_result;
+
+	bool (*next_callback)(void *);
+	void *next_context;
+
+	char *error;
+	const char *connect_state;
+
+	bool fatal_error:1;
+};
+
+struct pgsql_binary_value {
+	unsigned char *value;
+	size_t size;
+};
+
+struct pgsql_result {
+	struct sql_result api;
+
+	struct pgsql_result *prev, *next;
+
+	PGresult *pgres;
+	struct timeout *to;
+
+	unsigned int rownum, rows;
+	unsigned int fields_count;
+	const char **fields;
+	const char **values;
+	char *query;
+
+	ARRAY(struct pgsql_binary_value) binary_values;
+
+	sql_query_callback_t *callback;
+	void *context;
+
+	bool timeout:1;
+};
+
+struct pgsql_transaction_context {
+	struct sql_transaction_context ctx;
+	int refcount;
+
+	sql_commit_callback_t *callback;
+	void *context;
+
+	pool_t query_pool;
+	const char *error;
+
+	bool failed:1;
+};
+
+extern const struct sql_db driver_pgsql_db;
+extern const struct sql_result driver_pgsql_result;
+
+static void result_finish(struct pgsql_result *result);
+static void
+transaction_update_callback(struct sql_result *result,
+			    struct sql_transaction_query *query);
+
+static struct event_category event_category_pgsql = {
+	.parent = &event_category_sql,
+	.name = "pgsql"
+};
+
+static void driver_pgsql_set_state(struct pgsql_db *db, enum sql_db_state state)
+{
+	i_assert(state == SQL_DB_STATE_BUSY || db->cur_result == NULL);
+
+	/* switch back to original ioloop in case the caller wants to
+	   add/remove timeouts */
+	if (db->ioloop != NULL)
+		io_loop_set_current(db->orig_ioloop);
+	sql_db_set_state(&db->api, state);
+	if (db->ioloop != NULL)
+		io_loop_set_current(db->ioloop);
+}
+
+static bool driver_pgsql_next_callback(struct pgsql_db *db)
+{
+	bool (*next_callback)(void *) = db->next_callback;
+	void *next_context = db->next_context;
+
+	if (next_callback == NULL)
+		return FALSE;
+
+	db->next_callback = NULL;
+	db->next_context = NULL;
+	return next_callback(next_context);
+}
+
+static void driver_pgsql_stop_io(struct pgsql_db *db)
+{
+	if (db->io != NULL) {
+		io_remove(&db->io);
+		db->io_dir = 0;
+	}
+}
+
+static void driver_pgsql_close(struct pgsql_db *db)
+{
+	db->io_dir = 0;
+	db->fatal_error = FALSE;
+
+	driver_pgsql_stop_io(db);
+
+	PQfinish(db->pg);
+	db->pg = NULL;
+
+	timeout_remove(&db->to_connect);
+
+	driver_pgsql_set_state(db, SQL_DB_STATE_DISCONNECTED);
+
+	if (db->ioloop != NULL) {
+		/* running a sync query, stop it */
+		io_loop_stop(db->ioloop);
+	}
+	driver_pgsql_next_callback(db);
+}
+
+static const char *last_error(struct pgsql_db *db)
+{
+	const char *msg;
+	size_t len;
+
+	msg = PQerrorMessage(db->pg);
+	if (msg == NULL)
+		return "(no error set)";
+
+	/* Error message should contain trailing \n, we don't want it */
+	len = strlen(msg);
+	return len == 0 || msg[len-1] != '\n' ? msg :
+		t_strndup(msg, len-1);
+}
+
+static void connect_callback(struct pgsql_db *db)
+{
+	enum io_condition io_dir = 0;
+	int ret;
+
+	driver_pgsql_stop_io(db);
+
+	while ((ret = PQconnectPoll(db->pg)) == PGRES_POLLING_ACTIVE)
+		;
+
+	switch (ret) {
+	case PGRES_POLLING_READING:
+		db->connect_state = "wait for input";
+		io_dir = IO_READ;
+		break;
+	case PGRES_POLLING_WRITING:
+		db->connect_state = "wait for output";
+		io_dir = IO_WRITE;
+		break;
+	case PGRES_POLLING_OK:
+		break;
+	case PGRES_POLLING_FAILED:
+		e_error(db->api.event, "Connect failed to database %s: %s (state: %s)",
+			PQdb(db->pg), last_error(db), db->connect_state);
+		driver_pgsql_close(db);
+		return;
+	}
+
+	if (io_dir != 0) {
+		db->io = io_add(PQsocket(db->pg), io_dir, connect_callback, db);
+		db->io_dir = io_dir;
+	}
+
+	if (io_dir == 0) {
+		db->connect_state = "connected";
+		timeout_remove(&db->to_connect);
+		if (PQserverVersion(db->pg) >= 90500) {
+			/* v9.5+ */
+			db->api.flags |= SQL_DB_FLAG_ON_CONFLICT_DO;
+		}
+		driver_pgsql_set_state(db, SQL_DB_STATE_IDLE);
+		if (db->ioloop != NULL) {
+			/* driver_pgsql_sync_init() waiting for connection to
+			   finish */
+			io_loop_stop(db->ioloop);
+		}
+	}
+}
+
+static void driver_pgsql_connect_timeout(struct pgsql_db *db)
+{
+	unsigned int secs = ioloop_time - db->api.last_connect_try;
+
+	e_error(db->api.event, "Connect failed: Timeout after %u seconds (state: %s)",
+		secs, db->connect_state);
+	driver_pgsql_close(db);
+}
+
+static int driver_pgsql_connect(struct sql_db *_db)
+{
+	struct pgsql_db *db = (struct pgsql_db *)_db;
+	struct timeval tv_start;
+	int msecs;
+
+	i_assert(db->api.state == SQL_DB_STATE_DISCONNECTED);
+
+	io_loop_time_refresh();
+	tv_start = ioloop_timeval;
+
+	db->pg = PQconnectStart(db->connect_string);
+	if (db->pg == NULL) {
+		i_fatal("pgsql: PQconnectStart() failed (out of memory)");
+	}
+
+	if (PQstatus(db->pg) == CONNECTION_BAD) {
+		e_error(_db->event, "Connect failed to database %s: %s",
+			PQdb(db->pg), last_error(db));
+		driver_pgsql_close(db);
+		return -1;
+	}
+	/* PQconnectStart() blocks on host name resolving. Log a warning if
+	   it takes too long. Also don't include time spent on that in the
+	   connect timeout (by refreshing ioloop time). */
+	io_loop_time_refresh();
+	msecs = timeval_diff_msecs(&ioloop_timeval, &tv_start);
+	if (msecs > PGSQL_DNS_WARN_MSECS) {
+		e_warning(_db->event, "DNS lookup took %d.%03d s",
+			  msecs/1000, msecs % 1000);
+	}
+
+	/* nonblocking connecting begins. */
+	if (PQsetnonblocking(db->pg, 1) < 0)
+		e_error(_db->event, "PQsetnonblocking() failed");
+	i_assert(db->to_connect == NULL);
+	db->to_connect = timeout_add(SQL_CONNECT_TIMEOUT_SECS * 1000,
+				     driver_pgsql_connect_timeout, db);
+	db->connect_state = "connecting";
+	db->io = io_add(PQsocket(db->pg), IO_WRITE, connect_callback, db);
+	db->io_dir = IO_WRITE;
+	driver_pgsql_set_state(db, SQL_DB_STATE_CONNECTING);
+	return 0;
+}
+
+static void driver_pgsql_disconnect(struct sql_db *_db)
+{
+	struct pgsql_db *db = (struct pgsql_db *)_db;
+
+	if (db->cur_result != NULL && db->cur_result->to != NULL) {
+		driver_pgsql_stop_io(db);
+		result_finish(db->cur_result);
+	}
+
+	_db->no_reconnect = TRUE;
+	driver_pgsql_close(db);
+	_db->no_reconnect = FALSE;
+}
+
+static void driver_pgsql_free(struct pgsql_db **_db)
+{
+	struct pgsql_db *db = *_db;
+	*_db = NULL;
+
+	event_unref(&db->api.event);
+	i_free(db->connect_string);
+	i_free(db->host);
+	i_free(db->error);
+	array_free(&db->api.module_contexts);
+	i_free(db);
+}
+
+static enum sql_db_flags driver_pgsql_get_flags(struct sql_db *db)
+{
+	switch (db->state) {
+	case SQL_DB_STATE_DISCONNECTED:
+		if (sql_connect(db) < 0)
+			break;
+		/* fall through */
+	case SQL_DB_STATE_CONNECTING:
+		/* Wait for connection to finish, so we can get the flags
+		   reliably. */
+		sql_wait(db);
+		break;
+	case SQL_DB_STATE_IDLE:
+	case SQL_DB_STATE_BUSY:
+		break;
+	}
+	return db->flags;
+}
+
+static int driver_pgsql_init_full_v(const struct sql_settings *set,
+				    struct sql_db **db_r, const char **error_r ATTR_UNUSED)
+{
+	struct pgsql_db *db;
+
+	db = i_new(struct pgsql_db, 1);
+	db->connect_string = i_strdup(set->connect_string);
+	db->api = driver_pgsql_db;
+	db->api.event = event_create(set->event_parent);
+	event_add_category(db->api.event, &event_category_pgsql);
+
+	/* NOTE: Connection string will be parsed by pgsql itself
+		 We only pick the host part here */
+	T_BEGIN {
+		const char *const *arg = t_strsplit(db->connect_string, " ");
+
+		for (; *arg != NULL; arg++) {
+			if (str_begins(*arg, "host="))
+				db->host = i_strdup(*arg + 5);
+
+		}
+	} T_END;
+
+	event_set_append_log_prefix(db->api.event, t_strdup_printf("pgsql(%s): ", db->host));
+
+	*db_r = &db->api;
+	return 0;
+}
+
+static void driver_pgsql_deinit_v(struct sql_db *_db)
+{
+	struct pgsql_db *db = (struct pgsql_db *)_db;
+
+	driver_pgsql_disconnect(_db);
+	driver_pgsql_free(&db);
+}
+
+static void driver_pgsql_set_idle(struct pgsql_db *db)
+{
+	i_assert(db->api.state == SQL_DB_STATE_BUSY);
+
+	if (db->fatal_error)
+		driver_pgsql_close(db);
+	else if (!driver_pgsql_next_callback(db))
+		driver_pgsql_set_state(db, SQL_DB_STATE_IDLE);
+}
+
+static void consume_results(struct pgsql_db *db)
+{
+	PGresult *pgres;
+
+	driver_pgsql_stop_io(db);
+
+	while (PQconsumeInput(db->pg) != 0) {
+		if (PQisBusy(db->pg) != 0) {
+			db->io = io_add(PQsocket(db->pg), IO_READ,
+					consume_results, db);
+			db->io_dir = IO_READ;
+			return;
+		}
+
+		pgres = PQgetResult(db->pg);
+		if (pgres == NULL)
+			break;
+		PQclear(pgres);
+	}
+
+	if (PQstatus(db->pg) == CONNECTION_BAD)
+		driver_pgsql_close(db);
+	else
+		driver_pgsql_set_idle(db);
+}
+
+static void driver_pgsql_result_free(struct sql_result *_result)
+{
+	struct pgsql_db *db = (struct pgsql_db *)_result->db;
+        struct pgsql_result *result = (struct pgsql_result *)_result;
+	bool success;
+
+	i_assert(!result->api.callback);
+	i_assert(db->cur_result == result);
+	i_assert(result->callback == NULL);
+
+	if (_result == db->sync_result)
+		db->sync_result = NULL;
+	db->cur_result = NULL;
+
+	success = result->pgres != NULL && !db->fatal_error;
+	if (result->pgres != NULL) {
+		PQclear(result->pgres);
+		result->pgres = NULL;
+	}
+
+	if (success) {
+		/* we'll have to read the rest of the results as well */
+		i_assert(db->io == NULL);
+		consume_results(db);
+	} else {
+		driver_pgsql_set_idle(db);
+	}
+
+	if (array_is_created(&result->binary_values)) {
+		struct pgsql_binary_value *value;
+
+		array_foreach_modifiable(&result->binary_values, value)
+			PQfreemem(value->value);
+		array_free(&result->binary_values);
+	}
+
+	event_unref(&result->api.event);
+	i_free(result->query);
+	i_free(result->fields);
+	i_free(result->values);
+	i_free(result);
+}
+
+static void result_finish(struct pgsql_result *result)
+{
+	struct pgsql_db *db = (struct pgsql_db *)result->api.db;
+	bool free_result = TRUE;
+	int duration;
+
+	i_assert(db->io == NULL);
+	timeout_remove(&result->to);
+	DLLIST_REMOVE(&db->pending_results, result);
+
+	/* if connection to server was lost, we don't yet see that the
+	   connection is bad. we only see the fatal error, so assume it also
+	   means disconnection. */
+	if (PQstatus(db->pg) == CONNECTION_BAD || result->pgres == NULL ||
+	    PQresultStatus(result->pgres) == PGRES_FATAL_ERROR)
+		db->fatal_error = TRUE;
+
+	if (db->fatal_error) {
+		result->api.failed = TRUE;
+		result->api.failed_try_retry = TRUE;
+	}
+
+	/* emit event */
+	if (result->api.failed) {
+		const char *error = result->timeout ? "Timed out" : last_error(db);
+		struct event_passthrough *e =
+			sql_query_finished_event(&db->api, result->api.event,
+						 result->query, TRUE, &duration);
+		e->add_str("error", error);
+		e_debug(e->event(), SQL_QUERY_FINISHED_FMT": %s", result->query,
+			duration, error);
+	} else {
+		e_debug(sql_query_finished_event(&db->api, result->api.event,
+						 result->query, FALSE, &duration)->
+						 event(),
+			SQL_QUERY_FINISHED_FMT, result->query, duration);
+	}
+	result->api.callback = TRUE;
+	T_BEGIN {
+		if (result->callback != NULL)
+			result->callback(&result->api, result->context);
+	} T_END;
+	result->api.callback = FALSE;
+
+	free_result = db->sync_result != &result->api;
+	if (db->ioloop != NULL)
+		io_loop_stop(db->ioloop);
+
+	i_assert(!free_result || result->api.refcount > 0);
+	result->callback = NULL;
+	if (free_result)
+		sql_result_unref(&result->api);
+}
+
+static void get_result(struct pgsql_result *result)
+{
+        struct pgsql_db *db = (struct pgsql_db *)result->api.db;
+
+	driver_pgsql_stop_io(db);
+
+	if (PQconsumeInput(db->pg) == 0) {
+		result_finish(result);
+		return;
+	}
+
+	if (PQisBusy(db->pg) != 0) {
+		db->io = io_add(PQsocket(db->pg), IO_READ,
+				get_result, result);
+		db->io_dir = IO_READ;
+		return;
+	}
+
+	result->pgres = PQgetResult(db->pg);
+	result_finish(result);
+}
+
+static void flush_callback(struct pgsql_result *result)
+{
+        struct pgsql_db *db = (struct pgsql_db *)result->api.db;
+	int ret;
+
+	driver_pgsql_stop_io(db);
+
+	ret = PQflush(db->pg);
+	if (ret > 0) {
+		db->io = io_add(PQsocket(db->pg), IO_WRITE,
+				flush_callback, result);
+		db->io_dir = IO_WRITE;
+		return;
+	}
+
+	if (ret < 0) {
+		result_finish(result);
+	} else {
+		/* all flushed */
+		get_result(result);
+	}
+}
+
+static void query_timeout(struct pgsql_result *result)
+{
+        struct pgsql_db *db = (struct pgsql_db *)result->api.db;
+
+	driver_pgsql_stop_io(db);
+
+	result->timeout = TRUE;
+	result_finish(result);
+}
+
+static void do_query(struct pgsql_result *result, const char *query)
+{
+        struct pgsql_db *db = (struct pgsql_db *)result->api.db;
+	int ret;
+
+	i_assert(SQL_DB_IS_READY(&db->api));
+	i_assert(db->cur_result == NULL);
+	i_assert(db->io == NULL);
+
+	driver_pgsql_set_state(db, SQL_DB_STATE_BUSY);
+	db->cur_result = result;
+	DLLIST_PREPEND(&db->pending_results, result);
+	result->to = timeout_add(SQL_QUERY_TIMEOUT_SECS * 1000,
+				 query_timeout, result);
+	result->query = i_strdup(query);
+
+	if (PQsendQuery(db->pg, query) == 0 ||
+	    (ret = PQflush(db->pg)) < 0) {
+		/* failed to send query */
+		result_finish(result);
+		return;
+	}
+
+	if (ret > 0) {
+		/* write blocks */
+		db->io = io_add(PQsocket(db->pg), IO_WRITE,
+				flush_callback, result);
+		db->io_dir = IO_WRITE;
+	} else {
+		get_result(result);
+	}
+}
+
+static const char *
+driver_pgsql_escape_string(struct sql_db *_db, const char *string)
+{
+	struct pgsql_db *db = (struct pgsql_db *)_db;
+	size_t len = strlen(string);
+	char *to;
+
+#ifdef HAVE_PQESCAPE_STRING_CONN
+	if (db->api.state == SQL_DB_STATE_DISCONNECTED) {
+		/* try connecting again */
+		(void)sql_connect(&db->api);
+	}
+	if (db->api.state != SQL_DB_STATE_DISCONNECTED) {
+		int error;
+
+		to = t_buffer_get(len * 2 + 1);
+		len = PQescapeStringConn(db->pg, to, string, len, &error);
+	} else
+#endif
+	{
+		to = t_buffer_get(len * 2 + 1);
+		len = PQescapeString(to, string, len);
+	}
+	t_buffer_alloc(len + 1);
+	return to;
+}
+
+static void exec_callback(struct sql_result *_result,
+			  void *context ATTR_UNUSED)
+{
+	struct pgsql_result *result = (struct pgsql_result*)_result;
+	result_finish(result);
+}
+
+static void driver_pgsql_exec(struct sql_db *db, const char *query)
+{
+	struct pgsql_result *result;
+
+	result = i_new(struct pgsql_result, 1);
+	result->api = driver_pgsql_result;
+	result->api.db = db;
+	result->api.refcount = 1;
+	result->api.event = event_create(db->event);
+	result->callback = exec_callback;
+	do_query(result, query);
+}
+
+static void driver_pgsql_query(struct sql_db *db, const char *query,
+			       sql_query_callback_t *callback, void *context)
+{
+	struct pgsql_result *result;
+
+	result = i_new(struct pgsql_result, 1);
+	result->api = driver_pgsql_result;
+	result->api.db = db;
+	result->api.refcount = 1;
+	result->api.event = event_create(db->event);
+	result->callback = callback;
+	result->context = context;
+	do_query(result, query);
+}
+
+static void pgsql_query_s_callback(struct sql_result *result, void *context)
+{
+        struct pgsql_db *db = context;
+
+	db->sync_result = result;
+}
+
+static void driver_pgsql_sync_init(struct pgsql_db *db)
+{
+	bool add_to_connect;
+
+	db->orig_ioloop = current_ioloop;
+	if (db->io == NULL) {
+		db->ioloop = io_loop_create();
+		return;
+	}
+
+	i_assert(db->api.state == SQL_DB_STATE_CONNECTING);
+
+	/* have to move our existing I/O and timeout handlers to new I/O loop */
+	io_remove(&db->io);
+
+	add_to_connect = (db->to_connect != NULL);
+	timeout_remove(&db->to_connect);
+
+	db->ioloop = io_loop_create();
+	if (add_to_connect) {
+		db->to_connect = timeout_add(SQL_CONNECT_TIMEOUT_SECS * 1000,
+					     driver_pgsql_connect_timeout, db);
+	}
+	db->io = io_add(PQsocket(db->pg), db->io_dir, connect_callback, db);
+	/* wait for connecting to finish */
+	io_loop_run(db->ioloop);
+}
+
+static void driver_pgsql_sync_deinit(struct pgsql_db *db)
+{
+	io_loop_destroy(&db->ioloop);
+}
+
+static struct sql_result *
+driver_pgsql_sync_query(struct pgsql_db *db, const char *query)
+{
+	struct sql_result *result;
+
+	i_assert(db->sync_result == NULL);
+
+	switch (db->api.state) {
+	case SQL_DB_STATE_CONNECTING:
+	case SQL_DB_STATE_BUSY:
+		i_unreached();
+	case SQL_DB_STATE_DISCONNECTED:
+		sql_not_connected_result.refcount++;
+		return &sql_not_connected_result;
+	case SQL_DB_STATE_IDLE:
+		break;
+	}
+
+	driver_pgsql_query(&db->api, query, pgsql_query_s_callback, db);
+	if (db->sync_result == NULL)
+		io_loop_run(db->ioloop);
+
+	i_assert(db->io == NULL);
+
+	result = db->sync_result;
+	if (result == &sql_not_connected_result) {
+		/* we don't end up in pgsql's free function, so sync_result
+		   won't be set to NULL if we don't do it here. */
+		db->sync_result = NULL;
+	} else if (result == NULL) {
+		result = &sql_not_connected_result;
+		result->refcount++;
+	}
+
+	i_assert(db->io == NULL);
+	return result;
+}
+
+static struct sql_result *
+driver_pgsql_query_s(struct sql_db *_db, const char *query)
+{
+	struct pgsql_db *db = (struct pgsql_db *)_db;
+	struct sql_result *result;
+
+	driver_pgsql_sync_init(db);
+	result = driver_pgsql_sync_query(db, query);
+	driver_pgsql_sync_deinit(db);
+	return result;
+}
+
+static int driver_pgsql_result_next_row(struct sql_result *_result)
+{
+	struct pgsql_result *result = (struct pgsql_result *)_result;
+	struct pgsql_db *db = (struct pgsql_db *)_result->db;
+
+	if (result->rows != 0) {
+		/* second time we're here */
+		if (++result->rownum < result->rows)
+			return 1;
+
+		/* end of this packet. see if there's more. FIXME: this may
+		   block, but the current API doesn't provide a non-blocking
+		   way to do this.. */
+		PQclear(result->pgres);
+		result->pgres = PQgetResult(db->pg);
+		if (result->pgres == NULL)
+			return 0;
+	}
+
+	if (result->pgres == NULL) {
+		_result->failed = TRUE;
+		return -1;
+	}
+
+	switch (PQresultStatus(result->pgres)) {
+	case PGRES_COMMAND_OK:
+		/* no rows returned */
+		return 0;
+	case PGRES_TUPLES_OK:
+		result->rows = PQntuples(result->pgres);
+		return result->rows > 0 ? 1 : 0;
+	case PGRES_EMPTY_QUERY:
+	case PGRES_NONFATAL_ERROR:
+		/* nonfatal error */
+		_result->failed = TRUE;
+		return -1;
+	default:
+		/* treat as fatal error */
+		_result->failed = TRUE;
+		db->fatal_error = TRUE;
+		return -1;
+	}
+}
+
+static void driver_pgsql_result_fetch_fields(struct pgsql_result *result)
+{
+	unsigned int i;
+
+	if (result->fields != NULL)
+		return;
+
+	/* @UNSAFE */
+	result->fields_count = PQnfields(result->pgres);
+	result->fields = i_new(const char *, result->fields_count);
+	for (i = 0; i < result->fields_count; i++)
+		result->fields[i] = PQfname(result->pgres, i);
+}
+
+static unsigned int
+driver_pgsql_result_get_fields_count(struct sql_result *_result)
+{
+	struct pgsql_result *result = (struct pgsql_result *)_result;
+
+        driver_pgsql_result_fetch_fields(result);
+	return result->fields_count;
+}
+
+static const char *
+driver_pgsql_result_get_field_name(struct sql_result *_result, unsigned int idx)
+{
+	struct pgsql_result *result = (struct pgsql_result *)_result;
+
+	driver_pgsql_result_fetch_fields(result);
+	i_assert(idx < result->fields_count);
+	return result->fields[idx];
+}
+
+static int driver_pgsql_result_find_field(struct sql_result *_result,
+					  const char *field_name)
+{
+	struct pgsql_result *result = (struct pgsql_result *)_result;
+	unsigned int i;
+
+	driver_pgsql_result_fetch_fields(result);
+	for (i = 0; i < result->fields_count; i++) {
+		if (strcmp(result->fields[i], field_name) == 0)
+			return i;
+	}
+	return -1;
+}
+
+static const char *
+driver_pgsql_result_get_field_value(struct sql_result *_result,
+				    unsigned int idx)
+{
+	struct pgsql_result *result = (struct pgsql_result *)_result;
+
+	if (PQgetisnull(result->pgres, result->rownum, idx) != 0)
+		return NULL;
+
+	return PQgetvalue(result->pgres, result->rownum, idx);
+}
+
+static const unsigned char *
+driver_pgsql_result_get_field_value_binary(struct sql_result *_result,
+					   unsigned int idx, size_t *size_r)
+{
+	struct pgsql_result *result = (struct pgsql_result *)_result;
+	const char *value;
+	struct pgsql_binary_value *binary_value;
+
+	if (PQgetisnull(result->pgres, result->rownum, idx) != 0) {
+		*size_r = 0;
+		return NULL;
+	}
+
+	value = PQgetvalue(result->pgres, result->rownum, idx);
+
+	if (!array_is_created(&result->binary_values))
+		i_array_init(&result->binary_values, idx + 1);
+
+	binary_value = array_idx_get_space(&result->binary_values, idx);
+	if (binary_value->value == NULL) {
+		binary_value->value =
+			PQunescapeBytea((const unsigned char *)value,
+					&binary_value->size);
+	}
+
+	*size_r = binary_value->size;
+	return binary_value->value;
+}
+
+static const char *
+driver_pgsql_result_find_field_value(struct sql_result *result,
+				     const char *field_name)
+{
+	int idx;
+
+	idx = driver_pgsql_result_find_field(result, field_name);
+	if (idx < 0)
+		return NULL;
+	return driver_pgsql_result_get_field_value(result, idx);
+}
+
+static const char *const *
+driver_pgsql_result_get_values(struct sql_result *_result)
+{
+	struct pgsql_result *result = (struct pgsql_result *)_result;
+	unsigned int i;
+
+	if (result->values == NULL) {
+		driver_pgsql_result_fetch_fields(result);
+		result->values = i_new(const char *, result->fields_count);
+	}
+
+	/* @UNSAFE */
+	for (i = 0; i < result->fields_count; i++) {
+		result->values[i] =
+                        driver_pgsql_result_get_field_value(_result, i);
+	}
+
+	return result->values;
+}
+
+static const char *driver_pgsql_result_get_error(struct sql_result *_result)
+{
+	struct pgsql_result *result = (struct pgsql_result *)_result;
+	struct pgsql_db *db = (struct pgsql_db *)_result->db;
+	const char *msg;
+	size_t len;
+
+	i_free_and_null(db->error);
+
+	if (result->timeout) {
+		db->error = i_strdup("Query timed out");
+	} else if (result->pgres == NULL) {
+		/* connection error */
+		db->error = i_strdup(last_error(db));
+	} else {
+		msg = PQresultErrorMessage(result->pgres);
+		if (msg == NULL)
+			return "(no error set)";
+
+		/* Error message should contain trailing \n, we don't want it */
+		len = strlen(msg);
+		db->error = len == 0 || msg[len-1] != '\n' ?
+			i_strdup(msg) : i_strndup(msg, len-1);
+	}
+	return db->error;
+}
+
+static struct sql_transaction_context *
+driver_pgsql_transaction_begin(struct sql_db *db)
+{
+	struct pgsql_transaction_context *ctx;
+
+	ctx = i_new(struct pgsql_transaction_context, 1);
+	ctx->ctx.db = db;
+	ctx->ctx.event = event_create(db->event);
+	/* we need to be able to handle multiple open transactions, so at least
+	   for now just keep them in memory until commit time. */
+	ctx->query_pool = pool_alloconly_create("pgsql transaction", 1024);
+	return &ctx->ctx;
+}
+
+static void
+driver_pgsql_transaction_free(struct pgsql_transaction_context *ctx)
+{
+	pool_unref(&ctx->query_pool);
+	event_unref(&ctx->ctx.event);
+	i_free(ctx);
+}
+
+static void
+transaction_commit_callback(struct sql_result *result,
+			    struct pgsql_transaction_context *ctx)
+{
+	struct sql_commit_result commit_result;
+
+	i_zero(&commit_result);
+	if (sql_result_next_row(result) < 0) {
+		commit_result.error = sql_result_get_error(result);
+		commit_result.error_type = sql_result_get_error_type(result);
+	}
+	ctx->callback(&commit_result, ctx->context);
+	driver_pgsql_transaction_free(ctx);
+}
+
+static bool transaction_send_next(void *context)
+{
+	struct pgsql_transaction_context *ctx = context;
+
+	i_assert(!ctx->failed);
+
+	if (ctx->ctx.db->state == SQL_DB_STATE_BUSY) {
+		/* kludgy.. */
+		ctx->ctx.db->state = SQL_DB_STATE_IDLE;
+	} else if (!SQL_DB_IS_READY(ctx->ctx.db)) {
+		struct sql_commit_result commit_result = {
+			.error = "Not connected"
+		};
+		ctx->callback(&commit_result, ctx->context);
+		return FALSE;
+	}
+
+	if (ctx->ctx.head != NULL) {
+		struct sql_transaction_query *query = ctx->ctx.head;
+
+		ctx->ctx.head = ctx->ctx.head->next;
+		sql_query(ctx->ctx.db, query->query,
+			  transaction_update_callback, query);
+	} else {
+		sql_query(ctx->ctx.db, "COMMIT",
+			  transaction_commit_callback, ctx);
+	}
+	return TRUE;
+}
+
+static void
+transaction_commit_error_callback(struct pgsql_transaction_context *ctx,
+				  struct sql_result *result)
+{
+	struct sql_commit_result commit_result;
+
+	i_zero(&commit_result);
+	commit_result.error = sql_result_get_error(result);
+	commit_result.error_type = sql_result_get_error_type(result);
+	e_debug(sql_transaction_finished_event(&ctx->ctx)->
+		add_str("error", commit_result.error)->event(),
+		"Transaction failed: %s", commit_result.error);
+	ctx->callback(&commit_result, ctx->context);
+}
+
+static void
+transaction_begin_callback(struct sql_result *result,
+			   struct pgsql_transaction_context *ctx)
+{
+	struct pgsql_db *db = (struct pgsql_db *)result->db;
+
+	i_assert(result->db == ctx->ctx.db);
+
+	if (sql_result_next_row(result) < 0) {
+		transaction_commit_error_callback(ctx, result);
+		driver_pgsql_transaction_free(ctx);
+		return;
+	}
+	i_assert(db->next_callback == NULL);
+	db->next_callback = transaction_send_next;
+	db->next_context = ctx;
+}
+
+static void
+transaction_update_callback(struct sql_result *result,
+			    struct sql_transaction_query *query)
+{
+	struct pgsql_transaction_context *ctx =
+		(struct pgsql_transaction_context *)query->trans;
+	struct pgsql_db *db = (struct pgsql_db *)result->db;
+
+	if (sql_result_next_row(result) < 0) {
+		transaction_commit_error_callback(ctx, result);
+		driver_pgsql_transaction_free(ctx);
+		return;
+	}
+
+	if (query->affected_rows != NULL) {
+		struct pgsql_result *pg_result = (struct pgsql_result *)result;
+
+		if (str_to_uint(PQcmdTuples(pg_result->pgres),
+				query->affected_rows) < 0)
+			i_unreached();
+	}
+	i_assert(db->next_callback == NULL);
+	db->next_callback = transaction_send_next;
+	db->next_context = ctx;
+}
+
+static void
+transaction_trans_query_callback(struct sql_result *result,
+				 struct sql_transaction_query *query)
+{
+	struct pgsql_transaction_context *ctx =
+		(struct pgsql_transaction_context *)query->trans;
+	struct sql_commit_result commit_result;
+
+	if (sql_result_next_row(result) < 0) {
+		transaction_commit_error_callback(ctx, result);
+		driver_pgsql_transaction_free(ctx);
+		return;
+	}
+
+	if (query->affected_rows != NULL) {
+		struct pgsql_result *pg_result = (struct pgsql_result *)result;
+
+		if (str_to_uint(PQcmdTuples(pg_result->pgres),
+				query->affected_rows) < 0)
+			i_unreached();
+	}
+	e_debug(sql_transaction_finished_event(&ctx->ctx)->event(),
+		"Transaction committed");
+	i_zero(&commit_result);
+	ctx->callback(&commit_result, ctx->context);
+	driver_pgsql_transaction_free(ctx);
+}
+
+static void
+driver_pgsql_transaction_commit(struct sql_transaction_context *_ctx,
+				sql_commit_callback_t *callback, void *context)
+{
+	struct pgsql_transaction_context *ctx =
+		(struct pgsql_transaction_context *)_ctx;
+	struct sql_commit_result result;
+
+	i_zero(&result);
+	ctx->callback = callback;
+	ctx->context = context;
+
+	if (ctx->failed || _ctx->head == NULL) {
+		if (ctx->failed) {
+			result.error = ctx->error;
+			e_debug(sql_transaction_finished_event(_ctx)->
+				add_str("error", ctx->error)->event(),
+				"Transaction failed: %s", ctx->error);
+		} else {
+			e_debug(sql_transaction_finished_event(_ctx)->event(),
+				"Transaction committed");
+		}
+		callback(&result, context);
+		driver_pgsql_transaction_free(ctx);
+	} else if (_ctx->head->next == NULL) {
+		/* just a single query, send it */
+		sql_query(_ctx->db, _ctx->head->query,
+			  transaction_trans_query_callback, _ctx->head);
+	} else {
+		/* multiple queries, use a transaction */
+		i_assert(_ctx->db->v.query == driver_pgsql_query);
+		sql_query(_ctx->db, "BEGIN", transaction_begin_callback, ctx);
+	}
+}
+
+static void
+commit_multi_fail(struct pgsql_transaction_context *ctx,
+		  struct sql_result *result, const char *query)
+{
+	ctx->failed = TRUE;
+	ctx->error = t_strdup_printf("%s (query: %s)",
+				     sql_result_get_error(result), query);
+	sql_result_unref(result);
+}
+
+static struct sql_result *
+driver_pgsql_transaction_commit_multi(struct pgsql_transaction_context *ctx)
+{
+	struct pgsql_db *db = (struct pgsql_db *)ctx->ctx.db;
+	struct sql_result *result;
+	struct sql_transaction_query *query;
+
+	result = driver_pgsql_sync_query(db, "BEGIN");
+	if (sql_result_next_row(result) < 0) {
+		commit_multi_fail(ctx, result, "BEGIN");
+		return NULL;
+	}
+	sql_result_unref(result);
+
+	/* send queries */
+	for (query = ctx->ctx.head; query != NULL; query = query->next) {
+		result = driver_pgsql_sync_query(db, query->query);
+		if (sql_result_next_row(result) < 0) {
+			commit_multi_fail(ctx, result, query->query);
+			break;
+		}
+		if (query->affected_rows != NULL) {
+			struct pgsql_result *pg_result =
+				(struct pgsql_result *)result;
+
+			if (str_to_uint(PQcmdTuples(pg_result->pgres),
+					query->affected_rows) < 0)
+				i_unreached();
+		}
+		sql_result_unref(result);
+	}
+
+	return driver_pgsql_sync_query(db, ctx->failed ?
+				       "ROLLBACK" : "COMMIT");
+}
+
+static void
+driver_pgsql_try_commit_s(struct pgsql_transaction_context *ctx,
+			  const char **error_r)
+{
+	struct sql_transaction_context *_ctx = &ctx->ctx;
+	struct pgsql_db *db = (struct pgsql_db *)_ctx->db;
+	struct sql_transaction_query *single_query = NULL;
+	struct sql_result *result;
+
+	if (_ctx->head->next == NULL) {
+		/* just a single query, send it */
+		single_query = _ctx->head;
+		result = sql_query_s(_ctx->db, single_query->query);
+	} else {
+		/* multiple queries, use a transaction */
+		driver_pgsql_sync_init(db);
+		result = driver_pgsql_transaction_commit_multi(ctx);
+		driver_pgsql_sync_deinit(db);
+	}
+
+	if (ctx->failed) {
+		i_assert(ctx->error != NULL);
+		e_debug(sql_transaction_finished_event(_ctx)->
+			add_str("error", ctx->error)->event(),
+			"Transaction failed: %s", ctx->error);
+		*error_r = ctx->error;
+	} else if (result != NULL) {
+		if (sql_result_next_row(result) < 0)
+			*error_r = sql_result_get_error(result);
+		else if (single_query != NULL &&
+			 single_query->affected_rows != NULL) {
+			struct pgsql_result *pg_result =
+				(struct pgsql_result *)result;
+
+			if (str_to_uint(PQcmdTuples(pg_result->pgres),
+					single_query->affected_rows) < 0)
+				i_unreached();
+		}
+	}
+
+	if (!ctx->failed) {
+		e_debug(sql_transaction_finished_event(_ctx)->event(),
+			"Transaction committed");
+	}
+
+	if (result != NULL)
+		sql_result_unref(result);
+}
+
+static int
+driver_pgsql_transaction_commit_s(struct sql_transaction_context *_ctx,
+				  const char **error_r)
+{
+	struct pgsql_transaction_context *ctx =
+		(struct pgsql_transaction_context *)_ctx;
+	struct pgsql_db *db = (struct pgsql_db *)_ctx->db;
+
+	*error_r = NULL;
+
+	if (_ctx->head != NULL) {
+		driver_pgsql_try_commit_s(ctx, error_r);
+		if (_ctx->db->state == SQL_DB_STATE_DISCONNECTED) {
+			*error_r = t_strdup(*error_r);
+			e_info(db->api.event, "Disconnected from database, "
+			       "retrying commit");
+			if (sql_connect(_ctx->db) >= 0) {
+				ctx->failed = FALSE;
+				*error_r = NULL;
+				driver_pgsql_try_commit_s(ctx, error_r);
+			}
+		}
+	}
+
+	driver_pgsql_transaction_free(ctx);
+	return *error_r == NULL ? 0 : -1;
+}
+
+static void
+driver_pgsql_transaction_rollback(struct sql_transaction_context *_ctx)
+{
+	struct pgsql_transaction_context *ctx =
+		(struct pgsql_transaction_context *)_ctx;
+	e_debug(sql_transaction_finished_event(_ctx)->
+			add_str("error", "Rolled back")->event(),
+		"Transaction rolled back");
+
+	driver_pgsql_transaction_free(ctx);
+}
+
+static void
+driver_pgsql_update(struct sql_transaction_context *_ctx, const char *query,
+		    unsigned int *affected_rows)
+{
+	struct pgsql_transaction_context *ctx =
+		(struct pgsql_transaction_context *)_ctx;
+
+	sql_transaction_add_query(_ctx, ctx->query_pool, query, affected_rows);
+}
+
+static const char *
+driver_pgsql_escape_blob(struct sql_db *_db ATTR_UNUSED,
+			 const unsigned char *data, size_t size)
+{
+	string_t *str = t_str_new(128);
+
+	str_append(str, "E'\\\\x");
+	binary_to_hex_append(str, data, size);
+	str_append_c(str, '\'');
+	return str_c(str);
+}
+
+static bool driver_pgsql_have_work(struct pgsql_db *db)
+{
+	return db->next_callback != NULL || db->pending_results != NULL ||
+		db->api.state == SQL_DB_STATE_CONNECTING;
+}
+
+static void driver_pgsql_wait(struct sql_db *_db)
+{
+	struct pgsql_db *db = (struct pgsql_db *)_db;
+
+	if (!driver_pgsql_have_work(db))
+		return;
+
+	db->orig_ioloop = current_ioloop;
+	db->ioloop = io_loop_create();
+	db->io = io_loop_move_io(&db->io);
+	while (driver_pgsql_have_work(db))
+		io_loop_run(db->ioloop);
+
+	io_loop_set_current(db->orig_ioloop);
+	db->io = io_loop_move_io(&db->io);
+	io_loop_set_current(db->ioloop);
+	io_loop_destroy(&db->ioloop);
+}
+
+const struct sql_db driver_pgsql_db = {
+	.name = "pgsql",
+	.flags = SQL_DB_FLAG_POOLED,
+
+	.v = {
+		.get_flags = driver_pgsql_get_flags,
+		.init_full = driver_pgsql_init_full_v,
+		.deinit = driver_pgsql_deinit_v,
+		.connect = driver_pgsql_connect,
+		.disconnect = driver_pgsql_disconnect,
+		.escape_string = driver_pgsql_escape_string,
+		.exec = driver_pgsql_exec,
+		.query = driver_pgsql_query,
+		.query_s = driver_pgsql_query_s,
+		.wait = driver_pgsql_wait,
+
+		.transaction_begin = driver_pgsql_transaction_begin,
+		.transaction_commit = driver_pgsql_transaction_commit,
+		.transaction_commit_s = driver_pgsql_transaction_commit_s,
+		.transaction_rollback = driver_pgsql_transaction_rollback,
+
+		.update = driver_pgsql_update,
+
+		.escape_blob = driver_pgsql_escape_blob,
+	}
+};
+
+const struct sql_result driver_pgsql_result = {
+	.v = {
+		.free = driver_pgsql_result_free,
+		.next_row = driver_pgsql_result_next_row,
+		.get_fields_count = driver_pgsql_result_get_fields_count,
+		.get_field_name = driver_pgsql_result_get_field_name,
+		.find_field = driver_pgsql_result_find_field,
+		.get_field_value = driver_pgsql_result_get_field_value,
+		.get_field_value_binary = driver_pgsql_result_get_field_value_binary,
+		.find_field_value = driver_pgsql_result_find_field_value,
+		.get_values = driver_pgsql_result_get_values,
+		.get_error = driver_pgsql_result_get_error,
+	}
+};
+
+const char *driver_pgsql_version = DOVECOT_ABI_VERSION;
+
+void driver_pgsql_init(void);
+void driver_pgsql_deinit(void);
+
+void driver_pgsql_init(void)
+{
+	sql_driver_register(&driver_pgsql_db);
+}
+
+void driver_pgsql_deinit(void)
+{
+	sql_driver_unregister(&driver_pgsql_db);
+}
+
+#endif