/*
* cmd_escapestring: certain strings sent to a database should be properly
* escaped -- for instance, quotes need to be escaped to insure that
* a query string is properly formatted. cmd_escapestring does whatever
* is necessary to escape the special characters in a string.
*
* Inputs:
* cmd->argv[0]: connection name
* cmd->argv[1]: string to escape
*
* Returns:
* this command CANNOT fail. The return string is null-terminated and
* stored in the data field of the modret_t structure.
*
* Notes:
* Different languages may escape different characters in different ways.
* A backend should handle this correctly, where possible. If there is
* no client library function to do the string conversion, it is strongly
* recommended that the backend module writer do whatever is necessry (read
* the database documentation and figure it out) to do the conversion
* themselves in this function.
*
* A backend MUST supply a working escapestring implementation. Simply
* copying the data from argv[0] into the data field of the modret allows
* for possible SQL injection attacks when this backend is used.
*/
MODRET cmd_escapestring(cmd_rec * cmd) {
conn_entry_t *entry = NULL;
db_conn_t *conn = NULL;
modret_t *cmr = NULL;
char *unescaped = NULL;
char *escaped = NULL;
cmd_rec *close_cmd;
size_t unescaped_len = 0;
#ifdef HAVE_POSTGRES_PQESCAPESTRINGCONN
int pgerr = 0;
#endif
sql_log(DEBUG_FUNC, "%s", "entering \tpostgres cmd_escapestring");
_sql_check_cmd(cmd, "cmd_escapestring");
if (cmd->argc != 2) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_escapestring");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "badly formed request");
}
/* get the named connection */
entry = _sql_get_connection(cmd->argv[0]);
if (!entry) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_escapestring");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION,
"unknown named connection");
}
conn = (db_conn_t *) entry->data;
/* Make sure the connection is open. */
cmr = cmd_open(cmd);
if (MODRET_ERROR(cmr)) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_escapestring");
return cmr;
}
unescaped = cmd->argv[1];
unescaped_len = strlen(unescaped);
escaped = (char *) pcalloc(cmd->tmp_pool, sizeof(char) *
(unescaped_len * 2) + 1);
#ifdef HAVE_POSTGRES_PQESCAPESTRINGCONN
PQescapeStringConn(conn->postgres, escaped, unescaped, unescaped_len, &pgerr);
if (pgerr != 0) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_escapestring");
return _build_error(cmd, conn);
}
#else
PQescapeString(escaped, unescaped, unescaped_len);
#endif
close_cmd = _sql_make_cmd(cmd->tmp_pool, 1, entry->name);
cmd_close(close_cmd);
SQL_FREE_CMD(close_cmd);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_escapestring");
return mod_create_data(cmd, (void *) escaped);
}
/*
* cmd_insert: executes an INSERT query, properly constructing the query
* based on the inputs.
*
* cmd_insert takes either exactly two inputs, or exactly four. If only
* two inputs are given, the second is a monolithic query string. See
* the examples below.
*
* Inputs:
* cmd->argv[0]: connection name
* cmd->argv[1]: table
* cmd->argv[2]: field string
* cmd->argv[3]: value string
*
* Returns:
* either a properly filled error modret_t if the insert failed, or a
* simple non-error modret_t.
*
* Example:
* These are example queries that would be executed for Postgres; other
* backends will have different SQL syntax.
*
* argv[] = "default","log","userid, date, count", "'aah', now(), 2"
* query = "INSERT INTO log (userid, date, count) VALUES ('aah', now(), 2)"
*
* argv[] = "default"," INTO foo VALUES ('do','re','mi','fa')"
* query = "INSERT INTO foo VALUES ('do','re','mi','fa')"
*
* Notes:
* none
*/
MODRET cmd_insert(cmd_rec *cmd) {
conn_entry_t *entry = NULL;
db_conn_t *conn = NULL;
modret_t *cmr = NULL;
modret_t *dmr = NULL;
char *query = NULL;
cmd_rec *close_cmd;
sql_log(DEBUG_FUNC, "%s", "entering \tpostgres cmd_insert");
_sql_check_cmd(cmd, "cmd_insert");
if ((cmd->argc != 2) && (cmd->argc != 4)) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_insert");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "badly formed request");
}
/* get the named connection */
entry = _sql_get_connection(cmd->argv[0]);
if (!entry) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_insert");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION,
"unknown named connection");
}
conn = (db_conn_t *) entry->data;
cmr = cmd_open(cmd);
if (MODRET_ERROR(cmr)) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_insert");
return cmr;
}
/* construct the query string */
if (cmd->argc == 2) {
query = pstrcat(cmd->tmp_pool, "INSERT ", cmd->argv[1], NULL);
} else {
query = pstrcat( cmd->tmp_pool, "INSERT INTO ", cmd->argv[1], " (",
cmd->argv[2], ") VALUES (", cmd->argv[3], ")",
NULL );
}
/* log the query string */
sql_log(DEBUG_INFO, "query \"%s\"", query);
/* perform the query. if it doesn't work, log the error, close the
* connection then return the error from the query processing.
*/
if (!(conn->result = PQexec(conn->postgres, query)) ||
(PQresultStatus(conn->result) != PGRES_COMMAND_OK)) {
dmr = _build_error( cmd, conn );
if (conn->result) PQclear(conn->result);
close_cmd = _sql_make_cmd( cmd->tmp_pool, 1, entry->name );
cmd_close(close_cmd);
SQL_FREE_CMD(close_cmd);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_insert");
return dmr;
}
PQclear(conn->result);
/* close the connection and return HANDLED. */
close_cmd = _sql_make_cmd( cmd->tmp_pool, 1, entry->name );
cmd_close(close_cmd);
SQL_FREE_CMD(close_cmd);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_insert");
return PR_HANDLED(cmd);
}
/*
* cmd_select: executes a SELECT query. properly constructing the query
* based on the inputs. See mod_sql.h for the definition of the _sql_data
* structure which is used to return the result data.
*
* cmd_select takes either exactly two inputs, or more than two. If only
* two inputs are given, the second is a monolithic query string. See
* the examples below.
*
* Inputs:
* cmd->argv[0]: connection name
* cmd->argv[1]: table
* cmd->argv[2]: select string
* Optional:
* cmd->argv[3]: where clause
* cmd->argv[4]: requested number of return rows (LIMIT)
*
* etc. : other options, such as "GROUP BY", "ORDER BY",
* and "DISTINCT" will start at cmd->arg[5]. All
* backends MUST support 'DISTINCT', the other
* arguments are optional (but encouraged).
*
* Returns:
* either a properly filled error modret_t if the select failed, or a
* modret_t with the result data filled in.
*
* Example:
* These are example queries that would be executed for Postgres; other
* backends will have different SQL syntax.
*
* argv[] = "default","user","userid, count", "userid='aah'","2"
* query = "SELECT userid, count FROM user WHERE userid='aah' LIMIT 2"
*
* argv[] = "default","usr1, usr2","usr1.foo, usr2.bar"
* query = "SELECT usr1.foo, usr2.bar FROM usr1, usr2"
*
* argv[] = "default","usr1","foo",,,"DISTINCT"
* query = "SELECT DISTINCT foo FROM usr1"
*
* argv[] = "default","bar FROM usr1 WHERE tmp=1 ORDER BY bar"
* query = "SELECT bar FROM usr1 WHERE tmp=1 ORDER BY bar"
*
* Notes:
* certain selects could return huge amounts of data. do whatever is
* possible to minimize the amount of data copying here.
*/
MODRET cmd_select(cmd_rec *cmd) {
conn_entry_t *entry = NULL;
db_conn_t *conn = NULL;
modret_t *cmr = NULL;
modret_t *dmr = NULL;
char *query = NULL;
int cnt = 0;
cmd_rec *close_cmd;
sql_log(DEBUG_FUNC, "%s", "entering \tpostgres cmd_select");
_sql_check_cmd(cmd, "cmd_select");
if (cmd->argc < 2) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_select");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "badly formed request");
}
/* get the named connection */
entry = _sql_get_connection(cmd->argv[0]);
if (!entry) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_select");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION,
"unknown named connection");
}
conn = (db_conn_t *) entry->data;
cmr = cmd_open(cmd);
if (MODRET_ERROR(cmr)) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_select");
return cmr;
}
/* construct the query string */
if (cmd->argc == 2) {
query = pstrcat(cmd->tmp_pool, "SELECT ", cmd->argv[1], NULL);
} else {
query = pstrcat( cmd->tmp_pool, cmd->argv[2], " FROM ",
cmd->argv[1], NULL );
if ((cmd->argc > 3) && (cmd->argv[3]))
query = pstrcat( cmd->tmp_pool, query, " WHERE ", cmd->argv[3], NULL );
if ((cmd->argc > 4) && (cmd->argv[4]))
query = pstrcat( cmd->tmp_pool, query, " LIMIT ", cmd->argv[4], NULL );
if (cmd->argc > 5) {
/* handle the optional arguments -- they're rare, so in this case
* we'll play with the already constructed query string, but in
* general we should probably take optional arguments into account
* and put the query string together later once we know what they are.
*/
for (cnt=5; cnt < cmd->argc; cnt++) {
if ((cmd->argv[cnt]) && !strcasecmp("DISTINCT",cmd->argv[cnt])) {
query = pstrcat( cmd->tmp_pool, "DISTINCT ", query, NULL);
}
}
}
query = pstrcat( cmd->tmp_pool, "SELECT ", query, NULL);
}
/* log the query string */
sql_log(DEBUG_INFO, "query \"%s\"", query);
/* perform the query. if it doesn't work, log the error, close the
* connection then return the error from the query processing.
*/
if (!(conn->result = PQexec(conn->postgres, query)) ||
(PQresultStatus(conn->result) != PGRES_TUPLES_OK)) {
dmr = _build_error( cmd, conn );
if (conn->result) PQclear(conn->result);
close_cmd = _sql_make_cmd( cmd->tmp_pool, 1, entry->name );
cmd_close(close_cmd);
SQL_FREE_CMD(close_cmd);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_select");
return dmr;
}
/* get the data. if it doesn't work, log the error, close the
* connection then return the error from the data processing.
*/
dmr = _build_data( cmd, conn );
PQclear(conn->result);
if (MODRET_ERROR(dmr)) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_select");
close_cmd = _sql_make_cmd( cmd->tmp_pool, 1, entry->name );
cmd_close(close_cmd);
SQL_FREE_CMD(close_cmd);
return dmr;
}
/* close the connection, return the data. */
close_cmd = _sql_make_cmd( cmd->tmp_pool, 1, entry->name );
cmd_close(close_cmd);
SQL_FREE_CMD(close_cmd);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_select");
return dmr;
}
/*
* cmd_open: attempts to open a named connection to the database.
*
* Inputs:
* cmd->argv[0]: connection name
*
* Returns:
* either a properly filled error modret_t if a connection could not be
* opened, or a simple non-error modret_t.
*
* Notes:
* mod_sql depends on these semantics -- a backend should not open
* a connection unless mod_sql requests it, nor close one unless
* mod_sql requests it. Connection counting is *REQUIRED* for complete
* compatibility; a connection should not be closed unless the count
* reaches 0, and ideally will not need to be re-opened for counts > 1.
*/
MODRET cmd_open(cmd_rec *cmd) {
conn_entry_t *entry = NULL;
db_conn_t *conn = NULL;
const char *server_version = NULL;
sql_log(DEBUG_FUNC, "%s", "entering \tpostgres cmd_open");
_sql_check_cmd(cmd, "cmd_open" );
if (cmd->argc < 1) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "badly formed request");
}
/* get the named connection */
if (!(entry = _sql_get_connection(cmd->argv[0]))) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION,
"unknown named connection");
}
conn = (db_conn_t *) entry->data;
/* if we're already open (connections > 0) increment connections
* reset our timer if we have one, and return HANDLED
*/
if (entry->connections > 0) {
if (PQstatus(conn->postgres) == CONNECTION_OK) {
entry->connections++;
if (entry->timer) {
pr_timer_reset(entry->timer, &sql_postgres_module);
}
sql_log(DEBUG_INFO, "connection '%s' count is now %d", entry->name,
entry->connections);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return PR_HANDLED(cmd);
} else {
char *reason;
size_t reason_len;
/* Unless we've been told not to reconnect, try to reconnect now.
* We only try once; if it fails, we return an error.
*/
if (!(pr_sql_opts & SQL_OPT_NO_RECONNECT)) {
PQreset(conn->postgres);
if (PQstatus(conn->postgres) == CONNECTION_OK) {
entry->connections++;
if (entry->timer) {
pr_timer_reset(entry->timer, &sql_postgres_module);
}
sql_log(DEBUG_INFO, "connection '%s' count is now %d", entry->name,
entry->connections);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return PR_HANDLED(cmd);
}
}
reason = PQerrorMessage(conn->postgres);
reason_len = strlen(reason);
/* Postgres might give us an empty string as the reason; not helpful. */
if (reason_len == 0) {
reason = "(unknown)";
reason_len = strlen(reason);
}
/* The error message returned by Postgres is usually appended with
* a newline. Let's prettify it by removing the newline. Note
* that yes, we are overwriting the pointer given to us by Postgres,
* but it's OK. The Postgres docs say that we're not supposed to
* free the memory associated with the returned string anyway.
*/
reason = pstrdup(session.pool, reason);
if (reason[reason_len-1] == '\n') {
reason[reason_len-1] = '\0';
reason_len--;
}
sql_log(DEBUG_INFO, "lost connection to database: %s", reason);
entry->connections = 0;
if (entry->timer) {
pr_timer_remove(entry->timer, &sql_postgres_module);
entry->timer = 0;
}
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION,
"lost connection to database");
}
}
/* make sure we have a new conn struct */
conn->postgres = PQconnectdb(conn->connectstring);
if (PQstatus(conn->postgres) == CONNECTION_BAD) {
/* if it didn't work, return an error */
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return _build_error( cmd, conn );
}
#if defined(PG_VERSION_STR)
sql_log(DEBUG_FUNC, "Postgres client: %s", PG_VERSION_STR);
#endif
server_version = PQparameterStatus(conn->postgres, "server_version");
if (server_version != NULL) {
sql_log(DEBUG_FUNC, "Postgres server version: %s", server_version);
}
#ifdef PR_USE_NLS
if (pr_encode_get_encoding() != NULL) {
const char *encoding;
encoding = get_postgres_encoding(pr_encode_get_encoding());
/* Configure the connection for the current local character set. */
if (PQsetClientEncoding(conn->postgres, encoding) < 0) {
/* if it didn't work, return an error */
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return _build_error(cmd, conn);
}
sql_log(DEBUG_FUNC, "Postgres connection character set now '%s' "
"(from '%s')", pg_encoding_to_char(PQclientEncoding(conn->postgres)),
pr_encode_get_encoding());
}
#endif /* !PR_USE_NLS */
/* bump connections */
entry->connections++;
if (pr_sql_conn_policy == SQL_CONN_POLICY_PERSESSION) {
/* If the connection policy is PERSESSION... */
if (entry->connections == 1) {
/* ...and we are actually opening the first connection to the database;
* we want to make sure this connection stays open, after this first use
* (as per Bug#3290). To do this, we re-bump the connection count.
*/
entry->connections++;
}
} else if (entry->ttl > 0) {
/* Set up our timer if necessary */
entry->timer = pr_timer_add(entry->ttl, -1, &sql_postgres_module,
sql_timer_cb, "postgres connection ttl");
sql_log(DEBUG_INFO, "connection '%s' - %d second timer started",
entry->name, entry->ttl);
/* Timed connections get re-bumped so they don't go away when cmd_close
* is called.
*/
entry->connections++;
}
/* return HANDLED */
sql_log(DEBUG_INFO, "connection '%s' opened", entry->name);
sql_log(DEBUG_INFO, "connection '%s' count is now %d", entry->name,
entry->connections);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return PR_HANDLED(cmd);
}
/*
* cmd_query: executes a freeform query string, with no syntax checking.
*
* cmd_query takes exactly two inputs, the connection and the query string.
*
* Inputs:
* cmd->argv[0]: connection name
* cmd->argv[1]: query string
*
* Returns:
* depending on the query type, returns a modret_t with data, a non-error
* modret_t, or a properly filled error modret_t if the query failed.
*
* Example:
* None. The query should be passed directly to the backend database.
*
* Notes:
* None.
*/
MODRET cmd_query(cmd_rec *cmd) {
conn_entry_t *entry = NULL;
db_conn_t *conn = NULL;
modret_t *cmr = NULL;
modret_t *dmr = NULL;
char *query = NULL;
cmd_rec *close_cmd;
sql_log(DEBUG_FUNC, "%s", "entering \tpostgres cmd_query");
_sql_check_cmd(cmd, "cmd_query");
if (cmd->argc != 2) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_query");
return ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "badly formed request");
}
/* get the named connection */
entry = _sql_get_connection(cmd->argv[0]);
if (!entry) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_query");
return ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "unknown named connection");
}
conn = (db_conn_t *) entry->data;
cmr = cmd_open(cmd);
if (MODRET_ERROR(cmr)) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_query");
return cmr;
}
query = pstrcat(cmd->tmp_pool, cmd->argv[1], NULL);
/* log the query string */
sql_log( DEBUG_INFO, "query \"%s\"", query);
/* perform the query. if it doesn't work, log the error, close the
* connection then return the error from the query processing.
*/
if (!(conn->result = PQexec(conn->postgres, query)) ||
((PQresultStatus(conn->result) != PGRES_TUPLES_OK) &&
(PQresultStatus(conn->result) != PGRES_COMMAND_OK))) {
dmr = _build_error( cmd, conn );
if (conn->result) PQclear(conn->result);
close_cmd = _sql_make_cmd( cmd->tmp_pool, 1, entry->name );
cmd_close(close_cmd);
SQL_FREE_CMD(close_cmd);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_select");
return dmr;
}
/* get data if necessary. if it doesn't work, log the error, close the
* connection then return the error from the data processing.
*/
if ( PQresultStatus( conn->result ) == PGRES_TUPLES_OK ) {
dmr = _build_data( cmd, conn );
PQclear(conn->result);
if (MODRET_ERROR(dmr)) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_query");
}
} else {
dmr = HANDLED(cmd);
}
/* close the connection, return the data. */
close_cmd = _sql_make_cmd( cmd->tmp_pool, 1, entry->name );
cmd_close(close_cmd);
SQL_FREE_CMD(close_cmd);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_query");
return dmr;
}
/*
* cmd_open: attempts to open a named connection to the database.
*
* Inputs:
* cmd->argv[0]: connection name
*
* Returns:
* either a properly filled error modret_t if a connection could not be
* opened, or a simple non-error modret_t.
*
* Notes:
* mod_sql depends on these semantics -- a backend should not open
* a connection unless mod_sql requests it, nor close one unless
* mod_sql requests it. Connection counting is *REQUIRED* for complete
* compatibility; a connection should not be closed unless the count
* reaches 0, and ideally will not need to be re-opened for counts > 1.
*/
MODRET cmd_open(cmd_rec *cmd) {
conn_entry_t *entry = NULL;
db_conn_t *conn = NULL;
sql_log(DEBUG_FUNC, "%s", "entering \tpostgres cmd_open");
_sql_check_cmd(cmd, "cmd_open" );
if (cmd->argc < 1) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "badly formed request");
}
/* get the named connection */
if (!(entry = _sql_get_connection(cmd->argv[0]))) {
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "unknown named connection");
}
conn = (db_conn_t *) entry->data;
/* if we're already open (connections > 0) increment connections
* reset our timer if we have one, and return HANDLED
*/
if ((entry->connections > 0) &&
(PQstatus(conn->postgres) == CONNECTION_OK)) {
entry->connections++;
if (entry->timer)
pr_timer_reset(entry->timer, &sql_postgres_module);
sql_log(DEBUG_INFO, "connection '%s' count is now %d", entry->name,
entry->connections);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return HANDLED(cmd);
}
/* make sure we have a new conn struct */
conn->postgres = PQconnectdb(conn->connectstring);
if (PQstatus(conn->postgres) == CONNECTION_BAD) {
/* if it didn't work, return an error */
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return _build_error( cmd, conn );
}
/* bump connections */
entry->connections++;
/* set up our timer if necessary */
if (entry->ttl > 0) {
entry->timer = pr_timer_add(entry->ttl, -1, &sql_postgres_module,
_sql_timer_callback);
sql_log(DEBUG_INFO, "connection '%s' - %d second timer started",
entry->name, entry->ttl);
/* timed connections get re-bumped so they don't go away when cmd_close
* is called.
*/
entry->connections++;
}
/* return HANDLED */
sql_log(DEBUG_INFO, "connection '%s' opened", entry->name);
sql_log(DEBUG_INFO, "connection '%s' count is now %d", entry->name,
entry->connections);
sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_open");
return HANDLED(cmd);
}
