Example #1
0
/*
 * cmd_checkauth: some backend databases may provide backend-specific
 *  methods to check passwords.  This function takes a cleartext password
 *  and a hashed password and checks to see if they are the same.
 *
 * Inputs:
 *  cmd->argv[0]: connection name
 *  cmd->argv[1]: cleartext string
 *  cmd->argv[2]: hashed string
 *
 * Returns:
 *  PR_HANDLED(cmd)                        -- passwords match
 *  PR_ERROR_INT(cmd, PR_AUTH_NOPWD)       -- missing password
 *  PR_ERROR_INT(cmd, PR_AUTH_BADPWD)      -- passwords don't match
 *  PR_ERROR_INT(cmd, PR_AUTH_DISABLEPWD)  -- password is disabled
 *  PR_ERROR_INT(cmd, PR_AUTH_AGEPWD)      -- password is aged
 *  PR_ERROR(cmd)                          -- unknown error
 *
 * Notes:
 *  If this backend does not provide this functionality, this cmd *must*
 *  return ERROR.
 */
MODRET cmd_checkauth(cmd_rec * cmd) {
  conn_entry_t *entry = NULL;
  db_conn_t *conn = NULL;

  sql_log(DEBUG_FUNC, "%s", "entering \tpostgres cmd_checkauth");

  _sql_check_cmd(cmd, "cmd_checkauth");

  if (cmd->argc != 3) {
    sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_checkauth");
    return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION, "badly formed request");
  }

  /* get the named connection -- not used in this case, but for consistency */
  entry = _sql_get_connection(cmd->argv[0]);
  if (!entry) {
    sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_checkauth");
    return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION,
      "unknown named connection");
  }

  conn = (db_conn_t *) entry->data;

  sql_log(DEBUG_WARN, MOD_SQL_POSTGRES_VERSION
    ": Postgres does not support the 'Backend' SQLAuthType");

  sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_checkauth");

  /* PostgreSQL doesn't provide this functionality */
  return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION,
    "Postgres does not support the 'Backend' SQLAuthType");
}
Example #2
0
/*
 * 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);
}
Example #3
0
/*
 * cmd_close: attempts to close the named connection.
 *
 * Inputs:
 *  cmd->argv[0]: connection name
 * Optional:
 *  cmd->argv[1]: close immediately
 *
 * Returns:
 *  either a properly filled error modret_t if a connection could not be
 *  closed, or a simple non-error modret_t.  For the case of mod_sql_postgres,
 *  there are no error codes returned by the close call; other backends
 *  may be able to return a useful error message.
 *
 * 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 should not need to be re-opened for counts > 1.
 * 
 *  If argv[1] exists and is not NULL, the connection should be immediately
 *  closed and the connection count should be reset to 0.
 */
MODRET cmd_close(cmd_rec *cmd) {
  conn_entry_t *entry = NULL;
  db_conn_t *conn = NULL;

  sql_log(DEBUG_FUNC, "%s", "entering \tpostgres cmd_close");

  _sql_check_cmd(cmd, "cmd_close");

  if ((cmd->argc < 1) || (cmd->argc > 2)) {
    sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_close");
    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_close");
    return PR_ERROR_MSG(cmd, MOD_SQL_POSTGRES_VERSION,
      "unknown named connection");
  }

  conn = (db_conn_t *) entry->data;

  /* if we're closed already (connections == 0) return HANDLED */
  if (entry->connections == 0) {
    sql_log(DEBUG_INFO, "connection '%s' count is now %d", entry->name,
      entry->connections);

    sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_close");
    return PR_HANDLED(cmd);
  }

  /* decrement connections. If our count is 0 or we received a second arg
   * close the connection, explicitly set the counter to 0, and remove any
   * timers.
   */
  if (((--entry->connections) == 0 ) || ((cmd->argc == 2) && (cmd->argv[1]))) {
    PQfinish(conn->postgres);
    conn->postgres = NULL;
    entry->connections = 0;

    if (entry->timer) {
      pr_timer_remove(entry->timer, &sql_postgres_module);
      entry->timer = 0;
      sql_log(DEBUG_INFO, "connection '%s' - timer stopped", entry->name);
    }

    sql_log(DEBUG_INFO, "connection '%s' closed", entry->name);
  }

  sql_log(DEBUG_INFO, "connection '%s' count is now %d", entry->name,
    entry->connections);
  sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_close");
  
  return PR_HANDLED(cmd);
}
Example #4
0
/* 
 * _sql_add_connection: internal helper function to maintain a cache of 
 *  connections.  Since we expect the number of named connections to
 *  be small, simply use an array header to hold them.  We don't allow 
 *  duplicate connection names.
 *
 * Returns: NULL if the insertion was unsuccessful, a pointer to the 
 *  conn_entry_t that was created if successful.
 */
static void *_sql_add_connection(pool *p, char *name, db_conn_t *conn)
{
  conn_entry_t *entry = NULL;

  if ((!name) || (!conn) || (!p)) return NULL;
  
  if (_sql_get_connection(name)) {
    /* duplicated name */
    return NULL;
  }

  entry = (conn_entry_t *) pcalloc(p, sizeof(conn_entry_t));
  entry->name = name;
  entry->data = conn;

  *((conn_entry_t **) push_array(conn_cache)) = entry;

  return entry;
}
Example #5
0
/*
 * 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;
  char *unescaped = NULL;
  char *escaped = NULL;

  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;

  /* Note: the PQescapeString() function appeared in the C API as of
   * Postgres-7.2.
   */
  unescaped = cmd->argv[1];
  escaped = (char *) pcalloc(cmd->tmp_pool, sizeof(char) *
    (strlen(unescaped) * 2) + 1);

  PQescapeString(escaped, unescaped, strlen(unescaped));

  sql_log(DEBUG_FUNC, "%s", "exiting \tpostgres cmd_escapestring");
  return mod_create_data(cmd, (void *) escaped);
}
Example #6
0
/*
 * 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);
}
Example #7
0
/*
 * 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;
}
Example #8
0
/*
 * 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);
}