res_config_pgsql.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2017, Digium, Inc.
 *
 * Manuel Guesdon <[email protected]> - PostgreSQL RealTime Driver Author/Adaptor
 * Mark Spencer <[email protected]>  - Asterisk Author
 * Matthew Boehm <[email protected]> - MySQL RealTime Driver Author
 *
 * res_config_pgsql.c <PostgreSQL plugin for RealTime configuration engine>
 *
 * v1.0   - (07-11-05) - Initial version based on res_config_mysql v2.0
 */

/*! \file
 *
 * \brief PostgreSQL plugin for Asterisk RealTime Architecture
 *
 * \author Mark Spencer <[email protected]>
 * \author Manuel Guesdon <[email protected]> - PostgreSQL RealTime Driver Author/Adaptor
 *
 * PostgreSQL http://www.postgresql.org
 */

/*** MODULEINFO
   <depend>pgsql</depend>
   <support_level>extended</support_level>
 ***/

#include "asterisk.h"

#include <libpq-fe.h>         /* PostgreSQL */

#include "asterisk/file.h"
#include "asterisk/channel.h"
#include "asterisk/pbx.h"
#include "asterisk/config.h"
#include "asterisk/module.h"
#include "asterisk/lock.h"
#include "asterisk/utils.h"
#include "asterisk/cli.h"

AST_MUTEX_DEFINE_STATIC(pgsql_lock);
AST_THREADSTORAGE(sql_buf);
AST_THREADSTORAGE(findtable_buf);
AST_THREADSTORAGE(where_buf);
AST_THREADSTORAGE(escapebuf_buf);
AST_THREADSTORAGE(semibuf_buf);

#define RES_CONFIG_PGSQL_CONF "res_pgsql.conf"

static PGconn *pgsqlConn = NULL;
static int version;
#define has_schema_support (version > 70300 ? 1 : 0)
#define USE_BACKSLASH_AS_STRING  (version >= 90100 ? 1 : 0)

#define MAX_DB_OPTION_SIZE 64

struct columns {
   char *name;
   char *type;
   int len;
   unsigned int notnull:1;
   unsigned int hasdefault:1;
   AST_LIST_ENTRY(columns) list;
};

struct tables {
   ast_rwlock_t lock;
   AST_LIST_HEAD_NOLOCK(psql_columns, columns) columns;
   AST_LIST_ENTRY(tables) list;
   char name[0];
};

static AST_LIST_HEAD_STATIC(psql_tables, tables);

static char dbhost[MAX_DB_OPTION_SIZE] = "";
static char dbuser[MAX_DB_OPTION_SIZE] = "";
static char dbpass[MAX_DB_OPTION_SIZE] = "";
static char dbname[MAX_DB_OPTION_SIZE] = "";
static char dbappname[MAX_DB_OPTION_SIZE] = "";
static char dbsock[MAX_DB_OPTION_SIZE] = "";
static int dbport = 5432;
static time_t connect_time = 0;

static int parse_config(int reload);
static int pgsql_reconnect(const char *database);
static char *handle_cli_realtime_pgsql_status(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
static char *handle_cli_realtime_pgsql_cache(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);

static enum { RQ_WARN, RQ_CREATECLOSE, RQ_CREATECHAR } requirements;

static struct ast_cli_entry cli_realtime[] = {
   AST_CLI_DEFINE(handle_cli_realtime_pgsql_status, "Shows connection information for the PostgreSQL RealTime driver"),
   AST_CLI_DEFINE(handle_cli_realtime_pgsql_cache, "Shows cached tables within the PostgreSQL realtime driver"),
};

#define ESCAPE_STRING(buffer, stringname) \
   do { \
      int len = strlen(stringname); \
      struct ast_str *semi = ast_str_thread_get(&semibuf_buf, len * 3 + 1); \
      const char *chunk = stringname; \
      ast_str_reset(semi); \
      for (; *chunk; chunk++) { \
         if (strchr(";^", *chunk)) { \
            ast_str_append(&semi, 0, "^%02hhX", *chunk); \
         } else { \
            ast_str_append(&semi, 0, "%c", *chunk); \
         } \
      } \
      if (ast_str_strlen(semi) > (ast_str_size(buffer) - 1) / 2) { \
         ast_str_make_space(&buffer, ast_str_strlen(semi) * 2 + 1); \
      } \
      PQescapeStringConn(pgsqlConn, ast_str_buffer(buffer), ast_str_buffer(semi), ast_str_size(buffer), &pgresult); \
   } while (0)

static void destroy_table(struct tables *table)
{
   struct columns *column;
   ast_rwlock_wrlock(&table->lock);
   while ((column = AST_LIST_REMOVE_HEAD(&table->columns, list))) {
      ast_free(column);
   }
   ast_rwlock_unlock(&table->lock);
   ast_rwlock_destroy(&table->lock);
   ast_free(table);
}

/*! \brief Helper function for pgsql_exec.  For running querys, use pgsql_exec()
 *
 *  Connect if not currently connected.  Run the given query.
 *
 *  \param database   database name we are connected to (used for error logging)
 *  \param tablename  table  name we are connected to (used for error logging)
 *  \param sql        sql query string to execute
 *  \param result     pointer for where to store the result handle
 *
 *  \return -1 on fatal query error
 *  \return -2 on query failure that resulted in disconnection
 *  \return 0 on success
 *
 *  \note see pgsql_exec for full example
 */
static int _pgsql_exec(const char *database, const char *tablename, const char *sql, PGresult **result)
{
   ExecStatusType result_status;

   if (!pgsqlConn) {
      ast_debug(1, "PostgreSQL connection not defined, connecting\n");

      if (pgsql_reconnect(database) != 1) {
         ast_log(LOG_NOTICE, "reconnect failed\n");
         *result = NULL;
         return -1;
      }

      ast_debug(1, "PostgreSQL connection successful\n");
   }

   *result = PQexec(pgsqlConn, sql);
   result_status = PQresultStatus(*result);
   if (result_status != PGRES_COMMAND_OK
      && result_status != PGRES_TUPLES_OK
      && result_status != PGRES_NONFATAL_ERROR) {

      ast_log(LOG_ERROR, "PostgreSQL RealTime: Failed to query '%s@%s'.\n", tablename, database);
      ast_log(LOG_ERROR, "PostgreSQL RealTime: Query Failed: %s\n", sql);
      ast_log(LOG_ERROR, "PostgreSQL RealTime: Query Failed because: %s (%s)\n",
         PQresultErrorMessage(*result),
         PQresStatus(result_status));

      /* we may have tried to run a command on a disconnected/disconnecting handle */
      /* are we no longer connected to the database... if not try again */
      if (PQstatus(pgsqlConn) != CONNECTION_OK) {
         PQfinish(pgsqlConn);
         pgsqlConn = NULL;
         return -2;
      }

      /* connection still okay, which means the query is just plain bad */
      return -1;
   }

   ast_debug(1, "PostgreSQL query successful: %s\n", sql);
   return 0;
}

/*! \brief Do a postgres query, with reconnection support
 *
 *  Connect if not currently connected.  Run the given query
 *  and if we're disconnected afterwards, reconnect and query again.
 *
 *  \param database   database name we are connected to (used for error logging)
 *  \param tablename  table  name we are connected to (used for error logging)
 *  \param sql        sql query string to execute
 *  \param result     pointer for where to store the result handle
 *
 *  \return -1 on query failure
 *  \return 0 on success
 *
 *  \code
 * int i, rows;
 * PGresult *result;
 * char *field_name, *field_type, *field_len, *field_notnull, *field_default;
 *
 * pgsql_exec("db", "table", "SELECT 1", &result)
 *
 * rows = PQntuples(result);
 * for (i = 0; i < rows; i++) {
 *    field_name    = PQgetvalue(result, i, 0);
 *    field_type    = PQgetvalue(result, i, 1);
 *    field_len     = PQgetvalue(result, i, 2);
 *    field_notnull = PQgetvalue(result, i, 3);
 *    field_default = PQgetvalue(result, i, 4);
 * }
 *  \endcode
 */
static int pgsql_exec(const char *database, const char *tablename, const char *sql, PGresult **result)
{
   int attempts = 0;
   int res;

   /* Try the query, note failure if any */
   /* On first failure, reconnect and try again (_pgsql_exec handles reconnect) */
   /* On second failure, treat as fatal query error */

   while (attempts++ < 2) {
      ast_debug(1, "PostgreSQL query attempt %d\n", attempts);
      res = _pgsql_exec(database, tablename, sql, result);

      if (res == 0) {
         if (attempts > 1) {
            ast_log(LOG_NOTICE, "PostgreSQL RealTime: Query finally succeeded: %s\n", sql);
         }

         return 0;
      }

      if (res == -1) {
         return -1; /* Still connected to db, but could not process query (fatal error) */
      }

      /* res == -2 (query on a disconnected handle) */
      ast_debug(1, "PostgreSQL query attempt %d failed, trying again\n", attempts);
   }

   return -1;
}

static struct tables *find_table(const char *database, const char *orig_tablename)
{
   struct columns *column;
   struct tables *table;
   struct ast_str *sql = ast_str_thread_get(&findtable_buf, 330);
   RAII_VAR(PGresult *, result, NULL, PQclear);
   int exec_result;
   char *fname, *ftype, *flen, *fnotnull, *fdef;
   int i, rows;

   AST_LIST_LOCK(&psql_tables);
   AST_LIST_TRAVERSE(&psql_tables, table, list) {
      if (!strcasecmp(table->name, orig_tablename)) {
         ast_debug(1, "Found table in cache; now locking\n");
         ast_rwlock_rdlock(&table->lock);
         ast_debug(1, "Lock cached table; now returning\n");
         AST_LIST_UNLOCK(&psql_tables);
         return table;
      }
   }

   if (database == NULL) {
      AST_LIST_UNLOCK(&psql_tables);
      return NULL;
   }

   ast_debug(1, "Table '%s' not found in cache, querying now\n", orig_tablename);

   /* Not found, scan the table */
   if (has_schema_support) {
      char *schemaname, *tablename, *tmp_schemaname, *tmp_tablename;
      if (strchr(orig_tablename, '.')) {
         tmp_schemaname = ast_strdupa(orig_tablename);
         tmp_tablename = strchr(tmp_schemaname, '.');
         *tmp_tablename++ = '\0';
      } else {
         tmp_schemaname = "";
         tmp_tablename = ast_strdupa(orig_tablename);
      }

      tablename = ast_alloca(strlen(tmp_tablename) * 2 + 1);
      PQescapeStringConn(pgsqlConn, tablename, tmp_tablename, strlen(tmp_tablename), NULL);
      schemaname = ast_alloca(strlen(tmp_schemaname) * 2 + 1);
      PQescapeStringConn(pgsqlConn, schemaname, tmp_schemaname, strlen(tmp_schemaname), NULL);

      ast_str_set(&sql, 0, "SELECT a.attname, t.typname, a.attlen, a.attnotnull, pg_catalog.pg_get_expr(d.adbin, d.adrelid) adsrc, a.atttypmod FROM (((pg_catalog.pg_class c INNER JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace AND c.relname = '%s' AND n.nspname = %s%s%s) INNER JOIN pg_catalog.pg_attribute a ON (NOT a.attisdropped) AND a.attnum > 0 AND a.attrelid = c.oid) INNER JOIN pg_catalog.pg_type t ON t.oid = a.atttypid) LEFT OUTER JOIN pg_attrdef d ON a.atthasdef AND d.adrelid = a.attrelid AND d.adnum = a.attnum ORDER BY n.nspname, c.relname, attnum",
         tablename,
         ast_strlen_zero(schemaname) ? "" : "'", ast_strlen_zero(schemaname) ? "current_schema()" : schemaname, ast_strlen_zero(schemaname) ? "" : "'");
   } else {
      char *tablename;
      tablename = ast_alloca(strlen(orig_tablename) * 2 + 1);
      PQescapeStringConn(pgsqlConn, tablename, orig_tablename, strlen(orig_tablename), NULL);

      ast_str_set(&sql, 0, "SELECT a.attname, t.typname, a.attlen, a.attnotnull, d.adsrc, a.atttypmod FROM pg_class c, pg_type t, pg_attribute a LEFT OUTER JOIN pg_attrdef d ON a.atthasdef AND d.adrelid = a.attrelid AND d.adnum = a.attnum WHERE c.oid = a.attrelid AND a.atttypid = t.oid AND (a.attnum > 0) AND c.relname = '%s' ORDER BY c.relname, attnum", tablename);
   }

   ast_mutex_lock(&pgsql_lock);
   exec_result = pgsql_exec(database, orig_tablename, ast_str_buffer(sql), &result);
   ast_mutex_unlock(&pgsql_lock);
   ast_debug(1, "Query of table structure complete.  Now retrieving results.\n");
   if (exec_result != 0) {
      ast_log(LOG_ERROR, "Failed to query database columns for table %s\n", orig_tablename);
      AST_LIST_UNLOCK(&psql_tables);
      return NULL;
   }

   if (!(table = ast_calloc(1, sizeof(*table) + strlen(orig_tablename) + 1))) {
      ast_log(LOG_ERROR, "Unable to allocate memory for new table structure\n");
      AST_LIST_UNLOCK(&psql_tables);
      return NULL;
   }
   strcpy(table->name, orig_tablename); /* SAFE */
   ast_rwlock_init(&table->lock);
   AST_LIST_HEAD_INIT_NOLOCK(&table->columns);

   rows = PQntuples(result);
   for (i = 0; i < rows; i++) {
      fname = PQgetvalue(result, i, 0);
      ftype = PQgetvalue(result, i, 1);
      flen = PQgetvalue(result, i, 2);
      fnotnull = PQgetvalue(result, i, 3);
      fdef = PQgetvalue(result, i, 4);
      ast_verb(4, "Found column '%s' of type '%s'\n", fname, ftype);

      if (!(column = ast_calloc(1, sizeof(*column) + strlen(fname) + strlen(ftype) + 2))) {
         ast_log(LOG_ERROR, "Unable to allocate column element for %s, %s\n", orig_tablename, fname);
         destroy_table(table);
         AST_LIST_UNLOCK(&psql_tables);
         return NULL;
      }

      if (strcmp(flen, "-1") == 0) {
         /* Some types, like chars, have the length stored in a different field */
         flen = PQgetvalue(result, i, 5);
         sscanf(flen, "%30d", &column->len);
         column->len -= 4;
      } else {
         sscanf(flen, "%30d", &column->len);
      }
      column->name = (char *)column + sizeof(*column);
      column->type = (char *)column + sizeof(*column) + strlen(fname) + 1;
      strcpy(column->name, fname);
      strcpy(column->type, ftype);
      if (*fnotnull == 't') {
         column->notnull = 1;
      } else {
         column->notnull = 0;
      }
      if (!ast_strlen_zero(fdef)) {
         column->hasdefault = 1;
      } else {
         column->hasdefault = 0;
      }
      AST_LIST_INSERT_TAIL(&table->columns, column, list);
   }

   AST_LIST_INSERT_TAIL(&psql_tables, table, list);
   ast_rwlock_rdlock(&table->lock);
   AST_LIST_UNLOCK(&psql_tables);
   return table;
}

#define release_table(table) ast_rwlock_unlock(&(table)->lock);

static struct columns *find_column(struct tables *t, const char *colname)
{
   struct columns *column;

   /* Check that the column exists in the table */
   AST_LIST_TRAVERSE(&t->columns, column, list) {
      if (strcmp(column->name, colname) == 0) {
         return column;
      }
   }
   return NULL;
}

#define IS_SQL_LIKE_CLAUSE(x) ((x) && ast_ends_with(x, " LIKE"))
#define ESCAPE_CLAUSE (USE_BACKSLASH_AS_STRING ? " ESCAPE '\\'" : " ESCAPE '\\\\'")

static struct ast_variable *realtime_pgsql(const char *database, const char *tablename, const struct ast_variable *fields)
{
   RAII_VAR(PGresult *, result, NULL, PQclear);
   int pgresult;
   struct ast_str *sql = ast_str_thread_get(&sql_buf, 100);
   struct ast_str *escapebuf = ast_str_thread_get(&escapebuf_buf, 100);
   char *stringp;
   char *chunk;
   char *op;
   char *escape = "";
   const struct ast_variable *field = fields;
   struct ast_variable *var = NULL, *prev = NULL;

   /*
    * Ignore database from the extconfig.conf since it was
    * configured by res_pgsql.conf.
    */
   database = dbname;

   if (!tablename) {
      ast_log(LOG_WARNING, "PostgreSQL RealTime: No table specified.\n");
      return NULL;
   }

   /*
    * Must connect to the server before anything else as ESCAPE_STRING()
    * uses pgsqlConn
    */
   ast_mutex_lock(&pgsql_lock);
   if (!pgsql_reconnect(database)) {
      ast_mutex_unlock(&pgsql_lock);
      return NULL;
   }

   /* Get the first parameter and first value in our list of passed paramater/value pairs */
   if (!field) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: Realtime retrieval requires at least 1 parameter and 1 value to search on.\n");
      if (pgsqlConn) {
         PQfinish(pgsqlConn);
         pgsqlConn = NULL;
      }
      ast_mutex_unlock(&pgsql_lock);
      return NULL;
   }

   /* Create the first part of the query using the first parameter/value pairs we just extracted
      If there is only 1 set, then we have our query. Otherwise, loop thru the list and concat */
   if (!strchr(field->name, ' ')) {
      op = " =";
   } else {
      op = "";
      if (IS_SQL_LIKE_CLAUSE(field->name)) {
         escape = ESCAPE_CLAUSE;
      }
   }

   ESCAPE_STRING(escapebuf, field->value);
   if (pgresult) {
      ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", field->value);
      ast_mutex_unlock(&pgsql_lock);
      return NULL;
   }

   ast_str_set(&sql, 0, "SELECT * FROM %s WHERE %s%s '%s'%s", tablename, field->name, op, ast_str_buffer(escapebuf), escape);
   while ((field = field->next)) {
      escape = "";
      if (!strchr(field->name, ' ')) {
         op = " =";
      } else {
         op = "";
         if (IS_SQL_LIKE_CLAUSE(field->name)) {
            escape = ESCAPE_CLAUSE;
         }
      }

      ESCAPE_STRING(escapebuf, field->value);
      if (pgresult) {
         ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", field->value);
         ast_mutex_unlock(&pgsql_lock);
         return NULL;
      }

      ast_str_append(&sql, 0, " AND %s%s '%s'%s", field->name, op, ast_str_buffer(escapebuf), escape);
   }
   ast_str_append(&sql, 0, " LIMIT 1");

   /* We now have our complete statement; Lets connect to the server and execute it. */
        if (pgsql_exec(database, tablename, ast_str_buffer(sql), &result) != 0) {
      ast_mutex_unlock(&pgsql_lock);
      return NULL;
        }

   ast_debug(1, "PostgreSQL RealTime: Result=%p Query: %s\n", result, ast_str_buffer(sql));

   if (PQntuples(result) > 0) {
      int i = 0;
      int numFields = PQnfields(result);
      char **fieldnames = NULL;

      ast_debug(1, "PostgreSQL RealTime: Found a row.\n");

      if (!(fieldnames = ast_calloc(1, numFields * sizeof(char *)))) {
         ast_mutex_unlock(&pgsql_lock);
         return NULL;
      }
      for (i = 0; i < numFields; i++)
         fieldnames[i] = PQfname(result, i);
      for (i = 0; i < numFields; i++) {
         stringp = PQgetvalue(result, 0, i);
         while (stringp) {
            chunk = strsep(&stringp, ";");
            if (chunk && !ast_strlen_zero(ast_realtime_decode_chunk(ast_strip(chunk)))) {
               if (prev) {
                  prev->next = ast_variable_new(fieldnames[i], chunk, "");
                  if (prev->next) {
                     prev = prev->next;
                  }
               } else {
                  prev = var = ast_variable_new(fieldnames[i], chunk, "");
               }
            }
         }
      }
      ast_free(fieldnames);
   } else {
      ast_debug(1, "Postgresql RealTime: Could not find any rows in table %s@%s.\n", tablename, database);
   }

   ast_mutex_unlock(&pgsql_lock);

   return var;
}

static struct ast_config *realtime_multi_pgsql(const char *database, const char *table, const struct ast_variable *fields)
{
   RAII_VAR(PGresult *, result, NULL, PQclear);
   int num_rows = 0, pgresult;
   struct ast_str *sql = ast_str_thread_get(&sql_buf, 100);
   struct ast_str *escapebuf = ast_str_thread_get(&escapebuf_buf, 100);
   const struct ast_variable *field = fields;
   const char *initfield = NULL;
   char *stringp;
   char *chunk;
   char *op;
   char *escape = "";
   struct ast_variable *var = NULL;
   struct ast_config *cfg = NULL;
   struct ast_category *cat = NULL;

   /*
    * Ignore database from the extconfig.conf since it was
    * configured by res_pgsql.conf.
    */
   database = dbname;

   if (!table) {
      ast_log(LOG_WARNING, "PostgreSQL RealTime: No table specified.\n");
      return NULL;
   }

   if (!(cfg = ast_config_new()))
      return NULL;

   /*
    * Must connect to the server before anything else as ESCAPE_STRING()
    * uses pgsqlConn
    */
   ast_mutex_lock(&pgsql_lock);
   if (!pgsql_reconnect(database)) {
      ast_mutex_unlock(&pgsql_lock);
      return NULL;
   }

   /* Get the first parameter and first value in our list of passed paramater/value pairs */
   if (!field) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: Realtime retrieval requires at least 1 parameter and 1 value to search on.\n");
      if (pgsqlConn) {
         PQfinish(pgsqlConn);
         pgsqlConn = NULL;
      }
      ast_mutex_unlock(&pgsql_lock);
      ast_config_destroy(cfg);
      return NULL;
   }

   initfield = ast_strdupa(field->name);
   if ((op = strchr(initfield, ' '))) {
      *op = '\0';
   }

   /* Create the first part of the query using the first parameter/value pairs we just extracted
      If there is only 1 set, then we have our query. Otherwise, loop thru the list and concat */

   if (!strchr(field->name, ' ')) {
      op = " =";
      escape = "";
   } else {
      op = "";
      if (IS_SQL_LIKE_CLAUSE(field->name)) {
         escape = ESCAPE_CLAUSE;
      }
   }

   ESCAPE_STRING(escapebuf, field->value);
   if (pgresult) {
      ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", field->value);
      ast_mutex_unlock(&pgsql_lock);
      ast_config_destroy(cfg);
      return NULL;
   }

   ast_str_set(&sql, 0, "SELECT * FROM %s WHERE %s%s '%s'%s", table, field->name, op, ast_str_buffer(escapebuf), escape);
   while ((field = field->next)) {
      escape = "";
      if (!strchr(field->name, ' ')) {
         op = " =";
         escape = "";
      } else {
         op = "";
         if (IS_SQL_LIKE_CLAUSE(field->name)) {
            escape = ESCAPE_CLAUSE;
         }
      }

      ESCAPE_STRING(escapebuf, field->value);
      if (pgresult) {
         ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", field->value);
         ast_mutex_unlock(&pgsql_lock);
         ast_config_destroy(cfg);
         return NULL;
      }

      ast_str_append(&sql, 0, " AND %s%s '%s'%s", field->name, op, ast_str_buffer(escapebuf), escape);
   }

   if (initfield) {
      ast_str_append(&sql, 0, " ORDER BY %s", initfield);
   }

   /* We now have our complete statement; Lets connect to the server and execute it. */
   if (pgsql_exec(database, table, ast_str_buffer(sql), &result) != 0) {
      ast_mutex_unlock(&pgsql_lock);
      ast_config_destroy(cfg);
      return NULL;
   } else {
      ExecStatusType result_status = PQresultStatus(result);
      if (result_status != PGRES_COMMAND_OK
         && result_status != PGRES_TUPLES_OK
         && result_status != PGRES_NONFATAL_ERROR) {
         ast_log(LOG_WARNING,
               "PostgreSQL RealTime: Failed to query %s@%s. Check debug for more info.\n", table, database);
         ast_debug(1, "PostgreSQL RealTime: Query: %s\n", ast_str_buffer(sql));
         ast_debug(1, "PostgreSQL RealTime: Query Failed because: %s (%s)\n",
                  PQresultErrorMessage(result), PQresStatus(result_status));
         ast_mutex_unlock(&pgsql_lock);
         ast_config_destroy(cfg);
         return NULL;
      }
   }

   ast_debug(1, "PostgreSQL RealTime: Result=%p Query: %s\n", result, ast_str_buffer(sql));

   if ((num_rows = PQntuples(result)) > 0) {
      int numFields = PQnfields(result);
      int i = 0;
      int rowIndex = 0;
      char **fieldnames = NULL;

      ast_debug(1, "PostgreSQL RealTime: Found %d rows.\n", num_rows);

      if (!(fieldnames = ast_calloc(1, numFields * sizeof(char *)))) {
         ast_mutex_unlock(&pgsql_lock);
         ast_config_destroy(cfg);
         return NULL;
      }
      for (i = 0; i < numFields; i++)
         fieldnames[i] = PQfname(result, i);

      for (rowIndex = 0; rowIndex < num_rows; rowIndex++) {
         var = NULL;
         cat = ast_category_new_anonymous();
         if (!cat) {
            continue;
         }
         for (i = 0; i < numFields; i++) {
            stringp = PQgetvalue(result, rowIndex, i);
            while (stringp) {
               chunk = strsep(&stringp, ";");
               if (chunk && !ast_strlen_zero(ast_realtime_decode_chunk(ast_strip(chunk)))) {
                  if (initfield && !strcmp(initfield, fieldnames[i])) {
                     ast_category_rename(cat, chunk);
                  }
                  var = ast_variable_new(fieldnames[i], chunk, "");
                  ast_variable_append(cat, var);
               }
            }
         }
         ast_category_append(cfg, cat);
      }
      ast_free(fieldnames);
   } else {
      ast_debug(1, "PostgreSQL RealTime: Could not find any rows in table %s.\n", table);
   }

   ast_mutex_unlock(&pgsql_lock);

   return cfg;
}

static int update_pgsql(const char *database, const char *tablename, const char *keyfield,
                  const char *lookup, const struct ast_variable *fields)
{
   RAII_VAR(PGresult *, result, NULL, PQclear);
   int numrows = 0, pgresult;
   const struct ast_variable *field = fields;
   struct ast_str *sql = ast_str_thread_get(&sql_buf, 100);
   struct ast_str *escapebuf = ast_str_thread_get(&escapebuf_buf, 100);
   struct tables *table;
   struct columns *column = NULL;

   /*
    * Ignore database from the extconfig.conf since it was
    * configured by res_pgsql.conf.
    */
   database = dbname;

   if (!tablename) {
      ast_log(LOG_WARNING, "PostgreSQL RealTime: No table specified.\n");
      return -1;
   }

   if (!(table = find_table(database, tablename))) {
      ast_log(LOG_ERROR, "Table '%s' does not exist!!\n", tablename);
      return -1;
   }

   /*
    * Must connect to the server before anything else as ESCAPE_STRING()
    * uses pgsqlConn
    */
   ast_mutex_lock(&pgsql_lock);
   if (!pgsql_reconnect(database)) {
      ast_mutex_unlock(&pgsql_lock);
      release_table(table);
      return -1;
   }

   /* Get the first parameter and first value in our list of passed paramater/value pairs */
   if (!field) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: Realtime retrieval requires at least 1 parameter and 1 value to search on.\n");
      if (pgsqlConn) {
         PQfinish(pgsqlConn);
         pgsqlConn = NULL;
      }
      ast_mutex_unlock(&pgsql_lock);
      release_table(table);
      return -1;
   }

   /* Check that the column exists in the table */
   AST_LIST_TRAVERSE(&table->columns, column, list) {
      if (strcmp(column->name, field->name) == 0) {
         break;
      }
   }

   if (!column) {
      ast_log(LOG_ERROR, "PostgreSQL RealTime: Updating on column '%s', but that column does not exist within the table '%s'!\n", field->name, tablename);
      ast_mutex_unlock(&pgsql_lock);
      release_table(table);
      return -1;
   }

   /* Create the first part of the query using the first parameter/value pairs we just extracted
      If there is only 1 set, then we have our query. Otherwise, loop thru the list and concat */

   ESCAPE_STRING(escapebuf, field->value);
   if (pgresult) {
      ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", field->value);
      ast_mutex_unlock(&pgsql_lock);
      release_table(table);
      return -1;
   }
   ast_str_set(&sql, 0, "UPDATE %s SET %s = '%s'", tablename, field->name, ast_str_buffer(escapebuf));

   while ((field = field->next)) {
      if (!find_column(table, field->name)) {
         ast_log(LOG_NOTICE, "Attempted to update column '%s' in table '%s', but column does not exist!\n", field->name, tablename);
         continue;
      }

      ESCAPE_STRING(escapebuf, field->value);
      if (pgresult) {
         ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", field->value);
         ast_mutex_unlock(&pgsql_lock);
         release_table(table);
         return -1;
      }

      ast_str_append(&sql, 0, ", %s = '%s'", field->name, ast_str_buffer(escapebuf));
   }
   release_table(table);

   ESCAPE_STRING(escapebuf, lookup);
   if (pgresult) {
      ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", lookup);
      ast_mutex_unlock(&pgsql_lock);
      return -1;
   }

   ast_str_append(&sql, 0, " WHERE %s = '%s'", keyfield, ast_str_buffer(escapebuf));

   ast_debug(1, "PostgreSQL RealTime: Update SQL: %s\n", ast_str_buffer(sql));

   /* We now have our complete statement; Lets connect to the server and execute it. */
   if (pgsql_exec(database, tablename, ast_str_buffer(sql), &result) != 0) {
      ast_mutex_unlock(&pgsql_lock);
      return -1;
   } else {
      ExecStatusType result_status = PQresultStatus(result);
      if (result_status != PGRES_COMMAND_OK
         && result_status != PGRES_TUPLES_OK
         && result_status != PGRES_NONFATAL_ERROR) {
         ast_log(LOG_WARNING,
               "PostgreSQL RealTime: Failed to query database. Check debug for more info.\n");
         ast_debug(1, "PostgreSQL RealTime: Query: %s\n", ast_str_buffer(sql));
         ast_debug(1, "PostgreSQL RealTime: Query Failed because: %s (%s)\n",
                  PQresultErrorMessage(result), PQresStatus(result_status));
         ast_mutex_unlock(&pgsql_lock);
         return -1;
      }
   }

   numrows = atoi(PQcmdTuples(result));
   ast_mutex_unlock(&pgsql_lock);

   ast_debug(1, "PostgreSQL RealTime: Updated %d rows on table: %s\n", numrows, tablename);

   /* From http://dev.pgsql.com/doc/pgsql/en/pgsql-affected-rows.html
    * An integer greater than zero indicates the number of rows affected
    * Zero indicates that no records were updated
    * -1 indicates that the query returned an error (although, if the query failed, it should have been caught above.)
    */

   if (numrows >= 0)
      return (int) numrows;

   return -1;
}

static int update2_pgsql(const char *database, const char *tablename, const struct ast_variable *lookup_fields, const struct ast_variable *update_fields)
{
   RAII_VAR(PGresult *, result, NULL, PQclear);
   int numrows = 0, pgresult, first = 1;
   struct ast_str *escapebuf = ast_str_thread_get(&escapebuf_buf, 16);
   const struct ast_variable *field;
   struct ast_str *sql = ast_str_thread_get(&sql_buf, 100);
   struct ast_str *where = ast_str_thread_get(&where_buf, 100);
   struct tables *table;

   /*
    * Ignore database from the extconfig.conf since it was
    * configured by res_pgsql.conf.
    */
   database = dbname;

   if (!tablename) {
      ast_log(LOG_WARNING, "PostgreSQL RealTime: No table specified.\n");
      return -1;
   }

   if (!escapebuf || !sql || !where) {
      /* Memory error, already handled */
      return -1;
   }

   if (!(table = find_table(database, tablename))) {
      ast_log(LOG_ERROR, "Table '%s' does not exist!!\n", tablename);
      return -1;
   }

   /*
    * Must connect to the server before anything else as ESCAPE_STRING()
    * uses pgsqlConn
    */
   ast_mutex_lock(&pgsql_lock);
   if (!pgsql_reconnect(database)) {
      ast_mutex_unlock(&pgsql_lock);
      release_table(table);
      return -1;
   }

   ast_str_set(&sql, 0, "UPDATE %s SET", tablename);
   ast_str_set(&where, 0, " WHERE");

   for (field = lookup_fields; field; field = field->next) {
      if (!find_column(table, field->name)) {
         ast_log(LOG_ERROR, "Attempted to update based on criteria column '%s' (%s@%s), but that column does not exist!\n", field->name, tablename, database);
         ast_mutex_unlock(&pgsql_lock);
         release_table(table);
         return -1;
      }

      ESCAPE_STRING(escapebuf, field->value);
      if (pgresult) {
         ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", field->value);
         ast_mutex_unlock(&pgsql_lock);
         release_table(table);
         return -1;
      }
      ast_str_append(&where, 0, "%s %s='%s'", first ? "" : " AND", field->name, ast_str_buffer(escapebuf));
      first = 0;
   }

   if (first) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: Realtime update requires at least 1 parameter and 1 value to search on.\n");
      if (pgsqlConn) {
         PQfinish(pgsqlConn);
         pgsqlConn = NULL;
      }
      ast_mutex_unlock(&pgsql_lock);
      release_table(table);
      return -1;
   }

   /* Now retrieve the columns to update */
   first = 1;
   for (field = update_fields; field; field = field->next) {
      /* If the column is not within the table, then skip it */
      if (!find_column(table, field->name)) {
         ast_log(LOG_NOTICE, "Attempted to update column '%s' in table '%s@%s', but column does not exist!\n", field->name, tablename, database);
         continue;
      }

      ESCAPE_STRING(escapebuf, field->value);
      if (pgresult) {
         ast_log(LOG_ERROR, "PostgreSQL RealTime: detected invalid input: '%s'\n", field->value);
         ast_mutex_unlock(&pgsql_lock);
         release_table(table);
         return -1;
      }

      ast_str_append(&sql, 0, "%s %s='%s'", first ? "" : ",", field->name, ast_str_buffer(escapebuf));
      first = 0;
   }
   release_table(table);

   ast_str_append(&sql, 0, "%s", ast_str_buffer(where));

   ast_debug(1, "PostgreSQL RealTime: Update SQL: %s\n", ast_str_buffer(sql));

   /* We now have our complete statement; Lets connect to the server and execute it. */
        if (pgsql_exec(database, tablename, ast_str_buffer(sql), &result) != 0) {
      ast_mutex_unlock(&pgsql_lock);
           return -1;
        }

   numrows = atoi(PQcmdTuples(result));
   ast_mutex_unlock(&pgsql_lock);

   ast_debug(1, "PostgreSQL RealTime: Updated %d rows on table: %s\n", numrows, tablename);

   /* From http://dev.pgsql.com/doc/pgsql/en/pgsql-affected-rows.html
    * An integer greater than zero indicates the number of rows affected
    * Zero indicates that no records were updated
    * -1 indicates that the query returned an error (although, if the query failed, it should have been caught above.)
    */

   if (numrows >= 0) {
      return (int) numrows;
   }

   return -1;
}

static int store_pgsql(const char *database, const char *table, const struct ast_variable *fields)
{
   RAII_VAR(PGresult *, result, NULL, PQclear);
   int numrows;
   struct ast_str *buf = ast_str_thread_get(&escapebuf_buf, 256);
   struct ast_str *sql1 = ast_str_thread_get(&sql_buf, 256);
   struct ast_str *sql2 = ast_str_thread_get(&where_buf, 256);
   int pgresult;
   const struct ast_variable *field = fields;

   /*
    * Ignore database from the extconfig.conf since it was
    * configured by res_pgsql.conf.
    */
   database = dbname;

   if (!table) {
      ast_log(LOG_WARNING, "PostgreSQL RealTime: No table specified.\n");
      return -1;
   }

   /*
    * Must connect to the server before anything else as ESCAPE_STRING()
    * uses pgsqlConn
    */
   ast_mutex_lock(&pgsql_lock);
   if (!pgsql_reconnect(database)) {
      ast_mutex_unlock(&pgsql_lock);
      return -1;
   }

   /* Get the first parameter and first value in our list of passed paramater/value pairs */
   if (!field) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: Realtime storage requires at least 1 parameter and 1 value to store.\n");
      if (pgsqlConn) {
         PQfinish(pgsqlConn);
         pgsqlConn = NULL;
      }
      ast_mutex_unlock(&pgsql_lock);
      return -1;
   }

   /* Create the first part of the query using the first parameter/value pairs we just extracted
      If there is only 1 set, then we have our query. Otherwise, loop thru the list and concat */
   ESCAPE_STRING(buf, field->name);
   ast_str_set(&sql1, 0, "INSERT INTO %s (%s", table, ast_str_buffer(buf));
   ESCAPE_STRING(buf, field->value);
   ast_str_set(&sql2, 0, ") VALUES ('%s'", ast_str_buffer(buf));
   while ((field = field->next)) {
      ESCAPE_STRING(buf, field->name);
      ast_str_append(&sql1, 0, ", %s", ast_str_buffer(buf));
      ESCAPE_STRING(buf, field->value);
      ast_str_append(&sql2, 0, ", '%s'", ast_str_buffer(buf));
   }
   ast_str_append(&sql1, 0, "%s)", ast_str_buffer(sql2));

   ast_debug(1, "PostgreSQL RealTime: Insert SQL: %s\n", ast_str_buffer(sql1));

   /* We now have our complete statement; Lets connect to the server and execute it. */
        if (pgsql_exec(database, table, ast_str_buffer(sql1), &result) != 0) {
      ast_mutex_unlock(&pgsql_lock);
           return -1;
        }

   numrows = atoi(PQcmdTuples(result));
   ast_mutex_unlock(&pgsql_lock);

   ast_debug(1, "PostgreSQL RealTime: row inserted on table: %s.\n", table);

   /* From http://dev.pgsql.com/doc/pgsql/en/pgsql-affected-rows.html
    * An integer greater than zero indicates the number of rows affected
    * Zero indicates that no records were updated
    * -1 indicates that the query returned an error (although, if the query failed, it should have been caught above.)
    */

   if (numrows >= 0) {
      return numrows;
   }

   return -1;
}

static int destroy_pgsql(const char *database, const char *table, const char *keyfield, const char *lookup, const struct ast_variable *fields)
{
   RAII_VAR(PGresult *, result, NULL, PQclear);
   int numrows = 0;
   int pgresult;
   struct ast_str *sql = ast_str_thread_get(&sql_buf, 256);
   struct ast_str *buf1 = ast_str_thread_get(&where_buf, 60), *buf2 = ast_str_thread_get(&escapebuf_buf, 60);
   const struct ast_variable *field;

   /*
    * Ignore database from the extconfig.conf since it was
    * configured by res_pgsql.conf.
    */
   database = dbname;

   if (!table) {
      ast_log(LOG_WARNING, "PostgreSQL RealTime: No table specified.\n");
      return -1;
   }

   /*
    * Must connect to the server before anything else as ESCAPE_STRING()
    * uses pgsqlConn
    */
   ast_mutex_lock(&pgsql_lock);
   if (!pgsql_reconnect(database)) {
      ast_mutex_unlock(&pgsql_lock);
      return -1;
   }

   /* Get the first parameter and first value in our list of passed paramater/value pairs */
   if (ast_strlen_zero(keyfield) || ast_strlen_zero(lookup))  {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: Realtime destroy requires at least 1 parameter and 1 value to search on.\n");
      if (pgsqlConn) {
         PQfinish(pgsqlConn);
         pgsqlConn = NULL;
      }
      ast_mutex_unlock(&pgsql_lock);
      return -1;
   }

   /* Create the first part of the query using the first parameter/value pairs we just extracted
      If there is only 1 set, then we have our query. Otherwise, loop thru the list and concat */

   ESCAPE_STRING(buf1, keyfield);
   ESCAPE_STRING(buf2, lookup);
   ast_str_set(&sql, 0, "DELETE FROM %s WHERE %s = '%s'", table, ast_str_buffer(buf1), ast_str_buffer(buf2));
   for (field = fields; field; field = field->next) {
      ESCAPE_STRING(buf1, field->name);
      ESCAPE_STRING(buf2, field->value);
      ast_str_append(&sql, 0, " AND %s = '%s'", ast_str_buffer(buf1), ast_str_buffer(buf2));
   }

   ast_debug(1, "PostgreSQL RealTime: Delete SQL: %s\n", ast_str_buffer(sql));

   /* We now have our complete statement; Lets connect to the server and execute it. */
   if (pgsql_exec(database, table, ast_str_buffer(sql), &result) != 0) {
      ast_mutex_unlock(&pgsql_lock);
      return -1;
   }

   numrows = atoi(PQcmdTuples(result));
   ast_mutex_unlock(&pgsql_lock);

   ast_debug(1, "PostgreSQL RealTime: Deleted %d rows on table: %s\n", numrows, table);

   /* From http://dev.pgsql.com/doc/pgsql/en/pgsql-affected-rows.html
    * An integer greater than zero indicates the number of rows affected
    * Zero indicates that no records were updated
    * -1 indicates that the query returned an error (although, if the query failed, it should have been caught above.)
    */

   if (numrows >= 0)
      return (int) numrows;

   return -1;
}


static struct ast_config *config_pgsql(const char *database, const char *table,
                              const char *file, struct ast_config *cfg,
                              struct ast_flags flags, const char *suggested_incl, const char *who_asked)
{
   RAII_VAR(PGresult *, result, NULL, PQclear);
   long num_rows;
   struct ast_variable *new_v;
   struct ast_category *cur_cat = NULL;
   struct ast_str *sql = ast_str_thread_get(&sql_buf, 100);
   char last[80];
   int last_cat_metric = 0;

   last[0] = '\0';

   /*
    * Ignore database from the extconfig.conf since it is
    * configured by res_pgsql.conf.
    */
   database = dbname;

   if (!file || !strcmp(file, RES_CONFIG_PGSQL_CONF)) {
      ast_log(LOG_WARNING, "PostgreSQL RealTime: Cannot configure myself.\n");
      return NULL;
   }

   ast_str_set(&sql, 0, "SELECT category, var_name, var_val, cat_metric FROM %s "
         "WHERE filename='%s' and commented=0 "
         "ORDER BY cat_metric DESC, var_metric ASC, category, var_name ", table, file);

   ast_debug(1, "PostgreSQL RealTime: Static SQL: %s\n", ast_str_buffer(sql));

   ast_mutex_lock(&pgsql_lock);

   /* We now have our complete statement; Lets connect to the server and execute it. */
        if (pgsql_exec(database, table, ast_str_buffer(sql), &result) != 0) {
      ast_mutex_unlock(&pgsql_lock);
           return NULL;
        }

   if ((num_rows = PQntuples(result)) > 0) {
      int rowIndex = 0;

      ast_debug(1, "PostgreSQL RealTime: Found %ld rows.\n", num_rows);

      for (rowIndex = 0; rowIndex < num_rows; rowIndex++) {
         char *field_category = PQgetvalue(result, rowIndex, 0);
         char *field_var_name = PQgetvalue(result, rowIndex, 1);
         char *field_var_val = PQgetvalue(result, rowIndex, 2);
         char *field_cat_metric = PQgetvalue(result, rowIndex, 3);
         if (!strcmp(field_var_name, "#include")) {
            if (!ast_config_internal_load(field_var_val, cfg, flags, "", who_asked)) {
               ast_mutex_unlock(&pgsql_lock);
               return NULL;
            }
            continue;
         }

         if (strcmp(last, field_category) || last_cat_metric != atoi(field_cat_metric)) {
            cur_cat = ast_category_new_dynamic(field_category);
            if (!cur_cat) {
               break;
            }
            ast_copy_string(last, field_category, sizeof(last));
            last_cat_metric = atoi(field_cat_metric);
            ast_category_append(cfg, cur_cat);
         }
         new_v = ast_variable_new(field_var_name, field_var_val, "");
         ast_variable_append(cur_cat, new_v);
      }
   } else {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: Could not find config '%s' in database.\n", file);
   }

   ast_mutex_unlock(&pgsql_lock);

   return cfg;
}

static int require_pgsql(const char *database, const char *tablename, va_list ap)
{
   struct columns *column;
   struct tables *table;
   char *elm;
   int type, res = 0;
   unsigned int size;

   /*
    * Ignore database from the extconfig.conf since it was
    * configured by res_pgsql.conf.
    */
   database = dbname;

   table = find_table(database, tablename);
   if (!table) {
      ast_log(LOG_WARNING, "Table %s not found in database.  This table should exist if you're using realtime.\n", tablename);
      return -1;
   }

   while ((elm = va_arg(ap, char *))) {
      type = va_arg(ap, require_type);
      size = va_arg(ap, unsigned int);
      AST_LIST_TRAVERSE(&table->columns, column, list) {
         if (strcmp(column->name, elm) == 0) {
            /* Char can hold anything, as long as it is large enough */
            if ((strncmp(column->type, "char", 4) == 0 || strncmp(column->type, "varchar", 7) == 0 || strcmp(column->type, "bpchar") == 0)) {
               if ((size > column->len) && column->len != -1) {
                  ast_log(LOG_WARNING, "Column '%s' should be at least %d long, but is only %d long.\n", column->name, size, column->len);
                  res = -1;
               }
            } else if (strncmp(column->type, "int", 3) == 0) {
               int typesize = atoi(column->type + 3);
               /* Integers can hold only other integers */
               if ((type == RQ_INTEGER8 || type == RQ_UINTEGER8 ||
                  type == RQ_INTEGER4 || type == RQ_UINTEGER4 ||
                  type == RQ_INTEGER3 || type == RQ_UINTEGER3 ||
                  type == RQ_UINTEGER2) && typesize == 2) {
                  ast_log(LOG_WARNING, "Column '%s' may not be large enough for the required data length: %d\n", column->name, size);
                  res = -1;
               } else if ((type == RQ_INTEGER8 || type == RQ_UINTEGER8 ||
                  type == RQ_UINTEGER4) && typesize == 4) {
                  ast_log(LOG_WARNING, "Column '%s' may not be large enough for the required data length: %d\n", column->name, size);
                  res = -1;
               } else if (type == RQ_CHAR || type == RQ_DATETIME || type == RQ_FLOAT || type == RQ_DATE) {
                  ast_log(LOG_WARNING, "Column '%s' is of the incorrect type: (need %s(%d) but saw %s)\n",
                     column->name,
                        type == RQ_CHAR ? "char" :
                        type == RQ_DATETIME ? "datetime" :
                        type == RQ_DATE ? "date" :
                        type == RQ_FLOAT ? "float" :
                        "a rather stiff drink ",
                     size, column->type);
                  res = -1;
               }
            } else if (strncmp(column->type, "float", 5) == 0) {
               if (!ast_rq_is_int(type) && type != RQ_FLOAT) {
                  ast_log(LOG_WARNING, "Column %s cannot be a %s\n", column->name, column->type);
                  res = -1;
               }
            } else if (strncmp(column->type, "timestamp", 9) == 0) {
               if (type != RQ_DATETIME && type != RQ_DATE) {
                  ast_log(LOG_WARNING, "Column %s cannot be a %s\n", column->name, column->type);
                  res = -1;
               }
            } else { /* There are other types that no module implements yet */
               ast_log(LOG_WARNING, "Possibly unsupported column type '%s' on column '%s'\n", column->type, column->name);
               res = -1;
            }
            break;
         }
      }

      if (!column) {
         if (requirements == RQ_WARN) {
            ast_log(LOG_WARNING, "Table %s requires a column '%s' of size '%d', but no such column exists.\n", tablename, elm, size);
            res = -1;
         } else {
            struct ast_str *sql = ast_str_create(100);
            char fieldtype[10];
            PGresult *result;

            if (requirements == RQ_CREATECHAR || type == RQ_CHAR) {
               /* Size is minimum length; make it at least 50% greater,
                * just to be sure, because PostgreSQL doesn't support
                * resizing columns. */
               snprintf(fieldtype, sizeof(fieldtype), "CHAR(%u)",
                  size < 15 ? size * 2 :
                  (size * 3 / 2 > 255) ? 255 : size * 3 / 2);
            } else if (type == RQ_INTEGER1 || type == RQ_UINTEGER1 || type == RQ_INTEGER2) {
               snprintf(fieldtype, sizeof(fieldtype), "INT2");
            } else if (type == RQ_UINTEGER2 || type == RQ_INTEGER3 || type == RQ_UINTEGER3 || type == RQ_INTEGER4) {
               snprintf(fieldtype, sizeof(fieldtype), "INT4");
            } else if (type == RQ_UINTEGER4 || type == RQ_INTEGER8) {
               snprintf(fieldtype, sizeof(fieldtype), "INT8");
            } else if (type == RQ_UINTEGER8) {
               /* No such type on PostgreSQL */
               snprintf(fieldtype, sizeof(fieldtype), "CHAR(20)");
            } else if (type == RQ_FLOAT) {
               snprintf(fieldtype, sizeof(fieldtype), "FLOAT8");
            } else if (type == RQ_DATE) {
               snprintf(fieldtype, sizeof(fieldtype), "DATE");
            } else if (type == RQ_DATETIME) {
               snprintf(fieldtype, sizeof(fieldtype), "TIMESTAMP");
            } else {
               ast_log(LOG_ERROR, "Unrecognized request type %d\n", type);
               ast_free(sql);
               continue;
            }
            ast_str_set(&sql, 0, "ALTER TABLE %s ADD COLUMN %s %s", tablename, elm, fieldtype);
            ast_debug(1, "About to lock pgsql_lock (running alter on table '%s' to add column '%s')\n", tablename, elm);

            ast_mutex_lock(&pgsql_lock);
            ast_debug(1, "About to run ALTER query on table '%s' to add column '%s'\n", tablename, elm);

                 if (pgsql_exec(database, tablename, ast_str_buffer(sql), &result) != 0) {
               ast_mutex_unlock(&pgsql_lock);
               release_table(table);
                    return -1;
                 }

            ast_debug(1, "Finished running ALTER query on table '%s'\n", tablename);
            if (PQresultStatus(result) != PGRES_COMMAND_OK) {
               ast_log(LOG_ERROR, "Unable to add column: %s\n", ast_str_buffer(sql));
            }
            PQclear(result);
            ast_mutex_unlock(&pgsql_lock);

            ast_free(sql);
         }
      }
   }
   release_table(table);
   return res;
}

static int unload_pgsql(const char *database, const char *tablename)
{
   struct tables *cur;

   /*
    * Ignore database from the extconfig.conf since it was
    * configured by res_pgsql.conf.
    */
   database = dbname;

   ast_debug(2, "About to lock table cache list\n");
   AST_LIST_LOCK(&psql_tables);
   ast_debug(2, "About to traverse table cache list\n");
   AST_LIST_TRAVERSE_SAFE_BEGIN(&psql_tables, cur, list) {
      if (strcmp(cur->name, tablename) == 0) {
         ast_debug(2, "About to remove matching cache entry\n");
         AST_LIST_REMOVE_CURRENT(list);
         ast_debug(2, "About to destroy matching cache entry\n");
         destroy_table(cur);
         ast_debug(1, "Cache entry '%s@%s' destroyed\n", tablename, database);
         break;
      }
   }
   AST_LIST_TRAVERSE_SAFE_END
   AST_LIST_UNLOCK(&psql_tables);
   ast_debug(2, "About to return\n");
   return cur ? 0 : -1;
}

static struct ast_config_engine pgsql_engine = {
   .name = "pgsql",
   .load_func = config_pgsql,
   .realtime_func = realtime_pgsql,
   .realtime_multi_func = realtime_multi_pgsql,
   .store_func = store_pgsql,
   .destroy_func = destroy_pgsql,
   .update_func = update_pgsql,
   .update2_func = update2_pgsql,
   .require_func = require_pgsql,
   .unload_func = unload_pgsql,
};

static int load_module(void)
{
   if(!parse_config(0))
      return AST_MODULE_LOAD_DECLINE;

   ast_config_engine_register(&pgsql_engine);

   ast_cli_register_multiple(cli_realtime, ARRAY_LEN(cli_realtime));

   return 0;
}

static int unload_module(void)
{
   struct tables *table;
   /* Acquire control before doing anything to the module itself. */
   ast_mutex_lock(&pgsql_lock);

   if (pgsqlConn) {
      PQfinish(pgsqlConn);
      pgsqlConn = NULL;
   }
   ast_cli_unregister_multiple(cli_realtime, ARRAY_LEN(cli_realtime));
   ast_config_engine_deregister(&pgsql_engine);

   /* Unlock so something else can destroy the lock. */
   ast_mutex_unlock(&pgsql_lock);

   /* Destroy cached table info */
   AST_LIST_LOCK(&psql_tables);
   while ((table = AST_LIST_REMOVE_HEAD(&psql_tables, list))) {
      destroy_table(table);
   }
   AST_LIST_UNLOCK(&psql_tables);

   return 0;
}

static int reload(void)
{
   parse_config(1);

   return 0;
}

static int parse_config(int is_reload)
{
   struct ast_config *config;
   const char *s;
   struct ast_flags config_flags = { is_reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };

   config = ast_config_load(RES_CONFIG_PGSQL_CONF, config_flags);
   if (config == CONFIG_STATUS_FILEUNCHANGED) {
      if (is_reload && pgsqlConn && PQstatus(pgsqlConn) != CONNECTION_OK) {
         ast_log(LOG_WARNING,  "PostgreSQL RealTime: Not connected\n");
      }
      return 0;
   }

   if (config == CONFIG_STATUS_FILEMISSING || config == CONFIG_STATUS_FILEINVALID) {
      ast_log(LOG_WARNING, "Unable to load config %s\n", RES_CONFIG_PGSQL_CONF);
      return 0;
   }

   ast_mutex_lock(&pgsql_lock);

   /* XXX: Why would we do this before we're ready to establish a new connection? */
   if (pgsqlConn) {
      PQfinish(pgsqlConn);
      pgsqlConn = NULL;
   }

   if (!(s = ast_variable_retrieve(config, "general", "dbuser"))) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: No database user found, using 'asterisk' as default.\n");
      strcpy(dbuser, "asterisk");
   } else {
      ast_copy_string(dbuser, s, sizeof(dbuser));
   }

   if (!(s = ast_variable_retrieve(config, "general", "dbpass"))) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: No database password found, using 'asterisk' as default.\n");
      strcpy(dbpass, "asterisk");
   } else {
      ast_copy_string(dbpass, s, sizeof(dbpass));
   }

   if (!(s = ast_variable_retrieve(config, "general", "dbhost"))) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: No database host found, using localhost via socket.\n");
      dbhost[0] = '\0';
   } else {
      ast_copy_string(dbhost, s, sizeof(dbhost));
   }

   if (!(s = ast_variable_retrieve(config, "general", "dbname"))) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: No database name found, using 'asterisk' as default.\n");
      strcpy(dbname, "asterisk");
   } else {
      ast_copy_string(dbname, s, sizeof(dbname));
   }

   if (!(s = ast_variable_retrieve(config, "general", "dbport"))) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: No database port found, using 5432 as default.\n");
      dbport = 5432;
   } else {
      dbport = atoi(s);
   }

   if (!(s = ast_variable_retrieve(config, "general", "dbappname"))) {
      dbappname[0] = '\0';
   } else {
      ast_copy_string(dbappname, s, sizeof(dbappname));
   }

   if (!ast_strlen_zero(dbhost)) {
      /* No socket needed */
   } else if (!(s = ast_variable_retrieve(config, "general", "dbsock"))) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: No database socket found, using '/tmp/.s.PGSQL.%d' as default.\n", dbport);
      strcpy(dbsock, "/tmp");
   } else {
      ast_copy_string(dbsock, s, sizeof(dbsock));
   }

   if (!(s = ast_variable_retrieve(config, "general", "requirements"))) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: no requirements setting found, using 'warn' as default.\n");
      requirements = RQ_WARN;
   } else if (!strcasecmp(s, "createclose")) {
      requirements = RQ_CREATECLOSE;
   } else if (!strcasecmp(s, "createchar")) {
      requirements = RQ_CREATECHAR;
   }

   ast_config_destroy(config);

   if (DEBUG_ATLEAST(1)) {
      if (!ast_strlen_zero(dbhost)) {
         ast_log(LOG_DEBUG, "PostgreSQL RealTime Host: %s\n", dbhost);
         ast_log(LOG_DEBUG, "PostgreSQL RealTime Port: %i\n", dbport);
      } else {
         ast_log(LOG_DEBUG, "PostgreSQL RealTime Socket: %s\n", dbsock);
      }
      ast_log(LOG_DEBUG, "PostgreSQL RealTime User: %s\n", dbuser);
      ast_log(LOG_DEBUG, "PostgreSQL RealTime Password: %s\n", dbpass);
      ast_log(LOG_DEBUG, "PostgreSQL RealTime DBName: %s\n", dbname);
   }

   if (!pgsql_reconnect(NULL)) {
      ast_log(LOG_WARNING,
            "PostgreSQL RealTime: Couldn't establish connection. Check debug.\n");
      ast_debug(1, "PostgreSQL RealTime: Cannot Connect: %s\n", PQerrorMessage(pgsqlConn));
   }

   ast_verb(2, "PostgreSQL RealTime reloaded.\n");

   /* Done reloading. Release lock so others can now use driver. */
   ast_mutex_unlock(&pgsql_lock);

   return 1;
}

static int pgsql_reconnect(const char *database)
{
   char my_database[50];

   ast_copy_string(my_database, S_OR(database, dbname), sizeof(my_database));

   /* mutex lock should have been locked before calling this function. */

   if (pgsqlConn) {
      if (PQstatus(pgsqlConn) == CONNECTION_OK) {
         /* We're good? */
         return 1;
      }

      PQfinish(pgsqlConn);
      pgsqlConn = NULL;
   }

   /* DB password can legitimately be 0-length */
   if ((!ast_strlen_zero(dbhost) || !ast_strlen_zero(dbsock)) && !ast_strlen_zero(dbuser) && !ast_strlen_zero(my_database)) {
      struct ast_str *conn_info = ast_str_create(128);

      if (!conn_info) {
         ast_log(LOG_ERROR, "PostgreSQL RealTime: Failed to allocate memory for connection string.\n");
         return 0;
      }

      ast_str_set(&conn_info, 0, "host=%s port=%d dbname=%s user=%s",
         S_OR(dbhost, dbsock), dbport, my_database, dbuser);

      if (!ast_strlen_zero(dbappname)) {
         ast_str_append(&conn_info, 0, " application_name=%s", dbappname);
      }

      if (!ast_strlen_zero(dbpass)) {
         ast_str_append(&conn_info, 0, " password=%s", dbpass);
      }

      pgsqlConn = PQconnectdb(ast_str_buffer(conn_info));
      ast_free(conn_info);
      conn_info = NULL;

      ast_debug(1, "pgsqlConn=%p\n", pgsqlConn);
      if (pgsqlConn && PQstatus(pgsqlConn) == CONNECTION_OK) {
         ast_debug(1, "PostgreSQL RealTime: Successfully connected to database.\n");
         connect_time = time(NULL);
         version = PQserverVersion(pgsqlConn);
         return 1;
      } else {
         ast_log(LOG_ERROR,
               "PostgreSQL RealTime: Failed to connect database %s on %s: %s\n",
               my_database, dbhost, PQresultErrorMessage(NULL));
         return 0;
      }
   } else {
      ast_debug(1, "PostgreSQL RealTime: One or more of the parameters in the config does not pass our validity checks.\n");
      return 1;
   }
}

static char *handle_cli_realtime_pgsql_cache(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   struct tables *cur;
   int l, which;
   char *ret = NULL;

   switch (cmd) {
   case CLI_INIT:
      e->command = "realtime show pgsql cache";
      e->usage =
         "Usage: realtime show pgsql cache [<table>]\n"
         "       Shows table cache for the PostgreSQL RealTime driver\n";
      return NULL;
   case CLI_GENERATE:
      if (a->argc != 4) {
         return NULL;
      }
      l = strlen(a->word);
      which = 0;
      AST_LIST_LOCK(&psql_tables);
      AST_LIST_TRAVERSE(&psql_tables, cur, list) {
         if (!strncasecmp(a->word, cur->name, l) && ++which > a->n) {
            ret = ast_strdup(cur->name);
            break;
         }
      }
      AST_LIST_UNLOCK(&psql_tables);
      return ret;
   }

   if (a->argc == 4) {
      /* List of tables */
      AST_LIST_LOCK(&psql_tables);
      AST_LIST_TRAVERSE(&psql_tables, cur, list) {
         ast_cli(a->fd, "%s\n", cur->name);
      }
      AST_LIST_UNLOCK(&psql_tables);
   } else if (a->argc == 5) {
      /* List of columns */
      if ((cur = find_table(NULL, a->argv[4]))) {
         struct columns *col;
         ast_cli(a->fd, "Columns for Table Cache '%s':\n", a->argv[4]);
         ast_cli(a->fd, "%-20.20s %-20.20s %-3.3s %-8.8s\n", "Name", "Type", "Len", "Nullable");
         AST_LIST_TRAVERSE(&cur->columns, col, list) {
            ast_cli(a->fd, "%-20.20s %-20.20s %3d %-8.8s\n", col->name, col->type, col->len, col->notnull ? "NOT NULL" : "");
         }
         release_table(cur);
      } else {
         ast_cli(a->fd, "No such table '%s'\n", a->argv[4]);
      }
   }
   return 0;
}

static char *handle_cli_realtime_pgsql_status(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
{
   char connection_info[256];
   char credentials[100] = "";
   char buf[376]; /* 256+100+"Connected to "+" for "+NULL */
   int is_connected = 0, ctimesec = time(NULL) - connect_time;

   switch (cmd) {
   case CLI_INIT:
      e->command = "realtime show pgsql status";
      e->usage =
         "Usage: realtime show pgsql status\n"
         "       Shows connection information for the PostgreSQL RealTime driver\n";
      return NULL;
   case CLI_GENERATE:
      return NULL;
   }

   if (a->argc != 4)
      return CLI_SHOWUSAGE;

   if (!ast_strlen_zero(dbhost))
      snprintf(connection_info, sizeof(connection_info), "%s@%s, port %d", dbname, dbhost, dbport);
   else if (!ast_strlen_zero(dbsock))
      snprintf(connection_info, sizeof(connection_info), "%s on socket file %s", dbname, dbsock);
   else
      snprintf(connection_info, sizeof(connection_info), "%s@%s", dbname, dbhost);

   if (!ast_strlen_zero(dbuser))
      snprintf(credentials, sizeof(credentials), " with username %s", dbuser);

   ast_mutex_lock(&pgsql_lock);
   is_connected = (pgsqlConn && PQstatus(pgsqlConn) == CONNECTION_OK);
   ast_mutex_unlock(&pgsql_lock);

   if (is_connected) {
      snprintf(buf, sizeof(buf), "Connected to %s%s for ", connection_info, credentials);
      ast_cli_print_timestr_fromseconds(a->fd, ctimesec, buf);
      return CLI_SUCCESS;
   } else {
      ast_cli(a->fd, "Unable to connect %s%s\n", connection_info, credentials);
      return CLI_FAILURE;
   }
}

/* needs usecount semantics defined */
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "PostgreSQL RealTime Configuration Driver",
   .support_level = AST_MODULE_SUPPORT_EXTENDED,
   .load = load_module,
   .unload = unload_module,
   .reload = reload,
   .load_pri = AST_MODPRI_REALTIME_DRIVER,
   .requires = "extconfig",
);