cdr_tds.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 2004 - 2006, Digium, Inc.
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*!
 * \file
 * \brief FreeTDS CDR logger
 *
 * See also
 * \arg \ref Config_cdr
 * \arg http://www.freetds.org/
 * \ingroup cdr_drivers
 */

/*!
 * \verbatim
 *
 * Table Structure for `cdr`
 *
 * Created on: 05/20/2004 16:16
 * Last changed on: 07/27/2004 20:01

CREATE TABLE [dbo].[cdr] (
   [accountcode] [varchar] (20) NULL ,
   [src] [varchar] (80) NULL ,
   [dst] [varchar] (80) NULL ,
   [dcontext] [varchar] (80) NULL ,
   [clid] [varchar] (80) NULL ,
   [channel] [varchar] (80) NULL ,
   [dstchannel] [varchar] (80) NULL ,
   [lastapp] [varchar] (80) NULL ,
   [lastdata] [varchar] (80) NULL ,
   [start] [datetime] NULL ,
   [answer] [datetime] NULL ,
   [end] [datetime] NULL ,
   [duration] [int] NULL ,
   [billsec] [int] NULL ,
   [disposition] [varchar] (20) NULL ,
   [amaflags] [varchar] (16) NULL ,
   [uniqueid] [varchar] (32) NULL ,
   [userfield] [varchar] (256) NULL
) ON [PRIMARY]

\endverbatim

*/

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

#include "asterisk.h"

#include "asterisk/config.h"
#include "asterisk/channel.h"
#include "asterisk/cdr.h"
#include "asterisk/module.h"

#include <sqlfront.h>
#include <sybdb.h>

#define DATE_FORMAT "%Y/%m/%d %T"

static const char name[] = "FreeTDS (MSSQL)";
static const char config[] = "cdr_tds.conf";

struct cdr_tds_config {
   AST_DECLARE_STRING_FIELDS(
      AST_STRING_FIELD(hostname);
      AST_STRING_FIELD(database);
      AST_STRING_FIELD(username);
      AST_STRING_FIELD(password);
      AST_STRING_FIELD(table);
      AST_STRING_FIELD(charset);
      AST_STRING_FIELD(language);
      AST_STRING_FIELD(hrtime);
   );
   DBPROCESS *dbproc;
   unsigned int connected:1;
   unsigned int has_userfield:1;
};

AST_MUTEX_DEFINE_STATIC(tds_lock);

static struct cdr_tds_config *settings;

static char *anti_injection(const char *, int);
static void get_date(char *, size_t len, struct timeval);

static int execute_and_consume(DBPROCESS *dbproc, const char *fmt, ...)
   __attribute__((format(printf, 2, 3)));

static int mssql_connect(void);
static int mssql_disconnect(void);

static int tds_log(struct ast_cdr *cdr)
{
   char start[80], answer[80], end[80];
   char *accountcode, *src, *dst, *dcontext, *clid, *channel, *dstchannel, *lastapp, *lastdata, *uniqueid, *userfield = NULL;
   RETCODE erc;
   int res = -1;
   int attempt = 1;

   accountcode = anti_injection(cdr->accountcode, 20);
   src         = anti_injection(cdr->src, 80);
   dst         = anti_injection(cdr->dst, 80);
   dcontext    = anti_injection(cdr->dcontext, 80);
   clid        = anti_injection(cdr->clid, 80);
   channel     = anti_injection(cdr->channel, 80);
   dstchannel  = anti_injection(cdr->dstchannel, 80);
   lastapp     = anti_injection(cdr->lastapp, 80);
   lastdata    = anti_injection(cdr->lastdata, 80);
   uniqueid    = anti_injection(cdr->uniqueid, 32);

   get_date(start, sizeof(start), cdr->start);
   get_date(answer, sizeof(answer), cdr->answer);
   get_date(end, sizeof(end), cdr->end);

   ast_mutex_lock(&tds_lock);

   if (settings->has_userfield) {
      userfield = anti_injection(cdr->userfield, AST_MAX_USER_FIELD);
   }

retry:
   /* Ensure that we are connected */
   if (!settings->connected) {
      ast_log(LOG_NOTICE, "Attempting to reconnect to %s (Attempt %d)\n", settings->hostname, attempt);
      if (mssql_connect()) {
         /* Connect failed */
         if (attempt++ < 3) {
            goto retry;
         }
         goto done;
      }
   }

   if (settings->has_userfield) {
      if (settings->hrtime) {
         double hrbillsec = 0.0;
         double hrduration;

         if (!ast_tvzero(cdr->answer)) {
            hrbillsec = (double)(ast_tvdiff_us(cdr->end, cdr->answer) / 1000000.0);
         }
         hrduration = (double)(ast_tvdiff_us(cdr->end, cdr->start) / 1000000.0);

         erc = dbfcmd(settings->dbproc,
                "INSERT INTO %s "
                "("
                "accountcode, src, dst, dcontext, clid, channel, "
                "dstchannel, lastapp, lastdata, start, answer, [end], duration, "
                "billsec, disposition, amaflags, uniqueid, userfield"
                ") "
                "VALUES "
                "("
                "'%s', '%s', '%s', '%s', '%s', '%s', "
                "'%s', '%s', '%s', %s, %s, %s, %lf, "
                "%lf, '%s', '%s', '%s', '%s'"
                ")",
                settings->table,
                accountcode, src, dst, dcontext, clid, channel,
                dstchannel, lastapp, lastdata, start, answer, end, hrduration,
                hrbillsec, ast_cdr_disp2str(cdr->disposition), ast_channel_amaflags2string(cdr->amaflags), uniqueid,
                userfield
         );
      } else {
         erc = dbfcmd(settings->dbproc,
                "INSERT INTO %s "
                "("
                "accountcode, src, dst, dcontext, clid, channel, "
                "dstchannel, lastapp, lastdata, start, answer, [end], duration, "
                "billsec, disposition, amaflags, uniqueid, userfield"
                ") "
                "VALUES "
                "("
                "'%s', '%s', '%s', '%s', '%s', '%s', "
                "'%s', '%s', '%s', %s, %s, %s, %ld, "
                "%ld, '%s', '%s', '%s', '%s'"
                ")",
                settings->table,
                accountcode, src, dst, dcontext, clid, channel,
                dstchannel, lastapp, lastdata, start, answer, end, cdr->duration,
                cdr->billsec, ast_cdr_disp2str(cdr->disposition), ast_channel_amaflags2string(cdr->amaflags), uniqueid,
                userfield
         );
      }
   } else {
      if (settings->hrtime) {
         double hrbillsec = 0.0;
         double hrduration;

         if (!ast_tvzero(cdr->answer)) {
            hrbillsec = (double)(ast_tvdiff_us(cdr->end, cdr->answer) / 1000000.0);
         }
         hrduration = (double)(ast_tvdiff_us(cdr->end, cdr->start) / 1000000.0);

         erc = dbfcmd(settings->dbproc,
                "INSERT INTO %s "
                "("
                "accountcode, src, dst, dcontext, clid, channel, "
                "dstchannel, lastapp, lastdata, start, answer, [end], duration, "
                "billsec, disposition, amaflags, uniqueid"
                ") "
                "VALUES "
                "("
                "'%s', '%s', '%s', '%s', '%s', '%s', "
                "'%s', '%s', '%s', %s, %s, %s, %lf, "
                "%lf, '%s', '%s', '%s'"
                ")",
                settings->table,
                accountcode, src, dst, dcontext, clid, channel,
                dstchannel, lastapp, lastdata, start, answer, end, hrduration,
                hrbillsec, ast_cdr_disp2str(cdr->disposition), ast_channel_amaflags2string(cdr->amaflags), uniqueid
         );
      } else {
         erc = dbfcmd(settings->dbproc,
                "INSERT INTO %s "
                "("
                "accountcode, src, dst, dcontext, clid, channel, "
                "dstchannel, lastapp, lastdata, start, answer, [end], duration, "
                "billsec, disposition, amaflags, uniqueid"
                ") "
                "VALUES "
                "("
                "'%s', '%s', '%s', '%s', '%s', '%s', "
                "'%s', '%s', '%s', %s, %s, %s, %ld, "
                "%ld, '%s', '%s', '%s'"
                ")",
                settings->table,
                accountcode, src, dst, dcontext, clid, channel,
                dstchannel, lastapp, lastdata, start, answer, end, cdr->duration,
                cdr->billsec, ast_cdr_disp2str(cdr->disposition), ast_channel_amaflags2string(cdr->amaflags), uniqueid
         );
      }
   }

   if (erc == FAIL) {
      if (attempt++ < 3) {
         ast_log(LOG_NOTICE, "Failed to build INSERT statement, retrying...\n");
         mssql_disconnect();
         goto retry;
      } else {
         ast_log(LOG_ERROR, "Failed to build INSERT statement, no CDR was logged.\n");
         goto done;
      }
   }

   if (dbsqlexec(settings->dbproc) == FAIL) {
      if (attempt++ < 3) {
         ast_log(LOG_NOTICE, "Failed to execute INSERT statement, retrying...\n");
         mssql_disconnect();
         goto retry;
      } else {
         ast_log(LOG_ERROR, "Failed to execute INSERT statement, no CDR was logged.\n");
         goto done;
      }
   }

   /* Consume any results we might get back (this is more of a sanity check than
    * anything else, since an INSERT shouldn't return results). */
   while (dbresults(settings->dbproc) != NO_MORE_RESULTS) {
      while (dbnextrow(settings->dbproc) != NO_MORE_ROWS);
   }

   res = 0;

done:
   ast_mutex_unlock(&tds_lock);

   ast_free(accountcode);
   ast_free(src);
   ast_free(dst);
   ast_free(dcontext);
   ast_free(clid);
   ast_free(channel);
   ast_free(dstchannel);
   ast_free(lastapp);
   ast_free(lastdata);
   ast_free(uniqueid);

   if (userfield) {
      ast_free(userfield);
   }

   return res;
}

static char *anti_injection(const char *str, int len)
{
   /* Reference to http://www.nextgenss.com/papers/advanced_sql_injection.pdf */
   char *buf;
   char *buf_ptr, *srh_ptr;
   char *known_bad[] = {"select", "insert", "update", "delete", "drop", ";", "--", "\0"};
   int idx;

   if (!(buf = ast_calloc(1, len + 1))) {
      ast_log(LOG_ERROR, "Out of memory\n");
      return NULL;
   }

   buf_ptr = buf;

   /* Escape single quotes */
   for (; *str && strlen(buf) < len; str++) {
      if (*str == '\'') {
         *buf_ptr++ = '\'';
      }
      *buf_ptr++ = *str;
   }
   *buf_ptr = '\0';

   /* Erase known bad input */
   for (idx = 0; *known_bad[idx]; idx++) {
      while ((srh_ptr = strcasestr(buf, known_bad[idx]))) {
         memmove(srh_ptr, srh_ptr + strlen(known_bad[idx]), strlen(srh_ptr + strlen(known_bad[idx])) + 1);
      }
   }

   return buf;
}

static void get_date(char *dateField, size_t len, struct timeval when)
{
   /* To make sure we have date variable if not insert null to SQL */
   if (!ast_tvzero(when)) {
      struct ast_tm tm;
      ast_localtime(&when, &tm, NULL);
      ast_strftime(dateField, len, "'" DATE_FORMAT "'", &tm);
   } else {
      ast_copy_string(dateField, "null", len);
   }
}

static int execute_and_consume(DBPROCESS *dbproc, const char *fmt, ...)
{
   va_list ap;
   char *buffer;

   va_start(ap, fmt);
   if (ast_vasprintf(&buffer, fmt, ap) < 0) {
      va_end(ap);
      return 1;
   }
   va_end(ap);

   if (dbfcmd(dbproc, buffer) == FAIL) {
      ast_free(buffer);
      return 1;
   }

   ast_free(buffer);

   if (dbsqlexec(dbproc) == FAIL) {
      return 1;
   }

   /* Consume the result set (we don't really care about the result, though) */
   while (dbresults(dbproc) != NO_MORE_RESULTS) {
      while (dbnextrow(dbproc) != NO_MORE_ROWS);
   }

   return 0;
}

static int mssql_disconnect(void)
{
   if (settings->dbproc) {
      dbclose(settings->dbproc);
      settings->dbproc = NULL;
   }

   settings->connected = 0;

   return 0;
}

static int mssql_connect(void)
{
   LOGINREC *login;

   if ((login = dblogin()) == NULL) {
      ast_log(LOG_ERROR, "Unable to allocate login structure for db-lib\n");
      return -1;
   }

   DBSETLAPP(login,     "TSQL");
   DBSETLUSER(login,    (char *) settings->username);
   DBSETLPWD(login,     (char *) settings->password);
   DBSETLCHARSET(login, (char *) settings->charset);
   DBSETLNATLANG(login, (char *) settings->language);

   if ((settings->dbproc = dbopen(login, (char *) settings->hostname)) == NULL) {
      ast_log(LOG_ERROR, "Unable to connect to %s\n", settings->hostname);
      dbloginfree(login);
      return -1;
   }

   dbloginfree(login);

   if (dbuse(settings->dbproc, (char *) settings->database) == FAIL) {
      ast_log(LOG_ERROR, "Unable to select database %s\n", settings->database);
      goto failed;
   }

   if (execute_and_consume(settings->dbproc, "SELECT 1 FROM [%s] WHERE 1 = 0", settings->table)) {
      ast_log(LOG_ERROR, "Unable to find table '%s'\n", settings->table);
      goto failed;
   }

   /* Check to see if we have a userfield column in the table */
   if (execute_and_consume(settings->dbproc, "SELECT userfield FROM [%s] WHERE 1 = 0", settings->table)) {
      ast_log(LOG_NOTICE, "Unable to find 'userfield' column in table '%s'\n", settings->table);
      settings->has_userfield = 0;
   } else {
      settings->has_userfield = 1;
   }

   settings->connected = 1;

   return 0;

failed:
   dbclose(settings->dbproc);
   settings->dbproc = NULL;
   return -1;
}

static int tds_unload_module(void)
{
   if (ast_cdr_unregister(name)) {
      return -1;
   }

   if (settings) {
      ast_mutex_lock(&tds_lock);
      mssql_disconnect();
      ast_mutex_unlock(&tds_lock);

      ast_string_field_free_memory(settings);
      ast_free(settings);
   }

   dbexit();

   return 0;
}

static int tds_error_handler(DBPROCESS *dbproc, int severity, int dberr, int oserr, char *dberrstr, char *oserrstr)
{
   ast_log(LOG_ERROR, "%s (%d)\n", dberrstr, dberr);

   if (oserr != DBNOERR) {
      ast_log(LOG_ERROR, "%s (%d)\n", oserrstr, oserr);
   }

   return INT_CANCEL;
}

static int tds_message_handler(DBPROCESS *dbproc, DBINT msgno, int msgstate, int severity, char *msgtext, char *srvname, char *procname, int line)
{
   ast_debug(1, "Msg %d, Level %d, State %d, Line %d\n", msgno, severity, msgstate, line);
   ast_log(LOG_NOTICE, "%s\n", msgtext);

   return 0;
}

static int tds_load_module(int reload)
{
   struct ast_config *cfg;
   const char *ptr = NULL;
   struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };

   cfg = ast_config_load(config, config_flags);
   if (!cfg || cfg == CONFIG_STATUS_FILEINVALID) {
      ast_log(LOG_NOTICE, "Unable to load TDS config for CDRs: %s\n", config);
      return 0;
   } else if (cfg == CONFIG_STATUS_FILEUNCHANGED)
      return 0;

   if (!ast_variable_browse(cfg, "global")) {
      /* nothing configured */
      ast_config_destroy(cfg);
      return 0;
   }

   ast_mutex_lock(&tds_lock);

   /* Clear out any existing settings */
   ast_string_field_init(settings, 0);

   /* 'connection' is the new preferred configuration option */
   ptr = ast_variable_retrieve(cfg, "global", "connection");
   if (ptr) {
      ast_string_field_set(settings, hostname, ptr);
   } else {
      /* But we keep 'hostname' for backwards compatibility */
      ptr = ast_variable_retrieve(cfg, "global", "hostname");
      if (ptr) {
         ast_string_field_set(settings, hostname, ptr);
      } else {
         ast_log(LOG_ERROR, "Failed to connect: Database server connection not specified.\n");
         goto failed;
      }
   }

   ptr = ast_variable_retrieve(cfg, "global", "dbname");
   if (ptr) {
      ast_string_field_set(settings, database, ptr);
   } else {
      ast_log(LOG_ERROR, "Failed to connect: Database dbname not specified.\n");
      goto failed;
   }

   ptr = ast_variable_retrieve(cfg, "global", "user");
   if (ptr) {
      ast_string_field_set(settings, username, ptr);
   } else {
      ast_log(LOG_ERROR, "Failed to connect: Database dbuser not specified.\n");
      goto failed;
   }

   ptr = ast_variable_retrieve(cfg, "global", "password");
   if (ptr) {
      ast_string_field_set(settings, password, ptr);
   } else {
      ast_log(LOG_ERROR, "Failed to connect: Database password not specified.\n");
      goto failed;
   }

   ptr = ast_variable_retrieve(cfg, "global", "charset");
   if (ptr) {
      ast_string_field_set(settings, charset, ptr);
   } else {
      ast_string_field_set(settings, charset, "iso_1");
   }

   ptr = ast_variable_retrieve(cfg, "global", "language");
   if (ptr) {
      ast_string_field_set(settings, language, ptr);
   } else {
      ast_string_field_set(settings, language, "us_english");
   }

   ptr = ast_variable_retrieve(cfg, "global", "table");
   if (ptr) {
      ast_string_field_set(settings, table, ptr);
   } else {
      ast_log(LOG_NOTICE, "Table name not specified, using 'cdr' by default.\n");
      ast_string_field_set(settings, table, "cdr");
   }

   ptr = ast_variable_retrieve(cfg, "global", "hrtime");
   if (ptr && ast_true(ptr)) {
      ast_string_field_set(settings, hrtime, ptr);
   } else {
      ast_log(LOG_NOTICE, "High Resolution Time not found, using integers for billsec and duration fields by default.\n");
   }

   mssql_disconnect();

   if (mssql_connect()) {
      /* We failed to connect (mssql_connect takes care of logging it) */
      goto failed;
   }

   ast_mutex_unlock(&tds_lock);
   ast_config_destroy(cfg);

   return 1;

failed:
   ast_mutex_unlock(&tds_lock);
   ast_config_destroy(cfg);

   return 0;
}

static int reload(void)
{
   return tds_load_module(1);
}

static int load_module(void)
{
   if (dbinit() == FAIL) {
      ast_log(LOG_ERROR, "Failed to initialize FreeTDS db-lib\n");
      return AST_MODULE_LOAD_DECLINE;
   }

   dberrhandle(tds_error_handler);
   dbmsghandle(tds_message_handler);

   settings = ast_calloc_with_stringfields(1, struct cdr_tds_config, 256);

   if (!settings) {
      dbexit();
      return AST_MODULE_LOAD_DECLINE;
   }

   if (!tds_load_module(0)) {
      ast_string_field_free_memory(settings);
      ast_free(settings);
      settings = NULL;
      dbexit();
      return AST_MODULE_LOAD_DECLINE;
   }

   ast_cdr_register(name, ast_module_info->description, tds_log);

   return AST_MODULE_LOAD_SUCCESS;
}

static int unload_module(void)
{
   return tds_unload_module();
}

AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_LOAD_ORDER, "FreeTDS CDR Backend",
   .support_level = AST_MODULE_SUPPORT_EXTENDED,
   .load = load_module,
   .unload = unload_module,
   .reload = reload,
   .load_pri = AST_MODPRI_CDR_DRIVER,
   .requires = "cdr",
);