Mon Apr 30 07:36:28 2007

Asterisk developer's documentation

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app_addon_sql_mysql.c

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/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Connect to MySQL
 * 
 * Copyright (C) 2004, Constantine Filin and Christos Ricudis
 *
 * Christos Ricudis <ricudis@itc.auth.gr>
 * Constantine Filin <cf@intermedia.net>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */
/*** MODULEINFO
   <depend>mysqlclient</depend>
 ***/

#include <asterisk.h>

#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <sys/types.h>
#include <stdio.h>
#include <unistd.h>

#include <mysql/mysql.h>

#include <asterisk/file.h>
#include <asterisk/logger.h>
#include <asterisk/channel.h>
#include <asterisk/pbx.h>
#include <asterisk/module.h>
#include <asterisk/linkedlists.h>
#include <asterisk/chanvars.h>
#include <asterisk/lock.h>

#define AST_MODULE "app_addon_sql_mysql"

#define EXTRA_LOG 0

static char *app = "MYSQL";

static char *synopsis = "Do several mySQLy things";

static char *descrip = 
"MYSQL():  Do several mySQLy things\n"
"Syntax:\n"
"  MYSQL(Connect connid dhhost dbuser dbpass dbname)\n"
"    Connects to a database.  Arguments contain standard MySQL parameters\n"
"    passed to function mysql_real_connect.  Connection identifer returned\n"
"    in ${var}\n"
"  MYSQL(Query resultid ${connid} query-string)\n"
"    Executes standard MySQL query contained in query-string using established\n"
"    connection identified by ${connection_identifier}. Result of query is\n"
"    is stored in ${var}.\n"
"  MYSQL(Fetch fetchid ${resultid} var1 var2 ... varN)\n"
"    Fetches a single row from a result set contained in ${result_identifier}.\n"
"    Assigns returned fields to ${var1} ... ${varn}.  ${fetchid} is set TRUE\n"
"    if additional rows exist in result set.\n"
"  MYSQL(Clear ${resultid})\n"
"    Frees memory and datastructures associated with result set.\n" 
"  MYSQL(Disconnect ${connid})\n"
"    Disconnects from named connection to MySQL.\n"
"  On exit, always returns 0. Sets MYSQL_STATUS to 0 on success and -1 on error.\n";

/* 
EXAMPLES OF USE : 

exten => s,2,MYSQL(Connect connid localhost asterisk mypass credit)
exten => s,3,MYSQL(Query resultid ${connid} SELECT username,credit FROM credit WHERE callerid=${CALLERIDNUM})
exten => s,4,MYSQL(Fetch fetchid ${resultid} datavar1 datavar2)
exten => s,5,GotoIf(${fetchid}?6:8)
exten => s,6,Festival("User ${datavar1} currently has credit balance of ${datavar2} dollars.")  
exten => s,7,Goto(s,4)
exten => s,8,MYSQL(Clear ${resultid})
exten => s,9,MYSQL(Disconnect ${connid})
*/

AST_MUTEX_DEFINE_STATIC(_mysql_mutex);

#define AST_MYSQL_ID_DUMMY   0
#define AST_MYSQL_ID_CONNID  1
#define AST_MYSQL_ID_RESID   2
#define AST_MYSQL_ID_FETCHID 3

struct ast_MYSQL_id {
   int identifier_type; /* 0=dummy, 1=connid, 2=resultid */
   int identifier;
   void *data;
   AST_LIST_ENTRY(ast_MYSQL_id) entries;
} *ast_MYSQL_id;

AST_LIST_HEAD(MYSQLidshead,ast_MYSQL_id) _mysql_ids_head;

/* helpful procs */
static void *find_identifier(int identifier,int identifier_type) {
   struct MYSQLidshead *headp;
   struct ast_MYSQL_id *i;
   void *res=NULL;
   int found=0;
   
   headp=&_mysql_ids_head;
   
   if (AST_LIST_LOCK(headp)) {
      ast_log(LOG_WARNING,"Unable to lock identifiers list\n");
   } else {
      AST_LIST_TRAVERSE(headp,i,entries) {
         if ((i->identifier==identifier) && (i->identifier_type==identifier_type)) {
            found=1;
            res=i->data;
            break;
         }
      }
      if (!found) {
         ast_log(LOG_WARNING,"Identifier %d, identifier_type %d not found in identifier list\n",identifier,identifier_type);
      }
      AST_LIST_UNLOCK(headp);
   }
   
   return res;
}

static int add_identifier(int identifier_type,void *data) {
   struct ast_MYSQL_id *i,*j;
   struct MYSQLidshead *headp;
   int maxidentifier=0;
   
   headp=&_mysql_ids_head;
   i=NULL;
   j=NULL;
   
   if (AST_LIST_LOCK(headp)) {
      ast_log(LOG_WARNING,"Unable to lock identifiers list\n");
      return(-1);
   } else {
      i=malloc(sizeof(struct ast_MYSQL_id));
      AST_LIST_TRAVERSE(headp,j,entries) {
         if (j->identifier>maxidentifier) {
            maxidentifier=j->identifier;
         }
      }
      i->identifier=maxidentifier+1;
      i->identifier_type=identifier_type;
      i->data=data;
      AST_LIST_INSERT_HEAD(headp,i,entries);
      AST_LIST_UNLOCK(headp);
   }
   return i->identifier;
}

static int del_identifier(int identifier,int identifier_type) {
   struct ast_MYSQL_id *i;
   struct MYSQLidshead *headp;
   int found=0;
   
        headp=&_mysql_ids_head;
        
        if (AST_LIST_LOCK(headp)) {
      ast_log(LOG_WARNING,"Unable to lock identifiers list\n");
   } else {
      AST_LIST_TRAVERSE(headp,i,entries) {
         if ((i->identifier==identifier) && 
             (i->identifier_type==identifier_type)) {
            AST_LIST_REMOVE(headp,i,entries);
            free(i);
            found=1;
            break;
         }
      }
      AST_LIST_UNLOCK(headp);
   }
                   
   if (found==0) {
      ast_log(LOG_WARNING,"Could not find identifier %d, identifier_type %d in list to delete\n",identifier,identifier_type);
      return(-1);
   } else {
      return(0);
   }
}

static int set_asterisk_int(struct ast_channel *chan, char *varname, int id) {
   if( id>=0 ) {
      char s[100] = "";
      snprintf(s, sizeof(s)-1, "%d", id);
#if EXTRA_LOG
      ast_log(LOG_WARNING,"MYSQL: setting var '%s' to value '%s'\n",varname,s);
#endif
      pbx_builtin_setvar_helper(chan,varname,s);
   }
   return id;
}

static int add_identifier_and_set_asterisk_int(struct ast_channel *chan, char *varname, int identifier_type, void *data) {
   return set_asterisk_int(chan,varname,add_identifier(identifier_type,data));
}

static int safe_scan_int( char** data, char* delim, int def ) {
   char* end;
   int res = def;
   char* s = strsep(data,delim);
   if( s ) {
      res = strtol(s,&end,10);
      if (*end) res = def;  /* not an integer */
   }
   return res;
}

/* MYSQL operations */
static int aMYSQL_connect(struct ast_channel *chan, char *data) {
   
   MYSQL *mysql;

   char *connid_var;
   char *dbhost;
   char *dbuser;
   char *dbpass;
   char *dbname;
    
   strsep(&data," "); // eat the first token, we already know it :P 

   connid_var=strsep(&data," ");
   dbhost=strsep(&data," ");
   dbuser=strsep(&data," ");
   dbpass=strsep(&data," ");
   dbname=strsep(&data,"\n");
   
   if( connid_var && dbhost && dbuser && dbpass && dbname ) {
      mysql = mysql_init(NULL);
      if (mysql) {
         if (mysql_real_connect(mysql,dbhost,dbuser,dbpass,dbname,0,NULL,0)) {
            add_identifier_and_set_asterisk_int(chan,connid_var,AST_MYSQL_ID_CONNID,mysql);
            return 0;
         }
         else {
            ast_log(LOG_WARNING,"mysql_real_connect(mysql,%s,%s,dbpass,%s,...) failed\n",dbhost,dbuser,dbname);
         }
      }
      else {
         ast_log(LOG_WARNING,"myslq_init returned NULL\n");
      }
   }
   else {
      ast_log(LOG_WARNING,"MYSQL(connect is missing some arguments\n");
   }

   return -1;
}

static int aMYSQL_query(struct ast_channel *chan, char *data) {
   
   MYSQL       *mysql;
   MYSQL_RES   *mysqlres;

   char *resultid_var;
   int connid;
   char *querystring;

   strsep(&data," "); // eat the first token, we already know it :P 

   resultid_var = strsep(&data," ");
   connid       = safe_scan_int(&data," ",-1);
   querystring  = strsep(&data,"\n");

   if (resultid_var && (connid>=0) && querystring) {
      if ((mysql=find_identifier(connid,AST_MYSQL_ID_CONNID))!=NULL) {
         mysql_query(mysql,querystring);
         if ((mysqlres=mysql_use_result(mysql))!=NULL) {
            add_identifier_and_set_asterisk_int(chan,resultid_var,AST_MYSQL_ID_RESID,mysqlres);
            return 0;
         }
         else if( mysql_field_count(mysql)==0 ) {
            return 0;  // See http://dev.mysql.com/doc/mysql/en/mysql_field_count.html
         }
         else {
            ast_log(LOG_WARNING,"aMYSQL_query: mysql_store_result() failed on query %s\n",querystring);
         }
      }
      else {
         ast_log(LOG_WARNING,"aMYSQL_query: Invalid connection identifier %d passed in aMYSQL_query\n",connid);
      }
   }
   else {
      ast_log(LOG_WARNING,"aMYSQL_query: missing some arguments\n");
   }
   
   return -1;
}


static int aMYSQL_fetch(struct ast_channel *chan, char *data) {
   
   MYSQL_RES *mysqlres;
   MYSQL_ROW mysqlrow;

   char *fetchid_var,*s5,*s6;
   int resultid,numFields,j;
   
   strsep(&data," "); // eat the first token, we already know it :P 

   fetchid_var = strsep(&data," ");
   resultid    = safe_scan_int(&data," ",-1);

   if (fetchid_var && (resultid>=0) ) {
      if ((mysqlres=find_identifier(resultid,AST_MYSQL_ID_RESID))!=NULL) {
         /* Grab the next row */
         if ((mysqlrow=mysql_fetch_row(mysqlres))!=NULL) {
            numFields=mysql_num_fields(mysqlres);
            for (j=0;j<numFields;j++) {
               s5=strsep(&data," ");
               if (s5==NULL) {
                  ast_log(LOG_WARNING,"ast_MYSQL_fetch: More fields (%d) than variables (%d)\n",numFields,j);
                  break;
               }
               s6=mysqlrow[j];
               pbx_builtin_setvar_helper(chan,s5, s6 ? s6 : "NULL");
            }
#if EXTRA_LOG
            ast_log(LOG_WARNING,"ast_MYSQL_fetch: numFields=%d\n",numFields);
#endif
            set_asterisk_int(chan,fetchid_var,1); // try more rows
         } else {
#if EXTRA_LOG
            ast_log(LOG_WARNING,"ast_MYSQL_fetch : EOF\n");
#endif
            set_asterisk_int(chan,fetchid_var,0); // no more rows
         }
         return 0;
      }
      else {
         ast_log(LOG_WARNING,"aMYSQL_fetch: Invalid result identifier %d passed\n",resultid);
      }
   }
   else {
      ast_log(LOG_WARNING,"aMYSQL_fetch: missing some arguments\n");
   }

   return -1;
}

static int aMYSQL_clear(struct ast_channel *chan, char *data) {

   MYSQL_RES *mysqlres;

   int id;
   strsep(&data," "); // eat the first token, we already know it :P 
   id = safe_scan_int(&data," \n",-1);
   if ((mysqlres=find_identifier(id,AST_MYSQL_ID_RESID))==NULL) {
      ast_log(LOG_WARNING,"Invalid result identifier %d passed in aMYSQL_clear\n",id);
   } else {
      mysql_free_result(mysqlres);
      del_identifier(id,AST_MYSQL_ID_RESID);
   }

   return 0;
}

static int aMYSQL_disconnect(struct ast_channel *chan, char *data) {
   
   MYSQL *mysql;
   int id;
   strsep(&data," "); // eat the first token, we already know it :P 

   id = safe_scan_int(&data," \n",-1);
   if ((mysql=find_identifier(id,AST_MYSQL_ID_CONNID))==NULL) {
      ast_log(LOG_WARNING,"Invalid connection identifier %d passed in aMYSQL_disconnect\n",id);
   } else {
      mysql_close(mysql);
      del_identifier(id,AST_MYSQL_ID_CONNID);
   } 

   return 0;
}

static int MYSQL_exec(struct ast_channel *chan, void *data)
{
   struct ast_module_user *u;
   int result;
   char sresult[10];

#if EXTRA_LOG
   fprintf(stderr,"MYSQL_exec: data=%s\n",(char*)data);
#endif

   if (!data) {
      ast_log(LOG_WARNING, "APP_MYSQL requires an argument (see manual)\n");
      return -1;
   }

   u = ast_module_user_add(chan);
   result=0;

   ast_mutex_lock(&_mysql_mutex);

   if (strncasecmp("connect",data,strlen("connect"))==0) {
      result=aMYSQL_connect(chan,ast_strdupa(data));
   } else   if (strncasecmp("query",data,strlen("query"))==0) {
      result=aMYSQL_query(chan,ast_strdupa(data));
   } else   if (strncasecmp("fetch",data,strlen("fetch"))==0) {
      result=aMYSQL_fetch(chan,ast_strdupa(data));
   } else   if (strncasecmp("clear",data,strlen("clear"))==0) {
      result=aMYSQL_clear(chan,ast_strdupa(data));
   } else   if (strncasecmp("disconnect",data,strlen("disconnect"))==0) {
      result=aMYSQL_disconnect(chan,ast_strdupa(data));
   } else {
      ast_log(LOG_WARNING, "Unknown argument to MYSQL application : %s\n",(char *)data);
      result=-1;  
   }
      
   ast_mutex_unlock(&_mysql_mutex);

   ast_module_user_remove(u);
   snprintf(sresult, sizeof(sresult), "%d", result);
   pbx_builtin_setvar_helper(chan, "MYSQL_STATUS", sresult);
   return 0;
}

static int unload_module(void)
{
   ast_module_user_hangup_all();
   return ast_unregister_application(app);
}

static int load_module(void)
{
   struct MYSQLidshead *headp = &_mysql_ids_head;
   AST_LIST_HEAD_INIT(headp);
   return ast_register_application(app, MYSQL_exec, synopsis, descrip);
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Simple Mysql Interface");

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