Mon Nov 24 15:34:18 2008

Asterisk developer's documentation


func_curl.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C)  2004 - 2006, Tilghman Lesher
00005  *
00006  * Tilghman Lesher <curl-20050919@the-tilghman.com>
00007  * and Brian Wilkins <bwilkins@cfl.rr.com> (Added POST option)
00008  *
00009  * app_curl.c is distributed with no restrictions on usage or
00010  * redistribution.
00011  *
00012  * See http://www.asterisk.org for more information about
00013  * the Asterisk project. Please do not directly contact
00014  * any of the maintainers of this project for assistance;
00015  * the project provides a web site, mailing lists and IRC
00016  * channels for your use.
00017  *
00018  */
00019 
00020 /*! \file
00021  * 
00022  * \brief Curl - Load a URL
00023  *
00024  * \author Tilghman Lesher <curl-20050919@the-tilghman.com>
00025  *
00026  * \note Brian Wilkins <bwilkins@cfl.rr.com> (Added POST option) 
00027  * 
00028  * \ingroup functions
00029  */
00030  
00031 /*** MODULEINFO
00032    <depend>curl</depend>
00033  ***/
00034 
00035 #include "asterisk.h"
00036 
00037 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 134540 $")
00038 
00039 #include <stdio.h>
00040 #include <stdlib.h>
00041 #include <string.h>
00042 #include <curl/curl.h>
00043 
00044 #include "asterisk/lock.h"
00045 #include "asterisk/file.h"
00046 #include "asterisk/logger.h"
00047 #include "asterisk/channel.h"
00048 #include "asterisk/pbx.h"
00049 #include "asterisk/cli.h"
00050 #include "asterisk/options.h"
00051 #include "asterisk/module.h"
00052 #include "asterisk/app.h"
00053 #include "asterisk/utils.h"
00054 #include "asterisk/threadstorage.h"
00055 
00056 struct MemoryStruct {
00057    char *memory;
00058    size_t size;
00059 };
00060 
00061 static void *myrealloc(void *ptr, size_t size)
00062 {
00063    /* There might be a realloc() out there that doesn't like reallocing
00064       NULL pointers, so we take care of it here */
00065    if (ptr)
00066       return ast_realloc(ptr, size);
00067    else
00068       return ast_malloc(size);
00069 }
00070 
00071 static size_t WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *data)
00072 {
00073    register int realsize = size * nmemb;
00074    struct MemoryStruct *mem = (struct MemoryStruct *)data;
00075 
00076    mem->memory = (char *)myrealloc(mem->memory, mem->size + realsize + 1);
00077    if (mem->memory) {
00078       memcpy(&(mem->memory[mem->size]), ptr, realsize);
00079       mem->size += realsize;
00080       mem->memory[mem->size] = 0;
00081    }
00082    return realsize;
00083 }
00084 
00085 static const char *global_useragent = "asterisk-libcurl-agent/1.0";
00086 
00087 static void curl_instance_cleanup(void *data)
00088 {
00089    CURL **curl = data;
00090 
00091    curl_easy_cleanup(*curl);
00092 
00093    free(data);
00094 }
00095 
00096 AST_THREADSTORAGE_CUSTOM(curl_instance, curl_instance_init, curl_instance_cleanup);
00097 
00098 static int curl_internal(struct MemoryStruct *chunk, char *url, char *post)
00099 {
00100    CURL **curl;
00101 
00102    if (!(curl = ast_threadstorage_get(&curl_instance, sizeof(*curl))))
00103       return -1;
00104 
00105    if (!*curl) {
00106       if (!(*curl = curl_easy_init()))
00107          return -1;
00108       curl_easy_setopt(*curl, CURLOPT_NOSIGNAL, 1);
00109       curl_easy_setopt(*curl, CURLOPT_TIMEOUT, 180);
00110       curl_easy_setopt(*curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
00111       curl_easy_setopt(*curl, CURLOPT_USERAGENT, global_useragent);
00112    }
00113 
00114    curl_easy_setopt(*curl, CURLOPT_URL, url);
00115    curl_easy_setopt(*curl, CURLOPT_WRITEDATA, (void *) chunk);
00116 
00117    if (post) {
00118       curl_easy_setopt(*curl, CURLOPT_POST, 1);
00119       curl_easy_setopt(*curl, CURLOPT_POSTFIELDS, post);
00120    }
00121 
00122    curl_easy_perform(*curl);
00123 
00124    if (post)
00125       curl_easy_setopt(*curl, CURLOPT_POST, 0);
00126 
00127    return 0;
00128 }
00129 
00130 static int acf_curl_exec(struct ast_channel *chan, char *cmd, char *info, char *buf, size_t len)
00131 {
00132    struct ast_module_user *u;
00133    struct MemoryStruct chunk = { NULL, 0 };
00134    AST_DECLARE_APP_ARGS(args,
00135       AST_APP_ARG(url);
00136       AST_APP_ARG(postdata);
00137    );
00138 
00139    *buf = '\0';
00140    
00141    if (ast_strlen_zero(info)) {
00142       ast_log(LOG_WARNING, "CURL requires an argument (URL)\n");
00143       return -1;
00144    }
00145 
00146    u = ast_module_user_add(chan);
00147 
00148    AST_STANDARD_APP_ARGS(args, info);  
00149 
00150    if (chan)
00151       ast_autoservice_start(chan);
00152 
00153    if (!curl_internal(&chunk, args.url, args.postdata)) {
00154       if (chunk.memory) {
00155          chunk.memory[chunk.size] = '\0';
00156          if (chunk.memory[chunk.size - 1] == 10)
00157             chunk.memory[chunk.size - 1] = '\0';
00158 
00159          ast_copy_string(buf, chunk.memory, len);
00160          free(chunk.memory);
00161       }
00162    } else {
00163       ast_log(LOG_ERROR, "Cannot allocate curl structure\n");
00164    }
00165 
00166    if (chan)
00167       ast_autoservice_stop(chan);
00168 
00169    ast_module_user_remove(u);
00170 
00171    return 0;
00172 }
00173 
00174 struct ast_custom_function acf_curl = {
00175    .name = "CURL",
00176    .synopsis = "Retrieves the contents of a URL",
00177    .syntax = "CURL(url[|post-data])",
00178    .desc =
00179    "  url       - URL to retrieve\n"
00180    "  post-data - Optional data to send as a POST (GET is default action)\n",
00181    .read = acf_curl_exec,
00182 };
00183 
00184 static int unload_module(void)
00185 {
00186    int res;
00187 
00188    res = ast_custom_function_unregister(&acf_curl);
00189 
00190    ast_module_user_hangup_all();
00191 
00192    curl_global_cleanup();
00193    
00194    return res;
00195 }
00196 
00197 static int load_module(void)
00198 {
00199    int res;
00200 
00201    if (curl_global_init(CURL_GLOBAL_ALL)) {
00202       ast_log(LOG_ERROR, "Unable to initialize the CURL library. Cannot load func_curl\n");
00203       return AST_MODULE_LOAD_DECLINE;
00204    }  
00205 
00206    res = ast_custom_function_register(&acf_curl);
00207 
00208    return res;
00209 }
00210 
00211 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Load external URL");
00212 

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