Thu Jul 9 13:40:34 2009

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  * \extref Depends on the CURL library  - http://curl.haxx.se/
00029  * 
00030  * \ingroup functions
00031  */
00032  
00033 /*** MODULEINFO
00034    <depend>curl</depend>
00035  ***/
00036 
00037 #include "asterisk.h"
00038 
00039 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 134542 $")
00040 
00041 #include <curl/curl.h>
00042 
00043 #include "asterisk/lock.h"
00044 #include "asterisk/file.h"
00045 #include "asterisk/channel.h"
00046 #include "asterisk/pbx.h"
00047 #include "asterisk/cli.h"
00048 #include "asterisk/module.h"
00049 #include "asterisk/app.h"
00050 #include "asterisk/utils.h"
00051 #include "asterisk/threadstorage.h"
00052 
00053 struct MemoryStruct {
00054    char *memory;
00055    size_t size;
00056 };
00057 
00058 /* There might be a realloc() out there that doesn't like reallocing
00059  * NULL pointers, so we take care of it here
00060  */
00061 static void *myrealloc(void *ptr, size_t size)
00062 {
00063    return (ptr ? ast_realloc(ptr, size) : ast_malloc(size));
00064 }
00065 
00066 static size_t WriteMemoryCallback(void *ptr, size_t size, size_t nmemb, void *data)
00067 {
00068    register int realsize = size * nmemb;
00069    struct MemoryStruct *mem = (struct MemoryStruct *)data;
00070 
00071    if ((mem->memory = (char *)myrealloc(mem->memory, mem->size + realsize + 1))) {
00072       memcpy(&(mem->memory[mem->size]), ptr, realsize);
00073       mem->size += realsize;
00074       mem->memory[mem->size] = 0;
00075    }
00076 
00077    return realsize;
00078 }
00079 
00080 static const char *global_useragent = "asterisk-libcurl-agent/1.0";
00081 
00082 static int curl_instance_init(void *data)
00083 {
00084    CURL **curl = data;
00085 
00086    if (!(*curl = curl_easy_init()))
00087       return -1;
00088 
00089    curl_easy_setopt(*curl, CURLOPT_NOSIGNAL, 1);
00090    curl_easy_setopt(*curl, CURLOPT_TIMEOUT, 180);
00091    curl_easy_setopt(*curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
00092    curl_easy_setopt(*curl, CURLOPT_USERAGENT, global_useragent);
00093 
00094    return 0;
00095 }
00096 
00097 static void curl_instance_cleanup(void *data)
00098 {
00099    CURL **curl = data;
00100 
00101    curl_easy_cleanup(*curl);
00102 
00103    ast_free(data);
00104 }
00105 
00106 AST_THREADSTORAGE_CUSTOM(curl_instance, curl_instance_init, curl_instance_cleanup);
00107 
00108 static int curl_internal(struct MemoryStruct *chunk, char *url, char *post)
00109 {
00110    CURL **curl;
00111 
00112    if (!(curl = ast_threadstorage_get(&curl_instance, sizeof(*curl))))
00113       return -1;
00114 
00115    curl_easy_setopt(*curl, CURLOPT_URL, url);
00116    curl_easy_setopt(*curl, CURLOPT_WRITEDATA, (void *) chunk);
00117 
00118    if (post) {
00119       curl_easy_setopt(*curl, CURLOPT_POST, 1);
00120       curl_easy_setopt(*curl, CURLOPT_POSTFIELDS, post);
00121    }
00122 
00123    curl_easy_perform(*curl);
00124 
00125    if (post)
00126       curl_easy_setopt(*curl, CURLOPT_POST, 0);
00127 
00128    return 0;
00129 }
00130 
00131 static int acf_curl_exec(struct ast_channel *chan, const char *cmd, char *info, char *buf, size_t len)
00132 {
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    AST_STANDARD_APP_ARGS(args, info);  
00147 
00148    if (chan)
00149       ast_autoservice_start(chan);
00150 
00151    if (!curl_internal(&chunk, args.url, args.postdata)) {
00152       if (chunk.memory) {
00153          chunk.memory[chunk.size] = '\0';
00154          if (chunk.memory[chunk.size - 1] == 10)
00155             chunk.memory[chunk.size - 1] = '\0';
00156 
00157          ast_copy_string(buf, chunk.memory, len);
00158          ast_free(chunk.memory);
00159       }
00160    } else {
00161       ast_log(LOG_ERROR, "Cannot allocate curl structure\n");
00162    }
00163 
00164    if (chan)
00165       ast_autoservice_stop(chan);
00166    
00167    return 0;
00168 }
00169 
00170 struct ast_custom_function acf_curl = {
00171    .name = "CURL",
00172    .synopsis = "Retrieves the contents of a URL",
00173    .syntax = "CURL(url[,post-data])",
00174    .desc =
00175    "  url       - URL to retrieve\n"
00176    "  post-data - Optional data to send as a POST (GET is default action)\n",
00177    .read = acf_curl_exec,
00178 };
00179 
00180 static int unload_module(void)
00181 {
00182    int res;
00183 
00184    res = ast_custom_function_unregister(&acf_curl);
00185 
00186    curl_global_cleanup();
00187    
00188    return res;
00189 }
00190 
00191 static int load_module(void)
00192 {
00193    int res;
00194 
00195    if (curl_global_init(CURL_GLOBAL_ALL)) {
00196       ast_log(LOG_ERROR, "Unable to initialize the CURL library. Cannot load func_curl\n");
00197       return AST_MODULE_LOAD_DECLINE;
00198    }  
00199 
00200    res = ast_custom_function_register(&acf_curl);
00201 
00202    return res;
00203 }
00204 
00205 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Load external URL");
00206 

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