1/*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al. 9 * 10 * This software is licensed as described in the file COPYING, which 11 * you should have received as part of this distribution. The terms 12 * are also available at https://curl.haxx.se/docs/copyright.html. 13 * 14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 15 * copies of the Software, and permit persons to whom the Software is 16 * furnished to do so, under the terms of the COPYING file. 17 * 18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 19 * KIND, either express or implied. 20 * 21 ***************************************************************************/ 22/* <DESC> 23 * multi socket API usage with libevent 2 24 * </DESC> 25 */ 26/* Example application source code using the multi socket interface to 27 download many files at once. 28 29Written by Jeff Pohlmeyer 30 31Requires libevent version 2 and a (POSIX?) system that has mkfifo(). 32 33This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c" 34sample programs. 35 36When running, the program creates the named pipe "hiper.fifo" 37 38Whenever there is input into the fifo, the program reads the input as a list 39of URL's and creates some new easy handles to fetch each URL via the 40curl_multi "hiper" API. 41 42 43Thus, you can try a single URL: 44 % echo http://www.yahoo.com > hiper.fifo 45 46Or a whole bunch of them: 47 % cat my-url-list > hiper.fifo 48 49The fifo buffer is handled almost instantly, so you can even add more URL's 50while the previous requests are still being downloaded. 51 52Note: 53 For the sake of simplicity, URL length is limited to 1023 char's ! 54 55This is purely a demo app, all retrieved data is simply discarded by the write 56callback. 57 58*/ 59 60#include <stdio.h> 61#include <string.h> 62#include <stdlib.h> 63#include <sys/time.h> 64#include <time.h> 65#include <unistd.h> 66#include <sys/poll.h> 67#include <curl/curl.h> 68#include <event2/event.h> 69#include <fcntl.h> 70#include <sys/stat.h> 71#include <errno.h> 72 73 74#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */ 75 76 77/* Global information, common to all connections */ 78typedef struct _GlobalInfo 79{ 80 struct event_base *evbase; 81 struct event *fifo_event; 82 struct event *timer_event; 83 CURLM *multi; 84 int still_running; 85 FILE* input; 86} GlobalInfo; 87 88 89/* Information associated with a specific easy handle */ 90typedef struct _ConnInfo 91{ 92 CURL *easy; 93 char *url; 94 GlobalInfo *global; 95 char error[CURL_ERROR_SIZE]; 96} ConnInfo; 97 98 99/* Information associated with a specific socket */ 100typedef struct _SockInfo 101{ 102 curl_socket_t sockfd; 103 CURL *easy; 104 int action; 105 long timeout; 106 struct event *ev; 107 int evset; 108 GlobalInfo *global; 109} SockInfo; 110 111 112 113/* Update the event timer after curl_multi library calls */ 114static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g) 115{ 116 struct timeval timeout; 117 (void)multi; /* unused */ 118 119 timeout.tv_sec = timeout_ms/1000; 120 timeout.tv_usec = (timeout_ms%1000)*1000; 121 fprintf(MSG_OUT, "multi_timer_cb: Setting timeout to %ld ms\n", timeout_ms); 122 evtimer_add(g->timer_event, &timeout); 123 return 0; 124} 125 126/* Die if we get a bad CURLMcode somewhere */ 127static void mcode_or_die(const char *where, CURLMcode code) 128{ 129 if(CURLM_OK != code) { 130 const char *s; 131 switch (code) { 132 case CURLM_BAD_HANDLE: s="CURLM_BAD_HANDLE"; break; 133 case CURLM_BAD_EASY_HANDLE: s="CURLM_BAD_EASY_HANDLE"; break; 134 case CURLM_OUT_OF_MEMORY: s="CURLM_OUT_OF_MEMORY"; break; 135 case CURLM_INTERNAL_ERROR: s="CURLM_INTERNAL_ERROR"; break; 136 case CURLM_UNKNOWN_OPTION: s="CURLM_UNKNOWN_OPTION"; break; 137 case CURLM_LAST: s="CURLM_LAST"; break; 138 default: s="CURLM_unknown"; 139 break; 140 case CURLM_BAD_SOCKET: s="CURLM_BAD_SOCKET"; 141 fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s); 142 /* ignore this error */ 143 return; 144 } 145 fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s); 146 exit(code); 147 } 148} 149 150 151 152/* Check for completed transfers, and remove their easy handles */ 153static void check_multi_info(GlobalInfo *g) 154{ 155 char *eff_url; 156 CURLMsg *msg; 157 int msgs_left; 158 ConnInfo *conn; 159 CURL *easy; 160 CURLcode res; 161 162 fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running); 163 while((msg = curl_multi_info_read(g->multi, &msgs_left))) { 164 if(msg->msg == CURLMSG_DONE) { 165 easy = msg->easy_handle; 166 res = msg->data.result; 167 curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn); 168 curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url); 169 fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error); 170 curl_multi_remove_handle(g->multi, easy); 171 free(conn->url); 172 curl_easy_cleanup(easy); 173 free(conn); 174 } 175 } 176} 177 178 179 180/* Called by libevent when we get action on a multi socket */ 181static void event_cb(int fd, short kind, void *userp) 182{ 183 GlobalInfo *g = (GlobalInfo*) userp; 184 CURLMcode rc; 185 186 int action = 187 (kind & EV_READ ? CURL_CSELECT_IN : 0) | 188 (kind & EV_WRITE ? CURL_CSELECT_OUT : 0); 189 190 rc = curl_multi_socket_action(g->multi, fd, action, &g->still_running); 191 mcode_or_die("event_cb: curl_multi_socket_action", rc); 192 193 check_multi_info(g); 194 if(g->still_running <= 0) { 195 fprintf(MSG_OUT, "last transfer done, kill timeout\n"); 196 if(evtimer_pending(g->timer_event, NULL)) { 197 evtimer_del(g->timer_event); 198 } 199 } 200} 201 202 203 204/* Called by libevent when our timeout expires */ 205static void timer_cb(int fd, short kind, void *userp) 206{ 207 GlobalInfo *g = (GlobalInfo *)userp; 208 CURLMcode rc; 209 (void)fd; 210 (void)kind; 211 212 rc = curl_multi_socket_action(g->multi, 213 CURL_SOCKET_TIMEOUT, 0, &g->still_running); 214 mcode_or_die("timer_cb: curl_multi_socket_action", rc); 215 check_multi_info(g); 216} 217 218 219 220/* Clean up the SockInfo structure */ 221static void remsock(SockInfo *f) 222{ 223 if(f) { 224 if(f->evset) 225 event_free(f->ev); 226 free(f); 227 } 228} 229 230 231 232/* Assign information to a SockInfo structure */ 233static void setsock(SockInfo*f, curl_socket_t s, CURL*e, int act, GlobalInfo*g) 234{ 235 int kind = 236 (act&CURL_POLL_IN?EV_READ:0)|(act&CURL_POLL_OUT?EV_WRITE:0)|EV_PERSIST; 237 238 f->sockfd = s; 239 f->action = act; 240 f->easy = e; 241 if(f->evset) 242 event_free(f->ev); 243 f->ev = event_new(g->evbase, f->sockfd, kind, event_cb, g); 244 f->evset = 1; 245 event_add(f->ev, NULL); 246} 247 248 249 250/* Initialize a new SockInfo structure */ 251static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g) 252{ 253 SockInfo *fdp = calloc(sizeof(SockInfo), 1); 254 255 fdp->global = g; 256 setsock(fdp, s, easy, action, g); 257 curl_multi_assign(g->multi, s, fdp); 258} 259 260/* CURLMOPT_SOCKETFUNCTION */ 261static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp) 262{ 263 GlobalInfo *g = (GlobalInfo*) cbp; 264 SockInfo *fdp = (SockInfo*) sockp; 265 const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE" }; 266 267 fprintf(MSG_OUT, 268 "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]); 269 if(what == CURL_POLL_REMOVE) { 270 fprintf(MSG_OUT, "\n"); 271 remsock(fdp); 272 } 273 else { 274 if(!fdp) { 275 fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]); 276 addsock(s, e, what, g); 277 } 278 else { 279 fprintf(MSG_OUT, 280 "Changing action from %s to %s\n", 281 whatstr[fdp->action], whatstr[what]); 282 setsock(fdp, s, e, what, g); 283 } 284 } 285 return 0; 286} 287 288 289 290/* CURLOPT_WRITEFUNCTION */ 291static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data) 292{ 293 size_t realsize = size * nmemb; 294 ConnInfo *conn = (ConnInfo*) data; 295 (void)ptr; 296 (void)conn; 297 return realsize; 298} 299 300 301/* CURLOPT_PROGRESSFUNCTION */ 302static int prog_cb (void *p, double dltotal, double dlnow, double ult, 303 double uln) 304{ 305 ConnInfo *conn = (ConnInfo *)p; 306 (void)ult; 307 (void)uln; 308 309 fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal); 310 return 0; 311} 312 313 314/* Create a new easy handle, and add it to the global curl_multi */ 315static void new_conn(char *url, GlobalInfo *g) 316{ 317 ConnInfo *conn; 318 CURLMcode rc; 319 320 conn = calloc(1, sizeof(ConnInfo)); 321 memset(conn, 0, sizeof(ConnInfo)); 322 conn->error[0]='\0'; 323 324 conn->easy = curl_easy_init(); 325 if(!conn->easy) { 326 fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n"); 327 exit(2); 328 } 329 conn->global = g; 330 conn->url = strdup(url); 331 curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url); 332 curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb); 333 curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn); 334 curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L); 335 curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error); 336 curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn); 337 curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L); 338 curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb); 339 curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn); 340 fprintf(MSG_OUT, 341 "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url); 342 rc = curl_multi_add_handle(g->multi, conn->easy); 343 mcode_or_die("new_conn: curl_multi_add_handle", rc); 344 345 /* note that the add_handle() will set a time-out to trigger very soon so 346 that the necessary socket_action() call will be called by this app */ 347} 348 349/* This gets called whenever data is received from the fifo */ 350static void fifo_cb(int fd, short event, void *arg) 351{ 352 char s[1024]; 353 long int rv=0; 354 int n=0; 355 GlobalInfo *g = (GlobalInfo *)arg; 356 (void)fd; /* unused */ 357 (void)event; /* unused */ 358 359 do { 360 s[0]='\0'; 361 rv=fscanf(g->input, "%1023s%n", s, &n); 362 s[n]='\0'; 363 if(n && s[0]) { 364 new_conn(s, arg); /* if we read a URL, go get it! */ 365 } 366 else 367 break; 368 } while(rv != EOF); 369} 370 371/* Create a named pipe and tell libevent to monitor it */ 372static const char *fifo = "hiper.fifo"; 373static int init_fifo (GlobalInfo *g) 374{ 375 struct stat st; 376 curl_socket_t sockfd; 377 378 fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo); 379 if(lstat (fifo, &st) == 0) { 380 if((st.st_mode & S_IFMT) == S_IFREG) { 381 errno = EEXIST; 382 perror("lstat"); 383 exit (1); 384 } 385 } 386 unlink(fifo); 387 if(mkfifo (fifo, 0600) == -1) { 388 perror("mkfifo"); 389 exit (1); 390 } 391 sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0); 392 if(sockfd == -1) { 393 perror("open"); 394 exit (1); 395 } 396 g->input = fdopen(sockfd, "r"); 397 398 fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo); 399 g->fifo_event = event_new(g->evbase, sockfd, EV_READ|EV_PERSIST, fifo_cb, g); 400 event_add(g->fifo_event, NULL); 401 return (0); 402} 403 404static void clean_fifo(GlobalInfo *g) 405{ 406 event_free(g->fifo_event); 407 fclose(g->input); 408 unlink(fifo); 409} 410 411int main(int argc, char **argv) 412{ 413 GlobalInfo g; 414 (void)argc; 415 (void)argv; 416 417 memset(&g, 0, sizeof(GlobalInfo)); 418 g.evbase = event_base_new(); 419 init_fifo(&g); 420 g.multi = curl_multi_init(); 421 g.timer_event = evtimer_new(g.evbase, timer_cb, &g); 422 423 /* setup the generic multi interface options we want */ 424 curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb); 425 curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g); 426 curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb); 427 curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g); 428 429 /* we don't call any curl_multi_socket*() function yet as we have no handles 430 added! */ 431 432 event_base_dispatch(g.evbase); 433 434 /* this, of course, won't get called since only way to stop this program is 435 via ctrl-C, but it is here to show how cleanup /would/ be done. */ 436 clean_fifo(&g); 437 event_free(g.timer_event); 438 event_base_free(g.evbase); 439 curl_multi_cleanup(g.multi); 440 return 0; 441} 442