1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24/* <DESC>
25 * multi socket interface together with libev
26 * </DESC>
27 */
28/* Example application source code using the multi socket interface to
29 * download many files at once.
30 *
31 * This example features the same basic functionality as hiperfifo.c does,
32 * but this uses libev instead of libevent.
33 *
34 * Written by Jeff Pohlmeyer, converted to use libev by Markus Koetter
35
36Requires libev and a (POSIX?) system that has mkfifo().
37
38This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
39sample programs.
40
41When running, the program creates the named pipe "hiper.fifo"
42
43Whenever there is input into the fifo, the program reads the input as a list
44of URL's and creates some new easy handles to fetch each URL via the
45curl_multi "hiper" API.
46
47
48Thus, you can try a single URL:
49  % echo http://www.yahoo.com > hiper.fifo
50
51Or a whole bunch of them:
52  % cat my-url-list > hiper.fifo
53
54The fifo buffer is handled almost instantly, so you can even add more URL's
55while the previous requests are still being downloaded.
56
57Note:
58  For the sake of simplicity, URL length is limited to 1023 char's !
59
60This is purely a demo app, all retrieved data is simply discarded by the write
61callback.
62
63*/
64
65#include <stdio.h>
66#include <string.h>
67#include <stdlib.h>
68#include <sys/time.h>
69#include <time.h>
70#include <unistd.h>
71#include <sys/poll.h>
72#include <curl/curl.h>
73#include <ev.h>
74#include <fcntl.h>
75#include <sys/stat.h>
76#include <errno.h>
77
78#define DPRINT(x...) printf(x)
79
80#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */
81
82
83/* Global information, common to all connections */
84typedef struct _GlobalInfo
85{
86  struct ev_loop *loop;
87  struct ev_io fifo_event;
88  struct ev_timer timer_event;
89  CURLM *multi;
90  int still_running;
91  FILE *input;
92} GlobalInfo;
93
94
95/* Information associated with a specific easy handle */
96typedef struct _ConnInfo
97{
98  CURL *easy;
99  char *url;
100  GlobalInfo *global;
101  char error[CURL_ERROR_SIZE];
102} ConnInfo;
103
104
105/* Information associated with a specific socket */
106typedef struct _SockInfo
107{
108  curl_socket_t sockfd;
109  CURL *easy;
110  int action;
111  long timeout;
112  struct ev_io ev;
113  int evset;
114  GlobalInfo *global;
115} SockInfo;
116
117static void timer_cb(EV_P_ struct ev_timer *w, int revents);
118
119/* Update the event timer after curl_multi library calls */
120static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
121{
122  DPRINT("%s %li\n", __PRETTY_FUNCTION__,  timeout_ms);
123  ev_timer_stop(g->loop, &g->timer_event);
124  if(timeout_ms >= 0) {
125    /* -1 means delete, other values are timeout times in milliseconds */
126    double  t = timeout_ms / 1000;
127    ev_timer_init(&g->timer_event, timer_cb, t, 0.);
128    ev_timer_start(g->loop, &g->timer_event);
129  }
130  return 0;
131}
132
133/* Die if we get a bad CURLMcode somewhere */
134static void mcode_or_die(const char *where, CURLMcode code)
135{
136  if(CURLM_OK != code) {
137    const char *s;
138    switch(code) {
139    case CURLM_BAD_HANDLE:
140      s = "CURLM_BAD_HANDLE";
141      break;
142    case CURLM_BAD_EASY_HANDLE:
143      s = "CURLM_BAD_EASY_HANDLE";
144      break;
145    case CURLM_OUT_OF_MEMORY:
146      s = "CURLM_OUT_OF_MEMORY";
147      break;
148    case CURLM_INTERNAL_ERROR:
149      s = "CURLM_INTERNAL_ERROR";
150      break;
151    case CURLM_UNKNOWN_OPTION:
152      s = "CURLM_UNKNOWN_OPTION";
153      break;
154    case CURLM_LAST:
155      s = "CURLM_LAST";
156      break;
157    default:
158      s = "CURLM_unknown";
159      break;
160    case CURLM_BAD_SOCKET:
161      s = "CURLM_BAD_SOCKET";
162      fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
163      /* ignore this error */
164      return;
165    }
166    fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
167    exit(code);
168  }
169}
170
171
172
173/* Check for completed transfers, and remove their easy handles */
174static void check_multi_info(GlobalInfo *g)
175{
176  char *eff_url;
177  CURLMsg *msg;
178  int msgs_left;
179  ConnInfo *conn;
180  CURL *easy;
181  CURLcode res;
182
183  fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
184  while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
185    if(msg->msg == CURLMSG_DONE) {
186      easy = msg->easy_handle;
187      res = msg->data.result;
188      curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
189      curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
190      fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
191      curl_multi_remove_handle(g->multi, easy);
192      free(conn->url);
193      curl_easy_cleanup(easy);
194      free(conn);
195    }
196  }
197}
198
199
200
201/* Called by libevent when we get action on a multi socket */
202static void event_cb(EV_P_ struct ev_io *w, int revents)
203{
204  DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);
205  GlobalInfo *g = (GlobalInfo*) w->data;
206  CURLMcode rc;
207
208  int action = ((revents & EV_READ) ? CURL_POLL_IN : 0) |
209    ((revents & EV_WRITE) ? CURL_POLL_OUT : 0);
210  rc = curl_multi_socket_action(g->multi, w->fd, action, &g->still_running);
211  mcode_or_die("event_cb: curl_multi_socket_action", rc);
212  check_multi_info(g);
213  if(g->still_running <= 0) {
214    fprintf(MSG_OUT, "last transfer done, kill timeout\n");
215    ev_timer_stop(g->loop, &g->timer_event);
216  }
217}
218
219/* Called by libevent when our timeout expires */
220static void timer_cb(EV_P_ struct ev_timer *w, int revents)
221{
222  DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);
223
224  GlobalInfo *g = (GlobalInfo *)w->data;
225  CURLMcode rc;
226
227  rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0,
228                                &g->still_running);
229  mcode_or_die("timer_cb: curl_multi_socket_action", rc);
230  check_multi_info(g);
231}
232
233/* Clean up the SockInfo structure */
234static void remsock(SockInfo *f, GlobalInfo *g)
235{
236  printf("%s  \n", __PRETTY_FUNCTION__);
237  if(f) {
238    if(f->evset)
239      ev_io_stop(g->loop, &f->ev);
240    free(f);
241  }
242}
243
244
245
246/* Assign information to a SockInfo structure */
247static void setsock(SockInfo *f, curl_socket_t s, CURL *e, int act,
248                    GlobalInfo *g)
249{
250  printf("%s  \n", __PRETTY_FUNCTION__);
251
252  int kind = ((act & CURL_POLL_IN) ? EV_READ : 0) |
253             ((act & CURL_POLL_OUT) ? EV_WRITE : 0);
254
255  f->sockfd = s;
256  f->action = act;
257  f->easy = e;
258  if(f->evset)
259    ev_io_stop(g->loop, &f->ev);
260  ev_io_init(&f->ev, event_cb, f->sockfd, kind);
261  f->ev.data = g;
262  f->evset = 1;
263  ev_io_start(g->loop, &f->ev);
264}
265
266
267
268/* Initialize a new SockInfo structure */
269static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
270{
271  SockInfo *fdp = calloc(1, sizeof(SockInfo));
272
273  fdp->global = g;
274  setsock(fdp, s, easy, action, g);
275  curl_multi_assign(g->multi, s, fdp);
276}
277
278/* CURLMOPT_SOCKETFUNCTION */
279static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
280{
281  DPRINT("%s e %p s %i what %i cbp %p sockp %p\n",
282         __PRETTY_FUNCTION__, e, s, what, cbp, sockp);
283
284  GlobalInfo *g = (GlobalInfo*) cbp;
285  SockInfo *fdp = (SockInfo*) sockp;
286  const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE"};
287
288  fprintf(MSG_OUT,
289          "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
290  if(what == CURL_POLL_REMOVE) {
291    fprintf(MSG_OUT, "\n");
292    remsock(fdp, g);
293  }
294  else {
295    if(!fdp) {
296      fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
297      addsock(s, e, what, g);
298    }
299    else {
300      fprintf(MSG_OUT,
301              "Changing action from %s to %s\n",
302              whatstr[fdp->action], whatstr[what]);
303      setsock(fdp, s, e, what, g);
304    }
305  }
306  return 0;
307}
308
309
310/* CURLOPT_WRITEFUNCTION */
311static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
312{
313  size_t realsize = size * nmemb;
314  ConnInfo *conn = (ConnInfo*) data;
315  (void)ptr;
316  (void)conn;
317  return realsize;
318}
319
320
321/* CURLOPT_PROGRESSFUNCTION */
322static int prog_cb(void *p, double dltotal, double dlnow, double ult,
323                   double uln)
324{
325  ConnInfo *conn = (ConnInfo *)p;
326  (void)ult;
327  (void)uln;
328
329  fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
330  return 0;
331}
332
333
334/* Create a new easy handle, and add it to the global curl_multi */
335static void new_conn(char *url, GlobalInfo *g)
336{
337  ConnInfo *conn;
338  CURLMcode rc;
339
340  conn = calloc(1, sizeof(ConnInfo));
341  conn->error[0]='\0';
342
343  conn->easy = curl_easy_init();
344  if(!conn->easy) {
345    fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
346    exit(2);
347  }
348  conn->global = g;
349  conn->url = strdup(url);
350  curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
351  curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
352  curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
353  curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
354  curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
355  curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
356  curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
357  curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
358  curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
359  curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
360  curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);
361
362  fprintf(MSG_OUT,
363          "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
364  rc = curl_multi_add_handle(g->multi, conn->easy);
365  mcode_or_die("new_conn: curl_multi_add_handle", rc);
366
367  /* note that the add_handle() will set a time-out to trigger soon so that
368     the necessary socket_action() call will be called by this app */
369}
370
371/* This gets called whenever data is received from the fifo */
372static void fifo_cb(EV_P_ struct ev_io *w, int revents)
373{
374  char s[1024];
375  long int rv = 0;
376  int n = 0;
377  GlobalInfo *g = (GlobalInfo *)w->data;
378
379  do {
380    s[0]='\0';
381    rv = fscanf(g->input, "%1023s%n", s, &n);
382    s[n]='\0';
383    if(n && s[0]) {
384      new_conn(s, g);  /* if we read a URL, go get it! */
385    }
386    else
387      break;
388  } while(rv != EOF);
389}
390
391/* Create a named pipe and tell libevent to monitor it */
392static int init_fifo(GlobalInfo *g)
393{
394  struct stat st;
395  static const char *fifo = "hiper.fifo";
396  curl_socket_t sockfd;
397
398  fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
399  if(lstat (fifo, &st) == 0) {
400    if((st.st_mode & S_IFMT) == S_IFREG) {
401      errno = EEXIST;
402      perror("lstat");
403      exit(1);
404    }
405  }
406  unlink(fifo);
407  if(mkfifo (fifo, 0600) == -1) {
408    perror("mkfifo");
409    exit(1);
410  }
411  sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
412  if(sockfd == -1) {
413    perror("open");
414    exit(1);
415  }
416  g->input = fdopen(sockfd, "r");
417
418  fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
419  ev_io_init(&g->fifo_event, fifo_cb, sockfd, EV_READ);
420  ev_io_start(g->loop, &g->fifo_event);
421  return (0);
422}
423
424int main(int argc, char **argv)
425{
426  GlobalInfo g;
427  (void)argc;
428  (void)argv;
429
430  memset(&g, 0, sizeof(GlobalInfo));
431  g.loop = ev_default_loop(0);
432
433  init_fifo(&g);
434  g.multi = curl_multi_init();
435
436  ev_timer_init(&g.timer_event, timer_cb, 0., 0.);
437  g.timer_event.data = &g;
438  g.fifo_event.data = &g;
439  curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
440  curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
441  curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
442  curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);
443
444  /* we do not call any curl_multi_socket*() function yet as we have no handles
445     added! */
446
447  ev_loop(g.loop, 0);
448  curl_multi_cleanup(g.multi);
449  return 0;
450}
451