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