aboutsummaryrefslogtreecommitdiff
path: root/docs/examples/smtp-multi.c
blob: 79db7ab3030efafdd5365df526e414ef89800270 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2015, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

/* <DESC>
 * SMTP example using the multi interface
 * </DESC>
 */

#include <string.h>
#include <curl/curl.h>

/* This is an example showing how to send mail using libcurl's SMTP
 * capabilities. It builds on the smtp-mail.c example to demonstrate how to use
 * libcurl's multi interface.
 *
 * Note that this example requires libcurl 7.20.0 or above.
 */

#define FROM     "<sender@example.com>"
#define TO       "<recipient@example.com>"
#define CC       "<info@example.com>"

#define MULTI_PERFORM_HANG_TIMEOUT 60 * 1000

static const char *payload_text[] = {
  "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n",
  "To: " TO "\r\n",
  "From: " FROM "(Example User)\r\n",
  "Cc: " CC "(Another example User)\r\n",
  "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@rfcpedant.example.org>\r\n",
  "Subject: SMTP multi example message\r\n",
  "\r\n", /* empty line to divide headers from body, see RFC5322 */
  "The body of the message starts here.\r\n",
  "\r\n",
  "It could be a lot of lines, could be MIME encoded, whatever.\r\n",
  "Check RFC5322.\r\n",
  NULL
};

struct upload_status {
  int lines_read;
};

static size_t payload_source(void *ptr, size_t size, size_t nmemb, void *userp)
{
  struct upload_status *upload_ctx = (struct upload_status *)userp;
  const char *data;

  if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
    return 0;
  }

  data = payload_text[upload_ctx->lines_read];

  if(data) {
    size_t len = strlen(data);
    memcpy(ptr, data, len);
    upload_ctx->lines_read++;

    return len;
  }

  return 0;
}

static struct timeval tvnow(void)
{
  struct timeval now;

  /* time() returns the value of time in seconds since the epoch */
  now.tv_sec = (long)time(NULL);
  now.tv_usec = 0;

  return now;
}

static long tvdiff(struct timeval newer, struct timeval older)
{
  return (newer.tv_sec - older.tv_sec) * 1000 +
    (newer.tv_usec - older.tv_usec) / 1000;
}

int main(void)
{
  CURL *curl;
  CURLM *mcurl;
  int still_running = 1;
  struct timeval mp_start;
  struct curl_slist *recipients = NULL;
  struct upload_status upload_ctx;

  upload_ctx.lines_read = 0;

  curl_global_init(CURL_GLOBAL_DEFAULT);

  curl = curl_easy_init();
  if(!curl)
    return 1;

  mcurl = curl_multi_init();
  if(!mcurl)
    return 2;

  /* This is the URL for your mailserver */
  curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com");

  /* Note that this option isn't strictly required, omitting it will result in
   * libcurl sending the MAIL FROM command with empty sender data. All
   * autoresponses should have an empty reverse-path, and should be directed
   * to the address in the reverse-path which triggered them. Otherwise, they
   * could cause an endless loop. See RFC 5321 Section 4.5.5 for more details.
   */
  curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);

  /* Add two recipients, in this particular case they correspond to the
   * To: and Cc: addressees in the header, but they could be any kind of
   * recipient. */
  recipients = curl_slist_append(recipients, TO);
  recipients = curl_slist_append(recipients, CC);
  curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);

  /* We're using a callback function to specify the payload (the headers and
   * body of the message). You could just use the CURLOPT_READDATA option to
   * specify a FILE pointer to read from. */
  curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
  curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
  curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);

  /* Tell the multi stack about our easy handle */
  curl_multi_add_handle(mcurl, curl);

  /* Record the start time which we can use later */
  mp_start = tvnow();

  /* We start some action by calling perform right away */
  curl_multi_perform(mcurl, &still_running);

  while(still_running) {
    struct timeval timeout;
    fd_set fdread;
    fd_set fdwrite;
    fd_set fdexcep;
    int maxfd = -1;
    int rc;
    CURLMcode mc; /* curl_multi_fdset() return code */

    long curl_timeo = -1;

    /* Initialise the file descriptors */
    FD_ZERO(&fdread);
    FD_ZERO(&fdwrite);
    FD_ZERO(&fdexcep);

    /* Set a suitable timeout to play around with */
    timeout.tv_sec = 1;
    timeout.tv_usec = 0;

    curl_multi_timeout(mcurl, &curl_timeo);
    if(curl_timeo >= 0) {
      timeout.tv_sec = curl_timeo / 1000;
      if(timeout.tv_sec > 1)
        timeout.tv_sec = 1;
      else
        timeout.tv_usec = (curl_timeo % 1000) * 1000;
    }

    /* get file descriptors from the transfers */
    mc = curl_multi_fdset(mcurl, &fdread, &fdwrite, &fdexcep, &maxfd);

    if(mc != CURLM_OK)
    {
      fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
      break;
    }

    /* On success the value of maxfd is guaranteed to be >= -1. We call
       select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
       no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
       to sleep 100ms, which is the minimum suggested value in the
       curl_multi_fdset() doc. */

    if(maxfd == -1) {
#ifdef _WIN32
      Sleep(100);
      rc = 0;
#else
      /* Portable sleep for platforms other than Windows. */
      struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
      rc = select(0, NULL, NULL, NULL, &wait);
#endif
    }
    else {
      /* Note that on some platforms 'timeout' may be modified by select().
         If you need access to the original value save a copy beforehand. */
      rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
    }

    if(tvdiff(tvnow(), mp_start) > MULTI_PERFORM_HANG_TIMEOUT) {
      fprintf(stderr,
              "ABORTING: Since it seems that we would have run forever.\n");
      break;
    }

    switch(rc) {
    case -1:  /* select error */
      break;
    case 0:   /* timeout */
    default:  /* action */
      curl_multi_perform(mcurl, &still_running);
      break;
    }
  }

  /* Free the list of recipients */
  curl_slist_free_all(recipients);

  /* Always cleanup */
  curl_multi_remove_handle(mcurl, curl);
  curl_multi_cleanup(mcurl);
  curl_easy_cleanup(curl);
  curl_global_cleanup();

  return 0;
}