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22 
23 /* <DESC>
24  * SMTP example using the multi interface
25  * </DESC>
26  */
27 
28 #include <string.h>
29 #include <curl/curl.h>
30 
31 /* This is an example showing how to send mail using libcurl's SMTP
32  * capabilities. It builds on the smtp-mail.c example to demonstrate how to use
33  * libcurl's multi interface.
34  *
35  * Note that this example requires libcurl 7.20.0 or above.
36  */
37 
38 #define FROM     "<sender@example.com>"
39 #define TO       "<recipient@example.com>"
40 #define CC       "<info@example.com>"
41 
42 #define MULTI_PERFORM_HANG_TIMEOUT 60 * 1000
43 
44 static const char *payload_text[] = {
45   "Date: Mon, 29 Nov 2010 21:54:29 +1100\r\n",
46   "To: " TO "\r\n",
47   "From: " FROM " (Example User)\r\n",
48   "Cc: " CC " (Another example User)\r\n",
49   "Message-ID: <dcd7cb36-11db-487a-9f3a-e652a9458efd@"
50   "rfcpedant.example.org>\r\n",
51   "Subject: SMTP multi example message\r\n",
52   "\r\n", /* empty line to divide headers from body, see RFC5322 */
53   "The body of the message starts here.\r\n",
54   "\r\n",
55   "It could be a lot of lines, could be MIME encoded, whatever.\r\n",
56   "Check RFC5322.\r\n",
57   NULL
58 };
59 
60 struct upload_status {
61   int lines_read;
62 };
63 
payload_source(void * ptr,size_t size,size_t nmemb,void * userp)64 static size_t payload_source(void *ptr, size_t size, size_t nmemb, void *userp)
65 {
66   struct upload_status *upload_ctx = (struct upload_status *)userp;
67   const char *data;
68 
69   if((size == 0) || (nmemb == 0) || ((size*nmemb) < 1)) {
70     return 0;
71   }
72 
73   data = payload_text[upload_ctx->lines_read];
74 
75   if(data) {
76     size_t len = strlen(data);
77     memcpy(ptr, data, len);
78     upload_ctx->lines_read++;
79 
80     return len;
81   }
82 
83   return 0;
84 }
85 
tvnow(void)86 static struct timeval tvnow(void)
87 {
88   struct timeval now;
89 
90   /* time() returns the value of time in seconds since the epoch */
91   now.tv_sec = (long)time(NULL);
92   now.tv_usec = 0;
93 
94   return now;
95 }
96 
tvdiff(struct timeval newer,struct timeval older)97 static long tvdiff(struct timeval newer, struct timeval older)
98 {
99   return (newer.tv_sec - older.tv_sec) * 1000 +
100     (newer.tv_usec - older.tv_usec) / 1000;
101 }
102 
main(void)103 int main(void)
104 {
105   CURL *curl;
106   CURLM *mcurl;
107   int still_running = 1;
108   struct timeval mp_start;
109   struct curl_slist *recipients = NULL;
110   struct upload_status upload_ctx;
111 
112   upload_ctx.lines_read = 0;
113 
114   curl_global_init(CURL_GLOBAL_DEFAULT);
115 
116   curl = curl_easy_init();
117   if(!curl)
118     return 1;
119 
120   mcurl = curl_multi_init();
121   if(!mcurl)
122     return 2;
123 
124   /* This is the URL for your mailserver */
125   curl_easy_setopt(curl, CURLOPT_URL, "smtp://mail.example.com");
126 
127   /* Note that this option isn't strictly required, omitting it will result in
128    * libcurl sending the MAIL FROM command with empty sender data. All
129    * autoresponses should have an empty reverse-path, and should be directed
130    * to the address in the reverse-path which triggered them. Otherwise, they
131    * could cause an endless loop. See RFC 5321 Section 4.5.5 for more details.
132    */
133   curl_easy_setopt(curl, CURLOPT_MAIL_FROM, FROM);
134 
135   /* Add two recipients, in this particular case they correspond to the
136    * To: and Cc: addressees in the header, but they could be any kind of
137    * recipient. */
138   recipients = curl_slist_append(recipients, TO);
139   recipients = curl_slist_append(recipients, CC);
140   curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipients);
141 
142   /* We're using a callback function to specify the payload (the headers and
143    * body of the message). You could just use the CURLOPT_READDATA option to
144    * specify a FILE pointer to read from. */
145   curl_easy_setopt(curl, CURLOPT_READFUNCTION, payload_source);
146   curl_easy_setopt(curl, CURLOPT_READDATA, &upload_ctx);
147   curl_easy_setopt(curl, CURLOPT_UPLOAD, 1L);
148 
149   /* Tell the multi stack about our easy handle */
150   curl_multi_add_handle(mcurl, curl);
151 
152   /* Record the start time which we can use later */
153   mp_start = tvnow();
154 
155   /* We start some action by calling perform right away */
156   curl_multi_perform(mcurl, &still_running);
157 
158   while(still_running) {
159     struct timeval timeout;
160     fd_set fdread;
161     fd_set fdwrite;
162     fd_set fdexcep;
163     int maxfd = -1;
164     int rc;
165     CURLMcode mc; /* curl_multi_fdset() return code */
166 
167     long curl_timeo = -1;
168 
169     /* Initialise the file descriptors */
170     FD_ZERO(&fdread);
171     FD_ZERO(&fdwrite);
172     FD_ZERO(&fdexcep);
173 
174     /* Set a suitable timeout to play around with */
175     timeout.tv_sec = 1;
176     timeout.tv_usec = 0;
177 
178     curl_multi_timeout(mcurl, &curl_timeo);
179     if(curl_timeo >= 0) {
180       timeout.tv_sec = curl_timeo / 1000;
181       if(timeout.tv_sec > 1)
182         timeout.tv_sec = 1;
183       else
184         timeout.tv_usec = (curl_timeo % 1000) * 1000;
185     }
186 
187     /* get file descriptors from the transfers */
188     mc = curl_multi_fdset(mcurl, &fdread, &fdwrite, &fdexcep, &maxfd);
189 
190     if(mc != CURLM_OK) {
191       fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
192       break;
193     }
194 
195     /* On success the value of maxfd is guaranteed to be >= -1. We call
196        select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
197        no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
198        to sleep 100ms, which is the minimum suggested value in the
199        curl_multi_fdset() doc. */
200 
201     if(maxfd == -1) {
202 #ifdef _WIN32
203       Sleep(100);
204       rc = 0;
205 #else
206       /* Portable sleep for platforms other than Windows. */
207       struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
208       rc = select(0, NULL, NULL, NULL, &wait);
209 #endif
210     }
211     else {
212       /* Note that on some platforms 'timeout' may be modified by select().
213          If you need access to the original value save a copy beforehand. */
214       rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
215     }
216 
217     if(tvdiff(tvnow(), mp_start) > MULTI_PERFORM_HANG_TIMEOUT) {
218       fprintf(stderr,
219               "ABORTING: Since it seems that we would have run forever.\n");
220       break;
221     }
222 
223     switch(rc) {
224     case -1:  /* select error */
225       break;
226     case 0:   /* timeout */
227     default:  /* action */
228       curl_multi_perform(mcurl, &still_running);
229       break;
230     }
231   }
232 
233   /* Free the list of recipients */
234   curl_slist_free_all(recipients);
235 
236   /* Always cleanup */
237   curl_multi_remove_handle(mcurl, curl);
238   curl_multi_cleanup(mcurl);
239   curl_easy_cleanup(curl);
240   curl_global_cleanup();
241 
242   return 0;
243 }
244