Bugzilla 1041: pull patch id=425, DCC fixes.
[exim.git] / src / src / dcc.c
CommitLineData
e93a964c 1/* $Cambridge: exim/src/src/dcc.c,v 1.5 2009/11/12 08:34:23 nm4 Exp $ */
6a8f9482
TK
2
3/*************************************************
4* Exim - an Internet mail transport agent *
5*************************************************/
6
1a9312b2 7/* Copyright (c) Wolfgang Breyha 2005-2009
6a8f9482
TK
8 * Vienna University Computer Center
9 * wbreyha@gmx.net
b9e94344 10 * See the file NOTICE for conditions of use and distribution.
6a8f9482
TK
11 */
12
13/* This patch is based on code from Tom Kistners exiscan (ACL integration) and
14 * the DCC local_scan patch from Christopher Bodenstein */
15
16/* Code for calling dccifd. Called from acl.c. */
17
18#include "exim.h"
19#ifdef EXPERIMENTAL_DCC
20#include "dcc.h"
21#include "unistd.h"
22
23uschar dcc_header_str[256];
24uschar dcc_result_str[256];
25int dcc_ok = 0;
26int dcc_rc = 0;
27
28/* This function takes a file descriptor and a buffer as input and
29 * returns either 0 for success or errno in case of error. */
30
31int flushbuffer (int socket, uschar *buffer)
32 {
33 int retval, rsp;
34 rsp = write(socket, buffer, Ustrlen(buffer));
35 DEBUG(D_acl)
36 debug_printf("Result of the write() = %d\n", rsp);
37 if(rsp < 0)
38 {
39 DEBUG(D_acl)
40 debug_printf("Error writing buffer to socket: %s\n", strerror(errno));
41 retval = errno;
42 } else {
43 DEBUG(D_acl)
44 debug_printf("Wrote buffer to socket:\n%s\n", buffer);
45 retval = 0;
46 }
47 return retval;
48}
49
50int dcc_process(uschar **listptr) {
51 int sep = 0;
52 uschar *list = *listptr;
6a8f9482 53 FILE *data_file;
6a8f9482 54 uschar *dcc_daemon_ip = US"";
6a8f9482
TK
55 uschar *dcc_default_ip_option = US"127.0.0.1";
56 uschar *dcc_ip_option = US"";
57 uschar *dcc_helo_option = US"localhost";
58 uschar *dcc_reject_message = US"Rejected by DCC";
1a9312b2 59 uschar *xtra_hdrs = NULL;
6a8f9482
TK
60
61 /* from local_scan */
e93a964c 62 int i, j, k, c, retval, sockfd, resp, line;
7156b1ef 63 unsigned int portnr;
6a8f9482
TK
64 struct sockaddr_un serv_addr;
65 struct sockaddr_in serv_addr_in;
66 struct hostent *ipaddress;
67 uschar sockpath[128];
68 uschar sockip[40], client_ip[40];
69 uschar opts[128];
70 uschar rcpt[128], from[128];
71 uschar sendbuf[4096];
72 uschar recvbuf[4096];
73 uschar xhdr[256];
74 uschar dcc_return_text[1024];
75 uschar mbox_path[1024];
76 uschar message_subdir[2];
77 struct header_line *dcchdr;
6a8f9482
TK
78 uschar *dcc_acl_options;
79 uschar dcc_acl_options_buffer[10];
1a9312b2 80 uschar dcc_xtra_hdrs[1024];
6a8f9482 81
6a8f9482
TK
82 /* grep 1st option */
83 if ((dcc_acl_options = string_nextinlist(&list, &sep,
84 dcc_acl_options_buffer,
85 sizeof(dcc_acl_options_buffer))) != NULL)
86 {
87 /* parse 1st option */
88 if ( (strcmpic(dcc_acl_options,US"false") == 0) ||
89 (Ustrcmp(dcc_acl_options,"0") == 0) ) {
90 /* explicitly no matching */
91 return FAIL;
92 };
93
94 /* special cases (match anything except empty) */
95 if ( (strcmpic(dcc_acl_options,US"true") == 0) ||
96 (Ustrcmp(dcc_acl_options,"*") == 0) ||
97 (Ustrcmp(dcc_acl_options,"1") == 0) ) {
98 dcc_acl_options = dcc_acl_options;
99 };
100 }
101 else {
102 /* empty means "don't match anything" */
103 return FAIL;
104 };
105
106 sep = 0;
107
108 /* if we scanned this message last time, just return */
109 if ( dcc_ok )
110 return dcc_rc;
111
112 /* open the spooled body */
113 message_subdir[1] = '\0';
114 for (i = 0; i < 2; i++) {
115 message_subdir[0] = (split_spool_directory == (i == 0))? message_id[5] : 0;
116 sprintf(CS mbox_path, "%s/input/%s/%s-D", spool_directory, message_subdir, message_id);
117 data_file = Ufopen(mbox_path,"rb");
118 if (data_file != NULL)
119 break;
120 };
121
122 if (data_file == NULL) {
123 /* error while spooling */
124 log_write(0, LOG_MAIN|LOG_PANIC,
125 "dcc acl condition: error while opening spool file");
126 return DEFER;
127 };
128
129 /* Initialize the variables */
130
131 bzero(sockip,sizeof(sockip));
132 if (dccifd_address) {
133 if (dccifd_address[0] == '/')
134 Ustrncpy(sockpath, dccifd_address, sizeof(sockpath));
135 else
7156b1ef 136 if( sscanf(CS dccifd_address, "%s %u", sockip, &portnr) != 2) {
6a8f9482
TK
137 log_write(0, LOG_MAIN,
138 "dcc acl condition: warning - invalid dccifd address: '%s'", dccifd_address);
139 (void)fclose(data_file);
140 return DEFER;
141 }
142 }
143
144 /* opts is what we send as dccifd options - see man dccifd */
145 /* We don't support any other option than 'header' so just copy that */
146 bzero(opts,sizeof(opts));
147 Ustrncpy(opts, "header", sizeof(opts)-1);
148 Ustrncpy(client_ip, dcc_ip_option, sizeof(client_ip)-1);
149 /* If the dcc_client_ip is not provided use the
150 * sender_host_address or 127.0.0.1 if it is NULL */
151 DEBUG(D_acl)
152 debug_printf("my_ip_option = %s - client_ip = %s - sender_host_address = %s\n", dcc_ip_option, client_ip, sender_host_address);
153 if(!(Ustrcmp(client_ip, ""))){
154 /* Do we have a sender_host_address or is it NULL? */
155 if(sender_host_address){
1a9312b2 156 Ustrncpy(client_ip, sender_host_address, sizeof(client_ip)-1);
6a8f9482
TK
157 } else {
158 /* sender_host_address is NULL which means it comes from localhost */
159 Ustrncpy(client_ip, dcc_default_ip_option, sizeof(client_ip)-1);
160 }
161 }
162 DEBUG(D_acl)
163 debug_printf("Client IP: %s\n", client_ip);
164 Ustrncpy(sockip, dcc_daemon_ip, sizeof(sockip)-1);
165 /* strncat(opts, my_request, strlen(my_request)); */
166 Ustrcat(opts, "\n");
167 Ustrncat(opts, client_ip, sizeof(opts)-Ustrlen(opts)-1);
168 Ustrncat(opts, "\nHELO ", sizeof(opts)-Ustrlen(opts)-1);
169 Ustrncat(opts, dcc_helo_option, sizeof(opts)-Ustrlen(opts)-2);
170 Ustrcat(opts, "\n");
171
172 /* initialize the other variables */
173 dcchdr = header_list;
6a8f9482
TK
174 /* we set the default return value to DEFER */
175 retval = DEFER;
176
177 bzero(sendbuf,sizeof(sendbuf));
178 bzero(xhdr,sizeof(xhdr));
179 bzero(rcpt,sizeof(rcpt));
180 bzero(from,sizeof(from));
181
1a9312b2
TK
182 /* send a null return path as "<>". */
183 if (Ustrlen(sender_address) > 0)
184 Ustrncpy(from, sender_address, sizeof(from));
185 else
186 Ustrncpy(from, "<>", sizeof(from));
6a8f9482
TK
187 Ustrncat(from, "\n", sizeof(from)-Ustrlen(from)-1);
188
189 /**************************************
190 * Now creating the socket connection *
191 **************************************/
192
193 /* If there is a dcc_daemon_ip, we use a tcp socket, otherwise a UNIX socket */
194 if(Ustrcmp(sockip, "")){
195 ipaddress = gethostbyname((char *)sockip);
196 bzero((char *) &serv_addr_in, sizeof(serv_addr_in));
197 serv_addr_in.sin_family = AF_INET;
198 bcopy((char *)ipaddress->h_addr, (char *)&serv_addr_in.sin_addr.s_addr, ipaddress->h_length);
199 serv_addr_in.sin_port = htons(portnr);
200 if ((sockfd = socket(AF_INET, SOCK_STREAM,0)) < 0){
201 DEBUG(D_acl)
202 debug_printf("Creating socket failed: %s\n", strerror(errno));
203 log_write(0,LOG_REJECT,"Creating socket failed: %s\n", strerror(errno));
204 /* if we cannot create the socket, defer the mail */
205 (void)fclose(data_file);
206 return retval;
207 }
208 /* Now connecting the socket (INET) */
209 if (connect(sockfd, (struct sockaddr *)&serv_addr_in, sizeof(serv_addr_in)) < 0){
210 DEBUG(D_acl)
211 debug_printf("Connecting socket failed: %s\n", strerror(errno));
212 log_write(0,LOG_REJECT,"Connecting socket failed: %s\n", strerror(errno));
213 /* if we cannot contact the socket, defer the mail */
214 (void)fclose(data_file);
215 return retval;
216 }
217 } else {
218 /* connecting to the dccifd UNIX socket */
219 bzero((char *)&serv_addr,sizeof(serv_addr));
220 serv_addr.sun_family = AF_UNIX;
221 Ustrcpy(serv_addr.sun_path, sockpath);
6a8f9482
TK
222 if ((sockfd = socket(AF_UNIX, SOCK_STREAM,0)) < 0){
223 DEBUG(D_acl)
224 debug_printf("Creating socket failed: %s\n", strerror(errno));
225 log_write(0,LOG_REJECT,"Creating socket failed: %s\n", strerror(errno));
226 /* if we cannot create the socket, defer the mail */
227 (void)fclose(data_file);
228 return retval;
229 }
230 /* Now connecting the socket (UNIX) */
e93a964c 231 if (connect(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0){
6a8f9482
TK
232 DEBUG(D_acl)
233 debug_printf("Connecting socket failed: %s\n", strerror(errno));
234 log_write(0,LOG_REJECT,"Connecting socket failed: %s\n", strerror(errno));
235 /* if we cannot contact the socket, defer the mail */
236 (void)fclose(data_file);
237 return retval;
238 }
239 }
240 /* the socket is open, now send the options to dccifd*/
241 DEBUG(D_acl)
242 debug_printf("\n---------------------------\nSocket opened; now sending input\n-----------------\n");
243 /* First, fill in the input buffer */
244 Ustrncpy(sendbuf, opts, sizeof(sendbuf));
245 Ustrncat(sendbuf, from, sizeof(sendbuf)-Ustrlen(sendbuf)-1);
246
247 DEBUG(D_acl)
248 {
249 debug_printf("opts = %s\nsender = %s\nrcpt count = %d\n", opts, from, recipients_count);
250 debug_printf("Sending options:\n****************************\n");
251 }
252
253 /* let's send each of the recipients to dccifd */
254 for (i = 0; i < recipients_count; i++){
255 DEBUG(D_acl)
256 debug_printf("recipient = %s\n",recipients_list[i].address);
257 if(Ustrlen(sendbuf) + Ustrlen(recipients_list[i].address) > sizeof(sendbuf))
258 {
259 DEBUG(D_acl)
260 debug_printf("Writing buffer: %s\n", sendbuf);
261 flushbuffer(sockfd, sendbuf);
262 bzero(sendbuf, sizeof(sendbuf));
263 }
264 Ustrncat(sendbuf, recipients_list[i].address, sizeof(sendbuf)-Ustrlen(sendbuf)-1);
265 Ustrncat(sendbuf, "\r\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
266 }
267 /* send a blank line between options and message */
268 Ustrncat(sendbuf, "\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
269 /* Now we send the input buffer */
270 DEBUG(D_acl)
271 debug_printf("%s\n****************************\n", sendbuf);
272 flushbuffer(sockfd, sendbuf);
273
274 /* now send the message */
275 /* Clear the input buffer */
276 bzero(sendbuf, sizeof(sendbuf));
277 /* First send the headers */
278 /* Now send the headers */
279 DEBUG(D_acl)
280 debug_printf("Sending headers:\n****************************\n");
281 Ustrncpy(sendbuf, dcchdr->text, sizeof(sendbuf)-2);
282 while((dcchdr=dcchdr->next)) {
283 if(dcchdr->slen > sizeof(sendbuf)-2) {
284 /* The size of the header is bigger than the size of
285 * the input buffer, so split it up in smaller parts. */
286 flushbuffer(sockfd, sendbuf);
287 bzero(sendbuf, sizeof(sendbuf));
288 j = 0;
289 while(j < dcchdr->slen)
290 {
291 for(i = 0; i < sizeof(sendbuf)-2; i++) {
292 sendbuf[i] = dcchdr->text[j];
293 j++;
294 }
295 flushbuffer(sockfd, sendbuf);
296 bzero(sendbuf, sizeof(sendbuf));
297 }
298 } else if(Ustrlen(sendbuf) + dcchdr->slen > sizeof(sendbuf)-2) {
299 flushbuffer(sockfd, sendbuf);
300 bzero(sendbuf, sizeof(sendbuf));
301 Ustrncpy(sendbuf, dcchdr->text, sizeof(sendbuf)-2);
302 } else {
303 Ustrncat(sendbuf, dcchdr->text, sizeof(sendbuf)-Ustrlen(sendbuf)-2);
304 }
305 }
306
307 /* a blank line separates header from body */
308 Ustrncat(sendbuf, "\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
309 flushbuffer(sockfd, sendbuf);
310 DEBUG(D_acl)
7156b1ef 311 debug_printf("\n****************************\n%s", sendbuf);
6a8f9482
TK
312
313 /* Clear the input buffer */
314 bzero(sendbuf, sizeof(sendbuf));
315
316 /* now send the body */
317 DEBUG(D_acl)
318 debug_printf("Writing body:\n****************************\n");
319 (void)fseek(data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
320 while((fread(sendbuf, 1, sizeof(sendbuf)-1, data_file)) > 0) {
321 flushbuffer(sockfd, sendbuf);
322 bzero(sendbuf, sizeof(sendbuf));
323 }
324 DEBUG(D_acl)
325 debug_printf("\n****************************\n");
326
327 /* shutdown() the socket */
328 if(shutdown(sockfd, 1) < 0){
329 DEBUG(D_acl)
330 debug_printf("Couldn't shutdown socket: %s\n", strerror(errno));
331 log_write(0,LOG_MAIN,"Couldn't shutdown socket: %s\n", strerror(errno));
332 /* If there is a problem with the shutdown()
333 * defer the mail. */
334 (void)fclose(data_file);
335 return retval;
336 }
337 DEBUG(D_acl)
338 debug_printf("\n-------------------------\nInput sent.\n-------------------------\n");
339
340 /********************************
341 * receiving output from dccifd *
342 ********************************/
343 DEBUG(D_acl)
344 debug_printf("\n-------------------------------------\nNow receiving output from server\n-----------------------------------\n");
345
346 /******************************************************************
347 * We should get 3 lines: *
348 * 1/ First line is overall result: either 'A' for Accept, *
349 * 'R' for Reject, 'S' for accept Some recipients or *
350 * 'T' for a Temporary error. *
351 * 2/ Second line contains the list of Accepted/Rejected *
352 * recipients in the form AARRA (A = accepted, R = rejected). *
353 * 3/ Third line contains the X-DCC header. *
354 ******************************************************************/
355
356 line = 1; /* we start at the first line of the output */
6a8f9482
TK
357 j = 0; /* will be used as index for the recipients list */
358 k = 0; /* initializing the index of the X-DCC header: xhdr[k] */
6a8f9482
TK
359
360 /* Let's read from the socket until there's nothing left to read */
361 bzero(recvbuf, sizeof(recvbuf));
7156b1ef 362 while((resp = read(sockfd, recvbuf, sizeof(recvbuf)-1)) > 0) {
6a8f9482
TK
363 /* How much did we get from the socket */
364 c = Ustrlen(recvbuf) + 1;
365 DEBUG(D_acl)
366 debug_printf("Length of the output buffer is: %d\nOutput buffer is:\n------------\n%s\n-----------\n", c, recvbuf);
367
368 /* Now let's read each character and see what we've got */
369 for(i = 0; i < c; i++) {
370 /* First check if we reached the end of the line and
371 * then increment the line counter */
372 if(recvbuf[i] == '\n') {
373 line++;
374 }
375 else {
376 /* The first character of the first line is the
377 * overall response. If there's another character
378 * on that line it is not correct. */
379 if(line == 1) {
380 if(i == 0) {
381 /* Now get the value and set the
382 * return value accordingly */
383 if(recvbuf[i] == 'A') {
384 DEBUG(D_acl)
385 debug_printf("Overall result = A\treturning OK\n");
386 Ustrcpy(dcc_return_text, "Mail accepted by DCC");
7156b1ef 387 dcc_result = US"A";
6a8f9482
TK
388 retval = OK;
389 }
390 else if(recvbuf[i] == 'R') {
391 DEBUG(D_acl)
392 debug_printf("Overall result = R\treturning FAIL\n");
7156b1ef 393 dcc_result = US"R";
6a8f9482
TK
394 retval = FAIL;
395 if(sender_host_name) {
396 log_write(0, LOG_MAIN, "H=%s [%s] F=<%s>: rejected by DCC", sender_host_name, sender_host_address, sender_address);
397 }
398 else {
399 log_write(0, LOG_MAIN, "H=[%s] F=<%s>: rejected by DCC", sender_host_address, sender_address);
400 }
401 Ustrncpy(dcc_return_text, dcc_reject_message, Ustrlen(dcc_reject_message) + 1);
402 }
403 else if(recvbuf[i] == 'S') {
404 DEBUG(D_acl)
405 debug_printf("Overall result = S\treturning OK\n");
406 Ustrcpy(dcc_return_text, "Not all recipients accepted by DCC");
1a9312b2
TK
407 /* Since we're in an ACL we want a global result
408 * so we accept for all */
7156b1ef 409 dcc_result = US"A";
6a8f9482
TK
410 retval = OK;
411 }
412 else if(recvbuf[i] == 'G') {
413 DEBUG(D_acl)
414 debug_printf("Overall result = G\treturning FAIL\n");
415 Ustrcpy(dcc_return_text, "Greylisted by DCC");
7156b1ef 416 dcc_result = US"G";
1a9312b2 417 retval = FAIL;
6a8f9482
TK
418 }
419 else if(recvbuf[i] == 'T') {
420 DEBUG(D_acl)
421 debug_printf("Overall result = T\treturning DEFER\n");
422 retval = DEFER;
423 log_write(0,LOG_MAIN,"Temporary error with DCC: %s\n", recvbuf);
424 Ustrcpy(dcc_return_text, "Temporary error with DCC");
7156b1ef 425 dcc_result = US"T";
6a8f9482
TK
426 }
427 else {
428 DEBUG(D_acl)
429 debug_printf("Overall result = something else\treturning DEFER\n");
430 retval = DEFER;
431 log_write(0,LOG_MAIN,"Unknown DCC response: %s\n", recvbuf);
432 Ustrcpy(dcc_return_text, "Unknown DCC response");
7156b1ef 433 dcc_result = US"T";
6a8f9482
TK
434 }
435 }
436 else {
437 /* We're on the first line but not on the first character,
438 * there must be something wrong. */
439 DEBUG(D_acl)
440 debug_printf("Line = %d but i = %d != 0 character is %c - This is wrong!\n", line, i, recvbuf[i]);
441 log_write(0,LOG_MAIN,"Wrong header from DCC, output is %s\n", recvbuf);
442 }
443 }
444 else if(line == 2) {
445 /* On the second line we get a list of
1a9312b2
TK
446 * answer for each recipient. We don't care about
447 * it because we're in an acl and so just take the
448 * global result. */
6a8f9482
TK
449 }
450 else if(line > 2) {
451 /* The third and following lines is the X-DCC header,
452 * so we store it in xhdr. */
453 /* check if we don't get more than what we can handle */
454 if(k < sizeof(xhdr)) { /* xhdr has a length of 120 */
6a8f9482
TK
455 xhdr[k] = recvbuf[i];
456 k++;
457 }
458 else {
459 DEBUG(D_acl)
460 debug_printf("We got more output than we can store in the X-DCC header. Truncating at 120 characters.\n");
461 }
462 }
463 else {
464 /* Wrong line number. There must be a problem with the output. */
465 DEBUG(D_acl)
466 debug_printf("Wrong line number in output. Line number is %d\n", line);
467 }
468 }
469 }
470 /* we reinitialize the output buffer before we read again */
471 bzero(recvbuf,sizeof(recvbuf));
472 }
473 /* We have read everything from the socket */
474
475 /* We need the terminate the X-DCC header with a '\n' character. This needs to be k-1
476 * for xhdr[k] contains '\0'. */
477 xhdr[k-1] = '\n';
478
479 /* Now let's sum up what we've got. */
480 DEBUG(D_acl)
1a9312b2 481 debug_printf("\n--------------------------\nOverall result = %d\nX-DCC header: %sReturn message: %s\ndcc_result: %s\n", retval, xhdr, dcc_return_text, dcc_result);
6a8f9482
TK
482
483 /* We only add the X-DCC header if it starts with X-DCC */
484 if(!(Ustrncmp(xhdr, "X-DCC", 5))){
485 dcc_header = xhdr;
486 if(dcc_direct_add_header) {
487 header_add(' ' , "%s", xhdr);
1a9312b2 488 /* since the MIME ACL already writes the .eml file to disk without DCC Header we've to erase it */
6a8f9482
TK
489 unspool_mbox();
490 }
491 }
492 else {
493 DEBUG(D_acl)
494 debug_printf("Wrong format of the X-DCC header: %s\n", xhdr);
495 }
496
1a9312b2
TK
497 /* check if we should add additional headers passed in acl_m_dcc_add_header */
498 if(dcc_direct_add_header) {
7156b1ef 499 if (((xtra_hdrs = expand_string(US"$acl_m_dcc_add_header")) != NULL) && (xtra_hdrs[0] != '\0')) {
1a9312b2
TK
500 Ustrncpy(dcc_xtra_hdrs, xtra_hdrs, sizeof(dcc_xtra_hdrs) - 2);
501 if (dcc_xtra_hdrs[Ustrlen(dcc_xtra_hdrs)-1] != '\n')
502 Ustrcat(dcc_xtra_hdrs, "\n");
503 header_add(' ', "%s", dcc_xtra_hdrs);
504 DEBUG(D_acl)
505 debug_printf("adding additional headers in $acl_m_dcc_add_header: %s", dcc_xtra_hdrs);
506 }
507 }
508
6a8f9482
TK
509 dcc_ok = 1;
510 /* Now return to exim main process */
511 DEBUG(D_acl)
1a9312b2 512 debug_printf("Before returning to exim main process:\nreturn_text = %s - retval = %d\ndcc_result = %s\n", dcc_return_text, retval, dcc_result);
6a8f9482
TK
513
514 (void)fclose(data_file);
6f0c431a
PP
515 dcc_rc = retval;
516 return dcc_rc;
6a8f9482
TK
517}
518
519#endif