1 /* $Cambridge: exim/src/src/dcc.c,v 1.4 2009/11/11 10:08:01 nm4 Exp $ */
3 /*************************************************
4 * Exim - an Internet mail transport agent *
5 *************************************************/
7 /* Copyright (c) Wolfgang Breyha 2005-2009
8 * Vienna University Computer Center
10 * See the file NOTICE for conditions of use and distribution.
13 /* This patch is based on code from Tom Kistners exiscan (ACL integration) and
14 * the DCC local_scan patch from Christopher Bodenstein */
16 /* Code for calling dccifd. Called from acl.c. */
19 #ifdef EXPERIMENTAL_DCC
23 uschar dcc_header_str[256];
24 uschar dcc_result_str[256];
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. */
31 int flushbuffer (int socket, uschar *buffer)
34 rsp = write(socket, buffer, Ustrlen(buffer));
36 debug_printf("Result of the write() = %d\n", rsp);
40 debug_printf("Error writing buffer to socket: %s\n", strerror(errno));
44 debug_printf("Wrote buffer to socket:\n%s\n", buffer);
50 int dcc_process(uschar **listptr) {
52 uschar *list = *listptr;
54 uschar *dcc_daemon_ip = US"";
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";
59 uschar *xtra_hdrs = NULL;
62 int i, j, k, c, retval, sockfd, servlen, resp, line;
64 struct sockaddr_un serv_addr;
65 struct sockaddr_in serv_addr_in;
66 struct hostent *ipaddress;
68 uschar sockip[40], client_ip[40];
70 uschar rcpt[128], from[128];
74 uschar dcc_return_text[1024];
75 uschar mbox_path[1024];
76 uschar message_subdir[2];
77 struct header_line *dcchdr;
78 uschar *dcc_acl_options;
79 uschar dcc_acl_options_buffer[10];
80 uschar dcc_xtra_hdrs[1024];
83 if ((dcc_acl_options = string_nextinlist(&list, &sep,
84 dcc_acl_options_buffer,
85 sizeof(dcc_acl_options_buffer))) != NULL)
87 /* parse 1st option */
88 if ( (strcmpic(dcc_acl_options,US"false") == 0) ||
89 (Ustrcmp(dcc_acl_options,"0") == 0) ) {
90 /* explicitly no matching */
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;
102 /* empty means "don't match anything" */
108 /* if we scanned this message last time, just return */
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)
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");
129 /* Initialize the variables */
131 bzero(sockip,sizeof(sockip));
132 if (dccifd_address) {
133 if (dccifd_address[0] == '/')
134 Ustrncpy(sockpath, dccifd_address, sizeof(sockpath));
136 if( sscanf(CS dccifd_address, "%s %u", sockip, &portnr) != 2) {
137 log_write(0, LOG_MAIN,
138 "dcc acl condition: warning - invalid dccifd address: '%s'", dccifd_address);
139 (void)fclose(data_file);
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 */
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){
156 Ustrncpy(client_ip, sender_host_address, sizeof(client_ip)-1);
158 /* sender_host_address is NULL which means it comes from localhost */
159 Ustrncpy(client_ip, dcc_default_ip_option, sizeof(client_ip)-1);
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)); */
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);
172 /* initialize the other variables */
173 dcchdr = header_list;
174 /* we set the default return value to DEFER */
177 bzero(sendbuf,sizeof(sendbuf));
178 bzero(xhdr,sizeof(xhdr));
179 bzero(rcpt,sizeof(rcpt));
180 bzero(from,sizeof(from));
182 /* send a null return path as "<>". */
183 if (Ustrlen(sender_address) > 0)
184 Ustrncpy(from, sender_address, sizeof(from));
186 Ustrncpy(from, "<>", sizeof(from));
187 Ustrncat(from, "\n", sizeof(from)-Ustrlen(from)-1);
189 /**************************************
190 * Now creating the socket connection *
191 **************************************/
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){
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);
208 /* Now connecting the socket (INET) */
209 if (connect(sockfd, (struct sockaddr *)&serv_addr_in, sizeof(serv_addr_in)) < 0){
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);
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);
222 servlen = Ustrlen(serv_addr.sun_path) + sizeof(serv_addr.sun_family);
223 if ((sockfd = socket(AF_UNIX, SOCK_STREAM,0)) < 0){
225 debug_printf("Creating socket failed: %s\n", strerror(errno));
226 log_write(0,LOG_REJECT,"Creating socket failed: %s\n", strerror(errno));
227 /* if we cannot create the socket, defer the mail */
228 (void)fclose(data_file);
231 /* Now connecting the socket (UNIX) */
232 if (connect(sockfd, (struct sockaddr *) &serv_addr, servlen) < 0){
234 debug_printf("Connecting socket failed: %s\n", strerror(errno));
235 log_write(0,LOG_REJECT,"Connecting socket failed: %s\n", strerror(errno));
236 /* if we cannot contact the socket, defer the mail */
237 (void)fclose(data_file);
241 /* the socket is open, now send the options to dccifd*/
243 debug_printf("\n---------------------------\nSocket opened; now sending input\n-----------------\n");
244 /* First, fill in the input buffer */
245 Ustrncpy(sendbuf, opts, sizeof(sendbuf));
246 Ustrncat(sendbuf, from, sizeof(sendbuf)-Ustrlen(sendbuf)-1);
250 debug_printf("opts = %s\nsender = %s\nrcpt count = %d\n", opts, from, recipients_count);
251 debug_printf("Sending options:\n****************************\n");
254 /* let's send each of the recipients to dccifd */
255 for (i = 0; i < recipients_count; i++){
257 debug_printf("recipient = %s\n",recipients_list[i].address);
258 if(Ustrlen(sendbuf) + Ustrlen(recipients_list[i].address) > sizeof(sendbuf))
261 debug_printf("Writing buffer: %s\n", sendbuf);
262 flushbuffer(sockfd, sendbuf);
263 bzero(sendbuf, sizeof(sendbuf));
265 Ustrncat(sendbuf, recipients_list[i].address, sizeof(sendbuf)-Ustrlen(sendbuf)-1);
266 Ustrncat(sendbuf, "\r\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
268 /* send a blank line between options and message */
269 Ustrncat(sendbuf, "\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
270 /* Now we send the input buffer */
272 debug_printf("%s\n****************************\n", sendbuf);
273 flushbuffer(sockfd, sendbuf);
275 /* now send the message */
276 /* Clear the input buffer */
277 bzero(sendbuf, sizeof(sendbuf));
278 /* First send the headers */
279 /* Now send the headers */
281 debug_printf("Sending headers:\n****************************\n");
282 Ustrncpy(sendbuf, dcchdr->text, sizeof(sendbuf)-2);
283 while((dcchdr=dcchdr->next)) {
284 if(dcchdr->slen > sizeof(sendbuf)-2) {
285 /* The size of the header is bigger than the size of
286 * the input buffer, so split it up in smaller parts. */
287 flushbuffer(sockfd, sendbuf);
288 bzero(sendbuf, sizeof(sendbuf));
290 while(j < dcchdr->slen)
292 for(i = 0; i < sizeof(sendbuf)-2; i++) {
293 sendbuf[i] = dcchdr->text[j];
296 flushbuffer(sockfd, sendbuf);
297 bzero(sendbuf, sizeof(sendbuf));
299 } else if(Ustrlen(sendbuf) + dcchdr->slen > sizeof(sendbuf)-2) {
300 flushbuffer(sockfd, sendbuf);
301 bzero(sendbuf, sizeof(sendbuf));
302 Ustrncpy(sendbuf, dcchdr->text, sizeof(sendbuf)-2);
304 Ustrncat(sendbuf, dcchdr->text, sizeof(sendbuf)-Ustrlen(sendbuf)-2);
308 /* a blank line separates header from body */
309 Ustrncat(sendbuf, "\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1);
310 flushbuffer(sockfd, sendbuf);
312 debug_printf("\n****************************\n%s", sendbuf);
314 /* Clear the input buffer */
315 bzero(sendbuf, sizeof(sendbuf));
317 /* now send the body */
319 debug_printf("Writing body:\n****************************\n");
320 (void)fseek(data_file, SPOOL_DATA_START_OFFSET, SEEK_SET);
321 while((fread(sendbuf, 1, sizeof(sendbuf)-1, data_file)) > 0) {
322 flushbuffer(sockfd, sendbuf);
323 bzero(sendbuf, sizeof(sendbuf));
326 debug_printf("\n****************************\n");
328 /* shutdown() the socket */
329 if(shutdown(sockfd, 1) < 0){
331 debug_printf("Couldn't shutdown socket: %s\n", strerror(errno));
332 log_write(0,LOG_MAIN,"Couldn't shutdown socket: %s\n", strerror(errno));
333 /* If there is a problem with the shutdown()
335 (void)fclose(data_file);
339 debug_printf("\n-------------------------\nInput sent.\n-------------------------\n");
341 /********************************
342 * receiving output from dccifd *
343 ********************************/
345 debug_printf("\n-------------------------------------\nNow receiving output from server\n-----------------------------------\n");
347 /******************************************************************
348 * We should get 3 lines: *
349 * 1/ First line is overall result: either 'A' for Accept, *
350 * 'R' for Reject, 'S' for accept Some recipients or *
351 * 'T' for a Temporary error. *
352 * 2/ Second line contains the list of Accepted/Rejected *
353 * recipients in the form AARRA (A = accepted, R = rejected). *
354 * 3/ Third line contains the X-DCC header. *
355 ******************************************************************/
357 line = 1; /* we start at the first line of the output */
358 j = 0; /* will be used as index for the recipients list */
359 k = 0; /* initializing the index of the X-DCC header: xhdr[k] */
361 /* Let's read from the socket until there's nothing left to read */
362 bzero(recvbuf, sizeof(recvbuf));
363 while((resp = read(sockfd, recvbuf, sizeof(recvbuf)-1)) > 0) {
364 /* How much did we get from the socket */
365 c = Ustrlen(recvbuf) + 1;
367 debug_printf("Length of the output buffer is: %d\nOutput buffer is:\n------------\n%s\n-----------\n", c, recvbuf);
369 /* Now let's read each character and see what we've got */
370 for(i = 0; i < c; i++) {
371 /* First check if we reached the end of the line and
372 * then increment the line counter */
373 if(recvbuf[i] == '\n') {
377 /* The first character of the first line is the
378 * overall response. If there's another character
379 * on that line it is not correct. */
382 /* Now get the value and set the
383 * return value accordingly */
384 if(recvbuf[i] == 'A') {
386 debug_printf("Overall result = A\treturning OK\n");
387 Ustrcpy(dcc_return_text, "Mail accepted by DCC");
391 else if(recvbuf[i] == 'R') {
393 debug_printf("Overall result = R\treturning FAIL\n");
396 if(sender_host_name) {
397 log_write(0, LOG_MAIN, "H=%s [%s] F=<%s>: rejected by DCC", sender_host_name, sender_host_address, sender_address);
400 log_write(0, LOG_MAIN, "H=[%s] F=<%s>: rejected by DCC", sender_host_address, sender_address);
402 Ustrncpy(dcc_return_text, dcc_reject_message, Ustrlen(dcc_reject_message) + 1);
404 else if(recvbuf[i] == 'S') {
406 debug_printf("Overall result = S\treturning OK\n");
407 Ustrcpy(dcc_return_text, "Not all recipients accepted by DCC");
408 /* Since we're in an ACL we want a global result
409 * so we accept for all */
413 else if(recvbuf[i] == 'G') {
415 debug_printf("Overall result = G\treturning FAIL\n");
416 Ustrcpy(dcc_return_text, "Greylisted by DCC");
420 else if(recvbuf[i] == 'T') {
422 debug_printf("Overall result = T\treturning DEFER\n");
424 log_write(0,LOG_MAIN,"Temporary error with DCC: %s\n", recvbuf);
425 Ustrcpy(dcc_return_text, "Temporary error with DCC");
430 debug_printf("Overall result = something else\treturning DEFER\n");
432 log_write(0,LOG_MAIN,"Unknown DCC response: %s\n", recvbuf);
433 Ustrcpy(dcc_return_text, "Unknown DCC response");
438 /* We're on the first line but not on the first character,
439 * there must be something wrong. */
441 debug_printf("Line = %d but i = %d != 0 character is %c - This is wrong!\n", line, i, recvbuf[i]);
442 log_write(0,LOG_MAIN,"Wrong header from DCC, output is %s\n", recvbuf);
446 /* On the second line we get a list of
447 * answer for each recipient. We don't care about
448 * it because we're in an acl and so just take the
452 /* The third and following lines is the X-DCC header,
453 * so we store it in xhdr. */
454 /* check if we don't get more than what we can handle */
455 if(k < sizeof(xhdr)) { /* xhdr has a length of 120 */
456 xhdr[k] = recvbuf[i];
461 debug_printf("We got more output than we can store in the X-DCC header. Truncating at 120 characters.\n");
465 /* Wrong line number. There must be a problem with the output. */
467 debug_printf("Wrong line number in output. Line number is %d\n", line);
471 /* we reinitialize the output buffer before we read again */
472 bzero(recvbuf,sizeof(recvbuf));
474 /* We have read everything from the socket */
476 /* We need the terminate the X-DCC header with a '\n' character. This needs to be k-1
477 * for xhdr[k] contains '\0'. */
480 /* Now let's sum up what we've got. */
482 debug_printf("\n--------------------------\nOverall result = %d\nX-DCC header: %sReturn message: %s\ndcc_result: %s\n", retval, xhdr, dcc_return_text, dcc_result);
484 /* We only add the X-DCC header if it starts with X-DCC */
485 if(!(Ustrncmp(xhdr, "X-DCC", 5))){
487 if(dcc_direct_add_header) {
488 header_add(' ' , "%s", xhdr);
489 /* since the MIME ACL already writes the .eml file to disk without DCC Header we've to erase it */
495 debug_printf("Wrong format of the X-DCC header: %s\n", xhdr);
498 /* check if we should add additional headers passed in acl_m_dcc_add_header */
499 if(dcc_direct_add_header) {
500 if (((xtra_hdrs = expand_string(US"$acl_m_dcc_add_header")) != NULL) && (xtra_hdrs[0] != '\0')) {
501 Ustrncpy(dcc_xtra_hdrs, xtra_hdrs, sizeof(dcc_xtra_hdrs) - 2);
502 if (dcc_xtra_hdrs[Ustrlen(dcc_xtra_hdrs)-1] != '\n')
503 Ustrcat(dcc_xtra_hdrs, "\n");
504 header_add(' ', "%s", dcc_xtra_hdrs);
506 debug_printf("adding additional headers in $acl_m_dcc_add_header: %s", dcc_xtra_hdrs);
511 /* Now return to exim main process */
513 debug_printf("Before returning to exim main process:\nreturn_text = %s - retval = %d\ndcc_result = %s\n", dcc_return_text, retval, dcc_result);
515 (void)fclose(data_file);