1 /*************************************************
2 * Exim - an Internet mail transport agent *
3 *************************************************/
5 /* Copyright (c) Wolfgang Breyha 2005-2013
6 * Vienna University Computer Center
8 * See the file NOTICE for conditions of use and distribution.
11 /* This patch is based on code from Tom Kistners exiscan (ACL integration) and
12 * the DCC local_scan patch from Christopher Bodenstein */
14 /* Code for calling dccifd. Called from acl.c. */
17 #ifdef EXPERIMENTAL_DCC
21 uschar dcc_header_str
[256];
25 /* This function takes a file descriptor and a buffer as input and
26 * returns either 0 for success or errno in case of error. */
28 int flushbuffer (int socket
, uschar
*buffer
)
31 rsp
= write(socket
, buffer
, Ustrlen(buffer
));
33 debug_printf("DCC: Result of the write() = %d\n", rsp
);
37 debug_printf("DCC: Error writing buffer to socket: %s\n", strerror(errno
));
42 debug_printf("DCC: Wrote buffer to socket:\n%s\n", buffer
);
49 dcc_process(uschar
**listptr
)
52 const uschar
*list
= *listptr
;
54 uschar
*dcc_default_ip_option
= US
"127.0.0.1";
55 uschar
*dcc_helo_option
= US
"localhost";
56 uschar
*dcc_reject_message
= US
"Rejected by DCC";
57 uschar
*xtra_hdrs
= NULL
;
58 uschar
*override_client_ip
= NULL
;
61 int i
, j
, k
, c
, retval
, sockfd
, resp
, line
;
63 struct sockaddr_un serv_addr
;
64 struct sockaddr_in serv_addr_in
;
65 struct hostent
*ipaddress
;
67 uschar sockip
[40], client_ip
[40];
69 uschar rcpt
[128], from
[128];
72 uschar dcc_return_text
[1024];
73 uschar mbox_path
[1024];
74 uschar message_subdir
[2];
75 struct header_line
*dcchdr
;
76 uschar
*dcc_acl_options
;
77 uschar dcc_acl_options_buffer
[10];
78 uschar dcc_xtra_hdrs
[1024];
81 if ((dcc_acl_options
= string_nextinlist(&list
, &sep
,
82 dcc_acl_options_buffer
,
83 sizeof(dcc_acl_options_buffer
))) != NULL
)
85 /* parse 1st option */
86 if ( (strcmpic(dcc_acl_options
,US
"false") == 0) ||
87 (Ustrcmp(dcc_acl_options
,"0") == 0) ) {
88 /* explicitly no matching */
92 /* special cases (match anything except empty) */
93 if ( (strcmpic(dcc_acl_options
,US
"true") == 0) ||
94 (Ustrcmp(dcc_acl_options
,"*") == 0) ||
95 (Ustrcmp(dcc_acl_options
,"1") == 0) ) {
96 dcc_acl_options
= dcc_acl_options
;
100 /* empty means "don't match anything" */
106 /* if we scanned this message last time, just return */
110 /* open the spooled body */
111 message_subdir
[1] = '\0';
112 for (i
= 0; i
< 2; i
++) {
113 message_subdir
[0] = (split_spool_directory
== (i
== 0))? message_id
[5] : 0;
114 sprintf(CS mbox_path
, "%s/input/%s/%s-D", spool_directory
, message_subdir
, message_id
);
115 data_file
= Ufopen(mbox_path
,"rb");
116 if (data_file
!= NULL
)
120 if (data_file
== NULL
) {
121 /* error while spooling */
122 log_write(0, LOG_MAIN
|LOG_PANIC
,
123 "dcc acl condition: error while opening spool file");
127 /* Initialize the variables */
129 bzero(sockip
,sizeof(sockip
));
130 if (dccifd_address
) {
131 if (dccifd_address
[0] == '/')
132 Ustrncpy(sockpath
, dccifd_address
, sizeof(sockpath
));
134 if( sscanf(CS dccifd_address
, "%s %u", sockip
, &portnr
) != 2) {
135 log_write(0, LOG_MAIN
,
136 "dcc acl condition: warning - invalid dccifd address: '%s'", dccifd_address
);
137 (void)fclose(data_file
);
142 /* opts is what we send as dccifd options - see man dccifd */
143 /* We don't support any other option than 'header' so just copy that */
144 bzero(opts
,sizeof(opts
));
145 Ustrncpy(opts
, dccifd_options
, sizeof(opts
)-1);
146 /* if $acl_m_dcc_override_client_ip is set use it */
147 if (((override_client_ip
= expand_string(US
"$acl_m_dcc_override_client_ip")) != NULL
) &&
148 (override_client_ip
[0] != '\0')) {
149 Ustrncpy(client_ip
, override_client_ip
, sizeof(client_ip
)-1);
151 debug_printf("DCC: Client IP (overridden): %s\n", client_ip
);
153 else if(sender_host_address
) {
154 /* else if $sender_host_address is available use that? */
155 Ustrncpy(client_ip
, sender_host_address
, sizeof(client_ip
)-1);
157 debug_printf("DCC: Client IP (sender_host_address): %s\n", client_ip
);
160 /* sender_host_address is NULL which means it comes from localhost */
161 Ustrncpy(client_ip
, dcc_default_ip_option
, sizeof(client_ip
)-1);
163 debug_printf("DCC: Client IP (default): %s\n", client_ip
);
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(dcc_header_str
,sizeof(dcc_header_str
));
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 sockip contains an 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("DCC: Creating TCP socket connection failed: %s\n", strerror(errno
));
203 log_write(0,LOG_PANIC
,"DCC: Creating TCP socket connection 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("DCC: Connecting to TCP socket failed: %s\n", strerror(errno
));
212 log_write(0,LOG_PANIC
,"DCC: Connecting to TCP 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 if ((sockfd
= socket(AF_UNIX
, SOCK_STREAM
,0)) < 0){
224 debug_printf("DCC: Creating UNIX socket connection failed: %s\n", strerror(errno
));
225 log_write(0,LOG_PANIC
,"DCC: Creating UNIX socket connection failed: %s\n", strerror(errno
));
226 /* if we cannot create the socket, defer the mail */
227 (void)fclose(data_file
);
230 /* Now connecting the socket (UNIX) */
231 if (connect(sockfd
, (struct sockaddr
*) &serv_addr
, sizeof(serv_addr
)) < 0){
233 debug_printf("DCC: Connecting to UNIX socket failed: %s\n", strerror(errno
));
234 log_write(0,LOG_PANIC
,"DCC: Connecting to UNIX socket failed: %s\n", strerror(errno
));
235 /* if we cannot contact the socket, defer the mail */
236 (void)fclose(data_file
);
240 /* the socket is open, now send the options to dccifd*/
242 debug_printf("\nDCC: ---------------------------\nDCC: Socket opened; now sending input\nDCC: -----------------\n");
243 /* First, fill in the input buffer */
244 Ustrncpy(sendbuf
, opts
, sizeof(sendbuf
));
245 Ustrncat(sendbuf
, from
, sizeof(sendbuf
)-Ustrlen(sendbuf
)-1);
249 debug_printf("DCC: opts = %s\nDCC: sender = %s\nDCC: rcpt count = %d\n", opts
, from
, recipients_count
);
250 debug_printf("DCC: Sending options:\nDCC: ****************************\n");
253 /* let's send each of the recipients to dccifd */
254 for (i
= 0; i
< recipients_count
; i
++){
256 debug_printf("DCC: recipient = %s\n",recipients_list
[i
].address
);
257 if(Ustrlen(sendbuf
) + Ustrlen(recipients_list
[i
].address
) > sizeof(sendbuf
))
260 debug_printf("DCC: Writing buffer: %s\n", sendbuf
);
261 flushbuffer(sockfd
, sendbuf
);
262 bzero(sendbuf
, sizeof(sendbuf
));
264 Ustrncat(sendbuf
, recipients_list
[i
].address
, sizeof(sendbuf
)-Ustrlen(sendbuf
)-1);
265 Ustrncat(sendbuf
, "\r\n", sizeof(sendbuf
)-Ustrlen(sendbuf
)-1);
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 */
271 debug_printf("DCC: %s\nDCC: ****************************\n", sendbuf
);
272 flushbuffer(sockfd
, sendbuf
);
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 */
280 debug_printf("DCC: Sending headers:\nDCC: ****************************\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
));
289 while(j
< dcchdr
->slen
)
291 for(i
= 0; i
< sizeof(sendbuf
)-2; i
++) {
292 sendbuf
[i
] = dcchdr
->text
[j
];
295 flushbuffer(sockfd
, sendbuf
);
296 bzero(sendbuf
, sizeof(sendbuf
));
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);
303 Ustrncat(sendbuf
, dcchdr
->text
, sizeof(sendbuf
)-Ustrlen(sendbuf
)-2);
307 /* a blank line seperates header from body */
308 Ustrncat(sendbuf
, "\n", sizeof(sendbuf
)-Ustrlen(sendbuf
)-1);
309 flushbuffer(sockfd
, sendbuf
);
311 debug_printf("\nDCC: ****************************\n%s", sendbuf
);
313 /* Clear the input buffer */
314 bzero(sendbuf
, sizeof(sendbuf
));
316 /* now send the body */
318 debug_printf("DCC: Writing body:\nDCC: ****************************\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
));
325 debug_printf("\nDCC: ****************************\n");
327 /* shutdown() the socket */
328 if(shutdown(sockfd
, 1) < 0){
330 debug_printf("DCC: Couldn't shutdown socket: %s\n", strerror(errno
));
331 log_write(0,LOG_MAIN
,"DCC: Couldn't shutdown socket: %s\n", strerror(errno
));
332 /* If there is a problem with the shutdown()
334 (void)fclose(data_file
);
338 debug_printf("\nDCC: -------------------------\nDCC: Input sent.\nDCC: -------------------------\n");
340 /********************************
341 * receiving output from dccifd *
342 ********************************/
344 debug_printf("\nDCC: -------------------------------------\nDCC: Now receiving output from server\nDCC: -----------------------------------\n");
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 ******************************************************************/
356 line
= 1; /* we start at the first line of the output */
357 j
= 0; /* will be used as index for the recipients list */
358 k
= 0; /* initializing the index of the X-DCC header: dcc_header_str[k] */
360 /* Let's read from the socket until there's nothing left to read */
361 bzero(recvbuf
, sizeof(recvbuf
));
362 while((resp
= read(sockfd
, recvbuf
, sizeof(recvbuf
)-1)) > 0) {
363 /* How much did we get from the socket */
364 c
= Ustrlen(recvbuf
) + 1;
366 debug_printf("DCC: Length of the output buffer is: %d\nDCC: Output buffer is:\nDCC: ------------\nDCC: %s\nDCC: -----------\n", c
, recvbuf
);
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') {
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. */
381 /* Now get the value and set the
382 * return value accordingly */
383 if(recvbuf
[i
] == 'A') {
385 debug_printf("DCC: Overall result = A\treturning OK\n");
386 Ustrcpy(dcc_return_text
, "Mail accepted by DCC");
390 else if(recvbuf
[i
] == 'R') {
392 debug_printf("DCC: Overall result = R\treturning FAIL\n");
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
);
399 log_write(0, LOG_MAIN
, "H=[%s] F=<%s>: rejected by DCC", sender_host_address
, sender_address
);
401 Ustrncpy(dcc_return_text
, dcc_reject_message
, Ustrlen(dcc_reject_message
) + 1);
403 else if(recvbuf
[i
] == 'S') {
405 debug_printf("DCC: Overall result = S\treturning OK\n");
406 Ustrcpy(dcc_return_text
, "Not all recipients accepted by DCC");
407 /* Since we're in an ACL we want a global result
408 * so we accept for all */
412 else if(recvbuf
[i
] == 'G') {
414 debug_printf("DCC: Overall result = G\treturning FAIL\n");
415 Ustrcpy(dcc_return_text
, "Greylisted by DCC");
419 else if(recvbuf
[i
] == 'T') {
421 debug_printf("DCC: Overall result = T\treturning DEFER\n");
423 log_write(0,LOG_MAIN
,"Temporary error with DCC: %s\n", recvbuf
);
424 Ustrcpy(dcc_return_text
, "Temporary error with DCC");
429 debug_printf("DCC: Overall result = something else\treturning DEFER\n");
431 log_write(0,LOG_MAIN
,"Unknown DCC response: %s\n", recvbuf
);
432 Ustrcpy(dcc_return_text
, "Unknown DCC response");
437 /* We're on the first line but not on the first character,
438 * there must be something wrong. */
440 debug_printf("DCC: 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
);
445 /* On the second line we get a list of
446 * answers for each recipient. We don't care about
447 * it because we're in an acl and take the
451 /* The third and following lines are the X-DCC header,
452 * so we store it in dcc_header_str. */
453 /* check if we don't get more than we can handle */
454 if(k
< sizeof(dcc_header_str
)) {
455 dcc_header_str
[k
] = recvbuf
[i
];
460 debug_printf("DCC: We got more output than we can store in the X-DCC header. Truncating at 120 characters.\n");
464 /* Wrong line number. There must be a problem with the output. */
466 debug_printf("DCC: Wrong line number in output. Line number is %d\n", line
);
470 /* we reinitialize the output buffer before we read again */
471 bzero(recvbuf
,sizeof(recvbuf
));
473 /* We have read everything from the socket */
475 /* We need to terminate the X-DCC header with a '\n' character. This needs to be k-1
476 * since dcc_header_str[k] contains '\0'. */
477 dcc_header_str
[k
-1] = '\n';
479 /* Now let's sum up what we've got. */
481 debug_printf("\nDCC: --------------------------\nDCC: Overall result = %d\nDCC: X-DCC header: %sReturn message: %s\nDCC: dcc_result: %s\n", retval
, dcc_header_str
, dcc_return_text
, dcc_result
);
483 /* We only add the X-DCC header if it starts with X-DCC */
484 if(!(Ustrncmp(dcc_header_str
, "X-DCC", 5))){
485 dcc_header
= dcc_header_str
;
486 if(dcc_direct_add_header
) {
487 header_add(' ' , "%s", dcc_header_str
);
488 /* since the MIME ACL already writes the .eml file to disk without DCC Header we've to erase it */
494 debug_printf("DCC: Wrong format of the X-DCC header: %s\n", dcc_header_str
);
497 /* check if we should add additional headers passed in acl_m_dcc_add_header */
498 if(dcc_direct_add_header
) {
499 if (((xtra_hdrs
= expand_string(US
"$acl_m_dcc_add_header")) != NULL
) && (xtra_hdrs
[0] != '\0')) {
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
);
505 debug_printf("DCC: adding additional headers in $acl_m_dcc_add_header: %s", dcc_xtra_hdrs
);
510 /* Now return to exim main process */
512 debug_printf("DCC: Before returning to exim main process:\nDCC: return_text = %s - retval = %d\nDCC: dcc_result = %s\n", dcc_return_text
, retval
, dcc_result
);
514 (void)fclose(data_file
);