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
);