/* $Cambridge: exim/src/src/dcc.c,v 1.1 2008/01/17 13:03:35 tom Exp $ */ /************************************************* * Exim - an Internet mail transport agent * *************************************************/ /* Copyright (c) Wolfgang Breyha 2005-2008 * Vienna University Computer Center * wbreyha@gmx.net * License: GPL */ /* This patch is based on code from Tom Kistners exiscan (ACL integration) and * the DCC local_scan patch from Christopher Bodenstein */ /* Code for calling dccifd. Called from acl.c. */ #include "exim.h" #ifdef EXPERIMENTAL_DCC #include "dcc.h" #include "unistd.h" uschar dcc_header_str[256]; uschar dcc_result_str[256]; int dcc_ok = 0; int dcc_rc = 0; /* This function takes a file descriptor and a buffer as input and * returns either 0 for success or errno in case of error. */ int flushbuffer (int socket, uschar *buffer) { int retval, rsp; rsp = write(socket, buffer, Ustrlen(buffer)); DEBUG(D_acl) debug_printf("Result of the write() = %d\n", rsp); if(rsp < 0) { DEBUG(D_acl) debug_printf("Error writing buffer to socket: %s\n", strerror(errno)); retval = errno; } else { DEBUG(D_acl) debug_printf("Wrote buffer to socket:\n%s\n", buffer); retval = 0; } return retval; } int dcc_process(uschar **listptr) { int sep = 0; uschar *list = *listptr; uschar *user_name; uschar *body_begin; uschar user_name_buffer[128]; unsigned long mbox_size; FILE *data_file; int dcc_sock; uschar dcc_buffer[32600]; uschar *dcc_daemon_ip = US""; int dcc_daemon_port = 6276; uschar *dcc_request = US"header"; uschar *dcc_default_ip_option = US"127.0.0.1"; uschar *dcc_ip_option = US""; uschar *dcc_helo_option = US"localhost"; uschar *dcc_reject_message = US"Rejected by DCC"; /* from local_scan */ int i, j, k, c, retval, sockfd, servlen, resp, rcpt_count, portnr, line; struct sockaddr_un serv_addr; struct sockaddr_in serv_addr_in; struct hostent *ipaddress; uschar sockpath[128]; uschar sockip[40], client_ip[40]; uschar opts[128]; uschar rcpt[128], from[128]; uschar sendbuf[4096]; uschar recvbuf[4096]; uschar xhdr[256]; uschar dcc_return_text[1024]; uschar mbox_path[1024]; uschar message_subdir[2]; struct header_line *dcchdr; struct recipient_item *dcc_rcpt = recipients_list; int some; uschar *dcc_acl_options; uschar dcc_acl_options_buffer[10]; int offset, result; uschar *p,*q; int override = 0; time_t start; struct sockaddr_un server; #ifndef NO_POLL_H struct pollfd pollfd; #endif /* stop compiler warning */ result = result; /* grep 1st option */ if ((dcc_acl_options = string_nextinlist(&list, &sep, dcc_acl_options_buffer, sizeof(dcc_acl_options_buffer))) != NULL) { /* parse 1st option */ if ( (strcmpic(dcc_acl_options,US"false") == 0) || (Ustrcmp(dcc_acl_options,"0") == 0) ) { /* explicitly no matching */ return FAIL; }; /* special cases (match anything except empty) */ if ( (strcmpic(dcc_acl_options,US"true") == 0) || (Ustrcmp(dcc_acl_options,"*") == 0) || (Ustrcmp(dcc_acl_options,"1") == 0) ) { dcc_acl_options = dcc_acl_options; }; } else { /* empty means "don't match anything" */ return FAIL; }; sep = 0; /* if we scanned this message last time, just return */ if ( dcc_ok ) return dcc_rc; /* open the spooled body */ message_subdir[1] = '\0'; for (i = 0; i < 2; i++) { message_subdir[0] = (split_spool_directory == (i == 0))? message_id[5] : 0; sprintf(CS mbox_path, "%s/input/%s/%s-D", spool_directory, message_subdir, message_id); data_file = Ufopen(mbox_path,"rb"); if (data_file != NULL) break; }; if (data_file == NULL) { /* error while spooling */ log_write(0, LOG_MAIN|LOG_PANIC, "dcc acl condition: error while opening spool file"); return DEFER; }; /* Initialize the variables */ bzero(sockip,sizeof(sockip)); if (dccifd_address) { if (dccifd_address[0] == '/') Ustrncpy(sockpath, dccifd_address, sizeof(sockpath)); else if( sscanf(CS dccifd_address, "%s %u", sockip, portnr) != 2) { log_write(0, LOG_MAIN, "dcc acl condition: warning - invalid dccifd address: '%s'", dccifd_address); (void)fclose(data_file); return DEFER; } } /* opts is what we send as dccifd options - see man dccifd */ /* We don't support any other option than 'header' so just copy that */ bzero(opts,sizeof(opts)); Ustrncpy(opts, "header", sizeof(opts)-1); Ustrncpy(client_ip, dcc_ip_option, sizeof(client_ip)-1); /* If the dcc_client_ip is not provided use the * sender_host_address or 127.0.0.1 if it is NULL */ DEBUG(D_acl) debug_printf("my_ip_option = %s - client_ip = %s - sender_host_address = %s\n", dcc_ip_option, client_ip, sender_host_address); if(!(Ustrcmp(client_ip, ""))){ /* Do we have a sender_host_address or is it NULL? */ if(sender_host_address){ /* check if it is an ipv6 address */ if(Ustrchr(sender_host_address, ':')){ /* This is an IPv6 address * For the moment we will not use it, but use 127.0.0.1 instead */ DEBUG(D_acl) debug_printf("IPv6 address!\n"); Ustrncpy(client_ip, dcc_default_ip_option, sizeof(client_ip)-1); } else { Ustrncpy(client_ip, sender_host_address, sizeof(client_ip)-1); } } else { /* sender_host_address is NULL which means it comes from localhost */ Ustrncpy(client_ip, dcc_default_ip_option, sizeof(client_ip)-1); } } DEBUG(D_acl) debug_printf("Client IP: %s\n", client_ip); Ustrncpy(sockip, dcc_daemon_ip, sizeof(sockip)-1); /* strncat(opts, my_request, strlen(my_request)); */ Ustrcat(opts, "\n"); Ustrncat(opts, client_ip, sizeof(opts)-Ustrlen(opts)-1); Ustrncat(opts, "\nHELO ", sizeof(opts)-Ustrlen(opts)-1); Ustrncat(opts, dcc_helo_option, sizeof(opts)-Ustrlen(opts)-2); Ustrcat(opts, "\n"); /* initialize the other variables */ dcchdr = header_list; rcpt_count = 0; /* we set the default return value to DEFER */ retval = DEFER; bzero(sendbuf,sizeof(sendbuf)); bzero(xhdr,sizeof(xhdr)); bzero(rcpt,sizeof(rcpt)); bzero(from,sizeof(from)); Ustrncpy(from, sender_address, sizeof(from)); Ustrncat(from, "\n", sizeof(from)-Ustrlen(from)-1); /************************************** * Now creating the socket connection * **************************************/ /* If there is a dcc_daemon_ip, we use a tcp socket, otherwise a UNIX socket */ if(Ustrcmp(sockip, "")){ ipaddress = gethostbyname((char *)sockip); bzero((char *) &serv_addr_in, sizeof(serv_addr_in)); serv_addr_in.sin_family = AF_INET; bcopy((char *)ipaddress->h_addr, (char *)&serv_addr_in.sin_addr.s_addr, ipaddress->h_length); serv_addr_in.sin_port = htons(portnr); if ((sockfd = socket(AF_INET, SOCK_STREAM,0)) < 0){ DEBUG(D_acl) debug_printf("Creating socket failed: %s\n", strerror(errno)); log_write(0,LOG_REJECT,"Creating socket failed: %s\n", strerror(errno)); /* if we cannot create the socket, defer the mail */ (void)fclose(data_file); return retval; } /* Now connecting the socket (INET) */ if (connect(sockfd, (struct sockaddr *)&serv_addr_in, sizeof(serv_addr_in)) < 0){ DEBUG(D_acl) debug_printf("Connecting socket failed: %s\n", strerror(errno)); log_write(0,LOG_REJECT,"Connecting socket failed: %s\n", strerror(errno)); /* if we cannot contact the socket, defer the mail */ (void)fclose(data_file); return retval; } } else { /* connecting to the dccifd UNIX socket */ bzero((char *)&serv_addr,sizeof(serv_addr)); serv_addr.sun_family = AF_UNIX; Ustrcpy(serv_addr.sun_path, sockpath); servlen = Ustrlen(serv_addr.sun_path) + sizeof(serv_addr.sun_family); if ((sockfd = socket(AF_UNIX, SOCK_STREAM,0)) < 0){ DEBUG(D_acl) debug_printf("Creating socket failed: %s\n", strerror(errno)); log_write(0,LOG_REJECT,"Creating socket failed: %s\n", strerror(errno)); /* if we cannot create the socket, defer the mail */ (void)fclose(data_file); return retval; } /* Now connecting the socket (UNIX) */ if (connect(sockfd, (struct sockaddr *) &serv_addr, servlen) < 0){ DEBUG(D_acl) debug_printf("Connecting socket failed: %s\n", strerror(errno)); log_write(0,LOG_REJECT,"Connecting socket failed: %s\n", strerror(errno)); /* if we cannot contact the socket, defer the mail */ (void)fclose(data_file); return retval; } } /* the socket is open, now send the options to dccifd*/ DEBUG(D_acl) debug_printf("\n---------------------------\nSocket opened; now sending input\n-----------------\n"); /* First, fill in the input buffer */ Ustrncpy(sendbuf, opts, sizeof(sendbuf)); Ustrncat(sendbuf, from, sizeof(sendbuf)-Ustrlen(sendbuf)-1); DEBUG(D_acl) { debug_printf("opts = %s\nsender = %s\nrcpt count = %d\n", opts, from, recipients_count); debug_printf("Sending options:\n****************************\n"); } /* let's send each of the recipients to dccifd */ for (i = 0; i < recipients_count; i++){ DEBUG(D_acl) debug_printf("recipient = %s\n",recipients_list[i].address); if(Ustrlen(sendbuf) + Ustrlen(recipients_list[i].address) > sizeof(sendbuf)) { DEBUG(D_acl) debug_printf("Writing buffer: %s\n", sendbuf); flushbuffer(sockfd, sendbuf); bzero(sendbuf, sizeof(sendbuf)); } Ustrncat(sendbuf, recipients_list[i].address, sizeof(sendbuf)-Ustrlen(sendbuf)-1); Ustrncat(sendbuf, "\r\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1); } /* send a blank line between options and message */ Ustrncat(sendbuf, "\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1); /* Now we send the input buffer */ DEBUG(D_acl) debug_printf("%s\n****************************\n", sendbuf); flushbuffer(sockfd, sendbuf); /* now send the message */ /* Clear the input buffer */ bzero(sendbuf, sizeof(sendbuf)); /* First send the headers */ /* Now send the headers */ DEBUG(D_acl) debug_printf("Sending headers:\n****************************\n"); Ustrncpy(sendbuf, dcchdr->text, sizeof(sendbuf)-2); while((dcchdr=dcchdr->next)) { if(dcchdr->slen > sizeof(sendbuf)-2) { /* The size of the header is bigger than the size of * the input buffer, so split it up in smaller parts. */ flushbuffer(sockfd, sendbuf); bzero(sendbuf, sizeof(sendbuf)); j = 0; while(j < dcchdr->slen) { for(i = 0; i < sizeof(sendbuf)-2; i++) { sendbuf[i] = dcchdr->text[j]; j++; } flushbuffer(sockfd, sendbuf); bzero(sendbuf, sizeof(sendbuf)); } } else if(Ustrlen(sendbuf) + dcchdr->slen > sizeof(sendbuf)-2) { flushbuffer(sockfd, sendbuf); bzero(sendbuf, sizeof(sendbuf)); Ustrncpy(sendbuf, dcchdr->text, sizeof(sendbuf)-2); } else { Ustrncat(sendbuf, dcchdr->text, sizeof(sendbuf)-Ustrlen(sendbuf)-2); } } /* a blank line separates header from body */ Ustrncat(sendbuf, "\n", sizeof(sendbuf)-Ustrlen(sendbuf)-1); flushbuffer(sockfd, sendbuf); DEBUG(D_acl) debug_printf("\n****************************\n", sendbuf); /* Clear the input buffer */ bzero(sendbuf, sizeof(sendbuf)); /* now send the body */ DEBUG(D_acl) debug_printf("Writing body:\n****************************\n"); (void)fseek(data_file, SPOOL_DATA_START_OFFSET, SEEK_SET); while((fread(sendbuf, 1, sizeof(sendbuf)-1, data_file)) > 0) { flushbuffer(sockfd, sendbuf); bzero(sendbuf, sizeof(sendbuf)); } DEBUG(D_acl) debug_printf("\n****************************\n"); /* shutdown() the socket */ if(shutdown(sockfd, 1) < 0){ DEBUG(D_acl) debug_printf("Couldn't shutdown socket: %s\n", strerror(errno)); log_write(0,LOG_MAIN,"Couldn't shutdown socket: %s\n", strerror(errno)); /* If there is a problem with the shutdown() * defer the mail. */ (void)fclose(data_file); return retval; } DEBUG(D_acl) debug_printf("\n-------------------------\nInput sent.\n-------------------------\n"); /******************************** * receiving output from dccifd * ********************************/ DEBUG(D_acl) debug_printf("\n-------------------------------------\nNow receiving output from server\n-----------------------------------\n"); /****************************************************************** * We should get 3 lines: * * 1/ First line is overall result: either 'A' for Accept, * * 'R' for Reject, 'S' for accept Some recipients or * * 'T' for a Temporary error. * * 2/ Second line contains the list of Accepted/Rejected * * recipients in the form AARRA (A = accepted, R = rejected). * * 3/ Third line contains the X-DCC header. * ******************************************************************/ line = 1; /* we start at the first line of the output */ rcpt_count = 0; /* initializing the recipients counter */ j = 0; /* will be used as index for the recipients list */ k = 0; /* initializing the index of the X-DCC header: xhdr[k] */ some = 0; /* Let's read from the socket until there's nothing left to read */ bzero(recvbuf, sizeof(recvbuf)); while(resp = read(sockfd, recvbuf, sizeof(recvbuf)-1) > 0) { /* How much did we get from the socket */ c = Ustrlen(recvbuf) + 1; DEBUG(D_acl) debug_printf("Length of the output buffer is: %d\nOutput buffer is:\n------------\n%s\n-----------\n", c, recvbuf); /* Now let's read each character and see what we've got */ for(i = 0; i < c; i++) { /* First check if we reached the end of the line and * then increment the line counter */ if(recvbuf[i] == '\n') { line++; } else { /* The first character of the first line is the * overall response. If there's another character * on that line it is not correct. */ if(line == 1) { if(i == 0) { /* Now get the value and set the * return value accordingly */ if(recvbuf[i] == 'A') { DEBUG(D_acl) debug_printf("Overall result = A\treturning OK\n"); Ustrcpy(dcc_return_text, "Mail accepted by DCC"); retval = OK; } else if(recvbuf[i] == 'R') { DEBUG(D_acl) debug_printf("Overall result = R\treturning FAIL\n"); retval = FAIL; if(sender_host_name) { log_write(0, LOG_MAIN, "H=%s [%s] F=<%s>: rejected by DCC", sender_host_name, sender_host_address, sender_address); } else { log_write(0, LOG_MAIN, "H=[%s] F=<%s>: rejected by DCC", sender_host_address, sender_address); } Ustrncpy(dcc_return_text, dcc_reject_message, Ustrlen(dcc_reject_message) + 1); } else if(recvbuf[i] == 'S') { DEBUG(D_acl) debug_printf("Overall result = S\treturning OK\n"); Ustrcpy(dcc_return_text, "Not all recipients accepted by DCC"); some = 1; retval = OK; } else if(recvbuf[i] == 'G') { DEBUG(D_acl) debug_printf("Overall result = G\treturning FAIL\n"); Ustrcpy(dcc_return_text, "Greylisted by DCC"); retval = DEFER; } else if(recvbuf[i] == 'T') { DEBUG(D_acl) debug_printf("Overall result = T\treturning DEFER\n"); retval = DEFER; log_write(0,LOG_MAIN,"Temporary error with DCC: %s\n", recvbuf); Ustrcpy(dcc_return_text, "Temporary error with DCC"); } else { DEBUG(D_acl) debug_printf("Overall result = something else\treturning DEFER\n"); retval = DEFER; log_write(0,LOG_MAIN,"Unknown DCC response: %s\n", recvbuf); Ustrcpy(dcc_return_text, "Unknown DCC response"); } } else { /* We're on the first line but not on the first character, * there must be something wrong. */ DEBUG(D_acl) debug_printf("Line = %d but i = %d != 0 character is %c - This is wrong!\n", line, i, recvbuf[i]); log_write(0,LOG_MAIN,"Wrong header from DCC, output is %s\n", recvbuf); } } else if(line == 2) { /* On the second line we get a list of * answer for each recipient */ /* We only need to copy the list of recipients if we * accept the mail i.e. if retval is LOCAL_SCAN_ACCEPT */ // I don't care about results "SOME" since we're in the DATA stage. So we've a global result if(some) { if(j > recipients_count - 1) { DEBUG(D_acl) debug_printf("More recipients returned than sent!\nSent %d recipients, got %d in return.\n", recipients_count, j); } else { if(recvbuf[i] == 'A') { DEBUG(D_acl) debug_printf("Accepted recipient: %c - %s\n", recvbuf[i], recipients_list[j].address); // Ustrcpy(dcc_rcpt[rcpt_count].address, recipients_list[j].address); rcpt_count++; } else { DEBUG(D_acl) debug_printf("Rejected recipient: %c - %s\n", recvbuf[i], recipients_list[j].address); } j++; } } else { DEBUG(D_acl) debug_printf("result was not SOME, so we take the overall result\n"); } } else if(line > 2) { /* The third and following lines is the X-DCC header, * so we store it in xhdr. */ /* check if we don't get more than what we can handle */ if(k < sizeof(xhdr)) { /* xhdr has a length of 120 */ // DEBUG(D_acl) // debug_printf("Writing X-DCC header: k = %d recvbuf[%d] = %c\n", k, i, recvbuf[i]); xhdr[k] = recvbuf[i]; k++; } else { DEBUG(D_acl) debug_printf("We got more output than we can store in the X-DCC header. Truncating at 120 characters.\n"); } } else { /* Wrong line number. There must be a problem with the output. */ DEBUG(D_acl) debug_printf("Wrong line number in output. Line number is %d\n", line); } } } /* we reinitialize the output buffer before we read again */ bzero(recvbuf,sizeof(recvbuf)); } /* We have read everything from the socket */ /* We need the terminate the X-DCC header with a '\n' character. This needs to be k-1 * for xhdr[k] contains '\0'. */ xhdr[k-1] = '\n'; /* Now let's sum up what we've got. */ DEBUG(D_acl) debug_printf("\n--------------------------\nOverall result = %d\nNumber of recipients accepted: %d\nX-DCC header: %s\nReturn message: %s\n", retval, rcpt_count, xhdr, dcc_return_text); /* If some recipients were rejected, then rcpt_count is * less than the original recipients_count. * Then reconstruct the recipients list for those accepted * recipients only. */ if((rcpt_count == 0) & (retval == OK)) { /* There should be at least 1 recipient; but who knows... */ DEBUG(D_acl) debug_printf("List of accepted recipients is 0!\n"); retval = FAIL; } else { /* if(rcpt_count < recipients_count) { recipients_count=0; for(i=0; i < rcpt_count; i++){ DEBUG(D_acl) debug_printf("Adding the new recipient: %s\n", dcc_rcpt[i].address); receive_add_recipient(dcc_rcpt[i].address, -1); } */ retval = OK; } /* We only add the X-DCC header if it starts with X-DCC */ if(!(Ustrncmp(xhdr, "X-DCC", 5))){ dcc_header = xhdr; if(dcc_direct_add_header) { header_add(' ' , "%s", xhdr); /* since the MIME ACL already writes the .eml file to disk without DCC Header we've to earase it */ unspool_mbox(); } } else { DEBUG(D_acl) debug_printf("Wrong format of the X-DCC header: %s\n", xhdr); } dcc_ok = 1; /* Now return to exim main process */ DEBUG(D_acl) debug_printf("Before returning to exim main process:\nreturn_text = %s - retval = %d\n", dcc_return_text, retval); (void)fclose(data_file); return retval; } #endif