/************************************************* * Exim - an Internet mail transport agent * *************************************************/ /* Copyright (c) University of Cambridge 1995 - 1999 */ /* See the file NOTICE for conditions of use and distribution. */ /* Code for receiving a message and setting up spool files. */ #include "exim.h" #define header_maxheaders 500 /* Uncomment this definition to restore the code that recognizes LF only after CR for incoming SMTP from a remote host. */ /* #define STRICT_CRLF */ /************************************************* * Local static variables * *************************************************/ static FILE *data_file = NULL; static int data_fd = -1; static int message_sequence_number = 0; static int thismessage_size_limit = 0; static char last_message_id[MESSAGE_ID_LENGTH + 1]; static int last_received_time = 0; static char spool_name[256]; /************************************************* * Check space on spool and log partitions * *************************************************/ /* This function is called before accepting a message; if any thresholds are set, it checks them. If a message_size is supplied, it checks that there is enough space for that size plus the threshold - i.e. that the message won't reduce the space to the threshold. Not all OS have statvfs(); for those that don't, this function always returns TRUE. For some OS the old function and struct name statfs is used; that is handled by a macro, defined in exim.h. Arguments: msg_size the (estimated) size of an incoming message Returns: FALSE if there isn't enough space, or if the information cannot be obtained TRUE if no check was done or there is enough space */ BOOL accept_check_fs(int msg_size) { #ifdef HAVE_STATFS BOOL rc = TRUE; struct STATVFS statbuf; memset(&statbuf, 0, sizeof(statbuf)); /* The field names are macros, because not all OS have F_FAVAIL and it seems tidier to have a macro for F_BAVAIL as well. */ if (check_spool_space > 0 || msg_size > 0 || check_spool_inodes > 0) { if (STATVFS(spool_directory, &statbuf) != 0 || statbuf.F_BAVAIL < (check_spool_space + msg_size) / statbuf.F_FRSIZE || statbuf.F_FAVAIL < check_spool_inodes) rc = FALSE; DEBUG(5) debug_printf("spool directory %s space = %d blocks; inodes = %d; " "check_space = %d (%d blocks); inodes = %d; msg_size = %d (%d blocks)\n", spool_directory, statbuf.F_BAVAIL, statbuf.F_FAVAIL, check_spool_space, check_spool_space / statbuf.F_FRSIZE, check_spool_inodes, msg_size, msg_size / statbuf.F_FRSIZE); if (!rc) return FALSE; } /* Need to cut down the log file path to the directory. */ if (check_log_space > 0 || check_log_inodes > 0) { char *path; if (log_file_path[0] == 0) path = string_copy(spool_directory); else { char *cp; path = string_copy(log_file_path); if ((cp = strrchr(path, '/')) == NULL) { DEBUG(5) debug_printf("cannot find slash in %s\n", path); return FALSE; } *cp = 0; } if (STATVFS(path, &statbuf) != 0 || statbuf.F_BAVAIL < check_log_space / statbuf.F_FRSIZE || statbuf.F_FAVAIL < check_log_inodes) rc = FALSE; DEBUG(5) debug_printf("log directory %s space = %d blocks; inodes = %d; " "check_space = %d (%d blocks); inodes = %d\n", path, statbuf.F_BAVAIL, statbuf.F_FAVAIL, check_log_space, check_log_space / statbuf.F_FRSIZE, check_log_inodes); if (!rc) return FALSE; } #endif return TRUE; } /************************************************* * Bomb out while reading a message * *************************************************/ /* The common case of wanting to bomb out is if a SIGTERM or SIGINT is received, or if there is a timeout. A rarer case might be if the log files are screwed up and Exim can't open them to record a message's arrival. Handling that case is done by setting a flag to cause the log functions to call this function if there is an ultimate disaster. That is why it is globally accessible. Arguments: SMTP response to give if in an SMTP session Returns: it doesn't */ void accept_bomb_out(char *msg) { if (smtp_input) { if (!smtp_batched_input) { DEBUG(9) debug_printf("421 %s %s - closing connection.\n", primary_hostname, msg); fprintf(smtp_out, "421 %s %s - closing connection.\r\n", primary_hostname, msg); fflush(smtp_out); } else moan_smtp_batch(NULL, "421 %s - message abandoned", msg); } /* If spool_name is set, it contains the name of the data file that is being written. Unlink it before closing so that it cannot be picked up by a delivery process. Ensure that any header file is also removed. */ if (spool_name[0] != 0) { unlink(spool_name); spool_name[(int)strlen(spool_name) - 1] = 'H'; unlink(spool_name); } /* Now close the file if it is open, either as a fd or a stream, and then exit from the process. */ if (data_file != NULL) fclose(data_file); else if (data_fd >= 0) close(data_fd); exit(EXIT_FAILURE); } /************************************************* * Data read timeout * *************************************************/ /* Handler function for timeouts that occur while reading the data that comprises a message. Argument: the signal number Returns: nothing */ static void data_timeout_handler(int sig) { char *msg = NULL; sig = sig; /* Keep picky compilers happy */ if (smtp_input) { msg = "SMTP incoming data timeout"; log_write(4, LOG_MAIN, "SMTP data timeout (message abandoned)%s%s", (sender_fullhost != NULL)? " on connection from " : "", (sender_fullhost != NULL)? sender_fullhost : ""); } else { fprintf(stderr, "exim: timed out while reading - message abandoned\n"); log_write(4, LOG_MAIN, "timed out while reading local message"); } accept_bomb_out(msg); /* Does not return */ } /************************************************* * SIGTERM or SIGINT received * *************************************************/ /* Handler for SIGTERM or SIGINT signals that occur while reading the data that comprises a message. Argument: the signal number Returns: nothing */ static void data_sigterm_sigint_handler(int sig) { char *msg = NULL; if (smtp_input) { msg = "Service not available - SIGTERM or SIGINT received"; log_write(0, LOG_MAIN, "SMTP connection%s%s closed after %s", sender_fullhost? " from " : "", sender_fullhost? sender_fullhost : "", (sig == SIGTERM)? "SIGTERM" : "SIGINT"); } else { if (filter_test == NULL) { fprintf(stderr, "\nexim: %s received - message abandoned\n", (sig == SIGTERM)? "SIGTERM" : "SIGINT"); log_write(0, LOG_MAIN, "%s received while reading local message", (sig == SIGTERM)? "SIGTERM" : "SIGINT"); } } accept_bomb_out(msg); /* Does not return */ } /************************************************* * Add new recipient to list * *************************************************/ /* This function builds a list of recipient addresses in argc/argv format. Argument: receiver the next address to add to recipients_list orcpt the DSN orcpt field, if any (ignored if support not configured) flags address flags pno parent number for fixed aliases Returns: nothing */ void accept_add_recipient(char *receiver, char *orcpt, int flags, int pno) { if (recipients_count >= recipients_list_max) { recipient_item *oldlist = recipients_list; int oldmax = recipients_list_max; recipients_list_max = recipients_list_max? 2*recipients_list_max : 50; recipients_list = store_get(recipients_list_max * sizeof(recipient_item)); if (oldlist != NULL) memcpy(recipients_list, oldlist, oldmax * sizeof(recipient_item)); } #ifdef SUPPORT_DSN recipients_list[recipients_count].orcpt = orcpt; #else orcpt = orcpt; /* Keep picky compilers happy */ #endif recipients_list[recipients_count].address = receiver; recipients_list[recipients_count].flags = flags; recipients_list[recipients_count++].pno = pno; } /************************************************* * Read data portion of a non-SMTP message * *************************************************/ /* This function is called to read the remainder of a message (following the headers) when the input is not from SMTP - we are receiving a local message on a standard input stream. The message is always terminated by EOF, and is also terminated by a dot on a line by itself if the flag dot_ends is TRUE. Split the two cases for maximum efficiency. There is at least one broken MUA (dtmail) that sends CRLF via this interface. We pander slightly to it by having an option to drop *all* CRs. Arguments: fin a FILE from which to read the message fout a FILE to which to write the message Returns: FALSE if the message is too big; TRUE otherwise, even if there is an error while writing - a general check on the output file (using ferror()) is done later to pick up any error states. */ static BOOL read_message_data(FILE *fin, FILE *fout) { int ch_state; register int ch; /* Handle the case when only EOF terminates the message */ if (!dot_ends) { while ((ch = getc(fin)) != EOF) { if (drop_cr && ch == '\r') continue; if (fputc(ch, fout) == EOF) break; if (ch == '\n') body_linecount++; if (++message_size > thismessage_size_limit) return FALSE; } return TRUE; /* => not too big, not that there's been no error */ } /* Handle the case when a dot on its own or EOF terminate */ ch_state = 1; while ((ch = getc(fin)) != EOF) { if (drop_cr && ch == '\r') continue; switch (ch_state) { case 0: /* Normal state */ if (ch == '\n') { body_linecount++; ch_state = 1; } break; case 1: /* After "\n" */ if (ch == '.') { ch_state = 2; continue; } if (ch != '\n') ch_state = 0; break; case 2: /* After "\n." */ if (ch == '\n') return TRUE; if (message_size++, fputc('.', fout) == EOF) return TRUE; /* => not too big, not that there's been no error */ ch_state = 0; break; } if (fputc(ch, fout) == EOF) break; if (++message_size > thismessage_size_limit) return FALSE; } return TRUE; /* => not too big, not that there's been no error */ } /************************************************* * Read data portion of an SMTP message * *************************************************/ /* This function is called to read the remainder of an SMTP message (after the headers), or to skip over it when an error has occurred. In this case, the output file is passed as NULL. The function is global, because it is called from smtp_in.c for batch SMTP input, to skip a message after an error. If any line begins with a dot, that character is skipped. A timeout per-line is applied, and the input should only be successfully terminated by CR LF . CR LF unless it is local (non-network) SMTP, in which case the CRs are optional, but... FUDGE: It seems that sites on the net send out messages with just LF terminators, despite the warnings in the RFCs, and other MTAs handle this. So we make the CRs optional in all cases. Restore the original spec by uncommenting the #definition of STRICT_CRLF at the head of this file. Arguments: fin a FILE from which to read the message fout a FILE to which to write the message; NULL if skipping was_EOF if non_NULL, set TRUE if EOF was encountered (implying truncated message); should be FALSE on entry Returns: FALSE if the message is too big; TRUE otherwise, even if there is an error while writing - a general check on the output file (using ferror()) is done later to pick up any error states. */ BOOL accept_read_message_data_smtp(FILE *fin, FILE *fout, BOOL *was_EOF) { int ch_state = 0; register int ch; alarm(smtp_receive_timeout); /* Gets reset after each LF */ while ((ch = getc(fin)) != EOF) { if (ch == '\n') alarm(smtp_receive_timeout); switch (ch_state) { case 0: /* After LF or CRLF */ if (ch == '.') { ch_state = 3; continue; /* Don't ever write . after LF */ } ch_state = 1; /* Else fall through to handle as normal char. */ case 1: /* Normal state */ if (ch == '\n' #ifdef STRICT_CRLF && sender_local #endif ) { ch_state = 0; body_linecount++; } else if (ch == '\r') { ch_state = 2; continue; } break; case 2: /* After CR */ if (ch == '\n') { ch_state = 0; body_linecount++; } else { message_size++; if (fout != NULL && fputc('\r', fout) == EOF) goto END_SMTP_DATA; /* A few lines below */ if (ch != '\r') ch_state = 1; else continue; } break; case 3: /* After [CR] LF . */ if (ch == '\n' #ifdef STRICT_CRLF && sender_local #endif ) goto END_SMTP_DATA; /* A few lines below */ if (ch == '\r') { ch_state = 4; continue; } ch_state = 1; /* The dot itself is removed */ break; case 4: /* After [CR] LF . CR */ if (ch == '\n' || (message_size++, (fout != NULL && fputc('\r', fout) == EOF))) goto END_SMTP_DATA; /* A few lines below */ if (ch == '\r') { ch_state = 2; continue; } ch_state = 1; break; } /* Add the character to the spool file, unless skipping; then loop for the next. */ message_size++; if (fout != NULL) { if (fputc(ch, fout) == EOF) goto END_SMTP_DATA; if (message_size > thismessage_size_limit) { alarm(0); return FALSE; } } } /* Fall through here if EOF encountered. This indicates some kind of error, since a correct message is terminated by [CR] LF . [CR] LF. */ if (was_EOF != NULL) *was_EOF = TRUE; /* Goto is used to get here out of the middle of a switch inside the above loop. */ END_SMTP_DATA: alarm(0); smtp_reading_data = FALSE; return TRUE; /* => not too big, not that there's been no error */ } /************************************************* * Accept message * *************************************************/ /* Accept a message on the given input, and put it into a pair of spool files. Either a non-null list of recipients, or the extract flag will be true, or both. The flag sender_local is true for locally generated messages, and smtp_input is true if the message is to be handled using SMTP conventions about termination and lines starting with dots. For non-SMTP messages, dot_ends is true for dot-terminated messages. If a message was successfully read, message_id[0] will be non-zero. The general actions of this function are: . Read the headers of the message (if any) into a chain of store blocks. . If there is a "sender:" header and the message is locally originated, throw it away. . If recipients are to be extracted from the message, build the recipients list from the headers, removing any that were on the original recipients list (unless extract_addresses_remove_arguments is false), and at the same time, remove any bcc header that may be present. . Get the spool file for the data, sort out its unique name, open and lock it (but don't give it the name yet). . Generate a "Message-ID" header if the message doesn't have one. . Generate a "Received" header. . Ensure the recipients list is fully qualified and rewritten if necessary. . If there are any rewriting rules, apply them to the sender address and also to the headers. . If there is no from: header, generate one. . Otherwise, if the sender is local, check that from: is correct, and if not, generate a Sender header unless message comes from root. . Ensure the presence of "to" or "cc" or "bcc". . If there is no "date" header, generate one. . Copy the rest of the input, or up to a terminating "." if in SMTP or dot_ends mode, to the data file. Leave it open, to hold the lock. . Write the envelope and the headers to a new file. . Set the name for the header file; close it. . Set the name for the data file; close it. Because this function can potentially be called many times in a single SMTP connection, we must take care to free any store obtained by store_malloc(). However, with the new store arrangements, all store should be got by store_get(), as it will be automatically retrieved after the message is accepted. FUDGE: It seems that sites on the net send out messages with just LF terminators, despite the warnings in the RFCs, and other MTAs handle this. So we make the CRs optional in all cases. Restore the original spec by uncommenting the #definition of STRICT_CRLF at the head of this file. Arguments: fin a FILE to read the message from fout stdout when reading from stdin; the SMTP socket when reading from an SMTP connection. extract_recip TRUE if recipients are to be extracted from the message's headers Returns: TRUE there are more messages to be read (SMTP input) FALSE there are no more messages to be read (non-SMTP input or SMTP connection collapsed, or other failure) When reading a message for filter testing, the returned value indicates whether the headers (which is all that is read) were terminated by '.' or not. */ BOOL accept_msg(FILE *fin, FILE *fout, BOOL extract_recip) { int i; int msg_size; int header_count = 1; int process_info_len = (int)strlen(process_info); int error_rc = (error_handling == ERRORS_SENDER)? errors_sender_rc : EXIT_FAILURE; int header_size = 256; register int ptr = 0; BOOL dot_ended = FALSE; BOOL extracted_bcc = FALSE; BOOL extracted_ignored = FALSE; BOOL had_zero = FALSE; BOOL yield = FALSE; BOOL smtp_yield = TRUE; #ifdef STRICT_CRLF BOOL last_was_cr = FALSE; #endif flock_t lock_data; error_block *bad_addresses = NULL; /* Final message to give to SMTP caller */ char *smtp_reply = NULL; /* Working header pointers */ header_line *h, *next; /* Pointers to receive the addresses of headers we specifically check for. */ header_line *from_header = NULL; header_line *to_header = NULL; header_line *cc_header = NULL; header_line *bcc_header = NULL; header_line *date_header = NULL; header_line *subject_header = NULL; header_line *msgid_header = NULL; header_line *resentmsgid_header = NULL; /* Variables for use when building the Received: header. */ char *received; char *timestamp; /* Release any open files that might have been cached while preparing to accept the message - e.g. by verifying addresses - because reading a message might take a fair bit of real time. */ search_tidyup(); /* Initialize the chain of headers by setting up a place-holder for Received: header, pointed to by the global anchor variable. We keep header_last pointing to the end of the chain to make adding headers simple. */ header_list = header_last = store_get(sizeof(header_line)); header_list->next = NULL; header_list->type = htype_other; header_list->text = NULL; /* Control block for the next header to be read. */ next = store_get(sizeof(header_line)); next->text = store_get(header_size); /* Initialize message id to be null (indicating no message read), and the header names list to be the normal list. Indicate there is no data file open yet, initialize the size and warning count. */ message_id[0] = 0; header_names = header_names_normal; data_file = NULL; data_fd = -1; spool_name[0] = 0; message_size = 0; warning_count = 0; /* Initialize overall message size limit; this may get reduced later if message_size_limit_count_recipients is set. */ thismessage_size_limit = (message_size_limit <= 0)? INT_MAX : message_size_limit; /* While reading the message, body_linecount is computed. The full message_ linecount is set up only when the headers are read back in from the spool for delivery. */ body_linecount = 0; /* Remember the time of reception. Be defensive against time warps - on some systems there are apparently automatic clock correctors that can move the clock backwards. When several messages are being received by the same process, we must insist that the clock doesn't do this. */ received_time = time(NULL); if (received_time >= last_received_time) last_received_time = received_time; else received_time = last_received_time; /* If SMTP input, set the handler for timeout, and initialize the alarm - it gets reset after each newline. */ if (smtp_input) { os_non_restarting_signal(SIGALRM, data_timeout_handler); alarm(smtp_receive_timeout); } /* If not SMTP input, timeout happen only if configured. */ else if (accept_timeout > 0) { os_non_restarting_signal(SIGALRM, data_timeout_handler); alarm(accept_timeout); } /* SIGTERM and SIGINT are caught always. */ signal(SIGTERM, data_sigterm_sigint_handler); signal(SIGINT, data_sigterm_sigint_handler); /* Header lines in messages are not supposed to be very long, though when unfolded, to: and cc: headers can take up a lot of store. We must also cope with the possibility of junk being thrown at us. Start by getting 256 bytes for storing the header, and extend this as necessary using string_cat(). To cope with total lunacies, impose an upper limit on the length of a header line. Should there be a limit on the total number of header lines? The store will fill up if not. Better have one. We must also cope with the possibility of binary zeros in the data. Hence we cannot use fgets(). Folded header lines are joined into one string, leaving the '\n' characters inside them, so that writing them out reproduces the input. Loop for each character of each header; the next structure for chaining the header is set up already, with ptr the offset of the next character in next->text. */ for (;;) { int ch = getc(fin); /* If we hit EOF on a real SMTP connection, it's an error, since incoming SMTP must have a correct "." terminator. */ if (ch == EOF && smtp_input && !smtp_batched_input) { log_write(4, LOG_MAIN, "unexpected %s while reading SMTP data (header) " "from %s", sender_host_unknown? "EOF" : "disconnection", sender_host_unknown? sender_ident : sender_fullhost); smtp_reply = "554 Lost incoming connection"; smtp_yield = FALSE; goto TIDYUP; /* Skip to end of function */ } /* Handle failure due to a humungously long header line. Add what we have so far onto the headers list so that it gets reflected in any error message, and back up the just-read character. */ if (ptr >= HEADER_MAXLENGTH - 1) { ungetc(ch, fin); next->text[ptr] = 0; next->slen = ptr; next->type = htype_other; next->next = NULL; header_last->next = next; header_last = next; log_write(0, LOG_MAIN, "ridiculously long header received from %s " "(more than %d characters): message abandoned", sender_host_unknown? sender_ident : sender_fullhost, HEADER_MAXLENGTH - 1); if (smtp_input) { smtp_reply = "552 Header line is ridiculously overlong"; (void)accept_read_message_data_smtp(fin, NULL, NULL); /* Swallow */ goto TIDYUP; /* Skip to end of function */ } else { if (error_handling == ERRORS_SENDER) { if (!moan_to_sender(ERRMESS_VLONGHEADER, NULL, header_list->next, fin, FALSE)) error_rc = EXIT_FAILURE; } else fprintf(stderr, "exim: header line longer than %d characters " "received: message not accepted\n", HEADER_MAXLENGTH - 1); exit(error_rc); } } /* Not yet reached the large upper limit: see if we are at the current size limit - there must be at least two bytes left (for the char plus zero); if at the limit, extend the text buffer. This could have been done auto- matically using string_cat() but because this is a tightish loop storing only one character at a time, we choose to do it inline. Normally store_extend() will be able to extend the block; only at the end of a big store block will a copy be needed. */ if (ptr >= header_size - 2) { int oldsize = header_size; header_size += 256; if (!store_extend(next->text, oldsize, header_size)) { char *newtext = store_get(header_size); memcpy(newtext, next->text, ptr); next->text = newtext; } } /* Cope with receiving a binary zero. There is dispute about whether these should be allowed in RFC 822 messages. The middle view is that they should not be allowed in headers, at least. Exim takes this attitude at the moment. We can't just stomp on them here, because we don't know that this line is a header yet. Set a flag to cause scanning later. */ if (ch == 0) had_zero = TRUE; /* Test for termination. Lines in remote SMTP are terminated by CRLF, while those from data files use just LF. Treat LF in local SMTP input as a terminator too. Treat EOF as a line terminator always. FUDGE: There are sites out there that don't send CRs before their LFs, and other MTAs accept this. We are therefore forced into this "liberalisation" too. To undo it, uncomment the definition of STRICT_CRLF at the head of this file. */ if (ch != EOF && (ch != '\n' #ifdef STRICT_CRLF || (!sender_local && !last_was_cr) #endif )) /* This is not the end of the line. If this is SMTP input and this is the first character in the line and it is a "." character, ignore it unless the following character is CR or LF. This implements the dot- doubling rule, though header lines starting with dots aren't exactly common. They are legal in RFC 822, though. */ { if (ptr == 0 && ch == '.' && smtp_input) { ch = getc(fin); if (ch == '\r' || ch == '\n') { ungetc(ch, fin); ch = '.'; } } next->text[ptr++] = ch; /* Add to buffer */ #ifdef STRICT_CRLF last_was_cr = (ch == '\r'); #endif continue; /* With next input character */ } /* Input line terminated; remove CR from stored text for SMTP input or if drop_cr is set (for broken local MUAs). There is always space for at least two more characters. Put in the newline here. */ if ((smtp_input || drop_cr) && next->text[ptr-1] == '\r') ptr--; next->text[ptr++] = '\n'; /* A blank line signals the end of the headers; release the unwanted space and set next to NULL to indicate this. For SMTP input, or if the "dot_ends" flag is set, a line containing only "." also signals the end of the headers, since it is the end of the whole input. */ if (ptr == 1 || ((smtp_input || dot_ends) && ptr == 2 && next->text[0] == '.')) { store_reset(next); next = NULL; if (ptr == 2) { dot_ended = TRUE; /* Flag so no more gets read */ smtp_reading_data = FALSE; } break; } /* There is data in the line; see if the next input character is a whitespace character. If it is, we have a continuation of this header line. There is always space for at least one character at this point. */ if (ch != EOF) { int nextch = getc(fin); if (nextch == ' ' || nextch == '\t') { next->text[ptr++] = nextch; continue; /* Iterate the loop */ } else if (nextch != EOF) ungetc(nextch, fin); /* Leave for next time */ else ch = EOF; /* Cause main loop to exit at end */ } /* We have got to the real line end. Terminate the string and release store beyond it. If it turns out to be a real header, internal binary zeros will be squashed later. */ next->text[ptr] = 0; next->slen = ptr; store_reset(next->text + ptr + 1); /* Add the length into the running total and check against the overall limit. We don't expect to fail here, but if someone does send an infinite number of headers we want to catch them. Just stop reading headers - the code to read the body will then also hit the buffer. */ message_size += ptr; if (message_size > thismessage_size_limit) break; /* A line that is not syntactically correct for a header also marks the end of the headers. In this case, we leave next containing the first data line. This might actually be several lines because of the continuation logic applied above, but that doesn't matter. It turns out that smail, and presumably sendmail, accept leading lines of the form From ph10 Fri Jan 5 12:35 GMT 1996 in messages. The "mail" command on Solaris 2 sends such lines. I cannot find any documentation of this, but for compatibility it had better be accepted. Exim restricts it to the case of non-smtp messages, and treats it as an alternative to the -f command line option. Thus it is ignored except for trusted users or filter testing. Otherwise it is taken as the sender address, unless -f was used (sendmail compatibility). It further turns out that some UUCPs generate the From_line in a different format, e.g. From ph10 Fri, 7 Jan 97 14:00:00 GMT The regex for matching these things is now capable of recognizing both formats (including 2- and 4-digit years in the latter). In fact, the regex is now configurable, as is the expansion string to fish out the sender. Even further on it has been discovered that some broken clients send these lines in SMTP messages. There is now an option to ignore them from specified hosts or networks. Sigh. */ if (header_last == header_list && (!smtp_input || (sender_host_address != NULL && verify_check_net(&ignore_fromline_nets, &ignore_fromline_netlist)) || (sender_host_address == NULL && ignore_fromline_local) ) && regex_match_and_setup(regex_From, next->text, 0, -1)) { if ((trusted_caller || filter_test != NULL) && !sender_address_forced) { char *uucp_sender = expand_string(uucp_from_sender); if (uucp_sender == NULL) { log_write(0, LOG_MAIN|LOG_PANIC, "expansion of \"%s\" failed after matching " "\"From \" line: %s", uucp_from_sender, expand_string_message); } else { int start, end, domain; char *errmess; char *newsender = parse_extract_address(uucp_sender, &errmess, &start, &end, &domain, TRUE); if (newsender != NULL) { if (domain == 0 && newsender[0] != 0) newsender = rewrite_address_qualify(newsender, FALSE); sender_address = newsender; user_name = ""; sender_local = FALSE; if (filter_test != NULL) printf("Sender from \"From\" line: %s\n", sender_address); } } } } /* Not a leading "From " line. Check to see if it is a valid header line */ else { char *p = next->text; while (mac_isgraph(*p) && *p != ':') p++; while (isspace(*p)) p++; /* If not a valid header line, break from the header reading loop, leaving next != NULL, indicating that it holds the first line of the body. */ if (*p != ':') break; /* We have a valid header line. If there were any binary zeroes in the line, stomp on them here. */ if (had_zero) for (p = next->text; p < next->text + ptr; p++) if (*p == 0) *p = '?'; /* It is perfectly legal to have an empty continuation line at the end of a header, but it is confusing to humans looking at such messages, since it looks like a blank line. Reduce confusion by removing redundant white space at the end. We know that there is at least one printing character (the ':' tested for above) so there is no danger of running off the end. */ p = next->text + ptr - 2; for (;;) { while (*p == ' ' || *p == '\t') p--; if (*p != '\n') break; ptr = (p--) - next->text + 1; next->text[ptr] = 0; next->slen = ptr; } /* Add the header to the chain; check for a ridiculous number of headers and force an end if there are too many. */ next->type = htype_other; next->next = NULL; header_last->next = next; header_last = next; if (header_count++ >= header_maxheaders) { next = NULL; break; } /* If any resent- headers exist, change the pointer to the active header names. */ if (strncmpic(next->text, "resent-", 7) == 0) header_names = header_names_resent; } /* The line has been handled. If we have hit EOF, break out of the loop, indicating no pending data line. */ if (ch == EOF) { next = NULL; break; } /* Set up for the next header */ header_size = 256; next = store_get(sizeof(header_line)); next->text = store_get(header_size); ptr = 0; had_zero = FALSE; #ifdef STRICT_CRLF last_was_cr = FALSE; #endif if (smtp_input) alarm(smtp_receive_timeout); /* Reset the timer */ } /* Continues, starting to read the next header */ /* End of the headers. Cancel timeout if set. */ if (smtp_input) alarm(0); /* At this point, we have read all the headers into a data structure in main store. The first header is still the dummy placeholder for the Received: header we are going to generate a bit later on. If next != NULL, it contains the first data line - which terminated the headers before reaching a blank line (not the normal case). */ DEBUG(9) { debug_printf(">>Original headers:\n"); for (h = header_list->next; h != NULL; h = h->next) debug_printf("%s", h->text); debug_printf("\n"); if (next != NULL) debug_printf("%s", next->text); } /* If there is an RBL warning header to chain it on the end of the existing headers - no need to copy, since it will not be in store that is released after each message is received. */ if (rbl_header != NULL) { rbl_header->next = NULL; header_last->next = rbl_header; header_last = rbl_header; } /* End of file on a real SMTP connection is an error. If an incoming SMTP call is dropped immediately after valid headers, the next thing we will see is EOF. We must pick test for this specially, as further down the reading of the data is skipped if already at EOF. */ if (smtp_input && !smtp_batched_input && feof(fin)) { log_write(4, LOG_MAIN, "unexpected %s while reading SMTP data " "(after header) from %s", sender_host_unknown? "EOF" : "disconnection", sender_host_unknown? sender_ident : sender_fullhost); smtp_reply = "554 Lost incoming connection"; smtp_yield = FALSE; goto TIDYUP; /* Skip to end of function */ } /* If this is a filter test run and no headers were read, output a warning in case there is a mistake in the test message. */ if (filter_test != NULL && header_list->next == NULL) printf("Warning: no message headers read\n"); /* Scan the headers for those that we must test for. If any resent- headers exist, then we must use the set of resent- headers, and not use the others, as mandated by RFC 822. However, we keep both kinds of message-id, so that we can log message-id if resent-message-id does not exist in the presence of other resent- headers. If there is a "sender:" header (of the appropriate type) and the message is locally originated, mark it "old" so that it will not be transmitted with the message. The Return-path: header is supposed to be added to messages when they leave the SMTP system. We shouldn't receive messages that already contain Return-path. However, since exim generates Return-path: on local delivery, resent messages may well contain it. We therefore provide an option to remove any Return-path: headers on input. Removal actually means flagging as "old", which prevents the header being transmitted with the message. Similar remarks apply to the non-standard Delivery-date: and Envelope-to: headers. If we are testing a mail filter file, use the value of the Return-Path header to set up the return_path variable, which is not otherwise set. */ for (h = header_list->next; h != NULL; h = h->next) { if (header_checkname(h, "return-path", 11)) { if (return_path_remove) h->type = htype_old; if (filter_test != NULL) { char *start = h->text + 12; while (isspace(*start)) start++; return_path = string_copyn(start, (int)strlen(start) - 1); } } else if (header_checkname(h, header_names[hn_sender].name, header_names[hn_sender].len)) h->type = sender_local? htype_old : htype_sender; else if (header_checkname(h, header_names[hn_from].name, header_names[hn_from].len)) { from_header = h; h->type = htype_from; /* For Sendmail compatibility, if the From header consists of just the login id of the user who called Exim, rewrite it with the gecos field first. */ if (!smtp_input) { char *s = h->text + header_names[hn_from].len + 1; while (isspace(*s)) s++; if (strncmpic(s, user_login, h->slen - (s - h->text) - 1) == 0) { header_add(htype_other, "From: %s <%s@%s>\n", user_name, user_login, qualify_domain_sender); h->type = htype_old; DEBUG(9) debug_printf("rewrote \"From:\" header using gecos\n"); } } } else if (header_checkname(h, header_names[hn_to].name, header_names[hn_to].len)) { to_header = h; h->type = htype_to; } else if (header_checkname(h, header_names[hn_cc].name, header_names[hn_cc].len)) { cc_header = h; h->type = htype_cc; } else if (header_checkname(h, header_names[hn_bcc].name, header_names[hn_bcc].len)) { bcc_header = h; h->type = htype_bcc; } else if (header_checkname(h, header_names[hn_replyto].name, header_names[hn_replyto].len)) { bcc_header = h; h->type = htype_replyto; } else if (header_checkname(h, header_names[hn_date].name, header_names[hn_date].len)) date_header = h; else if (header_checkname(h, header_names[hn_subject].name, header_names[hn_subject].len)) subject_header = h; else if (header_checkname(h, "message-id", 10)) { msgid_header = h; h->type = htype_id; } else if (header_checkname(h, "resent-message-id", 17)) resentmsgid_header = h; else if (header_checkname(h, "received", 8)) h->type = htype_received; else if (header_checkname(h, "delivery-date", 13) && delivery_date_remove) h->type = htype_old; else if (header_checkname(h, "envelope-to", 11) && envelope_to_remove) h->type = htype_old; } /* Extract recipients from the headers if that is required (the -t option). Note that this is documented as being done *before* any address rewriting takes place. There are two possibilities: (1) According to sendmail documentation, any recipients already listed are to be REMOVED from the message, so we need to build a non-recipients tree for that list, because in subsequent processing this data is held in a tree and that's what the spool_write_header() function expects. Make sure that non-recipient addresses are fully qualified and rewritten if necessary. (2) It is reported that many sendmails and other MTAs do not in fact do what is documented, but add extracted recipients to those in the command line arguments. Therefore, there is an option to make Exim behave this way. */ if (extract_recip) { int rcount = 0; error_block **bnext = &bad_addresses; if (extract_addresses_remove_arguments) { while (recipients_count-- > 0) { char *s = rewrite_address(recipients_list[recipients_count].address, TRUE, TRUE); tree_add_nonrecipient(s, FALSE); } recipients_list = NULL; recipients_count = recipients_list_max = 0; } parse_allow_group = TRUE; /* Allow address group syntax */ /* Now scan the headers */ for (h = header_list->next; h != NULL; h = h->next) { if (h->type == htype_to || h->type == htype_cc || h->type == htype_bcc) { char *s = strchr(h->text, ':') + 1; while (isspace(*s)) s++; while (*s != 0) { char *ss = parse_find_address_end(s, FALSE); char *recipient, *errmess; int terminator = *ss; int start, end, domain; /* Check on maximum */ if (recipients_max > 0 && ++rcount > recipients_max) { if (error_handling == ERRORS_STDERR) { fprintf(stderr, "exim: too many recipients\n"); exit(EXIT_FAILURE); } else exit(moan_to_sender(ERRMESS_TOOMANYRECIP, NULL, NULL, stdin, FALSE)? error_rc : EXIT_FAILURE); } /* Temporarily terminate the string at this point, and extract the operative address within. */ *ss = 0; recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE); /* Keep a list of all the bad addresses so we can send a single error message at the end. However, an empty address is not an error; just ignore it. This can come from an empty group list like To: Recipients of list:; If there are no recipients at all, an error will occur later. */ if (recipient == NULL && strcmp(errmess, "empty address") != 0) { int len = (int)strlen(s); error_block *b = store_get(sizeof(error_block)); while (len > 0 && isspace(s[len-1])) len--; b->next = NULL; b->text1 = string_printing(string_copyn(s, len)); b->text2 = errmess; *bnext = b; bnext = &(b->next); } /* If the recipient is already in the nonrecipients tree, it must have appeared on the command line with the option extract_addresses_ remove_arguments set. Do not add it to the recipients, and keep a note that this has happened, in order to give a better error if there are no recipients left. */ else if (recipient != NULL) { if (tree_search_addr(tree_nonrecipients, recipient, FALSE) == NULL) accept_add_recipient(recipient, NULL, 0, 0); else extracted_ignored = TRUE; } /* Put back the terminator */ *ss = terminator; s = ss + (terminator? 1:0); while (isspace(*s)) s++; } /* If this was the bcc: header, mark it "old", which means it will be kept on the spool, but not transmitted as part of the message. */ if (h->type == htype_bcc) { h->type = htype_old; bcc_header = NULL; extracted_bcc = TRUE; } } } parse_allow_group = FALSE; /* Reset group syntax flags */ parse_found_group = FALSE; } /* Now that we have the recipients, we can adjust the maximum permitted message size if necessary. */ if (message_size_limit > 0 && message_size_limit_count_recipients && recipients_count > 1) thismessage_size_limit /= recipients_count; /* Now build the unique message id. From smail we copy the idea of using the current time in base-62 format. Smail adds to this the inode of the data file, but on fast processors this isn't good enough, because a message can be completely handled within one second, and another can then arrive and get the same inode and therefore the same message id. Instead we use the pid of this process plus a sequence number which gets reset when the time changes, because a single process is capable of receiving more than one message - indeed, an SMTP connection might stay for quite some time. Uniqueness now relies on the fact that process numbers operate on a fairly large cycle, so that it is unbelievably unlikely that a process could receive a message, finish, and another process with the same pid could be started to receive another message, all within the same second. There doesn't seem to be anything in the RFC which requires a message id to start with a letter, but Smail was changed to ensure this. The external form of the message id (as supplied by string expansion) therefore starts with an additional leading 'E'. The spool file names do not include this leading letter and it is not used internally. Note that string_base62() returns its data in a static storage block, so it must be copied before calling string_base62() again. It always returns exactly 6 characters. We use just 2 of these for the sequence number. This allows a single process to accept up to 62x62 messages in one second. I think it will be some time before processors are up to that... NOTE: If ever the format of message ids is changed, the regular expression for checking that a string is in this format must be updated in a corresponding way. It appears in the initializing code in exim.c. The macro MESSAGE_ID_LENGTH must also be changed to reflect the correct string length. MODIFICATION: The requirement to cope with host numbers so that a number of hosts can maintain unique ids has meant a change to the message id format. In practice, sequence numbers greater than 2 have very rarely been seen. So, if the host_number has been set we construct a value for the last two 62-digits as the value (seq * 256) + host_number. This permits sequence numbers up to 14, which we hope will be good enough. If these run out, wait for a second so that the time changes. */ strncpy(message_id, string_base62((long int)received_time), 6); message_id[6] = '-'; strncpy(message_id + 7, string_base62((long int)getpid()), 7); if (strncmp(message_id, last_message_id, MESSAGE_ID_LENGTH - 3) != 0) message_sequence_number = 0; /* Deal with the case where the host number has to be encoded with the sequence number. */ if (host_number_string != NULL) { /* This is, I hope, just defensive programming that won't ever need to be exercised! */ if (message_sequence_number > 14) { while (received_time <= last_received_time) { sleep(1); received_time = time(NULL); } last_received_time = received_time; strncpy(message_id, string_base62((long int)received_time), 6); message_sequence_number = 0; } sprintf(message_id + MESSAGE_ID_LENGTH - 3, "-%2s", string_base62((long int)(message_sequence_number++ *256)+host_number) + 4); } /* The non-host-number case */ else sprintf(message_id + MESSAGE_ID_LENGTH - 3, "-%2s", string_base62((long int)message_sequence_number++) + 4); /* Save for comparing with next one */ strcpy(last_message_id, message_id); /* Add the current message id onto the current process info string if it will fit. */ (void)string_format(process_info + process_info_len, PROCESS_INFO_SIZE - process_info_len, " id=%s", message_id); /* If we are using multiple input directories, set up the one for this message to be the least significant base-62 digit of the time of arrival. Otherwise ensure that it is an empty string. */ message_subdir[0] = split_spool_directory? message_id[5] : 0; /* Now that we have the message-id, if there is no message-id: header, generate one. This can be user-configured if required, but we had better flatten any illegal characters therein. */ if ((header_names == header_names_normal && msgid_header == NULL) || (header_names != header_names_normal && resentmsgid_header == NULL)) { BOOL use_default = TRUE; if (message_id_text != NULL) { char *e = expand_string(message_id_text); if (e != NULL) { if (*e != 0) { uschar *ee; for (ee = (uschar *)e; *ee != 0; ee++) if (mac_iscntrl_or_special(*ee)) *ee = '-'; header_add(htype_id, "%s: <%s.%s@%s>\n", header_names[hn_msgid].name, message_id_external, e, primary_hostname); use_default = FALSE; } } else log_write(0, LOG_MAIN|LOG_PANIC, "expansion of \"%s\" (message_id_header_text) " "failed: %s", message_id_text, expand_string_message); } if (use_default) header_add(htype_id, "%s: <%s@%s>\n", header_names[hn_msgid].name, message_id_external, primary_hostname); } /* Ensure the recipients list is fully qualified and rewritten. If we are to log recipients, first keep a copy of the raw ones. */ if (log_received_recipients) { raw_recipients = store_get(recipients_count * sizeof(char *)); for (i = 0; i < recipients_count; i++) raw_recipients[i] = string_copy(recipients_list[i].address); } for (i = 0; i < recipients_count; i++) recipients_list[i].address = rewrite_address(recipients_list[i].address, TRUE, TRUE); /* Generate our own Received: header. We must not do this earlier because the message_id is usually included in the expansion string for this header. We also want the recipients to be qualified, so that the "for" clause (which works only if there's a single recipient) shows the qualified address. Generate text for the received header by expanding the configured string, and also get the timestamp to put on the end of the text, as required by RFC 822. Note: the checking for too many Received: headers is handled by the delivery code. */ timestamp = expand_string("${tod_full}"); if (recipients_count == 1) received_for = recipients_list[0].address; received = expand_string(received_header_text); received_for = NULL; if (received == NULL) log_write(0, LOG_PANIC_DIE, "Expansion of \"%s\" (received_header_text) " "failed: %s", string_printing(received_header_text), expand_string_message); /* The first element on the header chain is reserved for the Received header, so all we have to do is fill in the text pointer. */ header_list->text = string_sprintf("%s; %s\n", received, timestamp); header_list->slen = (int)strlen(header_list->text); header_list->type = htype_received; /* If there are any rewriting rules, apply them to the sender address, unless it has already been rewitten as part of verification for SMTP input. */ if (rewrite_rules != NULL && !sender_address_rewritten && sender_address[0] != 0) { sender_address = rewrite_address(sender_address, FALSE, TRUE); DEBUG(5) debug_printf("rewritten sender = %s\n", sender_address); } /* The headers must all be run through rewrite_header, because it ensures that addresses are fully qualified, as well as applying any rewriting rules that may exist. Take care to keep the from_header pointer correct if it gets re-written. Note: start at second header; no point wasting time on Received. This rewriting is documented as happening *after* recipient addresses are taken from the headers by the -t command line option. */ for (h = header_list->next; h != NULL; h = h->next) { header_line *newh = rewrite_header(h, NULL, NULL); if (newh != NULL) { if (h == from_header) from_header = newh; h = newh; } } search_tidyup(); /* Free any cached resources */ /* At this point, the only one of the saved header variables containing addresses that is still valid if not NULL is from_header. We haven't bother to updated any of the others, since the code below merely tests for their being NULL. Beware, though, if any changes require anything else. */ /* If there is no from: header, generate one. If this is a delivery error from a non-local source, we can't generate a proper address. */ if (from_header == NULL) { if (sender_address[0] == 0) { if (!smtp_input || sender_local) header_add(htype_from, "%s: Mail Delivery System \n", header_names[hn_from].name, qualify_domain_sender); else header_add(htype_from, "%s: Remote Mail Delivery System <>\n", header_names[hn_from].name); } else { if (!smtp_input || sender_local) header_add(htype_from, "%s: %s%s%s%s\n", header_names[hn_from].name, user_name, (user_name[0] == 0)? "" : " <", sender_address, (user_name[0] == 0)? "" : ">"); else header_add(htype_from, "%s: %s\n", header_names[hn_from].name, sender_address); } } /* Otherwise, if the sender is local, check that from: is correct, and if not, generate a sender: header. Any previously-existing sender: header was removed above. Note that sender_local is TRUE only if the caller of exim is not trusted, or if a trusted caller did not supply a -f argument for non-smtp input. If the from: header contains more than one address, then the call to parse_extract_address fails, and a sender: header is inserted, as required. */ else if (sender_local) { BOOL make_sender = TRUE; int start, end, domain; char *errmess; char *from_address = parse_extract_address(strchr(from_header->text, ':') + 1, &errmess, &start, &end, &domain, FALSE); if (from_address != NULL && (strcmpic(sender_address, from_address) == 0 || (domain == 0 && strcmpic(from_address, user_login) == 0))) make_sender = FALSE; /* We have to cause the Sender header to be rewritten if there are appropriate rewriting rules, because even though sender_address has already been rewritten, the rewriting rules that apply to Sender: may not apply to it. */ if (make_sender) { header_add(htype_sender, "%s: %s <%s>\n", header_names[hn_sender].name, user_name, sender_address); (void) rewrite_header(header_last, NULL, NULL); } } /* A message is not legal unless it has at least one of "to", "cc", or "bcc". Note that although the minimal examples in RFC822 show just "to" or "bcc", the full syntax spec allows "cc" as well. If any resent- header exists, this applies to the set of resent- headers rather than the normal set. If we extracted recipients from bcc, then we simply add an empty bcc header, which is legal according to RFC 822. Do the same for input via SMTP - thus not disclosing possible bcc recipients. Otherwise (i.e. for a message whose envelope came in on the command line) generate to: from the envelope address fields, unless always_bcc is set. Don't bother if there are no recipients (an error case that is picked up below); such a message isn't going anywhere. */ if (recipients_count > 0 && to_header == NULL && bcc_header == NULL && cc_header == NULL) { if (extracted_bcc || smtp_input || always_bcc) header_add(htype_bcc, "%s:\n", header_names[hn_bcc].name); /* This is a bit tedious but is presumably rare. */ else { int i; int p = 0; int count = 0; char *temp; for (i = 0; i < recipients_count; i++) count += (int)strlen(recipients_list[i].address) + 3; temp = store_get(count); count = (int)strlen(header_names[hn_to].name) + 2; for (i = 0; i < recipients_count; i++) { int j = (int)strlen(recipients_list[i].address); if (i != 0) { if (count + j > 72) { strcpy(temp + p, ",\n "); p += 3; count = 0; } else { strcpy(temp + p, ", "); p += 2; count += 2; } } strcpy(temp + p, recipients_list[i].address); p += j; count += j; } /* Add new header. */ header_add(htype_to, "%s: %s\n", header_names[hn_to].name, temp); /**** We used to rewrite as well, but that is surely wrong, since the recipients have already been rewritten above. (void) rewrite_header(header_last, NULL, NULL); ****/ } } /* If there is no date header, generate one. */ if (date_header == NULL) header_add(htype_other, "%s: %s\n", header_names[hn_date].name, tod_stamp(tod_full)); /* Show the complete set of headers if debugging, and the next line if present. */ DEBUG(9) { debug_printf(">>Final headers:\n"); for (h = header_list; h != NULL; h = h->next) debug_printf("%c %s", h->type, h->text); debug_printf("\n"); if (next != NULL) debug_printf("%s", next->text); } /* The headers are now complete in store. If we are running in filter testing mode, that is all this function does. Return the value of dot_ended. */ if (filter_test != NULL) { process_info[process_info_len] = 0; return dot_ended; } /* If this is smtp_input, the sender is not local, and sender verification is requested, call the main checking function and arrange to reject the message if it fails. */ if (smtp_input && !sender_local && (sender_verify || sender_try_verify)) { char *errmess; int errcode; if (!verify_sender(&errcode, &errmess)) { if (!dot_ended) (void)accept_read_message_data_smtp(fin, NULL, NULL); /* Swallow */ smtp_reply = string_sprintf("%d rejected: %s <%s>", errcode, errmess, sender_address); /* Send the configurable message, if any */ smtp_send_prohibition_message(fout, errcode, "sender_verify"); /* Log the incident to the main and reject logs (the latter will log the headers), set no message current, and then skip to the end of this function. */ log_write(3, LOG_MAIN|LOG_REJECT, "rejected%s%s: %s <%s>", (sender_fullhost == NULL)? "" : " from ", (sender_fullhost == NULL)? "" : host_and_ident(), errmess, sender_address); message_id[0] = 0; goto TIDYUP; } } /* If configured to check the syntax of the headers, do so now. However, there is no point in checking the syntax of To: Cc: or Bcc: when -t is specified, as they will already have been checked by the address extracting code. */ if (headers_check_syntax) { header_line *h; for (h = header_list; h != NULL; h = h->next) { if (h->type == htype_from || h->type == htype_replyto || h->type == htype_sender || (!extract_recip && (h->type == htype_to || h->type == htype_cc || h->type == htype_bcc) )) { char *s = strchr(h->text, ':') + 1; while (isspace(*s)) s++; parse_allow_group = TRUE; /* Allow group syntax */ /* Loop for multiple addresses in the header */ while (*s != 0) { char *ss = parse_find_address_end(s, FALSE); char *recipient, *errmess; int terminator = *ss; int start, end, domain; /* Temporarily terminate the string at this point, and extract the operative address within. */ *ss = 0; recipient = parse_extract_address(s,&errmess,&start,&end,&domain,FALSE); *ss = terminator; if (recipient == NULL && strcmp(errmess, "empty address") != 0) { char hname[64]; char *t = h->text; char *tt = hname; while (*t != ':') *tt++ = *t++; *tt = 0; /* Arrange not to include any white space at the end in the error message. */ t = ss; while (t > s && isspace(t[-1])) t--; /* Add the address which failed to the error message, since in a header with very many addresses it is sometimes hard to spot which one is at fault. */ errmess = string_sprintf("%s: failing address is: %.*s", errmess, t-s, s); if (headers_checks_fail) { if (smtp_input) { if (!dot_ended) /* Swallow */ (void)accept_read_message_data_smtp(fin, NULL, NULL); smtp_reply = string_sprintf("550 Syntax error in '%s' header: %s", hname, errmess); log_write(3, LOG_MAIN|LOG_REJECT, "rejected from%s%s <%s>: " "syntax error in '%s' header: %s", (sender_fullhost == NULL)? "" : " ", (sender_fullhost == NULL)? "" : host_and_ident(), sender_address, hname, errmess); message_id[0] = 0; /* Indicate no message accepted */ goto TIDYUP; /* Skip to end of function */ } else { fprintf(stderr, "exim: syntax error in '%s' header: %s\n", hname, errmess); fclose(data_file); exit(EXIT_FAILURE); } } /* Just log warning message */ else log_write(3, LOG_REJECT, "warning: from%s%s <%s>: " "syntax error in '%s' header: %s", (sender_fullhost == NULL)? "" : " ", (sender_fullhost == NULL)? "" : host_and_ident(), sender_address, hname, errmess); } /* Advance to the next address */ s = ss + (terminator? 1:0); while (isspace(*s)) s++; } } } } /* If we are running in host checking mode, there is nothing more to do except swallow the rest of the input if necessary and end off. */ if (host_checking) { if (!dot_ended) (void)accept_read_message_data_smtp(fin, NULL, NULL); goto TIDYUP; } /* Open a new spool file for the data portion of the message. We need to access it both via a file descriptor and a stream. Try to make the directory if it isn't there. Note re use of sprintf: spool_directory is checked on input to be < 200 characters long. */ sprintf(spool_name, "%s/input/%s/%s-D", spool_directory, message_subdir, message_id); data_fd = open(spool_name, O_RDWR|O_CREAT|O_EXCL, SPOOL_MODE); if (data_fd < 0) { if (errno == ENOENT) { char temp[16]; sprintf(temp, "input/%s", message_subdir); if (message_subdir[0] == 0) temp[5] = 0; directory_make(spool_directory, temp, INPUT_DIRECTORY_MODE, TRUE); data_fd = open(spool_name, O_RDWR|O_CREAT|O_EXCL, SPOOL_MODE); } if (data_fd < 0) log_write(0, LOG_MAIN | LOG_PANIC_DIE, "Failed to create spool file %s: %s", spool_name, strerror(errno)); } /* Make sure the file's group is the Exim gid if exim_uid exists (can't have exim_uid set without exim_gid), and double-check the mode because the group setting doesn't always get set automatically. */ if (exim_uid_set) { fchown(data_fd, exim_uid, exim_gid); fchmod(data_fd, SPOOL_MODE); } /* We now have data file open. Build a stream for it and lock it. */ data_file = fdopen(data_fd, "w+"); lock_data.l_type = F_WRLCK; lock_data.l_whence = lock_data.l_start = lock_data.l_len = 0; if (fcntl(data_fd, F_SETLK, &lock_data) < 0) log_write(0, LOG_MAIN | LOG_PANIC_DIE, "Cannot lock %s", spool_name); /* We have an open, locked data file. Write the message id to it to make it self-identifying. Then read the remainder of the input of this message and write it to the data file. If the variable next != NULL, it contains the first data line (which was read as a header but then turned out not to have the right format); write it (remembering that it might contain binary zeros). The result of fwrite() isn't inspected; instead we call ferror() below. */ fprintf(data_file, "%s-D\n", message_id); if (next != NULL) { char *s = next->text; int len = next->slen; if (smtp_input && next->text[0] == '.') { s++; len--; } fwrite(s, 1, len, data_file); body_linecount++; /* Assumes only 1 line */ } /* Note that we might already be at end of file, or the logical end of file (indicated by '.'), or might have encountered an error while writing the message id or "next" line. */ if (!ferror(data_file) && !feof(fin) && !dot_ended) { BOOL smtp_EOF = FALSE; BOOL size_ok = smtp_input? accept_read_message_data_smtp(fin, data_file, &smtp_EOF) : read_message_data(fin, data_file); /* Handle premature termination of non-batched SMTP (can't happen for non-SMTP input) */ if (smtp_EOF && !smtp_batched_input) { unlink(spool_name); /* Lose data file when closed */ message_id[0] = 0; /* Indicate no message accepted */ log_write(4, LOG_MAIN, "unexpected %s while reading SMTP data " "from %s", sender_host_unknown? "EOF" : "disconnection", sender_host_unknown? sender_ident : sender_fullhost); smtp_reply = "554 Lost incoming connection"; smtp_yield = FALSE; goto TIDYUP; /* Skip to end of function */ } /* Handle message that is too big */ if (!size_ok) { unlink(spool_name); /* Lose the data file when closed */ if (smtp_input) { (void)accept_read_message_data_smtp(fin, NULL, NULL); /* Swallow */ smtp_reply = "552 Message too large"; log_write(2, LOG_MAIN|LOG_REJECT, "rejected%s%s%s%s%s <%s>: " "message too large: %d recipient%s size=%d max=%d", (sender_fullhost == NULL)? "" : " from ", (sender_fullhost == NULL)? "" : sender_fullhost, (sender_ident == NULL)? "" : " (", (sender_ident == NULL)? "" : sender_ident, (sender_ident == NULL)? "" : ")", sender_address, recipients_count, (recipients_count == 1)? "" : "s", message_size, thismessage_size_limit); message_id[0] = 0; /* Indicate no message accepted */ goto TIDYUP; /* Skip to end of function */ } else { fseek(data_file, (long int)data_start_offset, SEEK_SET); log_write(2, LOG_MAIN|LOG_REJECT, "rejected local message from <%s>: " "too large: %d recipient%s size=%d max=%d", sender_address, recipients_count, (recipients_count == 1)? "" : "s", message_size, thismessage_size_limit); if (error_handling == ERRORS_SENDER) { DEBUG(1) debug_printf("Data too large while reading input for " "message %s (%d read; limit is %d for %d recipient%s)\n", message_id, message_size, thismessage_size_limit, recipients_count, (recipients_count == 1)? "" : "s"); if (!moan_to_sender(ERRMESS_TOOBIG, NULL, header_list, data_file, FALSE)) error_rc = EXIT_FAILURE; } else fprintf(stderr, "exim: message too large\n"); fclose(data_file); exit(error_rc); } } } /* The message body has now been read into the data file. Call fflush() to empty the buffers in C, and then call fsync() to get the data written out onto the disc, as fflush() doesn't do this (or at least, it isn't documented as having to do this). If there was an I/O error on either input or output, attempt to send an error message, and unlink the spool file. For non-SMTP input we can then give up. Note that for SMTP input we must swallow the remainder of the input in cases of output errors, since the far end doesn't expect to see anything until the terminating dot line is sent. */ if (fflush(data_file) == EOF || ferror(data_file) || fsync(fileno(data_file)) < 0 || ferror(fin)) { unlink(spool_name); /* Lose the data file */ if (smtp_input) { if (ferror(fin)) smtp_reply = "451 Error in reading input data"; else { smtp_reply = "451 Error in writing spool file"; (void)accept_read_message_data_smtp(fin, NULL, NULL); /* Swallow */ } message_id[0] = 0; /* Indicate no message accepted */ goto TIDYUP; /* Skip to end of function */ } else { fseek(data_file, (long int)data_start_offset, SEEK_SET); if (error_handling == ERRORS_SENDER) { DEBUG(1) debug_printf("Error while %s file for message %s\n", ferror(fin)? "reading input" : "writing spool data", message_id); if (!moan_to_sender(ferror(fin)? ERRMESS_MESSAGEREAD : ERRMESS_SPOOLWRITE, NULL, header_list, data_file, FALSE)) error_rc = EXIT_FAILURE; } else fprintf(stderr, "exim: %s\n", ferror(fin)? "input read failure" : "spool write failure"); fclose(data_file); exit(error_rc); } } /* No I/O errors were encountered while writing the data file. */ DEBUG(9) debug_printf("Data file written for message %s\n", message_id); /* If there were any bad addresses in the headers (detected only if -t was specified), or if there were no recipients (possibly as a result of bad addresses), send a message to the sender of this message, or write it to stderr if the error handling option is set that way. We need to rewind the data file in order to read it. In the case of no recipients or stderr error writing, throw the data file away afterwards, and exit. (This can't be SMTP, which always ensures there's at least one syntactically good recipient address.) */ if (bad_addresses != NULL || recipients_count == 0) { DEBUG(2) { if (recipients_count == 0) debug_printf("*** No recipients\n"); if (bad_addresses != NULL) { error_block *eblock = bad_addresses; debug_printf("*** Bad address(es)\n"); while (eblock != NULL) { debug_printf(" %s: %s\n", eblock->text1, eblock->text2); eblock = eblock->next; } } } fseek(data_file, (long int)data_start_offset, SEEK_SET); /* If configured to send errors to the sender, but this fails, force a failure error code. We use a special one for no recipients so that it can be detected by the autoreply transport. Otherwise error_rc is set to errors_sender_rc, which is EXIT_FAILURE unless -oee was given, in which case it is EXIT_SUCCESS. */ if (error_handling == ERRORS_SENDER) { if (!moan_to_sender( (bad_addresses == NULL)? (extracted_ignored? ERRMESS_IGADDRESS : ERRMESS_NOADDRESS) : (recipients_list == NULL)? ERRMESS_BADNOADDRESS : ERRMESS_BADADDRESS, bad_addresses, header_list, data_file, FALSE)) error_rc = (bad_addresses == NULL)? EXIT_NORECIPIENTS : EXIT_FAILURE; } else { if (bad_addresses == NULL) { if (extracted_ignored) fprintf(stderr, "exim: all -t recipients overridden by command line\n"); else fprintf(stderr, "exim: no recipients in message\n"); } else { fprintf(stderr, "exim: invalid address%s", (bad_addresses->next == NULL)? ":" : "es:\n"); while (bad_addresses != NULL) { fprintf(stderr, " %s: %s\n", bad_addresses->text1, bad_addresses->text2); bad_addresses = bad_addresses->next; } } } if (recipients_count == 0 || error_handling == ERRORS_STDERR) { unlink(spool_name); fclose(data_file); exit(error_rc); } } /* Data file successfully written. Ignore signals while we are writing the header file. */ signal(SIGALRM, SIG_IGN); signal(SIGTERM, SIG_IGN); signal(SIGINT, SIG_IGN); /* Keep the data file open until we have written the header file, in order to hold onto the lock. If writing the header file fails, we have failed to accept this message. Ensure the first time flag is set in the newly-received message. */ deliver_firsttime = TRUE; if ((msg_size = spool_write_header(message_id)) < 0) { DEBUG(2) debug_printf("Failed to write header file for %s\n", message_id); unlink(spool_name); /* Lose the data file */ if (smtp_input) { smtp_reply = "451 Error in writing spool file"; message_id[0] = 0; /* Indicate no message accepted */ } else { fseek(data_file, (long int)data_start_offset, SEEK_SET); if (error_handling == ERRORS_SENDER) { if (!moan_to_sender(ERRMESS_SPOOLWRITE, NULL, header_list, data_file, FALSE)) error_rc = EXIT_FAILURE; } else fprintf(stderr, "exim: spool write failure\n"); fclose(data_file); exit(error_rc); } } /* Else log the arrival of a new message while the file is still locked, just in case the machine is *really* fast, and delivers it first! Include any message id that is in the message - since the syntax of a message id is actually an addr-spec, we can use the parse routine to canonicize it. */ else { char *errmess, *subject; struct stat statbuf; int start, end, domain; char *old_id = (resentmsgid_header != NULL)? resentmsgid_header->text : (msgid_header != NULL)? msgid_header->text : NULL; /* Reset signal handlers to ignore signals that previously would have caused the message to be abandoned. */ signal(SIGALRM, SIG_IGN); signal(SIGTERM, SIG_IGN); signal(SIGINT, SIG_IGN); /* If an addr-spec contains a quoted string, it can contain any characters except " \ and CR and so in particular it can contain NL! Therefore, make sure we use a printing-characters only version for the log. */ if (old_id != NULL) { old_id = parse_extract_address(strchr(old_id, ':') + 1, &errmess, &start, &end, &domain, FALSE); if (old_id != NULL) old_id = string_printing(old_id); } /* If subject logging is turned on, create suitable printing-character text. */ if (log_subject && subject_header != NULL) { int i; char *p, *ss; char *s = subject_header->text + 7; while (*s != ':') s++; while (isspace(*(++s))); ss = string_printing(s); strcpy(big_buffer, " T=\""); p = big_buffer + (int)strlen(big_buffer); /* Backslash-quote any double quotes or backslashes. If the string is not now empty, it will end in "\n", since all headers end with \n and string_printing() will have turned that into two characters. But if it was an empty subject the terminating \n was removed by isspace() above. */ if (*ss != 0) for (i = 0; i < 100 && ss[i+2] != 0; i++) { if (ss[i] == '\"' || ss[i] == '\\') *p++ = '\\'; *p++ = ss[i]; } *p++ = '\"'; *p = 0; subject = big_buffer; } else subject = ""; /* Add data size to header size */ fflush(data_file); fstat(data_fd, &statbuf); msg_size += statbuf.st_size - MESSAGE_ID_LENGTH - 3 + 1; /* Generate log entry, setting a flag to cause a call to accept_bomb_out() if the log cannot be opened. Do RBL logging here. */ accept_call_bombout = TRUE; log_write(0, LOG_MAIN | (log_received_recipients? LOG_RECIPIENTS : 0) | (log_received_sender? LOG_SENDER : 0), "<= %s%s%s%s%s%s%s%s%s S=%d%s%s%s", (sender_address[0] == 0)? "<>" : sender_address, (message_reference != NULL)? " R=" : "", (message_reference != NULL)? message_reference : "", (sender_fullhost != NULL)? " H=" : "", (sender_fullhost != NULL)? sender_fullhost : "", (sender_ident != NULL)? " U=" : "", (sender_ident != NULL)? sender_ident : "", (received_protocol != NULL)? " P=" : "", (received_protocol != NULL)? received_protocol : "", msg_size, (old_id != NULL)? " id=" : "", (old_id != NULL)? old_id : "", subject); if (rbl_host && rbl_log_headers) log_write(1, LOG_REJECT, "Message accepted from RBL host"); accept_call_bombout = FALSE; } /* Either a message has been successfully received and written to the two spool files, or an error in writing the spool has occurred for an SMTP message, or an SMTP message has been rejected because of a bad sender. (For a non-SMTP message we will have already given up because there's no point in carrying on!) In either event, we must now close (and thereby unlock) the data file. In the successful case, this leaves the message on the spool, ready for delivery. In the error case, the spool file will be deleted. Then tidy up store, interact with an SMTP call if necessary, and return. A fflush() was done earlier in the expectation that any write errors on the data file will be flushed(!) out thereby. Nevertheless, it is theoretically possible for fclose() to fail - but what to do? What has happened to the lock if this happens? */ TIDYUP: process_info[process_info_len] = 0; /* Remove message id */ if (data_file != NULL) fclose(data_file); /* Frees the lock */ /* Now reset signal handlers to their defaults */ signal(SIGALRM, SIG_DFL); signal(SIGTERM, SIG_DFL); signal(SIGINT, SIG_DFL); /* Tell an SMTP caller the state of play, and arrange to return the SMTP return value, which defaults TRUE - meaning there may be more incoming messages from this connection. For non-SMTP callers (where there is only ever one message), the default is FALSE. */ if (smtp_input) { yield = smtp_yield; /* Handle interactive SMTP callers */ if (!smtp_batched_input) { if (smtp_reply == NULL) { DEBUG(9) debug_printf("250 OK id=%s\n", message_id); fprintf(fout, "250 OK id=%s\r\n", message_id); if (host_checking) fprintf(stdout, "\n**** SMTP testing: that is not a real message id!\n\n"); } else { DEBUG(9) debug_printf("%s\n", smtp_reply); fprintf(fout, "%s\r\n", smtp_reply); } fflush(fout); } /* For batched SMTP, generate an error message on failure, and do nothing on success. */ else if (smtp_reply != NULL) moan_smtp_batch(NULL, smtp_reply); } /* Reset headers so that logging of rejects for a subsequent message doesn't include them. It is also important to set header_last = NULL before exiting from this function, as this prevents certain rewrites that might happen during subsequent verifying (of another incoming message) from trying to add headers when they shouldn't. */ header_list = header_last = NULL; return yield; /* TRUE if more messages (SMTP only) */ } /* End of accept.c */