/*++ /* NAME /* cleanup_message 3 /* SUMMARY /* process message segment /* SYNOPSIS /* #include "cleanup.h" /* /* void cleanup_message(state, type, buf, len) /* CLEANUP_STATE *state; /* int type; /* const char *buf; /* ssize_t len; /* DESCRIPTION /* This module processes message content records and copies the /* result to the queue file. It validates the input, rewrites /* sender/recipient addresses to canonical form, inserts missing /* message headers, and extracts information from message headers /* to be used later when generating the extracted output segment. /* This routine absorbs but does not emit the content to extracted /* boundary record. /* /* Arguments: /* .IP state /* Queue file and message processing state. This state is updated /* as records are processed and as errors happen. /* .IP type /* Record type. /* .IP buf /* Record content. /* .IP len /* Record content length. /* LICENSE /* .ad /* .fi /* The Secure Mailer license must be distributed with this software. /* AUTHOR(S) /* Wietse Venema /* IBM T.J. Watson Research /* P.O. Box 704 /* Yorktown Heights, NY 10598, USA /* /* Wietse Venema /* Google, Inc. /* 111 8th Avenue /* New York, NY 10011, USA /*--*/ /* System library. */ #include #include #include #include #include #ifdef STRCASECMP_IN_STRINGS_H #include #endif /* Utility library. */ #include #include #include #include #include #include #include #include /* Global library. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Application-specific. */ #include "cleanup.h" /* cleanup_fold_header - wrap address list header */ static void cleanup_fold_header(CLEANUP_STATE *state, VSTRING *header_buf) { char *start_line = vstring_str(header_buf); char *end_line; char *next_line; char *line; /* * A rewritten address list contains one address per line. The code below * replaces newlines by spaces, to fit as many addresses on a line as * possible (without rearranging the order of addresses). Prepending * white space to the beginning of lines is delegated to the output * routine. */ for (line = start_line; line != 0; line = next_line) { end_line = line + strcspn(line, "\n"); if (line > start_line) { if (end_line - start_line < 70) { /* TAB counts as one */ line[-1] = ' '; } else { start_line = line; } } next_line = *end_line ? end_line + 1 : 0; } cleanup_out_header(state, header_buf); } /* cleanup_extract_internal - save unquoted copy of extracted address */ static char *cleanup_extract_internal(VSTRING *buffer, TOK822 *addr) { /* * A little routine to stash away a copy of an address that we extracted * from a message header line. */ tok822_internalize(buffer, addr->head, TOK822_STR_DEFL); return (mystrdup(vstring_str(buffer))); } /* cleanup_rewrite_sender - sender address rewriting */ static void cleanup_rewrite_sender(CLEANUP_STATE *state, const HEADER_OPTS *hdr_opts, VSTRING *header_buf) { TOK822 *tree; TOK822 **addr_list; TOK822 **tpp; int did_rewrite = 0; if (msg_verbose) msg_info("rewrite_sender: %s", hdr_opts->name); /* * Parse the header line, rewrite each address found, and regenerate the * header line. Finally, pipe the result through the header line folding * routine. */ tree = tok822_parse_limit(vstring_str(header_buf) + strlen(hdr_opts->name) + 1, var_token_limit); addr_list = tok822_grep(tree, TOK822_ADDR); for (tpp = addr_list; *tpp; tpp++) { did_rewrite |= cleanup_rewrite_tree(state->hdr_rewrite_context, *tpp); if (state->flags & CLEANUP_FLAG_MAP_OK) { if (cleanup_send_canon_maps && (cleanup_send_canon_flags & CLEANUP_CANON_FLAG_HDR_FROM)) did_rewrite |= cleanup_map11_tree(state, *tpp, cleanup_send_canon_maps, cleanup_ext_prop_mask & EXT_PROP_CANONICAL); if (cleanup_comm_canon_maps && (cleanup_comm_canon_flags & CLEANUP_CANON_FLAG_HDR_FROM)) did_rewrite |= cleanup_map11_tree(state, *tpp, cleanup_comm_canon_maps, cleanup_ext_prop_mask & EXT_PROP_CANONICAL); if (cleanup_masq_domains && (cleanup_masq_flags & CLEANUP_MASQ_FLAG_HDR_FROM)) did_rewrite |= cleanup_masquerade_tree(state, *tpp, cleanup_masq_domains); } } if (did_rewrite) { vstring_truncate(header_buf, strlen(hdr_opts->name)); vstring_strcat(header_buf, ": "); tok822_externalize(header_buf, tree, TOK822_STR_HEAD); } myfree((void *) addr_list); tok822_free_tree(tree); if ((hdr_opts->flags & HDR_OPT_DROP) == 0) { if (did_rewrite) cleanup_fold_header(state, header_buf); else cleanup_out_header(state, header_buf); } } /* cleanup_rewrite_recip - recipient address rewriting */ static void cleanup_rewrite_recip(CLEANUP_STATE *state, const HEADER_OPTS *hdr_opts, VSTRING *header_buf) { TOK822 *tree; TOK822 **addr_list; TOK822 **tpp; int did_rewrite = 0; if (msg_verbose) msg_info("rewrite_recip: %s", hdr_opts->name); /* * Parse the header line, rewrite each address found, and regenerate the * header line. Finally, pipe the result through the header line folding * routine. */ tree = tok822_parse_limit(vstring_str(header_buf) + strlen(hdr_opts->name) + 1, var_token_limit); addr_list = tok822_grep(tree, TOK822_ADDR); for (tpp = addr_list; *tpp; tpp++) { did_rewrite |= cleanup_rewrite_tree(state->hdr_rewrite_context, *tpp); if (state->flags & CLEANUP_FLAG_MAP_OK) { if (cleanup_rcpt_canon_maps && (cleanup_rcpt_canon_flags & CLEANUP_CANON_FLAG_HDR_RCPT)) did_rewrite |= cleanup_map11_tree(state, *tpp, cleanup_rcpt_canon_maps, cleanup_ext_prop_mask & EXT_PROP_CANONICAL); if (cleanup_comm_canon_maps && (cleanup_comm_canon_flags & CLEANUP_CANON_FLAG_HDR_RCPT)) did_rewrite |= cleanup_map11_tree(state, *tpp, cleanup_comm_canon_maps, cleanup_ext_prop_mask & EXT_PROP_CANONICAL); if (cleanup_masq_domains && (cleanup_masq_flags & CLEANUP_MASQ_FLAG_HDR_RCPT)) did_rewrite |= cleanup_masquerade_tree(state, *tpp, cleanup_masq_domains); } } if (did_rewrite) { vstring_truncate(header_buf, strlen(hdr_opts->name)); vstring_strcat(header_buf, ": "); tok822_externalize(header_buf, tree, TOK822_STR_HEAD); } myfree((void *) addr_list); tok822_free_tree(tree); if ((hdr_opts->flags & HDR_OPT_DROP) == 0) { if (did_rewrite) cleanup_fold_header(state, header_buf); else cleanup_out_header(state, header_buf); } } /* cleanup_act_log - log action with context */ static void cleanup_act_log(CLEANUP_STATE *state, const char *action, const char *class, const char *content, const char *text) { const char *attr; if ((attr = nvtable_find(state->attr, MAIL_ATTR_LOG_ORIGIN)) == 0) attr = "unknown"; vstring_sprintf(state->temp1, "%s: %s: %s %.200s from %s;", state->queue_id, action, class, content, attr); if (state->sender) vstring_sprintf_append(state->temp1, " from=<%s>", info_log_addr_form_sender(state->sender)); if (state->recip) vstring_sprintf_append(state->temp1, " to=<%s>", info_log_addr_form_recipient(state->recip)); if ((attr = nvtable_find(state->attr, MAIL_ATTR_LOG_PROTO_NAME)) != 0) vstring_sprintf_append(state->temp1, " proto=%s", attr); if ((attr = nvtable_find(state->attr, MAIL_ATTR_LOG_HELO_NAME)) != 0) vstring_sprintf_append(state->temp1, " helo=<%s>", attr); if (text && *text) vstring_sprintf_append(state->temp1, ": %s", text); msg_info("%s", vstring_str(state->temp1)); } #define CLEANUP_ACT_CTXT_HEADER "header" #define CLEANUP_ACT_CTXT_BODY "body" #define CLEANUP_ACT_CTXT_ANY "content" /* cleanup_act - act upon a header/body match */ static const char *cleanup_act(CLEANUP_STATE *state, char *context, const char *buf, const char *value, const char *map_class) { const char *optional_text = value + strcspn(value, " \t"); int command_len = optional_text - value; #ifdef DELAY_ACTION int defer_delay; #endif while (*optional_text && ISSPACE(*optional_text)) optional_text++; #define STREQUAL(x,y,l) (strncasecmp((x), (y), (l)) == 0 && (y)[l] == 0) #define CLEANUP_ACT_DROP 0 /* * CLEANUP_STAT_CONT and CLEANUP_STAT_DEFER both update the reason * attribute, but CLEANUP_STAT_DEFER takes precedence. It terminates * queue record processing, and prevents bounces from being sent. */ if (STREQUAL(value, "REJECT", command_len)) { const CLEANUP_STAT_DETAIL *detail; if (state->reason) myfree(state->reason); if (*optional_text) { state->reason = dsn_prepend("5.7.1", optional_text); if (*state->reason != '4' && *state->reason != '5') { msg_warn("bad DSN action in %s -- need 4.x.x or 5.x.x", optional_text); *state->reason = '4'; } } else { detail = cleanup_stat_detail(CLEANUP_STAT_CONT); state->reason = dsn_prepend(detail->dsn, detail->text); } if (*state->reason == '4') state->errs |= CLEANUP_STAT_DEFER; else state->errs |= CLEANUP_STAT_CONT; state->flags &= ~CLEANUP_FLAG_FILTER_ALL; cleanup_act_log(state, "reject", context, buf, state->reason); return (buf); } if (STREQUAL(value, "WARN", command_len)) { cleanup_act_log(state, "warning", context, buf, optional_text); return (buf); } if (STREQUAL(value, "INFO", command_len)) { cleanup_act_log(state, "info", context, buf, optional_text); return (buf); } if (STREQUAL(value, "FILTER", command_len)) { if (*optional_text == 0) { msg_warn("missing FILTER command argument in %s map", map_class); } else if (strchr(optional_text, ':') == 0) { msg_warn("bad FILTER command %s in %s -- " "need transport:destination", optional_text, map_class); } else { if (state->filter) myfree(state->filter); state->filter = mystrdup(optional_text); cleanup_act_log(state, "filter", context, buf, optional_text); } return (buf); } if (STREQUAL(value, "PASS", command_len)) { cleanup_act_log(state, "pass", context, buf, optional_text); state->flags &= ~CLEANUP_FLAG_FILTER_ALL; return (buf); } if (STREQUAL(value, "DISCARD", command_len)) { cleanup_act_log(state, "discard", context, buf, optional_text); state->flags |= CLEANUP_FLAG_DISCARD; state->flags &= ~CLEANUP_FLAG_FILTER_ALL; return (buf); } if (STREQUAL(value, "HOLD", command_len)) { if ((state->flags & (CLEANUP_FLAG_HOLD | CLEANUP_FLAG_DISCARD)) == 0) { cleanup_act_log(state, "hold", context, buf, optional_text); state->flags |= CLEANUP_FLAG_HOLD; } return (buf); } /* * The DELAY feature is disabled because it has too many problems. 1) It * does not work on some remote file systems; 2) mail will be delivered * anyway with "sendmail -q" etc.; 3) while the mail is queued it bogs * down the deferred queue scan with huge amounts of useless disk I/O * operations. */ #ifdef DELAY_ACTION if (STREQUAL(value, "DELAY", command_len)) { if ((state->flags & (CLEANUP_FLAG_HOLD | CLEANUP_FLAG_DISCARD)) == 0) { if (*optional_text == 0) { msg_warn("missing DELAY argument in %s map", map_class); } else if (conv_time(optional_text, &defer_delay, 's') == 0) { msg_warn("ignoring bad DELAY argument %s in %s map", optional_text, map_class); } else { cleanup_act_log(state, "delay", context, buf, optional_text); state->defer_delay = defer_delay; } } return (buf); } #endif if (STREQUAL(value, "PREPEND", command_len)) { if (*optional_text == 0) { msg_warn("PREPEND action without text in %s map", map_class); } else if (strcmp(context, CLEANUP_ACT_CTXT_HEADER) == 0) { if (!is_header(optional_text)) { msg_warn("bad PREPEND header text \"%s\" in %s map -- " "need \"headername: headervalue\"", optional_text, map_class); } /* * By design, cleanup_out_header() may modify content. Play safe * and prepare for future developments. */ else { VSTRING *temp; cleanup_act_log(state, "prepend", context, buf, optional_text); temp = vstring_strcpy(vstring_alloc(strlen(optional_text)), optional_text); cleanup_out_header(state, temp); vstring_free(temp); } } else { cleanup_act_log(state, "prepend", context, buf, optional_text); cleanup_out_string(state, REC_TYPE_NORM, optional_text); } return (buf); } if (STREQUAL(value, "REPLACE", command_len)) { if (*optional_text == 0) { msg_warn("REPLACE action without text in %s map", map_class); return (buf); } else if (strcmp(context, CLEANUP_ACT_CTXT_HEADER) == 0 && !is_header(optional_text)) { msg_warn("bad REPLACE header text \"%s\" in %s map -- " "need \"headername: headervalue\"", optional_text, map_class); return (buf); } else { cleanup_act_log(state, "replace", context, buf, optional_text); return (mystrdup(optional_text)); } } if (STREQUAL(value, "REDIRECT", command_len)) { if (strchr(optional_text, '@') == 0) { msg_warn("bad REDIRECT target \"%s\" in %s map -- " "need user@domain", optional_text, map_class); } else { if (state->redirect) myfree(state->redirect); state->redirect = mystrdup(optional_text); cleanup_act_log(state, "redirect", context, buf, optional_text); state->flags &= ~CLEANUP_FLAG_FILTER_ALL; } return (buf); } if (STREQUAL(value, "BCC", command_len)) { if (strchr(optional_text, '@') == 0) { msg_warn("bad BCC address \"%s\" in %s map -- " "need user@domain", optional_text, map_class); } else { if (state->hbc_rcpt == 0) state->hbc_rcpt = argv_alloc(1); argv_add(state->hbc_rcpt, optional_text, (char *) 0); cleanup_act_log(state, "bcc", context, buf, optional_text); } return (buf); } if (STREQUAL(value, "STRIP", command_len)) { cleanup_act_log(state, "strip", context, buf, optional_text); return (CLEANUP_ACT_DROP); } /* Allow and ignore optional text after the action. */ if (STREQUAL(value, "IGNORE", command_len)) return (CLEANUP_ACT_DROP); if (STREQUAL(value, "DUNNO", command_len)) /* preferred */ return (buf); if (STREQUAL(value, "OK", command_len)) /* compat */ return (buf); msg_warn("unknown command in %s map: %s", map_class, value); return (buf); } /* cleanup_header_callback - process one complete header line */ static void cleanup_header_callback(void *context, int header_class, const HEADER_OPTS *hdr_opts, VSTRING *header_buf, off_t unused_offset) { CLEANUP_STATE *state = (CLEANUP_STATE *) context; const char *myname = "cleanup_header_callback"; char *hdrval; struct code_map { const char *name; const char *encoding; }; static struct code_map code_map[] = { /* RFC 2045 */ "7bit", MAIL_ATTR_ENC_7BIT, "8bit", MAIL_ATTR_ENC_8BIT, "binary", MAIL_ATTR_ENC_8BIT, /* XXX Violation */ "quoted-printable", MAIL_ATTR_ENC_7BIT, "base64", MAIL_ATTR_ENC_7BIT, 0, }; struct code_map *cmp; MAPS *checks; const char *map_class; if (msg_verbose) msg_info("%s: '%.200s'", myname, vstring_str(header_buf)); /* * Crude header filtering. This stops malware that isn't sophisticated * enough to use fancy header encodings. */ #define CHECK(class, maps, var_name) \ (header_class == class && (map_class = var_name, checks = maps) != 0) if (hdr_opts && (hdr_opts->flags & HDR_OPT_MIME)) header_class = MIME_HDR_MULTIPART; /* Update the Received: header count before maybe dropping headers below. */ if (hdr_opts && hdr_opts->type == HDR_RECEIVED) state->hop_count += 1; if ((state->flags & CLEANUP_FLAG_FILTER) && (CHECK(MIME_HDR_PRIMARY, cleanup_header_checks, VAR_HEADER_CHECKS) || CHECK(MIME_HDR_MULTIPART, cleanup_mimehdr_checks, VAR_MIMEHDR_CHECKS) || CHECK(MIME_HDR_NESTED, cleanup_nesthdr_checks, VAR_NESTHDR_CHECKS))) { char *header = vstring_str(header_buf); const char *value; if ((value = maps_find(checks, header, 0)) != 0) { const char *result; if ((result = cleanup_act(state, CLEANUP_ACT_CTXT_HEADER, header, value, map_class)) == CLEANUP_ACT_DROP) { return; } else if (result != header) { vstring_strcpy(header_buf, result); hdr_opts = header_opts_find(result); myfree((void *) result); } } else if (checks->error) { msg_warn("%s: %s map lookup problem -- " "message not accepted, try again later", state->queue_id, checks->title); state->errs |= CLEANUP_STAT_WRITE; } } /* * If this is an "unknown" header, just copy it to the output without * even bothering to fold long lines. cleanup_out() will split long * headers that do not fit a REC_TYPE_NORM record. */ if (hdr_opts == 0) { cleanup_out_header(state, header_buf); return; } /* * Allow 8-bit type info to override 7-bit type info. XXX Should reuse * the effort that went into MIME header parsing. */ hdrval = vstring_str(header_buf) + strlen(hdr_opts->name) + 1; while (ISSPACE(*hdrval)) hdrval++; /* trimblanks(hdrval, 0)[0] = 0; */ if (var_auto_8bit_enc_hdr && hdr_opts->type == HDR_CONTENT_TRANSFER_ENCODING) { for (cmp = code_map; cmp->name != 0; cmp++) { if (strcasecmp(hdrval, cmp->name) == 0) { if (strcasecmp(cmp->encoding, MAIL_ATTR_ENC_8BIT) == 0) nvtable_update(state->attr, MAIL_ATTR_ENCODING, cmp->encoding); break; } } } /* * Copy attachment etc. header blocks without further inspection. */ if (header_class != MIME_HDR_PRIMARY) { cleanup_out_header(state, header_buf); return; } /* * Known header. Remember that we have seen at least one. Find out what * we should do with this header: delete, count, rewrite. Note that we * should examine headers even when they will be deleted from the output, * because the addresses in those headers might be needed elsewhere. * * XXX 2821: Return-path breakage. * * RFC 821 specifies: When the receiver-SMTP makes the "final delivery" of a * message it inserts at the beginning of the mail data a return path * line. The return path line preserves the information in the * from the MAIL command. Here, final delivery means the * message leaves the SMTP world. Normally, this would mean it has been * delivered to the destination user, but in some cases it may be further * processed and transmitted by another mail system. * * And that is what Postfix implements. Delivery agents prepend * Return-Path:. In order to avoid cluttering up the message with * possibly inconsistent Return-Path: information (the sender can change * as the result of mail forwarding or mailing list delivery), Postfix * removes any existing Return-Path: headers. * * RFC 2821 Section 4.4 specifies: A message-originating SMTP system * SHOULD NOT send a message that already contains a Return-path header. * SMTP servers performing a relay function MUST NOT inspect the message * data, and especially not to the extent needed to determine if * Return-path headers are present. SMTP servers making final delivery * MAY remove Return-path headers before adding their own. */ else { state->headers_seen |= (1 << hdr_opts->type); if (hdr_opts->type == HDR_MESSAGE_ID) msg_info("%s: message-id=%s", state->queue_id, hdrval); if (hdr_opts->type == HDR_RESENT_MESSAGE_ID) msg_info("%s: resent-message-id=%s", state->queue_id, hdrval); if (hdr_opts->type == HDR_RECEIVED) { if (state->hop_count >= var_hopcount_limit) { msg_warn("%s: message rejected: hopcount exceeded", state->queue_id); state->errs |= CLEANUP_STAT_HOPS; } /* Save our Received: header after maybe updating headers above. */ if (state->hop_count == 1) argv_add(state->auto_hdrs, vstring_str(header_buf), ARGV_END); } if (CLEANUP_OUT_OK(state)) { if (hdr_opts->flags & HDR_OPT_RR) state->resent = "Resent-"; if ((hdr_opts->flags & HDR_OPT_SENDER) && state->hdr_rewrite_context) { cleanup_rewrite_sender(state, hdr_opts, header_buf); } else if ((hdr_opts->flags & HDR_OPT_RECIP) && state->hdr_rewrite_context) { cleanup_rewrite_recip(state, hdr_opts, header_buf); } else if ((hdr_opts->flags & HDR_OPT_DROP) == 0) { cleanup_out_header(state, header_buf); } } } } /* cleanup_header_done_callback - insert missing message headers */ static void cleanup_header_done_callback(void *context) { const char *myname = "cleanup_header_done_callback"; CLEANUP_STATE *state = (CLEANUP_STATE *) context; char time_stamp[1024]; /* XXX locale dependent? */ struct tm *tp; TOK822 *token; TOK822 *dummy_token; time_t tv; /* * XXX Workaround: when we reach the end of headers, mime_state_update() * may execute up to three call-backs before returning to the caller: * head_out(), head_end(), and body_out() or body_end(). As long as * call-backs don't return a result, each call-back has to check for * itself if the previous call-back experienced a problem. */ if (CLEANUP_OUT_OK(state) == 0) return; /* * Future proofing: the Milter client's header suppression algorithm * assumes that the MTA prepends its own Received: header. This * assumption may be violated after some source-code update. The * following check ensures consistency, at least for local submission. */ if (state->hop_count < 1) { msg_warn("%s: message rejected: no Received: header", state->queue_id); state->errs |= CLEANUP_STAT_BAD; return; } /* * Add a missing (Resent-)Message-Id: header. The message ID gives the * time in GMT units, plus the local queue ID. * * XXX Message-Id is not a required message header (RFC 822 and RFC 2822). * * XXX It is the queue ID non-inode bits that prevent messages from getting * the same Message-Id within the same second. * * XXX An arbitrary amount of time may pass between the start of the mail * transaction and the creation of a queue file. Since we guarantee queue * ID uniqueness only within a second, we must ensure that the time in * the message ID matches the queue ID creation time, as long as we use * the queue ID in the message ID. * * XXX We log a dummy name=value record so that we (hopefully) don't break * compatibility with existing logfile analyzers, and so that we don't * complicate future code that wants to log more name=value attributes. */ if ((state->hdr_rewrite_context || var_always_add_hdrs) && (state->headers_seen & (1 << (state->resent[0] ? HDR_RESENT_MESSAGE_ID : HDR_MESSAGE_ID))) == 0) { if (var_long_queue_ids) { vstring_sprintf(state->temp1, "%s@%s", state->queue_id, var_myhostname); } else { tv = state->handle->ctime.tv_sec; tp = gmtime(&tv); strftime(time_stamp, sizeof(time_stamp), "%Y%m%d%H%M%S", tp); vstring_sprintf(state->temp1, "%s.%s@%s", time_stamp, state->queue_id, var_myhostname); } cleanup_out_format(state, REC_TYPE_NORM, "%sMessage-Id: <%s>", state->resent, vstring_str(state->temp1)); msg_info("%s: %smessage-id=<%s>", state->queue_id, *state->resent ? "resent-" : "", vstring_str(state->temp1)); state->headers_seen |= (1 << (state->resent[0] ? HDR_RESENT_MESSAGE_ID : HDR_MESSAGE_ID)); } if ((state->headers_seen & (1 << HDR_MESSAGE_ID)) == 0) msg_info("%s: message-id=<>", state->queue_id); /* * Add a missing (Resent-)Date: header. The date is in local time units, * with the GMT offset at the end. */ if ((state->hdr_rewrite_context || var_always_add_hdrs) && (state->headers_seen & (1 << (state->resent[0] ? HDR_RESENT_DATE : HDR_DATE))) == 0) { cleanup_out_format(state, REC_TYPE_NORM, "%sDate: %s", state->resent, mail_date(state->arrival_time.tv_sec)); } /* * Add a missing (Resent-)From: header. */ if ((state->hdr_rewrite_context || var_always_add_hdrs) && (state->headers_seen & (1 << (state->resent[0] ? HDR_RESENT_FROM : HDR_FROM))) == 0) { quote_822_local(state->temp1, *state->sender ? state->sender : MAIL_ADDR_MAIL_DAEMON); if (*state->sender && state->fullname && *state->fullname) { char *cp; /* Enforce some sanity on full name content. */ while ((cp = strchr(state->fullname, '\r')) != 0 || (cp = strchr(state->fullname, '\n')) != 0) *cp = ' '; /* * "From: phrase ". Quote the phrase if it contains * specials or the "%!" legacy address operators. */ if (cleanup_hfrom_format == HFROM_FORMAT_CODE_STD) { vstring_sprintf(state->temp2, "%sFrom: ", state->resent); if (state->fullname[strcspn(state->fullname, "%!" LEX_822_SPECIALS)] == 0) { /* Normalize whitespace. */ token = tok822_scan_limit(state->fullname, &dummy_token, var_token_limit); } else { token = tok822_alloc(TOK822_QSTRING, state->fullname); } if (token) { tok822_externalize(state->temp2, token, TOK822_STR_NONE); tok822_free(token); vstring_strcat(state->temp2, " "); } vstring_sprintf_append(state->temp2, "<%s>", vstring_str(state->temp1)); } /* * "From: addr-spec (ctext)". This is the obsolete form. */ else { vstring_sprintf(state->temp2, "%sFrom: %s ", state->resent, vstring_str(state->temp1)); vstring_sprintf(state->temp1, "(%s)", state->fullname); token = tok822_parse(vstring_str(state->temp1)); tok822_externalize(state->temp2, token, TOK822_STR_NONE); tok822_free_tree(token); } } /* * "From: addr-spec". This is the form in the absence of full name * information, also used for mail from mailer-daemon. */ else { vstring_sprintf(state->temp2, "%sFrom: %s", state->resent, vstring_str(state->temp1)); } CLEANUP_OUT_BUF(state, REC_TYPE_NORM, state->temp2); } /* * XXX 2821: Appendix B: The return address in the MAIL command SHOULD, * if possible, be derived from the system's identity for the submitting * (local) user, and the "From:" header field otherwise. If there is a * system identity available, it SHOULD also be copied to the Sender * header field if it is different from the address in the From header * field. (Any Sender field that was already there SHOULD be removed.) * Similar wording appears in RFC 2822 section 3.6.2. * * Postfix presently does not insert a Sender: header if envelope and From: * address differ. Older Postfix versions assumed that the envelope * sender address specifies the system identity and inserted Sender: * whenever envelope and From: differed. This was wrong with relayed * mail, and was often not even desirable with original submissions. * * XXX 2822 Section 3.6.2, as well as RFC 822 Section 4.1: FROM headers can * contain multiple addresses. If this is the case, then a Sender: header * must be provided with a single address. * * Postfix does not count the number of addresses in a From: header * (although doing so is trivial, once the address is parsed). */ /* * Add a missing destination header. */ #define VISIBLE_RCPT ((1 << HDR_TO) | (1 << HDR_RESENT_TO) \ | (1 << HDR_CC) | (1 << HDR_RESENT_CC)) if ((state->hdr_rewrite_context || var_always_add_hdrs) && (state->headers_seen & VISIBLE_RCPT) == 0 && *var_rcpt_witheld) { if (!is_header(var_rcpt_witheld)) { msg_warn("bad %s header text \"%s\" -- " "need \"headername: headervalue\"", VAR_RCPT_WITHELD, var_rcpt_witheld); } else { cleanup_out_format(state, REC_TYPE_NORM, "%s", var_rcpt_witheld); } } /* * Place a dummy PTR record right after the last header so that we can * append headers without having to worry about clobbering the * end-of-content marker. */ if (state->milters || cleanup_milters) { if ((state->append_hdr_pt_offset = vstream_ftell(state->dst)) < 0) msg_fatal("%s: vstream_ftell %s: %m", myname, cleanup_path); cleanup_out_format(state, REC_TYPE_PTR, REC_TYPE_PTR_FORMAT, 0L); if ((state->append_hdr_pt_target = vstream_ftell(state->dst)) < 0) msg_fatal("%s: vstream_ftell %s: %m", myname, cleanup_path); state->body_offset = state->append_hdr_pt_target; } } /* cleanup_body_callback - output one body record */ static void cleanup_body_callback(void *context, int type, const char *buf, ssize_t len, off_t offset) { CLEANUP_STATE *state = (CLEANUP_STATE *) context; /* * XXX Workaround: when we reach the end of headers, mime_state_update() * may execute up to three call-backs before returning to the caller: * head_out(), head_end(), and body_out() or body_end(). As long as * call-backs don't return a result, each call-back has to check for * itself if the previous call-back experienced a problem. */ if (CLEANUP_OUT_OK(state) == 0) return; /* * Crude message body content filter for emergencies. This code has * several problems: it sees one line at a time; it looks at long lines * only in chunks of line_length_limit (2048) characters; it is easily * bypassed with encodings and other tricks. */ if ((state->flags & CLEANUP_FLAG_FILTER) && cleanup_body_checks && (var_body_check_len == 0 || offset < var_body_check_len)) { const char *value; if ((value = maps_find(cleanup_body_checks, buf, 0)) != 0) { const char *result; if ((result = cleanup_act(state, CLEANUP_ACT_CTXT_BODY, buf, value, VAR_BODY_CHECKS)) == CLEANUP_ACT_DROP) { return; } else if (result != buf) { cleanup_out(state, type, result, strlen(result)); myfree((void *) result); return; } } else if (cleanup_body_checks->error) { msg_warn("%s: %s map lookup problem -- " "message not accepted, try again later", state->queue_id, cleanup_body_checks->title); state->errs |= CLEANUP_STAT_WRITE; } } cleanup_out(state, type, buf, len); } /* cleanup_message_headerbody - process message content, header and body */ static void cleanup_message_headerbody(CLEANUP_STATE *state, int type, const char *buf, ssize_t len) { const char *myname = "cleanup_message_headerbody"; const MIME_STATE_DETAIL *detail; const char *cp; char *dst; /* * Replace each stray CR or LF with one space. These are not allowed in * SMTP, and can be used to enable outbound (remote) SMTP smuggling. * Replacing these early ensures that our later DKIM etc. signature will * not be invalidated. Besides preventing SMTP smuggling, replacing stray * or ensures that the result of signature validation by a * later mail system will not depend on how that mail system handles * those stray characters in an implementation-dependent manner. * * The input length is not changed, therefore it is safe to overwrite the * input. */ if (var_cleanup_mask_stray_cr_lf) for (dst = (char *) buf; dst < buf + len; dst++) if (*dst == '\r' || *dst == '\n') *dst = ' '; /* * Reject unwanted characters. * * XXX Possible optimization: simplify the loop when the "reject" set * contains only one character. */ if ((state->flags & CLEANUP_FLAG_FILTER) && cleanup_reject_chars) { for (cp = buf; cp < buf + len; cp++) { if (memchr(vstring_str(cleanup_reject_chars), *(const unsigned char *) cp, VSTRING_LEN(cleanup_reject_chars))) { cleanup_act(state, CLEANUP_ACT_CTXT_ANY, buf, "REJECT disallowed character", "character reject"); return; } } } /* * Strip unwanted characters. Don't overwrite the input. * * XXX Possible space+time optimization: use a bitset. * * XXX Possible optimization: simplify the loop when the "strip" set * contains only one character. * * XXX Possible optimization: copy the input only if we really have to. */ if ((state->flags & CLEANUP_FLAG_FILTER) && cleanup_strip_chars) { VSTRING_RESET(state->stripped_buf); VSTRING_SPACE(state->stripped_buf, len + 1); dst = vstring_str(state->stripped_buf); for (cp = buf; cp < buf + len; cp++) if (!memchr(vstring_str(cleanup_strip_chars), *(const unsigned char *) cp, VSTRING_LEN(cleanup_strip_chars))) *dst++ = *cp; *dst = 0; buf = vstring_str(state->stripped_buf); len = dst - buf; } /* * Copy text record to the output. */ if (type == REC_TYPE_NORM || type == REC_TYPE_CONT) { state->mime_errs = mime_state_update(state->mime_state, type, buf, len); } /* * If we have reached the end of the message content segment, record the * current file position so we can compute the message size lateron. */ else if (type == REC_TYPE_XTRA) { state->mime_errs = mime_state_update(state->mime_state, type, buf, len); if (state->milters || cleanup_milters) /* Make room for body modification. */ cleanup_out_format(state, REC_TYPE_PTR, REC_TYPE_PTR_FORMAT, 0L); /* Ignore header truncation after primary message headers. */ state->mime_errs &= ~MIME_ERR_TRUNC_HEADER; if (state->mime_errs && state->reason == 0) { state->errs |= CLEANUP_STAT_CONT; detail = mime_state_detail(state->mime_errs); state->reason = dsn_prepend(detail->dsn, detail->text); } state->mime_state = mime_state_free(state->mime_state); if ((state->xtra_offset = vstream_ftell(state->dst)) < 0) msg_fatal("%s: vstream_ftell %s: %m", myname, cleanup_path); state->cont_length = state->xtra_offset - state->data_offset; state->action = cleanup_extracted; } /* * This should never happen. */ else { msg_warn("%s: message rejected: " "unexpected record type %d in message content", myname, type); state->errs |= CLEANUP_STAT_BAD; } } /* cleanup_mime_error_callback - error report call-back routine */ static void cleanup_mime_error_callback(void *context, int err_code, const char *text, ssize_t len) { CLEANUP_STATE *state = (CLEANUP_STATE *) context; const char *origin; /* * Message header too large errors are handled after the end of the * primary message headers. */ if ((err_code & ~MIME_ERR_TRUNC_HEADER) != 0) { if ((origin = nvtable_find(state->attr, MAIL_ATTR_LOG_ORIGIN)) == 0) origin = MAIL_ATTR_ORG_NONE; #define TEXT_LEN (len < 100 ? (int) len : 100) msg_info("%s: reject: mime-error %s: %.*s from %s; from=<%s> to=<%s>", state->queue_id, mime_state_error(err_code), TEXT_LEN, text, origin, info_log_addr_form_sender(state->sender), info_log_addr_form_recipient(state->recip ? state->recip : "unknown")); } } /* cleanup_message - initialize message content segment */ void cleanup_message(CLEANUP_STATE *state, int type, const char *buf, ssize_t len) { const char *myname = "cleanup_message"; int mime_options; /* * Write the start-of-content segment marker. */ cleanup_out_string(state, REC_TYPE_MESG, ""); if ((state->data_offset = vstream_ftell(state->dst)) < 0) msg_fatal("%s: vstream_ftell %s: %m", myname, cleanup_path); /* * Set up MIME processing options, if any. MIME_OPT_DISABLE_MIME disables * special processing of Content-Type: headers, and thus, causes all text * after the primary headers to be treated as the message body. */ mime_options = 0; if (var_disable_mime_input) { mime_options |= MIME_OPT_DISABLE_MIME; } else { /* Turn off content checks if bouncing or forwarding mail. */ if (state->flags & CLEANUP_FLAG_FILTER) { if (var_strict_8bitmime || var_strict_7bit_hdrs) mime_options |= MIME_OPT_REPORT_8BIT_IN_HEADER; if (var_strict_8bitmime || var_strict_8bit_body) mime_options |= MIME_OPT_REPORT_8BIT_IN_7BIT_BODY; if (var_strict_encoding) mime_options |= MIME_OPT_REPORT_ENCODING_DOMAIN; if (var_strict_8bitmime || var_strict_7bit_hdrs || var_strict_8bit_body || var_strict_encoding || *var_header_checks || *var_mimehdr_checks || *var_nesthdr_checks) mime_options |= MIME_OPT_REPORT_NESTING; } } state->mime_state = mime_state_alloc(mime_options, cleanup_header_callback, cleanup_header_done_callback, cleanup_body_callback, (MIME_STATE_ANY_END) 0, cleanup_mime_error_callback, (void *) state); /* * XXX Workaround: truncate a long message header so that we don't exceed * the default Sendmail libmilter request size limit of 65535. */ #define KLUDGE_HEADER_LIMIT 60000 if ((cleanup_milters || state->milters) && var_header_limit > KLUDGE_HEADER_LIMIT) var_header_limit = KLUDGE_HEADER_LIMIT; /* * Pass control to the header processing routine. */ state->action = cleanup_message_headerbody; cleanup_message_headerbody(state, type, buf, len); }