+++ /dev/null
-// This module is an SMTP and ESMTP server for the Citadel system.
-// It is compliant with all of the following:
-//
-// RFC 821 - Simple Mail Transfer Protocol
-// RFC 876 - Survey of SMTP Implementations
-// RFC 1047 - Duplicate messages and SMTP
-// RFC 1652 - 8 bit MIME
-// RFC 1869 - Extended Simple Mail Transfer Protocol
-// RFC 1870 - SMTP Service Extension for Message Size Declaration
-// RFC 2033 - Local Mail Transfer Protocol
-// RFC 2197 - SMTP Service Extension for Command Pipelining
-// RFC 2476 - Message Submission
-// RFC 2487 - SMTP Service Extension for Secure SMTP over TLS
-// RFC 2554 - SMTP Service Extension for Authentication
-// RFC 2821 - Simple Mail Transfer Protocol
-// RFC 2822 - Internet Message Format
-// RFC 2920 - SMTP Service Extension for Command Pipelining
-//
-// The VRFY and EXPN commands have been removed from this implementation
-// because nobody uses these commands anymore, except for spammers.
-//
-// Copyright (c) 1998-2022 by the citadel.org team
-//
-// This program is open source software; you can redistribute it and/or modify
-// it under the terms of the GNU General Public License version 3.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-// GNU General Public License for more details.
-
-#include "sysdep.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdio.h>
-#include <termios.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <pwd.h>
-#include <errno.h>
-#include <sys/types.h>
-#include <syslog.h>
-#include <time.h>
-#include <sys/wait.h>
-#include <ctype.h>
-#include <string.h>
-#include <limits.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <arpa/inet.h>
-#include <libcitadel.h>
-#include "citadel.h"
-#include "server.h"
-#include "citserver.h"
-#include "support.h"
-#include "config.h"
-#include "control.h"
-#include "user_ops.h"
-#include "room_ops.h"
-#include "database.h"
-#include "msgbase.h"
-#include "internet_addressing.h"
-#include "genstamp.h"
-#include "domain.h"
-#include "clientsocket.h"
-#include "locate_host.h"
-#include "citadel_dirs.h"
-#include "ctdl_module.h"
-
-#include "smtp_util.h"
-
-enum { // Command states for login authentication
- smtp_command,
- smtp_user,
- smtp_password,
- smtp_plain
-};
-
-enum SMTP_FLAGS {
- HELO,
- EHLO,
- LHLO
-};
-
-
-// Here's where our SMTP session begins its happy day.
-void smtp_greeting(int is_msa) {
- char message_to_spammer[1024];
-
- strcpy(CC->cs_clientname, "SMTP session");
- CC->internal_pgm = 1;
- CC->cs_flags |= CS_STEALTH;
- CC->session_specific_data = malloc(sizeof(struct citsmtp));
- memset(SMTP, 0, sizeof(struct citsmtp));
- SMTP->is_msa = is_msa;
- SMTP->Cmd = NewStrBufPlain(NULL, SIZ);
- SMTP->helo_node = NewStrBuf();
- SMTP->from = NewStrBufPlain(NULL, SIZ);
- SMTP->recipients = NewStrBufPlain(NULL, SIZ);
- SMTP->OneRcpt = NewStrBufPlain(NULL, SIZ);
- SMTP->preferred_sender_email = NULL;
- SMTP->preferred_sender_name = NULL;
-
- // If this config option is set, reject connections from problem
- // addresses immediately instead of after they execute a RCPT
- if ( (CtdlGetConfigInt("c_rbl_at_greeting")) && (SMTP->is_msa == 0) ) {
- if (rbl_check(CC->cs_addr, message_to_spammer)) {
- if (server_shutting_down)
- cprintf("421 %s\r\n", message_to_spammer);
- else
- cprintf("550 %s\r\n", message_to_spammer);
- CC->kill_me = KILLME_SPAMMER;
- /* no need to free_recipients(valid), it's not allocated yet */
- return;
- }
- }
-
- // Otherwise we're either clean or we check later.
-
- if (CC->nologin==1) {
- cprintf("451 Too many connections are already open; please try again later.\r\n");
- CC->kill_me = KILLME_MAX_SESSIONS_EXCEEDED;
- // no need to free_recipients(valid), it's not allocated yet
- return;
- }
-
- // Note: the FQDN *must* appear as the first thing after the 220 code.
- // Some clients (including citmail.c) depend on it being there.
- cprintf("220 %s ESMTP Citadel server ready.\r\n", CtdlGetConfigStr("c_fqdn"));
-}
-
-
-// SMTPS is just like SMTP, except it goes crypto right away.
-void smtps_greeting(void) {
- CtdlModuleStartCryptoMsgs(NULL, NULL, NULL);
-#ifdef HAVE_OPENSSL
- if (!CC->redirect_ssl) CC->kill_me = KILLME_NO_CRYPTO; // kill session if no crypto
-#endif
- smtp_greeting(0);
-}
-
-
-// SMTP MSA port requires authentication.
-void smtp_msa_greeting(void) {
- smtp_greeting(1);
-}
-
-
-// LMTP is like SMTP but with some extra bonus footage added.
-void lmtp_greeting(void) {
-
- smtp_greeting(0);
- SMTP->is_lmtp = 1;
-}
-
-
-// Generic SMTP MTA greeting
-void smtp_mta_greeting(void) {
- smtp_greeting(0);
-}
-
-
-// We also have an unfiltered LMTP socket that bypasses spam filters.
-void lmtp_unfiltered_greeting(void) {
- smtp_greeting(0);
- SMTP->is_lmtp = 1;
- SMTP->is_unfiltered = 1;
-}
-
-
-// Login greeting common to all auth methods
-void smtp_auth_greeting(void) {
- cprintf("235 Hello, %s\r\n", CC->user.fullname);
- syslog(LOG_INFO, "serv_smtp: SMTP authenticated %s", CC->user.fullname);
- CC->internal_pgm = 0;
- CC->cs_flags &= ~CS_STEALTH;
-}
-
-
-// Implement HELO and EHLO commands.
-// which_command: 0=HELO, 1=EHLO, 2=LHLO
-void smtp_hello(int which_command) {
-
- if (StrLength(SMTP->Cmd) >= 6) {
- FlushStrBuf(SMTP->helo_node);
- StrBufAppendBuf(SMTP->helo_node, SMTP->Cmd, 5);
- }
-
- if ( (which_command != LHLO) && (SMTP->is_lmtp) ) {
- cprintf("500 Only LHLO is allowed when running LMTP\r\n");
- return;
- }
-
- if ( (which_command == LHLO) && (SMTP->is_lmtp == 0) ) {
- cprintf("500 LHLO is only allowed when running LMTP\r\n");
- return;
- }
-
- if (which_command == HELO) {
- cprintf("250 Hello %s (%s [%s])\r\n",
- ChrPtr(SMTP->helo_node),
- CC->cs_host,
- CC->cs_addr
- );
- }
- else {
- if (which_command == EHLO) {
- cprintf("250-Hello %s (%s [%s])\r\n",
- ChrPtr(SMTP->helo_node),
- CC->cs_host,
- CC->cs_addr
- );
- }
- else {
- cprintf("250-Greetings and joyous salutations.\r\n");
- }
- cprintf("250-HELP\r\n");
- cprintf("250-SIZE %ld\r\n", CtdlGetConfigLong("c_maxmsglen"));
-
-#ifdef HAVE_OPENSSL
- // Offer TLS, but only if TLS is not already active.
- // Furthermore, only offer TLS when running on
- // the SMTP-MSA port, not on the SMTP-MTA port, due to
- // questionable reliability of TLS in certain sending MTA's.
- if ( (!CC->redirect_ssl) && (SMTP->is_msa) ) {
- cprintf("250-STARTTLS\r\n");
- }
-#endif
-
- cprintf("250-AUTH LOGIN PLAIN\r\n"
- "250-AUTH=LOGIN PLAIN\r\n"
- "250 8BITMIME\r\n"
- );
- }
-}
-
-
-// Backend function for smtp_webcit_preferences_hack().
-// Look at a message and determine if it's the preferences file.
-void smtp_webcit_preferences_hack_backend(long msgnum, void *userdata) {
- struct CtdlMessage *msg;
- char **webcit_conf = (char **) userdata;
-
- if (*webcit_conf) {
- return; // already got it
- }
-
- msg = CtdlFetchMessage(msgnum, 1);
- if (msg == NULL) {
- return;
- }
-
- if ( !CM_IsEmpty(msg, eMsgSubject) && (!strcasecmp(msg->cm_fields[eMsgSubject], "__ WebCit Preferences __"))) {
- // This is it! Change ownership of the message text so it doesn't get freed.
- *webcit_conf = (char *)msg->cm_fields[eMesageText];
- msg->cm_fields[eMesageText] = NULL;
- }
- CM_Free(msg);
-}
-
-
-// The configuration item for the user's preferred display name for outgoing email is, unfortunately,
-// stored in the account's WebCit configuration. We have to fetch it now.
-void smtp_webcit_preferences_hack(void) {
- char config_roomname[ROOMNAMELEN];
- char *webcit_conf = NULL;
-
- snprintf(config_roomname, sizeof config_roomname, "%010ld.%s", CC->user.usernum, USERCONFIGROOM);
- if (CtdlGetRoom(&CC->room, config_roomname) != 0) {
- return;
- }
-
- // Find the WebCit configuration message
- CtdlForEachMessage(MSGS_ALL, 1, NULL, NULL, NULL, smtp_webcit_preferences_hack_backend, (void *)&webcit_conf);
-
- if (!webcit_conf) {
- return;
- }
-
- // Parse the webcit configuration and attempt to do something useful with it
- char *str = webcit_conf;
- char *saveptr = str;
- char *this_line = NULL;
- while (this_line = strtok_r(str, "\n", &saveptr), this_line != NULL) {
- str = NULL;
- if (!strncasecmp(this_line, "defaultfrom|", 12)) {
- SMTP->preferred_sender_email = NewStrBufPlain(&this_line[12], -1);
- }
- if (!strncasecmp(this_line, "defaultname|", 12)) {
- SMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
- }
- if ((!strncasecmp(this_line, "defaultname|", 12)) && (SMTP->preferred_sender_name == NULL)) {
- SMTP->preferred_sender_name = NewStrBufPlain(&this_line[12], -1);
- }
-
- }
- free(webcit_conf);
-}
-
-
-// Implement HELP command.
-void smtp_help(void) {
- cprintf("214 RTFM http://www.ietf.org/rfc/rfc2821.txt\r\n");
-}
-
-
-void smtp_get_user(int offset) {
- char buf[SIZ];
-
- StrBuf *UserName = NewStrBufDup(SMTP->Cmd);
- StrBufCutLeft(UserName, offset);
- StrBufDecodeBase64(UserName);
-
- if (CtdlLoginExistingUser(ChrPtr(UserName)) == login_ok) {
- size_t len = CtdlEncodeBase64(buf, "Password:", 9, 0);
-
- if (buf[len - 1] == '\n') {
- buf[len - 1] = '\0';
- }
- cprintf("334 %s\r\n", buf);
- SMTP->command_state = smtp_password;
- }
- else {
- cprintf("500 No such user.\r\n");
- SMTP->command_state = smtp_command;
- }
- FreeStrBuf(&UserName);
-}
-
-
-void smtp_get_pass(void) {
- char password[SIZ];
-
- memset(password, 0, sizeof(password));
- StrBufDecodeBase64(SMTP->Cmd);
- syslog(LOG_DEBUG, "serv_smtp: trying <%s>", password);
- if (CtdlTryPassword(SKEY(SMTP->Cmd)) == pass_ok) {
- smtp_auth_greeting();
- }
- else {
- cprintf("535 Authentication failed.\r\n");
- }
- SMTP->command_state = smtp_command;
-}
-
-
-// Back end for PLAIN auth method (either inline or multistate)
-void smtp_try_plain(void) {
- const char*decoded_authstring;
- char ident[256] = "";
- char user[256] = "";
- char pass[256] = "";
- int result;
-
- long decoded_len;
- long len = 0;
- long plen = 0;
-
- memset(pass, 0, sizeof(pass));
- decoded_len = StrBufDecodeBase64(SMTP->Cmd);
-
- if (decoded_len > 0) {
- decoded_authstring = ChrPtr(SMTP->Cmd);
-
- len = safestrncpy(ident, decoded_authstring, sizeof ident);
-
- decoded_len -= len - 1;
- decoded_authstring += len + 1;
-
- if (decoded_len > 0) {
- len = safestrncpy(user, decoded_authstring, sizeof user);
-
- decoded_authstring += len + 1;
- decoded_len -= len - 1;
- }
-
- if (decoded_len > 0) {
- plen = safestrncpy(pass, decoded_authstring, sizeof pass);
-
- if (plen < 0)
- plen = sizeof(pass) - 1;
- }
- }
-
- SMTP->command_state = smtp_command;
-
- if (!IsEmptyStr(ident)) {
- result = CtdlLoginExistingUser(ident);
- }
- else {
- result = CtdlLoginExistingUser(user);
- }
-
- if (result == login_ok) {
- if (CtdlTryPassword(pass, plen) == pass_ok) {
- smtp_webcit_preferences_hack();
- smtp_auth_greeting();
- return;
- }
- }
- cprintf("504 Authentication failed.\r\n");
-}
-
-
-// Attempt to perform authenticated SMTP
-void smtp_auth(void) {
- char username_prompt[64];
- char method[64];
- char encoded_authstring[1024];
-
- if (CC->logged_in) {
- cprintf("504 Already logged in.\r\n");
- return;
- }
-
- if (StrLength(SMTP->Cmd) < 6) {
- cprintf("501 Syntax error\r\n");
- return;
- }
-
- extract_token(method, ChrPtr(SMTP->Cmd) + 5, 0, ' ', sizeof method);
-
- if (!strncasecmp(method, "login", 5) ) {
- if (StrLength(SMTP->Cmd) >= 12) {
- syslog(LOG_DEBUG, "serv_smtp: username <%s> supplied inline", ChrPtr(SMTP->Cmd)+11);
- smtp_get_user(11);
- }
- else {
- size_t len = CtdlEncodeBase64(username_prompt, "Username:", 9, 0);
- if (username_prompt[len - 1] == '\n') {
- username_prompt[len - 1] = '\0';
- }
- cprintf("334 %s\r\n", username_prompt);
- SMTP->command_state = smtp_user;
- }
- return;
- }
-
- if (!strncasecmp(method, "plain", 5) ) {
- long len;
- if (num_tokens(ChrPtr(SMTP->Cmd) + 5, ' ') < 2) {
- cprintf("334 \r\n");
- SMTP->command_state = smtp_plain;
- return;
- }
-
- len = extract_token(encoded_authstring,
- ChrPtr(SMTP->Cmd) + 5,
- 1, ' ',
- sizeof encoded_authstring);
- StrBufPlain(SMTP->Cmd, encoded_authstring, len);
- smtp_try_plain();
- return;
- }
-
- cprintf("504 Unknown authentication method.\r\n");
- return;
-}
-
-
-// Implements the RSET (reset state) command.
-// Currently this just zeroes out the state buffer. If pointers to data
-// allocated with malloc() are ever placed in the state buffer, we have to
-// be sure to free() them first!
-//
-// Set do_response to nonzero to output the SMTP RSET response code.
-void smtp_rset(int do_response) {
- FlushStrBuf(SMTP->Cmd);
- FlushStrBuf(SMTP->helo_node);
- FlushStrBuf(SMTP->from);
- FlushStrBuf(SMTP->recipients);
- FlushStrBuf(SMTP->OneRcpt);
-
- SMTP->command_state = 0;
- SMTP->number_of_recipients = 0;
- SMTP->delivery_mode = 0;
- SMTP->message_originated_locally = 0;
- SMTP->is_msa = 0;
- // is_lmtp and is_unfiltered should not be cleared.
-
- if (do_response) {
- cprintf("250 Zap!\r\n");
- }
-}
-
-
-// Clear out the portions of the state buffer that need to be cleared out
-// after the DATA command finishes.
-void smtp_data_clear(void) {
- FlushStrBuf(SMTP->from);
- FlushStrBuf(SMTP->recipients);
- FlushStrBuf(SMTP->OneRcpt);
- SMTP->number_of_recipients = 0;
- SMTP->delivery_mode = 0;
- SMTP->message_originated_locally = 0;
-}
-
-
-// Implements the "MAIL FROM:" command
-void smtp_mail(void) {
- char user[SIZ];
- char node[SIZ];
- char name[SIZ];
-
- if (StrLength(SMTP->from) > 0) {
- cprintf("503 Only one sender permitted\r\n");
- return;
- }
-
- if (StrLength(SMTP->Cmd) < 6) {
- cprintf("501 Syntax error\r\n");
- return;
- }
-
- if (strncasecmp(ChrPtr(SMTP->Cmd) + 5, "From:", 5)) {
- cprintf("501 Syntax error\r\n");
- return;
- }
-
- StrBufAppendBuf(SMTP->from, SMTP->Cmd, 5);
- StrBufTrim(SMTP->from);
- if (strchr(ChrPtr(SMTP->from), '<') != NULL) {
- StrBufStripAllBut(SMTP->from, '<', '>');
- }
-
- // We used to reject empty sender names, until it was brought to our
- // attention that RFC1123 5.2.9 requires that this be allowed. So now
- // we allow it, but replace the empty string with a fake
- // address so we don't have to contend with the empty string causing
- // other code to fail when it's expecting something there.
- if (StrLength(SMTP->from) == 0) {
- StrBufPlain(SMTP->from, HKEY("someone@example.com"));
- }
-
- // If this SMTP connection is from a logged-in user, force the 'from'
- // to be the user's Internet e-mail address as Citadel knows it.
- if (CC->logged_in) {
- StrBufPlain(SMTP->from, CC->cs_inet_email, -1);
- cprintf("250 Sender ok <%s>\r\n", ChrPtr(SMTP->from));
- SMTP->message_originated_locally = 1;
- return;
- }
-
- else if (SMTP->is_lmtp) {
- // Bypass forgery checking for LMTP
- }
-
- // Otherwise, make sure outsiders aren't trying to forge mail from
- // this system (unless, of course, c_allow_spoofing is enabled)
- else if (CtdlGetConfigInt("c_allow_spoofing") == 0) {
- process_rfc822_addr(ChrPtr(SMTP->from), user, node, name);
- syslog(LOG_DEBUG, "serv_smtp: claimed envelope sender is '%s' == '%s' @ '%s' ('%s')",
- ChrPtr(SMTP->from), user, node, name
- );
- if (CtdlHostAlias(node) != hostalias_nomatch) {
- cprintf("550 You must log in to send mail from %s\r\n", node);
- FlushStrBuf(SMTP->from);
- syslog(LOG_DEBUG, "serv_smtp: rejecting unauthenticated mail from %s", node);
- return;
- }
- }
-
- cprintf("250 Sender ok\r\n");
-}
-
-
-// Implements the "RCPT To:" command
-void smtp_rcpt(void) {
- char message_to_spammer[SIZ];
- struct recptypes *valid = NULL;
-
- if (StrLength(SMTP->from) == 0) {
- cprintf("503 Need MAIL before RCPT\r\n");
- return;
- }
-
- if (StrLength(SMTP->Cmd) < 6) {
- cprintf("501 Syntax error\r\n");
- return;
- }
-
- if (strncasecmp(ChrPtr(SMTP->Cmd) + 5, "To:", 3)) {
- cprintf("501 Syntax error\r\n");
- return;
- }
-
- if ( (SMTP->is_msa) && (!CC->logged_in) ) {
- cprintf("550 You must log in to send mail on this port.\r\n");
- FlushStrBuf(SMTP->from);
- return;
- }
-
- FlushStrBuf(SMTP->OneRcpt);
- StrBufAppendBuf(SMTP->OneRcpt, SMTP->Cmd, 8);
- StrBufTrim(SMTP->OneRcpt);
- StrBufStripAllBut(SMTP->OneRcpt, '<', '>');
-
- if ( (StrLength(SMTP->OneRcpt) + StrLength(SMTP->recipients)) >= SIZ) {
- cprintf("452 Too many recipients\r\n");
- return;
- }
-
- // RBL check
- if (
- (!CC->logged_in) // Don't RBL authenticated users
- && (!SMTP->is_lmtp) // Don't RBL LMTP clients
- && (CtdlGetConfigInt("c_rbl_at_greeting") == 0) // Don't RBL if we did it at connection time
- && (rbl_check(CC->cs_addr, message_to_spammer))
- ) {
- cprintf("550 %s\r\n", message_to_spammer);
- return; // no need to free_recipients(valid)
- } // because it hasn't been allocated yet
-
- // This is a *preliminary* call to validate_recipients() to evaluate one recipient.
- valid = validate_recipients(
- (char *)ChrPtr(SMTP->OneRcpt),
- smtp_get_Recipients(),
- (SMTP->is_lmtp)? POST_LMTP: (CC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
- );
-
- // Any type of error thrown by validate_recipients() will make the SMTP transaction fail at this point.
- if (valid->num_error != 0) {
- cprintf("550 %s\r\n", valid->errormsg);
- free_recipients(valid);
- return;
- }
-
- if (
- (valid->num_internet > 0) // If it's outbound Internet mail...
- && (CC->logged_in) // ...and we're a logged-in user...
- && (CtdlCheckInternetMailPermission(&CC->user)==0) // ...who does not have Internet mail rights...
- ) {
- cprintf("551 <%s> - you do not have permission to send Internet mail\r\n", ChrPtr(SMTP->OneRcpt));
- free_recipients(valid);
- return;
- }
-
- if (
- (valid->num_internet > 0) // If it's outbound Internet mail...
- && (SMTP->message_originated_locally == 0) // ...and also inbound Internet mail...
- && (SMTP->is_lmtp == 0) /// ...and didn't arrive via LMTP...
- ) {
- cprintf("551 <%s> - relaying denied\r\n", ChrPtr(SMTP->OneRcpt));
- free_recipients(valid);
- return;
- }
-
- if (
- (valid->num_room > 0) // If it's mail to a room (mailing list)...
- && (SMTP->message_originated_locally == 0) // ...and also inbound Internet mail...
- && (is_email_subscribed_to_list((char *)ChrPtr(SMTP->from), valid->recp_room) == 0) // ...and not a subscriber
- ) {
- cprintf("551 <%s> - The message is not from a list member\r\n", ChrPtr(SMTP->OneRcpt));
- free_recipients(valid);
- return;
- }
-
- cprintf("250 RCPT ok <%s>\r\n", ChrPtr(SMTP->OneRcpt));
- if (StrLength(SMTP->recipients) > 0) {
- StrBufAppendBufPlain(SMTP->recipients, HKEY(","), 0);
- }
- StrBufAppendBuf(SMTP->recipients, SMTP->OneRcpt, 0);
- SMTP->number_of_recipients ++;
- if (valid != NULL) {
- free_recipients(valid);
- }
-}
-
-
-// Implements the DATA command
-void smtp_data(void) {
- StrBuf *body;
- StrBuf *defbody;
- struct CtdlMessage *msg = NULL;
- long msgnum = (-1L);
- char nowstamp[SIZ];
- struct recptypes *valid;
- int scan_errors;
- int i;
-
- if (StrLength(SMTP->from) == 0) {
- cprintf("503 Need MAIL command first.\r\n");
- return;
- }
-
- if (SMTP->number_of_recipients < 1) {
- cprintf("503 Need RCPT command first.\r\n");
- return;
- }
-
- cprintf("354 Transmit message now - terminate with '.' by itself\r\n");
-
- datestring(nowstamp, sizeof nowstamp, time(NULL), DATESTRING_RFC822);
- defbody = NewStrBufPlain(NULL, SIZ);
-
- if (defbody != NULL) {
- if (SMTP->is_lmtp && (CC->cs_UDSclientUID != -1)) {
- StrBufPrintf(
- defbody,
- "Received: from %s (Citadel from userid %ld)\n"
- " by %s; %s\n",
- ChrPtr(SMTP->helo_node),
- (long int) CC->cs_UDSclientUID,
- CtdlGetConfigStr("c_fqdn"),
- nowstamp);
- }
- else {
- StrBufPrintf(
- defbody,
- "Received: from %s (%s [%s])\n"
- " by %s; %s\n",
- ChrPtr(SMTP->helo_node),
- CC->cs_host,
- CC->cs_addr,
- CtdlGetConfigStr("c_fqdn"),
- nowstamp);
- }
- }
- body = CtdlReadMessageBodyBuf(HKEY("."), CtdlGetConfigLong("c_maxmsglen"), defbody, 1);
- FreeStrBuf(&defbody);
- if (body == NULL) {
- cprintf("550 Unable to save message: internal error.\r\n");
- return;
- }
-
- syslog(LOG_DEBUG, "serv_smtp: converting message...");
- msg = convert_internet_message_buf(&body);
-
- // If the user is locally authenticated, FORCE the From: header to
- // show up as the real sender. Yes, this violates the RFC standard,
- // but IT MAKES SENSE. If you prefer strict RFC adherence over
- // common sense, you can disable this in the configuration.
- //
- // We also set the "message room name" ('O' field) to MAILROOM
- // (which is Mail> on most systems) to prevent it from getting set
- // to something ugly like "0000058008.Sent Items>" when the message
- // is read with a Citadel client.
-
- if ( (CC->logged_in) && (CtdlGetConfigInt("c_rfc822_strict_from") != CFG_SMTP_FROM_NOFILTER) ) {
- int validemail = 0;
-
- if (!CM_IsEmpty(msg, erFc822Addr) &&
- ((CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_CORRECT) ||
- (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT) ) )
- {
- if (!IsEmptyStr(CC->cs_inet_email))
- validemail = strcmp(CC->cs_inet_email, msg->cm_fields[erFc822Addr]) == 0;
- if ((!validemail) &&
- (!IsEmptyStr(CC->cs_inet_other_emails)))
- {
- int num_secondary_emails = 0;
- int i;
- num_secondary_emails = num_tokens(CC->cs_inet_other_emails, '|');
- for (i=0; i < num_secondary_emails && !validemail; ++i) {
- char buf[256];
- extract_token(buf, CC->cs_inet_other_emails,i,'|',sizeof CC->cs_inet_other_emails);
- validemail = strcmp(buf, msg->cm_fields[erFc822Addr]) == 0;
- }
- }
- }
-
- if (!validemail && (CtdlGetConfigInt("c_rfc822_strict_from") == CFG_SMTP_FROM_REJECT)) {
- syslog(LOG_ERR, "serv_smtp: invalid sender '%s' - rejecting this message", msg->cm_fields[erFc822Addr]);
- cprintf("550 Invalid sender '%s' - rejecting this message.\r\n", msg->cm_fields[erFc822Addr]);
- return;
- }
-
- CM_SetField(msg, eOriginalRoom, HKEY(MAILROOM));
- if (SMTP->preferred_sender_name != NULL)
- CM_SetField(msg, eAuthor, SKEY(SMTP->preferred_sender_name));
- else
- CM_SetField(msg, eAuthor, CC->user.fullname, strlen(CC->user.fullname));
-
- if (!validemail) {
- if (SMTP->preferred_sender_email != NULL) {
- CM_SetField(msg, erFc822Addr, SKEY(SMTP->preferred_sender_email));
- }
- else {
- CM_SetField(msg, erFc822Addr, CC->cs_inet_email, strlen(CC->cs_inet_email));
- }
- }
- }
-
- // Set the "envelope from" address
- CM_SetField(msg, eMessagePath, SKEY(SMTP->from));
-
- // Set the "envelope to" address
- CM_SetField(msg, eenVelopeTo, SKEY(SMTP->recipients));
-
- // Submit the message into the Citadel system.
- valid = validate_recipients(
- (char *)ChrPtr(SMTP->recipients),
- smtp_get_Recipients(),
- (SMTP->is_lmtp)? POST_LMTP: (CC->logged_in)? POST_LOGGED_IN: POST_EXTERNAL
- );
-
- // If there are modules that want to scan this message before final
- // submission (such as virus checkers or spam filters), call them now
- // and give them an opportunity to reject the message.
- if (SMTP->is_unfiltered) {
- scan_errors = 0;
- }
- else {
- scan_errors = PerformMessageHooks(msg, valid, EVT_SMTPSCAN);
- }
-
- if (scan_errors > 0) { // We don't want this message!
-
- if (CM_IsEmpty(msg, eErrorMsg)) {
- CM_SetField(msg, eErrorMsg, HKEY("Message rejected by filter"));
- }
-
- StrBufPrintf(SMTP->OneRcpt, "550 %s\r\n", msg->cm_fields[eErrorMsg]);
- }
-
- else { // Ok, we'll accept this message.
- msgnum = CtdlSubmitMsg(msg, valid, "");
- if (msgnum > 0L) {
- StrBufPrintf(SMTP->OneRcpt, "250 Message accepted.\r\n");
- }
- else {
- StrBufPrintf(SMTP->OneRcpt, "550 Internal delivery error\r\n");
- }
- }
-
- // For SMTP and ESMTP, just print the result message. For LMTP, we
- // have to print one result message for each recipient. Since there
- // is nothing in Citadel which would cause different recipients to
- // have different results, we can get away with just spitting out the
- // same message once for each recipient.
- if (SMTP->is_lmtp) {
- for (i=0; i<SMTP->number_of_recipients; ++i) {
- cputbuf(SMTP->OneRcpt);
- }
- }
- else {
- cputbuf(SMTP->OneRcpt);
- }
-
- // Write something to the syslog(which may or may not be where the
- // rest of the Citadel logs are going; some sysadmins want LOG_MAIL).
- syslog((LOG_MAIL | LOG_INFO),
- "%ld: from=<%s>, nrcpts=%d, relay=%s [%s], stat=%s",
- msgnum,
- ChrPtr(SMTP->from),
- SMTP->number_of_recipients,
- CC->cs_host,
- CC->cs_addr,
- ChrPtr(SMTP->OneRcpt)
- );
-
- // Clean up
- CM_Free(msg);
- free_recipients(valid);
- smtp_data_clear(); // clear out the buffers now
-}
-
-
-// Implements the STARTTLS command
-void smtp_starttls(void) {
- char ok_response[SIZ];
- char nosup_response[SIZ];
- char error_response[SIZ];
-
- sprintf(ok_response, "220 Begin TLS negotiation now\r\n");
- sprintf(nosup_response, "554 TLS not supported here\r\n");
- sprintf(error_response, "554 Internal error\r\n");
- CtdlModuleStartCryptoMsgs(ok_response, nosup_response, error_response);
- smtp_rset(0);
-}
-
-
-// Implements the NOOP (NO OPeration) command
-void smtp_noop(void) {
- cprintf("250 NOOP\r\n");
-}
-
-
-// Implements the QUIT command
-void smtp_quit(void) {
- cprintf("221 Goodbye...\r\n");
- CC->kill_me = KILLME_CLIENT_LOGGED_OUT;
-}
-
-
-// Main command loop for SMTP server sessions.
-void smtp_command_loop(void) {
- static const ConstStr AuthPlainStr = {HKEY("AUTH PLAIN")};
-
- if (SMTP == NULL) {
- syslog(LOG_ERR, "serv_smtp: Session SMTP data is null. WTF? We will crash now.");
- abort();
- }
-
- time(&CC->lastcmd);
- if (CtdlClientGetLine(SMTP->Cmd) < 1) {
- syslog(LOG_INFO, "SMTP: client disconnected: ending session.");
- CC->kill_me = KILLME_CLIENT_DISCONNECTED;
- return;
- }
-
- if (SMTP->command_state == smtp_user) {
- if (!strncmp(ChrPtr(SMTP->Cmd), AuthPlainStr.Key, AuthPlainStr.len)) {
- smtp_try_plain();
- }
- else {
- smtp_get_user(0);
- }
- return;
- }
-
- else if (SMTP->command_state == smtp_password) {
- smtp_get_pass();
- return;
- }
-
- else if (SMTP->command_state == smtp_plain) {
- smtp_try_plain();
- return;
- }
-
- syslog(LOG_DEBUG, "serv_smtp: client sent command <%s>", ChrPtr(SMTP->Cmd));
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "NOOP", 4)) {
- smtp_noop();
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "QUIT", 4)) {
- smtp_quit();
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "HELO", 4)) {
- smtp_hello(HELO);
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "EHLO", 4)) {
- smtp_hello(EHLO);
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "LHLO", 4)) {
- smtp_hello(LHLO);
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "RSET", 4)) {
- smtp_rset(1);
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "AUTH", 4)) {
- smtp_auth();
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "DATA", 4)) {
- smtp_data();
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "HELP", 4)) {
- smtp_help();
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "MAIL", 4)) {
- smtp_mail();
- return;
- }
-
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "RCPT", 4)) {
- smtp_rcpt();
- return;
- }
-#ifdef HAVE_OPENSSL
- if (!strncasecmp(ChrPtr(SMTP->Cmd), "STARTTLS", 8)) {
- smtp_starttls();
- return;
- }
-#endif
-
- cprintf("502 I'm afraid I can't do that.\r\n");
-}
-
-
-/*****************************************************************************/
-/* MODULE INITIALIZATION STUFF */
-/*****************************************************************************/
-/*
- * This cleanup function blows away the temporary memory used by
- * the SMTP server.
- */
-void smtp_cleanup_function(void)
-{
- /* Don't do this stuff if this is not an SMTP session! */
- if (CC->h_command_function != smtp_command_loop) return;
-
- syslog(LOG_DEBUG, "Performing SMTP cleanup hook");
-
- FreeStrBuf(&SMTP->Cmd);
- FreeStrBuf(&SMTP->helo_node);
- FreeStrBuf(&SMTP->from);
- FreeStrBuf(&SMTP->recipients);
- FreeStrBuf(&SMTP->OneRcpt);
- FreeStrBuf(&SMTP->preferred_sender_email);
- FreeStrBuf(&SMTP->preferred_sender_name);
-
- free(SMTP);
-}
-
-const char *CitadelServiceSMTP_MTA="SMTP-MTA";
-const char *CitadelServiceSMTPS_MTA="SMTPs-MTA";
-const char *CitadelServiceSMTP_MSA="SMTP-MSA";
-const char *CitadelServiceSMTP_LMTP="LMTP";
-const char *CitadelServiceSMTP_LMTP_UNF="LMTP-UnF";
-
-
-CTDL_MODULE_INIT(smtp)
-{
- if (!threading) {
- CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtp_port"), /* SMTP MTA */
- NULL,
- smtp_mta_greeting,
- smtp_command_loop,
- NULL,
- CitadelServiceSMTP_MTA);
-
-#ifdef HAVE_OPENSSL
- CtdlRegisterServiceHook(CtdlGetConfigInt("c_smtps_port"), /* SMTPS MTA */
- NULL,
- smtps_greeting,
- smtp_command_loop,
- NULL,
- CitadelServiceSMTPS_MTA);
-#endif
-
- CtdlRegisterServiceHook(CtdlGetConfigInt("c_msa_port"), /* SMTP MSA */
- NULL,
- smtp_msa_greeting,
- smtp_command_loop,
- NULL,
- CitadelServiceSMTP_MSA);
-
- CtdlRegisterServiceHook(0, /* local LMTP */
- file_lmtp_socket,
- lmtp_greeting,
- smtp_command_loop,
- NULL,
- CitadelServiceSMTP_LMTP);
-
- CtdlRegisterServiceHook(0, /* local LMTP */
- file_lmtp_unfiltered_socket,
- lmtp_unfiltered_greeting,
- smtp_command_loop,
- NULL,
- CitadelServiceSMTP_LMTP_UNF);
-
- CtdlRegisterSessionHook(smtp_cleanup_function, EVT_STOP, PRIO_STOP + 250);
- }
-
- /* return our module name for the log */
- return "smtp";
-}
projects / citadel.git / blobdiff