+/*
+ * This module is an SMTP and ESMTP implementation 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) 1998-2009 by the citadel.org team
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#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>
+
+#if TIME_WITH_SYS_TIME
+# include <sys/time.h>
+# include <time.h>
+#else
+# if HAVE_SYS_TIME_H
+# include <sys/time.h>
+# else
+# include <time.h>
+# endif
+#endif
+#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 "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"
+#include "event_client.h"
+#include "smtpqueue.h"
+#include "smtp_clienthandlers.h"
+
+
+#define SMTP_ERROR(WHICH_ERR, ERRSTR) do {\
+ SendMsg->MyQEntry->Status = WHICH_ERR; \
+ StrBufAppendBufPlain(SendMsg->MyQEntry->StatusMessage, HKEY(ERRSTR), 0); \
+ return eAbort; } \
+ while (0)
+
+#define SMTP_VERROR(WHICH_ERR) do {\
+ SendMsg->MyQEntry->Status = WHICH_ERR; \
+ StrBufPlain(SendMsg->MyQEntry->StatusMessage, \
+ ChrPtr(SendMsg->IO.IOBuf) + 4, \
+ StrLength(SendMsg->IO.IOBuf) - 4); \
+ return eAbort; } \
+ while (0)
+
+#define SMTP_IS_STATE(WHICH_STATE) (ChrPtr(SendMsg->IO.IOBuf)[0] == WHICH_STATE)
+
+#define SMTP_DBG_SEND() CtdlLogPrintf(CTDL_DEBUG, "SMTP client[%ld]: > %s\n", SendMsg->n, ChrPtr(SendMsg->IO.SendBuf.Buf))
+#define SMTP_DBG_READ() CtdlLogPrintf(CTDL_DEBUG, "SMTP client[%ld]: < %s\n", SendMsg->n, ChrPtr(SendMsg->IO.IOBuf))
+
+
+/*****************************************************************************/
+/* SMTP CLIENT STATE CALLBACKS */
+/*****************************************************************************/
+eNextState SMTPC_read_greeting(SmtpOutMsg *SendMsg)
+{
+ /* Process the SMTP greeting from the server */
+ SMTP_DBG_READ();
+
+ if (!SMTP_IS_STATE('2')) {
+ if (SMTP_IS_STATE('4'))
+ SMTP_VERROR(4);
+ else
+ SMTP_VERROR(5);
+ }
+ return eSendReply;
+}
+
+eNextState SMTPC_send_EHLO(SmtpOutMsg *SendMsg)
+{
+ /* At this point we know we are talking to a real SMTP server */
+
+ /* Do a EHLO command. If it fails, try the HELO command. */
+ StrBufPrintf(SendMsg->IO.SendBuf.Buf,
+ "EHLO %s\r\n", config.c_fqdn);
+
+ SMTP_DBG_SEND();
+ return eReadMessage;
+}
+
+eNextState SMTPC_read_EHLO_reply(SmtpOutMsg *SendMsg)
+{
+ SMTP_DBG_READ();
+
+ if (SMTP_IS_STATE('2')) {
+ SendMsg->State ++;
+
+ if ((SendMsg->pCurrRelay == NULL) ||
+ (SendMsg->pCurrRelay->User == NULL))
+ SendMsg->State ++; /* Skip auth... */
+ }
+ /* else we fall back to 'helo' */
+ return eSendReply;
+}
+
+eNextState STMPC_send_HELO(SmtpOutMsg *SendMsg)
+{
+ StrBufPrintf(SendMsg->IO.SendBuf.Buf,
+ "HELO %s\r\n", config.c_fqdn);
+
+ SMTP_DBG_SEND();
+ return eReadMessage;
+}
+
+eNextState SMTPC_read_HELO_reply(SmtpOutMsg *SendMsg)
+{
+ SMTP_DBG_READ();
+
+ if (!SMTP_IS_STATE('2')) {
+ if (SMTP_IS_STATE('4'))
+ SMTP_VERROR(4);
+ else
+ SMTP_VERROR(5);
+ }
+ if ((SendMsg->pCurrRelay == NULL) ||
+ (SendMsg->pCurrRelay->User == NULL))
+ SendMsg->State ++; /* Skip auth... */
+ return eSendReply;
+}
+
+eNextState SMTPC_send_auth(SmtpOutMsg *SendMsg)
+{
+ char buf[SIZ];
+ char encoded[1024];
+
+ if ((SendMsg->pCurrRelay == NULL) ||
+ (SendMsg->pCurrRelay->User == NULL))
+ SendMsg->State ++; /* Skip auth, shouldn't even come here!... */
+ else {
+ /* Do an AUTH command if necessary */
+ sprintf(buf, "%s%c%s%c%s",
+ SendMsg->pCurrRelay->User, '\0',
+ SendMsg->pCurrRelay->User, '\0',
+ SendMsg->pCurrRelay->Pass);
+ CtdlEncodeBase64(encoded, buf,
+ strlen(SendMsg->pCurrRelay->User) * 2 +
+ strlen(SendMsg->pCurrRelay->Pass) + 2, 0);
+ StrBufPrintf(SendMsg->IO.SendBuf.Buf,
+ "AUTH PLAIN %s\r\n", encoded);
+ }
+ SMTP_DBG_SEND();
+ return eReadMessage;
+}
+
+eNextState SMTPC_read_auth_reply(SmtpOutMsg *SendMsg)
+{
+ /* Do an AUTH command if necessary */
+
+ SMTP_DBG_READ();
+
+ if (!SMTP_IS_STATE('2')) {
+ if (SMTP_IS_STATE('4'))
+ SMTP_VERROR(4);
+ else
+ SMTP_VERROR(5);
+ }
+ return eSendReply;
+}
+
+eNextState SMTPC_send_FROM(SmtpOutMsg *SendMsg)
+{
+ /* previous command succeeded, now try the MAIL FROM: command */
+ StrBufPrintf(SendMsg->IO.SendBuf.Buf,
+ "MAIL FROM:<%s>\r\n",
+ SendMsg->envelope_from);
+
+ SMTP_DBG_SEND();
+ return eReadMessage;
+}
+
+eNextState SMTPC_read_FROM_reply(SmtpOutMsg *SendMsg)
+{
+ SMTP_DBG_READ();
+
+ if (!SMTP_IS_STATE('2')) {
+ if (SMTP_IS_STATE('4'))
+ SMTP_VERROR(4);
+ else
+ SMTP_VERROR(5);
+ }
+ return eSendReply;
+}
+
+
+eNextState SMTPC_send_RCPT(SmtpOutMsg *SendMsg)
+{
+ /* MAIL succeeded, now try the RCPT To: command */
+ StrBufPrintf(SendMsg->IO.SendBuf.Buf,
+ "RCPT TO:<%s@%s>\r\n",
+ SendMsg->user,
+ SendMsg->node);
+
+ SMTP_DBG_SEND();
+ return eReadMessage;
+}
+
+eNextState SMTPC_read_RCPT_reply(SmtpOutMsg *SendMsg)
+{
+ SMTP_DBG_READ();
+
+ if (!SMTP_IS_STATE('2')) {
+ if (SMTP_IS_STATE('4'))
+ SMTP_VERROR(4);
+ else
+ SMTP_VERROR(5);
+ }
+ return eSendReply;
+}
+
+eNextState SMTPC_send_DATAcmd(SmtpOutMsg *SendMsg)
+{
+ /* RCPT succeeded, now try the DATA command */
+ StrBufPlain(SendMsg->IO.SendBuf.Buf,
+ HKEY("DATA\r\n"));
+
+ SMTP_DBG_SEND();
+ return eReadMessage;
+}
+
+eNextState SMTPC_read_DATAcmd_reply(SmtpOutMsg *SendMsg)
+{
+ SMTP_DBG_READ();
+
+ if (!SMTP_IS_STATE('3')) {
+ if (SMTP_IS_STATE('4'))
+ SMTP_VERROR(3);
+ else
+ SMTP_VERROR(5);
+ }
+ return eSendReply;
+}
+
+eNextState SMTPC_send_data_body(SmtpOutMsg *SendMsg)
+{
+ StrBuf *Buf;
+ /* If we reach this point, the server is expecting data.*/
+
+ Buf = SendMsg->IO.SendBuf.Buf;
+ SendMsg->IO.SendBuf.Buf = SendMsg->msgtext;
+ SendMsg->msgtext = Buf;
+ SendMsg->State ++;
+
+ return eSendMore;
+}
+
+eNextState SMTPC_send_terminate_data_body(SmtpOutMsg *SendMsg)
+{
+ StrBuf *Buf;
+
+ Buf = SendMsg->IO.SendBuf.Buf;
+ SendMsg->IO.SendBuf.Buf = SendMsg->msgtext;
+ SendMsg->msgtext = Buf;
+
+ StrBufPlain(SendMsg->IO.SendBuf.Buf,
+ HKEY(".\r\n"));
+
+ return eReadMessage;
+
+}
+
+eNextState SMTPC_read_data_body_reply(SmtpOutMsg *SendMsg)
+{
+ SMTP_DBG_READ();
+
+ if (!SMTP_IS_STATE('2')) {
+ if (SMTP_IS_STATE('4'))
+ SMTP_VERROR(4);
+ else
+ SMTP_VERROR(5);
+ }
+
+ /* We did it! */
+ StrBufPlain(SendMsg->MyQEntry->StatusMessage,
+ &ChrPtr(SendMsg->IO.RecvBuf.Buf)[4],
+ StrLength(SendMsg->IO.RecvBuf.Buf) - 4);
+ SendMsg->MyQEntry->Status = 2;
+ return eSendReply;
+}
+
+eNextState SMTPC_send_QUIT(SmtpOutMsg *SendMsg)
+{
+ StrBufPlain(SendMsg->IO.SendBuf.Buf,
+ HKEY("QUIT\r\n"));
+
+ SMTP_DBG_SEND();
+ return eReadMessage;
+}
+
+eNextState SMTPC_read_QUIT_reply(SmtpOutMsg *SendMsg)
+{
+ SMTP_DBG_READ();
+
+ CtdlLogPrintf(CTDL_INFO, "SMTP client[%ld]: delivery to <%s> @ <%s> (%s) succeeded\n",
+ SendMsg->n, SendMsg->user, SendMsg->node, SendMsg->name);
+ return eTerminateConnection;
+}
+
+eNextState SMTPC_read_dummy(SmtpOutMsg *SendMsg)
+{
+ return eSendReply;
+}
+
+eNextState SMTPC_send_dummy(SmtpOutMsg *SendMsg)
+{
+ return eReadMessage;
+}
+
+/*****************************************************************************/
+/* SMTP CLIENT DISPATCHER */
+/*****************************************************************************/
+SMTPReadHandler ReadHandlers[eMaxSMTPC] = {
+ SMTPC_read_greeting,
+ SMTPC_read_EHLO_reply,
+ SMTPC_read_HELO_reply,
+ SMTPC_read_auth_reply,
+ SMTPC_read_FROM_reply,
+ SMTPC_read_RCPT_reply,
+ SMTPC_read_DATAcmd_reply,
+ SMTPC_read_dummy,
+ SMTPC_read_data_body_reply,
+ SMTPC_read_QUIT_reply
+};
+SMTPSendHandler SendHandlers[eMaxSMTPC] = {
+ SMTPC_send_dummy, /* we don't send a greeting, the server does... */
+ SMTPC_send_EHLO,
+ STMPC_send_HELO,
+ SMTPC_send_auth,
+ SMTPC_send_FROM,
+ SMTPC_send_RCPT,
+ SMTPC_send_DATAcmd,
+ SMTPC_send_data_body,
+ SMTPC_send_terminate_data_body,
+ SMTPC_send_QUIT
+};
+
+const double SMTP_C_ConnTimeout = 300.; /* wail 1 minute for connections... */
+
+const double SMTP_C_ReadTimeouts[eMaxSMTPC] = {
+ 300., /* Greeting... */
+ 30., /* EHLO */
+ 30., /* HELO */
+ 30., /* Auth */
+ 30., /* From */
+ 90., /* RCPT */
+ 30., /* DATA */
+ 90., /* DATABody */
+ 90., /* end of body... */
+ 30. /* QUIT */
+};
+const double SMTP_C_SendTimeouts[eMaxSMTPC] = {
+ 90., /* Greeting... */
+ 30., /* EHLO */
+ 30., /* HELO */
+ 30., /* Auth */
+ 30., /* From */
+ 30., /* RCPT */
+ 30., /* DATA */
+ 90., /* DATABody */
+ 900., /* end of body... */
+ 30. /* QUIT */
+};
+
+const ConstStr ReadErrors[eMaxSMTPC] = {
+ {HKEY("Connection broken during SMTP conversation")},
+ {HKEY("Connection broken during SMTP EHLO")},
+ {HKEY("Connection broken during SMTP HELO")},
+ {HKEY("Connection broken during SMTP AUTH")},
+ {HKEY("Connection broken during SMTP MAIL FROM")},
+ {HKEY("Connection broken during SMTP RCPT")},
+ {HKEY("Connection broken during SMTP DATA")},
+ {HKEY("Connection broken during SMTP message transmit")},
+ {HKEY("")}/* quit reply, don't care. */
+};
+
+
+
+
+
+int smtp_resolve_recipients(SmtpOutMsg *SendMsg)
+{
+ const char *ptr;
+ char buf[1024];
+ int scan_done;
+ int lp, rp;
+ int i;
+
+ CtdlLogPrintf(CTDL_DEBUG, "SMTP: %s\n", __FUNCTION__);
+
+ if ((SendMsg==NULL) ||
+ (SendMsg->MyQEntry == NULL) ||
+ (StrLength(SendMsg->MyQEntry->Recipient) == 0)) {
+ return 0;
+ }
+
+ /* Parse out the host portion of the recipient address */
+ process_rfc822_addr(ChrPtr(SendMsg->MyQEntry->Recipient),
+ SendMsg->user,
+ SendMsg->node,
+ SendMsg->name);
+
+ CtdlLogPrintf(CTDL_DEBUG, "SMTP client[%ld]: Attempting delivery to <%s> @ <%s> (%s)\n",
+ SendMsg->n, SendMsg->user, SendMsg->node, SendMsg->name);
+ /* If no envelope_from is supplied, extract one from the message */
+ SendMsg->envelope_from = ChrPtr(SendMsg->MyQItem->EnvelopeFrom);
+ if ( (SendMsg->envelope_from == NULL) ||
+ (IsEmptyStr(SendMsg->envelope_from)) ) {
+ SendMsg->mailfrom[0] = '\0';
+ scan_done = 0;
+ ptr = ChrPtr(SendMsg->msgtext);
+ do {
+ if (ptr = cmemreadline(ptr, buf, sizeof buf), *ptr == 0) {
+ scan_done = 1;
+ }
+ if (!strncasecmp(buf, "From:", 5)) {
+ safestrncpy(SendMsg->mailfrom, &buf[5], sizeof SendMsg->mailfrom);
+ striplt(SendMsg->mailfrom);
+ for (i=0; SendMsg->mailfrom[i]; ++i) {
+ if (!isprint(SendMsg->mailfrom[i])) {
+ strcpy(&SendMsg->mailfrom[i], &SendMsg->mailfrom[i+1]);
+ i=0;
+ }
+ }
+
+ /* Strip out parenthesized names */
+ lp = (-1);
+ rp = (-1);
+ for (i=0; !IsEmptyStr(SendMsg->mailfrom + i); ++i) {
+ if (SendMsg->mailfrom[i] == '(') lp = i;
+ if (SendMsg->mailfrom[i] == ')') rp = i;
+ }
+ if ((lp>0)&&(rp>lp)) {
+ strcpy(&SendMsg->mailfrom[lp-1], &SendMsg->mailfrom[rp+1]);
+ }
+
+ /* Prefer brokketized names */
+ lp = (-1);
+ rp = (-1);
+ for (i=0; !IsEmptyStr(SendMsg->mailfrom + i); ++i) {
+ if (SendMsg->mailfrom[i] == '<') lp = i;
+ if (SendMsg->mailfrom[i] == '>') rp = i;
+ }
+ if ( (lp>=0) && (rp>lp) ) {
+ SendMsg->mailfrom[rp] = 0;
+ memmove(SendMsg->mailfrom,
+ &SendMsg->mailfrom[lp + 1],
+ rp - lp);
+ }
+
+ scan_done = 1;
+ }
+ } while (scan_done == 0);
+ if (IsEmptyStr(SendMsg->mailfrom)) strcpy(SendMsg->mailfrom, "someone@somewhere.org");
+ stripallbut(SendMsg->mailfrom, '<', '>');
+ SendMsg->envelope_from = SendMsg->mailfrom;
+ }
+
+ return 1;
+}