/*++ /* NAME /* lmtp 8 /* SUMMARY /* Postfix local delivery via LMTP /* SYNOPSIS /* \fBlmtp\fR [generic Postfix daemon options] /* DESCRIPTION /* The LMTP client processes message delivery requests from /* the queue manager. Each request specifies a queue file, a sender /* address, a domain or host to deliver to, and recipient information. /* This program expects to be run from the \fBmaster\fR(8) process /* manager. /* /* The LMTP client updates the queue file and marks recipients /* as finished, or it informs the queue manager that delivery should /* be tried again at a later time. Delivery status reports are sent /* to the \fBbounce\fR(8), \fBdefer\fR(8) or \fBtrace\fR(8) daemon as /* appropriate. /* /* The LMTP client connects to the destination specified in the message /* delivery request. The destination, usually specified in the Postfix /* \fBtransport\fR(5) table, has the form: /* .IP \fBunix\fR:\fIpathname\fR /* Connect to the local UNIX-domain server that is bound to the specified /* \fIpathname\fR. If the process runs chrooted, an absolute pathname /* is interpreted relative to the changed root directory. /* .IP "\fBinet\fR:\fIhost\fR, \fBinet\fB:\fIhost\fR:\fIport\fR (symbolic host)" /* .IP "\fBinet\fR:[\fIaddr\fR], \fBinet\fR:[\fIaddr\fR]:\fIport\fR (numeric host)" /* Connect to the specified IPV4 TCP port on the specified local or /* remote host. If no port is specified, connect to the port defined as /* \fBlmtp\fR in \fBservices\fR(4). /* If no such service is found, the \fBlmtp_tcp_port\fR configuration /* parameter (default value of 24) will be used. /* /* The LMTP client does not perform MX (mail exchanger) lookups since /* those are defined only for mail delivery via SMTP. /* .PP /* If neither \fBunix:\fR nor \fBinet:\fR are specified, \fBinet:\fR /* is assumed. /* SECURITY /* .ad /* .fi /* The LMTP client is moderately security-sensitive. It talks to LMTP /* servers and to DNS servers on the network. The LMTP client can be /* run chrooted at fixed low privilege. /* STANDARDS /* RFC 821 (SMTP protocol) /* RFC 1651 (SMTP service extensions) /* RFC 1652 (8bit-MIME transport) /* RFC 1870 (Message Size Declaration) /* RFC 2033 (LMTP protocol) /* RFC 2554 (AUTH command) /* RFC 2821 (SMTP protocol) /* RFC 2920 (SMTP Pipelining) /* DIAGNOSTICS /* Problems and transactions are logged to \fBsyslogd\fR(8). /* Corrupted message files are marked so that the queue manager can /* move them to the \fBcorrupt\fR queue for further inspection. /* /* Depending on the setting of the \fBnotify_classes\fR parameter, /* the postmaster is notified of bounces, protocol problems, and of /* other trouble. /* CONFIGURATION PARAMETERS /* .ad /* .fi /* Changes to \fBmain.cf\fR are picked up automatically, as lmtp(8) /* processes run for only a limited amount of time. Use the command /* "\fBpostfix reload\fR" to speed up a change. /* /* The text below provides only a parameter summary. See /* postconf(5) for more details including examples. /* COMPATIBILITY CONTROLS /* .ad /* .fi /* .IP "\fBlmtp_skip_quit_response (no)\fR" /* Wait for the response to the LMTP QUIT command. /* TROUBLE SHOOTING CONTROLS /* .ad /* .fi /* .IP "\fBdebug_peer_level (2)\fR" /* The increment in verbose logging level when a remote client or /* server matches a pattern in the debug_peer_list parameter. /* .IP "\fBdebug_peer_list (empty)\fR" /* Optional list of remote client or server hostname or network /* address patterns that cause the verbose logging level to increase /* by the amount specified in $debug_peer_level. /* .IP "\fBerror_notice_recipient (postmaster)\fR" /* The recipient of postmaster notifications about mail delivery /* problems that are caused by policy, resource, software or protocol /* errors. /* .IP "\fBnotify_classes (resource, software)\fR" /* The list of error classes that are reported to the postmaster. /* EXTERNAL CONTENT INSPECTION CONTROLS /* .ad /* .fi /* Available in Postfix version 2.1 and later: /* .IP "\fBlmtp_send_xforward_command (no)\fR" /* Send an XFORWARD command to the LMTP server when the LMTP LHLO /* server response announces XFORWARD support. /* SASL AUTHENTICATION CONTROLS /* .ad /* .fi /* .IP "\fBlmtp_sasl_auth_enable (no)\fR" /* Enable SASL authentication in the Postfix LMTP client. /* .IP "\fBlmtp_sasl_password_maps (empty)\fR" /* Optional LMTP client lookup tables with one username:password entry /* per host or domain. /* .IP "\fBlmtp_sasl_security_options (noplaintext, noanonymous)\fR" /* What authentication mechanisms the Postfix LMTP client is allowed /* to use. /* RESOURCE AND RATE CONTROLS /* .ad /* .fi /* In the text below, \fItransport\fR is the name /* of the service as specified in the \fBmaster.cf\fR file. /* .IP "\fBlmtp_cache_connection (yes)\fR" /* Keep Postfix LMTP client connections open for up to $max_idle /* seconds. /* .IP "\fItransport_\fBdestination_concurrency_limit ($default_destination_concurrency_limit)\fR" /* Limit the number of parallel deliveries to the same destination /* via this mail delivery transport. /* .IP "\fItransport_\fBdestination_recipient_limit ($default_destination_recipient_limit)\fR" /* Limit the number of recipients per message delivery via this mail /* delivery transport. /* /* This parameter becomes significant if the LMTP client is used /* for local delivery. Some LMTP servers can optimize delivery of /* the same message to multiple recipients. The default limit for /* local mail delivery is 1. /* /* Setting this parameter to 0 will lead to an unbounded number of /* recipients per delivery. However, this could be risky since it may /* make the machine vulnerable to running out of resources if messages /* are encountered with an inordinate number of recipients. Exercise /* care when setting this parameter. /* .IP "\fBlmtp_connect_timeout (0s)\fR" /* The LMTP client time limit for completing a TCP connection, or /* zero (use the operating system built-in time limit). /* .IP "\fBlmtp_lhlo_timeout (300s)\fR" /* The LMTP client time limit for receiving the LMTP greeting /* banner. /* .IP "\fBlmtp_xforward_timeout (300s)\fR" /* The LMTP client time limit for sending the XFORWARD command, and /* for receiving the server response. /* .IP "\fBlmtp_mail_timeout (300s)\fR" /* The LMTP client time limit for sending the MAIL FROM command, and /* for receiving the server response. /* .IP "\fBlmtp_rcpt_timeout (300s)\fR" /* The LMTP client time limit for sending the RCPT TO command, and /* for receiving the server response. /* .IP "\fBlmtp_data_init_timeout (120s)\fR" /* The LMTP client time limit for sending the LMTP DATA command, and /* for receiving the server response. /* .IP "\fBlmtp_data_xfer_timeout (180s)\fR" /* The LMTP client time limit for sending the LMTP message content. /* .IP "\fBlmtp_data_done_timeout (600s)\fR" /* The LMTP client time limit for sending the LMTP ".", and for /* receiving the server response. /* .IP "\fBlmtp_rset_timeout (120s)\fR" /* The LMTP client time limit for sending the RSET command, and for /* receiving the server response. /* .IP "\fBlmtp_quit_timeout (300s)\fR" /* The LMTP client time limit for sending the QUIT command, and for /* receiving the server response. /* MISCELLANEOUS CONTROLS /* .ad /* .fi /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" /* The default location of the Postfix main.cf and master.cf /* configuration files. /* .IP "\fBdaemon_timeout (18000s)\fR" /* How much time a Postfix daemon process may take to handle a /* request before it is terminated by a built-in watchdog timer. /* .IP "\fBdisable_dns_lookups (no)\fR" /* Disable DNS lookups in the Postfix SMTP and LMTP clients. /* .IP "\fBipc_timeout (3600s)\fR" /* The time limit for sending or receiving information over an internal /* communication channel. /* .IP "\fBlmtp_tcp_port (24)\fR" /* The default TCP port that the Postfix LMTP client connects to. /* .IP "\fBmax_idle (100s)\fR" /* The maximum amount of time that an idle Postfix daemon process /* waits for the next service request before exiting. /* .IP "\fBmax_use (100)\fR" /* The maximal number of connection requests before a Postfix daemon /* process terminates. /* .IP "\fBprocess_id (read-only)\fR" /* The process ID of a Postfix command or daemon process. /* .IP "\fBprocess_name (read-only)\fR" /* The process name of a Postfix command or daemon process. /* .IP "\fBqueue_directory (see 'postconf -d' output)\fR" /* The location of the Postfix top-level queue directory. /* .IP "\fBsyslog_facility (mail)\fR" /* The syslog facility of Postfix logging. /* .IP "\fBsyslog_name (postfix)\fR" /* The mail system name that is prepended to the process name in syslog /* records, so that "smtpd" becomes, for example, "postfix/smtpd". /* SEE ALSO /* bounce(8), delivery status reports /* qmgr(8), queue manager /* postconf(5), configuration parameters /* services(4), Internet services and aliases /* master(8), process manager /* syslogd(8), system logging /* README FILES /* .ad /* .fi /* Use "\fBpostconf readme_directory\fR" or /* "\fBpostconf html_directory\fR" to locate this information. /* .na /* .nf /* LMTP_README, Postfix LMTP client howto /* VIRTUAL_README, virtual delivery agent howto /* 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 /* /* Alterations for LMTP by: /* Philip A. Prindeville /* Mirapoint, Inc. /* USA. /* /* Additional work on LMTP by: /* Amos Gouaux /* University of Texas at Dallas /* P.O. Box 830688, MC34 /* Richardson, TX 75083, USA /*--*/ /* System library. */ #include <sys_defs.h> #include <unistd.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <dict.h> /* Utility library. */ #include <msg.h> #include <argv.h> #include <mymalloc.h> #include <name_mask.h> #include <split_at.h> /* Global library. */ #include <deliver_request.h> #include <mail_queue.h> #include <mail_params.h> #include <mail_conf.h> #include <debug_peer.h> #include <mail_error.h> #include <flush_clnt.h> /* Single server skeleton. */ #include <mail_server.h> /* Application-specific. */ #include "lmtp.h" #include "lmtp_sasl.h" /* * Tunable parameters. These have compiled-in defaults that can be overruled * by settings in the global Postfix configuration file. */ int var_lmtp_tcp_port; int var_lmtp_conn_tmout; int var_lmtp_rset_tmout; int var_lmtp_lhlo_tmout; int var_lmtp_xfwd_tmout; int var_lmtp_mail_tmout; int var_lmtp_rcpt_tmout; int var_lmtp_data0_tmout; int var_lmtp_data1_tmout; int var_lmtp_data2_tmout; int var_lmtp_quit_tmout; int var_lmtp_cache_conn; int var_lmtp_skip_quit_resp; char *var_notify_classes; char *var_error_rcpt; char *var_lmtp_sasl_opts; char *var_lmtp_sasl_passwd; bool var_lmtp_sasl_enable; bool var_lmtp_send_xforward; /* * Global variables. * * lmtp_errno is set by the address lookup routines and by the connection * management routines. * * state is global for the connection caching to work. */ int lmtp_errno; static LMTP_STATE *state = 0; /* deliver_message - deliver message with extreme prejudice */ static int deliver_message(DELIVER_REQUEST *request, char **unused_argv) { char *myname = "deliver_message"; VSTRING *why; int result; if (msg_verbose) msg_info("%s: from %s", myname, request->sender); /* * Sanity checks. */ if (request->rcpt_list.len <= 0) msg_fatal("%s: recipient count: %d", myname, request->rcpt_list.len); /* * Initialize. Bundle all information about the delivery request, so that * we can produce understandable diagnostics when something goes wrong * many levels below. The alternative would be to make everything global. * * Note: `state' was made global (to this file) so that we can cache * connections and so that we can close a cached connection via the * MAIL_SERVER_EXIT function (cleanup). The alloc for `state' is * performed in the MAIL_SERVER_PRE_INIT function (pre_init). * */ why = vstring_alloc(100); state->request = request; state->src = request->fp; /* * See if we can reuse an existing connection. */ if (state->session != 0) { /* * Disconnect if we're going to a different destination. Discard * transcript and status information for sending QUIT. * * XXX Should transform nexthop into canonical form (unix:/path or * inet:host:port) before doing connection cache lookup. See also the * connection cache updating code in lmtp_connect.c. */ if (strcasecmp(state->session->dest, request->nexthop) != 0) { lmtp_quit(state); lmtp_chat_reset(state); state->session = lmtp_session_free(state->session); #ifdef USE_SASL_AUTH if (var_lmtp_sasl_enable) lmtp_sasl_cleanup(state); #endif } /* * Disconnect if RSET can't be sent over an existing connection. * Discard transcript and status information for sending RSET. */ else if (lmtp_rset(state) != 0) { lmtp_chat_reset(state); state->session = lmtp_session_free(state->session); #ifdef USE_SASL_AUTH if (var_lmtp_sasl_enable) lmtp_sasl_cleanup(state); #endif } /* * Ready to go with another load. The reuse counter is logged for * statistical analysis purposes. Given the Postfix architecture, * connection cacheing makes sense only for dedicated transports. * Logging the reuse count can help to convince people. */ else { ++state->reuse; if (msg_verbose) msg_info("%s: reusing (count %d) session with: %s", myname, state->reuse, state->session->host); } } /* * See if we need to establish an LMTP connection. */ if (state->session == 0) { /* * Bounce or defer the recipients if no connection can be made. */ if ((state->session = lmtp_connect(request->nexthop, why)) == 0) { lmtp_site_fail(state, lmtp_errno == LMTP_RETRY ? 450 : 550, "%s", vstring_str(why)); } /* * Bounce or defer the recipients if the LMTP handshake fails. */ else if (lmtp_lhlo(state) != 0) { state->session = lmtp_session_free(state->session); #ifdef USE_SASL_AUTH if (var_lmtp_sasl_enable) lmtp_sasl_cleanup(state); #endif } /* * Congratulations. We just established a new LMTP connection. */ else state->reuse = 0; } /* * If a session exists, deliver this message to all requested recipients. */ if (state->session != 0) lmtp_xfer(state); /* * Optionally, notify the postmaster of problems with establishing a * session or with delivering mail. */ if (state->history != 0 && (state->error_mask & name_mask(VAR_NOTIFY_CLASSES, mail_error_masks, var_notify_classes))) lmtp_chat_notify(state); /* * Disconnect if we're not caching connections. The pipelined protocol * state machine knows if it should have sent a QUIT command. Do not * cache a broken connection. */ if (state->session != 0 && (!var_lmtp_cache_conn || vstream_ferror(state->session->stream) || vstream_feof(state->session->stream))) state->session = lmtp_session_free(state->session); /* * Clean up. */ vstring_free(why); result = state->status; lmtp_chat_reset(state); /* * XXX State persists until idle timeout, but these fields will be * dangling pointers. Nuke them. */ state->request = 0; state->src = 0; return (result); } /* lmtp_service - perform service for client */ static void lmtp_service(VSTREAM *client_stream, char *unused_service, char **argv) { DELIVER_REQUEST *request; int status; /* * Sanity check. This service takes no command-line arguments. */ if (argv[0]) msg_fatal("unexpected command-line argument: %s", argv[0]); /* * This routine runs whenever a client connects to the UNIX-domain socket * dedicated to remote LMTP delivery service. What we see below is a * little protocol to (1) tell the queue manager that we are ready, (2) * read a request from the queue manager, and (3) report the completion * status of that request. All connection-management stuff is handled by * the common code in single_server.c. */ if ((request = deliver_request_read(client_stream)) != 0) { status = deliver_message(request, argv); deliver_request_done(client_stream, request, status); } } /* post_init - post-jail initialization */ static void post_init(char *unused_name, char **unused_argv) { state = lmtp_state_alloc(); } /* pre_init - pre-jail initialization */ static void pre_init(char *unused_name, char **unused_argv) { debug_peer_init(); if (var_lmtp_sasl_enable) #ifdef USE_SASL_AUTH lmtp_sasl_initialize(); #else msg_warn("%s is true, but SASL support is not compiled in", VAR_LMTP_SASL_ENABLE); #endif /* * flush client. */ flush_init(); } /* cleanup - close any open connections, etc. */ static void cleanup(void) { if (state->session != 0) { lmtp_quit(state); lmtp_chat_reset(state); state->session = lmtp_session_free(state->session); if (msg_verbose) msg_info("cleanup: just closed down session"); } lmtp_state_free(state); #ifdef USE_SASL_AUTH if (var_lmtp_sasl_enable) sasl_done(); #endif } /* pre_accept - see if tables have changed */ static void pre_accept(char *unused_name, char **unused_argv) { const char *table; if ((table = dict_changed_name()) != 0) { msg_info("table %s has changed -- restarting", table); cleanup(); exit(0); } } /* main - pass control to the single-threaded skeleton */ int main(int argc, char **argv) { static CONFIG_STR_TABLE str_table[] = { VAR_NOTIFY_CLASSES, DEF_NOTIFY_CLASSES, &var_notify_classes, 0, 0, VAR_ERROR_RCPT, DEF_ERROR_RCPT, &var_error_rcpt, 1, 0, VAR_LMTP_SASL_PASSWD, DEF_LMTP_SASL_PASSWD, &var_lmtp_sasl_passwd, 0, 0, VAR_LMTP_SASL_OPTS, DEF_LMTP_SASL_OPTS, &var_lmtp_sasl_opts, 0, 0, 0, }; static CONFIG_INT_TABLE int_table[] = { VAR_LMTP_TCP_PORT, DEF_LMTP_TCP_PORT, &var_lmtp_tcp_port, 0, 0, 0, }; static CONFIG_TIME_TABLE time_table[] = { VAR_LMTP_CONN_TMOUT, DEF_LMTP_CONN_TMOUT, &var_lmtp_conn_tmout, 0, 0, VAR_LMTP_RSET_TMOUT, DEF_LMTP_RSET_TMOUT, &var_lmtp_rset_tmout, 1, 0, VAR_LMTP_LHLO_TMOUT, DEF_LMTP_LHLO_TMOUT, &var_lmtp_lhlo_tmout, 1, 0, VAR_LMTP_XFWD_TMOUT, DEF_LMTP_XFWD_TMOUT, &var_lmtp_xfwd_tmout, 1, 0, VAR_LMTP_MAIL_TMOUT, DEF_LMTP_MAIL_TMOUT, &var_lmtp_mail_tmout, 1, 0, VAR_LMTP_RCPT_TMOUT, DEF_LMTP_RCPT_TMOUT, &var_lmtp_rcpt_tmout, 1, 0, VAR_LMTP_DATA0_TMOUT, DEF_LMTP_DATA0_TMOUT, &var_lmtp_data0_tmout, 1, 0, VAR_LMTP_DATA1_TMOUT, DEF_LMTP_DATA1_TMOUT, &var_lmtp_data1_tmout, 1, 0, VAR_LMTP_DATA2_TMOUT, DEF_LMTP_DATA2_TMOUT, &var_lmtp_data2_tmout, 1, 0, VAR_LMTP_QUIT_TMOUT, DEF_LMTP_QUIT_TMOUT, &var_lmtp_quit_tmout, 1, 0, 0, }; static CONFIG_BOOL_TABLE bool_table[] = { VAR_LMTP_CACHE_CONN, DEF_LMTP_CACHE_CONN, &var_lmtp_cache_conn, VAR_LMTP_SKIP_QUIT_RESP, DEF_LMTP_SKIP_QUIT_RESP, &var_lmtp_skip_quit_resp, VAR_LMTP_SASL_ENABLE, DEF_LMTP_SASL_ENABLE, &var_lmtp_sasl_enable, VAR_LMTP_SEND_XFORWARD, DEF_LMTP_SEND_XFORWARD, &var_lmtp_send_xforward, 0, }; single_server_main(argc, argv, lmtp_service, MAIL_SERVER_INT_TABLE, int_table, MAIL_SERVER_STR_TABLE, str_table, MAIL_SERVER_BOOL_TABLE, bool_table, MAIL_SERVER_TIME_TABLE, time_table, MAIL_SERVER_PRE_INIT, pre_init, MAIL_SERVER_POST_INIT, post_init, MAIL_SERVER_PRE_ACCEPT, pre_accept, MAIL_SERVER_EXIT, cleanup, 0); }