1 /* $NetBSD: discard.c,v 1.2 2017/02/14 01:16:44 christos Exp $ */ 2 3 /*++ 4 /* NAME 5 /* discard 8 6 /* SUMMARY 7 /* Postfix discard mail delivery agent 8 /* SYNOPSIS 9 /* \fBdiscard\fR [generic Postfix daemon options] 10 /* DESCRIPTION 11 /* The Postfix \fBdiscard\fR(8) delivery agent processes 12 /* delivery requests from 13 /* the queue manager. Each request specifies a queue file, a sender 14 /* address, a next-hop destination that is treated as the reason for 15 /* discarding the mail, and recipient information. 16 /* The reason may be prefixed with an RFC 3463-compatible detail code. 17 /* This program expects to be run from the \fBmaster\fR(8) process 18 /* manager. 19 /* 20 /* The \fBdiscard\fR(8) delivery agent pretends to deliver all recipients 21 /* in the delivery request, logs the "next-hop" destination 22 /* as the reason for discarding the mail, updates the 23 /* queue file, and either marks recipients as finished or informs the 24 /* queue manager that delivery should be tried again at a later time. 25 /* 26 /* Delivery status reports are sent to the \fBtrace\fR(8) 27 /* daemon as appropriate. 28 /* SECURITY 29 /* .ad 30 /* .fi 31 /* The \fBdiscard\fR(8) mailer is not security-sensitive. It does not talk 32 /* to the network, and can be run chrooted at fixed low privilege. 33 /* STANDARDS 34 /* RFC 3463 (Enhanced Status Codes) 35 /* DIAGNOSTICS 36 /* Problems and transactions are logged to \fBsyslogd\fR(8). 37 /* 38 /* Depending on the setting of the \fBnotify_classes\fR parameter, 39 /* the postmaster is notified of bounces and of other trouble. 40 /* CONFIGURATION PARAMETERS 41 /* .ad 42 /* .fi 43 /* Changes to \fBmain.cf\fR are picked up automatically as \fBdiscard\fR(8) 44 /* processes run for only a limited amount of time. Use the command 45 /* "\fBpostfix reload\fR" to speed up a change. 46 /* 47 /* The text below provides only a parameter summary. See 48 /* \fBpostconf\fR(5) for more details including examples. 49 /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" 50 /* The default location of the Postfix main.cf and master.cf 51 /* configuration files. 52 /* .IP "\fBdaemon_timeout (18000s)\fR" 53 /* How much time a Postfix daemon process may take to handle a 54 /* request before it is terminated by a built-in watchdog timer. 55 /* .IP "\fBdelay_logging_resolution_limit (2)\fR" 56 /* The maximal number of digits after the decimal point when logging 57 /* sub-second delay values. 58 /* .IP "\fBdouble_bounce_sender (double-bounce)\fR" 59 /* The sender address of postmaster notifications that are generated 60 /* by the mail system. 61 /* .IP "\fBipc_timeout (3600s)\fR" 62 /* The time limit for sending or receiving information over an internal 63 /* communication channel. 64 /* .IP "\fBmax_idle (100s)\fR" 65 /* The maximum amount of time that an idle Postfix daemon process waits 66 /* for an incoming connection before terminating voluntarily. 67 /* .IP "\fBmax_use (100)\fR" 68 /* The maximal number of incoming connections that a Postfix daemon 69 /* process will service before terminating voluntarily. 70 /* .IP "\fBprocess_id (read-only)\fR" 71 /* The process ID of a Postfix command or daemon process. 72 /* .IP "\fBprocess_name (read-only)\fR" 73 /* The process name of a Postfix command or daemon process. 74 /* .IP "\fBqueue_directory (see 'postconf -d' output)\fR" 75 /* The location of the Postfix top-level queue directory. 76 /* .IP "\fBsyslog_facility (mail)\fR" 77 /* The syslog facility of Postfix logging. 78 /* .IP "\fBsyslog_name (see 'postconf -d' output)\fR" 79 /* The mail system name that is prepended to the process name in syslog 80 /* records, so that "smtpd" becomes, for example, "postfix/smtpd". 81 /* SEE ALSO 82 /* qmgr(8), queue manager 83 /* bounce(8), delivery status reports 84 /* error(8), Postfix error delivery agent 85 /* postconf(5), configuration parameters 86 /* master(5), generic daemon options 87 /* master(8), process manager 88 /* syslogd(8), system logging 89 /* LICENSE 90 /* .ad 91 /* .fi 92 /* The Secure Mailer license must be distributed with this software. 93 /* HISTORY 94 /* This service was introduced with Postfix version 2.2. 95 /* AUTHOR(S) 96 /* Victor Duchovni 97 /* Morgan Stanley 98 /* 99 /* Based on code by: 100 /* Wietse Venema 101 /* IBM T.J. Watson Research 102 /* P.O. Box 704 103 /* Yorktown Heights, NY 10598, USA 104 /* 105 /* Wietse Venema 106 /* Google, Inc. 107 /* 111 8th Avenue 108 /* New York, NY 10011, USA 109 /*--*/ 110 111 /* System library. */ 112 113 #include <sys_defs.h> 114 #include <unistd.h> 115 #include <stdlib.h> 116 117 /* Utility library. */ 118 119 #include <msg.h> 120 #include <vstream.h> 121 122 /* Global library. */ 123 124 #include <deliver_request.h> 125 #include <mail_queue.h> 126 #include <bounce.h> 127 #include <deliver_completed.h> 128 #include <flush_clnt.h> 129 #include <sent.h> 130 #include <dsn_util.h> 131 #include <mail_version.h> 132 133 /* Single server skeleton. */ 134 135 #include <mail_server.h> 136 137 /* deliver_message - deliver message with extreme prejudice */ 138 139 static int deliver_message(DELIVER_REQUEST *request) 140 { 141 const char *myname = "deliver_message"; 142 VSTREAM *src; 143 int result = 0; 144 int status; 145 RECIPIENT *rcpt; 146 int nrcpt; 147 DSN_SPLIT dp; 148 DSN dsn; 149 150 if (msg_verbose) 151 msg_info("deliver_message: from %s", request->sender); 152 153 /* 154 * Sanity checks. 155 */ 156 if (request->nexthop[0] == 0) 157 msg_fatal("empty nexthop hostname"); 158 if (request->rcpt_list.len <= 0) 159 msg_fatal("recipient count: %d", request->rcpt_list.len); 160 161 /* 162 * Open the queue file. Opening the file can fail for a variety of 163 * reasons, such as the system running out of resources. Instead of 164 * throwing away mail, we're raising a fatal error which forces the mail 165 * system to back off, and retry later. 166 */ 167 src = mail_queue_open(request->queue_name, request->queue_id, 168 O_RDWR, 0); 169 if (src == 0) 170 msg_fatal("%s: open %s %s: %m", myname, 171 request->queue_name, request->queue_id); 172 if (msg_verbose) 173 msg_info("%s: file %s", myname, VSTREAM_PATH(src)); 174 175 /* 176 * Discard all recipients. 177 */ 178 #define BOUNCE_FLAGS(request) DEL_REQ_TRACE_FLAGS(request->flags) 179 180 dsn_split(&dp, "2.0.0", request->nexthop); 181 (void) DSN_SIMPLE(&dsn, DSN_STATUS(dp.dsn), dp.text); 182 for (nrcpt = 0; nrcpt < request->rcpt_list.len; nrcpt++) { 183 rcpt = request->rcpt_list.info + nrcpt; 184 status = sent(BOUNCE_FLAGS(request), request->queue_id, 185 &request->msg_stats, rcpt, "none", &dsn); 186 if (status == 0 && (request->flags & DEL_REQ_FLAG_SUCCESS)) 187 deliver_completed(src, rcpt->offset); 188 result |= status; 189 } 190 191 /* 192 * Clean up. 193 */ 194 if (vstream_fclose(src)) 195 msg_warn("close %s %s: %m", request->queue_name, request->queue_id); 196 197 return (result); 198 } 199 200 /* discard_service - perform service for client */ 201 202 static void discard_service(VSTREAM *client_stream, char *unused_service, char **argv) 203 { 204 DELIVER_REQUEST *request; 205 int status; 206 207 /* 208 * Sanity check. This service takes no command-line arguments. 209 */ 210 if (argv[0]) 211 msg_fatal("unexpected command-line argument: %s", argv[0]); 212 213 /* 214 * This routine runs whenever a client connects to the UNIX-domain socket 215 * dedicated to the discard mailer. What we see below is a little 216 * protocol to (1) tell the queue manager that we are ready, (2) read a 217 * request from the queue manager, and (3) report the completion status 218 * of that request. All connection-management stuff is handled by the 219 * common code in single_server.c. 220 */ 221 if ((request = deliver_request_read(client_stream)) != 0) { 222 status = deliver_message(request); 223 deliver_request_done(client_stream, request, status); 224 } 225 } 226 227 /* pre_init - pre-jail initialization */ 228 229 static void pre_init(char *unused_name, char **unused_argv) 230 { 231 flush_init(); 232 } 233 234 MAIL_VERSION_STAMP_DECLARE; 235 236 /* main - pass control to the single-threaded skeleton */ 237 238 int main(int argc, char **argv) 239 { 240 241 /* 242 * Fingerprint executables and core dumps. 243 */ 244 MAIL_VERSION_STAMP_ALLOCATE; 245 246 single_server_main(argc, argv, discard_service, 247 CA_MAIL_SERVER_PRE_INIT(pre_init), 248 0); 249 } 250