1 /* $NetBSD: discard.c,v 1.3 2020/03/18 19:05:15 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 /* or \fBpostlogd\fR(8). 38 /* 39 /* Depending on the setting of the \fBnotify_classes\fR parameter, 40 /* the postmaster is notified of bounces and of other trouble. 41 /* CONFIGURATION PARAMETERS 42 /* .ad 43 /* .fi 44 /* Changes to \fBmain.cf\fR are picked up automatically as \fBdiscard\fR(8) 45 /* processes run for only a limited amount of time. Use the command 46 /* "\fBpostfix reload\fR" to speed up a change. 47 /* 48 /* The text below provides only a parameter summary. See 49 /* \fBpostconf\fR(5) for more details including examples. 50 /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" 51 /* The default location of the Postfix main.cf and master.cf 52 /* configuration files. 53 /* .IP "\fBdaemon_timeout (18000s)\fR" 54 /* How much time a Postfix daemon process may take to handle a 55 /* request before it is terminated by a built-in watchdog timer. 56 /* .IP "\fBdelay_logging_resolution_limit (2)\fR" 57 /* The maximal number of digits after the decimal point when logging 58 /* sub-second delay values. 59 /* .IP "\fBdouble_bounce_sender (double-bounce)\fR" 60 /* The sender address of postmaster notifications that are generated 61 /* by the mail system. 62 /* .IP "\fBipc_timeout (3600s)\fR" 63 /* The time limit for sending or receiving information over an internal 64 /* communication channel. 65 /* .IP "\fBmax_idle (100s)\fR" 66 /* The maximum amount of time that an idle Postfix daemon process waits 67 /* for an incoming connection before terminating voluntarily. 68 /* .IP "\fBmax_use (100)\fR" 69 /* The maximal number of incoming connections that a Postfix daemon 70 /* process will service before terminating voluntarily. 71 /* .IP "\fBprocess_id (read-only)\fR" 72 /* The process ID of a Postfix command or daemon process. 73 /* .IP "\fBprocess_name (read-only)\fR" 74 /* The process name of a Postfix command or daemon process. 75 /* .IP "\fBqueue_directory (see 'postconf -d' output)\fR" 76 /* The location of the Postfix top-level queue directory. 77 /* .IP "\fBsyslog_facility (mail)\fR" 78 /* The syslog facility of Postfix logging. 79 /* .IP "\fBsyslog_name (see 'postconf -d' output)\fR" 80 /* A prefix that is prepended to the process name in syslog 81 /* records, so that, for example, "smtpd" becomes "prefix/smtpd". 82 /* .PP 83 /* Available in Postfix 3.3 and later: 84 /* .IP "\fBservice_name (read-only)\fR" 85 /* The master.cf service name of a Postfix daemon process. 86 /* SEE ALSO 87 /* qmgr(8), queue manager 88 /* bounce(8), delivery status reports 89 /* error(8), Postfix error delivery agent 90 /* postconf(5), configuration parameters 91 /* master(5), generic daemon options 92 /* master(8), process manager 93 /* postlogd(8), Postfix logging 94 /* syslogd(8), system logging 95 /* LICENSE 96 /* .ad 97 /* .fi 98 /* The Secure Mailer license must be distributed with this software. 99 /* HISTORY 100 /* This service was introduced with Postfix version 2.2. 101 /* AUTHOR(S) 102 /* Victor Duchovni 103 /* Morgan Stanley 104 /* 105 /* Based on code by: 106 /* Wietse Venema 107 /* IBM T.J. Watson Research 108 /* P.O. Box 704 109 /* Yorktown Heights, NY 10598, USA 110 /* 111 /* Wietse Venema 112 /* Google, Inc. 113 /* 111 8th Avenue 114 /* New York, NY 10011, USA 115 /*--*/ 116 117 /* System library. */ 118 119 #include <sys_defs.h> 120 #include <unistd.h> 121 #include <stdlib.h> 122 123 /* Utility library. */ 124 125 #include <msg.h> 126 #include <vstream.h> 127 128 /* Global library. */ 129 130 #include <deliver_request.h> 131 #include <mail_queue.h> 132 #include <bounce.h> 133 #include <deliver_completed.h> 134 #include <flush_clnt.h> 135 #include <sent.h> 136 #include <dsn_util.h> 137 #include <mail_version.h> 138 139 /* Single server skeleton. */ 140 141 #include <mail_server.h> 142 143 /* deliver_message - deliver message with extreme prejudice */ 144 145 static int deliver_message(DELIVER_REQUEST *request) 146 { 147 const char *myname = "deliver_message"; 148 VSTREAM *src; 149 int result = 0; 150 int status; 151 RECIPIENT *rcpt; 152 int nrcpt; 153 DSN_SPLIT dp; 154 DSN dsn; 155 156 if (msg_verbose) 157 msg_info("deliver_message: from %s", request->sender); 158 159 /* 160 * Sanity checks. 161 */ 162 if (request->nexthop[0] == 0) 163 msg_fatal("empty nexthop hostname"); 164 if (request->rcpt_list.len <= 0) 165 msg_fatal("recipient count: %d", request->rcpt_list.len); 166 167 /* 168 * Open the queue file. Opening the file can fail for a variety of 169 * reasons, such as the system running out of resources. Instead of 170 * throwing away mail, we're raising a fatal error which forces the mail 171 * system to back off, and retry later. 172 */ 173 src = mail_queue_open(request->queue_name, request->queue_id, 174 O_RDWR, 0); 175 if (src == 0) 176 msg_fatal("%s: open %s %s: %m", myname, 177 request->queue_name, request->queue_id); 178 if (msg_verbose) 179 msg_info("%s: file %s", myname, VSTREAM_PATH(src)); 180 181 /* 182 * Discard all recipients. 183 */ 184 #define BOUNCE_FLAGS(request) DEL_REQ_TRACE_FLAGS(request->flags) 185 186 dsn_split(&dp, "2.0.0", request->nexthop); 187 (void) DSN_SIMPLE(&dsn, DSN_STATUS(dp.dsn), dp.text); 188 for (nrcpt = 0; nrcpt < request->rcpt_list.len; nrcpt++) { 189 rcpt = request->rcpt_list.info + nrcpt; 190 status = sent(BOUNCE_FLAGS(request), request->queue_id, 191 &request->msg_stats, rcpt, "none", &dsn); 192 if (status == 0 && (request->flags & DEL_REQ_FLAG_SUCCESS)) 193 deliver_completed(src, rcpt->offset); 194 result |= status; 195 } 196 197 /* 198 * Clean up. 199 */ 200 if (vstream_fclose(src)) 201 msg_warn("close %s %s: %m", request->queue_name, request->queue_id); 202 203 return (result); 204 } 205 206 /* discard_service - perform service for client */ 207 208 static void discard_service(VSTREAM *client_stream, char *unused_service, char **argv) 209 { 210 DELIVER_REQUEST *request; 211 int status; 212 213 /* 214 * Sanity check. This service takes no command-line arguments. 215 */ 216 if (argv[0]) 217 msg_fatal("unexpected command-line argument: %s", argv[0]); 218 219 /* 220 * This routine runs whenever a client connects to the UNIX-domain socket 221 * dedicated to the discard mailer. What we see below is a little 222 * protocol to (1) tell the queue manager that we are ready, (2) read a 223 * request from the queue manager, and (3) report the completion status 224 * of that request. All connection-management stuff is handled by the 225 * common code in single_server.c. 226 */ 227 if ((request = deliver_request_read(client_stream)) != 0) { 228 status = deliver_message(request); 229 deliver_request_done(client_stream, request, status); 230 } 231 } 232 233 /* pre_init - pre-jail initialization */ 234 235 static void pre_init(char *unused_name, char **unused_argv) 236 { 237 flush_init(); 238 } 239 240 MAIL_VERSION_STAMP_DECLARE; 241 242 /* main - pass control to the single-threaded skeleton */ 243 244 int main(int argc, char **argv) 245 { 246 247 /* 248 * Fingerprint executables and core dumps. 249 */ 250 MAIL_VERSION_STAMP_ALLOCATE; 251 252 single_server_main(argc, argv, discard_service, 253 CA_MAIL_SERVER_PRE_INIT(pre_init), 254 0); 255 } 256