1 /* $NetBSD: error.c,v 1.3 2020/03/18 19:05:16 christos Exp $ */ 2 3 /*++ 4 /* NAME 5 /* error 8 6 /* SUMMARY 7 /* Postfix error/retry mail delivery agent 8 /* SYNOPSIS 9 /* \fBerror\fR [generic Postfix daemon options] 10 /* DESCRIPTION 11 /* The Postfix \fBerror\fR(8) delivery agent processes delivery 12 /* requests from 13 /* the queue manager. Each request specifies a queue file, a sender 14 /* address, the reason for non-delivery (specified as the 15 /* next-hop destination), and recipient information. 16 /* The reason may be prefixed with an RFC 3463-compatible detail code; 17 /* if none is specified a default 4.0.0 or 5.0.0 code is used instead. 18 /* This program expects to be run from the \fBmaster\fR(8) process 19 /* manager. 20 /* 21 /* Depending on the service name in master.cf, \fBerror\fR 22 /* or \fBretry\fR, the server bounces or defers all recipients 23 /* in the delivery request using the "next-hop" information 24 /* as the reason for non-delivery. The \fBretry\fR service name is 25 /* supported as of Postfix 2.4. 26 /* 27 /* Delivery status reports are sent to the \fBbounce\fR(8), 28 /* \fBdefer\fR(8) or \fBtrace\fR(8) daemon as appropriate. 29 /* SECURITY 30 /* .ad 31 /* .fi 32 /* The \fBerror\fR(8) mailer is not security-sensitive. It does not talk 33 /* to the network, and can be run chrooted at fixed low privilege. 34 /* STANDARDS 35 /* RFC 3463 (Enhanced Status Codes) 36 /* DIAGNOSTICS 37 /* Problems and transactions are logged to \fBsyslogd\fR(8) 38 /* or \fBpostlogd\fR(8). 39 /* 40 /* Depending on the setting of the \fBnotify_classes\fR parameter, 41 /* the postmaster is notified of bounces and of other trouble. 42 /* CONFIGURATION PARAMETERS 43 /* .ad 44 /* .fi 45 /* Changes to \fBmain.cf\fR are picked up automatically as \fBerror\fR(8) 46 /* processes run for only a limited amount of time. Use the command 47 /* "\fBpostfix reload\fR" to speed up a change. 48 /* 49 /* The text below provides only a parameter summary. See 50 /* \fBpostconf\fR(5) for more details including examples. 51 /* .IP "\fB2bounce_notice_recipient (postmaster)\fR" 52 /* The recipient of undeliverable mail that cannot be returned to 53 /* the sender. 54 /* .IP "\fBbounce_notice_recipient (postmaster)\fR" 55 /* The recipient of postmaster notifications with the message headers 56 /* of mail that Postfix did not deliver and of SMTP conversation 57 /* transcripts of mail that Postfix did not receive. 58 /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" 59 /* The default location of the Postfix main.cf and master.cf 60 /* configuration files. 61 /* .IP "\fBdaemon_timeout (18000s)\fR" 62 /* How much time a Postfix daemon process may take to handle a 63 /* request before it is terminated by a built-in watchdog timer. 64 /* .IP "\fBdelay_logging_resolution_limit (2)\fR" 65 /* The maximal number of digits after the decimal point when logging 66 /* sub-second delay values. 67 /* .IP "\fBdouble_bounce_sender (double-bounce)\fR" 68 /* The sender address of postmaster notifications that are generated 69 /* by the mail system. 70 /* .IP "\fBipc_timeout (3600s)\fR" 71 /* The time limit for sending or receiving information over an internal 72 /* communication channel. 73 /* .IP "\fBmax_idle (100s)\fR" 74 /* The maximum amount of time that an idle Postfix daemon process waits 75 /* for an incoming connection before terminating voluntarily. 76 /* .IP "\fBmax_use (100)\fR" 77 /* The maximal number of incoming connections that a Postfix daemon 78 /* process will service before terminating voluntarily. 79 /* .IP "\fBnotify_classes (resource, software)\fR" 80 /* The list of error classes that are reported to the postmaster. 81 /* .IP "\fBprocess_id (read-only)\fR" 82 /* The process ID of a Postfix command or daemon process. 83 /* .IP "\fBprocess_name (read-only)\fR" 84 /* The process name of a Postfix command or daemon process. 85 /* .IP "\fBqueue_directory (see 'postconf -d' output)\fR" 86 /* The location of the Postfix top-level queue directory. 87 /* .IP "\fBsyslog_facility (mail)\fR" 88 /* The syslog facility of Postfix logging. 89 /* .IP "\fBsyslog_name (see 'postconf -d' output)\fR" 90 /* A prefix that is prepended to the process name in syslog 91 /* records, so that, for example, "smtpd" becomes "prefix/smtpd". 92 /* .PP 93 /* Available in Postfix 3.3 and later: 94 /* .IP "\fBservice_name (read-only)\fR" 95 /* The master.cf service name of a Postfix daemon process. 96 /* SEE ALSO 97 /* qmgr(8), queue manager 98 /* bounce(8), delivery status reports 99 /* discard(8), Postfix discard delivery agent 100 /* postconf(5), configuration parameters 101 /* master(5), generic daemon options 102 /* master(8), process manager 103 /* postlogd(8), Postfix logging 104 /* syslogd(8), system logging 105 /* LICENSE 106 /* .ad 107 /* .fi 108 /* The Secure Mailer license must be distributed with this software. 109 /* AUTHOR(S) 110 /* Wietse Venema 111 /* IBM T.J. Watson Research 112 /* P.O. Box 704 113 /* Yorktown Heights, NY 10598, USA 114 /* 115 /* Wietse Venema 116 /* Google, Inc. 117 /* 111 8th Avenue 118 /* New York, NY 10011, USA 119 /*--*/ 120 121 /* System library. */ 122 123 #include <sys_defs.h> 124 #include <unistd.h> 125 #include <stdlib.h> 126 127 /* Utility library. */ 128 129 #include <msg.h> 130 #include <vstream.h> 131 132 /* Global library. */ 133 134 #include <deliver_request.h> 135 #include <mail_queue.h> 136 #include <bounce.h> 137 #include <defer.h> 138 #include <deliver_completed.h> 139 #include <flush_clnt.h> 140 #include <dsn_util.h> 141 #include <sys_exits.h> 142 #include <mail_proto.h> 143 #include <mail_version.h> 144 145 /* Single server skeleton. */ 146 147 #include <mail_server.h> 148 149 /* deliver_message - deliver message with extreme prejudice */ 150 151 static int deliver_message(DELIVER_REQUEST *request, const char *def_dsn, 152 int (*append) (int, const char *, MSG_STATS *, RECIPIENT *, 153 const char *, DSN *)) 154 { 155 const char *myname = "deliver_message"; 156 VSTREAM *src; 157 int result = 0; 158 int status; 159 RECIPIENT *rcpt; 160 int nrcpt; 161 DSN_SPLIT dp; 162 DSN dsn; 163 164 if (msg_verbose) 165 msg_info("deliver_message: from %s", request->sender); 166 167 /* 168 * Sanity checks. 169 */ 170 if (request->nexthop[0] == 0) 171 msg_fatal("empty nexthop hostname"); 172 if (request->rcpt_list.len <= 0) 173 msg_fatal("recipient count: %d", request->rcpt_list.len); 174 175 /* 176 * Open the queue file. Opening the file can fail for a variety of 177 * reasons, such as the system running out of resources. Instead of 178 * throwing away mail, we're raising a fatal error which forces the mail 179 * system to back off, and retry later. 180 */ 181 src = mail_queue_open(request->queue_name, request->queue_id, 182 O_RDWR, 0); 183 if (src == 0) 184 msg_fatal("%s: open %s %s: %m", myname, 185 request->queue_name, request->queue_id); 186 if (msg_verbose) 187 msg_info("%s: file %s", myname, VSTREAM_PATH(src)); 188 189 /* 190 * Bounce/defer/whatever all recipients. 191 */ 192 #define BOUNCE_FLAGS(request) DEL_REQ_TRACE_FLAGS(request->flags) 193 194 dsn_split(&dp, def_dsn, request->nexthop); 195 (void) DSN_SIMPLE(&dsn, DSN_STATUS(dp.dsn), dp.text); 196 for (nrcpt = 0; nrcpt < request->rcpt_list.len; nrcpt++) { 197 rcpt = request->rcpt_list.info + nrcpt; 198 status = append(BOUNCE_FLAGS(request), request->queue_id, 199 &request->msg_stats, rcpt, "none", &dsn); 200 if (status == 0) 201 deliver_completed(src, rcpt->offset); 202 result |= status; 203 } 204 205 /* 206 * Clean up. 207 */ 208 if (vstream_fclose(src)) 209 msg_warn("close %s %s: %m", request->queue_name, request->queue_id); 210 211 return (result); 212 } 213 214 /* error_service - perform service for client */ 215 216 static void error_service(VSTREAM *client_stream, char *service, char **argv) 217 { 218 DELIVER_REQUEST *request; 219 int status; 220 221 /* 222 * Sanity check. This service takes no command-line arguments. 223 */ 224 if (argv[0]) 225 msg_fatal("unexpected command-line argument: %s", argv[0]); 226 227 /* 228 * This routine runs whenever a client connects to the UNIX-domain socket 229 * dedicated to the error mailer. What we see below is a little protocol 230 * to (1) tell the queue manager that we are ready, (2) read a request 231 * from the queue manager, and (3) report the completion status of that 232 * request. All connection-management stuff is handled by the common code 233 * in single_server.c. 234 */ 235 if ((request = deliver_request_read(client_stream)) != 0) { 236 if (strcmp(service, MAIL_SERVICE_ERROR) == 0) 237 status = deliver_message(request, "5.0.0", bounce_append); 238 else if (strcmp(service, MAIL_SERVICE_RETRY) == 0) 239 status = deliver_message(request, "4.0.0", defer_append); 240 else 241 msg_fatal("bad error service name: %s", service); 242 deliver_request_done(client_stream, request, status); 243 } 244 } 245 246 /* pre_init - pre-jail initialization */ 247 248 static void pre_init(char *unused_name, char **unused_argv) 249 { 250 flush_init(); 251 } 252 253 MAIL_VERSION_STAMP_DECLARE; 254 255 /* main - pass control to the single-threaded skeleton */ 256 257 int main(int argc, char **argv) 258 { 259 260 /* 261 * Fingerprint executables and core dumps. 262 */ 263 MAIL_VERSION_STAMP_ALLOCATE; 264 265 single_server_main(argc, argv, error_service, 266 CA_MAIL_SERVER_PRE_INIT(pre_init), 267 0); 268 } 269