1 /*++
2 /* NAME
3 /* discard 8
4 /* SUMMARY
5 /* Postfix discard mail delivery agent
6 /* SYNOPSIS
7 /* \fBdiscard\fR [generic Postfix daemon options]
8 /* DESCRIPTION
9 /* The Postfix \fBdiscard\fR(8) delivery agent processes
10 /* delivery requests from
11 /* the queue manager. Each request specifies a queue file, a sender
12 /* address, a next-hop destination that is treated as the reason for
13 /* discarding the mail, and recipient information.
14 /* The reason may be prefixed with an RFC 3463-compatible detail code.
15 /* This program expects to be run from the \fBmaster\fR(8) process
16 /* manager.
17 /*
18 /* The \fBdiscard\fR(8) delivery agent pretends to deliver all recipients
19 /* in the delivery request, logs the "next-hop" destination
20 /* as the reason for discarding the mail, updates the
21 /* queue file, and either marks recipients as finished or informs the
22 /* queue manager that delivery should be tried again at a later time.
23 /*
24 /* Delivery status reports are sent to the \fBtrace\fR(8)
25 /* daemon as appropriate.
26 /* SECURITY
27 /* .ad
28 /* .fi
29 /* The \fBdiscard\fR(8) mailer is not security-sensitive. It does not talk
30 /* to the network, and can be run chrooted at fixed low privilege.
31 /* STANDARDS
32 /* RFC 3463 (Enhanced Status Codes)
33 /* DIAGNOSTICS
34 /* Problems and transactions are logged to \fBsyslogd\fR(8)
35 /* or \fBpostlogd\fR(8).
36 /*
37 /* Depending on the setting of the \fBnotify_classes\fR parameter,
38 /* the postmaster is notified of bounces and of other trouble.
39 /* CONFIGURATION PARAMETERS
40 /* .ad
41 /* .fi
42 /* Changes to \fBmain.cf\fR are picked up automatically as \fBdiscard\fR(8)
43 /* processes run for only a limited amount of time. Use the command
44 /* "\fBpostfix reload\fR" to speed up a change.
45 /*
46 /* The text below provides only a parameter summary. See
47 /* \fBpostconf\fR(5) for more details including examples.
48 /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
49 /* The default location of the Postfix main.cf and master.cf
50 /* configuration files.
51 /* .IP "\fBdaemon_timeout (18000s)\fR"
52 /* How much time a Postfix daemon process may take to handle a
53 /* request before it is terminated by a built-in watchdog timer.
54 /* .IP "\fBdelay_logging_resolution_limit (2)\fR"
55 /* The maximal number of digits after the decimal point when logging
56 /* sub-second delay values.
57 /* .IP "\fBdouble_bounce_sender (double-bounce)\fR"
58 /* The sender address of postmaster notifications that are generated
59 /* by the mail system.
60 /* .IP "\fBipc_timeout (3600s)\fR"
61 /* The time limit for sending or receiving information over an internal
62 /* communication channel.
63 /* .IP "\fBmax_idle (100s)\fR"
64 /* The maximum amount of time that an idle Postfix daemon process waits
65 /* for an incoming connection before terminating voluntarily.
66 /* .IP "\fBmax_use (100)\fR"
67 /* The maximal number of incoming connections that a Postfix daemon
68 /* process will service before terminating voluntarily.
69 /* .IP "\fBprocess_id (read-only)\fR"
70 /* The process ID of a Postfix command or daemon process.
71 /* .IP "\fBprocess_name (read-only)\fR"
72 /* The process name of a Postfix command or daemon process.
73 /* .IP "\fBqueue_directory (see 'postconf -d' output)\fR"
74 /* The location of the Postfix top-level queue directory.
75 /* .IP "\fBsyslog_facility (mail)\fR"
76 /* The syslog facility of Postfix logging.
77 /* .IP "\fBsyslog_name (see 'postconf -d' output)\fR"
78 /* A prefix that is prepended to the process name in syslog
79 /* records, so that, for example, "smtpd" becomes "prefix/smtpd".
80 /* .PP
81 /* Available in Postfix 3.3 and later:
82 /* .IP "\fBservice_name (read-only)\fR"
83 /* The master.cf service name of a Postfix daemon process.
84 /* SEE ALSO
85 /* qmgr(8), queue manager
86 /* bounce(8), delivery status reports
87 /* error(8), Postfix error delivery agent
88 /* postconf(5), configuration parameters
89 /* master(5), generic daemon options
90 /* master(8), process manager
91 /* postlogd(8), Postfix logging
92 /* syslogd(8), system logging
93 /* LICENSE
94 /* .ad
95 /* .fi
96 /* The Secure Mailer license must be distributed with this software.
97 /* HISTORY
98 /* This service was introduced with Postfix version 2.2.
99 /* AUTHOR(S)
100 /* Victor Duchovni
101 /* Morgan Stanley
102 /*
103 /* Based on code by:
104 /* Wietse Venema
105 /* IBM T.J. Watson Research
106 /* P.O. Box 704
107 /* Yorktown Heights, NY 10598, USA
108 /*
109 /* Wietse Venema
110 /* Google, Inc.
111 /* 111 8th Avenue
112 /* New York, NY 10011, USA
113 /*--*/
114
115 /* System library. */
116
117 #include <sys_defs.h>
118 #include <unistd.h>
119 #include <stdlib.h>
120
121 /* Utility library. */
122
123 #include <msg.h>
124 #include <vstream.h>
125
126 /* Global library. */
127
128 #include <deliver_request.h>
129 #include <mail_queue.h>
130 #include <bounce.h>
131 #include <deliver_completed.h>
132 #include <flush_clnt.h>
133 #include <sent.h>
134 #include <dsn_util.h>
135 #include <mail_version.h>
136
137 /* Single server skeleton. */
138
139 #include <mail_server.h>
140
141 /* deliver_message - deliver message with extreme prejudice */
142
deliver_message(DELIVER_REQUEST * request)143 static int deliver_message(DELIVER_REQUEST *request)
144 {
145 const char *myname = "deliver_message";
146 VSTREAM *src;
147 int result = 0;
148 int status;
149 RECIPIENT *rcpt;
150 int nrcpt;
151 DSN_SPLIT dp;
152 DSN dsn;
153
154 if (msg_verbose)
155 msg_info("deliver_message: from %s", request->sender);
156
157 /*
158 * Sanity checks.
159 */
160 if (request->nexthop[0] == 0)
161 msg_fatal("empty nexthop hostname");
162 if (request->rcpt_list.len <= 0)
163 msg_fatal("recipient count: %d", request->rcpt_list.len);
164
165 /*
166 * Open the queue file. Opening the file can fail for a variety of
167 * reasons, such as the system running out of resources. Instead of
168 * throwing away mail, we're raising a fatal error which forces the mail
169 * system to back off, and retry later.
170 */
171 src = mail_queue_open(request->queue_name, request->queue_id,
172 O_RDWR, 0);
173 if (src == 0)
174 msg_fatal("%s: open %s %s: %m", myname,
175 request->queue_name, request->queue_id);
176 if (msg_verbose)
177 msg_info("%s: file %s", myname, VSTREAM_PATH(src));
178
179 /*
180 * Discard all recipients.
181 */
182 #define BOUNCE_FLAGS(request) DEL_REQ_TRACE_FLAGS(request->flags)
183
184 dsn_split(&dp, "2.0.0", request->nexthop);
185 (void) DSN_SIMPLE(&dsn, DSN_STATUS(dp.dsn), dp.text);
186 for (nrcpt = 0; nrcpt < request->rcpt_list.len; nrcpt++) {
187 rcpt = request->rcpt_list.info + nrcpt;
188 status = sent(BOUNCE_FLAGS(request), request->queue_id,
189 &request->msg_stats, rcpt, "none", &dsn);
190 if (status == 0 && (request->flags & DEL_REQ_FLAG_SUCCESS))
191 deliver_completed(src, rcpt->offset);
192 result |= status;
193 }
194
195 /*
196 * Clean up.
197 */
198 if (vstream_fclose(src))
199 msg_warn("close %s %s: %m", request->queue_name, request->queue_id);
200
201 return (result);
202 }
203
204 /* discard_service - perform service for client */
205
discard_service(VSTREAM * client_stream,char * unused_service,char ** argv)206 static void discard_service(VSTREAM *client_stream, char *unused_service, char **argv)
207 {
208 DELIVER_REQUEST *request;
209 int status;
210
211 /*
212 * Sanity check. This service takes no command-line arguments.
213 */
214 if (argv[0])
215 msg_fatal("unexpected command-line argument: %s", argv[0]);
216
217 /*
218 * This routine runs whenever a client connects to the UNIX-domain socket
219 * dedicated to the discard mailer. What we see below is a little
220 * protocol to (1) tell the queue manager that we are ready, (2) read a
221 * request from the queue manager, and (3) report the completion status
222 * of that request. All connection-management stuff is handled by the
223 * common code in single_server.c.
224 */
225 if ((request = deliver_request_read(client_stream)) != 0) {
226 status = deliver_message(request);
227 deliver_request_done(client_stream, request, status);
228 }
229 }
230
231 /* pre_init - pre-jail initialization */
232
pre_init(char * unused_name,char ** unused_argv)233 static void pre_init(char *unused_name, char **unused_argv)
234 {
235 flush_init();
236 }
237
238 MAIL_VERSION_STAMP_DECLARE;
239
240 /* main - pass control to the single-threaded skeleton */
241
main(int argc,char ** argv)242 int main(int argc, char **argv)
243 {
244
245 /*
246 * Fingerprint executables and core dumps.
247 */
248 MAIL_VERSION_STAMP_ALLOCATE;
249
250 single_server_main(argc, argv, discard_service,
251 CA_MAIL_SERVER_PRE_INIT(pre_init),
252 0);
253 }
254