1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
|
<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html> <head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<title> Postfix manual - pipe(8) </title>
</head> <body> <pre>
PIPE(8) PIPE(8)
<b>NAME</b>
pipe - Postfix delivery to external command
<b>SYNOPSIS</b>
<b>pipe</b> [generic Postfix daemon options] command_attributes...
<b>DESCRIPTION</b>
The <a href="pipe.8.html"><b>pipe</b>(8)</a> daemon processes requests from the Postfix
queue manager to deliver messages to external commands.
This program expects to be run from the <a href="master.8.html"><b>master</b>(8)</a> process
manager.
Message attributes such as sender address, recipient
address and next-hop host name can be specified as com-
mand-line macros that are expanded before the external
command is executed.
The <a href="pipe.8.html"><b>pipe</b>(8)</a> daemon updates queue files and marks recipi-
ents 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 <a href="bounce.8.html"><b>bounce</b>(8)</a>, <a href="defer.8.html"><b>defer</b>(8)</a> or
<a href="trace.8.html"><b>trace</b>(8)</a> daemon as appropriate.
<b>SINGLE-RECIPIENT DELIVERY</b>
Some external commands cannot handle more than one recipi-
ent per delivery request. Examples of such transports are
pagers or fax machines.
To prevent Postfix from sending multiple recipients per
delivery request, specify
<i>transport</i><b>_destination_recipient_limit = 1</b>
in the Postfix <a href="postconf.5.html"><b>main.cf</b></a> file, where <i>transport</i> is the name
in the first column of the Postfix <a href="master.5.html"><b>master.cf</b></a> entry for the
pipe-based delivery transport.
<b>COMMAND ATTRIBUTE SYNTAX</b>
The external command attributes are given in the <a href="master.5.html"><b>master.cf</b></a>
file at the end of a service definition. The syntax is as
follows:
<b>chroot=</b><i>pathname</i> (optional)
Change the process root directory and working
directory to the named directory. This happens
before switching to the privileges specified with
the <b>user</b> attribute, and before executing the
optional <b>directory=</b><i>pathname</i> directive. Delivery is
deferred in case of failure.
This feature is available as of Postfix 2.3.
<b>directory=</b><i>pathname</i> (optional)
Change to the named directory before executing the
external command. The directory must be accessible
for the user specified with the <b>user</b> attribute (see
below). The default working directory is
<b>$<a href="postconf.5.html#queue_directory">queue_directory</a></b>. Delivery is deferred in case of
failure.
This feature is available as of Postfix 2.2.
<b>eol=</b><i>string</i> (optional, default: <b>\n</b>)
The output record delimiter. Typically one would
use either <b>\r\n</b> or <b>\n</b>. The usual C-style backslash
escape sequences are recognized: <b>\a \b \f \n \r \t</b>
<b>\v \</b><i>ddd</i> (up to three octal digits) and <b>\\</b>.
<b>flags=BDFORhqu.</b>> (optional)
Optional message processing flags. By default, a
message is copied unchanged.
<b>B</b> Append a blank line at the end of each mes-
sage. This is required by some mail user
agents that recognize "<b>From</b> " lines only
when preceded by a blank line.
<b>D</b> Prepend a "<b>Delivered-To:</b> <i>recipient</i>" message
header with the envelope recipient address.
Note: for this to work, the <i>transport</i><b>_desti-</b>
<b>nation_recipient_limit</b> must be 1.
This feature is available as of Postfix 2.0.
<b>F</b> Prepend a "<b>From</b> <i>sender time</i><b>_</b><i>stamp</i>" envelope
header to the message content. This is
expected by, for example, <b>UUCP</b> software.
<b>O</b> Prepend an "<b>X-Original-To:</b> <i>recipient</i>" mes-
sage header with the recipient address as
given to Postfix. Note: for this to work,
the <i>transport</i><b>_destination_recipient_limit</b>
must be 1.
This feature is available as of Postfix 2.0.
<b>R</b> Prepend a <b>Return-Path:</b> message header with
the envelope sender address.
<b>h</b> Fold the command-line <b>$recipient</b> domain name
and <b>$nexthop</b> host name to lower case. This
is recommended for delivery via <b>UUCP</b>.
<b>q</b> Quote white space and other special charac-
ters in the command-line <b>$sender</b> and <b>$recip-</b>
<b>ient</b> address localparts (text to the left of
the right-most <b>@</b> character), according to an
8-bit transparent version of <a href="http://www.faqs.org/rfcs/rfc822.html">RFC 822</a>. This
is recommended for delivery via <b>UUCP</b> or
<b>BSMTP</b>.
The result is compatible with the address
parsing of command-line recipients by the
Postfix <a href="sendmail.1.html"><b>sendmail</b>(1)</a> mail submission command.
The <b>q</b> flag affects only entire addresses,
not the partial address information from the
<b>$user</b>, <b>$extension</b> or <b>$mailbox</b> command-line
macros.
<b>u</b> Fold the command-line <b>$recipient</b> address
localpart (text to the left of the right-
most <b>@</b> character) to lower case. This is
recommended for delivery via <b>UUCP</b>.
<b>.</b> Prepend "<b>.</b>" to lines starting with "<b>.</b>". This
is needed by, for example, <b>BSMTP</b> software.
> Prepend ">" to lines starting with "<b>From</b> ".
This is expected by, for example, <b>UUCP</b> soft-
ware.
<b>null_sender</b>=<i>replacement</i> (default: MAILER-DAEMON)
Replace the null sender address, which is typically
used for delivery status notifications, with the
specified text when expanding the <b>$sender</b> command-
line macro, and when generating a From_ or Return-
Path: message header.
If the null sender replacement text is a non-empty
string then it is affected by the <b>q</b> flag for
address quoting in command-line arguments.
The null sender replacement text may be empty; this
form is recommended for content filters that feed
mail back into Postfix. The empty sender address is
not affected by the <b>q</b> flag for address quoting in
command-line arguments.
Caution: a null sender address is easily mis-parsed
by naive software. For example, when the <a href="pipe.8.html"><b>pipe</b>(8)</a>
daemon executes a command such as:
command -f$sender -- $recipient (<i>bad</i>)
the command will mis-parse the -f option value when
the sender address is a null string. For correct
parsing, specify <b>$sender</b> as an argument by itself:
command -f $sender -- $recipient (<i>good</i>)
This feature is available with Postfix 2.3 and
later.
<b>size</b>=<i>size</i><b>_</b><i>limit</i> (optional)
Messages greater in size than this limit (in bytes)
will be returned to the sender as undeliverable.
<b>user</b>=<i>username</i> (required)
<b>user</b>=<i>username</i>:<i>groupname</i>
Execute the external command with the rights of the
specified <i>username</i>. The software refuses to exe-
cute commands with root privileges, or with the
privileges of the mail system owner. If <i>groupname</i>
is specified, the corresponding group ID is used
instead of the group ID of <i>username</i>.
<b>argv</b>=<i>command</i>... (required)
The command to be executed. This must be specified
as the last command attribute. The command is exe-
cuted directly, i.e. without interpretation of
shell meta characters by a shell command inter-
preter.
In the command argument vector, the following
macros are recognized and replaced with correspond-
ing information from the Postfix queue manager
delivery request.
In addition to the form ${<i>name</i>}, the forms $<i>name</i>
and $(<i>name</i>) are also recognized. Specify <b>$$</b> where
a single <b>$</b> is wanted.
<b>${client_address</b>}
This macro expands to the remote client net-
work address.
This is available in Postfix 2.2 and later.
<b>${client_helo</b>}
This macro expands to the remote client HELO
command parameter.
This is available in Postfix 2.2 and later.
<b>${client_hostname</b>}
This macro expands to the remote client
hostname.
This is available in Postfix 2.2 and later.
<b>${client_protocol</b>}
This macro expands to the remote client pro-
tocol.
This is available in Postfix 2.2 and later.
<b>${extension</b>}
This macro expands to the extension part of
a recipient address. For example, with an
address <i>user+foo@domain</i> the extension is
<i>foo</i>.
A command-line argument that contains
<b>${extension</b>} expands into as many command-
line arguments as there are recipients.
This information is modified by the <b>u</b> flag
for case folding.
<b>${mailbox</b>}
This macro expands to the complete local
part of a recipient address. For example,
with an address <i>user+foo@domain</i> the mailbox
is <i>user+foo</i>.
A command-line argument that contains
<b>${mailbox</b>} expands to as many command-line
arguments as there are recipients.
This information is modified by the <b>u</b> flag
for case folding.
<b>${nexthop</b>}
This macro expands to the next-hop hostname.
This information is modified by the <b>h</b> flag
for case folding.
<b>${recipient</b>}
This macro expands to the complete recipient
address.
A command-line argument that contains
<b>${recipient</b>} expands to as many command-line
arguments as there are recipients.
This information is modified by the <b>hqu</b>
flags for quoting and case folding.
<b>${sasl_method</b>}
This macro expands to the SASL authentica-
tion mechanism used during the reception of
the message. An empty string is passed if
the message has been received without SASL
authentication.
This is available in Postfix 2.2 and later.
<b>${sasl_sender</b>}
This macro expands to the SASL sender name
(i.e. the original submitter as per RFC
2554) used during the reception of the mes-
sage.
This is available in Postfix 2.2 and later.
<b>${sasl_username</b>}
This macro expands to the SASL user name
used during the reception of the message. An
empty string is passed if the message has
been received without SASL authentication.
This is available in Postfix 2.2 and later.
<b>${sender</b>}
This macro expands to the envelope sender
address. By default, the null sender address
expands to MAILER-DAEMON; this can be
changed with the <b>null_sender</b> attribute, as
described above.
This information is modified by the <b>q</b> flag
for quoting.
<b>${size</b>}
This macro expands to Postfix's idea of the
message size, which is an approximation of
the size of the message as delivered.
<b>${user</b>}
This macro expands to the username part of a
recipient address. For example, with an
address <i>user+foo@domain</i> the username part is
<i>user</i>.
A command-line argument that contains
<b>${user</b>} expands into as many command-line
arguments as there are recipients.
This information is modified by the <b>u</b> flag
for case folding.
<b>STANDARDS</b>
<a href="http://www.faqs.org/rfcs/rfc3463.html">RFC 3463</a> (Enhanced status codes)
<b>DIAGNOSTICS</b>
Command exit status codes are expected to follow the con-
ventions defined in <<b>sysexits.h</b>>. Exit status 0 means
normal successful completion.
Postfix version 2.3 and later support <a href="http://www.faqs.org/rfcs/rfc3463.html">RFC 3463</a>-style
enhanced status codes. If a command terminates with a
non-zero exit status, and the command output begins with
an enhanced status code, this status code takes precedence
over the non-zero exit status.
Problems and transactions are logged to <b>syslogd</b>(8). Cor-
rupted message files are marked so that the queue manager
can move them to the <b>corrupt</b> queue for further inspection.
<b>SECURITY</b>
This program needs a dual personality 1) to access the
private Postfix queue and IPC mechanisms, and 2) to exe-
cute external commands as the specified user. It is there-
fore security sensitive.
<b>CONFIGURATION PARAMETERS</b>
Changes to <a href="postconf.5.html"><b>main.cf</b></a> are picked up automatically as <a href="pipe.8.html"><b>pipe</b>(8)</a>
processes run for only a limited amount of time. Use the
command "<b>postfix reload</b>" to speed up a change.
The text below provides only a parameter summary. See
<a href="postconf.5.html"><b>postconf</b>(5)</a> for more details including examples.
<b>RESOURCE AND RATE CONTROLS</b>
In the text below, <i>transport</i> is the first field in a <b>mas-</b>
<b>ter.cf</b> entry.
<i>transport</i><b>_destination_concurrency_limit ($<a href="postconf.5.html#default_destination_concurrency_limit">default_destina</a>-</b>
<b><a href="postconf.5.html#default_destination_concurrency_limit">tion_concurrency_limit</a>)</b>
Limit the number of parallel deliveries to the same
destination, for delivery via the named <i>transport</i>.
The limit is enforced by the Postfix queue manager.
<i>transport</i><b>_destination_recipient_limit ($<a href="postconf.5.html#default_destination_recipient_limit">default_destina</a>-</b>
<b><a href="postconf.5.html#default_destination_recipient_limit">tion_recipient_limit</a>)</b>
Limit the number of recipients per message deliv-
ery, for delivery via the named <i>transport</i>. The
limit is enforced by the Postfix queue manager.
<i>transport</i><b>_time_limit ($<a href="postconf.5.html#command_time_limit">command_time_limit</a>)</b>
Limit the time for delivery to external command,
for delivery via the named <i>transport</i>. The limit is
enforced by the pipe delivery agent.
<b>MISCELLANEOUS CONTROLS</b>
<b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
The default location of the Postfix <a href="postconf.5.html">main.cf</a> and
<a href="master.5.html">master.cf</a> configuration files.
<b><a href="postconf.5.html#daemon_timeout">daemon_timeout</a> (18000s)</b>
How much time a Postfix daemon process may take to
handle a request before it is terminated by a
built-in watchdog timer.
<b><a href="postconf.5.html#delay_logging_resolution_limit">delay_logging_resolution_limit</a> (2)</b>
The maximal number of digits after the decimal
point when logging sub-second delay values.
<b><a href="postconf.5.html#export_environment">export_environment</a> (see 'postconf -d' output)</b>
The list of environment variables that a Postfix
process will export to non-Postfix processes.
<b><a href="postconf.5.html#ipc_timeout">ipc_timeout</a> (3600s)</b>
The time limit for sending or receiving information
over an internal communication channel.
<b><a href="postconf.5.html#mail_owner">mail_owner</a> (postfix)</b>
The UNIX system account that owns the Postfix queue
and most Postfix daemon processes.
<b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
The maximum amount of time that an idle Postfix
daemon process waits for the next service request
before exiting.
<b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
The maximal number of connection requests before a
Postfix daemon process terminates.
<b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
The process ID of a Postfix command or daemon
process.
<b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
The process name of a Postfix command or daemon
process.
<b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
The location of the Postfix top-level queue direc-
tory.
<b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> (empty)</b>
The separator between user names and address exten-
sions (user+foo).
<b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
The syslog facility of Postfix logging.
<b><a href="postconf.5.html#syslog_name">syslog_name</a> (postfix)</b>
The mail system name that is prepended to the
process name in syslog records, so that "smtpd"
becomes, for example, "postfix/smtpd".
<b>SEE ALSO</b>
<a href="qmgr.8.html">qmgr(8)</a>, queue manager
<a href="bounce.8.html">bounce(8)</a>, delivery status reports
<a href="postconf.5.html">postconf(5)</a>, configuration parameters
<a href="master.5.html">master(5)</a>, generic daemon options
<a href="master.8.html">master(8)</a>, process manager
syslogd(8), system logging
<b>LICENSE</b>
The Secure Mailer license must be distributed with this
software.
<b>AUTHOR(S)</b>
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
PIPE(8)
</pre> </body> </html>
|
