1 /*++
2 /* NAME
3 /* postscreen 8
4 /* SUMMARY
5 /* Postfix zombie blocker
6 /* SYNOPSIS
7 /* \fBpostscreen\fR [generic Postfix daemon options]
8 /* DESCRIPTION
9 /* The Postfix \fBpostscreen\fR(8) server provides additional
10 /* protection against mail server overload. One \fBpostscreen\fR(8)
11 /* process handles multiple inbound SMTP connections, and decides
12 /* which clients may talk to a Postfix SMTP server process.
13 /* By keeping spambots away, \fBpostscreen\fR(8) leaves more
14 /* SMTP server processes available for legitimate clients, and
15 /* delays the onset of server overload conditions.
16 /*
17 /* This program should not be used on SMTP ports that receive
18 /* mail from end-user clients (MUAs). In a typical deployment,
19 /* \fBpostscreen\fR(8) handles the MX service on TCP port 25, and
20 /* \fBsmtpd\fR(8) receives mail from MUAs on the \fBsubmission\fR
21 /* service (TCP port 587) which requires client authentication.
22 /* Alternatively, a site could set up a dedicated, non-postscreen,
23 /* "port 25" server that provides \fBsubmission\fR service and
24 /* client authentication, but no MX service.
25 /*
26 /* \fBpostscreen\fR(8) maintains a temporary allowlist for
27 /* clients that have passed a number of tests. When an SMTP
28 /* client IP address is allowlisted, \fBpostscreen\fR(8) hands
29 /* off the connection immediately to a Postfix SMTP server
30 /* process. This minimizes the overhead for legitimate mail.
31 /*
32 /* By default, \fBpostscreen\fR(8) logs statistics and hands
33 /* off each connection to a Postfix SMTP server process, while
34 /* excluding clients in mynetworks from all tests (primarily,
35 /* to avoid problems with non-standard SMTP implementations
36 /* in network appliances). This default mode blocks no clients,
37 /* and is useful for non-destructive testing.
38 /*
39 /* In a typical production setting, \fBpostscreen\fR(8) is
40 /* configured to reject mail from clients that fail one or
41 /* more tests. \fBpostscreen\fR(8) logs rejected mail with the
42 /* client address, helo, sender and recipient information.
43 /*
44 /* \fBpostscreen\fR(8) is not an SMTP proxy; this is intentional.
45 /* The purpose is to keep spambots away from Postfix SMTP
46 /* server processes, while minimizing overhead for legitimate
47 /* traffic.
48 /* SECURITY
49 /* .ad
50 /* .fi
51 /* The \fBpostscreen\fR(8) server is moderately security-sensitive.
52 /* It talks to untrusted clients on the network. The process
53 /* can be run chrooted at fixed low privilege.
54 /* STANDARDS
55 /* RFC 821 (SMTP protocol)
56 /* RFC 1123 (Host requirements)
57 /* RFC 1652 (8bit-MIME transport)
58 /* RFC 1869 (SMTP service extensions)
59 /* RFC 1870 (Message Size Declaration)
60 /* RFC 1985 (ETRN command)
61 /* RFC 2034 (SMTP Enhanced Status Codes)
62 /* RFC 2821 (SMTP protocol)
63 /* Not: RFC 2920 (SMTP Pipelining)
64 /* RFC 3030 (CHUNKING without BINARYMIME)
65 /* RFC 3207 (STARTTLS command)
66 /* RFC 3461 (SMTP DSN Extension)
67 /* RFC 3463 (Enhanced Status Codes)
68 /* RFC 5321 (SMTP protocol, including multi-line 220 banners)
69 /* DIAGNOSTICS
70 /* Problems and transactions are logged to \fBsyslogd\fR(8)
71 /* or \fBpostlogd\fR(8).
72 /* BUGS
73 /* The \fBpostscreen\fR(8) built-in SMTP protocol engine
74 /* currently does not announce support for AUTH, XCLIENT or
75 /* XFORWARD.
76 /* If you need to make these services available
77 /* on port 25, then do not enable the optional "after 220
78 /* server greeting" tests.
79 /*
80 /* The optional "after 220 server greeting" tests may result in
81 /* unexpected delivery delays from senders that retry email delivery
82 /* from a different IP address. Reason: after passing these tests a
83 /* new client must disconnect, and reconnect from the same IP
84 /* address before it can deliver mail. See POSTSCREEN_README, section
85 /* "Tests after the 220 SMTP server greeting", for a discussion.
86 /* CONFIGURATION PARAMETERS
87 /* .ad
88 /* .fi
89 /* Changes to main.cf are not picked up automatically, as
90 /* \fBpostscreen\fR(8) processes may run for several hours.
91 /* Use the command "postfix reload" after a configuration
92 /* change.
93 /*
94 /* The text below provides only a parameter summary. See
95 /* \fBpostconf\fR(5) for more details including examples.
96 /*
97 /* NOTE: Some \fBpostscreen\fR(8) parameters implement
98 /* stress-dependent behavior. This is supported only when the
99 /* default parameter value is stress-dependent (that is, it
100 /* looks like ${stress?{X}:{Y}}, or it is the $\fIname\fR
101 /* of an smtpd parameter with a stress-dependent default).
102 /* Other parameters always evaluate as if the \fBstress\fR
103 /* parameter value is the empty string.
104 /* COMPATIBILITY CONTROLS
105 /* .ad
106 /* .fi
107 /* .IP "\fBpostscreen_command_filter ($smtpd_command_filter)\fR"
108 /* A mechanism to transform commands from remote SMTP clients.
109 /* .IP "\fBpostscreen_discard_ehlo_keyword_address_maps ($smtpd_discard_ehlo_keyword_address_maps)\fR"
110 /* Lookup tables, indexed by the remote SMTP client address, with
111 /* case insensitive lists of EHLO keywords (pipelining, starttls, auth,
112 /* etc.) that the \fBpostscreen\fR(8) server will not send in the EHLO response
113 /* to a remote SMTP client.
114 /* .IP "\fBpostscreen_discard_ehlo_keywords ($smtpd_discard_ehlo_keywords)\fR"
115 /* A case insensitive list of EHLO keywords (pipelining, starttls,
116 /* auth, etc.) that the \fBpostscreen\fR(8) server will not send in the EHLO
117 /* response to a remote SMTP client.
118 /* .PP
119 /* Available in Postfix version 3.1 and later:
120 /* .IP "\fBdns_ncache_ttl_fix_enable (no)\fR"
121 /* Enable a workaround for future libc incompatibility.
122 /* .PP
123 /* Available in Postfix version 3.4 and later:
124 /* .IP "\fBpostscreen_reject_footer_maps ($smtpd_reject_footer_maps)\fR"
125 /* Optional lookup table for information that is appended after a 4XX
126 /* or 5XX \fBpostscreen\fR(8) server response.
127 /* .PP
128 /* Available in Postfix 3.6 and later:
129 /* .IP "\fBrespectful_logging (see 'postconf -d' output)\fR"
130 /* Avoid logging that implies white is better than black.
131 /* TROUBLE SHOOTING CONTROLS
132 /* .ad
133 /* .fi
134 /* .IP "\fBpostscreen_expansion_filter (see 'postconf -d' output)\fR"
135 /* List of characters that are permitted in postscreen_reject_footer
136 /* attribute expansions.
137 /* .IP "\fBpostscreen_reject_footer ($smtpd_reject_footer)\fR"
138 /* Optional information that is appended after a 4XX or 5XX
139 /* \fBpostscreen\fR(8) server
140 /* response.
141 /* .IP "\fBsoft_bounce (no)\fR"
142 /* Safety net to keep mail queued that would otherwise be returned to
143 /* the sender.
144 /* BEFORE-POSTSCREEN PROXY AGENT
145 /* .ad
146 /* .fi
147 /* Available in Postfix version 2.10 and later:
148 /* .IP "\fBpostscreen_upstream_proxy_protocol (empty)\fR"
149 /* The name of the proxy protocol used by an optional before-postscreen
150 /* proxy agent.
151 /* .IP "\fBpostscreen_upstream_proxy_timeout (5s)\fR"
152 /* The time limit for the proxy protocol specified with the
153 /* postscreen_upstream_proxy_protocol parameter.
154 /* PERMANENT ALLOW/DENYLIST TEST
155 /* .ad
156 /* .fi
157 /* This test is executed immediately after a remote SMTP client
158 /* connects. If a client is permanently allowlisted, the client
159 /* will be handed off immediately to a Postfix SMTP server
160 /* process.
161 /* .IP "\fBpostscreen_access_list (permit_mynetworks)\fR"
162 /* Permanent allow/denylist for remote SMTP client IP addresses.
163 /* .IP "\fBpostscreen_blacklist_action (ignore)\fR"
164 /* Renamed to postscreen_denylist_action in Postfix 3.6.
165 /* MAIL EXCHANGER POLICY TESTS
166 /* .ad
167 /* .fi
168 /* When \fBpostscreen\fR(8) is configured to monitor all primary
169 /* and backup MX addresses, it can refuse to allowlist clients
170 /* that connect to a backup MX address only. For small sites,
171 /* this requires configuring primary and backup MX addresses
172 /* on the same MTA. Larger sites would have to share the
173 /* \fBpostscreen\fR(8) cache between primary and backup MTAs,
174 /* which would introduce a common point of failure.
175 /* .IP "\fBpostscreen_whitelist_interfaces (static:all)\fR"
176 /* Renamed to postscreen_allowlist_interfaces in Postfix 3.6.
177 /* BEFORE 220 GREETING TESTS
178 /* .ad
179 /* .fi
180 /* These tests are executed before the remote SMTP client
181 /* receives the "220 servername" greeting. If no tests remain
182 /* after the successful completion of this phase, the client
183 /* will be handed off immediately to a Postfix SMTP server
184 /* process.
185 /* .IP "\fBdnsblog_service_name (dnsblog)\fR"
186 /* The name of the \fBdnsblog\fR(8) service entry in master.cf.
187 /* .IP "\fBpostscreen_dnsbl_action (ignore)\fR"
188 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client's combined
189 /* DNSBL score is equal to or greater than a threshold (as defined
190 /* with the postscreen_dnsbl_sites and postscreen_dnsbl_threshold
191 /* parameters).
192 /* .IP "\fBpostscreen_dnsbl_reply_map (empty)\fR"
193 /* A mapping from actual DNSBL domain name which includes a secret
194 /* password, to the DNSBL domain name that postscreen will reply with
195 /* when it rejects mail.
196 /* .IP "\fBpostscreen_dnsbl_sites (empty)\fR"
197 /* Optional list of DNS allow/denylist domains, filters and weight
198 /* factors.
199 /* .IP "\fBpostscreen_dnsbl_threshold (1)\fR"
200 /* The inclusive lower bound for blocking a remote SMTP client, based on
201 /* its combined DNSBL score as defined with the postscreen_dnsbl_sites
202 /* parameter.
203 /* .IP "\fBpostscreen_greet_action (ignore)\fR"
204 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client speaks
205 /* before its turn within the time specified with the postscreen_greet_wait
206 /* parameter.
207 /* .IP "\fBpostscreen_greet_banner ($smtpd_banner)\fR"
208 /* The \fItext\fR in the optional "220-\fItext\fR..." server
209 /* response that
210 /* \fBpostscreen\fR(8) sends ahead of the real Postfix SMTP server's "220
211 /* text..." response, in an attempt to confuse bad SMTP clients so
212 /* that they speak before their turn (pre-greet).
213 /* .IP "\fBpostscreen_greet_wait (normal: 6s, overload: 2s)\fR"
214 /* The amount of time that \fBpostscreen\fR(8) will wait for an SMTP
215 /* client to send a command before its turn, and for DNS blocklist
216 /* lookup results to arrive (default: up to 2 seconds under stress,
217 /* up to 6 seconds otherwise).
218 /* .IP "\fBsmtpd_service_name (smtpd)\fR"
219 /* The internal service that \fBpostscreen\fR(8) hands off allowed
220 /* connections to.
221 /* .PP
222 /* Available in Postfix version 2.11 and later:
223 /* .IP "\fBpostscreen_dnsbl_whitelist_threshold (0)\fR"
224 /* Renamed to postscreen_dnsbl_allowlist_threshold in Postfix 3.6.
225 /* .PP
226 /* Available in Postfix version 3.0 and later:
227 /* .IP "\fBpostscreen_dnsbl_timeout (10s)\fR"
228 /* The time limit for DNSBL or DNSWL lookups.
229 /* .PP
230 /* Available in Postfix version 3.6 and later:
231 /* .IP "\fBpostscreen_denylist_action (ignore)\fR"
232 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client is
233 /* permanently denylisted with the postscreen_access_list parameter.
234 /* .IP "\fBpostscreen_allowlist_interfaces (static:all)\fR"
235 /* A list of local \fBpostscreen\fR(8) server IP addresses where a
236 /* non-allowlisted remote SMTP client can obtain \fBpostscreen\fR(8)'s temporary
237 /* allowlist status.
238 /* .IP "\fBpostscreen_dnsbl_allowlist_threshold (0)\fR"
239 /* Allow a remote SMTP client to skip "before" and "after 220
240 /* greeting" protocol tests, based on its combined DNSBL score as
241 /* defined with the postscreen_dnsbl_sites parameter.
242 /* AFTER 220 GREETING TESTS
243 /* .ad
244 /* .fi
245 /* These tests are executed after the remote SMTP client
246 /* receives the "220 servername" greeting. If a client passes
247 /* all tests during this phase, it will receive a 4XX response
248 /* to all RCPT TO commands. After the client reconnects, it
249 /* will be allowed to talk directly to a Postfix SMTP server
250 /* process.
251 /* .IP "\fBpostscreen_bare_newline_action (ignore)\fR"
252 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client sends
253 /* a bare newline character, that is, a newline not preceded by carriage
254 /* return.
255 /* .IP "\fBpostscreen_bare_newline_enable (no)\fR"
256 /* Enable "bare newline" SMTP protocol tests in the \fBpostscreen\fR(8)
257 /* server.
258 /* .IP "\fBpostscreen_disable_vrfy_command ($disable_vrfy_command)\fR"
259 /* Disable the SMTP VRFY command in the \fBpostscreen\fR(8) daemon.
260 /* .IP "\fBpostscreen_forbidden_commands ($smtpd_forbidden_commands)\fR"
261 /* List of commands that the \fBpostscreen\fR(8) server considers in
262 /* violation of the SMTP protocol.
263 /* .IP "\fBpostscreen_helo_required ($smtpd_helo_required)\fR"
264 /* Require that a remote SMTP client sends HELO or EHLO before
265 /* commencing a MAIL transaction.
266 /* .IP "\fBpostscreen_non_smtp_command_action (drop)\fR"
267 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client sends
268 /* non-SMTP commands as specified with the postscreen_forbidden_commands
269 /* parameter.
270 /* .IP "\fBpostscreen_non_smtp_command_enable (no)\fR"
271 /* Enable "non-SMTP command" tests in the \fBpostscreen\fR(8) server.
272 /* .IP "\fBpostscreen_pipelining_action (enforce)\fR"
273 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client
274 /* sends
275 /* multiple commands instead of sending one command and waiting for
276 /* the server to respond.
277 /* .IP "\fBpostscreen_pipelining_enable (no)\fR"
278 /* Enable "pipelining" SMTP protocol tests in the \fBpostscreen\fR(8)
279 /* server.
280 /* CACHE CONTROLS
281 /* .ad
282 /* .fi
283 /* .IP "\fBpostscreen_cache_cleanup_interval (12h)\fR"
284 /* The amount of time between \fBpostscreen\fR(8) cache cleanup runs.
285 /* .IP "\fBpostscreen_cache_map (btree:$data_directory/postscreen_cache)\fR"
286 /* Persistent storage for the \fBpostscreen\fR(8) server decisions.
287 /* .IP "\fBpostscreen_cache_retention_time (7d)\fR"
288 /* The amount of time that \fBpostscreen\fR(8) will cache an expired
289 /* temporary allowlist entry before it is removed.
290 /* .IP "\fBpostscreen_bare_newline_ttl (30d)\fR"
291 /* The amount of time that \fBpostscreen\fR(8) will use the result from
292 /* a successful "bare newline" SMTP protocol test.
293 /* .IP "\fBpostscreen_dnsbl_max_ttl (${postscreen_dnsbl_ttl?{$postscreen_dnsbl_ttl}:{1}}h)\fR"
294 /* The maximum amount of time that \fBpostscreen\fR(8) will use the
295 /* result from a successful DNS-based reputation test before a
296 /* client IP address is required to pass that test again.
297 /* .IP "\fBpostscreen_dnsbl_min_ttl (60s)\fR"
298 /* The minimum amount of time that \fBpostscreen\fR(8) will use the
299 /* result from a successful DNS-based reputation test before a
300 /* client IP address is required to pass that test again.
301 /* .IP "\fBpostscreen_greet_ttl (1d)\fR"
302 /* The amount of time that \fBpostscreen\fR(8) will use the result from
303 /* a successful PREGREET test.
304 /* .IP "\fBpostscreen_non_smtp_command_ttl (30d)\fR"
305 /* The amount of time that \fBpostscreen\fR(8) will use the result from
306 /* a successful "non_smtp_command" SMTP protocol test.
307 /* .IP "\fBpostscreen_pipelining_ttl (30d)\fR"
308 /* The amount of time that \fBpostscreen\fR(8) will use the result from
309 /* a successful "pipelining" SMTP protocol test.
310 /* RESOURCE CONTROLS
311 /* .ad
312 /* .fi
313 /* .IP "\fBline_length_limit (2048)\fR"
314 /* Upon input, long lines are chopped up into pieces of at most
315 /* this length; upon delivery, long lines are reconstructed.
316 /* .IP "\fBpostscreen_client_connection_count_limit ($smtpd_client_connection_count_limit)\fR"
317 /* How many simultaneous connections any remote SMTP client is
318 /* allowed to have
319 /* with the \fBpostscreen\fR(8) daemon.
320 /* .IP "\fBpostscreen_command_count_limit (20)\fR"
321 /* The limit on the total number of commands per SMTP session for
322 /* \fBpostscreen\fR(8)'s built-in SMTP protocol engine.
323 /* .IP "\fBpostscreen_command_time_limit (normal: 300s, overload: 10s)\fR"
324 /* The time limit to read an entire command line with \fBpostscreen\fR(8)'s
325 /* built-in SMTP protocol engine.
326 /* .IP "\fBpostscreen_post_queue_limit ($default_process_limit)\fR"
327 /* The number of clients that can be waiting for service from a
328 /* real Postfix SMTP server process.
329 /* .IP "\fBpostscreen_pre_queue_limit ($default_process_limit)\fR"
330 /* The number of non-allowlisted clients that can be waiting for
331 /* a decision whether they will receive service from a real Postfix
332 /* SMTP server
333 /* process.
334 /* .IP "\fBpostscreen_watchdog_timeout (10s)\fR"
335 /* How much time a \fBpostscreen\fR(8) process may take to respond to
336 /* a remote SMTP client command or to perform a cache operation before it
337 /* is terminated by a built-in watchdog timer.
338 /* STARTTLS CONTROLS
339 /* .ad
340 /* .fi
341 /* .IP "\fBpostscreen_tls_security_level ($smtpd_tls_security_level)\fR"
342 /* The SMTP TLS security level for the \fBpostscreen\fR(8) server; when
343 /* a non-empty value is specified, this overrides the obsolete parameters
344 /* postscreen_use_tls and postscreen_enforce_tls.
345 /* .IP "\fBtlsproxy_service_name (tlsproxy)\fR"
346 /* The name of the \fBtlsproxy\fR(8) service entry in master.cf.
347 /* OBSOLETE STARTTLS SUPPORT CONTROLS
348 /* .ad
349 /* .fi
350 /* These parameters are supported for compatibility with
351 /* \fBsmtpd\fR(8) legacy parameters.
352 /* .IP "\fBpostscreen_use_tls ($smtpd_use_tls)\fR"
353 /* Opportunistic TLS: announce STARTTLS support to remote SMTP clients,
354 /* but do not require that clients use TLS encryption.
355 /* .IP "\fBpostscreen_enforce_tls ($smtpd_enforce_tls)\fR"
356 /* Mandatory TLS: announce STARTTLS support to remote SMTP clients, and
357 /* require that clients use TLS encryption.
358 /* MISCELLANEOUS CONTROLS
359 /* .ad
360 /* .fi
361 /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
362 /* The default location of the Postfix main.cf and master.cf
363 /* configuration files.
364 /* .IP "\fBdelay_logging_resolution_limit (2)\fR"
365 /* The maximal number of digits after the decimal point when logging
366 /* sub-second delay values.
367 /* .IP "\fBcommand_directory (see 'postconf -d' output)\fR"
368 /* The location of all postfix administrative commands.
369 /* .IP "\fBmax_idle (100s)\fR"
370 /* The maximum amount of time that an idle Postfix daemon process waits
371 /* for an incoming connection before terminating voluntarily.
372 /* .IP "\fBprocess_id (read-only)\fR"
373 /* The process ID of a Postfix command or daemon process.
374 /* .IP "\fBprocess_name (read-only)\fR"
375 /* The process name of a Postfix command or daemon process.
376 /* .IP "\fBsyslog_facility (mail)\fR"
377 /* The syslog facility of Postfix logging.
378 /* .IP "\fBsyslog_name (see 'postconf -d' output)\fR"
379 /* A prefix that is prepended to the process name in syslog
380 /* records, so that, for example, "smtpd" becomes "prefix/smtpd".
381 /* .PP
382 /* Available in Postfix 3.3 and later:
383 /* .IP "\fBservice_name (read-only)\fR"
384 /* The master.cf service name of a Postfix daemon process.
385 /* .PP
386 /* Available in Postfix 3.5 and later:
387 /* .IP "\fBinfo_log_address_format (external)\fR"
388 /* The email address form that will be used in non-debug logging
389 /* (info, warning, etc.).
390 /* SEE ALSO
391 /* smtpd(8), Postfix SMTP server
392 /* tlsproxy(8), Postfix TLS proxy server
393 /* dnsblog(8), DNS allow/denylist logger
394 /* postlogd(8), Postfix logging
395 /* syslogd(8), system logging
396 /* README FILES
397 /* .ad
398 /* .fi
399 /* Use "\fBpostconf readme_directory\fR" or "\fBpostconf
400 /* html_directory\fR" to locate this information.
401 /* .nf
402 /* .na
403 /* POSTSCREEN_README, Postfix Postscreen Howto
404 /* LICENSE
405 /* .ad
406 /* .fi
407 /* The Secure Mailer license must be distributed with this software.
408 /* HISTORY
409 /* .ad
410 /* .fi
411 /* This service was introduced with Postfix version 2.8.
412 /*
413 /* Many ideas in \fBpostscreen\fR(8) were explored in earlier
414 /* work by Michael Tokarev, in OpenBSD spamd, and in MailChannels
415 /* Traffic Control.
416 /* AUTHOR(S)
417 /* Wietse Venema
418 /* IBM T.J. Watson Research
419 /* P.O. Box 704
420 /* Yorktown Heights, NY 10598, USA
421 /*
422 /* Wietse Venema
423 /* Google, Inc.
424 /* 111 8th Avenue
425 /* New York, NY 10011, USA
426 /*--*/
427
428 /* System library. */
429
430 #include <sys_defs.h>
431 #include <sys/stat.h>
432 #include <stdlib.h>
433
434 /* Utility library. */
435
436 #include <msg.h>
437 #include <mymalloc.h>
438 #include <events.h>
439 #include <myaddrinfo.h>
440 #include <dict_cache.h>
441 #include <set_eugid.h>
442 #include <vstream.h>
443 #include <name_code.h>
444 #include <inet_proto.h>
445
446 /* Global library. */
447
448 #include <mail_conf.h>
449 #include <mail_params.h>
450 #include <mail_version.h>
451 #include <mail_proto.h>
452 #include <data_redirect.h>
453 #include <string_list.h>
454
455 /* Master server protocols. */
456
457 #include <mail_server.h>
458
459 /* Application-specific. */
460
461 #include <postscreen.h>
462
463 /*
464 * Configuration parameters.
465 */
466 char *var_smtpd_service;
467 char *var_smtpd_banner;
468 bool var_disable_vrfy_cmd;
469 bool var_helo_required;
470
471 char *var_smtpd_cmd_filter;
472 char *var_psc_cmd_filter;
473
474 char *var_smtpd_forbid_cmds;
475 char *var_psc_forbid_cmds;
476
477 char *var_smtpd_ehlo_dis_words;
478 char *var_smtpd_ehlo_dis_maps;
479 char *var_psc_ehlo_dis_words;
480 char *var_psc_ehlo_dis_maps;
481
482 char *var_smtpd_tls_level;
483 bool var_smtpd_use_tls;
484 bool var_smtpd_enforce_tls;
485 char *var_psc_tls_level;
486 bool var_psc_use_tls;
487 bool var_psc_enforce_tls;
488
489 bool var_psc_disable_vrfy;
490 bool var_psc_helo_required;
491
492 char *var_psc_cache_map;
493 int var_psc_cache_scan;
494 int var_psc_cache_ret;
495 int var_psc_post_queue_limit;
496 int var_psc_pre_queue_limit;
497 int var_psc_watchdog;
498
499 char *var_psc_acl;
500 char *var_psc_dnlist_action;
501
502 char *var_psc_greet_ttl;
503 int var_psc_greet_wait;
504
505 char *var_psc_pregr_banner;
506 char *var_psc_pregr_action;
507 int var_psc_pregr_ttl;
508
509 char *var_psc_dnsbl_sites;
510 char *var_psc_dnsbl_reply;
511 int var_psc_dnsbl_thresh;
512 int var_psc_dnsbl_althresh;
513 char *var_psc_dnsbl_action;
514 int var_psc_dnsbl_min_ttl;
515 int var_psc_dnsbl_max_ttl;
516 int var_psc_dnsbl_tmout;
517
518 bool var_psc_pipel_enable;
519 char *var_psc_pipel_action;
520 int var_psc_pipel_ttl;
521
522 bool var_psc_nsmtp_enable;
523 char *var_psc_nsmtp_action;
524 int var_psc_nsmtp_ttl;
525
526 bool var_psc_barlf_enable;
527 char *var_psc_barlf_action;
528 int var_psc_barlf_ttl;
529
530 int var_psc_cmd_count;
531 int var_psc_cmd_time;
532
533 char *var_dnsblog_service;
534 char *var_tlsproxy_service;
535
536 char *var_smtpd_rej_footer;
537 char *var_psc_rej_footer;
538 char *var_psc_rej_ftr_maps;
539
540 int var_smtpd_cconn_limit;
541 int var_psc_cconn_limit;
542
543 char *var_smtpd_exp_filter;
544 char *var_psc_exp_filter;
545
546 char *var_psc_allist_if;
547 char *var_psc_uproxy_proto;
548 int var_psc_uproxy_tmout;
549
550 /*
551 * Global variables.
552 */
553 int psc_check_queue_length; /* connections being checked */
554 int psc_post_queue_length; /* being sent to real SMTPD */
555 DICT_CACHE *psc_cache_map; /* cache table handle */
556 VSTRING *psc_temp; /* scratchpad */
557 char *psc_smtpd_service_name; /* path to real SMTPD */
558 int psc_pregr_action; /* PSC_ACT_DROP/ENFORCE/etc */
559 int psc_dnsbl_action; /* PSC_ACT_DROP/ENFORCE/etc */
560 int psc_pipel_action; /* PSC_ACT_DROP/ENFORCE/etc */
561 int psc_nsmtp_action; /* PSC_ACT_DROP/ENFORCE/etc */
562 int psc_barlf_action; /* PSC_ACT_DROP/ENFORCE/etc */
563 int psc_min_ttl; /* Update with new tests! */
564 STRING_LIST *psc_forbid_cmds; /* CONNECT GET POST */
565 int psc_stress_greet_wait; /* stressed greet wait */
566 int psc_normal_greet_wait; /* stressed greet wait */
567 int psc_stress_cmd_time_limit; /* stressed command limit */
568 int psc_normal_cmd_time_limit; /* normal command time limit */
569 int psc_stress; /* stress level */
570 int psc_lowat_check_queue_length; /* stress low-water mark */
571 int psc_hiwat_check_queue_length; /* stress high-water mark */
572 DICT *psc_dnsbl_reply; /* DNSBL name mapper */
573 HTABLE *psc_client_concurrency; /* per-client concurrency */
574
575 /*
576 * Local variables and functions.
577 */
578 static ARGV *psc_acl; /* permanent allow/denylist */
579 static int psc_dnlist_action; /* PSC_ACT_DROP/ENFORCE/etc */
580 static ADDR_MATCH_LIST *psc_allist_if; /* allowlist interfaces */
581
582 static void psc_endpt_lookup_done(int, VSTREAM *,
583 MAI_HOSTADDR_STR *, MAI_SERVPORT_STR *,
584 MAI_HOSTADDR_STR *, MAI_SERVPORT_STR *);
585
586 /* psc_dump - dump some statistics before exit */
587
psc_dump(char * unused_service,char ** unused_argv)588 static void psc_dump(char *unused_service, char **unused_argv)
589 {
590
591 /*
592 * Dump preliminary cache cleanup statistics when the process commits
593 * suicide while a cache cleanup run is in progress. We can't currently
594 * distinguish between "postfix reload" (we should restart) or "maximal
595 * idle time reached" (we could finish the cache cleanup first).
596 */
597 if (psc_cache_map) {
598 dict_cache_close(psc_cache_map);
599 psc_cache_map = 0;
600 }
601 }
602
603 /* psc_drain - delayed exit after "postfix reload" */
604
psc_drain(char * unused_service,char ** unused_argv)605 static void psc_drain(char *unused_service, char **unused_argv)
606 {
607 int count;
608
609 /*
610 * After "postfix reload", complete work-in-progress in the background,
611 * instead of dropping already-accepted connections on the floor.
612 *
613 * Unfortunately we must close all writable tables, so we can't store or
614 * look up reputation information. The reason is that we don't have any
615 * multi-writer safety guarantees. We also can't use the single-writer
616 * proxywrite service, because its latency guarantees are too weak.
617 *
618 * All error retry counts shall be limited. Instead of blocking here, we
619 * could retry failed fork() operations in the event call-back routines,
620 * but we don't need perfection. The host system is severely overloaded
621 * and service levels are already way down.
622 *
623 * XXX Some Berkeley DB versions break with close-after-fork. Every new
624 * version is an improvement over its predecessor.
625 *
626 * XXX Don't assume that it is OK to share the same LMDB lockfile descriptor
627 * between different processes.
628 */
629 if (psc_cache_map != 0 /* XXX && psc_cache_map
630 requires locking */ ) {
631 dict_cache_close(psc_cache_map);
632 psc_cache_map = 0;
633 }
634 for (count = 0; /* see below */ ; count++) {
635 if (count >= 5) {
636 msg_fatal("fork: %m");
637 } else if (event_server_drain() != 0) {
638 msg_warn("fork: %m");
639 sleep(1);
640 continue;
641 } else {
642 return;
643 }
644 }
645 }
646
647 /* psc_service - handle new client connection */
648
psc_service(VSTREAM * smtp_client_stream,char * unused_service,char ** unused_argv)649 static void psc_service(VSTREAM *smtp_client_stream,
650 char *unused_service,
651 char **unused_argv)
652 {
653
654 /*
655 * For sanity, require that at least one of INET or INET6 is enabled.
656 * Otherwise, we can't look up interface information, and we can't
657 * convert names or addresses.
658 */
659 if (inet_proto_info()->ai_family_list[0] == 0)
660 msg_fatal("all network protocols are disabled (%s = %s)",
661 VAR_INET_PROTOCOLS, var_inet_protocols);
662
663 /*
664 * This program handles all incoming connections, so it must not block.
665 * We use event-driven code for all operations that introduce latency.
666 *
667 * Note: instead of using VSTREAM-level timeouts, we enforce limits on the
668 * total amount of time to receive a complete SMTP command line.
669 */
670 non_blocking(vstream_fileno(smtp_client_stream), NON_BLOCKING);
671
672 /*
673 * Look up the remote SMTP client address and port.
674 */
675 psc_endpt_lookup(smtp_client_stream, psc_endpt_lookup_done);
676 }
677
678 /* psc_warn_compat_respectful_logging - compatibility warning */
679
psc_warn_compat_respectful_logging(PSC_STATE * state)680 static void psc_warn_compat_respectful_logging(PSC_STATE *state)
681 {
682 msg_info("using backwards-compatible default setting "
683 VAR_RESPECTFUL_LOGGING "=no for client [%s]:%s",
684 PSC_CLIENT_ADDR_PORT(state));
685 warn_compat_respectful_logging = 0;
686 }
687
688 /* psc_endpt_lookup_done - endpoint lookup completed */
689
psc_endpt_lookup_done(int endpt_status,VSTREAM * smtp_client_stream,MAI_HOSTADDR_STR * smtp_client_addr,MAI_SERVPORT_STR * smtp_client_port,MAI_HOSTADDR_STR * smtp_server_addr,MAI_SERVPORT_STR * smtp_server_port)690 static void psc_endpt_lookup_done(int endpt_status,
691 VSTREAM *smtp_client_stream,
692 MAI_HOSTADDR_STR *smtp_client_addr,
693 MAI_SERVPORT_STR *smtp_client_port,
694 MAI_HOSTADDR_STR *smtp_server_addr,
695 MAI_SERVPORT_STR *smtp_server_port)
696 {
697 const char *myname = "psc_endpt_lookup_done";
698 PSC_STATE *state;
699 const char *stamp_str;
700 int saved_flags;
701
702 /*
703 * Best effort - if this non-blocking write(2) fails, so be it.
704 */
705 if (endpt_status < 0) {
706 (void) write(vstream_fileno(smtp_client_stream),
707 "421 4.3.2 No system resources\r\n",
708 sizeof("421 4.3.2 No system resources\r\n") - 1);
709 event_server_disconnect(smtp_client_stream);
710 return;
711 }
712 if (msg_verbose > 1)
713 msg_info("%s: sq=%d cq=%d connect from [%s]:%s",
714 myname, psc_post_queue_length, psc_check_queue_length,
715 smtp_client_addr->buf, smtp_client_port->buf);
716
717 msg_info("CONNECT from [%s]:%s to [%s]:%s",
718 smtp_client_addr->buf, smtp_client_port->buf,
719 smtp_server_addr->buf, smtp_server_port->buf);
720
721 /*
722 * Bundle up all the loose session pieces. This zeroes all flags and time
723 * stamps.
724 */
725 state = psc_new_session_state(smtp_client_stream, smtp_client_addr->buf,
726 smtp_client_port->buf,
727 smtp_server_addr->buf,
728 smtp_server_port->buf);
729
730 /*
731 * Reply with 421 when the client has too many open connections.
732 */
733 if (var_psc_cconn_limit > 0
734 && state->client_info->concurrency > var_psc_cconn_limit) {
735 msg_info("NOQUEUE: reject: CONNECT from [%s]:%s: too many connections",
736 state->smtp_client_addr, state->smtp_client_port);
737 PSC_DROP_SESSION_STATE(state,
738 "421 4.7.0 Error: too many connections\r\n");
739 return;
740 }
741
742 /*
743 * Reply with 421 when we can't forward more connections.
744 */
745 if (var_psc_post_queue_limit > 0
746 && psc_post_queue_length >= var_psc_post_queue_limit) {
747 msg_info("NOQUEUE: reject: CONNECT from [%s]:%s: all server ports busy",
748 state->smtp_client_addr, state->smtp_client_port);
749 PSC_DROP_SESSION_STATE(state,
750 "421 4.3.2 All server ports are busy\r\n");
751 return;
752 }
753
754 /*
755 * The permanent allow/denylist has highest precedence.
756 */
757 if (psc_acl != 0) {
758 switch (psc_acl_eval(state, psc_acl, VAR_PSC_ACL)) {
759
760 /*
761 * Permanently denylisted.
762 */
763 case PSC_ACL_ACT_DENYLIST:
764 msg_info("%sLISTED [%s]:%s",
765 var_respectful_logging ? "DENY" : "BLACK",
766 PSC_CLIENT_ADDR_PORT(state));
767 if (warn_compat_respectful_logging)
768 psc_warn_compat_respectful_logging(state);
769 PSC_FAIL_SESSION_STATE(state, PSC_STATE_FLAG_DNLIST_FAIL);
770 switch (psc_dnlist_action) {
771 case PSC_ACT_DROP:
772 PSC_DROP_SESSION_STATE(state,
773 "521 5.3.2 Service currently unavailable\r\n");
774 return;
775 case PSC_ACT_ENFORCE:
776 PSC_ENFORCE_SESSION_STATE(state,
777 "550 5.3.2 Service currently unavailable\r\n");
778 break;
779 case PSC_ACT_IGNORE:
780 PSC_UNFAIL_SESSION_STATE(state, PSC_STATE_FLAG_DNLIST_FAIL);
781
782 /*
783 * Not: PSC_PASS_SESSION_STATE. Repeat this test the next
784 * time.
785 */
786 break;
787 default:
788 msg_panic("%s: unknown denylist action value %d",
789 myname, psc_dnlist_action);
790 }
791 break;
792
793 /*
794 * Permanently allowlisted.
795 */
796 case PSC_ACL_ACT_ALLOWLIST:
797 msg_info("%sLISTED [%s]:%s",
798 var_respectful_logging ? "ALLOW" : "WHITE",
799 PSC_CLIENT_ADDR_PORT(state));
800 if (warn_compat_respectful_logging)
801 psc_warn_compat_respectful_logging(state);
802 psc_conclude(state);
803 return;
804
805 /*
806 * Other: dunno (don't know) or error.
807 */
808 default:
809 break;
810 }
811 }
812
813 /*
814 * The temporary allowlist (i.e. the postscreen cache) has the lowest
815 * precedence. This cache contains information about the results of prior
816 * tests. Allowlist the client when all enabled test results are still
817 * valid.
818 */
819 if ((state->flags & PSC_STATE_MASK_ANY_FAIL) == 0
820 && state->client_info->concurrency == 1
821 && psc_cache_map != 0
822 && (stamp_str = psc_cache_lookup(psc_cache_map, state->smtp_client_addr)) != 0) {
823 saved_flags = state->flags;
824 psc_parse_tests(state, stamp_str, event_time());
825 state->flags |= saved_flags;
826 if (msg_verbose)
827 msg_info("%s: cached + recent flags: %s",
828 myname, psc_print_state_flags(state->flags, myname));
829 if ((state->flags & PSC_STATE_MASK_ANY_TODO_FAIL) == 0) {
830 msg_info("PASS OLD [%s]:%s", PSC_CLIENT_ADDR_PORT(state));
831 psc_conclude(state);
832 return;
833 }
834 } else if (state->client_info->concurrency > 1) {
835 saved_flags = state->flags;
836 psc_todo_tests(state, event_time());
837 state->flags |= saved_flags;
838 if (msg_verbose)
839 msg_info("%s: new + recent flags: %s",
840 myname, psc_print_state_flags(state->flags, myname));
841 } else {
842 saved_flags = state->flags;
843 psc_new_tests(state);
844 state->flags |= saved_flags;
845 if (msg_verbose)
846 msg_info("%s: new + recent flags: %s",
847 myname, psc_print_state_flags(state->flags, myname));
848 }
849
850 /*
851 * Don't allowlist clients that connect to backup MX addresses. Fail
852 * "closed" on error.
853 */
854 if (addr_match_list_match(psc_allist_if, smtp_server_addr->buf) == 0) {
855 state->flags |= (PSC_STATE_FLAG_ALLIST_FAIL | PSC_STATE_FLAG_NOFORWARD);
856 msg_info("%sLIST VETO [%s]:%s", var_respectful_logging ?
857 "ALLOW" : "WHITE", PSC_CLIENT_ADDR_PORT(state));
858 if (warn_compat_respectful_logging)
859 psc_warn_compat_respectful_logging(state);
860 }
861
862 /*
863 * Reply with 421 when we can't analyze more connections. That also means
864 * no deep protocol tests when the noforward flag is raised.
865 */
866 if (var_psc_pre_queue_limit > 0
867 && psc_check_queue_length - psc_post_queue_length
868 >= var_psc_pre_queue_limit) {
869 msg_info("reject: connect from [%s]:%s: all screening ports busy",
870 state->smtp_client_addr, state->smtp_client_port);
871 PSC_DROP_SESSION_STATE(state,
872 "421 4.3.2 All screening ports are busy\r\n");
873 return;
874 }
875
876 /*
877 * If the client has no up-to-date results for some tests, do those tests
878 * first. Otherwise, skip the tests and hand off the connection.
879 */
880 if (state->flags & PSC_STATE_MASK_EARLY_TODO)
881 psc_early_tests(state);
882 else if (state->flags & (PSC_STATE_MASK_SMTPD_TODO | PSC_STATE_FLAG_NOFORWARD))
883 psc_smtpd_tests(state);
884 else
885 psc_conclude(state);
886 }
887
888 /* psc_cache_validator - validate one cache entry */
889
psc_cache_validator(const char * client_addr,const char * stamp_str,void * unused_context)890 static int psc_cache_validator(const char *client_addr,
891 const char *stamp_str,
892 void *unused_context)
893 {
894 PSC_STATE dummy_state;
895 PSC_CLIENT_INFO dummy_client_info;
896
897 /*
898 * This function is called by the cache cleanup pseudo thread.
899 *
900 * When an entry is removed from the cache, the client will be reported as
901 * "NEW" in the next session where it passes all tests again. To avoid
902 * silly logging we remove the cache entry only after all tests have
903 * expired longer ago than the cache retention time.
904 */
905 dummy_state.client_info = &dummy_client_info;
906 psc_parse_tests(&dummy_state, stamp_str, event_time() - var_psc_cache_ret);
907 return ((dummy_state.flags & PSC_STATE_MASK_ANY_TODO) == 0);
908 }
909
910 /* pre_jail_init - pre-jail initialization */
911
pre_jail_init(char * unused_name,char ** unused_argv)912 static void pre_jail_init(char *unused_name, char **unused_argv)
913 {
914 VSTRING *redirect;
915
916 /*
917 * Open read-only maps before dropping privilege, for consistency with
918 * other Postfix daemons.
919 */
920 psc_acl_pre_jail_init(var_mynetworks, VAR_PSC_ACL);
921 if (*var_psc_acl)
922 psc_acl = psc_acl_parse(var_psc_acl, VAR_PSC_ACL);
923 /* Ignore smtpd_forbid_cmds lookup errors. Non-critical feature. */
924 if (*var_psc_forbid_cmds)
925 psc_forbid_cmds = string_list_init(VAR_PSC_FORBID_CMDS,
926 MATCH_FLAG_RETURN,
927 var_psc_forbid_cmds);
928 if (*var_psc_dnsbl_reply)
929 psc_dnsbl_reply = dict_open(var_psc_dnsbl_reply, O_RDONLY,
930 DICT_FLAG_DUP_WARN);
931
932 /*
933 * Never, ever, get killed by a master signal, as that would corrupt the
934 * database when we're in the middle of an update.
935 */
936 if (setsid() < 0)
937 msg_warn("setsid: %m");
938
939 /*
940 * Security: don't create root-owned files that contain untrusted data.
941 * And don't create Postfix-owned files in root-owned directories,
942 * either. We want a correct relationship between (file or directory)
943 * ownership and (file or directory) content. To open files before going
944 * to jail, temporarily drop root privileges.
945 */
946 SAVE_AND_SET_EUGID(var_owner_uid, var_owner_gid);
947 redirect = vstring_alloc(100);
948
949 /*
950 * Keep state in persistent external map. As a safety measure we sync the
951 * database on each update. This hurts on LINUX file systems that sync
952 * all dirty disk blocks whenever any application invokes fsync().
953 *
954 * Start the cache maintenance pseudo thread after dropping privileges.
955 */
956 #define PSC_DICT_OPEN_FLAGS (DICT_FLAG_DUP_REPLACE | DICT_FLAG_SYNC_UPDATE | \
957 DICT_FLAG_OPEN_LOCK)
958
959 if (*var_psc_cache_map)
960 psc_cache_map =
961 dict_cache_open(data_redirect_map(redirect, var_psc_cache_map),
962 O_CREAT | O_RDWR, PSC_DICT_OPEN_FLAGS);
963
964 /*
965 * Clean up and restore privilege.
966 */
967 vstring_free(redirect);
968 RESTORE_SAVED_EUGID();
969
970 /*
971 * Initialize the dummy SMTP engine.
972 */
973 psc_smtpd_pre_jail_init();
974 }
975
976 /* pre_accept - see if tables have changed */
977
pre_accept(char * unused_name,char ** unused_argv)978 static void pre_accept(char *unused_name, char **unused_argv)
979 {
980 static time_t last_event_time;
981 time_t new_event_time;
982 const char *name;
983
984 /*
985 * If some table has changed then stop accepting new connections. Don't
986 * check the tables more than once a second.
987 */
988 new_event_time = event_time();
989 if (new_event_time >= last_event_time + 1
990 && (name = dict_changed_name()) != 0) {
991 msg_info("table %s has changed - finishing in the background", name);
992 event_server_drain();
993 } else {
994 last_event_time = new_event_time;
995 }
996 }
997
998 /* post_jail_init - post-jail initialization */
999
post_jail_init(char * unused_name,char ** unused_argv)1000 static void post_jail_init(char *unused_name, char **unused_argv)
1001 {
1002 const NAME_CODE actions[] = {
1003 PSC_NAME_ACT_DROP, PSC_ACT_DROP,
1004 PSC_NAME_ACT_ENFORCE, PSC_ACT_ENFORCE,
1005 PSC_NAME_ACT_IGNORE, PSC_ACT_IGNORE,
1006 PSC_NAME_ACT_CONT, PSC_ACT_IGNORE, /* compatibility */
1007 0, -1,
1008 };
1009 int cache_flags;
1010 const char *tmp;
1011
1012 /*
1013 * This routine runs after the skeleton code has entered the chroot jail.
1014 * Prevent automatic process suicide after a limited number of client
1015 * requests. It is OK to terminate after a limited amount of idle time.
1016 */
1017 var_use_limit = 0;
1018
1019 /*
1020 * Workaround for parameters whose values may contain "$", and that have
1021 * a default of "$parametername". Not sure if it would be a good idea to
1022 * always to this in the mail_conf_raw(3) module.
1023 */
1024 if (*var_psc_rej_footer == '$'
1025 && mail_conf_lookup(var_psc_rej_footer + 1)) {
1026 tmp = mail_conf_eval_once(var_psc_rej_footer);
1027 myfree(var_psc_rej_footer);
1028 var_psc_rej_footer = mystrdup(tmp);
1029 }
1030 if (*var_psc_exp_filter == '$'
1031 && mail_conf_lookup(var_psc_exp_filter + 1)) {
1032 tmp = mail_conf_eval_once(var_psc_exp_filter);
1033 myfree(var_psc_exp_filter);
1034 var_psc_exp_filter = mystrdup(tmp);
1035 }
1036
1037 /*
1038 * Other one-time initialization.
1039 */
1040 psc_temp = vstring_alloc(10);
1041 vstring_sprintf(psc_temp, "%s/%s", MAIL_CLASS_PRIVATE, var_smtpd_service);
1042 psc_smtpd_service_name = mystrdup(STR(psc_temp));
1043 psc_dnsbl_init();
1044 psc_early_init();
1045 psc_smtpd_init();
1046
1047 if ((psc_dnlist_action = name_code(actions, NAME_CODE_FLAG_NONE,
1048 var_psc_dnlist_action)) < 0)
1049 msg_fatal("bad %s value: %s", VAR_PSC_DNLIST_ACTION,
1050 var_psc_dnlist_action);
1051 if ((psc_dnsbl_action = name_code(actions, NAME_CODE_FLAG_NONE,
1052 var_psc_dnsbl_action)) < 0)
1053 msg_fatal("bad %s value: %s", VAR_PSC_DNSBL_ACTION,
1054 var_psc_dnsbl_action);
1055 if ((psc_pregr_action = name_code(actions, NAME_CODE_FLAG_NONE,
1056 var_psc_pregr_action)) < 0)
1057 msg_fatal("bad %s value: %s", VAR_PSC_PREGR_ACTION,
1058 var_psc_pregr_action);
1059 if ((psc_pipel_action = name_code(actions, NAME_CODE_FLAG_NONE,
1060 var_psc_pipel_action)) < 0)
1061 msg_fatal("bad %s value: %s", VAR_PSC_PIPEL_ACTION,
1062 var_psc_pipel_action);
1063 if ((psc_nsmtp_action = name_code(actions, NAME_CODE_FLAG_NONE,
1064 var_psc_nsmtp_action)) < 0)
1065 msg_fatal("bad %s value: %s", VAR_PSC_NSMTP_ACTION,
1066 var_psc_nsmtp_action);
1067 if ((psc_barlf_action = name_code(actions, NAME_CODE_FLAG_NONE,
1068 var_psc_barlf_action)) < 0)
1069 msg_fatal("bad %s value: %s", VAR_PSC_BARLF_ACTION,
1070 var_psc_barlf_action);
1071 /* Fail "closed" on error. */
1072 psc_allist_if = addr_match_list_init(VAR_PSC_ALLIST_IF, MATCH_FLAG_RETURN,
1073 var_psc_allist_if);
1074
1075 /*
1076 * Start the cache maintenance pseudo thread last. Early cleanup makes
1077 * verbose logging more informative (we get positive confirmation that
1078 * the cleanup thread runs).
1079 */
1080 cache_flags = DICT_CACHE_FLAG_STATISTICS;
1081 if (msg_verbose > 1)
1082 cache_flags |= DICT_CACHE_FLAG_VERBOSE;
1083 if (psc_cache_map != 0 && var_psc_cache_scan > 0)
1084 dict_cache_control(psc_cache_map,
1085 CA_DICT_CACHE_CTL_FLAGS(cache_flags),
1086 CA_DICT_CACHE_CTL_INTERVAL(var_psc_cache_scan),
1087 CA_DICT_CACHE_CTL_VALIDATOR(psc_cache_validator),
1088 CA_DICT_CACHE_CTL_CONTEXT((void *) 0),
1089 CA_DICT_CACHE_CTL_END);
1090
1091 /*
1092 * Pre-compute the minimal and maximal TTL.
1093 */
1094 psc_min_ttl =
1095 PSC_MIN(PSC_MIN(var_psc_pregr_ttl, var_psc_dnsbl_min_ttl),
1096 PSC_MIN(PSC_MIN(var_psc_pipel_ttl, var_psc_nsmtp_ttl),
1097 var_psc_barlf_ttl));
1098
1099 /*
1100 * Pre-compute the stress and normal command time limits.
1101 */
1102 mail_conf_update(VAR_STRESS, "yes");
1103 psc_stress_cmd_time_limit =
1104 get_mail_conf_time(VAR_PSC_CMD_TIME, DEF_PSC_CMD_TIME, 1, 0);
1105 psc_stress_greet_wait =
1106 get_mail_conf_time(VAR_PSC_GREET_WAIT, DEF_PSC_GREET_WAIT, 1, 0);
1107
1108 mail_conf_update(VAR_STRESS, "");
1109 psc_normal_cmd_time_limit =
1110 get_mail_conf_time(VAR_PSC_CMD_TIME, DEF_PSC_CMD_TIME, 1, 0);
1111 psc_normal_greet_wait =
1112 get_mail_conf_time(VAR_PSC_GREET_WAIT, DEF_PSC_GREET_WAIT, 1, 0);
1113
1114 psc_lowat_check_queue_length = .7 * var_psc_pre_queue_limit;
1115 psc_hiwat_check_queue_length = .9 * var_psc_pre_queue_limit;
1116 if (msg_verbose)
1117 msg_info(VAR_PSC_CMD_TIME ": stress=%d normal=%d lowat=%d hiwat=%d",
1118 psc_stress_cmd_time_limit, psc_normal_cmd_time_limit,
1119 psc_lowat_check_queue_length, psc_hiwat_check_queue_length);
1120
1121 if (psc_lowat_check_queue_length == 0)
1122 msg_panic("compiler error: 0.7 * %d = %d", var_psc_pre_queue_limit,
1123 psc_lowat_check_queue_length);
1124 if (psc_hiwat_check_queue_length == 0)
1125 msg_panic("compiler error: 0.9 * %d = %d", var_psc_pre_queue_limit,
1126 psc_hiwat_check_queue_length);
1127
1128 /*
1129 * Per-client concurrency.
1130 */
1131 psc_client_concurrency = htable_create(var_psc_pre_queue_limit);
1132 }
1133
1134 MAIL_VERSION_STAMP_DECLARE;
1135
1136 /* main - pass control to the multi-threaded skeleton */
1137
main(int argc,char ** argv)1138 int main(int argc, char **argv)
1139 {
1140
1141 /*
1142 * List smtpd(8) parameters before any postscreen(8) parameters that have
1143 * defaults dependencies on them.
1144 */
1145 static const CONFIG_STR_TABLE str_table[] = {
1146 VAR_SMTPD_SERVICE, DEF_SMTPD_SERVICE, &var_smtpd_service, 1, 0,
1147 VAR_SMTPD_BANNER, DEF_SMTPD_BANNER, &var_smtpd_banner, 1, 0,
1148 VAR_SMTPD_FORBID_CMDS, DEF_SMTPD_FORBID_CMDS, &var_smtpd_forbid_cmds, 0, 0,
1149 VAR_SMTPD_EHLO_DIS_WORDS, DEF_SMTPD_EHLO_DIS_WORDS, &var_smtpd_ehlo_dis_words, 0, 0,
1150 VAR_SMTPD_EHLO_DIS_MAPS, DEF_SMTPD_EHLO_DIS_MAPS, &var_smtpd_ehlo_dis_maps, 0, 0,
1151 VAR_SMTPD_TLS_LEVEL, DEF_SMTPD_TLS_LEVEL, &var_smtpd_tls_level, 0, 0,
1152 VAR_SMTPD_CMD_FILTER, DEF_SMTPD_CMD_FILTER, &var_smtpd_cmd_filter, 0, 0,
1153 VAR_PSC_CACHE_MAP, DEF_PSC_CACHE_MAP, &var_psc_cache_map, 0, 0,
1154 VAR_PSC_PREGR_BANNER, DEF_PSC_PREGR_BANNER, &var_psc_pregr_banner, 0, 0,
1155 VAR_PSC_PREGR_ACTION, DEF_PSC_PREGR_ACTION, &var_psc_pregr_action, 1, 0,
1156 VAR_PSC_DNSBL_SITES, DEF_PSC_DNSBL_SITES, &var_psc_dnsbl_sites, 0, 0,
1157 VAR_PSC_DNSBL_ACTION, DEF_PSC_DNSBL_ACTION, &var_psc_dnsbl_action, 1, 0,
1158 VAR_PSC_PIPEL_ACTION, DEF_PSC_PIPEL_ACTION, &var_psc_pipel_action, 1, 0,
1159 VAR_PSC_NSMTP_ACTION, DEF_PSC_NSMTP_ACTION, &var_psc_nsmtp_action, 1, 0,
1160 VAR_PSC_BARLF_ACTION, DEF_PSC_BARLF_ACTION, &var_psc_barlf_action, 1, 0,
1161 VAR_PSC_ACL, DEF_PSC_ACL, &var_psc_acl, 0, 0,
1162 VAR_PSC_DNLIST_ACTION, DEF_PSC_DNLIST_ACTION, &var_psc_dnlist_action, 1, 0,
1163 VAR_PSC_FORBID_CMDS, DEF_PSC_FORBID_CMDS, &var_psc_forbid_cmds, 0, 0,
1164 VAR_PSC_EHLO_DIS_WORDS, DEF_PSC_EHLO_DIS_WORDS, &var_psc_ehlo_dis_words, 0, 0,
1165 VAR_PSC_EHLO_DIS_MAPS, DEF_PSC_EHLO_DIS_MAPS, &var_psc_ehlo_dis_maps, 0, 0,
1166 VAR_PSC_DNSBL_REPLY, DEF_PSC_DNSBL_REPLY, &var_psc_dnsbl_reply, 0, 0,
1167 VAR_PSC_TLS_LEVEL, DEF_PSC_TLS_LEVEL, &var_psc_tls_level, 0, 0,
1168 VAR_PSC_CMD_FILTER, DEF_PSC_CMD_FILTER, &var_psc_cmd_filter, 0, 0,
1169 VAR_DNSBLOG_SERVICE, DEF_DNSBLOG_SERVICE, &var_dnsblog_service, 1, 0,
1170 VAR_TLSPROXY_SERVICE, DEF_TLSPROXY_SERVICE, &var_tlsproxy_service, 1, 0,
1171 VAR_PSC_ALLIST_IF, DEF_PSC_ALLIST_IF, &var_psc_allist_if, 0, 0,
1172 VAR_PSC_UPROXY_PROTO, DEF_PSC_UPROXY_PROTO, &var_psc_uproxy_proto, 0, 0,
1173 VAR_PSC_REJ_FTR_MAPS, DEF_PSC_REJ_FTR_MAPS, &var_psc_rej_ftr_maps, 0, 0,
1174 0,
1175 };
1176 static const CONFIG_INT_TABLE int_table[] = {
1177 VAR_PSC_DNSBL_THRESH, DEF_PSC_DNSBL_THRESH, &var_psc_dnsbl_thresh, 0, 0,
1178 VAR_PSC_CMD_COUNT, DEF_PSC_CMD_COUNT, &var_psc_cmd_count, 1, 0,
1179 VAR_SMTPD_CCONN_LIMIT, DEF_SMTPD_CCONN_LIMIT, &var_smtpd_cconn_limit, 0, 0,
1180 0,
1181 };
1182 static const CONFIG_NINT_TABLE nint_table[] = {
1183 VAR_PSC_POST_QLIMIT, DEF_PSC_POST_QLIMIT, &var_psc_post_queue_limit, 5, 0,
1184 VAR_PSC_PRE_QLIMIT, DEF_PSC_PRE_QLIMIT, &var_psc_pre_queue_limit, 10, 0,
1185 VAR_PSC_CCONN_LIMIT, DEF_PSC_CCONN_LIMIT, &var_psc_cconn_limit, 0, 0,
1186 VAR_PSC_DNSBL_ALTHRESH, DEF_PSC_DNSBL_ALTHRESH, &var_psc_dnsbl_althresh, 0, 0,
1187 0,
1188 };
1189 static const CONFIG_TIME_TABLE time_table[] = {
1190 VAR_PSC_CMD_TIME, DEF_PSC_CMD_TIME, &var_psc_cmd_time, 1, 0,
1191 VAR_PSC_GREET_WAIT, DEF_PSC_GREET_WAIT, &var_psc_greet_wait, 1, 0,
1192 VAR_PSC_PREGR_TTL, DEF_PSC_PREGR_TTL, &var_psc_pregr_ttl, 1, 0,
1193 VAR_PSC_DNSBL_MIN_TTL, DEF_PSC_DNSBL_MIN_TTL, &var_psc_dnsbl_min_ttl, 1, 0,
1194 VAR_PSC_DNSBL_MAX_TTL, DEF_PSC_DNSBL_MAX_TTL, &var_psc_dnsbl_max_ttl, 1, 0,
1195 VAR_PSC_PIPEL_TTL, DEF_PSC_PIPEL_TTL, &var_psc_pipel_ttl, 1, 0,
1196 VAR_PSC_NSMTP_TTL, DEF_PSC_NSMTP_TTL, &var_psc_nsmtp_ttl, 1, 0,
1197 VAR_PSC_BARLF_TTL, DEF_PSC_BARLF_TTL, &var_psc_barlf_ttl, 1, 0,
1198 VAR_PSC_CACHE_RET, DEF_PSC_CACHE_RET, &var_psc_cache_ret, 1, 0,
1199 VAR_PSC_CACHE_SCAN, DEF_PSC_CACHE_SCAN, &var_psc_cache_scan, 0, 0,
1200 VAR_PSC_WATCHDOG, DEF_PSC_WATCHDOG, &var_psc_watchdog, 10, 0,
1201 VAR_PSC_UPROXY_TMOUT, DEF_PSC_UPROXY_TMOUT, &var_psc_uproxy_tmout, 1, 0,
1202 VAR_PSC_DNSBL_TMOUT, DEF_PSC_DNSBL_TMOUT, &var_psc_dnsbl_tmout, 1, 0,
1203
1204 0,
1205 };
1206 static const CONFIG_BOOL_TABLE bool_table[] = {
1207 VAR_HELO_REQUIRED, DEF_HELO_REQUIRED, &var_helo_required,
1208 VAR_DISABLE_VRFY_CMD, DEF_DISABLE_VRFY_CMD, &var_disable_vrfy_cmd,
1209 VAR_SMTPD_USE_TLS, DEF_SMTPD_USE_TLS, &var_smtpd_use_tls,
1210 VAR_SMTPD_ENFORCE_TLS, DEF_SMTPD_ENFORCE_TLS, &var_smtpd_enforce_tls,
1211 VAR_PSC_PIPEL_ENABLE, DEF_PSC_PIPEL_ENABLE, &var_psc_pipel_enable,
1212 VAR_PSC_NSMTP_ENABLE, DEF_PSC_NSMTP_ENABLE, &var_psc_nsmtp_enable,
1213 VAR_PSC_BARLF_ENABLE, DEF_PSC_BARLF_ENABLE, &var_psc_barlf_enable,
1214 0,
1215 };
1216 static const CONFIG_RAW_TABLE raw_table[] = {
1217 VAR_SMTPD_REJ_FOOTER, DEF_SMTPD_REJ_FOOTER, &var_smtpd_rej_footer, 0, 0,
1218 VAR_PSC_REJ_FOOTER, DEF_PSC_REJ_FOOTER, &var_psc_rej_footer, 0, 0,
1219 VAR_SMTPD_EXP_FILTER, DEF_SMTPD_EXP_FILTER, &var_smtpd_exp_filter, 1, 0,
1220 VAR_PSC_EXP_FILTER, DEF_PSC_EXP_FILTER, &var_psc_exp_filter, 1, 0,
1221 0,
1222 };
1223 static const CONFIG_NBOOL_TABLE nbool_table[] = {
1224 VAR_PSC_HELO_REQUIRED, DEF_PSC_HELO_REQUIRED, &var_psc_helo_required,
1225 VAR_PSC_DISABLE_VRFY, DEF_PSC_DISABLE_VRFY, &var_psc_disable_vrfy,
1226 VAR_PSC_USE_TLS, DEF_PSC_USE_TLS, &var_psc_use_tls,
1227 VAR_PSC_ENFORCE_TLS, DEF_PSC_ENFORCE_TLS, &var_psc_enforce_tls,
1228 0,
1229 };
1230
1231 /*
1232 * Fingerprint executables and core dumps.
1233 */
1234 MAIL_VERSION_STAMP_ALLOCATE;
1235
1236 event_server_main(argc, argv, psc_service,
1237 CA_MAIL_SERVER_STR_TABLE(str_table),
1238 CA_MAIL_SERVER_INT_TABLE(int_table),
1239 CA_MAIL_SERVER_NINT_TABLE(nint_table),
1240 CA_MAIL_SERVER_TIME_TABLE(time_table),
1241 CA_MAIL_SERVER_BOOL_TABLE(bool_table),
1242 CA_MAIL_SERVER_RAW_TABLE(raw_table),
1243 CA_MAIL_SERVER_NBOOL_TABLE(nbool_table),
1244 CA_MAIL_SERVER_PRE_INIT(pre_jail_init),
1245 CA_MAIL_SERVER_POST_INIT(post_jail_init),
1246 CA_MAIL_SERVER_PRE_ACCEPT(pre_accept),
1247 CA_MAIL_SERVER_SOLITARY,
1248 CA_MAIL_SERVER_SLOW_EXIT(psc_drain),
1249 CA_MAIL_SERVER_EXIT(psc_dump),
1250 CA_MAIL_SERVER_WATCHDOG(&var_psc_watchdog),
1251 0);
1252 }
1253