1 /* $NetBSD: postscreen.c,v 1.2 2017/02/14 01:16:47 christos Exp $ */ 2 3 /*++ 4 /* NAME 5 /* postscreen 8 6 /* SUMMARY 7 /* Postfix zombie blocker 8 /* SYNOPSIS 9 /* \fBpostscreen\fR [generic Postfix daemon options] 10 /* DESCRIPTION 11 /* The Postfix \fBpostscreen\fR(8) server provides additional 12 /* protection against mail server overload. One \fBpostscreen\fR(8) 13 /* process handles multiple inbound SMTP connections, and decides 14 /* which clients may talk to a Postfix SMTP server process. 15 /* By keeping spambots away, \fBpostscreen\fR(8) leaves more 16 /* SMTP server processes available for legitimate clients, and 17 /* delays the onset of server overload conditions. 18 /* 19 /* This program should not be used on SMTP ports that receive 20 /* mail from end-user clients (MUAs). In a typical deployment, 21 /* \fBpostscreen\fR(8) handles the MX service on TCP port 25, 22 /* while MUA clients submit mail via the \fBsubmission\fR 23 /* service on TCP port 587 which requires client authentication. 24 /* Alternatively, a site could set up a dedicated, non-postscreen, 25 /* "port 25" server that provides \fBsubmission\fR service and 26 /* client authentication, but no MX service. 27 /* 28 /* \fBpostscreen\fR(8) maintains a temporary whitelist for 29 /* clients that have passed a number of tests. When an SMTP 30 /* client IP address is whitelisted, \fBpostscreen\fR(8) hands 31 /* off the connection immediately to a Postfix SMTP server 32 /* process. This minimizes the overhead for legitimate mail. 33 /* 34 /* By default, \fBpostscreen\fR(8) logs statistics and hands 35 /* off each connection to a Postfix SMTP server process, while 36 /* excluding clients in mynetworks from all tests (primarily, 37 /* to avoid problems with non-standard SMTP implementations 38 /* in network appliances). This default mode blocks no clients, 39 /* and is useful for non-destructive testing. 40 /* 41 /* In a typical production setting, \fBpostscreen\fR(8) is 42 /* configured to reject mail from clients that fail one or 43 /* more tests. \fBpostscreen\fR(8) logs rejected mail with the 44 /* client address, helo, sender and recipient information. 45 /* 46 /* \fBpostscreen\fR(8) is not an SMTP proxy; this is intentional. 47 /* The purpose is to keep spambots away from Postfix SMTP 48 /* server processes, while minimizing overhead for legitimate 49 /* traffic. 50 /* SECURITY 51 /* .ad 52 /* .fi 53 /* The \fBpostscreen\fR(8) server is moderately security-sensitive. 54 /* It talks to untrusted clients on the network. The process 55 /* can be run chrooted at fixed low privilege. 56 /* STANDARDS 57 /* RFC 821 (SMTP protocol) 58 /* RFC 1123 (Host requirements) 59 /* RFC 1652 (8bit-MIME transport) 60 /* RFC 1869 (SMTP service extensions) 61 /* RFC 1870 (Message Size Declaration) 62 /* RFC 1985 (ETRN command) 63 /* RFC 2034 (SMTP Enhanced Status Codes) 64 /* RFC 2821 (SMTP protocol) 65 /* Not: RFC 2920 (SMTP Pipelining) 66 /* RFC 3207 (STARTTLS command) 67 /* RFC 3461 (SMTP DSN Extension) 68 /* RFC 3463 (Enhanced Status Codes) 69 /* RFC 5321 (SMTP protocol, including multi-line 220 banners) 70 /* DIAGNOSTICS 71 /* Problems and transactions are logged to \fBsyslogd\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, and do not use DNSBLs that reject 79 /* traffic from dial-up and residential networks. 80 /* 81 /* The optional "after 220 server greeting" tests involve 82 /* \fBpostscreen\fR(8)'s built-in SMTP protocol engine. When 83 /* these tests succeed, \fBpostscreen\fR(8) adds the client 84 /* to the temporary whitelist, but it cannot hand off the 85 /* "live" connection to a Postfix SMTP server process in the 86 /* middle of a session. Instead, \fBpostscreen\fR(8) defers 87 /* attempts to deliver mail with a 4XX status, and waits for 88 /* the client to disconnect. When the client connects again, 89 /* \fBpostscreen\fR(8) will allow the client to talk to a 90 /* Postfix SMTP server process (provided that the whitelist 91 /* status has not expired). \fBpostscreen\fR(8) mitigates 92 /* the impact of this limitation by giving the "after 220 93 /* server greeting" tests a long expiration time. 94 /* CONFIGURATION PARAMETERS 95 /* .ad 96 /* .fi 97 /* Changes to main.cf are not picked up automatically, as 98 /* \fBpostscreen\fR(8) processes may run for several hours. 99 /* Use the command "postfix reload" after a configuration 100 /* change. 101 /* 102 /* The text below provides only a parameter summary. See 103 /* \fBpostconf\fR(5) for more details including examples. 104 /* 105 /* NOTE: Some \fBpostscreen\fR(8) parameters implement 106 /* stress-dependent behavior. This is supported only when the 107 /* default parameter value is stress-dependent (that is, it 108 /* looks like ${stress?{X}:{Y}}, or it is the $\fIname\fR 109 /* of an smtpd parameter with a stress-dependent default). 110 /* Other parameters always evaluate as if the \fBstress\fR 111 /* parameter value is the empty string. 112 /* COMPATIBILITY CONTROLS 113 /* .ad 114 /* .fi 115 /* .IP "\fBpostscreen_command_filter ($smtpd_command_filter)\fR" 116 /* A mechanism to transform commands from remote SMTP clients. 117 /* .IP "\fBpostscreen_discard_ehlo_keyword_address_maps ($smtpd_discard_ehlo_keyword_address_maps)\fR" 118 /* Lookup tables, indexed by the remote SMTP client address, with 119 /* case insensitive lists of EHLO keywords (pipelining, starttls, auth, 120 /* etc.) that the \fBpostscreen\fR(8) server will not send in the EHLO response 121 /* to a remote SMTP client. 122 /* .IP "\fBpostscreen_discard_ehlo_keywords ($smtpd_discard_ehlo_keywords)\fR" 123 /* A case insensitive list of EHLO keywords (pipelining, starttls, 124 /* auth, etc.) that the \fBpostscreen\fR(8) server will not send in the EHLO 125 /* response to a remote SMTP client. 126 /* .PP 127 /* Available in Postfix version 3.1 and later: 128 /* .IP "\fBdns_ncache_ttl_fix_enable (no)\fR" 129 /* Enable a workaround for future libc incompatibility. 130 /* TROUBLE SHOOTING CONTROLS 131 /* .ad 132 /* .fi 133 /* .IP "\fBpostscreen_expansion_filter (see 'postconf -d' output)\fR" 134 /* List of characters that are permitted in postscreen_reject_footer 135 /* attribute expansions. 136 /* .IP "\fBpostscreen_reject_footer ($smtpd_reject_footer)\fR" 137 /* Optional information that is appended after a 4XX or 5XX 138 /* \fBpostscreen\fR(8) server 139 /* response. 140 /* .IP "\fBsoft_bounce (no)\fR" 141 /* Safety net to keep mail queued that would otherwise be returned to 142 /* the sender. 143 /* BEFORE-POSTSCREEN PROXY AGENT 144 /* .ad 145 /* .fi 146 /* Available in Postfix version 2.10 and later: 147 /* .IP "\fBpostscreen_upstream_proxy_protocol (empty)\fR" 148 /* The name of the proxy protocol used by an optional before-postscreen 149 /* proxy agent. 150 /* .IP "\fBpostscreen_upstream_proxy_timeout (5s)\fR" 151 /* The time limit for the proxy protocol specified with the 152 /* postscreen_upstream_proxy_protocol parameter. 153 /* PERMANENT WHITE/BLACKLIST TEST 154 /* .ad 155 /* .fi 156 /* This test is executed immediately after a remote SMTP client 157 /* connects. If a client is permanently whitelisted, the client 158 /* will be handed off immediately to a Postfix SMTP server 159 /* process. 160 /* .IP "\fBpostscreen_access_list (permit_mynetworks)\fR" 161 /* Permanent white/blacklist for remote SMTP client IP addresses. 162 /* .IP "\fBpostscreen_blacklist_action (ignore)\fR" 163 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client is 164 /* permanently blacklisted with the postscreen_access_list parameter. 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 whitelist 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 /* A list of local \fBpostscreen\fR(8) server IP addresses where a 177 /* non-whitelisted remote SMTP client can obtain \fBpostscreen\fR(8)'s temporary 178 /* whitelist status. 179 /* BEFORE 220 GREETING TESTS 180 /* .ad 181 /* .fi 182 /* These tests are executed before the remote SMTP client 183 /* receives the "220 servername" greeting. If no tests remain 184 /* after the successful completion of this phase, the client 185 /* will be handed off immediately to a Postfix SMTP server 186 /* process. 187 /* .IP "\fBdnsblog_service_name (dnsblog)\fR" 188 /* The name of the \fBdnsblog\fR(8) service entry in master.cf. 189 /* .IP "\fBpostscreen_dnsbl_action (ignore)\fR" 190 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client's combined 191 /* DNSBL score is equal to or greater than a threshold (as defined 192 /* with the postscreen_dnsbl_sites and postscreen_dnsbl_threshold 193 /* parameters). 194 /* .IP "\fBpostscreen_dnsbl_reply_map (empty)\fR" 195 /* A mapping from actual DNSBL domain name which includes a secret 196 /* password, to the DNSBL domain name that postscreen will reply with 197 /* when it rejects mail. 198 /* .IP "\fBpostscreen_dnsbl_sites (empty)\fR" 199 /* Optional list of DNS white/blacklist domains, filters and weight 200 /* factors. 201 /* .IP "\fBpostscreen_dnsbl_threshold (1)\fR" 202 /* The inclusive lower bound for blocking a remote SMTP client, based on 203 /* its combined DNSBL score as defined with the postscreen_dnsbl_sites 204 /* parameter. 205 /* .IP "\fBpostscreen_greet_action (ignore)\fR" 206 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client speaks 207 /* before its turn within the time specified with the postscreen_greet_wait 208 /* parameter. 209 /* .IP "\fBpostscreen_greet_banner ($smtpd_banner)\fR" 210 /* The \fItext\fR in the optional "220-\fItext\fR..." server 211 /* response that 212 /* \fBpostscreen\fR(8) sends ahead of the real Postfix SMTP server's "220 213 /* text..." response, in an attempt to confuse bad SMTP clients so 214 /* that they speak before their turn (pre-greet). 215 /* .IP "\fBpostscreen_greet_wait (normal: 6s, overload: 2s)\fR" 216 /* The amount of time that \fBpostscreen\fR(8) will wait for an SMTP 217 /* client to send a command before its turn, and for DNS blocklist 218 /* lookup results to arrive (default: up to 2 seconds under stress, 219 /* up to 6 seconds otherwise). 220 /* .IP "\fBsmtpd_service_name (smtpd)\fR" 221 /* The internal service that \fBpostscreen\fR(8) hands off allowed 222 /* connections to. 223 /* .PP 224 /* Available in Postfix version 2.11 and later: 225 /* .IP "\fBpostscreen_dnsbl_whitelist_threshold (0)\fR" 226 /* Allow a remote SMTP client to skip "before" and "after 220 227 /* greeting" protocol tests, based on its combined DNSBL score as 228 /* defined with the postscreen_dnsbl_sites parameter. 229 /* .PP 230 /* Available in Postfix version 3.0 and later: 231 /* .IP "\fBpostscreen_dnsbl_timeout (10s)\fR" 232 /* The time limit for DNSBL or DNSWL lookups. 233 /* AFTER 220 GREETING TESTS 234 /* .ad 235 /* .fi 236 /* These tests are executed after the remote SMTP client 237 /* receives the "220 servername" greeting. If a client passes 238 /* all tests during this phase, it will receive a 4XX response 239 /* to all RCPT TO commands. After the client reconnects, it 240 /* will be allowed to talk directly to a Postfix SMTP server 241 /* process. 242 /* .IP "\fBpostscreen_bare_newline_action (ignore)\fR" 243 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client sends 244 /* a bare newline character, that is, a newline not preceded by carriage 245 /* return. 246 /* .IP "\fBpostscreen_bare_newline_enable (no)\fR" 247 /* Enable "bare newline" SMTP protocol tests in the \fBpostscreen\fR(8) 248 /* server. 249 /* .IP "\fBpostscreen_disable_vrfy_command ($disable_vrfy_command)\fR" 250 /* Disable the SMTP VRFY command in the \fBpostscreen\fR(8) daemon. 251 /* .IP "\fBpostscreen_forbidden_commands ($smtpd_forbidden_commands)\fR" 252 /* List of commands that the \fBpostscreen\fR(8) server considers in 253 /* violation of the SMTP protocol. 254 /* .IP "\fBpostscreen_helo_required ($smtpd_helo_required)\fR" 255 /* Require that a remote SMTP client sends HELO or EHLO before 256 /* commencing a MAIL transaction. 257 /* .IP "\fBpostscreen_non_smtp_command_action (drop)\fR" 258 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client sends 259 /* non-SMTP commands as specified with the postscreen_forbidden_commands 260 /* parameter. 261 /* .IP "\fBpostscreen_non_smtp_command_enable (no)\fR" 262 /* Enable "non-SMTP command" tests in the \fBpostscreen\fR(8) server. 263 /* .IP "\fBpostscreen_pipelining_action (enforce)\fR" 264 /* The action that \fBpostscreen\fR(8) takes when a remote SMTP client 265 /* sends 266 /* multiple commands instead of sending one command and waiting for 267 /* the server to respond. 268 /* .IP "\fBpostscreen_pipelining_enable (no)\fR" 269 /* Enable "pipelining" SMTP protocol tests in the \fBpostscreen\fR(8) 270 /* server. 271 /* CACHE CONTROLS 272 /* .ad 273 /* .fi 274 /* .IP "\fBpostscreen_cache_cleanup_interval (12h)\fR" 275 /* The amount of time between \fBpostscreen\fR(8) cache cleanup runs. 276 /* .IP "\fBpostscreen_cache_map (btree:$data_directory/postscreen_cache)\fR" 277 /* Persistent storage for the \fBpostscreen\fR(8) server decisions. 278 /* .IP "\fBpostscreen_cache_retention_time (7d)\fR" 279 /* The amount of time that \fBpostscreen\fR(8) will cache an expired 280 /* temporary whitelist entry before it is removed. 281 /* .IP "\fBpostscreen_bare_newline_ttl (30d)\fR" 282 /* The amount of time that \fBpostscreen\fR(8) will use the result from 283 /* a successful "bare newline" SMTP protocol test. 284 /* .IP "\fBpostscreen_dnsbl_max_ttl (${postscreen_dnsbl_ttl?{$postscreen_dnsbl_ttl}:{1}}h)\fR" 285 /* The maximum amount of time that \fBpostscreen\fR(8) will use the 286 /* result from a successful DNS-based reputation test before a 287 /* client IP address is required to pass that test again. 288 /* .IP "\fBpostscreen_dnsbl_min_ttl (60s)\fR" 289 /* The minimum amount of time that \fBpostscreen\fR(8) will use the 290 /* result from a successful DNS-based reputation test before a 291 /* client IP address is required to pass that test again. 292 /* .IP "\fBpostscreen_greet_ttl (1d)\fR" 293 /* The amount of time that \fBpostscreen\fR(8) will use the result from 294 /* a successful PREGREET test. 295 /* .IP "\fBpostscreen_non_smtp_command_ttl (30d)\fR" 296 /* The amount of time that \fBpostscreen\fR(8) will use the result from 297 /* a successful "non_smtp_command" SMTP protocol test. 298 /* .IP "\fBpostscreen_pipelining_ttl (30d)\fR" 299 /* The amount of time that \fBpostscreen\fR(8) will use the result from 300 /* a successful "pipelining" SMTP protocol test. 301 /* RESOURCE CONTROLS 302 /* .ad 303 /* .fi 304 /* .IP "\fBline_length_limit (2048)\fR" 305 /* Upon input, long lines are chopped up into pieces of at most 306 /* this length; upon delivery, long lines are reconstructed. 307 /* .IP "\fBpostscreen_client_connection_count_limit ($smtpd_client_connection_count_limit)\fR" 308 /* How many simultaneous connections any remote SMTP client is 309 /* allowed to have 310 /* with the \fBpostscreen\fR(8) daemon. 311 /* .IP "\fBpostscreen_command_count_limit (20)\fR" 312 /* The limit on the total number of commands per SMTP session for 313 /* \fBpostscreen\fR(8)'s built-in SMTP protocol engine. 314 /* .IP "\fBpostscreen_command_time_limit (normal: 300s, overload: 10s)\fR" 315 /* The time limit to read an entire command line with \fBpostscreen\fR(8)'s 316 /* built-in SMTP protocol engine. 317 /* .IP "\fBpostscreen_post_queue_limit ($default_process_limit)\fR" 318 /* The number of clients that can be waiting for service from a 319 /* real Postfix SMTP server process. 320 /* .IP "\fBpostscreen_pre_queue_limit ($default_process_limit)\fR" 321 /* The number of non-whitelisted clients that can be waiting for 322 /* a decision whether they will receive service from a real Postfix 323 /* SMTP server 324 /* process. 325 /* .IP "\fBpostscreen_watchdog_timeout (10s)\fR" 326 /* How much time a \fBpostscreen\fR(8) process may take to respond to 327 /* a remote SMTP client command or to perform a cache operation before it 328 /* is terminated by a built-in watchdog timer. 329 /* STARTTLS CONTROLS 330 /* .ad 331 /* .fi 332 /* .IP "\fBpostscreen_tls_security_level ($smtpd_tls_security_level)\fR" 333 /* The SMTP TLS security level for the \fBpostscreen\fR(8) server; when 334 /* a non-empty value is specified, this overrides the obsolete parameters 335 /* postscreen_use_tls and postscreen_enforce_tls. 336 /* .IP "\fBtlsproxy_service_name (tlsproxy)\fR" 337 /* The name of the \fBtlsproxy\fR(8) service entry in master.cf. 338 /* OBSOLETE STARTTLS SUPPORT CONTROLS 339 /* .ad 340 /* .fi 341 /* These parameters are supported for compatibility with 342 /* \fBsmtpd\fR(8) legacy parameters. 343 /* .IP "\fBpostscreen_use_tls ($smtpd_use_tls)\fR" 344 /* Opportunistic TLS: announce STARTTLS support to remote SMTP clients, 345 /* but do not require that clients use TLS encryption. 346 /* .IP "\fBpostscreen_enforce_tls ($smtpd_enforce_tls)\fR" 347 /* Mandatory TLS: announce STARTTLS support to remote SMTP clients, and 348 /* require that clients use TLS encryption. 349 /* MISCELLANEOUS CONTROLS 350 /* .ad 351 /* .fi 352 /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR" 353 /* The default location of the Postfix main.cf and master.cf 354 /* configuration files. 355 /* .IP "\fBdelay_logging_resolution_limit (2)\fR" 356 /* The maximal number of digits after the decimal point when logging 357 /* sub-second delay values. 358 /* .IP "\fBcommand_directory (see 'postconf -d' output)\fR" 359 /* The location of all postfix administrative commands. 360 /* .IP "\fBmax_idle (100s)\fR" 361 /* The maximum amount of time that an idle Postfix daemon process waits 362 /* for an incoming connection before terminating voluntarily. 363 /* .IP "\fBprocess_id (read-only)\fR" 364 /* The process ID of a Postfix command or daemon process. 365 /* .IP "\fBprocess_name (read-only)\fR" 366 /* The process name of a Postfix command or daemon process. 367 /* .IP "\fBsyslog_facility (mail)\fR" 368 /* The syslog facility of Postfix logging. 369 /* .IP "\fBsyslog_name (see 'postconf -d' output)\fR" 370 /* The mail system name that is prepended to the process name in syslog 371 /* records, so that "smtpd" becomes, for example, "postfix/smtpd". 372 /* SEE ALSO 373 /* smtpd(8), Postfix SMTP server 374 /* tlsproxy(8), Postfix TLS proxy server 375 /* dnsblog(8), DNS black/whitelist logger 376 /* syslogd(8), system logging 377 /* README FILES 378 /* .ad 379 /* .fi 380 /* Use "\fBpostconf readme_directory\fR" or "\fBpostconf 381 /* html_directory\fR" to locate this information. 382 /* .nf 383 /* .na 384 /* POSTSCREEN_README, Postfix Postscreen Howto 385 /* LICENSE 386 /* .ad 387 /* .fi 388 /* The Secure Mailer license must be distributed with this software. 389 /* HISTORY 390 /* .ad 391 /* .fi 392 /* This service was introduced with Postfix version 2.8. 393 /* 394 /* Many ideas in \fBpostscreen\fR(8) were explored in earlier 395 /* work by Michael Tokarev, in OpenBSD spamd, and in MailChannels 396 /* Traffic Control. 397 /* AUTHOR(S) 398 /* Wietse Venema 399 /* IBM T.J. Watson Research 400 /* P.O. Box 704 401 /* Yorktown Heights, NY 10598, USA 402 /* 403 /* Wietse Venema 404 /* Google, Inc. 405 /* 111 8th Avenue 406 /* New York, NY 10011, USA 407 /*--*/ 408 409 /* System library. */ 410 411 #include <sys_defs.h> 412 #include <sys/stat.h> 413 #include <stdlib.h> 414 415 /* Utility library. */ 416 417 #include <msg.h> 418 #include <mymalloc.h> 419 #include <events.h> 420 #include <myaddrinfo.h> 421 #include <dict_cache.h> 422 #include <set_eugid.h> 423 #include <vstream.h> 424 #include <name_code.h> 425 #include <inet_proto.h> 426 427 /* Global library. */ 428 429 #include <mail_conf.h> 430 #include <mail_params.h> 431 #include <mail_version.h> 432 #include <mail_proto.h> 433 #include <data_redirect.h> 434 #include <string_list.h> 435 436 /* Master server protocols. */ 437 438 #include <mail_server.h> 439 440 /* Application-specific. */ 441 442 #include <postscreen.h> 443 444 /* 445 * Configuration parameters. 446 */ 447 char *var_smtpd_service; 448 char *var_smtpd_banner; 449 bool var_disable_vrfy_cmd; 450 bool var_helo_required; 451 452 char *var_smtpd_cmd_filter; 453 char *var_psc_cmd_filter; 454 455 char *var_smtpd_forbid_cmds; 456 char *var_psc_forbid_cmds; 457 458 char *var_smtpd_ehlo_dis_words; 459 char *var_smtpd_ehlo_dis_maps; 460 char *var_psc_ehlo_dis_words; 461 char *var_psc_ehlo_dis_maps; 462 463 char *var_smtpd_tls_level; 464 bool var_smtpd_use_tls; 465 bool var_smtpd_enforce_tls; 466 char *var_psc_tls_level; 467 bool var_psc_use_tls; 468 bool var_psc_enforce_tls; 469 470 bool var_psc_disable_vrfy; 471 bool var_psc_helo_required; 472 473 char *var_psc_cache_map; 474 int var_psc_cache_scan; 475 int var_psc_cache_ret; 476 int var_psc_post_queue_limit; 477 int var_psc_pre_queue_limit; 478 int var_psc_watchdog; 479 480 char *var_psc_acl; 481 char *var_psc_blist_action; 482 483 char *var_psc_greet_ttl; 484 int var_psc_greet_wait; 485 486 char *var_psc_pregr_banner; 487 char *var_psc_pregr_action; 488 int var_psc_pregr_ttl; 489 490 char *var_psc_dnsbl_sites; 491 char *var_psc_dnsbl_reply; 492 int var_psc_dnsbl_thresh; 493 int var_psc_dnsbl_wthresh; 494 char *var_psc_dnsbl_action; 495 int var_psc_dnsbl_min_ttl; 496 int var_psc_dnsbl_max_ttl; 497 int var_psc_dnsbl_tmout; 498 499 bool var_psc_pipel_enable; 500 char *var_psc_pipel_action; 501 int var_psc_pipel_ttl; 502 503 bool var_psc_nsmtp_enable; 504 char *var_psc_nsmtp_action; 505 int var_psc_nsmtp_ttl; 506 507 bool var_psc_barlf_enable; 508 char *var_psc_barlf_action; 509 int var_psc_barlf_ttl; 510 511 int var_psc_cmd_count; 512 char *var_psc_cmd_time; 513 514 char *var_dnsblog_service; 515 char *var_tlsproxy_service; 516 517 char *var_smtpd_rej_footer; 518 char *var_psc_rej_footer; 519 520 int var_smtpd_cconn_limit; 521 int var_psc_cconn_limit; 522 523 char *var_smtpd_exp_filter; 524 char *var_psc_exp_filter; 525 526 char *var_psc_wlist_if; 527 char *var_psc_uproxy_proto; 528 int var_psc_uproxy_tmout; 529 530 /* 531 * Global variables. 532 */ 533 int psc_check_queue_length; /* connections being checked */ 534 int psc_post_queue_length; /* being sent to real SMTPD */ 535 DICT_CACHE *psc_cache_map; /* cache table handle */ 536 VSTRING *psc_temp; /* scratchpad */ 537 char *psc_smtpd_service_name; /* path to real SMTPD */ 538 int psc_pregr_action; /* PSC_ACT_DROP/ENFORCE/etc */ 539 int psc_dnsbl_action; /* PSC_ACT_DROP/ENFORCE/etc */ 540 int psc_pipel_action; /* PSC_ACT_DROP/ENFORCE/etc */ 541 int psc_nsmtp_action; /* PSC_ACT_DROP/ENFORCE/etc */ 542 int psc_barlf_action; /* PSC_ACT_DROP/ENFORCE/etc */ 543 int psc_min_ttl; /* Update with new tests! */ 544 STRING_LIST *psc_forbid_cmds; /* CONNECT GET POST */ 545 int psc_stress_greet_wait; /* stressed greet wait */ 546 int psc_normal_greet_wait; /* stressed greet wait */ 547 int psc_stress_cmd_time_limit; /* stressed command limit */ 548 int psc_normal_cmd_time_limit; /* normal command time limit */ 549 int psc_stress; /* stress level */ 550 int psc_lowat_check_queue_length; /* stress low-water mark */ 551 int psc_hiwat_check_queue_length; /* stress high-water mark */ 552 DICT *psc_dnsbl_reply; /* DNSBL name mapper */ 553 HTABLE *psc_client_concurrency; /* per-client concurrency */ 554 555 /* 556 * Local variables and functions. 557 */ 558 static ARGV *psc_acl; /* permanent white/backlist */ 559 static int psc_blist_action; /* PSC_ACT_DROP/ENFORCE/etc */ 560 static ADDR_MATCH_LIST *psc_wlist_if; /* whitelist interfaces */ 561 562 static void psc_endpt_lookup_done(int, VSTREAM *, 563 MAI_HOSTADDR_STR *, MAI_SERVPORT_STR *, 564 MAI_HOSTADDR_STR *, MAI_SERVPORT_STR *); 565 566 /* psc_dump - dump some statistics before exit */ 567 568 static void psc_dump(char *unused_service, char **unused_argv) 569 { 570 571 /* 572 * Dump preliminary cache cleanup statistics when the process commits 573 * suicide while a cache cleanup run is in progress. We can't currently 574 * distinguish between "postfix reload" (we should restart) or "maximal 575 * idle time reached" (we could finish the cache cleanup first). 576 */ 577 if (psc_cache_map) { 578 dict_cache_close(psc_cache_map); 579 psc_cache_map = 0; 580 } 581 } 582 583 /* psc_drain - delayed exit after "postfix reload" */ 584 585 static void psc_drain(char *unused_service, char **unused_argv) 586 { 587 int count; 588 589 /* 590 * After "postfix reload", complete work-in-progress in the background, 591 * instead of dropping already-accepted connections on the floor. 592 * 593 * Unfortunately we must close all writable tables, so we can't store or 594 * look up reputation information. The reason is that we don't have any 595 * multi-writer safety guarantees. We also can't use the single-writer 596 * proxywrite service, because its latency guarantees are too weak. 597 * 598 * All error retry counts shall be limited. Instead of blocking here, we 599 * could retry failed fork() operations in the event call-back routines, 600 * but we don't need perfection. The host system is severely overloaded 601 * and service levels are already way down. 602 * 603 * XXX Some Berkeley DB versions break with close-after-fork. Every new 604 * version is an improvement over its predecessor. 605 */ 606 if (psc_cache_map != 0 /* XXX && psc_cache_map 607 requires locking */ ) { 608 dict_cache_close(psc_cache_map); 609 psc_cache_map = 0; 610 } 611 for (count = 0; /* see below */ ; count++) { 612 if (count >= 5) { 613 msg_fatal("fork: %m"); 614 } else if (event_server_drain() != 0) { 615 msg_warn("fork: %m"); 616 sleep(1); 617 continue; 618 } else { 619 return; 620 } 621 } 622 } 623 624 /* psc_service - handle new client connection */ 625 626 static void psc_service(VSTREAM *smtp_client_stream, 627 char *unused_service, 628 char **unused_argv) 629 { 630 631 /* 632 * For sanity, require that at least one of INET or INET6 is enabled. 633 * Otherwise, we can't look up interface information, and we can't 634 * convert names or addresses. 635 */ 636 if (inet_proto_info()->ai_family_list[0] == 0) 637 msg_fatal("all network protocols are disabled (%s = %s)", 638 VAR_INET_PROTOCOLS, var_inet_protocols); 639 640 /* 641 * This program handles all incoming connections, so it must not block. 642 * We use event-driven code for all operations that introduce latency. 643 * 644 * Note: instead of using VSTREAM-level timeouts, we enforce limits on the 645 * total amount of time to receive a complete SMTP command line. 646 */ 647 non_blocking(vstream_fileno(smtp_client_stream), NON_BLOCKING); 648 649 /* 650 * Look up the remote SMTP client address and port. 651 */ 652 psc_endpt_lookup(smtp_client_stream, psc_endpt_lookup_done); 653 } 654 655 /* psc_endpt_lookup_done - endpoint lookup completed */ 656 657 static void psc_endpt_lookup_done(int endpt_status, 658 VSTREAM *smtp_client_stream, 659 MAI_HOSTADDR_STR *smtp_client_addr, 660 MAI_SERVPORT_STR *smtp_client_port, 661 MAI_HOSTADDR_STR *smtp_server_addr, 662 MAI_SERVPORT_STR *smtp_server_port) 663 { 664 const char *myname = "psc_endpt_lookup_done"; 665 PSC_STATE *state; 666 const char *stamp_str; 667 int saved_flags; 668 669 /* 670 * Best effort - if this non-blocking write(2) fails, so be it. 671 */ 672 if (endpt_status < 0) { 673 (void) write(vstream_fileno(smtp_client_stream), 674 "421 4.3.2 No system resources\r\n", 675 sizeof("421 4.3.2 No system resources\r\n") - 1); 676 event_server_disconnect(smtp_client_stream); 677 return; 678 } 679 if (msg_verbose > 1) 680 msg_info("%s: sq=%d cq=%d connect from [%s]:%s", 681 myname, psc_post_queue_length, psc_check_queue_length, 682 smtp_client_addr->buf, smtp_client_port->buf); 683 684 msg_info("CONNECT from [%s]:%s to [%s]:%s", 685 smtp_client_addr->buf, smtp_client_port->buf, 686 smtp_server_addr->buf, smtp_server_port->buf); 687 688 /* 689 * Bundle up all the loose session pieces. This zeroes all flags and time 690 * stamps. 691 */ 692 state = psc_new_session_state(smtp_client_stream, smtp_client_addr->buf, 693 smtp_client_port->buf, 694 smtp_server_addr->buf, 695 smtp_server_port->buf); 696 697 /* 698 * Reply with 421 when the client has too many open connections. 699 */ 700 if (var_psc_cconn_limit > 0 701 && state->client_concurrency > var_psc_cconn_limit) { 702 msg_info("NOQUEUE: reject: CONNECT from [%s]:%s: too many connections", 703 state->smtp_client_addr, state->smtp_client_port); 704 PSC_DROP_SESSION_STATE(state, 705 "421 4.7.0 Error: too many connections\r\n"); 706 return; 707 } 708 709 /* 710 * Reply with 421 when we can't forward more connections. 711 */ 712 if (var_psc_post_queue_limit > 0 713 && psc_post_queue_length >= var_psc_post_queue_limit) { 714 msg_info("NOQUEUE: reject: CONNECT from [%s]:%s: all server ports busy", 715 state->smtp_client_addr, state->smtp_client_port); 716 PSC_DROP_SESSION_STATE(state, 717 "421 4.3.2 All server ports are busy\r\n"); 718 return; 719 } 720 721 /* 722 * The permanent white/blacklist has highest precedence. 723 */ 724 if (psc_acl != 0) { 725 switch (psc_acl_eval(state, psc_acl, VAR_PSC_ACL)) { 726 727 /* 728 * Permanently blacklisted. 729 */ 730 case PSC_ACL_ACT_BLACKLIST: 731 msg_info("BLACKLISTED [%s]:%s", PSC_CLIENT_ADDR_PORT(state)); 732 PSC_FAIL_SESSION_STATE(state, PSC_STATE_FLAG_BLIST_FAIL); 733 switch (psc_blist_action) { 734 case PSC_ACT_DROP: 735 PSC_DROP_SESSION_STATE(state, 736 "521 5.3.2 Service currently unavailable\r\n"); 737 return; 738 case PSC_ACT_ENFORCE: 739 PSC_ENFORCE_SESSION_STATE(state, 740 "550 5.3.2 Service currently unavailable\r\n"); 741 break; 742 case PSC_ACT_IGNORE: 743 PSC_UNFAIL_SESSION_STATE(state, PSC_STATE_FLAG_BLIST_FAIL); 744 745 /* 746 * Not: PSC_PASS_SESSION_STATE. Repeat this test the next 747 * time. 748 */ 749 break; 750 default: 751 msg_panic("%s: unknown blacklist action value %d", 752 myname, psc_blist_action); 753 } 754 break; 755 756 /* 757 * Permanently whitelisted. 758 */ 759 case PSC_ACL_ACT_WHITELIST: 760 msg_info("WHITELISTED [%s]:%s", PSC_CLIENT_ADDR_PORT(state)); 761 psc_conclude(state); 762 return; 763 764 /* 765 * Other: dunno (don't know) or error. 766 */ 767 default: 768 break; 769 } 770 } 771 772 /* 773 * The temporary whitelist (i.e. the postscreen cache) has the lowest 774 * precedence. This cache contains information about the results of prior 775 * tests. Whitelist the client when all enabled test results are still 776 * valid. 777 */ 778 if ((state->flags & PSC_STATE_MASK_ANY_FAIL) == 0 779 && state->client_info->concurrency == 1 780 && psc_cache_map != 0 781 && (stamp_str = psc_cache_lookup(psc_cache_map, state->smtp_client_addr)) != 0) { 782 saved_flags = state->flags; 783 psc_parse_tests(state, stamp_str, event_time()); 784 state->flags |= saved_flags; 785 if (msg_verbose) 786 msg_info("%s: cached + recent flags: %s", 787 myname, psc_print_state_flags(state->flags, myname)); 788 if ((state->flags & PSC_STATE_MASK_ANY_TODO_FAIL) == 0) { 789 msg_info("PASS OLD [%s]:%s", PSC_CLIENT_ADDR_PORT(state)); 790 psc_conclude(state); 791 return; 792 } 793 } else if (state->client_info->concurrency > 1) { 794 saved_flags = state->flags; 795 psc_todo_tests(state, event_time()); 796 state->flags |= saved_flags; 797 if (msg_verbose) 798 msg_info("%s: new + recent flags: %s", 799 myname, psc_print_state_flags(state->flags, myname)); 800 } else { 801 saved_flags = state->flags; 802 psc_new_tests(state); 803 state->flags |= saved_flags; 804 if (msg_verbose) 805 msg_info("%s: new + recent flags: %s", 806 myname, psc_print_state_flags(state->flags, myname)); 807 } 808 809 /* 810 * Don't whitelist clients that connect to backup MX addresses. Fail 811 * "closed" on error. 812 */ 813 if (addr_match_list_match(psc_wlist_if, smtp_server_addr->buf) == 0) { 814 state->flags |= (PSC_STATE_FLAG_WLIST_FAIL | PSC_STATE_FLAG_NOFORWARD); 815 msg_info("WHITELIST VETO [%s]:%s", PSC_CLIENT_ADDR_PORT(state)); 816 } 817 818 /* 819 * Reply with 421 when we can't analyze more connections. That also means 820 * no deep protocol tests when the noforward flag is raised. 821 */ 822 if (var_psc_pre_queue_limit > 0 823 && psc_check_queue_length - psc_post_queue_length 824 >= var_psc_pre_queue_limit) { 825 msg_info("reject: connect from [%s]:%s: all screening ports busy", 826 state->smtp_client_addr, state->smtp_client_port); 827 PSC_DROP_SESSION_STATE(state, 828 "421 4.3.2 All screening ports are busy\r\n"); 829 return; 830 } 831 832 /* 833 * If the client has no up-to-date results for some tests, do those tests 834 * first. Otherwise, skip the tests and hand off the connection. 835 */ 836 if (state->flags & PSC_STATE_MASK_EARLY_TODO) 837 psc_early_tests(state); 838 else if (state->flags & (PSC_STATE_MASK_SMTPD_TODO | PSC_STATE_FLAG_NOFORWARD)) 839 psc_smtpd_tests(state); 840 else 841 psc_conclude(state); 842 } 843 844 /* psc_cache_validator - validate one cache entry */ 845 846 static int psc_cache_validator(const char *client_addr, 847 const char *stamp_str, 848 void *unused_context) 849 { 850 PSC_STATE dummy; 851 PSC_CLIENT_INFO dummy_client_info; 852 853 /* 854 * This function is called by the cache cleanup pseudo thread. 855 * 856 * When an entry is removed from the cache, the client will be reported as 857 * "NEW" in the next session where it passes all tests again. To avoid 858 * silly logging we remove the cache entry only after all tests have 859 * expired longer ago than the cache retention time. 860 */ 861 dummy.client_info = &dummy_client_info; 862 psc_parse_tests(&dummy, stamp_str, event_time() - var_psc_cache_ret); 863 return ((dummy.flags & PSC_STATE_MASK_ANY_TODO) == 0); 864 } 865 866 /* pre_jail_init - pre-jail initialization */ 867 868 static void pre_jail_init(char *unused_name, char **unused_argv) 869 { 870 VSTRING *redirect; 871 872 /* 873 * Open read-only maps before dropping privilege, for consistency with 874 * other Postfix daemons. 875 */ 876 psc_acl_pre_jail_init(var_mynetworks, VAR_PSC_ACL); 877 if (*var_psc_acl) 878 psc_acl = psc_acl_parse(var_psc_acl, VAR_PSC_ACL); 879 /* Ignore smtpd_forbid_cmds lookup errors. Non-critical feature. */ 880 if (*var_psc_forbid_cmds) 881 psc_forbid_cmds = string_list_init(VAR_PSC_FORBID_CMDS, 882 MATCH_FLAG_RETURN, 883 var_psc_forbid_cmds); 884 if (*var_psc_dnsbl_reply) 885 psc_dnsbl_reply = dict_open(var_psc_dnsbl_reply, O_RDONLY, 886 DICT_FLAG_DUP_WARN); 887 888 /* 889 * Never, ever, get killed by a master signal, as that would corrupt the 890 * database when we're in the middle of an update. 891 */ 892 if (setsid() < 0) 893 msg_warn("setsid: %m"); 894 895 /* 896 * Security: don't create root-owned files that contain untrusted data. 897 * And don't create Postfix-owned files in root-owned directories, 898 * either. We want a correct relationship between (file or directory) 899 * ownership and (file or directory) content. To open files before going 900 * to jail, temporarily drop root privileges. 901 */ 902 SAVE_AND_SET_EUGID(var_owner_uid, var_owner_gid); 903 redirect = vstring_alloc(100); 904 905 /* 906 * Keep state in persistent external map. As a safety measure we sync the 907 * database on each update. This hurts on LINUX file systems that sync 908 * all dirty disk blocks whenever any application invokes fsync(). 909 * 910 * Start the cache maintenance pseudo thread after dropping privileges. 911 */ 912 #define PSC_DICT_OPEN_FLAGS (DICT_FLAG_DUP_REPLACE | DICT_FLAG_SYNC_UPDATE | \ 913 DICT_FLAG_OPEN_LOCK) 914 915 if (*var_psc_cache_map) 916 psc_cache_map = 917 dict_cache_open(data_redirect_map(redirect, var_psc_cache_map), 918 O_CREAT | O_RDWR, PSC_DICT_OPEN_FLAGS); 919 920 /* 921 * Clean up and restore privilege. 922 */ 923 vstring_free(redirect); 924 RESTORE_SAVED_EUGID(); 925 926 /* 927 * Initialize the dummy SMTP engine. 928 */ 929 psc_smtpd_pre_jail_init(); 930 } 931 932 /* pre_accept - see if tables have changed */ 933 934 static void pre_accept(char *unused_name, char **unused_argv) 935 { 936 static time_t last_event_time; 937 time_t new_event_time; 938 const char *name; 939 940 /* 941 * If some table has changed then stop accepting new connections. Don't 942 * check the tables more than once a second. 943 */ 944 new_event_time = event_time(); 945 if (new_event_time >= last_event_time + 1 946 && (name = dict_changed_name()) != 0) { 947 msg_info("table %s has changed - finishing in the background", name); 948 event_server_drain(); 949 } else { 950 last_event_time = new_event_time; 951 } 952 } 953 954 /* post_jail_init - post-jail initialization */ 955 956 static void post_jail_init(char *unused_name, char **unused_argv) 957 { 958 const NAME_CODE actions[] = { 959 PSC_NAME_ACT_DROP, PSC_ACT_DROP, 960 PSC_NAME_ACT_ENFORCE, PSC_ACT_ENFORCE, 961 PSC_NAME_ACT_IGNORE, PSC_ACT_IGNORE, 962 PSC_NAME_ACT_CONT, PSC_ACT_IGNORE, /* compatibility */ 963 0, -1, 964 }; 965 int cache_flags; 966 const char *tmp; 967 968 /* 969 * This routine runs after the skeleton code has entered the chroot jail. 970 * Prevent automatic process suicide after a limited number of client 971 * requests. It is OK to terminate after a limited amount of idle time. 972 */ 973 var_use_limit = 0; 974 975 /* 976 * Workaround for parameters whose values may contain "$", and that have 977 * a default of "$parametername". Not sure if it would be a good idea to 978 * always to this in the mail_conf_raw(3) module. 979 */ 980 if (*var_psc_rej_footer == '$' 981 && mail_conf_lookup(var_psc_rej_footer + 1)) { 982 tmp = mail_conf_eval_once(var_psc_rej_footer); 983 myfree(var_psc_rej_footer); 984 var_psc_rej_footer = mystrdup(tmp); 985 } 986 if (*var_psc_exp_filter == '$' 987 && mail_conf_lookup(var_psc_exp_filter + 1)) { 988 tmp = mail_conf_eval_once(var_psc_exp_filter); 989 myfree(var_psc_exp_filter); 990 var_psc_exp_filter = mystrdup(tmp); 991 } 992 993 /* 994 * Other one-time initialization. 995 */ 996 psc_temp = vstring_alloc(10); 997 vstring_sprintf(psc_temp, "%s/%s", MAIL_CLASS_PRIVATE, var_smtpd_service); 998 psc_smtpd_service_name = mystrdup(STR(psc_temp)); 999 psc_dnsbl_init(); 1000 psc_early_init(); 1001 psc_smtpd_init(); 1002 1003 if ((psc_blist_action = name_code(actions, NAME_CODE_FLAG_NONE, 1004 var_psc_blist_action)) < 0) 1005 msg_fatal("bad %s value: %s", VAR_PSC_BLIST_ACTION, 1006 var_psc_blist_action); 1007 if ((psc_dnsbl_action = name_code(actions, NAME_CODE_FLAG_NONE, 1008 var_psc_dnsbl_action)) < 0) 1009 msg_fatal("bad %s value: %s", VAR_PSC_DNSBL_ACTION, 1010 var_psc_dnsbl_action); 1011 if ((psc_pregr_action = name_code(actions, NAME_CODE_FLAG_NONE, 1012 var_psc_pregr_action)) < 0) 1013 msg_fatal("bad %s value: %s", VAR_PSC_PREGR_ACTION, 1014 var_psc_pregr_action); 1015 if ((psc_pipel_action = name_code(actions, NAME_CODE_FLAG_NONE, 1016 var_psc_pipel_action)) < 0) 1017 msg_fatal("bad %s value: %s", VAR_PSC_PIPEL_ACTION, 1018 var_psc_pipel_action); 1019 if ((psc_nsmtp_action = name_code(actions, NAME_CODE_FLAG_NONE, 1020 var_psc_nsmtp_action)) < 0) 1021 msg_fatal("bad %s value: %s", VAR_PSC_NSMTP_ACTION, 1022 var_psc_nsmtp_action); 1023 if ((psc_barlf_action = name_code(actions, NAME_CODE_FLAG_NONE, 1024 var_psc_barlf_action)) < 0) 1025 msg_fatal("bad %s value: %s", VAR_PSC_BARLF_ACTION, 1026 var_psc_barlf_action); 1027 /* Fail "closed" on error. */ 1028 psc_wlist_if = addr_match_list_init(VAR_PSC_WLIST_IF, MATCH_FLAG_RETURN, 1029 var_psc_wlist_if); 1030 1031 /* 1032 * Start the cache maintenance pseudo thread last. Early cleanup makes 1033 * verbose logging more informative (we get positive confirmation that 1034 * the cleanup thread runs). 1035 */ 1036 cache_flags = DICT_CACHE_FLAG_STATISTICS; 1037 if (msg_verbose > 1) 1038 cache_flags |= DICT_CACHE_FLAG_VERBOSE; 1039 if (psc_cache_map != 0 && var_psc_cache_scan > 0) 1040 dict_cache_control(psc_cache_map, 1041 CA_DICT_CACHE_CTL_FLAGS(cache_flags), 1042 CA_DICT_CACHE_CTL_INTERVAL(var_psc_cache_scan), 1043 CA_DICT_CACHE_CTL_VALIDATOR(psc_cache_validator), 1044 CA_DICT_CACHE_CTL_CONTEXT((void *) 0), 1045 CA_DICT_CACHE_CTL_END); 1046 1047 /* 1048 * Pre-compute the minimal and maximal TTL. 1049 */ 1050 psc_min_ttl = 1051 PSC_MIN(PSC_MIN(var_psc_pregr_ttl, var_psc_dnsbl_min_ttl), 1052 PSC_MIN(PSC_MIN(var_psc_pipel_ttl, var_psc_nsmtp_ttl), 1053 var_psc_barlf_ttl)); 1054 1055 /* 1056 * Pre-compute the stress and normal command time limits. 1057 */ 1058 mail_conf_update(VAR_STRESS, "yes"); 1059 psc_stress_cmd_time_limit = 1060 get_mail_conf_time(VAR_PSC_CMD_TIME, DEF_PSC_CMD_TIME, 1, 0); 1061 psc_stress_greet_wait = 1062 get_mail_conf_time(VAR_PSC_GREET_WAIT, DEF_PSC_GREET_WAIT, 1, 0); 1063 1064 mail_conf_update(VAR_STRESS, ""); 1065 psc_normal_cmd_time_limit = 1066 get_mail_conf_time(VAR_PSC_CMD_TIME, DEF_PSC_CMD_TIME, 1, 0); 1067 psc_normal_greet_wait = 1068 get_mail_conf_time(VAR_PSC_GREET_WAIT, DEF_PSC_GREET_WAIT, 1, 0); 1069 1070 psc_lowat_check_queue_length = .7 * var_psc_pre_queue_limit; 1071 psc_hiwat_check_queue_length = .9 * var_psc_pre_queue_limit; 1072 if (msg_verbose) 1073 msg_info(VAR_PSC_CMD_TIME ": stress=%d normal=%d lowat=%d hiwat=%d", 1074 psc_stress_cmd_time_limit, psc_normal_cmd_time_limit, 1075 psc_lowat_check_queue_length, psc_hiwat_check_queue_length); 1076 1077 if (psc_lowat_check_queue_length == 0) 1078 msg_panic("compiler error: 0.7 * %d = %d", var_psc_pre_queue_limit, 1079 psc_lowat_check_queue_length); 1080 if (psc_hiwat_check_queue_length == 0) 1081 msg_panic("compiler error: 0.9 * %d = %d", var_psc_pre_queue_limit, 1082 psc_hiwat_check_queue_length); 1083 1084 /* 1085 * Per-client concurrency. 1086 */ 1087 psc_client_concurrency = htable_create(var_psc_pre_queue_limit); 1088 } 1089 1090 MAIL_VERSION_STAMP_DECLARE; 1091 1092 /* main - pass control to the multi-threaded skeleton */ 1093 1094 int main(int argc, char **argv) 1095 { 1096 1097 /* 1098 * List smtpd(8) parameters before any postscreen(8) parameters that have 1099 * defaults dependencies on them. 1100 */ 1101 static const CONFIG_STR_TABLE str_table[] = { 1102 VAR_SMTPD_SERVICE, DEF_SMTPD_SERVICE, &var_smtpd_service, 1, 0, 1103 VAR_SMTPD_BANNER, DEF_SMTPD_BANNER, &var_smtpd_banner, 1, 0, 1104 VAR_SMTPD_FORBID_CMDS, DEF_SMTPD_FORBID_CMDS, &var_smtpd_forbid_cmds, 0, 0, 1105 VAR_SMTPD_EHLO_DIS_WORDS, DEF_SMTPD_EHLO_DIS_WORDS, &var_smtpd_ehlo_dis_words, 0, 0, 1106 VAR_SMTPD_EHLO_DIS_MAPS, DEF_SMTPD_EHLO_DIS_MAPS, &var_smtpd_ehlo_dis_maps, 0, 0, 1107 VAR_SMTPD_TLS_LEVEL, DEF_SMTPD_TLS_LEVEL, &var_smtpd_tls_level, 0, 0, 1108 VAR_SMTPD_CMD_FILTER, DEF_SMTPD_CMD_FILTER, &var_smtpd_cmd_filter, 0, 0, 1109 VAR_PSC_CACHE_MAP, DEF_PSC_CACHE_MAP, &var_psc_cache_map, 0, 0, 1110 VAR_PSC_PREGR_BANNER, DEF_PSC_PREGR_BANNER, &var_psc_pregr_banner, 0, 0, 1111 VAR_PSC_PREGR_ACTION, DEF_PSC_PREGR_ACTION, &var_psc_pregr_action, 1, 0, 1112 VAR_PSC_DNSBL_SITES, DEF_PSC_DNSBL_SITES, &var_psc_dnsbl_sites, 0, 0, 1113 VAR_PSC_DNSBL_ACTION, DEF_PSC_DNSBL_ACTION, &var_psc_dnsbl_action, 1, 0, 1114 VAR_PSC_PIPEL_ACTION, DEF_PSC_PIPEL_ACTION, &var_psc_pipel_action, 1, 0, 1115 VAR_PSC_NSMTP_ACTION, DEF_PSC_NSMTP_ACTION, &var_psc_nsmtp_action, 1, 0, 1116 VAR_PSC_BARLF_ACTION, DEF_PSC_BARLF_ACTION, &var_psc_barlf_action, 1, 0, 1117 VAR_PSC_ACL, DEF_PSC_ACL, &var_psc_acl, 0, 0, 1118 VAR_PSC_BLIST_ACTION, DEF_PSC_BLIST_ACTION, &var_psc_blist_action, 1, 0, 1119 VAR_PSC_FORBID_CMDS, DEF_PSC_FORBID_CMDS, &var_psc_forbid_cmds, 0, 0, 1120 VAR_PSC_EHLO_DIS_WORDS, DEF_PSC_EHLO_DIS_WORDS, &var_psc_ehlo_dis_words, 0, 0, 1121 VAR_PSC_EHLO_DIS_MAPS, DEF_PSC_EHLO_DIS_MAPS, &var_psc_ehlo_dis_maps, 0, 0, 1122 VAR_PSC_DNSBL_REPLY, DEF_PSC_DNSBL_REPLY, &var_psc_dnsbl_reply, 0, 0, 1123 VAR_PSC_TLS_LEVEL, DEF_PSC_TLS_LEVEL, &var_psc_tls_level, 0, 0, 1124 VAR_PSC_CMD_FILTER, DEF_PSC_CMD_FILTER, &var_psc_cmd_filter, 0, 0, 1125 VAR_DNSBLOG_SERVICE, DEF_DNSBLOG_SERVICE, &var_dnsblog_service, 1, 0, 1126 VAR_TLSPROXY_SERVICE, DEF_TLSPROXY_SERVICE, &var_tlsproxy_service, 1, 0, 1127 VAR_PSC_WLIST_IF, DEF_PSC_WLIST_IF, &var_psc_wlist_if, 0, 0, 1128 VAR_PSC_UPROXY_PROTO, DEF_PSC_UPROXY_PROTO, &var_psc_uproxy_proto, 0, 0, 1129 0, 1130 }; 1131 static const CONFIG_INT_TABLE int_table[] = { 1132 VAR_PSC_DNSBL_THRESH, DEF_PSC_DNSBL_THRESH, &var_psc_dnsbl_thresh, 0, 0, 1133 VAR_PSC_DNSBL_WTHRESH, DEF_PSC_DNSBL_WTHRESH, &var_psc_dnsbl_wthresh, 0, 0, 1134 VAR_PSC_CMD_COUNT, DEF_PSC_CMD_COUNT, &var_psc_cmd_count, 1, 0, 1135 VAR_SMTPD_CCONN_LIMIT, DEF_SMTPD_CCONN_LIMIT, &var_smtpd_cconn_limit, 0, 0, 1136 0, 1137 }; 1138 static const CONFIG_NINT_TABLE nint_table[] = { 1139 VAR_PSC_POST_QLIMIT, DEF_PSC_POST_QLIMIT, &var_psc_post_queue_limit, 5, 0, 1140 VAR_PSC_PRE_QLIMIT, DEF_PSC_PRE_QLIMIT, &var_psc_pre_queue_limit, 10, 0, 1141 VAR_PSC_CCONN_LIMIT, DEF_PSC_CCONN_LIMIT, &var_psc_cconn_limit, 0, 0, 1142 0, 1143 }; 1144 static const CONFIG_TIME_TABLE time_table[] = { 1145 VAR_PSC_GREET_WAIT, DEF_PSC_GREET_WAIT, &var_psc_greet_wait, 1, 0, 1146 VAR_PSC_PREGR_TTL, DEF_PSC_PREGR_TTL, &var_psc_pregr_ttl, 1, 0, 1147 VAR_PSC_DNSBL_MIN_TTL, DEF_PSC_DNSBL_MIN_TTL, &var_psc_dnsbl_min_ttl, 1, 0, 1148 VAR_PSC_DNSBL_MAX_TTL, DEF_PSC_DNSBL_MAX_TTL, &var_psc_dnsbl_max_ttl, 1, 0, 1149 VAR_PSC_PIPEL_TTL, DEF_PSC_PIPEL_TTL, &var_psc_pipel_ttl, 1, 0, 1150 VAR_PSC_NSMTP_TTL, DEF_PSC_NSMTP_TTL, &var_psc_nsmtp_ttl, 1, 0, 1151 VAR_PSC_BARLF_TTL, DEF_PSC_BARLF_TTL, &var_psc_barlf_ttl, 1, 0, 1152 VAR_PSC_CACHE_RET, DEF_PSC_CACHE_RET, &var_psc_cache_ret, 1, 0, 1153 VAR_PSC_CACHE_SCAN, DEF_PSC_CACHE_SCAN, &var_psc_cache_scan, 0, 0, 1154 VAR_PSC_WATCHDOG, DEF_PSC_WATCHDOG, &var_psc_watchdog, 10, 0, 1155 VAR_PSC_UPROXY_TMOUT, DEF_PSC_UPROXY_TMOUT, &var_psc_uproxy_tmout, 1, 0, 1156 VAR_PSC_DNSBL_TMOUT, DEF_PSC_DNSBL_TMOUT, &var_psc_dnsbl_tmout, 1, 0, 1157 1158 0, 1159 }; 1160 static const CONFIG_BOOL_TABLE bool_table[] = { 1161 VAR_HELO_REQUIRED, DEF_HELO_REQUIRED, &var_helo_required, 1162 VAR_DISABLE_VRFY_CMD, DEF_DISABLE_VRFY_CMD, &var_disable_vrfy_cmd, 1163 VAR_SMTPD_USE_TLS, DEF_SMTPD_USE_TLS, &var_smtpd_use_tls, 1164 VAR_SMTPD_ENFORCE_TLS, DEF_SMTPD_ENFORCE_TLS, &var_smtpd_enforce_tls, 1165 VAR_PSC_PIPEL_ENABLE, DEF_PSC_PIPEL_ENABLE, &var_psc_pipel_enable, 1166 VAR_PSC_NSMTP_ENABLE, DEF_PSC_NSMTP_ENABLE, &var_psc_nsmtp_enable, 1167 VAR_PSC_BARLF_ENABLE, DEF_PSC_BARLF_ENABLE, &var_psc_barlf_enable, 1168 0, 1169 }; 1170 static const CONFIG_RAW_TABLE raw_table[] = { 1171 VAR_PSC_CMD_TIME, DEF_PSC_CMD_TIME, &var_psc_cmd_time, 1, 0, 1172 VAR_SMTPD_REJ_FOOTER, DEF_SMTPD_REJ_FOOTER, &var_smtpd_rej_footer, 0, 0, 1173 VAR_PSC_REJ_FOOTER, DEF_PSC_REJ_FOOTER, &var_psc_rej_footer, 0, 0, 1174 VAR_SMTPD_EXP_FILTER, DEF_SMTPD_EXP_FILTER, &var_smtpd_exp_filter, 1, 0, 1175 VAR_PSC_EXP_FILTER, DEF_PSC_EXP_FILTER, &var_psc_exp_filter, 1, 0, 1176 0, 1177 }; 1178 static const CONFIG_NBOOL_TABLE nbool_table[] = { 1179 VAR_PSC_HELO_REQUIRED, DEF_PSC_HELO_REQUIRED, &var_psc_helo_required, 1180 VAR_PSC_DISABLE_VRFY, DEF_PSC_DISABLE_VRFY, &var_psc_disable_vrfy, 1181 VAR_PSC_USE_TLS, DEF_PSC_USE_TLS, &var_psc_use_tls, 1182 VAR_PSC_ENFORCE_TLS, DEF_PSC_ENFORCE_TLS, &var_psc_enforce_tls, 1183 0, 1184 }; 1185 1186 /* 1187 * Fingerprint executables and core dumps. 1188 */ 1189 MAIL_VERSION_STAMP_ALLOCATE; 1190 1191 event_server_main(argc, argv, psc_service, 1192 CA_MAIL_SERVER_STR_TABLE(str_table), 1193 CA_MAIL_SERVER_INT_TABLE(int_table), 1194 CA_MAIL_SERVER_NINT_TABLE(nint_table), 1195 CA_MAIL_SERVER_TIME_TABLE(time_table), 1196 CA_MAIL_SERVER_BOOL_TABLE(bool_table), 1197 CA_MAIL_SERVER_RAW_TABLE(raw_table), 1198 CA_MAIL_SERVER_NBOOL_TABLE(nbool_table), 1199 CA_MAIL_SERVER_PRE_INIT(pre_jail_init), 1200 CA_MAIL_SERVER_POST_INIT(post_jail_init), 1201 CA_MAIL_SERVER_PRE_ACCEPT(pre_accept), 1202 CA_MAIL_SERVER_SOLITARY, 1203 CA_MAIL_SERVER_SLOW_EXIT(psc_drain), 1204 CA_MAIL_SERVER_EXIT(psc_dump), 1205 CA_MAIL_SERVER_WATCHDOG(&var_psc_watchdog), 1206 0); 1207 } 1208