xref: /netbsd-src/external/ibm-public/postfix/dist/src/proxymap/proxymap.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: proxymap.c,v 1.2 2017/02/14 01:16:47 christos Exp $	*/
2 
3 /*++
4 /* NAME
5 /*	proxymap 8
6 /* SUMMARY
7 /*	Postfix lookup table proxy server
8 /* SYNOPSIS
9 /*	\fBproxymap\fR [generic Postfix daemon options]
10 /* DESCRIPTION
11 /*	The \fBproxymap\fR(8) server provides read-only or read-write
12 /*	table lookup service to Postfix processes. These services are
13 /*	implemented with distinct service names: \fBproxymap\fR and
14 /*	\fBproxywrite\fR, respectively. The purpose of these services is:
15 /* .IP \(bu
16 /*	To overcome chroot restrictions. For example, a chrooted SMTP
17 /*	server needs access to the system passwd file in order to
18 /*	reject mail for non-existent local addresses, but it is not
19 /*	practical to maintain a copy of the passwd file in the chroot
20 /*	jail.  The solution:
21 /* .sp
22 /* .nf
23 /*	local_recipient_maps =
24 /*	    proxy:unix:passwd.byname $alias_maps
25 /* .fi
26 /* .IP \(bu
27 /*	To consolidate the number of open lookup tables by sharing
28 /*	one open table among multiple processes. For example, making
29 /*	mysql connections from every Postfix daemon process results
30 /*	in "too many connections" errors. The solution:
31 /* .sp
32 /* .nf
33 /*	virtual_alias_maps =
34 /*	    proxy:mysql:/etc/postfix/virtual_alias.cf
35 /* .fi
36 /* .sp
37 /*	The total number of connections is limited by the number of
38 /*	proxymap server processes.
39 /* .IP \(bu
40 /*	To provide single-updater functionality for lookup tables
41 /*	that do not reliably support multiple writers (i.e. all
42 /*	file-based tables).
43 /* .PP
44 /*	The \fBproxymap\fR(8) server implements the following requests:
45 /* .IP "\fBopen\fR \fImaptype:mapname flags\fR"
46 /*	Open the table with type \fImaptype\fR and name \fImapname\fR,
47 /*	as controlled by \fIflags\fR. The reply includes the \fImaptype\fR
48 /*	dependent flags (to distinguish a fixed string table from a regular
49 /*	expression table).
50 /* .IP "\fBlookup\fR \fImaptype:mapname flags key\fR"
51 /*	Look up the data stored under the requested key.
52 /*	The reply is the request completion status code and
53 /*	the lookup result value.
54 /*	The \fImaptype:mapname\fR and \fIflags\fR are the same
55 /*	as with the \fBopen\fR request.
56 /* .IP "\fBupdate\fR \fImaptype:mapname flags key value\fR"
57 /*	Update the data stored under the requested key.
58 /*	The reply is the request completion status code.
59 /*	The \fImaptype:mapname\fR and \fIflags\fR are the same
60 /*	as with the \fBopen\fR request.
61 /* .sp
62 /*	To implement single-updater maps, specify a process limit
63 /*	of 1 in the master.cf file entry for the \fBproxywrite\fR
64 /*	service.
65 /* .sp
66 /*	This request is supported in Postfix 2.5 and later.
67 /* .IP "\fBdelete\fR \fImaptype:mapname flags key\fR"
68 /*	Delete the data stored under the requested key.
69 /*	The reply is the request completion status code.
70 /*	The \fImaptype:mapname\fR and \fIflags\fR are the same
71 /*	as with the \fBopen\fR request.
72 /* .sp
73 /*	This request is supported in Postfix 2.5 and later.
74 /* .IP "\fBsequence\fR \fImaptype:mapname flags function\fR"
75 /*	Iterate over the specified database. The \fIfunction\fR
76 /*	is one of DICT_SEQ_FUN_FIRST or DICT_SEQ_FUN_NEXT.
77 /*	The reply is the request completion status code and
78 /*	a lookup key and result value, if found.
79 /* .sp
80 /*	This request is supported in Postfix 2.9 and later.
81 /* .PP
82 /*	The request completion status is one of OK, RETRY, NOKEY
83 /*	(lookup failed because the key was not found), BAD (malformed
84 /*	request) or DENY (the table is not approved for proxy read
85 /*	or update access).
86 /*
87 /*	There is no \fBclose\fR command, nor are tables implicitly closed
88 /*	when a client disconnects. The purpose is to share tables among
89 /*	multiple client processes.
90 /* SERVER PROCESS MANAGEMENT
91 /* .ad
92 /* .fi
93 /*	\fBproxymap\fR(8) servers run under control by the Postfix
94 /*	\fBmaster\fR(8)
95 /*	server.  Each server can handle multiple simultaneous connections.
96 /*	When all servers are busy while a client connects, the \fBmaster\fR(8)
97 /*	creates a new \fBproxymap\fR(8) server process, provided that the
98 /*	process limit is not exceeded.
99 /*	Each server terminates after serving at least \fB$max_use\fR clients
100 /*	or after \fB$max_idle\fR seconds of idle time.
101 /* SECURITY
102 /* .ad
103 /* .fi
104 /*	The \fBproxymap\fR(8) server opens only tables that are
105 /*	approved via the \fBproxy_read_maps\fR or \fBproxy_write_maps\fR
106 /*	configuration parameters, does not talk to
107 /*	users, and can run at fixed low privilege, chrooted or not.
108 /*	However, running the proxymap server chrooted severely limits
109 /*	usability, because it can open only chrooted tables.
110 /*
111 /*	The \fBproxymap\fR(8) server is not a trusted daemon process, and must
112 /*	not be used to look up sensitive information such as UNIX user or
113 /*	group IDs, mailbox file/directory names or external commands.
114 /*
115 /*	In Postfix version 2.2 and later, the proxymap client recognizes
116 /*	requests to access a table for security-sensitive purposes,
117 /*	and opens the table directly. This allows the same main.cf
118 /*	setting to be used by sensitive and non-sensitive processes.
119 /*
120 /*	Postfix-writable data files should be stored under a dedicated
121 /*	directory that is writable only by the Postfix mail system,
122 /*	such as the Postfix-owned \fBdata_directory\fR.
123 /*
124 /*	In particular, Postfix-writable files should never exist
125 /*	in root-owned directories. That would open up a particular
126 /*	type of security hole where ownership of a file or directory
127 /*	does not match the provider of its content.
128 /* DIAGNOSTICS
129 /*	Problems and transactions are logged to \fBsyslogd\fR(8).
130 /* BUGS
131 /*	The \fBproxymap\fR(8) server provides service to multiple clients,
132 /*	and must therefore not be used for tables that have high-latency
133 /*	lookups.
134 /*
135 /*	The \fBproxymap\fR(8) read-write service does not explicitly
136 /*	close lookup tables (even if it did, this could not be relied on,
137 /*	because the process may be terminated between table updates).
138 /*	The read-write service should therefore not be used with tables that
139 /*	leave persistent storage in an inconsistent state between
140 /*	updates (for example, CDB). Tables that support "sync on
141 /*	update" should be safe (for example, Berkeley DB) as should
142 /*	tables that are implemented by a real DBMS.
143 /* CONFIGURATION PARAMETERS
144 /* .ad
145 /* .fi
146 /*	On busy mail systems a long time may pass before
147 /*	\fBproxymap\fR(8) relevant
148 /*	changes to \fBmain.cf\fR are picked up. Use the command
149 /*	"\fBpostfix reload\fR" to speed up a change.
150 /*
151 /*	The text below provides only a parameter summary. See
152 /*	\fBpostconf\fR(5) for more details including examples.
153 /* .IP "\fBconfig_directory (see 'postconf -d' output)\fR"
154 /*	The default location of the Postfix main.cf and master.cf
155 /*	configuration files.
156 /* .IP "\fBdata_directory (see 'postconf -d' output)\fR"
157 /*	The directory with Postfix-writable data files (for example:
158 /*	caches, pseudo-random numbers).
159 /* .IP "\fBdaemon_timeout (18000s)\fR"
160 /*	How much time a Postfix daemon process may take to handle a
161 /*	request before it is terminated by a built-in watchdog timer.
162 /* .IP "\fBipc_timeout (3600s)\fR"
163 /*	The time limit for sending or receiving information over an internal
164 /*	communication channel.
165 /* .IP "\fBmax_idle (100s)\fR"
166 /*	The maximum amount of time that an idle Postfix daemon process waits
167 /*	for an incoming connection before terminating voluntarily.
168 /* .IP "\fBmax_use (100)\fR"
169 /*	The maximal number of incoming connections that a Postfix daemon
170 /*	process will service before terminating voluntarily.
171 /* .IP "\fBprocess_id (read-only)\fR"
172 /*	The process ID of a Postfix command or daemon process.
173 /* .IP "\fBprocess_name (read-only)\fR"
174 /*	The process name of a Postfix command or daemon process.
175 /* .IP "\fBproxy_read_maps (see 'postconf -d' output)\fR"
176 /*	The lookup tables that the \fBproxymap\fR(8) server is allowed to
177 /*	access for the read-only service.
178 /* .PP
179 /*	Available in Postfix 2.5 and later:
180 /* .IP "\fBdata_directory (see 'postconf -d' output)\fR"
181 /*	The directory with Postfix-writable data files (for example:
182 /*	caches, pseudo-random numbers).
183 /* .IP "\fBproxy_write_maps (see 'postconf -d' output)\fR"
184 /*	The lookup tables that the \fBproxymap\fR(8) server is allowed to
185 /*	access for the read-write service.
186 /* SEE ALSO
187 /*	postconf(5), configuration parameters
188 /*	master(5), generic daemon options
189 /* README FILES
190 /* .ad
191 /* .fi
192 /*	Use "\fBpostconf readme_directory\fR" or
193 /*	"\fBpostconf html_directory\fR" to locate this information.
194 /* .na
195 /* .nf
196 /*	DATABASE_README, Postfix lookup table overview
197 /* LICENSE
198 /* .ad
199 /* .fi
200 /*	The Secure Mailer license must be distributed with this software.
201 /* HISTORY
202 /* .ad
203 /* .fi
204 /*	The proxymap service was introduced with Postfix 2.0.
205 /* AUTHOR(S)
206 /*	Wietse Venema
207 /*	IBM T.J. Watson Research
208 /*	P.O. Box 704
209 /*	Yorktown Heights, NY 10598, USA
210 /*
211 /*	Wietse Venema
212 /*	Google, Inc.
213 /*	111 8th Avenue
214 /*	New York, NY 10011, USA
215 /*--*/
216 
217 /* System library. */
218 
219 #include <sys_defs.h>
220 #include <string.h>
221 #include <stdlib.h>
222 #include <unistd.h>
223 
224 /* Utility library. */
225 
226 #include <msg.h>
227 #include <mymalloc.h>
228 #include <vstring.h>
229 #include <htable.h>
230 #include <stringops.h>
231 #include <dict.h>
232 
233 /* Global library. */
234 
235 #include <mail_conf.h>
236 #include <mail_params.h>
237 #include <mail_version.h>
238 #include <mail_proto.h>
239 #include <dict_proxy.h>
240 
241 /* Server skeleton. */
242 
243 #include <mail_server.h>
244 
245 /* Application-specific. */
246 
247  /*
248   * XXX All but the last are needed here so that $name expansion dependencies
249   * aren't too broken. The fix is to gather all parameter default settings in
250   * one place.
251   */
252 char   *var_alias_maps;
253 char   *var_local_rcpt_maps;
254 char   *var_virt_alias_maps;
255 char   *var_virt_alias_doms;
256 char   *var_virt_mailbox_maps;
257 char   *var_virt_mailbox_doms;
258 char   *var_relay_rcpt_maps;
259 char   *var_relay_domains;
260 char   *var_canonical_maps;
261 char   *var_send_canon_maps;
262 char   *var_rcpt_canon_maps;
263 char   *var_relocated_maps;
264 char   *var_transport_maps;
265 char   *var_verify_map;
266 char   *var_smtpd_snd_auth_maps;
267 char   *var_psc_cache_map;
268 char   *var_proxy_read_maps;
269 char   *var_proxy_write_maps;
270 
271  /*
272   * The pre-approved, pre-parsed list of maps.
273   */
274 static HTABLE *proxy_auth_maps;
275 
276  /*
277   * Shared and static to reduce memory allocation overhead.
278   */
279 static VSTRING *request;
280 static VSTRING *request_map;
281 static VSTRING *request_key;
282 static VSTRING *request_value;
283 static VSTRING *map_type_name_flags;
284 
285  /*
286   * Are we a proxy writer or not?
287   */
288 static int proxy_writer;
289 
290  /*
291   * Silly little macros.
292   */
293 #define STR(x)			vstring_str(x)
294 #define VSTREQ(x,y)		(strcmp(STR(x),y) == 0)
295 
296 /* proxy_map_find - look up or open table */
297 
298 static DICT *proxy_map_find(const char *map_type_name, int request_flags,
299 			            int *statp)
300 {
301     DICT   *dict;
302 
303 #define PROXY_COLON	DICT_TYPE_PROXY ":"
304 #define PROXY_COLON_LEN	(sizeof(PROXY_COLON) - 1)
305 #define READ_OPEN_FLAGS	O_RDONLY
306 #define WRITE_OPEN_FLAGS (O_RDWR | O_CREAT)
307 
308     /*
309      * Canonicalize the map name. If the map is not on the approved list,
310      * deny the request.
311      */
312 #define PROXY_MAP_FIND_ERROR_RETURN(x)  { *statp = (x); return (0); }
313 
314     while (strncmp(map_type_name, PROXY_COLON, PROXY_COLON_LEN) == 0)
315 	map_type_name += PROXY_COLON_LEN;
316     /* XXX The following breaks with maps that have ':' in their name. */
317     if (strchr(map_type_name, ':') == 0)
318 	PROXY_MAP_FIND_ERROR_RETURN(PROXY_STAT_BAD);
319     if (htable_locate(proxy_auth_maps, map_type_name) == 0) {
320 	msg_warn("request for unapproved table: \"%s\"", map_type_name);
321 	msg_warn("to approve this table for %s access, list %s:%s in %s:%s",
322 		 proxy_writer == 0 ? "read-only" : "read-write",
323 		 DICT_TYPE_PROXY, map_type_name, MAIN_CONF_FILE,
324 		 proxy_writer == 0 ? VAR_PROXY_READ_MAPS :
325 		 VAR_PROXY_WRITE_MAPS);
326 	PROXY_MAP_FIND_ERROR_RETURN(PROXY_STAT_DENY);
327     }
328 
329     /*
330      * Open one instance of a map for each combination of name+flags.
331      *
332      * Assume that a map instance can be shared among clients with different
333      * paranoia flag settings and with different map lookup flag settings.
334      *
335      * XXX The open() flags are passed implicitly, via the selection of the
336      * service name. For a more sophisticated interface, appropriate subsets
337      * of open() flags should be received directly from the client.
338      */
339     vstring_sprintf(map_type_name_flags, "%s:%s", map_type_name,
340 		    dict_flags_str(request_flags & DICT_FLAG_INST_MASK));
341     if (msg_verbose)
342 	msg_info("proxy_map_find: %s", STR(map_type_name_flags));
343     if ((dict = dict_handle(STR(map_type_name_flags))) == 0) {
344 	dict = dict_open(map_type_name, proxy_writer ?
345 			 WRITE_OPEN_FLAGS : READ_OPEN_FLAGS,
346 			 request_flags);
347 	if (dict == 0)
348 	    msg_panic("proxy_map_find: dict_open null result");
349 	dict_register(STR(map_type_name_flags), dict);
350     }
351     dict->error = 0;
352     return (dict);
353 }
354 
355 /* proxymap_sequence_service - remote sequence service */
356 
357 static void proxymap_sequence_service(VSTREAM *client_stream)
358 {
359     int     request_flags;
360     DICT   *dict;
361     int     request_func;
362     const char *reply_key;
363     const char *reply_value;
364     int     dict_status;
365     int     reply_status;
366 
367     /*
368      * Process the request.
369      */
370     if (attr_scan(client_stream, ATTR_FLAG_STRICT,
371 		  RECV_ATTR_STR(MAIL_ATTR_TABLE, request_map),
372 		  RECV_ATTR_INT(MAIL_ATTR_FLAGS, &request_flags),
373 		  RECV_ATTR_INT(MAIL_ATTR_FUNC, &request_func),
374 		  ATTR_TYPE_END) != 3
375 	|| (request_func != DICT_SEQ_FUN_FIRST
376 	    && request_func != DICT_SEQ_FUN_NEXT)) {
377 	reply_status = PROXY_STAT_BAD;
378 	reply_key = reply_value = "";
379     } else if ((dict = proxy_map_find(STR(request_map), request_flags,
380 				      &reply_status)) == 0) {
381 	reply_key = reply_value = "";
382     } else {
383 	dict->flags = ((dict->flags & ~DICT_FLAG_RQST_MASK)
384 		       | (request_flags & DICT_FLAG_RQST_MASK));
385 	dict_status = dict_seq(dict, request_func, &reply_key, &reply_value);
386 	if (dict_status == 0) {
387 	    reply_status = PROXY_STAT_OK;
388 	} else if (dict->error == 0) {
389 	    reply_status = PROXY_STAT_NOKEY;
390 	    reply_key = reply_value = "";
391 	} else {
392 	    reply_status = (dict->error == DICT_ERR_RETRY ?
393 			    PROXY_STAT_RETRY : PROXY_STAT_CONFIG);
394 	    reply_key = reply_value = "";
395 	}
396     }
397 
398     /*
399      * Respond to the client.
400      */
401     attr_print(client_stream, ATTR_FLAG_NONE,
402 	       SEND_ATTR_INT(MAIL_ATTR_STATUS, reply_status),
403 	       SEND_ATTR_STR(MAIL_ATTR_KEY, reply_key),
404 	       SEND_ATTR_STR(MAIL_ATTR_VALUE, reply_value),
405 	       ATTR_TYPE_END);
406 }
407 
408 /* proxymap_lookup_service - remote lookup service */
409 
410 static void proxymap_lookup_service(VSTREAM *client_stream)
411 {
412     int     request_flags;
413     DICT   *dict;
414     const char *reply_value;
415     int     reply_status;
416 
417     /*
418      * Process the request.
419      */
420     if (attr_scan(client_stream, ATTR_FLAG_STRICT,
421 		  RECV_ATTR_STR(MAIL_ATTR_TABLE, request_map),
422 		  RECV_ATTR_INT(MAIL_ATTR_FLAGS, &request_flags),
423 		  RECV_ATTR_STR(MAIL_ATTR_KEY, request_key),
424 		  ATTR_TYPE_END) != 3) {
425 	reply_status = PROXY_STAT_BAD;
426 	reply_value = "";
427     } else if ((dict = proxy_map_find(STR(request_map), request_flags,
428 				      &reply_status)) == 0) {
429 	reply_value = "";
430     } else if (dict->flags = ((dict->flags & ~DICT_FLAG_RQST_MASK)
431 			      | (request_flags & DICT_FLAG_RQST_MASK)),
432 	       (reply_value = dict_get(dict, STR(request_key))) != 0) {
433 	reply_status = PROXY_STAT_OK;
434     } else if (dict->error == 0) {
435 	reply_status = PROXY_STAT_NOKEY;
436 	reply_value = "";
437     } else {
438 	reply_status = (dict->error == DICT_ERR_RETRY ?
439 			PROXY_STAT_RETRY : PROXY_STAT_CONFIG);
440 	reply_value = "";
441     }
442 
443     /*
444      * Respond to the client.
445      */
446     attr_print(client_stream, ATTR_FLAG_NONE,
447 	       SEND_ATTR_INT(MAIL_ATTR_STATUS, reply_status),
448 	       SEND_ATTR_STR(MAIL_ATTR_VALUE, reply_value),
449 	       ATTR_TYPE_END);
450 }
451 
452 /* proxymap_update_service - remote update service */
453 
454 static void proxymap_update_service(VSTREAM *client_stream)
455 {
456     int     request_flags;
457     DICT   *dict;
458     int     dict_status;
459     int     reply_status;
460 
461     /*
462      * Process the request.
463      *
464      * XXX We don't close maps, so we must turn on synchronous update to ensure
465      * that the on-disk data is in a consistent state between updates.
466      *
467      * XXX We ignore duplicates, because the proxymap server would abort
468      * otherwise.
469      */
470     if (attr_scan(client_stream, ATTR_FLAG_STRICT,
471 		  RECV_ATTR_STR(MAIL_ATTR_TABLE, request_map),
472 		  RECV_ATTR_INT(MAIL_ATTR_FLAGS, &request_flags),
473 		  RECV_ATTR_STR(MAIL_ATTR_KEY, request_key),
474 		  RECV_ATTR_STR(MAIL_ATTR_VALUE, request_value),
475 		  ATTR_TYPE_END) != 4) {
476 	reply_status = PROXY_STAT_BAD;
477     } else if (proxy_writer == 0) {
478 	msg_warn("refusing %s update request on non-%s service",
479 		 STR(request_map), MAIL_SERVICE_PROXYWRITE);
480 	reply_status = PROXY_STAT_DENY;
481     } else if ((dict = proxy_map_find(STR(request_map), request_flags,
482 				      &reply_status)) == 0) {
483 	 /* void */ ;
484     } else {
485 	dict->flags = ((dict->flags & ~DICT_FLAG_RQST_MASK)
486 		       | (request_flags & DICT_FLAG_RQST_MASK)
487 		       | DICT_FLAG_SYNC_UPDATE | DICT_FLAG_DUP_REPLACE);
488 	dict_status = dict_put(dict, STR(request_key), STR(request_value));
489 	if (dict_status == 0) {
490 	    reply_status = PROXY_STAT_OK;
491 	} else if (dict->error == 0) {
492 	    reply_status = PROXY_STAT_NOKEY;
493 	} else {
494 	    reply_status = (dict->error == DICT_ERR_RETRY ?
495 			    PROXY_STAT_RETRY : PROXY_STAT_CONFIG);
496 	}
497     }
498 
499     /*
500      * Respond to the client.
501      */
502     attr_print(client_stream, ATTR_FLAG_NONE,
503 	       SEND_ATTR_INT(MAIL_ATTR_STATUS, reply_status),
504 	       ATTR_TYPE_END);
505 }
506 
507 /* proxymap_delete_service - remote delete service */
508 
509 static void proxymap_delete_service(VSTREAM *client_stream)
510 {
511     int     request_flags;
512     DICT   *dict;
513     int     dict_status;
514     int     reply_status;
515 
516     /*
517      * Process the request.
518      *
519      * XXX We don't close maps, so we must turn on synchronous update to ensure
520      * that the on-disk data is in a consistent state between updates.
521      */
522     if (attr_scan(client_stream, ATTR_FLAG_STRICT,
523 		  RECV_ATTR_STR(MAIL_ATTR_TABLE, request_map),
524 		  RECV_ATTR_INT(MAIL_ATTR_FLAGS, &request_flags),
525 		  RECV_ATTR_STR(MAIL_ATTR_KEY, request_key),
526 		  ATTR_TYPE_END) != 3) {
527 	reply_status = PROXY_STAT_BAD;
528     } else if (proxy_writer == 0) {
529 	msg_warn("refusing %s delete request on non-%s service",
530 		 STR(request_map), MAIL_SERVICE_PROXYWRITE);
531 	reply_status = PROXY_STAT_DENY;
532     } else if ((dict = proxy_map_find(STR(request_map), request_flags,
533 				      &reply_status)) == 0) {
534 	 /* void */ ;
535     } else {
536 	dict->flags = ((dict->flags & ~DICT_FLAG_RQST_MASK)
537 		       | (request_flags & DICT_FLAG_RQST_MASK)
538 		       | DICT_FLAG_SYNC_UPDATE);
539 	dict_status = dict_del(dict, STR(request_key));
540 	if (dict_status == 0) {
541 	    reply_status = PROXY_STAT_OK;
542 	} else if (dict->error == 0) {
543 	    reply_status = PROXY_STAT_NOKEY;
544 	} else {
545 	    reply_status = (dict->error == DICT_ERR_RETRY ?
546 			    PROXY_STAT_RETRY : PROXY_STAT_CONFIG);
547 	}
548     }
549 
550     /*
551      * Respond to the client.
552      */
553     attr_print(client_stream, ATTR_FLAG_NONE,
554 	       SEND_ATTR_INT(MAIL_ATTR_STATUS, reply_status),
555 	       ATTR_TYPE_END);
556 }
557 
558 /* proxymap_open_service - open remote lookup table */
559 
560 static void proxymap_open_service(VSTREAM *client_stream)
561 {
562     int     request_flags;
563     DICT   *dict;
564     int     reply_status;
565     int     reply_flags;
566 
567     /*
568      * Process the request.
569      */
570     if (attr_scan(client_stream, ATTR_FLAG_STRICT,
571 		  RECV_ATTR_STR(MAIL_ATTR_TABLE, request_map),
572 		  RECV_ATTR_INT(MAIL_ATTR_FLAGS, &request_flags),
573 		  ATTR_TYPE_END) != 2) {
574 	reply_status = PROXY_STAT_BAD;
575 	reply_flags = 0;
576     } else if ((dict = proxy_map_find(STR(request_map), request_flags,
577 				      &reply_status)) == 0) {
578 	reply_flags = 0;
579     } else {
580 	reply_status = PROXY_STAT_OK;
581 	reply_flags = dict->flags;
582     }
583 
584     /*
585      * Respond to the client.
586      */
587     attr_print(client_stream, ATTR_FLAG_NONE,
588 	       SEND_ATTR_INT(MAIL_ATTR_STATUS, reply_status),
589 	       SEND_ATTR_INT(MAIL_ATTR_FLAGS, reply_flags),
590 	       ATTR_TYPE_END);
591 }
592 
593 /* proxymap_service - perform service for client */
594 
595 static void proxymap_service(VSTREAM *client_stream, char *unused_service,
596 			             char **argv)
597 {
598 
599     /*
600      * Sanity check. This service takes no command-line arguments.
601      */
602     if (argv[0])
603 	msg_fatal("unexpected command-line argument: %s", argv[0]);
604 
605     /*
606      * Deadline enforcement.
607      */
608     if (vstream_fstat(client_stream, VSTREAM_FLAG_DEADLINE) == 0)
609 	vstream_control(client_stream,
610 			CA_VSTREAM_CTL_TIMEOUT(1),
611 			CA_VSTREAM_CTL_END);
612 
613     /*
614      * This routine runs whenever a client connects to the socket dedicated
615      * to the proxymap service. All connection-management stuff is handled by
616      * the common code in multi_server.c.
617      */
618     vstream_control(client_stream,
619 		    CA_VSTREAM_CTL_START_DEADLINE,
620 		    CA_VSTREAM_CTL_END);
621     if (attr_scan(client_stream,
622 		  ATTR_FLAG_MORE | ATTR_FLAG_STRICT,
623 		  RECV_ATTR_STR(MAIL_ATTR_REQ, request),
624 		  ATTR_TYPE_END) == 1) {
625 	if (VSTREQ(request, PROXY_REQ_LOOKUP)) {
626 	    proxymap_lookup_service(client_stream);
627 	} else if (VSTREQ(request, PROXY_REQ_UPDATE)) {
628 	    proxymap_update_service(client_stream);
629 	} else if (VSTREQ(request, PROXY_REQ_DELETE)) {
630 	    proxymap_delete_service(client_stream);
631 	} else if (VSTREQ(request, PROXY_REQ_SEQUENCE)) {
632 	    proxymap_sequence_service(client_stream);
633 	} else if (VSTREQ(request, PROXY_REQ_OPEN)) {
634 	    proxymap_open_service(client_stream);
635 	} else {
636 	    msg_warn("unrecognized request: \"%s\", ignored", STR(request));
637 	    attr_print(client_stream, ATTR_FLAG_NONE,
638 		       SEND_ATTR_INT(MAIL_ATTR_STATUS, PROXY_STAT_BAD),
639 		       ATTR_TYPE_END);
640 	}
641     }
642     vstream_control(client_stream,
643 		    CA_VSTREAM_CTL_START_DEADLINE,
644 		    CA_VSTREAM_CTL_END);
645     vstream_fflush(client_stream);
646 }
647 
648 /* dict_proxy_open - intercept remote map request from inside library */
649 
650 DICT   *dict_proxy_open(const char *map, int open_flags, int dict_flags)
651 {
652     if (msg_verbose)
653 	msg_info("dict_proxy_open(%s, 0%o, 0%o) called from internal routine",
654 		 map, open_flags, dict_flags);
655     while (strncmp(map, PROXY_COLON, PROXY_COLON_LEN) == 0)
656 	map += PROXY_COLON_LEN;
657     return (dict_open(map, open_flags, dict_flags));
658 }
659 
660 /* post_jail_init - initialization after privilege drop */
661 
662 static void post_jail_init(char *service_name, char **unused_argv)
663 {
664     const char *sep = CHARS_COMMA_SP;
665     const char *parens = CHARS_BRACE;
666     char   *saved_filter;
667     char   *bp;
668     char   *type_name;
669 
670     /*
671      * Are we proxy writer?
672      */
673     if (strcmp(service_name, MAIL_SERVICE_PROXYWRITE) == 0)
674 	proxy_writer = 1;
675     else if (strcmp(service_name, MAIL_SERVICE_PROXYMAP) != 0)
676 	msg_fatal("service name must be one of %s or %s",
677 		  MAIL_SERVICE_PROXYMAP, MAIL_SERVICE_PROXYMAP);
678 
679     /*
680      * Pre-allocate buffers.
681      */
682     request = vstring_alloc(10);
683     request_map = vstring_alloc(10);
684     request_key = vstring_alloc(10);
685     request_value = vstring_alloc(10);
686     map_type_name_flags = vstring_alloc(10);
687 
688     /*
689      * Prepare the pre-approved list of proxied tables.
690      */
691     saved_filter = bp = mystrdup(proxy_writer ? var_proxy_write_maps :
692 				 var_proxy_read_maps);
693     proxy_auth_maps = htable_create(13);
694     while ((type_name = mystrtokq(&bp, sep, parens)) != 0) {
695 	if (strncmp(type_name, PROXY_COLON, PROXY_COLON_LEN))
696 	    continue;
697 	do {
698 	    type_name += PROXY_COLON_LEN;
699 	} while (!strncmp(type_name, PROXY_COLON, PROXY_COLON_LEN));
700 	if (strchr(type_name, ':') != 0
701 	    && htable_locate(proxy_auth_maps, type_name) == 0)
702 	    (void) htable_enter(proxy_auth_maps, type_name, (void *) 0);
703     }
704     myfree(saved_filter);
705 
706     /*
707      * Never, ever, get killed by a master signal, as that could corrupt a
708      * persistent database when we're in the middle of an update.
709      */
710     if (proxy_writer != 0)
711 	setsid();
712 }
713 
714 /* pre_accept - see if tables have changed */
715 
716 static void pre_accept(char *unused_name, char **unused_argv)
717 {
718     const char *table;
719 
720     if (proxy_writer == 0 && (table = dict_changed_name()) != 0) {
721 	msg_info("table %s has changed -- restarting", table);
722 	exit(0);
723     }
724 }
725 
726 MAIL_VERSION_STAMP_DECLARE;
727 
728 /* main - pass control to the multi-threaded skeleton */
729 
730 int     main(int argc, char **argv)
731 {
732     static const CONFIG_STR_TABLE str_table[] = {
733 	VAR_ALIAS_MAPS, DEF_ALIAS_MAPS, &var_alias_maps, 0, 0,
734 	VAR_LOCAL_RCPT_MAPS, DEF_LOCAL_RCPT_MAPS, &var_local_rcpt_maps, 0, 0,
735 	VAR_VIRT_ALIAS_MAPS, DEF_VIRT_ALIAS_MAPS, &var_virt_alias_maps, 0, 0,
736 	VAR_VIRT_ALIAS_DOMS, DEF_VIRT_ALIAS_DOMS, &var_virt_alias_doms, 0, 0,
737 	VAR_VIRT_MAILBOX_MAPS, DEF_VIRT_MAILBOX_MAPS, &var_virt_mailbox_maps, 0, 0,
738 	VAR_VIRT_MAILBOX_DOMS, DEF_VIRT_MAILBOX_DOMS, &var_virt_mailbox_doms, 0, 0,
739 	VAR_RELAY_RCPT_MAPS, DEF_RELAY_RCPT_MAPS, &var_relay_rcpt_maps, 0, 0,
740 	VAR_RELAY_DOMAINS, DEF_RELAY_DOMAINS, &var_relay_domains, 0, 0,
741 	VAR_CANONICAL_MAPS, DEF_CANONICAL_MAPS, &var_canonical_maps, 0, 0,
742 	VAR_SEND_CANON_MAPS, DEF_SEND_CANON_MAPS, &var_send_canon_maps, 0, 0,
743 	VAR_RCPT_CANON_MAPS, DEF_RCPT_CANON_MAPS, &var_rcpt_canon_maps, 0, 0,
744 	VAR_RELOCATED_MAPS, DEF_RELOCATED_MAPS, &var_relocated_maps, 0, 0,
745 	VAR_TRANSPORT_MAPS, DEF_TRANSPORT_MAPS, &var_transport_maps, 0, 0,
746 	VAR_VERIFY_MAP, DEF_VERIFY_MAP, &var_verify_map, 0, 0,
747 	VAR_SMTPD_SND_AUTH_MAPS, DEF_SMTPD_SND_AUTH_MAPS, &var_smtpd_snd_auth_maps, 0, 0,
748 	VAR_PSC_CACHE_MAP, DEF_PSC_CACHE_MAP, &var_psc_cache_map, 0, 0,
749 	/* The following two must be last for $mapname to work as expected. */
750 	VAR_PROXY_READ_MAPS, DEF_PROXY_READ_MAPS, &var_proxy_read_maps, 0, 0,
751 	VAR_PROXY_WRITE_MAPS, DEF_PROXY_WRITE_MAPS, &var_proxy_write_maps, 0, 0,
752 	0,
753     };
754 
755     /*
756      * Fingerprint executables and core dumps.
757      */
758     MAIL_VERSION_STAMP_ALLOCATE;
759 
760     multi_server_main(argc, argv, proxymap_service,
761 		      CA_MAIL_SERVER_STR_TABLE(str_table),
762 		      CA_MAIL_SERVER_POST_INIT(post_jail_init),
763 		      CA_MAIL_SERVER_PRE_ACCEPT(pre_accept),
764     /* XXX CA_MAIL_SERVER_SOLITARY if proxywrite */
765 		      0);
766 }
767