xref: /netbsd-src/external/ibm-public/postfix/dist/src/util/dict_open.c (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 /*	$NetBSD: dict_open.c,v 1.1.1.6 2013/09/25 19:06:37 tron Exp $	*/
2 
3 /*++
4 /* NAME
5 /*	dict_open 3
6 /* SUMMARY
7 /*	low-level dictionary interface
8 /* SYNOPSIS
9 /*	#include <dict.h>
10 /*
11 /*	DICT	*dict_open(dict_spec, open_flags, dict_flags)
12 /*	const char *dict_spec;
13 /*	int	open_flags;
14 /*	int	dict_flags;
15 /*
16 /*	DICT	*dict_open3(dict_type, dict_name, open_flags, dict_flags)
17 /*	const char *dict_type;
18 /*	const char *dict_name;
19 /*	int	open_flags;
20 /*	int	dict_flags;
21 /*
22 /*	int	dict_put(dict, key, value)
23 /*	DICT	*dict;
24 /*	const char *key;
25 /*	const char *value;
26 /*
27 /*	const char *dict_get(dict, key)
28 /*	DICT	*dict;
29 /*	const char *key;
30 /*
31 /*	int	dict_del(dict, key)
32 /*	DICT	*dict;
33 /*	const char *key;
34 /*
35 /*	int	dict_seq(dict, func, key, value)
36 /*	DICT	*dict;
37 /*	int	func;
38 /*	const char **key;
39 /*	const char **value;
40 /*
41 /*	void	dict_close(dict)
42 /*	DICT	*dict;
43 /*
44 /*	dict_open_register(type, open)
45 /*	char	*type;
46 /*	DICT	*(*open) (const char *, int, int);
47 /*
48 /*	ARGV	*dict_mapnames()
49 /* DESCRIPTION
50 /*	This module implements a low-level interface to multiple
51 /*	physical dictionary types.
52 /*
53 /*	dict_open() takes a type:name pair that specifies a dictionary type
54 /*	and dictionary name, opens the dictionary, and returns a dictionary
55 /*	handle.  The \fIopen_flags\fR arguments are as in open(2). The
56 /*	\fIdict_flags\fR are the bit-wise OR of zero or more of the following:
57 /* .IP DICT_FLAG_DUP_WARN
58 /*	Warn about duplicate keys, if the underlying database does not
59 /*	support duplicate keys. The default is to terminate with a fatal
60 /*	error.
61 /* .IP DICT_FLAG_DUP_IGNORE
62 /*	Ignore duplicate keys if the underlying database does not
63 /*	support duplicate keys. The default is to terminate with a fatal
64 /*	error.
65 /* .IP DICT_FLAG_DUP_REPLACE
66 /*	Replace duplicate keys if the underlying database supports such
67 /*	an operation. The default is to terminate with a fatal error.
68 /* .IP DICT_FLAG_TRY0NULL
69 /*	With maps where this is appropriate, append no null byte to
70 /*	keys and values.
71 /*	When neither DICT_FLAG_TRY0NULL nor DICT_FLAG_TRY1NULL are
72 /*	specified, the software guesses what format to use for reading;
73 /*	and in the absence of definite information, a system-dependent
74 /*	default is chosen for writing.
75 /* .IP DICT_FLAG_TRY1NULL
76 /*	With maps where this is appropriate, append one null byte to
77 /*	keys and values.
78 /*	When neither DICT_FLAG_TRY0NULL nor DICT_FLAG_TRY1NULL are
79 /*	specified, the software guesses what format to use for reading;
80 /*	and in the absence of definite information, a system-dependent
81 /*	default is chosen for writing.
82 /* .IP DICT_FLAG_LOCK
83 /*	With maps where this is appropriate, acquire an exclusive lock
84 /*	before writing, and acquire a shared lock before reading.
85 /* .IP DICT_FLAG_OPEN_LOCK
86 /*	With databases that are not multi-writer safe, request that
87 /*	dict_open() acquires an exclusive lock, or that it terminates
88 /*	with a fatal run-time error.
89 /* .IP DICT_FLAG_FOLD_FIX
90 /*	With databases whose lookup fields are fixed-case strings,
91 /*	fold the search string to lower case before accessing the
92 /*	database.  This includes hash:, cdb:, dbm:. nis:, ldap:,
93 /*	*sql.
94 /* .IP DICT_FLAG_FOLD_MUL
95 /*	With databases where one lookup field can match both upper
96 /*	and lower case, fold the search key to lower case before
97 /*	accessing the database. This includes regexp: and pcre:
98 /* .IP DICT_FLAG_FOLD_ANY
99 /*	Short-hand for (DICT_FLAG_FOLD_FIX | DICT_FLAG_FOLD_MUL).
100 /* .IP DICT_FLAG_SYNC_UPDATE
101 /*	With file-based maps, flush I/O buffers to file after each update.
102 /*	Thus feature is not supported with some file-based dictionaries.
103 /* .IP DICT_FLAG_NO_REGSUB
104 /*	Disallow regular expression substitution from the lookup string
105 /*	into the lookup result, to block data injection attacks.
106 /* .IP DICT_FLAG_NO_PROXY
107 /*	Disallow access through the unprivileged \fBproxymap\fR
108 /*	service, to block privilege escalation attacks.
109 /* .IP DICT_FLAG_NO_UNAUTH
110 /*	Disallow lookup mechanisms that lack any form of authentication,
111 /*	to block privilege escalation attacks (example: tcp_table;
112 /*	even NIS can be secured to some extent by requiring that
113 /*	the server binds to a privileged port).
114 /* .IP DICT_FLAG_PARANOID
115 /*	A combination of all the paranoia flags: DICT_FLAG_NO_REGSUB,
116 /*	DICT_FLAG_NO_PROXY and DICT_FLAG_NO_UNAUTH.
117 /* .IP DICT_FLAG_DEBUG
118 /*	Enable additional logging.
119 /* .PP
120 /*	Specify DICT_FLAG_NONE for no special processing.
121 /*
122 /*	The dictionary types are as follows:
123 /* .IP environ
124 /*	The process environment array. The \fIdict_name\fR argument is ignored.
125 /* .IP dbm
126 /*	DBM file.
127 /* .IP hash
128 /*	Berkeley DB file in hash format.
129 /* .IP btree
130 /*	Berkeley DB file in btree format.
131 /* .IP nis
132 /*	NIS map. Only read access is supported.
133 /* .IP nisplus
134 /*	NIS+ map. Only read access is supported.
135 /* .IP netinfo
136 /*	NetInfo table. Only read access is supported.
137 /* .IP ldap
138 /*	LDAP ("light-weight" directory access protocol) database access.
139 /* .IP pcre
140 /*	PERL-compatible regular expressions.
141 /* .IP regexp
142 /*	POSIX-compatible regular expressions.
143 /* .IP texthash
144 /*	Flat text in postmap(1) input format.
145 /* .PP
146 /*	dict_open3() takes separate arguments for dictionary type and
147 /*	name, but otherwise performs the same functions as dict_open().
148 /*
149 /*	dict_get() retrieves the value stored in the named dictionary
150 /*	under the given key. A null pointer means the value was not found.
151 /*	As with dict_lookup(), the result is owned by the lookup table
152 /*	implementation. Make a copy if the result is to be modified,
153 /*	or if the result is to survive multiple table lookups.
154 /*
155 /*	dict_put() stores the specified key and value into the named
156 /*	dictionary. A zero (DICT_STAT_SUCCESS) result means the
157 /*	update was made.
158 /*
159 /*	dict_del() removes a dictionary entry, and returns
160 /*	DICT_STAT_SUCCESS in case of success.
161 /*
162 /*	dict_seq() iterates over all members in the named dictionary.
163 /*	func is define DICT_SEQ_FUN_FIRST (select first member) or
164 /*	DICT_SEQ_FUN_NEXT (select next member). A zero (DICT_STAT_SUCCESS)
165 /*	result means that an entry was found.
166 /*
167 /*	dict_close() closes the specified dictionary and cleans up the
168 /*	associated data structures.
169 /*
170 /*	dict_open_register() adds support for a new dictionary type.
171 /*
172 /*	dict_mapnames() returns a sorted list with the names of all available
173 /*	dictionary types.
174 /* DIAGNOSTICS
175 /*	Fatal error: open error, unsupported dictionary type, attempt to
176 /*	update non-writable dictionary.
177 /*
178 /*	The lookup routine returns non-null when the request is
179 /*	satisfied. The update, delete and sequence routines return
180 /*	zero (DICT_STAT_SUCCESS) when the request is satisfied.
181 /*	The dict->errno value is non-zero only when the last operation
182 /*	was not satisfied due to a dictionary access error. This
183 /*	can have the following values:
184 /* .IP DICT_ERR_NONE(zero)
185 /*	There was no dictionary access error. For example, the
186 /*	request was satisfied, the requested information did not
187 /*	exist in the dictionary, or the information already existed
188 /*	when it should not exist (collision).
189 /* .IP DICT_ERR_RETRY(<0)
190 /*	The dictionary was temporarily unavailable. This can happen
191 /*	with network-based services.
192 /* .IP DICT_ERR_CONFIG(<0)
193 /*	The dictionary was unavailable due to a configuration error.
194 /* .PP
195 /*	Generally, a program is expected to test the function result
196 /*	value for "success" first. If the operation was not successful,
197 /*	a program is expected to test for a non-zero dict->error
198 /*	status to distinguish between a data notfound/collision
199 /*	condition or a dictionary access error.
200 /* LICENSE
201 /* .ad
202 /* .fi
203 /*	The Secure Mailer license must be distributed with this software.
204 /* AUTHOR(S)
205 /*	Wietse Venema
206 /*	IBM T.J. Watson Research
207 /*	P.O. Box 704
208 /*	Yorktown Heights, NY 10598, USA
209 /*--*/
210 
211 /* System library. */
212 
213 #include <sys_defs.h>
214 #include <string.h>
215 #include <stdlib.h>
216 
217 #ifdef STRCASECMP_IN_STRINGS_H
218 #include <strings.h>
219 #endif
220 
221 /* Utility library. */
222 
223 #include <argv.h>
224 #include <mymalloc.h>
225 #include <msg.h>
226 #include <dict.h>
227 #include <dict_cdb.h>
228 #include <dict_env.h>
229 #include <dict_unix.h>
230 #include <dict_tcp.h>
231 #include <dict_sdbm.h>
232 #include <dict_dbm.h>
233 #include <dict_db.h>
234 #include <dict_nis.h>
235 #include <dict_nisplus.h>
236 #include <dict_ni.h>
237 #include <dict_pcre.h>
238 #include <dict_regexp.h>
239 #include <dict_static.h>
240 #include <dict_cidr.h>
241 #include <dict_ht.h>
242 #include <dict_thash.h>
243 #include <dict_sockmap.h>
244 #include <dict_fail.h>
245 #include <stringops.h>
246 #include <split_at.h>
247 #include <htable.h>
248 #include <myflock.h>
249 
250  /*
251   * lookup table for available map types.
252   */
253 typedef struct {
254     char   *type;
255     struct DICT *(*open) (const char *, int, int);
256 } DICT_OPEN_INFO;
257 
258 static const DICT_OPEN_INFO dict_open_info[] = {
259 #ifdef HAS_CDB
260     DICT_TYPE_CDB, dict_cdb_open,
261 #endif
262     DICT_TYPE_ENVIRON, dict_env_open,
263     DICT_TYPE_HT, dict_ht_open,
264     DICT_TYPE_UNIX, dict_unix_open,
265     DICT_TYPE_TCP, dict_tcp_open,
266 #ifdef HAS_SDBM
267     DICT_TYPE_SDBM, dict_sdbm_open,
268 #endif
269 #ifdef HAS_DBM
270     DICT_TYPE_DBM, dict_dbm_open,
271 #endif
272 #ifdef HAS_DB
273     DICT_TYPE_HASH, dict_hash_open,
274     DICT_TYPE_BTREE, dict_btree_open,
275 #endif
276 #ifdef HAS_NIS
277     DICT_TYPE_NIS, dict_nis_open,
278 #endif
279 #ifdef HAS_NISPLUS
280     DICT_TYPE_NISPLUS, dict_nisplus_open,
281 #endif
282 #ifdef HAS_NETINFO
283     DICT_TYPE_NETINFO, dict_ni_open,
284 #endif
285 #ifdef HAS_PCRE
286     DICT_TYPE_PCRE, dict_pcre_open,
287 #endif
288 #ifdef HAS_POSIX_REGEXP
289     DICT_TYPE_REGEXP, dict_regexp_open,
290 #endif
291     DICT_TYPE_STATIC, dict_static_open,
292     DICT_TYPE_CIDR, dict_cidr_open,
293     DICT_TYPE_THASH, dict_thash_open,
294     DICT_TYPE_SOCKMAP, dict_sockmap_open,
295     DICT_TYPE_FAIL, dict_fail_open,
296     0,
297 };
298 
299 static HTABLE *dict_open_hash;
300 
301 /* dict_open_init - one-off initialization */
302 
303 static void dict_open_init(void)
304 {
305     const char *myname = "dict_open_init";
306     const DICT_OPEN_INFO *dp;
307 
308     if (dict_open_hash != 0)
309 	msg_panic("%s: multiple initialization", myname);
310     dict_open_hash = htable_create(10);
311 
312     for (dp = dict_open_info; dp->type; dp++)
313 	htable_enter(dict_open_hash, dp->type, (char *) dp);
314 }
315 
316 /* dict_open - open dictionary */
317 
318 DICT   *dict_open(const char *dict_spec, int open_flags, int dict_flags)
319 {
320     char   *saved_dict_spec = mystrdup(dict_spec);
321     char   *dict_name;
322     DICT   *dict;
323 
324     if ((dict_name = split_at(saved_dict_spec, ':')) == 0)
325 	msg_fatal("open dictionary: expecting \"type:name\" form instead of \"%s\"",
326 		  dict_spec);
327 
328     dict = dict_open3(saved_dict_spec, dict_name, open_flags, dict_flags);
329     myfree(saved_dict_spec);
330     return (dict);
331 }
332 
333 
334 /* dict_open3 - open dictionary */
335 
336 DICT   *dict_open3(const char *dict_type, const char *dict_name,
337 		           int open_flags, int dict_flags)
338 {
339     const char *myname = "dict_open";
340     DICT_OPEN_INFO *dp;
341     DICT   *dict;
342 
343     if (*dict_type == 0 || *dict_name == 0)
344 	msg_fatal("open dictionary: expecting \"type:name\" form instead of \"%s:%s\"",
345 		  dict_type, dict_name);
346     if (dict_open_hash == 0)
347 	dict_open_init();
348     if ((dp = (DICT_OPEN_INFO *) htable_find(dict_open_hash, dict_type)) == 0)
349 	return (dict_surrogate(dict_type, dict_name, open_flags, dict_flags,
350 			     "unsupported dictionary type: %s", dict_type));
351     if ((dict = dp->open(dict_name, open_flags, dict_flags)) == 0)
352 	return (dict_surrogate(dict_type, dict_name, open_flags, dict_flags,
353 			    "cannot open %s:%s: %m", dict_type, dict_name));
354     if (msg_verbose)
355 	msg_info("%s: %s:%s", myname, dict_type, dict_name);
356     /* XXX the choice between wait-for-lock or no-wait is hard-coded. */
357     if (dict_flags & DICT_FLAG_OPEN_LOCK) {
358 	if (dict_flags & DICT_FLAG_LOCK)
359 	    msg_panic("%s: attempt to open %s:%s with both \"open\" lock and \"access\" lock",
360 		      myname, dict_type, dict_name);
361 	if (dict->lock(dict, MYFLOCK_OP_EXCLUSIVE | MYFLOCK_OP_NOWAIT) < 0)
362 	    msg_fatal("%s:%s: unable to get exclusive lock: %m",
363 		      dict_type, dict_name);
364     }
365     return (dict);
366 }
367 
368 /* dict_open_register - register dictionary type */
369 
370 void    dict_open_register(const char *type,
371 			           DICT *(*open) (const char *, int, int))
372 {
373     const char *myname = "dict_open_register";
374     DICT_OPEN_INFO *dp;
375 
376     if (dict_open_hash == 0)
377 	dict_open_init();
378     if (htable_find(dict_open_hash, type))
379 	msg_panic("%s: dictionary type exists: %s", myname, type);
380     dp = (DICT_OPEN_INFO *) mymalloc(sizeof(*dp));
381     dp->type = mystrdup(type);
382     dp->open = open;
383     htable_enter(dict_open_hash, dp->type, (char *) dp);
384 }
385 
386 /* dict_sort_alpha_cpp - qsort() callback */
387 
388 static int dict_sort_alpha_cpp(const void *a, const void *b)
389 {
390     return (strcmp(((char **) a)[0], ((char **) b)[0]));
391 }
392 
393 /* dict_mapnames - return an ARGV of available map_names */
394 
395 ARGV   *dict_mapnames()
396 {
397     HTABLE_INFO **ht_info;
398     HTABLE_INFO **ht;
399     DICT_OPEN_INFO *dp;
400     ARGV   *mapnames;
401 
402     if (dict_open_hash == 0)
403 	dict_open_init();
404     mapnames = argv_alloc(dict_open_hash->used + 1);
405     for (ht_info = ht = htable_list(dict_open_hash); *ht; ht++) {
406 	dp = (DICT_OPEN_INFO *) ht[0]->value;
407 	argv_add(mapnames, dp->type, ARGV_END);
408     }
409     qsort((void *) mapnames->argv, mapnames->argc, sizeof(mapnames->argv[0]),
410 	  dict_sort_alpha_cpp);
411     myfree((char *) ht_info);
412     argv_terminate(mapnames);
413     return mapnames;
414 }
415 
416 #ifdef TEST
417 
418  /*
419   * Proof-of-concept test program.
420   */
421 int     main(int argc, char **argv)
422 {
423     dict_test(argc, argv);
424     return (0);
425 }
426 
427 #endif
428