1/*++
2/* NAME
3/*	maps 3
4/* SUMMARY
5/*	multi-dictionary search
6/* SYNOPSIS
7/*	#include <maps.h>
8/*
9/*	MAPS	*maps_create(title, map_names, flags)
10/*	const char *title;
11/*	const char *map_names;
12/*	int	flags;
13/*
14/*	const char *maps_find(maps, key, flags)
15/*	MAPS	*maps;
16/*	const char *key;
17/*	int	flags;
18/*
19/*	MAPS	*maps_free(maps)
20/*	MAPS	*maps;
21/* DESCRIPTION
22/*	This module implements multi-dictionary searches. it goes
23/*	through the high-level dictionary interface and does file
24/*	locking. Dictionaries are opened read-only, and in-memory
25/*	dictionary instances are shared.
26/*
27/*	maps_create() takes list of type:name pairs and opens the
28/*	named dictionaries.
29/*	The result is a handle that must be specified along with all
30/*	other maps_xxx() operations.
31/*	See dict_open(3) for a description of flags.
32/*	This includes the flags that specify preferences for search
33/*	string case folding.
34/*
35/*	maps_find() searches the specified list of dictionaries
36/*	in the specified order for the named key. The result is in
37/*	memory that is overwritten upon each call.
38/*	The flags argument is either 0 or specifies a filter:
39/*	for example, DICT_FLAG_FIXED | DICT_FLAG_PATTERN selects
40/*	dictionaries that have fixed keys or pattern keys.
41/*
42/*	maps_free() releases storage claimed by maps_create()
43/*	and conveniently returns a null pointer.
44/*
45/*	Arguments:
46/* .IP title
47/*	String used for diagnostics. Typically one specifies the
48/*	type of information stored in the lookup tables.
49/* .IP map_names
50/*	Null-terminated string with type:name dictionary specifications,
51/*	separated by whitespace or commas.
52/* .IP flags
53/*	With maps_create(), flags that are passed to dict_open().
54/*	With maps_find(), flags that control searching behavior
55/*	as documented above.
56/* .IP maps
57/*	A result from maps_create().
58/* .IP key
59/*	Null-terminated string with a lookup key. Table lookup is case
60/*	sensitive.
61/* DIAGNOSTICS
62/*	Panic: inappropriate use; fatal errors: out of memory, unable
63/*	to open database. Warnings: null string lookup result.
64/*
65/*	maps_find() returns a null pointer when the requested
66/*	information was not found, and logs a warning when the
67/*	lookup failed due to error. The maps->error value indicates
68/*	if the last lookup failed due to error.
69/* BUGS
70/*	The dictionary name space is flat, so dictionary names allocated
71/*	by maps_create() may collide with dictionary names allocated by
72/*	other methods.
73/*
74/*	This functionality could be implemented by allowing the user to
75/*	specify dictionary search paths to dict_lookup() or dict_eval().
76/*	However, that would either require that the dict(3) module adopts
77/*	someone else's list notation syntax, or that the dict(3) module
78/*	imposes syntax restrictions onto other software, neither of which
79/*	is desirable.
80/* LICENSE
81/* .ad
82/* .fi
83/*	The Secure Mailer license must be distributed with this software.
84/* AUTHOR(S)
85/*	Wietse Venema
86/*	IBM T.J. Watson Research
87/*	P.O. Box 704
88/*	Yorktown Heights, NY 10598, USA
89/*--*/
90
91/* System library. */
92
93#include <sys_defs.h>
94#include <string.h>
95
96/* Utility library. */
97
98#include <argv.h>
99#include <mymalloc.h>
100#include <msg.h>
101#include <dict.h>
102#include <stringops.h>
103#include <split_at.h>
104
105/* Global library. */
106
107#include "mail_conf.h"
108#include "maps.h"
109
110/* maps_create - initialize */
111
112MAPS   *maps_create(const char *title, const char *map_names, int dict_flags)
113{
114    const char *myname = "maps_create";
115    char   *temp;
116    char   *bufp;
117    static char sep[] = " \t,\r\n";
118    MAPS   *maps;
119    char   *map_type_name;
120    VSTRING *map_type_name_flags;
121    DICT   *dict;
122
123    /*
124     * Initialize.
125     */
126    maps = (MAPS *) mymalloc(sizeof(*maps));
127    maps->title = mystrdup(title);
128    maps->argv = argv_alloc(2);
129    maps->error = 0;
130
131    /*
132     * For each specified type:name pair, either register a new dictionary,
133     * or increment the reference count of an existing one.
134     */
135    if (*map_names) {
136	bufp = temp = mystrdup(map_names);
137	map_type_name_flags = vstring_alloc(10);
138
139#define OPEN_FLAGS	O_RDONLY
140
141	while ((map_type_name = mystrtok(&bufp, sep)) != 0) {
142	    vstring_sprintf(map_type_name_flags, "%s(%o,%s)",
143			    map_type_name, OPEN_FLAGS,
144			    dict_flags_str(dict_flags));
145	    if ((dict = dict_handle(vstring_str(map_type_name_flags))) == 0)
146		dict = dict_open(map_type_name, OPEN_FLAGS, dict_flags);
147	    if ((dict->flags & dict_flags) != dict_flags)
148		msg_panic("%s: map %s has flags 0%o, want flags 0%o",
149			  myname, map_type_name, dict->flags, dict_flags);
150	    dict_register(vstring_str(map_type_name_flags), dict);
151	    argv_add(maps->argv, vstring_str(map_type_name_flags), ARGV_END);
152	}
153	myfree(temp);
154	vstring_free(map_type_name_flags);
155    }
156    return (maps);
157}
158
159/* maps_find - search a list of dictionaries */
160
161const char *maps_find(MAPS *maps, const char *name, int flags)
162{
163    const char *myname = "maps_find";
164    char  **map_name;
165    const char *expansion;
166    DICT   *dict;
167
168    /*
169     * In case of return without map lookup (empty name or no maps).
170     */
171    maps->error = 0;
172
173    /*
174     * Temp. workaround, for buggy callers that pass zero-length keys when
175     * given partial addresses.
176     */
177    if (*name == 0)
178	return (0);
179
180    for (map_name = maps->argv->argv; *map_name; map_name++) {
181	if ((dict = dict_handle(*map_name)) == 0)
182	    msg_panic("%s: dictionary not found: %s", myname, *map_name);
183	if (flags != 0 && (dict->flags & flags) == 0)
184	    continue;
185	if ((expansion = dict_get(dict, name)) != 0) {
186	    if (*expansion == 0) {
187		msg_warn("%s lookup of %s returns an empty string result",
188			 maps->title, name);
189		msg_warn("%s should return NO RESULT in case of NOT FOUND",
190			 maps->title);
191		maps->error = DICT_ERR_RETRY;
192		return (0);
193	    }
194	    if (msg_verbose)
195		msg_info("%s: %s: %s: %s = %s", myname, maps->title,
196			 *map_name, name, expansion);
197	    return (expansion);
198	} else if ((maps->error = dict->error) != 0) {
199	    msg_warn("%s:%s lookup error for \"%.100s\"",
200		     dict->type, dict->name, name);
201	    break;
202	}
203    }
204    if (msg_verbose)
205	msg_info("%s: %s: %s: %s", myname, maps->title, name, maps->error ?
206		 "search aborted" : "not found");
207    return (0);
208}
209
210/* maps_free - release storage */
211
212MAPS   *maps_free(MAPS *maps)
213{
214    char  **map_name;
215
216    for (map_name = maps->argv->argv; *map_name; map_name++) {
217	if (msg_verbose)
218	    msg_info("maps_free: %s", *map_name);
219	dict_unregister(*map_name);
220    }
221    myfree(maps->title);
222    argv_free(maps->argv);
223    myfree((char *) maps);
224    return (0);
225}
226
227#ifdef TEST
228
229#include <vstring.h>
230#include <vstream.h>
231#include <vstring_vstream.h>
232
233int     main(int argc, char **argv)
234{
235    VSTRING *buf = vstring_alloc(100);
236    MAPS   *maps;
237    const char *result;
238
239    if (argc != 2)
240	msg_fatal("usage: %s maps", argv[0]);
241    msg_verbose = 2;
242    maps = maps_create("whatever", argv[1], DICT_FLAG_LOCK);
243
244    while (vstring_fgets_nonl(buf, VSTREAM_IN)) {
245	maps->error = 99;
246	vstream_printf("\"%s\": ", vstring_str(buf));
247	if ((result = maps_find(maps, vstring_str(buf), 0)) != 0) {
248	    vstream_printf("%s\n", result);
249	} else if (maps->error != 0) {
250	    vstream_printf("lookup error\n");
251	} else {
252	    vstream_printf("not found\n");
253	}
254	vstream_fflush(VSTREAM_OUT);
255    }
256    maps_free(maps);
257    vstring_free(buf);
258    return (0);
259}
260
261#endif
262