xref: /netbsd-src/external/ibm-public/postfix/dist/src/util/dict_nisplus.c (revision a30b880ed60a24c405edba78187a04247f4d9d33)
1 /*	$NetBSD: dict_nisplus.c,v 1.1.1.2 2013/01/02 18:59:12 tron Exp $	*/
2 
3 /*++
4 /* NAME
5 /*	dict_nisplus 3
6 /* SUMMARY
7 /*	dictionary manager interface to NIS+ maps
8 /* SYNOPSIS
9 /*	#include <dict_nisplus.h>
10 /*
11 /*	DICT	*dict_nisplus_open(map, open_flags, dict_flags)
12 /*	const char *map;
13 /*	int	dummy;
14 /*	int	dict_flags;
15 /* DESCRIPTION
16 /*	dict_nisplus_open() makes the specified NIS+ map accessible via
17 /*	the generic dictionary operations described in dict_open(3).
18 /*	The \fIdummy\fR argument is not used.
19 /* SEE ALSO
20 /*	dict(3) generic dictionary manager
21 /* DIAGNOSTICS
22 /*	Fatal errors:
23 /* LICENSE
24 /* .ad
25 /* .fi
26 /*	The Secure Mailer license must be distributed with this software.
27 /* AUTHOR(S)
28 /*	Geoff Gibbs
29 /*	UK-HGMP-RC
30 /*	Hinxton
31 /*	Cambridge
32 /*	CB10 1SB, UK
33 /*
34 /*	based on the code for dict_nis.c et al by :-
35 /*
36 /*	Wietse Venema
37 /*	IBM T.J. Watson Research
38 /*	P.O. Box 704
39 /*	Yorktown Heights, NY 10598, USA
40 /*--*/
41 
42 /* System library. */
43 
44 #include <sys_defs.h>
45 #include <stdio.h>
46 #include <string.h>
47 #include <ctype.h>
48 #include <stdlib.h>
49 #ifdef HAS_NISPLUS
50 #include <rpcsvc/nis.h>			/* for nis_list */
51 #endif
52 
53 /* Utility library. */
54 
55 #include <msg.h>
56 #include <mymalloc.h>
57 #include <vstring.h>
58 #include <stringops.h>
59 #include <dict.h>
60 #include <dict_nisplus.h>
61 
62 #ifdef HAS_NISPLUS
63 
64 /* Application-specific. */
65 
66 typedef struct {
67     DICT    dict;			/* generic members */
68     char   *template;			/* parsed query template */
69     int     column;			/* NIS+ field number (start at 1) */
70 } DICT_NISPLUS;
71 
72  /*
73   * Begin quote from nis+(1):
74   *
75   * The following text represents a  context-free  grammar  that defines  the
76   * set of legal  NIS+ names. The terminals in this grammar are the
77   * characters `.' (dot),  `['  (open  bracket), `]'  (close  bracket),  `,'
78   * (comma),  `=' (equals) and whitespace. Angle brackets (`<' and `>'),
79   * which delineate  non- terminals,  are  not  part of the grammar. The
80   * character `|' (vertical bar) is used to separate alternate productions
81   * and should be read as ``this production OR this production''.
82   *
83   * name                ::=    . | <simple name> | <indexed name>
84   *
85   * simple name         ::=    <string>. | <string>.<simple name>
86   *
87   * indexed name        ::=    <search criterion>,<simple name>
88   *
89   * search criterion    ::=    [ <attribute list> ]
90   *
91   * attribute list      ::=    <attribute> |  <attribute>,<attribute list>
92   *
93   * attribute           ::=    <string> = <string>
94   *
95   * string              ::=    ISO Latin 1 character set except  the character
96   * '/'  (slash).  The initial character may not be a terminal character or
97   * the characters '@' (at), '+' (plus), or (`-') hyphen.
98   *
99   * Terminals that appear in strings must be  quoted   with  `"' (double quote).
100   * The `"' character may be quoted by quoting it with itself `""'.
101   *
102   * End quote fron nis+(1).
103   *
104   * This NIS client always quotes the entire query string (the value part of
105   * [attribute=value],file.domain.) so the issue with initial characters
106   * should not be applicable. One wonders what restrictions are applicable
107   * when a string is quoted, but the manual doesn't specify what can appear
108   * between quotes, and we don't want to get burned.
109   */
110 
111  /*
112   * SLMs.
113   */
114 #define STR(x) vstring_str(x)
115 
116 /* dict_nisplus_lookup - find table entry */
117 
dict_nisplus_lookup(DICT * dict,const char * key)118 static const char *dict_nisplus_lookup(DICT *dict, const char *key)
119 {
120     const char *myname = "dict_nisplus_lookup";
121     DICT_NISPLUS *dict_nisplus = (DICT_NISPLUS *) dict;
122     static VSTRING *quoted_key;
123     static VSTRING *query;
124     static VSTRING *retval;
125     nis_result *reply;
126     int     count;
127     const char *cp;
128     int     last_col;
129     int     ch;
130 
131     dict->error = 0;
132 
133     /*
134      * Initialize.
135      */
136     if (quoted_key == 0) {
137 	query = vstring_alloc(100);
138 	retval = vstring_alloc(100);
139 	quoted_key = vstring_alloc(100);
140     }
141 
142     /*
143      * Optionally fold the key.
144      */
145     if (dict->flags & DICT_FLAG_FOLD_FIX) {
146 	if (dict->fold_buf == 0)
147 	    dict->fold_buf = vstring_alloc(10);
148 	vstring_strcpy(dict->fold_buf, key);
149 	key = lowercase(vstring_str(dict->fold_buf));
150     }
151 
152     /*
153      * Check that the lookup key does not contain characters disallowed by
154      * nis+(1).
155      *
156      * XXX Many client implementations don't seem to care about disallowed
157      * characters.
158      */
159     VSTRING_RESET(quoted_key);
160     VSTRING_ADDCH(quoted_key, '"');
161     for (cp = key; (ch = *(unsigned const char *) cp) != 0; cp++) {
162 	if ((ISASCII(ch) && !ISPRINT(ch)) || (ch > 126 && ch < 160)) {
163 	    msg_warn("map %s:%s: lookup key with non-printing character 0x%x:"
164 		     " ignoring this request",
165 		     dict->type, dict->name, ch);
166 	    return (0);
167 	} else if (ch == '"') {
168 	    VSTRING_ADDCH(quoted_key, '"');
169 	}
170 	VSTRING_ADDCH(quoted_key, ch);
171     }
172     VSTRING_ADDCH(quoted_key, '"');
173     VSTRING_TERMINATE(quoted_key);
174 
175     /*
176      * Plug the key into the query template, which typically looks something
177      * like the following: [alias=%s],mail_aliases.org_dir.my.nisplus.domain.
178      *
179      * XXX The nis+ documentation defines a length limit for simple names like
180      * a.b.c., but defines no length limit for (the components of) indexed
181      * names such as [x=y],a.b.c. Our query length is limited because Postfix
182      * addresses (in envelopes or in headers) have a finite length.
183      */
184     vstring_sprintf(query, dict_nisplus->template, STR(quoted_key));
185     reply = nis_list(STR(query), FOLLOW_LINKS | FOLLOW_PATH, NULL, NULL);
186 
187     /*
188      * When lookup succeeds, the result may be ambiguous, or the requested
189      * column may not exist.
190      */
191     if (reply->status == NIS_SUCCESS) {
192 	if ((count = NIS_RES_NUMOBJ(reply)) != 1) {
193 	    msg_warn("ambiguous match (%d results) for %s in NIS+ map %s:"
194 		     " ignoring this request",
195 		     count, key, dict_nisplus->dict.name);
196 	    nis_freeresult(reply);
197 	    return (0);
198 	} else {
199 	    last_col = NIS_RES_OBJECT(reply)->zo_data
200 		.objdata_u.en_data.en_cols.en_cols_len - 1;
201 	    if (dict_nisplus->column > last_col)
202 		msg_fatal("requested column %d > max column %d in table %s",
203 			  dict_nisplus->column, last_col,
204 			  dict_nisplus->dict.name);
205 	    vstring_strcpy(retval,
206 			   NIS_RES_OBJECT(reply)->zo_data.objdata_u
207 			   .en_data.en_cols.en_cols_val[dict_nisplus->column]
208 			   .ec_value.ec_value_val);
209 	    if (msg_verbose)
210 		msg_info("%s: %s, column %d -> %s", myname, STR(query),
211 			 dict_nisplus->column, STR(retval));
212 	    nis_freeresult(reply);
213 	    return (STR(retval));
214 	}
215     }
216 
217     /*
218      * When the NIS+ lookup fails for reasons other than "key not found",
219      * keep logging warnings, and hope that someone will eventually notice
220      * the problem and fix it.
221      */
222     else {
223 	if (reply->status != NIS_NOTFOUND
224 	    && reply->status != NIS_PARTIAL) {
225 	    msg_warn("lookup %s, NIS+ map %s: %s",
226 		     key, dict_nisplus->dict.name,
227 		     nis_sperrno(reply->status));
228 	    dict->error = DICT_ERR_RETRY;
229 	} else {
230 	    if (msg_verbose)
231 		msg_info("%s: not found: query %s", myname, STR(query));
232 	}
233 	nis_freeresult(reply);
234 	return (0);
235     }
236 }
237 
238 /* dict_nisplus_close - close NISPLUS map */
239 
dict_nisplus_close(DICT * dict)240 static void dict_nisplus_close(DICT *dict)
241 {
242     DICT_NISPLUS *dict_nisplus = (DICT_NISPLUS *) dict;
243 
244     myfree(dict_nisplus->template);
245     if (dict->fold_buf)
246 	vstring_free(dict->fold_buf);
247     dict_free(dict);
248 }
249 
250 /* dict_nisplus_open - open NISPLUS map */
251 
dict_nisplus_open(const char * map,int open_flags,int dict_flags)252 DICT   *dict_nisplus_open(const char *map, int open_flags, int dict_flags)
253 {
254     const char *myname = "dict_nisplus_open";
255     DICT_NISPLUS *dict_nisplus;
256     char   *col_field;
257 
258     /*
259      * Sanity check.
260      */
261     if (open_flags != O_RDONLY)
262 	return (dict_surrogate(DICT_TYPE_NISPLUS, map, open_flags, dict_flags,
263 			       "%s:%s map requires O_RDONLY access mode",
264 			       DICT_TYPE_NISPLUS, map));
265 
266     /*
267      * Initialize. This is a read-only map with fixed strings, not with
268      * regular expressions.
269      */
270     dict_nisplus = (DICT_NISPLUS *)
271 	dict_alloc(DICT_TYPE_NISPLUS, map, sizeof(*dict_nisplus));
272     dict_nisplus->dict.lookup = dict_nisplus_lookup;
273     dict_nisplus->dict.close = dict_nisplus_close;
274     dict_nisplus->dict.flags = dict_flags | DICT_FLAG_FIXED;
275     if (dict_flags & DICT_FLAG_FOLD_FIX)
276 	dict_nisplus->dict.fold_buf = vstring_alloc(10);
277     dict_nisplus->dict.owner.status = DICT_OWNER_TRUSTED;
278 
279     /*
280      * Convert the query template into an indexed name and column number. The
281      * query template looks like:
282      *
283      * [attribute=%s;attribute=value...];simple.name.:column
284      *
285      * One instance of %s gets to be replaced by a version of the lookup key;
286      * other attributes must specify fixed values. The reason for using ';'
287      * is that the comma character is special in main.cf. When no column
288      * number is given at the end of the map name, we use a default column.
289      */
290     dict_nisplus->template = mystrdup(map);
291     translit(dict_nisplus->template, ";", ",");
292     if ((col_field = strstr(dict_nisplus->template, ".:")) != 0) {
293 	col_field[1] = 0;
294 	col_field += 2;
295 	if (!alldig(col_field) || (dict_nisplus->column = atoi(col_field)) < 1)
296 	    msg_fatal("bad column field in NIS+ map name: %s", map);
297     } else {
298 	dict_nisplus->column = 1;
299     }
300     if (msg_verbose)
301 	msg_info("%s: opened NIS+ table %s for column %d",
302 		 myname, dict_nisplus->template, dict_nisplus->column);
303     return (DICT_DEBUG (&dict_nisplus->dict));
304 }
305 
306 #endif
307