1 /* $NetBSD: conf.c,v 1.14 2019/05/23 04:34:25 kre Exp $ */
2
3 /*
4 * Copyright (c) 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software donated to Berkeley by
8 * Jan-Simon Pendry.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * from: Id: conf.c,v 1.2 1992/05/27 07:09:27 jsp Exp
35 * @(#)conf.c 8.2 (Berkeley) 3/27/94
36 */
37
38 #include <sys/cdefs.h>
39 #ifndef lint
40 __RCSID("$NetBSD: conf.c,v 1.14 2019/05/23 04:34:25 kre Exp $");
41 #endif /* not lint */
42
43 #include <sys/types.h>
44 #include <sys/param.h>
45 #include <sys/syslog.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <unistd.h>
49 #include <string.h>
50 #include <errno.h>
51 #include <limits.h>
52 #include <regex.h>
53
54 #include "portald.h"
55
56 #define ALLOC(ty) (xmalloc(sizeof(ty)))
57
58 typedef struct path path;
59 struct path {
60 qelem p_q; /* 2-way linked list */
61 int p_lno; /* Line number of this record */
62 char *p_args; /* copy of arg string (malloc) */
63 char *p_key; /* Pathname to match (also p_argv[0]) */
64 regex_t p_re; /* RE to match against pathname (malloc) */
65 int p_use_re; /* true if entry is RE */
66 int p_argc; /* number of elements in arg string */
67 char **p_argv; /* argv[] pointers into arg string (malloc) */
68 };
69
70 static void ins_que(qelem *, qelem *);
71 static path *palloc(char *, int, const char *);
72 static void pfree(path *);
73 static int pinsert(path *, qelem *);
74 static void preplace(qelem *, qelem *);
75 static void readfp(qelem *, FILE *, const char *);
76 static void rem_que(qelem *);
77 static void *xmalloc(size_t);
78
79 /*
80 * Add an element to a 2-way list,
81 * just after (pred)
82 */
83 static void
ins_que(qelem * elem,qelem * pred)84 ins_que(qelem *elem, qelem *pred)
85 {
86 qelem *p = pred->q_forw;
87 elem->q_back = pred;
88 elem->q_forw = p;
89 pred->q_forw = elem;
90 p->q_back = elem;
91 }
92
93 /*
94 * Remove an element from a 2-way list
95 */
96 static void
rem_que(qelem * elem)97 rem_que(qelem *elem)
98 {
99 qelem *p = elem->q_forw;
100 qelem *p2 = elem->q_back;
101 p2->q_forw = p;
102 p->q_back = p2;
103 }
104
105 /*
106 * Error checking malloc
107 */
108 static void *
xmalloc(size_t siz)109 xmalloc(size_t siz)
110 {
111 void *p = malloc(siz);
112
113 if (p)
114 return p;
115
116 syslog(LOG_ERR, "malloc: failed to get %lu bytes", (u_long)siz);
117 exit(1);
118 }
119
120 /*
121 * Insert the path in the list.
122 * If there is already an element with the same key then
123 * the *second* one is ignored (return 0). If the key is
124 * not found then the path is added to the end of the list
125 * and 1 is returned.
126 */
127 static int
pinsert(path * p0,qelem * q0)128 pinsert(path *p0, qelem *q0)
129 {
130 qelem *q;
131
132 if (p0->p_argc == 0)
133 return 0;
134
135 for (q = q0->q_forw; q != q0; q = q->q_forw) {
136 path *p = (path *)q;
137
138 if (strcmp(p->p_key, p0->p_key) == 0)
139 return 0;
140 }
141 ins_que(&p0->p_q, q0->q_back);
142 return 1;
143
144 }
145
146 static path *
palloc(char * cline,int lno,const char * conf_file)147 palloc(char *cline, int lno, const char *conf_file)
148 {
149 int c, errcode;
150 char *s;
151 char *key;
152 path *p;
153 char **ap;
154
155 /*
156 * Do a pass through the string to count the number
157 * of arguments. Stop if we encounter a comment.
158 */
159 c = 0;
160 key = strdup(cline);
161 for (s = key; s != NULL; ) {
162 char *val;
163
164 if (*s == '#') { /* '#" at beginning of word */
165 cline[s-key] = '\0'; /* delete comment -> EOL */
166 break;
167 }
168
169 while ((val = strsep(&s, " \t\n")) != NULL && *val == '\0')
170 ;
171 if (val)
172 c++;
173 }
174 c++;
175 free(key);
176
177 if (c <= 1)
178 return 0;
179
180 /*
181 * Now do another pass and generate a new path structure
182 */
183 p = ALLOC(path);
184 p->p_argc = 0;
185 p->p_argv = xmalloc(c * sizeof(char *));
186 p->p_args = strdup(cline);
187 ap = p->p_argv;
188 for (s = p->p_args; s != NULL; ) {
189 char *val;
190
191 while ((val = strsep(&s, " \t\n")) != NULL && *val == '\0')
192 ;
193 if (val) {
194 *ap++ = val;
195 p->p_argc++;
196 }
197 }
198 *ap = 0;
199
200 #ifdef DEBUG
201 for (c = 0; c < p->p_argc; c++)
202 printf("%sv[%d] = %s\n", c?"\t":"", c, p->p_argv[c]);
203 #endif
204
205 p->p_key = p->p_argv[0];
206 p->p_use_re = 0;
207 if (strpbrk(p->p_key, RE_CHARS)) {
208 errcode = regcomp(&p->p_re, p->p_key, REG_EXTENDED|REG_NOSUB);
209 if (errcode == 0)
210 p->p_use_re = 1;
211 else {
212 char buf[200];
213 regerror(errcode, &p->p_re, buf, sizeof(buf));
214
215 syslog(LOG_WARNING, "%s, line %d: regcomp \"%s\": %s",
216 conf_file, p->p_lno, p->p_key, buf);
217 }
218 }
219 p->p_lno = lno;
220
221 return p;
222 }
223
224 /*
225 * Free a path structure
226 */
227 static void
pfree(path * p)228 pfree(path *p)
229 {
230 free(p->p_args);
231 free((char *)p->p_argv);
232 if (p->p_use_re)
233 regfree(&p->p_re);
234 free((char *)p);
235 }
236
237 /*
238 * Discard all currently held path structures on q0.
239 * and add all the ones on xq.
240 */
241 static void
preplace(qelem * q0,qelem * xq)242 preplace(qelem *q0, qelem *xq)
243 {
244 /*
245 * While the list is not empty,
246 * take the first element off the list
247 * and free it.
248 */
249 while (q0->q_forw != q0) {
250 qelem *q = q0->q_forw;
251 rem_que(q);
252 pfree((path *)q);
253 }
254 while (xq->q_forw != xq) {
255 qelem *q = xq->q_forw;
256 rem_que(q);
257 ins_que(q, q0);
258 }
259 }
260
261 /*
262 * Read the lines from the configuration file and
263 * add them to the list of paths.
264 */
265 static void
readfp(qelem * q0,FILE * fp,const char * conf_file)266 readfp(qelem *q0, FILE *fp, const char *conf_file)
267 {
268 char cline[LINE_MAX];
269 int nread = 0;
270 qelem q;
271
272 /*
273 * Make a new empty list.
274 */
275 q.q_forw = q.q_back = &q;
276
277 /*
278 * Read the lines from the configuration file.
279 */
280 while (fgets(cline, sizeof(cline), fp)) {
281 path *p = palloc(cline, nread+1, conf_file);
282
283 if (p && !pinsert(p, &q))
284 pfree(p);
285 nread++;
286 }
287
288 /*
289 * If some records were read, then throw
290 * away the old list and replace with the
291 * new one.
292 */
293 if (nread)
294 preplace(q0, &q);
295 }
296
297 /*
298 * Read the configuration file (conf) and replace
299 * the existing path list with the new version.
300 * If the file is not readable, then no changes take place
301 */
302 int
conf_read(qelem * q,const char * conf)303 conf_read(qelem *q, const char *conf)
304 {
305 FILE *fp = fopen(conf, "r");
306
307 if (fp) {
308 readfp(q, fp, conf);
309 (void)fclose(fp);
310 return 0;
311 } else {
312 int sverrno = errno;
313
314 syslog(LOG_WARNING, "open config file \"%s\": %m", conf);
315 errno = sverrno;
316 return -1;
317 }
318 }
319
320
321 char **
conf_match(qelem * q0,char * key)322 conf_match(qelem *q0, char *key)
323 {
324 qelem *q;
325
326 for (q = q0->q_forw; q != q0; q = q->q_forw) {
327 path *p = (path *)q;
328
329 if (p->p_use_re) {
330 if (regexec(&p->p_re, key, 0, NULL, 0) == 0)
331 return p->p_argv + 1;
332 } else {
333 if (strncmp(p->p_key, key, strlen(p->p_key)) == 0)
334 return p->p_argv + 1;
335 }
336 }
337
338 return 0;
339 }
340