1/*
2 * Copyright (c) 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 * All rights reserved.
5 *
6 * This code is derived from software donated to Berkeley by
7 * Jan-Simon Pendry.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)conf.c	8.2 (Berkeley) 3/27/94
34 */
35
36#include <sys/cdefs.h>
37__FBSDID("$FreeBSD$");
38
39#include <errno.h>
40#include <limits.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <string.h>
44#include <unistd.h>
45#include <regex.h>
46#include <sys/types.h>
47#include <sys/param.h>
48#include <sys/syslog.h>
49
50#include "portald.h"
51
52#define	ALLOC(ty)	(xmalloc(sizeof(ty)))
53
54typedef struct path path;
55struct path {
56	qelem p_q;		/* 2-way linked list */
57	int p_lno;		/* Line number of this record */
58	char *p_args;		/* copy of arg string (malloc) */
59	char *p_key;		/* Pathname to match (also p_argv[0]) */
60	regex_t p_rx;		/* RE to match against pathname () */
61	int p_rxvalid;		/* non-zero if valid regular expression */
62	int p_argc;		/* number of elements in arg string */
63	char **p_argv;		/* argv[] pointers into arg string (malloc) */
64};
65
66static char *conf_file;		/* XXX for regerror */
67static path *curp;		/* XXX for regerror */
68
69/*
70 * Add an element to a 2-way list,
71 * just after (pred)
72 */
73static void ins_que(qelem *elem, qelem *pred)
74{
75	qelem *p = pred->q_forw;
76	elem->q_back = pred;
77	elem->q_forw = p;
78	pred->q_forw = elem;
79	p->q_back = elem;
80}
81
82/*
83 * Remove an element from a 2-way list
84 */
85static void rem_que(qelem *elem)
86{
87	qelem *p = elem->q_forw;
88	qelem *p2 = elem->q_back;
89	p2->q_forw = p;
90	p->q_back = p2;
91}
92
93/*
94 * Error checking malloc
95 */
96static void *xmalloc(unsigned siz)
97{
98	void *p = malloc(siz);
99	if (p)
100		return (p);
101	syslog(LOG_ALERT, "malloc: failed to get %d bytes", siz);
102	exit(1);
103}
104
105/*
106 * Insert the path in the list.
107 * If there is already an element with the same key then
108 * the *second* one is ignored (return 0).  If the key is
109 * not found then the path is added to the end of the list
110 * and 1 is returned.
111 */
112static int pinsert(path *p0, qelem *q0)
113{
114	qelem *q;
115
116	if (p0->p_argc == 0)
117		return (0);
118
119	for (q = q0->q_forw; q != q0; q = q->q_forw) {
120		path *p = (path *) q;
121		if (strcmp(p->p_key, p0->p_key) == 0)
122			return (0);
123	}
124	ins_que(&p0->p_q, q0->q_back);
125	return (1);
126
127}
128
129static path *palloc(char *cline, int lno)
130{
131	int c;
132	char *s;
133	char *key;
134	path *p;
135	char **ap;
136
137	/*
138	 * Implement comment chars
139	 */
140	s = strchr(cline, '#');
141	if (s)
142		*s = 0;
143
144	/*
145	 * Do a pass through the string to count the number
146	 * of arguments
147	 */
148	c = 0;
149	key = strdup(cline);
150	for (s = key; s != NULL; ) {
151		char *val;
152		while ((val = strsep(&s, " \t\n")) != NULL && *val == '\0')
153			;
154		if (val)
155			c++;
156	}
157	c++;
158	free(key);
159
160	if (c <= 1)
161		return (0);
162
163	/*
164	 * Now do another pass and generate a new path structure
165	 */
166	p = ALLOC(path);
167	p->p_argc = 0;
168	p->p_argv = xmalloc(c * sizeof(char *));
169	p->p_args = strdup(cline);
170	ap = p->p_argv;
171	for (s = p->p_args; s != NULL; ) {
172		char *val;
173		while ((val = strsep(&s, " \t\n")) != NULL && *val == '\0')
174			;
175		if (val) {
176			*ap++ = val;
177			p->p_argc++;
178		}
179	}
180	*ap = 0;
181
182#ifdef DEBUG
183	for (c = 0; c < p->p_argc; c++)
184		printf("%sv[%d] = %s\n", c?"\t":"", c, p->p_argv[c]);
185#endif
186
187	p->p_key = p->p_argv[0];
188	if (strpbrk(p->p_key, RE_CHARS)) {
189		int val;
190
191		curp = p;			/* XXX */
192		val = regcomp(&p->p_rx, p->p_key, REG_EXTENDED | REG_NOSUB);
193		if (val) {
194			char errbuf[_POSIX2_LINE_MAX];
195			regerror(val, &p->p_rx, errbuf, sizeof errbuf);
196			syslog(LOG_ERR, "%s:%d: regcomp %s: %s",
197			       conf_file, curp->p_lno, curp->p_key, errbuf);
198			regfree(&p->p_rx);
199			p->p_rxvalid = 0;
200		} else {
201			p->p_rxvalid = 1;
202		}
203		curp = 0;			/* XXX */
204	} else {
205		p->p_rxvalid = 0;
206	}
207	p->p_lno = lno;
208
209	return (p);
210}
211
212/*
213 * Free a path structure
214 */
215static void pfree(path *p)
216{
217	free(p->p_args);
218	if (p->p_rxvalid) {
219		regfree(&p->p_rx);
220	}
221	free((char *) p->p_argv);
222	free((char *) p);
223}
224
225/*
226 * Discard all currently held path structures on q0.
227 * and add all the ones on xq.
228 */
229static void preplace(qelem *q0, qelem *xq)
230{
231	/*
232	 * While the list is not empty,
233	 * take the first element off the list
234	 * and free it.
235	 */
236	while (q0->q_forw != q0) {
237		qelem *q = q0->q_forw;
238		rem_que(q);
239		pfree((path *) q);
240	}
241	while (xq->q_forw != xq) {
242		qelem *q = xq->q_forw;
243		rem_que(q);
244		ins_que(q, q0);
245	}
246}
247
248/*
249 * Read the lines from the configuration file and
250 * add them to the list of paths.
251 */
252static void readfp(qelem *q0, FILE *fp)
253{
254	char cline[LINE_MAX];
255	int nread = 0;
256	qelem q;
257
258	/*
259	 * Make a new empty list.
260	 */
261	q.q_forw = q.q_back = &q;
262
263	/*
264	 * Read the lines from the configuration file.
265	 */
266	while (fgets(cline, sizeof(cline), fp)) {
267		path *p = palloc(cline, nread+1);
268		if (p && !pinsert(p, &q))
269			pfree(p);
270		nread++;
271	}
272
273	/*
274	 * If some records were read, then throw
275	 * away the old list and replace with the
276	 * new one.
277	 */
278	if (nread)
279		preplace(q0, &q);
280}
281
282/*
283 * Read the configuration file (conf) and replace
284 * the existing path list with the new version.
285 * If the file is not readable, then no changes take place
286 */
287void conf_read(qelem *q, char *conf)
288{
289	FILE *fp = fopen(conf, "r");
290	if (fp) {
291		conf_file = conf;		/* XXX */
292		readfp(q, fp);
293		conf_file = 0;		/* XXX */
294		(void) fclose(fp);
295	} else {
296		syslog(LOG_ERR, "open config file \"%s\": %s", conf, strerror(errno));
297	}
298}
299
300
301char **conf_match(qelem *q0, char *key)
302{
303	qelem *q;
304
305	for (q = q0->q_forw; q != q0; q = q->q_forw) {
306		path *p = (path *) q;
307		if (p->p_rxvalid) {
308			if (!regexec(&p->p_rx, key, 0, 0, 0)) {
309				return p->p_argv + 1;
310			}
311		} else {
312			if (strncmp(p->p_key, key, strlen(p->p_key)) == 0)
313				return (p->p_argv+1);
314		}
315	}
316
317	return (0);
318}
319