1/*-
2 * SPDX-License-Identifier: BSD-4-Clause
3 *
4 * Copyright (c) 1993 Paul Kranenburg
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *      This product includes software developed by Paul Kranenburg.
18 * 4. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 *
32 * $FreeBSD$
33 */
34
35#include <sys/param.h>
36#include <sys/types.h>
37#include <sys/stat.h>
38#include <sys/file.h>
39#include <sys/time.h>
40#include <a.out.h>
41#include <ctype.h>
42#include <dirent.h>
43#include <err.h>
44#include <fcntl.h>
45#include <stdio.h>
46#include <stdlib.h>
47#include <string.h>
48
49#include <sys/link_aout.h>
50#include "shlib.h"
51#include "support.h"
52
53/*
54 * Standard directories to search for files specified by -l.
55 */
56#ifndef STANDARD_SEARCH_DIRS
57#define STANDARD_SEARCH_DIRS    "/usr/lib/aout"
58#endif
59
60/*
61 * Actual vector of library search directories,
62 * including `-L'ed and LD_LIBRARY_PATH spec'd ones.
63 */
64char	 **search_dirs;
65int	n_search_dirs;
66
67static const char *standard_search_dirs[] = {
68	STANDARD_SEARCH_DIRS
69};
70
71
72void
73add_search_dir(const char *name)
74{
75	int n;
76
77	for (n = 0; n < n_search_dirs; n++)
78		if (strcmp(search_dirs[n], name) == 0)
79			return;
80	n_search_dirs++;
81	search_dirs = (char **)
82		xrealloc(search_dirs, n_search_dirs * sizeof search_dirs[0]);
83	search_dirs[n_search_dirs - 1] = strdup(name);
84}
85
86void
87add_search_path(char *path)
88{
89	register char	*cp, *dup;
90
91	if (path == NULL)
92		return;
93
94	/* Add search directories from `path' */
95	path = dup = strdup(path);
96	while ((cp = strsep(&path, ":")) != NULL)
97		add_search_dir(cp);
98	free(dup);
99}
100
101void
102std_search_path(void)
103{
104	int	i, n;
105
106	/* Append standard search directories */
107	n = sizeof standard_search_dirs / sizeof standard_search_dirs[0];
108	for (i = 0; i < n; i++)
109		add_search_dir(standard_search_dirs[i]);
110}
111
112/*
113 * Return true if CP points to a valid dewey number.
114 * Decode and leave the result in the array DEWEY.
115 * Return the number of decoded entries in DEWEY.
116 */
117
118int
119getdewey(int dewey[], char *cp)
120{
121	int	i, n;
122
123	for (n = 0, i = 0; i < MAXDEWEY; i++) {
124		if (*cp == '\0')
125			break;
126
127		if (*cp == '.') cp++;
128		if (!isdigit(*cp))
129			return 0;
130
131		dewey[n++] = strtol(cp, &cp, 10);
132	}
133
134	return n;
135}
136
137/*
138 * Compare two dewey arrays.
139 * Return -1 if `d1' represents a smaller value than `d2'.
140 * Return  1 if `d1' represents a greater value than `d2'.
141 * Return  0 if equal.
142 */
143int
144cmpndewey(int d1[], int n1, int d2[], int n2)
145{
146	register int	i;
147
148	for (i = 0; i < n1 && i < n2; i++) {
149		if (d1[i] < d2[i])
150			return -1;
151		if (d1[i] > d2[i])
152			return 1;
153	}
154
155	if (n1 == n2)
156		return 0;
157
158	if (i == n1)
159		return -1;
160
161	if (i == n2)
162		return 1;
163
164	errx(1, "cmpndewey: can't happen");
165	return 0;
166}
167
168/*
169 * Search directories for a shared library matching the given
170 * major and minor version numbers.  See search_lib_dir() below for
171 * the detailed matching rules.
172 *
173 * As soon as a directory with an acceptable match is found, the search
174 * terminates.  Subsequent directories are not searched for a better
175 * match.  This is in conformance with the SunOS searching rules.  Also,
176 * it avoids a lot of directory searches that are virtually guaranteed to
177 * be fruitless.
178 *
179 * The return value is a full pathname to the matching library.  The
180 * string is dynamically allocated.  If no matching library is found, the
181 * function returns NULL.
182 */
183
184char *
185findshlib(char *name, int *majorp, int *minorp, int do_dot_a)
186{
187	int		i;
188
189	for (i = 0; i < n_search_dirs; i++) {
190		char	*path;
191
192		path = search_lib_dir(search_dirs[i], name, majorp, minorp,
193			do_dot_a);
194		if(path != NULL)
195			return path;
196	}
197
198	return NULL;
199}
200
201/*
202 * Search library directories for a file with the given name.  The
203 * return value is a full pathname to the matching file.  The string
204 * is dynamically allocated.  If no matching file is found, the function
205 * returns NULL.
206 */
207
208char *
209find_lib_file(const char *name)
210{
211	int		i;
212
213	for (i = 0; i < n_search_dirs; i++) {
214		char		*path = concat(search_dirs[i], "/", name);
215		struct stat	sb;
216
217		if (lstat(path, &sb) != -1)	/* We found it */
218			return path;
219
220		free(path);
221	}
222
223	return NULL;
224}
225
226/*
227 * Search a given directory for a library (preferably shared) satisfying
228 * the given criteria.
229 *
230 * The matching rules are as follows:
231 *
232 *	if(*majorp == -1)
233 *		find the library with the highest major version;
234 *	else
235 *		insist on a major version identical to *majorp;
236 *
237 *	Always find the library with the highest minor version;
238 *	if(*minorp != -1)
239 *		insist on a minor version >= *minorp;
240 *
241 * It is invalid to specify a specific minor number while wildcarding
242 * the major number.
243 *
244 * The actual major and minor numbers found are returned via the pointer
245 * arguments.
246 *
247 * A suitable shared library is always preferred over a static (.a) library.
248 * If do_dot_a is false, then a static library will not be accepted in
249 * any case.
250 *
251 * The return value is a full pathname to the matching library.  The
252 * string is dynamically allocated.  If no matching library is found, the
253 * function returns NULL.
254 */
255
256char *
257search_lib_dir(char *dir, char *name, int *majorp, int *minorp, int do_dot_a)
258{
259	size_t		namelen;
260	DIR		*dd;
261	struct dirent	*dp;
262	int		best_dewey[MAXDEWEY];
263	int		best_ndewey;
264	char		dot_a_name[MAXNAMLEN+1];
265	char		dot_so_name[MAXNAMLEN+1];
266
267	if((dd = opendir(dir)) == NULL)
268		return NULL;
269
270	namelen = strlen(name);
271	best_ndewey = 0;
272	dot_a_name[0] = '\0';
273	dot_so_name[0] = '\0';
274
275	while((dp = readdir(dd)) != NULL) {
276		char *extension;
277
278		if(strlen(dp->d_name) < 3 + namelen + 2 ||	/* lib+xxx+.a */
279		   strncmp(dp->d_name, "lib", 3) != 0 ||
280		   strncmp(dp->d_name + 3, name, namelen) != 0 ||
281		   dp->d_name[3+namelen] != '.')
282			continue;
283
284		extension = dp->d_name + 3 + namelen + 1;	/* a or so.* */
285
286		if(strncmp(extension, "so.", 3) == 0) {
287			int cur_dewey[MAXDEWEY];
288			int cur_ndewey;
289
290			cur_ndewey = getdewey(cur_dewey, extension+3);
291			if(cur_ndewey < 2)	/* Too few version numbers */
292				continue;
293
294			if(*majorp != -1) {	/* Need exact match on major */
295				if(cur_dewey[0] != *majorp)
296					continue;
297				if(*minorp != -1) {  /* Need minor >= minimum */
298					if(cur_dewey[1] < *minorp)
299						continue;
300				}
301			}
302
303			if(cmpndewey(cur_dewey, cur_ndewey, best_dewey,
304			   best_ndewey) <= 0)	/* No better than prior match */
305				continue;
306
307			/* We found a better match */
308			strcpy(dot_so_name, dp->d_name);
309			bcopy(cur_dewey, best_dewey,
310				cur_ndewey * sizeof best_dewey[0]);
311			best_ndewey = cur_ndewey;
312		} else if(do_dot_a && strcmp(extension, "a") == 0)
313			strcpy(dot_a_name, dp->d_name);
314	}
315	closedir(dd);
316
317	if(dot_so_name[0] != '\0') {
318		*majorp = best_dewey[0];
319		*minorp = best_dewey[1];
320		return concat(dir, "/", dot_so_name);
321	}
322
323	if(dot_a_name[0] != '\0')
324		return concat(dir, "/", dot_a_name);
325
326	return NULL;
327}
328