summaryrefslogtreecommitdiffstats
path: root/libexec/rtld-aout/shlib.c
blob: 989cf45d8ab11c1de8b6e60a04a1498b92733400 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
/*
 * Copyright (c) 1993 Paul Kranenburg
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Paul Kranenburg.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/time.h>
#include <a.out.h>
#include <ctype.h>
#include <dirent.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <link.h>
#include "shlib.h"
#include "support.h"

/*
 * Standard directories to search for files specified by -l.
 */
#ifndef STANDARD_SEARCH_DIRS
#define STANDARD_SEARCH_DIRS    "/usr/lib/aout"
#endif

/*
 * Actual vector of library search directories,
 * including `-L'ed and LD_LIBRARY_PATH spec'd ones.
 */
char	 **search_dirs;
int	n_search_dirs;

char	*standard_search_dirs[] = {
	STANDARD_SEARCH_DIRS
};


void
add_search_dir(name)
	char	*name;
{
	int n;

	for (n = 0; n < n_search_dirs; n++)
		if (strcmp(search_dirs[n], name) == 0)
			return;
	n_search_dirs++;
	search_dirs = (char **)
		xrealloc(search_dirs, n_search_dirs * sizeof search_dirs[0]);
	search_dirs[n_search_dirs - 1] = strdup(name);
}

void
add_search_path(path)
char	*path;
{
	register char	*cp, *dup;

	if (path == NULL)
		return;

	/* Add search directories from `path' */
	path = dup = strdup(path);
	while ((cp = strsep(&path, ":")) != NULL)
		add_search_dir(cp);
	free(dup);
}

void
std_search_path()
{
	int	i, n;

	/* Append standard search directories */
	n = sizeof standard_search_dirs / sizeof standard_search_dirs[0];
	for (i = 0; i < n; i++)
		add_search_dir(standard_search_dirs[i]);
}

/*
 * Return true if CP points to a valid dewey number.
 * Decode and leave the result in the array DEWEY.
 * Return the number of decoded entries in DEWEY.
 */

int
getdewey(dewey, cp)
int	dewey[];
char	*cp;
{
	int	i, n;

	for (n = 0, i = 0; i < MAXDEWEY; i++) {
		if (*cp == '\0')
			break;

		if (*cp == '.') cp++;
		if (!isdigit(*cp))
			return 0;

		dewey[n++] = strtol(cp, &cp, 10);
	}

	return n;
}

/*
 * Compare two dewey arrays.
 * Return -1 if `d1' represents a smaller value than `d2'.
 * Return  1 if `d1' represents a greater value than `d2'.
 * Return  0 if equal.
 */
int
cmpndewey(d1, n1, d2, n2)
int	d1[], d2[];
int	n1, n2;
{
	register int	i;

	for (i = 0; i < n1 && i < n2; i++) {
		if (d1[i] < d2[i])
			return -1;
		if (d1[i] > d2[i])
			return 1;
	}

	if (n1 == n2)
		return 0;

	if (i == n1)
		return -1;

	if (i == n2)
		return 1;

	errx(1, "cmpndewey: cant happen");
	return 0;
}

/*
 * Search directories for a shared library matching the given
 * major and minor version numbers.  See search_lib_dir() below for
 * the detailed matching rules.
 *
 * As soon as a directory with an acceptable match is found, the search
 * terminates.  Subsequent directories are not searched for a better
 * match.  This is in conformance with the SunOS searching rules.  Also,
 * it avoids a lot of directory searches that are virtually guaranteed to
 * be fruitless.
 *
 * The return value is a full pathname to the matching library.  The
 * string is dynamically allocated.  If no matching library is found, the
 * function returns NULL.
 */

char *
findshlib(name, majorp, minorp, do_dot_a)
char	*name;
int	*majorp, *minorp;
int	do_dot_a;
{
	int		i;

	for (i = 0; i < n_search_dirs; i++) {
		char	*path;

		path = search_lib_dir(search_dirs[i], name, majorp, minorp,
			do_dot_a);
		if(path != NULL)
			return path;
	}

	return NULL;
}

/*
 * Search library directories for a file with the given name.  The
 * return value is a full pathname to the matching file.  The string
 * is dynamically allocated.  If no matching file is found, the function
 * returns NULL.
 */

char *
find_lib_file(name)
	const char	*name;
{
	int		i;

	for (i = 0; i < n_search_dirs; i++) {
		char		*path = concat(search_dirs[i], "/", name);
		struct stat	sb;

		if (lstat(path, &sb) != -1)	/* We found it */
			return path;

		free(path);
	}

	return NULL;
}

/*
 * Search a given directory for a library (preferably shared) satisfying
 * the given criteria.
 *
 * The matching rules are as follows:
 *
 *	if(*majorp == -1)
 *		find the library with the highest major version;
 *	else
 *		insist on a major version identical to *majorp;
 *
 *	Always find the library with the highest minor version;
 *	if(*minorp != -1)
 *		insist on a minor version >= *minorp;
 *
 * It is invalid to specify a specific minor number while wildcarding
 * the major number.
 *
 * The actual major and minor numbers found are returned via the pointer
 * arguments.
 *
 * A suitable shared library is always preferred over a static (.a) library.
 * If do_dot_a is false, then a static library will not be accepted in
 * any case.
 *
 * The return value is a full pathname to the matching library.  The
 * string is dynamically allocated.  If no matching library is found, the
 * function returns NULL.
 */

char *
search_lib_dir(dir, name, majorp, minorp, do_dot_a)
	char		*dir;
	char		*name;
	int		*majorp;
	int		*minorp;
	int		do_dot_a;
{
	int		namelen;
	DIR		*dd;
	struct dirent	*dp;
	int		best_dewey[MAXDEWEY];
	int		best_ndewey;
	char		dot_a_name[MAXNAMLEN+1];
	char		dot_so_name[MAXNAMLEN+1];

	if((dd = opendir(dir)) == NULL)
		return NULL;

	namelen = strlen(name);
	best_ndewey = 0;
	dot_a_name[0] = '\0';
	dot_so_name[0] = '\0';

	while((dp = readdir(dd)) != NULL) {
		char *extension;

		if(strlen(dp->d_name) < 3 + namelen + 2 ||	/* lib+xxx+.a */
		   strncmp(dp->d_name, "lib", 3) != 0 ||
		   strncmp(dp->d_name + 3, name, namelen) != 0 ||
		   dp->d_name[3+namelen] != '.')
			continue;

		extension = dp->d_name + 3 + namelen + 1;	/* a or so.* */

		if(strncmp(extension, "so.", 3) == 0) {
			int cur_dewey[MAXDEWEY];
			int cur_ndewey;

			cur_ndewey = getdewey(cur_dewey, extension+3);
			if(cur_ndewey < 2)	/* Too few version numbers */
				continue;

			if(*majorp != -1) {	/* Need exact match on major */
				if(cur_dewey[0] != *majorp)
					continue;
				if(*minorp != -1) {  /* Need minor >= minimum */
					if(cur_dewey[1] < *minorp)
						continue;
				}
			}

			if(cmpndewey(cur_dewey, cur_ndewey, best_dewey,
			   best_ndewey) <= 0)	/* No better than prior match */
				continue;

			/* We found a better match */
			strcpy(dot_so_name, dp->d_name);
			bcopy(cur_dewey, best_dewey,
				cur_ndewey * sizeof best_dewey[0]);
			best_ndewey = cur_ndewey;
		} else if(do_dot_a && strcmp(extension, "a") == 0)
			strcpy(dot_a_name, dp->d_name);
	}
	closedir(dd);

	if(dot_so_name[0] != '\0') {
		*majorp = best_dewey[0];
		*minorp = best_dewey[1];
		return concat(dir, "/", dot_so_name);
	}

	if(dot_a_name[0] != '\0')
		return concat(dir, "/", dot_a_name);

	return NULL;
}
OpenPOWER on IntegriCloud