1 /* $OpenBSD: sod.c,v 1.22 2004/10/17 03:56:49 drahn Exp $ */
2
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 */
33
34 #include <sys/types.h>
35 #include <sys/syslimits.h>
36 #include <stdio.h>
37 #include <fcntl.h>
38 #include <nlist.h>
39 #include <link.h>
40 #include <limits.h>
41 #include <machine/exec.h>
42 #include <sys/mman.h>
43 #include <string.h>
44 #include <stdlib.h>
45 #include <unistd.h>
46
47 #include "syscall.h"
48 #include "archdep.h"
49 #include "util.h"
50 #include "sod.h"
51
52 int _dl_hinthash(char *cp, int vmajor, int vminor);
53 void _dl_maphints(void);
54
55 /*
56 * Populate sod struct for dlopen's call to map_object
57 */
58 void
_dl_build_sod(const char * name,struct sod * sodp)59 _dl_build_sod(const char *name, struct sod *sodp)
60 {
61 unsigned int tuplet;
62 int major, minor;
63 char *realname, *tok, *etok, *cp;
64
65 /* default is an absolute or relative path */
66 sodp->sod_name = (long)_dl_strdup(name); /* strtok is destructive */
67 sodp->sod_library = 0;
68 sodp->sod_major = sodp->sod_minor = 0;
69
70 /* does it look like /^lib/ ? */
71 if (_dl_strncmp((char *)sodp->sod_name, "lib", 3) != 0)
72 goto backout;
73
74 /* is this a filename? */
75 if (_dl_strchr((char *)sodp->sod_name, '/'))
76 goto backout;
77
78 /* skip over 'lib' */
79 cp = (char *)sodp->sod_name + 3;
80
81 realname = cp;
82
83 /* dot guardian */
84 if ((_dl_strchr(cp, '.') == NULL) || (*(cp+_dl_strlen(cp)-1) == '.'))
85 goto backout;
86
87 cp = _dl_strstr(cp, ".so");
88 if (cp == NULL)
89 goto backout;
90
91 /* default */
92 major = minor = -1;
93
94 /* loop through name - parse skipping name */
95 for (tuplet = 0; (tok = strsep(&cp, ".")) != NULL; tuplet++) {
96 switch (tuplet) {
97 case 0:
98 /* empty tok, we already skipped to "\.so.*" */
99 break;
100 case 1:
101 /* 'so' extension */
102 break;
103 case 2:
104 /* major version extension */
105 major = _dl_strtol(tok, &etok, 10);
106 if (*tok == '\0' || *etok != '\0')
107 goto backout;
108 break;
109 case 3:
110 /* minor version extension */
111 minor = _dl_strtol(tok, &etok, 10);
112 if (*tok == '\0' || *etok != '\0')
113 goto backout;
114 break;
115 /* if we get here, it must be weird */
116 default:
117 goto backout;
118 }
119 }
120 if (realname == NULL)
121 goto backout;
122 cp = (char *)sodp->sod_name;
123 sodp->sod_name = (long)_dl_strdup(realname);
124 _dl_free(cp);
125 sodp->sod_library = 1;
126 sodp->sod_major = major;
127 sodp->sod_minor = minor;
128 return;
129
130 backout:
131 _dl_free((char *)sodp->sod_name);
132 sodp->sod_name = (long)_dl_strdup(name);
133 }
134
135 static struct hints_header *hheader = NULL;
136 static struct hints_bucket *hbuckets;
137 static char *hstrtab;
138 char *_dl_hint_search_path = NULL;
139
140 #define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1)
141
142 void
_dl_maphints(void)143 _dl_maphints(void)
144 {
145 struct stat sb;
146 caddr_t addr = MAP_FAILED;
147 long hsize = 0;
148 int hfd;
149
150 if ((hfd = _dl_open(_PATH_LD_HINTS, O_RDONLY)) < 0)
151 goto bad_hints;
152
153 if (_dl_fstat(hfd, &sb) != 0 || !S_ISREG(sb.st_mode) ||
154 sb.st_size < sizeof(struct hints_header) || sb.st_size > LONG_MAX)
155 goto bad_hints;
156
157 hsize = (long)sb.st_size;
158 addr = (void *)_dl_mmap(0, hsize, PROT_READ, MAP_PRIVATE, hfd, 0);
159 if (addr == MAP_FAILED)
160 goto bad_hints;
161
162 hheader = (struct hints_header *)addr;
163 if (HH_BADMAG(*hheader) || hheader->hh_ehints > hsize)
164 goto bad_hints;
165
166 if (hheader->hh_version != LD_HINTS_VERSION_1 &&
167 hheader->hh_version != LD_HINTS_VERSION_2)
168 goto bad_hints;
169
170 hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab);
171 hstrtab = (char *)(addr + hheader->hh_strtab);
172 if (hheader->hh_version >= LD_HINTS_VERSION_2)
173 _dl_hint_search_path = hstrtab + hheader->hh_dirlist;
174
175 /* close the file descriptor, leaving the hints mapped */
176 _dl_close(hfd);
177
178 return;
179
180 bad_hints:
181 if (addr != MAP_FAILED)
182 _dl_munmap(addr, hsize);
183 if (hfd != -1)
184 _dl_close(hfd);
185 hheader = (struct hints_header *)-1;
186 }
187
188 char *
_dl_findhint(char * name,int major,int minor,char * preferred_path)189 _dl_findhint(char *name, int major, int minor, char *preferred_path)
190 {
191 struct hints_bucket *bp;
192
193 /*
194 * If not mapped, and we have not tried before, try to map the
195 * hints, if previous attempts failed hheader is -1 and we
196 * do not wish to retry it.
197 */
198 if (hheader == NULL)
199 _dl_maphints();
200
201 /* if it failed to map, return failure */
202 if (!(HINTS_VALID))
203 return NULL;
204
205 bp = hbuckets + (_dl_hinthash(name, major, minor) % hheader->hh_nbucket);
206
207 while (1) {
208 /* Sanity check */
209 if (bp->hi_namex >= hheader->hh_strtab_sz) {
210 _dl_printf("Bad name index: %#x\n", bp->hi_namex);
211 _dl_exit(7);
212 break;
213 }
214 if (bp->hi_pathx >= hheader->hh_strtab_sz) {
215 _dl_printf("Bad path index: %#x\n", bp->hi_pathx);
216 _dl_exit(7);
217 break;
218 }
219
220 if (_dl_strcmp(name, hstrtab + bp->hi_namex) == 0) {
221 /* It's `name', check version numbers */
222 if (bp->hi_major == major &&
223 (bp->hi_ndewey < 2 || bp->hi_minor >= minor)) {
224 if (preferred_path == NULL) {
225 return hstrtab + bp->hi_pathx;
226 } else {
227 char *path = hstrtab + bp->hi_pathx;
228 char *edir = _dl_strrchr(path, '/');
229
230 if ((_dl_strncmp(preferred_path, path,
231 (edir - path)) == 0) &&
232 (preferred_path[edir - path] == '\0'))
233 return path;
234 }
235 }
236 }
237
238 if (bp->hi_next == -1)
239 break;
240
241 /* Move on to next in bucket */
242 bp = &hbuckets[bp->hi_next];
243 }
244
245 /* No hints available for name */
246 return NULL;
247 }
248
249 int
_dl_hinthash(char * cp,int vmajor,int vminor)250 _dl_hinthash(char *cp, int vmajor, int vminor)
251 {
252 int k = 0;
253
254 while (*cp)
255 k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff;
256
257 k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff;
258 if (hheader->hh_version == LD_HINTS_VERSION_1)
259 k = (((k << 1) + (k >> 14)) ^ (vminor*167)) & 0x3fff;
260
261 return k;
262 }
263