sod.c revision 1.30
1/* $OpenBSD: sod.c,v 1.30 2014/07/09 12:54:03 guenther 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/mman.h> 36#include <machine/exec.h> 37#include <limits.h> 38#include <stdio.h> 39#include <fcntl.h> 40#include <nlist.h> 41#include <link.h> 42#include <limits.h> 43#include <string.h> 44#include <stdlib.h> 45#include <unistd.h> 46 47#include "syscall.h" 48#include "archdep.h" 49#include "path.h" 50#include "util.h" 51#include "sod.h" 52 53int _dl_hinthash(char *cp, int vmajor, int vminor); 54void _dl_maphints(void); 55 56/* 57 * Populate sod struct for dlopen's call to map_object 58 */ 59void 60_dl_build_sod(const char *name, struct sod *sodp) 61{ 62 unsigned int tuplet; 63 int major, minor; 64 char *realname, *tok, *etok, *cp; 65 66 /* default is an absolute or relative path */ 67 /* XXX */ 68 sodp->sod_name = (long)_dl_strdup(name); /* strtok is destructive */ 69 sodp->sod_library = 0; 70 sodp->sod_major = sodp->sod_minor = 0; 71 72 /* does it look like /^lib/ ? */ 73 if (_dl_strncmp((char *)sodp->sod_name, "lib", 3) != 0) 74 goto backout; 75 76 /* is this a filename? */ 77 if (_dl_strchr((char *)sodp->sod_name, '/')) 78 goto backout; 79 80 /* skip over 'lib' */ 81 cp = (char *)sodp->sod_name + 3; 82 83 realname = cp; 84 85 /* dot guardian */ 86 if ((_dl_strchr(cp, '.') == NULL) || (*(cp+_dl_strlen(cp)-1) == '.')) 87 goto backout; 88 89 cp = _dl_strstr(cp, ".so"); 90 if (cp == NULL) 91 goto backout; 92 93 /* default */ 94 major = minor = -1; 95 96 /* loop through name - parse skipping name */ 97 for (tuplet = 0; (tok = _dl_strsep(&cp, ".")) != NULL; tuplet++) { 98 switch (tuplet) { 99 case 0: 100 /* empty tok, we already skipped to "\.so.*" */ 101 break; 102 case 1: 103 /* 'so' extension */ 104 break; 105 case 2: 106 /* major version extension */ 107 major = _dl_strtol(tok, &etok, 10); 108 if (*tok == '\0' || *etok != '\0') 109 goto backout; 110 break; 111 case 3: 112 /* minor version extension */ 113 minor = _dl_strtol(tok, &etok, 10); 114 if (*tok == '\0' || *etok != '\0') 115 goto backout; 116 break; 117 /* if we get here, it must be weird */ 118 default: 119 goto backout; 120 } 121 } 122 if (realname == NULL) 123 goto backout; 124 cp = (char *)sodp->sod_name; 125 /* XXX */ 126 sodp->sod_name = (long)_dl_strdup(realname); 127 _dl_free(cp); 128 sodp->sod_library = 1; 129 sodp->sod_major = major; 130 sodp->sod_minor = minor; 131 return; 132 133backout: 134 _dl_free((char *)sodp->sod_name); 135 /* XXX */ 136 sodp->sod_name = (long)_dl_strdup(name); 137} 138 139void 140_dl_set_sod(const char *path, struct sod *sod) 141{ 142 char *fname = _dl_strrchr(path, '/'); 143 144 if (fname != NULL) 145 _dl_build_sod(++fname, sod); 146 else 147 _dl_build_sod(path, sod); 148} 149 150static struct hints_header *hheader = NULL; 151static struct hints_bucket *hbuckets; 152static char *hstrtab; 153char **_dl_hint_search_path = NULL; 154 155#define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1) 156 157void 158_dl_maphints(void) 159{ 160 struct stat sb; 161 caddr_t addr = MAP_FAILED; 162 long hsize = 0; 163 int hfd; 164 165 if ((hfd = _dl_open(_PATH_LD_HINTS, O_RDONLY | O_CLOEXEC)) < 0) 166 goto bad_hints; 167 168 if (_dl_fstat(hfd, &sb) != 0 || !S_ISREG(sb.st_mode) || 169 sb.st_size < sizeof(struct hints_header) || sb.st_size > LONG_MAX) 170 goto bad_hints; 171 172 hsize = (long)sb.st_size; 173 addr = (void *)_dl_mmap(0, hsize, PROT_READ, MAP_PRIVATE, hfd, 0); 174 if (_dl_mmap_error(addr)) 175 goto bad_hints; 176 177 hheader = (struct hints_header *)addr; 178 if (HH_BADMAG(*hheader) || hheader->hh_ehints > hsize) 179 goto bad_hints; 180 181 if (hheader->hh_version != LD_HINTS_VERSION_1 && 182 hheader->hh_version != LD_HINTS_VERSION_2) 183 goto bad_hints; 184 185 hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab); 186 hstrtab = (char *)(addr + hheader->hh_strtab); 187 if (hheader->hh_version >= LD_HINTS_VERSION_2) 188 _dl_hint_search_path = _dl_split_path(hstrtab + hheader->hh_dirlist); 189 190 /* close the file descriptor, leaving the hints mapped */ 191 _dl_close(hfd); 192 193 return; 194 195bad_hints: 196 if (!_dl_mmap_error(addr)) 197 _dl_munmap(addr, hsize); 198 if (hfd != -1) 199 _dl_close(hfd); 200 hheader = (struct hints_header *)-1; 201} 202 203char * 204_dl_findhint(char *name, int major, int minor, char *preferred_path) 205{ 206 struct hints_bucket *bp; 207 208 /* 209 * If not mapped, and we have not tried before, try to map the 210 * hints, if previous attempts failed hheader is -1 and we 211 * do not wish to retry it. 212 */ 213 if (hheader == NULL) 214 _dl_maphints(); 215 216 /* if it failed to map, return failure */ 217 if (!(HINTS_VALID)) 218 return NULL; 219 220 if (hheader->hh_nbucket == 0) 221 return NULL; 222 223 bp = hbuckets + (_dl_hinthash(name, major, minor) % hheader->hh_nbucket); 224 225 while (1) { 226 /* Sanity check */ 227 if (bp->hi_namex >= hheader->hh_strtab_sz) { 228 _dl_printf("Bad name index: %#x\n", bp->hi_namex); 229 _dl_exit(7); 230 break; 231 } 232 if (bp->hi_pathx >= hheader->hh_strtab_sz) { 233 _dl_printf("Bad path index: %#x\n", bp->hi_pathx); 234 _dl_exit(7); 235 break; 236 } 237 238 if (_dl_strcmp(name, hstrtab + bp->hi_namex) == 0) { 239 /* It's `name', check version numbers */ 240 if (bp->hi_major == major && 241 (bp->hi_ndewey < 2 || bp->hi_minor >= minor)) { 242 if (preferred_path == NULL) { 243 return hstrtab + bp->hi_pathx; 244 } else { 245 char *path = hstrtab + bp->hi_pathx; 246 char *edir = _dl_strrchr(path, '/'); 247 248 if ((_dl_strncmp(preferred_path, path, 249 (edir - path)) == 0) && 250 (preferred_path[edir - path] == '\0')) 251 return path; 252 } 253 } 254 } 255 256 if (bp->hi_next == -1) 257 break; 258 259 /* Move on to next in bucket */ 260 bp = &hbuckets[bp->hi_next]; 261 } 262 263 /* No hints available for name */ 264 return NULL; 265} 266 267int 268_dl_hinthash(char *cp, int vmajor, int vminor) 269{ 270 int k = 0; 271 272 while (*cp) 273 k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff; 274 275 k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff; 276 if (hheader->hh_version == LD_HINTS_VERSION_1) 277 k = (((k << 1) + (k >> 14)) ^ (vminor*167)) & 0x3fff; 278 279 return k; 280} 281