sod.c revision 1.19
1/* $OpenBSD: sod.c,v 1.19 2003/10/26 23:23:12 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#include <syscall.h> 47 48#include "archdep.h" 49#include "util.h" 50#include "sod.h" 51 52int _dl_hinthash(char *cp, int vmajor, int vminor); 53void _dl_maphints(void); 54 55/* 56 * Populate sod struct for dlopen's call to map_object 57 */ 58void 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 return; 73 74 /* is this a filename? */ 75 if (_dl_strchr((char *)sodp->sod_name, '/')) 76 return; 77 78 /* skip over 'lib' */ 79 cp = (char *)sodp->sod_name + 3; 80 81 /* dot guardian */ 82 if ((_dl_strchr(cp, '.') == NULL) || (*(cp+_dl_strlen(cp)-1) == '.')) 83 return; 84 85 /* default */ 86 major = minor = -1; 87 88 realname = NULL; 89 /* loop through name - parse skipping name */ 90 for (tuplet = 0; (tok = strsep(&cp, ".")) != NULL; tuplet++) { 91 switch (tuplet) { 92 case 0: 93 /* removed 'lib' and extensions from name */ 94 realname = tok; 95 break; 96 case 1: 97 /* 'so' extension */ 98 if (_dl_strcmp(tok, "so") != 0) { 99 /* 100 * filenames such as libX-A.B.so.X.Y 101 * screw this up, decrement tuplet 102 * and try to continue. 103 */ 104 tuplet--; 105 } 106 break; 107 case 2: 108 /* major version extension */ 109 major = _dl_strtol(tok, &etok, 10); 110 if (*tok == '\0' || *etok != '\0') 111 goto backout; 112 break; 113 case 3: 114 /* minor version extension */ 115 minor = _dl_strtol(tok, &etok, 10); 116 if (*tok == '\0' || *etok != '\0') 117 goto backout; 118 break; 119 /* if we get here, it must be weird */ 120 default: 121 goto backout; 122 } 123 } 124 if (realname == NULL) 125 goto backout; 126 cp = (char *)sodp->sod_name; 127 sodp->sod_name = (long)_dl_strdup(realname); 128 _dl_free(cp); 129 sodp->sod_library = 1; 130 sodp->sod_major = major; 131 sodp->sod_minor = minor; 132 return; 133 134backout: 135 _dl_free((char *)sodp->sod_name); 136 sodp->sod_name = (long)_dl_strdup(name); 137} 138 139static struct hints_header *hheader = NULL; 140static struct hints_bucket *hbuckets; 141static char *hstrtab; 142char *_dl_hint_search_path = NULL; 143 144#define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1) 145 146void 147_dl_maphints(void) 148{ 149 struct stat sb; 150 caddr_t addr = MAP_FAILED; 151 long hsize = 0; 152 int hfd; 153 154 if ((hfd = _dl_open(_PATH_LD_HINTS, O_RDONLY)) < 0) 155 goto bad_hints; 156 157 if (_dl_fstat(hfd, &sb) != 0 || !S_ISREG(sb.st_mode) || 158 sb.st_size < sizeof(struct hints_header) || sb.st_size > LONG_MAX) 159 goto bad_hints; 160 161 hsize = (long)sb.st_size; 162 addr = (void *)_dl_mmap(0, hsize, PROT_READ, MAP_PRIVATE, hfd, 0); 163 if (addr == MAP_FAILED) 164 goto bad_hints; 165 166 hheader = (struct hints_header *)addr; 167 if (HH_BADMAG(*hheader) || hheader->hh_ehints > hsize) 168 goto bad_hints; 169 170 if (hheader->hh_version != LD_HINTS_VERSION_1 && 171 hheader->hh_version != LD_HINTS_VERSION_2) 172 goto bad_hints; 173 174 hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab); 175 hstrtab = (char *)(addr + hheader->hh_strtab); 176 if (hheader->hh_version >= LD_HINTS_VERSION_2) 177 _dl_hint_search_path = hstrtab + hheader->hh_dirlist; 178 179 /* close the file descriptor, leaving the hints mapped */ 180 _dl_close(hfd); 181 182 return; 183 184bad_hints: 185 if (addr != MAP_FAILED) 186 _dl_munmap(addr, hsize); 187 if (hfd != -1) 188 _dl_close(hfd); 189 hheader = (struct hints_header *)-1; 190} 191 192char * 193_dl_findhint(char *name, int major, int minor, char *prefered_path) 194{ 195 struct hints_bucket *bp; 196 197 /* 198 * If not mapped, and we have not tried before, try to map the 199 * hints, if previous attempts failed hheader is -1 and we 200 * do not wish to retry it. 201 */ 202 if (hheader == NULL) 203 _dl_maphints(); 204 205 /* if it failed to map, return failure */ 206 if (!(HINTS_VALID)) 207 return NULL; 208 209 bp = hbuckets + (_dl_hinthash(name, major, minor) % hheader->hh_nbucket); 210 211 while (1) { 212 /* Sanity check */ 213 if (bp->hi_namex >= hheader->hh_strtab_sz) { 214 _dl_printf("Bad name index: %#x\n", bp->hi_namex); 215 _dl_exit(7); 216 break; 217 } 218 if (bp->hi_pathx >= hheader->hh_strtab_sz) { 219 _dl_printf("Bad path index: %#x\n", bp->hi_pathx); 220 _dl_exit(7); 221 break; 222 } 223 224 if (_dl_strcmp(name, hstrtab + bp->hi_namex) == 0) { 225 /* It's `name', check version numbers */ 226 if (bp->hi_major == major && 227 (bp->hi_ndewey < 2 || bp->hi_minor >= minor)) { 228 if (prefered_path == NULL || 229 _dl_strncmp(prefered_path, 230 hstrtab + bp->hi_pathx, 231 _dl_strlen(prefered_path)) == 0) 232 return hstrtab + bp->hi_pathx; 233 } 234 } 235 236 if (bp->hi_next == -1) 237 break; 238 239 /* Move on to next in bucket */ 240 bp = &hbuckets[bp->hi_next]; 241 } 242 243 /* No hints available for name */ 244 return NULL; 245} 246 247int 248_dl_hinthash(char *cp, int vmajor, int vminor) 249{ 250 int k = 0; 251 252 while (*cp) 253 k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff; 254 255 k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff; 256 if (hheader->hh_version == LD_HINTS_VERSION_1) 257 k = (((k << 1) + (k >> 14)) ^ (vminor*167)) & 0x3fff; 258 259 return k; 260} 261