sod.c revision 1.18
1/* $OpenBSD: sod.c,v 1.18 2003/07/06 20:03:57 deraadt 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 goto backout; 100 break; 101 case 2: 102 /* major version extension */ 103 major = _dl_strtol(tok, &etok, 10); 104 if (*tok == '\0' || *etok != '\0') 105 goto backout; 106 break; 107 case 3: 108 /* minor version extension */ 109 minor = _dl_strtol(tok, &etok, 10); 110 if (*tok == '\0' || *etok != '\0') 111 goto backout; 112 break; 113 /* if we get here, it must be weird */ 114 default: 115 goto backout; 116 } 117 } 118 if (realname == NULL) 119 goto backout; 120 cp = (char *)sodp->sod_name; 121 sodp->sod_name = (long)_dl_strdup(realname); 122 _dl_free(cp); 123 sodp->sod_library = 1; 124 sodp->sod_major = major; 125 sodp->sod_minor = minor; 126 return; 127 128backout: 129 _dl_free((char *)sodp->sod_name); 130 sodp->sod_name = (long)_dl_strdup(name); 131} 132 133static struct hints_header *hheader = NULL; 134static struct hints_bucket *hbuckets; 135static char *hstrtab; 136char *_dl_hint_search_path = NULL; 137 138#define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1) 139 140void 141_dl_maphints(void) 142{ 143 struct stat sb; 144 caddr_t addr = MAP_FAILED; 145 long hsize = 0; 146 int hfd; 147 148 if ((hfd = _dl_open(_PATH_LD_HINTS, O_RDONLY)) < 0) 149 goto bad_hints; 150 151 if (_dl_fstat(hfd, &sb) != 0 || !S_ISREG(sb.st_mode) || 152 sb.st_size < sizeof(struct hints_header) || sb.st_size > LONG_MAX) 153 goto bad_hints; 154 155 hsize = (long)sb.st_size; 156 addr = (void *)_dl_mmap(0, hsize, PROT_READ, MAP_PRIVATE, hfd, 0); 157 if (addr == MAP_FAILED) 158 goto bad_hints; 159 160 hheader = (struct hints_header *)addr; 161 if (HH_BADMAG(*hheader) || hheader->hh_ehints > hsize) 162 goto bad_hints; 163 164 if (hheader->hh_version != LD_HINTS_VERSION_1 && 165 hheader->hh_version != LD_HINTS_VERSION_2) 166 goto bad_hints; 167 168 hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab); 169 hstrtab = (char *)(addr + hheader->hh_strtab); 170 if (hheader->hh_version >= LD_HINTS_VERSION_2) 171 _dl_hint_search_path = hstrtab + hheader->hh_dirlist; 172 173 /* close the file descriptor, leaving the hints mapped */ 174 _dl_close(hfd); 175 176 return; 177 178bad_hints: 179 if (addr != MAP_FAILED) 180 _dl_munmap(addr, hsize); 181 if (hfd != -1) 182 _dl_close(hfd); 183 hheader = (struct hints_header *)-1; 184} 185 186char * 187_dl_findhint(char *name, int major, int minor, char *prefered_path) 188{ 189 struct hints_bucket *bp; 190 191 /* 192 * If not mapped, and we have not tried before, try to map the 193 * hints, if previous attempts failed hheader is -1 and we 194 * do not wish to retry it. 195 */ 196 if (hheader == NULL) 197 _dl_maphints(); 198 199 /* if it failed to map, return failure */ 200 if (!(HINTS_VALID)) 201 return NULL; 202 203 bp = hbuckets + (_dl_hinthash(name, major, minor) % hheader->hh_nbucket); 204 205 while (1) { 206 /* Sanity check */ 207 if (bp->hi_namex >= hheader->hh_strtab_sz) { 208 _dl_printf("Bad name index: %#x\n", bp->hi_namex); 209 _dl_exit(7); 210 break; 211 } 212 if (bp->hi_pathx >= hheader->hh_strtab_sz) { 213 _dl_printf("Bad path index: %#x\n", bp->hi_pathx); 214 _dl_exit(7); 215 break; 216 } 217 218 if (_dl_strcmp(name, hstrtab + bp->hi_namex) == 0) { 219 /* It's `name', check version numbers */ 220 if (bp->hi_major == major && 221 (bp->hi_ndewey < 2 || bp->hi_minor >= minor)) { 222 if (prefered_path == NULL || 223 _dl_strncmp(prefered_path, 224 hstrtab + bp->hi_pathx, 225 _dl_strlen(prefered_path)) == 0) 226 return hstrtab + bp->hi_pathx; 227 } 228 } 229 230 if (bp->hi_next == -1) 231 break; 232 233 /* Move on to next in bucket */ 234 bp = &hbuckets[bp->hi_next]; 235 } 236 237 /* No hints available for name */ 238 return NULL; 239} 240 241int 242_dl_hinthash(char *cp, int vmajor, int vminor) 243{ 244 int k = 0; 245 246 while (*cp) 247 k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff; 248 249 k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff; 250 if (hheader->hh_version == LD_HINTS_VERSION_1) 251 k = (((k << 1) + (k >> 14)) ^ (vminor*167)) & 0x3fff; 252 253 return k; 254} 255