sod.c revision 1.23
1/* $OpenBSD: sod.c,v 1.23 2008/10/02 20:12:08 kurt 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 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 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 130backout: 131 _dl_free((char *)sodp->sod_name); 132 sodp->sod_name = (long)_dl_strdup(name); 133} 134 135static struct hints_header *hheader = NULL; 136static struct hints_bucket *hbuckets; 137static char *hstrtab; 138char *_dl_hint_search_path = NULL; 139 140#define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1) 141 142void 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 (_dl_mmap_error(addr)) 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 180bad_hints: 181 if (!_dl_mmap_error(addr)) 182 _dl_munmap(addr, hsize); 183 if (hfd != -1) 184 _dl_close(hfd); 185 hheader = (struct hints_header *)-1; 186} 187 188char * 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 249int 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