1/* $OpenBSD: sod.c,v 1.7 2015/10/29 13:07:41 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/stat.h> 36#include <sys/mman.h> 37#include <machine/exec.h> 38#include <limits.h> 39#include <stdio.h> 40#include <fcntl.h> 41#include <nlist.h> 42#include <link.h> 43#include <string.h> 44#include <stdlib.h> 45#include <unistd.h> 46 47#if 0 48#include "syscall.h" 49#include "archdep.h" 50#include "util.h" 51#endif 52#include "path.h" 53#include "sod.h" 54 55int _dl_hinthash(char *cp, int vmajor, int vminor); 56void _dl_maphints(void); 57 58/* 59 * Populate sod struct for dlopen's call to map_object 60 */ 61void 62_dl_build_sod(const char *name, struct sod *sodp) 63{ 64 unsigned int tuplet; 65 int major, minor; 66 char *realname, *tok, *etok, *cp; 67 68 /* default is an absolute or relative path */ 69 sodp->sod_name = (long)strdup(name); /* strtok is destructive */ 70 if (sodp->sod_name == 0) 71 exit(7); 72 sodp->sod_library = 0; 73 sodp->sod_major = sodp->sod_minor = 0; 74 75 /* does it look like /^lib/ ? */ 76 if (strncmp((char *)sodp->sod_name, "lib", 3) != 0) 77 goto backout; 78 79 /* is this a filename? */ 80 if (strchr((char *)sodp->sod_name, '/')) 81 goto backout; 82 83 /* skip over 'lib' */ 84 cp = (char *)sodp->sod_name + 3; 85 86 realname = cp; 87 88 /* dot guardian */ 89 if ((strchr(cp, '.') == NULL) || (*(cp+strlen(cp)-1) == '.')) 90 goto backout; 91 92 cp = strstr(cp, ".so"); 93 if (cp == NULL) 94 goto backout; 95 96 /* default */ 97 major = minor = -1; 98 99 /* loop through name - parse skipping name */ 100 for (tuplet = 0; (tok = strsep(&cp, ".")) != NULL; tuplet++) { 101 switch (tuplet) { 102 case 0: 103 /* empty tok, we already skipped to "\.so.*" */ 104 break; 105 case 1: 106 /* 'so' extension */ 107 break; 108 case 2: 109 /* major version extension */ 110 major = strtol(tok, &etok, 10); 111 if (*tok == '\0' || *etok != '\0') 112 goto backout; 113 break; 114 case 3: 115 /* minor version extension */ 116 minor = strtol(tok, &etok, 10); 117 if (*tok == '\0' || *etok != '\0') 118 goto backout; 119 break; 120 /* if we get here, it must be weird */ 121 default: 122 goto backout; 123 } 124 } 125 if (realname == NULL) 126 goto backout; 127 cp = (char *)sodp->sod_name; 128 sodp->sod_name = (long)strdup(realname); 129 if (sodp->sod_name == 0) 130 exit(7); 131 free(cp); 132 sodp->sod_library = 1; 133 sodp->sod_major = major; 134 sodp->sod_minor = minor; 135 return; 136 137backout: 138 free((char *)sodp->sod_name); 139 sodp->sod_name = (long)strdup(name); 140 if (sodp->sod_name == 0) 141 exit(7); 142} 143 144static struct hints_header *hheader = NULL; 145static struct hints_bucket *hbuckets; 146static char *hstrtab; 147char **_dl_hint_search_path = NULL; 148 149#define HINTS_VALID (hheader != NULL && hheader != (struct hints_header *)-1) 150 151void 152_dl_maphints(void) 153{ 154 struct stat sb; 155 caddr_t addr = MAP_FAILED; 156 long hsize = 0; 157 int hfd; 158 159 if ((hfd = open(_PATH_LD_HINTS, O_RDONLY)) < 0) 160 goto bad_hints; 161 162 if (fstat(hfd, &sb) != 0 || !S_ISREG(sb.st_mode) || 163 sb.st_size < sizeof(struct hints_header) || sb.st_size > LONG_MAX) 164 goto bad_hints; 165 166 hsize = (long)sb.st_size; 167 addr = (void *)mmap(0, hsize, PROT_READ, MAP_PRIVATE, hfd, 0); 168 if (addr == MAP_FAILED) 169 goto bad_hints; 170 171 hheader = (struct hints_header *)addr; 172 if (HH_BADMAG(*hheader) || hheader->hh_ehints > hsize) 173 goto bad_hints; 174 175 if (hheader->hh_version != LD_HINTS_VERSION_2) 176 goto bad_hints; 177 178 hbuckets = (struct hints_bucket *)(addr + hheader->hh_hashtab); 179 hstrtab = (char *)(addr + hheader->hh_strtab); 180 if (hheader->hh_version >= LD_HINTS_VERSION_2) 181 _dl_hint_search_path = _dl_split_path(hstrtab + hheader->hh_dirlist); 182 183 /* close the file descriptor, leaving the hints mapped */ 184 close(hfd); 185 186 return; 187 188bad_hints: 189 if (addr != MAP_FAILED) 190 munmap(addr, hsize); 191 if (hfd != -1) 192 close(hfd); 193 hheader = (struct hints_header *)-1; 194} 195 196char * 197_dl_findhint(char *name, int major, int minor, char *preferred_path) 198{ 199 struct hints_bucket *bp; 200 201 /* 202 * If not mapped, and we have not tried before, try to map the 203 * hints, if previous attempts failed hheader is -1 and we 204 * do not wish to retry it. 205 */ 206 if (hheader == NULL) 207 _dl_maphints(); 208 209 /* if it failed to map, return failure */ 210 if (!(HINTS_VALID)) 211 return NULL; 212 213 if (hheader->hh_nbucket == 0) 214 return NULL; 215 216 bp = hbuckets + (_dl_hinthash(name, major, minor) % hheader->hh_nbucket); 217 218 while (1) { 219 /* Sanity check */ 220 if (bp->hi_namex >= hheader->hh_strtab_sz) { 221 printf("Bad name index: %#x\n", bp->hi_namex); 222 exit(7); 223 break; 224 } 225 if (bp->hi_pathx >= hheader->hh_strtab_sz) { 226 printf("Bad path index: %#x\n", bp->hi_pathx); 227 exit(7); 228 break; 229 } 230 231 if (strcmp(name, hstrtab + bp->hi_namex) == 0) { 232 /* It's `name', check version numbers */ 233 if (bp->hi_major == major && 234 (bp->hi_ndewey < 2 || bp->hi_minor >= minor)) { 235 if (preferred_path == NULL) { 236 return hstrtab + bp->hi_pathx; 237 } else { 238 char *path = hstrtab + bp->hi_pathx; 239 char *edir = strrchr(path, '/'); 240 241 if ((strncmp(preferred_path, path, 242 (edir - path)) == 0) && 243 (preferred_path[edir - path] == '\0')) 244 return path; 245 } 246 } 247 } 248 249 if (bp->hi_next == -1) 250 break; 251 252 /* Move on to next in bucket */ 253 bp = &hbuckets[bp->hi_next]; 254 } 255 256 /* No hints available for name */ 257 return NULL; 258} 259 260int 261_dl_hinthash(char *cp, int vmajor, int vminor) 262{ 263 int k = 0; 264 265 while (*cp) 266 k = (((k << 1) + (k >> 14)) ^ (*cp++)) & 0x3fff; 267 268 k = (((k << 1) + (k >> 14)) ^ (vmajor*257)) & 0x3fff; 269 270 return k; 271} 272