1 /* 2 * $FreeBSD$ 3 */ 4 5 #include <sys/param.h> 6 #include <sys/fcntl.h> 7 #include <sys/mman.h> 8 #include <sys/queue.h> 9 #include <sys/stat.h> 10 #include <errno.h> 11 #include <stdlib.h> 12 #include <string.h> 13 14 #include "debug.h" 15 #include "rtld.h" 16 #include "libmap.h" 17 18 #ifndef _PATH_LIBMAP_CONF 19 #define _PATH_LIBMAP_CONF "/etc/libmap.conf" 20 #endif 21 22 TAILQ_HEAD(lm_list, lm); 23 struct lm { 24 char *f; 25 char *t; 26 TAILQ_ENTRY(lm) lm_link; 27 }; 28 29 TAILQ_HEAD(lmp_list, lmp) lmp_head = TAILQ_HEAD_INITIALIZER(lmp_head); 30 struct lmp { 31 char *p; 32 enum { T_EXACT=0, T_BASENAME, T_DIRECTORY } type; 33 struct lm_list lml; 34 TAILQ_ENTRY(lmp) lmp_link; 35 }; 36 37 static int lm_count; 38 39 static void lmc_parse(char *, size_t); 40 static void lm_add(const char *, const char *, const char *); 41 static void lm_free(struct lm_list *); 42 static char *lml_find(struct lm_list *, const char *); 43 static struct lm_list *lmp_find(const char *); 44 static struct lm_list *lmp_init(char *); 45 static const char *quickbasename(const char *); 46 47 #define iseol(c) (((c) == '#') || ((c) == '\0') || \ 48 ((c) == '\n') || ((c) == '\r')) 49 50 /* 51 * Do not use ctype.h macros, which rely on working TLS. It is 52 * too early to have thread-local variables functional. 53 */ 54 #define rtld_isspace(c) ((c) == ' ' || (c) == '\t') 55 56 int 57 lm_init(char *libmap_override) 58 { 59 struct stat st; 60 char *lm_map, *p; 61 int fd; 62 63 dbg("lm_init(\"%s\")", libmap_override); 64 TAILQ_INIT(&lmp_head); 65 66 fd = open(_PATH_LIBMAP_CONF, O_RDONLY); 67 if (fd == -1) { 68 dbg("lm_init: open(\"%s\") failed, %s", _PATH_LIBMAP_CONF, 69 rtld_strerror(errno)); 70 goto override; 71 } 72 if (fstat(fd, &st) == -1) { 73 close(fd); 74 dbg("lm_init: fstat(\"%s\") failed, %s", _PATH_LIBMAP_CONF, 75 rtld_strerror(errno)); 76 goto override; 77 } 78 lm_map = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0); 79 if (lm_map == (const char *)MAP_FAILED) { 80 close(fd); 81 dbg("lm_init: mmap(\"%s\") failed, %s", _PATH_LIBMAP_CONF, 82 rtld_strerror(errno)); 83 goto override; 84 } 85 close(fd); 86 lmc_parse(lm_map, st.st_size); 87 munmap(lm_map, st.st_size); 88 89 override: 90 if (libmap_override) { 91 /* 92 * Do some character replacement to make $LIBMAP look 93 * like a text file, then parse it. 94 */ 95 libmap_override = xstrdup(libmap_override); 96 for (p = libmap_override; *p; p++) { 97 switch (*p) { 98 case '=': 99 *p = ' '; 100 break; 101 case ',': 102 *p = '\n'; 103 break; 104 } 105 } 106 lmc_parse(p, strlen(p)); 107 free(p); 108 } 109 110 return (lm_count == 0); 111 } 112 113 static void 114 lmc_parse(char *lm_p, size_t lm_len) 115 { 116 char *cp, *f, *t, *c, *p; 117 char prog[MAXPATHLEN]; 118 char line[MAXPATHLEN + 2]; 119 size_t cnt; 120 int i; 121 122 cnt = 0; 123 p = NULL; 124 while (cnt < lm_len) { 125 i = 0; 126 while (lm_p[cnt] != '\n' && cnt < lm_len && 127 i < sizeof(line) - 1) { 128 line[i] = lm_p[cnt]; 129 cnt++; 130 i++; 131 } 132 line[i] = '\0'; 133 while (lm_p[cnt] != '\n' && cnt < lm_len) 134 cnt++; 135 /* skip over nl */ 136 cnt++; 137 138 cp = &line[0]; 139 t = f = c = NULL; 140 141 /* Skip over leading space */ 142 while (rtld_isspace(*cp)) cp++; 143 144 /* Found a comment or EOL */ 145 if (iseol(*cp)) continue; 146 147 /* Found a constraint selector */ 148 if (*cp == '[') { 149 cp++; 150 151 /* Skip leading space */ 152 while (rtld_isspace(*cp)) cp++; 153 154 /* Found comment, EOL or end of selector */ 155 if (iseol(*cp) || *cp == ']') 156 continue; 157 158 c = cp++; 159 /* Skip to end of word */ 160 while (!rtld_isspace(*cp) && !iseol(*cp) && *cp != ']') 161 cp++; 162 163 /* Skip and zero out trailing space */ 164 while (rtld_isspace(*cp)) *cp++ = '\0'; 165 166 /* Check if there is a closing brace */ 167 if (*cp != ']') continue; 168 169 /* Terminate string if there was no trailing space */ 170 *cp++ = '\0'; 171 172 /* 173 * There should be nothing except whitespace or comment 174 from this point to the end of the line. 175 */ 176 while(rtld_isspace(*cp)) cp++; 177 if (!iseol(*cp)) continue; 178 179 strcpy(prog, c); 180 p = prog; 181 continue; 182 } 183 184 /* Parse the 'from' candidate. */ 185 f = cp++; 186 while (!rtld_isspace(*cp) && !iseol(*cp)) cp++; 187 188 /* Skip and zero out the trailing whitespace */ 189 while (rtld_isspace(*cp)) *cp++ = '\0'; 190 191 /* Found a comment or EOL */ 192 if (iseol(*cp)) continue; 193 194 /* Parse 'to' mapping */ 195 t = cp++; 196 while (!rtld_isspace(*cp) && !iseol(*cp)) cp++; 197 198 /* Skip and zero out the trailing whitespace */ 199 while (rtld_isspace(*cp)) *cp++ = '\0'; 200 201 /* Should be no extra tokens at this point */ 202 if (!iseol(*cp)) continue; 203 204 *cp = '\0'; 205 lm_add(p, f, t); 206 } 207 } 208 209 static void 210 lm_free (struct lm_list *lml) 211 { 212 struct lm *lm; 213 214 dbg("%s(%p)", __func__, lml); 215 216 while (!TAILQ_EMPTY(lml)) { 217 lm = TAILQ_FIRST(lml); 218 TAILQ_REMOVE(lml, lm, lm_link); 219 free(lm->f); 220 free(lm->t); 221 free(lm); 222 } 223 return; 224 } 225 226 void 227 lm_fini (void) 228 { 229 struct lmp *lmp; 230 231 dbg("%s()", __func__); 232 233 while (!TAILQ_EMPTY(&lmp_head)) { 234 lmp = TAILQ_FIRST(&lmp_head); 235 TAILQ_REMOVE(&lmp_head, lmp, lmp_link); 236 free(lmp->p); 237 lm_free(&lmp->lml); 238 free(lmp); 239 } 240 return; 241 } 242 243 static void 244 lm_add (const char *p, const char *f, const char *t) 245 { 246 struct lm_list *lml; 247 struct lm *lm; 248 249 if (p == NULL) 250 p = "$DEFAULT$"; 251 252 dbg("%s(\"%s\", \"%s\", \"%s\")", __func__, p, f, t); 253 254 if ((lml = lmp_find(p)) == NULL) 255 lml = lmp_init(xstrdup(p)); 256 257 lm = xmalloc(sizeof(struct lm)); 258 lm->f = xstrdup(f); 259 lm->t = xstrdup(t); 260 TAILQ_INSERT_HEAD(lml, lm, lm_link); 261 lm_count++; 262 } 263 264 char * 265 lm_find (const char *p, const char *f) 266 { 267 struct lm_list *lml; 268 char *t; 269 270 dbg("%s(\"%s\", \"%s\")", __func__, p, f); 271 272 if (p != NULL && (lml = lmp_find(p)) != NULL) { 273 t = lml_find(lml, f); 274 if (t != NULL) { 275 /* 276 * Add a global mapping if we have 277 * a successful constrained match. 278 */ 279 lm_add(NULL, f, t); 280 return (t); 281 } 282 } 283 lml = lmp_find("$DEFAULT$"); 284 if (lml != NULL) 285 return (lml_find(lml, f)); 286 else 287 return (NULL); 288 } 289 290 static char * 291 lml_find (struct lm_list *lmh, const char *f) 292 { 293 struct lm *lm; 294 295 dbg("%s(%p, \"%s\")", __func__, lmh, f); 296 297 TAILQ_FOREACH(lm, lmh, lm_link) 298 if (strcmp(f, lm->f) == 0) 299 return (lm->t); 300 return (NULL); 301 } 302 303 /* Given an executable name, return a pointer to the translation list or 304 NULL if no matches */ 305 static struct lm_list * 306 lmp_find (const char *n) 307 { 308 struct lmp *lmp; 309 310 dbg("%s(\"%s\")", __func__, n); 311 312 TAILQ_FOREACH(lmp, &lmp_head, lmp_link) 313 if ((lmp->type == T_EXACT && strcmp(n, lmp->p) == 0) || 314 (lmp->type == T_DIRECTORY && strncmp(n, lmp->p, strlen(lmp->p)) == 0) || 315 (lmp->type == T_BASENAME && strcmp(quickbasename(n), lmp->p) == 0)) 316 return (&lmp->lml); 317 return (NULL); 318 } 319 320 static struct lm_list * 321 lmp_init (char *n) 322 { 323 struct lmp *lmp; 324 325 dbg("%s(\"%s\")", __func__, n); 326 327 lmp = xmalloc(sizeof(struct lmp)); 328 lmp->p = n; 329 if (n[strlen(n)-1] == '/') 330 lmp->type = T_DIRECTORY; 331 else if (strchr(n,'/') == NULL) 332 lmp->type = T_BASENAME; 333 else 334 lmp->type = T_EXACT; 335 TAILQ_INIT(&lmp->lml); 336 TAILQ_INSERT_HEAD(&lmp_head, lmp, lmp_link); 337 338 return (&lmp->lml); 339 } 340 341 /* libc basename is overkill. Return a pointer to the character after the 342 last /, or the original string if there are no slashes. */ 343 static const char * 344 quickbasename (const char *path) 345 { 346 const char *p = path; 347 for (; *path; path++) { 348 if (*path == '/') 349 p = path+1; 350 } 351 return (p); 352 } 353