utils/ldconfig.c

   1 /*
   2  * ldconfig - update shared library symlinks
   3  *
   4  * usage: ldconfig [-DvqnNX] [-f conf] [-C cache] [-r root] dir ...
   5  *        ldconfig -l [-Dv] lib ...
   6  *        ldconfig -p
   7  *        -D: debug mode, don't update links
   8  *        -v: verbose mode, print things as we go
   9  *        -q: quiet mode, don't print warnings
  10  *        -n: don't process standard directories
  11  *        -N: don't update the library cache
  12  *        -X: don't update the library links
  13  *        -l: library mode, manually link libraries
  14  *        -p: print the current library cache
  15  *        -f conf: use conf instead of /etc/ld.so.conf
  16  *        -C cache: use cache instead of /etc/ld.so.cache
  17  *        -r root: first, do a chroot to the indicated directory
  18  *        dir ...: directories to process
  19  *        lib ...: libraries to link
  20  *
  21  * Copyright 1994-2000 David Engel and Mitch D'Souza
  22  *
  23  * This program may be used for any purpose as long as this
  24  * copyright notice is kept.
  25  *
  26  * 2005/09/16: Dan Howell (modified for cross-development)
  27  */
  28
  29 #include "porting.h"
  30
  31 #define BUFFER_SIZE 4096
  32
  33 struct exec {
  34         unsigned long a_info;   /* Use macros N_MAGIC, etc for access */
  35         unsigned a_text;        /* length of text, in bytes */
  36         unsigned a_data;        /* length of data, in bytes */
  37         unsigned a_bss;         /* length of uninitialized data area for file, in bytes */
  38         unsigned a_syms;        /* length of symbol table data in file, in bytes */
  39         unsigned a_entry;       /* start address */
  40         unsigned a_trsize;      /* length of relocation info for text, in bytes */
  41         unsigned a_drsize;      /* length of relocation info for data, in bytes */
  42 };
  43
  44 #if !defined (N_MAGIC)
  45 #define N_MAGIC(exec) ((exec).a_info & 0xffff)
  46 #endif
  47 #define N_MAGIC_SWAP(exec) (bswap_32((exec).a_info) & 0xffff)
  48 /* Code indicating object file or impure executable.  */
  49 #define OMAGIC 0407
  50 /* Code indicating pure executable.  */
  51 #define NMAGIC 0410
  52 /* Code indicating demand-paged executable.  */
  53 #define ZMAGIC 0413
  54 /* This indicates a demand-paged executable with the header in the text.
  55    The first page is unmapped to help trap NULL pointer references */
  56 #define QMAGIC 0314
  57 /* Code indicating core file.  */
  58 #define CMAGIC 0421
  59
  60 char *___strtok = NULL;
  61
  62 char *prog = NULL;
  63 int debug = 0;                  /* debug mode */
  64 int verbose = 0;                /* verbose mode */
  65 int libmode = 0;                /* library mode */
  66 int nolinks = 0;                /* don't update links */
  67 int nocache = 0;                /* don't build cache */
  68 void cache_print(void);
  69 void cache_write(void);
  70 void cache_dolib(const char *dir, const char *so, int libtype);
  71 #ifdef __LDSO_CACHE_SUPPORT__
  72 char *conffile = LDSO_CONF;     /* default conf file */
  73 char *cachefile = LDSO_CACHE;   /* default cache file */
  74 #endif
  75 char *chroot_dir = NULL;
  76 int byteswap = 0;
  77
  78 struct needed_tab {
  79         char *soname;
  80         int type;
  81 };
  82
  83 struct needed_tab needed_tab[] = {
  84         {"libc.so.0", LIB_ELF_LIBC0},
  85         {"libm.so.0", LIB_ELF_LIBC0},
  86         {"libdl.so.0", LIB_ELF_LIBC0},
  87         {"libc.so.5", LIB_ELF_LIBC5},
  88         {"libm.so.5", LIB_ELF_LIBC5},
  89         {"libdl.so.1", LIB_ELF_LIBC5},
  90         {"libc.so.6", LIB_ELF_LIBC6},
  91         {"libm.so.6", LIB_ELF_LIBC6},
  92         {"libdl.so.2", LIB_ELF_LIBC6},
  93         {NULL, LIB_ELF}
  94 };
  95
  96 extern char *chroot_realpath(const char *chroot, const char *path,
  97                              char resolved_path[]);
  98
  99 /* These two are used internally -- you shouldn't need to use them */
 100 static void verror_msg(const char *s, va_list p)
 101 {
 102         fflush(stdout);
 103         fprintf(stderr, "%s: ", prog);
 104         vfprintf(stderr, s, p);
 105 }
 106
 107 static void warnx(const char *s, ...)
 108 {
 109         va_list p;
 110
 111         va_start(p, s);
 112         verror_msg(s, p);
 113         va_end(p);
 114         fprintf(stderr, "\n");
 115 }
 116
 117 static void err(int errnum, const char *s, ...) attribute_noreturn;
 118 static void err(int errnum, const char *s, ...)
 119 {
 120         va_list p;
 121
 122         va_start(p, s);
 123         verror_msg(s, p);
 124         va_end(p);
 125         fprintf(stderr, "\n");
 126         exit(errnum);
 127 }
 128
 129 static void vperror_msg(const char *s, va_list p)
 130 {
 131         int e = errno;
 132
 133         if (s == 0)
 134                 s = "";
 135         verror_msg(s, p);
 136         if (*s)
 137                 s = ": ";
 138         fprintf(stderr, "%s%s\n", s, strerror(e));
 139 }
 140
 141 static void warn(const char *s, ...)
 142 {
 143         va_list p;
 144
 145         va_start(p, s);
 146         vperror_msg(s, p);
 147         va_end(p);
 148 }
 149
 150 static void *xmalloc(size_t size)
 151 {
 152         void *ptr;
 153         if ((ptr = malloc(size)) == NULL)
 154                 err(EXIT_FAILURE, "out of memory");
 155         return ptr;
 156 }
 157
 158 static char *xstrdup(const char *str)
 159 {
 160         char *ptr;
 161         if ((ptr = strdup(str)) == NULL)
 162                 err(EXIT_FAILURE, "out of memory");
 163         return ptr;
 164 }
 165
 166 #undef __ELF_NATIVE_CLASS
 167 #undef readsonameXX
 168 #define readsonameXX readsoname32
 169 #define __ELF_NATIVE_CLASS 32
 170 #include "readsoname2.c"
 171
 172 #undef __ELF_NATIVE_CLASS
 173 #undef readsonameXX
 174 #define readsonameXX readsoname64
 175 #define __ELF_NATIVE_CLASS 64
 176 #include "readsoname2.c"
 177 static char *readsoname(char *name, FILE *infile, int expected_type,
 178                         int *type, int elfclass)
 179 {
 180         char *res;
 181
 182         if (elfclass == ELFCLASS32)
 183                 res = readsoname32(name, infile, expected_type, type);
 184         else {
 185                 res = readsoname64(name, infile, expected_type, type);
 186 #if 0
 187                 /* relies on multilib support which we dont have ... */
 188                 *type |= LIB_ELF64;
 189 #endif
 190         }
 191
 192         return res;
 193 }
 194
 195 /* If shared library, return a malloced copy of the soname and set the
 196  * type, else return NULL.
 197  *
 198  * expected_type should be either LIB_ANY or one of the following:-
 199  * LIB_DLL
 200  * LIB_ELF
 201  * LIB_ELF_LIBC5
 202  * LIB_ELF_LIBC6
 203  *
 204  * If the lib is ELF and we can not deduce the type the type will
 205  * be set based on expected_type.
 206  *
 207  * If the expected, actual/deduced types missmatch we display a warning
 208  * and use the actual/deduced type.
 209  */
 210 static char *is_shlib(const char *dir, const char *name, int *type,
 211                       int *islink, int expected_type)
 212 {
 213         char *good = NULL;
 214         char *cp, *cp2;
 215         FILE *file;
 216         struct exec exec;
 217         ElfW(Ehdr) *elf_hdr;
 218         struct stat statbuf;
 219         char buff[BUFFER_SIZE];
 220         char real[BUFFER_SIZE];
 221         static int byteswapflag = -1;   /* start with byte-order unknown */
 222
 223         /* see if name is of the form *.so* */
 224         if (name[strlen(name) - 1] != '~' && (cp = strstr(name, ".so"))) {
 225                 /* find the start of the Vminor part, if any */
 226                 if (cp[3] == '.' && (cp2 = strchr(cp + 4, '.')))
 227                         cp = cp2;
 228                 else
 229                         cp = cp + strlen(cp);
 230
 231                 /* construct the full path name */
 232                 sprintf(buff, "%s%s%s", dir, (*dir && strcmp(dir, "/")) ? "/" : "", name);
 233
 234                 /* get real path in case of chroot */
 235                 if (!chroot_realpath(chroot_dir, buff, real))
 236                         warn("can't resolve %s in chroot %s", buff, chroot_dir);
 237
 238                 /* first, make sure it's a regular file */
 239                 if (lstat(real, &statbuf))
 240                         warn("skipping %s", buff);
 241                 else if (!S_ISREG(statbuf.st_mode) && !S_ISLNK(statbuf.st_mode))
 242                         warnx("%s is not a regular file or symlink, skipping", buff);
 243                 else {
 244                         /* is it a regular file or a symlink */
 245                         *islink = S_ISLNK(statbuf.st_mode);
 246
 247                         /* then try opening it */
 248                         if (!(file = fopen(real, "rb")))
 249                                 warn("skipping %s", buff);
 250                         else {
 251                                 /* now make sure it's a shared library */
 252                                 if (fread(&exec, sizeof exec, 1, file) < 1)
 253                                         warnx("can't read header from %s, skipping", buff);
 254                                 else if (N_MAGIC(exec) != ZMAGIC
 255                                  && N_MAGIC(exec) != QMAGIC
 256                                  && N_MAGIC_SWAP(exec) != ZMAGIC
 257                                  && N_MAGIC_SWAP(exec) != QMAGIC) {
 258                                         elf_hdr = (ElfW(Ehdr) *) & exec;
 259                                         if (elf_hdr->e_ident[0] != 0x7f ||
 260                                             strncmp((char *)elf_hdr->e_ident + 1, "ELF", 3) != 0)
 261                                         {
 262                                                 /* silently ignore linker scripts */
 263                                                 if (strncmp((char *)&exec, "/* GNU ld", 9) != 0)
 264                                                         warnx("%s is not a shared library, skipping", buff);
 265                                         } else {
 266                                                 /* always call readsoname to update type */
 267                                                 if (expected_type == LIB_DLL) {
 268                                                         warnx("%s is not an a.out library, it's ELF!", buff);
 269                                                         expected_type = LIB_ANY;
 270                                                 }
 271                                                 *type = LIB_ELF;
 272                                                 good = readsoname(buff, file, expected_type, type,
 273                                                                   elf_hdr->e_ident[EI_CLASS]);
 274                                                 if (byteswapflag == -1)
 275                                                         /* byte-order detected */
 276                                                         byteswapflag = byteswap;
 277                                                 if (good == NULL || *islink) {
 278                                                         if (good != NULL)
 279                                                                 free(good);
 280                                                         good = xstrdup(name);
 281                                                 } else {
 282                                                         /* if the soname does not match the filename,
 283                                                            issue a warning, but only in debug mode. */
 284                                                         int len = strlen(good);
 285                                                         if (debug && (strncmp(good, name, len) != 0
 286                                                             || (name[len] != '\0' && name[len] != '.')))
 287                                                                 warnx("%s has inconsistent soname (%s)", buff, good);
 288                                                 }
 289                                         }
 290                                 } else {
 291                                         /* Determine byte-order */
 292                                         byteswap = (N_MAGIC(exec) == ZMAGIC || N_MAGIC(exec) == QMAGIC) ? 0 : 1;
 293                                         if (byteswapflag == -1)
 294                                                 /* byte-order detected */
 295                                                 byteswapflag = byteswap;
 296
 297                                         if (*islink)
 298                                                 good = xstrdup(name);
 299                                         else {
 300                                                 good = xmalloc(cp - name + 1);
 301                                                 strncpy(good, name, cp - name);
 302                                                 good[cp - name] = '\0';
 303                                         }
 304                                         if (expected_type != LIB_ANY && expected_type != LIB_DLL) {
 305                                                 warnx("%s is not an ELF library, its an a.out DLL!", buff);
 306                                                 expected_type = LIB_ANY;
 307                                         }
 308
 309                                         *type = LIB_DLL;
 310                                 }
 311                                 fclose(file);
 312
 313                                 if (byteswapflag >= 0 && byteswap != byteswapflag) {
 314                                         byteswapflag = -2;
 315                                         warnx("mixed byte-order detected, using host byte-order...");
 316                                 }
 317                                 if (byteswapflag == -2)
 318                                         byteswap = 0;
 319                         }
 320                 }
 321         }
 322
 323         return good;
 324 }
 325
 326 /* update the symlink to new library */
 327 static void link_shlib(const char *dir, const char *file, const char *so)
 328 {
 329         int change = 1;
 330         char libname[BUFFER_SIZE];
 331         char linkname[BUFFER_SIZE];
 332         char reallibname[BUFFER_SIZE];
 333         char reallinkname[BUFFER_SIZE];
 334         struct stat libstat;
 335         struct stat linkstat;
 336
 337         /* construct the full path names */
 338         sprintf(libname, "%s/%s", dir, file);
 339         sprintf(linkname, "%s/%s", dir, so);
 340         if (!chroot_realpath(chroot_dir, libname, reallibname))
 341                 warn("can't resolve %s in chroot %s", libname, chroot_dir);
 342         if (!chroot_realpath(chroot_dir, linkname, reallinkname))
 343                 warn("can't resolve %s in chroot %s", linkname, chroot_dir);
 344
 345         /* see if a link already exists */
 346         if (!stat(reallinkname, &linkstat)) {
 347                 /* now see if it's the one we want */
 348                 if (stat(reallibname, &libstat))
 349                         warn("can't stat %s", libname);
 350                 else if (libstat.st_dev == linkstat.st_dev &&
 351                          libstat.st_ino == linkstat.st_ino)
 352                         change = 0;
 353         }
 354
 355         /* then update the link, if required */
 356         if (change > 0 && !nolinks) {
 357                 if (!lstat(reallinkname, &linkstat)) {
 358                         if (!S_ISLNK(linkstat.st_mode)) {
 359                                 warnx("%s is not a symlink", linkname);
 360                                 change = -1;
 361                         } else if (remove(reallinkname)) {
 362                                 warn("can't unlink %s", linkname);
 363                                 change = -1;
 364                         }
 365                 }
 366                 if (change > 0) {
 367                         if (symlink(file, reallinkname)) {
 368                                 warn("can't link %s to %s", linkname, file);
 369                                 change = -1;
 370                         }
 371                 }
 372         }
 373
 374         /* some people like to know what we're doing */
 375         if (verbose > 0)
 376                 printf("\t%s => %s%s\n", so, file,
 377                        change < 0 ? " (SKIPPED)" :
 378                        (change > 0 ? " (changed)" : ""));
 379
 380         return;
 381 }
 382
 383 /* figure out which library is greater */
 384 static int libcmp(char *p1, char *p2)
 385 {
 386         while (*p1) {
 387                 if (isdigit(*p1) && isdigit(*p2)) {
 388                         /* must compare this numerically */
 389                         int v1, v2;
 390                         v1 = strtoul(p1, &p1, 10);
 391                         v2 = strtoul(p2, &p2, 10);
 392                         if (v1 != v2)
 393                                 return v1 - v2;
 394                 } else if (isdigit(*p1) && !isdigit(*p2))
 395                         return 1;
 396                 else if (!isdigit(*p1) && isdigit(*p2))
 397                         return -1;
 398                 else if (*p1 != *p2)
 399                         return *p1 - *p2;
 400                 else
 401                         p1++, p2++;
 402         }
 403
 404         return *p1 - *p2;
 405 }
 406
 407 struct lib {
 408         char *so;               /* soname of a library */
 409         char *name;             /* name of a library */
 410         int libtype;            /* type of a library */
 411         int islink;             /* is it a symlink */
 412         struct lib *next;       /* next library in list */
 413 };
 414
 415 /* update all shared library links in a directory */
 416 static void scan_dir(const char *rawname)
 417 {
 418         DIR *dir;
 419         const char *name;
 420         struct dirent *ent;
 421         char *so, *path, *path_n;
 422         struct lib *lp, *libs = NULL;
 423         int i, libtype, islink, expected_type = LIB_ANY;
 424         char realname[BUFFER_SIZE];
 425
 426         /* We need a writable copy of this string */
 427         path = strdup(rawname);
 428         if (!path) {
 429                 err(EXIT_FAILURE, "Out of memory!\n");
 430         }
 431         /* Eliminate all double //s */
 432         path_n = path;
 433         while ((path_n = strstr(path_n, "//"))) {
 434                 i = strlen(path_n);
 435                 memmove(path_n, path_n + 1, i - 1);
 436                 *(path_n + i - 1) = '\0';
 437         }
 438         name = path;
 439
 440 #if 0
 441         char *t;
 442         /* Check for an embedded expected type */
 443         t = strrchr(name, '=');
 444         if (t) {
 445                 *t++ = '\0';    /* Skip = char */
 446                 if (strcasecmp(t, "libc4") == 0) {
 447                         expected_type = LIB_DLL;
 448                 } else {
 449                         if (strcasecmp(t, "libc5") == 0) {
 450                                 expected_type = LIB_ELF_LIBC5;
 451                         } else {
 452                                 if (strcasecmp(t, "libc6") == 0) {
 453                                         expected_type = LIB_ELF_LIBC6;
 454                                 } else {
 455                                         if (strcasecmp(t, "libc0") == 0) {
 456                                                 expected_type = LIB_ELF_LIBC0;
 457                                         } else {
 458                                                 warnx("Unknown type field '%s' for dir '%s' - ignored", t, name);
 459                                                 expected_type = LIB_ANY;
 460                                         }
 461                                 }
 462                         }
 463                 }
 464         }
 465 #endif
 466
 467         /* let 'em know what's going on */
 468         if (verbose > 0)
 469                 printf("%s:\n", name);
 470
 471         /* get real path in case of chroot */
 472         if (!chroot_realpath(chroot_dir, name, realname))
 473                 warn("can't resolve %s in chroot %s", name, chroot_dir);
 474
 475         /* if we can't open it, we can't do anything */
 476         if ((dir = opendir(realname)) == NULL) {
 477                 warn("skipping %s", name);
 478                 free(path);
 479                 return;
 480         }
 481
 482         /* yes, we have to look at every single file */
 483         while ((ent = readdir(dir)) != NULL) {
 484                 /* if it's not a shared library, don't bother */
 485                 if ((so = is_shlib(name, ent->d_name, &libtype, &islink, expected_type)) == NULL)
 486                         continue;
 487
 488                 /* have we already seen one with the same so name? */
 489                 for (lp = libs; lp; lp = lp->next) {
 490                         if (strcmp(so, lp->so) == 0) {
 491                                 /* we have, which one do we want to use? */
 492                                 if ((!islink && lp->islink) ||
 493                                     (islink == lp->islink &&
 494                                      libcmp(ent->d_name, lp->name) > 0)) {
 495                                         /* let's use the new one */
 496                                         free(lp->name);
 497                                         lp->name = xstrdup(ent->d_name);
 498                                         lp->libtype = libtype;
 499                                         lp->islink = islink;
 500                                 }
 501                                 break;
 502                         }
 503                 }
 504
 505                 /* congratulations, you're the first one we've seen */
 506                 if (!lp) {
 507                         lp = xmalloc(sizeof *lp);
 508                         lp->so = xstrdup(so);
 509                         lp->name = xstrdup(ent->d_name);
 510                         lp->libtype = libtype;
 511                         lp->islink = islink;
 512                         lp->next = libs;
 513                         libs = lp;
 514                 }
 515
 516                 free(so);
 517         }
 518
 519         /* don't need this any more */
 520         closedir(dir);
 521
 522         /* now we have all the latest libs, update the links */
 523         for (lp = libs; lp; lp = lp->next) {
 524                 if (!lp->islink)
 525                         link_shlib(name, lp->name, lp->so);
 526                 if (!nocache)
 527                         cache_dolib(name, lp->so, lp->libtype);
 528         }
 529
 530         /* always try to clean up after ourselves */
 531         while (libs) {
 532                 lp = libs->next;
 533                 free(libs->so);
 534                 free(libs->name);
 535                 free(libs);
 536                 libs = lp;
 537         }
 538
 539         free(path);
 540         return;
 541 }
 542
 543 #ifndef __LDSO_CACHE_SUPPORT__
 544 void cache_print(void)
 545 {
 546         printf("Library cache disabled\n");
 547 }
 548 void cache_dolib(const char *dir, const char *so, int libtype)
 549 {
 550         return;
 551 }
 552 void cache_write(void)
 553 {
 554         return;
 555 }
 556 #else
 557 /* return the list of system-specific directories */
 558 static char *get_extpath(void)
 559 {
 560         char *res = NULL, *cp;
 561         FILE *file;
 562         struct stat st;
 563         char realconffile[BUFFER_SIZE];
 564
 565         if (!chroot_realpath(chroot_dir, conffile, realconffile))
 566                 return NULL;
 567
 568         if ((file = fopen(realconffile, "r")) != NULL) {
 569                 fstat(fileno(file), &st);
 570                 res = xmalloc(st.st_size + 1);
 571                 (void)fread(res, 1, st.st_size, file);
 572                 fclose(file);
 573                 res[st.st_size] = '\0';
 574
 575                 /* convert comments fo spaces */
 576                 for (cp = res; *cp; /*nada */ ) {
 577                         if (*cp == '#') {
 578                                 do
 579                                         *cp++ = ' ';
 580                                 while (*cp && *cp != '\n');
 581                         } else {
 582                                 cp++;
 583                         }
 584                 }
 585         }
 586
 587         return res;
 588 }
 589
 590 typedef struct liblist {
 591         int flags;
 592         int sooffset;
 593         int liboffset;
 594         char *soname;
 595         char *libname;
 596         struct liblist *next;
 597 } liblist_t;
 598
 599 static header_t magic = { LDSO_CACHE_MAGIC, LDSO_CACHE_VER, 0 };
 600 static liblist_t *lib_head = NULL;
 601
 602 static int liblistcomp(liblist_t *x, liblist_t *y)
 603 {
 604         int res;
 605
 606         if ((res = libcmp(x->soname, y->soname)) == 0) {
 607                 res = libcmp(strrchr(x->libname, '/') + 1,
 608                              strrchr(y->libname, '/') + 1);
 609         }
 610
 611         return res;
 612 }
 613
 614 void cache_dolib(const char *dir, const char *so, int libtype)
 615 {
 616         char fullpath[PATH_MAX];
 617         liblist_t *new_lib, *cur_lib;
 618
 619         magic.nlibs++;
 620         sprintf(fullpath, "%s/%s", dir, so);
 621         new_lib = xmalloc(sizeof(liblist_t));
 622         new_lib->flags = libtype;
 623         new_lib->soname = xstrdup(so);
 624         new_lib->libname = xstrdup(fullpath);
 625
 626         if (lib_head == NULL || liblistcomp(new_lib, lib_head) > 0) {
 627                 new_lib->next = lib_head;
 628                 lib_head = new_lib;
 629         } else {
 630                 for (cur_lib = lib_head; cur_lib->next != NULL &&
 631                      liblistcomp(new_lib, cur_lib->next) <= 0;
 632                      cur_lib = cur_lib->next)
 633                         /* nothing */ ;
 634                 new_lib->next = cur_lib->next;
 635                 cur_lib->next = new_lib;
 636         }
 637 }
 638
 639 void cache_write(void)
 640 {
 641         int cachefd;
 642         int stroffset = 0;
 643         char realcachefile[BUFFER_SIZE];
 644         char tempfile[BUFFER_SIZE];
 645         header_t swap_magic;
 646         header_t *magic_ptr;
 647         libentry_t swap_lib;
 648         libentry_t *lib_ptr;
 649         liblist_t *cur_lib;
 650
 651         if (!magic.nlibs)
 652                 return;
 653
 654         if (!chroot_realpath(chroot_dir, cachefile, realcachefile))
 655                 err(EXIT_FAILURE, "can't resolve %s in chroot %s (%s)",
 656                     cachefile, chroot_dir, strerror(errno));
 657
 658         sprintf(tempfile, "%s~", realcachefile);
 659
 660         if (unlink(tempfile) && errno != ENOENT)
 661                 err(EXIT_FAILURE, "can't unlink %s~ (%s)", cachefile,
 662                     strerror(errno));
 663
 664         if ((cachefd = creat(tempfile, 0644)) < 0)
 665                 err(EXIT_FAILURE, "can't create %s~ (%s)", cachefile,
 666                     strerror(errno));
 667
 668         if (byteswap) {
 669                 swap_magic = magic;
 670                 swap_magic.nlibs = bswap_32(swap_magic.nlibs);
 671                 magic_ptr = &swap_magic;
 672         } else {
 673                 magic_ptr = &magic;
 674         }
 675         if (write(cachefd, magic_ptr, sizeof(header_t)) != sizeof(header_t))
 676                 err(EXIT_FAILURE, "can't write %s~ (%s)", cachefile,
 677                     strerror(errno));
 678
 679         for (cur_lib = lib_head; cur_lib != NULL; cur_lib = cur_lib->next) {
 680                 cur_lib->sooffset = stroffset;
 681                 stroffset += strlen(cur_lib->soname) + 1;
 682                 cur_lib->liboffset = stroffset;
 683                 stroffset += strlen(cur_lib->libname) + 1;
 684                 if (byteswap) {
 685                         swap_lib.flags = bswap_32(cur_lib->flags);
 686                         swap_lib.sooffset = bswap_32(cur_lib->sooffset);
 687                         swap_lib.liboffset = bswap_32(cur_lib->liboffset);
 688                         lib_ptr = &swap_lib;
 689                 } else {
 690                         lib_ptr = (libentry_t *) cur_lib;
 691                 }
 692                 if (write(cachefd, lib_ptr, sizeof(libentry_t)) !=
 693                     sizeof(libentry_t))
 694                         err(EXIT_FAILURE, "can't write %s~ (%s)", cachefile,
 695                             strerror(errno));
 696         }
 697
 698         for (cur_lib = lib_head; cur_lib != NULL; cur_lib = cur_lib->next) {
 699                 if ((size_t)write(cachefd, cur_lib->soname, strlen(cur_lib->soname) + 1)
 700                     != strlen(cur_lib->soname) + 1)
 701                         err(EXIT_FAILURE, "can't write %s~ (%s)", cachefile,
 702                             strerror(errno));
 703                 if ((size_t)write(cachefd, cur_lib->libname, strlen(cur_lib->libname) + 1)
 704                     != strlen(cur_lib->libname) + 1)
 705                         err(EXIT_FAILURE, "can't write %s~ (%s)", cachefile,
 706                             strerror(errno));
 707         }
 708
 709         if (close(cachefd))
 710                 err(EXIT_FAILURE, "can't close %s~ (%s)", cachefile,
 711                     strerror(errno));
 712
 713         if (chmod(tempfile, 0644))
 714                 err(EXIT_FAILURE, "can't chmod %s~ (%s)", cachefile,
 715                     strerror(errno));
 716
 717         if (rename(tempfile, realcachefile))
 718                 err(EXIT_FAILURE, "can't rename %s~ (%s)", cachefile,
 719                     strerror(errno));
 720 }
 721
 722 void cache_print(void)
 723 {
 724         caddr_t c;
 725         struct stat st;
 726         int fd = 0;
 727         char *strs;
 728         header_t *header;
 729         libentry_t *libent;
 730         char realcachefile[BUFFER_SIZE];
 731
 732         if (!chroot_realpath(chroot_dir, cachefile, realcachefile))
 733                 err(EXIT_FAILURE, "can't resolve %s in chroot %s (%s)",
 734                     cachefile, chroot_dir, strerror(errno));
 735
 736         if (stat(realcachefile, &st) || (fd = open(realcachefile, O_RDONLY)) < 0)
 737                 err(EXIT_FAILURE, "can't read %s (%s)", cachefile, strerror(errno));
 738
 739         c = mmap(0, st.st_size, PROT_READ, LDSO_CACHE_MMAP_FLAGS, fd, 0);
 740         if (c == MAP_FAILED)
 741                 err(EXIT_FAILURE, "can't map %s (%s)", cachefile, strerror(errno));
 742         close(fd);
 743
 744         if (memcmp(((header_t *) c)->magic, LDSO_CACHE_MAGIC, LDSO_CACHE_MAGIC_LEN))
 745                 err(EXIT_FAILURE, "%s cache corrupt", cachefile);
 746
 747         if (memcmp(((header_t *) c)->version, LDSO_CACHE_VER, LDSO_CACHE_VER_LEN))
 748                 err(EXIT_FAILURE, "wrong cache version - expected %s",
 749                     LDSO_CACHE_VER);
 750
 751         header = (header_t *) c;
 752         libent = (libentry_t *) (c + sizeof(header_t));
 753         strs = (char *)&libent[header->nlibs];
 754
 755         printf("%d libs found in cache `%s' (version %s)\n",
 756                header->nlibs, cachefile, LDSO_CACHE_VER);
 757
 758         for (fd = 0; fd < header->nlibs; fd++) {
 759                 printf("\t%s ", strs + libent[fd].sooffset);
 760                 switch (libent[fd].flags & ~LIB_ELF64) {
 761                 case LIB_DLL:
 762                         printf("(libc4)");
 763                         break;
 764                 case LIB_ELF:
 765                         printf("(ELF%s)", libent[fd].flags & LIB_ELF64 ? "/64" : "");
 766                         break;
 767                 case LIB_ELF_LIBC0:
 768                         printf("(libc0%s)", libent[fd].flags & LIB_ELF64 ? "/64" : "");
 769                         break;
 770                 case LIB_ELF_LIBC5:
 771                 case LIB_ELF_LIBC6:
 772                         printf("(libc%d%s)",
 773                                (libent[fd].flags & ~LIB_ELF64) + 3,
 774                                libent[fd].flags & LIB_ELF64 ? "/64" : "");
 775                         break;
 776                 default:
 777                         printf("(unknown)");
 778                         break;
 779                 }
 780                 printf(" => %s\n", strs + libent[fd].liboffset);
 781         }
 782
 783         munmap(c, st.st_size);
 784 }
 785 #endif
 786
 787 static void usage(void) attribute_noreturn;
 788 static void usage(void)
 789 {
 790         fprintf(stderr,
 791 #ifdef __LDSO_CACHE_SUPPORT__
 792                 "ldconfig - updates symlinks and cache for shared libraries\n\n"
 793                 "Usage: ldconfig [-DvqnNX] [-f conf] [-C cache] [-r root] dir ...\n"
 794                 "       ldconfig -l [-Dv] lib ...\n"
 795                 "       ldconfig -p\n\nOptions:\n"
 796 #else
 797                 "ldconfig - updates symlinks for shared libraries\n\n"
 798                 "Usage: ldconfig [-DvqnX] [-r root] dir ...\n"
 799                 "       ldconfig -l [-Dv] lib ...\n\nOptions:\n"
 800 #endif
 801                 "\t-D:\t\tdebug mode, don't update links\n"
 802                 "\t-v:\t\tverbose mode, print things as we go\n"
 803                 "\t-q:\t\tquiet mode, don't print warnings\n"
 804                 "\t-n:\t\tdon't process standard directories\n"
 805                 "\t-N:\t\tdon't update the library cache\n"
 806                 "\t-X:\t\tdon't update the library links\n"
 807                 "\t-l:\t\tlibrary mode, manually link libraries\n"
 808                 "\t-p:\t\tprint the current library cache\n"
 809 #ifdef __LDSO_CACHE_SUPPORT__
 810                 "\t-f conf :\tuse conf instead of %s\n"
 811                 "\t-C cache:\tuse cache instead of %s\n"
 812 #endif
 813                 "\t-r root :\tfirst, do a chroot to the indicated directory\n"
 814                 "\tdir ... :\tdirectories to process\n"
 815 #ifdef __LDSO_CACHE_SUPPORT__
 816                 "\tlib ... :\tlibraries to link\n\n", LDSO_CONF, LDSO_CACHE
 817 #else
 818                 "\tlib ... :\tlibraries to link\n\n"
 819 #endif
 820             );
 821         exit(EXIT_FAILURE);
 822 }
 823
 824 #define DIR_SEP      ":, \t\n"
 825 int main(int argc, char **argv)
 826 {
 827         int i, c;
 828         int nodefault = 0;
 829         char *cp, *dir, *so;
 830         int libtype, islink;
 831         int printcache = 0;
 832 #ifdef __LDSO_CACHE_SUPPORT__
 833         char *extpath;
 834 #endif
 835
 836         prog = argv[0];
 837         opterr = 0;
 838
 839         while ((c = getopt(argc, argv, "DvqnNXlpf:C:r:")) != EOF)
 840                 switch (c) {
 841                 case 'D':
 842                         debug = 1;      /* debug mode */
 843                         nocache = 1;
 844                         nolinks = 1;
 845                         verbose = 1;
 846                         break;
 847                 case 'v':
 848                         verbose = 1;    /* verbose mode */
 849                         break;
 850                 case 'q':
 851                         if (verbose <= 0)
 852                                 verbose = -1;   /* quiet mode */
 853                         break;
 854                 case 'n':
 855                         nodefault = 1;  /* no default dirs */
 856                         nocache = 1;
 857                         break;
 858                 case 'N':
 859                         nocache = 1;    /* don't build cache */
 860                         break;
 861                 case 'X':
 862                         nolinks = 1;    /* don't update links */
 863                         break;
 864                 case 'l':
 865                         libmode = 1;    /* library mode */
 866                         break;
 867                 case 'p':
 868                         printcache = 1; /* print cache */
 869                         break;
 870                 case 'f':
 871 #ifdef __LDSO_CACHE_SUPPORT__
 872                         conffile = optarg;      /* alternate conf file */
 873 #endif
 874                         break;
 875                 case 'C':
 876 #ifdef __LDSO_CACHE_SUPPORT__
 877                         cachefile = optarg;     /* alternate cache file */
 878 #endif
 879                         break;
 880                 case 'r':
 881                         chroot_dir = optarg;
 882                         break;
 883                 default:
 884                         usage();
 885                         break;
 886
 887                         /* THE REST OF THESE ARE UNDOCUMENTED AND MAY BE REMOVED
 888                            IN FUTURE VERSIONS. */
 889                 }
 890
 891         if (chroot_dir && *chroot_dir) {
 892                 if (chroot(chroot_dir) < 0) {
 893                         if (chdir(chroot_dir) < 0)
 894                                 err(EXIT_FAILURE, "couldn't chroot to %s (%s)", chroot_dir, strerror(errno));
 895                         chroot_dir = ".";
 896                 } else {
 897                         if (chdir("/") < 0)
 898                                 err(EXIT_FAILURE, "couldn't chdir to / (%s)", strerror(errno));
 899                         chroot_dir = NULL;
 900                 }
 901         }
 902
 903         /* allow me to introduce myself, hi, my name is ... */
 904         if (verbose > 0)
 905                 printf("%s: uClibc version\n", argv[0]);
 906
 907         if (printcache) {
 908                 /* print the cache -- don't you trust me? */
 909                 cache_print();
 910                 exit(EXIT_SUCCESS);
 911         } else if (libmode) {
 912                 /* so you want to do things manually, eh? */
 913
 914                 /* ok, if you're so smart, which libraries do we link? */
 915                 for (i = optind; i < argc; i++) {
 916                         /* split into directory and file parts */
 917                         if (!(cp = strrchr(argv[i], '/'))) {
 918                                 dir = ".";      /* no dir, only a filename */
 919                                 cp = argv[i];
 920                         } else {
 921                                 if (cp == argv[i])
 922                                         dir = "/";      /* file in root directory */
 923                                 else
 924                                         dir = argv[i];
 925                                 *cp++ = '\0';   /* neither of the above */
 926                         }
 927
 928                         /* we'd better do a little bit of checking */
 929                         if ((so = is_shlib(dir, cp, &libtype, &islink, LIB_ANY)) == NULL)
 930                                 err(EXIT_FAILURE, "%s%s%s is not a shared library",
 931                                     dir, (*dir && strcmp(dir, "/")) ? "/" : "", cp);
 932
 933                         /* so far, so good, maybe he knows what he's doing */
 934                         link_shlib(dir, cp, so);
 935                 }
 936         } else {
 937                 /* the lazy bum want's us to do all the work for him */
 938
 939                 /* don't cache dirs on the command line */
 940                 int nocache_save = nocache;
 941                 nocache = 1;
 942
 943                 /* OK, which directories should we do? */
 944                 for (i = optind; i < argc; i++)
 945                         scan_dir(argv[i]);
 946
 947                 /* restore the desired caching state */
 948                 nocache = nocache_save;
 949
 950                 /* look ma, no defaults */
 951                 if (!nodefault) {
 952                         scan_dir(UCLIBC_RUNTIME_PREFIX "lib");
 953                         scan_dir(UCLIBC_RUNTIME_PREFIX "usr/lib");
 954 #ifndef __LDSO_CACHE_SUPPORT__
 955                         scan_dir(UCLIBC_RUNTIME_PREFIX "usr/X11R6/lib");
 956 #else
 957                         /* I guess the defaults aren't good enough */
 958                         if ((extpath = get_extpath())) {
 959                                 for (cp = strtok(extpath, DIR_SEP); cp; cp = strtok(NULL, DIR_SEP)) {
 960                                         /* strip trailing slashes */
 961                                         int len = strlen(cp);
 962                                         if (len)
 963                                                 while (cp[--len] == '/' && len)
 964                                                         cp[len] = 0;
 965                                         /* we do the redundancy check only if cache usage is enabled */
 966                                         if (strcmp(UCLIBC_RUNTIME_PREFIX "lib", cp) == 0
 967                                             || strcmp(UCLIBC_RUNTIME_PREFIX "usr/lib", cp) == 0) {
 968                                                 if (verbose >= 0)
 969                                                         warnx("You should remove `%s' from `%s'", cp, LDSO_CONF);
 970                                                 continue;
 971                                         }
 972                                         scan_dir(cp);
 973                                 }
 974                                 free(extpath);
 975                         }
 976 #endif
 977                 }
 978
 979                 if (!nocache)
 980                         cache_write();
 981         }
 982
 983         exit(EXIT_SUCCESS);
 984 }