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 *prog = NULL;
  61 int debug = 0;                  /* debug mode */
  62 int verbose = 0;                /* verbose mode */
  63 int libmode = 0;                /* library mode */
  64 int nolinks = 0;                /* don't update links */
  65 int nocache = 0;                /* don't build cache */
  66 void cache_print(void);
  67 void cache_write(void);
  68 void cache_dolib(const char *dir, const char *so, int libtype);
  69 #ifdef __LDSO_CACHE_SUPPORT__
  70 char *conffile = LDSO_CONF;     /* default conf file */
  71 char *cachefile = LDSO_CACHE;   /* default cache file */
  72 #endif
  73 char *chroot_dir = NULL;
  74 int byteswap = 0;
  75
  76 struct needed_tab {
  77         char *soname;
  78         int type;
  79 };
  80
  81 struct needed_tab needed_tab[] = {
  82         {"libc.so.0", LIB_ELF_LIBC0},
  83         {"libm.so.0", LIB_ELF_LIBC0},
  84         {"libdl.so.0", LIB_ELF_LIBC0},
  85         {"libc.so.5", LIB_ELF_LIBC5},
  86         {"libm.so.5", LIB_ELF_LIBC5},
  87         {"libdl.so.1", LIB_ELF_LIBC5},
  88         {"libc.so.6", LIB_ELF_LIBC6},
  89         {"libm.so.6", LIB_ELF_LIBC6},
  90         {"libdl.so.2", LIB_ELF_LIBC6},
  91         {NULL, LIB_ELF}
  92 };
  93
  94 extern char *chroot_realpath(const char *chroot, const char *path,
  95                              char resolved_path[]);
  96
  97 #if defined __UCLIBC_STATIC_LDCONFIG__ || !defined __UCLIBC_HAS_BSD_ERR__
  98 /* These two are used internally -- you shouldn't need to use them */
  99 static void verror_msg(const char *s, va_list p)
 100 {
 101         fflush(stdout);
 102         fprintf(stderr, "%s: ", prog);
 103         vfprintf(stderr, s, p);
 104 }
 105
 106 static void warnx(const char *s, ...)
 107 {
 108         va_list p;
 109
 110         va_start(p, s);
 111         verror_msg(s, p);
 112         va_end(p);
 113         fprintf(stderr, "\n");
 114 }
 115
 116 static attribute_noreturn void err(int errnum, const char *s, ...)
 117 {
 118         va_list p;
 119
 120         va_start(p, s);
 121         verror_msg(s, p);
 122         va_end(p);
 123         fprintf(stderr, "\n");
 124         exit(errnum);
 125 }
 126
 127 static void vperror_msg(const char *s, va_list p)
 128 {
 129         int e = errno;
 130
 131         if (s == 0)
 132                 s = "";
 133         verror_msg(s, p);
 134         if (*s)
 135                 s = ": ";
 136         fprintf(stderr, "%s%s\n", s, strerror(e));
 137 }
 138
 139 static void warn(const char *s, ...)
 140 {
 141         va_list p;
 142
 143         va_start(p, s);
 144         vperror_msg(s, p);
 145         va_end(p);
 146 }
 147 #else
 148 # include <err.h>
 149 #endif
 150
 151 static void *xmalloc(size_t size)
 152 {
 153         void *ptr;
 154         if ((ptr = malloc(size)) == NULL)
 155                 err(EXIT_FAILURE, "out of memory");
 156         return ptr;
 157 }
 158
 159 static char *xstrdup(const char *str)
 160 {
 161         char *ptr;
 162         if ((ptr = strdup(str)) == NULL)
 163                 err(EXIT_FAILURE, "out of memory");
 164         return ptr;
 165 }
 166
 167 #undef __ELF_NATIVE_CLASS
 168 #undef readsonameXX
 169 #define readsonameXX readsoname32
 170 #define __ELF_NATIVE_CLASS 32
 171 #include "readsoname2.c"
 172
 173 #undef __ELF_NATIVE_CLASS
 174 #undef readsonameXX
 175 #define readsonameXX readsoname64
 176 #define __ELF_NATIVE_CLASS 64
 177 #include "readsoname2.c"
 178 static char *readsoname(char *name, FILE *infile, int expected_type,
 179                         int *type, int elfclass)
 180 {
 181         char *res;
 182
 183         if (elfclass == ELFCLASS32)
 184                 res = readsoname32(name, infile, expected_type, type);
 185         else {
 186                 res = readsoname64(name, infile, expected_type, type);
 187 #if 0
 188                 /* relies on multilib support which we dont have ... */
 189                 *type |= LIB_ELF64;
 190 #endif
 191         }
 192
 193         return res;
 194 }
 195
 196 /* If shared library, return a malloced copy of the soname and set the
 197  * type, else return NULL.
 198  *
 199  * expected_type should be either LIB_ANY or one of the following:-
 200  * LIB_DLL
 201  * LIB_ELF
 202  * LIB_ELF_LIBC5
 203  * LIB_ELF_LIBC6
 204  *
 205  * If the lib is ELF and we can not deduce the type the type will
 206  * be set based on expected_type.
 207  *
 208  * If the expected, actual/deduced types missmatch we display a warning
 209  * and use the actual/deduced type.
 210  */
 211 static char *is_shlib(const char *dir, const char *name, int *type,
 212                       int *islink, int expected_type)
 213 {
 214         char *good = NULL;
 215         char *cp, *cp2;
 216         FILE *file;
 217         struct exec exec;
 218         ElfW(Ehdr) *elf_hdr;
 219         struct stat statbuf;
 220         char buff[BUFFER_SIZE];
 221         char real[BUFFER_SIZE];
 222         static int byteswapflag = -1;   /* start with byte-order unknown */
 223
 224         /* see if name is of the form *.so* */
 225         if (name[strlen(name) - 1] != '~' && (cp = strstr(name, ".so"))) {
 226                 /* find the start of the Vminor part, if any */
 227                 if (cp[3] == '.' && (cp2 = strchr(cp + 4, '.')))
 228                         cp = cp2;
 229                 else
 230                         cp = cp + strlen(cp);
 231
 232                 /* construct the full path name */
 233                 sprintf(buff, "%s%s%s", dir, (*dir && strcmp(dir, "/")) ? "/" : "", name);
 234
 235                 /* get real path in case of chroot */
 236                 if (!chroot_realpath(chroot_dir, buff, real))
 237                         warn("can't resolve %s in chroot %s", buff, chroot_dir);
 238
 239                 /* first, make sure it's a regular file */
 240                 if (lstat(real, &statbuf))
 241                         warn("skipping %s", buff);
 242                 else if (!S_ISREG(statbuf.st_mode) && !S_ISLNK(statbuf.st_mode))
 243                         warnx("%s is not a regular file or symlink, skipping", buff);
 244                 else {
 245                         /* is it a regular file or a symlink */
 246                         *islink = S_ISLNK(statbuf.st_mode);
 247
 248                         /* then try opening it */
 249                         if (!(file = fopen(real, "rb")))
 250                                 warn("skipping %s", buff);
 251                         else {
 252                                 /* now make sure it's a shared library */
 253                                 if (fread(&exec, sizeof exec, 1, file) < 1)
 254                                         warnx("can't read header from %s, skipping", buff);
 255                                 else if (N_MAGIC(exec) != ZMAGIC
 256                                  && N_MAGIC(exec) != QMAGIC
 257                                  && N_MAGIC_SWAP(exec) != ZMAGIC
 258                                  && N_MAGIC_SWAP(exec) != QMAGIC) {
 259                                         elf_hdr = (ElfW(Ehdr) *) & exec;
 260                                         if (elf_hdr->e_ident[0] != 0x7f ||
 261                                             strncmp((const char *)elf_hdr->e_ident + 1, "ELF", 3) != 0)
 262                                         {
 263                                                 /* silently ignore linker scripts */
 264                                                 if (strncmp((const char *)&exec, "/* GNU ld", 9) != 0)
 265                                                         warnx("%s is not a shared library, skipping", buff);
 266                                         } else {
 267                                                 /* always call readsoname to update type */
 268                                                 if (expected_type == LIB_DLL) {
 269                                                         warnx("%s is not an a.out library, it's ELF!", buff);
 270                                                         expected_type = LIB_ANY;
 271                                                 }
 272                                                 *type = LIB_ELF;
 273                                                 good = readsoname(buff, file, expected_type, type,
 274                                                                   elf_hdr->e_ident[EI_CLASS]);
 275                                                 if (byteswapflag == -1)
 276                                                         /* byte-order detected */
 277                                                         byteswapflag = byteswap;
 278                                                 if (good == NULL || *islink) {
 279                                                         if (good != NULL)
 280                                                                 free(good);
 281                                                         good = xstrdup(name);
 282                                                 } else {
 283                                                         /* if the soname does not match the filename,
 284                                                            issue a warning, but only in debug mode. */
 285                                                         int len = strlen(good);
 286                                                         if (debug && (strncmp((const char *)good, name, len) != 0
 287                                                             || (name[len] != '\0' && name[len] != '.')))
 288                                                                 warnx("%s has inconsistent soname (%s)", buff, good);
 289                                                 }
 290                                         }
 291                                 } else {
 292                                         /* Determine byte-order */
 293                                         byteswap = (N_MAGIC(exec) == ZMAGIC || N_MAGIC(exec) == QMAGIC) ? 0 : 1;
 294                                         if (byteswapflag == -1)
 295                                                 /* byte-order detected */
 296                                                 byteswapflag = byteswap;
 297
 298                                         if (*islink)
 299                                                 good = xstrdup(name);
 300                                         else {
 301                                                 good = xmalloc(cp - name + 1);
 302                                                 strncpy(good, name, cp - name);
 303                                                 good[cp - name] = '\0';
 304                                         }
 305                                         if (expected_type != LIB_ANY && expected_type != LIB_DLL) {
 306                                                 warnx("%s is not an ELF library, its an a.out DLL!", buff);
 307                                                 expected_type = LIB_ANY;
 308                                         }
 309
 310                                         *type = LIB_DLL;
 311                                 }
 312                                 fclose(file);
 313
 314                                 if (byteswapflag >= 0 && byteswap != byteswapflag) {
 315                                         byteswapflag = -2;
 316                                         warnx("mixed byte-order detected, using host byte-order...");
 317                                 }
 318                                 if (byteswapflag == -2)
 319                                         byteswap = 0;
 320                         }
 321                 }
 322         }
 323
 324         return good;
 325 }
 326
 327 /* update the symlink to new library */
 328 static void link_shlib(const char *dir, const char *file, const char *so)
 329 {
 330         int change = 1;
 331         char libname[BUFFER_SIZE];
 332         char linkname[BUFFER_SIZE];
 333         char reallibname[BUFFER_SIZE];
 334         char reallinkname[BUFFER_SIZE];
 335         struct stat libstat;
 336         struct stat linkstat;
 337
 338         /* construct the full path names */
 339         sprintf(libname, "%s/%s", dir, file);
 340         sprintf(linkname, "%s/%s", dir, so);
 341         if (!chroot_realpath(chroot_dir, libname, reallibname))
 342                 warn("can't resolve %s in chroot %s", libname, chroot_dir);
 343         if (!chroot_realpath(chroot_dir, linkname, reallinkname))
 344                 warn("can't resolve %s in chroot %s", linkname, chroot_dir);
 345
 346         /* see if a link already exists */
 347         if (!stat(reallinkname, &linkstat)) {
 348                 /* now see if it's the one we want */
 349                 if (stat(reallibname, &libstat))
 350                         warn("can't stat %s", libname);
 351                 else if (libstat.st_dev == linkstat.st_dev &&
 352                          libstat.st_ino == linkstat.st_ino)
 353                         change = 0;
 354         }
 355
 356         /* then update the link, if required */
 357         if (change > 0 && !nolinks) {
 358                 if (!lstat(reallinkname, &linkstat)) {
 359                         if (!S_ISLNK(linkstat.st_mode)) {
 360                                 warnx("%s is not a symlink", linkname);
 361                                 change = -1;
 362                         } else if (remove(reallinkname)) {
 363                                 warn("can't unlink %s", linkname);
 364                                 change = -1;
 365                         }
 366                 }
 367                 if (change > 0) {
 368                         if (symlink(file, reallinkname)) {
 369                                 warn("can't link %s to %s", linkname, file);
 370                                 change = -1;
 371                         }
 372                 }
 373         }
 374
 375         /* some people like to know what we're doing */
 376         if (verbose > 0)
 377                 printf("\t%s => %s%s\n", so, file,
 378                        change < 0 ? " (SKIPPED)" :
 379                        (change > 0 ? " (changed)" : ""));
 380
 381         return;
 382 }
 383
 384 /* figure out which library is greater */
 385 static int libcmp(char *p1, char *p2)
 386 {
 387         while (*p1) {
 388                 if (isdigit(*p1) && isdigit(*p2)) {
 389                         /* must compare this numerically */
 390                         int v1, v2;
 391                         v1 = strtoul(p1, &p1, 10);
 392                         v2 = strtoul(p2, &p2, 10);
 393                         if (v1 != v2)
 394                                 return v1 - v2;
 395                 } else if (isdigit(*p1) && !isdigit(*p2))
 396                         return 1;
 397                 else if (!isdigit(*p1) && isdigit(*p2))
 398                         return -1;
 399                 else if (*p1 != *p2)
 400                         return *p1 - *p2;
 401                 else
 402                         p1++, p2++;
 403         }
 404
 405         return *p1 - *p2;
 406 }
 407
 408 struct lib {
 409         char *so;               /* soname of a library */
 410         char *name;             /* name of a library */
 411         int libtype;            /* type of a library */
 412         int islink;             /* is it a symlink */
 413         struct lib *next;       /* next library in list */
 414 };
 415
 416 /* update all shared library links in a directory */
 417 static void scan_dir(const char *rawname)
 418 {
 419         DIR *dir;
 420         const char *name;
 421         struct dirent *ent;
 422         char *so, *path, *path_n;
 423         struct lib *lp, *libs = NULL;
 424         int i, libtype, islink, expected_type = LIB_ANY;
 425         char realname[BUFFER_SIZE];
 426
 427         /* We need a writable copy of this string */
 428         path = strdup(rawname);
 429         if (!path) {
 430                 err(EXIT_FAILURE, "Out of memory!\n");
 431         }
 432         /* Eliminate all double //s */
 433         path_n = path;
 434         while ((path_n = strstr(path_n, "//"))) {
 435                 i = strlen(path_n);
 436                 memmove(path_n, path_n + 1, i - 1);
 437                 *(path_n + i - 1) = '\0';
 438         }
 439         name = path;
 440
 441 #if 0
 442         char *t;
 443         /* Check for an embedded expected type */
 444         t = strrchr(name, '=');
 445         if (t) {
 446                 *t++ = '\0';    /* Skip = char */
 447                 if (strcasecmp(t, "libc4") == 0) {
 448                         expected_type = LIB_DLL;
 449                 } else {
 450                         if (strcasecmp(t, "libc5") == 0) {
 451                                 expected_type = LIB_ELF_LIBC5;
 452                         } else {
 453                                 if (strcasecmp(t, "libc6") == 0) {
 454                                         expected_type = LIB_ELF_LIBC6;
 455                                 } else {
 456                                         if (strcasecmp(t, "libc0") == 0) {
 457                                                 expected_type = LIB_ELF_LIBC0;
 458                                         } else {
 459                                                 warnx("Unknown type field '%s' for dir '%s' - ignored", t, name);
 460                                                 expected_type = LIB_ANY;
 461                                         }
 462                                 }
 463                         }
 464                 }
 465         }
 466 #endif
 467
 468         /* let 'em know what's going on */
 469         if (verbose > 0)
 470                 printf("%s:\n", name);
 471
 472         /* get real path in case of chroot */
 473         if (!chroot_realpath(chroot_dir, name, realname))
 474                 warn("can't resolve %s in chroot %s", name, chroot_dir);
 475
 476         /* if we can't open it, we can't do anything */
 477         if ((dir = opendir(realname)) == NULL) {
 478                 warn("skipping %s", name);
 479                 free(path);
 480                 return;
 481         }
 482
 483         /* yes, we have to look at every single file */
 484         while ((ent = readdir(dir)) != NULL) {
 485                 /* if it's not a shared library, don't bother */
 486                 if ((so = is_shlib(name, ent->d_name, &libtype, &islink, expected_type)) == NULL)
 487                         continue;
 488
 489                 /* have we already seen one with the same so name? */
 490                 for (lp = libs; lp; lp = lp->next) {
 491                         if (strcmp(so, lp->so) == 0) {
 492                                 /* we have, which one do we want to use? */
 493                                 if ((!islink && lp->islink) ||
 494                                     (islink == lp->islink &&
 495                                      libcmp(ent->d_name, lp->name) > 0)) {
 496                                         /* let's use the new one */
 497                                         free(lp->name);
 498                                         lp->name = xstrdup(ent->d_name);
 499                                         lp->libtype = libtype;
 500                                         lp->islink = islink;
 501                                 }
 502                                 break;
 503                         }
 504                 }
 505
 506                 /* congratulations, you're the first one we've seen */
 507                 if (!lp) {
 508                         lp = xmalloc(sizeof *lp);
 509                         lp->so = xstrdup(so);
 510                         lp->name = xstrdup(ent->d_name);
 511                         lp->libtype = libtype;
 512                         lp->islink = islink;
 513                         lp->next = libs;
 514                         libs = lp;
 515                 }
 516
 517                 free(so);
 518         }
 519
 520         /* don't need this any more */
 521         closedir(dir);
 522
 523         /* now we have all the latest libs, update the links */
 524         for (lp = libs; lp; lp = lp->next) {
 525                 if (!lp->islink)
 526                         link_shlib(name, lp->name, lp->so);
 527                 if (!nocache)
 528                         cache_dolib(name, lp->so, lp->libtype);
 529         }
 530
 531         /* always try to clean up after ourselves */
 532         while (libs) {
 533                 lp = libs->next;
 534                 free(libs->so);
 535                 free(libs->name);
 536                 free(libs);
 537                 libs = lp;
 538         }
 539
 540         free(path);
 541         return;
 542 }
 543
 544 #ifndef __LDSO_CACHE_SUPPORT__
 545 void cache_print(void)
 546 {
 547         printf("Library cache disabled\n");
 548 }
 549 void cache_dolib(const char *dir, const char *so, int libtype)
 550 {
 551         return;
 552 }
 553 void cache_write(void)
 554 {
 555         return;
 556 }
 557 #else
 558 /* return the list of system-specific directories */
 559 static char *get_extpath(void)
 560 {
 561         char *res = NULL, *cp;
 562         FILE *file;
 563         struct stat st;
 564         char realconffile[BUFFER_SIZE];
 565
 566         if (!chroot_realpath(chroot_dir, conffile, realconffile))
 567                 return NULL;
 568
 569         if ((file = fopen(realconffile, "r")) != NULL) {
 570                 fstat(fileno(file), &st);
 571                 res = xmalloc(st.st_size + 1);
 572                 (void)fread(res, 1, st.st_size, file);
 573                 fclose(file);
 574                 res[st.st_size] = '\0';
 575
 576                 /* convert comments fo spaces */
 577                 for (cp = res; *cp; /*nada */ ) {
 578                         if (*cp == '#') {
 579                                 do
 580                                         *cp++ = ' ';
 581                                 while (*cp && *cp != '\n');
 582                         } else {
 583                                 cp++;
 584                         }
 585                 }
 586         }
 587
 588         return res;
 589 }
 590
 591 typedef struct liblist {
 592         int flags;
 593         int sooffset;
 594         int liboffset;
 595         char *soname;
 596         char *libname;
 597         struct liblist *next;
 598 } liblist_t;
 599
 600 static header_t magic = { LDSO_CACHE_MAGIC, LDSO_CACHE_VER, 0 };
 601 static liblist_t *lib_head = NULL;
 602
 603 static int liblistcomp(liblist_t *x, liblist_t *y)
 604 {
 605         int res;
 606
 607         if ((res = libcmp(x->soname, y->soname)) == 0) {
 608                 res = libcmp(strrchr(x->libname, '/') + 1,
 609                              strrchr(y->libname, '/') + 1);
 610         }
 611
 612         return res;
 613 }
 614
 615 void cache_dolib(const char *dir, const char *so, int libtype)
 616 {
 617         char fullpath[PATH_MAX];
 618         liblist_t *new_lib, *cur_lib;
 619
 620         magic.nlibs++;
 621         sprintf(fullpath, "%s/%s", dir, so);
 622         new_lib = xmalloc(sizeof(liblist_t));
 623         new_lib->flags = libtype;
 624         new_lib->soname = xstrdup(so);
 625         new_lib->libname = xstrdup(fullpath);
 626
 627         if (lib_head == NULL || liblistcomp(new_lib, lib_head) > 0) {
 628                 new_lib->next = lib_head;
 629                 lib_head = new_lib;
 630         } else {
 631                 for (cur_lib = lib_head; cur_lib->next != NULL &&
 632                      liblistcomp(new_lib, cur_lib->next) <= 0;
 633                      cur_lib = cur_lib->next)
 634                         /* nothing */ ;
 635                 new_lib->next = cur_lib->next;
 636                 cur_lib->next = new_lib;
 637         }
 638 }
 639
 640 void cache_write(void)
 641 {
 642         int cachefd;
 643         int stroffset = 0;
 644         char realcachefile[BUFFER_SIZE];
 645         char tempfile[BUFFER_SIZE];
 646         header_t swap_magic;
 647         header_t *magic_ptr;
 648         libentry_t swap_lib;
 649         libentry_t *lib_ptr;
 650         liblist_t *cur_lib;
 651
 652         if (!magic.nlibs)
 653                 return;
 654
 655         if (!chroot_realpath(chroot_dir, cachefile, realcachefile))
 656                 err(EXIT_FAILURE, "can't resolve %s in chroot %s (%s)",
 657                     cachefile, chroot_dir, strerror(errno));
 658
 659         sprintf(tempfile, "%s~", realcachefile);
 660
 661         if (unlink(tempfile) && errno != ENOENT)
 662                 err(EXIT_FAILURE, "can't unlink %s~ (%s)", cachefile,
 663                     strerror(errno));
 664
 665         if ((cachefd = creat(tempfile, 0644)) < 0)
 666                 err(EXIT_FAILURE, "can't create %s~ (%s)", cachefile,
 667                     strerror(errno));
 668
 669         if (byteswap) {
 670                 swap_magic = magic;
 671                 swap_magic.nlibs = bswap_32(swap_magic.nlibs);
 672                 magic_ptr = &swap_magic;
 673         } else {
 674                 magic_ptr = &magic;
 675         }
 676         if (write(cachefd, magic_ptr, sizeof(header_t)) != sizeof(header_t))
 677                 err(EXIT_FAILURE, "can't write %s~ (%s)", cachefile,
 678                     strerror(errno));
 679
 680         for (cur_lib = lib_head; cur_lib != NULL; cur_lib = cur_lib->next) {
 681                 cur_lib->sooffset = stroffset;
 682                 stroffset += strlen(cur_lib->soname) + 1;
 683                 cur_lib->liboffset = stroffset;
 684                 stroffset += strlen(cur_lib->libname) + 1;
 685                 if (byteswap) {
 686                         swap_lib.flags = bswap_32(cur_lib->flags);
 687                         swap_lib.sooffset = bswap_32(cur_lib->sooffset);
 688                         swap_lib.liboffset = bswap_32(cur_lib->liboffset);
 689                         lib_ptr = &swap_lib;
 690                 } else {
 691                         lib_ptr = (libentry_t *) cur_lib;
 692                 }
 693                 if (write(cachefd, lib_ptr, sizeof(libentry_t)) !=
 694                     sizeof(libentry_t))
 695                         err(EXIT_FAILURE, "can't write %s~ (%s)", cachefile,
 696                             strerror(errno));
 697         }
 698
 699         for (cur_lib = lib_head; cur_lib != NULL; cur_lib = cur_lib->next) {
 700                 if ((size_t)write(cachefd, cur_lib->soname, strlen(cur_lib->soname) + 1)
 701                     != strlen(cur_lib->soname) + 1)
 702                         err(EXIT_FAILURE, "can't write %s~ (%s)", cachefile,
 703                             strerror(errno));
 704                 if ((size_t)write(cachefd, cur_lib->libname, strlen(cur_lib->libname) + 1)
 705                     != strlen(cur_lib->libname) + 1)
 706                         err(EXIT_FAILURE, "can't write %s~ (%s)", cachefile,
 707                             strerror(errno));
 708         }
 709
 710         if (close(cachefd))
 711                 err(EXIT_FAILURE, "can't close %s~ (%s)", cachefile,
 712                     strerror(errno));
 713
 714         if (chmod(tempfile, 0644))
 715                 err(EXIT_FAILURE, "can't chmod %s~ (%s)", cachefile,
 716                     strerror(errno));
 717
 718         if (rename(tempfile, realcachefile))
 719                 err(EXIT_FAILURE, "can't rename %s~ (%s)", cachefile,
 720                     strerror(errno));
 721 }
 722
 723 void cache_print(void)
 724 {
 725         caddr_t c;
 726         struct stat st;
 727         int fd = 0;
 728         char *strs;
 729         header_t *header;
 730         libentry_t *libent;
 731         char realcachefile[BUFFER_SIZE];
 732
 733         if (!chroot_realpath(chroot_dir, cachefile, realcachefile))
 734                 err(EXIT_FAILURE, "can't resolve %s in chroot %s (%s)",
 735                     cachefile, chroot_dir, strerror(errno));
 736
 737         if (stat(realcachefile, &st) || (fd = open(realcachefile, O_RDONLY)) < 0)
 738                 err(EXIT_FAILURE, "can't read %s (%s)", cachefile, strerror(errno));
 739
 740         c = mmap(0, st.st_size, PROT_READ, LDSO_CACHE_MMAP_FLAGS, fd, 0);
 741         if (c == MAP_FAILED)
 742                 err(EXIT_FAILURE, "can't map %s (%s)", cachefile, strerror(errno));
 743         close(fd);
 744
 745         if (memcmp(((header_t *) c)->magic, LDSO_CACHE_MAGIC, LDSO_CACHE_MAGIC_LEN))
 746                 err(EXIT_FAILURE, "%s cache corrupt", cachefile);
 747
 748         if (memcmp(((header_t *) c)->version, LDSO_CACHE_VER, LDSO_CACHE_VER_LEN))
 749                 err(EXIT_FAILURE, "wrong cache version - expected %s",
 750                     LDSO_CACHE_VER);
 751
 752         header = (header_t *) c;
 753         libent = (libentry_t *) (c + sizeof(header_t));
 754         strs = (char *)&libent[header->nlibs];
 755
 756         printf("%d libs found in cache `%s' (version %s)\n",
 757                header->nlibs, cachefile, LDSO_CACHE_VER);
 758
 759         for (fd = 0; fd < header->nlibs; fd++) {
 760                 printf("\t%s ", strs + libent[fd].sooffset);
 761                 switch (libent[fd].flags & ~LIB_ELF64) {
 762                 case LIB_DLL:
 763                         printf("(libc4)");
 764                         break;
 765                 case LIB_ELF:
 766                         printf("(ELF%s)", libent[fd].flags & LIB_ELF64 ? "/64" : "");
 767                         break;
 768                 case LIB_ELF_LIBC0:
 769                         printf("(libc0%s)", libent[fd].flags & LIB_ELF64 ? "/64" : "");
 770                         break;
 771                 case LIB_ELF_LIBC5:
 772                 case LIB_ELF_LIBC6:
 773                         printf("(libc%d%s)",
 774                                (libent[fd].flags & ~LIB_ELF64) + 3,
 775                                libent[fd].flags & LIB_ELF64 ? "/64" : "");
 776                         break;
 777                 default:
 778                         printf("(unknown)");
 779                         break;
 780                 }
 781                 printf(" => %s\n", strs + libent[fd].liboffset);
 782         }
 783
 784         munmap(c, st.st_size);
 785 }
 786 #endif
 787
 788 static attribute_noreturn 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 }