usr/gen_init_cpio.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <sys/types.h>
   4 #include <sys/stat.h>
   5 #include <string.h>
   6 #include <unistd.h>
   7 #include <time.h>
   8 #include <fcntl.h>
   9 #include <errno.h>
  10 #include <ctype.h>
  11 #include <limits.h>
  12
  13 /*
  14  * Original work by Jeff Garzik
  15  *
  16  * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
  17  * Hard link support by Luciano Rocha
  18  */
  19
  20 #define xstr(s) #s
  21 #define str(s) xstr(s)
  22
  23 static unsigned int offset;
  24 static unsigned int ino = 721;
  25 static time_t default_mtime;
  26
  27 struct file_handler {
  28         const char *type;
  29         int (*handler)(const char *line);
  30 };
  31
  32 static void push_string(const char *name)
  33 {
  34         unsigned int name_len = strlen(name) + 1;
  35
  36         fputs(name, stdout);
  37         putchar(0);
  38         offset += name_len;
  39 }
  40
  41 static void push_pad (void)
  42 {
  43         while (offset & 3) {
  44                 putchar(0);
  45                 offset++;
  46         }
  47 }
  48
  49 static void push_rest(const char *name)
  50 {
  51         unsigned int name_len = strlen(name) + 1;
  52         unsigned int tmp_ofs;
  53
  54         fputs(name, stdout);
  55         putchar(0);
  56         offset += name_len;
  57
  58         tmp_ofs = name_len + 110;
  59         while (tmp_ofs & 3) {
  60                 putchar(0);
  61                 offset++;
  62                 tmp_ofs++;
  63         }
  64 }
  65
  66 static void push_hdr(const char *s)
  67 {
  68         fputs(s, stdout);
  69         offset += 110;
  70 }
  71
  72 static void cpio_trailer(void)
  73 {
  74         char s[256];
  75         const char name[] = "TRAILER!!!";
  76
  77         sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
  78                "%08X%08X%08X%08X%08X%08X%08X",
  79                 "070701",               /* magic */
  80                 0,                      /* ino */
  81                 0,                      /* mode */
  82                 (long) 0,               /* uid */
  83                 (long) 0,               /* gid */
  84                 1,                      /* nlink */
  85                 (long) 0,               /* mtime */
  86                 0,                      /* filesize */
  87                 0,                      /* major */
  88                 0,                      /* minor */
  89                 0,                      /* rmajor */
  90                 0,                      /* rminor */
  91                 (unsigned)strlen(name)+1, /* namesize */
  92                 0);                     /* chksum */
  93         push_hdr(s);
  94         push_rest(name);
  95
  96         while (offset % 512) {
  97                 putchar(0);
  98                 offset++;
  99         }
 100 }
 101
 102 static int cpio_mkslink(const char *name, const char *target,
 103                          unsigned int mode, uid_t uid, gid_t gid)
 104 {
 105         char s[256];
 106
 107         if (name[0] == '/')
 108                 name++;
 109         sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 110                "%08X%08X%08X%08X%08X%08X%08X",
 111                 "070701",               /* magic */
 112                 ino++,                  /* ino */
 113                 S_IFLNK | mode,         /* mode */
 114                 (long) uid,             /* uid */
 115                 (long) gid,             /* gid */
 116                 1,                      /* nlink */
 117                 (long) default_mtime,   /* mtime */
 118                 (unsigned)strlen(target)+1, /* filesize */
 119                 3,                      /* major */
 120                 1,                      /* minor */
 121                 0,                      /* rmajor */
 122                 0,                      /* rminor */
 123                 (unsigned)strlen(name) + 1,/* namesize */
 124                 0);                     /* chksum */
 125         push_hdr(s);
 126         push_string(name);
 127         push_pad();
 128         push_string(target);
 129         push_pad();
 130         return 0;
 131 }
 132
 133 static int cpio_mkslink_line(const char *line)
 134 {
 135         char name[PATH_MAX + 1];
 136         char target[PATH_MAX + 1];
 137         unsigned int mode;
 138         int uid;
 139         int gid;
 140         int rc = -1;
 141
 142         if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
 143                 fprintf(stderr, "Unrecognized dir format '%s'", line);
 144                 goto fail;
 145         }
 146         rc = cpio_mkslink(name, target, mode, uid, gid);
 147  fail:
 148         return rc;
 149 }
 150
 151 static int cpio_mkgeneric(const char *name, unsigned int mode,
 152                        uid_t uid, gid_t gid)
 153 {
 154         char s[256];
 155
 156         if (name[0] == '/')
 157                 name++;
 158         sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 159                "%08X%08X%08X%08X%08X%08X%08X",
 160                 "070701",               /* magic */
 161                 ino++,                  /* ino */
 162                 mode,                   /* mode */
 163                 (long) uid,             /* uid */
 164                 (long) gid,             /* gid */
 165                 2,                      /* nlink */
 166                 (long) default_mtime,   /* mtime */
 167                 0,                      /* filesize */
 168                 3,                      /* major */
 169                 1,                      /* minor */
 170                 0,                      /* rmajor */
 171                 0,                      /* rminor */
 172                 (unsigned)strlen(name) + 1,/* namesize */
 173                 0);                     /* chksum */
 174         push_hdr(s);
 175         push_rest(name);
 176         return 0;
 177 }
 178
 179 enum generic_types {
 180         GT_DIR,
 181         GT_PIPE,
 182         GT_SOCK
 183 };
 184
 185 struct generic_type {
 186         const char *type;
 187         mode_t mode;
 188 };
 189
 190 static struct generic_type generic_type_table[] = {
 191         [GT_DIR] = {
 192                 .type = "dir",
 193                 .mode = S_IFDIR
 194         },
 195         [GT_PIPE] = {
 196                 .type = "pipe",
 197                 .mode = S_IFIFO
 198         },
 199         [GT_SOCK] = {
 200                 .type = "sock",
 201                 .mode = S_IFSOCK
 202         }
 203 };
 204
 205 static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
 206 {
 207         char name[PATH_MAX + 1];
 208         unsigned int mode;
 209         int uid;
 210         int gid;
 211         int rc = -1;
 212
 213         if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
 214                 fprintf(stderr, "Unrecognized %s format '%s'",
 215                         line, generic_type_table[gt].type);
 216                 goto fail;
 217         }
 218         mode |= generic_type_table[gt].mode;
 219         rc = cpio_mkgeneric(name, mode, uid, gid);
 220  fail:
 221         return rc;
 222 }
 223
 224 static int cpio_mkdir_line(const char *line)
 225 {
 226         return cpio_mkgeneric_line(line, GT_DIR);
 227 }
 228
 229 static int cpio_mkpipe_line(const char *line)
 230 {
 231         return cpio_mkgeneric_line(line, GT_PIPE);
 232 }
 233
 234 static int cpio_mksock_line(const char *line)
 235 {
 236         return cpio_mkgeneric_line(line, GT_SOCK);
 237 }
 238
 239 static int cpio_mknod(const char *name, unsigned int mode,
 240                        uid_t uid, gid_t gid, char dev_type,
 241                        unsigned int maj, unsigned int min)
 242 {
 243         char s[256];
 244
 245         if (dev_type == 'b')
 246                 mode |= S_IFBLK;
 247         else
 248                 mode |= S_IFCHR;
 249
 250         if (name[0] == '/')
 251                 name++;
 252         sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 253                "%08X%08X%08X%08X%08X%08X%08X",
 254                 "070701",               /* magic */
 255                 ino++,                  /* ino */
 256                 mode,                   /* mode */
 257                 (long) uid,             /* uid */
 258                 (long) gid,             /* gid */
 259                 1,                      /* nlink */
 260                 (long) default_mtime,   /* mtime */
 261                 0,                      /* filesize */
 262                 3,                      /* major */
 263                 1,                      /* minor */
 264                 maj,                    /* rmajor */
 265                 min,                    /* rminor */
 266                 (unsigned)strlen(name) + 1,/* namesize */
 267                 0);                     /* chksum */
 268         push_hdr(s);
 269         push_rest(name);
 270         return 0;
 271 }
 272
 273 static int cpio_mknod_line(const char *line)
 274 {
 275         char name[PATH_MAX + 1];
 276         unsigned int mode;
 277         int uid;
 278         int gid;
 279         char dev_type;
 280         unsigned int maj;
 281         unsigned int min;
 282         int rc = -1;
 283
 284         if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
 285                          name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
 286                 fprintf(stderr, "Unrecognized nod format '%s'", line);
 287                 goto fail;
 288         }
 289         rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
 290  fail:
 291         return rc;
 292 }
 293
 294 static int cpio_mkfile(const char *name, const char *location,
 295                         unsigned int mode, uid_t uid, gid_t gid,
 296                         unsigned int nlinks)
 297 {
 298         char s[256];
 299         char *filebuf = NULL;
 300         struct stat buf;
 301         long size;
 302         int file = -1;
 303         int retval;
 304         int rc = -1;
 305         int namesize;
 306         unsigned int i;
 307
 308         mode |= S_IFREG;
 309
 310         file = open (location, O_RDONLY);
 311         if (file < 0) {
 312                 fprintf (stderr, "File %s could not be opened for reading\n", location);
 313                 goto error;
 314         }
 315
 316         retval = fstat(file, &buf);
 317         if (retval) {
 318                 fprintf(stderr, "File %s could not be stat()'ed\n", location);
 319                 goto error;
 320         }
 321
 322         filebuf = malloc(buf.st_size);
 323         if (!filebuf) {
 324                 fprintf (stderr, "out of memory\n");
 325                 goto error;
 326         }
 327
 328         retval = read (file, filebuf, buf.st_size);
 329         if (retval < 0) {
 330                 fprintf (stderr, "Can not read %s file\n", location);
 331                 goto error;
 332         }
 333
 334         size = 0;
 335         for (i = 1; i <= nlinks; i++) {
 336                 /* data goes on last link */
 337                 if (i == nlinks) size = buf.st_size;
 338
 339                 if (name[0] == '/')
 340                         name++;
 341                 namesize = strlen(name) + 1;
 342                 sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 343                        "%08lX%08X%08X%08X%08X%08X%08X",
 344                         "070701",               /* magic */
 345                         ino,                    /* ino */
 346                         mode,                   /* mode */
 347                         (long) uid,             /* uid */
 348                         (long) gid,             /* gid */
 349                         nlinks,                 /* nlink */
 350                         (long) buf.st_mtime,    /* mtime */
 351                         size,                   /* filesize */
 352                         3,                      /* major */
 353                         1,                      /* minor */
 354                         0,                      /* rmajor */
 355                         0,                      /* rminor */
 356                         namesize,               /* namesize */
 357                         0);                     /* chksum */
 358                 push_hdr(s);
 359                 push_string(name);
 360                 push_pad();
 361
 362                 if (size) {
 363                         if (fwrite(filebuf, size, 1, stdout) != 1) {
 364                                 fprintf(stderr, "writing filebuf failed\n");
 365                                 goto error;
 366                         }
 367                         offset += size;
 368                         push_pad();
 369                 }
 370
 371                 name += namesize;
 372         }
 373         ino++;
 374         rc = 0;
 375
 376 error:
 377         if (filebuf) free(filebuf);
 378         if (file >= 0) close(file);
 379         return rc;
 380 }
 381
 382 static char *cpio_replace_env(char *new_location)
 383 {
 384         char expanded[PATH_MAX + 1];
 385         char *start, *end, *var;
 386
 387         while ((start = strstr(new_location, "${")) &&
 388                (end = strchr(start + 2, '}'))) {
 389                 *start = *end = 0;
 390                 var = getenv(start + 2);
 391                 snprintf(expanded, sizeof expanded, "%s%s%s",
 392                          new_location, var ? var : "", end + 1);
 393                 strcpy(new_location, expanded);
 394         }
 395
 396         return new_location;
 397 }
 398
 399 static int cpio_mkfile_line(const char *line)
 400 {
 401         char name[PATH_MAX + 1];
 402         char *dname = NULL; /* malloc'ed buffer for hard links */
 403         char location[PATH_MAX + 1];
 404         unsigned int mode;
 405         int uid;
 406         int gid;
 407         int nlinks = 1;
 408         int end = 0, dname_len = 0;
 409         int rc = -1;
 410
 411         if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
 412                                 "s %o %d %d %n",
 413                                 name, location, &mode, &uid, &gid, &end)) {
 414                 fprintf(stderr, "Unrecognized file format '%s'", line);
 415                 goto fail;
 416         }
 417         if (end && isgraph(line[end])) {
 418                 int len;
 419                 int nend;
 420
 421                 dname = malloc(strlen(line));
 422                 if (!dname) {
 423                         fprintf (stderr, "out of memory (%d)\n", dname_len);
 424                         goto fail;
 425                 }
 426
 427                 dname_len = strlen(name) + 1;
 428                 memcpy(dname, name, dname_len);
 429
 430                 do {
 431                         nend = 0;
 432                         if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
 433                                         name, &nend) < 1)
 434                                 break;
 435                         len = strlen(name) + 1;
 436                         memcpy(dname + dname_len, name, len);
 437                         dname_len += len;
 438                         nlinks++;
 439                         end += nend;
 440                 } while (isgraph(line[end]));
 441         } else {
 442                 dname = name;
 443         }
 444         rc = cpio_mkfile(dname, cpio_replace_env(location),
 445                          mode, uid, gid, nlinks);
 446  fail:
 447         if (dname_len) free(dname);
 448         return rc;
 449 }
 450
 451 static void usage(const char *prog)
 452 {
 453         fprintf(stderr, "Usage:\n"
 454                 "\t%s [-t <timestamp>] <cpio_list>\n"
 455                 "\n"
 456                 "<cpio_list> is a file containing newline separated entries that\n"
 457                 "describe the files to be included in the initramfs archive:\n"
 458                 "\n"
 459                 "# a comment\n"
 460                 "file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
 461                 "dir <name> <mode> <uid> <gid>\n"
 462                 "nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
 463                 "slink <name> <target> <mode> <uid> <gid>\n"
 464                 "pipe <name> <mode> <uid> <gid>\n"
 465                 "sock <name> <mode> <uid> <gid>\n"
 466                 "\n"
 467                 "<name>       name of the file/dir/nod/etc in the archive\n"
 468                 "<location>   location of the file in the current filesystem\n"
 469                 "             expands shell variables quoted with ${}\n"
 470                 "<target>     link target\n"
 471                 "<mode>       mode/permissions of the file\n"
 472                 "<uid>        user id (0=root)\n"
 473                 "<gid>        group id (0=root)\n"
 474                 "<dev_type>   device type (b=block, c=character)\n"
 475                 "<maj>        major number of nod\n"
 476                 "<min>        minor number of nod\n"
 477                 "<hard links> space separated list of other links to file\n"
 478                 "\n"
 479                 "example:\n"
 480                 "# A simple initramfs\n"
 481                 "dir /dev 0755 0 0\n"
 482                 "nod /dev/console 0600 0 0 c 5 1\n"
 483                 "dir /root 0700 0 0\n"
 484                 "dir /sbin 0755 0 0\n"
 485                 "file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
 486                 "\n"
 487                 "<timestamp> is time in seconds since Epoch that will be used\n"
 488                 "as mtime for symlinks, special files and directories. The default\n"
 489                 "is to use the current time for these entries.\n",
 490                 prog);
 491 }
 492
 493 struct file_handler file_handler_table[] = {
 494         {
 495                 .type    = "file",
 496                 .handler = cpio_mkfile_line,
 497         }, {
 498                 .type    = "nod",
 499                 .handler = cpio_mknod_line,
 500         }, {
 501                 .type    = "dir",
 502                 .handler = cpio_mkdir_line,
 503         }, {
 504                 .type    = "slink",
 505                 .handler = cpio_mkslink_line,
 506         }, {
 507                 .type    = "pipe",
 508                 .handler = cpio_mkpipe_line,
 509         }, {
 510                 .type    = "sock",
 511                 .handler = cpio_mksock_line,
 512         }, {
 513                 .type    = NULL,
 514                 .handler = NULL,
 515         }
 516 };
 517
 518 #define LINE_SIZE (2 * PATH_MAX + 50)
 519
 520 int main (int argc, char *argv[])
 521 {
 522         FILE *cpio_list;
 523         char line[LINE_SIZE];
 524         char *args, *type;
 525         int ec = 0;
 526         int line_nr = 0;
 527         const char *filename;
 528
 529         default_mtime = time(NULL);
 530         while (1) {
 531                 int opt = getopt(argc, argv, "t:h");
 532                 char *invalid;
 533
 534                 if (opt == -1)
 535                         break;
 536                 switch (opt) {
 537                 case 't':
 538                         default_mtime = strtol(optarg, &invalid, 10);
 539                         if (!*optarg || *invalid) {
 540                                 fprintf(stderr, "Invalid timestamp: %s\n",
 541                                                 optarg);
 542                                 usage(argv[0]);
 543                                 exit(1);
 544                         }
 545                         break;
 546                 case 'h':
 547                 case '?':
 548                         usage(argv[0]);
 549                         exit(opt == 'h' ? 0 : 1);
 550                 }
 551         }
 552
 553         if (argc - optind != 1) {
 554                 usage(argv[0]);
 555                 exit(1);
 556         }
 557         filename = argv[optind];
 558         if (!strcmp(filename, "-"))
 559                 cpio_list = stdin;
 560         else if (!(cpio_list = fopen(filename, "r"))) {
 561                 fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
 562                         filename, strerror(errno));
 563                 usage(argv[0]);
 564                 exit(1);
 565         }
 566
 567         while (fgets(line, LINE_SIZE, cpio_list)) {
 568                 int type_idx;
 569                 size_t slen = strlen(line);
 570
 571                 line_nr++;
 572
 573                 if ('#' == *line) {
 574                         /* comment - skip to next line */
 575                         continue;
 576                 }
 577
 578                 if (! (type = strtok(line, " \t"))) {
 579                         fprintf(stderr,
 580                                 "ERROR: incorrect format, could not locate file type line %d: '%s'\n",
 581                                 line_nr, line);
 582                         ec = -1;
 583                         break;
 584                 }
 585
 586                 if ('\n' == *type) {
 587                         /* a blank line */
 588                         continue;
 589                 }
 590
 591                 if (slen == strlen(type)) {
 592                         /* must be an empty line */
 593                         continue;
 594                 }
 595
 596                 if (! (args = strtok(NULL, "\n"))) {
 597                         fprintf(stderr,
 598                                 "ERROR: incorrect format, newline required line %d: '%s'\n",
 599                                 line_nr, line);
 600                         ec = -1;
 601                 }
 602
 603                 for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
 604                         int rc;
 605                         if (! strcmp(line, file_handler_table[type_idx].type)) {
 606                                 if ((rc = file_handler_table[type_idx].handler(args))) {
 607                                         ec = rc;
 608                                         fprintf(stderr, " line %d\n", line_nr);
 609                                 }
 610                                 break;
 611                         }
 612                 }
 613
 614                 if (NULL == file_handler_table[type_idx].type) {
 615                         fprintf(stderr, "unknown file type line %d: '%s'\n",
 616                                 line_nr, line);
 617                 }
 618         }
 619         if (ec == 0)
 620                 cpio_trailer();
 621
 622         exit(ec);
 623 }