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 env_var[PATH_MAX + 1];
 386         char *start;
 387         char *end;
 388
 389         for (start = NULL; (start = strstr(new_location, "${")); ) {
 390                 end = strchr(start, '}');
 391                 if (start < end) {
 392                         *env_var = *expanded = '\0';
 393                         strncat(env_var, start + 2, end - start - 2);
 394                         strncat(expanded, new_location, start - new_location);
 395                         strncat(expanded, getenv(env_var),
 396                                 PATH_MAX - strlen(expanded));
 397                         strncat(expanded, end + 1,
 398                                 PATH_MAX - strlen(expanded));
 399                         strncpy(new_location, expanded, PATH_MAX);
 400                         new_location[PATH_MAX] = 0;
 401                 } else
 402                         break;
 403         }
 404
 405         return new_location;
 406 }
 407
 408
 409 static int cpio_mkfile_line(const char *line)
 410 {
 411         char name[PATH_MAX + 1];
 412         char *dname = NULL; /* malloc'ed buffer for hard links */
 413         char location[PATH_MAX + 1];
 414         unsigned int mode;
 415         int uid;
 416         int gid;
 417         int nlinks = 1;
 418         int end = 0, dname_len = 0;
 419         int rc = -1;
 420
 421         if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
 422                                 "s %o %d %d %n",
 423                                 name, location, &mode, &uid, &gid, &end)) {
 424                 fprintf(stderr, "Unrecognized file format '%s'", line);
 425                 goto fail;
 426         }
 427         if (end && isgraph(line[end])) {
 428                 int len;
 429                 int nend;
 430
 431                 dname = malloc(strlen(line));
 432                 if (!dname) {
 433                         fprintf (stderr, "out of memory (%d)\n", dname_len);
 434                         goto fail;
 435                 }
 436
 437                 dname_len = strlen(name) + 1;
 438                 memcpy(dname, name, dname_len);
 439
 440                 do {
 441                         nend = 0;
 442                         if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
 443                                         name, &nend) < 1)
 444                                 break;
 445                         len = strlen(name) + 1;
 446                         memcpy(dname + dname_len, name, len);
 447                         dname_len += len;
 448                         nlinks++;
 449                         end += nend;
 450                 } while (isgraph(line[end]));
 451         } else {
 452                 dname = name;
 453         }
 454         rc = cpio_mkfile(dname, cpio_replace_env(location),
 455                          mode, uid, gid, nlinks);
 456  fail:
 457         if (dname_len) free(dname);
 458         return rc;
 459 }
 460
 461 static void usage(const char *prog)
 462 {
 463         fprintf(stderr, "Usage:\n"
 464                 "\t%s [-t <timestamp>] <cpio_list>\n"
 465                 "\n"
 466                 "<cpio_list> is a file containing newline separated entries that\n"
 467                 "describe the files to be included in the initramfs archive:\n"
 468                 "\n"
 469                 "# a comment\n"
 470                 "file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
 471                 "dir <name> <mode> <uid> <gid>\n"
 472                 "nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
 473                 "slink <name> <target> <mode> <uid> <gid>\n"
 474                 "pipe <name> <mode> <uid> <gid>\n"
 475                 "sock <name> <mode> <uid> <gid>\n"
 476                 "\n"
 477                 "<name>       name of the file/dir/nod/etc in the archive\n"
 478                 "<location>   location of the file in the current filesystem\n"
 479                 "             expands shell variables quoted with ${}\n"
 480                 "<target>     link target\n"
 481                 "<mode>       mode/permissions of the file\n"
 482                 "<uid>        user id (0=root)\n"
 483                 "<gid>        group id (0=root)\n"
 484                 "<dev_type>   device type (b=block, c=character)\n"
 485                 "<maj>        major number of nod\n"
 486                 "<min>        minor number of nod\n"
 487                 "<hard links> space separated list of other links to file\n"
 488                 "\n"
 489                 "example:\n"
 490                 "# A simple initramfs\n"
 491                 "dir /dev 0755 0 0\n"
 492                 "nod /dev/console 0600 0 0 c 5 1\n"
 493                 "dir /root 0700 0 0\n"
 494                 "dir /sbin 0755 0 0\n"
 495                 "file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
 496                 "\n"
 497                 "<timestamp> is time in seconds since Epoch that will be used\n"
 498                 "as mtime for symlinks, special files and directories. The default\n"
 499                 "is to use the current time for these entries.\n",
 500                 prog);
 501 }
 502
 503 struct file_handler file_handler_table[] = {
 504         {
 505                 .type    = "file",
 506                 .handler = cpio_mkfile_line,
 507         }, {
 508                 .type    = "nod",
 509                 .handler = cpio_mknod_line,
 510         }, {
 511                 .type    = "dir",
 512                 .handler = cpio_mkdir_line,
 513         }, {
 514                 .type    = "slink",
 515                 .handler = cpio_mkslink_line,
 516         }, {
 517                 .type    = "pipe",
 518                 .handler = cpio_mkpipe_line,
 519         }, {
 520                 .type    = "sock",
 521                 .handler = cpio_mksock_line,
 522         }, {
 523                 .type    = NULL,
 524                 .handler = NULL,
 525         }
 526 };
 527
 528 #define LINE_SIZE (2 * PATH_MAX + 50)
 529
 530 int main (int argc, char *argv[])
 531 {
 532         FILE *cpio_list;
 533         char line[LINE_SIZE];
 534         char *args, *type;
 535         int ec = 0;
 536         int line_nr = 0;
 537         const char *filename;
 538
 539         default_mtime = time(NULL);
 540         while (1) {
 541                 int opt = getopt(argc, argv, "t:h");
 542                 char *invalid;
 543
 544                 if (opt == -1)
 545                         break;
 546                 switch (opt) {
 547                 case 't':
 548                         default_mtime = strtol(optarg, &invalid, 10);
 549                         if (!*optarg || *invalid) {
 550                                 fprintf(stderr, "Invalid timestamp: %s\n",
 551                                                 optarg);
 552                                 usage(argv[0]);
 553                                 exit(1);
 554                         }
 555                         break;
 556                 case 'h':
 557                 case '?':
 558                         usage(argv[0]);
 559                         exit(opt == 'h' ? 0 : 1);
 560                 }
 561         }
 562
 563         if (argc - optind != 1) {
 564                 usage(argv[0]);
 565                 exit(1);
 566         }
 567         filename = argv[optind];
 568         if (!strcmp(filename, "-"))
 569                 cpio_list = stdin;
 570         else if (!(cpio_list = fopen(filename, "r"))) {
 571                 fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
 572                         filename, strerror(errno));
 573                 usage(argv[0]);
 574                 exit(1);
 575         }
 576
 577         while (fgets(line, LINE_SIZE, cpio_list)) {
 578                 int type_idx;
 579                 size_t slen = strlen(line);
 580
 581                 line_nr++;
 582
 583                 if ('#' == *line) {
 584                         /* comment - skip to next line */
 585                         continue;
 586                 }
 587
 588                 if (! (type = strtok(line, " \t"))) {
 589                         fprintf(stderr,
 590                                 "ERROR: incorrect format, could not locate file type line %d: '%s'\n",
 591                                 line_nr, line);
 592                         ec = -1;
 593                         break;
 594                 }
 595
 596                 if ('\n' == *type) {
 597                         /* a blank line */
 598                         continue;
 599                 }
 600
 601                 if (slen == strlen(type)) {
 602                         /* must be an empty line */
 603                         continue;
 604                 }
 605
 606                 if (! (args = strtok(NULL, "\n"))) {
 607                         fprintf(stderr,
 608                                 "ERROR: incorrect format, newline required line %d: '%s'\n",
 609                                 line_nr, line);
 610                         ec = -1;
 611                 }
 612
 613                 for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
 614                         int rc;
 615                         if (! strcmp(line, file_handler_table[type_idx].type)) {
 616                                 if ((rc = file_handler_table[type_idx].handler(args))) {
 617                                         ec = rc;
 618                                         fprintf(stderr, " line %d\n", line_nr);
 619                                 }
 620                                 break;
 621                         }
 622                 }
 623
 624                 if (NULL == file_handler_table[type_idx].type) {
 625                         fprintf(stderr, "unknown file type line %d: '%s'\n",
 626                                 line_nr, line);
 627                 }
 628         }
 629         if (ec == 0)
 630                 cpio_trailer();
 631
 632         exit(ec);
 633 }