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