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