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         sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 108                "%08X%08X%08X%08X%08X%08X%08X",
 109                 "070701",               /* magic */
 110                 ino++,                  /* ino */
 111                 S_IFLNK | mode,         /* mode */
 112                 (long) uid,             /* uid */
 113                 (long) gid,             /* gid */
 114                 1,                      /* nlink */
 115                 (long) mtime,           /* mtime */
 116                 (unsigned)strlen(target)+1, /* filesize */
 117                 3,                      /* major */
 118                 1,                      /* minor */
 119                 0,                      /* rmajor */
 120                 0,                      /* rminor */
 121                 (unsigned)strlen(name) + 1,/* namesize */
 122                 0);                     /* chksum */
 123         push_hdr(s);
 124         push_string(name);
 125         push_pad();
 126         push_string(target);
 127         push_pad();
 128         return 0;
 129 }
 130
 131 static int cpio_mkslink_line(const char *line)
 132 {
 133         char name[PATH_MAX + 1];
 134         char target[PATH_MAX + 1];
 135         unsigned int mode;
 136         int uid;
 137         int gid;
 138         int rc = -1;
 139
 140         if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
 141                 fprintf(stderr, "Unrecognized dir format '%s'", line);
 142                 goto fail;
 143         }
 144         rc = cpio_mkslink(name, target, mode, uid, gid);
 145  fail:
 146         return rc;
 147 }
 148
 149 static int cpio_mkgeneric(const char *name, unsigned int mode,
 150                        uid_t uid, gid_t gid)
 151 {
 152         char s[256];
 153         time_t mtime = time(NULL);
 154
 155         sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 156                "%08X%08X%08X%08X%08X%08X%08X",
 157                 "070701",               /* magic */
 158                 ino++,                  /* ino */
 159                 mode,                   /* mode */
 160                 (long) uid,             /* uid */
 161                 (long) gid,             /* gid */
 162                 2,                      /* nlink */
 163                 (long) mtime,           /* mtime */
 164                 0,                      /* filesize */
 165                 3,                      /* major */
 166                 1,                      /* minor */
 167                 0,                      /* rmajor */
 168                 0,                      /* rminor */
 169                 (unsigned)strlen(name) + 1,/* namesize */
 170                 0);                     /* chksum */
 171         push_hdr(s);
 172         push_rest(name);
 173         return 0;
 174 }
 175
 176 enum generic_types {
 177         GT_DIR,
 178         GT_PIPE,
 179         GT_SOCK
 180 };
 181
 182 struct generic_type {
 183         const char *type;
 184         mode_t mode;
 185 };
 186
 187 static struct generic_type generic_type_table[] = {
 188         [GT_DIR] = {
 189                 .type = "dir",
 190                 .mode = S_IFDIR
 191         },
 192         [GT_PIPE] = {
 193                 .type = "pipe",
 194                 .mode = S_IFIFO
 195         },
 196         [GT_SOCK] = {
 197                 .type = "sock",
 198                 .mode = S_IFSOCK
 199         }
 200 };
 201
 202 static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
 203 {
 204         char name[PATH_MAX + 1];
 205         unsigned int mode;
 206         int uid;
 207         int gid;
 208         int rc = -1;
 209
 210         if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
 211                 fprintf(stderr, "Unrecognized %s format '%s'",
 212                         line, generic_type_table[gt].type);
 213                 goto fail;
 214         }
 215         mode |= generic_type_table[gt].mode;
 216         rc = cpio_mkgeneric(name, mode, uid, gid);
 217  fail:
 218         return rc;
 219 }
 220
 221 static int cpio_mkdir_line(const char *line)
 222 {
 223         return cpio_mkgeneric_line(line, GT_DIR);
 224 }
 225
 226 static int cpio_mkpipe_line(const char *line)
 227 {
 228         return cpio_mkgeneric_line(line, GT_PIPE);
 229 }
 230
 231 static int cpio_mksock_line(const char *line)
 232 {
 233         return cpio_mkgeneric_line(line, GT_SOCK);
 234 }
 235
 236 static int cpio_mknod(const char *name, unsigned int mode,
 237                        uid_t uid, gid_t gid, char dev_type,
 238                        unsigned int maj, unsigned int min)
 239 {
 240         char s[256];
 241         time_t mtime = time(NULL);
 242
 243         if (dev_type == 'b')
 244                 mode |= S_IFBLK;
 245         else
 246                 mode |= S_IFCHR;
 247
 248         sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 249                "%08X%08X%08X%08X%08X%08X%08X",
 250                 "070701",               /* magic */
 251                 ino++,                  /* ino */
 252                 mode,                   /* mode */
 253                 (long) uid,             /* uid */
 254                 (long) gid,             /* gid */
 255                 1,                      /* nlink */
 256                 (long) mtime,           /* mtime */
 257                 0,                      /* filesize */
 258                 3,                      /* major */
 259                 1,                      /* minor */
 260                 maj,                    /* rmajor */
 261                 min,                    /* rminor */
 262                 (unsigned)strlen(name) + 1,/* namesize */
 263                 0);                     /* chksum */
 264         push_hdr(s);
 265         push_rest(name);
 266         return 0;
 267 }
 268
 269 static int cpio_mknod_line(const char *line)
 270 {
 271         char name[PATH_MAX + 1];
 272         unsigned int mode;
 273         int uid;
 274         int gid;
 275         char dev_type;
 276         unsigned int maj;
 277         unsigned int min;
 278         int rc = -1;
 279
 280         if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
 281                          name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
 282                 fprintf(stderr, "Unrecognized nod format '%s'", line);
 283                 goto fail;
 284         }
 285         rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
 286  fail:
 287         return rc;
 288 }
 289
 290 static int cpio_mkfile(const char *name, const char *location,
 291                         unsigned int mode, uid_t uid, gid_t gid,
 292                         unsigned int nlinks)
 293 {
 294         char s[256];
 295         char *filebuf = NULL;
 296         struct stat buf;
 297         long size;
 298         int file = -1;
 299         int retval;
 300         int rc = -1;
 301         int namesize;
 302         int i;
 303
 304         mode |= S_IFREG;
 305
 306         retval = stat (location, &buf);
 307         if (retval) {
 308                 fprintf (stderr, "File %s could not be located\n", location);
 309                 goto error;
 310         }
 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         filebuf = malloc(buf.st_size);
 319         if (!filebuf) {
 320                 fprintf (stderr, "out of memory\n");
 321                 goto error;
 322         }
 323
 324         retval = read (file, filebuf, buf.st_size);
 325         if (retval < 0) {
 326                 fprintf (stderr, "Can not read %s file\n", location);
 327                 goto error;
 328         }
 329
 330         size = 0;
 331         for (i = 1; i <= nlinks; i++) {
 332                 /* data goes on last link */
 333                 if (i == nlinks) size = buf.st_size;
 334
 335                 namesize = strlen(name) + 1;
 336                 sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
 337                        "%08lX%08X%08X%08X%08X%08X%08X",
 338                         "070701",               /* magic */
 339                         ino,                    /* ino */
 340                         mode,                   /* mode */
 341                         (long) uid,             /* uid */
 342                         (long) gid,             /* gid */
 343                         nlinks,                 /* nlink */
 344                         (long) buf.st_mtime,    /* mtime */
 345                         size,                   /* filesize */
 346                         3,                      /* major */
 347                         1,                      /* minor */
 348                         0,                      /* rmajor */
 349                         0,                      /* rminor */
 350                         namesize,               /* namesize */
 351                         0);                     /* chksum */
 352                 push_hdr(s);
 353                 push_string(name);
 354                 push_pad();
 355
 356                 if (size) {
 357                         if (fwrite(filebuf, size, 1, stdout) != 1) {
 358                                 fprintf(stderr, "writing filebuf failed\n");
 359                                 goto error;
 360                         }
 361                         offset += size;
 362                         push_pad();
 363                 }
 364
 365                 name += namesize;
 366         }
 367         ino++;
 368         rc = 0;
 369
 370 error:
 371         if (filebuf) free(filebuf);
 372         if (file >= 0) close(file);
 373         return rc;
 374 }
 375
 376 static char *cpio_replace_env(char *new_location)
 377 {
 378        char expanded[PATH_MAX + 1];
 379        char env_var[PATH_MAX + 1];
 380        char *start;
 381        char *end;
 382
 383        for (start = NULL; (start = strstr(new_location, "${")); ) {
 384                end = strchr(start, '}');
 385                if (start < end) {
 386                        *env_var = *expanded = '\0';
 387                        strncat(env_var, start + 2, end - start - 2);
 388                        strncat(expanded, new_location, start - new_location);
 389                        strncat(expanded, getenv(env_var), PATH_MAX);
 390                        strncat(expanded, end + 1, PATH_MAX);
 391                        strncpy(new_location, expanded, PATH_MAX);
 392                } else
 393                        break;
 394        }
 395
 396        return new_location;
 397 }
 398
 399
 400 static int cpio_mkfile_line(const char *line)
 401 {
 402         char name[PATH_MAX + 1];
 403         char *dname = NULL; /* malloc'ed buffer for hard links */
 404         char location[PATH_MAX + 1];
 405         unsigned int mode;
 406         int uid;
 407         int gid;
 408         int nlinks = 1;
 409         int end = 0, dname_len = 0;
 410         int rc = -1;
 411
 412         if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
 413                                 "s %o %d %d %n",
 414                                 name, location, &mode, &uid, &gid, &end)) {
 415                 fprintf(stderr, "Unrecognized file format '%s'", line);
 416                 goto fail;
 417         }
 418         if (end && isgraph(line[end])) {
 419                 int len;
 420                 int nend;
 421
 422                 dname = malloc(strlen(line));
 423                 if (!dname) {
 424                         fprintf (stderr, "out of memory (%d)\n", dname_len);
 425                         goto fail;
 426                 }
 427
 428                 dname_len = strlen(name) + 1;
 429                 memcpy(dname, name, dname_len);
 430
 431                 do {
 432                         nend = 0;
 433                         if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
 434                                         name, &nend) < 1)
 435                                 break;
 436                         len = strlen(name) + 1;
 437                         memcpy(dname + dname_len, name, len);
 438                         dname_len += len;
 439                         nlinks++;
 440                         end += nend;
 441                 } while (isgraph(line[end]));
 442         } else {
 443                 dname = name;
 444         }
 445         rc = cpio_mkfile(dname, cpio_replace_env(location),
 446                          mode, uid, gid, nlinks);
 447  fail:
 448         if (dname_len) free(dname);
 449         return rc;
 450 }
 451
 452 static void usage(const char *prog)
 453 {
 454         fprintf(stderr, "Usage:\n"
 455                 "\t%s <cpio_list>\n"
 456                 "\n"
 457                 "<cpio_list> is a file containing newline separated entries that\n"
 458                 "describe the files to be included in the initramfs archive:\n"
 459                 "\n"
 460                 "# a comment\n"
 461                 "file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
 462                 "dir <name> <mode> <uid> <gid>\n"
 463                 "nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
 464                 "slink <name> <target> <mode> <uid> <gid>\n"
 465                 "pipe <name> <mode> <uid> <gid>\n"
 466                 "sock <name> <mode> <uid> <gid>\n"
 467                 "\n"
 468                 "<name>       name of the file/dir/nod/etc in the archive\n"
 469                 "<location>   location of the file in the current filesystem\n"
 470                 "             expands shell variables quoted with ${}\n"
 471                 "<target>     link target\n"
 472                 "<mode>       mode/permissions of the file\n"
 473                 "<uid>        user id (0=root)\n"
 474                 "<gid>        group id (0=root)\n"
 475                 "<dev_type>   device type (b=block, c=character)\n"
 476                 "<maj>        major number of nod\n"
 477                 "<min>        minor number of nod\n"
 478                 "<hard links> space separated list of other links to file\n"
 479                 "\n"
 480                 "example:\n"
 481                 "# A simple initramfs\n"
 482                 "dir /dev 0755 0 0\n"
 483                 "nod /dev/console 0600 0 0 c 5 1\n"
 484                 "dir /root 0700 0 0\n"
 485                 "dir /sbin 0755 0 0\n"
 486                 "file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n",
 487                 prog);
 488 }
 489
 490 struct file_handler file_handler_table[] = {
 491         {
 492                 .type    = "file",
 493                 .handler = cpio_mkfile_line,
 494         }, {
 495                 .type    = "nod",
 496                 .handler = cpio_mknod_line,
 497         }, {
 498                 .type    = "dir",
 499                 .handler = cpio_mkdir_line,
 500         }, {
 501                 .type    = "slink",
 502                 .handler = cpio_mkslink_line,
 503         }, {
 504                 .type    = "pipe",
 505                 .handler = cpio_mkpipe_line,
 506         }, {
 507                 .type    = "sock",
 508                 .handler = cpio_mksock_line,
 509         }, {
 510                 .type    = NULL,
 511                 .handler = NULL,
 512         }
 513 };
 514
 515 #define LINE_SIZE (2 * PATH_MAX + 50)
 516
 517 int main (int argc, char *argv[])
 518 {
 519         FILE *cpio_list;
 520         char line[LINE_SIZE];
 521         char *args, *type;
 522         int ec = 0;
 523         int line_nr = 0;
 524
 525         if (2 != argc) {
 526                 usage(argv[0]);
 527                 exit(1);
 528         }
 529
 530         if (!strcmp(argv[1], "-"))
 531                 cpio_list = stdin;
 532         else if (! (cpio_list = fopen(argv[1], "r"))) {
 533                 fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
 534                         argv[1], strerror(errno));
 535                 usage(argv[0]);
 536                 exit(1);
 537         }
 538
 539         while (fgets(line, LINE_SIZE, cpio_list)) {
 540                 int type_idx;
 541                 size_t slen = strlen(line);
 542
 543                 line_nr++;
 544
 545                 if ('#' == *line) {
 546                         /* comment - skip to next line */
 547                         continue;
 548                 }
 549
 550                 if (! (type = strtok(line, " \t"))) {
 551                         fprintf(stderr,
 552                                 "ERROR: incorrect format, could not locate file type line %d: '%s'\n",
 553                                 line_nr, line);
 554                         ec = -1;
 555                         break;
 556                 }
 557
 558                 if ('\n' == *type) {
 559                         /* a blank line */
 560                         continue;
 561                 }
 562
 563                 if (slen == strlen(type)) {
 564                         /* must be an empty line */
 565                         continue;
 566                 }
 567
 568                 if (! (args = strtok(NULL, "\n"))) {
 569                         fprintf(stderr,
 570                                 "ERROR: incorrect format, newline required line %d: '%s'\n",
 571                                 line_nr, line);
 572                         ec = -1;
 573                 }
 574
 575                 for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
 576                         int rc;
 577                         if (! strcmp(line, file_handler_table[type_idx].type)) {
 578                                 if ((rc = file_handler_table[type_idx].handler(args))) {
 579                                         ec = rc;
 580                                         fprintf(stderr, " line %d\n", line_nr);
 581                                 }
 582                                 break;
 583                         }
 584                 }
 585
 586                 if (NULL == file_handler_table[type_idx].type) {
 587                         fprintf(stderr, "unknown file type line %d: '%s'\n",
 588                                 line_nr, line);
 589                 }
 590         }
 591         if (ec == 0)
 592                 cpio_trailer();
 593
 594         exit(ec);
 595 }