init/initramfs.c

   1 #define __KERNEL_SYSCALLS__
   2 #include <linux/init.h>
   3 #include <linux/fs.h>
   4 #include <linux/slab.h>
   5 #include <linux/types.h>
   6 #include <linux/fcntl.h>
   7 #include <linux/unistd.h>
   8 #include <linux/delay.h>
   9 #include <linux/string.h>
  10 #include <linux/vmalloc.h>
  11
  12 #ifdef CONFIG_ACPI_INITRD
  13                 unsigned char *dsdt_start;
  14 #endif
  15
  16 static __initdata char *message;
  17
  18 static void __init error(char *x)
  19 {
  20         if (!message)
  21                 message = x;
  22 }
  23
  24 static void __init *malloc(int size)
  25 {
  26         return kmalloc(size, GFP_KERNEL);
  27 }
  28
  29 static void __init free(void *where)
  30 {
  31         kfree(where);
  32 }
  33
  34 asmlinkage long sys_mkdir(char *name, int mode);
  35 asmlinkage long sys_mknod(char *name, int mode, unsigned dev);
  36 asmlinkage long sys_symlink(char *old, char *new);
  37 asmlinkage long sys_link(char *old, char *new);
  38 asmlinkage long sys_write(int fd, const char *buf, size_t size);
  39 asmlinkage long sys_chown(char *name, uid_t uid, gid_t gid);
  40 asmlinkage long sys_lchown(char *name, uid_t uid, gid_t gid);
  41 asmlinkage long sys_fchown(int fd, uid_t uid, gid_t gid);
  42 asmlinkage long sys_chmod(char *name, mode_t mode);
  43 asmlinkage long sys_fchmod(int fd, mode_t mode);
  44
  45 /* link hash */
  46
  47 static struct hash {
  48         int ino, minor, major;
  49         struct hash *next;
  50         char *name;
  51 } *head[32];
  52
  53 static inline int hash(int major, int minor, int ino)
  54 {
  55         unsigned long tmp = ino + minor + (major << 3);
  56         tmp += tmp >> 5;
  57         return tmp & 31;
  58 }
  59
  60 static char __init *find_link(int major, int minor, int ino, char *name)
  61 {
  62         struct hash **p, *q;
  63         for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
  64                 if ((*p)->ino != ino)
  65                         continue;
  66                 if ((*p)->minor != minor)
  67                         continue;
  68                 if ((*p)->major != major)
  69                         continue;
  70                 return (*p)->name;
  71         }
  72         q = (struct hash *)malloc(sizeof(struct hash));
  73         if (!q)
  74                 panic("can't allocate link hash entry");
  75         q->ino = ino;
  76         q->minor = minor;
  77         q->major = major;
  78         q->name = name;
  79         q->next = NULL;
  80         *p = q;
  81         return NULL;
  82 }
  83
  84 static void __init free_hash(void)
  85 {
  86         struct hash **p, *q;
  87         for (p = head; p < head + 32; p++) {
  88                 while (*p) {
  89                         q = *p;
  90                         *p = q->next;
  91                         free(q);
  92                 }
  93         }
  94 }
  95
  96 /* cpio header parsing */
  97
  98 static __initdata unsigned long ino, major, minor, nlink;
  99 static __initdata mode_t mode;
 100 static __initdata unsigned long body_len, name_len;
 101 static __initdata uid_t uid;
 102 static __initdata gid_t gid;
 103 static __initdata unsigned rdev;
 104
 105 static void __init parse_header(char *s)
 106 {
 107         unsigned long parsed[12];
 108         char buf[9];
 109         int i;
 110
 111         buf[8] = '\0';
 112         for (i = 0, s += 6; i < 12; i++, s += 8) {
 113                 memcpy(buf, s, 8);
 114                 parsed[i] = simple_strtoul(buf, NULL, 16);
 115         }
 116         ino = parsed[0];
 117         mode = parsed[1];
 118         uid = parsed[2];
 119         gid = parsed[3];
 120         nlink = parsed[4];
 121         body_len = parsed[6];
 122         major = parsed[7];
 123         minor = parsed[8];
 124         rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
 125         name_len = parsed[11];
 126 }
 127
 128 /* FSM */
 129
 130 static __initdata enum state {
 131         Start,
 132         Collect,
 133         GotHeader,
 134         SkipIt,
 135         GotName,
 136         CopyFile,
 137         GotSymlink,
 138         Reset
 139 } state, next_state;
 140
 141 static __initdata char *victim;
 142 static __initdata unsigned count;
 143 static __initdata loff_t this_header, next_header;
 144
 145 static __initdata int dry_run;
 146
 147 static inline void eat(unsigned n)
 148 {
 149         victim += n;
 150         this_header += n;
 151         count -= n;
 152 }
 153
 154 #define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
 155
 156 static __initdata char *collected;
 157 static __initdata int remains;
 158 static __initdata char *collect;
 159
 160 static void __init read_into(char *buf, unsigned size, enum state next)
 161 {
 162         if (count >= size) {
 163                 collected = victim;
 164                 eat(size);
 165                 state = next;
 166         } else {
 167                 collect = collected = buf;
 168                 remains = size;
 169                 next_state = next;
 170                 state = Collect;
 171         }
 172 }
 173
 174 static __initdata char *header_buf, *symlink_buf, *name_buf;
 175
 176 static int __init do_start(void)
 177 {
 178         read_into(header_buf, 110, GotHeader);
 179         return 0;
 180 }
 181
 182 static int __init do_collect(void)
 183 {
 184         unsigned n = remains;
 185         if (count < n)
 186                 n = count;
 187         memcpy(collect, victim, n);
 188         eat(n);
 189         collect += n;
 190         if (remains -= n)
 191                 return 1;
 192         state = next_state;
 193         return 0;
 194 }
 195
 196 static int __init do_header(void)
 197 {
 198         if (memcmp(collected, "070701", 6)) {
 199                 error("no cpio magic");
 200                 return 1;
 201         }
 202         parse_header(collected);
 203         next_header = this_header + N_ALIGN(name_len) + body_len;
 204         next_header = (next_header + 3) & ~3;
 205         if (dry_run) {
 206                 read_into(name_buf, N_ALIGN(name_len), GotName);
 207                 return 0;
 208         }
 209         state = SkipIt;
 210         if (name_len <= 0 || name_len > PATH_MAX)
 211                 return 0;
 212         if (S_ISLNK(mode)) {
 213                 if (body_len > PATH_MAX)
 214                         return 0;
 215                 collect = collected = symlink_buf;
 216                 remains = N_ALIGN(name_len) + body_len;
 217                 next_state = GotSymlink;
 218                 state = Collect;
 219                 return 0;
 220         }
 221         if (S_ISREG(mode) || !body_len)
 222                 read_into(name_buf, N_ALIGN(name_len), GotName);
 223         return 0;
 224 }
 225
 226 static int __init do_skip(void)
 227 {
 228         if (this_header + count <= next_header) {
 229                 eat(count);
 230                 return 1;
 231         } else {
 232                 eat(next_header - this_header);
 233                 state = next_state;
 234                 return 0;
 235         }
 236 }
 237
 238 static int __init do_reset(void)
 239 {
 240         while(count && *victim == '\0')
 241                 eat(1);
 242         if (count && (this_header & 3))
 243                 error("broken padding");
 244         return 1;
 245 }
 246
 247 static int __init maybe_link(void)
 248 {
 249         if (nlink >= 2) {
 250                 char *old = find_link(major, minor, ino, collected);
 251                 if (old)
 252                         return (sys_link(old, collected) < 0) ? -1 : 1;
 253         }
 254         return 0;
 255 }
 256
 257 static __initdata int wfd;
 258
 259 static int __init do_name(void)
 260 {
 261         state = SkipIt;
 262         next_state = Start;
 263         if (strcmp(collected, "TRAILER!!!") == 0) {
 264                 free_hash();
 265                 next_state = Reset;
 266                 return 0;
 267         }
 268         if (dry_run)
 269                 return 0;
 270         if (S_ISREG(mode)) {
 271                 if (maybe_link() >= 0) {
 272                         wfd = sys_open(collected, O_WRONLY|O_CREAT, mode);
 273                         if (wfd >= 0) {
 274                                 sys_fchown(wfd, uid, gid);
 275                                 sys_fchmod(wfd, mode);
 276                                 state = CopyFile;
 277                         }
 278                 }
 279         } else if (S_ISDIR(mode)) {
 280                 sys_mkdir(collected, mode);
 281                 sys_chown(collected, uid, gid);
 282                 sys_chmod(collected, mode);
 283         } else if (S_ISBLK(mode) || S_ISCHR(mode) ||
 284                    S_ISFIFO(mode) || S_ISSOCK(mode)) {
 285                 if (maybe_link() == 0) {
 286                         sys_mknod(collected, mode, rdev);
 287                         sys_chown(collected, uid, gid);
 288                         sys_chmod(collected, mode);
 289                 }
 290         }
 291         return 0;
 292 }
 293
 294 static int __init do_copy(void)
 295 {
 296         if (count >= body_len) {
 297                 sys_write(wfd, victim, body_len);
 298                 sys_close(wfd);
 299                 eat(body_len);
 300                 state = SkipIt;
 301                 return 0;
 302         } else {
 303                 sys_write(wfd, victim, count);
 304                 body_len -= count;
 305                 eat(count);
 306                 return 1;
 307         }
 308 }
 309
 310 static int __init do_symlink(void)
 311 {
 312         collected[N_ALIGN(name_len) + body_len] = '\0';
 313         sys_symlink(collected + N_ALIGN(name_len), collected);
 314         sys_lchown(collected, uid, gid);
 315         state = SkipIt;
 316         next_state = Start;
 317         return 0;
 318 }
 319
 320 static __initdata int (*actions[])(void) = {
 321         [Start]         = do_start,
 322         [Collect]       = do_collect,
 323         [GotHeader]     = do_header,
 324         [SkipIt]        = do_skip,
 325         [GotName]       = do_name,
 326         [CopyFile]      = do_copy,
 327         [GotSymlink]    = do_symlink,
 328         [Reset]         = do_reset,
 329 };
 330
 331 static int __init write_buffer(char *buf, unsigned len)
 332 {
 333         count = len;
 334         victim = buf;
 335
 336         while (!actions[state]())
 337                 ;
 338         return len - count;
 339 }
 340
 341 static void __init flush_buffer(char *buf, unsigned len)
 342 {
 343         int written;
 344         if (message)
 345                 return;
 346         while ((written = write_buffer(buf, len)) < len && !message) {
 347                 char c = buf[written];
 348                 if (c == '0') {
 349                         buf += written;
 350                         len -= written;
 351                         state = Start;
 352                 } else
 353                         error("junk in compressed archive");
 354         }
 355 }
 356
 357 /*
 358  * gzip declarations
 359  */
 360
 361 #define OF(args)  args
 362
 363 #ifndef memzero
 364 #define memzero(s, n)     memset ((s), 0, (n))
 365 #endif
 366
 367 typedef unsigned char  uch;
 368 typedef unsigned short ush;
 369 typedef unsigned long  ulg;
 370
 371 #define WSIZE 0x8000    /* window size--must be a power of two, and */
 372                         /*  at least 32K for zip's deflate method */
 373
 374 static uch *inbuf;
 375 static uch *window;
 376
 377 static unsigned insize;  /* valid bytes in inbuf */
 378 static unsigned inptr;   /* index of next byte to be processed in inbuf */
 379 static unsigned outcnt;  /* bytes in output buffer */
 380 static long bytes_out;
 381
 382 #define get_byte()  (inptr < insize ? inbuf[inptr++] : -1)
 383
 384 /* Diagnostic functions (stubbed out) */
 385 #define Assert(cond,msg)
 386 #define Trace(x)
 387 #define Tracev(x)
 388 #define Tracevv(x)
 389 #define Tracec(c,x)
 390 #define Tracecv(c,x)
 391
 392 #define STATIC static
 393
 394 static void flush_window(void);
 395 static void error(char *m);
 396 static void gzip_mark(void **);
 397 static void gzip_release(void **);
 398
 399 #include "../lib/inflate.c"
 400
 401 static void __init gzip_mark(void **ptr)
 402 {
 403 }
 404
 405 static void __init gzip_release(void **ptr)
 406 {
 407 }
 408
 409 /* ===========================================================================
 410  * Write the output window window[0..outcnt-1] and update crc and bytes_out.
 411  * (Used for the decompressed data only.)
 412  */
 413 static void __init flush_window(void)
 414 {
 415         ulg c = crc;         /* temporary variable */
 416         unsigned n;
 417         uch *in, ch;
 418
 419         flush_buffer(window, outcnt);
 420         in = window;
 421         for (n = 0; n < outcnt; n++) {
 422                 ch = *in++;
 423                 c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8);
 424         }
 425         crc = c;
 426         bytes_out += (ulg)outcnt;
 427         outcnt = 0;
 428 }
 429
 430 char * __init unpack_to_rootfs(char *buf, unsigned len, int check_only)
 431 {
 432         int written;
 433         dry_run = check_only;
 434         header_buf = malloc(110);
 435         symlink_buf = malloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1);
 436         name_buf = malloc(N_ALIGN(PATH_MAX));
 437         window = malloc(WSIZE);
 438         if (!window || !header_buf || !symlink_buf || !name_buf)
 439                 panic("can't allocate buffers");
 440         state = Start;
 441         this_header = 0;
 442         message = NULL;
 443         while (!message && len) {
 444                 loff_t saved_offset = this_header;
 445                 if (*buf == '0' && !(this_header & 3)) {
 446                         state = Start;
 447                         written = write_buffer(buf, len);
 448                         buf += written;
 449                         len -= written;
 450                         continue;
 451                 }
 452                 if (!*buf) {
 453                         buf++;
 454                         len--;
 455                         this_header++;
 456                         continue;
 457                 }
 458                 this_header = 0;
 459                 insize = len;
 460                 inbuf = buf;
 461                 inptr = 0;
 462                 outcnt = 0;             /* bytes in output buffer */
 463                 bytes_out = 0;
 464                 crc = (ulg)0xffffffffL; /* shift register contents */
 465                 makecrc();
 466                 if (gunzip())
 467                         message = "ungzip failed";
 468                 if (state != Reset)
 469                         error("junk in gzipped archive");
 470                 this_header = saved_offset + inptr;
 471                 buf += inptr;
 472                 len -= inptr;
 473         }
 474         free(window);
 475         free(name_buf);
 476         free(symlink_buf);
 477         free(header_buf);
 478         return message;
 479 }
 480
 481 extern char __initramfs_start, __initramfs_end;
 482 #ifdef CONFIG_BLK_DEV_INITRD
 483 #include <linux/initrd.h>
 484 #endif
 485
 486 void __init populate_rootfs(void)
 487 {
 488         char *err = unpack_to_rootfs(&__initramfs_start,
 489                          &__initramfs_end - &__initramfs_start, 0);
 490         if (err)
 491                 panic(err);
 492 #ifdef CONFIG_BLK_DEV_INITRD
 493         if (initrd_start) {
 494                 int fd;
 495
 496
 497                 printk(KERN_INFO "checking if image is initramfs...");
 498                 err = unpack_to_rootfs((char *)initrd_start,
 499                                initrd_end - initrd_start, 1);
 500                 if (!err) {
 501                         printk(" it is\n");
 502                         unpack_to_rootfs((char *)initrd_start,
 503                                  initrd_end - initrd_start, 0);
 504                         free_initrd_mem(initrd_start, initrd_end);
 505                         return;
 506                 }
 507                 printk("it isn't (%s); looks like an initrd\n", err);
 508
 509 #ifdef CONFIG_ACPI_INITRD
 510                 unsigned char start_signature[] = "INITRDDSDT123DSDT123";
 511                 unsigned char end_signature[] =   "INITRDDSDT321DSDT321";
 512                 unsigned char *data;
 513                 unsigned char *dsdt_start_tmp = NULL;
 514                 unsigned char *initrd_end_tmp = NULL;
 515                 dsdt_start = NULL;
 516
 517                 printk(KERN_INFO "Looking for DSDT in initrd ...");
 518                  //* don't scan above end, do not modify initrd borders *//
 519                 initrd_end_tmp=(unsigned char*)initrd_end-sizeof(end_signature);
 520
 521                 // searching for start signature in initrd
 522                 for (data=(unsigned char*)initrd_start;
 523                         data < (unsigned char*)initrd_end_tmp ; ++data) {
 524
 525                         if (!memcmp(data, start_signature,
 526                                 sizeof(start_signature)-1)) {
 527                                 printk(KERN_INFO " found (at offset %u in initrd)!\n",
 528                                         data+sizeof(start_signature)-
 529                                         (unsigned char*)initrd_start);
 530                                 dsdt_start_tmp = data+sizeof(start_signature);
 531                                 break;
 532                         }
 533                 }
 534                 // check if head of dsdt is valid
 535                 if (dsdt_start_tmp != NULL && !memcmp(dsdt_start_tmp, "DSDT", 4)) {
 536                         // searching for end signature in initrd
 537                         for (data += sizeof(end_signature);
 538                                 data <= (unsigned char*)initrd_end; data++){
 539                                 if (!memcmp(data, end_signature,
 540                                         sizeof(end_signature)-1)){
 541                                         break;
 542                                 }
 543                         }
 544                         printk (KERN_INFO "size of dsdt: %u!\n", data-dsdt_start_tmp);
 545                         // DSDT could be about 10-200kb, maybe more?
 546                         // could kmalloc be used ?
 547                         // am I allowed to use vmalloc ?
 548                         dsdt_start = vmalloc(data-dsdt_start_tmp+1);
 549                         memcpy(dsdt_start, dsdt_start_tmp, data-dsdt_start_tmp);
 550                         printk(KERN_INFO "%d bytes allocated and copied for DSDT", data-dsdt_start_tmp);
 551                 }
 552                 else{
 553                         printk(KERN_INFO "No customized DSDT found in initrd!\n");
 554                 }
 555 #endif
 556
 557                 fd = sys_open("/initrd.image", O_WRONLY|O_CREAT, 700);
 558                 if (fd >= 0) {
 559                         sys_write(fd, (char *)initrd_start,
 560                                         initrd_end - initrd_start);
 561                         sys_close(fd);
 562                         free_initrd_mem(initrd_start, initrd_end);
 563                 }
 564         }
 565 #endif
 566 }