native_client_sdk/src/libraries/nacl_io/kernel_wrap_bionic.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include <sys/types.h>  // Include something that will define __BIONIC__.
   6
   7 #include "nacl_io/kernel_wrap.h" // IRT_EXT is turned on in this header.
   8
   9 // The entire file is wrapped in this #if. We do this so this .cc file can be
  10 // compiled, even on a non-bionic build.
  11
  12 #if !defined(NACL_IO_IRT_EXT) && defined(__native_client__) && \
  13     defined(__BIONIC__)
  14
  15 #include <alloca.h>
  16 #include <assert.h>
  17 #include <dirent.h>
  18 #include <errno.h>
  19 #include <irt_syscalls.h>
  20 #include <string.h>
  21 #include <sys/stat.h>
  22 #include <sys/time.h>
  23
  24 #include "nacl_io/kernel_intercept.h"
  25 #include "nacl_io/kernel_wrap_real.h"
  26 #include "nacl_io/osmman.h"
  27
  28 namespace {
  29
  30 void stat_to_nacl_stat(const struct stat* buf, nacl_abi_stat* nacl_buf) {
  31   memset(nacl_buf, 0, sizeof(struct nacl_abi_stat));
  32   nacl_buf->nacl_abi_st_dev = buf->st_dev;
  33   nacl_buf->nacl_abi_st_ino = buf->st_ino;
  34   nacl_buf->nacl_abi_st_mode = buf->st_mode;
  35   nacl_buf->nacl_abi_st_nlink = buf->st_nlink;
  36   nacl_buf->nacl_abi_st_uid = buf->st_uid;
  37   nacl_buf->nacl_abi_st_gid = buf->st_gid;
  38   nacl_buf->nacl_abi_st_rdev = buf->st_rdev;
  39   nacl_buf->nacl_abi_st_size = buf->st_size;
  40   nacl_buf->nacl_abi_st_blksize = buf->st_blksize;
  41   nacl_buf->nacl_abi_st_blocks = buf->st_blocks;
  42   nacl_buf->nacl_abi_st_atime = buf->st_atime;
  43   nacl_buf->nacl_abi_st_mtime = buf->st_mtime;
  44   nacl_buf->nacl_abi_st_ctime = buf->st_ctime;
  45 }
  46
  47 void nacl_stat_to_stat(const nacl_abi_stat* nacl_buf, struct stat* buf) {
  48   memset(buf, 0, sizeof(struct stat));
  49   buf->st_dev = nacl_buf->nacl_abi_st_dev;
  50   buf->st_ino = nacl_buf->nacl_abi_st_ino;
  51   buf->st_mode = nacl_buf->nacl_abi_st_mode;
  52   buf->st_nlink = nacl_buf->nacl_abi_st_nlink;
  53   buf->st_uid = nacl_buf->nacl_abi_st_uid;
  54   buf->st_gid = nacl_buf->nacl_abi_st_gid;
  55   buf->st_rdev = nacl_buf->nacl_abi_st_rdev;
  56   buf->st_size = nacl_buf->nacl_abi_st_size;
  57   buf->st_blksize = nacl_buf->nacl_abi_st_blksize;
  58   buf->st_blocks = nacl_buf->nacl_abi_st_blocks;
  59   buf->st_atime = nacl_buf->nacl_abi_st_atime;
  60   buf->st_mtime = nacl_buf->nacl_abi_st_mtime;
  61   buf->st_ctime = nacl_buf->nacl_abi_st_ctime;
  62 }
  63
  64 }  // namespace
  65
  66 // From native_client/src/trusted/service_runtime/include/sys/dirent.h
  67
  68 #ifndef nacl_abi___ino_t_defined
  69 #define nacl_abi___ino_t_defined
  70 typedef int64_t nacl_abi___ino_t;
  71 typedef nacl_abi___ino_t nacl_abi_ino_t;
  72 #endif
  73
  74 #ifndef nacl_abi___off_t_defined
  75 #define nacl_abi___off_t_defined
  76 typedef int64_t nacl_abi__off_t;
  77 typedef nacl_abi__off_t nacl_abi_off_t;
  78 #endif
  79
  80 /* We need a way to define the maximum size of a name. */
  81 #ifndef MAXNAMLEN
  82 # ifdef NAME_MAX
  83 #  define MAXNAMLEN NAME_MAX
  84 # else
  85 #  define MAXNAMLEN 255
  86 # endif
  87 #endif
  88
  89 struct nacl_abi_dirent {
  90   nacl_abi_ino_t nacl_abi_d_ino;
  91   nacl_abi_off_t nacl_abi_d_off;
  92   uint16_t       nacl_abi_d_reclen;
  93   char           nacl_abi_d_name[MAXNAMLEN + 1];
  94 };
  95
  96 static const int d_name_shift = offsetof (dirent, d_name) -
  97   offsetof (struct nacl_abi_dirent, nacl_abi_d_name);
  98
  99 EXTERN_C_BEGIN
 100
 101 // Macro to get the REAL function pointer
 102 #define REAL(name) __nacl_irt_##name##_real
 103
 104 // Macro to get the WRAP function
 105 #define WRAP(name) __nacl_irt_##name##_wrap
 106
 107 // Declare REAL function pointer.
 108 #define DECLARE_REAL_PTR(name) typeof(__nacl_irt_##name) REAL(name);
 109
 110 // Assign the REAL function pointer.
 111 #define ASSIGN_REAL_PTR(name) REAL(name) = __nacl_irt_##name;
 112
 113 // Switch IRT's pointer to the REAL pointer
 114 #define USE_REAL(name) __nacl_irt_##name = (typeof(__nacl_irt_##name))REAL(name)
 115
 116 // Switch IRT's pointer to the WRAP function
 117 #define USE_WRAP(name) __nacl_irt_##name = (typeof(__nacl_irt_##name))WRAP(name)
 118
 119 #define EXPAND_SYMBOL_LIST_OPERATION(OP) \
 120   OP(chdir);                             \
 121   OP(close);                             \
 122   OP(dup);                               \
 123   OP(dup2);                              \
 124   OP(exit);                              \
 125   OP(fchdir);                            \
 126   OP(fchmod);                            \
 127   OP(fdatasync);                         \
 128   OP(fstat);                             \
 129   OP(fsync);                             \
 130   OP(getcwd);                            \
 131   OP(getdents);                          \
 132   OP(isatty);                            \
 133   OP(lstat);                             \
 134   OP(mkdir);                             \
 135   OP(mmap);                              \
 136   OP(munmap);                            \
 137   OP(open);                              \
 138   OP(open_resource);                     \
 139   OP(poll);                              \
 140   OP(read);                              \
 141   OP(readlink);                          \
 142   OP(rmdir);                             \
 143   OP(seek);                              \
 144   OP(stat);                              \
 145   OP(truncate);                          \
 146   OP(write);
 147
 148 EXPAND_SYMBOL_LIST_OPERATION(DECLARE_REAL_PTR);
 149
 150 int WRAP(chdir)(const char* pathname) {
 151   ERRNO_RTN(ki_chdir(pathname));
 152 }
 153
 154 int WRAP(close)(int fd) {
 155   ERRNO_RTN(ki_close(fd));
 156 }
 157
 158 int WRAP(dup)(int fd, int* newfd) NOTHROW {
 159   *newfd = ki_dup(fd);
 160   ERRNO_RTN(*newfd);
 161 }
 162
 163 int WRAP(dup2)(int fd, int newfd) NOTHROW {
 164   ERRNO_RTN(ki_dup2(fd, newfd));
 165 }
 166
 167 void WRAP(exit)(int status) {
 168   ki_exit(status);
 169 }
 170
 171 int WRAP(fchdir)(int fd) NOTHROW {
 172   ERRNO_RTN(ki_fchdir(fd));
 173 }
 174
 175 int WRAP(fchmod)(int fd, mode_t mode) NOTHROW {
 176   ERRNO_RTN(ki_fchmod(fd, mode));
 177 }
 178
 179 int WRAP(fdatasync)(int fd) NOTHROW {
 180   ERRNO_RTN(ki_fdatasync(fd));
 181 }
 182
 183 int WRAP(fstat)(int fd, struct nacl_abi_stat* nacl_buf) {
 184   struct stat buf;
 185   memset(&buf, 0, sizeof(struct stat));
 186   int res = ki_fstat(fd, &buf);
 187   RTN_ERRNO_IF(res < 0);
 188   stat_to_nacl_stat(&buf, nacl_buf);
 189   return 0;
 190 }
 191
 192 int WRAP(fsync)(int fd) NOTHROW {
 193   ERRNO_RTN(ki_fsync(fd));
 194 }
 195
 196 int WRAP(getcwd)(char* buf, size_t size) {
 197   RTN_ERRNO_IF(ki_getcwd(buf, size) == NULL);
 198   return 0;
 199 }
 200
 201 int WRAP(getdents)(int fd, dirent* nacl_buf, size_t nacl_count, size_t* nread) {
 202   int nacl_offset = 0;
 203   // "buf" contains dirent(s); "nacl_buf" contains nacl_abi_dirent(s).
 204   // nacl_abi_dirent(s) are smaller than dirent(s), so nacl_count bytes buffer
 205   // is enough
 206   char* buf = (char*)alloca(nacl_count);
 207   int offset = 0;
 208   int count;
 209
 210   count = ki_getdents(fd, buf, nacl_count);
 211   RTN_ERRNO_IF(count < 0);
 212
 213   while (offset < count) {
 214     dirent* d = (dirent*)(buf + offset);
 215     nacl_abi_dirent* nacl_d = (nacl_abi_dirent*)((char*)nacl_buf + nacl_offset);
 216     nacl_d->nacl_abi_d_ino = d->d_ino;
 217     nacl_d->nacl_abi_d_off = d->d_off;
 218     nacl_d->nacl_abi_d_reclen = d->d_reclen - d_name_shift;
 219     size_t d_name_len = d->d_reclen - offsetof(dirent, d_name);
 220     memcpy(nacl_d->nacl_abi_d_name, d->d_name, d_name_len);
 221
 222     offset += d->d_reclen;
 223     nacl_offset += nacl_d->nacl_abi_d_reclen;
 224   }
 225
 226   *nread = nacl_offset;
 227   return 0;
 228 }
 229
 230 int WRAP(isatty)(int fd, int* result) {
 231   *result = ki_isatty(fd);
 232   RTN_ERRNO_IF(*result == 0);
 233   return 0;
 234 }
 235
 236 int WRAP(lstat)(const char* path, struct nacl_abi_stat* nacl_buf) {
 237   struct stat buf;
 238   memset(&buf, 0, sizeof(struct stat));
 239   int res = ki_lstat(path, &buf);
 240   RTN_ERRNO_IF(res < 0);
 241   stat_to_nacl_stat(&buf, nacl_buf);
 242   return 0;
 243 }
 244
 245 int WRAP(mkdir)(const char* pathname, mode_t mode) {
 246   ERRNO_RTN(ki_mkdir(pathname, mode));
 247 }
 248
 249 int WRAP(mmap)(void** addr,
 250                size_t length,
 251                int prot,
 252                int flags,
 253                int fd,
 254                int64_t offset) {
 255   if (flags & MAP_ANONYMOUS)
 256     return REAL(mmap)(addr, length, prot, flags, fd, offset);
 257
 258   *addr = ki_mmap(*addr, length, prot, flags, fd, offset);
 259   RTN_ERRNO_IF(*addr == (void*)-1)
 260   return 0;
 261 }
 262
 263 int WRAP(munmap)(void* addr, size_t length) {
 264   // Always let the real munmap run on the address range. It is not an error if
 265   // there are no mapped pages in that range.
 266   ki_munmap(addr, length);
 267   return REAL(munmap)(addr, length);
 268 }
 269
 270 int WRAP(open)(const char* pathname, int oflag, mode_t mode, int* newfd) {
 271   *newfd = ki_open(pathname, oflag, mode);
 272   ERRNO_RTN(*newfd);
 273 }
 274
 275 int WRAP(open_resource)(const char* file, int* fd) {
 276   *fd = ki_open_resource(file);
 277   ERRNO_RTN(*fd);
 278 }
 279
 280 int WRAP(poll)(struct pollfd* fds, nfds_t nfds, int timeout, int* count) {
 281   *count = ki_poll(fds, nfds, timeout);
 282   ERRNO_RTN(*count);
 283 }
 284
 285 int WRAP(read)(int fd, void* buf, size_t count, size_t* nread) {
 286   ssize_t signed_nread = ki_read(fd, buf, count);
 287   *nread = static_cast<size_t>(signed_nread);
 288   ERRNO_RTN(signed_nread);
 289 }
 290
 291 int WRAP(readlink)(const char* path, char* buf, size_t count, size_t* nread) {
 292   ssize_t signed_nread = ki_readlink(path, buf, count);
 293   *nread = static_cast<size_t>(signed_nread);
 294   ERRNO_RTN(signed_nread);
 295 }
 296
 297 int WRAP(rmdir)(const char* pathname) {
 298   ERRNO_RTN(ki_rmdir(pathname));
 299 }
 300
 301 int WRAP(seek)(int fd, off64_t offset, int whence, int64_t* new_offset) {
 302   *new_offset = ki_lseek(fd, offset, whence);
 303   ERRNO_RTN(*new_offset);
 304 }
 305
 306 int WRAP(select)(int nfds,
 307                  fd_set* readfds,
 308                  fd_set* writefds,
 309                  fd_set* exceptfds,
 310                  struct timeval* timeout,
 311                  int* count) {
 312   *count = ki_select(nfds, readfds, writefds, exceptfds, timeout);
 313   ERRNO_RTN(*count);
 314 }
 315
 316 int WRAP(stat)(const char* pathname, struct nacl_abi_stat* nacl_buf) {
 317   struct stat buf;
 318   memset(&buf, 0, sizeof(struct stat));
 319   int res = ki_stat(pathname, &buf);
 320   RTN_ERRNO_IF(res < 0);
 321   stat_to_nacl_stat(&buf, nacl_buf);
 322   return 0;
 323 }
 324
 325 int WRAP(truncate)(const char* name, int64_t len) {
 326   ERRNO_RTN(ki_truncate(name, len));
 327 }
 328
 329 int WRAP(write)(int fd, const void* buf, size_t count, size_t* nwrote) {
 330   ssize_t signed_nwrote = ki_write(fd, buf, count);
 331   *nwrote = static_cast<size_t>(signed_nwrote);
 332   ERRNO_RTN(signed_nwrote);
 333 }
 334
 335 static void assign_real_pointers() {
 336   static bool assigned = false;
 337   if (!assigned) {
 338     EXPAND_SYMBOL_LIST_OPERATION(ASSIGN_REAL_PTR)
 339     assigned = true;
 340   }
 341 }
 342
 343 #define CHECK_REAL(func) \
 344   if (!REAL(func)) {          \
 345     assign_real_pointers();   \
 346     if (!REAL(func))          \
 347       return ENOSYS;          \
 348   }
 349
 350 // "real" functions, i.e. the unwrapped original functions.
 351
 352 int _real_close(int fd) {
 353   CHECK_REAL(close);
 354   return REAL(close)(fd);
 355 }
 356
 357 void _real_exit(int status) {
 358   REAL(exit)(status);
 359 }
 360
 361 int _real_fchdir(int fd) {
 362   CHECK_REAL(fchdir);
 363   return REAL(fchdir)(fd);
 364 }
 365
 366 int _real_fchmod(int fd, mode_t mode) {
 367   CHECK_REAL(fchmod);
 368   return REAL(fchmod)(fd, mode);
 369 }
 370
 371 int _real_fdatasync(int fd) {
 372   CHECK_REAL(fdatasync);
 373   return REAL(fdatasync)(fd);
 374 }
 375
 376 int _real_fstat(int fd, struct stat* buf) {
 377   struct nacl_abi_stat st;
 378   CHECK_REAL(fstat);
 379
 380   int err = REAL(fstat)(fd, (struct stat*)&st);
 381   if (err) {
 382     errno = err;
 383     return -1;
 384   }
 385
 386   nacl_stat_to_stat(&st, buf);
 387   return 0;
 388 }
 389
 390 int _real_fsync(int fd) {
 391   CHECK_REAL(fsync);
 392   return REAL(fsync)(fd);
 393 }
 394
 395 int _real_getdents(int fd, void* buf, size_t count, size_t* nread) {
 396   // "buf" contains dirent(s); "nacl_buf" contains nacl_abi_dirent(s).
 397   // See WRAP(getdents) above.
 398   char* nacl_buf = (char*)alloca(count);
 399   size_t offset = 0;
 400   size_t nacl_offset = 0;
 401   size_t nacl_nread;
 402   CHECK_REAL(getdents);
 403   int err = REAL(getdents)(fd, (dirent*)nacl_buf, count, &nacl_nread);
 404   if (err)
 405     return err;
 406
 407   while (nacl_offset < nacl_nread) {
 408     dirent* d = (dirent*)((char*)buf + offset);
 409     nacl_abi_dirent* nacl_d = (nacl_abi_dirent*)(nacl_buf + nacl_offset);
 410     d->d_ino = nacl_d->nacl_abi_d_ino;
 411     d->d_off = nacl_d->nacl_abi_d_off;
 412     d->d_reclen = nacl_d->nacl_abi_d_reclen + d_name_shift;
 413     size_t d_name_len =
 414         nacl_d->nacl_abi_d_reclen - offsetof(nacl_abi_dirent, nacl_abi_d_name);
 415     memcpy(d->d_name, nacl_d->nacl_abi_d_name, d_name_len);
 416
 417     offset += d->d_reclen;
 418     offset += nacl_d->nacl_abi_d_reclen;
 419   }
 420
 421   *nread = offset;
 422   return 0;
 423 }
 424
 425 int _real_isatty(int fd, int* result) {
 426   *result = isatty(fd);
 427   return *result ? 0 : -1;
 428 }
 429
 430 int _real_lseek(int fd, int64_t offset, int whence, int64_t* new_offset) {
 431   CHECK_REAL(seek);
 432   nacl_abi_off_t nacl_new_offs;
 433   int ret = REAL(seek)(fd, offset, whence, &nacl_new_offs);
 434   *new_offset = static_cast<off_t>(nacl_new_offs);
 435   return ret;
 436 }
 437
 438 int _real_lstat(const char* path, struct stat* buf) {
 439   struct nacl_abi_stat st;
 440   CHECK_REAL(lstat);
 441
 442   int err = REAL(lstat)(path, (struct stat*)&st);
 443   if (err) {
 444     errno = err;
 445     return -1;
 446   }
 447
 448   nacl_stat_to_stat(&st, buf);
 449   return 0;
 450 }
 451
 452 int _real_mkdir(const char* pathname, mode_t mode) {
 453   CHECK_REAL(mkdir);
 454   return REAL(mkdir)(pathname, mode);
 455 }
 456
 457 int _real_mmap(void** addr,
 458                size_t length,
 459                int prot,
 460                int flags,
 461                int fd,
 462                int64_t offset) {
 463   CHECK_REAL(mmap);
 464   return REAL(mmap)(addr, length, prot, flags, fd, offset);
 465 }
 466
 467 int _real_munmap(void* addr, size_t length) {
 468   CHECK_REAL(munmap);
 469   return REAL(munmap)(addr, length);
 470 }
 471
 472 int _real_open(const char* pathname, int oflag, mode_t mode, int* newfd) {
 473   CHECK_REAL(open);
 474   return REAL(open)(pathname, oflag, mode, newfd);
 475 }
 476
 477 int _real_open_resource(const char* file, int* fd) {
 478   CHECK_REAL(open_resource);
 479   return REAL(open_resource)(file, fd);
 480 }
 481
 482 int _real_read(int fd, void* buf, size_t count, size_t* nread) {
 483   CHECK_REAL(read);
 484   return REAL(read)(fd, buf, count, nread);
 485 }
 486
 487 int _real_readlink(const char* path, char* buf, size_t count, size_t* nread) {
 488   CHECK_REAL(readlink);
 489   return REAL(readlink)(path, buf, count, nread);
 490 }
 491
 492 int _real_rmdir(const char* pathname) {
 493   CHECK_REAL(rmdir);
 494   return REAL(rmdir)(pathname);
 495 }
 496
 497 int _real_truncate(const char* pathname, int64_t len) {
 498   CHECK_REAL(truncate);
 499   return REAL(truncate)(pathname, len);
 500 }
 501
 502 int _real_write(int fd, const void* buf, size_t count, size_t* nwrote) {
 503   CHECK_REAL(write);
 504   return REAL(write)(fd, buf, count, nwrote);
 505 }
 506
 507 int _real_getcwd(char* pathname, size_t len) {
 508   CHECK_REAL(getcwd);
 509   return REAL(getcwd)(pathname, len);
 510 }
 511
 512 static bool s_wrapped = false;
 513
 514 void kernel_wrap_init() {
 515   if (!s_wrapped) {
 516     assign_real_pointers();
 517     EXPAND_SYMBOL_LIST_OPERATION(USE_WRAP)
 518     s_wrapped = true;
 519   }
 520 }
 521
 522 void kernel_wrap_uninit() {
 523   if (s_wrapped) {
 524     EXPAND_SYMBOL_LIST_OPERATION(USE_REAL)
 525     s_wrapped = false;
 526   }
 527 }
 528
 529 EXTERN_C_END
 530
 531 #endif  // defined(__native_client__) && defined(__BIONIC__)