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