native_client_sdk/src/libraries/nacl_io/kernel_wrap_newlib.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 __GLIBC__.
   6 #include "nacl_io/kernel_wrap.h" // IRT_EXT is turned on in this header.
   7
   8 // The entire file is wrapped in this #if. We do this so this .cc file can be
   9 // compiled, even on a non-newlib build.
  10 #if !defined(NACL_IO_IRT_EXT) && defined(__native_client__) && \
  11     !defined(__GLIBC__) && !defined(__BIONIC__)
  12
  13 #include <dirent.h>
  14 #include <errno.h>
  15 #include <irt.h>
  16 #include <irt_dev.h>
  17 #include <sys/mman.h>
  18 #include <sys/stat.h>
  19 #include <sys/time.h>
  20
  21 #include "nacl_io/kernel_intercept.h"
  22 #include "nacl_io/kernel_wrap_real.h"
  23 #include "nacl_io/log.h"
  24
  25 EXTERN_C_BEGIN
  26
  27 // Macro to get the REAL function pointer
  28 #define REAL(name) __nacl_irt_##name##_real
  29
  30 // Macro to get the WRAP function
  31 #define WRAP(name) __nacl_irt_##name##_wrap
  32
  33 // Declare REAL function pointer.
  34 #define DECLARE_REAL_PTR(group, name) \
  35   typeof(__libnacl_irt_##group.name) REAL(name);
  36
  37 // Assign the REAL function pointer.
  38 #define ASSIGN_REAL_PTR(group, name) REAL(name) = __libnacl_irt_##group.name;
  39
  40 // Switch IRT's pointer to the REAL pointer
  41 #define USE_REAL(group, name) \
  42   __libnacl_irt_##group.name = (typeof(REAL(name)))REAL(name);
  43
  44 // Switch the IRT's pointer to the WRAP function
  45 #define USE_WRAP(group, name) \
  46   __libnacl_irt_##group.name = (typeof(REAL(name)))WRAP(name);
  47
  48 extern void __libnacl_irt_dev_filename_init(void);
  49 extern void __libnacl_irt_dev_fdio_init(void);
  50
  51 extern struct nacl_irt_basic __libnacl_irt_basic;
  52 extern struct nacl_irt_fdio __libnacl_irt_fdio;
  53 extern struct nacl_irt_dev_fdio __libnacl_irt_dev_fdio;
  54 extern struct nacl_irt_dev_filename __libnacl_irt_dev_filename;
  55 extern struct nacl_irt_memory __libnacl_irt_memory;
  56
  57 // Create function pointers to the REAL implementation
  58 #define EXPAND_SYMBOL_LIST_OPERATION(OP) \
  59   OP(basic, exit);                       \
  60   OP(fdio, close);                       \
  61   OP(fdio, dup);                         \
  62   OP(fdio, dup2);                        \
  63   OP(fdio, read);                        \
  64   OP(fdio, write);                       \
  65   OP(fdio, seek);                        \
  66   OP(fdio, fstat);                       \
  67   OP(fdio, getdents);                    \
  68   OP(dev_fdio, fchdir);                  \
  69   OP(dev_fdio, fchmod);                  \
  70   OP(dev_fdio, fsync);                   \
  71   OP(dev_fdio, fdatasync);               \
  72   OP(dev_fdio, ftruncate);               \
  73   OP(dev_fdio, isatty);                  \
  74   OP(dev_filename, open);                \
  75   OP(dev_filename, stat);                \
  76   OP(dev_filename, mkdir);               \
  77   OP(dev_filename, rmdir);               \
  78   OP(dev_filename, chdir);               \
  79   OP(dev_filename, getcwd);              \
  80   OP(dev_filename, unlink);              \
  81   OP(dev_filename, truncate);            \
  82   OP(dev_filename, lstat);               \
  83   OP(dev_filename, link);                \
  84   OP(dev_filename, rename);              \
  85   OP(dev_filename, symlink);             \
  86   OP(dev_filename, chmod);               \
  87   OP(dev_filename, access);              \
  88   OP(dev_filename, readlink);            \
  89   OP(dev_filename, utimes);              \
  90   OP(memory, mmap);                      \
  91   OP(memory, munmap);
  92
  93 EXPAND_SYMBOL_LIST_OPERATION(DECLARE_REAL_PTR);
  94
  95 int WRAP(close)(int fd) {
  96   ERRNO_RTN(ki_close(fd));
  97 }
  98
  99 int WRAP(dup)(int fd, int* newfd) {
 100   *newfd = ki_dup(fd);
 101   ERRNO_RTN(*newfd);
 102 }
 103
 104 int WRAP(dup2)(int fd, int newfd) {
 105   newfd = ki_dup2(fd, newfd);
 106   ERRNO_RTN(newfd);
 107 }
 108
 109 void WRAP(exit)(int status) {
 110   ki_exit(status);
 111 }
 112
 113 int WRAP(read)(int fd, void* buf, size_t count, size_t* nread) {
 114   ssize_t signed_nread = ki_read(fd, buf, count);
 115   *nread = static_cast<size_t>(signed_nread);
 116   ERRNO_RTN(signed_nread);
 117 }
 118
 119 int WRAP(write)(int fd, const void* buf, size_t count, size_t* nwrote) {
 120   ssize_t signed_nwrote = ki_write(fd, buf, count);
 121   *nwrote = static_cast<size_t>(signed_nwrote);
 122   ERRNO_RTN(signed_nwrote);
 123 }
 124
 125 int WRAP(seek)(int fd, off_t offset, int whence, off_t* new_offset) {
 126   *new_offset = ki_lseek(fd, offset, whence);
 127   ERRNO_RTN(*new_offset);
 128 }
 129
 130 int WRAP(fstat)(int fd, struct stat* buf) {
 131   ERRNO_RTN(ki_fstat(fd, buf));
 132 }
 133
 134 int WRAP(getdents)(int fd, dirent* buf, size_t count, size_t* nread) {
 135   int rtn = ki_getdents(fd, buf, count);
 136   RTN_ERRNO_IF(rtn < 0);
 137   *nread = rtn;
 138   return 0;
 139 }
 140
 141 int WRAP(fchdir)(int fd) {
 142   ERRNO_RTN(ki_fchdir(fd));
 143 }
 144
 145 int WRAP(fchmod)(int fd, mode_t mode) {
 146   ERRNO_RTN(ki_fchmod(fd, mode));
 147 }
 148
 149 int WRAP(fsync)(int fd) {
 150   ERRNO_RTN(ki_fsync(fd));
 151 }
 152
 153 int WRAP(fdatasync)(int fd) {
 154   ERRNO_RTN(ki_fdatasync(fd));
 155 }
 156
 157 int WRAP(ftruncate)(int fd, off_t length) {
 158   ERRNO_RTN(ki_ftruncate(fd, length));
 159 }
 160
 161 int WRAP(isatty)(int fd, int* result) {
 162   *result = ki_isatty(fd);
 163   RTN_ERRNO_IF(*result == 0);
 164   return 0;
 165 }
 166
 167 int WRAP(mmap)(void** addr,
 168                size_t length,
 169                int prot,
 170                int flags,
 171                int fd,
 172                off_t offset) {
 173   if (flags & MAP_ANONYMOUS)
 174     return REAL(mmap)(addr, length, prot, flags, fd, offset);
 175
 176   *addr = ki_mmap(*addr, length, prot, flags, fd, offset);
 177   RTN_ERRNO_IF(*addr == (void*)-1);
 178   return 0;
 179 }
 180
 181 int WRAP(munmap)(void* addr, size_t length) {
 182   // Always let the real munmap run on the address range. It is not an error if
 183   // there are no mapped pages in that range.
 184   ki_munmap(addr, length);
 185   return REAL(munmap)(addr, length);
 186 }
 187
 188 int WRAP(open)(const char* pathname, int oflag, mode_t mode, int* newfd) {
 189   *newfd = ki_open(pathname, oflag, mode);
 190   ERRNO_RTN(*newfd);
 191 }
 192
 193 int WRAP(stat)(const char* pathname, struct stat* buf) {
 194   ERRNO_RTN(ki_stat(pathname, buf));
 195 }
 196
 197 int WRAP(mkdir)(const char* pathname, mode_t mode) {
 198   ERRNO_RTN(ki_mkdir(pathname, mode));
 199 }
 200
 201 int WRAP(rmdir)(const char* pathname) {
 202   ERRNO_RTN(ki_rmdir(pathname));
 203 }
 204
 205 int WRAP(chdir)(const char* pathname) {
 206   ERRNO_RTN(ki_chdir(pathname));
 207 }
 208
 209 int WRAP(getcwd)(char* pathname, size_t len) {
 210   char* rtn = ki_getcwd(pathname, len);
 211   RTN_ERRNO_IF(NULL == rtn);
 212   return 0;
 213 }
 214
 215 int WRAP(unlink)(const char* pathname) {
 216   ERRNO_RTN(ki_unlink(pathname));
 217 }
 218
 219 int WRAP(truncate)(const char* pathname, off_t length) {
 220   ERRNO_RTN(ki_truncate(pathname, length));
 221 }
 222
 223 int WRAP(lstat)(const char* pathname, struct stat* buf) {
 224   ERRNO_RTN(ki_lstat(pathname, buf));
 225 }
 226
 227 int WRAP(link)(const char* pathname, const char* newpath) {
 228   ERRNO_RTN(ki_link(pathname, newpath));
 229 }
 230
 231 int WRAP(rename)(const char* pathname, const char* newpath) {
 232   ERRNO_RTN(ki_rename(pathname, newpath));
 233 }
 234
 235 int WRAP(symlink)(const char* pathname, const char* newpath) {
 236   ERRNO_RTN(ki_symlink(pathname, newpath));
 237 }
 238
 239 int WRAP(chmod)(const char* pathname, mode_t mode) {
 240   ERRNO_RTN(ki_chmod(pathname, mode));
 241 }
 242
 243 int WRAP(access)(const char* pathname, int amode) {
 244   ERRNO_RTN(ki_access(pathname, amode));
 245 }
 246
 247 int WRAP(readlink)(const char* pathname,
 248                    char* buf,
 249                    size_t count,
 250                    size_t* nread) {
 251   int rtn = ki_readlink(pathname, buf, count);
 252   RTN_ERRNO_IF(rtn < 0);
 253   *nread = rtn;
 254   return 0;
 255 }
 256
 257 int WRAP(utimes)(const char* pathname, const struct timeval times[2]) {
 258   ERRNO_RTN(ki_utimes(pathname, times));
 259 }
 260
 261 static void assign_real_pointers() {
 262   static bool assigned = false;
 263   if (!assigned) {
 264     __libnacl_irt_dev_filename_init();
 265     __libnacl_irt_dev_fdio_init();
 266     EXPAND_SYMBOL_LIST_OPERATION(ASSIGN_REAL_PTR)
 267     assigned = true;
 268   }
 269 }
 270
 271 #define CHECK_REAL(func)    \
 272   if (!REAL(func)) {        \
 273     assign_real_pointers(); \
 274     if (!REAL(func))        \
 275       return ENOSYS;        \
 276   }
 277
 278 // "real" functions, i.e. the unwrapped original functions.
 279
 280 int _real_close(int fd) {
 281   CHECK_REAL(close);
 282   return REAL(close)(fd);
 283 }
 284
 285 void _real_exit(int status) {
 286   if (!REAL(exit))
 287     assign_real_pointers();
 288   REAL(exit)(status);
 289 }
 290
 291 int _real_fstat(int fd, struct stat* buf) {
 292   CHECK_REAL(fstat);
 293   return REAL(fstat)(fd, buf);
 294 }
 295
 296 int _real_isatty(int fd, int* result) {
 297   CHECK_REAL(isatty);
 298   // The real isatty function can be NULL (for example if we are running
 299   // withing chrome).
 300   if (REAL(isatty) == NULL) {
 301     *result = 0;
 302     return ENOTTY;
 303   }
 304   return REAL(isatty)(fd, result);
 305 }
 306
 307 int _real_getdents(int fd, void* nacl_buf, size_t nacl_count, size_t* nread) {
 308   CHECK_REAL(getdents);
 309   return REAL(getdents)(fd, static_cast<dirent*>(nacl_buf), nacl_count, nread);
 310 }
 311
 312 int _real_lseek(int fd, off_t offset, int whence, off_t* new_offset) {
 313   CHECK_REAL(seek);
 314   return REAL(seek)(fd, offset, whence, new_offset);
 315 }
 316
 317 int _real_mkdir(const char* pathname, mode_t mode) {
 318   CHECK_REAL(mkdir);
 319   return REAL(mkdir)(pathname, mode);
 320 }
 321
 322 int _real_mmap(void** addr,
 323                size_t length,
 324                int prot,
 325                int flags,
 326                int fd,
 327                off_t offset) {
 328   CHECK_REAL(mmap);
 329   return REAL(mmap)(addr, length, prot, flags, fd, offset);
 330 }
 331
 332 int _real_munmap(void* addr, size_t length) {
 333   CHECK_REAL(munmap);
 334   return REAL(munmap)(addr, length);
 335 }
 336
 337 int _real_open(const char* pathname, int oflag, mode_t mode, int* newfd) {
 338   CHECK_REAL(open);
 339   return REAL(open)(pathname, oflag, mode, newfd);
 340 }
 341
 342 int _real_open_resource(const char* file, int* fd) {
 343   return ENOSYS;
 344 }
 345
 346 int _real_read(int fd, void* buf, size_t count, size_t* nread) {
 347   CHECK_REAL(read);
 348   return REAL(read)(fd, buf, count, nread);
 349 }
 350
 351 int _real_rmdir(const char* pathname) {
 352   CHECK_REAL(rmdir);
 353   return REAL(rmdir)(pathname);
 354 }
 355
 356 int _real_write(int fd, const void* buf, size_t count, size_t* nwrote) {
 357   CHECK_REAL(write);
 358   return REAL(write)(fd, buf, count, nwrote);
 359 }
 360
 361 int _real_getcwd(char* pathname, size_t len) {
 362   CHECK_REAL(getcwd);
 363   return REAL(getcwd)(pathname, len);
 364 }
 365
 366 static bool s_wrapped = false;
 367
 368 void kernel_wrap_init() {
 369   if (!s_wrapped) {
 370     LOG_TRACE("kernel_wrap_init");
 371     assign_real_pointers();
 372     EXPAND_SYMBOL_LIST_OPERATION(USE_WRAP)
 373     s_wrapped = true;
 374   }
 375 }
 376
 377 void kernel_wrap_uninit() {
 378   if (s_wrapped) {
 379     LOG_TRACE("kernel_wrap_uninit");
 380     EXPAND_SYMBOL_LIST_OPERATION(USE_REAL)
 381     s_wrapped = false;
 382   }
 383 }
 384
 385 EXTERN_C_END
 386
 387 #endif  // defined(__native_client__) && !defined(__GLIBC__) ...