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
25namespace {
26
27void 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
44void 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
67typedef int64_t nacl_abi___ino_t;
68typedef 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
73typedef int64_t nacl_abi__off_t;
74typedef 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
86struct 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
93static const int d_name_shift = offsetof (dirent, d_name) -
94  offsetof (struct nacl_abi_dirent, nacl_abi_d_name);
95
96EXTERN_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
145EXPAND_SYMBOL_LIST_OPERATION(DECLARE_REAL_PTR);
146
147int WRAP(chdir)(const char* pathname) {
148  ERRNO_RTN(ki_chdir(pathname));
149}
150
151int WRAP(close)(int fd) {
152  ERRNO_RTN(ki_close(fd));
153}
154
155int WRAP(dup)(int fd, int* newfd) NOTHROW {
156  *newfd = ki_dup(fd);
157  ERRNO_RTN(*newfd);
158}
159
160int WRAP(dup2)(int fd, int newfd) NOTHROW {
161  ERRNO_RTN(ki_dup2(fd, newfd));
162}
163
164void WRAP(exit)(int status) {
165  ki_exit(status);
166}
167
168int WRAP(fchdir)(int fd) NOTHROW {
169  ERRNO_RTN(ki_fchdir(fd));
170}
171
172int WRAP(fchmod)(int fd, mode_t mode) NOTHROW {
173  ERRNO_RTN(ki_fchmod(fd, mode));
174}
175
176int WRAP(fdatasync)(int fd) NOTHROW {
177  ERRNO_RTN(ki_fdatasync(fd));
178}
179
180int 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
189int WRAP(fsync)(int fd) NOTHROW {
190  ERRNO_RTN(ki_fsync(fd));
191}
192
193int WRAP(getcwd)(char* buf, size_t size) {
194  RTN_ERRNO_IF(ki_getcwd(buf, size) == NULL);
195  return 0;
196}
197
198int 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
227int WRAP(isatty)(int fd, int* result) {
228  *result = ki_isatty(fd);
229  RTN_ERRNO_IF(*result == 0);
230  return 0;
231}
232
233int 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
242int WRAP(mkdir)(const char* pathname, mode_t mode) {
243  ERRNO_RTN(ki_mkdir(pathname, mode));
244}
245
246int 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
260int 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
267int WRAP(open)(const char* pathname, int oflag, mode_t mode, int* newfd) {
268  *newfd = ki_open(pathname, oflag, mode);
269  ERRNO_RTN(*newfd);
270}
271
272int WRAP(open_resource)(const char* file, int* fd) {
273  *fd = ki_open_resource(file);
274  ERRNO_RTN(*fd);
275}
276
277int 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
282int 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
288int 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
294int WRAP(rmdir)(const char* pathname) {
295  ERRNO_RTN(ki_rmdir(pathname));
296}
297
298int 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
303int 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
313int 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
322int WRAP(truncate)(const char* name, int64_t len) {
323  ERRNO_RTN(ki_truncate(name, len));
324}
325
326int 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
332static 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    if (!REAL(func))          \
344      return ENOSYS;          \
345  }
346
347// "real" functions, i.e. the unwrapped original functions.
348
349int _real_close(int fd) {
350  CHECK_REAL(close);
351  return REAL(close)(fd);
352}
353
354void _real_exit(int status) {
355  REAL(exit)(status);
356}
357
358int _real_fchdir(int fd) {
359  CHECK_REAL(fchdir);
360  return REAL(fchdir)(fd);
361}
362
363int _real_fchmod(int fd, mode_t mode) {
364  CHECK_REAL(fchmod);
365  return REAL(fchmod)(fd, mode);
366}
367
368int _real_fdatasync(int fd) {
369  CHECK_REAL(fdatasync);
370  return REAL(fdatasync)(fd);
371}
372
373int _real_fstat(int fd, struct stat* buf) {
374  struct nacl_abi_stat st;
375  CHECK_REAL(fstat);
376
377  int err = REAL(fstat)(fd, (struct stat*)&st);
378  if (err) {
379    errno = err;
380    return -1;
381  }
382
383  nacl_stat_to_stat(&st, buf);
384  return 0;
385}
386
387int _real_fsync(int fd) {
388  CHECK_REAL(fsync);
389  return REAL(fsync)(fd);
390}
391
392int _real_getdents(int fd, void* buf, size_t count, size_t* nread) {
393  // "buf" contains dirent(s); "nacl_buf" contains nacl_abi_dirent(s).
394  // See WRAP(getdents) above.
395  char* nacl_buf = (char*)alloca(count);
396  size_t offset = 0;
397  size_t nacl_offset = 0;
398  size_t nacl_nread;
399  CHECK_REAL(getdents);
400  int err = REAL(getdents)(fd, (dirent*)nacl_buf, count, &nacl_nread);
401  if (err)
402    return err;
403
404  while (nacl_offset < nacl_nread) {
405    dirent* d = (dirent*)((char*)buf + offset);
406    nacl_abi_dirent* nacl_d = (nacl_abi_dirent*)(nacl_buf + nacl_offset);
407    d->d_ino = nacl_d->nacl_abi_d_ino;
408    d->d_off = nacl_d->nacl_abi_d_off;
409    d->d_reclen = nacl_d->nacl_abi_d_reclen + d_name_shift;
410    size_t d_name_len =
411        nacl_d->nacl_abi_d_reclen - offsetof(nacl_abi_dirent, nacl_abi_d_name);
412    memcpy(d->d_name, nacl_d->nacl_abi_d_name, d_name_len);
413
414    offset += d->d_reclen;
415    offset += nacl_d->nacl_abi_d_reclen;
416  }
417
418  *nread = offset;
419  return 0;
420}
421
422int _real_isatty(int fd, int* result) {
423  *result = isatty(fd);
424  return *result ? 0 : -1;
425}
426
427int _real_lseek(int fd, int64_t offset, int whence, int64_t* new_offset) {
428  CHECK_REAL(seek);
429  nacl_abi_off_t nacl_new_offs;
430  int ret = REAL(seek)(fd, offset, whence, &nacl_new_offs);
431  *new_offset = static_cast<off_t>(nacl_new_offs);
432  return ret;
433}
434
435int _real_lstat(const char* path, struct stat* buf) {
436  struct nacl_abi_stat st;
437  CHECK_REAL(lstat);
438
439  int err = REAL(lstat)(path, (struct stat*)&st);
440  if (err) {
441    errno = err;
442    return -1;
443  }
444
445  nacl_stat_to_stat(&st, buf);
446  return 0;
447}
448
449int _real_mkdir(const char* pathname, mode_t mode) {
450  CHECK_REAL(mkdir);
451  return REAL(mkdir)(pathname, mode);
452}
453
454int _real_mmap(void** addr,
455               size_t length,
456               int prot,
457               int flags,
458               int fd,
459               int64_t offset) {
460  CHECK_REAL(mmap);
461  return REAL(mmap)(addr, length, prot, flags, fd, offset);
462}
463
464int _real_munmap(void* addr, size_t length) {
465  CHECK_REAL(munmap);
466  return REAL(munmap)(addr, length);
467}
468
469int _real_open(const char* pathname, int oflag, mode_t mode, int* newfd) {
470  CHECK_REAL(open);
471  return REAL(open)(pathname, oflag, mode, newfd);
472}
473
474int _real_open_resource(const char* file, int* fd) {
475  CHECK_REAL(open_resource);
476  return REAL(open_resource)(file, fd);
477}
478
479int _real_read(int fd, void* buf, size_t count, size_t* nread) {
480  CHECK_REAL(read);
481  return REAL(read)(fd, buf, count, nread);
482}
483
484int _real_readlink(const char* path, char* buf, size_t count, size_t* nread) {
485  CHECK_REAL(readlink);
486  return REAL(readlink)(path, buf, count, nread);
487}
488
489int _real_rmdir(const char* pathname) {
490  CHECK_REAL(rmdir);
491  return REAL(rmdir)(pathname);
492}
493
494int _real_truncate(const char* pathname, int64_t len) {
495  CHECK_REAL(truncate);
496  return REAL(truncate)(pathname, len);
497}
498
499int _real_write(int fd, const void* buf, size_t count, size_t* nwrote) {
500  CHECK_REAL(write);
501  return REAL(write)(fd, buf, count, nwrote);
502}
503
504int _real_getcwd(char* pathname, size_t len) {
505  CHECK_REAL(getcwd);
506  return REAL(getcwd)(pathname, len);
507}
508
509static bool s_wrapped = false;
510
511void kernel_wrap_init() {
512  if (!s_wrapped) {
513    assign_real_pointers();
514    EXPAND_SYMBOL_LIST_OPERATION(USE_WRAP)
515    s_wrapped = true;
516  }
517}
518
519void kernel_wrap_uninit() {
520  if (s_wrapped) {
521    EXPAND_SYMBOL_LIST_OPERATION(USE_REAL)
522    s_wrapped = false;
523  }
524}
525
526EXTERN_C_END
527
528#endif  // defined(__native_client__) && defined(__BIONIC__)
529