shim_access.c 2.0 KB

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  1. /* -*- mode:c; c-file-style:"k&r"; c-basic-offset: 4; tab-width:4; indent-tabs-mode:nil; mode:auto-fill; fill-column:78; -*- */
  2. /* vim: set ts=4 sw=4 et tw=78 fo=cqt wm=0: */
  3. /* Copyright (C) 2014 Stony Brook University
  4. This file is part of Graphene Library OS.
  5. Graphene Library OS is free software: you can redistribute it and/or
  6. modify it under the terms of the GNU Lesser General Public License
  7. as published by the Free Software Foundation, either version 3 of the
  8. License, or (at your option) any later version.
  9. Graphene Library OS is distributed in the hope that it will be useful,
  10. but WITHOUT ANY WARRANTY; without even the implied warranty of
  11. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12. GNU Lesser General Public License for more details.
  13. You should have received a copy of the GNU Lesser General Public License
  14. along with this program. If not, see <http://www.gnu.org/licenses/>. */
  15. /*
  16. * shim_access.c
  17. *
  18. * Implementation of system call "access" and "faccessat".
  19. */
  20. #include <shim_internal.h>
  21. #include <shim_table.h>
  22. #include <shim_thread.h>
  23. #include <shim_handle.h>
  24. #include <shim_fs.h>
  25. #include <pal.h>
  26. #include <pal_error.h>
  27. #include <linux/fcntl.h>
  28. #include <errno.h>
  29. int shim_do_access (const char * file, mode_t mode)
  30. {
  31. if (!file)
  32. return -EINVAL;
  33. struct shim_dentry * dent = NULL;
  34. int ret = 0;
  35. ret = path_lookupat(NULL, file, LOOKUP_ACCESS|LOOKUP_FOLLOW, &dent, NULL);
  36. if (!ret)
  37. ret = permission(dent, mode, 1);
  38. return ret;
  39. }
  40. int shim_do_faccessat (int dfd, const char * filename, mode_t mode)
  41. {
  42. if (!filename)
  43. return -EINVAL;
  44. if (*filename == '/')
  45. return shim_do_access(filename, mode);
  46. struct shim_dentry * dir = NULL, * dent = NULL;
  47. int ret = 0;
  48. if ((ret = path_startat(dfd, &dir)) < 0)
  49. return ret;
  50. ret = path_lookupat(dir, filename, LOOKUP_ACCESS|LOOKUP_FOLLOW, &dent, NULL);
  51. if (ret < 0)
  52. goto out;
  53. ret = permission(dent, mode, 1);
  54. out:
  55. put_dentry(dir);
  56. return ret;
  57. }