src/stat/fstatat.c

   1 #define _BSD_SOURCE
   2 #include <sys/stat.h>
   3 #include <string.h>
   4 #include <fcntl.h>
   5 #include <errno.h>
   6 #include <stdint.h>
   7 #include <sys/sysmacros.h>
   8 #include "syscall.h"
   9 #include "kstat.h"
  10
  11 struct statx {
  12         uint32_t stx_mask;
  13         uint32_t stx_blksize;
  14         uint64_t stx_attributes;
  15         uint32_t stx_nlink;
  16         uint32_t stx_uid;
  17         uint32_t stx_gid;
  18         uint16_t stx_mode;
  19         uint16_t pad1;
  20         uint64_t stx_ino;
  21         uint64_t stx_size;
  22         uint64_t stx_blocks;
  23         uint64_t stx_attributes_mask;
  24         struct {
  25                 int64_t tv_sec;
  26                 uint32_t tv_nsec;
  27                 int32_t pad;
  28         } stx_atime, stx_btime, stx_ctime, stx_mtime;
  29         uint32_t stx_rdev_major;
  30         uint32_t stx_rdev_minor;
  31         uint32_t stx_dev_major;
  32         uint32_t stx_dev_minor;
  33         uint64_t spare[14];
  34 };
  35
  36 static int fstatat_statx(int fd, const char *restrict path, struct stat *restrict st, int flag)
  37 {
  38         struct statx stx;
  39
  40         int ret = __syscall(SYS_statx, fd, path, flag, 0x7ff, &stx);
  41         if (ret) return ret;
  42
  43         *st = (struct stat){
  44                 .st_dev = makedev(stx.stx_dev_major, stx.stx_dev_minor),
  45                 .st_ino = stx.stx_ino,
  46                 .st_mode = stx.stx_mode,
  47                 .st_nlink = stx.stx_nlink,
  48                 .st_uid = stx.stx_uid,
  49                 .st_gid = stx.stx_gid,
  50                 .st_rdev = makedev(stx.stx_rdev_major, stx.stx_rdev_minor),
  51                 .st_size = stx.stx_size,
  52                 .st_blksize = stx.stx_blksize,
  53                 .st_blocks = stx.stx_blocks,
  54                 .st_atim.tv_sec = stx.stx_atime.tv_sec,
  55                 .st_atim.tv_nsec = stx.stx_atime.tv_nsec,
  56                 .st_mtim.tv_sec = stx.stx_mtime.tv_sec,
  57                 .st_mtim.tv_nsec = stx.stx_mtime.tv_nsec,
  58                 .st_ctim.tv_sec = stx.stx_ctime.tv_sec,
  59                 .st_ctim.tv_nsec = stx.stx_ctime.tv_nsec,
  60         };
  61         return 0;
  62 }
  63
  64 static int fstatat_kstat(int fd, const char *restrict path, struct stat *restrict st, int flag)
  65 {
  66         int ret;
  67         struct kstat kst;
  68
  69         if (flag==AT_EMPTY_PATH && fd>=0 && !*path) {
  70                 ret = __syscall(SYS_fstat, fd, &kst);
  71                 if (ret==-EBADF && __syscall(SYS_fcntl, fd, F_GETFD)>=0) {
  72                         ret = __syscall(SYS_fstatat, fd, path, &kst, flag);
  73                         if (ret==-EINVAL) {
  74                                 char buf[15+3*sizeof(int)];
  75                                 __procfdname(buf, fd);
  76 #ifdef SYS_stat
  77                                 ret = __syscall(SYS_stat, buf, &kst);
  78 #else
  79                                 ret = __syscall(SYS_fstatat, AT_FDCWD, buf, &kst, 0);
  80 #endif
  81                         }
  82                 }
  83         }
  84 #ifdef SYS_lstat
  85         else if ((fd == AT_FDCWD || *path=='/') && flag==AT_SYMLINK_NOFOLLOW)
  86                 ret = __syscall(SYS_lstat, path, &kst);
  87 #endif
  88 #ifdef SYS_stat
  89         else if ((fd == AT_FDCWD || *path=='/') && !flag)
  90                 ret = __syscall(SYS_stat, path, &kst);
  91 #endif
  92         else ret = __syscall(SYS_fstatat, fd, path, &kst, flag);
  93
  94         if (ret) return ret;
  95
  96         *st = (struct stat){
  97                 .st_dev = kst.st_dev,
  98                 .st_ino = kst.st_ino,
  99                 .st_mode = kst.st_mode,
 100                 .st_nlink = kst.st_nlink,
 101                 .st_uid = kst.st_uid,
 102                 .st_gid = kst.st_gid,
 103                 .st_rdev = kst.st_rdev,
 104                 .st_size = kst.st_size,
 105                 .st_blksize = kst.st_blksize,
 106                 .st_blocks = kst.st_blocks,
 107                 .st_atim.tv_sec = kst.st_atime_sec,
 108                 .st_atim.tv_nsec = kst.st_atime_nsec,
 109                 .st_mtim.tv_sec = kst.st_mtime_sec,
 110                 .st_mtim.tv_nsec = kst.st_mtime_nsec,
 111                 .st_ctim.tv_sec = kst.st_ctime_sec,
 112                 .st_ctim.tv_nsec = kst.st_ctime_nsec,
 113         };
 114
 115         return 0;
 116 }
 117
 118 int fstatat(int fd, const char *restrict path, struct stat *restrict st, int flag)
 119 {
 120         int ret;
 121         if (sizeof((struct kstat){0}.st_atime_sec) < sizeof(time_t)) {
 122                 ret = fstatat_statx(fd, path, st, flag);
 123                 if (ret!=-ENOSYS) return __syscall_ret(ret);
 124         }
 125         ret = fstatat_kstat(fd, path, st, flag);
 126         return __syscall_ret(ret);
 127 }
 128
 129 weak_alias(fstatat, fstatat64);