1#include <sys/stat.h> 2#include <fcntl.h> 3#include <errno.h> 4#include "syscall.h" 5 6void __procfdname(char *, unsigned); 7 8int fchmodat(int fd, const char *path, mode_t mode, int flag) 9{ 10 if (!flag) return syscall(SYS_fchmodat, fd, path, mode, flag); 11 12 if (flag != AT_SYMLINK_NOFOLLOW) 13 return __syscall_ret(-EINVAL); 14 15 struct stat st; 16 int ret, fd2; 17 char proc[15+3*sizeof(int)]; 18 19 if ((ret = __syscall(SYS_fstatat, fd, path, &st, flag))) 20 return __syscall_ret(ret); 21 if (S_ISLNK(st.st_mode)) 22 return __syscall_ret(-EOPNOTSUPP); 23 24 if ((fd2 = __syscall(SYS_openat, fd, path, O_RDONLY|O_PATH|O_NOFOLLOW|O_NOCTTY|O_CLOEXEC)) < 0) { 25 if (fd2 == -ELOOP) 26 return __syscall_ret(-EOPNOTSUPP); 27 return __syscall_ret(fd2); 28 } 29 30 __procfdname(proc, fd2); 31 ret = __syscall(SYS_fstatat, AT_FDCWD, proc, &st, 0); 32 if (!ret) { 33 if (S_ISLNK(st.st_mode)) ret = -EOPNOTSUPP; 34 else ret = __syscall(SYS_fchmodat, AT_FDCWD, proc, mode); 35 } 36 37 __syscall(SYS_close, fd2); 38 return __syscall_ret(ret); 39} 40