#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include "syscall.h"
void __procfdname(char *, unsigned);
int fchmodat(int fd, const char *path, mode_t mode, int flag)
{
if (!flag) return syscall(SYS_fchmodat, fd, path, mode, flag);
if (flag != AT_SYMLINK_NOFOLLOW)
return __syscall_ret(-EINVAL);
struct stat st;
int ret, fd2;
char proc[15+3*sizeof(int)];
if ((ret = __syscall(SYS_fstatat, fd, path, &st, flag)))
return __syscall_ret(ret);
if (S_ISLNK(st.st_mode))
return __syscall_ret(-EOPNOTSUPP);
if ((fd2 = __syscall(SYS_openat, fd, path, O_RDONLY|O_PATH|O_NOFOLLOW|O_NOCTTY)) < 0) {
if (fd2 == -ELOOP)
return __syscall_ret(-EOPNOTSUPP);
return __syscall_ret(fd2);
}
__procfdname(proc, fd2);
ret = __syscall(SYS_fstatat, AT_FDCWD, proc, &st, 0);
if (!ret && !S_ISLNK(st.st_mode))
ret = __syscall(SYS_fchmodat, AT_FDCWD, proc, mode);
__syscall(SYS_close, fd2);
return __syscall_ret(ret);
}