Merge branch 'faccessat-fchownat' into 'master'

add faccessat(2) and fchownat(2)

See merge request redox-os/relibc!1213

src/platform/linux/mod.rs

@@ -81,14 +81,12 @@ impl Sys {
 }
 
 impl Pal for Sys {
-    #[cfg(any(target_arch = "x86_64", target_arch = "x86"))]
     fn access(path: CStr, mode: c_int) -> Result<()> {
-        e_raw(unsafe { syscall!(ACCESS, path.as_ptr(), mode) }).map(|_| ())
+        Sys::faccessat(AT_FDCWD, path, mode, 0)
     }
 
-    #[cfg(target_arch = "aarch64")]
-    fn access(path: CStr, mode: c_int) -> Result<()> {
-        e_raw(unsafe { syscall!(FACCESSAT, AT_FDCWD, path.as_ptr(), mode, 0) }).map(|_| ())
+    fn faccessat(fd: c_int, path: CStr, amode: c_int, flags: c_int) -> Result<()> {
+        e_raw(unsafe { syscall!(FACCESSAT, fd, path.as_ptr(), amode, flags) }).map(|_| ())
     }
 
     unsafe fn brk(addr: *mut c_void) -> Result<*mut c_void> {
@@ -104,11 +102,14 @@ impl Pal for Sys {
     }
 
     fn chown(path: CStr, owner: uid_t, group: gid_t) -> Result<()> {
-        let flags: c_int = 0;
+        Sys::fchownat(AT_FDCWD, path, owner, group, 0)
+    }
+
+    fn fchownat(fildes: c_int, path: CStr, owner: uid_t, group: gid_t, flags: c_int) -> Result<()> {
         e_raw(unsafe {
             syscall!(
                 FCHOWNAT,
-                AT_FDCWD,
+                fildes,
                 path.as_ptr(),
                 owner as u32,
                 group as u32,

src/platform/pal/mod.rs

@@ -37,6 +37,9 @@ pub trait Pal {
     /// Platform implementation of [`access()`](crate::header::unistd::access) from [`unistd.h`](crate::header::unistd).
     fn access(path: CStr, mode: c_int) -> Result<()>;
 
+    /// Platform implementation of [`faccessat()`](crate::header::unistd::faccessat) from [`unistd.h`](crate::header::unistd).
+    fn faccessat(fd: c_int, path: CStr, amode: c_int, flags: c_int) -> Result<()>;
+
     /// Platform implementation of [`brk()`](crate::header::unistd::brk) from [`unistd.h`](crate::header::unistd).
     unsafe fn brk(addr: *mut c_void) -> Result<*mut c_void>;
 
@@ -95,6 +98,9 @@ pub trait Pal {
     /// Platform implementation of [`fchown()`](crate::header::unistd::fchown) from [`unistd.h`](crate::header::unistd).
     fn fchown(fildes: c_int, owner: uid_t, group: gid_t) -> Result<()>;
 
+    /// Platform implementation of [`fchownat()`](crate::header::unistd::fchownat) from [`unistd.h`](crate::header::unistd).
+    fn fchownat(fildes: c_int, path: CStr, owner: uid_t, group: gid_t, flags: c_int) -> Result<()>;
+
     /// Platform implementation of [`fdatasync()`](crate::header::unistd::fdatasync) from [`unistd.h`](crate::header::unistd).
     fn fdatasync(fildes: c_int) -> Result<()>;
 

src/platform/redox/mod.rs

@@ -32,8 +32,9 @@ use crate::{
             ENOSYS, EOPNOTSUPP, EPERM,
         },
         fcntl::{
-            self, AT_EMPTY_PATH, AT_FDCWD, AT_REMOVEDIR, AT_SYMLINK_FOLLOW, AT_SYMLINK_NOFOLLOW,
-            F_GETLK, F_OFD_GETLK, F_OFD_SETLK, F_RDLCK, F_SETLK, F_SETLKW, F_UNLCK, F_WRLCK, flock,
+            self, AT_EACCESS, AT_EMPTY_PATH, AT_FDCWD, AT_REMOVEDIR, AT_SYMLINK_FOLLOW,
+            AT_SYMLINK_NOFOLLOW, F_GETLK, F_OFD_GETLK, F_OFD_SETLK, F_RDLCK, F_SETLK, F_SETLKW,
+            F_UNLCK, F_WRLCK, flock,
         },
         limits,
         pthread::{pthread_cancel, pthread_create},
@@ -107,7 +108,15 @@ pub struct Sys;
 
 impl Pal for Sys {
     fn access(path: CStr, mode: c_int) -> Result<()> {
-        let fd = FdGuard::new(Sys::open(path, fcntl::O_PATH | fcntl::O_CLOEXEC, 0)? as usize);
+        Sys::faccessat(AT_FDCWD, path, mode, 0)
+    }
+
+    fn faccessat(fd: c_int, path: CStr, mode: c_int, flags: c_int) -> Result<()> {
+        let fd = FdGuard::new(Sys::openat(fd, path, fcntl::O_PATH | fcntl::O_CLOEXEC, 0)? as usize);
+
+        if (flags & !(AT_EACCESS)) != 0 {
+            return Err(Errno(EINVAL));
+        }
 
         if mode == F_OK {
             return Ok(());
@@ -117,11 +126,22 @@ impl Pal for Sys {
 
         fd.fstat(&mut stat)?;
 
-        let Resugid { ruid, rgid, .. } = redox_rt::sys::posix_getresugid();
+        let Resugid {
+            ruid,
+            rgid,
+            euid,
+            egid,
+            ..
+        } = redox_rt::sys::posix_getresugid();
+        let (uid, gid) = if (flags & AT_EACCESS) == AT_EACCESS {
+            (euid, egid)
+        } else {
+            (ruid, rgid)
+        };
 
-        let perms = (if stat.st_uid == ruid {
+        let perms = (if stat.st_uid == uid {
             stat.st_mode >> (3 * 2)
-        } else if stat.st_gid == rgid {
+        } else if stat.st_gid == gid {
             stat.st_mode >> (3 * 1)
         } else {
             stat.st_mode
@@ -277,7 +297,7 @@ impl Pal for Sys {
     fn fchmodat(dirfd: c_int, path: Option<CStr>, mode: mode_t, flags: c_int) -> Result<()> {
         const MASK: c_int = !(fcntl::AT_SYMLINK_NOFOLLOW | fcntl::AT_EMPTY_PATH);
         if MASK & flags != 0 {
-            return Err(Errno(EOPNOTSUPP));
+            return Err(Errno(EINVAL));
         }
         let mut path = path
             .and_then(|cs| str::from_utf8(cs.to_bytes()).ok())
@@ -306,6 +326,21 @@ impl Pal for Sys {
         Ok(())
     }
 
+    fn fchownat(fildes: c_int, path: CStr, owner: uid_t, group: gid_t, flags: c_int) -> Result<()> {
+        const MASK: c_int = !(fcntl::AT_SYMLINK_NOFOLLOW | fcntl::AT_EMPTY_PATH);
+        if MASK & flags != 0 {
+            return Err(Errno(EINVAL));
+        }
+        let path = path.to_str().map_err(|_| Errno(EINVAL))?;
+        let file = openat2(fildes, path, flags, 0)?;
+        libredox::fchown(
+            *file as usize,
+            owner.try_into().map_err(|_| Errno(EINVAL))?,
+            group.try_into().map_err(|_| Errno(EINVAL))?,
+        )?;
+        Ok(())
+    }
+
     fn fcntl(fd: c_int, cmd: c_int, args: c_ulonglong) -> Result<c_int> {
         match cmd {
             F_SETLK | F_OFD_SETLK => {