From b07f3752b6f72b57c05b000987b14302eefb195a Mon Sep 17 00:00:00 2001
From: Nikolay Amiantov <ab@fmap.me>
Date: Fri, 19 Feb 2016 17:37:53 +0300
Subject: [PATCH 1/2] unistd: add setuid, setgid syscalls

---
 src/unistd.rs | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/unistd.rs b/src/unistd.rs
index a4e666180c..1e3bdfb8fd 100644
--- a/src/unistd.rs
+++ b/src/unistd.rs
@@ -13,7 +13,7 @@ pub use self::linux::*;
 
 mod ffi {
     use libc::{c_char, c_int, size_t};
-    pub use libc::{fork, close, read, write, pipe, ftruncate, unlink, setpgid, getegid, geteuid, getgid, getpid, getppid, getuid};
+    pub use libc::{fork, close, read, write, pipe, ftruncate, unlink, setpgid, getegid, geteuid, getgid, getpid, getppid, getuid, setuid, setgid};
 
     #[allow(improper_ctypes)]
     extern {
@@ -369,6 +369,20 @@ pub fn getegid() -> gid_t {
     unsafe { ffi::getegid() }
 }
 
+#[inline]
+pub fn setuid(uid: uid_t) -> Result<()> {
+    let res = unsafe { ffi::setuid(uid) };
+
+    Errno::result(res).map(drop)
+}
+
+#[inline]
+pub fn setgid(gid: gid_t) -> Result<()> {
+    let res = unsafe { ffi::setgid(gid) };
+
+    Errno::result(res).map(drop)
+}
+
 #[cfg(any(target_os = "linux", target_os = "android"))]
 mod linux {
     use sys::syscall::{syscall, SYSPIVOTROOT};

From 6a2522cca37a921e39bdf451f46095ba3dfa4566 Mon Sep 17 00:00:00 2001
From: Nikolay Amiantov <ab@fmap.me>
Date: Fri, 19 Feb 2016 17:38:33 +0300
Subject: [PATCH 2/2] unistd: add chown syscall

---
 src/unistd.rs | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/unistd.rs b/src/unistd.rs
index 1e3bdfb8fd..6d793aec2d 100644
--- a/src/unistd.rs
+++ b/src/unistd.rs
@@ -13,7 +13,7 @@ pub use self::linux::*;
 
 mod ffi {
     use libc::{c_char, c_int, size_t};
-    pub use libc::{fork, close, read, write, pipe, ftruncate, unlink, setpgid, getegid, geteuid, getgid, getpid, getppid, getuid, setuid, setgid};
+    pub use libc::{fork, close, read, write, pipe, ftruncate, unlink, setpgid, getegid, geteuid, getgid, getpid, getppid, getuid, setuid, setgid, chown};
 
     #[allow(improper_ctypes)]
     extern {
@@ -28,7 +28,7 @@ mod ffi {
 
         // Execute PATH with arguments ARGV and environment from `environ'.
         // doc: http://man7.org/linux/man-pages/man3/execv.3.html
-        pub fn execv (path: *const c_char, argv: *const *const c_char) -> c_int;
+        pub fn execv(path: *const c_char, argv: *const *const c_char) -> c_int;
 
         // execute program
         // doc: http://man7.org/linux/man-pages/man2/execve.2.html
@@ -157,6 +157,16 @@ pub fn chdir<P: ?Sized + NixPath>(path: &P) -> Result<()> {
     Errno::result(res).map(drop)
 }
 
+#[inline]
+pub fn chown<P: ?Sized + NixPath>(path: &P, owner: Option<uid_t>, group: Option<gid_t>) -> Result<()> {
+    let res = try!(path.with_nix_path(|cstr| {
+        // We use `0 - 1` to get `-1 : {u,g}id_t` which is specified as the no-op value for chown(3).
+        unsafe { ffi::chown(cstr.as_ptr(), owner.unwrap_or(0 - 1), group.unwrap_or(0 - 1)) }
+    }));
+
+    Errno::result(res).map(drop)
+}
+
 fn to_exec_array(args: &[CString]) -> Vec<*const c_char> {
     use std::ptr;
     use libc::c_char;