From a9c7a4e773382093ed8d8ead4afad560d921afda Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Tue, 15 Nov 2016 17:08:14 -0700
Subject: [PATCH] Update to add chmod

---
 scheme/user.rs |  8 ++++++++
 syscall/fs.rs  | 22 ++++++++++++++++++++++
 syscall/mod.rs |  1 +
 3 files changed, 31 insertions(+)

diff --git a/scheme/user.rs b/scheme/user.rs
index 3a8c4af..da19500 100644
--- a/scheme/user.rs
+++ b/scheme/user.rs
@@ -231,6 +231,14 @@ impl Scheme for UserScheme {
         result
     }
 
+    fn chmod(&self, path: &[u8], mode: u16, _uid: u32, _gid: u32) -> Result<usize> {
+        let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
+        let address = inner.capture(path)?;
+        let result = inner.call(SYS_CHMOD, address, path.len(), mode as usize);
+        let _ = inner.release(address);
+        result
+    }
+
     fn rmdir(&self, path: &[u8], _uid: u32, _gid: u32) -> Result<usize> {
         let inner = self.inner.upgrade().ok_or(Error::new(ENODEV))?;
         let address = inner.capture(path)?;
diff --git a/syscall/fs.rs b/syscall/fs.rs
index c12dc89..b10a34a 100644
--- a/syscall/fs.rs
+++ b/syscall/fs.rs
@@ -166,6 +166,28 @@ pub fn mkdir(path: &[u8], mode: u16) -> Result<usize> {
     scheme.mkdir(reference_opt.unwrap_or(b""), mode, uid, gid)
 }
 
+/// chmod syscall
+pub fn chmod(path: &[u8], mode: u16) -> Result<usize> {
+    let (path_canon, uid, gid) = {
+        let contexts = context::contexts();
+        let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+        let context = context_lock.read();
+        (context.canonicalize(path), context.euid, context.egid)
+    };
+
+    let mut parts = path_canon.splitn(2, |&b| b == b':');
+    let namespace_opt = parts.next();
+    let reference_opt = parts.next();
+
+    let namespace = namespace_opt.ok_or(Error::new(ENODEV))?;
+    let scheme = {
+        let schemes = scheme::schemes();
+        let (_scheme_id, scheme) = schemes.get_name(namespace).ok_or(Error::new(ENODEV))?;
+        scheme.clone()
+    };
+    scheme.chmod(reference_opt.unwrap_or(b""), mode, uid, gid)
+}
+
 /// rmdir syscall
 pub fn rmdir(path: &[u8]) -> Result<usize> {
     let (path_canon, uid, gid) = {
diff --git a/syscall/mod.rs b/syscall/mod.rs
index b34df1d..89058df 100644
--- a/syscall/mod.rs
+++ b/syscall/mod.rs
@@ -54,6 +54,7 @@ pub extern fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize
             SYS_CLASS_PATH => match a {
                 SYS_OPEN => open(validate_slice(b as *const u8, c)?, d).map(FileHandle::into),
                 SYS_MKDIR => mkdir(validate_slice(b as *const u8, c)?, d as u16),
+                SYS_CHMOD => chmod(validate_slice(b as *const u8, c)?, d as u16),
                 SYS_RMDIR => rmdir(validate_slice(b as *const u8, c)?),
                 SYS_UNLINK => unlink(validate_slice(b as *const u8, c)?),
                 _ => unreachable!()