Add memfd functionality

4 files changed, 51 insertions, 1 deletions

diff --git a/src/fcntl.rs b/src/fcntl.rs
index 1bc11c74..6a0fdf96 100644
--- a/src/fcntl.rs
+++ b/src/fcntl.rs
@@ -40,6 +40,14 @@ mod ffi {
         pub const F_SETLK:         c_int = 6;
         pub const F_SETLKW:        c_int = 7;
         pub const F_GETLK:         c_int = 5;
+
+        pub const F_ADD_SEALS:     c_int = 1033;
+        pub const F_GET_SEALS:     c_int = 1034;
+
+        pub const F_SEAL_SEAL:     c_int = 1;
+        pub const F_SEAL_SHRINK:   c_int = 2;
+        pub const F_SEAL_GROW:     c_int = 4;
+        pub const F_SEAL_WRITE:    c_int = 8;
     }
 
     #[cfg(any(target_os = "macos", target_os = "freebsd", target_os = "ios", target_os = "openbsd"))]
@@ -98,7 +106,11 @@ pub enum FcntlArg<'a> {
     #[cfg(any(target_os = "linux", target_os = "android"))]
     F_OFD_SETLKW(&'a flock),
     #[cfg(any(target_os = "linux", target_os = "android"))]
-    F_OFD_GETLK(&'a mut flock)
+    F_OFD_GETLK(&'a mut flock),
+    #[cfg(target_os = "linux")]
+    F_ADD_SEALS(SealFlag),
+    #[cfg(target_os = "linux")]
+    F_GET_SEALS,
 
     // TODO: Rest of flags
 }
@@ -118,6 +130,10 @@ pub fn fcntl(fd: RawFd, arg: FcntlArg) -> Result<c_int> {
             F_SETLK(flock) => ffi::fcntl(fd, ffi::F_SETLK, flock),
             F_SETLKW(flock) => ffi::fcntl(fd, ffi::F_SETLKW, flock),
             F_GETLK(flock) => ffi::fcntl(fd, ffi::F_GETLK, flock),
+            #[cfg(target_os = "linux")]
+            F_ADD_SEALS(flag) => ffi::fcntl(fd, ffi::F_ADD_SEALS, flag.bits()),
+            #[cfg(target_os = "linux")]
+            F_GET_SEALS => ffi::fcntl(fd, ffi::F_GET_SEALS),
             #[cfg(any(target_os = "linux", target_os = "android"))]
             _ => unimplemented!()
         }
@@ -195,6 +211,16 @@ mod consts {
             const FD_CLOEXEC = 1
         }
     );
+
+    bitflags!(
+        flags SealFlag: c_int {
+            const F_SEAL_SEAL = 1,
+            const F_SEAL_SHRINK = 2,
+            const F_SEAL_GROW = 4,
+            const F_SEAL_WRITE = 8,
+        }
+    );
+
 }
 
 #[cfg(any(target_os = "macos", target_os = "ios"))]
diff --git a/src/sys/memfd.rs b/src/sys/memfd.rs
new file mode 100644
index 00000000..e142218f
--- /dev/null
+++ b/src/sys/memfd.rs
@@ -0,0 +1,18 @@
+use libc;
+use std::os::unix::io::RawFd;
+use {Error, Result};
+use std::ffi::CStr;
+
+bitflags!(
+    flags MemFdCreateFlag: libc::c_uint {
+        const MFD_CLOEXEC       = 0x0001,
+        const MFD_ALLOW_SEALING = 0x0002,
+    }
+);
+
+pub fn memfd_create(name: &CStr, flags: MemFdCreateFlag) -> Result<RawFd> {
+    use sys::syscall::{syscall, MEMFD_CREATE};
+    let res = unsafe { syscall(MEMFD_CREATE, name.as_ptr(), flags.bits()) };
+    if res == -1 { Err(Error::last()) }
+    else { Ok(res as RawFd) }
+}
diff --git a/src/sys/mod.rs b/src/sys/mod.rs
index c124359d..3df06c44 100644
--- a/src/sys/mod.rs
+++ b/src/sys/mod.rs
@@ -9,6 +9,9 @@ pub mod event;
 #[cfg(feature = "eventfd")]
 pub mod eventfd;
 
+#[cfg(target_os = "linux")]
+pub mod memfd;
+
 #[cfg(not(any(target_os = "ios", target_os = "freebsd")))]
 pub mod ioctl;
 
diff --git a/src/sys/syscall.rs b/src/sys/syscall.rs
index 0f6a5e0b..c80defa2 100644
--- a/src/sys/syscall.rs
+++ b/src/sys/syscall.rs
@@ -11,6 +11,7 @@ mod arch {
     pub type Syscall = c_long;
 
     pub static SYSPIVOTROOT: Syscall = 155;
+    pub static MEMFD_CREATE: Syscall = 319;
 }
 
 #[cfg(target_arch = "x86")]
@@ -20,6 +21,7 @@ mod arch {
     pub type Syscall = c_long;
 
     pub static SYSPIVOTROOT: Syscall = 217;
+    pub static MEMFD_CREATE: Syscall = 356;
 }
 
 #[cfg(target_arch = "arm")]
@@ -29,6 +31,7 @@ mod arch {
     pub type Syscall = c_long;
 
     pub static SYSPIVOTROOT: Syscall = 218;
+    pub static MEMFD_CREATE: Syscall = 385;
 }