scheme-utils: Have FpathWriter handle writing the scheme name

netstack/src/scheme/icmp.rs

@@ -250,14 +250,14 @@ impl<'a> SchemeSocket for IcmpSocket<'a> {
     }
 
     fn fpath(&self, file: &SchemeFile<Self>, buf: &mut [u8]) -> SyscallResult<usize> {
-        FpathWriter::with(buf, |w| {
+        FpathWriter::with(buf, "icmp", |w| {
             if let SchemeFile::Socket(ref socket_file) = *file {
                 match socket_file.data.socket_type {
                     IcmpSocketType::Echo => {
-                        write!(w, "/scheme/icmp/echo/{}", socket_file.data.ip).unwrap();
+                        write!(w, "echo/{}", socket_file.data.ip).unwrap();
                     }
                     IcmpSocketType::Udp => {
-                        write!(w, "/scheme/icmp/udp/{}", socket_file.data.ip).unwrap();
+                        write!(w, "udp/{}", socket_file.data.ip).unwrap();
                     }
                 }
                 Ok(())

netstack/src/scheme/ip.rs

@@ -138,8 +138,8 @@ impl<'a> SchemeSocket for RawSocket<'a> {
     }
 
     fn fpath(&self, _file: &SchemeFile<Self>, buf: &mut [u8]) -> SyscallResult<usize> {
-        FpathWriter::with(buf, |w| {
-            write!(w, "/scheme/ip/{}", self.ip_protocol()).unwrap();
+        FpathWriter::with(buf, "ip", |w| {
+            write!(w, "{}", self.ip_protocol()).unwrap();
             Ok(())
         })
     }

netstack/src/scheme/tcp.rs

@@ -273,9 +273,8 @@ impl<'a> SchemeSocket for TcpSocket<'a> {
     }
 
     fn fpath(&self, file: &SchemeFile<Self>, buf: &mut [u8]) -> SyscallResult<usize> {
-        FpathWriter::with(buf, |w| {
+        FpathWriter::with(buf, "tcp", |w| {
             let unspecified = "0.0.0.0:0";
-            write!(w, "/scheme/tcp/").unwrap();
             match self.remote_endpoint() {
                 Some(endpoint) => write!(w, "{}", endpoint).unwrap(),
                 None => w.push_str(unspecified),

netstack/src/scheme/udp.rs

@@ -269,9 +269,8 @@ impl<'a> SchemeSocket for UdpSocket<'a> {
     }
 
     fn fpath(&self, file: &SchemeFile<Self>, buf: &mut [u8]) -> SyscallResult<usize> {
-        FpathWriter::with(buf, |w| {
+        FpathWriter::with(buf, "udp", |w| {
             let unspecified = "0.0.0.0:0";
-            w.push_str("/scheme/udp/");
 
             // remote
             match file {