Implement better heck encoding (not used yet)

Makefile

@@ -4,6 +4,8 @@ all: release-build
 
 debug-build:
 	cargo build
+	cp ./target/debug/hptp-recv ./3700recv
+	cp ./target/debug/hptp-send ./3700send
 
 release-build:
 	cargo build --release

hptp/src/encoding.rs

@@ -7,16 +7,16 @@ lazy_static! {
 
 static WRAP_SIZE: usize = 60;
 
-pub fn can_be_encoded(data: &[u8]) -> bool {
-    ENCODING_DETECTOR.is_match(data)
-}
-
 #[derive(Clone)]
 pub struct MeowCoder {
     line_index: usize,
 }
 
 impl MeowCoder {
+    pub fn can_be_encoded(data: &[u8]) -> bool {
+        ENCODING_DETECTOR.is_match(data)
+    }
+
     pub fn new() -> MeowCoder {
         MeowCoder{line_index: 0}
     }
@@ -43,7 +43,7 @@ impl MeowCoder {
         (LOOKUP[first as usize], LOOKUP[second as usize])
     }
 
-    pub fn encode(input: &Vec<u8>) -> Vec<u8> {
+    pub fn encode(input: &Vec<u8>) -> (Vec<u8>, bool) {
         let mut out: Vec<u8> = Vec::new();
         let mut prev_char: u8 = 0;
         let mut pair_first = false;
@@ -61,15 +61,23 @@ impl MeowCoder {
                 pair_first = false;
             }
         }
-        out
+        // trailing byte specifies whether this was cut or not
+        if pair_first {
+            out.push(MeowCoder::hex_to_nibble(prev_char) * 16);
+            (out, true)
+        } else {
+            (out, false)
+        }
     }
 
-    pub fn decode(&mut self, input: &Vec<u8>) -> Vec<u8> {
+    pub fn decode(&mut self, input: &Vec<u8>, was_cut: bool) -> Vec<u8> {
         let mut out: Vec<u8> = Vec::new();
-        for byte in input {
+        for (pos, byte) in input.iter().enumerate() {
             let (first, second) = MeowCoder::u8_to_hex(*byte);
             out.push(first);
-            out.push(second);
+            if pos < input.len() - 1 || !was_cut {
+                out.push(second);
+            }
             self.line_index += 2;
             if self.line_index == WRAP_SIZE {
                 self.line_index = 0;
@@ -86,27 +94,43 @@ mod tests {
 
     #[test]
     fn test_match() {
-        assert_eq!(can_be_encoded(b"abcd1234"), true);
+        assert_eq!(MeowCoder::can_be_encoded(b"abcd1234"), true);
-        assert_eq!(can_be_encoded(b"abcXd1234"), false);
+        assert_eq!(MeowCoder::can_be_encoded(b"abcXd1234"), false);
-        assert_eq!(can_be_encoded(b"012345678901234567890123456789012345678901234567890123456789\nabcdef"), true);
+        assert_eq!(MeowCoder::can_be_encoded(b"012345678901234567890123456789012345678901234567890123456789\nabcdef"), true);
-        assert_eq!(can_be_encoded(b"01234567890123456789012345678901234567890123456789012345678\nabcdef"), false);
+        assert_eq!(MeowCoder::can_be_encoded(b"01234567890123456789012345678901234567890123456789012345678\nabcdef"), false);
-        assert_eq!(can_be_encoded(b"\x12\xab\x45\n"), false);
+        assert_eq!(MeowCoder::can_be_encoded(b"\x12\xab\x45\n"), false);
     }
 
     #[test]
     fn test_encode() {
         let vec = vec!['a' as u8, '4' as u8, 'c' as u8, 'd' as u8,
             '\n' as u8, 'e' as u8, 'f' as u8];
-        assert_eq!(MeowCoder::encode(&vec), vec![0xa4, 0xcd, 0xef]);
+        assert_eq!(MeowCoder::encode(&vec), (vec![0xa4, 0xcd, 0xef], false));
+
+        let vec2 = vec!['a' as u8, '4' as u8, 'c' as u8, 'd' as u8,
+            '\n' as u8, 'e' as u8, 'f' as u8, '9' as u8];
+        assert_eq!(MeowCoder::encode(&vec2), (vec![0xa4, 0xcd, 0xef, 0x90], true));
     }
 
     #[test]
     fn test_encode_decode() {
         let hex_str: &[u8] = b"012345678901234567890123456789012345678901234567890123456789\nabcdef";
         let vec: Vec<u8> = Vec::from(hex_str);
-        let vec2 = MeowCoder::encode(&vec);
+        let (vec2, was_cut) = MeowCoder::encode(&vec);
+        assert_eq!(was_cut, false);
         let mut coder = MeowCoder::new();
-        let out = coder.decode(&vec2);
+        let out = coder.decode(&vec2, was_cut);
+        assert_eq!(out, vec);
+    }
+
+    #[test]
+    fn test_encode_decode_cut() {
+        let hex_str: &[u8] = b"012345678901234567890123456789012345678901234567890123456789\nabcdef3";
+        let vec: Vec<u8> = Vec::from(hex_str);
+        let (vec2, was_cut) = MeowCoder::encode(&vec);
+        assert_eq!(was_cut, true);
+        let mut coder = MeowCoder::new();
+        let out = coder.decode(&vec2, was_cut);
         assert_eq!(out, vec);
     }
 }

hptp/src/msg.rs

@@ -31,6 +31,7 @@ pub trait SerDes: Sized {
 type BO = byteorder::LE;
 
 const LAST_SEG_MASK: u32 = 1 << 31;
+const MEOW_CODED_MASK: u32 = 1 << 30;
 
 impl SerDes for UpMsg {
     fn des(buf: &[u8]) -> Result<Self, DesError> {
@@ -39,11 +40,11 @@ impl SerDes for UpMsg {
         } else {
             let hdr = BO::read_u32(&buf[0..4]);
             Ok(UpMsg::Data {
-                seg_idx: hdr & !LAST_SEG_MASK,
+                seg_idx: hdr & !LAST_SEG_MASK & !MEOW_CODED_MASK,
                 payload: SegData {
                     bytes: buf[4..].into(),
                     is_last_segment: (hdr & LAST_SEG_MASK) != 0,
-                    is_meow_encoded: false,
+                    is_meow_encoded: (hdr & MEOW_CODED_MASK) != 0,
                 },
             })
         }
@@ -60,7 +61,8 @@ impl SerDes for UpMsg {
                     },
                 seg_idx,
             } => {
-                let hdr = *seg_idx | if *is_last_segment { LAST_SEG_MASK } else { 0 };
+                let hdr = *seg_idx | if *is_last_segment { LAST_SEG_MASK } else { 0 }
+                    | if *is_meow_encoded { MEOW_CODED_MASK } else { 0 };
                 BO::write_u32(&mut buf[0..4], hdr);
                 let len = bytes.len();
                 buf[4..4 + len].copy_from_slice(&bytes[..]);

hptp/src/seg.rs

@@ -50,7 +50,7 @@ pub struct SegmentSet {
 
 #[derive(Clone)]
 pub struct SegData {
-    pub(crate) bytes: Vec<u8>,
+    pub bytes: Vec<u8>,
     pub is_last_segment: bool,
     pub is_meow_encoded: bool,
 }

scripts/create-net-ns.sh

@@ -8,5 +8,5 @@ sudo unshare -n capsh --caps="cap_net_admin+eip cap_setpcap,cap_setuid,cap_setgi
     -- -c "export PATH=$PWD/.netsim:\$PATH; export HOME=$PWD; /usr/bin/ip link set lo up; netsim; \
            export PERL5LIB=\"/home/$USER/perl5/lib/perl5\${PERL5LIB:+:\${PERL5LIB}}\" \
            export PERL_LOCAL_LIB_ROOT=\"/home/$USER/perl5\${PERL_LOCAL_LIB_ROOT:+:\${PERL_LOCAL_LIB_ROOT}}\" \
-           tc qdisc show dev lo; /bin/bash --init-file <(echo unset HISTFILE)"
+           tc qdisc show dev lo; cd .netsim; /bin/bash --init-file <(echo unset HISTFILE)"
 true