Handle incoming frames in TNC

[m17rt] / m17core / src / protocol.rs

diff --git a/m17core/src/protocol.rs b/m17core/src/protocol.rs
index 96def5b8913ffdcc245baa7998a934ff470043d9..82a5721b543752cf8369f5d00554f429beaa2efb 100755 (executable)
--- a/m17core/src/protocol.rs
+++ b/m17core/src/protocol.rs
@@ -29,10 +29,11 @@ pub enum EncryptionType {
 pub enum Frame {
     Lsf(LsfFrame),
     Stream(StreamFrame),
-    // Packet
+    Packet(PacketFrame),
     // BERT
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum PacketType {
     /// RAW
     Raw,
@@ -53,6 +54,22 @@ pub enum PacketType {
 }
 
 impl PacketType {
+    pub fn from_proto(buf: &[u8]) -> Option<(Self, usize)> {
+        buf.utf8_chunks()
+            .next()
+            .and_then(|chunk| chunk.valid().chars().next())
+            .map(|c| match c as u32 {
+                0x00 => (PacketType::Raw, 1),
+                0x01 => (PacketType::Ax25, 1),
+                0x02 => (PacketType::Aprs, 1),
+                0x03 => (PacketType::SixLowPan, 1),
+                0x04 => (PacketType::Ipv4, 1),
+                0x05 => (PacketType::Sms, 1),
+                0x06 => (PacketType::Winlink, 1),
+                _ => (PacketType::Other(c), c.len_utf8()),
+            })
+    }
+
     pub fn as_proto(&self) -> ([u8; 4], usize) {
         match self {
             PacketType::Raw => ([0, 0, 0, 0], 1),
@@ -70,22 +87,6 @@ impl PacketType {
             }
         }
     }
-
-    pub fn from_proto(&self, buf: &[u8]) -> Option<PacketType> {
-        buf.utf8_chunks()
-            .next()
-            .and_then(|chunk| chunk.valid().chars().next())
-            .map(|c| match c as u32 {
-                0x00 => PacketType::Raw,
-                0x01 => PacketType::Ax25,
-                0x02 => PacketType::Aprs,
-                0x03 => PacketType::SixLowPan,
-                0x04 => PacketType::Ipv4,
-                0x05 => PacketType::Sms,
-                0x06 => PacketType::Winlink,
-                _ => PacketType::Other(c),
-            })
-    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -132,6 +133,8 @@ impl LsfFrame {
         }
     }
 
+    // TODO: encryption sub-type
+
     pub fn channel_access_number(&self) -> u8 {
         (self.0[12] >> 7) & 0x0f
     }
@@ -155,6 +158,33 @@ pub struct StreamFrame {
     pub stream_data: [u8; 16],
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct PacketFrame {
+    /// Application packet payload (chunk)
+    pub payload: [u8; 25],
+
+    /// Frame counter, which provides different information depending on whether this is the last frame or not.
+    pub counter: PacketFrameCounter,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum PacketFrameCounter {
+    /// Any packet frame that comes after the LSF and is not the final frame.
+    Frame {
+        /// Which frame this is in the superframe, from 0 to 31 inclusive.
+        ///
+        /// If a 33rd frame exists (index 32), it will be a `FinalFrame` instead.
+        ///
+        /// All 25 bytes of of `payload` are filled and valid.
+        index: usize,
+    },
+    /// The final frame in the packet superframe.
+    FinalFrame {
+        /// The number of bytes in `payload` that are filled.
+        payload_len: usize,
+    },
+}
+
 pub struct LichCollection([Option<[u8; 5]>; 6]);
 
 impl LichCollection {