X-Git-Url: https://code.octet-stream.net/m17rt/blobdiff_plain/1f1869d3e36f7192892fad069ef159faba208ccd..2c7d53c113f4e19f24c928b2c5eca1c3f6f799af:/m17core/src/reflector/packet.rs

diff --git a/m17core/src/reflector/packet.rs b/m17core/src/reflector/packet.rs
new file mode 100644
index 0000000..3f746d6
--- /dev/null
+++ b/m17core/src/reflector/packet.rs
@@ -0,0 +1,548 @@
+//! UDP datagrams and binary encoding/decoding for client-reflector and reflector-reflector communication.
+
+use crate::address::Address;
+use crate::protocol::LsfFrame;
+
+macro_rules! define_message {
+    ($t:tt, $sz:tt, $min_sz:tt, $magic:tt) => {
+        pub struct $t(pub [u8; $sz], pub usize);
+
+        impl $t {
+            pub fn new() -> Self {
+                let mut bytes = [0u8; $sz];
+                bytes[0..4].copy_from_slice($magic);
+                Self(bytes, $sz)
+            }
+
+            #[allow(clippy::double_comparisons)] // occurs in some macro invocations
+            #[allow(clippy::manual_range_contains)] // way more readable, good grief
+            pub fn from_bytes(b: &[u8]) -> Option<Self> {
+                let len = b.len();
+                if len > $sz || len < $min_sz {
+                    return None;
+                }
+                let mut s = Self([0; $sz], len);
+                s.0[0..len].copy_from_slice(b);
+                if !s.verify_integrity() {
+                    return None;
+                }
+                Some(s)
+            }
+
+            pub fn as_bytes(&self) -> &[u8] {
+                &self.0[0..self.1]
+            }
+        }
+
+        impl Default for $t {
+            fn default() -> Self {
+                Self::new()
+            }
+        }
+    };
+}
+
+macro_rules! impl_stream_id {
+    ($t:ty, $from:tt) => {
+        impl $t {
+            pub fn stream_id(&self) -> u16 {
+                u16::from_be_bytes([self.0[$from], self.0[$from + 1]])
+            }
+
+            pub fn set_stream_id(&mut self, id: u16) {
+                let bytes = id.to_be_bytes();
+                self.0[$from] = bytes[0];
+                self.0[$from + 1] = bytes[1];
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+macro_rules! impl_link_setup {
+    ($t:ty, $from:tt) => {
+        impl $t {
+            pub fn link_setup_frame(&self) -> LsfFrame {
+                let mut frame = LsfFrame([0; 30]);
+                frame.0[0..28].copy_from_slice(&self.0[$from..($from + 28)]);
+                frame.recalculate_crc();
+                frame
+            }
+
+            pub fn set_link_setup_frame(&mut self, lsf: &LsfFrame) {
+                self.0[$from..($from + 28)].copy_from_slice(&lsf.0[0..28]);
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+macro_rules! impl_link_setup_frame {
+    ($t:ty, $from:tt) => {
+        impl $t {
+            pub fn link_setup_frame(&self) -> LsfFrame {
+                let mut frame = LsfFrame([0; 30]);
+                frame.0[..].copy_from_slice(&self.0[$from..($from + 30)]);
+                frame
+            }
+
+            pub fn set_link_setup_frame(&mut self, lsf: &LsfFrame) {
+                debug_assert_eq!(lsf.check_crc(), 0);
+                self.0[$from..($from + 30)].copy_from_slice(&lsf.0);
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+macro_rules! impl_frame_number {
+    ($t:ty, $from:tt) => {
+        impl $t {
+            pub fn frame_number(&self) -> u16 {
+                let frame_num = u16::from_be_bytes([self.0[$from], self.0[$from + 1]]);
+                frame_num & 0x7fff
+            }
+
+            pub fn is_end_of_stream(&self) -> bool {
+                let frame_num = u16::from_be_bytes([self.0[$from], self.0[$from + 1]]);
+                (frame_num & 0x8000) > 0
+            }
+
+            pub fn set_frame_number(&mut self, number: u16) {
+                let existing_eos = u16::from_be_bytes([self.0[$from], self.0[$from + 1]]) & 0x8000;
+                let new = (existing_eos | (number & 0x7fff)).to_be_bytes();
+                self.0[$from] = new[0];
+                self.0[$from + 1] = new[1];
+                self.recalculate_crc();
+            }
+
+            pub fn set_end_of_stream(&mut self, eos: bool) {
+                let existing_fn = u16::from_be_bytes([self.0[$from], self.0[$from + 1]]) & 0x7fff;
+                let new = (existing_fn | (if eos { 0x8000 } else { 0 })).to_be_bytes();
+                self.0[$from] = new[0];
+                self.0[$from + 1] = new[1];
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+macro_rules! impl_payload {
+    ($t:ty, $from:tt, $to:tt) => {
+        impl $t {
+            pub fn payload(&self) -> &[u8] {
+                &self.0[$from..$to]
+            }
+
+            pub fn set_payload(&mut self, bytes: &[u8]) {
+                self.0[$from..$to].copy_from_slice(bytes);
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+macro_rules! impl_modules {
+    ($t:ty, $from:tt, $to:tt) => {
+        impl $t {
+            pub fn modules(&self) -> ModulesIterator {
+                ModulesIterator::new(&self.0[$from..$to])
+            }
+
+            pub fn set_modules(&mut self, list: &str) {
+                debug_assert!(list.len() < 27);
+                let mut idx = $from;
+                for m in list.chars() {
+                    self.0[idx] = m as u8;
+                    idx += 1;
+                }
+                self.0[idx] = 0;
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+macro_rules! impl_module {
+    ($t:ty, $at:tt) => {
+        impl $t {
+            pub fn module(&self) -> char {
+                self.0[$at] as char
+            }
+
+            pub fn set_module(&mut self, m: char) {
+                self.0[$at] = m as u8;
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+macro_rules! impl_address {
+    ($t:ty, $from:tt) => {
+        impl $t {
+            pub fn address(&self) -> Address {
+                crate::address::decode_address(self.0[$from..($from + 6)].try_into().unwrap())
+            }
+
+            pub fn set_address(&mut self, address: Address) {
+                let encoded = crate::address::encode_address(&address);
+                self.0[$from..($from + 6)].copy_from_slice(&encoded);
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+macro_rules! impl_trailing_crc_verify {
+    ($t:ty) => {
+        impl $t {
+            pub fn verify_integrity(&self) -> bool {
+                crate::crc::m17_crc(&self.0) == 0
+            }
+
+            pub fn recalculate_crc(&mut self) {
+                let len = self.0.len();
+                let start_crc = crate::crc::m17_crc(&self.0[0..(len - 2)]).to_be_bytes();
+                self.0[len - 2] = start_crc[0];
+                self.0[len - 1] = start_crc[1];
+                debug_assert!(self.verify_integrity());
+            }
+        }
+    };
+}
+
+macro_rules! impl_internal_crc {
+    ($t:ty, $from:tt, $to:tt) => {
+        impl $t {
+            pub fn verify_integrity(&self) -> bool {
+                crate::crc::m17_crc(&self.0[$from..$to]) == 0
+            }
+
+            pub fn recalculate_crc(&mut self) {
+                // assume the last two bytes of the range are the CRC
+                let start_crc = crate::crc::m17_crc(&self.0[$from..($to - 2)]).to_be_bytes();
+                self.0[$to - 2] = start_crc[0];
+                self.0[$to - 1] = start_crc[1];
+                debug_assert!(self.verify_integrity());
+            }
+        }
+    };
+}
+
+macro_rules! no_crc {
+    ($t:ty) => {
+        impl $t {
+            pub fn verify_integrity(&self) -> bool {
+                true
+            }
+            pub fn recalculate_crc(&mut self) {}
+        }
+    };
+}
+
+macro_rules! impl_is_relayed {
+    ($t:ty) => {
+        impl $t {
+            pub fn is_relayed(&self) -> bool {
+                self.0[self.0.len() - 1] != 0
+            }
+
+            pub fn set_relayed(&mut self, relayed: bool) {
+                self.0[self.0.len() - 1] = if relayed { 1 } else { 0 };
+                self.recalculate_crc();
+            }
+        }
+    };
+}
+
+pub struct ModulesIterator<'a> {
+    modules: &'a [u8],
+    idx: usize,
+}
+
+impl<'a> ModulesIterator<'a> {
+    fn new(modules: &'a [u8]) -> Self {
+        Self { modules, idx: 0 }
+    }
+}
+
+impl Iterator for ModulesIterator<'_> {
+    type Item = char;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.idx < self.modules.len() {
+            if self.modules[self.idx] == 0 {
+                return None;
+            }
+            self.idx += 1;
+            return Some(self.modules[self.idx - 1] as char);
+        }
+        None
+    }
+}
+
+pub const MAGIC_VOICE: &[u8] = b"M17 ";
+pub const MAGIC_VOICE_HEADER: &[u8] = b"M17H";
+pub const MAGIC_VOICE_DATA: &[u8] = b"M17D";
+pub const MAGIC_PACKET: &[u8] = b"M17P";
+pub const MAGIC_ACKNOWLEDGE: &[u8] = b"ACKN";
+pub const MAGIC_CONNECT: &[u8] = b"CONN";
+pub const MAGIC_DISCONNECT: &[u8] = b"DISC";
+pub const MAGIC_LISTEN: &[u8] = b"LSTN";
+pub const MAGIC_NACK: &[u8] = b"NACK";
+pub const MAGIC_PING: &[u8] = b"PING";
+pub const MAGIC_PONG: &[u8] = b"PONG";
+
+/// Messages sent from a station/client to a reflector
+#[allow(clippy::large_enum_variant)]
+pub enum ClientMessage {
+    Voice(Voice),
+    VoiceHeader(VoiceHeader),
+    VoiceData(VoiceData),
+    Packet(Packet),
+    Pong(Pong),
+    Connect(Connect),
+    Listen(Listen),
+    Disconnect(Disconnect),
+}
+
+impl ClientMessage {
+    pub fn parse(bytes: &[u8]) -> Option<Self> {
+        if bytes.len() < 4 {
+            return None;
+        }
+        match &bytes[0..4] {
+            MAGIC_VOICE => Some(Self::Voice(Voice::from_bytes(bytes)?)),
+            MAGIC_VOICE_HEADER => Some(Self::VoiceHeader(VoiceHeader::from_bytes(bytes)?)),
+            MAGIC_VOICE_DATA => Some(Self::VoiceData(VoiceData::from_bytes(bytes)?)),
+            MAGIC_PACKET => Some(Self::Packet(Packet::from_bytes(bytes)?)),
+            MAGIC_PONG => Some(Self::Pong(Pong::from_bytes(bytes)?)),
+            MAGIC_CONNECT => Some(Self::Connect(Connect::from_bytes(bytes)?)),
+            MAGIC_LISTEN => Some(Self::Listen(Listen::from_bytes(bytes)?)),
+            MAGIC_DISCONNECT => Some(Self::Disconnect(Disconnect::from_bytes(bytes)?)),
+            _ => None,
+        }
+    }
+}
+
+/// Messages sent from a reflector to a station/client
+#[allow(clippy::large_enum_variant)]
+pub enum ServerMessage {
+    Voice(Voice),
+    VoiceHeader(VoiceHeader),
+    VoiceData(VoiceData),
+    Packet(Packet),
+    Ping(Ping),
+    DisconnectAcknowledge(DisconnectAcknowledge),
+    ForceDisconnect(ForceDisconnect),
+    ConnectAcknowledge(ConnectAcknowledge),
+    ConnectNack(ConnectNack),
+}
+
+impl ServerMessage {
+    pub fn parse(bytes: &[u8]) -> Option<Self> {
+        if bytes.len() < 4 {
+            return None;
+        }
+        match &bytes[0..4] {
+            MAGIC_VOICE => Some(Self::Voice(Voice::from_bytes(bytes)?)),
+            MAGIC_VOICE_HEADER => Some(Self::VoiceHeader(VoiceHeader::from_bytes(bytes)?)),
+            MAGIC_VOICE_DATA => Some(Self::VoiceData(VoiceData::from_bytes(bytes)?)),
+            MAGIC_PACKET => Some(Self::Packet(Packet::from_bytes(bytes)?)),
+            MAGIC_PING => Some(Self::Ping(Ping::from_bytes(bytes)?)),
+            MAGIC_DISCONNECT if bytes.len() == 4 => Some(Self::DisconnectAcknowledge(
+                DisconnectAcknowledge::from_bytes(bytes)?,
+            )),
+            MAGIC_DISCONNECT => Some(Self::ForceDisconnect(ForceDisconnect::from_bytes(bytes)?)),
+            MAGIC_ACKNOWLEDGE => Some(Self::ConnectAcknowledge(ConnectAcknowledge::from_bytes(
+                bytes,
+            )?)),
+            MAGIC_NACK => Some(Self::ConnectNack(ConnectNack::from_bytes(bytes)?)),
+            _ => None,
+        }
+    }
+}
+
+/// Messages sent and received between reflectors
+#[allow(clippy::large_enum_variant)]
+pub enum InterlinkMessage {
+    VoiceInterlink(VoiceInterlink),
+    VoiceHeaderInterlink(VoiceHeaderInterlink),
+    VoiceDataInterlink(VoiceDataInterlink),
+    PacketInterlink(PacketInterlink),
+    Ping(Ping),
+    ConnectInterlink(ConnectInterlink),
+    ConnectInterlinkAcknowledge(ConnectInterlinkAcknowledge),
+    ConnectNack(ConnectNack),
+    DisconnectInterlink(DisconnectInterlink),
+}
+
+impl InterlinkMessage {
+    pub fn parse(bytes: &[u8]) -> Option<Self> {
+        if bytes.len() < 4 {
+            return None;
+        }
+        match &bytes[0..4] {
+            MAGIC_VOICE => Some(Self::VoiceInterlink(VoiceInterlink::from_bytes(bytes)?)),
+            MAGIC_VOICE_HEADER => Some(Self::VoiceHeaderInterlink(
+                VoiceHeaderInterlink::from_bytes(bytes)?,
+            )),
+            MAGIC_VOICE_DATA => Some(Self::VoiceDataInterlink(VoiceDataInterlink::from_bytes(
+                bytes,
+            )?)),
+            MAGIC_PACKET => Some(Self::PacketInterlink(PacketInterlink::from_bytes(bytes)?)),
+            MAGIC_PING => Some(Self::Ping(Ping::from_bytes(bytes)?)),
+            MAGIC_CONNECT => Some(Self::ConnectInterlink(ConnectInterlink::from_bytes(bytes)?)),
+            MAGIC_ACKNOWLEDGE => Some(Self::ConnectInterlinkAcknowledge(
+                ConnectInterlinkAcknowledge::from_bytes(bytes)?,
+            )),
+            MAGIC_NACK => Some(Self::ConnectNack(ConnectNack::from_bytes(bytes)?)),
+            MAGIC_DISCONNECT => Some(Self::DisconnectInterlink(DisconnectInterlink::from_bytes(
+                bytes,
+            )?)),
+            _ => None,
+        }
+    }
+}
+
+define_message!(Voice, 54, 54, MAGIC_VOICE);
+impl_stream_id!(Voice, 4);
+impl_link_setup!(Voice, 6);
+impl_frame_number!(Voice, 34);
+impl_payload!(Voice, 36, 52);
+impl_trailing_crc_verify!(Voice);
+
+define_message!(VoiceHeader, 36, 36, MAGIC_VOICE_HEADER);
+impl_stream_id!(VoiceHeader, 4);
+impl_link_setup!(VoiceHeader, 6);
+impl_trailing_crc_verify!(VoiceHeader);
+
+define_message!(VoiceData, 26, 26, MAGIC_VOICE_DATA);
+impl_stream_id!(VoiceData, 4);
+impl_frame_number!(VoiceData, 6);
+impl_payload!(VoiceData, 8, 24);
+impl_trailing_crc_verify!(VoiceData);
+
+define_message!(Packet, 859, 38, MAGIC_PACKET);
+impl_link_setup_frame!(Packet, 4);
+
+impl Packet {
+    pub fn payload(&self) -> &[u8] {
+        &self.0[34..self.1]
+    }
+
+    pub fn set_payload(&mut self, bytes: &[u8]) {
+        let end = 34 + bytes.len();
+        self.0[34..end].copy_from_slice(bytes);
+        self.1 = end;
+    }
+
+    pub fn verify_integrity(&self) -> bool {
+        self.link_setup_frame().check_crc() == 0
+            && self.payload().len() >= 4
+            && crate::crc::m17_crc(self.payload()) == 0
+    }
+
+    pub fn recalculate_crc(&mut self) {
+        // LSF and payload should be confirmed valid before construction
+    }
+}
+
+define_message!(Pong, 10, 10, MAGIC_PONG);
+impl_address!(Pong, 4);
+no_crc!(Pong);
+
+define_message!(Connect, 11, 11, MAGIC_CONNECT);
+impl_address!(Connect, 4);
+impl_module!(Connect, 10);
+no_crc!(Connect);
+
+define_message!(Listen, 11, 11, MAGIC_LISTEN);
+impl_address!(Listen, 4);
+impl_module!(Listen, 10);
+no_crc!(Listen);
+
+define_message!(Disconnect, 10, 10, MAGIC_DISCONNECT);
+impl_address!(Disconnect, 4);
+no_crc!(Disconnect);
+
+define_message!(Ping, 10, 10, MAGIC_PING);
+impl_address!(Ping, 4);
+no_crc!(Ping);
+
+define_message!(DisconnectAcknowledge, 4, 4, MAGIC_DISCONNECT);
+no_crc!(DisconnectAcknowledge);
+
+define_message!(ForceDisconnect, 10, 10, MAGIC_DISCONNECT);
+impl_address!(ForceDisconnect, 4);
+no_crc!(ForceDisconnect);
+
+define_message!(ConnectAcknowledge, 4, 4, MAGIC_ACKNOWLEDGE);
+no_crc!(ConnectAcknowledge);
+
+define_message!(ConnectNack, 4, 4, MAGIC_NACK);
+no_crc!(ConnectNack);
+
+define_message!(VoiceInterlink, 55, 55, MAGIC_VOICE);
+impl_stream_id!(VoiceInterlink, 4);
+impl_link_setup!(VoiceInterlink, 6);
+impl_frame_number!(VoiceInterlink, 34);
+impl_payload!(VoiceInterlink, 36, 52);
+impl_internal_crc!(VoiceInterlink, 0, 54);
+impl_is_relayed!(VoiceInterlink);
+
+define_message!(VoiceHeaderInterlink, 37, 37, MAGIC_VOICE_HEADER);
+impl_stream_id!(VoiceHeaderInterlink, 4);
+impl_link_setup!(VoiceHeaderInterlink, 6);
+impl_internal_crc!(VoiceHeaderInterlink, 0, 36);
+impl_is_relayed!(VoiceHeaderInterlink);
+
+define_message!(VoiceDataInterlink, 27, 27, MAGIC_VOICE_DATA);
+impl_stream_id!(VoiceDataInterlink, 4);
+impl_frame_number!(VoiceDataInterlink, 6);
+impl_payload!(VoiceDataInterlink, 8, 24);
+impl_internal_crc!(VoiceDataInterlink, 0, 24);
+impl_is_relayed!(VoiceDataInterlink);
+
+define_message!(PacketInterlink, 860, 39, MAGIC_PACKET);
+impl_link_setup_frame!(PacketInterlink, 4);
+impl_is_relayed!(PacketInterlink);
+
+impl PacketInterlink {
+    pub fn payload(&self) -> &[u8] {
+        &self.0[34..(self.1 - 1)]
+    }
+
+    pub fn set_payload(&mut self, bytes: &[u8]) {
+        let is_relayed = self.is_relayed();
+        let end = 34 + bytes.len();
+        self.0[34..end].copy_from_slice(bytes);
+        self.1 = end + 1;
+        self.set_relayed(is_relayed);
+    }
+
+    pub fn verify_integrity(&self) -> bool {
+        self.link_setup_frame().check_crc() == 0
+            && self.payload().len() >= 4
+            && crate::crc::m17_crc(self.payload()) == 0
+    }
+
+    pub fn recalculate_crc(&mut self) {
+        // LSF and payload should be confirmed valid before construction
+    }
+}
+
+define_message!(ConnectInterlink, 37, 37, MAGIC_CONNECT);
+impl_address!(ConnectInterlink, 4);
+impl_modules!(ConnectInterlink, 10, 37);
+no_crc!(ConnectInterlink);
+
+define_message!(ConnectInterlinkAcknowledge, 37, 37, MAGIC_ACKNOWLEDGE);
+impl_address!(ConnectInterlinkAcknowledge, 4);
+impl_modules!(ConnectInterlinkAcknowledge, 10, 37);
+no_crc!(ConnectInterlinkAcknowledge);
+
+define_message!(DisconnectInterlink, 10, 10, MAGIC_DISCONNECT);
+impl_address!(DisconnectInterlink, 4);
+no_crc!(DisconnectInterlink);