[feature] Support GREv0/GREv1 Decode

5 files changed, 527 insertions, 1 deletions

diff --git a/src/protocol/ethernet.rs b/src/protocol/ethernet.rs
index a588c0d..6c42c2d 100644
--- a/src/protocol/ethernet.rs
+++ b/src/protocol/ethernet.rs
@@ -25,6 +25,7 @@ pub enum EtherType {
     IPX,            // IPX [Xerox]
     Qnet,           // QNX Qnet [QNX Software Systems]
     IPv6,           // Internet Protocol Version 6 (IPv6) [RFC7042]
+    PPP,            // Point-to-Point Protocol (PPP) [RFC7042]
     FlowControl,    // Ethernet Flow Control [IEEE 802.3x]
     CobraNet,       // CobraNet [CobraNet]
     MPLSuni,        // MPLS Unicast [RFC 3032]
@@ -88,6 +89,7 @@ impl From<u16> for EtherType {
             0x8137 => Self::IPX,
             0x8204 => Self::Qnet,
             0x86DD => Self::IPv6,
+            0x880b => Self::PPP,
             0x8808 => Self::FlowControl,
             0x8819 => Self::CobraNet,
             0x8847 => Self::MPLSuni,
diff --git a/src/protocol/grev0.rs b/src/protocol/grev0.rs
new file mode 100644
index 0000000..fd368b9
--- /dev/null
+++ b/src/protocol/grev0.rs
@@ -0,0 +1,334 @@
+use crate::protocol::codec::Decode;
+use crate::protocol::ethernet::EtherType;
+use nom::bits;
+use nom::bytes;
+use nom::error::Error;
+use nom::number;
+use nom::sequence;
+use nom::IResult;
+
+/******************************************************************************
+ * Struct
+ ******************************************************************************/
+
+/*
+ * GRE Header Format (Version 0)
+ *
+ *   0                   1                   2                   3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |C|R|K|S|s|Recur|  Flags  | Ver |         Protocol Type         |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |      Checksum (optional)      |       Offset (optional)       |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                         Key (optional)                        |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                    Sequence Number (optional)                 |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                         Routing (optional)
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ *   0                   1                   2                   3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |       Address Family          |  SRE Offset   |  SRE Length   |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                        Routing Information ...
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * https://datatracker.ietf.org/doc/html/rfc1701
+ * https://datatracker.ietf.org/doc/html/rfc2890
+ */
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct SourceRouteEntry {
+    pub address_family: u16,
+    pub sre_offset: u8,
+    pub sre_length: u8,
+    pub sre_routing: Vec<u8>,
+}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Grev0Header {
+    pub flag_checksum: bool,
+    pub flag_routing: bool,
+    pub flag_key: bool,
+    pub flag_sequence: bool,
+    pub flag_strictroute: bool,
+    pub recursion_control: u8,
+    pub flags: u8,
+    pub version: u8,
+    pub protocol_type: EtherType,
+    pub checksum: Option<u16>,
+    pub offset: Option<u16>,
+    pub key: Option<u32>,
+    pub sequence_number: Option<u32>,
+    pub routing: Option<Vec<SourceRouteEntry>>,
+}
+
+/******************************************************************************
+ * API
+ ******************************************************************************/
+
+fn source_route_entry_decode(input: &[u8]) -> IResult<&[u8], SourceRouteEntry> {
+    let (input, address_family) = number::streaming::be_u16(input)?;
+    let (input, sre_offset) = number::streaming::be_u8(input)?;
+    let (input, sre_length) = number::streaming::be_u8(input)?;
+    /*
+     * The routing field is terminated with a "NULL" SRE containing an
+     * address family of type 0x0000 and a length of 0.
+     */
+    let (input, sre_routing) = match (address_family, sre_length) {
+        (_, 0) => (input, vec![]),
+        (_, _) => bytes::streaming::take(sre_length)(input).map(|(i, l)| (i, l.to_vec()))?,
+    };
+    Ok((
+        input,
+        SourceRouteEntry {
+            address_family,
+            sre_offset,
+            sre_length,
+            sre_routing,
+        },
+    ))
+}
+
+impl Decode for Grev0Header {
+    type Iterm = Grev0Header;
+    fn decode(input: &[u8]) -> IResult<&[u8], Grev0Header> {
+        let (
+            input,
+            (
+                flag_checksum,
+                flag_routing,
+                flag_key,
+                flag_sequence,
+                flag_strictroute,
+                recursion_control,
+                flags,
+                version,
+            ),
+        ): (&[u8], (u8, u8, u8, u8, u8, u8, u8, u8)) =
+            bits::bits::<_, _, Error<_>, _, _>(sequence::tuple((
+                bits::streaming::take(1u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(3u8),
+                bits::streaming::take(5u8),
+                bits::streaming::take(3u8),
+            )))(input)?;
+        if version != 0 {
+            return Err(nom::Err::Error(Error::new(
+                input,
+                nom::error::ErrorKind::Verify,
+            )));
+        }
+
+        let (input, protocol_type) = EtherType::decode(input)?;
+        let (input, checksum) = match (flag_checksum, flag_routing) {
+            (0, 0) => (input, None),
+            (_, _) => number::streaming::be_u16(input).map(|(i, l)| (i, Some(l)))?,
+        };
+        let (input, offset) = match (flag_checksum, flag_routing) {
+            (0, 0) => (input, None),
+            (_, _) => number::streaming::be_u16(input).map(|(i, l)| (i, Some(l)))?,
+        };
+        let (input, key) = match flag_key {
+            0 => (input, None),
+            _ => number::streaming::be_u32(input).map(|(i, l)| (i, Some(l)))?,
+        };
+        let (input, sequence_number) = match flag_sequence {
+            0 => (input, None),
+            _ => number::streaming::be_u32(input).map(|(i, l)| (i, Some(l)))?,
+        };
+        let (input, routing) = match flag_routing {
+            0 => (input, None),
+            _ => {
+                let mut left = input;
+                let mut routing = Vec::new();
+                loop {
+                    let (i, sre) = source_route_entry_decode(left)?;
+                    let length = sre.sre_length;
+                    routing.push(sre);
+                    left = i;
+                    if length == 0 {
+                        break;
+                    }
+                }
+                (left, Some(routing))
+            }
+        };
+
+        Ok((
+            input,
+            Grev0Header {
+                flag_checksum: flag_checksum == 1,
+                flag_routing: flag_routing == 1,
+                flag_key: flag_key == 1,
+                flag_sequence: flag_sequence == 1,
+                flag_strictroute: flag_strictroute == 1,
+                recursion_control,
+                flags,
+                version,
+                protocol_type,
+                checksum,
+                offset,
+                key,
+                sequence_number,
+                routing,
+            },
+        ))
+    }
+}
+
+/******************************************************************************
+ * TEST
+ ******************************************************************************/
+
+#[cfg(test)]
+mod tests {
+    use super::Grev0Header;
+    use super::SourceRouteEntry;
+    use crate::protocol::codec::Decode;
+    use crate::protocol::ethernet::EtherType;
+    const LAST_SLICE: &'static [u8] = &[0xff];
+
+    #[test]
+    // Enable Key Bit
+    fn grev0_header_decode1() {
+        /*
+         * Generic Routing Encapsulation (IP)
+         *     Flags and Version: 0x2000
+         *         0... .... .... .... = Checksum Bit: No
+         *         .0.. .... .... .... = Routing Bit: No
+         *         ..1. .... .... .... = Key Bit: Yes
+         *         ...0 .... .... .... = Sequence Number Bit: No
+         *         .... 0... .... .... = Strict Source Route Bit: No
+         *         .... .000 .... .... = Recursion control: 0
+         *         .... .... 0000 0... = Flags (Reserved): 0
+         *         .... .... .... .000 = Version: GRE (0)
+         *     Protocol Type: IP (0x0800)
+         *     Key: 0x00000384
+         */
+
+        let bytes = [
+            0x20, 0x00, 0x08, 0x00, 0x00, 0x00, 0x03, 0x84, 0xff, /* Payload */
+        ];
+
+        let expectation = Grev0Header {
+            flag_checksum: false,
+            flag_routing: false,
+            flag_key: true,
+            flag_sequence: false,
+            flag_strictroute: false,
+            recursion_control: 0,
+            flags: 0,
+            version: 0,
+            protocol_type: EtherType::IPv4,
+            checksum: None,
+            offset: None,
+            key: Some(0x384),
+            sequence_number: None,
+            routing: None,
+        };
+
+        assert_eq!(Grev0Header::decode(&bytes), Ok((LAST_SLICE, expectation)));
+
+        // example
+        let result = Grev0Header::decode(&bytes);
+        if let Ok((payload, header)) = result {
+            println!("return: {:?}, payload: {}", header, payload.len());
+        } else {
+            println!("return: Incomplete data");
+        }
+    }
+
+    #[test]
+    // Enable Routing Bit
+    fn grev0_header_decode2() {
+        /*
+         * Generic Routing Encapsulation (IP)
+         *     Flags and Version: 0xc000
+         *         1... .... .... .... = Checksum Bit: Yes
+         *         .1.. .... .... .... = Routing Bit: Yes
+         *         ..0. .... .... .... = Key Bit: No
+         *         ...0 .... .... .... = Sequence Number Bit: No
+         *         .... 0... .... .... = Strict Source Route Bit: No
+         *         .... .000 .... .... = Recursion control: 0
+         *         .... .... 0000 0... = Flags (Reserved): 0
+         *         .... .... .... .000 = Version: GRE (0)
+         *     Protocol Type: IP (0x0800)
+         *     Checksum: 0x0000 incorrect, should be 0xea95
+         *         [Expert Info (Warning/Protocol): Incorrect GRE Checksum [should be 0xea95]]
+         *             [Incorrect GRE Checksum [should be 0xea95]]
+         *             [Severity level: Warning]
+         *             [Group: Protocol]
+         *     [Checksum Status: Bad]
+         *     Offset: 44
+         *     Routing
+         *     Address Family: 2
+         *     SRE Offset: 0
+         *     SRE Length: 44
+         *     Routing Information: 6c696e6b5f696e666f206c696e6b5f696e666f206c696e6b5f696e666f206c696e6b5f69…
+         *     Routing
+         *     Address Family: 0
+         *     SRE Offset: 0
+         *     SRE Length: 0
+         */
+
+        let bytes = [
+            0xc0, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x2c, 0x00, 0x02, 0x00, 0x2c, 0x6c, 0x69,
+            0x6e, 0x6b, 0x5f, 0x69, 0x6e, 0x66, 0x6f, 0x20, 0x6c, 0x69, 0x6e, 0x6b, 0x5f, 0x69,
+            0x6e, 0x66, 0x6f, 0x20, 0x6c, 0x69, 0x6e, 0x6b, 0x5f, 0x69, 0x6e, 0x66, 0x6f, 0x20,
+            0x6c, 0x69, 0x6e, 0x6b, 0x5f, 0x69, 0x6e, 0x66, 0x6f, 0x20, 0x00, 0x00, 0x00, 0x00,
+            0x00, 0x00, 0x00, 0x00, 0xff, /* Payload */
+        ];
+
+        let expectation = Grev0Header {
+            flag_checksum: true,
+            flag_routing: true,
+            flag_key: false,
+            flag_sequence: false,
+            flag_strictroute: false,
+            recursion_control: 0,
+            flags: 0,
+            version: 0,
+            protocol_type: EtherType::IPv4,
+            checksum: Some(0x0000),
+            offset: Some(44),
+            key: None,
+            sequence_number: None,
+            routing: Some(vec![
+                SourceRouteEntry {
+                    address_family: 2,
+                    sre_offset: 0,
+                    sre_length: 44,
+                    sre_routing: vec![
+                        0x6c, 0x69, 0x6e, 0x6b, 0x5f, 0x69, 0x6e, 0x66, 0x6f, 0x20, 0x6c, 0x69,
+                        0x6e, 0x6b, 0x5f, 0x69, 0x6e, 0x66, 0x6f, 0x20, 0x6c, 0x69, 0x6e, 0x6b,
+                        0x5f, 0x69, 0x6e, 0x66, 0x6f, 0x20, 0x6c, 0x69, 0x6e, 0x6b, 0x5f, 0x69,
+                        0x6e, 0x66, 0x6f, 0x20, 0x00, 0x00, 0x00, 0x00,
+                    ],
+                },
+                SourceRouteEntry {
+                    address_family: 0,
+                    sre_offset: 0,
+                    sre_length: 0,
+                    sre_routing: vec![],
+                },
+            ]),
+        };
+
+        assert_eq!(Grev0Header::decode(&bytes), Ok((LAST_SLICE, expectation)));
+
+        // example
+        let result = Grev0Header::decode(&bytes);
+        if let Ok((payload, header)) = result {
+            println!("return: {:?}, payload: {}", header, payload.len());
+        } else {
+            println!("return: Incomplete data");
+        }
+    }
+}
diff --git a/src/protocol/grev1.rs b/src/protocol/grev1.rs
new file mode 100644
index 0000000..4bf551f
--- /dev/null
+++ b/src/protocol/grev1.rs
@@ -0,0 +1,186 @@
+use crate::protocol::codec::Decode;
+use crate::protocol::ethernet::EtherType;
+use nom::bits;
+use nom::error::Error;
+use nom::number;
+use nom::sequence;
+use nom::IResult;
+
+/******************************************************************************
+ * Struct
+ ******************************************************************************/
+
+/*
+ * Enhanced GRE header (Version 1)
+ *
+ *   0                   1                   2                   3
+ *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |C|R|K|S|s|Recur|A| Flags | Ver |         Protocol Type         |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |    Key (HW) Payload Length    |       Key (LW) Call ID        |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |                  Sequence Number (Optional)                   |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *  |               Acknowledgment Number (Optional)                |
+ *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ *
+ * https://datatracker.ietf.org/doc/html/rfc2637
+ */
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub struct Grev1Header {
+    pub flag_checksum: bool,
+    pub flag_routing: bool,
+    pub flag_key: bool,
+    pub flag_sequence: bool,
+    pub flag_strictroute: bool,
+    pub recursion_control: u8,
+    pub flag_acknowledgment: bool,
+    pub flags: u8,
+    pub version: u8,
+    pub protocol_type: EtherType,
+    pub key_payload_length: u16,
+    pub key_call_id: u16,
+    pub sequence_number: Option<u32>,
+    pub acknowledgment_number: Option<u32>,
+}
+
+/******************************************************************************
+ * API
+ ******************************************************************************/
+
+impl Decode for Grev1Header {
+    type Iterm = Grev1Header;
+    fn decode(input: &[u8]) -> IResult<&[u8], Grev1Header> {
+        let (
+            input,
+            (
+                flag_checksum,
+                flag_routing,
+                flag_key,
+                flag_sequence,
+                flag_strictroute,
+                recursion_control,
+                flag_acknowledgment,
+                flags,
+                version,
+            ),
+        ): (&[u8], (u8, u8, u8, u8, u8, u8, u8, u8, u8)) =
+            bits::bits::<_, _, Error<_>, _, _>(sequence::tuple((
+                bits::streaming::take(1u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(3u8),
+                bits::streaming::take(1u8),
+                bits::streaming::take(4u8),
+                bits::streaming::take(3u8),
+            )))(input)?;
+        if version != 1 {
+            return Err(nom::Err::Error(Error::new(
+                input,
+                nom::error::ErrorKind::Verify,
+            )));
+        }
+
+        let (input, protocol_type) = EtherType::decode(input)?;
+        let (input, key_payload_length) = number::streaming::be_u16(input)?;
+        let (input, key_call_id) = number::streaming::be_u16(input)?;
+        let (input, sequence_number) = match flag_sequence {
+            0 => (input, None),
+            _ => number::streaming::be_u32(input).map(|(i, l)| (i, Some(l)))?,
+        };
+        let (input, acknowledgment_number) = match flag_acknowledgment {
+            0 => (input, None),
+            _ => number::streaming::be_u32(input).map(|(i, l)| (i, Some(l)))?,
+        };
+
+        Ok((
+            input,
+            Grev1Header {
+                flag_checksum: flag_checksum == 1,
+                flag_routing: flag_routing == 1,
+                flag_key: flag_key == 1,
+                flag_sequence: flag_sequence == 1,
+                flag_strictroute: flag_strictroute == 1,
+                recursion_control,
+                flag_acknowledgment: flag_acknowledgment == 1,
+                flags,
+                version,
+                protocol_type,
+                key_payload_length,
+                key_call_id,
+                sequence_number,
+                acknowledgment_number,
+            },
+        ))
+    }
+}
+
+/******************************************************************************
+ * TEST
+ ******************************************************************************/
+
+#[cfg(test)]
+mod tests {
+    use super::Grev1Header;
+    use crate::protocol::codec::Decode;
+    use crate::protocol::ethernet::EtherType;
+    const LAST_SLICE: &'static [u8] = &[0xff];
+
+    #[test]
+    fn grev1_header_decode() {
+        /*
+         * Generic Routing Encapsulation (PPP)
+         *     Flags and Version: 0x3081
+         *         0... .... .... .... = Checksum Bit: No
+         *         .0.. .... .... .... = Routing Bit: No
+         *         ..1. .... .... .... = Key Bit: Yes
+         *         ...1 .... .... .... = Sequence Number Bit: Yes
+         *         .... 0... .... .... = Strict Source Route Bit: No
+         *         .... .000 .... .... = Recursion control: 0
+         *         .... .... 1... .... = Acknowledgment: Yes
+         *         .... .... .000 0... = Flags (Reserved): 0
+         *         .... .... .... .001 = Version: Enhanced GRE (1)
+         *     Protocol Type: PPP (0x880b)
+         *     Payload Length: 103
+         *     Call ID: 6016
+         *     Sequence Number: 430001
+         *     Acknowledgment Number: 539254
+         */
+
+        let bytes = [
+            0x30, 0x81, 0x88, 0x0b, 0x00, 0x67, 0x17, 0x80, 0x00, 0x06, 0x8f, 0xb1, 0x00, 0x08,
+            0x3a, 0x76, 0xff, /* Payload */
+        ];
+
+        let expectation = Grev1Header {
+            flag_checksum: false,
+            flag_routing: false,
+            flag_key: true,
+            flag_sequence: true,
+            flag_strictroute: false,
+            recursion_control: 0,
+            flag_acknowledgment: true,
+            flags: 0,
+            version: 1,
+            protocol_type: EtherType::PPP,
+            key_payload_length: 103,
+            key_call_id: 6016,
+            sequence_number: Some(430001),
+            acknowledgment_number: Some(539254),
+        };
+
+        assert_eq!(Grev1Header::decode(&bytes), Ok((LAST_SLICE, expectation)));
+
+        // example
+        let result = Grev1Header::decode(&bytes);
+        if let Ok((payload, header)) = result {
+            println!("return: {:?}, payload: {}", header, payload.len());
+        } else {
+            println!("return: Incomplete data");
+        }
+    }
+}
diff --git a/src/protocol/ip.rs b/src/protocol/ip.rs
index c9b4f53..1ff15e3 100644
--- a/src/protocol/ip.rs
+++ b/src/protocol/ip.rs
@@ -29,6 +29,7 @@ pub enum IPProtocol {
     IPV6,
     IPV6ROUTING,
     IPV6FRAGMENT,
+    GRE,
     ESP,
     AUTH,
     ICMP6,
@@ -64,6 +65,7 @@ impl From<u8> for IPProtocol {
             41 => IPProtocol::IPV6,
             43 => IPProtocol::IPV6ROUTING,  // IPv6 Routing Header
             44 => IPProtocol::IPV6FRAGMENT, // IPv6 Fragment Header
+            47 => IPProtocol::GRE,          // GRE encapsulation [RFC2784][RFC2890]
             50 => IPProtocol::ESP,          // Encap Security Payload [RFC4303]
             51 => IPProtocol::AUTH,         // Authentication Header [RFC4302]
             58 => IPProtocol::ICMP6,
diff --git a/src/protocol/mod.rs b/src/protocol/mod.rs
index 7c8ade2..4f82280 100644
--- a/src/protocol/mod.rs
+++ b/src/protocol/mod.rs
@@ -12,4 +12,6 @@ pub mod icmp;
 pub mod icmpv6;
 pub mod mpls;
 pub mod gtpv1;
-pub mod l2tp;
\ No newline at end of file
+pub mod l2tp;
+pub mod grev0;
+pub mod grev1;
\ No newline at end of file