feat: add ICMP parser

Author: SkuldNorniern

src/net/parser/raw/protocols/icmp.rs

@@ -0,0 +1,74 @@
+use crate::net::parser::raw::protocols::ProtocolParser;
+use crate::net::parser::raw::RawProtocolHeader;
+
+pub struct IcmpParser;
+
+impl ProtocolParser for IcmpParser {
+    fn protocol_number() -> u8 {
+        1 // ICMP protocol number
+    }
+
+    fn parse_packet(payload: &[u8], _protocol_number: u8) -> Option<RawProtocolHeader> {
+        // ICMP header format:
+        // 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
+        // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+        // |     Type      |     Code      |          Checksum             |
+        // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+        // |                             Data                              |
+        // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+        if payload.len() < 4 {
+            return None;
+        }
+
+        let icmp_type = payload[0];
+        let icmp_code = payload[1];
+        // Checksum is at payload[2..4] but we don't validate it here
+
+        Some(
+            RawProtocolHeader::new(
+                None,
+                None,
+                icmp_type as u16, // Using type as src_port
+                icmp_code as u16, // Using code as dst_port
+                Self::protocol_number(),
+                payload.len() as u16,
+                if payload.len() > 4 {
+                    Some(payload[4..].to_vec())
+                } else {
+                    None
+                },
+            )
+            .with_raw_packet(payload.to_vec())
+            .with_flags(icmp_type)
+            .with_version(icmp_code),
+        )
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_icmp_parser() {
+        // Echo request (ping) packet
+        let payload = &[
+            8, // Type: Echo request
+            0, // Code: 0
+            0x00, 0x00, // Checksum (not validated in this test)
+            0x12, 0x34, // Identifier
+            0x56, 0x78, // Sequence number
+        ];
+
+        let result = IcmpParser::parse_packet(payload, IcmpParser::protocol_number());
+        assert!(result.is_some());
+
+        let header = result.unwrap();
+        assert_eq!(header.src_port, 8); // Echo request type
+        assert_eq!(header.dst_port, 0); // Code 0
+        assert_eq!(header.protocol, 1); // ICMP protocol
+        assert_eq!(header.length, payload.len() as u16);
+    }
+}