fix: the panic caused by parsing icmp6

Author: yuanchaoa

agent/crates/public/src/enums.rs

@@ -246,6 +246,7 @@ pub enum HeaderType {
     Ipv4 = 0x20,
     Ipv4Icmp = 0x21,
     Ipv6 = 0x40,
+    Ipv6Icmp = 0x41,
     Ipv4Tcp = 0x80,
     Ipv4Udp = 0x81,
     Ipv6Tcp = 0xb0,
@@ -267,8 +268,9 @@ impl HeaderType {
             Self::Ipv4 => 14 + 20,         // 不包括DOT1Q + IPv4 option0,
             Self::Ipv4Icmp => 14 + 20 + 8, // 不包括DOT1Q + IPv4 option 0x21,
             Self::Ipv6 => 14 + 20, // 不包括DOT1Q + IPv6 option，IPv6大于IPv4的20个字节计算在m.l2L3OptSize里面0,
+            Self::Ipv6Icmp => 14 + 20 + 8, // 不包括DOT1Q + IPv6 option，IPv6大于IPv4的20个字节计算在m.l2L3OptSize里面0,
             Self::Ipv4Tcp => 14 + 20 + 20, // 不包括DOT1Q + IPv4 option0x80,
-            Self::Ipv4Udp => 14 + 20 + 8, // 不包括DOT1Q + IPv4 option0x81,
+            Self::Ipv4Udp => 14 + 20 + 8,  // 不包括DOT1Q + IPv4 option0x81,
             Self::Ipv6Tcp => 14 + 40 + 20, // 不包括DOT1Q + IPv6 option，IPv6大于40字节的option计算在m.l2L3OptSize里面0xb0,
             Self::Ipv6Udp => 14 + 40 + 8, // 不包括DOT1Q + IPv6 option，IPv6大于40字节的option计算在m.l2L3OptSize里面0xb1,
             Self::Invalid => unreachable!(),
@@ -282,6 +284,7 @@ impl HeaderType {
             Self::Ipv4 => 20,
             Self::Ipv4Icmp => 8,
             Self::Ipv6 => 20,
+            Self::Ipv6Icmp => 8,
             Self::Ipv4Tcp => 20,
             Self::Ipv4Udp => 8,
             Self::Ipv6Tcp => 20,

agent/src/common/meta_packet.rs

@@ -940,33 +940,35 @@ impl<'a> MetaPacket<'a> {
                 }
             }
             IpProtocol::ICMPV6 => {
+                size_checker -= HeaderType::Ipv6Icmp.min_header_size() as isize;
+                if size_checker < 0 {
+                    return Ok(());
+                }
                 let mut icmp_data = IcmpData::default();
-                if size_checker > 0 {
-                    let icmpv6_type_index = ICMPV6_TYPE_OFFSET + self.l2_l3_opt_size as usize;
-                    icmp_data.icmp_type = packet[icmpv6_type_index];
-
-                    match Icmpv6Type::new(packet[icmpv6_type_index]) {
-                        Icmpv6Types::NeighborAdvert => {
-                            self.nd_reply_or_arp_request = true;
-                        }
-                        Icmpv6Types::EchoRequest => {
-                            icmp_data.echo_id_seq = read_u32_be(&packet[icmpv6_type_index + 4..]);
-                        }
-                        Icmpv6Types::EchoReply => {
-                            icmp_data.echo_id_seq = read_u32_be(&packet[icmpv6_type_index + 4..]);
-                            self.lookup_key.direction = PacketDirection::ServerToClient;
-                        }
-                        _ => {}
+                let icmpv6_type_index = ICMPV6_TYPE_OFFSET + self.l2_l3_opt_size as usize;
+                icmp_data.icmp_type = packet[icmpv6_type_index];
+                match Icmpv6Type::new(packet[icmpv6_type_index]) {
+                    Icmpv6Types::NeighborAdvert => {
+                        self.nd_reply_or_arp_request = true;
                     }
-                    // 忽略link-local address并只考虑ND reply, i.e. neighbour advertisement
-                    if let IpAddr::V6(ip) = self.lookup_key.src_ip {
-                        self.nd_reply_or_arp_request =
-                            self.nd_reply_or_arp_request && !is_unicast_link_local(&ip);
+                    Icmpv6Types::EchoRequest => {
+                        icmp_data.echo_id_seq = read_u32_be(&packet[icmpv6_type_index + 4..]);
                     }
+                    Icmpv6Types::EchoReply => {
+                        icmp_data.echo_id_seq = read_u32_be(&packet[icmpv6_type_index + 4..]);
+                        self.lookup_key.direction = PacketDirection::ServerToClient;
+                    }
+                    _ => {}
+                }
+                // 忽略link-local address并只考虑ND reply, i.e. neighbour advertisement
+                if let IpAddr::V6(ip) = self.lookup_key.src_ip {
+                    self.nd_reply_or_arp_request =
+                        self.nd_reply_or_arp_request && !is_unicast_link_local(&ip);
                 }
-                self.protocol_data = ProtocolData::IcmpData(icmp_data);
                 self.payload_len =
                     (self.packet_len - (packet.len() - size_checker as usize) as u32) as u16;
+                self.protocol_data = ProtocolData::IcmpData(icmp_data);
+                self.header_type = HeaderType::Ipv6Icmp;
                 return Ok(());
             }
             _ => {