netsim_embed_core/
packet.rs

1use libpacket::ip::IpNextHeaderProtocols;
2use libpacket::ipv4::{self, Ipv4Packet, MutableIpv4Packet};
3use libpacket::tcp::{self, MutableTcpPacket, TcpPacket};
4use libpacket::udp::{self, MutableUdpPacket, UdpPacket};
5use libpacket::{MutablePacket, Packet as _};
6use std::net::SocketAddrV4;
7
8#[derive(Clone, Copy, Debug)]
9pub enum Protocol {
10    Udp,
11    Tcp,
12}
13
14#[derive(Debug)]
15pub struct Packet<'a> {
16    protocol: Protocol,
17    bytes: &'a mut [u8],
18}
19
20impl<'a> Packet<'a> {
21    pub fn new(bytes: &'a mut [u8]) -> Option<Self> {
22        let packet = Ipv4Packet::new(bytes)?;
23        let protocol = match packet.get_next_level_protocol() {
24            IpNextHeaderProtocols::Udp => {
25                UdpPacket::new(packet.payload())?;
26                Protocol::Udp
27            }
28            IpNextHeaderProtocols::Tcp => {
29                TcpPacket::new(packet.payload())?;
30                Protocol::Tcp
31            }
32            _ => return None,
33        };
34        Some(Self { protocol, bytes })
35    }
36
37    pub fn get_source(&self) -> SocketAddrV4 {
38        let packet = Ipv4Packet::new(self.bytes).unwrap();
39        let ip = packet.get_source();
40        let port = match self.protocol {
41            Protocol::Udp => UdpPacket::new(packet.payload()).unwrap().get_source(),
42            Protocol::Tcp => TcpPacket::new(packet.payload()).unwrap().get_source(),
43        };
44        SocketAddrV4::new(ip, port)
45    }
46
47    pub fn get_destination(&self) -> SocketAddrV4 {
48        let packet = Ipv4Packet::new(self.bytes).unwrap();
49        let ip = packet.get_destination();
50        let port = match self.protocol {
51            Protocol::Udp => UdpPacket::new(packet.payload()).unwrap().get_destination(),
52            Protocol::Tcp => TcpPacket::new(packet.payload()).unwrap().get_destination(),
53        };
54        SocketAddrV4::new(ip, port)
55    }
56
57    pub fn get_ttl(&self) -> u8 {
58        Ipv4Packet::new(self.bytes).unwrap().get_ttl()
59    }
60
61    pub fn protocol(&self) -> Protocol {
62        self.protocol
63    }
64
65    pub fn set_source(&mut self, addr: SocketAddrV4) {
66        let mut packet = MutableIpv4Packet::new(self.bytes).unwrap();
67        packet.set_source(*addr.ip());
68        match self.protocol {
69            Protocol::Udp => {
70                let mut udp = MutableUdpPacket::new(packet.payload_mut()).unwrap();
71                udp.set_source(addr.port());
72            }
73            Protocol::Tcp => {
74                let mut tcp = MutableTcpPacket::new(packet.payload_mut()).unwrap();
75                tcp.set_source(addr.port());
76            }
77        }
78    }
79
80    pub fn set_destination(&mut self, addr: SocketAddrV4) {
81        let mut packet = MutableIpv4Packet::new(self.bytes).unwrap();
82        packet.set_destination(*addr.ip());
83        match self.protocol {
84            Protocol::Udp => {
85                let mut udp = MutableUdpPacket::new(packet.payload_mut()).unwrap();
86                udp.set_destination(addr.port());
87            }
88            Protocol::Tcp => {
89                let mut tcp = MutableTcpPacket::new(packet.payload_mut()).unwrap();
90                tcp.set_destination(addr.port());
91            }
92        }
93    }
94
95    pub fn set_ttl(&mut self, ttl: u8) {
96        MutableIpv4Packet::new(self.bytes).unwrap().set_ttl(ttl)
97    }
98
99    pub fn set_checksum(&mut self) {
100        let mut packet = MutableIpv4Packet::new(self.bytes).unwrap();
101        let source = packet.get_source();
102        let dest = packet.get_destination();
103        packet.set_checksum(ipv4::checksum(&packet.to_immutable()));
104        match self.protocol {
105            Protocol::Udp => {
106                let mut udp = MutableUdpPacket::new(packet.payload_mut()).unwrap();
107                udp.set_checksum(udp::ipv4_checksum(&udp.to_immutable(), &source, &dest));
108            }
109            Protocol::Tcp => {
110                let mut tcp = MutableTcpPacket::new(packet.payload_mut()).unwrap();
111                tcp.set_checksum(tcp::ipv4_checksum(&tcp.to_immutable(), &source, &dest));
112            }
113        }
114    }
115}
netsim_embed_core/packet.rs

netsim_embed_core/
packet.rs
