feat(*) IPv6 support

This commit is contained in:
Datong Sun
2022-04-16 01:41:19 -07:00
parent 74183071f1
commit 85555f2a34
6 changed files with 351 additions and 139 deletions

View File

@@ -1,45 +1,85 @@
use bytes::{Bytes, BytesMut};
use internet_checksum::Checksum;
use pnet::packet::Packet;
use pnet::packet::{ip, ipv4, tcp};
use pnet::packet::{ip, ipv4, ipv6, tcp};
use std::convert::TryInto;
use std::net::SocketAddrV4;
use std::net::{IpAddr, SocketAddr};
const IPV4_HEADER_LEN: usize = 20;
const IPV6_HEADER_LEN: usize = 40;
const TCP_HEADER_LEN: usize = 20;
pub const MAX_PACKET_LEN: usize = 1500;
pub enum IPPacket<'p> {
V4(ipv4::Ipv4Packet<'p>),
V6(ipv6::Ipv6Packet<'p>),
}
impl<'a> IPPacket<'a> {
pub fn get_source(&self) -> IpAddr {
match self {
IPPacket::V4(p) => IpAddr::V4(p.get_source()),
IPPacket::V6(p) => IpAddr::V6(p.get_source()),
}
}
pub fn get_destination(&self) -> IpAddr {
match self {
IPPacket::V4(p) => IpAddr::V4(p.get_destination()),
IPPacket::V6(p) => IpAddr::V6(p.get_destination()),
}
}
}
pub fn build_tcp_packet(
local_addr: SocketAddrV4,
remote_addr: SocketAddrV4,
local_addr: SocketAddr,
remote_addr: SocketAddr,
seq: u32,
ack: u32,
flags: u16,
payload: Option<&[u8]>,
) -> Bytes {
let ip_header_len = match local_addr {
SocketAddr::V4(_) => IPV4_HEADER_LEN,
SocketAddr::V6(_) => IPV6_HEADER_LEN,
};
let wscale = (flags & tcp::TcpFlags::SYN) != 0;
let tcp_header_len = TCP_HEADER_LEN + if wscale { 4 } else { 0 }; // nop + wscale
let tcp_total_len = tcp_header_len + payload.map_or(0, |payload| payload.len());
let total_len = IPV4_HEADER_LEN + tcp_total_len;
let total_len = ip_header_len + tcp_total_len;
let mut buf = BytesMut::with_capacity(total_len);
buf.resize(total_len, 0);
let mut v4_buf = buf.split_to(IPV4_HEADER_LEN);
let mut ip_buf = buf.split_to(ip_header_len);
let mut tcp_buf = buf.split_to(tcp_total_len);
assert_eq!(0, buf.len());
let mut v4 = ipv4::MutableIpv4Packet::new(&mut v4_buf).unwrap();
v4.set_version(4);
v4.set_header_length(IPV4_HEADER_LEN as u8 / 4);
v4.set_next_level_protocol(ip::IpNextHeaderProtocols::Tcp);
v4.set_ttl(64);
v4.set_source(*local_addr.ip());
v4.set_destination(*remote_addr.ip());
v4.set_total_length(total_len.try_into().unwrap());
v4.set_flags(ipv4::Ipv4Flags::DontFragment);
let mut cksm = Checksum::new();
cksm.add_bytes(v4.packet());
v4.set_checksum(u16::from_be_bytes(cksm.checksum()));
match (local_addr, remote_addr) {
(SocketAddr::V4(local), SocketAddr::V4(remote)) => {
let mut v4 = ipv4::MutableIpv4Packet::new(&mut ip_buf).unwrap();
v4.set_version(4);
v4.set_header_length(IPV4_HEADER_LEN as u8 / 4);
v4.set_next_level_protocol(ip::IpNextHeaderProtocols::Tcp);
v4.set_ttl(64);
v4.set_source(*local.ip());
v4.set_destination(*remote.ip());
v4.set_total_length(total_len.try_into().unwrap());
v4.set_flags(ipv4::Ipv4Flags::DontFragment);
let mut cksm = Checksum::new();
cksm.add_bytes(v4.packet());
v4.set_checksum(u16::from_be_bytes(cksm.checksum()));
}
(SocketAddr::V6(local), SocketAddr::V6(remote)) => {
let mut v6 = ipv6::MutableIpv6Packet::new(&mut ip_buf).unwrap();
v6.set_version(6);
v6.set_payload_length(tcp_total_len.try_into().unwrap());
v6.set_next_header(ip::IpNextHeaderProtocols::Tcp);
v6.set_hop_limit(64);
v6.set_source(*local.ip());
v6.set_destination(*remote.ip());
}
_ => unreachable!(),
};
let mut tcp = tcp::MutableTcpPacket::new(&mut tcp_buf).unwrap();
tcp.set_window(0xffff);
@@ -59,24 +99,55 @@ pub fn build_tcp_packet(
}
let mut cksm = Checksum::new();
cksm.add_bytes(&local_addr.ip().octets());
cksm.add_bytes(&remote_addr.ip().octets());
let ip::IpNextHeaderProtocol(tcp_protocol) = ip::IpNextHeaderProtocols::Tcp;
let mut pseudo = [0u8, tcp_protocol, 0, 0];
pseudo[2..].copy_from_slice(&(tcp_total_len as u16).to_be_bytes());
cksm.add_bytes(&pseudo);
match (local_addr, remote_addr) {
(SocketAddr::V4(local), SocketAddr::V4(remote)) => {
cksm.add_bytes(&local.ip().octets());
cksm.add_bytes(&remote.ip().octets());
let mut pseudo = [0u8, tcp_protocol, 0, 0];
pseudo[2..].copy_from_slice(&(tcp_total_len as u16).to_be_bytes());
cksm.add_bytes(&pseudo);
}
(SocketAddr::V6(local), SocketAddr::V6(remote)) => {
cksm.add_bytes(&local.ip().octets());
cksm.add_bytes(&remote.ip().octets());
let mut pseudo = [0u8, 0, 0, 0, 0, 0, 0, tcp_protocol];
pseudo[0..4].copy_from_slice(&(tcp_total_len as u32).to_be_bytes());
cksm.add_bytes(&pseudo);
}
_ => unreachable!(),
};
cksm.add_bytes(tcp.packet());
tcp.set_checksum(u16::from_be_bytes(cksm.checksum()));
v4_buf.unsplit(tcp_buf);
v4_buf.freeze()
ip_buf.unsplit(tcp_buf);
ip_buf.freeze()
}
pub fn parse_ipv4_packet(buf: &Bytes) -> (ipv4::Ipv4Packet, tcp::TcpPacket) {
let v4 = ipv4::Ipv4Packet::new(buf).unwrap();
let tcp = tcp::TcpPacket::new(&buf[IPV4_HEADER_LEN..]).unwrap();
pub fn parse_ip_packet(buf: &Bytes) -> Option<(IPPacket, tcp::TcpPacket)> {
if buf[0] >> 4 == 4 {
let v4 = ipv4::Ipv4Packet::new(buf).unwrap();
if v4.get_next_level_protocol() != ip::IpNextHeaderProtocols::Tcp {
return None;
}
(v4, tcp)
let tcp = tcp::TcpPacket::new(&buf[IPV4_HEADER_LEN..]).unwrap();
Some((IPPacket::V4(v4), tcp))
} else if buf[0] >> 4 == 6 {
let v6 = ipv6::Ipv6Packet::new(buf).unwrap();
if v6.get_next_header() != ip::IpNextHeaderProtocols::Tcp {
return None;
}
let tcp = tcp::TcpPacket::new(&buf[IPV6_HEADER_LEN..]).unwrap();
Some((IPPacket::V6(v6), tcp))
} else {
None
}
}
#[cfg(all(test, feature = "benchmark"))]