ipblc/src/fw.rs
2023-01-08 21:16:20 +01:00

105 lines
3.0 KiB
Rust

use crate::ip::IpData;
use crate::ipblc::PKG_NAME;
use nftnl::{nft_expr, Batch, Chain, FinalizedBatch, ProtoFamily, Rule, Table};
use std::{ffi::CString, io::Error, net::Ipv4Addr};
pub fn fwinit() -> (Batch, Table) {
let mut batch = Batch::new();
let table = Table::new(&CString::new(PKG_NAME).unwrap(), ProtoFamily::Ipv4);
batch.add(&table, nftnl::MsgType::Add);
batch.add(&table, nftnl::MsgType::Del);
batch.add(&table, nftnl::MsgType::Add);
(batch, table)
}
pub fn fwblock(
ips_add: &Vec<IpData>,
ret: &mut Vec<String>,
fwlen: &mut usize,
) -> std::result::Result<(), Error> {
// convert chain
let ips_add = convert(ips_add);
let (mut batch, table) = fwinit();
// build chain
let mut chain = Chain::new(&CString::new(PKG_NAME).unwrap(), &table);
chain.set_hook(nftnl::Hook::In, 1);
chain.set_policy(nftnl::Policy::Accept);
// add chain
batch.add(&chain, nftnl::MsgType::Add);
let rule = Rule::new(&chain);
batch.add(&rule, nftnl::MsgType::Del);
let mut rule = Rule::new(&chain);
rule.add_expr(&nft_expr!(ct state));
rule.add_expr(&nft_expr!(bitwise mask 4u32, xor 0u32));
rule.add_expr(&nft_expr!(cmp != 0u32));
rule.add_expr(&nft_expr!(counter));
rule.add_expr(&nft_expr!(verdict accept));
batch.add(&rule, nftnl::MsgType::Add);
// build and add rules
for ip in ips_add.clone() {
let mut rule = Rule::new(&chain);
rule.add_expr(&nft_expr!(payload ipv4 saddr));
rule.add_expr(&nft_expr!(cmp == ip));
rule.add_expr(&nft_expr!(ct state));
rule.add_expr(&nft_expr!(bitwise mask 10u32, xor 0u32));
rule.add_expr(&nft_expr!(cmp != 0u32));
rule.add_expr(&nft_expr!(counter));
rule.add_expr(&nft_expr!(verdict drop));
batch.add(&rule, nftnl::MsgType::Add);
}
// validate and send batch
let finalized_batch = batch.finalize();
send_and_process(&finalized_batch)?;
if fwlen != &mut ips_add.len() {
ret.push(format!("{length} ip in firewall", length = ips_add.len()));
}
*fwlen = ips_add.len();
Ok(())
}
fn send_and_process(batch: &FinalizedBatch) -> std::result::Result<(), Error> {
let seq: u32 = 2;
let socket = mnl::Socket::new(mnl::Bus::Netfilter)?;
socket.send_all(batch)?;
let mut buffer = vec![0; nftnl::nft_nlmsg_maxsize() as usize];
while let Some(message) = socket_recv(&socket, &mut buffer[..])? {
match mnl::cb_run(message, seq, socket.portid())? {
mnl::CbResult::Stop => {
break;
}
mnl::CbResult::Ok => (),
}
}
Ok(())
}
fn socket_recv<'a>(
socket: &mnl::Socket,
buf: &'a mut [u8],
) -> std::result::Result<Option<&'a [u8]>, Error> {
let ret = socket.recv(buf)?;
if ret > 0 {
Ok(Some(&buf[..ret]))
} else {
Ok(None)
}
}
fn convert(input: &Vec<IpData>) -> Vec<Ipv4Addr> {
let mut output: Vec<Ipv4Addr> = vec![];
for val in input {
output.push(val.ip.parse::<Ipv4Addr>().unwrap());
}
output
}