feat: parse iiface

src/main.rs

@@ -1,64 +1,105 @@
 const ADDR: Ipv4Addr = Ipv4Addr::new(224, 0, 0, 251);
-use color_eyre::Result;
-use pnet::datalink::interfaces;
+use color_eyre::{eyre::bail, Result};
+use pnet::datalink::{interfaces, NetworkInterface};
 use regex::Regex;
 use simple_dns::Packet;
 use socket2::{Domain, Protocol, Socket, Type};
-use std::net::{Ipv4Addr, SocketAddrV4};
+use std::{
+    collections::HashSet,
+    net::{Ipv4Addr, SocketAddr, SocketAddrV4},
+};
 use tokio::net::UdpSocket;
 
+fn get_iface(from: &SocketAddr, ifaces: &Vec<&NetworkInterface>) -> Result<String> {
+    for i in ifaces {
+        for ip in i.ips.iter() {
+            if ip.contains(from.ip()) {
+                return Ok(i.name.clone());
+            }
+        }
+    }
+    bail!("No interface found")
+}
+
+fn get_questions(packet: &Packet) -> HashSet<String> {
+    packet
+        .questions
+        .iter()
+        .map(|x| x.qname.to_string())
+        .collect()
+}
+fn get_answers(packet: &Packet) -> HashSet<String> {
+    packet.answers.iter().map(|x| x.name.to_string()).collect()
+}
+
+struct Rule {
+    from: Regex,
+    to: String,
+    allow_questions: Regex,
+    allow_answers: Regex,
+}
+
 #[tokio::main]
 async fn main() -> Result<()> {
+    let mut rules = Vec::new();
+    rules.push(Rule {
+        from: Regex::new("lan01")?,
+        to: "lan01".to_string(),
+        allow_answers: Regex::new(".*")?,
+        allow_questions: Regex::new(".*")?,
+    });
+    let iface_reg = Regex::new(r"^lan.*$")?;
+
     let socket = Socket::new(Domain::IPV4, Type::DGRAM, Some(Protocol::UDP))?;
     socket.set_reuse_address(true)?;
     socket.set_reuse_port(true)?;
-    let addr = SocketAddrV4::new(Ipv4Addr::new(224, 0, 0, 251), 5353).into();
+    let addr = SocketAddrV4::new(ADDR, 5353).into();
     socket.bind(&addr)?;
-    socket.join_multicast_v4(&ADDR, &Ipv4Addr::new(10, 99, 10, 1))?;
+    socket.join_multicast_v4(&ADDR, &Ipv4Addr::UNSPECIFIED)?;
     //socket.set_nonblocking(true)?;
 
-    let iface_reg = Regex::new(r"^lan.*$")?;
     let interfaces = interfaces();
-    let interfaces = interfaces.iter().filter(|x| {
+    let interfaces = interfaces
+        .iter()
+        .filter(|x| {
             x.is_up() && !x.is_loopback() && !x.ips.is_empty() && iface_reg.is_match(&x.name)
-    });
-    for i in interfaces {
-        println!("{:?}", i);
-    }
-
+        })
+        .collect();
+    println!("{:?}", interfaces);
     let mut buf = [0; 1024];
     let socket = UdpSocket::from_std(socket.into())?;
     loop {
         match socket.recv_from(&mut buf).await {
             Ok((_l, from)) => {
                 let packet = Packet::parse(&buf)?;
-                println!("{:?} {:?}\n", from, packet);
+                //println!("{:?} {:?}\n", from, packet);
+                let iface = match get_iface(&from, &interfaces) {
+                    Err(_) => {
+                        eprintln!("Invalid packet received from {}", from);
+                        continue;
+                    }
+                    Ok(name) => name,
+                };
+                let questions = get_questions(&packet);
+                let answers = get_answers(&packet);
+                println!(
+                    "received packet on interface {} from {} questioning {:?} and answering {:?}",
+                    iface, from, questions, answers
+                );
+                let mut out = HashSet::new();
+                for r in &rules {
+                    if r.from.is_match(&iface)
+                        && (questions.iter().any(|x| r.allow_questions.is_match(x))
+                            || answers.iter().any(|x| r.allow_answers.is_match(x)))
+                    {
+                        out.insert(r.to.clone());
+                    }
+                }
+                out.remove(&iface);
+                println!("relaying packet to {:?}", out);
+                // socket.send_to(&buf, addr);
             }
             Err(_) => todo!(),
         }
     }
 }
-/*
-    let socket = UdpSocket::bind((Ipv4Addr::UNSPECIFIED, 5354))?;
-
-} */
-/*
- table ip mdns {
-        chain prerouting {
-            type filter hook prerouting priority mangle; policy accept;
-
-            iifname lan01 ip daddr 224.0.0.251 meta mark 0xa5f3 jump mdns-saddr
-            iifname lan01 ip daddr 224.0.0.251 meta mark != 0xa5f3 jump mdns
-        }
-        chain mdns {
-            meta mark set 0xa5f3
-            iifname lan01 dup to 224.0.0.251
-        }
-        chain mdns-saddr {
-            # repeat mDNS from IoT to main
-            #iifname lan-services ip saddr set 10.99.20.1
-            #iifname lan-home ip saddr set 10.99.10.1
-            iifname lan01 udp dport set 5354
-        }
-      }
-*/