From 1ede90cc29b5b56deb8c8cd2964f08227a839f65 Mon Sep 17 00:00:00 2001
From: Ishan Jain <contact@ishanjain.me>
Date: Fri, 28 Jul 2023 15:57:54 +0530
Subject: [PATCH] removed duplicate code, optimized processor

---
 src/communications.rs |  6 ++--
 src/main.rs           |  9 +++---
 src/processor.rs      | 72 +++++++++++++++++--------------------------
 3 files changed, 36 insertions(+), 51 deletions(-)

diff --git a/src/communications.rs b/src/communications.rs
index 2881cce..a0e38aa 100644
--- a/src/communications.rs
+++ b/src/communications.rs
@@ -14,8 +14,6 @@ impl Communications {
     pub async fn start_listeners(&mut self) -> Result<(), String> {
         info!("listener started");
 
-        let tx_chan = self.tx_chan.clone();
-
         let interfaces = get_if_addrs::get_if_addrs().unwrap();
         trace!("Interfaces list: {:?}", interfaces);
 
@@ -35,7 +33,9 @@ impl Communications {
         loop {
             match multicast_socket.receive() {
                 Ok(msg) => {
-                    tx_chan.send(msg).expect("error in sending to mpsc channel");
+                    self.tx_chan
+                        .send(msg)
+                        .expect("error in sending to mpsc channel");
                 }
                 Err(e) if e.to_string().contains("EAGAIN") => continue,
                 Err(e) => {
diff --git a/src/main.rs b/src/main.rs
index 6490447..b3d746a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,18 +3,17 @@
 // support. So, 1 for MDNS, another for WSDD?
 // Or a common listener/transmitter and then different modules to parse and transmit each type of
 // traffic
+use log::info;
+use multicast_socket::Message;
+use std::sync::mpsc::{self, Receiver, Sender};
+use tokio::runtime::Runtime;
 
 pub mod communications;
-use std::sync::mpsc::{self, Receiver, Sender};
-
 pub use communications::*;
 pub mod config;
 pub use config::*;
 pub mod processor;
-use log::info;
-use multicast_socket::Message;
 pub use processor::*;
-use tokio::runtime::Runtime;
 
 fn main() {
     env_logger::init();
diff --git a/src/processor.rs b/src/processor.rs
index 0192cc1..d17a1ed 100644
--- a/src/processor.rs
+++ b/src/processor.rs
@@ -49,64 +49,50 @@ impl Processor {
                 packet.answers.iter().map(|q| q.name).collect::<Vec<_>>()
             );
             for conf in &self.config.mdns {
+                let mut forward = false;
+                let mut dst_ifs = vec![];
+
                 for query in &packet.questions {
-                    let forward = conf.destinations.contains(&src_ifname)
+                    forward |= conf.destinations.contains(&src_ifname)
                         && (conf.filters.is_empty()
                             || conf.filters.contains(&query.qname.to_string()));
 
                     if forward {
-                        let dst_ifs = conf
-                            .sources
-                            .clone()
-                            .into_iter()
-                            .filter_map(|dst_if| interfaces.iter().find(|x| x.name == dst_if));
-
-                        for dst_if in dst_ifs {
-                            let dst_ifid = ifname_to_ifidx(dst_if.name.to_string());
-
-                            info!(
-                                "forwarding {:?} from {:?} to {:?}({})",
-                                packet, src_ifname, dst_if, dst_ifid
-                            );
-                            // TODO(ishan): Take a note of transaction id
-                            // and avoid feedback loops
-                            socket
-                                .send(&evt.data, &Interface::Index(dst_ifid as i32))
-                                .expect("error in sending mdns packet");
-                        }
+                        dst_ifs.extend(
+                            conf.sources
+                                .iter()
+                                .filter_map(|dst_if| interfaces.iter().find(|x| &x.name == dst_if)),
+                        );
                     }
                 }
 
                 for answer in &packet.answers {
-                    let forward = conf.sources.contains(&src_ifname)
+                    forward |= conf.sources.contains(&src_ifname)
                         && (conf.filters.is_empty()
                             || conf.filters.contains(&answer.name.to_string()));
 
                     if forward {
-                        let dst_ifs = conf
-                            .destinations
-                            .clone()
-                            .into_iter()
-                            .filter_map(|dst_if| interfaces.iter().find(|x| x.name == dst_if));
-
-                        // TODO(ishan): Stop blasting this every where.
-                        // Try to limit answers traffic between destinations
-                        // it should not be broadcasting an answer to all networks just because 1
-                        // asked for it
-                        for dst_if in dst_ifs {
-                            let dst_ifid = ifname_to_ifidx(dst_if.name.to_string());
-
-                            info!(
-                                "forwarding {:?} from {:?} to {:?}({})",
-                                packet, src_ifname, dst_if, dst_ifid
-                            );
-
-                            socket
-                                .send(&evt.data, &Interface::Index(dst_ifid as i32))
-                                .expect("error in sending mdns packet");
-                        }
+                        dst_ifs.extend(
+                            conf.destinations
+                                .iter()
+                                .filter_map(|dst_if| interfaces.iter().find(|x| &x.name == dst_if)),
+                        );
                     }
                 }
+
+                for dst_if in dst_ifs {
+                    let dst_ifid = ifname_to_ifidx(dst_if.name.to_string());
+
+                    info!(
+                        "forwarding {:?} from {:?} to {:?}({})",
+                        packet, src_ifname, dst_if, dst_ifid
+                    );
+                    // TODO(ishan): Take a note of transaction id
+                    // and avoid feedback loops
+                    socket
+                        .send(&evt.data, &Interface::Index(dst_ifid as i32))
+                        .expect("error in sending mdns packet");
+                }
             }
         }
     }