multicast new prefixes on SIGUSR1

3 files changed, 38 insertions, 0 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 316a3fe..6ca3fe9 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -611,6 +611,7 @@ dependencies = [
  "linkaddrs",
  "pnet_packet",
  "rsdsl_netlinkd",
+ "signal-hook",
  "socket2 0.5.3",
  "thiserror",
 ]
@@ -686,6 +687,25 @@ dependencies = [
 ]
 
 [[package]]
+name = "signal-hook"
+version = "0.3.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8621587d4798caf8eb44879d42e56b9a93ea5dcd315a6487c357130095b62801"
+dependencies = [
+ "libc",
+ "signal-hook-registry",
+]
+
+[[package]]
+name = "signal-hook-registry"
+version = "1.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d8229b473baa5980ac72ef434c4415e70c4b5e71b423043adb4ba059f89c99a1"
+dependencies = [
+ "libc",
+]
+
+[[package]]
 name = "slab"
 version = "0.4.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
diff --git a/Cargo.toml b/Cargo.toml
index 1503a32..f91427b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -8,5 +8,6 @@ ipnet = "2.7.1"
 linkaddrs = { git = "https://github.com/HimbeerserverDE/linkaddrs.git", version = "0.1.0" }
 pnet_packet = "0.33.0"
 rsdsl_netlinkd = { git = "https://github.com/rsdsl/netlinkd.git", version = "0.6.2" }
+signal-hook = "0.3.17"
 socket2 = { version = "0.5.2", features = ["all"] }
 thiserror = "1.0"
diff --git a/src/main.rs b/src/main.rs
index f5188c2..fe857de 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -8,6 +8,7 @@ use ipnet::Ipv6Net;
 use pnet_packet::icmpv6::ndp::{MutableRouterAdvertPacket, NdpOption, NdpOptionType, RouterAdvert};
 use pnet_packet::icmpv6::{Icmpv6Code, Icmpv6Type};
 use rsdsl_netlinkd::link;
+use signal_hook::{consts::SIGUSR1, iterator::Signals};
 use socket2::{Domain, Protocol, SockAddr, Socket, Type};
 use thiserror::Error;
 
@@ -76,6 +77,22 @@ fn run(link: String) -> Result<()> {
         thread::sleep(Duration::from_secs(1200));
     });
 
+    // Send NDP RAs when SIGUSR1 is received.
+    // This updates the prefixes whenever netlinkd informs us of a change.
+    let sock2 = sock.try_clone()?;
+    let link2 = link.clone();
+    thread::spawn(move || match Signals::new([SIGUSR1]) {
+        Ok(mut signals) => {
+            for _ in signals.forever() {
+                match send_ra_multicast(&sock2, link2.clone(), ifi) {
+                    Ok(_) => {}
+                    Err(e) => println!("[warn] sig multicast ra {}: {}", link2, e),
+                }
+            }
+        }
+        Err(e) => println!("[warn] no signal handling on {}: {}", link2, e),
+    });
+
     loop {
         let mut buf = [MaybeUninit::new(0); 1500];
         let (n, raddr) = sock.recv_from(&mut buf)?;