reconfigure tunnel if dhcp6 reconnects

4 files changed, 58 insertions, 12 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 212e1e8..b260bb1 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -649,6 +649,24 @@ dependencies = [
 ]
 
 [[package]]
+name = "notify"
+version = "6.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5738a2795d57ea20abec2d6d76c6081186709c0024187cd5977265eda6598b51"
+dependencies = [
+ "bitflags 1.3.2",
+ "crossbeam-channel",
+ "filetime",
+ "fsevent-sys",
+ "inotify",
+ "kqueue",
+ "libc",
+ "mio",
+ "walkdir",
+ "windows-sys 0.45.0",
+]
+
+[[package]]
 name = "num_cpus"
 version = "1.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -849,6 +867,7 @@ name = "rsdsl_dslite"
 version = "0.1.0"
 dependencies = [
  "ipnet",
+ "notify 6.0.1",
  "rsdsl_ip_config",
  "rsdsl_netlinkd",
  "rsdsl_netlinkd_sys",
@@ -875,7 +894,7 @@ dependencies = [
  "futures-util",
  "ipnet",
  "netlink-packet-route",
- "notify",
+ "notify 5.2.0",
  "rsdsl_ip_config",
  "rsdsl_pd_config",
  "rtnetlink",
diff --git a/Cargo.toml b/Cargo.toml
index b6d9290..6648126 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -7,6 +7,7 @@ edition = "2021"
 
 [dependencies]
 ipnet = "2.8.0"
+notify = "6.0.1"
 rsdsl_ip_config = { git = "https://github.com/rsdsl/ip_config.git", version = "0.2.2" }
 rsdsl_netlinkd = { git = "https://github.com/rsdsl/netlinkd.git", version = "0.6.2" }
 rsdsl_netlinkd_sys = { git = "https://github.com/rsdsl/netlinkd.git", version = "0.4.9" }
diff --git a/src/error.rs b/src/error.rs
index 5264e41..03145e1 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -14,6 +14,8 @@ pub enum Error {
 
     #[error("ipnet prefix len: {0}")]
     IpnetPrefixLen(#[from] ipnet::PrefixLenError),
+    #[error("notify: {0}")]
+    Notify(#[from] notify::Error),
     #[error("rsdsl_netlinkd: {0}")]
     RsdslNetlinkd(#[from] rsdsl_netlinkd::error::Error),
     #[error("rsdsl_netlinkd_sys: {0}")]
diff --git a/src/main.rs b/src/main.rs
index aaeede0..bce8ce8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -5,6 +5,8 @@ use std::thread;
 use std::time::Duration;
 
 use ipnet::Ipv6Net;
+use notify::event::{CreateKind, ModifyKind};
+use notify::{Event, EventKind, RecursiveMode, Watcher};
 use rsdsl_dslite::{Error, Result};
 use rsdsl_ip_config::DsConfig;
 use rsdsl_netlinkd::{addr, link, route};
@@ -29,19 +31,41 @@ fn main() -> Result<()> {
         thread::sleep(Duration::from_secs(8));
     }
 
-    let mut file = File::open(rsdsl_pd_config::LOCATION)?;
-    let pdconfig: PdConfig = serde_json::from_reader(&mut file)?;
+    let mut tnl = None;
 
-    let _tnl;
-    if let Some(ref aftr) = pdconfig.aftr {
-        let local = local_address(&pdconfig)?;
-        let remote = multitry_resolve6(&pdconfig, aftr)?;
-        _tnl = IpIp6::new("dslite0", "ppp0", local, remote)?;
+    let do_setup = |tnl: &mut Option<IpIp6>| -> Result<()> {
+        let mut file = File::open(rsdsl_pd_config::LOCATION)?;
+        let pdconfig: PdConfig = serde_json::from_reader(&mut file)?;
 
-        configure_dslite();
-    } else {
-        println!("no aftr");
-    }
+        if let Some(ref aftr) = pdconfig.aftr {
+            let local = local_address(&pdconfig)?;
+            let remote = multitry_resolve6(&pdconfig, aftr)?;
+            *tnl = Some(IpIp6::new("dslite0", "ppp0", local, remote)?);
+
+            configure_dslite();
+        } else {
+            println!("no aftr");
+        }
+
+        Ok(())
+    };
+    let setup = move |tnl: &mut Option<IpIp6>| match do_setup(tnl) {
+        Ok(_) => {}
+        Err(e) => println!("can't create dslite0: {}", e),
+    };
+
+    setup(&mut tnl);
+
+    let mut watcher = notify::recommended_watcher(move |res: notify::Result<Event>| match res {
+        Ok(event) => match event.kind {
+            EventKind::Create(kind) if kind == CreateKind::File => setup(&mut tnl),
+            EventKind::Modify(kind) if matches!(kind, ModifyKind::Data(_)) => setup(&mut tnl),
+            _ => {}
+        },
+        Err(e) => println!("watch error: {:?}", e),
+    })?;
+
+    watcher.watch(pd_config, RecursiveMode::NonRecursive)?;
 
     loop {
         thread::sleep(Duration::MAX);