initial b4 impl

3 files changed, 129 insertions, 2 deletions

diff --git a/src/error.rs b/src/error.rs
new file mode 100644
index 0000000..5264e41
--- /dev/null
+++ b/src/error.rs
@@ -0,0 +1,27 @@
+use std::io;
+
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("not enough ipv6 subnets")]
+    NotEnoughIpv6Subnets,
+    #[error("no address associated with aftr name")]
+    NoDnsRecord,
+
+    #[error("io: {0}")]
+    Io(#[from] io::Error),
+
+    #[error("ipnet prefix len: {0}")]
+    IpnetPrefixLen(#[from] ipnet::PrefixLenError),
+    #[error("rsdsl_netlinkd: {0}")]
+    RsdslNetlinkd(#[from] rsdsl_netlinkd::error::Error),
+    #[error("rsdsl_netlinkd_sys: {0}")]
+    RsdslNetlinkdSys(#[from] rsdsl_netlinkd_sys::Error),
+    #[error("serde_json: {0}")]
+    SerdeJson(#[from] serde_json::Error),
+    #[error("trust_dns_resolver resolve: {0}")]
+    TrustDnsResolverResolve(#[from] trust_dns_resolver::error::ResolveError),
+}
+
+pub type Result<T> = std::result::Result<T, Error>;
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..7edf3bf
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,2 @@
+mod error;
+pub use error::*;
diff --git a/src/main.rs b/src/main.rs
index e7a11a9..f597b04 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,3 +1,101 @@
-fn main() {
-    println!("Hello, world!");
+use std::fs::File;
+use std::net::{Ipv4Addr, Ipv6Addr, SocketAddr};
+use std::path::Path;
+use std::thread;
+use std::time::Duration;
+
+use ipnet::Ipv6Net;
+use rsdsl_dslite::{Error, Result};
+use rsdsl_ip_config::DsConfig;
+use rsdsl_netlinkd::{addr, link, route};
+use rsdsl_netlinkd_sys::IpIp6;
+use rsdsl_pd_config::PdConfig;
+use trust_dns_resolver::config::{NameServerConfig, Protocol, ResolverConfig, ResolverOpts};
+use trust_dns_resolver::Resolver;
+
+const ADDR4_AFTR: Ipv4Addr = Ipv4Addr::new(192, 0, 0, 1);
+const ADDR4_B4: Ipv4Addr = Ipv4Addr::new(192, 0, 0, 2);
+
+fn main() -> Result<()> {
+    println!("wait for up ppp0");
+    link::wait_up("ppp0".into())?;
+
+    let pd_config = Path::new(rsdsl_pd_config::LOCATION);
+
+    println!("wait for dhcp6");
+    while !pd_config.exists() {
+        thread::sleep(Duration::from_secs(8));
+    }
+
+    let mut file = File::open(rsdsl_pd_config::LOCATION)?;
+    let pdconfig: PdConfig = serde_json::from_reader(&mut file)?;
+
+    if let Some(ref aftr) = pdconfig.aftr {
+        let local = local_address(&pdconfig)?;
+        let remote = resolve6(&pdconfig, aftr)?;
+        let _tnl = IpIp6::new("dslite0", "ppp0", local, remote)?;
+
+        configure_dslite();
+    } else {
+        println!("no aftr");
+    }
+
+    loop {
+        thread::sleep(Duration::MAX);
+    }
+}
+
+fn configure_dslite() {
+    match configure_dslite0() {
+        Ok(_) => println!("configure dslite0"),
+        Err(e) => println!("can't configure dslite0: {}", e),
+    }
+}
+
+fn configure_dslite0() -> Result<()> {
+    link::up("dslite0".into())?;
+
+    addr::flush("dslite0".into())?;
+    addr::add("dslite0".into(), ADDR4_B4.into(), 29)?;
+
+    let mut file = File::open(rsdsl_ip_config::LOCATION)?;
+    let dsconfig: DsConfig = serde_json::from_reader(&mut file)?;
+
+    // Check for native connectivity to avoid breaking netlinkd.
+    if dsconfig.v4.is_none() {
+        route::add4(Ipv4Addr::UNSPECIFIED, 0, Some(ADDR4_AFTR), "dslite0".into())?;
+    }
+
+    Ok(())
+}
+
+fn local_address(pdconfig: &PdConfig) -> Result<Ipv6Addr> {
+    let prefix = Ipv6Net::new(pdconfig.prefix, pdconfig.len)?.trunc();
+    let mut subnets = prefix.subnets(64)?;
+
+    let addr = next_ifid1(&mut subnets)?;
+    Ok(addr)
+}
+
+fn next_ifid1<T: Iterator<Item = Ipv6Net>>(subnets: &mut T) -> Result<Ipv6Addr> {
+    Ok((u128::from(subnets.next().ok_or(Error::NotEnoughIpv6Subnets)?.addr()) + 1).into())
+}
+
+fn resolve6(pdconfig: &PdConfig, fqdn: &str) -> Result<Ipv6Addr> {
+    let mut cfg = ResolverConfig::new();
+
+    cfg.add_name_server(NameServerConfig::new(
+        SocketAddr::new(pdconfig.dns1.into(), 53),
+        Protocol::Udp,
+    ));
+    cfg.add_name_server(NameServerConfig::new(
+        SocketAddr::new(pdconfig.dns2.into(), 53),
+        Protocol::Udp,
+    ));
+
+    let resolver = Resolver::new(cfg, ResolverOpts::default())?;
+    let response = resolver.ipv6_lookup(fqdn)?;
+
+    let addr = response.iter().next().ok_or(Error::NoDnsRecord)?;
+    Ok(*addr)
 }