feat(homelab): add dhcp lease parsing

nix/homelab/Cargo.lock

@@ -58,6 +58,28 @@ version = "1.0.100"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a23eb6b1614318a8071c9b2521f36b424b2c83db5eb3a0fead4a6c0809af6e61"
 
+[[package]]
+name = "bitflags"
+version = "2.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
+
+[[package]]
+name = "cc"
+version = "1.2.51"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7a0aeaff4ff1a90589618835a598e545176939b97874f7abc7851caa0618f203"
+dependencies = [
+ "find-msvc-tools",
+ "shlex",
+]
+
+[[package]]
+name = "cfg-if"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
+
 [[package]]
 name = "clap"
 version = "4.5.53"
@@ -110,6 +132,12 @@ version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
+[[package]]
+name = "find-msvc-tools"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "645cbb3a84e60b7531617d5ae4e57f7e27308f6445f5abf653209ea76dec8dff"
+
 [[package]]
 name = "hashbrown"
 version = "0.16.1"
@@ -128,7 +156,9 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "clap",
+ "nom",
  "serde",
+ "ssh2",
  "thiserror",
  "toml",
 ]
@@ -149,12 +179,109 @@ version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a6cb138bb79a146c1bd460005623e142ef0181e3d0219cb493e02f7d08a35695"
 
+[[package]]
+name = "libc"
+version = "0.2.178"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "37c93d8daa9d8a012fd8ab92f088405fb202ea0b6ab73ee2482ae66af4f42091"
+
+[[package]]
+name = "libssh2-sys"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "220e4f05ad4a218192533b300327f5150e809b54c4ec83b5a1d91833601811b9"
+dependencies = [
+ "cc",
+ "libc",
+ "libz-sys",
+ "openssl-sys",
+ "pkg-config",
+ "vcpkg",
+]
+
+[[package]]
+name = "libz-sys"
+version = "1.1.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "15d118bbf3771060e7311cc7bb0545b01d08a8b4a7de949198dec1fa0ca1c0f7"
+dependencies = [
+ "cc",
+ "libc",
+ "pkg-config",
+ "vcpkg",
+]
+
+[[package]]
+name = "lock_api"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "224399e74b87b5f3557511d98dff8b14089b3dadafcab6bb93eab67d3aace965"
+dependencies = [
+ "scopeguard",
+]
+
+[[package]]
+name = "memchr"
+version = "2.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f52b00d39961fc5b2736ea853c9cc86238e165017a493d1d5c8eac6bdc4cc273"
+
+[[package]]
+name = "nom"
+version = "8.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "df9761775871bdef83bee530e60050f7e54b1105350d6884eb0fb4f46c2f9405"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "once_cell_polyfill"
 version = "1.70.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "384b8ab6d37215f3c5301a95a4accb5d64aa607f1fcb26a11b5303878451b4fe"
 
+[[package]]
+name = "openssl-sys"
+version = "0.9.111"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "82cab2d520aa75e3c58898289429321eb788c3106963d0dc886ec7a5f4adc321"
+dependencies = [
+ "cc",
+ "libc",
+ "pkg-config",
+ "vcpkg",
+]
+
+[[package]]
+name = "parking_lot"
+version = "0.12.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93857453250e3077bd71ff98b6a65ea6621a19bb0f559a85248955ac12c45a1a"
+dependencies = [
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.9.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2621685985a2ebf1c516881c026032ac7deafcda1a2c9b7850dc81e3dfcb64c1"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "windows-link",
+]
+
+[[package]]
+name = "pkg-config"
+version = "0.3.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7edddbd0b52d732b21ad9a5fab5c704c14cd949e5e9a1ec5929a24fded1b904c"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.103"
@@ -173,6 +300,21 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "redox_syscall"
+version = "0.5.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed2bf2547551a7053d6fdfafda3f938979645c44812fbfcda098faae3f1a362d"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "scopeguard"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+
 [[package]]
 name = "serde"
 version = "1.0.228"
@@ -212,6 +354,30 @@ dependencies = [
  "serde_core",
 ]
 
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
+[[package]]
+name = "smallvec"
+version = "1.15.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "67b1b7a3b5fe4f1376887184045fcf45c69e92af734b7aaddc05fb777b6fbd03"
+
+[[package]]
+name = "ssh2"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2f84d13b3b8a0d4e91a2629911e951db1bb8671512f5c09d7d4ba34500ba68c8"
+dependencies = [
+ "bitflags",
+ "libc",
+ "libssh2-sys",
+ "parking_lot",
+]
+
 [[package]]
 name = "strsim"
 version = "0.11.1"
@@ -300,6 +466,12 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"
 
+[[package]]
+name = "vcpkg"
+version = "0.2.15"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "accd4ea62f7bb7a82fe23066fb0957d48ef677f6eeb8215f372f52e48bb32426"
+
 [[package]]
 name = "windows-link"
 version = "0.2.1"

nix/homelab/Cargo.toml

@@ -6,6 +6,8 @@ edition = "2024"
 [dependencies]
 anyhow = "1.0.100"
 clap = { version = "4.5.53", features = ["derive"] }
+nom = "8.0.0"
 serde = { version = "1.0.228", features = ["serde_derive"] }
+ssh2 = "0.9.5"
 thiserror = "2.0.17"
 toml = "0.9.10"

nix/homelab/src/commands.rs

@@ -6,4 +6,6 @@ use clap::Subcommand;
 pub enum Commands {
     /// generate gateway api routes
     GenerateRoutes,
+    /// sync dns records with pi-hole
+    SyncDNS,
 }

nix/homelab/src/dns.rs

@@ -0,0 +1,20 @@
+use crate::{
+    error::Result,
+    lease_parser::{Lease, parse_leases},
+    transport::Transport,
+};
+
+pub struct Router<T: Transport> {
+    transport: T,
+}
+
+impl<T: Transport> Router<T> {
+    pub fn new(transport: T) -> Self {
+        Self { transport }
+    }
+
+    pub fn dhcp_leases(&self, resource: &str) -> Result<Vec<Lease>> {
+        let raw = self.transport.fetch(resource)?;
+        parse_leases(&raw).map_err(|e| crate::error::Error::Parse(e.to_string()))
+    }
+}

nix/homelab/src/error.rs

@@ -0,0 +1,15 @@
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum Error {
+    #[error("SSH error: {0}")]
+    SSH(#[from] ssh2::Error),
+    #[error("parse error: {0}")]
+    Parse(String),
+    #[error("IO error: {0}")]
+    IO(#[from] std::io::Error),
+    #[error("command return non 0 exit code: {0}")]
+    ExitCode(i32),
+}
+
+pub type Result<T> = std::result::Result<T, Error>;

nix/homelab/src/lease_parser.rs

@@ -0,0 +1,146 @@
+use std::net::IpAddr;
+
+use nom::{
+    IResult, Parser,
+    branch::alt,
+    bytes::complete::{tag, take_till, take_until, take_while1},
+    character::complete::{char, digit1, multispace1, space0, space1},
+    combinator::{map, map_res, value},
+    multi::many0,
+    sequence::{delimited, preceded, terminated},
+};
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct Lease {
+    pub ip: IpAddr,
+    pub binding_state: BindingState,
+    pub client_hostname: Option<String>,
+}
+
+#[allow(dead_code)]
+#[derive(Debug, Clone, PartialEq)]
+pub enum BindingState {
+    Active,
+    Free,
+    Abandoned,
+    Backup,
+}
+
+#[allow(dead_code)]
+#[derive(Debug, Clone)]
+enum LeaseField {
+    BindingState(BindingState),
+    ClientHostname(String),
+    Other,
+}
+
+fn ws(input: &str) -> IResult<&str, ()> {
+    value(
+        (),
+        many0(alt((
+            value((), multispace1),
+            value((), (tag("#"), take_until("\n"), tag("\n"))),
+        ))),
+    )
+    .parse(input)
+}
+
+fn parse_ip(input: &str) -> IResult<&str, IpAddr> {
+    map_res(
+        take_while1(|c: char| c.is_ascii_digit() || c == '.'),
+        str::parse,
+    )
+    .parse(input)
+}
+
+fn parse_field(input: &str) -> IResult<&str, LeaseField> {
+    alt((
+        map(
+            preceded(
+                (tag("client-hostname"), space1),
+                terminated(
+                    delimited(char('"'), take_until("\""), char('"')),
+                    (space0, char(';')),
+                ),
+            ),
+            |h: &str| LeaseField::ClientHostname(h.to_string()),
+        ),
+        map(
+            preceded(
+                (tag("binding"), space1, tag("state"), space1),
+                terminated(
+                    alt((
+                        value(BindingState::Active, tag("active")),
+                        value(BindingState::Free, tag("free")),
+                        value(BindingState::Abandoned, tag("abandoned")),
+                        value(BindingState::Backup, tag("backup")),
+                    )),
+                    (space0, char(';')),
+                ),
+            ),
+            LeaseField::BindingState,
+        ),
+        value(
+            LeaseField::Other,
+            preceded(
+                (tag("uid"), space1),
+                terminated(
+                    delimited(char('"'), take_until("\""), char('"')),
+                    (space0, char(';')),
+                ),
+            ),
+        ),
+        value(
+            LeaseField::Other,
+            (take_till(|c| c == ';' || c == '}'), char(';')),
+        ),
+    ))
+    .parse(input)
+}
+
+pub fn parse_lease(input: &str) -> IResult<&str, Lease> {
+    let (input, _) = ws(input)?;
+    let (input, _) = tag("lease").parse(input)?;
+    let (input, _) = space1(input)?;
+    let (input, ip) = parse_ip(input)?;
+    let (input, _) = space0(input)?;
+    let (input, _) = char('{').parse(input)?;
+    let (input, _) = ws(input)?;
+
+    let (input, fields) = many0(terminated(parse_field, ws)).parse(input)?;
+
+    let (input, _) = char('}').parse(input)?;
+    let (input, _) = ws(input)?;
+
+    let mut lease = Lease {
+        ip,
+        binding_state: BindingState::Free,
+        client_hostname: None,
+    };
+
+    for field in fields {
+        match field {
+            LeaseField::BindingState(s) => lease.binding_state = s,
+            LeaseField::ClientHostname(h) => lease.client_hostname = Some(h),
+            LeaseField::Other => {}
+        }
+    }
+
+    Ok((input, lease))
+}
+
+pub fn parse_leases(input: &str) -> Result<Vec<Lease>, nom::Err<nom::error::Error<&str>>> {
+    let mut leases = Vec::new();
+    let Some(start) = input.find("\nlease ") else {
+        return Ok(leases);
+    };
+
+    let mut remaining = &input[start..];
+
+    while !remaining.is_empty() {
+        let (rest, lease) = parse_lease(remaining)?;
+        leases.push(lease);
+        remaining = rest;
+    }
+    Ok(leases)
+}

nix/homelab/src/main.rs

@@ -1,4 +1,8 @@
 mod commands;
+mod dns;
+mod error;
+mod lease_parser;
+mod transport;
 
 use std::path::Path;
 
@@ -7,9 +11,14 @@ use clap::{CommandFactory, Parser};
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
-use crate::commands::{
+use crate::{
+    commands::{
         Commands,
         generate_routes::{Route, generate_routes},
+    },
+    dns::Router,
+    lease_parser::{BindingState, Lease},
+    transport::SSHTransport,
 };
 
 #[derive(Parser, Debug)]
@@ -50,6 +59,20 @@ fn main() -> anyhow::Result<()> {
             let config = parse_config("./config.toml")?;
             generate_routes(&config)?;
         }
+        Some(Commands::SyncDNS {}) => {
+            let r = Router::new(SSHTransport::new("192.168.15.1:22")?);
+            let leases = r
+                .dhcp_leases("/var/dhcpd/var/db/dhcpd.leases")?
+                .into_iter()
+                .filter(|l| {
+                    if !(l.binding_state == BindingState::Active && l.client_hostname.is_some()) {
+                        return false;
+                    }
+                    true
+                })
+                .collect::<Vec<Lease>>();
+            println!("{:#?}", leases);
+        }
         None => Cli::command().print_long_help()?,
     }
 

nix/homelab/src/transport.rs

@@ -0,0 +1,9 @@
+mod ssh;
+
+pub use ssh::SSHTransport;
+
+use crate::error::Result;
+
+pub trait Transport {
+    fn fetch(&self, resource: &str) -> Result<String>;
+}

nix/homelab/src/transport/ssh.rs

@@ -0,0 +1,46 @@
+use std::{io::Read, net::TcpStream, path::Path};
+
+use ssh2::Session;
+
+use crate::{error::Result, transport::Transport};
+
+pub struct SSHTransport {
+    session: Session,
+}
+
+impl SSHTransport {
+    pub fn new(host: &str) -> Result<Self> {
+        let stream = TcpStream::connect(host)?;
+
+        let mut s = Self {
+            session: Session::new()?,
+        };
+        s.session.set_tcp_stream(stream);
+        s.session.handshake()?;
+        s.session.userauth_pubkey_file(
+            "luca",
+            None,
+            Path::new("/home/luca/.ssh/id_ed25519"),
+            None,
+        )?;
+        Ok(s)
+    }
+}
+
+impl Transport for SSHTransport {
+    fn fetch(&self, resource: &str) -> Result<String> {
+        let mut channel = self.session.channel_session()?;
+        channel.exec(&format!("cat {}", resource))?;
+
+        let mut output = String::new();
+        channel.read_to_string(&mut output)?;
+        channel.wait_close()?;
+
+        let c = channel.exit_status()?;
+        if c != 0 {
+            return Err(crate::error::Error::ExitCode(c));
+        }
+
+        Ok(output)
+    }
+}