From c7369246ad3b339be9607f7018f8764ee320bd20 Mon Sep 17 00:00:00 2001
From: Lia Lenckowski <lialenck@protonmail.com>
Date: Tue, 13 Aug 2024 21:09:22 +0200
Subject: sync hosts more safely; refactor: split off config

---
 src/daemon_config.rs | 121 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 src/daemon_config.rs

(limited to 'src/daemon_config.rs')

diff --git a/src/daemon_config.rs b/src/daemon_config.rs
new file mode 100644
index 0000000..246a736
--- /dev/null
+++ b/src/daemon_config.rs
@@ -0,0 +1,121 @@
+use atomic_write_file::AtomicWriteFile;
+use defguard_wireguard_rs::{key::Key, net::IpAddrMask};
+use log::info;
+use serde::{Deserialize, Serialize};
+use std::{
+    collections::{BTreeSet, HashMap},
+    fs::File,
+    io::{ErrorKind, Read, Write},
+    net::SocketAddr,
+    path::PathBuf,
+    time::SystemTime,
+};
+use xdg::BaseDirectories;
+
+use crate::daemon::DaemonError;
+
+#[derive(Serialize, Deserialize, Clone)]
+pub enum Endpoint {
+    Ip(SocketAddr),
+    Domain(String, u16),
+}
+
+// subset of defguard_wireguard_rs::host::Peer, with hostname added
+#[derive(Serialize, Deserialize)]
+pub struct PeerConfig {
+    pub psk: Option<Key>,
+    pub ips: Vec<(IpAddrMask, Option<String>)>,
+    // if false: the hostnames are kept around for sharing, but we personally do not use them
+    pub use_hostnames: bool,
+    pub endpoint: Option<Endpoint>,
+
+    pub last_changed: SystemTime,
+    pub known_to: Vec<usize>,
+
+    pub mäsch_endpoint: SocketAddr,
+}
+
+fn default_wg_port() -> u16 {
+    51820
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct Network {
+    pub privkey: String,
+    // this really should be a different type, but this is what defguard takes...
+    pub address: String,
+    #[serde(default = "default_wg_port")]
+    pub listen_port: u16,
+    pub peers: HashMap<Key, PeerConfig>,
+
+    pub mäsch_port: u16,
+}
+
+#[derive(Serialize, Deserialize, Default)]
+pub struct Config {
+    pub networks: HashMap<String, Network>,
+}
+
+pub fn load_config() -> Result<(PathBuf, Config), DaemonError> {
+    let config_path = BaseDirectories::with_prefix("mäsch")?.place_state_file("daemon.json")?;
+    let config: Config = match File::open(&config_path) {
+        Ok(f) => serde_json::from_reader(f)?,
+        Err(e) => match e.kind() {
+            ErrorKind::NotFound => Config::default(),
+            _ => Err(e)?,
+        },
+    };
+    info!("read config");
+
+    Ok((config_path, config))
+}
+
+pub fn write_config(conf: &Config, path: &PathBuf) -> Result<(), std::io::Error> {
+    let mut f = AtomicWriteFile::open(path)?;
+    serde_json::to_writer(&mut f, conf)?;
+    f.commit()?;
+
+    Ok(())
+}
+
+pub fn sync_hostnames(hostnames: &BTreeSet<(String, String)>) -> Result<(), std::io::Error> {
+    let mut hosts_str = match File::open("/etc/hosts") {
+        Ok(mut f) => {
+            let mut r = String::new();
+            f.read_to_string(&mut r)?;
+            r
+        }
+        Err(e) => match e.kind() {
+            ErrorKind::NotFound => "".to_owned(),
+            _ => return Err(e),
+        },
+    };
+
+    let seen_hostnames: BTreeSet<String> = hosts_str
+        .lines()
+        .map(|l| {
+            l.split_whitespace()
+                .take_while(|dom| dom.chars().next().unwrap() != '#')
+                .skip(1)
+        })
+        .flatten()
+        .map(|dom| dom.to_owned())
+        .collect();
+
+    for (ip, dom) in hostnames {
+        if !seen_hostnames.contains(dom.as_str()) {
+            hosts_str.push_str(ip);
+            hosts_str.push(' ');
+            hosts_str.push_str(&format!("{dom}"));
+            hosts_str.push('\n');
+        }
+    }
+
+    info!("Syncing host file");
+
+    let mut f = AtomicWriteFile::open("/etc/hosts")?;
+    f.write(hosts_str.as_bytes())?;
+    f.commit()?;
+
+    Ok(())
+}
-- 
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