v0.1.7

Cargo.lock

@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "anyhow"
+version = "1.0.97"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcfed56ad506cb2c684a14971b8861fdc3baaaae314b9e5f9bb532cbe3ba7a4f"
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -20,6 +26,21 @@ version = "2.9.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5c8214115b7bf84099f1309324e63141d4c5d7cc26862f97a0a857dbefe165bd"
 
+[[package]]
+name = "camino"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b96ec4966b5813e2c0507c1f86115c8c5abaadc3980879c3424042a02fd1ad3"
+
+[[package]]
+name = "cc"
+version = "1.2.17"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1fcb57c740ae1daf453ae85f16e37396f672b039e00d9d866e07ddb24e328e3a"
+dependencies = [
+ "shlex",
+]
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
@@ -86,13 +107,16 @@ dependencies = [
 
 [[package]]
 name = "lookaround"
-version = "0.1.6"
+version = "0.1.7"
 dependencies = [
+ "anyhow",
+ "camino",
  "configparser",
  "directories",
  "mac_address",
  "nix",
  "rand",
+ "sys-info",
  "thiserror",
  "tokio",
 ]
@@ -249,6 +273,12 @@ dependencies = [
  "redox_syscall",
 ]
 
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
 [[package]]
 name = "syn"
 version = "1.0.82"
@@ -260,6 +290,16 @@ dependencies = [
  "unicode-xid",
 ]
 
+[[package]]
+name = "sys-info"
+version = "0.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b3a0d0aba8bf96a0e1ddfdc352fc53b3df7f39318c71854910c3c4b024ae52c"
+dependencies = [
+ "cc",
+ "libc",
+]
+
 [[package]]
 name = "thiserror"
 version = "1.0.30"

Cargo.toml

@@ -9,14 +9,17 @@ license = "AGPL-3.0"
 name = "lookaround"
 readme = "README.md"
 repository = "https://six-five-six-four.com/git/reactor/lookaround"
-version = "0.1.6"
+version = "0.1.7"
 
 [dependencies]
+anyhow = "1.0.97"
+camino = "1.1.9"
 configparser = "3.0.0"
 directories = "5.0.0"
 mac_address = "1.1.8"
 nix = "0.29.0"
 rand = "0.8.4"
+sys-info = "0.9.1"
 thiserror = "1.0.30"
 tokio = { version = "1.14.0", features = ["fs", "net", "rt", "time"] }
 

README.md

@@ -28,51 +28,38 @@ Make sure Cargo is installed from [RustUp.](https://rustup.rs/)
 cargo install lookaround
 
 # Find your config directory
-# Prints something like `Using config dir "/home/user/.config/lookaround"`
+# e.g. `$HOME/.config/lookaround`
 lookaround config
 ```
 
-Create the files `client.ini` and/or `server.ini` in that directory
-(e.g. /home/user/.config/lookaround/server.ini)
+Use `$HOME/.config/lookaround/client.ini` as a hosts file if it's more convenient
+for your client to be the source of truth for nicknames.
 
 ```ini
-# Clients can store MAC-nickname pairs in client.ini, like a hosts file.
-# This is useful if your servers are short-lived and you want the clients
-# to be the source of truth for nicknames.
 [nicknames]
-11-11-11-11-11-11 = laptop
-22-22-22-22-22-22 = desktop
+11-11-11-11-11-11 = bob-laptop
+22-22-22-22-22-22 = alice-desktop
 ```
 
+LookAround will use the system's hostname as its server nickname.
+If you have a generic hostname like `ubuntu`, override this in `$HOME/.config/lookaround/server.ini`:
+
 ```ini
-# Long-lived servers can have their nickname configured in server.ini
 [server]
-nickname = my-computer
+nickname = alice-desktop
 ```
 
 ## Auto-Start (Linux)
 
-Put this systemd unit in `~/.config/systemd/user/lookaround.service`:
+Run `lookaround install` or `lookaround install $NICKNAME` if you want to set a nickname.
 
-```ini
-[Unit]
-Description=LookAround
+This will create `$HOME/.config/lookaround/server.ini` and `$HOME/.config/systemd/user/lookaround.service`, and start the systemd user service.
 
-[Service]
-ExecStart=/home/user/.cargo/bin/lookaround server
-Restart=always
-
-[Install]
-WantedBy=default.target
-```
-
-Then start the service, check that it's running okay, and enable it for
-auto-start:
+To check that it's running
 
 ```bash
-systemctl --user start lookaround
 systemctl --user status lookaround
-systemctl --user enable lookaround
+lookaround client
 ```
 
 ## Auto-Start (Windows)

src/app_common.rs

@@ -1,11 +1,18 @@
 use crate::prelude::*;
+use directories::ProjectDirs;
 
-pub const LOOKAROUND_VERSION: &str = env!("CARGO_PKG_VERSION");
-
-pub fn find_project_dirs() -> Option<ProjectDirs> {
+pub fn try_project_dir() -> Option<ProjectDirs> {
     ProjectDirs::from("", "ReactorScram", "LookAround")
 }
 
+pub fn try_config_dir() -> Option<PathBuf> {
+    Some(try_project_dir()?.config_local_dir().into())
+}
+
+pub fn try_server_config_path() -> Option<PathBuf> {
+    Some(try_config_dir()?.join("server.ini"))
+}
+
 #[derive(Debug, thiserror::Error)]
 pub enum AppError {
     #[error(transparent)]

src/avalanche.rs

@@ -1,26 +0,0 @@
-type Mac = [u8; 6];
-
-pub fn debug() {
-    for input in [
-        [0, 0, 0, 0, 0, 0],
-        [0, 0, 0, 0, 0, 1],
-        [1, 0, 0, 0, 0, 0],
-        [1, 0, 0, 0, 0, 1],
-    ] {
-        assert_eq!(unmix(mix(input)), input);
-    }
-
-    println!("Passed");
-}
-
-// NOT intended for any cryptography or security. This is TRIVIALLY reversible.
-// It's just to make it easier for humans to tell apart MACs where only a couple
-// numbers differ.
-
-fn mix(i: Mac) -> Mac {
-    [i[0] ^ i[5], i[1] ^ i[4], i[2] ^ i[3], i[3], i[4], i[5]]
-}
-
-fn unmix(i: Mac) -> Mac {
-    [i[0] ^ i[5], i[1] ^ i[4], i[2] ^ i[3], i[3], i[4], i[5]]
-}

src/client.rs

@@ -165,9 +165,9 @@ fn configure_client<I: Iterator<Item = String>>(mut args: I) -> Result<ClientPar
 fn load_config_file() -> ConfigFile {
     let mut nicknames: HashMap<String, String> = Default::default();
 
-    if let Some(proj_dirs) = find_project_dirs() {
+    if let Some(dir) = app_common::try_config_dir() {
+        let path = dir.join("client.ini");
         let mut ini = Ini::new_cs();
-        let path = proj_dirs.config_local_dir().join("client.ini");
         if ini.load(&path).is_ok() {
             let map_ref = ini.get_map_ref();
             if let Some(x) = map_ref.get("nicknames") {

src/install.rs

@@ -0,0 +1,83 @@
+use crate::prelude::*;
+use anyhow::{Context as _, Result, anyhow, ensure};
+use std::{io::Write as _, process::Command};
+
+pub(crate) fn main(nickname: Option<&str>) -> Result<()> {
+    if let Some(nickname) = nickname {
+        let path = app_common::try_server_config_path().context("can't find config dir")?;
+        let text = format!(
+            "[server]
+nickname = {nickname}
+"
+        );
+
+        write_new(&path, &text).context("Didn't install LookAround server.ini")?;
+    }
+
+    setup_autostart()?;
+
+    Ok(())
+}
+
+#[cfg(not(target_os = "linux"))]
+fn setup_autostart() -> Result<()> {
+    anyhow::bail!("LookAround autostart is only implemented for systemd + GNU/Linux");
+}
+
+#[cfg(target_os = "linux")]
+fn setup_autostart() -> Result<()> {
+    let dirs = directories::BaseDirs::new().context("Could not find home dir")?;
+    let home = dirs.config_local_dir();
+    let path = home.join("systemd").join("user").join("lookaround.service");
+
+    let exe_path =
+        Utf8PathBuf::from_path_buf(std::env::current_exe().context("Can't get current_exe")?)
+            .map_err(|_| anyhow!("current_exe isn't valid UTF-8"))?;
+    let text = format!(
+        "[Unit]
+Description=LookAround
+
+[Service]
+ExecStart={exe_path} server
+Restart=always
+
+[Install]
+WantedBy=default.target
+"
+    );
+
+    write_new(&path, &text).context("Didn't install systemd service unit")?;
+
+    ensure!(
+        Command::new("systemctl")
+            .args(["--user", "start", "lookaround"])
+            .status()?
+            .success(),
+        "starting service failed"
+    );
+    ensure!(
+        Command::new("systemctl")
+            .args(["--user", "enable", "lookaround"])
+            .status()?
+            .success(),
+        "enabling service failed"
+    );
+
+    Ok(())
+}
+
+fn write_new(path: &Path, content: &str) -> Result<()> {
+    use std::fs;
+    fs::create_dir_all(
+        path.parent()
+            .context("Impossible, path should always have a parent")?,
+    )?;
+    match fs::File::create_new(path) {
+        Err(err) if err.kind() == std::io::ErrorKind::AlreadyExists => {
+            eprintln!("File already exists, won't overwrite: `{path:?}`")
+        }
+        Err(err) => Err(err)?,
+        Ok(mut f) => f.write_all(content.as_bytes())?,
+    }
+    Ok(())
+}

src/main.rs

@@ -1,15 +1,16 @@
+use anyhow::{Result, bail};
 use prelude::*;
 
 pub mod app_common;
-mod avalanche;
 mod client;
+mod install;
 mod ip;
 pub mod message;
 mod prelude;
 mod server;
 pub mod tlv;
 
-fn main() -> Result<(), AppError> {
+fn main() -> Result<()> {
     let rt = tokio::runtime::Builder::new_current_thread()
         .enable_io()
         .enable_time()
@@ -20,31 +21,38 @@ fn main() -> Result<(), AppError> {
     Ok(())
 }
 
-async fn async_main() -> Result<(), AppError> {
+async fn async_main() -> Result<()> {
     let mut args = env::args();
 
     let _exe_name = args.next();
 
-    let subcommand: Option<String> = args.next();
+    let Some(subcommand) = args.next() else {
+        return Err(CliArgError::MissingSubcommand.into());
+    };
 
-    match subcommand.as_ref().map(|x| &x[..]) {
-        None => return Err(CliArgError::MissingSubcommand.into()),
-        Some("--version") => println!("lookaround v{}", LOOKAROUND_VERSION),
-        Some("client") => client::client(args).await?,
-        Some("config") => config(),
-        Some("debug-avalanche") => avalanche::debug(),
-        Some("find-nick") => client::find_nick(args).await?,
-        Some("my-ips") => my_ips()?,
-        Some("server") => server::server(args).await?,
-        Some(x) => return Err(CliArgError::UnknownSubcommand(x.to_string()).into()),
+    match subcommand.as_ref() {
+        "--version" => {
+            println!("lookaround v{}", env!("CARGO_PKG_VERSION"));
+        }
+        "client" => client::client(args).await?,
+        "config" => {
+            config();
+        }
+        "find-nick" => client::find_nick(args).await?,
+        "install" => {
+            let nickname = args.next();
+            install::main(nickname.as_deref())?
+        }
+        "my-ips" => my_ips()?,
+        "server" => server::server(args).await?,
+        x => bail!("Unknown subcommand `{x}`"),
     }
-
     Ok(())
 }
 
 fn config() {
-    if let Some(proj_dirs) = ProjectDirs::from("", "ReactorScram", "LookAround") {
-        println!("Using config dir {:?}", proj_dirs.config_local_dir());
+    if let Some(dir) = app_common::try_config_dir() {
+        println!("config dir = `{dir:?}`");
     } else {
         println!("Can't detect config dir.");
     }

src/message.rs

@@ -198,7 +198,7 @@ mod test {
                 }],
                 vec![
                     154, 74, 67, 129, // Request tag
-                    1, // Idem ID
+                    1,   // Idem ID
                     1, 2, 3, 4, 5, 6, 7, 8, // MAC is None
                     0,
                 ],
@@ -214,10 +214,10 @@ mod test {
                 vec![
                     // Magic number for LookAround packets
                     154, 74, 67, 129, // Response1 tag
-                    2, // MAC is Some
-                    1, // MAC
+                    2,   // MAC is Some
+                    1,   // MAC
                     17, 34, 51, 68, 85, 102, // Response2 tag
-                    3, // Length prefix
+                    3,   // Length prefix
                     14, 0, 0, 0, // Idem ID
                     1, 2, 3, 4, 5, 6, 7, 8, // Length-prefixed string
                     2, 0, 0, 0, 58, 86,
@@ -241,7 +241,7 @@ mod test {
                 },
                 vec![
                     154, 74, 67, 129, // Request tag
-                    1, // Idem ID
+                    1,   // Idem ID
                     1, 2, 3, 4, 5, 6, 7, 8, // MAC is None
                     0,
                 ],
@@ -251,8 +251,8 @@ mod test {
                 vec![
                     // Magic number for LookAround packets
                     154, 74, 67, 129, // Response tag
-                    2, // MAC is Some
-                    1, // MAC
+                    2,   // MAC is Some
+                    1,   // MAC
                     17, 34, 51, 68, 85, 102,
                 ],
             ),
@@ -261,7 +261,7 @@ mod test {
                 vec![
                     // Magic number for LookAround packets
                     154, 74, 67, 129, // Response tag
-                    2, // MAC is None
+                    2,   // MAC is None
                     0,
                 ],
             ),

src/prelude.rs

@@ -3,13 +3,14 @@ pub use std::{
     env,
     io::{Cursor, Write},
     net::{Ipv4Addr, SocketAddr, SocketAddrV4},
+    path::{Path, PathBuf},
     str::FromStr,
     sync::Arc,
     time::Duration,
 };
 
+pub use camino::Utf8PathBuf;
 pub use configparser::ini::Ini;
-pub use directories::ProjectDirs;
 pub use mac_address::{MacAddress, get_mac_address};
 pub use rand::RngCore;
 pub use tokio::{
@@ -18,9 +19,7 @@ pub use tokio::{
 };
 
 pub use crate::{
-    app_common::{
-        self, AppError, CliArgError, LOOKAROUND_VERSION, find_project_dirs, recv_msg_from,
-    },
+    app_common::{self, AppError, CliArgError, recv_msg_from},
     ip::get_ips,
     message::{self, Message, PACKET_SIZE},
     tlv,

src/server.rs

@@ -42,11 +42,10 @@ pub async fn server<I: Iterator<Item = String>>(args: I) -> Result<(), AppError>
 fn configure<I: Iterator<Item = String>>(mut args: I) -> Result<Params, AppError> {
     let common = app_common::Params::default();
     let mut bind_addrs = vec![];
-    let mut nickname = String::new();
+    let mut nickname = sys_info::hostname().unwrap_or_default();
 
-    if let Some(proj_dirs) = find_project_dirs() {
+    if let Some(path) = app_common::try_server_config_path() {
         let mut ini = Ini::new_cs();
-        let path = proj_dirs.config_local_dir().join("server.ini");
         if ini.load(&path).is_ok() {
             if let Some(x) = ini.get("server", "nickname") {
                 nickname = x;