feat(bluetooth-hid): 支持经典蓝牙 HID 后端

libs/bluetooth-hid/src/controller.rs

@@ -0,0 +1,135 @@
+//! Exclusive controller ownership. No BLE switching or power cycling.
+use std::{
+    fs::{File, OpenOptions},
+    os::{fd::AsRawFd, unix::fs::OpenOptionsExt},
+    process::Stdio,
+    time::Duration,
+};
+use tokio::process::Command;
+pub struct Controller {
+    _lock: File,
+    adapter: String,
+    old_class: (u8, u8),
+    old_connectable: bool,
+}
+async fn run_once(adapter: &str, args: &[&str]) -> Result<String, String> {
+    let mut cmd = Command::new("btmgmt");
+    cmd.arg("--index")
+        .arg(adapter.trim_start_matches("hci"))
+        .args(args)
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .kill_on_drop(true);
+    let mut child = cmd
+        .spawn()
+        .map_err(|e| format!("Install bluez/btmgmt: {e}"))?;
+    // BlueZ 5.55's btmgmt exits on stdin EOF, even with a command argument.
+    // Keep a pipe open until it finishes; systemd normally supplies /dev/null.
+    let stdin = child.stdin.take();
+    let result = tokio::time::timeout(Duration::from_secs(5), child.wait_with_output())
+        .await
+        .map_err(|_| "btmgmt timeout")?
+        .map_err(|e| format!("Install bluez/btmgmt: {e}"))?;
+    drop(stdin);
+    let text = String::from_utf8_lossy(&result.stdout).into_owned();
+    if !result.status.success()
+        || !result.stderr.is_empty()
+        || text.to_lowercase().contains("failed")
+    {
+        return Err(format!(
+            "btmgmt {}: {text} {}",
+            args.join(" "),
+            String::from_utf8_lossy(&result.stderr)
+        ));
+    }
+    Ok(text)
+}
+async fn run(adapter: &str, args: &[&str]) -> Result<String, String> {
+    // BlueZ updates the EIR/class asynchronously after registering SDP.
+    // Kernel management rejects a simultaneous class change with Busy.
+    for attempt in 0..5 {
+        match run_once(adapter, args).await {
+            Err(error) if error.contains("(Busy)") && attempt < 4 => {
+                tokio::time::sleep(Duration::from_millis(200)).await;
+            }
+            result => return result,
+        }
+    }
+    unreachable!()
+}
+impl Controller {
+    pub async fn acquire(adapter: &str) -> Result<Self, String> {
+        let lock = OpenOptions::new()
+            .read(true)
+            .write(true)
+            .create(true)
+            .truncate(false)
+            .mode(0o600)
+            .custom_flags(libc::O_NOFOLLOW)
+            .open(format!("/run/one-kvm-bluetooth-{adapter}.lock"))
+            .map_err(|e| e.to_string())?;
+        if unsafe { libc::flock(lock.as_raw_fd(), libc::LOCK_EX | libc::LOCK_NB) } != 0 {
+            return Err("Bluetooth adapter already owned by One-KVM".into());
+        }
+        let info = run(adapter, &["info"]).await?;
+        let settings = info
+            .lines()
+            .find_map(|l| l.trim().strip_prefix("current settings:"))
+            .ok_or("Cannot read Bluetooth settings")?;
+        if !settings.split_whitespace().any(|s| s == "br/edr") {
+            return Err(
+                "Classic Bluetooth disabled; enable BR/EDR with btmgmt before using HID".into(),
+            );
+        }
+        let class = info
+            .split_whitespace()
+            .skip_while(|s| *s != "class")
+            .nth(1)
+            .ok_or("Missing Bluetooth class")?;
+        let class =
+            u32::from_str_radix(class.trim_start_matches("0x"), 16).map_err(|e| e.to_string())?;
+        Ok(Self {
+            _lock: lock,
+            adapter: adapter.into(),
+            old_class: (((class >> 8) & 0x1f) as u8, (class & 0xfc) as u8),
+            old_connectable: settings.split_whitespace().any(|s| s == "connectable"),
+        })
+    }
+    pub async fn configure(&self) -> Result<(), String> {
+        run(&self.adapter, &["class", "5", "192"]).await?;
+        run(&self.adapter, &["connectable", "on"]).await?;
+        Ok(())
+    }
+    pub async fn restore(&self) -> Result<(), String> {
+        let mut errors = vec![];
+        if let Err(e) = run(
+            &self.adapter,
+            &[
+                "class",
+                &self.old_class.0.to_string(),
+                &self.old_class.1.to_string(),
+            ],
+        )
+        .await
+        {
+            errors.push(e);
+        }
+        if let Err(e) = run(
+            &self.adapter,
+            &[
+                "connectable",
+                if self.old_connectable { "on" } else { "off" },
+            ],
+        )
+        .await
+        {
+            errors.push(e);
+        }
+        if errors.is_empty() {
+            Ok(())
+        } else {
+            Err(errors.join("; "))
+        }
+    }
+}