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|
// Reboot and rollback logic
// /data/update does not exist? => MONITOR
// CHECK:
// Connection to tcp!ipv4.google.com!80 unsuccessful? => FAIL
// Connection to tcp!ipv6.google.com!80 unsuccessful? => FAIL
// No connection from updater? => FAIL
// => MONITOR
// FAIL:
// If 5m passed since first CHECK? => TIMEOUT
// Wait 30s => CHECK
// TIMEOUT:
// Trigger rollback (can use /data/admind.passwd) => REBOOT
// MONITOR:
// Connection to tcp!ipv4.google.com!80 unsuccessful? => DROPOUT
// Connection to tcp!ipv6.google.com!80 unsuccessful? => DROPOUT
// Wait 5m => MONITOR
// DROPOUT:
// If DROPOUT for 1h? => REBOOT
// Wait 5m => MONITOR
use std::fs;
use std::io::{self, Read, Write};
use std::net::{Shutdown, SocketAddr, TcpListener, TcpStream};
use std::time::{Duration, Instant};
const UPDATE_FILE: &str = "/data/update";
const LISTEN_SOCKET: &str = "[::]:12808";
const MAGIC: [u8; 4] = [0x32, 0x7f, 0xfe, 0x4c];
const RESP_OK: [u8; 5] = [0x32, 0x7f, 0xfe, 0x4c, 0x00];
const RESP_NORMAL: [u8; 5] = [0x32, 0x7f, 0xfe, 0x4c, 0x01];
const CHECK_INTERVAL: Duration = Duration::from_secs(30);
const CHECK_TIMEOUT: Duration = Duration::from_secs(300);
const MONITOR_INTERVAL: Duration = Duration::from_secs(600);
const MONITOR_TIMEOUT: Duration = Duration::from_secs(3600);
const TCP_TIMEOUT: Duration = Duration::from_secs(8);
const POLL_INTERVAL: Duration = Duration::from_millis(500);
const PING_V4: &str = "1.1.1.1:80";
const PING_V6: &str = "[2606:4700:4700::1111]:80";
fn main() {
println!("[info] init");
match run() {
Ok(_) => eprintln!("[warn] logic terminated unexpectedly"),
Err(e) => eprintln!("[warn] {}", e),
}
}
fn run() -> io::Result<()> {
let ln = TcpListener::bind(LISTEN_SOCKET)?;
ln.set_nonblocking(true)?;
if fs::exists(UPDATE_FILE)? {
eprintln!("[info] update detected");
check_rollback(&ln)?;
eprintln!("[info] no rollback needed");
} else {
println!("[info] no update, skipping rollback check");
}
monitor(&ln)
}
fn check_rollback(ln: &TcpListener) -> io::Result<()> {
let mut outbound_healthy_v4 = false;
let mut outbound_healthy_v6 = false;
let mut inbound_healthy = false;
let t_start = Instant::now();
let mut t = t_start;
loop {
match ln.accept() {
Ok((conn, raddr)) => match handle_conn_check(conn, raddr, &mut inbound_healthy) {
Ok(_) => {}
Err(e) => eprintln!("[warn] handle (rollback) {}: {}", raddr, e),
},
Err(e) if e.kind() == io::ErrorKind::WouldBlock => {}
Err(e) => return Err(e),
}
let now = Instant::now();
if now.duration_since(t) >= CHECK_INTERVAL {
check_connectivity(&mut outbound_healthy_v4, &mut outbound_healthy_v6)?;
t = now;
}
if outbound_healthy_v4 && outbound_healthy_v6 && inbound_healthy {
break;
}
if now.duration_since(t_start) >= CHECK_TIMEOUT {
eprintln!(
"rollback, IPv4: {}, IPv6: {}, inbound: {}",
if outbound_healthy_v4 { "OK" } else { "ERR" },
if outbound_healthy_v6 { "OK" } else { "ERR" },
if inbound_healthy { "OK" } else { "ERR" }
);
return rollback();
}
std::thread::sleep(POLL_INTERVAL);
}
Ok(())
}
fn monitor(ln: &TcpListener) -> io::Result<()> {
let mut t_healthy = Instant::now();
let mut t = t_healthy;
loop {
match ln.accept() {
Ok((conn, raddr)) => match handle_conn_monitor(conn, raddr) {
Ok(_) => {}
Err(e) => eprintln!("[warn] handle (monitor) {}: {}", raddr, e),
},
Err(e) if e.kind() == io::ErrorKind::WouldBlock => {}
Err(e) => return Err(e),
}
let mut outbound_healthy_v4 = false;
let mut outbound_healthy_v6 = false;
let now = Instant::now();
if now.duration_since(t) >= MONITOR_INTERVAL {
check_connectivity(&mut outbound_healthy_v4, &mut outbound_healthy_v6)?;
t = now;
}
if outbound_healthy_v4 && outbound_healthy_v6 {
t_healthy = now;
continue;
}
if now.duration_since(t_healthy) >= MONITOR_TIMEOUT {
return reboot();
}
std::thread::sleep(POLL_INTERVAL);
}
}
fn handle_conn_check(
mut conn: TcpStream,
raddr: SocketAddr,
inbound_healthy: &mut bool,
) -> io::Result<()> {
conn.set_read_timeout(Some(TCP_TIMEOUT))?;
conn.set_write_timeout(Some(TCP_TIMEOUT))?;
let mut buf = [0; 4];
loop {
match conn.read_exact(&mut buf) {
Ok(_) => break,
Err(e) if e.kind() == io::ErrorKind::WouldBlock => {}
Err(e) => return Err(e),
}
}
if buf != MAGIC {
eprintln!("[warn] handle {raddr}: bad magic {buf:?}");
return Ok(());
}
*inbound_healthy = true;
conn.write_all(&RESP_OK)?;
conn.shutdown(Shutdown::Both)?;
println!("[info] inbound: {raddr}");
Ok(())
}
fn handle_conn_monitor(mut conn: TcpStream, raddr: SocketAddr) -> io::Result<()> {
conn.set_read_timeout(Some(TCP_TIMEOUT))?;
conn.set_write_timeout(Some(TCP_TIMEOUT))?;
let mut buf = [0; 4];
loop {
match conn.read_exact(&mut buf) {
Ok(_) => break,
Err(e) if e.kind() == io::ErrorKind::WouldBlock => {}
Err(e) => return Err(e),
}
}
if buf != MAGIC {
eprintln!("[warn] handle {raddr}: bad magic {buf:?}");
return Ok(());
}
conn.write_all(&RESP_NORMAL)?;
conn.shutdown(Shutdown::Both)?;
println!("[info] redundant inbound: {raddr}");
Ok(())
}
fn check_connectivity(
outbound_healthy_v4: &mut bool,
outbound_healthy_v6: &mut bool,
) -> io::Result<()> {
let mut buf = [0; 1024];
let conn4 =
match TcpStream::connect_timeout(&PING_V4.parse().expect("PING_V4 invalid"), TCP_TIMEOUT) {
Ok(conn) => Some(conn),
Err(e) => {
eprintln!("[warn] IPv4: connect: {}", e);
*outbound_healthy_v4 = false;
None
}
};
if let Some(mut conn4) = conn4 {
conn4.set_read_timeout(Some(TCP_TIMEOUT))?;
conn4.set_write_timeout(Some(TCP_TIMEOUT))?;
conn4.write_all(b"GET / HTTP/1.1\n\n").ok();
loop {
match conn4.read(&mut buf) {
Ok(0) => {
eprintln!("[warn] IPv4: connection closed");
*outbound_healthy_v4 = false;
}
Ok(_) => {
*outbound_healthy_v4 = true;
}
Err(e) if e.kind() == io::ErrorKind::WouldBlock => continue,
Err(e) => {
eprintln!("[warn] IPv4: read: {}", e);
*outbound_healthy_v4 = false;
}
}
break;
}
conn4.shutdown(Shutdown::Both).ok();
}
let conn6 =
match TcpStream::connect_timeout(&PING_V6.parse().expect("PING_V6 invalid"), TCP_TIMEOUT) {
Ok(conn) => Some(conn),
Err(e) => {
eprintln!("[warn] IPv6: connect: {}", e);
*outbound_healthy_v6 = false;
None
}
};
if let Some(mut conn6) = conn6 {
conn6.set_read_timeout(Some(TCP_TIMEOUT))?;
conn6.set_write_timeout(Some(TCP_TIMEOUT))?;
conn6.write_all(b"GET / HTTP/1.1\n\n").ok();
loop {
match conn6.read(&mut buf) {
Ok(0) => {
eprintln!("[warn] IPv6: connection closed");
*outbound_healthy_v6 = false;
}
Ok(_) => {
*outbound_healthy_v6 = true;
}
Err(e) if e.kind() == io::ErrorKind::WouldBlock => continue,
Err(e) => {
eprintln!("[warn] IPv6: read: {}", e);
*outbound_healthy_v6 = false;
}
}
break;
}
conn6.shutdown(Shutdown::Both).ok();
}
Ok(())
}
fn rollback() -> io::Result<()> {
todo!()
}
fn reboot() -> io::Result<()> {
todo!()
}
|
