durnitisp/src/icmp.rs

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2020-12-24 15:48:50 -05:00
// Copyright 2020 Jeremy Wall
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use std::convert::Into;
use std::net::{IpAddr, SocketAddr};
use std::sync::{Arc, RwLock};
use std::time::{Duration, Instant};
use gflags;
use log::{debug, error, info};
use packet::icmp::echo::{Builder, Packet};
use packet::Builder as PBuilder;
use socket2::Domain;
use socket2::Protocol;
use socket2::SockAddr;
use socket2::Socket;
gflags::define! {
// The size in bytes of the ping requests.
--pingPayload = "durnitisp ping test"
}
fn make_echo_packet(ident: u16) -> Packet<Vec<u8>> {
let buffer = Builder::default()
.request()
.unwrap()
.identifier(ident)
.unwrap()
.sequence(0)
.unwrap()
.payload(PINGPAYLOAD.flag.as_bytes())
.unwrap()
.build()
.unwrap();
Packet::unchecked(buffer)
}
pub fn start_echo_loop(
domain_name: &str,
stop_signal: Arc<RwLock<bool>>,
addr: IpAddr,
ident: u16,
) {
info!("Starting ping of {}", domain_name);
// First we construct our icmp transport
// TODO(jwall): Timeouts.
// TODO(jwall): Handle out of order packets.
let (domain, protocol) = match addr {
IpAddr::V4(_) => (Domain::ipv4(), Protocol::icmpv4()),
IpAddr::V6(_) => (Domain::ipv6(), Protocol::icmpv6()),
};
// Construct a socket to send the ICMP request on.
// socket type: Ip, Datagram, ICMP
let addr: SocketAddr = (addr, 0).into();
let addr: SockAddr = addr.into();
let socket = match Socket::new(domain, socket2::Type::raw(), Some(protocol)) {
Ok(s) => s,
Err(e) => {
error!("Unable to create socket for icmp request:\n {}", e);
return;
}
};
socket
.set_read_timeout(Some(Duration::from_millis(2048)))
.unwrap();
// then we start our loop
let mut n = 0;
let mut pkt = make_echo_packet(ident);
loop {
{
// Limit the scope of this lock
if *stop_signal.read().unwrap() {
info!("Stopping ping thread for {}", domain_name);
return;
}
}
pkt.set_sequence(n).unwrap();
// TODO(jwall): Count the errors?
// construct echo packet
let time_of_send = Instant::now();
// send echo packet
let pkt_buf: &[u8] = pkt.as_ref();
debug!("Sending echo request for {}", domain_name);
let sent = socket.send_to(pkt_buf, &addr).unwrap();
if pkt_buf.len() != sent {
error!("Failed to send a complete icmp packet!");
continue;
}
// // Wait for echo response
debug!("Waiting for echo reply from {}", domain_name);
let mut buf = vec![0; sent];
let _rcv_size = match socket.recv(&mut buf) {
Ok(sz) => sz,
Err(e) => {
if let std::io::ErrorKind::TimedOut = e.kind() {
error!("icmp echo request timed out to {}", domain_name);
continue;
}
error!("Error recieving on icmp socket! {:?}", e);
return;
}
};
let echo = Packet::new(&buf).unwrap();
if echo.sequence() == n {
let round_trip_time = Instant::now().checked_duration_since(time_of_send).unwrap();
// record this time
info!("Sequence # {} {}ms", n, round_trip_time.as_millis());
} else {
error!("Got the wrong sequence number {}", echo.sequence());
}
// Increment our sequence number
n += 1;
}
}