Implement DHCPv4 client + example.

Author: astro

.travis.yml

@@ -19,6 +19,8 @@ matrix:
       env: FEATURES='std proto-ipv4 proto-igmp socket-raw' MODE='test'
     - rust: nightly
       env: FEATURES='std proto-ipv4 socket-udp socket-tcp' MODE='test'
+    - rust: nightly
+      env: FEATURES='std proto-ipv4 proto-dhcpv4 socket-udp' MODE='test'
     - rust: nightly
       env: FEATURES='std proto-ipv6 socket-udp' MODE='test'
     - rust: nightly
@@ -35,7 +37,7 @@ matrix:
       env: FEATURES='proto-ipv4 proto-ipv6 socket-raw socket-udp socket-tcp socket-icmp alloc'
         MODE='test'
     - rust: nightly
-      env: FEATURES='proto-ipv4 proto-ipv6 proto-igmp socket-raw socket-udp socket-tcp socket-icmp'
+      env: FEATURES='proto-ipv4 proto-ipv6 proto-igmp proto-dhcpv4 socket-raw socket-udp socket-tcp socket-icmp'
         MODE='build'
     - rust: nightly
       env: MODE='fuzz run' ARGS='packet_parser -- -max_len=1536 -max_total_time=30'

Cargo.toml

@@ -35,12 +35,12 @@ verbose = []
 "phy-tap_interface" = ["std", "libc"]
 "proto-ipv4" = []
 "proto-igmp" = ["proto-ipv4"]
+"proto-dhcpv4" = ["proto-ipv4", "socket-raw"]
 "proto-ipv6" = []
 "socket-raw" = []
 "socket-udp" = []
 "socket-tcp" = []
 "socket-icmp" = []
-"proto-dhcpv4" = ["proto-ipv4"]
 default = [
   "std", "log", # needed for `cargo test --no-default-features --features default` :/
   "phy-raw_socket", "phy-tap_interface",
@@ -88,5 +88,9 @@ required-features = ["std", "phy-tap_interface", "proto-ipv4", "proto-igmp", "so
 name = "benchmark"
 required-features = ["std", "phy-tap_interface", "proto-ipv4", "socket-raw", "socket-udp"]
 
+[[example]]
+name = "dhcp_client"
+required-features = ["std", "phy-tap_interface", "proto-ipv4", "proto-dhcpv4", "socket-raw"]
+
 [profile.release]
 debug = 2

examples/dhcp_client.rs

@@ -0,0 +1,106 @@
+#[macro_use]
+extern crate log;
+extern crate env_logger;
+extern crate getopts;
+extern crate smoltcp;
+
+mod utils;
+
+use std::collections::BTreeMap;
+use std::os::unix::io::AsRawFd;
+use smoltcp::phy::wait as phy_wait;
+use smoltcp::wire::{EthernetAddress, Ipv4Address, IpCidr, Ipv4Cidr};
+use smoltcp::iface::{NeighborCache, EthernetInterfaceBuilder, Routes};
+use smoltcp::socket::{SocketSet, RawSocketBuffer, RawPacketMetadata};
+use smoltcp::time::Instant;
+use smoltcp::dhcp::Dhcpv4Client;
+
+fn main() {
+    #[cfg(feature = "log")]
+    utils::setup_logging("");
+
+    let (mut opts, mut free) = utils::create_options();
+    utils::add_tap_options(&mut opts, &mut free);
+    utils::add_middleware_options(&mut opts, &mut free);
+
+    let mut matches = utils::parse_options(&opts, free);
+    let device = utils::parse_tap_options(&mut matches);
+    let fd = device.as_raw_fd();
+    let device = utils::parse_middleware_options(&mut matches, device, /*loopback=*/false);
+
+    let neighbor_cache = NeighborCache::new(BTreeMap::new());
+    let ethernet_addr = EthernetAddress([0x02, 0x00, 0x00, 0x00, 0x00, 0x01]);
+    let ip_addrs = [IpCidr::new(Ipv4Address::UNSPECIFIED.into(), 0)];
+    let mut routes_storage = [None; 1];
+    let routes = Routes::new(&mut routes_storage[..]);
+    let mut iface = EthernetInterfaceBuilder::new(device)
+            .ethernet_addr(ethernet_addr)
+            .neighbor_cache(neighbor_cache)
+            .ip_addrs(ip_addrs)
+            .routes(routes)
+            .finalize();
+
+    let mut sockets = SocketSet::new(vec![]);
+    let dhcp_rx_buffer = RawSocketBuffer::new(
+        [RawPacketMetadata::EMPTY; 1],
+        vec![0; 900]
+    );
+    let dhcp_tx_buffer = RawSocketBuffer::new(
+        [RawPacketMetadata::EMPTY; 1],
+        vec![0; 600]
+    );
+    let mut dhcp = Dhcpv4Client::new(&mut sockets, dhcp_rx_buffer, dhcp_tx_buffer, Instant::now());
+    let mut prev_cidr = Ipv4Cidr::new(Ipv4Address::UNSPECIFIED, 0);
+    loop {
+        let timestamp = Instant::now();
+        iface.poll(&mut sockets, timestamp)
+            .map(|_| ())
+            .unwrap_or_else(|e| println!("Poll: {:?}", e));
+        let config = dhcp.poll(&mut iface, &mut sockets, timestamp)
+            .unwrap_or_else(|e| {
+                println!("DHCP: {:?}", e);
+                None
+            });
+        config.map(|config| {
+            println!("DHCP config: {:?}", config);
+            match config.address {
+                Some(cidr) => if cidr != prev_cidr {
+                    iface.update_ip_addrs(|addrs| {
+                        addrs.iter_mut().nth(0)
+                            .map(|addr| {
+                                *addr = IpCidr::Ipv4(cidr);
+                            });
+                    });
+                    prev_cidr = cidr;
+                    println!("Assigned a new IPv4 address: {}", cidr);
+                }
+                _ => {}
+            }
+
+            config.router.map(|router| iface.routes_mut()
+                              .add_default_ipv4_route(router.into())
+                              .unwrap()
+            );
+            iface.routes_mut()
+                .update(|routes_map| {
+                    routes_map.get(&IpCidr::new(Ipv4Address::UNSPECIFIED.into(), 0))
+                        .map(|default_route| {
+                            println!("Default gateway: {}", default_route.via_router);
+                        });
+                });
+
+            if config.dns_servers.iter().any(|s| s.is_some()) {
+                println!("DNS servers:");
+                for dns_server in config.dns_servers.iter().filter_map(|s| *s) {
+                    println!("- {}", dns_server);
+                }
+            }
+        });
+
+        let mut timeout = dhcp.next_poll(timestamp);
+        iface.poll_delay(&sockets, timestamp)
+            .map(|sockets_timeout| timeout = sockets_timeout);
+        phy_wait(fd, Some(timeout))
+            .unwrap_or_else(|e| println!("Wait: {:?}", e));;
+    }
+}