Add support for default route (IPv4 and IPv6) (#2059)

Based on code by Michael Birtwell <michael.birtwell@oxionics.com>

artiq/firmware/bootloader/main.rs

@@ -18,8 +18,8 @@ use board_misoc::slave_fpga;
 use board_misoc::{clock, ethmac, net_settings};
 use board_misoc::uart_console::Console;
 use riscv::register::{mcause, mepc, mtval};
-use smoltcp::iface::SocketStorage;
-use smoltcp::wire::{HardwareAddress, IpAddress, Ipv4Address};
+use smoltcp::iface::{Routes, SocketStorage};
+use smoltcp::wire::{HardwareAddress, IpAddress, Ipv4Address, Ipv6Address};
 
 fn check_integrity() -> bool {
     extern {
@@ -411,28 +411,29 @@ fn network_boot() {
     println!("Network addresses: {}", net_addresses);
     let mut ip_addrs = [
         IpCidr::new(IpAddress::Ipv4(Ipv4Address::UNSPECIFIED), 0),
-        IpCidr::new(net_addresses.ipv6_ll_addr, 0),
-        IpCidr::new(net_addresses.ipv6_ll_addr, 0)
+        net_addresses.ipv6_ll_addr,
+        IpCidr::new(IpAddress::Ipv6(Ipv6Address::UNSPECIFIED), 0)
     ];
     if let net_settings::Ipv4AddrConfig::Static(ipv4) = net_addresses.ipv4_addr {
-        ip_addrs[0] = IpCidr::new(IpAddress::Ipv4(ipv4), 0);
+        ip_addrs[0] = IpCidr::Ipv4(ipv4);
     }
-    let mut interface = match net_addresses.ipv6_addr {
-        Some(addr) => {
-            ip_addrs[2] = IpCidr::new(addr, 0);
-            smoltcp::iface::InterfaceBuilder::new(net_device, &mut sockets[..])
-                       .hardware_addr(HardwareAddress::Ethernet(net_addresses.hardware_addr))
-                       .ip_addrs(&mut ip_addrs[..])
-                       .neighbor_cache(neighbor_cache)
-                       .finalize()
-        }
-        None =>
-            smoltcp::iface::InterfaceBuilder::new(net_device, &mut sockets[..])
-                       .hardware_addr(HardwareAddress::Ethernet(net_addresses.hardware_addr))
-                       .ip_addrs(&mut ip_addrs[..2])
-                       .neighbor_cache(neighbor_cache)
-                       .finalize()
+    if let Some(ipv6) =  net_addresses.ipv6_addr {
+        ip_addrs[2] = IpCidr::Ipv6(ipv6);
     };
+    let mut routes = [None; 2];
+    let mut interface = smoltcp::iface::InterfaceBuilder::new(net_device, &mut sockets[..])
+        .hardware_addr(HardwareAddress::Ethernet(net_addresses.hardware_addr))
+        .ip_addrs(&mut ip_addrs[..])
+        .neighbor_cache(neighbor_cache)
+        .routes(Routes::new(&mut routes[..]))
+        .finalize();
+
+    if let Some(default_route) = net_addresses.ipv4_default_route {
+        interface.routes_mut().add_default_ipv4_route(default_route).unwrap();
+    }
+    if let Some(default_route) = net_addresses.ipv6_default_route {
+        interface.routes_mut().add_default_ipv6_route(default_route).unwrap();
+    }
 
     let mut rx_storage = [0; 4096];
     let mut tx_storage = [0; 128];

artiq/firmware/libboard_misoc/net_settings.rs

@@ -2,7 +2,7 @@ use core::fmt;
 use core::fmt::{Display, Formatter};
 use core::str::FromStr;
 
-use smoltcp::wire::{EthernetAddress, IpAddress, Ipv4Address};
+use smoltcp::wire::{EthernetAddress, IpAddress, IpCidr, Ipv4Address, Ipv4Cidr, Ipv6Address, Ipv6Cidr};
 
 use config;
 #[cfg(soc_platform = "kasli")]
@@ -10,18 +10,22 @@ use i2c_eeprom;
 
 pub enum Ipv4AddrConfig {
     UseDhcp,
-    Static(Ipv4Address),
+    Static(Ipv4Cidr),
 }
 
 impl FromStr for Ipv4AddrConfig {
     type Err = ();
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Ok(if s == "use_dhcp" {
-            Ipv4AddrConfig::UseDhcp
+        if s == "use_dhcp" {
+            Ok(Ipv4AddrConfig::UseDhcp)
+        } else if let Ok(cidr) = Ipv4Cidr::from_str(s) {
+            Ok(Ipv4AddrConfig::Static(cidr))
+        } else if let Ok(addr) = Ipv4Address::from_str(s) {
+            Ok(Ipv4AddrConfig::Static(Ipv4Cidr::new(addr, 0)))
         } else {
-            Ipv4AddrConfig::Static(Ipv4Address::from_str(s)?)
-        })
+            Err(())
+        }
     }
 }
 
@@ -38,8 +42,10 @@ impl Display for Ipv4AddrConfig {
 pub struct NetAddresses {
     pub hardware_addr: EthernetAddress,
     pub ipv4_addr: Ipv4AddrConfig,
-    pub ipv6_ll_addr: IpAddress,
-    pub ipv6_addr: Option<IpAddress>
+    pub ipv6_ll_addr: IpCidr,
+    pub ipv6_addr: Option<Ipv6Cidr>,
+    pub ipv4_default_route: Option<Ipv4Address>,
+    pub ipv6_default_route: Option<Ipv6Address>,
 }
 
 impl fmt::Display for NetAddresses {
@@ -72,28 +78,39 @@ pub fn get_adresses() -> NetAddresses {
         }
     }
 
-    let ipv4_addr;
-    match config::read_str("ip", |r| r.map(|s| s.parse())) {
-        Ok(Ok(addr)) => ipv4_addr = addr,
-        _ => ipv4_addr = Ipv4AddrConfig::UseDhcp,
-    }
+    let ipv4_addr = match config::read_str("ip", |r| r.map(|s| s.parse())) {
+        Ok(Ok(addr)) => addr,
+        _ => Ipv4AddrConfig::UseDhcp,
+    };
 
-    let ipv6_ll_addr = IpAddress::v6(
+    let ipv4_default_route = match config::read_str("ipv4_default_route", |r| r.map(|s| s.parse())) {
+        Ok(Ok(addr)) => Some(addr),
+        _ => None,
+    };
+
+    let ipv6_ll_addr = IpCidr::new(IpAddress::v6(
         0xfe80, 0x0000, 0x0000, 0x0000,
         (((hardware_addr.0[0] ^ 0x02) as u16) << 8) | (hardware_addr.0[1] as u16),
         ((hardware_addr.0[2] as u16) << 8) | 0x00ff,
         0xfe00 | (hardware_addr.0[3] as u16),
-        ((hardware_addr.0[4] as u16) << 8) | (hardware_addr.0[5] as u16));
+        ((hardware_addr.0[4] as u16) << 8) | (hardware_addr.0[5] as u16)), 10);
 
     let ipv6_addr = match config::read_str("ip6", |r| r.map(|s| s.parse())) {
         Ok(Ok(addr)) => Some(addr),
         _ => None
     };
 
+    let ipv6_default_route = match config::read_str("ipv6_default_route", |r| r.map(|s| s.parse())) {
+        Ok(Ok(addr)) => Some(addr),
+        _ => None,
+    };
+
     NetAddresses {
-        hardware_addr: hardware_addr,
-        ipv4_addr: ipv4_addr,
-        ipv6_ll_addr: ipv6_ll_addr,
-        ipv6_addr: ipv6_addr
+        hardware_addr,
+        ipv4_addr,
+        ipv6_ll_addr,
+        ipv6_addr,
+        ipv4_default_route,
+        ipv6_default_route,
     }
 }

artiq/firmware/runtime/dhcp.rs

@@ -1,12 +1,25 @@
 use board_misoc::clock;
 use sched;
 use sched::Dhcpv4Socket;
-use smoltcp::socket::Dhcpv4Event;
+use core::fmt::{Display, Formatter};
+use smoltcp::socket::{Dhcpv4Config, Dhcpv4Event};
 use smoltcp::wire::{Ipv4Address, Ipv4Cidr};
 
+struct OptionalIpAddressDisplay<'a> (&'a Option<Ipv4Address>);
+
+impl<'a> Display for OptionalIpAddressDisplay<'a> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> core::fmt::Result {
+        match self.0 {
+            Some(ip) => write!(f, "{}", ip),
+            None => write!(f, "<not set>"),
+        }
+    }
+}
+
+
 pub fn dhcp_thread(io: sched::Io) {
     let mut socket = Dhcpv4Socket::new(&io);
-    let mut last_ip: Option<Ipv4Cidr> = None;
+    let mut last_config: Option<Dhcpv4Config> = None;
     let mut done_reset = false;
     let start_time = clock::get_ms();
 
@@ -15,8 +28,8 @@ pub fn dhcp_thread(io: sched::Io) {
         // by the server. This is likely to be because the ethernet device isn't quite
         // ready at the point that it is sent. The following makes recovery from
         // that faster.
-        if !done_reset && last_ip.is_none() && start_time + 1000 < clock::get_ms() {
-            info!("Didn't get initial IP in first second. Assuming packet loss, trying a reset.");
+        if !done_reset && last_config.is_none() && start_time + 1000 < clock::get_ms() {
+            info!("Didn't get initial config in first second. Assuming packet loss, trying a reset.");
             socket.reset();
             done_reset = true;
         }
@@ -26,27 +39,45 @@ pub fn dhcp_thread(io: sched::Io) {
                     // Only compare the ip address in the config with previous config because we
                     // ignore the rest of the config i.e. we don't do any DNS or require a default
                     // gateway.
-                    let changed = if let Some(last_ip) = last_ip {
-                        if config.address != last_ip {
-                            info!("IP address changed {} -> {}", last_ip, config.address);
-                            true
-                        } else {
-                            false
+                    let changed = if let Some(last_config) = last_config {
+                        let mut changed = false;
+                        if config.address != last_config.address {
+                            info!("IP address changed {} -> {}", last_config.address, config.address);
+                            changed = true;
                         }
+                        if config.router != last_config.router {
+                            info!("Default route changed {} -> {}",
+                                OptionalIpAddressDisplay(&last_config.router),
+                                OptionalIpAddressDisplay(&config.router),
+                            );
+                            changed = true;
+                        }
+                        changed
                     } else {
-                        info!("Acquired IP address: None -> {}", config.address);
+                        info!("Acquired DHCP config IP address: None -> {} default route: None -> {}",
+                            config.address,
+                            OptionalIpAddressDisplay(&config.router),
+                        );
                         true
                     };
                     if changed {
-                        last_ip = Some(config.address);
+                        last_config = Some(config);
                         io.set_ipv4_address(&config.address);
+                        match config.router {
+                            Some(route) => { io.set_ipv4_default_route(route).unwrap(); }
+                            None => { io.remove_ipv4_default_route(); }
+                        }
                     }
                 }
                 Dhcpv4Event::Deconfigured => {
-                    if let Some(ip) = last_ip {
-                        info!("Lost IP address {} -> None", ip);
+                    if let Some(config) = last_config {
+                        info!("Lost DHCP config IP address {} -> None; default route {} -> None",
+                            config.address,
+                            OptionalIpAddressDisplay(&config.router),
+                        );
                         io.set_ipv4_address(&Ipv4Cidr::new(Ipv4Address::UNSPECIFIED, 0));
-                        last_ip = None;
+                        io.remove_ipv4_default_route();
+                        last_config = None;
                     }
                     // We always get one of these events at the start, ignore that one
                 }

artiq/firmware/runtime/ip_addr_storage.rs

@@ -1,6 +1,6 @@
 use smoltcp::iface::{Interface, InterfaceBuilder};
 use smoltcp::phy::Device;
-use smoltcp::wire::{IpAddress, IpCidr, Ipv4Address, Ipv4Cidr};
+use smoltcp::wire::{IpAddress, IpCidr, Ipv4Address, Ipv4Cidr, Ipv6Cidr};
 use board_misoc::net_settings::{Ipv4AddrConfig, NetAddresses};
 
 
@@ -16,14 +16,14 @@ pub trait InterfaceBuilderEx {
 impl<'a, DeviceT: for<'d> Device<'d>> InterfaceBuilderEx for InterfaceBuilder<'a, DeviceT> {
     fn init_ip_addrs(self, net_addresses: &NetAddresses) -> Self {
         let mut storage = [
-            IpCidr::new(IpAddress::Ipv4(Ipv4Address::UNSPECIFIED), 0);  IP_ADDRESS_STORAGE_SIZE
+            IpCidr::new(IpAddress::Ipv4(Ipv4Address::UNSPECIFIED), 32);  IP_ADDRESS_STORAGE_SIZE
         ];
         if let Ipv4AddrConfig::Static(ipv4) = net_addresses.ipv4_addr {
-            storage[IPV4_INDEX] = IpCidr::new(IpAddress::Ipv4(ipv4), 0);
+            storage[IPV4_INDEX] = IpCidr::Ipv4(ipv4);
         }
-        storage[IPV6_LL_INDEX] = IpCidr::new(net_addresses.ipv6_ll_addr, 0);
+        storage[IPV6_LL_INDEX] = net_addresses.ipv6_ll_addr;
         if let Some(ipv6) = net_addresses.ipv6_addr {
-            storage[IPV6_INDEX] = IpCidr::new(ipv6, 0);
+            storage[IPV6_INDEX] = IpCidr::Ipv6(ipv6);
         }
         self.ip_addrs(storage)
     }
@@ -31,10 +31,14 @@ impl<'a, DeviceT: for<'d> Device<'d>> InterfaceBuilderEx for InterfaceBuilder<'a
 
 pub trait InterfaceEx {
     fn update_ipv4_addr(&mut self, addr: &Ipv4Cidr);
+    fn update_ipv6_addr(&mut self, addr: &Ipv6Cidr);
 }
 
 impl<'a, DeviceT: for<'d> Device<'d>> InterfaceEx for Interface<'a, DeviceT> {
     fn update_ipv4_addr(&mut self, addr: &Ipv4Cidr) {
         self.update_ip_addrs(|storage| storage[IPV4_INDEX] = IpCidr::Ipv4(*addr))
     }
+    fn update_ipv6_addr(&mut self, addr: &Ipv6Cidr) {
+        self.update_ip_addrs(|storage| storage[IPV6_INDEX] = IpCidr::Ipv6(*addr))
+    }
 }

artiq/firmware/runtime/main.rs

@@ -25,6 +25,7 @@ extern crate logger_artiq;
 extern crate proto_artiq;
 extern crate riscv;
 
+use alloc::collections::BTreeMap;
 use core::cell::RefCell;
 use core::convert::TryFrom;
 use smoltcp::wire::HardwareAddress;
@@ -42,6 +43,7 @@ use proto_artiq::{mgmt_proto, moninj_proto, rpc_proto, session_proto, kernel_pro
 use proto_artiq::analyzer_proto;
 
 use riscv::register::{mcause, mepc, mtval};
+use smoltcp::iface::Routes;
 use ip_addr_storage::InterfaceBuilderEx;
 
 mod rtio_clocking;
@@ -151,12 +153,23 @@ fn startup() {
     } else {
         false
     };
-    let interface = smoltcp::iface::InterfaceBuilder::new(net_device, vec![])
+    let mut interface = smoltcp::iface::InterfaceBuilder::new(net_device, vec![])
         .hardware_addr(HardwareAddress::Ethernet(net_addresses.hardware_addr))
         .init_ip_addrs(&net_addresses)
         .neighbor_cache(neighbor_cache)
+        .routes(Routes::new(BTreeMap::new()))
         .finalize();
 
+    if !use_dhcp {
+        if let Some(ipv4_default_route) = net_addresses.ipv4_default_route {
+            interface.routes_mut().add_default_ipv4_route(ipv4_default_route).unwrap();
+        }
+    }
+
+    if let Some(ipv6_default_route) = net_addresses.ipv6_default_route {
+        interface.routes_mut().add_default_ipv6_route(ipv6_default_route).unwrap();
+    }
+
     #[cfg(has_drtio)]
     let drtio_routing_table = urc::Urc::new(RefCell::new(
         drtio_routing::config_routing_table(csr::DRTIO.len())));

artiq/firmware/runtime/sched.rs

@@ -8,8 +8,8 @@ use fringe::OwnedStack;
 use fringe::generator::{Generator, Yielder, State as GeneratorState};
 use smoltcp::time::Duration;
 use smoltcp::Error as NetworkError;
-use smoltcp::wire::{IpEndpoint, Ipv4Cidr};
-use smoltcp::iface::{Interface, SocketHandle};
+use smoltcp::wire::{IpEndpoint, Ipv4Address, Ipv4Cidr};
+use smoltcp::iface::{Interface, Route, SocketHandle};
 
 use io::{Read, Write};
 use board_misoc::clock;
@@ -278,6 +278,14 @@ impl<'a> Io<'a> {
     pub fn set_ipv4_address(&self, addr: &Ipv4Cidr) {
         self.network.borrow_mut().update_ipv4_addr(addr)
     }
+
+    pub fn set_ipv4_default_route(&self, addr: Ipv4Address) -> Result<Option<Route>, Error> {
+        Ok(self.network.borrow_mut().routes_mut().add_default_ipv4_route(addr)?)
+    }
+
+    pub fn remove_ipv4_default_route(&self) -> Option<Route> {
+        self.network.borrow_mut().routes_mut().remove_default_ipv4_route()
+    }
 }
 
 #[derive(Clone)]

doc/manual/installing.rst

@@ -284,19 +284,25 @@ If you purchased a Kasli device from M-Labs, it usually comes with the IP addres
 
 and then reboot the device (with ``artiq_flash start`` or a power cycle).
 
-If the ip config field is not set, or set to "use_dhcp" then the device will attempt to obtain an IP address using
-DHCP. If a static IP address is wanted, install OpenOCD as before, and flash the IP (and, if necessary, MAC) addresses
-directly: ::
+If the ``ip`` config field is not set, or set to ``use_dhcp`` then the device will
+attempt to obtain an IP address and default gateway using DHCP. If a static IP
+address is wanted, install OpenOCD as before, and flash the IP, default gateway
+(and, if necessary, MAC and IPv6) addresses directly: ::
 
-  $ artiq_mkfs flash_storage.img -s mac xx:xx:xx:xx:xx:xx -s ip xx.xx.xx.xx
+  $ artiq_mkfs flash_storage.img -s mac xx:xx:xx:xx:xx:xx -s ip xx.xx.xx.xx/xx -s ipv4_default_route xx.xx.xx.xx -s ip6 xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx/xx -s ipv6_default_route xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:xxxx
   $ artiq_flash -t [board] -V [variant] -f flash_storage.img storage start
 
 For Kasli devices, flashing a MAC address is not necessary as they can obtain it from their EEPROM.
+If you only want to access the core device from the same subnet you may
+omit the default gateway and IPv4 prefix length: ::
+
+  $ artiq_mkfs flash_storage.img -s mac xx:xx:xx:xx:xx:xx -s ip xx.xx.xx.xx
 
 If DHCP has been used the address can be found in the console output, which can be viewed using: ::
 
   $ python -m misoc.tools.flterm /dev/ttyUSB2
 
+
 Check that you can ping the device. If ping fails, check that the Ethernet link LED is ON - on Kasli, it is the LED next to the SFP0 connector. As a next step, look at the messages emitted on the UART during boot. Use a program such as flterm or PuTTY to connect to the device's serial port at 115200bps 8-N-1 and reboot the device. On Kasli, the serial port is on FTDI channel 2 with v1.1 hardware (with channel 0 being JTAG) and on FTDI channel 1 with v1.0 hardware. Note that on Windows you might need to install the `FTDI drivers <https://ftdichip.com/drivers/>`_ first.
 
 If you want to use IPv6, the device also has a link-local address that corresponds to its EUI-64, and an additional arbitrary IPv6 address can be defined by using the ``ip6`` configuration key. All IPv4 and IPv6 addresses can be used at the same time.