utils, interface: introduce flag to identify broadcast-capable interf…

…aces

This is useful for protocols like IS-IS, which handle network I/O
differently for broadcast vs. point-to-point interfaces.

Signed-off-by: Renato Westphal <renato@opensourcerouting.org>

holo-interface/src/netlink.rs

@@ -13,8 +13,8 @@ use holo_utils::southbound::InterfaceFlags;
 use ipnetwork::IpNetwork;
 use netlink_packet_core::{NetlinkMessage, NetlinkPayload};
 use netlink_packet_route::constants::{
-    AF_INET, AF_INET6, ARPHRD_LOOPBACK, IFF_RUNNING, RTNLGRP_IPV4_IFADDR,
-    RTNLGRP_IPV6_IFADDR, RTNLGRP_LINK,
+    AF_INET, AF_INET6, ARPHRD_LOOPBACK, IFF_BROADCAST, IFF_RUNNING,
+    RTNLGRP_IPV4_IFADDR, RTNLGRP_IPV6_IFADDR, RTNLGRP_LINK,
 };
 use netlink_packet_route::rtnl::RtnlMessage;
 use netlink_packet_route::{AddressMessage, LinkMessage};
@@ -50,6 +50,9 @@ async fn process_newlink_msg(
     if msg.header.flags & IFF_RUNNING != 0 {
         flags.insert(InterfaceFlags::OPERATIVE);
     }
+    if msg.header.flags & IFF_BROADCAST != 0 {
+        flags.insert(InterfaceFlags::BROADCAST);
+    }
     for nla in msg.nlas.into_iter() {
         match nla {
             Nla::IfName(nla_ifname) => ifname = Some(nla_ifname),

holo-utils/src/southbound.rs

@@ -24,6 +24,7 @@ bitflags! {
     pub struct InterfaceFlags: u8 {
         const LOOPBACK = 0x01;
         const OPERATIVE = 0x02;
+        const BROADCAST = 0x04;
     }
 }