Files
ctrld/internal/clientinfo/ndp_linux.go
Cuong Manh Le fc527dbdfb all: eliminate usage of global ProxyLogger
So setting up logging for ctrld binary and ctrld packages could be done
more easily, decouple the required setup for interactive vs daemon
running.

This is the first step toward replacing rs/zerolog libary with a
different logging library.
2025-10-09 17:45:59 +07:00

63 lines
1.4 KiB
Go

package clientinfo
import (
"context"
"github.com/vishvananda/netlink"
"golang.org/x/sys/unix"
)
// scan populates NDP table using information from system mappings.
func (nd *ndpDiscover) scan() {
neighs, err := netlink.NeighList(0, netlink.FAMILY_V6)
if err != nil {
nd.logger.Warn().Err(err).Msg("could not get neigh list")
return
}
for _, n := range neighs {
// Skipping non-reachable neighbors.
if n.State&netlink.NUD_REACHABLE == 0 {
continue
}
ip := n.IP.String()
mac := n.HardwareAddr.String()
nd.saveInfo(ip, mac)
}
}
// subscribe watches NDP table changes and update new information to local table.
func (nd *ndpDiscover) subscribe(ctx context.Context) {
ch := make(chan netlink.NeighUpdate)
done := make(chan struct{})
defer close(done)
if err := netlink.NeighSubscribe(ch, done); err != nil {
nd.logger.Err(err).Msg("could not perform neighbor subscribing")
return
}
for {
select {
case <-ctx.Done():
return
case nu := <-ch:
if nu.Family != netlink.FAMILY_V6 {
continue
}
ip := normalizeIP(nu.IP.String())
if nu.Type == unix.RTM_DELNEIGH {
nd.logger.Debug().Msgf("removing NDP neighbor: %s", ip)
nd.mac.Delete(ip)
continue
}
mac := nu.HardwareAddr.String()
switch nu.State {
case netlink.NUD_REACHABLE:
nd.saveInfo(ip, mac)
case netlink.NUD_FAILED:
nd.logger.Debug().Msgf("removing NDP neighbor with failed state: %s", ip)
nd.mac.Delete(ip)
}
}
}
}