mirror of
https://github.com/netbirdio/netbird.git
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82 lines
2.2 KiB
Go
82 lines
2.2 KiB
Go
//go:build !android
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package networkmonitor
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import (
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"context"
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"errors"
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"fmt"
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"net"
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"net/netip"
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"syscall"
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log "github.com/sirupsen/logrus"
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"github.com/vishvananda/netlink"
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)
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func checkChange(ctx context.Context, nexthopv4 netip.Addr, intfv4 *net.Interface, nexthop6 netip.Addr, intfv6 *net.Interface, callback func()) error {
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if intfv4 == nil && intfv6 == nil {
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return errors.New("no interfaces available")
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}
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linkChan := make(chan netlink.LinkUpdate)
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done := make(chan struct{})
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defer close(done)
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if err := netlink.LinkSubscribe(linkChan, done); err != nil {
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return fmt.Errorf("subscribe to link updates: %v", err)
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}
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routeChan := make(chan netlink.RouteUpdate)
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if err := netlink.RouteSubscribe(routeChan, done); err != nil {
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return fmt.Errorf("subscribe to route updates: %v", err)
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}
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log.Info("Network monitor: started")
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for {
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select {
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case <-ctx.Done():
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return ErrStopped
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// handle interface state changes
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case update := <-linkChan:
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if (intfv4 == nil || update.Index != int32(intfv4.Index)) && (intfv6 == nil || update.Index != int32(intfv6.Index)) {
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continue
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}
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switch update.Header.Type {
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case syscall.RTM_DELLINK:
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log.Infof("Network monitor: monitored interface (%s) is gone", update.Link.Attrs().Name)
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go callback()
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return nil
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case syscall.RTM_NEWLINK:
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if (update.IfInfomsg.Flags&syscall.IFF_RUNNING) == 0 && update.Link.Attrs().OperState == netlink.OperDown {
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log.Infof("Network monitor: monitored interface (%s) is down.", update.Link.Attrs().Name)
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go callback()
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return nil
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}
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}
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// handle route changes
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case route := <-routeChan:
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// default route and main table
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if route.Dst != nil || route.Table != syscall.RT_TABLE_MAIN {
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continue
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}
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switch route.Type {
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// triggered on added/replaced routes
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case syscall.RTM_NEWROUTE:
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log.Infof("Network monitor: default route changed: via %s, interface %d", route.Gw, route.LinkIndex)
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go callback()
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return nil
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case syscall.RTM_DELROUTE:
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if intfv4 != nil && route.Gw.Equal(nexthopv4.AsSlice()) || intfv6 != nil && route.Gw.Equal(nexthop6.AsSlice()) {
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log.Infof("Network monitor: default route removed: via %s, interface %d", route.Gw, route.LinkIndex)
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go callback()
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return nil
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}
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}
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}
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}
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}
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