netbird/client/internal/networkmonitor/monitor_bsd.go
Viktor Liu ab82302c95
[client] Remove usage of custom dialer for localhost (#2639)
* Downgrade error log level for network monitor warnings

* Do not use custom dialer for localhost
2024-09-24 12:29:15 +02:00

108 lines
2.7 KiB
Go

//go:build (darwin && !ios) || dragonfly || freebsd || netbsd || openbsd
package networkmonitor
import (
"context"
"errors"
"fmt"
"syscall"
"unsafe"
log "github.com/sirupsen/logrus"
"golang.org/x/net/route"
"golang.org/x/sys/unix"
"github.com/netbirdio/netbird/client/internal/routemanager/systemops"
)
func checkChange(ctx context.Context, nexthopv4, nexthopv6 systemops.Nexthop, callback func()) error {
fd, err := unix.Socket(syscall.AF_ROUTE, syscall.SOCK_RAW, syscall.AF_UNSPEC)
if err != nil {
return fmt.Errorf("failed to open routing socket: %v", err)
}
defer func() {
err := unix.Close(fd)
if err != nil && !errors.Is(err, unix.EBADF) {
log.Warnf("Network monitor: failed to close routing socket: %v", err)
}
}()
go func() {
<-ctx.Done()
err := unix.Close(fd)
if err != nil && !errors.Is(err, unix.EBADF) {
log.Debugf("Network monitor: closed routing socket: %v", err)
}
}()
for {
select {
case <-ctx.Done():
return ErrStopped
default:
buf := make([]byte, 2048)
n, err := unix.Read(fd, buf)
if err != nil {
if !errors.Is(err, unix.EBADF) && !errors.Is(err, unix.EINVAL) {
log.Warnf("Network monitor: failed to read from routing socket: %v", err)
}
continue
}
if n < unix.SizeofRtMsghdr {
log.Debugf("Network monitor: read from routing socket returned less than expected: %d bytes", n)
continue
}
msg := (*unix.RtMsghdr)(unsafe.Pointer(&buf[0]))
switch msg.Type {
// handle route changes
case unix.RTM_ADD, syscall.RTM_DELETE:
route, err := parseRouteMessage(buf[:n])
if err != nil {
log.Debugf("Network monitor: error parsing routing message: %v", err)
continue
}
if route.Dst.Bits() != 0 {
continue
}
intf := "<nil>"
if route.Interface != nil {
intf = route.Interface.Name
}
switch msg.Type {
case unix.RTM_ADD:
log.Infof("Network monitor: default route changed: via %s, interface %s", route.Gw, intf)
go callback()
case unix.RTM_DELETE:
if nexthopv4.Intf != nil && route.Gw.Compare(nexthopv4.IP) == 0 || nexthopv6.Intf != nil && route.Gw.Compare(nexthopv6.IP) == 0 {
log.Infof("Network monitor: default route removed: via %s, interface %s", route.Gw, intf)
go callback()
}
}
}
}
}
}
func parseRouteMessage(buf []byte) (*systemops.Route, error) {
msgs, err := route.ParseRIB(route.RIBTypeRoute, buf)
if err != nil {
return nil, fmt.Errorf("parse RIB: %v", err)
}
if len(msgs) != 1 {
return nil, fmt.Errorf("unexpected RIB message msgs: %v", msgs)
}
msg, ok := msgs[0].(*route.RouteMessage)
if !ok {
return nil, fmt.Errorf("unexpected RIB message type: %T", msgs[0])
}
return systemops.MsgToRoute(msg)
}