Skip to content

fix(networkmonitor): false engine restarts #3355

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
wants to merge 1 commit into
base: main
Choose a base branch
from
Open

fix(networkmonitor): false engine restarts #3355

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
54 changes: 34 additions & 20 deletions client/internal/networkmonitor/check_change_bsd.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@ import (
"context"
"errors"
"fmt"
"net/netip"
"syscall"
"unsafe"

Expand Down Expand Up @@ -41,45 +42,58 @@ func checkChange(ctx context.Context, nexthopv4, nexthopv6 systemops.Nexthop) er
}
continue
}
if n < unix.SizeofRtMsghdr {
log.Debugf("Network monitor: read from routing socket returned less than expected: %d bytes", n)
isRouteMessage := n >= unix.SizeofRtMsghdr
// Route socket supports more than just route messages, skip non route messages
if !isRouteMessage {
continue
}

msg := (*unix.RtMsghdr)(unsafe.Pointer(&buf[0]))
isRouteChange := msg.Type == syscall.RTM_CHANGE || msg.Type == syscall.RTM_ADD || msg.Type == syscall.RTM_DELETE

switch msg.Type {
// handle route changes
case unix.RTM_ADD, syscall.RTM_DELETE:
if isRouteChange {
route, err := parseRouteMessage(buf[:n])
if err != nil {
log.Debugf("Network monitor: error parsing routing message: %v", err)
continue
}

if route.Dst.Bits() != 0 {
isDefaultRoute := route.Dst.Bits() == 0
if !isDefaultRoute {
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)
if hasDefaultRouteChanged(nexthopv4, nexthopv6) {
return nil
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)
return nil
}
}
}
}
}
}

func hasDefaultRouteChanged(nexthopv4, nexthopv6 systemops.Nexthop) bool {
// Compare current with saved netxhop
newNexthopv4, errv4 := systemops.GetNextHop(netip.IPv4Unspecified())
newNexthopv6, errv6 := systemops.GetNextHop(netip.IPv6Unspecified())
if errv4 != nil || errv6 != nil {
err := errors.Join(errv4, errv6)
log.Infof("Network monitor: failed to check next hop, assuming no network connection available: %s", err)
return true
}

hasValidV4Ifaces := nexthopv4.Intf != nil && newNexthopv4.Intf != nil
hasValidV6Ifaces := nexthopv6.Intf != nil && newNexthopv6.Intf != nil
hasV4GatewayChanged := nexthopv4.IP.Compare(newNexthopv4.IP) != 0
hasV6GatewayChanged := nexthopv6.IP.Compare(newNexthopv6.IP) != 0
hasV4IntfChanged := (nexthopv4.Intf != nil && newNexthopv4.Intf == nil) || (nexthopv4.Intf == nil && newNexthopv4.Intf != nil) || (hasValidV4Ifaces && nexthopv4.Intf.Name != newNexthopv4.Intf.Name)
hasV6IntfChanged := (nexthopv6.Intf != nil && newNexthopv6.Intf == nil) || (nexthopv6.Intf == nil && newNexthopv6.Intf != nil) || (hasValidV6Ifaces && nexthopv6.Intf.Name != newNexthopv6.Intf.Name)

if hasV4GatewayChanged || hasV6GatewayChanged || hasV4IntfChanged || hasV6IntfChanged {
log.Infof("Network monitor: default route changed v4 stats, GatewayChanged: %t Gateway: %#v, IntfChanged: %t, Intf: new - %s vs old - %s", hasV4GatewayChanged, newNexthopv4.IP.String(), hasV4IntfChanged, newNexthopv4.Intf.Name, nexthopv4.Intf.Name)
log.Infof("Network monitor: default route changed v6 stats, GatewayChanged: %t Gateway: %#v, IntfChanged: %t, Intf: new - %s vs old - %s", hasV6GatewayChanged, newNexthopv6.IP.String(), hasV6IntfChanged, newNexthopv6.Intf.Name, nexthopv6.Intf.Name)
return true
}
return false
}

func parseRouteMessage(buf []byte) (*systemops.Route, error) {
msgs, err := route.ParseRIB(route.RIBTypeRoute, buf)
if err != nil {
Expand Down
Loading