Files
tailscale/net/netmon/netmon_freebsd.go
T
Jonathan Nobels 3e89068792 net/netmon, wgengine/userspace: purge ChangeDelta.Major and address TODOs (#17823)
updates tailscale/corp#33891

Addresses several older the TODO's in netmon.  This removes the 
Major flag precomputes the ChangeDelta state, rather than making
consumers of ChangeDeltas sort that out themselves.   We're also seeing
a lot of ChangeDelta's being flagged as "Major" when they are
not interesting, triggering rebinds in wgengine that are not needed.  This
cleans that up and adds a host of additional tests.

The dependencies are cleaned, notably removing dependency on netmon
itself for calculating what is interesting, and what is not.  This includes letting
individual platforms set a bespoke global "IsInterestingInterface"
function.  This is only used on Darwin.

RebindRequired now roughly follows how "Major" was historically
calculated but includes some additional checks for various
uninteresting events such as changes in interface addresses that
shouldn't trigger a rebind.  This significantly reduces thrashing (by
roughly half on Darwin clients which switching between nics).   The individual
values that we roll  into RebindRequired are also exposed so that
components consuming netmap.ChangeDelta can ask more
targeted questions.

Signed-off-by: Jonathan Nobels <jonathan@tailscale.com>
2025-12-17 12:32:40 -05:00

56 lines
1.4 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package netmon
import (
"bufio"
"fmt"
"net"
"strings"
"tailscale.com/types/logger"
"tailscale.com/util/eventbus"
)
// unspecifiedMessage is a minimal message implementation that should not
// be ignored. In general, OS-specific implementations should use better
// types and avoid this if they can.
type unspecifiedMessage struct{}
func (unspecifiedMessage) ignore() bool { return false }
// devdConn implements osMon using devd(8).
type devdConn struct {
conn net.Conn
}
func newOSMon(_ *eventbus.Bus, logf logger.Logf, m *Monitor) (osMon, error) {
conn, err := net.Dial("unixpacket", "/var/run/devd.seqpacket.pipe")
if err != nil {
logf("devd dial error: %v, falling back to polling method", err)
return newPollingMon(logf, m)
}
return &devdConn{conn}, nil
}
func (c *devdConn) Close() error {
return c.conn.Close()
}
func (c *devdConn) Receive() (message, error) {
for {
msg, err := bufio.NewReader(c.conn).ReadString('\n')
if err != nil {
return nil, fmt.Errorf("reading devd socket: %v", err)
}
// Only return messages related to the network subsystem.
if !strings.Contains(msg, "system=IFNET") {
continue
}
// TODO: this is where the devd-specific message would
// get converted into a "standard" event message and returned.
return unspecifiedMessage{}, nil
}
}