wgengine/magicsock: always run ReceiveIPv6

One of the consequences of the 	bind refactoring in 6f23087175
is that attempting to bind an IPv6 socket will always
result in c.pconn6.pconn being non-nil.
If the bind fails, it'll be set to a placeholder packet conn
that blocks forever.

As a result, we can always run ReceiveIPv6 and health check it.
This removes IPv4/IPv6 asymmetry and also will allow health checks
to detect any IPv6 receive func failures.

Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>
This commit is contained in:
Josh Bleecher Snyder 2021-04-28 10:43:51 -07:00
parent fe50ded95c
commit 9d542e08e2
2 changed files with 6 additions and 9 deletions

View File

@ -297,10 +297,10 @@ func overallErrorLocked() error {
var (
ReceiveIPv4 = ReceiveFuncStats{name: "ReceiveIPv4"}
// ReceiveIPv6 isn't guaranteed to be running, so skip it for now.
ReceiveIPv6 = ReceiveFuncStats{name: "ReceiveIPv6"}
ReceiveDERP = ReceiveFuncStats{name: "ReceiveDERP"}
receiveFuncs = []*ReceiveFuncStats{&ReceiveIPv4, &ReceiveDERP}
receiveFuncs = []*ReceiveFuncStats{&ReceiveIPv4, &ReceiveIPv6, &ReceiveDERP}
)
// ReceiveFuncStats tracks the calls made to a wireguard-go receive func.

View File

@ -1578,6 +1578,8 @@ func (c *Conn) noteRecvActivityFromEndpoint(e conn.Endpoint) {
// receiveIPv6 receives a UDP IPv6 packet. It is called by wireguard-go.
func (c *Conn) receiveIPv6(b []byte) (int, conn.Endpoint, error) {
health.ReceiveIPv6.Enter()
defer health.ReceiveIPv6.Exit()
for {
n, ipp, err := c.pconn6.ReadFromNetaddr(b)
if err != nil {
@ -2411,10 +2413,7 @@ func (c *connBind) Open(ignoredPort uint16) ([]conn.ReceiveFunc, uint16, error)
return nil, 0, errors.New("magicsock: connBind already open")
}
c.closed = false
fns := []conn.ReceiveFunc{c.receiveIPv4, c.receiveDERP}
if c.pconn6 != nil {
fns = append(fns, c.receiveIPv6)
}
fns := []conn.ReceiveFunc{c.receiveIPv4, c.receiveIPv6, c.receiveDERP}
// TODO: Combine receiveIPv4 and receiveIPv6 and receiveIP into a single
// closure that closes over a *RebindingUDPConn?
return fns, c.LocalPort(), nil
@ -2436,9 +2435,7 @@ func (c *connBind) Close() error {
c.closed = true
// Unblock all outstanding receives.
c.pconn4.Close()
if c.pconn6 != nil {
c.pconn6.Close()
}
// Send an empty read result to unblock receiveDERP,
// which will then check connBind.Closed.
c.derpRecvCh <- derpReadResult{}