From: Matt Joiner <anacrolix@gmail.com>
Date: Mon, 14 Aug 2023 01:38:47 +0000 (+1000)
Subject: Remove unnecessary use of SO_REUSEPORT
X-Git-Tag: v1.52.5
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=5a335520955f5501239feb699fc38e62b7cf8698;p=btrtrc.git
Remove unnecessary use of SO_REUSEPORT
Fixes https://github.com/anacrolix/torrent/discussions/856.
---
diff --git a/client_test.go b/client_test.go
index 22281efd..d2a88e9e 100644
--- a/client_test.go
+++ b/client_test.go
@@ -897,7 +897,7 @@ func TestBadPeerIpPort(t *testing.T) {
// https://github.com/anacrolix/torrent/issues/837
func TestClientConfigSetHandlerNotIgnored(t *testing.T) {
- cfg := NewDefaultClientConfig()
+ cfg := TestingConfig(t)
cfg.Logger.SetHandlers(log.DiscardHandler)
c := qt.New(t)
cl, err := NewClient(cfg)
diff --git a/fs/go.mod b/fs/go.mod
index 67c01ef0..004cee72 100644
--- a/fs/go.mod
+++ b/fs/go.mod
@@ -5,7 +5,7 @@ go 1.20
require (
github.com/anacrolix/envpprof v1.2.1
github.com/anacrolix/fuse v0.2.0
- github.com/anacrolix/log v0.14.0
+ github.com/anacrolix/log v0.14.1
github.com/anacrolix/missinggo/v2 v2.7.2-0.20230527121029-a582b4f397b9
github.com/anacrolix/tagflag v1.3.0
github.com/anacrolix/torrent v1.47.1-0.20221102120345-c63f7e1bd720
diff --git a/fs/go.sum b/fs/go.sum
index 3f7daed3..b32d6e43 100644
--- a/fs/go.sum
+++ b/fs/go.sum
@@ -46,6 +46,8 @@ github.com/anacrolix/log v0.10.1-0.20220123034749-3920702c17f8/go.mod h1:GmnE2c0
github.com/anacrolix/log v0.13.1/go.mod h1:D4+CvN8SnruK6zIFS/xPoRJmtvtnxs+CSfDQ+BFxZ68=
github.com/anacrolix/log v0.14.0 h1:mYhTSemILe/Z8tIxbGdTIWWpPspI8W/fhZHpoFbDaL0=
github.com/anacrolix/log v0.14.0/go.mod h1:1OmJESOtxQGNMlUO5rcv96Vpp9mfMqXXbe2RdinFLdY=
+github.com/anacrolix/log v0.14.1 h1:j2FcIpYZ5FbANetUcm5JNu+zUBGADSp/VbjhUPrAY0k=
+github.com/anacrolix/log v0.14.1/go.mod h1:1OmJESOtxQGNMlUO5rcv96Vpp9mfMqXXbe2RdinFLdY=
github.com/anacrolix/lsan v0.0.0-20211126052245-807000409a62 h1:P04VG6Td13FHMgS5ZBcJX23NPC/fiC4cp9bXwYujdYM=
github.com/anacrolix/lsan v0.0.0-20211126052245-807000409a62/go.mod h1:66cFKPCO7Sl4vbFnAaSq7e4OXtdMhRSBagJGWgmpJbM=
github.com/anacrolix/missinggo v0.0.0-20180725070939-60ef2fbf63df/go.mod h1:kwGiTUTZ0+p4vAz3VbAI5a30t2YbvemcmspjKwrAz5s=
diff --git a/socket.go b/socket.go
index c1fb97fd..2d4ea863 100644
--- a/socket.go
+++ b/socket.go
@@ -37,10 +37,17 @@ func listen(n network, addr string, f firewallCallback, logger log.Logger) (sock
}
}
+// Dialing TCP from a local port limits us to a single outgoing TCP connection to each remote
+// client. Instead, this should be a last resort if we need to use holepunching, and only then to
+// connect to other clients that actually try to holepunch TCP.
+const dialTcpFromListenPort = false
+
var tcpListenConfig = net.ListenConfig{
Control: func(network, address string, c syscall.RawConn) (err error) {
controlErr := c.Control(func(fd uintptr) {
- err = setReusePortSockOpts(fd)
+ if dialTcpFromListenPort {
+ err = setReusePortSockOpts(fd)
+ }
})
if err != nil {
return
@@ -54,38 +61,49 @@ var tcpListenConfig = net.ListenConfig{
func listenTcp(network, address string) (s socket, err error) {
l, err := tcpListenConfig.Listen(context.Background(), network, address)
- return tcpSocket{
+ if err != nil {
+ return
+ }
+ netDialer := net.Dialer{
+ // We don't want fallback, as we explicitly manage the IPv4/IPv6 distinction ourselves,
+ // although it's probably not triggered as I think the network is already constrained to
+ // tcp4 or tcp6 at this point.
+ FallbackDelay: -1,
+ // BitTorrent connections manage their own keepalives.
+ KeepAlive: tcpListenConfig.KeepAlive,
+ Control: func(network, address string, c syscall.RawConn) (err error) {
+ controlErr := c.Control(func(fd uintptr) {
+ err = setSockNoLinger(fd)
+ if err != nil {
+ // Failing to disable linger is undesirable, but not fatal.
+ log.Levelf(log.Debug, "error setting linger socket option on tcp socket: %v", err)
+ err = nil
+ }
+ // This is no longer required I think, see
+ // https://github.com/anacrolix/torrent/discussions/856. I added this originally to
+ // allow dialling out from the client's listen port, but that doesn't really work. I
+ // think Linux older than ~2013 doesn't support SO_REUSEPORT.
+ if dialTcpFromListenPort {
+ err = setReusePortSockOpts(fd)
+ }
+ })
+ if err == nil {
+ err = controlErr
+ }
+ return
+ },
+ }
+ if dialTcpFromListenPort {
+ netDialer.LocalAddr = l.Addr()
+ }
+ s = tcpSocket{
Listener: l,
NetworkDialer: NetworkDialer{
Network: network,
- Dialer: &net.Dialer{
- // Dialling TCP from a local port limits us to a single outgoing TCP connection to
- // each remote client. Instead this should be a last resort if we need to use holepunching, and only then to connect to other clients that actually try to holepunch TCP.
- //LocalAddr: l.Addr(),
-
- // We don't want fallback, as we explicitly manage the IPv4/IPv6 distinction
- // ourselves, although it's probably not triggered as I think the network is already
- // constrained to tcp4 or tcp6 at this point.
- FallbackDelay: -1,
- // BitTorrent connections manage their own keep-alives.
- KeepAlive: tcpListenConfig.KeepAlive,
- Control: func(network, address string, c syscall.RawConn) (err error) {
- controlErr := c.Control(func(fd uintptr) {
- err = setSockNoLinger(fd)
- if err != nil {
- // Failing to disable linger is undesirable, but not fatal.
- log.Printf("error setting linger socket option on tcp socket: %v", err)
- }
- err = setReusePortSockOpts(fd)
- })
- if err == nil {
- err = controlErr
- }
- return
- },
- },
+ Dialer: &netDialer,
},
- }, err
+ }
+ return
}
type tcpSocket struct {