From 3a3169551bf6b579fd8e5044479abf6bbfc3bbea Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 30 Jul 2023 16:31:30 -0400
Subject: [PATCH] detect kernel GSO support
---
send_conn.go | 4 +++-
send_conn_test.go | 6 +++---
sys_conn_helper_darwin.go | 3 +++
sys_conn_helper_freebsd.go | 3 +++
sys_conn_helper_linux.go | 12 ++++++++++++
sys_conn_helper_nonlinux.go | 4 ++--
sys_conn_oob.go | 5 ++++-
7 files changed, 30 insertions(+), 7 deletions(-)
diff --git a/send_conn.go b/send_conn.go
index 34cbfd6e..d8ddbc87 100644
--- a/send_conn.go
+++ b/send_conn.go
@@ -97,7 +97,9 @@ func (c *sconn) Write(p []byte, size protocol.ByteCount) error {
func (c *sconn) capabilities() connCapabilities {
capabilities := c.rawConn.capabilities()
- capabilities.GSO = !c.gotGSOError
+ if capabilities.GSO {
+ capabilities.GSO = !c.gotGSOError
+ }
return capabilities
}
diff --git a/send_conn_test.go b/send_conn_test.go
index 8676d409..024a8eba 100644
--- a/send_conn_test.go
+++ b/send_conn_test.go
@@ -60,8 +60,8 @@ var _ = Describe("Connection (for sending packets)", func() {
Expect(oob).To(Equal(msg))
return 0, errGSO
}),
- rawConn.EXPECT().WritePacket([]byte("foo"), remoteAddr, []byte{}).Return(3, nil),
- rawConn.EXPECT().WritePacket([]byte("bar"), remoteAddr, []byte{}).Return(3, nil),
+ rawConn.EXPECT().WritePacket([]byte("foo"), remoteAddr, gomock.Len(0)).Return(3, nil),
+ rawConn.EXPECT().WritePacket([]byte("bar"), remoteAddr, gomock.Len(0)).Return(3, nil),
)
Expect(c.Write([]byte("foobar"), 3)).To(Succeed())
Expect(c.capabilities().GSO).To(BeFalse()) // GSO support is now disabled
@@ -75,7 +75,7 @@ var _ = Describe("Connection (for sending packets)", func() {
rawConn.EXPECT().LocalAddr()
rawConn.EXPECT().capabilities()
c := newSendConn(rawConn, remoteAddr, packetInfo{}, utils.DefaultLogger)
- rawConn.EXPECT().WritePacket([]byte("foobar"), remoteAddr, nil)
+ rawConn.EXPECT().WritePacket([]byte("foobar"), remoteAddr, gomock.Len(0))
Expect(c.Write([]byte("foobar"), 6)).To(Succeed())
})
}
diff --git a/sys_conn_helper_darwin.go b/sys_conn_helper_darwin.go
index bf735f0f..758cf778 100644
--- a/sys_conn_helper_darwin.go
+++ b/sys_conn_helper_darwin.go
@@ -5,6 +5,7 @@ package quic
import (
"encoding/binary"
"net/netip"
+ "syscall"
"golang.org/x/sys/unix"
)
@@ -29,3 +30,5 @@ func parseIPv4PktInfo(body []byte) (ip netip.Addr, ifIndex uint32, ok bool) {
}
return netip.AddrFrom4(*(*[4]byte)(body[8:12])), binary.LittleEndian.Uint32(body), true
}
+
+func isGSOSupported(syscall.RawConn) bool { return false }
diff --git a/sys_conn_helper_freebsd.go b/sys_conn_helper_freebsd.go
index fe5a7c20..a2baae3b 100644
--- a/sys_conn_helper_freebsd.go
+++ b/sys_conn_helper_freebsd.go
@@ -4,6 +4,7 @@ package quic
import (
"net/netip"
+ "syscall"
"golang.org/x/sys/unix"
)
@@ -24,3 +25,5 @@ func parseIPv4PktInfo(body []byte) (ip netip.Addr, _ uint32, ok bool) {
}
return netip.AddrFrom4(*(*[4]byte)(body)), 0, true
}
+
+func isGSOSupported(syscall.RawConn) bool { return false }
diff --git a/sys_conn_helper_linux.go b/sys_conn_helper_linux.go
index 4e87bba0..5a177c29 100644
--- a/sys_conn_helper_linux.go
+++ b/sys_conn_helper_linux.go
@@ -52,6 +52,18 @@ func parseIPv4PktInfo(body []byte) (ip netip.Addr, ifIndex uint32, ok bool) {
return netip.AddrFrom4(*(*[4]byte)(body[8:12])), binary.LittleEndian.Uint32(body), true
}
+// isGSOSupported tests if the kernel supports GSO.
+// Sending with GSO might still fail later on, if the interface doesn't support it (see isGSOError).
+func isGSOSupported(conn syscall.RawConn) bool {
+ var serr error
+ if err := conn.Control(func(fd uintptr) {
+ _, serr = unix.GetsockoptInt(int(fd), unix.IPPROTO_UDP, unix.UDP_SEGMENT)
+ }); err != nil {
+ return false
+ }
+ return serr == nil
+}
+
func appendUDPSegmentSizeMsg(b []byte, size uint16) []byte {
startLen := len(b)
const dataLen = 2 // payload is a uint16
diff --git a/sys_conn_helper_nonlinux.go b/sys_conn_helper_nonlinux.go
index 48ab10aa..cace82d5 100644
--- a/sys_conn_helper_nonlinux.go
+++ b/sys_conn_helper_nonlinux.go
@@ -5,5 +5,5 @@ package quic
func forceSetReceiveBuffer(c any, bytes int) error { return nil }
func forceSetSendBuffer(c any, bytes int) error { return nil }
-func appendUDPSegmentSizeMsg(_ []byte, _ uint16) []byte { return nil }
-func isGSOError(error) bool { return false }
+func appendUDPSegmentSizeMsg([]byte, uint16) []byte { return nil }
+func isGSOError(error) bool { return false }
diff --git a/sys_conn_oob.go b/sys_conn_oob.go
index aa69262b..4026a7b3 100644
--- a/sys_conn_oob.go
+++ b/sys_conn_oob.go
@@ -137,8 +137,11 @@ func newConn(c OOBCapablePacketConn, supportsDF bool) (*oobConn, error) {
batchConn: bc,
messages: msgs,
readPos: batchSize,
+ cap: connCapabilities{
+ DF: supportsDF,
+ GSO: isGSOSupported(rawConn),
+ },
}
- oobConn.cap.DF = supportsDF
for i := 0; i < batchSize; i++ {
oobConn.messages[i].OOB = make([]byte, oobBufferSize)
}