uquic/send_conn.go
2025-04-01 11:48:45 -06:00

127 lines
3.1 KiB
Go

package quic
import (
"net"
"sync/atomic"
"github.com/refraction-networking/uquic/internal/protocol"
"github.com/refraction-networking/uquic/internal/utils"
)
// A sendConn allows sending using a simple Write() on a non-connected packet conn.
type sendConn interface {
Write(b []byte, gsoSize uint16, ecn protocol.ECN) error
WriteTo([]byte, net.Addr) error
Close() error
LocalAddr() net.Addr
RemoteAddr() net.Addr
ChangeRemoteAddr(addr net.Addr, info packetInfo)
capabilities() connCapabilities
}
type remoteAddrInfo struct {
addr net.Addr
oob []byte
}
type sconn struct {
rawConn
localAddr net.Addr
remoteAddrInfo atomic.Pointer[remoteAddrInfo]
logger utils.Logger
// If GSO enabled, and we receive a GSO error for this remote address, GSO is disabled.
gotGSOError bool
// Used to catch the error sometimes returned by the first sendmsg call on Linux,
// see https://github.com/golang/go/issues/63322.
wroteFirstPacket bool
}
var _ sendConn = &sconn{}
func newSendConn(c rawConn, remote net.Addr, info packetInfo, logger utils.Logger) *sconn {
localAddr := c.LocalAddr()
if info.addr.IsValid() {
if udpAddr, ok := localAddr.(*net.UDPAddr); ok {
addrCopy := *udpAddr
addrCopy.IP = info.addr.AsSlice()
localAddr = &addrCopy
}
}
oob := info.OOB()
// increase oob slice capacity, so we can add the UDP_SEGMENT and ECN control messages without allocating
l := len(oob)
oob = append(oob, make([]byte, 64)...)[:l]
sc := &sconn{
rawConn: c,
localAddr: localAddr,
logger: logger,
}
sc.remoteAddrInfo.Store(&remoteAddrInfo{
addr: remote,
oob: oob,
})
return sc
}
func (c *sconn) Write(p []byte, gsoSize uint16, ecn protocol.ECN) error {
ai := c.remoteAddrInfo.Load()
err := c.writePacket(p, ai.addr, ai.oob, gsoSize, ecn)
if err != nil && isGSOError(err) {
// disable GSO for future calls
c.gotGSOError = true
if c.logger.Debug() {
c.logger.Debugf("GSO failed when sending to %s", ai.addr)
}
// send out the packets one by one
for len(p) > 0 {
l := len(p)
if l > int(gsoSize) {
l = int(gsoSize)
}
if err := c.writePacket(p[:l], ai.addr, ai.oob, 0, ecn); err != nil {
return err
}
p = p[l:]
}
return nil
}
return err
}
func (c *sconn) writePacket(p []byte, addr net.Addr, oob []byte, gsoSize uint16, ecn protocol.ECN) error {
_, err := c.WritePacket(p, addr, oob, gsoSize, ecn)
if err != nil && !c.wroteFirstPacket && isPermissionError(err) {
_, err = c.WritePacket(p, addr, oob, gsoSize, ecn)
}
c.wroteFirstPacket = true
return err
}
func (c *sconn) WriteTo(b []byte, addr net.Addr) error {
_, err := c.WritePacket(b, addr, nil, 0, protocol.ECNUnsupported)
return err
}
func (c *sconn) capabilities() connCapabilities {
capabilities := c.rawConn.capabilities()
if capabilities.GSO {
capabilities.GSO = !c.gotGSOError
}
return capabilities
}
func (c *sconn) ChangeRemoteAddr(addr net.Addr, info packetInfo) {
c.remoteAddrInfo.Store(&remoteAddrInfo{
addr: addr,
oob: info.OOB(),
})
}
func (c *sconn) RemoteAddr() net.Addr { return c.remoteAddrInfo.Load().addr }
func (c *sconn) LocalAddr() net.Addr { return c.localAddr }