mirror of
https://github.com/octoleo/syncthing.git
synced 2024-11-19 19:45:12 +00:00
71 lines
2.2 KiB
Go
71 lines
2.2 KiB
Go
// Copyright 2012 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package ipv4
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"sync"
|
|
)
|
|
|
|
type rawOpt struct {
|
|
sync.RWMutex
|
|
cflags ControlFlags
|
|
}
|
|
|
|
func (c *rawOpt) set(f ControlFlags) { c.cflags |= f }
|
|
func (c *rawOpt) clear(f ControlFlags) { c.cflags &^= f }
|
|
func (c *rawOpt) isset(f ControlFlags) bool { return c.cflags&f != 0 }
|
|
|
|
type ControlFlags uint
|
|
|
|
const (
|
|
FlagTTL ControlFlags = 1 << iota // pass the TTL on the received packet
|
|
FlagSrc // pass the source address on the received packet
|
|
FlagDst // pass the destination address on the received packet
|
|
FlagInterface // pass the interface index on the received packet
|
|
)
|
|
|
|
// A ControlMessage represents per packet basis IP-level socket options.
|
|
type ControlMessage struct {
|
|
// Receiving socket options: SetControlMessage allows to
|
|
// receive the options from the protocol stack using ReadFrom
|
|
// method of PacketConn or RawConn.
|
|
//
|
|
// Specifying socket options: ControlMessage for WriteTo
|
|
// method of PacketConn or RawConn allows to send the options
|
|
// to the protocol stack.
|
|
//
|
|
TTL int // time-to-live, receiving only
|
|
Src net.IP // source address, specifying only
|
|
Dst net.IP // destination address, receiving only
|
|
IfIndex int // interface index, must be 1 <= value when specifying
|
|
}
|
|
|
|
func (cm *ControlMessage) String() string {
|
|
if cm == nil {
|
|
return "<nil>"
|
|
}
|
|
return fmt.Sprintf("ttl=%d src=%v dst=%v ifindex=%d", cm.TTL, cm.Src, cm.Dst, cm.IfIndex)
|
|
}
|
|
|
|
// Ancillary data socket options
|
|
const (
|
|
ctlTTL = iota // header field
|
|
ctlSrc // header field
|
|
ctlDst // header field
|
|
ctlInterface // inbound or outbound interface
|
|
ctlPacketInfo // inbound or outbound packet path
|
|
ctlMax
|
|
)
|
|
|
|
// A ctlOpt represents a binding for ancillary data socket option.
|
|
type ctlOpt struct {
|
|
name int // option name, must be equal or greater than 1
|
|
length int // option length
|
|
marshal func([]byte, *ControlMessage) []byte
|
|
parse func(*ControlMessage, []byte)
|
|
}
|