mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-01 15:00:00 +00:00
cf5c6d724d
* add miekg/dns dependency * set/validate accountDomain
145 lines
4.2 KiB
Go
145 lines
4.2 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"
|
|
|
|
"golang.org/x/net/internal/iana"
|
|
"golang.org/x/net/internal/socket"
|
|
)
|
|
|
|
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)
|
|
}
|
|
|
|
// Marshal returns the binary encoding of cm.
|
|
func (cm *ControlMessage) Marshal() []byte {
|
|
if cm == nil {
|
|
return nil
|
|
}
|
|
var m socket.ControlMessage
|
|
if ctlOpts[ctlPacketInfo].name > 0 && (cm.Src.To4() != nil || cm.IfIndex > 0) {
|
|
m = socket.NewControlMessage([]int{ctlOpts[ctlPacketInfo].length})
|
|
}
|
|
if len(m) > 0 {
|
|
ctlOpts[ctlPacketInfo].marshal(m, cm)
|
|
}
|
|
return m
|
|
}
|
|
|
|
// Parse parses b as a control message and stores the result in cm.
|
|
func (cm *ControlMessage) Parse(b []byte) error {
|
|
ms, err := socket.ControlMessage(b).Parse()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
for _, m := range ms {
|
|
lvl, typ, l, err := m.ParseHeader()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if lvl != iana.ProtocolIP {
|
|
continue
|
|
}
|
|
switch {
|
|
case typ == ctlOpts[ctlTTL].name && l >= ctlOpts[ctlTTL].length:
|
|
ctlOpts[ctlTTL].parse(cm, m.Data(l))
|
|
case typ == ctlOpts[ctlDst].name && l >= ctlOpts[ctlDst].length:
|
|
ctlOpts[ctlDst].parse(cm, m.Data(l))
|
|
case typ == ctlOpts[ctlInterface].name && l >= ctlOpts[ctlInterface].length:
|
|
ctlOpts[ctlInterface].parse(cm, m.Data(l))
|
|
case typ == ctlOpts[ctlPacketInfo].name && l >= ctlOpts[ctlPacketInfo].length:
|
|
ctlOpts[ctlPacketInfo].parse(cm, m.Data(l))
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// NewControlMessage returns a new control message.
|
|
//
|
|
// The returned message is large enough for options specified by cf.
|
|
func NewControlMessage(cf ControlFlags) []byte {
|
|
opt := rawOpt{cflags: cf}
|
|
var l int
|
|
if opt.isset(FlagTTL) && ctlOpts[ctlTTL].name > 0 {
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlTTL].length)
|
|
}
|
|
if ctlOpts[ctlPacketInfo].name > 0 {
|
|
if opt.isset(FlagSrc | FlagDst | FlagInterface) {
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlPacketInfo].length)
|
|
}
|
|
} else {
|
|
if opt.isset(FlagDst) && ctlOpts[ctlDst].name > 0 {
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlDst].length)
|
|
}
|
|
if opt.isset(FlagInterface) && ctlOpts[ctlInterface].name > 0 {
|
|
l += socket.ControlMessageSpace(ctlOpts[ctlInterface].length)
|
|
}
|
|
}
|
|
var b []byte
|
|
if l > 0 {
|
|
b = make([]byte, l)
|
|
}
|
|
return b
|
|
}
|
|
|
|
// 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)
|
|
}
|