summaryrefslogtreecommitdiffstats
path: root/vendor/golang.org/x/net/ipv4/control.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/golang.org/x/net/ipv4/control.go')
-rw-r--r--vendor/golang.org/x/net/ipv4/control.go70
1 files changed, 70 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/ipv4/control.go b/vendor/golang.org/x/net/ipv4/control.go
new file mode 100644
index 000000000..8cadfd7f3
--- /dev/null
+++ b/vendor/golang.org/x/net/ipv4/control.go
@@ -0,0 +1,70 @@
+// 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)
+}