| // 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. |
| |
| // +build aix darwin dragonfly freebsd linux netbsd openbsd solaris |
| |
| package ipv4 |
| |
| import ( |
| "unsafe" |
| |
| "golang.org/x/net/internal/iana" |
| "golang.org/x/net/internal/socket" |
| ) |
| |
| func setControlMessage(c *socket.Conn, opt *rawOpt, cf ControlFlags, on bool) error { |
| opt.Lock() |
| defer opt.Unlock() |
| if so, ok := sockOpts[ssoReceiveTTL]; ok && cf&FlagTTL != 0 { |
| if err := so.SetInt(c, boolint(on)); err != nil { |
| return err |
| } |
| if on { |
| opt.set(FlagTTL) |
| } else { |
| opt.clear(FlagTTL) |
| } |
| } |
| if so, ok := sockOpts[ssoPacketInfo]; ok { |
| if cf&(FlagSrc|FlagDst|FlagInterface) != 0 { |
| if err := so.SetInt(c, boolint(on)); err != nil { |
| return err |
| } |
| if on { |
| opt.set(cf & (FlagSrc | FlagDst | FlagInterface)) |
| } else { |
| opt.clear(cf & (FlagSrc | FlagDst | FlagInterface)) |
| } |
| } |
| } else { |
| if so, ok := sockOpts[ssoReceiveDst]; ok && cf&FlagDst != 0 { |
| if err := so.SetInt(c, boolint(on)); err != nil { |
| return err |
| } |
| if on { |
| opt.set(FlagDst) |
| } else { |
| opt.clear(FlagDst) |
| } |
| } |
| if so, ok := sockOpts[ssoReceiveInterface]; ok && cf&FlagInterface != 0 { |
| if err := so.SetInt(c, boolint(on)); err != nil { |
| return err |
| } |
| if on { |
| opt.set(FlagInterface) |
| } else { |
| opt.clear(FlagInterface) |
| } |
| } |
| } |
| return nil |
| } |
| |
| func marshalTTL(b []byte, cm *ControlMessage) []byte { |
| m := socket.ControlMessage(b) |
| m.MarshalHeader(iana.ProtocolIP, sysIP_RECVTTL, 1) |
| return m.Next(1) |
| } |
| |
| func parseTTL(cm *ControlMessage, b []byte) { |
| cm.TTL = int(*(*byte)(unsafe.Pointer(&b[:1][0]))) |
| } |