diff options
Diffstat (limited to 'vendor/golang.org/x/net/ipv4/control.go')
-rw-r--r-- | vendor/golang.org/x/net/ipv4/control.go | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/vendor/golang.org/x/net/ipv4/control.go b/vendor/golang.org/x/net/ipv4/control.go index da4da2dd0..a2b02ca95 100644 --- a/vendor/golang.org/x/net/ipv4/control.go +++ b/vendor/golang.org/x/net/ipv4/control.go @@ -8,6 +8,9 @@ import ( "fmt" "net" "sync" + + "golang.org/x/net/internal/iana" + "golang.org/x/net/internal/socket" ) type rawOpt struct { @@ -51,6 +54,77 @@ func (cm *ControlMessage) String() string { 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 |