diff --git a/unum/vendor/golang.org/x/net/icmp/paramprob.go b/unum/vendor/golang.org/x/net/icmp/paramprob.go
new file mode 100644
index 0000000..0a2548d
--- /dev/null
+++ b/unum/vendor/golang.org/x/net/icmp/paramprob.go
@@ -0,0 +1,63 @@
+// Copyright 2014 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 icmp
+
+import (
+	"encoding/binary"
+	"golang.org/x/net/internal/iana"
+)
+
+// A ParamProb represents an ICMP parameter problem message body.
+type ParamProb struct {
+	Pointer    uintptr     // offset within the data where the error was detected
+	Data       []byte      // data, known as original datagram field
+	Extensions []Extension // extensions
+}
+
+// Len implements the Len method of MessageBody interface.
+func (p *ParamProb) Len(proto int) int {
+	if p == nil {
+		return 0
+	}
+	l, _ := multipartMessageBodyDataLen(proto, p.Data, p.Extensions)
+	return 4 + l
+}
+
+// Marshal implements the Marshal method of MessageBody interface.
+func (p *ParamProb) Marshal(proto int) ([]byte, error) {
+	if proto == iana.ProtocolIPv6ICMP {
+		b := make([]byte, p.Len(proto))
+		binary.BigEndian.PutUint32(b[:4], uint32(p.Pointer))
+		copy(b[4:], p.Data)
+		return b, nil
+	}
+	b, err := marshalMultipartMessageBody(proto, p.Data, p.Extensions)
+	if err != nil {
+		return nil, err
+	}
+	b[0] = byte(p.Pointer)
+	return b, nil
+}
+
+// parseParamProb parses b as an ICMP parameter problem message body.
+func parseParamProb(proto int, b []byte) (MessageBody, error) {
+	if len(b) < 4 {
+		return nil, errMessageTooShort
+	}
+	p := &ParamProb{}
+	if proto == iana.ProtocolIPv6ICMP {
+		p.Pointer = uintptr(binary.BigEndian.Uint32(b[:4]))
+		p.Data = make([]byte, len(b)-4)
+		copy(p.Data, b[4:])
+		return p, nil
+	}
+	p.Pointer = uintptr(b[0])
+	var err error
+	p.Data, p.Extensions, err = parseMultipartMessageBody(proto, b)
+	if err != nil {
+		return nil, err
+	}
+	return p, nil
+}