From e1e8d058a33f7566f9c565d04b0d8b56f9645c35 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Wed, 25 Apr 2018 09:28:54 +0200 Subject: add vendor --- vendor/golang.org/x/net/icmp/extension.go | 108 ++++++++++++++++++++++++++++++ 1 file changed, 108 insertions(+) create mode 100644 vendor/golang.org/x/net/icmp/extension.go (limited to 'vendor/golang.org/x/net/icmp/extension.go') diff --git a/vendor/golang.org/x/net/icmp/extension.go b/vendor/golang.org/x/net/icmp/extension.go new file mode 100644 index 0000000..2005068 --- /dev/null +++ b/vendor/golang.org/x/net/icmp/extension.go @@ -0,0 +1,108 @@ +// Copyright 2015 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/ipv4" + "golang.org/x/net/ipv6" +) + +// An Extension represents an ICMP extension. +type Extension interface { + // Len returns the length of ICMP extension. + // Proto must be either the ICMPv4 or ICMPv6 protocol number. + Len(proto int) int + + // Marshal returns the binary encoding of ICMP extension. + // Proto must be either the ICMPv4 or ICMPv6 protocol number. + Marshal(proto int) ([]byte, error) +} + +const extensionVersion = 2 + +func validExtensionHeader(b []byte) bool { + v := int(b[0]&0xf0) >> 4 + s := binary.BigEndian.Uint16(b[2:4]) + if s != 0 { + s = checksum(b) + } + if v != extensionVersion || s != 0 { + return false + } + return true +} + +// parseExtensions parses b as a list of ICMP extensions. +// The length attribute l must be the length attribute field in +// received icmp messages. +// +// It will return a list of ICMP extensions and an adjusted length +// attribute that represents the length of the padded original +// datagram field. Otherwise, it returns an error. +func parseExtensions(typ Type, b []byte, l int) ([]Extension, int, error) { + // Still a lot of non-RFC 4884 compliant implementations are + // out there. Set the length attribute l to 128 when it looks + // inappropriate for backwards compatibility. + // + // A minimal extension at least requires 8 octets; 4 octets + // for an extension header, and 4 octets for a single object + // header. + // + // See RFC 4884 for further information. + switch typ { + case ipv4.ICMPTypeExtendedEchoRequest, ipv6.ICMPTypeExtendedEchoRequest: + if len(b) < 8 || !validExtensionHeader(b) { + return nil, -1, errNoExtension + } + l = 0 + default: + if 128 > l || l+8 > len(b) { + l = 128 + } + if l+8 > len(b) { + return nil, -1, errNoExtension + } + if !validExtensionHeader(b[l:]) { + if l == 128 { + return nil, -1, errNoExtension + } + l = 128 + if !validExtensionHeader(b[l:]) { + return nil, -1, errNoExtension + } + } + } + var exts []Extension + for b = b[l+4:]; len(b) >= 4; { + ol := int(binary.BigEndian.Uint16(b[:2])) + if 4 > ol || ol > len(b) { + break + } + switch b[2] { + case classMPLSLabelStack: + ext, err := parseMPLSLabelStack(b[:ol]) + if err != nil { + return nil, -1, err + } + exts = append(exts, ext) + case classInterfaceInfo: + ext, err := parseInterfaceInfo(b[:ol]) + if err != nil { + return nil, -1, err + } + exts = append(exts, ext) + case classInterfaceIdent: + ext, err := parseInterfaceIdent(b[:ol]) + if err != nil { + return nil, -1, err + } + exts = append(exts, ext) + } + b = b[ol:] + } + return exts, l, nil +} -- cgit v1.2.3