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author | Christopher Speller <crspeller@gmail.com> | 2016-10-03 16:03:15 -0400 |
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committer | GitHub <noreply@github.com> | 2016-10-03 16:03:15 -0400 |
commit | 8f91c777559748fa6e857d9fc1f4ae079a532813 (patch) | |
tree | 190f7cef373764a0d47a91045fdb486ee3d6781d /vendor/golang.org/x/net/icmp/extension.go | |
parent | 5f8e5c401bd96cba9a98b2db02d72f9cbacb0103 (diff) | |
download | chat-8f91c777559748fa6e857d9fc1f4ae079a532813.tar.gz chat-8f91c777559748fa6e857d9fc1f4ae079a532813.tar.bz2 chat-8f91c777559748fa6e857d9fc1f4ae079a532813.zip |
Adding ability to serve TLS directly from Mattermost server (#4119)
Diffstat (limited to 'vendor/golang.org/x/net/icmp/extension.go')
-rw-r--r-- | vendor/golang.org/x/net/icmp/extension.go | 89 |
1 files changed, 89 insertions, 0 deletions
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 000000000..402a7514b --- /dev/null +++ b/vendor/golang.org/x/net/icmp/extension.go @@ -0,0 +1,89 @@ +// 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" + +// 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(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. + 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) + } + b = b[ol:] + } + return exts, l, nil +} |