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EDNS0 client subnet: drop draft option (#589) 

Noone should be using this option, it has been deprecated ever since
RFC 7178 came out: May 2016. Remove code that deals with that.
This commit is contained in:
Miek Gieben 2017-11-28 07:48:19 +00:00 committed by GitHub
parent 052efef004
commit 6da3249dfb
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GPG Key ID: 4AEE18F83AFDEB23
3 changed files with 14 additions and 27 deletions
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1
README.md
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@ -154,6 +154,7 @@ Example programs can be found in the `github.com/miekg/exdns` repository.
* 7828 - edns-tcp-keepalive EDNS0 Option
* 7553 - URI record
* 7858 - DNS over TLS: Initiation and Performance Considerations
* 7871 - EDNS0 Client Subnet
* 7873 - Domain Name System (DNS) Cookies (draft-ietf-dnsop-cookies)
* 8080 - EdDSA for DNSSEC

35
edns.go
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@ -13,19 +13,18 @@ import (
const (
EDNS0LLQ = 0x1 // long lived queries: http://tools.ietf.org/html/draft-sekar-dns-llq-01
EDNS0UL = 0x2 // update lease draft: http://files.dns-sd.org/draft-sekar-dns-ul.txt
EDNS0NSID = 0x3 // nsid (RFC5001)
EDNS0NSID = 0x3 // nsid (See RFC 5001)
EDNS0DAU = 0x5 // DNSSEC Algorithm Understood
EDNS0DHU = 0x6 // DS Hash Understood
EDNS0N3U = 0x7 // NSEC3 Hash Understood
EDNS0SUBNET = 0x8 // client-subnet (RFC6891)
EDNS0SUBNET = 0x8 // client-subnet (See RFC 7871)
EDNS0EXPIRE = 0x9 // EDNS0 expire
EDNS0COOKIE = 0xa // EDNS0 Cookie
EDNS0TCPKEEPALIVE = 0xb // EDNS0 tcp keep alive (RFC7828)
EDNS0PADDING = 0xc // EDNS0 padding (RFC7830)
EDNS0SUBNETDRAFT = 0x50fa // Don't use! Use EDNS0SUBNET
EDNS0LOCALSTART = 0xFDE9 // Beginning of range reserved for local/experimental use (RFC6891)
EDNS0LOCALEND = 0xFFFE // End of range reserved for local/experimental use (RFC6891)
_DO = 1 << 15 // dnssec ok
EDNS0TCPKEEPALIVE = 0xb // EDNS0 tcp keep alive (See RFC 7828)
EDNS0PADDING = 0xc // EDNS0 padding (See RFC 7830)
EDNS0LOCALSTART = 0xFDE9 // Beginning of range reserved for local/experimental use (See RFC 6891)
EDNS0LOCALEND = 0xFFFE // End of range reserved for local/experimental use (See RFC 6891)
_DO = 1 << 15 // DNSSEC OK
)
// OPT is the EDNS0 RR appended to messages to convey extra (meta) information.
@ -58,9 +57,6 @@ func (rr *OPT) String() string {
}
case *EDNS0_SUBNET:
s += "\n; SUBNET: " + o.String()
if o.(*EDNS0_SUBNET).DraftOption {
s += " (draft)"
}
case *EDNS0_COOKIE:
s += "\n; COOKIE: " + o.String()
case *EDNS0_UL:
@ -188,7 +184,7 @@ func (e *EDNS0_NSID) unpack(b []byte) error { e.Nsid = hex.EncodeToString(b); re
func (e *EDNS0_NSID) String() string { return string(e.Nsid) }
// EDNS0_SUBNET is the subnet option that is used to give the remote nameserver
// an idea of where the client lives. It can then give back a different
// an idea of where the client lives. See RFC 7871. It can then give back a different
// answer depending on the location or network topology.
// Basic use pattern for creating an subnet option:
//
@ -204,26 +200,19 @@ func (e *EDNS0_NSID) String() string { return string(e.Nsid) }
// // e.Address = net.ParseIP("2001:7b8:32a::2") // for IPV6
// o.Option = append(o.Option, e)
//
// Note: the spec (draft-ietf-dnsop-edns-client-subnet-00) has some insane logic
// for which netmask applies to the address. This code will parse all the
// available bits when unpacking (up to optlen). When packing it will apply
// SourceNetmask. If you need more advanced logic, patches welcome and good luck.
// This code will parse all the available bits when unpacking (up to optlen).
// When packing it will apply SourceNetmask. If you need more advanced logic,
// patches welcome and good luck.
type EDNS0_SUBNET struct {
Code uint16 // Always EDNS0SUBNET
Family uint16 // 1 for IP, 2 for IP6
SourceNetmask uint8
SourceScope uint8
Address net.IP
DraftOption bool // Set to true if using the old (0x50fa) option code
}
// Option implements the EDNS0 interface.
func (e *EDNS0_SUBNET) Option() uint16 {
if e.DraftOption {
return EDNS0SUBNETDRAFT
}
return EDNS0SUBNET
}
func (e *EDNS0_SUBNET) Option() uint16 { return EDNS0SUBNET }
func (e *EDNS0_SUBNET) pack() ([]byte, error) {
b := make([]byte, 4)

5
msg_helpers.go
View File

@ -406,16 +406,13 @@ Option:
}
edns = append(edns, e)
off += int(optlen)
case EDNS0SUBNET, EDNS0SUBNETDRAFT:
case EDNS0SUBNET:
e := new(EDNS0_SUBNET)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {
return nil, len(msg), err
}
edns = append(edns, e)
off += int(optlen)
if code == EDNS0SUBNETDRAFT {
e.DraftOption = true
}
case EDNS0COOKIE:
e := new(EDNS0_COOKIE)
if err := e.unpack(msg[off : off+int(optlen)]); err != nil {