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Merge pull request #134 from m13253/fix/parse-ecs-golang
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@m13253
m13253 authored Sep 14, 2022
2 parents 533ea58 + f1b3133 commit f212286
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Showing 2 changed files with 165 additions and 38 deletions.
84 changes: 46 additions & 38 deletions doh-server/google.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -90,45 +90,14 @@ func (s *Server) parseRequestGoogle(ctx context.Context, w http.ResponseWriter,
if ednsClientSubnet == "0/0" {
ednsClientSubnet = "0.0.0.0/0"
}
slash := strings.IndexByte(ednsClientSubnet, '/')
if slash < 0 {
ednsClientAddress = net.ParseIP(ednsClientSubnet)
if ednsClientAddress == nil {
return &DNSRequest{
errcode: 400,
errtext: fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet),
}
}
if ipv4 := ednsClientAddress.To4(); ipv4 != nil {
ednsClientFamily = 1
ednsClientAddress = ipv4
ednsClientNetmask = 24
} else {
ednsClientFamily = 2
ednsClientNetmask = 56
}
} else {
ednsClientAddress = net.ParseIP(ednsClientSubnet[:slash])
if ednsClientAddress == nil {
return &DNSRequest{
errcode: 400,
errtext: fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet),
}
}
if ipv4 := ednsClientAddress.To4(); ipv4 != nil {
ednsClientFamily = 1
ednsClientAddress = ipv4
} else {
ednsClientFamily = 2
}
netmask, err := strconv.ParseUint(ednsClientSubnet[slash+1:], 10, 8)
if err != nil {
return &DNSRequest{
errcode: 400,
errtext: fmt.Sprintf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet),
}

var err error
ednsClientFamily, ednsClientAddress, ednsClientNetmask, err = parseSubnet(ednsClientSubnet)
if err != nil {
return &DNSRequest{
errcode: 400,
errtext: err.Error(),
}
ednsClientNetmask = uint8(netmask)
}
} else {
ednsClientAddress = s.findClientIP(r)
Expand Down Expand Up @@ -169,6 +138,45 @@ func (s *Server) parseRequestGoogle(ctx context.Context, w http.ResponseWriter,
}
}

func parseSubnet(ednsClientSubnet string) (ednsClientFamily uint16, ednsClientAddress net.IP, ednsClientNetmask uint8, err error) {
slash := strings.IndexByte(ednsClientSubnet, '/')
if slash < 0 {
ednsClientAddress = net.ParseIP(ednsClientSubnet)
if ednsClientAddress == nil {
err = fmt.Errorf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet)
return
}
if ipv4 := ednsClientAddress.To4(); ipv4 != nil {
ednsClientFamily = 1
ednsClientAddress = ipv4
ednsClientNetmask = 24
} else {
ednsClientFamily = 2
ednsClientNetmask = 56
}
} else {
ednsClientAddress = net.ParseIP(ednsClientSubnet[:slash])
if ednsClientAddress == nil {
err = fmt.Errorf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet)
return
}
if ipv4 := ednsClientAddress.To4(); ipv4 != nil {
ednsClientFamily = 1
ednsClientAddress = ipv4
} else {
ednsClientFamily = 2
}
netmask, err1 := strconv.ParseUint(ednsClientSubnet[slash+1:], 10, 8)
if err1 != nil {
err = fmt.Errorf("Invalid argument value: \"edns_client_subnet\" = %q", ednsClientSubnet)
return
}
ednsClientNetmask = uint8(netmask)
}

return
}

func (s *Server) generateResponseGoogle(ctx context.Context, w http.ResponseWriter, r *http.Request, req *DNSRequest) {
respJSON := jsondns.Marshal(req.response)
respStr, err := json.Marshal(respJSON)
Expand Down
119 changes: 119 additions & 0 deletions doh-server/parse_test.go
View file
Original file line number Diff line number Diff line change
@@ -0,0 +1,119 @@
/*
DNS-over-HTTPS
Copyright (C) 2017-2018 Star Brilliant <m13253@hotmail.com>
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
DEALINGS IN THE SOFTWARE.
*/

package main

import (
"testing"

"github.com/miekg/dns"
)

func TestParseCIDR(t *testing.T) {
t.Parallel()
for _, ednsClientSubnet := range []string{
"2001:db8::/0",
"2001:db8::/56",
"2001:db8::/129",
"2001:db8::",

"127.0.0.1/0",
"127.0.0.1/24",
"127.0.0.1/33",
"127.0.0.1",

"::ffff:7f00:1/0",
"::ffff:7f00:1/120",
"::ffff:7f00:1",
"127.0.0.1/0",
"127.0.0.1/24",
"127.0.0.1",
} {
_, ip, ipNet, err := parseSubnet(ednsClientSubnet)
if err != nil {
t.Errorf("ecs:%s ip:[%v] ipNet:[%v] err:[%v]", ednsClientSubnet, ip, ipNet, err)
}
}
}

func TestParseInvalidCIDR(t *testing.T) {
t.Parallel()

for _, ip := range []string{
"test",
"test/0",
"test/24",
"test/34",
"test/56",
"test/129",
} {
_, _, _, err := parseSubnet(ip)
if err == nil {
t.Errorf("expected error for %q", ip)
}
}
}

func TestEdns0SubnetParseCIDR(t *testing.T) {
t.Parallel()
// init dns Msg
msg := new(dns.Msg)
msg.Id = dns.Id()
msg.SetQuestion(dns.Fqdn("example.com"), 1)

// init edns0Subnet
edns0Subnet := new(dns.EDNS0_SUBNET)
edns0Subnet.Code = dns.EDNS0SUBNET
edns0Subnet.SourceScope = 0

// init opt
opt := new(dns.OPT)
opt.Hdr.Name = "."
opt.Hdr.Rrtype = dns.TypeOPT
opt.SetUDPSize(dns.DefaultMsgSize)

opt.Option = append(opt.Option, edns0Subnet)
msg.Extra = append(msg.Extra, opt)

for _, subnet := range []string{"::ffff:7f00:1/120", "127.0.0.1/24"} {
var err error
edns0Subnet.Family, edns0Subnet.Address, edns0Subnet.SourceNetmask, err = parseSubnet(subnet)
if err != nil {
t.Error(err)
continue
}
t.Log(msg.Pack())
}

// ------127.0.0.1/24-----
// [143 29 1 0 0 1 0 0 0 0 0 1 7 101 120 97 109 112 108 101 3 99 111 109 0 0 1 0 1 0
// opt start 0 41 16 0 0 0 0 0 0 11
// subnet start 0 8 0 7 0 1 24 0
// client subnet start 127 0 0]

// -----::ffff:7f00:1/120----
// [111 113 1 0 0 1 0 0 0 0 0 1 7 101 120 97 109 112 108 101 3 99 111 109 0 0 1 0 1 0
// opt start 0 41 16 0 0 0 0 0 0 23
// subnet start 0 8 0 19 0 2 120 0
// client subnet start 0 0 0 0 0 0 0 0 0 0 255 255 127 0 0]
}

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