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Move StripLocalAddresses to a common util

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Trac: 19026
This commit is contained in:
Arlo Breault 2020-03-26 13:05:24 -04:00
parent 5fa7578655
commit 670e4ba438
4 changed files with 72 additions and 63 deletions
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17
client/lib/lib_test.go
View file

@ -358,21 +358,4 @@ func TestSnowflakeClient(t *testing.T) {
})
})
Convey("Strip", t, func() {
const offerStart = "v=0\r\no=- 4358805017720277108 2 IN IP4 8.8.8.8\r\ns=-\r\nt=0 0\r\na=group:BUNDLE data\r\na=msid-semantic: WMS\r\nm=application 56688 DTLS/SCTP 5000\r\nc=IN IP4 8.8.8.8\r\n"
const goodCandidate = "a=candidate:3769337065 1 udp 2122260223 8.8.8.8 56688 typ host generation 0 network-id 1 network-cost 50\r\n"
const offerEnd = "a=ice-ufrag:aMAZ\r\na=ice-pwd:jcHb08Jjgrazp2dzjdrvPPvV\r\na=ice-options:trickle\r\na=fingerprint:sha-256 C8:88:EE:B9:E7:02:2E:21:37:ED:7A:D1:EB:2B:A3:15:A2:3B:5B:1C:3D:D4:D5:1F:06:CF:52:40:03:F8:DD:66\r\na=setup:actpass\r\na=mid:data\r\na=sctpmap:5000 webrtc-datachannel 1024\r\n"
offer := offerStart + goodCandidate +
"a=candidate:3769337065 1 udp 2122260223 192.168.0.100 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsLocal IPv4
"a=candidate:3769337065 1 udp 2122260223 fdf8:f53b:82e4::53 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsLocal IPv6
"a=candidate:3769337065 1 udp 2122260223 0.0.0.0 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsUnspecified IPv4
"a=candidate:3769337065 1 udp 2122260223 :: 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsUnspecified IPv6
"a=candidate:3769337065 1 udp 2122260223 127.0.0.1 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsLoopback IPv4
"a=candidate:3769337065 1 udp 2122260223 ::1 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsLoopback IPv6
offerEnd
So(stripLocalAddresses(offer), ShouldEqual, offerStart+goodCandidate+offerEnd)
})
}

47
client/lib/rendezvous.go
View file

@ -14,12 +14,10 @@ import (
"io"
"io/ioutil"
"log"
"net"
"net/http"
"net/url"
"git.torproject.org/pluggable-transports/snowflake.git/common/util"
"github.com/pion/sdp/v2"
"github.com/pion/webrtc/v2"
)
@ -81,49 +79,6 @@ func limitedRead(r io.Reader, limit int64) ([]byte, error) {
return p, err
}
// Stolen from https://github.com/golang/go/pull/30278
func IsLocal(ip net.IP) bool {
if ip4 := ip.To4(); ip4 != nil {
// Local IPv4 addresses are defined in https://tools.ietf.org/html/rfc1918
return ip4[0] == 10 ||
(ip4[0] == 172 && ip4[1]&0xf0 == 16) ||
(ip4[0] == 192 && ip4[1] == 168)
}
// Local IPv6 addresses are defined in https://tools.ietf.org/html/rfc4193
return len(ip) == net.IPv6len && ip[0]&0xfe == 0xfc
}
// Removes local LAN address ICE candidates
func stripLocalAddresses(str string) string {
var desc sdp.SessionDescription
err := desc.Unmarshal([]byte(str))
if err != nil {
return str
}
for _, m := range desc.MediaDescriptions {
attrs := make([]sdp.Attribute, 0)
for _, a := range m.Attributes {
if a.IsICECandidate() {
ice, err := a.ToICECandidate()
if err == nil && ice.Typ == "host" {
ip := net.ParseIP(ice.Address)
if ip != nil && (IsLocal(ip) || ip.IsUnspecified() || ip.IsLoopback()) {
/* no append in this case */
continue
}
}
}
attrs = append(attrs, a)
}
m.Attributes = attrs
}
bts, err := desc.Marshal()
if err != nil {
return str
}
return string(bts)
}
// Roundtrip HTTP POST using WebRTC SessionDescriptions.
//
// Send an SDP offer to the broker, which assigns a proxy and responds
@ -138,7 +93,7 @@ func (bc *BrokerChannel) Negotiate(offer *webrtc.SessionDescription) (
if !bc.keepLocalAddresses {
offer = &webrtc.SessionDescription{
Type: offer.Type,
SDP: stripLocalAddresses(offer.SDP),
SDP: util.StripLocalAddresses(offer.SDP),
}
}
data := bytes.NewReader([]byte(util.SerializeSessionDescription(offer)))

45
common/util/util.go
View file

@ -3,7 +3,9 @@ package util
import (
"encoding/json"
"log"
"net"
"github.com/pion/sdp/v2"
"github.com/pion/webrtc/v2"
)
@ -56,3 +58,46 @@ func DeserializeSessionDescription(msg string) *webrtc.SessionDescription {
SDP: parsed["sdp"].(string),
}
}
// Stolen from https://github.com/golang/go/pull/30278
func IsLocal(ip net.IP) bool {
if ip4 := ip.To4(); ip4 != nil {
// Local IPv4 addresses are defined in https://tools.ietf.org/html/rfc1918
return ip4[0] == 10 ||
(ip4[0] == 172 && ip4[1]&0xf0 == 16) ||
(ip4[0] == 192 && ip4[1] == 168)
}
// Local IPv6 addresses are defined in https://tools.ietf.org/html/rfc4193
return len(ip) == net.IPv6len && ip[0]&0xfe == 0xfc
}
// Removes local LAN address ICE candidates
func StripLocalAddresses(str string) string {
var desc sdp.SessionDescription
err := desc.Unmarshal([]byte(str))
if err != nil {
return str
}
for _, m := range desc.MediaDescriptions {
attrs := make([]sdp.Attribute, 0)
for _, a := range m.Attributes {
if a.IsICECandidate() {
ice, err := a.ToICECandidate()
if err == nil && ice.Typ == "host" {
ip := net.ParseIP(ice.Address)
if ip != nil && (IsLocal(ip) || ip.IsUnspecified() || ip.IsLoopback()) {
/* no append in this case */
continue
}
}
}
attrs = append(attrs, a)
}
m.Attributes = attrs
}
bts, err := desc.Marshal()
if err != nil {
return str
}
return string(bts)
}

26
common/util/util_test.go Normal file
View file

@ -0,0 +1,26 @@
package util
import (
"testing"
. "github.com/smartystreets/goconvey/convey"
)
func TestUtil(t *testing.T) {
Convey("Strip", t, func() {
const offerStart = "v=0\r\no=- 4358805017720277108 2 IN IP4 8.8.8.8\r\ns=-\r\nt=0 0\r\na=group:BUNDLE data\r\na=msid-semantic: WMS\r\nm=application 56688 DTLS/SCTP 5000\r\nc=IN IP4 8.8.8.8\r\n"
const goodCandidate = "a=candidate:3769337065 1 udp 2122260223 8.8.8.8 56688 typ host generation 0 network-id 1 network-cost 50\r\n"
const offerEnd = "a=ice-ufrag:aMAZ\r\na=ice-pwd:jcHb08Jjgrazp2dzjdrvPPvV\r\na=ice-options:trickle\r\na=fingerprint:sha-256 C8:88:EE:B9:E7:02:2E:21:37:ED:7A:D1:EB:2B:A3:15:A2:3B:5B:1C:3D:D4:D5:1F:06:CF:52:40:03:F8:DD:66\r\na=setup:actpass\r\na=mid:data\r\na=sctpmap:5000 webrtc-datachannel 1024\r\n"
offer := offerStart + goodCandidate +
"a=candidate:3769337065 1 udp 2122260223 192.168.0.100 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsLocal IPv4
"a=candidate:3769337065 1 udp 2122260223 fdf8:f53b:82e4::53 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsLocal IPv6
"a=candidate:3769337065 1 udp 2122260223 0.0.0.0 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsUnspecified IPv4
"a=candidate:3769337065 1 udp 2122260223 :: 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsUnspecified IPv6
"a=candidate:3769337065 1 udp 2122260223 127.0.0.1 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsLoopback IPv4
"a=candidate:3769337065 1 udp 2122260223 ::1 56688 typ host generation 0 network-id 1 network-cost 50\r\n" + // IsLoopback IPv6
offerEnd
So(StripLocalAddresses(offer), ShouldEqual, offerStart+goodCandidate+offerEnd)
})
}