mirror of
https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake.git
synced 2025-10-13 20:11:19 -04:00
83c01565ef
This update required two main changes to how we use the library. First, we had to make sure we created the datachannel on the offering peer side before creating the offer. Second, we had to make sure we wait for the gathering of all candidates to complete since trickle-ice is enabled by default. See the release notes for more details: https://github.com/pion/webrtc/wiki/Release-WebRTC@v3.0.0.
98 lines
2.5 KiB
Go
98 lines
2.5 KiB
Go
package util
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import (
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"encoding/json"
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"errors"
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"net"
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"github.com/pion/sdp/v2"
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"github.com/pion/webrtc/v3"
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)
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func SerializeSessionDescription(desc *webrtc.SessionDescription) (string, error) {
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bytes, err := json.Marshal(*desc)
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if err != nil {
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return "", err
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}
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return string(bytes), nil
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}
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func DeserializeSessionDescription(msg string) (*webrtc.SessionDescription, error) {
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var parsed map[string]interface{}
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err := json.Unmarshal([]byte(msg), &parsed)
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if err != nil {
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return nil, err
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}
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if _, ok := parsed["type"]; !ok {
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return nil, errors.New("cannot deserialize SessionDescription without type field")
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}
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if _, ok := parsed["sdp"]; !ok {
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return nil, errors.New("cannot deserialize SessionDescription without sdp field")
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}
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var stype webrtc.SDPType
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switch parsed["type"].(string) {
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default:
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return nil, errors.New("Unknown SDP type")
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case "offer":
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stype = webrtc.SDPTypeOffer
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case "pranswer":
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stype = webrtc.SDPTypePranswer
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case "answer":
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stype = webrtc.SDPTypeAnswer
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case "rollback":
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stype = webrtc.SDPTypeRollback
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}
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return &webrtc.SessionDescription{
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Type: stype,
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SDP: parsed["sdp"].(string),
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}, nil
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}
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// Stolen from https://github.com/golang/go/pull/30278
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func IsLocal(ip net.IP) bool {
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if ip4 := ip.To4(); ip4 != nil {
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// Local IPv4 addresses are defined in https://tools.ietf.org/html/rfc1918
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return ip4[0] == 10 ||
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(ip4[0] == 172 && ip4[1]&0xf0 == 16) ||
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(ip4[0] == 192 && ip4[1] == 168) ||
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// Carrier-Grade NAT as per https://tools.ietf.org/htm/rfc6598
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(ip4[0] == 100 && ip4[1]&0xc0 == 64) ||
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// Dynamic Configuration as per https://tools.ietf.org/htm/rfc3927
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(ip4[0] == 169 && ip4[1] == 254)
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}
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// Local IPv6 addresses are defined in https://tools.ietf.org/html/rfc4193
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return len(ip) == net.IPv6len && ip[0]&0xfe == 0xfc
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}
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// Removes local LAN address ICE candidates
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func StripLocalAddresses(str string) string {
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var desc sdp.SessionDescription
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err := desc.Unmarshal([]byte(str))
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if err != nil {
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return str
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}
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for _, m := range desc.MediaDescriptions {
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attrs := make([]sdp.Attribute, 0)
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for _, a := range m.Attributes {
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if a.IsICECandidate() {
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ice, err := a.ToICECandidate()
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if err == nil && ice.Typ == "host" {
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ip := net.ParseIP(ice.Address)
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if ip != nil && (IsLocal(ip) || ip.IsUnspecified() || ip.IsLoopback()) {
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/* no append in this case */
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continue
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}
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}
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}
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attrs = append(attrs, a)
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}
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m.Attributes = attrs
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}
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bts, err := desc.Marshal()
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if err != nil {
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return str
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}
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return string(bts)
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}
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