1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
|
package util
import (
"encoding/json"
"errors"
"net"
"github.com/pion/ice/v2"
"github.com/pion/sdp/v3"
"github.com/pion/webrtc/v3"
)
func SerializeSessionDescription(desc *webrtc.SessionDescription) (string, error) {
bytes, err := json.Marshal(*desc)
if err != nil {
return "", err
}
return string(bytes), nil
}
func DeserializeSessionDescription(msg string) (*webrtc.SessionDescription, error) {
var parsed map[string]interface{}
err := json.Unmarshal([]byte(msg), &parsed)
if err != nil {
return nil, err
}
if _, ok := parsed["type"]; !ok {
return nil, errors.New("cannot deserialize SessionDescription without type field")
}
if _, ok := parsed["sdp"]; !ok {
return nil, errors.New("cannot deserialize SessionDescription without sdp field")
}
var stype webrtc.SDPType
switch parsed["type"].(string) {
default:
return nil, errors.New("Unknown SDP type")
case "offer":
stype = webrtc.SDPTypeOffer
case "pranswer":
stype = webrtc.SDPTypePranswer
case "answer":
stype = webrtc.SDPTypeAnswer
case "rollback":
stype = webrtc.SDPTypeRollback
}
return &webrtc.SessionDescription{
Type: stype,
SDP: parsed["sdp"].(string),
}, nil
}
// 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) ||
// Carrier-Grade NAT as per https://tools.ietf.org/htm/rfc6598
(ip4[0] == 100 && ip4[1]&0xc0 == 64) ||
// Dynamic Configuration as per https://tools.ietf.org/htm/rfc3927
(ip4[0] == 169 && ip4[1] == 254)
}
// 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() {
c, err := ice.UnmarshalCandidate(a.Value)
if err == nil && c.Type() == ice.CandidateTypeHost {
ip := net.ParseIP(c.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)
}
|
