Parse.ipFromSDP function.

proxy/spec/util.spec.coffee

@@ -90,6 +90,117 @@ describe 'Parse', ->
       expect Parse.address '[1:2::ffff:1.2.3.4]:4444'
         .toEqual { host: '1:2::ffff:1.2.3.4', port: 4444 }
 
+  describe 'ipFromSDP', ->
+    testCases = [
+      # https://tools.ietf.org/html/rfc4566#section-5
+      sdp: """
+           v=0
+           o=jdoe 2890844526 2890842807 IN IP4 10.47.16.5
+           s=SDP Seminar
+           i=A Seminar on the session description protocol
+           u=http://www.example.com/seminars/sdp.pdf
+           e=j.doe@example.com (Jane Doe)
+           c=IN IP4 224.2.17.12/127
+           t=2873397496 2873404696
+           a=recvonly
+           m=audio 49170 RTP/AVP 0
+           m=video 51372 RTP/AVP 99
+           a=rtpmap:99 h263-1998/90000
+           """
+      expected: '224.2.17.12'
+    ,
+      # Missing c= line
+      sdp: """
+           v=0
+           o=jdoe 2890844526 2890842807 IN IP4 10.47.16.5
+           s=SDP Seminar
+           i=A Seminar on the session description protocol
+           u=http://www.example.com/seminars/sdp.pdf
+           e=j.doe@example.com (Jane Doe)
+           t=2873397496 2873404696
+           a=recvonly
+           m=audio 49170 RTP/AVP 0
+           m=video 51372 RTP/AVP 99
+           a=rtpmap:99 h263-1998/90000
+           """
+      expected: undefined
+    ,
+      # Single line, IP address only
+      sdp: "c=IN IP4 224.2.1.1\n"
+      expected: '224.2.1.1'
+    ,
+      # Same, with TTL
+      sdp: "c=IN IP4 224.2.1.1/127\n"
+      expected: '224.2.1.1'
+    ,
+      # Same, with TTL and multicast addresses
+      sdp: "c=IN IP4 224.2.1.1/127/3\n"
+      expected: '224.2.1.1'
+    ,
+      # IPv6, address only
+      sdp: "c=IN IP6 FF15::101\n"
+      expected: 'ff15::101'
+    ,
+      # Same, with multicast addresses
+      sdp: "c=IN IP6 FF15::101/3\n"
+      expected: 'ff15::101'
+    ,
+      # Multiple c= lines
+      sdp: """
+           c=IN IP4 1.2.3.4
+           c=IN IP4 5.6.7.8
+           """
+      expected: '1.2.3.4'
+    ,
+      # Modified from SDP sent by snowflake-client.
+      sdp: """
+           v=0
+           o=- 7860378660295630295 2 IN IP4 127.0.0.1
+           s=-
+           t=0 0
+           a=group:BUNDLE data
+           a=msid-semantic: WMS
+           m=application 54653 DTLS/SCTP 5000
+           c=IN IP4 1.2.3.4
+           a=candidate:3581707038 1 udp 2122260223 192.168.0.1 54653 typ host generation 0 network-id 1 network-cost 50
+           a=candidate:2617212910 1 tcp 1518280447 192.168.0.1 59673 typ host tcptype passive generation 0 network-id 1 network-cost 50
+           a=candidate:2082671819 1 udp 1686052607 1.2.3.4 54653 typ srflx raddr 192.168.0.1 rport 54653 generation 0 network-id 1 network-cost 50
+           a=ice-ufrag:IBdf
+           a=ice-pwd:G3lTrrC9gmhQx481AowtkhYz
+           a=fingerprint:sha-256 53:F8:84:D9:3C:1F:A0:44:AA:D6:3C:65:80:D3:CB:6F:23:90:17:41:06:F9:9C:10:D8:48:4A:A8:B6:FA:14:A1
+           a=setup:actpass
+           a=mid:data
+           a=sctpmap:5000 webrtc-datachannel 1024
+           """
+      expected: '1.2.3.4'
+    ,
+      # Improper character within IPv4
+      sdp: """
+           c=IN IP4 224.2z.1.1
+           """
+      expected: undefined
+    ,
+      # Improper character within IPv6
+      sdp: """
+           c=IN IP6 ff15:g::101
+           """
+      expected: undefined
+    ,
+      # Bogus "IP7" addrtype
+      sdp: "c=IN IP7 1.2.3.4\n"
+      expected: undefined
+    ]
+
+    it 'parses SDP', ->
+      for test in testCases
+        # https://tools.ietf.org/html/rfc4566#section-5: "The sequence # CRLF
+        # (0x0d0a) is used to end a record, although parsers SHOULD be tolerant
+        # and also accept records terminated with a single newline character."
+        # We represent the test cases with LF line endings for convenience, and
+        # test them both that way and with CRLF line endings.
+        expect(Parse.ipFromSDP(test.sdp)?.toLowerCase()).toEqual(test.expected)
+        expect(Parse.ipFromSDP(test.sdp.replace(/\n/, "\r\n"))?.toLowerCase()).toEqual(test.expected)
+
 describe 'query string', ->
   it 'should parse correctly', ->
     expect Query.parse ''

proxy/util.coffee

@@ -112,6 +112,17 @@ Parse =
       return null if null == units
     count * Number(units)
 
+  # Parse a connection-address out of the "c=" Connection Data field of a session
+  # description. Return undefined if none is found.
+  # https://tools.ietf.org/html/rfc4566#section-5.7
+  ipFromSDP: (sdp) ->
+    for pattern in [
+      /^c=IN IP4 ([\d.]+)(?:(?:\/\d+)?\/\d+)?(:? |$)/m,
+      /^c=IN IP6 ([0-9A-Fa-f:.]+)(?:\/\d+)?(:? |$)/m,
+    ]
+      m = pattern.exec(sdp)
+      return m[1] if m?
+
 
 Params =
   getBool: (query, param, defaultValue) ->