Websockify gibt keine Informationen weiter, die Verbindung wird vorzeitig abgebrochen

Ich muss websockifyals Proxy verwenden. Das endgültige Setup wird sein:

• Ein Websocket auf einer Webseite stellt eine Verbindung zum websockifyServer auf demselben Computer her
• websockify Server initiiert die Verbindung mit einem TCP-Socket-Programm, das an einem anderen Ort überwacht wird (in diesem Fall auf demselben Computer)
• TCP-Socket empfängt Informationen, führt Berechnungen durch, Antworten websockify
• websockify ruft die Antwort ab und sendet die Informationen an den Socket auf der Webseite
• Die Antwort wird im Browser des Benutzers angezeigt

Aus irgendeinem Grund websockifylehnt es jedoch ab, die Informationen weiterzugeben, und empfängt die FIN-Nachricht früher als erwartet. Websockify sagt "Nicht unterstützt: Unbekannter Opcode 0x01".

Um diesen Fall zu untersuchen, habe ich eine MWE erstellt und den Verkehr mit abgefangen tcpdump.

Das Setup ist wie folgt:

• Erstens werde ich ausgeführt netcat -v -v -l -p 40000- dies ist die Anwendung, die wir die Informationen erhalten möchten

• Dann websockify --verbose 50000 localhost:40000renne ich - das ist der Proxybefehl

• Zum Schluss laufe ich wscat -c localhost:50000- das ist eine App, die eine Websocket-Verbindung zum websockifyProxy herstellt

Sobald ich etwas mit sende wscat, wird wscatdie Verbindung mit dem Code 1003 abgebrochen. RFC 6455 zitiert :

1003 gibt an, dass ein Endpunkt die Verbindung beendet, weil er einen Datentyp empfangen hat, den er nicht annehmen kann (z. B. ein Endpunkt, der nur Textdaten versteht, diese möglicherweise senden kann, wenn er eine binäre Nachricht empfängt).

Hier ist die visuelle Darstellung dieses Setups (die Erorr-Meldung 'Disconnected from closed 1003' ist so geschrieben, weil ich die Quelle manuell geändert habe, um weitere Informationen zur Unterbrechung zu erhalten):

Hier ist die Darstellung der Daten von Wireshark:

und hier sind die Pakete mit den Nummern 11,12,13 und 14, die meine Aufmerksamkeit erregt haben:

Frame 11: 81 bytes on wire (648 bits), 81 bytes captured (648 bits) Encapsulation type: Ethernet (1) Arrival Time: Sep 19, 2017 20:35:46.491762000 CEST [Time shift for this packet: 0.000000000 seconds] Epoch Time: 1505846146.491762000 seconds [Time delta from previous captured frame: 3.788711000 seconds] [Time delta from previous displayed frame: 3.788711000 seconds] [Time since reference or first frame: 3.887638000 seconds] Frame Number: 11 Frame Length: 81 bytes (648 bits) Capture Length: 81 bytes (648 bits) [Frame is marked: False] [Frame is ignored: False] [Protocols in frame: eth:ethertype:ip:tcp:http:websocket:data-text-lines] Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00) Destination: 00:00:00_00:00:00 (00:00:00:00:00:00) Address: 00:00:00_00:00:00 (00:00:00:00:00:00) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Source: 00:00:00_00:00:00 (00:00:00:00:00:00) Address: 00:00:00_00:00:00 (00:00:00:00:00:00) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Type: IPv4 (0x0800) Internet Protocol Version 4, Src: 127.0.0.1, Dst: 127.0.0.1 0100 .... = Version: 4 .... 0101 = Header Length: 20 bytes (5) Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT) 0000 00.. = Differentiated Services Codepoint: Default (0) .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0) Total Length: 67 Identification: 0x1581 (5505) Flags: 0x02 (Don't Fragment) 0... .... = Reserved bit: Not set .1.. .... = Don't fragment: Set ..0. .... = More fragments: Not set Fragment offset: 0 Time to live: 64 Protocol: TCP (6) Header checksum: 0x2732 [validation disabled] [Header checksum status: Unverified] Source: 127.0.0.1 Destination: 127.0.0.1 [Source GeoIP: Unknown] [Destination GeoIP: Unknown] TCP Src Port: 53832, Dst Port: 50000, Seq: 225, Ack: 130, Len: 15 Src Port: 53832 Dest Port: 50000 [Stream index: 0] [TCP Segment Len: 15] Sequence number: 225 (relative sequence number) [Next sequence number: 240 (relative sequence number)] Acknowledgment number: 130 (relative ack number) 1000 .... = Header Length: 32 bytes (8) Flags: 0x018 (PSH, ACK) 000. .... .... = Reserved: Not set ...0 .... .... = Nonce: Not set .... 0... .... = Congestion Window Reduced (CWR): Not set .... .0.. .... = ECN-Echo: Not set .... ..0. .... = Urgent: Not set .... ...1 .... = Acknowledgment: Set .... .... 1... = Push: Set .... .... .0.. = Reset: Not set .... .... ..0. = Syn: Not set .... .... ...0 = Fin: Not set [TCP Flags: ·······AP···] Window size value: 350 [Calculated window size: 44800] [Window size scaling factor: 128] Checksum: 0xfe37 [unverified] [Checksum Status: Unverified] Urgent pointer: 0 Options: (12 bytes), No-Operation (NOP), No-Operation (NOP), Timestamps TCP Option - No-Operation (NOP) Kind: No-Operation (1) TCP Option - No-Operation (NOP) Kind: No-Operation (1) TCP Option - Timestamps: TSval 1764320477, TSecr 1764319312 Kind: Time Stamp Option (8) Length: 10 Timestamp value: 1764320477 Timestamp echo reply: 1764319312 [SEQ/ACK analysis] [iRTT: 0.000021000 seconds] [Bytes in flight: 15] [Bytes sent since last PSH flag: 15] TCP payload (15 bytes) [PDU Size: 15] WebSocket 1... .... = Fin: True .000 .... = Reserved: 0x0 .... 0001 = Opcode: Text (1) 1... .... = Mask: True .000 1001 = Payload length: 9 Masking-Key: 2f0bda1c Masked payload Payload Line-based text data alamakota  Frame 12: 102 bytes on wire (816 bits), 102 bytes captured (816 bits) Encapsulation type: Ethernet (1) Arrival Time: Sep 19, 2017 20:35:46.492378000 CEST [Time shift for this packet: 0.000000000 seconds] Epoch Time: 1505846146.492378000 seconds [Time delta from previous captured frame: 0.000616000 seconds] [Time delta from previous displayed frame: 0.000616000 seconds] [Time since reference or first frame: 3.888254000 seconds] Frame Number: 12 Frame Length: 102 bytes (816 bits) Capture Length: 102 bytes (816 bits) [Frame is marked: False] [Frame is ignored: False] [Protocols in frame: eth:ethertype:ip:tcp:http:websocket] Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00) Destination: 00:00:00_00:00:00 (00:00:00:00:00:00) Address: 00:00:00_00:00:00 (00:00:00:00:00:00) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Source: 00:00:00_00:00:00 (00:00:00:00:00:00) Address: 00:00:00_00:00:00 (00:00:00:00:00:00) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Type: IPv4 (0x0800) Internet Protocol Version 4, Src: 127.0.0.1, Dst: 127.0.0.1 0100 .... = Version: 4 .... 0101 = Header Length: 20 bytes (5) Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT) 0000 00.. = Differentiated Services Codepoint: Default (0) .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0) Total Length: 88 Identification: 0xd42e (54318) Flags: 0x02 (Don't Fragment) 0... .... = Reserved bit: Not set .1.. .... = Don't fragment: Set ..0. .... = More fragments: Not set Fragment offset: 0 Time to live: 64 Protocol: TCP (6) Header checksum: 0x686f [validation disabled] [Header checksum status: Unverified] Source: 127.0.0.1 Destination: 127.0.0.1 [Source GeoIP: Unknown] [Destination GeoIP: Unknown] TCP Src Port: 50000, Dst Port: 53832, Seq: 130, Ack: 240, Len: 36 Src Port: 50000 Dest Port: 53832 [Stream index: 0] [TCP Segment Len: 36] Sequence number: 130 (relative sequence number) [Next sequence number: 166 (relative sequence number)] Acknowledgment number: 240 (relative ack number) 1000 .... = Header Length: 32 bytes (8) Flags: 0x018 (PSH, ACK) 000. .... .... = Reserved: Not set ...0 .... .... = Nonce: Not set .... 0... .... = Congestion Window Reduced (CWR): Not set .... .0.. .... = ECN-Echo: Not set .... ..0. .... = Urgent: Not set .... ...1 .... = Acknowledgment: Set .... .... 1... = Push: Set .... .... .0.. = Reset: Not set .... .... ..0. = Syn: Not set .... .... ...0 = Fin: Not set [TCP Flags: ·······AP···] Window size value: 350 [Calculated window size: 44800] [Window size scaling factor: 128] Checksum: 0xfe4c [unverified] [Checksum Status: Unverified] Urgent pointer: 0 Options: (12 bytes), No-Operation (NOP), No-Operation (NOP), Timestamps TCP Option - No-Operation (NOP) Kind: No-Operation (1) TCP Option - No-Operation (NOP) Kind: No-Operation (1) TCP Option - Timestamps: TSval 1764320478, TSecr 1764320477 Kind: Time Stamp Option (8) Length: 10 Timestamp value: 1764320478 Timestamp echo reply: 1764320477 [SEQ/ACK analysis] [This is an ACK to the segment in frame: 11] [The RTT to ACK the segment was: 0.000616000 seconds] [iRTT: 0.000021000 seconds] [Bytes in flight: 36] [Bytes sent since last PSH flag: 36] TCP payload (36 bytes) [PDU Size: 36] WebSocket 1... .... = Fin: True .000 .... = Reserved: 0x0 .... 1000 = Opcode: Connection Close (8) 0... .... = Mask: False .010 0010 = Payload length: 34 Payload Close Status code: Unsupported Data (1003) Reason: Unsupported: Unknown opcode 0x01  Frame 13: 66 bytes on wire (528 bits), 66 bytes captured (528 bits) Encapsulation type: Ethernet (1) Arrival Time: Sep 19, 2017 20:35:46.492394000 CEST [Time shift for this packet: 0.000000000 seconds] Epoch Time: 1505846146.492394000 seconds [Time delta from previous captured frame: 0.000016000 seconds] [Time delta from previous displayed frame: 0.000016000 seconds] [Time since reference or first frame: 3.888270000 seconds] Frame Number: 13 Frame Length: 66 bytes (528 bits) Capture Length: 66 bytes (528 bits) [Frame is marked: False] [Frame is ignored: False] [Protocols in frame: eth:ethertype:ip:tcp] Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00) Destination: 00:00:00_00:00:00 (00:00:00:00:00:00) Address: 00:00:00_00:00:00 (00:00:00:00:00:00) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Source: 00:00:00_00:00:00 (00:00:00:00:00:00) Address: 00:00:00_00:00:00 (00:00:00:00:00:00) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Type: IPv4 (0x0800) Internet Protocol Version 4, Src: 127.0.0.1, Dst: 127.0.0.1 0100 .... = Version: 4 .... 0101 = Header Length: 20 bytes (5) Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT) 0000 00.. = Differentiated Services Codepoint: Default (0) .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0) Total Length: 52 Identification: 0x1582 (5506) Flags: 0x02 (Don't Fragment) 0... .... = Reserved bit: Not set .1.. .... = Don't fragment: Set ..0. .... = More fragments: Not set Fragment offset: 0 Time to live: 64 Protocol: TCP (6) Header checksum: 0x2740 [validation disabled] [Header checksum status: Unverified] Source: 127.0.0.1 Destination: 127.0.0.1 [Source GeoIP: Unknown] [Destination GeoIP: Unknown] TCP Src Port: 53832, Dst Port: 50000, Seq: 240, Ack: 166, Len: 0 Src Port: 53832 Dest Port: 50000 [Stream index: 0] [TCP Segment Len: 0] Sequence number: 240 (relative sequence number) Acknowledgment number: 166 (relative ack number) 1000 .... = Header Length: 32 bytes (8) Flags: 0x010 (ACK) 000. .... .... = Reserved: Not set ...0 .... .... = Nonce: Not set .... 0... .... = Congestion Window Reduced (CWR): Not set .... .0.. .... = ECN-Echo: Not set .... ..0. .... = Urgent: Not set .... ...1 .... = Acknowledgment: Set .... .... 0... = Push: Not set .... .... .0.. = Reset: Not set .... .... ..0. = Syn: Not set .... .... ...0 = Fin: Not set [TCP Flags: ·······A····] Window size value: 350 [Calculated window size: 44800] [Window size scaling factor: 128] Checksum: 0xfe28 [unverified] [Checksum Status: Unverified] Urgent pointer: 0 Options: (12 bytes), No-Operation (NOP), No-Operation (NOP), Timestamps TCP Option - No-Operation (NOP) Kind: No-Operation (1) TCP Option - No-Operation (NOP) Kind: No-Operation (1) TCP Option - Timestamps: TSval 1764320478, TSecr 1764320478 Kind: Time Stamp Option (8) Length: 10 Timestamp value: 1764320478 Timestamp echo reply: 1764320478 [SEQ/ACK analysis] [This is an ACK to the segment in frame: 12] [The RTT to ACK the segment was: 0.000016000 seconds] [iRTT: 0.000021000 seconds]  Frame 14: 106 bytes on wire (848 bits), 106 bytes captured (848 bits) Encapsulation type: Ethernet (1) Arrival Time: Sep 19, 2017 20:35:46.494661000 CEST [Time shift for this packet: 0.000000000 seconds] Epoch Time: 1505846146.494661000 seconds [Time delta from previous captured frame: 0.002267000 seconds] [Time delta from previous displayed frame: 0.002267000 seconds] [Time since reference or first frame: 3.890537000 seconds] Frame Number: 14 Frame Length: 106 bytes (848 bits) Capture Length: 106 bytes (848 bits) [Frame is marked: False] [Frame is ignored: False] [Protocols in frame: eth:ethertype:ip:tcp:http:websocket] Ethernet II, Src: 00:00:00_00:00:00 (00:00:00:00:00:00), Dst: 00:00:00_00:00:00 (00:00:00:00:00:00) Destination: 00:00:00_00:00:00 (00:00:00:00:00:00) Address: 00:00:00_00:00:00 (00:00:00:00:00:00) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Source: 00:00:00_00:00:00 (00:00:00:00:00:00) Address: 00:00:00_00:00:00 (00:00:00:00:00:00) .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default) .... ...0 .... .... .... .... = IG bit: Individual address (unicast) Type: IPv4 (0x0800) Internet Protocol Version 4, Src: 127.0.0.1, Dst: 127.0.0.1 0100 .... = Version: 4 .... 0101 = Header Length: 20 bytes (5) Differentiated Services Field: 0x00 (DSCP: CS0, ECN: Not-ECT) 0000 00.. = Differentiated Services Codepoint: Default (0) .... ..00 = Explicit Congestion Notification: Not ECN-Capable Transport (0) Total Length: 92 Identification: 0x1583 (5507) Flags: 0x02 (Don't Fragment) 0... .... = Reserved bit: Not set .1.. .... = Don't fragment: Set ..0. .... = More fragments: Not set Fragment offset: 0 Time to live: 64 Protocol: TCP (6) Header checksum: 0x2717 [validation disabled] [Header checksum status: Unverified] Source: 127.0.0.1 Destination: 127.0.0.1 [Source GeoIP: Unknown] [Destination GeoIP: Unknown] TCP Src Port: 53832, Dst Port: 50000, Seq: 240, Ack: 166, Len: 40 Src Port: 53832 Dest Port: 50000 [Stream index: 0] [TCP Segment Len: 40] Sequence number: 240 (relative sequence number) [Next sequence number: 280 (relative sequence number)] Acknowledgment number: 166 (relative ack number) 1000 .... = Header Length: 32 bytes (8) Flags: 0x018 (PSH, ACK) 000. .... .... = Reserved: Not set ...0 .... .... = Nonce: Not set .... 0... .... = Congestion Window Reduced (CWR): Not set .... .0.. .... = ECN-Echo: Not set .... ..0. .... = Urgent: Not set .... ...1 .... = Acknowledgment: Set .... .... 1... = Push: Set .... .... .0.. = Reset: Not set .... .... ..0. = Syn: Not set .... .... ...0 = Fin: Not set [TCP Flags: ·······AP···] Window size value: 350 [Calculated window size: 44800] [Window size scaling factor: 128] Checksum: 0xfe50 [unverified] [Checksum Status: Unverified] Urgent pointer: 0 Options: (12 bytes), No-Operation (NOP), No-Operation (NOP), Timestamps TCP Option - No-Operation (NOP) Kind: No-Operation (1) TCP Option - No-Operation (NOP) Kind: No-Operation (1) TCP Option - Timestamps: TSval 1764320478, TSecr 1764320478 Kind: Time Stamp Option (8) Length: 10 Timestamp value: 1764320478 Timestamp echo reply: 1764320478 [SEQ/ACK analysis] [iRTT: 0.000021000 seconds] [Bytes in flight: 40] [Bytes sent since last PSH flag: 40] TCP payload (40 bytes) [PDU Size: 40] WebSocket 1... .... = Fin: True .000 .... = Reserved: 0x0 .... 1000 = Opcode: Connection Close (8) 1... .... = Mask: True .010 0010 = Payload length: 34 Masking-Key: 3daec4d6 Masked payload Payload Close Status code: Unsupported Data (1003) Reason: Unsupported: Unknown opcode 0x01 

Es scheint, als würde wscatein Opcode (0x1) gesendet, der websockifyals 0x01 verstanden wird und nicht erkennt, aber ich weiß nicht warum.

Wie mache ich das Setup? Ich habe versucht, eine Verbindung websockifymit verschiedenen Programmen herzustellen (Browser-Websocket-Implementierung, wscatAlternativen), aber alle schlagen fehl.