196.6.2.2 Tracepunkt TCP

Tabelle 50

Struktur der Aufzeichnung am Tracepunkt TCP

Offset	Data item byte0              byte1	byte order	Comments
0	IP address of remote host	hi, lo	vgl. Bild  auf Seite 2616
4	local port	hi, lo
6	remote port	hi, lo
8	TCP location	lo, hi	vgl. Tabelle 51 auf Seite 2622
10	TCP event	lo, hi
12	socket state after	lo, hi	socket state after event processing vgl. Tabelle 53 auf Seite 2623
14	connection state before	lo, hi	connection state before processing the event; vgl. Tabelle 54 auf Seite 2623
16	actual chars in buffer	lo, hi	if the location is TA_INPUT or TA_DROP, this items refers to the receive buffer, otherwise to the send buffer
20	allocated memory	lo, hi	total memory allocated by mbufs and clusters (1 mbuf=256 byte, 1 clusters=1518 byte)
24	connection state after	lo, hi	connection state after event processing vgl. Tabelle 54 auf Seite 2623
26	retransmit timer	lo, hi	Ticks to retransmit the data starting at "Seq-Nr: send unacknowledged" Note: 1 Tick = 0,5 sec.
28	persist timer	lo, hi	Ticks to send next data probe
30	keepalive timer	lo, hi	Ticks to send next keep-alive packet
32	number retransmissions	lo, hi	rexmit backoff idx
34	current rexmit interval	lo, hi	current retransmission interval
36	Seq-Nr: send unackn.	lo, hi	Sequence number send unacknowledged
40	Seq-Nr: send next	lo, hi	Sequence number send next
44	send window	lo, hi	max. number of unacknowledged bytes
46	Seq-Nr: receive next	lo, hi	Sequence number receive next
48
50	receive window	lo, hi	amount of receive capacity (actually)
52	advertised rcv window	lo, hi	advertised receive window

Tabelle 51

Tracepunkte und ihre möglichen TCP Ereignisse

Value lo,hi	trace location	TCP events	comment
01 00	TA_USER	PRU_ATTACH	attach protocol to socket
		PRU_DETACH	detach protocol from socket
		PRU_BIND	bind socket to address
		PRU_LISTEN	listen for connection
		PRU_CONNECT	establish connection to peer
		PRU_ACCEPT	accept connection from peer
		PRU_DISCONNECT	disconnect from peer
		PRU_ABORT	abort (fast DISCONNECT, DETATCH)
		PRU_SLOWTIMO	500ms timeout
02 00	TA_OUTPUT	TCP-Flags + length of user data in WORDS	see TA_INPUT
03 00	TA_INPUT	TCP-Flags + length of user data in WORDS	the TCP-Flags (see Tabelle 55 auf Seite 2624) of received TCP packet will be saved into the Intel bits 0 - 5 of byte 0 in TCP event, the length of user data -counted in words- will be saved into the bits 6,7 of byte 0 and bits 0 - 7 of byte 1 (most significant byte)
04 00	TA_DROP	TCP-Flags + cause for dropping	analogous to TA_INPUT; the possible values of cause for dropping are listed in Tabelle 52 auf Seite 2623
05 00	TA_DROPAFTERACK	TCP-Flags + cause for dropping	analogous to TA_INPUT; the possible values of cause for dropping are listed in Tabelle 52 auf Seite 2623
06 00	TA_DROPWITHRST	TCP-Flags + cause for dropping	analogous to TA_INPUT; the possible values of cause for dropping are listed in Tabelle 52 auf Seite 2623

Tabelle 52

Gründe für den Ausfall eines TCP Paketes und / oder einer Verbindung

Value	Literal	comment
1	TD_NOBUF	required memory resources not available
2	TD_NEWSOFAILED	creation of new socket failed due to no socket space
3	TD_TCPFLAG	unexpected flag received
4	TD_PCBFAILED	call of in_pcbconnect failed
5	TD_SEQFAIL	unexpected sequence number received
6	TD_CONNCLOSED	connection already closed
7	TD_WAITFIN	TCP waits for the FIN of communication partner

Tabelle 53

Bits der Socket-Zustände

Intel- Bit	Value lo, hi	Name	Comment
0	01 00	SS_NOFDREF	no file table ref any more
1	02 00	SS_ISCONNECTED	socket connected to a peer
2	04 00	SS_ISCONNECTING	in process of connecting to peer
3	08 00	SS_ISDISCONNECTING	in process of disconnecting
4	10 00	SS_CANTSENDMORE	can’t send more data to peer
5	20 00	SS_CANTRCVMORE	can’t receive more data from peer
6	40 00	SS_RCVATMARK	at mark on input
7	80 00	SS_PRIV	privileged for broadcast
8	00 01	SS_NBIO	non-blocking ops
9	00 02	SS_ASYNC	async i/o notify
10	00 04	SS_ISCONFIRMING	deciding to accept connection req

Tabelle 54

Definitionen der Zustände des TCP FMS. Per RFC793, September, 1981.

Value lo, hi	Name	Comment
00 00	TCPS_CLOSED	connection closed
01 00	TCPS_LISTEN	listening for connection
02 00	TCPS_SYN_SENT	active - have sent SYN
03 00	TCPS_SYN_RECEIVED	has send and received SYN
04 00	TCPS_ESTABLISHED	connection established
05 00	TCPS_CLOSE_WAIT	received FIN - waiting for close
06 00	TCPS_FIN_WAIT_1	has closed - sent FIN
07 00	TCPS_CLOSING	closed an FIN exchanged - await FIN ACK
08 00	TCPS_LAST_ACK	had FIN and close - await FIN ACK
09 00	TCPS_FIN_WAIT_2	has closed - FIN is acked
0A 00	TCPS_TIME_WAIT	quiet wait after close

Tabelle 55

TCP Flags und ihre Bedeutung

Bit nr:1	Bit 5 (10)	Bit 4 (11)	Bit 3 (12)	Bit 2 (13)	Bit 1 (14)	Bit 0 (15)
Value:	H’20	H’10	H’08	H’04	H’02’	H’01
Name:	URG	ACK	PUSH	RST	SYN	FIN
Description:	Urgent Pointer field is significant	Acknowledgment field is significant	Push Function	Reset (Close) the connection	Synchr. sequence numbers; start connection	No more data from sender; connection close

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