WebSVN – Kolibri OS – Blame – /kernel/branches/net/network/tcp.inc

Rev	Author	Line No.	Line
1196	hidnplayr	1	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
		2	;; ;;
1514	hidnplayr	3	;; Copyright (C) KolibriOS team 2004-2010. All rights reserved. ;;
1196	hidnplayr	4	;; Distributed under terms of the GNU General Public License ;;
		5	;; ;;
		6	;; TCP.INC ;;
		7	;; ;;
		8	;; Part of the tcp/ip network stack for KolibriOS ;;
		9	;; ;;
1514	hidnplayr	10	;; Written by hidnplayr@kolibrios.org ;;
1196	hidnplayr	11	;; ;;
1514	hidnplayr	12	;; Based on the code of 4.4BSD ;;
		13	;; ;;
1196	hidnplayr	14	;; GNU GENERAL PUBLIC LICENSE ;;
		15	;; Version 2, June 1991 ;;
		16	;; ;;
		17	;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
1159	hidnplayr	18
1206	hidnplayr	19	$Revision: 1534 $
1159	hidnplayr	20
1514	hidnplayr	21	; Socket states
		22	TCB_CLOSED equ 0
		23	TCB_LISTEN equ 1
		24	TCB_SYN_SENT equ 2
		25	TCB_SYN_RECEIVED equ 3
		26	TCB_ESTABLISHED equ 4
		27	TCB_CLOSE_WAIT equ 5
		28	TCB_FIN_WAIT_1 equ 6
		29	TCB_CLOSING equ 7
		30	TCB_LAST_ACK equ 8
		31	TCB_FIN_WAIT_2 equ 9
		32	TCB_TIMED_WAIT equ 10
1196	hidnplayr	33
1514	hidnplayr	34	; Socket Flags
		35	TF_ACKNOW equ 1 shl 0 ; ack peer immediately
		36	TF_DELACK equ 1 shl 1 ; ack, but try to delay it
		37	TF_NODELAY equ 1 shl 2 ; don't delay packets to coalesce
		38	TF_NOOPT equ 1 shl 3 ; don't use tcp options
		39	TF_SENTFIN equ 1 shl 4 ; have sent FIN
		40	TF_REQ_SCALE equ 1 shl 5 ; have/will request window scaling
		41	TF_RCVD_SCALE equ 1 shl 6 ; other side has requested scaling
		42	TF_REQ_TSTMP equ 1 shl 7 ; have/will request timestamps
		43	TF_RCVD_TSTMP equ 1 shl 8 ; a timestamp was received in SYN
		44	TF_SACK_PERMIT equ 1 shl 9 ; other side said I could SACK
1249	hidnplayr	45
1514	hidnplayr	46	; Segment flags
		47	TH_FIN equ 1 shl 0
		48	TH_SYN equ 1 shl 1
		49	TH_RST equ 1 shl 2
		50	TH_PUSH equ 1 shl 3
		51	TH_ACK equ 1 shl 4
		52	TH_URG equ 1 shl 5
1318	hidnplayr	53
1514	hidnplayr	54	; Segment header options
		55	TCP_OPT_EOL equ 0 ; End of option list.
		56	TCP_OPT_NOP equ 1 ; No-Operation.
		57	TCP_OPT_MAXSEG equ 2 ; Maximum Segment Size.
		58	TCP_OPT_WINDOW equ 3 ; window scale
		59	TCP_OPT_TIMESTAMP equ 8
		60
1519	hidnplayr	61	; Fundamental timer values
		62	TCP_time_MSL equ 47 ; max segment lifetime (30s)
		63	TCP_time_re_min equ 2 ; min retransmission (1,28s)
		64	TCP_time_re_max equ 100 ; max retransmission (64s)
		65	TCP_time_pers_min equ 8 ; min persist (5,12s)
		66	TCP_time_pers_max equ 94 ; max persist (60,16s)
		67	TCP_time_keep_init equ 118 ; connectione stablishment (75,52s)
		68	TCP_time_keep_idle equ 4608 ; idle time before 1st probe (2h)
		69	TCP_time_keep_interval equ 118 ; between probes when no response (75,52s)
		70	TCP_time_rtt_default equ 5 ; default Round Trip Time (3,2s)
		71
		72	; timer constants
		73	TCP_max_rxtshift equ 12 ; max retransmissions waiting for ACK
		74	TCP_max_keepcnt equ 8 ; max keepalive probes
		75
1529	hidnplayr	76	;
		77	TCP_max_winshift equ 14
		78	TCP_max_win equ 65535
1519	hidnplayr	79
1514	hidnplayr	80	struct TCP_segment
1159	hidnplayr	81	.SourcePort dw ?
		82	.DestinationPort dw ?
		83	.SequenceNumber dd ?
		84	.AckNumber dd ?
1196	hidnplayr	85	.DataOffset db ? ; DataOffset[0-3 bits] and Reserved[4-7]
		86	.Flags db ? ; Reserved[0-1 bits]\|URG\|ACK\|PSH\|RST\|SYN\|FIN
1159	hidnplayr	87	.Window dw ?
		88	.Checksum dw ?
		89	.UrgentPointer dw ?
1514	hidnplayr	90	.Data: ; ..or options
1159	hidnplayr	91	ends
		92
1274	hidnplayr	93	struct tcp_in_queue_entry
		94	.data_ptr dd ?
		95	.data_size dd ?
1514	hidnplayr	96	.offset dd ?
1274	hidnplayr	97	.size:
		98	ends
		99
		100	struct tcp_out_queue_entry
		101	.data_ptr dd ?
		102	.data_size dd ?
1514	hidnplayr	103
1274	hidnplayr	104	.size:
		105	ends
		106
1196	hidnplayr	107	align 4
		108	uglobal
1514	hidnplayr	109	TCP_segments_tx rd IP_MAX_INTERFACES
		110	TCP_segments_rx rd IP_MAX_INTERFACES
		111	TCP_bytes_rx rq IP_MAX_INTERFACES
		112	TCP_bytes_tx rq IP_MAX_INTERFACES
		113	TCP_sequence_num dd ?
1196	hidnplayr	114	endg
		115
		116
		117	;-----------------------------------------------------------------
		118	;
		119	; TCP_init
		120	;
		121	; This function resets all TCP variables
		122	;
		123	;-----------------------------------------------------------------
1529	hidnplayr	124	macro TCP_init {
1196	hidnplayr	125
		126	xor eax, eax
1514	hidnplayr	127	mov edi, TCP_segments_tx
		128	mov ecx, (6*IP_MAX_INTERFACES)
1196	hidnplayr	129	rep stosd
		130
1529	hidnplayr	131	pseudo_random eax
		132	mov [TCP_sequence_num], eax
1196	hidnplayr	133
1529	hidnplayr	134	}
1196	hidnplayr	135
		136
1519	hidnplayr	137	;----------------------
1196	hidnplayr	138	;
1159	hidnplayr	139	;
1519	hidnplayr	140	;----------------------
1529	hidnplayr	141	macro TCP_timer_160ms {
1159	hidnplayr	142
1529	hidnplayr	143	local .loop
		144	local .exit
		145
1514	hidnplayr	146	mov eax, net_sockets
		147	.loop:
		148	mov eax, [eax + SOCKET.NextPtr]
		149	or eax, eax
1159	hidnplayr	150	jz .exit
		151
1514	hidnplayr	152	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		153	jne .loop
1249	hidnplayr	154
1519	hidnplayr	155	dec [eax + TCP_SOCKET.timer_ack]
1514	hidnplayr	156	jnz .loop
1159	hidnplayr	157
1519	hidnplayr	158	DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
1159	hidnplayr	159
1519	hidnplayr	160	push eax
1529	hidnplayr	161	call TCP_respond_socket
1514	hidnplayr	162	pop eax
1159	hidnplayr	163
1519	hidnplayr	164	jmp .loop
1159	hidnplayr	165
		166	.exit:
1519	hidnplayr	167
1529	hidnplayr	168	}
1159	hidnplayr	169
		170
1519	hidnplayr	171	;-----------------------------------------------------------------
1159	hidnplayr	172	;
		173	;
1519	hidnplayr	174	;-----------------------------------------------------------------
1529	hidnplayr	175	macro TCP_timer_640ms {
1159	hidnplayr	176
1529	hidnplayr	177	local .loop
		178	local .exit
		179
1519	hidnplayr	180	; Update TCP sequence number
		181
1514	hidnplayr	182	add [TCP_sequence_num], 64000
1159	hidnplayr	183
1519	hidnplayr	184	; scan through all the active TCP sockets, decrementing ALL timers
		185	; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires
1159	hidnplayr	186
1519	hidnplayr	187	mov eax, net_sockets
		188	.loop:
		189	mov eax, [eax + SOCKET.NextPtr]
		190	.check_only:
		191	or eax, eax
		192	jz .exit
1159	hidnplayr	193
1519	hidnplayr	194	cmp [eax + SOCKET.Type], IP_PROTO_TCP
		195	jne .loop
1159	hidnplayr	196
1529	hidnplayr	197	inc [eax + TCP_SOCKET.t_idle]
		198	dec [eax + TCP_SOCKET.timer_retransmission]
1519	hidnplayr	199	jnz .check_more2
1254	hidnplayr	200
1519	hidnplayr	201	DEBUGF 1,"socket %x: Retransmission timer expired\n", eax
1159	hidnplayr	202
1519	hidnplayr	203	push eax
		204	call TCP_output
		205	pop eax
1159	hidnplayr	206
1519	hidnplayr	207	.check_more2:
		208	dec [eax + TCP_SOCKET.timer_keepalive]
		209	jnz .check_more3
1159	hidnplayr	210
1519	hidnplayr	211	DEBUGF 1,"socket %x: Keepalive expired\n", eax
1159	hidnplayr	212
1519	hidnplayr	213	;;; TODO: check socket state and handle accordingly
1318	hidnplayr	214
1519	hidnplayr	215	.check_more3:
		216	dec [eax + TCP_SOCKET.timer_timed_wait]
		217	jnz .check_more5
		218
		219	DEBUGF 1,"socket %x: 2MSL timer expired\n", eax
		220
		221	.check_more5:
		222	dec [eax + TCP_SOCKET.timer_persist]
		223	jnz .loop
		224
		225	DEBUGF 1,"socket %x: persist timer expired\n", eax
		226
		227	jmp .loop
		228	.exit:
1529	hidnplayr	229	}
1519	hidnplayr	230
		231
1529	hidnplayr	232
		233
		234	macro TCP_checksum IP1, IP2 {
		235
		236	;-------------
		237	; Pseudoheader
		238
		239	; protocol type
		240	mov edx, IP_PROTO_TCP
		241
		242	; source address
1530	hidnplayr	243	add dl, byte [IP1+1]
		244	adc dh, byte [IP1+0]
		245	adc dl, byte [IP1+3]
		246	adc dh, byte [IP1+2]
1529	hidnplayr	247
		248	; destination address
1530	hidnplayr	249	adc dl, byte [IP2+1]
		250	adc dh, byte [IP2+0]
		251	adc dl, byte [IP2+3]
		252	adc dh, byte [IP2+2]
1529	hidnplayr	253
		254	; size
		255	adc dl, cl
		256	adc dh, ch
		257
		258	;---------------------
		259	; Real header and data
		260
		261	push esi
		262	call checksum_1
		263	call checksum_2
		264	pop esi
		265
		266	} ; returns in dx only
		267
		268
1533	hidnplayr	269	macro TCP_sendseqinit ptr {
1529	hidnplayr	270
1533	hidnplayr	271	push edi ;;;; i dont like this static use of edi
		272	mov edi, [ptr + TCP_SOCKET.ISS]
		273	mov [ptr + TCP_SOCKET.SND_UP], edi
		274	mov [ptr + TCP_SOCKET.SND_MAX], edi
		275	mov [ptr + TCP_SOCKET.SND_NXT], edi
		276	mov [ptr + TCP_SOCKET.SND_UNA], edi
		277	pop edi
		278
		279	}
		280
		281	macro TCP_rcvseqinit ptr {
		282
		283	push edi
		284	mov edi, [ptr + TCP_SOCKET.IRS]
		285	inc edi
		286	mov [ptr + TCP_SOCKET.RCV_NXT], edi
		287	mov [ptr + TCP_SOCKET.RCV_ADV], edi
		288	pop edi
		289
		290	}
		291
		292
		293
1249	hidnplayr	294	;-----------------------------------------------------------------
		295	;
1514	hidnplayr	296	; TCP_input:
1159	hidnplayr	297	;
1514	hidnplayr	298	; IN: [esp] = ptr to buffer
		299	; [esp+4] = buffer size
		300	; ebx = ptr to device struct
		301	; ecx = segment size
		302	; edx = ptr to TCP segment
1196	hidnplayr	303	;
1514	hidnplayr	304	; esi = ipv4 source address
		305	; edi = ipv4 dest address
		306	;
1196	hidnplayr	307	; OUT: /
		308	;
		309	;-----------------------------------------------------------------
1249	hidnplayr	310	align 4
1514	hidnplayr	311	TCP_input:
1159	hidnplayr	312
1529	hidnplayr	313	DEBUGF 1,"TCP_input size=%u\n", ecx
1514	hidnplayr	314	; Offset must be greater than or equal to the size of the standard TCP header (20) and less than or equal to the TCP length.
1254	hidnplayr	315
1514	hidnplayr	316	movzx eax, [edx + TCP_segment.DataOffset]
		317	and eax, 0xf0
1529	hidnplayr	318	shr al, 2
1514	hidnplayr	319
1529	hidnplayr	320	DEBUGF 1,"headersize=%u\n", eax
1514	hidnplayr	321
		322	cmp eax, 20
		323	jl .drop
		324
		325	;-------------------------------
		326	; Now, re-calculate the checksum
		327
1529	hidnplayr	328	push eax ecx edx
		329	pushw [edx + TCP_segment.Checksum]
		330	mov [edx + TCP_segment.Checksum], 0
		331	push esi edi
1514	hidnplayr	332	mov esi, edx
1530	hidnplayr	333	TCP_checksum (esp), (esp+4)
1529	hidnplayr	334	pop esi edi ; yes, swap them (we dont need dest addr)
		335	pop cx ; previous checksum
		336	cmp cx, dx
		337	pop edx ecx esi
1514	hidnplayr	338	jnz .drop
		339
		340	DEBUGF 1,"Checksum is correct\n"
		341
1529	hidnplayr	342	sub ecx, esi ; update packet size
		343	jl .drop
1534	hidnplayr	344	DEBUGF 1,"we got %u bytes of data\n", ecx
1529	hidnplayr	345
1514	hidnplayr	346	;-----------------------------------------------------------------------------------------
		347	; Check if this packet has a timestamp option (We do it here so we can process it quickly)
		348
1529	hidnplayr	349	cmp esi, 20 + 12 ; Timestamp option is 12 bytes
1514	hidnplayr	350	jl .no_timestamp
		351	je .is_ok
		352
1529	hidnplayr	353	cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list
1514	hidnplayr	354	jne .no_timestamp
		355
		356	.is_ok:
		357	test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set
		358	jnz .no_timestamp
		359
		360	cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header
		361	jne .no_timestamp
		362
		363	DEBUGF 1,"timestamp ok\n"
		364
1529	hidnplayr	365	; TODO: Parse the option
1514	hidnplayr	366	; TODO: Set a Bit in the TCP to tell all options are parsed
		367
		368	.no_timestamp:
		369
		370	;-------------------------------------------
		371	; Convert Big-endian values to little endian
		372
		373	ntohld [edx + TCP_segment.SequenceNumber]
		374	ntohld [edx + TCP_segment.AckNumber]
		375
		376	ntohlw [edx + TCP_segment.Window]
		377	ntohlw [edx + TCP_segment.UrgentPointer]
1529	hidnplayr	378	ntohlw [edx + TCP_segment.SourcePort]
		379	ntohlw [edx + TCP_segment.DestinationPort]
1514	hidnplayr	380
		381	;------------------------------------------------------------
		382	; Next thing to do is find the TCB (thus, the socket pointer)
		383
1274	hidnplayr	384	; IP Packet TCP Destination Port = local Port
1514	hidnplayr	385	; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
1318	hidnplayr	386	; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
1159	hidnplayr	387
		388	mov ebx, net_sockets
		389
1249	hidnplayr	390	.socket_loop:
1514	hidnplayr	391	mov ebx, [ebx + SOCKET.NextPtr]
1159	hidnplayr	392	or ebx, ebx
1514	hidnplayr	393	jz .drop_with_reset
1159	hidnplayr	394
1514	hidnplayr	395	cmp [ebx + SOCKET.Type], IP_PROTO_TCP
1249	hidnplayr	396	jne .socket_loop
1159	hidnplayr	397
1514	hidnplayr	398	mov ax, [edx + TCP_segment.DestinationPort]
		399	cmp [ebx + TCP_SOCKET.LocalPort], ax
		400	jne .socket_loop
		401
		402	mov eax, [ebx + IP_SOCKET.RemoteIP]
1529	hidnplayr	403	cmp eax, edi ; sender IP
1249	hidnplayr	404	je @f
		405	test eax, eax
1514	hidnplayr	406	jnz .socket_loop
1249	hidnplayr	407	@@:
1159	hidnplayr	408
1514	hidnplayr	409	mov ax, [ebx + TCP_SOCKET.RemotePort]
		410	cmp [edx + TCP_segment.SourcePort] , ax
1274	hidnplayr	411	je .found_socket
1249	hidnplayr	412	test ax, ax
1254	hidnplayr	413	jnz .socket_loop
1274	hidnplayr	414	.found_socket:
1529	hidnplayr	415	DEBUGF 1,"Socket ptr: %x\n", ebx
1254	hidnplayr	416
1514	hidnplayr	417	; ebx now contains the pointer to the socket
1257	hidnplayr	418
1514	hidnplayr	419	;----------------------------
		420	; Check if socket isnt closed
		421
1529	hidnplayr	422	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED
1514	hidnplayr	423	je .drop
		424
		425	;----------------
		426	; Lock the socket
		427
1529	hidnplayr	428	;; add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
		429	;; call wait_mutex
		430	;; sub ebx, SOCKET.lock
1159	hidnplayr	431
1529	hidnplayr	432	DEBUGF 1,"Socket locked\n"
1159	hidnplayr	433
1529	hidnplayr	434	;----------------------------------------------------------------------------------------
		435	; unscale the window into a 32 bit value (notice that SND_SCALE must be initialised to 0)
		436
1514	hidnplayr	437	movzx eax, [edx + TCP_segment.Window]
1534	hidnplayr	438	push ecx
1529	hidnplayr	439	mov cl, [ebx + TCP_SOCKET.SND_SCALE]
1514	hidnplayr	440	shl eax, cl
1534	hidnplayr	441	pop ecx
1514	hidnplayr	442
1529	hidnplayr	443	;;;; do something with eax
1514	hidnplayr	444
		445	;-----------------------------------
		446	; Is this socket a listening socket?
		447
1533	hidnplayr	448	test [ebx + SOCKET.options], SO_ACCEPTCON
1529	hidnplayr	449	; jnz .listening_socket ;;;;; TODO
1514	hidnplayr	450
1529	hidnplayr	451	;-------------------------------------
		452	; Reset idle timer and keepalive timer
1514	hidnplayr	453
1529	hidnplayr	454	mov [ebx + TCP_SOCKET.t_idle], 0
		455	mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1514	hidnplayr	456
1529	hidnplayr	457	;--------------------
		458	; Process TCP options
1514	hidnplayr	459
1529	hidnplayr	460	cmp esi, 20 ; esi is headersize
		461	je .no_options
1514	hidnplayr	462
1529	hidnplayr	463	DEBUGF 1,"Segment has options\n"
1514	hidnplayr	464
1530	hidnplayr	465	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
1529	hidnplayr	466	jz .no_options
1514	hidnplayr	467
1529	hidnplayr	468	lea edi, [edx + TCP_segment.Data]
		469	lea eax, [edx + esi]
1514	hidnplayr	470
1529	hidnplayr	471	.opt_loop:
		472	cmp edi, eax
		473	jge .no_options
1514	hidnplayr	474
1529	hidnplayr	475	cmp byte [edi], TCP_OPT_EOL ; end of option list?
		476	jz .no_options
1514	hidnplayr	477
1529	hidnplayr	478	cmp byte [edi], TCP_OPT_NOP ; nop ?
		479	jz .opt_nop
1514	hidnplayr	480
1529	hidnplayr	481	cmp byte [edi], TCP_OPT_MAXSEG
		482	je .opt_maxseg
1514	hidnplayr	483
1529	hidnplayr	484	cmp byte [edi], TCP_OPT_WINDOW
		485	je .opt_window
1514	hidnplayr	486
1529	hidnplayr	487	cmp byte [edi], TCP_OPT_TIMESTAMP
		488	je .opt_timestamp
1514	hidnplayr	489
1529	hidnplayr	490	jmp .no_options ; If we reach here, some unknown options were received, skip them all!
1514	hidnplayr	491
1529	hidnplayr	492	.opt_nop:
		493	inc edi
		494	jmp .opt_loop
1514	hidnplayr	495
1529	hidnplayr	496	.opt_maxseg:
		497	cmp byte [edi+1], 4
		498	jne .no_options ; error occured, ignore all options!
1514	hidnplayr	499
1529	hidnplayr	500	test [edx + TCP_segment.Flags], TH_SYN
		501	jz @f
		502
1530	hidnplayr	503	movzx eax, word[edi+2]
		504	rol ax, 8
1533	hidnplayr	505	DEBUGF 1,"Maxseg: %u\n", ax
1529	hidnplayr	506
1530	hidnplayr	507	mov [ebx + TCP_SOCKET.t_maxseg], eax
		508
1529	hidnplayr	509	@@:
		510	add edi, 4
		511	jmp .opt_loop
		512
		513
		514	.opt_window:
		515	cmp byte [edi+1], 3
		516	jne .no_options
		517
		518	test [edx + TCP_segment.Flags], TH_SYN
		519	jz @f
		520
1533	hidnplayr	521	DEBUGF 1,"Got window option\n"
1529	hidnplayr	522
		523	;;;;;
		524	@@:
		525	add edi, 3
		526	jmp .opt_loop
		527
		528
		529	.opt_timestamp:
		530	cmp byte [edi+1], 10
		531	jne .no_options
		532
1533	hidnplayr	533	DEBUGF 1,"Got timestamp option\n"
1529	hidnplayr	534
		535	;;;;;
		536
		537	add edi, 10
		538	jmp .opt_loop
		539
		540	.no_options:
		541
1514	hidnplayr	542	;-----------------------------------------------------------------------
		543	; Time to do some header prediction (Original Principle by Van Jacobson)
		544
		545	; There are two common cases for an uni-directional data transfer.
		546	;
		547	; General rule: the packets has no control flags, is in-sequence,
		548	; window width didnt change and we're not retransmitting.
		549	;
		550	; Second rules:
		551	; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
		552	; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
		553	;
		554	; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
		555	; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
		556
1529	hidnplayr	557	cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
1514	hidnplayr	558	jnz .not_uni_xfer
		559
1533	hidnplayr	560	DEBUGF 1,"1\n"
		561
1529	hidnplayr	562	test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
1514	hidnplayr	563	jnz .not_uni_xfer
		564
1533	hidnplayr	565	DEBUGF 1,"2\n"
		566
1529	hidnplayr	567	test [edx + TCP_segment.Flags], TH_ACK
1514	hidnplayr	568	jz .not_uni_xfer
		569
1533	hidnplayr	570	DEBUGF 1,"3\n"
		571
1514	hidnplayr	572	mov eax, [edx + TCP_segment.SequenceNumber]
		573	cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
		574	jne .not_uni_xfer
		575
1533	hidnplayr	576	DEBUGF 1,"4\n"
1514	hidnplayr	577
1533	hidnplayr	578	;; movzx eax, [edx + TCP_segment.Window] ;;;;; (should use pre-calculated value isntead: todo: figure out where to store it)
		579	;; cmp eax, [ebx + TCP_SOCKET.SND_WND]
		580	;; jne .not_uni_xfer
		581
		582	DEBUGF 1,"5\n"
		583
1514	hidnplayr	584	mov eax, [ebx + TCP_SOCKET.SND_NXT]
		585	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		586	jne .not_uni_xfer
		587
1534	hidnplayr	588	DEBUGF 1,"6\n"
		589
1514	hidnplayr	590	;---------------------------------------
		591	; check if we are sender in the uni-xfer
		592
		593	; If the following 4 conditions are all true, this segment is a pure ACK.
		594	;
1529	hidnplayr	595	; - The segment contains no data.
		596	test ecx, ecx
1514	hidnplayr	597	jnz .not_sender
1274	hidnplayr	598
1534	hidnplayr	599	DEBUGF 1,"7\n"
		600
1529	hidnplayr	601	; - The congestion window is greater than or equal to the current send window.
1514	hidnplayr	602	; This test is true only if the window is fully open, that is, the connection is not in the middle of slow start or congestion avoidance.
		603	mov eax, [ebx + TCP_SOCKET.SND_CWND]
		604	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		605	jl .not_uni_xfer
1318	hidnplayr	606
1534	hidnplayr	607	DEBUGF 1,"8\n"
		608
1529	hidnplayr	609	; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
1534	hidnplayr	610	mov eax, [edx + TCP_segment.AckNumber]
		611	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
1529	hidnplayr	612	jg .not_uni_xfer
		613
1534	hidnplayr	614	DEBUGF 1,"9\n"
		615
1529	hidnplayr	616	; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
1534	hidnplayr	617	sub eax, [ebx + TCP_SOCKET.SND_UNA]
1529	hidnplayr	618	jle .not_uni_xfer
		619
1514	hidnplayr	620	DEBUGF 1,"Header prediction: we are sender\n"
1274	hidnplayr	621
1514	hidnplayr	622	;---------------------------------
		623	; Packet is a pure ACK, process it
1274	hidnplayr	624
1514	hidnplayr	625	; Update RTT estimators
1159	hidnplayr	626
1514	hidnplayr	627	; Delete acknowledged bytes from send buffer
1529	hidnplayr	628	; notice how ecx already holds number of bytes ack-ed
1254	hidnplayr	629
1533	hidnplayr	630	lea eax, [ebx + STREAM_SOCKET.snd]
1529	hidnplayr	631	call SOCKET_ring_free
		632
1514	hidnplayr	633	; Stop retransmit timer
1519	hidnplayr	634	mov [ebx + TCP_SOCKET.timer_ack], 0
1159	hidnplayr	635
1514	hidnplayr	636	; Awaken waiting processes
1519	hidnplayr	637	mov eax, ebx
		638	call SOCKET_notify_owner
1318	hidnplayr	639
1514	hidnplayr	640	; Generate more output
1519	hidnplayr	641	call TCP_output
1254	hidnplayr	642
1514	hidnplayr	643	jmp .drop
1159	hidnplayr	644
1514	hidnplayr	645	;-------------------------------------------------
		646	; maybe we are the receiver in the uni-xfer then..
		647
		648	.not_sender:
1529	hidnplayr	649	; - The amount of data in the segment is greater than 0 (data count is in ecx)
1514	hidnplayr	650
1534	hidnplayr	651	DEBUGF 1,"10\n"
		652
1529	hidnplayr	653	; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
1514	hidnplayr	654	mov eax, [edx + TCP_segment.AckNumber]
		655	cmp eax, [ebx + TCP_SOCKET.SND_UNA]
		656	jne .not_uni_xfer
		657
1529	hidnplayr	658	; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
1514	hidnplayr	659
		660	jnz .not_uni_xfer
		661
		662	;-------------------------------------
		663	; Complete processing of received data
		664
		665	DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
		666
1529	hidnplayr	667	add esi, edx
1533	hidnplayr	668	lea eax, [ebx + STREAM_SOCKET.rcv]
		669	call SOCKET_ring_write ; Add the data to the socket buffer
1514	hidnplayr	670
1533	hidnplayr	671	mov eax, ebx
		672	call SOCKET_notify_owner
		673
1529	hidnplayr	674	add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
		675	or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
1514	hidnplayr	676
		677	jmp .drop
		678
		679	;----------------------------------------------------
1529	hidnplayr	680	; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
1514	hidnplayr	681
		682	.not_uni_xfer:
		683
1533	hidnplayr	684	DEBUGF 1,"Header prediction failed\n" ; time to do it the "slow" way :)
1514	hidnplayr	685
		686	;------------------------------
		687	; Calculate receive window size
		688
		689	;;;;
		690
1529	hidnplayr	691	cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN
1514	hidnplayr	692	je .LISTEN
		693
1529	hidnplayr	694	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
1514	hidnplayr	695	je .SYN_SENT
		696
		697	;--------------------------------------------
		698	; Protection Against Wrapped Sequence Numbers
		699
1533	hidnplayr	700	; First, check if timestamp is present
1514	hidnplayr	701
		702	;;;; TODO
		703
		704	; Then, check if at least some bytes of data are within window
		705
		706	;;;; TODO
		707
		708	jmp .trim_then_step6
		709
1529	hidnplayr	710	;-------------
		711	; Passive Open
		712
1249	hidnplayr	713	align 4
1514	hidnplayr	714	.LISTEN:
1196	hidnplayr	715
1514	hidnplayr	716	DEBUGF 1,"TCP state: listen\n"
1159	hidnplayr	717
1514	hidnplayr	718	test [edx + TCP_segment.Flags], TH_RST
		719	jnz .drop
1159	hidnplayr	720
1514	hidnplayr	721	test [edx + TCP_segment.Flags], TH_ACK
		722	jnz .drop_with_reset
1159	hidnplayr	723
1514	hidnplayr	724	test [edx + TCP_segment.Flags], TH_SYN
		725	jz .drop
1159	hidnplayr	726
1533	hidnplayr	727	cmp esi, 0xffffff ; destination ip = 255.255.255.255 ?
		728	jz .drop
		729
1514	hidnplayr	730	; TODO: check if it's a broadcast or multicast, and drop if so
1159	hidnplayr	731
1529	hidnplayr	732	call SOCKET_fork
		733	jz .drop ; if we could not open a new connection, drop segment (;;;; should we send RST too?)
1514	hidnplayr	734
1529	hidnplayr	735	;-----------------------
		736	; Fill in some variables
1514	hidnplayr	737
1529	hidnplayr	738	add [TCP_sequence_num], 64000
1514	hidnplayr	739
1529	hidnplayr	740	push [edx + TCP_segment.SourcePort]
		741	pop [eax + TCP_SOCKET.RemotePort]
1514	hidnplayr	742
1529	hidnplayr	743	push [edx + TCP_segment.SequenceNumber]
		744	pop [eax + TCP_SOCKET.IRS]
1159	hidnplayr	745
1529	hidnplayr	746	push [eax + TCP_SOCKET.ISS]
		747	pop [eax + TCP_SOCKET.SND_NXT]
1159	hidnplayr	748
1529	hidnplayr	749	mov [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		750	mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
		751	mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
1159	hidnplayr	752
1529	hidnplayr	753	mov ebx, eax
1514	hidnplayr	754	jmp .trim_then_step6
1159	hidnplayr	755
1254	hidnplayr	756
1529	hidnplayr	757	;------------
		758	; Active Open
1159	hidnplayr	759
1514	hidnplayr	760	align 4
		761	.SYN_SENT:
1281	hidnplayr	762
1514	hidnplayr	763	DEBUGF 1,"TCP state: syn_sent\n"
1159	hidnplayr	764
1514	hidnplayr	765	test [edx + TCP_segment.Flags], TH_ACK
		766	jz @f
1281	hidnplayr	767
1514	hidnplayr	768	mov eax, [edx + TCP_segment.AckNumber]
		769	cmp eax, [ebx + TCP_SOCKET.ISS]
		770	jle .drop_with_reset
1281	hidnplayr	771
1529	hidnplayr	772	; mov eax, [edx + TCP_segment.AckNumber]
1533	hidnplayr	773	cmp eax, [ebx + TCP_SOCKET.SND_MAX]
		774	jg .drop_with_reset
1514	hidnplayr	775	@@:
1281	hidnplayr	776
1514	hidnplayr	777	test [edx + TCP_segment.Flags], TH_RST
		778	jz @f
1281	hidnplayr	779
1514	hidnplayr	780	test [edx + TCP_segment.Flags], TH_ACK
		781	jz .drop
1281	hidnplayr	782
1514	hidnplayr	783	;tp = tcp_drop(tp, ECONNREFUSED)
1159	hidnplayr	784
1514	hidnplayr	785	jmp .drop
		786	@@:
1159	hidnplayr	787
1514	hidnplayr	788	test [edx + TCP_segment.Flags], TH_SYN
		789	jz .drop
1318	hidnplayr	790
1529	hidnplayr	791	; at this point, segment seems to be valid
		792
1514	hidnplayr	793	test [edx + TCP_segment.Flags], TH_ACK
1529	hidnplayr	794	jz .no_syn_ack
1514	hidnplayr	795
1529	hidnplayr	796	; now, process received SYN in response to an active open
		797
1514	hidnplayr	798	mov eax, [edx + TCP_segment.AckNumber]
		799	mov [ebx + TCP_SOCKET.SND_UNA], eax
		800	cmp eax, [ebx + TCP_SOCKET.SND_NXT]
		801	jle @f
		802	mov [ebx + TCP_SOCKET.SND_NXT], eax
1529	hidnplayr	803	@@:
1514	hidnplayr	804
1529	hidnplayr	805	.no_syn_ack:
1514	hidnplayr	806
1529	hidnplayr	807	mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
1514	hidnplayr	808
1529	hidnplayr	809	push [edx + TCP_segment.SequenceNumber]
		810	pop [ebx + TCP_SOCKET.IRS]
		811
1533	hidnplayr	812	TCP_rcvseqinit ebx
1529	hidnplayr	813
		814	mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
		815
		816	mov eax, [ebx + TCP_SOCKET.SND_UNA]
		817	cmp eax, [ebx + TCP_SOCKET.ISS]
		818	jle .simultaneous_open
		819
		820	test [edx + TCP_segment.Flags], TH_ACK
		821	jz .simultaneous_open
		822
		823	DEBUGF 1,"TCP: active open\n"
		824
		825	; TODO: update stats
1533	hidnplayr	826	; TODO: set general socket state to connected
1514	hidnplayr	827
		828	mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
		829
		830	; TODO: check if we should scale the connection (567-572)
		831	; TODO: update RTT estimators
		832
1529	hidnplayr	833	jmp .trimthenstep6
1514	hidnplayr	834
1529	hidnplayr	835	.simultaneous_open:
1514	hidnplayr	836
1529	hidnplayr	837	DEBUGF 1,"TCP: simultaneous open\n"
1514	hidnplayr	838	; We have received a syn but no ACK, so we are having a simultaneous open..
		839	mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		840
		841	;-------------------------------------
		842	; Common processing for receipt of SYN
		843
		844	.trimthenstep6:
		845
		846	inc [edx + TCP_segment.SequenceNumber]
		847
		848	cmp cx, [ebx + TCP_SOCKET.RCV_WND]
		849	jle @f
		850
		851	movzx eax, cx
		852	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		853	; TODO: 592
		854	mov cx, [ebx + TCP_SOCKET.RCV_WND]
		855	; TODO...
		856	@@:
		857	;;;;;
1529	hidnplayr	858	jmp .step6
1514	hidnplayr	859
		860
		861
		862
		863
1529	hidnplayr	864	.trim_then_step6:
1159	hidnplayr	865
1514	hidnplayr	866	;----------------------------
		867	; trim any data not in window
1159	hidnplayr	868
1533	hidnplayr	869	DEBUGF 1,"Trimming window\n"
		870
1514	hidnplayr	871	mov eax, [ebx + TCP_SOCKET.RCV_NXT]
		872	sub eax, [edx + TCP_segment.SequenceNumber]
1318	hidnplayr	873
1514	hidnplayr	874	test eax, eax
1533	hidnplayr	875	jz .no_duplicate
1274	hidnplayr	876
1514	hidnplayr	877	test [edx + TCP_segment.Flags], TH_SYN
		878	jz .no_drop
		879
		880	and [edx + TCP_segment.Flags], not (TH_SYN)
		881	inc [edx + TCP_segment.SequenceNumber]
		882
		883	cmp [edx + TCP_segment.UrgentPointer], 1
		884	jl @f
		885
		886	dec [edx + TCP_segment.UrgentPointer]
		887
		888	jmp .no_drop
		889	@@:
		890
		891	and [edx + TCP_segment.Flags], not (TH_URG)
		892	dec eax
1533	hidnplayr	893	jz .no_duplicate
1514	hidnplayr	894	.no_drop:
		895
1533	hidnplayr	896	DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx
1529	hidnplayr	897
1514	hidnplayr	898	; eax holds number of bytes to drop
		899
		900	;----------------------------------
		901	; Check for entire duplicate packet
		902
		903	cmp eax, ecx
		904	jge .duplicate
		905
		906	;;; TODO: figure 28.30
		907
		908	;------------------------
		909	; Check for duplicate FIN
		910
		911	test [edx + TCP_segment.Flags], TH_FIN
		912	jz @f
		913	inc ecx
		914	cmp eax, ecx
		915	dec ecx
		916	jne @f
		917
		918	mov eax, ecx
		919	and [edx + TCP_segment.Flags], not TH_FIN
1529	hidnplayr	920	or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	921	jmp .no_duplicate
		922	@@:
		923
		924	; Handle the case when a bound socket connects to itself
		925	; Allow packets with a SYN and an ACKto continue with the processing
		926
		927	;-------------------------------------
		928	; Generate duplicate ACK if nescessary
		929
		930	; This code also handles simultaneous half-open or self-connects
		931
		932	test eax, eax
		933	jnz .drop_after_ack
		934
		935	cmp [edx + TCP_segment.Flags], TH_ACK
		936	jz .drop_after_ack
		937
		938	.duplicate:
		939
1533	hidnplayr	940	DEBUGF 1,"Duplicate received\n"
1529	hidnplayr	941
1514	hidnplayr	942	;----------------------------------------
		943	; Update statistics for duplicate packets
		944
		945	;;; TODO
		946
1529	hidnplayr	947	jmp .drop ;;; DROP the packet ??
1514	hidnplayr	948
		949	.no_duplicate:
		950
		951	;-----------------------------------------------
		952	; Remove duplicate data and update urgent offset
		953
		954	add [edx + TCP_segment.SequenceNumber], eax
		955
		956	;;; TODO
		957
		958	sub [edx + TCP_segment.UrgentPointer], ax
		959	jg @f
		960
		961	and [edx + TCP_segment.Flags], not (TH_URG)
		962	mov [edx + TCP_segment.UrgentPointer], 0
		963	@@:
		964
		965	;--------------------------------------------------
		966	; Handle data that arrives after process terminates
		967
		968	cmp [ebx + SOCKET.PID], 0
1533	hidnplayr	969	jg @f
1514	hidnplayr	970
		971	cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
		972	jle @f
		973
		974	test ecx, ecx
		975	jz @f
		976
		977	;;; Close the socket
		978	;;; update stats
		979
		980	jmp .drop_with_reset
		981	@@:
		982
		983	;----------------------------------------
		984	; Remove data beyond right edge of window
		985
		986	mov eax, [edx + TCP_segment.SequenceNumber]
		987	add eax, ecx
		988	sub eax, [ebx + TCP_SOCKET.RCV_NXT]
		989	sub ax, [ebx + TCP_SOCKET.RCV_WND]
		990
		991	; eax now holds the number of bytes to drop
		992
		993	jle .no_excess_data
		994
		995	;;; TODO: update stats
		996
		997	cmp eax, ecx
		998	jl .dont_drop_all
		999
		1000	;;; TODO 700-736
		1001
		1002	.dont_drop_all:
		1003
		1004	.no_excess_data:
		1005
		1006	;-----------------
		1007	; Record timestamp
		1008
		1009	;;; TODO 737-746
		1010
		1011	;------------------
		1012	; Process RST flags
		1013
		1014	test [edx + TCP_segment.Flags], TH_RST
		1015	jz .rst_skip
		1016
1529	hidnplayr	1017	DEBUGF 1,"Got an RST flag"
		1018
1514	hidnplayr	1019	mov eax, [ebx + TCP_SOCKET.t_state]
		1020	shl eax, 2
		1021	jmp dword [eax + .rst_sw_list]
		1022
		1023	.rst_sw_list:
		1024	dd .rst_skip ;TCB_CLOSED
		1025	dd .rst_skip ;TCB_LISTEN
		1026	dd .rst_skip ;TCB_SYN_SENT
		1027	dd .econnrefused ;TCB_SYN_RECEIVED
		1028	dd .econnreset ;TCB_ESTABLISHED
		1029	dd .econnreset ;TCB_CLOSE_WAIT
		1030	dd .econnreset ;TCB_FIN_WAIT_1
		1031	dd .rst_close ;TCB_CLOSING
		1032	dd .rst_close ;TCB_LAST_ACK
		1033	dd .econnreset ;TCB_FIN_WAIT_2
		1034	dd .rst_close ;TCB_TIMED_WAIT
		1035
		1036	.econnrefused:
		1037
1529	hidnplayr	1038	DEBUGF 1,"Connection refused"
		1039
1514	hidnplayr	1040	;;; TODO: debug info
		1041
		1042	jmp .close
		1043
		1044	.econnreset:
		1045
1529	hidnplayr	1046	DEBUGF 1,"Connection reset"
		1047
1514	hidnplayr	1048	;;; TODO: debug info
1529	hidnplayr	1049	.close:
1514	hidnplayr	1050
1529	hidnplayr	1051	DEBUGF 1,"Closing connection"
		1052
1514	hidnplayr	1053	;;; update stats
		1054
		1055	.rst_close:
		1056
1534	hidnplayr	1057	DEBUGF 1,"Closing with reset\n"
1529	hidnplayr	1058
1514	hidnplayr	1059	;;; Close the socket
		1060	jmp .drop
		1061
		1062	.rst_skip:
		1063
		1064	;--------------------------------------
		1065	; handle SYN-full and ACK-less segments
		1066
		1067	test [edx + TCP_segment.Flags], TH_SYN
		1068	jz @f
		1069
		1070	;;; tcp_drop ( ECONNRESET)
		1071	jmp .drop_with_reset
		1072
		1073	test [edx + TCP_segment.Flags], TH_ACK
		1074	jz .drop
1534	hidnplayr	1075	@@:
1514	hidnplayr	1076	;----------------
		1077	; Process the ACK
		1078
		1079	cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1080	jg .ack_dup
		1081	jl .ack_nodup
		1082
1534	hidnplayr	1083	DEBUGF 1,"TCP state = syn received\n"
1533	hidnplayr	1084
1514	hidnplayr	1085	;;;;;
		1086
		1087	.ack_dup:
		1088
1534	hidnplayr	1089	DEBUGF 1,"Duplicate ACK\n"
1533	hidnplayr	1090
1514	hidnplayr	1091	;;;;
		1092
		1093	.ack_nodup:
		1094
		1095	;;;; 887
		1096
1534	hidnplayr	1097	DEBUGF 1,"New ACK\n"
1533	hidnplayr	1098
1514	hidnplayr	1099	;-------------------------------------------------
1519	hidnplayr	1100	; If the congestion window was inflated to account
1514	hidnplayr	1101	; for the other side's cached packets, retrace it
		1102
		1103	;;;; 888 - 902
		1104
		1105
		1106	;------------------------------------------
		1107	; RTT measurements and retransmission timer
		1108
		1109	;;;;; 903 - 926
		1110
1519	hidnplayr	1111	mov [ebx + TCP_SOCKET.timer_retransmission], 0
1514	hidnplayr	1112
1519	hidnplayr	1113	mov eax, [ebx + TCP_SOCKET.SND_MAX]
		1114	cmp eax, [edx + TCP_segment.AckNumber]
		1115	je .all_outstanding
		1116	mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value
		1117	.all_outstanding:
		1118
1514	hidnplayr	1119	;-------------------------------------------
		1120	; Open congestion window in response to ACKs
		1121
		1122	;;;;
		1123
		1124
		1125	;------------------------------------------
		1126	; Remove acknowledged data from send buffer
		1127
1534	hidnplayr	1128	push ecx
		1129	mov ecx, [edx + TCP_segment.AckNumber] ;;;
		1130	sub ecx, [ebx + TCP_SOCKET.SND_UNA] ;;;
1533	hidnplayr	1131	lea eax, [ebx + STREAM_SOCKET.snd]
		1132	call SOCKET_ring_free ;;;; 943 - 956
1534	hidnplayr	1133	pop ecx
1514	hidnplayr	1134
		1135	;---------------------------------------
		1136	; Wake up process waiting on send buffer
		1137
1529	hidnplayr	1138	mov eax, ebx
		1139	call SOCKET_notify_owner
1514	hidnplayr	1140
		1141	mov eax, [ebx + TCP_SOCKET.t_state]
		1142	shl eax, 2
		1143	jmp dword [eax + .ACK_sw_list]
		1144
		1145	.ACK_sw_list:
		1146	dd .step6 ;TCB_CLOSED
		1147	dd .step6 ;TCB_LISTEN
		1148	dd .step6 ;TCB_SYN_SENT
		1149	dd .step6 ;TCB_SYN_RECEIVED
		1150	dd .step6 ;TCB_ESTABLISHED
		1151	dd .step6 ;TCB_CLOSE_WAIT
		1152	dd ._963 ;TCB_FIN_WAIT_1
		1153	dd ._958 ;TCB_CLOSING
		1154	dd ._999 ;TCB_LAST_ACK
		1155	dd .step6 ;TCB_FIN_WAIT_2
		1156	dd ._1010 ;TCB_TIMED_WAIT
		1157
		1158
		1159	._963:
		1160
		1161
		1162	jmp .step6
		1163
		1164
		1165	._958:
		1166
		1167	jmp .step6
		1168
		1169	._999:
		1170
		1171	jmp .step6
		1172
		1173
		1174	._1010:
		1175
		1176	jmp .step6
		1177
		1178
		1179
		1180	align 4
		1181	.step6:
		1182
		1183	DEBUGF 1,"step 6\n"
		1184
		1185	;--------------------------
		1186	; update window information
		1187
		1188	test [edx + TCP_segment.Flags], TH_ACK
		1189	jz .no_window_update
		1190
		1191	mov eax, [ebx + TCP_SOCKET.SND_WL1]
		1192	cmp eax, [edx + TCP_segment.SequenceNumber]
		1193
		1194	;;;; 1021
		1195
		1196	;----------------------------------
		1197	; Keep track of pure window updates
		1198
		1199	test ecx, ecx
		1200	jz @f
		1201
		1202	mov eax, [ebx + TCP_SOCKET.SND_WL2]
		1203	cmp eax, [edx + TCP_segment.AckNumber]
		1204	jne @f
		1205
		1206	;; mov eax, tiwin
		1207	cmp eax, [ebx + TCP_SOCKET.SND_WND]
		1208	jle @f
		1209
		1210	;;; update stats
		1211
		1212	@@:
		1213
		1214	;; mov eax, incoming window
		1215	cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
		1216	jle @f
		1217	mov [ebx + TCP_SOCKET.max_sndwnd], eax
		1218	@@:
		1219	mov [ebx + TCP_SOCKET.SND_WND], eax
		1220
		1221	mov eax, [edx + TCP_segment.SequenceNumber]
		1222	mov [ebx + TCP_SOCKET.SND_WL1], eax
		1223
		1224	mov eax, [edx + TCP_segment.AckNumber]
		1225	mov [ebx + TCP_SOCKET.SND_WL2], eax
		1226
		1227	;;; needoutput = 1
		1228
		1229	.no_window_update:
		1230
		1231	;-----------------
		1232	; process URG flag
		1233
		1234	test [edx + TCP_segment.Flags], TH_URG
		1235	jz .not_urgent
		1236
		1237	cmp [edx + TCP_segment.UrgentPointer], 0
		1238	jz .not_urgent
		1239
		1240	cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
		1241	je .not_urgent
		1242
		1243	; Ignore bogus urgent offsets
		1244
		1245	;;; 1040-1050
		1246
		1247	movzx eax, [edx + TCP_segment.UrgentPointer]
1533	hidnplayr	1248	add eax, [ebx + STREAM_SOCKET.rcv + RING_BUFFER.size]
1514	hidnplayr	1249	cmp eax, SOCKET_MAXDATA
		1250	jle .not_urgent
		1251
		1252	mov [edx + TCP_segment.UrgentPointer], 0
		1253	and [edx + TCP_segment.Flags], not (TH_URG)
		1254	jmp .do_data
		1255
		1256	.not_urgent:
		1257
		1258	;--------------------------------------
		1259	; processing of received urgent pointer
		1260
1529	hidnplayr	1261	;;; TODO (1051-1093)
1514	hidnplayr	1262
1529	hidnplayr	1263	;--------------------------------
		1264	; process the data in the segment
1514	hidnplayr	1265
1529	hidnplayr	1266	.do_data:
1514	hidnplayr	1267
1534	hidnplayr	1268	DEBUGF 1,"TCP: do data (%u)\n", ecx
1514	hidnplayr	1269
		1270	test [edx + TCP_segment.Flags], TH_FIN
1529	hidnplayr	1271	jnz .process_fin
1514	hidnplayr	1272
1533	hidnplayr	1273	cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
1514	hidnplayr	1274	jge .dont_do_data
		1275
1533	hidnplayr	1276	test ecx, ecx
		1277	jz .final_processing
		1278
1514	hidnplayr	1279	DEBUGF 1,"Processing data in segment\n"
		1280
1533	hidnplayr	1281	;; TODO: check if data is in sequence !
1514	hidnplayr	1282
1533	hidnplayr	1283	movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ?
		1284	and eax, 0xf0
		1285	shr al, 2
		1286
		1287	lea esi, [edx + eax]
		1288
		1289	or [ebx + TCP_SOCKET.t_flags], TF_DELACK
		1290	add [ebx + TCP_SOCKET.RCV_NXT], ecx ;;; right ?
		1291
		1292	lea eax, [ebx + STREAM_SOCKET.rcv]
		1293	call SOCKET_ring_write
		1294
		1295	mov eax, ebx
		1296	call SOCKET_notify_owner
		1297
1514	hidnplayr	1298	jmp .final_processing
		1299
		1300
		1301	.dont_do_data:
		1302
		1303	;---------------
		1304	; FIN processing
		1305
		1306	.process_fin:
		1307
		1308	DEBUGF 1,"Processing FIN\n"
		1309
		1310	mov eax, [ebx + TCP_SOCKET.t_state]
		1311	shl eax, 2
		1312	jmp dword [eax + .FIN_sw_list]
		1313
		1314	.FIN_sw_list:
		1315	dd .no_fin ;TCB_CLOSED
		1316	dd .no_fin ;TCB_LISTEN
		1317	dd .no_fin ;TCB_SYN_SENT
1533	hidnplayr	1318	dd .fin_syn_est ;TCB_SYN_RECEIVED
		1319	dd .fin_syn_est ;TCB_ESTABLISHED
1514	hidnplayr	1320	dd .no_fin ;TCB_CLOSE_WAIT
1533	hidnplayr	1321	dd .fin_wait1 ;TCB_FIN_WAIT_1
1514	hidnplayr	1322	dd .no_fin ;TCB_CLOSING
		1323	dd .no_fin ;TCB_LAST_ACK
1533	hidnplayr	1324	dd .fin_wait2 ;TCB_FIN_WAIT_2
		1325	dd .fin_timed ;TCB_TIMED_WAIT
1514	hidnplayr	1326
		1327
		1328
1533	hidnplayr	1329	.fin_syn_est:
1514	hidnplayr	1330
1533	hidnplayr	1331	jmp .final_processing
1514	hidnplayr	1332
1533	hidnplayr	1333	.fin_wait1:
1514	hidnplayr	1334
1533	hidnplayr	1335	jmp .final_processing
1514	hidnplayr	1336
1533	hidnplayr	1337	.fin_wait2:
1514	hidnplayr	1338
1533	hidnplayr	1339	jmp .final_processing
		1340
		1341	.fin_timed:
		1342
		1343	jmp .final_processing
		1344
1514	hidnplayr	1345	.no_fin:
		1346
		1347	;-----------------
		1348	; Final processing
		1349
		1350	.final_processing:
		1351
		1352	DEBUGF 1,"Final processing\n"
		1353
1533	hidnplayr	1354	mov [ebx + SOCKET.lock], 0
		1355
1514	hidnplayr	1356	;;; if debug enabled, output packet
		1357
		1358	;test ;;;needoutput = 1
		1359	;jnz .outputnow
		1360
		1361	test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1529	hidnplayr	1362	jnz .ack_now
1514	hidnplayr	1363
1529	hidnplayr	1364	call kernel_free
		1365	add esp, 4
		1366	ret
		1367
		1368	.ack_now:
		1369
		1370	DEBUGF 1,"ACK now!\n"
		1371
		1372	push ebx
		1373	mov eax, ebx
1514	hidnplayr	1374	call TCP_output
1529	hidnplayr	1375	pop ebx
1514	hidnplayr	1376
1274	hidnplayr	1377	call kernel_free
1529	hidnplayr	1378	add esp, 4
		1379	ret
1274	hidnplayr	1380
1514	hidnplayr	1381	;------------------------------------------
		1382	; Generate an ACK, droping incoming segment
1274	hidnplayr	1383
1514	hidnplayr	1384	align 4
		1385	.drop_after_ack:
1274	hidnplayr	1386
1514	hidnplayr	1387	DEBUGF 1,"Drop after ACK\n"
1274	hidnplayr	1388
1514	hidnplayr	1389	test [edx + TCP_segment.Flags], TH_RST
		1390	jnz .drop
1274	hidnplayr	1391
1514	hidnplayr	1392	and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
1274	hidnplayr	1393
1529	hidnplayr	1394	push ebx
		1395	mov eax, ebx
1514	hidnplayr	1396	call TCP_output
1529	hidnplayr	1397	pop ebx
1318	hidnplayr	1398
1514	hidnplayr	1399	call kernel_free
1529	hidnplayr	1400	add esp, 4
		1401	ret
1274	hidnplayr	1402
1514	hidnplayr	1403
		1404	;-------------------------------------------
		1405	; Generate an RST, dropping incoming segment
		1406
		1407	align 4
		1408	.drop_with_reset:
		1409
		1410	DEBUGF 1,"Drop with reset\n"
		1411
		1412	test [edx + TCP_segment.Flags], TH_RST
		1413	jnz .drop
		1414
		1415	;;; if its a multicast/broadcast, also drop
		1416
		1417	test [edx + TCP_segment.Flags], TH_ACK
		1418	jnz .respond_ack
		1419
		1420	test [edx + TCP_segment.Flags], TH_SYN
		1421	jnz .respond_syn
		1422
		1423	call kernel_free
1529	hidnplayr	1424	add esp, 4
		1425	ret
1514	hidnplayr	1426
		1427	.respond_ack:
		1428
1533	hidnplayr	1429	mov dl, TH_RST
1514	hidnplayr	1430
1533	hidnplayr	1431	push ebx
1529	hidnplayr	1432	call TCP_respond_segment
1533	hidnplayr	1433	pop ebx
1514	hidnplayr	1434
		1435	jmp .destroy_new_socket
		1436
		1437
		1438	.respond_syn:
		1439
1533	hidnplayr	1440	mov dl, TH_RST + TH_ACK
1514	hidnplayr	1441
1533	hidnplayr	1442	push ebx
		1443	call TCP_respond_socket
		1444	pop ebx
1514	hidnplayr	1445
		1446	jmp .destroy_new_socket
		1447
		1448	;-----
		1449	; Drop
		1450
		1451	align 4
		1452	.drop:
		1453
		1454	DEBUGF 1,"Dropping packet\n"
		1455
		1456	;;;; If debugging options are enabled, output the packet somwhere
		1457
		1458	.destroy_new_socket:
		1459
		1460	;;;; kill the newly created socket
		1461
		1462	call kernel_free
1529	hidnplayr	1463	add esp, 4
		1464	ret
1514	hidnplayr	1465
		1466
		1467
		1468
		1469
		1470
		1471	;---------------------------
		1472	;
		1473	; TCP_pull_out_of_band
		1474	;
		1475	; IN: eax =
		1476	; ebx = socket ptr
		1477	; edx = tcp packet ptr
		1478	;
		1479	; OUT: /
		1480	;
		1481	;---------------------------
		1482
		1483	align 4
		1484	TCP_pull_out_of_band:
		1485
		1486	DEBUGF 1,"TCP_pull_out_of_band\n"
		1487
		1488	;;;; 1282-1305
		1489
1318	hidnplayr	1490	ret
		1491
		1492
		1493
		1494	;-----------------------------------------------------------------
		1495	;
1514	hidnplayr	1496	; TCP_output
1318	hidnplayr	1497	;
1519	hidnplayr	1498	; IN: eax = socket pointer
1514	hidnplayr	1499	;; esi = ptr to data
		1500	;; ecx = number of data bytes
		1501	;
1318	hidnplayr	1502	; OUT: /
		1503	;
		1504	;-----------------------------------------------------------------
		1505	align 4
1514	hidnplayr	1506	TCP_output:
1318	hidnplayr	1507
1514	hidnplayr	1508	DEBUGF 1,"TCP_output, socket: %x\n", eax
1318	hidnplayr	1509
1514	hidnplayr	1510	; We'll detect the length of the data to be transmitted, and flags to be used
		1511	; If there is some data, or any critical controls to send (SYN / RST), then transmit
		1512	; Otherwise, investigate further
1318	hidnplayr	1513
1514	hidnplayr	1514	mov ebx, [eax + TCP_SOCKET.SND_MAX]
		1515	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
		1516	jne .not_idle
1318	hidnplayr	1517
1514	hidnplayr	1518	mov ebx, [eax + TCP_SOCKET.t_idle]
		1519	cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
		1520	jle .not_idle
1318	hidnplayr	1521
1514	hidnplayr	1522	; We have been idle for a while and no ACKS are expected to clock out any data we send..
		1523	; Slow start to get ack "clock" running again.
1318	hidnplayr	1524
1514	hidnplayr	1525	mov ebx, [eax + TCP_SOCKET.t_maxseg]
		1526	mov [eax + TCP_SOCKET.SND_CWND], ebx
1318	hidnplayr	1527
1514	hidnplayr	1528	.not_idle:
		1529	.again:
		1530	mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
		1531	sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
1318	hidnplayr	1532
1514	hidnplayr	1533	mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
		1534	cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1535	jl @f ;
		1536	mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
		1537	@@: ;
1318	hidnplayr	1538
1529	hidnplayr	1539	call TCP_outflags ; in dl
1318	hidnplayr	1540
1514	hidnplayr	1541	; If in persist timeout with window of 0, send 1 byte.
		1542	; Otherwise, if window is small but nonzero, and timer expired,
		1543	; we will send what we can and go to transmit state
1318	hidnplayr	1544
1514	hidnplayr	1545	test [eax + TCP_SOCKET.t_force], -1
		1546	jz .no_persist_timeout
1318	hidnplayr	1547
1514	hidnplayr	1548	test ecx, ecx
		1549	jnz .no_zero_window
1255	hidnplayr	1550
1533	hidnplayr	1551	cmp ebx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1552	jge @f
1255	hidnplayr	1553
1514	hidnplayr	1554	and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
1255	hidnplayr	1555
1514	hidnplayr	1556	@@:
		1557	inc ecx
		1558	jmp .no_persist_timeout
1255	hidnplayr	1559
1514	hidnplayr	1560	.no_zero_window:
1254	hidnplayr	1561
1529	hidnplayr	1562	mov [eax + TCP_SOCKET.timer_persist], 0 ;;;;
1514	hidnplayr	1563	mov [eax + TCP_SOCKET.t_rxtshift], 0
1254	hidnplayr	1564
1514	hidnplayr	1565	.no_persist_timeout:
1159	hidnplayr	1566
1514	hidnplayr	1567	;;;106
1159	hidnplayr	1568
1533	hidnplayr	1569	mov esi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1570	cmp esi, ecx
		1571	jl @f
		1572	mov esi, ecx
		1573	@@:
		1574	sub esi, ebx
1254	hidnplayr	1575
1514	hidnplayr	1576	cmp esi, -1
		1577	jne .not_minus_one
1159	hidnplayr	1578
1514	hidnplayr	1579	; If FIN has been set, but not ACKed, and we havent been called to retransmit,
		1580	; len (esi) will be -1
		1581	; Otherwise, window shrank after we sent into it.
		1582	; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
		1583	; We will enter persist state below.
		1584	; If window didn't close completely, just wait for an ACK
1159	hidnplayr	1585
1514	hidnplayr	1586	xor esi, esi
1159	hidnplayr	1587
1514	hidnplayr	1588	test ecx, ecx
		1589	jnz @f
1159	hidnplayr	1590
1529	hidnplayr	1591	mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
1274	hidnplayr	1592
1514	hidnplayr	1593	push [eax + TCP_SOCKET.SND_UNA]
		1594	pop [eax + TCP_SOCKET.SND_NXT]
		1595	@@:
1254	hidnplayr	1596
1514	hidnplayr	1597	.not_minus_one:
1254	hidnplayr	1598
1514	hidnplayr	1599	;;; 124
1159	hidnplayr	1600
1514	hidnplayr	1601	cmp esi, [eax + TCP_SOCKET.t_maxseg]
		1602	jle @f
1274	hidnplayr	1603
1514	hidnplayr	1604	mov esi, [eax + TCP_SOCKET.t_maxseg]
		1605	;sendalot = 1
1274	hidnplayr	1606
1514	hidnplayr	1607	@@:
1274	hidnplayr	1608
1514	hidnplayr	1609	;;; 128
1274	hidnplayr	1610
1514	hidnplayr	1611	mov edi, [eax + TCP_SOCKET.SND_NXT]
		1612	add edi, esi ; len
		1613	sub edi, [eax + TCP_SOCKET.SND_UNA]
1533	hidnplayr	1614	add edi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
1514	hidnplayr	1615	cmp edi, 0
		1616	jle @f
1274	hidnplayr	1617
1514	hidnplayr	1618	and dl, not (TH_FIN) ; clear the FIN flag
1159	hidnplayr	1619
1514	hidnplayr	1620	@@:
1159	hidnplayr	1621
		1622
1529	hidnplayr	1623	; set ecx to space available in receive buffer
		1624	; From now on, ecx will be the window we advertise to the other end
1159	hidnplayr	1625
1529	hidnplayr	1626	mov ecx, SOCKET_MAXDATA
1533	hidnplayr	1627	sub ecx, [eax + STREAM_SOCKET.rcv + RING_BUFFER.size]
1159	hidnplayr	1628
1514	hidnplayr	1629	;------------------------------
		1630	; Sender silly window avoidance
1159	hidnplayr	1631
1529	hidnplayr	1632	cmp ecx, [eax + TCP_SOCKET.t_maxseg]
1514	hidnplayr	1633	je .send
1274	hidnplayr	1634
1514	hidnplayr	1635	;;; TODO: 144-145
1274	hidnplayr	1636
1514	hidnplayr	1637	test [eax + TCP_SOCKET.t_force], -1
		1638	jnz .send
1274	hidnplayr	1639
1529	hidnplayr	1640	mov ebx, [eax + TCP_SOCKET.max_sndwnd]
		1641	shr ebx, 1
		1642	cmp ecx, ebx
		1643	jge .send
1274	hidnplayr	1644
1529	hidnplayr	1645	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1646	cmp ebx, [eax + TCP_SOCKET.SND_MAX]
		1647	jl .send
1254	hidnplayr	1648
1514	hidnplayr	1649	;----------------------------------------
		1650	; Check if a window update should be sent
1159	hidnplayr	1651
1529	hidnplayr	1652	test ecx, ecx ; window
		1653	jz .no_window
1159	hidnplayr	1654
1514	hidnplayr	1655	;;; TODO 154-172
1159	hidnplayr	1656
1514	hidnplayr	1657	.no_window:
1159	hidnplayr	1658
1514	hidnplayr	1659	;--------------------------
		1660	; Should a segment be sent?
1159	hidnplayr	1661
1534	hidnplayr	1662	test [eax + TCP_SOCKET.t_flags], TF_ACKNOW
1514	hidnplayr	1663	jnz .send
1159	hidnplayr	1664
1514	hidnplayr	1665	test dl, TH_SYN + TH_RST
		1666	jnz .send
1159	hidnplayr	1667
1534	hidnplayr	1668	mov ebx, [eax + TCP_SOCKET.SND_UP]
		1669	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1670	jg .send
1249	hidnplayr	1671
1514	hidnplayr	1672	test dl, TH_FIN
		1673	jz .enter_persist
1318	hidnplayr	1674
1534	hidnplayr	1675	test [eax + TCP_SOCKET.t_flags], TF_SENTFIN
1514	hidnplayr	1676	jnz .send
1254	hidnplayr	1677
1534	hidnplayr	1678	mov ebx, [eax + TCP_SOCKET.SND_NXT]
		1679	cmp ebx, [eax + TCP_SOCKET.SND_UNA]
1514	hidnplayr	1680	je .send
1254	hidnplayr	1681
1514	hidnplayr	1682	;--------------------
		1683	; Enter persist state
1318	hidnplayr	1684
1514	hidnplayr	1685	.enter_persist:
1318	hidnplayr	1686
1519	hidnplayr	1687	DEBUGF 1,"Entering persist state\n"
1318	hidnplayr	1688
1514	hidnplayr	1689	;--------------------------------------
		1690	; No reason to send a segment, just ret
1318	hidnplayr	1691
1514	hidnplayr	1692	DEBUGF 1,"No reason to send a segment\n"
1318	hidnplayr	1693
1514	hidnplayr	1694	ret
1318	hidnplayr	1695
		1696
1514	hidnplayr	1697	;-----------------------------------------------
		1698	;
		1699	; Send a segment
		1700	;
1529	hidnplayr	1701	; eax = socket pointer
1514	hidnplayr	1702	; dl = flags
		1703	;
		1704	;-----------------------------------------------
1318	hidnplayr	1705
1529	hidnplayr	1706	.send:
1318	hidnplayr	1707
1514	hidnplayr	1708	DEBUGF 1,"Preparing to send a segment\n"
1318	hidnplayr	1709
1529	hidnplayr	1710	mov edi, TCP_segment.Data ; edi will contain headersize
1318	hidnplayr	1711
1529	hidnplayr	1712	sub esp, 8 ; create some space on stack
		1713	push eax ; save this too..
		1714
1514	hidnplayr	1715	;------------------------------------
		1716	; Send options with first SYN segment
1318	hidnplayr	1717
1514	hidnplayr	1718	test dl, TH_SYN
		1719	jz .no_options
1318	hidnplayr	1720
1529	hidnplayr	1721	push [eax + TCP_SOCKET.ISS]
		1722	pop [eax + TCP_SOCKET.SND_NXT]
1318	hidnplayr	1723
1529	hidnplayr	1724	test [eax + TCP_SOCKET.t_flags], TF_NOOPT
1514	hidnplayr	1725	jnz .no_options
1318	hidnplayr	1726
1529	hidnplayr	1727	mov ecx, 1460
		1728	or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
		1729	bswap ecx
		1730	push ecx
		1731	add di, 4
1514	hidnplayr	1732
1529	hidnplayr	1733	test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
1514	hidnplayr	1734	jz .no_syn
		1735
		1736	test dl, TH_ACK
		1737	jnz .scale_opt
		1738
1529	hidnplayr	1739	test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
1514	hidnplayr	1740	jz .no_syn
		1741
		1742	.scale_opt:
1529	hidnplayr	1743	movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
		1744	or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
		1745	bswap ecx
		1746	pushd ecx
1514	hidnplayr	1747	add di, 4
1159	hidnplayr	1748
1514	hidnplayr	1749	.no_syn:
1159	hidnplayr	1750
1514	hidnplayr	1751	;------------------------------------
		1752	; Make the timestamp option if needed
1159	hidnplayr	1753
1529	hidnplayr	1754	test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
1514	hidnplayr	1755	jz .no_timestamp
1159	hidnplayr	1756
1514	hidnplayr	1757	test dl, TH_RST
		1758	jnz .no_timestamp
		1759
		1760	test dl, TH_ACK
		1761	jz .timestamp
		1762
1529	hidnplayr	1763	test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
1514	hidnplayr	1764	jz .no_timestamp
		1765
		1766	.timestamp:
1529	hidnplayr	1767	mov esi, [timer_ticks]
		1768	bswap esi
		1769	push esi
1514	hidnplayr	1770	pushw 0
1529	hidnplayr	1771	pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
1514	hidnplayr	1772	add di, 10
		1773
		1774	.no_timestamp:
		1775	;; TODO: check if we dont exceed the max segment size
		1776
		1777	.no_options:
1529	hidnplayr	1778	; eax = socket ptr
		1779	; edx = flags
		1780	; ecx = data size
		1781	; edi = header size
		1782	; esi = snd ring buff ptr
1514	hidnplayr	1783
1533	hidnplayr	1784	mov ecx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size]
		1785	cmp ecx, [eax + TCP_SOCKET.t_maxseg] ;;; right?
		1786	jle @f
		1787	mov ecx, [eax + TCP_SOCKET.t_maxseg]
		1788	@@:
1514	hidnplayr	1789	add ecx, edi ; total TCP segment size
		1790
1529	hidnplayr	1791	; Start by pushing all TCP header values in reverse order on stack
		1792	; (essentially, creating the tcp header!)
1514	hidnplayr	1793
1529	hidnplayr	1794	pushw 0 ; .UrgentPointer dw ?
		1795	pushw 0 ; .Checksum dw ?
		1796	pushw 0x00a0 ; .Window dw ? ;;;;;;;
		1797	shl edi, 2 ; .DataOffset db ? only 4 left-most bits
		1798	shl dx, 8
		1799	or dx, di ; .Flags db ?
		1800	pushw dx
		1801	shr edi, 2 ; .DataOffset db ? ;;;;
1514	hidnplayr	1802
1529	hidnplayr	1803	push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
		1804	ntohld [esp]
1159	hidnplayr	1805
1529	hidnplayr	1806	push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
		1807	ntohld [esp]
1159	hidnplayr	1808
1529	hidnplayr	1809	push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
		1810	ntohlw [esp]
1249	hidnplayr	1811
1529	hidnplayr	1812	push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
		1813	ntohlw [esp]
1274	hidnplayr	1814
1533	hidnplayr	1815	push edi ; header size
1274	hidnplayr	1816
1529	hidnplayr	1817	; Create the IP packet
		1818	mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
		1819	mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
		1820	mov di, IP_PROTO_TCP shl 8 + 128
		1821	call IPv4_output
		1822	jz .fail
1274	hidnplayr	1823
1529	hidnplayr	1824	;-----------------------------------------
		1825	; Move TCP header from stack to TCP packet
1274	hidnplayr	1826
1533	hidnplayr	1827	push ecx
		1828	mov ecx, [esp+4]
		1829	lea esi, [esp+4+4]
1529	hidnplayr	1830	shr ecx, 2
		1831	rep movsd
1533	hidnplayr	1832	pop ecx ; full TCP packet size
1274	hidnplayr	1833
1533	hidnplayr	1834	pop esi ; headersize
		1835	add esp, esi
1254	hidnplayr	1836
1533	hidnplayr	1837	mov [esp + 4], eax ; packet ptr
1530	hidnplayr	1838	mov [esp + 4+4], edx ; packet size
1254	hidnplayr	1839
1533	hidnplayr	1840	mov edx, edi ; begin of data
		1841	sub edx, esi ; begin of packet (edi = begin of data)
		1842	push ecx
		1843	sub ecx, esi ; data size
1159	hidnplayr	1844
1514	hidnplayr	1845	;--------------
		1846	; Copy the data
1159	hidnplayr	1847
1529	hidnplayr	1848	; eax = ptr to ring struct
		1849	; ecx = buffer size
		1850	; edi = ptr to buffer
1249	hidnplayr	1851
1533	hidnplayr	1852	mov eax, [esp+4] ; socket ptr
		1853	push edx
		1854	add eax, STREAM_SOCKET.snd
1529	hidnplayr	1855	call SOCKET_ring_read
		1856	pop esi ecx
		1857	pop eax
1254	hidnplayr	1858
1533	hidnplayr	1859	test [esi + TCP_segment.Flags], TH_SYN + TH_FIN
		1860	jz @f
		1861	inc [eax + TCP_SOCKET.SND_NXT]
		1862	;;; TODO: update sentfin flag
		1863	@@:
1254	hidnplayr	1864
1533	hidnplayr	1865	;; add [eax + TCP_SOCKET.SND_NXT], ecx
		1866
		1867	mov edx, [eax + TCP_SOCKET.SND_NXT]
		1868	cmp edx, [eax + TCP_SOCKET.SND_MAX]
		1869	jle @f
		1870	mov [eax + TCP_SOCKET.SND_MAX], edx
		1871
		1872	;;;; TODO: time transmission (420)
		1873	@@:
		1874
		1875	;;; TODO: set retransmission timer
		1876
		1877	;--------------------
		1878	; Create the checksum
		1879
1529	hidnplayr	1880	DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
1159	hidnplayr	1881
1529	hidnplayr	1882	TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
		1883	mov [esi+TCP_segment.Checksum], dx
		1884
1514	hidnplayr	1885	;----------------
		1886	; Send the packet
1159	hidnplayr	1887
1529	hidnplayr	1888	DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
		1889	call [ebx + NET_DEVICE.transmit]
		1890	ret
1159	hidnplayr	1891
1514	hidnplayr	1892
1529	hidnplayr	1893	.fail:
		1894	pop ecx
		1895	add esp, ecx
		1896	add esp, 4+4+8+4
		1897	DEBUGF 1,"TCP_output: failed\n"
1159	hidnplayr	1898	ret
		1899
1529	hidnplayr	1900
		1901
1514	hidnplayr	1902	;-------------------------
		1903	;
		1904	; TCP_outflags
		1905	;
		1906	; IN: eax = socket ptr
		1907	;
		1908	; OUT: edx = flags
		1909	;
		1910	;-------------------------
1249	hidnplayr	1911	align 4
1514	hidnplayr	1912	TCP_outflags:
1254	hidnplayr	1913
1514	hidnplayr	1914	mov edx, [eax + TCP_SOCKET.t_state]
		1915	movzx edx, byte [edx + .flaglist]
1254	hidnplayr	1916
1514	hidnplayr	1917	DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
		1918
1159	hidnplayr	1919	ret
		1920
1514	hidnplayr	1921	.flaglist:
1159	hidnplayr	1922
1514	hidnplayr	1923	db TH_RST + TH_ACK ; TCB_CLOSED
		1924	db 0 ; TCB_LISTEN
		1925	db TH_SYN ; TCB_SYN_SENT
		1926	db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
		1927	db TH_ACK ; TCB_ESTABLISHED
		1928	db TH_ACK ; TCB_CLOSE_WAIT
		1929	db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
		1930	db TH_SYN + TH_ACK ; TCB_CLOSING
		1931	db TH_SYN + TH_ACK ; TCB_LAST_ACK
		1932	db TH_ACK ; TCB_FIN_WAIT_2
		1933	db TH_ACK ; TCB_TIMED_WAIT
1249	hidnplayr	1934
1514	hidnplayr	1935
1529	hidnplayr	1936
		1937
1514	hidnplayr	1938	;-------------------------
		1939	;
		1940	; TCP_drop
		1941	;
		1942	; IN: eax = socket ptr
		1943	;
		1944	; OUT: /
		1945	;
		1946	;-------------------------
1249	hidnplayr	1947	align 4
1514	hidnplayr	1948	TCP_drop:
1254	hidnplayr	1949
1514	hidnplayr	1950	DEBUGF 1,"TCP_drop\n"
1254	hidnplayr	1951
1514	hidnplayr	1952	; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
		1953	; jl .no_syn_received
1159	hidnplayr	1954
1514	hidnplayr	1955	mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
1159	hidnplayr	1956
1514	hidnplayr	1957	call TCP_output
1254	hidnplayr	1958
1514	hidnplayr	1959	; .no_syn_received:
		1960
1159	hidnplayr	1961	ret
		1962
		1963
1254	hidnplayr	1964
		1965
1159	hidnplayr	1966
1514	hidnplayr	1967	;---------------------------------------
		1968	;
1519	hidnplayr	1969	; The easy way to send an ACK/RST/keepalive segment
1514	hidnplayr	1970	;
1529	hidnplayr	1971	; TCP_respond_socket:
		1972	;
		1973	; IN: ebx = socket ptr
1519	hidnplayr	1974	; cl = flags
1514	hidnplayr	1975	;
1529	hidnplayr	1976	;--------------------------------------
1514	hidnplayr	1977	align 4
1529	hidnplayr	1978	TCP_respond_socket:
1254	hidnplayr	1979
1529	hidnplayr	1980	DEBUGF 1,"TCP_respond_socket\n"
1159	hidnplayr	1981
1519	hidnplayr	1982	;---------------------
		1983	; Create the IP packet
		1984
1529	hidnplayr	1985	push cx ebx
		1986	mov eax, [ebx + IP_SOCKET.RemoteIP]
		1987	mov ebx, [ebx + IP_SOCKET.LocalIP]
1519	hidnplayr	1988	mov ecx, TCP_segment.Data
1529	hidnplayr	1989	mov di , IP_PROTO_TCP shl 8 + 128
		1990	call IPv4_output
1519	hidnplayr	1991	test edi, edi
		1992	jz .error
1529	hidnplayr	1993	pop esi cx
		1994	push edx eax
1519	hidnplayr	1995
1529	hidnplayr	1996	;-----------------------------------------------
		1997	; Fill in the TCP header by using the socket ptr
1519	hidnplayr	1998
1529	hidnplayr	1999	mov ax, [esi + TCP_SOCKET.LocalPort]
		2000	rol ax, 8
		2001	stosw
		2002	mov ax, [esi + TCP_SOCKET.RemotePort]
		2003	rol ax, 8
		2004	stosw
		2005	mov eax, [esi + TCP_SOCKET.SND_NXT]
		2006	bswap eax
		2007	stosd
		2008	mov eax, [esi + TCP_SOCKET.RCV_NXT]
		2009	bswap eax
		2010	stosd
		2011	mov al, 0x50 ; Dataoffset: 20 bytes
		2012	stosb
		2013	mov al, cl
		2014	stosb
		2015	mov ax, [esi + TCP_SOCKET.RCV_WND]
		2016	rol ax, 8
		2017	stosw ; window
		2018	xor eax, eax
		2019	stosd ; checksum + urgentpointer
1519	hidnplayr	2020
		2021	;---------------------
		2022	; Fill in the checksum
		2023
		2024	.checksum:
1529	hidnplayr	2025	sub edi, TCP_segment.Data
		2026	mov ecx, TCP_segment.Data
		2027	xchg esi, edi
		2028	TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
		2029	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2030
		2031	;--------------------
		2032	; And send the segment
		2033
		2034	call [ebx + NET_DEVICE.transmit]
1159	hidnplayr	2035	ret
		2036
1519	hidnplayr	2037	.error:
1529	hidnplayr	2038	DEBUGF 1,"TCP_respond failed\n"
		2039	add esp, 2+4
1159	hidnplayr	2040
1519	hidnplayr	2041	ret
1514	hidnplayr	2042
1529	hidnplayr	2043
		2044
		2045	;-------------------------
		2046	; TCP_respond.segment:
		2047	;
		2048	; IN: edx = segment ptr (a previously received segment)
		2049	; cl = flags
		2050
		2051	align 4
		2052	TCP_respond_segment:
		2053
		2054	DEBUGF 1,"TCP_respond_segment\n"
		2055
		2056	;---------------------
		2057	; Create the IP packet
		2058
		2059	push cx edx
		2060	mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
		2061	mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
		2062	mov ecx, TCP_segment.Data
		2063	mov di , IP_PROTO_TCP shl 8 + 128
		2064	call IPv4_output
		2065	jz .error
1533	hidnplayr	2066	pop esi cx
1529	hidnplayr	2067
		2068	push edx eax
		2069
1519	hidnplayr	2070	;---------------------------------------------------
		2071	; Fill in the TCP header by using a received segment
		2072
		2073	mov ax, [esi + TCP_segment.DestinationPort]
		2074	rol ax, 8
		2075	stosw
		2076	mov ax, [esi + TCP_segment.SourcePort]
		2077	rol ax, 8
		2078	stosw
		2079	mov eax, [esi + TCP_segment.AckNumber]
		2080	bswap eax
		2081	stosd
		2082	xor eax, eax
		2083	stosd
		2084	mov al, 0x50 ; Dataoffset: 20 bytes
		2085	stosb
		2086	mov al, cl
		2087	stosb
		2088	mov ax, 1280
		2089	rol ax, 8
		2090	stosw ; window
		2091	xor eax, eax
		2092	stosd ; checksum + urgentpointer
		2093
1529	hidnplayr	2094	;---------------------
		2095	; Fill in the checksum
1519	hidnplayr	2096
1529	hidnplayr	2097	.checksum:
		2098	lea esi, [edi - TCP_segment.Data]
		2099	mov ecx, TCP_segment.Data
		2100	TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
		2101	mov [esi+TCP_segment.Checksum], dx
1519	hidnplayr	2102
1529	hidnplayr	2103	;--------------------
		2104	; And send the segment
1519	hidnplayr	2105
1529	hidnplayr	2106	call [ebx + NET_DEVICE.transmit]
		2107	ret
1519	hidnplayr	2108
1529	hidnplayr	2109	.error:
		2110	DEBUGF 1,"TCP_respond failed\n"
		2111	add esp, 2+4
1519	hidnplayr	2112
		2113	ret
		2114
		2115
		2116
1254	hidnplayr	2117
		2118	;---------------------------------------------------------------------------
		2119	;
		2120	; TCP_API
		2121	;
		2122	; This function is called by system function 75
		2123	;
		2124	; IN: subfunction number in bl
		2125	; device number in bh
		2126	; ecx, edx, .. depends on subfunction
		2127	;
		2128	; OUT:
		2129	;
		2130	;---------------------------------------------------------------------------
		2131	align 4
		2132	TCP_API:
		2133
		2134	movzx eax, bh
		2135	shl eax, 2
		2136
		2137	test bl, bl
		2138	jz .packets_tx ; 0
		2139	dec bl
		2140	jz .packets_rx ; 1
		2141
		2142	.error:
		2143	mov eax, -1
		2144	ret
		2145
		2146	.packets_tx:
1514	hidnplayr	2147	add eax, TCP_segments_tx
1254	hidnplayr	2148	mov eax, [eax]
		2149	ret
		2150
		2151	.packets_rx:
1514	hidnplayr	2152	add eax, TCP_segments_rx
1254	hidnplayr	2153	mov eax, [eax]
		2154	ret

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(root)/kernel/branches/net/network/tcp.inc – Rev 1534