forked from KolibriOS/kolibrios
084d99548d
-Ommitted unnescessary copying of packets in some drivers. -Some small updates in TCP (perhaps 50% done ?) git-svn-id: svn://kolibrios.org@1519 a494cfbc-eb01-0410-851d-a64ba20cac60
2150 lines
42 KiB
PHP
2150 lines
42 KiB
PHP
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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;; ;;
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;; Copyright (C) KolibriOS team 2004-2010. All rights reserved. ;;
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;; Distributed under terms of the GNU General Public License ;;
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;; ;;
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;; TCP.INC ;;
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;; ;;
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;; Part of the tcp/ip network stack for KolibriOS ;;
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;; ;;
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;; Written by hidnplayr@kolibrios.org ;;
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;; ;;
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;; Based on the code of 4.4BSD ;;
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;; ;;
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;; GNU GENERAL PUBLIC LICENSE ;;
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;; Version 2, June 1991 ;;
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;; ;;
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;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
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$Revision$
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; Socket states
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TCB_CLOSED equ 0
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TCB_LISTEN equ 1
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TCB_SYN_SENT equ 2
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TCB_SYN_RECEIVED equ 3
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TCB_ESTABLISHED equ 4
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TCB_CLOSE_WAIT equ 5
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TCB_FIN_WAIT_1 equ 6
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TCB_CLOSING equ 7
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TCB_LAST_ACK equ 8
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TCB_FIN_WAIT_2 equ 9
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TCB_TIMED_WAIT equ 10
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; Socket Flags
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TF_ACKNOW equ 1 shl 0 ; ack peer immediately
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TF_DELACK equ 1 shl 1 ; ack, but try to delay it
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TF_NODELAY equ 1 shl 2 ; don't delay packets to coalesce
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TF_NOOPT equ 1 shl 3 ; don't use tcp options
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TF_SENTFIN equ 1 shl 4 ; have sent FIN
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TF_REQ_SCALE equ 1 shl 5 ; have/will request window scaling
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TF_RCVD_SCALE equ 1 shl 6 ; other side has requested scaling
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TF_REQ_TSTMP equ 1 shl 7 ; have/will request timestamps
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TF_RCVD_TSTMP equ 1 shl 8 ; a timestamp was received in SYN
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TF_SACK_PERMIT equ 1 shl 9 ; other side said I could SACK
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; Segment flags
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TH_FIN equ 1 shl 0
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TH_SYN equ 1 shl 1
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TH_RST equ 1 shl 2
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TH_PUSH equ 1 shl 3
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TH_ACK equ 1 shl 4
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TH_URG equ 1 shl 5
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; Segment header options
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TCP_OPT_EOL equ 0 ; End of option list.
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TCP_OPT_NOP equ 1 ; No-Operation.
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TCP_OPT_MAXSEG equ 2 ; Maximum Segment Size.
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TCP_OPT_WINDOW equ 3 ; window scale
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TCP_OPT_TIMESTAMP equ 8
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; Fundamental timer values
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TCP_time_MSL equ 47 ; max segment lifetime (30s)
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TCP_time_re_min equ 2 ; min retransmission (1,28s)
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TCP_time_re_max equ 100 ; max retransmission (64s)
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TCP_time_pers_min equ 8 ; min persist (5,12s)
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TCP_time_pers_max equ 94 ; max persist (60,16s)
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TCP_time_keep_init equ 118 ; connectione stablishment (75,52s)
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TCP_time_keep_idle equ 4608 ; idle time before 1st probe (2h)
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TCP_time_keep_interval equ 118 ; between probes when no response (75,52s)
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TCP_time_rtt_default equ 5 ; default Round Trip Time (3,2s)
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; timer constants
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TCP_max_rxtshift equ 12 ; max retransmissions waiting for ACK
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TCP_max_keepcnt equ 8 ; max keepalive probes
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struct TCP_segment
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.SourcePort dw ?
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.DestinationPort dw ?
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.SequenceNumber dd ?
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.AckNumber dd ?
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.DataOffset db ? ; DataOffset[0-3 bits] and Reserved[4-7]
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.Flags db ? ; Reserved[0-1 bits]|URG|ACK|PSH|RST|SYN|FIN
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.Window dw ?
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.Checksum dw ?
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.UrgentPointer dw ?
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.Data: ; ..or options
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ends
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struct tcp_in_queue_entry
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.data_ptr dd ?
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.data_size dd ?
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.offset dd ?
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.size:
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ends
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struct tcp_out_queue_entry
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.data_ptr dd ?
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.data_size dd ?
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.size:
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ends
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align 4
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uglobal
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TCP_segments_tx rd IP_MAX_INTERFACES
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TCP_segments_rx rd IP_MAX_INTERFACES
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TCP_bytes_rx rq IP_MAX_INTERFACES
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TCP_bytes_tx rq IP_MAX_INTERFACES
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TCP_sequence_num dd ?
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endg
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;-----------------------------------------------------------------
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;
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; TCP_init
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;
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; This function resets all TCP variables
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;
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; IN: /
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; OUT: /
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;
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;-----------------------------------------------------------------
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align 4
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TCP_init:
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xor eax, eax
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mov edi, TCP_segments_tx
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mov ecx, (6*IP_MAX_INTERFACES)
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rep stosd
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mov [TCP_sequence_num], 1
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ret
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;----------------------
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;
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;
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;----------------------
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align 4
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TCP_timer_160ms:
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mov eax, net_sockets
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.loop:
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mov eax, [eax + SOCKET.NextPtr]
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or eax, eax
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jz .exit
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cmp [eax + SOCKET.Type], IP_PROTO_TCP
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jne .loop
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dec [eax + TCP_SOCKET.timer_ack]
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jnz .loop
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DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
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push eax
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call TCP_respond
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pop eax
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jmp .loop
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.exit:
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ret
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;-----------------------------------------------------------------
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;
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;
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;-----------------------------------------------------------------
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align 4
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TCP_timer_640ms:
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; Update TCP sequence number
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add [TCP_sequence_num], 64000
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; scan through all the active TCP sockets, decrementing ALL timers
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; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires
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mov eax, net_sockets
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.loop:
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mov eax, [eax + SOCKET.NextPtr]
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.check_only:
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or eax, eax
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jz .exit
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cmp [eax + SOCKET.Type], IP_PROTO_TCP
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jne .loop
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dec [eax + TCP_SOCKET.timer_retransmission]
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jnz .check_more2
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DEBUGF 1,"socket %x: Retransmission timer expired\n", eax
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push eax
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call TCP_output
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pop eax
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.check_more2:
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dec [eax + TCP_SOCKET.timer_keepalive]
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jnz .check_more3
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DEBUGF 1,"socket %x: Keepalive expired\n", eax
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;;; TODO: check socket state and handle accordingly
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.check_more3:
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dec [eax + TCP_SOCKET.timer_timed_wait]
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jnz .check_more5
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DEBUGF 1,"socket %x: 2MSL timer expired\n", eax
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.check_more5:
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dec [eax + TCP_SOCKET.timer_persist]
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jnz .loop
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DEBUGF 1,"socket %x: persist timer expired\n", eax
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jmp .loop
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.exit:
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ret
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;-----------------------------------------------------------------
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;
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; TCP_input:
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;
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; IN: [esp] = ptr to buffer
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; [esp+4] = buffer size
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; ebx = ptr to device struct
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; ecx = segment size
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; edx = ptr to TCP segment
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;
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; esi = ipv4 source address
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; edi = ipv4 dest address
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;
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; OUT: /
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;
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;-----------------------------------------------------------------
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align 4
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TCP_input:
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DEBUGF 1,"TCP_input\n"
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; 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.
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movzx eax, [edx + TCP_segment.DataOffset]
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and eax, 0xf0
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shr al , 2
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DEBUGF 1,"data offset: %u\n", eax
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cmp eax, 20
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jl .drop
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cmp eax, ecx
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jg .drop
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;-------------------------------
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; Now, re-calculate the checksum
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push eax edx ebx
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push edi
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push esi
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mov esi, edx
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call TCP_checksum ; this destroys edx, ecx and esi (but not edi! :)
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pop ebx edx eax
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cmp [edx + TCP_segment.Checksum], 0
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jnz .drop
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DEBUGF 1,"Checksum is correct\n"
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;-----------------------------------------------------------------------------------------
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; Check if this packet has a timestamp option (We do it here so we can process it quickly)
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cmp eax, 20 + 12 ; Timestamp option is 12 bytes
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jl .no_timestamp
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je .is_ok
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cmp byte [edx + TCP_segment.Data + 12], 0 ; end of option list
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jne .no_timestamp
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.is_ok:
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test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set
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jnz .no_timestamp
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cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header
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jne .no_timestamp
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DEBUGF 1,"timestamp ok\n"
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; TODO: Parse the options
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; TODO: Set a Bit in the TCP to tell all options are parsed
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ret
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.no_timestamp:
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;-------------------------------------------
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; Convert Big-endian values to little endian
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ntohld [edx + TCP_segment.SequenceNumber]
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ntohld [edx + TCP_segment.AckNumber]
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ntohlw [edx + TCP_segment.Window]
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ntohlw [edx + TCP_segment.UrgentPointer]
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;------------------------------------------------------------
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; Next thing to do is find the TCB (thus, the socket pointer)
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; IP Packet TCP Destination Port = local Port
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; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0)
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; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
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mov ebx, net_sockets
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.socket_loop:
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mov ebx, [ebx + SOCKET.NextPtr]
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or ebx, ebx
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jz .drop_with_reset
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cmp [ebx + SOCKET.Type], IP_PROTO_TCP
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jne .socket_loop
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mov ax, [edx + TCP_segment.DestinationPort]
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cmp [ebx + TCP_SOCKET.LocalPort], ax
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jne .socket_loop
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mov eax, [ebx + IP_SOCKET.RemoteIP]
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cmp eax, esi
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je @f
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test eax, eax
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jnz .socket_loop
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@@:
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mov ax, [ebx + TCP_SOCKET.RemotePort]
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cmp [edx + TCP_segment.SourcePort] , ax
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je .found_socket
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test ax, ax
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jnz .socket_loop
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.found_socket:
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DEBUGF 1,"Socket ptr: %x\n", ebx
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; ebx now contains the pointer to the socket
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;----------------------------
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; Check if socket isnt closed
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cmp [TCP_SOCKET.t_state], TCB_CLOSED
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je .drop
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;----------------
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; Lock the socket
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add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
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call wait_mutex
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sub ebx, SOCKET.lock
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;---------------------------------------
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; unscale the window into a 32 bit value ;;;;;;
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movzx eax, [edx + TCP_segment.Window]
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xchg al, ah
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test [edx + TCP_segment.Flags], TH_SYN
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jnz .no_syn
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mov cl , [ebx + TCP_SOCKET.SND_SCALE]
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shl eax, cl
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.no_syn:
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;-----------------------------------
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; Is this socket a listening socket?
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; If so, create a new socket
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test [ebx + SOCKET.options], SO_ACCEPTCON
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jz .no_accept_conn
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; TODO: create a new socket
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.no_accept_conn:
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;----------------------------
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; Compute window scale factor
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; TODO
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;-------------------------------------
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; Reset idle timer and keepalive timer
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;;;; TODO: idle timer?
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mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
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;-----------------------------------------
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; Process TCP options if not in LISTEN state
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test [ebx + TCP_SOCKET.t_state], TCB_LISTEN
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jz .dont_do_options
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call TCP_do_options
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.dont_do_options:
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;-----------------------------------------------------------------------
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; Time to do some header prediction (Original Principle by Van Jacobson)
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; There are two common cases for an uni-directional data transfer.
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;
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; General rule: the packets has no control flags, is in-sequence,
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; window width didnt change and we're not retransmitting.
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;
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; Second rules:
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; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer.
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; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer
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;
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; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
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; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
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cmp [TCP_SOCKET.t_state], TCB_ESTABLISHED
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jnz .not_uni_xfer
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test [TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
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jnz .not_uni_xfer
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test [TCP_segment.Flags], TH_ACK
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jz .not_uni_xfer
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mov eax, [edx + TCP_segment.SequenceNumber]
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cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
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jne .not_uni_xfer
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movzx eax, [edx + TCP_segment.Window] ;;;;;
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cmp eax, [ebx + TCP_SOCKET.SND_WND]
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jne .not_uni_xfer
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mov eax, [ebx + TCP_SOCKET.SND_NXT]
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cmp eax, [ebx + TCP_SOCKET.SND_MAX]
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jne .not_uni_xfer
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;-------------------------------------------------------------------------------
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; If last ACK falls within this segment's sequence number, record the timestamp.
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; TODO: check if it has a timestamp
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;---------------------------------------
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; check if we are sender in the uni-xfer
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; If the following 4 conditions are all true, this segment is a pure ACK.
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;
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; - The segment contains no data (ti_len is 0).
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movzx eax, [edx + TCP_segment.DataOffset]
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and eax, 11110000b
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shr eax, 2
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sub ecx, eax
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jnz .not_sender
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; - The acknowledgment field in the segment (ti_ack) is greater than the largest unacknowledged sequence number (snd_una).
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; Since this test is "greater than" and not "greater than or equal to," it is true only if some positive amount of data is acknowledged by the ACK.
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mov eax, [edx + TCP_segment.AckNumber]
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cmp eax, [ebx + TCP_SOCKET.SND_UNA]
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jle .not_uni_xfer
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; - The acknowledgment field in the segment (ti_ack) is less than or equal to the maximum sequence number sent (snd_max).
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; mov eax, [edx + TCP_segment.Ack]
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cmp eax, [ebx + TCP_SOCKET.SND_MAX]
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jg .not_uni_xfer
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; - The congestion window (snd_cwnd) is greater than or equal to the current send window (snd_wnd).
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; 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.
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mov eax, [ebx + TCP_SOCKET.SND_CWND]
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cmp eax, [ebx + TCP_SOCKET.SND_WND]
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jl .not_uni_xfer
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DEBUGF 1,"Header prediction: we are sender\n"
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;---------------------------------
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; Packet is a pure ACK, process it
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; Update RTT estimators
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; Delete acknowledged bytes from send buffer
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; Stop retransmit timer
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mov [ebx + TCP_SOCKET.timer_ack], 0
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; Awaken waiting processes
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mov eax, ebx
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call SOCKET_notify_owner
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; Generate more output
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call TCP_output
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jmp .drop
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;-------------------------------------------------
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; maybe we are the receiver in the uni-xfer then..
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.not_sender:
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; The amount of data in the segment (ti_len) is greater than 0 (data count is in ecx)
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; The acknowledgment field (ti_ack) equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
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mov eax, [edx + TCP_segment.AckNumber]
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cmp eax, [ebx + TCP_SOCKET.SND_UNA]
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jne .not_uni_xfer
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; The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp).
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;;;;
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jnz .not_uni_xfer
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; There is room in the receive buffer for the data in the segment.
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;;;;
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jnz .not_uni_xfer
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;-------------------------------------
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; Complete processing of received data
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DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
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; The next expected receive sequence number (rcv_nxt) is incremented by the number of bytes of data.
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add [ebx + TCP_SOCKET.RCV_NXT], ecx
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; Add the data to the socket buffer
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mov eax, ebx
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;;; mov...
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call SOCKET_input
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|
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; The delayed-ACK flag is set and the input processing is complete.
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jmp .drop
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;----------------------------------------------------
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; Header prediction failed, doing it the slow way..
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.not_uni_xfer:
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|
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DEBUGF 1,"Header prediction failed\n"
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|
|
;------------------------
|
|
; calculate header length ;;;;; we already calculated this before!
|
|
movzx eax, [edx + TCP_segment.DataOffset]
|
|
and eax, 0xf0
|
|
shr eax, 2
|
|
|
|
; Update edx to point to data..
|
|
add edx, eax
|
|
; ..and ecx to give data size
|
|
sub ecx, eax
|
|
|
|
;------------------------------
|
|
; Calculate receive window size
|
|
|
|
;;;;
|
|
|
|
|
|
;-------------------------
|
|
; TCP slow input procedure
|
|
|
|
DEBUGF 1,"TCP slow input procedure\n"
|
|
|
|
cmp [eax + TCP_SOCKET.t_state], TCB_LISTEN
|
|
je .LISTEN
|
|
|
|
cmp [eax + TCP_SOCKET.t_state], TCB_SYN_SENT
|
|
je .SYN_SENT
|
|
|
|
|
|
;--------------------------------------------
|
|
; Protection Against Wrapped Sequence Numbers
|
|
|
|
|
|
; First, check timestamp if present
|
|
|
|
;;;; TODO
|
|
|
|
; Then, check if at least some bytes of data are within window
|
|
|
|
;;;; TODO
|
|
|
|
jmp .trim_then_step6
|
|
|
|
align 4
|
|
.LISTEN:
|
|
|
|
DEBUGF 1,"TCP state: listen\n"
|
|
|
|
test [edx + TCP_segment.Flags], TH_RST
|
|
jnz .drop
|
|
|
|
test [edx + TCP_segment.Flags], TH_ACK
|
|
jnz .drop_with_reset
|
|
|
|
test [edx + TCP_segment.Flags], TH_SYN
|
|
jz .drop
|
|
|
|
; TODO: check if it's a broadcast or multicast, and drop if so
|
|
|
|
;;; 28.6
|
|
|
|
; create a new socket and fill in the nescessary variables
|
|
|
|
;; Exit if backlog queue is full
|
|
; mov ax, [ebx + TCP_SOCKET.backlog_cur]
|
|
; cmp ax, [ebx + TCP_SOCKET.backlog]
|
|
; jae .exit
|
|
|
|
; Allocate new socket
|
|
call SOCKET_alloc
|
|
;;; jz .fail
|
|
|
|
; Copy structure from current socket to new, (including lock!)
|
|
; We start at PID to reserve the socket num, and the 2 pointers at beginning of socket
|
|
lea esi, [edx + SOCKET.PID]
|
|
lea edi, [eax + SOCKET.PID]
|
|
mov ecx, (TCP_SOCKET.end - SOCKET.PID + 3)/4
|
|
rep movsd
|
|
|
|
;; Push pointer to new socket to queue
|
|
; movzx ecx, [ebx + TCP_SOCKET.backlog_cur]
|
|
; inc [ebx + TCP_SOCKET.backlog_cur]
|
|
; mov [ebx + TCP_SOCKET.end + ecx*4], eax
|
|
|
|
mov [eax + IP_SOCKET.RemoteIP], esi ; IP source address
|
|
|
|
mov cx, [edx + TCP_segment.SourcePort]
|
|
mov [eax + TCP_SOCKET.RemotePort], cx
|
|
|
|
mov ecx, [edx + TCP_segment.SequenceNumber]
|
|
mov [eax + TCP_SOCKET.IRS], ecx
|
|
|
|
mov ecx, [eax + TCP_SOCKET.ISS]
|
|
mov [eax + TCP_SOCKET.SND_NXT], ecx
|
|
|
|
jmp .trim_then_step6
|
|
|
|
|
|
|
|
align 4
|
|
.SYN_SENT:
|
|
|
|
DEBUGF 1,"TCP state: syn_sent\n"
|
|
|
|
test [edx + TCP_segment.Flags], TH_ACK
|
|
jz @f
|
|
|
|
mov eax, [edx + TCP_segment.AckNumber]
|
|
cmp eax, [ebx + TCP_SOCKET.ISS]
|
|
jle .drop_with_reset
|
|
|
|
mov eax, [edx + TCP_segment.AckNumber]
|
|
cmp eax, [ebx + TCP_SOCKET.SND_MAX]
|
|
jg .drop_with_reset
|
|
@@:
|
|
|
|
|
|
test [edx + TCP_segment.Flags], TH_RST
|
|
jz @f
|
|
|
|
test [edx + TCP_segment.Flags], TH_ACK
|
|
jz .drop
|
|
|
|
;tp = tcp_drop(tp, ECONNREFUSED)
|
|
|
|
jmp .drop
|
|
@@:
|
|
|
|
test [edx + TCP_segment.Flags], TH_SYN
|
|
jz .drop
|
|
|
|
; now, process received SYN in response to an active open
|
|
test [edx + TCP_segment.Flags], TH_ACK
|
|
jz @f
|
|
|
|
mov eax, [edx + TCP_segment.AckNumber]
|
|
mov [ebx + TCP_SOCKET.SND_UNA], eax
|
|
|
|
mov eax, [ebx + TCP_SOCKET.SND_UNA]
|
|
cmp eax, [ebx + TCP_SOCKET.SND_NXT]
|
|
jle @f
|
|
mov [ebx + TCP_SOCKET.SND_NXT], eax
|
|
|
|
mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
|
|
mov [ebx + TCP_SOCKET.timer_retransmission], 0
|
|
|
|
mov eax, [edx + TCP_segment.SequenceNumber]
|
|
mov [ebx + TCP_SOCKET.IRS], eax
|
|
|
|
; TODO: set socket state to connected
|
|
|
|
mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
|
|
|
|
; TODO: check if we should scale the connection (567-572)
|
|
; TODO: update RTT estimators
|
|
|
|
|
|
@@:
|
|
|
|
; We have received a syn but no ACK, so we are having a simultaneous open..
|
|
mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
|
|
|
|
;-------------------------------------
|
|
; Common processing for receipt of SYN
|
|
|
|
.trimthenstep6:
|
|
|
|
inc [edx + TCP_segment.SequenceNumber]
|
|
|
|
cmp cx, [ebx + TCP_SOCKET.RCV_WND]
|
|
jle @f
|
|
|
|
movzx eax, cx
|
|
sub ax, [ebx + TCP_SOCKET.RCV_WND]
|
|
; TODO: 592
|
|
mov cx, [ebx + TCP_SOCKET.RCV_WND]
|
|
; TODO...
|
|
@@:
|
|
;;;;;
|
|
;;; jmp .step6
|
|
|
|
|
|
|
|
|
|
|
|
align 4
|
|
.trim_then_step6:
|
|
|
|
DEBUGF 1,"Trim, then step 6\n"
|
|
|
|
;----------------------------
|
|
; trim any data not in window
|
|
|
|
mov eax, [ebx + TCP_SOCKET.RCV_NXT]
|
|
sub eax, [edx + TCP_segment.SequenceNumber]
|
|
|
|
test eax, eax
|
|
jz .no_drop
|
|
|
|
test [edx + TCP_segment.Flags], TH_SYN
|
|
jz .no_drop
|
|
|
|
and [edx + TCP_segment.Flags], not (TH_SYN)
|
|
inc [edx + TCP_segment.SequenceNumber]
|
|
|
|
cmp [edx + TCP_segment.UrgentPointer], 1
|
|
jl @f
|
|
|
|
dec [edx + TCP_segment.UrgentPointer]
|
|
|
|
jmp .no_drop
|
|
@@:
|
|
|
|
and [edx + TCP_segment.Flags], not (TH_URG)
|
|
dec eax
|
|
|
|
.no_drop:
|
|
|
|
; eax holds number of bytes to drop
|
|
|
|
|
|
;----------------------------------
|
|
; Check for entire duplicate packet
|
|
|
|
cmp eax, ecx
|
|
jge .duplicate
|
|
|
|
;;; TODO: figure 28.30
|
|
|
|
;; inc [TCP_segments_rx]
|
|
|
|
;; add dword [TCP_bytes_rx], ecx
|
|
;; adc dword [TCP_bytes_rx+4], 0
|
|
|
|
;------------------------
|
|
; Check for duplicate FIN
|
|
|
|
test [edx + TCP_segment.Flags], TH_FIN
|
|
jz @f
|
|
inc ecx
|
|
cmp eax, ecx
|
|
dec ecx
|
|
jne @f
|
|
|
|
mov eax, ecx
|
|
and [edx + TCP_segment.Flags], not TH_FIN
|
|
;;; TODO: set ACKNOW flag
|
|
|
|
jmp .no_duplicate
|
|
@@:
|
|
|
|
; Handle the case when a bound socket connects to itself
|
|
; Allow packets with a SYN and an ACKto continue with the processing
|
|
|
|
|
|
;-------------------------------------
|
|
; Generate duplicate ACK if nescessary
|
|
|
|
; This code also handles simultaneous half-open or self-connects
|
|
|
|
test eax, eax
|
|
jnz .drop_after_ack
|
|
|
|
cmp [edx + TCP_segment.Flags], TH_ACK
|
|
jz .drop_after_ack
|
|
|
|
.duplicate:
|
|
|
|
;----------------------------------------
|
|
; Update statistics for duplicate packets
|
|
|
|
;;; TODO
|
|
|
|
;;; DROP the packet ??
|
|
|
|
.no_duplicate:
|
|
|
|
;-----------------------------------------------
|
|
; Remove duplicate data and update urgent offset
|
|
|
|
add [edx + TCP_segment.SequenceNumber], eax
|
|
|
|
;;; TODO
|
|
|
|
sub [edx + TCP_segment.UrgentPointer], ax
|
|
jg @f
|
|
|
|
and [edx + TCP_segment.Flags], not (TH_URG)
|
|
mov [edx + TCP_segment.UrgentPointer], 0
|
|
@@:
|
|
|
|
;--------------------------------------------------
|
|
; Handle data that arrives after process terminates
|
|
|
|
cmp [ebx + SOCKET.PID], 0
|
|
jge @f
|
|
|
|
cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSE_WAIT
|
|
jle @f
|
|
|
|
test ecx, ecx
|
|
jz @f
|
|
|
|
;;; Close the socket
|
|
;;; update stats
|
|
|
|
jmp .drop_with_reset
|
|
|
|
@@:
|
|
|
|
;----------------------------------------
|
|
; Remove data beyond right edge of window
|
|
|
|
mov eax, [edx + TCP_segment.SequenceNumber]
|
|
add eax, ecx
|
|
sub eax, [ebx + TCP_SOCKET.RCV_NXT]
|
|
sub ax, [ebx + TCP_SOCKET.RCV_WND]
|
|
|
|
; eax now holds the number of bytes to drop
|
|
|
|
jle .no_excess_data
|
|
|
|
;;; TODO: update stats
|
|
|
|
cmp eax, ecx
|
|
jl .dont_drop_all
|
|
|
|
;;; TODO 700-736
|
|
|
|
.dont_drop_all:
|
|
|
|
.no_excess_data:
|
|
|
|
|
|
;-----------------
|
|
; Record timestamp
|
|
|
|
;;; TODO 737-746
|
|
|
|
;------------------
|
|
; Process RST flags
|
|
|
|
test [edx + TCP_segment.Flags], TH_RST
|
|
jz .rst_skip
|
|
|
|
mov eax, [ebx + TCP_SOCKET.t_state]
|
|
shl eax, 2
|
|
jmp dword [eax + .rst_sw_list]
|
|
|
|
.rst_sw_list:
|
|
dd .rst_skip ;TCB_CLOSED
|
|
dd .rst_skip ;TCB_LISTEN
|
|
dd .rst_skip ;TCB_SYN_SENT
|
|
dd .econnrefused ;TCB_SYN_RECEIVED
|
|
dd .econnreset ;TCB_ESTABLISHED
|
|
dd .econnreset ;TCB_CLOSE_WAIT
|
|
dd .econnreset ;TCB_FIN_WAIT_1
|
|
dd .rst_close ;TCB_CLOSING
|
|
dd .rst_close ;TCB_LAST_ACK
|
|
dd .econnreset ;TCB_FIN_WAIT_2
|
|
dd .rst_close ;TCB_TIMED_WAIT
|
|
|
|
.econnrefused:
|
|
|
|
;;; TODO: debug info
|
|
|
|
jmp .close
|
|
|
|
.econnreset:
|
|
|
|
;;; TODO: debug info
|
|
.close:
|
|
|
|
;;; update stats
|
|
|
|
.rst_close:
|
|
|
|
;;; Close the socket
|
|
jmp .drop
|
|
|
|
.rst_skip:
|
|
|
|
;--------------------------------------
|
|
; handle SYN-full and ACK-less segments
|
|
|
|
test [edx + TCP_segment.Flags], TH_SYN
|
|
jz @f
|
|
|
|
;;; tcp_drop ( ECONNRESET)
|
|
jmp .drop_with_reset
|
|
|
|
test [edx + TCP_segment.Flags], TH_ACK
|
|
jz .drop
|
|
|
|
;----------------
|
|
; Process the ACK
|
|
|
|
cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
|
|
jg .ack_dup
|
|
jl .ack_nodup
|
|
|
|
;;;;;
|
|
|
|
.ack_dup:
|
|
|
|
;;;;
|
|
|
|
.ack_nodup:
|
|
|
|
;;;; 887
|
|
|
|
;-------------------------------------------------
|
|
; If the congestion window was inflated to account
|
|
; for the other side's cached packets, retrace it
|
|
|
|
;;;; 888 - 902
|
|
|
|
|
|
;------------------------------------------
|
|
; RTT measurements and retransmission timer
|
|
|
|
;;;;; 903 - 926
|
|
|
|
mov [ebx + TCP_SOCKET.timer_retransmission], 0
|
|
|
|
mov eax, [ebx + TCP_SOCKET.SND_MAX]
|
|
cmp eax, [edx + TCP_segment.AckNumber]
|
|
je .all_outstanding
|
|
mov [ebx + TCP_SOCKET.timer_retransmission], 120 ;;;; TODO: correct this value
|
|
.all_outstanding:
|
|
|
|
|
|
;-------------------------------------------
|
|
; Open congestion window in response to ACKs
|
|
|
|
;;;;
|
|
|
|
|
|
;------------------------------------------
|
|
; Remove acknowledged data from send buffer
|
|
|
|
;;;; 943 - 956
|
|
|
|
;---------------------------------------
|
|
; Wake up process waiting on send buffer
|
|
|
|
;;;;;
|
|
|
|
mov eax, [ebx + TCP_SOCKET.t_state]
|
|
shl eax, 2
|
|
jmp dword [eax + .ACK_sw_list]
|
|
|
|
.ACK_sw_list:
|
|
dd .step6 ;TCB_CLOSED
|
|
dd .step6 ;TCB_LISTEN
|
|
dd .step6 ;TCB_SYN_SENT
|
|
dd .step6 ;TCB_SYN_RECEIVED
|
|
dd .step6 ;TCB_ESTABLISHED
|
|
dd .step6 ;TCB_CLOSE_WAIT
|
|
dd ._963 ;TCB_FIN_WAIT_1
|
|
dd ._958 ;TCB_CLOSING
|
|
dd ._999 ;TCB_LAST_ACK
|
|
dd .step6 ;TCB_FIN_WAIT_2
|
|
dd ._1010 ;TCB_TIMED_WAIT
|
|
|
|
|
|
._963:
|
|
|
|
|
|
jmp .step6
|
|
|
|
|
|
._958:
|
|
|
|
jmp .step6
|
|
|
|
._999:
|
|
|
|
jmp .step6
|
|
|
|
|
|
._1010:
|
|
|
|
jmp .step6
|
|
|
|
|
|
|
|
align 4
|
|
.step6:
|
|
|
|
DEBUGF 1,"step 6\n"
|
|
|
|
;--------------------------
|
|
; update window information
|
|
|
|
test [edx + TCP_segment.Flags], TH_ACK
|
|
jz .no_window_update
|
|
|
|
mov eax, [ebx + TCP_SOCKET.SND_WL1]
|
|
cmp eax, [edx + TCP_segment.SequenceNumber]
|
|
|
|
;;;; 1021
|
|
|
|
;----------------------------------
|
|
; Keep track of pure window updates
|
|
|
|
test ecx, ecx
|
|
jz @f
|
|
|
|
mov eax, [ebx + TCP_SOCKET.SND_WL2]
|
|
cmp eax, [edx + TCP_segment.AckNumber]
|
|
jne @f
|
|
|
|
;; mov eax, tiwin
|
|
cmp eax, [ebx + TCP_SOCKET.SND_WND]
|
|
jle @f
|
|
|
|
;;; update stats
|
|
|
|
@@:
|
|
|
|
;; mov eax, incoming window
|
|
cmp eax, [ebx + TCP_SOCKET.max_sndwnd]
|
|
jle @f
|
|
mov [ebx + TCP_SOCKET.max_sndwnd], eax
|
|
@@:
|
|
mov [ebx + TCP_SOCKET.SND_WND], eax
|
|
|
|
mov eax, [edx + TCP_segment.SequenceNumber]
|
|
mov [ebx + TCP_SOCKET.SND_WL1], eax
|
|
|
|
mov eax, [edx + TCP_segment.AckNumber]
|
|
mov [ebx + TCP_SOCKET.SND_WL2], eax
|
|
|
|
;;; needoutput = 1
|
|
|
|
.no_window_update:
|
|
|
|
|
|
;-----------------
|
|
; process URG flag
|
|
|
|
test [edx + TCP_segment.Flags], TH_URG
|
|
jz .not_urgent
|
|
|
|
cmp [edx + TCP_segment.UrgentPointer], 0
|
|
jz .not_urgent
|
|
|
|
cmp [ebx + TCP_SOCKET.t_state], TCB_TIMED_WAIT
|
|
je .not_urgent
|
|
|
|
; Ignore bogus urgent offsets
|
|
|
|
;;; 1040-1050
|
|
|
|
movzx eax, [edx + TCP_segment.UrgentPointer]
|
|
add eax, [ebx + SOCKET.SO_RCV.SB_CC]
|
|
cmp eax, SOCKET_MAXDATA
|
|
jle .not_urgent
|
|
|
|
mov [edx + TCP_segment.UrgentPointer], 0
|
|
and [edx + TCP_segment.Flags], not (TH_URG)
|
|
jmp .do_data
|
|
|
|
.not_urgent:
|
|
|
|
;--------------------------------------
|
|
; processing of received urgent pointer
|
|
|
|
;;; 1051-1093
|
|
|
|
align 4
|
|
.do_data:
|
|
|
|
DEBUGF 1,"Do data:\n"
|
|
|
|
; process the data in the segment
|
|
|
|
test [edx + TCP_segment.Flags], TH_FIN
|
|
jz .process_fin
|
|
|
|
test [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1 ;;;;;
|
|
jge .dont_do_data
|
|
|
|
DEBUGF 1,"Processing data in segment\n"
|
|
|
|
;;; NOW, process the data
|
|
|
|
jmp .final_processing
|
|
|
|
|
|
.dont_do_data:
|
|
|
|
|
|
;---------------
|
|
; FIN processing
|
|
|
|
.process_fin:
|
|
|
|
DEBUGF 1,"Processing FIN\n"
|
|
|
|
mov eax, [ebx + TCP_SOCKET.t_state]
|
|
shl eax, 2
|
|
jmp dword [eax + .FIN_sw_list]
|
|
|
|
.FIN_sw_list:
|
|
dd .no_fin ;TCB_CLOSED
|
|
dd .no_fin ;TCB_LISTEN
|
|
dd .no_fin ;TCB_SYN_SENT
|
|
dd ._1131 ;TCB_SYN_RECEIVED
|
|
dd ._1131 ;TCB_ESTABLISHED
|
|
dd .no_fin ;TCB_CLOSE_WAIT
|
|
dd ._1139 ;TCB_FIN_WAIT_1
|
|
dd .no_fin ;TCB_CLOSING
|
|
dd .no_fin ;TCB_LAST_ACK
|
|
dd ._1147 ;TCB_FIN_WAIT_2
|
|
dd ._1156 ;TCB_TIMED_WAIT
|
|
|
|
|
|
|
|
._1131:
|
|
|
|
._1139:
|
|
|
|
._1147:
|
|
|
|
._1156:
|
|
|
|
|
|
.no_fin:
|
|
|
|
;-----------------
|
|
; Final processing
|
|
|
|
.final_processing:
|
|
|
|
DEBUGF 1,"Final processing\n"
|
|
|
|
;;; if debug enabled, output packet
|
|
|
|
;test ;;;needoutput = 1
|
|
;jnz .outputnow
|
|
|
|
test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
|
|
jz .ret
|
|
|
|
.outputnow:
|
|
call TCP_output
|
|
|
|
.ret:
|
|
mov [ebx + SOCKET.lock], 0
|
|
|
|
call kernel_free
|
|
ret 4
|
|
|
|
;------------------------------------------
|
|
; Generate an ACK, droping incoming segment
|
|
|
|
align 4
|
|
.drop_after_ack:
|
|
|
|
DEBUGF 1,"Drop after ACK\n"
|
|
|
|
test [edx + TCP_segment.Flags], TH_RST
|
|
jnz .drop
|
|
|
|
and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
|
|
|
|
call TCP_output
|
|
|
|
mov [ebx + SOCKET.lock], 0
|
|
|
|
call kernel_free
|
|
ret 4
|
|
|
|
|
|
;-------------------------------------------
|
|
; Generate an RST, dropping incoming segment
|
|
|
|
align 4
|
|
.drop_with_reset:
|
|
|
|
DEBUGF 1,"Drop with reset\n"
|
|
|
|
test [edx + TCP_segment.Flags], TH_RST
|
|
jnz .drop
|
|
|
|
;;; if its a multicast/broadcast, also drop
|
|
|
|
test [edx + TCP_segment.Flags], TH_ACK
|
|
jnz .respond_ack
|
|
|
|
test [edx + TCP_segment.Flags], TH_SYN
|
|
jnz .respond_syn
|
|
|
|
mov [ebx + SOCKET.lock], 0
|
|
|
|
call kernel_free
|
|
ret 4
|
|
|
|
.respond_ack:
|
|
|
|
;;;;
|
|
|
|
call TCP_respond
|
|
|
|
jmp .destroy_new_socket
|
|
|
|
|
|
.respond_syn:
|
|
|
|
;;;;
|
|
|
|
call TCP_respond
|
|
|
|
jmp .destroy_new_socket
|
|
|
|
;-----
|
|
; Drop
|
|
|
|
align 4
|
|
.drop:
|
|
|
|
DEBUGF 1,"Dropping packet\n"
|
|
|
|
;;;; If debugging options are enabled, output the packet somwhere
|
|
|
|
.destroy_new_socket:
|
|
|
|
;;;; kill the newly created socket
|
|
|
|
mov [ebx + SOCKET.lock], 0
|
|
|
|
call kernel_free
|
|
ret 4
|
|
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
|
|
|
|
;---------------------
|
|
;
|
|
; TCP_do_options
|
|
;
|
|
;-------------------
|
|
|
|
align 4
|
|
TCP_do_options:
|
|
|
|
DEBUGF 1,"TCP_do_options\n"
|
|
|
|
push eax
|
|
sub eax, 20
|
|
jz .no_options
|
|
|
|
lea esi, [edx + TCP_segment.Data]
|
|
|
|
|
|
;-------------------------------------------
|
|
; Begin the loop by checking for EOL and NOP
|
|
|
|
.loop:
|
|
|
|
cmp byte [esi], TCP_OPT_EOL ; end of option list?
|
|
jz .no_options
|
|
|
|
cmp byte [esi], TCP_OPT_NOP ; nop ?
|
|
;;; cmove edi, 1 ; if so, set option size to 1
|
|
jz .continue ; and continue scanning
|
|
|
|
;------------------
|
|
; We have an option
|
|
|
|
movzx edi, byte [esi + 1] ; get the length of this option in edi
|
|
|
|
|
|
;--------------------------------------
|
|
; Check for Maximum segment size option
|
|
|
|
cmp byte [esi], TCP_OPT_MAXSEG
|
|
jne .no_maxseg
|
|
|
|
cmp edi, 4 ; option length
|
|
jne .continue
|
|
|
|
test [edx + TCP_segment.Flags], TH_SYN
|
|
jz .continue
|
|
|
|
; Now parse the option...
|
|
|
|
jmp .continue
|
|
|
|
.no_maxseg:
|
|
|
|
;------------------------
|
|
; Check for Window option
|
|
|
|
cmp byte [esi], TCP_OPT_WINDOW
|
|
jne .no_window
|
|
|
|
cmp edi, 3 ; option length
|
|
jne .continue
|
|
|
|
test [edx + TCP_segment.Flags], TH_SYN
|
|
jz .continue
|
|
|
|
; ...
|
|
|
|
jmp .continue
|
|
|
|
.no_window:
|
|
|
|
;---------------------------
|
|
; Check for Timestamp option
|
|
|
|
cmp byte [esi], TCP_OPT_TIMESTAMP
|
|
jne .no_timestamp
|
|
|
|
cmp edi, 10 ; option length
|
|
jne .continue
|
|
|
|
; ...
|
|
|
|
|
|
jmp .continue
|
|
|
|
.no_timestamp:
|
|
|
|
;----------------------------------
|
|
; Future options may be placed here
|
|
|
|
|
|
|
|
|
|
;------------------------------
|
|
; Continue scanning for options
|
|
|
|
.continue:
|
|
add esi, edi
|
|
sub eax, edi
|
|
jg .loop
|
|
|
|
.no_options:
|
|
|
|
pop eax
|
|
|
|
ret
|
|
|
|
|
|
|
|
|
|
;---------------------------
|
|
;
|
|
; TCP_pull_out_of_band
|
|
;
|
|
; IN: eax =
|
|
; ebx = socket ptr
|
|
; edx = tcp packet ptr
|
|
;
|
|
; OUT: /
|
|
;
|
|
;---------------------------
|
|
|
|
align 4
|
|
TCP_pull_out_of_band:
|
|
|
|
DEBUGF 1,"TCP_pull_out_of_band\n"
|
|
|
|
;;;; 1282-1305
|
|
|
|
ret
|
|
|
|
|
|
|
|
|
|
|
|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|
|
|
|
|
|
|
|
|
|
|
;-----------------------------------------------------------------
|
|
;
|
|
; TCP_output
|
|
;
|
|
; IN: eax = socket pointer
|
|
;; esi = ptr to data
|
|
;; ecx = number of data bytes
|
|
;
|
|
; OUT: /
|
|
;
|
|
;-----------------------------------------------------------------
|
|
align 4
|
|
TCP_output:
|
|
|
|
DEBUGF 1,"TCP_output, socket: %x\n", eax
|
|
|
|
; We'll detect the length of the data to be transmitted, and flags to be used
|
|
; If there is some data, or any critical controls to send (SYN / RST), then transmit
|
|
; Otherwise, investigate further
|
|
|
|
mov ebx, [eax + TCP_SOCKET.SND_MAX]
|
|
cmp ebx, [eax + TCP_SOCKET.SND_UNA]
|
|
jne .not_idle
|
|
|
|
mov ebx, [eax + TCP_SOCKET.t_idle]
|
|
cmp ebx, [eax + TCP_SOCKET.t_rxtcur]
|
|
jle .not_idle
|
|
|
|
; We have been idle for a while and no ACKS are expected to clock out any data we send..
|
|
; Slow start to get ack "clock" running again.
|
|
|
|
mov ebx, [eax + TCP_SOCKET.t_maxseg]
|
|
mov [eax + TCP_SOCKET.SND_CWND], ebx
|
|
|
|
.not_idle:
|
|
.again:
|
|
mov ebx, [eax + TCP_SOCKET.SND_NXT] ; calculate offset
|
|
sub ebx, [eax + TCP_SOCKET.SND_UNA] ;
|
|
|
|
mov ecx, [eax + TCP_SOCKET.SND_WND] ; determine window
|
|
cmp ecx, [eax + TCP_SOCKET.SND_CWND] ;
|
|
jl @f ;
|
|
mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
|
|
@@: ;
|
|
|
|
call TCP_outflags
|
|
|
|
; If in persist timeout with window of 0, send 1 byte.
|
|
; Otherwise, if window is small but nonzero, and timer expired,
|
|
; we will send what we can and go to transmit state
|
|
|
|
test [eax + TCP_SOCKET.t_force], -1
|
|
jz .no_persist_timeout
|
|
|
|
test ecx, ecx
|
|
jnz .no_zero_window
|
|
|
|
cmp ebx, [eax + SOCKET.SO_SND.SB_CC]
|
|
jge @f
|
|
|
|
and dl, not (TH_FIN) ; clear the FIN flag ??? how can it be set before?
|
|
|
|
@@:
|
|
inc ecx
|
|
jmp .no_persist_timeout
|
|
|
|
.no_zero_window:
|
|
|
|
;;; mov [eax + TCP_SOCKET.t_timer....TCPT_PERSIST], 0
|
|
mov [eax + TCP_SOCKET.t_rxtshift], 0
|
|
|
|
.no_persist_timeout:
|
|
|
|
;;;106
|
|
|
|
mov esi, [eax + SOCKET.SO_SND.SB_CC]
|
|
cmp esi, ecx
|
|
jl @f
|
|
mov esi, ecx
|
|
@@:
|
|
sub esi, ebx
|
|
|
|
cmp esi, -1
|
|
jne .not_minus_one
|
|
|
|
; If FIN has been set, but not ACKed, and we havent been called to retransmit,
|
|
; len (esi) will be -1
|
|
; Otherwise, window shrank after we sent into it.
|
|
; If window shrank to 0, cancel pending retransmit and pull SND_NXT back to (closed) window
|
|
; We will enter persist state below.
|
|
; If window didn't close completely, just wait for an ACK
|
|
|
|
xor esi, esi
|
|
|
|
test ecx, ecx
|
|
jnz @f
|
|
|
|
;;; mov [eax + TCP_SOCKET.t_timer..TCPT_REXMT], 0
|
|
|
|
push [eax + TCP_SOCKET.SND_UNA]
|
|
pop [eax + TCP_SOCKET.SND_NXT]
|
|
@@:
|
|
|
|
.not_minus_one:
|
|
|
|
;;; 124
|
|
|
|
cmp esi, [eax + TCP_SOCKET.t_maxseg]
|
|
jle @f
|
|
|
|
mov esi, [eax + TCP_SOCKET.t_maxseg]
|
|
;sendalot = 1
|
|
|
|
@@:
|
|
|
|
;;; 128
|
|
|
|
mov edi, [eax + TCP_SOCKET.SND_NXT]
|
|
add edi, esi ; len
|
|
sub edi, [eax + TCP_SOCKET.SND_UNA]
|
|
add edi, [eax + SOCKET.SO_SND.SB_CC]
|
|
cmp edi, 0
|
|
jle @f
|
|
|
|
and dl, not (TH_FIN) ; clear the FIN flag
|
|
|
|
@@:
|
|
|
|
|
|
;;;; 130 TODO: set window (ecx) to space in send buffer
|
|
|
|
|
|
;------------------------------
|
|
; Sender silly window avoidance
|
|
|
|
test esi, esi
|
|
jz .zero_length
|
|
|
|
|
|
cmp esi, [eax + TCP_SOCKET.t_maxseg]
|
|
je .send
|
|
|
|
;;; TODO: 144-145
|
|
|
|
test [eax + TCP_SOCKET.t_force], -1
|
|
jnz .send
|
|
|
|
;;; TODO: 149..152
|
|
|
|
.zero_length:
|
|
|
|
|
|
;----------------------------------------
|
|
; Check if a window update should be sent
|
|
|
|
cmp ecx, 0 ; window
|
|
jle .no_window
|
|
|
|
;;; TODO 154-172
|
|
|
|
.no_window:
|
|
|
|
;--------------------------
|
|
; Should a segment be sent?
|
|
|
|
test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
|
|
jnz .send
|
|
|
|
test dl, TH_SYN + TH_RST
|
|
jnz .send
|
|
|
|
mov eax, [ebx + TCP_SOCKET.SND_UP]
|
|
cmp eax, [ebx + TCP_SOCKET.SND_UNA]
|
|
jg .send
|
|
|
|
test dl, TH_FIN
|
|
jz .enter_persist
|
|
|
|
test [ebx + TCP_SOCKET.t_flags], TF_SENTFIN
|
|
jnz .send
|
|
|
|
mov eax, [ebx + TCP_SOCKET.SND_NXT]
|
|
cmp eax, [ebx + TCP_SOCKET.SND_UNA]
|
|
je .send
|
|
|
|
;--------------------
|
|
; Enter persist state
|
|
|
|
.enter_persist:
|
|
|
|
DEBUGF 1,"Entering persist state\n"
|
|
|
|
|
|
|
|
;--------------------------------------
|
|
; No reason to send a segment, just ret
|
|
|
|
DEBUGF 1,"No reason to send a segment\n"
|
|
|
|
ret
|
|
|
|
|
|
|
|
|
|
|
|
;-----------------------------------------------
|
|
;
|
|
; Send a segment
|
|
;
|
|
; ebx = socket pointer
|
|
; dl = flags
|
|
;
|
|
;-----------------------------------------------
|
|
|
|
.send:
|
|
|
|
DEBUGF 1,"Preparing to send a segment\n"
|
|
|
|
xor edi, edi ; edi will contain the number of header option bytes
|
|
|
|
;------------------------------------
|
|
; Send options with first SYN segment
|
|
|
|
test dl, TH_SYN
|
|
jz .no_options
|
|
|
|
mov eax, [ebx + TCP_SOCKET.ISS]
|
|
mov [ebx + TCP_SOCKET.SND_NXT], eax
|
|
|
|
test [ebx + TCP_SOCKET.t_flags], TF_NOOPT
|
|
jnz .no_options
|
|
|
|
mov eax, TCP_OPT_MAXSEG shl 24 + 4 shl 16
|
|
mov ax, 1280 ;;;;;;
|
|
bswap eax
|
|
push eax
|
|
|
|
mov di, 4
|
|
|
|
test [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
|
|
jz .no_syn
|
|
|
|
test dl, TH_ACK
|
|
jnz .scale_opt
|
|
|
|
test [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
|
|
jz .no_syn
|
|
|
|
.scale_opt:
|
|
|
|
mov eax, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP
|
|
mov ah, byte [ebx + TCP_SOCKET.request_r_scale]
|
|
bswap eax
|
|
push eax
|
|
|
|
add di, 4
|
|
|
|
.no_syn:
|
|
|
|
;------------------------------------
|
|
; Make the timestamp option if needed
|
|
|
|
test [ebx + TCP_SOCKET.t_flags], TF_REQ_TSTMP
|
|
jz .no_timestamp
|
|
|
|
test dl, TH_RST
|
|
jnz .no_timestamp
|
|
|
|
test dl, TH_ACK
|
|
jz .timestamp
|
|
|
|
test [ebx + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
|
|
jz .no_timestamp
|
|
|
|
.timestamp:
|
|
|
|
DEBUGF 1,"Creating a timestamp\n"
|
|
|
|
push dword (TCP_OPT_TIMESTAMP shl 8 + 10 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24)
|
|
pushw 0
|
|
mov eax, [timer_ticks]
|
|
bswap eax
|
|
push eax
|
|
|
|
add di, 10
|
|
|
|
.no_timestamp:
|
|
|
|
;; TODO: check if we dont exceed the max segment size
|
|
|
|
.no_options:
|
|
add edi, TCP_segment.Data
|
|
|
|
;-----------------------------------
|
|
; Check if we have some data to send
|
|
|
|
;;; mov ecx, [huppeldepup]
|
|
|
|
test ecx, ecx
|
|
jz .no_data
|
|
|
|
;;; 278-316
|
|
|
|
jmp .header
|
|
|
|
.no_data:
|
|
|
|
;;; 317-338
|
|
|
|
|
|
;----------
|
|
|
|
push di dx ebx
|
|
|
|
add ecx, edi ; total TCP segment size
|
|
|
|
mov eax, [ebx + IP_SOCKET.RemoteIP]
|
|
mov ebx, [ebx + IP_SOCKET.LocalIP]
|
|
mov di , IP_PROTO_TCP
|
|
call IPv4_create_packet
|
|
|
|
;;;; jz .fail
|
|
|
|
push edx eax
|
|
call [ebx + NET_DEVICE.transmit]
|
|
ret
|
|
|
|
;----------------
|
|
|
|
|
|
;-------------------------------
|
|
; Now, create the 20-byte header
|
|
|
|
.header:
|
|
|
|
;-----------------------
|
|
; Fill in the TCP header
|
|
pop esi
|
|
|
|
push [esi + TCP_SOCKET.SND_NXT]
|
|
rol word [esp], 8
|
|
rol dword [esp], 16
|
|
pop [edi + TCP_segment.SequenceNumber]
|
|
|
|
push [esi + TCP_SOCKET.RCV_NXT]
|
|
rol word [esp], 8
|
|
rol dword [esp], 16
|
|
pop [edi + TCP_segment.AckNumber]
|
|
|
|
push [esi + TCP_SOCKET.LocalPort]
|
|
rol word [esp], 8
|
|
pop [edi + TCP_segment.SourcePort]
|
|
|
|
push [esi + TCP_SOCKET.RemotePort]
|
|
rol word [esp], 8
|
|
pop [edi + TCP_segment.DestinationPort]
|
|
|
|
|
|
mov [edi + TCP_segment.Window], 0x0005
|
|
; 1280 bytes
|
|
mov [edi + TCP_segment.UrgentPointer], 0
|
|
|
|
mov [edi + TCP_segment.DataOffset], 0x50
|
|
|
|
mov [edi + TCP_segment.Flags], cl
|
|
|
|
mov [edi + TCP_segment.Checksum], 0
|
|
|
|
;-----
|
|
|
|
|
|
;--------------
|
|
; Copy the data
|
|
|
|
pop esi
|
|
push edi
|
|
add edi, TCP_segment.Data ;;
|
|
sub ecx, TCP_segment.Data ;;;
|
|
|
|
shr ecx, 1
|
|
jnc .nb
|
|
movsb
|
|
.nb:
|
|
shr ecx, 1
|
|
jnc .nw
|
|
movsw
|
|
.nw:
|
|
test ecx, ecx
|
|
jz .nd
|
|
rep movsd
|
|
.nd:
|
|
pop edi
|
|
|
|
;--------------------
|
|
; Create the checksum
|
|
|
|
push [ebx + IP_SOCKET.LocalIP]
|
|
push [ebx + IP_SOCKET.RemoteIP]
|
|
call TCP_checksum
|
|
|
|
;----------------
|
|
; Send the packet
|
|
|
|
;;;;;
|
|
|
|
|
|
DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
|
|
call [ebx + NET_DEVICE.transmit]
|
|
ret
|
|
|
|
;-------------------------
|
|
;
|
|
; TCP_outflags
|
|
;
|
|
; IN: eax = socket ptr
|
|
;
|
|
; OUT: edx = flags
|
|
;
|
|
;-------------------------
|
|
align 4
|
|
TCP_outflags:
|
|
|
|
mov edx, [eax + TCP_SOCKET.t_state]
|
|
movzx edx, byte [edx + .flaglist]
|
|
|
|
DEBUGF 1,"TCP_outflags, socket: %x, flags: %x\n", eax, dl
|
|
|
|
ret
|
|
|
|
.flaglist:
|
|
|
|
db TH_RST + TH_ACK ; TCB_CLOSED
|
|
db 0 ; TCB_LISTEN
|
|
db TH_SYN ; TCB_SYN_SENT
|
|
db TH_SYN + TH_ACK ; TCB_SYN_RECEIVED
|
|
db TH_ACK ; TCB_ESTABLISHED
|
|
db TH_ACK ; TCB_CLOSE_WAIT
|
|
db TH_SYN + TH_ACK ; TCB_FIN_WAIT_1
|
|
db TH_SYN + TH_ACK ; TCB_CLOSING
|
|
db TH_SYN + TH_ACK ; TCB_LAST_ACK
|
|
db TH_ACK ; TCB_FIN_WAIT_2
|
|
db TH_ACK ; TCB_TIMED_WAIT
|
|
|
|
|
|
;-------------------------
|
|
;
|
|
; TCP_drop
|
|
;
|
|
; IN: eax = socket ptr
|
|
;
|
|
; OUT: /
|
|
;
|
|
;-------------------------
|
|
align 4
|
|
TCP_drop:
|
|
|
|
DEBUGF 1,"TCP_drop\n"
|
|
|
|
; cmp [eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
|
|
; jl .no_syn_received
|
|
|
|
mov [eax + TCP_SOCKET.t_state], TCB_CLOSED
|
|
|
|
call TCP_output
|
|
|
|
; .no_syn_received:
|
|
|
|
ret
|
|
|
|
|
|
|
|
|
|
|
|
;---------------------------------------
|
|
;
|
|
; TCP_ack
|
|
;
|
|
; The easy way to send an ACK/RST/keepalive segment
|
|
;
|
|
; IN: eax = socket ptr
|
|
; -or-
|
|
; edx = packet ptr (eax must be 0)
|
|
; cl = flags
|
|
;
|
|
; OUT: /
|
|
;
|
|
;---------------------------------------
|
|
align 4
|
|
TCP_respond:
|
|
|
|
DEBUGF 1,"TCP_respond\n"
|
|
|
|
;---------------------
|
|
; Create the IP packet
|
|
|
|
push cx eax edx
|
|
mov ebx, [eax + IP_SOCKET.LocalIP]
|
|
mov eax, [eax + IP_SOCKET.RemoteIP]
|
|
mov ecx, TCP_segment.Data
|
|
mov di , IP_PROTO_TCP
|
|
call IPv4_create_packet
|
|
test edi, edi
|
|
jz .error
|
|
|
|
;---------------------------
|
|
; Now fill in the TCP header
|
|
|
|
pop ecx
|
|
pop esi
|
|
|
|
test esi, esi
|
|
; jz
|
|
|
|
|
|
push edx eax
|
|
|
|
push dword .checksum
|
|
je .use_segment
|
|
jmp .use_socket
|
|
|
|
;---------------------
|
|
; Fill in the checksum
|
|
|
|
.checksum:
|
|
|
|
push [esi + IP_SOCKET.LocalIP]
|
|
push [esi + IP_SOCKET.RemoteIP]
|
|
lea esi, [edi - 20]
|
|
xor ecx, ecx
|
|
call TCP_checksum
|
|
|
|
;--------------------
|
|
; And send the segment
|
|
|
|
call [ebx + NET_DEVICE.transmit]
|
|
ret
|
|
|
|
.error:
|
|
DEBUGF 1,"TCP_ack failed\n"
|
|
add esp, 4
|
|
|
|
ret
|
|
|
|
;---------------------------------------------------
|
|
; Fill in the TCP header by using a received segment
|
|
|
|
.use_segment:
|
|
|
|
mov ax, [esi + TCP_segment.DestinationPort]
|
|
rol ax, 8
|
|
stosw
|
|
mov ax, [esi + TCP_segment.SourcePort]
|
|
rol ax, 8
|
|
stosw
|
|
mov eax, [esi + TCP_segment.AckNumber]
|
|
bswap eax
|
|
stosd
|
|
xor eax, eax
|
|
stosd
|
|
mov al, 0x50 ; Dataoffset: 20 bytes
|
|
stosb
|
|
mov al, cl
|
|
stosb
|
|
mov ax, 1280
|
|
rol ax, 8
|
|
stosw ; window
|
|
xor eax, eax
|
|
stosd ; checksum + urgentpointer
|
|
|
|
ret
|
|
|
|
|
|
;-----------------------------------------------
|
|
; Fill in the TCP header by using the socket ptr
|
|
|
|
.use_socket:
|
|
|
|
mov ax, [esi + TCP_SOCKET.LocalPort]
|
|
rol ax, 8
|
|
stosw
|
|
mov ax, [esi + TCP_SOCKET.RemotePort]
|
|
rol ax, 8
|
|
stosw
|
|
mov eax, [esi + TCP_SOCKET.SND_NXT]
|
|
bswap eax
|
|
stosd
|
|
mov eax, [esi + TCP_SOCKET.RCV_NXT]
|
|
bswap eax
|
|
stosd
|
|
mov al, 0x50 ; Dataoffset: 20 bytes
|
|
stosb
|
|
mov al, cl
|
|
stosb
|
|
mov ax, [esi + TCP_SOCKET.RCV_WND]
|
|
rol ax, 8
|
|
stosw ; window
|
|
xor eax, eax
|
|
stosd ; checksum + urgentpointer
|
|
|
|
ret
|
|
|
|
|
|
|
|
;-----------------------------------------------------------------
|
|
;
|
|
; TCP_checksum
|
|
;
|
|
; This is the fast procedure to create or check a UDP header
|
|
; - To create a new checksum, the checksum field must be set to 0 before computation
|
|
; - To check an existing checksum, leave the checksum as is,
|
|
; and it will be 0 after this procedure, if it was correct
|
|
;
|
|
; IN: push source ip
|
|
; push dest ip
|
|
;
|
|
; esi = packet ptr
|
|
;
|
|
; OUT: checksum is filled in in packet! (but also in dx)
|
|
;
|
|
;-----------------------------------------------------------------
|
|
align 4
|
|
TCP_checksum:
|
|
|
|
;-------------
|
|
; Pseudoheader
|
|
|
|
; protocol type
|
|
mov edx, IP_PROTO_TCP ; NO shl 8 here ! (it took me ages to figure this one out)
|
|
|
|
; source address
|
|
add dl, [esp+1+4]
|
|
adc dh, [esp+0+4]
|
|
adc dl, [esp+3+4]
|
|
adc dh, [esp+2+4]
|
|
|
|
; destination address
|
|
adc dl, [esp+1+8]
|
|
adc dh, [esp+0+8]
|
|
adc dl, [esp+3+8]
|
|
adc dh, [esp+2+8]
|
|
|
|
; size
|
|
adc dl, cl
|
|
adc dh, ch
|
|
|
|
;---------------------
|
|
; Real header and data
|
|
|
|
push esi
|
|
call checksum_1
|
|
call checksum_2
|
|
pop esi
|
|
|
|
neg [esi+UDP_Packet.Checksum] ; zero will stay zero so we just get the checksum
|
|
add [esi+UDP_Packet.Checksum], dx ; , else we will get (new checksum - old checksum) in the end, wich should be 0 :)
|
|
|
|
ret 8 ; Remove the IPs from stack
|
|
|
|
|
|
|
|
|
|
;---------------------------------------------------------------------------
|
|
;
|
|
; TCP_API
|
|
;
|
|
; This function is called by system function 75
|
|
;
|
|
; IN: subfunction number in bl
|
|
; device number in bh
|
|
; ecx, edx, .. depends on subfunction
|
|
;
|
|
; OUT:
|
|
;
|
|
;---------------------------------------------------------------------------
|
|
align 4
|
|
TCP_API:
|
|
|
|
movzx eax, bh
|
|
shl eax, 2
|
|
|
|
test bl, bl
|
|
jz .packets_tx ; 0
|
|
dec bl
|
|
jz .packets_rx ; 1
|
|
|
|
.error:
|
|
mov eax, -1
|
|
ret
|
|
|
|
.packets_tx:
|
|
add eax, TCP_segments_tx
|
|
mov eax, [eax]
|
|
ret
|
|
|
|
.packets_rx:
|
|
add eax, TCP_segments_rx
|
|
mov eax, [eax]
|
|
ret
|