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  → /kernel/branches/net/network/tcp.inc @ 1529

  → /kernel/branches/net/network/tcp.inc @ 1528

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Regard whitespace Rev 1529 → Rev 1528

/kernel/branches/net/network/tcp.inc
73,9 → 73,6
TCP_max_rxtshift equ 12 ; max retransmissions waiting for ACK
TCP_max_keepcnt equ 8 ; max keepalive probes
;
TCP_max_winshift equ 14
TCP_max_win equ 65535
struct TCP_segment
.SourcePort dw ?
120,8 → 117,12
;
; This function resets all TCP variables
;
; IN: /
; OUT: /
;
;-----------------------------------------------------------------
macro TCP_init {
align 4
TCP_init:
xor eax, eax
mov edi, TCP_segments_tx
128,10 → 129,9
mov ecx, (6*IP_MAX_INTERFACES)
rep stosd
pseudo_random eax
mov [TCP_sequence_num], eax
mov [TCP_sequence_num], 1
}
ret
;----------------------
138,11 → 138,9
;
;
;----------------------
macro TCP_timer_160ms {
align 4
TCP_timer_160ms:
local .loop
local .exit
mov eax, net_sockets
.loop:
mov eax, [eax + SOCKET.NextPtr]
158,7 → 156,7
DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax
push eax
call TCP_respond_socket
call TCP_respond
pop eax
jmp .loop
165,7 → 163,7
.exit:
}
ret
;-----------------------------------------------------------------
172,11 → 170,9
;
;
;-----------------------------------------------------------------
macro TCP_timer_640ms {
align 4
TCP_timer_640ms:
local .loop
local .exit
; Update TCP sequence number
add [TCP_sequence_num], 64000
194,7 → 190,6
cmp [eax + SOCKET.Type], IP_PROTO_TCP
jne .loop
inc [eax + TCP_SOCKET.t_idle]
dec [eax + TCP_SOCKET.timer_retransmission]
jnz .check_more2
226,47 → 221,9
jmp .loop
.exit:
}
ret
macro TCP_checksum IP1, IP2 {
;-------------
; Pseudoheader
; protocol type
mov edx, IP_PROTO_TCP
; source address
add dl, byte [IP1+1+4]
adc dh, byte [IP1+0+4]
adc dl, byte [IP1+3+4]
adc dh, byte [IP1+2+4]
; destination address
adc dl, byte [IP2+1+8]
adc dh, byte [IP2+0+8]
adc dl, byte [IP2+3+8]
adc dh, byte [IP2+2+8]
; size
adc dl, cl
adc dh, ch
;---------------------
; Real header and data
push esi
call checksum_1
call checksum_2
pop esi
} ; returns in dx only
;-----------------------------------------------------------------
;
; TCP_input:
286,7 → 243,8
align 4
TCP_input:
DEBUGF 1,"TCP_input size=%u\n", ecx
DEBUGF 1,"TCP_input\n"
; 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.
movzx eax, [edx + TCP_segment.DataOffset]
293,39 → 251,39
and eax, 0xf0
shr al, 2
DEBUGF 1,"headersize=%u\n", eax
DEBUGF 1,"data offset: %u\n", eax
cmp eax, 20
jl .drop
cmp eax, ecx
jg .drop
;-------------------------------
; Now, re-calculate the checksum
push eax ecx edx
pushw [edx + TCP_segment.Checksum]
mov [edx + TCP_segment.Checksum], 0
push esi edi
push eax edx ebx
push edi
push esi
mov esi, edx
TCP_checksum
pop esi edi ; yes, swap them (we dont need dest addr)
pop cx ; previous checksum
cmp cx, dx
pop edx ecx esi
call TCP_checksum ; this destroys edx, ecx and esi (but not edi! :)
pop ebx edx eax
cmp [edx + TCP_segment.Checksum], 0
jnz .drop
DEBUGF 1,"Checksum is correct\n"
sub ecx, esi ; update packet size
jl .drop
;-----------------------------------------------------------------------------------------
; Check if this packet has a timestamp option (We do it here so we can process it quickly)
cmp esi, 20 + 12 ; Timestamp option is 12 bytes
cmp eax, 20 + 12 ; Timestamp option is 12 bytes
jl .no_timestamp
je .is_ok
cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list
cmp byte [edx + TCP_segment.Data + 12], 0 ; end of option list
jne .no_timestamp
.is_ok:
337,9 → 295,11
DEBUGF 1,"timestamp ok\n"
; TODO: Parse the option
; TODO: Parse the options
; TODO: Set a Bit in the TCP to tell all options are parsed
ret
.no_timestamp:
;-------------------------------------------
350,8 → 310,6
ntohlw [edx + TCP_segment.Window]
ntohlw [edx + TCP_segment.UrgentPointer]
ntohlw [edx + TCP_segment.SourcePort]
ntohlw [edx + TCP_segment.DestinationPort]
;------------------------------------------------------------
; Next thing to do is find the TCB (thus, the socket pointer)
375,7 → 333,7
jne .socket_loop
mov eax, [ebx + IP_SOCKET.RemoteIP]
cmp eax, edi ; sender IP
cmp eax, esi
je @f
test eax, eax
jnz .socket_loop
394,126 → 352,72
;----------------------------
; Check if socket isnt closed
cmp [ebx + TCP_SOCKET.t_state], TCB_CLOSED
cmp [TCP_SOCKET.t_state], TCB_CLOSED
je .drop
;----------------
; Lock the socket
;; add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
;; call wait_mutex
;; sub ebx, SOCKET.lock
add ebx, SOCKET.lock ; TODO: figure out if we should lock now already
call wait_mutex
sub ebx, SOCKET.lock
DEBUGF 1,"Socket locked\n"
;---------------------------------------
; unscale the window into a 32 bit value ;;;;;;
;----------------------------------------------------------------------------------------
; unscale the window into a 32 bit value (notice that SND_SCALE must be initialised to 0)
movzx eax, [edx + TCP_segment.Window]
xchg al, ah
movzx eax, [edx + TCP_segment.Window]
push cx
test [edx + TCP_segment.Flags], TH_SYN
jnz .no_syn
mov cl, [ebx + TCP_SOCKET.SND_SCALE]
shl eax, cl
pop cx
;;;; do something with eax
.no_syn:
;-----------------------------------
; Is this socket a listening socket?
; test [ebx + SOCKET.options], SO_ACCEPTCON
; jnz .listening_socket ;;;;; TODO
; If so, create a new socket
;-------------------------------------
; Reset idle timer and keepalive timer
test [ebx + SOCKET.options], SO_ACCEPTCON
jz .no_accept_conn
mov [ebx + TCP_SOCKET.t_idle], 0
mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
;--------------------
; Process TCP options
; TODO: create a new socket
cmp esi, 20 ; esi is headersize
je .no_options
DEBUGF 1,"Segment has options\n"
.no_accept_conn:
test [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state
jz .no_options
;----------------------------
; Compute window scale factor
lea edi, [edx + TCP_segment.Data]
lea eax, [edx + esi]
.opt_loop:
cmp edi, eax
jge .no_options
; TODO
cmp byte [edi], TCP_OPT_EOL ; end of option list?
jz .no_options
cmp byte [edi], TCP_OPT_NOP ; nop ?
jz .opt_nop
;-------------------------------------
; Reset idle timer and keepalive timer
cmp byte [edi], TCP_OPT_MAXSEG
je .opt_maxseg
;;;; TODO: idle timer?
cmp byte [edi], TCP_OPT_WINDOW
je .opt_window
mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
cmp byte [edi], TCP_OPT_TIMESTAMP
je .opt_timestamp
;-----------------------------------------
; Process TCP options if not in LISTEN state
jmp .no_options ; If we reach here, some unknown options were received, skip them all!
test [ebx + TCP_SOCKET.t_state], TCB_LISTEN
jz .dont_do_options
.opt_nop:
inc edi
jmp .opt_loop
call TCP_do_options
.opt_maxseg:
cmp byte [edi+1], 4
jne .no_options ; error occured, ignore all options!
.dont_do_options:
test [edx + TCP_segment.Flags], TH_SYN
jz @f
DEBUGF 1,"Got maxseg option"
;;;;;
@@:
add edi, 4
jmp .opt_loop
.opt_window:
cmp byte [edi+1], 3
jne .no_options
test [edx + TCP_segment.Flags], TH_SYN
jz @f
DEBUGF 1,"Got window option"
;;;;;
@@:
add edi, 3
jmp .opt_loop
.opt_timestamp:
cmp byte [edi+1], 10
jne .no_options
DEBUGF 1,"Got timestamp option"
;;;;;
add edi, 10
jmp .opt_loop
.no_options:
;-----------------------------------------------------------------------
; Time to do some header prediction (Original Principle by Van Jacobson)
; There are two common cases for an uni-directional data transfer.
;
; General rule: the packets has no control flags, is in-sequence,
526,13 → 430,13
; - If the length is not 0 and the ACK didn't move, we're the receiver side of the transfer.
; If the packets are in order (data queue is empty), add the data to the socket buffer and request a delayed ACK
cmp [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
cmp [TCP_SOCKET.t_state], TCB_ESTABLISHED
jnz .not_uni_xfer
test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
test [TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG
jnz .not_uni_xfer
test [edx + TCP_segment.Flags], TH_ACK
test [TCP_segment.Flags], TH_ACK
jz .not_uni_xfer
mov eax, [edx + TCP_segment.SequenceNumber]
539,7 → 443,7
cmp eax, [ebx + TCP_SOCKET.RCV_NXT]
jne .not_uni_xfer
movzx eax, [edx + TCP_segment.Window] ;;;;; (should use pre-calculated value isntead: todo: figure out where to store it)
movzx eax, [edx + TCP_segment.Window] ;;;;;
cmp eax, [ebx + TCP_SOCKET.SND_WND]
jne .not_uni_xfer
547,30 → 451,47
cmp eax, [ebx + TCP_SOCKET.SND_MAX]
jne .not_uni_xfer
;-------------------------------------------------------------------------------
; If last ACK falls within this segment's sequence number, record the timestamp.
; TODO: check if it has a timestamp
;---------------------------------------
; check if we are sender in the uni-xfer
; If the following 4 conditions are all true, this segment is a pure ACK.
;
; - The segment contains no data.
test ecx, ecx
; - The segment contains no data (ti_len is 0).
movzx eax, [edx + TCP_segment.DataOffset]
and eax, 11110000b
shr eax, 2
sub ecx, eax
jnz .not_sender
; - The congestion window is greater than or equal to the current send window.
; - The acknowledgment field in the segment (ti_ack) is greater than the largest unacknowledged sequence number (snd_una).
; 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.
mov eax, [edx + TCP_segment.AckNumber]
cmp eax, [ebx + TCP_SOCKET.SND_UNA]
jle .not_uni_xfer
; - The acknowledgment field in the segment (ti_ack) is less than or equal to the maximum sequence number sent (snd_max).
; mov eax, [edx + TCP_segment.Ack]
cmp eax, [ebx + TCP_SOCKET.SND_MAX]
jg .not_uni_xfer
; - The congestion window (snd_cwnd) is greater than or equal to the current send window (snd_wnd).
; 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.
mov eax, [ebx + TCP_SOCKET.SND_CWND]
cmp eax, [ebx + TCP_SOCKET.SND_WND]
jl .not_uni_xfer
; - The acknowledgment field in the segment is less than or equal to the maximum sequence number sent.
mov ecx, [edx + TCP_segment.AckNumber]
cmp ecx, [ebx + TCP_SOCKET.SND_MAX]
jg .not_uni_xfer
; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number.
sub ecx, [ebx + TCP_SOCKET.SND_UNA]
jle .not_uni_xfer
DEBUGF 1,"Header prediction: we are sender\n"
;---------------------------------
579,11 → 500,7
; Update RTT estimators
; Delete acknowledged bytes from send buffer
; notice how ecx already holds number of bytes ack-ed
lea eax, [ebx + snd]
call SOCKET_ring_free
; Stop retransmit timer
mov [ebx + TCP_SOCKET.timer_ack], 0
596,19 → 513,27
jmp .drop
;-------------------------------------------------
; maybe we are the receiver in the uni-xfer then..
.not_sender:
; - The amount of data in the segment is greater than 0 (data count is in ecx)
; The amount of data in the segment (ti_len) is greater than 0 (data count is in ecx)
; - The acknowledgment field equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
; The acknowledgment field (ti_ack) equals the largest unacknowledged sequence number. This means no data is acknowledged by this segment.
mov eax, [edx + TCP_segment.AckNumber]
cmp eax, [ebx + TCP_SOCKET.SND_UNA]
jne .not_uni_xfer
; - The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp). ;;;;;;;
; The reassembly list of out-of-order segments for the connection is empty (seg_next equals tp).
;;;;
jnz .not_uni_xfer
; There is room in the receive buffer for the data in the segment.
;;;;
jnz .not_uni_xfer
;-------------------------------------
616,41 → 541,63
DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
add esi, edx
lea eax, [ebx + rcv]
call SOCKET_ring_add ; Add the data to the socket buffer
; The next expected receive sequence number (rcv_nxt) is incremented by the number of bytes of data.
add [ebx + TCP_SOCKET.RCV_NXT], ecx ; Update sequence number with number of bytes we have copied
or [ebx + TCP_SOCKET.t_flags], TF_DELACK ; Set delayed ack flag
add [ebx + TCP_SOCKET.RCV_NXT], ecx
; Add the data to the socket buffer
mov eax, ebx
;;; mov...
call SOCKET_input
; The delayed-ACK flag is set and the input processing is complete.
jmp .drop
;----------------------------------------------------
; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !!
; Header prediction failed, doing it the slow way..
.not_uni_xfer:
DEBUGF 1,"Header prediction failed\n"
;------------------------
; 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 [ebx + TCP_SOCKET.t_state], TCB_LISTEN
cmp [eax + TCP_SOCKET.t_state], TCB_LISTEN
je .LISTEN
cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT
cmp [eax + TCP_SOCKET.t_state], TCB_SYN_SENT
je .SYN_SENT
;--------------------------------------------
; Protection Against Wrapped Sequence Numbers
; First, check timestamp if present
;;;; TODO
661,9 → 608,6
jmp .trim_then_step6
;-------------
; Passive Open
align 4
.LISTEN:
678,37 → 622,47
test [edx + TCP_segment.Flags], TH_SYN
jz .drop
; TODO: find sender ip address somewhere!
; TODO: check if it's a broadcast or multicast, and drop if so
call SOCKET_fork
jz .drop ; if we could not open a new connection, drop segment (;;;; should we send RST too?)
;;; 28.6
;-----------------------
; Fill in some variables
; create a new socket and fill in the nescessary variables
add [TCP_sequence_num], 64000
;; Exit if backlog queue is full
; mov ax, [ebx + TCP_SOCKET.backlog_cur]
; cmp ax, [ebx + TCP_SOCKET.backlog]
; jae .exit
push [edx + TCP_segment.SourcePort]
pop [eax + TCP_SOCKET.RemotePort]
; Allocate new socket
call SOCKET_alloc
;;; jz .fail
push [edx + TCP_segment.SequenceNumber]
pop [eax + TCP_SOCKET.IRS]
; 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 [eax + TCP_SOCKET.ISS]
pop [eax + TCP_SOCKET.SND_NXT]
;; 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 + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
mov [eax + TCP_SOCKET.t_flags], TF_ACKNOW
mov [eax + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
mov [eax + IP_SOCKET.RemoteIP], esi ; IP source address
mov ebx, eax
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
;------------
; Active Open
align 4
.SYN_SENT:
722,13 → 676,12
cmp eax, [ebx + TCP_SOCKET.ISS]
jle .drop_with_reset
DEBUGF 1,"snd_max = %x\n", [ebx + TCP_SOCKET.SND_MAX] ;;; TODO: set this, but where?
; mov eax, [edx + TCP_segment.AckNumber]
;; cmp eax, [ebx + TCP_SOCKET.SND_MAX]
;; jg .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
743,41 → 696,24
test [edx + TCP_segment.Flags], TH_SYN
jz .drop
; at this point, segment seems to be valid
; now, process received SYN in response to an active open
test [edx + TCP_segment.Flags], TH_ACK
jz .no_syn_ack
jz @f
; now, process received SYN in response to an active open
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
@@:
.no_syn_ack:
mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
mov [ebx + TCP_SOCKET.timer_retransmission], 0
mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission
mov eax, [edx + TCP_segment.SequenceNumber]
mov [ebx + TCP_SOCKET.IRS], eax
push [edx + TCP_segment.SequenceNumber]
pop [ebx + TCP_SOCKET.IRS]
;;; TODO: tcp_rcvseqinit
mov [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
mov eax, [ebx + TCP_SOCKET.SND_UNA]
cmp eax, [ebx + TCP_SOCKET.ISS]
jle .simultaneous_open
test [edx + TCP_segment.Flags], TH_ACK
jz .simultaneous_open
DEBUGF 1,"TCP: active open\n"
; TODO: update stats
; TODO: set socket state to connected
mov [ebx + TCP_SOCKET.t_state], TCB_ESTABLISHED
785,11 → 721,9
; TODO: check if we should scale the connection (567-572)
; TODO: update RTT estimators
jmp .trimthenstep6
.simultaneous_open:
@@:
DEBUGF 1,"TCP: simultaneous open\n"
; We have received a syn but no ACK, so we are having a simultaneous open..
mov [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED
810,15 → 744,16
; TODO...
@@:
;;;;;
jmp .step6
;;; jmp .step6
align 4
.trim_then_step6:
DEBUGF 1,"Trimming window\n"
DEBUGF 1,"Trim, then step 6\n"
;----------------------------
; trim any data not in window
848,10 → 783,9
.no_drop:
DEBUGF 1,"Going to drop %u bytes of data", eax
; eax holds number of bytes to drop
;----------------------------------
; Check for entire duplicate packet
860,6 → 794,11
;;; 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
872,7 → 811,8
mov eax, ecx
and [edx + TCP_segment.Flags], not TH_FIN
or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
;;; TODO: set ACKNOW flag
jmp .no_duplicate
@@:
879,6 → 819,7
; 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
892,14 → 833,12
.duplicate:
DEBUGF 1,"Duplicate received"
;----------------------------------------
; Update statistics for duplicate packets
;;; TODO
jmp .drop ;;; DROP the packet ??
;;; DROP the packet ??
.no_duplicate:
959,6 → 898,7
.no_excess_data:
;-----------------
; Record timestamp
970,8 → 910,6
test [edx + TCP_segment.Flags], TH_RST
jz .rst_skip
DEBUGF 1,"Got an RST flag"
mov eax, [ebx + TCP_SOCKET.t_state]
shl eax, 2
jmp dword [eax + .rst_sw_list]
991,8 → 929,6
.econnrefused:
DEBUGF 1,"Connection refused"
;;; TODO: debug info
jmp .close
999,19 → 935,13
.econnreset:
DEBUGF 1,"Connection reset"
;;; TODO: debug info
.close:
DEBUGF 1,"Closing connection"
;;; update stats
.rst_close:
DEBUGF 1,"Closing with reset"
;;; Close the socket
jmp .drop
1076,15 → 1006,12
;------------------------------------------
; Remove acknowledged data from send buffer
lea eax, [ebx + snd]
mov ecx, ecx ;;;; 943 - 956
call SOCKET_ring_free
;;;; 943 - 956
;---------------------------------------
; Wake up process waiting on send buffer
mov eax, ebx
call SOCKET_notify_owner
;;;;;
mov eax, [ebx + TCP_SOCKET.t_state]
shl eax, 2
1176,6 → 1103,7
.no_window_update:
;-----------------
; process URG flag
1193,7 → 1121,7
;;; 1040-1050
movzx eax, [edx + TCP_segment.UrgentPointer]
add eax, [ebx + rcv.size]
add eax, [ebx + SOCKET.SO_RCV.SB_CC]
cmp eax, SOCKET_MAXDATA
jle .not_urgent
1206,19 → 1134,19
;--------------------------------------
; processing of received urgent pointer
;;; TODO (1051-1093)
;;; 1051-1093
;--------------------------------
; process the data in the segment
align 4
.do_data:
DEBUGF 1,"TCP: do data:\n"
DEBUGF 1,"Do data:\n"
; process the data in the segment
test [edx + TCP_segment.Flags], TH_FIN
jnz .process_fin
jz .process_fin
test [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1
test [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1 ;;;;;
jge .dont_do_data
DEBUGF 1,"Processing data in segment\n"
1230,6 → 1158,7
.dont_do_data:
;---------------
; FIN processing
1280,26 → 1209,16
;jnz .outputnow
test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
jnz .ack_now
jz .ret
mov [ebx + SOCKET.lock], 0
call kernel_free
add esp, 4
ret
.ack_now:
DEBUGF 1,"ACK now!\n"
push ebx
mov eax, ebx
.outputnow:
call TCP_output
pop ebx
.ret:
mov [ebx + SOCKET.lock], 0
call kernel_free
add esp, 4
ret
ret 4
;------------------------------------------
; Generate an ACK, droping incoming segment
1314,15 → 1233,12
and [ebx + TCP_SOCKET.t_flags], TF_ACKNOW
push ebx
mov eax, ebx
call TCP_output
pop ebx
mov [ebx + SOCKET.lock], 0
call kernel_free
add esp, 4
ret
ret 4
;-------------------------------------------
1345,15 → 1261,15
jnz .respond_syn
mov [ebx + SOCKET.lock], 0
call kernel_free
add esp, 4
ret
ret 4
.respond_ack:
;;;;
call TCP_respond_segment
call TCP_respond
jmp .destroy_new_socket
1362,7 → 1278,7
;;;;
call TCP_respond_segment
call TCP_respond
jmp .destroy_new_socket
1381,16 → 1297,128
;;;; kill the newly created socket
mov [ebx + SOCKET.lock], 0
call kernel_free
add esp, 4
ret
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
;
1413,6 → 1441,14
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;-----------------------------------------------------------------
;
; TCP_output
1458,7 → 1494,7
mov ecx, [eax + TCP_SOCKET.SND_CWND] ;
@@: ;
call TCP_outflags ; in dl
call TCP_outflags
; If in persist timeout with window of 0, send 1 byte.
; Otherwise, if window is small but nonzero, and timer expired,
1470,7 → 1506,7
test ecx, ecx
jnz .no_zero_window
cmp ebx, [eax + snd.size]
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?
1481,7 → 1517,7
.no_zero_window:
mov [eax + TCP_SOCKET.timer_persist], 0 ;;;;
;;; mov [eax + TCP_SOCKET.t_timer....TCPT_PERSIST], 0
mov [eax + TCP_SOCKET.t_rxtshift], 0
.no_persist_timeout:
1488,7 → 1524,7
;;;106
mov esi, [eax + snd.size]
mov esi, [eax + SOCKET.SO_SND.SB_CC]
cmp esi, ecx
jl @f
mov esi, ecx
1510,7 → 1546,7
test ecx, ecx
jnz @f
mov [eax + TCP_SOCKET.timer_retransmission], 0 ; cancel retransmit
;;; mov [eax + TCP_SOCKET.t_timer..TCPT_REXMT], 0
push [eax + TCP_SOCKET.SND_UNA]
pop [eax + TCP_SOCKET.SND_NXT]
1533,7 → 1569,7
mov edi, [eax + TCP_SOCKET.SND_NXT]
add edi, esi ; len
sub edi, [eax + TCP_SOCKET.SND_UNA]
add edi, [eax + snd.size]
add edi, [eax + SOCKET.SO_SND.SB_CC]
cmp edi, 0
jle @f
1542,16 → 1578,17
@@:
; set ecx to space available in receive buffer
; From now on, ecx will be the window we advertise to the other end
;;;; 130 TODO: set window (ecx) to space in send buffer
mov ecx, SOCKET_MAXDATA
sub ecx, [eax + rcv.size]
;------------------------------
; Sender silly window avoidance
cmp ecx, [eax + TCP_SOCKET.t_maxseg]
test esi, esi
jz .zero_length
cmp esi, [eax + TCP_SOCKET.t_maxseg]
je .send
;;; TODO: 144-145
1559,20 → 1596,16
test [eax + TCP_SOCKET.t_force], -1
jnz .send
mov ebx, [eax + TCP_SOCKET.max_sndwnd]
shr ebx, 1
cmp ecx, ebx
jge .send
;;; TODO: 149..152
mov ebx, [eax + TCP_SOCKET.SND_NXT]
cmp ebx, [eax + TCP_SOCKET.SND_MAX]
jl .send
.zero_length:
;----------------------------------------
; Check if a window update should be sent
test ecx, ecx ; window
jz .no_window
cmp ecx, 0 ; window
jle .no_window
;;; TODO 154-172
1608,6 → 1641,8
DEBUGF 1,"Entering persist state\n"
;--------------------------------------
; No reason to send a segment, just ret
1616,11 → 1651,14
ret
;-----------------------------------------------
;
; Send a segment
;
; eax = socket pointer
; ebx = socket pointer
; dl = flags
;
;-----------------------------------------------
1629,11 → 1667,8
DEBUGF 1,"Preparing to send a segment\n"
mov edi, TCP_segment.Data ; edi will contain headersize
xor edi, edi ; edi will contain the number of header option bytes
sub esp, 8 ; create some space on stack
push eax ; save this too..
;------------------------------------
; Send options with first SYN segment
1640,32 → 1675,35
test dl, TH_SYN
jz .no_options
push [eax + TCP_SOCKET.ISS]
pop [eax + TCP_SOCKET.SND_NXT]
mov eax, [ebx + TCP_SOCKET.ISS]
mov [ebx + TCP_SOCKET.SND_NXT], eax
test [eax + TCP_SOCKET.t_flags], TF_NOOPT
test [ebx + TCP_SOCKET.t_flags], TF_NOOPT
jnz .no_options
mov ecx, 1460
or ecx, TCP_OPT_MAXSEG shl 24 + 4 shl 16
bswap ecx
push ecx
add di, 4
mov eax, TCP_OPT_MAXSEG shl 24 + 4 shl 16
mov ax, 1280 ;;;;;;
bswap eax
push eax
test [eax + TCP_SOCKET.t_flags], TF_REQ_SCALE
mov di, 4
test [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
jz .no_syn
test dl, TH_ACK
jnz .scale_opt
test [eax + TCP_SOCKET.t_flags], TF_RCVD_SCALE
test [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
jz .no_syn
.scale_opt:
movzx ecx, byte [eax + TCP_SOCKET.request_r_scale]
or ecx, TCP_OPT_WINDOW shl 24 + 4 shl 16 + TCP_OPT_NOP shl 8
bswap ecx
pushd ecx
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:
1673,7 → 1711,7
;------------------------------------
; Make the timestamp option if needed
test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP
test [ebx + TCP_SOCKET.t_flags], TF_REQ_TSTMP
jz .no_timestamp
test dl, TH_RST
1682,129 → 1720,145
test dl, TH_ACK
jz .timestamp
test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
test [ebx + TCP_SOCKET.t_flags], TF_RCVD_TSTMP
jz .no_timestamp
.timestamp:
mov esi, [timer_ticks]
bswap esi
push esi
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
pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24
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:
; eax = socket ptr
; edx = flags
; ecx = data size
; edi = header size
; esi = snd ring buff ptr
add edi, TCP_segment.Data
xor ecx, ecx ;;;;;
;-----------------------------------
; 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
; Start by pushing all TCP header values in reverse order on stack
; (essentially, creating the tcp header!)
mov eax, [ebx + IP_SOCKET.RemoteIP]
mov ebx, [ebx + IP_SOCKET.LocalIP]
mov di , IP_PROTO_TCP
call IPv4_create_packet
pushw 0 ; .UrgentPointer dw ?
pushw 0 ; .Checksum dw ?
pushw 0x00a0 ; .Window dw ? ;;;;;;;
shl edi, 2 ; .DataOffset db ? only 4 left-most bits
shl dx, 8
or dx, di ; .Flags db ?
pushw dx
shr edi, 2 ; .DataOffset db ? ;;;;
;;;; jz .fail
push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ?
ntohld [esp]
push edx eax
call [ebx + NET_DEVICE.transmit]
ret
push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ?
ntohld [esp]
;----------------
push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ?
ntohlw [esp]
push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ?
ntohlw [esp]
;-------------------------------
; Now, create the 20-byte header
push edi ; header size
.header:
; Create the IP packet
mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip
mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip
; mov ecx, ; data length
; mov dx, ; fragment id
mov di, IP_PROTO_TCP shl 8 + 128
call IPv4_output
jz .fail
;-----------------------
; Fill in the TCP header
pop esi
;-----------------------------------------
; Move TCP header from stack to TCP packet
push [esi + TCP_SOCKET.SND_NXT]
rol word [esp], 8
rol dword [esp], 16
pop [edi + TCP_segment.SequenceNumber]
; pop ecx ; header size
; mov esi, esp
; add esp, ecx
; shr ecx, 2
; rep movsd
push [esi + TCP_SOCKET.RCV_NXT]
rol word [esp], 8
rol dword [esp], 16
pop [edi + TCP_segment.AckNumber]
mov ecx, [esp]
lea esi, [esp+4]
shr ecx, 2
rep movsd
push [esi + TCP_SOCKET.LocalPort]
rol word [esp], 8
pop [edi + TCP_segment.SourcePort]
pop ecx
add esp, ecx
push [esi + TCP_SOCKET.RemotePort]
rol word [esp], 8
pop [edi + TCP_segment.DestinationPort]
mov [esp + 3*4+4], edx ; packet size
mov [esp + 3*4], eax ; packet ptr
mov edx, edi
sub edx, ecx
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
; eax = ptr to ring struct
; ecx = buffer size
; edi = ptr to buffer
pop esi
push edi
add edi, TCP_segment.Data ;;
sub ecx, TCP_segment.Data ;;;
mov eax, [esp] ; socket ptr
push ecx edx
add eax, snd
call SOCKET_ring_read
pop esi ecx
pop eax
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 (we have already pushed IPs onto stack)
;--------------------
; Create the checksum
DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx
DEBUGF 1,"ip=%x\n", [esp]:8
DEBUGF 1,"ip=%x\n", [esp+4]:8
push [ebx + IP_SOCKET.LocalIP]
push [ebx + IP_SOCKET.RemoteIP]
call TCP_checksum
TCP_checksum (eax + IP_SOCKET.LocalIP), (eax + IP_SOCKET.RemoteIP)
mov [esi+TCP_segment.Checksum], dx
;----------------
; Send the packet
;;;;;
DEBUGF 1,"Sending TCP Packet to device %x\n", ebx
call [ebx + NET_DEVICE.transmit]
ret
.fail:
pop ecx
add esp, ecx
add esp, 4+4+8+4
DEBUGF 1,"TCP_output: failed\n"
ret
;-------------------------
;
; TCP_outflags
1839,8 → 1893,6
db TH_ACK ; TCB_TIMED_WAIT
;-------------------------
;
; TCP_drop
1872,68 → 1924,62
;---------------------------------------
;
; TCP_ack
;
; The easy way to send an ACK/RST/keepalive segment
;
; TCP_respond_socket:
;
; IN: ebx = socket ptr
; IN: eax = socket ptr
; -or-
; edx = packet ptr (eax must be 0)
; cl = flags
;
;--------------------------------------
; OUT: /
;
;---------------------------------------
align 4
TCP_respond_socket:
TCP_respond:
DEBUGF 1,"TCP_respond_socket\n"
DEBUGF 1,"TCP_respond\n"
;---------------------
; Create the IP packet
push cx ebx
mov eax, [ebx + IP_SOCKET.RemoteIP]
mov ebx, [ebx + IP_SOCKET.LocalIP]
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 shl 8 + 128
call IPv4_output
mov di , IP_PROTO_TCP
call IPv4_create_packet
test edi, edi
jz .error
pop esi cx
;---------------------------
; Now fill in the TCP header
pop ecx
pop esi
test esi, esi
; jz
push edx eax
;-----------------------------------------------
; Fill in the TCP header by using the socket ptr
push dword .checksum
je .use_segment
jmp .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
;---------------------
; Fill in the checksum
.checksum:
sub edi, TCP_segment.Data
mov ecx, TCP_segment.Data
xchg esi, edi
TCP_checksum (edi + IP_SOCKET.LocalIP), (esi + IP_SOCKET.RemoteIP)
mov [esi+TCP_segment.Checksum], dx
push [esi + IP_SOCKET.LocalIP]
push [esi + IP_SOCKET.RemoteIP]
lea esi, [edi - 20]
xor ecx, ecx
call TCP_checksum
;--------------------
; And send the segment
1941,42 → 1987,16
ret
.error:
DEBUGF 1,"TCP_respond failed\n"
add esp, 2+4
DEBUGF 1,"TCP_ack failed\n"
add esp, 4
ret
;-------------------------
; TCP_respond.segment:
;
; IN: edx = segment ptr (a previously received segment)
; cl = flags
align 4
TCP_respond_segment:
DEBUGF 1,"TCP_respond_segment\n"
;---------------------
; Create the IP packet
push cx edx
mov ebx, [edx - 20 + IPv4_Packet.SourceAddress] ;;;; and what if ip packet had options?!
mov eax, [edx - 20 + IPv4_Packet.DestinationAddress] ;;;
mov ecx, TCP_segment.Data
mov di , IP_PROTO_TCP shl 8 + 128
call IPv4_output
test edi, edi
jz .error
pop esi cx
push edx eax
;---------------------------------------------------
; Fill in the TCP header by using a received segment
.use_segment:
mov ax, [esi + TCP_segment.DestinationPort]
rol ax, 8
stosw
1998,30 → 2018,98
xor eax, eax
stosd ; checksum + urgentpointer
;---------------------
; Fill in the checksum
ret
.checksum:
lea esi, [edi - TCP_segment.Data]
mov ecx, TCP_segment.Data
TCP_checksum (esi - 20 + IPv4_Packet.DestinationAddress), (esi - 20 + IPv4_Packet.DestinationAddress)
mov [esi+TCP_segment.Checksum], dx
;--------------------
; And send the segment
;-----------------------------------------------
; Fill in the TCP header by using the socket ptr
call [ebx + NET_DEVICE.transmit]
ret
.use_socket:
.error:
DEBUGF 1,"TCP_respond failed\n"
add esp, 2+4
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