120,2086 → 120,12 |
} |
|
|
;---------------------- |
; |
; |
;---------------------- |
macro TCP_timer_160ms { |
include 'tcp_timer.inc' |
include 'tcp_subr.inc' |
include 'tcp_input.inc' |
include 'tcp_output.inc' |
|
local .loop |
local .exit |
|
mov eax, net_sockets |
.loop: |
mov eax, [eax + SOCKET.NextPtr] |
or eax, eax |
jz .exit |
|
cmp [eax + SOCKET.Protocol], IP_PROTO_TCP ;;; We should also check if family is AF_INET |
jne .loop |
|
dec [eax + TCP_SOCKET.timer_ack] |
jnz .loop |
|
DEBUGF 1,"TCP ack for socket %x expired, time to piggyback!\n", eax |
|
push eax |
call TCP_respond_socket |
pop eax |
|
jmp .loop |
|
.exit: |
|
} |
|
|
;----------------------------------------------------------------- |
; |
; |
;----------------------------------------------------------------- |
macro TCP_timer_640ms { |
|
local .loop |
local .exit |
|
; Update TCP sequence number |
|
add [TCP_sequence_num], 64000 |
|
; scan through all the active TCP sockets, decrementing ALL timers |
; timers do not have the chance to wrap because of the keepalive timer will kill the socket when it expires |
|
mov eax, net_sockets |
.loop: |
mov eax, [eax + SOCKET.NextPtr] |
.check_only: |
or eax, eax |
jz .exit |
|
cmp [eax + SOCKET.Protocol], IP_PROTO_TCP ;;; We should also check if family is AF_INET |
jne .loop |
|
inc [eax + TCP_SOCKET.t_idle] |
dec [eax + TCP_SOCKET.timer_retransmission] |
jnz .check_more2 |
|
DEBUGF 1,"socket %x: Retransmission timer expired\n", eax |
|
push eax |
call TCP_output |
pop eax |
|
.check_more2: |
dec [eax + TCP_SOCKET.timer_keepalive] |
jnz .check_more3 |
|
DEBUGF 1,"socket %x: Keepalive expired\n", eax |
|
;;; TODO: check socket state and handle accordingly |
|
.check_more3: |
dec [eax + TCP_SOCKET.timer_timed_wait] |
jnz .check_more5 |
|
DEBUGF 1,"socket %x: 2MSL timer expired\n", eax |
|
.check_more5: |
dec [eax + TCP_SOCKET.timer_persist] |
jnz .loop |
|
DEBUGF 1,"socket %x: persist timer expired\n", eax |
|
jmp .loop |
.exit: |
} |
|
|
|
|
macro TCP_checksum IP1, IP2 { |
|
;------------- |
; Pseudoheader |
|
; protocol type |
mov edx, IP_PROTO_TCP |
|
; source address |
add dl, byte [IP1+1] |
adc dh, byte [IP1+0] |
adc dl, byte [IP1+3] |
adc dh, byte [IP1+2] |
|
; destination address |
adc dl, byte [IP2+1] |
adc dh, byte [IP2+0] |
adc dl, byte [IP2+3] |
adc dh, byte [IP2+2] |
|
; 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 |
|
|
macro TCP_sendseqinit ptr { |
|
push edi ;;;; i dont like this static use of edi |
mov edi, [ptr + TCP_SOCKET.ISS] |
mov [ptr + TCP_SOCKET.SND_UP], edi |
mov [ptr + TCP_SOCKET.SND_MAX], edi |
mov [ptr + TCP_SOCKET.SND_NXT], edi |
mov [ptr + TCP_SOCKET.SND_UNA], edi |
pop edi |
|
} |
|
macro TCP_rcvseqinit ptr { |
|
push edi |
mov edi, [ptr + TCP_SOCKET.IRS] |
inc edi |
mov [ptr + TCP_SOCKET.RCV_NXT], edi |
mov [ptr + TCP_SOCKET.RCV_ADV], edi |
pop edi |
|
} |
|
|
|
;----------------------------------------------------------------- |
; |
; TCP_input: |
; |
; IN: [esp] = ptr to buffer |
; [esp+4] = buffer size |
; ebx = ptr to device struct |
; ecx = segment size |
; edx = ptr to TCP segment |
; |
; esi = ipv4 source address |
; edi = ipv4 dest address |
; |
; OUT: / |
; |
;----------------------------------------------------------------- |
align 4 |
TCP_input: |
|
DEBUGF 1,"TCP_input size=%u\n", ecx |
; 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] |
and eax, 0xf0 |
shr al, 2 |
|
DEBUGF 1,"headersize=%u\n", eax |
|
cmp eax, 20 |
jl .drop |
|
;------------------------------- |
; Now, re-calculate the checksum |
|
push eax ecx edx |
pushw [edx + TCP_segment.Checksum] |
mov [edx + TCP_segment.Checksum], 0 |
push esi edi |
mov esi, edx |
TCP_checksum (esp), (esp+4) |
pop esi edi ; yes, swap them (we dont need dest addr) |
pop cx ; previous checksum |
cmp cx, dx |
pop edx ecx esi |
jnz .drop |
|
DEBUGF 1,"Checksum is correct\n" |
|
sub ecx, esi ; update packet size |
jl .drop |
DEBUGF 1,"we got %u bytes of data\n", ecx |
|
;----------------------------------------------------------------------------------------- |
; 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 |
jl .no_timestamp |
je .is_ok |
|
cmp byte [edx + TCP_segment.Data + 12], TCP_OPT_EOL ; end of option list |
jne .no_timestamp |
|
.is_ok: |
test [edx + TCP_segment.Flags], TH_SYN ; SYN flag must not be set |
jnz .no_timestamp |
|
cmp dword [edx + TCP_segment.Data], 0x0101080a ; Timestamp header |
jne .no_timestamp |
|
DEBUGF 1,"timestamp ok\n" |
|
; TODO: Parse the option |
; TODO: Set a Bit in the TCP to tell all options are parsed |
|
.no_timestamp: |
|
;------------------------------------------- |
; Convert Big-endian values to little endian |
|
ntohd [edx + TCP_segment.SequenceNumber] |
ntohd [edx + TCP_segment.AckNumber] |
|
ntohw [edx + TCP_segment.Window] |
ntohw [edx + TCP_segment.UrgentPointer] |
ntohw [edx + TCP_segment.SourcePort] |
ntohw [edx + TCP_segment.DestinationPort] |
|
;------------------------------------------------------------ |
; Next thing to do is find the TCB (thus, the socket pointer) |
|
; IP Packet TCP Destination Port = local Port |
; (IP Packet SenderAddress = Remote IP) OR (Remote IP = 0) |
; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0) |
|
mov ebx, net_sockets |
|
.socket_loop: |
mov ebx, [ebx + SOCKET.NextPtr] |
or ebx, ebx |
jz .drop_with_reset |
|
cmp [ebx + SOCKET.Domain], AF_INET4 |
jne .socket_loop |
|
cmp [ebx + SOCKET.Protocol], IP_PROTO_TCP |
jne .socket_loop |
|
mov ax, [edx + TCP_segment.DestinationPort] |
cmp [ebx + TCP_SOCKET.LocalPort], ax |
jne .socket_loop |
|
mov eax, [ebx + IP_SOCKET.RemoteIP] |
cmp eax, edi ; edi is source ip from packet |
je @f |
test eax, eax |
jnz .socket_loop |
@@: |
|
mov ax, [ebx + TCP_SOCKET.RemotePort] |
cmp [edx + TCP_segment.SourcePort] , ax |
je .found_socket |
test ax, ax |
jnz .socket_loop |
.found_socket: |
DEBUGF 1,"Socket ptr: %x\n", ebx |
|
; ebx now contains the pointer to the socket |
|
;---------------------------- |
; Check if socket isnt closed |
|
cmp [ebx + 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 |
|
DEBUGF 1,"Socket locked\n" |
|
;--------------------------------------- |
; unscale the window into a 32 bit value |
|
movzx eax, [edx + TCP_segment.Window] |
push ecx |
mov cl, [ebx + TCP_SOCKET.SND_SCALE] |
shl eax, cl |
mov dword [edx + TCP_segment.Window], eax ; word after window is checksum, we dont need checksum anymore |
pop ecx |
|
;----------------------------------- |
; Is this socket a listening socket? |
|
test [ebx + SOCKET.options], SO_ACCEPTCON |
jz .no_listening_socket |
|
call SOCKET_fork |
jz .drop |
|
push [edx + TCP_segment.DestinationPort] |
pop [eax + TCP_SOCKET.LocalPort] |
|
push [edx - IPv4_Packet.DataOrOptional + IPv4_Packet.DestinationAddress] ;;; FIXME |
pop [eax + IP_SOCKET.LocalIP] |
|
push [edx - IPv4_Packet.DataOrOptional + IPv4_Packet.SourceAddress] ;;; FIXME |
pop [eax + IP_SOCKET.RemoteIP] |
|
mov [eax + TCP_SOCKET.t_state], TCB_LISTEN |
|
jmp .not_uni_xfer |
|
.no_listening_socket: |
|
;------------------------------------- |
; Reset idle timer and keepalive timer |
|
mov [ebx + TCP_SOCKET.t_idle], 0 |
mov [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval |
|
;-------------------- |
; Process TCP options |
|
cmp esi, 20 ; esi is headersize |
je .no_options |
|
DEBUGF 1,"Segment has options\n" |
|
cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN ; no options when in listen state |
jz .not_uni_xfer ; also no header prediction |
|
lea edi, [edx + TCP_segment.Data] |
lea eax, [edx + esi] |
|
.opt_loop: |
cmp edi, eax |
jge .no_options |
|
cmp byte [edi], TCP_OPT_EOL ; end of option list? |
jz .no_options |
|
cmp byte [edi], TCP_OPT_NOP ; nop ? |
jz .opt_nop |
|
cmp byte [edi], TCP_OPT_MAXSEG |
je .opt_maxseg |
|
cmp byte [edi], TCP_OPT_WINDOW |
je .opt_window |
|
cmp byte [edi], TCP_OPT_TIMESTAMP |
je .opt_timestamp |
|
jmp .no_options ; If we reach here, some unknown options were received, skip them all! |
|
.opt_nop: |
inc edi |
jmp .opt_loop |
|
.opt_maxseg: |
cmp byte [edi+1], 4 |
jne .no_options ; error occured, ignore all options! |
|
test [edx + TCP_segment.Flags], TH_SYN |
jz @f |
|
movzx eax, word[edi+2] |
rol ax, 8 |
DEBUGF 1,"Maxseg: %u\n", ax |
|
mov [ebx + TCP_SOCKET.t_maxseg], eax |
|
@@: |
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\n" |
|
;;;;; |
@@: |
add edi, 3 |
jmp .opt_loop |
|
|
.opt_timestamp: |
cmp byte [edi+1], 10 |
jne .no_options |
|
DEBUGF 1,"Got timestamp option\n" |
|
;;;;; |
|
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, |
; window width didnt change and we're not retransmitting. |
; |
; Second rules: |
; - If the length is 0 and the ACK moved forward, we're the sender side of the transfer. |
; In this case we'll free the ACK'ed data and notify higher levels that we have free space in buffer |
; |
; - 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 |
jnz .not_uni_xfer |
|
test [edx + TCP_segment.Flags], TH_SYN + TH_FIN + TH_RST + TH_URG |
jnz .not_uni_xfer |
|
test [edx + TCP_segment.Flags], TH_ACK |
jz .not_uni_xfer |
|
mov eax, [edx + TCP_segment.SequenceNumber] |
cmp eax, [ebx + TCP_SOCKET.RCV_NXT] |
jne .not_uni_xfer |
DEBUGF 1,"TCP_segment.window=%u\n", [edx + TCP_segment.Window]:4 |
DEBUGF 1,"TCP_SOCKET.SND_WND=%u\n", [ebx + TCP_SOCKET.SND_WND]:4 |
mov eax, dword [edx + TCP_segment.Window] |
cmp eax, [ebx + TCP_SOCKET.SND_WND] |
jne .not_uni_xfer |
|
mov eax, [ebx + TCP_SOCKET.SND_NXT] |
cmp eax, [ebx + TCP_SOCKET.SND_MAX] |
jne .not_uni_xfer |
|
;--------------------------------------- |
; 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 |
jnz .not_sender |
|
; - The congestion window is greater than or equal to the current send window. |
; 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 eax, [edx + TCP_segment.AckNumber] |
cmp eax, [ebx + TCP_SOCKET.SND_MAX] |
jg .not_uni_xfer |
|
; - The acknowledgment field in the segment is greater than the largest unacknowledged sequence number. |
sub eax, [ebx + TCP_SOCKET.SND_UNA] |
jle .not_uni_xfer |
|
DEBUGF 1,"Header prediction: we are sender\n" |
|
;--------------------------------- |
; Packet is a pure ACK, process it |
|
; Update RTT estimators |
|
; Delete acknowledged bytes from send buffer |
pusha |
mov ecx, eax |
lea eax, [ebx + STREAM_SOCKET.snd] |
call SOCKET_ring_free |
popa |
|
; update window pointers |
mov eax, [edx + TCP_segment.AckNumber] |
dec eax |
mov [ebx + TCP_SOCKET.SND_WL1], eax |
|
; Stop retransmit timer |
mov [ebx + TCP_SOCKET.timer_ack], 0 |
|
; Awaken waiting processes |
mov eax, ebx |
call SOCKET_notify_owner |
|
;; Generate more output FIXME |
;; mov eax, ebx |
;; call TCP_output |
;; |
;; jmp .drop |
jmp .ack_processed |
|
;------------------------------------------------- |
; 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 acknowledgment field 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). |
|
;;;;;;; TODO |
|
jnz .not_uni_xfer |
|
;------------------------------------- |
; Complete processing of received data |
|
DEBUGF 1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx |
|
pusha |
add esi, edx |
lea eax, [ebx + STREAM_SOCKET.rcv] |
call SOCKET_ring_write ; Add the data to the socket buffer |
|
mov eax, ebx |
call SOCKET_notify_owner |
popa |
|
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 |
|
jmp .drop |
|
;---------------------------------------------------- |
; Header prediction failed, doing it the slow way.. ;;;;; current implementation of header prediction destroys some regs (ecx) !! |
|
.not_uni_xfer: |
|
DEBUGF 1,"Header prediction failed\n" ; time to do it the "slow" way :) |
|
;------------------------------ |
; Calculate receive window size |
|
;;;; |
|
cmp [ebx + TCP_SOCKET.t_state], TCB_LISTEN |
je .LISTEN |
|
cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_SENT |
je .SYN_SENT |
|
;-------------------------------------------- |
; Protection Against Wrapped Sequence Numbers |
|
; First, check if timestamp is present |
|
;;;; TODO |
|
; Then, check if at least some bytes of data are within window |
|
;;;; TODO |
|
jmp .trim_then_step6 |
|
;------------- |
; Passive Open |
|
align 4 |
.LISTEN: |
|
DEBUGF 1,"TCP state: listen\n" |
|
test [edx + TCP_segment.Flags], TH_RST ;;; TODO: kill new socket on error |
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 |
|
;----------------------- |
; Fill in some variables |
|
add [TCP_sequence_num], 64000 |
|
push [edx + TCP_segment.SourcePort] |
pop [eax + TCP_SOCKET.RemotePort] |
|
push [edx + TCP_segment.SequenceNumber] |
pop [eax + TCP_SOCKET.IRS] |
|
push [eax + TCP_SOCKET.ISS] |
pop [eax + TCP_SOCKET.SND_NXT] |
|
TCP_sendseqinit eax |
TCP_rcvseqinit 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 ;;;; macro |
|
add eax, STREAM_SOCKET.snd |
call SOCKET_ring_create |
|
add eax, STREAM_SOCKET.rcv - STREAM_SOCKET.snd |
call SOCKET_ring_create |
|
sub eax, STREAM_SOCKET.rcv |
|
mov [eax + SOCKET.lock], 0 |
mov ebx, eax ; if there is data, it must arrive in this new socket! |
jmp .trim_then_step6 |
|
|
;------------ |
; Active Open |
|
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 |
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 |
|
mov eax, ebx |
mov ebx, ECONNREFUSED |
call TCP_drop |
|
jmp .drop |
@@: |
|
test [edx + TCP_segment.Flags], TH_SYN |
jz .drop |
|
; at this point, segment seems to be valid |
|
test [edx + TCP_segment.Flags], TH_ACK |
jz .no_syn_ack |
|
; now, process received SYN in response to an active open |
|
mov eax, [edx + TCP_segment.AckNumber] |
mov [ebx + TCP_SOCKET.SND_UNA], eax |
cmp eax, [ebx + TCP_SOCKET.SND_NXT] |
jle @f |
mov [ebx + TCP_SOCKET.SND_NXT], eax |
@@: |
|
.no_syn_ack: |
|
mov [ebx + TCP_SOCKET.timer_retransmission], 0 ; disable retransmission |
|
push [edx + TCP_segment.SequenceNumber] |
pop [ebx + TCP_SOCKET.IRS] |
|
TCP_rcvseqinit ebx |
|
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 general 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 |
|
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 |
|
;------------------------------------- |
; 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 .ack_processed |
|
|
.trim_then_step6: |
|
;---------------------------- |
; trim any data not in window |
|
DEBUGF 1,"Trimming window\n" |
|
mov eax, [ebx + TCP_SOCKET.RCV_NXT] |
sub eax, [edx + TCP_segment.SequenceNumber] |
jz .no_duplicate |
|
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 |
jz .no_duplicate |
.no_drop: |
|
DEBUGF 1,"Going to drop %u out of %u bytes\n", eax, ecx |
|
; eax holds number of bytes to drop |
|
;---------------------------------- |
; Check for entire duplicate packet |
|
cmp eax, ecx |
jge .duplicate |
|
;;; TODO: figure 28.30 |
|
;------------------------ |
; 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 |
or [ebx + TCP_SOCKET.t_flags], TF_ACKNOW |
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: |
|
DEBUGF 1,"Duplicate received\n" |
|
;---------------------------------------- |
; Update statistics for duplicate packets |
|
;;; TODO |
|
jmp .drop ;;; 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 |
jg @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 |
|
DEBUGF 1,"Got an RST flag" |
|
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: |
|
DEBUGF 1,"Connection refused" |
|
;;; TODO: debug info |
|
jmp .close |
|
.econnreset: |
|
DEBUGF 1,"Connection reset" |
|
;;; TODO: debug info |
.close: |
|
DEBUGF 1,"Closing connection" |
|
;;; update stats |
|
.rst_close: |
|
DEBUGF 1,"Closing with reset\n" |
|
;;; Close the socket |
jmp .drop |
|
.rst_skip: |
|
;-------------------------------------- |
; handle SYN-full and ACK-less segments |
|
test [edx + TCP_segment.Flags], TH_SYN |
jz @f |
|
mov eax, ebx |
mov ebx, ECONNRESET |
call TCP_drop |
|
jmp .drop_with_reset |
|
test [edx + TCP_segment.Flags], TH_ACK |
jz .drop |
@@: |
|
;--------------- |
; ACK processing |
|
cmp [ebx + TCP_SOCKET.t_state], TCB_SYN_RECEIVED |
jnz .no_syn_rcv |
|
DEBUGF 1,"TCP state = syn received\n" |
|
;;;;; 801-815 |
|
.no_syn_rcv: |
|
; check for duplicate ACK |
|
mov eax, [edx + TCP_segment.AckNumber] |
cmp eax, [ebx + TCP_SOCKET.SND_UNA] |
jg .not_dup_ack |
|
DEBUGF 1,"Duplicate ACK\n" |
|
test ecx, ecx |
jnz .ack_processed |
|
mov eax, dword [edx + TCP_segment.Window] |
cmp eax, [ebx + TCP_SOCKET.SND_WND] |
jne .ack_processed |
|
; Process the duplicate ACK |
|
;;;;; 833 - 878 |
|
;;; call TCP_output |
jmp .drop |
|
.not_dup_ack: |
|
DEBUGF 1,"new ACK\n" |
|
|
;------------------------------------------------- |
; If the congestion window was inflated to account |
; for the other side's cached packets, retract 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 (use a macro for it) |
.all_outstanding: |
|
;------------------------------------------- |
; Open congestion window in response to ACKs |
|
;;;; |
|
|
;------------------------------------------ |
; Remove acknowledged data from send buffer |
|
pusha |
mov ecx, [edx + TCP_segment.AckNumber] |
sub ecx, [ebx + TCP_SOCKET.SND_UNA] ; ecx now holds number of bytes acked |
|
lea eax, [ebx + STREAM_SOCKET.snd] |
call SOCKET_ring_free |
popa |
|
;--------------------------------------- |
; Wake up process waiting on send buffer |
|
mov eax, ebx |
call SOCKET_notify_owner |
|
; Update TCB |
|
mov eax, [edx + TCP_segment.AckNumber] |
mov [ebx + TCP_SOCKET.SND_UNA], eax |
|
cmp eax, [ebx + TCP_SOCKET.SND_NXT] |
jl @f |
mov [ebx + TCP_SOCKET.SND_NXT], eax |
@@: |
|
; General ACK handling complete |
; Now do the state-specific ones |
|
mov eax, [ebx + TCP_SOCKET.t_state] |
jmp dword [eax*4 + .ACK_sw_list] |
|
.ACK_sw_list: |
dd .ack_processed ;TCB_CLOSED |
dd .ack_processed ;TCB_LISTEN |
dd .ack_processed ;TCB_SYN_SENT |
dd .ack_processed ;TCB_SYN_RECEIVED |
dd .ack_processed ;TCB_ESTABLISHED |
dd .ack_processed ;TCB_CLOSE_WAIT |
dd .ack_fw1 ;TCB_FIN_WAIT_1 |
dd .ack_c ;TCB_CLOSING |
dd .ack_la ;TCB_LAST_ACK |
dd .ack_processed ;TCB_FIN_WAIT_2 |
dd .ack_tw ;TCB_TIMED_WAIT |
|
|
.ack_fw1: |
|
;;; TODO: 963 |
|
jmp .ack_processed |
|
.ack_c: |
|
;;; TODO: 958 |
|
jmp .ack_processed |
|
.ack_la: |
|
;;; TODO: 999 |
|
jmp .ack_processed |
|
|
.ack_tw: |
|
;;; TODO: 1010 |
|
jmp .ack_processed |
|
|
.ack_processed: |
|
DEBUGF 1,"ack processed\n" |
|
;---------------------------------------------- |
; check if we need to 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] |
jl .update_window |
jg @f |
|
mov eax, [ebx + TCP_SOCKET.SND_WL2] |
cmp eax, [edx + TCP_segment.AckNumber] |
jl .update_window |
jg .no_window_update |
@@: |
|
mov eax, [ebx + TCP_SOCKET.SND_WL2] |
cmp eax, [edx + TCP_segment.AckNumber] |
jne .no_window_update |
|
movzx eax, [edx + TCP_segment.Window] |
cmp eax, [ebx + TCP_SOCKET.SND_WND] |
jle .no_window_update |
|
.update_window: |
|
DEBUGF 1,"Updating window\n" |
|
;---------------------------------- |
; 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, dword [edx + TCP_segment.Window] |
cmp eax, [ebx + TCP_SOCKET.max_sndwnd] |
jle @f |
mov [ebx + TCP_SOCKET.max_sndwnd], eax |
@@: |
mov [ebx + TCP_SOCKET.SND_WND], eax |
|
push [edx + TCP_segment.SequenceNumber] |
pop [ebx + TCP_SOCKET.SND_WL1] |
|
push [edx + TCP_segment.AckNumber] |
pop [ebx + TCP_SOCKET.SND_WL2] |
|
;;; 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 + STREAM_SOCKET.rcv + RING_BUFFER.size] |
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 |
|
;;; TODO (1051-1093) |
|
;-------------------------------- |
; process the data in the segment |
|
.do_data: |
|
DEBUGF 1,"TCP: do data (%u)\n", ecx |
|
test [edx + TCP_segment.Flags], TH_FIN |
jnz .process_fin |
|
cmp [ebx + TCP_SOCKET.t_state], TCB_FIN_WAIT_1 |
jge .dont_do_data |
|
test ecx, ecx |
jz .final_processing |
|
DEBUGF 1,"Processing data in segment\n" |
|
;; TODO: check if data is in sequence ! |
|
movzx eax, [edx + TCP_segment.DataOffset] ;;; todo: remember this in.. edi ? |
and eax, 0xf0 |
shr al, 2 |
|
lea esi, [edx + eax] |
|
or [ebx + TCP_SOCKET.t_flags], TF_DELACK |
add [ebx + TCP_SOCKET.RCV_NXT], ecx |
|
lea eax, [ebx + STREAM_SOCKET.rcv] |
call SOCKET_ring_write |
|
mov eax, ebx |
call SOCKET_notify_owner |
|
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 .fin_syn_est ;TCB_SYN_RECEIVED |
dd .fin_syn_est ;TCB_ESTABLISHED |
dd .no_fin ;TCB_CLOSE_WAIT |
dd .fin_wait1 ;TCB_FIN_WAIT_1 |
dd .no_fin ;TCB_CLOSING |
dd .no_fin ;TCB_LAST_ACK |
dd .fin_wait2 ;TCB_FIN_WAIT_2 |
dd .fin_timed ;TCB_TIMED_WAIT |
|
|
|
.fin_syn_est: |
|
jmp .final_processing |
|
.fin_wait1: |
|
jmp .final_processing |
|
.fin_wait2: |
|
jmp .final_processing |
|
.fin_timed: |
|
jmp .final_processing |
|
.no_fin: |
|
;----------------- |
; Final processing |
|
.final_processing: |
|
DEBUGF 1,"Final processing\n" |
|
mov [ebx + SOCKET.lock], 0 |
|
;;; if debug enabled, output packet |
|
;test needoutput, needoutput |
;jz .dumpit |
|
test [ebx + TCP_SOCKET.t_flags], TF_ACKNOW |
jz .dumpit |
|
DEBUGF 1,"ACK now!\n" |
|
push ebx |
mov eax, ebx |
call TCP_output |
pop ebx |
|
.dumpit: |
|
call kernel_free |
add esp, 4 |
ret |
|
;------------------------------------------ |
; 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 |
|
push ebx |
mov eax, ebx |
call TCP_output |
pop ebx |
|
call kernel_free |
add esp, 4 |
ret |
|
|
;------------------------------------------- |
; 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 |
|
call kernel_free |
add esp, 4 |
ret |
|
.respond_ack: |
|
mov dl, TH_RST |
|
push ebx |
call TCP_respond_segment |
pop ebx |
|
jmp .destroy_new_socket |
|
|
.respond_syn: |
|
mov dl, TH_RST + TH_ACK |
|
push ebx |
call TCP_respond_socket |
pop ebx |
|
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 |
|
call kernel_free |
add esp, 4 |
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 |
; |
; 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 ; in dl |
|
; 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 + STREAM_SOCKET.snd + RING_BUFFER.size] |
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.timer_persist], 0 |
mov [eax + TCP_SOCKET.t_rxtshift], 0 |
|
.no_persist_timeout: |
|
;;;106 |
|
mov esi, [eax + STREAM_SOCKET.snd + RING_BUFFER.size] |
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.timer_retransmission], 0 ; cancel retransmit |
|
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 + STREAM_SOCKET.snd + RING_BUFFER.size] |
cmp edi, 0 |
jle @f |
|
and dl, not (TH_FIN) ; clear the FIN flag |
|
@@: |
|
|
; set ecx to space available in receive buffer |
; From now on, ecx will be the window we advertise to the other end |
|
mov ecx, SOCKET_MAXDATA |
sub ecx, [eax + STREAM_SOCKET.rcv + RING_BUFFER.size] |
|
;------------------------------ |
; Sender silly window avoidance |
|
cmp ecx, [eax + TCP_SOCKET.t_maxseg] |
je .send |
|
;;; TODO: 144-145 |
|
test [eax + TCP_SOCKET.t_force], -1 |
jnz .send |
|
mov ebx, [eax + TCP_SOCKET.max_sndwnd] |
shr ebx, 1 |
cmp ecx, ebx |
jge .send |
|
mov ebx, [eax + TCP_SOCKET.SND_NXT] |
cmp ebx, [eax + TCP_SOCKET.SND_MAX] |
jl .send |
|
;---------------------------------------- |
; Check if a window update should be sent |
|
test ecx, ecx ; window |
jz .no_window |
|
;;; TODO 154-172 |
|
.no_window: |
|
;-------------------------- |
; Should a segment be sent? |
|
test [eax + TCP_SOCKET.t_flags], TF_ACKNOW |
jnz .send |
|
test dl, TH_SYN + TH_RST |
jnz .send |
|
mov ebx, [eax + TCP_SOCKET.SND_UP] |
cmp ebx, [eax + TCP_SOCKET.SND_UNA] |
jg .send |
|
test dl, TH_FIN |
jz .enter_persist |
|
test [eax + TCP_SOCKET.t_flags], TF_SENTFIN |
jnz .send |
|
mov ebx, [eax + TCP_SOCKET.SND_NXT] |
cmp ebx, [eax + 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 |
; |
; eax = socket pointer |
; dl = flags |
; |
;----------------------------------------------- |
|
.send: |
|
DEBUGF 1,"Preparing to send a segment\n" |
|
mov edi, TCP_segment.Data ; edi will contain headersize |
|
sub esp, 8 ; create some space on stack |
push eax ; save this too.. |
|
;------------------------------------ |
; Send options with first SYN segment |
|
test dl, TH_SYN |
jz .no_options |
|
push [eax + TCP_SOCKET.ISS] |
pop [eax + TCP_SOCKET.SND_NXT] |
|
test [eax + 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 |
|
test [eax + 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 |
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 |
add di, 4 |
|
.no_syn: |
|
;------------------------------------ |
; Make the timestamp option if needed |
|
test [eax + TCP_SOCKET.t_flags], TF_REQ_TSTMP |
jz .no_timestamp |
|
test dl, TH_RST |
jnz .no_timestamp |
|
test dl, TH_ACK |
jz .timestamp |
|
test [eax + TCP_SOCKET.t_flags], TF_RCVD_TSTMP |
jz .no_timestamp |
|
.timestamp: |
mov esi, [timer_ticks] |
bswap esi |
push esi |
pushw 0 |
pushd TCP_OPT_TIMESTAMP + 10 shl 8 + TCP_OPT_NOP shl 16 + TCP_OPT_NOP shl 24 |
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 |
|
mov ecx, [eax + STREAM_SOCKET.snd + RING_BUFFER.size] |
cmp ecx, [eax + TCP_SOCKET.t_maxseg] ;;; right? |
jle @f |
mov ecx, [eax + TCP_SOCKET.t_maxseg] |
@@: |
add ecx, edi ; total TCP segment size |
|
; Start by pushing all TCP header values in reverse order on stack |
; (essentially, creating the tcp header!) |
|
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 ? ;;;; |
|
push [eax + TCP_SOCKET.RCV_NXT] ; .AckNumber dd ? |
ntohd [esp] |
|
push [eax + TCP_SOCKET.SND_NXT] ; .SequenceNumber dd ? |
ntohd [esp] |
|
push [eax + TCP_SOCKET.RemotePort] ; .DestinationPort dw ? |
ntohw [esp] |
|
push [eax + TCP_SOCKET.LocalPort] ; .SourcePort dw ? |
ntohw [esp] |
|
push edi ; header size |
|
; Create the IP packet |
mov ebx, [eax + IP_SOCKET.LocalIP] ; source ip |
mov eax, [eax + IP_SOCKET.RemoteIP] ; dest ip |
mov di, IP_PROTO_TCP shl 8 + 128 |
call IPv4_output |
jz .fail |
|
;----------------------------------------- |
; Move TCP header from stack to TCP packet |
|
push ecx |
mov ecx, [esp+4] |
lea esi, [esp+4+4] |
shr ecx, 2 |
rep movsd |
pop ecx ; full TCP packet size |
|
pop esi ; headersize |
add esp, esi |
|
mov [esp + 4], eax ; packet ptr |
mov [esp + 4+4], edx ; packet size |
|
mov edx, edi ; begin of data |
sub edx, esi ; begin of packet (edi = begin of data) |
push ecx |
sub ecx, esi ; data size |
|
;-------------- |
; Copy the data |
|
; eax = ptr to ring struct |
; ecx = buffer size |
; edi = ptr to buffer |
|
; test ecx, ecx |
mov eax, [esp+4] ; socket ptr |
add [eax + TCP_SOCKET.SND_NXT], ecx |
add eax, STREAM_SOCKET.snd |
push edx |
call SOCKET_ring_read |
pop esi |
pop ecx |
pop eax |
|
test [esi + TCP_segment.Flags], TH_SYN + TH_FIN |
jz @f |
inc [eax + TCP_SOCKET.SND_NXT] |
;;; TODO: update sentfin flag |
@@: |
|
mov edx, [eax + TCP_SOCKET.SND_NXT] |
cmp edx, [eax + TCP_SOCKET.SND_MAX] |
jle @f |
mov [eax + TCP_SOCKET.SND_MAX], edx |
|
;;;; TODO: time transmission (420) |
@@: |
|
;;; TODO: set retransmission timer |
|
;-------------------- |
; Create the checksum |
|
DEBUGF 1,"checksum: ptr=%x size=%u\n", esi, ecx |
|
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+8 |
DEBUGF 1,"TCP_output: failed\n" |
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 |
; ebx = error number |
; |
; OUT: eax = socket ptr |
; |
;------------------------- |
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 |
|
;;; TODO: update stats |
|
jmp TCP_close |
|
.no_syn_received: |
|
;;; TODO: update stats |
|
;;; TODO: check if error code is "Connection timed out' and handle accordingly |
|
mov [eax + SOCKET.errorcode], ebx |
|
jmp TCP_close |
|
|
;------------------------- |
; |
; TCP_close |
; |
; IN: eax = socket ptr |
; OUT: eax = socket ptr |
; |
;------------------------- |
align 4 |
TCP_close: |
|
DEBUGF 1,"TCP_close\n" |
|
;;; TODO: update RTT and mean deviation |
;;; TODO: update slow start threshold |
;;; TODO: release connection resources |
|
; Now, mark the socket as being disconnected |
|
mov [eax + SOCKET.state], 0 ;;; FIXME |
|
ret |
|
|
|
|
;--------------------------------------- |
; |
; The easy way to send an ACK/RST/keepalive segment |
; |
; TCP_respond_socket: |
; |
; IN: ebx = socket ptr |
; cl = flags |
; |
;-------------------------------------- |
align 4 |
TCP_respond_socket: |
|
DEBUGF 1,"TCP_respond_socket\n" |
|
;--------------------- |
; Create the IP packet |
|
push cx ebx |
mov eax, [ebx + IP_SOCKET.RemoteIP] |
mov ebx, [ebx + IP_SOCKET.LocalIP] |
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 the socket ptr |
|
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 |
|
;-------------------- |
; And send the segment |
|
call [ebx + NET_DEVICE.transmit] |
ret |
|
.error: |
DEBUGF 1,"TCP_respond failed\n" |
add esp, 2+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 |
jz .error |
pop esi cx |
|
push edx eax |
|
;--------------------------------------------------- |
; Fill in the TCP header by using a received 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 |
|
;--------------------- |
; Fill in the checksum |
|
.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 |
|
call [ebx + NET_DEVICE.transmit] |
ret |
|
.error: |
DEBUGF 1,"TCP_respond failed\n" |
add esp, 2+4 |
|
ret |
|
|
|
|
;--------------------------------------------------------------------------- |
; |
; TCP_API |