Subversion Repositories Kolibri OS

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;                                                              ;;

;; Copyright (C) KolibriOS team 2004-2008. All rights reserved. ;;

;; Distributed under terms of the GNU General Public License    ;;

;;                                                              ;;

;;  SOCKET.INC                                                  ;;

;;                                                              ;;

;;  Sockets constants, structures and functions                 ;;

;;                                                              ;;

;;  This file contains the following:                           ;;

;;    is_localport_unused                                       ;;

;;    get_free_socket                                           ;;

;;    socket_open                                               ;;

;;    socket_open_tcp                                           ;;

;;    socket_close                                              ;;

;;    socket_close_tcp                                          ;;

;;    socket_poll                                               ;;

;;    socket_status                                             ;;

;;    socket_read                                               ;;

;;    socket_write                                              ;;

;;    socket_write_tcp                                          ;;

;;                                                              ;;

;;                                                              ;;

;;  Changes history:                                            ;;

;;   22.09.2003 - [Mike Hibbett] : mikeh@oceanfree.net          ;;

;;   11.11.2006 - [Johnny_B] and [smb]                          ;;

;;                                                              ;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

$Revision: 1019 $

; socket data structure

struct SOCKET

  .PrevPtr	  dd ? ; pointer to previous socket in list

  .NextPtr	  dd ? ; pointer to next socket in list

  .Number	  dd ? ; socket number (unique within single process)

  .PID		  dd ? ; application process id

  .LocalIP	  dd ? ; local IP address

  .LocalPort	  dw ? ; local port

  .RemoteIP	  dd ? ; remote IP address

  .RemotePort	  dw ? ; remote port

  .OrigRemoteIP   dd ? ; original remote IP address (used to reset to LISTEN state)

  .OrigRemotePort dw ? ; original remote port (used to reset to LISTEN state)

  .rxDataCount	  dd ? ; rx data count

  .TCBState	  dd ? ; TCB state

  .TCBTimer	  dd ? ; TCB timer (seconds)

  .ISS		  dd ? ; initial send sequence

  .IRS		  dd ? ; initial receive sequence

  .SND_UNA	  dd ? ; sequence number of unack'ed sent packets

  .SND_NXT	  dd ? ; bext send sequence number to use

  .SND_WND	  dd ? ; send window

  .RCV_NXT	  dd ? ; next receive sequence number to use

  .RCV_WND	  dd ? ; receive window

  .SEG_LEN	  dd ? ; segment length

  .SEG_WND	  dd ? ; segment window

  .wndsizeTimer   dd ? ; window size timer

  .lock           dd ? ; lock mutex

  .rxData	  dd ? ; receive data buffer here

ends

; TCP opening modes

SOCKET_PASSIVE = 0

SOCKET_ACTIVE  = 1

; socket types

SOCK_STREAM = 1

SOCK_DGRAM  = 2

;; Allocate memory for socket data and put new socket into the list

; Newly created socket is initialized with calling PID and number and

; put into beginning of list (which is a fastest way).

;

; @return socket structure address in EAX

;;

proc net_socket_alloc stdcall uses ebx ecx edx edi

	stdcall kernel_alloc, SOCKETBUFFSIZE

	DEBUGF	1, "K : net_socket_alloc (0x%x)\n", eax

	; check if we can allocate needed amount of memory

	or	eax, eax

	jz	.exit

	; zero-initialize allocated memory

	push	eax

	mov	edi, eax

	mov	ecx, SOCKETBUFFSIZE / 4

	cld

	xor	eax, eax

	rep	stosd

	pop	eax

	; add socket to the list by changing pointers

	mov	ebx, net_sockets

	push	[ebx + SOCKET.NextPtr]

	mov	[ebx + SOCKET.NextPtr], eax

	mov	[eax + SOCKET.PrevPtr], ebx

	pop	ebx

	mov	[eax + SOCKET.NextPtr], ebx

	or	ebx, ebx

	jz	@f

	mov	[ebx + SOCKET.PrevPtr], eax

    @@: ; set socket owner PID to the one of calling process

	mov	ebx, [TASK_BASE]

	mov	ebx, [ebx + TASKDATA.pid]

	mov	[eax + SOCKET.PID], ebx

	; find first free socket number and use it

	;mov     edx, ebx

	mov	ebx, net_sockets

	xor	ecx, ecx

  .next_socket_number:

	inc	ecx

  .next_socket:

	mov	ebx, [ebx + SOCKET.NextPtr]

	or	ebx, ebx

	jz	.last_socket_number

	cmp	[ebx + SOCKET.Number], ecx

	jne	.next_socket

	;cmp     [ebx + SOCKET.PID], edx

	;jne     .next_socket

	mov	ebx, net_sockets

	jmp	.next_socket_number

  .last_socket_number:

	mov	[eax + SOCKET.Number], ecx

  .exit:

	ret

endp

;; Free socket data memory and pop socket off the list

;

; @param sockAddr is a socket structure address

;;

proc net_socket_free stdcall uses ebx ecx edx, sockAddr:DWORD

	mov	eax, [sockAddr]

	DEBUGF	1, "K : net_socket_free (0x%x)\n", eax

	; check if we got something similar to socket structure address

	or	eax, eax

	jz	.error

	; make sure sockAddr is one of the socket addresses in the list

	mov	ebx, net_sockets

	;mov     ecx, [TASK_BASE]

	;mov     ecx, [ecx + TASKDATA.pid]

  .next_socket:

	mov	ebx, [ebx + SOCKET.NextPtr]

	or	ebx, ebx

	jz	.error

	cmp	ebx, eax

	jne	.next_socket

	;cmp     [ebx + SOCKET.PID], ecx

	;jne     .next_socket

	; okay, we found the correct one

	; remove it from the list first, changing pointers

	mov	ebx, [eax + SOCKET.NextPtr]

	mov	eax, [eax + SOCKET.PrevPtr]

	mov	[eax + SOCKET.NextPtr], ebx

	or	ebx, ebx

	jz	@f

	mov	[ebx + SOCKET.PrevPtr], eax

    @@: ; and finally free the memory structure used

	stdcall kernel_free, [sockAddr]

	ret

  .error:

	DEBUGF	1, "K :   failed\n"

	ret

endp

;; Get socket structure address by its number

; Scan through sockets list to find the socket with specified number.

; This proc uses SOCKET.PID indirectly to check if socket is owned by

; calling process.

;

; @param sockNum is a socket number

; @return socket structure address or 0 (not found) in EAX

;;

proc net_socket_num_to_addr stdcall uses ebx ecx, sockNum:DWORD

	mov	eax, [sockNum]

	; check if we got something similar to socket number

	or	eax, eax

	jz	.error

	; scan through sockets list

	mov	ebx, net_sockets

	;mov     ecx, [TASK_BASE]

	;mov     ecx, [ecx + TASKDATA.pid]

  .next_socket:

	mov	ebx, [ebx + SOCKET.NextPtr]

	or	ebx, ebx

	jz	.error

	cmp	[ebx + SOCKET.Number], eax

	jne	.next_socket

	;cmp     [ebx + SOCKET.PID], ecx

	;jne     .next_socket

	; okay, we found the correct one

	mov	eax, ebx

	ret

  .error:

	xor	eax, eax

	ret

endp

;; Get socket number by its structure address

; Scan through sockets list to find the socket with specified address.

; This proc uses SOCKET.PID indirectly to check if socket is owned by

; calling process.

;

; @param sockAddr is a socket structure address

; @return socket number (SOCKET.Number) or 0 (not found) in EAX

;;

proc net_socket_addr_to_num stdcall uses ebx ecx, sockAddr:DWORD

	mov	eax, [sockAddr]

	; check if we got something similar to socket structure address

	or	eax, eax

	jz	.error

	; scan through sockets list

	mov	ebx, net_sockets

	;mov     ecx, [TASK_BASE]

	;mov     ecx, [ecx + TASKDATA.pid]

  .next_socket:

	mov	ebx, [ebx + SOCKET.NextPtr]

	or	ebx, ebx

	jz	.error

	cmp	ebx, eax

	jne	.next_socket

	;cmp     [ebx + SOCKET.PID], ecx

	;jne     .next_socket

	; okay, we found the correct one

	mov	eax, [ebx + SOCKET.Number]

	ret

  .error:

	xor	eax, eax

	ret

endp

;; [53.9] Check if local port is used by any socket in the system.

; Scan through sockets list, checking SOCKET.LocalPort.

; Useful when you want a to generate a unique local port number.

; This proc doesn't guarantee that after calling it and trying to use

; the port reported being free in calls to socket_open/socket_open_tcp it'll

; still be free or otherwise it'll still be used if reported being in use.

;

; @param BX is a port number

; @return 1 (port is free) or 0 (port is in use) in EAX

;;

proc is_localport_unused stdcall

	xchg	bl, bh

	; assume the return value is 'free'

	xor	eax, eax

	inc	al

	mov	edx, net_sockets

  .next_socket:

	mov	edx, [edx + SOCKET.NextPtr]

	or	edx, edx

	jz	.exit

	cmp	[edx + SOCKET.LocalPort], bx

	jne	.next_socket

	; return 'in use'

	dec	al

  .exit:

	ret

endp

;; [53.0] Open DGRAM socket (connectionless, unreliable)

;

; @param BX is local port number

; @param CX is remote port number

; @param EDX is remote IP address

; @return socket number or -1 (error) in EAX

;;

proc socket_open stdcall

	call	net_socket_alloc

	or	eax, eax

	jz	.error

	DEBUGF	1, "K : socket_open (0x%x)\n", eax

	push	eax

	xchg	bh, bl

	mov	[eax + SOCKET.LocalPort], bx

	xchg	ch, cl

	mov	[eax + SOCKET.RemotePort], cx

	mov	ebx, [stack_ip]

	mov	[eax + SOCKET.LocalIP], ebx

	mov	[eax + SOCKET.RemoteIP], edx

	;pop     eax      ; Get the socket number back, so we can return it

	stdcall net_socket_addr_to_num

	ret

  .error:

	DEBUGF	1, "K : socket_open (fail)\n"

	or	eax, -1

	ret

endp

;; [53.5] Open STREAM socket (connection-based, sequenced, reliable, two-way)

;

; @param BX is local port number

; @param CX is remote port number

; @param EDX is remote IP address

; @param ESI is open mode (SOCKET_ACTIVE, SOCKET_PASSIVE)

; @return socket number or -1 (error) in EAX

;;

proc socket_open_tcp stdcall

local sockAddr dd ?

	cmp	esi, SOCKET_PASSIVE

	jne	.skip_port_check

	push	ebx

	mov	eax, ebx

	xchg	al, ah

	mov	ebx, net_sockets

  .next_socket:

	mov	ebx, [ebx + SOCKET.NextPtr]

	or	ebx, ebx

	jz	.last_socket

	cmp	[ebx + SOCKET.TCBState], TCB_LISTEN

	jne	.next_socket

	cmp	[ebx + SOCKET.LocalPort], ax

	jne	.next_socket

	xchg	al, ah

	DEBUGF	1, "K : error: port %u is listened by 0x%x\n", ax, ebx

	pop	ebx

	jmp	.error

  .last_socket:

	pop	ebx

  .skip_port_check:

	call	net_socket_alloc

	or	eax, eax

	jz	.error

	DEBUGF	1, "K : socket_open_tcp (0x%x)\n", eax

	mov	[sockAddr], eax

	; TODO - check this works!

	;mov     [eax + SOCKET.wndsizeTimer], 0     ; Reset the window timer.

	xchg	bh, bl

	mov	[eax + SOCKET.LocalPort], bx

	xchg	ch, cl

	mov	[eax + SOCKET.RemotePort], cx

	mov	[eax + SOCKET.OrigRemotePort], cx

	mov	ebx, [stack_ip]

	mov	[eax + SOCKET.LocalIP], ebx

	mov	[eax + SOCKET.RemoteIP], edx

	mov	[eax + SOCKET.OrigRemoteIP], edx

	mov	ebx, TCB_LISTEN

	cmp	esi, SOCKET_PASSIVE

	je	@f

	mov	ebx, TCB_SYN_SENT

    @@: mov	[eax + SOCKET.TCBState], ebx		; Indicate the state of the TCB

	cmp	ebx, TCB_LISTEN

	je	.exit

	; Now, if we are in active mode, then we have to send a SYN to the specified remote port

	mov	eax, EMPTY_QUEUE

	call	dequeue

	cmp	ax, NO_BUFFER

	je	.exit

	push	eax

	mov	bl, TH_SYN

	xor	ecx, ecx

	stdcall build_tcp_packet, [sockAddr]

	mov	eax, NET1OUT_QUEUE

	mov	edx, [stack_ip]

	mov	ecx, [sockAddr]

	cmp	edx, [ecx + SOCKET.RemoteIP]

	jne	.not_local

	mov	eax, IPIN_QUEUE

  .not_local:

	; Send it.

	pop	ebx

	call	queue

	mov	esi, [sockAddr]

	; increment SND.NXT in socket

	add	esi, SOCKET.SND_NXT

	call	inc_inet_esi

  .exit:

	; Get the socket number back, so we can return it

	stdcall net_socket_addr_to_num, [sockAddr]

	ret

  .error:

	DEBUGF	1, "K : socket_open_tcp (fail)\n"

	or	eax, -1

	ret

endp

;; [53.1] Close DGRAM socket

;

; @param EBX is socket number

; @return 0 (closed successfully) or -1 (error) in EAX

;;

proc socket_close stdcall

	DEBUGF	1, "K : socket_close (0x%x)\n", ebx

	stdcall net_socket_num_to_addr, ebx

	or	eax, eax

	jz	.error

	stdcall net_socket_free, eax

	xor	eax, eax

	ret

  .error:

	DEBUGF	1, "K : socket_close (fail)\n"

	or	eax, -1

	ret

endp

;; [53.8] Close STREAM socket

; Closing TCP sockets takes time, so when you get successful return code

; from this function doesn't always mean that socket is actually closed.

;

; @param EBX is socket number

; @return 0 (closed successfully) or -1 (error) in EAX

;;

proc socket_close_tcp stdcall

local sockAddr dd ?

	DEBUGF	1, "K : socket_close_tcp (0x%x)\n", ebx

	; first, remove any resend entries

	pusha

	mov	esi, resendQ

	mov	ecx, 0

  .next_resendq:

	cmp	ecx, NUMRESENDENTRIES

	je	.last_resendq	    ; None left

	cmp	[esi + 4], ebx

	je	@f		    ; found one

	inc	ecx

	add	esi, 8

	jmp	.next_resendq

    @@: mov	dword[esi + 4], 0

	inc	ecx

	add	esi, 8

	jmp	.next_resendq

  .last_resendq:

	popa

	stdcall net_socket_num_to_addr, ebx

	or	eax, eax

	jz	.error

	mov	ebx, eax

	mov	[sockAddr], eax

	cmp	[ebx + SOCKET.TCBState], TCB_LISTEN

	je	.destroy_tcb

	cmp	[ebx + SOCKET.TCBState], TCB_SYN_SENT

	je	.destroy_tcb

	; Now construct the response, and queue for sending by IP

	mov	eax, EMPTY_QUEUE

	call	dequeue

	cmp	ax, NO_BUFFER

	je	.error

	push	eax

	mov	bl, TH_FIN

	xor	ecx, ecx

	xor	esi, esi

	stdcall build_tcp_packet, [sockAddr]

	mov	 ebx, [sockAddr]

	; increament SND.NXT in socket

	lea	esi, [ebx + SOCKET.SND_NXT]

	call	inc_inet_esi

	; Get the socket state

	mov	eax, [ebx + SOCKET.TCBState]

	cmp	eax, TCB_SYN_RECEIVED

	je	.fin_wait_1

	cmp	eax, TCB_ESTABLISHED

	je	.fin_wait_1

	; assume CLOSE WAIT

	; Send a fin, then enter last-ack state

	mov	[ebx + SOCKET.TCBState], TCB_LAST_ACK

	jmp	.send

  .fin_wait_1:

	; Send a fin, then enter finwait2 state

	mov	[ebx + SOCKET.TCBState], TCB_FIN_WAIT_1

  .send:

	mov	eax, NET1OUT_QUEUE

	mov	edx, [stack_ip]

	mov	ecx, [sockAddr]

	cmp	edx, [ecx + SOCKET.RemoteIP]

	jne	.not_local

	mov	eax, IPIN_QUEUE

  .not_local:

	; Send it.

	pop	ebx

	call	queue

	jmp	.exit

  .destroy_tcb:

	; Clear the socket variables

	stdcall net_socket_free, ebx

  .exit:

	xor	eax, eax

	ret

  .error:

	DEBUGF	1, "K : socket_close_tcp (fail)\n"

	or	eax, -1

	ret

endp

;; [53.2] Poll socket

;

; @param EBX is socket number

; @return count or bytes in rx buffer or 0 (error) in EAX

;;

proc socket_poll stdcall

;        DEBUGF  1, "socket_poll(0x%x)\n", ebx

	stdcall net_socket_num_to_addr, ebx

	or	eax, eax

	jz	.error

	mov	eax, [eax + SOCKET.rxDataCount]

	ret

  .error:

	xor	eax, eax

	ret

endp

;; [53.6] Get socket TCB state

;

; @param EBX is socket number

; @return socket TCB state or 0 (error) in EAX

;;

proc socket_status stdcall

;;       DEBUGF  1, "socket_status(0x%x)\n", ebx

	stdcall net_socket_num_to_addr, ebx

	or	eax, eax

	jz	.error

	mov	eax, [eax + SOCKET.TCBState]

	ret

  .error:

	xor	eax, eax

	ret

endp

;; [53.3] Get one byte from rx buffer

; This function can return 0 in two cases: if there's one byte read and

; non left, and if an error occured. Behavior should be changed and function

; shouldn't be used for now. Consider using [53.11] instead.

;

; @param EBX is socket number

; @return number of bytes left in rx buffer or 0 (error) in EAX

; @return byte read in BL

;;

proc socket_read stdcall

;        DEBUGF  1, "socket_read(0x%x)\n", ebx

	stdcall net_socket_num_to_addr, ebx

	or	eax, eax

	jz	.error

	lea	ebx, [eax + SOCKET.lock]

	call	wait_mutex

	mov	ebx, eax

	mov	eax, [ebx + SOCKET.rxDataCount] 	; get count of bytes

	test	eax, eax

	jz	.error_release

	dec	eax

	mov	esi, ebx				; esi is address of socket

	mov	[ebx + SOCKET.rxDataCount], eax 	; store new count

	movzx	eax, byte[ebx + SOCKET.rxData]		; get the byte

	mov	ecx, SOCKETBUFFSIZE - SOCKET.rxData - 1

	lea	edi, [esi + SOCKET.rxData]

	lea	esi, [edi + 1]

	cld

	push	ecx

	shr	ecx, 2

	rep	movsd

	pop	ecx

	and	ecx, 3

	rep	movsb

	mov	[ebx + SOCKET.lock], 0

	mov	ebx, eax

	ret

  .error_release:

	mov	[ebx + SOCKET.lock], 0

  .error:

	xor	ebx, ebx

	ret

endp

;; [53.11] Get specified number of bytes from rx buffer

; Number of bytes in rx buffer can be less than requested size. In this case,

; only available number of bytes is read.

; This function can return 0 in two cases: if there's no data to read, and if

; an error occured. Behavior should be changed.

;

; @param EBX is socket number

; @param ECX is pointer to application buffer

; @param EDX is application buffer size (number of bytes to read)

; @return number of bytes read or 0 (error) in EAX

;;

proc socket_read_packet stdcall

;        DEBUGF  1, "socket_read_packet(0x%x)\n", ebx

	stdcall net_socket_num_to_addr, ebx		   ; get real socket address

	or	eax, eax

	jz	.error

	lea	ebx, [eax + SOCKET.lock]

	call	wait_mutex

	mov	ebx, eax

	mov	eax, [ebx + SOCKET.rxDataCount] 	   ; get count of bytes

	test	eax, eax				   ; if count of bytes is zero..

	jz	.exit					   ; exit function (eax will be zero)

	test	edx, edx				   ; if buffer size is zero, copy all data

	jz	.copy_all_bytes

	cmp	edx, eax				   ; if buffer size is larger then the bytes of data, copy all data

	jge	.copy_all_bytes

	sub	eax, edx				   ; store new count (data bytes in buffer - bytes we're about to copy)

	mov	[ebx + SOCKET.rxDataCount], eax 	   ;

	push	eax

	mov	eax, edx				   ; number of bytes we want to copy must be in eax

	call	.start_copy				   ; copy to the application

	mov	esi, ebx				   ; now we're going to copy the remaining bytes to the beginning

	add	esi, SOCKET.rxData			   ; we dont need to copy the header

	mov	edi, esi				   ; edi is where we're going to copy to

	add	esi, edx				   ; esi is from where we copy

	pop	ecx					   ; count of bytes we have left

	push	ecx					   ; push it again so we can re-use it later

	shr	ecx, 2					   ; divide eax by 4

	cld

	rep	movsd					   ; copy all full dwords

	pop	ecx

	and	ecx, 3

	rep	movsb					   ; copy remaining bytes

  .exit:

	mov	[ebx + SOCKET.lock], 0

	ret						   ; at last, exit

  .error:

	xor	eax, eax

	ret

  .copy_all_bytes:

	xor	esi, esi

	mov	[ebx + SOCKET.rxDataCount], esi 	   ; store new count (zero)

	call	.start_copy

	mov	[ebx + SOCKET.lock], 0

	ret

  .start_copy:

	mov	edi, ecx

	mov	esi, ebx

	add	esi, SOCKET.rxData			   ; we dont need to copy the header

	mov	ecx, eax				   ; eax is count of bytes

	push	ecx

	shr	ecx, 2					   ; divide eax by 4

	cld						   ; copy all full dwords

	rep	movsd

	pop	ecx

	and	ecx, 3

	rep	movsb					   ; copy the rest bytes

	retn						   ; exit, or go back to shift remaining bytes if any

endp

;; [53.4] Send data through DGRAM socket

;

; @param EBX is socket number

; @param ECX is application data size (number of bytes to send)

; @param EDX is pointer to application data buffer

; @return 0 (sent successfully) or -1 (error) in EAX

;;

proc socket_write stdcall

;        DEBUGF  1, "socket_write(0x%x)\n", ebx

	stdcall net_socket_num_to_addr, ebx		   ; get real socket address

	or	eax, eax

	jz	.error

	mov	ebx, eax

	mov	eax, EMPTY_QUEUE

	call	dequeue

	cmp	ax, NO_BUFFER

	je	.error

	; Save the queue entry number

	push	eax

	; save the pointers to the data buffer & size

	push	edx

	push	ecx

	; convert buffer pointer eax to the absolute address

	mov	ecx, IPBUFFSIZE

	mul	ecx

	add	eax, IPbuffs

	mov	edx, eax

	; So, ebx holds the socket ptr, edx holds the IPbuffer ptr

	; Fill in the IP header (some data is in the socket descriptor)

	mov	eax, [ebx + SOCKET.LocalIP]

	mov	[edx + IP_PACKET.SourceAddress], eax

	mov	eax, [ebx + SOCKET.RemoteIP]

	mov	[edx + IP_PACKET.DestinationAddress], eax

	mov	[edx + IP_PACKET.VersionAndIHL], 0x45

	mov	[edx + IP_PACKET.TypeOfService], 0

	pop	eax		      ; Get the UDP data length

	push	eax

	add	eax, 20 + 8	      ; add IP header and UDP header lengths

	xchg	al, ah

	mov	[edx + IP_PACKET.TotalLength], ax

	xor	eax, eax

	mov	[edx + IP_PACKET.Identification], ax

	mov	[edx + IP_PACKET.FlagsAndFragmentOffset], 0x0040

	mov	[edx + IP_PACKET.TimeToLive], 0x20

	mov	[edx + IP_PACKET.Protocol], PROTOCOL_UDP

	; Checksum left unfilled

	mov	[edx + IP_PACKET.HeaderChecksum], ax

	; Fill in the UDP header (some data is in the socket descriptor)

	mov	ax, [ebx + SOCKET.LocalPort]

	mov	[edx + 20 + UDP_PACKET.SourcePort], ax

	mov	ax, [ebx + SOCKET.RemotePort]

	mov	[edx + 20 + UDP_PACKET.DestinationPort], ax

	pop	eax

	push	eax

	add	eax, 8

	xchg	al, ah

	mov	[edx + 20 + UDP_PACKET.Length], ax

	; Checksum left unfilled

	xor	eax, eax

	mov	[edx + 20 + UDP_PACKET.Checksum], ax

	pop	ecx		     ; count of bytes to send

	mov	ebx, ecx	     ; need the length later

	pop	eax		     ; get callers ptr to data to send

	; Get the address of the callers data

	mov	edi, [TASK_BASE]

	add	edi, TASKDATA.mem_start

	add	eax, [edi]

	mov	esi, eax

	mov	edi, edx

	add	edi, 28

	cld

	rep	movsb		    ; copy the data across

	; we have edx as IPbuffer ptr.

	; Fill in the UDP checksum

	; First, fill in pseudoheader

	mov	eax, [edx + IP_PACKET.SourceAddress]

	mov	[pseudoHeader], eax

	mov	eax, [edx + IP_PACKET.DestinationAddress]

	mov	[pseudoHeader + 4], eax

	mov	word[pseudoHeader + 8], PROTOCOL_UDP shl 8 + 0	    ; 0 + protocol

	add	ebx, 8

	mov	eax, ebx

	xchg	al, ah

	mov	[pseudoHeader + 10], ax

	mov	eax, pseudoHeader

	mov	[checkAdd1], eax

	mov	[checkSize1], word 12

	mov	eax, edx

	add	eax, 20

	mov	[checkAdd2], eax

	mov	eax, ebx

	mov	[checkSize2], ax      ; was eax!! mjh 8/7/02

	call	checksum

	; store it in the UDP checksum ( in the correct order! )

	mov	ax, [checkResult]

	; If the UDP checksum computes to 0, we must make it 0xffff

	; (0 is reserved for 'not used')

	test	ax, ax

	jnz	@f

	mov	ax, 0xffff

    @@: xchg	al, ah

	mov	[edx + 20 + UDP_PACKET.Checksum], ax

	; Fill in the IP header checksum

	GET_IHL ecx,edx 	     ; get IP-Header length

	stdcall checksum_jb,edx,ecx  ; buf_ptr, buf_size

	xchg	al, ah

	mov	[edx + IP_PACKET.HeaderChecksum], ax

	; Check destination IP address.

	; If it is the local host IP, route it back to IP_RX

	pop	ebx

	mov	eax, NET1OUT_QUEUE

	mov	ecx, [edx + SOCKET.RemoteIP]

	mov	edx, [stack_ip]

	cmp	edx, ecx

	jne	.not_local

	mov	eax, IPIN_QUEUE

  .not_local:

	; Send it.

	call	queue

	xor	eax, eax

	ret

  .error:

	or	eax, -1

	ret

endp

;; [53.7] Send data through STREAM socket

;

; @param EBX is socket number

; @param ECX is application data size (number of bytes to send)

; @param EDX is pointer to application data buffer

; @return 0 (sent successfully) or -1 (error) in EAX

;;

proc socket_write_tcp stdcall

local sockAddr dd ?

;        DEBUGF  1, "socket_write_tcp(0x%x)\n", ebx

	stdcall net_socket_num_to_addr, ebx

	or	eax, eax

	jz	.error

	mov	ebx, eax

	mov	[sockAddr], ebx

	; If the sockets window timer is nonzero, do not queue packet

	cmp	[ebx + SOCKET.wndsizeTimer], 0

	jne	.error

	mov	eax, EMPTY_QUEUE

	call	dequeue

	cmp	ax, NO_BUFFER

	je	.error

	push	eax

	; Get the address of the callers data

	mov	edi, [TASK_BASE]

	add	edi, TASKDATA.mem_start

	add	edx, [edi]

	mov	esi, edx

	pop	eax

	push	eax

	push	ecx

	mov	bl, TH_ACK

	stdcall build_tcp_packet, [sockAddr]

	pop	ecx

	; Check destination IP address.

	; If it is the local host IP, route it back to IP_RX

	pop	ebx

	push	ecx

	mov	eax, NET1OUT_QUEUE

	mov	edx, [stack_ip]

	mov	ecx, [sockAddr]

	cmp	edx, [ecx + SOCKET.RemoteIP]

	jne	.not_local

	mov	eax, IPIN_QUEUE

  .not_local:

	pop	ecx

	push	ebx		    ; save ipbuffer number

	call	queue

	mov	esi, [sockAddr]

	; increament SND.NXT in socket

	; Amount to increment by is in ecx

	add	esi, SOCKET.SND_NXT

	call	add_inet_esi

	pop	ebx

	; Copy the IP buffer to a resend queue

	; If there isn't one, dont worry about it for now

	mov	esi, resendQ

	mov	ecx, 0

  .next_resendq:

	cmp	ecx, NUMRESENDENTRIES

	je	.exit		   ; None found

	cmp	dword[esi + 4], 0

	je	@f		   ; found one

	inc	ecx

	add	esi, 8

	jmp	.next_resendq

    @@: push	ebx

	; OK, we have a buffer descriptor ptr in esi.

	; resend entry # in ecx

	;  Populate it

	;  socket #

	;  retries count

	;  retry time

	;  fill IP buffer associated with this descriptor

	stdcall net_socket_addr_to_num, [sockAddr]

	mov	[esi + 4], eax

	mov	byte[esi + 1], TCP_RETRIES

	mov	word[esi + 2], TCP_TIMEOUT

	inc	ecx

	; Now get buffer location, and copy buffer across. argh! more copying,,

	mov	edi, resendBuffer - IPBUFFSIZE

    @@: add	edi, IPBUFFSIZE

	loop	@b

	; we have dest buffer location in edi

	pop	eax

	; convert source buffer pointer eax to the absolute address

	mov	ecx, IPBUFFSIZE

	mul	ecx

	add	eax, IPbuffs

	mov	esi, eax

	; do copy

	mov	ecx, IPBUFFSIZE

	cld

	rep	movsb

  .exit:

	xor	eax, eax

	ret

  .error:

	or	eax, -1

	ret

endp