Subversion Repositories Kolibri OS

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

;;                                                                 ;;

;; Copyright (C) KolibriOS team 2004-2009. All rights reserved.    ;;

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

;;                                                                 ;;

;;  SOCKET.INC                                                     ;;

;;                                                                 ;;

;;    Written by hidnplayr@kolibrios.org                           ;;

;;    based on code by mike.dld                                    ;;

;;                                                                 ;;

;;          GNU GENERAL PUBLIC LICENSE                             ;;

;;             Version 2, June 1991                                ;;

;;                                                                 ;;

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

$Revision: 1335 $

struct	SOCKET_head

	 .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

	 .Domain		dd ? ; INET/UNIX/..

	 .Type			dd ? ; RAW/UDP/TCP/...

	 .Protocol		dd ? ; ICMP/IPv4/ARP/

	 .lock			dd ? ; lock mutex

	 .errorcode		dd ?

	 .end:

ends

struct	IPv4_SOCKET

	 .LocalIP		dd ?

	 .RemoteIP		dd ?

	 .SequenceNumber	dd ?

	; todo: add options (for func 8 and 9)

	 .end:

ends

struct	TCP_SOCKET

	 .LocalPort		dw ? ; In INET byte order

	 .RemotePort		dw ? ; In INET byte order

	 .backlog		dw ? ; Backlog

	 .backlog_cur		dw ? ; current size of queue for un-accept-ed connections

	 .last_ack_number	dd ? ; used only to let application know that ACK has been received

					; todo: may be use SND_UNA instead

					; todo: may be use events which allow additional information instead

					; todo: may be count acknowledged bytes (at least it has obvious sense)

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

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

	 .wndsizeTimer		dd ? ; window size timer

	; Transmission control block

	 .state 		dd ? ; TCB state

	 .timer 		dd ? ; TCB timer (seconds)

	 .ISS			dd ? ; initial send sequence number

	 .IRS			dd ? ; initial receive sequence number

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

	 .SND_NXT		dd ? ; next 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

	 .flags 		db ? ; packet flags

	 .end:

ends

struct	UDP_SOCKET

	 .LocalPort		dw ? ; In INET byte order

	 .RemotePort		dw ? ; In INET byte order

	 .firstpacket		db ?

	 .end:

ends

struct	ICMP_SOCKET

	.Identifier		dw ? ;

	.end:

ends

struct	IPC_SOCKET

	.ConnectedTo		dd ? ; Socket number of other socket this one is connected to

	.end:

ends

struct	socket_queue_entry

	.data_ptr	dd ?

	.data_size	dd ?

	.offset 	dd ?

	.size:

ends

MAX_backlog		equ 20	     ; backlog for stream sockets

SOCKETBUFFSIZE		equ 4096     ; in bytes

SOCKET_QUEUE_SIZE	equ 10	     ; maximum number ofincoming packets queued for 1 socket

SOCKET_QUEUE_LOCATION	equ 2048     ; the incoming packet queue for sockets is placed in the socket struct itself, at this location from start

uglobal

	net_sockets	rd 2

	last_UDP_port	dw ? ; These values give the number of the last used ephemeral port

	last_TCP_port	dw ? ;

endg

;-----------------------------------------------------------------

;

; SOCKET_init

;

;  -

;

;  IN:  /

;  OUT: /

;

;-----------------------------------------------------------------

align 4

socket_init:

	mov	[net_sockets], 0

	mov	[net_sockets + 4], 0

	mov	[last_UDP_port], MIN_EPHEMERAL_PORT

	mov	[last_TCP_port], MIN_EPHEMERAL_PORT

	ret

;-----------------------------------------------------------------

;

; Socket API (function 74)

;

;-----------------------------------------------------------------

align 4

sys_socket:

	and	ebx, 0x000000FF ; should i remove this line ?

	cmp	bl , 8		; highest possible number

	jg	s_error

	lea	ebx, [.table + 4*ebx]

	jmp	dword [ebx]

.table:

	dd	socket_open	; 0

	dd	socket_close	; 1

	dd	socket_bind	; 2

	dd	socket_listen	; 3

	dd	socket_connect	; 4

	dd	socket_accept	; 5

	dd	socket_send	; 6

	dd	socket_recv	; 7

	dd	socket_get_opt	; 8

;        dd      socket_set_opt  ; 9

s_error:

	mov	dword [esp+32],-1

	ret

;-----------------------------------------------------------------

;

; SOCKET_open

;

;

;  IN:  domain in ecx

;       type in edx

;       protocol in esi

;  OUT: eax is socket num, -1 on error

;

;-----------------------------------------------------------------

align 4

socket_open:

	DEBUGF	1,"socket_open: domain: %u, type: %u",ecx, edx

	call	net_socket_alloc

	or	eax, eax

	jz	s_error

	mov	[eax + SOCKET_head.Domain], ecx

	mov	[eax + SOCKET_head.Type], edx

	mov	[eax + SOCKET_head.Protocol], esi

	cmp	ecx, AF_INET4

	je	.af_inet4

	jmp	.done

  .af_inet4:

	cmp	edx, IP_PROTO_TCP

	je	.tcp

	jmp	.done

  .tcp:

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_CLOSED

	pseudo_random ebx

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.ISS], ebx

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.SND_NXT], ebx

  .done:

	stdcall net_socket_addr_to_num, eax

	DEBUGF	1,", socketnumber: %u\n", eax

	mov	[esp+32], eax

	ret

;-----------------------------------------------------------------

;

; SOCKET_bind

;

;  IN:  socket number in ecx

;       pointer to sockaddr struct in edx

;       length of that struct in esi

;  OUT: 0 on success

;

;-----------------------------------------------------------------

align 4

socket_bind:

	DEBUGF	1,"Socket_bind: socknum: %u sockaddr: %x, length: %u, ",ecx,edx,esi

	stdcall net_socket_num_to_addr, ecx

	cmp	eax, -1

	jz	s_error

	cmp	esi, 2

	jl	s_error

	cmp	word [edx], AF_INET4

	je	.af_inet4

	cmp	word [edx], AF_UNIX

	je	.af_unix

	jmp	s_error

  .af_unix:

	; TODO: write code here

	mov	dword [esp+32],0

	ret

  .af_inet4:

	cmp	esi, 6

	jl	s_error

	mov	ecx, [eax + SOCKET_head.Type]

	mov	bx, word [edx + 2]

	DEBUGF	1,"local port: %x ",bx

	test	bx, bx

	jz	.find_free

	call	socket_check_port

	test	bx, bx

	je	s_error

	jmp	.got_port

    .find_free:

	call	socket_find_port

	test	bx, bx

	je	s_error

    .got_port:

	DEBUGF	1,"using port: %x ",bx

	mov	word [eax + SOCKET_head.end + IPv4_SOCKET.end + UDP_SOCKET.LocalPort], bx

	mov	ebx, dword [edx + 4]

	mov	dword [eax + SOCKET_head.end + IPv4_SOCKET.LocalIP], ebx

	DEBUGF	1,"local ip: %u.%u.%u.%u\n",\

	[eax + SOCKET_head.end + IPv4_SOCKET.LocalIP + 0]:1,[eax + SOCKET_head.end + IPv4_SOCKET.LocalIP + 1]:1,\

	[eax + SOCKET_head.end + IPv4_SOCKET.LocalIP + 2]:1,[eax + SOCKET_head.end + IPv4_SOCKET.LocalIP + 3]:1

	mov	dword [esp+32],0

	ret

;-----------------------------------------------------------------

;

; SOCKET_connect

;

;

;  IN:  socket number in ecx

;       pointer to sockaddr struct in edx

;       length of that struct in esi

;  OUT: 0 on success

;

;-----------------------------------------------------------------

align 4

socket_connect:

	DEBUGF	1,"Socket_connect: socknum: %u sockaddr: %x, length: %u,",ecx,edx,esi

	stdcall net_socket_num_to_addr, ecx

	cmp	eax, -1

	jz	s_error

	cmp	esi, 8

	jl	s_error

	cmp	word [edx], AF_INET4

	je	.af_inet4

	jmp	s_error

  .af_inet4:

	cmp	[eax + SOCKET_head.Type], IP_PROTO_UDP

	je	.udp

	cmp	[eax + SOCKET_head.Type], IP_PROTO_TCP

	je	.tcp

	jmp	s_error

  .udp:

	mov	bx , word [edx + 2]

	mov	word [eax + SOCKET_head.end + IPv4_SOCKET.end + UDP_SOCKET.RemotePort], bx

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + UDP_SOCKET.firstpacket], 0

	DEBUGF	1,"remote port: %x ",bx

	mov	ebx, dword [edx + 4]

	mov	dword [eax + SOCKET_head.end + IPv4_SOCKET.RemoteIP], ebx

	DEBUGF	1,"remote ip: %u.%u.%u.%u\n",[edx+4]:1,[edx+5]:1,[edx+6]:1,[edx+7]:1

	mov	dword [esp+32],0

	ret

  .tcp:

	; TODO: set sequence number to random value

	lea	ebx, [eax + SOCKET_head.lock]

	call	wait_mutex

	; fill in remote port and IP

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.wndsizeTimer], 0	   ; Reset the window timer.

											   ; TODO: figure out WTF this is

	mov	bx , word [edx + 2]

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.RemotePort], bx

	DEBUGF	1,"remote port: %x ",bx

	mov	ebx, dword [edx + 4]

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.RemoteIP], ebx

	; check if local port and IP is ok

	cmp	[eax + SOCKET_head.end + IPv4_SOCKET.LocalIP], 0

	jne	@f

	push	[IP_LIST]	    ; device zero = default

	pop	[eax + SOCKET_head.end + IPv4_SOCKET.LocalIP]

       @@:

	cmp	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.LocalPort], 0

	jne	@f

	mov	ecx, [eax + SOCKET_head.Type]

	call	socket_find_port

	test	bx, bx

	jz	s_error

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.LocalPort], bx

       @@:

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_SYN_SENT

	; now say hello to the remote tcp socket

	mov	bl, TH_SYN

	xor	ecx, ecx

	call	TCP_send

	mov	dword [esp+32],0

	ret

;-----------------------------------------------------------------

;

; SOCKET_listen

;

;

;  IN:  socket number in ecx

;       backlog in edx

;  OUT: eax is socket num, -1 on error

;

;-----------------------------------------------------------------

align 4

socket_listen:

	DEBUGF	1,"Socket_listen: socknum: %u backlog: %u\n",ecx,edx

	stdcall net_socket_num_to_addr, ecx

	cmp	eax, -1

	jz	s_error

	cmp	word [eax + SOCKET_head.Domain], AF_INET4

	jne	s_error

	cmp	[eax + SOCKET_head.Type], IP_PROTO_TCP

	jne	s_error

	cmp	edx, MAX_backlog

	jb	.ok

	mov	dx , MAX_backlog

  .ok:

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.backlog], dx

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_LISTEN

	mov	dword [esp+32], 0

	ret

;-----------------------------------------------------------------

;

; SOCKET_accept

;

;

;  IN:  socket number in ecx

;       addr in edx

;       addrlen in esi

;  OUT: eax is socket num, -1 on error

;

;-----------------------------------------------------------------

align 4

socket_accept:

	DEBUGF	1,"Socket_accept: socknum: %u sockaddr: %x, length: %u\n",ecx,edx,esi

	stdcall net_socket_num_to_addr, ecx

	or	eax, eax

	jz	s_error

	mov	esi, eax

	cmp	word [esi + SOCKET_head.Domain], AF_INET4

	je	.af_inet4

	jmp	s_error

  .af_inet4:

	cmp	[esi + SOCKET_head.Type], IP_PROTO_TCP

	je	.tcp

	jmp	s_error

  .tcp:

	lea	ebx, [esi + SOCKET_head.lock]

	call	wait_mutex

	movzx	eax, [esi + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.backlog_cur]

	test	eax, eax

	jz	.unlock_err

	dec	[esi + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.backlog_cur]

	mov	eax, [eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.end + (eax-1)*4]

	mov	[esi + SOCKET_head.lock], 0

	stdcall net_socket_addr_to_num, eax

	mov	[esp+32], eax

	ret

  .unlock_err:

	mov	[esi + SOCKET_head.lock], 0

	jmp	s_error

;-----------------------------------------------------------------

;

; SOCKET_close

;

;

;  IN:  socket number in ecx

;  OUT: eax is socket num, -1 on error

;

;-----------------------------------------------------------------

align 4

socket_close:

	DEBUGF	1,"Socket_close: socknum: %u\n",ecx

	stdcall net_socket_num_to_addr, ecx

	or	eax, eax

	jz	s_error

	cmp	[eax + SOCKET_head.Domain], AF_INET4

	jne	s_error

	cmp	[eax + SOCKET_head.Type], IP_PROTO_UDP

	je	.udp

	cmp	[eax + SOCKET_head.Type], IP_PROTO_ICMP

	je	.icmp

	cmp	[eax + SOCKET_head.Type], IP_PROTO_TCP

	je	.tcp

	jmp	s_error

  .udp:

	stdcall net_socket_free, eax

	mov	dword [esp+32],0

	ret

  .icmp:

	ret

  .tcp:

	mov	dword [esp+32],0

	; first, remove all resend entries for this socket

	call	TCP_remove_socket

;        cmp     [eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_LISTEN

;        je      .destroy_tcb

;        cmp     [eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_SYN_SENT

;        je      .destroy_tcb

;        cmp     [eac + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_CLOSED

;        je      .destroy_tcb

	cmp	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_SYN_RECEIVED

	je	.fin_wait

	cmp	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_ESTABLISHED

	je	.fin_wait

	cmp	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_CLOSE_WAIT

	je	.last_ack

	stdcall net_socket_free, ebx

	ret

  .last_ack:

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_LAST_ACK

	jmp	.send_fin

  .fin_wait:

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state], TCB_FIN_WAIT_1

  .send_fin:

	mov	bl, TH_FIN + TH_ACK

	xor	ecx, ecx

	call	TCP_send

	ret

;-----------------------------------------------------------------

;

; SOCKET_receive

;

;

;  IN:  socket number in ecx

;       addr to buffer in edx

;       length of buffer in esi

;       flags in edi

;  OUT: eax is number of bytes copied, -1 on error

;

;-----------------------------------------------------------------

align 4

socket_recv:

	DEBUGF	1,"Socket_receive: socknum: %u bufaddr: %x, buflength: %u, flags: %x\n",ecx,edx,esi,edi

	stdcall net_socket_num_to_addr, ecx		   ; get real socket address

	or	eax, eax

	jz	s_error

	mov	ebx, esi

	DEBUGF	1,"Socket pointer: %x\n", eax

	get_from_queue (eax + SOCKET_QUEUE_LOCATION), SOCKET_QUEUE_SIZE, socket_queue_entry.size, s_error	; destroys esi and ecx

	mov	edi, edx					; addr to buffer

	mov	ecx, [esi + socket_queue_entry.data_size]

	DEBUGF	1,"Got %u bytes of data\n", ecx

	cmp	ecx, ebx

	jle	.large_enough

	DEBUGF	1,"Buffer too small...\n"

	jmp	s_error

  .large_enough:

	push	[esi + socket_queue_entry.data_ptr]		; save the buffer addr so we can clear it later

	mov	esi, [esi + socket_queue_entry.offset]

	add	esi, [esp]					; calculate the real data offset

	DEBUGF	1,"Source buffer: %x, real addr: %x\n", [esp], esi

	mov	dword[esp+32+4], ecx				; return number of bytes copied

	shr	ecx, 1

	jnc	.nb

	movsb

.nb:	shr	ecx, 1

	jnc	.nw

	movsw

.nw:	test	ecx, ecx

	jz	.nd

	rep	movsd

.nd:

	call	kernel_free					; todo: check if ALL applications had the chance to receive data

	ret

;-----------------------------------------------------------------

;

; SOCKET_send

;

;

;  IN:  socket number in ecx

;       pointer to data in edx

;       datalength in esi

;       flags in edi

;  OUT: -1 on error

;

;-----------------------------------------------------------------

align 4

socket_send:

	DEBUGF	1,"Socket_send: socknum: %u sockaddr: %x, length: %u, flags: %x, ",ecx,edx,esi,edi

	stdcall net_socket_num_to_addr, ecx		   ; get real socket address

	or	eax, eax

	jz	s_error

	cmp	word [eax + SOCKET_head.Domain], AF_INET4

	je	.af_inet4

	jmp	s_error

  .af_inet4:

	DEBUGF	1,"Socket type:%u\n", [eax + SOCKET_head.Type]:4

	cmp	[eax + SOCKET_head.Type], IP_PROTO_TCP

	je	.tcp

	cmp	[eax + SOCKET_head.Type], IP_PROTO_UDP

	je	.udp

	cmp	[eax + SOCKET_head.Type], SOCK_RAW

	je	.raw

	jmp	s_error

  .udp:

	DEBUGF	1,"type: UDP, "

	cmp	[eax + SOCKET_head.end + IPv4_SOCKET.end + UDP_SOCKET.LocalPort],0

	jne	@f

	push	esi

	mov	ecx, [eax + SOCKET_head.Type]

	call	socket_find_port

	test	bx, bx

	pop	esi

	je	s_error

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + UDP_SOCKET.LocalPort], bx

     @@:

	mov	ecx, esi

	mov	esi, edx

	call	UDP_socket_send

	and	dword [esp+32], 0

	ret

  .tcp:

	cmp	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.LocalPort],0

	jne	@f

	push	esi

	mov	ecx, [eax + SOCKET_head.Type]

	call	socket_find_port

	test	bx, bx

	pop	esi

	je	s_error

	mov	[eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.LocalPort], bx

     @@:

	mov	ecx, esi

	mov	esi, edx

	mov	bl, TH_PUSH + TH_ACK

	call	TCP_send

	mov	[esp+32], eax

	ret

  .raw:

	cmp	[eax + SOCKET_head.Protocol], IP_PROTO_IP

	je	.raw_ip

	cmp	[eax + SOCKET_head.Protocol], IP_PROTO_ICMP

	je	.raw_icmp

	jmp	s_error

  .raw_ip:

	;;;;;;

	mov	[esp+32], eax

	ret

  .raw_icmp:

;        sub     ecx, ICMP_Packet.Data

;        mov     esi, edx

;        push    ax

;        call    IPv4_get_frgmnt_num

;        mov     dx, ax

;        pop     ax

;        shl     edx, 16

;        mov     dh , [esi + ICMP_Packet.Type]

;        mov     dl , [esi + ICMP_Packet.Code]

;        mov     di , [esi + ICMP_Packet.Identifier]

;        mov     [eax + SOCKET.LocalPort], di            ; Set localport to the identifier number, so we can receive reply's

;        shl     edi, 16

;        mov     di , [esi + ICMP_Packet.SequenceNumber]

;        add     esi, ICMP_Packet.Data

;        mov     ebx, [eax + SOCKET.LocalIP]

;        mov     eax, [eax + SOCKET.RemoteIP]

;        call    ICMP_create_packet

	mov	[esp+32], eax

	ret

;-----------------------------------------------------------------

;

; SOCKET_get_options

;

;

;  IN:  socket number in ecx

;       edx points to the options:

;               dd      level, optname, optval, optlen

;  OUT: -1 on error

;

; At moment, uses only pseudo-optname -2 for get last_ack_number for TCP.

; TODO: find best way to notify that send()'ed data were acknowledged

; Also pseudo-optname -3 is valid and returns socket state, one of TCB_*.

;

;-----------------------------------------------------------------

align 4

socket_get_opt:

	cmp	dword [edx], IP_PROTO_TCP

	jnz	.unknown

	cmp	dword [edx+4], -2

	jz	@f

	cmp	dword [edx+4], -3

	jnz	.unknown

@@:

	mov	eax, [edx+12]

	test	eax, eax

	jz	.fail

	cmp	dword [eax], 4

	mov	dword [eax], 4

	jb	.fail

	stdcall net_socket_num_to_addr, ecx

	test	eax, eax

	jz	.fail

	; todo: check that eax is really TCP socket

	mov	ecx, [eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.last_ack_number]

	cmp	dword [edx+4], -2

	jz	@f

	mov	ecx, [eax + SOCKET_head.end + IPv4_SOCKET.end + TCP_SOCKET.state]

@@:

	mov	eax, [edx+8]

	test	eax, eax

	jz	@f

	mov	[eax], ecx

@@:

	mov	dword [esp+32], 0

	ret

.fail:

.unknown:

	mov	dword [esp+32], -1

	ret

;-----------------------------------------------------------------

;

; SOCKET_find_free_port (local port)

;

; works with INET byte order

;

;  IN:  type in ecx (TCP/UDP)

;  OUT: bx = 0 on error, portnumber otherwise

;

;-----------------------------------------------------------------

align 4

socket_find_port:

	DEBUGF	1,"Socket_find_free_port\n"

	cmp	ecx, IP_PROTO_UDP

	je	.udp

	cmp	ecx, IP_PROTO_TCP

	je	.tcp

  .udp:

	mov	bx, [last_UDP_port]

	je	.continue

  .tcp:

	mov	bx, [last_TCP_port]

  .continue:

	inc	bx

  .check_only:

	mov	esi, net_sockets

  .next_socket:

	mov	esi, [esi + SOCKET_head.NextPtr]

	or	esi, esi

	jz	.port_ok

	cmp	[esi + SOCKET_head.Type], ecx

	jne	.next_socket

	rol	bx, 8

	cmp	[esi + SOCKET_head.end + IPv4_SOCKET.end + UDP_SOCKET.LocalPort], bx

	rol	bx, 8				; this doesnt change the zero flag, does it ?

	jne	.next_socket

	cmp	bx, MAX_EPHEMERAL_PORT

	jle	.continue

	; todo: WRAP!

;        mov     [last_UDP_port], MIN_EPHEMERAL_PORT

  .exit:

	xor	ebx, ebx

  .port_ok:

	rol	bx, 8

	ret

;-----------------------------------------------------------------

;

; SOCKET_check_port (local port)

;

; works with INET byte order

;

;  IN:  type in ecx (TCP/UDP)

;       port to check in bx

;  OUT: bx = 0 on error, unchanged otherwise

;

;-----------------------------------------------------------------

align 4

socket_check_port:

	mov	esi, net_sockets

  .next_socket:

	mov	esi, [esi + SOCKET_head.NextPtr]

	or	esi, esi

	jz	.port_ok

	cmp	[esi + SOCKET_head.Type], ecx

	jne	.next_socket

	cmp	[esi + SOCKET_head.end + IPv4_SOCKET.end + UDP_SOCKET.LocalPort], bx

	jne	.next_socket

	xor	ebx, ebx

  .port_ok:

	ret

;-----------------------------------------------------------------

;

; SOCKET_internal_receiver

;

; Updates a socket with received data

;

; Note: the mutex must already be set !

;

;  IN:  eax = socket ptr

;       ecx = size

;       esi = pointer to buffer

;       edi = offset

;

;  OUT: xxx

;

;-----------------------------------------------------------------

align 4

socket_internal_receiver:

	DEBUGF 1,"Internal socket receiver: buffer %x, offset: %x size=%u socket: %x\n", esi, edi, ecx, eax

	push	edi	; offset

	push	ecx	; size

	push	esi	; data_ptr

	mov	esi, esp

	add_to_queue (eax + SOCKET_QUEUE_LOCATION), SOCKET_QUEUE_SIZE, socket_queue_entry.size, notify_network_event.full

	DEBUGF	1,"Queued packet successfully\n"

	add	esp, socket_queue_entry.size

	mov	[eax + SOCKET_head.lock], 0

notify_network_event:

	; flag an event to the application

	mov	edx, [eax + SOCKET_head.PID]				; get socket owner PID

	mov	ecx, 1

	mov	esi, TASK_DATA + TASKDATA.pid

       .next_pid:

	cmp	[esi], edx

	je	.found_pid

	inc	ecx

	add	esi, 0x20

	cmp	ecx, [TASK_COUNT]

	jbe	.next_pid

	ret

       .found_pid:

	shl	ecx, 8

	or	[ecx + SLOT_BASE + APPDATA.event_mask], EVENT_NETWORK	; stack event

	mov	[check_idle_semaphore], 200

	ret

  .full:

	DEBUGF 1,"Socket %x is full!\n",eax

	mov	[eax + SOCKET_head.lock], 0

	call	kernel_free

	add	esp, 8

	ret

; 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

	init_queue (eax + SOCKET_QUEUE_LOCATION)

	; add socket to the list by changing pointers

	mov	ebx, net_sockets

	push	[ebx + SOCKET_head.NextPtr]

	mov	[ebx + SOCKET_head.NextPtr], eax

	mov	[eax + SOCKET_head.PrevPtr], ebx

	pop	ebx

	mov	[eax + SOCKET_head.NextPtr], ebx

	or	ebx, ebx

	jz	@f

	mov	[ebx + SOCKET_head.PrevPtr], eax

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

	mov	ebx, [TASK_BASE]

	mov	ebx, [ebx + TASKDATA.pid]

	mov	[eax + SOCKET_head.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_head.NextPtr]

	or	ebx, ebx

	jz	.last_socket_number

	cmp	[ebx + SOCKET_head.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_head.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_head.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_head.NextPtr]