Subversion Repositories Kolibri OS

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

;;                                                                 ;;

;; Copyright (C) KolibriOS team 2004-2010. 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: 1514 $

virtual at 0

	SOCKET:

	.NextPtr		dd ? ; pointer to next socket in list

	.PrevPtr		dd ? ; pointer to previous socket in list

	.Number 		dd ? ; socket number

	.lock			dd ? ; lock mutex

	.PID			dd ? ; application process id

	.Domain 		dd ? ; INET/UNIX/..

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

	.Protocol		dd ? ; ICMP/IPv4/ARP/

	.errorcode		dd ?

	.options		dd ?

	.SO_SND.SB_CC		dd ?  ;;;;; socket options: number of bytes in socket

	.SO_RCV.SB_CC		dd ?

	.state			dd ?  ;;;;;;;;;

	.end:

end virtual

virtual at SOCKET.end

	IP_SOCKET:

	.LocalIP		dd ?

				rd 3 ; for IPv6 addresses

	.RemoteIP		dd ?

				rd 3 ; for IPv6 addresses

	.end:

end virtual

virtual at SOCKET.end

	SOCKET_virtual:

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

	.end:

end virtual

virtual at IP_SOCKET.end

	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

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

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

	.t_state		dd ? ; TCB state

	.t_timer		dd ? ; TCB timer (seconds)

	.t_rxtshift		dd ?

	.t_rxtcur		dd ?

	.t_dupacks		dd ?

	.t_maxseg		dd ?

	.t_force		dd ?

	.t_flags		dd ?

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

; RFC783 page 21

; send sequence

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

	.SND_NXT		dd ? ; next send sequence number to use

	.SND_UP 		dd ?

	.SND_WL1		dd ? ; window minus one

	.SND_WL2		dd ? ;

	.ISS			dd ? ; initial send sequence number

	.SND_WND		dd ? ; send window

; receive sequence

	.RCV_WND		dw ? ; receive window

	.RCV_NXT		dd ? ; next receive sequence number to use

	.RCV_UP 		dd ?

	.IRS			dd ? ; initial receive sequence number

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

; Additional variables

; receive variables

	.RCV_ADV		dd ?

; retransmit variables

	.SND_MAX		dd ?

; congestion control

	.SND_CWND		dd ?

	.SND_SSTHRESH		dd ?

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

; Transmit timing stuff

	.t_idle 		dd ?

	.t_rtt			dd ?

	.t_rtseq		dd ?

	.t_srtt 		dd ?

	.t_rttvar		dd ?

	.t_rttmin		dd ?

	.max_sndwnd		dd ?

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

; Out-of-band data

	.t_oobflags		dd ?

	.t_iobc 		dd ?

	.t_softerror		dd ?

;---------

; RFC 1323

	.SND_SCALE		db ? ; Scale factor

	.RCV_SCALE		db ?

	.request_r_scale	db ?

	.requested_s_scale	dd ?

	.ts_recent		dd ?

	.ts_recent_age		dd ?

	.last_ack_sent		dd ?

	.end:

end virtual

virtual at IP_SOCKET.end

	UDP_SOCKET:

	.LocalPort		dw ? ; In INET byte order

	.RemotePort		dw ? ; In INET byte order

	.firstpacket		db ?

	.end:

end virtual

virtual at IP_SOCKET.end

	ICMP_SOCKET:

	.Identifier		dw ? ;

	.end:

end virtual

struct	socket_queue_entry

;        .owner          dd ?

	.data_ptr	dd ?

	.buf_ptr	dd ?

	.data_size	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

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

SOCKET_QUEUE_LOCATION	equ SOCKETBUFFSIZE - SOCKET_QUEUE_SIZE*socket_queue_entry.size - queue.data

uglobal

	net_sockets	rd 4

	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:

	xor	eax, eax

	mov	edi, net_sockets

	mov	ecx, 4

	rep	stosd

	mov	[last_UDP_port], MIN_EPHEMERAL_PORT

	mov	[last_TCP_port], MIN_EPHEMERAL_PORT

	ret

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

;

; Socket API (function 74)

;

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

align 4

sys_socket:

	cmp	ebx, 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_receive	; 7

	dd	SOCKET_get_opt	; 8

;        dd      SOCKET_set_opt  ; 9

s_error:

	DEBUGF	1,"socket error\n"

	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 protocol: %x\n", ecx, edx, esi

	call	SOCKET_alloc

	jz	s_error

	mov	[eax + SOCKET.Domain], ecx

	mov	[eax + SOCKET.Type], edx

	mov	[eax + SOCKET.Protocol], esi

	mov	[esp+32], edi

	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\n", ecx, edx, esi

	call	SOCKET_num_to_ptr

	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:

	DEBUGF	1,"af_inet4\n"

	cmp	esi, 6

	jl	s_error

	mov	ecx, [eax + SOCKET.Type]

	mov	bx, word [edx + 2]

	test	bx, bx

	jz	.find_free

	call	SOCKET_check_port

;        test    bx, bx

	jz	s_error

	jmp	.got_port

    .find_free:

	call	SOCKET_find_port

;        test    bx, bx

	jz	s_error

    .got_port:

	DEBUGF	1,"using local port: %u", bx

	mov	word [eax + UDP_SOCKET.LocalPort], bx

	mov	ebx, dword [edx + 4]

	mov	dword [eax + IP_SOCKET.LocalIP], ebx

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

	[eax + IP_SOCKET.LocalIP + 0]:1,[eax + IP_SOCKET.LocalIP + 1]:1,\

	[eax + IP_SOCKET.LocalIP + 2]:1,[eax + IP_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\n", ecx, edx, esi

	call	SOCKET_num_to_ptr

	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.Type], IP_PROTO_UDP

	je	.udp

	cmp	[eax + SOCKET.Type], IP_PROTO_TCP

	je	.tcp

	jmp	s_error

  .udp:

	mov	bx , word [edx + 2]

	mov	word [eax + UDP_SOCKET.RemotePort], bx

	mov	[eax + UDP_SOCKET.firstpacket], 0

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

	mov	ebx, dword [edx + 4]

	mov	dword [eax + IP_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:

	; set sequence number

	mov	ebx, [TCP_sequence_num]

	add	[TCP_sequence_num], 6400

	mov	[eax + TCP_SOCKET.ISS], ebx

	lea	ebx, [eax + SOCKET.lock]

	call	wait_mutex

	; fill in remote port and IP

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

	mov	bx , word [edx + 2]

	mov	[eax + TCP_SOCKET.RemotePort], bx

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

	mov	ebx, dword [edx + 4]

	mov	[eax + IP_SOCKET.RemoteIP], ebx

	; check if local port and IP is ok

	cmp	[eax + IP_SOCKET.LocalIP], 0

	jne	@f

	push	[IP_LIST]	    ;;;;; device zero = default

	pop	[eax + IP_SOCKET.LocalIP]

       @@:

	cmp	[eax + TCP_SOCKET.LocalPort], 0

	jne	@f

	call	SOCKET_find_port

       @@:

;        mov     [eax + TCP_SOCKET.t_state], TCB_SYN_SENT

	call	TCP_output

	mov	[eax + SOCKET.lock], 0

	mov	dword [esp+32], 0	; success!

	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

	call	SOCKET_num_to_ptr

	jz	s_error

	cmp	word [eax + SOCKET.Domain], AF_INET4

	jne	s_error

	cmp	[eax + SOCKET.Type], IP_PROTO_TCP

	jne	s_error

	; TODO: check local port number

	cmp	edx, MAX_backlog

	jle	.ok

	mov	edx, MAX_backlog

  .ok:

	mov	[eax + TCP_SOCKET.backlog], dx

	mov	[eax + TCP_SOCKET.t_state], TCB_LISTEN

	 or	[eax + SOCKET.options], SO_ACCEPTCON

	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

	call	SOCKET_num_to_ptr

	jz	s_error

	cmp	word [eax + SOCKET.Domain], AF_INET4

	je	.af_inet4

	jmp	s_error

  .af_inet4:

	cmp	[eax + SOCKET.Type], IP_PROTO_TCP

	je	.tcp

	jmp	s_error

  .tcp:

	lea	ebx, [eax + SOCKET.lock]

	call	wait_mutex

	movzx	ebx, [eax + TCP_SOCKET.backlog_cur]

	test	ebx, ebx

	jz	.unlock_err

	dec	[eax + TCP_SOCKET.backlog_cur]

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

	mov	[eax + SOCKET.lock], 0

	mov	dword [esp+32], 0

	call	TCP_output	;;;;;

	ret

  .unlock_err:

	mov	[eax + SOCKET.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

	call	SOCKET_num_to_ptr

	jz	s_error

	cmp	[eax + SOCKET.Domain], AF_INET4

	jne	s_error

	cmp	[eax + SOCKET.Type], IP_PROTO_UDP

	je	.free

	cmp	[eax + SOCKET.Type], IP_PROTO_ICMP

	je	.free

	cmp	[eax + SOCKET.Type], IP_PROTO_TCP

	je	.tcp

	jmp	s_error

  .tcp:

	test	[eax + TCP_SOCKET.t_state], TCB_SYN_RECEIVED  ;;;;;;

	jz	.free

	call	TCP_output

	mov	dword [esp+32], 0

	ret

;       state must be LISTEN, SYN_SENT, CLOSED or maybe even invalid

;       so, we may destroy the socket

  .free:

	call	SOCKET_free

	mov	dword [esp+32], 0

	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_receive:

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

	call	SOCKET_num_to_ptr

	jz	s_error

	mov	ebx, esi

	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.buf_ptr]	       ; save the buffer addr so we can clear it later

	mov	esi, [esi + socket_queue_entry.data_ptr]

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

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

; copy the data

	shr	ecx, 1

	jnc	.nb

	movsb

.nb:	shr	ecx, 1

	jnc	.nw

	movsw

.nw:	test	ecx, ecx

	jz	.nd

	rep	movsd

.nd:

; remove the packet     ;;; TODO: only if it is empty!!

;;;;        call    TCP_output  ; only if it is tcp

	call	kernel_free

	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\n", ecx, edx, esi, edi

	call	SOCKET_num_to_ptr

	jz	s_error

	cmp	word [eax + SOCKET.Domain], AF_INET4

	je	.af_inet4

	jmp	s_error

  .af_inet4:

	DEBUGF	1,"af_inet4\n"

	cmp	[eax + SOCKET.Type], IP_PROTO_TCP

	je	.tcp

	cmp	[eax + SOCKET.Type], IP_PROTO_UDP

	je	.udp

	jmp	s_error

  .udp:

	DEBUGF	1,"type: UDP\n"

; check if local port is valid

	cmp	[eax + UDP_SOCKET.LocalPort], 0

	jne	@f

	call	SOCKET_find_port

	jz	s_error

; Now, send the packet

     @@:

	mov	ecx, esi

	mov	esi, edx

	call	UDP_output

	mov	dword [esp+32], 0

	ret

  .tcp:

	DEBUGF	1,"type: TCP\n"

; check if local port is valid

	cmp	[eax + TCP_SOCKET.LocalPort], 0

	jne	@f

	call	SOCKET_find_port

	jz	s_error

     @@:

;;;; TODO: queue the data

	call	TCP_output

	mov	[esp+32], eax

	ret

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

;

; SOCKET_get_options

;

;  IN:  ecx = socket number

;       edx = pointer 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:

	DEBUGF	1,"socket_get_opt\n"

	call	SOCKET_num_to_ptr

	jz	s_error

	cmp	dword [edx], IP_PROTO_TCP

	jnz	s_error

	cmp	dword [edx+4], -2

	jz	@f

	cmp	dword [edx+4], -3

	jnz	s_error

@@:

;        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 + TCP_SOCKET.last_ack_number]

;        cmp     dword [edx+4], -2

;        jz      @f

;        mov     ecx, [eax + TCP_SOCKET.state]

@@:

	mov	eax, [edx+8]

	test	eax, eax

	jz	@f

	mov	[eax], ecx

@@:

	mov	dword [esp+32], 0

	ret

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

;

; SOCKET_find_port

;

; Fills in the local port number for TCP and UDP sockets

; This procedure always works because the number of sockets is

; limited to a smaller number then the number of possible ports

;

;  IN:  eax = socket pointer

;  OUT: /

;

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

align 4

SOCKET_find_port:

	DEBUGF	1,"socket_find_free_port\n"

	push	ebx esi ecx

	cmp	[eax + SOCKET.Type], IP_PROTO_UDP

	je	.udp

	cmp	[eax + SOCKET.Type], IP_PROTO_TCP

	je	.tcp

	jmp	.error

  .done:

	mov	[eax + UDP_SOCKET.LocalPort], bx

  .error:

	pop	ecx esi ebx

	ret

  .udp:

	mov	bx, [last_UDP_port]

	call	.findit

	mov	[last_UDP_port], bx

	jmp	.done

  .tcp:

	mov	bx, [last_TCP_port]

	call	.findit

	mov	[last_TCP_port], bx

	jmp	.done

  .restart:

	mov	bx, MIN_EPHEMERAL_PORT

  .findit:

	inc	bx

	cmp	bx, MAX_EPHEMERAL_PORT

	jz	.restart

	call	SOCKET_check_port

	jz	.findit

	ret

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

;

; SOCKET_check_port

;

; Checks if a local port number is unused

; If the proposed port number is unused, it is filled in in the socket structure

;

;  IN:  eax = socket ptr (to find out if its a TCP/UDP socket)

;        bx = proposed socket number

;

;  OUT:  ZF = cleared on error

;

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

align 4

SOCKET_check_port:

	DEBUGF	1,"socket_check_port\n"

	mov	ecx, [eax + SOCKET.Type]

	mov	esi, net_sockets

  .next_socket:

	mov	esi, [esi + SOCKET.NextPtr]

	or	esi, esi

	jz	.port_ok

	cmp	[esi + SOCKET.Type], ecx

	jne	.next_socket

	cmp	[esi + UDP_SOCKET.LocalPort], bx

	jne	.next_socket

	DEBUGF	1,"local port %u already in use\n", bx

	ret

  .port_ok:

	mov	[eax + UDP_SOCKET.LocalPort], bx

	or	bx, bx					; set the zero-flag

	ret

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

;

; SOCKET_input

;

; Updates a socket with received data

;

; Note: the mutex should already be set !

;

;  IN:  eax = socket ptr

;       ebx = pointer to device struct

;       ecx = data size

;       esi = ptr to data

;       [esp] = ptr to buf

;       [esp + 4] = buf size

;

;  OUT: /

;

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

align 4

SOCKET_input:

	DEBUGF	1,"socket_input: socket=%x, data=%x size=%u\n", eax, esi, ecx

	mov	dword[esp+4], ecx

	push	esi

	mov	esi, esp

	add_to_queue (eax + SOCKET_QUEUE_LOCATION),\

		     SOCKET_QUEUE_SIZE,\

		     socket_queue_entry.size,\

		     SOCKET_input.full

	DEBUGF	1,"Queued packet successfully\n"

	add	esp, socket_queue_entry.size

	mov	[eax + SOCKET.lock], 0

	jmp	SOCKET_notify_owner

  .full:

	DEBUGF	2,"Socket %x is full!\n", eax

	mov	[eax + SOCKET.lock], 0

	call	kernel_free

	add	esp, 8

	ret

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

;

; SOCKET_notify_owner

;

; notify's the owner of a socket that something happened

;

;  IN:  eax = socket ptr

;  OUT: /

;

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

align 4

SOCKET_notify_owner:

	DEBUGF	1,"socket_notify_owner\n"

	call	SOCKET_check

	jz	.error

	push	ecx eax esi

; socket exists, now try to flag an event to the application

	mov	eax, [eax + SOCKET.PID]

	mov	ecx, 1

	mov	esi, TASK_DATA + TASKDATA.pid

       .next_pid:

	cmp	[esi], eax

	je	.found_pid

	inc	ecx

	add	esi, 0x20

	cmp	ecx, [TASK_COUNT]

	jbe	.next_pid

; PID not found, TODO: close socket!

	jmp	.error2

       .found_pid:

	shl	ecx, 8

	or	[ecx + SLOT_BASE + APPDATA.event_mask], EVENT_NETWORK

	mov	[check_idle_semaphore], 200

	DEBUGF	1,"owner notified\n"

  .error2:

	pop	esi eax ecx

  .error:

	ret

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

;

; SOCKET_alloc

;

; 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).

;

; IN:  /

; OUT: eax = 0 on error, socket ptr otherwise

;      edi = socket number

;       ZF = cleared on error

;

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

align 4

SOCKET_alloc:

	push	ecx ebx

	stdcall kernel_alloc, SOCKETBUFFSIZE

	DEBUGF	1, "socket_alloc: %x ", eax

	or	eax, eax

	jz	.exit

; zero-initialize allocated memory

	push	eax edi

	mov	edi, eax

	mov	ecx, SOCKETBUFFSIZE / 4

	xor	eax, eax

	rep	stosd

	pop	edi eax

	init_queue (eax + SOCKET_QUEUE_LOCATION)

; find first free socket number and use it

	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

	cmp	[ebx + SOCKET.Number], ecx

	jne	.next_socket

	mov	ebx, net_sockets

	jmp	.next_socket_number

  .last_socket:

	mov	[eax + SOCKET.Number], ecx

	DEBUGF	1, "(number: %u)\n", ecx

; Fill in PID

	mov	ebx, [TASK_BASE]

	mov	ebx, [ebx + TASKDATA.pid]

	mov	[eax + SOCKET.PID], ebx

; add socket to the list by changing pointers

	mov	ebx, [net_sockets + SOCKET.NextPtr]

	mov	[eax + SOCKET.PrevPtr], net_sockets

	mov	[eax + SOCKET.NextPtr], ebx

	or	ebx, ebx

	jz	@f

	add	ebx, SOCKET.lock	; lock the next socket

	call	wait_mutex

	sub	ebx, SOCKET.lock

	mov	[ebx + SOCKET.PrevPtr], eax

	mov	[ebx + SOCKET.lock], 0