Subversion Repositories Kolibri OS

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;;                                                                 ;;

;; Copyright (C) KolibriOS team 2004-2010. All rights reserved.    ;;

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

;;                                                                 ;;

;;  UDP.INC                                                        ;;

;;                                                                 ;;

;;  Part of the tcp/ip network stack for KolibriOS                 ;;

;;                                                                 ;;

;;    Written by hidnplayr@kolibrios.org                           ;;

;;                                                                 ;;

;;          GNU GENERAL PUBLIC LICENSE                             ;;

;;             Version 2, June 1991                                ;;

;;                                                                 ;;

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

$Revision: 2311 $

struct  UDP_header

        SourcePort              dw  ?

        DestinationPort         dw  ?

        Length                  dw  ?  ; Length of (UDP Header + Data)

        Checksum                dw  ?

ends

align 4

uglobal

        UDP_PACKETS_TX          rd  MAX_IP

        UDP_PACKETS_RX          rd  MAX_IP

endg

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

;

; UDP_init

;

;  This function resets all UDP variables

;

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

macro   UDP_init {

        xor     eax, eax

        mov     edi, UDP_PACKETS_TX

        mov     ecx, 2*MAX_IP

        rep     stosd

}

macro   UDP_checksum    IP1, IP2  { ; esi = ptr to udp packet, ecx = packet size, destroys: ecx, edx

; Pseudoheader

        mov     edx, IP_PROTO_UDP

        add     dl, [IP1+1]

        adc     dh, [IP1+0]

        adc     dl, [IP1+3]

        adc     dh, [IP1+2]

        adc     dl, [IP2+1]

        adc     dh, [IP2+0]

        adc     dl, [IP2+3]

        adc     dh, [IP2+2]

        adc     dl, cl ; byte[esi+UDP_header.Length+1]

        adc     dh, ch ; byte[esi+UDP_header.Length+0]

; Done with pseudoheader, now do real header

        adc     dl, byte[esi+UDP_header.SourcePort+1]

        adc     dh, byte[esi+UDP_header.SourcePort+0]

        adc     dl, byte[esi+UDP_header.DestinationPort+1]

        adc     dh, byte[esi+UDP_header.DestinationPort+0]

        adc     dl, byte[esi+UDP_header.Length+1]

        adc     dh, byte[esi+UDP_header.Length+0]

        adc     edx, 0

; Done with header, now do data

        push    esi

        movzx   ecx, [esi+UDP_header.Length]

        rol     cx , 8

        sub     cx , sizeof.UDP_header

        add     esi, sizeof.UDP_header

        call    checksum_1

        call    checksum_2

        pop     esi

        add     [esi+UDP_header.Checksum], dx   ; this final instruction will set or clear ZF :)

}

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

;

; UDP_input:

;

;  Called by IPv4_input,

;  this procedure will inject the udp data diagrams in the application sockets.

;

;  IN:   [esp]  = Pointer to buffer

;       [esp+4] = size of buffer

;       ebx = ptr to device struct

;       ecx = UDP Packet size

;       esi = ptr to UDP header

;       edi = ptr to ipv4 source and dest address

;

;  OUT: /

;

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

align 4

UDP_input:

        DEBUGF  1,"UDP_input, size:%u\n", ecx

; First validate, checksum

        neg     [esi + UDP_header.Checksum]     ; substract checksum from 0

        jz      .no_checksum                    ; if checksum is zero, it is considered valid and we continue processing

                                                ; otherwise, we will re-calculate the checksum and add it to this value, thus creating 0 when it is correct

        push    esi

        UDP_checksum (edi), (edi+4)

        pop     edx

        jnz     .checksum_mismatch

  .no_checksum:

        DEBUGF  1,"UDP Checksum is correct\n"

        ; Convert port numbers to intel format

        rol     [edx + UDP_header.DestinationPort], 8

        rol     [edx + UDP_header.SourcePort], 8

        rol     [edx + UDP_header.Length], 8

        ; Look for a socket where

        ; IP Packet UDP Destination Port = local Port

        ; IP Packet SA = Remote IP

        mov     si, [edx + UDP_header.DestinationPort]

        mov     cx, [edx + UDP_header.SourcePort]

        mov     edi, [edi + 4]                          ; ipv4 source address

        mov     eax, net_sockets

  .next_socket:

        mov     eax, [eax + SOCKET.NextPtr]

        or      eax, eax

        jz      .dump

        cmp     [eax + SOCKET.Domain], AF_INET4

        jne     .next_socket

        cmp     [eax + SOCKET.Protocol], IP_PROTO_UDP

        jne     .next_socket

        cmp     [eax + UDP_SOCKET.LocalPort], si

        jne     .next_socket

        DEBUGF  1,"using socket: %x\n", eax

        ;;; TODO: when packet is processed, check more sockets!

        cmp     [eax + IP_SOCKET.RemoteIP], 0xffffffff

        je      @f

        cmp     [eax + IP_SOCKET.RemoteIP], edi

        jne     .next_socket

       @@:

        cmp     [eax + UDP_SOCKET.firstpacket], 0

        je      .updateport

        cmp     [eax + UDP_SOCKET.RemotePort], cx

        jne     .dump

        push    ebx

        lea     ebx, [eax + SOCKET.lock]

        call    wait_mutex

        pop     ebx

  .updatesock:

        inc     [UDP_PACKETS_RX]

        DEBUGF  1,"Found valid UDP packet for socket %x\n", eax

        lea     esi, [edx + sizeof.UDP_header]

        movzx   ecx, [edx + UDP_header.Length]

        sub     ecx, sizeof.UDP_header

        jmp     SOCKET_input

  .updateport:

        push    ebx

        lea     ebx, [eax + SOCKET.lock]

        call    wait_mutex

        pop     ebx

        DEBUGF  1,"Changing remote port to: %u\n", cx

        mov     [eax + UDP_SOCKET.RemotePort], cx

        inc     [eax + UDP_SOCKET.firstpacket]

        jmp     .updatesock

  .checksum_mismatch:

        DEBUGF  2,"UDP_Handler - checksum mismatch\n"

  .dump:

        call    kernel_free

        add     esp, 4 ; pop (balance stack)

        DEBUGF  2,"UDP_Handler - dumping\n"

        ret

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

;

; UDP_output

;

; IN: eax = socket pointer

;     ecx = number of bytes to send

;     esi = pointer to data

;

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

align 4

UDP_output:

        DEBUGF  1,"UDP_output: socket:%x, bytes: %u, data ptr: %x\n", eax, ecx, esi

        mov     dx, [eax + UDP_SOCKET.RemotePort]

        DEBUGF  1,"remote port: %u\n", dx

        rol     dx, 8

        rol     edx, 16

        mov     dx, [eax + UDP_SOCKET.LocalPort]

        DEBUGF  1,"local port: %u\n", dx

        rol     dx, 8

        mov     ebx, [eax + IP_SOCKET.LocalIP]

        mov     eax, [eax + IP_SOCKET.RemoteIP]

        mov     di, IP_PROTO_UDP shl 8 + 128

        sub     esp, 8                                          ; Data ptr and data size will be placed here

        add     ecx, sizeof.UDP_header

;;; TODO: fragment id

        push    edx esi

        call    IPv4_output

        jz      .fail

        mov     [esp + 8], eax                                  ; pointer to buffer start

        mov     [esp + 8 + 4], edx                              ; buffer size

        mov     [edi + UDP_header.Length], cx

        rol     [edi + UDP_header.Length], 8

        pop     esi

        push    edi ecx

        sub     ecx, sizeof.UDP_header

        add     edi, sizeof.UDP_header

        shr     ecx, 2

        rep     movsd

        mov     ecx, [esp]

        and     ecx, 3

        rep     movsb

        pop     ecx edi

        pop     dword [edi + UDP_header.SourcePort]

; Checksum

        mov     esi, edi

        mov     [edi + UDP_header.Checksum], 0

        UDP_checksum (edi-4), (edi-8)                           ; TODO: fix this, IPv4 packet could have options..

        inc     [UDP_PACKETS_TX]

        DEBUGF  1,"Sending UDP Packet to device %x\n", ebx

        call    [ebx + NET_DEVICE.transmit]

        ret

  .fail:

        DEBUGF  1,"UDP_output: failed\n"

        add     esp, 4+4+8

        xor     eax, eax

        ret

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

;

; UDP_API

;

; This function is called by system function 75

;

; IN:  subfunction number in bl

;      device number in bh

;      ecx, edx, .. depends on subfunction

;

; OUT:

;

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

align 4

UDP_API:

        movzx   eax, bh

        shl     eax, 2

        test    bl, bl

        jz      .packets_tx     ; 0

        dec     bl

        jz      .packets_rx     ; 1

.error:

        mov     eax, -1

        ret

.packets_tx:

        mov     eax, [UDP_PACKETS_TX + eax]

        ret

.packets_rx:

        mov     eax, [UDP_PACKETS_RX + eax]

        ret