WebSVN – Kolibri OS – Diff – /kernel/branches/net/network/tcp_input.inc

 ;;          GNU GENERAL PUBLIC LICENSE                             ;;
 ;;             Version 2, June 1991                                ;;
 ;;                                                                 ;;
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
-$Revision: 2308 $
+$Revision: 2309 $
 ;-----------------------------------------------------------------
+;
 ;-----------------------------------------------------------------
 align 4
 TCP_input:
-       DEBUGF  1,"TCP_input size=%u ", ecx
+        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_header.DataOffset]
-        and     eax, 0xf0
-        shr     al, 2
-        DEBUGF  1,"headersize=%u\n", eax
+        and     [edx + TCP_header.DataOffset], 0xf0                     ; Calculate TCP segment header size (throwing away unused reserved bits in TCP header)
         shr     [edx + TCP_header.DataOffset], 2
-        cmp     eax, TCP_header.DataOffset
+        cmp     [edx + TCP_header.DataOffset], sizeof.TCP_header        ; Now see if it's at least the size of a standard TCP header
-        jb      .drop_not_locked
+        jb      .drop_not_locked                                        ; If not, drop the packet
 ;-------------------------------
 ; Now, re-calculate the checksum
-        push    eax ecx edx
+        push    ecx edx
         pushw   [edx + TCP_header.Checksum]
         mov     [edx + TCP_header.Checksum], 0
         mov     esi, edx
         TCP_checksum (edi), (edi+4)
         pop     cx              ; previous checksum
         cmp     cx, dx
-        pop     edx ecx esi
+        pop     edx ecx
         jnz     .drop_not_locked
-        DEBUGF  1,"Checksum is correct\n"
+        DEBUGF  1,"Checksum ok\n"
-        sub     ecx, esi        ; substract TCP header size from total segment size
+        sub     ecx, [edx + TCP_header.DataOffset]                      ; substract TCP header size from total segment size
-        jb      .drop_not_locked
+        jb      .drop_not_locked                                        ; If total segment size is less then the advertised header size, drop packet
         DEBUGF  1,"we got %u bytes of data\n", ecx
 ; 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)
+; (IP Packet TCP Source Port = remote Port) OR (remote Port = 0)
+        mov     ebx, net_sockets
-        mov     ebx, net_sockets
+        mov     si, [edx + TCP_header.DestinationPort]
   .socket_loop:
         mov     ebx, [ebx + SOCKET.NextPtr]
         jne     .socket_loop
         cmp     [ebx + SOCKET.Protocol], IP_PROTO_TCP
-        jne     .socket_loop
+        jne     .socket_loop
         mov     ax, [edx + TCP_header.DestinationPort]
-        cmp     [ebx + TCP_SOCKET.LocalPort], ax
+        cmp     [ebx + TCP_SOCKET.LocalPort], si
         jne     .socket_loop
         mov     ax, [ebx + TCP_SOCKET.RemotePort]
         cmp     [edx + TCP_header.SourcePort] , ax
         je      .found_socket
         test    ax, ax
         jnz     .socket_loop
-  .found_socket:
+  .found_socket:                                        ; ebx now contains the socketpointer
         DEBUGF  1,"Socket ptr: %x\n", ebx
 ; ebx now contains the pointer to the socket
 ;----------------------------
         add     ebx, SOCKET.lock
         DEBUGF  1,"lock: %x\n", [ebx]
         call    wait_mutex
         sub     ebx, SOCKET.lock
         DEBUGF  1,"Socket locked\n"
         mov     [ebx + TCP_SOCKET.timer_keepalive], TCP_time_keep_interval
 ;--------------------
+; Process TCP options
-; Process TCP options
         mov     eax, [edx + TCP_header.DataOffset]
-        cmp     esi, TCP_header.DataOffset              ; Does header contain any options?
+        cmp     eax, TCP_header.DataOffset              ; Does header contain any options?
         je      .no_options
         DEBUGF  1,"Segment has options\n"
         cmp     [ebx + TCP_SOCKET.t_state], TCPS_LISTEN ; no options when in listen state
         jz      .not_uni_xfer                           ; also no header prediction
         DEBUGF  1,"header prediction: we are receiver\nreceiving %u bytes of data\n", ecx
         add     [ebx + TCP_SOCKET.RCV_NXT], ecx         ; Update sequence number with number of bytes we have copied
-        movzx   esi, [edx + TCP_header.DataOffset]
         and     esi, 0xf0
-        shr     esi, 2
+        movzx   esi, [edx + TCP_header.DataOffset]
         add     esi, edx
         lea     eax, [ebx + STREAM_SOCKET.rcv]
         cmp     [ebx + TCP_SOCKET.SND_UNA], eax
         ja      .drop_with_reset
         cmp     eax, [ebx + TCP_SOCKET.SND_MAX]
         ja      .drop_with_reset
+;;; TODO: update stats
         ;;; update stats
         mov     eax, ebx
         call    SOCKET_is_connected
         mov     [ebx + TCP_SOCKET.t_state], TCPS_ESTABLISHED
         test    [ebx + TCP_SOCKET.t_flags], TF_RCVD_SCALE
         jz      @f
         test    [ebx + TCP_SOCKET.t_flags], TF_REQ_SCALE
         jz      @f
+        push    word [ebx + TCP_SOCKET.requested_s_scale]       ; Set send and receive scale factors to the received values
-        ;;; 810-811
         pop     word [ebx + TCP_SOCKET.SND_SCALE]
        @@:
-        ;;; 813 ?
+;;; TODO: copy the data (if any) into the socket
         mov     eax, [edx + TCP_header.SequenceNumber]
         cmp     eax, [ebx + TCP_SOCKET.SND_WND]
         jne     .reset_dupacks
         DEBUGF  1,"Processing a duplicate ACK..\n"
-        cmp     [ebx + TCP_SOCKET.timer_retransmission], 10000 ;;;;
+        cmp     [ebx + TCP_SOCKET.timer_retransmission], 10000 ;;;;  FIXME
         ja      @f
         mov     eax, [ebx + TCP_SOCKET.SND_WL2]
         cmp     eax, [edx + TCP_header.AckNumber]
         jne     .no_window_update
-        movzx   eax, [edx + TCP_header.Window]
+        mov     eax, dword [edx + TCP_header.Window]
         cmp     eax, [ebx + TCP_SOCKET.SND_WND]
         DEBUGF  1,"Processing data in segment\n"
 ;; TODO: check if data is in sequence !
-        movzx   esi, [edx + TCP_header.DataOffset]
         and     esi, 0xf0
-        shr     esi, 2
+        movzx   esi, [edx + TCP_header.DataOffset]
         add     esi, edx

Subversion Repositories Kolibri OS

(root)/kernel/branches/net/network/tcp_input.inc @ 3407 – Rev 2308 → 2309