Chip 1994 February

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Assembly Source File | 1993-06-11 | 19.1 KB | 850 lines

version equ 4 include defs.asm ;SEE ENCLOSED COPYRIGHT MESSAGE NCB_NOWAIT equ 80h ; Command wait flag NCB_RESET equ 32h ; Reset adapter NCB_CANCEL equ 35h ; Cancel command NCB_STATUS equ 33h ; Get NETBIOS intf status NCB_UNLINK equ 70h ; Unlink (RPL) NCB_ADDNAME equ 30h ; Add name NCB_ADDGNAME equ 36h ; Add group name NCB_DELNAME equ 31h ; Delete name NCB_FINDNAME equ 78h ; Find name NCB_CALL equ 10h ; Call NCB_LISTEN equ 11h ; Listen NCB_HANGUP equ 12h ; Hang up NCB_SEND equ 14h ; Send NCB_CHSEND equ 17h ; Chain send NCB_RECEIVE equ 15h ; Receive NCB_RECANY equ 16h ; Receive any NCB_SESSTATUS equ 34h ; Get session status NCB_SDATAGRAM equ 20h ; Send datagram NCB_SBROADCAST equ 22h ; Send broadcast NCB_RDATAGRAM equ 21h ; Receive datagram NCB_RBROADCAST equ 23h ; Receive broadcast NCB_TRACE equ 79h ; Start trace ; ; Network Control Block structure ; ncb struc ncb_command db ? ncb_retcode db ? ncb_lsn db ? ncb_num db ? ncb_buffer dd ? ncb_length dw ? ncb_callname db 16 dup(?) ncb_name db 16 dup(?) ncb_rto db ? ncb_sto db ? ncb_post dd ? ncb_lana_num db ? ncb_cmd_cplt db ? ncb_reserve db 14 dup(?) ncb ends ; ; ARP packet structure ; arp struc arp_hw dw ? ; Hardware address length, bytes arp_prot dw ? ; Protocol type arp_hwalen db ? ; hardware address length, bytes arp_pralen db ? ; Length of protocol address arp_opcode dw ? ; ARP opcode (request/reply) arp_shwaddr db 6 dup(?) ; Sender hardware address field arp_sprotaddr dd ? ; Sender Protocol address field arp_thwaddr db 6 dup(?) ; Target hardware address field arp_tprotaddr dd ? ; Target protocol address field arp ends code segment word public assume cs:code, ds:code ;*************************************************************** prefix db "TCPIP" public int_no int_no db 0,0,0,0 ip_adress dw 2 dup(0) rq_size dw 3 padding dd 0 public driver_class, driver_type, driver_name, driver_function, parameter_list driver_class db 1,0 ;from the packet spec driver_type db 0 ;from the packet spec driver_name db 'netbios',0 ;name of the driver. driver_function db 2 parameter_list label byte db 1 ;major rev of packet driver db 9 ;minor rev of packet driver db 14 ;length of parameter list db EADDR_LEN ;length of MAC-layer address dw 1500 ;MTU, including MAC headers dw MAX_MULTICAST * EADDR_LEN ;buffer size of multicast addrs dw 0 ;(# of back-to-back MTU rcvs) - 1 dw 0 ;(# of successive xmits) - 1 int_num dw 0 ;Interrupt # to hook for post-EOI ;processing, 0 == none, public rcv_modes rcv_modes dw 4 ;number of receive modes in our table. dw 0,0,0,rcv_mode_3 lana_num db 0 local_ncb_num db 0 ; handle returned by add_name public nbsend, nbrcv1, nbrcv2, rcv_buffer1 ; MAP nbsend ncb <> nbrcv1 ncb <> nbrcv2 ncb <> MAX_DG equ 1500 rcv_buffer1 db MAX_DG dup(?) public bad_command_intercept bad_command_intercept: ;called with ah=command, unknown to the skeleton. ;exit with nc if okay, cy, dh=error if not. mov dh,BAD_COMMAND stc ret public as_send_pkt ; The Asynchronous Transmit Packet routine. ; Enter with es:di -> i/o control block, ds:si -> packet, cx = packet length, ; interrupts possibly enabled. ; Exit with nc if ok, or else cy if error, dh set to error number. ; es:di and interrupt enable flag preserved on exit. as_send_pkt: ret public drop_pkt ; Drop a packet from the queue. ; Enter with es:di -> iocb. drop_pkt: assume ds:nothing ret public xmit ; Process a transmit interrupt with the least possible latency to achieve ; back-to-back packet transmissions. ; May only use ax and dx. xmit: assume ds:nothing ret ; ; recv_find() requires a pointer to the Ethernet packet type. Since ; the incoming packet does not contain an Ethernet packet type field, ; memory must be allocated to hold the Ethernet packet type. Space is ; required for both IP and ARP types. ; ip_type label byte db 08 db 00 arp_type label byte db 08 db 06 gw_switch db 00 public send_pkt send_pkt: assume ds: nothing ;enter with ds:si -> packet, cx = packet length. ;exit with nc if ok, or else cy if error, dh set to error number. cmp cx,GIANT ; Is this packet too large? ja send_pkt_toobig push es push bx push ds ;strip off Ethernet header add si,12 mov ax, word ptr ds:[si] add si,2 sub cx,14 ; ; Check packet type. If an ARP packet then construct an ARP reply ; packet. Otherwise, process the incoming IP packet. ; cmp ax,0608h jne noarp call arp_reply jmp send_ok noarp: push cs pop es ; ; Set up NCB for a "SEND DATAGRAM" operation ; mov bx,offset cs:nbsend mov cs:[bx].ncb_buffer.offs,si mov ax,ds mov cs:[bx].ncb_buffer.segm,ds mov cs:[bx].ncb_length,cx push bx lea di,cs:nbsend.ncb_callname ; ; If gateway switch set then contruct NETBIOS name based on the destination ; IP address in the IP packet. Otherwise, construct the NETBIOS name ; based on the destination Ethernet address. ; mov al,gw_switch cmp al,0 je use_hw_addr mov bx, word ptr ds:[si+16] mov dx, word ptr ds:[si+18] jmp conv_addr use_hw_addr: mov bx, word ptr ds:[si-12] mov dx, word ptr ds:[si-10] conv_addr: push cs pop ds call ip_to_nbname pop bx ; ; Pass "Send Datagram" NCB to NETBIOS ; int 5ch ; ; If "Send Datagram" operation is unsuccessful then print return code and ; set carry bit. Otherwise, clear the carry bit. ; cmp al,0 jz send_ok add ax,32 call tty mov al,'S' call tty stc jmp send_done send_ok: clc send_done: pop ds pop bx pop es ret send_pkt_toobig: mov dh,NO_SPACE stc ret ; ; Formulate a dummy ARP reply packet. ds:si points at the incoming ; IP packet. ; arp_reply: ; ; Save the registers. Not sure that we need to but it works and I ; don't want to change it right now. ; push ds push es push si push di push cx ; ; Check to see if the ARP request is to find the hardware address ; of the local host. If so, then don't formulate a reply packet. ; mov cx,4 mov ax,si mov di,ax mov ax,ds mov es,ax add di,arp_sprotaddr add si,arp_tprotaddr repe cmpsb ; Compare source and target ; protocol address jnz arp_reply_2 pop cx pop di pop si pop es pop ds ret arp_reply_2: ; ; Restore registers. ; pop cx pop di pop si push si push di push cx ; ; Restore Ethernet header. ; add cx,14 sub si,14 ; ; Ask application layer for a memory buffer in which to store ; incoming packet. ; push ds push si ;save si in case we reject it. push bx push cx mov ax,cs mov es,ax mov ds,ax mov di, offset arp_type mov dl,cs:driver_class call recv_find ;look up our type. pop cx pop bx pop si pop ds mov ax,es ;is this pointer null? or ax,di je arp_reply_1 ;yes - just free the frame. push cx push es push di ; ; Save si,di for future use. ; mov bx,si mov dx,di ; ; Set up ARP Reply by first copying the ARP Request packet. ; rep movsb ; ; Skip Ethernet header ; add bx,14 add dx,14 ; ; Swap target and source protocol addresses from ARP request to ARP ; reply packet. ; mov si,bx mov di,dx mov cx,4 add si,arp_tprotaddr add di,arp_sprotaddr rep movsb mov si,bx mov di,dx mov cx,4 add si,arp_sprotaddr add di,arp_tprotaddr rep movsb ; ; Swap target and source hardware addresses from ARP request to ARP ; reply packet. ; mov si,bx mov di,dx mov cx,6 add si,arp_shwaddr add di,arp_thwaddr rep movsb ; ; Load source hardware address in ARP reply packet. ; mov si,bx mov di,dx add di,arp_shwaddr mov es:[di],word ptr 0000h add di,2 mov cx,4 add si,arp_tprotaddr ; Set Ethernet address in ARP reply ; to target IP address rep movsb ; ; Set opcode to REPLY. ; mov di,dx mov word ptr es:[di].arp_opcode,0200h ; ; Give ARP reply packet that has been constructed to the application ; layer. ; pop si pop ds pop cx assume ds:nothing call recv_copy assume ds:code arp_reply_1: pop cx pop di pop si pop es pop ds ret public set_address set_address: ;enter with ds:si -> Ethernet address, CX = length of address. ;exit with nc if okay, or cy, dh=error if any errors. assume ds:nothing ret rcv_mode_3: ;receive mode 3 is the only one we support, so we don't have to do anything. ret public set_multicast_list set_multicast_list: ;enter with ds:si ->list of multicast addresses, ax = number of addresses, ; cx = number of bytes. ;return nc if we set all of them, or cy,dh=error if we didn't. mov dh,NO_MULTICAST stc ret public terminate terminate: ret public reset_interface reset_interface: ;reset the interface. ret ;called when we want to determine what to do with a received packet. ;enter with cx = packet length, es:di -> packet type. extrn recv_find: near ;called after we have copied the packet into the buffer. ;enter with ds:si ->the packet, cx = length of the packet. extrn recv_copy: near extrn count_in_err: near extrn count_out_err: near extrn dwordout: near extrn error: near public recv recv: ;called from the recv isr. All registers have been saved, and ds=cs. ;Upon exit, the interrupt will be acknowledged. assume ds:code ret public nbint ; MAP nbint proc far push ds ; ; Set data segment to code segment so that we can reference local ; variables. ; push cs pop ds ; ; Retrieve size of received packet ; mov cx,[bx].ncb_length ; ; Check return code. If there was an error then don't process the ; packet any further. ; mov al,[bx].ncb_retcode cmp al,0 ; ok jnz bad_nbint ; ; Add Ethernet header. As well, ensure that minimum packet size is 60 ; bytes; some application packages actually check for minimum packet size. ; add cx,14 cmp cx,60 jge recv_next mov cx,60 recv_next: push si ;save si in case we reject it. push bx push cx movseg es,cs mov di, offset ip_type mov dl,cs:driver_class call recv_find ;look up our type. pop cx pop bx pop si mov ax,es ;is this pointer null? or ax,di jne nb_next jmp skip_copy nb_next: push bx push cx push es push di ; ; Fix up the Ethernet header added to the incoming packet. ; call fix_header ; ; Copy the received packet into buffer allocated by the application ; software. ; sub cx,14 mov si,[bx].ncb_buffer.offs rep movsb pop si pop ds pop cx assume ds:nothing call recv_copy push cs pop ds assume ds:code pop bx skip_copy: mov [bx].ncb_length,MAX_DG ; reestablish dg-length ; ; Set up to receive another packet. Construct "receive datagram" ; NCB. ; push ds pop es int 5ch ; ; Check return code. Print error indication if NETBIOS does not ; accept NCB. ; mov al,[bx].ncb_retcode ; JS added return code cmp al,0ffh jz nbint_pending_ok1 mov al,'?' call tty add ax,32 call tty mov al,'.' call tty nbint_pending_ok1: jmp short nbint_done bad_nbint: add ax,32 call tty mov al,'R' call tty jmp skip_copy nbint_done: pop ds iret nbint endp ; ; Set destination and source addressess and packet type in an ; Ethernet header. ; fix_header: ; ; Set destination address. ; push cx mov ax,0000h stosw mov ax,ip_adress.offs ;was 0c3c4h stosw mov ax,ip_adress.segm ;was 0c2cch stosw ; ; Set source address. NCB callname contains the string "TCPIP" + ; source host IP address. Extract host IP address and copy into ; Ethernet header as the source address. ; mov ax,0000h stosw mov ax,word ptr [bx].ncb_callname+5 stosw mov ax,word ptr [bx].ncb_callname+7 stosw ; ; Set packet type to IP. ; mov ax, 0008h stosw pop cx ret public nb_stop nb_stop: ; unregister name push cs pop es lea bx,nbrcv1 mov [bx].ncb_command,NCB_DELNAME ; mov al,lana_num ; mov [bx].ncb_lana_num,al int 5ch cmp al,0 jz good_delete add ax,32 call tty mov al,'I' call tty good_delete: ret public tty tty: push bx mov ah,14 int 10h pop bx ret ip_to_nbname: ; call with es:di = *ncb_name ; bx and dx = ip_address mov cx,5 mov si,offset prefix rep movsb mov [di],bx mov [di+2],dx ret public timer_isr timer_isr: ;if the first instruction is an iret, then the timer is not hooked iret ;any code after this will not be kept. Buffers used by the program, if any, ;are allocated from the memory between end_resident and end_free_mem. public end_resident,end_free_mem end_resident label byte end_free_mem label byte public usage_msg usage_msg db "usage: nb [options] <packet_int_no> <ip.ad.dr.ess> [receive queue size]",CR,LF,'$' public copyright_msg copyright_msg db "Packet driver for a netbios device, version ",'0'+version,CR,LF,'$' db "Portions Copyright 1990, Michael Haberler",CR,LF,'$' ip_adress_name db "IP Adress ",'$' rq_size_name db "Receive Queue ",'$' bad_name_msg db " bad returncode from nb add_name",CR,LF,'$' bad_rcv_msg db " bad returncode from nb receive dg",CR,LF,'$' good_name_msg db " good returncode from nb add_name",CR,LF,'$' good_rcv_msg db " good returncode from nb receive dg",CR,LF,'$' temp_dw dw ? extrn set_recv_isr: near ;enter with si -> argument string, di -> word to store. ;if there is no number, don't change the number. extrn get_number: near extrn skip_blanks: near ;-> the assigned Ethernet address of the card. extrn rom_address: byte public parse_args parse_args: ;exit with nc if all went well, cy otherwise. call skip_blanks cmp al,'-' ;did they specify a switch? jne not_switch cmp byte ptr [si+1],'g' ;did they specify '-g'? je got_gw_switch stc ;no, must be an error. ret got_gw_switch: mov gw_switch,1 add si,2 ;skip past the switch's characters. jmp parse_args ;go parse more arguments. not_switch: mov di, offset temp_dw mov bx, offset ip_adress_name call get_number mov ax,temp_dw mov byte ptr ip_adress+0,al inc si mov di, offset temp_dw mov bx, offset ip_adress_name call get_number mov ax,temp_dw mov byte ptr ip_adress+1,al inc si mov di, offset temp_dw mov bx, offset ip_adress_name call get_number mov ax,temp_dw mov byte ptr ip_adress+2,al inc si mov di, offset temp_dw mov bx, offset ip_adress_name call get_number mov ax,temp_dw mov byte ptr ip_adress+3,al ret public etopen etopen: ;if all is okay, ; mov bx,offset nbsend lea bx,nbsend mov [bx].ncb_command,NCB_ADDNAME mov al,lana_num mov [bx].ncb_lana_num,al push ds push cs push cs pop ds pop es push bx lea di,nbsend.ncb_name mov bx,ip_adress mov dx,ip_adress+2 call ip_to_nbname pop bx ;fake up an Ethernet address. mov word ptr rom_address[0],word ptr 0000h mov bx,cs:ip_adress mov word ptr rom_address[4],bx mov bx,cs:ip_adress+2 mov word ptr rom_address[2],bx ; mov di, offset nbsend.ncb_name ; mov cx,16 ;mike: ; mov al, [di] ; call tty ; inc di ; dec cx ; jnz mike mov cx,16 mov di,offset nbrcv1.ncb_name mov si,offset nbsend.ncb_name rep movsb mov cx,16 mov di,offset nbrcv2.ncb_name mov si,offset nbsend.ncb_name rep movsb int 5ch ; add_name, -> returns rc in al cmp al,0 jz good_name mov dx,0 mov ah,0 call dwordout mov dx,offset bad_name_msg pop ds stc ret good_name: ; mov dx,offset good_name_msg ; call say mov al,[bx].ncb_num mov local_ncb_num,al mov [bx].ncb_command,NCB_SDATAGRAM ;set send command code ; start receive operations ; mov bx,offset nbrcv1 lea bx,nbrcv1 mov al,NCB_RDATAGRAM+NCB_NOWAIT ;set rcv command mov [bx].ncb_command,al mov al,local_ncb_num mov [bx].ncb_num,al mov ax,MAX_DG mov [bx].ncb_length,ax mov ax,ds mov [bx].ncb_buffer.segm,ax mov [bx].ncb_buffer.offs,offset rcv_buffer1 mov [bx].ncb_post.segm,ax mov [bx].ncb_post.offs,offset nbint mov al,lana_num mov [bx].ncb_lana_num,al int 5ch cmp al,0ffh jz pending_ok1 cmp al,00h jnz bad_init pending_ok1: mov dx,offset good_rcv_msg mov ah,9 int 21h pop ds clc ret ;if we got an error, bad_init: mov ah,0 mov dx,0 call dwordout call nb_stop pop ds mov dx,offset bad_rcv_msg stc ret public print_parameters print_parameters: ret say: mov ah,9 int 21h ret code ends end