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Assembly Source File | 1990-07-27 | 35.6 KB | 1,685 lines

version equ 2 ; Packet driver to simulate Ethernet on Novell IPX protocol. ; ; Paul Kranenburg ; Department of Computer Science ; University of Leiden ; Niels Bohrweg 1 ; PO Box 9512 ; 2300 RA Leiden ; The Netherlands ; e-mail: pk@cs.leidenuniv.nl ; ; ; File: ipxpkt.asm ; ; ; General description: ; ; Take destination from the Ethernet packet and feed it to IPX ; in the Event Control Block Immediate Address field. ; ; IPX packets are 576 bytes at most, 30 are needed for the IPX header ; leaving 546 bytes of user data. Another 4 bytes are used to describe ; fragments. ; If NO_OF_SND_BUFS is set to 1, this yields an MTU for this driver of 528. ; (546 - 4 - sizeof(Ether header)[=14]). ; If IPX trail is used another 32 bytes are lost (MTU = 496). ; ; If NO_OF_SND_BUFS is set to 3, the Ethernet packet is broken into at most ; 3 fragments. These are tagged with a Fragment id and shipped. ; ; On reception, fragments are kept on a linked list ordered by fragment number ; and keyed by source node address and fragment id. ; An IPX event is scheduled to allow for timeout of pending reassembly queues. ; ; If all fragments are reassembled, the client is called to provide a buffer for ; the packet. ; ; [ To save on buffer space, the driver could conceivably do with some minimum ; number of buffers and call recv_find as soon as a fragment arrives, copy ; the contents, and only call recv_copy when all fragments have arrived. However, ; I don't think there is a way to notify the client in case a fragment gets lost.] ; ; In this code, the number of receive buffers (NO_OF_RCV_BUFS) has been set ; to 6 (a wild guess). ; This driver has yet to be tested in a gateway under heavy load. One probably ; needs more buffers in this case. ; ; Buffer space for the receive buffers is allocated after the "end_resident" ; label. There is a potential problem here: we start listening for packets ; using these buffers while still in the initialisation code, which is overlaid ; by the receive buffers. This is why interrupts are turned off wherever possible. ; ; ; CHANGELOG. ; ; 07/16/90 ; Decoupled simulated ethernet address from IPX node address in routing tables, ; allowing for unique addresses in nets like ARCNET with only a one byte ; node address. ; Thanks to Robert Roll and Reid Sweatman of the University of Utah ; for pointing this out. ; IPXPKT accepts a command line option of the from `-n [<no_bytes>]' to specify ; the number of significant bytes in the IPX node address. If less then EADDR_LEN, ; the presented ethernet address will get supplemented with some bytes from ; the IPX node address to (hopefully) create a unique address among the nodes ; in the network involved. ; If `<no_bytes>' is omitted, the number of significant bytes will be set as the ; number of bytes left in the node address after stripping leading zeroes. ; ; 07/12/90 ; Reorganize initialisation; do GET_ADDESS etc., before posting LISTEN's ; ; 05/16/90 ; New socket number used when TRAIL enabled (0x6181). ; Enables co-existance of original and "TRAIL" versions of packet driver. ; You can start both an old and a new experimental driver in your gateway, ; but watch those IP subnet addresses. ; ; 05/15/90 ; Corrected byte-order of IPX socket. ; Socket number NOT actually changed (== 0x6180, in dynamic range) ; ; 05/15/90 ; Add dummy GET_LOCAL_TARGET call to force some traffic to IPX from a bridge. ; This will get the local net address to IPX. Define TRY_GET_LOCAL_TARGET if ; you want to use this. ; ; 05/07/90 ; Add statistics gathering on various table lookups. ; Compile option STAT. Use ipxstat.c for display (derivative of version 5.0 `stat.c'). ; ; 05/04/90 ; Fixed case of register trashing in route code. ; Add IPX 32-byte trailer for bridge routing. ; Compile option TRAIL. ; ; 05/03/90 ; Add routing table. ; Net/node addresses of incoming packets are put routing table along with ; immediate address field in ecb struct. ; Outgoing packets have the their net- and immediate address looked up ; in the table with the node address as key. ; Special case: broadcast packets are sent with packet type 0x14 through ; permanent entry in routing table. ; ; 05/03/90 ; **REMOVED** 07/17/90 ; Add compile option to declare receive buffer space at compile time. ; Compile option NOT_SO_SAVE; if defined, buffer space is allocated beginning at ; `end_resident' else space is reserved by compiler ; ; 05/02/90 ; Merge `fill_ipxhdr' into `route'. ; ;DEBUG EQU 1 TRY_GET_LOCAL_TARGET EQU 1 STAT EQU 1 TRAIL EQU 1 ETH_CONSTR EQU 3 include defs.asm MAX_IPX_LEN = 576 ; Maximum packet size that can be ; shipped through IPX ifdef TRAIL IP_socket = 08161h ; Socket allocated for Blue book Ether ; on IPX with TRAILS (BYTE-SWAPPED) else IP_socket = 08061h ; Socket allocated for ; Blue book Ether on IPX (BYTE-SWAPPED) endif PEP = 4 ; Packet Exchange Packet (ipx_type) GBP = 014h ; Global Broadcast Packet (ipx_type) RTE_TICK = 37 ; Interval between calls to rte_ticker, ; 37 is approx. 2 seconds ipx_header struc ipx_chksum dw ? ; Checksum, network byte order ipx_len dw ? ; Packet length, " ipx_prot db ? ; Transport protocol ipx_type db ? ; Packet type ipx_destnet db 4 dup(?) ; Destination network ipx_destnode db 6 dup(?) ; Destination node ipx_destsock dw ? ; Destination socket ipx_srcnet db 4 dup(?) ; Source network ipx_srcnode db 6 dup(?) ; Source node ipx_srcsock dw ? ; Source socket ifdef TRAIL ipx_trail db 8 * 4 dup(?) ; IPX gateway trail endif ipx_header ends frag_dscr struc frag_addr dd ? ; Fragment address frag_size dw ? ; Fragment size frag_dscr ends ecb struc ecb_link dd ? ; ecb_esr dd ? ; Event Service Routine ecb_inuse db ? ; In Use field ecb_cmplt db ? ; Completion Code ecb_sock dw ? ; Socket Number ecb_ipxwork db 4 dup (?) ; IPX reserved workspace ecb_drvwork db 12 dup (?) ; Driver reserved workspace ecb_ia db 6 dup (?) ; Immediate Address ecb_fragcnt dw ? ; Fragment count ;ecb_dscr = $ ; Start of Fragment descriptor list ecb ends aes_ecb struc aes_link dd ? ; aes_esr dd ? ; Event Service Routine aes_inuse db ? ; In Use field aes_work db 5 dup (?) ; Driver reserved workspace aes_ecb ends ether_frag struc ef_fragno db ? ; This fragment number ef_fragtot db ? ; Total number of fragments comprising the packet ef_fragid dw ? ; Fragment Id ether_frag ends queue_entry struc q_aes db (size aes_ecb) dup(?); AES structure, used for reassembly timeouts q_filler db 0 q_count db 0 ; Number of fragments currently queued here q_net db SIZE ipx_srcnet dup(?) q_node db SIZE ipx_srcnode dup(?) ; Source node q_fragid dw ? ; Fragment Id q_len dw ? ; Total length of user data queued here q_ecb dd ? ; Ecb pointer to fragment queue_entry ends u_buf struc u_ecb db (size ecb) dup(?) u_ipx_frag db (size frag_dscr) dup(?) u_frag_frag db (size frag_dscr) dup(?) u_data_frag db (size frag_dscr) dup(?) u_ipx db (size ipx_header) dup(?) u_ether_frag db (size ether_frag) dup(?) ;u_data LABEL BYTE u_buf ends MAX_PAYLOAD = MAX_IPX_LEN - SIZE ipx_header - SIZE ether_frag ;routing table entry rt_ent struc rt_ether db EADDR_LEN dup(?) ; Ethernet address of target: lookup key rt_net db SIZE ipx_srcnet dup(?) ; Net address of target rt_node db SIZE ipx_srcnode dup(?) ; Node address of target rt_gate db SIZE ecb_ia dup(?) ; First hop on route to above rt_x_pkt db ? ; IPX packet type to send packet with ;;rt_trail db ? ; This node uses IPX trail rt_age dw ? ; Usage indicator for this entry rt_ent ends print$ macro string ;---------------------------------------; ; sends $ terminated string to screen ; ;---------------------------------------; push dx mov ah,9 mov dx,offset &string& ; print $ terminated string int 21h pop dx endm ; ipx function numbers OPEN_SOCKET = 0 CLOSE_SOCKET = 1 GET_LOCAL_TARGET = 2 SEND_PACKET = 3 LISTEN = 4 SCHEDULE_EVENT = 5 CANCEL_EVENT = 6 SCHEDULE_SPECIAL_EVENT = 7 GET_NODE_ADDRESS = 9 RELINQUISH = 0Ah call_ipx macro opcode,reg1,reg2,reg3,reg4,reg5,reg6,reg7,reg8 irp N, <reg1,reg2,reg3,reg4,reg5,reg6,reg7,reg8> ifnb <N> push N endif endm mov bx, opcode ;better be save here and use Code segment explicitly call cs:IPXentry irp N, <reg8,reg7,reg6,reg5,reg4,reg3,reg2,reg1> ifnb <N> pop N endif endm endm repmov macro count rept (count) / 2 movsw endm rept (count) MOD 2 movsb endm endm ifdef STAT statinc macro loc local a ;affects flags register (NOT carry) inc cs:loc jnz a inc cs:loc+2 a: endm else statinc macro loc endm endif code segment word public assume cs:code, ds:code IPXentry dd ? FragmentID dw ? my_net_address db 4 dup(?) ; contiguous 10 byte addrss-area as IPX wants it my_node_address db 6 dup(?) no_bytes dw EADDR_LEN, 0 ; number of significant bytes in IPX node address ; set as command line option. init_cmplt dw 0 dummy db 10 dup(0ffh) ; dummy addr/socket dw 05104h ; what socket to use (???) db 6 dup(?) ; returned address NO_OF_FRAGMENTS = 3 NO_OF_RCV_BUFS = 6 NO_OF_SND_BUFS = 3 NO_OF_QUEUES = NO_OF_RCV_BUFS ; ???? NO_OF_RTES = 30 reass_queues queue_entry NO_OF_QUEUES dup(<>) rcv_bufs u_buf NO_OF_RCV_BUFS dup(<>) snd_bufs u_buf NO_OF_SND_BUFS dup(<>) ifdef STAT ;; org ($ + 1) and 0fffeh ; keep ID string an even number of bytes (including terminating zero and count) db "RTE_TABL", 0, NO_OF_RTES endif rte rt_ent NO_OF_RTES dup(<>) rte_end dw 0 rte_scache dw 0 rte_rcache dw 0 rte_aes aes_ecb <> ifdef STAT ;; org ($ + 1) and 0fffeh db "IPXSTAT", 0 ; keep this string an even number of bytes queue_full dw 2 dup(0) route_drop dw 2 dup(0) scache_miss dw 2 dup(0) rcache_miss dw 2 dup(0) route_loops dw 2 dup(0) route_lookups dw 2 dup(0) endif ;------------------------------------------------------------------------------- ; ; local functions ; ; A NOTE on style: ; ; the functions below seem to liberally load and reload pointers into ; a register pair involving the ds segment register. ; In fact, ds almost always contains the code segment as "assumed" above. ; Also, the distinction between pointers to ecb's and ubuf's / queue's is not made ; most of the time. This is alright as long as the ecb structures remain the first ; ones declared in u_buf and queue. ; Need to work out a consistent register usage some day... ; find_queue proc near ; ; Find/allocate a queue-entry where an ether fragment can be stored. ; On entry: es:di -> source node address. ; dx == fragment Id. ; Out: si == 0 if no queue entry available, ; otherwise: (ds:)si -> allocated queue-entry. ; Must be called with interrupts disabled. push cx push bx mov cx, NO_OF_QUEUES lea si, reass_queues mov bx, 0 fq_loop: mov al, [si].q_count or al, al jnz fq_1 or bx, bx ; jne fq_2 ; remember first entry not in use mov bx, si ; jmp short fq_2 fq_1: mov ax, cx ; can use AX in stead of `push cx' push si push di add si, q_net mov cx, SIZE q_net + SIZE q_node cld repe cmpsb pop di pop si mov cx, ax jne fq_2 cmp dx, [si].q_fragid jne fq_2 jmp short fq_x fq_2: add si, SIZE queue_entry loop fq_loop mov si, bx ifdef STAT or si, si jnz fq_stat_1 statinc queue_full fq_stat_1: endif fq_x: pop bx pop cx ret find_queue endp enqueue proc near ; Queue an etherpacket fragment on appropriate queue ; On entry: es:si -> received ecb. ; cx = length of data in this fragment ; Out: carry set if no space available. ; zero flag set if packet on queue complete. ; ds:si -> queue_entry on which fragment was queued. push si push es mov ax, 0 mov es:[si].u_ecb.ecb_link.offs, ax ; clear link-field mov es:[si].u_ecb.ecb_link.segm, ax mov di, si ; es:di -> ecb mov dx, es:[si].u_ether_frag.ef_fragid push di ; lea di, es:[si].u_ipx.ipx_srcnode lea di, es:[si].u_ipx.ipx_srcnet call find_queue pop di or si, si jnz enq_0 add sp, 4 stc ret enq_0: mov dl, es:[di].u_ether_frag.ef_fragno mov dh, es:[di].u_ether_frag.ef_fragtot cmp [si].q_count, 0 jne enq_3 ;this is the first fragment we receive call rte_enter ; record their route pop [si].q_ecb.segm pop [si].q_ecb.offs mov [si].q_len, cx mov [si].q_count, 1 cmp dh, 1 ; jne enq_1 ; short cut if fragment count == 1. clc ret ;initialise queue structure a bit more... enq_1: mov ax, es:[di].u_ether_frag.ef_fragid mov [si].q_fragid, ax ;copy source node address mov bx, SIZE q_net + SIZE q_node - 1 enq_2: ; mov al, es:[di+bx].u_ipx.ipx_srcnode mov al, es:[di+bx].u_ipx.ipx_srcnet mov ds:[si+bx].q_net, al sub bx, 1 jnc enq_2 mov ax, cs mov [si].q_aes.aes_esr.segm, ax mov [si].q_aes.aes_esr.offs, offset reass_timeout mov ax, ds mov es, ax mov ax, 2 ; two ticks to timeout call_ipx SCHEDULE_SPECIAL_EVENT,si,dx cmp dh, [si].q_count clc ret ; add ecb to existing queue, keep list ordered by fragment number. enq_3: lea ax, [si].q_ecb push ax ; put link field address on stack push ds les di, [si].q_ecb enq_4: mov ax, es ; are we at end of list? or ax, di jz enq_5 cmp dl, es:[di].u_ether_frag.ef_fragno ; link after this frag? jb enq_5 add sp, 4 ; lea ax, es:[di].u_ecb.ecb_link ; push ax push di ; push `prev'-link push es les di, es:[di].u_ecb.ecb_link ; load `next'-link jmp enq_4 ; enter here with two addresses on the stack: ; 1) address of ecb to link in ; 2) address of link field after which to link ; es:di contains the "next" link. enq_5: mov ax, es ; temp = next mov bx, di pop es ; get prev pop di pop es:[di].segm ; prev->next = this one pop es:[di].offs les di, es:[di] ; load `this one' mov es:[di].u_ecb.ecb_link.segm, ax ; `this one'->next = temp mov es:[di].u_ecb.ecb_link.offs, bx add [si].q_len, cx ; update total queued data inc [si].q_count ; update fragcount cmp dh, [si].q_count ; return `zero' if all there clc ret enqueue endp dequeue proc near ; Send reassembled packet to client and reschedule receive buffers. ; On entry: ds:si -> queue. mov cx, [si].q_len les di, [si].q_ecb les di, es:[di].u_data_frag.frag_addr add di, 2 * EADDR_LEN push si call recv_find pop si mov ax, es or ax, di jz deq_2 mov dh, [si].q_count mov cx, [si].q_len push si ; save our queue address push ds push di ; save their buffer address push es push cx lds si, ds:[si].q_ecb cld ;all set, es:di -> user buffer, ds:si -> first fragment ;??? save count and source pointer for call to recv_copy deq_1: mov cx, ds:[si].u_ipx.ipx_len xchg cl, ch sub cx, (SIZE ipx_header + SIZE ether_frag) push si push ds lds si, ds:[si].u_data_frag.frag_addr rep movsb pop ds pop si lds si, ds:[si].u_ecb.ecb_link dec dh jnz deq_1 pop cx ; recover packet length and address pop ds ; for completion call pop si ; call recv_copy pop ds ; recover queue address pop si ; deq_2: mov ax, ds mov es, ax call_ipx CANCEL_EVENT,si push si mov dh, [si].q_count les si, ds:[si].q_ecb deq_3: mov bx, es:[si].ecb_link.offs mov cx, es:[si].ecb_link.segm call listen_proc mov si, bx mov es, cx ; les si, es:[si].u_ecb.ecb_link dec dh jnz deq_3 pop si mov [si].q_count, 0 ret dequeue endp reass_timeout proc far ; Called by AES when reassembly timeout occurs. ; On entry: es:si pointer to ecb. ; push ds mov ax, cs mov ds, ax push si push es mov dh, es:[si].q_count les si, es:[si].q_ecb reass_to_3: mov bx, es:[si].ecb_link.offs mov cx, es:[si].ecb_link.segm call listen_proc mov si, bx mov es, cx dec dh jnz reass_to_3 pop es pop si mov es:[si].q_count, 0 pop ds ret reass_timeout endp receiver proc far ; ; On entry: es:si -> ecb. ; push ds mov ax, cs mov ds, ax mov al, es:[si].u_ecb.ecb_cmplt or al, al jnz receiver_err cmp es:[si].u_ecb.ecb_fragcnt, NO_OF_FRAGMENTS jne receiver_err ;IPX receives its own broadcasts because ;source and destination sockets are the same ;if ours, ignore mov ax, si mov di, si add di, ecb_ia lea si, my_node_address mov cx, SIZE my_node_address cld repe cmpsb mov si, ax jz receiver_x mov cx, es:[si].u_ipx.ipx_len xchg cl, ch sub cx, (SIZE ipx_header + SIZE ether_frag) jbe receiver_err call enqueue jc receiver_err jnz rec_1 call dequeue rec_1: pop ds cli ret receiver_err: call count_in_err receiver_x: call listen_proc ; post listen again pop ds cli ; must return with interrupts disabled, says Novell. ret receiver endp listen_proc proc near ; ; Post to u_buf for reception. ; On entry: es:si -> receive-ecb ; push bx ;fill in ecb mov es:[si].u_ecb.ecb_esr.offs, offset receiver mov ax, cs mov word ptr es:[si].u_ecb.ecb_esr.segm, ax mov es:[si].u_ecb.ecb_sock, IP_socket call_ipx LISTEN,es,si,di,dx,cx pop bx ret listen_proc endp rte_ticker proc far ; ; ESR service routine called by AES ; Ages all entries in routing table ; executes entirely with disabled interrupts ; ; On entry: es:si -> ecb push ds mov ax, cs mov ds, ax mov dx, rte_end lea di, rte rtick_1: add di, SIZE rt_ent ; leave broadcast entry alone cmp di, dx jae rtick_done mov ax, [di].rt_age add ax, 1 jo rtick_1 mov [di].rt_age, ax jmp rtick_1 ;re-schedule ecb rtick_done: mov ax, RTE_TICK call_ipx SCHEDULE_SPECIAL_EVENT pop ds ret rte_ticker endp rte_enter proc near ; ; Enter route to table ; On entry: es:di -> ecb ; assume ds:nothing, es:nothing push bx push cx push dx push si push ds push di push es les di, es:[di].u_data_frag.frag_addr add di, EADDR_LEN ; es:di -> src node address mov bx, rte_rcache ; global, last succesful entry call rte_find ; will set DS to code seg jc ert_1 ifdef STAT cmp rte_rcache, si je ert_stat_1 statinc rcache_miss ert_stat_1: endif mov rte_rcache, si jmp ert_x ; we already have route to src ert_1: ;not in table, find free entry ; mov ax, cs ; mov ds, ax ; ds == code lea dx, rte add dx, SIZE rte ; dx -> beyond rte mov bx, rte_end ; add rte_end, SIZE rt_ent ; take the chance cmp bx, dx ; check whether table full jb ert_2 sub rte_end, SIZE rt_ent ; undo guess call kill_route ; will leave freed entry in bx ert_2: ;insert addresses in ecb and ipx into routing table ; $%#@, must swap registers for string operations ; cld mov ax, ds mov cx, es mov es, ax mov ds, cx mov si, di ; ds:si -> source address mov di, bx ; es:di -> rt_ent add di, rt_ether repmov <SIZE rt_ether> pop ds ; recover ecb from stack pop si ; push si push ds mov ax, si add si, u_ipx + ipx_srcnet ; record source net+node repmov <SIZE rt_net + SIZE rt_node> mov si, ax ; restore si to start of ecb add si, ecb_ia ; record immediate address repmov <SIZE rt_gate> mov es:[bx].rt_x_pkt, PEP ; packet type mov es:[bx].rt_age, 10 ; usage count (XXX) ert_x: pop es pop di pop ds pop si pop dx pop cx pop bx ret rte_enter endp kill_route proc near ; ; Delete entry in route table with highest rt_age field ; Out: bx -> route entry freed ; push cx push dx push di lea di, rte add di, SIZE rt_ent ; leave broadcast entry alone mov dx, rte_end mov bx, di mov cx, 0 krt_1: cmp di, dx je krt_done mov ax, [di].rt_age cmp ax, cx jbe krt_2 mov cx, ax mov bx, di krt_2: add di, SIZE rt_ent jmp krt_1 krt_done: ifdef STAT statinc route_drop endif pop di pop dx pop cx ret kill_route endp rte_find proc near ; ; Find a route for address ; On entry: es:di -> target address we are looking for (EADDR_LEN bytes) ; bx -> entry to start search ; Out: ds:si -> route table entry, or carry set if not found ; assume ds:code, es:nothing push bx push dx mov ax, cs ; cs == code segment mov ds, ax mov dx, rte_end ; global, points to first invalid rte entry mov ax, bx ; ax == stopper cld frt_1: ifdef STAT statinc route_loops endif mov si, bx ; add si, rt_ether ; si -> rt_ether field (= key) of current rte-entry push di ; save di mov cx, SIZE rt_ether repe cmpsb pop di je frt_x ; compare ok, report succes add bx, SIZE rt_ent ; next rte-entry cmp bx, dx jb frt_2 lea bx, rte ; end of valid entries, wrap around frt_2: cmp bx, ax jne frt_1 stc ; back where we started, report failure ;found, update cache and prepare output frt_x: mov si, bx ifdef STAT statinc route_lookups endif pop dx pop bx ret rte_find endp route proc near ; ; Determine where to send the packet ; On entry: ds:si -> user data, es:di -> ecb ; assume ds:nothing, es:nothing push bx push cx push ds push si ;find entry in routing table, in: es:di, out: ds:si -> pointer to table entry push di push es mov ax, ds ; mov es, ax ; es:di -> target address mov di, si ; mov bx, rte_scache ; global, last succesful entry call rte_find pop es pop di jc route_x ifdef STAT cmp rte_scache, si je route_stat_1 statinc scache_miss route_stat_1: endif mov rte_scache, si ; remember this entry mov ax, ds:[si].rt_age ; sub ax, 1 ; decrement usage jc route_1 mov ds:[si].rt_age, ax route_1: cld mov bx, di ; remember ecb in BX ifdef TRAIL ;clear ipx trail fields add di, u_ipx.ipx_trail mov ax, 0 mov cx, (SIZE ipx_trail) / 2 rep stosw mov di, bx endif ;fill in packet type and destination socket mov al, ds:[si].rt_x_pkt mov es:[di].u_ipx.ipx_type, al ;PEP mov es:[di].u_ipx.ipx_destsock, IP_socket ;fill in full destination adress mov ax, si ; save si add si, rt_net add di, u_ipx.ipx_destnet repmov <SIZE ipx_destnet + SIZE ipx_destnode> mov si, ax ; restore si, di mov di, bx ; ;fill in immediate address add di, ecb_ia add si, rt_gate repmov <SIZE ecb_ia> mov di, bx ; route_x: pop si pop ds pop cx pop bx ret route endp public int_no int_no db 0,0,0,0 ;must be four bytes long for get_number. public driver_class, driver_type, driver_name, driver_function, parameter_list driver_class db 1 ;from the packet spec driver_type db 1 ;from the packet spec driver_name db 'IPX',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 if NO_OF_SND_BUFS eq 1 dw MAX_PAY_LOAD - 2 * EADDR_LEN - 2 ;MTU, including MAC headers else dw GIANT ;MTU, including MAC headers endif 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 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 public send_pkt send_pkt: ;enter with ds:si -> packet, cx = packet length. ;exit with nc if ok, or else cy if error, dh set to error number. assume ds:nothing push es push di mov ax, cs mov es, ax ;first, compute number of fragments needed, keep in dx mov dx, 0 mov ax, cx snd_1: inc dx sub ax, MAX_PAYLOAD jnc snd_1 ;can we handle this amount? cmp dx, NO_OF_SND_BUFS jbe snd_frags_ok snd_err: call count_out_err pop di pop es mov dh, CANT_SEND stc ret snd_frags_ok: lea di, snd_bufs push cx mov cx, dx mov bx, 0 mov al, 0 snd_free_chk: or al, es:[di+bx].u_ecb.ecb_inuse add bx, SIZE u_buf loop snd_free_chk pop cx or al, al jnz snd_err mov dh, dl mov dl, 1 mov bx, 0 inc FragmentID push di snd_next_frag: ; ; dh = total number of fragments to send ; dl = current fragment ; bx = offset into client buffer (ds:si) for this fragment ; cx = bytes to go ; es:di = address of current fragment's ecb ; ;determine next hop call route ; XXX, should be done for first fragment only! jnc snd_frag1 pop di jmp snd_err snd_frag1: ;fill in ecb mov ax, 0 mov es:[di].u_ecb.ecb_esr.offs, ax mov es:[di].u_ecb.ecb_esr.segm, ax mov es:[di].u_ecb.ecb_sock, IP_socket mov es:[di].u_ether_frag.ef_fragtot, dh mov es:[di].u_ether_frag.ef_fragno, dl mov ax, FragmentID mov es:[di].u_ether_frag.ef_fragid, ax mov ax, ds mov es:[di].u_data_frag.frag_addr.segm, ax mov ax, MAX_PAYLOAD sub cx, ax jnc snd_frag2 add ax, cx snd_frag2: mov es:[di].u_data_frag.frag_size, ax push si add si, bx mov es:[di].u_data_frag.frag_addr.offs, si add bx, ax ; ; es:si -> ecb to ship ; mov si, di call_ipx SEND_PACKET,es,di,dx,cx,bx pop si ; ds:si -> client buffer once more add di, SIZE u_buf ; next send buffer inc dl cmp dl, dh jbe snd_next_frag pop di ;simple timeout on sends mov cx, 0ffffh snd_wait: ;wait until sends are done sti mov bx, 0 push cx mov ch, 0 mov cl, dh ; dh still has fragment count mov al, 0 snd_wait1: or al, es:[di+bx].u_ecb.ecb_inuse add bx, SIZE u_buf loop snd_wait1 pop cx or al, al jz snd_done call_ipx RELINQUISH,es,di,dx,cx loop snd_wait ;arrive here on timeout, cancel IPX sends mov ch, 0 mov cl, dh mov si, di snd_cancel: call_ipx CANCEL_EVENT,es,si,cx add si, SIZE u_buf loop snd_cancel jmp snd_err snd_done: ;check completion status of send buffers mov bx, 0 mov ch, 0 mov cl, dh mov al, 0 snd_done1: or al, es:[di+bx].u_ecb.ecb_cmplt add bx, SIZE u_buf loop snd_done1 or al, al jz snd_ok jmp snd_err snd_ok: pop di pop es ret public get_address get_address: ;get the address of the interface. ;enter with es:di -> place to get the address, cx = size of address buffer. ;exit with nc, cx = actual size of address, or cy if buffer not big enough. assume ds:code cmp cx, EADDR_LEN jnb ga_0 stc ret ga_0: push si cmp init_cmplt, 1 jnc ga_1 call listen_init mov init_cmplt, 1 ga_1: lea si, my_node_address ; first copy IPX node address cld repmov <EADDR_LEN> mov cx, EADDR_LEN ; if not significant enough, cmp no_bytes, 0ffffh ; magic in no_bytes? jne ga_3 lea bx, my_node_address ; they don't know mov dx, bx ; figure out something for no_bytes add dx, SIZE my_node_address ; savety mov no_bytes, EADDR_LEN ga_2: cmp word ptr [bx], 0 jnz ga_3 dec no_bytes inc bx cmp bx, dx je ga_3 jmp ga_2 ga_3: sub cx, no_bytes ; copy some of IPX net address jcxz get_addr_x cmp cx, SIZE my_net_address jbe ga_4 mov cx, SIZE my_net_address ga_4: lea si, my_net_address sub di, EADDR_LEN ;next are three different methods for constructing the reported ethernet address ;from a less-than-6-bytes-long IPX node adress and the IPX net address. if ETH_CONSTR eq 1 rep movsb elseif ETH_CONSTR eq 2 ga_21: mov bx, SIZE my_net_address - 1 mov al, [si+bx] stosb dec bx loop ga_21 elseif ETH_CONSTR eq 3 push di push si push es mov ax, ds mov es, ax lea di, dummy repmov <SIZE my_net_address> pop es pop si pop di lea si, dummy ga_3_loop: mov bx, 0 mov dx, 0 mov al, 0 ga_31: cmp bx, SIZE my_net_address jz ga_33 mov ah, [si+bx] cmp al, ah jnc ga_32 mov al, ah mov dx, bx ga_32: inc bx jmp ga_31 ga_33: stosb mov bx, dx mov word ptr [si+bx], 0 loop ga_3_loop endif get_addr_x: mov cx, EADDR_LEN pop si clc ret listen_init proc near ;and start listening on each receive buffer push si push cx push es mov ax, cs mov es, ax mov cx, NO_OF_RCV_BUFS lea si, rcv_bufs li_1: call listen_proc add si, SIZE u_buf loop li_1 pop es pop cx pop si ret listen_init endp 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 es:di ->list of multicast 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 get_multicast_list get_multicast_list: ;return with nc, es:di ->list of multicast addresses, cx = number of bytes. ;return cy, NO_ERROR if we don't remember all of the addresses ourselves. ;return cy, NO_MULTICAST if we don't implement multicast. mov dh,NO_MULTICAST stc ret public reset_interface reset_interface: ;reset the interface. assume ds:code 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 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 recv_exiting recv_exiting: ;called from the recv isr after interrupts have been acknowledged. ;Only ds and ax have been saved. assume ds:nothing ret public terminate terminate: ;called when this driver should cease operation. assume ds:nothing ;close socket, outstanding listens should be cancelled automatically mov dx, IP_socket call_ipx CLOSE_SOCKET ; mov ax, cs ; mov es, ax ; mov cx, NO_OF_RCV_BUFS ; lea si, rcv_bufs ; ;terminate_1: ; call_ipx CANCEL_EVENT,es,si,cx ; add si, SIZE u_buf ; loop terminate_1 ret ;any code after this will not be kept after initialization. end_resident label byte public usage_msg usage_msg db "usage: ipx_pkt [-n] [-d] [-w] <packet_int_no>",CR,LF,'$' public copyright_msg copyright_msg db "Packet driver for IPX, version ",'0'+version,CR,LF db "Portions Copyright 1990, P. Kranenburg",CR,LF,'$' no_ipx_msg db "IPX not present",CR,LF, '$' wrong_sock_msg db "IPX has no good socket",CR,LF, '$' ifdef DEBUG debugmsg1 db "Doing a GET TARGET",CR,LF, '$' debugmsg2 db "Past GET TARGET",CR,LF, '$' debugmsg3 db "Past GET ADDRESS",CR,LF, '$' endif 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 public parse_args parse_args: call skip_blanks cmp byte ptr [si], CR je parse_args_x cmp byte ptr [si], '-' jne parse_err cmp byte ptr [si+1],'n' ; '-n'? je parse_args_1 parse_err: stc ;no, must be an error. ret parse_args_1: add si, 2 call skip_blanks cmp byte ptr [si], CR jne parse_args_2 mov no_bytes, 0ffffh ;try heuristic jmp parse_args_x parse_args_2: mov di,offset no_bytes call get_number cmp no_bytes, 0 jb parse_err cmp no_bytes, EADDR_LEN ja parse_err parse_args_x: clc ret public etopen etopen: ;first see if IPX is there mov ax, 07A00h int 2fh cmp al, 0ffh je ipx_is_here print$ no_ipx_msg stc ret ipx_is_here: mov ax, es mov IPXentry.offs, di mov IPXentry.segm, ax ;close socket first, since "head" won't notify us on termination mov dx, IP_socket call_ipx CLOSE_SOCKET ;next open socket mov al, 0ffh ; stay open until explicitly closed mov dx, IP_socket call_ipx OPEN_SOCKET or al, 0 jnz wrong_socket cmp dx, IP_socket je good_socket ;close socket and exit wrong_socket: call_ipx CLOSE_SOCKET print$ wrong_sock_msg stc ret good_socket: ;init send buffer fragment list mov ax, cs mov es, ax mov cx, NO_OF_SND_BUFS lea si, snd_bufs et_1: mov es:[si].u_ecb.ecb_fragcnt, NO_OF_FRAGMENTS mov bx, si ; bx = offset ipx_header add bx, u_ipx mov es:[si].u_ipx_frag.frag_addr.offs, bx mov es:[si].u_ipx_frag.frag_addr.segm, ax mov es:[si].u_ipx_frag.frag_size, SIZE ipx_header mov bx, si ; bx = offset ether_frag add bx, u_ether_frag mov es:[si].u_frag_frag.frag_addr.offs, bx mov es:[si].u_frag_frag.frag_addr.segm, ax mov es:[si].u_frag_frag.frag_size, SIZE ether_frag ; ; NOTE: u_data_frag is initialised send_pkt with address of user data buffer ; add si, SIZE u_buf loop et_1 ;initialise receive buffer ipx data fragment addresses ;and start listening on each mov cx, NO_OF_RCV_BUFS lea si, rcv_bufs lea di, end_resident et_2: mov es:[si].u_ecb.ecb_fragcnt, NO_OF_FRAGMENTS mov bx, si add bx, u_ipx mov es:[si].u_ipx_frag.frag_addr.offs, bx mov es:[si].u_ipx_frag.frag_addr.segm, ax mov es:[si].u_ipx_frag.frag_size, SIZE ipx_header mov bx, si add bx, u_ether_frag mov es:[si].u_frag_frag.frag_addr.offs, bx mov es:[si].u_frag_frag.frag_addr.segm, ax mov es:[si].u_frag_frag.frag_size, SIZE ether_frag mov es:[si].u_data_frag.frag_addr.offs, di ; di = offset data buffer mov es:[si].u_data_frag.frag_addr.segm, ax mov es:[si].u_data_frag.frag_size, MAX_PAYLOAD add si, SIZE u_buf add di, MAX_PAYLOAD loop et_2 ;heuristic to force network traffic which seems to necessary before ;the GET_NODE_ADDRESS call will work properly (boo,hiss) ;get our address sti lea si, my_net_address call_ipx GET_NODE_ADDRESS,es,si lea si, my_net_address cmp byte ptr es:[si], 0 jne et_3 cmp byte ptr es:[si+1], 0 jne et_3 cmp byte ptr es:[si+2], 0 jne et_3 cmp byte ptr es:[si+3], 0 jne et_3 ifdef TRY_GET_LOCAL_TARGET ifdef DEBUG push es print$ debugmsg1 pop es endif lea si, dummy mov di, si add di, 12 call_ipx GET_LOCAL_TARGET,es ifdef DEBUG push es print$ debugmsg2 pop es endif ;get our address lea si, my_net_address call_ipx GET_NODE_ADDRESS,es,si ifdef DEBUG push es push si print$ debugmsg3 pop si pop es endif endif et_3: ;initialise routing table with the broadcast address cld lea di, rte mov rte_end, di ; rte_end = second entry add rte_end, SIZE rt_ent ; mov rte_scache, di ; rte_cache = first (and only) entry mov rte_rcache, di ; mov es:[di].rt_age, 0 mov es:[di].rt_x_pkt, GBP ; broadcast packet type ;; mov es:[di].rt_trail, 1 ; uses trail add di, rt_ether ; broadcast address mov al, 0ffh mov cx, SIZE rt_ether rep stosb push ds mov ax, cs mov ds, ax mov cx, SIZE rt_net rep movsb ; net field set from my_net_address pop ds mov al, 0ffh mov cx, SIZE rt_node + SIZE rt_gate rep stosb ; all FF's ;schedule periodic aging of route table entries lea si, rte_aes mov ax, cs mov es:[si].aes_esr.segm, ax mov es:[si].aes_esr.offs, offset rte_ticker mov ax, RTE_TICK call_ipx SCHEDULE_SPECIAL_EVENT, es ;if all is okay, mov dx,offset end_resident add dx, NO_OF_RCV_BUFS * MAX_PAYLOAD clc ret ;if we got an error, stc ret public print_parameters print_parameters: ret code ends end