page ,132 if 0 /*++ Copyright (c) 1991 Microsoft Corporation Module Name: redir.asm Abstract: This module contains the stub redir TSR code for NT VDM net support Author: Richard L Firth (rfirth) 05-Sep-1991 Environment: Dos mode only Revision History: 05-Sep-1991 rfirth Created --*/ endif ; ; DOS include files ; .xlist .xcref include dossym.inc ; includes MS-DOS version etc include pdb.inc ; PSP defines include syscall.inc ; AssignOper include enumapis.inc ; Local_API_GetRedirVersion, etc. include segorder.inc ; load order of 'redir' segments include rdrsvc.inc ; BOP and SVC macros/dispatch codes include rdrmisc.inc ; miscellaneous definitions include debugmac.inc ; debug display macros include asmmacro.inc ; jumps which may be short or near include int5c.inc ; Int to be used for pseudo network adapter .cref .list ; ; Misc. local manifests ; LOAD_STACK_SIZE equ 256 ; ; Define externals in resident code and data ; ResidentCodeStart extrn OldMultHandler:dword extrn MultHandler:near extrn Old2aHandler:dword extrn Int2aHandler:near extrn Old5cHandler:dword extrn Int5cHandler:near extrn OldNetworkHandler:dword extrn IntNetworkHandler:near extrn dwPostRoutineAddress:dword if DEBUG extrn Old21Handler:dword extrn CheckInt21Function5e:near endif ResidentCodeEnd ResidentDataStart extrn LanRootLength:word extrn LanRoot:byte ResidentDataEnd InitStack segment stack para 'stack' dw LOAD_STACK_SIZE dup (?) top_of_stack equ $ InitStack ends InitDataStart ; ; pull in messages. Kept in a separate file to make internationalisation easier ; include redirmsg.inc public ComputerName ComputerName db LM20_CNLEN + 1 dup (?) DefaultLanRoot db "C:\LANMAN.DOS",0 DEFAULT_LANROOT_LENGTH equ $-DefaultLanRoot InitDataEnd InitCodeStart assume cs:InitCode assume ds:nothing assume es:nothing assume ss:nothing public start start proc near ; ; when we start up we could be on any old PC - even an original, so don't ; assume anything other than a model-T processor ; .8086 ; ; let's do the decent thing and create a stack. This way we're covered ; mov dx,InitStack mov ss,dx ; disables ints until after next ins. mov sp,offset top_of_stack assume ss:InitStack ; ; may as well set the data segment while we're at it - all paths set it sooner ; or later. NOTE: es will point to the PSP until we change it! ; mov dx,InitData mov ds,dx assume ds:InitData ; ; first off, get the DOS version. If we're not running on NT (VDM) then this ; TSR's not going to do much, so exit. Exit using various methods, depending ; on the DOS version (don't you hate compatibility?) ; mov ah,30h int 21h jc ancient_version ; version not even supported, forcrissake ; ; version is 2.0 or higher. Check it out. al = major#, ah = minor# ; cmp al,major_version jne invalid_version ; ; what do you know? We're actually running on NT (unless some evil programmer ; has pinched int 21h/30h and done something execrable with it!). We'd better ; do something... ; Also: at this point we know we're on at a 386, so lets enable some 286 ; instructions to be generated. Eh? you justifiably ponder - is this a typo? ; Unfortunately, SoftPc only emulates the lowly 286 processor. We need to wait ; until Microsoft has paid Insignia lots of money before they can afford some ; new brains who will then dutifully provide us with full 386+ emulation (maybe) ; .286c mov ax,(AssignOper SHL 8) + Local_API_RedirGetVersion int 21h ; is redir already loaded? jnc already_here ; yep ; ; OK, the redir is not already loaded - we're in business. Get and set the ; various interrupt vectors, Calculate the amount of space we want to keep, ; free up any unused space (like the environment segment), display a message ; in the DEBUG version, then terminate and stay resident. Remember: at this ; point we expect ES to point at the PSP ; @@: call InstallInterruptHandlers ; OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD ;; ;; Initialize VDM DOS memory window address (in virtual DLC driver). ;; The memory window is used for the async Netbios, DLC and ;; named pipe post routines. ;; ; ; push es ; PSP ; mov bx,ResidentCode ; mov es,bx ; ; assume es:ResidentCode ; ;; ;; now that VDMREDIR support is a DLL, we can fail initialization on the 32-bit ;; side if the DLL cannot be loaded, or the entry points not found. In this case ;; we will fail to load redir.exe, rather than constantly returning ;; ERROR_NOT_SUPPORTED every time we make a redir BOP ;; ; ; mov bx,offset dwPostRoutineAddress ; SVC SVC_VDM_WINDOW_INIT ; pop es ; es back to PSP ; jmpc initialization_error ; OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD assume es:nothing ; ; free the environment segment ; mov es,es:[PDB_environ] mov ah,49h int 21h ; free environment segment if DEBUG ifdef PROLIX DbgPrintString <"Redir successfully loaded",13,10> endif endif ; OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD ;; ;; now perform the BOP which will let the 32-bit redir support know that the ;; DOS redirector TSR is successfully loaded. This must be the last action - ;; we cannot fail installation after this point (unless we call the BOP to ;; uninitialize 32-bit VDM redir support ;; ; ; mov bx,seg ComputerName ; mov es,bx ; ; assume es:seg ComputerName ; ; mov bx,offset ComputerName ; initialization returns the computer name ; mov cx,size ComputerName ; which will be gettable using int 21/ah=5e ; SVC SVC_RDRINITIALIZE ; jmpc initialization_error ; 32-bit DLL failed (?) ; OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD ; DbgBreakPoint ; check computer name returned ; ; set the computer name returned from the 32-bit side ; if DEBUG ifdef PROLIX DbgPrintString <"Set computer name here",13,10> endif endif if 0 mov ax,5e01h ; set machine name xor cx,cx ; cx is 'user num' int 21h endif ; ; do initialisation things - set the lanroot to the default if not otherwise ; specified ; mov ax,InitData mov ds,ax assume ds:InitData mov ax,ResidentData mov es,ax assume es:ResidentData mov LanRootLength,DEFAULT_LANROOT_LENGTH mov si,offset DefaultLanRoot mov di,offset LanRoot cld mov cx,DEFAULT_LANROOT_LENGTH/2 rep movsw if (DEFAULT_LANROOT_LENGTH and 1) movsb endif ; ; finally terminate and stay resident ; mov dx,ResidentEnd sub dx,ResidentStart ; number of paragraphs in resident code add dx,10h ; additional for PSP (PDB) ; DbgBreakPoint if DEBUG ifdef PROLIX DbgPrintString "Staying resident with " DbgPrintHexWord dx DbgPrintString " paragraphs. Load seg is ",NOBANNER mov ah,62h int 21h DbgPrintHexWord bx DbgPrintString " current seg is ",NOBANNER DbgPrintHexWord cs DbgCrLf endif endif mov ax,3100h int 21h ; terminate and stay resident ; ; here if the MS-DOS version check (Ah=30h) call is not supported ; ancient_version: mov dx,InitData mov ds,dx assume ds:InitData mov dx,offset bad_ver_msg mov ah,9 ; cp/m-style write to output int 21h ; ; safe exit: what we really want to do here is INT 20H, but when you do this, ; CS must be the segment of the PSP of this program. Knowing that CD 20 is ; embedded at the start of the PSP, the most foolproof way of doing this is ; to jump (using far return) to the start of the PSP ; push es xor ax,ax push ax retf ; terminate ; ; we are running on a version of DOS >= 2.00, but its not NT, so we still can't ; help. Display the familiar message and exit, but using a less programmer- ; hostile mechanism ; invalid_version: mov dx,offset bad_ver_msg mov cx,BAD_VER_MSG_LEN jmp short print_error_message_and_exit ; OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD ;; ;; if we cannot initialize 32-bit support (because we can't find/load the DLL) ;; then put back the hooked interrupt vectors as they were when this TSR started, ;; display a message and fail to load the redir TSR ;; ; ;initialization_error: ; call RestoreInterruptHandlers ; mov dx,offset cannot_load_msg ; mov cx,CANNOT_LOAD_MSG_LEN ; jmps print_error_message_and_exit ; OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD OLD ; ; The DOS version's OK, but this TSR is already loaded ; already_here: mov dx,offset already_loaded_msg mov cx,ALREADY_LOADED_MSG_LEN print_error_message_and_exit: mov bx,1 ; bx = stdout handle mov ah,40h ; write to handle int 21h ; write (cx) bytes @ (ds:dx) to stdout mov ax,4c01h ; terminate program int 21h ; au revoir, cruel environment start endp ;******************************************************************************* ;* ;* InstallInterruptHandlers ;* ;* Sets the interrupt handlers for all the ints we use - 2a, 2f, 5c ;* and NETWORK_INTERRUPT (0e) ;* ;* ENTRY es = PSP segment ;* ds = ;* ;* EXIT OldMultHandler contains the original interrupt 2f vector ;* Old2aHandler contains the original interrupt 2a vector ;* Old5cHandler contains the original interrupt 5c vector ;* OldNetworkHandler contains the original interrupt 0e vector ;* ;* RETURNS nothing ;* ;* ASSUMES ;* ;******************************************************************************* InstallInterruptHandlers proc push es ; PSP segment - destroyed by INT 21/35h push ds ; ; note: if we use ResidentCode here, explicitly, instead of seg OldMultHandler, ; then we can leave out an extraneous load of ds for the ISR address ; mov dx,ResidentCode mov ds,dx assume ds:ResidentCode mov ax,352fh ; get current INT 2Fh vector int 21h mov word ptr OldMultHandler,bx mov word ptr OldMultHandler+2,es mov dx,offset ResidentCode:MultHandler mov ax,252fh int 21h ; set INT 2Fh vector to our handler ; ; we have to pinch int 2a too - certain parts of the net libraries perform a ; net check using a presence check on 2ah ; mov ax,352ah int 21h mov word ptr Old2aHandler,bx mov word ptr Old2aHandler+2,es mov dx,offset ResidentCode:Int2aHandler mov ax,252ah int 21h ; ; we have to pinch int 5c for Netbios and DLC ; mov ax,355ch int 21h mov word ptr Old5cHandler,bx mov word ptr Old5cHandler+2,es mov dx,offset ResidentCode:Int5cHandler mov ax,255ch int 21h ; ; we have to pinch int NETWORK_INTERRUPT for Netbios and DLC ; mov ax,3500h OR NETWORK_INTERRUPT int 21h mov word ptr OldNetworkHandler,bx mov word ptr OldNetworkHandler+2,es mov dx,offset ResidentCode:IntNetworkHandler mov ax,2500h OR NETWORK_INTERRUPT int 21h ;if DEBUG ;; ;; get the int 21 handler too so we can find out if anyone's calling the ;; (unsupported) int 21/ah=5e ;; ; ; mov ax,3521h ; int 21h ; mov word ptr Old21Handler,bx ; mov word ptr Old21Handler+2,es ; mov dx,offset ResidentCode:CheckInt21Function5e ; mov ax,2521h ; int 21h ;endif pop ds ; restore segment registers pop es ret InstallInterruptHandlers endp ;******************************************************************************* ;* ;* RestoreInterruptHandlers ;* ;* Resets the interrupt handlers for all the ints we use - 2a, 2f, 5c ;* and NETWORK_INTERRUPT (0e). Called in the event we cannot complete ;* installation ;* ;* ENTRY OldMultHandler, Old2aHandler, Old5cHandler, OldNetworkHandler ;* contain the interrupt vectors from before redir.exe was loaded ;* ;* EXIT Original interrupt vectors are restored ;* ;* RETURNS nothing ;* ;* ASSUMES ;* ;******************************************************************************* RestoreInterruptHandlers proc push ds assume ds:nothing push es mov dx,ResidentCode mov es,dx assume es:ResidentCode lds dx,OldMultHandler mov ax,252fh int 21h ; set INT 2Fh vector to previous handler lds dx,Old2aHandler mov ax,252ah int 21h lds dx,Old5cHandler mov ax,255ch int 21h lds dx,OldNetworkHandler mov ax,2500h OR NETWORK_INTERRUPT int 21h ;if DEBUG ; lds dx,Old21Handler ; mov ax,2521h ; int 21h ;endif pop es pop ds ret RestoreInterruptHandlers endp InitCodeEnd end start