📄 dnsr.asm
字号:
;
; DNS Domain name -> IP lookup
;
; Compile with FASM for Menuet
;
; If you like, you camd change the DNS server default by changing the
; IP address in the dnsServer string.
; Enabling debugging puts the received response to the
; debug board
DEBUGGING_ENABLED equ 1
DEBUGGING_DISABLED equ 0
DEBUGGING_STATE equ DEBUGGING_DISABLED
use32
org 0x0
db 'MENUET00' ; 8 byte id
dd 38 ; required os
dd START ; program start
dd I_END ; program image size
dd 0x100000 ; required amount of memory
dd 0x00000000 ; reserved=no extended header
START: ; start of execution
mov eax,40 ; Report events
mov ebx,10000111b ; Stack 8 + defaults
int 0x40
mov dword [prompt], p1
mov dword [promptlen], p1len - p1 ; 'waiting for command'
call draw_window ; at first, draw the window
still:
mov eax,10 ; wait here for event
int 0x40
cmp eax,1 ; redraw request ?
jz red
cmp eax,2 ; key in buffer ?
jz key
cmp eax,3 ; button in buffer ?
jz button
jmp still
red: ; redraw
call draw_window
jmp still
key: ; Keys are not valid at this part of the
mov eax,2 ; loop. Just read it and ignore
int 0x40
jmp still
button: ; button
mov eax,17 ; get id
int 0x40
cmp ah,1 ; button id=1 ?
jnz noclose
; close socket before exiting
mov eax, 53
mov ebx, 1
mov ecx, [socketNum]
int 0x40
mov eax,0xffffffff ; close this program
int 0x40
noclose:
cmp ah,3 ; Resolve address?
jnz noresolve
mov dword [prompt], p5
mov dword [promptlen], p5len - p5 ; display 'Resolving'
call draw_window
call translateData ; Convert domain & DNS IP address
call resolveDomain
jmp still
noresolve:
cmp ah,4
jz f1 ; Enter domain name
cmp ah,5
jz f2 ; enter DNS Server IP
jmp still
f1:
mov [addr],dword query
mov [ya],dword 35
jmp rk
f2:
mov [addr],dword dnsServer
mov [ya],dword 35+16
rk:
mov ecx,26
mov edi,[addr]
mov al,' '
rep stosb
call print_text
mov edi,[addr]
f11:
mov eax,10
int 0x40
cmp eax,2
jz fbu
jmp still
fbu:
mov eax,2
int 0x40 ; get key
shr eax,8
cmp eax,8
jnz nobs
cmp edi,[addr]
jz f11
sub edi,1
mov [edi],byte ' '
call print_text
jmp f11
nobs:
cmp eax,dword 31
jbe f11
cmp eax,dword 95
jb keyok
sub eax,32
keyok:
mov [edi],al
call print_text
add edi,1
mov esi,[addr]
add esi,26
cmp esi,edi
jnz f11
jmp still
print_text:
mov eax,13
mov ebx,103*65536+26*6
mov ecx,[ya]
shl ecx,16
mov cx,8
mov edx,0x224466
int 0x40
mov eax,4
mov ebx,103*65536
add ebx,[ya]
mov ecx,0xffffff
mov edx,[addr]
mov esi,26
int 0x40
ret
;***************************************************************************
; Function
; translateData
;
; Description
; Coverts the domain name and DNS IP address typed in by the user into
; a format suitable for the IP layer.
;
; The ename, in query, is converted and stored in dnsMsg
; The DNS ip, in dnsServer, is converted and stored in dnsIP
;
;***************************************************************************
translateData:
; first, get the IP address of the DNS server
; Then, build up the request string.
xor eax, eax
mov dh, 10
mov dl, al
mov [dnsIP], eax
mov esi, dnsServer
mov edi, dnsIP
mov ecx, 4
td003:
lodsb
sub al, '0'
add dl, al
lodsb
cmp al, '.'
je ipNext
cmp al, ' '
je ipNext
mov dh, al
sub dh, '0'
mov al, 10
mul dl
add al, dh
mov dl, al
lodsb
cmp al, '.'
je ipNext
cmp al, ' '
je ipNext
mov dh, al
sub dh, '0'
mov al, 10
mul dl
add al, dh
mov dl, al
lodsb
ipNext:
mov [edi], dl
inc edi
mov dl, 0
loop td003
; Build the request string
mov eax, 0x00010100
mov [dnsMsg], eax
mov eax, 0x00000100
mov [dnsMsg+4], eax
mov eax, 0x00000000
mov [dnsMsg+8], eax
; domain name goes in at dnsMsg+12
mov esi, dnsMsg + 12 ; location of label length
mov edi, dnsMsg + 13 ; label start
mov edx, query
mov ecx, 12 ; total string length so far
td002:
mov [esi], byte 0
inc ecx
td0021:
mov al, [edx]
cmp al, ' '
je td001 ; we have finished the string translation
cmp al, '.' ; we have finished the label
je td004
inc byte [esi]
inc ecx
mov [edi], al
inc edi
inc edx
jmp td0021
td004:
mov esi, edi
inc edi
inc edx
jmp td002
; write label len + label text
td001:
mov [edi], byte 0
inc ecx
inc edi
mov [edi], dword 0x01000100
add ecx, 4
mov [dnsMsgLen], ecx
ret
;***************************************************************************
; Function
; resolveDomain
;
; Description
; Sends a question to the dns server
; works out the IP address from the response from the DNS server
;
;***************************************************************************
resolveDomain:
; Get a free port number
mov ecx, 1000 ; local port starting at 1000
getlp:
inc ecx
push ecx
mov eax, 53
mov ebx, 9
int 0x40
pop ecx
cmp eax, 0 ; is this local port in use?
jz getlp ; yes - so try next
; First, open socket
mov eax, 53
mov ebx, 0
mov edx, 53 ; remote port - dns
mov esi, [dnsIP]
int 0x40
mov [socketNum], eax
; write to socket ( request DNS lookup )
mov eax, 53
mov ebx, 4
mov ecx, [socketNum]
mov edx, [dnsMsgLen]
mov esi, dnsMsg
int 0x40
; Setup the DNS response buffer
mov eax, dnsMsg
mov [dnsMsgLen], eax
; now, we wait for
; UI redraw
; UI close
; or data from remote
ctr001:
mov eax,10 ; wait here for event
int 0x40
cmp eax,1 ; redraw request ?
je ctr003
cmp eax,2 ; key in buffer ?
je ctr004
cmp eax,3 ; button in buffer ?
je ctr005
; Any data in the UDP receive buffer?
mov eax, 53
mov ebx, 2
mov ecx, [socketNum]
int 0x40
cmp eax, 0
je ctr001
; we have data - this will be the response
ctr002:
mov eax, 53
mov ebx, 3
mov ecx, [socketNum]
int 0x40 ; read byte - block (high byte)
; Store the data in the response buffer
mov eax, [dnsMsgLen]
mov [eax], bl
inc dword [dnsMsgLen]
if DEBUGGING_STATE = DEBUGGING_ENABLED
call debug_print_rx_ip
end if
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