ip65 technical reference
File : ip65/cifs.s
a simple NETBIOS over TCP server
aka "Common Internet File System"
refs: RFC1001, RFC1002, "Implementing CIFS" - http://ubiqx.org/cifs/
functions
| function | description |
|---|
| cifs_l1_decode | given a 'level 1 encoded' hostname, decode to ASCII .
inputs:
AX: pointer to encoded hostname to be decoded
outputs:
AX: pointer to decoded hostname (will be 16 byte hostname, right padded with spaces, nul terminated)
|
| cifs_l1_encode | given an ASCII (or PETSCII) hostname, convert to
canonical 'level 1 encoded' form.
only supports the default scope (' ' : 0x20)
inputs:
AX: pointer to null terminated hostname to be encoded
outputs:
AX: pointer to decoded hostname
|
| cifs_start | start a CIFS (SMB) server process, and advertise the specified hostname on the local LAN
inputs:
AX = ptr to hostname to be used
outputs:
none
|
implementation
;a simple NETBIOS over TCP server
;aka "Common Internet File System"
;
; refs: RFC1001, RFC1002, "Implementing CIFS" - http://ubiqx.org/cifs/
.include "../inc/common.i"
.ifndef KPR_API_VERSION_NUMBER
.define EQU =
.include "../inc/kipper_constants.i"
.endif
DEFAULT_CIFS_CMD_BUFFER = $6800
DEFAULT_SMB_RESPONSE_BUFFER=$6000
.export cifs_l1_encode
.export cifs_l1_decode
.export cifs_start
.import copymem
.importzp copy_src
.importzp copy_dest
.import cfg_ip
.import output_buffer
.importzp udp_data
.import udp_send
.import udp_inp
.importzp udp_data
.import udp_send_dest
.import udp_send_src_port
.import udp_send_dest_port
.import udp_send_len
.importzp ip_src
.importzp ip_dest
.import ip_data
.import ip_inp
.import tcp_close
.import tcp_listen
.import tcp_callback
.import tcp_inbound_data_length
.import tcp_inbound_data_ptr
.import tcp_send
.import tcp_send_data_len
.import ip65_process
.import udp_add_listener
.import udp_callback
nbns_txn_id = 0
nbns_opcode=2
nbns_flags_rcode=3
nbns_qdcount=4
nbns_ancount=6
nbns_nscount=8
nbns_arcount=10
nbns_question_name=12
nbns_service_type=43
nbns_my_ip=64
nbns_registration_message_length=68
;given an ASCII (or PETSCII) hostname, convert to
;canonical 'level 1 encoded' form.
;
;only supports the default scope (' ' : 0x20)
;inputs:
; AX: pointer to null terminated hostname to be encoded
;outputs:
; AX: pointer to decoded hostname
cifs_l1_encode:
stax copy_src
lda #0
tax
sta hostname_buffer+32
@empty_buffer_loop:
lda #$43
sta hostname_buffer,x
inx
lda #$41
sta hostname_buffer,x
inx
cpx #$20
bmi @empty_buffer_loop
ldy #0
ldx #0
@copy_loop:
lda (copy_src),y
beq @done
lsr
lsr
lsr
lsr
clc
adc #$41
sta hostname_buffer,x
inx
lda (copy_src),y
and #$0F
clc
adc #$41
sta hostname_buffer,x
inx
iny
cpx #$1D
bmi @copy_loop
@done:
ldax #hostname_buffer
rts
;given a 'level 1 encoded' hostname, decode to ASCII .
;
;inputs:
; AX: pointer to encoded hostname to be decoded
;outputs:
; AX: pointer to decoded hostname (will be 16 byte hostname, right padded with spaces, nul terminated)
cifs_l1_decode:
stax copy_src
ldy #0
ldx #0
@decode_loop:
lda (copy_src),y
sec
sbc #$41
asl
asl
asl
asl
sta hi_nibble
iny
lda (copy_src),y
sec
sbc #$41
clc
adc hi_nibble
sta hostname_buffer,x
iny
inx
cpx #$10
bmi @decode_loop
lda #0
sta hostname_buffer,x
ldax #hostname_buffer
rts
;start a CIFS (SMB) server process, and advertise the specified hostname on the local LAN
;
;inputs:
;AX = ptr to hostname to be used
;outputs:
; none
cifs_start:
;save the hostname in 'raw' form
stax copy_src
ldax #raw_local_hostname
stax copy_dest
ldax #$0f
stx raw_local_hostname+15
jsr copymem
;set up callbacks
ldax #nbns_callback
stax udp_callback
ldax #137
jsr udp_add_listener
ldax #nbns_callback
stax udp_callback
ldax #137
jsr udp_add_listener
ldax #raw_local_hostname
jsr cifs_l1_encode
ldx #0
@copy_hostname_loop:
lda hostname_buffer,x
sta local_hostname,x
inx
cpx #$21
bmi @copy_hostname_loop
jsr cifs_advertise_hostname
jsr cifs_advertise_hostname
ldax #nb_session_callback
stax tcp_callback
@listen:
ldax #-4 ;start at -4, to skip the NBT header length
stax cifs_cmd_length
ldax cifs_cmd_buffer
stax cifs_cmd_buffer_ptr
ldax #139
stx connection_closed
jsr tcp_listen
@loop:
inc $d020 ;FIXME
jsr ip65_process
lda connection_closed
beq @loop
jmp @listen
rts
;broadcast a Name Registration Request message to the local LAN
cifs_advertise_hostname:
; advertise the 'server' service for own hostname
;overwrite the hostname in 'DNS compressed form'
;we assume this hostname ends with <20>
lda #$20 ;indicates what follows is a netbios name
sta output_buffer+nbns_question_name
ldx #0
@copy_hostname_loop:
lda local_hostname,x
sta registration_request_servername+1,x
inx
cpx #$21
bmi @copy_hostname_loop
jsr @send_nbns_message
;copy our encode hostname to the host announcment
ldax #local_hostname
stax copy_src
ldax #host_announce_hostname
stax copy_dest
ldax #$20
jsr copymem
;copy our raw hostname to the host announcment
ldax #raw_local_hostname
stax copy_src
ldax #host_announce_servername
stax copy_dest
ldax #$10
jsr copymem
;copy the local IP address to the 'sender' field of the host announcment
ldx #03
@copy_sending_address_loop:
lda cfg_ip,x
sta host_announce_my_ip,x
dex
bpl @copy_sending_address_loop
ldax #138
stax udp_send_dest_port
stax udp_send_src_port
ldax #host_announce_message_length
stax udp_send_len
ldax #host_announce_message
jsr udp_send
rts
@send_nbns_message:
;copy the local IP address
ldx #03
@copy_my_address_loop:
lda cfg_ip,x
sta nbns_my_ip,x
dex
bpl @copy_my_address_loop
;send to the broadcast address
lda #$ff
ldx #03
@copy_broadcast_address_loop:
sta udp_send_dest,x
dex
bpl @copy_broadcast_address_loop
ldax #137
stax udp_send_dest_port
stax udp_send_src_port
ldax #nbns_registration_message_length
stax udp_send_len
ldax #registration_request
jsr udp_send
rts
nbns_callback:
lda udp_inp+udp_data+nbns_opcode
and #$f8 ;mask the lower three bits
beq @name_request
rts
@name_request:
;this is a NB NAME REQUEST.
;is it a unicast message?
ldx #3
@check_unicast_loop:
lda ip_inp+ip_dest,x
cmp cfg_ip,x
bne @not_unicast
dex
bpl @check_unicast_loop
jmp @looking_for_us
@not_unicast:
;is it looking for our local hostname?
ldax #udp_inp+udp_data+nbns_question_name+1
stax copy_src
ldy #0
@cmp_loop:
lda (copy_src),y
cmp local_hostname,y
bne @not_us
iny
cpy #30
bne @cmp_loop
@looking_for_us:
;this is a request for our name!
;copy the txn id
ldax udp_inp+udp_data ;first 2 bytes of data are txn id
stax netbios_name_query_response
;set the sender & recipients IP address
ldx #03
@copy_address_loop:
lda ip_inp+ip_src,x
sta udp_send_dest,x
lda cfg_ip,x
sta netbios_name_query_response_ip,x
dex
bpl @copy_address_loop
;copy our encoded hostname
ldax #local_hostname
stax copy_src
ldax #netbios_name_query_response_hostname
stax copy_dest
ldax #30
jsr copymem
;copy the service identifier - last 2 bytes in the query hostname
.import eth_inp
ldax eth_inp+$55
stax netbios_name_query_response_hostname+30
ldax #137
stax udp_send_dest_port
stax udp_send_src_port
ldax #netbios_name_query_response_length
stax udp_send_len
ldax #netbios_name_query_response
jmp udp_send
@not_us:
rts
nb_session_callback:
lda tcp_inbound_data_length+1
cmp #$ff
bne @not_eof
@eof:
inc connection_closed
@done:
rts
@not_eof:
;copy this chunk to our input buffer
ldax cifs_cmd_buffer_ptr
stax copy_dest
ldax tcp_inbound_data_ptr
stax copy_src
ldax tcp_inbound_data_length
jsr copymem
;increment the pointer into the input buffer
clc
lda cifs_cmd_buffer_ptr
adc tcp_inbound_data_length
sta cifs_cmd_buffer_ptr
lda cifs_cmd_buffer_ptr+1
adc tcp_inbound_data_length+1
sta cifs_cmd_buffer_ptr+1
;increment the cmd buffer length
clc
lda cifs_cmd_length
adc tcp_inbound_data_length
sta cifs_cmd_length
lda cifs_cmd_length+1
adc tcp_inbound_data_length+1
sta cifs_cmd_length+1
;have we got a complete message?
ldax cifs_cmd_buffer
stax copy_src
ldy #3
lda (copy_src),y
cmp cifs_cmd_length
bne @not_got_full_message
dey
lda (copy_src),y
cmp cifs_cmd_length+1
bne @not_got_full_message
;we have a complete message!
ldy #0
lda (copy_src),y ;get the message type
cmp #$81 ;is it a session request?
bne @not_session_request
ldax #positive_session_response_packet_length
stax tcp_send_data_len
ldax #positive_session_response_packet
jsr tcp_send
jmp @message_handled
@not_session_request:
cmp #$00 ;is it a session message?
bne @not_session_message
;this SHOULD be a SMB - best check the header
ldy #4
lda (copy_src),y ;get the message data
cmp #$FF ;start of SMB header
bne @not_smb
iny
lda (copy_src),y ;get the message data
cmp #'S' ;start of SMB header
bne @not_smb
jsr smb_handler
jmp @message_handled
;this doesn't look like a NBT session message or SMB, so give up
@not_session_message:
@not_smb:
jsr tcp_close
jmp @eof
@message_handled:
;reset ready for next message on this connection
ldax #-4 ;start at -4, to skip the NBT header length
stax cifs_cmd_length
ldax cifs_cmd_buffer
stax cifs_cmd_buffer_ptr
@not_got_full_message:
rts
smb_handler:
; at this point, copy_src points to an SMB block encapsulated in an NBT session header
clc
lda copy_src
adc #4
sta smb_ptr ;skip past the NBT header
lda copy_src+1
adc #00
sta smb_ptr+1
ldy #8
lda (copy_src),y ;get the SMB type
cmp #$72
bne @not_negotiate_protocol
jmp @negotiate_protocol
@not_negotiate_protocol:
;we assume it is an "AndX" command
sta andx_opcode
lda smb_ptr
clc
adc #$20 ;skip over SMB header
sta andx_ptr
lda smb_ptr+1
adc #00
sta andx_ptr+1
jsr start_smb_response
@parse_andx_block:
ldax andx_ptr
stax copy_src
lda andx_opcode
cmp #$ff
beq @done_all_andx_blocks
ldy #0
@andx_opcode_scan:
lda andx_opcodes,y
beq @opcode_not_found
cmp andx_opcode
beq @opcode_found
iny
iny
iny
jmp @andx_opcode_scan
@opcode_found:
lda andx_opcodes+1,y
sta andx_handler+1
lda andx_opcodes+2,y
sta andx_handler+2
jsr andx_handler
jmp @go_to_next_andx_block
@opcode_not_found:
jsr unknown_andx
@go_to_next_andx_block:
ldy #3
lda (copy_src),y ;get the AndX offset low byte
clc
adc smb_ptr
sta andx_ptr
iny
lda (copy_src),y ;get the AndX offset high byte
adc smb_ptr+1
sta andx_ptr+1
ldy #1
lda (copy_src),y ;get the subsequent AndX opcode
sta andx_opcode
jmp @parse_andx_block
@done_all_andx_blocks:
ldax smb_response_length
inx ;FIXME! this is to force wireshark to dump as SMB even tho packet is incorrect
stax tcp_send_data_len
ldax smb_response_buffer
jsr tcp_send
rts
@negotiate_protocol:
;copy the request TID,PID,UID,MID into the response
ldy #28 ;offset of TID from start of message
ldx #0
:
lda (copy_src),y
sta negotiate_protocol_response_tid,x
inx
iny
cpx #8
bne :-
lda #$ff
sta dialect_index
sta dialect_index+1
clc
lda cifs_cmd_buffer
adc #$26
sta copy_src
lda cifs_cmd_buffer+1
adc #$00
sta copy_src+1
ldy #$0
@dialect_scan_loop:
iny
bmi @end_of_dialects ;if we go to offset $80, we have gone too far
lda dialect_index
cmp #$10 ;if we've scanned more than $10 dialects, something is wrong
beq @end_of_dialects
lda (copy_src),y
cmp #$02
bne @test_dialect
inc dialect_index
jmp @dialect_scan_loop
@test_dialect:
tya
clc
adc copy_src
sta copy_src
bcc :+
inc copy_src+1
:
ldy #0
@test_dialect_loop:
lda (copy_src),y
cmp preferred_dialect_id,y
bne @dialect_scan_loop
iny
cpy #preferred_dialect_id_length
bne @test_dialect_loop
inc dialect_index+1
jmp @found_preferred_dialect
@end_of_dialects:
lda #$ff
sta dialect_index
@found_preferred_dialect:
ldax #negotiate_protocol_response_message_length
stax tcp_send_data_len
ldax #negotiate_protocol_response_message
jsr tcp_send
rts
start_smb_response:
ldax smb_response_buffer
stax copy_dest
ldy #0
@copy_header_loop:
lda (copy_src),y ; copy_src should be the SMB request - cloning this will set PID / MID etc
sta (copy_dest),y
iny
cpy #smb_response_header_length
bne @copy_header_loop
lda #0
sta smb_response_length+1
lda #smb_response_header_length
sta smb_response_length
ldy #3
sta (copy_dest),y
;set the flags correctly
ldy #smb_response_flags_offset
lda #$82 ;FLAGS byte
sta (copy_dest),y
iny
lda #$01 ;FLAGS2 low byte
sta (copy_dest),y
iny
lda #$00 ;FLAGS2 hi byte
sta (copy_dest),y
rts
add_andx_response:
rts
.import print_a
.import print_hex
session_setup_andx:
lda #'S'
jsr print_a
rts
tree_connect_andx:
lda #'T'
jsr print_a
rts
unknown_andx:
lda andx_opcode
jsr print_hex
lda #'?'
jsr print_a
rts
.rodata
andx_opcodes:
.byte $73
.word session_setup_andx
.byte $75
.word tree_connect_andx
.byte $00
.data
andx_handler:
jmp $FFFF ;filled in later
smb_response_header:
negotiate_protocol_response_message:
.byte $00 ;message type = session message
.byte $00,$00,negotiate_protocol_response_message_length-4 ;NBT header
.byte $FF,"SMB" ;SMB header
.byte $72 ;command = negotiate protocol
.byte $00,$00,$00,$00 ;status = OK
smb_response_flags_offset =*-smb_response_header
.byte $82 ;flags : oplocks not supported, paths are case sensitive
.byte $01,$00 ;flags 2 - long file names allowed
.byte $00, $00 ;PID HIGH
.byte $00,$00,$00,$00,$00,$00,$00,$00 ; signature
.byte $00, $00 ;reserved
negotiate_protocol_response_tid:
.byte $00,$00 ;tree ID
.byte $98,$76 ;PID - to be overwritten
.byte $65,$64 ;USER ID - to be overwritten
.byte $ab,$cd ;multiplex ID - to be overwritten
smb_response_header_length=*-smb_response_header
.byte $11 ;word count
dialect_index: .res 2 ;index of selected dialect
.byte $00 ;security mode: share, no encryption
.byte $01,$00 ;Max MPX count
.byte $01,$00 ;Max VCs count
.byte $00,$08,$00,$00 ;max buffer size
.byte $00,$08,$00,$00 ;max raw size
.byte $12,$34,$56,$78 ;session key
.byte $00,$00,$00,$00 ;capabilities
.byte $00,$00,$00,$00 ;server time low
.byte $00,$00,$00,$00 ;server time high
.byte $00,$00 ;server GMT offset
.byte $00 ;encryption key length
.word negotiate_protocol_response_message_data_length ;data length
negotiate_protocol_response_message_data:
.byte "WORKGROUP",0
.byte "SERVERNAME",0
negotiate_protocol_response_message_length=*-negotiate_protocol_response_message
negotiate_protocol_response_message_data_length=*-negotiate_protocol_response_message_data
host_announce_message:
.byte $11 ;message type = direct group datagram
.byte $02 ;no more fragments, this is first fragment, node type = B
.byte $ab,$cd ;txn id
host_announce_my_ip:
.byte $0,0,0,0 ;source IP
.byte $0,138 ;source port
.byte $00,<(host_announce_message_length-4) ;datagram length
.byte $00,$00 ;packet offset
.byte $20 ;hostname length
host_announce_hostname:
.res 32 ;hostname
.byte $0 ;nul at end of hostname
;now WORKGROUP<1D> encoded
.byte $20, $46, $48, $45, $50, $46, $43, $45, $4c, $45, $48, $46, $43, $45, $50, $46
.byte $46, $46, $41, $43, $41, $43, $41, $43, $41, $43, $41, $43, $41, $43, $41, $42, $4E, $00
.byte $ff,"SMB" ;Server Message Block header
.byte $25 ;SMB command = Transaction
.byte $00 ;error class = success
.byte $00 ;reserved
.byte $00,$00 ;no error
.byte $00 ;flags
.byte $00,$00 ;flags2
.byte $00,$00 ;PID high
.byte $00,$00,$00,$00,$00,$00,$00,$00 ;Signature
.byte $00,$00 ;reserved
.byte $00,$00 ;tree ID
.byte $00,$00 ;process ID
.byte $00,$00 ;user ID
.byte $00,$00 ;multiplex ID
.byte $11 ;txn word count
.byte $00,$00 ;txn paramater count
.byte $21,$00 ;txn total data count
.byte $00,$00 ;txn max paramater count
.byte $00,$00 ;txn max data count
.byte $00 ;txn max setup count
.byte $00 ;reserved
.byte $00,$00 ;flags
.byte $ed,$03,$00,$00 ;timeout = 1 second
.byte $00,$00 ;reserved
.byte $00,$00 ;paramater count
.byte $00,$00 ;paramater offset
.byte $21,$00 ;data count
.byte $56,$00 ;data offset
.byte $03 ;setup count
.byte $00 ;reserved
.byte $01,$00 ;opcode = WRITE MAIL SLOT
.byte $00,$00 ;priority 0
.byte $02,$00 ;class = unreliable & broadcast
.byte $32,$00 ;byte count
.byte "\MAILSLOT\BROWSE", 0
.byte $01 ;command - HOST ANNOUNCEMENT
.byte $0 ;update count 0
.byte $80,$fc,03,00 ;update period
host_announce_servername:
.res 16
.byte $01 ;OS major version
.byte $64 ;OS minor version
.byte $03,$02,$0,$0 ;advertise as a workstation, server & print host
.byte $0F ;browser major version
.byte $01 ;browser minor version
.byte $55,$aa ;signature
.byte $0 ;host comment
host_announce_message_length=*-host_announce_message
netbios_name_query_response:
.byte $12,$34 ;transaction id
.byte $85,$00 ;flags: name query response, no error
.byte $00,$00 ;questions = 0
.byte $00,$01 ;answers = 1
.byte $00,$00 ;authority records = 0
.byte $00,$00 ;additional records = 0
.byte $20 ;
netbios_name_query_response_hostname:
.res 30 ;will be replaced with encoded hostname
.byte $43,$41 ;
.byte $00 ;
.byte $00,$20 ; type = NB
.byte $00,$01 ;class = IN
.byte $00,$00,$01,$40 ; TTL = 64 seconds
.byte $00,$06 ;data length
.byte $00,$00 ;FLAGS = B-NODE, UNIQUE NAME
netbios_name_query_response_ip:
.res 4 ;filled in with our IP
netbios_name_query_response_length=*-netbios_name_query_response
registration_request:
.byte $0c, $64 ;txn ID
.byte $29,$10 ;Registration Request opcode & flags
.byte $00,$01 ;questions = 1
.byte $00,$00 ;answers = 0
.byte $00,$00 ;authority records = 0
.byte $00,$01 ;additional records = 1
registration_request_servername:
;now WORKGROUP<00> encoded
.byte $20, $46, $48, $45, $50, $46, $43, $45, $4c, $45, $48, $46, $43, $45, $50, $46
.byte $46, $46, $41, $43, $41, $43, $41, $43, $41, $43, $41, $43, $41, $43, $41, $41, $41, $00
.byte $00,$20 ;question_type = NB
.byte $00,$01 ;question_class = IN
.byte $c0,$0c ;additional record name : ptr to string in QUESTION NAME
.byte $00,$20 ;question_type = NB
.byte $00,$01 ;question_class = IN
.byte $00,$00,$01,$40 ; TTL = 64 seconds
.byte $00,$06 ;data length
.byte $00,$00 ;FLAGS = B-NODE, UNIQUE NAME
.rodata
preferred_dialect_id: .byte "NT LM 0.12"
preferred_dialect_id_length=*-preferred_dialect_id
positive_session_response_packet:
.byte $82 ;packet type = Positive session response
.byte $00 ;flags
.byte $00, $00 ;message length
positive_session_response_packet_length=*-positive_session_response_packet
.data
cifs_cmd_buffer: .word DEFAULT_CIFS_CMD_BUFFER
smb_response_buffer: .word DEFAULT_SMB_RESPONSE_BUFFER
.bss
hostname_buffer: .res 33
local_hostname: .res 33
raw_local_hostname:
.res 16
hi_nibble: .res 1
connection_closed: .res 1
cifs_cmd_buffer_ptr: .res 2
cifs_cmd_length: .res 2
andx_opcode: .res 1
andx_ptr: .res 2 ;pointer to next 'AndX' command
andx_length: .res 2
smb_ptr: .res 2
smb_response_length: .res 2
; The contents of this file are subject to the Mozilla Public License
; Version 1.1 (the "License"); you may not use this file except in
; compliance with the License. You may obtain a copy of the License at
; http://www.mozilla.org/MPL/
;
; Software distributed under the License is distributed on an "AS IS"
; basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
; License for the specific language governing rights and limitations
; under the License.
;
; The Original Code is ip65.
;
; The Initial Developer of the Original Code is Jonno Downes,
; jonno@jamtronix.com.
; Portions created by the Initial Developer are Copyright (C) 2009
; Jonno Downes. All Rights Reserved.
; -- LICENSE END --