.include "../inc/common.i" .export parse_dotted_quad .export dotted_quad_value .bss dotted_quad_value: .res 4 ; set to 32 bit ip address on a succesful call to parse_dotted_quad .data ; self modifying code dotted_quad_ptr: lda $FFFF rts .code ; convert a string representing a dotted quad (IP address, netmask) into 4 octets ; inputs: ; AX= pointer to null-terminated (*) string containing dotted quad ; e.g. "192.168.1.0",0 ; outputs: ; carry flag is set if there was an error, clear otherwise ; dotted_quad_value: will be set to (32 bit) ip address (if no error) ; (*) NB to assist with url parsing, a ':' or '/' can also terminate the string parse_dotted_quad: stax dotted_quad_ptr+1 ldx #0 txa sta dotted_quad_value @each_byte: jsr get_next_byte cmp #0 beq @done and #$7F ; turn off bit 7 cmp #'.' beq @got_dot cmp #':' beq @done cmp #'/' beq @done sec sbc #'0' bcc @error cmp #10 bcs @error clc ldy #10 @mul_by_y: adc dotted_quad_value,x bcs @error dey bne @mul_by_y sta dotted_quad_value,x jmp @each_byte @got_dot: inx cpx #4 beq @error lda #0 sta dotted_quad_value,x jmp @each_byte @done: cpx #3 bne @error clc rts @error: sec rts get_next_byte: jsr dotted_quad_ptr inc dotted_quad_ptr+1 bne :+ inc dotted_quad_ptr+2 : rts ; -- LICENSE FOR dottedquad.s -- ; 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 --