1/* -*- Mode: C; tab-width: 4 -*-
2 *
3 * Copyright (c) 2008 Apple Inc. All rights reserved.
4 *
5 * Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.
6 * ("Apple") in consideration of your agreement to the following terms, and your
7 * use, installation, modification or redistribution of this Apple software
8 * constitutes acceptance of these terms.  If you do not agree with these terms,
9 * please do not use, install, modify or redistribute this Apple software.
10 *
11 * In consideration of your agreement to abide by the following terms, and subject
12 * to these terms, Apple grants you a personal, non-exclusive license, under Apple's
13 * copyrights in this original Apple software (the "Apple Software"), to use,
14 * reproduce, modify and redistribute the Apple Software, with or without
15 * modifications, in source and/or binary forms; provided that if you redistribute
16 * the Apple Software in its entirety and without modifications, you must retain
17 * this notice and the following text and disclaimers in all such redistributions of
18 * the Apple Software.  Neither the name, trademarks, service marks or logos of
19 * Apple Computer, Inc. may be used to endorse or promote products derived from the
20 * Apple Software without specific prior written permission from Apple.  Except as
21 * expressly stated in this notice, no other rights or licenses, express or implied,
22 * are granted by Apple herein, including but not limited to any patent rights that
23 * may be infringed by your derivative works or by other works in which the Apple
24 * Software may be incorporated.
25 *
26 * The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO
27 * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
28 * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN
30 * COMBINATION WITH YOUR PRODUCTS.
31 *
32 * IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
33 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
34 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION
36 * OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT
37 * (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN
38 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 */
40
41#include <ctype.h>
42#include <stdio.h>			// For stdout, stderr
43
44#include "ClientCommon.h"
45
46const char *GetNextLabel(const char *cstr, char label[64])
47	{
48	char *ptr = label;
49	while (*cstr && *cstr != '.')				// While we have characters in the label...
50		{
51		char c = *cstr++;
52		if (c == '\\' && *cstr)					// If we have a backslash, and it's not the last character of the string
53			{
54			c = *cstr++;
55			if (isdigit(cstr[-1]) && isdigit(cstr[0]) && isdigit(cstr[1]))
56				{
57				int v0 = cstr[-1] - '0';						// then interpret as three-digit decimal
58				int v1 = cstr[ 0] - '0';
59				int v2 = cstr[ 1] - '0';
60				int val = v0 * 100 + v1 * 10 + v2;
61				// If valid three-digit decimal value, use it
62				// Note that although ascii nuls are possible in DNS labels
63				// we're building a C string here so we have no way to represent that
64				if (val == 0) val = '-';
65				if (val <= 255) { c = (char)val; cstr += 2; }
66				}
67			}
68		*ptr++ = c;
69		if (ptr >= label+64) { label[63] = 0; return(NULL); }	// Illegal label more than 63 bytes
70		}
71	*ptr = 0;													// Null-terminate label text
72	if (ptr == label) return(NULL);								// Illegal empty label
73	if (*cstr) cstr++;											// Skip over the trailing dot (if present)
74	return(cstr);
75	}
76