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 46 const 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