mDNSResponder-212.1.tar.gz

[apple/mdnsresponder.git] / Clients / ClientCommon.c

diff --git a/Clients/ClientCommon.c b/Clients/ClientCommon.c
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+/* -*- Mode: C; tab-width: 4 -*-
+ *
+ * Copyright (c) 2008 Apple Inc. All rights reserved.
+ *
+ * Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.
+ * ("Apple") in consideration of your agreement to the following terms, and your
+ * use, installation, modification or redistribution of this Apple software
+ * constitutes acceptance of these terms.  If you do not agree with these terms,
+ * please do not use, install, modify or redistribute this Apple software.
+ *
+ * In consideration of your agreement to abide by the following terms, and subject
+ * to these terms, Apple grants you a personal, non-exclusive license, under Apple's
+ * copyrights in this original Apple software (the "Apple Software"), to use,
+ * reproduce, modify and redistribute the Apple Software, with or without
+ * modifications, in source and/or binary forms; provided that if you redistribute
+ * the Apple Software in its entirety and without modifications, you must retain
+ * this notice and the following text and disclaimers in all such redistributions of
+ * the Apple Software.  Neither the name, trademarks, service marks or logos of
+ * Apple Computer, Inc. may be used to endorse or promote products derived from the
+ * Apple Software without specific prior written permission from Apple.  Except as
+ * expressly stated in this notice, no other rights or licenses, express or implied,
+ * are granted by Apple herein, including but not limited to any patent rights that
+ * may be infringed by your derivative works or by other works in which the Apple
+ * Software may be incorporated.
+ *
+ * The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO
+ * WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
+ * WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN
+ * COMBINATION WITH YOUR PRODUCTS.
+ *
+ * IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION
+ * OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT
+ * (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+    Change History (most recent first):
+
+$Log: ClientCommon.c,v $
+Revision 1.2  2008/05/08 00:42:03  cheshire
+Removed some unnecessary header files
+
+Revision 1.1  2008/05/08 00:25:48  cheshire
+<rdar://problem/5919272> GetNextLabel insufficiently defensive
+
+
+*/
+
+#include <ctype.h>
+#include <stdio.h>                     // For stdout, stderr
+
+#include "ClientCommon.h"
+
+const char *GetNextLabel(const char *cstr, char label[64])
+       {
+       char *ptr = label;
+       while (*cstr && *cstr != '.')                           // While we have characters in the label...
+               {
+               char c = *cstr++;
+               if (c == '\\' && *cstr)                                 // If we have a backslash, and it's not the last character of the string
+                       {
+                       c = *cstr++;
+                       if (isdigit(cstr[-1]) && isdigit(cstr[0]) && isdigit(cstr[1]))
+                               {
+                               int v0 = cstr[-1] - '0';                                                // then interpret as three-digit decimal
+                               int v1 = cstr[ 0] - '0';
+                               int v2 = cstr[ 1] - '0';
+                               int val = v0 * 100 + v1 * 10 + v2;
+                               // If valid three-digit decimal value, use it
+                               // Note that although ascii nuls are possible in DNS labels
+                               // we're building a C string here so we have no way to represent that
+                               if (val == 0) val = '-';
+                               if (val <= 255) { c = (char)val; cstr += 2; }
+                               }
+                       }
+               *ptr++ = c;
+               if (ptr >= label+64) { label[63] = 0; return(NULL); }   // Illegal label more than 63 bytes
+               }
+       *ptr = 0;                                                                                                       // Null-terminate label text
+       if (ptr == label) return(NULL);                                                         // Illegal empty label
+       if (*cstr) cstr++;                                                                                      // Skip over the trailing dot (if present)
+       return(cstr);
+       }