xnu-6153.141.1.tar.gz

[apple/xnu.git] / libsyscall / mach / mig_strncpy.c

diff --git a/libsyscall/mach/mig_strncpy.c b/libsyscall/mach/mig_strncpy.c
index 4366563fa9b545c86fdf92f24dc828ef5f72ee06..731340426e575d9c5773dc355b1e58d27c18f67a 100644 (file)
--- a/libsyscall/mach/mig_strncpy.c
+++ b/libsyscall/mach/mig_strncpy.c
@@ -1,8 +1,8 @@
 /*
- * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 1999-2010 Apple Inc. All rights reserved.
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- * 
+ *
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
@@ -11,10 +11,10 @@
  * unlawful or unlicensed copies of an Apple operating system, or to
  * circumvent, violate, or enable the circumvention or violation of, any
  * terms of an Apple operating system software license agreement.
- * 
+ *
  * Please obtain a copy of the License at
  * http://www.opensource.apple.com/apsl/ and read it before using this file.
- * 
+ *
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
@@ -22,31 +22,31 @@
  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  * Please see the License for the specific language governing rights and
  * limitations under the License.
- * 
+ *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
-/* 
+/*
  * Mach Operating System
  * Copyright (c) 1991,1990,1989 Carnegie Mellon University
  * All Rights Reserved.
- * 
+ *
  * Permission to use, copy, modify and distribute this software and its
  * documentation is hereby granted, provided that both the copyright
  * notice and this permission notice appear in all copies of the
  * software, derivative works or modified versions, and any portions
  * thereof, and that both notices appear in supporting documentation.
- * 
+ *
  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
- * 
+ *
  * Carnegie Mellon requests users of this software to return to
- * 
+ *
  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  *  School of Computer Science
  *  Carnegie Mellon University
  *  Pittsburgh PA 15213-3890
- * 
+ *
  * any improvements or extensions that they make and grant Carnegie Mellon
  * the rights to redistribute these changes.
  */
@@ -54,16 +54,16 @@
  * mig_strncpy.c - by Joshua Block
  *
  * mig_strncpy -- Bounded string copy.  Does what the library routine strncpy
- * OUGHT to do:  Copies the (null terminated) string in src into dest, a 
+ * OUGHT to do:  Copies the (null terminated) string in src into dest, a
  * buffer of length len.  Assures that the copy is still null terminated
  * and doesn't overflow the buffer, truncating the copy if necessary.
  *
  * Parameters:
- * 
+ *
  *     dest - Pointer to destination buffer.
- * 
+ *
  *     src - Pointer to source string.
- * 
+ *
  *     len - Length of destination buffer.
  *
  * Result:
@@ -73,19 +73,78 @@
 
 int
 mig_strncpy(
-    register char *dest,
-    register const char *src,
-    register int len)
+       char *dest,
+       const char *src,
+       int len)
 {
-    register int i;
+       int i;
+
+       if (len <= 0) {
+               return 0;
+       }
+
+       for (i = 1; i < len; i++) {
+               if (!(*dest++ = *src++)) {
+                       return i;
+               }
+       }
+
+       *dest = '\0';
+       return i;
+}
+
+/*
+ * mig_strncpy_zerofill -- Bounded string copy.  Does what the
+ * library routine strncpy OUGHT to do:  Copies the (null terminated)
+ * string in src into dest, a buffer of length len.  Assures that
+ * the copy is still null terminated and doesn't overflow the buffer,
+ * truncating the copy if necessary. If the string in src is smaller
+ * than given length len, it will zero fill the remaining bytes in dest.
+ *
+ * Parameters:
+ *
+ *     dest - Pointer to destination buffer.
+ *
+ *     src - Pointer to source string.
+ *
+ *     len - Length of destination buffer.
+ *
+ * Result:
+ *     length of string copied, INCLUDING the trailing 0.
+ */
+int
+mig_strncpy_zerofill(
+       char *dest,
+       const char *src,
+       int len)
+{
+       int i;
+       boolean_t terminated = FALSE;
+       int retval = 0;
+
+       if (len <= 0 || dest == 0) {
+               return 0;
+       }
+
+       if (src == 0) {
+               terminated = TRUE;
+       }
 
-    if (len <= 0)
-       return 0;
+       for (i = 1; i < len; i++) {
+               if (!terminated) {
+                       if (!(*dest++ = *src++)) {
+                               retval = i;
+                               terminated = TRUE;
+                       }
+               } else {
+                       *dest++ = '\0';
+               }
+       }
 
-    for (i=1; i<len; i++)
-       if (! (*dest++ = *src++))
-           return i;
+       *dest = '\0';
+       if (!terminated) {
+               retval = i;
+       }
 
-    *dest = '\0';
-    return i;
+       return retval;
 }