safec  2.1
Safe C Library - ISO TR24731 Bounds Checking Interface
strfirstsame_s.c
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1 /*------------------------------------------------------------------
2  * strfirstsame_s.c
3  *
4  * November 2008, Bo Berry
5  *
6  * Copyright (c) 2008-2011 by Cisco Systems, Inc
7  * All rights reserved.
8  *
9  * Permission is hereby granted, free of charge, to any person
10  * obtaining a copy of this software and associated documentation
11  * files (the "Software"), to deal in the Software without
12  * restriction, including without limitation the rights to use,
13  * copy, modify, merge, publish, distribute, sublicense, and/or
14  * sell copies of the Software, and to permit persons to whom the
15  * Software is furnished to do so, subject to the following
16  * conditions:
17  *
18  * The above copyright notice and this permission notice shall be
19  * included in all copies or substantial portions of the Software.
20  *
21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
22  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
23  * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
24  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
25  * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
26  * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28  * OTHER DEALINGS IN THE SOFTWARE.
29  *------------------------------------------------------------------
30  */
31 
32 #include "safeclib_private.h"
33 #include "safe_str_constraint.h"
34 #include "safe_str_lib.h"
35 
36 
70 errno_t
71 strfirstsame_s (const char *dest, rsize_t dmax,
72  const char *src, rsize_t *index)
73 {
74  const char *rp = 0;
75 
76  if (index == NULL) {
77  invoke_safe_str_constraint_handler("strfirstsame_s: index is null",
78  NULL, ESNULLP);
79  return (ESNULLP);
80  }
81  *index = 0;
82 
83  if (dest == NULL) {
84  invoke_safe_str_constraint_handler("strfirstsame_s: dest is null",
85  NULL, ESNULLP);
86  return (ESNULLP);
87  }
88 
89  if (src == NULL) {
90  invoke_safe_str_constraint_handler("strfirstsame_s: src is null",
91  NULL, ESNULLP);
92  return (ESNULLP);
93  }
94 
95  if (dmax == 0 ) {
96  invoke_safe_str_constraint_handler("strfirstsame_s: dmax is 0",
97  NULL, ESZEROL);
98  return (ESZEROL);
99  }
100 
101  if (dmax > RSIZE_MAX_STR) {
102  invoke_safe_str_constraint_handler("strfirstsame_s: dmax exceeds max",
103  NULL, ESLEMAX);
104  return (ESLEMAX);
105  }
106 
107  /* hold reference point */
108  rp = dest;
109 
110  /*
111  * find the offset
112  */
113  while (*dest && *src && dmax) {
114 
115  if (*dest == *src) {
116  *index = (uint32_t)(dest - rp);
117  return (EOK);
118  }
119 
120  dest++;
121  src++;
122  dmax--;
123  }
124 
125  return (ESNOTFND);
126 }
errno_t strfirstsame_s(const char *dest, rsize_t dmax, const char *src, rsize_t *index)
Returns the index of the first character that is the same between dest and src.
void invoke_safe_str_constraint_handler(const char *msg, void *ptr, errno_t error)
Invokes the currently set constraint handler or the default.