safec  2.1
Safe C Library - ISO TR24731 Bounds Checking Interface
strcasestr_s.c
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1 /*------------------------------------------------------------------
2  * strcasestr_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 
69 errno_t
70 strcasestr_s (char *dest, rsize_t dmax,
71  const char *src, rsize_t slen, char **substring)
72 {
73  rsize_t len;
74  rsize_t dlen;
75  int i;
76 
77  if (substring == NULL) {
78  invoke_safe_str_constraint_handler("strcasestr_s: substring is null",
79  NULL, ESNULLP);
80  return (ESNULLP);
81  }
82  *substring = NULL;
83 
84  if (dest == NULL) {
85  invoke_safe_str_constraint_handler("strcasestr_s: dest is null",
86  NULL, ESNULLP);
87  return (ESNULLP);
88  }
89 
90  if (dmax == 0) {
91  invoke_safe_str_constraint_handler("strcasestr_s: dmax is 0",
92  NULL, ESZEROL);
93  return (ESZEROL);
94  }
95 
96  if (dmax > RSIZE_MAX_STR) {
97  invoke_safe_str_constraint_handler("strcasestr_s: dmax exceeds max",
98  NULL, ESLEMAX);
99  return (ESLEMAX);
100  }
101 
102  if (src == NULL) {
103  invoke_safe_str_constraint_handler("strcasestr_s: src is null",
104  NULL, ESNULLP);
105  return (ESNULLP);
106  }
107 
108  if (slen == 0) {
109  invoke_safe_str_constraint_handler("strcasestr_s: slen is 0",
110  NULL, ESZEROL);
111  return (ESZEROL);
112  }
113 
114  if (slen > RSIZE_MAX_STR) {
115  invoke_safe_str_constraint_handler("strcasestr_s: slen exceeds max",
116  NULL, ESLEMAX);
117  return (ESLEMAX);
118  }
119 
120  /*
121  * src points to a string with zero length, or
122  * src equals dest, return dest
123  */
124  if (*src == '\0' || dest == src) {
125  *substring = dest;
126  return (EOK);
127  }
128 
129  while (*dest && dmax) {
130  i = 0;
131  len = slen;
132  dlen = dmax;
133 
134  while (dest[i] && dlen) {
135 
136  /* not a match, not a substring */
137  if (toupper(dest[i]) != toupper(src[i])) {
138  break;
139  }
140 
141  /* move to the next char */
142  i++;
143  len--;
144  dlen--;
145 
146  if (src[i] == '\0' || !len) {
147  *substring = dest;
148  return (EOK);
149  }
150  }
151  dest++;
152  dmax--;
153  }
154 
155  /*
156  * substring was not found, return NULL
157  */
158  *substring = NULL;
159  return (ESNOTFND);
160 }
errno_t strcasestr_s(char *dest, rsize_t dmax, const char *src, rsize_t slen, char **substring)
The strcasestr_s() function locates the first occurrence of the substring pointed to by src which wou...
Definition: strcasestr_s.c:70
void invoke_safe_str_constraint_handler(const char *msg, void *ptr, errno_t error)
Invokes the currently set constraint handler or the default.