safec  2.1
Safe C Library - ISO TR24731 Bounds Checking Interface
strcpyfldout_s.c
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1 /*------------------------------------------------------------------
2  * strcpyfldout_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 
78 errno_t
79 strcpyfldout_s (char *dest, rsize_t dmax, const char *src, rsize_t slen)
80 {
81  rsize_t orig_dmax;
82  char *orig_dest;
83  const char *overlap_bumper;
84 
85  if (dest == NULL) {
86  invoke_safe_str_constraint_handler("strcpyfldout_s: dest is null",
87  NULL, ESNULLP);
88  return (ESNULLP);
89  }
90 
91  if (dmax == 0) {
92  invoke_safe_str_constraint_handler("strcpyfldout_s: dmax is 0",
93  NULL, ESZEROL);
94  return (ESZEROL);
95  }
96 
97  if (dmax > RSIZE_MAX_STR) {
98  invoke_safe_str_constraint_handler("strcpyfldout_s: dmax exceeds max",
99  NULL, ESLEMAX);
100  return (ESLEMAX);
101  }
102 
103  if (src == NULL) {
104  /* null string to clear data */
105  while (dmax) { *dest = '\0'; dmax--; dest++; }
106 
107  invoke_safe_str_constraint_handler("strcpyfldout_s: src is null",
108  NULL, ESNULLP);
109  return (ESNULLP);
110  }
111 
112  if (slen == 0) {
113  /* null string to clear data */
114  while (dmax) { *dest = '\0'; dmax--; dest++; }
115 
116  invoke_safe_str_constraint_handler("strcpyfldout_s: slen is 0",
117  NULL, ESZEROL);
118  return (ESZEROL);
119  }
120 
121  if (slen > dmax) {
122  /* null string to clear data */
123  while (dmax) { *dest = '\0'; dmax--; dest++; }
124 
125  invoke_safe_str_constraint_handler("strcpyfldout_s: slen exceeds max",
126  NULL, ESNOSPC);
127  return (ESNOSPC);
128  }
129 
130 
131  /* hold base of dest in case src was not copied */
132  orig_dmax = dmax;
133  orig_dest = dest;
134 
135  if (dest < src) {
136  overlap_bumper = src;
137 
138  while (dmax > 1 && slen) {
139 
140  if (dest == overlap_bumper) {
141  dmax = orig_dmax;
142  dest = orig_dest;
143 
144  /* null string to eliminate partial copy */
145  while (dmax) { *dest = '\0'; dmax--; dest++; }
146 
148  "strcpyfldout_s: overlapping objects",
149  NULL, ESOVRLP);
150  return (ESOVRLP);
151  }
152 
153  dmax--;
154  slen--;
155  *dest++ = *src++;
156  }
157 
158  } else {
159  overlap_bumper = dest;
160 
161  while (dmax > 1 && slen) {
162 
163  if (src == overlap_bumper) {
164  dmax = orig_dmax;
165  dest = orig_dest;
166 
167  /* null string to eliminate partial copy */
168  while (dmax) { *dest = '\0'; dmax--; dest++; }
169 
171  "strcpyfldout_s: overlapping objects",
172  NULL, ESOVRLP);
173  return (ESOVRLP);
174  }
175 
176  dmax--;
177  slen--;
178  *dest++ = *src++;
179  }
180  }
181 
182  /* null slack space */
183  while (dmax) { *dest = '\0'; dmax--; dest++; }
184 
185  return (EOK);
186 }
void invoke_safe_str_constraint_handler(const char *msg, void *ptr, errno_t error)
Invokes the currently set constraint handler or the default.
errno_t strcpyfldout_s(char *dest, rsize_t dmax, const char *src, rsize_t slen)
The strcpyfldout_s function copies slen characters from the character array pointed to by src into th...