1// Licensed to the .NET Foundation under one or more agreements.
2// The .NET Foundation licenses this file to you under the MIT license.
3// See the LICENSE file in the project root for more information.
4
5/***
6*vsprintf.c - print formatted data into a string from var arg list
7*
8
9*
10*Purpose:
11* defines vsprintf(), _vsnprintf() and _vsnprintf_s() - print formatted output to
12* a string, get the data from an argument ptr instead of explicit
13* arguments.
14*
15*******************************************************************************/
16
17#include <string.h>
18#include <errno.h>
19#include <limits.h>
20#include "internal_securecrt.h"
21
22#include "mbusafecrt_internal.h"
23
24typedef int (*OUTPUTFN)(miniFILE *, const char *, va_list);
25
26static int _vsnprintf_helper( OUTPUTFN outfn, char *string, size_t count, const char *format, va_list ap );
27static int _vscprintf_helper ( OUTPUTFN outfn, const char *format, va_list ap);
28
29/***
30*ifndef _COUNT_
31*int vsprintf(string, format, ap) - print formatted data to string from arg ptr
32*else
33*int _vsnprintf(string, cnt, format, ap) - print formatted data to string from arg ptr
34*endif
35*
36*Purpose:
37* Prints formatted data, but to a string and gets data from an argument
38* pointer.
39* Sets up a FILE so file i/o operations can be used, make string look
40* like a huge buffer to it, but _flsbuf will refuse to flush it if it
41* fills up. Appends '\0' to make it a true string.
42*
43* Allocate the 'fake' _iob[] entryit statically instead of on
44* the stack so that other routines can assume that _iob[] entries are in
45* are in DGROUP and, thus, are near.
46*
47*ifdef _COUNT_
48* The _vsnprintf() flavor takes a count argument that is
49* the max number of bytes that should be written to the
50* user's buffer.
51*endif
52*
53* Multi-thread: (1) Since there is no stream, this routine must never try
54* to get the stream lock (i.e., there is no stream lock either). (2)
55* Also, since there is only one staticly allocated 'fake' iob, we must
56* lock/unlock to prevent collisions.
57*
58*Entry:
59* char *string - place to put destination string
60*ifdef _COUNT_
61* size_t count - max number of bytes to put in buffer
62*endif
63* char *format - format string, describes format of data
64* va_list ap - varargs argument pointer
65*
66*Exit:
67* returns number of characters in string
68* returns -2 if the string has been truncated (only in _vsnprintf_helper)
69* returns -1 in other error cases
70*
71*Exceptions:
72*
73*******************************************************************************/
74
75int __cdecl _vsnprintf_helper (
76 OUTPUTFN outfn,
77 char *string,
78 size_t count,
79 const char *format,
80 va_list ap
81 )
82{
83 miniFILE str;
84 miniFILE *outfile = &str;
85 int retval;
86
87 _VALIDATE_RETURN( (format != NULL), EINVAL, -1);
88
89 _VALIDATE_RETURN( (count == 0) || (string != NULL), EINVAL, -1 );
90
91 if(count>INT_MAX)
92 {
93 /* old-style functions allow any large value to mean unbounded */
94 outfile->_cnt = INT_MAX;
95 }
96 else
97 {
98 outfile->_cnt = (int)count;
99 }
100
101 outfile->_flag = _IOWRT|_IOSTRG;
102 outfile->_ptr = outfile->_base = string;
103
104 retval = outfn(outfile, format, ap );
105
106 if ( string==NULL)
107 return(retval);
108
109 if((retval >= 0) && (_putc_nolock('\0',outfile) != EOF))
110 return(retval);
111
112 string[count - 1] = 0;
113
114 if (outfile->_cnt < 0)
115 {
116 /* the buffer was too small; we return -2 to indicate truncation */
117 return -2;
118 }
119 return -1;
120}
121
122int __cdecl vsprintf_s (
123 char *string,
124 size_t sizeInBytes,
125 const char *format,
126 va_list ap
127 )
128{
129 int retvalue = -1;
130
131 /* validation section */
132 _VALIDATE_RETURN(format != NULL, EINVAL, -1);
133 _VALIDATE_RETURN(string != NULL && sizeInBytes > 0, EINVAL, -1);
134
135 retvalue = _vsnprintf_helper(_output_s, string, sizeInBytes, format, ap);
136 if (retvalue < 0)
137 {
138 string[0] = 0;
139 _SECURECRT__FILL_STRING(string, sizeInBytes, 1);
140 }
141 if (retvalue == -2)
142 {
143 _VALIDATE_RETURN(("Buffer too small" && 0), ERANGE, -1);
144 }
145 if (retvalue >= 0)
146 {
147 _SECURECRT__FILL_STRING(string, sizeInBytes, retvalue + 1);
148 }
149
150 return retvalue;
151}
152
153int __cdecl _vsnprintf_s (
154 char *string,
155 size_t sizeInBytes,
156 size_t count,
157 const char *format,
158 va_list ap
159 )
160{
161 int retvalue = -1;
162 errno_t save_errno = 0;
163
164 /* validation section */
165 _VALIDATE_RETURN(format != NULL, EINVAL, -1);
166 if (count == 0 && string == NULL && sizeInBytes == 0)
167 {
168 /* this case is allowed; nothing to do */
169 return 0;
170 }
171 _VALIDATE_RETURN(string != NULL && sizeInBytes > 0, EINVAL, -1);
172
173 if (sizeInBytes > count)
174 {
175 save_errno = errno;
176 retvalue = _vsnprintf_helper(_output_s, string, count + 1, format, ap);
177 if (retvalue == -2)
178 {
179 /* the string has been truncated, return -1 */
180 _SECURECRT__FILL_STRING(string, sizeInBytes, count + 1);
181 if (errno == ERANGE)
182 {
183 errno = save_errno;
184 }
185 return -1;
186 }
187 }
188 else /* sizeInBytes <= count */
189 {
190 save_errno = errno;
191 retvalue = _vsnprintf_helper(_output_s, string, sizeInBytes, format, ap);
192 string[sizeInBytes - 1] = 0;
193 /* we allow truncation if count == _TRUNCATE */
194 if (retvalue == -2 && count == _TRUNCATE)
195 {
196 if (errno == ERANGE)
197 {
198 errno = save_errno;
199 }
200 return -1;
201 }
202 }
203
204 if (retvalue < 0)
205 {
206 string[0] = 0;
207 _SECURECRT__FILL_STRING(string, sizeInBytes, 1);
208 if (retvalue == -2)
209 {
210 _VALIDATE_RETURN(("Buffer too small" && 0), ERANGE, -1);
211 }
212 return -1;
213 }
214
215 _SECURECRT__FILL_STRING(string, sizeInBytes, retvalue + 1);
216
217 return (retvalue < 0 ? -1 : retvalue);
218}
219
220/***
221* _vscprintf() - counts the number of character needed to print the formatted
222* data
223*
224*Purpose:
225* Counts the number of characters in the fotmatted data.
226*
227*Entry:
228* char *format - format string, describes format of data
229* va_list ap - varargs argument pointer
230*
231*Exit:
232* returns number of characters needed to print formatted data.
233*
234*Exceptions:
235*
236*******************************************************************************/
237
238#ifndef _COUNT_
239
240int __cdecl _vscprintf_helper (
241 OUTPUTFN outfn,
242 const char *format,
243 va_list ap
244 )
245{
246 miniFILE str;
247 miniFILE *outfile = &str;
248 int retval;
249
250 _VALIDATE_RETURN( (format != NULL), EINVAL, -1);
251
252 outfile->_cnt = INT_MAX; //MAXSTR;
253 outfile->_flag = _IOWRT|_IOSTRG;
254 outfile->_ptr = outfile->_base = NULL;
255
256 retval = outfn(outfile, format, ap);
257 return(retval);
258}
259
260int __cdecl _vscprintf (
261 const char *format,
262 va_list ap
263 )
264{
265 return _vscprintf_helper(_output, format, ap);
266}
267
268#endif /* _COUNT_ */
269