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- //
- // Copyright (c) Microsoft. All rights reserved.
- // Licensed under the MIT license. See LICENSE file in the project root for full license information.
- //
- /***
- *vsprintf.c - print formatted data into a string from var arg list
- *
- *
- *Purpose:
- * defines vsprintf(), _vsnprintf() and _vsnprintf_s() - print formatted output to
- * a string, get the data from an argument ptr instead of explicit
- * arguments.
- *
- *******************************************************************************/
- #include <string.h>
- #include <errno.h>
- #include <limits.h>
- #include "internal_securecrt.h"
- #include "mbusafecrt_internal.h"
- typedef int (*OUTPUTFN)(miniFILE *, const char *, va_list);
- static int _vsnprintf_helper( OUTPUTFN outfn, char *string, size_t count, const char *format, va_list ap );
- /***
- *ifndef _COUNT_
- *int vsprintf(string, format, ap) - print formatted data to string from arg ptr
- *else
- *int _vsnprintf(string, cnt, format, ap) - print formatted data to string from arg ptr
- *endif
- *
- *Purpose:
- * Prints formatted data, but to a string and gets data from an argument
- * pointer.
- * Sets up a FILE so file i/o operations can be used, make string look
- * like a huge buffer to it, but _flsbuf will refuse to flush it if it
- * fills up. Appends '\0' to make it a true string.
- *
- * Allocate the 'fake' _iob[] entryit statically instead of on
- * the stack so that other routines can assume that _iob[] entries are in
- * are in DGROUP and, thus, are near.
- *
- *ifdef _COUNT_
- * The _vsnprintf() flavor takes a count argument that is
- * the max number of bytes that should be written to the
- * user's buffer.
- *endif
- *
- * Multi-thread: (1) Since there is no stream, this routine must never try
- * to get the stream lock (i.e., there is no stream lock either). (2)
- * Also, since there is only one staticly allocated 'fake' iob, we must
- * lock/unlock to prevent collisions.
- *
- *Entry:
- * char *string - place to put destination string
- *ifdef _COUNT_
- * size_t count - max number of bytes to put in buffer
- *endif
- * char *format - format string, describes format of data
- * va_list ap - varargs argument pointer
- *
- *Exit:
- * returns number of characters in string
- * returns -2 if the string has been truncated (only in _vsnprintf_helper)
- * returns -1 in other error cases
- *
- *Exceptions:
- *
- *******************************************************************************/
- int __cdecl _vsnprintf_helper (
- OUTPUTFN outfn,
- char *string,
- size_t count,
- const char *format,
- va_list ap
- )
- {
- miniFILE str;
- miniFILE *outfile = &str;
- int retval;
- _VALIDATE_RETURN( (format != NULL), EINVAL, -1);
- _VALIDATE_RETURN( (count == 0) || (string != NULL), EINVAL, -1 );
- if(count>INT_MAX)
- {
- /* old-style functions allow any large value to mean unbounded */
- outfile->_cnt = INT_MAX;
- }
- else
- {
- outfile->_cnt = (int)count;
- }
- outfile->_flag = _IOWRT|_IOSTRG;
- outfile->_ptr = outfile->_base = string;
- retval = outfn(outfile, format, ap );
- if ( string==NULL)
- return(retval);
- if((retval >= 0) && (_putc_nolock('\0',outfile) != EOF))
- return(retval);
- string[count - 1] = 0;
- if (outfile->_cnt < 0)
- {
- /* the buffer was too small; we return -2 to indicate truncation */
- return -2;
- }
- return -1;
- }
- int __cdecl _vsprintf_s (
- char *string,
- size_t sizeInBytes,
- const char *format,
- va_list ap
- )
- {
- int retvalue = -1;
- /* validation section */
- _VALIDATE_RETURN(format != NULL, EINVAL, -1);
- _VALIDATE_RETURN(string != NULL && sizeInBytes > 0, EINVAL, -1);
- retvalue = _vsnprintf_helper(_output_s, string, sizeInBytes, format, ap);
- if (retvalue < 0)
- {
- string[0] = 0;
- _SECURECRT__FILL_STRING(string, sizeInBytes, 1);
- }
- if (retvalue == -2)
- {
- _VALIDATE_RETURN(("Buffer too small" && 0), ERANGE, -1);
- }
- if (retvalue >= 0)
- {
- _SECURECRT__FILL_STRING(string, sizeInBytes, retvalue + 1);
- }
- return retvalue;
- }
- int __cdecl vsprintf_s(char *_Dst, size_t _SizeInBytes, const char *_Format, va_list _ArgList)
- {
- return _vsprintf_s(_Dst, _SizeInBytes, _Format, _ArgList);
- }
- int __cdecl _vsnprintf_s (
- char *string,
- size_t sizeInBytes,
- size_t count,
- const char *format,
- va_list ap
- )
- {
- int retvalue = -1;
- errno_t save_errno = 0;
- /* validation section */
- _VALIDATE_RETURN(format != NULL, EINVAL, -1);
- if (count == 0 && string == NULL && sizeInBytes == 0)
- {
- /* this case is allowed; nothing to do */
- return 0;
- }
- _VALIDATE_RETURN(string != NULL && sizeInBytes > 0, EINVAL, -1);
- if (sizeInBytes > count)
- {
- save_errno = errno;
- retvalue = _vsnprintf_helper(_output_s, string, count + 1, format, ap);
- if (retvalue == -2)
- {
- /* the string has been truncated, return -1 */
- _SECURECRT__FILL_STRING(string, sizeInBytes, count + 1);
- if (errno == ERANGE)
- {
- errno = save_errno;
- }
- return -1;
- }
- }
- else /* sizeInBytes <= count */
- {
- save_errno = errno;
- retvalue = _vsnprintf_helper(_output_s, string, sizeInBytes, format, ap);
- string[sizeInBytes - 1] = 0;
- /* we allow truncation if count == _TRUNCATE */
- if (retvalue == -2 && count == _TRUNCATE)
- {
- if (errno == ERANGE)
- {
- errno = save_errno;
- }
- return -1;
- }
- }
- if (retvalue < 0)
- {
- string[0] = 0;
- _SECURECRT__FILL_STRING(string, sizeInBytes, 1);
- if (retvalue == -2)
- {
- _VALIDATE_RETURN(("Buffer too small" && 0), ERANGE, -1);
- }
- return -1;
- }
- _SECURECRT__FILL_STRING(string, sizeInBytes, retvalue + 1);
- return (retvalue < 0 ? -1 : retvalue);
- }
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