190792Sgshapiro/*
2261363Sgshapiro * Copyright (c) 2000-2001 Proofpoint, Inc. and its suppliers.
390792Sgshapiro *      All rights reserved.
490792Sgshapiro * Copyright (c) 1990, 1993
590792Sgshapiro *	The Regents of the University of California.  All rights reserved.
690792Sgshapiro *
790792Sgshapiro * This code is derived from software contributed to Berkeley by
890792Sgshapiro * Chris Torek.
990792Sgshapiro *
1090792Sgshapiro * By using this file, you agree to the terms and conditions set
1190792Sgshapiro * forth in the LICENSE file which can be found at the top level of
1290792Sgshapiro * the sendmail distribution.
1390792Sgshapiro */
1490792Sgshapiro
1590792Sgshapiro#include <sm/gen.h>
16266692SgshapiroSM_RCSID("@(#)$Id: snprintf.c,v 1.25 2013-11-22 20:51:43 ca Exp $")
1790792Sgshapiro#include <limits.h>
1890792Sgshapiro#include <sm/varargs.h>
1990792Sgshapiro#include <sm/io.h>
20168515Sgshapiro#include <sm/string.h>
2190792Sgshapiro#include "local.h"
2290792Sgshapiro
2390792Sgshapiro/*
2490792Sgshapiro**  SM_SNPRINTF -- format a string to a memory location of restricted size
2590792Sgshapiro**
2690792Sgshapiro**	Parameters:
2790792Sgshapiro**		str -- memory location to place formatted string
2890792Sgshapiro**		n -- size of buffer pointed to by str, capped to
2990792Sgshapiro**			a maximum of INT_MAX
3090792Sgshapiro**		fmt -- the formatting directives
3190792Sgshapiro**		... -- the data to satisfy the formatting
3290792Sgshapiro**
3390792Sgshapiro**	Returns:
3490792Sgshapiro**		Failure: -1
3590792Sgshapiro**		Success: number of bytes that would have been written
3690792Sgshapiro**			to str, not including the trailing '\0',
3790792Sgshapiro**			up to a maximum of INT_MAX, as if there was
3890792Sgshapiro**			no buffer size limitation.  If the result >= n
3990792Sgshapiro**			then the output was truncated.
4090792Sgshapiro**
4190792Sgshapiro**	Side Effects:
4290792Sgshapiro**		If n > 0, then between 0 and n-1 bytes of formatted output
4390792Sgshapiro**		are written into 'str', followed by a '\0'.
4490792Sgshapiro*/
4590792Sgshapiro
4690792Sgshapiroint
4790792Sgshapiro#if SM_VA_STD
4890792Sgshapirosm_snprintf(char *str, size_t n, char const *fmt, ...)
4990792Sgshapiro#else /* SM_VA_STD */
5090792Sgshapirosm_snprintf(str, n, fmt, va_alist)
5190792Sgshapiro	char *str;
5290792Sgshapiro	size_t n;
5390792Sgshapiro	char *fmt;
5490792Sgshapiro	va_dcl
5590792Sgshapiro#endif /* SM_VA_STD */
5690792Sgshapiro{
5790792Sgshapiro	int ret;
5890792Sgshapiro	SM_VA_LOCAL_DECL
5990792Sgshapiro	SM_FILE_T fake;
6090792Sgshapiro
6190792Sgshapiro	/* While snprintf(3) specifies size_t stdio uses an int internally */
6290792Sgshapiro	if (n > INT_MAX)
6390792Sgshapiro		n = INT_MAX;
6490792Sgshapiro	SM_VA_START(ap, fmt);
6590792Sgshapiro
6690792Sgshapiro	/* XXX put this into a static? */
6790792Sgshapiro	fake.sm_magic = SmFileMagic;
6890792Sgshapiro	fake.f_file = -1;
6990792Sgshapiro	fake.f_flags = SMWR | SMSTR;
7090792Sgshapiro	fake.f_cookie = &fake;
7190792Sgshapiro	fake.f_bf.smb_base = fake.f_p = (unsigned char *)str;
7290792Sgshapiro	fake.f_bf.smb_size = fake.f_w = n ? n - 1 : 0;
7390792Sgshapiro	fake.f_timeout = SM_TIME_FOREVER;
7490792Sgshapiro	fake.f_timeoutstate = SM_TIME_BLOCK;
7590792Sgshapiro	fake.f_close = NULL;
7690792Sgshapiro	fake.f_open = NULL;
7790792Sgshapiro	fake.f_read = NULL;
7890792Sgshapiro	fake.f_write = NULL;
7990792Sgshapiro	fake.f_seek = NULL;
8090792Sgshapiro	fake.f_setinfo = fake.f_getinfo = NULL;
8190792Sgshapiro	fake.f_type = "sm_snprintf:fake";
8290792Sgshapiro	ret = sm_io_vfprintf(&fake, SM_TIME_FOREVER, fmt, ap);
8390792Sgshapiro	if (n > 0)
8490792Sgshapiro		*fake.f_p = '\0';
8590792Sgshapiro	SM_VA_END(ap);
8690792Sgshapiro	return ret;
8790792Sgshapiro}
88