xref: /freebsd/crypto/openssh/openbsd-compat/bsd-snprintf.c (revision 5e8dbd04ef7b2df5ba3f8dc859ad6e472ce1c534)

/*
 * Copyright Patrick Powell 1995
 * This code is based on code written by Patrick Powell (papowell@astart.com)
 * It may be used for any purpose as long as this notice remains intact
 * on all source code distributions
 */

/**************************************************************
 * Original:
 * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
 * A bombproof version of doprnt (dopr) included.
 * Sigh.  This sort of thing is always nasty do deal with.  Note that
 * the version here does not include floating point...
 *
 * snprintf() is used instead of sprintf() as it does limit checks
 * for string length.  This covers a nasty loophole.
 *
 * The other functions are there to prevent NULL pointers from
 * causing nast effects.
 *
 * More Recently:
 *  Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
 *  This was ugly.  It is still ugly.  I opted out of floating point
 *  numbers, but the formatter understands just about everything
 *  from the normal C string format, at least as far as I can tell from
 *  the Solaris 2.5 printf(3S) man page.
 *
 *  Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
 *    Ok, added some minimal floating point support, which means this
 *    probably requires libm on most operating systems.  Don't yet
 *    support the exponent (e,E) and sigfig (g,G).  Also, fmtint()
 *    was pretty badly broken, it just wasn't being exercised in ways
 *    which showed it, so that's been fixed.  Also, formated the code
 *    to mutt conventions, and removed dead code left over from the
 *    original.  Also, there is now a builtin-test, just compile with:
 *           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
 *    and run snprintf for results.
 *
 *  Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
 *    The PGP code was using unsigned hexadecimal formats.
 *    Unfortunately, unsigned formats simply didn't work.
 *
 *  Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
 *    The original code assumed that both snprintf() and vsnprintf() were
 *    missing.  Some systems only have snprintf() but not vsnprintf(), so
 *    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
 *
 *  Ben Lindstrom <mouring@eviladmin.org> 09/27/00 for OpenSSH
 *    Welcome to the world of %lld and %qd support.  With other
 *    long long support.  This is needed for sftp-server to work
 *    right.
 *
 *  Ben Lindstrom <mouring@eviladmin.org> 02/12/01 for OpenSSH
 *    Removed all hint of VARARGS stuff and banished it to the void,
 *    and did a bit of KNF style work to make things a bit more
 *    acceptable.  Consider stealing from mutt or enlightenment.
 **************************************************************/

#include "includes.h"

RCSID("$Id: bsd-snprintf.c,v 1.9 2004/09/23 11:35:09 dtucker Exp $");

#if defined(BROKEN_SNPRINTF)		/* For those with broken snprintf() */
# undef HAVE_SNPRINTF
# undef HAVE_VSNPRINTF
#endif

#if !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF)

static void
dopr(char *buffer, size_t maxlen, const char *format, va_list args);

static void
fmtstr(char *buffer, size_t *currlen, size_t maxlen, char *value, int flags,
    int min, int max);

static void
fmtint(char *buffer, size_t *currlen, size_t maxlen, long value, int base,
    int min, int max, int flags);

static void
fmtfp(char *buffer, size_t *currlen, size_t maxlen, long double fvalue,
    int min, int max, int flags);

static void
dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c);

/*
 * dopr(): poor man's version of doprintf
 */

/* format read states */
#define DP_S_DEFAULT 0
#define DP_S_FLAGS   1
#define DP_S_MIN     2
#define DP_S_DOT     3
#define DP_S_MAX     4
#define DP_S_MOD     5
#define DP_S_CONV    6
#define DP_S_DONE    7

/* format flags - Bits */
#define DP_F_MINUS 	(1 << 0)
#define DP_F_PLUS  	(1 << 1)
#define DP_F_SPACE 	(1 << 2)
#define DP_F_NUM   	(1 << 3)
#define DP_F_ZERO  	(1 << 4)
#define DP_F_UP    	(1 << 5)
#define DP_F_UNSIGNED 	(1 << 6)

/* Conversion Flags */
#define DP_C_SHORT     1
#define DP_C_LONG      2
#define DP_C_LDOUBLE   3
#define DP_C_LONG_LONG 4

#define char_to_int(p) (p - '0')
#define abs_val(p) (p < 0 ? -p : p)


static void
dopr(char *buffer, size_t maxlen, const char *format, va_list args)
{
	char *strvalue, ch;
	long value;
	long double fvalue;
	int min = 0, max = -1, state = DP_S_DEFAULT, flags = 0, cflags = 0;
	size_t currlen = 0;

	ch = *format++;

	while (state != DP_S_DONE) {
		if ((ch == '\0') || (currlen >= maxlen))
			state = DP_S_DONE;

		switch(state) {
		case DP_S_DEFAULT:
			if (ch == '%')
				state = DP_S_FLAGS;
			else
				dopr_outch(buffer, &currlen, maxlen, ch);
			ch = *format++;
			break;
		case DP_S_FLAGS:
			switch (ch) {
			case '-':
				flags |= DP_F_MINUS;
				ch = *format++;
				break;
			case '+':
				flags |= DP_F_PLUS;
				ch = *format++;
				break;
			case ' ':
				flags |= DP_F_SPACE;
				ch = *format++;
				break;
			case '#':
				flags |= DP_F_NUM;
				ch = *format++;
				break;
			case '0':
				flags |= DP_F_ZERO;
				ch = *format++;
				break;
			default:
				state = DP_S_MIN;
				break;
			}
			break;
		case DP_S_MIN:
			if (isdigit((unsigned char)ch)) {
				min = 10 * min + char_to_int (ch);
				ch = *format++;
			} else if (ch == '*') {
				min = va_arg (args, int);
				ch = *format++;
				state = DP_S_DOT;
			} else
				state = DP_S_DOT;
			break;
		case DP_S_DOT:
			if (ch == '.') {
				state = DP_S_MAX;
				ch = *format++;
			} else
				state = DP_S_MOD;
			break;
		case DP_S_MAX:
			if (isdigit((unsigned char)ch)) {
				if (max < 0)
					max = 0;
				max = 10 * max + char_to_int(ch);
				ch = *format++;
			} else if (ch == '*') {
				max = va_arg (args, int);
				ch = *format++;
				state = DP_S_MOD;
			} else
				state = DP_S_MOD;
			break;
		case DP_S_MOD:
			switch (ch) {
			case 'h':
				cflags = DP_C_SHORT;
				ch = *format++;
				break;
			case 'l':
				cflags = DP_C_LONG;
				ch = *format++;
				if (ch == 'l') {
					cflags = DP_C_LONG_LONG;
					ch = *format++;
				}
				break;
			case 'q':
				cflags = DP_C_LONG_LONG;
				ch = *format++;
				break;
			case 'L':
				cflags = DP_C_LDOUBLE;
				ch = *format++;
				break;
			default:
				break;
			}
			state = DP_S_CONV;
			break;
		case DP_S_CONV:
			switch (ch) {
			case 'd':
			case 'i':
				if (cflags == DP_C_SHORT)
					value = va_arg(args, int);
				else if (cflags == DP_C_LONG)
					value = va_arg(args, long int);
				else if (cflags == DP_C_LONG_LONG)
					value = va_arg (args, long long);
				else
					value = va_arg (args, int);
				fmtint(buffer, &currlen, maxlen, value, 10, min, max, flags);
				break;
			case 'o':
				flags |= DP_F_UNSIGNED;
				if (cflags == DP_C_SHORT)
					value = va_arg(args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = va_arg(args, unsigned long int);
				else if (cflags == DP_C_LONG_LONG)
					value = va_arg(args, unsigned long long);
				else
					value = va_arg(args, unsigned int);
				fmtint(buffer, &currlen, maxlen, value, 8, min, max, flags);
				break;
			case 'u':
				flags |= DP_F_UNSIGNED;
				if (cflags == DP_C_SHORT)
					value = va_arg(args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = va_arg(args, unsigned long int);
				else if (cflags == DP_C_LONG_LONG)
					value = va_arg(args, unsigned long long);
				else
					value = va_arg(args, unsigned int);
				fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
				break;
			case 'X':
				flags |= DP_F_UP;
			case 'x':
				flags |= DP_F_UNSIGNED;
				if (cflags == DP_C_SHORT)
					value = va_arg(args, unsigned int);
				else if (cflags == DP_C_LONG)
					value = va_arg(args, unsigned long int);
				else if (cflags == DP_C_LONG_LONG)
					value = va_arg(args, unsigned long long);
				else
					value = va_arg(args, unsigned int);
				fmtint(buffer, &currlen, maxlen, value, 16, min, max, flags);
				break;
			case 'f':
				if (cflags == DP_C_LDOUBLE)
					fvalue = va_arg(args, long double);
				else
					fvalue = va_arg(args, double);
				/* um, floating point? */
				fmtfp(buffer, &currlen, maxlen, fvalue, min, max, flags);
				break;
			case 'E':
				flags |= DP_F_UP;
			case 'e':
				if (cflags == DP_C_LDOUBLE)
					fvalue = va_arg(args, long double);
				else
					fvalue = va_arg(args, double);
				break;
			case 'G':
				flags |= DP_F_UP;
			case 'g':
				if (cflags == DP_C_LDOUBLE)
					fvalue = va_arg(args, long double);
				else
					fvalue = va_arg(args, double);
				break;
			case 'c':
				dopr_outch(buffer, &currlen, maxlen, va_arg(args, int));
				break;
			case 's':
				strvalue = va_arg(args, char *);
				if (max < 0)
					max = maxlen; /* ie, no max */
				fmtstr(buffer, &currlen, maxlen, strvalue, flags, min, max);
				break;
			case 'p':
				strvalue = va_arg(args, void *);
				fmtint(buffer, &currlen, maxlen, (long) strvalue, 16, min, max, flags);
				break;
			case 'n':
				if (cflags == DP_C_SHORT) {
					short int *num;
					num = va_arg(args, short int *);
					*num = currlen;
				} else if (cflags == DP_C_LONG) {
					long int *num;
					num = va_arg(args, long int *);
					*num = currlen;
				} else if (cflags == DP_C_LONG_LONG) {
					long long *num;
					num = va_arg(args, long long *);
					*num = currlen;
				} else {
					int *num;
					num = va_arg(args, int *);
					*num = currlen;
				}
				break;
			case '%':
				dopr_outch(buffer, &currlen, maxlen, ch);
				break;
			case 'w': /* not supported yet, treat as next char */
				ch = *format++;
				break;
			default: /* Unknown, skip */
			break;
			}
			ch = *format++;
			state = DP_S_DEFAULT;
			flags = cflags = min = 0;
			max = -1;
			break;
		case DP_S_DONE:
			break;
		default: /* hmm? */
			break; /* some picky compilers need this */
		}
	}
	if (currlen < maxlen - 1)
		buffer[currlen] = '\0';
	else
		buffer[maxlen - 1] = '\0';
}

static void
fmtstr(char *buffer, size_t *currlen, size_t maxlen,
    char *value, int flags, int min, int max)
{
	int cnt = 0, padlen, strln;     /* amount to pad */

	if (value == 0)
		value = "<NULL>";

	for (strln = 0; strln < max && value[strln]; ++strln); /* strlen */
	padlen = min - strln;
	if (padlen < 0)
		padlen = 0;
	if (flags & DP_F_MINUS)
		padlen = -padlen; /* Left Justify */

	while ((padlen > 0) && (cnt < max)) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		--padlen;
		++cnt;
	}
	while (*value && (cnt < max)) {
		dopr_outch(buffer, currlen, maxlen, *value++);
		++cnt;
	}
	while ((padlen < 0) && (cnt < max)) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		++padlen;
		++cnt;
	}
}

/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */

static void
fmtint(char *buffer, size_t *currlen, size_t maxlen,
    long value, int base, int min, int max, int flags)
{
	unsigned long uvalue;
	char convert[20];
	int signvalue = 0, place = 0, caps = 0;
	int spadlen = 0; /* amount to space pad */
	int zpadlen = 0; /* amount to zero pad */

	if (max < 0)
		max = 0;

	uvalue = value;

	if (!(flags & DP_F_UNSIGNED)) {
		if (value < 0) {
			signvalue = '-';
			uvalue = -value;
		} else if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
			signvalue = '+';
		else if (flags & DP_F_SPACE)
			signvalue = ' ';
	}

	if (flags & DP_F_UP)
		caps = 1; /* Should characters be upper case? */
	do {
		convert[place++] =
		    (caps ? "0123456789ABCDEF" : "0123456789abcdef")
		    [uvalue % (unsigned)base];
		uvalue = (uvalue / (unsigned)base );
	} while (uvalue && (place < 20));
	if (place == 20)
		place--;
	convert[place] = 0;

	zpadlen = max - place;
	spadlen = min - MAX (max, place) - (signvalue ? 1 : 0);
	if (zpadlen < 0)
		zpadlen = 0;
	if (spadlen < 0)
		spadlen = 0;
	if (flags & DP_F_ZERO) {
		zpadlen = MAX(zpadlen, spadlen);
		spadlen = 0;
	}
	if (flags & DP_F_MINUS)
		spadlen = -spadlen; /* Left Justifty */

	/* Spaces */
	while (spadlen > 0) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		--spadlen;
	}

	/* Sign */
	if (signvalue)
		dopr_outch(buffer, currlen, maxlen, signvalue);

	/* Zeros */
	if (zpadlen > 0) {
		while (zpadlen > 0) {
			dopr_outch(buffer, currlen, maxlen, '0');
			--zpadlen;
		}
	}

	/* Digits */
	while (place > 0)
		dopr_outch(buffer, currlen, maxlen, convert[--place]);

	/* Left Justified spaces */
	while (spadlen < 0) {
		dopr_outch (buffer, currlen, maxlen, ' ');
		++spadlen;
	}
}

static long double
pow10(int exp)
{
	long double result = 1;

	while (exp) {
		result *= 10;
		exp--;
	}

	return result;
}

static long
round(long double value)
{
	long intpart = value;

	value -= intpart;
	if (value >= 0.5)
		intpart++;

	return intpart;
}

static void
fmtfp(char *buffer, size_t *currlen, size_t maxlen, long double fvalue,
      int min, int max, int flags)
{
	char iconvert[20], fconvert[20];
	int signvalue = 0, iplace = 0, fplace = 0;
	int padlen = 0; /* amount to pad */
	int zpadlen = 0, caps = 0;
	long intpart, fracpart;
	long double ufvalue;

	/*
	 * AIX manpage says the default is 0, but Solaris says the default
	 * is 6, and sprintf on AIX defaults to 6
	 */
	if (max < 0)
		max = 6;

	ufvalue = abs_val(fvalue);

	if (fvalue < 0)
		signvalue = '-';
	else if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
		signvalue = '+';
	else if (flags & DP_F_SPACE)
		signvalue = ' ';

	intpart = ufvalue;

	/*
	 * Sorry, we only support 9 digits past the decimal because of our
	 * conversion method
	 */
	if (max > 9)
		max = 9;

	/* We "cheat" by converting the fractional part to integer by
	 * multiplying by a factor of 10
	 */
	fracpart = round((pow10 (max)) * (ufvalue - intpart));

	if (fracpart >= pow10 (max)) {
		intpart++;
		fracpart -= pow10 (max);
	}

	/* Convert integer part */
	do {
		iconvert[iplace++] =
		    (caps ? "0123456789ABCDEF" : "0123456789abcdef")
		    [intpart % 10];
		intpart = (intpart / 10);
	} while(intpart && (iplace < 20));
	if (iplace == 20)
		iplace--;
	iconvert[iplace] = 0;

	/* Convert fractional part */
	do {
		fconvert[fplace++] =
		    (caps ? "0123456789ABCDEF" : "0123456789abcdef")
		    [fracpart % 10];
		fracpart = (fracpart / 10);
	} while(fracpart && (fplace < 20));
	if (fplace == 20)
		fplace--;
	fconvert[fplace] = 0;

	/* -1 for decimal point, another -1 if we are printing a sign */
	padlen = min - iplace - max - 1 - ((signvalue) ? 1 : 0);
	zpadlen = max - fplace;
	if (zpadlen < 0)
		zpadlen = 0;
	if (padlen < 0)
		padlen = 0;
	if (flags & DP_F_MINUS)
		padlen = -padlen; /* Left Justifty */

	if ((flags & DP_F_ZERO) && (padlen > 0)) {
		if (signvalue) {
			dopr_outch(buffer, currlen, maxlen, signvalue);
			--padlen;
			signvalue = 0;
		}
		while (padlen > 0) {
			dopr_outch(buffer, currlen, maxlen, '0');
			--padlen;
		}
	}
	while (padlen > 0) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		--padlen;
	}
	if (signvalue)
		dopr_outch(buffer, currlen, maxlen, signvalue);

	while (iplace > 0)
		dopr_outch(buffer, currlen, maxlen, iconvert[--iplace]);

	/*
	 * Decimal point.  This should probably use locale to find the
	 * correct char to print out.
	 */
	dopr_outch(buffer, currlen, maxlen, '.');

	while (fplace > 0)
		dopr_outch(buffer, currlen, maxlen, fconvert[--fplace]);

	while (zpadlen > 0) {
		dopr_outch(buffer, currlen, maxlen, '0');
		--zpadlen;
	}

	while (padlen < 0) {
		dopr_outch(buffer, currlen, maxlen, ' ');
		++padlen;
	}
}

static void
dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c)
{
	if (*currlen < maxlen)
		buffer[(*currlen)++] = c;
}
#endif /* !defined(HAVE_SNPRINTF) || !defined(HAVE_VSNPRINTF) */

#ifndef HAVE_VSNPRINTF
int
vsnprintf(char *str, size_t count, const char *fmt, va_list args)
{
	str[0] = 0;
	dopr(str, count, fmt, args);

	return(strlen(str));
}
#endif /* !HAVE_VSNPRINTF */

#ifndef HAVE_SNPRINTF
int
snprintf(char *str,size_t count,const char *fmt,...)
{
	va_list ap;

	va_start(ap, fmt);
	(void) vsnprintf(str, count, fmt, ap);
	va_end(ap);

	return(strlen(str));
}

#endif /* !HAVE_SNPRINTF */