snprintf.c

samba服务器！

/*
 * NOTE: If you change this file, please merge it into rsync, samba, etc.
 */

/*
 * Copyright Patrick Powell 1995
 * This code is based on code written by Patrick Powell ([e-mail])
 * 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 <[e-mail]> 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 <[e-mail]> 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 <[e-mail]> 01/27/98 for mutt 0.89i
 *    The PGP code was using unsigned hexadecimal formats. 
 *    Unfortunately, unsigned formats simply didn't work.
 *
 *  Michael Elkins <[e-mail]> 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.
 *
 *  Andrew Tridgell ([e-mail]) Oct 1998
 *    fixed handling of %.0f
 *    added test for HAVE_LONG_DOUBLE
 *
 * [e-mail], [e-mail], April 2001
 *    got rid of fcvt code (twas buggy and made testing harder)
 *    added C99 semantics
 *
 * date: 2002/12/19 19:56:31;  author: herb;  state: Exp;  lines: +2 -0
 * actually print args for %g and %e
 * 
 * date: 2002/06/03 13:37:52;  author: jmcd;  state: Exp;  lines: +8 -0
 * Since includes.h isn't included here, VA_COPY has to be defined here.  I don't
 * see any include file that is guaranteed to be here, so I'm defining it
 * locally.  Fixes AIX and Solaris builds.
 * 
 * date: 2002/06/03 03:07:24;  author: tridge;  state: Exp;  lines: +5 -13
 * put the ifdef for HAVE_VA_COPY in one place rather than in lots of
 * functions
 * 
 * date: 2002/05/17 14:51:22;  author: jmcd;  state: Exp;  lines: +21 -4
 * Fix usage of va_list passed as an arg.  Use __va_copy before using it
 * when it exists.
 * 
 * date: 2002/04/16 22:38:04;  author: idra;  state: Exp;  lines: +20 -14
 * Fix incorrect zpadlen handling in fmtfp.
 * Thanks to Ollie Oldham <[e-mail]> for spotting it.
 * few mods to make it easier to compile the tests.
 * addedd the "Ollie" test to the floating point ones.
 *
 * Martin Pool ([e-mail]) April 2003
 *    Remove NO_CONFIG_H so that the test case can be built within a source
 *    tree with less trouble.
 *    Remove unnecessary SAFE_FREE() definition.
 *
 * Martin Pool ([e-mail]) May 2003
 *    Put in a prototype for dummy_snprintf() to quiet compiler warnings.
 *
 *    Move #endif to make sure VA_COPY, LDOUBLE, etc are defined even
 *    if the C library has some snprintf functions already.
 *
 * Darren Tucker ([e-mail]) 2005
 *    Fix bug allowing read overruns of the source string with "%.*s"
 *    Usually harmless unless the read runs outside the process' allocation
 *    (eg if your malloc does guard pages) in which case it will segfault.
 *    From OpenSSH.  Also added test for same.
 *
 * Simo Sorce ([e-mail]) Jan 2006
 * 
 *    Add support for position independent parameters 
 *    fix fmtstr now it conforms to sprintf wrt min.max
 *
 **************************************************************/

#include "replace.h"
#include "system/locale.h"

#ifdef TEST_SNPRINTF /* need math library headers for testing */

/* In test mode, we pretend that this system doesn't have any snprintf
 * functions, regardless of what config.h says. */
#  undef HAVE_SNPRINTF
#  undef HAVE_VSNPRINTF
#  undef HAVE_C99_VSNPRINTF
#  undef HAVE_ASPRINTF
#  undef HAVE_VASPRINTF
#  include <math.h>
#endif /* TEST_SNPRINTF */

#if defined(HAVE_SNPRINTF) && defined(HAVE_VSNPRINTF) && defined(HAVE_C99_VSNPRINTF)
/* only include stdio.h if we are not re-defining snprintf or vsnprintf */
#include <stdio.h>
 /* make the compiler happy with an empty file */
 void dummy_snprintf(void);
 void dummy_snprintf(void) {} 
#endif /* HAVE_SNPRINTF, etc */

/* yes this really must be a ||. Don't muck with this (tridge) */
#if !defined(HAVE_VSNPRINTF) || !defined(HAVE_C99_VSNPRINTF)

#ifdef HAVE_LONG_DOUBLE
#define LDOUBLE long double
#else
#define LDOUBLE double
#endif

#ifdef HAVE_LONG_LONG
#define LLONG long long
#else
#define LLONG long
#endif

#ifndef VA_COPY
#ifdef HAVE_VA_COPY
#define VA_COPY(dest, src) va_copy(dest, src)
#else
#ifdef HAVE___VA_COPY
#define VA_COPY(dest, src) __va_copy(dest, src)
#else
#define VA_COPY(dest, src) (dest) = (src)
#endif
#endif

/*
 * 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_CHAR    1
#define DP_C_SHORT   2
#define DP_C_LONG    3
#define DP_C_LDOUBLE 4
#define DP_C_LLONG   5
#define DP_C_SIZET   6

/* Chunk types */
#define CNK_FMT_STR 0
#define CNK_INT     1
#define CNK_OCTAL   2
#define CNK_UINT    3
#define CNK_HEX     4
#define CNK_FLOAT   5
#define CNK_CHAR    6
#define CNK_STRING  7
#define CNK_PTR     8
#define CNK_NUM     9
#define CNK_PRCNT   10

#define char_to_int(p) ((p)- '0')
#ifndef MAX
#define MAX(p,q) (((p) >= (q)) ? (p) : (q))
#endif

struct pr_chunk {
	int type; /* chunk type */
	int num; /* parameter number */
	int min; 
	int max;
	int flags;
	int cflags;
	int start;
	int len;
	LLONG value;
	LDOUBLE fvalue;
	char *strvalue;
	void *pnum;
	struct pr_chunk *min_star;
	struct pr_chunk *max_star;
	struct pr_chunk *next;
};

struct pr_chunk_x {
	struct pr_chunk **chunks;
	int num;
};

static int dopr(char *buffer, size_t maxlen, const char *format, 
		   va_list args_in);
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,
		    LLONG value, int base, int min, int max, int flags);
static void fmtfp(char *buffer, size_t *currlen, size_t maxlen,
		   LDOUBLE fvalue, int min, int max, int flags);
static void dopr_outch(char *buffer, size_t *currlen, size_t maxlen, char c);
static struct pr_chunk *new_chunk(void);
static int add_cnk_list_entry(struct pr_chunk_x **list,
				int max_num, struct pr_chunk *chunk);

static int dopr(char *buffer, size_t maxlen, const char *format, va_list args_in)
{
	char ch;
	int state;
	int pflag;
	int pnum;
	int pfirst;
	size_t currlen;
	va_list args;
	const char *base;
	struct pr_chunk *chunks = NULL;
	struct pr_chunk *cnk = NULL;
	struct pr_chunk_x *clist = NULL;
	int max_pos;
	int ret = -1;

	VA_COPY(args, args_in);

	state = DP_S_DEFAULT;
	pfirst = 1;
	pflag = 0;
	pnum = 0;

	max_pos = 0;
	base = format;
	ch = *format++;
	
	/* retrieve the string structure as chunks */
	while (state != DP_S_DONE) {
		if (ch == '\0') 
			state = DP_S_DONE;

		switch(state) {
		case DP_S_DEFAULT:
			
			if (cnk) {
				cnk->next = new_chunk();
				cnk = cnk->next;
			} else {
				cnk = new_chunk();
			}
			if (!cnk) goto done;
			if (!chunks) chunks = cnk;
			
			if (ch == '%') {
				state = DP_S_FLAGS;
				ch = *format++;
			} else {
				cnk->type = CNK_FMT_STR;
				cnk->start = format - base -1;
				while ((ch != '\0') && (ch != '%')) ch = *format++;
				cnk->len = format - base - cnk->start -1;
			}
			break;
		case DP_S_FLAGS:
			switch (ch) {
			case '-':
				cnk->flags |= DP_F_MINUS;
				ch = *format++;
				break;
			case '+':
				cnk->flags |= DP_F_PLUS;
				ch = *format++;
				break;
			case ' ':
				cnk->flags |= DP_F_SPACE;
				ch = *format++;
				break;
			case '#':
				cnk->flags |= DP_F_NUM;
				ch = *format++;
				break;
			case '0':
				cnk->flags |= DP_F_ZERO;
				ch = *format++;
				break;
			case 'I':
				/* internationalization not supported yet */
				ch = *format++;
				break;
			default:
				state = DP_S_MIN;
				break;
			}
			break;
		case DP_S_MIN:
			if (isdigit((unsigned char)ch)) {
				cnk->min = 10 * cnk->min + char_to_int (ch);
				ch = *format++;
			} else if (ch == '$') {
				if (!pfirst && !pflag) {
					/* parameters must be all positioned or none */
					goto done;
				}
				if (pfirst) {
					pfirst = 0;
					pflag = 1;
				}
				if (cnk->min == 0) /* what ?? */
					goto done;
				cnk->num = cnk->min;
				cnk->min = 0;
				ch = *format++;
			} else if (ch == '*') {
				if (pfirst) pfirst = 0;
				cnk->min_star = new_chunk();
				if (!cnk->min_star) /* out of memory :-( */
					goto done;
				cnk->min_star->type = CNK_INT;
				if (pflag) {
					int num;
					ch = *format++;
					if (!isdigit((unsigned char)ch)) {
						/* parameters must be all positioned or none */
						goto done;
					}
					for (num = 0; isdigit((unsigned char)ch); ch = *format++) {
						num = 10 * num + char_to_int(ch);
					}
					cnk->min_star->num = num;
					if (ch != '$') /* what ?? */
						goto done;
				} else {
					cnk->min_star->num = ++pnum;
				}
				max_pos = add_cnk_list_entry(&clist, max_pos, cnk->min_star);
				if (max_pos == 0) /* out of memory :-( */
					goto done;
				ch = *format++;
				state = DP_S_DOT;
			} else {
				if (pfirst) pfirst = 0;
				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 (cnk->max < 0)
					cnk->max = 0;
				cnk->max = 10 * cnk->max + char_to_int (ch);
				ch = *format++;
			} else if (ch == '$') {
				if (!pfirst && !pflag) {
					/* parameters must be all positioned or none */
					goto done;
				}
				if (cnk->max <= 0) /* what ?? */
					goto done;
				cnk->num = cnk->max;
				cnk->max = -1;
				ch = *format++;
			} else if (ch == '*') {
				cnk->max_star = new_chunk();
				if (!cnk->max_star) /* out of memory :-( */
					goto done;
				cnk->max_star->type = CNK_INT;
				if (pflag) {
					int num;
					ch = *format++;
					if (!isdigit((unsigned char)ch)) {
						/* parameters must be all positioned or none */
						goto done;
					}
					for (num = 0; isdigit((unsigned char)ch); ch = *format++) {
						num = 10 * num + char_to_int(ch);
					}
					cnk->max_star->num = num;
					if (ch != '$') /* what ?? */
						goto done;
				} else {
					cnk->max_star->num = ++pnum;
				}
				max_pos = add_cnk_list_entry(&clist, max_pos, cnk->max_star);
				if (max_pos == 0) /* out of memory :-( */
					goto done;

				ch = *format++;
				state = DP_S_MOD;
			} else {
				state = DP_S_MOD;
			}
			break;
		case DP_S_MOD:
			switch (ch) {
			case 'h':
				cnk->cflags = DP_C_SHORT;
				ch = *format++;
				if (ch == 'h') {
					cnk->cflags = DP_C_CHAR;
					ch = *format++;
				}
				break;
			case 'l':
				cnk->cflags = DP_C_LONG;
				ch = *format++;
				if (ch == 'l') {	/* It's a long long */
					cnk->cflags = DP_C_LLONG;
					ch = *format++;
				}
				break;
			case 'L':
				cnk->cflags = DP_C_LDOUBLE;
				ch = *format++;
				break;
			case 'z':
				cnk->cflags = DP_C_SIZET;
				ch = *format++;
				break;
			default:
				break;
			}
			state = DP_S_CONV;
			break;
		case DP_S_CONV:
			if (cnk->num == 0) cnk->num = ++pnum;
			max_pos = add_cnk_list_entry(&clist, max_pos, cnk);
			if (max_pos == 0) /* out of memory :-( */
				goto done;
			
			switch (ch) {
			case 'd':
			case 'i':
				cnk->type = CNK_INT;
				break;
			case 'o':
				cnk->type = CNK_OCTAL;
				cnk->flags |= DP_F_UNSIGNED;
				break;
			case 'u':
				cnk->type = CNK_UINT;
				cnk->flags |= DP_F_UNSIGNED;
				break;
			case 'X':
				cnk->flags |= DP_F_UP;
			case 'x':
				cnk->type = CNK_HEX;
				cnk->flags |= DP_F_UNSIGNED;
				break;
			case 'A':
				/* hex float not supported yet */
			case 'E':
			case 'G':
			case 'F':
				cnk->flags |= DP_F_UP;
			case 'a':
				/* hex float not supported yet */
			case 'e':
			case 'f':
			case 'g':
				cnk->type = CNK_FLOAT;
				break;
			case 'c':
				cnk->type = CNK_CHAR;
				break;
			case 's':
				cnk->type = CNK_STRING;
				break;
			case 'p':
				cnk->type = CNK_PTR;
				break;
			case 'n':
				cnk->type = CNK_NUM;
				break;
			case '%':