freebsd-dev/sys/kern/subr_scanf.c
Pedro F. Giffuni 51369649b0 sys: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:43:44 +00:00

644 lines
15 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Chris Torek.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* From: Id: vfscanf.c,v 1.13 1998/09/25 12:20:27 obrien Exp
* From: static char sccsid[] = "@(#)strtol.c 8.1 (Berkeley) 6/4/93";
* From: static char sccsid[] = "@(#)strtoul.c 8.1 (Berkeley) 6/4/93";
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ctype.h>
#include <sys/limits.h>
/*
* Note that stdarg.h and the ANSI style va_start macro is used for both
* ANSI and traditional C compilers.
*/
#include <machine/stdarg.h>
#define BUF 32 /* Maximum length of numeric string. */
/*
* Flags used during conversion.
*/
#define LONG 0x01 /* l: long or double */
#define SHORT 0x04 /* h: short */
#define SUPPRESS 0x08 /* suppress assignment */
#define POINTER 0x10 /* weird %p pointer (`fake hex') */
#define NOSKIP 0x20 /* do not skip blanks */
#define QUAD 0x400
#define SHORTSHORT 0x4000 /** hh: char */
/*
* The following are used in numeric conversions only:
* SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
* SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
*/
#define SIGNOK 0x40 /* +/- is (still) legal */
#define NDIGITS 0x80 /* no digits detected */
#define DPTOK 0x100 /* (float) decimal point is still legal */
#define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */
#define PFXOK 0x100 /* 0x prefix is (still) legal */
#define NZDIGITS 0x200 /* no zero digits detected */
/*
* Conversion types.
*/
#define CT_CHAR 0 /* %c conversion */
#define CT_CCL 1 /* %[...] conversion */
#define CT_STRING 2 /* %s conversion */
#define CT_INT 3 /* integer, i.e., strtoq or strtouq */
typedef u_quad_t (*ccfntype)(const char *, char **, int);
static const u_char *__sccl(char *, const u_char *);
int
sscanf(const char *ibuf, const char *fmt, ...)
{
va_list ap;
int ret;
va_start(ap, fmt);
ret = vsscanf(ibuf, fmt, ap);
va_end(ap);
return(ret);
}
int
vsscanf(const char *inp, char const *fmt0, va_list ap)
{
int inr;
const u_char *fmt = (const u_char *)fmt0;
int c; /* character from format, or conversion */
size_t width; /* field width, or 0 */
char *p; /* points into all kinds of strings */
int n; /* handy integer */
int flags; /* flags as defined above */
char *p0; /* saves original value of p when necessary */
int nassigned; /* number of fields assigned */
int nconversions; /* number of conversions */
int nread; /* number of characters consumed from fp */
int base; /* base argument to strtoq/strtouq */
ccfntype ccfn; /* conversion function (strtoq/strtouq) */
char ccltab[256]; /* character class table for %[...] */
char buf[BUF]; /* buffer for numeric conversions */
/* `basefix' is used to avoid `if' tests in the integer scanner */
static short basefix[17] =
{ 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 };
inr = strlen(inp);
nassigned = 0;
nconversions = 0;
nread = 0;
base = 0; /* XXX just to keep gcc happy */
ccfn = NULL; /* XXX just to keep gcc happy */
for (;;) {
c = *fmt++;
if (c == 0)
return (nassigned);
if (isspace(c)) {
while (inr > 0 && isspace(*inp))
nread++, inr--, inp++;
continue;
}
if (c != '%')
goto literal;
width = 0;
flags = 0;
/*
* switch on the format. continue if done;
* break once format type is derived.
*/
again: c = *fmt++;
switch (c) {
case '%':
literal:
if (inr <= 0)
goto input_failure;
if (*inp != c)
goto match_failure;
inr--, inp++;
nread++;
continue;
case '*':
flags |= SUPPRESS;
goto again;
case 'l':
if (flags & LONG){
flags &= ~LONG;
flags |= QUAD;
} else {
flags |= LONG;
}
goto again;
case 'q':
flags |= QUAD;
goto again;
case 'h':
if (flags & SHORT){
flags &= ~SHORT;
flags |= SHORTSHORT;
} else {
flags |= SHORT;
}
goto again;
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
width = width * 10 + c - '0';
goto again;
/*
* Conversions.
*
*/
case 'd':
c = CT_INT;
ccfn = (ccfntype)strtoq;
base = 10;
break;
case 'i':
c = CT_INT;
ccfn = (ccfntype)strtoq;
base = 0;
break;
case 'o':
c = CT_INT;
ccfn = strtouq;
base = 8;
break;
case 'u':
c = CT_INT;
ccfn = strtouq;
base = 10;
break;
case 'x':
flags |= PFXOK; /* enable 0x prefixing */
c = CT_INT;
ccfn = strtouq;
base = 16;
break;
case 's':
c = CT_STRING;
break;
case '[':
fmt = __sccl(ccltab, fmt);
flags |= NOSKIP;
c = CT_CCL;
break;
case 'c':
flags |= NOSKIP;
c = CT_CHAR;
break;
case 'p': /* pointer format is like hex */
flags |= POINTER | PFXOK;
c = CT_INT;
ccfn = strtouq;
base = 16;
break;
case 'n':
nconversions++;
if (flags & SUPPRESS) /* ??? */
continue;
if (flags & SHORTSHORT)
*va_arg(ap, char *) = nread;
else if (flags & SHORT)
*va_arg(ap, short *) = nread;
else if (flags & LONG)
*va_arg(ap, long *) = nread;
else if (flags & QUAD)
*va_arg(ap, quad_t *) = nread;
else
*va_arg(ap, int *) = nread;
continue;
}
/*
* We have a conversion that requires input.
*/
if (inr <= 0)
goto input_failure;
/*
* Consume leading white space, except for formats
* that suppress this.
*/
if ((flags & NOSKIP) == 0) {
while (isspace(*inp)) {
nread++;
if (--inr > 0)
inp++;
else
goto input_failure;
}
/*
* Note that there is at least one character in
* the buffer, so conversions that do not set NOSKIP
* can no longer result in an input failure.
*/
}
/*
* Do the conversion.
*/
switch (c) {
case CT_CHAR:
/* scan arbitrary characters (sets NOSKIP) */
if (width == 0)
width = 1;
if (flags & SUPPRESS) {
size_t sum = 0;
for (;;) {
if ((n = inr) < width) {
sum += n;
width -= n;
inp += n;
if (sum == 0)
goto input_failure;
break;
} else {
sum += width;
inr -= width;
inp += width;
break;
}
}
nread += sum;
} else {
bcopy(inp, va_arg(ap, char *), width);
inr -= width;
inp += width;
nread += width;
nassigned++;
}
nconversions++;
break;
case CT_CCL:
/* scan a (nonempty) character class (sets NOSKIP) */
if (width == 0)
width = (size_t)~0; /* `infinity' */
/* take only those things in the class */
if (flags & SUPPRESS) {
n = 0;
while (ccltab[(unsigned char)*inp]) {
n++, inr--, inp++;
if (--width == 0)
break;
if (inr <= 0) {
if (n == 0)
goto input_failure;
break;
}
}
if (n == 0)
goto match_failure;
} else {
p0 = p = va_arg(ap, char *);
while (ccltab[(unsigned char)*inp]) {
inr--;
*p++ = *inp++;
if (--width == 0)
break;
if (inr <= 0) {
if (p == p0)
goto input_failure;
break;
}
}
n = p - p0;
if (n == 0)
goto match_failure;
*p = 0;
nassigned++;
}
nread += n;
nconversions++;
break;
case CT_STRING:
/* like CCL, but zero-length string OK, & no NOSKIP */
if (width == 0)
width = (size_t)~0;
if (flags & SUPPRESS) {
n = 0;
while (!isspace(*inp)) {
n++, inr--, inp++;
if (--width == 0)
break;
if (inr <= 0)
break;
}
nread += n;
} else {
p0 = p = va_arg(ap, char *);
while (!isspace(*inp)) {
inr--;
*p++ = *inp++;
if (--width == 0)
break;
if (inr <= 0)
break;
}
*p = 0;
nread += p - p0;
nassigned++;
}
nconversions++;
continue;
case CT_INT:
/* scan an integer as if by strtoq/strtouq */
#ifdef hardway
if (width == 0 || width > sizeof(buf) - 1)
width = sizeof(buf) - 1;
#else
/* size_t is unsigned, hence this optimisation */
if (--width > sizeof(buf) - 2)
width = sizeof(buf) - 2;
width++;
#endif
flags |= SIGNOK | NDIGITS | NZDIGITS;
for (p = buf; width; width--) {
c = *inp;
/*
* Switch on the character; `goto ok'
* if we accept it as a part of number.
*/
switch (c) {
/*
* The digit 0 is always legal, but is
* special. For %i conversions, if no
* digits (zero or nonzero) have been
* scanned (only signs), we will have
* base==0. In that case, we should set
* it to 8 and enable 0x prefixing.
* Also, if we have not scanned zero digits
* before this, do not turn off prefixing
* (someone else will turn it off if we
* have scanned any nonzero digits).
*/
case '0':
if (base == 0) {
base = 8;
flags |= PFXOK;
}
if (flags & NZDIGITS)
flags &= ~(SIGNOK|NZDIGITS|NDIGITS);
else
flags &= ~(SIGNOK|PFXOK|NDIGITS);
goto ok;
/* 1 through 7 always legal */
case '1': case '2': case '3':
case '4': case '5': case '6': case '7':
base = basefix[base];
flags &= ~(SIGNOK | PFXOK | NDIGITS);
goto ok;
/* digits 8 and 9 ok iff decimal or hex */
case '8': case '9':
base = basefix[base];
if (base <= 8)
break; /* not legal here */
flags &= ~(SIGNOK | PFXOK | NDIGITS);
goto ok;
/* letters ok iff hex */
case 'A': case 'B': case 'C':
case 'D': case 'E': case 'F':
case 'a': case 'b': case 'c':
case 'd': case 'e': case 'f':
/* no need to fix base here */
if (base <= 10)
break; /* not legal here */
flags &= ~(SIGNOK | PFXOK | NDIGITS);
goto ok;
/* sign ok only as first character */
case '+': case '-':
if (flags & SIGNOK) {
flags &= ~SIGNOK;
goto ok;
}
break;
/* x ok iff flag still set & 2nd char */
case 'x': case 'X':
if (flags & PFXOK && p == buf + 1) {
base = 16; /* if %i */
flags &= ~PFXOK;
goto ok;
}
break;
}
/*
* If we got here, c is not a legal character
* for a number. Stop accumulating digits.
*/
break;
ok:
/*
* c is legal: store it and look at the next.
*/
*p++ = c;
if (--inr > 0)
inp++;
else
break; /* end of input */
}
/*
* If we had only a sign, it is no good; push
* back the sign. If the number ends in `x',
* it was [sign] '0' 'x', so push back the x
* and treat it as [sign] '0'.
*/
if (flags & NDIGITS) {
if (p > buf) {
inp--;
inr++;
}
goto match_failure;
}
c = ((u_char *)p)[-1];
if (c == 'x' || c == 'X') {
--p;
inp--;
inr++;
}
if ((flags & SUPPRESS) == 0) {
u_quad_t res;
*p = 0;
res = (*ccfn)(buf, (char **)NULL, base);
if (flags & POINTER)
*va_arg(ap, void **) =
(void *)(uintptr_t)res;
else if (flags & SHORTSHORT)
*va_arg(ap, char *) = res;
else if (flags & SHORT)
*va_arg(ap, short *) = res;
else if (flags & LONG)
*va_arg(ap, long *) = res;
else if (flags & QUAD)
*va_arg(ap, quad_t *) = res;
else
*va_arg(ap, int *) = res;
nassigned++;
}
nread += p - buf;
nconversions++;
break;
}
}
input_failure:
return (nconversions != 0 ? nassigned : -1);
match_failure:
return (nassigned);
}
/*
* Fill in the given table from the scanset at the given format
* (just after `['). Return a pointer to the character past the
* closing `]'. The table has a 1 wherever characters should be
* considered part of the scanset.
*/
static const u_char *
__sccl(char *tab, const u_char *fmt)
{
int c, n, v;
/* first `clear' the whole table */
c = *fmt++; /* first char hat => negated scanset */
if (c == '^') {
v = 1; /* default => accept */
c = *fmt++; /* get new first char */
} else
v = 0; /* default => reject */
/* XXX: Will not work if sizeof(tab*) > sizeof(char) */
for (n = 0; n < 256; n++)
tab[n] = v; /* memset(tab, v, 256) */
if (c == 0)
return (fmt - 1);/* format ended before closing ] */
/*
* Now set the entries corresponding to the actual scanset
* to the opposite of the above.
*
* The first character may be ']' (or '-') without being special;
* the last character may be '-'.
*/
v = 1 - v;
for (;;) {
tab[c] = v; /* take character c */
doswitch:
n = *fmt++; /* and examine the next */
switch (n) {
case 0: /* format ended too soon */
return (fmt - 1);
case '-':
/*
* A scanset of the form
* [01+-]
* is defined as `the digit 0, the digit 1,
* the character +, the character -', but
* the effect of a scanset such as
* [a-zA-Z0-9]
* is implementation defined. The V7 Unix
* scanf treats `a-z' as `the letters a through
* z', but treats `a-a' as `the letter a, the
* character -, and the letter a'.
*
* For compatibility, the `-' is not considered
* to define a range if the character following
* it is either a close bracket (required by ANSI)
* or is not numerically greater than the character
* we just stored in the table (c).
*/
n = *fmt;
if (n == ']' || n < c) {
c = '-';
break; /* resume the for(;;) */
}
fmt++;
/* fill in the range */
do {
tab[++c] = v;
} while (c < n);
c = n;
/*
* Alas, the V7 Unix scanf also treats formats
* such as [a-c-e] as `the letters a through e'.
* This too is permitted by the standard....
*/
goto doswitch;
break;
case ']': /* end of scanset */
return (fmt);
default: /* just another character */
c = n;
break;
}
}
/* NOTREACHED */
}