/* $OpenBSD: vfscanf.c,v 1.31 2014/03/19 05:17:01 guenther Exp $ */
/*-
* 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.
*/
#include <inttypes.h>
#include <stdarg.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/param.h>
#include <wctype.h>
#include "local.h"
#include <private/bionic_ctype.h>
#include <private/bionic_fortify.h>
#include <private/bionic_macros.h>
#include <private/bionic_mbstate.h>
#define BUF 513 /* Maximum length of numeric string. */
// Flags used during conversion.
// Size/type:
#define LONG 0x00001 // l: long or double
#define LONGDBL 0x00002 // L: long double
#define SHORT 0x00004 // h: short
#define SHORTSHORT 0x00008 // hh: 8 bit integer
#define LLONG 0x00010 // ll: long long (+ deprecated q: quad)
#define POINTER 0x00020 // p: void* (as hex)
#define SIZEINT 0x00040 // z: (signed) size_t
#define MAXINT 0x00080 // j: intmax_t
#define PTRINT 0x00100 // t: ptrdiff_t
#define NOSKIP 0x00200 // [ or c: do not skip blanks
// Modifiers:
#define SUPPRESS 0x00400 // *: suppress assignment
#define UNSIGNED 0x00800 // %[oupxX] conversions
#define ALLOCATE 0x01000 // m: allocate a char*
// Internal use during integer parsing:
#define SIGNOK 0x02000 // +/- is (still) legal
#define HAVESIGN 0x04000 // Sign detected
#define NDIGITS 0x08000 // No digits detected
#define PFXOK 0x10000 // "0x" prefix is (still) legal
#define NZDIGITS 0x20000 // 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: strtoimax/strtoumax
#define CT_FLOAT 4 // Float: strtod
static const unsigned char* __sccl(char*, const unsigned char*);
/*
* Internal, unlocked version of vfscanf
*/
int __svfscanf(FILE* fp, const char* fmt0, va_list ap) {
const unsigned char* fmt = reinterpret_cast<const unsigned char*>(fmt0);
int c; /* character from format, or conversion */
size_t width; /* field width, or 0 */
char* p;
wchar_t* wcp;
size_t n;
int flags; /* flags as defined above */
int nassigned; /* number of fields assigned */
int nread; /* number of characters consumed from fp */
int base; /* base argument to strtoimax/strtouimax */
char ccltab[256]; /* character class table for %[...] */
char buf[BUF]; /* buffer for numeric conversions */
size_t nconv; /* length of multibyte sequence converted */
mbstate_t mbs;
void* allocation = nullptr; // Allocated but unassigned result for %mc/%ms/%m[.
size_t capacity = 0; // Number of char/wchar_t units allocated in `allocation`.
/* `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 };
_SET_ORIENTATION(fp, -1);
nassigned = 0;
nread = 0;
for (;;) {
c = *fmt++;
if (c == 0) return nassigned;
if (IsSpace(c)) {
while ((fp->_r > 0 || __srefill(fp) == 0) && IsSpace(*fp->_p)) nread++, fp->_r--, fp->_p++;
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 (fp->_r <= 0 && __srefill(fp)) goto input_failure;
if (*fp->_p != c) goto match_failure;
fp->_r--, fp->_p++;
nread++;
continue;
case '*':
flags |= SUPPRESS;
goto again;
case 'j':
flags |= MAXINT;
goto again;
case 'L':
flags |= LONGDBL;
goto again;
case 'h':
if (*fmt == 'h') {
fmt++;
flags |= SHORTSHORT;
} else {
flags |= SHORT;
}
goto again;
case 'l':
if (*fmt == 'l') {
fmt++;
flags |= LLONG;
} else {
flags |= LONG;
}
goto again;
case 'm':
flags |= ALLOCATE;
goto again;
case 'q':
flags |= LLONG; /* deprecated */
goto again;
case 't':
flags |= PTRINT;
goto again;
case 'z':
flags |= SIZEINT;
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.
* Those marked `compat' are for 4.[123]BSD compatibility.
*/
case 'D': /* compat */
flags |= LONG;
__BIONIC_FALLTHROUGH;
case 'd':
c = CT_INT;
base = 10;
break;
case 'i':
c = CT_INT;
base = 0;
break;
case 'O': /* compat */
flags |= LONG;
__BIONIC_FALLTHROUGH;
case 'o':
c = CT_INT;
flags |= UNSIGNED;
base = 8;
break;
case 'u':
c = CT_INT;
flags |= UNSIGNED;
base = 10;
break;
case 'X':
case 'x':
flags |= PFXOK; /* enable 0x prefixing */
c = CT_INT;
flags |= UNSIGNED;
base = 16;
break;
case 'e':
case 'E':
case 'f':
case 'F':
case 'g':
case 'G':
case 'a':
case 'A':
c = CT_FLOAT;
break;
case 's':
memset(ccltab, 1, 256);
ccltab['\t'] = ccltab['\n'] = ccltab['\v'] = ccltab['\f'] = ccltab['\r'] = ccltab[' '] = 0;
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;
flags |= UNSIGNED;
base = 16;
break;
case 'n':
if (flags & SUPPRESS) continue;
if (flags & SHORTSHORT) {
*va_arg(ap, signed char*) = nread;
} else if (flags & SHORT) {
*va_arg(ap, short*) = nread;
} else if (flags & LONG) {
*va_arg(ap, long*) = nread;
} else if (flags & SIZEINT) {
*va_arg(ap, ssize_t*) = nread;
} else if (flags & PTRINT) {
*va_arg(ap, ptrdiff_t*) = nread;
} else if (flags & LLONG) {
*va_arg(ap, long long*) = nread;
} else if (flags & MAXINT) {
*va_arg(ap, intmax_t*) = nread;
} else {
*va_arg(ap, int*) = nread;
}
continue;
/*
* Disgusting backwards compatibility hacks. XXX
*/
case '\0': /* compat */
return EOF;
default: /* compat */
if (IsUpper(c)) flags |= LONG;
c = CT_INT;
base = 10;
break;
}
if ((flags & ALLOCATE) != 0 && c > CT_STRING) {
__fortify_fatal("scanf 'm' only works with %%c/%%s/%%[");
}
if ((flags & (ALLOCATE|SUPPRESS)) == (ALLOCATE|SUPPRESS)) {
__fortify_fatal("scanf 'm' makes no sense with '*'");
}
/*
* We have a conversion that requires input.
*/
if (fp->_r <= 0 && __srefill(fp)) goto input_failure;
/*
* Consume leading white space, except for formats
* that suppress this.
*/
if ((flags & NOSKIP) == 0) {
while (IsSpace(*fp->_p)) {
nread++;
if (--fp->_r > 0) {
fp->_p++;
} else if (__srefill(fp)) {
goto input_failure;
}
}
/*
* Note that there is at least one character in
* the buffer, so conversions that do not set NOSKIP
* ca 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 & LONG) {
if (flags & ALLOCATE) {
allocation = wcp = reinterpret_cast<wchar_t*>(malloc(width * sizeof(wchar_t)));
if (allocation == nullptr) goto allocation_failure;
} else if (flags & SUPPRESS) {
wcp = nullptr;
} else {
wcp = va_arg(ap, wchar_t*);
}
size_t bytes = 0;
while (width != 0) {
if (bytes == MB_CUR_MAX) {
fp->_flags |= __SERR;
goto input_failure;
}
buf[bytes++] = *fp->_p;
fp->_p++;
fp->_r--;
memset(&mbs, 0, sizeof(mbs));
nconv = mbrtowc(wcp, buf, bytes, &mbs);
if (nconv == __MB_ERR_ILLEGAL_SEQUENCE) {
fp->_flags |= __SERR;
goto input_failure;
}
if (nconv == 0 && !(flags & SUPPRESS)) *wcp = L'\0';
if (nconv != __MB_ERR_INCOMPLETE_SEQUENCE) {
nread += bytes;
width--;
if (!(flags & SUPPRESS)) wcp++;
bytes = 0;
}
if (fp->_r <= 0 && __srefill(fp)) {
if (bytes != 0) {
fp->_flags |= __SERR;
goto input_failure;
}
break;
}
}
if (allocation != nullptr) {
*va_arg(ap, wchar_t**) = reinterpret_cast<wchar_t*>(allocation);
allocation = nullptr;
}
if (!(flags & SUPPRESS)) nassigned++;
} else if (flags & SUPPRESS) {
size_t sum = 0;
for (;;) {
if ((n = fp->_r) < width) {
sum += n;
width -= n;
fp->_p += n;
if (__srefill(fp)) {
if (sum == 0) goto input_failure;
break;
}
} else {
sum += width;
fp->_r -= width;
fp->_p += width;
break;
}
}
nread += sum;
} else {
if (flags & ALLOCATE) {
allocation = p = reinterpret_cast<char*>(malloc(width));
if (allocation == nullptr) goto allocation_failure;
} else {
p = va_arg(ap, char*);
}
size_t r = fread(p, 1, width, fp);
if (r == 0) goto input_failure;
if (allocation != nullptr) {
*va_arg(ap, char**) = reinterpret_cast<char*>(allocation);
allocation = nullptr;
}
nread += r;
nassigned++;
}
break;
case CT_CCL:
case CT_STRING:
// CT_CCL: scan a (nonempty) character class (sets NOSKIP).
// CT_STRING: like CCL, but zero-length string OK, & no NOSKIP.
if (width == 0) width = SIZE_MAX;
if (flags & LONG) {
// TODO: since no-one cares, replace this with a simple fgetwc loop?
n = 0;
if (flags & ALLOCATE) {
capacity = MIN(width, 32);
allocation = wcp = reinterpret_cast<wchar_t*>(malloc(sizeof(wchar_t) * capacity));
if (allocation == nullptr) goto allocation_failure;
} else if (flags & SUPPRESS) {
wcp = nullptr;
} else {
wcp = va_arg(ap, wchar_t*);
}
size_t bytes = 0;
while ((c == CT_CCL || !IsSpace(*fp->_p)) && width != 0) {
if (bytes == MB_CUR_MAX) {
fp->_flags |= __SERR;
goto input_failure;
}
buf[bytes++] = *fp->_p;
fp->_p++;
fp->_r--;
wchar_t wc = L'\0';
memset(&mbs, 0, sizeof(mbs));
nconv = mbrtowc(&wc, buf, bytes, &mbs);
if (nconv == __MB_ERR_ILLEGAL_SEQUENCE) {
fp->_flags |= __SERR;
goto input_failure;
}
if (nconv != __MB_ERR_INCOMPLETE_SEQUENCE) {
if ((c == CT_CCL && wctob(wc) != EOF && !ccltab[wctob(wc)]) || (c == CT_STRING && iswspace(wc))) {
while (bytes != 0) {
bytes--;
ungetc(buf[bytes], fp);
}
break;
}
if (wcp) wcp[n] = wc;
n++;
if (allocation != nullptr && n == capacity) {
capacity *= 2;
wchar_t* new_allocation =
reinterpret_cast<wchar_t*>(realloc(allocation, sizeof(wchar_t) * capacity));
if (new_allocation == nullptr) goto allocation_failure;
allocation = wcp = new_allocation;
}
nread += bytes;
width--;
bytes = 0;
}
if (fp->_r <= 0 && __srefill(fp)) {
if (bytes != 0) {
fp->_flags |= __SERR;
goto input_failure;
}
break;
}
}
if (c == CT_CCL && bytes != 0) {
fp->_flags |= __SERR;
goto input_failure;
}
if (allocation != nullptr) {
*va_arg(ap, wchar_t**) = reinterpret_cast<wchar_t*>(allocation);
allocation = nullptr;
}
} else if (flags & SUPPRESS) {
n = 0;
while (ccltab[*fp->_p]) {
n++, fp->_r--, fp->_p++;
if (--width == 0) break;
if (fp->_r <= 0 && __srefill(fp)) {
if (c == CT_CCL && n == 0) goto input_failure;
break;
}
}
nread += n;
} else {
if (flags & ALLOCATE) {
capacity = MIN(width, 32);
allocation = p = reinterpret_cast<char*>(malloc(capacity));
if (allocation == nullptr) goto allocation_failure;
} else {
p = va_arg(ap, char*);
}
n = 0;
while (ccltab[*fp->_p]) {
fp->_r--;
p[n++] = *fp->_p++;
if (allocation != nullptr && n == capacity) {
capacity *= 2;
char* new_allocation = reinterpret_cast<char*>(realloc(allocation, capacity));
if (new_allocation == nullptr) goto allocation_failure;
allocation = p = new_allocation;
}
if (--width == 0) break;
if (fp->_r <= 0 && __srefill(fp)) {
if (c == CT_CCL && n == 0) goto input_failure;
break;
}
}
nread += n;
if (allocation != nullptr) {
*va_arg(ap, char**) = reinterpret_cast<char*>(allocation);
allocation = nullptr;
}
}
if (c == CT_CCL && n == 0) goto match_failure;
if (!(flags & SUPPRESS)) {
if (flags & LONG) {
wcp[n] = L'\0';
} else {
p[n] = '\0';
}
++nassigned;
}
break;
case CT_INT:
/* scan an integer as if by strtoimax/strtoumax */
#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 = *fp->_p;
/*
* 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;
flags |= HAVESIGN;
goto ok;
}
break;
/*
* x ok iff flag still set and 2nd char (or
* 3rd char if we have a sign).
*/
case 'x':
case 'X':
if ((flags & PFXOK) && p == buf + 1 + !!(flags & HAVESIGN)) {
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 (--fp->_r > 0)
fp->_p++;
else if (__srefill(fp))
break; /* EOF */
}
/*
* 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) (void)ungetc(*(u_char*)--p, fp);
goto match_failure;
}
c = ((u_char*)p)[-1];
if (c == 'x' || c == 'X') {
--p;
(void)ungetc(c, fp);
}
if ((flags & SUPPRESS) == 0) {
uintmax_t res;
*p = '\0';
if (flags & UNSIGNED) {
res = strtoumax(buf, nullptr, base);
} else {
res = strtoimax(buf, nullptr, base);
}
if (flags & POINTER) {
*va_arg(ap, void**) = (void*)(uintptr_t)res;
} else if (flags & MAXINT) {
*va_arg(ap, intmax_t*) = res;
} else if (flags & LLONG) {
*va_arg(ap, long long*) = res;
} else if (flags & SIZEINT) {
*va_arg(ap, ssize_t*) = res;
} else if (flags & PTRINT) {
*va_arg(ap, ptrdiff_t*) = res;
} else if (flags & LONG) {
*va_arg(ap, long*) = res;
} else if (flags & SHORT) {
*va_arg(ap, short*) = res;
} else if (flags & SHORTSHORT) {
*va_arg(ap, signed char*) = res;
} else {
*va_arg(ap, int*) = res;
}
nassigned++;
}
nread += p - buf;
break;
case CT_FLOAT:
/* scan a floating point number as if by strtod */
if (width == 0 || width > sizeof(buf) - 1) width = sizeof(buf) - 1;
if ((width = parsefloat(fp, buf, buf + width)) == 0) goto match_failure;
if ((flags & SUPPRESS) == 0) {
if (flags & LONGDBL) {
long double res = strtold(buf, &p);
*va_arg(ap, long double*) = res;
} else if (flags & LONG) {
double res = strtod(buf, &p);
*va_arg(ap, double*) = res;
} else {
float res = strtof(buf, &p);
*va_arg(ap, float*) = res;
}
if ((size_t)(p - buf) != width) abort();
nassigned++;
}
nread += width;
break;
}
}
allocation_failure:
input_failure:
free(allocation);
if (nassigned == 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 unsigned char* __sccl(char* tab, const unsigned 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 */
}
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 considerd
* 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++;
do { /* fill in the range */
tab[++c] = v;
} while (c < n);
#if 1 /* XXX another disgusting compatibility hack */
/*
* 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;
#else
c = *fmt++;
if (c == 0) return (fmt - 1);
if (c == ']') return (fmt);
#endif
break;
case ']': /* end of scanset */
return fmt;
default: /* just another character */
c = n;
break;
}
}
/* NOTREACHED */
}