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/*
* Copyright (c) Christos Zoulas 2003.
* All Rights Reserved.
*
* 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 immediately at the beginning of the file, without modification,
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 "file.h"
#ifndef lint
FILE_RCSID("@(#)$File: funcs.c,v 1.89 2016/03/21 15:56:53 christos Exp $")
#endif /* lint */
#include "magic.h"
#include <assert.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#if defined(HAVE_WCHAR_H)
#include <wchar.h>
#endif
#if defined(HAVE_WCTYPE_H)
#include <wctype.h>
#endif
#if defined(HAVE_LIMITS_H)
#include <limits.h>
#endif
#ifndef SIZE_MAX
#define SIZE_MAX ((size_t)~0)
#endif
/*
* Like printf, only we append to a buffer.
*/
protected int
file_vprintf(struct magic_set *ms, const char *fmt, va_list ap)
{
int len;
char *buf, *newstr;
if (ms->event_flags & EVENT_HAD_ERR)
return 0;
len = vasprintf(&buf, fmt, ap);
if (len < 0)
goto out;
if (ms->o.buf != NULL) {
len = asprintf(&newstr, "%s%s", ms->o.buf, buf);
free(buf);
if (len < 0)
goto out;
free(ms->o.buf);
buf = newstr;
}
ms->o.buf = buf;
return 0;
out:
file_error(ms, errno, "vasprintf failed");
return -1;
}
protected int
file_printf(struct magic_set *ms, const char *fmt, ...)
{
int rv;
va_list ap;
va_start(ap, fmt);
rv = file_vprintf(ms, fmt, ap);
va_end(ap);
return rv;
}
/*
* error - print best error message possible
*/
/*VARARGS*/
__attribute__((__format__(__printf__, 3, 0)))
private void
file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
size_t lineno)
{
/* Only the first error is ok */
if (ms->event_flags & EVENT_HAD_ERR)
return;
if (lineno != 0) {
free(ms->o.buf);
ms->o.buf = NULL;
file_printf(ms, "line %" SIZE_T_FORMAT "u:", lineno);
}
if (ms->o.buf && *ms->o.buf)
file_printf(ms, " ");
file_vprintf(ms, f, va);
if (error > 0)
file_printf(ms, " (%s)", strerror(error));
ms->event_flags |= EVENT_HAD_ERR;
ms->error = error;
}
/*VARARGS*/
protected void
file_error(struct magic_set *ms, int error, const char *f, ...)
{
va_list va;
va_start(va, f);
file_error_core(ms, error, f, va, 0);
va_end(va);
}
/*
* Print an error with magic line number.
*/
/*VARARGS*/
protected void
file_magerror(struct magic_set *ms, const char *f, ...)
{
va_list va;
va_start(va, f);
file_error_core(ms, 0, f, va, ms->line);
va_end(va);
}
protected void
file_oomem(struct magic_set *ms, size_t len)
{
file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes",
len);
}
protected void
file_badseek(struct magic_set *ms)
{
file_error(ms, errno, "error seeking");
}
protected void
file_badread(struct magic_set *ms)
{
file_error(ms, errno, "error reading");
}
#ifndef COMPILE_ONLY
static int
checkdone(struct magic_set *ms, int *rv)
{
if ((ms->flags & MAGIC_CONTINUE) == 0)
return 1;
if (file_printf(ms, "\n- ") == -1)
*rv = -1;
return 0;
}
/*ARGSUSED*/
protected int
file_buffer(struct magic_set *ms, int fd, const char *inname __attribute__ ((__unused__)),
const void *buf, size_t nb)
{
int m = 0, rv = 0, looks_text = 0;
const unsigned char *ubuf = CAST(const unsigned char *, buf);
unichar *u8buf = NULL;
size_t ulen;
const char *code = NULL;
const char *code_mime = "binary";
const char *type = "application/octet-stream";
const char *def = "data";
const char *ftype = NULL;
if (nb == 0) {
def = "empty";
type = "application/x-empty";
goto simple;
} else if (nb == 1) {
def = "very short file (no magic)";
goto simple;
}
if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
looks_text = file_encoding(ms, ubuf, nb, &u8buf, &ulen,
&code, &code_mime, &ftype);
}
#ifdef __EMX__
if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
m = file_os2_apptype(ms, inname, buf, nb);
if ((ms->flags & MAGIC_DEBUG) != 0)
(void)fprintf(stderr, "[try os2_apptype %d]\n", m);
switch (m) {
case -1:
return -1;
case 0:
break;
default:
return 1;
}
}
#endif
#if HAVE_FORK
/* try compression stuff */
if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) {
m = file_zmagic(ms, fd, inname, ubuf, nb);
if ((ms->flags & MAGIC_DEBUG) != 0)
(void)fprintf(stderr, "[try zmagic %d]\n", m);
if (m) {
goto done_encoding;
}
}
#endif
/* Check if we have a tar file */
if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) {
m = file_is_tar(ms, ubuf, nb);
if ((ms->flags & MAGIC_DEBUG) != 0)
(void)fprintf(stderr, "[try tar %d]\n", m);
if (m) {
if (checkdone(ms, &rv))
goto done;
}
}
/* Check if we have a CDF file */
if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) {
m = file_trycdf(ms, fd, ubuf, nb);
if ((ms->flags & MAGIC_DEBUG) != 0)
(void)fprintf(stderr, "[try cdf %d]\n", m);
if (m) {
if (checkdone(ms, &rv))
goto done;
}
}
/* try soft magic tests */
if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0)
m = file_softmagic(ms, ubuf, nb, NULL, NULL, BINTEST,
looks_text);
if ((ms->flags & MAGIC_DEBUG) != 0)
(void)fprintf(stderr, "[try softmagic %d]\n", m);
if (m) {
#ifdef BUILTIN_ELF
if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 &&
nb > 5 && fd != -1) {
/*
* We matched something in the file, so this
* *might* be an ELF file, and the file is at
* least 5 bytes long, so if it's an ELF file
* it has at least one byte past the ELF magic
* number - try extracting information from the
* ELF headers that cannot easily * be
* extracted with rules in the magic file.
*/
m = file_tryelf(ms, fd, ubuf, nb);
if ((ms->flags & MAGIC_DEBUG) != 0)
(void)fprintf(stderr, "[try elf %d]\n",
m);
}
#endif
if (checkdone(ms, &rv))
goto done;
}
/* try text properties */
if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
m = file_ascmagic(ms, ubuf, nb, looks_text);
if ((ms->flags & MAGIC_DEBUG) != 0)
(void)fprintf(stderr, "[try ascmagic %d]\n", m);
if (m) {
if (checkdone(ms, &rv))
goto done;
}
}
simple:
/* give up */
m = 1;
if (ms->flags & MAGIC_MIME) {
if ((ms->flags & MAGIC_MIME_TYPE) &&
file_printf(ms, "%s", type) == -1)
rv = -1;
} else if (ms->flags & MAGIC_APPLE) {
if (file_printf(ms, "UNKNUNKN") == -1)
rv = -1;
} else if (ms->flags & MAGIC_EXTENSION) {
if (file_printf(ms, "???") == -1)
rv = -1;
} else {
if (file_printf(ms, "%s", def) == -1)
rv = -1;
}
done:
if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
if (ms->flags & MAGIC_MIME_TYPE)
if (file_printf(ms, "; charset=") == -1)
rv = -1;
if (file_printf(ms, "%s", code_mime) == -1)
rv = -1;
}
#if HAVE_FORK
done_encoding:
#endif
free(u8buf);
if (rv)
return rv;
return m;
}
#endif
protected int
file_reset(struct magic_set *ms)
{
if (ms->mlist[0] == NULL) {
file_error(ms, 0, "no magic files loaded");
return -1;
}
if (ms->o.buf) {
free(ms->o.buf);
ms->o.buf = NULL;
}
if (ms->o.pbuf) {
free(ms->o.pbuf);
ms->o.pbuf = NULL;
}
ms->event_flags &= ~EVENT_HAD_ERR;
ms->error = -1;
return 0;
}
#define OCTALIFY(n, o) \
/*LINTED*/ \
(void)(*(n)++ = '\\', \
*(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \
*(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \
*(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \
(o)++)
protected const char *
file_getbuffer(struct magic_set *ms)
{
char *pbuf, *op, *np;
size_t psize, len;
if (ms->event_flags & EVENT_HAD_ERR)
return NULL;
if (ms->flags & MAGIC_RAW)
return ms->o.buf;
if (ms->o.buf == NULL)
return NULL;
/* * 4 is for octal representation, + 1 is for NUL */
len = strlen(ms->o.buf);
if (len > (SIZE_MAX - 1) / 4) {
file_oomem(ms, len);
return NULL;
}
psize = len * 4 + 1;
if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
file_oomem(ms, psize);
return NULL;
}
ms->o.pbuf = pbuf;
#if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
{
mbstate_t state;
wchar_t nextchar;
int mb_conv = 1;
size_t bytesconsumed;
char *eop;
(void)memset(&state, 0, sizeof(mbstate_t));
np = ms->o.pbuf;
op = ms->o.buf;
eop = op + len;
while (op < eop) {
bytesconsumed = mbrtowc(&nextchar, op,
(size_t)(eop - op), &state);
if (bytesconsumed == (size_t)(-1) ||
bytesconsumed == (size_t)(-2)) {
mb_conv = 0;
break;
}
if (iswprint(nextchar)) {
(void)memcpy(np, op, bytesconsumed);
op += bytesconsumed;
np += bytesconsumed;
} else {
while (bytesconsumed-- > 0)
OCTALIFY(np, op);
}
}
*np = '\0';
/* Parsing succeeded as a multi-byte sequence */
if (mb_conv != 0)
return ms->o.pbuf;
}
#endif
for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
if (isprint((unsigned char)*op)) {
*np++ = *op++;
} else {
OCTALIFY(np, op);
}
}
*np = '\0';
return ms->o.pbuf;
}
protected int
file_check_mem(struct magic_set *ms, unsigned int level)
{
size_t len;
if (level >= ms->c.len) {
len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
malloc(len) :
realloc(ms->c.li, len));
if (ms->c.li == NULL) {
file_oomem(ms, len);
return -1;
}
}
ms->c.li[level].got_match = 0;
#ifdef ENABLE_CONDITIONALS
ms->c.li[level].last_match = 0;
ms->c.li[level].last_cond = COND_NONE;
#endif /* ENABLE_CONDITIONALS */
return 0;
}
protected size_t
file_printedlen(const struct magic_set *ms)
{
return ms->o.buf == NULL ? 0 : strlen(ms->o.buf);
}
protected int
file_replace(struct magic_set *ms, const char *pat, const char *rep)
{
file_regex_t rx;
int rc, rv = -1;
rc = file_regcomp(&rx, pat, REG_EXTENDED);
if (rc) {
file_regerror(&rx, rc, ms);
} else {
regmatch_t rm;
int nm = 0;
while (file_regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) {
ms->o.buf[rm.rm_so] = '\0';
if (file_printf(ms, "%s%s", rep,
rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
goto out;
nm++;
}
rv = nm;
}
out:
file_regfree(&rx);
return rv;
}
protected int
file_regcomp(file_regex_t *rx, const char *pat, int flags)
{
#ifdef USE_C_LOCALE
rx->c_lc_ctype = newlocale(LC_CTYPE_MASK, "C", 0);
assert(rx->c_lc_ctype != NULL);
rx->old_lc_ctype = uselocale(rx->c_lc_ctype);
assert(rx->old_lc_ctype != NULL);
#else
rx->old_lc_ctype = setlocale(LC_CTYPE, "C");
#endif
rx->pat = pat;
return rx->rc = regcomp(&rx->rx, pat, flags);
}
protected int
file_regexec(file_regex_t *rx, const char *str, size_t nmatch,
regmatch_t* pmatch, int eflags)
{
assert(rx->rc == 0);
return regexec(&rx->rx, str, nmatch, pmatch, eflags);
}
protected void
file_regfree(file_regex_t *rx)
{
if (rx->rc == 0)
regfree(&rx->rx);
#ifdef USE_C_LOCALE
(void)uselocale(rx->old_lc_ctype);
freelocale(rx->c_lc_ctype);
#else
(void)setlocale(LC_CTYPE, rx->old_lc_ctype);
#endif
}
protected void
file_regerror(file_regex_t *rx, int rc, struct magic_set *ms)
{
char errmsg[512];
(void)regerror(rc, &rx->rx, errmsg, sizeof(errmsg));
file_magerror(ms, "regex error %d for `%s', (%s)", rc, rx->pat,
errmsg);
}
protected file_pushbuf_t *
file_push_buffer(struct magic_set *ms)
{
file_pushbuf_t *pb;
if (ms->event_flags & EVENT_HAD_ERR)
return NULL;
if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
return NULL;
pb->buf = ms->o.buf;
pb->offset = ms->offset;
ms->o.buf = NULL;
ms->offset = 0;
return pb;
}
protected char *
file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
{
char *rbuf;
if (ms->event_flags & EVENT_HAD_ERR) {
free(pb->buf);
free(pb);
return NULL;
}
rbuf = ms->o.buf;
ms->o.buf = pb->buf;
ms->offset = pb->offset;
free(pb);
return rbuf;
}
/*
* convert string to ascii printable format.
*/
protected char *
file_printable(char *buf, size_t bufsiz, const char *str)
{
char *ptr, *eptr;
const unsigned char *s = (const unsigned char *)str;
for (ptr = buf, eptr = ptr + bufsiz - 1; ptr < eptr && *s; s++) {
if (isprint(*s)) {
*ptr++ = *s;
continue;
}
if (ptr >= eptr - 3)
break;
*ptr++ = '\\';
*ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0';
*ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0';
*ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0';
}
*ptr = '\0';
return buf;
}
|