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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"
- #include "magic.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_T_MAX
- #ifdef __LP64__
- #define SIZE_T_MAX (size_t)0xffffffffffffffffU
- #else
- #define SIZE_T_MAX (size_t)0xffffffffU
- #endif
- #endif
- #ifndef lint
- FILE_RCSID("@(#)$File: funcs.c,v 1.35 2007/12/27 16:35:59 christos Exp $")
- #endif /* lint */
- #ifndef HAVE_VSNPRINTF
- int vsnprintf(char *, size_t, const char *, va_list);
- #endif
- /*
- * Like printf, only we print to a buffer and advance it.
- */
- protected int
- file_printf(struct magic_set *ms, const char *fmt, ...)
- {
- va_list ap;
- size_t size;
- ssize_t len;
- char *buf;
- va_start(ap, fmt);
- len = vsnprintf(ms->o.ptr, ms->o.left, fmt, ap);
- if (len == -1)
- goto out;
- if (len >= (ssize_t)ms->o.left) {
- long diff; /* XXX: really ptrdiff_t */
- va_end(ap);
- size = (ms->o.size - ms->o.left) + len + 1024;
- if ((buf = realloc(ms->o.buf, size)) == NULL) {
- file_oomem(ms, size);
- return -1;
- }
- diff = ms->o.ptr - ms->o.buf;
- ms->o.ptr = buf + diff;
- ms->o.buf = buf;
- ms->o.left = size - diff;
- ms->o.size = size;
- va_start(ap, fmt);
- len = vsnprintf(ms->o.ptr, ms->o.left, fmt, ap);
- if (len == -1)
- goto out;
- }
- va_end(ap);
- ms->o.ptr += len;
- ms->o.left -= len;
- return 0;
- out:
- file_error(ms, errno, "vsnprintf failed");
- return -1;
- }
- /*
- * error - print best error message possible
- */
- /*VARARGS*/
- private void
- file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
- uint32_t lineno)
- {
- size_t len;
- /* Only the first error is ok */
- if (ms->haderr)
- return;
- len = 0;
- if (lineno != 0) {
- (void)snprintf(ms->o.buf, ms->o.size, "line %u: ", lineno);
- len = strlen(ms->o.buf);
- }
- (void)vsnprintf(ms->o.buf + len, ms->o.size - len, f, va);
- if (error > 0) {
- len = strlen(ms->o.buf);
- (void)snprintf(ms->o.buf + len, ms->o.size - len, " (%s)",
- strerror(error));
- }
- ms->haderr++;
- 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 %zu 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
- protected int
- file_buffer(struct magic_set *ms, int fd, const char *inname, const void *buf,
- size_t nb)
- {
- int m;
- int mime = ms->flags & MAGIC_MIME;
- if (nb == 0) {
- if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
- file_printf(ms, mime ? "application/x-empty" :
- "empty") == -1)
- return -1;
- return 1;
- } else if (nb == 1) {
- if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
- file_printf(ms, mime ? "application/octet-stream" :
- "very short file (no magic)") == -1)
- return -1;
- return 1;
- }
- #ifdef __EMX__
- if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
- switch (file_os2_apptype(ms, inname, buf, nb)) {
- case -1:
- return -1;
- case 0:
- break;
- default:
- return 1;
- }
- }
- #endif
- /* try compression stuff */
- if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) != 0 ||
- (m = file_zmagic(ms, fd, inname, buf, nb)) == 0) {
- /* Check if we have a tar file */
- if ((ms->flags & MAGIC_NO_CHECK_TAR) != 0 ||
- (m = file_is_tar(ms, buf, nb)) == 0) {
- /* try tests in /etc/magic (or surrogate magic file) */
- if ((ms->flags & MAGIC_NO_CHECK_SOFT) != 0 ||
- (m = file_softmagic(ms, buf, nb)) == 0) {
- /* try known keywords, check whether it is ASCII */
- if ((ms->flags & MAGIC_NO_CHECK_ASCII) != 0 ||
- (m = file_ascmagic(ms, buf, nb)) == 0) {
- /* abandon hope, all ye who remain here */
- if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
- file_printf(ms, mime ? "application/octet-stream" :
- "data") == -1)
- return -1;
- m = 1;
- }
- }
- }
- }
- #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.
- */
- (void)file_tryelf(ms, fd, buf, nb);
- }
- #endif
- return m;
- }
- #endif
- protected int
- file_reset(struct magic_set *ms)
- {
- if (ms->mlist == NULL) {
- file_error(ms, 0, "no magic files loaded");
- return -1;
- }
- ms->o.ptr = ms->o.buf;
- ms->o.left = ms->o.size;
- ms->haderr = 0;
- 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->haderr)
- return NULL;
- if (ms->flags & MAGIC_RAW)
- return ms->o.buf;
- len = ms->o.size - ms->o.left;
- /* * 4 is for octal representation, + 1 is for NUL */
- if (len > (SIZE_T_MAX - 1) / 4) {
- file_oomem(ms, len);
- return NULL;
- }
- psize = len * 4 + 1;
- if (ms->o.psize < psize) {
- if ((pbuf = realloc(ms->o.pbuf, psize)) == NULL) {
- file_oomem(ms, psize);
- return NULL;
- }
- ms->o.psize = psize;
- 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 + strlen(ms->o.buf);
- 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; 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) * sizeof(*ms->c.li);
- ms->c.li = (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;
- }
- /*
- * Yes these wrappers suffer from buffer overflows, but if your OS does not
- * have the real functions, maybe you should consider replacing your OS?
- */
- #ifndef HAVE_VSNPRINTF
- int
- vsnprintf(char *buf, size_t len, const char *fmt, va_list ap)
- {
- return vsprintf(buf, fmt, ap);
- }
- #endif
- #ifndef HAVE_SNPRINTF
- /*ARGSUSED*/
- int
- snprintf(char *buf, size_t len, const char *fmt, ...)
- {
- int rv;
- va_list ap;
- va_start(ap, fmt);
- rv = vsprintf(buf, fmt, ap);
- va_end(ap);
- return rv;
- }
- #endif
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