ext/libelf/libelf_ar_util.c - public/gem5 - Git at Google

 /*-
  * Copyright (c) 2006,2009,2010 Joseph Koshy
  * 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, 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 <assert.h>
 #include <libelf.h>
 #include <stdlib.h>
 #include <string.h>

 #include "_libelf.h"
 #include "_libelf_ar.h"

 ELFTC_VCSID("$Id: libelf_ar_util.c 3174 2015-03-27 17:13:41Z emaste $");

 /*
  * Convert a string bounded by `start' and `start+sz' (exclusive) to a
  * number in the specified base.
  */
 int
 _libelf_ar_get_number(const char *src, size_t sz, unsigned int base,
     size_t *ret)
 {
 	size_t r;
 	unsigned int c, v;
 	const unsigned char *e, *s;

 	assert(base <= 10);

 	s = (const unsigned char *) src;
 	e = s + sz;

 	/* skip leading blanks */
 	for (;s < e && (c = *s) == ' '; s++)
 		;

 	r = 0L;
 	for (;s < e; s++) {
 		if ((c = *s) == ' ')
 			break;
 		if (c < '0' || c > '9')
 			return (0);
 		v = c - '0';
 		if (v >= base)		/* Illegal digit. */
 			break;
 		r *= base;
 		r += v;
 	}

 	*ret = r;

 	return (1);
 }

 /*
  * Return the translated name for an archive member.
  */
 char *
 _libelf_ar_get_translated_name(const struct ar_hdr *arh, Elf *ar)
 {
 	char *s;
 	unsigned char c;
 	size_t len, offset;
 	const unsigned char *buf, *p, *q, *r;
 	const size_t bufsize = sizeof(arh->ar_name);

 	assert(arh != NULL);
 	assert(ar->e_kind == ELF_K_AR);
 	assert((const unsigned char *) arh >= ar->e_rawfile &&
 	    (const unsigned char *) arh < ar->e_rawfile + ar->e_rawsize);

 	buf = (const unsigned char *) arh->ar_name;

 	/*
 	 * Check for extended naming.
 	 *
 	 * If the name matches the pattern "^/[0-9]+", it is an
 	 * SVR4-style extended name.  If the name matches the pattern
 	 * "#1/[0-9]+", the entry uses BSD style extended naming.
 	 */
 	if (buf[0] == '/' && (c = buf[1]) >= '0' && c <= '9') {
 		/*
 		 * The value in field ar_name is a decimal offset into
 		 * the archive string table where the actual name
 		 * resides.
 		 */
 		if (_libelf_ar_get_number((const char *) (buf + 1),
 			bufsize - 1, 10, &offset) == 0) {
 			LIBELF_SET_ERROR(ARCHIVE, 0);
 			return (NULL);
 		}

 		if (offset > ar->e_u.e_ar.e_rawstrtabsz) {
 			LIBELF_SET_ERROR(ARCHIVE, 0);
 			return (NULL);
 		}

 		p = q = ar->e_u.e_ar.e_rawstrtab + offset;
 		r = ar->e_u.e_ar.e_rawstrtab + ar->e_u.e_ar.e_rawstrtabsz;

 		for (; p < r && *p != '/'; p++)
 			;
 		len = (size_t) (p - q + 1); /* space for the trailing NUL */

 		if ((s = malloc(len)) == NULL) {
 			LIBELF_SET_ERROR(RESOURCE, 0);
 			return (NULL);
 		}

 		(void) strncpy(s, (const char *) q, len - 1);
 		s[len - 1] = '\0';

 		return (s);
 	} else if (IS_EXTENDED_BSD_NAME(buf)) {
 		r = buf + LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE;

 		if (_libelf_ar_get_number((const char *) r, bufsize -
 			LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE, 10,
 			&len) == 0) {
 			LIBELF_SET_ERROR(ARCHIVE, 0);
 			return (NULL);
 		}

 		/*
 		 * Allocate space for the file name plus a
 		 * trailing NUL.
 		 */
 		if ((s = malloc(len + 1)) == NULL) {
 			LIBELF_SET_ERROR(RESOURCE, 0);
 			return (NULL);
 		}

 		/*
 		 * The file name follows the archive header.
 		 */
 		q = (const unsigned char *) (arh + 1);

 		(void) strncpy(s, (const char *) q, len);
 		s[len] = '\0';

 		return (s);
 	}

 	/*
 	 * A 'normal' name.
 	 *
 	 * Skip back over trailing blanks from the end of the field.
 	 * In the SVR4 format, a '/' is used as a terminator for
 	 * non-special names.
 	 */
 	for (q = buf + bufsize - 1; q >= buf && *q == ' '; --q)
 		;

 	if (q >= buf) {
 		if (*q == '/') {
 			/*
 			 * SVR4 style names: ignore the trailing
 			 * character '/', but only if the name is not
 			 * one of the special names "/" and "//".
 			 */
 			if (q > buf + 1 ||
 			    (q == (buf + 1) && *buf != '/'))
 				q--;
 		}

 		len = (size_t) (q - buf + 2); /* Space for a trailing NUL. */
 	} else {
 		/* The buffer only had blanks. */
 		buf = (const unsigned char *) "";
 		len = 1;
 	}

 	if ((s = malloc(len)) == NULL) {
 		LIBELF_SET_ERROR(RESOURCE, 0);
 		return (NULL);
 	}

 	(void) strncpy(s, (const char *) buf, len - 1);
 	s[len - 1] = '\0';

 	return (s);
 }

 /*
  * Return the raw name for an archive member, inclusive of any
  * formatting characters.
  */
 char *
 _libelf_ar_get_raw_name(const struct ar_hdr *arh)
 {
 	char *rawname;
 	const size_t namesz = sizeof(arh->ar_name);

 	if ((rawname = malloc(namesz + 1)) == NULL) {
 		LIBELF_SET_ERROR(RESOURCE, 0);
 		return (NULL);
 	}

 	(void) strncpy(rawname, arh->ar_name, namesz);
 	rawname[namesz] = '\0';
 	return (rawname);
 }

 /*
  * Open an 'ar' archive.
  */
 Elf *
 _libelf_ar_open(Elf *e, int reporterror)
 {
 	size_t sz;
 	int scanahead;
 	struct ar_hdr arh;
 	unsigned char *s, *end;

 	_libelf_init_elf(e, ELF_K_AR);

 	e->e_u.e_ar.e_nchildren = 0;
 	e->e_u.e_ar.e_next = (off_t) -1;

 	/*
 	 * Look for special members.
 	 */

 	s = e->e_rawfile + SARMAG;
 	end = e->e_rawfile + e->e_rawsize;

 	assert(e->e_rawsize > 0);

 	/*
 	 * We use heuristics to determine the flavor of the archive we
 	 * are examining.
 	 *
 	 * SVR4 flavor archives use the name "/ " and "// " for
 	 * special members.
 	 *
 	 * In BSD flavor archives the symbol table, if present, is the
 	 * first archive with name "__.SYMDEF".
 	 */

 #define	READ_AR_HEADER(S, ARH, SZ, END)					\
 	do {								\
 		if ((S) + sizeof((ARH)) > (END))			\
 		        goto error;					\
 		(void) memcpy(&(ARH), (S), sizeof((ARH)));		\
 		if ((ARH).ar_fmag[0] != '`' || (ARH).ar_fmag[1] != '\n') \
 			goto error;					\
 		if (_libelf_ar_get_number((char *) (ARH).ar_size,	\
 		    sizeof((ARH).ar_size), 10, &(SZ)) == 0)		\
 			goto error;					\
 	} while (0)

 	READ_AR_HEADER(s, arh, sz, end);

 	/*
 	 * Handle special archive members for the SVR4 format.
 	 */
 	if (arh.ar_name[0] == '/') {
 		if (sz == 0)
 			goto error;

 		e->e_flags |= LIBELF_F_AR_VARIANT_SVR4;

 		scanahead = 0;

 		/*
 		 * The symbol table (file name "/ ") always comes before the
 		 * string table (file name "// ").
 		 */
 		if (arh.ar_name[1] == ' ') {
 			/* "/ " => symbol table. */
 			scanahead = 1;	/* The string table to follow. */

 			s += sizeof(arh);
 			e->e_u.e_ar.e_rawsymtab = s;
 			e->e_u.e_ar.e_rawsymtabsz = sz;

 			sz = LIBELF_ADJUST_AR_SIZE(sz);
 			s += sz;

 		} else if (arh.ar_name[1] == '/' && arh.ar_name[2] == ' ') {
 			/* "// " => string table for long file names. */
 			s += sizeof(arh);
 			e->e_u.e_ar.e_rawstrtab = s;
 			e->e_u.e_ar.e_rawstrtabsz = sz;

 			sz = LIBELF_ADJUST_AR_SIZE(sz);
 			s += sz;
 		}

 		/*
 		 * If the string table hasn't been seen yet, look for
 		 * it in the next member.
 		 */
 		if (scanahead) {
 			READ_AR_HEADER(s, arh, sz, end);

 			/* "// " => string table for long file names. */
 			if (arh.ar_name[0] == '/' && arh.ar_name[1] == '/' &&
 			    arh.ar_name[2] == ' ') {

 				s += sizeof(arh);

 				e->e_u.e_ar.e_rawstrtab = s;
 				e->e_u.e_ar.e_rawstrtabsz = sz;

 				sz = LIBELF_ADJUST_AR_SIZE(sz);
 				s += sz;
 			}
 		}
 	} else if (strncmp(arh.ar_name, LIBELF_AR_BSD_SYMTAB_NAME,
 		sizeof(LIBELF_AR_BSD_SYMTAB_NAME) - 1) == 0) {
 		/*
 		 * BSD style archive symbol table.
 		 */
 		s += sizeof(arh);
 		e->e_u.e_ar.e_rawsymtab = s;
 		e->e_u.e_ar.e_rawsymtabsz = sz;

 		sz = LIBELF_ADJUST_AR_SIZE(sz);
 		s += sz;
 	}

 	/*
 	 * Update the 'next' offset, so that a subsequent elf_begin()
 	 * works as expected.
 	 */
 	e->e_u.e_ar.e_next = (off_t) (s - e->e_rawfile);

 	return (e);

 error:
 	if (!reporterror) {
 		e->e_kind = ELF_K_NONE;
 		return (e);
 	}

 	LIBELF_SET_ERROR(ARCHIVE, 0);
 	return (NULL);
 }
	/*-
	* Copyright (c) 2006,2009,2010 Joseph Koshy
	* 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, 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 <assert.h>
	#include <libelf.h>
	#include <stdlib.h>
	#include <string.h>

	#include "_libelf.h"
	#include "_libelf_ar.h"

	ELFTC_VCSID("$Id: libelf_ar_util.c 3174 2015-03-27 17:13:41Z emaste $");

	/*
	* Convert a string bounded by `start' and `start+sz' (exclusive) to a
	* number in the specified base.
	*/
	int
	_libelf_ar_get_number(const char *src, size_t sz, unsigned int base,
	size_t *ret)
	{
	size_t r;
	unsigned int c, v;
	const unsigned char e, s;

	assert(base <= 10);

	s = (const unsigned char *) src;
	e = s + sz;

	/* skip leading blanks */
	for (;s < e && (c = *s) == ' '; s++)
	;

	r = 0L;
	for (;s < e; s++) {
	if ((c = *s) == ' ')
	break;
	if (c < '0' \|\| c > '9')
	return (0);
	v = c - '0';
	if (v >= base) /* Illegal digit. */
	break;
	r *= base;
	r += v;
	}

	*ret = r;

	return (1);
	}

	/*
	* Return the translated name for an archive member.
	*/
	char *
	_libelf_ar_get_translated_name(const struct ar_hdr arh, Elf ar)
	{
	char *s;
	unsigned char c;
	size_t len, offset;
	const unsigned char buf, p, q, r;
	const size_t bufsize = sizeof(arh->ar_name);

	assert(arh != NULL);
	assert(ar->e_kind == ELF_K_AR);
	assert((const unsigned char *) arh >= ar->e_rawfile &&
	(const unsigned char *) arh < ar->e_rawfile + ar->e_rawsize);

	buf = (const unsigned char *) arh->ar_name;

	/*
	* Check for extended naming.
	*
	* If the name matches the pattern "^/[0-9]+", it is an
	* SVR4-style extended name. If the name matches the pattern
	* "#1/[0-9]+", the entry uses BSD style extended naming.
	*/
	if (buf[0] == '/' && (c = buf[1]) >= '0' && c <= '9') {
	/*
	* The value in field ar_name is a decimal offset into
	* the archive string table where the actual name
	* resides.
	*/
	if (_libelf_ar_get_number((const char *) (buf + 1),
	bufsize - 1, 10, &offset) == 0) {
	LIBELF_SET_ERROR(ARCHIVE, 0);
	return (NULL);
	}

	if (offset > ar->e_u.e_ar.e_rawstrtabsz) {
	LIBELF_SET_ERROR(ARCHIVE, 0);
	return (NULL);
	}

	p = q = ar->e_u.e_ar.e_rawstrtab + offset;
	r = ar->e_u.e_ar.e_rawstrtab + ar->e_u.e_ar.e_rawstrtabsz;

	for (; p < r && *p != '/'; p++)
	;
	len = (size_t) (p - q + 1); /* space for the trailing NUL */

	if ((s = malloc(len)) == NULL) {
	LIBELF_SET_ERROR(RESOURCE, 0);
	return (NULL);
	}

	(void) strncpy(s, (const char *) q, len - 1);
	s[len - 1] = '\0';

	return (s);
	} else if (IS_EXTENDED_BSD_NAME(buf)) {
	r = buf + LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE;

	if (_libelf_ar_get_number((const char *) r, bufsize -
	LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE, 10,
	&len) == 0) {
	LIBELF_SET_ERROR(ARCHIVE, 0);
	return (NULL);
	}

	/*
	* Allocate space for the file name plus a
	* trailing NUL.
	*/
	if ((s = malloc(len + 1)) == NULL) {
	LIBELF_SET_ERROR(RESOURCE, 0);
	return (NULL);
	}

	/*
	* The file name follows the archive header.
	*/
	q = (const unsigned char *) (arh + 1);

	(void) strncpy(s, (const char *) q, len);
	s[len] = '\0';

	return (s);
	}

	/*
	* A 'normal' name.
	*
	* Skip back over trailing blanks from the end of the field.
	* In the SVR4 format, a '/' is used as a terminator for
	* non-special names.
	*/
	for (q = buf + bufsize - 1; q >= buf && *q == ' '; --q)
	;

	if (q >= buf) {
	if (*q == '/') {
	/*
	* SVR4 style names: ignore the trailing
	* character '/', but only if the name is not
	* one of the special names "/" and "//".
	*/
	if (q > buf + 1 \|\|
	(q == (buf + 1) && *buf != '/'))
	q--;
	}

	len = (size_t) (q - buf + 2); /* Space for a trailing NUL. */
	} else {
	/* The buffer only had blanks. */
	buf = (const unsigned char *) "";
	len = 1;
	}

	if ((s = malloc(len)) == NULL) {
	LIBELF_SET_ERROR(RESOURCE, 0);
	return (NULL);
	}

	(void) strncpy(s, (const char *) buf, len - 1);
	s[len - 1] = '\0';

	return (s);
	}

	/*
	* Return the raw name for an archive member, inclusive of any
	* formatting characters.
	*/
	char *
	_libelf_ar_get_raw_name(const struct ar_hdr *arh)
	{
	char *rawname;
	const size_t namesz = sizeof(arh->ar_name);

	if ((rawname = malloc(namesz + 1)) == NULL) {
	LIBELF_SET_ERROR(RESOURCE, 0);
	return (NULL);
	}

	(void) strncpy(rawname, arh->ar_name, namesz);
	rawname[namesz] = '\0';
	return (rawname);
	}

	/*
	* Open an 'ar' archive.
	*/
	Elf *
	_libelf_ar_open(Elf *e, int reporterror)
	{
	size_t sz;
	int scanahead;
	struct ar_hdr arh;
	unsigned char s, end;

	_libelf_init_elf(e, ELF_K_AR);

	e->e_u.e_ar.e_nchildren = 0;
	e->e_u.e_ar.e_next = (off_t) -1;

	/*
	* Look for special members.
	*/

	s = e->e_rawfile + SARMAG;
	end = e->e_rawfile + e->e_rawsize;

	assert(e->e_rawsize > 0);

	/*
	* We use heuristics to determine the flavor of the archive we
	* are examining.
	*
	* SVR4 flavor archives use the name "/ " and "// " for
	* special members.
	*
	* In BSD flavor archives the symbol table, if present, is the
	* first archive with name "__.SYMDEF".
	*/

	#define READ_AR_HEADER(S, ARH, SZ, END) \
	do { \
	if ((S) + sizeof((ARH)) > (END)) \
	goto error; \
	(void) memcpy(&(ARH), (S), sizeof((ARH))); \
	if ((ARH).ar_fmag[0] != '`' \|\| (ARH).ar_fmag[1] != '\n') \
	goto error; \
	if (_libelf_ar_get_number((char *) (ARH).ar_size, \
	sizeof((ARH).ar_size), 10, &(SZ)) == 0) \
	goto error; \
	} while (0)

	READ_AR_HEADER(s, arh, sz, end);

	/*
	* Handle special archive members for the SVR4 format.
	*/
	if (arh.ar_name[0] == '/') {
	if (sz == 0)
	goto error;

	e->e_flags \|= LIBELF_F_AR_VARIANT_SVR4;

	scanahead = 0;

	/*
	* The symbol table (file name "/ ") always comes before the
	* string table (file name "// ").
	*/
	if (arh.ar_name[1] == ' ') {
	/* "/ " => symbol table. */
	scanahead = 1; /* The string table to follow. */

	s += sizeof(arh);
	e->e_u.e_ar.e_rawsymtab = s;
	e->e_u.e_ar.e_rawsymtabsz = sz;

	sz = LIBELF_ADJUST_AR_SIZE(sz);
	s += sz;

	} else if (arh.ar_name[1] == '/' && arh.ar_name[2] == ' ') {
	/* "// " => string table for long file names. */
	s += sizeof(arh);
	e->e_u.e_ar.e_rawstrtab = s;
	e->e_u.e_ar.e_rawstrtabsz = sz;

	sz = LIBELF_ADJUST_AR_SIZE(sz);
	s += sz;
	}

	/*
	* If the string table hasn't been seen yet, look for
	* it in the next member.
	*/
	if (scanahead) {
	READ_AR_HEADER(s, arh, sz, end);

	/* "// " => string table for long file names. */
	if (arh.ar_name[0] == '/' && arh.ar_name[1] == '/' &&
	arh.ar_name[2] == ' ') {

	s += sizeof(arh);

	e->e_u.e_ar.e_rawstrtab = s;
	e->e_u.e_ar.e_rawstrtabsz = sz;

	sz = LIBELF_ADJUST_AR_SIZE(sz);
	s += sz;
	}
	}
	} else if (strncmp(arh.ar_name, LIBELF_AR_BSD_SYMTAB_NAME,
	sizeof(LIBELF_AR_BSD_SYMTAB_NAME) - 1) == 0) {
	/*
	* BSD style archive symbol table.
	*/
	s += sizeof(arh);
	e->e_u.e_ar.e_rawsymtab = s;
	e->e_u.e_ar.e_rawsymtabsz = sz;

	sz = LIBELF_ADJUST_AR_SIZE(sz);
	s += sz;
	}

	/*
	* Update the 'next' offset, so that a subsequent elf_begin()
	* works as expected.
	*/
	e->e_u.e_ar.e_next = (off_t) (s - e->e_rawfile);

	return (e);

	error:
	if (!reporterror) {
	e->e_kind = ELF_K_NONE;
	return (e);
	}

	LIBELF_SET_ERROR(ARCHIVE, 0);
	return (NULL);
	}