/*- * Copyright (c) 2003, 2004 David Young.  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. * 3. The name of David Young may not be used to endorse or promote *    products derived from this software without specific prior *    written permission. * * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``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 DAVID * YOUNG 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. */#ifdef HAVE_CONFIG_H#include "config.h"#endif#include <stdlib.h>#include <string.h>#include <tcpdump-stdinc.h>#include "cpack.h"#include "extract.h"static u_int8_t *cpack_next_boundary(u_int8_t *buf, u_int8_t *p, size_t alignment){	size_t misalignment = (size_t)(p - buf) % alignment;	if (misalignment == 0)		return p;	return p + (alignment - misalignment);}/* Advance to the next wordsize boundary. Return NULL if fewer than * wordsize bytes remain in the buffer after the boundary.  Otherwise, * return a pointer to the boundary. */static u_int8_t *cpack_align_and_reserve(struct cpack_state *cs, size_t wordsize){	u_int8_t *next;	/* Ensure alignment. */	next = cpack_next_boundary(cs->c_buf, cs->c_next, wordsize);	/* Too little space for wordsize bytes? */	if (next - cs->c_buf + wordsize > cs->c_len)		return NULL;	return next;}intcpack_init(struct cpack_state *cs, u_int8_t *buf, size_t buflen){	memset(cs, 0, sizeof(*cs));	cs->c_buf = buf;	cs->c_len = buflen;	cs->c_next = cs->c_buf;	return 0;}/* Unpack a 64-bit unsigned integer. */intcpack_uint64(struct cpack_state *cs, u_int64_t *u){	u_int8_t *next;	if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)		return -1;	*u = EXTRACT_LE_64BITS(next);	/* Move pointer past the u_int64_t. */	cs->c_next = next + sizeof(*u);	return 0;}/* Unpack a 32-bit unsigned integer. */intcpack_uint32(struct cpack_state *cs, u_int32_t *u){	u_int8_t *next;	if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)		return -1;	*u = EXTRACT_LE_32BITS(next);	/* Move pointer past the u_int32_t. */	cs->c_next = next + sizeof(*u);	return 0;}/* Unpack a 16-bit unsigned integer. */intcpack_uint16(struct cpack_state *cs, u_int16_t *u){	u_int8_t *next;	if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)		return -1;	*u = EXTRACT_LE_16BITS(next);	/* Move pointer past the u_int16_t. */	cs->c_next = next + sizeof(*u);	return 0;}/* Unpack an 8-bit unsigned integer. */intcpack_uint8(struct cpack_state *cs, u_int8_t *u){	/* No space left? */	if ((size_t)(cs->c_next - cs->c_buf) >= cs->c_len)		return -1;	*u = *cs->c_next;	/* Move pointer past the u_int8_t. */	cs->c_next++;	return 0;}