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- /*-
- * 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 <netdissect-stdinc.h>
- #include "cpack.h"
- #include "extract.h"
- const uint8_t *
- cpack_next_boundary(const uint8_t *buf, const uint8_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.
- */
- const uint8_t *
- cpack_align_and_reserve(struct cpack_state *cs, size_t wordsize)
- {
- const uint8_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;
- }
- /* Advance by N bytes without returning them. */
- int
- cpack_advance(struct cpack_state *cs, const size_t toskip)
- {
- /* No space left? */
- if (cs->c_next - cs->c_buf + toskip > cs->c_len)
- return -1;
- cs->c_next += toskip;
- return 0;
- }
- int
- cpack_init(struct cpack_state *cs, const uint8_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. */
- int
- cpack_uint64(struct cpack_state *cs, uint64_t *u)
- {
- const uint8_t *next;
- if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
- return -1;
- *u = EXTRACT_LE_64BITS(next);
- /* Move pointer past the uint64_t. */
- cs->c_next = next + sizeof(*u);
- return 0;
- }
- /* Unpack a 32-bit unsigned integer. */
- int
- cpack_uint32(struct cpack_state *cs, uint32_t *u)
- {
- const uint8_t *next;
- if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
- return -1;
- *u = EXTRACT_LE_32BITS(next);
- /* Move pointer past the uint32_t. */
- cs->c_next = next + sizeof(*u);
- return 0;
- }
- /* Unpack a 16-bit unsigned integer. */
- int
- cpack_uint16(struct cpack_state *cs, uint16_t *u)
- {
- const uint8_t *next;
- if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
- return -1;
- *u = EXTRACT_LE_16BITS(next);
- /* Move pointer past the uint16_t. */
- cs->c_next = next + sizeof(*u);
- return 0;
- }
- /* Unpack an 8-bit unsigned integer. */
- int
- cpack_uint8(struct cpack_state *cs, uint8_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 uint8_t. */
- cs->c_next++;
- return 0;
- }
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