2 * Copyright (c) 2003, 2004 David Young. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. The name of David Young may not be used to endorse or promote
13 * products derived from this software without specific prior
16 * THIS SOFTWARE IS PROVIDED BY DAVID YOUNG ``AS IS'' AND ANY
17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
18 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
19 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DAVID
20 * YOUNG BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
21 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
22 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
36 #include <tcpdump-stdinc.h>
42 cpack_next_boundary(u_int8_t *buf, u_int8_t *p, size_t alignment)
44 size_t misalignment = (size_t)(p - buf) % alignment;
46 if (misalignment == 0)
49 return p + (alignment - misalignment);
52 /* Advance to the next wordsize boundary. Return NULL if fewer than
53 * wordsize bytes remain in the buffer after the boundary. Otherwise,
54 * return a pointer to the boundary.
57 cpack_align_and_reserve(struct cpack_state *cs, size_t wordsize)
61 /* Ensure alignment. */
62 next = cpack_next_boundary(cs->c_buf, cs->c_next, wordsize);
64 /* Too little space for wordsize bytes? */
65 if (next - cs->c_buf + wordsize > cs->c_len)
72 cpack_init(struct cpack_state *cs, u_int8_t *buf, size_t buflen)
74 memset(cs, 0, sizeof(*cs));
78 cs->c_next = cs->c_buf;
83 /* Unpack a 64-bit unsigned integer. */
85 cpack_uint64(struct cpack_state *cs, u_int64_t *u)
89 if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
92 *u = EXTRACT_LE_64BITS(next);
94 /* Move pointer past the u_int64_t. */
95 cs->c_next = next + sizeof(*u);
99 /* Unpack a 32-bit unsigned integer. */
101 cpack_uint32(struct cpack_state *cs, u_int32_t *u)
105 if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
108 *u = EXTRACT_LE_32BITS(next);
110 /* Move pointer past the u_int32_t. */
111 cs->c_next = next + sizeof(*u);
115 /* Unpack a 16-bit unsigned integer. */
117 cpack_uint16(struct cpack_state *cs, u_int16_t *u)
121 if ((next = cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
124 *u = EXTRACT_LE_16BITS(next);
126 /* Move pointer past the u_int16_t. */
127 cs->c_next = next + sizeof(*u);
131 /* Unpack an 8-bit unsigned integer. */
133 cpack_uint8(struct cpack_state *cs, u_int8_t *u)
136 if ((size_t)(cs->c_next - cs->c_buf) >= cs->c_len)
141 /* Move pointer past the u_int8_t. */