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diff --git a/cpack.c b/cpack.c
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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 "netdissect.h"
+#include "extract.h"
+
+#include "cpack.h"
+
+const uint8_t *
+nd_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 *
+nd_cpack_align_and_reserve(struct cpack_state *cs, size_t wordsize)
+{
+ const uint8_t *next;
+
+ /* Ensure alignment. */
+ next = nd_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
+nd_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
+nd_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
+nd_cpack_uint64(netdissect_options *ndo, struct cpack_state *cs, uint64_t *u)
+{
+ const uint8_t *next;
+
+ if ((next = nd_cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
+ return -1;
+
+ *u = GET_LE_U_8(next);
+
+ /* Move pointer past the uint64_t. */
+ cs->c_next = next + sizeof(*u);
+ return 0;
+}
+
+/* Unpack a 64-bit signed integer. */
+int
+nd_cpack_int64(netdissect_options *ndo, struct cpack_state *cs, int64_t *u)
+{
+ const uint8_t *next;
+
+ if ((next = nd_cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
+ return -1;
+
+ *u = GET_LE_S_8(next);
+
+ /* Move pointer past the int64_t. */
+ cs->c_next = next + sizeof(*u);
+ return 0;
+}
+
+/* Unpack a 32-bit unsigned integer. */
+int
+nd_cpack_uint32(netdissect_options *ndo, struct cpack_state *cs, uint32_t *u)
+{
+ const uint8_t *next;
+
+ if ((next = nd_cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
+ return -1;
+
+ *u = GET_LE_U_4(next);
+
+ /* Move pointer past the uint32_t. */
+ cs->c_next = next + sizeof(*u);
+ return 0;
+}
+
+/* Unpack a 32-bit signed integer. */
+int
+nd_cpack_int32(netdissect_options *ndo, struct cpack_state *cs, int32_t *u)
+{
+ const uint8_t *next;
+
+ if ((next = nd_cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
+ return -1;
+
+ *u = GET_LE_S_4(next);
+
+ /* Move pointer past the int32_t. */
+ cs->c_next = next + sizeof(*u);
+ return 0;
+}
+
+/* Unpack a 16-bit unsigned integer. */
+int
+nd_cpack_uint16(netdissect_options *ndo, struct cpack_state *cs, uint16_t *u)
+{
+ const uint8_t *next;
+
+ if ((next = nd_cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
+ return -1;
+
+ *u = GET_LE_U_2(next);
+
+ /* Move pointer past the uint16_t. */
+ cs->c_next = next + sizeof(*u);
+ return 0;
+}
+
+/* Unpack a 16-bit signed integer. */
+int
+nd_cpack_int16(netdissect_options *ndo, struct cpack_state *cs, int16_t *u)
+{
+ const uint8_t *next;
+
+ if ((next = nd_cpack_align_and_reserve(cs, sizeof(*u))) == NULL)
+ return -1;
+
+ *u = GET_LE_S_2(next);
+
+ /* Move pointer past the int16_t. */
+ cs->c_next = next + sizeof(*u);
+ return 0;
+}
+
+/* Unpack an 8-bit unsigned integer. */
+int
+nd_cpack_uint8(netdissect_options *ndo, 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 = GET_U_1(cs->c_next);
+
+ /* Move pointer past the uint8_t. */
+ cs->c_next++;
+ return 0;
+}
+
+/* Unpack an 8-bit signed integer. */
+int
+nd_cpack_int8(netdissect_options *ndo, struct cpack_state *cs, int8_t *u)
+{
+ /* No space left? */
+ if ((size_t)(cs->c_next - cs->c_buf) >= cs->c_len)
+ return -1;
+
+ *u = GET_S_1(cs->c_next);
+
+ /* Move pointer past the int8_t. */
+ cs->c_next++;
+ return 0;
+}