1/*
2 * This module implements printing of the very basic (version-independent)
3 * OpenFlow header and iteration over OpenFlow messages. It is intended for
4 * dispatching of version-specific OpenFlow message decoding.
5 *
6 *
7 * Copyright (c) 2013 The TCPDUMP project
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
22 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
23 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
25 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
26 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
27 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
29 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32
33#ifdef HAVE_CONFIG_H
34#include "config.h"
35#endif
36
37#include <tcpdump-stdinc.h>
38
39#include "interface.h"
40#include "extract.h"
41#include "openflow.h"
42
43#define OF_VER_1_0    0x01
44
45static void
46of_header_print(const uint8_t version, const uint8_t type,
47                      const uint16_t length, const uint32_t xid) {
48	printf("\n\tversion unknown (0x%02x), type 0x%02x, length %u, xid 0x%08x",
49	       version, type, length, xid);
50}
51
52/* Print a single OpenFlow message. */
53static const u_char *
54of_header_body_print(const u_char *cp, const u_char *ep) {
55	uint8_t version, type;
56	uint16_t length;
57	uint32_t xid;
58
59	if (ep < cp + OF_HEADER_LEN)
60		goto corrupt;
61	/* version */
62	TCHECK2(*cp, 1);
63	version = *cp;
64	cp += 1;
65	/* type */
66	TCHECK2(*cp, 1);
67	type = *cp;
68	cp += 1;
69	/* length */
70	TCHECK2(*cp, 2);
71	length = EXTRACT_16BITS(cp);
72	cp += 2;
73	/* xid */
74	TCHECK2(*cp, 4);
75	xid = EXTRACT_32BITS(cp);
76	cp += 4;
77	/* Message length includes the header length and a message always includes
78	 * the basic header. A message length underrun fails decoding of the rest of
79	 * the current packet. At the same time, try decoding as much of the current
80	 * message as possible even when it does not end within the current TCP
81	 * segment. */
82	if (length < OF_HEADER_LEN) {
83		of_header_print(version, type, length, xid);
84		goto corrupt;
85	}
86	/* Decode known protocol versions further without printing the header (the
87	 * type decoding is version-specific. */
88	switch (version) {
89	case OF_VER_1_0:
90		return of10_header_body_print(cp, ep, type, length, xid);
91	default:
92		of_header_print(version, type, length, xid);
93		TCHECK2(*cp, length - OF_HEADER_LEN);
94		return cp + length - OF_HEADER_LEN; /* done with current message */
95	}
96
97corrupt: /* fail current packet */
98	printf(" (corrupt)");
99	TCHECK2(*cp, ep - cp);
100	return ep;
101trunc:
102	printf(" [|openflow]");
103	return ep;
104}
105
106/* Print a TCP segment worth of OpenFlow messages presuming the segment begins
107 * on a message boundary. */
108void
109openflow_print(const u_char *cp, const u_int len) {
110	const u_char *ep = cp + len;
111
112	printf(": OpenFlow");
113	while (cp < ep)
114		cp = of_header_body_print(cp, ep);
115}
116