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
45 static void
of_header_print(const uint8_t version,const uint8_t type,const uint16_t length,const uint32_t xid)46 of_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. */
53 static const u_char *
of_header_body_print(const u_char * cp,const u_char * ep)54 of_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
97 corrupt: /* fail current packet */
98 printf(" (corrupt)");
99 TCHECK2(*cp, ep - cp);
100 return ep;
101 trunc:
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. */
108 void
openflow_print(const u_char * cp,const u_int len)109 openflow_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