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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 /* \summary: version-independent OpenFlow printer */
34 
35 #ifdef HAVE_CONFIG_H
36 #include "config.h"
37 #endif
38 
39 #include <netdissect-stdinc.h>
40 
41 #include "netdissect.h"
42 #include "extract.h"
43 #include "openflow.h"
44 #include "oui.h"
45 
46 static const char tstr[] = " [|openflow]";
47 
48 #define OF_VER_1_0    0x01
49 
50 const struct tok onf_exp_str[] = {
51 	{ ONF_EXP_ONF,               "ONF Extensions"                                  },
52 	{ ONF_EXP_BUTE,              "Budapest University of Technology and Economics" },
53 	{ ONF_EXP_NOVIFLOW,          "NoviFlow"                                        },
54 	{ ONF_EXP_L3,                "L3+ Extensions, Vendor Neutral"                  },
55 	{ ONF_EXP_L4L7,              "L4-L7 Extensions"                                },
56 	{ ONF_EXP_WMOB,              "Wireless and Mobility Extensions"                },
57 	{ ONF_EXP_FABS,              "Forwarding Abstractions Extensions"              },
58 	{ ONF_EXP_OTRANS,            "Optical Transport Extensions"                    },
59 	{ 0, NULL }
60 };
61 
62 const char *
of_vendor_name(const uint32_t vendor)63 of_vendor_name(const uint32_t vendor)
64 {
65 	const struct tok *table = (vendor & 0xff000000) == 0 ? oui_values : onf_exp_str;
66 	return tok2str(table, "unknown", vendor);
67 }
68 
69 static void
of_header_print(netdissect_options * ndo,const uint8_t version,const uint8_t type,const uint16_t length,const uint32_t xid)70 of_header_print(netdissect_options *ndo, const uint8_t version, const uint8_t type,
71                       const uint16_t length, const uint32_t xid)
72 {
73 	ND_PRINT((ndo, "\n\tversion unknown (0x%02x), type 0x%02x, length %u, xid 0x%08x",
74 	       version, type, length, xid));
75 }
76 
77 /* Print a single OpenFlow message. */
78 static const u_char *
of_header_body_print(netdissect_options * ndo,const u_char * cp,const u_char * ep)79 of_header_body_print(netdissect_options *ndo, const u_char *cp, const u_char *ep)
80 {
81 	uint8_t version, type;
82 	uint16_t length;
83 	uint32_t xid;
84 
85 	if (ep < cp + OF_HEADER_LEN)
86 		goto invalid;
87 	/* version */
88 	ND_TCHECK2(*cp, 1);
89 	version = *cp;
90 	cp += 1;
91 	/* type */
92 	ND_TCHECK2(*cp, 1);
93 	type = *cp;
94 	cp += 1;
95 	/* length */
96 	ND_TCHECK2(*cp, 2);
97 	length = EXTRACT_16BITS(cp);
98 	cp += 2;
99 	/* xid */
100 	ND_TCHECK2(*cp, 4);
101 	xid = EXTRACT_32BITS(cp);
102 	cp += 4;
103 	/* Message length includes the header length and a message always includes
104 	 * the basic header. A message length underrun fails decoding of the rest of
105 	 * the current packet. At the same time, try decoding as much of the current
106 	 * message as possible even when it does not end within the current TCP
107 	 * segment. */
108 	if (length < OF_HEADER_LEN) {
109 		of_header_print(ndo, version, type, length, xid);
110 		goto invalid;
111 	}
112 	/* Decode known protocol versions further without printing the header (the
113 	 * type decoding is version-specific. */
114 	switch (version) {
115 	case OF_VER_1_0:
116 		return of10_header_body_print(ndo, cp, ep, type, length, xid);
117 	default:
118 		of_header_print(ndo, version, type, length, xid);
119 		ND_TCHECK2(*cp, length - OF_HEADER_LEN);
120 		return cp + length - OF_HEADER_LEN; /* done with current message */
121 	}
122 
123 invalid: /* fail current packet */
124 	ND_PRINT((ndo, "%s", istr));
125 	ND_TCHECK2(*cp, ep - cp);
126 	return ep;
127 trunc:
128 	ND_PRINT((ndo, "%s", tstr));
129 	return ep;
130 }
131 
132 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins
133  * on a message boundary. */
134 void
openflow_print(netdissect_options * ndo,const u_char * cp,const u_int len)135 openflow_print(netdissect_options *ndo, const u_char *cp, const u_int len)
136 {
137 	const u_char *ep = cp + len;
138 
139 	ND_PRINT((ndo, ": OpenFlow"));
140 	while (cp < ep)
141 		cp = of_header_body_print(ndo, cp, ep);
142 }
143