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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 #define NETDISSECT_REWORKED
     34 #ifdef HAVE_CONFIG_H
     35 #include "config.h"
     36 #endif
     37 
     38 #include <tcpdump-stdinc.h>
     39 
     40 #include "interface.h"
     41 #include "extract.h"
     42 #include "openflow.h"
     43 #include "oui.h"
     44 
     45 static const char tstr[] = " [|openflow]";
     46 static const char cstr[] = " (corrupt)";
     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 *
     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
     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 *
     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 corrupt;
     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 corrupt;
    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 corrupt: /* fail current packet */
    124 	ND_PRINT((ndo, "%s", cstr));
    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
    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