The Tcpdump Group git mirrors - tcpdump/blob - print-openflow.c

   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 #define ND_LONGJMP_FROM_TCHECK
  42 #include "netdissect.h"
  43 #include "extract.h"
  44 #include "openflow.h"
  45 #include "oui.h"
  46
  47
  48 #define OF_VER_1_0    0x01
  49 #define OF_VER_1_1    0x02
  50 #define OF_VER_1_2    0x03
  51 #define OF_VER_1_3    0x04
  52 #define OF_VER_1_4    0x05
  53 #define OF_VER_1_5    0x06
  54
  55 static const struct tok ofver_str[] = {
  56         { OF_VER_1_0,   "1.0" },
  57         { OF_VER_1_1,   "1.1" },
  58         { OF_VER_1_2,   "1.2" },
  59         { OF_VER_1_3,   "1.3" },
  60         { OF_VER_1_4,   "1.4" },
  61         { OF_VER_1_5,   "1.5" },
  62         { 0, NULL }
  63 };
  64
  65 const struct tok onf_exp_str[] = {
  66         { ONF_EXP_ONF,               "ONF Extensions"                                  },
  67         { ONF_EXP_BUTE,              "Budapest University of Technology and Economics" },
  68         { ONF_EXP_NOVIFLOW,          "NoviFlow"                                        },
  69         { ONF_EXP_L3,                "L3+ Extensions, Vendor Neutral"                  },
  70         { ONF_EXP_L4L7,              "L4-L7 Extensions"                                },
  71         { ONF_EXP_WMOB,              "Wireless and Mobility Extensions"                },
  72         { ONF_EXP_FABS,              "Forwarding Abstractions Extensions"              },
  73         { ONF_EXP_OTRANS,            "Optical Transport Extensions"                    },
  74         { 0, NULL }
  75 };
  76
  77 const char *
  78 of_vendor_name(const uint32_t vendor)
  79 {
  80         const struct tok *table = (vendor & 0xff000000) == 0 ? oui_values : onf_exp_str;
  81         return tok2str(table, "unknown", vendor);
  82 }
  83
  84 void
  85 of_data_print(netdissect_options *ndo,
  86               const u_char *cp, const u_int len)
  87 {
  88         if (len == 0)
  89                 return;
  90         /* data */
  91         ND_PRINT("\n\t data (%u octets)", len);
  92         if (ndo->ndo_vflag >= 2)
  93                 hex_and_ascii_print(ndo, "\n\t  ", cp, len);
  94         else
  95                 ND_TCHECK_LEN(cp, len);
  96 }
  97
  98 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins
  99  * on a message boundary. */
 100 void
 101 openflow_print(netdissect_options *ndo, const u_char *cp, u_int len)
 102 {
 103         ndo->ndo_protocol = "openflow";
 104         ND_PRINT(": OpenFlow");
 105         while (len) {
 106                 /* Print a single OpenFlow message. */
 107                 uint8_t version, type;
 108                 uint16_t length;
 109                 void (*decoder)(struct netdissect_options *,
 110                                 const u_char *, u_int16_t, const uint8_t) = NULL;
 111
 112                 /* version */
 113                 version = GET_U_1(cp);
 114                 OF_FWD(1);
 115                 ND_PRINT("\n\tversion %s",
 116                          tok2str(ofver_str, "unknown (0x%02x)", version));
 117                 /* type */
 118                 if (len < 1)
 119                         goto partial_header;
 120                 type = GET_U_1(cp);
 121                 OF_FWD(1);
 122                 switch (version) {
 123                 case OF_VER_1_0:
 124                         ND_PRINT(", type %s", of10_msgtype_str(type));
 125                         decoder = of10_message_print;
 126                         break;
 127                 case OF_VER_1_3:
 128                         ND_PRINT(", type %s", of13_msgtype_str(type));
 129                         decoder = of13_message_print;
 130                         break;
 131                 default:
 132                         ND_PRINT(", type unknown (0x%02x)", type);
 133                 }
 134                 /* length */
 135                 if (len < 2)
 136                         goto partial_header;
 137                 length = GET_BE_U_2(cp);
 138                 OF_FWD(2);
 139                 ND_PRINT(", length %u%s", length,
 140                          length < OF_HEADER_FIXLEN ? " (too short!)" : "");
 141                 /* xid */
 142                 if (len < 4)
 143                         goto partial_header;
 144                 ND_PRINT(", xid 0x%08x", GET_BE_U_4(cp));
 145                 OF_FWD(4);
 146
 147                 /*
 148                  * When a TCP packet can contain several protocol messages,
 149                  * and at the same time a protocol message can span several
 150                  * TCP packets, decoding an incomplete message at the end of
 151                  * a TCP packet requires attention to detail in this loop.
 152                  *
 153                  * Message length includes the header length and a message
 154                  * always includes the basic header. A message length underrun
 155                  * fails decoding of the rest of the current packet. At the
 156                  * same time, try decoding as much of the current message as
 157                  * possible even when it does not end within the current TCP
 158                  * segment.
 159                  *
 160                  * Specifically, to try to process the message body in this
 161                  * iteration do NOT require the header "length" to be small
 162                  * enough for the full declared OpenFlow message to fit into
 163                  * the remainder of the declared TCP segment, same as the full
 164                  * declared TCP segment is not required to fit into the
 165                  * captured packet buffer.
 166                  *
 167                  * But DO require the same at the end of this iteration to
 168                  * decrement "len" and to proceed to the next iteration.
 169                  * (Ideally the declared TCP payload end will be at or after
 170                  * the captured packet buffer end, but stay safe even when
 171                  * that's somehow not the case.)
 172                  */
 173                 if (length < OF_HEADER_FIXLEN)
 174                         goto invalid;
 175
 176                 if (decoder != NULL)
 177                         decoder(ndo, cp, length - OF_HEADER_FIXLEN, type);
 178                 else
 179                         ND_TCHECK_LEN(cp, length - OF_HEADER_FIXLEN);
 180                 if (length - OF_HEADER_FIXLEN > len)
 181                         break;
 182                 OF_FWD(length - OF_HEADER_FIXLEN);
 183         } /* while (len) */
 184         return;
 185
 186 partial_header:
 187         ND_PRINT(" (end of TCP payload)");
 188         ND_TCHECK_LEN(cp, len);
 189         return;
 190 invalid: /* fail the current packet */
 191         nd_print_invalid(ndo);
 192         ND_TCHECK_LEN(cp, len);
 193 }