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 static const struct tok ofver_str[] = {
  49         { OF_VER_1_0,   "1.0" },
  50         { OF_VER_1_1,   "1.1" },
  51         { OF_VER_1_2,   "1.2" },
  52         { OF_VER_1_3,   "1.3" },
  53         { OF_VER_1_4,   "1.4" },
  54         { OF_VER_1_5,   "1.5" },
  55         { 0, NULL }
  56 };
  57
  58 const struct tok onf_exp_str[] = {
  59         { ONF_EXP_ONF,               "ONF Extensions"                                  },
  60         { ONF_EXP_BUTE,              "Budapest University of Technology and Economics" },
  61         { ONF_EXP_NOVIFLOW,          "NoviFlow"                                        },
  62         { ONF_EXP_L3,                "L3+ Extensions, Vendor Neutral"                  },
  63         { ONF_EXP_L4L7,              "L4-L7 Extensions"                                },
  64         { ONF_EXP_WMOB,              "Wireless and Mobility Extensions"                },
  65         { ONF_EXP_FABS,              "Forwarding Abstractions Extensions"              },
  66         { ONF_EXP_OTRANS,            "Optical Transport Extensions"                    },
  67         { 0, NULL }
  68 };
  69
  70 const char *
  71 of_vendor_name(const uint32_t vendor)
  72 {
  73         const struct tok *table = (vendor & 0xff000000) == 0 ? oui_values : onf_exp_str;
  74         return tok2str(table, "unknown", vendor);
  75 }
  76
  77 void
  78 of_bitmap_print(netdissect_options *ndo,
  79                 const struct tok *t, const uint32_t v, const uint32_t u)
  80 {
  81         /* Assigned bits? */
  82         if (v & ~u)
  83                 ND_PRINT(" (%s)", bittok2str(t, "", v));
  84         /* Unassigned bits? */
  85         if (v & u)
  86                 ND_PRINT(" (bogus)");
  87 }
  88
  89 void
  90 of_data_print(netdissect_options *ndo,
  91               const u_char *cp, const u_int len)
  92 {
  93         if (len == 0)
  94                 return;
  95         /* data */
  96         ND_PRINT("\n\t data (%u octets)", len);
  97         if (ndo->ndo_vflag >= 2)
  98                 hex_and_ascii_print(ndo, "\n\t  ", cp, len);
  99         else
 100                 ND_TCHECK_LEN(cp, len);
 101 }
 102
 103 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins
 104  * on a message boundary. */
 105 void
 106 openflow_print(netdissect_options *ndo, const u_char *cp, u_int len)
 107 {
 108         ndo->ndo_protocol = "openflow";
 109         ND_PRINT(": OpenFlow");
 110         while (len) {
 111                 /* Print a single OpenFlow message. */
 112                 uint8_t version, type;
 113                 uint16_t length;
 114                 void (*decoder)(struct netdissect_options *,
 115                                 const u_char *, uint16_t, const uint8_t) = NULL;
 116
 117                 /* version */
 118                 version = GET_U_1(cp);
 119                 OF_FWD(1);
 120                 ND_PRINT("\n\tversion %s",
 121                          tok2str(ofver_str, "unknown (0x%02x)", version));
 122                 /* type */
 123                 if (len < 1)
 124                         goto partial_header;
 125                 type = GET_U_1(cp);
 126                 OF_FWD(1);
 127                 switch (version) {
 128                 case OF_VER_1_0:
 129                         ND_PRINT(", type %s", of10_msgtype_str(type));
 130                         decoder = of10_message_print;
 131                         break;
 132                 case OF_VER_1_3:
 133                         ND_PRINT(", type %s", of13_msgtype_str(type));
 134                         decoder = of13_message_print;
 135                         break;
 136                 default:
 137                         ND_PRINT(", type unknown (0x%02x)", type);
 138                 }
 139                 /* length */
 140                 if (len < 2)
 141                         goto partial_header;
 142                 length = GET_BE_U_2(cp);
 143                 OF_FWD(2);
 144                 ND_PRINT(", length %u%s", length,
 145                          length < OF_HEADER_FIXLEN ? " (too short!)" : "");
 146                 /* xid */
 147                 if (len < 4)
 148                         goto partial_header;
 149                 ND_PRINT(", xid 0x%08x", GET_BE_U_4(cp));
 150                 OF_FWD(4);
 151
 152                 /*
 153                  * When a TCP packet can contain several protocol messages,
 154                  * and at the same time a protocol message can span several
 155                  * TCP packets, decoding an incomplete message at the end of
 156                  * a TCP packet requires attention to detail in this loop.
 157                  *
 158                  * Message length includes the header length and a message
 159                  * always includes the basic header. A message length underrun
 160                  * fails decoding of the rest of the current packet. At the
 161                  * same time, try decoding as much of the current message as
 162                  * possible even when it does not end within the current TCP
 163                  * segment.
 164                  *
 165                  * Specifically, to try to process the message body in this
 166                  * iteration do NOT require the header "length" to be small
 167                  * enough for the full declared OpenFlow message to fit into
 168                  * the remainder of the declared TCP segment, same as the full
 169                  * declared TCP segment is not required to fit into the
 170                  * captured packet buffer.
 171                  *
 172                  * But DO require the same at the end of this iteration to
 173                  * decrement "len" and to proceed to the next iteration.
 174                  * (Ideally the declared TCP payload end will be at or after
 175                  * the captured packet buffer end, but stay safe even when
 176                  * that's somehow not the case.)
 177                  */
 178                 if (length < OF_HEADER_FIXLEN)
 179                         goto invalid;
 180
 181                 if (decoder != NULL)
 182                         decoder(ndo, cp, length - OF_HEADER_FIXLEN, type);
 183                 else
 184                         ND_TCHECK_LEN(cp, length - OF_HEADER_FIXLEN);
 185                 if (length - OF_HEADER_FIXLEN > len)
 186                         break;
 187                 OF_FWD(length - OF_HEADER_FIXLEN);
 188         } /* while (len) */
 189         return;
 190
 191 partial_header:
 192         ND_PRINT(" (end of TCP payload)");
 193         ND_TCHECK_LEN(cp, len);
 194         return;
 195 invalid: /* fail the current packet */
 196         nd_print_invalid(ndo);
 197         ND_TCHECK_LEN(cp, len);
 198 }