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         const char *sep = " (";
  82
  83         if (v == 0)
  84                 return;
  85         /* assigned bits */
  86         for (; t->s != NULL; t++)
  87                 if (v & t->v) {
  88                         ND_PRINT("%s%s", sep, t->s);
  89                         sep = ", ";
  90                 }
  91         /* unassigned bits? */
  92         ND_PRINT((v & u) ? ") (bogus)" : ")");
  93 }
  94
  95 void
  96 of_data_print(netdissect_options *ndo,
  97               const u_char *cp, const u_int len)
  98 {
  99         if (len == 0)
 100                 return;
 101         /* data */
 102         ND_PRINT("\n\t data (%u octets)", len);
 103         if (ndo->ndo_vflag >= 2)
 104                 hex_and_ascii_print(ndo, "\n\t  ", cp, len);
 105         else
 106                 ND_TCHECK_LEN(cp, len);
 107 }
 108
 109 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins
 110  * on a message boundary. */
 111 void
 112 openflow_print(netdissect_options *ndo, const u_char *cp, u_int len)
 113 {
 114         ndo->ndo_protocol = "openflow";
 115         ND_PRINT(": OpenFlow");
 116         while (len) {
 117                 /* Print a single OpenFlow message. */
 118                 uint8_t version, type;
 119                 uint16_t length;
 120                 void (*decoder)(struct netdissect_options *,
 121                                 const u_char *, uint16_t, const uint8_t) = NULL;
 122
 123                 /* version */
 124                 version = GET_U_1(cp);
 125                 OF_FWD(1);
 126                 ND_PRINT("\n\tversion %s",
 127                          tok2str(ofver_str, "unknown (0x%02x)", version));
 128                 /* type */
 129                 if (len < 1)
 130                         goto partial_header;
 131                 type = GET_U_1(cp);
 132                 OF_FWD(1);
 133                 switch (version) {
 134                 case OF_VER_1_0:
 135                         ND_PRINT(", type %s", of10_msgtype_str(type));
 136                         decoder = of10_message_print;
 137                         break;
 138                 case OF_VER_1_3:
 139                         ND_PRINT(", type %s", of13_msgtype_str(type));
 140                         decoder = of13_message_print;
 141                         break;
 142                 default:
 143                         ND_PRINT(", type unknown (0x%02x)", type);
 144                 }
 145                 /* length */
 146                 if (len < 2)
 147                         goto partial_header;
 148                 length = GET_BE_U_2(cp);
 149                 OF_FWD(2);
 150                 ND_PRINT(", length %u%s", length,
 151                          length < OF_HEADER_FIXLEN ? " (too short!)" : "");
 152                 /* xid */
 153                 if (len < 4)
 154                         goto partial_header;
 155                 ND_PRINT(", xid 0x%08x", GET_BE_U_4(cp));
 156                 OF_FWD(4);
 157
 158                 /*
 159                  * When a TCP packet can contain several protocol messages,
 160                  * and at the same time a protocol message can span several
 161                  * TCP packets, decoding an incomplete message at the end of
 162                  * a TCP packet requires attention to detail in this loop.
 163                  *
 164                  * Message length includes the header length and a message
 165                  * always includes the basic header. A message length underrun
 166                  * fails decoding of the rest of the current packet. At the
 167                  * same time, try decoding as much of the current message as
 168                  * possible even when it does not end within the current TCP
 169                  * segment.
 170                  *
 171                  * Specifically, to try to process the message body in this
 172                  * iteration do NOT require the header "length" to be small
 173                  * enough for the full declared OpenFlow message to fit into
 174                  * the remainder of the declared TCP segment, same as the full
 175                  * declared TCP segment is not required to fit into the
 176                  * captured packet buffer.
 177                  *
 178                  * But DO require the same at the end of this iteration to
 179                  * decrement "len" and to proceed to the next iteration.
 180                  * (Ideally the declared TCP payload end will be at or after
 181                  * the captured packet buffer end, but stay safe even when
 182                  * that's somehow not the case.)
 183                  */
 184                 if (length < OF_HEADER_FIXLEN)
 185                         goto invalid;
 186
 187                 if (decoder != NULL)
 188                         decoder(ndo, cp, length - OF_HEADER_FIXLEN, type);
 189                 else
 190                         ND_TCHECK_LEN(cp, length - OF_HEADER_FIXLEN);
 191                 if (length - OF_HEADER_FIXLEN > len)
 192                         break;
 193                 OF_FWD(length - OF_HEADER_FIXLEN);
 194         } /* while (len) */
 195         return;
 196
 197 partial_header:
 198         ND_PRINT(" (end of TCP payload)");
 199         ND_TCHECK_LEN(cp, len);
 200         return;
 201 invalid: /* fail the current packet */
 202         nd_print_invalid(ndo);
 203         ND_TCHECK_LEN(cp, len);
 204 }