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         { ONF_EXP_NBLNCTU,           "Network Benchmarking Lab, NCTU"                  },
  68         { ONF_EXP_MPCE,              "Mobile Packet Core Extensions"                   },
  69         { ONF_EXP_MPLSTPSPTN,        "MPLS-TP OpenFlow Extensions for SPTN"            },
  70         { 0, NULL }
  71 };
  72
  73 const char *
  74 of_vendor_name(const uint32_t vendor)
  75 {
  76         const struct tok *table = (vendor & 0xff000000) == 0 ? oui_values : onf_exp_str;
  77         return tok2str(table, "unknown", vendor);
  78 }
  79
  80 void
  81 of_bitmap_print(netdissect_options *ndo,
  82                 const struct tok *t, const uint32_t v, const uint32_t u)
  83 {
  84         /* Assigned bits? */
  85         if (v & ~u)
  86                 ND_PRINT(" (%s)", bittok2str(t, "", v));
  87         /* Unassigned bits? */
  88         if (v & u)
  89                 ND_PRINT(" (bogus)");
  90 }
  91
  92 void
  93 of_data_print(netdissect_options *ndo,
  94               const u_char *cp, const u_int len)
  95 {
  96         if (len == 0)
  97                 return;
  98         /* data */
  99         ND_PRINT("\n\t data (%u octets)", len);
 100         if (ndo->ndo_vflag >= 2)
 101                 hex_and_ascii_print(ndo, "\n\t  ", cp, len);
 102         else
 103                 ND_TCHECK_LEN(cp, len);
 104 }
 105
 106 static void
 107 of_message_print(netdissect_options *ndo,
 108                  const u_char *cp, uint16_t len,
 109                  const struct of_msgtypeinfo *mti)
 110 {
 111         /*
 112          * Here "cp" and "len" stand for the message part beyond the common
 113          * OpenFlow 1.0 header, if any.
 114          *
 115          * Most message types are longer than just the header, and the length
 116          * constraints may be complex. When possible, validate the constraint
 117          * completely here (REQ_FIXLEN), otherwise check that the message is
 118          * long enough to begin the decoding (REQ_MINLEN) and have the
 119          * type-specific function do any remaining validation.
 120          */
 121
 122         if (!mti)
 123                 goto tcheck_remainder;
 124
 125         if ((mti->req_what == REQ_FIXLEN && len != mti->req_value) ||
 126             (mti->req_what == REQ_MINLEN && len <  mti->req_value))
 127                 goto invalid;
 128
 129         if (!ndo->ndo_vflag || !mti->decoder)
 130                 goto tcheck_remainder;
 131
 132         mti->decoder(ndo, cp, len);
 133         return;
 134
 135 invalid:
 136         nd_print_invalid(ndo);
 137 tcheck_remainder:
 138         ND_TCHECK_LEN(cp, len);
 139 }
 140
 141 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins
 142  * on a message boundary. */
 143 void
 144 openflow_print(netdissect_options *ndo, const u_char *cp, u_int len)
 145 {
 146         ndo->ndo_protocol = "openflow";
 147         ND_PRINT(": OpenFlow");
 148         while (len) {
 149                 /* Print a single OpenFlow message. */
 150                 uint8_t version, type;
 151                 uint16_t length;
 152                 const struct of_msgtypeinfo *mti;
 153
 154                 /* version */
 155                 version = GET_U_1(cp);
 156                 OF_FWD(1);
 157                 ND_PRINT("\n\tversion %s",
 158                          tok2str(ofver_str, "unknown (0x%02x)", version));
 159                 /* type */
 160                 if (len < 1)
 161                         goto partial_header;
 162                 type = GET_U_1(cp);
 163                 OF_FWD(1);
 164                 mti =
 165                         version == OF_VER_1_0 ? of10_identify_msgtype(type) :
 166                         version == OF_VER_1_3 ? of13_identify_msgtype(type) :
 167                         NULL;
 168                 if (mti && mti->name)
 169                         ND_PRINT(", type %s", mti->name);
 170                 else
 171                         ND_PRINT(", type unknown (0x%02x)", type);
 172                 /* length */
 173                 if (len < 2)
 174                         goto partial_header;
 175                 length = GET_BE_U_2(cp);
 176                 OF_FWD(2);
 177                 ND_PRINT(", length %u%s", length,
 178                          length < OF_HEADER_FIXLEN ? " (too short!)" : "");
 179                 /* xid */
 180                 if (len < 4)
 181                         goto partial_header;
 182                 ND_PRINT(", xid 0x%08x", GET_BE_U_4(cp));
 183                 OF_FWD(4);
 184
 185                 /*
 186                  * When a TCP packet can contain several protocol messages,
 187                  * and at the same time a protocol message can span several
 188                  * TCP packets, decoding an incomplete message at the end of
 189                  * a TCP packet requires attention to detail in this loop.
 190                  *
 191                  * Message length includes the header length and a message
 192                  * always includes the basic header. A message length underrun
 193                  * fails decoding of the rest of the current packet. At the
 194                  * same time, try decoding as much of the current message as
 195                  * possible even when it does not end within the current TCP
 196                  * segment.
 197                  *
 198                  * Specifically, to try to process the message body in this
 199                  * iteration do NOT require the header "length" to be small
 200                  * enough for the full declared OpenFlow message to fit into
 201                  * the remainder of the declared TCP segment, same as the full
 202                  * declared TCP segment is not required to fit into the
 203                  * captured packet buffer.
 204                  *
 205                  * But DO require the same at the end of this iteration to
 206                  * decrement "len" and to proceed to the next iteration.
 207                  * (Ideally the declared TCP payload end will be at or after
 208                  * the captured packet buffer end, but stay safe even when
 209                  * that's somehow not the case.)
 210                  */
 211                 if (length < OF_HEADER_FIXLEN)
 212                         goto invalid;
 213
 214                 of_message_print(ndo, cp, length - OF_HEADER_FIXLEN, mti);
 215                 if (length - OF_HEADER_FIXLEN > len)
 216                         break;
 217                 OF_FWD(length - OF_HEADER_FIXLEN);
 218         } /* while (len) */
 219         return;
 220
 221 partial_header:
 222         ND_PRINT(" (end of TCP payload)");
 223         ND_TCHECK_LEN(cp, len);
 224         return;
 225 invalid: /* fail the current packet */
 226         nd_print_invalid(ndo);
 227         ND_TCHECK_LEN(cp, len);
 228 }