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 #include <config.h>
  36
  37 #include "netdissect-stdinc.h"
  38
  39 #define ND_LONGJMP_FROM_TCHECK
  40 #include "netdissect.h"
  41 #include "extract.h"
  42 #include "openflow.h"
  43 #include "oui.h"
  44
  45
  46 static const struct tok ofver_str[] = {
  47         { OF_VER_1_0,   "1.0" },
  48         { OF_VER_1_1,   "1.1" },
  49         { OF_VER_1_2,   "1.2" },
  50         { OF_VER_1_3,   "1.3" },
  51         { OF_VER_1_4,   "1.4" },
  52         { OF_VER_1_5,   "1.5" },
  53         { 0, NULL }
  54 };
  55
  56 const struct tok onf_exp_str[] = {
  57         { ONF_EXP_ONF,               "ONF Extensions"                                  },
  58         { ONF_EXP_BUTE,              "Budapest University of Technology and Economics" },
  59         { ONF_EXP_NOVIFLOW,          "NoviFlow"                                        },
  60         { ONF_EXP_L3,                "L3+ Extensions, Vendor Neutral"                  },
  61         { ONF_EXP_L4L7,              "L4-L7 Extensions"                                },
  62         { ONF_EXP_WMOB,              "Wireless and Mobility Extensions"                },
  63         { ONF_EXP_FABS,              "Forwarding Abstractions Extensions"              },
  64         { ONF_EXP_OTRANS,            "Optical Transport Extensions"                    },
  65         { ONF_EXP_NBLNCTU,           "Network Benchmarking Lab, NCTU"                  },
  66         { ONF_EXP_MPCE,              "Mobile Packet Core Extensions"                   },
  67         { ONF_EXP_MPLSTPSPTN,        "MPLS-TP OpenFlow Extensions for SPTN"            },
  68         { 0, NULL }
  69 };
  70
  71 const char *
  72 of_vendor_name(const uint32_t vendor)
  73 {
  74         const struct tok *table = (vendor & 0xff000000) == 0 ? oui_values : onf_exp_str;
  75         return tok2str(table, "unknown", vendor);
  76 }
  77
  78 void
  79 of_bitmap_print(netdissect_options *ndo,
  80                 const struct tok *t, const uint32_t v, const uint32_t u)
  81 {
  82         /* Assigned bits? */
  83         if (v & ~u)
  84                 ND_PRINT(" (%s)", bittok2str(t, "", v));
  85         /* Unassigned bits? */
  86         if (v & u)
  87                 ND_PRINT(" (bogus)");
  88 }
  89
  90 void
  91 of_data_print(netdissect_options *ndo,
  92               const u_char *cp, const u_int len)
  93 {
  94         if (len == 0)
  95                 return;
  96         /* data */
  97         ND_PRINT("\n\t data (%u octets)", len);
  98         if (ndo->ndo_vflag >= 2)
  99                 hex_and_ascii_print(ndo, "\n\t  ", cp, len);
 100         else
 101                 ND_TCHECK_LEN(cp, len);
 102 }
 103
 104 static void
 105 of_message_print(netdissect_options *ndo,
 106                  const u_char *cp, uint16_t len,
 107                  const struct of_msgtypeinfo *mti)
 108 {
 109         /*
 110          * Here "cp" and "len" stand for the message part beyond the common
 111          * OpenFlow 1.0 header, if any.
 112          *
 113          * Most message types are longer than just the header, and the length
 114          * constraints may be complex. When possible, validate the constraint
 115          * completely here (REQ_FIXLEN), otherwise check that the message is
 116          * long enough to begin the decoding (REQ_MINLEN) and have the
 117          * type-specific function do any remaining validation.
 118          */
 119
 120         if (!mti)
 121                 goto tcheck_remainder;
 122
 123         if ((mti->req_what == REQ_FIXLEN && len != mti->req_value) ||
 124             (mti->req_what == REQ_MINLEN && len <  mti->req_value))
 125                 goto invalid;
 126
 127         if (!ndo->ndo_vflag || !mti->decoder)
 128                 goto tcheck_remainder;
 129
 130         mti->decoder(ndo, cp, len);
 131         return;
 132
 133 invalid:
 134         nd_print_invalid(ndo);
 135 tcheck_remainder:
 136         ND_TCHECK_LEN(cp, len);
 137 }
 138
 139 /* Print a TCP segment worth of OpenFlow messages presuming the segment begins
 140  * on a message boundary. */
 141 void
 142 openflow_print(netdissect_options *ndo, const u_char *cp, u_int len)
 143 {
 144         ndo->ndo_protocol = "openflow";
 145         ND_PRINT(": OpenFlow");
 146         while (len) {
 147                 /* Print a single OpenFlow message. */
 148                 uint8_t version, type;
 149                 uint16_t length;
 150                 const struct of_msgtypeinfo *mti;
 151
 152                 /* version */
 153                 version = GET_U_1(cp);
 154                 OF_FWD(1);
 155                 ND_PRINT("\n\tversion %s",
 156                          tok2str(ofver_str, "unknown (0x%02x)", version));
 157                 /* type */
 158                 if (len < 1)
 159                         goto partial_header;
 160                 type = GET_U_1(cp);
 161                 OF_FWD(1);
 162                 mti =
 163                         version == OF_VER_1_0 ? of10_identify_msgtype(type) :
 164                         version == OF_VER_1_3 ? of13_identify_msgtype(type) :
 165                         NULL;
 166                 if (mti && mti->name)
 167                         ND_PRINT(", type %s", mti->name);
 168                 else
 169                         ND_PRINT(", type unknown (0x%02x)", type);
 170                 /* length */
 171                 if (len < 2)
 172                         goto partial_header;
 173                 length = GET_BE_U_2(cp);
 174                 OF_FWD(2);
 175                 ND_PRINT(", length %u%s", length,
 176                          length < OF_HEADER_FIXLEN ? " (too short!)" : "");
 177                 /* xid */
 178                 if (len < 4)
 179                         goto partial_header;
 180                 ND_PRINT(", xid 0x%08x", GET_BE_U_4(cp));
 181                 OF_FWD(4);
 182
 183                 /*
 184                  * When a TCP packet can contain several protocol messages,
 185                  * and at the same time a protocol message can span several
 186                  * TCP packets, decoding an incomplete message at the end of
 187                  * a TCP packet requires attention to detail in this loop.
 188                  *
 189                  * Message length includes the header length and a message
 190                  * always includes the basic header. A message length underrun
 191                  * fails decoding of the rest of the current packet. At the
 192                  * same time, try decoding as much of the current message as
 193                  * possible even when it does not end within the current TCP
 194                  * segment.
 195                  *
 196                  * Specifically, to try to process the message body in this
 197                  * iteration do NOT require the header "length" to be small
 198                  * enough for the full declared OpenFlow message to fit into
 199                  * the remainder of the declared TCP segment, same as the full
 200                  * declared TCP segment is not required to fit into the
 201                  * captured packet buffer.
 202                  *
 203                  * But DO require the same at the end of this iteration to
 204                  * decrement "len" and to proceed to the next iteration.
 205                  * (Ideally the declared TCP payload end will be at or after
 206                  * the captured packet buffer end, but stay safe even when
 207                  * that's somehow not the case.)
 208                  */
 209                 if (length < OF_HEADER_FIXLEN)
 210                         goto invalid;
 211
 212                 of_message_print(ndo, cp, length - OF_HEADER_FIXLEN, mti);
 213                 if (length - OF_HEADER_FIXLEN > len)
 214                         break;
 215                 OF_FWD(length - OF_HEADER_FIXLEN);
 216         } /* while (len) */
 217         return;
 218
 219 partial_header:
 220         ND_PRINT(" (end of TCP payload)");
 221         ND_TCHECK_LEN(cp, len);
 222         return;
 223 invalid: /* fail the current packet */
 224         nd_print_invalid(ndo);
 225         ND_TCHECK_LEN(cp, len);
 226 }