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