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      1 /* Copyright (c) 2015, bugyo
      2  * All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are met:
      6  * 1. Redistributions of source code must retain the above copyright notice,
      7  *    this list of conditions and the following disclaimer.
      8  * 2. Redistributions in binary form must reproduce the above copyright notice,
      9  *    this list of conditions and the following disclaimer in the documentation
     10  *    and/or other materials provided with the distribution.
     11  *
     12  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
     13  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     14  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     15  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
     16  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     17  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     18  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     19  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     20  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     21  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     22  */
     23 
     24 /* \summary: Generic Protocol Extension for VXLAN (VXLAN GPE) printer */
     25 
     26 /* specification: draft-ietf-nvo3-vxlan-gpe-01 */
     27 
     28 #ifdef HAVE_CONFIG_H
     29 #include "config.h"
     30 #endif
     31 
     32 #include <netdissect-stdinc.h>
     33 
     34 #include "netdissect.h"
     35 #include "extract.h"
     36 
     37 static const char tstr[] = " [|VXLAN-GPE]";
     38 static const struct tok vxlan_gpe_flags [] = {
     39     { 0x08, "I" },
     40     { 0x04, "P" },
     41     { 0x01, "O" },
     42     { 0, NULL }
     43 };
     44 
     45 #define VXLAN_GPE_HDR_LEN 8
     46 
     47 /*
     48  * VXLAN GPE header, draft-ietf-nvo3-vxlan-gpe-01
     49  *                   Generic Protocol Extension for VXLAN
     50  *
     51  *     0                   1                   2                   3
     52  *     0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
     53  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     54  *    |R|R|Ver|I|P|R|O|       Reserved                |Next Protocol  |
     55  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     56  *    |                VXLAN Network Identifier (VNI) |   Reserved    |
     57  *    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     58  */
     59 
     60 void
     61 vxlan_gpe_print(netdissect_options *ndo, const u_char *bp, u_int len)
     62 {
     63     uint8_t flags;
     64     uint8_t next_protocol;
     65     uint32_t vni;
     66 
     67     if (len < VXLAN_GPE_HDR_LEN)
     68         goto trunc;
     69 
     70     ND_TCHECK2(*bp, VXLAN_GPE_HDR_LEN);
     71 
     72     flags = *bp;
     73     bp += 3;
     74 
     75     next_protocol = *bp;
     76     bp += 1;
     77 
     78     vni = EXTRACT_24BITS(bp);
     79     bp += 4;
     80 
     81     ND_PRINT((ndo, "VXLAN-GPE, "));
     82     ND_PRINT((ndo, "flags [%s], ",
     83               bittok2str_nosep(vxlan_gpe_flags, "none", flags)));
     84     ND_PRINT((ndo, "vni %u", vni));
     85     ND_PRINT((ndo, ndo->ndo_vflag ? "\n    " : ": "));
     86 
     87     switch (next_protocol) {
     88     case 0x1:
     89         ip_print(ndo, bp, len - 8);
     90         break;
     91     case 0x2:
     92         ip6_print(ndo, bp, len - 8);
     93         break;
     94     case 0x3:
     95         ether_print(ndo, bp, len - 8, ndo->ndo_snapend - bp, NULL, NULL);
     96         break;
     97     case 0x4:
     98         nsh_print(ndo, bp, len - 8);
     99         break;
    100     case 0x5:
    101         mpls_print(ndo, bp, len - 8);
    102         break;
    103     default:
    104         ND_PRINT((ndo, "ERROR: unknown-next-protocol"));
    105         return;
    106     }
    107 
    108 	return;
    109 
    110 trunc:
    111 	ND_PRINT((ndo, "%s", tstr));
    112 }
    113 
    114