Home | History | Annotate | Download | only in tcpdump 
      1 /*
      2  * Redistribution and use in source and binary forms, with or without
      3  * modification, are permitted provided that: (1) source code
      4  * distributions retain the above copyright notice and this paragraph
      5  * in its entirety, and (2) distributions including binary code include
      6  * the above copyright notice and this paragraph in its entirety in
      7  * the documentation or other materials provided with the distribution.
      8  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
      9  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
     10  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     11  * FOR A PARTICULAR PURPOSE.
     12  *
     13  * Original code by Francesco Fondelli (francesco dot fondelli, gmail dot com)
     14  */
     15 
     16 /* \summary: Overlay Transport Virtualization (OTV) printer */
     17 
     18 /* specification: draft-hasmit-otv-04 */
     19 
     20 #ifdef HAVE_CONFIG_H
     21 #include "config.h"
     22 #endif
     23 
     24 #include <netdissect-stdinc.h>
     25 
     26 #include "netdissect.h"
     27 #include "extract.h"
     28 
     29 /*
     30  * OTV header, draft-hasmit-otv-04
     31  *
     32  *     0                   1                   2                   3
     33  *     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
     34  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     35  *     |R|R|R|R|I|R|R|R|           Overlay ID                          |
     36  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     37  *     |          Instance ID                          | Reserved      |
     38  *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     39  */
     40 
     41 void
     42 otv_print(netdissect_options *ndo, const u_char *bp, u_int len)
     43 {
     44     uint8_t flags;
     45 
     46     ND_PRINT((ndo, "OTV, "));
     47     if (len < 8)
     48         goto trunc;
     49 
     50     ND_TCHECK(*bp);
     51     flags = *bp;
     52     ND_PRINT((ndo, "flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags));
     53     bp += 1;
     54 
     55     ND_TCHECK2(*bp, 3);
     56     ND_PRINT((ndo, "overlay %u, ", EXTRACT_24BITS(bp)));
     57     bp += 3;
     58 
     59     ND_TCHECK2(*bp, 3);
     60     ND_PRINT((ndo, "instance %u\n", EXTRACT_24BITS(bp)));
     61     bp += 3;
     62 
     63     /* Reserved */
     64     ND_TCHECK(*bp);
     65     bp += 1;
     66 
     67     ether_print(ndo, bp, len - 8, ndo->ndo_snapend - bp, NULL, NULL);
     68     return;
     69 
     70 trunc:
     71     ND_PRINT((ndo, " [|OTV]"));
     72 }
     73