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 #include <config.h> 21 22 #include "netdissect-stdinc.h" 23 24 #define ND_LONGJMP_FROM_TCHECK 25 #include "netdissect.h" 26 #include "extract.h" 27 28 #define OTV_HDR_LEN 8 29 30 /* 31 * OTV header, draft-hasmit-otv-04 32 * 33 * 0 1 2 3 34 * 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 35 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 36 * |R|R|R|R|I|R|R|R| Overlay ID | 37 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 38 * | Instance ID | Reserved | 39 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 40 */ 41 42 void 43 otv_print(netdissect_options *ndo, const u_char *bp, u_int len) 44 { 45 uint8_t flags; 46 47 ndo->ndo_protocol = "otv"; 48 ND_PRINT("OTV, "); 49 if (len < OTV_HDR_LEN) { 50 ND_PRINT("[length %u < %u]", len, OTV_HDR_LEN); 51 goto invalid; 52 } 53 54 flags = GET_U_1(bp); 55 ND_PRINT("flags [%s] (0x%02x), ", flags & 0x08 ? "I" : ".", flags); 56 bp += 1; 57 58 ND_PRINT("overlay %u, ", GET_BE_U_3(bp)); 59 bp += 3; 60 61 ND_PRINT("instance %u\n", GET_BE_U_3(bp)); 62 bp += 3; 63 64 /* Reserved */ 65 ND_TCHECK_1(bp); 66 bp += 1; 67 68 ether_print(ndo, bp, len - OTV_HDR_LEN, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL); 69 return; 70 71 invalid: 72 nd_print_invalid(ndo); 73 ND_TCHECK_LEN(bp, len); 74 } 75