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 #include <sys/cdefs.h> 25 #ifndef lint 26 __RCSID("$NetBSD: print-nsh.c,v 1.3 2017/02/05 04:05:05 spz Exp $"); 27 #endif 28 29 /* \summary: Network Service Header (NSH) printer */ 30 31 /* specification: draft-ietf-sfc-nsh-01 */ 32 33 #ifdef HAVE_CONFIG_H 34 #include "config.h" 35 #endif 36 37 #include <netdissect-stdinc.h> 38 39 #include "netdissect.h" 40 #include "extract.h" 41 42 static const char tstr[] = " [|NSH]"; 43 static const struct tok nsh_flags [] = { 44 { 0x20, "O" }, 45 { 0x10, "C" }, 46 { 0, NULL } 47 }; 48 49 #define NSH_BASE_HDR_LEN 4 50 #define NSH_SERVICE_PATH_HDR_LEN 4 51 #define NSH_HDR_WORD_SIZE 4U 52 53 void 54 nsh_print(netdissect_options *ndo, const u_char *bp, u_int len) 55 { 56 int n, vn; 57 uint8_t ver; 58 uint8_t flags; 59 uint8_t length; 60 uint8_t md_type; 61 uint8_t next_protocol; 62 uint32_t service_path_id; 63 uint8_t service_index; 64 uint32_t ctx; 65 uint16_t tlv_class; 66 uint8_t tlv_type; 67 uint8_t tlv_len; 68 u_int next_len; 69 70 /* print Base Header and Service Path Header */ 71 if (len < NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN) 72 goto trunc; 73 74 ND_TCHECK2(*bp, NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN); 75 76 ver = (uint8_t)(*bp >> 6); 77 flags = *bp; 78 bp += 1; 79 length = *bp; 80 bp += 1; 81 md_type = *bp; 82 bp += 1; 83 next_protocol = *bp; 84 bp += 1; 85 service_path_id = EXTRACT_24BITS(bp); 86 bp += 3; 87 service_index = *bp; 88 bp += 1; 89 90 ND_PRINT((ndo, "NSH, ")); 91 if (ndo->ndo_vflag > 1) { 92 ND_PRINT((ndo, "ver %d, ", ver)); 93 } 94 ND_PRINT((ndo, "flags [%s], ", bittok2str_nosep(nsh_flags, "none", flags))); 95 if (ndo->ndo_vflag > 2) { 96 ND_PRINT((ndo, "length %d, ", length)); 97 ND_PRINT((ndo, "md type 0x%x, ", md_type)); 98 } 99 if (ndo->ndo_vflag > 1) { 100 ND_PRINT((ndo, "next-protocol 0x%x, ", next_protocol)); 101 } 102 ND_PRINT((ndo, "service-path-id 0x%06x, ", service_path_id)); 103 ND_PRINT((ndo, "service-index 0x%x", service_index)); 104 105 /* Make sure we have all the headers */ 106 if (len < length * NSH_HDR_WORD_SIZE) 107 goto trunc; 108 109 ND_TCHECK2(*bp, length * NSH_HDR_WORD_SIZE); 110 111 /* 112 * length includes the lengths of the Base and Service Path headers. 113 * That means it must be at least 2. 114 */ 115 if (length < 2) 116 goto trunc; 117 118 /* 119 * Print, or skip, the Context Headers. 120 * (length - 2) is the length of those headers. 121 */ 122 if (ndo->ndo_vflag > 2) { 123 if (md_type == 0x01) { 124 for (n = 0; n < length - 2; n++) { 125 ctx = EXTRACT_32BITS(bp); 126 bp += NSH_HDR_WORD_SIZE; 127 ND_PRINT((ndo, "\n Context[%02d]: 0x%08x", n, ctx)); 128 } 129 } 130 else if (md_type == 0x02) { 131 n = 0; 132 while (n < length - 2) { 133 tlv_class = EXTRACT_16BITS(bp); 134 bp += 2; 135 tlv_type = *bp; 136 bp += 1; 137 tlv_len = *bp; 138 bp += 1; 139 140 ND_PRINT((ndo, "\n TLV Class %d, Type %d, Len %d", 141 tlv_class, tlv_type, tlv_len)); 142 143 n += 1; 144 145 if (length - 2 < n + tlv_len) { 146 ND_PRINT((ndo, " ERROR: invalid-tlv-length")); 147 return; 148 } 149 150 for (vn = 0; vn < tlv_len; vn++) { 151 ctx = EXTRACT_32BITS(bp); 152 bp += NSH_HDR_WORD_SIZE; 153 ND_PRINT((ndo, "\n Value[%02d]: 0x%08x", vn, ctx)); 154 } 155 n += tlv_len; 156 } 157 } 158 else { 159 ND_PRINT((ndo, "ERROR: unknown-next-protocol")); 160 return; 161 } 162 } 163 else { 164 bp += (length - 2) * NSH_HDR_WORD_SIZE; 165 } 166 ND_PRINT((ndo, ndo->ndo_vflag ? "\n " : ": ")); 167 168 /* print Next Protocol */ 169 next_len = len - length * NSH_HDR_WORD_SIZE; 170 switch (next_protocol) { 171 case 0x1: 172 ip_print(ndo, bp, next_len); 173 break; 174 case 0x2: 175 ip6_print(ndo, bp, next_len); 176 break; 177 case 0x3: 178 ether_print(ndo, bp, next_len, ndo->ndo_snapend - bp, NULL, NULL); 179 break; 180 default: 181 ND_PRINT((ndo, "ERROR: unknown-next-protocol")); 182 return; 183 } 184 185 return; 186 187 trunc: 188 ND_PRINT((ndo, "%s", tstr)); 189 } 190 191