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