| /* Copyright (c) 2015, bugyo |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are met: |
| * 1. Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. |
| * 2. Redistributions in binary form must reproduce the above copyright notice, |
| * this list of conditions and the following disclaimer in the documentation |
| * and/or other materials provided with the distribution. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND |
| * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
| * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR |
| * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| /* \summary: Network Service Header (NSH) printer */ |
| |
| /* specification: draft-ietf-sfc-nsh-01 */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif |
| |
| #include "netdissect-stdinc.h" |
| |
| #include "netdissect.h" |
| #include "extract.h" |
| |
| static const struct tok nsh_flags [] = { |
| { 0x20, "O" }, |
| { 0x10, "C" }, |
| { 0, NULL } |
| }; |
| |
| #define NSH_BASE_HDR_LEN 4 |
| #define NSH_SERVICE_PATH_HDR_LEN 4 |
| #define NSH_HDR_WORD_SIZE 4U |
| |
| void |
| nsh_print(netdissect_options *ndo, const u_char *bp, u_int len) |
| { |
| u_int n, vn; |
| uint8_t ver; |
| uint8_t flags; |
| u_int length; |
| uint8_t md_type; |
| uint8_t next_protocol; |
| uint32_t service_path_id; |
| uint8_t service_index; |
| uint32_t ctx; |
| uint16_t tlv_class; |
| uint8_t tlv_type; |
| uint8_t tlv_len; |
| u_int next_len; |
| |
| ndo->ndo_protocol = "nsh"; |
| /* print Base Header and Service Path Header */ |
| if (len < NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN) |
| goto trunc; |
| |
| ND_TCHECK_LEN(bp, NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN); |
| |
| ver = (uint8_t)(GET_U_1(bp) >> 6); |
| flags = GET_U_1(bp); |
| bp += 1; |
| length = GET_U_1(bp); |
| bp += 1; |
| md_type = GET_U_1(bp); |
| bp += 1; |
| next_protocol = GET_U_1(bp); |
| bp += 1; |
| service_path_id = GET_BE_U_3(bp); |
| bp += 3; |
| service_index = GET_U_1(bp); |
| bp += 1; |
| |
| ND_PRINT("NSH, "); |
| if (ndo->ndo_vflag > 1) { |
| ND_PRINT("ver %u, ", ver); |
| } |
| ND_PRINT("flags [%s], ", bittok2str_nosep(nsh_flags, "none", flags)); |
| if (ndo->ndo_vflag > 2) { |
| ND_PRINT("length %u, ", length); |
| ND_PRINT("md type 0x%x, ", md_type); |
| } |
| if (ndo->ndo_vflag > 1) { |
| ND_PRINT("next-protocol 0x%x, ", next_protocol); |
| } |
| ND_PRINT("service-path-id 0x%06x, ", service_path_id); |
| ND_PRINT("service-index 0x%x", service_index); |
| |
| /* Make sure we have all the headers */ |
| if (len < length * NSH_HDR_WORD_SIZE) |
| goto trunc; |
| |
| ND_TCHECK_LEN(bp, length * NSH_HDR_WORD_SIZE); |
| |
| /* |
| * length includes the lengths of the Base and Service Path headers. |
| * That means it must be at least 2. |
| */ |
| if (length < 2) |
| goto trunc; |
| |
| /* |
| * Print, or skip, the Context Headers. |
| * (length - 2) is the length of those headers. |
| */ |
| if (ndo->ndo_vflag > 2) { |
| if (md_type == 0x01) { |
| for (n = 0; n < length - 2; n++) { |
| ctx = GET_BE_U_4(bp); |
| bp += NSH_HDR_WORD_SIZE; |
| ND_PRINT("\n Context[%02u]: 0x%08x", n, ctx); |
| } |
| } |
| else if (md_type == 0x02) { |
| n = 0; |
| while (n < length - 2) { |
| tlv_class = GET_BE_U_2(bp); |
| bp += 2; |
| tlv_type = GET_U_1(bp); |
| bp += 1; |
| tlv_len = GET_U_1(bp); |
| bp += 1; |
| |
| ND_PRINT("\n TLV Class %u, Type %u, Len %u", |
| tlv_class, tlv_type, tlv_len); |
| |
| n += 1; |
| |
| if (length - 2 < n + tlv_len) { |
| ND_PRINT(" ERROR: invalid-tlv-length"); |
| return; |
| } |
| |
| for (vn = 0; vn < tlv_len; vn++) { |
| ctx = GET_BE_U_4(bp); |
| bp += NSH_HDR_WORD_SIZE; |
| ND_PRINT("\n Value[%02u]: 0x%08x", vn, ctx); |
| } |
| n += tlv_len; |
| } |
| } |
| else { |
| ND_PRINT("ERROR: unknown-next-protocol"); |
| return; |
| } |
| } |
| else { |
| bp += (length - 2) * NSH_HDR_WORD_SIZE; |
| } |
| ND_PRINT(ndo->ndo_vflag ? "\n " : ": "); |
| |
| /* print Next Protocol */ |
| next_len = len - length * NSH_HDR_WORD_SIZE; |
| switch (next_protocol) { |
| case 0x1: |
| ip_print(ndo, bp, next_len); |
| break; |
| case 0x2: |
| ip6_print(ndo, bp, next_len); |
| break; |
| case 0x3: |
| ether_print(ndo, bp, next_len, ND_BYTES_AVAILABLE_AFTER(bp), NULL, NULL); |
| break; |
| default: |
| ND_PRINT("ERROR: unknown-next-protocol"); |
| return; |
| } |
| |
| return; |
| |
| trunc: |
| nd_print_trunc(ndo); |
| } |
| |