diff options
Diffstat (limited to 'contrib/tcpdump/print-nsh.c')
| -rw-r--r-- | contrib/tcpdump/print-nsh.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/contrib/tcpdump/print-nsh.c b/contrib/tcpdump/print-nsh.c new file mode 100644 index 0000000..abd722d --- /dev/null +++ b/contrib/tcpdump/print-nsh.c @@ -0,0 +1,185 @@ +/* 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 char tstr[] = " [|NSH]"; +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) +{ + int n, vn; + uint8_t ver; + uint8_t flags; + uint8_t 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; + + /* print Base Header and Service Path Header */ + if (len < NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN) + goto trunc; + + ND_TCHECK2(*bp, NSH_BASE_HDR_LEN + NSH_SERVICE_PATH_HDR_LEN); + + ver = (uint8_t)(*bp >> 6); + flags = *bp; + bp += 1; + length = *bp; + bp += 1; + md_type = *bp; + bp += 1; + next_protocol = *bp; + bp += 1; + service_path_id = EXTRACT_24BITS(bp); + bp += 3; + service_index = *bp; + bp += 1; + + ND_PRINT((ndo, "NSH, ")); + if (ndo->ndo_vflag > 1) { + ND_PRINT((ndo, "ver %d, ", ver)); + } + ND_PRINT((ndo, "flags [%s], ", bittok2str_nosep(nsh_flags, "none", flags))); + if (ndo->ndo_vflag > 2) { + ND_PRINT((ndo, "length %d, ", length)); + ND_PRINT((ndo, "md type 0x%x, ", md_type)); + } + if (ndo->ndo_vflag > 1) { + ND_PRINT((ndo, "next-protocol 0x%x, ", next_protocol)); + } + ND_PRINT((ndo, "service-path-id 0x%06x, ", service_path_id)); + ND_PRINT((ndo, "service-index 0x%x", service_index)); + + /* Make sure we have all the headers */ + if (len < length * NSH_HDR_WORD_SIZE) + goto trunc; + + ND_TCHECK2(*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 = EXTRACT_32BITS(bp); + bp += NSH_HDR_WORD_SIZE; + ND_PRINT((ndo, "\n Context[%02d]: 0x%08x", n, ctx)); + } + } + else if (md_type == 0x02) { + n = 0; + while (n < length - 2) { + tlv_class = EXTRACT_16BITS(bp); + bp += 2; + tlv_type = *bp; + bp += 1; + tlv_len = *bp; + bp += 1; + + ND_PRINT((ndo, "\n TLV Class %d, Type %d, Len %d", + tlv_class, tlv_type, tlv_len)); + + n += 1; + + if (length - 2 < n + tlv_len) { + ND_PRINT((ndo, " ERROR: invalid-tlv-length")); + return; + } + + for (vn = 0; vn < tlv_len; vn++) { + ctx = EXTRACT_32BITS(bp); + bp += NSH_HDR_WORD_SIZE; + ND_PRINT((ndo, "\n Value[%02d]: 0x%08x", vn, ctx)); + } + n += tlv_len; + } + } + else { + ND_PRINT((ndo, "ERROR: unknown-next-protocol")); + return; + } + } + else { + bp += (length - 2) * NSH_HDR_WORD_SIZE; + } + ND_PRINT((ndo, 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, ndo->ndo_snapend - bp, NULL, NULL); + break; + default: + ND_PRINT((ndo, "ERROR: unknown-next-protocol")); + return; + } + + return; + +trunc: + ND_PRINT((ndo, "%s", tstr)); +} + |
