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/* 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));
}
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