tcpdump/print-babel.c
Denis Ovsienko 833425ab80 Babel: improve printing of time intervals
All Babel intervals are encoded in centiseconds and must not be 0. In an
Update TLV the interval value 0xFFFF means infinity (RFC6126 Section
4.4.9). Update the test cases.
2013-10-18 09:24:37 +04:00

557 lines
16 KiB
C

/*
* Copyright (c) 2007-2011 Grégoire Henry, Juliusz Chroboczek
*
* 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.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT 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 PROJECT 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <tcpdump-stdinc.h>
#include <stdio.h>
#include <string.h>
#include "addrtoname.h"
#include "interface.h"
#include "extract.h"
static void babel_print_v2(const u_char *cp, u_int length);
void
babel_print(const u_char *cp, u_int length) {
printf("babel");
TCHECK2(*cp, 4);
if(cp[0] != 42) {
printf(" malformed header");
return;
} else {
printf(" %d", cp[1]);
}
switch(cp[1]) {
case 2:
babel_print_v2(cp,length);
break;
default:
printf(" unknown version");
break;
}
return;
trunc:
printf(" [|babel]");
return;
}
/* TLVs */
#define MESSAGE_PAD1 0
#define MESSAGE_PADN 1
#define MESSAGE_ACK_REQ 2
#define MESSAGE_ACK 3
#define MESSAGE_HELLO 4
#define MESSAGE_IHU 5
#define MESSAGE_ROUTER_ID 6
#define MESSAGE_NH 7
#define MESSAGE_UPDATE 8
#define MESSAGE_REQUEST 9
#define MESSAGE_MH_REQUEST 10
#define MESSAGE_TSPC 11
#define MESSAGE_HMAC 12
/* sub-TLVs */
#define MESSAGE_SUB_PAD1 0
#define MESSAGE_SUB_PADN 1
#define MESSAGE_SUB_DIVERSITY 2
/* Diversity sub-TLV channel codes */
static const struct tok diversity_str[] = {
{ 0, "reserved" },
{ 255, "all" },
{ 0, NULL }
};
static const char *
format_id(const u_char *id)
{
static char buf[25];
snprintf(buf, 25, "%02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x",
id[0], id[1], id[2], id[3], id[4], id[5], id[6], id[7]);
buf[24] = '\0';
return buf;
}
static const unsigned char v4prefix[16] =
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
static const char *
format_prefix(const u_char *prefix, unsigned char plen)
{
static char buf[50];
if(plen >= 96 && memcmp(prefix, v4prefix, 12) == 0)
snprintf(buf, 50, "%s/%u", ipaddr_string(prefix + 12), plen - 96);
else
#ifdef INET6
snprintf(buf, 50, "%s/%u", ip6addr_string(prefix), plen);
#else
snprintf(buf, 50, "IPv6 addresses not supported");
#endif
buf[49] = '\0';
return buf;
}
static const char *
format_address(const u_char *prefix)
{
if(memcmp(prefix, v4prefix, 12) == 0)
return ipaddr_string(prefix + 12);
else
#ifdef INET6
return ip6addr_string(prefix);
#else
return "IPv6 addresses not supported";
#endif
}
static const char *
format_interval(const u_int16_t i)
{
static char buf[sizeof("0000.0s")];
if (i == 0)
return "0.0s (bogus)";
snprintf(buf, sizeof(buf), "%u.%us", i / 10, i % 10);
return buf;
}
static const char *
format_interval_update(const u_int16_t i)
{
return i == 0xFFFF ? "infinity" : format_interval(i);
}
/* Return number of octets consumed from the input buffer (not the prefix length
* in bytes), or -1 for encoding error. */
static int
network_prefix(int ae, int plen, unsigned int omitted,
const unsigned char *p, const unsigned char *dp,
unsigned int len, unsigned char *p_r)
{
unsigned pb;
unsigned char prefix[16];
int consumed = 0;
if(plen >= 0)
pb = (plen + 7) / 8;
else if(ae == 1)
pb = 4;
else
pb = 16;
if(pb > 16)
return -1;
memset(prefix, 0, 16);
switch(ae) {
case 0: break;
case 1:
if(omitted > 4 || pb > 4 || (pb > omitted && len < pb - omitted))
return -1;
memcpy(prefix, v4prefix, 12);
if(omitted) {
if (dp == NULL) return -1;
memcpy(prefix, dp, 12 + omitted);
}
if(pb > omitted) {
memcpy(prefix + 12 + omitted, p, pb - omitted);
consumed = pb - omitted;
}
break;
case 2:
if(omitted > 16 || (pb > omitted && len < pb - omitted))
return -1;
if(omitted) {
if (dp == NULL) return -1;
memcpy(prefix, dp, omitted);
}
if(pb > omitted) {
memcpy(prefix + omitted, p, pb - omitted);
consumed = pb - omitted;
}
break;
case 3:
if(pb > 8 && len < pb - 8) return -1;
prefix[0] = 0xfe;
prefix[1] = 0x80;
if(pb > 8) {
memcpy(prefix + 8, p, pb - 8);
consumed = pb - 8;
}
break;
default:
return -1;
}
memcpy(p_r, prefix, 16);
return consumed;
}
static int
network_address(int ae, const unsigned char *a, unsigned int len,
unsigned char *a_r)
{
return network_prefix(ae, -1, 0, a, NULL, len, a_r);
}
/*
* Sub-TLVs consume the "extra data" of Babel TLVs (see Section 4.3 of RFC6126),
* their encoding is similar to the encoding of TLVs, but the type namespace is
* different:
*
* o Type 0 stands for Pad1 sub-TLV with the same encoding as the Pad1 TLV.
* o Type 1 stands for PadN sub-TLV with the same encoding as the PadN TLV.
* o Type 2 stands for Diversity sub-TLV, which propagates diversity routing
* data. Its body is a variable-length sequence of 8-bit unsigned integers,
* each representing per-hop number of interferring radio channel for the
* prefix. Channel 0 is invalid and must not be used in the sub-TLV, channel
* 255 interferes with any other channel.
*
* Sub-TLV types 0 and 1 are valid for any TLV type, whether sub-TLV type 2 is
* only valid for TLV type 8 (Update). Note that within an Update TLV a missing
* Diversity sub-TLV is not the same as a Diversity sub-TLV with an empty body.
* The former would mean a lack of any claims about the interference, and the
* latter would state that interference is definitely absent. */
static void
subtlvs_print(const u_char *cp, const u_char *ep, const uint8_t tlv_type) {
uint8_t subtype, sublen;
const char *sep;
while (cp < ep) {
subtype = *cp++;
if(subtype == MESSAGE_SUB_PAD1) {
printf(" sub-pad1");
continue;
}
if(cp == ep)
goto corrupt;
sublen = *cp++;
if(cp + sublen > ep)
goto corrupt;
switch(subtype) {
case MESSAGE_SUB_PADN:
printf(" sub-padn");
cp += sublen;
break;
case MESSAGE_SUB_DIVERSITY:
printf(" sub-diversity");
if (sublen == 0) {
printf(" empty");
break;
}
sep = " ";
while(sublen--) {
printf("%s%s", sep, tok2str(diversity_str, "%u", *cp++));
sep = "-";
}
if(tlv_type != MESSAGE_UPDATE)
printf(" (bogus)");
break;
default:
printf(" sub-unknown-0x%02x", subtype);
cp += sublen;
} /* switch */
} /* while */
return;
corrupt:
printf(" (corrupt)");
}
#define ICHECK(i, l) \
if ((i) + (l) > bodylen || (i) + (l) > length) goto corrupt;
static void
babel_print_v2(const u_char *cp, u_int length) {
u_int i;
u_short bodylen;
u_char v4_prefix[16] =
{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xFF, 0xFF, 0, 0, 0, 0 };
u_char v6_prefix[16] = {0};
TCHECK2(*cp, 4);
if (length < 4)
goto corrupt;
bodylen = EXTRACT_16BITS(cp + 2);
printf(" (%u)", bodylen);
/* Process the TLVs in the body */
i = 0;
while(i < bodylen) {
const u_char *message;
u_int type, len;
message = cp + 4 + i;
TCHECK2(*message, 1);
if((type = message[0]) == MESSAGE_PAD1) {
printf(vflag ? "\n\tPad 1" : " pad1");
i += 1;
continue;
}
TCHECK2(*message, 2);
ICHECK(i, 2);
len = message[1];
TCHECK2(*message, 2 + len);
ICHECK(i, 2 + len);
switch(type) {
case MESSAGE_PADN: {
if(!vflag)
printf(" padN");
else
printf("\n\tPad %d", len + 2);
}
break;
case MESSAGE_ACK_REQ: {
u_short nonce, interval;
if(!vflag)
printf(" ack-req");
else {
printf("\n\tAcknowledgment Request ");
if(len < 6) goto corrupt;
nonce = EXTRACT_16BITS(message + 4);
interval = EXTRACT_16BITS(message + 6);
printf("%04x %s", nonce, format_interval(interval));
}
}
break;
case MESSAGE_ACK: {
u_short nonce;
if(!vflag)
printf(" ack");
else {
printf("\n\tAcknowledgment ");
if(len < 2) goto corrupt;
nonce = EXTRACT_16BITS(message + 2);
printf("%04x", nonce);
}
}
break;
case MESSAGE_HELLO: {
u_short seqno, interval;
if(!vflag)
printf(" hello");
else {
printf("\n\tHello ");
if(len < 6) goto corrupt;
seqno = EXTRACT_16BITS(message + 4);
interval = EXTRACT_16BITS(message + 6);
printf("seqno %u interval %s", seqno, format_interval(interval));
}
}
break;
case MESSAGE_IHU: {
unsigned short txcost, interval;
if(!vflag)
printf(" ihu");
else {
u_char address[16];
int rc;
printf("\n\tIHU ");
if(len < 6) goto corrupt;
txcost = EXTRACT_16BITS(message + 4);
interval = EXTRACT_16BITS(message + 6);
rc = network_address(message[2], message + 8, len - 6, address);
if(rc < 0) { printf("[|babel]"); break; }
printf("%s txcost %u interval %s",
format_address(address), txcost, format_interval(interval));
}
}
break;
case MESSAGE_ROUTER_ID: {
if(!vflag)
printf(" router-id");
else {
printf("\n\tRouter Id");
if(len < 10) goto corrupt;
printf(" %s", format_id(message + 4));
}
}
break;
case MESSAGE_NH: {
if(!vflag)
printf(" nh");
else {
int rc;
u_char nh[16];
printf("\n\tNext Hop");
if(len < 2) goto corrupt;
rc = network_address(message[2], message + 4, len - 2, nh);
if(rc < 0) goto corrupt;
printf(" %s", format_address(nh));
}
}
break;
case MESSAGE_UPDATE: {
if(!vflag) {
printf(" update");
if(len < 1)
printf("/truncated");
else
printf("%s%s%s",
(message[3] & 0x80) ? "/prefix": "",
(message[3] & 0x40) ? "/id" : "",
(message[3] & 0x3f) ? "/unknown" : "");
} else {
u_short interval, seqno, metric;
u_char plen;
int rc;
u_char prefix[16];
printf("\n\tUpdate");
if(len < 10) goto corrupt;
plen = message[4] + (message[2] == 1 ? 96 : 0);
rc = network_prefix(message[2], message[4], message[5],
message + 12,
message[2] == 1 ? v4_prefix : v6_prefix,
len - 10, prefix);
if(rc < 0) goto corrupt;
interval = EXTRACT_16BITS(message + 6);
seqno = EXTRACT_16BITS(message + 8);
metric = EXTRACT_16BITS(message + 10);
printf("%s%s%s %s metric %u seqno %u interval %s",
(message[3] & 0x80) ? "/prefix": "",
(message[3] & 0x40) ? "/id" : "",
(message[3] & 0x3f) ? "/unknown" : "",
format_prefix(prefix, plen),
metric, seqno, format_interval_update(interval));
if(message[3] & 0x80) {
if(message[2] == 1)
memcpy(v4_prefix, prefix, 16);
else
memcpy(v6_prefix, prefix, 16);
}
/* extra data? */
if((u_int)rc < len - 10)
subtlvs_print(message + 12 + rc, message + 2 + len, type);
}
}
break;
case MESSAGE_REQUEST: {
if(!vflag)
printf(" request");
else {
int rc;
u_char prefix[16], plen;
printf("\n\tRequest ");
if(len < 2) goto corrupt;
plen = message[3] + (message[2] == 1 ? 96 : 0);
rc = network_prefix(message[2], message[3], 0,
message + 4, NULL, len - 2, prefix);
if(rc < 0) goto corrupt;
plen = message[3] + (message[2] == 1 ? 96 : 0);
printf("for %s",
message[2] == 0 ? "any" : format_prefix(prefix, plen));
}
}
break;
case MESSAGE_MH_REQUEST : {
if(!vflag)
printf(" mh-request");
else {
int rc;
u_short seqno;
u_char prefix[16], plen;
printf("\n\tMH-Request ");
if(len < 14) goto corrupt;
seqno = EXTRACT_16BITS(message + 4);
rc = network_prefix(message[2], message[3], 0,
message + 16, NULL, len - 14, prefix);
if(rc < 0) goto corrupt;
plen = message[3] + (message[2] == 1 ? 96 : 0);
printf("(%u hops) for %s seqno %u id %s",
message[6], format_prefix(prefix, plen),
seqno, format_id(message + 8));
}
}
break;
case MESSAGE_TSPC :
if(!vflag)
printf(" tspc");
else {
printf("\n\tTS/PC ");
if(len < 6) goto corrupt;
printf("timestamp %u packetcounter %u", EXTRACT_32BITS (message + 4),
EXTRACT_16BITS(message + 2));
}
break;
case MESSAGE_HMAC : {
if(!vflag)
printf(" hmac");
else {
unsigned j;
printf("\n\tHMAC ");
if(len < 18) goto corrupt;
printf("key-id %u digest-%u ", EXTRACT_16BITS(message + 2), len - 2);
for (j = 0; j < len - 2; j++)
printf ("%02X", message[4 + j]);
}
}
break;
default:
if(!vflag)
printf(" unknown");
else
printf("\n\tUnknown message type %d", type);
}
i += len + 2;
}
return;
trunc:
printf(" [|babel]");
return;
corrupt:
printf(" (corrupt)");
return;
}