/**
* Copyright (c) 2012
*
* Gregory Detal <gregory.detal@uclouvain.be>
* Christoph Paasch <christoph.paasch@uclouvain.be>
*
* 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 University nor of the Laboratory may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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: Multipath TCP (MPTCP) printer */
/* specification: RFC 6824 */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <netdissect-stdinc.h>
#include "netdissect.h"
#include "extract.h"
#include "addrtoname.h"
#include "tcp.h"
#define MPTCP_SUB_CAPABLE 0x0
#define MPTCP_SUB_JOIN 0x1
#define MPTCP_SUB_DSS 0x2
#define MPTCP_SUB_ADD_ADDR 0x3
#define MPTCP_SUB_REMOVE_ADDR 0x4
#define MPTCP_SUB_PRIO 0x5
#define MPTCP_SUB_FAIL 0x6
#define MPTCP_SUB_FCLOSE 0x7
struct mptcp_option {
uint8_t kind;
uint8_t len;
uint8_t sub_etc; /* subtype upper 4 bits, other stuff lower 4 bits */
};
#define MPTCP_OPT_SUBTYPE(sub_etc) (((sub_etc) >> 4) & 0xF)
struct mp_capable {
uint8_t kind;
uint8_t len;
uint8_t sub_ver;
uint8_t flags;
uint8_t sender_key[8];
uint8_t receiver_key[8];
};
#define MP_CAPABLE_OPT_VERSION(sub_ver) (((sub_ver) >> 0) & 0xF)
#define MP_CAPABLE_C 0x80
#define MP_CAPABLE_S 0x01
struct mp_join {
uint8_t kind;
uint8_t len;
uint8_t sub_b;
uint8_t addr_id;
union {
struct {
uint8_t token[4];
uint8_t nonce[4];
} syn;
struct {
uint8_t mac[8];
uint8_t nonce[4];
} synack;
struct {
uint8_t mac[20];
} ack;
} u;
};
#define MP_JOIN_B 0x01
struct mp_dss {
uint8_t kind;
uint8_t len;
uint8_t sub;
uint8_t flags;
};
#define MP_DSS_F 0x10
#define MP_DSS_m 0x08
#define MP_DSS_M 0x04
#define MP_DSS_a 0x02
#define MP_DSS_A 0x01
struct mp_add_addr {
uint8_t kind;
uint8_t len;
uint8_t sub_ipver;
uint8_t addr_id;
union {
struct {
uint8_t addr[4];
uint8_t port[2];
} v4;
struct {
uint8_t addr[16];
uint8_t port[2];
} v6;
} u;
};
#define MP_ADD_ADDR_IPVER(sub_ipver) (((sub_ipver) >> 0) & 0xF)
struct mp_remove_addr {
uint8_t kind;
uint8_t len;
uint8_t sub;
/* list of addr_id */
uint8_t addrs_id;
};
struct mp_fail {
uint8_t kind;
uint8_t len;
uint8_t sub;
uint8_t resv;
uint8_t data_seq[8];
};
struct mp_close {
uint8_t kind;
uint8_t len;
uint8_t sub;
uint8_t rsv;
uint8_t key[8];
};
struct mp_prio {
uint8_t kind;
uint8_t len;
uint8_t sub_b;
uint8_t addr_id;
};
#define MP_PRIO_B 0x01
static int
dummy_print(netdissect_options *ndo _U_,
const u_char *opt _U_, u_int opt_len _U_, u_char flags _U_)
{
return 1;
}
static int
mp_capable_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags)
{
const struct mp_capable *mpc = (const struct mp_capable *) opt;
if (!(opt_len == 12 && (flags & TH_SYN)) &&
!(opt_len == 20 && (flags & (TH_SYN | TH_ACK)) == TH_ACK))
return 0;
if (MP_CAPABLE_OPT_VERSION(mpc->sub_ver) != 0) {
ND_PRINT((ndo, " Unknown Version (%d)", MP_CAPABLE_OPT_VERSION(mpc->sub_ver)));
return 1;
}
if (mpc->flags & MP_CAPABLE_C)
ND_PRINT((ndo, " csum"));
ND_PRINT((ndo, " {0x%" PRIx64, EXTRACT_64BITS(mpc->sender_key)));
if (opt_len == 20) /* ACK */
ND_PRINT((ndo, ",0x%" PRIx64, EXTRACT_64BITS(mpc->receiver_key)));
ND_PRINT((ndo, "}"));
return 1;
}
static int
mp_join_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags)
{
const struct mp_join *mpj = (const struct mp_join *) opt;
if (!(opt_len == 12 && (flags & TH_SYN)) &&
!(opt_len == 16 && (flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) &&
!(opt_len == 24 && (flags & TH_ACK)))
return 0;
if (opt_len != 24) {
if (mpj->sub_b & MP_JOIN_B)
ND_PRINT((ndo, " backup"));
ND_PRINT((ndo, " id %u", mpj->addr_id));
}
switch (opt_len) {
case 12: /* SYN */
ND_PRINT((ndo, " token 0x%x" " nonce 0x%x",
EXTRACT_32BITS(mpj->u.syn.token),
EXTRACT_32BITS(mpj->u.syn.nonce)));
break;
case 16: /* SYN/ACK */
ND_PRINT((ndo, " hmac 0x%" PRIx64 " nonce 0x%x",
EXTRACT_64BITS(mpj->u.synack.mac),
EXTRACT_32BITS(mpj->u.synack.nonce)));
break;
case 24: {/* ACK */
size_t i;
ND_PRINT((ndo, " hmac 0x"));
for (i = 0; i < sizeof(mpj->u.ack.mac); ++i)
ND_PRINT((ndo, "%02x", mpj->u.ack.mac[i]));
}
default:
break;
}
return 1;
}
static int
mp_dss_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags)
{
const struct mp_dss *mdss = (const struct mp_dss *) opt;
/* We need the flags, at a minimum. */
if (opt_len < 4)
return 0;
if (flags & TH_SYN)
return 0;
if (mdss->flags & MP_DSS_F)
ND_PRINT((ndo, " fin"));
opt += 4;
opt_len -= 4;
if (mdss->flags & MP_DSS_A) {
/* Ack present */
ND_PRINT((ndo, " ack "));
/*
* If the a flag is set, we have an 8-byte ack; if it's
* clear, we have a 4-byte ack.
*/
if (mdss->flags & MP_DSS_a) {
if (opt_len < 8)
return 0;
ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt)));
opt += 8;
opt_len -= 8;
} else {
if (opt_len < 4)
return 0;
ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt)));
opt += 4;
opt_len -= 4;
}
}
if (mdss->flags & MP_DSS_M) {
/*
* Data Sequence Number (DSN), Subflow Sequence Number (SSN),
* Data-Level Length present, and Checksum possibly present.
*/
ND_PRINT((ndo, " seq "));
/*
* If the m flag is set, we have an 8-byte NDS; if it's clear,
* we have a 4-byte DSN.
*/
if (mdss->flags & MP_DSS_m) {
if (opt_len < 8)
return 0;
ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt)));
opt += 8;
opt_len -= 8;
} else {
if (opt_len < 4)
return 0;
ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt)));
opt += 4;
opt_len -= 4;
}
if (opt_len < 4)
return 0;
ND_PRINT((ndo, " subseq %u", EXTRACT_32BITS(opt)));
opt += 4;
opt_len -= 4;
if (opt_len < 2)
return 0;
ND_PRINT((ndo, " len %u", EXTRACT_16BITS(opt)));
opt += 2;
opt_len -= 2;
/*
* The Checksum is present only if negotiated.
* If there are at least 2 bytes left, process the next 2
* bytes as the Checksum.
*/
if (opt_len >= 2) {
ND_PRINT((ndo, " csum 0x%x", EXTRACT_16BITS(opt)));
opt_len -= 2;
}
}
if (opt_len != 0)
return 0;
return 1;
}
static int
add_addr_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags _U_)
{
const struct mp_add_addr *add_addr = (const struct mp_add_addr *) opt;
u_int ipver = MP_ADD_ADDR_IPVER(add_addr->sub_ipver);
if (!((opt_len == 8 || opt_len == 10) && ipver == 4) &&
!((opt_len == 20 || opt_len == 22) && ipver == 6))
return 0;
ND_PRINT((ndo, " id %u", add_addr->addr_id));
switch (ipver) {
case 4:
ND_PRINT((ndo, " %s", ipaddr_string(ndo, add_addr->u.v4.addr)));
if (opt_len == 10)
ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v4.port)));
break;
case 6:
ND_PRINT((ndo, " %s", ip6addr_string(ndo, add_addr->u.v6.addr)));
if (opt_len == 22)
ND_PRINT((ndo, ":%u", EXTRACT_16BITS(add_addr->u.v6.port)));
break;
default:
return 0;
}
return 1;
}
static int
remove_addr_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags _U_)
{
const struct mp_remove_addr *remove_addr = (const struct mp_remove_addr *) opt;
const uint8_t *addr_id = &remove_addr->addrs_id;
if (opt_len < 4)
return 0;
opt_len -= 3;
ND_PRINT((ndo, " id"));
while (opt_len--)
ND_PRINT((ndo, " %u", *addr_id++));
return 1;
}
static int
mp_prio_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags _U_)
{
const struct mp_prio *mpp = (const struct mp_prio *) opt;
if (opt_len != 3 && opt_len != 4)
return 0;
if (mpp->sub_b & MP_PRIO_B)
ND_PRINT((ndo, " backup"));
else
ND_PRINT((ndo, " non-backup"));
if (opt_len == 4)
ND_PRINT((ndo, " id %u", mpp->addr_id));
return 1;
}
static int
mp_fail_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags _U_)
{
if (opt_len != 12)
return 0;
ND_PRINT((ndo, " seq %" PRIu64, EXTRACT_64BITS(opt + 4)));
return 1;
}
static int
mp_fast_close_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags _U_)
{
if (opt_len != 12)
return 0;
ND_PRINT((ndo, " key 0x%" PRIx64, EXTRACT_64BITS(opt + 4)));
return 1;
}
static const struct {
const char *name;
int (*print)(netdissect_options *, const u_char *, u_int, u_char);
} mptcp_options[] = {
{ "capable", mp_capable_print},
{ "join", mp_join_print },
{ "dss", mp_dss_print },
{ "add-addr", add_addr_print },
{ "rem-addr", remove_addr_print },
{ "prio", mp_prio_print },
{ "fail", mp_fail_print },
{ "fast-close", mp_fast_close_print },
{ "unknown", dummy_print },
};
int
mptcp_print(netdissect_options *ndo,
const u_char *cp, u_int len, u_char flags)
{
const struct mptcp_option *opt;
u_int subtype;
if (len < 3)
return 0;
opt = (const struct mptcp_option *) cp;
subtype = min(MPTCP_OPT_SUBTYPE(opt->sub_etc), MPTCP_SUB_FCLOSE + 1);
ND_PRINT((ndo, " %s", mptcp_options[subtype].name));
return mptcp_options[subtype].print(ndo, cp, len, flags);
}