/* $NetBSD: print-tcp.c,v 1.9 2007/07/26 18:15:12 plunky Exp $ */

/*

* Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997

* The Regents of the University of California. All rights reserved.

*

* Copyright (c) 1999-2004 The tcpdump.org project

*

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that: (1) source code distributions

* retain the above copyright notice and this paragraph in its entirety, (2)

* distributions including binary code include the above copyright notice and

* this paragraph in its entirety in the documentation or other materials

* provided with the distribution, and (3) all advertising materials mentioning

* features or use of this software display the following acknowledgement:

* ``This product includes software developed by the University of California,

* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of

* the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED

* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF

* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

*/

/* \summary: TCP printer */

#ifndef lint

#else

__RCSID("$NetBSD: print-tcp.c,v 1.8 2007/07/24 11:53:48 drochner Exp $");

#endif

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include "netdissect-stdinc.h"

#include <stdlib.h>

#include <string.h>

#define ND_LONGJMP_FROM_TCHECK

#include "netdissect.h"

#include "addrtoname.h"

#include "extract.h"

#include "diag-control.h"

#include "tcp.h"

#include "ip.h"

#include "ip6.h"

#include "ipproto.h"

#include "rpc_auth.h"

#include "rpc_msg.h"

#ifdef HAVE_LIBCRYPTO

#include <openssl/md5.h>

#include "signature.h"

static int tcp_verify_signature(netdissect_options *ndo,

const struct ip *ip, const struct tcphdr *tp,

const u_char *data, u_int length, const u_char *rcvsig);

#endif

static void print_tcp_rst_data(netdissect_options *, const u_char *sp, u_int length);

static void print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp,

u_int datalen);

#define MAX_RST_DATA_LEN 30

struct tha {

};

struct tcp_seq_hash {

};

struct tha6 {

};

struct tcp_seq_hash6 {

};

#define TSEQ_HASHSIZE 919

/* These tcp options do not have the size octet */

#define ZEROLENOPT(o) ((o) == TCPOPT_EOL || (o) == TCPOPT_NOP)

static struct tcp_seq_hash tcp_seq_hash4[TSEQ_HASHSIZE];

static struct tcp_seq_hash6 tcp_seq_hash6[TSEQ_HASHSIZE];

const struct tok tcp_flag_values[] = {

{ TH_FIN, "F" },

{ TH_SYN, "S" },

{ TH_RST, "R" },

{ TH_PUSH, "P" },

{ TH_ACK, "." },

{ TH_URG, "U" },

{ TH_ECNECHO, "E" },

{ TH_CWR, "W" },

{ 0, NULL }

};

static const struct tok tcp_option_values[] = {

{ TCPOPT_EOL, "eol" },

{ TCPOPT_NOP, "nop" },

{ TCPOPT_MAXSEG, "mss" },

{ TCPOPT_WSCALE, "wscale" },

{ TCPOPT_SACKOK, "sackOK" },

{ TCPOPT_SACK, "sack" },

{ TCPOPT_ECHO, "echo" },

{ TCPOPT_ECHOREPLY, "echoreply" },

{ TCPOPT_TIMESTAMP, "TS" },

{ TCPOPT_CC, "cc" },

{ TCPOPT_CCNEW, "ccnew" },

{ TCPOPT_CCECHO, "" },

{ TCPOPT_SIGNATURE, "md5" },

{ TCPOPT_SCPS, "scps" },

{ TCPOPT_UTO, "uto" },

{ TCPOPT_TCPAO, "tcp-ao" },

{ TCPOPT_MPTCP, "mptcp" },

{ TCPOPT_FASTOPEN, "tfo" },

{ TCPOPT_EXPERIMENT2, "exp" },

{ 0, NULL }

};

static uint16_t

tcp_cksum(netdissect_options *ndo,

const struct ip *ip,

const struct tcphdr *tp,

u_int len)

{

return nextproto4_cksum(ndo, ip, (const uint8_t *)tp, len, len,

IPPROTO_TCP);

}

static uint16_t

tcp6_cksum(netdissect_options *ndo,

const struct ip6_hdr *ip6,

const struct tcphdr *tp,

u_int len)

{

return nextproto6_cksum(ndo, ip6, (const uint8_t *)tp, len, len,

IPPROTO_TCP);

}

void

tcp_print(netdissect_options *ndo,

const u_char *bp, u_int length,

const u_char *bp2, int fragmented)

{

const struct tcphdr *tp;

const struct ip *ip;

u_char flags;

u_int hlen;

char ch;

uint16_t sport, dport, win, urp;

uint32_t seq, ack, thseq, thack;

u_int utoval;

uint16_t magic;

int rev;

const struct ip6_hdr *ip6;

u_int header_len; /* Header length in bytes */

ndo->ndo_protocol = "tcp";

tp = (const struct tcphdr *)bp;

ip = (const struct ip *)bp2;

if (IP_V(ip) == 6)

ip6 = (const struct ip6_hdr *)bp2;

else

ip6 = NULL;

ch = '\0';

if (!ND_TTEST_2(tp->th_dport)) {

if (ip6) {

ND_PRINT("%s > %s:",

GET_IP6ADDR_STRING(ip6->ip6_src),

GET_IP6ADDR_STRING(ip6->ip6_dst));

} else {

ND_PRINT("%s > %s:",

GET_IPADDR_STRING(ip->ip_src),

GET_IPADDR_STRING(ip->ip_dst));

}

nd_trunc_longjmp(ndo);

}

sport = GET_BE_U_2(tp->th_sport);

dport = GET_BE_U_2(tp->th_dport);

if (ip6) {

if (GET_U_1(ip6->ip6_nxt) == IPPROTO_TCP) {

ND_PRINT("%s.%s > %s.%s: ",

GET_IP6ADDR_STRING(ip6->ip6_src),

tcpport_string(ndo, sport),

GET_IP6ADDR_STRING(ip6->ip6_dst),

tcpport_string(ndo, dport));

} else {

ND_PRINT("%s > %s: ",

tcpport_string(ndo, sport), tcpport_string(ndo, dport));

}

} else {

if (GET_U_1(ip->ip_p) == IPPROTO_TCP) {

ND_PRINT("%s.%s > %s.%s: ",

GET_IPADDR_STRING(ip->ip_src),

tcpport_string(ndo, sport),

GET_IPADDR_STRING(ip->ip_dst),

tcpport_string(ndo, dport));

} else {

ND_PRINT("%s > %s: ",

tcpport_string(ndo, sport), tcpport_string(ndo, dport));

}

}

hlen = TH_OFF(tp) * 4;

if (hlen < sizeof(*tp)) {

ND_PRINT(" tcp %u [bad hdr length %u - too short, < %zu]",

length - hlen, hlen, sizeof(*tp));

goto invalid;

}

seq = GET_BE_U_4(tp->th_seq);

ack = GET_BE_U_4(tp->th_ack);

win = GET_BE_U_2(tp->th_win);

urp = GET_BE_U_2(tp->th_urp);

if (ndo->ndo_qflag) {

ND_PRINT("tcp %u", length - hlen);

if (hlen > length) {

ND_PRINT(" [bad hdr length %u - too long, > %u]",

hlen, length);

goto invalid;

}

return;

}

flags = GET_U_1(tp->th_flags);

ND_PRINT("Flags [%s]", bittok2str_nosep(tcp_flag_values, "none", flags));

if (!ndo->ndo_Sflag && (flags & TH_ACK)) {

/*

* Find (or record) the initial sequence numbers for

* this conversation. (we pick an arbitrary

* collating order so there's only one entry for

* both directions).

*/

rev = 0;

if (ip6) {

struct tcp_seq_hash6 *th;

struct tcp_seq_hash6 *tcp_seq_hash;

const void *src, *dst;

struct tha6 tha;

tcp_seq_hash = tcp_seq_hash6;

src = (const void *)ip6->ip6_src;

dst = (const void *)ip6->ip6_dst;

if (sport > dport)

rev = 1;

else if (sport == dport) {

if (UNALIGNED_MEMCMP(src, dst, sizeof(ip6->ip6_dst)) > 0)

rev = 1;

}

if (rev) {

UNALIGNED_MEMCPY(&tha.src, dst, sizeof(ip6->ip6_dst));

UNALIGNED_MEMCPY(&tha.dst, src, sizeof(ip6->ip6_src));

tha.port = ((u_int)dport) << 16 | sport;

} else {

UNALIGNED_MEMCPY(&tha.dst, dst, sizeof(ip6->ip6_dst));

UNALIGNED_MEMCPY(&tha.src, src, sizeof(ip6->ip6_src));

tha.port = ((u_int)sport) << 16 | dport;

}

for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];

th->nxt; th = th->nxt)

if (memcmp((char *)&tha, (char *)&th->addr,

sizeof(th->addr)) == 0)

break;

if (!th->nxt || (flags & TH_SYN)) {

/* didn't find it or new conversation */

/* calloc() return used by the 'tcp_seq_hash6'

hash table: do not free() */

if (th->nxt == NULL) {

th->nxt = (struct tcp_seq_hash6 *)

calloc(1, sizeof(*th));

if (th->nxt == NULL)

(*ndo->ndo_error)(ndo,

S_ERR_ND_MEM_ALLOC,

"%s: calloc", __func__);

}

th->addr = tha;

if (rev)

th->ack = seq, th->seq = ack - 1;

else

th->seq = seq, th->ack = ack - 1;

} else {

if (rev)

seq -= th->ack, ack -= th->seq;

else

seq -= th->seq, ack -= th->ack;

}

thseq = th->seq;

thack = th->ack;

} else {

struct tcp_seq_hash *th;

struct tcp_seq_hash *tcp_seq_hash;

struct tha tha;

tcp_seq_hash = tcp_seq_hash4;

if (sport > dport)

rev = 1;

else if (sport == dport) {

if (UNALIGNED_MEMCMP(ip->ip_src, ip->ip_dst, sizeof(ip->ip_dst)) > 0)

rev = 1;

}

if (rev) {

UNALIGNED_MEMCPY(&tha.src, ip->ip_dst,

sizeof(ip->ip_dst));

UNALIGNED_MEMCPY(&tha.dst, ip->ip_src,

sizeof(ip->ip_src));

tha.port = ((u_int)dport) << 16 | sport;

} else {

UNALIGNED_MEMCPY(&tha.dst, ip->ip_dst,

sizeof(ip->ip_dst));

UNALIGNED_MEMCPY(&tha.src, ip->ip_src,

sizeof(ip->ip_src));

tha.port = ((u_int)sport) << 16 | dport;

}

for (th = &tcp_seq_hash[tha.port % TSEQ_HASHSIZE];

th->nxt; th = th->nxt)

if (memcmp((char *)&tha, (char *)&th->addr,

sizeof(th->addr)) == 0)

break;

if (!th->nxt || (flags & TH_SYN)) {

/* didn't find it or new conversation */

/* calloc() return used by the 'tcp_seq_hash4'

hash table: do not free() */

if (th->nxt == NULL) {

th->nxt = (struct tcp_seq_hash *)

calloc(1, sizeof(*th));

if (th->nxt == NULL)

(*ndo->ndo_error)(ndo,

S_ERR_ND_MEM_ALLOC,

"%s: calloc", __func__);

}

th->addr = tha;

if (rev)

th->ack = seq, th->seq = ack - 1;

else

th->seq = seq, th->ack = ack - 1;

} else {

if (rev)

seq -= th->ack, ack -= th->seq;

else

seq -= th->seq, ack -= th->ack;

}

thseq = th->seq;

thack = th->ack;

}

} else {

/*fool gcc*/

thseq = thack = rev = 0;

}

if (hlen > length) {

ND_PRINT(" [bad hdr length %u - too long, > %u]",

hlen, length);

goto invalid;

}

if (ndo->ndo_vflag && !ndo->ndo_Kflag && !fragmented) {

/* Check the checksum, if possible. */

uint16_t sum, tcp_sum;

if (IP_V(ip) == 4) {

if (ND_TTEST_LEN(tp->th_sport, length)) {

sum = tcp_cksum(ndo, ip, tp, length);

tcp_sum = GET_BE_U_2(tp->th_sum);

ND_PRINT(", cksum 0x%04x", tcp_sum);

if (sum != 0)

ND_PRINT(" (incorrect -> 0x%04x)",

in_cksum_shouldbe(tcp_sum, sum));

else

ND_PRINT(" (correct)");

}

} else if (IP_V(ip) == 6) {

if (ND_TTEST_LEN(tp->th_sport, length)) {

sum = tcp6_cksum(ndo, ip6, tp, length);

tcp_sum = GET_BE_U_2(tp->th_sum);

ND_PRINT(", cksum 0x%04x", tcp_sum);

if (sum != 0)

ND_PRINT(" (incorrect -> 0x%04x)",

in_cksum_shouldbe(tcp_sum, sum));

else

ND_PRINT(" (correct)");

}

}

}

length -= hlen;

if (ndo->ndo_vflag > 1 || length > 0 || flags & (TH_SYN | TH_FIN | TH_RST)) {

ND_PRINT(", seq %u", seq);

if (length > 0) {

ND_PRINT(":%u", seq + length);

}

}

if (flags & TH_ACK) {

ND_PRINT(", ack %u", ack);

}

ND_PRINT(", win %u", win);

if (flags & TH_URG)

ND_PRINT(", urg %u", urp);

/*

* Handle any options.

*/

if (hlen > sizeof(*tp)) {

const u_char *cp;

u_int i, opt, datalen;

u_int len;

hlen -= sizeof(*tp);

cp = (const u_char *)tp + sizeof(*tp);

ND_PRINT(", options [");

while (hlen > 0) {

if (ch != '\0')

ND_PRINT("%c", ch);

opt = GET_U_1(cp);

cp++;

if (ZEROLENOPT(opt))

len = 1;

else {

len = GET_U_1(cp);

cp++; /* total including type, len */

if (len < 2 || len > hlen)

goto bad;

--hlen; /* account for length byte */

}

--hlen; /* account for type byte */

datalen = 0;

/* Bail if "l" bytes of data are not left or were not captured */

#define LENCHECK(l) { if ((l) > hlen) goto bad; }

ND_PRINT("%s", tok2str(tcp_option_values, "unknown-%u", opt));

switch (opt) {

case TCPOPT_MAXSEG:

datalen = 2;

LENCHECK(datalen);

ND_PRINT(" %u", GET_BE_U_2(cp));

break;

case TCPOPT_WSCALE:

datalen = 1;

LENCHECK(datalen);

ND_PRINT(" %u", GET_U_1(cp));

break;

case TCPOPT_SACK:

datalen = len - 2;

if (datalen % 8 != 0) {

ND_PRINT(" invalid sack");

} else {

uint32_t s, e;

ND_PRINT(" %u ", datalen / 8);

for (i = 0; i < datalen; i += 8) {

LENCHECK(i + 4);

s = GET_BE_U_4(cp + i);

LENCHECK(i + 8);

e = GET_BE_U_4(cp + i + 4);

if (rev) {

s -= thseq;

e -= thseq;

} else {

s -= thack;

e -= thack;

}

ND_PRINT("{%u:%u}", s, e);

}

}

break;

case TCPOPT_CC:

case TCPOPT_CCNEW:

case TCPOPT_CCECHO:

case TCPOPT_ECHO:

case TCPOPT_ECHOREPLY:

/*

* those options share their semantics.

* fall through

*/

datalen = 4;

LENCHECK(datalen);

ND_PRINT(" %u", GET_BE_U_4(cp));

break;

case TCPOPT_TIMESTAMP:

datalen = 8;

LENCHECK(datalen);

ND_PRINT(" val %u ecr %u",

GET_BE_U_4(cp),

GET_BE_U_4(cp + 4));

break;

case TCPOPT_SIGNATURE:

datalen = TCP_SIGLEN;

LENCHECK(datalen);

ND_TCHECK_LEN(cp, datalen);

ND_PRINT(" ");

#ifdef HAVE_LIBCRYPTO

switch (tcp_verify_signature(ndo, ip, tp,

bp + TH_OFF(tp) * 4, length, cp)) {

case SIGNATURE_VALID:

ND_PRINT("valid");

break;

case SIGNATURE_INVALID:

nd_print_invalid(ndo);

break;

case CANT_CHECK_SIGNATURE:

ND_PRINT("can't check - ");

for (i = 0; i < TCP_SIGLEN; ++i)

ND_PRINT("%02x",

GET_U_1(cp + i));

break;

}

#else

for (i = 0; i < TCP_SIGLEN; ++i)

ND_PRINT("%02x", GET_U_1(cp + i));

#endif

break;

case TCPOPT_SCPS:

datalen = 2;

LENCHECK(datalen);

ND_PRINT(" cap %02x id %u", GET_U_1(cp),

GET_U_1(cp + 1));

break;

case TCPOPT_TCPAO:

datalen = len - 2;

/* RFC 5925 Section 2.2:

* "The Length value MUST be greater than or equal to 4."

* (This includes the Kind and Length fields already processed

* at this point.)

*/

if (datalen < 2) {

nd_print_invalid(ndo);

} else {

LENCHECK(1);

ND_PRINT(" keyid %u", GET_U_1(cp));

LENCHECK(2);

ND_PRINT(" rnextkeyid %u",

GET_U_1(cp + 1));

if (datalen > 2) {

ND_PRINT(" mac 0x");

for (i = 2; i < datalen; i++) {

LENCHECK(i + 1);

ND_PRINT("%02x",

GET_U_1(cp + i));

}

}

}

break;

case TCPOPT_EOL:

case TCPOPT_NOP:

case TCPOPT_SACKOK:

/*

* Nothing interesting.

* fall through

*/

break;

case TCPOPT_UTO:

datalen = 2;

LENCHECK(datalen);

utoval = GET_BE_U_2(cp);

ND_PRINT(" 0x%x", utoval);

if (utoval & 0x0001)

utoval = (utoval >> 1) * 60;

else

utoval >>= 1;

ND_PRINT(" %u", utoval);

break;

case TCPOPT_MPTCP:

{

const u_char *snapend_save;

int ret;

datalen = len - 2;

LENCHECK(datalen);

/* FIXME: Proof-read mptcp_print() and if it

* always covers all bytes when it returns 1,

* only do ND_TCHECK_LEN() if it returned 0.

*/

ND_TCHECK_LEN(cp, datalen);

/* Update the snapend to the end of the option

* before calling mptcp_print(). Some options

* (MPTCP or others) may be present after a

* MPTCP option. This prevents that, in

* mptcp_print(), the remaining length < the

* remaining caplen.

*/

snapend_save = ndo->ndo_snapend;

ndo->ndo_snapend = ND_MIN(cp - 2 + len,

ndo->ndo_snapend);

ret = mptcp_print(ndo, cp - 2, len, flags);

ndo->ndo_snapend = snapend_save;

if (!ret)

goto bad;

break;

}

case TCPOPT_FASTOPEN:

datalen = len - 2;

LENCHECK(datalen);

ND_TCHECK_LEN(cp, datalen);

ND_PRINT(" ");

print_tcp_fastopen_option(ndo, cp, datalen);

break;

case TCPOPT_EXPERIMENT2:

datalen = len - 2;

LENCHECK(datalen);

ND_TCHECK_LEN(cp, datalen);

if (datalen < 2)

goto bad;

/* RFC6994 */

magic = GET_BE_U_2(cp);

ND_PRINT("-");

switch(magic) {

case 0xf989: /* TCP Fast Open RFC 7413 */

ND_PRINT("tfo");

print_tcp_fastopen_option(ndo, cp + 2, datalen - 2);

break;

default:

/* Unknown magic number */

ND_PRINT("%04x", magic);

break;

}

break;

default:

datalen = len - 2;

if (datalen)

ND_PRINT(" 0x");

for (i = 0; i < datalen; ++i) {

LENCHECK(i + 1);

ND_PRINT("%02x", GET_U_1(cp + i));

}

break;

}

/* Account for data printed */

cp += datalen;

hlen -= datalen;

/* Check specification against observed length */

++datalen; /* option octet */

if (!ZEROLENOPT(opt))

++datalen; /* size octet */

if (datalen != len)

ND_PRINT("[len %u]", len);

ch = ',';

if (opt == TCPOPT_EOL)

break;

}

ND_PRINT("]");

}

/*

* Print length field before crawling down the stack.

*/

ND_PRINT(", length %u", length);

if (length == 0)

return;

/*

* Decode payload if necessary.

*/

header_len = TH_OFF(tp) * 4;

/*

* Do a bounds check before decoding the payload.

* At least the header data is required.

*/

if (!ND_TTEST_LEN(bp, header_len)) {

ND_PRINT(" [remaining caplen(%u) < header length(%u)]",

ND_BYTES_AVAILABLE_AFTER(bp), header_len);

nd_trunc_longjmp(ndo);

}

bp += header_len;

if ((flags & TH_RST) && ndo->ndo_vflag) {

print_tcp_rst_data(ndo, bp, length);

return;

}

if (ndo->ndo_packettype) {

switch (ndo->ndo_packettype) {

case PT_ZMTP1:

zmtp1_print(ndo, bp, length);

break;

case PT_RESP:

resp_print(ndo, bp, length);

break;

case PT_DOMAIN:

/* over_tcp: TRUE, is_mdns: FALSE */

domain_print(ndo, bp, length, TRUE, FALSE);

break;

}

return;

}

if (IS_SRC_OR_DST_PORT(TELNET_PORT)) {

telnet_print(ndo, bp, length);

} else if (IS_SRC_OR_DST_PORT(SMTP_PORT)) {

ND_PRINT(": ");

smtp_print(ndo, bp, length);

} else if (IS_SRC_OR_DST_PORT(WHOIS_PORT)) {

ND_PRINT(": ");

whois_print(ndo, bp, length);

} else if (IS_SRC_OR_DST_PORT(BGP_PORT))

bgp_print(ndo, bp, length);

else if (IS_SRC_OR_DST_PORT(PPTP_PORT))

pptp_print(ndo, bp);

else if (IS_SRC_OR_DST_PORT(REDIS_PORT))

resp_print(ndo, bp, length);

else if (IS_SRC_OR_DST_PORT(SSH_PORT))

ssh_print(ndo, bp, length);

#ifdef ENABLE_SMB

else if (IS_SRC_OR_DST_PORT(NETBIOS_SSN_PORT))

nbt_tcp_print(ndo, bp, length);

else if (IS_SRC_OR_DST_PORT(SMB_PORT))

smb_tcp_print(ndo, bp, length);

#endif

else if (IS_SRC_OR_DST_PORT(BEEP_PORT))

beep_print(ndo, bp, length);

else if (IS_SRC_OR_DST_PORT(OPENFLOW_PORT_OLD) || IS_SRC_OR_DST_PORT(OPENFLOW_PORT_IANA))

openflow_print(ndo, bp, length);

else if (IS_SRC_OR_DST_PORT(FTP_PORT)) {

ND_PRINT(": ");

ftp_print(ndo, bp, length);

} else if (IS_SRC_OR_DST_PORT(HTTP_PORT) || IS_SRC_OR_DST_PORT(HTTP_PORT_ALT)) {

ND_PRINT(": ");

http_print(ndo, bp, length);

} else if (IS_SRC_OR_DST_PORT(RTSP_PORT) || IS_SRC_OR_DST_PORT(RTSP_PORT_ALT)) {

ND_PRINT(": ");

rtsp_print(ndo, bp, length);

} else if (IS_SRC_OR_DST_PORT(NAMESERVER_PORT)) {

/* over_tcp: TRUE, is_mdns: FALSE */

domain_print(ndo, bp, length, TRUE, FALSE);

} else if (IS_SRC_OR_DST_PORT(MSDP_PORT)) {

msdp_print(ndo, bp, length);

} else if (IS_SRC_OR_DST_PORT(RPKI_RTR_PORT)) {

rpki_rtr_print(ndo, bp, length);

} else if (IS_SRC_OR_DST_PORT(LDP_PORT)) {

ldp_print(ndo, bp, length);

} else if ((IS_SRC_OR_DST_PORT(NFS_PORT)) &&

length >= 4) {

/*

* If data present, header length valid, and NFS port used,

* assume NFS.

* Pass offset of data plus 4 bytes for RPC TCP msg length

* to NFS print routines.

*/

uint32_t fraglen;

const struct sunrpc_msg *rp;

enum sunrpc_msg_type direction;

fraglen = GET_BE_U_4(bp) & 0x7FFFFFFF;

if (fraglen > (length) - 4)

fraglen = (length) - 4;

rp = (const struct sunrpc_msg *)(bp + 4);

if (ND_TTEST_4(rp->rm_direction)) {

direction = (enum sunrpc_msg_type) GET_BE_U_4(rp->rm_direction);

if (dport == NFS_PORT && direction == SUNRPC_CALL) {

ND_PRINT(": NFS request xid %u ",

GET_BE_U_4(rp->rm_xid));

nfsreq_noaddr_print(ndo, (const u_char *)rp, fraglen, (const u_char *)ip);

return;

}

if (sport == NFS_PORT && direction == SUNRPC_REPLY) {

ND_PRINT(": NFS reply xid %u ",

GET_BE_U_4(rp->rm_xid));

nfsreply_noaddr_print(ndo, (const u_char *)rp, fraglen, (const u_char *)ip);

return;

}

}

}

return;

bad:

ND_PRINT("[bad opt]");

if (ch != '\0')

ND_PRINT("]");

return;

invalid:

nd_print_invalid(ndo);

}

/*

* RFC1122 says the following on data in RST segments:

*

* 4.2.2.12 RST Segment: RFC-793 Section 3.4

*

* A TCP SHOULD allow a received RST segment to include data.

*

* DISCUSSION

* It has been suggested that a RST segment could contain

* ASCII text that encoded and explained the cause of the

* RST. No standard has yet been established for such

* data.

*

*/

static void

print_tcp_rst_data(netdissect_options *ndo,

const u_char *sp, u_int length)

{

ND_PRINT(ND_TTEST_LEN(sp, length) ? " [RST" : " [!RST");

if (length > MAX_RST_DATA_LEN) {

length = MAX_RST_DATA_LEN; /* can use -X for longer */

ND_PRINT("+"); /* indicate we truncate */

}

ND_PRINT(" ");

(void)nd_printn(ndo, sp, length, ndo->ndo_snapend);

ND_PRINT("]");

}

static void

print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp,

u_int datalen)

{

u_int i;

if (datalen == 0) {

/* Fast Open Cookie Request */

ND_PRINT(" cookiereq");

} else {

/* Fast Open Cookie */

if (datalen % 2 != 0 || datalen < 4 || datalen > 16) {

nd_print_invalid(ndo);

} else {

ND_PRINT(" cookie ");

for (i = 0; i < datalen; ++i)

ND_PRINT("%02x", GET_U_1(cp + i));

}

}

}

#ifdef HAVE_LIBCRYPTO

DIAG_OFF_DEPRECATION

static int

tcp_verify_signature(netdissect_options *ndo,

const struct ip *ip, const struct tcphdr *tp,

const u_char *data, u_int length, const u_char *rcvsig)

{

struct tcphdr tp1;

u_char sig[TCP_SIGLEN];

char zero_proto = 0;

MD5_CTX ctx;

uint16_t savecsum, tlen;

const struct ip6_hdr *ip6;

uint32_t len32;

uint8_t nxt;

if (!ND_TTEST_LEN(data, length)) {

ND_PRINT("snaplen too short, ");

return (CANT_CHECK_SIGNATURE);

}

tp1 = *tp;

if (ndo->ndo_sigsecret == NULL) {

ND_PRINT("shared secret not supplied with -M, ");

return (CANT_CHECK_SIGNATURE);

}

MD5_Init(&ctx);

/*

* Step 1: Update MD5 hash with IP pseudo-header.

*/

if (IP_V(ip) == 4) {

MD5_Update(&ctx, (const char *)&ip->ip_src, sizeof(ip->ip_src));

MD5_Update(&ctx, (const char *)&ip->ip_dst, sizeof(ip->ip_dst));

MD5_Update(&ctx, (const char *)&zero_proto, sizeof(zero_proto));

MD5_Update(&ctx, (const char *)&ip->ip_p, sizeof(ip->ip_p));

tlen = GET_BE_U_2(ip->ip_len) - IP_HL(ip) * 4;

tlen = htons(tlen);

MD5_Update(&ctx, (const char *)&tlen, sizeof(tlen));

} else if (IP_V(ip) == 6) {

ip6 = (const struct ip6_hdr *)ip;

MD5_Update(&ctx, (const char *)&ip6->ip6_src, sizeof(ip6->ip6_src));

MD5_Update(&ctx, (const char *)&ip6->ip6_dst, sizeof(ip6->ip6_dst));

len32 = htonl(GET_BE_U_2(ip6->ip6_plen));

MD5_Update(&ctx, (const char *)&len32, sizeof(len32));

nxt = 0;

MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));

MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));

MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));

nxt = IPPROTO_TCP;

MD5_Update(&ctx, (const char *)&nxt, sizeof(nxt));

} else {

ND_PRINT("IP version not 4 or 6, ");

return (CANT_CHECK_SIGNATURE);

}

/*

* Step 2: Update MD5 hash with TCP header, excluding options.

* The TCP checksum must be set to zero.

*/

memcpy(&savecsum, tp1.th_sum, sizeof(savecsum));

memset(tp1.th_sum, 0, sizeof(tp1.th_sum));

MD5_Update(&ctx, (const char *)&tp1, sizeof(struct tcphdr));

memcpy(tp1.th_sum, &savecsum, sizeof(tp1.th_sum));

/*

* Step 3: Update MD5 hash with TCP segment data, if present.

*/

if (length > 0)

MD5_Update(&ctx, data, length);

/*

* Step 4: Update MD5 hash with shared secret.

*/

MD5_Update(&ctx, ndo->ndo_sigsecret, strlen(ndo->ndo_sigsecret));

MD5_Final(sig, &ctx);

if (memcmp(rcvsig, sig, TCP_SIGLEN) == 0)

return (SIGNATURE_VALID);

else

return (SIGNATURE_INVALID);

}

DIAG_ON_DEPRECATION

#endif /* HAVE_LIBCRYPTO */