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

/* 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 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: print-tcp.c,v 1.12 2024/09/02 16:15:33 christos Exp $");
#endif

#include <config.h>

#include "netdissect-stdinc.h"

#include <stdlib.h>
#include <string.h>

#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, int exp);

#define MAX_RST_DATA_LEN 30

struct tha {
nd_ipv4 src;
nd_ipv4 dst;
u_int port;
};

struct tcp_seq_hash {
struct tcp_seq_hash *nxt;
struct tha addr;
uint32_t seq;
uint32_t ack;
};

struct tha6 {
nd_ipv6 src;
nd_ipv6 dst;
u_int port;
};

struct tcp_seq_hash6 {
struct tcp_seq_hash6 *nxt;
struct tha6 addr;
uint32_t seq;
uint32_t ack;
};

#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];

static 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, "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);
}

UNALIGNED_OK
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_print_trunc(ndo);
return;
}

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));
}
}

ND_TCHECK_SIZE(tp);

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));
return;
}

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);
}
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);
return;
}

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_TCHECK_LEN(cp, l); }

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_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);
/* 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_PRINT(" ");
print_tcp_fastopen_option(ndo, cp, datalen, FALSE);
break;

case TCPOPT_EXPERIMENT2:
datalen = len - 2;
LENCHECK(datalen);
if (datalen < 2)
goto bad;
/* RFC6994 */
magic = GET_BE_U_2(cp);
ND_PRINT("-");

switch(magic) {

case 0xf989: /* TCP Fast Open RFC 7413 */
print_tcp_fastopen_option(ndo, cp + 2, datalen - 2, TRUE);
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(FTP_PORT)) {
ND_PRINT(": ");
ftp_print(ndo, bp, length);
} else if (IS_SRC_OR_DST_PORT(SSH_PORT)) {
ssh_print(ndo, bp, length);
} else 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(NAMESERVER_PORT)) {
/* over_tcp: TRUE, is_mdns: FALSE */
domain_print(ndo, bp, length, TRUE, FALSE);
} else if (IS_SRC_OR_DST_PORT(HTTP_PORT)) {
ND_PRINT(": ");
http_print(ndo, bp, length);
#ifdef ENABLE_SMB
} else if (IS_SRC_OR_DST_PORT(NETBIOS_SSN_PORT)) {
nbt_tcp_print(ndo, bp, length);
#endif
} else if (IS_SRC_OR_DST_PORT(BGP_PORT)) {
bgp_print(ndo, bp, length);
} else if (IS_SRC_OR_DST_PORT(RPKI_RTR_PORT)) {
rpki_rtr_print(ndo, bp, length);
#ifdef ENABLE_SMB
} else if (IS_SRC_OR_DST_PORT(SMB_PORT)) {
smb_tcp_print(ndo, bp, length);
#endif
} else if (IS_SRC_OR_DST_PORT(RTSP_PORT)) {
ND_PRINT(": ");
rtsp_print(ndo, bp, length);
} else if (IS_SRC_OR_DST_PORT(MSDP_PORT)) {
msdp_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(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(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(HTTP_PORT_ALT)) {
ND_PRINT(": ");
http_print(ndo, bp, length);
} else if (IS_SRC_OR_DST_PORT(RTSP_PORT_ALT)) {
ND_PRINT(": ");
rtsp_print(ndo, bp, length);
} else if ((IS_SRC_OR_DST_PORT(NFS_PORT)) &&
length >= 4 && ND_TTEST_4(bp)) {
/*
* 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;
trunc:
nd_print_trunc(ndo);
if (ch != '\0')
ND_PRINT(">");
}

/*
* 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)
{
u_char c;

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(" ");
while (length && sp < ndo->ndo_snapend) {
c = GET_U_1(sp);
sp++;
fn_print_char(ndo, c);
length--;
}
ND_PRINT("]");
}

static void
print_tcp_fastopen_option(netdissect_options *ndo, const u_char *cp,
u_int datalen, int exp)
{
u_int i;

if (exp)
ND_PRINT("tfo");

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 (data + length > ndo->ndo_snapend) {
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 */