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/*
* Copyright (c) 1989, 1990, 1991, 1993, 1994, 1995, 1996, 1997
* The Regents of the University of California. All rights reserved.
*
* 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: Compressed Serial Line Internet Protocol printer */
#include <config.h>
#include "netdissect-stdinc.h"
#define ND_LONGJMP_FROM_TCHECK
#include "netdissect.h"
#include "extract.h"
#include "ip.h"
#include "tcp.h"
#include "slcompress.h"
/*
* definitions of the pseudo- link-level header attached to slip
* packets grabbed by the packet filter (bpf) traffic monitor.
*/
#define SLIP_HDRLEN 16
#define SLX_DIR 0
#define SLX_CHDR 1
#define SLIPDIR_IN 0
#define SLIPDIR_OUT 1
static u_int lastlen[2][256];
static u_int lastconn = 255;
static void sliplink_print(netdissect_options *, const u_char *, const struct ip *, u_int);
static void compressed_sl_print(netdissect_options *, const u_char *, const struct ip *, u_int, int);
void
sl_if_print(netdissect_options *ndo,
const struct pcap_pkthdr *h, const u_char *p)
{
u_int length = h->len;
const struct ip *ip;
ndo->ndo_protocol = "slip";
ND_TCHECK_LEN(p, SLIP_HDRLEN);
ndo->ndo_ll_hdr_len += SLIP_HDRLEN;
length -= SLIP_HDRLEN;
ip = (const struct ip *)(p + SLIP_HDRLEN);
if (ndo->ndo_eflag)
sliplink_print(ndo, p, ip, length);
switch (IP_V(ip)) {
case 4:
ip_print(ndo, (const u_char *)ip, length);
break;
case 6:
ip6_print(ndo, (const u_char *)ip, length);
break;
default:
ND_PRINT("ip v%u", IP_V(ip));
}
}
void
sl_bsdos_if_print(netdissect_options *ndo,
const struct pcap_pkthdr *h, const u_char *p)
{
u_int length = h->len;
const struct ip *ip;
ndo->ndo_protocol = "slip_bsdos";
ND_TCHECK_LEN(p, SLIP_HDRLEN);
ndo->ndo_ll_hdr_len += SLIP_HDRLEN;
length -= SLIP_HDRLEN;
ip = (const struct ip *)(p + SLIP_HDRLEN);
#ifdef notdef
if (ndo->ndo_eflag)
sliplink_print(ndo, p, ip, length);
#endif
ip_print(ndo, (const u_char *)ip, length);
}
static void
sliplink_print(netdissect_options *ndo,
const u_char *p, const struct ip *ip,
u_int length)
{
int dir;
u_int hlen;
dir = GET_U_1(p + SLX_DIR);
switch (dir) {
case SLIPDIR_IN:
ND_PRINT("I ");
break;
case SLIPDIR_OUT:
ND_PRINT("O ");
break;
default:
ND_PRINT("Invalid direction %d ", dir);
dir = -1;
break;
}
switch (GET_U_1(p + SLX_CHDR) & 0xf0) {
case TYPE_IP:
ND_PRINT("ip %u: ", length + SLIP_HDRLEN);
break;
case TYPE_UNCOMPRESSED_TCP:
/*
* The connection id is stored in the IP protocol field.
* Get it from the link layer since sl_uncompress_tcp()
* has restored the IP header copy to IPPROTO_TCP.
*/
lastconn = GET_U_1(((const struct ip *)(p + SLX_CHDR))->ip_p);
ND_PRINT("utcp %u: ", lastconn);
if (dir == -1) {
/* Direction is bogus, don't use it */
return;
}
ND_TCHECK_SIZE(ip);
hlen = IP_HL(ip);
ND_TCHECK_SIZE((const struct tcphdr *)&((const int *)ip)[hlen]);
hlen += TH_OFF((const struct tcphdr *)&((const int *)ip)[hlen]);
lastlen[dir][lastconn] = length - (hlen << 2);
break;
default:
if (dir == -1) {
/* Direction is bogus, don't use it */
return;
}
if (GET_U_1(p + SLX_CHDR) & TYPE_COMPRESSED_TCP) {
compressed_sl_print(ndo, p + SLX_CHDR, ip, length, dir);
ND_PRINT(": ");
} else
ND_PRINT("slip-%u!: ", GET_U_1(p + SLX_CHDR));
}
}
static const u_char *
print_sl_change(netdissect_options *ndo,
const char *str, const u_char *cp)
{
u_int i;
if ((i = GET_U_1(cp)) == 0) {
cp++;
i = GET_BE_U_2(cp);
cp += 2;
}
ND_PRINT(" %s%u", str, i);
return (cp);
}
static const u_char *
print_sl_winchange(netdissect_options *ndo,
const u_char *cp)
{
int16_t i;
if ((i = GET_U_1(cp)) == 0) {
cp++;
i = GET_BE_S_2(cp);
cp += 2;
}
if (i >= 0)
ND_PRINT(" W+%d", i);
else
ND_PRINT(" W%d", i);
return (cp);
}
static void
compressed_sl_print(netdissect_options *ndo,
const u_char *chdr, const struct ip *ip,
u_int length, int dir)
{
const u_char *cp = chdr;
u_int flags, hlen;
flags = GET_U_1(cp);
cp++;
if (flags & NEW_C) {
lastconn = GET_U_1(cp);
cp++;
ND_PRINT("ctcp %u", lastconn);
} else
ND_PRINT("ctcp *");
/* skip tcp checksum */
cp += 2;
switch (flags & SPECIALS_MASK) {
case SPECIAL_I:
ND_PRINT(" *SA+%u", lastlen[dir][lastconn]);
break;
case SPECIAL_D:
ND_PRINT(" *S+%u", lastlen[dir][lastconn]);
break;
default:
if (flags & NEW_U)
cp = print_sl_change(ndo, "U=", cp);
if (flags & NEW_W)
cp = print_sl_winchange(ndo, cp);
if (flags & NEW_A)
cp = print_sl_change(ndo, "A+", cp);
if (flags & NEW_S)
cp = print_sl_change(ndo, "S+", cp);
break;
}
if (flags & NEW_I)
cp = print_sl_change(ndo, "I+", cp);
/*
* 'hlen' is the length of the uncompressed TCP/IP header (in words).
* 'cp - chdr' is the length of the compressed header.
* 'length - hlen' is the amount of data in the packet.
*/
ND_TCHECK_SIZE(ip);
hlen = IP_HL(ip);
ND_TCHECK_SIZE((const struct tcphdr *)&((const int32_t *)ip)[hlen]);
hlen += TH_OFF((const struct tcphdr *)&((const int32_t *)ip)[hlen]);
lastlen[dir][lastconn] = length - (hlen << 2);
ND_PRINT(" %u (%ld)", lastlen[dir][lastconn], (long)(cp - chdr));
}
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