05ec607970
the old one: an unnecessary define (KLD_MODULE) has been deleted and the initialisation of the module is done after domaininit was called to be sure inet is running. Some slight changed were made to ip_auth.c and ip_state.c in order to assure including of sys/systm.h in case we make a kld Make sure ip_fil does nmot include osreldate in kernel mode Remove mlfk_ipl.c from here: no sources allowed in these directories!
1106 lines
26 KiB
C
1106 lines
26 KiB
C
/*
|
|
* Copyright (C) 1995-1998 by Darren Reed.
|
|
*
|
|
* Redistribution and use in source and binary forms are permitted
|
|
* provided that this notice is preserved and due credit is given
|
|
* to the original author and the contributors.
|
|
*/
|
|
#if !defined(lint)
|
|
static const char sccsid[] = "@(#)ip_state.c 1.8 6/5/96 (C) 1993-1995 Darren Reed";
|
|
/*static const char rcsid[] = "@(#)$Id: ip_state.c,v 2.3.2.9 1999/10/21 14:31:09 darrenr Exp $";*/
|
|
static const char rcsid[] = "@(#)$FreeBSD$";
|
|
#endif
|
|
|
|
#include <sys/errno.h>
|
|
#include <sys/types.h>
|
|
#include <sys/param.h>
|
|
#include <sys/file.h>
|
|
#if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \
|
|
defined(_KERNEL)
|
|
# include "opt_ipfilter_log.h"
|
|
#endif
|
|
#if !defined(_KERNEL) && !defined(KERNEL) && !defined(__KERNEL__)
|
|
# include <stdio.h>
|
|
# include <stdlib.h>
|
|
# include <string.h>
|
|
#else
|
|
# ifdef linux
|
|
# include <linux/kernel.h>
|
|
# include <linux/module.h>
|
|
# endif
|
|
#endif
|
|
#if defined(KERNEL) && (__FreeBSD_version >= 220000)
|
|
# include <sys/filio.h>
|
|
# include <sys/fcntl.h>
|
|
# if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM)
|
|
# include "opt_ipfilter.h"
|
|
# endif
|
|
#else
|
|
# include <sys/ioctl.h>
|
|
#endif
|
|
#include <sys/time.h>
|
|
#include <sys/uio.h>
|
|
#ifndef linux
|
|
# include <sys/protosw.h>
|
|
#endif
|
|
#include <sys/socket.h>
|
|
#if (defined(_KERNEL) || defined(KERNEL)) && !defined(linux)
|
|
# include <sys/systm.h>
|
|
#endif
|
|
#if !defined(__SVR4) && !defined(__svr4__)
|
|
# ifndef linux
|
|
# include <sys/mbuf.h>
|
|
# endif
|
|
#else
|
|
# include <sys/filio.h>
|
|
# include <sys/byteorder.h>
|
|
# ifdef _KERNEL
|
|
# include <sys/dditypes.h>
|
|
# endif
|
|
# include <sys/stream.h>
|
|
# include <sys/kmem.h>
|
|
#endif
|
|
|
|
#include <net/if.h>
|
|
#ifdef sun
|
|
# include <net/af.h>
|
|
#endif
|
|
#include <net/route.h>
|
|
#include <netinet/in.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/tcp.h>
|
|
#ifndef linux
|
|
# include <netinet/ip_var.h>
|
|
# include <netinet/tcp_fsm.h>
|
|
#endif
|
|
#include <netinet/udp.h>
|
|
#include <netinet/ip_icmp.h>
|
|
#include "netinet/ip_compat.h"
|
|
#include <netinet/tcpip.h>
|
|
#include "netinet/ip_fil.h"
|
|
#include "netinet/ip_nat.h"
|
|
#include "netinet/ip_frag.h"
|
|
#include "netinet/ip_proxy.h"
|
|
#include "netinet/ip_state.h"
|
|
#if (__FreeBSD_version >= 300000)
|
|
# include <sys/malloc.h>
|
|
# if (defined(_KERNEL) || defined(KERNEL)) && !defined(IPFILTER_LKM)
|
|
# include <sys/libkern.h>
|
|
# include <sys/systm.h>
|
|
# endif
|
|
#endif
|
|
|
|
#ifndef MIN
|
|
# define MIN(a,b) (((a)<(b))?(a):(b))
|
|
#endif
|
|
|
|
#define TCP_CLOSE (TH_FIN|TH_RST)
|
|
|
|
static ipstate_t **ips_table = NULL;
|
|
static int ips_num = 0;
|
|
static ips_stat_t ips_stats;
|
|
#if (SOLARIS || defined(__sgi)) && defined(_KERNEL)
|
|
extern KRWLOCK_T ipf_state, ipf_mutex;
|
|
extern kmutex_t ipf_rw;
|
|
#endif
|
|
|
|
static int fr_matchsrcdst __P((ipstate_t *, struct in_addr, struct in_addr,
|
|
fr_info_t *, tcphdr_t *));
|
|
static frentry_t *fr_checkicmpmatchingstate __P((ip_t *, fr_info_t *));
|
|
static int fr_state_flush __P((int));
|
|
static ips_stat_t *fr_statetstats __P((void));
|
|
static void fr_delstate __P((ipstate_t *));
|
|
|
|
|
|
#define FIVE_DAYS (2 * 5 * 86400) /* 5 days: half closed session */
|
|
|
|
#define TCP_MSL 240 /* 2 minutes */
|
|
u_long fr_tcpidletimeout = FIVE_DAYS,
|
|
fr_tcpclosewait = 2 * TCP_MSL,
|
|
fr_tcplastack = 2 * TCP_MSL,
|
|
fr_tcptimeout = 2 * TCP_MSL,
|
|
fr_tcpclosed = 1,
|
|
fr_udptimeout = 240,
|
|
fr_icmptimeout = 120;
|
|
int fr_statemax = IPSTATE_MAX,
|
|
fr_statesize = IPSTATE_SIZE;
|
|
int fr_state_doflush = 0;
|
|
|
|
|
|
int fr_stateinit()
|
|
{
|
|
KMALLOCS(ips_table, ipstate_t **, fr_statesize * sizeof(ipstate_t *));
|
|
if (ips_table != NULL)
|
|
bzero((char *)ips_table, fr_statesize * sizeof(ipstate_t *));
|
|
else
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
|
|
static ips_stat_t *fr_statetstats()
|
|
{
|
|
ips_stats.iss_active = ips_num;
|
|
ips_stats.iss_table = ips_table;
|
|
return &ips_stats;
|
|
}
|
|
|
|
|
|
/*
|
|
* flush state tables. two actions currently defined:
|
|
* which == 0 : flush all state table entries
|
|
* which == 1 : flush TCP connections which have started to close but are
|
|
* stuck for some reason.
|
|
*/
|
|
static int fr_state_flush(which)
|
|
int which;
|
|
{
|
|
register int i;
|
|
register ipstate_t *is, **isp;
|
|
#if defined(_KERNEL) && !SOLARIS
|
|
int s;
|
|
#endif
|
|
int delete, removed = 0;
|
|
|
|
SPL_NET(s);
|
|
WRITE_ENTER(&ipf_state);
|
|
for (i = fr_statesize - 1; i >= 0; i--)
|
|
for (isp = &ips_table[i]; (is = *isp); ) {
|
|
delete = 0;
|
|
|
|
switch (which)
|
|
{
|
|
case 0 :
|
|
delete = 1;
|
|
break;
|
|
case 1 :
|
|
if ((is->is_p == IPPROTO_TCP) &&
|
|
(((is->is_state[0] <= TCPS_ESTABLISHED) &&
|
|
(is->is_state[1] > TCPS_ESTABLISHED)) ||
|
|
((is->is_state[1] <= TCPS_ESTABLISHED) &&
|
|
(is->is_state[0] > TCPS_ESTABLISHED))))
|
|
delete = 1;
|
|
break;
|
|
}
|
|
|
|
if (delete) {
|
|
*isp = is->is_next;
|
|
if (is->is_p == IPPROTO_TCP)
|
|
ips_stats.iss_fin++;
|
|
else
|
|
ips_stats.iss_expire++;
|
|
if (ips_table[i] == NULL)
|
|
ips_stats.iss_inuse--;
|
|
#ifdef IPFILTER_LOG
|
|
ipstate_log(is, ISL_FLUSH);
|
|
#endif
|
|
fr_delstate(is);
|
|
ips_num--;
|
|
removed++;
|
|
} else
|
|
isp = &is->is_next;
|
|
}
|
|
if (fr_state_doflush) {
|
|
(void) fr_state_flush(1);
|
|
fr_state_doflush = 0;
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
SPL_X(s);
|
|
return removed;
|
|
}
|
|
|
|
|
|
int fr_state_ioctl(data, cmd, mode)
|
|
caddr_t data;
|
|
#if defined(__NetBSD__) || defined(__OpenBSD__)
|
|
u_long cmd;
|
|
#else
|
|
int cmd;
|
|
#endif
|
|
int mode;
|
|
{
|
|
int arg, ret, error = 0;
|
|
|
|
switch (cmd)
|
|
{
|
|
case SIOCIPFFL :
|
|
IRCOPY(data, (caddr_t)&arg, sizeof(arg));
|
|
if (arg == 0 || arg == 1) {
|
|
ret = fr_state_flush(arg);
|
|
IWCOPY((caddr_t)&ret, data, sizeof(ret));
|
|
} else
|
|
error = EINVAL;
|
|
break;
|
|
case SIOCGIPST :
|
|
IWCOPY((caddr_t)fr_statetstats(), data, sizeof(ips_stat_t));
|
|
break;
|
|
case FIONREAD :
|
|
#ifdef IPFILTER_LOG
|
|
IWCOPY((caddr_t)&iplused[IPL_LOGSTATE], (caddr_t)data,
|
|
sizeof(iplused[IPL_LOGSTATE]));
|
|
#endif
|
|
break;
|
|
default :
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
|
|
/*
|
|
* Create a new ipstate structure and hang it off the hash table.
|
|
*/
|
|
ipstate_t *fr_addstate(ip, fin, flags)
|
|
ip_t *ip;
|
|
fr_info_t *fin;
|
|
u_int flags;
|
|
{
|
|
register ipstate_t *is;
|
|
register u_int hv;
|
|
ipstate_t ips;
|
|
u_int pass;
|
|
|
|
if ((ip->ip_off & IP_OFFMASK) || (fin->fin_fi.fi_fl & FI_SHORT))
|
|
return NULL;
|
|
if (ips_num == fr_statemax) {
|
|
ips_stats.iss_max++;
|
|
fr_state_doflush = 1;
|
|
return NULL;
|
|
}
|
|
is = &ips;
|
|
bzero((char *)is, sizeof(*is));
|
|
ips.is_age = 1;
|
|
ips.is_state[0] = 0;
|
|
ips.is_state[1] = 0;
|
|
/*
|
|
* Copy and calculate...
|
|
*/
|
|
hv = (is->is_p = ip->ip_p);
|
|
hv += (is->is_src.s_addr = ip->ip_src.s_addr);
|
|
hv += (is->is_dst.s_addr = ip->ip_dst.s_addr);
|
|
|
|
switch (ip->ip_p)
|
|
{
|
|
case IPPROTO_ICMP :
|
|
{
|
|
struct icmp *ic = (struct icmp *)fin->fin_dp;
|
|
|
|
switch (ic->icmp_type)
|
|
{
|
|
case ICMP_ECHO :
|
|
is->is_icmp.ics_type = ICMP_ECHOREPLY; /* XXX */
|
|
hv += (is->is_icmp.ics_id = ic->icmp_id);
|
|
hv += (is->is_icmp.ics_seq = ic->icmp_seq);
|
|
break;
|
|
case ICMP_TSTAMP :
|
|
case ICMP_IREQ :
|
|
case ICMP_MASKREQ :
|
|
is->is_icmp.ics_type = ic->icmp_type + 1;
|
|
break;
|
|
default :
|
|
return NULL;
|
|
}
|
|
ATOMIC_INC(ips_stats.iss_icmp);
|
|
is->is_age = fr_icmptimeout;
|
|
break;
|
|
}
|
|
case IPPROTO_TCP :
|
|
{
|
|
register tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp;
|
|
|
|
/*
|
|
* The endian of the ports doesn't matter, but the ack and
|
|
* sequence numbers do as we do mathematics on them later.
|
|
*/
|
|
is->is_dport = tcp->th_dport;
|
|
is->is_sport = tcp->th_sport;
|
|
if ((flags & (FI_W_DPORT|FI_W_SPORT)) == 0) {
|
|
hv += tcp->th_dport;
|
|
hv += tcp->th_sport;
|
|
}
|
|
if (tcp->th_seq != 0) {
|
|
is->is_send = ntohl(tcp->th_seq) + ip->ip_len -
|
|
fin->fin_hlen - (tcp->th_off << 2) +
|
|
((tcp->th_flags & TH_SYN) ? 1 : 0) +
|
|
((tcp->th_flags & TH_FIN) ? 1 : 0);
|
|
is->is_maxsend = is->is_send + 1;
|
|
}
|
|
is->is_dend = 0;
|
|
is->is_maxswin = ntohs(tcp->th_win);
|
|
if (is->is_maxswin == 0)
|
|
is->is_maxswin = 1;
|
|
/*
|
|
* If we're creating state for a starting connection, start the
|
|
* timer on it as we'll never see an error if it fails to
|
|
* connect.
|
|
*/
|
|
MUTEX_ENTER(&ipf_rw);
|
|
ips_stats.iss_tcp++;
|
|
fr_tcp_age(&is->is_age, is->is_state, ip, fin,
|
|
tcp->th_sport == is->is_sport);
|
|
MUTEX_EXIT(&ipf_rw);
|
|
break;
|
|
}
|
|
case IPPROTO_UDP :
|
|
{
|
|
register tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp;
|
|
|
|
if ((flags & (FI_W_DPORT|FI_W_SPORT)) == 0) {
|
|
hv += (is->is_dport = tcp->th_dport);
|
|
hv += (is->is_sport = tcp->th_sport);
|
|
}
|
|
ATOMIC_INC(ips_stats.iss_udp);
|
|
is->is_age = fr_udptimeout;
|
|
break;
|
|
}
|
|
default :
|
|
return NULL;
|
|
}
|
|
|
|
KMALLOC(is, ipstate_t *);
|
|
if (is == NULL) {
|
|
ATOMIC_INC(ips_stats.iss_nomem);
|
|
return NULL;
|
|
}
|
|
bcopy((char *)&ips, (char *)is, sizeof(*is));
|
|
hv %= fr_statesize;
|
|
RW_UPGRADE(&ipf_mutex);
|
|
is->is_rule = fin->fin_fr;
|
|
if (is->is_rule != NULL) {
|
|
is->is_rule->fr_ref++;
|
|
pass = is->is_rule->fr_flags;
|
|
} else
|
|
pass = fr_flags;
|
|
MUTEX_DOWNGRADE(&ipf_mutex);
|
|
WRITE_ENTER(&ipf_state);
|
|
|
|
is->is_rout = pass & FR_OUTQUE ? 1 : 0;
|
|
is->is_pass = pass;
|
|
is->is_pkts = 1;
|
|
is->is_bytes = ip->ip_len;
|
|
/*
|
|
* We want to check everything that is a property of this packet,
|
|
* but we don't (automatically) care about it's fragment status as
|
|
* this may change.
|
|
*/
|
|
is->is_opt = fin->fin_fi.fi_optmsk;
|
|
is->is_optmsk = 0xffffffff;
|
|
is->is_sec = fin->fin_fi.fi_secmsk;
|
|
is->is_secmsk = 0xffff;
|
|
is->is_auth = fin->fin_fi.fi_auth;
|
|
is->is_authmsk = 0xffff;
|
|
is->is_flags = fin->fin_fi.fi_fl & FI_CMP;
|
|
is->is_flags |= FI_CMP << 4;
|
|
is->is_flags |= flags & (FI_W_DPORT|FI_W_SPORT);
|
|
/*
|
|
* add into table.
|
|
*/
|
|
is->is_next = ips_table[hv];
|
|
ips_table[hv] = is;
|
|
if (is->is_next == NULL)
|
|
ips_stats.iss_inuse++;
|
|
if (fin->fin_out) {
|
|
is->is_ifpin = NULL;
|
|
is->is_ifpout = fin->fin_ifp;
|
|
} else {
|
|
is->is_ifpin = fin->fin_ifp;
|
|
is->is_ifpout = NULL;
|
|
}
|
|
if (pass & FR_LOGFIRST)
|
|
is->is_pass &= ~(FR_LOGFIRST|FR_LOG);
|
|
ATOMIC_INC(ips_num);
|
|
#ifdef IPFILTER_LOG
|
|
ipstate_log(is, ISL_NEW);
|
|
#endif
|
|
RWLOCK_EXIT(&ipf_state);
|
|
fin->fin_rev = (is->is_dst.s_addr != ip->ip_dst.s_addr);
|
|
if (fin->fin_fi.fi_fl & FI_FRAG)
|
|
ipfr_newfrag(ip, fin, pass ^ FR_KEEPSTATE);
|
|
return is;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* check to see if a packet with TCP headers fits within the TCP window.
|
|
* change timeout depending on whether new packet is a SYN-ACK returning for a
|
|
* SYN or a RST or FIN which indicate time to close up shop.
|
|
*/
|
|
int fr_tcpstate(is, fin, ip, tcp)
|
|
register ipstate_t *is;
|
|
fr_info_t *fin;
|
|
ip_t *ip;
|
|
tcphdr_t *tcp;
|
|
{
|
|
register tcp_seq seq, ack, end;
|
|
register int ackskew;
|
|
tcpdata_t *fdata, *tdata;
|
|
u_short win, maxwin;
|
|
int ret = 0;
|
|
int source;
|
|
|
|
/*
|
|
* Find difference between last checked packet and this packet.
|
|
*/
|
|
source = (ip->ip_src.s_addr == is->is_src.s_addr);
|
|
fdata = &is->is_tcp.ts_data[!source];
|
|
tdata = &is->is_tcp.ts_data[source];
|
|
seq = ntohl(tcp->th_seq);
|
|
ack = ntohl(tcp->th_ack);
|
|
win = ntohs(tcp->th_win);
|
|
end = seq + ip->ip_len - fin->fin_hlen - (tcp->th_off << 2) +
|
|
((tcp->th_flags & TH_SYN) ? 1 : 0) +
|
|
((tcp->th_flags & TH_FIN) ? 1 : 0);
|
|
|
|
if (fdata->td_end == 0) {
|
|
/*
|
|
* Must be a (outgoing) SYN-ACK in reply to a SYN.
|
|
*/
|
|
fdata->td_end = end;
|
|
fdata->td_maxwin = 1;
|
|
fdata->td_maxend = end + 1;
|
|
}
|
|
|
|
if (!(tcp->th_flags & TH_ACK)) { /* Pretend an ack was sent */
|
|
ack = tdata->td_end;
|
|
win = 1;
|
|
} else if (((tcp->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) &&
|
|
(ack == 0)) {
|
|
/* gross hack to get around certain broken tcp stacks */
|
|
ack = tdata->td_end;
|
|
}
|
|
|
|
if (seq == end)
|
|
seq = end = fdata->td_end;
|
|
|
|
maxwin = tdata->td_maxwin;
|
|
ackskew = tdata->td_end - ack;
|
|
|
|
#define SEQ_GE(a,b) ((int)((a) - (b)) >= 0)
|
|
#define SEQ_GT(a,b) ((int)((a) - (b)) > 0)
|
|
if ((SEQ_GE(fdata->td_maxend, end)) &&
|
|
(SEQ_GE(seq + maxwin, fdata->td_end - maxwin)) &&
|
|
/* XXX what about big packets */
|
|
#define MAXACKWINDOW 66000
|
|
(ackskew >= -MAXACKWINDOW) &&
|
|
(ackskew <= MAXACKWINDOW)) {
|
|
/* if ackskew < 0 then this should be due to fragented
|
|
* packets. There is no way to know the length of the
|
|
* total packet in advance.
|
|
* We do know the total length from the fragment cache though.
|
|
* Note however that there might be more sessions with
|
|
* exactly the same source and destination paramters in the
|
|
* state cache (and source and destination is the only stuff
|
|
* that is saved in the fragment cache). Note further that
|
|
* some TCP connections in the state cache are hashed with
|
|
* sport and dport as well which makes it not worthwhile to
|
|
* look for them.
|
|
* Thus, when ackskew is negative but still seems to belong
|
|
* to this session, we bump up the destinations end value.
|
|
*/
|
|
if (ackskew < 0)
|
|
tdata->td_end = ack;
|
|
|
|
/* update max window seen */
|
|
if (fdata->td_maxwin < win)
|
|
fdata->td_maxwin = win;
|
|
if (SEQ_GT(end, fdata->td_end))
|
|
fdata->td_end = end;
|
|
if (SEQ_GE(ack + win, tdata->td_maxend)) {
|
|
tdata->td_maxend = ack + win;
|
|
if (win == 0)
|
|
tdata->td_maxend++;
|
|
}
|
|
|
|
ATOMIC_INC(ips_stats.iss_hits);
|
|
is->is_pkts++;
|
|
is->is_bytes += ip->ip_len;
|
|
/*
|
|
* Nearing end of connection, start timeout.
|
|
*/
|
|
MUTEX_ENTER(&ipf_rw);
|
|
fr_tcp_age(&is->is_age, is->is_state, ip, fin, source);
|
|
MUTEX_EXIT(&ipf_rw);
|
|
ret = 1;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
|
|
static int fr_matchsrcdst(is, src, dst, fin, tcp)
|
|
ipstate_t *is;
|
|
struct in_addr src, dst;
|
|
fr_info_t *fin;
|
|
tcphdr_t *tcp;
|
|
{
|
|
int ret = 0, rev, out, flags;
|
|
u_short sp, dp;
|
|
void *ifp;
|
|
|
|
rev = fin->fin_rev = (is->is_dst.s_addr != dst.s_addr);
|
|
ifp = fin->fin_ifp;
|
|
out = fin->fin_out;
|
|
|
|
if (tcp != NULL) {
|
|
flags = is->is_flags;
|
|
sp = tcp->th_sport;
|
|
dp = tcp->th_dport;
|
|
} else {
|
|
flags = 0;
|
|
sp = 0;
|
|
dp = 0;
|
|
}
|
|
|
|
if (rev == 0) {
|
|
if (!out) {
|
|
if (is->is_ifpin == ifp)
|
|
ret = 1;
|
|
} else {
|
|
if (is->is_ifpout == NULL || is->is_ifpout == ifp)
|
|
ret = 1;
|
|
}
|
|
} else {
|
|
if (out) {
|
|
if (is->is_ifpin == ifp)
|
|
ret = 1;
|
|
} else {
|
|
if (is->is_ifpout == NULL || is->is_ifpout == ifp)
|
|
ret = 1;
|
|
}
|
|
}
|
|
if (ret == 0)
|
|
return 0;
|
|
ret = 0;
|
|
|
|
if (rev == 0) {
|
|
if ((is->is_dst.s_addr == dst.s_addr) &&
|
|
(is->is_src.s_addr == src.s_addr) &&
|
|
(!tcp || ((sp == is->is_sport || flags & FI_W_SPORT) &&
|
|
(dp == is->is_dport || flags & FI_W_DPORT)))) {
|
|
ret = 1;
|
|
}
|
|
} else {
|
|
if ((is->is_dst.s_addr == src.s_addr) &&
|
|
(is->is_src.s_addr == dst.s_addr) &&
|
|
(!tcp || ((sp == is->is_dport || flags & FI_W_DPORT) &&
|
|
(dp == is->is_sport || flags & FI_W_SPORT)))) {
|
|
ret = 1;
|
|
}
|
|
}
|
|
if (ret == 0)
|
|
return 0;
|
|
|
|
/*
|
|
* Whether or not this should be here, is questionable, but the aim
|
|
* is to get this out of the main line.
|
|
*/
|
|
if (tcp == NULL)
|
|
flags = is->is_flags & (FI_CMP|(FI_CMP<<4));
|
|
|
|
if (((fin->fin_fi.fi_fl & (flags >> 4)) != (flags & FI_CMP)) ||
|
|
((fin->fin_fi.fi_optmsk & is->is_optmsk) != is->is_opt) ||
|
|
((fin->fin_fi.fi_secmsk & is->is_secmsk) != is->is_sec) ||
|
|
((fin->fin_fi.fi_auth & is->is_authmsk) != is->is_auth))
|
|
return 0;
|
|
|
|
if ((flags & (FI_W_SPORT|FI_W_DPORT))) {
|
|
if ((flags & FI_W_SPORT) != 0) {
|
|
if (rev == 0) {
|
|
is->is_sport = sp;
|
|
is->is_send = htonl(tcp->th_seq);
|
|
} else {
|
|
is->is_sport = dp;
|
|
is->is_send = htonl(tcp->th_ack);
|
|
}
|
|
is->is_maxsend = is->is_send + 1;
|
|
} else if ((flags & FI_W_DPORT) != 0) {
|
|
if (rev == 0) {
|
|
is->is_dport = dp;
|
|
is->is_dend = htonl(tcp->th_ack);
|
|
} else {
|
|
is->is_dport = sp;
|
|
is->is_dend = htonl(tcp->th_seq);
|
|
}
|
|
is->is_maxdend = is->is_dend + 1;
|
|
}
|
|
is->is_flags &= ~(FI_W_SPORT|FI_W_DPORT);
|
|
}
|
|
|
|
if (!rev) {
|
|
if (out && (out == is->is_rout)) {
|
|
if (!is->is_ifpout)
|
|
is->is_ifpout = ifp;
|
|
} else {
|
|
if (!is->is_ifpin)
|
|
is->is_ifpin = ifp;
|
|
}
|
|
} else {
|
|
if (!out && (out != is->is_rout)) {
|
|
if (!is->is_ifpin)
|
|
is->is_ifpin = ifp;
|
|
} else {
|
|
if (!is->is_ifpout)
|
|
is->is_ifpout = ifp;
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
|
|
frentry_t *fr_checkicmpmatchingstate(ip, fin)
|
|
ip_t *ip;
|
|
fr_info_t *fin;
|
|
{
|
|
register struct in_addr dst, src;
|
|
register ipstate_t *is, **isp;
|
|
register u_short sport, dport;
|
|
register u_char pr;
|
|
struct icmp *ic;
|
|
fr_info_t ofin;
|
|
u_int hv, dest;
|
|
tcphdr_t *tcp;
|
|
frentry_t *fr;
|
|
ip_t *oip;
|
|
int type;
|
|
|
|
/*
|
|
* Does it at least have the return (basic) IP header ?
|
|
* Only a basic IP header (no options) should be with
|
|
* an ICMP error header.
|
|
*/
|
|
if ((ip->ip_hl != 5) || (ip->ip_len < ICMPERR_MINPKTLEN))
|
|
return NULL;
|
|
ic = (struct icmp *)((char *)ip + fin->fin_hlen);
|
|
type = ic->icmp_type;
|
|
/*
|
|
* If it's not an error type, then return
|
|
*/
|
|
if ((type != ICMP_UNREACH) && (type != ICMP_SOURCEQUENCH) &&
|
|
(type != ICMP_REDIRECT) && (type != ICMP_TIMXCEED) &&
|
|
(type != ICMP_PARAMPROB))
|
|
return NULL;
|
|
|
|
oip = (ip_t *)((char *)fin->fin_dp + ICMPERR_ICMPHLEN);
|
|
if (ip->ip_len < ICMPERR_MAXPKTLEN + ((oip->ip_hl - 5) << 2))
|
|
return NULL;
|
|
if ((oip->ip_p != IPPROTO_TCP) && (oip->ip_p != IPPROTO_UDP))
|
|
return NULL;
|
|
|
|
tcp = (tcphdr_t *)((char *)oip + (oip->ip_hl << 2));
|
|
dport = tcp->th_dport;
|
|
sport = tcp->th_sport;
|
|
|
|
hv = (pr = oip->ip_p);
|
|
hv += (src.s_addr = oip->ip_src.s_addr);
|
|
hv += (dst.s_addr = oip->ip_dst.s_addr);
|
|
hv += dport;
|
|
hv += sport;
|
|
hv %= fr_statesize;
|
|
/*
|
|
* we make an fin entry to be able to feed it to
|
|
* matchsrcdst note that not all fields are encessary
|
|
* but this is the cleanest way. Note further we fill
|
|
* in fin_mp such that if someone uses it we'll get
|
|
* a kernel panic. fr_matchsrcdst does not use this.
|
|
*
|
|
* watch out here, as ip is in host order and oip in network
|
|
* order. Any change we make must be undone afterwards.
|
|
*/
|
|
oip->ip_len = ntohs(oip->ip_len);
|
|
fr_makefrip(oip->ip_hl << 2, oip, &ofin);
|
|
oip->ip_len = htons(oip->ip_len);
|
|
ofin.fin_ifp = fin->fin_ifp;
|
|
ofin.fin_out = !fin->fin_out;
|
|
ofin.fin_mp = NULL; /* if dereferenced, panic XXX */
|
|
READ_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_next) {
|
|
/*
|
|
* Only allow this icmp though if the
|
|
* encapsulated packet was allowed through the
|
|
* other way around. Note that the minimal amount
|
|
* of info present does not allow for checking against
|
|
* tcp internals such as seq and ack numbers.
|
|
*/
|
|
if ((is->is_p == pr) &&
|
|
fr_matchsrcdst(is, src, dst, &ofin, tcp)) {
|
|
fr = is->is_rule;
|
|
ips_stats.iss_hits++;
|
|
/*
|
|
* we must swap src and dst here because the icmp
|
|
* comes the other way around
|
|
*/
|
|
dest = (is->is_dst.s_addr != src.s_addr);
|
|
is->is_pkts++;
|
|
is->is_bytes += ip->ip_len;
|
|
/*
|
|
* we deliberately do not touch the timeouts
|
|
* for the accompanying state table entry.
|
|
* It remains to be seen if that is correct. XXX
|
|
*/
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return fr;
|
|
}
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Check if a packet has a registered state.
|
|
*/
|
|
frentry_t *fr_checkstate(ip, fin)
|
|
ip_t *ip;
|
|
fr_info_t *fin;
|
|
{
|
|
register struct in_addr dst, src;
|
|
register ipstate_t *is, **isp;
|
|
register u_char pr;
|
|
u_int hv, hvm, hlen, tryagain, pass;
|
|
struct icmp *ic;
|
|
frentry_t *fr;
|
|
tcphdr_t *tcp;
|
|
|
|
if ((ip->ip_off & IP_OFFMASK) || (fin->fin_fi.fi_fl & FI_SHORT))
|
|
return NULL;
|
|
|
|
is = NULL;
|
|
hlen = fin->fin_hlen;
|
|
tcp = (tcphdr_t *)((char *)ip + hlen);
|
|
ic = (struct icmp *)tcp;
|
|
hv = (pr = ip->ip_p);
|
|
hv += (src.s_addr = ip->ip_src.s_addr);
|
|
hv += (dst.s_addr = ip->ip_dst.s_addr);
|
|
|
|
/*
|
|
* Search the hash table for matching packet header info.
|
|
*/
|
|
switch (ip->ip_p)
|
|
{
|
|
case IPPROTO_ICMP :
|
|
hv += ic->icmp_id;
|
|
hv += ic->icmp_seq;
|
|
hv %= fr_statesize;
|
|
READ_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_next)
|
|
if ((is->is_p == pr) &&
|
|
(ic->icmp_id == is->is_icmp.ics_id) &&
|
|
(ic->icmp_seq == is->is_icmp.ics_seq) &&
|
|
fr_matchsrcdst(is, src, dst, fin, NULL)) {
|
|
if ((is->is_type == ICMP_ECHOREPLY) &&
|
|
(ic->icmp_type == ICMP_ECHO))
|
|
;
|
|
else if (is->is_type != ic->icmp_type)
|
|
continue;
|
|
is->is_age = fr_icmptimeout;
|
|
break;
|
|
}
|
|
if (is != NULL)
|
|
break;
|
|
RWLOCK_EXIT(&ipf_state);
|
|
/*
|
|
* No matching icmp state entry. Perhaps this is a
|
|
* response to another state entry.
|
|
*/
|
|
fr = fr_checkicmpmatchingstate(ip, fin);
|
|
if (fr)
|
|
return fr;
|
|
break;
|
|
case IPPROTO_TCP :
|
|
{
|
|
register u_short dport = tcp->th_dport, sport = tcp->th_sport;
|
|
|
|
tryagain = 0;
|
|
retry_tcp:
|
|
hvm = hv % fr_statesize;
|
|
WRITE_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hvm]; (is = *isp);
|
|
isp = &is->is_next)
|
|
if ((is->is_p == pr) &&
|
|
fr_matchsrcdst(is, src, dst, fin, tcp)) {
|
|
if (fr_tcpstate(is, fin, ip, tcp)) {
|
|
break;
|
|
#ifndef _KERNEL
|
|
if (tcp->th_flags & TCP_CLOSE) {
|
|
*isp = is->is_next;
|
|
isp = &ips_table[hvm];
|
|
if (ips_table[hvm] == NULL)
|
|
ips_stats.iss_inuse--;
|
|
fr_delstate(is);
|
|
ips_num--;
|
|
}
|
|
#endif
|
|
break;
|
|
}
|
|
is = NULL;
|
|
break;
|
|
}
|
|
if (is != NULL)
|
|
break;
|
|
RWLOCK_EXIT(&ipf_state);
|
|
hv += dport;
|
|
hv += sport;
|
|
if (tryagain == 0) {
|
|
tryagain = 1;
|
|
goto retry_tcp;
|
|
}
|
|
break;
|
|
}
|
|
case IPPROTO_UDP :
|
|
{
|
|
register u_short dport = tcp->th_dport, sport = tcp->th_sport;
|
|
|
|
tryagain = 0;
|
|
retry_udp:
|
|
hvm = hv % fr_statesize;
|
|
/*
|
|
* Nothing else to match on but ports. and IP#'s
|
|
*/
|
|
READ_ENTER(&ipf_state);
|
|
for (is = ips_table[hvm]; is; is = is->is_next)
|
|
if ((is->is_p == pr) &&
|
|
fr_matchsrcdst(is, src, dst, fin, tcp)) {
|
|
is->is_age = fr_udptimeout;
|
|
break;
|
|
}
|
|
if (is != NULL)
|
|
break;
|
|
RWLOCK_EXIT(&ipf_state);
|
|
hv += dport;
|
|
hv += sport;
|
|
if (tryagain == 0) {
|
|
tryagain = 1;
|
|
goto retry_udp;
|
|
}
|
|
break;
|
|
}
|
|
default :
|
|
break;
|
|
}
|
|
if (is == NULL) {
|
|
ATOMIC_INC(ips_stats.iss_miss);
|
|
return NULL;
|
|
}
|
|
MUTEX_ENTER(&ipf_rw);
|
|
is->is_bytes += ip->ip_len;
|
|
ips_stats.iss_hits++;
|
|
is->is_pkts++;
|
|
MUTEX_EXIT(&ipf_rw);
|
|
fr = is->is_rule;
|
|
fin->fin_fr = fr;
|
|
pass = is->is_pass;
|
|
RWLOCK_EXIT(&ipf_state);
|
|
if (fin->fin_fi.fi_fl & FI_FRAG)
|
|
ipfr_newfrag(ip, fin, pass ^ FR_KEEPSTATE);
|
|
return fr;
|
|
}
|
|
|
|
|
|
static void fr_delstate(is)
|
|
ipstate_t *is;
|
|
{
|
|
frentry_t *fr;
|
|
|
|
fr = is->is_rule;
|
|
if (fr != NULL) {
|
|
ATOMIC_DEC(fr->fr_ref);
|
|
if (fr->fr_ref == 0)
|
|
KFREE(fr);
|
|
}
|
|
KFREE(is);
|
|
}
|
|
|
|
|
|
/*
|
|
* Free memory in use by all state info. kept.
|
|
*/
|
|
void fr_stateunload()
|
|
{
|
|
register int i;
|
|
register ipstate_t *is, **isp;
|
|
|
|
WRITE_ENTER(&ipf_state);
|
|
for (i = fr_statesize - 1; i >= 0; i--)
|
|
for (isp = &ips_table[i]; (is = *isp); ) {
|
|
*isp = is->is_next;
|
|
fr_delstate(is);
|
|
ips_num--;
|
|
}
|
|
ips_stats.iss_inuse = 0;
|
|
ips_num = 0;
|
|
RWLOCK_EXIT(&ipf_state);
|
|
KFREES(ips_table, fr_statesize * sizeof(ipstate_t *));
|
|
ips_table = NULL;
|
|
}
|
|
|
|
|
|
/*
|
|
* Slowly expire held state for thingslike UDP and ICMP. Timeouts are set
|
|
* in expectation of this being called twice per second.
|
|
*/
|
|
void fr_timeoutstate()
|
|
{
|
|
register int i;
|
|
register ipstate_t *is, **isp;
|
|
#if defined(_KERNEL) && !SOLARIS
|
|
int s;
|
|
#endif
|
|
|
|
SPL_NET(s);
|
|
WRITE_ENTER(&ipf_state);
|
|
for (i = fr_statesize - 1; i >= 0; i--)
|
|
for (isp = &ips_table[i]; (is = *isp); )
|
|
if (is->is_age && !--is->is_age) {
|
|
*isp = is->is_next;
|
|
if (is->is_p == IPPROTO_TCP)
|
|
ips_stats.iss_fin++;
|
|
else
|
|
ips_stats.iss_expire++;
|
|
if (ips_table[i] == NULL)
|
|
ips_stats.iss_inuse--;
|
|
#ifdef IPFILTER_LOG
|
|
ipstate_log(is, ISL_EXPIRE);
|
|
#endif
|
|
fr_delstate(is);
|
|
ips_num--;
|
|
} else
|
|
isp = &is->is_next;
|
|
RWLOCK_EXIT(&ipf_state);
|
|
SPL_X(s);
|
|
}
|
|
|
|
|
|
/*
|
|
* Original idea freom Pradeep Krishnan for use primarily with NAT code.
|
|
* (pkrishna@netcom.com)
|
|
*/
|
|
void fr_tcp_age(age, state, ip, fin, dir)
|
|
u_long *age;
|
|
u_char *state;
|
|
ip_t *ip;
|
|
fr_info_t *fin;
|
|
int dir;
|
|
{
|
|
tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp;
|
|
u_char flags = tcp->th_flags;
|
|
int dlen, ostate;
|
|
|
|
ostate = state[1 - dir];
|
|
|
|
dlen = ip->ip_len - fin->fin_hlen - (tcp->th_off << 2);
|
|
|
|
if (flags & TH_RST) {
|
|
if (!(tcp->th_flags & TH_PUSH) && !dlen) {
|
|
*age = fr_tcpclosed;
|
|
state[dir] = TCPS_CLOSED;
|
|
} else {
|
|
*age = fr_tcpclosewait;
|
|
state[dir] = TCPS_CLOSE_WAIT;
|
|
}
|
|
return;
|
|
}
|
|
|
|
*age = fr_tcptimeout; /* 1 min */
|
|
|
|
switch(state[dir])
|
|
{
|
|
case TCPS_CLOSED:
|
|
if ((flags & (TH_FIN|TH_SYN|TH_RST|TH_ACK)) == TH_ACK) {
|
|
state[dir] = TCPS_ESTABLISHED;
|
|
*age = fr_tcpidletimeout;
|
|
}
|
|
case TCPS_FIN_WAIT_2:
|
|
if ((flags & TH_OPENING) == TH_OPENING)
|
|
state[dir] = TCPS_SYN_RECEIVED;
|
|
else if (flags & TH_SYN)
|
|
state[dir] = TCPS_SYN_SENT;
|
|
break;
|
|
case TCPS_SYN_RECEIVED:
|
|
case TCPS_SYN_SENT:
|
|
if ((flags & (TH_FIN|TH_ACK)) == TH_ACK) {
|
|
state[dir] = TCPS_ESTABLISHED;
|
|
*age = fr_tcpidletimeout;
|
|
} else if ((flags & (TH_FIN|TH_ACK)) == (TH_FIN|TH_ACK)) {
|
|
state[dir] = TCPS_CLOSE_WAIT;
|
|
if (!(flags & TH_PUSH) && !dlen &&
|
|
ostate > TCPS_ESTABLISHED)
|
|
*age = fr_tcplastack;
|
|
else
|
|
*age = fr_tcpclosewait;
|
|
}
|
|
break;
|
|
case TCPS_ESTABLISHED:
|
|
if (flags & TH_FIN) {
|
|
state[dir] = TCPS_CLOSE_WAIT;
|
|
if (!(flags & TH_PUSH) && !dlen &&
|
|
ostate > TCPS_ESTABLISHED)
|
|
*age = fr_tcplastack;
|
|
else
|
|
*age = fr_tcpclosewait;
|
|
} else {
|
|
if (ostate < TCPS_CLOSE_WAIT)
|
|
*age = fr_tcpidletimeout;
|
|
}
|
|
break;
|
|
case TCPS_CLOSE_WAIT:
|
|
if ((flags & TH_FIN) && !(flags & TH_PUSH) && !dlen &&
|
|
ostate > TCPS_ESTABLISHED) {
|
|
*age = fr_tcplastack;
|
|
state[dir] = TCPS_LAST_ACK;
|
|
} else
|
|
*age = fr_tcpclosewait;
|
|
break;
|
|
case TCPS_LAST_ACK:
|
|
if (flags & TH_ACK) {
|
|
state[dir] = TCPS_FIN_WAIT_2;
|
|
if (!(flags & TH_PUSH) && !dlen &&
|
|
ostate > TCPS_ESTABLISHED)
|
|
*age = fr_tcplastack;
|
|
else {
|
|
*age = fr_tcpclosewait;
|
|
state[dir] = TCPS_CLOSE_WAIT;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
#ifdef IPFILTER_LOG
|
|
void ipstate_log(is, type)
|
|
struct ipstate *is;
|
|
u_int type;
|
|
{
|
|
struct ipslog ipsl;
|
|
void *items[1];
|
|
size_t sizes[1];
|
|
int types[1];
|
|
|
|
ipsl.isl_type = type;
|
|
ipsl.isl_pkts = is->is_pkts;
|
|
ipsl.isl_bytes = is->is_bytes;
|
|
ipsl.isl_src = is->is_src;
|
|
ipsl.isl_dst = is->is_dst;
|
|
ipsl.isl_p = is->is_p;
|
|
ipsl.isl_flags = is->is_flags;
|
|
if (ipsl.isl_p == IPPROTO_TCP || ipsl.isl_p == IPPROTO_UDP) {
|
|
ipsl.isl_sport = is->is_sport;
|
|
ipsl.isl_dport = is->is_dport;
|
|
if (ipsl.isl_p == IPPROTO_TCP) {
|
|
ipsl.isl_state[0] = is->is_state[0];
|
|
ipsl.isl_state[1] = is->is_state[1];
|
|
}
|
|
} else if (ipsl.isl_p == IPPROTO_ICMP)
|
|
ipsl.isl_itype = is->is_icmp.ics_type;
|
|
else {
|
|
ipsl.isl_ps.isl_filler[0] = 0;
|
|
ipsl.isl_ps.isl_filler[1] = 0;
|
|
}
|
|
items[0] = &ipsl;
|
|
sizes[0] = sizeof(ipsl);
|
|
types[0] = 0;
|
|
|
|
(void) ipllog(IPL_LOGSTATE, NULL, items, sizes, types, 1);
|
|
}
|
|
#endif
|