3803 lines
109 KiB
C
3803 lines
109 KiB
C
/* $NetBSD$ */
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/*
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* Copyright (C) 1995-2003 by Darren Reed.
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*
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* See the IPFILTER.LICENCE file for details on licencing.
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*/
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#if defined(KERNEL) || defined(_KERNEL)
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# undef KERNEL
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# undef _KERNEL
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# define KERNEL 1
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# define _KERNEL 1
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#endif
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#include <sys/errno.h>
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/file.h>
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#if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \
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defined(_KERNEL)
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# include "opt_ipfilter_log.h"
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#endif
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#if defined(_KERNEL) && defined(__FreeBSD_version) && \
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(__FreeBSD_version >= 400000) && !defined(KLD_MODULE)
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#include "opt_inet6.h"
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#endif
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#if !defined(_KERNEL) && !defined(__KERNEL__)
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# include <stdio.h>
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# include <stdlib.h>
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# include <string.h>
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# define _KERNEL
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# ifdef __OpenBSD__
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struct file;
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# endif
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# include <sys/uio.h>
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# undef _KERNEL
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#endif
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#if defined(_KERNEL) && (__FreeBSD_version >= 220000)
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# include <sys/filio.h>
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# include <sys/fcntl.h>
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# if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM)
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# include "opt_ipfilter.h"
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# endif
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#else
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# include <sys/ioctl.h>
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#endif
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#include <sys/time.h>
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#if !defined(linux)
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# include <sys/protosw.h>
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#endif
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#include <sys/socket.h>
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#if defined(_KERNEL)
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# include <sys/systm.h>
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# if !defined(__SVR4) && !defined(__svr4__)
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# include <sys/mbuf.h>
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# endif
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#endif
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#if defined(__SVR4) || defined(__svr4__)
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# include <sys/filio.h>
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# include <sys/byteorder.h>
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# ifdef _KERNEL
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# include <sys/dditypes.h>
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# endif
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# include <sys/stream.h>
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# include <sys/kmem.h>
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#endif
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#include <net/if.h>
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#ifdef sun
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# include <net/af.h>
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#endif
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/tcp.h>
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#if !defined(linux)
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# include <netinet/ip_var.h>
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#endif
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#if !defined(__hpux) && !defined(linux)
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# include <netinet/tcp_fsm.h>
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#endif
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#include <netinet/udp.h>
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#include <netinet/ip_icmp.h>
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#include "netinet/ip_compat.h"
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#include <netinet/tcpip.h>
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#include "netinet/ip_fil.h"
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#include "netinet/ip_nat.h"
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#include "netinet/ip_frag.h"
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#include "netinet/ip_state.h"
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#include "netinet/ip_proxy.h"
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#ifdef IPFILTER_SYNC
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#include "netinet/ip_sync.h"
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#endif
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#ifdef IPFILTER_SCAN
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#include "netinet/ip_scan.h"
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#endif
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#ifdef USE_INET6
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#include <netinet/icmp6.h>
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#endif
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#if (__FreeBSD_version >= 300000)
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# include <sys/malloc.h>
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# if defined(_KERNEL) && !defined(IPFILTER_LKM)
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# include <sys/libkern.h>
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# include <sys/systm.h>
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# endif
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#endif
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/* END OF INCLUDES */
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#if !defined(lint)
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static const char sccsid[] = "@(#)ip_state.c 1.8 6/5/96 (C) 1993-2000 Darren Reed";
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static const char rcsid[] = "@(#)Id: ip_state.c,v 2.186.2.29 2005/03/28 10:47:54 darrenr Exp";
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#endif
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static ipstate_t **ips_table = NULL;
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static u_long *ips_seed = NULL;
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static int ips_num = 0;
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static u_long ips_last_force_flush = 0;
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ips_stat_t ips_stats;
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#ifdef USE_INET6
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static ipstate_t *fr_checkicmp6matchingstate __P((fr_info_t *));
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#endif
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static ipstate_t *fr_matchsrcdst __P((fr_info_t *, ipstate_t *, i6addr_t *,
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i6addr_t *, tcphdr_t *, u_32_t));
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static ipstate_t *fr_checkicmpmatchingstate __P((fr_info_t *));
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static int fr_state_flush __P((int, int));
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static ips_stat_t *fr_statetstats __P((void));
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static void fr_delstate __P((ipstate_t *, int));
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static int fr_state_remove __P((caddr_t));
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static void fr_ipsmove __P((ipstate_t *, u_int));
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static int fr_tcpstate __P((fr_info_t *, tcphdr_t *, ipstate_t *));
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static int fr_tcpoptions __P((fr_info_t *, tcphdr_t *, tcpdata_t *));
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static ipstate_t *fr_stclone __P((fr_info_t *, tcphdr_t *, ipstate_t *));
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static void fr_fixinisn __P((fr_info_t *, ipstate_t *));
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static void fr_fixoutisn __P((fr_info_t *, ipstate_t *));
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static void fr_checknewisn __P((fr_info_t *, ipstate_t *));
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int fr_stputent __P((caddr_t));
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int fr_stgetent __P((caddr_t));
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#define ONE_DAY IPF_TTLVAL(1 * 86400) /* 1 day */
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#define FIVE_DAYS (5 * ONE_DAY)
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#define DOUBLE_HASH(x) (((x) + ips_seed[(x) % fr_statesize]) % fr_statesize)
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u_long fr_tcpidletimeout = FIVE_DAYS,
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fr_tcpclosewait = IPF_TTLVAL(2 * TCP_MSL),
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fr_tcplastack = IPF_TTLVAL(2 * TCP_MSL),
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fr_tcptimeout = IPF_TTLVAL(2 * TCP_MSL),
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fr_tcpclosed = IPF_TTLVAL(60),
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fr_tcphalfclosed = IPF_TTLVAL(2 * 3600), /* 2 hours */
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fr_udptimeout = IPF_TTLVAL(120),
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fr_udpacktimeout = IPF_TTLVAL(12),
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fr_icmptimeout = IPF_TTLVAL(60),
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fr_icmpacktimeout = IPF_TTLVAL(6),
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fr_iptimeout = IPF_TTLVAL(60);
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int fr_statemax = IPSTATE_MAX,
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fr_statesize = IPSTATE_SIZE;
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int fr_state_doflush = 0,
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fr_state_lock = 0,
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fr_state_maxbucket = 0,
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fr_state_maxbucket_reset = 1,
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fr_state_init = 0;
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ipftq_t ips_tqtqb[IPF_TCP_NSTATES],
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ips_udptq,
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ips_udpacktq,
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ips_iptq,
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ips_icmptq,
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ips_icmpacktq,
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*ips_utqe = NULL;
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#ifdef IPFILTER_LOG
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int ipstate_logging = 1;
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#else
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int ipstate_logging = 0;
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#endif
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ipstate_t *ips_list = NULL;
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/* ------------------------------------------------------------------------ */
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/* Function: fr_stateinit */
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/* Returns: int - 0 == success, -1 == failure */
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/* Parameters: Nil */
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/* */
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/* Initialise all the global variables used within the state code. */
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/* This action also includes initiailising locks. */
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/* ------------------------------------------------------------------------ */
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int fr_stateinit()
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{
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int i;
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KMALLOCS(ips_table, ipstate_t **, fr_statesize * sizeof(ipstate_t *));
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if (ips_table == NULL)
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return -1;
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bzero((char *)ips_table, fr_statesize * sizeof(ipstate_t *));
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KMALLOCS(ips_seed, u_long *, fr_statesize * sizeof(*ips_seed));
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if (ips_seed == NULL)
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return -2;
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for (i = 0; i < fr_statesize; i++) {
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/*
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* XXX - ips_seed[X] should be a random number of sorts.
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*/
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#if (__FreeBSD_version >= 400000)
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ips_seed[i] = arc4random();
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#else
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ips_seed[i] = ((u_long)ips_seed + i) * fr_statesize;
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ips_seed[i] ^= 0xa5a55a5a;
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ips_seed[i] *= (u_long)ips_seed;
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ips_seed[i] ^= 0x5a5aa5a5;
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ips_seed[i] *= fr_statemax;
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#endif
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}
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/* fill icmp reply type table */
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for (i = 0; i <= ICMP_MAXTYPE; i++)
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icmpreplytype4[i] = -1;
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icmpreplytype4[ICMP_ECHO] = ICMP_ECHOREPLY;
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icmpreplytype4[ICMP_TSTAMP] = ICMP_TSTAMPREPLY;
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icmpreplytype4[ICMP_IREQ] = ICMP_IREQREPLY;
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icmpreplytype4[ICMP_MASKREQ] = ICMP_MASKREPLY;
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#ifdef USE_INET6
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/* fill icmp reply type table */
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for (i = 0; i <= ICMP6_MAXTYPE; i++)
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icmpreplytype6[i] = -1;
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icmpreplytype6[ICMP6_ECHO_REQUEST] = ICMP6_ECHO_REPLY;
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icmpreplytype6[ICMP6_MEMBERSHIP_QUERY] = ICMP6_MEMBERSHIP_REPORT;
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icmpreplytype6[ICMP6_NI_QUERY] = ICMP6_NI_REPLY;
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icmpreplytype6[ND_ROUTER_SOLICIT] = ND_ROUTER_ADVERT;
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icmpreplytype6[ND_NEIGHBOR_SOLICIT] = ND_NEIGHBOR_ADVERT;
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#endif
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KMALLOCS(ips_stats.iss_bucketlen, u_long *,
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fr_statesize * sizeof(u_long));
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if (ips_stats.iss_bucketlen == NULL)
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return -1;
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bzero((char *)ips_stats.iss_bucketlen, fr_statesize * sizeof(u_long));
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if (fr_state_maxbucket == 0) {
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for (i = fr_statesize; i > 0; i >>= 1)
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fr_state_maxbucket++;
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fr_state_maxbucket *= 2;
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}
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fr_sttab_init(ips_tqtqb);
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ips_tqtqb[IPF_TCP_NSTATES - 1].ifq_next = &ips_udptq;
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ips_udptq.ifq_ttl = (u_long)fr_udptimeout;
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ips_udptq.ifq_ref = 1;
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ips_udptq.ifq_head = NULL;
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ips_udptq.ifq_tail = &ips_udptq.ifq_head;
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MUTEX_INIT(&ips_udptq.ifq_lock, "ipftq udp tab");
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ips_udptq.ifq_next = &ips_udpacktq;
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ips_udpacktq.ifq_ttl = (u_long)fr_udpacktimeout;
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ips_udpacktq.ifq_ref = 1;
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ips_udpacktq.ifq_head = NULL;
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ips_udpacktq.ifq_tail = &ips_udpacktq.ifq_head;
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MUTEX_INIT(&ips_udpacktq.ifq_lock, "ipftq udpack tab");
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ips_udpacktq.ifq_next = &ips_icmptq;
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ips_icmptq.ifq_ttl = (u_long)fr_icmptimeout;
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ips_icmptq.ifq_ref = 1;
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ips_icmptq.ifq_head = NULL;
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ips_icmptq.ifq_tail = &ips_icmptq.ifq_head;
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MUTEX_INIT(&ips_icmptq.ifq_lock, "ipftq icmp tab");
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ips_icmptq.ifq_next = &ips_icmpacktq;
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ips_icmpacktq.ifq_ttl = (u_long)fr_icmpacktimeout;
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ips_icmpacktq.ifq_ref = 1;
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ips_icmpacktq.ifq_head = NULL;
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ips_icmpacktq.ifq_tail = &ips_icmpacktq.ifq_head;
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MUTEX_INIT(&ips_icmpacktq.ifq_lock, "ipftq icmpack tab");
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ips_icmpacktq.ifq_next = &ips_iptq;
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ips_iptq.ifq_ttl = (u_long)fr_iptimeout;
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ips_iptq.ifq_ref = 1;
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ips_iptq.ifq_head = NULL;
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ips_iptq.ifq_tail = &ips_iptq.ifq_head;
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MUTEX_INIT(&ips_iptq.ifq_lock, "ipftq ip tab");
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ips_iptq.ifq_next = NULL;
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RWLOCK_INIT(&ipf_state, "ipf IP state rwlock");
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MUTEX_INIT(&ipf_stinsert, "ipf state insert mutex");
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fr_state_init = 1;
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ips_last_force_flush = fr_ticks;
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return 0;
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}
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/* ------------------------------------------------------------------------ */
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/* Function: fr_stateunload */
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/* Returns: Nil */
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/* Parameters: Nil */
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/* */
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/* Release and destroy any resources acquired or initialised so that */
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/* IPFilter can be unloaded or re-initialised. */
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/* ------------------------------------------------------------------------ */
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void fr_stateunload()
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{
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ipftq_t *ifq, *ifqnext;
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ipstate_t *is;
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while ((is = ips_list) != NULL)
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fr_delstate(is, 0);
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/*
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* Proxy timeout queues are not cleaned here because although they
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* exist on the state list, appr_unload is called after fr_stateunload
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* and the proxies actually are responsible for them being created.
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* Should the proxy timeouts have their own list? There's no real
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* justification as this is the only complicationA
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*/
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for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) {
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ifqnext = ifq->ifq_next;
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if (((ifq->ifq_flags & IFQF_PROXY) == 0) &&
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(fr_deletetimeoutqueue(ifq) == 0))
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fr_freetimeoutqueue(ifq);
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}
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ips_stats.iss_inuse = 0;
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ips_num = 0;
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if (fr_state_init == 1) {
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fr_sttab_destroy(ips_tqtqb);
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MUTEX_DESTROY(&ips_udptq.ifq_lock);
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MUTEX_DESTROY(&ips_icmptq.ifq_lock);
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MUTEX_DESTROY(&ips_udpacktq.ifq_lock);
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MUTEX_DESTROY(&ips_icmpacktq.ifq_lock);
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MUTEX_DESTROY(&ips_iptq.ifq_lock);
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}
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if (ips_table != NULL) {
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KFREES(ips_table, fr_statesize * sizeof(*ips_table));
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ips_table = NULL;
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}
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if (ips_seed != NULL) {
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KFREES(ips_seed, fr_statesize * sizeof(*ips_seed));
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ips_seed = NULL;
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}
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if (ips_stats.iss_bucketlen != NULL) {
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KFREES(ips_stats.iss_bucketlen, fr_statesize * sizeof(u_long));
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ips_stats.iss_bucketlen = NULL;
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}
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if (fr_state_maxbucket_reset == 1)
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fr_state_maxbucket = 0;
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if (fr_state_init == 1) {
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fr_state_init = 0;
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RW_DESTROY(&ipf_state);
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MUTEX_DESTROY(&ipf_stinsert);
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}
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}
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/* ------------------------------------------------------------------------ */
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/* Function: fr_statetstats */
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/* Returns: ips_state_t* - pointer to state stats structure */
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/* Parameters: Nil */
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/* */
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/* Put all the current numbers and pointers into a single struct and return */
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/* a pointer to it. */
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/* ------------------------------------------------------------------------ */
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static ips_stat_t *fr_statetstats()
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{
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ips_stats.iss_active = ips_num;
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ips_stats.iss_statesize = fr_statesize;
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ips_stats.iss_statemax = fr_statemax;
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ips_stats.iss_table = ips_table;
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ips_stats.iss_list = ips_list;
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ips_stats.iss_ticks = fr_ticks;
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return &ips_stats;
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}
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/* ------------------------------------------------------------------------ */
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/* Function: fr_state_remove */
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/* Returns: int - 0 == success, != 0 == failure */
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/* Parameters: data(I) - pointer to state structure to delete from table */
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/* */
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/* Search for a state structure that matches the one passed, according to */
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/* the IP addresses and other protocol specific information. */
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/* ------------------------------------------------------------------------ */
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static int fr_state_remove(data)
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caddr_t data;
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{
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ipstate_t *sp, st;
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int error;
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sp = &st;
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error = fr_inobj(data, &st, IPFOBJ_IPSTATE);
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if (error)
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return EFAULT;
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WRITE_ENTER(&ipf_state);
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for (sp = ips_list; sp; sp = sp->is_next)
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if ((sp->is_p == st.is_p) && (sp->is_v == st.is_v) &&
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!bcmp((caddr_t)&sp->is_src, (caddr_t)&st.is_src,
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sizeof(st.is_src)) &&
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!bcmp((caddr_t)&sp->is_dst, (caddr_t)&st.is_src,
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sizeof(st.is_dst)) &&
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!bcmp((caddr_t)&sp->is_ps, (caddr_t)&st.is_ps,
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sizeof(st.is_ps))) {
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fr_delstate(sp, ISL_REMOVE);
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RWLOCK_EXIT(&ipf_state);
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return 0;
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}
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RWLOCK_EXIT(&ipf_state);
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return ESRCH;
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}
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/* ------------------------------------------------------------------------ */
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/* Function: fr_state_ioctl */
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/* Returns: int - 0 == success, != 0 == failure */
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/* Parameters: data(I) - pointer to ioctl data */
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/* cmd(I) - ioctl command integer */
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/* mode(I) - file mode bits used with open */
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/* */
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/* Processes an ioctl call made to operate on the IP Filter state device. */
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/* ------------------------------------------------------------------------ */
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int fr_state_ioctl(data, cmd, mode)
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caddr_t data;
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ioctlcmd_t cmd;
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int mode;
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{
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int arg, ret, error = 0;
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switch (cmd)
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{
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/*
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* Delete an entry from the state table.
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*/
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case SIOCDELST :
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error = fr_state_remove(data);
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break;
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/*
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* Flush the state table
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*/
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case SIOCIPFFL :
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BCOPYIN(data, (char *)&arg, sizeof(arg));
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if (arg == 0 || arg == 1) {
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WRITE_ENTER(&ipf_state);
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ret = fr_state_flush(arg, 4);
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RWLOCK_EXIT(&ipf_state);
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BCOPYOUT((char *)&ret, data, sizeof(ret));
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} else
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error = EINVAL;
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break;
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#ifdef USE_INET6
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case SIOCIPFL6 :
|
|
BCOPYIN(data, (char *)&arg, sizeof(arg));
|
|
if (arg == 0 || arg == 1) {
|
|
WRITE_ENTER(&ipf_state);
|
|
ret = fr_state_flush(arg, 6);
|
|
RWLOCK_EXIT(&ipf_state);
|
|
BCOPYOUT((char *)&ret, data, sizeof(ret));
|
|
} else
|
|
error = EINVAL;
|
|
break;
|
|
#endif
|
|
#ifdef IPFILTER_LOG
|
|
/*
|
|
* Flush the state log.
|
|
*/
|
|
case SIOCIPFFB :
|
|
if (!(mode & FWRITE))
|
|
error = EPERM;
|
|
else {
|
|
int tmp;
|
|
|
|
tmp = ipflog_clear(IPL_LOGSTATE);
|
|
BCOPYOUT((char *)&tmp, data, sizeof(tmp));
|
|
}
|
|
break;
|
|
/*
|
|
* Turn logging of state information on/off.
|
|
*/
|
|
case SIOCSETLG :
|
|
if (!(mode & FWRITE))
|
|
error = EPERM;
|
|
else {
|
|
BCOPYIN((char *)data, (char *)&ipstate_logging,
|
|
sizeof(ipstate_logging));
|
|
}
|
|
break;
|
|
/*
|
|
* Return the current state of logging.
|
|
*/
|
|
case SIOCGETLG :
|
|
BCOPYOUT((char *)&ipstate_logging, (char *)data,
|
|
sizeof(ipstate_logging));
|
|
break;
|
|
/*
|
|
* Return the number of bytes currently waiting to be read.
|
|
*/
|
|
case FIONREAD :
|
|
arg = iplused[IPL_LOGSTATE]; /* returned in an int */
|
|
BCOPYOUT((char *)&arg, data, sizeof(arg));
|
|
break;
|
|
#endif
|
|
/*
|
|
* Get the current state statistics.
|
|
*/
|
|
case SIOCGETFS :
|
|
error = fr_outobj(data, fr_statetstats(), IPFOBJ_STATESTAT);
|
|
break;
|
|
/*
|
|
* Lock/Unlock the state table. (Locking prevents any changes, which
|
|
* means no packets match).
|
|
*/
|
|
case SIOCSTLCK :
|
|
fr_lock(data, &fr_state_lock);
|
|
break;
|
|
/*
|
|
* Add an entry to the current state table.
|
|
*/
|
|
case SIOCSTPUT :
|
|
if (!fr_state_lock) {
|
|
error = EACCES;
|
|
break;
|
|
}
|
|
error = fr_stputent(data);
|
|
break;
|
|
/*
|
|
* Get a state table entry.
|
|
*/
|
|
case SIOCSTGET :
|
|
if (!fr_state_lock) {
|
|
error = EACCES;
|
|
break;
|
|
}
|
|
error = fr_stgetent(data);
|
|
break;
|
|
default :
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
return error;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_stgetent */
|
|
/* Returns: int - 0 == success, != 0 == failure */
|
|
/* Parameters: data(I) - pointer to state structure to retrieve from table */
|
|
/* */
|
|
/* Copy out state information from the kernel to a user space process. If */
|
|
/* there is a filter rule associated with the state entry, copy that out */
|
|
/* as well. The entry to copy out is taken from the value of "ips_next" in */
|
|
/* the struct passed in and if not null and not found in the list of current*/
|
|
/* state entries, the retrieval fails. */
|
|
/* ------------------------------------------------------------------------ */
|
|
int fr_stgetent(data)
|
|
caddr_t data;
|
|
{
|
|
ipstate_t *is, *isn;
|
|
ipstate_save_t ips;
|
|
int error;
|
|
|
|
error = fr_inobj(data, &ips, IPFOBJ_STATESAVE);
|
|
if (error)
|
|
return EFAULT;
|
|
|
|
isn = ips.ips_next;
|
|
if (isn == NULL) {
|
|
isn = ips_list;
|
|
if (isn == NULL) {
|
|
if (ips.ips_next == NULL)
|
|
return ENOENT;
|
|
return 0;
|
|
}
|
|
} else {
|
|
/*
|
|
* Make sure the pointer we're copying from exists in the
|
|
* current list of entries. Security precaution to prevent
|
|
* copying of random kernel data.
|
|
*/
|
|
for (is = ips_list; is; is = is->is_next)
|
|
if (is == isn)
|
|
break;
|
|
if (!is)
|
|
return ESRCH;
|
|
}
|
|
ips.ips_next = isn->is_next;
|
|
bcopy((char *)isn, (char *)&ips.ips_is, sizeof(ips.ips_is));
|
|
ips.ips_rule = isn->is_rule;
|
|
if (isn->is_rule != NULL)
|
|
bcopy((char *)isn->is_rule, (char *)&ips.ips_fr,
|
|
sizeof(ips.ips_fr));
|
|
error = fr_outobj(data, &ips, IPFOBJ_STATESAVE);
|
|
if (error)
|
|
return EFAULT;
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_stputent */
|
|
/* Returns: int - 0 == success, != 0 == failure */
|
|
/* Parameters: data(I) - pointer to state information struct */
|
|
/* */
|
|
/* This function implements the SIOCSTPUT ioctl: insert a state entry into */
|
|
/* the state table. If the state info. includes a pointer to a filter rule */
|
|
/* then also add in an orphaned rule (will not show up in any "ipfstat -io" */
|
|
/* output. */
|
|
/* ------------------------------------------------------------------------ */
|
|
int fr_stputent(data)
|
|
caddr_t data;
|
|
{
|
|
ipstate_t *is, *isn;
|
|
ipstate_save_t ips;
|
|
int error, out, i;
|
|
frentry_t *fr;
|
|
char *name;
|
|
|
|
error = fr_inobj(data, &ips, IPFOBJ_STATESAVE);
|
|
if (error)
|
|
return EFAULT;
|
|
|
|
KMALLOC(isn, ipstate_t *);
|
|
if (isn == NULL)
|
|
return ENOMEM;
|
|
|
|
bcopy((char *)&ips.ips_is, (char *)isn, sizeof(*isn));
|
|
bzero((char *)isn, offsetof(struct ipstate, is_pkts));
|
|
isn->is_sti.tqe_pnext = NULL;
|
|
isn->is_sti.tqe_next = NULL;
|
|
isn->is_sti.tqe_ifq = NULL;
|
|
isn->is_sti.tqe_parent = isn;
|
|
isn->is_ifp[0] = NULL;
|
|
isn->is_ifp[1] = NULL;
|
|
isn->is_ifp[2] = NULL;
|
|
isn->is_ifp[3] = NULL;
|
|
isn->is_sync = NULL;
|
|
fr = ips.ips_rule;
|
|
|
|
if (fr == NULL) {
|
|
READ_ENTER(&ipf_state);
|
|
fr_stinsert(isn, 0);
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return 0;
|
|
}
|
|
|
|
if (isn->is_flags & SI_NEWFR) {
|
|
KMALLOC(fr, frentry_t *);
|
|
if (fr == NULL) {
|
|
KFREE(isn);
|
|
return ENOMEM;
|
|
}
|
|
bcopy((char *)&ips.ips_fr, (char *)fr, sizeof(*fr));
|
|
out = fr->fr_flags & FR_OUTQUE ? 1 : 0;
|
|
isn->is_rule = fr;
|
|
ips.ips_is.is_rule = fr;
|
|
MUTEX_NUKE(&fr->fr_lock);
|
|
MUTEX_INIT(&fr->fr_lock, "state filter rule lock");
|
|
|
|
/*
|
|
* Look up all the interface names in the rule.
|
|
*/
|
|
for (i = 0; i < 4; i++) {
|
|
name = fr->fr_ifnames[i];
|
|
fr->fr_ifas[i] = fr_resolvenic(name, fr->fr_v);
|
|
name = isn->is_ifname[i];
|
|
isn->is_ifp[i] = fr_resolvenic(name, isn->is_v);
|
|
}
|
|
|
|
fr->fr_ref = 0;
|
|
fr->fr_dsize = 0;
|
|
fr->fr_data = NULL;
|
|
|
|
fr_resolvedest(&fr->fr_tif, fr->fr_v);
|
|
fr_resolvedest(&fr->fr_dif, fr->fr_v);
|
|
|
|
/*
|
|
* send a copy back to userland of what we ended up
|
|
* to allow for verification.
|
|
*/
|
|
error = fr_outobj(data, &ips, IPFOBJ_STATESAVE);
|
|
if (error) {
|
|
KFREE(isn);
|
|
MUTEX_DESTROY(&fr->fr_lock);
|
|
KFREE(fr);
|
|
return EFAULT;
|
|
}
|
|
READ_ENTER(&ipf_state);
|
|
fr_stinsert(isn, 0);
|
|
RWLOCK_EXIT(&ipf_state);
|
|
|
|
} else {
|
|
READ_ENTER(&ipf_state);
|
|
for (is = ips_list; is; is = is->is_next)
|
|
if (is->is_rule == fr) {
|
|
fr_stinsert(isn, 0);
|
|
break;
|
|
}
|
|
|
|
if (is == NULL) {
|
|
KFREE(isn);
|
|
isn = NULL;
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
|
|
return (isn == NULL) ? ESRCH : 0;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_stinsert */
|
|
/* Returns: Nil */
|
|
/* Parameters: is(I) - pointer to state structure */
|
|
/* rev(I) - flag indicating forward/reverse direction of packet */
|
|
/* */
|
|
/* Inserts a state structure into the hash table (for lookups) and the list */
|
|
/* of state entries (for enumeration). Resolves all of the interface names */
|
|
/* to pointers and adjusts running stats for the hash table as appropriate. */
|
|
/* */
|
|
/* Locking: it is assumed that some kind of lock on ipf_state is held. */
|
|
/* ------------------------------------------------------------------------ */
|
|
void fr_stinsert(is, rev)
|
|
ipstate_t *is;
|
|
int rev;
|
|
{
|
|
frentry_t *fr;
|
|
u_int hv;
|
|
int i;
|
|
|
|
MUTEX_INIT(&is->is_lock, "ipf state entry");
|
|
|
|
fr = is->is_rule;
|
|
if (fr != NULL) {
|
|
MUTEX_ENTER(&fr->fr_lock);
|
|
fr->fr_ref++;
|
|
fr->fr_statecnt++;
|
|
MUTEX_EXIT(&fr->fr_lock);
|
|
}
|
|
|
|
/*
|
|
* Look up all the interface names in the state entry.
|
|
*/
|
|
for (i = 0; i < 4; i++) {
|
|
if (is->is_ifp[i] != NULL)
|
|
continue;
|
|
is->is_ifp[i] = fr_resolvenic(is->is_ifname[i], is->is_v);
|
|
}
|
|
|
|
/*
|
|
* If we could trust is_hv, then the modulous would not be needed, but
|
|
* when running with IPFILTER_SYNC, this stops bad values.
|
|
*/
|
|
hv = is->is_hv % fr_statesize;
|
|
is->is_hv = hv;
|
|
|
|
/*
|
|
* We need to get both of these locks...the first because it is
|
|
* possible that once the insert is complete another packet might
|
|
* come along, match the entry and want to update it.
|
|
*/
|
|
MUTEX_ENTER(&is->is_lock);
|
|
MUTEX_ENTER(&ipf_stinsert);
|
|
|
|
/*
|
|
* add into list table.
|
|
*/
|
|
if (ips_list != NULL)
|
|
ips_list->is_pnext = &is->is_next;
|
|
is->is_pnext = &ips_list;
|
|
is->is_next = ips_list;
|
|
ips_list = is;
|
|
|
|
if (ips_table[hv] != NULL)
|
|
ips_table[hv]->is_phnext = &is->is_hnext;
|
|
else
|
|
ips_stats.iss_inuse++;
|
|
is->is_phnext = ips_table + hv;
|
|
is->is_hnext = ips_table[hv];
|
|
ips_table[hv] = is;
|
|
ips_stats.iss_bucketlen[hv]++;
|
|
ips_num++;
|
|
MUTEX_EXIT(&ipf_stinsert);
|
|
|
|
fr_setstatequeue(is, rev);
|
|
MUTEX_EXIT(&is->is_lock);
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_addstate */
|
|
/* Returns: ipstate_t* - NULL == failure, else pointer to new state */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* stsave(O) - pointer to place to save pointer to created */
|
|
/* state structure. */
|
|
/* flags(I) - flags to use when creating the structure */
|
|
/* */
|
|
/* Creates a new IP state structure from the packet information collected. */
|
|
/* Inserts it into the state table and appends to the bottom of the active */
|
|
/* list. If the capacity of the table has reached the maximum allowed then */
|
|
/* the call will fail and a flush is scheduled for the next timeout call. */
|
|
/* ------------------------------------------------------------------------ */
|
|
ipstate_t *fr_addstate(fin, stsave, flags)
|
|
fr_info_t *fin;
|
|
ipstate_t **stsave;
|
|
u_int flags;
|
|
{
|
|
ipstate_t *is, ips;
|
|
struct icmp *ic;
|
|
u_int pass, hv;
|
|
frentry_t *fr;
|
|
tcphdr_t *tcp;
|
|
grehdr_t *gre;
|
|
void *ifp;
|
|
int out;
|
|
|
|
if (fr_state_lock ||
|
|
(fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD)))
|
|
return NULL;
|
|
|
|
if ((fin->fin_flx & FI_OOW) && !(fin->fin_tcpf & TH_SYN))
|
|
return NULL;
|
|
|
|
fr = fin->fin_fr;
|
|
if ((fr->fr_statemax == 0) && (ips_num == fr_statemax)) {
|
|
ATOMIC_INCL(ips_stats.iss_max);
|
|
fr_state_doflush = 1;
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* If a "keep state" rule has reached the maximum number of references
|
|
* to it, then schedule an automatic flush in case we can clear out
|
|
* some "dead old wood".
|
|
*/
|
|
if ((fr != NULL) && (fr->fr_statemax != 0) &&
|
|
(fr->fr_statecnt >= fr->fr_statemax)) {
|
|
MUTEX_EXIT(&fr->fr_lock);
|
|
ATOMIC_INCL(ips_stats.iss_maxref);
|
|
fr_state_doflush = 1;
|
|
return NULL;
|
|
}
|
|
|
|
pass = (fr == NULL) ? 0 : fr->fr_flags;
|
|
|
|
ic = NULL;
|
|
tcp = NULL;
|
|
out = fin->fin_out;
|
|
is = &ips;
|
|
bzero((char *)is, sizeof(*is));
|
|
is->is_die = 1 + fr_ticks;
|
|
|
|
/*
|
|
* Copy and calculate...
|
|
*/
|
|
hv = (is->is_p = fin->fin_fi.fi_p);
|
|
is->is_src = fin->fin_fi.fi_src;
|
|
hv += is->is_saddr;
|
|
is->is_dst = fin->fin_fi.fi_dst;
|
|
hv += is->is_daddr;
|
|
#ifdef USE_INET6
|
|
if (fin->fin_v == 6) {
|
|
/*
|
|
* For ICMPv6, we check to see if the destination address is
|
|
* a multicast address. If it is, do not include it in the
|
|
* calculation of the hash because the correct reply will come
|
|
* back from a real address, not a multicast address.
|
|
*/
|
|
if ((is->is_p == IPPROTO_ICMPV6) &&
|
|
IN6_IS_ADDR_MULTICAST(&is->is_dst.in6)) {
|
|
/*
|
|
* So you can do keep state with neighbour discovery.
|
|
*
|
|
* Here we could use the address from the neighbour
|
|
* solicit message to put in the state structure and
|
|
* we could use that without a wildcard flag too...
|
|
*/
|
|
flags |= SI_W_DADDR;
|
|
hv -= is->is_daddr;
|
|
} else {
|
|
hv += is->is_dst.i6[1];
|
|
hv += is->is_dst.i6[2];
|
|
hv += is->is_dst.i6[3];
|
|
}
|
|
hv += is->is_src.i6[1];
|
|
hv += is->is_src.i6[2];
|
|
hv += is->is_src.i6[3];
|
|
}
|
|
#endif
|
|
|
|
switch (is->is_p)
|
|
{
|
|
#ifdef USE_INET6
|
|
case IPPROTO_ICMPV6 :
|
|
ic = fin->fin_dp;
|
|
|
|
switch (ic->icmp_type)
|
|
{
|
|
case ICMP6_ECHO_REQUEST :
|
|
is->is_icmp.ici_type = ic->icmp_type;
|
|
hv += (is->is_icmp.ici_id = ic->icmp_id);
|
|
break;
|
|
case ICMP6_MEMBERSHIP_QUERY :
|
|
case ND_ROUTER_SOLICIT :
|
|
case ND_NEIGHBOR_SOLICIT :
|
|
case ICMP6_NI_QUERY :
|
|
is->is_icmp.ici_type = ic->icmp_type;
|
|
break;
|
|
default :
|
|
return NULL;
|
|
}
|
|
ATOMIC_INCL(ips_stats.iss_icmp);
|
|
break;
|
|
#endif
|
|
case IPPROTO_ICMP :
|
|
ic = fin->fin_dp;
|
|
|
|
switch (ic->icmp_type)
|
|
{
|
|
case ICMP_ECHO :
|
|
case ICMP_TSTAMP :
|
|
case ICMP_IREQ :
|
|
case ICMP_MASKREQ :
|
|
is->is_icmp.ici_type = ic->icmp_type;
|
|
hv += (is->is_icmp.ici_id = ic->icmp_id);
|
|
break;
|
|
default :
|
|
return NULL;
|
|
}
|
|
ATOMIC_INCL(ips_stats.iss_icmp);
|
|
break;
|
|
|
|
case IPPROTO_GRE :
|
|
gre = fin->fin_dp;
|
|
|
|
is->is_gre.gs_flags = gre->gr_flags;
|
|
is->is_gre.gs_ptype = gre->gr_ptype;
|
|
if (GRE_REV(is->is_gre.gs_flags) == 1) {
|
|
is->is_call[0] = fin->fin_data[0];
|
|
is->is_call[1] = fin->fin_data[1];
|
|
}
|
|
break;
|
|
|
|
case IPPROTO_TCP :
|
|
tcp = fin->fin_dp;
|
|
|
|
if (tcp->th_flags & TH_RST)
|
|
return NULL;
|
|
/*
|
|
* The endian of the ports doesn't matter, but the ack and
|
|
* sequence numbers do as we do mathematics on them later.
|
|
*/
|
|
is->is_sport = htons(fin->fin_data[0]);
|
|
is->is_dport = htons(fin->fin_data[1]);
|
|
if ((flags & (SI_W_DPORT|SI_W_SPORT)) == 0) {
|
|
hv += is->is_sport;
|
|
hv += is->is_dport;
|
|
}
|
|
|
|
/*
|
|
* If this is a real packet then initialise fields in the
|
|
* state information structure from the TCP header information.
|
|
*/
|
|
|
|
is->is_maxdwin = 1;
|
|
is->is_maxswin = ntohs(tcp->th_win);
|
|
if (is->is_maxswin == 0)
|
|
is->is_maxswin = 1;
|
|
|
|
if ((fin->fin_flx & FI_IGNORE) == 0) {
|
|
is->is_send = ntohl(tcp->th_seq) + fin->fin_dlen -
|
|
(TCP_OFF(tcp) << 2) +
|
|
((tcp->th_flags & TH_SYN) ? 1 : 0) +
|
|
((tcp->th_flags & TH_FIN) ? 1 : 0);
|
|
is->is_maxsend = is->is_send;
|
|
|
|
/*
|
|
* Window scale option is only present in
|
|
* SYN/SYN-ACK packet.
|
|
*/
|
|
if ((tcp->th_flags & ~(TH_FIN|TH_ACK|TH_ECNALL)) ==
|
|
TH_SYN &&
|
|
(TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2))) {
|
|
if (fr_tcpoptions(fin, tcp,
|
|
&is->is_tcp.ts_data[0]))
|
|
is->is_swinflags = TCP_WSCALE_SEEN|
|
|
TCP_WSCALE_FIRST;
|
|
}
|
|
|
|
if ((fin->fin_out != 0) && (pass & FR_NEWISN) != 0) {
|
|
fr_checknewisn(fin, is);
|
|
fr_fixoutisn(fin, is);
|
|
}
|
|
|
|
if ((tcp->th_flags & TH_OPENING) == TH_SYN)
|
|
flags |= IS_TCPFSM;
|
|
else {
|
|
is->is_maxdwin = is->is_maxswin * 2;
|
|
is->is_dend = ntohl(tcp->th_ack);
|
|
is->is_maxdend = ntohl(tcp->th_ack);
|
|
is->is_maxdwin *= 2;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
ATOMIC_INCL(ips_stats.iss_tcp);
|
|
break;
|
|
|
|
case IPPROTO_UDP :
|
|
tcp = fin->fin_dp;
|
|
|
|
is->is_sport = htons(fin->fin_data[0]);
|
|
is->is_dport = htons(fin->fin_data[1]);
|
|
if ((flags & (SI_W_DPORT|SI_W_SPORT)) == 0) {
|
|
hv += tcp->th_dport;
|
|
hv += tcp->th_sport;
|
|
}
|
|
ATOMIC_INCL(ips_stats.iss_udp);
|
|
break;
|
|
|
|
default :
|
|
break;
|
|
}
|
|
hv = DOUBLE_HASH(hv);
|
|
is->is_hv = hv;
|
|
is->is_rule = fr;
|
|
is->is_flags = flags & IS_INHERITED;
|
|
|
|
/*
|
|
* Look for identical state.
|
|
*/
|
|
for (is = ips_table[is->is_hv % fr_statesize]; is != NULL;
|
|
is = is->is_hnext) {
|
|
if (bcmp(&ips.is_src, &is->is_src,
|
|
offsetof(struct ipstate, is_ps) -
|
|
offsetof(struct ipstate, is_src)) == 0)
|
|
break;
|
|
}
|
|
if (is != NULL)
|
|
return NULL;
|
|
|
|
if (ips_stats.iss_bucketlen[hv] >= fr_state_maxbucket) {
|
|
ATOMIC_INCL(ips_stats.iss_bucketfull);
|
|
return NULL;
|
|
}
|
|
KMALLOC(is, ipstate_t *);
|
|
if (is == NULL) {
|
|
ATOMIC_INCL(ips_stats.iss_nomem);
|
|
return NULL;
|
|
}
|
|
bcopy((char *)&ips, (char *)is, sizeof(*is));
|
|
/*
|
|
* Do not do the modulous here, it is done in fr_stinsert().
|
|
*/
|
|
if (fr != NULL) {
|
|
(void) strncpy(is->is_group, fr->fr_group, FR_GROUPLEN);
|
|
if (fr->fr_age[0] != 0) {
|
|
is->is_tqehead[0] = fr_addtimeoutqueue(&ips_utqe,
|
|
fr->fr_age[0]);
|
|
is->is_sti.tqe_flags |= TQE_RULEBASED;
|
|
}
|
|
if (fr->fr_age[1] != 0) {
|
|
is->is_tqehead[1] = fr_addtimeoutqueue(&ips_utqe,
|
|
fr->fr_age[1]);
|
|
is->is_sti.tqe_flags |= TQE_RULEBASED;
|
|
}
|
|
|
|
is->is_tag = fr->fr_logtag;
|
|
|
|
is->is_ifp[(out << 1) + 1] = fr->fr_ifas[1];
|
|
is->is_ifp[(1 - out) << 1] = fr->fr_ifas[2];
|
|
is->is_ifp[((1 - out) << 1) + 1] = fr->fr_ifas[3];
|
|
|
|
if (((ifp = fr->fr_ifas[1]) != NULL) &&
|
|
(ifp != (void *)-1)) {
|
|
COPYIFNAME(ifp, is->is_ifname[(out << 1) + 1]);
|
|
}
|
|
if (((ifp = fr->fr_ifas[2]) != NULL) &&
|
|
(ifp != (void *)-1)) {
|
|
COPYIFNAME(ifp, is->is_ifname[(1 - out) << 1]);
|
|
}
|
|
if (((ifp = fr->fr_ifas[3]) != NULL) &&
|
|
(ifp != (void *)-1)) {
|
|
COPYIFNAME(ifp, is->is_ifname[((1 - out) << 1) + 1]);
|
|
}
|
|
} else {
|
|
pass = fr_flags;
|
|
is->is_tag = FR_NOLOGTAG;
|
|
}
|
|
|
|
is->is_ifp[out << 1] = fin->fin_ifp;
|
|
if (fin->fin_ifp != NULL) {
|
|
COPYIFNAME(fin->fin_ifp, is->is_ifname[out << 1]);
|
|
}
|
|
|
|
/*
|
|
* It may seem strange to set is_ref to 2, but fr_check() will call
|
|
* fr_statederef() after calling fr_addstate() and the idea is to
|
|
* have it exist at the end of fr_check() with is_ref == 1.
|
|
*/
|
|
is->is_ref = 2;
|
|
is->is_pass = pass;
|
|
is->is_pkts[0] = 0, is->is_bytes[0] = 0;
|
|
is->is_pkts[1] = 0, is->is_bytes[1] = 0;
|
|
is->is_pkts[2] = 0, is->is_bytes[2] = 0;
|
|
is->is_pkts[3] = 0, is->is_bytes[3] = 0;
|
|
if ((fin->fin_flx & FI_IGNORE) == 0) {
|
|
is->is_pkts[out] = 1;
|
|
is->is_bytes[out] = fin->fin_plen;
|
|
is->is_flx[out][0] = fin->fin_flx & FI_CMP;
|
|
is->is_flx[out][0] &= ~FI_OOW;
|
|
}
|
|
|
|
if (pass & FR_STSTRICT)
|
|
is->is_flags |= IS_STRICT;
|
|
|
|
if (pass & FR_STATESYNC)
|
|
is->is_flags |= IS_STATESYNC;
|
|
|
|
/*
|
|
* 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_v = fin->fin_v;
|
|
is->is_opt = fin->fin_optmsk;
|
|
is->is_optmsk = 0xffffffff;
|
|
is->is_sec = fin->fin_secmsk;
|
|
is->is_secmsk = 0xffff;
|
|
is->is_auth = fin->fin_auth;
|
|
is->is_authmsk = 0xffff;
|
|
if (flags & (SI_WILDP|SI_WILDA)) {
|
|
ATOMIC_INCL(ips_stats.iss_wild);
|
|
}
|
|
is->is_rulen = fin->fin_rule;
|
|
|
|
|
|
if (pass & FR_LOGFIRST)
|
|
is->is_pass &= ~(FR_LOGFIRST|FR_LOG);
|
|
|
|
READ_ENTER(&ipf_state);
|
|
is->is_me = stsave;
|
|
|
|
fr_stinsert(is, fin->fin_rev);
|
|
|
|
if (fin->fin_p == IPPROTO_TCP) {
|
|
/*
|
|
* 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(&is->is_lock);
|
|
(void) fr_tcp_age(&is->is_sti, fin, ips_tqtqb, is->is_flags);
|
|
MUTEX_EXIT(&is->is_lock);
|
|
#ifdef IPFILTER_SCAN
|
|
if ((is->is_flags & SI_CLONE) == 0)
|
|
(void) ipsc_attachis(is);
|
|
#endif
|
|
}
|
|
#ifdef IPFILTER_SYNC
|
|
if ((is->is_flags & IS_STATESYNC) && ((is->is_flags & SI_CLONE) == 0))
|
|
is->is_sync = ipfsync_new(SMC_STATE, fin, is);
|
|
#endif
|
|
if (ipstate_logging)
|
|
ipstate_log(is, ISL_NEW);
|
|
|
|
RWLOCK_EXIT(&ipf_state);
|
|
fin->fin_state = is;
|
|
fin->fin_rev = IP6_NEQ(&is->is_dst, &fin->fin_daddr);
|
|
fin->fin_flx |= FI_STATE;
|
|
if (fin->fin_flx & FI_FRAG)
|
|
(void) fr_newfrag(fin, pass ^ FR_KEEPSTATE);
|
|
|
|
return is;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_tcpoptions */
|
|
/* Returns: int - 1 == packet matches state entry, 0 == it does not */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* tcp(I) - pointer to TCP packet header */
|
|
/* td(I) - pointer to TCP data held as part of the state */
|
|
/* */
|
|
/* Look after the TCP header for any options and deal with those that are */
|
|
/* present. Record details about those that we recogise. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static int fr_tcpoptions(fin, tcp, td)
|
|
fr_info_t *fin;
|
|
tcphdr_t *tcp;
|
|
tcpdata_t *td;
|
|
{
|
|
int off, mlen, ol, i, len, retval;
|
|
char buf[64], *s, opt;
|
|
mb_t *m = NULL;
|
|
|
|
off = fin->fin_hlen + sizeof(*tcp);
|
|
len = (TCP_OFF(tcp) << 2) - sizeof(*tcp);
|
|
if (fin->fin_plen < off + len)
|
|
return 0;
|
|
|
|
m = fin->fin_m;
|
|
off += fin->fin_ipoff;
|
|
mlen = MSGDSIZE(m) - off;
|
|
if (len > mlen) {
|
|
len = mlen;
|
|
retval = 0;
|
|
} else {
|
|
retval = 1;
|
|
}
|
|
|
|
COPYDATA(m, off, len, buf);
|
|
|
|
for (s = buf; len > 0; ) {
|
|
opt = *s;
|
|
if (opt == TCPOPT_EOL)
|
|
break;
|
|
else if (opt == TCPOPT_NOP)
|
|
ol = 1;
|
|
else {
|
|
if (len < 2)
|
|
break;
|
|
ol = (int)*(s + 1);
|
|
if (ol < 2 || ol > len)
|
|
break;
|
|
|
|
/*
|
|
* Extract the TCP options we are interested in out of
|
|
* the header and store them in the the tcpdata struct.
|
|
*/
|
|
switch (opt)
|
|
{
|
|
case TCPOPT_WINDOW :
|
|
if (ol == TCPOLEN_WINDOW) {
|
|
i = (int)*(s + 2);
|
|
if (i > TCP_WSCALE_MAX)
|
|
i = TCP_WSCALE_MAX;
|
|
else if (i < 0)
|
|
i = 0;
|
|
td->td_winscale = i;
|
|
}
|
|
break;
|
|
case TCPOPT_MAXSEG :
|
|
/*
|
|
* So, if we wanted to set the TCP MAXSEG,
|
|
* it should be done here...
|
|
*/
|
|
if (ol == TCPOLEN_MAXSEG) {
|
|
i = (int)*(s + 2);
|
|
i <<= 8;
|
|
i += (int)*(s + 3);
|
|
td->td_maxseg = i;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
len -= ol;
|
|
s += ol;
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_tcpstate */
|
|
/* Returns: int - 1 == packet matches state entry, 0 == it does not */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* tcp(I) - pointer to TCP packet header */
|
|
/* is(I) - pointer to master state structure */
|
|
/* */
|
|
/* 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. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static int fr_tcpstate(fin, tcp, is)
|
|
fr_info_t *fin;
|
|
tcphdr_t *tcp;
|
|
ipstate_t *is;
|
|
{
|
|
int source, ret = 0, flags;
|
|
tcpdata_t *fdata, *tdata;
|
|
|
|
source = !fin->fin_rev;
|
|
if (((is->is_flags & IS_TCPFSM) != 0) && (source == 1) &&
|
|
(ntohs(is->is_sport) != fin->fin_data[0]))
|
|
source = 0;
|
|
fdata = &is->is_tcp.ts_data[!source];
|
|
tdata = &is->is_tcp.ts_data[source];
|
|
|
|
MUTEX_ENTER(&is->is_lock);
|
|
if (fr_tcpinwindow(fin, fdata, tdata, tcp, is->is_flags)) {
|
|
#ifdef IPFILTER_SCAN
|
|
if (is->is_flags & (IS_SC_CLIENT|IS_SC_SERVER)) {
|
|
ipsc_packet(fin, is);
|
|
if (FR_ISBLOCK(is->is_pass)) {
|
|
MUTEX_EXIT(&is->is_lock);
|
|
return 1;
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Nearing end of connection, start timeout.
|
|
*/
|
|
ret = fr_tcp_age(&is->is_sti, fin, ips_tqtqb, is->is_flags);
|
|
if (ret == 0) {
|
|
MUTEX_EXIT(&is->is_lock);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* set s0's as appropriate. Use syn-ack packet as it
|
|
* contains both pieces of required information.
|
|
*/
|
|
/*
|
|
* Window scale option is only present in SYN/SYN-ACK packet.
|
|
* Compare with ~TH_FIN to mask out T/TCP setups.
|
|
*/
|
|
flags = tcp->th_flags & ~(TH_FIN|TH_ECNALL);
|
|
if (flags == (TH_SYN|TH_ACK)) {
|
|
is->is_s0[source] = ntohl(tcp->th_ack);
|
|
is->is_s0[!source] = ntohl(tcp->th_seq) + 1;
|
|
if ((TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2)) &&
|
|
tdata->td_winscale) {
|
|
if (fr_tcpoptions(fin, tcp, fdata)) {
|
|
fdata->td_winflags = TCP_WSCALE_SEEN|
|
|
TCP_WSCALE_FIRST;
|
|
} else {
|
|
if (!fdata->td_winscale)
|
|
tdata->td_winscale = 0;
|
|
}
|
|
}
|
|
if ((fin->fin_out != 0) && (is->is_pass & FR_NEWISN))
|
|
fr_checknewisn(fin, is);
|
|
} else if (flags == TH_SYN) {
|
|
is->is_s0[source] = ntohl(tcp->th_seq) + 1;
|
|
if ((TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2)))
|
|
if (fr_tcpoptions(fin, tcp, tdata)) {
|
|
tdata->td_winflags = TCP_WSCALE_SEEN|
|
|
TCP_WSCALE_FIRST;
|
|
}
|
|
|
|
if ((fin->fin_out != 0) && (is->is_pass & FR_NEWISN))
|
|
fr_checknewisn(fin, is);
|
|
|
|
}
|
|
ret = 1;
|
|
} else
|
|
fin->fin_flx |= FI_OOW;
|
|
MUTEX_EXIT(&is->is_lock);
|
|
return ret;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_checknewisn */
|
|
/* Returns: Nil */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* is(I) - pointer to master state structure */
|
|
/* */
|
|
/* Check to see if this TCP connection is expecting and needs a new */
|
|
/* sequence number for a particular direction of the connection. */
|
|
/* */
|
|
/* NOTE: This does not actually change the sequence numbers, only gets new */
|
|
/* one ready. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static void fr_checknewisn(fin, is)
|
|
fr_info_t *fin;
|
|
ipstate_t *is;
|
|
{
|
|
u_32_t sumd, old, new;
|
|
tcphdr_t *tcp;
|
|
int i;
|
|
|
|
i = fin->fin_rev;
|
|
tcp = fin->fin_dp;
|
|
|
|
if (((i == 0) && !(is->is_flags & IS_ISNSYN)) ||
|
|
((i == 1) && !(is->is_flags & IS_ISNACK))) {
|
|
old = ntohl(tcp->th_seq);
|
|
new = fr_newisn(fin);
|
|
is->is_isninc[i] = new - old;
|
|
CALC_SUMD(old, new, sumd);
|
|
is->is_sumd[i] = (sumd & 0xffff) + (sumd >> 16);
|
|
|
|
is->is_flags |= ((i == 0) ? IS_ISNSYN : IS_ISNACK);
|
|
}
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_tcpinwindow */
|
|
/* Returns: int - 1 == packet inside TCP "window", 0 == not inside. */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* fdata(I) - pointer to tcp state informatio (forward) */
|
|
/* tdata(I) - pointer to tcp state informatio (reverse) */
|
|
/* tcp(I) - pointer to TCP packet header */
|
|
/* */
|
|
/* Given a packet has matched addresses and ports, check to see if it is */
|
|
/* within the TCP data window. In a show of generosity, allow packets that */
|
|
/* are within the window space behind the current sequence # as well. */
|
|
/* ------------------------------------------------------------------------ */
|
|
int fr_tcpinwindow(fin, fdata, tdata, tcp, flags)
|
|
fr_info_t *fin;
|
|
tcpdata_t *fdata, *tdata;
|
|
tcphdr_t *tcp;
|
|
int flags;
|
|
{
|
|
tcp_seq seq, ack, end;
|
|
int ackskew, tcpflags;
|
|
u_32_t win, maxwin;
|
|
|
|
/*
|
|
* Find difference between last checked packet and this packet.
|
|
*/
|
|
tcpflags = tcp->th_flags;
|
|
seq = ntohl(tcp->th_seq);
|
|
ack = ntohl(tcp->th_ack);
|
|
if (tcpflags & TH_SYN)
|
|
win = ntohs(tcp->th_win);
|
|
else
|
|
win = ntohs(tcp->th_win) << fdata->td_winscale;
|
|
if (win == 0)
|
|
win = 1;
|
|
|
|
/*
|
|
* if window scaling is present, the scaling is only allowed
|
|
* for windows not in the first SYN packet. In that packet the
|
|
* window is 65535 to specify the largest window possible
|
|
* for receivers not implementing the window scale option.
|
|
* Currently, we do not assume TTCP here. That means that
|
|
* if we see a second packet from a host (after the initial
|
|
* SYN), we can assume that the receiver of the SYN did
|
|
* already send back the SYN/ACK (and thus that we know if
|
|
* the receiver also does window scaling)
|
|
*/
|
|
if (!(tcpflags & TH_SYN) && (fdata->td_winflags & TCP_WSCALE_FIRST)) {
|
|
if (tdata->td_winflags & TCP_WSCALE_SEEN) {
|
|
fdata->td_winflags &= ~TCP_WSCALE_FIRST;
|
|
fdata->td_maxwin = win;
|
|
} else {
|
|
fdata->td_winscale = 0;
|
|
fdata->td_winflags = 0;
|
|
tdata->td_winscale = 0;
|
|
tdata->td_winflags = 0;
|
|
}
|
|
}
|
|
|
|
end = seq + fin->fin_dlen - (TCP_OFF(tcp) << 2) +
|
|
((tcpflags & TH_SYN) ? 1 : 0) + ((tcpflags & TH_FIN) ? 1 : 0);
|
|
|
|
if ((fdata->td_end == 0) &&
|
|
(!(flags & IS_TCPFSM) ||
|
|
((tcpflags & TH_OPENING) == TH_OPENING))) {
|
|
/*
|
|
* Must be a (outgoing) SYN-ACK in reply to a SYN.
|
|
*/
|
|
fdata->td_end = end;
|
|
fdata->td_maxwin = 1;
|
|
fdata->td_maxend = end + win;
|
|
}
|
|
|
|
if (!(tcpflags & TH_ACK)) { /* Pretend an ack was sent */
|
|
ack = tdata->td_end;
|
|
} else if (((tcpflags & (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;
|
|
|
|
/*
|
|
* Strict sequencing only allows in-order delivery.
|
|
*/
|
|
if ((flags & IS_STRICT) != 0) {
|
|
if (seq != fdata->td_end) {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
#define SEQ_GE(a,b) ((int)((a) - (b)) >= 0)
|
|
#define SEQ_GT(a,b) ((int)((a) - (b)) > 0)
|
|
if (
|
|
#if defined(_KERNEL)
|
|
(SEQ_GE(fdata->td_maxend, end)) &&
|
|
(SEQ_GE(seq, fdata->td_end - maxwin)) &&
|
|
#endif
|
|
/* XXX what about big packets */
|
|
#define MAXACKWINDOW 66000
|
|
(-ackskew <= (MAXACKWINDOW << fdata->td_winscale)) &&
|
|
( ackskew <= (MAXACKWINDOW << fdata->td_winscale))) {
|
|
|
|
/* if ackskew < 0 then this should be due to fragmented
|
|
* 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 parameters 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;
|
|
return 1;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_stclone */
|
|
/* Returns: ipstate_t* - NULL == cloning failed, */
|
|
/* else pointer to new state structure */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* tcp(I) - pointer to TCP/UDP header */
|
|
/* is(I) - pointer to master state structure */
|
|
/* */
|
|
/* Create a "duplcate" state table entry from the master. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static ipstate_t *fr_stclone(fin, tcp, is)
|
|
fr_info_t *fin;
|
|
tcphdr_t *tcp;
|
|
ipstate_t *is;
|
|
{
|
|
ipstate_t *clone;
|
|
u_32_t send;
|
|
|
|
if (ips_num == fr_statemax) {
|
|
ATOMIC_INCL(ips_stats.iss_max);
|
|
fr_state_doflush = 1;
|
|
return NULL;
|
|
}
|
|
KMALLOC(clone, ipstate_t *);
|
|
if (clone == NULL)
|
|
return NULL;
|
|
bcopy((char *)is, (char *)clone, sizeof(*clone));
|
|
|
|
MUTEX_NUKE(&clone->is_lock);
|
|
|
|
clone->is_die = ONE_DAY + fr_ticks;
|
|
clone->is_state[0] = 0;
|
|
clone->is_state[1] = 0;
|
|
send = ntohl(tcp->th_seq) + fin->fin_dlen - (TCP_OFF(tcp) << 2) +
|
|
((tcp->th_flags & TH_SYN) ? 1 : 0) +
|
|
((tcp->th_flags & TH_FIN) ? 1 : 0);
|
|
|
|
if (fin->fin_rev == 1) {
|
|
clone->is_dend = send;
|
|
clone->is_maxdend = send;
|
|
clone->is_send = 0;
|
|
clone->is_maxswin = 1;
|
|
clone->is_maxdwin = ntohs(tcp->th_win);
|
|
if (clone->is_maxdwin == 0)
|
|
clone->is_maxdwin = 1;
|
|
} else {
|
|
clone->is_send = send;
|
|
clone->is_maxsend = send;
|
|
clone->is_dend = 0;
|
|
clone->is_maxdwin = 1;
|
|
clone->is_maxswin = ntohs(tcp->th_win);
|
|
if (clone->is_maxswin == 0)
|
|
clone->is_maxswin = 1;
|
|
}
|
|
|
|
clone->is_flags &= ~SI_CLONE;
|
|
clone->is_flags |= SI_CLONED;
|
|
fr_stinsert(clone, fin->fin_rev);
|
|
MUTEX_ENTER(&clone->is_lock);
|
|
clone->is_ref = 1;
|
|
if (clone->is_p == IPPROTO_TCP) {
|
|
(void) fr_tcp_age(&clone->is_sti, fin, ips_tqtqb,
|
|
clone->is_flags);
|
|
}
|
|
MUTEX_EXIT(&clone->is_lock);
|
|
#ifdef IPFILTER_SCAN
|
|
(void) ipsc_attachis(is);
|
|
#endif
|
|
#ifdef IPFILTER_SYNC
|
|
if (is->is_flags & IS_STATESYNC)
|
|
clone->is_sync = ipfsync_new(SMC_STATE, fin, clone);
|
|
#endif
|
|
return clone;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_matchsrcdst */
|
|
/* Returns: Nil */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* is(I) - pointer to state structure */
|
|
/* src(I) - pointer to source address */
|
|
/* dst(I) - pointer to destination address */
|
|
/* tcp(I) - pointer to TCP/UDP header */
|
|
/* */
|
|
/* Match a state table entry against an IP packet. The logic below is that */
|
|
/* ret gets set to one if the match succeeds, else remains 0. If it is */
|
|
/* still 0 after the test. no match. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static ipstate_t *fr_matchsrcdst(fin, is, src, dst, tcp, cmask)
|
|
fr_info_t *fin;
|
|
ipstate_t *is;
|
|
i6addr_t *src, *dst;
|
|
tcphdr_t *tcp;
|
|
u_32_t cmask;
|
|
{
|
|
int ret = 0, rev, out, flags, flx = 0, idx;
|
|
u_short sp, dp;
|
|
u_32_t cflx;
|
|
void *ifp;
|
|
|
|
rev = IP6_NEQ(&is->is_dst, dst);
|
|
ifp = fin->fin_ifp;
|
|
out = fin->fin_out;
|
|
flags = is->is_flags;
|
|
sp = 0;
|
|
dp = 0;
|
|
|
|
if (tcp != NULL) {
|
|
sp = htons(fin->fin_sport);
|
|
dp = ntohs(fin->fin_dport);
|
|
}
|
|
if (!rev) {
|
|
if (tcp != NULL) {
|
|
if (!(flags & SI_W_SPORT) && (sp != is->is_sport))
|
|
rev = 1;
|
|
else if (!(flags & SI_W_DPORT) && (dp != is->is_dport))
|
|
rev = 1;
|
|
}
|
|
}
|
|
|
|
idx = (out << 1) + rev;
|
|
|
|
/*
|
|
* If the interface for this 'direction' is set, make sure it matches.
|
|
* An interface name that is not set matches any, as does a name of *.
|
|
*/
|
|
if ((is->is_ifp[idx] == NULL &&
|
|
(*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '*')) ||
|
|
is->is_ifp[idx] == ifp)
|
|
ret = 1;
|
|
|
|
if (ret == 0)
|
|
return NULL;
|
|
ret = 0;
|
|
|
|
/*
|
|
* Match addresses and ports.
|
|
*/
|
|
if (rev == 0) {
|
|
if ((IP6_EQ(&is->is_dst, dst) || (flags & SI_W_DADDR)) &&
|
|
(IP6_EQ(&is->is_src, src) || (flags & SI_W_SADDR))) {
|
|
if (tcp) {
|
|
if ((sp == is->is_sport || flags & SI_W_SPORT)&&
|
|
(dp == is->is_dport || flags & SI_W_DPORT))
|
|
ret = 1;
|
|
} else {
|
|
ret = 1;
|
|
}
|
|
}
|
|
} else {
|
|
if ((IP6_EQ(&is->is_dst, src) || (flags & SI_W_DADDR)) &&
|
|
(IP6_EQ(&is->is_src, dst) || (flags & SI_W_SADDR))) {
|
|
if (tcp) {
|
|
if ((dp == is->is_sport || flags & SI_W_SPORT)&&
|
|
(sp == is->is_dport || flags & SI_W_DPORT))
|
|
ret = 1;
|
|
} else {
|
|
ret = 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (ret == 0)
|
|
return NULL;
|
|
|
|
/*
|
|
* 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 & ~(SI_WILDP|SI_NEWFR|SI_CLONE|SI_CLONED);
|
|
|
|
/*
|
|
* Only one of the source or destination address can be flaged as a
|
|
* wildcard. Fill in the missing address, if set.
|
|
* For IPv6, if the address being copied in is multicast, then
|
|
* don't reset the wild flag - multicast causes it to be set in the
|
|
* first place!
|
|
*/
|
|
if ((flags & (SI_W_SADDR|SI_W_DADDR))) {
|
|
fr_ip_t *fi = &fin->fin_fi;
|
|
|
|
if ((flags & SI_W_SADDR) != 0) {
|
|
if (rev == 0) {
|
|
#ifdef USE_INET6
|
|
if (is->is_v == 6 &&
|
|
IN6_IS_ADDR_MULTICAST(&fi->fi_src.in6))
|
|
/*EMPTY*/;
|
|
else
|
|
#endif
|
|
{
|
|
is->is_src = fi->fi_src;
|
|
is->is_flags &= ~SI_W_SADDR;
|
|
}
|
|
} else {
|
|
#ifdef USE_INET6
|
|
if (is->is_v == 6 &&
|
|
IN6_IS_ADDR_MULTICAST(&fi->fi_dst.in6))
|
|
/*EMPTY*/;
|
|
else
|
|
#endif
|
|
{
|
|
is->is_src = fi->fi_dst;
|
|
is->is_flags &= ~SI_W_SADDR;
|
|
}
|
|
}
|
|
} else if ((flags & SI_W_DADDR) != 0) {
|
|
if (rev == 0) {
|
|
#ifdef USE_INET6
|
|
if (is->is_v == 6 &&
|
|
IN6_IS_ADDR_MULTICAST(&fi->fi_dst.in6))
|
|
/*EMPTY*/;
|
|
else
|
|
#endif
|
|
{
|
|
is->is_dst = fi->fi_dst;
|
|
is->is_flags &= ~SI_W_DADDR;
|
|
}
|
|
} else {
|
|
#ifdef USE_INET6
|
|
if (is->is_v == 6 &&
|
|
IN6_IS_ADDR_MULTICAST(&fi->fi_src.in6))
|
|
/*EMPTY*/;
|
|
else
|
|
#endif
|
|
{
|
|
is->is_dst = fi->fi_src;
|
|
is->is_flags &= ~SI_W_DADDR;
|
|
}
|
|
}
|
|
}
|
|
if ((is->is_flags & (SI_WILDA|SI_WILDP)) == 0) {
|
|
ATOMIC_DECL(ips_stats.iss_wild);
|
|
}
|
|
}
|
|
|
|
flx = fin->fin_flx & cmask;
|
|
cflx = is->is_flx[out][rev];
|
|
|
|
/*
|
|
* Match up any flags set from IP options.
|
|
*/
|
|
if ((cflx && (flx != (cflx & cmask))) ||
|
|
((fin->fin_optmsk & is->is_optmsk) != is->is_opt) ||
|
|
((fin->fin_secmsk & is->is_secmsk) != is->is_sec) ||
|
|
((fin->fin_auth & is->is_authmsk) != is->is_auth))
|
|
return NULL;
|
|
|
|
/*
|
|
* Only one of the source or destination port can be flagged as a
|
|
* wildcard. When filling it in, fill in a copy of the matched entry
|
|
* if it has the cloning flag set.
|
|
*/
|
|
if ((fin->fin_flx & FI_IGNORE) != 0) {
|
|
fin->fin_rev = rev;
|
|
return is;
|
|
}
|
|
|
|
if ((flags & (SI_W_SPORT|SI_W_DPORT))) {
|
|
if ((flags & SI_CLONE) != 0) {
|
|
is = fr_stclone(fin, tcp, is);
|
|
if (is == NULL)
|
|
return NULL;
|
|
} else {
|
|
ATOMIC_DECL(ips_stats.iss_wild);
|
|
}
|
|
|
|
if ((flags & SI_W_SPORT) != 0) {
|
|
if (rev == 0) {
|
|
is->is_sport = sp;
|
|
is->is_send = ntohl(tcp->th_seq);
|
|
} else {
|
|
is->is_sport = dp;
|
|
is->is_send = ntohl(tcp->th_ack);
|
|
}
|
|
is->is_maxsend = is->is_send + 1;
|
|
} else if ((flags & SI_W_DPORT) != 0) {
|
|
if (rev == 0) {
|
|
is->is_dport = dp;
|
|
is->is_dend = ntohl(tcp->th_ack);
|
|
} else {
|
|
is->is_dport = sp;
|
|
is->is_dend = ntohl(tcp->th_seq);
|
|
}
|
|
is->is_maxdend = is->is_dend + 1;
|
|
}
|
|
is->is_flags &= ~(SI_W_SPORT|SI_W_DPORT);
|
|
if ((flags & SI_CLONED) && ipstate_logging)
|
|
ipstate_log(is, ISL_CLONE);
|
|
}
|
|
|
|
ret = -1;
|
|
|
|
if (is->is_flx[out][rev] == 0)
|
|
is->is_flx[out][rev] = flx;
|
|
|
|
/*
|
|
* Check if the interface name for this "direction" is set and if not,
|
|
* fill it in.
|
|
*/
|
|
if (is->is_ifp[idx] == NULL &&
|
|
(*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '*')) {
|
|
is->is_ifp[idx] = ifp;
|
|
COPYIFNAME(ifp, is->is_ifname[idx]);
|
|
}
|
|
fin->fin_rev = rev;
|
|
return is;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_checkicmpmatchingstate */
|
|
/* Returns: Nil */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* */
|
|
/* If we've got an ICMP error message, using the information stored in the */
|
|
/* ICMP packet, look for a matching state table entry. */
|
|
/* */
|
|
/* If we return NULL then no lock on ipf_state is held. */
|
|
/* If we return non-null then a read-lock on ipf_state is held. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static ipstate_t *fr_checkicmpmatchingstate(fin)
|
|
fr_info_t *fin;
|
|
{
|
|
ipstate_t *is, **isp;
|
|
u_short sport, dport;
|
|
u_char pr;
|
|
int backward, i, oi;
|
|
i6addr_t dst, src;
|
|
struct icmp *ic;
|
|
u_short savelen;
|
|
icmphdr_t *icmp;
|
|
fr_info_t ofin;
|
|
tcphdr_t *tcp;
|
|
int type, len;
|
|
ip_t *oip;
|
|
u_int hv;
|
|
|
|
/*
|
|
* 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 ((fin->fin_v != 4) || (fin->fin_hlen != sizeof(ip_t)) ||
|
|
(fin->fin_plen < ICMPERR_MINPKTLEN))
|
|
return NULL;
|
|
ic = fin->fin_dp;
|
|
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 *)ic + ICMPERR_ICMPHLEN);
|
|
/*
|
|
* Check if the at least the old IP header (with options) and
|
|
* 8 bytes of payload is present.
|
|
*/
|
|
if (fin->fin_plen < ICMPERR_MAXPKTLEN + ((IP_HL(oip) - 5) << 2))
|
|
return NULL;
|
|
|
|
/*
|
|
* Sanity Checks.
|
|
*/
|
|
len = fin->fin_dlen - ICMPERR_ICMPHLEN;
|
|
if ((len <= 0) || ((IP_HL(oip) << 2) > len))
|
|
return NULL;
|
|
|
|
/*
|
|
* Is the buffer big enough for all of it ? It's the size of the IP
|
|
* header claimed in the encapsulated part which is of concern. It
|
|
* may be too big to be in this buffer but not so big that it's
|
|
* outside the ICMP packet, leading to TCP deref's causing problems.
|
|
* This is possible because we don't know how big oip_hl is when we
|
|
* do the pullup early in fr_check() and thus can't guarantee it is
|
|
* all here now.
|
|
*/
|
|
#ifdef _KERNEL
|
|
{
|
|
mb_t *m;
|
|
|
|
m = fin->fin_m;
|
|
# if defined(MENTAT)
|
|
if ((char *)oip + len > (char *)m->b_wptr)
|
|
return NULL;
|
|
# else
|
|
if ((char *)oip + len > (char *)fin->fin_ip + m->m_len)
|
|
return NULL;
|
|
# endif
|
|
}
|
|
#endif
|
|
bcopy((char *)fin, (char *)&ofin, sizeof(fin));
|
|
|
|
/*
|
|
* in the IPv4 case we must zero the i6addr union otherwise
|
|
* the IP6_EQ and IP6_NEQ macros produce the wrong results because
|
|
* of the 'junk' in the unused part of the union
|
|
*/
|
|
bzero((char *)&src, sizeof(src));
|
|
bzero((char *)&dst, sizeof(dst));
|
|
|
|
/*
|
|
* 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, like
|
|
* oip->ip_off - it is still in network byte order so fix it.
|
|
*/
|
|
savelen = oip->ip_len;
|
|
oip->ip_len = len;
|
|
oip->ip_off = htons(oip->ip_off);
|
|
|
|
ofin.fin_flx = FI_NOCKSUM;
|
|
ofin.fin_v = 4;
|
|
ofin.fin_ip = oip;
|
|
ofin.fin_m = NULL; /* if dereferenced, panic XXX */
|
|
ofin.fin_mp = NULL; /* if dereferenced, panic XXX */
|
|
ofin.fin_plen = fin->fin_dlen - ICMPERR_ICMPHLEN;
|
|
(void) fr_makefrip(IP_HL(oip) << 2, oip, &ofin);
|
|
ofin.fin_ifp = fin->fin_ifp;
|
|
ofin.fin_out = !fin->fin_out;
|
|
/*
|
|
* Reset the short and bad flag here because in fr_matchsrcdst()
|
|
* the flags for the current packet (fin_flx) are compared against
|
|
* those for the existing session.
|
|
*/
|
|
ofin.fin_flx &= ~(FI_BAD|FI_SHORT);
|
|
|
|
/*
|
|
* Put old values of ip_len and ip_off back as we don't know
|
|
* if we have to forward the packet (or process it again.
|
|
*/
|
|
oip->ip_len = savelen;
|
|
oip->ip_off = htons(oip->ip_off);
|
|
|
|
switch (oip->ip_p)
|
|
{
|
|
case IPPROTO_ICMP :
|
|
icmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2));
|
|
|
|
/*
|
|
* an ICMP error can only be generated as a result of an
|
|
* ICMP query, not as the response on an ICMP error
|
|
*
|
|
* XXX theoretically ICMP_ECHOREP and the other reply's are
|
|
* ICMP query's as well, but adding them here seems strange XXX
|
|
*/
|
|
if ((icmp->icmp_type != ICMP_ECHO) &&
|
|
(icmp->icmp_type != ICMP_TSTAMP) &&
|
|
(icmp->icmp_type != ICMP_IREQ) &&
|
|
(icmp->icmp_type != ICMP_MASKREQ))
|
|
return NULL;
|
|
|
|
/*
|
|
* perform a lookup of the ICMP packet in the state table
|
|
*/
|
|
hv = (pr = oip->ip_p);
|
|
src.in4 = oip->ip_src;
|
|
hv += src.in4.s_addr;
|
|
dst.in4 = oip->ip_dst;
|
|
hv += dst.in4.s_addr;
|
|
hv += icmp->icmp_id;
|
|
hv = DOUBLE_HASH(hv);
|
|
|
|
READ_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) {
|
|
isp = &is->is_hnext;
|
|
if ((is->is_p != pr) || (is->is_v != 4))
|
|
continue;
|
|
if (is->is_pass & FR_NOICMPERR)
|
|
continue;
|
|
is = fr_matchsrcdst(&ofin, is, &src, &dst,
|
|
NULL, FI_ICMPCMP);
|
|
if (is != NULL) {
|
|
if ((is->is_pass & FR_NOICMPERR) != 0) {
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return NULL;
|
|
}
|
|
/*
|
|
* i : the index of this packet (the icmp
|
|
* unreachable)
|
|
* oi : the index of the original packet found
|
|
* in the icmp header (i.e. the packet
|
|
* causing this icmp)
|
|
* backward : original packet was backward
|
|
* compared to the state
|
|
*/
|
|
backward = IP6_NEQ(&is->is_src, &src);
|
|
fin->fin_rev = !backward;
|
|
i = (!backward << 1) + fin->fin_out;
|
|
oi = (backward << 1) + ofin.fin_out;
|
|
if (is->is_icmppkts[i] > is->is_pkts[oi])
|
|
continue;
|
|
ips_stats.iss_hits++;
|
|
is->is_icmppkts[i]++;
|
|
return is;
|
|
}
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return NULL;
|
|
case IPPROTO_TCP :
|
|
case IPPROTO_UDP :
|
|
break;
|
|
default :
|
|
return NULL;
|
|
}
|
|
|
|
tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2));
|
|
dport = tcp->th_dport;
|
|
sport = tcp->th_sport;
|
|
|
|
hv = (pr = oip->ip_p);
|
|
src.in4 = oip->ip_src;
|
|
hv += src.in4.s_addr;
|
|
dst.in4 = oip->ip_dst;
|
|
hv += dst.in4.s_addr;
|
|
hv += dport;
|
|
hv += sport;
|
|
hv = DOUBLE_HASH(hv);
|
|
|
|
READ_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) {
|
|
isp = &is->is_hnext;
|
|
/*
|
|
* 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. Only the
|
|
* ports are known to be present and can be even if the
|
|
* short flag is set.
|
|
*/
|
|
if ((is->is_p == pr) && (is->is_v == 4) &&
|
|
(is = fr_matchsrcdst(&ofin, is, &src, &dst,
|
|
tcp, FI_ICMPCMP))) {
|
|
/*
|
|
* i : the index of this packet (the icmp unreachable)
|
|
* oi : the index of the original packet found in the
|
|
* icmp header (i.e. the packet causing this icmp)
|
|
* backward : original packet was backward compared to
|
|
* the state
|
|
*/
|
|
backward = IP6_NEQ(&is->is_src, &src);
|
|
fin->fin_rev = !backward;
|
|
i = (!backward << 1) + fin->fin_out;
|
|
oi = (backward << 1) + ofin.fin_out;
|
|
|
|
if (((is->is_pass & FR_NOICMPERR) != 0) ||
|
|
(is->is_icmppkts[i] > is->is_pkts[oi]))
|
|
break;
|
|
ips_stats.iss_hits++;
|
|
is->is_icmppkts[i]++;
|
|
/*
|
|
* we deliberately do not touch the timeouts
|
|
* for the accompanying state table entry.
|
|
* It remains to be seen if that is correct. XXX
|
|
*/
|
|
return is;
|
|
}
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return NULL;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_ipsmove */
|
|
/* Returns: Nil */
|
|
/* Parameters: is(I) - pointer to state table entry */
|
|
/* hv(I) - new hash value for state table entry */
|
|
/* Write Locks: ipf_state */
|
|
/* */
|
|
/* Move a state entry from one position in the hash table to another. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static void fr_ipsmove(is, hv)
|
|
ipstate_t *is;
|
|
u_int hv;
|
|
{
|
|
ipstate_t **isp;
|
|
u_int hvm;
|
|
|
|
ASSERT(rw_read_locked(&ipf_state.ipf_lk) == 0);
|
|
|
|
hvm = is->is_hv;
|
|
/*
|
|
* Remove the hash from the old location...
|
|
*/
|
|
isp = is->is_phnext;
|
|
if (is->is_hnext)
|
|
is->is_hnext->is_phnext = isp;
|
|
*isp = is->is_hnext;
|
|
if (ips_table[hvm] == NULL)
|
|
ips_stats.iss_inuse--;
|
|
ips_stats.iss_bucketlen[hvm]--;
|
|
|
|
/*
|
|
* ...and put the hash in the new one.
|
|
*/
|
|
hvm = DOUBLE_HASH(hv);
|
|
is->is_hv = hvm;
|
|
isp = &ips_table[hvm];
|
|
if (*isp)
|
|
(*isp)->is_phnext = &is->is_hnext;
|
|
else
|
|
ips_stats.iss_inuse++;
|
|
ips_stats.iss_bucketlen[hvm]++;
|
|
is->is_phnext = isp;
|
|
is->is_hnext = *isp;
|
|
*isp = is;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_stlookup */
|
|
/* Returns: ipstate_t* - NULL == no matching state found, */
|
|
/* else pointer to state information is returned */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* tcp(I) - pointer to TCP/UDP header. */
|
|
/* */
|
|
/* Search the state table for a matching entry to the packet described by */
|
|
/* the contents of *fin. */
|
|
/* */
|
|
/* If we return NULL then no lock on ipf_state is held. */
|
|
/* If we return non-null then a read-lock on ipf_state is held. */
|
|
/* ------------------------------------------------------------------------ */
|
|
ipstate_t *fr_stlookup(fin, tcp, ifqp)
|
|
fr_info_t *fin;
|
|
tcphdr_t *tcp;
|
|
ipftq_t **ifqp;
|
|
{
|
|
u_int hv, hvm, pr, v, tryagain;
|
|
ipstate_t *is, **isp;
|
|
u_short dport, sport;
|
|
i6addr_t src, dst;
|
|
struct icmp *ic;
|
|
ipftq_t *ifq;
|
|
int oow;
|
|
|
|
is = NULL;
|
|
ifq = NULL;
|
|
tcp = fin->fin_dp;
|
|
ic = (struct icmp *)tcp;
|
|
hv = (pr = fin->fin_fi.fi_p);
|
|
src = fin->fin_fi.fi_src;
|
|
dst = fin->fin_fi.fi_dst;
|
|
hv += src.in4.s_addr;
|
|
hv += dst.in4.s_addr;
|
|
|
|
v = fin->fin_fi.fi_v;
|
|
#ifdef USE_INET6
|
|
if (v == 6) {
|
|
hv += fin->fin_fi.fi_src.i6[1];
|
|
hv += fin->fin_fi.fi_src.i6[2];
|
|
hv += fin->fin_fi.fi_src.i6[3];
|
|
|
|
if ((fin->fin_p == IPPROTO_ICMPV6) &&
|
|
IN6_IS_ADDR_MULTICAST(&fin->fin_fi.fi_dst.in6)) {
|
|
hv -= dst.in4.s_addr;
|
|
} else {
|
|
hv += fin->fin_fi.fi_dst.i6[1];
|
|
hv += fin->fin_fi.fi_dst.i6[2];
|
|
hv += fin->fin_fi.fi_dst.i6[3];
|
|
}
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* Search the hash table for matching packet header info.
|
|
*/
|
|
switch (pr)
|
|
{
|
|
#ifdef USE_INET6
|
|
case IPPROTO_ICMPV6 :
|
|
tryagain = 0;
|
|
if (v == 6) {
|
|
if ((ic->icmp_type == ICMP6_ECHO_REQUEST) ||
|
|
(ic->icmp_type == ICMP6_ECHO_REPLY)) {
|
|
hv += ic->icmp_id;
|
|
}
|
|
}
|
|
READ_ENTER(&ipf_state);
|
|
icmp6again:
|
|
hvm = DOUBLE_HASH(hv);
|
|
for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) {
|
|
isp = &is->is_hnext;
|
|
if ((is->is_p != pr) || (is->is_v != v))
|
|
continue;
|
|
is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP);
|
|
if (is != NULL &&
|
|
fr_matchicmpqueryreply(v, &is->is_icmp,
|
|
ic, fin->fin_rev)) {
|
|
if (fin->fin_rev)
|
|
ifq = &ips_icmpacktq;
|
|
else
|
|
ifq = &ips_icmptq;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (is != NULL) {
|
|
if ((tryagain != 0) && !(is->is_flags & SI_W_DADDR)) {
|
|
hv += fin->fin_fi.fi_src.i6[0];
|
|
hv += fin->fin_fi.fi_src.i6[1];
|
|
hv += fin->fin_fi.fi_src.i6[2];
|
|
hv += fin->fin_fi.fi_src.i6[3];
|
|
fr_ipsmove(is, hv);
|
|
MUTEX_DOWNGRADE(&ipf_state);
|
|
}
|
|
break;
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
|
|
/*
|
|
* No matching icmp state entry. Perhaps this is a
|
|
* response to another state entry.
|
|
*
|
|
* XXX With some ICMP6 packets, the "other" address is already
|
|
* in the packet, after the ICMP6 header, and this could be
|
|
* used in place of the multicast address. However, taking
|
|
* advantage of this requires some significant code changes
|
|
* to handle the specific types where that is the case.
|
|
*/
|
|
if ((ips_stats.iss_wild != 0) && (v == 6) && (tryagain == 0) &&
|
|
!IN6_IS_ADDR_MULTICAST(&fin->fin_fi.fi_src.in6)) {
|
|
hv -= fin->fin_fi.fi_src.i6[0];
|
|
hv -= fin->fin_fi.fi_src.i6[1];
|
|
hv -= fin->fin_fi.fi_src.i6[2];
|
|
hv -= fin->fin_fi.fi_src.i6[3];
|
|
tryagain = 1;
|
|
WRITE_ENTER(&ipf_state);
|
|
goto icmp6again;
|
|
}
|
|
|
|
is = fr_checkicmp6matchingstate(fin);
|
|
if (is != NULL)
|
|
return is;
|
|
break;
|
|
#endif
|
|
|
|
case IPPROTO_ICMP :
|
|
if (v == 4) {
|
|
hv += ic->icmp_id;
|
|
}
|
|
hv = DOUBLE_HASH(hv);
|
|
READ_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) {
|
|
isp = &is->is_hnext;
|
|
if ((is->is_p != pr) || (is->is_v != v))
|
|
continue;
|
|
is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP);
|
|
if (is != NULL &&
|
|
fr_matchicmpqueryreply(v, &is->is_icmp,
|
|
ic, fin->fin_rev)) {
|
|
if (fin->fin_rev)
|
|
ifq = &ips_icmpacktq;
|
|
else
|
|
ifq = &ips_icmptq;
|
|
break;
|
|
}
|
|
}
|
|
if (is == NULL) {
|
|
RWLOCK_EXIT(&ipf_state);
|
|
}
|
|
break;
|
|
|
|
case IPPROTO_TCP :
|
|
case IPPROTO_UDP :
|
|
ifqp = NULL;
|
|
sport = htons(fin->fin_data[0]);
|
|
hv += sport;
|
|
dport = htons(fin->fin_data[1]);
|
|
hv += dport;
|
|
oow = 0;
|
|
tryagain = 0;
|
|
READ_ENTER(&ipf_state);
|
|
retry_tcpudp:
|
|
hvm = DOUBLE_HASH(hv);
|
|
for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) {
|
|
isp = &is->is_hnext;
|
|
if ((is->is_p != pr) || (is->is_v != v))
|
|
continue;
|
|
fin->fin_flx &= ~FI_OOW;
|
|
is = fr_matchsrcdst(fin, is, &src, &dst, tcp, FI_CMP);
|
|
if (is != NULL) {
|
|
if (pr == IPPROTO_TCP) {
|
|
if (!fr_tcpstate(fin, tcp, is)) {
|
|
oow |= fin->fin_flx & FI_OOW;
|
|
continue;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
if (is != NULL) {
|
|
if (tryagain &&
|
|
!(is->is_flags & (SI_CLONE|SI_WILDP|SI_WILDA))) {
|
|
hv += dport;
|
|
hv += sport;
|
|
fr_ipsmove(is, hv);
|
|
MUTEX_DOWNGRADE(&ipf_state);
|
|
}
|
|
break;
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
|
|
if (!tryagain && ips_stats.iss_wild) {
|
|
hv -= dport;
|
|
hv -= sport;
|
|
tryagain = 1;
|
|
WRITE_ENTER(&ipf_state);
|
|
goto retry_tcpudp;
|
|
}
|
|
fin->fin_flx |= oow;
|
|
break;
|
|
|
|
#if 0
|
|
case IPPROTO_GRE :
|
|
gre = fin->fin_dp;
|
|
if (GRE_REV(gre->gr_flags) == 1) {
|
|
hv += gre->gr_call;
|
|
}
|
|
/* FALLTHROUGH */
|
|
#endif
|
|
default :
|
|
ifqp = NULL;
|
|
hvm = DOUBLE_HASH(hv);
|
|
READ_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) {
|
|
isp = &is->is_hnext;
|
|
if ((is->is_p != pr) || (is->is_v != v))
|
|
continue;
|
|
is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP);
|
|
if (is != NULL) {
|
|
ifq = &ips_iptq;
|
|
break;
|
|
}
|
|
}
|
|
if (is == NULL) {
|
|
RWLOCK_EXIT(&ipf_state);
|
|
}
|
|
break;
|
|
}
|
|
|
|
if ((is != NULL) && ((is->is_sti.tqe_flags & TQE_RULEBASED) != 0) &&
|
|
(is->is_tqehead[fin->fin_rev] != NULL))
|
|
ifq = is->is_tqehead[fin->fin_rev];
|
|
if (ifq != NULL && ifqp != NULL)
|
|
*ifqp = ifq;
|
|
return is;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_updatestate */
|
|
/* Returns: Nil */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* is(I) - pointer to state table entry */
|
|
/* Read Locks: ipf_state */
|
|
/* */
|
|
/* Updates packet and byte counters for a newly received packet. Seeds the */
|
|
/* fragment cache with a new entry as required. */
|
|
/* ------------------------------------------------------------------------ */
|
|
void fr_updatestate(fin, is, ifq)
|
|
fr_info_t *fin;
|
|
ipstate_t *is;
|
|
ipftq_t *ifq;
|
|
{
|
|
ipftqent_t *tqe;
|
|
int i, pass;
|
|
|
|
i = (fin->fin_rev << 1) + fin->fin_out;
|
|
|
|
/*
|
|
* For TCP packets, ifq == NULL. For all others, check if this new
|
|
* queue is different to the last one it was on and move it if so.
|
|
*/
|
|
tqe = &is->is_sti;
|
|
MUTEX_ENTER(&is->is_lock);
|
|
if ((tqe->tqe_flags & TQE_RULEBASED) != 0)
|
|
ifq = is->is_tqehead[fin->fin_rev];
|
|
|
|
if (ifq != NULL)
|
|
fr_movequeue(tqe, tqe->tqe_ifq, ifq);
|
|
|
|
is->is_pkts[i]++;
|
|
is->is_bytes[i] += fin->fin_plen;
|
|
MUTEX_EXIT(&is->is_lock);
|
|
|
|
#ifdef IPFILTER_SYNC
|
|
if (is->is_flags & IS_STATESYNC)
|
|
ipfsync_update(SMC_STATE, fin, is->is_sync);
|
|
#endif
|
|
|
|
ATOMIC_INCL(ips_stats.iss_hits);
|
|
|
|
fin->fin_fr = is->is_rule;
|
|
|
|
/*
|
|
* If this packet is a fragment and the rule says to track fragments,
|
|
* then create a new fragment cache entry.
|
|
*/
|
|
pass = is->is_pass;
|
|
if ((fin->fin_flx & FI_FRAG) && FR_ISPASS(pass))
|
|
(void) fr_newfrag(fin, pass ^ FR_KEEPSTATE);
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_checkstate */
|
|
/* Returns: frentry_t* - NULL == search failed, */
|
|
/* else pointer to rule for matching state */
|
|
/* Parameters: ifp(I) - pointer to interface */
|
|
/* passp(I) - pointer to filtering result flags */
|
|
/* */
|
|
/* Check if a packet is associated with an entry in the state table. */
|
|
/* ------------------------------------------------------------------------ */
|
|
frentry_t *fr_checkstate(fin, passp)
|
|
fr_info_t *fin;
|
|
u_32_t *passp;
|
|
{
|
|
ipstate_t *is;
|
|
frentry_t *fr;
|
|
tcphdr_t *tcp;
|
|
ipftq_t *ifq;
|
|
u_int pass;
|
|
|
|
if (fr_state_lock || (ips_list == NULL) ||
|
|
(fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD)))
|
|
return NULL;
|
|
|
|
is = NULL;
|
|
if ((fin->fin_flx & FI_TCPUDP) ||
|
|
(fin->fin_fi.fi_p == IPPROTO_ICMP)
|
|
#ifdef USE_INET6
|
|
|| (fin->fin_fi.fi_p == IPPROTO_ICMPV6)
|
|
#endif
|
|
)
|
|
tcp = fin->fin_dp;
|
|
else
|
|
tcp = NULL;
|
|
|
|
/*
|
|
* Search the hash table for matching packet header info.
|
|
*/
|
|
ifq = NULL;
|
|
is = fin->fin_state;
|
|
if (is == NULL)
|
|
is = fr_stlookup(fin, tcp, &ifq);
|
|
switch (fin->fin_p)
|
|
{
|
|
#ifdef USE_INET6
|
|
case IPPROTO_ICMPV6 :
|
|
if (is != NULL)
|
|
break;
|
|
if (fin->fin_v == 6) {
|
|
is = fr_checkicmp6matchingstate(fin);
|
|
if (is != NULL)
|
|
goto matched;
|
|
}
|
|
break;
|
|
#endif
|
|
case IPPROTO_ICMP :
|
|
if (is != NULL)
|
|
break;
|
|
/*
|
|
* No matching icmp state entry. Perhaps this is a
|
|
* response to another state entry.
|
|
*/
|
|
is = fr_checkicmpmatchingstate(fin);
|
|
if (is != NULL)
|
|
goto matched;
|
|
break;
|
|
case IPPROTO_TCP :
|
|
if (is == NULL)
|
|
break;
|
|
|
|
if (is->is_pass & FR_NEWISN) {
|
|
if (fin->fin_out == 0)
|
|
fr_fixinisn(fin, is);
|
|
else if (fin->fin_out == 1)
|
|
fr_fixoutisn(fin, is);
|
|
}
|
|
break;
|
|
default :
|
|
if (fin->fin_rev)
|
|
ifq = &ips_udpacktq;
|
|
else
|
|
ifq = &ips_udptq;
|
|
break;
|
|
}
|
|
if (is == NULL) {
|
|
ATOMIC_INCL(ips_stats.iss_miss);
|
|
return NULL;
|
|
}
|
|
|
|
matched:
|
|
fr = is->is_rule;
|
|
if (fr != NULL) {
|
|
if ((fin->fin_out == 0) && (fr->fr_nattag.ipt_num[0] != 0)) {
|
|
if (fin->fin_nattag == NULL)
|
|
return NULL;
|
|
if (fr_matchtag(&fr->fr_nattag, fin->fin_nattag) != 0)
|
|
return NULL;
|
|
}
|
|
(void) strncpy(fin->fin_group, fr->fr_group, FR_GROUPLEN);
|
|
fin->fin_icode = fr->fr_icode;
|
|
}
|
|
|
|
fin->fin_rule = is->is_rulen;
|
|
pass = is->is_pass;
|
|
fr_updatestate(fin, is, ifq);
|
|
if (fin->fin_out == 1)
|
|
fin->fin_nat = is->is_nat[fin->fin_rev];
|
|
|
|
fin->fin_state = is;
|
|
is->is_touched = fr_ticks;
|
|
MUTEX_ENTER(&is->is_lock);
|
|
is->is_ref++;
|
|
MUTEX_EXIT(&is->is_lock);
|
|
RWLOCK_EXIT(&ipf_state);
|
|
fin->fin_flx |= FI_STATE;
|
|
if ((pass & FR_LOGFIRST) != 0)
|
|
pass &= ~(FR_LOGFIRST|FR_LOG);
|
|
*passp = pass;
|
|
return fr;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_fixoutisn */
|
|
/* Returns: Nil */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* is(I) - pointer to master state structure */
|
|
/* */
|
|
/* Called only for outbound packets, adjusts the sequence number and the */
|
|
/* TCP checksum to match that change. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static void fr_fixoutisn(fin, is)
|
|
fr_info_t *fin;
|
|
ipstate_t *is;
|
|
{
|
|
tcphdr_t *tcp;
|
|
int rev;
|
|
u_32_t seq;
|
|
|
|
tcp = fin->fin_dp;
|
|
rev = fin->fin_rev;
|
|
if ((is->is_flags & IS_ISNSYN) != 0) {
|
|
if (rev == 0) {
|
|
seq = ntohl(tcp->th_seq);
|
|
seq += is->is_isninc[0];
|
|
tcp->th_seq = htonl(seq);
|
|
fix_outcksum(fin, &tcp->th_sum, is->is_sumd[0]);
|
|
}
|
|
}
|
|
if ((is->is_flags & IS_ISNACK) != 0) {
|
|
if (rev == 1) {
|
|
seq = ntohl(tcp->th_seq);
|
|
seq += is->is_isninc[1];
|
|
tcp->th_seq = htonl(seq);
|
|
fix_outcksum(fin, &tcp->th_sum, is->is_sumd[1]);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_fixinisn */
|
|
/* Returns: Nil */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* is(I) - pointer to master state structure */
|
|
/* */
|
|
/* Called only for inbound packets, adjusts the acknowledge number and the */
|
|
/* TCP checksum to match that change. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static void fr_fixinisn(fin, is)
|
|
fr_info_t *fin;
|
|
ipstate_t *is;
|
|
{
|
|
tcphdr_t *tcp;
|
|
int rev;
|
|
u_32_t ack;
|
|
|
|
tcp = fin->fin_dp;
|
|
rev = fin->fin_rev;
|
|
if ((is->is_flags & IS_ISNSYN) != 0) {
|
|
if (rev == 1) {
|
|
ack = ntohl(tcp->th_ack);
|
|
ack -= is->is_isninc[0];
|
|
tcp->th_ack = htonl(ack);
|
|
fix_incksum(fin, &tcp->th_sum, is->is_sumd[0]);
|
|
}
|
|
}
|
|
if ((is->is_flags & IS_ISNACK) != 0) {
|
|
if (rev == 0) {
|
|
ack = ntohl(tcp->th_ack);
|
|
ack -= is->is_isninc[1];
|
|
tcp->th_ack = htonl(ack);
|
|
fix_incksum(fin, &tcp->th_sum, is->is_sumd[1]);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_statesync */
|
|
/* Returns: Nil */
|
|
/* Parameters: ifp(I) - pointer to interface */
|
|
/* */
|
|
/* Walk through all state entries and if an interface pointer match is */
|
|
/* found then look it up again, based on its name in case the pointer has */
|
|
/* changed since last time. */
|
|
/* */
|
|
/* If ifp is passed in as being non-null then we are only doing updates for */
|
|
/* existing, matching, uses of it. */
|
|
/* ------------------------------------------------------------------------ */
|
|
void fr_statesync(ifp)
|
|
void *ifp;
|
|
{
|
|
ipstate_t *is;
|
|
int i;
|
|
|
|
if (fr_running <= 0)
|
|
return;
|
|
|
|
WRITE_ENTER(&ipf_state);
|
|
|
|
if (fr_running <= 0) {
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return;
|
|
}
|
|
|
|
for (is = ips_list; is; is = is->is_next) {
|
|
/*
|
|
* Look up all the interface names in the state entry.
|
|
*/
|
|
for (i = 0; i < 4; i++) {
|
|
if (ifp == NULL || ifp == is->is_ifp[i])
|
|
is->is_ifp[i] = fr_resolvenic(is->is_ifname[i],
|
|
is->is_v);
|
|
}
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_delstate */
|
|
/* Returns: Nil */
|
|
/* Parameters: is(I) - pointer to state structure to delete */
|
|
/* why(I) - if not 0, log reason why it was deleted */
|
|
/* Write Locks: ipf_state */
|
|
/* */
|
|
/* Deletes a state entry from the enumerated list as well as the hash table */
|
|
/* and timeout queue lists. Make adjustments to hash table statistics and */
|
|
/* global counters as required. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static void fr_delstate(is, why)
|
|
ipstate_t *is;
|
|
int why;
|
|
{
|
|
|
|
ASSERT(rw_read_locked(&ipf_state.ipf_lk) == 0);
|
|
|
|
/*
|
|
* Since we want to delete this, remove it from the state table,
|
|
* where it can be found & used, first.
|
|
*/
|
|
if (is->is_pnext != NULL) {
|
|
*is->is_pnext = is->is_next;
|
|
|
|
if (is->is_next != NULL)
|
|
is->is_next->is_pnext = is->is_pnext;
|
|
|
|
is->is_pnext = NULL;
|
|
is->is_next = NULL;
|
|
}
|
|
|
|
if (is->is_phnext != NULL) {
|
|
*is->is_phnext = is->is_hnext;
|
|
if (is->is_hnext != NULL)
|
|
is->is_hnext->is_phnext = is->is_phnext;
|
|
if (ips_table[is->is_hv] == NULL)
|
|
ips_stats.iss_inuse--;
|
|
ips_stats.iss_bucketlen[is->is_hv]--;
|
|
|
|
is->is_phnext = NULL;
|
|
is->is_hnext = NULL;
|
|
}
|
|
|
|
/*
|
|
* Because ips_stats.iss_wild is a count of entries in the state
|
|
* table that have wildcard flags set, only decerement it once
|
|
* and do it here.
|
|
*/
|
|
if (is->is_flags & (SI_WILDP|SI_WILDA)) {
|
|
if (!(is->is_flags & SI_CLONED)) {
|
|
ATOMIC_DECL(ips_stats.iss_wild);
|
|
}
|
|
is->is_flags &= ~(SI_WILDP|SI_WILDA);
|
|
}
|
|
|
|
/*
|
|
* Next, remove it from the timeout queue it is in.
|
|
*/
|
|
fr_deletequeueentry(&is->is_sti);
|
|
|
|
if (is->is_me != NULL) {
|
|
*is->is_me = NULL;
|
|
is->is_me = NULL;
|
|
}
|
|
|
|
/*
|
|
* If it is still in use by something else, do not go any further,
|
|
* but note that at this point it is now an orphan.
|
|
*/
|
|
is->is_ref--;
|
|
if (is->is_ref > 0)
|
|
return;
|
|
|
|
if (is->is_tqehead[0] != NULL) {
|
|
if (fr_deletetimeoutqueue(is->is_tqehead[0]) == 0)
|
|
fr_freetimeoutqueue(is->is_tqehead[0]);
|
|
}
|
|
if (is->is_tqehead[1] != NULL) {
|
|
if (fr_deletetimeoutqueue(is->is_tqehead[1]) == 0)
|
|
fr_freetimeoutqueue(is->is_tqehead[1]);
|
|
}
|
|
|
|
#ifdef IPFILTER_SYNC
|
|
if (is->is_sync)
|
|
ipfsync_del(is->is_sync);
|
|
#endif
|
|
#ifdef IPFILTER_SCAN
|
|
(void) ipsc_detachis(is);
|
|
#endif
|
|
|
|
if (ipstate_logging != 0 && why != 0)
|
|
ipstate_log(is, why);
|
|
|
|
if (is->is_rule != NULL) {
|
|
is->is_rule->fr_statecnt--;
|
|
(void)fr_derefrule(&is->is_rule);
|
|
}
|
|
|
|
MUTEX_DESTROY(&is->is_lock);
|
|
KFREE(is);
|
|
ips_num--;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_timeoutstate */
|
|
/* Returns: Nil */
|
|
/* Parameters: Nil */
|
|
/* */
|
|
/* Slowly expire held state for thingslike UDP and ICMP. The algorithm */
|
|
/* used here is to keep the queue sorted with the oldest things at the top */
|
|
/* and the youngest at the bottom. So if the top one doesn't need to be */
|
|
/* expired then neither will any under it. */
|
|
/* ------------------------------------------------------------------------ */
|
|
void fr_timeoutstate()
|
|
{
|
|
ipftq_t *ifq, *ifqnext;
|
|
ipftqent_t *tqe, *tqn;
|
|
ipstate_t *is;
|
|
#if defined(USE_SPL) && defined(_KERNEL)
|
|
int s;
|
|
#endif
|
|
|
|
SPL_NET(s);
|
|
WRITE_ENTER(&ipf_state);
|
|
for (ifq = ips_tqtqb; ifq != NULL; ifq = ifq->ifq_next)
|
|
for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) {
|
|
if (tqe->tqe_die > fr_ticks)
|
|
break;
|
|
tqn = tqe->tqe_next;
|
|
is = tqe->tqe_parent;
|
|
fr_delstate(is, ISL_EXPIRE);
|
|
}
|
|
|
|
for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) {
|
|
ifqnext = ifq->ifq_next;
|
|
|
|
for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) {
|
|
if (tqe->tqe_die > fr_ticks)
|
|
break;
|
|
tqn = tqe->tqe_next;
|
|
is = tqe->tqe_parent;
|
|
fr_delstate(is, ISL_EXPIRE);
|
|
}
|
|
}
|
|
|
|
for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) {
|
|
ifqnext = ifq->ifq_next;
|
|
|
|
if (((ifq->ifq_flags & IFQF_DELETE) != 0) &&
|
|
(ifq->ifq_ref == 0)) {
|
|
fr_freetimeoutqueue(ifq);
|
|
}
|
|
}
|
|
|
|
if (fr_state_doflush) {
|
|
(void) fr_state_flush(2, 0);
|
|
fr_state_doflush = 0;
|
|
}
|
|
|
|
RWLOCK_EXIT(&ipf_state);
|
|
SPL_X(s);
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_state_flush */
|
|
/* Returns: int - 0 == success, -1 == failure */
|
|
/* Parameters: Nil */
|
|
/* Write Locks: ipf_state */
|
|
/* */
|
|
/* Flush state tables. Three 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. */
|
|
/* which == 2 : flush TCP connections which have been idle for a long time, */
|
|
/* starting at > 4 days idle and working back in successive half-*/
|
|
/* days to at most 12 hours old. If this fails to free enough */
|
|
/* slots then work backwards in half hour slots to 30 minutes. */
|
|
/* If that too fails, then work backwards in 30 second intervals */
|
|
/* for the last 30 minutes to at worst 30 seconds idle. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static int fr_state_flush(which, proto)
|
|
int which, proto;
|
|
{
|
|
ipftq_t *ifq, *ifqnext;
|
|
ipftqent_t *tqe, *tqn;
|
|
ipstate_t *is, **isp;
|
|
int delete, removed;
|
|
long try, maxtick;
|
|
u_long interval;
|
|
#if defined(_KERNEL) && !defined(MENTAT) && defined(USE_SPL)
|
|
int s;
|
|
#endif
|
|
|
|
removed = 0;
|
|
|
|
SPL_NET(s);
|
|
for (isp = &ips_list; ((is = *isp) != NULL); ) {
|
|
delete = 0;
|
|
|
|
if ((proto != 0) && (is->is_v != proto)) {
|
|
isp = &is->is_next;
|
|
continue;
|
|
}
|
|
|
|
switch (which)
|
|
{
|
|
case 0 :
|
|
delete = 1;
|
|
break;
|
|
case 1 :
|
|
case 2 :
|
|
if (is->is_p != IPPROTO_TCP)
|
|
break;
|
|
if ((is->is_state[0] != IPF_TCPS_ESTABLISHED) ||
|
|
(is->is_state[1] != IPF_TCPS_ESTABLISHED))
|
|
delete = 1;
|
|
break;
|
|
}
|
|
|
|
if (delete) {
|
|
if (is->is_p == IPPROTO_TCP)
|
|
ips_stats.iss_fin++;
|
|
else
|
|
ips_stats.iss_expire++;
|
|
fr_delstate(is, ISL_FLUSH);
|
|
removed++;
|
|
} else
|
|
isp = &is->is_next;
|
|
}
|
|
|
|
if (which != 2) {
|
|
SPL_X(s);
|
|
return removed;
|
|
}
|
|
|
|
/*
|
|
* Asked to remove inactive entries because the table is full, try
|
|
* again, 3 times, if first attempt failed with a different criteria
|
|
* each time. The order tried in must be in decreasing age.
|
|
* Another alternative is to implement random drop and drop N entries
|
|
* at random until N have been freed up.
|
|
*/
|
|
if (fr_ticks - ips_last_force_flush < IPF_TTLVAL(5))
|
|
goto force_flush_skipped;
|
|
ips_last_force_flush = fr_ticks;
|
|
|
|
if (fr_ticks > IPF_TTLVAL(43200))
|
|
interval = IPF_TTLVAL(43200);
|
|
else if (fr_ticks > IPF_TTLVAL(1800))
|
|
interval = IPF_TTLVAL(1800);
|
|
else if (fr_ticks > IPF_TTLVAL(30))
|
|
interval = IPF_TTLVAL(30);
|
|
else
|
|
interval = IPF_TTLVAL(10);
|
|
try = fr_ticks - (fr_ticks - interval);
|
|
if (try < 0)
|
|
goto force_flush_skipped;
|
|
|
|
while (removed == 0) {
|
|
maxtick = fr_ticks - interval;
|
|
if (maxtick < 0)
|
|
break;
|
|
|
|
while (try < maxtick) {
|
|
for (ifq = ips_tqtqb; ifq != NULL;
|
|
ifq = ifq->ifq_next) {
|
|
for (tqn = ifq->ifq_head;
|
|
((tqe = tqn) != NULL); ) {
|
|
if (tqe->tqe_die > try)
|
|
break;
|
|
tqn = tqe->tqe_next;
|
|
is = tqe->tqe_parent;
|
|
fr_delstate(is, ISL_EXPIRE);
|
|
removed++;
|
|
}
|
|
}
|
|
|
|
for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) {
|
|
ifqnext = ifq->ifq_next;
|
|
|
|
for (tqn = ifq->ifq_head;
|
|
((tqe = tqn) != NULL); ) {
|
|
if (tqe->tqe_die > try)
|
|
break;
|
|
tqn = tqe->tqe_next;
|
|
is = tqe->tqe_parent;
|
|
fr_delstate(is, ISL_EXPIRE);
|
|
removed++;
|
|
}
|
|
}
|
|
if (try + interval > maxtick)
|
|
break;
|
|
try += interval;
|
|
}
|
|
|
|
if (removed == 0) {
|
|
if (interval == IPF_TTLVAL(43200)) {
|
|
interval = IPF_TTLVAL(1800);
|
|
} else if (interval == IPF_TTLVAL(1800)) {
|
|
interval = IPF_TTLVAL(30);
|
|
} else if (interval == IPF_TTLVAL(30)) {
|
|
interval = IPF_TTLVAL(10);
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
force_flush_skipped:
|
|
SPL_X(s);
|
|
return removed;
|
|
}
|
|
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_tcp_age */
|
|
/* Returns: int - 1 == state transition made, 0 == no change (rejected) */
|
|
/* Parameters: tq(I) - pointer to timeout queue information */
|
|
/* fin(I) - pointer to packet information */
|
|
/* tqtab(I) - TCP timeout queue table this is in */
|
|
/* flags(I) - flags from state/NAT entry */
|
|
/* */
|
|
/* Rewritten by Arjan de Vet <Arjan.deVet@adv.iae.nl>, 2000-07-29: */
|
|
/* */
|
|
/* - (try to) base state transitions on real evidence only, */
|
|
/* i.e. packets that are sent and have been received by ipfilter; */
|
|
/* diagram 18.12 of TCP/IP volume 1 by W. Richard Stevens was used. */
|
|
/* */
|
|
/* - deal with half-closed connections correctly; */
|
|
/* */
|
|
/* - store the state of the source in state[0] such that ipfstat */
|
|
/* displays the state as source/dest instead of dest/source; the calls */
|
|
/* to fr_tcp_age have been changed accordingly. */
|
|
/* */
|
|
/* Internal Parameters: */
|
|
/* */
|
|
/* state[0] = state of source (host that initiated connection) */
|
|
/* state[1] = state of dest (host that accepted the connection) */
|
|
/* */
|
|
/* dir == 0 : a packet from source to dest */
|
|
/* dir == 1 : a packet from dest to source */
|
|
/* */
|
|
/* Locking: it is assumed that the parent of the tqe structure is locked. */
|
|
/* ------------------------------------------------------------------------ */
|
|
int fr_tcp_age(tqe, fin, tqtab, flags)
|
|
ipftqent_t *tqe;
|
|
fr_info_t *fin;
|
|
ipftq_t *tqtab;
|
|
int flags;
|
|
{
|
|
int dlen, ostate, nstate, rval, dir;
|
|
u_char tcpflags;
|
|
tcphdr_t *tcp;
|
|
|
|
tcp = fin->fin_dp;
|
|
|
|
rval = 0;
|
|
dir = fin->fin_rev;
|
|
tcpflags = tcp->th_flags;
|
|
dlen = fin->fin_plen - fin->fin_hlen - (TCP_OFF(tcp) << 2);
|
|
|
|
if (tcpflags & TH_RST) {
|
|
if (!(tcpflags & TH_PUSH) && !dlen)
|
|
nstate = IPF_TCPS_CLOSED;
|
|
else
|
|
nstate = IPF_TCPS_CLOSE_WAIT;
|
|
rval = 1;
|
|
} else {
|
|
ostate = tqe->tqe_state[1 - dir];
|
|
nstate = tqe->tqe_state[dir];
|
|
|
|
switch (nstate)
|
|
{
|
|
case IPF_TCPS_CLOSED: /* 0 */
|
|
if ((tcpflags & TH_OPENING) == TH_OPENING) {
|
|
/*
|
|
* 'dir' received an S and sends SA in
|
|
* response, CLOSED -> SYN_RECEIVED
|
|
*/
|
|
nstate = IPF_TCPS_SYN_RECEIVED;
|
|
rval = 1;
|
|
} else if ((tcpflags & TH_OPENING) == TH_SYN) {
|
|
/* 'dir' sent S, CLOSED -> SYN_SENT */
|
|
nstate = IPF_TCPS_SYN_SENT;
|
|
rval = 1;
|
|
}
|
|
/*
|
|
* the next piece of code makes it possible to get
|
|
* already established connections into the state table
|
|
* after a restart or reload of the filter rules; this
|
|
* does not work when a strict 'flags S keep state' is
|
|
* used for tcp connections of course
|
|
*/
|
|
if (((flags & IS_TCPFSM) == 0) &&
|
|
((tcpflags & TH_ACKMASK) == TH_ACK)) {
|
|
/*
|
|
* we saw an A, guess 'dir' is in ESTABLISHED
|
|
* mode
|
|
*/
|
|
switch (ostate)
|
|
{
|
|
case IPF_TCPS_CLOSED :
|
|
case IPF_TCPS_SYN_RECEIVED :
|
|
nstate = IPF_TCPS_HALF_ESTAB;
|
|
rval = 1;
|
|
break;
|
|
case IPF_TCPS_HALF_ESTAB :
|
|
case IPF_TCPS_ESTABLISHED :
|
|
nstate = IPF_TCPS_ESTABLISHED;
|
|
rval = 1;
|
|
break;
|
|
default :
|
|
break;
|
|
}
|
|
}
|
|
/*
|
|
* TODO: besides regular ACK packets we can have other
|
|
* packets as well; it is yet to be determined how we
|
|
* should initialize the states in those cases
|
|
*/
|
|
break;
|
|
|
|
case IPF_TCPS_LISTEN: /* 1 */
|
|
/* NOT USED */
|
|
break;
|
|
|
|
case IPF_TCPS_SYN_SENT: /* 2 */
|
|
if ((tcpflags & ~(TH_ECN|TH_CWR)) == TH_SYN) {
|
|
/*
|
|
* A retransmitted SYN packet. We do not reset
|
|
* the timeout here to fr_tcptimeout because a
|
|
* connection connect timeout does not renew
|
|
* after every packet that is sent. We need to
|
|
* set rval so as to indicate the packet has
|
|
* passed the check for its flags being valid
|
|
* in the TCP FSM. Setting rval to 2 has the
|
|
* result of not resetting the timeout.
|
|
*/
|
|
rval = 2;
|
|
} else if ((tcpflags & (TH_SYN|TH_FIN|TH_ACK)) ==
|
|
TH_ACK) {
|
|
/*
|
|
* we see an A from 'dir' which is in SYN_SENT
|
|
* state: 'dir' sent an A in response to an SA
|
|
* which it received, SYN_SENT -> ESTABLISHED
|
|
*/
|
|
nstate = IPF_TCPS_ESTABLISHED;
|
|
rval = 1;
|
|
} else if (tcpflags & TH_FIN) {
|
|
/*
|
|
* we see an F from 'dir' which is in SYN_SENT
|
|
* state and wants to close its side of the
|
|
* connection; SYN_SENT -> FIN_WAIT_1
|
|
*/
|
|
nstate = IPF_TCPS_FIN_WAIT_1;
|
|
rval = 1;
|
|
} else if ((tcpflags & TH_OPENING) == TH_OPENING) {
|
|
/*
|
|
* we see an SA from 'dir' which is already in
|
|
* SYN_SENT state, this means we have a
|
|
* simultaneous open; SYN_SENT -> SYN_RECEIVED
|
|
*/
|
|
nstate = IPF_TCPS_SYN_RECEIVED;
|
|
rval = 1;
|
|
}
|
|
break;
|
|
|
|
case IPF_TCPS_SYN_RECEIVED: /* 3 */
|
|
if ((tcpflags & (TH_SYN|TH_FIN|TH_ACK)) == TH_ACK) {
|
|
/*
|
|
* we see an A from 'dir' which was in
|
|
* SYN_RECEIVED state so it must now be in
|
|
* established state, SYN_RECEIVED ->
|
|
* ESTABLISHED
|
|
*/
|
|
nstate = IPF_TCPS_ESTABLISHED;
|
|
rval = 1;
|
|
} else if ((tcpflags & ~(TH_ECN|TH_CWR)) ==
|
|
TH_OPENING) {
|
|
/*
|
|
* We see an SA from 'dir' which is already in
|
|
* SYN_RECEIVED state.
|
|
*/
|
|
rval = 2;
|
|
} else if (tcpflags & TH_FIN) {
|
|
/*
|
|
* we see an F from 'dir' which is in
|
|
* SYN_RECEIVED state and wants to close its
|
|
* side of the connection; SYN_RECEIVED ->
|
|
* FIN_WAIT_1
|
|
*/
|
|
nstate = IPF_TCPS_FIN_WAIT_1;
|
|
rval = 1;
|
|
}
|
|
break;
|
|
|
|
case IPF_TCPS_HALF_ESTAB: /* 4 */
|
|
if (ostate >= IPF_TCPS_HALF_ESTAB) {
|
|
if ((tcpflags & TH_ACKMASK) == TH_ACK) {
|
|
nstate = IPF_TCPS_ESTABLISHED;
|
|
rval = 1;
|
|
}
|
|
}
|
|
|
|
break;
|
|
|
|
case IPF_TCPS_ESTABLISHED: /* 5 */
|
|
rval = 1;
|
|
if (tcpflags & TH_FIN) {
|
|
/*
|
|
* 'dir' closed its side of the connection;
|
|
* this gives us a half-closed connection;
|
|
* ESTABLISHED -> FIN_WAIT_1
|
|
*/
|
|
nstate = IPF_TCPS_FIN_WAIT_1;
|
|
} else if (tcpflags & TH_ACK) {
|
|
/*
|
|
* an ACK, should we exclude other flags here?
|
|
*/
|
|
if (ostate == IPF_TCPS_FIN_WAIT_1) {
|
|
/*
|
|
* We know the other side did an active
|
|
* close, so we are ACKing the recvd
|
|
* FIN packet (does the window matching
|
|
* code guarantee this?) and go into
|
|
* CLOSE_WAIT state; this gives us a
|
|
* half-closed connection
|
|
*/
|
|
nstate = IPF_TCPS_CLOSE_WAIT;
|
|
} else if (ostate < IPF_TCPS_CLOSE_WAIT) {
|
|
/*
|
|
* still a fully established
|
|
* connection reset timeout
|
|
*/
|
|
nstate = IPF_TCPS_ESTABLISHED;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case IPF_TCPS_CLOSE_WAIT: /* 6 */
|
|
rval = 1;
|
|
if (tcpflags & TH_FIN) {
|
|
/*
|
|
* application closed and 'dir' sent a FIN,
|
|
* we're now going into LAST_ACK state
|
|
*/
|
|
nstate = IPF_TCPS_LAST_ACK;
|
|
} else {
|
|
/*
|
|
* we remain in CLOSE_WAIT because the other
|
|
* side has closed already and we did not
|
|
* close our side yet; reset timeout
|
|
*/
|
|
nstate = IPF_TCPS_CLOSE_WAIT;
|
|
}
|
|
break;
|
|
|
|
case IPF_TCPS_FIN_WAIT_1: /* 7 */
|
|
rval = 1;
|
|
if ((tcpflags & TH_ACK) &&
|
|
ostate > IPF_TCPS_CLOSE_WAIT) {
|
|
/*
|
|
* if the other side is not active anymore
|
|
* it has sent us a FIN packet that we are
|
|
* ack'ing now with an ACK; this means both
|
|
* sides have now closed the connection and
|
|
* we go into TIME_WAIT
|
|
*/
|
|
/*
|
|
* XXX: how do we know we really are ACKing
|
|
* the FIN packet here? does the window code
|
|
* guarantee that?
|
|
*/
|
|
nstate = IPF_TCPS_TIME_WAIT;
|
|
} else {
|
|
/*
|
|
* we closed our side of the connection
|
|
* already but the other side is still active
|
|
* (ESTABLISHED/CLOSE_WAIT); continue with
|
|
* this half-closed connection
|
|
*/
|
|
nstate = IPF_TCPS_FIN_WAIT_1;
|
|
}
|
|
break;
|
|
|
|
case IPF_TCPS_CLOSING: /* 8 */
|
|
/* NOT USED */
|
|
break;
|
|
|
|
case IPF_TCPS_LAST_ACK: /* 9 */
|
|
if (tcpflags & TH_ACK) {
|
|
if ((tcpflags & TH_PUSH) || dlen)
|
|
/*
|
|
* there is still data to be delivered,
|
|
* reset timeout
|
|
*/
|
|
rval = 1;
|
|
else
|
|
rval = 2;
|
|
}
|
|
/*
|
|
* we cannot detect when we go out of LAST_ACK state to
|
|
* CLOSED because that is based on the reception of ACK
|
|
* packets; ipfilter can only detect that a packet
|
|
* has been sent by a host
|
|
*/
|
|
break;
|
|
|
|
case IPF_TCPS_FIN_WAIT_2: /* 10 */
|
|
rval = 1;
|
|
if ((tcpflags & TH_OPENING) == TH_OPENING)
|
|
nstate = IPF_TCPS_SYN_RECEIVED;
|
|
else if (tcpflags & TH_SYN)
|
|
nstate = IPF_TCPS_SYN_SENT;
|
|
break;
|
|
|
|
case IPF_TCPS_TIME_WAIT: /* 11 */
|
|
/* we're in 2MSL timeout now */
|
|
rval = 1;
|
|
break;
|
|
|
|
default :
|
|
#if defined(_KERNEL)
|
|
# if SOLARIS
|
|
cmn_err(CE_NOTE,
|
|
"tcp %lx flags %x si %lx nstate %d ostate %d\n",
|
|
(u_long)tcp, tcpflags, (u_long)tqe,
|
|
nstate, ostate);
|
|
# else
|
|
printf("tcp %lx flags %x si %lx nstate %d ostate %d\n",
|
|
(u_long)tcp, tcpflags, (u_long)tqe,
|
|
nstate, ostate);
|
|
# endif
|
|
# ifdef DIAGNOSTIC
|
|
panic("invalid TCP state");
|
|
# endif
|
|
#else
|
|
abort();
|
|
#endif
|
|
break;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* If rval == 2 then do not update the queue position, but treat the
|
|
* packet as being ok.
|
|
*/
|
|
if (rval == 2)
|
|
rval = 1;
|
|
else if (rval == 1) {
|
|
tqe->tqe_state[dir] = nstate;
|
|
if ((tqe->tqe_flags & TQE_RULEBASED) == 0)
|
|
fr_movequeue(tqe, tqe->tqe_ifq, tqtab + nstate);
|
|
}
|
|
|
|
return rval;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: ipstate_log */
|
|
/* Returns: Nil */
|
|
/* Parameters: is(I) - pointer to state structure */
|
|
/* type(I) - type of log entry to create */
|
|
/* */
|
|
/* Creates a state table log entry using the state structure and type info. */
|
|
/* passed in. Log packet/byte counts, source/destination address and other */
|
|
/* protocol specific information. */
|
|
/* ------------------------------------------------------------------------ */
|
|
void ipstate_log(is, type)
|
|
struct ipstate *is;
|
|
u_int type;
|
|
{
|
|
#ifdef IPFILTER_LOG
|
|
struct ipslog ipsl;
|
|
size_t sizes[1];
|
|
void *items[1];
|
|
int types[1];
|
|
|
|
/*
|
|
* Copy information out of the ipstate_t structure and into the
|
|
* structure used for logging.
|
|
*/
|
|
ipsl.isl_type = type;
|
|
ipsl.isl_pkts[0] = is->is_pkts[0] + is->is_icmppkts[0];
|
|
ipsl.isl_bytes[0] = is->is_bytes[0];
|
|
ipsl.isl_pkts[1] = is->is_pkts[1] + is->is_icmppkts[1];
|
|
ipsl.isl_bytes[1] = is->is_bytes[1];
|
|
ipsl.isl_pkts[2] = is->is_pkts[2] + is->is_icmppkts[2];
|
|
ipsl.isl_bytes[2] = is->is_bytes[2];
|
|
ipsl.isl_pkts[3] = is->is_pkts[3] + is->is_icmppkts[3];
|
|
ipsl.isl_bytes[3] = is->is_bytes[3];
|
|
ipsl.isl_src = is->is_src;
|
|
ipsl.isl_dst = is->is_dst;
|
|
ipsl.isl_p = is->is_p;
|
|
ipsl.isl_v = is->is_v;
|
|
ipsl.isl_flags = is->is_flags;
|
|
ipsl.isl_tag = is->is_tag;
|
|
ipsl.isl_rulen = is->is_rulen;
|
|
(void) strncpy(ipsl.isl_group, is->is_group, FR_GROUPLEN);
|
|
|
|
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.ici_type;
|
|
} else if (ipsl.isl_p == IPPROTO_ICMPV6) {
|
|
ipsl.isl_itype = is->is_icmp.ici_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;
|
|
|
|
if (ipllog(IPL_LOGSTATE, NULL, items, sizes, types, 1)) {
|
|
ATOMIC_INCL(ips_stats.iss_logged);
|
|
} else {
|
|
ATOMIC_INCL(ips_stats.iss_logfail);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
|
|
#ifdef USE_INET6
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_checkicmp6matchingstate */
|
|
/* Returns: ipstate_t* - NULL == no match found, */
|
|
/* else pointer to matching state entry */
|
|
/* Parameters: fin(I) - pointer to packet information */
|
|
/* Locks: NULL == no locks, else Read Lock on ipf_state */
|
|
/* */
|
|
/* If we've got an ICMPv6 error message, using the information stored in */
|
|
/* the ICMPv6 packet, look for a matching state table entry. */
|
|
/* ------------------------------------------------------------------------ */
|
|
static ipstate_t *fr_checkicmp6matchingstate(fin)
|
|
fr_info_t *fin;
|
|
{
|
|
struct icmp6_hdr *ic6, *oic;
|
|
int type, backward, i;
|
|
ipstate_t *is, **isp;
|
|
u_short sport, dport;
|
|
i6addr_t dst, src;
|
|
u_short savelen;
|
|
icmpinfo_t *ic;
|
|
fr_info_t ofin;
|
|
tcphdr_t *tcp;
|
|
ip6_t *oip6;
|
|
u_char pr;
|
|
u_int hv;
|
|
|
|
/*
|
|
* 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 ((fin->fin_v != 6) || (fin->fin_plen < ICMP6ERR_MINPKTLEN))
|
|
return NULL;
|
|
|
|
ic6 = fin->fin_dp;
|
|
type = ic6->icmp6_type;
|
|
/*
|
|
* If it's not an error type, then return
|
|
*/
|
|
if ((type != ICMP6_DST_UNREACH) && (type != ICMP6_PACKET_TOO_BIG) &&
|
|
(type != ICMP6_TIME_EXCEEDED) && (type != ICMP6_PARAM_PROB))
|
|
return NULL;
|
|
|
|
oip6 = (ip6_t *)((char *)ic6 + ICMPERR_ICMPHLEN);
|
|
if (fin->fin_plen < sizeof(*oip6))
|
|
return NULL;
|
|
|
|
bcopy((char *)fin, (char *)&ofin, sizeof(fin));
|
|
ofin.fin_v = 6;
|
|
ofin.fin_ifp = fin->fin_ifp;
|
|
ofin.fin_out = !fin->fin_out;
|
|
ofin.fin_m = NULL; /* if dereferenced, panic XXX */
|
|
ofin.fin_mp = NULL; /* if dereferenced, panic XXX */
|
|
|
|
/*
|
|
* We make a fin entry to be able to feed it to
|
|
* matchsrcdst. Note that not all fields are necessary
|
|
* 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 oip6 in network
|
|
* order. Any change we make must be undone afterwards.
|
|
*/
|
|
savelen = oip6->ip6_plen;
|
|
oip6->ip6_plen = fin->fin_dlen - ICMPERR_ICMPHLEN;
|
|
ofin.fin_flx = FI_NOCKSUM;
|
|
ofin.fin_ip = (ip_t *)oip6;
|
|
ofin.fin_plen = oip6->ip6_plen;
|
|
(void) fr_makefrip(sizeof(*oip6), (ip_t *)oip6, &ofin);
|
|
ofin.fin_flx &= ~(FI_BAD|FI_SHORT);
|
|
oip6->ip6_plen = savelen;
|
|
|
|
if (oip6->ip6_nxt == IPPROTO_ICMPV6) {
|
|
oic = (struct icmp6_hdr *)(oip6 + 1);
|
|
/*
|
|
* an ICMP error can only be generated as a result of an
|
|
* ICMP query, not as the response on an ICMP error
|
|
*
|
|
* XXX theoretically ICMP_ECHOREP and the other reply's are
|
|
* ICMP query's as well, but adding them here seems strange XXX
|
|
*/
|
|
if (!(oic->icmp6_type & ICMP6_INFOMSG_MASK))
|
|
return NULL;
|
|
|
|
/*
|
|
* perform a lookup of the ICMP packet in the state table
|
|
*/
|
|
hv = (pr = oip6->ip6_nxt);
|
|
src.in6 = oip6->ip6_src;
|
|
hv += src.in4.s_addr;
|
|
dst.in6 = oip6->ip6_dst;
|
|
hv += dst.in4.s_addr;
|
|
hv += oic->icmp6_id;
|
|
hv += oic->icmp6_seq;
|
|
hv = DOUBLE_HASH(hv);
|
|
|
|
READ_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) {
|
|
ic = &is->is_icmp;
|
|
isp = &is->is_hnext;
|
|
if ((is->is_p == pr) &&
|
|
!(is->is_pass & FR_NOICMPERR) &&
|
|
(oic->icmp6_id == ic->ici_id) &&
|
|
(oic->icmp6_seq == ic->ici_seq) &&
|
|
(is = fr_matchsrcdst(&ofin, is, &src,
|
|
&dst, NULL, FI_ICMPCMP))) {
|
|
/*
|
|
* in the state table ICMP query's are stored
|
|
* with the type of the corresponding ICMP
|
|
* response. Correct here
|
|
*/
|
|
if (((ic->ici_type == ICMP6_ECHO_REPLY) &&
|
|
(oic->icmp6_type == ICMP6_ECHO_REQUEST)) ||
|
|
(ic->ici_type - 1 == oic->icmp6_type )) {
|
|
ips_stats.iss_hits++;
|
|
backward = IP6_NEQ(&is->is_dst, &src);
|
|
fin->fin_rev = !backward;
|
|
i = (backward << 1) + fin->fin_out;
|
|
is->is_icmppkts[i]++;
|
|
return is;
|
|
}
|
|
}
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return NULL;
|
|
}
|
|
|
|
hv = (pr = oip6->ip6_nxt);
|
|
src.in6 = oip6->ip6_src;
|
|
hv += src.i6[0];
|
|
hv += src.i6[1];
|
|
hv += src.i6[2];
|
|
hv += src.i6[3];
|
|
dst.in6 = oip6->ip6_dst;
|
|
hv += dst.i6[0];
|
|
hv += dst.i6[1];
|
|
hv += dst.i6[2];
|
|
hv += dst.i6[3];
|
|
|
|
if ((oip6->ip6_nxt == IPPROTO_TCP) || (oip6->ip6_nxt == IPPROTO_UDP)) {
|
|
tcp = (tcphdr_t *)(oip6 + 1);
|
|
dport = tcp->th_dport;
|
|
sport = tcp->th_sport;
|
|
hv += dport;
|
|
hv += sport;
|
|
} else
|
|
tcp = NULL;
|
|
hv = DOUBLE_HASH(hv);
|
|
|
|
READ_ENTER(&ipf_state);
|
|
for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) {
|
|
isp = &is->is_hnext;
|
|
/*
|
|
* 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) || (is->is_v != 6) ||
|
|
(is->is_pass & FR_NOICMPERR))
|
|
continue;
|
|
is = fr_matchsrcdst(&ofin, is, &src, &dst, tcp, FI_ICMPCMP);
|
|
if (is != NULL) {
|
|
ips_stats.iss_hits++;
|
|
backward = IP6_NEQ(&is->is_dst, &src);
|
|
fin->fin_rev = !backward;
|
|
i = (backward << 1) + fin->fin_out;
|
|
is->is_icmppkts[i]++;
|
|
/*
|
|
* we deliberately do not touch the timeouts
|
|
* for the accompanying state table entry.
|
|
* It remains to be seen if that is correct. XXX
|
|
*/
|
|
return is;
|
|
}
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_sttab_init */
|
|
/* Returns: Nil */
|
|
/* Parameters: tqp(I) - pointer to an array of timeout queues for TCP */
|
|
/* */
|
|
/* Initialise the array of timeout queues for TCP. */
|
|
/* ------------------------------------------------------------------------ */
|
|
void fr_sttab_init(tqp)
|
|
ipftq_t *tqp;
|
|
{
|
|
int i;
|
|
|
|
for (i = IPF_TCP_NSTATES - 1; i >= 0; i--) {
|
|
tqp[i].ifq_ttl = 0;
|
|
tqp[i].ifq_ref = 1;
|
|
tqp[i].ifq_head = NULL;
|
|
tqp[i].ifq_tail = &tqp[i].ifq_head;
|
|
tqp[i].ifq_next = tqp + i + 1;
|
|
MUTEX_INIT(&tqp[i].ifq_lock, "ipftq tcp tab");
|
|
}
|
|
tqp[IPF_TCP_NSTATES - 1].ifq_next = NULL;
|
|
tqp[IPF_TCPS_CLOSED].ifq_ttl = fr_tcpclosed;
|
|
tqp[IPF_TCPS_LISTEN].ifq_ttl = fr_tcptimeout;
|
|
tqp[IPF_TCPS_SYN_SENT].ifq_ttl = fr_tcptimeout;
|
|
tqp[IPF_TCPS_SYN_RECEIVED].ifq_ttl = fr_tcptimeout;
|
|
tqp[IPF_TCPS_ESTABLISHED].ifq_ttl = fr_tcpidletimeout;
|
|
tqp[IPF_TCPS_CLOSE_WAIT].ifq_ttl = fr_tcphalfclosed;
|
|
tqp[IPF_TCPS_FIN_WAIT_1].ifq_ttl = fr_tcphalfclosed;
|
|
tqp[IPF_TCPS_CLOSING].ifq_ttl = fr_tcptimeout;
|
|
tqp[IPF_TCPS_LAST_ACK].ifq_ttl = fr_tcplastack;
|
|
tqp[IPF_TCPS_FIN_WAIT_2].ifq_ttl = fr_tcpclosewait;
|
|
tqp[IPF_TCPS_TIME_WAIT].ifq_ttl = fr_tcptimeout;
|
|
tqp[IPF_TCPS_HALF_ESTAB].ifq_ttl = fr_tcptimeout;
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_sttab_destroy */
|
|
/* Returns: Nil */
|
|
/* Parameters: tqp(I) - pointer to an array of timeout queues for TCP */
|
|
/* */
|
|
/* Do whatever is necessary to "destroy" each of the entries in the array */
|
|
/* of timeout queues for TCP. */
|
|
/* ------------------------------------------------------------------------ */
|
|
void fr_sttab_destroy(tqp)
|
|
ipftq_t *tqp;
|
|
{
|
|
int i;
|
|
|
|
for (i = IPF_TCP_NSTATES - 1; i >= 0; i--)
|
|
MUTEX_DESTROY(&tqp[i].ifq_lock);
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_statederef */
|
|
/* Returns: Nil */
|
|
/* Parameters: isp(I) - pointer to pointer to state table entry */
|
|
/* */
|
|
/* Decrement the reference counter for this state table entry and free it */
|
|
/* if there are no more things using it. */
|
|
/* */
|
|
/* When operating in userland (ipftest), we have no timers to clear a state */
|
|
/* entry. Therefore, we make a few simple tests before deleting an entry */
|
|
/* outright. We compare states on each side looking for a combination of */
|
|
/* TIME_WAIT (should really be FIN_WAIT_2?) and LAST_ACK. Then we factor */
|
|
/* in packet direction with the interface list to make sure we don't */
|
|
/* prematurely delete an entry on a final inbound packet that's we're also */
|
|
/* supposed to route elsewhere. */
|
|
/* */
|
|
/* Internal parameters: */
|
|
/* state[0] = state of source (host that initiated connection) */
|
|
/* state[1] = state of dest (host that accepted the connection) */
|
|
/* */
|
|
/* dir == 0 : a packet from source to dest */
|
|
/* dir == 1 : a packet from dest to source */
|
|
/* ------------------------------------------------------------------------ */
|
|
void fr_statederef(fin, isp)
|
|
fr_info_t *fin;
|
|
ipstate_t **isp;
|
|
{
|
|
ipstate_t *is = *isp;
|
|
#if 0
|
|
int nstate, ostate, dir, eol;
|
|
|
|
eol = 0; /* End-of-the-line flag. */
|
|
dir = fin->fin_rev;
|
|
ostate = is->is_state[1 - dir];
|
|
nstate = is->is_state[dir];
|
|
/*
|
|
* Determine whether this packet is local or routed. State entries
|
|
* with us as the destination will have an interface list of
|
|
* int1,-,-,int1. Entries with us as the origin run as -,int1,int1,-.
|
|
*/
|
|
if ((fin->fin_p == IPPROTO_TCP) && (fin->fin_out == 0)) {
|
|
if ((strcmp(is->is_ifname[0], is->is_ifname[3]) == 0) &&
|
|
(strcmp(is->is_ifname[1], is->is_ifname[2]) == 0)) {
|
|
if ((dir == 0) &&
|
|
(strcmp(is->is_ifname[1], "-") == 0) &&
|
|
(strcmp(is->is_ifname[0], "-") != 0)) {
|
|
eol = 1;
|
|
} else if ((dir == 1) &&
|
|
(strcmp(is->is_ifname[0], "-") == 0) &&
|
|
(strcmp(is->is_ifname[1], "-") != 0)) {
|
|
eol = 1;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
fin = fin; /* LINT */
|
|
is = *isp;
|
|
*isp = NULL;
|
|
WRITE_ENTER(&ipf_state);
|
|
is->is_ref--;
|
|
if (is->is_ref == 0) {
|
|
is->is_ref++; /* To counter ref-- in fr_delstate() */
|
|
fr_delstate(is, ISL_EXPIRE);
|
|
#ifndef _KERNEL
|
|
#if 0
|
|
} else if (((fin->fin_out == 1) || (eol == 1)) &&
|
|
((ostate == IPF_TCPS_LAST_ACK) &&
|
|
(nstate == IPF_TCPS_TIME_WAIT))) {
|
|
;
|
|
#else
|
|
} else if ((is->is_sti.tqe_state[0] > IPF_TCPS_ESTABLISHED) ||
|
|
(is->is_sti.tqe_state[1] > IPF_TCPS_ESTABLISHED)) {
|
|
#endif
|
|
fr_delstate(is, ISL_ORPHAN);
|
|
#endif
|
|
}
|
|
RWLOCK_EXIT(&ipf_state);
|
|
}
|
|
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
/* Function: fr_setstatequeue */
|
|
/* Returns: Nil */
|
|
/* Parameters: is(I) - pointer to state structure */
|
|
/* rev(I) - forward(0) or reverse(1) direction */
|
|
/* Locks: ipf_state (read or write) */
|
|
/* */
|
|
/* Put the state entry on its default queue entry, using rev as a helped in */
|
|
/* determining which queue it should be placed on. */
|
|
/* ------------------------------------------------------------------------ */
|
|
void fr_setstatequeue(is, rev)
|
|
ipstate_t *is;
|
|
int rev;
|
|
{
|
|
ipftq_t *oifq, *nifq;
|
|
|
|
|
|
if ((is->is_sti.tqe_flags & TQE_RULEBASED) != 0)
|
|
nifq = is->is_tqehead[rev];
|
|
else
|
|
nifq = NULL;
|
|
|
|
if (nifq == NULL) {
|
|
switch (is->is_p)
|
|
{
|
|
#ifdef USE_INET6
|
|
case IPPROTO_ICMPV6 :
|
|
if (rev == 1)
|
|
nifq = &ips_icmpacktq;
|
|
else
|
|
nifq = &ips_icmptq;
|
|
break;
|
|
#endif
|
|
case IPPROTO_ICMP :
|
|
if (rev == 1)
|
|
nifq = &ips_icmpacktq;
|
|
else
|
|
nifq = &ips_icmptq;
|
|
break;
|
|
case IPPROTO_TCP :
|
|
nifq = ips_tqtqb + is->is_state[rev];
|
|
break;
|
|
|
|
case IPPROTO_UDP :
|
|
if (rev == 1)
|
|
nifq = &ips_udpacktq;
|
|
else
|
|
nifq = &ips_udptq;
|
|
break;
|
|
|
|
default :
|
|
nifq = &ips_iptq;
|
|
break;
|
|
}
|
|
}
|
|
|
|
oifq = is->is_sti.tqe_ifq;
|
|
/*
|
|
* If it's currently on a timeout queue, move it from one queue to
|
|
* another, else put it on the end of the newly determined queue.
|
|
*/
|
|
if (oifq != NULL)
|
|
fr_movequeue(&is->is_sti, oifq, nifq);
|
|
else
|
|
fr_queueappend(&is->is_sti, nifq, is);
|
|
return;
|
|
}
|