diff options
Diffstat (limited to 'contrib/ipfilter/ip_state.c')
| -rw-r--r-- | contrib/ipfilter/ip_state.c | 1901 |
1 files changed, 0 insertions, 1901 deletions
diff --git a/contrib/ipfilter/ip_state.c b/contrib/ipfilter/ip_state.c deleted file mode 100644 index 5d6396958eb5..000000000000 --- a/contrib/ipfilter/ip_state.c +++ /dev/null @@ -1,1901 +0,0 @@ -/* - * Copyright (C) 1995-2000 by Darren Reed. - * - * Redistribution and use in source and binary forms are permitted - * provided that this notice is preserved and due credit is given - * to the original author and the contributors. - */ -#if !defined(lint) -static const char sccsid[] = "@(#)ip_state.c 1.8 6/5/96 (C) 1993-2000 Darren Reed"; -static const char rcsid[] = "@(#)$Id: ip_state.c,v 2.30.2.28 2001/01/08 14:04:46 darrenr Exp $"; -#endif - -#include <sys/errno.h> -#include <sys/types.h> -#include <sys/param.h> -#include <sys/file.h> -#if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ - defined(_KERNEL) -# include "opt_ipfilter_log.h" -#endif -#if defined(_KERNEL) && defined(__FreeBSD_version) && \ - (__FreeBSD_version >= 400000) && !defined(KLD_MODULE) -#include "opt_inet6.h" -#endif -#if !defined(_KERNEL) && !defined(KERNEL) && !defined(__KERNEL__) -# include <stdio.h> -# include <stdlib.h> -# include <string.h> -#else -# ifdef linux -# include <linux/kernel.h> -# include <linux/module.h> -# endif -#endif -#if (defined(KERNEL) || defined(_KERNEL)) && (__FreeBSD_version >= 220000) -# include <sys/filio.h> -# include <sys/fcntl.h> -# if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM) -# include "opt_ipfilter.h" -# endif -#else -# include <sys/ioctl.h> -#endif -#include <sys/time.h> -#include <sys/uio.h> -#ifndef linux -# include <sys/protosw.h> -#endif -#include <sys/socket.h> -#if (defined(_KERNEL) || defined(KERNEL)) && !defined(linux) -# include <sys/systm.h> -#endif -#if !defined(__SVR4) && !defined(__svr4__) -# ifndef linux -# include <sys/mbuf.h> -# endif -#else -# include <sys/filio.h> -# include <sys/byteorder.h> -# ifdef _KERNEL -# include <sys/dditypes.h> -# endif -# include <sys/stream.h> -# include <sys/kmem.h> -#endif - -#include <net/if.h> -#ifdef sun -# include <net/af.h> -#endif -#include <net/route.h> -#include <netinet/in.h> -#include <netinet/in_systm.h> -#include <netinet/ip.h> -#include <netinet/tcp.h> -#ifndef linux -# include <netinet/ip_var.h> -# include <netinet/tcp_fsm.h> -#endif -#include <netinet/udp.h> -#include <netinet/ip_icmp.h> -#include "netinet/ip_compat.h" -#include <netinet/tcpip.h> -#include "netinet/ip_fil.h" -#include "netinet/ip_nat.h" -#include "netinet/ip_frag.h" -#include "netinet/ip_proxy.h" -#include "netinet/ip_state.h" -#ifdef USE_INET6 -#include <netinet/icmp6.h> -#endif -#if (__FreeBSD_version >= 300000) -# include <sys/malloc.h> -# if (defined(_KERNEL) || defined(KERNEL)) && !defined(IPFILTER_LKM) -# include <sys/libkern.h> -# include <sys/systm.h> -# endif -#endif - -#ifndef MIN -# define MIN(a,b) (((a)<(b))?(a):(b)) -#endif - -#define TCP_CLOSE (TH_FIN|TH_RST) - -static ipstate_t **ips_table = NULL; -static ipstate_t *ips_list = NULL; -static int ips_num = 0; -static int ips_wild = 0; -static ips_stat_t ips_stats; -#if (SOLARIS || defined(__sgi)) && defined(_KERNEL) -extern KRWLOCK_T ipf_state, ipf_mutex; -extern kmutex_t ipf_rw; -#endif - -#ifdef USE_INET6 -static frentry_t *fr_checkicmp6matchingstate __P((ip6_t *, fr_info_t *)); -#endif -static int fr_matchsrcdst __P((ipstate_t *, union i6addr, union i6addr, - fr_info_t *, tcphdr_t *)); -static frentry_t *fr_checkicmpmatchingstate __P((ip_t *, fr_info_t *)); -static int fr_matchicmpqueryreply __P((int, ipstate_t *, icmphdr_t *)); -static int fr_state_flush __P((int)); -static ips_stat_t *fr_statetstats __P((void)); -static void fr_delstate __P((ipstate_t *)); -static int fr_state_remove __P((caddr_t)); -static void fr_ipsmove __P((ipstate_t **, ipstate_t *, u_int)); -int fr_stputent __P((caddr_t)); -int fr_stgetent __P((caddr_t)); -void fr_stinsert __P((ipstate_t *)); - - -#define FIVE_DAYS (2 * 5 * 86400) /* 5 days: half closed session */ - -#define TCP_MSL 240 /* 2 minutes */ -u_long fr_tcpidletimeout = FIVE_DAYS, - fr_tcpclosewait = 2 * TCP_MSL, - fr_tcplastack = 2 * TCP_MSL, - fr_tcptimeout = 2 * TCP_MSL, - fr_tcpclosed = 120, - fr_tcphalfclosed = 2 * 2 * 3600, /* 2 hours */ - fr_udptimeout = 240, - fr_icmptimeout = 120; -int fr_statemax = IPSTATE_MAX, - fr_statesize = IPSTATE_SIZE; -int fr_state_doflush = 0, - fr_state_lock = 0; - -static int icmpreplytype4[ICMP_MAXTYPE + 1]; - -int fr_stateinit() -{ - int i; - - KMALLOCS(ips_table, ipstate_t **, fr_statesize * sizeof(ipstate_t *)); - if (ips_table != NULL) - bzero((char *)ips_table, fr_statesize * sizeof(ipstate_t *)); - else - return -1; - - /* fill icmp reply type table */ - for (i = 0; i <= ICMP_MAXTYPE; i++) - icmpreplytype4[i] = -1; - icmpreplytype4[ICMP_ECHO] = ICMP_ECHOREPLY; - icmpreplytype4[ICMP_TSTAMP] = ICMP_TSTAMPREPLY; - icmpreplytype4[ICMP_IREQ] = ICMP_IREQREPLY; - icmpreplytype4[ICMP_MASKREQ] = ICMP_MASKREPLY; - - return 0; -} - - -static ips_stat_t *fr_statetstats() -{ - ips_stats.iss_active = ips_num; - ips_stats.iss_table = ips_table; - ips_stats.iss_list = ips_list; - return &ips_stats; -} - - -/* - * flush state tables. two actions currently defined: - * which == 0 : flush all state table entries - * which == 1 : flush TCP connections which have started to close but are - * stuck for some reason. - */ -static int fr_state_flush(which) -int which; -{ - register ipstate_t *is, **isp; -#if defined(_KERNEL) && !SOLARIS - int s; -#endif - int delete, removed = 0; - - SPL_NET(s); - for (isp = &ips_list; (is = *isp); ) { - delete = 0; - - switch (which) - { - case 0 : - delete = 1; - break; - case 1 : - if (is->is_p != IPPROTO_TCP) - break; - if ((is->is_state[0] != TCPS_ESTABLISHED) || - (is->is_state[1] != TCPS_ESTABLISHED)) - delete = 1; - break; - } - - if (delete) { - if (is->is_p == IPPROTO_TCP) - ips_stats.iss_fin++; - else - ips_stats.iss_expire++; -#ifdef IPFILTER_LOG - ipstate_log(is, ISL_FLUSH); -#endif - fr_delstate(is); - removed++; - } else - isp = &is->is_next; - } - SPL_X(s); - return removed; -} - - -static int fr_state_remove(data) -caddr_t data; -{ - ipstate_t *sp, st; - int error; - - sp = &st; - error = IRCOPYPTR(data, (caddr_t)&st, sizeof(st)); - if (error) - return EFAULT; - - for (sp = ips_list; sp; sp = sp->is_next) - if ((sp->is_p == st.is_p) && (sp->is_v == st.is_v) && - !bcmp((char *)&sp->is_src, (char *)&st.is_src, - sizeof(st.is_src)) && - !bcmp((char *)&sp->is_dst, (char *)&st.is_src, - sizeof(st.is_dst)) && - !bcmp((char *)&sp->is_ps, (char *)&st.is_ps, - sizeof(st.is_ps))) { - WRITE_ENTER(&ipf_state); -#ifdef IPFILTER_LOG - ipstate_log(sp, ISL_REMOVE); -#endif - fr_delstate(sp); - RWLOCK_EXIT(&ipf_state); - return 0; - } - return ESRCH; -} - - -int fr_state_ioctl(data, cmd, mode) -caddr_t data; -#if defined(__NetBSD__) || defined(__OpenBSD__) -u_long cmd; -#else -int cmd; -#endif -int mode; -{ - int arg, ret, error = 0; - - switch (cmd) - { - case SIOCDELST : - error = fr_state_remove(data); - break; - case SIOCIPFFL : - error = IRCOPY(data, (caddr_t)&arg, sizeof(arg)); - if (error) - break; - if (arg == 0 || arg == 1) { - WRITE_ENTER(&ipf_state); - ret = fr_state_flush(arg); - RWLOCK_EXIT(&ipf_state); - error = IWCOPY((caddr_t)&ret, data, sizeof(ret)); - } else - error = EINVAL; - break; -#ifdef IPFILTER_LOG - case SIOCIPFFB : - if (!(mode & FWRITE)) - error = EPERM; - else { - int tmp; - - tmp = ipflog_clear(IPL_LOGSTATE); - IWCOPY((char *)&tmp, data, sizeof(tmp)); - } - break; -#endif - case SIOCGETFS : - error = IWCOPYPTR((caddr_t)fr_statetstats(), data, - sizeof(ips_stat_t)); - break; - case FIONREAD : -#ifdef IPFILTER_LOG - arg = (int)iplused[IPL_LOGSTATE]; - error = IWCOPY((caddr_t)&arg, (caddr_t)data, sizeof(arg)); -#endif - break; - case SIOCSTLCK : - error = fr_lock(data, &fr_state_lock); - break; - case SIOCSTPUT : - if (!fr_state_lock) { - error = EACCES; - break; - } - error = fr_stputent(data); - break; - case SIOCSTGET : - if (!fr_state_lock) { - error = EACCES; - break; - } - error = fr_stgetent(data); - break; - default : - error = EINVAL; - break; - } - return error; -} - - -int fr_stgetent(data) -caddr_t data; -{ - register ipstate_t *is, *isn; - ipstate_save_t ips, *ipsp; - int error; - - error = IRCOPY(data, (caddr_t)&ipsp, sizeof(ipsp)); - if (error) - return EFAULT; - error = IRCOPY((caddr_t)ipsp, (caddr_t)&ips, sizeof(ips)); - if (error) - return EFAULT; - - isn = ips.ips_next; - if (!isn) { - 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)); - if (isn->is_rule) - bcopy((char *)isn->is_rule, (char *)&ips.ips_fr, - sizeof(ips.ips_fr)); - error = IWCOPY((caddr_t)&ips, ipsp, sizeof(ips)); - if (error) - error = EFAULT; - return error; -} - - -int fr_stputent(data) -caddr_t data; -{ - register ipstate_t *is, *isn; - ipstate_save_t ips, *ipsp; - int error, out; - frentry_t *fr; - - error = IRCOPY(data, (caddr_t)&ipsp, sizeof(ipsp)); - if (error) - return EFAULT; - error = IRCOPY((caddr_t)ipsp, (caddr_t)&ips, sizeof(ips)); - if (error) - return EFAULT; - - KMALLOC(isn, ipstate_t *); - if (isn == NULL) - return ENOMEM; - - bcopy((char *)&ips.ips_is, (char *)isn, sizeof(*isn)); - fr = isn->is_rule; - if (fr != NULL) { - if (isn->is_flags & FI_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; - if (*fr->fr_ifname) { - fr->fr_ifa = GETUNIT(fr->fr_ifname, fr->fr_v); - if (fr->fr_ifa == NULL) - fr->fr_ifa = (void *)-1; -#ifdef _KERNEL - else { - strncpy(isn->is_ifname[out], - IFNAME(fr->fr_ifa), IFNAMSIZ); - isn->is_ifp[out] = fr->fr_ifa; - } -#endif - } else - fr->fr_ifa = NULL; - /* - * send a copy back to userland of what we ended up - * to allow for verification. - */ - error = IWCOPY((caddr_t)&ips, ipsp, sizeof(ips)); - if (error) { - KFREE(isn); - KFREE(fr); - return EFAULT; - } - } else { - for (is = ips_list; is; is = is->is_next) - if (is->is_rule == fr) - break; - if (!is) { - KFREE(isn); - return ESRCH; - } - } - } - fr_stinsert(isn); - return 0; -} - - -void fr_stinsert(is) -register ipstate_t *is; -{ - register u_int hv = is->is_hv; - - MUTEX_INIT(&is->is_lock, "ipf state entry", NULL); - - is->is_ifname[0][sizeof(is->is_ifname[0]) - 1] = '\0'; - if (is->is_ifname[0][0] != '\0') { - is->is_ifp[0] = GETUNIT(is->is_ifname[0], is->is_v); - } - is->is_ifname[1][sizeof(is->is_ifname[0]) - 1] = '\0'; - if (is->is_ifname[1][0] != '\0') { - is->is_ifp[1] = GETUNIT(is->is_ifname[1], is->is_v); - } - - /* - * add into list table. - */ - if (ips_list) - ips_list->is_pnext = &is->is_next; - is->is_pnext = &ips_list; - is->is_next = ips_list; - ips_list = is; - if (ips_table[hv]) - 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_num++; -} - - -/* - * Create a new ipstate structure and hang it off the hash table. - */ -ipstate_t *fr_addstate(ip, fin, flags) -ip_t *ip; -fr_info_t *fin; -u_int flags; -{ - register tcphdr_t *tcp = NULL; - register ipstate_t *is; - register u_int hv; - ipstate_t ips; - u_int pass; - int out; - - if (fr_state_lock || (fin->fin_off & IP_OFFMASK) || - (fin->fin_fi.fi_fl & FI_SHORT)) - return NULL; - if (ips_num == fr_statemax) { - ips_stats.iss_max++; - fr_state_doflush = 1; - return NULL; - } - out = fin->fin_out; - is = &ips; - bzero((char *)is, sizeof(*is)); - ips.is_age = 1; - ips.is_state[0] = 0; - ips.is_state[1] = 0; - /* - * Copy and calculate... - */ - hv = (is->is_p = 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) { - if (is->is_p == IPPROTO_ICMPV6) { - if (IN6_IS_ADDR_MULTICAST(&is->is_dst.in6)) - flags |= FI_W_DADDR; - if (out) - hv -= is->is_daddr; - else - hv -= is->is_saddr; - } - } -#endif - - switch (is->is_p) - { -#ifdef USE_INET6 - case IPPROTO_ICMPV6 : -#endif - case IPPROTO_ICMP : - { - struct icmp *ic = (struct icmp *)fin->fin_dp; - -#ifdef USE_INET6 - if ((is->is_p == IPPROTO_ICMPV6) && - ((ic->icmp_type & ICMP6_INFOMSG_MASK) == 0)) - return NULL; -#endif - switch (ic->icmp_type) - { -#ifdef USE_INET6 - case ICMP6_ECHO_REQUEST : - is->is_icmp.ics_type = ICMP6_ECHO_REPLY; - hv += (is->is_icmp.ics_id = ic->icmp_id); - hv += (is->is_icmp.ics_seq = ic->icmp_seq); - break; - case ICMP6_MEMBERSHIP_QUERY : - case ND_ROUTER_SOLICIT : - case ND_NEIGHBOR_SOLICIT : - is->is_icmp.ics_type = ic->icmp_type + 1; - break; -#endif - case ICMP_ECHO : - case ICMP_TSTAMP : - case ICMP_IREQ : - case ICMP_MASKREQ : - is->is_icmp.ics_type = ic->icmp_type; - hv += (is->is_icmp.ics_id = ic->icmp_id); - hv += (is->is_icmp.ics_seq = ic->icmp_seq); - break; - default : - return NULL; - } - ATOMIC_INCL(ips_stats.iss_icmp); - is->is_age = fr_icmptimeout; - break; - } - case IPPROTO_TCP : - { - tcp = (tcphdr_t *)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_dport = tcp->th_dport; - is->is_sport = tcp->th_sport; - if ((flags & (FI_W_DPORT|FI_W_SPORT)) == 0) { - hv += tcp->th_dport; - hv += tcp->th_sport; - } - is->is_send = ntohl(tcp->th_seq) + fin->fin_dlen - - (tcp->th_off << 2) + - ((tcp->th_flags & TH_SYN) ? 1 : 0) + - ((tcp->th_flags & TH_FIN) ? 1 : 0); - is->is_maxsend = is->is_send; - is->is_dend = 0; - is->is_maxdwin = 1; - is->is_maxswin = ntohs(tcp->th_win); - if (is->is_maxswin == 0) - is->is_maxswin = 1; - /* - * If we're creating state for a starting connection, start the - * timer on it as we'll never see an error if it fails to - * connect. - */ - ATOMIC_INCL(ips_stats.iss_tcp); - break; - } - case IPPROTO_UDP : - { - tcp = (tcphdr_t *)fin->fin_dp; - - is->is_dport = tcp->th_dport; - is->is_sport = tcp->th_sport; - if ((flags & (FI_W_DPORT|FI_W_SPORT)) == 0) { - hv += tcp->th_dport; - hv += tcp->th_sport; - } - ATOMIC_INCL(ips_stats.iss_udp); - is->is_age = fr_udptimeout; - break; - } - default : - return NULL; - } - - KMALLOC(is, ipstate_t *); - if (is == NULL) { - ATOMIC_INCL(ips_stats.iss_nomem); - return NULL; - } - bcopy((char *)&ips, (char *)is, sizeof(*is)); - hv %= fr_statesize; - is->is_hv = hv; - is->is_rule = fin->fin_fr; - if (is->is_rule != NULL) { - ATOMIC_INC32(is->is_rule->fr_ref); - pass = is->is_rule->fr_flags; - } else - pass = fr_flags; - WRITE_ENTER(&ipf_state); - - is->is_pass = pass; - is->is_pkts = 1; - is->is_bytes = fin->fin_dlen + fin->fin_hlen; - /* - * 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_fi.fi_v; - is->is_opt = fin->fin_fi.fi_optmsk; - is->is_optmsk = 0xffffffff; - is->is_sec = fin->fin_fi.fi_secmsk; - is->is_secmsk = 0xffff; - is->is_auth = fin->fin_fi.fi_auth; - is->is_authmsk = 0xffff; - is->is_flags = fin->fin_fi.fi_fl & FI_CMP; - is->is_flags |= FI_CMP << 4; - is->is_flags |= flags & (FI_WILDP|FI_WILDA); - if (flags & (FI_WILDP|FI_WILDA)) - ips_wild++; - is->is_ifp[1 - out] = NULL; - is->is_ifp[out] = fin->fin_ifp; -#ifdef _KERNEL - strncpy(is->is_ifname[out], IFNAME(fin->fin_ifp), IFNAMSIZ); -#endif - is->is_ifname[1 - out][0] = '\0'; - if (pass & FR_LOGFIRST) - is->is_pass &= ~(FR_LOGFIRST|FR_LOG); - fr_stinsert(is); - if (is->is_p == IPPROTO_TCP) { - MUTEX_ENTER(&is->is_lock); - fr_tcp_age(&is->is_age, is->is_state, fin, - 0); /* 0 = packet from the source */ - MUTEX_EXIT(&is->is_lock); - } -#ifdef IPFILTER_LOG - ipstate_log(is, ISL_NEW); -#endif - RWLOCK_EXIT(&ipf_state); - fin->fin_rev = IP6NEQ(is->is_dst, fin->fin_fi.fi_dst); - if (fin->fin_fi.fi_fl & FI_FRAG) - ipfr_newfrag(ip, fin, pass ^ FR_KEEPSTATE); - return is; -} - - - -/* - * check to see if a packet with TCP headers fits within the TCP window. - * change timeout depending on whether new packet is a SYN-ACK returning for a - * SYN or a RST or FIN which indicate time to close up shop. - */ -int fr_tcpstate(is, fin, ip, tcp) -register ipstate_t *is; -fr_info_t *fin; -ip_t *ip; -tcphdr_t *tcp; -{ - register tcp_seq seq, ack, end; - register int ackskew; - tcpdata_t *fdata, *tdata; - u_short win, maxwin; - int ret = 0; - int source; - - /* - * Find difference between last checked packet and this packet. - */ - source = IP6EQ(fin->fin_fi.fi_src, is->is_src); - fdata = &is->is_tcp.ts_data[!source]; - tdata = &is->is_tcp.ts_data[source]; - seq = ntohl(tcp->th_seq); - ack = ntohl(tcp->th_ack); - win = ntohs(tcp->th_win); - end = seq + fin->fin_dlen - (tcp->th_off << 2) + - ((tcp->th_flags & TH_SYN) ? 1 : 0) + - ((tcp->th_flags & TH_FIN) ? 1 : 0); - - MUTEX_ENTER(&is->is_lock); - if (fdata->td_end == 0) { - /* - * Must be a (outgoing) SYN-ACK in reply to a SYN. - */ - fdata->td_end = end; - fdata->td_maxwin = 1; - fdata->td_maxend = end + 1; - } - - if (!(tcp->th_flags & TH_ACK)) { /* Pretend an ack was sent */ - ack = tdata->td_end; - } else if (((tcp->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) && - (ack == 0)) { - /* gross hack to get around certain broken tcp stacks */ - ack = tdata->td_end; - } - - if (seq == end) - seq = end = fdata->td_end; - - maxwin = tdata->td_maxwin; - ackskew = tdata->td_end - ack; - -#define SEQ_GE(a,b) ((int)((a) - (b)) >= 0) -#define SEQ_GT(a,b) ((int)((a) - (b)) > 0) - if ((SEQ_GE(fdata->td_maxend, end)) && - (SEQ_GE(seq, fdata->td_end - maxwin)) && -/* XXX what about big packets */ -#define MAXACKWINDOW 66000 - (ackskew >= -MAXACKWINDOW) && - (ackskew <= MAXACKWINDOW)) { - /* if ackskew < 0 then this should be due to fragented - * packets. There is no way to know the length of the - * total packet in advance. - * We do know the total length from the fragment cache though. - * Note however that there might be more sessions with - * exactly the same source and destination paramters in the - * state cache (and source and destination is the only stuff - * that is saved in the fragment cache). Note further that - * some TCP connections in the state cache are hashed with - * sport and dport as well which makes it not worthwhile to - * look for them. - * Thus, when ackskew is negative but still seems to belong - * to this session, we bump up the destinations end value. - */ - if (ackskew < 0) - tdata->td_end = ack; - - /* update max window seen */ - if (fdata->td_maxwin < win) - fdata->td_maxwin = win; - if (SEQ_GT(end, fdata->td_end)) - fdata->td_end = end; - if (SEQ_GE(ack + win, tdata->td_maxend)) { - tdata->td_maxend = ack + win; - if (win == 0) - tdata->td_maxend++; - } - - ATOMIC_INCL(ips_stats.iss_hits); - /* - * Nearing end of connection, start timeout. - */ - /* source ? 0 : 1 -> !source */ - fr_tcp_age(&is->is_age, is->is_state, fin, !source); - ret = 1; - } - MUTEX_EXIT(&is->is_lock); - return ret; -} - - -static int fr_matchsrcdst(is, src, dst, fin, tcp) -ipstate_t *is; -union i6addr src, dst; -fr_info_t *fin; -tcphdr_t *tcp; -{ - int ret = 0, rev, out, flags; - u_short sp, dp; - void *ifp; - - rev = fin->fin_rev = IP6NEQ(is->is_dst, dst); - ifp = fin->fin_ifp; - out = fin->fin_out; - - if (tcp != NULL) { - flags = is->is_flags; - sp = tcp->th_sport; - dp = tcp->th_dport; - } else { - flags = is->is_flags & FI_WILDA; - sp = 0; - dp = 0; - } - - if (rev == 0) { - if (!out) { - if (is->is_ifpin == NULL || is->is_ifpin == ifp) - ret = 1; - } else { - if (is->is_ifpout == NULL || is->is_ifpout == ifp) - ret = 1; - } - } else { - if (out) { - if (is->is_ifpin == NULL || is->is_ifpin == ifp) - ret = 1; - } else { - if (is->is_ifpout == NULL || is->is_ifpout == ifp) - ret = 1; - } - } - if (ret == 0) - return 0; - ret = 0; - - if (rev == 0) { - if ( - (IP6EQ(is->is_dst, dst) || (flags & FI_W_DADDR)) && - (IP6EQ(is->is_src, src) || (flags & FI_W_SADDR)) && - (!tcp || ((sp == is->is_sport || flags & FI_W_SPORT) && - (dp == is->is_dport || flags & FI_W_DPORT)))) { - ret = 1; - } - } else { - if ( - (IP6EQ(is->is_dst, src) || (flags & FI_W_DADDR)) && - (IP6EQ(is->is_src, dst) || (flags & FI_W_SADDR)) && - (!tcp || ((sp == is->is_dport || flags & FI_W_DPORT) && - (dp == is->is_sport || flags & FI_W_SPORT)))) { - ret = 1; - } - } - if (ret == 0) - return 0; - - /* - * Whether or not this should be here, is questionable, but the aim - * is to get this out of the main line. - */ - if (tcp == NULL) - flags = is->is_flags & (FI_CMP|(FI_CMP<<4)); - - if (((fin->fin_fi.fi_fl & (flags >> 4)) != (flags & FI_CMP)) || - ((fin->fin_fi.fi_optmsk & is->is_optmsk) != is->is_opt) || - ((fin->fin_fi.fi_secmsk & is->is_secmsk) != is->is_sec) || - ((fin->fin_fi.fi_auth & is->is_authmsk) != is->is_auth)) - return 0; - - if ((flags & (FI_W_SPORT|FI_W_DPORT))) { - if ((flags & FI_W_SPORT) != 0) { - if (rev == 0) { - is->is_sport = sp; - is->is_send = htonl(tcp->th_seq); - } else { - is->is_sport = dp; - is->is_send = htonl(tcp->th_ack); - } - is->is_maxsend = is->is_send + 1; - } else if ((flags & FI_W_DPORT) != 0) { - if (rev == 0) { - is->is_dport = dp; - is->is_dend = htonl(tcp->th_ack); - } else { - is->is_dport = sp; - is->is_dend = htonl(tcp->th_seq); - } - is->is_maxdend = is->is_dend + 1; - } - is->is_flags &= ~(FI_W_SPORT|FI_W_DPORT); - ips_wild--; - } - - ret = -1; - - if (!rev) { - if (out) { - if (!is->is_ifpout) - ret = 1; - } else { - if (!is->is_ifpin) - ret = 0; - } - } else { - if (out) { - if (!is->is_ifpin) - ret = 0; - } else { - if (!is->is_ifpout) - ret = 1; - } - } - - if (ret >= 0) { - is->is_ifp[ret] = ifp; -#ifdef _KERNEL - strncpy(is->is_ifname[out], IFNAME(fin->fin_ifp), - sizeof(is->is_ifname[1])); -#endif - } -#ifdef _KERNEL - if (ret >= 0) { - strncpy(is->is_ifname[out], IFNAME(fin->fin_ifp), - sizeof(is->is_ifname[1])); - } -#endif - return 1; -} - -static int fr_matchicmpqueryreply(v, is, icmp) -int v; -ipstate_t *is; -icmphdr_t *icmp; -{ - if (v == 4) { - /* - * If we matched its type on the way in, then when going out - * it will still be the same type. - */ - if (((icmp->icmp_type == is->is_type) || - (icmpreplytype4[is->is_type] == icmp->icmp_type)) && - (icmp->icmp_id == is->is_icmp.ics_id) && - (icmp->icmp_seq == is->is_icmp.ics_seq)) { - return 1; - }; - } -#ifdef USE_INET6 - else if (is->is_v == 6) { - if ((is->is_type == ICMP6_ECHO_REPLY) && - (icmp->icmp_type == ICMP6_ECHO_REQUEST) && - (icmp->icmp_id == is->is_icmp.ics_id) && - (icmp->icmp_seq == is->is_icmp.ics_seq)) { - return 1; - }; - } -#endif - return 0; -} - -static frentry_t *fr_checkicmpmatchingstate(ip, fin) -ip_t *ip; -fr_info_t *fin; -{ - register ipstate_t *is, **isp; - register u_short sport, dport; - register u_char pr; - union i6addr dst, src; - struct icmp *ic; - u_short savelen; - icmphdr_t *icmp; - fr_info_t ofin; - int type, len; - tcphdr_t *tcp; - frentry_t *fr; - 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 (((ip->ip_v != 4) || (ip->ip_hl != 5)) || - (fin->fin_plen < ICMPERR_MINPKTLEN)) - return NULL; - ic = (struct icmp *)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); - if (fin->fin_plen < ICMPERR_MAXPKTLEN + ((oip->ip_hl - 5) << 2)) - return NULL; - - /* - * Sanity checks. - */ - len = fin->fin_dlen - ICMPERR_ICMPHLEN; - if ((len <= 0) || ((oip->ip_hl << 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 gaurantee it is - * all here now. - */ -#ifdef _KERNEL - { - mb_t *m; - -# if SOLARIS - m = fin->fin_qfm; - if ((char *)oip + len > (char *)m->b_wptr) - return NULL; -# else - m = *(mb_t **)fin->fin_mp; - if ((char *)oip + len > (char *)ip + m->m_len) - return NULL; -# endif - } -#endif - - /* - * in the IPv4 case we must zero the i6addr union otherwise - * the IP6EQ and IP6NEQ 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)); - - if (oip->ip_p == IPPROTO_ICMP) { - icmp = (icmphdr_t *)((char *)oip + (oip->ip_hl << 2)); - - /* - * a 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 += icmp->icmp_seq; - hv %= fr_statesize; - - savelen = oip->ip_len; - oip->ip_len = len; - ofin.fin_v = 4; - fr_makefrip(oip->ip_hl << 2, oip, &ofin); - oip->ip_len = savelen; - ofin.fin_ifp = fin->fin_ifp; - ofin.fin_out = !fin->fin_out; - ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ - - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_hnext) - if ((is->is_p == pr) && (is->is_v == 4) && - fr_matchsrcdst(is, src, dst, &ofin, NULL) && - fr_matchicmpqueryreply(is->is_v, is, icmp)) { - ips_stats.iss_hits++; - is->is_pkts++; - is->is_bytes += ip->ip_len; - fr = is->is_rule; - RWLOCK_EXIT(&ipf_state); - return fr; - } - RWLOCK_EXIT(&ipf_state); - return NULL; - }; - - if ((oip->ip_p != IPPROTO_TCP) && (oip->ip_p != IPPROTO_UDP)) - return NULL; - - tcp = (tcphdr_t *)((char *)oip + (oip->ip_hl << 2)); - dport = tcp->th_dport; - sport = tcp->th_sport; - - hv = (pr = oip->ip_p); - 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 %= fr_statesize; - /* - * we make an fin entry to be able to feed it to - * matchsrcdst note that not all fields are encessary - * but this is the cleanest way. Note further we fill - * in fin_mp such that if someone uses it we'll get - * a kernel panic. fr_matchsrcdst does not use this. - * - * watch out here, as ip is in host order and oip in network - * order. Any change we make must be undone afterwards. - */ - savelen = oip->ip_len; - oip->ip_len = len; - ofin.fin_v = 4; - fr_makefrip(oip->ip_hl << 2, oip, &ofin); - oip->ip_len = savelen; - ofin.fin_ifp = fin->fin_ifp; - ofin.fin_out = !fin->fin_out; - ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_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 == 4) && - fr_matchsrcdst(is, src, dst, &ofin, tcp)) { - fr = is->is_rule; - ips_stats.iss_hits++; - is->is_pkts++; - is->is_bytes += fin->fin_plen; - /* - * we deliberately do not touch the timeouts - * for the accompanying state table entry. - * It remains to be seen if that is correct. XXX - */ - RWLOCK_EXIT(&ipf_state); - return fr; - } - } - RWLOCK_EXIT(&ipf_state); - return NULL; -} - - -static void fr_ipsmove(isp, is, hv) -ipstate_t **isp, *is; -u_int hv; -{ - u_int hvm; - - hvm = is->is_hv; - /* - * Remove the hash from the old location... - */ - if (is->is_hnext) - is->is_hnext->is_phnext = isp; - *isp = is->is_hnext; - if (ips_table[hvm] == NULL) - ips_stats.iss_inuse--; - - /* - * ...and put the hash in the new one. - */ - hvm = hv % fr_statesize; - is->is_hv = hvm; - isp = &ips_table[hvm]; - if (*isp) - (*isp)->is_phnext = &is->is_hnext; - else - ips_stats.iss_inuse++; - is->is_phnext = isp; - is->is_hnext = *isp; - *isp = is; -} - - -/* - * Check if a packet has a registered state. - */ -frentry_t *fr_checkstate(ip, fin) -ip_t *ip; -fr_info_t *fin; -{ - union i6addr dst, src; - register ipstate_t *is, **isp; - register u_char pr; - u_int hv, hvm, hlen, tryagain, pass, v; - struct icmp *ic; - frentry_t *fr; - tcphdr_t *tcp; - - if (fr_state_lock || (fin->fin_off & IP_OFFMASK) || - (fin->fin_fi.fi_fl & FI_SHORT)) - return NULL; - - is = NULL; - hlen = fin->fin_hlen; - tcp = (tcphdr_t *)((char *)ip + hlen); - ic = (struct icmp *)tcp; - hv = (pr = 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; - - /* - * Search the hash table for matching packet header info. - */ - v = fin->fin_fi.fi_v; - switch (fin->fin_fi.fi_p) - { -#ifdef USE_INET6 - case IPPROTO_ICMPV6 : - if (v == 6) { - if (fin->fin_out) - hv -= dst.in4.s_addr; - else - hv -= src.in4.s_addr; - if ((ic->icmp_type == ICMP6_ECHO_REQUEST) || - (ic->icmp_type == ICMP6_ECHO_REPLY)) { - hv += ic->icmp_id; - hv += ic->icmp_seq; - } - } -#endif - case IPPROTO_ICMP : - if (v == 4) { - hv += ic->icmp_id; - hv += ic->icmp_seq; - } - hv %= fr_statesize; - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_hnext) { - if ((is->is_p == pr) && (is->is_v == v) && - fr_matchsrcdst(is, src, dst, fin, NULL) && - fr_matchicmpqueryreply(v, is, ic)) { - is->is_age = fr_icmptimeout; - break; - } - } - if (is != NULL) - break; - RWLOCK_EXIT(&ipf_state); - /* - * No matching icmp state entry. Perhaps this is a - * response to another state entry. - */ -#ifdef USE_INET6 - if (v == 6) - fr = fr_checkicmp6matchingstate((ip6_t *)ip, fin); - else -#endif - fr = fr_checkicmpmatchingstate(ip, fin); - if (fr) - return fr; - break; - case IPPROTO_TCP : - { - register u_short dport, sport; - register int i; - - i = tcp->th_flags; - /* - * Just plain ignore RST flag set with either FIN or SYN. - */ - if ((i & TH_RST) && - ((i & (TH_FIN|TH_SYN|TH_RST)) != TH_RST)) - break; - case IPPROTO_UDP : - dport = tcp->th_dport; - sport = tcp->th_sport; - tryagain = 0; - hv += dport; - hv += sport; - READ_ENTER(&ipf_state); -retry_tcpudp: - hvm = hv % fr_statesize; - for (isp = &ips_table[hvm]; (is = *isp); isp = &is->is_hnext) - if ((is->is_p == pr) && (is->is_v == v) && - fr_matchsrcdst(is, src, dst, fin, tcp)) { - if ((pr == IPPROTO_TCP)) { - if (!fr_tcpstate(is, fin, ip, tcp)) { - continue; - } - } - break; - } - if (is != NULL) { - if (tryagain && - !(is->is_flags & (FI_WILDP|FI_WILDA))) { - hv += dport; - hv += sport; - fr_ipsmove(isp, is, hv); - MUTEX_DOWNGRADE(&ipf_state); - } - break; - } - RWLOCK_EXIT(&ipf_state); - if (!tryagain && ips_wild) { - hv -= dport; - hv -= sport; - tryagain = 1; - WRITE_ENTER(&ipf_state); - goto retry_tcpudp; - } - break; - } - default : - break; - } - if (is == NULL) { - ATOMIC_INCL(ips_stats.iss_miss); - return NULL; - } - MUTEX_ENTER(&is->is_lock); - is->is_bytes += fin->fin_plen; - ips_stats.iss_hits++; - is->is_pkts++; - MUTEX_EXIT(&is->is_lock); - fr = is->is_rule; - fin->fin_fr = fr; - pass = is->is_pass; -#ifndef _KERNEL - if (tcp->th_flags & TCP_CLOSE) - fr_delstate(is); -#endif - RWLOCK_EXIT(&ipf_state); - if (fin->fin_fi.fi_fl & FI_FRAG) - ipfr_newfrag(ip, fin, pass ^ FR_KEEPSTATE); - return fr; -} - - -void ip_statesync(ifp) -void *ifp; -{ - register ipstate_t *is; - - WRITE_ENTER(&ipf_state); - for (is = ips_list; is; is = is->is_next) { - if (is->is_ifpin == ifp) { - is->is_ifpin = GETUNIT(is->is_ifname[0], is->is_v); - if (!is->is_ifpin) - is->is_ifpin = (void *)-1; - } - if (is->is_ifpout == ifp) { - is->is_ifpout = GETUNIT(is->is_ifname[1], is->is_v); - if (!is->is_ifpout) - is->is_ifpout = (void *)-1; - } - } - RWLOCK_EXIT(&ipf_state); -} - - -/* - * Must always be called with fr_ipfstate held as a write lock. - */ -static void fr_delstate(is) -ipstate_t *is; -{ - frentry_t *fr; - - if (is->is_flags & (FI_WILDP|FI_WILDA)) - ips_wild--; - if (is->is_next) - is->is_next->is_pnext = is->is_pnext; - *is->is_pnext = is->is_next; - if (is->is_hnext) - is->is_hnext->is_phnext = is->is_phnext; - *is->is_phnext = is->is_hnext; - if (ips_table[is->is_hv] == NULL) - ips_stats.iss_inuse--; - - fr = is->is_rule; - if (fr != NULL) { - fr->fr_ref--; - if (fr->fr_ref == 0) { - KFREE(fr); - } - } -#ifdef _KERNEL - MUTEX_DESTROY(&is->is_lock); -#endif - KFREE(is); - ips_num--; -} - - -/* - * Free memory in use by all state info. kept. - */ -void fr_stateunload() -{ - register ipstate_t *is; - - WRITE_ENTER(&ipf_state); - while ((is = ips_list)) - fr_delstate(is); - ips_stats.iss_inuse = 0; - ips_num = 0; - RWLOCK_EXIT(&ipf_state); - KFREES(ips_table, fr_statesize * sizeof(ipstate_t *)); - ips_table = NULL; -} - - -/* - * Slowly expire held state for thingslike UDP and ICMP. Timeouts are set - * in expectation of this being called twice per second. - */ -void fr_timeoutstate() -{ - register ipstate_t *is, **isp; -#if defined(_KERNEL) && !SOLARIS - int s; -#endif - - SPL_NET(s); - WRITE_ENTER(&ipf_state); - for (isp = &ips_list; (is = *isp); ) - if (is->is_age && !--is->is_age) { - if (is->is_p == IPPROTO_TCP) - ips_stats.iss_fin++; - else - ips_stats.iss_expire++; -#ifdef IPFILTER_LOG - ipstate_log(is, ISL_EXPIRE); -#endif - fr_delstate(is); - } else - isp = &is->is_next; - if (fr_state_doflush) { - (void) fr_state_flush(1); - fr_state_doflush = 0; - } - RWLOCK_EXIT(&ipf_state); - SPL_X(s); -} - - -/* - * Original idea freom Pradeep Krishnan for use primarily with NAT code. - * (pkrishna@netcom.com) - * - * 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. - * - * 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_tcp_age(age, state, fin, dir) -u_long *age; -u_char *state; -fr_info_t *fin; -int dir; -{ - tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp; - u_char flags = tcp->th_flags; - int dlen, ostate; - - ostate = state[1 - dir]; - - dlen = fin->fin_plen - fin->fin_hlen - (tcp->th_off << 2); - - if (flags & TH_RST) { - if (!(tcp->th_flags & TH_PUSH) && !dlen) { - *age = fr_tcpclosed; - state[dir] = TCPS_CLOSED; - } else { - *age = fr_tcpclosewait; - state[dir] = TCPS_CLOSE_WAIT; - } - return; - } - - *age = fr_tcptimeout; /* default 4 mins */ - - switch(state[dir]) - { - case TCPS_CLOSED: /* 0 */ - if ((flags & TH_OPENING) == TH_OPENING) { - /* - * 'dir' received an S and sends SA in response, - * CLOSED -> SYN_RECEIVED - */ - state[dir] = TCPS_SYN_RECEIVED; - *age = fr_tcptimeout; - } else if ((flags & (TH_SYN|TH_ACK)) == TH_SYN) { - /* 'dir' sent S, CLOSED -> SYN_SENT */ - state[dir] = TCPS_SYN_SENT; - *age = fr_tcptimeout; - } - /* - * 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 & (TH_FIN|TH_SYN|TH_RST|TH_ACK)) == TH_ACK) { - /* we saw an A, guess 'dir' is in ESTABLISHED mode */ - state[dir] = TCPS_ESTABLISHED; - *age = fr_tcpidletimeout; - } - /* - * 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 TCPS_LISTEN: /* 1 */ - /* NOT USED */ - break; - - case TCPS_SYN_SENT: /* 2 */ - if ((flags & (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 - */ - state[dir] = TCPS_ESTABLISHED; - *age = fr_tcpidletimeout; - } else if (flags & 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 - */ - state[dir] = TCPS_FIN_WAIT_1; - *age = fr_tcpidletimeout; /* or fr_tcptimeout? */ - } else if ((flags & 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 - */ - state[dir] = TCPS_SYN_RECEIVED; - *age = fr_tcptimeout; - } - break; - - case TCPS_SYN_RECEIVED: /* 3 */ - if ((flags & (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 - */ - state[dir] = TCPS_ESTABLISHED; - *age = fr_tcpidletimeout; - } else if (flags & 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 - */ - state[dir] = TCPS_FIN_WAIT_1; - *age = fr_tcpidletimeout; - } - break; - - case TCPS_ESTABLISHED: /* 4 */ - if (flags & TH_FIN) { - /* - * 'dir' closed its side of the connection; this - * gives us a half-closed connection; - * ESTABLISHED -> FIN_WAIT_1 - */ - state[dir] = TCPS_FIN_WAIT_1; - *age = fr_tcphalfclosed; - } else if (flags & TH_ACK) { - /* an ACK, should we exclude other flags here? */ - if (ostate == 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 - */ - state[dir] = TCPS_CLOSE_WAIT; - *age = fr_tcphalfclosed; - } else if (ostate < TCPS_CLOSE_WAIT) - /* - * Still a fully established connection, - * reset timeout - */ - *age = fr_tcpidletimeout; - } - break; - - case TCPS_CLOSE_WAIT: /* 5 */ - if (flags & TH_FIN) { - /* - * Application closed and 'dir' sent a FIN, we're now - * going into LAST_ACK state - */ - *age = fr_tcplastack; - state[dir] = 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 - */ - *age = fr_tcphalfclosed; - } - break; - - case TCPS_FIN_WAIT_1: /* 6 */ - if ((flags & TH_ACK) && ostate > 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? - */ - state[dir] = TCPS_TIME_WAIT; - *age = fr_tcptimeout; - } 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 - */ - *age = fr_tcphalfclosed; - break; - - case TCPS_CLOSING: /* 7 */ - /* NOT USED */ - break; - - case TCPS_LAST_ACK: /* 8 */ - if (flags & TH_ACK) { - if ((flags & TH_PUSH) || dlen) - /* - * There is still data to be delivered, reset - * timeout - */ - *age = fr_tcplastack; - } - /* - * 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 TCPS_FIN_WAIT_2: /* 9 */ - /* NOT USED */ - break; - - case TCPS_TIME_WAIT: /* 10 */ - /* we're in 2MSL timeout now */ - break; - } -} - - -#ifdef IPFILTER_LOG -void ipstate_log(is, type) -struct ipstate *is; -u_int type; -{ - struct ipslog ipsl; - void *items[1]; - size_t sizes[1]; - int types[1]; - - ipsl.isl_type = type; - ipsl.isl_pkts = is->is_pkts; - ipsl.isl_bytes = is->is_bytes; - ipsl.isl_src = is->is_src; - ipsl.isl_dst = is->is_dst; - ipsl.isl_p = is->is_p; - ipsl.isl_v = is->is_v; - ipsl.isl_flags = is->is_flags; - if (ipsl.isl_p == IPPROTO_TCP || ipsl.isl_p == IPPROTO_UDP) { - ipsl.isl_sport = is->is_sport; - ipsl.isl_dport = is->is_dport; - if (ipsl.isl_p == IPPROTO_TCP) { - ipsl.isl_state[0] = is->is_state[0]; - ipsl.isl_state[1] = is->is_state[1]; - } - } else if (ipsl.isl_p == IPPROTO_ICMP) - ipsl.isl_itype = is->is_icmp.ics_type; - else { - ipsl.isl_ps.isl_filler[0] = 0; - ipsl.isl_ps.isl_filler[1] = 0; - } - items[0] = &ipsl; - sizes[0] = sizeof(ipsl); - types[0] = 0; - - (void) ipllog(IPL_LOGSTATE, NULL, items, sizes, types, 1); -} -#endif - - -#ifdef USE_INET6 -frentry_t *fr_checkicmp6matchingstate(ip, fin) -ip6_t *ip; -fr_info_t *fin; -{ - register ipstate_t *is, **isp; - register u_short sport, dport; - register u_char pr; - struct icmp6_hdr *ic, *oic; - union i6addr dst, src; - u_short savelen; - fr_info_t ofin; - tcphdr_t *tcp; - frentry_t *fr; - ip6_t *oip; - int type; - 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; - ic = (struct icmp6_hdr *)fin->fin_dp; - type = ic->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; - - oip = (ip6_t *)((char *)ic + ICMPERR_ICMPHLEN); - if (fin->fin_plen < sizeof(*oip)) - return NULL; - - if (oip->ip6_nxt == IPPROTO_ICMPV6) { - oic = (struct icmp6_hdr *)(oip + 1); - /* - * a 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 = oip->ip6_nxt); - src.in6 = oip->ip6_src; - hv += src.in4.s_addr; - dst.in6 = oip->ip6_dst; - hv += dst.in4.s_addr; - hv += oic->icmp6_id; - hv += oic->icmp6_seq; - hv %= fr_statesize; - - oip->ip6_plen = ntohs(oip->ip6_plen); - ofin.fin_v = 6; - fr_makefrip(sizeof(*oip), (ip_t *)oip, &ofin); - oip->ip6_plen = htons(oip->ip6_plen); - ofin.fin_ifp = fin->fin_ifp; - ofin.fin_out = !fin->fin_out; - ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ - - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_hnext) - if ((is->is_p == pr) && - (oic->icmp6_id == is->is_icmp.ics_id) && - (oic->icmp6_seq == is->is_icmp.ics_seq) && - fr_matchsrcdst(is, src, dst, &ofin, NULL)) { - /* - * in the state table ICMP query's are stored - * with the type of the corresponding ICMP - * response. Correct here - */ - if (((is->is_type == ICMP6_ECHO_REPLY) && - (oic->icmp6_type == ICMP6_ECHO_REQUEST)) || - (is->is_type - 1 == oic->icmp6_type )) { - ips_stats.iss_hits++; - is->is_pkts++; - is->is_bytes += fin->fin_plen; - return is->is_rule; - } - } - RWLOCK_EXIT(&ipf_state); - - return NULL; - }; - - if ((oip->ip6_nxt != IPPROTO_TCP) && (oip->ip6_nxt != IPPROTO_UDP)) - return NULL; - tcp = (tcphdr_t *)(oip + 1); - dport = tcp->th_dport; - sport = tcp->th_sport; - - hv = (pr = oip->ip6_nxt); - src.in6 = oip->ip6_src; - hv += src.in4.s_addr; - dst.in6 = oip->ip6_dst; - hv += dst.in4.s_addr; - hv += dport; - hv += sport; - hv %= fr_statesize; - /* - * we make an fin entry to be able to feed it to - * matchsrcdst note that not all fields are encessary - * but this is the cleanest way. Note further we fill - * in fin_mp such that if someone uses it we'll get - * a kernel panic. fr_matchsrcdst does not use this. - * - * watch out here, as ip is in host order and oip in network - * order. Any change we make must be undone afterwards. - */ - savelen = oip->ip6_plen; - oip->ip6_plen = ip->ip6_plen - sizeof(*ip) - ICMPERR_ICMPHLEN; - ofin.fin_v = 6; - fr_makefrip(sizeof(*oip), (ip_t *)oip, &ofin); - oip->ip6_plen = savelen; - ofin.fin_ifp = fin->fin_ifp; - ofin.fin_out = !fin->fin_out; - ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_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) && - fr_matchsrcdst(is, src, dst, &ofin, tcp)) { - fr = is->is_rule; - ips_stats.iss_hits++; - /* - * we must swap src and dst here because the icmp - * comes the other way around - */ - is->is_pkts++; - is->is_bytes += fin->fin_plen; - /* - * we deliberately do not touch the timeouts - * for the accompanying state table entry. - * It remains to be seen if that is correct. XXX - */ - RWLOCK_EXIT(&ipf_state); - return fr; - } - } - RWLOCK_EXIT(&ipf_state); - return NULL; -} -#endif |