diff options
Diffstat (limited to 'sys/contrib/ipfilter/netinet/ip_state.c')
| -rw-r--r-- | sys/contrib/ipfilter/netinet/ip_state.c | 1520 |
1 files changed, 1193 insertions, 327 deletions
diff --git a/sys/contrib/ipfilter/netinet/ip_state.c b/sys/contrib/ipfilter/netinet/ip_state.c index 89a2c3b..c9a28af 100644 --- a/sys/contrib/ipfilter/netinet/ip_state.c +++ b/sys/contrib/ipfilter/netinet/ip_state.c @@ -1,16 +1,29 @@ /* - * Copyright (C) 1995-1997 by Darren Reed. + * 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) 1993-1995 Darren Reed"; -static const char rcsid[] = "@(#)$Id: ip_state.c,v 2.0.2.24.2.14 1998/05/24 03:53:04 darrenr Exp $"; +static const char sccsid[] = "@(#)ip_state.c 1.8 6/5/96 (C) 1993-2000 Darren Reed"; +static const char rcsid[] = "@(#)$Id: ip_state.c,v 2.30.2.9 2000/05/22 10:26:15 darrenr Exp $"; #endif +#include <sys/errno.h> +#include <sys/types.h> +#include <sys/param.h> +#include <sys/file.h> +#if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ + defined(_KERNEL) +# include "opt_ipfilter_log.h" +#endif +#if defined(_KERNEL) && defined(__FreeBSD_version) && \ + (__FreeBSD_version >= 400000) && !defined(KLD_MODULE) +#include "opt_inet6.h" +#endif #if !defined(_KERNEL) && !defined(KERNEL) && !defined(__KERNEL__) +# include <stdio.h> # include <stdlib.h> # include <string.h> #else @@ -19,23 +32,22 @@ static const char rcsid[] = "@(#)$Id: ip_state.c,v 2.0.2.24.2.14 1998/05/24 03:5 # include <linux/module.h> # endif #endif -#include <sys/errno.h> -#include <sys/types.h> -#include <sys/param.h> -#include <sys/file.h> -#if defined(KERNEL) && (__FreeBSD_version >= 220000) +#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> +# include <sys/protosw.h> #endif #include <sys/socket.h> -#if defined(_KERNEL) && !defined(linux) +#if (defined(_KERNEL) || defined(KERNEL)) && !defined(linux) # include <sys/systm.h> #endif #if !defined(__SVR4) && !defined(__svr4__) @@ -45,14 +57,16 @@ static const char rcsid[] = "@(#)$Id: ip_state.c,v 2.0.2.24.2.14 1998/05/24 03:5 #else # include <sys/filio.h> # include <sys/byteorder.h> -# include <sys/dditypes.h> +# ifdef _KERNEL +# include <sys/dditypes.h> +# endif # include <sys/stream.h> # include <sys/kmem.h> #endif #include <net/if.h> #ifdef sun -#include <net/af.h> +# include <net/af.h> #endif #include <net/route.h> #include <netinet/in.h> @@ -72,40 +86,92 @@ static const char rcsid[] = "@(#)$Id: ip_state.c,v 2.0.2.24.2.14 1998/05/24 03:5 #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)) +# define MIN(a,b) (((a)<(b))?(a):(b)) #endif #define TCP_CLOSE (TH_FIN|TH_RST) -ipstate_t *ips_table[IPSTATE_SIZE]; -int ips_num = 0; -ips_stat_t ips_stats; +static ipstate_t **ips_table = NULL; +static ipstate_t *ips_list = NULL; +static int ips_num = 0; +static ips_stat_t ips_stats; #if (SOLARIS || defined(__sgi)) && defined(_KERNEL) -extern kmutex_t ipf_state; +extern KRWLOCK_T ipf_state, ipf_mutex; +extern kmutex_t ipf_rw; #endif -static int fr_matchsrcdst __P((ipstate_t *, struct in_addr, struct in_addr, - fr_info_t *, void *, u_short, u_short)); +#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)); +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 = 60, - fr_tcplastack = 20, - fr_tcptimeout = 120, + fr_tcpclosewait = 2 * TCP_MSL, + fr_tcplastack = 2 * TCP_MSL, + fr_tcptimeout = 2 * TCP_MSL, fr_tcpclosed = 1, - fr_udptimeout = 120, + 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; } @@ -119,7 +185,6 @@ static ips_stat_t *fr_statetstats() static int fr_state_flush(which) int which; { - register int i; register ipstate_t *is, **isp; #if defined(_KERNEL) && !SOLARIS int s; @@ -127,47 +192,69 @@ int which; int delete, removed = 0; SPL_NET(s); - MUTEX_ENTER(&ipf_state); - for (i = 0; i < IPSTATE_SIZE; i++) - for (isp = &ips_table[i]; (is = *isp); ) { - delete = 0; - - switch (which) - { - case 0 : - delete = 1; - break; - case 1 : - if ((is->is_p == IPPROTO_TCP) && - (((is->is_state[0] <= TCPS_ESTABLISHED) && - (is->is_state[1] > TCPS_ESTABLISHED)) || - ((is->is_state[1] <= TCPS_ESTABLISHED) && - (is->is_state[0] > TCPS_ESTABLISHED)))) - delete = 1; + 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) { - *isp = is->is_next; - if (is->is_p == IPPROTO_TCP) - ips_stats.iss_fin++; - else - ips_stats.iss_expire++; + 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); + ipstate_log(is, ISL_FLUSH); #endif - KFREE(is); - ips_num--; - removed++; - } else - isp = &is->is_next; - } - MUTEX_EXIT(&ipf_state); + 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(&sp->is_src, &st.is_src, sizeof(st.is_src)) && + !bcmp(&sp->is_dst, &st.is_src, sizeof(st.is_dst)) && + !bcmp(&sp->is_ps, &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__) @@ -177,175 +264,412 @@ int cmd; #endif int mode; { - int arg, ret, error = 0; + int arg, ret, error = 0; switch (cmd) { + case SIOCDELST : + error = fr_state_remove(data); + break; case SIOCIPFFL : - IRCOPY(data, (caddr_t)&arg, sizeof(arg)); + 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); - IWCOPY((caddr_t)&ret, data, sizeof(ret)); + RWLOCK_EXIT(&ipf_state); + error = IWCOPY((caddr_t)&ret, data, sizeof(ret)); } else error = EINVAL; break; - case SIOCGIPST : - IWCOPY((caddr_t)fr_statetstats(), data, sizeof(ips_stat_t)); +#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 - IWCOPY((caddr_t)&iplused[IPL_LOGSTATE], (caddr_t)data, - sizeof(iplused[IPL_LOGSTATE])); + error = IWCOPY((caddr_t)&iplused[IPL_LOGSTATE], (caddr_t)data, + sizeof(iplused[IPL_LOGSTATE])); #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 : - return EINVAL; + 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) + return EFAULT; + return 0; +} + + +int fr_stputent(data) +caddr_t data; +{ + register ipstate_t *is, *isn; + ipstate_save_t ips, *ipsp; + frentry_t *fr; + 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; + + 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)); + isn->is_rule = fr; + ips.ips_is.is_rule = fr; + 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; +} + + /* * Create a new ipstate structure and hang it off the hash table. */ -int fr_addstate(ip, fin, pass) +ipstate_t *fr_addstate(ip, fin, flags) ip_t *ip; fr_info_t *fin; -u_int pass; +u_int flags; { - ipstate_t ips; - register ipstate_t *is = &ips; + register tcphdr_t *tcp = NULL; + register ipstate_t *is; register u_int hv; + ipstate_t ips; + u_int pass; + int out; - if ((ip->ip_off & 0x1fff) || (fin->fin_fi.fi_fl & FI_SHORT)) - return -1; - if (ips_num == IPSTATE_MAX) { + 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++; - return -1; + 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 = ip->ip_p); - hv += (is->is_src.s_addr = ip->ip_src.s_addr); - hv += (is->is_dst.s_addr = ip->ip_dst.s_addr); + 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 (ip->ip_p) + 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) { - case ICMP_ECHO : - is->is_icmp.ics_type = ICMP_ECHOREPLY; /* XXX */ +#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; + break; +#endif + case ICMP_ECHO : case ICMP_TSTAMP : case ICMP_IREQ : case ICMP_MASKREQ : - is->is_icmp.ics_type = ic->icmp_type + 1; + 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 -1; + return NULL; } - ips_stats.iss_icmp++; + ATOMIC_INCL(ips_stats.iss_icmp); is->is_age = fr_icmptimeout; break; } case IPPROTO_TCP : { - register tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp; + 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. */ - hv += (is->is_dport = tcp->th_dport); - hv += (is->is_sport = tcp->th_sport); - is->is_seq = ntohl(tcp->th_seq); - is->is_ack = ntohl(tcp->th_ack); - is->is_swin = ntohs(tcp->th_win); - is->is_dwin = is->is_swin; /* start them the same */ - ips_stats.iss_tcp++; + 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) + ip->ip_len - + fin->fin_hlen - (tcp->th_off << 2) + + ((tcp->th_flags & TH_SYN) ? 1 : 0) + + ((tcp->th_flags & TH_FIN) ? 1 : 0); + is->is_maxsend = is->is_send; + 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. */ - if ((tcp->th_flags & (TH_SYN|TH_ACK)) == TH_SYN) - is->is_ack = 0; /* Trumpet WinSock 'ism */ - fr_tcp_age(&is->is_age, is->is_state, ip, fin, - tcp->th_sport == is->is_sport); + ATOMIC_INCL(ips_stats.iss_tcp); break; } case IPPROTO_UDP : { - register tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp; + tcp = (tcphdr_t *)fin->fin_dp; - hv += (is->is_dport = tcp->th_dport); - hv += (is->is_sport = tcp->th_sport); - ips_stats.iss_udp++; + 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 -1; + return NULL; } - KMALLOC(is, ipstate_t *, sizeof(*is)); + KMALLOC(is, ipstate_t *); if (is == NULL) { - ips_stats.iss_nomem++; - return -1; + ATOMIC_INCL(ips_stats.iss_nomem); + return NULL; } bcopy((char *)&ips, (char *)is, sizeof(*is)); - hv %= IPSTATE_SIZE; - MUTEX_ENTER(&ipf_state); + 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 = ip->ip_len; - /* - * Copy these from the rule itself. - */ - is->is_opt = fin->fin_fr->fr_ip.fi_optmsk; - is->is_optmsk = fin->fin_fr->fr_mip.fi_optmsk; - is->is_sec = fin->fin_fr->fr_ip.fi_secmsk; - is->is_secmsk = fin->fin_fr->fr_mip.fi_secmsk; - is->is_auth = fin->fin_fr->fr_ip.fi_auth; - is->is_authmsk = fin->fin_fr->fr_mip.fi_auth; - is->is_flags = fin->fin_fr->fr_ip.fi_fl; - is->is_flags |= fin->fin_fr->fr_mip.fi_fl << 4; + is->is_bytes = fin->fin_dlen + fin->fin_hlen; /* - * add into table. + * 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_next = ips_table[hv]; - ips_table[hv] = is; - if (fin->fin_out) { - is->is_ifpin = NULL; - is->is_ifpout = fin->fin_ifp; - } else { - is->is_ifpin = fin->fin_ifp; - is->is_ifpout = NULL; - } + 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); + 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); ips_num++; + if (is->is_p == IPPROTO_TCP) { + MUTEX_ENTER(&is->is_lock); + fr_tcp_age(&is->is_age, is->is_state, fin, + tcp->th_sport == is->is_sport); + MUTEX_EXIT(&is->is_lock); + } #ifdef IPFILTER_LOG ipstate_log(is, ISL_NEW); #endif - MUTEX_EXIT(&ipf_state); + 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 0; + 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 @@ -357,263 +681,633 @@ fr_info_t *fin; ip_t *ip; tcphdr_t *tcp; { - register int seqskew, ackskew; - register u_short swin, dwin; - register tcp_seq seq, ack; + 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); - source = (ip->ip_src.s_addr == is->is_src.s_addr); - - if (!(tcp->th_flags & TH_ACK)) /* Pretend an ack was sent */ - ack = source ? is->is_ack : is->is_seq; + 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); - if (source) { - if (!is->is_seq) - /* - * Must be an outgoing SYN-ACK in reply to a SYN. - */ - is->is_seq = seq; - seqskew = seq - is->is_seq; - ackskew = ack - is->is_ack; - } else { - if (!is->is_ack) - /* - * Must be a SYN-ACK in reply to a SYN. - */ - is->is_ack = seq; - ackskew = seq - is->is_ack; - seqskew = ack - is->is_seq; + 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; } - /* - * Make skew values absolute - */ - if (seqskew < 0) - seqskew = -seqskew; - if (ackskew < 0) - ackskew = -ackskew; - - /* - * If the difference in sequence and ack numbers is within the - * window size of the connection, store these values and match - * the packet. - */ - if (source) { - swin = is->is_swin; - dwin = is->is_dwin; - } else { - dwin = is->is_swin; - swin = is->is_dwin; + 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 ((seqskew <= dwin) && (ackskew <= swin)) { - if (source) { - is->is_seq = seq; - is->is_ack = ack; - is->is_swin = ntohs(tcp->th_win); - } else { - is->is_seq = ack; - is->is_ack = seq; - is->is_dwin = ntohs(tcp->th_win); + 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++; } - ips_stats.iss_hits++; + + ATOMIC_INCL(ips_stats.iss_hits); is->is_pkts++; - is->is_bytes += ip->ip_len; + is->is_bytes += fin->fin_dlen + fin->fin_hlen; /* * Nearing end of connection, start timeout. */ - fr_tcp_age(&is->is_age, is->is_state, ip, fin, source); - return 1; + MUTEX_ENTER(&is->is_lock); + fr_tcp_age(&is->is_age, is->is_state, fin, source); + MUTEX_EXIT(&is->is_lock); + ret = 1; } - return 0; + return ret; } -static int fr_matchsrcdst(is, src, dst, fin, tcp, sp, dp) +static int fr_matchsrcdst(is, src, dst, fin, tcp) ipstate_t *is; -struct in_addr src, dst; +union i6addr src, dst; fr_info_t *fin; -void *tcp; -u_short sp, dp; +tcphdr_t *tcp; { - int ret = 0, rev, out; + int ret = 0, rev, out, flags; + u_short sp, dp; void *ifp; - rev = (is->is_dst.s_addr != dst.s_addr); + rev = fin->fin_rev = IP6NEQ(is->is_dst, dst); ifp = fin->fin_ifp; out = fin->fin_out; - if (!rev) { - if (out) { - if (!is->is_ifpout) - is->is_ifpout = ifp; + 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_ifpin) - is->is_ifpin = ifp; + if (is->is_ifpout == NULL || is->is_ifpout == ifp) + ret = 1; } } else { if (out) { - if (!is->is_ifpin) - is->is_ifpin = ifp; + if (is->is_ifpin == NULL || is->is_ifpin == ifp) + ret = 1; } else { - if (!is->is_ifpout) - is->is_ifpout = ifp; + if (is->is_ifpout == NULL || is->is_ifpout == ifp) + ret = 1; } } - - if (!rev) { - if (((out && is->is_ifpout == ifp) || - (!out && is->is_ifpin == ifp)) && - (is->is_dst.s_addr == dst.s_addr) && - (is->is_src.s_addr == src.s_addr) && - (!tcp || (sp == is->is_sport) && - (dp == is->is_dport))) { + 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 (((out && is->is_ifpin == ifp) || - (!out && is->is_ifpout == ifp)) && - (is->is_dst.s_addr == src.s_addr) && - (is->is_src.s_addr == dst.s_addr) && - (!tcp || (sp == is->is_dport) && - (dp == is->is_sport))) { + 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 (ret) { - if (((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) || - ((fin->fin_fi.fi_fl & (is->is_flags >> 4)) != - (is->is_flags & 0xf))) - ret = 0; + 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); } - return ret; + + 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; + fr_info_t ofin; + tcphdr_t *tcp; + icmphdr_t *icmp; + frentry_t *fr; + ip_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 (((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; + + 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; + + oip->ip_len = ntohs(oip->ip_len); + fr_makefrip(oip->ip_hl << 2, oip, &ofin); + oip->ip_len = htons(oip->ip_len); + ofin.fin_ifp = fin->fin_ifp; + ofin.fin_out = !fin->fin_out; + ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ + + READ_ENTER(&ipf_state); + for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_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 = ip->ip_len - (ip->ip_hl << 2) - ICMPERR_ICMPHLEN; + 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++; + /* + * 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; +} /* * Check if a packet has a registered state. */ -int fr_checkstate(ip, fin) +frentry_t *fr_checkstate(ip, fin) ip_t *ip; fr_info_t *fin; { - register struct in_addr dst, src; + 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; - u_int hv, hlen, pass; - if ((ip->ip_off & 0x1fff) || (fin->fin_fi.fi_fl & FI_SHORT)) - return 0; + 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 = ip->ip_p); - hv += (src.s_addr = ip->ip_src.s_addr); - hv += (dst.s_addr = ip->ip_dst.s_addr); + 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. */ - switch (ip->ip_p) + 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 : - hv += ic->icmp_id; - hv += ic->icmp_seq; - hv %= IPSTATE_SIZE; - MUTEX_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_next) - if ((is->is_p == pr) && - (ic->icmp_id == is->is_icmp.ics_id) && - (ic->icmp_seq == is->is_icmp.ics_seq) && - fr_matchsrcdst(is, src, dst, fin, NULL, 0, 0)) { - if (is->is_icmp.ics_type != ic->icmp_type) - continue; + 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; - is->is_pkts++; - is->is_bytes += ip->ip_len; - ips_stats.iss_hits++; - pass = is->is_pass; - MUTEX_EXIT(&ipf_state); - return pass; + break; } - MUTEX_EXIT(&ipf_state); + } + 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 = tcp->th_dport, sport = tcp->th_sport; - hv += dport; - hv += sport; - hv %= IPSTATE_SIZE; - MUTEX_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_next) - if ((is->is_p == pr) && - fr_matchsrcdst(is, src, dst, fin, tcp, - sport, dport)) { - if (fr_tcpstate(is, fin, ip, tcp)) { - pass = is->is_pass; -#ifdef _KERNEL - MUTEX_EXIT(&ipf_state); -#else + tryagain = 0; +retry_tcp: + hvm = hv % fr_statesize; + WRITE_ENTER(&ipf_state); + for (isp = &ips_table[hvm]; (is = *isp); + isp = &is->is_hnext) - if (tcp->th_flags & TCP_CLOSE) { - *isp = is->is_next; - isp = &ips_table[hv]; - KFREE(is); - } -#endif - return pass; - } + + if ((is->is_p == pr) && (is->is_v == v) && + fr_matchsrcdst(is, src, dst, fin, tcp)) { + if (fr_tcpstate(is, fin, ip, tcp)) + break; + is = NULL; + break; } - MUTEX_EXIT(&ipf_state); + if (is != NULL) + break; + RWLOCK_EXIT(&ipf_state); + hv += dport; + hv += sport; + if (tryagain == 0) { + tryagain = 1; + goto retry_tcp; + } break; } case IPPROTO_UDP : { register u_short dport = tcp->th_dport, sport = tcp->th_sport; - hv += dport; - hv += sport; - hv %= IPSTATE_SIZE; + tryagain = 0; +retry_udp: + hvm = hv % fr_statesize; /* * Nothing else to match on but ports. and IP#'s */ - MUTEX_ENTER(&ipf_state); - for (is = ips_table[hv]; is; is = is->is_next) - if ((is->is_p == pr) && - fr_matchsrcdst(is, src, dst, fin, - tcp, sport, dport)) { - ips_stats.iss_hits++; - is->is_pkts++; - is->is_bytes += ip->ip_len; + READ_ENTER(&ipf_state); + for (is = ips_table[hvm]; is; is = is->is_hnext) + if ((is->is_p == pr) && (is->is_v == v) && + fr_matchsrcdst(is, src, dst, fin, tcp)) { is->is_age = fr_udptimeout; - pass = is->is_pass; - MUTEX_EXIT(&ipf_state); - return pass; + break; } - MUTEX_EXIT(&ipf_state); + if (is != NULL) + break; + RWLOCK_EXIT(&ipf_state); + hv += dport; + hv += sport; + if (tryagain == 0) { + tryagain = 1; + goto retry_udp; + } break; } default : break; } - ips_stats.iss_miss++; - return 0; + 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); +} + + +static void fr_delstate(is) +ipstate_t *is; +{ + frentry_t *fr; + + 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) { + ATOMIC_DEC32(fr->fr_ref); + if (fr->fr_ref == 0) + KFREE(fr); + } +#ifdef _KERNEL + MUTEX_DESTROY(&is->is_lock); +#endif + KFREE(is); + ips_num--; } @@ -622,16 +1316,16 @@ fr_info_t *fin; */ void fr_stateunload() { - register int i; - register ipstate_t *is, **isp; - - MUTEX_ENTER(&ipf_state); - for (i = 0; i < IPSTATE_SIZE; i++) - for (isp = &ips_table[i]; (is = *isp); ) { - *isp = is->is_next; - KFREE(is); - } - MUTEX_EXIT(&ipf_state); + 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; } @@ -641,31 +1335,31 @@ void fr_stateunload() */ void fr_timeoutstate() { - register int i; register ipstate_t *is, **isp; #if defined(_KERNEL) && !SOLARIS int s; #endif SPL_NET(s); - MUTEX_ENTER(&ipf_state); - for (i = 0; i < IPSTATE_SIZE; i++) - for (isp = &ips_table[i]; (is = *isp); ) - if (is->is_age && !--is->is_age) { - *isp = is->is_next; - if (is->is_p == IPPROTO_TCP) - ips_stats.iss_fin++; - else - ips_stats.iss_expire++; + 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); + ipstate_log(is, ISL_EXPIRE); #endif - KFREE(is); - ips_num--; - } else - isp = &is->is_next; - MUTEX_EXIT(&ipf_state); + fr_delstate(is); + } else + isp = &is->is_next; + RWLOCK_EXIT(&ipf_state); SPL_X(s); + if (fr_state_doflush) { + (void) fr_state_flush(1); + fr_state_doflush = 0; + } } @@ -673,10 +1367,9 @@ void fr_timeoutstate() * Original idea freom Pradeep Krishnan for use primarily with NAT code. * (pkrishna@netcom.com) */ -void fr_tcp_age(age, state, ip, fin, dir) +void fr_tcp_age(age, state, fin, dir) u_long *age; u_char *state; -ip_t *ip; fr_info_t *fin; int dir; { @@ -686,7 +1379,7 @@ int dir; ostate = state[1 - dir]; - dlen = ip->ip_len - fin->fin_hlen - (tcp->th_off << 2); + dlen = fin->fin_plen - fin->fin_hlen - (tcp->th_off << 2); if (flags & TH_RST) { if (!(tcp->th_flags & TH_PUSH) && !dlen) { @@ -703,23 +1396,29 @@ int dir; switch(state[dir]) { - case TCPS_FIN_WAIT_2: case TCPS_CLOSED: + if ((flags & (TH_FIN|TH_SYN|TH_RST|TH_ACK)) == TH_ACK) { + state[dir] = TCPS_ESTABLISHED; + *age = fr_tcpidletimeout; + } + case TCPS_FIN_WAIT_2: if ((flags & TH_OPENING) == TH_OPENING) state[dir] = TCPS_SYN_RECEIVED; else if (flags & TH_SYN) state[dir] = TCPS_SYN_SENT; break; case TCPS_SYN_RECEIVED: - if ((flags & (TH_FIN|TH_ACK)) == TH_ACK) { - state[dir] = TCPS_ESTABLISHED; - *age = fr_tcpidletimeout; - } - break; case TCPS_SYN_SENT: if ((flags & (TH_FIN|TH_ACK)) == TH_ACK) { state[dir] = TCPS_ESTABLISHED; *age = fr_tcpidletimeout; + } else if ((flags & (TH_FIN|TH_ACK)) == (TH_FIN|TH_ACK)) { + state[dir] = TCPS_CLOSE_WAIT; + if (!(flags & TH_PUSH) && !dlen && + ostate > TCPS_ESTABLISHED) + *age = fr_tcplastack; + else + *age = fr_tcpclosewait; } break; case TCPS_ESTABLISHED: @@ -730,8 +1429,10 @@ int dir; *age = fr_tcplastack; else *age = fr_tcpclosewait; - } else - *age = fr_tcpidletimeout; + } else { + if (ostate < TCPS_CLOSE_WAIT) + *age = fr_tcpidletimeout; + } break; case TCPS_CLOSE_WAIT: if ((flags & TH_FIN) && !(flags & TH_PUSH) && !dlen && @@ -760,23 +1461,28 @@ int dir; #ifdef IPFILTER_LOG void ipstate_log(is, type) struct ipstate *is; -u_short type; +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; - ipsl.isl_type = type; 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 { @@ -787,6 +1493,166 @@ u_short type; sizes[0] = sizeof(ipsl); types[0] = 0; - (void) ipllog(IPL_LOGSTATE, 0, items, sizes, types, 1); + (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); + 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 |
