diff options
Diffstat (limited to 'sys/contrib/ipfilter/netinet/ip_state.c')
| -rw-r--r-- | sys/contrib/ipfilter/netinet/ip_state.c | 3854 |
1 files changed, 2673 insertions, 1181 deletions
diff --git a/sys/contrib/ipfilter/netinet/ip_state.c b/sys/contrib/ipfilter/netinet/ip_state.c index 87bebfb..7c1b311 100644 --- a/sys/contrib/ipfilter/netinet/ip_state.c +++ b/sys/contrib/ipfilter/netinet/ip_state.c @@ -1,11 +1,15 @@ +/* $FreeBSD$ */ + /* - * Copyright (C) 1995-2002 by Darren Reed. + * Copyright (C) 1995-2003 by Darren Reed. * * See the IPFILTER.LICENCE file for details on licencing. */ - -#if defined(__sgi) && (IRIX > 602) -# include <sys/ptimers.h> +#if defined(KERNEL) || defined(_KERNEL) +# undef KERNEL +# undef _KERNEL +# define KERNEL 1 +# define _KERNEL 1 #endif #include <sys/errno.h> #include <sys/types.h> @@ -19,17 +23,18 @@ (__FreeBSD_version >= 400000) && !defined(KLD_MODULE) #include "opt_inet6.h" #endif -#if !defined(_KERNEL) && !defined(KERNEL) && !defined(__KERNEL__) +#if !defined(_KERNEL) && !defined(__KERNEL__) # include <stdio.h> # include <stdlib.h> # include <string.h> -#else -# ifdef linux -# include <linux/kernel.h> -# include <linux/module.h> +# define _KERNEL +# ifdef __OpenBSD__ +struct file; # endif +# include <sys/uio.h> +# undef _KERNEL #endif -#if (defined(KERNEL) || defined(_KERNEL)) && (__FreeBSD_version >= 220000) +#if defined(_KERNEL) && (__FreeBSD_version >= 220000) # include <sys/filio.h> # include <sys/fcntl.h> # if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM) @@ -39,18 +44,17 @@ # include <sys/ioctl.h> #endif #include <sys/time.h> -#ifndef linux +#if !defined(linux) # include <sys/protosw.h> #endif #include <sys/socket.h> -#if (defined(_KERNEL) || defined(KERNEL)) && !defined(linux) +#if defined(_KERNEL) # include <sys/systm.h> -#endif -#if !defined(__SVR4) && !defined(__svr4__) -# ifndef linux +# if !defined(__SVR4) && !defined(__svr4__) # include <sys/mbuf.h> # endif -#else +#endif +#if defined(__SVR4) || defined(__svr4__) # include <sys/filio.h> # include <sys/byteorder.h> # ifdef _KERNEL @@ -69,8 +73,10 @@ #include <netinet/in_systm.h> #include <netinet/ip.h> #include <netinet/tcp.h> -#ifndef linux +#if !defined(linux) # include <netinet/ip_var.h> +#endif +#if !defined(__hpux) && !defined(linux) # include <netinet/tcp_fsm.h> #endif #include <netinet/udp.h> @@ -81,89 +87,129 @@ #include "netinet/ip_nat.h" #include "netinet/ip_frag.h" #include "netinet/ip_state.h" +#include "netinet/ip_proxy.h" +#ifdef IPFILTER_SYNC +#include "netinet/ip_sync.h" +#endif +#ifdef IPFILTER_SCAN +#include "netinet/ip_scan.h" +#endif #ifdef USE_INET6 #include <netinet/icmp6.h> #endif #if (__FreeBSD_version >= 300000) # include <sys/malloc.h> -# if (defined(_KERNEL) || defined(KERNEL)) && !defined(IPFILTER_LKM) +# if defined(_KERNEL) && !defined(IPFILTER_LKM) # include <sys/libkern.h> # include <sys/systm.h> # endif #endif +/* END OF INCLUDES */ + #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 2.30.2.38 2001/07/23 13:49:46 darrenr Exp $"; */ -static const char rcsid[] = "@(#)$FreeBSD$"; -#endif - -#ifndef MIN -# define MIN(a,b) (((a)<(b))?(a):(b)) +static const char rcsid[] = "@(#)Id: ip_state.c,v 2.186.2.29 2005/03/28 10:47:54 darrenr Exp"; #endif -#define TCP_CLOSE (TH_FIN|TH_RST) - -static ipstate_t **ips_table = NULL; -static int ips_num = 0; -static int ips_wild = 0; -static ips_stat_t ips_stats; -#ifdef USE_MUTEX -extern KRWLOCK_T ipf_state, ipf_mutex; -extern kmutex_t ipf_rw; -#endif +static ipstate_t **ips_table = NULL; +static u_long *ips_seed = NULL; +static int ips_num = 0; +static u_long ips_last_force_flush = 0; +ips_stat_t ips_stats; #ifdef USE_INET6 -static frentry_t *fr_checkicmp6matchingstate __P((ip6_t *, fr_info_t *)); +static ipstate_t *fr_checkicmp6matchingstate __P((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 *, int)); +static ipstate_t *fr_matchsrcdst __P((fr_info_t *, ipstate_t *, i6addr_t *, + i6addr_t *, tcphdr_t *, u_32_t)); +static ipstate_t *fr_checkicmpmatchingstate __P((fr_info_t *)); static int fr_state_flush __P((int, int)); static ips_stat_t *fr_statetstats __P((void)); -static void fr_delstate __P((ipstate_t *)); +static void fr_delstate __P((ipstate_t *, int)); static int fr_state_remove __P((caddr_t)); -static void fr_ipsmove __P((ipstate_t **, ipstate_t *, u_int)); -static int fr_tcpoptions __P((tcphdr_t *)); +static void fr_ipsmove __P((ipstate_t *, u_int)); +static int fr_tcpstate __P((fr_info_t *, tcphdr_t *, ipstate_t *)); +static int fr_tcpoptions __P((fr_info_t *, tcphdr_t *, tcpdata_t *)); +static ipstate_t *fr_stclone __P((fr_info_t *, tcphdr_t *, ipstate_t *)); +static void fr_fixinisn __P((fr_info_t *, ipstate_t *)); +static void fr_fixoutisn __P((fr_info_t *, ipstate_t *)); +static void fr_checknewisn __P((fr_info_t *, ipstate_t *)); + int fr_stputent __P((caddr_t)); int fr_stgetent __P((caddr_t)); -void fr_stinsert __P((ipstate_t *)); +#define ONE_DAY IPF_TTLVAL(1 * 86400) /* 1 day */ +#define FIVE_DAYS (5 * ONE_DAY) +#define DOUBLE_HASH(x) (((x) + ips_seed[(x) % fr_statesize]) % fr_statesize) -#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_udpacktimeout = 24, - fr_icmptimeout = 120, - fr_icmpacktimeout = 12; + fr_tcpclosewait = IPF_TTLVAL(2 * TCP_MSL), + fr_tcplastack = IPF_TTLVAL(2 * TCP_MSL), + fr_tcptimeout = IPF_TTLVAL(2 * TCP_MSL), + fr_tcpclosed = IPF_TTLVAL(60), + fr_tcphalfclosed = IPF_TTLVAL(2 * 3600), /* 2 hours */ + fr_udptimeout = IPF_TTLVAL(120), + fr_udpacktimeout = IPF_TTLVAL(12), + fr_icmptimeout = IPF_TTLVAL(60), + fr_icmpacktimeout = IPF_TTLVAL(6), + fr_iptimeout = IPF_TTLVAL(60); int fr_statemax = IPSTATE_MAX, fr_statesize = IPSTATE_SIZE; int fr_state_doflush = 0, - fr_state_lock = 0; + fr_state_lock = 0, + fr_state_maxbucket = 0, + fr_state_maxbucket_reset = 1, + fr_state_init = 0; +ipftq_t ips_tqtqb[IPF_TCP_NSTATES], + ips_udptq, + ips_udpacktq, + ips_iptq, + ips_icmptq, + ips_icmpacktq, + *ips_utqe = NULL; +#ifdef IPFILTER_LOG +int ipstate_logging = 1; +#else +int ipstate_logging = 0; +#endif ipstate_t *ips_list = NULL; -static int icmpreplytype4[ICMP_MAXTYPE + 1]; -#ifdef USE_INET6 -static int icmpreplytype6[ICMP6_MAXTYPE + 1]; -#endif +/* ------------------------------------------------------------------------ */ +/* Function: fr_stateinit */ +/* Returns: int - 0 == success, -1 == failure */ +/* Parameters: Nil */ +/* */ +/* Initialise all the global variables used within the state code. */ +/* This action also includes initiailising locks. */ +/* ------------------------------------------------------------------------ */ 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 + if (ips_table == NULL) return -1; + bzero((char *)ips_table, fr_statesize * sizeof(ipstate_t *)); + + KMALLOCS(ips_seed, u_long *, fr_statesize * sizeof(*ips_seed)); + if (ips_seed == NULL) + return -2; + for (i = 0; i < fr_statesize; i++) { + /* + * XXX - ips_seed[X] should be a random number of sorts. + */ +#if (__FreeBSD_version >= 400000) + ips_seed[i] = arc4random(); +#else + ips_seed[i] = ((u_long)ips_seed + i) * fr_statesize; + ips_seed[i] ^= 0xa5a55a5a; + ips_seed[i] *= (u_long)ips_seed; + ips_seed[i] ^= 0x5a5aa5a5; + ips_seed[i] *= fr_statemax; +#endif + } /* fill icmp reply type table */ for (i = 0; i <= ICMP_MAXTYPE; i++) @@ -183,111 +229,155 @@ int fr_stateinit() icmpreplytype6[ND_NEIGHBOR_SOLICIT] = ND_NEIGHBOR_ADVERT; #endif + KMALLOCS(ips_stats.iss_bucketlen, u_long *, + fr_statesize * sizeof(u_long)); + if (ips_stats.iss_bucketlen == NULL) + return -1; + bzero((char *)ips_stats.iss_bucketlen, fr_statesize * sizeof(u_long)); + + if (fr_state_maxbucket == 0) { + for (i = fr_statesize; i > 0; i >>= 1) + fr_state_maxbucket++; + fr_state_maxbucket *= 2; + } + + fr_sttab_init(ips_tqtqb); + ips_tqtqb[IPF_TCP_NSTATES - 1].ifq_next = &ips_udptq; + ips_udptq.ifq_ttl = (u_long)fr_udptimeout; + ips_udptq.ifq_ref = 1; + ips_udptq.ifq_head = NULL; + ips_udptq.ifq_tail = &ips_udptq.ifq_head; + MUTEX_INIT(&ips_udptq.ifq_lock, "ipftq udp tab"); + ips_udptq.ifq_next = &ips_udpacktq; + ips_udpacktq.ifq_ttl = (u_long)fr_udpacktimeout; + ips_udpacktq.ifq_ref = 1; + ips_udpacktq.ifq_head = NULL; + ips_udpacktq.ifq_tail = &ips_udpacktq.ifq_head; + MUTEX_INIT(&ips_udpacktq.ifq_lock, "ipftq udpack tab"); + ips_udpacktq.ifq_next = &ips_icmptq; + ips_icmptq.ifq_ttl = (u_long)fr_icmptimeout; + ips_icmptq.ifq_ref = 1; + ips_icmptq.ifq_head = NULL; + ips_icmptq.ifq_tail = &ips_icmptq.ifq_head; + MUTEX_INIT(&ips_icmptq.ifq_lock, "ipftq icmp tab"); + ips_icmptq.ifq_next = &ips_icmpacktq; + ips_icmpacktq.ifq_ttl = (u_long)fr_icmpacktimeout; + ips_icmpacktq.ifq_ref = 1; + ips_icmpacktq.ifq_head = NULL; + ips_icmpacktq.ifq_tail = &ips_icmpacktq.ifq_head; + MUTEX_INIT(&ips_icmpacktq.ifq_lock, "ipftq icmpack tab"); + ips_icmpacktq.ifq_next = &ips_iptq; + ips_iptq.ifq_ttl = (u_long)fr_iptimeout; + ips_iptq.ifq_ref = 1; + ips_iptq.ifq_head = NULL; + ips_iptq.ifq_tail = &ips_iptq.ifq_head; + MUTEX_INIT(&ips_iptq.ifq_lock, "ipftq ip tab"); + ips_iptq.ifq_next = NULL; + + RWLOCK_INIT(&ipf_state, "ipf IP state rwlock"); + MUTEX_INIT(&ipf_stinsert, "ipf state insert mutex"); + fr_state_init = 1; + + ips_last_force_flush = fr_ticks; return 0; } -static ips_stat_t *fr_statetstats() +/* ------------------------------------------------------------------------ */ +/* Function: fr_stateunload */ +/* Returns: Nil */ +/* Parameters: Nil */ +/* */ +/* Release and destroy any resources acquired or initialised so that */ +/* IPFilter can be unloaded or re-initialised. */ +/* ------------------------------------------------------------------------ */ +void fr_stateunload() { - ips_stats.iss_active = ips_num; - ips_stats.iss_table = ips_table; - ips_stats.iss_list = ips_list; - return &ips_stats; -} + ipftq_t *ifq, *ifqnext; + ipstate_t *is; + while ((is = ips_list) != NULL) + fr_delstate(is, 0); -/* - * 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. - * which == 2 : flush TCP connections which have been idle for a long time, - * starting at > 4 days idle and working back in successive half- - * days to at most 12 hours old. - */ -static int fr_state_flush(which, proto) -int which, proto; -{ - ipstate_t *is, **isp; -#if defined(_KERNEL) && !SOLARIS - int s; -#endif - int delete, removed = 0, try; + /* + * Proxy timeout queues are not cleaned here because although they + * exist on the state list, appr_unload is called after fr_stateunload + * and the proxies actually are responsible for them being created. + * Should the proxy timeouts have their own list? There's no real + * justification as this is the only complicationA + */ + for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) { + ifqnext = ifq->ifq_next; + if (((ifq->ifq_flags & IFQF_PROXY) == 0) && + (fr_deletetimeoutqueue(ifq) == 0)) + fr_freetimeoutqueue(ifq); + } - SPL_NET(s); - for (isp = &ips_list; (is = *isp); ) { - delete = 0; + ips_stats.iss_inuse = 0; + ips_num = 0; - if ((proto != 0) && (is->is_v != proto)) - continue; + if (fr_state_init == 1) { + fr_sttab_destroy(ips_tqtqb); + MUTEX_DESTROY(&ips_udptq.ifq_lock); + MUTEX_DESTROY(&ips_icmptq.ifq_lock); + MUTEX_DESTROY(&ips_udpacktq.ifq_lock); + MUTEX_DESTROY(&ips_icmpacktq.ifq_lock); + MUTEX_DESTROY(&ips_iptq.ifq_lock); + } - switch (which) - { - case 0 : - delete = 1; - break; - case 1 : - case 2 : - if (is->is_p != IPPROTO_TCP) - break; - if ((is->is_state[0] != TCPS_ESTABLISHED) || - (is->is_state[1] != TCPS_ESTABLISHED)) - delete = 1; - break; - } + if (ips_table != NULL) { + KFREES(ips_table, fr_statesize * sizeof(*ips_table)); + ips_table = NULL; + } - 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; + if (ips_seed != NULL) { + KFREES(ips_seed, fr_statesize * sizeof(*ips_seed)); + ips_seed = NULL; } - /* - * Asked to remove inactive entries, try again if first attempt - * failed. In this case, 86400 is half a day because the counter is - * activated every half second. - */ - if ((which == 2) && (removed == 0)) { - try = 86400; /* half a day */ - for (; (try < FIVE_DAYS) && (removed == 0); try += 86400) { - for (isp = &ips_list; (is = *isp); ) { - delete = 0; - if ((is->is_p == IPPROTO_TCP) && - ((is->is_state[0] == TCPS_ESTABLISHED) || - (is->is_state[1] == TCPS_ESTABLISHED)) && - (is->is_age < try)) { - ips_stats.iss_fin++; - delete = 1; - } else if ((is->is_p != IPPROTO_TCP) && - (is->is_pkts > 1)) { - ips_stats.iss_expire++; - delete = 1; - } - if (delete) { -#ifdef IPFILTER_LOG - ipstate_log(is, ISL_FLUSH); -#endif - fr_delstate(is); - removed++; - } else - isp = &is->is_next; - } - } + if (ips_stats.iss_bucketlen != NULL) { + KFREES(ips_stats.iss_bucketlen, fr_statesize * sizeof(u_long)); + ips_stats.iss_bucketlen = NULL; } - SPL_X(s); - return removed; + if (fr_state_maxbucket_reset == 1) + fr_state_maxbucket = 0; + + if (fr_state_init == 1) { + fr_state_init = 0; + RW_DESTROY(&ipf_state); + MUTEX_DESTROY(&ipf_stinsert); + } } +/* ------------------------------------------------------------------------ */ +/* Function: fr_statetstats */ +/* Returns: ips_state_t* - pointer to state stats structure */ +/* Parameters: Nil */ +/* */ +/* Put all the current numbers and pointers into a single struct and return */ +/* a pointer to it. */ +/* ------------------------------------------------------------------------ */ +static ips_stat_t *fr_statetstats() +{ + ips_stats.iss_active = ips_num; + ips_stats.iss_statesize = fr_statesize; + ips_stats.iss_statemax = fr_statemax; + ips_stats.iss_table = ips_table; + ips_stats.iss_list = ips_list; + ips_stats.iss_ticks = fr_ticks; + return &ips_stats; +} + +/* ------------------------------------------------------------------------ */ +/* Function: fr_state_remove */ +/* Returns: int - 0 == success, != 0 == failure */ +/* Parameters: data(I) - pointer to state structure to delete from table */ +/* */ +/* Search for a state structure that matches the one passed, according to */ +/* the IP addresses and other protocol specific information. */ +/* ------------------------------------------------------------------------ */ static int fr_state_remove(data) caddr_t data; { @@ -295,23 +385,20 @@ caddr_t data; int error; sp = &st; - error = IRCOPYPTR(data, (caddr_t)&st, sizeof(st)); + error = fr_inobj(data, &st, IPFOBJ_IPSTATE); if (error) return EFAULT; WRITE_ENTER(&ipf_state); 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, + !bcmp((caddr_t)&sp->is_src, (caddr_t)&st.is_src, sizeof(st.is_src)) && - !bcmp((char *)&sp->is_dst, (char *)&st.is_dst, + !bcmp((caddr_t)&sp->is_dst, (caddr_t)&st.is_src, sizeof(st.is_dst)) && - !bcmp((char *)&sp->is_ps, (char *)&st.is_ps, + !bcmp((caddr_t)&sp->is_ps, (caddr_t)&st.is_ps, sizeof(st.is_ps))) { -#ifdef IPFILTER_LOG - ipstate_log(sp, ISL_REMOVE); -#endif - fr_delstate(sp); + fr_delstate(sp, ISL_REMOVE); RWLOCK_EXIT(&ipf_state); return 0; } @@ -320,49 +407,59 @@ caddr_t data; } +/* ------------------------------------------------------------------------ */ +/* Function: fr_state_ioctl */ +/* Returns: int - 0 == success, != 0 == failure */ +/* Parameters: data(I) - pointer to ioctl data */ +/* cmd(I) - ioctl command integer */ +/* mode(I) - file mode bits used with open */ +/* */ +/* Processes an ioctl call made to operate on the IP Filter state device. */ +/* ------------------------------------------------------------------------ */ int fr_state_ioctl(data, cmd, mode) caddr_t data; -#if defined(__NetBSD__) || defined(__OpenBSD__) -u_long cmd; -#else -int cmd; -#endif +ioctlcmd_t cmd; int mode; { int arg, ret, error = 0; switch (cmd) { + /* + * Delete an entry from the state table. + */ case SIOCDELST : error = fr_state_remove(data); break; + /* + * Flush the state table + */ case SIOCIPFFL : - error = IRCOPY(data, (caddr_t)&arg, sizeof(arg)); - if (error) - break; + BCOPYIN(data, (char *)&arg, sizeof(arg)); if (arg == 0 || arg == 1) { WRITE_ENTER(&ipf_state); ret = fr_state_flush(arg, 4); RWLOCK_EXIT(&ipf_state); - error = IWCOPY((caddr_t)&ret, data, sizeof(ret)); + BCOPYOUT((char *)&ret, data, sizeof(ret)); } else error = EINVAL; break; -#ifdef USE_INET6 +#ifdef USE_INET6 case SIOCIPFL6 : - error = IRCOPY(data, (caddr_t)&arg, sizeof(arg)); - if (error) - break; + BCOPYIN(data, (char *)&arg, sizeof(arg)); if (arg == 0 || arg == 1) { WRITE_ENTER(&ipf_state); ret = fr_state_flush(arg, 6); RWLOCK_EXIT(&ipf_state); - error = IWCOPY((caddr_t)&ret, data, sizeof(ret)); + BCOPYOUT((char *)&ret, data, sizeof(ret)); } else error = EINVAL; break; #endif #ifdef IPFILTER_LOG + /* + * Flush the state log. + */ case SIOCIPFFB : if (!(mode & FWRITE)) error = EPERM; @@ -370,23 +467,51 @@ int mode; int tmp; tmp = ipflog_clear(IPL_LOGSTATE); - IWCOPY((char *)&tmp, data, sizeof(tmp)); + BCOPYOUT((char *)&tmp, data, sizeof(tmp)); } break; -#endif - case SIOCGETFS : - error = IWCOPYPTR((caddr_t)fr_statetstats(), data, - sizeof(ips_stat_t)); + /* + * Turn logging of state information on/off. + */ + case SIOCSETLG : + if (!(mode & FWRITE)) + error = EPERM; + else { + BCOPYIN((char *)data, (char *)&ipstate_logging, + sizeof(ipstate_logging)); + } + break; + /* + * Return the current state of logging. + */ + case SIOCGETLG : + BCOPYOUT((char *)&ipstate_logging, (char *)data, + sizeof(ipstate_logging)); break; + /* + * Return the number of bytes currently waiting to be read. + */ case FIONREAD : -#ifdef IPFILTER_LOG - arg = (int)iplused[IPL_LOGSTATE]; - error = IWCOPY((caddr_t)&arg, (caddr_t)data, sizeof(arg)); + arg = iplused[IPL_LOGSTATE]; /* returned in an int */ + BCOPYOUT((char *)&arg, data, sizeof(arg)); + break; #endif + /* + * Get the current state statistics. + */ + case SIOCGETFS : + error = fr_outobj(data, fr_statetstats(), IPFOBJ_STATESTAT); break; + /* + * Lock/Unlock the state table. (Locking prevents any changes, which + * means no packets match). + */ case SIOCSTLCK : - error = fr_lock(data, &fr_state_lock); + fr_lock(data, &fr_state_lock); break; + /* + * Add an entry to the current state table. + */ case SIOCSTPUT : if (!fr_state_lock) { error = EACCES; @@ -394,6 +519,9 @@ int mode; } error = fr_stputent(data); break; + /* + * Get a state table entry. + */ case SIOCSTGET : if (!fr_state_lock) { error = EACCES; @@ -409,22 +537,30 @@ int mode; } -/* - * Copy out state information from the kernel to a user space process. - */ +/* ------------------------------------------------------------------------ */ +/* Function: fr_stgetent */ +/* Returns: int - 0 == success, != 0 == failure */ +/* Parameters: data(I) - pointer to state structure to retrieve from table */ +/* */ +/* Copy out state information from the kernel to a user space process. If */ +/* there is a filter rule associated with the state entry, copy that out */ +/* as well. The entry to copy out is taken from the value of "ips_next" in */ +/* the struct passed in and if not null and not found in the list of current*/ +/* state entries, the retrieval fails. */ +/* ------------------------------------------------------------------------ */ int fr_stgetent(data) caddr_t data; { - register ipstate_t *is, *isn; + ipstate_t *is, *isn; ipstate_save_t ips; int error; - error = IRCOPYPTR(data, (caddr_t)&ips, sizeof(ips)); + error = fr_inobj(data, &ips, IPFOBJ_STATESAVE); if (error) - return error; + return EFAULT; isn = ips.ips_next; - if (!isn) { + if (isn == NULL) { isn = ips_list; if (isn == NULL) { if (ips.ips_next == NULL) @@ -445,171 +581,272 @@ caddr_t data; } ips.ips_next = isn->is_next; bcopy((char *)isn, (char *)&ips.ips_is, sizeof(ips.ips_is)); - if (isn->is_rule) + ips.ips_rule = isn->is_rule; + if (isn->is_rule != NULL) bcopy((char *)isn->is_rule, (char *)&ips.ips_fr, sizeof(ips.ips_fr)); - error = IWCOPYPTR((caddr_t)&ips, data, sizeof(ips)); + error = fr_outobj(data, &ips, IPFOBJ_STATESAVE); if (error) - error = EFAULT; - return error; + return EFAULT; + return 0; } +/* ------------------------------------------------------------------------ */ +/* Function: fr_stputent */ +/* Returns: int - 0 == success, != 0 == failure */ +/* Parameters: data(I) - pointer to state information struct */ +/* */ +/* This function implements the SIOCSTPUT ioctl: insert a state entry into */ +/* the state table. If the state info. includes a pointer to a filter rule */ +/* then also add in an orphaned rule (will not show up in any "ipfstat -io" */ +/* output. */ +/* ------------------------------------------------------------------------ */ int fr_stputent(data) caddr_t data; { - register ipstate_t *is, *isn; + ipstate_t *is, *isn; ipstate_save_t ips; int error, out, i; frentry_t *fr; char *name; - error = IRCOPYPTR(data, (caddr_t)&ips, sizeof(ips)); + error = fr_inobj(data, &ips, IPFOBJ_STATESAVE); if (error) - return 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; + bzero((char *)isn, offsetof(struct ipstate, is_pkts)); + isn->is_sti.tqe_pnext = NULL; + isn->is_sti.tqe_next = NULL; + isn->is_sti.tqe_ifq = NULL; + isn->is_sti.tqe_parent = isn; + isn->is_ifp[0] = NULL; + isn->is_ifp[1] = NULL; + isn->is_ifp[2] = NULL; + isn->is_ifp[3] = NULL; + isn->is_sync = NULL; + fr = ips.ips_rule; + + if (fr == NULL) { + READ_ENTER(&ipf_state); + fr_stinsert(isn, 0); + RWLOCK_EXIT(&ipf_state); + return 0; + } - /* - * Look up all the interface names in the rule. - */ - for (i = 0; i < 4; i++) { - name = fr->fr_ifnames[i]; - if ((name[1] == '\0') && - ((name[0] == '-') || (name[0] == '*'))) { - fr->fr_ifas[i] = NULL; - } else if (*name != '\0') { - fr->fr_ifas[i] = GETUNIT(name, - fr->fr_v); - if (fr->fr_ifas[i] == NULL) - fr->fr_ifas[i] = (void *)-1; - else { - strncpy(isn->is_ifname[i], - IFNAME(fr->fr_ifas[i]), - IFNAMSIZ); - } - } - isn->is_ifp[out] = fr->fr_ifas[i]; - } + if (isn->is_flags & SI_NEWFR) { + KMALLOC(fr, frentry_t *); + if (fr == NULL) { + KFREE(isn); + return ENOMEM; + } + bcopy((char *)&ips.ips_fr, (char *)fr, sizeof(*fr)); + out = fr->fr_flags & FR_OUTQUE ? 1 : 0; + isn->is_rule = fr; + ips.ips_is.is_rule = fr; + MUTEX_NUKE(&fr->fr_lock); + MUTEX_INIT(&fr->fr_lock, "state filter rule lock"); - /* - * send a copy back to userland of what we ended up - * to allow for verification. - */ - error = IWCOPYPTR((caddr_t)&ips, data, 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; + /* + * Look up all the interface names in the rule. + */ + for (i = 0; i < 4; i++) { + name = fr->fr_ifnames[i]; + fr->fr_ifas[i] = fr_resolvenic(name, fr->fr_v); + name = isn->is_ifname[i]; + isn->is_ifp[i] = fr_resolvenic(name, isn->is_v); + } + + fr->fr_ref = 0; + fr->fr_dsize = 0; + fr->fr_data = NULL; + + fr_resolvedest(&fr->fr_tif, fr->fr_v); + fr_resolvedest(&fr->fr_dif, fr->fr_v); + + /* + * send a copy back to userland of what we ended up + * to allow for verification. + */ + error = fr_outobj(data, &ips, IPFOBJ_STATESAVE); + if (error) { + KFREE(isn); + MUTEX_DESTROY(&fr->fr_lock); + KFREE(fr); + return EFAULT; + } + READ_ENTER(&ipf_state); + fr_stinsert(isn, 0); + RWLOCK_EXIT(&ipf_state); + + } else { + READ_ENTER(&ipf_state); + for (is = ips_list; is; is = is->is_next) + if (is->is_rule == fr) { + fr_stinsert(isn, 0); + break; } + + if (is == NULL) { + KFREE(isn); + isn = NULL; } + RWLOCK_EXIT(&ipf_state); + + return (isn == NULL) ? ESRCH : 0; } - fr_stinsert(isn); + return 0; } -/* - * Insert a state table entry manually. - */ -void fr_stinsert(is) -register ipstate_t *is; +/* ------------------------------------------------------------------------ */ +/* Function: fr_stinsert */ +/* Returns: Nil */ +/* Parameters: is(I) - pointer to state structure */ +/* rev(I) - flag indicating forward/reverse direction of packet */ +/* */ +/* Inserts a state structure into the hash table (for lookups) and the list */ +/* of state entries (for enumeration). Resolves all of the interface names */ +/* to pointers and adjusts running stats for the hash table as appropriate. */ +/* */ +/* Locking: it is assumed that some kind of lock on ipf_state is held. */ +/* ------------------------------------------------------------------------ */ +void fr_stinsert(is, rev) +ipstate_t *is; +int rev; { - register u_int hv = is->is_hv; - char *name; + frentry_t *fr; + u_int hv; int i; - MUTEX_INIT(&is->is_lock, "ipf state entry", NULL); + MUTEX_INIT(&is->is_lock, "ipf state entry"); + + fr = is->is_rule; + if (fr != NULL) { + MUTEX_ENTER(&fr->fr_lock); + fr->fr_ref++; + fr->fr_statecnt++; + MUTEX_EXIT(&fr->fr_lock); + } /* * Look up all the interface names in the state entry. */ for (i = 0; i < 4; i++) { - name = is->is_ifname[i]; - if ((name[1] == '\0') && - ((name[0] == '-') || (name[0] == '*'))) { - is->is_ifp[0] = NULL; - } else if (*name != '\0') { - is->is_ifp[i] = GETUNIT(name, is->is_v); - if (is->is_ifp[i] == NULL) - is->is_ifp[i] = (void *)-1; - } + if (is->is_ifp[i] != NULL) + continue; + is->is_ifp[i] = fr_resolvenic(is->is_ifname[i], is->is_v); } + /* + * If we could trust is_hv, then the modulous would not be needed, but + * when running with IPFILTER_SYNC, this stops bad values. + */ + hv = is->is_hv % fr_statesize; + is->is_hv = hv; + + /* + * We need to get both of these locks...the first because it is + * possible that once the insert is complete another packet might + * come along, match the entry and want to update it. + */ + MUTEX_ENTER(&is->is_lock); + MUTEX_ENTER(&ipf_stinsert); /* * add into list table. */ - if (ips_list) + if (ips_list != NULL) ips_list->is_pnext = &is->is_next; is->is_pnext = &ips_list; is->is_next = ips_list; ips_list = is; - if (ips_table[hv]) + + if (ips_table[hv] != NULL) ips_table[hv]->is_phnext = &is->is_hnext; else ips_stats.iss_inuse++; is->is_phnext = ips_table + hv; is->is_hnext = ips_table[hv]; ips_table[hv] = is; + ips_stats.iss_bucketlen[hv]++; ips_num++; + MUTEX_EXIT(&ipf_stinsert); + + fr_setstatequeue(is, rev); + MUTEX_EXIT(&is->is_lock); } -/* - * Create a new ipstate structure and hang it off the hash table. - */ -ipstate_t *fr_addstate(ip, fin, stsave, flags) -ip_t *ip; +/* ------------------------------------------------------------------------ */ +/* Function: fr_addstate */ +/* Returns: ipstate_t* - NULL == failure, else pointer to new state */ +/* Parameters: fin(I) - pointer to packet information */ +/* stsave(O) - pointer to place to save pointer to created */ +/* state structure. */ +/* flags(I) - flags to use when creating the structure */ +/* */ +/* Creates a new IP state structure from the packet information collected. */ +/* Inserts it into the state table and appends to the bottom of the active */ +/* list. If the capacity of the table has reached the maximum allowed then */ +/* the call will fail and a flush is scheduled for the next timeout call. */ +/* ------------------------------------------------------------------------ */ +ipstate_t *fr_addstate(fin, stsave, flags) fr_info_t *fin; ipstate_t **stsave; u_int flags; { - register tcphdr_t *tcp = NULL; - register ipstate_t *is; - register u_int hv; + ipstate_t *is, ips; struct icmp *ic; - ipstate_t ips; - int out, ws; - u_int pass; + u_int pass, hv; + frentry_t *fr; + tcphdr_t *tcp; + grehdr_t *gre; void *ifp; + int out; - if (fr_state_lock || (fin->fin_off != 0) || (fin->fin_fl & FI_SHORT) || - (fin->fin_misc & FM_BADSTATE)) + if (fr_state_lock || + (fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD))) return NULL; - if (ips_num == fr_statemax) { - ips_stats.iss_max++; + + if ((fin->fin_flx & FI_OOW) && !(fin->fin_tcpf & TH_SYN)) + return NULL; + + fr = fin->fin_fr; + if ((fr->fr_statemax == 0) && (ips_num == fr_statemax)) { + ATOMIC_INCL(ips_stats.iss_max); + fr_state_doflush = 1; + return NULL; + } + + /* + * If a "keep state" rule has reached the maximum number of references + * to it, then schedule an automatic flush in case we can clear out + * some "dead old wood". + */ + if ((fr != NULL) && (fr->fr_statemax != 0) && + (fr->fr_statecnt >= fr->fr_statemax)) { + MUTEX_EXIT(&fr->fr_lock); + ATOMIC_INCL(ips_stats.iss_maxref); fr_state_doflush = 1; return NULL; } + + pass = (fr == NULL) ? 0 : fr->fr_flags; + + ic = NULL; + tcp = NULL; out = fin->fin_out; is = &ips; bzero((char *)is, sizeof(*is)); - ips.is_age = 1; + is->is_die = 1 + fr_ticks; + /* * Copy and calculate... */ @@ -620,12 +857,22 @@ u_int flags; hv += is->is_daddr; #ifdef USE_INET6 if (fin->fin_v == 6) { + /* + * For ICMPv6, we check to see if the destination address is + * a multicast address. If it is, do not include it in the + * calculation of the hash because the correct reply will come + * back from a real address, not a multicast address. + */ if ((is->is_p == IPPROTO_ICMPV6) && IN6_IS_ADDR_MULTICAST(&is->is_dst.in6)) { /* * So you can do keep state with neighbour discovery. + * + * Here we could use the address from the neighbour + * solicit message to put in the state structure and + * we could use that without a wildcard flag too... */ - flags |= FI_W_DADDR; + flags |= SI_W_DADDR; hv -= is->is_daddr; } else { hv += is->is_dst.i6[1]; @@ -640,36 +887,30 @@ u_int flags; switch (is->is_p) { - int off; - #ifdef USE_INET6 case IPPROTO_ICMPV6 : - ic = (struct icmp *)fin->fin_dp; - if ((ic->icmp_type & ICMP6_INFOMSG_MASK) == 0) - return NULL; + ic = fin->fin_dp; switch (ic->icmp_type) { case ICMP6_ECHO_REQUEST : - 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); + is->is_icmp.ici_type = ic->icmp_type; + hv += (is->is_icmp.ici_id = ic->icmp_id); break; case ICMP6_MEMBERSHIP_QUERY : case ND_ROUTER_SOLICIT : case ND_NEIGHBOR_SOLICIT : case ICMP6_NI_QUERY : - is->is_icmp.ics_type = ic->icmp_type; + is->is_icmp.ici_type = ic->icmp_type; break; default : return NULL; } ATOMIC_INCL(ips_stats.iss_icmp); - is->is_age = fr_icmptimeout; break; #endif case IPPROTO_ICMP : - ic = (struct icmp *)fin->fin_dp; + ic = fin->fin_dp; switch (ic->icmp_type) { @@ -677,18 +918,28 @@ u_int flags; 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); + is->is_icmp.ici_type = ic->icmp_type; + hv += (is->is_icmp.ici_id = ic->icmp_id); break; default : return NULL; } ATOMIC_INCL(ips_stats.iss_icmp); - is->is_age = fr_icmptimeout; break; + + case IPPROTO_GRE : + gre = fin->fin_dp; + + is->is_gre.gs_flags = gre->gr_flags; + is->is_gre.gs_ptype = gre->gr_ptype; + if (GRE_REV(is->is_gre.gs_flags) == 1) { + is->is_call[0] = fin->fin_data[0]; + is->is_call[1] = fin->fin_data[1]; + } + break; + case IPPROTO_TCP : - tcp = (tcphdr_t *)fin->fin_dp; + tcp = fin->fin_dp; if (tcp->th_flags & TH_RST) return NULL; @@ -698,32 +949,55 @@ u_int flags; */ is->is_sport = htons(fin->fin_data[0]); is->is_dport = htons(fin->fin_data[1]); - if ((flags & (FI_W_DPORT|FI_W_SPORT)) == 0) { + if ((flags & (SI_W_DPORT|SI_W_SPORT)) == 0) { hv += is->is_sport; hv += is->is_dport; } - if ((flags & FI_IGNOREPKT) == 0) { + + /* + * If this is a real packet then initialise fields in the + * state information structure from the TCP header information. + */ + + is->is_maxdwin = 1; + is->is_maxswin = ntohs(tcp->th_win); + if (is->is_maxswin == 0) + is->is_maxswin = 1; + + if ((fin->fin_flx & FI_IGNORE) == 0) { is->is_send = ntohl(tcp->th_seq) + fin->fin_dlen - - (off = (tcp->th_off << 2)) + + (TCP_OFF(tcp) << 2) + ((tcp->th_flags & TH_SYN) ? 1 : 0) + ((tcp->th_flags & TH_FIN) ? 1 : 0); is->is_maxsend = is->is_send; - if ((tcp->th_flags & TH_SYN) && - ((tcp->th_off << 2) >= (sizeof(*tcp) + 4))) { - ws = fr_tcpoptions(tcp); - if (ws >= 0) - is->is_swscale = ws; + /* + * Window scale option is only present in + * SYN/SYN-ACK packet. + */ + if ((tcp->th_flags & ~(TH_FIN|TH_ACK|TH_ECNALL)) == + TH_SYN && + (TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2))) { + if (fr_tcpoptions(fin, tcp, + &is->is_tcp.ts_data[0])) + is->is_swinflags = TCP_WSCALE_SEEN| + TCP_WSCALE_FIRST; } - } - is->is_maxdwin = 1; - is->is_maxswin = ntohs(tcp->th_win); - if (is->is_maxswin == 0) - is->is_maxswin = 1; + if ((fin->fin_out != 0) && (pass & FR_NEWISN) != 0) { + fr_checknewisn(fin, is); + fr_fixoutisn(fin, is); + } - if ((tcp->th_flags & TH_OPENING) == TH_SYN) - is->is_fsm = 1; + if ((tcp->th_flags & TH_OPENING) == TH_SYN) + flags |= IS_TCPFSM; + else { + is->is_maxdwin = is->is_maxswin * 2; + is->is_dend = ntohl(tcp->th_ack); + is->is_maxdend = ntohl(tcp->th_ack); + is->is_maxdwin *= 2; + } + } /* * If we're creating state for a starting connection, start the @@ -734,213 +1008,462 @@ u_int flags; break; case IPPROTO_UDP : - tcp = (tcphdr_t *)fin->fin_dp; + tcp = fin->fin_dp; is->is_sport = htons(fin->fin_data[0]); is->is_dport = htons(fin->fin_data[1]); - if ((flags & (FI_W_DPORT|FI_W_SPORT)) == 0) { - hv += is->is_sport; - hv += is->is_dport; + if ((flags & (SI_W_DPORT|SI_W_SPORT)) == 0) { + hv += tcp->th_dport; + hv += tcp->th_sport; } ATOMIC_INCL(ips_stats.iss_udp); - is->is_age = fr_udptimeout; break; + default : - is->is_age = fr_udptimeout; break; } + hv = DOUBLE_HASH(hv); + is->is_hv = hv; + is->is_rule = fr; + is->is_flags = flags & IS_INHERITED; + + /* + * Look for identical state. + */ + for (is = ips_table[is->is_hv % fr_statesize]; is != NULL; + is = is->is_hnext) { + if (bcmp(&ips.is_src, &is->is_src, + offsetof(struct ipstate, is_ps) - + offsetof(struct ipstate, is_src)) == 0) + break; + } + if (is != NULL) + return NULL; + if (ips_stats.iss_bucketlen[hv] >= fr_state_maxbucket) { + ATOMIC_INCL(ips_stats.iss_bucketfull); + return NULL; + } KMALLOC(is, ipstate_t *); if (is == NULL) { ATOMIC_INCL(ips_stats.iss_nomem); return NULL; } bcopy((char *)&ips, (char *)is, sizeof(*is)); - hv %= fr_statesize; - is->is_hv = hv; - is->is_rule = fin->fin_fr; - if (is->is_rule != NULL) { - is->is_group = is->is_rule->fr_group; - ATOMIC_INC32(is->is_rule->fr_ref); - pass = is->is_rule->fr_flags; - is->is_frage[0] = is->is_rule->fr_age[0]; - is->is_frage[1] = is->is_rule->fr_age[1]; - if (is->is_frage[0] != 0) - is->is_age = is->is_frage[0]; - - is->is_ifp[(out << 1) + 1] = is->is_rule->fr_ifas[1]; - is->is_ifp[(1 - out) << 1] = is->is_rule->fr_ifas[2]; - is->is_ifp[((1 - out) << 1) + 1] = is->is_rule->fr_ifas[3]; - - if (((ifp = is->is_rule->fr_ifas[1]) != NULL) && - (ifp != (void *)-1)) - strncpy(is->is_ifname[(out << 1) + 1], - IFNAME(ifp), IFNAMSIZ); - if (((ifp = is->is_rule->fr_ifas[2]) != NULL) && - (ifp != (void *)-1)) - strncpy(is->is_ifname[(1 - out) << 1], - IFNAME(ifp), IFNAMSIZ); - if (((ifp = is->is_rule->fr_ifas[3]) != NULL) && - (ifp != (void *)-1)) - strncpy(is->is_ifname[((1 - out) << 1) + 1], - IFNAME(ifp), IFNAMSIZ); - } else + /* + * Do not do the modulous here, it is done in fr_stinsert(). + */ + if (fr != NULL) { + (void) strncpy(is->is_group, fr->fr_group, FR_GROUPLEN); + if (fr->fr_age[0] != 0) { + is->is_tqehead[0] = fr_addtimeoutqueue(&ips_utqe, + fr->fr_age[0]); + is->is_sti.tqe_flags |= TQE_RULEBASED; + } + if (fr->fr_age[1] != 0) { + is->is_tqehead[1] = fr_addtimeoutqueue(&ips_utqe, + fr->fr_age[1]); + is->is_sti.tqe_flags |= TQE_RULEBASED; + } + + is->is_tag = fr->fr_logtag; + + is->is_ifp[(out << 1) + 1] = fr->fr_ifas[1]; + is->is_ifp[(1 - out) << 1] = fr->fr_ifas[2]; + is->is_ifp[((1 - out) << 1) + 1] = fr->fr_ifas[3]; + + if (((ifp = fr->fr_ifas[1]) != NULL) && + (ifp != (void *)-1)) { + COPYIFNAME(ifp, is->is_ifname[(out << 1) + 1]); + } + if (((ifp = fr->fr_ifas[2]) != NULL) && + (ifp != (void *)-1)) { + COPYIFNAME(ifp, is->is_ifname[(1 - out) << 1]); + } + if (((ifp = fr->fr_ifas[3]) != NULL) && + (ifp != (void *)-1)) { + COPYIFNAME(ifp, is->is_ifname[((1 - out) << 1) + 1]); + } + } else { pass = fr_flags; + is->is_tag = FR_NOLOGTAG; + } is->is_ifp[out << 1] = fin->fin_ifp; - strncpy(is->is_ifname[out << 1], IFNAME(fin->fin_ifp), IFNAMSIZ); - - WRITE_ENTER(&ipf_state); + if (fin->fin_ifp != NULL) { + COPYIFNAME(fin->fin_ifp, is->is_ifname[out << 1]); + } + /* + * It may seem strange to set is_ref to 2, but fr_check() will call + * fr_statederef() after calling fr_addstate() and the idea is to + * have it exist at the end of fr_check() with is_ref == 1. + */ + is->is_ref = 2; is->is_pass = pass; - if ((flags & FI_IGNOREPKT) == 0) { - is->is_pkts = 1; - is->is_bytes = fin->fin_dlen + fin->fin_hlen; + is->is_pkts[0] = 0, is->is_bytes[0] = 0; + is->is_pkts[1] = 0, is->is_bytes[1] = 0; + is->is_pkts[2] = 0, is->is_bytes[2] = 0; + is->is_pkts[3] = 0, is->is_bytes[3] = 0; + if ((fin->fin_flx & FI_IGNORE) == 0) { + is->is_pkts[out] = 1; + is->is_bytes[out] = fin->fin_plen; + is->is_flx[out][0] = fin->fin_flx & FI_CMP; + is->is_flx[out][0] &= ~FI_OOW; } + + if (pass & FR_STSTRICT) + is->is_flags |= IS_STRICT; + + if (pass & FR_STATESYNC) + is->is_flags |= IS_STATESYNC; + /* * We want to check everything that is a property of this packet, * but we don't (automatically) care about it's fragment status as * this may change. */ is->is_v = fin->fin_v; - is->is_rulen = fin->fin_rule; - is->is_opt = fin->fin_fi.fi_optmsk; + is->is_opt = fin->fin_optmsk; is->is_optmsk = 0xffffffff; - is->is_sec = fin->fin_fi.fi_secmsk; + is->is_sec = fin->fin_secmsk; is->is_secmsk = 0xffff; - is->is_auth = fin->fin_fi.fi_auth; + is->is_auth = fin->fin_auth; is->is_authmsk = 0xffff; - is->is_flags = fin->fin_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++; + if (flags & (SI_WILDP|SI_WILDA)) { + ATOMIC_INCL(ips_stats.iss_wild); + } + is->is_rulen = fin->fin_rule; + if (pass & FR_LOGFIRST) is->is_pass &= ~(FR_LOGFIRST|FR_LOG); - fr_stinsert(is); + + READ_ENTER(&ipf_state); is->is_me = stsave; - if (is->is_p == IPPROTO_TCP) { - fr_tcp_age(&is->is_age, is->is_state, fin, - 0, is->is_fsm); /* 0 = packet from the source */ + + fr_stinsert(is, fin->fin_rev); + + if (fin->fin_p == IPPROTO_TCP) { + /* + * If we're creating state for a starting connection, start the + * timer on it as we'll never see an error if it fails to + * connect. + */ + MUTEX_ENTER(&is->is_lock); + (void) fr_tcp_age(&is->is_sti, fin, ips_tqtqb, is->is_flags); + MUTEX_EXIT(&is->is_lock); +#ifdef IPFILTER_SCAN + if ((is->is_flags & SI_CLONE) == 0) + (void) ipsc_attachis(is); +#endif } -#ifdef IPFILTER_LOG - ipstate_log(is, ISL_NEW); +#ifdef IPFILTER_SYNC + if ((is->is_flags & IS_STATESYNC) && ((is->is_flags & SI_CLONE) == 0)) + is->is_sync = ipfsync_new(SMC_STATE, fin, is); #endif + if (ipstate_logging) + ipstate_log(is, ISL_NEW); + RWLOCK_EXIT(&ipf_state); - fin->fin_rev = IP6NEQ(is->is_dst, fin->fin_fi.fi_dst); - if ((fin->fin_fl & FI_FRAG) && (pass & FR_KEEPFRAG)) - ipfr_newfrag(ip, fin); + fin->fin_state = is; + fin->fin_rev = IP6_NEQ(&is->is_dst, &fin->fin_daddr); + fin->fin_flx |= FI_STATE; + if (fin->fin_flx & FI_FRAG) + (void) fr_newfrag(fin, pass ^ FR_KEEPSTATE); + return is; } -static int fr_tcpoptions(tcp) +/* ------------------------------------------------------------------------ */ +/* Function: fr_tcpoptions */ +/* Returns: int - 1 == packet matches state entry, 0 == it does not */ +/* Parameters: fin(I) - pointer to packet information */ +/* tcp(I) - pointer to TCP packet header */ +/* td(I) - pointer to TCP data held as part of the state */ +/* */ +/* Look after the TCP header for any options and deal with those that are */ +/* present. Record details about those that we recogise. */ +/* ------------------------------------------------------------------------ */ +static int fr_tcpoptions(fin, tcp, td) +fr_info_t *fin; tcphdr_t *tcp; +tcpdata_t *td; { - u_char *opt, *last; - int wscale; + int off, mlen, ol, i, len, retval; + char buf[64], *s, opt; + mb_t *m = NULL; + + off = fin->fin_hlen + sizeof(*tcp); + len = (TCP_OFF(tcp) << 2) - sizeof(*tcp); + if (fin->fin_plen < off + len) + return 0; - opt = (u_char *) (tcp + 1); - last = ((u_char *)tcp) + (tcp->th_off << 2); + m = fin->fin_m; + off += fin->fin_ipoff; + mlen = MSGDSIZE(m) - off; + if (len > mlen) { + len = mlen; + retval = 0; + } else { + retval = 1; + } - /* If we don't find wscale here, we need to clear it */ - wscale = -2; + COPYDATA(m, off, len, buf); - /* Termination condition picked such that opt[0 .. 2] exist */ - while ((opt < last - 2) && (*opt != TCPOPT_EOL)) { - switch (*opt) { - case TCPOPT_NOP: - opt++; - continue; - case TCPOPT_WSCALE: - /* Proper length ? */ - if (opt[1] == 3) { - if (opt[2] > 14) - wscale = 14; - else - wscale = opt[2]; - } + for (s = buf; len > 0; ) { + opt = *s; + if (opt == TCPOPT_EOL) break; - default: - /* Unknown options must be two bytes+ */ - if (opt[1] < 2) + else if (opt == TCPOPT_NOP) + ol = 1; + else { + if (len < 2) break; - opt += opt[1]; - continue; + ol = (int)*(s + 1); + if (ol < 2 || ol > len) + break; + + /* + * Extract the TCP options we are interested in out of + * the header and store them in the the tcpdata struct. + */ + switch (opt) + { + case TCPOPT_WINDOW : + if (ol == TCPOLEN_WINDOW) { + i = (int)*(s + 2); + if (i > TCP_WSCALE_MAX) + i = TCP_WSCALE_MAX; + else if (i < 0) + i = 0; + td->td_winscale = i; + } + break; + case TCPOPT_MAXSEG : + /* + * So, if we wanted to set the TCP MAXSEG, + * it should be done here... + */ + if (ol == TCPOLEN_MAXSEG) { + i = (int)*(s + 2); + i <<= 8; + i += (int)*(s + 3); + td->td_maxseg = i; + } + break; + } } - break; + len -= ol; + s += ol; } - return wscale; + return retval; } - -/* - * 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; +/* ------------------------------------------------------------------------ */ +/* Function: fr_tcpstate */ +/* Returns: int - 1 == packet matches state entry, 0 == it does not */ +/* Parameters: fin(I) - pointer to packet information */ +/* tcp(I) - pointer to TCP packet header */ +/* is(I) - pointer to master state structure */ +/* */ +/* Check to see if a packet with TCP headers fits within the TCP window. */ +/* Change timeout depending on whether new packet is a SYN-ACK returning */ +/* for a SYN or a RST or FIN which indicate time to close up shop. */ +/* ------------------------------------------------------------------------ */ +static int fr_tcpstate(fin, tcp, is) fr_info_t *fin; -ip_t *ip; tcphdr_t *tcp; +ipstate_t *is; { - register tcp_seq seq, ack, end; - register int ackskew; + int source, ret = 0, flags; tcpdata_t *fdata, *tdata; - u_32_t win, maxwin; - int ret = 0, off; - int source; - int wscale; - /* - * Find difference between last checked packet and this packet. - */ - source = IP6EQ(fin->fin_fi.fi_src, is->is_src); - if (source && (ntohs(is->is_sport) != fin->fin_data[0])) + source = !fin->fin_rev; + if (((is->is_flags & IS_TCPFSM) != 0) && (source == 1) && + (ntohs(is->is_sport) != fin->fin_data[0])) source = 0; fdata = &is->is_tcp.ts_data[!source]; tdata = &is->is_tcp.ts_data[source]; - off = tcp->th_off << 2; - seq = ntohl(tcp->th_seq); - ack = ntohl(tcp->th_ack); - win = ntohs(tcp->th_win); - end = seq + fin->fin_dlen - off + - ((tcp->th_flags & TH_SYN) ? 1 : 0) + - ((tcp->th_flags & TH_FIN) ? 1 : 0); + MUTEX_ENTER(&is->is_lock); + if (fr_tcpinwindow(fin, fdata, tdata, tcp, is->is_flags)) { +#ifdef IPFILTER_SCAN + if (is->is_flags & (IS_SC_CLIENT|IS_SC_SERVER)) { + ipsc_packet(fin, is); + if (FR_ISBLOCK(is->is_pass)) { + MUTEX_EXIT(&is->is_lock); + return 1; + } + } +#endif - if ((tcp->th_flags & TH_SYN) && (off >= sizeof(*tcp) + 4)) - wscale = fr_tcpoptions(tcp); + /* + * Nearing end of connection, start timeout. + */ + ret = fr_tcp_age(&is->is_sti, fin, ips_tqtqb, is->is_flags); + if (ret == 0) { + MUTEX_EXIT(&is->is_lock); + return 0; + } + + /* + * set s0's as appropriate. Use syn-ack packet as it + * contains both pieces of required information. + */ + /* + * Window scale option is only present in SYN/SYN-ACK packet. + * Compare with ~TH_FIN to mask out T/TCP setups. + */ + flags = tcp->th_flags & ~(TH_FIN|TH_ECNALL); + if (flags == (TH_SYN|TH_ACK)) { + is->is_s0[source] = ntohl(tcp->th_ack); + is->is_s0[!source] = ntohl(tcp->th_seq) + 1; + if ((TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2)) && + tdata->td_winscale) { + if (fr_tcpoptions(fin, tcp, fdata)) { + fdata->td_winflags = TCP_WSCALE_SEEN| + TCP_WSCALE_FIRST; + } else { + if (!fdata->td_winscale) + tdata->td_winscale = 0; + } + } + if ((fin->fin_out != 0) && (is->is_pass & FR_NEWISN)) + fr_checknewisn(fin, is); + } else if (flags == TH_SYN) { + is->is_s0[source] = ntohl(tcp->th_seq) + 1; + if ((TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2))) + if (fr_tcpoptions(fin, tcp, tdata)) { + tdata->td_winflags = TCP_WSCALE_SEEN| + TCP_WSCALE_FIRST; + } + + if ((fin->fin_out != 0) && (is->is_pass & FR_NEWISN)) + fr_checknewisn(fin, is); + + } + ret = 1; + } else + fin->fin_flx |= FI_OOW; + MUTEX_EXIT(&is->is_lock); + return ret; +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_checknewisn */ +/* Returns: Nil */ +/* Parameters: fin(I) - pointer to packet information */ +/* is(I) - pointer to master state structure */ +/* */ +/* Check to see if this TCP connection is expecting and needs a new */ +/* sequence number for a particular direction of the connection. */ +/* */ +/* NOTE: This does not actually change the sequence numbers, only gets new */ +/* one ready. */ +/* ------------------------------------------------------------------------ */ +static void fr_checknewisn(fin, is) +fr_info_t *fin; +ipstate_t *is; +{ + u_32_t sumd, old, new; + tcphdr_t *tcp; + int i; + + i = fin->fin_rev; + tcp = fin->fin_dp; + + if (((i == 0) && !(is->is_flags & IS_ISNSYN)) || + ((i == 1) && !(is->is_flags & IS_ISNACK))) { + old = ntohl(tcp->th_seq); + new = fr_newisn(fin); + is->is_isninc[i] = new - old; + CALC_SUMD(old, new, sumd); + is->is_sumd[i] = (sumd & 0xffff) + (sumd >> 16); + + is->is_flags |= ((i == 0) ? IS_ISNSYN : IS_ISNACK); + } +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_tcpinwindow */ +/* Returns: int - 1 == packet inside TCP "window", 0 == not inside. */ +/* Parameters: fin(I) - pointer to packet information */ +/* fdata(I) - pointer to tcp state informatio (forward) */ +/* tdata(I) - pointer to tcp state informatio (reverse) */ +/* tcp(I) - pointer to TCP packet header */ +/* */ +/* Given a packet has matched addresses and ports, check to see if it is */ +/* within the TCP data window. In a show of generosity, allow packets that */ +/* are within the window space behind the current sequence # as well. */ +/* ------------------------------------------------------------------------ */ +int fr_tcpinwindow(fin, fdata, tdata, tcp, flags) +fr_info_t *fin; +tcpdata_t *fdata, *tdata; +tcphdr_t *tcp; +int flags; +{ + tcp_seq seq, ack, end; + int ackskew, tcpflags; + u_32_t win, maxwin; + + /* + * Find difference between last checked packet and this packet. + */ + tcpflags = tcp->th_flags; + seq = ntohl(tcp->th_seq); + ack = ntohl(tcp->th_ack); + if (tcpflags & TH_SYN) + win = ntohs(tcp->th_win); else - wscale = -1; + win = ntohs(tcp->th_win) << fdata->td_winscale; + if (win == 0) + win = 1; - MUTEX_ENTER(&is->is_lock); + /* + * if window scaling is present, the scaling is only allowed + * for windows not in the first SYN packet. In that packet the + * window is 65535 to specify the largest window possible + * for receivers not implementing the window scale option. + * Currently, we do not assume TTCP here. That means that + * if we see a second packet from a host (after the initial + * SYN), we can assume that the receiver of the SYN did + * already send back the SYN/ACK (and thus that we know if + * the receiver also does window scaling) + */ + if (!(tcpflags & TH_SYN) && (fdata->td_winflags & TCP_WSCALE_FIRST)) { + if (tdata->td_winflags & TCP_WSCALE_SEEN) { + fdata->td_winflags &= ~TCP_WSCALE_FIRST; + fdata->td_maxwin = win; + } else { + fdata->td_winscale = 0; + fdata->td_winflags = 0; + tdata->td_winscale = 0; + tdata->td_winflags = 0; + } + } - if (wscale >= 0) - fdata->td_wscale = wscale; - else if (wscale == -2) - fdata->td_wscale = tdata->td_wscale = 0; - if (!(tcp->th_flags & TH_SYN)) - win <<= fdata->td_wscale; + end = seq + fin->fin_dlen - (TCP_OFF(tcp) << 2) + + ((tcpflags & TH_SYN) ? 1 : 0) + ((tcpflags & TH_FIN) ? 1 : 0); if ((fdata->td_end == 0) && - (!is->is_fsm || ((tcp->th_flags & TH_OPENING) == TH_OPENING))) { + (!(flags & IS_TCPFSM) || + ((tcpflags & TH_OPENING) == TH_OPENING))) { /* * Must be a (outgoing) SYN-ACK in reply to a SYN. */ fdata->td_end = end; fdata->td_maxwin = 1; fdata->td_maxend = end + win; - if (win == 0) - fdata->td_maxend++; } - if (!(tcp->th_flags & TH_ACK)) { /* Pretend an ack was sent */ + if (!(tcpflags & TH_ACK)) { /* Pretend an ack was sent */ ack = tdata->td_end; - } else if (((tcp->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) && + } else if (((tcpflags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) && (ack == 0)) { /* gross hack to get around certain broken tcp stacks */ ack = tdata->td_end; @@ -952,14 +1475,26 @@ tcphdr_t *tcp; maxwin = tdata->td_maxwin; ackskew = tdata->td_end - ack; + /* + * Strict sequencing only allows in-order delivery. + */ + if ((flags & IS_STRICT) != 0) { + if (seq != fdata->td_end) { + return 0; + } + } + #define SEQ_GE(a,b) ((int)((a) - (b)) >= 0) #define SEQ_GT(a,b) ((int)((a) - (b)) > 0) - if ((SEQ_GE(fdata->td_maxend, end)) && + if ( +#if defined(_KERNEL) + (SEQ_GE(fdata->td_maxend, end)) && (SEQ_GE(seq, fdata->td_end - maxwin)) && +#endif /* XXX what about big packets */ #define MAXACKWINDOW 66000 - (-ackskew <= (MAXACKWINDOW << tdata->td_wscale)) && - ( ackskew <= (MAXACKWINDOW << tdata->td_wscale))) { + (-ackskew <= (MAXACKWINDOW << fdata->td_winscale)) && + ( ackskew <= (MAXACKWINDOW << fdata->td_winscale))) { /* if ackskew < 0 then this should be due to fragmented * packets. There is no way to know the length of the @@ -975,220 +1510,358 @@ tcphdr_t *tcp; * Thus, when ackskew is negative but still seems to belong * to this session, we bump up the destinations end value. */ - /* - * Nearing end of connection, start timeout. - */ - /* source ? 0 : 1 -> !source */ - if (fr_tcp_age(&is->is_age, is->is_state, fin, !source, - (int)is->is_fsm) == 0) { - 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); - ret = 1; - } + if (ackskew < 0) + tdata->td_end = ack; + + /* update max window seen */ + if (fdata->td_maxwin < win) + fdata->td_maxwin = win; + if (SEQ_GT(end, fdata->td_end)) + fdata->td_end = end; + if (SEQ_GE(ack + win, tdata->td_maxend)) + tdata->td_maxend = ack + win; + return 1; } - MUTEX_EXIT(&is->is_lock); - if ((ret == 0) && ((tcp->th_flags & TH_OPENING) != TH_SYN)) - fin->fin_misc |= FM_BADSTATE; - return ret; + return 0; } -/* - * Match a state table entry against an IP packet. - */ -static int fr_matchsrcdst(is, src, dst, fin, tcp) +/* ------------------------------------------------------------------------ */ +/* Function: fr_stclone */ +/* Returns: ipstate_t* - NULL == cloning failed, */ +/* else pointer to new state structure */ +/* Parameters: fin(I) - pointer to packet information */ +/* tcp(I) - pointer to TCP/UDP header */ +/* is(I) - pointer to master state structure */ +/* */ +/* Create a "duplcate" state table entry from the master. */ +/* ------------------------------------------------------------------------ */ +static ipstate_t *fr_stclone(fin, tcp, is) +fr_info_t *fin; +tcphdr_t *tcp; ipstate_t *is; -union i6addr src, dst; +{ + ipstate_t *clone; + u_32_t send; + + if (ips_num == fr_statemax) { + ATOMIC_INCL(ips_stats.iss_max); + fr_state_doflush = 1; + return NULL; + } + KMALLOC(clone, ipstate_t *); + if (clone == NULL) + return NULL; + bcopy((char *)is, (char *)clone, sizeof(*clone)); + + MUTEX_NUKE(&clone->is_lock); + + clone->is_die = ONE_DAY + fr_ticks; + clone->is_state[0] = 0; + clone->is_state[1] = 0; + send = ntohl(tcp->th_seq) + fin->fin_dlen - (TCP_OFF(tcp) << 2) + + ((tcp->th_flags & TH_SYN) ? 1 : 0) + + ((tcp->th_flags & TH_FIN) ? 1 : 0); + + if (fin->fin_rev == 1) { + clone->is_dend = send; + clone->is_maxdend = send; + clone->is_send = 0; + clone->is_maxswin = 1; + clone->is_maxdwin = ntohs(tcp->th_win); + if (clone->is_maxdwin == 0) + clone->is_maxdwin = 1; + } else { + clone->is_send = send; + clone->is_maxsend = send; + clone->is_dend = 0; + clone->is_maxdwin = 1; + clone->is_maxswin = ntohs(tcp->th_win); + if (clone->is_maxswin == 0) + clone->is_maxswin = 1; + } + + clone->is_flags &= ~SI_CLONE; + clone->is_flags |= SI_CLONED; + fr_stinsert(clone, fin->fin_rev); + MUTEX_ENTER(&clone->is_lock); + clone->is_ref = 1; + if (clone->is_p == IPPROTO_TCP) { + (void) fr_tcp_age(&clone->is_sti, fin, ips_tqtqb, + clone->is_flags); + } + MUTEX_EXIT(&clone->is_lock); +#ifdef IPFILTER_SCAN + (void) ipsc_attachis(is); +#endif +#ifdef IPFILTER_SYNC + if (is->is_flags & IS_STATESYNC) + clone->is_sync = ipfsync_new(SMC_STATE, fin, clone); +#endif + return clone; +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_matchsrcdst */ +/* Returns: Nil */ +/* Parameters: fin(I) - pointer to packet information */ +/* is(I) - pointer to state structure */ +/* src(I) - pointer to source address */ +/* dst(I) - pointer to destination address */ +/* tcp(I) - pointer to TCP/UDP header */ +/* */ +/* Match a state table entry against an IP packet. The logic below is that */ +/* ret gets set to one if the match succeeds, else remains 0. If it is */ +/* still 0 after the test. no match. */ +/* ------------------------------------------------------------------------ */ +static ipstate_t *fr_matchsrcdst(fin, is, src, dst, tcp, cmask) fr_info_t *fin; +ipstate_t *is; +i6addr_t *src, *dst; tcphdr_t *tcp; +u_32_t cmask; { - int ret = 0, rev, out, flags, idx; + int ret = 0, rev, out, flags, flx = 0, idx; u_short sp, dp; + u_32_t cflx; void *ifp; - rev = IP6NEQ(is->is_dst, dst); + rev = IP6_NEQ(&is->is_dst, dst); ifp = fin->fin_ifp; out = fin->fin_out; - flags = is->is_flags & (FI_WILDA|FI_WILDP); + flags = is->is_flags; sp = 0; dp = 0; if (tcp != NULL) { - flags = is->is_flags; - sp = tcp->th_sport; - dp = tcp->th_dport; - if (!rev) { - if (!(flags & FI_W_SPORT) && (sp != is->is_sport)) + sp = htons(fin->fin_sport); + dp = ntohs(fin->fin_dport); + } + if (!rev) { + if (tcp != NULL) { + if (!(flags & SI_W_SPORT) && (sp != is->is_sport)) rev = 1; - else if (!(flags & FI_W_DPORT) && (dp != is->is_dport)) + else if (!(flags & SI_W_DPORT) && (dp != is->is_dport)) rev = 1; } } idx = (out << 1) + rev; - if ((is->is_ifp[idx] == NULL && - (*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '*')) || + /* + * If the interface for this 'direction' is set, make sure it matches. + * An interface name that is not set matches any, as does a name of *. + */ + if ((is->is_ifp[idx] == NULL && + (*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '*')) || is->is_ifp[idx] == ifp) ret = 1; if (ret == 0) - return 0; + return NULL; ret = 0; + /* + * Match addresses and ports. + */ 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; + if ((IP6_EQ(&is->is_dst, dst) || (flags & SI_W_DADDR)) && + (IP6_EQ(&is->is_src, src) || (flags & SI_W_SADDR))) { + if (tcp) { + if ((sp == is->is_sport || flags & SI_W_SPORT)&& + (dp == is->is_dport || flags & SI_W_DPORT)) + ret = 1; + } else { + ret = 1; + } } } else { - if ((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 ((IP6_EQ(&is->is_dst, src) || (flags & SI_W_DADDR)) && + (IP6_EQ(&is->is_src, dst) || (flags & SI_W_SADDR))) { + if (tcp) { + if ((dp == is->is_sport || flags & SI_W_SPORT)&& + (sp == is->is_dport || flags & SI_W_DPORT)) + ret = 1; + } else { + ret = 1; + } } } + if (ret == 0) - return 0; + return NULL; /* * Whether or not this should be here, is questionable, but the aim * is to get this out of the main line. */ if (tcp == NULL) - flags = is->is_flags & (FI_CMP|(FI_CMP<<4)); + flags = is->is_flags & ~(SI_WILDP|SI_NEWFR|SI_CLONE|SI_CLONED); - if (((fin->fin_fl & (flags >> 4)) != (flags & FI_CMP)) || - (fin->fin_fi.fi_optmsk != is->is_opt) || - (fin->fin_fi.fi_secmsk != is->is_sec) || - (fin->fin_fi.fi_auth != is->is_auth)) - return 0; + /* + * Only one of the source or destination address can be flaged as a + * wildcard. Fill in the missing address, if set. + * For IPv6, if the address being copied in is multicast, then + * don't reset the wild flag - multicast causes it to be set in the + * first place! + */ + if ((flags & (SI_W_SADDR|SI_W_DADDR))) { + fr_ip_t *fi = &fin->fin_fi; - flags = is->is_flags & (FI_WILDA|FI_WILDP); - if ((flags & (FI_W_SADDR|FI_W_DADDR))) { - if ((flags & FI_W_SADDR) != 0) { + if ((flags & SI_W_SADDR) != 0) { if (rev == 0) { - is->is_src = fin->fin_fi.fi_src; +#ifdef USE_INET6 + if (is->is_v == 6 && + IN6_IS_ADDR_MULTICAST(&fi->fi_src.in6)) + /*EMPTY*/; + else +#endif + { + is->is_src = fi->fi_src; + is->is_flags &= ~SI_W_SADDR; + } } else { - is->is_src = fin->fin_fi.fi_dst; +#ifdef USE_INET6 + if (is->is_v == 6 && + IN6_IS_ADDR_MULTICAST(&fi->fi_dst.in6)) + /*EMPTY*/; + else +#endif + { + is->is_src = fi->fi_dst; + is->is_flags &= ~SI_W_SADDR; + } } - } else if ((flags & FI_W_DADDR) != 0) { + } else if ((flags & SI_W_DADDR) != 0) { if (rev == 0) { - is->is_dst = fin->fin_fi.fi_dst; +#ifdef USE_INET6 + if (is->is_v == 6 && + IN6_IS_ADDR_MULTICAST(&fi->fi_dst.in6)) + /*EMPTY*/; + else +#endif + { + is->is_dst = fi->fi_dst; + is->is_flags &= ~SI_W_DADDR; + } } else { - is->is_dst = fin->fin_fi.fi_src; +#ifdef USE_INET6 + if (is->is_v == 6 && + IN6_IS_ADDR_MULTICAST(&fi->fi_src.in6)) + /*EMPTY*/; + else +#endif + { + is->is_dst = fi->fi_src; + is->is_flags &= ~SI_W_DADDR; + } } } - is->is_flags &= ~(FI_W_SADDR|FI_W_DADDR); - if ((is->is_flags & (FI_WILDA|FI_WILDP)) == 0) - ips_wild--; + if ((is->is_flags & (SI_WILDA|SI_WILDP)) == 0) { + ATOMIC_DECL(ips_stats.iss_wild); + } } - if ((flags & (FI_W_SPORT|FI_W_DPORT))) { - if ((flags & FI_W_SPORT) != 0) { + flx = fin->fin_flx & cmask; + cflx = is->is_flx[out][rev]; + + /* + * Match up any flags set from IP options. + */ + if ((cflx && (flx != (cflx & cmask))) || + ((fin->fin_optmsk & is->is_optmsk) != is->is_opt) || + ((fin->fin_secmsk & is->is_secmsk) != is->is_sec) || + ((fin->fin_auth & is->is_authmsk) != is->is_auth)) + return NULL; + + /* + * Only one of the source or destination port can be flagged as a + * wildcard. When filling it in, fill in a copy of the matched entry + * if it has the cloning flag set. + */ + if ((fin->fin_flx & FI_IGNORE) != 0) { + fin->fin_rev = rev; + return is; + } + + if ((flags & (SI_W_SPORT|SI_W_DPORT))) { + if ((flags & SI_CLONE) != 0) { + is = fr_stclone(fin, tcp, is); + if (is == NULL) + return NULL; + } else { + ATOMIC_DECL(ips_stats.iss_wild); + } + + if ((flags & SI_W_SPORT) != 0) { if (rev == 0) { is->is_sport = sp; - is->is_send = htonl(tcp->th_seq); + is->is_send = ntohl(tcp->th_seq); } else { is->is_sport = dp; - is->is_send = htonl(tcp->th_ack); + is->is_send = ntohl(tcp->th_ack); } is->is_maxsend = is->is_send + 1; - } else if ((flags & FI_W_DPORT) != 0) { + } else if ((flags & SI_W_DPORT) != 0) { if (rev == 0) { is->is_dport = dp; - is->is_dend = htonl(tcp->th_ack); + is->is_dend = ntohl(tcp->th_ack); } else { is->is_dport = sp; - is->is_dend = htonl(tcp->th_seq); + is->is_dend = ntohl(tcp->th_seq); } is->is_maxdend = is->is_dend + 1; } - is->is_flags &= ~(FI_W_SPORT|FI_W_DPORT); - ips_wild--; + is->is_flags &= ~(SI_W_SPORT|SI_W_DPORT); + if ((flags & SI_CLONED) && ipstate_logging) + ipstate_log(is, ISL_CLONE); } ret = -1; - if (is->is_ifp[idx] == NULL && - (*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '*')) - ret = idx; + if (is->is_flx[out][rev] == 0) + is->is_flx[out][rev] = flx; - if (ret >= 0) { - is->is_ifp[ret] = ifp; - strncpy(is->is_ifname[ret], IFNAME(ifp), - sizeof(is->is_ifname[ret])); + /* + * Check if the interface name for this "direction" is set and if not, + * fill it in. + */ + if (is->is_ifp[idx] == NULL && + (*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '*')) { + is->is_ifp[idx] = ifp; + COPYIFNAME(ifp, is->is_ifname[idx]); } fin->fin_rev = rev; - return 1; + return is; } -static int fr_matchicmpqueryreply(v, is, icmp, rev) -int v; -ipstate_t *is; -icmphdr_t *icmp; -int rev; -{ - if (v == 4) { - /* - * If we matched its type on the way in, then when going out - * it will still be the same type. - */ - if ((!rev && (icmp->icmp_type == is->is_type)) || - (rev && (icmpreplytype4[is->is_type] == icmp->icmp_type))) { - if (icmp->icmp_type != ICMP_ECHOREPLY) - return 1; - if ((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 ((!rev && (icmp->icmp_type == is->is_type)) || - (rev && (icmpreplytype6[is->is_type] == icmp->icmp_type))) { - if (icmp->icmp_type != ICMP6_ECHO_REPLY) - return 1; - if ((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; +/* ------------------------------------------------------------------------ */ +/* Function: fr_checkicmpmatchingstate */ +/* Returns: Nil */ +/* Parameters: fin(I) - pointer to packet information */ +/* */ +/* If we've got an ICMP error message, using the information stored in the */ +/* ICMP packet, look for a matching state table entry. */ +/* */ +/* If we return NULL then no lock on ipf_state is held. */ +/* If we return non-null then a read-lock on ipf_state is held. */ +/* ------------------------------------------------------------------------ */ +static ipstate_t *fr_checkicmpmatchingstate(fin) fr_info_t *fin; { - register ipstate_t *is, **isp; - register u_short sport, dport; - register u_char pr; - u_short savelen, ohlen; - union i6addr dst, src; + ipstate_t *is, **isp; + u_short sport, dport; + u_char pr; + int backward, i, oi; + i6addr_t dst, src; struct icmp *ic; + u_short savelen; icmphdr_t *icmp; fr_info_t ofin; - int type, len; tcphdr_t *tcp; - frentry_t *fr; + int type, len; ip_t *oip; u_int hv; @@ -1197,11 +1870,10 @@ fr_info_t *fin; * Only a basic IP header (no options) should be with * an ICMP error header. */ - if (((ip->ip_v != 4) || (ip->ip_hl != 5)) || + if ((fin->fin_v != 4) || (fin->fin_hlen != sizeof(ip_t)) || (fin->fin_plen < ICMPERR_MINPKTLEN)) return NULL; - - ic = (struct icmp *)fin->fin_dp; + ic = fin->fin_dp; type = ic->icmp_type; /* * If it's not an error type, then return @@ -1212,19 +1884,18 @@ fr_info_t *fin; return NULL; oip = (ip_t *)((char *)ic + ICMPERR_ICMPHLEN); - ohlen = oip->ip_hl << 2; /* * Check if the at least the old IP header (with options) and * 8 bytes of payload is present. */ - if (fin->fin_plen < ICMPERR_MAXPKTLEN + ohlen - sizeof(*oip)) + if (fin->fin_plen < ICMPERR_MAXPKTLEN + ((IP_HL(oip) - 5) << 2)) return NULL; /* - * Sanity checks. + * Sanity Checks. */ len = fin->fin_dlen - ICMPERR_ICMPHLEN; - if ((len <= 0) || (ohlen > len)) + if ((len <= 0) || ((IP_HL(oip) << 2) > len)) return NULL; /* @@ -1240,52 +1911,56 @@ fr_info_t *fin; { mb_t *m; -# if SOLARIS - m = fin->fin_qfm; + m = fin->fin_m; +# if defined(MENTAT) 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) + if ((char *)oip + len > (char *)fin->fin_ip + m->m_len) return NULL; # endif } #endif + bcopy((char *)fin, (char *)&ofin, sizeof(fin)); /* * in the IPv4 case we must zero the i6addr union otherwise - * the IP6EQ and IP6NEQ macros produce the wrong results because + * the IP6_EQ and IP6_NEQ macros produce the wrong results because * of the 'junk' in the unused part of the union */ bzero((char *)&src, sizeof(src)); bzero((char *)&dst, sizeof(dst)); - bzero((char *)&ofin, sizeof(ofin)); + /* - * 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 that we - * fill in fin_mp such that if someone uses it we'll get + * 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. - */ - ofin.fin_ifp = fin->fin_ifp; - ofin.fin_out = !fin->fin_out; - ofin.fin_mp = NULL; - ofin.fin_v = 4; - /* + * * watch out here, as ip is in host order and oip in network * order. Any change we make must be undone afterwards, like * oip->ip_off - it is still in network byte order so fix it. */ savelen = oip->ip_len; oip->ip_len = len; - oip->ip_off = ntohs(oip->ip_off); - (void) fr_makefrip(ohlen, oip, &ofin); + oip->ip_off = htons(oip->ip_off); + + ofin.fin_flx = FI_NOCKSUM; + ofin.fin_v = 4; + ofin.fin_ip = oip; + ofin.fin_m = NULL; /* if dereferenced, panic XXX */ + ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ + ofin.fin_plen = fin->fin_dlen - ICMPERR_ICMPHLEN; + (void) fr_makefrip(IP_HL(oip) << 2, oip, &ofin); + ofin.fin_ifp = fin->fin_ifp; + ofin.fin_out = !fin->fin_out; /* - * Reset the short flag here because in fr_matchsrcdst() the flags - * for the current packet (fin_fl) are compared against * those for - * the existing session. + * Reset the short and bad flag here because in fr_matchsrcdst() + * the flags for the current packet (fin_flx) are compared against + * those for the existing session. */ - ofin.fin_fl &= ~FI_SHORT; + ofin.fin_flx &= ~(FI_BAD|FI_SHORT); /* * Put old values of ip_len and ip_off back as we don't know @@ -1294,15 +1969,10 @@ fr_info_t *fin; oip->ip_len = savelen; oip->ip_off = htons(oip->ip_off); -#if SOLARIS - ofin.fin_qfm = NULL; -#endif - fr = NULL; - switch (oip->ip_p) { case IPPROTO_ICMP : - icmp = (icmphdr_t *)((char *)oip + ohlen); + icmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2)); /* * an ICMP error can only be generated as a result of an @@ -1311,10 +1981,10 @@ fr_info_t *fin; * 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)) + if ((icmp->icmp_type != ICMP_ECHO) && + (icmp->icmp_type != ICMP_TSTAMP) && + (icmp->icmp_type != ICMP_IREQ) && + (icmp->icmp_type != ICMP_MASKREQ)) return NULL; /* @@ -1326,35 +1996,52 @@ fr_info_t *fin; dst.in4 = oip->ip_dst; hv += dst.in4.s_addr; hv += icmp->icmp_id; - hv += icmp->icmp_seq; - hv %= fr_statesize; + hv = DOUBLE_HASH(hv); READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_hnext) - if ((is->is_p == pr) && (is->is_v == 4) && - (is->is_icmppkts < is->is_pkts) && - fr_matchsrcdst(is, src, dst, &ofin, NULL) && - fr_matchicmpqueryreply(is->is_v, is, icmp, - fin->fin_rev)) { + for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { + isp = &is->is_hnext; + if ((is->is_p != pr) || (is->is_v != 4)) + continue; + if (is->is_pass & FR_NOICMPERR) + continue; + is = fr_matchsrcdst(&ofin, is, &src, &dst, + NULL, FI_ICMPCMP); + if (is != NULL) { + if ((is->is_pass & FR_NOICMPERR) != 0) { + RWLOCK_EXIT(&ipf_state); + return NULL; + } + /* + * i : the index of this packet (the icmp + * unreachable) + * oi : the index of the original packet found + * in the icmp header (i.e. the packet + * causing this icmp) + * backward : original packet was backward + * compared to the state + */ + backward = IP6_NEQ(&is->is_src, &src); + fin->fin_rev = !backward; + i = (!backward << 1) + fin->fin_out; + oi = (backward << 1) + ofin.fin_out; + if (is->is_icmppkts[i] > is->is_pkts[oi]) + continue; ips_stats.iss_hits++; - is->is_icmppkts++; - is->is_bytes += ip->ip_len; - fr = is->is_rule; - break; + is->is_icmppkts[i]++; + return is; } + } RWLOCK_EXIT(&ipf_state); - return fr; - + return NULL; case IPPROTO_TCP : case IPPROTO_UDP : - if (fin->fin_plen < ICMPERR_MAXPKTLEN) - return NULL; break; default : return NULL; } - tcp = (tcphdr_t *)((char *)oip + ohlen); + tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2)); dport = tcp->th_dport; sport = tcp->th_sport; @@ -1365,98 +2052,129 @@ fr_info_t *fin; hv += dst.in4.s_addr; hv += dport; hv += sport; - hv %= fr_statesize; + hv = DOUBLE_HASH(hv); READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_hnext) { + for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { + isp = &is->is_hnext; /* * Only allow this icmp though if the * encapsulated packet was allowed through the * other way around. Note that the minimal amount * of info present does not allow for checking against - * tcp internals such as seq and ack numbers. Only the + * tcp internals such as seq and ack numbers. Only the * ports are known to be present and can be even if the * short flag is set. */ if ((is->is_p == pr) && (is->is_v == 4) && - (is->is_icmppkts < is->is_pkts) && - fr_matchsrcdst(is, src, dst, &ofin, tcp)) { - fr = is->is_rule; + (is = fr_matchsrcdst(&ofin, is, &src, &dst, + tcp, FI_ICMPCMP))) { + /* + * i : the index of this packet (the icmp unreachable) + * oi : the index of the original packet found in the + * icmp header (i.e. the packet causing this icmp) + * backward : original packet was backward compared to + * the state + */ + backward = IP6_NEQ(&is->is_src, &src); + fin->fin_rev = !backward; + i = (!backward << 1) + fin->fin_out; + oi = (backward << 1) + ofin.fin_out; + + if (((is->is_pass & FR_NOICMPERR) != 0) || + (is->is_icmppkts[i] > is->is_pkts[oi])) + break; ips_stats.iss_hits++; - is->is_icmppkts++; - is->is_bytes += fin->fin_plen; + is->is_icmppkts[i]++; /* * we deliberately do not touch the timeouts * for the accompanying state table entry. * It remains to be seen if that is correct. XXX */ - break; + return is; } } RWLOCK_EXIT(&ipf_state); - return fr; + return NULL; } -/* - * Move a state hash table entry from its old location at is->is_hv to - * its new location, indexed by hv % fr_statesize. - */ -static void fr_ipsmove(isp, is, hv) -ipstate_t **isp, *is; +/* ------------------------------------------------------------------------ */ +/* Function: fr_ipsmove */ +/* Returns: Nil */ +/* Parameters: is(I) - pointer to state table entry */ +/* hv(I) - new hash value for state table entry */ +/* Write Locks: ipf_state */ +/* */ +/* Move a state entry from one position in the hash table to another. */ +/* ------------------------------------------------------------------------ */ +static void fr_ipsmove(is, hv) +ipstate_t *is; u_int hv; { + ipstate_t **isp; u_int hvm; + ASSERT(rw_read_locked(&ipf_state.ipf_lk) == 0); + hvm = is->is_hv; /* * Remove the hash from the old location... */ + isp = is->is_phnext; if (is->is_hnext) is->is_hnext->is_phnext = isp; *isp = is->is_hnext; if (ips_table[hvm] == NULL) ips_stats.iss_inuse--; + ips_stats.iss_bucketlen[hvm]--; /* * ...and put the hash in the new one. */ - hvm = hv % fr_statesize; + hvm = DOUBLE_HASH(hv); is->is_hv = hvm; isp = &ips_table[hvm]; if (*isp) (*isp)->is_phnext = &is->is_hnext; else ips_stats.iss_inuse++; + ips_stats.iss_bucketlen[hvm]++; is->is_phnext = isp; is->is_hnext = *isp; *isp = is; } -/* - * Check if a packet has a registered state. - */ -frentry_t *fr_checkstate(ip, fin) -ip_t *ip; +/* ------------------------------------------------------------------------ */ +/* Function: fr_stlookup */ +/* Returns: ipstate_t* - NULL == no matching state found, */ +/* else pointer to state information is returned */ +/* Parameters: fin(I) - pointer to packet information */ +/* tcp(I) - pointer to TCP/UDP header. */ +/* */ +/* Search the state table for a matching entry to the packet described by */ +/* the contents of *fin. */ +/* */ +/* If we return NULL then no lock on ipf_state is held. */ +/* If we return non-null then a read-lock on ipf_state is held. */ +/* ------------------------------------------------------------------------ */ +ipstate_t *fr_stlookup(fin, tcp, ifqp) fr_info_t *fin; +tcphdr_t *tcp; +ipftq_t **ifqp; { - union i6addr dst, src; - register ipstate_t *is, **isp; - register u_char pr; - u_int hv, hvm, hlen, tryagain, pass, v; + u_int hv, hvm, pr, v, tryagain; + ipstate_t *is, **isp; + u_short dport, sport; + i6addr_t src, dst; struct icmp *ic; - frentry_t *fr; - tcphdr_t *tcp; - int rev; - - if ((ips_list == NULL) || (fin->fin_off != 0) || fr_state_lock || - (fin->fin_fl & FI_SHORT)) - return NULL; + ipftq_t *ifq; + int oow; is = NULL; - hlen = fin->fin_hlen; - tcp = (tcphdr_t *)((char *)ip + hlen); + ifq = NULL; + tcp = fin->fin_dp; ic = (struct icmp *)tcp; hv = (pr = fin->fin_fi.fi_p); src = fin->fin_fi.fi_src; @@ -1464,18 +2182,12 @@ fr_info_t *fin; hv += src.in4.s_addr; hv += dst.in4.s_addr; - /* - * Search the hash table for matching packet header info. - * At the bottom of this switch statement, the following is expected: - * is == NULL, no lock on ipf_state is held. - * is != NULL, a lock on ipf_state is held. - */ v = fin->fin_fi.fi_v; #ifdef USE_INET6 if (v == 6) { - hv += fin->fin_fi.fi_src.i6[1]; - hv += fin->fin_fi.fi_src.i6[2]; - hv += fin->fin_fi.fi_src.i6[3]; + hv += fin->fin_fi.fi_src.i6[1]; + hv += fin->fin_fi.fi_src.i6[2]; + hv += fin->fin_fi.fi_src.i6[3]; if ((fin->fin_p == IPPROTO_ICMPV6) && IN6_IS_ADDR_MULTICAST(&fin->fin_fi.fi_dst.in6)) { @@ -1488,43 +2200,46 @@ fr_info_t *fin; } #endif - switch (fin->fin_p) + /* + * Search the hash table for matching packet header info. + */ + switch (pr) { #ifdef USE_INET6 case IPPROTO_ICMPV6 : - tcp = NULL; tryagain = 0; if (v == 6) { if ((ic->icmp_type == ICMP6_ECHO_REQUEST) || (ic->icmp_type == ICMP6_ECHO_REPLY)) { hv += ic->icmp_id; - hv += ic->icmp_seq; } } READ_ENTER(&ipf_state); icmp6again: - 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, NULL) && - fr_matchicmpqueryreply(v, is, ic, fin->fin_rev)) { - rev = fin->fin_rev; - if (is->is_frage[rev] != 0) - is->is_age = is->is_frage[rev]; - else if (rev != 0) - is->is_age = fr_icmpacktimeout; + hvm = DOUBLE_HASH(hv); + for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) { + isp = &is->is_hnext; + if ((is->is_p != pr) || (is->is_v != v)) + continue; + is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); + if (is != NULL && + fr_matchicmpqueryreply(v, &is->is_icmp, + ic, fin->fin_rev)) { + if (fin->fin_rev) + ifq = &ips_icmpacktq; else - is->is_age = fr_icmptimeout; + ifq = &ips_icmptq; break; } + } if (is != NULL) { - if (tryagain && !(is->is_flags & FI_W_DADDR)) { + if ((tryagain != 0) && !(is->is_flags & SI_W_DADDR)) { hv += fin->fin_fi.fi_src.i6[0]; hv += fin->fin_fi.fi_src.i6[1]; hv += fin->fin_fi.fi_src.i6[2]; hv += fin->fin_fi.fi_src.i6[3]; - fr_ipsmove(isp, is, hv); + fr_ipsmove(is, hv); MUTEX_DOWNGRADE(&ipf_state); } break; @@ -1534,8 +2249,14 @@ icmp6again: /* * No matching icmp state entry. Perhaps this is a * response to another state entry. + * + * XXX With some ICMP6 packets, the "other" address is already + * in the packet, after the ICMP6 header, and this could be + * used in place of the multicast address. However, taking + * advantage of this requires some significant code changes + * to handle the specific types where that is the case. */ - if ((ips_wild != 0) && (v == 6) && (tryagain == 0) && + if ((ips_stats.iss_wild != 0) && (v == 6) && (tryagain == 0) && !IN6_IS_ADDR_MULTICAST(&fin->fin_fi.fi_src.in6)) { hv -= fin->fin_fi.fi_src.i6[0]; hv -= fin->fin_fi.fi_src.i6[1]; @@ -1546,113 +2267,107 @@ icmp6again: goto icmp6again; } - fr = fr_checkicmp6matchingstate((ip6_t *)ip, fin); - if (fr) - return fr; + is = fr_checkicmp6matchingstate(fin); + if (is != NULL) + return is; break; #endif + case IPPROTO_ICMP : - tcp = NULL; if (v == 4) { hv += ic->icmp_id; - hv += ic->icmp_seq; } - hvm = hv % fr_statesize; + hv = DOUBLE_HASH(hv); READ_ENTER(&ipf_state); - 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, NULL) && - fr_matchicmpqueryreply(v, is, ic, fin->fin_rev)) { - rev = fin->fin_rev; - if (is->is_frage[rev] != 0) - is->is_age = is->is_frage[rev]; - else if (fin->fin_rev) - is->is_age = fr_icmpacktimeout; + for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { + isp = &is->is_hnext; + if ((is->is_p != pr) || (is->is_v != v)) + continue; + is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); + if (is != NULL && + fr_matchicmpqueryreply(v, &is->is_icmp, + ic, fin->fin_rev)) { + if (fin->fin_rev) + ifq = &ips_icmpacktq; else - is->is_age = fr_icmptimeout; + ifq = &ips_icmptq; break; } - - if (is != NULL) - break; - RWLOCK_EXIT(&ipf_state); - /* - * No matching icmp state entry. Perhaps this is a - * response to another state entry. - */ - fr = fr_checkicmpmatchingstate(ip, fin); - if (fr) - return fr; + } + if (is == NULL) { + RWLOCK_EXIT(&ipf_state); + } break; + case IPPROTO_TCP : - /* - * Just plain ignore RST flag set with either FIN or SYN. - */ - if ((tcp->th_flags & TH_RST) && - ((tcp->th_flags & (TH_FIN|TH_SYN|TH_RST)) != TH_RST)) - break; case IPPROTO_UDP : - { - register u_short dport, sport; - - dport = tcp->th_dport; - sport = tcp->th_sport; - tryagain = 0; - hv += dport; + ifqp = NULL; + sport = htons(fin->fin_data[0]); hv += sport; + dport = htons(fin->fin_data[1]); + hv += dport; + oow = 0; + tryagain = 0; READ_ENTER(&ipf_state); retry_tcpudp: - hvm = 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)) { - rev = fin->fin_rev; - if ((pr == IPPROTO_TCP)) { - if (!fr_tcpstate(is, fin, ip, tcp)) - is = NULL; - } else if ((pr == IPPROTO_UDP)) { - if (is->is_frage[rev] != 0) - is->is_age = is->is_frage[rev]; - else if (fin->fin_rev) - is->is_age = fr_udpacktimeout; - else - is->is_age = fr_udptimeout; + hvm = DOUBLE_HASH(hv); + for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) { + isp = &is->is_hnext; + if ((is->is_p != pr) || (is->is_v != v)) + continue; + fin->fin_flx &= ~FI_OOW; + is = fr_matchsrcdst(fin, is, &src, &dst, tcp, FI_CMP); + if (is != NULL) { + if (pr == IPPROTO_TCP) { + if (!fr_tcpstate(fin, tcp, is)) { + oow |= fin->fin_flx & FI_OOW; + continue; + } } break; } + } if (is != NULL) { if (tryagain && - !(is->is_flags & (FI_WILDP|FI_WILDA))) { + !(is->is_flags & (SI_CLONE|SI_WILDP|SI_WILDA))) { hv += dport; hv += sport; - fr_ipsmove(isp, is, hv); + fr_ipsmove(is, hv); MUTEX_DOWNGRADE(&ipf_state); } break; } - RWLOCK_EXIT(&ipf_state); - if (!tryagain && ips_wild) { + + if (!tryagain && ips_stats.iss_wild) { hv -= dport; hv -= sport; tryagain = 1; WRITE_ENTER(&ipf_state); goto retry_tcpudp; } + fin->fin_flx |= oow; break; - } + +#if 0 + case IPPROTO_GRE : + gre = fin->fin_dp; + if (GRE_REV(gre->gr_flags) == 1) { + hv += gre->gr_call; + } + /* FALLTHROUGH */ +#endif default : - tcp = NULL; - hv %= fr_statesize; + ifqp = NULL; + hvm = DOUBLE_HASH(hv); 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)) { - rev = fin->fin_rev; - if (is->is_frage[rev] != 0) - is->is_age = is->is_frage[rev]; - else - is->is_age = fr_udptimeout; + for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) { + isp = &is->is_hnext; + if ((is->is_p != pr) || (is->is_v != v)) + continue; + is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); + if (is != NULL) { + ifq = &ips_iptq; break; } } @@ -1662,463 +2377,1013 @@ retry_tcpudp: break; } + if ((is != NULL) && ((is->is_sti.tqe_flags & TQE_RULEBASED) != 0) && + (is->is_tqehead[fin->fin_rev] != NULL)) + ifq = is->is_tqehead[fin->fin_rev]; + if (ifq != NULL && ifqp != NULL) + *ifqp = ifq; + return is; +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_updatestate */ +/* Returns: Nil */ +/* Parameters: fin(I) - pointer to packet information */ +/* is(I) - pointer to state table entry */ +/* Read Locks: ipf_state */ +/* */ +/* Updates packet and byte counters for a newly received packet. Seeds the */ +/* fragment cache with a new entry as required. */ +/* ------------------------------------------------------------------------ */ +void fr_updatestate(fin, is, ifq) +fr_info_t *fin; +ipstate_t *is; +ipftq_t *ifq; +{ + ipftqent_t *tqe; + int i, pass; + + i = (fin->fin_rev << 1) + fin->fin_out; + + /* + * For TCP packets, ifq == NULL. For all others, check if this new + * queue is different to the last one it was on and move it if so. + */ + tqe = &is->is_sti; + MUTEX_ENTER(&is->is_lock); + if ((tqe->tqe_flags & TQE_RULEBASED) != 0) + ifq = is->is_tqehead[fin->fin_rev]; + + if (ifq != NULL) + fr_movequeue(tqe, tqe->tqe_ifq, ifq); + + is->is_pkts[i]++; + is->is_bytes[i] += fin->fin_plen; + MUTEX_EXIT(&is->is_lock); + +#ifdef IPFILTER_SYNC + if (is->is_flags & IS_STATESYNC) + ipfsync_update(SMC_STATE, fin, is->is_sync); +#endif + + ATOMIC_INCL(ips_stats.iss_hits); + + fin->fin_fr = is->is_rule; + + /* + * If this packet is a fragment and the rule says to track fragments, + * then create a new fragment cache entry. + */ + pass = is->is_pass; + if ((fin->fin_flx & FI_FRAG) && FR_ISPASS(pass)) + (void) fr_newfrag(fin, pass ^ FR_KEEPSTATE); +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_checkstate */ +/* Returns: frentry_t* - NULL == search failed, */ +/* else pointer to rule for matching state */ +/* Parameters: ifp(I) - pointer to interface */ +/* passp(I) - pointer to filtering result flags */ +/* */ +/* Check if a packet is associated with an entry in the state table. */ +/* ------------------------------------------------------------------------ */ +frentry_t *fr_checkstate(fin, passp) +fr_info_t *fin; +u_32_t *passp; +{ + ipstate_t *is; + frentry_t *fr; + tcphdr_t *tcp; + ipftq_t *ifq; + u_int pass; + + if (fr_state_lock || (ips_list == NULL) || + (fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD))) + return NULL; + + is = NULL; + if ((fin->fin_flx & FI_TCPUDP) || + (fin->fin_fi.fi_p == IPPROTO_ICMP) +#ifdef USE_INET6 + || (fin->fin_fi.fi_p == IPPROTO_ICMPV6) +#endif + ) + tcp = fin->fin_dp; + else + tcp = NULL; + + /* + * Search the hash table for matching packet header info. + */ + ifq = NULL; + is = fin->fin_state; + if (is == NULL) + is = fr_stlookup(fin, tcp, &ifq); + switch (fin->fin_p) + { +#ifdef USE_INET6 + case IPPROTO_ICMPV6 : + if (is != NULL) + break; + if (fin->fin_v == 6) { + is = fr_checkicmp6matchingstate(fin); + if (is != NULL) + goto matched; + } + break; +#endif + case IPPROTO_ICMP : + if (is != NULL) + break; + /* + * No matching icmp state entry. Perhaps this is a + * response to another state entry. + */ + is = fr_checkicmpmatchingstate(fin); + if (is != NULL) + goto matched; + break; + case IPPROTO_TCP : + if (is == NULL) + break; + + if (is->is_pass & FR_NEWISN) { + if (fin->fin_out == 0) + fr_fixinisn(fin, is); + else if (fin->fin_out == 1) + fr_fixoutisn(fin, is); + } + break; + default : + if (fin->fin_rev) + ifq = &ips_udpacktq; + else + ifq = &ips_udptq; + break; + } if (is == NULL) { ATOMIC_INCL(ips_stats.iss_miss); return NULL; } - MUTEX_ENTER(&is->is_lock); - is->is_bytes += fin->fin_plen; - ips_stats.iss_hits++; - is->is_pkts++; - MUTEX_EXIT(&is->is_lock); +matched: fr = is->is_rule; - fin->fin_rule = is->is_rulen; if (fr != NULL) { - fin->fin_group = fr->fr_group; + if ((fin->fin_out == 0) && (fr->fr_nattag.ipt_num[0] != 0)) { + if (fin->fin_nattag == NULL) + return NULL; + if (fr_matchtag(&fr->fr_nattag, fin->fin_nattag) != 0) + return NULL; + } + (void) strncpy(fin->fin_group, fr->fr_group, FR_GROUPLEN); fin->fin_icode = fr->fr_icode; } - fin->fin_fr = fr; + + fin->fin_rule = is->is_rulen; pass = is->is_pass; + fr_updatestate(fin, is, ifq); + if (fin->fin_out == 1) + fin->fin_nat = is->is_nat[fin->fin_rev]; + + fin->fin_state = is; + is->is_touched = fr_ticks; + MUTEX_ENTER(&is->is_lock); + is->is_ref++; + MUTEX_EXIT(&is->is_lock); RWLOCK_EXIT(&ipf_state); - if ((fin->fin_fl & FI_FRAG) && (pass & FR_KEEPFRAG)) - ipfr_newfrag(ip, fin); -#ifndef _KERNEL - if ((tcp != NULL) && (tcp->th_flags & TCP_CLOSE)) - fr_delstate(is); -#endif + fin->fin_flx |= FI_STATE; + if ((pass & FR_LOGFIRST) != 0) + pass &= ~(FR_LOGFIRST|FR_LOG); + *passp = pass; return fr; } -/* - * Sync. state entries. If interfaces come or go or just change position, - * this is needed. - */ -void ip_statesync(ifp) +/* ------------------------------------------------------------------------ */ +/* Function: fr_fixoutisn */ +/* Returns: Nil */ +/* Parameters: fin(I) - pointer to packet information */ +/* is(I) - pointer to master state structure */ +/* */ +/* Called only for outbound packets, adjusts the sequence number and the */ +/* TCP checksum to match that change. */ +/* ------------------------------------------------------------------------ */ +static void fr_fixoutisn(fin, is) +fr_info_t *fin; +ipstate_t *is; +{ + tcphdr_t *tcp; + int rev; + u_32_t seq; + + tcp = fin->fin_dp; + rev = fin->fin_rev; + if ((is->is_flags & IS_ISNSYN) != 0) { + if (rev == 0) { + seq = ntohl(tcp->th_seq); + seq += is->is_isninc[0]; + tcp->th_seq = htonl(seq); + fix_outcksum(fin, &tcp->th_sum, is->is_sumd[0]); + } + } + if ((is->is_flags & IS_ISNACK) != 0) { + if (rev == 1) { + seq = ntohl(tcp->th_seq); + seq += is->is_isninc[1]; + tcp->th_seq = htonl(seq); + fix_outcksum(fin, &tcp->th_sum, is->is_sumd[1]); + } + } +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_fixinisn */ +/* Returns: Nil */ +/* Parameters: fin(I) - pointer to packet information */ +/* is(I) - pointer to master state structure */ +/* */ +/* Called only for inbound packets, adjusts the acknowledge number and the */ +/* TCP checksum to match that change. */ +/* ------------------------------------------------------------------------ */ +static void fr_fixinisn(fin, is) +fr_info_t *fin; +ipstate_t *is; +{ + tcphdr_t *tcp; + int rev; + u_32_t ack; + + tcp = fin->fin_dp; + rev = fin->fin_rev; + if ((is->is_flags & IS_ISNSYN) != 0) { + if (rev == 1) { + ack = ntohl(tcp->th_ack); + ack -= is->is_isninc[0]; + tcp->th_ack = htonl(ack); + fix_incksum(fin, &tcp->th_sum, is->is_sumd[0]); + } + } + if ((is->is_flags & IS_ISNACK) != 0) { + if (rev == 0) { + ack = ntohl(tcp->th_ack); + ack -= is->is_isninc[1]; + tcp->th_ack = htonl(ack); + fix_incksum(fin, &tcp->th_sum, is->is_sumd[1]); + } + } +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_statesync */ +/* Returns: Nil */ +/* Parameters: ifp(I) - pointer to interface */ +/* */ +/* Walk through all state entries and if an interface pointer match is */ +/* found then look it up again, based on its name in case the pointer has */ +/* changed since last time. */ +/* */ +/* If ifp is passed in as being non-null then we are only doing updates for */ +/* existing, matching, uses of it. */ +/* ------------------------------------------------------------------------ */ +void fr_statesync(ifp) void *ifp; { - register ipstate_t *is; + ipstate_t *is; int i; + if (fr_running <= 0) + return; + WRITE_ENTER(&ipf_state); + + if (fr_running <= 0) { + RWLOCK_EXIT(&ipf_state); + return; + } + for (is = ips_list; is; is = is->is_next) { + /* + * Look up all the interface names in the state entry. + */ for (i = 0; i < 4; i++) { - if (is->is_ifp[i] == ifp) { - is->is_ifp[i] = GETUNIT(is->is_ifname[i], - is->is_v); - if (!is->is_ifp[i]) - is->is_ifp[i] = (void *)-1; - } + if (ifp == NULL || ifp == is->is_ifp[i]) + is->is_ifp[i] = fr_resolvenic(is->is_ifname[i], + is->is_v); } } RWLOCK_EXIT(&ipf_state); } -/* - * Must always be called with fr_ipfstate held as a write lock. - */ -static void fr_delstate(is) +/* ------------------------------------------------------------------------ */ +/* Function: fr_delstate */ +/* Returns: Nil */ +/* Parameters: is(I) - pointer to state structure to delete */ +/* why(I) - if not 0, log reason why it was deleted */ +/* Write Locks: ipf_state */ +/* */ +/* Deletes a state entry from the enumerated list as well as the hash table */ +/* and timeout queue lists. Make adjustments to hash table statistics and */ +/* global counters as required. */ +/* ------------------------------------------------------------------------ */ +static void fr_delstate(is, why) ipstate_t *is; +int why; { - 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--; - if (is->is_me) - *is->is_me = NULL; + ASSERT(rw_read_locked(&ipf_state.ipf_lk) == 0); - fr = is->is_rule; - if (fr != NULL) { - fr->fr_ref--; - if (fr->fr_ref == 0) { - KFREE(fr); + /* + * Since we want to delete this, remove it from the state table, + * where it can be found & used, first. + */ + if (is->is_pnext != NULL) { + *is->is_pnext = is->is_next; + + if (is->is_next != NULL) + is->is_next->is_pnext = is->is_pnext; + + is->is_pnext = NULL; + is->is_next = NULL; + } + + if (is->is_phnext != NULL) { + *is->is_phnext = is->is_hnext; + if (is->is_hnext != NULL) + is->is_hnext->is_phnext = is->is_phnext; + if (ips_table[is->is_hv] == NULL) + ips_stats.iss_inuse--; + ips_stats.iss_bucketlen[is->is_hv]--; + + is->is_phnext = NULL; + is->is_hnext = NULL; + } + + /* + * Because ips_stats.iss_wild is a count of entries in the state + * table that have wildcard flags set, only decerement it once + * and do it here. + */ + if (is->is_flags & (SI_WILDP|SI_WILDA)) { + if (!(is->is_flags & SI_CLONED)) { + ATOMIC_DECL(ips_stats.iss_wild); } + is->is_flags &= ~(SI_WILDP|SI_WILDA); } -#ifdef _KERNEL - MUTEX_DESTROY(&is->is_lock); + + /* + * Next, remove it from the timeout queue it is in. + */ + fr_deletequeueentry(&is->is_sti); + + if (is->is_me != NULL) { + *is->is_me = NULL; + is->is_me = NULL; + } + + /* + * If it is still in use by something else, do not go any further, + * but note that at this point it is now an orphan. + */ + is->is_ref--; + if (is->is_ref > 0) + return; + + if (is->is_tqehead[0] != NULL) { + if (fr_deletetimeoutqueue(is->is_tqehead[0]) == 0) + fr_freetimeoutqueue(is->is_tqehead[0]); + } + if (is->is_tqehead[1] != NULL) { + if (fr_deletetimeoutqueue(is->is_tqehead[1]) == 0) + fr_freetimeoutqueue(is->is_tqehead[1]); + } + +#ifdef IPFILTER_SYNC + if (is->is_sync) + ipfsync_del(is->is_sync); +#endif +#ifdef IPFILTER_SCAN + (void) ipsc_detachis(is); #endif - KFREE(is); - ips_num--; -} + if (ipstate_logging != 0 && why != 0) + ipstate_log(is, why); -/* - * Free memory in use by all state info. kept. - */ -void fr_stateunload() -{ - register ipstate_t *is; + if (is->is_rule != NULL) { + is->is_rule->fr_statecnt--; + (void)fr_derefrule(&is->is_rule); + } - WRITE_ENTER(&ipf_state); - while ((is = ips_list)) - fr_delstate(is); - ips_stats.iss_inuse = 0; - ips_num = 0; - RWLOCK_EXIT(&ipf_state); - if (ips_table) - KFREES(ips_table, fr_statesize * sizeof(ipstate_t *)); - ips_table = NULL; + MUTEX_DESTROY(&is->is_lock); + KFREE(is); + ips_num--; } -/* - * Slowly expire held state for thingslike UDP and ICMP. Timeouts are set - * in expectation of this being called twice per second. - */ +/* ------------------------------------------------------------------------ */ +/* Function: fr_timeoutstate */ +/* Returns: Nil */ +/* Parameters: Nil */ +/* */ +/* Slowly expire held state for thingslike UDP and ICMP. The algorithm */ +/* used here is to keep the queue sorted with the oldest things at the top */ +/* and the youngest at the bottom. So if the top one doesn't need to be */ +/* expired then neither will any under it. */ +/* ------------------------------------------------------------------------ */ void fr_timeoutstate() { - register ipstate_t *is, **isp; -#if defined(_KERNEL) && !SOLARIS + ipftq_t *ifq, *ifqnext; + ipftqent_t *tqe, *tqn; + ipstate_t *is; +#if defined(USE_SPL) && defined(_KERNEL) int s; #endif SPL_NET(s); WRITE_ENTER(&ipf_state); - for (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; + for (ifq = ips_tqtqb; ifq != NULL; ifq = ifq->ifq_next) + for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { + if (tqe->tqe_die > fr_ticks) + break; + tqn = tqe->tqe_next; + is = tqe->tqe_parent; + fr_delstate(is, ISL_EXPIRE); + } + + for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) { + ifqnext = ifq->ifq_next; + + for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { + if (tqe->tqe_die > fr_ticks) + break; + tqn = tqe->tqe_next; + is = tqe->tqe_parent; + fr_delstate(is, ISL_EXPIRE); + } + } + + for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) { + ifqnext = ifq->ifq_next; + + if (((ifq->ifq_flags & IFQF_DELETE) != 0) && + (ifq->ifq_ref == 0)) { + fr_freetimeoutqueue(ifq); + } + } + if (fr_state_doflush) { (void) fr_state_flush(2, 0); fr_state_doflush = 0; } + RWLOCK_EXIT(&ipf_state); SPL_X(s); } -/* - * 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 - * - */ -int fr_tcp_age(age, state, fin, dir, fsm) -u_long *age; -u_char *state; -fr_info_t *fin; -int dir, fsm; +/* ------------------------------------------------------------------------ */ +/* Function: fr_state_flush */ +/* Returns: int - 0 == success, -1 == failure */ +/* Parameters: Nil */ +/* Write Locks: ipf_state */ +/* */ +/* Flush state tables. Three actions currently defined: */ +/* which == 0 : flush all state table entries */ +/* which == 1 : flush TCP connections which have started to close but are */ +/* stuck for some reason. */ +/* which == 2 : flush TCP connections which have been idle for a long time, */ +/* starting at > 4 days idle and working back in successive half-*/ +/* days to at most 12 hours old. If this fails to free enough */ +/* slots then work backwards in half hour slots to 30 minutes. */ +/* If that too fails, then work backwards in 30 second intervals */ +/* for the last 30 minutes to at worst 30 seconds idle. */ +/* ------------------------------------------------------------------------ */ +static int fr_state_flush(which, proto) +int which, proto; { - tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp; - u_char flags = tcp->th_flags; - int dlen, ostate; - u_long newage; + ipftq_t *ifq, *ifqnext; + ipftqent_t *tqe, *tqn; + ipstate_t *is, **isp; + int delete, removed; + long try, maxtick; + u_long interval; +#if defined(_KERNEL) && !defined(MENTAT) && defined(USE_SPL) + int s; +#endif - ostate = state[1 - dir]; + removed = 0; - dlen = fin->fin_plen - fin->fin_hlen - (tcp->th_off << 2); + SPL_NET(s); + for (isp = &ips_list; ((is = *isp) != NULL); ) { + delete = 0; - 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; + if ((proto != 0) && (is->is_v != proto)) { + isp = &is->is_next; + continue; } - return 0; + + switch (which) + { + case 0 : + delete = 1; + break; + case 1 : + case 2 : + if (is->is_p != IPPROTO_TCP) + break; + if ((is->is_state[0] != IPF_TCPS_ESTABLISHED) || + (is->is_state[1] != IPF_TCPS_ESTABLISHED)) + delete = 1; + break; + } + + if (delete) { + if (is->is_p == IPPROTO_TCP) + ips_stats.iss_fin++; + else + ips_stats.iss_expire++; + fr_delstate(is, ISL_FLUSH); + removed++; + } else + isp = &is->is_next; } - newage = 0; + if (which != 2) { + SPL_X(s); + return removed; + } - 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; - newage = fr_tcptimeout; - } else if ((flags & TH_OPENING) == TH_SYN) { - /* 'dir' sent S, CLOSED -> SYN_SENT */ - state[dir] = TCPS_SYN_SENT; - newage = fr_tcptimeout; - } - - /* - * It is apparently possible that a hosts sends two syncs - * before the remote party is able to respond with a SA. In - * such a case the remote server sometimes ACK's the second - * sync, and then responds with a SA. The following code - * is used to prevent this ack from being blocked. - * - * We do not reset the timeout here to fr_tcptimeout because - * a connection connect timeout does not renew after every - * packet that is sent. We need to set newage to something - * to indicate the packet has passed the check for its flags - * being valid in the TCP FSM. - */ - else if ((ostate == TCPS_SYN_SENT) && - ((flags & (TH_FIN|TH_SYN|TH_RST|TH_ACK)) == TH_ACK)) { - newage = *age; + /* + * Asked to remove inactive entries because the table is full, try + * again, 3 times, if first attempt failed with a different criteria + * each time. The order tried in must be in decreasing age. + * Another alternative is to implement random drop and drop N entries + * at random until N have been freed up. + */ + if (fr_ticks - ips_last_force_flush < IPF_TTLVAL(5)) + goto force_flush_skipped; + ips_last_force_flush = fr_ticks; + + if (fr_ticks > IPF_TTLVAL(43200)) + interval = IPF_TTLVAL(43200); + else if (fr_ticks > IPF_TTLVAL(1800)) + interval = IPF_TTLVAL(1800); + else if (fr_ticks > IPF_TTLVAL(30)) + interval = IPF_TTLVAL(30); + else + interval = IPF_TTLVAL(10); + try = fr_ticks - (fr_ticks - interval); + if (try < 0) + goto force_flush_skipped; + + while (removed == 0) { + maxtick = fr_ticks - interval; + if (maxtick < 0) + break; + + while (try < maxtick) { + for (ifq = ips_tqtqb; ifq != NULL; + ifq = ifq->ifq_next) { + for (tqn = ifq->ifq_head; + ((tqe = tqn) != NULL); ) { + if (tqe->tqe_die > try) + break; + tqn = tqe->tqe_next; + is = tqe->tqe_parent; + fr_delstate(is, ISL_EXPIRE); + removed++; + } + } + + for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) { + ifqnext = ifq->ifq_next; + + for (tqn = ifq->ifq_head; + ((tqe = tqn) != NULL); ) { + if (tqe->tqe_die > try) + break; + tqn = tqe->tqe_next; + is = tqe->tqe_parent; + fr_delstate(is, ISL_EXPIRE); + removed++; + } + } + if (try + interval > maxtick) + break; + try += interval; } - /* - * 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, however, use a - * lower time-out so the state disappears quickly if - * the other side does not pick it up. - */ - else if (!fsm && - (flags & (TH_FIN|TH_SYN|TH_RST|TH_ACK)) == TH_ACK) { - /* we saw an A, guess 'dir' is in ESTABLISHED mode */ - if (ostate == TCPS_CLOSED) { - state[dir] = TCPS_ESTABLISHED; - newage = fr_tcptimeout; - } else if (ostate == TCPS_ESTABLISHED) { - state[dir] = TCPS_ESTABLISHED; - newage = fr_tcpidletimeout; + if (removed == 0) { + if (interval == IPF_TTLVAL(43200)) { + interval = IPF_TTLVAL(1800); + } else if (interval == IPF_TTLVAL(1800)) { + interval = IPF_TTLVAL(30); + } else if (interval == IPF_TTLVAL(30)) { + interval = IPF_TTLVAL(10); + } else { + break; } } - /* - * 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; + } +force_flush_skipped: + SPL_X(s); + return removed; +} - case TCPS_LISTEN: /* 1 */ - /* NOT USED */ - break; - case TCPS_SYN_SENT: /* 2 */ - if ((flags & ~(TH_ECN|TH_CWR)) == TH_SYN) { - /* - * A retransmitted SYN packet. We do not reset the - * timeout here to fr_tcptimeout because a connection - * connect timeout does not renew after every packet - * that is sent. We need to set newage to something - * to indicate the packet has passed the check for its - * flags being valid in the TCP FSM. - */ - newage = *age; - } else 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; - newage = 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; - newage = 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; - newage = 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; - newage = fr_tcpidletimeout; - } else if ((flags & ~(TH_ECN|TH_CWR)) == TH_OPENING) { +/* ------------------------------------------------------------------------ */ +/* Function: fr_tcp_age */ +/* Returns: int - 1 == state transition made, 0 == no change (rejected) */ +/* Parameters: tq(I) - pointer to timeout queue information */ +/* fin(I) - pointer to packet information */ +/* tqtab(I) - TCP timeout queue table this is in */ +/* flags(I) - flags from state/NAT entry */ +/* */ +/* Rewritten by Arjan de Vet <Arjan.deVet@adv.iae.nl>, 2000-07-29: */ +/* */ +/* - (try to) base state transitions on real evidence only, */ +/* i.e. packets that are sent and have been received by ipfilter; */ +/* diagram 18.12 of TCP/IP volume 1 by W. Richard Stevens was used. */ +/* */ +/* - deal with half-closed connections correctly; */ +/* */ +/* - store the state of the source in state[0] such that ipfstat */ +/* displays the state as source/dest instead of dest/source; the calls */ +/* to fr_tcp_age have been changed accordingly. */ +/* */ +/* Internal Parameters: */ +/* */ +/* state[0] = state of source (host that initiated connection) */ +/* state[1] = state of dest (host that accepted the connection) */ +/* */ +/* dir == 0 : a packet from source to dest */ +/* dir == 1 : a packet from dest to source */ +/* */ +/* Locking: it is assumed that the parent of the tqe structure is locked. */ +/* ------------------------------------------------------------------------ */ +int fr_tcp_age(tqe, fin, tqtab, flags) +ipftqent_t *tqe; +fr_info_t *fin; +ipftq_t *tqtab; +int flags; +{ + int dlen, ostate, nstate, rval, dir; + u_char tcpflags; + tcphdr_t *tcp; + + tcp = fin->fin_dp; + + rval = 0; + dir = fin->fin_rev; + tcpflags = tcp->th_flags; + dlen = fin->fin_plen - fin->fin_hlen - (TCP_OFF(tcp) << 2); + + if (tcpflags & TH_RST) { + if (!(tcpflags & TH_PUSH) && !dlen) + nstate = IPF_TCPS_CLOSED; + else + nstate = IPF_TCPS_CLOSE_WAIT; + rval = 1; + } else { + ostate = tqe->tqe_state[1 - dir]; + nstate = tqe->tqe_state[dir]; + + switch (nstate) + { + case IPF_TCPS_CLOSED: /* 0 */ + if ((tcpflags & TH_OPENING) == TH_OPENING) { + /* + * 'dir' received an S and sends SA in + * response, CLOSED -> SYN_RECEIVED + */ + nstate = IPF_TCPS_SYN_RECEIVED; + rval = 1; + } else if ((tcpflags & TH_OPENING) == TH_SYN) { + /* 'dir' sent S, CLOSED -> SYN_SENT */ + nstate = IPF_TCPS_SYN_SENT; + rval = 1; + } /* - * We see an SA from 'dir' which is already in - * SYN_RECEIVED state. + * 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 */ - newage = fr_tcptimeout; - } else if (flags & TH_FIN) { + if (((flags & IS_TCPFSM) == 0) && + ((tcpflags & TH_ACKMASK) == TH_ACK)) { + /* + * we saw an A, guess 'dir' is in ESTABLISHED + * mode + */ + switch (ostate) + { + case IPF_TCPS_CLOSED : + case IPF_TCPS_SYN_RECEIVED : + nstate = IPF_TCPS_HALF_ESTAB; + rval = 1; + break; + case IPF_TCPS_HALF_ESTAB : + case IPF_TCPS_ESTABLISHED : + nstate = IPF_TCPS_ESTABLISHED; + rval = 1; + break; + default : + break; + } + } /* - * 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 + * 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 */ - state[dir] = TCPS_FIN_WAIT_1; - newage = fr_tcpidletimeout; - } - break; + 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; - newage = fr_tcphalfclosed; - } else if (flags & TH_ACK) { - /* an ACK, should we exclude other flags here? */ - if (ostate == TCPS_FIN_WAIT_1) { + case IPF_TCPS_LISTEN: /* 1 */ + /* NOT USED */ + break; + + case IPF_TCPS_SYN_SENT: /* 2 */ + if ((tcpflags & ~(TH_ECN|TH_CWR)) == TH_SYN) { /* - * 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 + * A retransmitted SYN packet. We do not reset + * the timeout here to fr_tcptimeout because a + * connection connect timeout does not renew + * after every packet that is sent. We need to + * set rval so as to indicate the packet has + * passed the check for its flags being valid + * in the TCP FSM. Setting rval to 2 has the + * result of not resetting the timeout. */ - state[dir] = TCPS_CLOSE_WAIT; - newage = fr_tcphalfclosed; - } else if (ostate < TCPS_CLOSE_WAIT) + rval = 2; + } else if ((tcpflags & (TH_SYN|TH_FIN|TH_ACK)) == + TH_ACK) { /* - * Still a fully established connection, - * reset timeout + * 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 */ - newage = fr_tcpidletimeout; - } - break; + nstate = IPF_TCPS_ESTABLISHED; + rval = 1; + } else if (tcpflags & TH_FIN) { + /* + * we see an F from 'dir' which is in SYN_SENT + * state and wants to close its side of the + * connection; SYN_SENT -> FIN_WAIT_1 + */ + nstate = IPF_TCPS_FIN_WAIT_1; + rval = 1; + } else if ((tcpflags & TH_OPENING) == TH_OPENING) { + /* + * we see an SA from 'dir' which is already in + * SYN_SENT state, this means we have a + * simultaneous open; SYN_SENT -> SYN_RECEIVED + */ + nstate = IPF_TCPS_SYN_RECEIVED; + rval = 1; + } + break; - case TCPS_CLOSE_WAIT: /* 5 */ - if (flags & TH_FIN) { - /* - * Application closed and 'dir' sent a FIN, we're now - * going into LAST_ACK state - */ - newage = 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 - */ - newage = fr_tcphalfclosed; - } - break; + case IPF_TCPS_SYN_RECEIVED: /* 3 */ + if ((tcpflags & (TH_SYN|TH_FIN|TH_ACK)) == TH_ACK) { + /* + * we see an A from 'dir' which was in + * SYN_RECEIVED state so it must now be in + * established state, SYN_RECEIVED -> + * ESTABLISHED + */ + nstate = IPF_TCPS_ESTABLISHED; + rval = 1; + } else if ((tcpflags & ~(TH_ECN|TH_CWR)) == + TH_OPENING) { + /* + * We see an SA from 'dir' which is already in + * SYN_RECEIVED state. + */ + rval = 2; + } else if (tcpflags & TH_FIN) { + /* + * we see an F from 'dir' which is in + * SYN_RECEIVED state and wants to close its + * side of the connection; SYN_RECEIVED -> + * FIN_WAIT_1 + */ + nstate = IPF_TCPS_FIN_WAIT_1; + rval = 1; + } + break; - case 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; - newage = 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 - */ - newage = fr_tcphalfclosed; - break; + case IPF_TCPS_HALF_ESTAB: /* 4 */ + if (ostate >= IPF_TCPS_HALF_ESTAB) { + if ((tcpflags & TH_ACKMASK) == TH_ACK) { + nstate = IPF_TCPS_ESTABLISHED; + rval = 1; + } + } + + break; - case TCPS_CLOSING: /* 7 */ - /* NOT USED */ - break; + case IPF_TCPS_ESTABLISHED: /* 5 */ + rval = 1; + if (tcpflags & TH_FIN) { + /* + * 'dir' closed its side of the connection; + * this gives us a half-closed connection; + * ESTABLISHED -> FIN_WAIT_1 + */ + nstate = IPF_TCPS_FIN_WAIT_1; + } else if (tcpflags & TH_ACK) { + /* + * an ACK, should we exclude other flags here? + */ + if (ostate == IPF_TCPS_FIN_WAIT_1) { + /* + * We know the other side did an active + * close, so we are ACKing the recvd + * FIN packet (does the window matching + * code guarantee this?) and go into + * CLOSE_WAIT state; this gives us a + * half-closed connection + */ + nstate = IPF_TCPS_CLOSE_WAIT; + } else if (ostate < IPF_TCPS_CLOSE_WAIT) { + /* + * still a fully established + * connection reset timeout + */ + nstate = IPF_TCPS_ESTABLISHED; + } + } + break; - case TCPS_LAST_ACK: /* 8 */ - if (flags & TH_ACK) { - if ((flags & TH_PUSH) || dlen) + case IPF_TCPS_CLOSE_WAIT: /* 6 */ + rval = 1; + if (tcpflags & TH_FIN) { /* - * There is still data to be delivered, reset - * timeout + * application closed and 'dir' sent a FIN, + * we're now going into LAST_ACK state */ - newage = fr_tcplastack; - else - newage = *age; - } - /* - * 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; + nstate = IPF_TCPS_LAST_ACK; + } else { + /* + * we remain in CLOSE_WAIT because the other + * side has closed already and we did not + * close our side yet; reset timeout + */ + nstate = IPF_TCPS_CLOSE_WAIT; + } + break; - case TCPS_FIN_WAIT_2: /* 9 */ - /* NOT USED */ - break; + case IPF_TCPS_FIN_WAIT_1: /* 7 */ + rval = 1; + if ((tcpflags & TH_ACK) && + ostate > IPF_TCPS_CLOSE_WAIT) { + /* + * if the other side is not active anymore + * it has sent us a FIN packet that we are + * ack'ing now with an ACK; this means both + * sides have now closed the connection and + * we go into TIME_WAIT + */ + /* + * XXX: how do we know we really are ACKing + * the FIN packet here? does the window code + * guarantee that? + */ + nstate = IPF_TCPS_TIME_WAIT; + } else { + /* + * we closed our side of the connection + * already but the other side is still active + * (ESTABLISHED/CLOSE_WAIT); continue with + * this half-closed connection + */ + nstate = IPF_TCPS_FIN_WAIT_1; + } + break; - case TCPS_TIME_WAIT: /* 10 */ - newage = fr_tcptimeout; /* default 4 mins */ - /* we're in 2MSL timeout now */ - break; + case IPF_TCPS_CLOSING: /* 8 */ + /* NOT USED */ + break; + + case IPF_TCPS_LAST_ACK: /* 9 */ + if (tcpflags & TH_ACK) { + if ((tcpflags & TH_PUSH) || dlen) + /* + * there is still data to be delivered, + * reset timeout + */ + rval = 1; + else + rval = 2; + } + /* + * we cannot detect when we go out of LAST_ACK state to + * CLOSED because that is based on the reception of ACK + * packets; ipfilter can only detect that a packet + * has been sent by a host + */ + break; + + case IPF_TCPS_FIN_WAIT_2: /* 10 */ + rval = 1; + if ((tcpflags & TH_OPENING) == TH_OPENING) + nstate = IPF_TCPS_SYN_RECEIVED; + else if (tcpflags & TH_SYN) + nstate = IPF_TCPS_SYN_SENT; + break; + + case IPF_TCPS_TIME_WAIT: /* 11 */ + /* we're in 2MSL timeout now */ + rval = 1; + break; + + default : +#if defined(_KERNEL) +# if SOLARIS + cmn_err(CE_NOTE, + "tcp %lx flags %x si %lx nstate %d ostate %d\n", + (u_long)tcp, tcpflags, (u_long)tqe, + nstate, ostate); +# else + printf("tcp %lx flags %x si %lx nstate %d ostate %d\n", + (u_long)tcp, tcpflags, (u_long)tqe, + nstate, ostate); +# endif +# ifdef DIAGNOSTIC + panic("invalid TCP state"); +# endif +#else + abort(); +#endif + break; + } } - if (newage != 0) { - *age = newage; - return 0; + /* + * If rval == 2 then do not update the queue position, but treat the + * packet as being ok. + */ + if (rval == 2) + rval = 1; + else if (rval == 1) { + tqe->tqe_state[dir] = nstate; + if ((tqe->tqe_flags & TQE_RULEBASED) == 0) + fr_movequeue(tqe, tqe->tqe_ifq, tqtab + nstate); } - return -1; + + return rval; } -#ifdef IPFILTER_LOG +/* ------------------------------------------------------------------------ */ +/* Function: ipstate_log */ +/* Returns: Nil */ +/* Parameters: is(I) - pointer to state structure */ +/* type(I) - type of log entry to create */ +/* */ +/* Creates a state table log entry using the state structure and type info. */ +/* passed in. Log packet/byte counts, source/destination address and other */ +/* protocol specific information. */ +/* ------------------------------------------------------------------------ */ void ipstate_log(is, type) struct ipstate *is; u_int type; { +#ifdef IPFILTER_LOG struct ipslog ipsl; - void *items[1]; size_t sizes[1]; + void *items[1]; int types[1]; + /* + * Copy information out of the ipstate_t structure and into the + * structure used for logging. + */ ipsl.isl_type = type; - ipsl.isl_pkts = is->is_pkts + is->is_icmppkts; - ipsl.isl_bytes = is->is_bytes; + ipsl.isl_pkts[0] = is->is_pkts[0] + is->is_icmppkts[0]; + ipsl.isl_bytes[0] = is->is_bytes[0]; + ipsl.isl_pkts[1] = is->is_pkts[1] + is->is_icmppkts[1]; + ipsl.isl_bytes[1] = is->is_bytes[1]; + ipsl.isl_pkts[2] = is->is_pkts[2] + is->is_icmppkts[2]; + ipsl.isl_bytes[2] = is->is_bytes[2]; + ipsl.isl_pkts[3] = is->is_pkts[3] + is->is_icmppkts[3]; + ipsl.isl_bytes[3] = is->is_bytes[3]; ipsl.isl_src = is->is_src; ipsl.isl_dst = is->is_dst; ipsl.isl_p = is->is_p; ipsl.isl_v = is->is_v; ipsl.isl_flags = is->is_flags; + ipsl.isl_tag = is->is_tag; ipsl.isl_rulen = is->is_rulen; - ipsl.isl_group = is->is_group; + (void) strncpy(ipsl.isl_group, is->is_group, FR_GROUPLEN); + if (ipsl.isl_p == IPPROTO_TCP || ipsl.isl_p == IPPROTO_UDP) { ipsl.isl_sport = is->is_sport; ipsl.isl_dport = is->is_dport; @@ -2127,13 +3392,14 @@ u_int type; ipsl.isl_state[1] = is->is_state[1]; } } else if (ipsl.isl_p == IPPROTO_ICMP) { - ipsl.isl_itype = is->is_icmp.ics_type; + ipsl.isl_itype = is->is_icmp.ici_type; } else if (ipsl.isl_p == IPPROTO_ICMPV6) { - ipsl.isl_itype = is->is_icmp.ics_type; + ipsl.isl_itype = is->is_icmp.ici_type; } else { ipsl.isl_ps.isl_filler[0] = 0; ipsl.isl_ps.isl_filler[1] = 0; } + items[0] = &ipsl; sizes[0] = sizeof(ipsl); types[0] = 0; @@ -2143,26 +3409,35 @@ u_int type; } else { ATOMIC_INCL(ips_stats.iss_logfail); } -} #endif +} #ifdef USE_INET6 -frentry_t *fr_checkicmp6matchingstate(ip, fin) -ip6_t *ip; +/* ------------------------------------------------------------------------ */ +/* Function: fr_checkicmp6matchingstate */ +/* Returns: ipstate_t* - NULL == no match found, */ +/* else pointer to matching state entry */ +/* Parameters: fin(I) - pointer to packet information */ +/* Locks: NULL == no locks, else Read Lock on ipf_state */ +/* */ +/* If we've got an ICMPv6 error message, using the information stored in */ +/* the ICMPv6 packet, look for a matching state table entry. */ +/* ------------------------------------------------------------------------ */ +static ipstate_t *fr_checkicmp6matchingstate(fin) fr_info_t *fin; { - register ipstate_t *is, **isp; - register u_short sport, dport; - register u_char pr; - struct icmp6_hdr *ic, *oic; - union i6addr dst, src; + struct icmp6_hdr *ic6, *oic; + int type, backward, i; + ipstate_t *is, **isp; + u_short sport, dport; + i6addr_t dst, src; u_short savelen; + icmpinfo_t *ic; fr_info_t ofin; tcphdr_t *tcp; - frentry_t *fr; - ip6_t *oip; - int type; + ip6_t *oip6; + u_char pr; u_int hv; /* @@ -2172,8 +3447,9 @@ fr_info_t *fin; */ if ((fin->fin_v != 6) || (fin->fin_plen < ICMP6ERR_MINPKTLEN)) return NULL; - ic = (struct icmp6_hdr *)fin->fin_dp; - type = ic->icmp6_type; + + ic6 = fin->fin_dp; + type = ic6->icmp6_type; /* * If it's not an error type, then return */ @@ -2181,22 +3457,17 @@ fr_info_t *fin; (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_TCP) && (oip->ip6_nxt != IPPROTO_UDP) && - (oip->ip6_nxt != IPPROTO_ICMPV6)) + oip6 = (ip6_t *)((char *)ic6 + ICMPERR_ICMPHLEN); + if (fin->fin_plen < sizeof(*oip6)) return NULL; - bzero((char *)&ofin, sizeof(ofin)); - ofin.fin_out = !fin->fin_out; - ofin.fin_ifp = fin->fin_ifp; - ofin.fin_mp = NULL; + bcopy((char *)fin, (char *)&ofin, sizeof(fin)); ofin.fin_v = 6; -#if SOLARIS - ofin.fin_qfm = NULL; -#endif + ofin.fin_ifp = fin->fin_ifp; + ofin.fin_out = !fin->fin_out; + ofin.fin_m = NULL; /* if dereferenced, panic XXX */ + ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ + /* * We make a fin entry to be able to feed it to * matchsrcdst. Note that not all fields are necessary @@ -2204,16 +3475,20 @@ fr_info_t *fin; * 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 + * watch out here, as ip is in host order and oip6 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; - fr_makefrip(sizeof(*oip), (ip_t *)oip, &ofin); - oip->ip6_plen = savelen; - - if (oip->ip6_nxt == IPPROTO_ICMPV6) { - oic = (struct icmp6_hdr *)(oip + 1); + savelen = oip6->ip6_plen; + oip6->ip6_plen = fin->fin_dlen - ICMPERR_ICMPHLEN; + ofin.fin_flx = FI_NOCKSUM; + ofin.fin_ip = (ip_t *)oip6; + ofin.fin_plen = oip6->ip6_plen; + (void) fr_makefrip(sizeof(*oip6), (ip_t *)oip6, &ofin); + ofin.fin_flx &= ~(FI_BAD|FI_SHORT); + oip6->ip6_plen = savelen; + + if (oip6->ip6_nxt == IPPROTO_ICMPV6) { + oic = (struct icmp6_hdr *)(oip6 + 1); /* * an ICMP error can only be generated as a result of an * ICMP query, not as the response on an ICMP error @@ -2227,61 +3502,71 @@ fr_info_t *fin; /* * perform a lookup of the ICMP packet in the state table */ - hv = (pr = oip->ip6_nxt); - src.in6 = oip->ip6_src; + hv = (pr = oip6->ip6_nxt); + src.in6 = oip6->ip6_src; hv += src.in4.s_addr; - dst.in6 = oip->ip6_dst; + dst.in6 = oip6->ip6_dst; hv += dst.in4.s_addr; hv += oic->icmp6_id; hv += oic->icmp6_seq; - hv %= fr_statesize; + hv = DOUBLE_HASH(hv); READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_hnext) + for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { + ic = &is->is_icmp; + 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)) { + !(is->is_pass & FR_NOICMPERR) && + (oic->icmp6_id == ic->ici_id) && + (oic->icmp6_seq == ic->ici_seq) && + (is = fr_matchsrcdst(&ofin, is, &src, + &dst, NULL, FI_ICMPCMP))) { /* * in the state table ICMP query's are stored * with the type of the corresponding ICMP * response. Correct here */ - if (((is->is_type == ICMP6_ECHO_REPLY) && + if (((ic->ici_type == ICMP6_ECHO_REPLY) && (oic->icmp6_type == ICMP6_ECHO_REQUEST)) || - (is->is_type - 1 == oic->icmp6_type )) { + (ic->ici_type - 1 == oic->icmp6_type )) { ips_stats.iss_hits++; - is->is_pkts++; - is->is_bytes += fin->fin_plen; - return is->is_rule; + backward = IP6_NEQ(&is->is_dst, &src); + fin->fin_rev = !backward; + i = (backward << 1) + fin->fin_out; + is->is_icmppkts[i]++; + return is; } } + } RWLOCK_EXIT(&ipf_state); - return NULL; } - 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; + hv = (pr = oip6->ip6_nxt); + src.in6 = oip6->ip6_src; + hv += src.i6[0]; hv += src.i6[1]; hv += src.i6[2]; hv += src.i6[3]; - dst.in6 = oip->ip6_dst; - hv += dst.in4.s_addr; + dst.in6 = oip6->ip6_dst; + hv += dst.i6[0]; hv += dst.i6[1]; hv += dst.i6[2]; hv += dst.i6[3]; - hv += dport; - hv += sport; - hv %= fr_statesize; + + if ((oip6->ip6_nxt == IPPROTO_TCP) || (oip6->ip6_nxt == IPPROTO_UDP)) { + tcp = (tcphdr_t *)(oip6 + 1); + dport = tcp->th_dport; + sport = tcp->th_sport; + hv += dport; + hv += sport; + } else + tcp = NULL; + hv = DOUBLE_HASH(hv); READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; (is = *isp); isp = &is->is_hnext) { + for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { + isp = &is->is_hnext; /* * Only allow this icmp though if the * encapsulated packet was allowed through the @@ -2289,22 +3574,229 @@ fr_info_t *fin; * 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; + if ((is->is_p != pr) || (is->is_v != 6) || + (is->is_pass & FR_NOICMPERR)) + continue; + is = fr_matchsrcdst(&ofin, is, &src, &dst, tcp, FI_ICMPCMP); + if (is != NULL) { ips_stats.iss_hits++; - is->is_pkts++; - is->is_bytes += fin->fin_plen; + backward = IP6_NEQ(&is->is_dst, &src); + fin->fin_rev = !backward; + i = (backward << 1) + fin->fin_out; + is->is_icmppkts[i]++; /* * we deliberately do not touch the timeouts * for the accompanying state table entry. * It remains to be seen if that is correct. XXX */ - RWLOCK_EXIT(&ipf_state); - return fr; + return is; } } RWLOCK_EXIT(&ipf_state); return NULL; } #endif + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_sttab_init */ +/* Returns: Nil */ +/* Parameters: tqp(I) - pointer to an array of timeout queues for TCP */ +/* */ +/* Initialise the array of timeout queues for TCP. */ +/* ------------------------------------------------------------------------ */ +void fr_sttab_init(tqp) +ipftq_t *tqp; +{ + int i; + + for (i = IPF_TCP_NSTATES - 1; i >= 0; i--) { + tqp[i].ifq_ttl = 0; + tqp[i].ifq_ref = 1; + tqp[i].ifq_head = NULL; + tqp[i].ifq_tail = &tqp[i].ifq_head; + tqp[i].ifq_next = tqp + i + 1; + MUTEX_INIT(&tqp[i].ifq_lock, "ipftq tcp tab"); + } + tqp[IPF_TCP_NSTATES - 1].ifq_next = NULL; + tqp[IPF_TCPS_CLOSED].ifq_ttl = fr_tcpclosed; + tqp[IPF_TCPS_LISTEN].ifq_ttl = fr_tcptimeout; + tqp[IPF_TCPS_SYN_SENT].ifq_ttl = fr_tcptimeout; + tqp[IPF_TCPS_SYN_RECEIVED].ifq_ttl = fr_tcptimeout; + tqp[IPF_TCPS_ESTABLISHED].ifq_ttl = fr_tcpidletimeout; + tqp[IPF_TCPS_CLOSE_WAIT].ifq_ttl = fr_tcphalfclosed; + tqp[IPF_TCPS_FIN_WAIT_1].ifq_ttl = fr_tcphalfclosed; + tqp[IPF_TCPS_CLOSING].ifq_ttl = fr_tcptimeout; + tqp[IPF_TCPS_LAST_ACK].ifq_ttl = fr_tcplastack; + tqp[IPF_TCPS_FIN_WAIT_2].ifq_ttl = fr_tcpclosewait; + tqp[IPF_TCPS_TIME_WAIT].ifq_ttl = fr_tcptimeout; + tqp[IPF_TCPS_HALF_ESTAB].ifq_ttl = fr_tcptimeout; +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_sttab_destroy */ +/* Returns: Nil */ +/* Parameters: tqp(I) - pointer to an array of timeout queues for TCP */ +/* */ +/* Do whatever is necessary to "destroy" each of the entries in the array */ +/* of timeout queues for TCP. */ +/* ------------------------------------------------------------------------ */ +void fr_sttab_destroy(tqp) +ipftq_t *tqp; +{ + int i; + + for (i = IPF_TCP_NSTATES - 1; i >= 0; i--) + MUTEX_DESTROY(&tqp[i].ifq_lock); +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_statederef */ +/* Returns: Nil */ +/* Parameters: isp(I) - pointer to pointer to state table entry */ +/* */ +/* Decrement the reference counter for this state table entry and free it */ +/* if there are no more things using it. */ +/* */ +/* When operating in userland (ipftest), we have no timers to clear a state */ +/* entry. Therefore, we make a few simple tests before deleting an entry */ +/* outright. We compare states on each side looking for a combination of */ +/* TIME_WAIT (should really be FIN_WAIT_2?) and LAST_ACK. Then we factor */ +/* in packet direction with the interface list to make sure we don't */ +/* prematurely delete an entry on a final inbound packet that's we're also */ +/* supposed to route elsewhere. */ +/* */ +/* Internal parameters: */ +/* state[0] = state of source (host that initiated connection) */ +/* state[1] = state of dest (host that accepted the connection) */ +/* */ +/* dir == 0 : a packet from source to dest */ +/* dir == 1 : a packet from dest to source */ +/* ------------------------------------------------------------------------ */ +void fr_statederef(fin, isp) +fr_info_t *fin; +ipstate_t **isp; +{ + ipstate_t *is = *isp; +#if 0 + int nstate, ostate, dir, eol; + + eol = 0; /* End-of-the-line flag. */ + dir = fin->fin_rev; + ostate = is->is_state[1 - dir]; + nstate = is->is_state[dir]; + /* + * Determine whether this packet is local or routed. State entries + * with us as the destination will have an interface list of + * int1,-,-,int1. Entries with us as the origin run as -,int1,int1,-. + */ + if ((fin->fin_p == IPPROTO_TCP) && (fin->fin_out == 0)) { + if ((strcmp(is->is_ifname[0], is->is_ifname[3]) == 0) && + (strcmp(is->is_ifname[1], is->is_ifname[2]) == 0)) { + if ((dir == 0) && + (strcmp(is->is_ifname[1], "-") == 0) && + (strcmp(is->is_ifname[0], "-") != 0)) { + eol = 1; + } else if ((dir == 1) && + (strcmp(is->is_ifname[0], "-") == 0) && + (strcmp(is->is_ifname[1], "-") != 0)) { + eol = 1; + } + } + } +#endif + + fin = fin; /* LINT */ + is = *isp; + *isp = NULL; + WRITE_ENTER(&ipf_state); + is->is_ref--; + if (is->is_ref == 0) { + is->is_ref++; /* To counter ref-- in fr_delstate() */ + fr_delstate(is, ISL_EXPIRE); +#ifndef _KERNEL +#if 0 + } else if (((fin->fin_out == 1) || (eol == 1)) && + ((ostate == IPF_TCPS_LAST_ACK) && + (nstate == IPF_TCPS_TIME_WAIT))) { + ; +#else + } else if ((is->is_sti.tqe_state[0] > IPF_TCPS_ESTABLISHED) || + (is->is_sti.tqe_state[1] > IPF_TCPS_ESTABLISHED)) { +#endif + fr_delstate(is, ISL_ORPHAN); +#endif + } + RWLOCK_EXIT(&ipf_state); +} + + +/* ------------------------------------------------------------------------ */ +/* Function: fr_setstatequeue */ +/* Returns: Nil */ +/* Parameters: is(I) - pointer to state structure */ +/* rev(I) - forward(0) or reverse(1) direction */ +/* Locks: ipf_state (read or write) */ +/* */ +/* Put the state entry on its default queue entry, using rev as a helped in */ +/* determining which queue it should be placed on. */ +/* ------------------------------------------------------------------------ */ +void fr_setstatequeue(is, rev) +ipstate_t *is; +int rev; +{ + ipftq_t *oifq, *nifq; + + + if ((is->is_sti.tqe_flags & TQE_RULEBASED) != 0) + nifq = is->is_tqehead[rev]; + else + nifq = NULL; + + if (nifq == NULL) { + switch (is->is_p) + { +#ifdef USE_INET6 + case IPPROTO_ICMPV6 : + if (rev == 1) + nifq = &ips_icmpacktq; + else + nifq = &ips_icmptq; + break; +#endif + case IPPROTO_ICMP : + if (rev == 1) + nifq = &ips_icmpacktq; + else + nifq = &ips_icmptq; + break; + case IPPROTO_TCP : + nifq = ips_tqtqb + is->is_state[rev]; + break; + + case IPPROTO_UDP : + if (rev == 1) + nifq = &ips_udpacktq; + else + nifq = &ips_udptq; + break; + + default : + nifq = &ips_iptq; + break; + } + } + + oifq = is->is_sti.tqe_ifq; + /* + * If it's currently on a timeout queue, move it from one queue to + * another, else put it on the end of the newly determined queue. + */ + if (oifq != NULL) + fr_movequeue(&is->is_sti, oifq, nifq); + else + fr_queueappend(&is->is_sti, nifq, is); + return; +} |
