diff options
Diffstat (limited to 'sys/contrib/ipfilter/netinet/ip_state.c')
-rw-r--r-- | sys/contrib/ipfilter/netinet/ip_state.c | 4197 |
1 files changed, 0 insertions, 4197 deletions
diff --git a/sys/contrib/ipfilter/netinet/ip_state.c b/sys/contrib/ipfilter/netinet/ip_state.c deleted file mode 100644 index a63f924..0000000 --- a/sys/contrib/ipfilter/netinet/ip_state.c +++ /dev/null @@ -1,4197 +0,0 @@ -/* - * Copyright (C) 1995-2003 by Darren Reed. - * - * See the IPFILTER.LICENCE file for details on licencing. - */ -#if defined(KERNEL) || defined(_KERNEL) -# undef KERNEL -# undef _KERNEL -# define KERNEL 1 -# define _KERNEL 1 -#endif -#include <sys/errno.h> -#include <sys/types.h> -#include <sys/param.h> -#include <sys/file.h> -#if defined(__NetBSD__) && (NetBSD >= 199905) && !defined(IPFILTER_LKM) && \ - defined(_KERNEL) -# if (__NetBSD_Version__ < 399001400) -# include "opt_ipfilter_log.h" -# else -# include "opt_ipfilter.h" -# endif -#endif -#if defined(_KERNEL) && defined(__FreeBSD_version) && \ - (__FreeBSD_version >= 400000) && !defined(KLD_MODULE) -#include "opt_inet6.h" -#endif -#if !defined(_KERNEL) && !defined(__KERNEL__) -# include <stdio.h> -# include <stdlib.h> -# include <string.h> -# define _KERNEL -# ifdef __OpenBSD__ -struct file; -# endif -# include <sys/uio.h> -# undef _KERNEL -#endif -#if defined(_KERNEL) && (__FreeBSD_version >= 220000) -# include <sys/filio.h> -# include <sys/fcntl.h> -# if (__FreeBSD_version >= 300000) && !defined(IPFILTER_LKM) -# include "opt_ipfilter.h" -# endif -#else -# include <sys/ioctl.h> -#endif -#include <sys/time.h> -#if !defined(linux) -# include <sys/protosw.h> -#endif -#include <sys/socket.h> -#if defined(_KERNEL) -# include <sys/systm.h> -# if !defined(__SVR4) && !defined(__svr4__) -# include <sys/mbuf.h> -# endif -#endif -#if defined(__SVR4) || defined(__svr4__) -# include <sys/filio.h> -# include <sys/byteorder.h> -# ifdef _KERNEL -# include <sys/dditypes.h> -# endif -# include <sys/stream.h> -# include <sys/kmem.h> -#endif - -#include <net/if.h> -#ifdef sun -# include <net/af.h> -#endif -#include <net/route.h> -#include <netinet/in.h> -#include <netinet/in_systm.h> -#include <netinet/ip.h> -#include <netinet/tcp.h> -#if !defined(linux) -# include <netinet/ip_var.h> -#endif -#if !defined(__hpux) && !defined(linux) -# include <netinet/tcp_fsm.h> -#endif -#include <netinet/udp.h> -#include <netinet/ip_icmp.h> -#include "netinet/ip_compat.h" -#include <netinet/tcpip.h> -#include "netinet/ip_fil.h" -#include "netinet/ip_nat.h" -#include "netinet/ip_frag.h" -#include "netinet/ip_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(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 2.186.2.80 2007/10/16 09:33:23 darrenr Exp $"; -#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 ipstate_t *fr_checkicmp6matchingstate __P((fr_info_t *)); -#endif -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 int fr_state_flush_entry __P((void *)); -static ips_stat_t *fr_statetstats __P((void)); -static int fr_delstate __P((ipstate_t *, int)); -static int fr_state_remove __P((caddr_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 *)); -static int fr_stateiter __P((ipftoken_t *, ipfgeniter_t *)); -static int fr_stgettable __P((char *)); - -int fr_stputent __P((caddr_t)); -int fr_stgetent __P((caddr_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) - -u_long fr_tcpidletimeout = FIVE_DAYS, - fr_tcpclosewait = IPF_TTLVAL(2 * TCP_MSL), - fr_tcplastack = IPF_TTLVAL(30), - fr_tcptimeout = IPF_TTLVAL(2 * TCP_MSL), - fr_tcptimewait = IPF_TTLVAL(2 * TCP_MSL), - fr_tcpclosed = IPF_TTLVAL(30), - 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_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_deletetq, - *ips_utqe = NULL; -#ifdef IPFILTER_LOG -int ipstate_logging = 1; -#else -int ipstate_logging = 0; -#endif -ipstate_t *ips_list = NULL; - - -/* ------------------------------------------------------------------------ */ -/* 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) - 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++) - icmpreplytype4[i] = -1; - icmpreplytype4[ICMP_ECHO] = ICMP_ECHOREPLY; - icmpreplytype4[ICMP_TSTAMP] = ICMP_TSTAMPREPLY; - icmpreplytype4[ICMP_IREQ] = ICMP_IREQREPLY; - icmpreplytype4[ICMP_MASKREQ] = ICMP_MASKREPLY; -#ifdef USE_INET6 - /* fill icmp reply type table */ - for (i = 0; i <= ICMP6_MAXTYPE; i++) - icmpreplytype6[i] = -1; - icmpreplytype6[ICMP6_ECHO_REQUEST] = ICMP6_ECHO_REPLY; - icmpreplytype6[ICMP6_MEMBERSHIP_QUERY] = ICMP6_MEMBERSHIP_REPORT; - icmpreplytype6[ICMP6_NI_QUERY] = ICMP6_NI_REPLY; - icmpreplytype6[ND_ROUTER_SOLICIT] = ND_ROUTER_ADVERT; - 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; - } - - ips_stats.iss_tcptab = ips_tqtqb; - 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 = &ips_deletetq; - ips_deletetq.ifq_ttl = (u_long)1; - ips_deletetq.ifq_ref = 1; - ips_deletetq.ifq_head = NULL; - ips_deletetq.ifq_tail = &ips_deletetq.ifq_head; - MUTEX_INIT(&ips_deletetq.ifq_lock, "state delete queue"); - ips_deletetq.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; -} - - -/* ------------------------------------------------------------------------ */ -/* 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() -{ - ipftq_t *ifq, *ifqnext; - ipstate_t *is; - - while ((is = ips_list) != NULL) - fr_delstate(is, ISL_UNLOAD); - - /* - * 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); - } - - ips_stats.iss_inuse = 0; - ips_num = 0; - - 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); - MUTEX_DESTROY(&ips_deletetq.ifq_lock); - } - - if (ips_table != NULL) { - KFREES(ips_table, fr_statesize * sizeof(*ips_table)); - ips_table = NULL; - } - - if (ips_seed != NULL) { - KFREES(ips_seed, fr_statesize * sizeof(*ips_seed)); - ips_seed = NULL; - } - - if (ips_stats.iss_bucketlen != NULL) { - KFREES(ips_stats.iss_bucketlen, fr_statesize * sizeof(u_long)); - ips_stats.iss_bucketlen = NULL; - } - - 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; -{ - ipstate_t *sp, st; - int error; - - sp = &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((caddr_t)&sp->is_src, (caddr_t)&st.is_src, - sizeof(st.is_src)) && - !bcmp((caddr_t)&sp->is_dst, (caddr_t)&st.is_src, - sizeof(st.is_dst)) && - !bcmp((caddr_t)&sp->is_ps, (caddr_t)&st.is_ps, - sizeof(st.is_ps))) { - fr_delstate(sp, ISL_REMOVE); - RWLOCK_EXIT(&ipf_state); - return 0; - } - RWLOCK_EXIT(&ipf_state); - return ESRCH; -} - - -/* ------------------------------------------------------------------------ */ -/* 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, uid, ctx) -caddr_t data; -ioctlcmd_t cmd; -int mode, uid; -void *ctx; -{ - int arg, ret, error = 0; - SPL_INT(s); - - switch (cmd) - { - /* - * Delete an entry from the state table. - */ - case SIOCDELST : - error = fr_state_remove(data); - break; - - /* - * Flush the state table - */ - case SIOCIPFFL : - error = BCOPYIN(data, (char *)&arg, sizeof(arg)); - if (error != 0) { - error = EFAULT; - } else { - WRITE_ENTER(&ipf_state); - ret = fr_state_flush(arg, 4); - RWLOCK_EXIT(&ipf_state); - error = BCOPYOUT((char *)&ret, data, sizeof(ret)); - if (error != 0) - error = EFAULT; - } - break; - -#ifdef USE_INET6 - case SIOCIPFL6 : - error = BCOPYIN(data, (char *)&arg, sizeof(arg)); - if (error != 0) { - error = EFAULT; - } else { - WRITE_ENTER(&ipf_state); - ret = fr_state_flush(arg, 6); - RWLOCK_EXIT(&ipf_state); - error = BCOPYOUT((char *)&ret, data, sizeof(ret)); - if (error != 0) - error = EFAULT; - } - break; -#endif -#ifdef IPFILTER_LOG - /* - * Flush the state log. - */ - case SIOCIPFFB : - if (!(mode & FWRITE)) - error = EPERM; - else { - int tmp; - - tmp = ipflog_clear(IPL_LOGSTATE); - error = BCOPYOUT((char *)&tmp, data, sizeof(tmp)); - if (error != 0) - error = EFAULT; - } - break; - - /* - * Turn logging of state information on/off. - */ - case SIOCSETLG : - if (!(mode & FWRITE)) - error = EPERM; - else { - error = BCOPYIN((char *)data, (char *)&ipstate_logging, - sizeof(ipstate_logging)); - if (error != 0) - error = EFAULT; - } - break; - - /* - * Return the current state of logging. - */ - case SIOCGETLG : - error = BCOPYOUT((char *)&ipstate_logging, (char *)data, - sizeof(ipstate_logging)); - if (error != 0) - error = EFAULT; - break; - - /* - * Return the number of bytes currently waiting to be read. - */ - case FIONREAD : - arg = iplused[IPL_LOGSTATE]; /* returned in an int */ - error = BCOPYOUT((char *)&arg, data, sizeof(arg)); - if (error != 0) - error = EFAULT; - 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 : - if (!(mode & FWRITE)) { - error = EPERM; - } else { - error = fr_lock(data, &fr_state_lock); - } - break; - - /* - * Add an entry to the current state table. - */ - case SIOCSTPUT : - if (!fr_state_lock || !(mode &FWRITE)) { - error = EACCES; - break; - } - error = fr_stputent(data); - break; - - /* - * Get a state table entry. - */ - case SIOCSTGET : - if (!fr_state_lock) { - error = EACCES; - break; - } - error = fr_stgetent(data); - break; - - /* - * Return a copy of the hash table bucket lengths - */ - case SIOCSTAT1 : - error = BCOPYOUT(ips_stats.iss_bucketlen, data, - fr_statesize * sizeof(u_long)); - if (error != 0) - error = EFAULT; - break; - - case SIOCGENITER : - { - ipftoken_t *token; - ipfgeniter_t iter; - - error = fr_inobj(data, &iter, IPFOBJ_GENITER); - if (error != 0) - break; - - SPL_SCHED(s); - token = ipf_findtoken(IPFGENITER_STATE, uid, ctx); - if (token != NULL) - error = fr_stateiter(token, &iter); - else - error = ESRCH; - RWLOCK_EXIT(&ipf_tokens); - SPL_X(s); - break; - } - - case SIOCGTABL : - error = fr_stgettable(data); - break; - - case SIOCIPFDELTOK : - error = BCOPYIN(data, (char *)&arg, sizeof(arg)); - if (error != 0) { - error = EFAULT; - } else { - SPL_SCHED(s); - error = ipf_deltoken(arg, uid, ctx); - SPL_X(s); - } - break; - - case SIOCGTQTAB : - error = fr_outobj(data, ips_tqtqb, IPFOBJ_STATETQTAB); - break; - - default : - error = EINVAL; - break; - } - return error; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_stgetent */ -/* Returns: int - 0 == success, != 0 == failure */ -/* Parameters: data(I) - pointer to state structure to retrieve from table */ -/* */ -/* Copy out state information from the kernel to a user space process. If */ -/* there is a filter rule associated with the state entry, copy that out */ -/* as well. The entry to copy out is taken from the value of "ips_next" in */ -/* the struct passed in and if not null and not found in the list of current*/ -/* state entries, the retrieval fails. */ -/* ------------------------------------------------------------------------ */ -int fr_stgetent(data) -caddr_t data; -{ - ipstate_t *is, *isn; - ipstate_save_t ips; - int error; - - error = fr_inobj(data, &ips, IPFOBJ_STATESAVE); - if (error != 0) - return error; - - isn = ips.ips_next; - if (isn == NULL) { - isn = ips_list; - if (isn == NULL) { - if (ips.ips_next == NULL) - return ENOENT; - return 0; - } - } else { - /* - * Make sure the pointer we're copying from exists in the - * current list of entries. Security precaution to prevent - * copying of random kernel data. - */ - for (is = ips_list; is; is = is->is_next) - if (is == isn) - break; - if (!is) - return ESRCH; - } - ips.ips_next = isn->is_next; - bcopy((char *)isn, (char *)&ips.ips_is, sizeof(ips.ips_is)); - ips.ips_rule = isn->is_rule; - if (isn->is_rule != NULL) - bcopy((char *)isn->is_rule, (char *)&ips.ips_fr, - sizeof(ips.ips_fr)); - error = fr_outobj(data, &ips, IPFOBJ_STATESAVE); - return error; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_stputent */ -/* Returns: int - 0 == success, != 0 == failure */ -/* Parameters: data(I) - pointer to state information struct */ -/* */ -/* This function implements the SIOCSTPUT ioctl: insert a state entry into */ -/* the state table. If the state info. includes a pointer to a filter rule */ -/* then also add in an orphaned rule (will not show up in any "ipfstat -io" */ -/* output. */ -/* ------------------------------------------------------------------------ */ -int fr_stputent(data) -caddr_t data; -{ - ipstate_t *is, *isn; - ipstate_save_t ips; - int error, out, i; - frentry_t *fr; - char *name; - - error = fr_inobj(data, &ips, IPFOBJ_STATESAVE); - if (error) - return EFAULT; - - KMALLOC(isn, ipstate_t *); - if (isn == NULL) - return ENOMEM; - - bcopy((char *)&ips.ips_is, (char *)isn, sizeof(*isn)); - bzero((char *)isn, offsetof(struct ipstate, is_pkts)); - isn->is_sti.tqe_pnext = NULL; - isn->is_sti.tqe_next = NULL; - isn->is_sti.tqe_ifq = NULL; - isn->is_sti.tqe_parent = isn; - isn->is_ifp[0] = NULL; - isn->is_ifp[1] = NULL; - isn->is_ifp[2] = NULL; - isn->is_ifp[3] = NULL; - isn->is_sync = NULL; - fr = ips.ips_rule; - - if (fr == NULL) { - READ_ENTER(&ipf_state); - fr_stinsert(isn, 0); - MUTEX_EXIT(&isn->is_lock); - RWLOCK_EXIT(&ipf_state); - return 0; - } - - if (isn->is_flags & SI_NEWFR) { - KMALLOC(fr, frentry_t *); - if (fr == NULL) { - KFREE(isn); - return ENOMEM; - } - bcopy((char *)&ips.ips_fr, (char *)fr, sizeof(*fr)); - out = fr->fr_flags & FR_OUTQUE ? 1 : 0; - isn->is_rule = fr; - ips.ips_is.is_rule = fr; - MUTEX_NUKE(&fr->fr_lock); - MUTEX_INIT(&fr->fr_lock, "state filter rule lock"); - - /* - * Look up all the interface names in the rule. - */ - for (i = 0; i < 4; i++) { - name = fr->fr_ifnames[i]; - fr->fr_ifas[i] = fr_resolvenic(name, fr->fr_v); - name = isn->is_ifname[i]; - isn->is_ifp[i] = fr_resolvenic(name, isn->is_v); - } - - fr->fr_ref = 0; - fr->fr_dsize = 0; - fr->fr_data = NULL; - fr->fr_type = FR_T_NONE; - - fr_resolvedest(&fr->fr_tifs[0], fr->fr_v); - fr_resolvedest(&fr->fr_tifs[1], 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); - MUTEX_EXIT(&isn->is_lock); - 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); - MUTEX_EXIT(&isn->is_lock); - break; - } - - if (is == NULL) { - KFREE(isn); - isn = NULL; - } - RWLOCK_EXIT(&ipf_state); - - return (isn == NULL) ? ESRCH : 0; - } - - return 0; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_stinsert */ -/* Returns: Nil */ -/* Parameters: is(I) - pointer to state structure */ -/* rev(I) - flag indicating forward/reverse direction of packet */ -/* */ -/* Inserts a state structure into the hash table (for lookups) and the list */ -/* of state entries (for enumeration). Resolves all of the interface names */ -/* to pointers and adjusts running stats for the hash table as appropriate. */ -/* */ -/* Locking: it is assumed that some kind of lock on ipf_state is held. */ -/* Exits with is_lock initialised and held. */ -/* ------------------------------------------------------------------------ */ -void fr_stinsert(is, rev) -ipstate_t *is; -int rev; -{ - frentry_t *fr; - u_int hv; - int i; - - MUTEX_INIT(&is->is_lock, "ipf state entry"); - - fr = is->is_rule; - if (fr != NULL) { - MUTEX_ENTER(&fr->fr_lock); - fr->fr_ref++; - fr->fr_statecnt++; - MUTEX_EXIT(&fr->fr_lock); - } - - /* - * Look up all the interface names in the state entry. - */ - for (i = 0; i < 4; i++) { - if (is->is_ifp[i] != NULL) - continue; - is->is_ifp[i] = fr_resolvenic(is->is_ifname[i], is->is_v); - } - - /* - * If we could trust is_hv, then the modulous would not be needed, but - * when running with IPFILTER_SYNC, this stops bad values. - */ - hv = is->is_hv % fr_statesize; - is->is_hv = hv; - - /* - * We need to get both of these locks...the first because it is - * possible that once the insert is complete another packet might - * come along, match the entry and want to update it. - */ - MUTEX_ENTER(&is->is_lock); - MUTEX_ENTER(&ipf_stinsert); - - /* - * add into list table. - */ - if (ips_list != NULL) - ips_list->is_pnext = &is->is_next; - is->is_pnext = &ips_list; - is->is_next = ips_list; - ips_list = is; - - if (ips_table[hv] != NULL) - ips_table[hv]->is_phnext = &is->is_hnext; - else - ips_stats.iss_inuse++; - is->is_phnext = ips_table + hv; - is->is_hnext = ips_table[hv]; - ips_table[hv] = is; - ips_stats.iss_bucketlen[hv]++; - ips_num++; - MUTEX_EXIT(&ipf_stinsert); - - fr_setstatequeue(is, rev); -} - - -/* ------------------------------------------------------------------------ */ -/* 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. */ -/* */ -/* NOTE: The use of stsave to point to nat_state will result in memory */ -/* corruption. It should only be used to point to objects that will */ -/* either outlive this (not expired) or will deref the ip_state_t */ -/* when they are deleted. */ -/* ------------------------------------------------------------------------ */ -ipstate_t *fr_addstate(fin, stsave, flags) -fr_info_t *fin; -ipstate_t **stsave; -u_int flags; -{ - ipstate_t *is, ips; - struct icmp *ic; - u_int pass, hv; - frentry_t *fr; - tcphdr_t *tcp; - grehdr_t *gre; - int out; - - if (fr_state_lock || - (fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD))) - return NULL; - - if ((fin->fin_flx & FI_OOW) && !(fin->fin_tcpf & TH_SYN)) - return NULL; - - /* - * 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". Note that because the lock isn't held on - * fr it is possible that we could overflow. The cost of overflowing - * is being ignored here as the number by which it can overflow is - * a product of the number of simultaneous threads that could be - * executing in here, so a limit of 100 won't result in 200, but could - * result in 101 or 102. - */ - fr = fin->fin_fr; - if (fr != NULL) { - if ((ips_num >= fr_statemax) && (fr->fr_statemax == 0)) { - ATOMIC_INCL(ips_stats.iss_max); - fr_state_doflush = 1; - return NULL; - } - if ((fr->fr_statemax != 0) && - (fr->fr_statecnt >= fr->fr_statemax)) { - ATOMIC_INCL(ips_stats.iss_maxref); - return NULL; - } - } - - pass = (fr == NULL) ? 0 : fr->fr_flags; - - ic = NULL; - tcp = NULL; - out = fin->fin_out; - is = &ips; - bzero((char *)is, sizeof(*is)); - is->is_die = 1 + fr_ticks; - - /* - * Copy and calculate... - */ - hv = (is->is_p = fin->fin_fi.fi_p); - is->is_src = fin->fin_fi.fi_src; - hv += is->is_saddr; - is->is_dst = fin->fin_fi.fi_dst; - hv += is->is_daddr; -#ifdef USE_INET6 - if (fin->fin_v == 6) { - /* - * For ICMPv6, we check to see if the destination address is - * a multicast address. If it is, do not include it in the - * calculation of the hash because the correct reply will come - * back from a real address, not a multicast address. - */ - if ((is->is_p == IPPROTO_ICMPV6) && - IN6_IS_ADDR_MULTICAST(&is->is_dst.in6)) { - /* - * So you can do keep state with neighbour discovery. - * - * Here we could use the address from the neighbour - * solicit message to put in the state structure and - * we could use that without a wildcard flag too... - */ - flags |= SI_W_DADDR; - hv -= is->is_daddr; - } else { - hv += is->is_dst.i6[1]; - hv += is->is_dst.i6[2]; - hv += is->is_dst.i6[3]; - } - hv += is->is_src.i6[1]; - hv += is->is_src.i6[2]; - hv += is->is_src.i6[3]; - } -#endif - if ((fin->fin_v == 4) && - (fin->fin_flx & (FI_MULTICAST|FI_BROADCAST|FI_MBCAST))) { - if (fin->fin_out == 0) { - flags |= SI_W_DADDR|SI_CLONE; - hv -= is->is_daddr; - } else { - flags |= SI_W_SADDR|SI_CLONE; - hv -= is->is_saddr; - } - } - - switch (is->is_p) - { -#ifdef USE_INET6 - case IPPROTO_ICMPV6 : - ic = fin->fin_dp; - - switch (ic->icmp_type) - { - case ICMP6_ECHO_REQUEST : - is->is_icmp.ici_type = ic->icmp_type; - hv += (is->is_icmp.ici_id = ic->icmp_id); - break; - case ICMP6_MEMBERSHIP_QUERY : - case ND_ROUTER_SOLICIT : - case ND_NEIGHBOR_SOLICIT : - case ICMP6_NI_QUERY : - is->is_icmp.ici_type = ic->icmp_type; - break; - default : - return NULL; - } - ATOMIC_INCL(ips_stats.iss_icmp); - break; -#endif - case IPPROTO_ICMP : - ic = fin->fin_dp; - - switch (ic->icmp_type) - { - case ICMP_ECHO : - case ICMP_TSTAMP : - case ICMP_IREQ : - case ICMP_MASKREQ : - is->is_icmp.ici_type = ic->icmp_type; - hv += (is->is_icmp.ici_id = ic->icmp_id); - break; - default : - return NULL; - } - ATOMIC_INCL(ips_stats.iss_icmp); - break; - - case IPPROTO_GRE : - gre = fin->fin_dp; - - is->is_gre.gs_flags = gre->gr_flags; - is->is_gre.gs_ptype = gre->gr_ptype; - if (GRE_REV(is->is_gre.gs_flags) == 1) { - is->is_call[0] = fin->fin_data[0]; - is->is_call[1] = fin->fin_data[1]; - } - break; - - case IPPROTO_TCP : - tcp = fin->fin_dp; - - if (tcp->th_flags & TH_RST) - return NULL; - /* - * The endian of the ports doesn't matter, but the ack and - * sequence numbers do as we do mathematics on them later. - */ - is->is_sport = htons(fin->fin_data[0]); - is->is_dport = htons(fin->fin_data[1]); - if ((flags & (SI_W_DPORT|SI_W_SPORT)) == 0) { - hv += is->is_sport; - hv += is->is_dport; - } - - /* - * If this is a real packet then initialise fields in the - * state information structure from the TCP header information. - */ - - is->is_maxdwin = 1; - is->is_maxswin = ntohs(tcp->th_win); - if (is->is_maxswin == 0) - is->is_maxswin = 1; - - if ((fin->fin_flx & FI_IGNORE) == 0) { - is->is_send = ntohl(tcp->th_seq) + fin->fin_dlen - - (TCP_OFF(tcp) << 2) + - ((tcp->th_flags & TH_SYN) ? 1 : 0) + - ((tcp->th_flags & TH_FIN) ? 1 : 0); - is->is_maxsend = is->is_send; - - /* - * Window scale option is only present in - * SYN/SYN-ACK packet. - */ - if ((tcp->th_flags & ~(TH_FIN|TH_ACK|TH_ECNALL)) == - TH_SYN && - (TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2))) { - if (fr_tcpoptions(fin, tcp, - &is->is_tcp.ts_data[0]) == -1) { - fin->fin_flx |= FI_BAD; - } - } - - if ((fin->fin_out != 0) && (pass & FR_NEWISN) != 0) { - fr_checknewisn(fin, is); - fr_fixoutisn(fin, is); - } - - if ((tcp->th_flags & TH_OPENING) == TH_SYN) - flags |= IS_TCPFSM; - else { - is->is_maxdwin = is->is_maxswin * 2; - is->is_dend = ntohl(tcp->th_ack); - is->is_maxdend = ntohl(tcp->th_ack); - is->is_maxdwin *= 2; - } - } - - /* - * If we're creating state for a starting connection, start the - * timer on it as we'll never see an error if it fails to - * connect. - */ - ATOMIC_INCL(ips_stats.iss_tcp); - break; - - case IPPROTO_UDP : - tcp = fin->fin_dp; - - is->is_sport = htons(fin->fin_data[0]); - is->is_dport = htons(fin->fin_data[1]); - if ((flags & (SI_W_DPORT|SI_W_SPORT)) == 0) { - hv += tcp->th_dport; - hv += tcp->th_sport; - } - ATOMIC_INCL(ips_stats.iss_udp); - break; - - default : - break; - } - hv = DOUBLE_HASH(hv); - is->is_hv = hv; - is->is_rule = fr; - is->is_flags = flags & IS_INHERITED; - - /* - * Look for identical state. - */ - for (is = ips_table[is->is_hv % fr_statesize]; is != NULL; - is = is->is_hnext) { - if (bcmp(&ips.is_src, &is->is_src, - offsetof(struct ipstate, is_ps) - - offsetof(struct ipstate, is_src)) == 0) - break; - } - if (is != NULL) - return NULL; - - if (ips_stats.iss_bucketlen[hv] >= fr_state_maxbucket) { - ATOMIC_INCL(ips_stats.iss_bucketfull); - return NULL; - } - KMALLOC(is, ipstate_t *); - if (is == NULL) { - ATOMIC_INCL(ips_stats.iss_nomem); - return NULL; - } - bcopy((char *)&ips, (char *)is, sizeof(*is)); - /* - * Do not do the modulous here, it is done in fr_stinsert(). - */ - if (fr != NULL) { - (void) strncpy(is->is_group, fr->fr_group, FR_GROUPLEN); - if (fr->fr_age[0] != 0) { - is->is_tqehead[0] = fr_addtimeoutqueue(&ips_utqe, - fr->fr_age[0]); - is->is_sti.tqe_flags |= TQE_RULEBASED; - } - if (fr->fr_age[1] != 0) { - is->is_tqehead[1] = fr_addtimeoutqueue(&ips_utqe, - fr->fr_age[1]); - is->is_sti.tqe_flags |= TQE_RULEBASED; - } - - is->is_tag = fr->fr_logtag; - - /* - * The name '-' is special for network interfaces and causes - * a NULL name to be present, always, allowing packets to - * match it, regardless of their interface. - */ - if ((fin->fin_ifp == NULL) || - (fr->fr_ifnames[out << 1][0] == '-' && - fr->fr_ifnames[out << 1][1] == '\0')) { - is->is_ifp[out << 1] = fr->fr_ifas[0]; - strncpy(is->is_ifname[out << 1], fr->fr_ifnames[0], - sizeof(fr->fr_ifnames[0])); - } else { - is->is_ifp[out << 1] = fin->fin_ifp; - COPYIFNAME(is->is_v, fin->fin_ifp, - is->is_ifname[out << 1]); - } - - is->is_ifp[(out << 1) + 1] = fr->fr_ifas[1]; - strncpy(is->is_ifname[(out << 1) + 1], fr->fr_ifnames[1], - sizeof(fr->fr_ifnames[1])); - - is->is_ifp[(1 - out) << 1] = fr->fr_ifas[2]; - strncpy(is->is_ifname[((1 - out) << 1)], fr->fr_ifnames[2], - sizeof(fr->fr_ifnames[2])); - - is->is_ifp[((1 - out) << 1) + 1] = fr->fr_ifas[3]; - strncpy(is->is_ifname[((1 - out) << 1) + 1], fr->fr_ifnames[3], - sizeof(fr->fr_ifnames[3])); - } else { - pass = fr_flags; - is->is_tag = FR_NOLOGTAG; - - if (fin->fin_ifp != NULL) { - is->is_ifp[out << 1] = fin->fin_ifp; - COPYIFNAME(is->is_v, fin->fin_ifp, - is->is_ifname[out << 1]); - } - } - - /* - * It may seem strange to set is_ref to 2, but fr_check() will call - * fr_statederef() after calling fr_addstate() and the idea is to - * have it exist at the end of fr_check() with is_ref == 1. - */ - is->is_ref = 2; - is->is_pass = pass; - is->is_pkts[0] = 0, is->is_bytes[0] = 0; - is->is_pkts[1] = 0, is->is_bytes[1] = 0; - is->is_pkts[2] = 0, is->is_bytes[2] = 0; - is->is_pkts[3] = 0, is->is_bytes[3] = 0; - if ((fin->fin_flx & FI_IGNORE) == 0) { - is->is_pkts[out] = 1; - is->is_bytes[out] = fin->fin_plen; - is->is_flx[out][0] = fin->fin_flx & FI_CMP; - is->is_flx[out][0] &= ~FI_OOW; - } - - if (pass & FR_STSTRICT) - is->is_flags |= IS_STRICT; - - if (pass & FR_STATESYNC) - is->is_flags |= IS_STATESYNC; - - /* - * We want to check everything that is a property of this packet, - * but we don't (automatically) care about it's fragment status as - * this may change. - */ - is->is_v = fin->fin_v; - is->is_opt[0] = fin->fin_optmsk; - is->is_optmsk[0] = 0xffffffff; - is->is_optmsk[1] = 0xffffffff; - if (is->is_v == 6) { - is->is_opt[0] &= ~0x8; - is->is_optmsk[0] &= ~0x8; - is->is_optmsk[1] &= ~0x8; - } - is->is_me = stsave; - is->is_sec = fin->fin_secmsk; - is->is_secmsk = 0xffff; - is->is_auth = fin->fin_auth; - is->is_authmsk = 0xffff; - if (flags & (SI_WILDP|SI_WILDA)) { - ATOMIC_INCL(ips_stats.iss_wild); - } - is->is_rulen = fin->fin_rule; - - - if (pass & FR_LOGFIRST) - is->is_pass &= ~(FR_LOGFIRST|FR_LOG); - - READ_ENTER(&ipf_state); - - 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. - */ - (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 - } else { - MUTEX_EXIT(&is->is_lock); - } -#ifdef IPFILTER_SYNC - if ((is->is_flags & IS_STATESYNC) && ((is->is_flags & SI_CLONE) == 0)) - is->is_sync = ipfsync_new(SMC_STATE, fin, is); -#endif - if (ipstate_logging) - ipstate_log(is, ISL_NEW); - - RWLOCK_EXIT(&ipf_state); - fin->fin_state = is; - fin->fin_rev = IP6_NEQ(&is->is_dst, &fin->fin_daddr); - fin->fin_flx |= FI_STATE; - if (fin->fin_flx & FI_FRAG) - (void) fr_newfrag(fin, pass ^ FR_KEEPSTATE); - - return is; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_tcpoptions */ -/* Returns: int - 1 == packet matches state entry, 0 == it does not, */ -/* -1 == packet has bad TCP options data */ -/* Parameters: fin(I) - pointer to packet information */ -/* tcp(I) - pointer to TCP packet header */ -/* td(I) - pointer to TCP data held as part of the state */ -/* */ -/* Look after the TCP header for any options and deal with those that are */ -/* present. Record details about those that we recogise. */ -/* ------------------------------------------------------------------------ */ -static int fr_tcpoptions(fin, tcp, td) -fr_info_t *fin; -tcphdr_t *tcp; -tcpdata_t *td; -{ - int off, mlen, ol, i, len, retval; - char buf[64], *s, opt; - mb_t *m = NULL; - - len = (TCP_OFF(tcp) << 2); - if (fin->fin_dlen < len) - return 0; - len -= sizeof(*tcp); - - off = fin->fin_plen - fin->fin_dlen + sizeof(*tcp) + fin->fin_ipoff; - - m = fin->fin_m; - mlen = MSGDSIZE(m) - off; - if (len > mlen) { - len = mlen; - retval = 0; - } else { - retval = 1; - } - - COPYDATA(m, off, len, buf); - - for (s = buf; len > 0; ) { - opt = *s; - if (opt == TCPOPT_EOL) - break; - else if (opt == TCPOPT_NOP) - ol = 1; - else { - if (len < 2) - break; - ol = (int)*(s + 1); - if (ol < 2 || ol > len) - break; - - /* - * Extract the TCP options we are interested in out of - * the header and store them in the the tcpdata struct. - */ - switch (opt) - { - case TCPOPT_WINDOW : - if (ol == TCPOLEN_WINDOW) { - i = (int)*(s + 2); - if (i > TCP_WSCALE_MAX) - i = TCP_WSCALE_MAX; - else if (i < 0) - i = 0; - td->td_winscale = i; - td->td_winflags |= TCP_WSCALE_SEEN| - TCP_WSCALE_FIRST; - } else - retval = -1; - 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; - } else - retval = -1; - break; - case TCPOPT_SACK_PERMITTED : - if (ol == TCPOLEN_SACK_PERMITTED) - td->td_winflags |= TCP_SACK_PERMIT; - else - retval = -1; - break; - } - } - len -= ol; - s += ol; - } - return retval; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_tcpstate */ -/* Returns: int - 1 == packet matches state entry, 0 == it does not */ -/* Parameters: fin(I) - pointer to packet information */ -/* tcp(I) - pointer to TCP packet header */ -/* is(I) - pointer to master state structure */ -/* */ -/* Check to see if a packet with TCP headers fits within the TCP window. */ -/* Change timeout depending on whether new packet is a SYN-ACK returning */ -/* for a SYN or a RST or FIN which indicate time to close up shop. */ -/* ------------------------------------------------------------------------ */ -static int fr_tcpstate(fin, tcp, is) -fr_info_t *fin; -tcphdr_t *tcp; -ipstate_t *is; -{ - int source, ret = 0, flags; - tcpdata_t *fdata, *tdata; - - source = !fin->fin_rev; - if (((is->is_flags & IS_TCPFSM) != 0) && (source == 1) && - (ntohs(is->is_sport) != fin->fin_data[0])) - source = 0; - fdata = &is->is_tcp.ts_data[!source]; - tdata = &is->is_tcp.ts_data[source]; - - MUTEX_ENTER(&is->is_lock); - - /* - * If a SYN packet is received for a connection that is on the way out - * but hasn't yet departed then advance this session along the way. - */ - if ((tcp->th_flags & TH_OPENING) == TH_SYN) { - if ((is->is_state[0] > IPF_TCPS_ESTABLISHED) && - (is->is_state[1] > IPF_TCPS_ESTABLISHED)) { - is->is_state[!source] = IPF_TCPS_CLOSED; - fr_movequeue(&is->is_sti, is->is_sti.tqe_ifq, - &ips_deletetq); - MUTEX_EXIT(&is->is_lock); - return 0; - } - } - - ret = fr_tcpinwindow(fin, fdata, tdata, tcp, is->is_flags); - if (ret > 0) { -#ifdef IPFILTER_SCAN - if (is->is_flags & (IS_SC_CLIENT|IS_SC_SERVER)) { - ipsc_packet(fin, is); - if (FR_ISBLOCK(is->is_pass)) { - MUTEX_EXIT(&is->is_lock); - return 1; - } - } -#endif - - /* - * Nearing end of connection, start timeout. - */ - ret = fr_tcp_age(&is->is_sti, fin, ips_tqtqb, is->is_flags); - if (ret == 0) { - MUTEX_EXIT(&is->is_lock); - return 0; - } - - /* - * set s0's as appropriate. Use syn-ack packet as it - * contains both pieces of required information. - */ - /* - * Window scale option is only present in SYN/SYN-ACK packet. - * Compare with ~TH_FIN to mask out T/TCP setups. - */ - flags = tcp->th_flags & ~(TH_FIN|TH_ECNALL); - if (flags == (TH_SYN|TH_ACK)) { - is->is_s0[source] = ntohl(tcp->th_ack); - is->is_s0[!source] = ntohl(tcp->th_seq) + 1; - if ((TCP_OFF(tcp) > (sizeof(tcphdr_t) >> 2))) { - if (fr_tcpoptions(fin, tcp, fdata) == -1) - fin->fin_flx |= FI_BAD; - } - 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, fdata) == -1) - fin->fin_flx |= FI_BAD; - } - - 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, */ -/* 2 == packet seq number matches next expected */ -/* 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; - int dsize, inseq; - - /* - * Find difference between last checked packet and this packet. - */ - tcpflags = tcp->th_flags; - seq = ntohl(tcp->th_seq); - ack = ntohl(tcp->th_ack); - if (tcpflags & TH_SYN) - win = ntohs(tcp->th_win); - else - win = ntohs(tcp->th_win) << fdata->td_winscale; - - /* - * A window of 0 produces undesirable behaviour from this function. - */ - if (win == 0) - win = 1; - - dsize = fin->fin_dlen - (TCP_OFF(tcp) << 2) + - ((tcpflags & TH_SYN) ? 1 : 0) + ((tcpflags & TH_FIN) ? 1 : 0); - - /* - * 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)) { - fdata->td_winflags &= ~TCP_WSCALE_FIRST; - fdata->td_maxwin = win; - } - - end = seq + dsize; - - if ((fdata->td_end == 0) && - (!(flags & IS_TCPFSM) || - ((tcpflags & TH_OPENING) == TH_OPENING))) { - /* - * Must be a (outgoing) SYN-ACK in reply to a SYN. - */ - fdata->td_end = end - 1; - fdata->td_maxwin = 1; - fdata->td_maxend = end + win; - } - - if (!(tcpflags & TH_ACK)) { /* Pretend an ack was sent */ - ack = tdata->td_end; - } else if (((tcpflags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) && - (ack == 0)) { - /* gross hack to get around certain broken tcp stacks */ - ack = tdata->td_end; - } - - maxwin = tdata->td_maxwin; - ackskew = tdata->td_end - ack; - - /* - * Strict sequencing only allows in-order delivery. - */ - if (seq != fdata->td_end) { - if ((flags & IS_STRICT) != 0) { - return 0; - } - } - - inseq = 0; - if ((SEQ_GE(fdata->td_maxend, end)) && - (SEQ_GE(seq, fdata->td_end - maxwin)) && -/* XXX what about big packets */ -#define MAXACKWINDOW 66000 - (-ackskew <= (MAXACKWINDOW)) && - ( ackskew <= (MAXACKWINDOW << fdata->td_winscale))) { - inseq = 1; - /* - * Microsoft Windows will send the next packet to the right of the - * window if SACK is in use. - */ - } else if ((seq == fdata->td_maxend) && (ackskew == 0) && - (fdata->td_winflags & TCP_SACK_PERMIT) && - (tdata->td_winflags & TCP_SACK_PERMIT)) { - inseq = 1; - /* - * Sometimes a TCP RST will be generated with only the ACK field - * set to non-zero. - */ - } else if ((seq == 0) && (tcpflags == (TH_RST|TH_ACK)) && - (ackskew >= -1) && (ackskew <= 1)) { - inseq = 1; - } else if (!(flags & IS_TCPFSM)) { - int i; - - i = (fin->fin_rev << 1) + fin->fin_out; - -#if 0 - if (is_pkts[i]0 == 0) { - /* - * Picking up a connection in the middle, the "next" - * packet seen from a direction that is new should be - * accepted, even if it appears out of sequence. - */ - inseq = 1; - } else -#endif - if (!(fdata->td_winflags & - (TCP_WSCALE_SEEN|TCP_WSCALE_FIRST))) { - /* - * No TCPFSM and no window scaling, so make some - * extra guesses. - */ - if ((seq == fdata->td_maxend) && (ackskew == 0)) - inseq = 1; - else if (SEQ_GE(seq + maxwin, fdata->td_end - maxwin)) - inseq = 1; - } - } - - /* TRACE(inseq, fdata, tdata, seq, end, ack, ackskew, win, maxwin) */ - - if (inseq) { - /* if ackskew < 0 then this should be due to fragmented - * packets. There is no way to know the length of the - * total packet in advance. - * We do know the total length from the fragment cache though. - * Note however that there might be more sessions with - * exactly the same source and destination parameters in the - * state cache (and source and destination is the only stuff - * that is saved in the fragment cache). Note further that - * some TCP connections in the state cache are hashed with - * sport and dport as well which makes it not worthwhile to - * look for them. - * Thus, when ackskew is negative but still seems to belong - * to this session, we bump up the destinations end value. - */ - if (ackskew < 0) - tdata->td_end = ack; - - /* update max window seen */ - if (fdata->td_maxwin < win) - fdata->td_maxwin = win; - if (SEQ_GT(end, fdata->td_end)) - fdata->td_end = end; - if (SEQ_GE(ack + win, tdata->td_maxend)) - tdata->td_maxend = ack + win; - return 1; - } - return 0; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_stclone */ -/* Returns: ipstate_t* - NULL == cloning failed, */ -/* else pointer to new state structure */ -/* Parameters: fin(I) - pointer to packet information */ -/* tcp(I) - pointer to TCP/UDP header */ -/* is(I) - pointer to master state structure */ -/* */ -/* Create a "duplcate" state table entry from the master. */ -/* ------------------------------------------------------------------------ */ -static ipstate_t *fr_stclone(fin, tcp, is) -fr_info_t *fin; -tcphdr_t *tcp; -ipstate_t *is; -{ - ipstate_t *clone; - u_32_t send; - - if (ips_num == fr_statemax) { - ATOMIC_INCL(ips_stats.iss_max); - fr_state_doflush = 1; - return NULL; - } - KMALLOC(clone, ipstate_t *); - if (clone == NULL) - return NULL; - bcopy((char *)is, (char *)clone, sizeof(*clone)); - - MUTEX_NUKE(&clone->is_lock); - - clone->is_die = ONE_DAY + fr_ticks; - clone->is_state[0] = 0; - clone->is_state[1] = 0; - send = ntohl(tcp->th_seq) + fin->fin_dlen - (TCP_OFF(tcp) << 2) + - ((tcp->th_flags & TH_SYN) ? 1 : 0) + - ((tcp->th_flags & TH_FIN) ? 1 : 0); - - if (fin->fin_rev == 1) { - clone->is_dend = send; - clone->is_maxdend = send; - clone->is_send = 0; - clone->is_maxswin = 1; - clone->is_maxdwin = ntohs(tcp->th_win); - if (clone->is_maxdwin == 0) - clone->is_maxdwin = 1; - } else { - clone->is_send = send; - clone->is_maxsend = send; - clone->is_dend = 0; - clone->is_maxdwin = 1; - clone->is_maxswin = ntohs(tcp->th_win); - if (clone->is_maxswin == 0) - clone->is_maxswin = 1; - } - - clone->is_flags &= ~SI_CLONE; - clone->is_flags |= SI_CLONED; - fr_stinsert(clone, fin->fin_rev); - clone->is_ref = 2; - if (clone->is_p == IPPROTO_TCP) { - (void) fr_tcp_age(&clone->is_sti, fin, ips_tqtqb, - clone->is_flags); - } - MUTEX_EXIT(&clone->is_lock); -#ifdef IPFILTER_SCAN - (void) ipsc_attachis(is); -#endif -#ifdef IPFILTER_SYNC - if (is->is_flags & IS_STATESYNC) - clone->is_sync = ipfsync_new(SMC_STATE, fin, clone); -#endif - return clone; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_matchsrcdst */ -/* Returns: Nil */ -/* Parameters: fin(I) - pointer to packet information */ -/* is(I) - pointer to state structure */ -/* src(I) - pointer to source address */ -/* dst(I) - pointer to destination address */ -/* tcp(I) - pointer to TCP/UDP header */ -/* */ -/* Match a state table entry against an IP packet. The logic below is that */ -/* ret gets set to one if the match succeeds, else remains 0. If it is */ -/* still 0 after the test. no match. */ -/* ------------------------------------------------------------------------ */ -static ipstate_t *fr_matchsrcdst(fin, is, src, dst, tcp, cmask) -fr_info_t *fin; -ipstate_t *is; -i6addr_t *src, *dst; -tcphdr_t *tcp; -u_32_t cmask; -{ - int ret = 0, rev, out, flags, flx = 0, idx; - u_short sp, dp; - u_32_t cflx; - void *ifp; - - rev = IP6_NEQ(&is->is_dst, dst); - ifp = fin->fin_ifp; - out = fin->fin_out; - flags = is->is_flags; - sp = 0; - dp = 0; - - if (tcp != NULL) { - sp = htons(fin->fin_sport); - dp = ntohs(fin->fin_dport); - } - if (!rev) { - if (tcp != NULL) { - if (!(flags & SI_W_SPORT) && (sp != is->is_sport)) - rev = 1; - else if (!(flags & SI_W_DPORT) && (dp != is->is_dport)) - rev = 1; - } - } - - idx = (out << 1) + rev; - - /* - * If the interface for this 'direction' is set, make sure it matches. - * An interface name that is not set matches any, as does a name of *. - */ - if ((is->is_ifp[idx] == ifp) || (is->is_ifp[idx] == NULL && - (*is->is_ifname[idx] == '\0' || *is->is_ifname[idx] == '-' || - *is->is_ifname[idx] == '*'))) - ret = 1; - - if (ret == 0) - return NULL; - ret = 0; - - /* - * Match addresses and ports. - */ - if (rev == 0) { - if ((IP6_EQ(&is->is_dst, dst) || (flags & SI_W_DADDR)) && - (IP6_EQ(&is->is_src, src) || (flags & SI_W_SADDR))) { - if (tcp) { - if ((sp == is->is_sport || flags & SI_W_SPORT)&& - (dp == is->is_dport || flags & SI_W_DPORT)) - ret = 1; - } else { - ret = 1; - } - } - } else { - if ((IP6_EQ(&is->is_dst, src) || (flags & SI_W_DADDR)) && - (IP6_EQ(&is->is_src, dst) || (flags & SI_W_SADDR))) { - if (tcp) { - if ((dp == is->is_sport || flags & SI_W_SPORT)&& - (sp == is->is_dport || flags & SI_W_DPORT)) - ret = 1; - } else { - ret = 1; - } - } - } - - if (ret == 0) - return NULL; - - /* - * Whether or not this should be here, is questionable, but the aim - * is to get this out of the main line. - */ - if (tcp == NULL) - flags = is->is_flags & ~(SI_WILDP|SI_NEWFR|SI_CLONE|SI_CLONED); - - /* - * Only one of the source or destination address can be flaged as a - * wildcard. Fill in the missing address, if set. - * For IPv6, if the address being copied in is multicast, then - * don't reset the wild flag - multicast causes it to be set in the - * first place! - */ - if ((flags & (SI_W_SADDR|SI_W_DADDR))) { - fr_ip_t *fi = &fin->fin_fi; - - if ((flags & SI_W_SADDR) != 0) { - if (rev == 0) { -#ifdef USE_INET6 - if (is->is_v == 6 && - IN6_IS_ADDR_MULTICAST(&fi->fi_src.in6)) - /*EMPTY*/; - else -#endif - { - is->is_src = fi->fi_src; - is->is_flags &= ~SI_W_SADDR; - } - } else { -#ifdef USE_INET6 - if (is->is_v == 6 && - IN6_IS_ADDR_MULTICAST(&fi->fi_dst.in6)) - /*EMPTY*/; - else -#endif - { - is->is_src = fi->fi_dst; - is->is_flags &= ~SI_W_SADDR; - } - } - } else if ((flags & SI_W_DADDR) != 0) { - if (rev == 0) { -#ifdef USE_INET6 - if (is->is_v == 6 && - IN6_IS_ADDR_MULTICAST(&fi->fi_dst.in6)) - /*EMPTY*/; - else -#endif - { - is->is_dst = fi->fi_dst; - is->is_flags &= ~SI_W_DADDR; - } - } else { -#ifdef USE_INET6 - if (is->is_v == 6 && - IN6_IS_ADDR_MULTICAST(&fi->fi_src.in6)) - /*EMPTY*/; - else -#endif - { - is->is_dst = fi->fi_src; - is->is_flags &= ~SI_W_DADDR; - } - } - } - if ((is->is_flags & (SI_WILDA|SI_WILDP)) == 0) { - ATOMIC_DECL(ips_stats.iss_wild); - } - } - - flx = fin->fin_flx & cmask; - cflx = is->is_flx[out][rev]; - - /* - * Match up any flags set from IP options. - */ - if ((cflx && (flx != (cflx & cmask))) || - ((fin->fin_optmsk & is->is_optmsk[rev]) != is->is_opt[rev]) || - ((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) { - ipstate_t *clone; - - clone = fr_stclone(fin, tcp, is); - if (clone == NULL) - return NULL; - is = clone; - } else { - ATOMIC_DECL(ips_stats.iss_wild); - } - - if ((flags & SI_W_SPORT) != 0) { - if (rev == 0) { - is->is_sport = sp; - is->is_send = ntohl(tcp->th_seq); - } else { - is->is_sport = dp; - is->is_send = ntohl(tcp->th_ack); - } - is->is_maxsend = is->is_send + 1; - } else if ((flags & SI_W_DPORT) != 0) { - if (rev == 0) { - is->is_dport = dp; - is->is_dend = ntohl(tcp->th_ack); - } else { - is->is_dport = sp; - is->is_dend = ntohl(tcp->th_seq); - } - is->is_maxdend = is->is_dend + 1; - } - is->is_flags &= ~(SI_W_SPORT|SI_W_DPORT); - if ((flags & SI_CLONED) && ipstate_logging) - ipstate_log(is, ISL_CLONE); - } - - ret = -1; - - if (is->is_flx[out][rev] == 0) { - is->is_flx[out][rev] = flx; - is->is_opt[rev] = fin->fin_optmsk; - if (is->is_v == 6) { - is->is_opt[rev] &= ~0x8; - is->is_optmsk[rev] &= ~0x8; - } - } - - /* - * 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(is->is_v, ifp, is->is_ifname[idx]); - } - fin->fin_rev = rev; - return is; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_checkicmpmatchingstate */ -/* Returns: Nil */ -/* Parameters: fin(I) - pointer to packet information */ -/* */ -/* If we've got an ICMP error message, using the information stored in the */ -/* ICMP packet, look for a matching state table entry. */ -/* */ -/* If we return NULL then no lock on ipf_state is held. */ -/* If we return non-null then a read-lock on ipf_state is held. */ -/* ------------------------------------------------------------------------ */ -static ipstate_t *fr_checkicmpmatchingstate(fin) -fr_info_t *fin; -{ - ipstate_t *is, **isp; - u_short sport, dport; - u_char pr; - int backward, i, oi; - i6addr_t dst, src; - struct icmp *ic; - u_short savelen; - icmphdr_t *icmp; - fr_info_t ofin; - tcphdr_t *tcp; - int type, len; - ip_t *oip; - u_int hv; - - /* - * Does it at least have the return (basic) IP header ? - * Is it an actual recognised ICMP error type? - * Only a basic IP header (no options) should be with - * an ICMP error header. - */ - if ((fin->fin_v != 4) || (fin->fin_hlen != sizeof(ip_t)) || - (fin->fin_plen < ICMPERR_MINPKTLEN) || - !(fin->fin_flx & FI_ICMPERR)) - return NULL; - ic = fin->fin_dp; - type = ic->icmp_type; - - oip = (ip_t *)((char *)ic + ICMPERR_ICMPHLEN); - /* - * Check if the at least the old IP header (with options) and - * 8 bytes of payload is present. - */ - if (fin->fin_plen < ICMPERR_MAXPKTLEN + ((IP_HL(oip) - 5) << 2)) - return NULL; - - /* - * Sanity Checks. - */ - len = fin->fin_dlen - ICMPERR_ICMPHLEN; - if ((len <= 0) || ((IP_HL(oip) << 2) > len)) - return NULL; - - /* - * Is the buffer big enough for all of it ? It's the size of the IP - * header claimed in the encapsulated part which is of concern. It - * may be too big to be in this buffer but not so big that it's - * outside the ICMP packet, leading to TCP deref's causing problems. - * This is possible because we don't know how big oip_hl is when we - * do the pullup early in fr_check() and thus can't guarantee it is - * all here now. - */ -#ifdef _KERNEL - { - mb_t *m; - - m = fin->fin_m; -# if defined(MENTAT) - if ((char *)oip + len > (char *)m->b_wptr) - return NULL; -# else - if ((char *)oip + len > (char *)fin->fin_ip + m->m_len) - return NULL; -# endif - } -#endif - bcopy((char *)fin, (char *)&ofin, sizeof(*fin)); - - /* - * in the IPv4 case we must zero the i6addr union otherwise - * the IP6_EQ and IP6_NEQ macros produce the wrong results because - * of the 'junk' in the unused part of the union - */ - bzero((char *)&src, sizeof(src)); - bzero((char *)&dst, sizeof(dst)); - - /* - * we make an fin entry to be able to feed it to - * matchsrcdst note that not all fields are encessary - * but this is the cleanest way. Note further we fill - * in fin_mp such that if someone uses it we'll get - * a kernel panic. fr_matchsrcdst does not use this. - * - * watch out here, as ip is in host order and oip in network - * order. Any change we make must be undone afterwards, like - * oip->ip_off - it is still in network byte order so fix it. - */ - savelen = oip->ip_len; - oip->ip_len = len; - oip->ip_off = ntohs(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 */ - (void) fr_makefrip(IP_HL(oip) << 2, oip, &ofin); - ofin.fin_ifp = fin->fin_ifp; - ofin.fin_out = !fin->fin_out; - /* - * Reset the short and bad flag here because in fr_matchsrcdst() - * the flags for the current packet (fin_flx) are compared against - * those for the existing session. - */ - ofin.fin_flx &= ~(FI_BAD|FI_SHORT); - - /* - * Put old values of ip_len and ip_off back as we don't know - * if we have to forward the packet (or process it again. - */ - oip->ip_len = savelen; - oip->ip_off = htons(oip->ip_off); - - switch (oip->ip_p) - { - case IPPROTO_ICMP : - /* - * an ICMP error can only be generated as a result of an - * ICMP query, not as the response on an ICMP error - * - * XXX theoretically ICMP_ECHOREP and the other reply's are - * ICMP query's as well, but adding them here seems strange XXX - */ - if ((ofin.fin_flx & FI_ICMPERR) != 0) - return NULL; - - /* - * perform a lookup of the ICMP packet in the state table - */ - icmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2)); - hv = (pr = oip->ip_p); - src.in4 = oip->ip_src; - hv += src.in4.s_addr; - dst.in4 = oip->ip_dst; - hv += dst.in4.s_addr; - hv += icmp->icmp_id; - hv = DOUBLE_HASH(hv); - - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { - isp = &is->is_hnext; - if ((is->is_p != pr) || (is->is_v != 4)) - continue; - if (is->is_pass & FR_NOICMPERR) - continue; - is = fr_matchsrcdst(&ofin, is, &src, &dst, - NULL, FI_ICMPCMP); - if (is != NULL) { - /* - * i : the index of this packet (the icmp - * unreachable) - * oi : the index of the original packet found - * in the icmp header (i.e. the packet - * causing this icmp) - * backward : original packet was backward - * compared to the state - */ - backward = IP6_NEQ(&is->is_src, &src); - fin->fin_rev = !backward; - i = (!backward << 1) + fin->fin_out; - oi = (backward << 1) + ofin.fin_out; - if (is->is_icmppkts[i] > is->is_pkts[oi]) - continue; - ips_stats.iss_hits++; - is->is_icmppkts[i]++; - return is; - } - } - RWLOCK_EXIT(&ipf_state); - return NULL; - case IPPROTO_TCP : - case IPPROTO_UDP : - break; - default : - return NULL; - } - - tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2)); - dport = tcp->th_dport; - sport = tcp->th_sport; - - hv = (pr = oip->ip_p); - src.in4 = oip->ip_src; - hv += src.in4.s_addr; - dst.in4 = oip->ip_dst; - hv += dst.in4.s_addr; - hv += dport; - hv += sport; - hv = DOUBLE_HASH(hv); - - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { - isp = &is->is_hnext; - /* - * Only allow this icmp though if the - * encapsulated packet was allowed through the - * other way around. Note that the minimal amount - * of info present does not allow for checking against - * tcp internals such as seq and ack numbers. Only the - * ports are known to be present and can be even if the - * short flag is set. - */ - if ((is->is_p == pr) && (is->is_v == 4) && - (is = fr_matchsrcdst(&ofin, is, &src, &dst, - tcp, FI_ICMPCMP))) { - /* - * i : the index of this packet (the icmp unreachable) - * oi : the index of the original packet found in the - * icmp header (i.e. the packet causing this icmp) - * backward : original packet was backward compared to - * the state - */ - backward = IP6_NEQ(&is->is_src, &src); - fin->fin_rev = !backward; - i = (!backward << 1) + fin->fin_out; - oi = (backward << 1) + ofin.fin_out; - - if (((is->is_pass & FR_NOICMPERR) != 0) || - (is->is_icmppkts[i] > is->is_pkts[oi])) - break; - ips_stats.iss_hits++; - is->is_icmppkts[i]++; - /* - * we deliberately do not touch the timeouts - * for the accompanying state table entry. - * It remains to be seen if that is correct. XXX - */ - return is; - } - } - RWLOCK_EXIT(&ipf_state); - return NULL; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_ipsmove */ -/* Returns: Nil */ -/* Parameters: is(I) - pointer to state table entry */ -/* hv(I) - new hash value for state table entry */ -/* Write Locks: ipf_state */ -/* */ -/* Move a state entry from one position in the hash table to another. */ -/* ------------------------------------------------------------------------ */ -static void fr_ipsmove(is, hv) -ipstate_t *is; -u_int hv; -{ - ipstate_t **isp; - u_int hvm; - - hvm = is->is_hv; - /* - * Remove the hash from the old location... - */ - isp = is->is_phnext; - if (is->is_hnext) - is->is_hnext->is_phnext = isp; - *isp = is->is_hnext; - if (ips_table[hvm] == NULL) - ips_stats.iss_inuse--; - ips_stats.iss_bucketlen[hvm]--; - - /* - * ...and put the hash in the new one. - */ - hvm = DOUBLE_HASH(hv); - is->is_hv = hvm; - isp = &ips_table[hvm]; - if (*isp) - (*isp)->is_phnext = &is->is_hnext; - else - ips_stats.iss_inuse++; - ips_stats.iss_bucketlen[hvm]++; - is->is_phnext = isp; - is->is_hnext = *isp; - *isp = is; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_stlookup */ -/* Returns: ipstate_t* - NULL == no matching state found, */ -/* else pointer to state information is returned */ -/* Parameters: fin(I) - pointer to packet information */ -/* tcp(I) - pointer to TCP/UDP header. */ -/* */ -/* Search the state table for a matching entry to the packet described by */ -/* the contents of *fin. */ -/* */ -/* If we return NULL then no lock on ipf_state is held. */ -/* If we return non-null then a read-lock on ipf_state is held. */ -/* ------------------------------------------------------------------------ */ -ipstate_t *fr_stlookup(fin, tcp, ifqp) -fr_info_t *fin; -tcphdr_t *tcp; -ipftq_t **ifqp; -{ - u_int hv, hvm, pr, v, tryagain; - ipstate_t *is, **isp; - u_short dport, sport; - i6addr_t src, dst; - struct icmp *ic; - ipftq_t *ifq; - int oow; - - is = NULL; - ifq = NULL; - tcp = fin->fin_dp; - ic = (struct icmp *)tcp; - hv = (pr = fin->fin_fi.fi_p); - src = fin->fin_fi.fi_src; - dst = fin->fin_fi.fi_dst; - hv += src.in4.s_addr; - hv += dst.in4.s_addr; - - v = fin->fin_fi.fi_v; -#ifdef USE_INET6 - if (v == 6) { - hv += fin->fin_fi.fi_src.i6[1]; - hv += fin->fin_fi.fi_src.i6[2]; - hv += fin->fin_fi.fi_src.i6[3]; - - if ((fin->fin_p == IPPROTO_ICMPV6) && - IN6_IS_ADDR_MULTICAST(&fin->fin_fi.fi_dst.in6)) { - hv -= dst.in4.s_addr; - } else { - hv += fin->fin_fi.fi_dst.i6[1]; - hv += fin->fin_fi.fi_dst.i6[2]; - hv += fin->fin_fi.fi_dst.i6[3]; - } - } -#endif - if ((v == 4) && - (fin->fin_flx & (FI_MULTICAST|FI_BROADCAST|FI_MBCAST))) { - if (fin->fin_out == 0) { - hv -= src.in4.s_addr; - } else { - hv -= dst.in4.s_addr; - } - } - - /* - * Search the hash table for matching packet header info. - */ - switch (pr) - { -#ifdef USE_INET6 - case IPPROTO_ICMPV6 : - tryagain = 0; - if (v == 6) { - if ((ic->icmp_type == ICMP6_ECHO_REQUEST) || - (ic->icmp_type == ICMP6_ECHO_REPLY)) { - hv += ic->icmp_id; - } - } - READ_ENTER(&ipf_state); -icmp6again: - hvm = DOUBLE_HASH(hv); - for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) { - isp = &is->is_hnext; - /* - * If a connection is about to be deleted, no packets - * are allowed to match it. - */ - if (is->is_sti.tqe_ifq == &ips_deletetq) - continue; - - if ((is->is_p != pr) || (is->is_v != v)) - continue; - is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); - if (is != NULL && - fr_matchicmpqueryreply(v, &is->is_icmp, - ic, fin->fin_rev)) { - if (fin->fin_rev) - ifq = &ips_icmpacktq; - else - ifq = &ips_icmptq; - break; - } - } - - if (is != NULL) { - if ((tryagain != 0) && !(is->is_flags & SI_W_DADDR)) { - hv += fin->fin_fi.fi_src.i6[0]; - hv += fin->fin_fi.fi_src.i6[1]; - hv += fin->fin_fi.fi_src.i6[2]; - hv += fin->fin_fi.fi_src.i6[3]; - fr_ipsmove(is, hv); - MUTEX_DOWNGRADE(&ipf_state); - } - break; - } - RWLOCK_EXIT(&ipf_state); - - /* - * No matching icmp state entry. Perhaps this is a - * response to another state entry. - * - * XXX With some ICMP6 packets, the "other" address is already - * in the packet, after the ICMP6 header, and this could be - * used in place of the multicast address. However, taking - * advantage of this requires some significant code changes - * to handle the specific types where that is the case. - */ - if ((ips_stats.iss_wild != 0) && (v == 6) && (tryagain == 0) && - !IN6_IS_ADDR_MULTICAST(&fin->fin_fi.fi_src.in6)) { - hv -= fin->fin_fi.fi_src.i6[0]; - hv -= fin->fin_fi.fi_src.i6[1]; - hv -= fin->fin_fi.fi_src.i6[2]; - hv -= fin->fin_fi.fi_src.i6[3]; - tryagain = 1; - WRITE_ENTER(&ipf_state); - goto icmp6again; - } - - is = fr_checkicmp6matchingstate(fin); - if (is != NULL) - return is; - break; -#endif - - case IPPROTO_ICMP : - if (v == 4) { - hv += ic->icmp_id; - } - hv = DOUBLE_HASH(hv); - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { - isp = &is->is_hnext; - if ((is->is_p != pr) || (is->is_v != v)) - continue; - is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); - if ((is != NULL) && - (ic->icmp_id == is->is_icmp.ici_id) && - fr_matchicmpqueryreply(v, &is->is_icmp, - ic, fin->fin_rev)) { - if (fin->fin_rev) - ifq = &ips_icmpacktq; - else - ifq = &ips_icmptq; - break; - } - } - if (is == NULL) { - RWLOCK_EXIT(&ipf_state); - } - break; - - case IPPROTO_TCP : - case IPPROTO_UDP : - ifqp = NULL; - sport = htons(fin->fin_data[0]); - hv += sport; - dport = htons(fin->fin_data[1]); - hv += dport; - oow = 0; - tryagain = 0; - READ_ENTER(&ipf_state); -retry_tcpudp: - hvm = DOUBLE_HASH(hv); - for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) { - isp = &is->is_hnext; - if ((is->is_p != pr) || (is->is_v != v)) - continue; - fin->fin_flx &= ~FI_OOW; - is = fr_matchsrcdst(fin, is, &src, &dst, tcp, FI_CMP); - if (is != NULL) { - if (pr == IPPROTO_TCP) { - if (!fr_tcpstate(fin, tcp, is)) { - oow |= fin->fin_flx & FI_OOW; - continue; - } - } - break; - } - } - if (is != NULL) { - if (tryagain && - !(is->is_flags & (SI_CLONE|SI_WILDP|SI_WILDA))) { - hv += dport; - hv += sport; - fr_ipsmove(is, hv); - MUTEX_DOWNGRADE(&ipf_state); - } - break; - } - RWLOCK_EXIT(&ipf_state); - - if (ips_stats.iss_wild) { - if (tryagain == 0) { - hv -= dport; - hv -= sport; - } else if (tryagain == 1) { - hv = fin->fin_fi.fi_p; - /* - * If we try to pretend this is a reply to a - * multicast/broadcast packet then we need to - * exclude part of the address from the hash - * calculation. - */ - if (fin->fin_out == 0) { - hv += src.in4.s_addr; - } else { - hv += dst.in4.s_addr; - } - hv += dport; - hv += sport; - } - tryagain++; - if (tryagain <= 2) { - WRITE_ENTER(&ipf_state); - goto retry_tcpudp; - } - } - fin->fin_flx |= oow; - break; - -#if 0 - case IPPROTO_GRE : - gre = fin->fin_dp; - if (GRE_REV(gre->gr_flags) == 1) { - hv += gre->gr_call; - } - /* FALLTHROUGH */ -#endif - default : - ifqp = NULL; - hvm = DOUBLE_HASH(hv); - READ_ENTER(&ipf_state); - for (isp = &ips_table[hvm]; ((is = *isp) != NULL); ) { - isp = &is->is_hnext; - if ((is->is_p != pr) || (is->is_v != v)) - continue; - is = fr_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); - if (is != NULL) { - ifq = &ips_iptq; - break; - } - } - if (is == NULL) { - RWLOCK_EXIT(&ipf_state); - } - break; - } - - if (is != NULL) { - if (((is->is_sti.tqe_flags & TQE_RULEBASED) != 0) && - (is->is_tqehead[fin->fin_rev] != NULL)) - ifq = is->is_tqehead[fin->fin_rev]; - if (ifq != NULL && ifqp != NULL) - *ifqp = ifq; - } - return is; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_updatestate */ -/* Returns: Nil */ -/* Parameters: fin(I) - pointer to packet information */ -/* is(I) - pointer to state table entry */ -/* Read Locks: ipf_state */ -/* */ -/* Updates packet and byte counters for a newly received packet. Seeds the */ -/* fragment cache with a new entry as required. */ -/* ------------------------------------------------------------------------ */ -void fr_updatestate(fin, is, ifq) -fr_info_t *fin; -ipstate_t *is; -ipftq_t *ifq; -{ - ipftqent_t *tqe; - int i, pass; - - i = (fin->fin_rev << 1) + fin->fin_out; - - /* - * For TCP packets, ifq == NULL. For all others, check if this new - * queue is different to the last one it was on and move it if so. - */ - tqe = &is->is_sti; - MUTEX_ENTER(&is->is_lock); - if ((tqe->tqe_flags & TQE_RULEBASED) != 0) - ifq = is->is_tqehead[fin->fin_rev]; - - if (ifq != NULL) - fr_movequeue(tqe, tqe->tqe_ifq, ifq); - - is->is_pkts[i]++; - is->is_bytes[i] += fin->fin_plen; - MUTEX_EXIT(&is->is_lock); - -#ifdef IPFILTER_SYNC - if (is->is_flags & IS_STATESYNC) - ipfsync_update(SMC_STATE, fin, is->is_sync); -#endif - - ATOMIC_INCL(ips_stats.iss_hits); - - fin->fin_fr = is->is_rule; - - /* - * If this packet is a fragment and the rule says to track fragments, - * then create a new fragment cache entry. - */ - pass = is->is_pass; - if ((fin->fin_flx & FI_FRAG) && FR_ISPASS(pass)) - (void) fr_newfrag(fin, pass ^ FR_KEEPSTATE); -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_checkstate */ -/* Returns: frentry_t* - NULL == search failed, */ -/* else pointer to rule for matching state */ -/* Parameters: ifp(I) - pointer to interface */ -/* passp(I) - pointer to filtering result flags */ -/* */ -/* Check if a packet is associated with an entry in the state table. */ -/* ------------------------------------------------------------------------ */ -frentry_t *fr_checkstate(fin, passp) -fr_info_t *fin; -u_32_t *passp; -{ - ipstate_t *is; - frentry_t *fr; - tcphdr_t *tcp; - ipftq_t *ifq; - u_int pass; - - if (fr_state_lock || (ips_list == NULL) || - (fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD))) - return NULL; - - is = NULL; - if ((fin->fin_flx & FI_TCPUDP) || - (fin->fin_fi.fi_p == IPPROTO_ICMP) -#ifdef USE_INET6 - || (fin->fin_fi.fi_p == IPPROTO_ICMPV6) -#endif - ) - tcp = fin->fin_dp; - else - tcp = NULL; - - /* - * Search the hash table for matching packet header info. - */ - ifq = NULL; - is = fin->fin_state; - if (is == NULL) - is = fr_stlookup(fin, tcp, &ifq); - switch (fin->fin_p) - { -#ifdef USE_INET6 - case IPPROTO_ICMPV6 : - if (is != NULL) - break; - if (fin->fin_v == 6) { - is = fr_checkicmp6matchingstate(fin); - if (is != NULL) - goto matched; - } - break; -#endif - case IPPROTO_ICMP : - if (is != NULL) - break; - /* - * No matching icmp state entry. Perhaps this is a - * response to another state entry. - */ - is = fr_checkicmpmatchingstate(fin); - if (is != NULL) - goto matched; - break; - case IPPROTO_TCP : - if (is == NULL) - break; - - if (is->is_pass & FR_NEWISN) { - if (fin->fin_out == 0) - fr_fixinisn(fin, is); - else if (fin->fin_out == 1) - fr_fixoutisn(fin, is); - } - break; - default : - if (fin->fin_rev) - ifq = &ips_udpacktq; - else - ifq = &ips_udptq; - break; - } - if (is == NULL) { - ATOMIC_INCL(ips_stats.iss_miss); - return NULL; - } - -matched: - fr = is->is_rule; - if (fr != NULL) { - if ((fin->fin_out == 0) && (fr->fr_nattag.ipt_num[0] != 0)) { - if (fin->fin_nattag == NULL) - return NULL; - if (fr_matchtag(&fr->fr_nattag, fin->fin_nattag) != 0) - return NULL; - } - (void) strncpy(fin->fin_group, fr->fr_group, FR_GROUPLEN); - fin->fin_icode = fr->fr_icode; - } - - fin->fin_rule = is->is_rulen; - pass = is->is_pass; - fr_updatestate(fin, is, ifq); - - fin->fin_state = is; - is->is_touched = fr_ticks; - MUTEX_ENTER(&is->is_lock); - is->is_ref++; - MUTEX_EXIT(&is->is_lock); - RWLOCK_EXIT(&ipf_state); - fin->fin_flx |= FI_STATE; - if ((pass & FR_LOGFIRST) != 0) - pass &= ~(FR_LOGFIRST|FR_LOG); - *passp = pass; - return fr; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_fixoutisn */ -/* Returns: Nil */ -/* Parameters: fin(I) - pointer to packet information */ -/* is(I) - pointer to master state structure */ -/* */ -/* Called only for outbound packets, adjusts the sequence number and the */ -/* TCP checksum to match that change. */ -/* ------------------------------------------------------------------------ */ -static void fr_fixoutisn(fin, is) -fr_info_t *fin; -ipstate_t *is; -{ - tcphdr_t *tcp; - int rev; - u_32_t seq; - - tcp = fin->fin_dp; - rev = fin->fin_rev; - if ((is->is_flags & IS_ISNSYN) != 0) { - if (rev == 0) { - seq = ntohl(tcp->th_seq); - seq += is->is_isninc[0]; - tcp->th_seq = htonl(seq); - fix_outcksum(fin, &tcp->th_sum, is->is_sumd[0]); - } - } - if ((is->is_flags & IS_ISNACK) != 0) { - if (rev == 1) { - seq = ntohl(tcp->th_seq); - seq += is->is_isninc[1]; - tcp->th_seq = htonl(seq); - fix_outcksum(fin, &tcp->th_sum, is->is_sumd[1]); - } - } -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_fixinisn */ -/* Returns: Nil */ -/* Parameters: fin(I) - pointer to packet information */ -/* is(I) - pointer to master state structure */ -/* */ -/* Called only for inbound packets, adjusts the acknowledge number and the */ -/* TCP checksum to match that change. */ -/* ------------------------------------------------------------------------ */ -static void fr_fixinisn(fin, is) -fr_info_t *fin; -ipstate_t *is; -{ - tcphdr_t *tcp; - int rev; - u_32_t ack; - - tcp = fin->fin_dp; - rev = fin->fin_rev; - if ((is->is_flags & IS_ISNSYN) != 0) { - if (rev == 1) { - ack = ntohl(tcp->th_ack); - ack -= is->is_isninc[0]; - tcp->th_ack = htonl(ack); - fix_incksum(fin, &tcp->th_sum, is->is_sumd[0]); - } - } - if ((is->is_flags & IS_ISNACK) != 0) { - if (rev == 0) { - ack = ntohl(tcp->th_ack); - ack -= is->is_isninc[1]; - tcp->th_ack = htonl(ack); - fix_incksum(fin, &tcp->th_sum, is->is_sumd[1]); - } - } -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_statesync */ -/* Returns: Nil */ -/* Parameters: ifp(I) - pointer to interface */ -/* */ -/* Walk through all state entries and if an interface pointer match is */ -/* found then look it up again, based on its name in case the pointer has */ -/* changed since last time. */ -/* */ -/* If ifp is passed in as being non-null then we are only doing updates for */ -/* existing, matching, uses of it. */ -/* ------------------------------------------------------------------------ */ -void fr_statesync(ifp) -void *ifp; -{ - ipstate_t *is; - int i; - - if (fr_running <= 0) - return; - - WRITE_ENTER(&ipf_state); - - if (fr_running <= 0) { - RWLOCK_EXIT(&ipf_state); - return; - } - - for (is = ips_list; is; is = is->is_next) { - /* - * Look up all the interface names in the state entry. - */ - for (i = 0; i < 4; i++) { - if (ifp == NULL || ifp == is->is_ifp[i]) - is->is_ifp[i] = fr_resolvenic(is->is_ifname[i], - is->is_v); - } - } - RWLOCK_EXIT(&ipf_state); -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_delstate */ -/* Returns: int - 0 = entry deleted, else reference count on struct */ -/* 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 int fr_delstate(is, why) -ipstate_t *is; -int why; -{ - - /* - * Since we want to delete this, remove it from the state table, - * where it can be found & used, first. - */ - if (is->is_phnext != NULL) { - *is->is_phnext = is->is_hnext; - if (is->is_hnext != NULL) - is->is_hnext->is_phnext = is->is_phnext; - if (ips_table[is->is_hv] == NULL) - ips_stats.iss_inuse--; - ips_stats.iss_bucketlen[is->is_hv]--; - - is->is_phnext = NULL; - is->is_hnext = NULL; - } - - /* - * Because ips_stats.iss_wild is a count of entries in the state - * table that have wildcard flags set, only decerement it once - * and do it here. - */ - if (is->is_flags & (SI_WILDP|SI_WILDA)) { - if (!(is->is_flags & SI_CLONED)) { - ATOMIC_DECL(ips_stats.iss_wild); - } - is->is_flags &= ~(SI_WILDP|SI_WILDA); - } - - /* - * Next, remove it from the timeout queue it is in. - */ - if (is->is_sti.tqe_ifq != NULL) - 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. How can this - * be? fr_state_flush() calls fr_delete() directly because it wants - * to empty the table out and if something has a hold on a state - * entry (such as ipfstat), it'll do the deref path that'll bring - * us back here to do the real delete & free. - */ - MUTEX_ENTER(&is->is_lock); - if (is->is_ref > 1) { - is->is_ref--; - MUTEX_EXIT(&is->is_lock); - return is->is_ref; - } - MUTEX_EXIT(&is->is_lock); - - is->is_ref = 0; - - 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 - - /* - * Now remove it from the linked list of known states - */ - 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 (ipstate_logging != 0 && why != 0) - ipstate_log(is, why); - - if (is->is_p == IPPROTO_TCP) - ips_stats.iss_fin++; - else - ips_stats.iss_expire++; - - if (is->is_rule != NULL) { - is->is_rule->fr_statecnt--; - (void) fr_derefrule(&is->is_rule); - } - - MUTEX_DESTROY(&is->is_lock); - KFREE(is); - ips_num--; - - return 0; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_timeoutstate */ -/* Returns: Nil */ -/* Parameters: Nil */ -/* */ -/* Slowly expire held state for thingslike UDP and ICMP. The algorithm */ -/* used here is to keep the queue sorted with the oldest things at the top */ -/* and the youngest at the bottom. So if the top one doesn't need to be */ -/* expired then neither will any under it. */ -/* ------------------------------------------------------------------------ */ -void fr_timeoutstate() -{ - ipftq_t *ifq, *ifqnext; - ipftqent_t *tqe, *tqn; - ipstate_t *is; - SPL_INT(s); - - SPL_NET(s); - WRITE_ENTER(&ipf_state); - for (ifq = ips_tqtqb; ifq != NULL; ifq = ifq->ifq_next) - for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { - if (tqe->tqe_die > fr_ticks) - break; - tqn = tqe->tqe_next; - is = tqe->tqe_parent; - fr_delstate(is, ISL_EXPIRE); - } - - for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) { - ifqnext = ifq->ifq_next; - - for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { - if (tqe->tqe_die > fr_ticks) - break; - tqn = tqe->tqe_next; - is = tqe->tqe_parent; - fr_delstate(is, ISL_EXPIRE); - } - } - - for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) { - ifqnext = ifq->ifq_next; - - if (((ifq->ifq_flags & IFQF_DELETE) != 0) && - (ifq->ifq_ref == 0)) { - fr_freetimeoutqueue(ifq); - } - } - - if (fr_state_doflush) { - (void) fr_state_flush(2, 0); - fr_state_doflush = 0; - } - - RWLOCK_EXIT(&ipf_state); - SPL_X(s); -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_state_flush */ -/* Returns: int - 0 == success, -1 == failure */ -/* Parameters: Nil */ -/* Write Locks: ipf_state */ -/* */ -/* Flush state tables. Three actions currently defined: */ -/* which == 0 : flush all state table entries */ -/* which == 1 : flush TCP connections which have started to close but are */ -/* stuck for some reason. */ -/* which == 2 : flush TCP connections which have been idle for a long time, */ -/* starting at > 4 days idle and working back in successive half-*/ -/* days to at most 12 hours old. If this fails to free enough */ -/* slots then work backwards in half hour slots to 30 minutes. */ -/* If that too fails, then work backwards in 30 second intervals */ -/* for the last 30 minutes to at worst 30 seconds idle. */ -/* ------------------------------------------------------------------------ */ -static int fr_state_flush(which, proto) -int which, proto; -{ - ipftq_t *ifq, *ifqnext; - ipftqent_t *tqe, *tqn; - ipstate_t *is, **isp; - int removed; - SPL_INT(s); - - removed = 0; - - SPL_NET(s); - - switch (which) - { - case 0 : - /* - * Style 0 flush removes everything... - */ - for (isp = &ips_list; ((is = *isp) != NULL); ) { - if ((proto != 0) && (is->is_v != proto)) { - isp = &is->is_next; - continue; - } - if (fr_delstate(is, ISL_FLUSH) == 0) - removed++; - else - isp = &is->is_next; - } - break; - - case 1 : - /* - * Since we're only interested in things that are closing, - * we can start with the appropriate timeout queue. - */ - for (ifq = ips_tqtqb + IPF_TCPS_CLOSE_WAIT; ifq != NULL; - ifq = ifq->ifq_next) { - - for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { - tqn = tqe->tqe_next; - is = tqe->tqe_parent; - if (is->is_p != IPPROTO_TCP) - break; - if (fr_delstate(is, ISL_EXPIRE) == 0) - removed++; - } - } - - /* - * Also need to look through the user defined queues. - */ - for (ifq = ips_utqe; ifq != NULL; ifq = ifqnext) { - ifqnext = ifq->ifq_next; - for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { - tqn = tqe->tqe_next; - is = tqe->tqe_parent; - if (is->is_p != IPPROTO_TCP) - continue; - - if ((is->is_state[0] > IPF_TCPS_ESTABLISHED) && - (is->is_state[1] > IPF_TCPS_ESTABLISHED)) { - if (fr_delstate(is, ISL_EXPIRE) == 0) - removed++; - } - } - } - break; - - case 2 : - break; - - /* - * Args 5-11 correspond to flushing those particular states - * for TCP connections. - */ - case IPF_TCPS_CLOSE_WAIT : - case IPF_TCPS_FIN_WAIT_1 : - case IPF_TCPS_CLOSING : - case IPF_TCPS_LAST_ACK : - case IPF_TCPS_FIN_WAIT_2 : - case IPF_TCPS_TIME_WAIT : - case IPF_TCPS_CLOSED : - tqn = ips_tqtqb[which].ifq_head; - while (tqn != NULL) { - tqe = tqn; - tqn = tqe->tqe_next; - is = tqe->tqe_parent; - if (fr_delstate(is, ISL_FLUSH) == 0) - removed++; - } - break; - - default : - if (which < 30) - break; - - /* - * Take a large arbitrary number to mean the number of seconds - * for which which consider to be the maximum value we'll allow - * the expiration to be. - */ - which = IPF_TTLVAL(which); - for (isp = &ips_list; ((is = *isp) != NULL); ) { - if ((proto == 0) || (is->is_v == proto)) { - if (fr_ticks - is->is_touched > which) { - if (fr_delstate(is, ISL_FLUSH) == 0) { - removed++; - continue; - } - } - } - isp = &is->is_next; - } - break; - } - - if (which != 2) { - SPL_X(s); - return removed; - } - - /* - * Asked to remove inactive entries because the table is full. - */ - if (fr_ticks - ips_last_force_flush > IPF_TTLVAL(5)) { - ips_last_force_flush = fr_ticks; - removed = ipf_queueflush(fr_state_flush_entry, ips_tqtqb, - ips_utqe); - } - - SPL_X(s); - return removed; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_state_flush_entry */ -/* Returns: int - 0 = entry deleted, else not deleted */ -/* Parameters: entry(I) - pointer to state structure to delete */ -/* Write Locks: ipf_state */ -/* */ -/* This function is a stepping stone between ipf_queueflush() and */ -/* fr_delstate(). It is used so we can provide a uniform interface via the */ -/* ipf_queueflush() function. */ -/* ------------------------------------------------------------------------ */ -static int fr_state_flush_entry(entry) -void *entry; -{ - return fr_delstate(entry, ISL_FLUSH); -} - - -/* ------------------------------------------------------------------------ */ -/* 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 */ -/* */ -/* A typical procession for a connection is as follows: */ -/* */ -/* +--------------+-------------------+ */ -/* | Side '0' | Side '1' | */ -/* +--------------+-------------------+ */ -/* | 0 -> 1 (SYN) | | */ -/* | | 0 -> 2 (SYN-ACK) | */ -/* | 1 -> 3 (ACK) | | */ -/* | | 2 -> 4 (ACK-PUSH) | */ -/* | 3 -> 4 (ACK) | | */ -/* | ... | ... | */ -/* | | 4 -> 6 (FIN-ACK) | */ -/* | 4 -> 5 (ACK) | | */ -/* | | 6 -> 6 (ACK-PUSH) | */ -/* | 5 -> 5 (ACK) | | */ -/* | 5 -> 8 (FIN) | | */ -/* | | 6 -> 10 (ACK) | */ -/* +--------------+-------------------+ */ -/* */ -/* 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_dlen - (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_LISTEN: /* 0 */ - if ((tcpflags & TH_OPENING) == TH_OPENING) { - /* - * 'dir' received an S and sends SA in - * response, LISTEN -> SYN_RECEIVED - */ - nstate = IPF_TCPS_SYN_RECEIVED; - rval = 1; - } else if ((tcpflags & TH_OPENING) == TH_SYN) { - /* 'dir' sent S, LISTEN -> SYN_SENT */ - nstate = IPF_TCPS_SYN_SENT; - rval = 1; - } - /* - * the next piece of code makes it possible to get - * already established connections into the state table - * after a restart or reload of the filter rules; this - * does not work when a strict 'flags S keep state' is - * used for tcp connections of course - */ - if (((flags & IS_TCPFSM) == 0) && - ((tcpflags & TH_ACKMASK) == TH_ACK)) { - /* - * we saw an A, guess 'dir' is in ESTABLISHED - * mode - */ - switch (ostate) - { - case IPF_TCPS_LISTEN : - case IPF_TCPS_SYN_RECEIVED : - nstate = IPF_TCPS_HALF_ESTAB; - rval = 1; - break; - case IPF_TCPS_HALF_ESTAB : - case IPF_TCPS_ESTABLISHED : - nstate = IPF_TCPS_ESTABLISHED; - rval = 1; - break; - default : - break; - } - } - /* - * TODO: besides regular ACK packets we can have other - * packets as well; it is yet to be determined how we - * should initialize the states in those cases - */ - break; - - case IPF_TCPS_SYN_SENT: /* 1 */ - if ((tcpflags & ~(TH_ECN|TH_CWR)) == TH_SYN) { - /* - * A retransmitted SYN packet. We do not reset - * the timeout here to fr_tcptimeout because a - * connection connect timeout does not renew - * after every packet that is sent. We need to - * set rval so as to indicate the packet has - * passed the check for its flags being valid - * in the TCP FSM. Setting rval to 2 has the - * result of not resetting the timeout. - */ - rval = 2; - } else if ((tcpflags & (TH_SYN|TH_FIN|TH_ACK)) == - TH_ACK) { - /* - * we see an A from 'dir' which is in SYN_SENT - * state: 'dir' sent an A in response to an SA - * which it received, SYN_SENT -> ESTABLISHED - */ - nstate = IPF_TCPS_ESTABLISHED; - rval = 1; - } else if (tcpflags & TH_FIN) { - /* - * we see an F from 'dir' which is in SYN_SENT - * state and wants to close its side of the - * connection; SYN_SENT -> FIN_WAIT_1 - */ - nstate = IPF_TCPS_FIN_WAIT_1; - rval = 1; - } else if ((tcpflags & TH_OPENING) == TH_OPENING) { - /* - * we see an SA from 'dir' which is already in - * SYN_SENT state, this means we have a - * simultaneous open; SYN_SENT -> SYN_RECEIVED - */ - nstate = IPF_TCPS_SYN_RECEIVED; - rval = 1; - } - break; - - case IPF_TCPS_SYN_RECEIVED: /* 2 */ - if ((tcpflags & (TH_SYN|TH_FIN|TH_ACK)) == TH_ACK) { - /* - * we see an A from 'dir' which was in - * SYN_RECEIVED state so it must now be in - * established state, SYN_RECEIVED -> - * ESTABLISHED - */ - nstate = IPF_TCPS_ESTABLISHED; - rval = 1; - } else if ((tcpflags & ~(TH_ECN|TH_CWR)) == - TH_OPENING) { - /* - * We see an SA from 'dir' which is already in - * SYN_RECEIVED state. - */ - rval = 2; - } else if (tcpflags & TH_FIN) { - /* - * we see an F from 'dir' which is in - * SYN_RECEIVED state and wants to close its - * side of the connection; SYN_RECEIVED -> - * FIN_WAIT_1 - */ - nstate = IPF_TCPS_FIN_WAIT_1; - rval = 1; - } - break; - - case IPF_TCPS_HALF_ESTAB: /* 3 */ - if (tcpflags & TH_FIN) { - nstate = IPF_TCPS_FIN_WAIT_1; - rval = 1; - } else if ((tcpflags & TH_ACKMASK) == TH_ACK) { - /* - * If we've picked up a connection in mid - * flight, we could be looking at a follow on - * packet from the same direction as the one - * that created this state. Recognise it but - * do not advance the entire connection's - * state. - */ - switch (ostate) - { - case IPF_TCPS_LISTEN : - case IPF_TCPS_SYN_SENT : - case IPF_TCPS_SYN_RECEIVED : - rval = 1; - break; - case IPF_TCPS_HALF_ESTAB : - case IPF_TCPS_ESTABLISHED : - nstate = IPF_TCPS_ESTABLISHED; - rval = 1; - break; - default : - break; - } - } - break; - - case IPF_TCPS_ESTABLISHED: /* 4 */ - rval = 1; - if (tcpflags & TH_FIN) { - /* - * 'dir' closed its side of the connection; - * this gives us a half-closed connection; - * ESTABLISHED -> FIN_WAIT_1 - */ - if (ostate == IPF_TCPS_FIN_WAIT_1) { - nstate = IPF_TCPS_CLOSING; - } else { - nstate = IPF_TCPS_FIN_WAIT_1; - } - } else if (tcpflags & TH_ACK) { - /* - * an ACK, should we exclude other flags here? - */ - if (ostate == IPF_TCPS_FIN_WAIT_1) { - /* - * We know the other side did an active - * close, so we are ACKing the recvd - * FIN packet (does the window matching - * code guarantee this?) and go into - * CLOSE_WAIT state; this gives us a - * half-closed connection - */ - nstate = IPF_TCPS_CLOSE_WAIT; - } else if (ostate < IPF_TCPS_CLOSE_WAIT) { - /* - * still a fully established - * connection reset timeout - */ - nstate = IPF_TCPS_ESTABLISHED; - } - } - break; - - case IPF_TCPS_CLOSE_WAIT: /* 5 */ - rval = 1; - if (tcpflags & TH_FIN) { - /* - * application closed and 'dir' sent a FIN, - * we're now going into LAST_ACK state - */ - nstate = IPF_TCPS_LAST_ACK; - } else { - /* - * we remain in CLOSE_WAIT because the other - * side has closed already and we did not - * close our side yet; reset timeout - */ - nstate = IPF_TCPS_CLOSE_WAIT; - } - break; - - case IPF_TCPS_FIN_WAIT_1: /* 6 */ - rval = 1; - if ((tcpflags & TH_ACK) && - ostate > IPF_TCPS_CLOSE_WAIT) { - /* - * if the other side is not active anymore - * it has sent us a FIN packet that we are - * ack'ing now with an ACK; this means both - * sides have now closed the connection and - * we go into TIME_WAIT - */ - /* - * XXX: how do we know we really are ACKing - * the FIN packet here? does the window code - * guarantee that? - */ - nstate = IPF_TCPS_TIME_WAIT; - } else { - /* - * we closed our side of the connection - * already but the other side is still active - * (ESTABLISHED/CLOSE_WAIT); continue with - * this half-closed connection - */ - nstate = IPF_TCPS_FIN_WAIT_1; - } - break; - - case IPF_TCPS_CLOSING: /* 7 */ - if ((tcpflags & (TH_FIN|TH_ACK)) == TH_ACK) { - nstate = IPF_TCPS_TIME_WAIT; - } - rval = 2; - break; - - case IPF_TCPS_LAST_ACK: /* 8 */ - 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: /* 9 */ - /* NOT USED */ - break; - - case IPF_TCPS_TIME_WAIT: /* 10 */ - /* we're in 2MSL timeout now */ - if (ostate == IPF_TCPS_LAST_ACK) { - nstate = IPF_TCPS_CLOSED; - } - rval = 1; - break; - - case IPF_TCPS_CLOSED: /* 11 */ - rval = 2; - 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 -#else - abort(); -#endif - break; - } - } - - /* - * If rval == 2 then do not update the queue position, but treat the - * packet as being ok. - */ - if (rval == 2) - rval = 1; - else if (rval == 1) { - tqe->tqe_state[dir] = nstate; - if ((tqe->tqe_flags & TQE_RULEBASED) == 0) - fr_movequeue(tqe, tqe->tqe_ifq, tqtab + nstate); - } - - return rval; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: ipstate_log */ -/* Returns: Nil */ -/* Parameters: is(I) - pointer to state structure */ -/* type(I) - type of log entry to create */ -/* */ -/* Creates a state table log entry using the state structure and type info. */ -/* passed in. Log packet/byte counts, source/destination address and other */ -/* protocol specific information. */ -/* ------------------------------------------------------------------------ */ -void ipstate_log(is, type) -struct ipstate *is; -u_int type; -{ -#ifdef IPFILTER_LOG - struct ipslog ipsl; - size_t sizes[1]; - void *items[1]; - int types[1]; - - /* - * Copy information out of the ipstate_t structure and into the - * structure used for logging. - */ - ipsl.isl_type = type; - ipsl.isl_pkts[0] = is->is_pkts[0] + is->is_icmppkts[0]; - ipsl.isl_bytes[0] = is->is_bytes[0]; - ipsl.isl_pkts[1] = is->is_pkts[1] + is->is_icmppkts[1]; - ipsl.isl_bytes[1] = is->is_bytes[1]; - ipsl.isl_pkts[2] = is->is_pkts[2] + is->is_icmppkts[2]; - ipsl.isl_bytes[2] = is->is_bytes[2]; - ipsl.isl_pkts[3] = is->is_pkts[3] + is->is_icmppkts[3]; - ipsl.isl_bytes[3] = is->is_bytes[3]; - ipsl.isl_src = is->is_src; - ipsl.isl_dst = is->is_dst; - ipsl.isl_p = is->is_p; - ipsl.isl_v = is->is_v; - ipsl.isl_flags = is->is_flags; - ipsl.isl_tag = is->is_tag; - ipsl.isl_rulen = is->is_rulen; - (void) strncpy(ipsl.isl_group, is->is_group, FR_GROUPLEN); - - if (ipsl.isl_p == IPPROTO_TCP || ipsl.isl_p == IPPROTO_UDP) { - ipsl.isl_sport = is->is_sport; - ipsl.isl_dport = is->is_dport; - if (ipsl.isl_p == IPPROTO_TCP) { - ipsl.isl_state[0] = is->is_state[0]; - ipsl.isl_state[1] = is->is_state[1]; - } - } else if (ipsl.isl_p == IPPROTO_ICMP) { - ipsl.isl_itype = is->is_icmp.ici_type; - } else if (ipsl.isl_p == IPPROTO_ICMPV6) { - ipsl.isl_itype = is->is_icmp.ici_type; - } else { - ipsl.isl_ps.isl_filler[0] = 0; - ipsl.isl_ps.isl_filler[1] = 0; - } - - items[0] = &ipsl; - sizes[0] = sizeof(ipsl); - types[0] = 0; - - if (ipllog(IPL_LOGSTATE, NULL, items, sizes, types, 1)) { - ATOMIC_INCL(ips_stats.iss_logged); - } else { - ATOMIC_INCL(ips_stats.iss_logfail); - } -#endif -} - - -#ifdef USE_INET6 -/* ------------------------------------------------------------------------ */ -/* Function: fr_checkicmp6matchingstate */ -/* Returns: ipstate_t* - NULL == no match found, */ -/* else pointer to matching state entry */ -/* Parameters: fin(I) - pointer to packet information */ -/* Locks: NULL == no locks, else Read Lock on ipf_state */ -/* */ -/* If we've got an ICMPv6 error message, using the information stored in */ -/* the ICMPv6 packet, look for a matching state table entry. */ -/* ------------------------------------------------------------------------ */ -static ipstate_t *fr_checkicmp6matchingstate(fin) -fr_info_t *fin; -{ - struct icmp6_hdr *ic6, *oic; - int type, backward, i; - ipstate_t *is, **isp; - u_short sport, dport; - i6addr_t dst, src; - u_short savelen; - icmpinfo_t *ic; - fr_info_t ofin; - tcphdr_t *tcp; - ip6_t *oip6; - u_char pr; - u_int hv; - - /* - * Does it at least have the return (basic) IP header ? - * Is it an actual recognised ICMP error type? - * Only a basic IP header (no options) should be with - * an ICMP error header. - */ - if ((fin->fin_v != 6) || (fin->fin_plen < ICMP6ERR_MINPKTLEN) || - !(fin->fin_flx & FI_ICMPERR)) - return NULL; - - ic6 = fin->fin_dp; - type = ic6->icmp6_type; - - oip6 = (ip6_t *)((char *)ic6 + ICMPERR_ICMPHLEN); - if (fin->fin_plen < sizeof(*oip6)) - return NULL; - - bcopy((char *)fin, (char *)&ofin, sizeof(*fin)); - ofin.fin_v = 6; - ofin.fin_ifp = fin->fin_ifp; - ofin.fin_out = !fin->fin_out; - ofin.fin_m = NULL; /* if dereferenced, panic XXX */ - ofin.fin_mp = NULL; /* if dereferenced, panic XXX */ - - /* - * We make a fin entry to be able to feed it to - * matchsrcdst. Note that not all fields are necessary - * but this is the cleanest way. Note further we fill - * in fin_mp such that if someone uses it we'll get - * a kernel panic. fr_matchsrcdst does not use this. - * - * watch out here, as ip is in host order and oip6 in network - * order. Any change we make must be undone afterwards. - */ - savelen = oip6->ip6_plen; - oip6->ip6_plen = fin->fin_dlen - ICMPERR_ICMPHLEN; - ofin.fin_flx = FI_NOCKSUM; - ofin.fin_ip = (ip_t *)oip6; - (void) fr_makefrip(sizeof(*oip6), (ip_t *)oip6, &ofin); - ofin.fin_flx &= ~(FI_BAD|FI_SHORT); - oip6->ip6_plen = savelen; - - if (oip6->ip6_nxt == IPPROTO_ICMPV6) { - oic = (struct icmp6_hdr *)(oip6 + 1); - /* - * an ICMP error can only be generated as a result of an - * ICMP query, not as the response on an ICMP error - * - * XXX theoretically ICMP_ECHOREP and the other reply's are - * ICMP query's as well, but adding them here seems strange XXX - */ - if (!(oic->icmp6_type & ICMP6_INFOMSG_MASK)) - return NULL; - - /* - * perform a lookup of the ICMP packet in the state table - */ - hv = (pr = oip6->ip6_nxt); - src.in6 = oip6->ip6_src; - hv += src.in4.s_addr; - dst.in6 = oip6->ip6_dst; - hv += dst.in4.s_addr; - hv += oic->icmp6_id; - hv += oic->icmp6_seq; - hv = DOUBLE_HASH(hv); - - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { - ic = &is->is_icmp; - isp = &is->is_hnext; - if ((is->is_p == pr) && - !(is->is_pass & FR_NOICMPERR) && - (oic->icmp6_id == ic->ici_id) && - (oic->icmp6_seq == ic->ici_seq) && - (is = fr_matchsrcdst(&ofin, is, &src, - &dst, NULL, FI_ICMPCMP))) { - /* - * in the state table ICMP query's are stored - * with the type of the corresponding ICMP - * response. Correct here - */ - if (((ic->ici_type == ICMP6_ECHO_REPLY) && - (oic->icmp6_type == ICMP6_ECHO_REQUEST)) || - (ic->ici_type - 1 == oic->icmp6_type )) { - ips_stats.iss_hits++; - backward = IP6_NEQ(&is->is_dst, &src); - fin->fin_rev = !backward; - i = (backward << 1) + fin->fin_out; - is->is_icmppkts[i]++; - return is; - } - } - } - RWLOCK_EXIT(&ipf_state); - return NULL; - } - - hv = (pr = oip6->ip6_nxt); - src.in6 = oip6->ip6_src; - hv += src.i6[0]; - hv += src.i6[1]; - hv += src.i6[2]; - hv += src.i6[3]; - dst.in6 = oip6->ip6_dst; - hv += dst.i6[0]; - hv += dst.i6[1]; - hv += dst.i6[2]; - hv += dst.i6[3]; - - if ((oip6->ip6_nxt == IPPROTO_TCP) || (oip6->ip6_nxt == IPPROTO_UDP)) { - tcp = (tcphdr_t *)(oip6 + 1); - dport = tcp->th_dport; - sport = tcp->th_sport; - hv += dport; - hv += sport; - } else - tcp = NULL; - hv = DOUBLE_HASH(hv); - - READ_ENTER(&ipf_state); - for (isp = &ips_table[hv]; ((is = *isp) != NULL); ) { - isp = &is->is_hnext; - /* - * Only allow this icmp though if the - * encapsulated packet was allowed through the - * other way around. Note that the minimal amount - * of info present does not allow for checking against - * tcp internals such as seq and ack numbers. - */ - if ((is->is_p != pr) || (is->is_v != 6) || - (is->is_pass & FR_NOICMPERR)) - continue; - is = fr_matchsrcdst(&ofin, is, &src, &dst, tcp, FI_ICMPCMP); - if (is != NULL) { - ips_stats.iss_hits++; - backward = IP6_NEQ(&is->is_dst, &src); - fin->fin_rev = !backward; - i = (backward << 1) + fin->fin_out; - is->is_icmppkts[i]++; - /* - * we deliberately do not touch the timeouts - * for the accompanying state table entry. - * It remains to be seen if that is correct. XXX - */ - return is; - } - } - RWLOCK_EXIT(&ipf_state); - return NULL; -} -#endif - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_sttab_init */ -/* Returns: Nil */ -/* Parameters: tqp(I) - pointer to an array of timeout queues for TCP */ -/* */ -/* Initialise the array of timeout queues for TCP. */ -/* ------------------------------------------------------------------------ */ -void fr_sttab_init(tqp) -ipftq_t *tqp; -{ - int i; - - for (i = IPF_TCP_NSTATES - 1; i >= 0; i--) { - tqp[i].ifq_ttl = 0; - tqp[i].ifq_ref = 1; - tqp[i].ifq_head = NULL; - tqp[i].ifq_tail = &tqp[i].ifq_head; - tqp[i].ifq_next = tqp + i + 1; - MUTEX_INIT(&tqp[i].ifq_lock, "ipftq tcp tab"); - } - tqp[IPF_TCP_NSTATES - 1].ifq_next = NULL; - tqp[IPF_TCPS_CLOSED].ifq_ttl = fr_tcpclosed; - tqp[IPF_TCPS_LISTEN].ifq_ttl = fr_tcptimeout; - tqp[IPF_TCPS_SYN_SENT].ifq_ttl = fr_tcptimeout; - tqp[IPF_TCPS_SYN_RECEIVED].ifq_ttl = fr_tcptimeout; - tqp[IPF_TCPS_ESTABLISHED].ifq_ttl = fr_tcpidletimeout; - tqp[IPF_TCPS_CLOSE_WAIT].ifq_ttl = fr_tcphalfclosed; - tqp[IPF_TCPS_FIN_WAIT_1].ifq_ttl = fr_tcphalfclosed; - tqp[IPF_TCPS_CLOSING].ifq_ttl = fr_tcptimeout; - tqp[IPF_TCPS_LAST_ACK].ifq_ttl = fr_tcplastack; - tqp[IPF_TCPS_FIN_WAIT_2].ifq_ttl = fr_tcpclosewait; - tqp[IPF_TCPS_TIME_WAIT].ifq_ttl = fr_tcptimewait; - 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. */ -/* */ -/* This function is only called when cleaning up after increasing is_ref by */ -/* one earlier in the 'code path' so if is_ref is 1 when entering, we do */ -/* have an orphan, otherwise not. However there is a possible race between */ -/* the entry being deleted via flushing with an ioctl call (that calls the */ -/* delete function directly) and the tail end of packet processing so we */ -/* need to grab is_lock before doing the check to synchronise the two code */ -/* paths. */ -/* */ -/* 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(isp) -ipstate_t **isp; -{ - ipstate_t *is; - - is = *isp; - *isp = NULL; - - MUTEX_ENTER(&is->is_lock); - if (is->is_ref > 1) { - is->is_ref--; - MUTEX_EXIT(&is->is_lock); -#ifndef _KERNEL - if ((is->is_sti.tqe_state[0] > IPF_TCPS_ESTABLISHED) || - (is->is_sti.tqe_state[1] > IPF_TCPS_ESTABLISHED)) { - fr_delstate(is, ISL_ORPHAN); - } -#endif - return; - } - MUTEX_EXIT(&is->is_lock); - - WRITE_ENTER(&ipf_state); - fr_delstate(is, ISL_EXPIRE); - 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; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_stateiter */ -/* Returns: int - 0 == success, else error */ -/* Parameters: token(I) - pointer to ipftoken structure */ -/* itp(I) - pointer to ipfgeniter structure */ -/* */ -/* This function handles the SIOCGENITER ioctl for the state tables and */ -/* walks through the list of entries in the state table list (ips_list.) */ -/* ------------------------------------------------------------------------ */ -static int fr_stateiter(token, itp) -ipftoken_t *token; -ipfgeniter_t *itp; -{ - ipstate_t *is, *next, zero; - int error, count; - char *dst; - - if (itp->igi_data == NULL) - return EFAULT; - - if (itp->igi_nitems < 1) - return ENOSPC; - - if (itp->igi_type != IPFGENITER_STATE) - return EINVAL; - - is = token->ipt_data; - if (is == (void *)-1) { - ipf_freetoken(token); - return ESRCH; - } - - error = 0; - dst = itp->igi_data; - - READ_ENTER(&ipf_state); - if (is == NULL) { - next = ips_list; - } else { - next = is->is_next; - } - - count = itp->igi_nitems; - for (;;) { - if (next != NULL) { - /* - * If we find a state entry to use, bump its - * reference count so that it can be used for - * is_next when we come back. - */ - if (count == 1) { - MUTEX_ENTER(&next->is_lock); - next->is_ref++; - MUTEX_EXIT(&next->is_lock); - token->ipt_data = next; - } - } else { - bzero(&zero, sizeof(zero)); - next = &zero; - count = 1; - token->ipt_data = NULL; - } - RWLOCK_EXIT(&ipf_state); - - /* - * This should arguably be via fr_outobj() so that the state - * structure can (if required) be massaged going out. - */ - error = COPYOUT(next, dst, sizeof(*next)); - if (error != 0) - error = EFAULT; - if ((count == 1) || (error != 0)) - break; - - dst += sizeof(*next); - count--; - - READ_ENTER(&ipf_state); - next = next->is_next; - } - - if (is != NULL) { - fr_statederef(&is); - } - - return error; -} - - -/* ------------------------------------------------------------------------ */ -/* Function: fr_stgettable */ -/* Returns: int - 0 = success, else error */ -/* Parameters: data(I) - pointer to ioctl data */ -/* */ -/* This function handles ioctl requests for tables of state information. */ -/* At present the only table it deals with is the hash bucket statistics. */ -/* ------------------------------------------------------------------------ */ -static int fr_stgettable(data) -char *data; -{ - ipftable_t table; - int error; - - error = fr_inobj(data, &table, IPFOBJ_GTABLE); - if (error != 0) - return error; - - if (table.ita_type != IPFTABLE_BUCKETS) - return EINVAL; - - error = COPYOUT(ips_stats.iss_bucketlen, table.ita_table, - fr_statesize * sizeof(u_long)); - if (error != 0) - error = EFAULT; - return error; -} |