/* $NetBSD: ip_state.c,v 1.12 2020/04/18 17:02:00 christos Exp $ */ /* * Copyright (C) 2012 by Darren Reed. * * See the IPFILTER.LICENCE file for details on licencing. * * Id: ip_state.c,v 1.1.1.2 2012/07/22 13:45:37 darrenr Exp */ #if defined(KERNEL) || defined(_KERNEL) # undef KERNEL # undef _KERNEL # define KERNEL 1 # define _KERNEL 1 #endif #include #include #include #include #if defined(_KERNEL) && defined(__FreeBSD_version) && \ (__FreeBSD_version >= 400000) && !defined(KLD_MODULE) #include "opt_inet6.h" #endif #if !defined(_KERNEL) && !defined(__KERNEL__) # include # include # include # define _KERNEL # ifdef __OpenBSD__ struct file; # endif # include # undef _KERNEL #endif #if defined(_KERNEL) && (__FreeBSD_version >= 220000) # include # include #else # include #endif #include #if !defined(linux) # include #endif #include #if defined(_KERNEL) # include # if !defined(__SVR4) && !defined(__svr4__) # include # endif #endif #if defined(__SVR4) || defined(__svr4__) # include # include # ifdef _KERNEL # include # endif # include # include #endif #include #ifdef sun # include #endif #include #include #include #include #if !defined(__hpux) && !defined(linux) # include #endif #include #include #if !defined(_KERNEL) # include "ipf.h" #endif #include "netinet/ip_compat.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" #include "netinet/ip_lookup.h" #include "netinet/ip_dstlist.h" #include "netinet/ip_sync.h" #ifdef USE_INET6 #include #endif #if FREEBSD_GE_REV(300000) # include # if defined(_KERNEL) && !defined(IPFILTER_LKM) # include # include # endif #endif /* END OF INCLUDES */ #if !defined(lint) #if defined(__NetBSD__) #include __KERNEL_RCSID(0, "$NetBSD: ip_state.c,v 1.12 2020/04/18 17:02:00 christos Exp $"); #else 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 1.1.1.2 2012/07/22 13:45:37 darrenr Exp"; #endif #endif static const ipftuneable_t ipf_state_tuneables[] = { { { (void *)offsetof(ipf_state_softc_t, ipf_state_max) }, "state_max", 1, 0x7fffffff, stsizeof(ipf_state_softc_t, ipf_state_max), 0, NULL, NULL }, { { (void *)offsetof(ipf_state_softc_t, ipf_state_size) }, "state_size", 1, 0x7fffffff, stsizeof(ipf_state_softc_t, ipf_state_size), 0, NULL, ipf_state_rehash }, { { (void *)offsetof(ipf_state_softc_t, ipf_state_lock) }, "state_lock", 0, 1, stsizeof(ipf_state_softc_t, ipf_state_lock), IPFT_RDONLY, NULL, NULL }, { { (void *)offsetof(ipf_state_softc_t, ipf_state_maxbucket) }, "state_maxbucket", 1, 0x7fffffff, stsizeof(ipf_state_softc_t, ipf_state_maxbucket), 0, NULL, NULL }, { { (void *)offsetof(ipf_state_softc_t, ipf_state_logging) }, "state_logging",0, 1, stsizeof(ipf_state_softc_t, ipf_state_logging), 0, NULL, NULL }, { { (void *)offsetof(ipf_state_softc_t, ipf_state_wm_high) }, "state_wm_high",2, 100, stsizeof(ipf_state_softc_t, ipf_state_wm_high), 0, NULL, NULL }, { { (void *)offsetof(ipf_state_softc_t, ipf_state_wm_low) }, "state_wm_low", 1, 99, stsizeof(ipf_state_softc_t, ipf_state_wm_low), 0, NULL, NULL }, { { (void *)offsetof(ipf_state_softc_t, ipf_state_wm_freq) }, "state_wm_freq",2, 999999, stsizeof(ipf_state_softc_t, ipf_state_wm_freq), 0, NULL, NULL }, { { NULL }, NULL, 0, 0, 0, 0, NULL, NULL } }; #define SINCL(x) ATOMIC_INCL(softs->x) #define SBUMP(x) (softs->x)++ #define SBUMPD(x, y) do { (softs->x.y)++; DT(y); } while (0) #define SBUMPDX(x, y, z)do { (softs->x.y)++; DT(z); } while (0) #ifdef USE_INET6 static ipstate_t *ipf_checkicmp6matchingstate(fr_info_t *); #endif static int ipf_allowstateicmp(fr_info_t *, ipstate_t *, i6addr_t *); static ipstate_t *ipf_matchsrcdst(fr_info_t *, ipstate_t *, i6addr_t *, i6addr_t *, tcphdr_t *, u_32_t); static ipstate_t *ipf_checkicmpmatchingstate(fr_info_t *); static int ipf_state_flush_entry(ipf_main_softc_t *, void *); static ips_stat_t *ipf_state_stats(ipf_main_softc_t *); static int ipf_state_del(ipf_main_softc_t *, ipstate_t *, int); static int ipf_state_remove(ipf_main_softc_t *, void *); static int ipf_state_match(ipstate_t *is1, ipstate_t *is2); static int ipf_state_matchaddresses(ipstate_t *is1, ipstate_t *is2); static int ipf_state_matchipv4addrs(ipstate_t *is1, ipstate_t *is2); static int ipf_state_matchipv6addrs(ipstate_t *is1, ipstate_t *is2); static int ipf_state_matchisps(ipstate_t *is1, ipstate_t *is2); static int ipf_state_matchports(udpinfo_t *is1, udpinfo_t *is2); static int ipf_state_matcharray(ipstate_t *, int *, u_long); static void ipf_ipsmove(ipf_state_softc_t *, ipstate_t *, u_int); static int ipf_state_tcp(ipf_main_softc_t *, ipf_state_softc_t *, fr_info_t *, tcphdr_t *, ipstate_t *); static int ipf_tcpoptions(ipf_state_softc_t *, fr_info_t *, tcphdr_t *, tcpdata_t *); static ipstate_t *ipf_state_clone(fr_info_t *, tcphdr_t *, ipstate_t *); static void ipf_fixinisn(fr_info_t *, ipstate_t *); static void ipf_fixoutisn(fr_info_t *, ipstate_t *); static void ipf_checknewisn(fr_info_t *, ipstate_t *); static int ipf_state_iter(ipf_main_softc_t *, ipftoken_t *, ipfgeniter_t *, ipfobj_t *); static int ipf_state_gettable(ipf_main_softc_t *, ipf_state_softc_t *, char *); static int ipf_state_tcpinwindow(struct fr_info *, struct tcpdata *, struct tcpdata *, tcphdr_t *, int); static int ipf_state_getent(ipf_main_softc_t *, ipf_state_softc_t *, void *); static int ipf_state_putent(ipf_main_softc_t *, ipf_state_softc_t *, void *); #define ONE_DAY IPF_TTLVAL(1 * 86400) /* 1 day */ #define FIVE_DAYS (5 * ONE_DAY) #define DOUBLE_HASH(x) (((x) + softs->ipf_state_seed[(x) % \ softs->ipf_state_size]) % softs->ipf_state_size) /* ------------------------------------------------------------------------ */ /* Function: ipf_state_main_load */ /* Returns: int - 0 == success, -1 == failure */ /* Parameters: Nil */ /* */ /* A null-op function that exists as a placeholder so that the flow in */ /* other functions is obvious. */ /* ------------------------------------------------------------------------ */ int ipf_state_main_load(void) { return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_main_unload */ /* Returns: int - 0 == success, -1 == failure */ /* Parameters: Nil */ /* */ /* A null-op function that exists as a placeholder so that the flow in */ /* other functions is obvious. */ /* ------------------------------------------------------------------------ */ int ipf_state_main_unload(void) { return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_soft_create */ /* Returns: void * - NULL = failure, else pointer to soft context */ /* Parameters: softc(I) - pointer to soft context main structure */ /* */ /* Create a new state soft context structure and populate it with the list */ /* of tunables and other default settings. */ /* ------------------------------------------------------------------------ */ void * ipf_state_soft_create(ipf_main_softc_t *softc) { ipf_state_softc_t *softs; KMALLOC(softs, ipf_state_softc_t *); if (softs == NULL) return NULL; bzero((char *)softs, sizeof(*softs)); softs->ipf_state_tune = ipf_tune_array_copy(softs, sizeof(ipf_state_tuneables), ipf_state_tuneables); if (softs->ipf_state_tune == NULL) { ipf_state_soft_destroy(softc, softs); return NULL; } if (ipf_tune_array_link(softc, softs->ipf_state_tune) == -1) { ipf_state_soft_destroy(softc, softs); return NULL; } #ifdef IPFILTER_LOG softs->ipf_state_logging = 1; #else softs->ipf_state_logging = 0; #endif softs->ipf_state_size = IPSTATE_SIZE, softs->ipf_state_maxbucket = 0; softs->ipf_state_wm_freq = IPF_TTLVAL(10); softs->ipf_state_max = IPSTATE_MAX; softs->ipf_state_wm_last = 0; softs->ipf_state_wm_high = 99; softs->ipf_state_wm_low = 90; softs->ipf_state_inited = 0; softs->ipf_state_lock = 0; softs->ipf_state_doflush = 0; return softs; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_soft_destroy */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* arg(I) - pointer to local context to use */ /* */ /* Undo only what we did in soft create: unlink and free the tunables and */ /* free the soft context structure itself. */ /* ------------------------------------------------------------------------ */ void ipf_state_soft_destroy(ipf_main_softc_t *softc, void *arg) { ipf_state_softc_t *softs = arg; if (softs->ipf_state_tune != NULL) { ipf_tune_array_unlink(softc, softs->ipf_state_tune); KFREES(softs->ipf_state_tune, sizeof(ipf_state_tuneables)); softs->ipf_state_tune = NULL; } KFREE(softs); } static void * ipf_state_seed_alloc(u_int state_size, u_int state_max) { u_int i; u_long *state_seed; KMALLOCS(state_seed, u_long *, state_size * sizeof(*state_seed)); if (state_seed == NULL) return NULL; for (i = 0; i < state_size; i++) { /* * XXX - ipf_state_seed[X] should be a random number of sorts. */ #if !defined(NEED_LOCAL_RAND) && defined(_KERNEL) state_seed[i] = cprng_fast32(); #else state_seed[i] = ((u_long)state_seed + i) * state_size; state_seed[i] ^= 0xa5a55a5a; state_seed[i] *= (u_long)state_seed; state_seed[i] ^= 0x5a5aa5a5; state_seed[i] *= state_max; #endif } return state_seed; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_soft_init */ /* Returns: int - 0 == success, -1 == failure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* arg(I) - pointer to local context to use */ /* */ /* Initialise the state soft context structure so it is ready for use. */ /* This involves: */ /* - allocating a hash table and zero'ing it out */ /* - building a secondary table of seeds for double hashing to make it more */ /* difficult to attempt to attack the hash table itself (for DoS) */ /* - initialise all of the timeout queues, including a table for TCP, some */ /* pairs of query/response for UDP and other IP protocols (typically the */ /* reply queue has a shorter timeout than the query) */ /* ------------------------------------------------------------------------ */ int ipf_state_soft_init(ipf_main_softc_t *softc, void *arg) { ipf_state_softc_t *softs = arg; int i; KMALLOCS(softs->ipf_state_table, ipstate_t **, softs->ipf_state_size * sizeof(ipstate_t *)); if (softs->ipf_state_table == NULL) return -1; bzero((char *)softs->ipf_state_table, softs->ipf_state_size * sizeof(ipstate_t *)); softs->ipf_state_seed = ipf_state_seed_alloc(softs->ipf_state_size, softs->ipf_state_max); if (softs->ipf_state_seed == NULL) return -2; KMALLOCS(softs->ipf_state_stats.iss_bucketlen, u_int *, softs->ipf_state_size * sizeof(u_int)); if (softs->ipf_state_stats.iss_bucketlen == NULL) return -3; bzero((char *)softs->ipf_state_stats.iss_bucketlen, softs->ipf_state_size * sizeof(u_int)); if (softs->ipf_state_maxbucket == 0) { for (i = softs->ipf_state_size; i > 0; i >>= 1) softs->ipf_state_maxbucket++; softs->ipf_state_maxbucket *= 2; } ipf_sttab_init(softc, softs->ipf_state_tcptq); softs->ipf_state_stats.iss_tcptab = softs->ipf_state_tcptq; softs->ipf_state_tcptq[IPF_TCP_NSTATES - 1].ifq_next = &softs->ipf_state_udptq; IPFTQ_INIT(&softs->ipf_state_udptq, softc->ipf_udptimeout, "ipftq udp tab"); softs->ipf_state_udptq.ifq_next = &softs->ipf_state_udpacktq; IPFTQ_INIT(&softs->ipf_state_udpacktq, softc->ipf_udpacktimeout, "ipftq udpack tab"); softs->ipf_state_udpacktq.ifq_next = &softs->ipf_state_icmptq; IPFTQ_INIT(&softs->ipf_state_icmptq, softc->ipf_icmptimeout, "ipftq icmp tab"); softs->ipf_state_icmptq.ifq_next = &softs->ipf_state_icmpacktq; IPFTQ_INIT(&softs->ipf_state_icmpacktq, softc->ipf_icmpacktimeout, "ipftq icmpack tab"); softs->ipf_state_icmpacktq.ifq_next = &softs->ipf_state_iptq; IPFTQ_INIT(&softs->ipf_state_iptq, softc->ipf_iptimeout, "ipftq iptimeout tab"); softs->ipf_state_iptq.ifq_next = &softs->ipf_state_pending; IPFTQ_INIT(&softs->ipf_state_pending, IPF_HZ_DIVIDE, "ipftq pending"); softs->ipf_state_pending.ifq_next = &softs->ipf_state_deletetq; IPFTQ_INIT(&softs->ipf_state_deletetq, 1, "ipftq delete"); softs->ipf_state_deletetq.ifq_next = NULL; MUTEX_INIT(&softs->ipf_stinsert, "ipf state insert mutex"); softs->ipf_state_wm_last = softc->ipf_ticks; softs->ipf_state_inited = 1; return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_soft_fini */ /* Returns: int - 0 = success, -1 = failure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* arg(I) - pointer to local context to use */ /* */ /* Release and destroy any resources acquired or initialised so that */ /* IPFilter can be unloaded or re-initialised. */ /* ------------------------------------------------------------------------ */ int ipf_state_soft_fini(ipf_main_softc_t *softc, void *arg) { ipf_state_softc_t *softs = arg; ipftq_t *ifq, *ifqnext; ipstate_t *is; while ((is = softs->ipf_state_list) != NULL) ipf_state_del(softc, is, ISL_UNLOAD); /* * Proxy timeout queues are not cleaned here because although they * exist on the state list, appr_unload is called after * ipf_state_unload 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 complication. */ for (ifq = softs->ipf_state_usertq; ifq != NULL; ifq = ifqnext) { ifqnext = ifq->ifq_next; if (ipf_deletetimeoutqueue(ifq) == 0) ipf_freetimeoutqueue(softc, ifq); } softs->ipf_state_stats.iss_inuse = 0; softs->ipf_state_stats.iss_active = 0; if (softs->ipf_state_inited == 1) { softs->ipf_state_inited = 0; ipf_sttab_destroy(softs->ipf_state_tcptq); MUTEX_DESTROY(&softs->ipf_state_udptq.ifq_lock); MUTEX_DESTROY(&softs->ipf_state_icmptq.ifq_lock); MUTEX_DESTROY(&softs->ipf_state_udpacktq.ifq_lock); MUTEX_DESTROY(&softs->ipf_state_icmpacktq.ifq_lock); MUTEX_DESTROY(&softs->ipf_state_iptq.ifq_lock); MUTEX_DESTROY(&softs->ipf_state_deletetq.ifq_lock); MUTEX_DESTROY(&softs->ipf_state_pending.ifq_lock); MUTEX_DESTROY(&softs->ipf_stinsert); } if (softs->ipf_state_table != NULL) { KFREES(softs->ipf_state_table, softs->ipf_state_size * sizeof(*softs->ipf_state_table)); softs->ipf_state_table = NULL; } if (softs->ipf_state_seed != NULL) { KFREES(softs->ipf_state_seed, softs->ipf_state_size * sizeof(*softs->ipf_state_seed)); softs->ipf_state_seed = NULL; } if (softs->ipf_state_stats.iss_bucketlen != NULL) { KFREES(softs->ipf_state_stats.iss_bucketlen, softs->ipf_state_size * sizeof(u_int)); softs->ipf_state_stats.iss_bucketlen = NULL; } return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_set_lock */ /* Returns: Nil */ /* Parameters: arg(I) - pointer to local context to use */ /* tmp(I) - new value for lock */ /* */ /* Stub function that allows for external manipulation of ipf_state_lock */ /* ------------------------------------------------------------------------ */ void ipf_state_setlock(void *arg, int tmp) { ipf_state_softc_t *softs = arg; softs->ipf_state_lock = tmp; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_stats */ /* Returns: ips_state_t* - pointer to state stats structure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* */ /* Put all the current numbers and pointers into a single struct and return */ /* a pointer to it. */ /* ------------------------------------------------------------------------ */ static ips_stat_t * ipf_state_stats(ipf_main_softc_t *softc) { ipf_state_softc_t *softs = softc->ipf_state_soft; ips_stat_t *issp = &softs->ipf_state_stats; issp->iss_state_size = softs->ipf_state_size; issp->iss_state_max = softs->ipf_state_max; issp->iss_table = softs->ipf_state_table; issp->iss_list = softs->ipf_state_list; issp->iss_ticks = softc->ipf_ticks; #ifdef IPFILTER_LOGGING issp->iss_log_ok = ipf_log_logok(softc, IPF_LOGSTATE); issp->iss_log_fail = ipf_log_failures(softc, IPF_LOGSTATE); #else issp->iss_log_ok = 0; issp->iss_log_fail = 0; #endif return issp; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_remove */ /* Returns: int - 0 == success, != 0 == failure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* 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 ipf_state_remove(ipf_main_softc_t *softc, void *data) { ipf_state_softc_t *softs = softc->ipf_state_soft; ipstate_t *sp, st; int error; sp = &st; error = ipf_inobj(softc, data, NULL, &st, IPFOBJ_IPSTATE); if (error) return EFAULT; WRITE_ENTER(&softc->ipf_state); for (sp = softs->ipf_state_list; sp; sp = sp->is_next) if ((sp->is_p == st.is_p) && (sp->is_v == st.is_v) && !bcmp((void *)&sp->is_src, (void *)&st.is_src, sizeof(st.is_src)) && !bcmp((void *)&sp->is_dst, (void *)&st.is_src, sizeof(st.is_dst)) && !bcmp((void *)&sp->is_ps, (void *)&st.is_ps, sizeof(st.is_ps))) { ipf_state_del(softc, sp, ISL_REMOVE); RWLOCK_EXIT(&softc->ipf_state); return 0; } RWLOCK_EXIT(&softc->ipf_state); IPFERROR(100001); return ESRCH; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_ioctl */ /* Returns: int - 0 == success, != 0 == failure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* data(I) - pointer to ioctl data */ /* cmd(I) - ioctl command integer */ /* mode(I) - file mode bits used with open */ /* uid(I) - uid of process making the ioctl call */ /* ctx(I) - pointer specific to context of the call */ /* */ /* Processes an ioctl call made to operate on the IP Filter state device. */ /* ------------------------------------------------------------------------ */ int ipf_state_ioctl(ipf_main_softc_t *softc, void *data, ioctlcmd_t cmd, int mode, int uid, void *ctx) { ipf_state_softc_t *softs = softc->ipf_state_soft; int arg, ret, error = 0; SPL_INT(s); switch (cmd) { /* * Delete an entry from the state table. */ case SIOCDELST : error = ipf_state_remove(softc, data); break; /* * Flush the state table */ case SIOCIPFFL : error = BCOPYIN(data, &arg, sizeof(arg)); if (error != 0) { IPFERROR(100002); error = EFAULT; } else { WRITE_ENTER(&softc->ipf_state); ret = ipf_state_flush(softc, arg, 4); RWLOCK_EXIT(&softc->ipf_state); error = BCOPYOUT(&ret, data, sizeof(ret)); if (error != 0) { IPFERROR(100003); error = EFAULT; } } break; #ifdef USE_INET6 case SIOCIPFL6 : error = BCOPYIN(data, &arg, sizeof(arg)); if (error != 0) { IPFERROR(100004); error = EFAULT; } else { WRITE_ENTER(&softc->ipf_state); ret = ipf_state_flush(softc, arg, 6); RWLOCK_EXIT(&softc->ipf_state); error = BCOPYOUT(&ret, data, sizeof(ret)); if (error != 0) { IPFERROR(100005); error = EFAULT; } } break; #endif case SIOCMATCHFLUSH : WRITE_ENTER(&softc->ipf_state); error = ipf_state_matchflush(softc, data); RWLOCK_EXIT(&softc->ipf_state); break; #ifdef IPFILTER_LOG /* * Flush the state log. */ case SIOCIPFFB : if (!(mode & FWRITE)) { IPFERROR(100008); error = EPERM; } else { int tmp; tmp = ipf_log_clear(softc, IPL_LOGSTATE); error = BCOPYOUT(&tmp, data, sizeof(tmp)); if (error != 0) { IPFERROR(100009); error = EFAULT; } } break; /* * Turn logging of state information on/off. */ case SIOCSETLG : if (!(mode & FWRITE)) { IPFERROR(100010); error = EPERM; } else { error = BCOPYIN(data, &softs->ipf_state_logging, sizeof(softs->ipf_state_logging)); if (error != 0) { IPFERROR(100011); error = EFAULT; } } break; /* * Return the current state of logging. */ case SIOCGETLG : error = BCOPYOUT(&softs->ipf_state_logging, data, sizeof(softs->ipf_state_logging)); if (error != 0) { IPFERROR(100012); error = EFAULT; } break; /* * Return the number of bytes currently waiting to be read. */ case FIONREAD : arg = ipf_log_bytesused(softc, IPL_LOGSTATE); error = BCOPYOUT(&arg, data, sizeof(arg)); if (error != 0) { IPFERROR(100013); error = EFAULT; } break; #endif /* * Get the current state statistics. */ case SIOCGETFS : error = ipf_outobj(softc, data, ipf_state_stats(softc), IPFOBJ_STATESTAT); break; /* * Lock/Unlock the state table. (Locking prevents any changes, which * means no packets match). */ case SIOCSTLCK : if (!(mode & FWRITE)) { IPFERROR(100014); error = EPERM; } else { error = ipf_lock(data, &softs->ipf_state_lock); } break; /* * Add an entry to the current state table. */ case SIOCSTPUT : if (!softs->ipf_state_lock || !(mode &FWRITE)) { IPFERROR(100015); error = EACCES; break; } error = ipf_state_putent(softc, softs, data); break; /* * Get a state table entry. */ case SIOCSTGET : if (!softs->ipf_state_lock) { IPFERROR(100016); error = EACCES; break; } error = ipf_state_getent(softc, softs, data); break; /* * Return a copy of the hash table bucket lengths */ case SIOCSTAT1 : error = BCOPYOUT(softs->ipf_state_stats.iss_bucketlen, data, softs->ipf_state_size * sizeof(u_int)); if (error != 0) { IPFERROR(100017); error = EFAULT; } break; case SIOCGENITER : { ipftoken_t *token; ipfgeniter_t iter; ipfobj_t obj; error = ipf_inobj(softc, data, &obj, &iter, IPFOBJ_GENITER); if (error != 0) break; SPL_SCHED(s); token = ipf_token_find(softc, IPFGENITER_STATE, uid, ctx); if (token != NULL) { error = ipf_state_iter(softc, token, &iter, &obj); WRITE_ENTER(&softc->ipf_tokens); ipf_token_deref(softc, token); RWLOCK_EXIT(&softc->ipf_tokens); } else { IPFERROR(100018); error = ESRCH; } SPL_X(s); break; } case SIOCGTABL : error = ipf_state_gettable(softc, softs, data); break; case SIOCIPFDELTOK : error = BCOPYIN(data, &arg, sizeof(arg)); if (error != 0) { IPFERROR(100019); error = EFAULT; } else { SPL_SCHED(s); error = ipf_token_del(softc, arg, uid, ctx); SPL_X(s); } break; case SIOCGTQTAB : error = ipf_outobj(softc, data, softs->ipf_state_tcptq, IPFOBJ_STATETQTAB); break; default : IPFERROR(100020); error = EINVAL; break; } return error; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_getent */ /* Returns: int - 0 == success, != 0 == failure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* softs(I) - pointer to state context structure */ /* 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. */ /* ------------------------------------------------------------------------ */ static int ipf_state_getent(ipf_main_softc_t *softc, ipf_state_softc_t *softs, void *data) { ipstate_t *is, *isn; ipstate_save_t ips; int error; error = ipf_inobj(softc, data, NULL, &ips, IPFOBJ_STATESAVE); if (error) return EFAULT; READ_ENTER(&softc->ipf_state); isn = ips.ips_next; if (isn == NULL) { isn = softs->ipf_state_list; if (isn == NULL) { if (ips.ips_next == NULL) { RWLOCK_EXIT(&softc->ipf_state); IPFERROR(100021); 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 = softs->ipf_state_list; is; is = is->is_next) if (is == isn) break; if (!is) { RWLOCK_EXIT(&softc->ipf_state); IPFERROR(100022); 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)); RWLOCK_EXIT(&softc->ipf_state); error = ipf_outobj(softc, data, &ips, IPFOBJ_STATESAVE); return error; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_putent */ /* Returns: int - 0 == success, != 0 == failure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* softs(I) - pointer to state context structure */ /* 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 ipf_state_putent(ipf_main_softc_t *softc, ipf_state_softc_t *softs, void *data) { ipstate_t *is, *isn; ipstate_save_t ips; int error, i; frentry_t *fr; char *name; error = ipf_inobj(softc, data, NULL, &ips, IPFOBJ_STATESAVE); if (error != 0) return error; KMALLOC(isn, ipstate_t *); if (isn == NULL) { IPFERROR(100023); 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) { int inserr; READ_ENTER(&softc->ipf_state); inserr = ipf_state_insert(softc, isn, 0); MUTEX_EXIT(&isn->is_lock); RWLOCK_EXIT(&softc->ipf_state); return inserr; } if (isn->is_flags & SI_NEWFR) { KMALLOC(fr, frentry_t *); if (fr == NULL) { KFREE(isn); IPFERROR(100024); return ENOMEM; } bcopy((char *)&ips.ips_fr, (char *)fr, sizeof(*fr)); 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++) { if (fr->fr_ifnames[i] == -1) { fr->fr_ifas[i] = NULL; continue; } name = fr->fr_names + fr->fr_ifnames[i]; fr->fr_ifas[i] = ipf_resolvenic(softc, name, fr->fr_family); } for (i = 0; i < 4; i++) { name = isn->is_ifname[i]; isn->is_ifp[i] = ipf_resolvenic(softc, name, isn->is_v); } fr->fr_ref = 0; fr->fr_dsize = 0; fr->fr_data = NULL; fr->fr_type = FR_T_NONE; (void) ipf_resolvedest(softc, fr->fr_names, &fr->fr_tifs[0], fr->fr_family); (void) ipf_resolvedest(softc, fr->fr_names, &fr->fr_tifs[1], fr->fr_family); (void) ipf_resolvedest(softc, fr->fr_names, &fr->fr_dif, fr->fr_family); /* * send a copy back to userland of what we ended up * to allow for verification. */ error = ipf_outobj(softc, data, &ips, IPFOBJ_STATESAVE); if (error != 0) { KFREE(isn); MUTEX_DESTROY(&fr->fr_lock); KFREE(fr); IPFERROR(100025); return EFAULT; } READ_ENTER(&softc->ipf_state); error = ipf_state_insert(softc, isn, 0); MUTEX_EXIT(&isn->is_lock); RWLOCK_EXIT(&softc->ipf_state); } else { READ_ENTER(&softc->ipf_state); for (is = softs->ipf_state_list; is; is = is->is_next) if (is->is_rule == fr) { error = ipf_state_insert(softc, isn, 0); MUTEX_EXIT(&isn->is_lock); break; } if (is == NULL) { KFREE(isn); isn = NULL; } RWLOCK_EXIT(&softc->ipf_state); if (isn == NULL) { IPFERROR(100033); error = ESRCH; } } return error; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_insert */ /* Returns: int - 0 == success, -1 == failure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* Parameters: is(I) - pointer to state structure */ /* rev(I) - flag indicating 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. */ /* */ /* This function can fail if the filter rule has had a population policy of */ /* IP addresses used with stateful filtering assigned to it. */ /* */ /* Locking: it is assumed that some kind of lock on ipf_state is held. */ /* Exits with is_lock initialised and held - *EVEN IF ERROR*. */ /* ------------------------------------------------------------------------ */ int ipf_state_insert(ipf_main_softc_t *softc, ipstate_t *is, int rev) { ipf_state_softc_t *softs = softc->ipf_state_soft; frentry_t *fr; u_int hv; int i; /* * 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] = ipf_resolvenic(softc, is->is_ifname[i], is->is_v); } /* * If we could trust is_hv, then the modulus would not be needed, * but when running with IPFILTER_SYNC, this stops bad values. */ hv = is->is_hv % softs->ipf_state_size; /* TRACE is, hv */ 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_INIT(&is->is_lock, "ipf state entry"); MUTEX_ENTER(&is->is_lock); MUTEX_ENTER(&softs->ipf_stinsert); fr = is->is_rule; if (fr != NULL) { if ((fr->fr_srctrack.ht_max_nodes != 0) && (ipf_ht_node_add(softc, &fr->fr_srctrack, is->is_family, &is->is_src) == -1)) { SBUMPD(ipf_state_stats, iss_max_track); MUTEX_EXIT(&softs->ipf_stinsert); return -1; } MUTEX_ENTER(&fr->fr_lock); fr->fr_ref++; MUTEX_EXIT(&fr->fr_lock); fr->fr_statecnt++; } if (is->is_flags & (SI_WILDP|SI_WILDA)) { DT(iss_wild_plus_one); SINCL(ipf_state_stats.iss_wild); } SBUMP(ipf_state_stats.iss_proto[is->is_p]); SBUMP(ipf_state_stats.iss_active_proto[is->is_p]); /* * add into list table. */ if (softs->ipf_state_list != NULL) softs->ipf_state_list->is_pnext = &is->is_next; is->is_pnext = &softs->ipf_state_list; is->is_next = softs->ipf_state_list; softs->ipf_state_list = is; if (softs->ipf_state_table[hv] != NULL) softs->ipf_state_table[hv]->is_phnext = &is->is_hnext; else softs->ipf_state_stats.iss_inuse++; is->is_phnext = softs->ipf_state_table + hv; is->is_hnext = softs->ipf_state_table[hv]; softs->ipf_state_table[hv] = is; softs->ipf_state_stats.iss_bucketlen[hv]++; softs->ipf_state_stats.iss_active++; MUTEX_EXIT(&softs->ipf_stinsert); ipf_state_setqueue(softc, is, rev); return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_matchipv4addrs */ /* Returns: int - 2 addresses match (strong match), 1 reverse match, */ /* 0 no match */ /* Parameters: is1, is2 pointers to states we are checking */ /* */ /* Function matches IPv4 addresses it returns strong match for ICMP proto */ /* even there is only reverse match */ /* ------------------------------------------------------------------------ */ static int ipf_state_matchipv4addrs(ipstate_t *is1, ipstate_t *is2) { int rv; if (is1->is_saddr == is2->is_saddr && is1->is_daddr == is2->is_daddr) rv = 2; else if (is1->is_saddr == is2->is_daddr && is1->is_daddr == is2->is_saddr) { /* force strong match for ICMP protocol */ rv = (is1->is_p == IPPROTO_ICMP) ? 2 : 1; } else rv = 0; return (rv); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_matchipv6addrs */ /* Returns: int - 2 addresses match (strong match), 1 reverse match, */ /* 0 no match */ /* Parameters: is1, is2 pointers to states we are checking */ /* */ /* Function matches IPv6 addresses it returns strong match for ICMP proto */ /* even there is only reverse match */ /* ------------------------------------------------------------------------ */ static int ipf_state_matchipv6addrs(ipstate_t *is1, ipstate_t *is2) { int rv; if (IP6_EQ(&is1->is_src, &is2->is_src) && IP6_EQ(&is1->is_dst, &is2->is_dst)) rv = 2; else if (IP6_EQ(&is1->is_src, &is2->is_dst) && IP6_EQ(&is1->is_dst, &is2->is_src)) { /* force strong match for ICMPv6 protocol */ rv = (is1->is_p == IPPROTO_ICMPV6) ? 2 : 1; } else rv = 0; return (rv); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_matchaddresses */ /* Returns: int - 2 addresses match, 1 reverse match, zero no match */ /* Parameters: is1, is2 pointers to states we are checking */ /* */ /* function retruns true if two pairs of addresses belong to single */ /* connection. suppose there are two endpoints: */ /* endpoint1 1.1.1.1 */ /* endpoint2 1.1.1.2 */ /* */ /* the state is established by packet flying from .1 to .2 so we see: */ /* is1->src = 1.1.1.1 */ /* is1->dst = 1.1.1.2 */ /* now endpoint 1.1.1.2 sends answer */ /* retreives is1 record created by first packat and compares it with is2 */ /* temporal record, is2 is initialized as follows: */ /* is2->src = 1.1.1.2 */ /* is2->dst = 1.1.1.1 */ /* in this case 1 will be returned */ /* */ /* the ipf_matchaddresses() assumes those two records to be same. of course */ /* the ipf_matchaddresses() also assume records are same in case you pass */ /* identical arguments (i.e. ipf_matchaddress(is1, is1) would return 2 */ /* ------------------------------------------------------------------------ */ static int ipf_state_matchaddresses(ipstate_t *is1, ipstate_t *is2) { int rv; if (is1->is_v == 4) { rv = ipf_state_matchipv4addrs(is1, is2); } else { rv = ipf_state_matchipv6addrs(is1, is2); } return (rv); } /* ------------------------------------------------------------------------ */ /* Function: ipf_matchports */ /* Returns: int - 2 match, 1 rverse match, 0 no match */ /* Parameters: ppairs1, ppairs - src, dst ports we want to match */ /* */ /* performs the same match for isps members as for addresses */ /* ------------------------------------------------------------------------ */ static int ipf_state_matchports(udpinfo_t *ppairs1, udpinfo_t *ppairs2) { int rv; if (ppairs1->us_sport == ppairs2->us_sport && ppairs1->us_dport == ppairs2->us_dport) rv = 2; else if (ppairs1->us_sport == ppairs2->us_dport && ppairs1->us_dport == ppairs2->us_sport) rv = 1; else rv = 0; return (rv); } /* ------------------------------------------------------------------------ */ /* Function: ipf_matchisps */ /* Returns: int - nonzero if isps members match, 0 nomatch */ /* Parameters: is1, is2 - states we want to match */ /* */ /* performs the same match for isps members as for addresses */ /* ------------------------------------------------------------------------ */ static int ipf_state_matchisps(ipstate_t *is1, ipstate_t *is2) { int rv; if (is1->is_p == is2->is_p) { switch (is1->is_p) { case IPPROTO_TCP : case IPPROTO_UDP : case IPPROTO_GRE : /* greinfo_t can be also interprted as port pair */ rv = ipf_state_matchports(&is1->is_ps.is_us, &is2->is_ps.is_us); break; case IPPROTO_ICMP : case IPPROTO_ICMPV6 : /* force strong match for ICMP datagram. */ if (bcmp(&is1->is_ps, &is2->is_ps, sizeof(icmpinfo_t)) == 0) { rv = 2; } else { rv = 0; } break; default: rv = 0; } } else { rv = 0; } return (rv); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_match */ /* Returns: int - nonzero match, zero no match */ /* Parameters: is1, is2 - states we want to match */ /* */ /* ------------------------------------------------------------------------ */ static int ipf_state_match(ipstate_t *is1, ipstate_t *is2) { int rv; int amatch; int pomatch; if (bcmp(&is1->is_pass, &is2->is_pass, offsetof(struct ipstate, is_authmsk) - offsetof(struct ipstate, is_pass)) == 0) { pomatch = ipf_state_matchisps(is1, is2); amatch = ipf_state_matchaddresses(is1, is2); rv = (amatch != 0) && (amatch == pomatch); } else { rv = 0; } return (rv); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_add */ /* Returns: ipstate_t - 0 = success */ /* Parameters: softc(I) - pointer to soft context main structure */ /* 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. */ /* ------------------------------------------------------------------------ */ int ipf_state_add(ipf_main_softc_t *softc, fr_info_t *fin, ipstate_t **stsave, u_int flags) { ipf_state_softc_t *softs = softc->ipf_state_soft; ipstate_t *is, ips; struct icmp *ic; u_int pass, hv; frentry_t *fr; tcphdr_t *tcp; frdest_t *fdp; int out; /* * If a packet that was created locally is trying to go out but we * do not match here because of this lock, it is likely that * the policy will block it and return network unreachable back up * the stack. To mitigate this error, EAGAIN is returned instead, * telling the IP stack to try sending this packet again later. */ if (softs->ipf_state_lock) { SBUMPD(ipf_state_stats, iss_add_locked); fin->fin_error = EAGAIN; return -1; } if (fin->fin_flx & (FI_SHORT|FI_STATE|FI_FRAGBODY|FI_BAD)) { SBUMPD(ipf_state_stats, iss_add_bad); return -1; } if ((fin->fin_flx & FI_OOW) && !(fin->fin_tcpf & TH_SYN)) { SBUMPD(ipf_state_stats, iss_add_oow); return -1; } if ((softs->ipf_state_stats.iss_active * 100 / softs->ipf_state_max) > softs->ipf_state_wm_high) { softs->ipf_state_doflush = 1; } /* * 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 ((softs->ipf_state_stats.iss_active >= softs->ipf_state_max) && (fr->fr_statemax == 0)) { SBUMPD(ipf_state_stats, iss_max); return 1; } if ((fr->fr_statemax != 0) && (fr->fr_statecnt >= fr->fr_statemax)) { SBUMPD(ipf_state_stats, iss_max_ref); return 2; } } is = &ips; if (fr == NULL) { pass = softc->ipf_flags; is->is_tag = FR_NOLOGTAG; } else { pass = fr->fr_flags; } ic = NULL; tcp = NULL; out = fin->fin_out; bzero((char *)is, sizeof(*is)); is->is_die = 1 + softc->ipf_ticks; /* * We want to check everything that is a property of this packet, * but we don't (automatically) care about its fragment status as * this may change. */ is->is_pass = pass; is->is_v = fin->fin_v; is->is_sec = fin->fin_secmsk; is->is_secmsk = 0xffff; is->is_auth = fin->fin_auth; is->is_authmsk = 0xffff; is->is_family = fin->fin_family; is->is_opt[0] = fin->fin_optmsk; is->is_optmsk[0] = 0xffffffff; if (is->is_v == 6) { is->is_opt[0] &= ~0x8; is->is_optmsk[0] &= ~0x8; } /* * 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))) { flags |= SI_W_DADDR; hv -= is->is_daddr; } switch (is->is_p) { #ifdef USE_INET6 case IPPROTO_ICMPV6 : ic = fin->fin_dp; switch (ic->icmp_type) { case ICMP6_ECHO_REQUEST : hv += (is->is_icmp.ici_id = ic->icmp_id); /*FALLTHROUGH*/ 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 : SBUMPD(ipf_state_stats, iss_icmp6_notquery); return -2; } 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 : SBUMPD(ipf_state_stats, iss_icmp_notquery); return -3; } break; #if 0 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; #endif case IPPROTO_TCP : tcp = fin->fin_dp; if (tcp->th_flags & TH_RST) { SBUMPD(ipf_state_stats, iss_tcp_rstadd); return -4; } /* TRACE is, flags, hv */ /* * 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; } /* TRACE is, flags, hv */ /* * 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 (ipf_tcpoptions(softs, fin, tcp, &is->is_tcp.ts_data[0]) == -1) fin->fin_flx |= FI_BAD; } if ((fin->fin_out != 0) && (pass & FR_NEWISN) != 0) { ipf_checknewisn(fin, is); ipf_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. */ 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; } break; default : break; } hv = DOUBLE_HASH(hv); is->is_hv = hv; /* * Look for identical state. */ for (is = softs->ipf_state_table[hv % softs->ipf_state_size]; is != NULL; is = is->is_hnext) { if (ipf_state_match(&ips, is) == 1) break; } if (is != NULL) { SBUMPD(ipf_state_stats, iss_add_dup); return 3; } if (softs->ipf_state_stats.iss_bucketlen[hv] >= softs->ipf_state_maxbucket) { SBUMPD(ipf_state_stats, iss_bucket_full); return 4; } /* * No existing state; create new */ KMALLOC(is, ipstate_t *); if (is == NULL) { SBUMPD(ipf_state_stats, iss_nomem); return 5; } bcopy((char *)&ips, (char *)is, sizeof(*is)); is->is_flags = flags & IS_INHERITED; is->is_rulen = fin->fin_rule; is->is_rule = fr; /* * Do not do the modulus here, it is done in ipf_state_insert(). */ if (fr != NULL) { ipftq_t *tq; (void) strncpy(is->is_group, FR_NAME(fr, fr_group), FR_GROUPLEN); if (fr->fr_age[0] != 0) { tq = ipf_addtimeoutqueue(softc, &softs->ipf_state_usertq, fr->fr_age[0]); is->is_tqehead[0] = tq; is->is_sti.tqe_flags |= TQE_RULEBASED; } if (fr->fr_age[1] != 0) { tq = ipf_addtimeoutqueue(softc, &softs->ipf_state_usertq, fr->fr_age[1]); is->is_tqehead[1] = tq; is->is_sti.tqe_flags |= TQE_RULEBASED; } is->is_tag = fr->fr_logtag; } /* * It may seem strange to set is_ref to 2, but if stsave is not NULL * then a copy of the pointer is being stored somewhere else and in * the end, it will expect to be able to do something with it. */ is->is_me = stsave; if (stsave != NULL) { *stsave = is; is->is_ref = 2; } else { is->is_ref = 1; } 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; fin->fin_pktnum = 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_STLOOSE) is->is_flags |= IS_LOOSE; if (pass & FR_STSTRICT) is->is_flags |= IS_STRICT; if (pass & FR_STATESYNC) is->is_flags |= IS_STATESYNC; if (pass & FR_LOGFIRST) is->is_pass &= ~(FR_LOGFIRST|FR_LOG); READ_ENTER(&softc->ipf_state); if (ipf_state_insert(softc, is, fin->fin_rev) == -1) { RWLOCK_EXIT(&softc->ipf_state); /* * This is a bit more manual than it should be but * ipf_state_del cannot be called. */ MUTEX_EXIT(&is->is_lock); MUTEX_DESTROY(&is->is_lock); if (is->is_tqehead[0] != NULL) { if (ipf_deletetimeoutqueue(is->is_tqehead[0]) == 0) ipf_freetimeoutqueue(softc, is->is_tqehead[0]); is->is_tqehead[0] = NULL; } if (is->is_tqehead[1] != NULL) { if (ipf_deletetimeoutqueue(is->is_tqehead[1]) == 0) ipf_freetimeoutqueue(softc, is->is_tqehead[1]); is->is_tqehead[1] = NULL; } KFREE(is); return -1; } /* * Filling in the interface name is after the insert so that an * event (such as add/delete) of an interface that is referenced * by this rule will see this state entry. */ if (fr != NULL) { /* * 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] != -1 && fr->fr_names[fr->fr_ifnames[out << 1] + 0] == '-' && fr->fr_names[fr->fr_ifnames[out << 1] + 1] == '\0')) { is->is_ifp[out << 1] = fr->fr_ifas[0]; strncpy(is->is_ifname[out << 1], fr->fr_names + fr->fr_ifnames[0], sizeof(fr->fr_ifnames[0])); } else { is->is_ifp[out << 1] = fin->fin_ifp; COPYIFNAME(fin->fin_v, fin->fin_ifp, is->is_ifname[out << 1]); } is->is_ifp[(out << 1) + 1] = fr->fr_ifas[1]; if (fr->fr_ifnames[1] != -1) { strncpy(is->is_ifname[(out << 1) + 1], fr->fr_names + fr->fr_ifnames[1], sizeof(fr->fr_ifnames[1])); } is->is_ifp[(1 - out) << 1] = fr->fr_ifas[2]; if (fr->fr_ifnames[2] != -1) { strncpy(is->is_ifname[((1 - out) << 1)], fr->fr_names + fr->fr_ifnames[2], sizeof(fr->fr_ifnames[2])); } is->is_ifp[((1 - out) << 1) + 1] = fr->fr_ifas[3]; if (fr->fr_ifnames[3] != -1) { strncpy(is->is_ifname[((1 - out) << 1) + 1], fr->fr_names + fr->fr_ifnames[3], sizeof(fr->fr_ifnames[3])); } } else { if (fin->fin_ifp != NULL) { is->is_ifp[out << 1] = fin->fin_ifp; COPYIFNAME(fin->fin_v, fin->fin_ifp, is->is_ifname[out << 1]); } } 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) ipf_tcp_age(&is->is_sti, fin, softs->ipf_state_tcptq, is->is_flags, 2); } MUTEX_EXIT(&is->is_lock); if ((is->is_flags & IS_STATESYNC) && ((is->is_flags & SI_CLONE) == 0)) is->is_sync = ipf_sync_new(softc, SMC_STATE, fin, is); if (softs->ipf_state_logging) ipf_state_log(softc, is, ISL_NEW); RWLOCK_EXIT(&softc->ipf_state); fin->fin_flx |= FI_STATE; if (fin->fin_flx & FI_FRAG) (void) ipf_frag_new(softc, fin, pass); fdp = &fr->fr_tifs[0]; if (fdp->fd_type == FRD_DSTLIST) { ipf_dstlist_select_node(fin, fdp->fd_ptr, NULL, &is->is_tifs[0]); } else { bcopy(fdp, &is->is_tifs[0], sizeof(*fdp)); } fdp = &fr->fr_tifs[1]; if (fdp->fd_type == FRD_DSTLIST) { ipf_dstlist_select_node(fin, fdp->fd_ptr, NULL, &is->is_tifs[1]); } else { bcopy(fdp, &is->is_tifs[1], sizeof(*fdp)); } fin->fin_tif = &is->is_tifs[fin->fin_rev]; fdp = &fr->fr_dif; if (fdp->fd_type == FRD_DSTLIST) { ipf_dstlist_select_node(fin, fdp->fd_ptr, NULL, &is->is_dif); } else { bcopy(fdp, &is->is_dif, sizeof(*fdp)); } fin->fin_dif = &is->is_dif; return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_tcpoptions */ /* Returns: int - 1 == packet matches state entry, 0 == it does not, */ /* -1 == packet has bad TCP options data */ /* Parameters: softs(I) - pointer to state context structure */ /* 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 ipf_tcpoptions(ipf_state_softc_t *softs, 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) { SBUMPD(ipf_state_stats, iss_tcp_toosmall); 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 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; } if (retval == -1) { SBUMPD(ipf_state_stats, iss_tcp_badopt); } return retval; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_tcp */ /* Returns: int - 1 == packet matches state entry, 0 == it does not */ /* Parameters: softc(I) - pointer to soft context main structure */ /* softs(I) - pointer to state context structure */ /* 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 ipf_state_tcp(ipf_main_softc_t *softc, ipf_state_softc_t *softs, fr_info_t *fin, tcphdr_t *tcp, ipstate_t *is) { tcpdata_t *fdata, *tdata; int source, ret, flags; 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; ipf_movequeue(softc->ipf_ticks, &is->is_sti, is->is_sti.tqe_ifq, &softs->ipf_state_deletetq); MUTEX_EXIT(&is->is_lock); DT1(iss_tcp_closing, ipstate_t *, is); SBUMP(ipf_state_stats.iss_tcp_closing); return 0; } } if (is->is_flags & IS_LOOSE) ret = 1; else ret = ipf_state_tcpinwindow(fin, fdata, tdata, tcp, is->is_flags); if (ret > 0) { /* * Nearing end of connection, start timeout. */ ret = ipf_tcp_age(&is->is_sti, fin, softs->ipf_state_tcptq, is->is_flags, ret); if (ret == 0) { MUTEX_EXIT(&is->is_lock); DT2(iss_tcp_fsm, fr_info_t *, fin, ipstate_t *, is); SBUMP(ipf_state_stats.iss_tcp_fsm); return 0; } if (softs->ipf_state_logging > 4) ipf_state_log(softc, is, ISL_STATECHANGE); /* * 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 (ipf_tcpoptions(softs, fin, tcp, fdata) == -1) fin->fin_flx |= FI_BAD; } if ((fin->fin_out != 0) && (is->is_pass & FR_NEWISN)) ipf_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 (ipf_tcpoptions(softs, fin, tcp, fdata) == -1) fin->fin_flx |= FI_BAD; } if ((fin->fin_out != 0) && (is->is_pass & FR_NEWISN)) ipf_checknewisn(fin, is); } ret = 1; } else { DT2(iss_tcp_oow, fr_info_t *, fin, ipstate_t *, is); SBUMP(ipf_state_stats.iss_tcp_oow); ret = 0; } MUTEX_EXIT(&is->is_lock); return ret; } /* ------------------------------------------------------------------------ */ /* Function: ipf_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 ipf_checknewisn(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 = ipf_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: ipf_state_tcpinwindow */ /* Returns: int - 1 == packet inside TCP "window", 0 == not inside. */ /* Parameters: fin(I) - pointer to packet information */ /* fdata(I) - pointer to tcp state informatio (forward) */ /* tdata(I) - pointer to tcp state informatio (reverse) */ /* tcp(I) - pointer to TCP packet header */ /* */ /* Given a packet has matched addresses and ports, check to see if it is */ /* within the TCP data window. In a show of generosity, allow packets that */ /* are within the window space behind the current sequence # as well. */ /* ------------------------------------------------------------------------ */ static int ipf_state_tcpinwindow(fr_info_t *fin, tcpdata_t *fdata, tcpdata_t *tdata, tcphdr_t *tcp, int flags) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_state_softc_t *softs = softc->ipf_state_soft; 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 ((flags & IS_STRICT) != 0) { if (seq != fdata->td_end) { DT2(iss_tcp_struct, tcpdata_t *, fdata, int, seq); SBUMP(ipf_state_stats.iss_tcp_strict); fin->fin_flx |= FI_OOW; return 0; } } #define SEQ_GE(a,b) ((int)((a) - (b)) >= 0) #define SEQ_GT(a,b) ((int)((a) - (b)) > 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)) { DT2(iss_sinsack, tcpdata_t *, fdata, int, seq); SBUMP(ipf_state_stats.iss_winsack); 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)) { #if 0 int i; i = (fin->fin_rev << 1) + fin->fin_out; 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; } SBUMP(ipf_state_stats.iss_oow); fin->fin_flx |= FI_OOW; return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_clone */ /* 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 * ipf_state_clone(fr_info_t *fin, tcphdr_t *tcp, ipstate_t *is) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_state_softc_t *softs = softc->ipf_state_soft; ipstate_t *clone; u_32_t send; if (softs->ipf_state_stats.iss_active == softs->ipf_state_max) { SBUMPD(ipf_state_stats, iss_max); softs->ipf_state_doflush = 1; return NULL; } KMALLOC(clone, ipstate_t *); if (clone == NULL) { SBUMPD(ipf_state_stats, iss_clone_nomem); return NULL; } bcopy((char *)is, (char *)clone, sizeof(*clone)); MUTEX_NUKE(&clone->is_lock); /* * It has not yet been placed on any timeout queue, so make sure * all of that data is zero'd out. */ clone->is_sti.tqe_pnext = NULL; clone->is_sti.tqe_next = NULL; clone->is_sti.tqe_ifq = NULL; clone->is_sti.tqe_parent = clone; clone->is_die = ONE_DAY + softc->ipf_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; if (ipf_state_insert(softc, clone, fin->fin_rev) == -1) { KFREE(clone); return NULL; } clone->is_ref = 1; if (clone->is_p == IPPROTO_TCP) { (void) ipf_tcp_age(&clone->is_sti, fin, softs->ipf_state_tcptq, clone->is_flags, 2); } MUTEX_EXIT(&clone->is_lock); if (is->is_flags & IS_STATESYNC) clone->is_sync = ipf_sync_new(softc, SMC_STATE, fin, clone); DT2(iss_clone, ipstate_t *, is, ipstate_t *, clone); SBUMP(ipf_state_stats.iss_cloned); return clone; } /* ------------------------------------------------------------------------ */ /* Function: ipf_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 */ /* cmask(I) - mask of FI_* bits to check */ /* */ /* 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 * ipf_matchsrcdst(fr_info_t *fin, ipstate_t *is, i6addr_t *src, i6addr_t *dst, tcphdr_t *tcp, u_32_t cmask) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_state_softc_t *softs = softc->ipf_state_soft; int ret = 0, rev, out, flags, flx = 0, idx; u_short sp, dp; u_32_t cflx; void *ifp; /* * If a connection is about to be deleted, no packets * are allowed to match it. */ if (is->is_sti.tqe_ifq == &softs->ipf_state_deletetq) return NULL; 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 = htons(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) { DT2(iss_lookup_badifp, fr_info_t *, fin, ipstate_t *, is); SBUMP(ipf_state_stats.iss_lookup_badifp); /* TRACE is, out, rev, idx */ 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) { SBUMP(ipf_state_stats.iss_lookup_badport); DT2(iss_lookup_badport, fr_info_t *, fin, ipstate_t *, is); /* TRACE rev, is, sp, dp, src, dst */ 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) { is->is_src = fi->fi_src; is->is_flags &= ~SI_W_SADDR; } else { if (!(fin->fin_flx & (FI_MULTICAST|FI_MBCAST))){ is->is_src = fi->fi_dst; is->is_flags &= ~SI_W_SADDR; } } } else if ((flags & SI_W_DADDR) != 0) { if (rev == 0) { if (!(fin->fin_flx & (FI_MULTICAST|FI_MBCAST))){ is->is_dst = fi->fi_dst; is->is_flags &= ~SI_W_DADDR; } } else { is->is_dst = fi->fi_src; is->is_flags &= ~SI_W_DADDR; } } if ((is->is_flags & (SI_WILDA|SI_WILDP)) == 0) { ATOMIC_DECL(softs->ipf_state_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)) { SBUMPD(ipf_state_stats, iss_miss_mask); return NULL; } if ((fin->fin_flx & FI_IGNORE) != 0) { fin->fin_rev = rev; return is; } /* * 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 ((flags & (SI_W_SPORT|SI_W_DPORT))) { if ((flags & SI_CLONE) != 0) { ipstate_t *clone; clone = ipf_state_clone(fin, tcp, is); if (clone == NULL) return NULL; is = clone; } else { ATOMIC_DECL(softs->ipf_state_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) && softs->ipf_state_logging) ipf_state_log(softc, is, ISL_CLONE); } ret = -1; if (is->is_flx[out][rev] == 0) { is->is_flx[out][rev] = flx; if (rev == 1 && is->is_optmsk[1] == 0) { is->is_opt[1] = fin->fin_optmsk; is->is_optmsk[1] = 0xffffffff; if (is->is_v == 6) { is->is_opt[1] &= ~0x8; is->is_optmsk[1] &= ~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(fin->fin_v, ifp, is->is_ifname[idx]); } fin->fin_rev = rev; return is; } /* ------------------------------------------------------------------------ */ /* Function: ipf_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 * ipf_checkicmpmatchingstate(fr_info_t *fin) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_state_softc_t *softs = softc->ipf_state_soft; ipstate_t *is, **isp; i6addr_t dst, src; struct icmp *ic; u_short savelen; icmphdr_t *icmp; fr_info_t ofin; tcphdr_t *tcp; int len; u_char pr; 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)) { SBUMPD(ipf_state_stats, iss_icmp_bad); return NULL; } ic = fin->fin_dp; 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)) { SBUMPDX(ipf_state_stats, iss_icmp_short, iss_icmp_short_1); return NULL; } /* * Sanity Checks. */ len = fin->fin_dlen - ICMPERR_ICMPHLEN; if ((len <= 0) || ((IP_HL(oip) << 2) > len)) { DT2(iss_icmp_len, fr_info_t *, fin, struct ip*, oip); SBUMPDX(ipf_state_stats, iss_icmp_short, iss_icmp_short_1); 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 ipf_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) { SBUMPDX(ipf_state_stats, iss_icmp_short, iss_icmp_short_2); return NULL; } # else if ((char *)oip + len > (char *)fin->fin_ip + m->m_len) { SBUMPDX(ipf_state_stats, iss_icmp_short, iss_icmp_short_3); 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. ipf_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_len. */ savelen = oip->ip_len; oip->ip_len = htons(len); 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) ipf_makefrip(IP_HL(oip) << 2, oip, &ofin); ofin.fin_ifp = fin->fin_ifp; ofin.fin_out = !fin->fin_out; 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; /* * Reset the short and bad flag here because in ipf_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 back as we don't know * if we have to forward the packet or process it again. */ oip->ip_len = savelen; 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) { DT1(iss_icmp_icmperr, fr_info_t *, &ofin); SBUMP(ipf_state_stats.iss_icmp_icmperr); return NULL; } /* * perform a lookup of the ICMP packet in the state table */ icmp = (icmphdr_t *)((char *)oip + (IP_HL(oip) << 2)); hv += icmp->icmp_id; hv = DOUBLE_HASH(hv); READ_ENTER(&softc->ipf_state); for (isp = &softs->ipf_state_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 = ipf_matchsrcdst(&ofin, is, &src, &dst, NULL, FI_ICMPCMP); if ((is != NULL) && !ipf_allowstateicmp(fin, is, &src)) return is; } RWLOCK_EXIT(&softc->ipf_state); SBUMPDX(ipf_state_stats, iss_icmp_miss, iss_icmp_miss_1); return NULL; case IPPROTO_TCP : case IPPROTO_UDP : break; default : SBUMPDX(ipf_state_stats, iss_icmp_miss, iss_icmp_miss_2); return NULL; } tcp = (tcphdr_t *)((char *)oip + (IP_HL(oip) << 2)); hv += tcp->th_dport;; hv += tcp->th_sport;; hv = DOUBLE_HASH(hv); READ_ENTER(&softc->ipf_state); for (isp = &softs->ipf_state_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 = ipf_matchsrcdst(&ofin, is, &src, &dst, tcp, FI_ICMPCMP))) { if (ipf_allowstateicmp(fin, is, &src) == 0) return is; } } RWLOCK_EXIT(&softc->ipf_state); SBUMPDX(ipf_state_stats, iss_icmp_miss, iss_icmp_miss_3); return NULL; } /* ------------------------------------------------------------------------ */ /* Function: ipf_allowstateicmp */ /* Returns: int - 1 = packet denied, 0 = packet allowed */ /* Parameters: fin(I) - pointer to packet information */ /* is(I) - pointer to state table entry */ /* src(I) - source address to check permission for */ /* */ /* For an ICMP packet that has so far matched a state table entry, check if */ /* there are any further refinements that might mean we want to block this */ /* packet. This code isn't specific to either IPv4 or IPv6. */ /* ------------------------------------------------------------------------ */ static int ipf_allowstateicmp(fr_info_t *fin, ipstate_t *is, i6addr_t *src) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_state_softc_t *softs = softc->ipf_state_soft; frentry_t *savefr; frentry_t *fr; u_32_t ipass; int backward; int oi; int i; fr = is->is_rule; if (fr != NULL && fr->fr_icmpgrp != NULL) { savefr = fin->fin_fr; fin->fin_fr = fr->fr_icmpgrp->fg_start; ipass = ipf_scanlist(fin, softc->ipf_pass); fin->fin_fr = savefr; if (FR_ISBLOCK(ipass)) { SBUMPD(ipf_state_stats, iss_icmp_headblock); return 1; } } /* * 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) + !fin->fin_out; if (is->is_pass & FR_NOICMPERR) { SBUMPD(ipf_state_stats, iss_icmp_banned); return 1; } if (is->is_icmppkts[i] > is->is_pkts[oi]) { SBUMPD(ipf_state_stats, iss_icmp_toomany); return 1; } DT2(iss_icmp_hits, fr_info_t *, fin, ipstate_t *, is); SBUMP(ipf_state_stats.iss_icmp_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 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_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 ipf_ipsmove(ipf_state_softc_t *softs, ipstate_t *is, u_int hv) { ipstate_t **isp; u_int hvm; hvm = is->is_hv; /* TRACE is, is_hv, hvm */ /* * 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 (softs->ipf_state_table[hvm] == NULL) softs->ipf_state_stats.iss_inuse--; softs->ipf_state_stats.iss_bucketlen[hvm]--; /* * ...and put the hash in the new one. */ hvm = DOUBLE_HASH(hv); is->is_hv = hvm; /* TRACE is, hv, is_hv, hvm */ isp = &softs->ipf_state_table[hvm]; if (*isp) (*isp)->is_phnext = &is->is_hnext; else softs->ipf_state_stats.iss_inuse++; softs->ipf_state_stats.iss_bucketlen[hvm]++; is->is_phnext = isp; is->is_hnext = *isp; *isp = is; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_lookup */ /* 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. */ /* ifqp(O) - pointer for storing tailq timeout */ /* */ /* Search the state table for a matching entry to the packet described by */ /* the contents of *fin. For certain protocols, when a match is found the */ /* timeout queue is also selected and stored in ifpq if it is non-NULL. */ /* */ /* 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 * ipf_state_lookup(fr_info_t *fin, tcphdr_t *tcp, ipftq_t **ifqp) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_state_softc_t *softs = softc->ipf_state_soft; 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; } } /* TRACE fin_saddr, fin_daddr, hv */ /* * 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(&softc->ipf_state); icmp6again: hvm = DOUBLE_HASH(hv); for (isp = &softs->ipf_state_table[hvm]; ((is = *isp) != NULL); ) { isp = &is->is_hnext; if ((is->is_p != pr) || (is->is_v != v)) continue; is = ipf_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); if (is != NULL && ipf_matchicmpqueryreply(v, &is->is_icmp, ic, fin->fin_rev)) { if (fin->fin_rev) ifq = &softs->ipf_state_icmpacktq; else ifq = &softs->ipf_state_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]; ipf_ipsmove(softs, is, hv); MUTEX_DOWNGRADE(&softc->ipf_state); } break; } RWLOCK_EXIT(&softc->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 ((softs->ipf_state_stats.iss_wild != 0) && ((fin->fin_flx & FI_NOWILD) == 0) && (v == 6) && (tryagain == 0)) { 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(&softc->ipf_state); goto icmp6again; } is = ipf_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(&softc->ipf_state); for (isp = &softs->ipf_state_table[hv]; ((is = *isp) != NULL); ) { isp = &is->is_hnext; if ((is->is_p != pr) || (is->is_v != v)) continue; is = ipf_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); if ((is != NULL) && (ic->icmp_id == is->is_icmp.ici_id) && ipf_matchicmpqueryreply(v, &is->is_icmp, ic, fin->fin_rev)) { if (fin->fin_rev) ifq = &softs->ipf_state_icmpacktq; else ifq = &softs->ipf_state_icmptq; break; } } if (is == NULL) { RWLOCK_EXIT(&softc->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(&softc->ipf_state); retry_tcpudp: hvm = DOUBLE_HASH(hv); /* TRACE hv, hvm */ for (isp = &softs->ipf_state_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 = ipf_matchsrcdst(fin, is, &src, &dst, tcp, FI_CMP); if (is != NULL) { if (pr == IPPROTO_TCP) { if (!ipf_state_tcp(softc, softs, 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; ipf_ipsmove(softs, is, hv); MUTEX_DOWNGRADE(&softc->ipf_state); } break; } RWLOCK_EXIT(&softc->ipf_state); if ((softs->ipf_state_stats.iss_wild != 0) && ((fin->fin_flx & FI_NOWILD) == 0)) { 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(&softc->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(&softc->ipf_state); for (isp = &softs->ipf_state_table[hvm]; ((is = *isp) != NULL); ) { isp = &is->is_hnext; if ((is->is_p != pr) || (is->is_v != v)) continue; is = ipf_matchsrcdst(fin, is, &src, &dst, NULL, FI_CMP); if (is != NULL) { ifq = &softs->ipf_state_iptq; break; } } if (is == NULL) { RWLOCK_EXIT(&softc->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; } else { SBUMP(ipf_state_stats.iss_lookup_miss); } return is; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_check */ /* Returns: frentry_t* - NULL == search failed, */ /* else pointer to rule for matching state */ /* Parameters: fin(I) - pointer to packet information */ /* passp(I) - pointer to filtering result flags */ /* */ /* Check if a packet is associated with an entry in the state table. */ /* ------------------------------------------------------------------------ */ frentry_t * ipf_state_check(fr_info_t *fin, u_32_t *passp) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_state_softc_t *softs = softc->ipf_state_soft; ipftqent_t *tqe; ipstate_t *is; frentry_t *fr; tcphdr_t *tcp; ipftq_t *ifq; u_int pass; int inout; if (softs->ipf_state_lock || (softs->ipf_state_list == NULL)) return NULL; if (fin->fin_flx & (FI_SHORT|FI_FRAGBODY|FI_BAD)) { SBUMPD(ipf_state_stats, iss_check_bad); return 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; ifq = NULL; /* * Search the hash table for matching packet header info. */ is = ipf_state_lookup(fin, tcp, &ifq); switch (fin->fin_p) { #ifdef USE_INET6 case IPPROTO_ICMPV6 : if (is != NULL) break; if (fin->fin_v == 6) { is = ipf_checkicmp6matchingstate(fin); } break; #endif case IPPROTO_ICMP : if (is != NULL) break; /* * No matching icmp state entry. Perhaps this is a * response to another state entry. */ is = ipf_checkicmpmatchingstate(fin); break; case IPPROTO_TCP : if (is == NULL) break; if (is->is_pass & FR_NEWISN) { if (fin->fin_out == 0) ipf_fixinisn(fin, is); else if (fin->fin_out == 1) ipf_fixoutisn(fin, is); } break; default : if (fin->fin_rev) ifq = &softs->ipf_state_udpacktq; else ifq = &softs->ipf_state_udptq; break; } if (is == NULL) { SBUMP(ipf_state_stats.iss_check_miss); return NULL; } fr = is->is_rule; if (fr != NULL) { if ((fin->fin_out == 0) && (fr->fr_nattag.ipt_num[0] != 0)) { if (fin->fin_nattag == NULL) { RWLOCK_EXIT(&softc->ipf_state); SBUMPD(ipf_state_stats, iss_check_notag); return NULL; } if (ipf_matchtag(&fr->fr_nattag, fin->fin_nattag)!=0) { RWLOCK_EXIT(&softc->ipf_state); SBUMPD(ipf_state_stats, iss_check_nattag); return NULL; } } (void) strncpy(fin->fin_group, FR_NAME(fr, fr_group), FR_GROUPLEN); fin->fin_icode = fr->fr_icode; } fin->fin_rule = is->is_rulen; fin->fin_fr = fr; /* * If this packet is a fragment and the rule says to track fragments, * then create a new fragment cache entry. */ if (fin->fin_flx & FI_FRAG && FR_ISPASS(is->is_pass) && is->is_pass & FR_KEEPFRAG) (void) ipf_frag_new(softc, fin, is->is_pass); /* * 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; if ((tqe->tqe_flags & TQE_RULEBASED) != 0) ifq = is->is_tqehead[fin->fin_rev]; MUTEX_ENTER(&is->is_lock); if (ifq != NULL) ipf_movequeue(softc->ipf_ticks, tqe, tqe->tqe_ifq, ifq); inout = (fin->fin_rev << 1) + fin->fin_out; is->is_pkts[inout]++; is->is_bytes[inout] += fin->fin_plen; fin->fin_pktnum = is->is_pkts[inout] + is->is_icmppkts[inout]; MUTEX_EXIT(&is->is_lock); pass = is->is_pass; if (is->is_flags & IS_STATESYNC) ipf_sync_update(softc, SMC_STATE, fin, is->is_sync); RWLOCK_EXIT(&softc->ipf_state); SBUMP(ipf_state_stats.iss_hits); fin->fin_dif = &is->is_dif; fin->fin_tif = &is->is_tifs[fin->fin_rev]; fin->fin_flx |= FI_STATE; if ((pass & FR_LOGFIRST) != 0) pass &= ~(FR_LOGFIRST|FR_LOG); *passp = pass; return fr; } /* ------------------------------------------------------------------------ */ /* Function: ipf_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 ipf_fixoutisn(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) && (fin->fin_cksum < FI_CK_L4PART)) { seq = ntohl(tcp->th_seq); seq += is->is_isninc[0]; tcp->th_seq = htonl(seq); ipf_fix_outcksum(0, &tcp->th_sum, is->is_sumd[0], 0); } } if ((is->is_flags & IS_ISNACK) != 0) { if ((rev == 1) && (fin->fin_cksum < FI_CK_L4PART)) { seq = ntohl(tcp->th_seq); seq += is->is_isninc[1]; tcp->th_seq = htonl(seq); ipf_fix_outcksum(0, &tcp->th_sum, is->is_sumd[1], 0); } } } /* ------------------------------------------------------------------------ */ /* Function: ipf_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 ipf_fixinisn(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) && (fin->fin_cksum < FI_CK_L4PART)) { ack = ntohl(tcp->th_ack); ack -= is->is_isninc[0]; tcp->th_ack = htonl(ack); ipf_fix_incksum(0, &tcp->th_sum, is->is_sumd[0], 0); } } if ((is->is_flags & IS_ISNACK) != 0) { if ((rev == 0) && (fin->fin_cksum < FI_CK_L4PART)) { ack = ntohl(tcp->th_ack); ack -= is->is_isninc[1]; tcp->th_ack = htonl(ack); ipf_fix_incksum(0, &tcp->th_sum, is->is_sumd[1], 0); } } } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_sync */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* 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 ipf_state_sync(ipf_main_softc_t *softc, void *ifp) { ipf_state_softc_t *softs = softc->ipf_state_soft; ipstate_t *is; int i; if (softc->ipf_running <= 0) return; WRITE_ENTER(&softc->ipf_state); if (softc->ipf_running <= 0) { RWLOCK_EXIT(&softc->ipf_state); return; } for (is = softs->ipf_state_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] = ipf_resolvenic(softc, is->is_ifname[i], is->is_v); } } RWLOCK_EXIT(&softc->ipf_state); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_del */ /* Returns: int - 0 = deleted, else refernce count on active struct */ /* Parameters: softc(I) - pointer to soft context main structure */ /* 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 ipf_state_del(ipf_main_softc_t *softc, ipstate_t *is, int why) { ipf_state_softc_t *softs = softc->ipf_state_soft; int orphan = 1; frentry_t *fr; /* * 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 (softs->ipf_state_table[is->is_hv] == NULL) softs->ipf_state_stats.iss_inuse--; softs->ipf_state_stats.iss_bucketlen[is->is_hv]--; is->is_phnext = NULL; is->is_hnext = NULL; orphan = 0; } /* * Because ipf_state_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(softs->ipf_state_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) ipf_deletequeueentry(&is->is_sti); /* * 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? ipf_state_flush() calls ipf_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_me != NULL) { *is->is_me = NULL; is->is_me = NULL; is->is_ref--; } is->is_ref--; if (is->is_ref > 0) { int refs; refs = is->is_ref; MUTEX_EXIT(&is->is_lock); if (!orphan) softs->ipf_state_stats.iss_orphan++; return refs; } fr = is->is_rule; is->is_rule = NULL; if (fr != NULL) { if (fr->fr_srctrack.ht_max_nodes != 0) { (void) ipf_ht_node_del(&fr->fr_srctrack, is->is_family, &is->is_src); } } ASSERT(is->is_ref == 0); MUTEX_EXIT(&is->is_lock); if (is->is_tqehead[0] != NULL) { if (ipf_deletetimeoutqueue(is->is_tqehead[0]) == 0) ipf_freetimeoutqueue(softc, is->is_tqehead[0]); } if (is->is_tqehead[1] != NULL) { if (ipf_deletetimeoutqueue(is->is_tqehead[1]) == 0) ipf_freetimeoutqueue(softc, is->is_tqehead[1]); } if (is->is_sync) ipf_sync_del_state(softc->ipf_sync_soft, is->is_sync); /* * 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 (softs->ipf_state_logging != 0 && why != 0) ipf_state_log(softc, is, why); if (is->is_p == IPPROTO_TCP) softs->ipf_state_stats.iss_fin++; else softs->ipf_state_stats.iss_expire++; if (orphan) softs->ipf_state_stats.iss_orphan--; if (fr != NULL) { fr->fr_statecnt--; (void) ipf_derefrule(softc, &fr); } softs->ipf_state_stats.iss_active_proto[is->is_p]--; MUTEX_DESTROY(&is->is_lock); KFREE(is); softs->ipf_state_stats.iss_active--; return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_expire */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* */ /* 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 ipf_state_expire(ipf_main_softc_t *softc) { ipf_state_softc_t *softs = softc->ipf_state_soft; ipftq_t *ifq, *ifqnext; ipftqent_t *tqe, *tqn; ipstate_t *is; SPL_INT(s); SPL_NET(s); WRITE_ENTER(&softc->ipf_state); for (ifq = softs->ipf_state_tcptq; ifq != NULL; ifq = ifq->ifq_next) for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { if (tqe->tqe_die > softc->ipf_ticks) break; tqn = tqe->tqe_next; is = tqe->tqe_parent; ipf_state_del(softc, is, ISL_EXPIRE); } for (ifq = softs->ipf_state_usertq; ifq != NULL; ifq = ifqnext) { ifqnext = ifq->ifq_next; for (tqn = ifq->ifq_head; ((tqe = tqn) != NULL); ) { if (tqe->tqe_die > softc->ipf_ticks) break; tqn = tqe->tqe_next; is = tqe->tqe_parent; ipf_state_del(softc, is, ISL_EXPIRE); } } for (ifq = softs->ipf_state_usertq; ifq != NULL; ifq = ifqnext) { ifqnext = ifq->ifq_next; if (((ifq->ifq_flags & IFQF_DELETE) != 0) && (ifq->ifq_ref == 0)) { ipf_freetimeoutqueue(softc, ifq); } } if (softs->ipf_state_doflush) { (void) ipf_state_flush(softc, 2, 0); softs->ipf_state_doflush = 0; softs->ipf_state_wm_last = softc->ipf_ticks; } RWLOCK_EXIT(&softc->ipf_state); SPL_X(s); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_flush */ /* Returns: int - 0 == success, -1 == failure */ /* Parameters: softc(I) - pointer to soft context main structure */ /* which(I) - which flush action to perform */ /* proto(I) - which protocol to flush (0 == ALL) */ /* 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. */ /* ------------------------------------------------------------------------ */ int ipf_state_flush(ipf_main_softc_t *softc, int which, int proto) { ipf_state_softc_t *softs = softc->ipf_state_soft; ipftqent_t *tqe, *tqn; ipstate_t *is, **isp; ipftq_t *ifq; int removed; SPL_INT(s); removed = 0; SPL_NET(s); switch (which) { case 0 : SBUMP(ipf_state_stats.iss_flush_all); /* * Style 0 flush removes everything... */ for (isp = &softs->ipf_state_list; ((is = *isp) != NULL); ) { if ((proto != 0) && (is->is_v != proto)) { isp = &is->is_next; continue; } if (ipf_state_del(softc, is, ISL_FLUSH) == 0) removed++; else isp = &is->is_next; } break; case 1 : SBUMP(ipf_state_stats.iss_flush_closing); /* * Since we're only interested in things that are closing, * we can start with the appropriate timeout queue. */ for (ifq = softs->ipf_state_tcptq + 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 (ipf_state_del(softc, is, ISL_FLUSH) == 0) removed++; } } /* * Also need to look through the user defined queues. */ for (ifq = softs->ipf_state_usertq; 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) continue; if ((is->is_state[0] > IPF_TCPS_ESTABLISHED) && (is->is_state[1] > IPF_TCPS_ESTABLISHED)) { if (ipf_state_del(softc, is, ISL_FLUSH) == 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 : SBUMP(ipf_state_stats.iss_flush_queue); tqn = softs->ipf_state_tcptq[which].ifq_head; while (tqn != NULL) { tqe = tqn; tqn = tqe->tqe_next; is = tqe->tqe_parent; if (ipf_state_del(softc, is, ISL_FLUSH) == 0) removed++; } break; default : if (which < 30) break; SBUMP(ipf_state_stats.iss_flush_state); /* * 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 = &softs->ipf_state_list; ((is = *isp) != NULL); ) { if ((proto == 0) || (is->is_v == proto)) { if (softc->ipf_ticks - is->is_touched > which) { if (ipf_state_del(softc, is, ISL_FLUSH) == 0) { removed++; continue; } } } isp = &is->is_next; } break; } if (which != 2) { SPL_X(s); return removed; } SBUMP(ipf_state_stats.iss_flush_timeout); /* * Asked to remove inactive entries because the table is full, try * again, 3 times, if first attempt failed with a different criteria * each time. The order tried in must be in decreasing age. * Another alternative is to implement random drop and drop N entries * at random until N have been freed up. */ if (softc->ipf_ticks - softs->ipf_state_wm_last > softs->ipf_state_wm_freq) { removed = ipf_queueflush(softc, ipf_state_flush_entry, softs->ipf_state_tcptq, softs->ipf_state_usertq, &softs->ipf_state_stats.iss_active, softs->ipf_state_size, softs->ipf_state_wm_low); softs->ipf_state_wm_last = softc->ipf_ticks; } SPL_X(s); return removed; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_flush_entry */ /* Returns: int - 0 = entry deleted, else not deleted */ /* Parameters: softc(I) - pointer to soft context main structure */ /* entry(I) - pointer to state structure to delete */ /* Write Locks: ipf_state */ /* */ /* This function is a stepping stone between ipf_queueflush() and */ /* ipf_state_del(). It is used so we can provide a uniform interface via */ /* the ipf_queueflush() function. */ /* ------------------------------------------------------------------------ */ static int ipf_state_flush_entry(ipf_main_softc_t *softc, void *entry) { return ipf_state_del(softc, entry, ISL_FLUSH); } /* ------------------------------------------------------------------------ */ /* Function: ipf_tcp_age */ /* Returns: int - 1 == state transition made, 0 == no change (rejected) */ /* Parameters: tqe(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 */ /* ok(I) - can we advance state */ /* */ /* Rewritten by Arjan de Vet , 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 ipf_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 ipf_tcp_age(ipftqent_t *tqe, fr_info_t *fin, ipftq_t *tqtab, int flags, int ok) { ipf_main_softc_t *softc = fin->fin_main_soft; 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); ostate = tqe->tqe_state[1 - dir]; nstate = tqe->tqe_state[dir]; if (tcpflags & TH_RST) { if (!(tcpflags & TH_PUSH) && !dlen) nstate = IPF_TCPS_CLOSED; else nstate = IPF_TCPS_CLOSE_WAIT; if (ostate <= IPF_TCPS_ESTABLISHED) { tqe->tqe_state[1 - dir] = IPF_TCPS_CLOSE_WAIT; } rval = 1; } else { 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 ipf_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_LAST_ACK; } 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 = 1; break; case IPF_TCPS_LAST_ACK: /* 8 */ if (tcpflags & TH_ACK) { rval = 1; } /* * 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; } else { rval = 2; } break; case IPF_TCPS_CLOSED: /* 11 */ rval = 2; break; default : #if !defined(_KERNEL) 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) { if (ok) tqe->tqe_state[dir] = nstate; if ((tqe->tqe_flags & TQE_RULEBASED) == 0) ipf_movequeue(softc->ipf_ticks, tqe, tqe->tqe_ifq, tqtab + nstate); } return rval; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_log */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* 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 ipf_state_log(ipf_main_softc_t *softc, 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; (void) ipf_log_items(softc, IPL_LOGSTATE, NULL, items, sizes, types, 1); #endif } #ifdef USE_INET6 /* ------------------------------------------------------------------------ */ /* Function: ipf_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 * ipf_checkicmp6matchingstate(fr_info_t *fin) { ipf_main_softc_t *softc = fin->fin_main_soft; ipf_state_softc_t *softs = softc->ipf_state_soft; struct icmp6_hdr *ic6, *oic; 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)) { SBUMPD(ipf_state_stats, iss_icmp_bad); return NULL; } ic6 = fin->fin_dp; oip6 = (ip6_t *)((char *)ic6 + ICMPERR_ICMPHLEN); if (fin->fin_plen < sizeof(*oip6)) { SBUMPD(ipf_state_stats, iss_icmp_short); 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. ipf_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 = htons(fin->fin_dlen - ICMPERR_ICMPHLEN); ofin.fin_flx = FI_NOCKSUM; ofin.fin_ip = (ip_t *)oip6; (void) ipf_makefrip(sizeof(*oip6), (ip_t *)oip6, &ofin); ofin.fin_flx &= ~(FI_BAD|FI_SHORT); oip6->ip6_plen = savelen; pr = ofin.fin_p; /* * an ICMP error can never generate an ICMP error in response. */ if (ofin.fin_flx & FI_ICMPERR) { DT1(iss_icmp6_icmperr, fr_info_t *, &ofin); SBUMP(ipf_state_stats.iss_icmp6_icmperr); return NULL; } if (oip6->ip6_nxt == IPPROTO_ICMPV6) { oic = ofin.fin_dp; /* * 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)) { DT1(iss_icmp6_notinfo, fr_info_t *, &ofin); SBUMP(ipf_state_stats.iss_icmp6_notinfo); 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(&softc->ipf_state); for (isp = &softs->ipf_state_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 = ipf_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 )) { if (!ipf_allowstateicmp(fin, is, &src)) return is; } } } RWLOCK_EXIT(&softc->ipf_state); SBUMPD(ipf_state_stats, iss_icmp6_miss); 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]; tcp = NULL; switch (oip6->ip6_nxt) { case IPPROTO_TCP : case IPPROTO_UDP : tcp = (tcphdr_t *)(oip6 + 1); dport = tcp->th_dport; sport = tcp->th_sport; hv += dport; hv += sport; break; case IPPROTO_ICMPV6 : oic = (struct icmp6_hdr *)(oip6 + 1); hv += oic->icmp6_id; hv += oic->icmp6_seq; break; default : break; } hv = DOUBLE_HASH(hv); READ_ENTER(&softc->ipf_state); for (isp = &softs->ipf_state_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 = ipf_matchsrcdst(&ofin, is, &src, &dst, tcp, FI_ICMPCMP); if ((is != NULL) && (ipf_allowstateicmp(fin, is, &src) == 0)) return is; } RWLOCK_EXIT(&softc->ipf_state); SBUMPD(ipf_state_stats, iss_icmp_miss); return NULL; } #endif /* ------------------------------------------------------------------------ */ /* Function: ipf_sttab_init */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* tqp(I) - pointer to an array of timeout queues for TCP */ /* */ /* Initialise the array of timeout queues for TCP. */ /* ------------------------------------------------------------------------ */ void ipf_sttab_init(ipf_main_softc_t *softc, ipftq_t *tqp) { int i; for (i = IPF_TCP_NSTATES - 1; i >= 0; i--) { IPFTQ_INIT(&tqp[i], 0, "ipftq tcp tab"); tqp[i].ifq_next = tqp + i + 1; } tqp[IPF_TCP_NSTATES - 1].ifq_next = NULL; tqp[IPF_TCPS_CLOSED].ifq_ttl = softc->ipf_tcpclosed; tqp[IPF_TCPS_LISTEN].ifq_ttl = softc->ipf_tcptimeout; tqp[IPF_TCPS_SYN_SENT].ifq_ttl = softc->ipf_tcpsynsent; tqp[IPF_TCPS_SYN_RECEIVED].ifq_ttl = softc->ipf_tcpsynrecv; tqp[IPF_TCPS_ESTABLISHED].ifq_ttl = softc->ipf_tcpidletimeout; tqp[IPF_TCPS_CLOSE_WAIT].ifq_ttl = softc->ipf_tcphalfclosed; tqp[IPF_TCPS_FIN_WAIT_1].ifq_ttl = softc->ipf_tcphalfclosed; tqp[IPF_TCPS_CLOSING].ifq_ttl = softc->ipf_tcptimeout; tqp[IPF_TCPS_LAST_ACK].ifq_ttl = softc->ipf_tcplastack; tqp[IPF_TCPS_FIN_WAIT_2].ifq_ttl = softc->ipf_tcpclosewait; tqp[IPF_TCPS_TIME_WAIT].ifq_ttl = softc->ipf_tcptimewait; tqp[IPF_TCPS_HALF_ESTAB].ifq_ttl = softc->ipf_tcptimeout; } /* ------------------------------------------------------------------------ */ /* Function: ipf_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 ipf_sttab_destroy(ipftq_t *tqp) { int i; for (i = IPF_TCP_NSTATES - 1; i >= 0; i--) MUTEX_DESTROY(&tqp[i].ifq_lock); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_deref */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* 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 ipf_state_deref(ipf_main_softc_t *softc, ipstate_t **isp) { ipstate_t *is = *isp; 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)) { ipf_state_del(softc, is, ISL_EXPIRE); } #endif return; } MUTEX_EXIT(&is->is_lock); WRITE_ENTER(&softc->ipf_state); ipf_state_del(softc, is, ISL_ORPHAN); RWLOCK_EXIT(&softc->ipf_state); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_setqueue */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to soft context main structure */ /* 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 ipf_state_setqueue(ipf_main_softc_t *softc, ipstate_t *is, int rev) { ipf_state_softc_t *softs = softc->ipf_state_soft; 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 = &softs->ipf_state_icmpacktq; else nifq = &softs->ipf_state_icmptq; break; #endif case IPPROTO_ICMP : if (rev == 1) nifq = &softs->ipf_state_icmpacktq; else nifq = &softs->ipf_state_icmptq; break; case IPPROTO_TCP : nifq = softs->ipf_state_tcptq + is->is_state[rev]; break; case IPPROTO_UDP : if (rev == 1) nifq = &softs->ipf_state_udpacktq; else nifq = &softs->ipf_state_udptq; break; default : nifq = &softs->ipf_state_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) ipf_movequeue(softc->ipf_ticks, &is->is_sti, oifq, nifq); else ipf_queueappend(softc->ipf_ticks, &is->is_sti, nifq, is); return; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_iter */ /* Returns: int - 0 == success, else error */ /* Parameters: softc(I) - pointer to main soft context */ /* token(I) - pointer to ipftoken structure */ /* itp(I) - pointer to ipfgeniter structure */ /* obj(I) - pointer to data description structure */ /* */ /* This function handles the SIOCGENITER ioctl for the state tables and */ /* walks through the list of entries in the state table list (softs->ipf_state_list.) */ /* ------------------------------------------------------------------------ */ static int ipf_state_iter(ipf_main_softc_t *softc, ipftoken_t *token, ipfgeniter_t *itp, ipfobj_t *obj) { ipf_state_softc_t *softs = softc->ipf_state_soft; ipstate_t *is, *next, zero; int error; if (itp->igi_data == NULL) { IPFERROR(100026); return EFAULT; } if (itp->igi_nitems < 1) { IPFERROR(100027); return ENOSPC; } if (itp->igi_type != IPFGENITER_STATE) { IPFERROR(100028); return EINVAL; } is = token->ipt_data; if (is == (void *)-1) { IPFERROR(100029); return ESRCH; } error = 0; obj->ipfo_type = IPFOBJ_IPSTATE; obj->ipfo_size = sizeof(ipstate_t); READ_ENTER(&softc->ipf_state); is = token->ipt_data; if (is == NULL) { next = softs->ipf_state_list; } else { next = is->is_next; } /* * 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 (next != NULL) { MUTEX_ENTER(&next->is_lock); next->is_ref++; MUTEX_EXIT(&next->is_lock); token->ipt_data = next; } else { bzero(&zero, sizeof(zero)); next = &zero; token->ipt_data = NULL; } if (next->is_next == NULL) ipf_token_mark_complete(token); RWLOCK_EXIT(&softc->ipf_state); obj->ipfo_ptr = itp->igi_data; error = ipf_outobjk(softc, obj, next); if (is != NULL) ipf_state_deref(softc, &is); return error; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_gettable */ /* Returns: int - 0 = success, else error */ /* Parameters: softc(I) - pointer to main soft context */ /* softs(I) - pointer to state context structure */ /* 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 ipf_state_gettable(ipf_main_softc_t *softc, ipf_state_softc_t *softs, char *data) { ipftable_t table; int error; error = ipf_inobj(softc, data, NULL, &table, IPFOBJ_GTABLE); if (error != 0) return error; if (table.ita_type != IPFTABLE_BUCKETS) { IPFERROR(100031); return EINVAL; } error = COPYOUT(softs->ipf_state_stats.iss_bucketlen, table.ita_table, softs->ipf_state_size * sizeof(u_int)); if (error != 0) { IPFERROR(100032); error = EFAULT; } return error; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_setpending */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to main soft context */ /* is(I) - pointer to state structure */ /* Locks: ipf_state (read or write) */ /* */ /* Put the state entry on to the pending queue - this queue has a very */ /* short lifetime where items are put that can't be deleted straight away */ /* because of locking issues but we want to delete them ASAP, anyway. */ /* ------------------------------------------------------------------------ */ void ipf_state_setpending(ipf_main_softc_t *softc, ipstate_t *is) { ipf_state_softc_t *softs = softc->ipf_state_soft; ipftq_t *oifq; oifq = is->is_sti.tqe_ifq; if (oifq != NULL) ipf_movequeue(softc->ipf_ticks, &is->is_sti, oifq, &softs->ipf_state_pending); else ipf_queueappend(softc->ipf_ticks, &is->is_sti, &softs->ipf_state_pending, is); MUTEX_ENTER(&is->is_lock); if (is->is_me != NULL) { *is->is_me = NULL; is->is_me = NULL; is->is_ref--; } MUTEX_EXIT(&is->is_lock); } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_matchflush */ /* Returns: Nil */ /* Parameters: softc(I) - pointer to main soft context */ /* data(I) - pointer to state structure */ /* Locks: ipf_state (read or write) */ /* */ /* Flush all entries from the list of state entries that match the */ /* properties in the array loaded. */ /* ------------------------------------------------------------------------ */ int ipf_state_matchflush(ipf_main_softc_t *softc, void *data) { ipf_state_softc_t *softs = softc->ipf_state_soft; int *array, flushed, error; ipstate_t *state, *statenext; ipfobj_t obj; error = ipf_matcharray_load(softc, data, &obj, &array); if (error != 0) return error; flushed = 0; for (state = softs->ipf_state_list; state != NULL; state = statenext) { statenext = state->is_next; if (ipf_state_matcharray(state, array, softc->ipf_ticks) == 0) { ipf_state_del(softc, state, ISL_FLUSH); flushed++; } } obj.ipfo_retval = flushed; error = BCOPYOUT(&obj, data, sizeof(obj)); KFREES(array, array[0] * sizeof(*array)); return error; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_matcharray */ /* Returns: int - 0 = no match, 1 = match */ /* Parameters: state(I) - pointer to state structure */ /* array(I) - pointer to ipf matching expression */ /* ticks(I) - current value of ipfilter tick timer */ /* Locks: ipf_state (read or write) */ /* */ /* Compare a state entry with the match array passed in and return a value */ /* to indicate whether or not the matching was successful. */ /* ------------------------------------------------------------------------ */ static int ipf_state_matcharray(ipstate_t *state, int *array, u_long ticks) { int i, n, *x, rv, p; ipfexp_t *e; rv = 0; n = array[0]; x = array + 1; for (; n > 0; x += 3 + x[3], rv = 0) { e = (ipfexp_t *)x; n -= e->ipfe_size; if (x[0] == IPF_EXP_END) break; /* * If we need to match the protocol and that doesn't match, * don't even both with the instruction array. */ p = e->ipfe_cmd >> 16; if ((p != 0) && (p != state->is_p)) break; switch (e->ipfe_cmd) { case IPF_EXP_IP_PR : for (i = 0; !rv && i < e->ipfe_narg; i++) { rv |= (state->is_p == e->ipfe_arg0[i]); } break; case IPF_EXP_IP_SRCADDR : if (state->is_v != 4) break; for (i = 0; !rv && i < e->ipfe_narg; i++) { rv |= ((state->is_saddr & e->ipfe_arg0[i * 2 + 1]) == e->ipfe_arg0[i * 2]); } break; case IPF_EXP_IP_DSTADDR : if (state->is_v != 4) break; for (i = 0; !rv && i < e->ipfe_narg; i++) { rv |= ((state->is_daddr & e->ipfe_arg0[i * 2 + 1]) == e->ipfe_arg0[i * 2]); } break; case IPF_EXP_IP_ADDR : if (state->is_v != 4) break; for (i = 0; !rv && i < e->ipfe_narg; i++) { rv |= ((state->is_saddr & e->ipfe_arg0[i * 2 + 1]) == e->ipfe_arg0[i * 2]) || ((state->is_daddr & e->ipfe_arg0[i * 2 + 1]) == e->ipfe_arg0[i * 2]); } break; #ifdef USE_INET6 case IPF_EXP_IP6_SRCADDR : if (state->is_v != 6) break; for (i = 0; !rv && i < x[3]; i++) { rv |= IP6_MASKEQ(&state->is_src.in6, &e->ipfe_arg0[i * 8 + 4], &e->ipfe_arg0[i * 8]); } break; case IPF_EXP_IP6_DSTADDR : if (state->is_v != 6) break; for (i = 0; !rv && i < x[3]; i++) { rv |= IP6_MASKEQ(&state->is_dst.in6, &e->ipfe_arg0[i * 8 + 4], &e->ipfe_arg0[i * 8]); } break; case IPF_EXP_IP6_ADDR : if (state->is_v != 6) break; for (i = 0; !rv && i < x[3]; i++) { rv |= IP6_MASKEQ(&state->is_src.in6, &e->ipfe_arg0[i * 8 + 4], &e->ipfe_arg0[i * 8]) || IP6_MASKEQ(&state->is_dst.in6, &e->ipfe_arg0[i * 8 + 4], &e->ipfe_arg0[i * 8]); } break; #endif case IPF_EXP_UDP_PORT : case IPF_EXP_TCP_PORT : for (i = 0; !rv && i < e->ipfe_narg; i++) { rv |= (state->is_sport == e->ipfe_arg0[i]) || (state->is_dport == e->ipfe_arg0[i]); } break; case IPF_EXP_UDP_SPORT : case IPF_EXP_TCP_SPORT : for (i = 0; !rv && i < e->ipfe_narg; i++) { rv |= (state->is_sport == e->ipfe_arg0[i]); } break; case IPF_EXP_UDP_DPORT : case IPF_EXP_TCP_DPORT : for (i = 0; !rv && i < e->ipfe_narg; i++) { rv |= (state->is_dport == e->ipfe_arg0[i]); } break; case IPF_EXP_TCP_STATE : for (i = 0; !rv && i < e->ipfe_narg; i++) { rv |= (state->is_state[0] == e->ipfe_arg0[i]) || (state->is_state[1] == e->ipfe_arg0[i]); } break; case IPF_EXP_IDLE_GT : rv |= (ticks - state->is_touched > e->ipfe_arg0[0]); break; } /* * Factor in doing a negative match. */ rv ^= e->ipfe_not; if (rv == 0) break; } return rv; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_settimeout */ /* Returns: int 0 = success, else failure */ /* Parameters: softc(I) - pointer to main soft context */ /* t(I) - pointer to tuneable being changed */ /* p(I) - pointer to the new value */ /* */ /* Sets a timeout value for one of the many timeout queues. We find the */ /* correct queue using a somewhat manual process of comparing the timeout */ /* names for each specific value available and calling ipf_apply_timeout on */ /* that queue so that all of the items on it are updated accordingly. */ /* ------------------------------------------------------------------------ */ int ipf_state_settimeout(struct ipf_main_softc_s *softc, ipftuneable_t *t, ipftuneval_t *p) { ipf_state_softc_t *softs = softc->ipf_state_soft; /* * In case there is nothing to do... */ if (*t->ipft_pint == p->ipftu_int) return 0; if (!strncmp(t->ipft_name, "tcp_", 4)) return ipf_settimeout_tcp(t, p, softs->ipf_state_tcptq); if (!strcmp(t->ipft_name, "udp_timeout")) { ipf_apply_timeout(&softs->ipf_state_udptq, p->ipftu_int); } else if (!strcmp(t->ipft_name, "udp_ack_timeout")) { ipf_apply_timeout(&softs->ipf_state_udpacktq, p->ipftu_int); } else if (!strcmp(t->ipft_name, "icmp_timeout")) { ipf_apply_timeout(&softs->ipf_state_icmptq, p->ipftu_int); } else if (!strcmp(t->ipft_name, "icmp_ack_timeout")) { ipf_apply_timeout(&softs->ipf_state_icmpacktq, p->ipftu_int); } else if (!strcmp(t->ipft_name, "ip_timeout")) { ipf_apply_timeout(&softs->ipf_state_iptq, p->ipftu_int); } else { IPFERROR(100034); return ESRCH; } /* * Update the tuneable being set. */ *t->ipft_pint = p->ipftu_int; return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_rehash */ /* Returns: int 0 = success, else failure */ /* Parameters: softc(I) - pointer to main soft context */ /* t(I) - pointer to tuneable being changed */ /* p(I) - pointer to the new value */ /* */ /* To change the size of the state hash table at runtime, a new table has */ /* to be allocated and then all of the existing entries put in it, bumping */ /* up the bucketlength for it as we go along. */ /* ------------------------------------------------------------------------ */ int ipf_state_rehash(ipf_main_softc_t *softc, ipftuneable_t *t, ipftuneval_t *p) { ipf_state_softc_t *softs = softc->ipf_state_soft; ipstate_t **newtab, *is; u_long *newseed; u_int *bucketlens; u_int maxbucket; u_int newsize; u_int hv; int i; newsize = p->ipftu_int; /* * In case there is nothing to do... */ if (newsize == softs->ipf_state_size) return 0; KMALLOCS(newtab, ipstate_t **, newsize * sizeof(ipstate_t *)); if (newtab == NULL) { IPFERROR(100035); return ENOMEM; } KMALLOCS(bucketlens, u_int *, newsize * sizeof(u_int)); if (bucketlens == NULL) { KFREES(newtab, newsize * sizeof(*softs->ipf_state_table)); IPFERROR(100036); return ENOMEM; } newseed = ipf_state_seed_alloc(newsize, softs->ipf_state_max); if (newseed == NULL) { KFREES(bucketlens, newsize * sizeof(*bucketlens)); KFREES(newtab, newsize * sizeof(*newtab)); IPFERROR(100037); return ENOMEM; } for (maxbucket = 0, i = newsize; i > 0; i >>= 1) maxbucket++; maxbucket *= 2; bzero((char *)newtab, newsize * sizeof(ipstate_t *)); bzero((char *)bucketlens, newsize * sizeof(u_int)); WRITE_ENTER(&softc->ipf_state); if (softs->ipf_state_table != NULL) { KFREES(softs->ipf_state_table, softs->ipf_state_size * sizeof(*softs->ipf_state_table)); } softs->ipf_state_table = newtab; if (softs->ipf_state_seed != NULL) { KFREES(softs->ipf_state_seed, softs->ipf_state_size * sizeof(*softs->ipf_state_seed)); } softs->ipf_state_seed = newseed; if (softs->ipf_state_stats.iss_bucketlen != NULL) { KFREES(softs->ipf_state_stats.iss_bucketlen, softs->ipf_state_size * sizeof(u_int)); } softs->ipf_state_stats.iss_bucketlen = bucketlens; softs->ipf_state_maxbucket = maxbucket; softs->ipf_state_size = newsize; /* * Walk through the entire list of state table entries and put them * in the new state table, somewhere. Because we have a new table, * we need to restart the counter of how many chains are in use. */ softs->ipf_state_stats.iss_inuse = 0; for (is = softs->ipf_state_list; is != NULL; is = is->is_next) { is->is_hnext = NULL; is->is_phnext = NULL; hv = is->is_hv % softs->ipf_state_size; if (softs->ipf_state_table[hv] != NULL) softs->ipf_state_table[hv]->is_phnext = &is->is_hnext; else softs->ipf_state_stats.iss_inuse++; is->is_phnext = softs->ipf_state_table + hv; is->is_hnext = softs->ipf_state_table[hv]; softs->ipf_state_table[hv] = is; softs->ipf_state_stats.iss_bucketlen[hv]++; } RWLOCK_EXIT(&softc->ipf_state); return 0; } /* ------------------------------------------------------------------------ */ /* Function: ipf_state_add_tq */ /* Returns: ipftq_t * - NULL = failure, else pointer to new timeout */ /* queue */ /* Parameters: softc(I) - pointer to main soft context */ /* ttl(I) - pointer to the ttl for the new queue */ /* */ /* Request a pointer to a timeout queue that has a ttl as given by the */ /* value being passed in. The timeout queue is added tot the list of those */ /* used internally for stateful filtering. */ /* ------------------------------------------------------------------------ */ ipftq_t * ipf_state_add_tq(ipf_main_softc_t *softc, int ttl) { ipf_state_softc_t *softs = softc->ipf_state_soft; return ipf_addtimeoutqueue(softc, &softs->ipf_state_usertq, ttl); } #ifndef _KERNEL /* * Display the built up state table rules and mapping entries. */ void ipf_state_dump(ipf_main_softc_t *softc, void *arg) { ipf_state_softc_t *softs = arg; ipstate_t *ips; printf("List of active state sessions:\n"); for (ips = softs->ipf_state_list; ips != NULL; ) ips = printstate(ips, opts & (OPT_DEBUG|OPT_VERBOSE), softc->ipf_ticks); } #endif