/*- * SPDX-License-Identifier: BSD-2-Clause * * Copyright (c) 2017-2025 Yandex LLC * Copyright (c) 2017-2025 Andrey V. Elsukov * Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include "opt_inet.h" #include "opt_inet6.h" #include "opt_ipfw.h" #ifndef INET #error IPFIREWALL requires INET. #endif /* INET */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* IN6_ARE_ADDR_EQUAL */ #ifdef INET6 #include #include #include #endif #include #include /* XXX for in_cksum */ #ifdef MAC #include #endif /* * Description of dynamic states. * * Dynamic states are stored in lists accessed through a hash tables * whose size is curr_dyn_buckets. This value can be modified through * the sysctl variable dyn_buckets. * * Currently there are four tables: dyn_ipv4, dyn_ipv6, dyn_ipv4_parent, * and dyn_ipv6_parent. * * When a packet is received, its address fields hashed, then matched * against the entries in the corresponding list by addr_type. * Dynamic states can be used for different purposes: * + stateful rules; * + enforcing limits on the number of sessions; * + in-kernel NAT (not implemented yet) * * The lifetime of dynamic states is regulated by dyn_*_lifetime, * measured in seconds and depending on the flags. * * The total number of dynamic states is equal to UMA zone items count. * The max number of dynamic states is dyn_max. When we reach * the maximum number of rules we do not create anymore. This is * done to avoid consuming too much memory, but also too much * time when searching on each packet (ideally, we should try instead * to put a limit on the length of the list on each bucket...). * * Each state holds a pointer to the parent ipfw rule so we know what * action to perform. Dynamic rules are removed when the parent rule is * deleted. * * There are some limitations with dynamic rules -- we do not * obey the 'randomized match', and we do not do multiple * passes through the firewall. XXX check the latter!!! */ /* By default use jenkins hash function */ #define IPFIREWALL_JENKINSHASH #define DYN_COUNTER_INC(d, dir, pktlen) do { \ (d)->pcnt_ ## dir++; \ (d)->bcnt_ ## dir += pktlen; \ } while (0) #define DYN_REFERENCED 0x01 /* * DYN_REFERENCED flag is used to show that state keeps reference to named * object, and this reference should be released when state becomes expired. */ struct dyn_data { void *parent; /* pointer to parent rule */ uint32_t chain_id; /* cached ruleset id */ uint32_t f_pos; /* cached rule index */ uint32_t hashval; /* hash value used for hash resize */ uint16_t fibnum; /* fib used to send keepalives */ uint8_t _pad; uint8_t flags; /* internal flags */ uint32_t rulenum; /* parent rule number */ uint32_t ruleid; /* parent rule id */ uint32_t state; /* TCP session state and flags */ uint32_t ack_fwd; /* most recent ACKs in forward */ uint32_t ack_rev; /* and reverse direction (used */ /* to generate keepalives) */ uint32_t sync; /* synchronization time */ uint32_t expire; /* expire time */ uint64_t pcnt_fwd; /* packets counter in forward */ uint64_t bcnt_fwd; /* bytes counter in forward */ uint64_t pcnt_rev; /* packets counter in reverse */ uint64_t bcnt_rev; /* bytes counter in reverse */ }; #define DPARENT_COUNT_DEC(p) do { \ MPASS(p->count > 0); \ ck_pr_dec_32(&(p)->count); \ } while (0) #define DPARENT_COUNT_INC(p) ck_pr_inc_32(&(p)->count) #define DPARENT_COUNT(p) ck_pr_load_32(&(p)->count) struct dyn_parent { void *parent; /* pointer to parent rule */ uint32_t count; /* number of linked states */ uint32_t rulenum; /* parent rule number */ uint32_t ruleid; /* parent rule id */ uint32_t hashval; /* hash value used for hash resize */ uint32_t expire; /* expire time */ }; struct dyn_ipv4_state { uint8_t type; /* State type */ uint8_t proto; /* UL Protocol */ uint16_t spare; uint32_t kidx; /* named object index */ uint16_t sport, dport; /* ULP source and destination ports */ in_addr_t src, dst; /* IPv4 source and destination */ union { struct dyn_data *data; struct dyn_parent *limit; }; CK_SLIST_ENTRY(dyn_ipv4_state) entry; SLIST_ENTRY(dyn_ipv4_state) expired; }; CK_SLIST_HEAD(dyn_ipv4ck_slist, dyn_ipv4_state); VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4); VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4_parent); SLIST_HEAD(dyn_ipv4_slist, dyn_ipv4_state); VNET_DEFINE_STATIC(struct dyn_ipv4_slist, dyn_expired_ipv4); #define V_dyn_ipv4 VNET(dyn_ipv4) #define V_dyn_ipv4_parent VNET(dyn_ipv4_parent) #define V_dyn_expired_ipv4 VNET(dyn_expired_ipv4) #ifdef INET6 struct dyn_ipv6_state { uint8_t type; /* State type */ uint8_t proto; /* UL Protocol */ uint16_t kidx; /* named object index */ uint16_t sport, dport; /* ULP source and destination ports */ struct in6_addr src, dst; /* IPv6 source and destination */ uint32_t zoneid; /* IPv6 scope zone id */ union { struct dyn_data *data; struct dyn_parent *limit; }; CK_SLIST_ENTRY(dyn_ipv6_state) entry; SLIST_ENTRY(dyn_ipv6_state) expired; }; CK_SLIST_HEAD(dyn_ipv6ck_slist, dyn_ipv6_state); VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6); VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6_parent); SLIST_HEAD(dyn_ipv6_slist, dyn_ipv6_state); VNET_DEFINE_STATIC(struct dyn_ipv6_slist, dyn_expired_ipv6); #define V_dyn_ipv6 VNET(dyn_ipv6) #define V_dyn_ipv6_parent VNET(dyn_ipv6_parent) #define V_dyn_expired_ipv6 VNET(dyn_expired_ipv6) #endif /* INET6 */ /* * Per-CPU pointer indicates that specified state is currently in use * and must not be reclaimed by expiration callout. */ static void **dyn_hp_cache; DPCPU_DEFINE_STATIC(void *, dyn_hp); #define DYNSTATE_GET(cpu) ck_pr_load_ptr(DPCPU_ID_PTR((cpu), dyn_hp)) #define DYNSTATE_PROTECT(v) ck_pr_store_ptr(DPCPU_PTR(dyn_hp), (v)) #define DYNSTATE_RELEASE() DYNSTATE_PROTECT(NULL) #define DYNSTATE_CRITICAL_ENTER() critical_enter() #define DYNSTATE_CRITICAL_EXIT() do { \ DYNSTATE_RELEASE(); \ critical_exit(); \ } while (0); /* * We keep two version numbers, one is updated when new entry added to * the list. Second is updated when an entry deleted from the list. * Versions are updated under bucket lock. * * Bucket "add" version number is used to know, that in the time between * state lookup (i.e. ipfw_dyn_lookup_state()) and the followed state * creation (i.e. ipfw_dyn_install_state()) another concurrent thread did * not install some state in this bucket. Using this info we can avoid * additional state lookup, because we are sure that we will not install * the state twice. * * Also doing the tracking of bucket "del" version during lookup we can * be sure, that state entry was not unlinked and freed in time between * we read the state pointer and protect it with hazard pointer. * * An entry unlinked from CK list keeps unchanged until it is freed. * Unlinked entries are linked into expired lists using "expired" field. */ /* * dyn_expire_lock is used to protect access to dyn_expired_xxx lists. * dyn_bucket_lock is used to get write access to lists in specific bucket. * Currently one dyn_bucket_lock is used for all ipv4, ipv4_parent, ipv6, * and ipv6_parent lists. */ VNET_DEFINE_STATIC(struct mtx, dyn_expire_lock); VNET_DEFINE_STATIC(struct mtx *, dyn_bucket_lock); #define V_dyn_expire_lock VNET(dyn_expire_lock) #define V_dyn_bucket_lock VNET(dyn_bucket_lock) /* * Bucket's add/delete generation versions. */ VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_add); VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_del); VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_add); VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_del); #define V_dyn_ipv4_add VNET(dyn_ipv4_add) #define V_dyn_ipv4_del VNET(dyn_ipv4_del) #define V_dyn_ipv4_parent_add VNET(dyn_ipv4_parent_add) #define V_dyn_ipv4_parent_del VNET(dyn_ipv4_parent_del) #ifdef INET6 VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_add); VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_del); VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_add); VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_del); #define V_dyn_ipv6_add VNET(dyn_ipv6_add) #define V_dyn_ipv6_del VNET(dyn_ipv6_del) #define V_dyn_ipv6_parent_add VNET(dyn_ipv6_parent_add) #define V_dyn_ipv6_parent_del VNET(dyn_ipv6_parent_del) #endif /* INET6 */ #define DYN_BUCKET(h, b) ((h) & (b - 1)) #define DYN_BUCKET_VERSION(b, v) ck_pr_load_32(&V_dyn_ ## v[(b)]) #define DYN_BUCKET_VERSION_BUMP(b, v) ck_pr_inc_32(&V_dyn_ ## v[(b)]) #define DYN_BUCKET_LOCK_INIT(lock, b) \ mtx_init(&lock[(b)], "IPFW dynamic bucket", NULL, MTX_DEF) #define DYN_BUCKET_LOCK_DESTROY(lock, b) mtx_destroy(&lock[(b)]) #define DYN_BUCKET_LOCK(b) mtx_lock(&V_dyn_bucket_lock[(b)]) #define DYN_BUCKET_UNLOCK(b) mtx_unlock(&V_dyn_bucket_lock[(b)]) #define DYN_BUCKET_ASSERT(b) mtx_assert(&V_dyn_bucket_lock[(b)], MA_OWNED) #define DYN_EXPIRED_LOCK_INIT() \ mtx_init(&V_dyn_expire_lock, "IPFW expired states list", NULL, MTX_DEF) #define DYN_EXPIRED_LOCK_DESTROY() mtx_destroy(&V_dyn_expire_lock) #define DYN_EXPIRED_LOCK() mtx_lock(&V_dyn_expire_lock) #define DYN_EXPIRED_UNLOCK() mtx_unlock(&V_dyn_expire_lock) VNET_DEFINE_STATIC(uint32_t, dyn_buckets_max); VNET_DEFINE_STATIC(uint32_t, curr_dyn_buckets); VNET_DEFINE_STATIC(struct callout, dyn_timeout); #define V_dyn_buckets_max VNET(dyn_buckets_max) #define V_curr_dyn_buckets VNET(curr_dyn_buckets) #define V_dyn_timeout VNET(dyn_timeout) /* Maximum length of states chain in a bucket */ VNET_DEFINE_STATIC(uint32_t, curr_max_length); #define V_curr_max_length VNET(curr_max_length) VNET_DEFINE_STATIC(uint32_t, dyn_keep_states); #define V_dyn_keep_states VNET(dyn_keep_states) VNET_DEFINE_STATIC(uma_zone_t, dyn_data_zone); VNET_DEFINE_STATIC(uma_zone_t, dyn_parent_zone); VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv4_zone); #ifdef INET6 VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv6_zone); #define V_dyn_ipv6_zone VNET(dyn_ipv6_zone) #endif /* INET6 */ #define V_dyn_data_zone VNET(dyn_data_zone) #define V_dyn_parent_zone VNET(dyn_parent_zone) #define V_dyn_ipv4_zone VNET(dyn_ipv4_zone) /* * Timeouts for various events in handing dynamic rules. */ VNET_DEFINE_STATIC(uint32_t, dyn_ack_lifetime); VNET_DEFINE_STATIC(uint32_t, dyn_syn_lifetime); VNET_DEFINE_STATIC(uint32_t, dyn_fin_lifetime); VNET_DEFINE_STATIC(uint32_t, dyn_rst_lifetime); VNET_DEFINE_STATIC(uint32_t, dyn_udp_lifetime); VNET_DEFINE_STATIC(uint32_t, dyn_short_lifetime); #define V_dyn_ack_lifetime VNET(dyn_ack_lifetime) #define V_dyn_syn_lifetime VNET(dyn_syn_lifetime) #define V_dyn_fin_lifetime VNET(dyn_fin_lifetime) #define V_dyn_rst_lifetime VNET(dyn_rst_lifetime) #define V_dyn_udp_lifetime VNET(dyn_udp_lifetime) #define V_dyn_short_lifetime VNET(dyn_short_lifetime) /* * Keepalives are sent if dyn_keepalive is set. They are sent every * dyn_keepalive_period seconds, in the last dyn_keepalive_interval * seconds of lifetime of a rule. * dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower * than dyn_keepalive_period. */ VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_interval); VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_period); VNET_DEFINE_STATIC(uint32_t, dyn_keepalive); VNET_DEFINE_STATIC(time_t, dyn_keepalive_last); #define V_dyn_keepalive_interval VNET(dyn_keepalive_interval) #define V_dyn_keepalive_period VNET(dyn_keepalive_period) #define V_dyn_keepalive VNET(dyn_keepalive) #define V_dyn_keepalive_last VNET(dyn_keepalive_last) VNET_DEFINE_STATIC(uint32_t, dyn_max); /* max # of dynamic states */ VNET_DEFINE_STATIC(uint32_t, dyn_count); /* number of states */ VNET_DEFINE_STATIC(uint32_t, dyn_parent_max); /* max # of parent states */ VNET_DEFINE_STATIC(uint32_t, dyn_parent_count); /* number of parent states */ #define V_dyn_max VNET(dyn_max) #define V_dyn_count VNET(dyn_count) #define V_dyn_parent_max VNET(dyn_parent_max) #define V_dyn_parent_count VNET(dyn_parent_count) #define DYN_COUNT_DEC(name) do { \ MPASS((V_ ## name) > 0); \ ck_pr_dec_32(&(V_ ## name)); \ } while (0) #define DYN_COUNT_INC(name) ck_pr_inc_32(&(V_ ## name)) #define DYN_COUNT(name) ck_pr_load_32(&(V_ ## name)) static time_t last_log; /* Log ratelimiting */ /* * Get/set maximum number of dynamic states in given VNET instance. */ static int sysctl_dyn_max(SYSCTL_HANDLER_ARGS) { uint32_t nstates; int error; nstates = V_dyn_max; error = sysctl_handle_32(oidp, &nstates, 0, req); /* Read operation or some error */ if ((error != 0) || (req->newptr == NULL)) return (error); V_dyn_max = nstates; uma_zone_set_max(V_dyn_data_zone, V_dyn_max); return (0); } static int sysctl_dyn_parent_max(SYSCTL_HANDLER_ARGS) { uint32_t nstates; int error; nstates = V_dyn_parent_max; error = sysctl_handle_32(oidp, &nstates, 0, req); /* Read operation or some error */ if ((error != 0) || (req->newptr == NULL)) return (error); V_dyn_parent_max = nstates; uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max); return (0); } static int sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS) { uint32_t nbuckets; int error; nbuckets = V_dyn_buckets_max; error = sysctl_handle_32(oidp, &nbuckets, 0, req); /* Read operation or some error */ if ((error != 0) || (req->newptr == NULL)) return (error); if (nbuckets > 256) V_dyn_buckets_max = 1 << fls(nbuckets - 1); else return (EINVAL); return (0); } SYSCTL_DECL(_net_inet_ip_fw); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_count), 0, "Current number of dynamic states."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_parent_count, CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_parent_count), 0, "Current number of parent states. "); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_dyn_buckets), 0, "Current number of buckets for states hash table."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_max_length, CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_max_length), 0, "Current maximum length of states chains in hash buckets."); SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0, sysctl_dyn_buckets, "IU", "Max number of buckets for dynamic states hash table."); SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0, sysctl_dyn_max, "IU", "Max number of dynamic states."); SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_parent_max, CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW | CTLFLAG_NEEDGIANT, 0, 0, sysctl_dyn_parent_max, "IU", "Max number of parent dynamic states."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_ack_lifetime), 0, "Lifetime of dynamic states for TCP ACK."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_syn_lifetime), 0, "Lifetime of dynamic states for TCP SYN."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_fin_lifetime), 0, "Lifetime of dynamic states for TCP FIN."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_rst_lifetime), 0, "Lifetime of dynamic states for TCP RST."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_udp_lifetime), 0, "Lifetime of dynamic states for UDP."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_short_lifetime), 0, "Lifetime of dynamic states for other situations."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keepalive), 0, "Enable keepalives for dynamic states."); SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keep_states, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keep_states), 0, "Do not flush dynamic states on rule deletion"); #ifdef IPFIREWALL_DYNDEBUG #define DYN_DEBUG(fmt, ...) do { \ printf("%s: " fmt "\n", __func__, __VA_ARGS__); \ } while (0) #else #define DYN_DEBUG(fmt, ...) #endif /* !IPFIREWALL_DYNDEBUG */ #ifdef INET6 /* Functions to work with IPv6 states */ static struct dyn_ipv6_state *dyn_lookup_ipv6_state( const struct ipfw_flow_id *, uint32_t, const void *, struct ipfw_dyn_info *, int); static int dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *, uint32_t, const void *, int, uint32_t, uint32_t); static struct dyn_ipv6_state *dyn_alloc_ipv6_state( const struct ipfw_flow_id *, uint32_t, uint32_t, uint8_t); static int dyn_add_ipv6_state(void *, uint32_t, uint32_t, const struct ipfw_flow_id *, uint32_t, const void *, int, uint32_t, struct ipfw_dyn_info *, uint16_t, uint32_t, uint8_t); static void dyn_export_ipv6_state(const struct dyn_ipv6_state *, ipfw_dyn_rule *); static uint32_t dyn_getscopeid(const struct ip_fw_args *); static void dyn_make_keepalive_ipv6(struct mbuf *, const struct in6_addr *, const struct in6_addr *, uint32_t, uint32_t, uint32_t, uint16_t, uint16_t); static void dyn_enqueue_keepalive_ipv6(struct mbufq *, const struct dyn_ipv6_state *); static void dyn_send_keepalive_ipv6(struct ip_fw_chain *); static struct dyn_ipv6_state *dyn_lookup_ipv6_parent( const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint32_t, uint32_t); static struct dyn_ipv6_state *dyn_lookup_ipv6_parent_locked( const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint32_t, uint32_t); static struct dyn_ipv6_state *dyn_add_ipv6_parent(void *, uint32_t, uint32_t, const struct ipfw_flow_id *, uint32_t, uint32_t, uint32_t, uint32_t); #endif /* INET6 */ /* Functions to work with limit states */ static void *dyn_get_parent_state(const struct ipfw_flow_id *, uint32_t, struct ip_fw *, uint32_t, uint32_t, uint32_t); static struct dyn_ipv4_state *dyn_lookup_ipv4_parent( const struct ipfw_flow_id *, const void *, uint32_t, uint32_t, uint32_t); static struct dyn_ipv4_state *dyn_lookup_ipv4_parent_locked( const struct ipfw_flow_id *, const void *, uint32_t, uint32_t, uint32_t); static struct dyn_parent *dyn_alloc_parent(void *, uint32_t, uint32_t, uint32_t); static struct dyn_ipv4_state *dyn_add_ipv4_parent(void *, uint32_t, uint32_t, const struct ipfw_flow_id *, uint32_t, uint32_t, uint32_t); static void dyn_tick(void *); static void dyn_expire_states(struct ip_fw_chain *, ipfw_range_tlv *); static void dyn_free_states(struct ip_fw_chain *); static void dyn_export_parent(const struct dyn_parent *, uint32_t, uint8_t, ipfw_dyn_rule *); static void dyn_export_data(const struct dyn_data *, uint32_t, uint8_t, uint8_t, ipfw_dyn_rule *); static uint32_t dyn_update_tcp_state(struct dyn_data *, const struct ipfw_flow_id *, const struct tcphdr *, int); static void dyn_update_proto_state(struct dyn_data *, const struct ipfw_flow_id *, const void *, int, int); /* Functions to work with IPv4 states */ struct dyn_ipv4_state *dyn_lookup_ipv4_state(const struct ipfw_flow_id *, const void *, struct ipfw_dyn_info *, int); static int dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *, const void *, int, uint32_t, uint32_t); static struct dyn_ipv4_state *dyn_alloc_ipv4_state( const struct ipfw_flow_id *, uint32_t, uint8_t); static int dyn_add_ipv4_state(void *, uint32_t, uint32_t, const struct ipfw_flow_id *, const void *, int, uint32_t, struct ipfw_dyn_info *, uint16_t, uint32_t, uint8_t); static void dyn_export_ipv4_state(const struct dyn_ipv4_state *, ipfw_dyn_rule *); /* * Named states support. */ static char *default_state_name = "default"; struct dyn_state_obj { struct named_object no; char name[64]; }; /* * Classifier callback. * Return 0 if opcode contains object that should be referenced * or rewritten. */ static int dyn_classify(ipfw_insn *cmd0, uint32_t *puidx, uint8_t *ptype) { ipfw_insn_kidx *cmd; if (F_LEN(cmd0) < 2) return (EINVAL); /* * NOTE: ipfw_insn_kidx and ipfw_insn_limit has overlapped kidx * field, so we can use one type to get access to kidx field. */ cmd = insntod(cmd0, kidx); DYN_DEBUG("opcode %u, kidx %u", cmd0->opcode, cmd->kidx); /* Don't rewrite "check-state any" */ if (cmd->kidx == 0 && cmd0->opcode == O_CHECK_STATE) return (1); *puidx = cmd->kidx; *ptype = 0; return (0); } static void dyn_update(ipfw_insn *cmd0, uint32_t idx) { insntod(cmd0, kidx)->kidx = idx; DYN_DEBUG("opcode %u, kidx %u", cmd0->opcode, idx); } static int dyn_findbyname(struct ip_fw_chain *ch, struct tid_info *ti, struct named_object **pno) { ipfw_obj_ntlv *ntlv; const char *name; DYN_DEBUG("uidx %u", ti->uidx); if (ti->uidx != 0) { if (ti->tlvs == NULL) return (EINVAL); /* Search ntlv in the buffer provided by user */ ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx, IPFW_TLV_STATE_NAME); if (ntlv == NULL) return (EINVAL); name = ntlv->name; } else name = default_state_name; /* * Search named object with corresponding name. * Since states objects are global - ignore the set value * and use zero instead. */ *pno = ipfw_objhash_lookup_name_type(CHAIN_TO_SRV(ch), 0, IPFW_TLV_STATE_NAME, name); /* * We always return success here. * The caller will check *pno and mark object as unresolved, * then it will automatically create "default" object. */ return (0); } static struct named_object * dyn_findbykidx(struct ip_fw_chain *ch, uint32_t idx) { DYN_DEBUG("kidx %u", idx); return (ipfw_objhash_lookup_kidx(CHAIN_TO_SRV(ch), idx)); } static int dyn_create(struct ip_fw_chain *ch, struct tid_info *ti, uint32_t *pkidx) { struct namedobj_instance *ni; struct dyn_state_obj *obj; struct named_object *no; ipfw_obj_ntlv *ntlv; char *name; DYN_DEBUG("uidx %u", ti->uidx); if (ti->uidx != 0) { if (ti->tlvs == NULL) return (EINVAL); ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx, IPFW_TLV_STATE_NAME); if (ntlv == NULL) return (EINVAL); name = ntlv->name; } else name = default_state_name; ni = CHAIN_TO_SRV(ch); obj = malloc(sizeof(*obj), M_IPFW, M_WAITOK | M_ZERO); obj->no.name = obj->name; obj->no.etlv = IPFW_TLV_STATE_NAME; strlcpy(obj->name, name, sizeof(obj->name)); IPFW_UH_WLOCK(ch); no = ipfw_objhash_lookup_name_type(ni, 0, IPFW_TLV_STATE_NAME, name); if (no != NULL) { /* * Object is already created. * Just return its kidx and bump refcount. */ *pkidx = no->kidx; no->refcnt++; IPFW_UH_WUNLOCK(ch); free(obj, M_IPFW); DYN_DEBUG("\tfound kidx %u for name '%s'", *pkidx, no->name); return (0); } if (ipfw_objhash_alloc_idx(ni, &obj->no.kidx) != 0) { DYN_DEBUG("\talloc_idx failed for %s", name); IPFW_UH_WUNLOCK(ch); free(obj, M_IPFW); return (ENOSPC); } ipfw_objhash_add(ni, &obj->no); SRV_OBJECT(ch, obj->no.kidx) = obj; obj->no.refcnt++; *pkidx = obj->no.kidx; IPFW_UH_WUNLOCK(ch); DYN_DEBUG("\tcreated kidx %u for name '%s'", *pkidx, name); return (0); } static void dyn_destroy(struct ip_fw_chain *ch, struct named_object *no) { struct dyn_state_obj *obj; IPFW_UH_WLOCK_ASSERT(ch); KASSERT(no->etlv == IPFW_TLV_STATE_NAME, ("%s: wrong object type %u", __func__, no->etlv)); KASSERT(no->refcnt == 1, ("Destroying object '%s' (type %u, idx %u) with refcnt %u", no->name, no->etlv, no->kidx, no->refcnt)); DYN_DEBUG("kidx %u", no->kidx); obj = SRV_OBJECT(ch, no->kidx); SRV_OBJECT(ch, no->kidx) = NULL; ipfw_objhash_del(CHAIN_TO_SRV(ch), no); ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), no->kidx); free(obj, M_IPFW); } static struct opcode_obj_rewrite dyn_opcodes[] = { { O_KEEP_STATE, IPFW_TLV_STATE_NAME, dyn_classify, dyn_update, dyn_findbyname, dyn_findbykidx, dyn_create, dyn_destroy }, { O_CHECK_STATE, IPFW_TLV_STATE_NAME, dyn_classify, dyn_update, dyn_findbyname, dyn_findbykidx, dyn_create, dyn_destroy }, { O_PROBE_STATE, IPFW_TLV_STATE_NAME, dyn_classify, dyn_update, dyn_findbyname, dyn_findbykidx, dyn_create, dyn_destroy }, { O_LIMIT, IPFW_TLV_STATE_NAME, dyn_classify, dyn_update, dyn_findbyname, dyn_findbykidx, dyn_create, dyn_destroy }, }; /* * IMPORTANT: the hash function for dynamic rules must be commutative * in source and destination (ip,port), because rules are bidirectional * and we want to find both in the same bucket. */ #ifndef IPFIREWALL_JENKINSHASH static __inline uint32_t hash_packet(const struct ipfw_flow_id *id) { uint32_t i; #ifdef INET6 if (IS_IP6_FLOW_ID(id)) i = ntohl((id->dst_ip6.__u6_addr.__u6_addr32[2]) ^ (id->dst_ip6.__u6_addr.__u6_addr32[3]) ^ (id->src_ip6.__u6_addr.__u6_addr32[2]) ^ (id->src_ip6.__u6_addr.__u6_addr32[3])); else #endif /* INET6 */ i = (id->dst_ip) ^ (id->src_ip); i ^= (id->dst_port) ^ (id->src_port); return (i); } static __inline uint32_t hash_parent(const struct ipfw_flow_id *id, const void *rule) { return (hash_packet(id) ^ ((uintptr_t)rule)); } #else /* IPFIREWALL_JENKINSHASH */ VNET_DEFINE_STATIC(uint32_t, dyn_hashseed); #define V_dyn_hashseed VNET(dyn_hashseed) static __inline int addrcmp4(const struct ipfw_flow_id *id) { if (id->src_ip < id->dst_ip) return (0); if (id->src_ip > id->dst_ip) return (1); if (id->src_port <= id->dst_port) return (0); return (1); } #ifdef INET6 static __inline int addrcmp6(const struct ipfw_flow_id *id) { int ret; ret = memcmp(&id->src_ip6, &id->dst_ip6, sizeof(struct in6_addr)); if (ret < 0) return (0); if (ret > 0) return (1); if (id->src_port <= id->dst_port) return (0); return (1); } static __inline uint32_t hash_packet6(const struct ipfw_flow_id *id) { struct tuple6 { struct in6_addr addr[2]; uint16_t port[2]; } t6; if (addrcmp6(id) == 0) { t6.addr[0] = id->src_ip6; t6.addr[1] = id->dst_ip6; t6.port[0] = id->src_port; t6.port[1] = id->dst_port; } else { t6.addr[0] = id->dst_ip6; t6.addr[1] = id->src_ip6; t6.port[0] = id->dst_port; t6.port[1] = id->src_port; } return (jenkins_hash32((const uint32_t *)&t6, sizeof(t6) / sizeof(uint32_t), V_dyn_hashseed)); } #endif static __inline uint32_t hash_packet(const struct ipfw_flow_id *id) { struct tuple4 { in_addr_t addr[2]; uint16_t port[2]; } t4; if (IS_IP4_FLOW_ID(id)) { /* All fields are in host byte order */ if (addrcmp4(id) == 0) { t4.addr[0] = id->src_ip; t4.addr[1] = id->dst_ip; t4.port[0] = id->src_port; t4.port[1] = id->dst_port; } else { t4.addr[0] = id->dst_ip; t4.addr[1] = id->src_ip; t4.port[0] = id->dst_port; t4.port[1] = id->src_port; } return (jenkins_hash32((const uint32_t *)&t4, sizeof(t4) / sizeof(uint32_t), V_dyn_hashseed)); } else #ifdef INET6 if (IS_IP6_FLOW_ID(id)) return (hash_packet6(id)); #endif return (0); } static __inline uint32_t hash_parent(const struct ipfw_flow_id *id, const void *rule) { return (jenkins_hash32((const uint32_t *)&rule, sizeof(rule) / sizeof(uint32_t), hash_packet(id))); } #endif /* IPFIREWALL_JENKINSHASH */ /* * Print customizable flow id description via log(9) facility. */ static void print_dyn_rule_flags(const struct ipfw_flow_id *id, int dyn_type, int log_flags, char *prefix, char *postfix) { struct in_addr da; #ifdef INET6 char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN]; #else char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN]; #endif #ifdef INET6 if (IS_IP6_FLOW_ID(id)) { ip6_sprintf(src, &id->src_ip6); ip6_sprintf(dst, &id->dst_ip6); } else #endif { da.s_addr = htonl(id->src_ip); inet_ntop(AF_INET, &da, src, sizeof(src)); da.s_addr = htonl(id->dst_ip); inet_ntop(AF_INET, &da, dst, sizeof(dst)); } log(log_flags, "ipfw: %s type %d %s %d -> %s %d, %d %s\n", prefix, dyn_type, src, id->src_port, dst, id->dst_port, V_dyn_count, postfix); } #define print_dyn_rule(id, dtype, prefix, postfix) \ print_dyn_rule_flags(id, dtype, LOG_DEBUG, prefix, postfix) #define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0) #define TIME_LE(a,b) ((int)((a)-(b)) < 0) #define _SEQ_GE(a,b) ((int)((a)-(b)) >= 0) #define BOTH_SYN (TH_SYN | (TH_SYN << 8)) #define BOTH_FIN (TH_FIN | (TH_FIN << 8)) #define BOTH_RST (TH_RST | (TH_RST << 8)) #define TCP_FLAGS (BOTH_SYN | BOTH_FIN | BOTH_RST) #define ACK_FWD 0x00010000 /* fwd ack seen */ #define ACK_REV 0x00020000 /* rev ack seen */ #define ACK_BOTH (ACK_FWD | ACK_REV) static uint32_t dyn_update_tcp_state(struct dyn_data *data, const struct ipfw_flow_id *pkt, const struct tcphdr *tcp, int dir) { uint32_t ack, expire; uint32_t state, old; uint8_t th_flags; expire = data->expire; old = state = data->state; th_flags = pkt->_flags & (TH_FIN | TH_SYN | TH_RST); state |= (dir == MATCH_FORWARD) ? th_flags: (th_flags << 8); switch (state & TCP_FLAGS) { case TH_SYN: /* opening */ expire = time_uptime + V_dyn_syn_lifetime; break; case BOTH_SYN: /* move to established */ case BOTH_SYN | TH_FIN: /* one side tries to close */ case BOTH_SYN | (TH_FIN << 8): if (tcp == NULL) break; ack = ntohl(tcp->th_ack); if (dir == MATCH_FORWARD) { if (data->ack_fwd == 0 || _SEQ_GE(ack, data->ack_fwd)) { state |= ACK_FWD; if (data->ack_fwd != ack) ck_pr_store_32(&data->ack_fwd, ack); } } else { if (data->ack_rev == 0 || _SEQ_GE(ack, data->ack_rev)) { state |= ACK_REV; if (data->ack_rev != ack) ck_pr_store_32(&data->ack_rev, ack); } } if ((state & ACK_BOTH) == ACK_BOTH) { /* * Set expire time to V_dyn_ack_lifetime only if * we got ACKs for both directions. * We use XOR here to avoid possible state * overwriting in concurrent thread. */ expire = time_uptime + V_dyn_ack_lifetime; ck_pr_xor_32(&data->state, ACK_BOTH); } else if ((data->state & ACK_BOTH) != (state & ACK_BOTH)) ck_pr_or_32(&data->state, state & ACK_BOTH); break; case BOTH_SYN | BOTH_FIN: /* both sides closed */ if (V_dyn_fin_lifetime >= V_dyn_keepalive_period) V_dyn_fin_lifetime = V_dyn_keepalive_period - 1; expire = time_uptime + V_dyn_fin_lifetime; break; default: if (V_dyn_keepalive != 0 && V_dyn_rst_lifetime >= V_dyn_keepalive_period) V_dyn_rst_lifetime = V_dyn_keepalive_period - 1; expire = time_uptime + V_dyn_rst_lifetime; } /* Save TCP state if it was changed */ if ((state & TCP_FLAGS) != (old & TCP_FLAGS)) ck_pr_or_32(&data->state, state & TCP_FLAGS); return (expire); } /* * Update ULP specific state. * For TCP we keep sequence numbers and flags. For other protocols * currently we update only expire time. Packets and bytes counters * are also updated here. */ static void dyn_update_proto_state(struct dyn_data *data, const struct ipfw_flow_id *pkt, const void *ulp, int pktlen, int dir) { uint32_t expire; /* NOTE: we are in critical section here. */ switch (pkt->proto) { case IPPROTO_UDP: case IPPROTO_UDPLITE: expire = time_uptime + V_dyn_udp_lifetime; break; case IPPROTO_TCP: expire = dyn_update_tcp_state(data, pkt, ulp, dir); break; default: expire = time_uptime + V_dyn_short_lifetime; } /* * Expiration timer has the per-second granularity, no need to update * it every time when state is matched. */ if (data->expire != expire) ck_pr_store_32(&data->expire, expire); if (dir == MATCH_FORWARD) DYN_COUNTER_INC(data, fwd, pktlen); else DYN_COUNTER_INC(data, rev, pktlen); } /* * Lookup IPv4 state. * Must be called in critical section. */ struct dyn_ipv4_state * dyn_lookup_ipv4_state(const struct ipfw_flow_id *pkt, const void *ulp, struct ipfw_dyn_info *info, int pktlen) { struct dyn_ipv4_state *s; uint32_t version, bucket; bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets); info->version = DYN_BUCKET_VERSION(bucket, ipv4_add); restart: version = DYN_BUCKET_VERSION(bucket, ipv4_del); CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) { DYNSTATE_PROTECT(s); if (version != DYN_BUCKET_VERSION(bucket, ipv4_del)) goto restart; if (s->proto != pkt->proto) continue; if (info->kidx != 0 && s->kidx != info->kidx) continue; if (s->sport == pkt->src_port && s->dport == pkt->dst_port && s->src == pkt->src_ip && s->dst == pkt->dst_ip) { info->direction = MATCH_FORWARD; break; } if (s->sport == pkt->dst_port && s->dport == pkt->src_port && s->src == pkt->dst_ip && s->dst == pkt->src_ip) { info->direction = MATCH_REVERSE; break; } } if (s != NULL) dyn_update_proto_state(s->data, pkt, ulp, pktlen, info->direction); return (s); } /* * Lookup IPv4 state. * Simplifed version is used to check that matching state doesn't exist. */ static int dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *pkt, const void *ulp, int pktlen, uint32_t bucket, uint32_t kidx) { struct dyn_ipv4_state *s; int dir; dir = MATCH_NONE; DYN_BUCKET_ASSERT(bucket); CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) { if (s->proto != pkt->proto || s->kidx != kidx) continue; if (s->sport == pkt->src_port && s->dport == pkt->dst_port && s->src == pkt->src_ip && s->dst == pkt->dst_ip) { dir = MATCH_FORWARD; break; } if (s->sport == pkt->dst_port && s->dport == pkt->src_port && s->src == pkt->dst_ip && s->dst == pkt->src_ip) { dir = MATCH_REVERSE; break; } } if (s != NULL) dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir); return (s != NULL); } struct dyn_ipv4_state * dyn_lookup_ipv4_parent(const struct ipfw_flow_id *pkt, const void *rule, uint32_t ruleid, uint32_t rulenum, uint32_t hashval) { struct dyn_ipv4_state *s; uint32_t version, bucket; bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); restart: version = DYN_BUCKET_VERSION(bucket, ipv4_parent_del); CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) { DYNSTATE_PROTECT(s); if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_del)) goto restart; /* * NOTE: we do not need to check kidx, because parent rule * can not create states with different kidx. * And parent rule always created for forward direction. */ if (s->limit->parent == rule && s->limit->ruleid == ruleid && s->limit->rulenum == rulenum && s->proto == pkt->proto && s->sport == pkt->src_port && s->dport == pkt->dst_port && s->src == pkt->src_ip && s->dst == pkt->dst_ip) { if (s->limit->expire != time_uptime + V_dyn_short_lifetime) ck_pr_store_32(&s->limit->expire, time_uptime + V_dyn_short_lifetime); break; } } return (s); } static struct dyn_ipv4_state * dyn_lookup_ipv4_parent_locked(const struct ipfw_flow_id *pkt, const void *rule, uint32_t ruleid, uint32_t rulenum, uint32_t bucket) { struct dyn_ipv4_state *s; DYN_BUCKET_ASSERT(bucket); CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) { if (s->limit->parent == rule && s->limit->ruleid == ruleid && s->limit->rulenum == rulenum && s->proto == pkt->proto && s->sport == pkt->src_port && s->dport == pkt->dst_port && s->src == pkt->src_ip && s->dst == pkt->dst_ip) break; } return (s); } #ifdef INET6 static uint32_t dyn_getscopeid(const struct ip_fw_args *args) { /* * If source or destination address is an scopeid address, we need * determine the scope zone id to resolve address scope ambiguity. */ if (IN6_IS_ADDR_LINKLOCAL(&args->f_id.src_ip6) || IN6_IS_ADDR_LINKLOCAL(&args->f_id.dst_ip6)) return (in6_getscopezone(args->ifp, IPV6_ADDR_SCOPE_LINKLOCAL)); return (0); } /* * Lookup IPv6 state. * Must be called in critical section. */ static struct dyn_ipv6_state * dyn_lookup_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *ulp, struct ipfw_dyn_info *info, int pktlen) { struct dyn_ipv6_state *s; uint32_t version, bucket; bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets); info->version = DYN_BUCKET_VERSION(bucket, ipv6_add); restart: version = DYN_BUCKET_VERSION(bucket, ipv6_del); CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) { DYNSTATE_PROTECT(s); if (version != DYN_BUCKET_VERSION(bucket, ipv6_del)) goto restart; if (s->proto != pkt->proto || s->zoneid != zoneid) continue; if (info->kidx != 0 && s->kidx != info->kidx) continue; if (s->sport == pkt->src_port && s->dport == pkt->dst_port && IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) && IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) { info->direction = MATCH_FORWARD; break; } if (s->sport == pkt->dst_port && s->dport == pkt->src_port && IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) && IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) { info->direction = MATCH_REVERSE; break; } } if (s != NULL) dyn_update_proto_state(s->data, pkt, ulp, pktlen, info->direction); return (s); } /* * Lookup IPv6 state. * Simplifed version is used to check that matching state doesn't exist. */ static int dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *ulp, int pktlen, uint32_t bucket, uint32_t kidx) { struct dyn_ipv6_state *s; int dir; dir = MATCH_NONE; DYN_BUCKET_ASSERT(bucket); CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) { if (s->proto != pkt->proto || s->kidx != kidx || s->zoneid != zoneid) continue; if (s->sport == pkt->src_port && s->dport == pkt->dst_port && IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) && IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) { dir = MATCH_FORWARD; break; } if (s->sport == pkt->dst_port && s->dport == pkt->src_port && IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) && IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) { dir = MATCH_REVERSE; break; } } if (s != NULL) dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir); return (s != NULL); } static struct dyn_ipv6_state * dyn_lookup_ipv6_parent(const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *rule, uint32_t ruleid, uint32_t rulenum, uint32_t hashval) { struct dyn_ipv6_state *s; uint32_t version, bucket; bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); restart: version = DYN_BUCKET_VERSION(bucket, ipv6_parent_del); CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) { DYNSTATE_PROTECT(s); if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_del)) goto restart; /* * NOTE: we do not need to check kidx, because parent rule * can not create states with different kidx. * Also parent rule always created for forward direction. */ if (s->limit->parent == rule && s->limit->ruleid == ruleid && s->limit->rulenum == rulenum && s->proto == pkt->proto && s->sport == pkt->src_port && s->dport == pkt->dst_port && s->zoneid == zoneid && IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) && IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) { if (s->limit->expire != time_uptime + V_dyn_short_lifetime) ck_pr_store_32(&s->limit->expire, time_uptime + V_dyn_short_lifetime); break; } } return (s); } static struct dyn_ipv6_state * dyn_lookup_ipv6_parent_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *rule, uint32_t ruleid, uint32_t rulenum, uint32_t bucket) { struct dyn_ipv6_state *s; DYN_BUCKET_ASSERT(bucket); CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) { if (s->limit->parent == rule && s->limit->ruleid == ruleid && s->limit->rulenum == rulenum && s->proto == pkt->proto && s->sport == pkt->src_port && s->dport == pkt->dst_port && s->zoneid == zoneid && IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) && IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) break; } return (s); } #endif /* INET6 */ static int dyn_handle_orphaned(struct ip_fw *old_rule, struct dyn_data *data) { struct ip_fw *rule; const ipfw_insn *cmd, *old_cmd; old_cmd = ACTION_PTR(old_rule); switch (old_cmd->opcode) { case O_SETMARK: case O_SKIPTO: /* * Rule pointer was changed. For O_SKIPTO action it can be * dangerous to keep use old rule. If new rule has the same * action and the same destination number, then use this dynamic * state. Otherwise it is better to create new one. */ rule = V_layer3_chain.map[data->f_pos]; cmd = ACTION_PTR(rule); if (cmd->opcode != old_cmd->opcode || cmd->len != old_cmd->len || cmd->arg1 != old_cmd->arg1 || insntoc(cmd, u32)->d[0] != insntoc(old_cmd, u32)->d[0]) return (-1); break; } return (0); } /* * Lookup dynamic state. * pkt - filled by ipfw_chk() ipfw_flow_id; * ulp - determined by ipfw_chk() upper level protocol header; * dyn_info - info about matched state to return back; * Returns pointer to state's parent rule and dyn_info. If there is * no state, NULL is returned. * On match ipfw_dyn_lookup() updates state's counters. */ struct ip_fw * ipfw_dyn_lookup_state(const struct ip_fw_args *args, const void *ulp, int pktlen, const ipfw_insn *cmd, struct ipfw_dyn_info *info) { struct dyn_data *data; struct ip_fw *rule; IPFW_RLOCK_ASSERT(&V_layer3_chain); MPASS(F_LEN(cmd) >= F_INSN_SIZE(ipfw_insn_kidx)); data = NULL; rule = NULL; info->kidx = insntoc(cmd, kidx)->kidx; info->direction = MATCH_NONE; info->hashval = hash_packet(&args->f_id); DYNSTATE_CRITICAL_ENTER(); if (IS_IP4_FLOW_ID(&args->f_id)) { struct dyn_ipv4_state *s; s = dyn_lookup_ipv4_state(&args->f_id, ulp, info, pktlen); if (s != NULL) { /* * Dynamic states are created using the same 5-tuple, * so it is assumed, that parent rule for O_LIMIT * state has the same address family. */ data = s->data; if (s->type == O_LIMIT) { s = data->parent; rule = s->limit->parent; } else rule = data->parent; } } #ifdef INET6 else if (IS_IP6_FLOW_ID(&args->f_id)) { struct dyn_ipv6_state *s; s = dyn_lookup_ipv6_state(&args->f_id, dyn_getscopeid(args), ulp, info, pktlen); if (s != NULL) { data = s->data; if (s->type == O_LIMIT) { s = data->parent; rule = s->limit->parent; } else rule = data->parent; } } #endif if (data != NULL) { /* * If cached chain id is the same, we can avoid rule index * lookup. Otherwise do lookup and update chain_id and f_pos. * It is safe even if there is concurrent thread that want * update the same state, because chain->id can be changed * only under IPFW_WLOCK(). */ if (data->chain_id != V_layer3_chain.id) { data->f_pos = ipfw_find_rule(&V_layer3_chain, data->rulenum, data->ruleid); /* * Check that found state has not orphaned. * When chain->id being changed the parent * rule can be deleted. If found rule doesn't * match the parent pointer, consider this * result as MATCH_NONE and return NULL. * * This will lead to creation of new similar state * that will be added into head of this bucket. * And the state that we currently have matched * should be deleted by dyn_expire_states(). * * In case when dyn_keep_states is enabled, return * pointer to deleted rule and f_pos value * corresponding to penultimate rule. * When we have enabled V_dyn_keep_states, states * that become orphaned will get the DYN_REFERENCED * flag and rule will keep around. So we can return * it. But since it is not in the rules map, we need * return such f_pos value, so after the state * handling if the search will continue, the next rule * will be the last one - the default rule. */ if (V_layer3_chain.map[data->f_pos] == rule) { data->chain_id = V_layer3_chain.id; } else if (V_dyn_keep_states != 0) { /* * The original rule pointer is still usable. * So, we return it, but f_pos need to be * changed to point to the penultimate rule. */ MPASS(V_layer3_chain.n_rules > 1); if (dyn_handle_orphaned(rule, data) == 0) { data->chain_id = V_layer3_chain.id; data->f_pos = V_layer3_chain.n_rules - 2; } else { rule = NULL; info->direction = MATCH_NONE; } } else { rule = NULL; info->direction = MATCH_NONE; DYN_DEBUG("rule %p [%u, %u] is considered " "invalid in data %p", rule, data->ruleid, data->rulenum, data); /* info->f_pos doesn't matter here. */ } } info->f_pos = data->f_pos; } DYNSTATE_CRITICAL_EXIT(); #if 0 /* * Return MATCH_NONE if parent rule is in disabled set. * This will lead to creation of new similar state that * will be added into head of this bucket. * * XXXAE: we need to be able update state's set when parent * rule set is changed. */ if (rule != NULL && (V_set_disable & (1 << rule->set))) { rule = NULL; info->direction = MATCH_NONE; } #endif return (rule); } static struct dyn_parent * dyn_alloc_parent(void *parent, uint32_t ruleid, uint32_t rulenum, uint32_t hashval) { struct dyn_parent *limit; limit = uma_zalloc(V_dyn_parent_zone, M_NOWAIT | M_ZERO); if (limit == NULL) { if (last_log != time_uptime) { last_log = time_uptime; log(LOG_DEBUG, "ipfw: Cannot allocate parent dynamic state, " "consider increasing " "net.inet.ip.fw.dyn_parent_max\n"); } return (NULL); } limit->parent = parent; limit->ruleid = ruleid; limit->rulenum = rulenum; limit->hashval = hashval; limit->expire = time_uptime + V_dyn_short_lifetime; return (limit); } static struct dyn_data * dyn_alloc_dyndata(void *parent, uint32_t ruleid, uint32_t rulenum, const struct ipfw_flow_id *pkt, const void *ulp, int pktlen, uint32_t hashval, uint16_t fibnum) { struct dyn_data *data; data = uma_zalloc(V_dyn_data_zone, M_NOWAIT | M_ZERO); if (data == NULL) { if (last_log != time_uptime) { last_log = time_uptime; log(LOG_DEBUG, "ipfw: Cannot allocate dynamic state, " "consider increasing net.inet.ip.fw.dyn_max\n"); } return (NULL); } data->parent = parent; data->ruleid = ruleid; data->rulenum = rulenum; data->fibnum = fibnum; data->hashval = hashval; data->expire = time_uptime + V_dyn_syn_lifetime; dyn_update_proto_state(data, pkt, ulp, pktlen, MATCH_FORWARD); return (data); } static struct dyn_ipv4_state * dyn_alloc_ipv4_state(const struct ipfw_flow_id *pkt, uint32_t kidx, uint8_t type) { struct dyn_ipv4_state *s; s = uma_zalloc(V_dyn_ipv4_zone, M_NOWAIT | M_ZERO); if (s == NULL) return (NULL); s->type = type; s->kidx = kidx; s->proto = pkt->proto; s->sport = pkt->src_port; s->dport = pkt->dst_port; s->src = pkt->src_ip; s->dst = pkt->dst_ip; return (s); } /* * Add IPv4 parent state. * Returns pointer to parent state. When it is not NULL we are in * critical section and pointer protected by hazard pointer. * When some error occurs, it returns NULL and exit from critical section * is not needed. */ static struct dyn_ipv4_state * dyn_add_ipv4_parent(void *rule, uint32_t ruleid, uint32_t rulenum, const struct ipfw_flow_id *pkt, uint32_t hashval, uint32_t version, uint32_t kidx) { struct dyn_ipv4_state *s; struct dyn_parent *limit; uint32_t bucket; bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); DYN_BUCKET_LOCK(bucket); if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_add)) { /* * Bucket version has been changed since last lookup, * do lookup again to be sure that state does not exist. */ s = dyn_lookup_ipv4_parent_locked(pkt, rule, ruleid, rulenum, bucket); if (s != NULL) { /* * Simultaneous thread has already created this * state. Just return it. */ DYNSTATE_CRITICAL_ENTER(); DYNSTATE_PROTECT(s); DYN_BUCKET_UNLOCK(bucket); return (s); } } limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval); if (limit == NULL) { DYN_BUCKET_UNLOCK(bucket); return (NULL); } s = dyn_alloc_ipv4_state(pkt, kidx, O_LIMIT_PARENT); if (s == NULL) { DYN_BUCKET_UNLOCK(bucket); uma_zfree(V_dyn_parent_zone, limit); return (NULL); } s->limit = limit; CK_SLIST_INSERT_HEAD(&V_dyn_ipv4_parent[bucket], s, entry); DYN_COUNT_INC(dyn_parent_count); DYN_BUCKET_VERSION_BUMP(bucket, ipv4_parent_add); DYNSTATE_CRITICAL_ENTER(); DYNSTATE_PROTECT(s); DYN_BUCKET_UNLOCK(bucket); return (s); } static int dyn_add_ipv4_state(void *parent, uint32_t ruleid, uint32_t rulenum, const struct ipfw_flow_id *pkt, const void *ulp, int pktlen, uint32_t hashval, struct ipfw_dyn_info *info, uint16_t fibnum, uint32_t kidx, uint8_t type) { struct dyn_ipv4_state *s; void *data; uint32_t bucket; bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); DYN_BUCKET_LOCK(bucket); if (info->direction == MATCH_UNKNOWN || info->kidx != kidx || info->hashval != hashval || info->version != DYN_BUCKET_VERSION(bucket, ipv4_add)) { /* * Bucket version has been changed since last lookup, * do lookup again to be sure that state does not exist. */ if (dyn_lookup_ipv4_state_locked(pkt, ulp, pktlen, bucket, kidx) != 0) { DYN_BUCKET_UNLOCK(bucket); return (EEXIST); } } data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp, pktlen, hashval, fibnum); if (data == NULL) { DYN_BUCKET_UNLOCK(bucket); return (ENOMEM); } s = dyn_alloc_ipv4_state(pkt, kidx, type); if (s == NULL) { DYN_BUCKET_UNLOCK(bucket); uma_zfree(V_dyn_data_zone, data); return (ENOMEM); } s->data = data; CK_SLIST_INSERT_HEAD(&V_dyn_ipv4[bucket], s, entry); DYN_COUNT_INC(dyn_count); DYN_BUCKET_VERSION_BUMP(bucket, ipv4_add); DYN_BUCKET_UNLOCK(bucket); return (0); } #ifdef INET6 static struct dyn_ipv6_state * dyn_alloc_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid, uint32_t kidx, uint8_t type) { struct dyn_ipv6_state *s; s = uma_zalloc(V_dyn_ipv6_zone, M_NOWAIT | M_ZERO); if (s == NULL) return (NULL); s->type = type; s->kidx = kidx; s->zoneid = zoneid; s->proto = pkt->proto; s->sport = pkt->src_port; s->dport = pkt->dst_port; s->src = pkt->src_ip6; s->dst = pkt->dst_ip6; return (s); } /* * Add IPv6 parent state. * Returns pointer to parent state. When it is not NULL we are in * critical section and pointer protected by hazard pointer. * When some error occurs, it return NULL and exit from critical section * is not needed. */ static struct dyn_ipv6_state * dyn_add_ipv6_parent(void *rule, uint32_t ruleid, uint32_t rulenum, const struct ipfw_flow_id *pkt, uint32_t zoneid, uint32_t hashval, uint32_t version, uint32_t kidx) { struct dyn_ipv6_state *s; struct dyn_parent *limit; uint32_t bucket; bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); DYN_BUCKET_LOCK(bucket); if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_add)) { /* * Bucket version has been changed since last lookup, * do lookup again to be sure that state does not exist. */ s = dyn_lookup_ipv6_parent_locked(pkt, zoneid, rule, ruleid, rulenum, bucket); if (s != NULL) { /* * Simultaneous thread has already created this * state. Just return it. */ DYNSTATE_CRITICAL_ENTER(); DYNSTATE_PROTECT(s); DYN_BUCKET_UNLOCK(bucket); return (s); } } limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval); if (limit == NULL) { DYN_BUCKET_UNLOCK(bucket); return (NULL); } s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, O_LIMIT_PARENT); if (s == NULL) { DYN_BUCKET_UNLOCK(bucket); uma_zfree(V_dyn_parent_zone, limit); return (NULL); } s->limit = limit; CK_SLIST_INSERT_HEAD(&V_dyn_ipv6_parent[bucket], s, entry); DYN_COUNT_INC(dyn_parent_count); DYN_BUCKET_VERSION_BUMP(bucket, ipv6_parent_add); DYNSTATE_CRITICAL_ENTER(); DYNSTATE_PROTECT(s); DYN_BUCKET_UNLOCK(bucket); return (s); } static int dyn_add_ipv6_state(void *parent, uint32_t ruleid, uint32_t rulenum, const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *ulp, int pktlen, uint32_t hashval, struct ipfw_dyn_info *info, uint16_t fibnum, uint32_t kidx, uint8_t type) { struct dyn_ipv6_state *s; struct dyn_data *data; uint32_t bucket; bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); DYN_BUCKET_LOCK(bucket); if (info->direction == MATCH_UNKNOWN || info->kidx != kidx || info->hashval != hashval || info->version != DYN_BUCKET_VERSION(bucket, ipv6_add)) { /* * Bucket version has been changed since last lookup, * do lookup again to be sure that state does not exist. */ if (dyn_lookup_ipv6_state_locked(pkt, zoneid, ulp, pktlen, bucket, kidx) != 0) { DYN_BUCKET_UNLOCK(bucket); return (EEXIST); } } data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp, pktlen, hashval, fibnum); if (data == NULL) { DYN_BUCKET_UNLOCK(bucket); return (ENOMEM); } s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, type); if (s == NULL) { DYN_BUCKET_UNLOCK(bucket); uma_zfree(V_dyn_data_zone, data); return (ENOMEM); } s->data = data; CK_SLIST_INSERT_HEAD(&V_dyn_ipv6[bucket], s, entry); DYN_COUNT_INC(dyn_count); DYN_BUCKET_VERSION_BUMP(bucket, ipv6_add); DYN_BUCKET_UNLOCK(bucket); return (0); } #endif /* INET6 */ static void * dyn_get_parent_state(const struct ipfw_flow_id *pkt, uint32_t zoneid, struct ip_fw *rule, uint32_t hashval, uint32_t limit, uint32_t kidx) { char sbuf[24]; struct dyn_parent *p; void *ret; uint32_t bucket, version; p = NULL; ret = NULL; bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets); DYNSTATE_CRITICAL_ENTER(); if (IS_IP4_FLOW_ID(pkt)) { struct dyn_ipv4_state *s; version = DYN_BUCKET_VERSION(bucket, ipv4_parent_add); s = dyn_lookup_ipv4_parent(pkt, rule, rule->id, rule->rulenum, bucket); if (s == NULL) { /* * Exit from critical section because dyn_add_parent() * will acquire bucket lock. */ DYNSTATE_CRITICAL_EXIT(); s = dyn_add_ipv4_parent(rule, rule->id, rule->rulenum, pkt, hashval, version, kidx); if (s == NULL) return (NULL); /* Now we are in critical section again. */ } ret = s; p = s->limit; } #ifdef INET6 else if (IS_IP6_FLOW_ID(pkt)) { struct dyn_ipv6_state *s; version = DYN_BUCKET_VERSION(bucket, ipv6_parent_add); s = dyn_lookup_ipv6_parent(pkt, zoneid, rule, rule->id, rule->rulenum, bucket); if (s == NULL) { /* * Exit from critical section because dyn_add_parent() * can acquire bucket mutex. */ DYNSTATE_CRITICAL_EXIT(); s = dyn_add_ipv6_parent(rule, rule->id, rule->rulenum, pkt, zoneid, hashval, version, kidx); if (s == NULL) return (NULL); /* Now we are in critical section again. */ } ret = s; p = s->limit; } #endif else { DYNSTATE_CRITICAL_EXIT(); return (NULL); } /* Check the limit */ if (DPARENT_COUNT(p) >= limit) { DYNSTATE_CRITICAL_EXIT(); if (V_fw_verbose && last_log != time_uptime) { last_log = time_uptime; snprintf(sbuf, sizeof(sbuf), "%u drop session", rule->rulenum); print_dyn_rule_flags(pkt, O_LIMIT, LOG_SECURITY | LOG_DEBUG, sbuf, "too many entries"); } return (NULL); } /* Take new session into account. */ DPARENT_COUNT_INC(p); /* * We must exit from critical section because the following code * can acquire bucket mutex. * We rely on the 'count' field. The state will not expire * until it has some child states, i.e. 'count' field is not zero. * Return state pointer, it will be used by child states as parent. */ DYNSTATE_CRITICAL_EXIT(); return (ret); } static int dyn_install_state(const struct ipfw_flow_id *pkt, uint32_t zoneid, uint16_t fibnum, const void *ulp, int pktlen, struct ip_fw *rule, struct ipfw_dyn_info *info, uint32_t limit, uint16_t limit_mask, uint32_t kidx, uint8_t type) { struct ipfw_flow_id id; uint32_t hashval, parent_hashval, ruleid, rulenum; int ret; MPASS(type == O_LIMIT || type == O_KEEP_STATE); ruleid = rule->id; rulenum = rule->rulenum; if (type == O_LIMIT) { /* Create masked flow id and calculate bucket */ id.addr_type = pkt->addr_type; id.proto = pkt->proto; id.fib = fibnum; /* unused */ id.src_port = (limit_mask & DYN_SRC_PORT) ? pkt->src_port: 0; id.dst_port = (limit_mask & DYN_DST_PORT) ? pkt->dst_port: 0; if (IS_IP4_FLOW_ID(pkt)) { id.src_ip = (limit_mask & DYN_SRC_ADDR) ? pkt->src_ip: 0; id.dst_ip = (limit_mask & DYN_DST_ADDR) ? pkt->dst_ip: 0; } #ifdef INET6 else if (IS_IP6_FLOW_ID(pkt)) { if (limit_mask & DYN_SRC_ADDR) id.src_ip6 = pkt->src_ip6; else memset(&id.src_ip6, 0, sizeof(id.src_ip6)); if (limit_mask & DYN_DST_ADDR) id.dst_ip6 = pkt->dst_ip6; else memset(&id.dst_ip6, 0, sizeof(id.dst_ip6)); } #endif else return (EAFNOSUPPORT); parent_hashval = hash_parent(&id, rule); rule = dyn_get_parent_state(&id, zoneid, rule, parent_hashval, limit, kidx); if (rule == NULL) { #if 0 if (V_fw_verbose && last_log != time_uptime) { last_log = time_uptime; snprintf(sbuf, sizeof(sbuf), "%u drop session", rule->rulenum); print_dyn_rule_flags(pkt, O_LIMIT, LOG_SECURITY | LOG_DEBUG, sbuf, "too many entries"); } #endif return (EACCES); } /* * Limit is not reached, create new state. * Now rule points to parent state. */ } hashval = hash_packet(pkt); if (IS_IP4_FLOW_ID(pkt)) ret = dyn_add_ipv4_state(rule, ruleid, rulenum, pkt, ulp, pktlen, hashval, info, fibnum, kidx, type); #ifdef INET6 else if (IS_IP6_FLOW_ID(pkt)) ret = dyn_add_ipv6_state(rule, ruleid, rulenum, pkt, zoneid, ulp, pktlen, hashval, info, fibnum, kidx, type); #endif /* INET6 */ else ret = EAFNOSUPPORT; if (type == O_LIMIT) { if (ret != 0) { /* * We failed to create child state for O_LIMIT * opcode. Since we already counted it in the parent, * we must revert counter back. The 'rule' points to * parent state, use it to get dyn_parent. * * XXXAE: it should be safe to use 'rule' pointer * without extra lookup, parent state is referenced * and should not be freed. */ if (IS_IP4_FLOW_ID(&id)) DPARENT_COUNT_DEC( ((struct dyn_ipv4_state *)rule)->limit); #ifdef INET6 else if (IS_IP6_FLOW_ID(&id)) DPARENT_COUNT_DEC( ((struct dyn_ipv6_state *)rule)->limit); #endif } } /* * EEXIST means that simultaneous thread has created this * state. Consider this as success. * * XXXAE: should we invalidate 'info' content here? */ if (ret == EEXIST) return (0); return (ret); } /* * Install dynamic state. * chain - ipfw's instance; * rule - the parent rule that installs the state; * cmd - opcode that installs the state; * args - ipfw arguments; * ulp - upper level protocol header; * pktlen - packet length; * info - dynamic state lookup info; * tablearg - tablearg id. * * Returns non-zero value (failure) if state is not installed because * of errors or because session limitations are enforced. */ int ipfw_dyn_install_state(struct ip_fw_chain *chain, struct ip_fw *rule, const ipfw_insn_limit *cmd, const struct ip_fw_args *args, const void *ulp, int pktlen, struct ipfw_dyn_info *info, uint32_t tablearg) { uint32_t limit; uint16_t limit_mask; if (cmd->o.opcode == O_LIMIT) { limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit); limit_mask = cmd->limit_mask; } else { limit = 0; limit_mask = 0; } /* * NOTE: we assume that kidx field of struct ipfw_insn_kidx * located in the same place as kidx field of ipfw_insn_limit. */ return (dyn_install_state(&args->f_id, #ifdef INET6 IS_IP6_FLOW_ID(&args->f_id) ? dyn_getscopeid(args): #endif 0, M_GETFIB(args->m), ulp, pktlen, rule, info, limit, limit_mask, cmd->kidx, cmd->o.opcode)); } /* * Free safe to remove state entries from expired lists. */ static void dyn_free_states(struct ip_fw_chain *chain) { struct dyn_ipv4_state *s4, *s4n; #ifdef INET6 struct dyn_ipv6_state *s6, *s6n; #endif int cached_count, i; /* * We keep pointers to objects that are in use on each CPU * in the per-cpu dyn_hp pointer. When object is going to be * removed, first of it is unlinked from the corresponding * list. This leads to changing of dyn_bucket_xxx_delver version. * Unlinked objects is placed into corresponding dyn_expired_xxx * list. Reader that is going to dereference object pointer checks * dyn_bucket_xxx_delver version before and after storing pointer * into dyn_hp. If version is the same, the object is protected * from freeing and it is safe to dereference. Othervise reader * tries to iterate list again from the beginning, but this object * now unlinked and thus will not be accessible. * * Copy dyn_hp pointers for each CPU into dyn_hp_cache array. * It does not matter that some pointer can be changed in * time while we are copying. We need to check, that objects * removed in the previous pass are not in use. And if dyn_hp * pointer does not contain it in the time when we are copying, * it will not appear there, because it is already unlinked. * And for new pointers we will not free objects that will be * unlinked in this pass. */ cached_count = 0; CPU_FOREACH(i) { dyn_hp_cache[cached_count] = DYNSTATE_GET(i); if (dyn_hp_cache[cached_count] != NULL) cached_count++; } /* * Free expired states that are safe to free. * Check each entry from previous pass in the dyn_expired_xxx * list, if pointer to the object is in the dyn_hp_cache array, * keep it until next pass. Otherwise it is safe to free the * object. * * XXXAE: optimize this to use SLIST_REMOVE_AFTER. */ #define DYN_FREE_STATES(s, next, name) do { \ s = SLIST_FIRST(&V_dyn_expired_ ## name); \ while (s != NULL) { \ next = SLIST_NEXT(s, expired); \ for (i = 0; i < cached_count; i++) \ if (dyn_hp_cache[i] == s) \ break; \ if (i == cached_count) { \ if (s->type == O_LIMIT_PARENT && \ s->limit->count != 0) { \ s = next; \ continue; \ } \ SLIST_REMOVE(&V_dyn_expired_ ## name, \ s, dyn_ ## name ## _state, expired); \ if (s->type == O_LIMIT_PARENT) \ uma_zfree(V_dyn_parent_zone, s->limit); \ else \ uma_zfree(V_dyn_data_zone, s->data); \ uma_zfree(V_dyn_ ## name ## _zone, s); \ } \ s = next; \ } \ } while (0) /* * Protect access to expired lists with DYN_EXPIRED_LOCK. * Userland can invoke ipfw_expire_dyn_states() to delete * specific states, this will lead to modification of expired * lists. * * XXXAE: do we need DYN_EXPIRED_LOCK? We can just use * IPFW_UH_WLOCK to protect access to these lists. */ DYN_EXPIRED_LOCK(); DYN_FREE_STATES(s4, s4n, ipv4); #ifdef INET6 DYN_FREE_STATES(s6, s6n, ipv6); #endif DYN_EXPIRED_UNLOCK(); #undef DYN_FREE_STATES } /* * Returns: * 0 when state is not matched by specified range; * 1 when state is matched by specified range; * 2 when state is matched by specified range and requested deletion of * dynamic states. */ static int dyn_match_range(uint32_t rulenum, uint8_t set, const ipfw_range_tlv *rt) { MPASS(rt != NULL); /* flush all states */ if (rt->flags & IPFW_RCFLAG_ALL) { if (rt->flags & IPFW_RCFLAG_DYNAMIC) return (2); /* forced */ return (1); } if ((rt->flags & IPFW_RCFLAG_SET) != 0 && set != rt->set) return (0); if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 && (rulenum < rt->start_rule || rulenum > rt->end_rule)) return (0); if (rt->flags & IPFW_RCFLAG_DYNAMIC) return (2); return (1); } static void dyn_acquire_rule(struct ip_fw_chain *ch, struct dyn_data *data, struct ip_fw *rule, uint32_t kidx) { struct dyn_state_obj *obj; /* * Do not acquire reference twice. * This can happen when rule deletion executed for * the same range, but different ruleset id. */ if (data->flags & DYN_REFERENCED) return; IPFW_UH_WLOCK_ASSERT(ch); MPASS(kidx != 0); data->flags |= DYN_REFERENCED; /* Reference the named object */ obj = SRV_OBJECT(ch, kidx); obj->no.refcnt++; MPASS(obj->no.etlv == IPFW_TLV_STATE_NAME); /* Reference the parent rule */ rule->refcnt++; } static void dyn_release_rule(struct ip_fw_chain *ch, struct dyn_data *data, struct ip_fw *rule, uint32_t kidx) { struct dyn_state_obj *obj; IPFW_UH_WLOCK_ASSERT(ch); MPASS(kidx != 0); obj = SRV_OBJECT(ch, kidx); if (obj->no.refcnt == 1) dyn_destroy(ch, &obj->no); else obj->no.refcnt--; if (--rule->refcnt == 1) ipfw_free_rule(rule); } /* * We do not keep O_LIMIT_PARENT states when V_dyn_keep_states is enabled. * O_LIMIT state is created when new connection is going to be established * and there is no matching state. So, since the old parent rule was deleted * we can't create new states with old parent, and thus we can not account * new connections with already established connections, and can not do * proper limiting. */ static int dyn_match_ipv4_state(struct ip_fw_chain *ch, struct dyn_ipv4_state *s, const ipfw_range_tlv *rt) { struct ip_fw *rule; int ret; if (s->type == O_LIMIT_PARENT) { rule = s->limit->parent; return (dyn_match_range(s->limit->rulenum, rule->set, rt)); } rule = s->data->parent; if (s->type == O_LIMIT) rule = ((struct dyn_ipv4_state *)rule)->limit->parent; ret = dyn_match_range(s->data->rulenum, rule->set, rt); if (ret == 0 || V_dyn_keep_states == 0 || ret > 1) return (ret); dyn_acquire_rule(ch, s->data, rule, s->kidx); return (0); } #ifdef INET6 static int dyn_match_ipv6_state(struct ip_fw_chain *ch, struct dyn_ipv6_state *s, const ipfw_range_tlv *rt) { struct ip_fw *rule; int ret; if (s->type == O_LIMIT_PARENT) { rule = s->limit->parent; return (dyn_match_range(s->limit->rulenum, rule->set, rt)); } rule = s->data->parent; if (s->type == O_LIMIT) rule = ((struct dyn_ipv6_state *)rule)->limit->parent; ret = dyn_match_range(s->data->rulenum, rule->set, rt); if (ret == 0 || V_dyn_keep_states == 0 || ret > 1) return (ret); dyn_acquire_rule(ch, s->data, rule, s->kidx); return (0); } #endif /* * Unlink expired entries from states lists. * @rt can be used to specify the range of states for deletion. */ static void dyn_expire_states(struct ip_fw_chain *ch, ipfw_range_tlv *rt) { struct dyn_ipv4_slist expired_ipv4; #ifdef INET6 struct dyn_ipv6_slist expired_ipv6; struct dyn_ipv6_state *s6, *s6n, *s6p; #endif struct dyn_ipv4_state *s4, *s4n, *s4p; void *rule; int bucket, removed, length, max_length; IPFW_UH_WLOCK_ASSERT(ch); /* * Unlink expired states from each bucket. * With acquired bucket lock iterate entries of each lists: * ipv4, ipv4_parent, ipv6, and ipv6_parent. Check expired time * and unlink entry from the list, link entry into temporary * expired_xxx lists then bump "del" bucket version. * * When an entry is removed, corresponding states counter is * decremented. If entry has O_LIMIT type, parent's reference * counter is decremented. * * NOTE: this function can be called from userspace context * when user deletes rules. In this case all matched states * will be forcedly unlinked. O_LIMIT_PARENT states will be kept * in the expired lists until reference counter become zero. */ #define DYN_UNLINK_STATES(s, prev, next, exp, af, name, extra) do { \ length = 0; \ removed = 0; \ prev = NULL; \ s = CK_SLIST_FIRST(&V_dyn_ ## name [bucket]); \ while (s != NULL) { \ next = CK_SLIST_NEXT(s, entry); \ if ((TIME_LEQ((s)->exp, time_uptime) && extra) || \ (rt != NULL && \ dyn_match_ ## af ## _state(ch, s, rt))) { \ if (prev != NULL) \ CK_SLIST_REMOVE_AFTER(prev, entry); \ else \ CK_SLIST_REMOVE_HEAD( \ &V_dyn_ ## name [bucket], entry); \ removed++; \ SLIST_INSERT_HEAD(&expired_ ## af, s, expired); \ if (s->type == O_LIMIT_PARENT) \ DYN_COUNT_DEC(dyn_parent_count); \ else { \ DYN_COUNT_DEC(dyn_count); \ if (s->data->flags & DYN_REFERENCED) { \ rule = s->data->parent; \ if (s->type == O_LIMIT) \ rule = ((__typeof(s)) \ rule)->limit->parent;\ dyn_release_rule(ch, s->data, \ rule, s->kidx); \ } \ if (s->type == O_LIMIT) { \ s = s->data->parent; \ DPARENT_COUNT_DEC(s->limit); \ } \ } \ } else { \ prev = s; \ length++; \ } \ s = next; \ } \ if (removed != 0) \ DYN_BUCKET_VERSION_BUMP(bucket, name ## _del); \ if (length > max_length) \ max_length = length; \ } while (0) SLIST_INIT(&expired_ipv4); #ifdef INET6 SLIST_INIT(&expired_ipv6); #endif max_length = 0; for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { DYN_BUCKET_LOCK(bucket); DYN_UNLINK_STATES(s4, s4p, s4n, data->expire, ipv4, ipv4, 1); DYN_UNLINK_STATES(s4, s4p, s4n, limit->expire, ipv4, ipv4_parent, (s4->limit->count == 0)); #ifdef INET6 DYN_UNLINK_STATES(s6, s6p, s6n, data->expire, ipv6, ipv6, 1); DYN_UNLINK_STATES(s6, s6p, s6n, limit->expire, ipv6, ipv6_parent, (s6->limit->count == 0)); #endif DYN_BUCKET_UNLOCK(bucket); } /* Update curr_max_length for statistics. */ V_curr_max_length = max_length; /* * Concatenate temporary lists with global expired lists. */ DYN_EXPIRED_LOCK(); SLIST_CONCAT(&V_dyn_expired_ipv4, &expired_ipv4, dyn_ipv4_state, expired); #ifdef INET6 SLIST_CONCAT(&V_dyn_expired_ipv6, &expired_ipv6, dyn_ipv6_state, expired); #endif DYN_EXPIRED_UNLOCK(); #undef DYN_UNLINK_STATES #undef DYN_UNREF_STATES } static struct mbuf * dyn_mgethdr(int len, uint16_t fibnum) { struct mbuf *m; m = m_gethdr(M_NOWAIT, MT_DATA); if (m == NULL) return (NULL); #ifdef MAC mac_netinet_firewall_send(m); #endif M_SETFIB(m, fibnum); m->m_data += max_linkhdr; m->m_flags |= M_SKIP_FIREWALL; m->m_len = m->m_pkthdr.len = len; bzero(m->m_data, len); return (m); } static void dyn_make_keepalive_ipv4(struct mbuf *m, in_addr_t src, in_addr_t dst, uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport) { struct tcphdr *tcp; struct ip *ip; ip = mtod(m, struct ip *); ip->ip_v = 4; ip->ip_hl = sizeof(*ip) >> 2; ip->ip_tos = IPTOS_LOWDELAY; ip->ip_len = htons(m->m_len); ip->ip_off |= htons(IP_DF); ip->ip_ttl = V_ip_defttl; ip->ip_p = IPPROTO_TCP; ip->ip_src.s_addr = htonl(src); ip->ip_dst.s_addr = htonl(dst); tcp = mtodo(m, sizeof(struct ip)); tcp->th_sport = htons(sport); tcp->th_dport = htons(dport); tcp->th_off = sizeof(struct tcphdr) >> 2; tcp->th_seq = htonl(seq); tcp->th_ack = htonl(ack); tcp_set_flags(tcp, TH_ACK); tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, htons(sizeof(struct tcphdr) + IPPROTO_TCP)); m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); m->m_pkthdr.csum_flags = CSUM_TCP; } static void dyn_enqueue_keepalive_ipv4(struct mbufq *q, const struct dyn_ipv4_state *s) { struct mbuf *m; if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) { m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr), s->data->fibnum); if (m != NULL) { dyn_make_keepalive_ipv4(m, s->dst, s->src, s->data->ack_fwd - 1, s->data->ack_rev, s->dport, s->sport); if (mbufq_enqueue(q, m)) { m_freem(m); log(LOG_DEBUG, "ipfw: limit for IPv4 " "keepalive queue is reached.\n"); return; } } } if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) { m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr), s->data->fibnum); if (m != NULL) { dyn_make_keepalive_ipv4(m, s->src, s->dst, s->data->ack_rev - 1, s->data->ack_fwd, s->sport, s->dport); if (mbufq_enqueue(q, m)) { m_freem(m); log(LOG_DEBUG, "ipfw: limit for IPv4 " "keepalive queue is reached.\n"); return; } } } } /* * Prepare and send keep-alive packets. */ static void dyn_send_keepalive_ipv4(struct ip_fw_chain *chain) { struct mbufq q; struct mbuf *m; struct dyn_ipv4_state *s; uint32_t bucket; mbufq_init(&q, INT_MAX); IPFW_UH_RLOCK(chain); /* * It is safe to not use hazard pointer and just do lockless * access to the lists, because states entries can not be deleted * while we hold IPFW_UH_RLOCK. */ for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) { /* * Only established TCP connections that will * become expired within dyn_keepalive_interval. */ if (s->proto != IPPROTO_TCP || (s->data->state & BOTH_SYN) != BOTH_SYN || TIME_LEQ(time_uptime + V_dyn_keepalive_interval, s->data->expire)) continue; dyn_enqueue_keepalive_ipv4(&q, s); } } IPFW_UH_RUNLOCK(chain); while ((m = mbufq_dequeue(&q)) != NULL) ip_output(m, NULL, NULL, 0, NULL, NULL); } #ifdef INET6 static void dyn_make_keepalive_ipv6(struct mbuf *m, const struct in6_addr *src, const struct in6_addr *dst, uint32_t zoneid, uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport) { struct tcphdr *tcp; struct ip6_hdr *ip6; ip6 = mtod(m, struct ip6_hdr *); ip6->ip6_vfc |= IPV6_VERSION; ip6->ip6_plen = htons(sizeof(struct tcphdr)); ip6->ip6_nxt = IPPROTO_TCP; ip6->ip6_hlim = IPV6_DEFHLIM; ip6->ip6_src = *src; if (IN6_IS_ADDR_LINKLOCAL(src)) ip6->ip6_src.s6_addr16[1] = htons(zoneid & 0xffff); ip6->ip6_dst = *dst; if (IN6_IS_ADDR_LINKLOCAL(dst)) ip6->ip6_dst.s6_addr16[1] = htons(zoneid & 0xffff); tcp = mtodo(m, sizeof(struct ip6_hdr)); tcp->th_sport = htons(sport); tcp->th_dport = htons(dport); tcp->th_off = sizeof(struct tcphdr) >> 2; tcp->th_seq = htonl(seq); tcp->th_ack = htonl(ack); tcp_set_flags(tcp, TH_ACK); tcp->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr), IPPROTO_TCP, 0); m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); m->m_pkthdr.csum_flags = CSUM_TCP_IPV6; } static void dyn_enqueue_keepalive_ipv6(struct mbufq *q, const struct dyn_ipv6_state *s) { struct mbuf *m; if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) { m = dyn_mgethdr(sizeof(struct ip6_hdr) + sizeof(struct tcphdr), s->data->fibnum); if (m != NULL) { dyn_make_keepalive_ipv6(m, &s->dst, &s->src, s->zoneid, s->data->ack_fwd - 1, s->data->ack_rev, s->dport, s->sport); if (mbufq_enqueue(q, m)) { m_freem(m); log(LOG_DEBUG, "ipfw: limit for IPv6 " "keepalive queue is reached.\n"); return; } } } if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) { m = dyn_mgethdr(sizeof(struct ip6_hdr) + sizeof(struct tcphdr), s->data->fibnum); if (m != NULL) { dyn_make_keepalive_ipv6(m, &s->src, &s->dst, s->zoneid, s->data->ack_rev - 1, s->data->ack_fwd, s->sport, s->dport); if (mbufq_enqueue(q, m)) { m_freem(m); log(LOG_DEBUG, "ipfw: limit for IPv6 " "keepalive queue is reached.\n"); return; } } } } static void dyn_send_keepalive_ipv6(struct ip_fw_chain *chain) { struct mbufq q; struct mbuf *m; struct dyn_ipv6_state *s; uint32_t bucket; mbufq_init(&q, INT_MAX); IPFW_UH_RLOCK(chain); /* * It is safe to not use hazard pointer and just do lockless * access to the lists, because states entries can not be deleted * while we hold IPFW_UH_RLOCK. */ for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) { /* * Only established TCP connections that will * become expired within dyn_keepalive_interval. */ if (s->proto != IPPROTO_TCP || (s->data->state & BOTH_SYN) != BOTH_SYN || TIME_LEQ(time_uptime + V_dyn_keepalive_interval, s->data->expire)) continue; dyn_enqueue_keepalive_ipv6(&q, s); } } IPFW_UH_RUNLOCK(chain); while ((m = mbufq_dequeue(&q)) != NULL) ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL); } #endif /* INET6 */ static void dyn_grow_hashtable(struct ip_fw_chain *chain, uint32_t new, int flags) { #ifdef INET6 struct dyn_ipv6ck_slist *ipv6, *ipv6_parent; uint32_t *ipv6_add, *ipv6_del, *ipv6_parent_add, *ipv6_parent_del; struct dyn_ipv6_state *s6; #endif struct dyn_ipv4ck_slist *ipv4, *ipv4_parent; uint32_t *ipv4_add, *ipv4_del, *ipv4_parent_add, *ipv4_parent_del; struct dyn_ipv4_state *s4; struct mtx *bucket_lock; void *tmp; uint32_t bucket; MPASS(powerof2(new)); DYN_DEBUG("grow hash size %u -> %u", V_curr_dyn_buckets, new); /* * Allocate and initialize new lists. */ bucket_lock = malloc(new * sizeof(struct mtx), M_IPFW, flags | M_ZERO); if (bucket_lock == NULL) return; ipv4 = ipv4_parent = NULL; ipv4_add = ipv4_del = ipv4_parent_add = ipv4_parent_del = NULL; #ifdef INET6 ipv6 = ipv6_parent = NULL; ipv6_add = ipv6_del = ipv6_parent_add = ipv6_parent_del = NULL; #endif ipv4 = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW, flags | M_ZERO); if (ipv4 == NULL) goto bad; ipv4_parent = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW, flags | M_ZERO); if (ipv4_parent == NULL) goto bad; ipv4_add = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO); if (ipv4_add == NULL) goto bad; ipv4_del = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO); if (ipv4_del == NULL) goto bad; ipv4_parent_add = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO); if (ipv4_parent_add == NULL) goto bad; ipv4_parent_del = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO); if (ipv4_parent_del == NULL) goto bad; #ifdef INET6 ipv6 = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW, flags | M_ZERO); if (ipv6 == NULL) goto bad; ipv6_parent = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW, flags | M_ZERO); if (ipv6_parent == NULL) goto bad; ipv6_add = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO); if (ipv6_add == NULL) goto bad; ipv6_del = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO); if (ipv6_del == NULL) goto bad; ipv6_parent_add = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO); if (ipv6_parent_add == NULL) goto bad; ipv6_parent_del = malloc(new * sizeof(uint32_t), M_IPFW, flags | M_ZERO); if (ipv6_parent_del == NULL) goto bad; #endif for (bucket = 0; bucket < new; bucket++) { DYN_BUCKET_LOCK_INIT(bucket_lock, bucket); CK_SLIST_INIT(&ipv4[bucket]); CK_SLIST_INIT(&ipv4_parent[bucket]); #ifdef INET6 CK_SLIST_INIT(&ipv6[bucket]); CK_SLIST_INIT(&ipv6_parent[bucket]); #endif } #define DYN_RELINK_STATES(s, hval, i, head, ohead) do { \ while ((s = CK_SLIST_FIRST(&V_dyn_ ## ohead[i])) != NULL) { \ CK_SLIST_REMOVE_HEAD(&V_dyn_ ## ohead[i], entry); \ CK_SLIST_INSERT_HEAD(&head[DYN_BUCKET(s->hval, new)], \ s, entry); \ } \ } while (0) /* * Prevent rules changing from userland. */ IPFW_UH_WLOCK(chain); /* * Hold traffic processing until we finish resize to * prevent access to states lists. */ IPFW_WLOCK(chain); /* Re-link all dynamic states */ for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { DYN_RELINK_STATES(s4, data->hashval, bucket, ipv4, ipv4); DYN_RELINK_STATES(s4, limit->hashval, bucket, ipv4_parent, ipv4_parent); #ifdef INET6 DYN_RELINK_STATES(s6, data->hashval, bucket, ipv6, ipv6); DYN_RELINK_STATES(s6, limit->hashval, bucket, ipv6_parent, ipv6_parent); #endif } #define DYN_SWAP_PTR(old, new, tmp) do { \ tmp = old; \ old = new; \ new = tmp; \ } while (0) /* Swap pointers */ DYN_SWAP_PTR(V_dyn_bucket_lock, bucket_lock, tmp); DYN_SWAP_PTR(V_dyn_ipv4, ipv4, tmp); DYN_SWAP_PTR(V_dyn_ipv4_parent, ipv4_parent, tmp); DYN_SWAP_PTR(V_dyn_ipv4_add, ipv4_add, tmp); DYN_SWAP_PTR(V_dyn_ipv4_parent_add, ipv4_parent_add, tmp); DYN_SWAP_PTR(V_dyn_ipv4_del, ipv4_del, tmp); DYN_SWAP_PTR(V_dyn_ipv4_parent_del, ipv4_parent_del, tmp); #ifdef INET6 DYN_SWAP_PTR(V_dyn_ipv6, ipv6, tmp); DYN_SWAP_PTR(V_dyn_ipv6_parent, ipv6_parent, tmp); DYN_SWAP_PTR(V_dyn_ipv6_add, ipv6_add, tmp); DYN_SWAP_PTR(V_dyn_ipv6_parent_add, ipv6_parent_add, tmp); DYN_SWAP_PTR(V_dyn_ipv6_del, ipv6_del, tmp); DYN_SWAP_PTR(V_dyn_ipv6_parent_del, ipv6_parent_del, tmp); #endif bucket = V_curr_dyn_buckets; V_curr_dyn_buckets = new; IPFW_WUNLOCK(chain); IPFW_UH_WUNLOCK(chain); /* Release old resources */ while (bucket-- != 0) DYN_BUCKET_LOCK_DESTROY(bucket_lock, bucket); bad: free(bucket_lock, M_IPFW); free(ipv4, M_IPFW); free(ipv4_parent, M_IPFW); free(ipv4_add, M_IPFW); free(ipv4_parent_add, M_IPFW); free(ipv4_del, M_IPFW); free(ipv4_parent_del, M_IPFW); #ifdef INET6 free(ipv6, M_IPFW); free(ipv6_parent, M_IPFW); free(ipv6_add, M_IPFW); free(ipv6_parent_add, M_IPFW); free(ipv6_del, M_IPFW); free(ipv6_parent_del, M_IPFW); #endif } /* * This function is used to perform various maintenance * on dynamic hash lists. Currently it is called every second. */ static void dyn_tick(void *vnetx) { struct epoch_tracker et; uint32_t buckets; CURVNET_SET((struct vnet *)vnetx); /* * First free states unlinked in previous passes. */ dyn_free_states(&V_layer3_chain); /* * Now unlink others expired states. * We use IPFW_UH_WLOCK to avoid concurrent call of * dyn_expire_states(). It is the only function that does * deletion of state entries from states lists. */ IPFW_UH_WLOCK(&V_layer3_chain); dyn_expire_states(&V_layer3_chain, NULL); IPFW_UH_WUNLOCK(&V_layer3_chain); /* * Send keepalives if they are enabled and the time has come. */ if (V_dyn_keepalive != 0 && V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) { V_dyn_keepalive_last = time_uptime; NET_EPOCH_ENTER(et); dyn_send_keepalive_ipv4(&V_layer3_chain); #ifdef INET6 dyn_send_keepalive_ipv6(&V_layer3_chain); #endif NET_EPOCH_EXIT(et); } /* * Check if we need to resize the hash: * if current number of states exceeds number of buckets in hash, * and dyn_buckets_max permits to grow the number of buckets, then * do it. Grow hash size to the minimum power of 2 which is bigger * than current states count. */ if (V_curr_dyn_buckets < V_dyn_buckets_max && (V_curr_dyn_buckets < V_dyn_count / 2 || ( V_curr_dyn_buckets < V_dyn_count && V_curr_max_length > 8))) { buckets = 1 << fls(V_dyn_count); if (buckets > V_dyn_buckets_max) buckets = V_dyn_buckets_max; dyn_grow_hashtable(&V_layer3_chain, buckets, M_NOWAIT); } callout_reset_on(&V_dyn_timeout, hz, dyn_tick, vnetx, 0); CURVNET_RESTORE(); } void ipfw_expire_dyn_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt) { /* * Do not perform any checks if we currently have no dynamic states */ if (V_dyn_count == 0) return; IPFW_UH_WLOCK_ASSERT(chain); dyn_expire_states(chain, rt); } /* * Pass through all states and reset eaction for orphaned rules. */ void ipfw_dyn_reset_eaction(struct ip_fw_chain *ch, uint32_t eaction_id, uint32_t default_id, uint32_t instance_id) { #ifdef INET6 struct dyn_ipv6_state *s6; #endif struct dyn_ipv4_state *s4; struct ip_fw *rule; uint32_t bucket; #define DYN_RESET_EACTION(s, h, b) \ CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ if ((s->data->flags & DYN_REFERENCED) == 0) \ continue; \ rule = s->data->parent; \ if (s->type == O_LIMIT) \ rule = ((__typeof(s))rule)->limit->parent; \ ipfw_reset_eaction(ch, rule, eaction_id, \ default_id, instance_id); \ } IPFW_UH_WLOCK_ASSERT(ch); if (V_dyn_count == 0) return; for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { DYN_RESET_EACTION(s4, ipv4, bucket); #ifdef INET6 DYN_RESET_EACTION(s6, ipv6, bucket); #endif } } /* * Returns size of dynamic states in legacy format */ int ipfw_dyn_len(void) { return ((V_dyn_count + V_dyn_parent_count) * sizeof(ipfw_dyn_rule)); } /* * Returns number of dynamic states. * Marks every named object index used by dynamic states with bit in @bmask. * Returns number of named objects accounted in bmask via @nocnt. * Used by dump format v1 (current). */ uint32_t ipfw_dyn_get_count(uint32_t *bmask, int *nocnt) { #ifdef INET6 struct dyn_ipv6_state *s6; #endif struct dyn_ipv4_state *s4; uint32_t bucket; #define DYN_COUNT_OBJECTS(s, h, b) \ CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ MPASS(s->kidx != 0); \ if (ipfw_mark_object_kidx(bmask, IPFW_TLV_STATE_NAME, \ s->kidx) != 0) \ (*nocnt)++; \ } IPFW_UH_RLOCK_ASSERT(&V_layer3_chain); /* No need to pass through all the buckets. */ *nocnt = 0; if (V_dyn_count + V_dyn_parent_count == 0) return (0); for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { DYN_COUNT_OBJECTS(s4, ipv4, bucket); #ifdef INET6 DYN_COUNT_OBJECTS(s6, ipv6, bucket); #endif } return (V_dyn_count + V_dyn_parent_count); } /* * Check if rule contains at least one dynamic opcode. * * Returns 1 if such opcode is found, 0 otherwise. */ int ipfw_is_dyn_rule(struct ip_fw *rule) { int cmdlen, l; ipfw_insn *cmd; l = rule->cmd_len; cmd = rule->cmd; cmdlen = 0; for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) { cmdlen = F_LEN(cmd); switch (cmd->opcode) { case O_LIMIT: case O_KEEP_STATE: case O_PROBE_STATE: case O_CHECK_STATE: return (1); } } return (0); } static void dyn_export_parent(const struct dyn_parent *p, uint32_t kidx, uint8_t set, ipfw_dyn_rule *dst) { dst->type = O_LIMIT_PARENT; dst->set = set; dst->kidx = kidx; dst->rulenum = p->rulenum; dst->count = DPARENT_COUNT(p); dst->expire = TIME_LEQ(p->expire, time_uptime) ? 0: p->expire - time_uptime; dst->hashval = p->hashval; /* unused fields */ dst->pad = 0; dst->pcnt = 0; dst->bcnt = 0; dst->ack_fwd = 0; dst->ack_rev = 0; } static void dyn_export_data(const struct dyn_data *data, uint32_t kidx, uint8_t type, uint8_t set, ipfw_dyn_rule *dst) { dst->type = type; dst->set = set; dst->kidx = kidx; dst->rulenum = data->rulenum; dst->pcnt = data->pcnt_fwd + data->pcnt_rev; dst->bcnt = data->bcnt_fwd + data->bcnt_rev; dst->expire = TIME_LEQ(data->expire, time_uptime) ? 0: data->expire - time_uptime; dst->state = data->state; if (data->flags & DYN_REFERENCED) dst->state |= IPFW_DYN_ORPHANED; dst->ack_fwd = data->ack_fwd; dst->ack_rev = data->ack_rev; dst->hashval = data->hashval; } static void dyn_export_ipv4_state(const struct dyn_ipv4_state *s, ipfw_dyn_rule *dst) { struct ip_fw *rule; switch (s->type) { case O_LIMIT_PARENT: rule = s->limit->parent; dyn_export_parent(s->limit, s->kidx, rule->set, dst); break; default: rule = s->data->parent; if (s->type == O_LIMIT) rule = ((struct dyn_ipv4_state *)rule)->limit->parent; dyn_export_data(s->data, s->kidx, s->type, rule->set, dst); } dst->id.dst_ip = s->dst; dst->id.src_ip = s->src; dst->id.dst_port = s->dport; dst->id.src_port = s->sport; dst->id.fib = s->data->fibnum; dst->id.proto = s->proto; dst->id._flags = 0; dst->id.addr_type = 4; memset(&dst->id.dst_ip6, 0, sizeof(dst->id.dst_ip6)); memset(&dst->id.src_ip6, 0, sizeof(dst->id.src_ip6)); dst->id.flow_id6 = dst->id.extra = 0; } #ifdef INET6 static void dyn_export_ipv6_state(const struct dyn_ipv6_state *s, ipfw_dyn_rule *dst) { struct ip_fw *rule; switch (s->type) { case O_LIMIT_PARENT: rule = s->limit->parent; dyn_export_parent(s->limit, s->kidx, rule->set, dst); break; default: rule = s->data->parent; if (s->type == O_LIMIT) rule = ((struct dyn_ipv6_state *)rule)->limit->parent; dyn_export_data(s->data, s->kidx, s->type, rule->set, dst); } dst->id.src_ip6 = s->src; dst->id.dst_ip6 = s->dst; dst->id.dst_port = s->dport; dst->id.src_port = s->sport; dst->id.fib = s->data->fibnum; dst->id.proto = s->proto; dst->id._flags = 0; dst->id.addr_type = 6; dst->id.dst_ip = dst->id.src_ip = 0; dst->id.flow_id6 = dst->id.extra = 0; } #endif /* INET6 */ /* * Fills the buffer given by @sd with dynamic states. * Used by dump format v1 (current). * * Returns 0 on success. */ int ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd) { #ifdef INET6 struct dyn_ipv6_state *s6; #endif struct dyn_ipv4_state *s4; ipfw_obj_dyntlv *dst, *last; ipfw_obj_ctlv *ctlv; uint32_t bucket; if (V_dyn_count == 0) return (0); /* * IPFW_UH_RLOCK garantees that another userland request * and callout thread will not delete entries from states * lists. */ IPFW_UH_RLOCK_ASSERT(chain); ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv)); if (ctlv == NULL) return (ENOMEM); ctlv->head.type = IPFW_TLV_DYNSTATE_LIST; ctlv->objsize = sizeof(ipfw_obj_dyntlv); last = NULL; #define DYN_EXPORT_STATES(s, af, h, b) \ CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \ dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd, \ sizeof(ipfw_obj_dyntlv)); \ if (dst == NULL) \ return (ENOMEM); \ dyn_export_ ## af ## _state(s, &dst->state); \ dst->head.length = sizeof(ipfw_obj_dyntlv); \ dst->head.type = IPFW_TLV_DYN_ENT; \ last = dst; \ } for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket); DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket); #ifdef INET6 DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket); DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket); #endif /* INET6 */ } /* mark last dynamic rule */ if (last != NULL) last->head.flags = IPFW_DF_LAST; /* XXX: unused */ return (0); #undef DYN_EXPORT_STATES } /* * When we have enabled V_dyn_keep_states, states that become ORPHANED * will keep pointer to original rule. Then this rule pointer is used * to apply rule action after ipfw_dyn_lookup_state(). * Some rule actions use IPFW_INC_RULE_COUNTER() directly to this rule * pointer, but other actions use chain->map[f_pos] instead. The last * case leads to incrementing counters on the wrong rule, because * ORPHANED states have not parent rule in chain->map[]. * To solve this we add protected rule: * count ip from any to any not // comment * It will be matched only by packets that are handled by ORPHANED states. */ static void dyn_add_protected_rule(struct ip_fw_chain *chain) { static const char *comment = "orphaned dynamic states counter"; struct ip_fw *rule; ipfw_insn *cmd; size_t l; l = roundup(strlen(comment) + 1, sizeof(uint32_t)); rule = ipfw_alloc_rule(chain, sizeof(*rule) + sizeof(ipfw_insn) + l); cmd = rule->cmd; cmd->opcode = O_NOP; cmd->len = 1 + l/sizeof(uint32_t); cmd->len |= F_NOT; /* make rule to be not matched */ strcpy((char *)(cmd + 1), comment); cmd += F_LEN(cmd); cmd->len = 1; cmd->opcode = O_COUNT; rule->act_ofs = cmd - rule->cmd; rule->cmd_len = rule->act_ofs + 1; ipfw_add_protected_rule(chain, rule, 0); } void ipfw_dyn_init(struct ip_fw_chain *chain) { #ifdef IPFIREWALL_JENKINSHASH V_dyn_hashseed = arc4random(); #endif V_dyn_max = 16384; /* max # of states */ V_dyn_parent_max = 4096; /* max # of parent states */ V_dyn_buckets_max = 8192; /* must be power of 2 */ V_dyn_ack_lifetime = 300; V_dyn_syn_lifetime = 20; V_dyn_fin_lifetime = 1; V_dyn_rst_lifetime = 1; V_dyn_udp_lifetime = 10; V_dyn_short_lifetime = 5; V_dyn_keepalive_interval = 20; V_dyn_keepalive_period = 5; V_dyn_keepalive = 1; /* send keepalives */ V_dyn_keepalive_last = time_uptime; V_dyn_data_zone = uma_zcreate("IPFW dynamic states data", sizeof(struct dyn_data), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); uma_zone_set_max(V_dyn_data_zone, V_dyn_max); V_dyn_parent_zone = uma_zcreate("IPFW parent dynamic states", sizeof(struct dyn_parent), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max); SLIST_INIT(&V_dyn_expired_ipv4); V_dyn_ipv4 = NULL; V_dyn_ipv4_parent = NULL; V_dyn_ipv4_zone = uma_zcreate("IPFW IPv4 dynamic states", sizeof(struct dyn_ipv4_state), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); #ifdef INET6 SLIST_INIT(&V_dyn_expired_ipv6); V_dyn_ipv6 = NULL; V_dyn_ipv6_parent = NULL; V_dyn_ipv6_zone = uma_zcreate("IPFW IPv6 dynamic states", sizeof(struct dyn_ipv6_state), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0); #endif /* Initialize buckets. */ V_curr_dyn_buckets = 0; V_dyn_bucket_lock = NULL; dyn_grow_hashtable(chain, 256, M_WAITOK); if (IS_DEFAULT_VNET(curvnet)) dyn_hp_cache = malloc(mp_ncpus * sizeof(void *), M_IPFW, M_WAITOK | M_ZERO); DYN_EXPIRED_LOCK_INIT(); callout_init(&V_dyn_timeout, 1); callout_reset(&V_dyn_timeout, hz, dyn_tick, curvnet); IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes); dyn_add_protected_rule(chain); } void ipfw_dyn_uninit(int pass) { #ifdef INET6 struct dyn_ipv6_state *s6; #endif struct dyn_ipv4_state *s4; int bucket; if (pass == 0) { callout_drain(&V_dyn_timeout); return; } IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes); DYN_EXPIRED_LOCK_DESTROY(); #define DYN_FREE_STATES_FORCED(CK, s, af, name, en) do { \ while ((s = CK ## SLIST_FIRST(&V_dyn_ ## name)) != NULL) { \ CK ## SLIST_REMOVE_HEAD(&V_dyn_ ## name, en); \ if (s->type == O_LIMIT_PARENT) \ uma_zfree(V_dyn_parent_zone, s->limit); \ else \ uma_zfree(V_dyn_data_zone, s->data); \ uma_zfree(V_dyn_ ## af ## _zone, s); \ } \ } while (0) for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) { DYN_BUCKET_LOCK_DESTROY(V_dyn_bucket_lock, bucket); DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4[bucket], entry); DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4_parent[bucket], entry); #ifdef INET6 DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6[bucket], entry); DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6_parent[bucket], entry); #endif /* INET6 */ } DYN_FREE_STATES_FORCED(, s4, ipv4, expired_ipv4, expired); #ifdef INET6 DYN_FREE_STATES_FORCED(, s6, ipv6, expired_ipv6, expired); #endif #undef DYN_FREE_STATES_FORCED uma_zdestroy(V_dyn_ipv4_zone); uma_zdestroy(V_dyn_data_zone); uma_zdestroy(V_dyn_parent_zone); #ifdef INET6 uma_zdestroy(V_dyn_ipv6_zone); free(V_dyn_ipv6, M_IPFW); free(V_dyn_ipv6_parent, M_IPFW); free(V_dyn_ipv6_add, M_IPFW); free(V_dyn_ipv6_parent_add, M_IPFW); free(V_dyn_ipv6_del, M_IPFW); free(V_dyn_ipv6_parent_del, M_IPFW); #endif free(V_dyn_bucket_lock, M_IPFW); free(V_dyn_ipv4, M_IPFW); free(V_dyn_ipv4_parent, M_IPFW); free(V_dyn_ipv4_add, M_IPFW); free(V_dyn_ipv4_parent_add, M_IPFW); free(V_dyn_ipv4_del, M_IPFW); free(V_dyn_ipv4_parent_del, M_IPFW); if (IS_DEFAULT_VNET(curvnet)) free(dyn_hp_cache, M_IPFW); }