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pf.c
8341 lines (7455 loc) · 212 KB
/
pf.c
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/* $OpenBSD: pf.c,v 1.1193 2024/01/10 16:44:30 bluhm Exp $ */
/*
* Copyright (c) 2001 Daniel Hartmeier
* Copyright (c) 2002 - 2013 Henning Brauer <henning@openbsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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 COPYRIGHT HOLDERS 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
* COPYRIGHT HOLDERS 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.
*
* Effort sponsored in part by the Defense Advanced Research Projects
* Agency (DARPA) and Air Force Research Laboratory, Air Force
* Materiel Command, USAF, under agreement number F30602-01-2-0537.
*
*/
#include "bpfilter.h"
#include "carp.h"
#include "pflog.h"
#include "pfsync.h"
#include "pflow.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/filio.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/syslog.h>
#include <crypto/sha2.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/toeplitz.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcp_fsm.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet/ip_divert.h>
#ifdef INET6
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>
#include <netinet6/ip6_divert.h>
#endif /* INET6 */
#include <net/pfvar.h>
#include <net/pfvar_priv.h>
#if NPFLOG > 0
#include <net/if_pflog.h>
#endif /* NPFLOG > 0 */
#if NPFLOW > 0
#include <net/if_pflow.h>
#endif /* NPFLOW > 0 */
#if NPFSYNC > 0
#include <net/if_pfsync.h>
#endif /* NPFSYNC > 0 */
/*
* Global variables
*/
struct pf_state_tree pf_statetbl;
struct pf_queuehead pf_queues[2];
struct pf_queuehead *pf_queues_active;
struct pf_queuehead *pf_queues_inactive;
struct pf_status pf_status;
struct mutex pf_inp_mtx = MUTEX_INITIALIZER(IPL_SOFTNET);
int pf_hdr_limit = 20; /* arbitrary limit, tune in ddb */
SHA2_CTX pf_tcp_secret_ctx;
u_char pf_tcp_secret[16];
int pf_tcp_secret_init;
int pf_tcp_iss_off;
enum pf_test_status {
PF_TEST_FAIL = -1,
PF_TEST_OK,
PF_TEST_QUICK
};
struct pf_test_ctx {
struct pf_pdesc *pd;
struct pf_rule_actions act;
u_int8_t icmpcode;
u_int8_t icmptype;
int icmp_dir;
int state_icmp;
int tag;
u_short reason;
struct pf_rule_item *ri;
struct pf_src_node *sns[PF_SN_MAX];
struct pf_rule_slist rules;
struct pf_rule *nr;
struct pf_rule **rm;
struct pf_rule *a;
struct pf_rule **am;
struct pf_ruleset **rsm;
struct pf_ruleset *arsm;
struct pf_ruleset *aruleset;
struct tcphdr *th;
};
struct pool pf_src_tree_pl, pf_rule_pl, pf_queue_pl;
struct pool pf_state_pl, pf_state_key_pl, pf_state_item_pl;
struct pool pf_rule_item_pl, pf_sn_item_pl, pf_pktdelay_pl;
void pf_add_threshold(struct pf_threshold *);
int pf_check_threshold(struct pf_threshold *);
int pf_check_tcp_cksum(struct mbuf *, int, int,
sa_family_t);
__inline void pf_cksum_fixup(u_int16_t *, u_int16_t, u_int16_t,
u_int8_t);
void pf_cksum_fixup_a(u_int16_t *, const struct pf_addr *,
const struct pf_addr *, sa_family_t, u_int8_t);
int pf_modulate_sack(struct pf_pdesc *,
struct pf_state_peer *);
int pf_icmp_mapping(struct pf_pdesc *, u_int8_t, int *,
u_int16_t *, u_int16_t *);
int pf_change_icmp_af(struct mbuf *, int,
struct pf_pdesc *, struct pf_pdesc *,
struct pf_addr *, struct pf_addr *, sa_family_t,
sa_family_t);
int pf_translate_a(struct pf_pdesc *, struct pf_addr *,
struct pf_addr *);
void pf_translate_icmp(struct pf_pdesc *, struct pf_addr *,
u_int16_t *, struct pf_addr *, struct pf_addr *,
u_int16_t);
int pf_translate_icmp_af(struct pf_pdesc*, int, void *);
void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t, int,
sa_family_t, struct pf_rule *, u_int);
void pf_detach_state(struct pf_state *);
struct pf_state_key *pf_state_key_attach(struct pf_state_key *,
struct pf_state *, int);
void pf_state_key_detach(struct pf_state *, int);
u_int32_t pf_tcp_iss(struct pf_pdesc *);
void pf_rule_to_actions(struct pf_rule *,
struct pf_rule_actions *);
int pf_test_rule(struct pf_pdesc *, struct pf_rule **,
struct pf_state **, struct pf_rule **,
struct pf_ruleset **, u_short *);
static __inline int pf_create_state(struct pf_pdesc *, struct pf_rule *,
struct pf_rule *, struct pf_rule *,
struct pf_state_key **, struct pf_state_key **,
int *, struct pf_state **, int,
struct pf_rule_slist *, struct pf_rule_actions *,
struct pf_src_node **);
static __inline int pf_state_key_addr_setup(struct pf_pdesc *, void *,
int, struct pf_addr *, int, struct pf_addr *,
int, int);
int pf_state_key_setup(struct pf_pdesc *, struct
pf_state_key **, struct pf_state_key **, int);
int pf_tcp_track_full(struct pf_pdesc *,
struct pf_state **, u_short *, int *, int);
int pf_tcp_track_sloppy(struct pf_pdesc *,
struct pf_state **, u_short *);
static __inline int pf_synproxy(struct pf_pdesc *, struct pf_state **,
u_short *);
int pf_test_state(struct pf_pdesc *, struct pf_state **,
u_short *);
int pf_icmp_state_lookup(struct pf_pdesc *,
struct pf_state_key_cmp *, struct pf_state **,
u_int16_t, u_int16_t, int, int *, int, int);
int pf_test_state_icmp(struct pf_pdesc *,
struct pf_state **, u_short *);
u_int16_t pf_calc_mss(struct pf_addr *, sa_family_t, int,
u_int16_t);
static __inline int pf_set_rt_ifp(struct pf_state *, struct pf_addr *,
sa_family_t, struct pf_src_node **);
struct pf_divert *pf_get_divert(struct mbuf *);
int pf_walk_option(struct pf_pdesc *, struct ip *,
int, int, u_short *);
int pf_walk_header(struct pf_pdesc *, struct ip *,
u_short *);
int pf_walk_option6(struct pf_pdesc *, struct ip6_hdr *,
int, int, u_short *);
int pf_walk_header6(struct pf_pdesc *, struct ip6_hdr *,
u_short *);
void pf_print_state_parts(struct pf_state *,
struct pf_state_key *, struct pf_state_key *);
int pf_addr_wrap_neq(struct pf_addr_wrap *,
struct pf_addr_wrap *);
int pf_compare_state_keys(struct pf_state_key *,
struct pf_state_key *, struct pfi_kif *, u_int);
u_int16_t pf_pkt_hash(sa_family_t, uint8_t,
const struct pf_addr *, const struct pf_addr *,
uint16_t, uint16_t);
int pf_find_state(struct pf_pdesc *,
struct pf_state_key_cmp *, struct pf_state **);
int pf_src_connlimit(struct pf_state **);
int pf_match_rcvif(struct mbuf *, struct pf_rule *);
int pf_step_into_anchor(struct pf_test_ctx *,
struct pf_rule *);
int pf_match_rule(struct pf_test_ctx *,
struct pf_ruleset *);
void pf_counters_inc(int, struct pf_pdesc *,
struct pf_state *, struct pf_rule *,
struct pf_rule *);
int pf_state_insert(struct pfi_kif *,
struct pf_state_key **, struct pf_state_key **,
struct pf_state *);
int pf_state_key_isvalid(struct pf_state_key *);
struct pf_state_key *pf_state_key_ref(struct pf_state_key *);
void pf_state_key_unref(struct pf_state_key *);
void pf_state_key_link_reverse(struct pf_state_key *,
struct pf_state_key *);
void pf_state_key_unlink_reverse(struct pf_state_key *);
void pf_state_key_link_inpcb(struct pf_state_key *,
struct inpcb *);
void pf_state_key_unlink_inpcb(struct pf_state_key *);
void pf_pktenqueue_delayed(void *);
int32_t pf_state_expires(const struct pf_state *, uint8_t);
#if NPFLOG > 0
void pf_log_matches(struct pf_pdesc *, struct pf_rule *,
struct pf_rule *, struct pf_ruleset *,
struct pf_rule_slist *);
#endif /* NPFLOG > 0 */
extern struct pool pfr_ktable_pl;
extern struct pool pfr_kentry_pl;
struct pf_pool_limit pf_pool_limits[PF_LIMIT_MAX] = {
{ &pf_state_pl, PFSTATE_HIWAT, PFSTATE_HIWAT },
{ &pf_src_tree_pl, PFSNODE_HIWAT, PFSNODE_HIWAT },
{ &pf_frent_pl, PFFRAG_FRENT_HIWAT, PFFRAG_FRENT_HIWAT },
{ &pfr_ktable_pl, PFR_KTABLE_HIWAT, PFR_KTABLE_HIWAT },
{ &pfr_kentry_pl, PFR_KENTRY_HIWAT, PFR_KENTRY_HIWAT },
{ &pf_pktdelay_pl, PF_PKTDELAY_MAXPKTS, PF_PKTDELAY_MAXPKTS },
{ &pf_anchor_pl, PF_ANCHOR_HIWAT, PF_ANCHOR_HIWAT }
};
#define BOUND_IFACE(r, k) \
((r)->rule_flag & PFRULE_IFBOUND) ? (k) : pfi_all
#define STATE_INC_COUNTERS(s) \
do { \
struct pf_rule_item *mrm; \
s->rule.ptr->states_cur++; \
s->rule.ptr->states_tot++; \
if (s->anchor.ptr != NULL) { \
s->anchor.ptr->states_cur++; \
s->anchor.ptr->states_tot++; \
} \
SLIST_FOREACH(mrm, &s->match_rules, entry) \
mrm->r->states_cur++; \
} while (0)
static __inline int pf_src_compare(struct pf_src_node *, struct pf_src_node *);
static inline int pf_state_compare_key(const struct pf_state_key *,
const struct pf_state_key *);
static inline int pf_state_compare_id(const struct pf_state *,
const struct pf_state *);
#ifdef INET6
static __inline void pf_cksum_uncover(u_int16_t *, u_int16_t, u_int8_t);
static __inline void pf_cksum_cover(u_int16_t *, u_int16_t, u_int8_t);
#endif /* INET6 */
static __inline void pf_set_protostate(struct pf_state *, int, u_int8_t);
struct pf_src_tree tree_src_tracking;
struct pf_state_tree_id tree_id;
struct pf_state_list pf_state_list = PF_STATE_LIST_INITIALIZER(pf_state_list);
RB_GENERATE(pf_src_tree, pf_src_node, entry, pf_src_compare);
RBT_GENERATE(pf_state_tree, pf_state_key, sk_entry, pf_state_compare_key);
RBT_GENERATE(pf_state_tree_id, pf_state, entry_id, pf_state_compare_id);
int
pf_addr_compare(const struct pf_addr *a, const struct pf_addr *b,
sa_family_t af)
{
switch (af) {
case AF_INET:
if (a->addr32[0] > b->addr32[0])
return (1);
if (a->addr32[0] < b->addr32[0])
return (-1);
break;
#ifdef INET6
case AF_INET6:
if (a->addr32[3] > b->addr32[3])
return (1);
if (a->addr32[3] < b->addr32[3])
return (-1);
if (a->addr32[2] > b->addr32[2])
return (1);
if (a->addr32[2] < b->addr32[2])
return (-1);
if (a->addr32[1] > b->addr32[1])
return (1);
if (a->addr32[1] < b->addr32[1])
return (-1);
if (a->addr32[0] > b->addr32[0])
return (1);
if (a->addr32[0] < b->addr32[0])
return (-1);
break;
#endif /* INET6 */
}
return (0);
}
static __inline int
pf_src_compare(struct pf_src_node *a, struct pf_src_node *b)
{
int diff;
if (a->rule.ptr > b->rule.ptr)
return (1);
if (a->rule.ptr < b->rule.ptr)
return (-1);
if ((diff = a->type - b->type) != 0)
return (diff);
if ((diff = a->af - b->af) != 0)
return (diff);
if ((diff = pf_addr_compare(&a->addr, &b->addr, a->af)) != 0)
return (diff);
return (0);
}
static __inline void
pf_set_protostate(struct pf_state *st, int which, u_int8_t newstate)
{
if (which == PF_PEER_DST || which == PF_PEER_BOTH)
st->dst.state = newstate;
if (which == PF_PEER_DST)
return;
if (st->src.state == newstate)
return;
if (st->creatorid == pf_status.hostid &&
st->key[PF_SK_STACK]->proto == IPPROTO_TCP &&
!(TCPS_HAVEESTABLISHED(st->src.state) ||
st->src.state == TCPS_CLOSED) &&
(TCPS_HAVEESTABLISHED(newstate) || newstate == TCPS_CLOSED))
pf_status.states_halfopen--;
st->src.state = newstate;
}
void
pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af)
{
switch (af) {
case AF_INET:
dst->addr32[0] = src->addr32[0];
break;
#ifdef INET6
case AF_INET6:
dst->addr32[0] = src->addr32[0];
dst->addr32[1] = src->addr32[1];
dst->addr32[2] = src->addr32[2];
dst->addr32[3] = src->addr32[3];
break;
#endif /* INET6 */
default:
unhandled_af(af);
}
}
void
pf_init_threshold(struct pf_threshold *threshold,
u_int32_t limit, u_int32_t seconds)
{
threshold->limit = limit * PF_THRESHOLD_MULT;
threshold->seconds = seconds;
threshold->count = 0;
threshold->last = getuptime();
}
void
pf_add_threshold(struct pf_threshold *threshold)
{
u_int32_t t = getuptime(), diff = t - threshold->last;
if (diff >= threshold->seconds)
threshold->count = 0;
else
threshold->count -= threshold->count * diff /
threshold->seconds;
threshold->count += PF_THRESHOLD_MULT;
threshold->last = t;
}
int
pf_check_threshold(struct pf_threshold *threshold)
{
return (threshold->count > threshold->limit);
}
void
pf_state_list_insert(struct pf_state_list *pfs, struct pf_state *st)
{
/*
* we can always put states on the end of the list.
*
* things reading the list should take a read lock, then
* the mutex, get the head and tail pointers, release the
* mutex, and then they can iterate between the head and tail.
*/
pf_state_ref(st); /* get a ref for the list */
mtx_enter(&pfs->pfs_mtx);
TAILQ_INSERT_TAIL(&pfs->pfs_list, st, entry_list);
mtx_leave(&pfs->pfs_mtx);
}
void
pf_state_list_remove(struct pf_state_list *pfs, struct pf_state *st)
{
/* states can only be removed when the write lock is held */
rw_assert_wrlock(&pfs->pfs_rwl);
mtx_enter(&pfs->pfs_mtx);
TAILQ_REMOVE(&pfs->pfs_list, st, entry_list);
mtx_leave(&pfs->pfs_mtx);
pf_state_unref(st); /* list no longer references the state */
}
void
pf_update_state_timeout(struct pf_state *st, int to)
{
mtx_enter(&st->mtx);
if (st->timeout != PFTM_UNLINKED)
st->timeout = to;
mtx_leave(&st->mtx);
}
int
pf_src_connlimit(struct pf_state **stp)
{
int bad = 0;
struct pf_src_node *sn;
if ((sn = pf_get_src_node((*stp), PF_SN_NONE)) == NULL)
return (0);
sn->conn++;
(*stp)->src.tcp_est = 1;
pf_add_threshold(&sn->conn_rate);
if ((*stp)->rule.ptr->max_src_conn &&
(*stp)->rule.ptr->max_src_conn < sn->conn) {
pf_status.lcounters[LCNT_SRCCONN]++;
bad++;
}
if ((*stp)->rule.ptr->max_src_conn_rate.limit &&
pf_check_threshold(&sn->conn_rate)) {
pf_status.lcounters[LCNT_SRCCONNRATE]++;
bad++;
}
if (!bad)
return (0);
if ((*stp)->rule.ptr->overload_tbl) {
struct pfr_addr p;
u_int32_t killed = 0;
pf_status.lcounters[LCNT_OVERLOAD_TABLE]++;
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: pf_src_connlimit: blocking address ");
pf_print_host(&sn->addr, 0,
(*stp)->key[PF_SK_WIRE]->af);
}
memset(&p, 0, sizeof(p));
p.pfra_af = (*stp)->key[PF_SK_WIRE]->af;
switch ((*stp)->key[PF_SK_WIRE]->af) {
case AF_INET:
p.pfra_net = 32;
p.pfra_ip4addr = sn->addr.v4;
break;
#ifdef INET6
case AF_INET6:
p.pfra_net = 128;
p.pfra_ip6addr = sn->addr.v6;
break;
#endif /* INET6 */
}
pfr_insert_kentry((*stp)->rule.ptr->overload_tbl,
&p, gettime());
/* kill existing states if that's required. */
if ((*stp)->rule.ptr->flush) {
struct pf_state_key *sk;
struct pf_state *st;
pf_status.lcounters[LCNT_OVERLOAD_FLUSH]++;
RBT_FOREACH(st, pf_state_tree_id, &tree_id) {
sk = st->key[PF_SK_WIRE];
/*
* Kill states from this source. (Only those
* from the same rule if PF_FLUSH_GLOBAL is not
* set)
*/
if (sk->af ==
(*stp)->key[PF_SK_WIRE]->af &&
(((*stp)->direction == PF_OUT &&
PF_AEQ(&sn->addr, &sk->addr[1], sk->af)) ||
((*stp)->direction == PF_IN &&
PF_AEQ(&sn->addr, &sk->addr[0], sk->af))) &&
((*stp)->rule.ptr->flush &
PF_FLUSH_GLOBAL ||
(*stp)->rule.ptr == st->rule.ptr)) {
pf_update_state_timeout(st, PFTM_PURGE);
pf_set_protostate(st, PF_PEER_BOTH,
TCPS_CLOSED);
killed++;
}
}
if (pf_status.debug >= LOG_NOTICE)
addlog(", %u states killed", killed);
}
if (pf_status.debug >= LOG_NOTICE)
addlog("\n");
}
/* kill this state */
pf_update_state_timeout(*stp, PFTM_PURGE);
pf_set_protostate(*stp, PF_PEER_BOTH, TCPS_CLOSED);
return (1);
}
int
pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule,
enum pf_sn_types type, sa_family_t af, struct pf_addr *src,
struct pf_addr *raddr, struct pfi_kif *kif)
{
struct pf_src_node k;
if (*sn == NULL) {
k.af = af;
k.type = type;
pf_addrcpy(&k.addr, src, af);
k.rule.ptr = rule;
pf_status.scounters[SCNT_SRC_NODE_SEARCH]++;
*sn = RB_FIND(pf_src_tree, &tree_src_tracking, &k);
}
if (*sn == NULL) {
if (!rule->max_src_nodes ||
rule->src_nodes < rule->max_src_nodes)
(*sn) = pool_get(&pf_src_tree_pl, PR_NOWAIT | PR_ZERO);
else
pf_status.lcounters[LCNT_SRCNODES]++;
if ((*sn) == NULL)
return (-1);
pf_init_threshold(&(*sn)->conn_rate,
rule->max_src_conn_rate.limit,
rule->max_src_conn_rate.seconds);
(*sn)->type = type;
(*sn)->af = af;
(*sn)->rule.ptr = rule;
pf_addrcpy(&(*sn)->addr, src, af);
if (raddr)
pf_addrcpy(&(*sn)->raddr, raddr, af);
if (RB_INSERT(pf_src_tree,
&tree_src_tracking, *sn) != NULL) {
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: src_tree insert failed: ");
pf_print_host(&(*sn)->addr, 0, af);
addlog("\n");
}
pool_put(&pf_src_tree_pl, *sn);
return (-1);
}
(*sn)->creation = getuptime();
(*sn)->rule.ptr->src_nodes++;
if (kif != NULL) {
(*sn)->kif = kif;
pfi_kif_ref(kif, PFI_KIF_REF_SRCNODE);
}
pf_status.scounters[SCNT_SRC_NODE_INSERT]++;
pf_status.src_nodes++;
} else {
if (rule->max_src_states &&
(*sn)->states >= rule->max_src_states) {
pf_status.lcounters[LCNT_SRCSTATES]++;
return (-1);
}
}
return (0);
}
void
pf_remove_src_node(struct pf_src_node *sn)
{
if (sn->states > 0 || sn->expire > getuptime())
return;
sn->rule.ptr->src_nodes--;
if (sn->rule.ptr->states_cur == 0 &&
sn->rule.ptr->src_nodes == 0)
pf_rm_rule(NULL, sn->rule.ptr);
RB_REMOVE(pf_src_tree, &tree_src_tracking, sn);
pf_status.scounters[SCNT_SRC_NODE_REMOVALS]++;
pf_status.src_nodes--;
pfi_kif_unref(sn->kif, PFI_KIF_REF_SRCNODE);
pool_put(&pf_src_tree_pl, sn);
}
struct pf_src_node *
pf_get_src_node(struct pf_state *st, enum pf_sn_types type)
{
struct pf_sn_item *sni;
SLIST_FOREACH(sni, &st->src_nodes, next)
if (sni->sn->type == type)
return (sni->sn);
return (NULL);
}
void
pf_state_rm_src_node(struct pf_state *st, struct pf_src_node *sn)
{
struct pf_sn_item *sni, *snin, *snip = NULL;
for (sni = SLIST_FIRST(&st->src_nodes); sni; sni = snin) {
snin = SLIST_NEXT(sni, next);
if (sni->sn == sn) {
if (snip)
SLIST_REMOVE_AFTER(snip, next);
else
SLIST_REMOVE_HEAD(&st->src_nodes, next);
pool_put(&pf_sn_item_pl, sni);
sni = NULL;
sn->states--;
}
if (sni != NULL)
snip = sni;
}
}
/* state table stuff */
static inline int
pf_state_compare_key(const struct pf_state_key *a,
const struct pf_state_key *b)
{
int diff;
if ((diff = a->hash - b->hash) != 0)
return (diff);
if ((diff = a->proto - b->proto) != 0)
return (diff);
if ((diff = a->af - b->af) != 0)
return (diff);
if ((diff = pf_addr_compare(&a->addr[0], &b->addr[0], a->af)) != 0)
return (diff);
if ((diff = pf_addr_compare(&a->addr[1], &b->addr[1], a->af)) != 0)
return (diff);
if ((diff = a->port[0] - b->port[0]) != 0)
return (diff);
if ((diff = a->port[1] - b->port[1]) != 0)
return (diff);
if ((diff = a->rdomain - b->rdomain) != 0)
return (diff);
return (0);
}
static inline int
pf_state_compare_id(const struct pf_state *a, const struct pf_state *b)
{
if (a->id > b->id)
return (1);
if (a->id < b->id)
return (-1);
if (a->creatorid > b->creatorid)
return (1);
if (a->creatorid < b->creatorid)
return (-1);
return (0);
}
/*
* on failure, pf_state_key_attach() releases the pf_state_key
* reference and returns NULL.
*/
struct pf_state_key *
pf_state_key_attach(struct pf_state_key *sk, struct pf_state *st, int idx)
{
struct pf_state_item *si;
struct pf_state_key *cur;
struct pf_state *oldst = NULL;
PF_ASSERT_LOCKED();
KASSERT(st->key[idx] == NULL);
sk->sk_removed = 0;
cur = RBT_INSERT(pf_state_tree, &pf_statetbl, sk);
if (cur != NULL) {
sk->sk_removed = 1;
/* key exists. check for same kif, if none, add to key */
TAILQ_FOREACH(si, &cur->sk_states, si_entry) {
struct pf_state *sist = si->si_st;
if (sist->kif == st->kif &&
((sist->key[PF_SK_WIRE]->af == sk->af &&
sist->direction == st->direction) ||
(sist->key[PF_SK_WIRE]->af !=
sist->key[PF_SK_STACK]->af &&
sk->af == sist->key[PF_SK_STACK]->af &&
sist->direction != st->direction))) {
int reuse = 0;
if (sk->proto == IPPROTO_TCP &&
sist->src.state >= TCPS_FIN_WAIT_2 &&
sist->dst.state >= TCPS_FIN_WAIT_2)
reuse = 1;
if (pf_status.debug >= LOG_NOTICE) {
log(LOG_NOTICE,
"pf: %s key attach %s on %s: ",
(idx == PF_SK_WIRE) ?
"wire" : "stack",
reuse ? "reuse" : "failed",
st->kif->pfik_name);
pf_print_state_parts(st,
(idx == PF_SK_WIRE) ? sk : NULL,
(idx == PF_SK_STACK) ? sk : NULL);
addlog(", existing: ");
pf_print_state_parts(sist,
(idx == PF_SK_WIRE) ? sk : NULL,
(idx == PF_SK_STACK) ? sk : NULL);
addlog("\n");
}
if (reuse) {
pf_set_protostate(sist, PF_PEER_BOTH,
TCPS_CLOSED);
/* remove late or sks can go away */
oldst = sist;
} else {
pf_state_key_unref(sk);
return (NULL); /* collision! */
}
}
}
/* reuse the existing state key */
pf_state_key_unref(sk);
sk = cur;
}
if ((si = pool_get(&pf_state_item_pl, PR_NOWAIT)) == NULL) {
if (TAILQ_EMPTY(&sk->sk_states)) {
KASSERT(cur == NULL);
RBT_REMOVE(pf_state_tree, &pf_statetbl, sk);
sk->sk_removed = 1;
pf_state_key_unref(sk);
}
return (NULL);
}
st->key[idx] = pf_state_key_ref(sk); /* give a ref to state */
si->si_st = pf_state_ref(st);
/* list is sorted, if-bound states before floating */
if (st->kif == pfi_all)
TAILQ_INSERT_TAIL(&sk->sk_states, si, si_entry);
else
TAILQ_INSERT_HEAD(&sk->sk_states, si, si_entry);
if (oldst)
pf_remove_state(oldst);
/* caller owns the pf_state ref, which owns a pf_state_key ref now */
return (sk);
}
void
pf_detach_state(struct pf_state *st)
{
KASSERT(st->key[PF_SK_WIRE] != NULL);
pf_state_key_detach(st, PF_SK_WIRE);
KASSERT(st->key[PF_SK_STACK] != NULL);
if (st->key[PF_SK_STACK] != st->key[PF_SK_WIRE])
pf_state_key_detach(st, PF_SK_STACK);
}
void
pf_state_key_detach(struct pf_state *st, int idx)
{
struct pf_state_item *si;
struct pf_state_key *sk;
PF_ASSERT_LOCKED();
sk = st->key[idx];
if (sk == NULL)
return;
TAILQ_FOREACH(si, &sk->sk_states, si_entry) {
if (si->si_st == st)
break;
}
if (si == NULL)
return;
TAILQ_REMOVE(&sk->sk_states, si, si_entry);
pool_put(&pf_state_item_pl, si);
if (TAILQ_EMPTY(&sk->sk_states)) {
RBT_REMOVE(pf_state_tree, &pf_statetbl, sk);
sk->sk_removed = 1;
pf_state_key_unlink_reverse(sk);
pf_state_key_unlink_inpcb(sk);
pf_state_key_unref(sk);
}
pf_state_unref(st);
}
struct pf_state_key *
pf_alloc_state_key(int pool_flags)
{
struct pf_state_key *sk;
if ((sk = pool_get(&pf_state_key_pl, pool_flags)) == NULL)
return (NULL);
PF_REF_INIT(sk->sk_refcnt);
TAILQ_INIT(&sk->sk_states);
sk->sk_removed = 1;
return (sk);
}
static __inline int
pf_state_key_addr_setup(struct pf_pdesc *pd, void *arg, int sidx,
struct pf_addr *saddr, int didx, struct pf_addr *daddr, int af, int multi)
{
struct pf_state_key_cmp *key = arg;
#ifdef INET6
struct pf_addr *target;
if (af == AF_INET || pd->proto != IPPROTO_ICMPV6)
goto copy;
switch (pd->hdr.icmp6.icmp6_type) {
case ND_NEIGHBOR_SOLICIT:
if (multi)
return (-1);
target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target;
daddr = target;
break;
case ND_NEIGHBOR_ADVERT:
if (multi)
return (-1);
target = (struct pf_addr *)&pd->hdr.nd_ns.nd_ns_target;
saddr = target;
if (IN6_IS_ADDR_MULTICAST(&pd->dst->v6)) {
key->addr[didx].addr32[0] = 0;
key->addr[didx].addr32[1] = 0;
key->addr[didx].addr32[2] = 0;
key->addr[didx].addr32[3] = 0;
daddr = NULL; /* overwritten */
}
break;
default:
if (multi) {
key->addr[sidx].addr32[0] = __IPV6_ADDR_INT32_MLL;
key->addr[sidx].addr32[1] = 0;
key->addr[sidx].addr32[2] = 0;
key->addr[sidx].addr32[3] = __IPV6_ADDR_INT32_ONE;
saddr = NULL; /* overwritten */
}
}
copy:
#endif /* INET6 */
if (saddr)
pf_addrcpy(&key->addr[sidx], saddr, af);
if (daddr)
pf_addrcpy(&key->addr[didx], daddr, af);
return (0);
}
int
pf_state_key_setup(struct pf_pdesc *pd, struct pf_state_key **skw,
struct pf_state_key **sks, int rtableid)
{
/* if returning error we MUST pool_put state keys ourselves */
struct pf_state_key *sk1, *sk2;
u_int wrdom = pd->rdomain;
int afto = pd->af != pd->naf;
if ((sk1 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL)
return (ENOMEM);
pf_state_key_addr_setup(pd, sk1, pd->sidx, pd->src, pd->didx, pd->dst,
pd->af, 0);
sk1->port[pd->sidx] = pd->osport;
sk1->port[pd->didx] = pd->odport;
sk1->proto = pd->proto;
sk1->af = pd->af;
sk1->rdomain = pd->rdomain;
sk1->hash = pf_pkt_hash(sk1->af, sk1->proto,
&sk1->addr[0], &sk1->addr[1], sk1->port[0], sk1->port[1]);
if (rtableid >= 0)
wrdom = rtable_l2(rtableid);
if (PF_ANEQ(&pd->nsaddr, pd->src, pd->af) ||
PF_ANEQ(&pd->ndaddr, pd->dst, pd->af) ||
pd->nsport != pd->osport || pd->ndport != pd->odport ||
wrdom != pd->rdomain || afto) { /* NAT/NAT64 */
if ((sk2 = pf_alloc_state_key(PR_NOWAIT | PR_ZERO)) == NULL) {
pf_state_key_unref(sk1);
return (ENOMEM);
}
pf_state_key_addr_setup(pd, sk2, afto ? pd->didx : pd->sidx,
&pd->nsaddr, afto ? pd->sidx : pd->didx, &pd->ndaddr,
pd->naf, 0);
sk2->port[afto ? pd->didx : pd->sidx] = pd->nsport;
sk2->port[afto ? pd->sidx : pd->didx] = pd->ndport;
if (afto) {
switch (pd->proto) {
case IPPROTO_ICMP:
sk2->proto = IPPROTO_ICMPV6;
break;
case IPPROTO_ICMPV6:
sk2->proto = IPPROTO_ICMP;
break;
default:
sk2->proto = pd->proto;
}
} else
sk2->proto = pd->proto;
sk2->af = pd->naf;
sk2->rdomain = wrdom;
sk2->hash = pf_pkt_hash(sk2->af, sk2->proto,
&sk2->addr[0], &sk2->addr[1], sk2->port[0], sk2->port[1]);
} else
sk2 = pf_state_key_ref(sk1);
if (pd->dir == PF_IN) {
*skw = sk1;
*sks = sk2;
} else {
*sks = sk1;
*skw = sk2;