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39a58828ef
freebsd-nq/sys/netpfil/pf/pf.c
Gleb Smirnoff 39a58828ef In the forwarding case refragment the reassembled packets with the same 
size as they arrived in. This allows the sender to determine the optimal
fragment size by Path MTU Discovery.

Roughly based on the OpenBSD work by Alexander Bluhm.

Submitted by:		Kristof Provost
Differential Revision:	D1767
2015-02-16 07:01:02 +00:00

6443 lines
164 KiB
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/*-
* Copyright (c) 2001 Daniel Hartmeier
* Copyright (c) 2002 - 2008 Henning Brauer
* Copyright (c) 2012 Gleb Smirnoff <glebius@FreeBSD.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.
*
* $OpenBSD: pf.c,v 1.634 2009/02/27 12:37:45 henning Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_bpf.h"
#include "opt_pf.h"
#include <sys/param.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/hash.h>
#include <sys/interrupt.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/limits.h>
#include <sys/mbuf.h>
#include <sys/md5.h>
#include <sys/random.h>
#include <sys/refcount.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>
#include <sys/ucred.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/radix_mpath.h>
#include <net/vnet.h>
#include <net/pfvar.h>
#include <net/if_pflog.h>
#include <net/if_pfsync.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_fw.h>
#include <netinet/ip_icmp.h>
#include <netinet/icmp_var.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netpfil/ipfw/ip_fw_private.h> /* XXX: only for DIR_IN/DIR_OUT */
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/in6_pcb.h>
#endif /* INET6 */
#include <machine/in_cksum.h>
#include <security/mac/mac_framework.h>
#define DPFPRINTF(n, x) if (V_pf_status.debug >= (n)) printf x
/*
* Global variables
*/
/* state tables */
VNET_DEFINE(struct pf_altqqueue, pf_altqs[2]);
VNET_DEFINE(struct pf_palist, pf_pabuf);
VNET_DEFINE(struct pf_altqqueue *, pf_altqs_active);
VNET_DEFINE(struct pf_altqqueue *, pf_altqs_inactive);
VNET_DEFINE(struct pf_kstatus, pf_status);
VNET_DEFINE(u_int32_t, ticket_altqs_active);
VNET_DEFINE(u_int32_t, ticket_altqs_inactive);
VNET_DEFINE(int, altqs_inactive_open);
VNET_DEFINE(u_int32_t, ticket_pabuf);
VNET_DEFINE(MD5_CTX, pf_tcp_secret_ctx);
#define V_pf_tcp_secret_ctx VNET(pf_tcp_secret_ctx)
VNET_DEFINE(u_char, pf_tcp_secret[16]);
#define V_pf_tcp_secret VNET(pf_tcp_secret)
VNET_DEFINE(int, pf_tcp_secret_init);
#define V_pf_tcp_secret_init VNET(pf_tcp_secret_init)
VNET_DEFINE(int, pf_tcp_iss_off);
#define V_pf_tcp_iss_off VNET(pf_tcp_iss_off)
/*
* Queue for pf_intr() sends.
*/
static MALLOC_DEFINE(M_PFTEMP, "pf_temp", "pf(4) temporary allocations");
struct pf_send_entry {
STAILQ_ENTRY(pf_send_entry) pfse_next;
struct mbuf *pfse_m;
enum {
PFSE_IP,
PFSE_IP6,
PFSE_ICMP,
PFSE_ICMP6,
} pfse_type;
struct {
int type;
int code;
int mtu;
} icmpopts;
};
STAILQ_HEAD(pf_send_head, pf_send_entry);
static VNET_DEFINE(struct pf_send_head, pf_sendqueue);
#define V_pf_sendqueue VNET(pf_sendqueue)
static struct mtx pf_sendqueue_mtx;
#define PF_SENDQ_LOCK() mtx_lock(&pf_sendqueue_mtx)
#define PF_SENDQ_UNLOCK() mtx_unlock(&pf_sendqueue_mtx)
/*
* Queue for pf_overload_task() tasks.
*/
struct pf_overload_entry {
SLIST_ENTRY(pf_overload_entry) next;
struct pf_addr addr;
sa_family_t af;
uint8_t dir;
struct pf_rule *rule;
};
SLIST_HEAD(pf_overload_head, pf_overload_entry);
static VNET_DEFINE(struct pf_overload_head, pf_overloadqueue);
#define V_pf_overloadqueue VNET(pf_overloadqueue)
static VNET_DEFINE(struct task, pf_overloadtask);
#define V_pf_overloadtask VNET(pf_overloadtask)
static struct mtx pf_overloadqueue_mtx;
#define PF_OVERLOADQ_LOCK() mtx_lock(&pf_overloadqueue_mtx)
#define PF_OVERLOADQ_UNLOCK() mtx_unlock(&pf_overloadqueue_mtx)
VNET_DEFINE(struct pf_rulequeue, pf_unlinked_rules);
struct mtx pf_unlnkdrules_mtx;
static VNET_DEFINE(uma_zone_t, pf_sources_z);
#define V_pf_sources_z VNET(pf_sources_z)
uma_zone_t pf_mtag_z;
VNET_DEFINE(uma_zone_t, pf_state_z);
VNET_DEFINE(uma_zone_t, pf_state_key_z);
VNET_DEFINE(uint64_t, pf_stateid[MAXCPU]);
#define PFID_CPUBITS 8
#define PFID_CPUSHIFT (sizeof(uint64_t) * NBBY - PFID_CPUBITS)
#define PFID_CPUMASK ((uint64_t)((1 << PFID_CPUBITS) - 1) << PFID_CPUSHIFT)
#define PFID_MAXID (~PFID_CPUMASK)
CTASSERT((1 << PFID_CPUBITS) >= MAXCPU);
static void pf_src_tree_remove_state(struct pf_state *);
static void pf_init_threshold(struct pf_threshold *, u_int32_t,
u_int32_t);
static void pf_add_threshold(struct pf_threshold *);
static int pf_check_threshold(struct pf_threshold *);
static void pf_change_ap(struct pf_addr *, u_int16_t *,
u_int16_t *, u_int16_t *, struct pf_addr *,
u_int16_t, u_int8_t, sa_family_t);
static int pf_modulate_sack(struct mbuf *, int, struct pf_pdesc *,
struct tcphdr *, struct pf_state_peer *);
static void pf_change_icmp(struct pf_addr *, u_int16_t *,
struct pf_addr *, struct pf_addr *, u_int16_t,
u_int16_t *, u_int16_t *, u_int16_t *,
u_int16_t *, u_int8_t, sa_family_t);
static void pf_send_tcp(struct mbuf *,
const struct pf_rule *, sa_family_t,
const struct pf_addr *, const struct pf_addr *,
u_int16_t, u_int16_t, u_int32_t, u_int32_t,
u_int8_t, u_int16_t, u_int16_t, u_int8_t, int,
u_int16_t, struct ifnet *);
static void pf_send_icmp(struct mbuf *, u_int8_t, u_int8_t,
sa_family_t, struct pf_rule *);
static void pf_detach_state(struct pf_state *);
static int pf_state_key_attach(struct pf_state_key *,
struct pf_state_key *, struct pf_state *);
static void pf_state_key_detach(struct pf_state *, int);
static int pf_state_key_ctor(void *, int, void *, int);
static u_int32_t pf_tcp_iss(struct pf_pdesc *);
static int pf_test_rule(struct pf_rule **, struct pf_state **,
int, struct pfi_kif *, struct mbuf *, int,
struct pf_pdesc *, struct pf_rule **,
struct pf_ruleset **, struct inpcb *);
static int pf_create_state(struct pf_rule *, struct pf_rule *,
struct pf_rule *, struct pf_pdesc *,
struct pf_src_node *, struct pf_state_key *,
struct pf_state_key *, struct mbuf *, int,
u_int16_t, u_int16_t, int *, struct pfi_kif *,
struct pf_state **, int, u_int16_t, u_int16_t,
int);
static int pf_test_fragment(struct pf_rule **, int,
struct pfi_kif *, struct mbuf *, void *,
struct pf_pdesc *, struct pf_rule **,
struct pf_ruleset **);
static int pf_tcp_track_full(struct pf_state_peer *,
struct pf_state_peer *, struct pf_state **,
struct pfi_kif *, struct mbuf *, int,
struct pf_pdesc *, u_short *, int *);
static int pf_tcp_track_sloppy(struct pf_state_peer *,
struct pf_state_peer *, struct pf_state **,
struct pf_pdesc *, u_short *);
static int pf_test_state_tcp(struct pf_state **, int,
struct pfi_kif *, struct mbuf *, int,
void *, struct pf_pdesc *, u_short *);
static int pf_test_state_udp(struct pf_state **, int,
struct pfi_kif *, struct mbuf *, int,
void *, struct pf_pdesc *);
static int pf_test_state_icmp(struct pf_state **, int,
struct pfi_kif *, struct mbuf *, int,
void *, struct pf_pdesc *, u_short *);
static int pf_test_state_other(struct pf_state **, int,
struct pfi_kif *, struct mbuf *, struct pf_pdesc *);
static u_int8_t pf_get_wscale(struct mbuf *, int, u_int16_t,
sa_family_t);
static u_int16_t pf_get_mss(struct mbuf *, int, u_int16_t,
sa_family_t);
static u_int16_t pf_calc_mss(struct pf_addr *, sa_family_t,
int, u_int16_t);
static int pf_check_proto_cksum(struct mbuf *, int, int,
u_int8_t, sa_family_t);
static void pf_print_state_parts(struct pf_state *,
struct pf_state_key *, struct pf_state_key *);
static int pf_addr_wrap_neq(struct pf_addr_wrap *,
struct pf_addr_wrap *);
static struct pf_state *pf_find_state(struct pfi_kif *,
struct pf_state_key_cmp *, u_int);
static int pf_src_connlimit(struct pf_state **);
static void pf_overload_task(void *v, int pending);
static int pf_insert_src_node(struct pf_src_node **,
struct pf_rule *, struct pf_addr *, sa_family_t);
static u_int pf_purge_expired_states(u_int, int);
static void pf_purge_unlinked_rules(void);
static int pf_mtag_uminit(void *, int, int);
static void pf_mtag_free(struct m_tag *);
#ifdef INET
static void pf_route(struct mbuf **, struct pf_rule *, int,
struct ifnet *, struct pf_state *,
struct pf_pdesc *);
#endif /* INET */
#ifdef INET6
static void pf_change_a6(struct pf_addr *, u_int16_t *,
struct pf_addr *, u_int8_t);
static void pf_route6(struct mbuf **, struct pf_rule *, int,
struct ifnet *, struct pf_state *,
struct pf_pdesc *);
#endif /* INET6 */
int in4_cksum(struct mbuf *m, u_int8_t nxt, int off, int len);
VNET_DECLARE(int, pf_end_threads);
VNET_DEFINE(struct pf_limit, pf_limits[PF_LIMIT_MAX]);
#define PACKET_LOOPED(pd) ((pd)->pf_mtag && \
(pd)->pf_mtag->flags & PF_PACKET_LOOPED)
#define STATE_LOOKUP(i, k, d, s, pd) \
do { \
(s) = pf_find_state((i), (k), (d)); \
if ((s) == NULL) \
return (PF_DROP); \
if (PACKET_LOOPED(pd)) \
return (PF_PASS); \
if ((d) == PF_OUT && \
(((s)->rule.ptr->rt == PF_ROUTETO && \
(s)->rule.ptr->direction == PF_OUT) || \
((s)->rule.ptr->rt == PF_REPLYTO && \
(s)->rule.ptr->direction == PF_IN)) && \
(s)->rt_kif != NULL && \
(s)->rt_kif != (i)) \
return (PF_PASS); \
} while (0)
#define BOUND_IFACE(r, k) \
((r)->rule_flag & PFRULE_IFBOUND) ? (k) : V_pfi_all
#define STATE_INC_COUNTERS(s) \
do { \
counter_u64_add(s->rule.ptr->states_cur, 1); \
counter_u64_add(s->rule.ptr->states_tot, 1); \
if (s->anchor.ptr != NULL) { \
counter_u64_add(s->anchor.ptr->states_cur, 1); \
counter_u64_add(s->anchor.ptr->states_tot, 1); \
} \
if (s->nat_rule.ptr != NULL) { \
counter_u64_add(s->nat_rule.ptr->states_cur, 1);\
counter_u64_add(s->nat_rule.ptr->states_tot, 1);\
} \
} while (0)
#define STATE_DEC_COUNTERS(s) \
do { \
if (s->nat_rule.ptr != NULL) \
counter_u64_add(s->nat_rule.ptr->states_cur, -1);\
if (s->anchor.ptr != NULL) \
counter_u64_add(s->anchor.ptr->states_cur, -1); \
counter_u64_add(s->rule.ptr->states_cur, -1); \
} while (0)
static MALLOC_DEFINE(M_PFHASH, "pf_hash", "pf(4) hash header structures");
VNET_DEFINE(struct pf_keyhash *, pf_keyhash);
VNET_DEFINE(struct pf_idhash *, pf_idhash);
VNET_DEFINE(struct pf_srchash *, pf_srchash);
SYSCTL_NODE(_net, OID_AUTO, pf, CTLFLAG_RW, 0, "pf(4)");
u_long pf_hashmask;
u_long pf_srchashmask;
static u_long pf_hashsize;
static u_long pf_srchashsize;
SYSCTL_ULONG(_net_pf, OID_AUTO, states_hashsize, CTLFLAG_RDTUN,
&pf_hashsize, 0, "Size of pf(4) states hashtable");
SYSCTL_ULONG(_net_pf, OID_AUTO, source_nodes_hashsize, CTLFLAG_RDTUN,
&pf_srchashsize, 0, "Size of pf(4) source nodes hashtable");
VNET_DEFINE(void *, pf_swi_cookie);
VNET_DEFINE(uint32_t, pf_hashseed);
#define V_pf_hashseed VNET(pf_hashseed)
int
pf_addr_cmp(struct pf_addr *a, struct pf_addr *b, sa_family_t af)
{
switch (af) {
#ifdef INET
case AF_INET:
if (a->addr32[0] > b->addr32[0])
return (1);
if (a->addr32[0] < b->addr32[0])
return (-1);
break;
#endif /* INET */
#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 */
default:
panic("%s: unknown address family %u", __func__, af);
}
return (0);
}
static __inline uint32_t
pf_hashkey(struct pf_state_key *sk)
{
uint32_t h;
h = murmur3_32_hash32((uint32_t *)sk,
sizeof(struct pf_state_key_cmp)/sizeof(uint32_t),
V_pf_hashseed);
return (h & pf_hashmask);
}
static __inline uint32_t
pf_hashsrc(struct pf_addr *addr, sa_family_t af)
{
uint32_t h;
switch (af) {
case AF_INET:
h = murmur3_32_hash32((uint32_t *)&addr->v4,
sizeof(addr->v4)/sizeof(uint32_t), V_pf_hashseed);
break;
case AF_INET6:
h = murmur3_32_hash32((uint32_t *)&addr->v6,
sizeof(addr->v6)/sizeof(uint32_t), V_pf_hashseed);
break;
default:
panic("%s: unknown address family %u", __func__, af);
}
return (h & pf_srchashmask);
}
#ifdef INET6
void
pf_addrcpy(struct pf_addr *dst, struct pf_addr *src, sa_family_t af)
{
switch (af) {
#ifdef INET
case AF_INET:
dst->addr32[0] = src->addr32[0];
break;
#endif /* INET */
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 */
static 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 = time_uptime;
}
static void
pf_add_threshold(struct pf_threshold *threshold)
{
u_int32_t t = time_uptime, 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;
}
static int
pf_check_threshold(struct pf_threshold *threshold)
{
return (threshold->count > threshold->limit);
}
static int
pf_src_connlimit(struct pf_state **state)
{
struct pf_overload_entry *pfoe;
int bad = 0;
PF_STATE_LOCK_ASSERT(*state);
(*state)->src_node->conn++;
(*state)->src.tcp_est = 1;
pf_add_threshold(&(*state)->src_node->conn_rate);
if ((*state)->rule.ptr->max_src_conn &&
(*state)->rule.ptr->max_src_conn <
(*state)->src_node->conn) {
counter_u64_add(V_pf_status.lcounters[LCNT_SRCCONN], 1);
bad++;
}
if ((*state)->rule.ptr->max_src_conn_rate.limit &&
pf_check_threshold(&(*state)->src_node->conn_rate)) {
counter_u64_add(V_pf_status.lcounters[LCNT_SRCCONNRATE], 1);
bad++;
}
if (!bad)
return (0);
/* Kill this state. */
(*state)->timeout = PFTM_PURGE;
(*state)->src.state = (*state)->dst.state = TCPS_CLOSED;
if ((*state)->rule.ptr->overload_tbl == NULL)
return (1);
/* Schedule overloading and flushing task. */
pfoe = malloc(sizeof(*pfoe), M_PFTEMP, M_NOWAIT);
if (pfoe == NULL)
return (1); /* too bad :( */
bcopy(&(*state)->src_node->addr, &pfoe->addr, sizeof(pfoe->addr));
pfoe->af = (*state)->key[PF_SK_WIRE]->af;
pfoe->rule = (*state)->rule.ptr;
pfoe->dir = (*state)->direction;
PF_OVERLOADQ_LOCK();
SLIST_INSERT_HEAD(&V_pf_overloadqueue, pfoe, next);
PF_OVERLOADQ_UNLOCK();
taskqueue_enqueue(taskqueue_swi, &V_pf_overloadtask);
return (1);
}
static void
pf_overload_task(void *v, int pending)
{
struct pf_overload_head queue;
struct pfr_addr p;
struct pf_overload_entry *pfoe, *pfoe1;
uint32_t killed = 0;
CURVNET_SET((struct vnet *)v);
PF_OVERLOADQ_LOCK();
queue = V_pf_overloadqueue;
SLIST_INIT(&V_pf_overloadqueue);
PF_OVERLOADQ_UNLOCK();
bzero(&p, sizeof(p));
SLIST_FOREACH(pfoe, &queue, next) {
counter_u64_add(V_pf_status.lcounters[LCNT_OVERLOAD_TABLE], 1);
if (V_pf_status.debug >= PF_DEBUG_MISC) {
printf("%s: blocking address ", __func__);
pf_print_host(&pfoe->addr, 0, pfoe->af);
printf("\n");
}
p.pfra_af = pfoe->af;
switch (pfoe->af) {
#ifdef INET
case AF_INET:
p.pfra_net = 32;
p.pfra_ip4addr = pfoe->addr.v4;
break;
#endif
#ifdef INET6
case AF_INET6:
p.pfra_net = 128;
p.pfra_ip6addr = pfoe->addr.v6;
break;
#endif
}
PF_RULES_WLOCK();
pfr_insert_kentry(pfoe->rule->overload_tbl, &p, time_second);
PF_RULES_WUNLOCK();
}
/*
* Remove those entries, that don't need flushing.
*/
SLIST_FOREACH_SAFE(pfoe, &queue, next, pfoe1)
if (pfoe->rule->flush == 0) {
SLIST_REMOVE(&queue, pfoe, pf_overload_entry, next);
free(pfoe, M_PFTEMP);
} else
counter_u64_add(
V_pf_status.lcounters[LCNT_OVERLOAD_FLUSH], 1);
/* If nothing to flush, return. */
if (SLIST_EMPTY(&queue)) {
CURVNET_RESTORE();
return;
}
for (int i = 0; i <= pf_hashmask; i++) {
struct pf_idhash *ih = &V_pf_idhash[i];
struct pf_state_key *sk;
struct pf_state *s;
PF_HASHROW_LOCK(ih);
LIST_FOREACH(s, &ih->states, entry) {
sk = s->key[PF_SK_WIRE];
SLIST_FOREACH(pfoe, &queue, next)
if (sk->af == pfoe->af &&
((pfoe->rule->flush & PF_FLUSH_GLOBAL) ||
pfoe->rule == s->rule.ptr) &&
((pfoe->dir == PF_OUT &&
PF_AEQ(&pfoe->addr, &sk->addr[1], sk->af)) ||
(pfoe->dir == PF_IN &&
PF_AEQ(&pfoe->addr, &sk->addr[0], sk->af)))) {
s->timeout = PFTM_PURGE;
s->src.state = s->dst.state = TCPS_CLOSED;
killed++;
}
}
PF_HASHROW_UNLOCK(ih);
}
SLIST_FOREACH_SAFE(pfoe, &queue, next, pfoe1)
free(pfoe, M_PFTEMP);
if (V_pf_status.debug >= PF_DEBUG_MISC)
printf("%s: %u states killed", __func__, killed);
CURVNET_RESTORE();
}
/*
* Can return locked on failure, so that we can consistently
* allocate and insert a new one.
*/
struct pf_src_node *
pf_find_src_node(struct pf_addr *src, struct pf_rule *rule, sa_family_t af,
int returnlocked)
{
struct pf_srchash *sh;
struct pf_src_node *n;
counter_u64_add(V_pf_status.scounters[SCNT_SRC_NODE_SEARCH], 1);
sh = &V_pf_srchash[pf_hashsrc(src, af)];
PF_HASHROW_LOCK(sh);
LIST_FOREACH(n, &sh->nodes, entry)
if (n->rule.ptr == rule && n->af == af &&
((af == AF_INET && n->addr.v4.s_addr == src->v4.s_addr) ||
(af == AF_INET6 && bcmp(&n->addr, src, sizeof(*src)) == 0)))
break;
if (n != NULL || returnlocked == 0)
PF_HASHROW_UNLOCK(sh);
return (n);
}
static int
pf_insert_src_node(struct pf_src_node **sn, struct pf_rule *rule,
struct pf_addr *src, sa_family_t af)
{
KASSERT((rule->rule_flag & PFRULE_RULESRCTRACK ||
rule->rpool.opts & PF_POOL_STICKYADDR),
("%s for non-tracking rule %p", __func__, rule));
if (*sn == NULL)
*sn = pf_find_src_node(src, rule, af, 1);
if (*sn == NULL) {
struct pf_srchash *sh = &V_pf_srchash[pf_hashsrc(src, af)];
PF_HASHROW_ASSERT(sh);
if (!rule->max_src_nodes ||
counter_u64_fetch(rule->src_nodes) < rule->max_src_nodes)
(*sn) = uma_zalloc(V_pf_sources_z, M_NOWAIT | M_ZERO);
else
counter_u64_add(V_pf_status.lcounters[LCNT_SRCNODES],
1);
if ((*sn) == NULL) {
PF_HASHROW_UNLOCK(sh);
return (-1);
}
pf_init_threshold(&(*sn)->conn_rate,
rule->max_src_conn_rate.limit,
rule->max_src_conn_rate.seconds);
(*sn)->af = af;
(*sn)->rule.ptr = rule;
PF_ACPY(&(*sn)->addr, src, af);
LIST_INSERT_HEAD(&sh->nodes, *sn, entry);
(*sn)->creation = time_uptime;
(*sn)->ruletype = rule->action;
if ((*sn)->rule.ptr != NULL)
counter_u64_add((*sn)->rule.ptr->src_nodes, 1);
PF_HASHROW_UNLOCK(sh);
counter_u64_add(V_pf_status.scounters[SCNT_SRC_NODE_INSERT], 1);
} else {
if (rule->max_src_states &&
(*sn)->states >= rule->max_src_states) {
counter_u64_add(V_pf_status.lcounters[LCNT_SRCSTATES],
1);
return (-1);
}
}
return (0);
}
void
pf_unlink_src_node_locked(struct pf_src_node *src)
{
#ifdef INVARIANTS
struct pf_srchash *sh;
sh = &V_pf_srchash[pf_hashsrc(&src->addr, src->af)];
PF_HASHROW_ASSERT(sh);
#endif
LIST_REMOVE(src, entry);
if (src->rule.ptr)
counter_u64_add(src->rule.ptr->src_nodes, -1);
counter_u64_add(V_pf_status.scounters[SCNT_SRC_NODE_REMOVALS], 1);
}
void
pf_unlink_src_node(struct pf_src_node *src)
{
struct pf_srchash *sh;
sh = &V_pf_srchash[pf_hashsrc(&src->addr, src->af)];
PF_HASHROW_LOCK(sh);
pf_unlink_src_node_locked(src);
PF_HASHROW_UNLOCK(sh);
}
static void
pf_free_src_node(struct pf_src_node *sn)
{
KASSERT(sn->states == 0, ("%s: %p has refs", __func__, sn));
uma_zfree(V_pf_sources_z, sn);
}
u_int
pf_free_src_nodes(struct pf_src_node_list *head)
{
struct pf_src_node *sn, *tmp;
u_int count = 0;
LIST_FOREACH_SAFE(sn, head, entry, tmp) {
pf_free_src_node(sn);
count++;
}
return (count);
}
void
pf_mtag_initialize()
{
pf_mtag_z = uma_zcreate("pf mtags", sizeof(struct m_tag) +
sizeof(struct pf_mtag), NULL, NULL, pf_mtag_uminit, NULL,
UMA_ALIGN_PTR, 0);
}
/* Per-vnet data storage structures initialization. */
void
pf_initialize()
{
struct pf_keyhash *kh;
struct pf_idhash *ih;
struct pf_srchash *sh;
u_int i;
if (pf_hashsize == 0 || !powerof2(pf_hashsize))
pf_hashsize = PF_HASHSIZ;
if (pf_srchashsize == 0 || !powerof2(pf_srchashsize))
pf_srchashsize = PF_HASHSIZ / 4;
V_pf_hashseed = arc4random();
/* States and state keys storage. */
V_pf_state_z = uma_zcreate("pf states", sizeof(struct pf_state),
NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
V_pf_limits[PF_LIMIT_STATES].zone = V_pf_state_z;
uma_zone_set_max(V_pf_state_z, PFSTATE_HIWAT);
uma_zone_set_warning(V_pf_state_z, "PF states limit reached");
V_pf_state_key_z = uma_zcreate("pf state keys",
sizeof(struct pf_state_key), pf_state_key_ctor, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
V_pf_keyhash = malloc(pf_hashsize * sizeof(struct pf_keyhash),
M_PFHASH, M_WAITOK | M_ZERO);
V_pf_idhash = malloc(pf_hashsize * sizeof(struct pf_idhash),
M_PFHASH, M_WAITOK | M_ZERO);
pf_hashmask = pf_hashsize - 1;
for (i = 0, kh = V_pf_keyhash, ih = V_pf_idhash; i <= pf_hashmask;
i++, kh++, ih++) {
mtx_init(&kh->lock, "pf_keyhash", NULL, MTX_DEF | MTX_DUPOK);
mtx_init(&ih->lock, "pf_idhash", NULL, MTX_DEF);
}
/* Source nodes. */
V_pf_sources_z = uma_zcreate("pf source nodes",
sizeof(struct pf_src_node), NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
0);
V_pf_limits[PF_LIMIT_SRC_NODES].zone = V_pf_sources_z;
uma_zone_set_max(V_pf_sources_z, PFSNODE_HIWAT);
uma_zone_set_warning(V_pf_sources_z, "PF source nodes limit reached");
V_pf_srchash = malloc(pf_srchashsize * sizeof(struct pf_srchash),
M_PFHASH, M_WAITOK|M_ZERO);
pf_srchashmask = pf_srchashsize - 1;
for (i = 0, sh = V_pf_srchash; i <= pf_srchashmask; i++, sh++)
mtx_init(&sh->lock, "pf_srchash", NULL, MTX_DEF);
/* ALTQ */
TAILQ_INIT(&V_pf_altqs[0]);
TAILQ_INIT(&V_pf_altqs[1]);
TAILQ_INIT(&V_pf_pabuf);
V_pf_altqs_active = &V_pf_altqs[0];
V_pf_altqs_inactive = &V_pf_altqs[1];
/* Send & overload+flush queues. */
STAILQ_INIT(&V_pf_sendqueue);
SLIST_INIT(&V_pf_overloadqueue);
TASK_INIT(&V_pf_overloadtask, 0, pf_overload_task, curvnet);
mtx_init(&pf_sendqueue_mtx, "pf send queue", NULL, MTX_DEF);
mtx_init(&pf_overloadqueue_mtx, "pf overload/flush queue", NULL,
MTX_DEF);
/* Unlinked, but may be referenced rules. */
TAILQ_INIT(&V_pf_unlinked_rules);
mtx_init(&pf_unlnkdrules_mtx, "pf unlinked rules", NULL, MTX_DEF);
}
void
pf_mtag_cleanup()
{
uma_zdestroy(pf_mtag_z);
}
void
pf_cleanup()
{
struct pf_keyhash *kh;
struct pf_idhash *ih;
struct pf_srchash *sh;
struct pf_send_entry *pfse, *next;
u_int i;
for (i = 0, kh = V_pf_keyhash, ih = V_pf_idhash; i <= pf_hashmask;
i++, kh++, ih++) {
KASSERT(LIST_EMPTY(&kh->keys), ("%s: key hash not empty",
__func__));
KASSERT(LIST_EMPTY(&ih->states), ("%s: id hash not empty",
__func__));
mtx_destroy(&kh->lock);
mtx_destroy(&ih->lock);
}
free(V_pf_keyhash, M_PFHASH);
free(V_pf_idhash, M_PFHASH);
for (i = 0, sh = V_pf_srchash; i <= pf_srchashmask; i++, sh++) {
KASSERT(LIST_EMPTY(&sh->nodes),
("%s: source node hash not empty", __func__));
mtx_destroy(&sh->lock);
}
free(V_pf_srchash, M_PFHASH);
STAILQ_FOREACH_SAFE(pfse, &V_pf_sendqueue, pfse_next, next) {
m_freem(pfse->pfse_m);
free(pfse, M_PFTEMP);
}
mtx_destroy(&pf_sendqueue_mtx);
mtx_destroy(&pf_overloadqueue_mtx);
mtx_destroy(&pf_unlnkdrules_mtx);
uma_zdestroy(V_pf_sources_z);
uma_zdestroy(V_pf_state_z);
uma_zdestroy(V_pf_state_key_z);
}
static int
pf_mtag_uminit(void *mem, int size, int how)
{
struct m_tag *t;
t = (struct m_tag *)mem;
t->m_tag_cookie = MTAG_ABI_COMPAT;
t->m_tag_id = PACKET_TAG_PF;
t->m_tag_len = sizeof(struct pf_mtag);
t->m_tag_free = pf_mtag_free;
return (0);
}
static void
pf_mtag_free(struct m_tag *t)
{
uma_zfree(pf_mtag_z, t);
}
struct pf_mtag *
pf_get_mtag(struct mbuf *m)
{
struct m_tag *mtag;
if ((mtag = m_tag_find(m, PACKET_TAG_PF, NULL)) != NULL)
return ((struct pf_mtag *)(mtag + 1));
mtag = uma_zalloc(pf_mtag_z, M_NOWAIT);
if (mtag == NULL)
return (NULL);
bzero(mtag + 1, sizeof(struct pf_mtag));
m_tag_prepend(m, mtag);
return ((struct pf_mtag *)(mtag + 1));
}
static int
pf_state_key_attach(struct pf_state_key *skw, struct pf_state_key *sks,
struct pf_state *s)
{
struct pf_keyhash *khs, *khw, *kh;
struct pf_state_key *sk, *cur;
struct pf_state *si, *olds = NULL;
int idx;
KASSERT(s->refs == 0, ("%s: state not pristine", __func__));
KASSERT(s->key[PF_SK_WIRE] == NULL, ("%s: state has key", __func__));
KASSERT(s->key[PF_SK_STACK] == NULL, ("%s: state has key", __func__));
/*
* We need to lock hash slots of both keys. To avoid deadlock
* we always lock the slot with lower address first. Unlock order
* isn't important.
*
* We also need to lock ID hash slot before dropping key
* locks. On success we return with ID hash slot locked.
*/
if (skw == sks) {
khs = khw = &V_pf_keyhash[pf_hashkey(skw)];
PF_HASHROW_LOCK(khs);
} else {
khs = &V_pf_keyhash[pf_hashkey(sks)];
khw = &V_pf_keyhash[pf_hashkey(skw)];
if (khs == khw) {
PF_HASHROW_LOCK(khs);
} else if (khs < khw) {
PF_HASHROW_LOCK(khs);
PF_HASHROW_LOCK(khw);
} else {
PF_HASHROW_LOCK(khw);
PF_HASHROW_LOCK(khs);
}
}
#define KEYS_UNLOCK() do { \
if (khs != khw) { \
PF_HASHROW_UNLOCK(khs); \
PF_HASHROW_UNLOCK(khw); \
} else \
PF_HASHROW_UNLOCK(khs); \
} while (0)
/*
* First run: start with wire key.
*/
sk = skw;
kh = khw;
idx = PF_SK_WIRE;
keyattach:
LIST_FOREACH(cur, &kh->keys, entry)
if (bcmp(cur, sk, sizeof(struct pf_state_key_cmp)) == 0)
break;
if (cur != NULL) {
/* Key exists. Check for same kif, if none, add to key. */
TAILQ_FOREACH(si, &cur->states[idx], key_list[idx]) {
struct pf_idhash *ih = &V_pf_idhash[PF_IDHASH(si)];
PF_HASHROW_LOCK(ih);
if (si->kif == s->kif &&
si->direction == s->direction) {
if (sk->proto == IPPROTO_TCP &&
si->src.state >= TCPS_FIN_WAIT_2 &&
si->dst.state >= TCPS_FIN_WAIT_2) {
/*
* New state matches an old >FIN_WAIT_2
* state. We can't drop key hash locks,
* thus we can't unlink it properly.
*
* As a workaround we drop it into
* TCPS_CLOSED state, schedule purge
* ASAP and push it into the very end
* of the slot TAILQ, so that it won't
* conflict with our new state.
*/
si->src.state = si->dst.state =
TCPS_CLOSED;
si->timeout = PFTM_PURGE;
olds = si;
} else {
if (V_pf_status.debug >= PF_DEBUG_MISC) {
printf("pf: %s key attach "
"failed on %s: ",
(idx == PF_SK_WIRE) ?
"wire" : "stack",
s->kif->pfik_name);
pf_print_state_parts(s,
(idx == PF_SK_WIRE) ?
sk : NULL,
(idx == PF_SK_STACK) ?
sk : NULL);
printf(", existing: ");
pf_print_state_parts(si,
(idx == PF_SK_WIRE) ?
sk : NULL,
(idx == PF_SK_STACK) ?
sk : NULL);
printf("\n");
}
PF_HASHROW_UNLOCK(ih);
KEYS_UNLOCK();
uma_zfree(V_pf_state_key_z, sk);
if (idx == PF_SK_STACK)
pf_detach_state(s);
return (EEXIST); /* collision! */
}
}
PF_HASHROW_UNLOCK(ih);
}
uma_zfree(V_pf_state_key_z, sk);
s->key[idx] = cur;
} else {
LIST_INSERT_HEAD(&kh->keys, sk, entry);
s->key[idx] = sk;
}
stateattach:
/* List is sorted, if-bound states before floating. */
if (s->kif == V_pfi_all)
TAILQ_INSERT_TAIL(&s->key[idx]->states[idx], s, key_list[idx]);
else
TAILQ_INSERT_HEAD(&s->key[idx]->states[idx], s, key_list[idx]);
if (olds) {
TAILQ_REMOVE(&s->key[idx]->states[idx], olds, key_list[idx]);
TAILQ_INSERT_TAIL(&s->key[idx]->states[idx], olds,
key_list[idx]);
olds = NULL;
}
/*
* Attach done. See how should we (or should not?)
* attach a second key.
*/
if (sks == skw) {
s->key[PF_SK_STACK] = s->key[PF_SK_WIRE];
idx = PF_SK_STACK;
sks = NULL;
goto stateattach;
} else if (sks != NULL) {
/*
* Continue attaching with stack key.
*/
sk = sks;
kh = khs;
idx = PF_SK_STACK;
sks = NULL;
goto keyattach;
}
PF_STATE_LOCK(s);
KEYS_UNLOCK();
KASSERT(s->key[PF_SK_WIRE] != NULL && s->key[PF_SK_STACK] != NULL,
("%s failure", __func__));
return (0);
#undef KEYS_UNLOCK
}
static void
pf_detach_state(struct pf_state *s)
{
struct pf_state_key *sks = s->key[PF_SK_STACK];
struct pf_keyhash *kh;
if (sks != NULL) {
kh = &V_pf_keyhash[pf_hashkey(sks)];
PF_HASHROW_LOCK(kh);
if (s->key[PF_SK_STACK] != NULL)
pf_state_key_detach(s, PF_SK_STACK);
/*
* If both point to same key, then we are done.
*/
if (sks == s->key[PF_SK_WIRE]) {
pf_state_key_detach(s, PF_SK_WIRE);
PF_HASHROW_UNLOCK(kh);
return;
}
PF_HASHROW_UNLOCK(kh);
}
if (s->key[PF_SK_WIRE] != NULL) {
kh = &V_pf_keyhash[pf_hashkey(s->key[PF_SK_WIRE])];
PF_HASHROW_LOCK(kh);
if (s->key[PF_SK_WIRE] != NULL)
pf_state_key_detach(s, PF_SK_WIRE);
PF_HASHROW_UNLOCK(kh);
}
}
static void
pf_state_key_detach(struct pf_state *s, int idx)
{
struct pf_state_key *sk = s->key[idx];
#ifdef INVARIANTS
struct pf_keyhash *kh = &V_pf_keyhash[pf_hashkey(sk)];
PF_HASHROW_ASSERT(kh);
#endif
TAILQ_REMOVE(&sk->states[idx], s, key_list[idx]);
s->key[idx] = NULL;
if (TAILQ_EMPTY(&sk->states[0]) && TAILQ_EMPTY(&sk->states[1])) {
LIST_REMOVE(sk, entry);
uma_zfree(V_pf_state_key_z, sk);
}
}
static int
pf_state_key_ctor(void *mem, int size, void *arg, int flags)
{
struct pf_state_key *sk = mem;
bzero(sk, sizeof(struct pf_state_key_cmp));
TAILQ_INIT(&sk->states[PF_SK_WIRE]);
TAILQ_INIT(&sk->states[PF_SK_STACK]);
return (0);
}
struct pf_state_key *
pf_state_key_setup(struct pf_pdesc *pd, struct pf_addr *saddr,
struct pf_addr *daddr, u_int16_t sport, u_int16_t dport)
{
struct pf_state_key *sk;
sk = uma_zalloc(V_pf_state_key_z, M_NOWAIT);
if (sk == NULL)
return (NULL);
PF_ACPY(&sk->addr[pd->sidx], saddr, pd->af);
PF_ACPY(&sk->addr[pd->didx], daddr, pd->af);
sk->port[pd->sidx] = sport;
sk->port[pd->didx] = dport;
sk->proto = pd->proto;
sk->af = pd->af;
return (sk);
}
struct pf_state_key *
pf_state_key_clone(struct pf_state_key *orig)
{
struct pf_state_key *sk;
sk = uma_zalloc(V_pf_state_key_z, M_NOWAIT);
if (sk == NULL)
return (NULL);
bcopy(orig, sk, sizeof(struct pf_state_key_cmp));
return (sk);
}
int
pf_state_insert(struct pfi_kif *kif, struct pf_state_key *skw,
struct pf_state_key *sks, struct pf_state *s)
{
struct pf_idhash *ih;
struct pf_state *cur;
int error;
KASSERT(TAILQ_EMPTY(&sks->states[0]) && TAILQ_EMPTY(&sks->states[1]),
("%s: sks not pristine", __func__));
KASSERT(TAILQ_EMPTY(&skw->states[0]) && TAILQ_EMPTY(&skw->states[1]),
("%s: skw not pristine", __func__));
KASSERT(s->refs == 0, ("%s: state not pristine", __func__));
s->kif = kif;
if (s->id == 0 && s->creatorid == 0) {
/* XXX: should be atomic, but probability of collision low */
if ((s->id = V_pf_stateid[curcpu]++) == PFID_MAXID)
V_pf_stateid[curcpu] = 1;
s->id |= (uint64_t )curcpu << PFID_CPUSHIFT;
s->id = htobe64(s->id);
s->creatorid = V_pf_status.hostid;
}
/* Returns with ID locked on success. */
if ((error = pf_state_key_attach(skw, sks, s)) != 0)
return (error);
ih = &V_pf_idhash[PF_IDHASH(s)];
PF_HASHROW_ASSERT(ih);
LIST_FOREACH(cur, &ih->states, entry)
if (cur->id == s->id && cur->creatorid == s->creatorid)
break;
if (cur != NULL) {
PF_HASHROW_UNLOCK(ih);
if (V_pf_status.debug >= PF_DEBUG_MISC) {
printf("pf: state ID collision: "
"id: %016llx creatorid: %08x\n",
(unsigned long long)be64toh(s->id),
ntohl(s->creatorid));
}
pf_detach_state(s);
return (EEXIST);
}
LIST_INSERT_HEAD(&ih->states, s, entry);
/* One for keys, one for ID hash. */
refcount_init(&s->refs, 2);
counter_u64_add(V_pf_status.fcounters[FCNT_STATE_INSERT], 1);
if (pfsync_insert_state_ptr != NULL)
pfsync_insert_state_ptr(s);
/* Returns locked. */
return (0);
}
/*
* Find state by ID: returns with locked row on success.
*/
struct pf_state *
pf_find_state_byid(uint64_t id, uint32_t creatorid)
{
struct pf_idhash *ih;
struct pf_state *s;
counter_u64_add(V_pf_status.fcounters[FCNT_STATE_SEARCH], 1);
ih = &V_pf_idhash[(be64toh(id) % (pf_hashmask + 1))];
PF_HASHROW_LOCK(ih);
LIST_FOREACH(s, &ih->states, entry)
if (s->id == id && s->creatorid == creatorid)
break;
if (s == NULL)
PF_HASHROW_UNLOCK(ih);
return (s);
}
/*
* Find state by key.
* Returns with ID hash slot locked on success.
*/
static struct pf_state *
pf_find_state(struct pfi_kif *kif, struct pf_state_key_cmp *key, u_int dir)
{
struct pf_keyhash *kh;
struct pf_state_key *sk;
struct pf_state *s;
int idx;
counter_u64_add(V_pf_status.fcounters[FCNT_STATE_SEARCH], 1);
kh = &V_pf_keyhash[pf_hashkey((struct pf_state_key *)key)];
PF_HASHROW_LOCK(kh);
LIST_FOREACH(sk, &kh->keys, entry)
if (bcmp(sk, key, sizeof(struct pf_state_key_cmp)) == 0)
break;
if (sk == NULL) {
PF_HASHROW_UNLOCK(kh);
return (NULL);
}
idx = (dir == PF_IN ? PF_SK_WIRE : PF_SK_STACK);
/* List is sorted, if-bound states before floating ones. */
TAILQ_FOREACH(s, &sk->states[idx], key_list[idx])
if (s->kif == V_pfi_all || s->kif == kif) {
PF_STATE_LOCK(s);
PF_HASHROW_UNLOCK(kh);
if (s->timeout >= PFTM_MAX) {
/*
* State is either being processed by
* pf_unlink_state() in an other thread, or
* is scheduled for immediate expiry.
*/
PF_STATE_UNLOCK(s);
return (NULL);
}
return (s);
}
PF_HASHROW_UNLOCK(kh);
return (NULL);
}
struct pf_state *
pf_find_state_all(struct pf_state_key_cmp *key, u_int dir, int *more)
{
struct pf_keyhash *kh;
struct pf_state_key *sk;
struct pf_state *s, *ret = NULL;
int idx, inout = 0;
counter_u64_add(V_pf_status.fcounters[FCNT_STATE_SEARCH], 1);
kh = &V_pf_keyhash[pf_hashkey((struct pf_state_key *)key)];
PF_HASHROW_LOCK(kh);
LIST_FOREACH(sk, &kh->keys, entry)
if (bcmp(sk, key, sizeof(struct pf_state_key_cmp)) == 0)
break;
if (sk == NULL) {
PF_HASHROW_UNLOCK(kh);
return (NULL);
}
switch (dir) {
case PF_IN:
idx = PF_SK_WIRE;
break;
case PF_OUT:
idx = PF_SK_STACK;
break;
case PF_INOUT:
idx = PF_SK_WIRE;
inout = 1;
break;
default:
panic("%s: dir %u", __func__, dir);
}
second_run:
TAILQ_FOREACH(s, &sk->states[idx], key_list[idx]) {
if (more == NULL) {
PF_HASHROW_UNLOCK(kh);
return (s);
}
if (ret)
(*more)++;
else
ret = s;
}
if (inout == 1) {
inout = 0;
idx = PF_SK_STACK;
goto second_run;
}
PF_HASHROW_UNLOCK(kh);
return (ret);
}
/* END state table stuff */
static void
pf_send(struct pf_send_entry *pfse)
{
PF_SENDQ_LOCK();
STAILQ_INSERT_TAIL(&V_pf_sendqueue, pfse, pfse_next);
PF_SENDQ_UNLOCK();
swi_sched(V_pf_swi_cookie, 0);
}
void
pf_intr(void *v)
{
struct pf_send_head queue;
struct pf_send_entry *pfse, *next;
CURVNET_SET((struct vnet *)v);
PF_SENDQ_LOCK();
queue = V_pf_sendqueue;
STAILQ_INIT(&V_pf_sendqueue);
PF_SENDQ_UNLOCK();
STAILQ_FOREACH_SAFE(pfse, &queue, pfse_next, next) {
switch (pfse->pfse_type) {
#ifdef INET
case PFSE_IP:
ip_output(pfse->pfse_m, NULL, NULL, 0, NULL, NULL);
break;
case PFSE_ICMP:
icmp_error(pfse->pfse_m, pfse->icmpopts.type,
pfse->icmpopts.code, 0, pfse->icmpopts.mtu);
break;
#endif /* INET */
#ifdef INET6
case PFSE_IP6:
ip6_output(pfse->pfse_m, NULL, NULL, 0, NULL, NULL,
NULL);
break;
case PFSE_ICMP6:
icmp6_error(pfse->pfse_m, pfse->icmpopts.type,
pfse->icmpopts.code, pfse->icmpopts.mtu);
break;
#endif /* INET6 */
default:
panic("%s: unknown type", __func__);
}
free(pfse, M_PFTEMP);
}
CURVNET_RESTORE();
}
void
pf_purge_thread(void *v)
{
u_int idx = 0;
CURVNET_SET((struct vnet *)v);
for (;;) {
PF_RULES_RLOCK();
rw_sleep(pf_purge_thread, &pf_rules_lock, 0, "pftm", hz / 10);
if (V_pf_end_threads) {
/*
* To cleanse up all kifs and rules we need
* two runs: first one clears reference flags,
* then pf_purge_expired_states() doesn't
* raise them, and then second run frees.
*/
PF_RULES_RUNLOCK();
pf_purge_unlinked_rules();
pfi_kif_purge();
/*
* Now purge everything.
*/
pf_purge_expired_states(0, pf_hashmask);
pf_purge_expired_fragments();
pf_purge_expired_src_nodes();
/*
* Now all kifs & rules should be unreferenced,
* thus should be successfully freed.
*/
pf_purge_unlinked_rules();
pfi_kif_purge();
/*
* Announce success and exit.
*/
PF_RULES_RLOCK();
V_pf_end_threads++;
PF_RULES_RUNLOCK();
wakeup(pf_purge_thread);
kproc_exit(0);
}
PF_RULES_RUNLOCK();
/* Process 1/interval fraction of the state table every run. */
idx = pf_purge_expired_states(idx, pf_hashmask /
(V_pf_default_rule.timeout[PFTM_INTERVAL] * 10));
/* Purge other expired types every PFTM_INTERVAL seconds. */
if (idx == 0) {
/*
* Order is important:
* - states and src nodes reference rules
* - states and rules reference kifs
*/
pf_purge_expired_fragments();
pf_purge_expired_src_nodes();
pf_purge_unlinked_rules();
pfi_kif_purge();
}
}
/* not reached */
CURVNET_RESTORE();
}
u_int32_t
pf_state_expires(const struct pf_state *state)
{
u_int32_t timeout;
u_int32_t start;
u_int32_t end;
u_int32_t states;
/* handle all PFTM_* > PFTM_MAX here */
if (state->timeout == PFTM_PURGE)
return (time_uptime);
KASSERT(state->timeout != PFTM_UNLINKED,
("pf_state_expires: timeout == PFTM_UNLINKED"));
KASSERT((state->timeout < PFTM_MAX),
("pf_state_expires: timeout > PFTM_MAX"));
timeout = state->rule.ptr->timeout[state->timeout];
if (!timeout)
timeout = V_pf_default_rule.timeout[state->timeout];
start = state->rule.ptr->timeout[PFTM_ADAPTIVE_START];
if (start) {
end = state->rule.ptr->timeout[PFTM_ADAPTIVE_END];
states = counter_u64_fetch(state->rule.ptr->states_cur);
} else {
start = V_pf_default_rule.timeout[PFTM_ADAPTIVE_START];
end = V_pf_default_rule.timeout[PFTM_ADAPTIVE_END];
states = V_pf_status.states;
}
if (end && states > start && start < end) {
if (states < end)
return (state->expire + timeout * (end - states) /
(end - start));
else
return (time_uptime);
}
return (state->expire + timeout);
}
void
pf_purge_expired_src_nodes()
{
struct pf_src_node_list freelist;
struct pf_srchash *sh;
struct pf_src_node *cur, *next;
int i;
LIST_INIT(&freelist);
for (i = 0, sh = V_pf_srchash; i <= pf_srchashmask; i++, sh++) {
PF_HASHROW_LOCK(sh);
LIST_FOREACH_SAFE(cur, &sh->nodes, entry, next)
if (cur->states == 0 && cur->expire <= time_uptime) {
pf_unlink_src_node_locked(cur);
LIST_INSERT_HEAD(&freelist, cur, entry);
} else if (cur->rule.ptr != NULL)
cur->rule.ptr->rule_flag |= PFRULE_REFS;
PF_HASHROW_UNLOCK(sh);
}
pf_free_src_nodes(&freelist);
V_pf_status.src_nodes = uma_zone_get_cur(V_pf_sources_z);
}
static void
pf_src_tree_remove_state(struct pf_state *s)
{
u_int32_t timeout;
if (s->src_node != NULL) {
if (s->src.tcp_est)
--s->src_node->conn;
if (--s->src_node->states == 0) {
timeout = s->rule.ptr->timeout[PFTM_SRC_NODE];
if (!timeout)
timeout =
V_pf_default_rule.timeout[PFTM_SRC_NODE];
s->src_node->expire = time_uptime + timeout;
}
}
if (s->nat_src_node != s->src_node && s->nat_src_node != NULL) {
if (--s->nat_src_node->states == 0) {
timeout = s->rule.ptr->timeout[PFTM_SRC_NODE];
if (!timeout)
timeout =
V_pf_default_rule.timeout[PFTM_SRC_NODE];
s->nat_src_node->expire = time_uptime + timeout;
}
}
s->src_node = s->nat_src_node = NULL;
}
/*
* Unlink and potentilly free a state. Function may be
* called with ID hash row locked, but always returns
* unlocked, since it needs to go through key hash locking.
*/
int
pf_unlink_state(struct pf_state *s, u_int flags)
{
struct pf_idhash *ih = &V_pf_idhash[PF_IDHASH(s)];
if ((flags & PF_ENTER_LOCKED) == 0)
PF_HASHROW_LOCK(ih);
else
PF_HASHROW_ASSERT(ih);
if (s->timeout == PFTM_UNLINKED) {
/*
* State is being processed
* by pf_unlink_state() in
* an other thread.
*/
PF_HASHROW_UNLOCK(ih);
return (0); /* XXXGL: undefined actually */
}
if (s->src.state == PF_TCPS_PROXY_DST) {
/* XXX wire key the right one? */
pf_send_tcp(NULL, s->rule.ptr, s->key[PF_SK_WIRE]->af,
&s->key[PF_SK_WIRE]->addr[1],
&s->key[PF_SK_WIRE]->addr[0],
s->key[PF_SK_WIRE]->port[1],
s->key[PF_SK_WIRE]->port[0],
s->src.seqhi, s->src.seqlo + 1,
TH_RST|TH_ACK, 0, 0, 0, 1, s->tag, NULL);
}
LIST_REMOVE(s, entry);
pf_src_tree_remove_state(s);
if (pfsync_delete_state_ptr != NULL)
pfsync_delete_state_ptr(s);
STATE_DEC_COUNTERS(s);
s->timeout = PFTM_UNLINKED;
PF_HASHROW_UNLOCK(ih);
pf_detach_state(s);
refcount_release(&s->refs);
return (pf_release_state(s));
}
void
pf_free_state(struct pf_state *cur)
{
KASSERT(cur->refs == 0, ("%s: %p has refs", __func__, cur));
KASSERT(cur->timeout == PFTM_UNLINKED, ("%s: timeout %u", __func__,
cur->timeout));
pf_normalize_tcp_cleanup(cur);
uma_zfree(V_pf_state_z, cur);
counter_u64_add(V_pf_status.fcounters[FCNT_STATE_REMOVALS], 1);
}
/*
* Called only from pf_purge_thread(), thus serialized.
*/
static u_int
pf_purge_expired_states(u_int i, int maxcheck)
{
struct pf_idhash *ih;
struct pf_state *s;
V_pf_status.states = uma_zone_get_cur(V_pf_state_z);
/*
* Go through hash and unlink states that expire now.
*/
while (maxcheck > 0) {
ih = &V_pf_idhash[i];
relock:
PF_HASHROW_LOCK(ih);
LIST_FOREACH(s, &ih->states, entry) {
if (pf_state_expires(s) <= time_uptime) {
V_pf_status.states -=
pf_unlink_state(s, PF_ENTER_LOCKED);
goto relock;
}
s->rule.ptr->rule_flag |= PFRULE_REFS;
if (s->nat_rule.ptr != NULL)
s->nat_rule.ptr->rule_flag |= PFRULE_REFS;
if (s->anchor.ptr != NULL)
s->anchor.ptr->rule_flag |= PFRULE_REFS;
s->kif->pfik_flags |= PFI_IFLAG_REFS;
if (s->rt_kif)
s->rt_kif->pfik_flags |= PFI_IFLAG_REFS;
}
PF_HASHROW_UNLOCK(ih);
/* Return when we hit end of hash. */
if (++i > pf_hashmask) {
V_pf_status.states = uma_zone_get_cur(V_pf_state_z);
return (0);
}
maxcheck--;
}
V_pf_status.states = uma_zone_get_cur(V_pf_state_z);
return (i);
}
static void
pf_purge_unlinked_rules()
{
struct pf_rulequeue tmpq;
struct pf_rule *r, *r1;
/*
* If we have overloading task pending, then we'd
* better skip purging this time. There is a tiny
* probability that overloading task references
* an already unlinked rule.
*/
PF_OVERLOADQ_LOCK();
if (!SLIST_EMPTY(&V_pf_overloadqueue)) {
PF_OVERLOADQ_UNLOCK();
return;
}
PF_OVERLOADQ_UNLOCK();
/*
* Do naive mark-and-sweep garbage collecting of old rules.
* Reference flag is raised by pf_purge_expired_states()
* and pf_purge_expired_src_nodes().
*
* To avoid LOR between PF_UNLNKDRULES_LOCK/PF_RULES_WLOCK,
* use a temporary queue.
*/
TAILQ_INIT(&tmpq);
PF_UNLNKDRULES_LOCK();
TAILQ_FOREACH_SAFE(r, &V_pf_unlinked_rules, entries, r1) {
if (!(r->rule_flag & PFRULE_REFS)) {
TAILQ_REMOVE(&V_pf_unlinked_rules, r, entries);
TAILQ_INSERT_TAIL(&tmpq, r, entries);
} else
r->rule_flag &= ~PFRULE_REFS;
}
PF_UNLNKDRULES_UNLOCK();
if (!TAILQ_EMPTY(&tmpq)) {
PF_RULES_WLOCK();
TAILQ_FOREACH_SAFE(r, &tmpq, entries, r1) {
TAILQ_REMOVE(&tmpq, r, entries);
pf_free_rule(r);
}
PF_RULES_WUNLOCK();
}
}
void
pf_print_host(struct pf_addr *addr, u_int16_t p, sa_family_t af)
{
switch (af) {
#ifdef INET
case AF_INET: {
u_int32_t a = ntohl(addr->addr32[0]);
printf("%u.%u.%u.%u", (a>>24)&255, (a>>16)&255,
(a>>8)&255, a&255);
if (p) {
p = ntohs(p);
printf(":%u", p);
}
break;
}
#endif /* INET */
#ifdef INET6
case AF_INET6: {
u_int16_t b;
u_int8_t i, curstart, curend, maxstart, maxend;
curstart = curend = maxstart = maxend = 255;
for (i = 0; i < 8; i++) {
if (!addr->addr16[i]) {
if (curstart == 255)
curstart = i;
curend = i;
} else {
if ((curend - curstart) >
(maxend - maxstart)) {
maxstart = curstart;
maxend = curend;
}
curstart = curend = 255;
}
}
if ((curend - curstart) >
(maxend - maxstart)) {
maxstart = curstart;
maxend = curend;
}
for (i = 0; i < 8; i++) {
if (i >= maxstart && i <= maxend) {
if (i == 0)
printf(":");
if (i == maxend)
printf(":");
} else {
b = ntohs(addr->addr16[i]);
printf("%x", b);
if (i < 7)
printf(":");
}
}
if (p) {
p = ntohs(p);
printf("[%u]", p);
}
break;
}
#endif /* INET6 */
}
}
void
pf_print_state(struct pf_state *s)
{
pf_print_state_parts(s, NULL, NULL);
}
static void
pf_print_state_parts(struct pf_state *s,
struct pf_state_key *skwp, struct pf_state_key *sksp)
{
struct pf_state_key *skw, *sks;
u_int8_t proto, dir;
/* Do our best to fill these, but they're skipped if NULL */
skw = skwp ? skwp : (s ? s->key[PF_SK_WIRE] : NULL);
sks = sksp ? sksp : (s ? s->key[PF_SK_STACK] : NULL);
proto = skw ? skw->proto : (sks ? sks->proto : 0);
dir = s ? s->direction : 0;
switch (proto) {
case IPPROTO_IPV4:
printf("IPv4");
break;
case IPPROTO_IPV6:
printf("IPv6");
break;
case IPPROTO_TCP:
printf("TCP");
break;
case IPPROTO_UDP:
printf("UDP");
break;
case IPPROTO_ICMP:
printf("ICMP");
break;
case IPPROTO_ICMPV6:
printf("ICMPv6");
break;
default:
printf("%u", skw->proto);
break;
}
switch (dir) {
case PF_IN:
printf(" in");
break;
case PF_OUT:
printf(" out");
break;
}
if (skw) {
printf(" wire: ");
pf_print_host(&skw->addr[0], skw->port[0], skw->af);
printf(" ");
pf_print_host(&skw->addr[1], skw->port[1], skw->af);
}
if (sks) {
printf(" stack: ");
if (sks != skw) {
pf_print_host(&sks->addr[0], sks->port[0], sks->af);
printf(" ");
pf_print_host(&sks->addr[1], sks->port[1], sks->af);
} else
printf("-");
}
if (s) {
if (proto == IPPROTO_TCP) {
printf(" [lo=%u high=%u win=%u modulator=%u",
s->src.seqlo, s->src.seqhi,
s->src.max_win, s->src.seqdiff);
if (s->src.wscale && s->dst.wscale)
printf(" wscale=%u",
s->src.wscale & PF_WSCALE_MASK);
printf("]");
printf(" [lo=%u high=%u win=%u modulator=%u",
s->dst.seqlo, s->dst.seqhi,
s->dst.max_win, s->dst.seqdiff);
if (s->src.wscale && s->dst.wscale)
printf(" wscale=%u",
s->dst.wscale & PF_WSCALE_MASK);
printf("]");
}
printf(" %u:%u", s->src.state, s->dst.state);
}
}
void
pf_print_flags(u_int8_t f)
{
if (f)
printf(" ");
if (f & TH_FIN)
printf("F");
if (f & TH_SYN)
printf("S");
if (f & TH_RST)
printf("R");
if (f & TH_PUSH)
printf("P");
if (f & TH_ACK)
printf("A");
if (f & TH_URG)
printf("U");
if (f & TH_ECE)
printf("E");
if (f & TH_CWR)
printf("W");
}
#define PF_SET_SKIP_STEPS(i) \
do { \
while (head[i] != cur) { \
head[i]->skip[i].ptr = cur; \
head[i] = TAILQ_NEXT(head[i], entries); \
} \
} while (0)
void
pf_calc_skip_steps(struct pf_rulequeue *rules)
{
struct pf_rule *cur, *prev, *head[PF_SKIP_COUNT];
int i;
cur = TAILQ_FIRST(rules);
prev = cur;
for (i = 0; i < PF_SKIP_COUNT; ++i)
head[i] = cur;
while (cur != NULL) {
if (cur->kif != prev->kif || cur->ifnot != prev->ifnot)
PF_SET_SKIP_STEPS(PF_SKIP_IFP);
if (cur->direction != prev->direction)
PF_SET_SKIP_STEPS(PF_SKIP_DIR);
if (cur->af != prev->af)
PF_SET_SKIP_STEPS(PF_SKIP_AF);
if (cur->proto != prev->proto)
PF_SET_SKIP_STEPS(PF_SKIP_PROTO);
if (cur->src.neg != prev->src.neg ||
pf_addr_wrap_neq(&cur->src.addr, &prev->src.addr))
PF_SET_SKIP_STEPS(PF_SKIP_SRC_ADDR);
if (cur->src.port[0] != prev->src.port[0] ||
cur->src.port[1] != prev->src.port[1] ||
cur->src.port_op != prev->src.port_op)
PF_SET_SKIP_STEPS(PF_SKIP_SRC_PORT);
if (cur->dst.neg != prev->dst.neg ||
pf_addr_wrap_neq(&cur->dst.addr, &prev->dst.addr))
PF_SET_SKIP_STEPS(PF_SKIP_DST_ADDR);
if (cur->dst.port[0] != prev->dst.port[0] ||
cur->dst.port[1] != prev->dst.port[1] ||
cur->dst.port_op != prev->dst.port_op)
PF_SET_SKIP_STEPS(PF_SKIP_DST_PORT);
prev = cur;
cur = TAILQ_NEXT(cur, entries);
}
for (i = 0; i < PF_SKIP_COUNT; ++i)
PF_SET_SKIP_STEPS(i);
}
static int
pf_addr_wrap_neq(struct pf_addr_wrap *aw1, struct pf_addr_wrap *aw2)
{
if (aw1->type != aw2->type)
return (1);
switch (aw1->type) {
case PF_ADDR_ADDRMASK:
case PF_ADDR_RANGE:
if (PF_ANEQ(&aw1->v.a.addr, &aw2->v.a.addr, 0))
return (1);
if (PF_ANEQ(&aw1->v.a.mask, &aw2->v.a.mask, 0))
return (1);
return (0);
case PF_ADDR_DYNIFTL:
return (aw1->p.dyn->pfid_kt != aw2->p.dyn->pfid_kt);
case PF_ADDR_NOROUTE:
case PF_ADDR_URPFFAILED:
return (0);
case PF_ADDR_TABLE:
return (aw1->p.tbl != aw2->p.tbl);
default:
printf("invalid address type: %d\n", aw1->type);
return (1);
}
}
u_int16_t
pf_cksum_fixup(u_int16_t cksum, u_int16_t old, u_int16_t new, u_int8_t udp)
{
u_int32_t l;
if (udp && !cksum)
return (0x0000);
l = cksum + old - new;
l = (l >> 16) + (l & 65535);
l = l & 65535;
if (udp && !l)
return (0xFFFF);
return (l);
}
static void
pf_change_ap(struct pf_addr *a, u_int16_t *p, u_int16_t *ic, u_int16_t *pc,
struct pf_addr *an, u_int16_t pn, u_int8_t u, sa_family_t af)
{
struct pf_addr ao;
u_int16_t po = *p;
PF_ACPY(&ao, a, af);
PF_ACPY(a, an, af);
*p = pn;
switch (af) {
#ifdef INET
case AF_INET:
*ic = pf_cksum_fixup(pf_cksum_fixup(*ic,
ao.addr16[0], an->addr16[0], 0),
ao.addr16[1], an->addr16[1], 0);
*p = pn;
*pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc,
ao.addr16[0], an->addr16[0], u),
ao.addr16[1], an->addr16[1], u),
po, pn, u);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
*pc = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(*pc,
ao.addr16[0], an->addr16[0], u),
ao.addr16[1], an->addr16[1], u),
ao.addr16[2], an->addr16[2], u),
ao.addr16[3], an->addr16[3], u),
ao.addr16[4], an->addr16[4], u),
ao.addr16[5], an->addr16[5], u),
ao.addr16[6], an->addr16[6], u),
ao.addr16[7], an->addr16[7], u),
po, pn, u);
break;
#endif /* INET6 */
}
}
/* Changes a u_int32_t. Uses a void * so there are no align restrictions */
void
pf_change_a(void *a, u_int16_t *c, u_int32_t an, u_int8_t u)
{
u_int32_t ao;
memcpy(&ao, a, sizeof(ao));
memcpy(a, &an, sizeof(u_int32_t));
*c = pf_cksum_fixup(pf_cksum_fixup(*c, ao / 65536, an / 65536, u),
ao % 65536, an % 65536, u);
}
#ifdef INET6
static void
pf_change_a6(struct pf_addr *a, u_int16_t *c, struct pf_addr *an, u_int8_t u)
{
struct pf_addr ao;
PF_ACPY(&ao, a, AF_INET6);
PF_ACPY(a, an, AF_INET6);
*c = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(*c,
ao.addr16[0], an->addr16[0], u),
ao.addr16[1], an->addr16[1], u),
ao.addr16[2], an->addr16[2], u),
ao.addr16[3], an->addr16[3], u),
ao.addr16[4], an->addr16[4], u),
ao.addr16[5], an->addr16[5], u),
ao.addr16[6], an->addr16[6], u),
ao.addr16[7], an->addr16[7], u);
}
#endif /* INET6 */
static void
pf_change_icmp(struct pf_addr *ia, u_int16_t *ip, struct pf_addr *oa,
struct pf_addr *na, u_int16_t np, u_int16_t *pc, u_int16_t *h2c,
u_int16_t *ic, u_int16_t *hc, u_int8_t u, sa_family_t af)
{
struct pf_addr oia, ooa;
PF_ACPY(&oia, ia, af);
if (oa)
PF_ACPY(&ooa, oa, af);
/* Change inner protocol port, fix inner protocol checksum. */
if (ip != NULL) {
u_int16_t oip = *ip;
u_int32_t opc;
if (pc != NULL)
opc = *pc;
*ip = np;
if (pc != NULL)
*pc = pf_cksum_fixup(*pc, oip, *ip, u);
*ic = pf_cksum_fixup(*ic, oip, *ip, 0);
if (pc != NULL)
*ic = pf_cksum_fixup(*ic, opc, *pc, 0);
}
/* Change inner ip address, fix inner ip and icmp checksums. */
PF_ACPY(ia, na, af);
switch (af) {
#ifdef INET
case AF_INET: {
u_int32_t oh2c = *h2c;
*h2c = pf_cksum_fixup(pf_cksum_fixup(*h2c,
oia.addr16[0], ia->addr16[0], 0),
oia.addr16[1], ia->addr16[1], 0);
*ic = pf_cksum_fixup(pf_cksum_fixup(*ic,
oia.addr16[0], ia->addr16[0], 0),
oia.addr16[1], ia->addr16[1], 0);
*ic = pf_cksum_fixup(*ic, oh2c, *h2c, 0);
break;
}
#endif /* INET */
#ifdef INET6
case AF_INET6:
*ic = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(*ic,
oia.addr16[0], ia->addr16[0], u),
oia.addr16[1], ia->addr16[1], u),
oia.addr16[2], ia->addr16[2], u),
oia.addr16[3], ia->addr16[3], u),
oia.addr16[4], ia->addr16[4], u),
oia.addr16[5], ia->addr16[5], u),
oia.addr16[6], ia->addr16[6], u),
oia.addr16[7], ia->addr16[7], u);
break;
#endif /* INET6 */
}
/* Outer ip address, fix outer ip or icmpv6 checksum, if necessary. */
if (oa) {
PF_ACPY(oa, na, af);
switch (af) {
#ifdef INET
case AF_INET:
*hc = pf_cksum_fixup(pf_cksum_fixup(*hc,
ooa.addr16[0], oa->addr16[0], 0),
ooa.addr16[1], oa->addr16[1], 0);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
*ic = pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(pf_cksum_fixup(
pf_cksum_fixup(pf_cksum_fixup(*ic,
ooa.addr16[0], oa->addr16[0], u),
ooa.addr16[1], oa->addr16[1], u),
ooa.addr16[2], oa->addr16[2], u),
ooa.addr16[3], oa->addr16[3], u),
ooa.addr16[4], oa->addr16[4], u),
ooa.addr16[5], oa->addr16[5], u),
ooa.addr16[6], oa->addr16[6], u),
ooa.addr16[7], oa->addr16[7], u);
break;
#endif /* INET6 */
}
}
}
/*
* Need to modulate the sequence numbers in the TCP SACK option
* (credits to Krzysztof Pfaff for report and patch)
*/
static int
pf_modulate_sack(struct mbuf *m, int off, struct pf_pdesc *pd,
struct tcphdr *th, struct pf_state_peer *dst)
{
int hlen = (th->th_off << 2) - sizeof(*th), thoptlen = hlen;
u_int8_t opts[TCP_MAXOLEN], *opt = opts;
int copyback = 0, i, olen;
struct sackblk sack;
#define TCPOLEN_SACKLEN (TCPOLEN_SACK + 2)
if (hlen < TCPOLEN_SACKLEN ||
!pf_pull_hdr(m, off + sizeof(*th), opts, hlen, NULL, NULL, pd->af))
return 0;
while (hlen >= TCPOLEN_SACKLEN) {
olen = opt[1];
switch (*opt) {
case TCPOPT_EOL: /* FALLTHROUGH */
case TCPOPT_NOP:
opt++;
hlen--;
break;
case TCPOPT_SACK:
if (olen > hlen)
olen = hlen;
if (olen >= TCPOLEN_SACKLEN) {
for (i = 2; i + TCPOLEN_SACK <= olen;
i += TCPOLEN_SACK) {
memcpy(&sack, &opt[i], sizeof(sack));
pf_change_a(&sack.start, &th->th_sum,
htonl(ntohl(sack.start) -
dst->seqdiff), 0);
pf_change_a(&sack.end, &th->th_sum,
htonl(ntohl(sack.end) -
dst->seqdiff), 0);
memcpy(&opt[i], &sack, sizeof(sack));
}
copyback = 1;
}
/* FALLTHROUGH */
default:
if (olen < 2)
olen = 2;
hlen -= olen;
opt += olen;
}
}
if (copyback)
m_copyback(m, off + sizeof(*th), thoptlen, (caddr_t)opts);
return (copyback);
}
static void
pf_send_tcp(struct mbuf *replyto, const struct pf_rule *r, sa_family_t af,
const struct pf_addr *saddr, const struct pf_addr *daddr,
u_int16_t sport, u_int16_t dport, u_int32_t seq, u_int32_t ack,
u_int8_t flags, u_int16_t win, u_int16_t mss, u_int8_t ttl, int tag,
u_int16_t rtag, struct ifnet *ifp)
{
struct pf_send_entry *pfse;
struct mbuf *m;
int len, tlen;
#ifdef INET
struct ip *h = NULL;
#endif /* INET */
#ifdef INET6
struct ip6_hdr *h6 = NULL;
#endif /* INET6 */
struct tcphdr *th;
char *opt;
struct pf_mtag *pf_mtag;
len = 0;
th = NULL;
/* maximum segment size tcp option */
tlen = sizeof(struct tcphdr);
if (mss)
tlen += 4;
switch (af) {
#ifdef INET
case AF_INET:
len = sizeof(struct ip) + tlen;
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
len = sizeof(struct ip6_hdr) + tlen;
break;
#endif /* INET6 */
default:
panic("%s: unsupported af %d", __func__, af);
}
/* Allocate outgoing queue entry, mbuf and mbuf tag. */
pfse = malloc(sizeof(*pfse), M_PFTEMP, M_NOWAIT);
if (pfse == NULL)
return;
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL) {
free(pfse, M_PFTEMP);
return;
}
#ifdef MAC
mac_netinet_firewall_send(m);
#endif
if ((pf_mtag = pf_get_mtag(m)) == NULL) {
free(pfse, M_PFTEMP);
m_freem(m);
return;
}
if (tag)
m->m_flags |= M_SKIP_FIREWALL;
pf_mtag->tag = rtag;
if (r != NULL && r->rtableid >= 0)
M_SETFIB(m, r->rtableid);
#ifdef ALTQ
if (r != NULL && r->qid) {
pf_mtag->qid = r->qid;
/* add hints for ecn */
pf_mtag->hdr = mtod(m, struct ip *);
}
#endif /* ALTQ */
m->m_data += max_linkhdr;
m->m_pkthdr.len = m->m_len = len;
m->m_pkthdr.rcvif = NULL;
bzero(m->m_data, len);
switch (af) {
#ifdef INET
case AF_INET:
h = mtod(m, struct ip *);
/* IP header fields included in the TCP checksum */
h->ip_p = IPPROTO_TCP;
h->ip_len = htons(tlen);
h->ip_src.s_addr = saddr->v4.s_addr;
h->ip_dst.s_addr = daddr->v4.s_addr;
th = (struct tcphdr *)((caddr_t)h + sizeof(struct ip));
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
h6 = mtod(m, struct ip6_hdr *);
/* IP header fields included in the TCP checksum */
h6->ip6_nxt = IPPROTO_TCP;
h6->ip6_plen = htons(tlen);
memcpy(&h6->ip6_src, &saddr->v6, sizeof(struct in6_addr));
memcpy(&h6->ip6_dst, &daddr->v6, sizeof(struct in6_addr));
th = (struct tcphdr *)((caddr_t)h6 + sizeof(struct ip6_hdr));
break;
#endif /* INET6 */
}
/* TCP header */
th->th_sport = sport;
th->th_dport = dport;
th->th_seq = htonl(seq);
th->th_ack = htonl(ack);
th->th_off = tlen >> 2;
th->th_flags = flags;
th->th_win = htons(win);
if (mss) {
opt = (char *)(th + 1);
opt[0] = TCPOPT_MAXSEG;
opt[1] = 4;
HTONS(mss);
bcopy((caddr_t)&mss, (caddr_t)(opt + 2), 2);
}
switch (af) {
#ifdef INET
case AF_INET:
/* TCP checksum */
th->th_sum = in_cksum(m, len);
/* Finish the IP header */
h->ip_v = 4;
h->ip_hl = sizeof(*h) >> 2;
h->ip_tos = IPTOS_LOWDELAY;
h->ip_off = htons(V_path_mtu_discovery ? IP_DF : 0);
h->ip_len = htons(len);
h->ip_ttl = ttl ? ttl : V_ip_defttl;
h->ip_sum = 0;
pfse->pfse_type = PFSE_IP;
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
/* TCP checksum */
th->th_sum = in6_cksum(m, IPPROTO_TCP,
sizeof(struct ip6_hdr), tlen);
h6->ip6_vfc |= IPV6_VERSION;
h6->ip6_hlim = IPV6_DEFHLIM;
pfse->pfse_type = PFSE_IP6;
break;
#endif /* INET6 */
}
pfse->pfse_m = m;
pf_send(pfse);
}
static void
pf_send_icmp(struct mbuf *m, u_int8_t type, u_int8_t code, sa_family_t af,
struct pf_rule *r)
{
struct pf_send_entry *pfse;
struct mbuf *m0;
struct pf_mtag *pf_mtag;
/* Allocate outgoing queue entry, mbuf and mbuf tag. */
pfse = malloc(sizeof(*pfse), M_PFTEMP, M_NOWAIT);
if (pfse == NULL)
return;
if ((m0 = m_copypacket(m, M_NOWAIT)) == NULL) {
free(pfse, M_PFTEMP);
return;
}
if ((pf_mtag = pf_get_mtag(m0)) == NULL) {
free(pfse, M_PFTEMP);
return;
}
/* XXX: revisit */
m0->m_flags |= M_SKIP_FIREWALL;
if (r->rtableid >= 0)
M_SETFIB(m0, r->rtableid);
#ifdef ALTQ
if (r->qid) {
pf_mtag->qid = r->qid;
/* add hints for ecn */
pf_mtag->hdr = mtod(m0, struct ip *);
}
#endif /* ALTQ */
switch (af) {
#ifdef INET
case AF_INET:
pfse->pfse_type = PFSE_ICMP;
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
pfse->pfse_type = PFSE_ICMP6;
break;
#endif /* INET6 */
}
pfse->pfse_m = m0;
pfse->icmpopts.type = type;
pfse->icmpopts.code = code;
pf_send(pfse);
}
/*
* Return 1 if the addresses a and b match (with mask m), otherwise return 0.
* If n is 0, they match if they are equal. If n is != 0, they match if they
* are different.
*/
int
pf_match_addr(u_int8_t n, struct pf_addr *a, struct pf_addr *m,
struct pf_addr *b, sa_family_t af)
{
int match = 0;
switch (af) {
#ifdef INET
case AF_INET:
if ((a->addr32[0] & m->addr32[0]) ==
(b->addr32[0] & m->addr32[0]))
match++;
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
if (((a->addr32[0] & m->addr32[0]) ==
(b->addr32[0] & m->addr32[0])) &&
((a->addr32[1] & m->addr32[1]) ==
(b->addr32[1] & m->addr32[1])) &&
((a->addr32[2] & m->addr32[2]) ==
(b->addr32[2] & m->addr32[2])) &&
((a->addr32[3] & m->addr32[3]) ==
(b->addr32[3] & m->addr32[3])))
match++;
break;
#endif /* INET6 */
}
if (match) {
if (n)
return (0);
else
return (1);
} else {
if (n)
return (1);
else
return (0);
}
}
/*
* Return 1 if b <= a <= e, otherwise return 0.
*/
int
pf_match_addr_range(struct pf_addr *b, struct pf_addr *e,
struct pf_addr *a, sa_family_t af)
{
switch (af) {
#ifdef INET
case AF_INET:
if ((a->addr32[0] < b->addr32[0]) ||
(a->addr32[0] > e->addr32[0]))
return (0);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6: {
int i;
/* check a >= b */
for (i = 0; i < 4; ++i)
if (a->addr32[i] > b->addr32[i])
break;
else if (a->addr32[i] < b->addr32[i])
return (0);
/* check a <= e */
for (i = 0; i < 4; ++i)
if (a->addr32[i] < e->addr32[i])
break;
else if (a->addr32[i] > e->addr32[i])
return (0);
break;
}
#endif /* INET6 */
}
return (1);
}
static int
pf_match(u_int8_t op, u_int32_t a1, u_int32_t a2, u_int32_t p)
{
switch (op) {
case PF_OP_IRG:
return ((p > a1) && (p < a2));
case PF_OP_XRG:
return ((p < a1) || (p > a2));
case PF_OP_RRG:
return ((p >= a1) && (p <= a2));
case PF_OP_EQ:
return (p == a1);
case PF_OP_NE:
return (p != a1);
case PF_OP_LT:
return (p < a1);
case PF_OP_LE:
return (p <= a1);
case PF_OP_GT:
return (p > a1);
case PF_OP_GE:
return (p >= a1);
}
return (0); /* never reached */
}
int
pf_match_port(u_int8_t op, u_int16_t a1, u_int16_t a2, u_int16_t p)
{
NTOHS(a1);
NTOHS(a2);
NTOHS(p);
return (pf_match(op, a1, a2, p));
}
static int
pf_match_uid(u_int8_t op, uid_t a1, uid_t a2, uid_t u)
{
if (u == UID_MAX && op != PF_OP_EQ && op != PF_OP_NE)
return (0);
return (pf_match(op, a1, a2, u));
}
static int
pf_match_gid(u_int8_t op, gid_t a1, gid_t a2, gid_t g)
{
if (g == GID_MAX && op != PF_OP_EQ && op != PF_OP_NE)
return (0);
return (pf_match(op, a1, a2, g));
}
int
pf_match_tag(struct mbuf *m, struct pf_rule *r, int *tag, int mtag)
{
if (*tag == -1)
*tag = mtag;
return ((!r->match_tag_not && r->match_tag == *tag) ||
(r->match_tag_not && r->match_tag != *tag));
}
int
pf_tag_packet(struct mbuf *m, struct pf_pdesc *pd, int tag)
{
KASSERT(tag > 0, ("%s: tag %d", __func__, tag));
if (pd->pf_mtag == NULL && ((pd->pf_mtag = pf_get_mtag(m)) == NULL))
return (ENOMEM);
pd->pf_mtag->tag = tag;
return (0);
}
#define PF_ANCHOR_STACKSIZE 32
struct pf_anchor_stackframe {
struct pf_ruleset *rs;
struct pf_rule *r; /* XXX: + match bit */
struct pf_anchor *child;
};
/*
* XXX: We rely on malloc(9) returning pointer aligned addresses.
*/
#define PF_ANCHORSTACK_MATCH 0x00000001
#define PF_ANCHORSTACK_MASK (PF_ANCHORSTACK_MATCH)
#define PF_ANCHOR_MATCH(f) ((uintptr_t)(f)->r & PF_ANCHORSTACK_MATCH)
#define PF_ANCHOR_RULE(f) (struct pf_rule *) \
((uintptr_t)(f)->r & ~PF_ANCHORSTACK_MASK)
#define PF_ANCHOR_SET_MATCH(f) do { (f)->r = (void *) \
((uintptr_t)(f)->r | PF_ANCHORSTACK_MATCH); \
} while (0)
void
pf_step_into_anchor(struct pf_anchor_stackframe *stack, int *depth,
struct pf_ruleset **rs, int n, struct pf_rule **r, struct pf_rule **a,
int *match)
{
struct pf_anchor_stackframe *f;
PF_RULES_RASSERT();
if (match)
*match = 0;
if (*depth >= PF_ANCHOR_STACKSIZE) {
printf("%s: anchor stack overflow on %s\n",
__func__, (*r)->anchor->name);
*r = TAILQ_NEXT(*r, entries);
return;
} else if (*depth == 0 && a != NULL)
*a = *r;
f = stack + (*depth)++;
f->rs = *rs;
f->r = *r;
if ((*r)->anchor_wildcard) {
struct pf_anchor_node *parent = &(*r)->anchor->children;
if ((f->child = RB_MIN(pf_anchor_node, parent)) == NULL) {
*r = NULL;
return;
}
*rs = &f->child->ruleset;
} else {
f->child = NULL;
*rs = &(*r)->anchor->ruleset;
}
*r = TAILQ_FIRST((*rs)->rules[n].active.ptr);
}
int
pf_step_out_of_anchor(struct pf_anchor_stackframe *stack, int *depth,
struct pf_ruleset **rs, int n, struct pf_rule **r, struct pf_rule **a,
int *match)
{
struct pf_anchor_stackframe *f;
struct pf_rule *fr;
int quick = 0;
PF_RULES_RASSERT();
do {
if (*depth <= 0)
break;
f = stack + *depth - 1;
fr = PF_ANCHOR_RULE(f);
if (f->child != NULL) {
struct pf_anchor_node *parent;
/*
* This block traverses through
* a wildcard anchor.
*/
parent = &fr->anchor->children;
if (match != NULL && *match) {
/*
* If any of "*" matched, then
* "foo/ *" matched, mark frame
* appropriately.
*/
PF_ANCHOR_SET_MATCH(f);
*match = 0;
}
f->child = RB_NEXT(pf_anchor_node, parent, f->child);
if (f->child != NULL) {
*rs = &f->child->ruleset;
*r = TAILQ_FIRST((*rs)->rules[n].active.ptr);
if (*r == NULL)
continue;
else
break;
}
}
(*depth)--;
if (*depth == 0 && a != NULL)
*a = NULL;
*rs = f->rs;
if (PF_ANCHOR_MATCH(f) || (match != NULL && *match))
quick = fr->quick;
*r = TAILQ_NEXT(fr, entries);
} while (*r == NULL);
return (quick);
}
#ifdef INET6
void
pf_poolmask(struct pf_addr *naddr, struct pf_addr *raddr,
struct pf_addr *rmask, struct pf_addr *saddr, sa_family_t af)
{
switch (af) {
#ifdef INET
case AF_INET:
naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) |
((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]);
break;
#endif /* INET */
case AF_INET6:
naddr->addr32[0] = (raddr->addr32[0] & rmask->addr32[0]) |
((rmask->addr32[0] ^ 0xffffffff ) & saddr->addr32[0]);
naddr->addr32[1] = (raddr->addr32[1] & rmask->addr32[1]) |
((rmask->addr32[1] ^ 0xffffffff ) & saddr->addr32[1]);
naddr->addr32[2] = (raddr->addr32[2] & rmask->addr32[2]) |
((rmask->addr32[2] ^ 0xffffffff ) & saddr->addr32[2]);
naddr->addr32[3] = (raddr->addr32[3] & rmask->addr32[3]) |
((rmask->addr32[3] ^ 0xffffffff ) & saddr->addr32[3]);
break;
}
}
void
pf_addr_inc(struct pf_addr *addr, sa_family_t af)
{
switch (af) {
#ifdef INET
case AF_INET:
addr->addr32[0] = htonl(ntohl(addr->addr32[0]) + 1);
break;
#endif /* INET */
case AF_INET6:
if (addr->addr32[3] == 0xffffffff) {
addr->addr32[3] = 0;
if (addr->addr32[2] == 0xffffffff) {
addr->addr32[2] = 0;
if (addr->addr32[1] == 0xffffffff) {
addr->addr32[1] = 0;
addr->addr32[0] =
htonl(ntohl(addr->addr32[0]) + 1);
} else
addr->addr32[1] =
htonl(ntohl(addr->addr32[1]) + 1);
} else
addr->addr32[2] =
htonl(ntohl(addr->addr32[2]) + 1);
} else
addr->addr32[3] =
htonl(ntohl(addr->addr32[3]) + 1);
break;
}
}
#endif /* INET6 */
int
pf_socket_lookup(int direction, struct pf_pdesc *pd, struct mbuf *m)
{
struct pf_addr *saddr, *daddr;
u_int16_t sport, dport;
struct inpcbinfo *pi;
struct inpcb *inp;
pd->lookup.uid = UID_MAX;
pd->lookup.gid = GID_MAX;
switch (pd->proto) {
case IPPROTO_TCP:
if (pd->hdr.tcp == NULL)
return (-1);
sport = pd->hdr.tcp->th_sport;
dport = pd->hdr.tcp->th_dport;
pi = &V_tcbinfo;
break;
case IPPROTO_UDP:
if (pd->hdr.udp == NULL)
return (-1);
sport = pd->hdr.udp->uh_sport;
dport = pd->hdr.udp->uh_dport;
pi = &V_udbinfo;
break;
default:
return (-1);
}
if (direction == PF_IN) {
saddr = pd->src;
daddr = pd->dst;
} else {
u_int16_t p;
p = sport;
sport = dport;
dport = p;
saddr = pd->dst;
daddr = pd->src;
}
switch (pd->af) {
#ifdef INET
case AF_INET:
inp = in_pcblookup_mbuf(pi, saddr->v4, sport, daddr->v4,
dport, INPLOOKUP_RLOCKPCB, NULL, m);
if (inp == NULL) {
inp = in_pcblookup_mbuf(pi, saddr->v4, sport,
daddr->v4, dport, INPLOOKUP_WILDCARD |
INPLOOKUP_RLOCKPCB, NULL, m);
if (inp == NULL)
return (-1);
}
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
inp = in6_pcblookup_mbuf(pi, &saddr->v6, sport, &daddr->v6,
dport, INPLOOKUP_RLOCKPCB, NULL, m);
if (inp == NULL) {
inp = in6_pcblookup_mbuf(pi, &saddr->v6, sport,
&daddr->v6, dport, INPLOOKUP_WILDCARD |
INPLOOKUP_RLOCKPCB, NULL, m);
if (inp == NULL)
return (-1);
}
break;
#endif /* INET6 */
default:
return (-1);
}
INP_RLOCK_ASSERT(inp);
pd->lookup.uid = inp->inp_cred->cr_uid;
pd->lookup.gid = inp->inp_cred->cr_groups[0];
INP_RUNLOCK(inp);
return (1);
}
static u_int8_t
pf_get_wscale(struct mbuf *m, int off, u_int16_t th_off, sa_family_t af)
{
int hlen;
u_int8_t hdr[60];
u_int8_t *opt, optlen;
u_int8_t wscale = 0;
hlen = th_off << 2; /* hlen <= sizeof(hdr) */
if (hlen <= sizeof(struct tcphdr))
return (0);
if (!pf_pull_hdr(m, off, hdr, hlen, NULL, NULL, af))
return (0);
opt = hdr + sizeof(struct tcphdr);
hlen -= sizeof(struct tcphdr);
while (hlen >= 3) {
switch (*opt) {
case TCPOPT_EOL:
case TCPOPT_NOP:
++opt;
--hlen;
break;
case TCPOPT_WINDOW:
wscale = opt[2];
if (wscale > TCP_MAX_WINSHIFT)
wscale = TCP_MAX_WINSHIFT;
wscale |= PF_WSCALE_FLAG;
/* FALLTHROUGH */
default:
optlen = opt[1];
if (optlen < 2)
optlen = 2;
hlen -= optlen;
opt += optlen;
break;
}
}
return (wscale);
}
static u_int16_t
pf_get_mss(struct mbuf *m, int off, u_int16_t th_off, sa_family_t af)
{
int hlen;
u_int8_t hdr[60];
u_int8_t *opt, optlen;
u_int16_t mss = V_tcp_mssdflt;
hlen = th_off << 2; /* hlen <= sizeof(hdr) */
if (hlen <= sizeof(struct tcphdr))
return (0);
if (!pf_pull_hdr(m, off, hdr, hlen, NULL, NULL, af))
return (0);
opt = hdr + sizeof(struct tcphdr);
hlen -= sizeof(struct tcphdr);
while (hlen >= TCPOLEN_MAXSEG) {
switch (*opt) {
case TCPOPT_EOL:
case TCPOPT_NOP:
++opt;
--hlen;
break;
case TCPOPT_MAXSEG:
bcopy((caddr_t)(opt + 2), (caddr_t)&mss, 2);
NTOHS(mss);
/* FALLTHROUGH */
default:
optlen = opt[1];
if (optlen < 2)
optlen = 2;
hlen -= optlen;
opt += optlen;
break;
}
}
return (mss);
}
static u_int16_t
pf_calc_mss(struct pf_addr *addr, sa_family_t af, int rtableid, u_int16_t offer)
{
#ifdef INET
struct sockaddr_in *dst;
struct route ro;
#endif /* INET */
#ifdef INET6
struct sockaddr_in6 *dst6;
struct route_in6 ro6;
#endif /* INET6 */
struct rtentry *rt = NULL;
int hlen = 0;
u_int16_t mss = V_tcp_mssdflt;
switch (af) {
#ifdef INET
case AF_INET:
hlen = sizeof(struct ip);
bzero(&ro, sizeof(ro));
dst = (struct sockaddr_in *)&ro.ro_dst;
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = addr->v4;
in_rtalloc_ign(&ro, 0, rtableid);
rt = ro.ro_rt;
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
hlen = sizeof(struct ip6_hdr);
bzero(&ro6, sizeof(ro6));
dst6 = (struct sockaddr_in6 *)&ro6.ro_dst;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(*dst6);
dst6->sin6_addr = addr->v6;
in6_rtalloc_ign(&ro6, 0, rtableid);
rt = ro6.ro_rt;
break;
#endif /* INET6 */
}
if (rt && rt->rt_ifp) {
mss = rt->rt_ifp->if_mtu - hlen - sizeof(struct tcphdr);
mss = max(V_tcp_mssdflt, mss);
RTFREE(rt);
}
mss = min(mss, offer);
mss = max(mss, 64); /* sanity - at least max opt space */
return (mss);
}
static u_int32_t
pf_tcp_iss(struct pf_pdesc *pd)
{
MD5_CTX ctx;
u_int32_t digest[4];
if (V_pf_tcp_secret_init == 0) {
read_random(&V_pf_tcp_secret, sizeof(V_pf_tcp_secret));
MD5Init(&V_pf_tcp_secret_ctx);
MD5Update(&V_pf_tcp_secret_ctx, V_pf_tcp_secret,
sizeof(V_pf_tcp_secret));
V_pf_tcp_secret_init = 1;
}
ctx = V_pf_tcp_secret_ctx;
MD5Update(&ctx, (char *)&pd->hdr.tcp->th_sport, sizeof(u_short));
MD5Update(&ctx, (char *)&pd->hdr.tcp->th_dport, sizeof(u_short));
if (pd->af == AF_INET6) {
MD5Update(&ctx, (char *)&pd->src->v6, sizeof(struct in6_addr));
MD5Update(&ctx, (char *)&pd->dst->v6, sizeof(struct in6_addr));
} else {
MD5Update(&ctx, (char *)&pd->src->v4, sizeof(struct in_addr));
MD5Update(&ctx, (char *)&pd->dst->v4, sizeof(struct in_addr));
}
MD5Final((u_char *)digest, &ctx);
V_pf_tcp_iss_off += 4096;
#define ISN_RANDOM_INCREMENT (4096 - 1)
return (digest[0] + (arc4random() & ISN_RANDOM_INCREMENT) +
V_pf_tcp_iss_off);
#undef ISN_RANDOM_INCREMENT
}
static int
pf_test_rule(struct pf_rule **rm, struct pf_state **sm, int direction,
struct pfi_kif *kif, struct mbuf *m, int off, struct pf_pdesc *pd,
struct pf_rule **am, struct pf_ruleset **rsm, struct inpcb *inp)
{
struct pf_rule *nr = NULL;
struct pf_addr * const saddr = pd->src;
struct pf_addr * const daddr = pd->dst;
sa_family_t af = pd->af;
struct pf_rule *r, *a = NULL;
struct pf_ruleset *ruleset = NULL;
struct pf_src_node *nsn = NULL;
struct tcphdr *th = pd->hdr.tcp;
struct pf_state_key *sk = NULL, *nk = NULL;
u_short reason;
int rewrite = 0, hdrlen = 0;
int tag = -1, rtableid = -1;
int asd = 0;
int match = 0;
int state_icmp = 0;
u_int16_t sport = 0, dport = 0;
u_int16_t bproto_sum = 0, bip_sum = 0;
u_int8_t icmptype = 0, icmpcode = 0;
struct pf_anchor_stackframe anchor_stack[PF_ANCHOR_STACKSIZE];
PF_RULES_RASSERT();
if (inp != NULL) {
INP_LOCK_ASSERT(inp);
pd->lookup.uid = inp->inp_cred->cr_uid;
pd->lookup.gid = inp->inp_cred->cr_groups[0];
pd->lookup.done = 1;
}
switch (pd->proto) {
case IPPROTO_TCP:
sport = th->th_sport;
dport = th->th_dport;
hdrlen = sizeof(*th);
break;
case IPPROTO_UDP:
sport = pd->hdr.udp->uh_sport;
dport = pd->hdr.udp->uh_dport;
hdrlen = sizeof(*pd->hdr.udp);
break;
#ifdef INET
case IPPROTO_ICMP:
if (pd->af != AF_INET)
break;
sport = dport = pd->hdr.icmp->icmp_id;
hdrlen = sizeof(*pd->hdr.icmp);
icmptype = pd->hdr.icmp->icmp_type;
icmpcode = pd->hdr.icmp->icmp_code;
if (icmptype == ICMP_UNREACH ||
icmptype == ICMP_SOURCEQUENCH ||
icmptype == ICMP_REDIRECT ||
icmptype == ICMP_TIMXCEED ||
icmptype == ICMP_PARAMPROB)
state_icmp++;
break;
#endif /* INET */
#ifdef INET6
case IPPROTO_ICMPV6:
if (af != AF_INET6)
break;
sport = dport = pd->hdr.icmp6->icmp6_id;
hdrlen = sizeof(*pd->hdr.icmp6);
icmptype = pd->hdr.icmp6->icmp6_type;
icmpcode = pd->hdr.icmp6->icmp6_code;
if (icmptype == ICMP6_DST_UNREACH ||
icmptype == ICMP6_PACKET_TOO_BIG ||
icmptype == ICMP6_TIME_EXCEEDED ||
icmptype == ICMP6_PARAM_PROB)
state_icmp++;
break;
#endif /* INET6 */
default:
sport = dport = hdrlen = 0;
break;
}
r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr);
/* check packet for BINAT/NAT/RDR */
if ((nr = pf_get_translation(pd, m, off, direction, kif, &nsn, &sk,
&nk, saddr, daddr, sport, dport, anchor_stack)) != NULL) {
KASSERT(sk != NULL, ("%s: null sk", __func__));
KASSERT(nk != NULL, ("%s: null nk", __func__));
if (pd->ip_sum)
bip_sum = *pd->ip_sum;
switch (pd->proto) {
case IPPROTO_TCP:
bproto_sum = th->th_sum;
pd->proto_sum = &th->th_sum;
if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) ||
nk->port[pd->sidx] != sport) {
pf_change_ap(saddr, &th->th_sport, pd->ip_sum,
&th->th_sum, &nk->addr[pd->sidx],
nk->port[pd->sidx], 0, af);
pd->sport = &th->th_sport;
sport = th->th_sport;
}
if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) ||
nk->port[pd->didx] != dport) {
pf_change_ap(daddr, &th->th_dport, pd->ip_sum,
&th->th_sum, &nk->addr[pd->didx],
nk->port[pd->didx], 0, af);
dport = th->th_dport;
pd->dport = &th->th_dport;
}
rewrite++;
break;
case IPPROTO_UDP:
bproto_sum = pd->hdr.udp->uh_sum;
pd->proto_sum = &pd->hdr.udp->uh_sum;
if (PF_ANEQ(saddr, &nk->addr[pd->sidx], af) ||
nk->port[pd->sidx] != sport) {
pf_change_ap(saddr, &pd->hdr.udp->uh_sport,
pd->ip_sum, &pd->hdr.udp->uh_sum,
&nk->addr[pd->sidx],
nk->port[pd->sidx], 1, af);
sport = pd->hdr.udp->uh_sport;
pd->sport = &pd->hdr.udp->uh_sport;
}
if (PF_ANEQ(daddr, &nk->addr[pd->didx], af) ||
nk->port[pd->didx] != dport) {
pf_change_ap(daddr, &pd->hdr.udp->uh_dport,
pd->ip_sum, &pd->hdr.udp->uh_sum,
&nk->addr[pd->didx],
nk->port[pd->didx], 1, af);
dport = pd->hdr.udp->uh_dport;
pd->dport = &pd->hdr.udp->uh_dport;
}
rewrite++;
break;
#ifdef INET
case IPPROTO_ICMP:
nk->port[0] = nk->port[1];
if (PF_ANEQ(saddr, &nk->addr[pd->sidx], AF_INET))
pf_change_a(&saddr->v4.s_addr, pd->ip_sum,
nk->addr[pd->sidx].v4.s_addr, 0);
if (PF_ANEQ(daddr, &nk->addr[pd->didx], AF_INET))
pf_change_a(&daddr->v4.s_addr, pd->ip_sum,
nk->addr[pd->didx].v4.s_addr, 0);
if (nk->port[1] != pd->hdr.icmp->icmp_id) {
pd->hdr.icmp->icmp_cksum = pf_cksum_fixup(
pd->hdr.icmp->icmp_cksum, sport,
nk->port[1], 0);
pd->hdr.icmp->icmp_id = nk->port[1];
pd->sport = &pd->hdr.icmp->icmp_id;
}
m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp);
break;
#endif /* INET */
#ifdef INET6
case IPPROTO_ICMPV6:
nk->port[0] = nk->port[1];
if (PF_ANEQ(saddr, &nk->addr[pd->sidx], AF_INET6))
pf_change_a6(saddr, &pd->hdr.icmp6->icmp6_cksum,
&nk->addr[pd->sidx], 0);
if (PF_ANEQ(daddr, &nk->addr[pd->didx], AF_INET6))
pf_change_a6(daddr, &pd->hdr.icmp6->icmp6_cksum,
&nk->addr[pd->didx], 0);
rewrite++;
break;
#endif /* INET */
default:
switch (af) {
#ifdef INET
case AF_INET:
if (PF_ANEQ(saddr,
&nk->addr[pd->sidx], AF_INET))
pf_change_a(&saddr->v4.s_addr,
pd->ip_sum,
nk->addr[pd->sidx].v4.s_addr, 0);
if (PF_ANEQ(daddr,
&nk->addr[pd->didx], AF_INET))
pf_change_a(&daddr->v4.s_addr,
pd->ip_sum,
nk->addr[pd->didx].v4.s_addr, 0);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
if (PF_ANEQ(saddr,
&nk->addr[pd->sidx], AF_INET6))
PF_ACPY(saddr, &nk->addr[pd->sidx], af);
if (PF_ANEQ(daddr,
&nk->addr[pd->didx], AF_INET6))
PF_ACPY(saddr, &nk->addr[pd->didx], af);
break;
#endif /* INET */
}
break;
}
if (nr->natpass)
r = NULL;
pd->nat_rule = nr;
}
while (r != NULL) {
r->evaluations++;
if (pfi_kif_match(r->kif, kif) == r->ifnot)
r = r->skip[PF_SKIP_IFP].ptr;
else if (r->direction && r->direction != direction)
r = r->skip[PF_SKIP_DIR].ptr;
else if (r->af && r->af != af)
r = r->skip[PF_SKIP_AF].ptr;
else if (r->proto && r->proto != pd->proto)
r = r->skip[PF_SKIP_PROTO].ptr;
else if (PF_MISMATCHAW(&r->src.addr, saddr, af,
r->src.neg, kif, M_GETFIB(m)))
r = r->skip[PF_SKIP_SRC_ADDR].ptr;
/* tcp/udp only. port_op always 0 in other cases */
else if (r->src.port_op && !pf_match_port(r->src.port_op,
r->src.port[0], r->src.port[1], sport))
r = r->skip[PF_SKIP_SRC_PORT].ptr;
else if (PF_MISMATCHAW(&r->dst.addr, daddr, af,
r->dst.neg, NULL, M_GETFIB(m)))
r = r->skip[PF_SKIP_DST_ADDR].ptr;
/* tcp/udp only. port_op always 0 in other cases */
else if (r->dst.port_op && !pf_match_port(r->dst.port_op,
r->dst.port[0], r->dst.port[1], dport))
r = r->skip[PF_SKIP_DST_PORT].ptr;
/* icmp only. type always 0 in other cases */
else if (r->type && r->type != icmptype + 1)
r = TAILQ_NEXT(r, entries);
/* icmp only. type always 0 in other cases */
else if (r->code && r->code != icmpcode + 1)
r = TAILQ_NEXT(r, entries);
else if (r->tos && !(r->tos == pd->tos))
r = TAILQ_NEXT(r, entries);
else if (r->rule_flag & PFRULE_FRAGMENT)
r = TAILQ_NEXT(r, entries);
else if (pd->proto == IPPROTO_TCP &&
(r->flagset & th->th_flags) != r->flags)
r = TAILQ_NEXT(r, entries);
/* tcp/udp only. uid.op always 0 in other cases */
else if (r->uid.op && (pd->lookup.done || (pd->lookup.done =
pf_socket_lookup(direction, pd, m), 1)) &&
!pf_match_uid(r->uid.op, r->uid.uid[0], r->uid.uid[1],
pd->lookup.uid))
r = TAILQ_NEXT(r, entries);
/* tcp/udp only. gid.op always 0 in other cases */
else if (r->gid.op && (pd->lookup.done || (pd->lookup.done =
pf_socket_lookup(direction, pd, m), 1)) &&
!pf_match_gid(r->gid.op, r->gid.gid[0], r->gid.gid[1],
pd->lookup.gid))
r = TAILQ_NEXT(r, entries);
else if (r->prob &&
r->prob <= arc4random())
r = TAILQ_NEXT(r, entries);
else if (r->match_tag && !pf_match_tag(m, r, &tag,
pd->pf_mtag ? pd->pf_mtag->tag : 0))
r = TAILQ_NEXT(r, entries);
else if (r->os_fingerprint != PF_OSFP_ANY &&
(pd->proto != IPPROTO_TCP || !pf_osfp_match(
pf_osfp_fingerprint(pd, m, off, th),
r->os_fingerprint)))
r = TAILQ_NEXT(r, entries);
else {
if (r->tag)
tag = r->tag;
if (r->rtableid >= 0)
rtableid = r->rtableid;
if (r->anchor == NULL) {
match = 1;
*rm = r;
*am = a;
*rsm = ruleset;
if ((*rm)->quick)
break;
r = TAILQ_NEXT(r, entries);
} else
pf_step_into_anchor(anchor_stack, &asd,
&ruleset, PF_RULESET_FILTER, &r, &a,
&match);
}
if (r == NULL && pf_step_out_of_anchor(anchor_stack, &asd,
&ruleset, PF_RULESET_FILTER, &r, &a, &match))
break;
}
r = *rm;
a = *am;
ruleset = *rsm;
REASON_SET(&reason, PFRES_MATCH);
if (r->log || (nr != NULL && nr->log)) {
if (rewrite)
m_copyback(m, off, hdrlen, pd->hdr.any);
PFLOG_PACKET(kif, m, af, direction, reason, r->log ? r : nr, a,
ruleset, pd, 1);
}
if ((r->action == PF_DROP) &&
((r->rule_flag & PFRULE_RETURNRST) ||
(r->rule_flag & PFRULE_RETURNICMP) ||
(r->rule_flag & PFRULE_RETURN))) {
/* undo NAT changes, if they have taken place */
if (nr != NULL) {
PF_ACPY(saddr, &sk->addr[pd->sidx], af);
PF_ACPY(daddr, &sk->addr[pd->didx], af);
if (pd->sport)
*pd->sport = sk->port[pd->sidx];
if (pd->dport)
*pd->dport = sk->port[pd->didx];
if (pd->proto_sum)
*pd->proto_sum = bproto_sum;
if (pd->ip_sum)
*pd->ip_sum = bip_sum;
m_copyback(m, off, hdrlen, pd->hdr.any);
}
if (pd->proto == IPPROTO_TCP &&
((r->rule_flag & PFRULE_RETURNRST) ||
(r->rule_flag & PFRULE_RETURN)) &&
!(th->th_flags & TH_RST)) {
u_int32_t ack = ntohl(th->th_seq) + pd->p_len;
int len = 0;
#ifdef INET
struct ip *h4;
#endif
#ifdef INET6
struct ip6_hdr *h6;
#endif
switch (af) {
#ifdef INET
case AF_INET:
h4 = mtod(m, struct ip *);
len = ntohs(h4->ip_len) - off;
break;
#endif
#ifdef INET6
case AF_INET6:
h6 = mtod(m, struct ip6_hdr *);
len = ntohs(h6->ip6_plen) - (off - sizeof(*h6));
break;
#endif
}
if (pf_check_proto_cksum(m, off, len, IPPROTO_TCP, af))
REASON_SET(&reason, PFRES_PROTCKSUM);
else {
if (th->th_flags & TH_SYN)
ack++;
if (th->th_flags & TH_FIN)
ack++;
pf_send_tcp(m, r, af, pd->dst,
pd->src, th->th_dport, th->th_sport,
ntohl(th->th_ack), ack, TH_RST|TH_ACK, 0, 0,
r->return_ttl, 1, 0, kif->pfik_ifp);
}
} else if (pd->proto != IPPROTO_ICMP && af == AF_INET &&
r->return_icmp)
pf_send_icmp(m, r->return_icmp >> 8,
r->return_icmp & 255, af, r);
else if (pd->proto != IPPROTO_ICMPV6 && af == AF_INET6 &&
r->return_icmp6)
pf_send_icmp(m, r->return_icmp6 >> 8,
r->return_icmp6 & 255, af, r);
}
if (r->action == PF_DROP)
goto cleanup;
if (tag > 0 && pf_tag_packet(m, pd, tag)) {
REASON_SET(&reason, PFRES_MEMORY);
goto cleanup;
}
if (rtableid >= 0)
M_SETFIB(m, rtableid);
if (!state_icmp && (r->keep_state || nr != NULL ||
(pd->flags & PFDESC_TCP_NORM))) {
int action;
action = pf_create_state(r, nr, a, pd, nsn, nk, sk, m, off,
sport, dport, &rewrite, kif, sm, tag, bproto_sum, bip_sum,
hdrlen);
if (action != PF_PASS)
return (action);
} else {
if (sk != NULL)
uma_zfree(V_pf_state_key_z, sk);
if (nk != NULL)
uma_zfree(V_pf_state_key_z, nk);
}
/* copy back packet headers if we performed NAT operations */
if (rewrite)
m_copyback(m, off, hdrlen, pd->hdr.any);
if (*sm != NULL && !((*sm)->state_flags & PFSTATE_NOSYNC) &&
direction == PF_OUT &&
pfsync_defer_ptr != NULL && pfsync_defer_ptr(*sm, m))
/*
* We want the state created, but we dont
* want to send this in case a partner
* firewall has to know about it to allow
* replies through it.
*/
return (PF_DEFER);
return (PF_PASS);
cleanup:
if (sk != NULL)
uma_zfree(V_pf_state_key_z, sk);
if (nk != NULL)
uma_zfree(V_pf_state_key_z, nk);
return (PF_DROP);
}
static int
pf_create_state(struct pf_rule *r, struct pf_rule *nr, struct pf_rule *a,
struct pf_pdesc *pd, struct pf_src_node *nsn, struct pf_state_key *nk,
struct pf_state_key *sk, struct mbuf *m, int off, u_int16_t sport,
u_int16_t dport, int *rewrite, struct pfi_kif *kif, struct pf_state **sm,
int tag, u_int16_t bproto_sum, u_int16_t bip_sum, int hdrlen)
{
struct pf_state *s = NULL;
struct pf_src_node *sn = NULL;
struct tcphdr *th = pd->hdr.tcp;
u_int16_t mss = V_tcp_mssdflt;
u_short reason;
/* check maximums */
if (r->max_states &&
(counter_u64_fetch(r->states_cur) >= r->max_states)) {
counter_u64_add(V_pf_status.lcounters[LCNT_STATES], 1);
REASON_SET(&reason, PFRES_MAXSTATES);
return (PF_DROP);
}
/* src node for filter rule */
if ((r->rule_flag & PFRULE_SRCTRACK ||
r->rpool.opts & PF_POOL_STICKYADDR) &&
pf_insert_src_node(&sn, r, pd->src, pd->af) != 0) {
REASON_SET(&reason, PFRES_SRCLIMIT);
goto csfailed;
}
/* src node for translation rule */
if (nr != NULL && (nr->rpool.opts & PF_POOL_STICKYADDR) &&
pf_insert_src_node(&nsn, nr, &sk->addr[pd->sidx], pd->af)) {
REASON_SET(&reason, PFRES_SRCLIMIT);
goto csfailed;
}
s = uma_zalloc(V_pf_state_z, M_NOWAIT | M_ZERO);
if (s == NULL) {
REASON_SET(&reason, PFRES_MEMORY);
goto csfailed;
}
s->rule.ptr = r;
s->nat_rule.ptr = nr;
s->anchor.ptr = a;
STATE_INC_COUNTERS(s);
if (r->allow_opts)
s->state_flags |= PFSTATE_ALLOWOPTS;
if (r->rule_flag & PFRULE_STATESLOPPY)
s->state_flags |= PFSTATE_SLOPPY;
s->log = r->log & PF_LOG_ALL;
s->sync_state = PFSYNC_S_NONE;
if (nr != NULL)
s->log |= nr->log & PF_LOG_ALL;
switch (pd->proto) {
case IPPROTO_TCP:
s->src.seqlo = ntohl(th->th_seq);
s->src.seqhi = s->src.seqlo + pd->p_len + 1;
if ((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN &&
r->keep_state == PF_STATE_MODULATE) {
/* Generate sequence number modulator */
if ((s->src.seqdiff = pf_tcp_iss(pd) - s->src.seqlo) ==
0)
s->src.seqdiff = 1;
pf_change_a(&th->th_seq, &th->th_sum,
htonl(s->src.seqlo + s->src.seqdiff), 0);
*rewrite = 1;
} else
s->src.seqdiff = 0;
if (th->th_flags & TH_SYN) {
s->src.seqhi++;
s->src.wscale = pf_get_wscale(m, off,
th->th_off, pd->af);
}
s->src.max_win = MAX(ntohs(th->th_win), 1);
if (s->src.wscale & PF_WSCALE_MASK) {
/* Remove scale factor from initial window */
int win = s->src.max_win;
win += 1 << (s->src.wscale & PF_WSCALE_MASK);
s->src.max_win = (win - 1) >>
(s->src.wscale & PF_WSCALE_MASK);
}
if (th->th_flags & TH_FIN)
s->src.seqhi++;
s->dst.seqhi = 1;
s->dst.max_win = 1;
s->src.state = TCPS_SYN_SENT;
s->dst.state = TCPS_CLOSED;
s->timeout = PFTM_TCP_FIRST_PACKET;
break;
case IPPROTO_UDP:
s->src.state = PFUDPS_SINGLE;
s->dst.state = PFUDPS_NO_TRAFFIC;
s->timeout = PFTM_UDP_FIRST_PACKET;
break;
case IPPROTO_ICMP:
#ifdef INET6
case IPPROTO_ICMPV6:
#endif
s->timeout = PFTM_ICMP_FIRST_PACKET;
break;
default:
s->src.state = PFOTHERS_SINGLE;
s->dst.state = PFOTHERS_NO_TRAFFIC;
s->timeout = PFTM_OTHER_FIRST_PACKET;
}
if (r->rt && r->rt != PF_FASTROUTE) {
if (pf_map_addr(pd->af, r, pd->src, &s->rt_addr, NULL, &sn)) {
REASON_SET(&reason, PFRES_MAPFAILED);
pf_src_tree_remove_state(s);
STATE_DEC_COUNTERS(s);
uma_zfree(V_pf_state_z, s);
goto csfailed;
}
s->rt_kif = r->rpool.cur->kif;
}
s->creation = time_uptime;
s->expire = time_uptime;
if (sn != NULL) {
s->src_node = sn;
s->src_node->states++;
}
if (nsn != NULL) {
/* XXX We only modify one side for now. */
PF_ACPY(&nsn->raddr, &nk->addr[1], pd->af);
s->nat_src_node = nsn;
s->nat_src_node->states++;
}
if (pd->proto == IPPROTO_TCP) {
if ((pd->flags & PFDESC_TCP_NORM) && pf_normalize_tcp_init(m,
off, pd, th, &s->src, &s->dst)) {
REASON_SET(&reason, PFRES_MEMORY);
pf_src_tree_remove_state(s);
STATE_DEC_COUNTERS(s);
uma_zfree(V_pf_state_z, s);
return (PF_DROP);
}
if ((pd->flags & PFDESC_TCP_NORM) && s->src.scrub &&
pf_normalize_tcp_stateful(m, off, pd, &reason, th, s,
&s->src, &s->dst, rewrite)) {
/* This really shouldn't happen!!! */
DPFPRINTF(PF_DEBUG_URGENT,
("pf_normalize_tcp_stateful failed on first pkt"));
pf_normalize_tcp_cleanup(s);
pf_src_tree_remove_state(s);
STATE_DEC_COUNTERS(s);
uma_zfree(V_pf_state_z, s);
return (PF_DROP);
}
}
s->direction = pd->dir;
/*
* sk/nk could already been setup by pf_get_translation().
*/
if (nr == NULL) {
KASSERT((sk == NULL && nk == NULL), ("%s: nr %p sk %p, nk %p",
__func__, nr, sk, nk));
sk = pf_state_key_setup(pd, pd->src, pd->dst, sport, dport);
if (sk == NULL)
goto csfailed;
nk = sk;
} else
KASSERT((sk != NULL && nk != NULL), ("%s: nr %p sk %p, nk %p",
__func__, nr, sk, nk));
/* Swap sk/nk for PF_OUT. */
if (pf_state_insert(BOUND_IFACE(r, kif),
(pd->dir == PF_IN) ? sk : nk,
(pd->dir == PF_IN) ? nk : sk, s)) {
if (pd->proto == IPPROTO_TCP)
pf_normalize_tcp_cleanup(s);
REASON_SET(&reason, PFRES_STATEINS);
pf_src_tree_remove_state(s);
STATE_DEC_COUNTERS(s);
uma_zfree(V_pf_state_z, s);
return (PF_DROP);
} else
*sm = s;
if (tag > 0)
s->tag = tag;
if (pd->proto == IPPROTO_TCP && (th->th_flags & (TH_SYN|TH_ACK)) ==
TH_SYN && r->keep_state == PF_STATE_SYNPROXY) {
s->src.state = PF_TCPS_PROXY_SRC;
/* undo NAT changes, if they have taken place */
if (nr != NULL) {
struct pf_state_key *skt = s->key[PF_SK_WIRE];
if (pd->dir == PF_OUT)
skt = s->key[PF_SK_STACK];
PF_ACPY(pd->src, &skt->addr[pd->sidx], pd->af);
PF_ACPY(pd->dst, &skt->addr[pd->didx], pd->af);
if (pd->sport)
*pd->sport = skt->port[pd->sidx];
if (pd->dport)
*pd->dport = skt->port[pd->didx];
if (pd->proto_sum)
*pd->proto_sum = bproto_sum;
if (pd->ip_sum)
*pd->ip_sum = bip_sum;
m_copyback(m, off, hdrlen, pd->hdr.any);
}
s->src.seqhi = htonl(arc4random());
/* Find mss option */
int rtid = M_GETFIB(m);
mss = pf_get_mss(m, off, th->th_off, pd->af);
mss = pf_calc_mss(pd->src, pd->af, rtid, mss);
mss = pf_calc_mss(pd->dst, pd->af, rtid, mss);
s->src.mss = mss;
pf_send_tcp(NULL, r, pd->af, pd->dst, pd->src, th->th_dport,
th->th_sport, s->src.seqhi, ntohl(th->th_seq) + 1,
TH_SYN|TH_ACK, 0, s->src.mss, 0, 1, 0, NULL);
REASON_SET(&reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
}
return (PF_PASS);
csfailed:
if (sk != NULL)
uma_zfree(V_pf_state_key_z, sk);
if (nk != NULL)
uma_zfree(V_pf_state_key_z, nk);
if (sn != NULL && sn->states == 0 && sn->expire == 0) {
pf_unlink_src_node(sn);
pf_free_src_node(sn);
}
if (nsn != sn && nsn != NULL && nsn->states == 0 && nsn->expire == 0) {
pf_unlink_src_node(nsn);
pf_free_src_node(nsn);
}
return (PF_DROP);
}
static int
pf_test_fragment(struct pf_rule **rm, int direction, struct pfi_kif *kif,
struct mbuf *m, void *h, struct pf_pdesc *pd, struct pf_rule **am,
struct pf_ruleset **rsm)
{
struct pf_rule *r, *a = NULL;
struct pf_ruleset *ruleset = NULL;
sa_family_t af = pd->af;
u_short reason;
int tag = -1;
int asd = 0;
int match = 0;
struct pf_anchor_stackframe anchor_stack[PF_ANCHOR_STACKSIZE];
PF_RULES_RASSERT();
r = TAILQ_FIRST(pf_main_ruleset.rules[PF_RULESET_FILTER].active.ptr);
while (r != NULL) {
r->evaluations++;
if (pfi_kif_match(r->kif, kif) == r->ifnot)
r = r->skip[PF_SKIP_IFP].ptr;
else if (r->direction && r->direction != direction)
r = r->skip[PF_SKIP_DIR].ptr;
else if (r->af && r->af != af)
r = r->skip[PF_SKIP_AF].ptr;
else if (r->proto && r->proto != pd->proto)
r = r->skip[PF_SKIP_PROTO].ptr;
else if (PF_MISMATCHAW(&r->src.addr, pd->src, af,
r->src.neg, kif, M_GETFIB(m)))
r = r->skip[PF_SKIP_SRC_ADDR].ptr;
else if (PF_MISMATCHAW(&r->dst.addr, pd->dst, af,
r->dst.neg, NULL, M_GETFIB(m)))
r = r->skip[PF_SKIP_DST_ADDR].ptr;
else if (r->tos && !(r->tos == pd->tos))
r = TAILQ_NEXT(r, entries);
else if (r->os_fingerprint != PF_OSFP_ANY)
r = TAILQ_NEXT(r, entries);
else if (pd->proto == IPPROTO_UDP &&
(r->src.port_op || r->dst.port_op))
r = TAILQ_NEXT(r, entries);
else if (pd->proto == IPPROTO_TCP &&
(r->src.port_op || r->dst.port_op || r->flagset))
r = TAILQ_NEXT(r, entries);
else if ((pd->proto == IPPROTO_ICMP ||
pd->proto == IPPROTO_ICMPV6) &&
(r->type || r->code))
r = TAILQ_NEXT(r, entries);
else if (r->prob && r->prob <=
(arc4random() % (UINT_MAX - 1) + 1))
r = TAILQ_NEXT(r, entries);
else if (r->match_tag && !pf_match_tag(m, r, &tag,
pd->pf_mtag ? pd->pf_mtag->tag : 0))
r = TAILQ_NEXT(r, entries);
else {
if (r->anchor == NULL) {
match = 1;
*rm = r;
*am = a;
*rsm = ruleset;
if ((*rm)->quick)
break;
r = TAILQ_NEXT(r, entries);
} else
pf_step_into_anchor(anchor_stack, &asd,
&ruleset, PF_RULESET_FILTER, &r, &a,
&match);
}
if (r == NULL && pf_step_out_of_anchor(anchor_stack, &asd,
&ruleset, PF_RULESET_FILTER, &r, &a, &match))
break;
}
r = *rm;
a = *am;
ruleset = *rsm;
REASON_SET(&reason, PFRES_MATCH);
if (r->log)
PFLOG_PACKET(kif, m, af, direction, reason, r, a, ruleset, pd,
1);
if (r->action != PF_PASS)
return (PF_DROP);
if (tag > 0 && pf_tag_packet(m, pd, tag)) {
REASON_SET(&reason, PFRES_MEMORY);
return (PF_DROP);
}
return (PF_PASS);
}
static int
pf_tcp_track_full(struct pf_state_peer *src, struct pf_state_peer *dst,
struct pf_state **state, struct pfi_kif *kif, struct mbuf *m, int off,
struct pf_pdesc *pd, u_short *reason, int *copyback)
{
struct tcphdr *th = pd->hdr.tcp;
u_int16_t win = ntohs(th->th_win);
u_int32_t ack, end, seq, orig_seq;
u_int8_t sws, dws;
int ackskew;
if (src->wscale && dst->wscale && !(th->th_flags & TH_SYN)) {
sws = src->wscale & PF_WSCALE_MASK;
dws = dst->wscale & PF_WSCALE_MASK;
} else
sws = dws = 0;
/*
* Sequence tracking algorithm from Guido van Rooij's paper:
* http://www.madison-gurkha.com/publications/tcp_filtering/
* tcp_filtering.ps
*/
orig_seq = seq = ntohl(th->th_seq);
if (src->seqlo == 0) {
/* First packet from this end. Set its state */
if ((pd->flags & PFDESC_TCP_NORM || dst->scrub) &&
src->scrub == NULL) {
if (pf_normalize_tcp_init(m, off, pd, th, src, dst)) {
REASON_SET(reason, PFRES_MEMORY);
return (PF_DROP);
}
}
/* Deferred generation of sequence number modulator */
if (dst->seqdiff && !src->seqdiff) {
/* use random iss for the TCP server */
while ((src->seqdiff = arc4random() - seq) == 0)
;
ack = ntohl(th->th_ack) - dst->seqdiff;
pf_change_a(&th->th_seq, &th->th_sum, htonl(seq +
src->seqdiff), 0);
pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0);
*copyback = 1;
} else {
ack = ntohl(th->th_ack);
}
end = seq + pd->p_len;
if (th->th_flags & TH_SYN) {
end++;
if (dst->wscale & PF_WSCALE_FLAG) {
src->wscale = pf_get_wscale(m, off, th->th_off,
pd->af);
if (src->wscale & PF_WSCALE_FLAG) {
/* Remove scale factor from initial
* window */
sws = src->wscale & PF_WSCALE_MASK;
win = ((u_int32_t)win + (1 << sws) - 1)
>> sws;
dws = dst->wscale & PF_WSCALE_MASK;
} else {
/* fixup other window */
dst->max_win <<= dst->wscale &
PF_WSCALE_MASK;
/* in case of a retrans SYN|ACK */
dst->wscale = 0;
}
}
}
if (th->th_flags & TH_FIN)
end++;
src->seqlo = seq;
if (src->state < TCPS_SYN_SENT)
src->state = TCPS_SYN_SENT;
/*
* May need to slide the window (seqhi may have been set by
* the crappy stack check or if we picked up the connection
* after establishment)
*/
if (src->seqhi == 1 ||
SEQ_GEQ(end + MAX(1, dst->max_win << dws), src->seqhi))
src->seqhi = end + MAX(1, dst->max_win << dws);
if (win > src->max_win)
src->max_win = win;
} else {
ack = ntohl(th->th_ack) - dst->seqdiff;
if (src->seqdiff) {
/* Modulate sequence numbers */
pf_change_a(&th->th_seq, &th->th_sum, htonl(seq +
src->seqdiff), 0);
pf_change_a(&th->th_ack, &th->th_sum, htonl(ack), 0);
*copyback = 1;
}
end = seq + pd->p_len;
if (th->th_flags & TH_SYN)
end++;
if (th->th_flags & TH_FIN)
end++;
}
if ((th->th_flags & TH_ACK) == 0) {
/* Let it pass through the ack skew check */
ack = dst->seqlo;
} else if ((ack == 0 &&
(th->th_flags & (TH_ACK|TH_RST)) == (TH_ACK|TH_RST)) ||
/* broken tcp stacks do not set ack */
(dst->state < TCPS_SYN_SENT)) {
/*
* Many stacks (ours included) will set the ACK number in an
* FIN|ACK if the SYN times out -- no sequence to ACK.
*/
ack = dst->seqlo;
}
if (seq == end) {
/* Ease sequencing restrictions on no data packets */
seq = src->seqlo;
end = seq;
}
ackskew = dst->seqlo - ack;
/*
* Need to demodulate the sequence numbers in any TCP SACK options
* (Selective ACK). We could optionally validate the SACK values
* against the current ACK window, either forwards or backwards, but
* I'm not confident that SACK has been implemented properly
* everywhere. It wouldn't surprise me if several stacks accidently
* SACK too far backwards of previously ACKed data. There really aren't
* any security implications of bad SACKing unless the target stack
* doesn't validate the option length correctly. Someone trying to
* spoof into a TCP connection won't bother blindly sending SACK
* options anyway.
*/
if (dst->seqdiff && (th->th_off << 2) > sizeof(struct tcphdr)) {
if (pf_modulate_sack(m, off, pd, th, dst))
*copyback = 1;
}
#define MAXACKWINDOW (0xffff + 1500) /* 1500 is an arbitrary fudge factor */
if (SEQ_GEQ(src->seqhi, end) &&
/* Last octet inside other's window space */
SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) &&
/* Retrans: not more than one window back */
(ackskew >= -MAXACKWINDOW) &&
/* Acking not more than one reassembled fragment backwards */
(ackskew <= (MAXACKWINDOW << sws)) &&
/* Acking not more than one window forward */
((th->th_flags & TH_RST) == 0 || orig_seq == src->seqlo ||
(orig_seq == src->seqlo + 1) || (orig_seq + 1 == src->seqlo) ||
(pd->flags & PFDESC_IP_REAS) == 0)) {
/* Require an exact/+1 sequence match on resets when possible */
if (dst->scrub || src->scrub) {
if (pf_normalize_tcp_stateful(m, off, pd, reason, th,
*state, src, dst, copyback))
return (PF_DROP);
}
/* update max window */
if (src->max_win < win)
src->max_win = win;
/* synchronize sequencing */
if (SEQ_GT(end, src->seqlo))
src->seqlo = end;
/* slide the window of what the other end can send */
if (SEQ_GEQ(ack + (win << sws), dst->seqhi))
dst->seqhi = ack + MAX((win << sws), 1);
/* update states */
if (th->th_flags & TH_SYN)
if (src->state < TCPS_SYN_SENT)
src->state = TCPS_SYN_SENT;
if (th->th_flags & TH_FIN)
if (src->state < TCPS_CLOSING)
src->state = TCPS_CLOSING;
if (th->th_flags & TH_ACK) {
if (dst->state == TCPS_SYN_SENT) {
dst->state = TCPS_ESTABLISHED;
if (src->state == TCPS_ESTABLISHED &&
(*state)->src_node != NULL &&
pf_src_connlimit(state)) {
REASON_SET(reason, PFRES_SRCLIMIT);
return (PF_DROP);
}
} else if (dst->state == TCPS_CLOSING)
dst->state = TCPS_FIN_WAIT_2;
}
if (th->th_flags & TH_RST)
src->state = dst->state = TCPS_TIME_WAIT;
/* update expire time */
(*state)->expire = time_uptime;
if (src->state >= TCPS_FIN_WAIT_2 &&
dst->state >= TCPS_FIN_WAIT_2)
(*state)->timeout = PFTM_TCP_CLOSED;
else if (src->state >= TCPS_CLOSING &&
dst->state >= TCPS_CLOSING)
(*state)->timeout = PFTM_TCP_FIN_WAIT;
else if (src->state < TCPS_ESTABLISHED ||
dst->state < TCPS_ESTABLISHED)
(*state)->timeout = PFTM_TCP_OPENING;
else if (src->state >= TCPS_CLOSING ||
dst->state >= TCPS_CLOSING)
(*state)->timeout = PFTM_TCP_CLOSING;
else
(*state)->timeout = PFTM_TCP_ESTABLISHED;
/* Fall through to PASS packet */
} else if ((dst->state < TCPS_SYN_SENT ||
dst->state >= TCPS_FIN_WAIT_2 ||
src->state >= TCPS_FIN_WAIT_2) &&
SEQ_GEQ(src->seqhi + MAXACKWINDOW, end) &&
/* Within a window forward of the originating packet */
SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW)) {
/* Within a window backward of the originating packet */
/*
* This currently handles three situations:
* 1) Stupid stacks will shotgun SYNs before their peer
* replies.
* 2) When PF catches an already established stream (the
* firewall rebooted, the state table was flushed, routes
* changed...)
* 3) Packets get funky immediately after the connection
* closes (this should catch Solaris spurious ACK|FINs
* that web servers like to spew after a close)
*
* This must be a little more careful than the above code
* since packet floods will also be caught here. We don't
* update the TTL here to mitigate the damage of a packet
* flood and so the same code can handle awkward establishment
* and a loosened connection close.
* In the establishment case, a correct peer response will
* validate the connection, go through the normal state code
* and keep updating the state TTL.
*/
if (V_pf_status.debug >= PF_DEBUG_MISC) {
printf("pf: loose state match: ");
pf_print_state(*state);
pf_print_flags(th->th_flags);
printf(" seq=%u (%u) ack=%u len=%u ackskew=%d "
"pkts=%llu:%llu dir=%s,%s\n", seq, orig_seq, ack,
pd->p_len, ackskew, (unsigned long long)(*state)->packets[0],
(unsigned long long)(*state)->packets[1],
pd->dir == PF_IN ? "in" : "out",
pd->dir == (*state)->direction ? "fwd" : "rev");
}
if (dst->scrub || src->scrub) {
if (pf_normalize_tcp_stateful(m, off, pd, reason, th,
*state, src, dst, copyback))
return (PF_DROP);
}
/* update max window */
if (src->max_win < win)
src->max_win = win;
/* synchronize sequencing */
if (SEQ_GT(end, src->seqlo))
src->seqlo = end;
/* slide the window of what the other end can send */
if (SEQ_GEQ(ack + (win << sws), dst->seqhi))
dst->seqhi = ack + MAX((win << sws), 1);
/*
* Cannot set dst->seqhi here since this could be a shotgunned
* SYN and not an already established connection.
*/
if (th->th_flags & TH_FIN)
if (src->state < TCPS_CLOSING)
src->state = TCPS_CLOSING;
if (th->th_flags & TH_RST)
src->state = dst->state = TCPS_TIME_WAIT;
/* Fall through to PASS packet */
} else {
if ((*state)->dst.state == TCPS_SYN_SENT &&
(*state)->src.state == TCPS_SYN_SENT) {
/* Send RST for state mismatches during handshake */
if (!(th->th_flags & TH_RST))
pf_send_tcp(NULL, (*state)->rule.ptr, pd->af,
pd->dst, pd->src, th->th_dport,
th->th_sport, ntohl(th->th_ack), 0,
TH_RST, 0, 0,
(*state)->rule.ptr->return_ttl, 1, 0,
kif->pfik_ifp);
src->seqlo = 0;
src->seqhi = 1;
src->max_win = 1;
} else if (V_pf_status.debug >= PF_DEBUG_MISC) {
printf("pf: BAD state: ");
pf_print_state(*state);
pf_print_flags(th->th_flags);
printf(" seq=%u (%u) ack=%u len=%u ackskew=%d "
"pkts=%llu:%llu dir=%s,%s\n",
seq, orig_seq, ack, pd->p_len, ackskew,
(unsigned long long)(*state)->packets[0],
(unsigned long long)(*state)->packets[1],
pd->dir == PF_IN ? "in" : "out",
pd->dir == (*state)->direction ? "fwd" : "rev");
printf("pf: State failure on: %c %c %c %c | %c %c\n",
SEQ_GEQ(src->seqhi, end) ? ' ' : '1',
SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)) ?
' ': '2',
(ackskew >= -MAXACKWINDOW) ? ' ' : '3',
(ackskew <= (MAXACKWINDOW << sws)) ? ' ' : '4',
SEQ_GEQ(src->seqhi + MAXACKWINDOW, end) ?' ' :'5',
SEQ_GEQ(seq, src->seqlo - MAXACKWINDOW) ?' ' :'6');
}
REASON_SET(reason, PFRES_BADSTATE);
return (PF_DROP);
}
return (PF_PASS);
}
static int
pf_tcp_track_sloppy(struct pf_state_peer *src, struct pf_state_peer *dst,
struct pf_state **state, struct pf_pdesc *pd, u_short *reason)
{
struct tcphdr *th = pd->hdr.tcp;
if (th->th_flags & TH_SYN)
if (src->state < TCPS_SYN_SENT)
src->state = TCPS_SYN_SENT;
if (th->th_flags & TH_FIN)
if (src->state < TCPS_CLOSING)
src->state = TCPS_CLOSING;
if (th->th_flags & TH_ACK) {
if (dst->state == TCPS_SYN_SENT) {
dst->state = TCPS_ESTABLISHED;
if (src->state == TCPS_ESTABLISHED &&
(*state)->src_node != NULL &&
pf_src_connlimit(state)) {
REASON_SET(reason, PFRES_SRCLIMIT);
return (PF_DROP);
}
} else if (dst->state == TCPS_CLOSING) {
dst->state = TCPS_FIN_WAIT_2;
} else if (src->state == TCPS_SYN_SENT &&
dst->state < TCPS_SYN_SENT) {
/*
* Handle a special sloppy case where we only see one
* half of the connection. If there is a ACK after
* the initial SYN without ever seeing a packet from
* the destination, set the connection to established.
*/
dst->state = src->state = TCPS_ESTABLISHED;
if ((*state)->src_node != NULL &&
pf_src_connlimit(state)) {
REASON_SET(reason, PFRES_SRCLIMIT);
return (PF_DROP);
}
} else if (src->state == TCPS_CLOSING &&
dst->state == TCPS_ESTABLISHED &&
dst->seqlo == 0) {
/*
* Handle the closing of half connections where we
* don't see the full bidirectional FIN/ACK+ACK
* handshake.
*/
dst->state = TCPS_CLOSING;
}
}
if (th->th_flags & TH_RST)
src->state = dst->state = TCPS_TIME_WAIT;
/* update expire time */
(*state)->expire = time_uptime;
if (src->state >= TCPS_FIN_WAIT_2 &&
dst->state >= TCPS_FIN_WAIT_2)
(*state)->timeout = PFTM_TCP_CLOSED;
else if (src->state >= TCPS_CLOSING &&
dst->state >= TCPS_CLOSING)
(*state)->timeout = PFTM_TCP_FIN_WAIT;
else if (src->state < TCPS_ESTABLISHED ||
dst->state < TCPS_ESTABLISHED)
(*state)->timeout = PFTM_TCP_OPENING;
else if (src->state >= TCPS_CLOSING ||
dst->state >= TCPS_CLOSING)
(*state)->timeout = PFTM_TCP_CLOSING;
else
(*state)->timeout = PFTM_TCP_ESTABLISHED;
return (PF_PASS);
}
static int
pf_test_state_tcp(struct pf_state **state, int direction, struct pfi_kif *kif,
struct mbuf *m, int off, void *h, struct pf_pdesc *pd,
u_short *reason)
{
struct pf_state_key_cmp key;
struct tcphdr *th = pd->hdr.tcp;
int copyback = 0;
struct pf_state_peer *src, *dst;
struct pf_state_key *sk;
bzero(&key, sizeof(key));
key.af = pd->af;
key.proto = IPPROTO_TCP;
if (direction == PF_IN) { /* wire side, straight */
PF_ACPY(&key.addr[0], pd->src, key.af);
PF_ACPY(&key.addr[1], pd->dst, key.af);
key.port[0] = th->th_sport;
key.port[1] = th->th_dport;
} else { /* stack side, reverse */
PF_ACPY(&key.addr[1], pd->src, key.af);
PF_ACPY(&key.addr[0], pd->dst, key.af);
key.port[1] = th->th_sport;
key.port[0] = th->th_dport;
}
STATE_LOOKUP(kif, &key, direction, *state, pd);
if (direction == (*state)->direction) {
src = &(*state)->src;
dst = &(*state)->dst;
} else {
src = &(*state)->dst;
dst = &(*state)->src;
}
sk = (*state)->key[pd->didx];
if ((*state)->src.state == PF_TCPS_PROXY_SRC) {
if (direction != (*state)->direction) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
}
if (th->th_flags & TH_SYN) {
if (ntohl(th->th_seq) != (*state)->src.seqlo) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_DROP);
}
pf_send_tcp(NULL, (*state)->rule.ptr, pd->af, pd->dst,
pd->src, th->th_dport, th->th_sport,
(*state)->src.seqhi, ntohl(th->th_seq) + 1,
TH_SYN|TH_ACK, 0, (*state)->src.mss, 0, 1, 0, NULL);
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
} else if (!(th->th_flags & TH_ACK) ||
(ntohl(th->th_ack) != (*state)->src.seqhi + 1) ||
(ntohl(th->th_seq) != (*state)->src.seqlo + 1)) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_DROP);
} else if ((*state)->src_node != NULL &&
pf_src_connlimit(state)) {
REASON_SET(reason, PFRES_SRCLIMIT);
return (PF_DROP);
} else
(*state)->src.state = PF_TCPS_PROXY_DST;
}
if ((*state)->src.state == PF_TCPS_PROXY_DST) {
if (direction == (*state)->direction) {
if (((th->th_flags & (TH_SYN|TH_ACK)) != TH_ACK) ||
(ntohl(th->th_ack) != (*state)->src.seqhi + 1) ||
(ntohl(th->th_seq) != (*state)->src.seqlo + 1)) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_DROP);
}
(*state)->src.max_win = MAX(ntohs(th->th_win), 1);
if ((*state)->dst.seqhi == 1)
(*state)->dst.seqhi = htonl(arc4random());
pf_send_tcp(NULL, (*state)->rule.ptr, pd->af,
&sk->addr[pd->sidx], &sk->addr[pd->didx],
sk->port[pd->sidx], sk->port[pd->didx],
(*state)->dst.seqhi, 0, TH_SYN, 0,
(*state)->src.mss, 0, 0, (*state)->tag, NULL);
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
} else if (((th->th_flags & (TH_SYN|TH_ACK)) !=
(TH_SYN|TH_ACK)) ||
(ntohl(th->th_ack) != (*state)->dst.seqhi + 1)) {
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_DROP);
} else {
(*state)->dst.max_win = MAX(ntohs(th->th_win), 1);
(*state)->dst.seqlo = ntohl(th->th_seq);
pf_send_tcp(NULL, (*state)->rule.ptr, pd->af, pd->dst,
pd->src, th->th_dport, th->th_sport,
ntohl(th->th_ack), ntohl(th->th_seq) + 1,
TH_ACK, (*state)->src.max_win, 0, 0, 0,
(*state)->tag, NULL);
pf_send_tcp(NULL, (*state)->rule.ptr, pd->af,
&sk->addr[pd->sidx], &sk->addr[pd->didx],
sk->port[pd->sidx], sk->port[pd->didx],
(*state)->src.seqhi + 1, (*state)->src.seqlo + 1,
TH_ACK, (*state)->dst.max_win, 0, 0, 1, 0, NULL);
(*state)->src.seqdiff = (*state)->dst.seqhi -
(*state)->src.seqlo;
(*state)->dst.seqdiff = (*state)->src.seqhi -
(*state)->dst.seqlo;
(*state)->src.seqhi = (*state)->src.seqlo +
(*state)->dst.max_win;
(*state)->dst.seqhi = (*state)->dst.seqlo +
(*state)->src.max_win;
(*state)->src.wscale = (*state)->dst.wscale = 0;
(*state)->src.state = (*state)->dst.state =
TCPS_ESTABLISHED;
REASON_SET(reason, PFRES_SYNPROXY);
return (PF_SYNPROXY_DROP);
}
}
if (((th->th_flags & (TH_SYN|TH_ACK)) == TH_SYN) &&
dst->state >= TCPS_FIN_WAIT_2 &&
src->state >= TCPS_FIN_WAIT_2) {
if (V_pf_status.debug >= PF_DEBUG_MISC) {
printf("pf: state reuse ");
pf_print_state(*state);
pf_print_flags(th->th_flags);
printf("\n");
}
/* XXX make sure it's the same direction ?? */
(*state)->src.state = (*state)->dst.state = TCPS_CLOSED;
pf_unlink_state(*state, PF_ENTER_LOCKED);
*state = NULL;
return (PF_DROP);
}
if ((*state)->state_flags & PFSTATE_SLOPPY) {
if (pf_tcp_track_sloppy(src, dst, state, pd, reason) == PF_DROP)
return (PF_DROP);
} else {
if (pf_tcp_track_full(src, dst, state, kif, m, off, pd, reason,
&copyback) == PF_DROP)
return (PF_DROP);
}
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk = (*state)->key[pd->didx];
if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) ||
nk->port[pd->sidx] != th->th_sport)
pf_change_ap(pd->src, &th->th_sport, pd->ip_sum,
&th->th_sum, &nk->addr[pd->sidx],
nk->port[pd->sidx], 0, pd->af);
if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) ||
nk->port[pd->didx] != th->th_dport)
pf_change_ap(pd->dst, &th->th_dport, pd->ip_sum,
&th->th_sum, &nk->addr[pd->didx],
nk->port[pd->didx], 0, pd->af);
copyback = 1;
}
/* Copyback sequence modulation or stateful scrub changes if needed */
if (copyback)
m_copyback(m, off, sizeof(*th), (caddr_t)th);
return (PF_PASS);
}
static int
pf_test_state_udp(struct pf_state **state, int direction, struct pfi_kif *kif,
struct mbuf *m, int off, void *h, struct pf_pdesc *pd)
{
struct pf_state_peer *src, *dst;
struct pf_state_key_cmp key;
struct udphdr *uh = pd->hdr.udp;
bzero(&key, sizeof(key));
key.af = pd->af;
key.proto = IPPROTO_UDP;
if (direction == PF_IN) { /* wire side, straight */
PF_ACPY(&key.addr[0], pd->src, key.af);
PF_ACPY(&key.addr[1], pd->dst, key.af);
key.port[0] = uh->uh_sport;
key.port[1] = uh->uh_dport;
} else { /* stack side, reverse */
PF_ACPY(&key.addr[1], pd->src, key.af);
PF_ACPY(&key.addr[0], pd->dst, key.af);
key.port[1] = uh->uh_sport;
key.port[0] = uh->uh_dport;
}
STATE_LOOKUP(kif, &key, direction, *state, pd);
if (direction == (*state)->direction) {
src = &(*state)->src;
dst = &(*state)->dst;
} else {
src = &(*state)->dst;
dst = &(*state)->src;
}
/* update states */
if (src->state < PFUDPS_SINGLE)
src->state = PFUDPS_SINGLE;
if (dst->state == PFUDPS_SINGLE)
dst->state = PFUDPS_MULTIPLE;
/* update expire time */
(*state)->expire = time_uptime;
if (src->state == PFUDPS_MULTIPLE && dst->state == PFUDPS_MULTIPLE)
(*state)->timeout = PFTM_UDP_MULTIPLE;
else
(*state)->timeout = PFTM_UDP_SINGLE;
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk = (*state)->key[pd->didx];
if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], pd->af) ||
nk->port[pd->sidx] != uh->uh_sport)
pf_change_ap(pd->src, &uh->uh_sport, pd->ip_sum,
&uh->uh_sum, &nk->addr[pd->sidx],
nk->port[pd->sidx], 1, pd->af);
if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], pd->af) ||
nk->port[pd->didx] != uh->uh_dport)
pf_change_ap(pd->dst, &uh->uh_dport, pd->ip_sum,
&uh->uh_sum, &nk->addr[pd->didx],
nk->port[pd->didx], 1, pd->af);
m_copyback(m, off, sizeof(*uh), (caddr_t)uh);
}
return (PF_PASS);
}
static int
pf_test_state_icmp(struct pf_state **state, int direction, struct pfi_kif *kif,
struct mbuf *m, int off, void *h, struct pf_pdesc *pd, u_short *reason)
{
struct pf_addr *saddr = pd->src, *daddr = pd->dst;
u_int16_t icmpid = 0, *icmpsum;
u_int8_t icmptype;
int state_icmp = 0;
struct pf_state_key_cmp key;
bzero(&key, sizeof(key));
switch (pd->proto) {
#ifdef INET
case IPPROTO_ICMP:
icmptype = pd->hdr.icmp->icmp_type;
icmpid = pd->hdr.icmp->icmp_id;
icmpsum = &pd->hdr.icmp->icmp_cksum;
if (icmptype == ICMP_UNREACH ||
icmptype == ICMP_SOURCEQUENCH ||
icmptype == ICMP_REDIRECT ||
icmptype == ICMP_TIMXCEED ||
icmptype == ICMP_PARAMPROB)
state_icmp++;
break;
#endif /* INET */
#ifdef INET6
case IPPROTO_ICMPV6:
icmptype = pd->hdr.icmp6->icmp6_type;
icmpid = pd->hdr.icmp6->icmp6_id;
icmpsum = &pd->hdr.icmp6->icmp6_cksum;
if (icmptype == ICMP6_DST_UNREACH ||
icmptype == ICMP6_PACKET_TOO_BIG ||
icmptype == ICMP6_TIME_EXCEEDED ||
icmptype == ICMP6_PARAM_PROB)
state_icmp++;
break;
#endif /* INET6 */
}
if (!state_icmp) {
/*
* ICMP query/reply message not related to a TCP/UDP packet.
* Search for an ICMP state.
*/
key.af = pd->af;
key.proto = pd->proto;
key.port[0] = key.port[1] = icmpid;
if (direction == PF_IN) { /* wire side, straight */
PF_ACPY(&key.addr[0], pd->src, key.af);
PF_ACPY(&key.addr[1], pd->dst, key.af);
} else { /* stack side, reverse */
PF_ACPY(&key.addr[1], pd->src, key.af);
PF_ACPY(&key.addr[0], pd->dst, key.af);
}
STATE_LOOKUP(kif, &key, direction, *state, pd);
(*state)->expire = time_uptime;
(*state)->timeout = PFTM_ICMP_ERROR_REPLY;
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk = (*state)->key[pd->didx];
switch (pd->af) {
#ifdef INET
case AF_INET:
if (PF_ANEQ(pd->src,
&nk->addr[pd->sidx], AF_INET))
pf_change_a(&saddr->v4.s_addr,
pd->ip_sum,
nk->addr[pd->sidx].v4.s_addr, 0);
if (PF_ANEQ(pd->dst, &nk->addr[pd->didx],
AF_INET))
pf_change_a(&daddr->v4.s_addr,
pd->ip_sum,
nk->addr[pd->didx].v4.s_addr, 0);
if (nk->port[0] !=
pd->hdr.icmp->icmp_id) {
pd->hdr.icmp->icmp_cksum =
pf_cksum_fixup(
pd->hdr.icmp->icmp_cksum, icmpid,
nk->port[pd->sidx], 0);
pd->hdr.icmp->icmp_id =
nk->port[pd->sidx];
}
m_copyback(m, off, ICMP_MINLEN,
(caddr_t )pd->hdr.icmp);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
if (PF_ANEQ(pd->src,
&nk->addr[pd->sidx], AF_INET6))
pf_change_a6(saddr,
&pd->hdr.icmp6->icmp6_cksum,
&nk->addr[pd->sidx], 0);
if (PF_ANEQ(pd->dst,
&nk->addr[pd->didx], AF_INET6))
pf_change_a6(daddr,
&pd->hdr.icmp6->icmp6_cksum,
&nk->addr[pd->didx], 0);
m_copyback(m, off, sizeof(struct icmp6_hdr),
(caddr_t )pd->hdr.icmp6);
break;
#endif /* INET6 */
}
}
return (PF_PASS);
} else {
/*
* ICMP error message in response to a TCP/UDP packet.
* Extract the inner TCP/UDP header and search for that state.
*/
struct pf_pdesc pd2;
bzero(&pd2, sizeof pd2);
#ifdef INET
struct ip h2;
#endif /* INET */
#ifdef INET6
struct ip6_hdr h2_6;
int terminal = 0;
#endif /* INET6 */
int ipoff2 = 0;
int off2 = 0;
pd2.af = pd->af;
/* Payload packet is from the opposite direction. */
pd2.sidx = (direction == PF_IN) ? 1 : 0;
pd2.didx = (direction == PF_IN) ? 0 : 1;
switch (pd->af) {
#ifdef INET
case AF_INET:
/* offset of h2 in mbuf chain */
ipoff2 = off + ICMP_MINLEN;
if (!pf_pull_hdr(m, ipoff2, &h2, sizeof(h2),
NULL, reason, pd2.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: ICMP error message too short "
"(ip)\n"));
return (PF_DROP);
}
/*
* ICMP error messages don't refer to non-first
* fragments
*/
if (h2.ip_off & htons(IP_OFFMASK)) {
REASON_SET(reason, PFRES_FRAG);
return (PF_DROP);
}
/* offset of protocol header that follows h2 */
off2 = ipoff2 + (h2.ip_hl << 2);
pd2.proto = h2.ip_p;
pd2.src = (struct pf_addr *)&h2.ip_src;
pd2.dst = (struct pf_addr *)&h2.ip_dst;
pd2.ip_sum = &h2.ip_sum;
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
ipoff2 = off + sizeof(struct icmp6_hdr);
if (!pf_pull_hdr(m, ipoff2, &h2_6, sizeof(h2_6),
NULL, reason, pd2.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: ICMP error message too short "
"(ip6)\n"));
return (PF_DROP);
}
pd2.proto = h2_6.ip6_nxt;
pd2.src = (struct pf_addr *)&h2_6.ip6_src;
pd2.dst = (struct pf_addr *)&h2_6.ip6_dst;
pd2.ip_sum = NULL;
off2 = ipoff2 + sizeof(h2_6);
do {
switch (pd2.proto) {
case IPPROTO_FRAGMENT:
/*
* ICMPv6 error messages for
* non-first fragments
*/
REASON_SET(reason, PFRES_FRAG);
return (PF_DROP);
case IPPROTO_AH:
case IPPROTO_HOPOPTS:
case IPPROTO_ROUTING:
case IPPROTO_DSTOPTS: {
/* get next header and header length */
struct ip6_ext opt6;
if (!pf_pull_hdr(m, off2, &opt6,
sizeof(opt6), NULL, reason,
pd2.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: ICMPv6 short opt\n"));
return (PF_DROP);
}
if (pd2.proto == IPPROTO_AH)
off2 += (opt6.ip6e_len + 2) * 4;
else
off2 += (opt6.ip6e_len + 1) * 8;
pd2.proto = opt6.ip6e_nxt;
/* goto the next header */
break;
}
default:
terminal++;
break;
}
} while (!terminal);
break;
#endif /* INET6 */
}
switch (pd2.proto) {
case IPPROTO_TCP: {
struct tcphdr th;
u_int32_t seq;
struct pf_state_peer *src, *dst;
u_int8_t dws;
int copyback = 0;
/*
* Only the first 8 bytes of the TCP header can be
* expected. Don't access any TCP header fields after
* th_seq, an ackskew test is not possible.
*/
if (!pf_pull_hdr(m, off2, &th, 8, NULL, reason,
pd2.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: ICMP error message too short "
"(tcp)\n"));
return (PF_DROP);
}
key.af = pd2.af;
key.proto = IPPROTO_TCP;
PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
key.port[pd2.sidx] = th.th_sport;
key.port[pd2.didx] = th.th_dport;
STATE_LOOKUP(kif, &key, direction, *state, pd);
if (direction == (*state)->direction) {
src = &(*state)->dst;
dst = &(*state)->src;
} else {
src = &(*state)->src;
dst = &(*state)->dst;
}
if (src->wscale && dst->wscale)
dws = dst->wscale & PF_WSCALE_MASK;
else
dws = 0;
/* Demodulate sequence number */
seq = ntohl(th.th_seq) - src->seqdiff;
if (src->seqdiff) {
pf_change_a(&th.th_seq, icmpsum,
htonl(seq), 0);
copyback = 1;
}
if (!((*state)->state_flags & PFSTATE_SLOPPY) &&
(!SEQ_GEQ(src->seqhi, seq) ||
!SEQ_GEQ(seq, src->seqlo - (dst->max_win << dws)))) {
if (V_pf_status.debug >= PF_DEBUG_MISC) {
printf("pf: BAD ICMP %d:%d ",
icmptype, pd->hdr.icmp->icmp_code);
pf_print_host(pd->src, 0, pd->af);
printf(" -> ");
pf_print_host(pd->dst, 0, pd->af);
printf(" state: ");
pf_print_state(*state);
printf(" seq=%u\n", seq);
}
REASON_SET(reason, PFRES_BADSTATE);
return (PF_DROP);
} else {
if (V_pf_status.debug >= PF_DEBUG_MISC) {
printf("pf: OK ICMP %d:%d ",
icmptype, pd->hdr.icmp->icmp_code);
pf_print_host(pd->src, 0, pd->af);
printf(" -> ");
pf_print_host(pd->dst, 0, pd->af);
printf(" state: ");
pf_print_state(*state);
printf(" seq=%u\n", seq);
}
}
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] !=
(*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk =
(*state)->key[pd->didx];
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af) ||
nk->port[pd2.sidx] != th.th_sport)
pf_change_icmp(pd2.src, &th.th_sport,
daddr, &nk->addr[pd2.sidx],
nk->port[pd2.sidx], NULL,
pd2.ip_sum, icmpsum,
pd->ip_sum, 0, pd2.af);
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af) ||
nk->port[pd2.didx] != th.th_dport)
pf_change_icmp(pd2.dst, &th.th_dport,
NULL, /* XXX Inbound NAT? */
&nk->addr[pd2.didx],
nk->port[pd2.didx], NULL,
pd2.ip_sum, icmpsum,
pd->ip_sum, 0, pd2.af);
copyback = 1;
}
if (copyback) {
switch (pd2.af) {
#ifdef INET
case AF_INET:
m_copyback(m, off, ICMP_MINLEN,
(caddr_t )pd->hdr.icmp);
m_copyback(m, ipoff2, sizeof(h2),
(caddr_t )&h2);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
m_copyback(m, off,
sizeof(struct icmp6_hdr),
(caddr_t )pd->hdr.icmp6);
m_copyback(m, ipoff2, sizeof(h2_6),
(caddr_t )&h2_6);
break;
#endif /* INET6 */
}
m_copyback(m, off2, 8, (caddr_t)&th);
}
return (PF_PASS);
break;
}
case IPPROTO_UDP: {
struct udphdr uh;
if (!pf_pull_hdr(m, off2, &uh, sizeof(uh),
NULL, reason, pd2.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: ICMP error message too short "
"(udp)\n"));
return (PF_DROP);
}
key.af = pd2.af;
key.proto = IPPROTO_UDP;
PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
key.port[pd2.sidx] = uh.uh_sport;
key.port[pd2.didx] = uh.uh_dport;
STATE_LOOKUP(kif, &key, direction, *state, pd);
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] !=
(*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk =
(*state)->key[pd->didx];
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af) ||
nk->port[pd2.sidx] != uh.uh_sport)
pf_change_icmp(pd2.src, &uh.uh_sport,
daddr, &nk->addr[pd2.sidx],
nk->port[pd2.sidx], &uh.uh_sum,
pd2.ip_sum, icmpsum,
pd->ip_sum, 1, pd2.af);
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af) ||
nk->port[pd2.didx] != uh.uh_dport)
pf_change_icmp(pd2.dst, &uh.uh_dport,
NULL, /* XXX Inbound NAT? */
&nk->addr[pd2.didx],
nk->port[pd2.didx], &uh.uh_sum,
pd2.ip_sum, icmpsum,
pd->ip_sum, 1, pd2.af);
switch (pd2.af) {
#ifdef INET
case AF_INET:
m_copyback(m, off, ICMP_MINLEN,
(caddr_t )pd->hdr.icmp);
m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
m_copyback(m, off,
sizeof(struct icmp6_hdr),
(caddr_t )pd->hdr.icmp6);
m_copyback(m, ipoff2, sizeof(h2_6),
(caddr_t )&h2_6);
break;
#endif /* INET6 */
}
m_copyback(m, off2, sizeof(uh), (caddr_t)&uh);
}
return (PF_PASS);
break;
}
#ifdef INET
case IPPROTO_ICMP: {
struct icmp iih;
if (!pf_pull_hdr(m, off2, &iih, ICMP_MINLEN,
NULL, reason, pd2.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: ICMP error message too short i"
"(icmp)\n"));
return (PF_DROP);
}
key.af = pd2.af;
key.proto = IPPROTO_ICMP;
PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
key.port[0] = key.port[1] = iih.icmp_id;
STATE_LOOKUP(kif, &key, direction, *state, pd);
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] !=
(*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk =
(*state)->key[pd->didx];
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af) ||
nk->port[pd2.sidx] != iih.icmp_id)
pf_change_icmp(pd2.src, &iih.icmp_id,
daddr, &nk->addr[pd2.sidx],
nk->port[pd2.sidx], NULL,
pd2.ip_sum, icmpsum,
pd->ip_sum, 0, AF_INET);
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af) ||
nk->port[pd2.didx] != iih.icmp_id)
pf_change_icmp(pd2.dst, &iih.icmp_id,
NULL, /* XXX Inbound NAT? */
&nk->addr[pd2.didx],
nk->port[pd2.didx], NULL,
pd2.ip_sum, icmpsum,
pd->ip_sum, 0, AF_INET);
m_copyback(m, off, ICMP_MINLEN, (caddr_t)pd->hdr.icmp);
m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2);
m_copyback(m, off2, ICMP_MINLEN, (caddr_t)&iih);
}
return (PF_PASS);
break;
}
#endif /* INET */
#ifdef INET6
case IPPROTO_ICMPV6: {
struct icmp6_hdr iih;
if (!pf_pull_hdr(m, off2, &iih,
sizeof(struct icmp6_hdr), NULL, reason, pd2.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: ICMP error message too short "
"(icmp6)\n"));
return (PF_DROP);
}
key.af = pd2.af;
key.proto = IPPROTO_ICMPV6;
PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
key.port[0] = key.port[1] = iih.icmp6_id;
STATE_LOOKUP(kif, &key, direction, *state, pd);
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] !=
(*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk =
(*state)->key[pd->didx];
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af) ||
nk->port[pd2.sidx] != iih.icmp6_id)
pf_change_icmp(pd2.src, &iih.icmp6_id,
daddr, &nk->addr[pd2.sidx],
nk->port[pd2.sidx], NULL,
pd2.ip_sum, icmpsum,
pd->ip_sum, 0, AF_INET6);
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af) ||
nk->port[pd2.didx] != iih.icmp6_id)
pf_change_icmp(pd2.dst, &iih.icmp6_id,
NULL, /* XXX Inbound NAT? */
&nk->addr[pd2.didx],
nk->port[pd2.didx], NULL,
pd2.ip_sum, icmpsum,
pd->ip_sum, 0, AF_INET6);
m_copyback(m, off, sizeof(struct icmp6_hdr),
(caddr_t)pd->hdr.icmp6);
m_copyback(m, ipoff2, sizeof(h2_6), (caddr_t)&h2_6);
m_copyback(m, off2, sizeof(struct icmp6_hdr),
(caddr_t)&iih);
}
return (PF_PASS);
break;
}
#endif /* INET6 */
default: {
key.af = pd2.af;
key.proto = pd2.proto;
PF_ACPY(&key.addr[pd2.sidx], pd2.src, key.af);
PF_ACPY(&key.addr[pd2.didx], pd2.dst, key.af);
key.port[0] = key.port[1] = 0;
STATE_LOOKUP(kif, &key, direction, *state, pd);
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] !=
(*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk =
(*state)->key[pd->didx];
if (PF_ANEQ(pd2.src,
&nk->addr[pd2.sidx], pd2.af))
pf_change_icmp(pd2.src, NULL, daddr,
&nk->addr[pd2.sidx], 0, NULL,
pd2.ip_sum, icmpsum,
pd->ip_sum, 0, pd2.af);
if (PF_ANEQ(pd2.dst,
&nk->addr[pd2.didx], pd2.af))
pf_change_icmp(pd2.src, NULL,
NULL, /* XXX Inbound NAT? */
&nk->addr[pd2.didx], 0, NULL,
pd2.ip_sum, icmpsum,
pd->ip_sum, 0, pd2.af);
switch (pd2.af) {
#ifdef INET
case AF_INET:
m_copyback(m, off, ICMP_MINLEN,
(caddr_t)pd->hdr.icmp);
m_copyback(m, ipoff2, sizeof(h2), (caddr_t)&h2);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
m_copyback(m, off,
sizeof(struct icmp6_hdr),
(caddr_t )pd->hdr.icmp6);
m_copyback(m, ipoff2, sizeof(h2_6),
(caddr_t )&h2_6);
break;
#endif /* INET6 */
}
}
return (PF_PASS);
break;
}
}
}
}
static int
pf_test_state_other(struct pf_state **state, int direction, struct pfi_kif *kif,
struct mbuf *m, struct pf_pdesc *pd)
{
struct pf_state_peer *src, *dst;
struct pf_state_key_cmp key;
bzero(&key, sizeof(key));
key.af = pd->af;
key.proto = pd->proto;
if (direction == PF_IN) {
PF_ACPY(&key.addr[0], pd->src, key.af);
PF_ACPY(&key.addr[1], pd->dst, key.af);
key.port[0] = key.port[1] = 0;
} else {
PF_ACPY(&key.addr[1], pd->src, key.af);
PF_ACPY(&key.addr[0], pd->dst, key.af);
key.port[1] = key.port[0] = 0;
}
STATE_LOOKUP(kif, &key, direction, *state, pd);
if (direction == (*state)->direction) {
src = &(*state)->src;
dst = &(*state)->dst;
} else {
src = &(*state)->dst;
dst = &(*state)->src;
}
/* update states */
if (src->state < PFOTHERS_SINGLE)
src->state = PFOTHERS_SINGLE;
if (dst->state == PFOTHERS_SINGLE)
dst->state = PFOTHERS_MULTIPLE;
/* update expire time */
(*state)->expire = time_uptime;
if (src->state == PFOTHERS_MULTIPLE && dst->state == PFOTHERS_MULTIPLE)
(*state)->timeout = PFTM_OTHER_MULTIPLE;
else
(*state)->timeout = PFTM_OTHER_SINGLE;
/* translate source/destination address, if necessary */
if ((*state)->key[PF_SK_WIRE] != (*state)->key[PF_SK_STACK]) {
struct pf_state_key *nk = (*state)->key[pd->didx];
KASSERT(nk, ("%s: nk is null", __func__));
KASSERT(pd, ("%s: pd is null", __func__));
KASSERT(pd->src, ("%s: pd->src is null", __func__));
KASSERT(pd->dst, ("%s: pd->dst is null", __func__));
switch (pd->af) {
#ifdef INET
case AF_INET:
if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], AF_INET))
pf_change_a(&pd->src->v4.s_addr,
pd->ip_sum,
nk->addr[pd->sidx].v4.s_addr,
0);
if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], AF_INET))
pf_change_a(&pd->dst->v4.s_addr,
pd->ip_sum,
nk->addr[pd->didx].v4.s_addr,
0);
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
if (PF_ANEQ(pd->src, &nk->addr[pd->sidx], AF_INET))
PF_ACPY(pd->src, &nk->addr[pd->sidx], pd->af);
if (PF_ANEQ(pd->dst, &nk->addr[pd->didx], AF_INET))
PF_ACPY(pd->dst, &nk->addr[pd->didx], pd->af);
#endif /* INET6 */
}
}
return (PF_PASS);
}
/*
* ipoff and off are measured from the start of the mbuf chain.
* h must be at "ipoff" on the mbuf chain.
*/
void *
pf_pull_hdr(struct mbuf *m, int off, void *p, int len,
u_short *actionp, u_short *reasonp, sa_family_t af)
{
switch (af) {
#ifdef INET
case AF_INET: {
struct ip *h = mtod(m, struct ip *);
u_int16_t fragoff = (ntohs(h->ip_off) & IP_OFFMASK) << 3;
if (fragoff) {
if (fragoff >= len)
ACTION_SET(actionp, PF_PASS);
else {
ACTION_SET(actionp, PF_DROP);
REASON_SET(reasonp, PFRES_FRAG);
}
return (NULL);
}
if (m->m_pkthdr.len < off + len ||
ntohs(h->ip_len) < off + len) {
ACTION_SET(actionp, PF_DROP);
REASON_SET(reasonp, PFRES_SHORT);
return (NULL);
}
break;
}
#endif /* INET */
#ifdef INET6
case AF_INET6: {
struct ip6_hdr *h = mtod(m, struct ip6_hdr *);
if (m->m_pkthdr.len < off + len ||
(ntohs(h->ip6_plen) + sizeof(struct ip6_hdr)) <
(unsigned)(off + len)) {
ACTION_SET(actionp, PF_DROP);
REASON_SET(reasonp, PFRES_SHORT);
return (NULL);
}
break;
}
#endif /* INET6 */
}
m_copydata(m, off, len, p);
return (p);
}
int
pf_routable(struct pf_addr *addr, sa_family_t af, struct pfi_kif *kif,
int rtableid)
{
#ifdef RADIX_MPATH
struct radix_node_head *rnh;
#endif
struct sockaddr_in *dst;
int ret = 1;
int check_mpath;
#ifdef INET6
struct sockaddr_in6 *dst6;
struct route_in6 ro;
#else
struct route ro;
#endif
struct radix_node *rn;
struct rtentry *rt;
struct ifnet *ifp;
check_mpath = 0;
#ifdef RADIX_MPATH
/* XXX: stick to table 0 for now */
rnh = rt_tables_get_rnh(0, af);
if (rnh != NULL && rn_mpath_capable(rnh))
check_mpath = 1;
#endif
bzero(&ro, sizeof(ro));
switch (af) {
case AF_INET:
dst = satosin(&ro.ro_dst);
dst->sin_family = AF_INET;
dst->sin_len = sizeof(*dst);
dst->sin_addr = addr->v4;
break;
#ifdef INET6
case AF_INET6:
/*
* Skip check for addresses with embedded interface scope,
* as they would always match anyway.
*/
if (IN6_IS_SCOPE_EMBED(&addr->v6))
goto out;
dst6 = (struct sockaddr_in6 *)&ro.ro_dst;
dst6->sin6_family = AF_INET6;
dst6->sin6_len = sizeof(*dst6);
dst6->sin6_addr = addr->v6;
break;
#endif /* INET6 */
default:
return (0);
}
/* Skip checks for ipsec interfaces */
if (kif != NULL && kif->pfik_ifp->if_type == IFT_ENC)
goto out;
switch (af) {
#ifdef INET6
case AF_INET6:
in6_rtalloc_ign(&ro, 0, rtableid);
break;
#endif
#ifdef INET
case AF_INET:
in_rtalloc_ign((struct route *)&ro, 0, rtableid);
break;
#endif
default:
rtalloc_ign((struct route *)&ro, 0); /* No/default FIB. */
break;
}
if (ro.ro_rt != NULL) {
/* No interface given, this is a no-route check */
if (kif == NULL)
goto out;
if (kif->pfik_ifp == NULL) {
ret = 0;
goto out;
}
/* Perform uRPF check if passed input interface */
ret = 0;
rn = (struct radix_node *)ro.ro_rt;
do {
rt = (struct rtentry *)rn;
ifp = rt->rt_ifp;
if (kif->pfik_ifp == ifp)
ret = 1;
#ifdef RADIX_MPATH
rn = rn_mpath_next(rn);
#endif
} while (check_mpath == 1 && rn != NULL && ret == 0);
} else
ret = 0;
out:
if (ro.ro_rt != NULL)
RTFREE(ro.ro_rt);
return (ret);
}
#ifdef INET
static void
pf_route(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp,
struct pf_state *s, struct pf_pdesc *pd)
{
struct mbuf *m0, *m1;
struct sockaddr_in dst;
struct ip *ip;
struct ifnet *ifp = NULL;
struct pf_addr naddr;
struct pf_src_node *sn = NULL;
int error = 0;
uint16_t ip_len, ip_off;
KASSERT(m && *m && r && oifp, ("%s: invalid parameters", __func__));
KASSERT(dir == PF_IN || dir == PF_OUT, ("%s: invalid direction",
__func__));
if ((pd->pf_mtag == NULL &&
((pd->pf_mtag = pf_get_mtag(*m)) == NULL)) ||
pd->pf_mtag->routed++ > 3) {
m0 = *m;
*m = NULL;
goto bad_locked;
}
if (r->rt == PF_DUPTO) {
if ((m0 = m_dup(*m, M_NOWAIT)) == NULL) {
if (s)
PF_STATE_UNLOCK(s);
return;
}
} else {
if ((r->rt == PF_REPLYTO) == (r->direction == dir)) {
if (s)
PF_STATE_UNLOCK(s);
return;
}
m0 = *m;
}
ip = mtod(m0, struct ip *);
bzero(&dst, sizeof(dst));
dst.sin_family = AF_INET;
dst.sin_len = sizeof(dst);
dst.sin_addr = ip->ip_dst;
if (r->rt == PF_FASTROUTE) {
struct rtentry *rt;
if (s)
PF_STATE_UNLOCK(s);
rt = rtalloc1_fib(sintosa(&dst), 0, 0, M_GETFIB(m0));
if (rt == NULL) {
KMOD_IPSTAT_INC(ips_noroute);
error = EHOSTUNREACH;
goto bad;
}
ifp = rt->rt_ifp;
counter_u64_add(rt->rt_pksent, 1);
if (rt->rt_flags & RTF_GATEWAY)
bcopy(satosin(rt->rt_gateway), &dst, sizeof(dst));
RTFREE_LOCKED(rt);
} else {
if (TAILQ_EMPTY(&r->rpool.list)) {
DPFPRINTF(PF_DEBUG_URGENT,
("%s: TAILQ_EMPTY(&r->rpool.list)\n", __func__));
goto bad_locked;
}
if (s == NULL) {
pf_map_addr(AF_INET, r, (struct pf_addr *)&ip->ip_src,
&naddr, NULL, &sn);
if (!PF_AZERO(&naddr, AF_INET))
dst.sin_addr.s_addr = naddr.v4.s_addr;
ifp = r->rpool.cur->kif ?
r->rpool.cur->kif->pfik_ifp : NULL;
} else {
if (!PF_AZERO(&s->rt_addr, AF_INET))
dst.sin_addr.s_addr =
s->rt_addr.v4.s_addr;
ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL;
PF_STATE_UNLOCK(s);
}
}
if (ifp == NULL)
goto bad;
if (oifp != ifp) {
if (pf_test(PF_OUT, ifp, &m0, NULL) != PF_PASS)
goto bad;
else if (m0 == NULL)
goto done;
if (m0->m_len < sizeof(struct ip)) {
DPFPRINTF(PF_DEBUG_URGENT,
("%s: m0->m_len < sizeof(struct ip)\n", __func__));
goto bad;
}
ip = mtod(m0, struct ip *);
}
if (ifp->if_flags & IFF_LOOPBACK)
m0->m_flags |= M_SKIP_FIREWALL;
ip_len = ntohs(ip->ip_len);
ip_off = ntohs(ip->ip_off);
/* Copied from FreeBSD 10.0-CURRENT ip_output. */
m0->m_pkthdr.csum_flags |= CSUM_IP;
if (m0->m_pkthdr.csum_flags & CSUM_DELAY_DATA & ~ifp->if_hwassist) {
in_delayed_cksum(m0);
m0->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
#ifdef SCTP
if (m0->m_pkthdr.csum_flags & CSUM_SCTP & ~ifp->if_hwassist) {
sctp_delayed_cksum(m, (uint32_t)(ip->ip_hl << 2));
m0->m_pkthdr.csum_flags &= ~CSUM_SCTP;
}
#endif
/*
* If small enough for interface, or the interface will take
* care of the fragmentation for us, we can just send directly.
*/
if (ip_len <= ifp->if_mtu ||
(m0->m_pkthdr.csum_flags & ifp->if_hwassist & CSUM_TSO) != 0) {
ip->ip_sum = 0;
if (m0->m_pkthdr.csum_flags & CSUM_IP & ~ifp->if_hwassist) {
ip->ip_sum = in_cksum(m0, ip->ip_hl << 2);
m0->m_pkthdr.csum_flags &= ~CSUM_IP;
}
m_clrprotoflags(m0); /* Avoid confusing lower layers. */
error = (*ifp->if_output)(ifp, m0, sintosa(&dst), NULL);
goto done;
}
/* Balk when DF bit is set or the interface didn't support TSO. */
if ((ip_off & IP_DF) || (m0->m_pkthdr.csum_flags & CSUM_TSO)) {
error = EMSGSIZE;
KMOD_IPSTAT_INC(ips_cantfrag);
if (r->rt != PF_DUPTO) {
icmp_error(m0, ICMP_UNREACH, ICMP_UNREACH_NEEDFRAG, 0,
ifp->if_mtu);
goto done;
} else
goto bad;
}
error = ip_fragment(ip, &m0, ifp->if_mtu, ifp->if_hwassist);
if (error)
goto bad;
for (; m0; m0 = m1) {
m1 = m0->m_nextpkt;
m0->m_nextpkt = NULL;
if (error == 0) {
m_clrprotoflags(m0);
error = (*ifp->if_output)(ifp, m0, sintosa(&dst), NULL);
} else
m_freem(m0);
}
if (error == 0)
KMOD_IPSTAT_INC(ips_fragmented);
done:
if (r->rt != PF_DUPTO)
*m = NULL;
return;
bad_locked:
if (s)
PF_STATE_UNLOCK(s);
bad:
m_freem(m0);
goto done;
}
#endif /* INET */
#ifdef INET6
static void
pf_route6(struct mbuf **m, struct pf_rule *r, int dir, struct ifnet *oifp,
struct pf_state *s, struct pf_pdesc *pd)
{
struct mbuf *m0;
struct sockaddr_in6 dst;
struct ip6_hdr *ip6;
struct ifnet *ifp = NULL;
struct pf_addr naddr;
struct pf_src_node *sn = NULL;
KASSERT(m && *m && r && oifp, ("%s: invalid parameters", __func__));
KASSERT(dir == PF_IN || dir == PF_OUT, ("%s: invalid direction",
__func__));
if ((pd->pf_mtag == NULL &&
((pd->pf_mtag = pf_get_mtag(*m)) == NULL)) ||
pd->pf_mtag->routed++ > 3) {
m0 = *m;
*m = NULL;
goto bad_locked;
}
if (r->rt == PF_DUPTO) {
if ((m0 = m_dup(*m, M_NOWAIT)) == NULL) {
if (s)
PF_STATE_UNLOCK(s);
return;
}
} else {
if ((r->rt == PF_REPLYTO) == (r->direction == dir)) {
if (s)
PF_STATE_UNLOCK(s);
return;
}
m0 = *m;
}
ip6 = mtod(m0, struct ip6_hdr *);
bzero(&dst, sizeof(dst));
dst.sin6_family = AF_INET6;
dst.sin6_len = sizeof(dst);
dst.sin6_addr = ip6->ip6_dst;
/* Cheat. XXX why only in the v6 case??? */
if (r->rt == PF_FASTROUTE) {
if (s)
PF_STATE_UNLOCK(s);
m0->m_flags |= M_SKIP_FIREWALL;
ip6_output(m0, NULL, NULL, 0, NULL, NULL, NULL);
return;
}
if (TAILQ_EMPTY(&r->rpool.list)) {
DPFPRINTF(PF_DEBUG_URGENT,
("%s: TAILQ_EMPTY(&r->rpool.list)\n", __func__));
goto bad_locked;
}
if (s == NULL) {
pf_map_addr(AF_INET6, r, (struct pf_addr *)&ip6->ip6_src,
&naddr, NULL, &sn);
if (!PF_AZERO(&naddr, AF_INET6))
PF_ACPY((struct pf_addr *)&dst.sin6_addr,
&naddr, AF_INET6);
ifp = r->rpool.cur->kif ? r->rpool.cur->kif->pfik_ifp : NULL;
} else {
if (!PF_AZERO(&s->rt_addr, AF_INET6))
PF_ACPY((struct pf_addr *)&dst.sin6_addr,
&s->rt_addr, AF_INET6);
ifp = s->rt_kif ? s->rt_kif->pfik_ifp : NULL;
}
if (s)
PF_STATE_UNLOCK(s);
if (ifp == NULL)
goto bad;
if (oifp != ifp) {
if (pf_test6(PF_FWD, ifp, &m0, NULL) != PF_PASS)
goto bad;
else if (m0 == NULL)
goto done;
if (m0->m_len < sizeof(struct ip6_hdr)) {
DPFPRINTF(PF_DEBUG_URGENT,
("%s: m0->m_len < sizeof(struct ip6_hdr)\n",
__func__));
goto bad;
}
ip6 = mtod(m0, struct ip6_hdr *);
}
if (ifp->if_flags & IFF_LOOPBACK)
m0->m_flags |= M_SKIP_FIREWALL;
/*
* If the packet is too large for the outgoing interface,
* send back an icmp6 error.
*/
if (IN6_IS_SCOPE_EMBED(&dst.sin6_addr))
dst.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
if ((u_long)m0->m_pkthdr.len <= ifp->if_mtu)
nd6_output(ifp, ifp, m0, &dst, NULL);
else {
in6_ifstat_inc(ifp, ifs6_in_toobig);
if (r->rt != PF_DUPTO)
icmp6_error(m0, ICMP6_PACKET_TOO_BIG, 0, ifp->if_mtu);
else
goto bad;
}
done:
if (r->rt != PF_DUPTO)
*m = NULL;
return;
bad_locked:
if (s)
PF_STATE_UNLOCK(s);
bad:
m_freem(m0);
goto done;
}
#endif /* INET6 */
/*
* FreeBSD supports cksum offloads for the following drivers.
* em(4), fxp(4), ixgb(4), lge(4), ndis(4), nge(4), re(4),
* ti(4), txp(4), xl(4)
*
* CSUM_DATA_VALID | CSUM_PSEUDO_HDR :
* network driver performed cksum including pseudo header, need to verify
* csum_data
* CSUM_DATA_VALID :
* network driver performed cksum, needs to additional pseudo header
* cksum computation with partial csum_data(i.e. lack of H/W support for
* pseudo header, for instance hme(4), sk(4) and possibly gem(4))
*
* After validating the cksum of packet, set both flag CSUM_DATA_VALID and
* CSUM_PSEUDO_HDR in order to avoid recomputation of the cksum in upper
* TCP/UDP layer.
* Also, set csum_data to 0xffff to force cksum validation.
*/
static int
pf_check_proto_cksum(struct mbuf *m, int off, int len, u_int8_t p, sa_family_t af)
{
u_int16_t sum = 0;
int hw_assist = 0;
struct ip *ip;
if (off < sizeof(struct ip) || len < sizeof(struct udphdr))
return (1);
if (m->m_pkthdr.len < off + len)
return (1);
switch (p) {
case IPPROTO_TCP:
if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) {
sum = m->m_pkthdr.csum_data;
} else {
ip = mtod(m, struct ip *);
sum = in_pseudo(ip->ip_src.s_addr,
ip->ip_dst.s_addr, htonl((u_short)len +
m->m_pkthdr.csum_data + IPPROTO_TCP));
}
sum ^= 0xffff;
++hw_assist;
}
break;
case IPPROTO_UDP:
if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID) {
if (m->m_pkthdr.csum_flags & CSUM_PSEUDO_HDR) {
sum = m->m_pkthdr.csum_data;
} else {
ip = mtod(m, struct ip *);
sum = in_pseudo(ip->ip_src.s_addr,
ip->ip_dst.s_addr, htonl((u_short)len +
m->m_pkthdr.csum_data + IPPROTO_UDP));
}
sum ^= 0xffff;
++hw_assist;
}
break;
case IPPROTO_ICMP:
#ifdef INET6
case IPPROTO_ICMPV6:
#endif /* INET6 */
break;
default:
return (1);
}
if (!hw_assist) {
switch (af) {
case AF_INET:
if (p == IPPROTO_ICMP) {
if (m->m_len < off)
return (1);
m->m_data += off;
m->m_len -= off;
sum = in_cksum(m, len);
m->m_data -= off;
m->m_len += off;
} else {
if (m->m_len < sizeof(struct ip))
return (1);
sum = in4_cksum(m, p, off, len);
}
break;
#ifdef INET6
case AF_INET6:
if (m->m_len < sizeof(struct ip6_hdr))
return (1);
sum = in6_cksum(m, p, off, len);
break;
#endif /* INET6 */
default:
return (1);
}
}
if (sum) {
switch (p) {
case IPPROTO_TCP:
{
KMOD_TCPSTAT_INC(tcps_rcvbadsum);
break;
}
case IPPROTO_UDP:
{
KMOD_UDPSTAT_INC(udps_badsum);
break;
}
#ifdef INET
case IPPROTO_ICMP:
{
KMOD_ICMPSTAT_INC(icps_checksum);
break;
}
#endif
#ifdef INET6
case IPPROTO_ICMPV6:
{
KMOD_ICMP6STAT_INC(icp6s_checksum);
break;
}
#endif /* INET6 */
}
return (1);
} else {
if (p == IPPROTO_TCP || p == IPPROTO_UDP) {
m->m_pkthdr.csum_flags |=
(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
m->m_pkthdr.csum_data = 0xffff;
}
}
return (0);
}
#ifdef INET
int
pf_test(int dir, struct ifnet *ifp, struct mbuf **m0, struct inpcb *inp)
{
struct pfi_kif *kif;
u_short action, reason = 0, log = 0;
struct mbuf *m = *m0;
struct ip *h = NULL;
struct m_tag *ipfwtag;
struct pf_rule *a = NULL, *r = &V_pf_default_rule, *tr, *nr;
struct pf_state *s = NULL;
struct pf_ruleset *ruleset = NULL;
struct pf_pdesc pd;
int off, dirndx, pqid = 0;
M_ASSERTPKTHDR(m);
if (!V_pf_status.running)
return (PF_PASS);
memset(&pd, 0, sizeof(pd));
kif = (struct pfi_kif *)ifp->if_pf_kif;
if (kif == NULL) {
DPFPRINTF(PF_DEBUG_URGENT,
("pf_test: kif == NULL, if_xname %s\n", ifp->if_xname));
return (PF_DROP);
}
if (kif->pfik_flags & PFI_IFLAG_SKIP)
return (PF_PASS);
if (m->m_flags & M_SKIP_FIREWALL)
return (PF_PASS);
pd.pf_mtag = pf_find_mtag(m);
PF_RULES_RLOCK();
if (ip_divert_ptr != NULL &&
((ipfwtag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL)) != NULL)) {
struct ipfw_rule_ref *rr = (struct ipfw_rule_ref *)(ipfwtag+1);
if (rr->info & IPFW_IS_DIVERT && rr->rulenum == 0) {
if (pd.pf_mtag == NULL &&
((pd.pf_mtag = pf_get_mtag(m)) == NULL)) {
action = PF_DROP;
goto done;
}
pd.pf_mtag->flags |= PF_PACKET_LOOPED;
m_tag_delete(m, ipfwtag);
}
if (pd.pf_mtag && pd.pf_mtag->flags & PF_FASTFWD_OURS_PRESENT) {
m->m_flags |= M_FASTFWD_OURS;
pd.pf_mtag->flags &= ~PF_FASTFWD_OURS_PRESENT;
}
} else if (pf_normalize_ip(m0, dir, kif, &reason, &pd) != PF_PASS) {
/* We do IP header normalization and packet reassembly here */
action = PF_DROP;
goto done;
}
m = *m0; /* pf_normalize messes with m0 */
h = mtod(m, struct ip *);
off = h->ip_hl << 2;
if (off < (int)sizeof(struct ip)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_SHORT);
log = 1;
goto done;
}
pd.src = (struct pf_addr *)&h->ip_src;
pd.dst = (struct pf_addr *)&h->ip_dst;
pd.sport = pd.dport = NULL;
pd.ip_sum = &h->ip_sum;
pd.proto_sum = NULL;
pd.proto = h->ip_p;
pd.dir = dir;
pd.sidx = (dir == PF_IN) ? 0 : 1;
pd.didx = (dir == PF_IN) ? 1 : 0;
pd.af = AF_INET;
pd.tos = h->ip_tos;
pd.tot_len = ntohs(h->ip_len);
/* handle fragments that didn't get reassembled by normalization */
if (h->ip_off & htons(IP_MF | IP_OFFMASK)) {
action = pf_test_fragment(&r, dir, kif, m, h,
&pd, &a, &ruleset);
goto done;
}
switch (h->ip_p) {
case IPPROTO_TCP: {
struct tcphdr th;
pd.hdr.tcp = &th;
if (!pf_pull_hdr(m, off, &th, sizeof(th),
&action, &reason, AF_INET)) {
log = action != PF_PASS;
goto done;
}
pd.p_len = pd.tot_len - off - (th.th_off << 2);
if ((th.th_flags & TH_ACK) && pd.p_len == 0)
pqid = 1;
action = pf_normalize_tcp(dir, kif, m, 0, off, h, &pd);
if (action == PF_DROP)
goto done;
action = pf_test_state_tcp(&s, dir, kif, m, off, h, &pd,
&reason);
if (action == PF_PASS) {
if (pfsync_update_state_ptr != NULL)
pfsync_update_state_ptr(s);
r = s->rule.ptr;
a = s->anchor.ptr;
log = s->log;
} else if (s == NULL)
action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
&a, &ruleset, inp);
break;
}
case IPPROTO_UDP: {
struct udphdr uh;
pd.hdr.udp = &uh;
if (!pf_pull_hdr(m, off, &uh, sizeof(uh),
&action, &reason, AF_INET)) {
log = action != PF_PASS;
goto done;
}
if (uh.uh_dport == 0 ||
ntohs(uh.uh_ulen) > m->m_pkthdr.len - off ||
ntohs(uh.uh_ulen) < sizeof(struct udphdr)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_SHORT);
goto done;
}
action = pf_test_state_udp(&s, dir, kif, m, off, h, &pd);
if (action == PF_PASS) {
if (pfsync_update_state_ptr != NULL)
pfsync_update_state_ptr(s);
r = s->rule.ptr;
a = s->anchor.ptr;
log = s->log;
} else if (s == NULL)
action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
&a, &ruleset, inp);
break;
}
case IPPROTO_ICMP: {
struct icmp ih;
pd.hdr.icmp = &ih;
if (!pf_pull_hdr(m, off, &ih, ICMP_MINLEN,
&action, &reason, AF_INET)) {
log = action != PF_PASS;
goto done;
}
action = pf_test_state_icmp(&s, dir, kif, m, off, h, &pd,
&reason);
if (action == PF_PASS) {
if (pfsync_update_state_ptr != NULL)
pfsync_update_state_ptr(s);
r = s->rule.ptr;
a = s->anchor.ptr;
log = s->log;
} else if (s == NULL)
action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
&a, &ruleset, inp);
break;
}
#ifdef INET6
case IPPROTO_ICMPV6: {
action = PF_DROP;
DPFPRINTF(PF_DEBUG_MISC,
("pf: dropping IPv4 packet with ICMPv6 payload\n"));
goto done;
}
#endif
default:
action = pf_test_state_other(&s, dir, kif, m, &pd);
if (action == PF_PASS) {
if (pfsync_update_state_ptr != NULL)
pfsync_update_state_ptr(s);
r = s->rule.ptr;
a = s->anchor.ptr;
log = s->log;
} else if (s == NULL)
action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
&a, &ruleset, inp);
break;
}
done:
PF_RULES_RUNLOCK();
if (action == PF_PASS && h->ip_hl > 5 &&
!((s && s->state_flags & PFSTATE_ALLOWOPTS) || r->allow_opts)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_IPOPTIONS);
log = 1;
DPFPRINTF(PF_DEBUG_MISC,
("pf: dropping packet with ip options\n"));
}
if (s && s->tag > 0 && pf_tag_packet(m, &pd, s->tag)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_MEMORY);
}
if (r->rtableid >= 0)
M_SETFIB(m, r->rtableid);
#ifdef ALTQ
if (action == PF_PASS && r->qid) {
if (pd.pf_mtag == NULL &&
((pd.pf_mtag = pf_get_mtag(m)) == NULL)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_MEMORY);
}
if (pqid || (pd.tos & IPTOS_LOWDELAY))
pd.pf_mtag->qid = r->pqid;
else
pd.pf_mtag->qid = r->qid;
/* add hints for ecn */
pd.pf_mtag->hdr = h;
}
#endif /* ALTQ */
/*
* connections redirected to loopback should not match sockets
* bound specifically to loopback due to security implications,
* see tcp_input() and in_pcblookup_listen().
*/
if (dir == PF_IN && action == PF_PASS && (pd.proto == IPPROTO_TCP ||
pd.proto == IPPROTO_UDP) && s != NULL && s->nat_rule.ptr != NULL &&
(s->nat_rule.ptr->action == PF_RDR ||
s->nat_rule.ptr->action == PF_BINAT) &&
(ntohl(pd.dst->v4.s_addr) >> IN_CLASSA_NSHIFT) == IN_LOOPBACKNET)
m->m_flags |= M_SKIP_FIREWALL;
if (action == PF_PASS && r->divert.port && ip_divert_ptr != NULL &&
!PACKET_LOOPED(&pd)) {
ipfwtag = m_tag_alloc(MTAG_IPFW_RULE, 0,
sizeof(struct ipfw_rule_ref), M_NOWAIT | M_ZERO);
if (ipfwtag != NULL) {
((struct ipfw_rule_ref *)(ipfwtag+1))->info =
ntohs(r->divert.port);
((struct ipfw_rule_ref *)(ipfwtag+1))->rulenum = dir;
if (s)
PF_STATE_UNLOCK(s);
m_tag_prepend(m, ipfwtag);
if (m->m_flags & M_FASTFWD_OURS) {
if (pd.pf_mtag == NULL &&
((pd.pf_mtag = pf_get_mtag(m)) == NULL)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_MEMORY);
log = 1;
DPFPRINTF(PF_DEBUG_MISC,
("pf: failed to allocate tag\n"));
}
pd.pf_mtag->flags |= PF_FASTFWD_OURS_PRESENT;
m->m_flags &= ~M_FASTFWD_OURS;
}
ip_divert_ptr(*m0, dir == PF_IN ? DIR_IN : DIR_OUT);
*m0 = NULL;
return (action);
} else {
/* XXX: ipfw has the same behaviour! */
action = PF_DROP;
REASON_SET(&reason, PFRES_MEMORY);
log = 1;
DPFPRINTF(PF_DEBUG_MISC,
("pf: failed to allocate divert tag\n"));
}
}
if (log) {
struct pf_rule *lr;
if (s != NULL && s->nat_rule.ptr != NULL &&
s->nat_rule.ptr->log & PF_LOG_ALL)
lr = s->nat_rule.ptr;
else
lr = r;
PFLOG_PACKET(kif, m, AF_INET, dir, reason, lr, a, ruleset, &pd,
(s == NULL));
}
kif->pfik_bytes[0][dir == PF_OUT][action != PF_PASS] += pd.tot_len;
kif->pfik_packets[0][dir == PF_OUT][action != PF_PASS]++;
if (action == PF_PASS || r->action == PF_DROP) {
dirndx = (dir == PF_OUT);
r->packets[dirndx]++;
r->bytes[dirndx] += pd.tot_len;
if (a != NULL) {
a->packets[dirndx]++;
a->bytes[dirndx] += pd.tot_len;
}
if (s != NULL) {
if (s->nat_rule.ptr != NULL) {
s->nat_rule.ptr->packets[dirndx]++;
s->nat_rule.ptr->bytes[dirndx] += pd.tot_len;
}
if (s->src_node != NULL) {
s->src_node->packets[dirndx]++;
s->src_node->bytes[dirndx] += pd.tot_len;
}
if (s->nat_src_node != NULL) {
s->nat_src_node->packets[dirndx]++;
s->nat_src_node->bytes[dirndx] += pd.tot_len;
}
dirndx = (dir == s->direction) ? 0 : 1;
s->packets[dirndx]++;
s->bytes[dirndx] += pd.tot_len;
}
tr = r;
nr = (s != NULL) ? s->nat_rule.ptr : pd.nat_rule;
if (nr != NULL && r == &V_pf_default_rule)
tr = nr;
if (tr->src.addr.type == PF_ADDR_TABLE)
pfr_update_stats(tr->src.addr.p.tbl,
(s == NULL) ? pd.src :
&s->key[(s->direction == PF_IN)]->
addr[(s->direction == PF_OUT)],
pd.af, pd.tot_len, dir == PF_OUT,
r->action == PF_PASS, tr->src.neg);
if (tr->dst.addr.type == PF_ADDR_TABLE)
pfr_update_stats(tr->dst.addr.p.tbl,
(s == NULL) ? pd.dst :
&s->key[(s->direction == PF_IN)]->
addr[(s->direction == PF_IN)],
pd.af, pd.tot_len, dir == PF_OUT,
r->action == PF_PASS, tr->dst.neg);
}
switch (action) {
case PF_SYNPROXY_DROP:
m_freem(*m0);
case PF_DEFER:
*m0 = NULL;
action = PF_PASS;
break;
case PF_DROP:
m_freem(*m0);
*m0 = NULL;
break;
default:
/* pf_route() returns unlocked. */
if (r->rt) {
pf_route(m0, r, dir, kif->pfik_ifp, s, &pd);
return (action);
}
break;
}
if (s)
PF_STATE_UNLOCK(s);
return (action);
}
#endif /* INET */
#ifdef INET6
int
pf_test6(int dir, struct ifnet *ifp, struct mbuf **m0, struct inpcb *inp)
{
struct pfi_kif *kif;
u_short action, reason = 0, log = 0;
struct mbuf *m = *m0, *n = NULL;
struct m_tag *mtag;
struct ip6_hdr *h = NULL;
struct pf_rule *a = NULL, *r = &V_pf_default_rule, *tr, *nr;
struct pf_state *s = NULL;
struct pf_ruleset *ruleset = NULL;
struct pf_pdesc pd;
int off, terminal = 0, dirndx, rh_cnt = 0;
int fwdir = dir;
M_ASSERTPKTHDR(m);
if (ifp != m->m_pkthdr.rcvif)
fwdir = PF_FWD;
if (!V_pf_status.running)
return (PF_PASS);
memset(&pd, 0, sizeof(pd));
pd.pf_mtag = pf_find_mtag(m);
if (pd.pf_mtag && pd.pf_mtag->flags & PF_TAG_GENERATED)
return (PF_PASS);
kif = (struct pfi_kif *)ifp->if_pf_kif;
if (kif == NULL) {
DPFPRINTF(PF_DEBUG_URGENT,
("pf_test6: kif == NULL, if_xname %s\n", ifp->if_xname));
return (PF_DROP);
}
if (kif->pfik_flags & PFI_IFLAG_SKIP)
return (PF_PASS);
if (m->m_flags & M_SKIP_FIREWALL)
return (PF_PASS);
PF_RULES_RLOCK();
/* We do IP header normalization and packet reassembly here */
if (pf_normalize_ip6(m0, dir, kif, &reason, &pd) != PF_PASS) {
action = PF_DROP;
goto done;
}
m = *m0; /* pf_normalize messes with m0 */
h = mtod(m, struct ip6_hdr *);
#if 1
/*
* we do not support jumbogram yet. if we keep going, zero ip6_plen
* will do something bad, so drop the packet for now.
*/
if (htons(h->ip6_plen) == 0) {
action = PF_DROP;
REASON_SET(&reason, PFRES_NORM); /*XXX*/
goto done;
}
#endif
pd.src = (struct pf_addr *)&h->ip6_src;
pd.dst = (struct pf_addr *)&h->ip6_dst;
pd.sport = pd.dport = NULL;
pd.ip_sum = NULL;
pd.proto_sum = NULL;
pd.dir = dir;
pd.sidx = (dir == PF_IN) ? 0 : 1;
pd.didx = (dir == PF_IN) ? 1 : 0;
pd.af = AF_INET6;
pd.tos = 0;
pd.tot_len = ntohs(h->ip6_plen) + sizeof(struct ip6_hdr);
off = ((caddr_t)h - m->m_data) + sizeof(struct ip6_hdr);
pd.proto = h->ip6_nxt;
do {
switch (pd.proto) {
case IPPROTO_FRAGMENT:
action = pf_test_fragment(&r, dir, kif, m, h,
&pd, &a, &ruleset);
if (action == PF_DROP)
REASON_SET(&reason, PFRES_FRAG);
goto done;
case IPPROTO_ROUTING: {
struct ip6_rthdr rthdr;
if (rh_cnt++) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: IPv6 more than one rthdr\n"));
action = PF_DROP;
REASON_SET(&reason, PFRES_IPOPTIONS);
log = 1;
goto done;
}
if (!pf_pull_hdr(m, off, &rthdr, sizeof(rthdr), NULL,
&reason, pd.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: IPv6 short rthdr\n"));
action = PF_DROP;
REASON_SET(&reason, PFRES_SHORT);
log = 1;
goto done;
}
if (rthdr.ip6r_type == IPV6_RTHDR_TYPE_0) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: IPv6 rthdr0\n"));
action = PF_DROP;
REASON_SET(&reason, PFRES_IPOPTIONS);
log = 1;
goto done;
}
/* FALLTHROUGH */
}
case IPPROTO_AH:
case IPPROTO_HOPOPTS:
case IPPROTO_DSTOPTS: {
/* get next header and header length */
struct ip6_ext opt6;
if (!pf_pull_hdr(m, off, &opt6, sizeof(opt6),
NULL, &reason, pd.af)) {
DPFPRINTF(PF_DEBUG_MISC,
("pf: IPv6 short opt\n"));
action = PF_DROP;
log = 1;
goto done;
}
if (pd.proto == IPPROTO_AH)
off += (opt6.ip6e_len + 2) * 4;
else
off += (opt6.ip6e_len + 1) * 8;
pd.proto = opt6.ip6e_nxt;
/* goto the next header */
break;
}
default:
terminal++;
break;
}
} while (!terminal);
/* if there's no routing header, use unmodified mbuf for checksumming */
if (!n)
n = m;
switch (pd.proto) {
case IPPROTO_TCP: {
struct tcphdr th;
pd.hdr.tcp = &th;
if (!pf_pull_hdr(m, off, &th, sizeof(th),
&action, &reason, AF_INET6)) {
log = action != PF_PASS;
goto done;
}
pd.p_len = pd.tot_len - off - (th.th_off << 2);
action = pf_normalize_tcp(dir, kif, m, 0, off, h, &pd);
if (action == PF_DROP)
goto done;
action = pf_test_state_tcp(&s, dir, kif, m, off, h, &pd,
&reason);
if (action == PF_PASS) {
if (pfsync_update_state_ptr != NULL)
pfsync_update_state_ptr(s);
r = s->rule.ptr;
a = s->anchor.ptr;
log = s->log;
} else if (s == NULL)
action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
&a, &ruleset, inp);
break;
}
case IPPROTO_UDP: {
struct udphdr uh;
pd.hdr.udp = &uh;
if (!pf_pull_hdr(m, off, &uh, sizeof(uh),
&action, &reason, AF_INET6)) {
log = action != PF_PASS;
goto done;
}
if (uh.uh_dport == 0 ||
ntohs(uh.uh_ulen) > m->m_pkthdr.len - off ||
ntohs(uh.uh_ulen) < sizeof(struct udphdr)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_SHORT);
goto done;
}
action = pf_test_state_udp(&s, dir, kif, m, off, h, &pd);
if (action == PF_PASS) {
if (pfsync_update_state_ptr != NULL)
pfsync_update_state_ptr(s);
r = s->rule.ptr;
a = s->anchor.ptr;
log = s->log;
} else if (s == NULL)
action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
&a, &ruleset, inp);
break;
}
case IPPROTO_ICMP: {
action = PF_DROP;
DPFPRINTF(PF_DEBUG_MISC,
("pf: dropping IPv6 packet with ICMPv4 payload\n"));
goto done;
}
case IPPROTO_ICMPV6: {
struct icmp6_hdr ih;
pd.hdr.icmp6 = &ih;
if (!pf_pull_hdr(m, off, &ih, sizeof(ih),
&action, &reason, AF_INET6)) {
log = action != PF_PASS;
goto done;
}
action = pf_test_state_icmp(&s, dir, kif,
m, off, h, &pd, &reason);
if (action == PF_PASS) {
if (pfsync_update_state_ptr != NULL)
pfsync_update_state_ptr(s);
r = s->rule.ptr;
a = s->anchor.ptr;
log = s->log;
} else if (s == NULL)
action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
&a, &ruleset, inp);
break;
}
default:
action = pf_test_state_other(&s, dir, kif, m, &pd);
if (action == PF_PASS) {
if (pfsync_update_state_ptr != NULL)
pfsync_update_state_ptr(s);
r = s->rule.ptr;
a = s->anchor.ptr;
log = s->log;
} else if (s == NULL)
action = pf_test_rule(&r, &s, dir, kif, m, off, &pd,
&a, &ruleset, inp);
break;
}
done:
PF_RULES_RUNLOCK();
if (n != m) {
m_freem(n);
n = NULL;
}
/* handle dangerous IPv6 extension headers. */
if (action == PF_PASS && rh_cnt &&
!((s && s->state_flags & PFSTATE_ALLOWOPTS) || r->allow_opts)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_IPOPTIONS);
log = 1;
DPFPRINTF(PF_DEBUG_MISC,
("pf: dropping packet with dangerous v6 headers\n"));
}
if (s && s->tag > 0 && pf_tag_packet(m, &pd, s->tag)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_MEMORY);
}
if (r->rtableid >= 0)
M_SETFIB(m, r->rtableid);
#ifdef ALTQ
if (action == PF_PASS && r->qid) {
if (pd.pf_mtag == NULL &&
((pd.pf_mtag = pf_get_mtag(m)) == NULL)) {
action = PF_DROP;
REASON_SET(&reason, PFRES_MEMORY);
}
if (pd.tos & IPTOS_LOWDELAY)
pd.pf_mtag->qid = r->pqid;
else
pd.pf_mtag->qid = r->qid;
/* add hints for ecn */
pd.pf_mtag->hdr = h;
}
#endif /* ALTQ */
if (dir == PF_IN && action == PF_PASS && (pd.proto == IPPROTO_TCP ||
pd.proto == IPPROTO_UDP) && s != NULL && s->nat_rule.ptr != NULL &&
(s->nat_rule.ptr->action == PF_RDR ||
s->nat_rule.ptr->action == PF_BINAT) &&
IN6_IS_ADDR_LOOPBACK(&pd.dst->v6))
m->m_flags |= M_SKIP_FIREWALL;
/* XXX: Anybody working on it?! */
if (r->divert.port)
printf("pf: divert(9) is not supported for IPv6\n");
if (log) {
struct pf_rule *lr;
if (s != NULL && s->nat_rule.ptr != NULL &&
s->nat_rule.ptr->log & PF_LOG_ALL)
lr = s->nat_rule.ptr;
else
lr = r;
PFLOG_PACKET(kif, m, AF_INET6, dir, reason, lr, a, ruleset,
&pd, (s == NULL));
}
kif->pfik_bytes[1][dir == PF_OUT][action != PF_PASS] += pd.tot_len;
kif->pfik_packets[1][dir == PF_OUT][action != PF_PASS]++;
if (action == PF_PASS || r->action == PF_DROP) {
dirndx = (dir == PF_OUT);
r->packets[dirndx]++;
r->bytes[dirndx] += pd.tot_len;
if (a != NULL) {
a->packets[dirndx]++;
a->bytes[dirndx] += pd.tot_len;
}
if (s != NULL) {
if (s->nat_rule.ptr != NULL) {
s->nat_rule.ptr->packets[dirndx]++;
s->nat_rule.ptr->bytes[dirndx] += pd.tot_len;
}
if (s->src_node != NULL) {
s->src_node->packets[dirndx]++;
s->src_node->bytes[dirndx] += pd.tot_len;
}
if (s->nat_src_node != NULL) {
s->nat_src_node->packets[dirndx]++;
s->nat_src_node->bytes[dirndx] += pd.tot_len;
}
dirndx = (dir == s->direction) ? 0 : 1;
s->packets[dirndx]++;
s->bytes[dirndx] += pd.tot_len;
}
tr = r;
nr = (s != NULL) ? s->nat_rule.ptr : pd.nat_rule;
if (nr != NULL && r == &V_pf_default_rule)
tr = nr;
if (tr->src.addr.type == PF_ADDR_TABLE)
pfr_update_stats(tr->src.addr.p.tbl,
(s == NULL) ? pd.src :
&s->key[(s->direction == PF_IN)]->addr[0],
pd.af, pd.tot_len, dir == PF_OUT,
r->action == PF_PASS, tr->src.neg);
if (tr->dst.addr.type == PF_ADDR_TABLE)
pfr_update_stats(tr->dst.addr.p.tbl,
(s == NULL) ? pd.dst :
&s->key[(s->direction == PF_IN)]->addr[1],
pd.af, pd.tot_len, dir == PF_OUT,
r->action == PF_PASS, tr->dst.neg);
}
switch (action) {
case PF_SYNPROXY_DROP:
m_freem(*m0);
case PF_DEFER:
*m0 = NULL;
action = PF_PASS;
break;
case PF_DROP:
m_freem(*m0);
*m0 = NULL;
break;
default:
/* pf_route6() returns unlocked. */
if (r->rt) {
pf_route6(m0, r, dir, kif->pfik_ifp, s, &pd);
return (action);
}
break;
}
if (s)
PF_STATE_UNLOCK(s);
/* If reassembled packet passed, create new fragments. */
if (action == PF_PASS && *m0 && fwdir == PF_FWD &&
(mtag = m_tag_find(m, PF_REASSEMBLED, NULL)) != NULL)
action = pf_refragment6(ifp, m0, mtag);
return (action);
}
#endif /* INET6 */
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