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freebsd-dev/sys/netpfil/ipfw/ip_fw_dynamic.c
Gleb Smirnoff b7795b6746 - Add more flags to ip_fw_args. At this changeset only IPFW_ARGS_IN and 
IPFW_ARGS_OUT are utilized. They are intented to substitute the "dir"
  parameter that is often passes together with args.
- Rename ip_fw_args.oif to ifp and now it is set to either input or
  output interface, depending on IPFW_ARGS_IN/OUT bit set.
2019-03-14 22:28:50 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2017-2018 Yandex LLC
* Copyright (c) 2017-2018 Andrey V. Elsukov <ae@FreeBSD.org>
* Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipfw.h"
#ifndef INET
#error IPFIREWALL requires INET.
#endif /* INET */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/hash.h>
#include <sys/mbuf.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/pcpu.h>
#include <sys/queue.h>
#include <sys/rmlock.h>
#include <sys/smp.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/ip_fw.h>
#include <netinet/tcp_var.h>
#include <netinet/udp.h>
#include <netinet/ip6.h> /* IN6_ARE_ADDR_EQUAL */
#ifdef INET6
#include <netinet6/in6_var.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#endif
#include <netpfil/ipfw/ip_fw_private.h>
#include <machine/in_cksum.h> /* XXX for in_cksum */
#ifdef MAC
#include <security/mac/mac_framework.h>
#endif
/*
* Description of dynamic states.
*
* Dynamic states are stored in lists accessed through a hash tables
* whose size is curr_dyn_buckets. This value can be modified through
* the sysctl variable dyn_buckets.
*
* Currently there are four tables: dyn_ipv4, dyn_ipv6, dyn_ipv4_parent,
* and dyn_ipv6_parent.
*
* When a packet is received, its address fields hashed, then matched
* against the entries in the corresponding list by addr_type.
* Dynamic states can be used for different purposes:
* + stateful rules;
* + enforcing limits on the number of sessions;
* + in-kernel NAT (not implemented yet)
*
* The lifetime of dynamic states is regulated by dyn_*_lifetime,
* measured in seconds and depending on the flags.
*
* The total number of dynamic states is equal to UMA zone items count.
* The max number of dynamic states is dyn_max. When we reach
* the maximum number of rules we do not create anymore. This is
* done to avoid consuming too much memory, but also too much
* time when searching on each packet (ideally, we should try instead
* to put a limit on the length of the list on each bucket...).
*
* Each state holds a pointer to the parent ipfw rule so we know what
* action to perform. Dynamic rules are removed when the parent rule is
* deleted.
*
* There are some limitations with dynamic rules -- we do not
* obey the 'randomized match', and we do not do multiple
* passes through the firewall. XXX check the latter!!!
*/
/* By default use jenkins hash function */
#define IPFIREWALL_JENKINSHASH
#define DYN_COUNTER_INC(d, dir, pktlen) do { \
(d)->pcnt_ ## dir++; \
(d)->bcnt_ ## dir += pktlen; \
} while (0)
#define DYN_REFERENCED 0x01
/*
* DYN_REFERENCED flag is used to show that state keeps reference to named
* object, and this reference should be released when state becomes expired.
*/
struct dyn_data {
void *parent; /* pointer to parent rule */
uint32_t chain_id; /* cached ruleset id */
uint32_t f_pos; /* cached rule index */
uint32_t hashval; /* hash value used for hash resize */
uint16_t fibnum; /* fib used to send keepalives */
uint8_t _pad[3];
uint8_t flags; /* internal flags */
uint16_t rulenum; /* parent rule number */
uint32_t ruleid; /* parent rule id */
uint32_t state; /* TCP session state and flags */
uint32_t ack_fwd; /* most recent ACKs in forward */
uint32_t ack_rev; /* and reverse direction (used */
/* to generate keepalives) */
uint32_t sync; /* synchronization time */
uint32_t expire; /* expire time */
uint64_t pcnt_fwd; /* bytes counter in forward */
uint64_t bcnt_fwd; /* packets counter in forward */
uint64_t pcnt_rev; /* bytes counter in reverse */
uint64_t bcnt_rev; /* packets counter in reverse */
};
#define DPARENT_COUNT_DEC(p) do { \
MPASS(p->count > 0); \
ck_pr_dec_32(&(p)->count); \
} while (0)
#define DPARENT_COUNT_INC(p) ck_pr_inc_32(&(p)->count)
#define DPARENT_COUNT(p) ck_pr_load_32(&(p)->count)
struct dyn_parent {
void *parent; /* pointer to parent rule */
uint32_t count; /* number of linked states */
uint8_t _pad[2];
uint16_t rulenum; /* parent rule number */
uint32_t ruleid; /* parent rule id */
uint32_t hashval; /* hash value used for hash resize */
uint32_t expire; /* expire time */
};
struct dyn_ipv4_state {
uint8_t type; /* State type */
uint8_t proto; /* UL Protocol */
uint16_t kidx; /* named object index */
uint16_t sport, dport; /* ULP source and destination ports */
in_addr_t src, dst; /* IPv4 source and destination */
union {
struct dyn_data *data;
struct dyn_parent *limit;
};
CK_SLIST_ENTRY(dyn_ipv4_state) entry;
SLIST_ENTRY(dyn_ipv4_state) expired;
};
CK_SLIST_HEAD(dyn_ipv4ck_slist, dyn_ipv4_state);
VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4);
VNET_DEFINE_STATIC(struct dyn_ipv4ck_slist *, dyn_ipv4_parent);
SLIST_HEAD(dyn_ipv4_slist, dyn_ipv4_state);
VNET_DEFINE_STATIC(struct dyn_ipv4_slist, dyn_expired_ipv4);
#define V_dyn_ipv4 VNET(dyn_ipv4)
#define V_dyn_ipv4_parent VNET(dyn_ipv4_parent)
#define V_dyn_expired_ipv4 VNET(dyn_expired_ipv4)
#ifdef INET6
struct dyn_ipv6_state {
uint8_t type; /* State type */
uint8_t proto; /* UL Protocol */
uint16_t kidx; /* named object index */
uint16_t sport, dport; /* ULP source and destination ports */
struct in6_addr src, dst; /* IPv6 source and destination */
uint32_t zoneid; /* IPv6 scope zone id */
union {
struct dyn_data *data;
struct dyn_parent *limit;
};
CK_SLIST_ENTRY(dyn_ipv6_state) entry;
SLIST_ENTRY(dyn_ipv6_state) expired;
};
CK_SLIST_HEAD(dyn_ipv6ck_slist, dyn_ipv6_state);
VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6);
VNET_DEFINE_STATIC(struct dyn_ipv6ck_slist *, dyn_ipv6_parent);
SLIST_HEAD(dyn_ipv6_slist, dyn_ipv6_state);
VNET_DEFINE_STATIC(struct dyn_ipv6_slist, dyn_expired_ipv6);
#define V_dyn_ipv6 VNET(dyn_ipv6)
#define V_dyn_ipv6_parent VNET(dyn_ipv6_parent)
#define V_dyn_expired_ipv6 VNET(dyn_expired_ipv6)
#endif /* INET6 */
/*
* Per-CPU pointer indicates that specified state is currently in use
* and must not be reclaimed by expiration callout.
*/
static void **dyn_hp_cache;
DPCPU_DEFINE_STATIC(void *, dyn_hp);
#define DYNSTATE_GET(cpu) ck_pr_load_ptr(DPCPU_ID_PTR((cpu), dyn_hp))
#define DYNSTATE_PROTECT(v) ck_pr_store_ptr(DPCPU_PTR(dyn_hp), (v))
#define DYNSTATE_RELEASE() DYNSTATE_PROTECT(NULL)
#define DYNSTATE_CRITICAL_ENTER() critical_enter()
#define DYNSTATE_CRITICAL_EXIT() do { \
DYNSTATE_RELEASE(); \
critical_exit(); \
} while (0);
/*
* We keep two version numbers, one is updated when new entry added to
* the list. Second is updated when an entry deleted from the list.
* Versions are updated under bucket lock.
*
* Bucket "add" version number is used to know, that in the time between
* state lookup (i.e. ipfw_dyn_lookup_state()) and the followed state
* creation (i.e. ipfw_dyn_install_state()) another concurrent thread did
* not install some state in this bucket. Using this info we can avoid
* additional state lookup, because we are sure that we will not install
* the state twice.
*
* Also doing the tracking of bucket "del" version during lookup we can
* be sure, that state entry was not unlinked and freed in time between
* we read the state pointer and protect it with hazard pointer.
*
* An entry unlinked from CK list keeps unchanged until it is freed.
* Unlinked entries are linked into expired lists using "expired" field.
*/
/*
* dyn_expire_lock is used to protect access to dyn_expired_xxx lists.
* dyn_bucket_lock is used to get write access to lists in specific bucket.
* Currently one dyn_bucket_lock is used for all ipv4, ipv4_parent, ipv6,
* and ipv6_parent lists.
*/
VNET_DEFINE_STATIC(struct mtx, dyn_expire_lock);
VNET_DEFINE_STATIC(struct mtx *, dyn_bucket_lock);
#define V_dyn_expire_lock VNET(dyn_expire_lock)
#define V_dyn_bucket_lock VNET(dyn_bucket_lock)
/*
* Bucket's add/delete generation versions.
*/
VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_add);
VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_del);
VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_add);
VNET_DEFINE_STATIC(uint32_t *, dyn_ipv4_parent_del);
#define V_dyn_ipv4_add VNET(dyn_ipv4_add)
#define V_dyn_ipv4_del VNET(dyn_ipv4_del)
#define V_dyn_ipv4_parent_add VNET(dyn_ipv4_parent_add)
#define V_dyn_ipv4_parent_del VNET(dyn_ipv4_parent_del)
#ifdef INET6
VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_add);
VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_del);
VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_add);
VNET_DEFINE_STATIC(uint32_t *, dyn_ipv6_parent_del);
#define V_dyn_ipv6_add VNET(dyn_ipv6_add)
#define V_dyn_ipv6_del VNET(dyn_ipv6_del)
#define V_dyn_ipv6_parent_add VNET(dyn_ipv6_parent_add)
#define V_dyn_ipv6_parent_del VNET(dyn_ipv6_parent_del)
#endif /* INET6 */
#define DYN_BUCKET(h, b) ((h) & (b - 1))
#define DYN_BUCKET_VERSION(b, v) ck_pr_load_32(&V_dyn_ ## v[(b)])
#define DYN_BUCKET_VERSION_BUMP(b, v) ck_pr_inc_32(&V_dyn_ ## v[(b)])
#define DYN_BUCKET_LOCK_INIT(lock, b) \
mtx_init(&lock[(b)], "IPFW dynamic bucket", NULL, MTX_DEF)
#define DYN_BUCKET_LOCK_DESTROY(lock, b) mtx_destroy(&lock[(b)])
#define DYN_BUCKET_LOCK(b) mtx_lock(&V_dyn_bucket_lock[(b)])
#define DYN_BUCKET_UNLOCK(b) mtx_unlock(&V_dyn_bucket_lock[(b)])
#define DYN_BUCKET_ASSERT(b) mtx_assert(&V_dyn_bucket_lock[(b)], MA_OWNED)
#define DYN_EXPIRED_LOCK_INIT() \
mtx_init(&V_dyn_expire_lock, "IPFW expired states list", NULL, MTX_DEF)
#define DYN_EXPIRED_LOCK_DESTROY() mtx_destroy(&V_dyn_expire_lock)
#define DYN_EXPIRED_LOCK() mtx_lock(&V_dyn_expire_lock)
#define DYN_EXPIRED_UNLOCK() mtx_unlock(&V_dyn_expire_lock)
VNET_DEFINE_STATIC(uint32_t, dyn_buckets_max);
VNET_DEFINE_STATIC(uint32_t, curr_dyn_buckets);
VNET_DEFINE_STATIC(struct callout, dyn_timeout);
#define V_dyn_buckets_max VNET(dyn_buckets_max)
#define V_curr_dyn_buckets VNET(curr_dyn_buckets)
#define V_dyn_timeout VNET(dyn_timeout)
/* Maximum length of states chain in a bucket */
VNET_DEFINE_STATIC(uint32_t, curr_max_length);
#define V_curr_max_length VNET(curr_max_length)
VNET_DEFINE_STATIC(uint32_t, dyn_keep_states);
#define V_dyn_keep_states VNET(dyn_keep_states)
VNET_DEFINE_STATIC(uma_zone_t, dyn_data_zone);
VNET_DEFINE_STATIC(uma_zone_t, dyn_parent_zone);
VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv4_zone);
#ifdef INET6
VNET_DEFINE_STATIC(uma_zone_t, dyn_ipv6_zone);
#define V_dyn_ipv6_zone VNET(dyn_ipv6_zone)
#endif /* INET6 */
#define V_dyn_data_zone VNET(dyn_data_zone)
#define V_dyn_parent_zone VNET(dyn_parent_zone)
#define V_dyn_ipv4_zone VNET(dyn_ipv4_zone)
/*
* Timeouts for various events in handing dynamic rules.
*/
VNET_DEFINE_STATIC(uint32_t, dyn_ack_lifetime);
VNET_DEFINE_STATIC(uint32_t, dyn_syn_lifetime);
VNET_DEFINE_STATIC(uint32_t, dyn_fin_lifetime);
VNET_DEFINE_STATIC(uint32_t, dyn_rst_lifetime);
VNET_DEFINE_STATIC(uint32_t, dyn_udp_lifetime);
VNET_DEFINE_STATIC(uint32_t, dyn_short_lifetime);
#define V_dyn_ack_lifetime VNET(dyn_ack_lifetime)
#define V_dyn_syn_lifetime VNET(dyn_syn_lifetime)
#define V_dyn_fin_lifetime VNET(dyn_fin_lifetime)
#define V_dyn_rst_lifetime VNET(dyn_rst_lifetime)
#define V_dyn_udp_lifetime VNET(dyn_udp_lifetime)
#define V_dyn_short_lifetime VNET(dyn_short_lifetime)
/*
* Keepalives are sent if dyn_keepalive is set. They are sent every
* dyn_keepalive_period seconds, in the last dyn_keepalive_interval
* seconds of lifetime of a rule.
* dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
* than dyn_keepalive_period.
*/
VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_interval);
VNET_DEFINE_STATIC(uint32_t, dyn_keepalive_period);
VNET_DEFINE_STATIC(uint32_t, dyn_keepalive);
VNET_DEFINE_STATIC(time_t, dyn_keepalive_last);
#define V_dyn_keepalive_interval VNET(dyn_keepalive_interval)
#define V_dyn_keepalive_period VNET(dyn_keepalive_period)
#define V_dyn_keepalive VNET(dyn_keepalive)
#define V_dyn_keepalive_last VNET(dyn_keepalive_last)
VNET_DEFINE_STATIC(uint32_t, dyn_max); /* max # of dynamic states */
VNET_DEFINE_STATIC(uint32_t, dyn_count); /* number of states */
VNET_DEFINE_STATIC(uint32_t, dyn_parent_max); /* max # of parent states */
VNET_DEFINE_STATIC(uint32_t, dyn_parent_count); /* number of parent states */
#define V_dyn_max VNET(dyn_max)
#define V_dyn_count VNET(dyn_count)
#define V_dyn_parent_max VNET(dyn_parent_max)
#define V_dyn_parent_count VNET(dyn_parent_count)
#define DYN_COUNT_DEC(name) do { \
MPASS((V_ ## name) > 0); \
ck_pr_dec_32(&(V_ ## name)); \
} while (0)
#define DYN_COUNT_INC(name) ck_pr_inc_32(&(V_ ## name))
#define DYN_COUNT(name) ck_pr_load_32(&(V_ ## name))
static time_t last_log; /* Log ratelimiting */
/*
* Get/set maximum number of dynamic states in given VNET instance.
*/
static int
sysctl_dyn_max(SYSCTL_HANDLER_ARGS)
{
uint32_t nstates;
int error;
nstates = V_dyn_max;
error = sysctl_handle_32(oidp, &nstates, 0, req);
/* Read operation or some error */
if ((error != 0) || (req->newptr == NULL))
return (error);
V_dyn_max = nstates;
uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
return (0);
}
static int
sysctl_dyn_parent_max(SYSCTL_HANDLER_ARGS)
{
uint32_t nstates;
int error;
nstates = V_dyn_parent_max;
error = sysctl_handle_32(oidp, &nstates, 0, req);
/* Read operation or some error */
if ((error != 0) || (req->newptr == NULL))
return (error);
V_dyn_parent_max = nstates;
uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
return (0);
}
static int
sysctl_dyn_buckets(SYSCTL_HANDLER_ARGS)
{
uint32_t nbuckets;
int error;
nbuckets = V_dyn_buckets_max;
error = sysctl_handle_32(oidp, &nbuckets, 0, req);
/* Read operation or some error */
if ((error != 0) || (req->newptr == NULL))
return (error);
if (nbuckets > 256)
V_dyn_buckets_max = 1 << fls(nbuckets - 1);
else
return (EINVAL);
return (0);
}
SYSCTL_DECL(_net_inet_ip_fw);
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_count,
CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_count), 0,
"Current number of dynamic states.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_parent_count,
CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(dyn_parent_count), 0,
"Current number of parent states. ");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets,
CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_dyn_buckets), 0,
"Current number of buckets for states hash table.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, curr_max_length,
CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(curr_max_length), 0,
"Current maximum length of states chains in hash buckets.");
SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_buckets,
CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_buckets,
"IU", "Max number of buckets for dynamic states hash table.");
SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_max,
CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_max,
"IU", "Max number of dynamic states.");
SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, dyn_parent_max,
CTLFLAG_VNET | CTLTYPE_U32 | CTLFLAG_RW, 0, 0, sysctl_dyn_parent_max,
"IU", "Max number of parent dynamic states.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_ack_lifetime), 0,
"Lifetime of dynamic states for TCP ACK.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_syn_lifetime), 0,
"Lifetime of dynamic states for TCP SYN.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_fin_lifetime), 0,
"Lifetime of dynamic states for TCP FIN.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_rst_lifetime), 0,
"Lifetime of dynamic states for TCP RST.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_udp_lifetime), 0,
"Lifetime of dynamic states for UDP.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_short_lifetime), 0,
"Lifetime of dynamic states for other situations.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keepalive,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keepalive), 0,
"Enable keepalives for dynamic states.");
SYSCTL_U32(_net_inet_ip_fw, OID_AUTO, dyn_keep_states,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(dyn_keep_states), 0,
"Do not flush dynamic states on rule deletion");
#ifdef IPFIREWALL_DYNDEBUG
#define DYN_DEBUG(fmt, ...) do { \
printf("%s: " fmt "\n", __func__, __VA_ARGS__); \
} while (0)
#else
#define DYN_DEBUG(fmt, ...)
#endif /* !IPFIREWALL_DYNDEBUG */
#ifdef INET6
/* Functions to work with IPv6 states */
static struct dyn_ipv6_state *dyn_lookup_ipv6_state(
const struct ipfw_flow_id *, uint32_t, const void *,
struct ipfw_dyn_info *, int);
static int dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *,
uint32_t, const void *, int, uint32_t, uint16_t);
static struct dyn_ipv6_state *dyn_alloc_ipv6_state(
const struct ipfw_flow_id *, uint32_t, uint16_t, uint8_t);
static int dyn_add_ipv6_state(void *, uint32_t, uint16_t,
const struct ipfw_flow_id *, uint32_t, const void *, int, uint32_t,
struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t);
static void dyn_export_ipv6_state(const struct dyn_ipv6_state *,
ipfw_dyn_rule *);
static uint32_t dyn_getscopeid(const struct ip_fw_args *);
static void dyn_make_keepalive_ipv6(struct mbuf *, const struct in6_addr *,
const struct in6_addr *, uint32_t, uint32_t, uint32_t, uint16_t,
uint16_t);
static void dyn_enqueue_keepalive_ipv6(struct mbufq *,
const struct dyn_ipv6_state *);
static void dyn_send_keepalive_ipv6(struct ip_fw_chain *);
static struct dyn_ipv6_state *dyn_lookup_ipv6_parent(
const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t,
uint32_t);
static struct dyn_ipv6_state *dyn_lookup_ipv6_parent_locked(
const struct ipfw_flow_id *, uint32_t, const void *, uint32_t, uint16_t,
uint32_t);
static struct dyn_ipv6_state *dyn_add_ipv6_parent(void *, uint32_t, uint16_t,
const struct ipfw_flow_id *, uint32_t, uint32_t, uint32_t, uint16_t);
#endif /* INET6 */
/* Functions to work with limit states */
static void *dyn_get_parent_state(const struct ipfw_flow_id *, uint32_t,
struct ip_fw *, uint32_t, uint32_t, uint16_t);
static struct dyn_ipv4_state *dyn_lookup_ipv4_parent(
const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t);
static struct dyn_ipv4_state *dyn_lookup_ipv4_parent_locked(
const struct ipfw_flow_id *, const void *, uint32_t, uint16_t, uint32_t);
static struct dyn_parent *dyn_alloc_parent(void *, uint32_t, uint16_t,
uint32_t);
static struct dyn_ipv4_state *dyn_add_ipv4_parent(void *, uint32_t, uint16_t,
const struct ipfw_flow_id *, uint32_t, uint32_t, uint16_t);
static void dyn_tick(void *);
static void dyn_expire_states(struct ip_fw_chain *, ipfw_range_tlv *);
static void dyn_free_states(struct ip_fw_chain *);
static void dyn_export_parent(const struct dyn_parent *, uint16_t, uint8_t,
ipfw_dyn_rule *);
static void dyn_export_data(const struct dyn_data *, uint16_t, uint8_t,
uint8_t, ipfw_dyn_rule *);
static uint32_t dyn_update_tcp_state(struct dyn_data *,
const struct ipfw_flow_id *, const struct tcphdr *, int);
static void dyn_update_proto_state(struct dyn_data *,
const struct ipfw_flow_id *, const void *, int, int);
/* Functions to work with IPv4 states */
struct dyn_ipv4_state *dyn_lookup_ipv4_state(const struct ipfw_flow_id *,
const void *, struct ipfw_dyn_info *, int);
static int dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *,
const void *, int, uint32_t, uint16_t);
static struct dyn_ipv4_state *dyn_alloc_ipv4_state(
const struct ipfw_flow_id *, uint16_t, uint8_t);
static int dyn_add_ipv4_state(void *, uint32_t, uint16_t,
const struct ipfw_flow_id *, const void *, int, uint32_t,
struct ipfw_dyn_info *, uint16_t, uint16_t, uint8_t);
static void dyn_export_ipv4_state(const struct dyn_ipv4_state *,
ipfw_dyn_rule *);
/*
* Named states support.
*/
static char *default_state_name = "default";
struct dyn_state_obj {
struct named_object no;
char name[64];
};
#define DYN_STATE_OBJ(ch, cmd) \
((struct dyn_state_obj *)SRV_OBJECT(ch, (cmd)->arg1))
/*
* Classifier callback.
* Return 0 if opcode contains object that should be referenced
* or rewritten.
*/
static int
dyn_classify(ipfw_insn *cmd, uint16_t *puidx, uint8_t *ptype)
{
DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
/* Don't rewrite "check-state any" */
if (cmd->arg1 == 0 &&
cmd->opcode == O_CHECK_STATE)
return (1);
*puidx = cmd->arg1;
*ptype = 0;
return (0);
}
static void
dyn_update(ipfw_insn *cmd, uint16_t idx)
{
cmd->arg1 = idx;
DYN_DEBUG("opcode %d, arg1 %d", cmd->opcode, cmd->arg1);
}
static int
dyn_findbyname(struct ip_fw_chain *ch, struct tid_info *ti,
struct named_object **pno)
{
ipfw_obj_ntlv *ntlv;
const char *name;
DYN_DEBUG("uidx %d", ti->uidx);
if (ti->uidx != 0) {
if (ti->tlvs == NULL)
return (EINVAL);
/* Search ntlv in the buffer provided by user */
ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
IPFW_TLV_STATE_NAME);
if (ntlv == NULL)
return (EINVAL);
name = ntlv->name;
} else
name = default_state_name;
/*
* Search named object with corresponding name.
* Since states objects are global - ignore the set value
* and use zero instead.
*/
*pno = ipfw_objhash_lookup_name_type(CHAIN_TO_SRV(ch), 0,
IPFW_TLV_STATE_NAME, name);
/*
* We always return success here.
* The caller will check *pno and mark object as unresolved,
* then it will automatically create "default" object.
*/
return (0);
}
static struct named_object *
dyn_findbykidx(struct ip_fw_chain *ch, uint16_t idx)
{
DYN_DEBUG("kidx %d", idx);
return (ipfw_objhash_lookup_kidx(CHAIN_TO_SRV(ch), idx));
}
static int
dyn_create(struct ip_fw_chain *ch, struct tid_info *ti,
uint16_t *pkidx)
{
struct namedobj_instance *ni;
struct dyn_state_obj *obj;
struct named_object *no;
ipfw_obj_ntlv *ntlv;
char *name;
DYN_DEBUG("uidx %d", ti->uidx);
if (ti->uidx != 0) {
if (ti->tlvs == NULL)
return (EINVAL);
ntlv = ipfw_find_name_tlv_type(ti->tlvs, ti->tlen, ti->uidx,
IPFW_TLV_STATE_NAME);
if (ntlv == NULL)
return (EINVAL);
name = ntlv->name;
} else
name = default_state_name;
ni = CHAIN_TO_SRV(ch);
obj = malloc(sizeof(*obj), M_IPFW, M_WAITOK | M_ZERO);
obj->no.name = obj->name;
obj->no.etlv = IPFW_TLV_STATE_NAME;
strlcpy(obj->name, name, sizeof(obj->name));
IPFW_UH_WLOCK(ch);
no = ipfw_objhash_lookup_name_type(ni, 0,
IPFW_TLV_STATE_NAME, name);
if (no != NULL) {
/*
* Object is already created.
* Just return its kidx and bump refcount.
*/
*pkidx = no->kidx;
no->refcnt++;
IPFW_UH_WUNLOCK(ch);
free(obj, M_IPFW);
DYN_DEBUG("\tfound kidx %d", *pkidx);
return (0);
}
if (ipfw_objhash_alloc_idx(ni, &obj->no.kidx) != 0) {
DYN_DEBUG("\talloc_idx failed for %s", name);
IPFW_UH_WUNLOCK(ch);
free(obj, M_IPFW);
return (ENOSPC);
}
ipfw_objhash_add(ni, &obj->no);
SRV_OBJECT(ch, obj->no.kidx) = obj;
obj->no.refcnt++;
*pkidx = obj->no.kidx;
IPFW_UH_WUNLOCK(ch);
DYN_DEBUG("\tcreated kidx %d", *pkidx);
return (0);
}
static void
dyn_destroy(struct ip_fw_chain *ch, struct named_object *no)
{
struct dyn_state_obj *obj;
IPFW_UH_WLOCK_ASSERT(ch);
KASSERT(no->etlv == IPFW_TLV_STATE_NAME,
("%s: wrong object type %u", __func__, no->etlv));
KASSERT(no->refcnt == 1,
("Destroying object '%s' (type %u, idx %u) with refcnt %u",
no->name, no->etlv, no->kidx, no->refcnt));
DYN_DEBUG("kidx %d", no->kidx);
obj = SRV_OBJECT(ch, no->kidx);
SRV_OBJECT(ch, no->kidx) = NULL;
ipfw_objhash_del(CHAIN_TO_SRV(ch), no);
ipfw_objhash_free_idx(CHAIN_TO_SRV(ch), no->kidx);
free(obj, M_IPFW);
}
static struct opcode_obj_rewrite dyn_opcodes[] = {
{
O_KEEP_STATE, IPFW_TLV_STATE_NAME,
dyn_classify, dyn_update,
dyn_findbyname, dyn_findbykidx,
dyn_create, dyn_destroy
},
{
O_CHECK_STATE, IPFW_TLV_STATE_NAME,
dyn_classify, dyn_update,
dyn_findbyname, dyn_findbykidx,
dyn_create, dyn_destroy
},
{
O_PROBE_STATE, IPFW_TLV_STATE_NAME,
dyn_classify, dyn_update,
dyn_findbyname, dyn_findbykidx,
dyn_create, dyn_destroy
},
{
O_LIMIT, IPFW_TLV_STATE_NAME,
dyn_classify, dyn_update,
dyn_findbyname, dyn_findbykidx,
dyn_create, dyn_destroy
},
};
/*
* IMPORTANT: the hash function for dynamic rules must be commutative
* in source and destination (ip,port), because rules are bidirectional
* and we want to find both in the same bucket.
*/
#ifndef IPFIREWALL_JENKINSHASH
static __inline uint32_t
hash_packet(const struct ipfw_flow_id *id)
{
uint32_t i;
#ifdef INET6
if (IS_IP6_FLOW_ID(id))
i = ntohl((id->dst_ip6.__u6_addr.__u6_addr32[2]) ^
(id->dst_ip6.__u6_addr.__u6_addr32[3]) ^
(id->src_ip6.__u6_addr.__u6_addr32[2]) ^
(id->src_ip6.__u6_addr.__u6_addr32[3]));
else
#endif /* INET6 */
i = (id->dst_ip) ^ (id->src_ip);
i ^= (id->dst_port) ^ (id->src_port);
return (i);
}
static __inline uint32_t
hash_parent(const struct ipfw_flow_id *id, const void *rule)
{
return (hash_packet(id) ^ ((uintptr_t)rule));
}
#else /* IPFIREWALL_JENKINSHASH */
VNET_DEFINE_STATIC(uint32_t, dyn_hashseed);
#define V_dyn_hashseed VNET(dyn_hashseed)
static __inline int
addrcmp4(const struct ipfw_flow_id *id)
{
if (id->src_ip < id->dst_ip)
return (0);
if (id->src_ip > id->dst_ip)
return (1);
if (id->src_port <= id->dst_port)
return (0);
return (1);
}
#ifdef INET6
static __inline int
addrcmp6(const struct ipfw_flow_id *id)
{
int ret;
ret = memcmp(&id->src_ip6, &id->dst_ip6, sizeof(struct in6_addr));
if (ret < 0)
return (0);
if (ret > 0)
return (1);
if (id->src_port <= id->dst_port)
return (0);
return (1);
}
static __inline uint32_t
hash_packet6(const struct ipfw_flow_id *id)
{
struct tuple6 {
struct in6_addr addr[2];
uint16_t port[2];
} t6;
if (addrcmp6(id) == 0) {
t6.addr[0] = id->src_ip6;
t6.addr[1] = id->dst_ip6;
t6.port[0] = id->src_port;
t6.port[1] = id->dst_port;
} else {
t6.addr[0] = id->dst_ip6;
t6.addr[1] = id->src_ip6;
t6.port[0] = id->dst_port;
t6.port[1] = id->src_port;
}
return (jenkins_hash32((const uint32_t *)&t6,
sizeof(t6) / sizeof(uint32_t), V_dyn_hashseed));
}
#endif
static __inline uint32_t
hash_packet(const struct ipfw_flow_id *id)
{
struct tuple4 {
in_addr_t addr[2];
uint16_t port[2];
} t4;
if (IS_IP4_FLOW_ID(id)) {
/* All fields are in host byte order */
if (addrcmp4(id) == 0) {
t4.addr[0] = id->src_ip;
t4.addr[1] = id->dst_ip;
t4.port[0] = id->src_port;
t4.port[1] = id->dst_port;
} else {
t4.addr[0] = id->dst_ip;
t4.addr[1] = id->src_ip;
t4.port[0] = id->dst_port;
t4.port[1] = id->src_port;
}
return (jenkins_hash32((const uint32_t *)&t4,
sizeof(t4) / sizeof(uint32_t), V_dyn_hashseed));
} else
#ifdef INET6
if (IS_IP6_FLOW_ID(id))
return (hash_packet6(id));
#endif
return (0);
}
static __inline uint32_t
hash_parent(const struct ipfw_flow_id *id, const void *rule)
{
return (jenkins_hash32((const uint32_t *)&rule,
sizeof(rule) / sizeof(uint32_t), hash_packet(id)));
}
#endif /* IPFIREWALL_JENKINSHASH */
/*
* Print customizable flow id description via log(9) facility.
*/
static void
print_dyn_rule_flags(const struct ipfw_flow_id *id, int dyn_type,
int log_flags, char *prefix, char *postfix)
{
struct in_addr da;
#ifdef INET6
char src[INET6_ADDRSTRLEN], dst[INET6_ADDRSTRLEN];
#else
char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN];
#endif
#ifdef INET6
if (IS_IP6_FLOW_ID(id)) {
ip6_sprintf(src, &id->src_ip6);
ip6_sprintf(dst, &id->dst_ip6);
} else
#endif
{
da.s_addr = htonl(id->src_ip);
inet_ntop(AF_INET, &da, src, sizeof(src));
da.s_addr = htonl(id->dst_ip);
inet_ntop(AF_INET, &da, dst, sizeof(dst));
}
log(log_flags, "ipfw: %s type %d %s %d -> %s %d, %d %s\n",
prefix, dyn_type, src, id->src_port, dst,
id->dst_port, V_dyn_count, postfix);
}
#define print_dyn_rule(id, dtype, prefix, postfix) \
print_dyn_rule_flags(id, dtype, LOG_DEBUG, prefix, postfix)
#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0)
#define TIME_LE(a,b) ((int)((a)-(b)) < 0)
#define _SEQ_GE(a,b) ((int)((a)-(b)) >= 0)
#define BOTH_SYN (TH_SYN | (TH_SYN << 8))
#define BOTH_FIN (TH_FIN | (TH_FIN << 8))
#define TCP_FLAGS (TH_FLAGS | (TH_FLAGS << 8))
#define ACK_FWD 0x00010000 /* fwd ack seen */
#define ACK_REV 0x00020000 /* rev ack seen */
#define ACK_BOTH (ACK_FWD | ACK_REV)
static uint32_t
dyn_update_tcp_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
const struct tcphdr *tcp, int dir)
{
uint32_t ack, expire;
uint32_t state, old;
uint8_t th_flags;
expire = data->expire;
old = state = data->state;
th_flags = pkt->_flags & (TH_FIN | TH_SYN | TH_RST);
state |= (dir == MATCH_FORWARD) ? th_flags: (th_flags << 8);
switch (state & TCP_FLAGS) {
case TH_SYN: /* opening */
expire = time_uptime + V_dyn_syn_lifetime;
break;
case BOTH_SYN: /* move to established */
case BOTH_SYN | TH_FIN: /* one side tries to close */
case BOTH_SYN | (TH_FIN << 8):
if (tcp == NULL)
break;
ack = ntohl(tcp->th_ack);
if (dir == MATCH_FORWARD) {
if (data->ack_fwd == 0 ||
_SEQ_GE(ack, data->ack_fwd)) {
state |= ACK_FWD;
if (data->ack_fwd != ack)
ck_pr_store_32(&data->ack_fwd, ack);
}
} else {
if (data->ack_rev == 0 ||
_SEQ_GE(ack, data->ack_rev)) {
state |= ACK_REV;
if (data->ack_rev != ack)
ck_pr_store_32(&data->ack_rev, ack);
}
}
if ((state & ACK_BOTH) == ACK_BOTH) {
/*
* Set expire time to V_dyn_ack_lifetime only if
* we got ACKs for both directions.
* We use XOR here to avoid possible state
* overwriting in concurrent thread.
*/
expire = time_uptime + V_dyn_ack_lifetime;
ck_pr_xor_32(&data->state, ACK_BOTH);
} else if ((data->state & ACK_BOTH) != (state & ACK_BOTH))
ck_pr_or_32(&data->state, state & ACK_BOTH);
break;
case BOTH_SYN | BOTH_FIN: /* both sides closed */
if (V_dyn_fin_lifetime >= V_dyn_keepalive_period)
V_dyn_fin_lifetime = V_dyn_keepalive_period - 1;
expire = time_uptime + V_dyn_fin_lifetime;
break;
default:
if (V_dyn_keepalive != 0 &&
V_dyn_rst_lifetime >= V_dyn_keepalive_period)
V_dyn_rst_lifetime = V_dyn_keepalive_period - 1;
expire = time_uptime + V_dyn_rst_lifetime;
}
/* Save TCP state if it was changed */
if ((state & TCP_FLAGS) != (old & TCP_FLAGS))
ck_pr_or_32(&data->state, state & TCP_FLAGS);
return (expire);
}
/*
* Update ULP specific state.
* For TCP we keep sequence numbers and flags. For other protocols
* currently we update only expire time. Packets and bytes counters
* are also updated here.
*/
static void
dyn_update_proto_state(struct dyn_data *data, const struct ipfw_flow_id *pkt,
const void *ulp, int pktlen, int dir)
{
uint32_t expire;
/* NOTE: we are in critical section here. */
switch (pkt->proto) {
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
expire = time_uptime + V_dyn_udp_lifetime;
break;
case IPPROTO_TCP:
expire = dyn_update_tcp_state(data, pkt, ulp, dir);
break;
default:
expire = time_uptime + V_dyn_short_lifetime;
}
/*
* Expiration timer has the per-second granularity, no need to update
* it every time when state is matched.
*/
if (data->expire != expire)
ck_pr_store_32(&data->expire, expire);
if (dir == MATCH_FORWARD)
DYN_COUNTER_INC(data, fwd, pktlen);
else
DYN_COUNTER_INC(data, rev, pktlen);
}
/*
* Lookup IPv4 state.
* Must be called in critical section.
*/
struct dyn_ipv4_state *
dyn_lookup_ipv4_state(const struct ipfw_flow_id *pkt, const void *ulp,
struct ipfw_dyn_info *info, int pktlen)
{
struct dyn_ipv4_state *s;
uint32_t version, bucket;
bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
info->version = DYN_BUCKET_VERSION(bucket, ipv4_add);
restart:
version = DYN_BUCKET_VERSION(bucket, ipv4_del);
CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
DYNSTATE_PROTECT(s);
if (version != DYN_BUCKET_VERSION(bucket, ipv4_del))
goto restart;
if (s->proto != pkt->proto)
continue;
if (info->kidx != 0 && s->kidx != info->kidx)
continue;
if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
info->direction = MATCH_FORWARD;
break;
}
if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
info->direction = MATCH_REVERSE;
break;
}
}
if (s != NULL)
dyn_update_proto_state(s->data, pkt, ulp, pktlen,
info->direction);
return (s);
}
/*
* Lookup IPv4 state.
* Simplifed version is used to check that matching state doesn't exist.
*/
static int
dyn_lookup_ipv4_state_locked(const struct ipfw_flow_id *pkt,
const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
{
struct dyn_ipv4_state *s;
int dir;
dir = MATCH_NONE;
DYN_BUCKET_ASSERT(bucket);
CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
if (s->proto != pkt->proto ||
s->kidx != kidx)
continue;
if (s->sport == pkt->src_port &&
s->dport == pkt->dst_port &&
s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
dir = MATCH_FORWARD;
break;
}
if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
s->src == pkt->dst_ip && s->dst == pkt->src_ip) {
dir = MATCH_REVERSE;
break;
}
}
if (s != NULL)
dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
return (s != NULL);
}
struct dyn_ipv4_state *
dyn_lookup_ipv4_parent(const struct ipfw_flow_id *pkt, const void *rule,
uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
{
struct dyn_ipv4_state *s;
uint32_t version, bucket;
bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
restart:
version = DYN_BUCKET_VERSION(bucket, ipv4_parent_del);
CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
DYNSTATE_PROTECT(s);
if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_del))
goto restart;
/*
* NOTE: we do not need to check kidx, because parent rule
* can not create states with different kidx.
* And parent rule always created for forward direction.
*/
if (s->limit->parent == rule &&
s->limit->ruleid == ruleid &&
s->limit->rulenum == rulenum &&
s->proto == pkt->proto &&
s->sport == pkt->src_port &&
s->dport == pkt->dst_port &&
s->src == pkt->src_ip && s->dst == pkt->dst_ip) {
if (s->limit->expire != time_uptime +
V_dyn_short_lifetime)
ck_pr_store_32(&s->limit->expire,
time_uptime + V_dyn_short_lifetime);
break;
}
}
return (s);
}
static struct dyn_ipv4_state *
dyn_lookup_ipv4_parent_locked(const struct ipfw_flow_id *pkt,
const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
{
struct dyn_ipv4_state *s;
DYN_BUCKET_ASSERT(bucket);
CK_SLIST_FOREACH(s, &V_dyn_ipv4_parent[bucket], entry) {
if (s->limit->parent == rule &&
s->limit->ruleid == ruleid &&
s->limit->rulenum == rulenum &&
s->proto == pkt->proto &&
s->sport == pkt->src_port &&
s->dport == pkt->dst_port &&
s->src == pkt->src_ip && s->dst == pkt->dst_ip)
break;
}
return (s);
}
#ifdef INET6
static uint32_t
dyn_getscopeid(const struct ip_fw_args *args)
{
/*
* If source or destination address is an scopeid address, we need
* determine the scope zone id to resolve address scope ambiguity.
*/
if (IN6_IS_ADDR_LINKLOCAL(&args->f_id.src_ip6) ||
IN6_IS_ADDR_LINKLOCAL(&args->f_id.dst_ip6))
return (in6_getscopezone(args->ifp, IPV6_ADDR_SCOPE_LINKLOCAL));
return (0);
}
/*
* Lookup IPv6 state.
* Must be called in critical section.
*/
static struct dyn_ipv6_state *
dyn_lookup_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
const void *ulp, struct ipfw_dyn_info *info, int pktlen)
{
struct dyn_ipv6_state *s;
uint32_t version, bucket;
bucket = DYN_BUCKET(info->hashval, V_curr_dyn_buckets);
info->version = DYN_BUCKET_VERSION(bucket, ipv6_add);
restart:
version = DYN_BUCKET_VERSION(bucket, ipv6_del);
CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
DYNSTATE_PROTECT(s);
if (version != DYN_BUCKET_VERSION(bucket, ipv6_del))
goto restart;
if (s->proto != pkt->proto || s->zoneid != zoneid)
continue;
if (info->kidx != 0 && s->kidx != info->kidx)
continue;
if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
info->direction = MATCH_FORWARD;
break;
}
if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
info->direction = MATCH_REVERSE;
break;
}
}
if (s != NULL)
dyn_update_proto_state(s->data, pkt, ulp, pktlen,
info->direction);
return (s);
}
/*
* Lookup IPv6 state.
* Simplifed version is used to check that matching state doesn't exist.
*/
static int
dyn_lookup_ipv6_state_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
const void *ulp, int pktlen, uint32_t bucket, uint16_t kidx)
{
struct dyn_ipv6_state *s;
int dir;
dir = MATCH_NONE;
DYN_BUCKET_ASSERT(bucket);
CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
if (s->proto != pkt->proto || s->kidx != kidx ||
s->zoneid != zoneid)
continue;
if (s->sport == pkt->src_port && s->dport == pkt->dst_port &&
IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
dir = MATCH_FORWARD;
break;
}
if (s->sport == pkt->dst_port && s->dport == pkt->src_port &&
IN6_ARE_ADDR_EQUAL(&s->src, &pkt->dst_ip6) &&
IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->src_ip6)) {
dir = MATCH_REVERSE;
break;
}
}
if (s != NULL)
dyn_update_proto_state(s->data, pkt, ulp, pktlen, dir);
return (s != NULL);
}
static struct dyn_ipv6_state *
dyn_lookup_ipv6_parent(const struct ipfw_flow_id *pkt, uint32_t zoneid,
const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t hashval)
{
struct dyn_ipv6_state *s;
uint32_t version, bucket;
bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
restart:
version = DYN_BUCKET_VERSION(bucket, ipv6_parent_del);
CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
DYNSTATE_PROTECT(s);
if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_del))
goto restart;
/*
* NOTE: we do not need to check kidx, because parent rule
* can not create states with different kidx.
* Also parent rule always created for forward direction.
*/
if (s->limit->parent == rule &&
s->limit->ruleid == ruleid &&
s->limit->rulenum == rulenum &&
s->proto == pkt->proto &&
s->sport == pkt->src_port &&
s->dport == pkt->dst_port && s->zoneid == zoneid &&
IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6)) {
if (s->limit->expire != time_uptime +
V_dyn_short_lifetime)
ck_pr_store_32(&s->limit->expire,
time_uptime + V_dyn_short_lifetime);
break;
}
}
return (s);
}
static struct dyn_ipv6_state *
dyn_lookup_ipv6_parent_locked(const struct ipfw_flow_id *pkt, uint32_t zoneid,
const void *rule, uint32_t ruleid, uint16_t rulenum, uint32_t bucket)
{
struct dyn_ipv6_state *s;
DYN_BUCKET_ASSERT(bucket);
CK_SLIST_FOREACH(s, &V_dyn_ipv6_parent[bucket], entry) {
if (s->limit->parent == rule &&
s->limit->ruleid == ruleid &&
s->limit->rulenum == rulenum &&
s->proto == pkt->proto &&
s->sport == pkt->src_port &&
s->dport == pkt->dst_port && s->zoneid == zoneid &&
IN6_ARE_ADDR_EQUAL(&s->src, &pkt->src_ip6) &&
IN6_ARE_ADDR_EQUAL(&s->dst, &pkt->dst_ip6))
break;
}
return (s);
}
#endif /* INET6 */
/*
* Lookup dynamic state.
* pkt - filled by ipfw_chk() ipfw_flow_id;
* ulp - determined by ipfw_chk() upper level protocol header;
* dyn_info - info about matched state to return back;
* Returns pointer to state's parent rule and dyn_info. If there is
* no state, NULL is returned.
* On match ipfw_dyn_lookup() updates state's counters.
*/
struct ip_fw *
ipfw_dyn_lookup_state(const struct ip_fw_args *args, const void *ulp,
int pktlen, const ipfw_insn *cmd, struct ipfw_dyn_info *info)
{
struct dyn_data *data;
struct ip_fw *rule;
IPFW_RLOCK_ASSERT(&V_layer3_chain);
data = NULL;
rule = NULL;
info->kidx = cmd->arg1;
info->direction = MATCH_NONE;
info->hashval = hash_packet(&args->f_id);
DYNSTATE_CRITICAL_ENTER();
if (IS_IP4_FLOW_ID(&args->f_id)) {
struct dyn_ipv4_state *s;
s = dyn_lookup_ipv4_state(&args->f_id, ulp, info, pktlen);
if (s != NULL) {
/*
* Dynamic states are created using the same 5-tuple,
* so it is assumed, that parent rule for O_LIMIT
* state has the same address family.
*/
data = s->data;
if (s->type == O_LIMIT) {
s = data->parent;
rule = s->limit->parent;
} else
rule = data->parent;
}
}
#ifdef INET6
else if (IS_IP6_FLOW_ID(&args->f_id)) {
struct dyn_ipv6_state *s;
s = dyn_lookup_ipv6_state(&args->f_id, dyn_getscopeid(args),
ulp, info, pktlen);
if (s != NULL) {
data = s->data;
if (s->type == O_LIMIT) {
s = data->parent;
rule = s->limit->parent;
} else
rule = data->parent;
}
}
#endif
if (data != NULL) {
/*
* If cached chain id is the same, we can avoid rule index
* lookup. Otherwise do lookup and update chain_id and f_pos.
* It is safe even if there is concurrent thread that want
* update the same state, because chain->id can be changed
* only under IPFW_WLOCK().
*/
if (data->chain_id != V_layer3_chain.id) {
data->f_pos = ipfw_find_rule(&V_layer3_chain,
data->rulenum, data->ruleid);
/*
* Check that found state has not orphaned.
* When chain->id being changed the parent
* rule can be deleted. If found rule doesn't
* match the parent pointer, consider this
* result as MATCH_NONE and return NULL.
*
* This will lead to creation of new similar state
* that will be added into head of this bucket.
* And the state that we currently have matched
* should be deleted by dyn_expire_states().
*
* In case when dyn_keep_states is enabled, return
* pointer to deleted rule and f_pos value
* corresponding to penultimate rule.
* When we have enabled V_dyn_keep_states, states
* that become orphaned will get the DYN_REFERENCED
* flag and rule will keep around. So we can return
* it. But since it is not in the rules map, we need
* return such f_pos value, so after the state
* handling if the search will continue, the next rule
* will be the last one - the default rule.
*/
if (V_layer3_chain.map[data->f_pos] == rule) {
data->chain_id = V_layer3_chain.id;
info->f_pos = data->f_pos;
} else if (V_dyn_keep_states != 0) {
/*
* The original rule pointer is still usable.
* So, we return it, but f_pos need to be
* changed to point to the penultimate rule.
*/
MPASS(V_layer3_chain.n_rules > 1);
data->chain_id = V_layer3_chain.id;
data->f_pos = V_layer3_chain.n_rules - 2;
info->f_pos = data->f_pos;
} else {
rule = NULL;
info->direction = MATCH_NONE;
DYN_DEBUG("rule %p [%u, %u] is considered "
"invalid in data %p", rule, data->ruleid,
data->rulenum, data);
/* info->f_pos doesn't matter here. */
}
} else
info->f_pos = data->f_pos;
}
DYNSTATE_CRITICAL_EXIT();
#if 0
/*
* Return MATCH_NONE if parent rule is in disabled set.
* This will lead to creation of new similar state that
* will be added into head of this bucket.
*
* XXXAE: we need to be able update state's set when parent
* rule set is changed.
*/
if (rule != NULL && (V_set_disable & (1 << rule->set))) {
rule = NULL;
info->direction = MATCH_NONE;
}
#endif
return (rule);
}
static struct dyn_parent *
dyn_alloc_parent(void *parent, uint32_t ruleid, uint16_t rulenum,
uint32_t hashval)
{
struct dyn_parent *limit;
limit = uma_zalloc(V_dyn_parent_zone, M_NOWAIT | M_ZERO);
if (limit == NULL) {
if (last_log != time_uptime) {
last_log = time_uptime;
log(LOG_DEBUG,
"ipfw: Cannot allocate parent dynamic state, "
"consider increasing "
"net.inet.ip.fw.dyn_parent_max\n");
}
return (NULL);
}
limit->parent = parent;
limit->ruleid = ruleid;
limit->rulenum = rulenum;
limit->hashval = hashval;
limit->expire = time_uptime + V_dyn_short_lifetime;
return (limit);
}
static struct dyn_data *
dyn_alloc_dyndata(void *parent, uint32_t ruleid, uint16_t rulenum,
const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
uint32_t hashval, uint16_t fibnum)
{
struct dyn_data *data;
data = uma_zalloc(V_dyn_data_zone, M_NOWAIT | M_ZERO);
if (data == NULL) {
if (last_log != time_uptime) {
last_log = time_uptime;
log(LOG_DEBUG,
"ipfw: Cannot allocate dynamic state, "
"consider increasing net.inet.ip.fw.dyn_max\n");
}
return (NULL);
}
data->parent = parent;
data->ruleid = ruleid;
data->rulenum = rulenum;
data->fibnum = fibnum;
data->hashval = hashval;
data->expire = time_uptime + V_dyn_syn_lifetime;
dyn_update_proto_state(data, pkt, ulp, pktlen, MATCH_FORWARD);
return (data);
}
static struct dyn_ipv4_state *
dyn_alloc_ipv4_state(const struct ipfw_flow_id *pkt, uint16_t kidx,
uint8_t type)
{
struct dyn_ipv4_state *s;
s = uma_zalloc(V_dyn_ipv4_zone, M_NOWAIT | M_ZERO);
if (s == NULL)
return (NULL);
s->type = type;
s->kidx = kidx;
s->proto = pkt->proto;
s->sport = pkt->src_port;
s->dport = pkt->dst_port;
s->src = pkt->src_ip;
s->dst = pkt->dst_ip;
return (s);
}
/*
* Add IPv4 parent state.
* Returns pointer to parent state. When it is not NULL we are in
* critical section and pointer protected by hazard pointer.
* When some error occurs, it returns NULL and exit from critical section
* is not needed.
*/
static struct dyn_ipv4_state *
dyn_add_ipv4_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
const struct ipfw_flow_id *pkt, uint32_t hashval, uint32_t version,
uint16_t kidx)
{
struct dyn_ipv4_state *s;
struct dyn_parent *limit;
uint32_t bucket;
bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
DYN_BUCKET_LOCK(bucket);
if (version != DYN_BUCKET_VERSION(bucket, ipv4_parent_add)) {
/*
* Bucket version has been changed since last lookup,
* do lookup again to be sure that state does not exist.
*/
s = dyn_lookup_ipv4_parent_locked(pkt, rule, ruleid,
rulenum, bucket);
if (s != NULL) {
/*
* Simultaneous thread has already created this
* state. Just return it.
*/
DYNSTATE_CRITICAL_ENTER();
DYNSTATE_PROTECT(s);
DYN_BUCKET_UNLOCK(bucket);
return (s);
}
}
limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval);
if (limit == NULL) {
DYN_BUCKET_UNLOCK(bucket);
return (NULL);
}
s = dyn_alloc_ipv4_state(pkt, kidx, O_LIMIT_PARENT);
if (s == NULL) {
DYN_BUCKET_UNLOCK(bucket);
uma_zfree(V_dyn_parent_zone, limit);
return (NULL);
}
s->limit = limit;
CK_SLIST_INSERT_HEAD(&V_dyn_ipv4_parent[bucket], s, entry);
DYN_COUNT_INC(dyn_parent_count);
DYN_BUCKET_VERSION_BUMP(bucket, ipv4_parent_add);
DYNSTATE_CRITICAL_ENTER();
DYNSTATE_PROTECT(s);
DYN_BUCKET_UNLOCK(bucket);
return (s);
}
static int
dyn_add_ipv4_state(void *parent, uint32_t ruleid, uint16_t rulenum,
const struct ipfw_flow_id *pkt, const void *ulp, int pktlen,
uint32_t hashval, struct ipfw_dyn_info *info, uint16_t fibnum,
uint16_t kidx, uint8_t type)
{
struct dyn_ipv4_state *s;
void *data;
uint32_t bucket;
bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
DYN_BUCKET_LOCK(bucket);
if (info->direction == MATCH_UNKNOWN ||
info->kidx != kidx ||
info->hashval != hashval ||
info->version != DYN_BUCKET_VERSION(bucket, ipv4_add)) {
/*
* Bucket version has been changed since last lookup,
* do lookup again to be sure that state does not exist.
*/
if (dyn_lookup_ipv4_state_locked(pkt, ulp, pktlen,
bucket, kidx) != 0) {
DYN_BUCKET_UNLOCK(bucket);
return (EEXIST);
}
}
data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp,
pktlen, hashval, fibnum);
if (data == NULL) {
DYN_BUCKET_UNLOCK(bucket);
return (ENOMEM);
}
s = dyn_alloc_ipv4_state(pkt, kidx, type);
if (s == NULL) {
DYN_BUCKET_UNLOCK(bucket);
uma_zfree(V_dyn_data_zone, data);
return (ENOMEM);
}
s->data = data;
CK_SLIST_INSERT_HEAD(&V_dyn_ipv4[bucket], s, entry);
DYN_COUNT_INC(dyn_count);
DYN_BUCKET_VERSION_BUMP(bucket, ipv4_add);
DYN_BUCKET_UNLOCK(bucket);
return (0);
}
#ifdef INET6
static struct dyn_ipv6_state *
dyn_alloc_ipv6_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
uint16_t kidx, uint8_t type)
{
struct dyn_ipv6_state *s;
s = uma_zalloc(V_dyn_ipv6_zone, M_NOWAIT | M_ZERO);
if (s == NULL)
return (NULL);
s->type = type;
s->kidx = kidx;
s->zoneid = zoneid;
s->proto = pkt->proto;
s->sport = pkt->src_port;
s->dport = pkt->dst_port;
s->src = pkt->src_ip6;
s->dst = pkt->dst_ip6;
return (s);
}
/*
* Add IPv6 parent state.
* Returns pointer to parent state. When it is not NULL we are in
* critical section and pointer protected by hazard pointer.
* When some error occurs, it return NULL and exit from critical section
* is not needed.
*/
static struct dyn_ipv6_state *
dyn_add_ipv6_parent(void *rule, uint32_t ruleid, uint16_t rulenum,
const struct ipfw_flow_id *pkt, uint32_t zoneid, uint32_t hashval,
uint32_t version, uint16_t kidx)
{
struct dyn_ipv6_state *s;
struct dyn_parent *limit;
uint32_t bucket;
bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
DYN_BUCKET_LOCK(bucket);
if (version != DYN_BUCKET_VERSION(bucket, ipv6_parent_add)) {
/*
* Bucket version has been changed since last lookup,
* do lookup again to be sure that state does not exist.
*/
s = dyn_lookup_ipv6_parent_locked(pkt, zoneid, rule, ruleid,
rulenum, bucket);
if (s != NULL) {
/*
* Simultaneous thread has already created this
* state. Just return it.
*/
DYNSTATE_CRITICAL_ENTER();
DYNSTATE_PROTECT(s);
DYN_BUCKET_UNLOCK(bucket);
return (s);
}
}
limit = dyn_alloc_parent(rule, ruleid, rulenum, hashval);
if (limit == NULL) {
DYN_BUCKET_UNLOCK(bucket);
return (NULL);
}
s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, O_LIMIT_PARENT);
if (s == NULL) {
DYN_BUCKET_UNLOCK(bucket);
uma_zfree(V_dyn_parent_zone, limit);
return (NULL);
}
s->limit = limit;
CK_SLIST_INSERT_HEAD(&V_dyn_ipv6_parent[bucket], s, entry);
DYN_COUNT_INC(dyn_parent_count);
DYN_BUCKET_VERSION_BUMP(bucket, ipv6_parent_add);
DYNSTATE_CRITICAL_ENTER();
DYNSTATE_PROTECT(s);
DYN_BUCKET_UNLOCK(bucket);
return (s);
}
static int
dyn_add_ipv6_state(void *parent, uint32_t ruleid, uint16_t rulenum,
const struct ipfw_flow_id *pkt, uint32_t zoneid, const void *ulp,
int pktlen, uint32_t hashval, struct ipfw_dyn_info *info,
uint16_t fibnum, uint16_t kidx, uint8_t type)
{
struct dyn_ipv6_state *s;
struct dyn_data *data;
uint32_t bucket;
bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
DYN_BUCKET_LOCK(bucket);
if (info->direction == MATCH_UNKNOWN ||
info->kidx != kidx ||
info->hashval != hashval ||
info->version != DYN_BUCKET_VERSION(bucket, ipv6_add)) {
/*
* Bucket version has been changed since last lookup,
* do lookup again to be sure that state does not exist.
*/
if (dyn_lookup_ipv6_state_locked(pkt, zoneid, ulp, pktlen,
bucket, kidx) != 0) {
DYN_BUCKET_UNLOCK(bucket);
return (EEXIST);
}
}
data = dyn_alloc_dyndata(parent, ruleid, rulenum, pkt, ulp,
pktlen, hashval, fibnum);
if (data == NULL) {
DYN_BUCKET_UNLOCK(bucket);
return (ENOMEM);
}
s = dyn_alloc_ipv6_state(pkt, zoneid, kidx, type);
if (s == NULL) {
DYN_BUCKET_UNLOCK(bucket);
uma_zfree(V_dyn_data_zone, data);
return (ENOMEM);
}
s->data = data;
CK_SLIST_INSERT_HEAD(&V_dyn_ipv6[bucket], s, entry);
DYN_COUNT_INC(dyn_count);
DYN_BUCKET_VERSION_BUMP(bucket, ipv6_add);
DYN_BUCKET_UNLOCK(bucket);
return (0);
}
#endif /* INET6 */
static void *
dyn_get_parent_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
struct ip_fw *rule, uint32_t hashval, uint32_t limit, uint16_t kidx)
{
char sbuf[24];
struct dyn_parent *p;
void *ret;
uint32_t bucket, version;
p = NULL;
ret = NULL;
bucket = DYN_BUCKET(hashval, V_curr_dyn_buckets);
DYNSTATE_CRITICAL_ENTER();
if (IS_IP4_FLOW_ID(pkt)) {
struct dyn_ipv4_state *s;
version = DYN_BUCKET_VERSION(bucket, ipv4_parent_add);
s = dyn_lookup_ipv4_parent(pkt, rule, rule->id,
rule->rulenum, bucket);
if (s == NULL) {
/*
* Exit from critical section because dyn_add_parent()
* will acquire bucket lock.
*/
DYNSTATE_CRITICAL_EXIT();
s = dyn_add_ipv4_parent(rule, rule->id,
rule->rulenum, pkt, hashval, version, kidx);
if (s == NULL)
return (NULL);
/* Now we are in critical section again. */
}
ret = s;
p = s->limit;
}
#ifdef INET6
else if (IS_IP6_FLOW_ID(pkt)) {
struct dyn_ipv6_state *s;
version = DYN_BUCKET_VERSION(bucket, ipv6_parent_add);
s = dyn_lookup_ipv6_parent(pkt, zoneid, rule, rule->id,
rule->rulenum, bucket);
if (s == NULL) {
/*
* Exit from critical section because dyn_add_parent()
* can acquire bucket mutex.
*/
DYNSTATE_CRITICAL_EXIT();
s = dyn_add_ipv6_parent(rule, rule->id,
rule->rulenum, pkt, zoneid, hashval, version,
kidx);
if (s == NULL)
return (NULL);
/* Now we are in critical section again. */
}
ret = s;
p = s->limit;
}
#endif
else {
DYNSTATE_CRITICAL_EXIT();
return (NULL);
}
/* Check the limit */
if (DPARENT_COUNT(p) >= limit) {
DYNSTATE_CRITICAL_EXIT();
if (V_fw_verbose && last_log != time_uptime) {
last_log = time_uptime;
snprintf(sbuf, sizeof(sbuf), "%u drop session",
rule->rulenum);
print_dyn_rule_flags(pkt, O_LIMIT,
LOG_SECURITY | LOG_DEBUG, sbuf,
"too many entries");
}
return (NULL);
}
/* Take new session into account. */
DPARENT_COUNT_INC(p);
/*
* We must exit from critical section because the following code
* can acquire bucket mutex.
* We rely on the the 'count' field. The state will not expire
* until it has some child states, i.e. 'count' field is not zero.
* Return state pointer, it will be used by child states as parent.
*/
DYNSTATE_CRITICAL_EXIT();
return (ret);
}
static int
dyn_install_state(const struct ipfw_flow_id *pkt, uint32_t zoneid,
uint16_t fibnum, const void *ulp, int pktlen, struct ip_fw *rule,
struct ipfw_dyn_info *info, uint32_t limit, uint16_t limit_mask,
uint16_t kidx, uint8_t type)
{
struct ipfw_flow_id id;
uint32_t hashval, parent_hashval, ruleid, rulenum;
int ret;
MPASS(type == O_LIMIT || type == O_KEEP_STATE);
ruleid = rule->id;
rulenum = rule->rulenum;
if (type == O_LIMIT) {
/* Create masked flow id and calculate bucket */
id.addr_type = pkt->addr_type;
id.proto = pkt->proto;
id.fib = fibnum; /* unused */
id.src_port = (limit_mask & DYN_SRC_PORT) ?
pkt->src_port: 0;
id.dst_port = (limit_mask & DYN_DST_PORT) ?
pkt->dst_port: 0;
if (IS_IP4_FLOW_ID(pkt)) {
id.src_ip = (limit_mask & DYN_SRC_ADDR) ?
pkt->src_ip: 0;
id.dst_ip = (limit_mask & DYN_DST_ADDR) ?
pkt->dst_ip: 0;
}
#ifdef INET6
else if (IS_IP6_FLOW_ID(pkt)) {
if (limit_mask & DYN_SRC_ADDR)
id.src_ip6 = pkt->src_ip6;
else
memset(&id.src_ip6, 0, sizeof(id.src_ip6));
if (limit_mask & DYN_DST_ADDR)
id.dst_ip6 = pkt->dst_ip6;
else
memset(&id.dst_ip6, 0, sizeof(id.dst_ip6));
}
#endif
else
return (EAFNOSUPPORT);
parent_hashval = hash_parent(&id, rule);
rule = dyn_get_parent_state(&id, zoneid, rule, parent_hashval,
limit, kidx);
if (rule == NULL) {
#if 0
if (V_fw_verbose && last_log != time_uptime) {
last_log = time_uptime;
snprintf(sbuf, sizeof(sbuf),
"%u drop session", rule->rulenum);
print_dyn_rule_flags(pkt, O_LIMIT,
LOG_SECURITY | LOG_DEBUG, sbuf,
"too many entries");
}
#endif
return (EACCES);
}
/*
* Limit is not reached, create new state.
* Now rule points to parent state.
*/
}
hashval = hash_packet(pkt);
if (IS_IP4_FLOW_ID(pkt))
ret = dyn_add_ipv4_state(rule, ruleid, rulenum, pkt,
ulp, pktlen, hashval, info, fibnum, kidx, type);
#ifdef INET6
else if (IS_IP6_FLOW_ID(pkt))
ret = dyn_add_ipv6_state(rule, ruleid, rulenum, pkt,
zoneid, ulp, pktlen, hashval, info, fibnum, kidx, type);
#endif /* INET6 */
else
ret = EAFNOSUPPORT;
if (type == O_LIMIT) {
if (ret != 0) {
/*
* We failed to create child state for O_LIMIT
* opcode. Since we already counted it in the parent,
* we must revert counter back. The 'rule' points to
* parent state, use it to get dyn_parent.
*
* XXXAE: it should be safe to use 'rule' pointer
* without extra lookup, parent state is referenced
* and should not be freed.
*/
if (IS_IP4_FLOW_ID(&id))
DPARENT_COUNT_DEC(
((struct dyn_ipv4_state *)rule)->limit);
#ifdef INET6
else if (IS_IP6_FLOW_ID(&id))
DPARENT_COUNT_DEC(
((struct dyn_ipv6_state *)rule)->limit);
#endif
}
}
/*
* EEXIST means that simultaneous thread has created this
* state. Consider this as success.
*
* XXXAE: should we invalidate 'info' content here?
*/
if (ret == EEXIST)
return (0);
return (ret);
}
/*
* Install dynamic state.
* chain - ipfw's instance;
* rule - the parent rule that installs the state;
* cmd - opcode that installs the state;
* args - ipfw arguments;
* ulp - upper level protocol header;
* pktlen - packet length;
* info - dynamic state lookup info;
* tablearg - tablearg id.
*
* Returns non-zero value (failure) if state is not installed because
* of errors or because session limitations are enforced.
*/
int
ipfw_dyn_install_state(struct ip_fw_chain *chain, struct ip_fw *rule,
const ipfw_insn_limit *cmd, const struct ip_fw_args *args,
const void *ulp, int pktlen, struct ipfw_dyn_info *info,
uint32_t tablearg)
{
uint32_t limit;
uint16_t limit_mask;
if (cmd->o.opcode == O_LIMIT) {
limit = IP_FW_ARG_TABLEARG(chain, cmd->conn_limit, limit);
limit_mask = cmd->limit_mask;
} else {
limit = 0;
limit_mask = 0;
}
return (dyn_install_state(&args->f_id,
#ifdef INET6
IS_IP6_FLOW_ID(&args->f_id) ? dyn_getscopeid(args):
#endif
0, M_GETFIB(args->m), ulp, pktlen, rule, info, limit,
limit_mask, cmd->o.arg1, cmd->o.opcode));
}
/*
* Free safe to remove state entries from expired lists.
*/
static void
dyn_free_states(struct ip_fw_chain *chain)
{
struct dyn_ipv4_state *s4, *s4n;
#ifdef INET6
struct dyn_ipv6_state *s6, *s6n;
#endif
int cached_count, i;
/*
* We keep pointers to objects that are in use on each CPU
* in the per-cpu dyn_hp pointer. When object is going to be
* removed, first of it is unlinked from the corresponding
* list. This leads to changing of dyn_bucket_xxx_delver version.
* Unlinked objects is placed into corresponding dyn_expired_xxx
* list. Reader that is going to dereference object pointer checks
* dyn_bucket_xxx_delver version before and after storing pointer
* into dyn_hp. If version is the same, the object is protected
* from freeing and it is safe to dereference. Othervise reader
* tries to iterate list again from the beginning, but this object
* now unlinked and thus will not be accessible.
*
* Copy dyn_hp pointers for each CPU into dyn_hp_cache array.
* It does not matter that some pointer can be changed in
* time while we are copying. We need to check, that objects
* removed in the previous pass are not in use. And if dyn_hp
* pointer does not contain it in the time when we are copying,
* it will not appear there, because it is already unlinked.
* And for new pointers we will not free objects that will be
* unlinked in this pass.
*/
cached_count = 0;
CPU_FOREACH(i) {
dyn_hp_cache[cached_count] = DYNSTATE_GET(i);
if (dyn_hp_cache[cached_count] != NULL)
cached_count++;
}
/*
* Free expired states that are safe to free.
* Check each entry from previous pass in the dyn_expired_xxx
* list, if pointer to the object is in the dyn_hp_cache array,
* keep it until next pass. Otherwise it is safe to free the
* object.
*
* XXXAE: optimize this to use SLIST_REMOVE_AFTER.
*/
#define DYN_FREE_STATES(s, next, name) do { \
s = SLIST_FIRST(&V_dyn_expired_ ## name); \
while (s != NULL) { \
next = SLIST_NEXT(s, expired); \
for (i = 0; i < cached_count; i++) \
if (dyn_hp_cache[i] == s) \
break; \
if (i == cached_count) { \
if (s->type == O_LIMIT_PARENT && \
s->limit->count != 0) { \
s = next; \
continue; \
} \
SLIST_REMOVE(&V_dyn_expired_ ## name, \
s, dyn_ ## name ## _state, expired); \
if (s->type == O_LIMIT_PARENT) \
uma_zfree(V_dyn_parent_zone, s->limit); \
else \
uma_zfree(V_dyn_data_zone, s->data); \
uma_zfree(V_dyn_ ## name ## _zone, s); \
} \
s = next; \
} \
} while (0)
/*
* Protect access to expired lists with DYN_EXPIRED_LOCK.
* Userland can invoke ipfw_expire_dyn_states() to delete
* specific states, this will lead to modification of expired
* lists.
*
* XXXAE: do we need DYN_EXPIRED_LOCK? We can just use
* IPFW_UH_WLOCK to protect access to these lists.
*/
DYN_EXPIRED_LOCK();
DYN_FREE_STATES(s4, s4n, ipv4);
#ifdef INET6
DYN_FREE_STATES(s6, s6n, ipv6);
#endif
DYN_EXPIRED_UNLOCK();
#undef DYN_FREE_STATES
}
/*
* Returns:
* 0 when state is not matched by specified range;
* 1 when state is matched by specified range;
* 2 when state is matched by specified range and requested deletion of
* dynamic states.
*/
static int
dyn_match_range(uint16_t rulenum, uint8_t set, const ipfw_range_tlv *rt)
{
MPASS(rt != NULL);
/* flush all states */
if (rt->flags & IPFW_RCFLAG_ALL) {
if (rt->flags & IPFW_RCFLAG_DYNAMIC)
return (2); /* forced */
return (1);
}
if ((rt->flags & IPFW_RCFLAG_SET) != 0 && set != rt->set)
return (0);
if ((rt->flags & IPFW_RCFLAG_RANGE) != 0 &&
(rulenum < rt->start_rule || rulenum > rt->end_rule))
return (0);
if (rt->flags & IPFW_RCFLAG_DYNAMIC)
return (2);
return (1);
}
static void
dyn_acquire_rule(struct ip_fw_chain *ch, struct dyn_data *data,
struct ip_fw *rule, uint16_t kidx)
{
struct dyn_state_obj *obj;
/*
* Do not acquire reference twice.
* This can happen when rule deletion executed for
* the same range, but different ruleset id.
*/
if (data->flags & DYN_REFERENCED)
return;
IPFW_UH_WLOCK_ASSERT(ch);
MPASS(kidx != 0);
data->flags |= DYN_REFERENCED;
/* Reference the named object */
obj = SRV_OBJECT(ch, kidx);
obj->no.refcnt++;
MPASS(obj->no.etlv == IPFW_TLV_STATE_NAME);
/* Reference the parent rule */
rule->refcnt++;
}
static void
dyn_release_rule(struct ip_fw_chain *ch, struct dyn_data *data,
struct ip_fw *rule, uint16_t kidx)
{
struct dyn_state_obj *obj;
IPFW_UH_WLOCK_ASSERT(ch);
MPASS(kidx != 0);
obj = SRV_OBJECT(ch, kidx);
if (obj->no.refcnt == 1)
dyn_destroy(ch, &obj->no);
else
obj->no.refcnt--;
if (--rule->refcnt == 1)
ipfw_free_rule(rule);
}
/*
* We do not keep O_LIMIT_PARENT states when V_dyn_keep_states is enabled.
* O_LIMIT state is created when new connection is going to be established
* and there is no matching state. So, since the old parent rule was deleted
* we can't create new states with old parent, and thus we can not account
* new connections with already established connections, and can not do
* proper limiting.
*/
static int
dyn_match_ipv4_state(struct ip_fw_chain *ch, struct dyn_ipv4_state *s,
const ipfw_range_tlv *rt)
{
struct ip_fw *rule;
int ret;
if (s->type == O_LIMIT_PARENT) {
rule = s->limit->parent;
return (dyn_match_range(s->limit->rulenum, rule->set, rt));
}
rule = s->data->parent;
if (s->type == O_LIMIT)
rule = ((struct dyn_ipv4_state *)rule)->limit->parent;
ret = dyn_match_range(s->data->rulenum, rule->set, rt);
if (ret == 0 || V_dyn_keep_states == 0 || ret > 1)
return (ret);
dyn_acquire_rule(ch, s->data, rule, s->kidx);
return (0);
}
#ifdef INET6
static int
dyn_match_ipv6_state(struct ip_fw_chain *ch, struct dyn_ipv6_state *s,
const ipfw_range_tlv *rt)
{
struct ip_fw *rule;
int ret;
if (s->type == O_LIMIT_PARENT) {
rule = s->limit->parent;
return (dyn_match_range(s->limit->rulenum, rule->set, rt));
}
rule = s->data->parent;
if (s->type == O_LIMIT)
rule = ((struct dyn_ipv6_state *)rule)->limit->parent;
ret = dyn_match_range(s->data->rulenum, rule->set, rt);
if (ret == 0 || V_dyn_keep_states == 0 || ret > 1)
return (ret);
dyn_acquire_rule(ch, s->data, rule, s->kidx);
return (0);
}
#endif
/*
* Unlink expired entries from states lists.
* @rt can be used to specify the range of states for deletion.
*/
static void
dyn_expire_states(struct ip_fw_chain *ch, ipfw_range_tlv *rt)
{
struct dyn_ipv4_slist expired_ipv4;
#ifdef INET6
struct dyn_ipv6_slist expired_ipv6;
struct dyn_ipv6_state *s6, *s6n, *s6p;
#endif
struct dyn_ipv4_state *s4, *s4n, *s4p;
void *rule;
int bucket, removed, length, max_length;
IPFW_UH_WLOCK_ASSERT(ch);
/*
* Unlink expired states from each bucket.
* With acquired bucket lock iterate entries of each lists:
* ipv4, ipv4_parent, ipv6, and ipv6_parent. Check expired time
* and unlink entry from the list, link entry into temporary
* expired_xxx lists then bump "del" bucket version.
*
* When an entry is removed, corresponding states counter is
* decremented. If entry has O_LIMIT type, parent's reference
* counter is decremented.
*
* NOTE: this function can be called from userspace context
* when user deletes rules. In this case all matched states
* will be forcedly unlinked. O_LIMIT_PARENT states will be kept
* in the expired lists until reference counter become zero.
*/
#define DYN_UNLINK_STATES(s, prev, next, exp, af, name, extra) do { \
length = 0; \
removed = 0; \
prev = NULL; \
s = CK_SLIST_FIRST(&V_dyn_ ## name [bucket]); \
while (s != NULL) { \
next = CK_SLIST_NEXT(s, entry); \
if ((TIME_LEQ((s)->exp, time_uptime) && extra) || \
(rt != NULL && \
dyn_match_ ## af ## _state(ch, s, rt))) { \
if (prev != NULL) \
CK_SLIST_REMOVE_AFTER(prev, entry); \
else \
CK_SLIST_REMOVE_HEAD( \
&V_dyn_ ## name [bucket], entry); \
removed++; \
SLIST_INSERT_HEAD(&expired_ ## af, s, expired); \
if (s->type == O_LIMIT_PARENT) \
DYN_COUNT_DEC(dyn_parent_count); \
else { \
DYN_COUNT_DEC(dyn_count); \
if (s->data->flags & DYN_REFERENCED) { \
rule = s->data->parent; \
if (s->type == O_LIMIT) \
rule = ((__typeof(s)) \
rule)->limit->parent;\
dyn_release_rule(ch, s->data, \
rule, s->kidx); \
} \
if (s->type == O_LIMIT) { \
s = s->data->parent; \
DPARENT_COUNT_DEC(s->limit); \
} \
} \
} else { \
prev = s; \
length++; \
} \
s = next; \
} \
if (removed != 0) \
DYN_BUCKET_VERSION_BUMP(bucket, name ## _del); \
if (length > max_length) \
max_length = length; \
} while (0)
SLIST_INIT(&expired_ipv4);
#ifdef INET6
SLIST_INIT(&expired_ipv6);
#endif
max_length = 0;
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
DYN_BUCKET_LOCK(bucket);
DYN_UNLINK_STATES(s4, s4p, s4n, data->expire, ipv4, ipv4, 1);
DYN_UNLINK_STATES(s4, s4p, s4n, limit->expire, ipv4,
ipv4_parent, (s4->limit->count == 0));
#ifdef INET6
DYN_UNLINK_STATES(s6, s6p, s6n, data->expire, ipv6, ipv6, 1);
DYN_UNLINK_STATES(s6, s6p, s6n, limit->expire, ipv6,
ipv6_parent, (s6->limit->count == 0));
#endif
DYN_BUCKET_UNLOCK(bucket);
}
/* Update curr_max_length for statistics. */
V_curr_max_length = max_length;
/*
* Concatenate temporary lists with global expired lists.
*/
DYN_EXPIRED_LOCK();
SLIST_CONCAT(&V_dyn_expired_ipv4, &expired_ipv4,
dyn_ipv4_state, expired);
#ifdef INET6
SLIST_CONCAT(&V_dyn_expired_ipv6, &expired_ipv6,
dyn_ipv6_state, expired);
#endif
DYN_EXPIRED_UNLOCK();
#undef DYN_UNLINK_STATES
#undef DYN_UNREF_STATES
}
static struct mbuf *
dyn_mgethdr(int len, uint16_t fibnum)
{
struct mbuf *m;
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL)
return (NULL);
#ifdef MAC
mac_netinet_firewall_send(m);
#endif
M_SETFIB(m, fibnum);
m->m_data += max_linkhdr;
m->m_flags |= M_SKIP_FIREWALL;
m->m_len = m->m_pkthdr.len = len;
bzero(m->m_data, len);
return (m);
}
static void
dyn_make_keepalive_ipv4(struct mbuf *m, in_addr_t src, in_addr_t dst,
uint32_t seq, uint32_t ack, uint16_t sport, uint16_t dport)
{
struct tcphdr *tcp;
struct ip *ip;
ip = mtod(m, struct ip *);
ip->ip_v = 4;
ip->ip_hl = sizeof(*ip) >> 2;
ip->ip_tos = IPTOS_LOWDELAY;
ip->ip_len = htons(m->m_len);
ip->ip_off |= htons(IP_DF);
ip->ip_ttl = V_ip_defttl;
ip->ip_p = IPPROTO_TCP;
ip->ip_src.s_addr = htonl(src);
ip->ip_dst.s_addr = htonl(dst);
tcp = mtodo(m, sizeof(struct ip));
tcp->th_sport = htons(sport);
tcp->th_dport = htons(dport);
tcp->th_off = sizeof(struct tcphdr) >> 2;
tcp->th_seq = htonl(seq);
tcp->th_ack = htonl(ack);
tcp->th_flags = TH_ACK;
tcp->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
htons(sizeof(struct tcphdr) + IPPROTO_TCP));
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
m->m_pkthdr.csum_flags = CSUM_TCP;
}
static void
dyn_enqueue_keepalive_ipv4(struct mbufq *q, const struct dyn_ipv4_state *s)
{
struct mbuf *m;
if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
s->data->fibnum);
if (m != NULL) {
dyn_make_keepalive_ipv4(m, s->dst, s->src,
s->data->ack_fwd - 1, s->data->ack_rev,
s->dport, s->sport);
if (mbufq_enqueue(q, m)) {
m_freem(m);
log(LOG_DEBUG, "ipfw: limit for IPv4 "
"keepalive queue is reached.\n");
return;
}
}
}
if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
m = dyn_mgethdr(sizeof(struct ip) + sizeof(struct tcphdr),
s->data->fibnum);
if (m != NULL) {
dyn_make_keepalive_ipv4(m, s->src, s->dst,
s->data->ack_rev - 1, s->data->ack_fwd,
s->sport, s->dport);
if (mbufq_enqueue(q, m)) {
m_freem(m);
log(LOG_DEBUG, "ipfw: limit for IPv4 "
"keepalive queue is reached.\n");
return;
}
}
}
}
/*
* Prepare and send keep-alive packets.
*/
static void
dyn_send_keepalive_ipv4(struct ip_fw_chain *chain)
{
struct mbufq q;
struct mbuf *m;
struct dyn_ipv4_state *s;
uint32_t bucket;
mbufq_init(&q, INT_MAX);
IPFW_UH_RLOCK(chain);
/*
* It is safe to not use hazard pointer and just do lockless
* access to the lists, because states entries can not be deleted
* while we hold IPFW_UH_RLOCK.
*/
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
CK_SLIST_FOREACH(s, &V_dyn_ipv4[bucket], entry) {
/*
* Only established TCP connections that will
* become expired withing dyn_keepalive_interval.
*/
if (s->proto != IPPROTO_TCP ||
(s->data->state & BOTH_SYN) != BOTH_SYN ||
TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
s->data->expire))
continue;
dyn_enqueue_keepalive_ipv4(&q, s);
}
}
IPFW_UH_RUNLOCK(chain);
while ((m = mbufq_dequeue(&q)) != NULL)
ip_output(m, NULL, NULL, 0, NULL, NULL);
}
#ifdef INET6
static void
dyn_make_keepalive_ipv6(struct mbuf *m, const struct in6_addr *src,
const struct in6_addr *dst, uint32_t zoneid, uint32_t seq, uint32_t ack,
uint16_t sport, uint16_t dport)
{
struct tcphdr *tcp;
struct ip6_hdr *ip6;
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_vfc |= IPV6_VERSION;
ip6->ip6_plen = htons(sizeof(struct tcphdr));
ip6->ip6_nxt = IPPROTO_TCP;
ip6->ip6_hlim = IPV6_DEFHLIM;
ip6->ip6_src = *src;
if (IN6_IS_ADDR_LINKLOCAL(src))
ip6->ip6_src.s6_addr16[1] = htons(zoneid & 0xffff);
ip6->ip6_dst = *dst;
if (IN6_IS_ADDR_LINKLOCAL(dst))
ip6->ip6_dst.s6_addr16[1] = htons(zoneid & 0xffff);
tcp = mtodo(m, sizeof(struct ip6_hdr));
tcp->th_sport = htons(sport);
tcp->th_dport = htons(dport);
tcp->th_off = sizeof(struct tcphdr) >> 2;
tcp->th_seq = htonl(seq);
tcp->th_ack = htonl(ack);
tcp->th_flags = TH_ACK;
tcp->th_sum = in6_cksum_pseudo(ip6, sizeof(struct tcphdr),
IPPROTO_TCP, 0);
m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
}
static void
dyn_enqueue_keepalive_ipv6(struct mbufq *q, const struct dyn_ipv6_state *s)
{
struct mbuf *m;
if ((s->data->state & ACK_FWD) == 0 && s->data->ack_fwd > 0) {
m = dyn_mgethdr(sizeof(struct ip6_hdr) +
sizeof(struct tcphdr), s->data->fibnum);
if (m != NULL) {
dyn_make_keepalive_ipv6(m, &s->dst, &s->src,
s->zoneid, s->data->ack_fwd - 1, s->data->ack_rev,
s->dport, s->sport);
if (mbufq_enqueue(q, m)) {
m_freem(m);
log(LOG_DEBUG, "ipfw: limit for IPv6 "
"keepalive queue is reached.\n");
return;
}
}
}
if ((s->data->state & ACK_REV) == 0 && s->data->ack_rev > 0) {
m = dyn_mgethdr(sizeof(struct ip6_hdr) +
sizeof(struct tcphdr), s->data->fibnum);
if (m != NULL) {
dyn_make_keepalive_ipv6(m, &s->src, &s->dst,
s->zoneid, s->data->ack_rev - 1, s->data->ack_fwd,
s->sport, s->dport);
if (mbufq_enqueue(q, m)) {
m_freem(m);
log(LOG_DEBUG, "ipfw: limit for IPv6 "
"keepalive queue is reached.\n");
return;
}
}
}
}
static void
dyn_send_keepalive_ipv6(struct ip_fw_chain *chain)
{
struct mbufq q;
struct mbuf *m;
struct dyn_ipv6_state *s;
uint32_t bucket;
mbufq_init(&q, INT_MAX);
IPFW_UH_RLOCK(chain);
/*
* It is safe to not use hazard pointer and just do lockless
* access to the lists, because states entries can not be deleted
* while we hold IPFW_UH_RLOCK.
*/
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
CK_SLIST_FOREACH(s, &V_dyn_ipv6[bucket], entry) {
/*
* Only established TCP connections that will
* become expired withing dyn_keepalive_interval.
*/
if (s->proto != IPPROTO_TCP ||
(s->data->state & BOTH_SYN) != BOTH_SYN ||
TIME_LEQ(time_uptime + V_dyn_keepalive_interval,
s->data->expire))
continue;
dyn_enqueue_keepalive_ipv6(&q, s);
}
}
IPFW_UH_RUNLOCK(chain);
while ((m = mbufq_dequeue(&q)) != NULL)
ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
}
#endif /* INET6 */
static void
dyn_grow_hashtable(struct ip_fw_chain *chain, uint32_t new)
{
#ifdef INET6
struct dyn_ipv6ck_slist *ipv6, *ipv6_parent;
uint32_t *ipv6_add, *ipv6_del, *ipv6_parent_add, *ipv6_parent_del;
struct dyn_ipv6_state *s6;
#endif
struct dyn_ipv4ck_slist *ipv4, *ipv4_parent;
uint32_t *ipv4_add, *ipv4_del, *ipv4_parent_add, *ipv4_parent_del;
struct dyn_ipv4_state *s4;
struct mtx *bucket_lock;
void *tmp;
uint32_t bucket;
MPASS(powerof2(new));
DYN_DEBUG("grow hash size %u -> %u", V_curr_dyn_buckets, new);
/*
* Allocate and initialize new lists.
* XXXAE: on memory pressure this can disable callout timer.
*/
bucket_lock = malloc(new * sizeof(struct mtx), M_IPFW,
M_WAITOK | M_ZERO);
ipv4 = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
M_WAITOK | M_ZERO);
ipv4_parent = malloc(new * sizeof(struct dyn_ipv4ck_slist), M_IPFW,
M_WAITOK | M_ZERO);
ipv4_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
ipv4_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
ipv4_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
M_WAITOK | M_ZERO);
ipv4_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
M_WAITOK | M_ZERO);
#ifdef INET6
ipv6 = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
M_WAITOK | M_ZERO);
ipv6_parent = malloc(new * sizeof(struct dyn_ipv6ck_slist), M_IPFW,
M_WAITOK | M_ZERO);
ipv6_add = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
ipv6_del = malloc(new * sizeof(uint32_t), M_IPFW, M_WAITOK | M_ZERO);
ipv6_parent_add = malloc(new * sizeof(uint32_t), M_IPFW,
M_WAITOK | M_ZERO);
ipv6_parent_del = malloc(new * sizeof(uint32_t), M_IPFW,
M_WAITOK | M_ZERO);
#endif
for (bucket = 0; bucket < new; bucket++) {
DYN_BUCKET_LOCK_INIT(bucket_lock, bucket);
CK_SLIST_INIT(&ipv4[bucket]);
CK_SLIST_INIT(&ipv4_parent[bucket]);
#ifdef INET6
CK_SLIST_INIT(&ipv6[bucket]);
CK_SLIST_INIT(&ipv6_parent[bucket]);
#endif
}
#define DYN_RELINK_STATES(s, hval, i, head, ohead) do { \
while ((s = CK_SLIST_FIRST(&V_dyn_ ## ohead[i])) != NULL) { \
CK_SLIST_REMOVE_HEAD(&V_dyn_ ## ohead[i], entry); \
CK_SLIST_INSERT_HEAD(&head[DYN_BUCKET(s->hval, new)], \
s, entry); \
} \
} while (0)
/*
* Prevent rules changing from userland.
*/
IPFW_UH_WLOCK(chain);
/*
* Hold traffic processing until we finish resize to
* prevent access to states lists.
*/
IPFW_WLOCK(chain);
/* Re-link all dynamic states */
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
DYN_RELINK_STATES(s4, data->hashval, bucket, ipv4, ipv4);
DYN_RELINK_STATES(s4, limit->hashval, bucket, ipv4_parent,
ipv4_parent);
#ifdef INET6
DYN_RELINK_STATES(s6, data->hashval, bucket, ipv6, ipv6);
DYN_RELINK_STATES(s6, limit->hashval, bucket, ipv6_parent,
ipv6_parent);
#endif
}
#define DYN_SWAP_PTR(old, new, tmp) do { \
tmp = old; \
old = new; \
new = tmp; \
} while (0)
/* Swap pointers */
DYN_SWAP_PTR(V_dyn_bucket_lock, bucket_lock, tmp);
DYN_SWAP_PTR(V_dyn_ipv4, ipv4, tmp);
DYN_SWAP_PTR(V_dyn_ipv4_parent, ipv4_parent, tmp);
DYN_SWAP_PTR(V_dyn_ipv4_add, ipv4_add, tmp);
DYN_SWAP_PTR(V_dyn_ipv4_parent_add, ipv4_parent_add, tmp);
DYN_SWAP_PTR(V_dyn_ipv4_del, ipv4_del, tmp);
DYN_SWAP_PTR(V_dyn_ipv4_parent_del, ipv4_parent_del, tmp);
#ifdef INET6
DYN_SWAP_PTR(V_dyn_ipv6, ipv6, tmp);
DYN_SWAP_PTR(V_dyn_ipv6_parent, ipv6_parent, tmp);
DYN_SWAP_PTR(V_dyn_ipv6_add, ipv6_add, tmp);
DYN_SWAP_PTR(V_dyn_ipv6_parent_add, ipv6_parent_add, tmp);
DYN_SWAP_PTR(V_dyn_ipv6_del, ipv6_del, tmp);
DYN_SWAP_PTR(V_dyn_ipv6_parent_del, ipv6_parent_del, tmp);
#endif
bucket = V_curr_dyn_buckets;
V_curr_dyn_buckets = new;
IPFW_WUNLOCK(chain);
IPFW_UH_WUNLOCK(chain);
/* Release old resources */
while (bucket-- != 0)
DYN_BUCKET_LOCK_DESTROY(bucket_lock, bucket);
free(bucket_lock, M_IPFW);
free(ipv4, M_IPFW);
free(ipv4_parent, M_IPFW);
free(ipv4_add, M_IPFW);
free(ipv4_parent_add, M_IPFW);
free(ipv4_del, M_IPFW);
free(ipv4_parent_del, M_IPFW);
#ifdef INET6
free(ipv6, M_IPFW);
free(ipv6_parent, M_IPFW);
free(ipv6_add, M_IPFW);
free(ipv6_parent_add, M_IPFW);
free(ipv6_del, M_IPFW);
free(ipv6_parent_del, M_IPFW);
#endif
}
/*
* This function is used to perform various maintenance
* on dynamic hash lists. Currently it is called every second.
*/
static void
dyn_tick(void *vnetx)
{
uint32_t buckets;
CURVNET_SET((struct vnet *)vnetx);
/*
* First free states unlinked in previous passes.
*/
dyn_free_states(&V_layer3_chain);
/*
* Now unlink others expired states.
* We use IPFW_UH_WLOCK to avoid concurrent call of
* dyn_expire_states(). It is the only function that does
* deletion of state entries from states lists.
*/
IPFW_UH_WLOCK(&V_layer3_chain);
dyn_expire_states(&V_layer3_chain, NULL);
IPFW_UH_WUNLOCK(&V_layer3_chain);
/*
* Send keepalives if they are enabled and the time has come.
*/
if (V_dyn_keepalive != 0 &&
V_dyn_keepalive_last + V_dyn_keepalive_period <= time_uptime) {
V_dyn_keepalive_last = time_uptime;
dyn_send_keepalive_ipv4(&V_layer3_chain);
#ifdef INET6
dyn_send_keepalive_ipv6(&V_layer3_chain);
#endif
}
/*
* Check if we need to resize the hash:
* if current number of states exceeds number of buckets in hash,
* and dyn_buckets_max permits to grow the number of buckets, then
* do it. Grow hash size to the minimum power of 2 which is bigger
* than current states count.
*/
if (V_curr_dyn_buckets < V_dyn_buckets_max &&
(V_curr_dyn_buckets < V_dyn_count / 2 || (
V_curr_dyn_buckets < V_dyn_count && V_curr_max_length > 8))) {
buckets = 1 << fls(V_dyn_count);
if (buckets > V_dyn_buckets_max)
buckets = V_dyn_buckets_max;
dyn_grow_hashtable(&V_layer3_chain, buckets);
}
callout_reset_on(&V_dyn_timeout, hz, dyn_tick, vnetx, 0);
CURVNET_RESTORE();
}
void
ipfw_expire_dyn_states(struct ip_fw_chain *chain, ipfw_range_tlv *rt)
{
/*
* Do not perform any checks if we currently have no dynamic states
*/
if (V_dyn_count == 0)
return;
IPFW_UH_WLOCK_ASSERT(chain);
dyn_expire_states(chain, rt);
}
/*
* Pass through all states and reset eaction for orphaned rules.
*/
void
ipfw_dyn_reset_eaction(struct ip_fw_chain *ch, uint16_t eaction_id,
uint16_t default_id, uint16_t instance_id)
{
#ifdef INET6
struct dyn_ipv6_state *s6;
#endif
struct dyn_ipv4_state *s4;
struct ip_fw *rule;
uint32_t bucket;
#define DYN_RESET_EACTION(s, h, b) \
CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \
if ((s->data->flags & DYN_REFERENCED) == 0) \
continue; \
rule = s->data->parent; \
if (s->type == O_LIMIT) \
rule = ((__typeof(s))rule)->limit->parent; \
ipfw_reset_eaction(ch, rule, eaction_id, \
default_id, instance_id); \
}
IPFW_UH_WLOCK_ASSERT(ch);
if (V_dyn_count == 0)
return;
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
DYN_RESET_EACTION(s4, ipv4, bucket);
#ifdef INET6
DYN_RESET_EACTION(s6, ipv6, bucket);
#endif
}
}
/*
* Returns size of dynamic states in legacy format
*/
int
ipfw_dyn_len(void)
{
return ((V_dyn_count + V_dyn_parent_count) * sizeof(ipfw_dyn_rule));
}
/*
* Returns number of dynamic states.
* Marks every named object index used by dynamic states with bit in @bmask.
* Returns number of named objects accounted in bmask via @nocnt.
* Used by dump format v1 (current).
*/
uint32_t
ipfw_dyn_get_count(uint32_t *bmask, int *nocnt)
{
#ifdef INET6
struct dyn_ipv6_state *s6;
#endif
struct dyn_ipv4_state *s4;
uint32_t bucket;
#define DYN_COUNT_OBJECTS(s, h, b) \
CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \
MPASS(s->kidx != 0); \
if (ipfw_mark_object_kidx(bmask, IPFW_TLV_STATE_NAME, \
s->kidx) != 0) \
(*nocnt)++; \
}
IPFW_UH_RLOCK_ASSERT(&V_layer3_chain);
/* No need to pass through all the buckets. */
*nocnt = 0;
if (V_dyn_count + V_dyn_parent_count == 0)
return (0);
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
DYN_COUNT_OBJECTS(s4, ipv4, bucket);
#ifdef INET6
DYN_COUNT_OBJECTS(s6, ipv6, bucket);
#endif
}
return (V_dyn_count + V_dyn_parent_count);
}
/*
* Check if rule contains at least one dynamic opcode.
*
* Returns 1 if such opcode is found, 0 otherwise.
*/
int
ipfw_is_dyn_rule(struct ip_fw *rule)
{
int cmdlen, l;
ipfw_insn *cmd;
l = rule->cmd_len;
cmd = rule->cmd;
cmdlen = 0;
for ( ; l > 0 ; l -= cmdlen, cmd += cmdlen) {
cmdlen = F_LEN(cmd);
switch (cmd->opcode) {
case O_LIMIT:
case O_KEEP_STATE:
case O_PROBE_STATE:
case O_CHECK_STATE:
return (1);
}
}
return (0);
}
static void
dyn_export_parent(const struct dyn_parent *p, uint16_t kidx, uint8_t set,
ipfw_dyn_rule *dst)
{
dst->dyn_type = O_LIMIT_PARENT;
dst->kidx = kidx;
dst->count = (uint16_t)DPARENT_COUNT(p);
dst->expire = TIME_LEQ(p->expire, time_uptime) ? 0:
p->expire - time_uptime;
/* 'rule' is used to pass up the rule number and set */
memcpy(&dst->rule, &p->rulenum, sizeof(p->rulenum));
/* store set number into high word of dst->rule pointer. */
memcpy((char *)&dst->rule + sizeof(p->rulenum), &set, sizeof(set));
/* unused fields */
dst->pcnt = 0;
dst->bcnt = 0;
dst->parent = NULL;
dst->state = 0;
dst->ack_fwd = 0;
dst->ack_rev = 0;
dst->bucket = p->hashval;
/*
* The legacy userland code will interpret a NULL here as a marker
* for the last dynamic rule.
*/
dst->next = (ipfw_dyn_rule *)1;
}
static void
dyn_export_data(const struct dyn_data *data, uint16_t kidx, uint8_t type,
uint8_t set, ipfw_dyn_rule *dst)
{
dst->dyn_type = type;
dst->kidx = kidx;
dst->pcnt = data->pcnt_fwd + data->pcnt_rev;
dst->bcnt = data->bcnt_fwd + data->bcnt_rev;
dst->expire = TIME_LEQ(data->expire, time_uptime) ? 0:
data->expire - time_uptime;
/* 'rule' is used to pass up the rule number and set */
memcpy(&dst->rule, &data->rulenum, sizeof(data->rulenum));
/* store set number into high word of dst->rule pointer. */
memcpy((char *)&dst->rule + sizeof(data->rulenum), &set, sizeof(set));
dst->state = data->state;
if (data->flags & DYN_REFERENCED)
dst->state |= IPFW_DYN_ORPHANED;
/* unused fields */
dst->parent = NULL;
dst->ack_fwd = data->ack_fwd;
dst->ack_rev = data->ack_rev;
dst->count = 0;
dst->bucket = data->hashval;
/*
* The legacy userland code will interpret a NULL here as a marker
* for the last dynamic rule.
*/
dst->next = (ipfw_dyn_rule *)1;
}
static void
dyn_export_ipv4_state(const struct dyn_ipv4_state *s, ipfw_dyn_rule *dst)
{
struct ip_fw *rule;
switch (s->type) {
case O_LIMIT_PARENT:
rule = s->limit->parent;
dyn_export_parent(s->limit, s->kidx, rule->set, dst);
break;
default:
rule = s->data->parent;
if (s->type == O_LIMIT)
rule = ((struct dyn_ipv4_state *)rule)->limit->parent;
dyn_export_data(s->data, s->kidx, s->type, rule->set, dst);
}
dst->id.dst_ip = s->dst;
dst->id.src_ip = s->src;
dst->id.dst_port = s->dport;
dst->id.src_port = s->sport;
dst->id.fib = s->data->fibnum;
dst->id.proto = s->proto;
dst->id._flags = 0;
dst->id.addr_type = 4;
memset(&dst->id.dst_ip6, 0, sizeof(dst->id.dst_ip6));
memset(&dst->id.src_ip6, 0, sizeof(dst->id.src_ip6));
dst->id.flow_id6 = dst->id.extra = 0;
}
#ifdef INET6
static void
dyn_export_ipv6_state(const struct dyn_ipv6_state *s, ipfw_dyn_rule *dst)
{
struct ip_fw *rule;
switch (s->type) {
case O_LIMIT_PARENT:
rule = s->limit->parent;
dyn_export_parent(s->limit, s->kidx, rule->set, dst);
break;
default:
rule = s->data->parent;
if (s->type == O_LIMIT)
rule = ((struct dyn_ipv6_state *)rule)->limit->parent;
dyn_export_data(s->data, s->kidx, s->type, rule->set, dst);
}
dst->id.src_ip6 = s->src;
dst->id.dst_ip6 = s->dst;
dst->id.dst_port = s->dport;
dst->id.src_port = s->sport;
dst->id.fib = s->data->fibnum;
dst->id.proto = s->proto;
dst->id._flags = 0;
dst->id.addr_type = 6;
dst->id.dst_ip = dst->id.src_ip = 0;
dst->id.flow_id6 = dst->id.extra = 0;
}
#endif /* INET6 */
/*
* Fills the buffer given by @sd with dynamic states.
* Used by dump format v1 (current).
*
* Returns 0 on success.
*/
int
ipfw_dump_states(struct ip_fw_chain *chain, struct sockopt_data *sd)
{
#ifdef INET6
struct dyn_ipv6_state *s6;
#endif
struct dyn_ipv4_state *s4;
ipfw_obj_dyntlv *dst, *last;
ipfw_obj_ctlv *ctlv;
uint32_t bucket;
if (V_dyn_count == 0)
return (0);
/*
* IPFW_UH_RLOCK garantees that another userland request
* and callout thread will not delete entries from states
* lists.
*/
IPFW_UH_RLOCK_ASSERT(chain);
ctlv = (ipfw_obj_ctlv *)ipfw_get_sopt_space(sd, sizeof(*ctlv));
if (ctlv == NULL)
return (ENOMEM);
ctlv->head.type = IPFW_TLV_DYNSTATE_LIST;
ctlv->objsize = sizeof(ipfw_obj_dyntlv);
last = NULL;
#define DYN_EXPORT_STATES(s, af, h, b) \
CK_SLIST_FOREACH(s, &V_dyn_ ## h[b], entry) { \
dst = (ipfw_obj_dyntlv *)ipfw_get_sopt_space(sd, \
sizeof(ipfw_obj_dyntlv)); \
if (dst == NULL) \
return (ENOMEM); \
dyn_export_ ## af ## _state(s, &dst->state); \
dst->head.length = sizeof(ipfw_obj_dyntlv); \
dst->head.type = IPFW_TLV_DYN_ENT; \
last = dst; \
}
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
#ifdef INET6
DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
#endif /* INET6 */
}
/* mark last dynamic rule */
if (last != NULL)
last->head.flags = IPFW_DF_LAST; /* XXX: unused */
return (0);
#undef DYN_EXPORT_STATES
}
/*
* Fill given buffer with dynamic states (legacy format).
* IPFW_UH_RLOCK has to be held while calling.
*/
void
ipfw_get_dynamic(struct ip_fw_chain *chain, char **pbp, const char *ep)
{
#ifdef INET6
struct dyn_ipv6_state *s6;
#endif
struct dyn_ipv4_state *s4;
ipfw_dyn_rule *p, *last = NULL;
char *bp;
uint32_t bucket;
if (V_dyn_count == 0)
return;
bp = *pbp;
IPFW_UH_RLOCK_ASSERT(chain);
#define DYN_EXPORT_STATES(s, af, head, b) \
CK_SLIST_FOREACH(s, &V_dyn_ ## head[b], entry) { \
if (bp + sizeof(*p) > ep) \
break; \
p = (ipfw_dyn_rule *)bp; \
dyn_export_ ## af ## _state(s, p); \
last = p; \
bp += sizeof(*p); \
}
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
DYN_EXPORT_STATES(s4, ipv4, ipv4_parent, bucket);
DYN_EXPORT_STATES(s4, ipv4, ipv4, bucket);
#ifdef INET6
DYN_EXPORT_STATES(s6, ipv6, ipv6_parent, bucket);
DYN_EXPORT_STATES(s6, ipv6, ipv6, bucket);
#endif /* INET6 */
}
if (last != NULL) /* mark last dynamic rule */
last->next = NULL;
*pbp = bp;
#undef DYN_EXPORT_STATES
}
void
ipfw_dyn_init(struct ip_fw_chain *chain)
{
#ifdef IPFIREWALL_JENKINSHASH
V_dyn_hashseed = arc4random();
#endif
V_dyn_max = 16384; /* max # of states */
V_dyn_parent_max = 4096; /* max # of parent states */
V_dyn_buckets_max = 8192; /* must be power of 2 */
V_dyn_ack_lifetime = 300;
V_dyn_syn_lifetime = 20;
V_dyn_fin_lifetime = 1;
V_dyn_rst_lifetime = 1;
V_dyn_udp_lifetime = 10;
V_dyn_short_lifetime = 5;
V_dyn_keepalive_interval = 20;
V_dyn_keepalive_period = 5;
V_dyn_keepalive = 1; /* send keepalives */
V_dyn_keepalive_last = time_uptime;
V_dyn_data_zone = uma_zcreate("IPFW dynamic states data",
sizeof(struct dyn_data), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
uma_zone_set_max(V_dyn_data_zone, V_dyn_max);
V_dyn_parent_zone = uma_zcreate("IPFW parent dynamic states",
sizeof(struct dyn_parent), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
uma_zone_set_max(V_dyn_parent_zone, V_dyn_parent_max);
SLIST_INIT(&V_dyn_expired_ipv4);
V_dyn_ipv4 = NULL;
V_dyn_ipv4_parent = NULL;
V_dyn_ipv4_zone = uma_zcreate("IPFW IPv4 dynamic states",
sizeof(struct dyn_ipv4_state), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
#ifdef INET6
SLIST_INIT(&V_dyn_expired_ipv6);
V_dyn_ipv6 = NULL;
V_dyn_ipv6_parent = NULL;
V_dyn_ipv6_zone = uma_zcreate("IPFW IPv6 dynamic states",
sizeof(struct dyn_ipv6_state), NULL, NULL, NULL, NULL,
UMA_ALIGN_PTR, 0);
#endif
/* Initialize buckets. */
V_curr_dyn_buckets = 0;
V_dyn_bucket_lock = NULL;
dyn_grow_hashtable(chain, 256);
if (IS_DEFAULT_VNET(curvnet))
dyn_hp_cache = malloc(mp_ncpus * sizeof(void *), M_IPFW,
M_WAITOK | M_ZERO);
DYN_EXPIRED_LOCK_INIT();
callout_init(&V_dyn_timeout, 1);
callout_reset(&V_dyn_timeout, hz, dyn_tick, curvnet);
IPFW_ADD_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
}
void
ipfw_dyn_uninit(int pass)
{
#ifdef INET6
struct dyn_ipv6_state *s6;
#endif
struct dyn_ipv4_state *s4;
int bucket;
if (pass == 0) {
callout_drain(&V_dyn_timeout);
return;
}
IPFW_DEL_OBJ_REWRITER(IS_DEFAULT_VNET(curvnet), dyn_opcodes);
DYN_EXPIRED_LOCK_DESTROY();
#define DYN_FREE_STATES_FORCED(CK, s, af, name, en) do { \
while ((s = CK ## SLIST_FIRST(&V_dyn_ ## name)) != NULL) { \
CK ## SLIST_REMOVE_HEAD(&V_dyn_ ## name, en); \
if (s->type == O_LIMIT_PARENT) \
uma_zfree(V_dyn_parent_zone, s->limit); \
else \
uma_zfree(V_dyn_data_zone, s->data); \
uma_zfree(V_dyn_ ## af ## _zone, s); \
} \
} while (0)
for (bucket = 0; bucket < V_curr_dyn_buckets; bucket++) {
DYN_BUCKET_LOCK_DESTROY(V_dyn_bucket_lock, bucket);
DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4[bucket], entry);
DYN_FREE_STATES_FORCED(CK_, s4, ipv4, ipv4_parent[bucket],
entry);
#ifdef INET6
DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6[bucket], entry);
DYN_FREE_STATES_FORCED(CK_, s6, ipv6, ipv6_parent[bucket],
entry);
#endif /* INET6 */
}
DYN_FREE_STATES_FORCED(, s4, ipv4, expired_ipv4, expired);
#ifdef INET6
DYN_FREE_STATES_FORCED(, s6, ipv6, expired_ipv6, expired);
#endif
#undef DYN_FREE_STATES_FORCED
uma_zdestroy(V_dyn_ipv4_zone);
uma_zdestroy(V_dyn_data_zone);
uma_zdestroy(V_dyn_parent_zone);
#ifdef INET6
uma_zdestroy(V_dyn_ipv6_zone);
free(V_dyn_ipv6, M_IPFW);
free(V_dyn_ipv6_parent, M_IPFW);
free(V_dyn_ipv6_add, M_IPFW);
free(V_dyn_ipv6_parent_add, M_IPFW);
free(V_dyn_ipv6_del, M_IPFW);
free(V_dyn_ipv6_parent_del, M_IPFW);
#endif
free(V_dyn_bucket_lock, M_IPFW);
free(V_dyn_ipv4, M_IPFW);
free(V_dyn_ipv4_parent, M_IPFW);
free(V_dyn_ipv4_add, M_IPFW);
free(V_dyn_ipv4_parent_add, M_IPFW);
free(V_dyn_ipv4_del, M_IPFW);
free(V_dyn_ipv4_parent_del, M_IPFW);
if (IS_DEFAULT_VNET(curvnet))
free(dyn_hp_cache, M_IPFW);
}
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