/* SPDX-License-Identifier: GPL-2.0 */
/*
* Connection state tracking for netfilter. This is separated from,
* but required by, the (future) NAT layer; it can also be used by an iptables
* extension.
*
* 16 Dec 2003: Yasuyuki Kozakai @USAGI <[email protected]>
* - generalize L3 protocol dependent part.
*
* Derived from include/linux/netfiter_ipv4/ip_conntrack.h
*/
#ifndef _NF_CONNTRACK_H
#define _NF_CONNTRACK_H
#include <linux/bitops.h>
#include <linux/compiler.h>
#include <linux/netfilter/nf_conntrack_common.h>
#include <linux/netfilter/nf_conntrack_tcp.h>
#include <linux/netfilter/nf_conntrack_dccp.h>
#include <linux/netfilter/nf_conntrack_sctp.h>
#include <linux/netfilter/nf_conntrack_proto_gre.h>
#include <net/netfilter/nf_conntrack_tuple.h>
struct nf_ct_udp {
unsigned long stream_ts;
};
/* per conntrack: protocol private data */
union nf_conntrack_proto {
/* insert conntrack proto private data here */
struct nf_ct_dccp dccp;
struct ip_ct_sctp sctp;
struct ip_ct_tcp tcp;
struct nf_ct_udp udp;
struct nf_ct_gre gre;
unsigned int tmpl_padto;
};
union nf_conntrack_expect_proto {
/* insert expect proto private data here */
};
struct nf_conntrack_net_ecache {
struct delayed_work dwork;
spinlock_t dying_lock;
struct hlist_nulls_head dying_list;
};
struct nf_conntrack_net {
/* only used when new connection is allocated: */
atomic_t count;
unsigned int expect_count;
/* only used from work queues, configuration plane, and so on: */
unsigned int users4;
unsigned int users6;
unsigned int users_bridge;
#ifdef CONFIG_SYSCTL
struct ctl_table_header *sysctl_header;
#endif
#ifdef CONFIG_NF_CONNTRACK_EVENTS
struct nf_conntrack_net_ecache ecache;
#endif
};
#include <linux/types.h>
#include <linux/skbuff.h>
#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
#include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
struct nf_conn {
/* Usage count in here is 1 for hash table, 1 per skb,
* plus 1 for any connection(s) we are `master' for
*
* Hint, SKB address this struct and refcnt via skb->_nfct and
* helpers nf_conntrack_get() and nf_conntrack_put().
* Helper nf_ct_put() equals nf_conntrack_put() by dec refcnt,
* except that the latter uses internal indirection and does not
* result in a conntrack module dependency.
* beware nf_ct_get() is different and don't inc refcnt.
*/
struct nf_conntrack ct_general;
spinlock_t lock;
/* jiffies32 when this ct is considered dead */
u32 timeout;
#ifdef CONFIG_NF_CONNTRACK_ZONES
struct nf_conntrack_zone zone;
#endif
/* XXX should I move this to the tail ? - Y.K */
/* These are my tuples; original and reply */
struct nf_conntrack_tuple_hash tuplehash[IP_CT_DIR_MAX];
/* Have we seen traffic both ways yet? (bitset) */
unsigned long status;
possible_net_t ct_net;
#if IS_ENABLED(CONFIG_NF_NAT)
struct hlist_node nat_bysource;
#endif
/* all members below initialized via memset */
struct { } __nfct_init_offset;
/* If we were expected by an expectation, this will be it */
struct nf_conn *master;
#if defined(CONFIG_NF_CONNTRACK_MARK)
u_int32_t mark;
#endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK
u_int32_t secmark;
#endif
/* Extensions */
struct nf_ct_ext *ext;
/* Storage reserved for other modules, must be the last member */
union nf_conntrack_proto proto;
};
static inline struct nf_conn *
nf_ct_to_nf_conn(const struct nf_conntrack *nfct)
{
return container_of(nfct, struct nf_conn, ct_general);
}
static inline struct nf_conn *
nf_ct_tuplehash_to_ctrack(const struct nf_conntrack_tuple_hash *hash)
{
return container_of(hash, struct nf_conn,
tuplehash[hash->tuple.dst.dir]);
}
static inline u_int16_t nf_ct_l3num(const struct nf_conn *ct)
{
return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.l3num;
}
static inline u_int8_t nf_ct_protonum(const struct nf_conn *ct)
{
return ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum;
}
#define nf_ct_tuple(ct, dir) (&(ct)->tuplehash[dir].tuple)
/* get master conntrack via master expectation */
#define master_ct(conntr) (conntr->master)
extern struct net init_net;
static inline struct net *nf_ct_net(const struct nf_conn *ct)
{
return read_pnet(&ct->ct_net);
}
/* Is this tuple taken? (ignoring any belonging to the given
conntrack). */
int nf_conntrack_tuple_taken(const struct nf_conntrack_tuple *tuple,
const struct nf_conn *ignored_conntrack);
/* Return conntrack_info and tuple hash for given skb. */
static inline struct nf_conn *
nf_ct_get(const struct sk_buff *skb, enum ip_conntrack_info *ctinfo)
{
unsigned long nfct = skb_get_nfct(skb);
*ctinfo = nfct & NFCT_INFOMASK;
return (struct nf_conn *)(nfct & NFCT_PTRMASK);
}
void nf_ct_destroy(struct nf_conntrack *nfct);
void nf_conntrack_tcp_set_closing(struct nf_conn *ct);
/* decrement reference count on a conntrack */
static inline void nf_ct_put(struct nf_conn *ct)
{
if (ct && refcount_dec_and_test(&ct->ct_general.use))
nf_ct_destroy(&ct->ct_general);
}
/* load module; enable/disable conntrack in this namespace */
int nf_ct_netns_get(struct net *net, u8 nfproto);
void nf_ct_netns_put(struct net *net, u8 nfproto);
/*
* Allocate a hashtable of hlist_head (if nulls == 0),
* or hlist_nulls_head (if nulls == 1)
*/
void *nf_ct_alloc_hashtable(unsigned int *sizep, int nulls);
int nf_conntrack_hash_check_insert(struct nf_conn *ct);
bool nf_ct_delete(struct nf_conn *ct, u32 pid, int report);
bool nf_ct_get_tuplepr(const struct sk_buff *skb, unsigned int nhoff,
u_int16_t l3num, struct net *net,
struct nf_conntrack_tuple *tuple);
void __nf_ct_refresh_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
const struct sk_buff *skb,
u32 extra_jiffies, bool do_acct);
/* Refresh conntrack for this many jiffies and do accounting */
static inline void nf_ct_refresh_acct(struct nf_conn *ct,
enum ip_conntrack_info ctinfo,
const struct sk_buff *skb,
u32 extra_jiffies)
{
__nf_ct_refresh_acct(ct, ctinfo, skb, extra_jiffies, true);
}
/* Refresh conntrack for this many jiffies */
static inline void nf_ct_refresh(struct nf_conn *ct,
const struct sk_buff *skb,
u32 extra_jiffies)
{
__nf_ct_refresh_acct(ct, 0, skb, extra_jiffies, false);
}
/* kill conntrack and do accounting */
bool nf_ct_kill_acct(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
const struct sk_buff *skb);
/* kill conntrack without accounting */
static inline bool nf_ct_kill(struct nf_conn *ct)
{
return nf_ct_delete(ct, 0, 0);
}
struct nf_ct_iter_data {
struct net *net;
void *data;
u32 portid;
int report;
};
/* Iterate over all conntracks: if iter returns true, it's deleted. */
void nf_ct_iterate_cleanup_net(int (*iter)(struct nf_conn *i, void *data),
const struct nf_ct_iter_data *iter_data);
/* also set unconfirmed conntracks as dying. Only use in module exit path. */
void nf_ct_iterate_destroy(int (*iter)(struct nf_conn *i, void *data),
void *data);
struct nf_conntrack_zone;
void nf_conntrack_free(struct nf_conn *ct);
struct nf_conn *nf_conntrack_alloc(struct net *net,
const struct nf_conntrack_zone *zone,
const struct nf_conntrack_tuple *orig,
const struct nf_conntrack_tuple *repl,
gfp_t gfp);
static inline int nf_ct_is_template(const struct nf_conn *ct)
{
return test_bit(IPS_TEMPLATE_BIT, &ct->status);
}
/* It's confirmed if it is, or has been in the hash table. */
static inline int nf_ct_is_confirmed(const struct nf_conn *ct)
{
return test_bit(IPS_CONFIRMED_BIT, &ct->status);
}
static inline int nf_ct_is_dying(const struct nf_conn *ct)
{
return test_bit(IPS_DYING_BIT, &ct->status);
}
/* Packet is received from loopback */
static inline bool nf_is_loopback_packet(const struct sk_buff *skb)
{
return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
}
static inline void nf_conntrack_alter_reply(struct nf_conn *ct,
const struct nf_conntrack_tuple *newreply)
{
/* Must be unconfirmed, so not in hash table yet */
if (WARN_ON(nf_ct_is_confirmed(ct)))
return;
ct->tuplehash[IP_CT_DIR_REPLY].tuple = *newreply;
}
#define nfct_time_stamp ((u32)(jiffies))
/* jiffies until ct expires, 0 if already expired */
static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
{
s32 timeout = READ_ONCE(ct->timeout) - nfct_time_stamp;
return max(timeout, 0);
}
static inline bool nf_ct_is_expired(const struct nf_conn *ct)
{
return (__s32)(READ_ONCE(ct->timeout) - nfct_time_stamp) <= 0;
}
/* use after obtaining a reference count */
static inline bool nf_ct_should_gc(const struct nf_conn *ct)
{
return nf_ct_is_expired(ct) && nf_ct_is_confirmed(ct) &&
!nf_ct_is_dying(ct);
}
#define NF_CT_DAY (86400 * HZ)
/* Set an arbitrary timeout large enough not to ever expire, this save
* us a check for the IPS_OFFLOAD_BIT from the packet path via
* nf_ct_is_expired().
*/
static inline void nf_ct_offload_timeout(struct nf_conn *ct)
{
if (nf_ct_expires(ct) < NF_CT_DAY / 2)
WRITE_ONCE(ct->timeout, nfct_time_stamp + NF_CT_DAY);
}
struct kernel_param;
int nf_conntrack_set_hashsize(const char *val, const struct kernel_param *kp);
int nf_conntrack_hash_resize(unsigned int hashsize);
extern struct hlist_nulls_head *nf_conntrack_hash;
extern unsigned int nf_conntrack_htable_size;
extern seqcount_spinlock_t nf_conntrack_generation;
extern unsigned int nf_conntrack_max;
/* must be called with rcu read lock held */
static inline void
nf_conntrack_get_ht(struct hlist_nulls_head **hash, unsigned int *hsize)
{
struct hlist_nulls_head *hptr;
unsigned int sequence, hsz;
do {
sequence = read_seqcount_begin(&nf_conntrack_generation);
hsz = nf_conntrack_htable_size;
hptr = nf_conntrack_hash;
} while (read_seqcount_retry(&nf_conntrack_generation, sequence));
*hash = hptr;
*hsize = hsz;
}
struct nf_conn *nf_ct_tmpl_alloc(struct net *net,
const struct nf_conntrack_zone *zone,
gfp_t flags);
void nf_ct_tmpl_free(struct nf_conn *tmpl);
u32 nf_ct_get_id(const struct nf_conn *ct);
u32 nf_conntrack_count(const struct net *net);
static inline void
nf_ct_set(struct sk_buff *skb, struct nf_conn *ct, enum ip_conntrack_info info)
{
skb_set_nfct(skb, (unsigned long)ct | info);
}
extern unsigned int nf_conntrack_net_id;
static inline struct nf_conntrack_net *nf_ct_pernet(const struct net *net)
{
return net_generic(net, nf_conntrack_net_id);
}
int nf_ct_skb_network_trim(struct sk_buff *skb, int family);
int nf_ct_handle_fragments(struct net *net, struct sk_buff *skb,
u16 zone, u8 family, u8 *proto, u16 *mru);
#define NF_CT_STAT_INC(net, count) __this_cpu_inc((net)->ct.stat->count)
#define NF_CT_STAT_INC_ATOMIC(net, count) this_cpu_inc((net)->ct.stat->count)
#define NF_CT_STAT_ADD_ATOMIC(net, count, v) this_cpu_add((net)->ct.stat->count, (v))
#define MODULE_ALIAS_NFCT_HELPER(helper) \
MODULE_ALIAS("nfct-helper-" helper)
#endif /* _NF_CONNTRACK_H */
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