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Diffstat (limited to 'include/net/netfilter/nf_conntrack.h')
| -rw-r--r-- | include/net/netfilter/nf_conntrack.h | 372 |
1 files changed, 372 insertions, 0 deletions
diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h new file mode 100644 index 000000000..6a2019aaa --- /dev/null +++ b/include/net/netfilter/nf_conntrack.h @@ -0,0 +1,372 @@ +/* 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 <yasuyuki.kozakai@toshiba.co.jp> + * - 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_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); +} + +/* Alter reply tuple (maybe alter helper). */ +void nf_conntrack_alter_reply(struct nf_conn *ct, + const struct nf_conntrack_tuple *newreply); + +/* 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); + +/* 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); +} + +/* Protocol module loading */ +int nf_ct_l3proto_try_module_get(unsigned short l3proto); +void nf_ct_l3proto_module_put(unsigned short l3proto); + +/* 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; +} + +#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); +} + +#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 */ |