nf_conntrack_ecache.h

  1/* SPDX-License-Identifier: GPL-2.0 */
  2/*
  3 * connection tracking event cache.
  4 */
  5
  6#ifndef _NF_CONNTRACK_ECACHE_H
  7#define _NF_CONNTRACK_ECACHE_H
  8#include <net/netfilter/nf_conntrack.h>
  9
 10#include <net/net_namespace.h>
 11#include <net/netfilter/nf_conntrack_expect.h>
 12#include <linux/netfilter/nf_conntrack_common.h>
 13#include <linux/netfilter/nf_conntrack_tuple_common.h>
 14#include <net/netfilter/nf_conntrack_extend.h>
 15#include <asm/local64.h>
 16
 17enum nf_ct_ecache_state {
 18	NFCT_ECACHE_DESTROY_FAIL,	/* tried but failed to send destroy event */
 19	NFCT_ECACHE_DESTROY_SENT,	/* sent destroy event after failure */
 20};
 21
 22struct nf_conntrack_ecache {
 23	unsigned long cache;		/* bitops want long */
 24#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
 25	local64_t timestamp;		/* event timestamp, in nanoseconds */
 26#endif
 27	u16 ctmask;			/* bitmask of ct events to be delivered */
 28	u16 expmask;			/* bitmask of expect events to be delivered */
 29	u32 missed;			/* missed events */
 30	u32 portid;			/* netlink portid of destroyer */
 31};
 32
 33static inline struct nf_conntrack_ecache *
 34nf_ct_ecache_find(const struct nf_conn *ct)
 35{
 36#ifdef CONFIG_NF_CONNTRACK_EVENTS
 37	return nf_ct_ext_find(ct, NF_CT_EXT_ECACHE);
 38#else
 39	return NULL;
 40#endif
 41}
 42
 43static inline bool nf_ct_ecache_exist(const struct nf_conn *ct)
 44{
 45#ifdef CONFIG_NF_CONNTRACK_EVENTS
 46	return nf_ct_ext_exist(ct, NF_CT_EXT_ECACHE);
 47#else
 48	return false;
 49#endif
 50}
 51
 52#ifdef CONFIG_NF_CONNTRACK_EVENTS
 53
 54/* This structure is passed to event handler */
 55struct nf_ct_event {
 56	struct nf_conn *ct;
 57	u32 portid;
 58	int report;
 59};
 60
 61struct nf_exp_event {
 62	struct nf_conntrack_expect *exp;
 63	u32 portid;
 64	int report;
 65};
 66
 67struct nf_ct_event_notifier {
 68	int (*ct_event)(unsigned int events, const struct nf_ct_event *item);
 69	int (*exp_event)(unsigned int events, const struct nf_exp_event *item);
 70};
 71
 72void nf_conntrack_register_notifier(struct net *net,
 73				   const struct nf_ct_event_notifier *nb);
 74void nf_conntrack_unregister_notifier(struct net *net);
 75
 76void nf_ct_deliver_cached_events(struct nf_conn *ct);
 77int nf_conntrack_eventmask_report(unsigned int eventmask, struct nf_conn *ct,
 78				  u32 portid, int report);
 79
 80bool nf_ct_ecache_ext_add(struct nf_conn *ct, u16 ctmask, u16 expmask, gfp_t gfp);
 81#else
 82
 83static inline void nf_ct_deliver_cached_events(const struct nf_conn *ct)
 84{
 85}
 86
 87static inline int nf_conntrack_eventmask_report(unsigned int eventmask,
 88						struct nf_conn *ct,
 89						u32 portid,
 90						int report)
 91{
 92	return 0;
 93}
 94
 95static inline bool nf_ct_ecache_ext_add(struct nf_conn *ct, u16 ctmask, u16 expmask, gfp_t gfp)
 96{
 97	return false;
 98}
 99#endif
100
101static inline void
102nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct)
103{
104#ifdef CONFIG_NF_CONNTRACK_EVENTS
105	struct net *net = nf_ct_net(ct);
106	struct nf_conntrack_ecache *e;
107
108	if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb))
109		return;
110
111	e = nf_ct_ecache_find(ct);
112	if (e == NULL)
113		return;
114
115#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
116	/* renew only if this is the first cached event, so that the
117	 * timestamp reflects the first, not the last, generated event.
118	 */
119	if (local64_read(&e->timestamp) && READ_ONCE(e->cache) == 0)
120		local64_set(&e->timestamp, ktime_get_real_ns());
121#endif
122
123	set_bit(event, &e->cache);
124#endif
125}
126
127static inline int
128nf_conntrack_event_report(enum ip_conntrack_events event, struct nf_conn *ct,
129			  u32 portid, int report)
130{
131#ifdef CONFIG_NF_CONNTRACK_EVENTS
132	if (nf_ct_ecache_exist(ct))
133		return nf_conntrack_eventmask_report(1 << event, ct, portid, report);
134#endif
135	return 0;
136}
137
138static inline int
139nf_conntrack_event(enum ip_conntrack_events event, struct nf_conn *ct)
140{
141#ifdef CONFIG_NF_CONNTRACK_EVENTS
142	if (nf_ct_ecache_exist(ct))
143		return nf_conntrack_eventmask_report(1 << event, ct, 0, 0);
144#endif
145	return 0;
146}
147
148#ifdef CONFIG_NF_CONNTRACK_EVENTS
149void nf_ct_expect_event_report(enum ip_conntrack_expect_events event,
150			       struct nf_conntrack_expect *exp,
151			       u32 portid, int report);
152
153void nf_conntrack_ecache_work(struct net *net, enum nf_ct_ecache_state state);
154
155void nf_conntrack_ecache_pernet_init(struct net *net);
156void nf_conntrack_ecache_pernet_fini(struct net *net);
157
158struct nf_conntrack_net_ecache *nf_conn_pernet_ecache(const struct net *net);
159
160static inline bool nf_conntrack_ecache_dwork_pending(const struct net *net)
161{
162	return net->ct.ecache_dwork_pending;
163}
164#else /* CONFIG_NF_CONNTRACK_EVENTS */
165
166static inline void nf_ct_expect_event_report(enum ip_conntrack_expect_events e,
167					     struct nf_conntrack_expect *exp,
168					     u32 portid,
169					     int report)
170{
171}
172
173static inline void nf_conntrack_ecache_work(struct net *net,
174					    enum nf_ct_ecache_state s)
175{
176}
177
178static inline void nf_conntrack_ecache_pernet_init(struct net *net)
179{
180}
181
182static inline void nf_conntrack_ecache_pernet_fini(struct net *net)
183{
184}
185static inline bool nf_conntrack_ecache_dwork_pending(const struct net *net) { return false; }
186#endif /* CONFIG_NF_CONNTRACK_EVENTS */
187#endif /*_NF_CONNTRACK_ECACHE_H*/