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, id: 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, id: 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(nr: event, addr: &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(eventmask: 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(eventmask: 1 << event, ct, portid: 0, report: 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*/
188

source code of linux/include/net/netfilter/nf_conntrack_ecache.h