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
17 enum 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
22 struct 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
33 static inline struct nf_conntrack_ecache *
nf_ct_ecache_find(const struct nf_conn * ct)34 nf_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
nf_ct_ecache_exist(const struct nf_conn * ct)43 static 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 */
55 struct nf_ct_event {
56 struct nf_conn *ct;
57 u32 portid;
58 int report;
59 };
60
61 struct nf_exp_event {
62 struct nf_conntrack_expect *exp;
63 u32 portid;
64 int report;
65 };
66
67 struct 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
72 void nf_conntrack_register_notifier(struct net *net,
73 const struct nf_ct_event_notifier *nb);
74 void nf_conntrack_unregister_notifier(struct net *net);
75
76 void nf_ct_deliver_cached_events(struct nf_conn *ct);
77 int nf_conntrack_eventmask_report(unsigned int eventmask, struct nf_conn *ct,
78 u32 portid, int report);
79
80 bool nf_ct_ecache_ext_add(struct nf_conn *ct, u16 ctmask, u16 expmask, gfp_t gfp);
81 #else
82
nf_ct_deliver_cached_events(const struct nf_conn * ct)83 static inline void nf_ct_deliver_cached_events(const struct nf_conn *ct)
84 {
85 }
86
nf_conntrack_eventmask_report(unsigned int eventmask,struct nf_conn * ct,u32 portid,int report)87 static 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
nf_ct_ecache_ext_add(struct nf_conn * ct,u16 ctmask,u16 expmask,gfp_t gfp)95 static 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
101 static inline void
nf_conntrack_event_cache(enum ip_conntrack_events event,struct nf_conn * ct)102 nf_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
127 static inline int
nf_conntrack_event_report(enum ip_conntrack_events event,struct nf_conn * ct,u32 portid,int report)128 nf_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
138 static inline int
nf_conntrack_event(enum ip_conntrack_events event,struct nf_conn * ct)139 nf_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
149 void nf_ct_expect_event_report(enum ip_conntrack_expect_events event,
150 struct nf_conntrack_expect *exp,
151 u32 portid, int report);
152
153 void nf_conntrack_ecache_work(struct net *net, enum nf_ct_ecache_state state);
154
155 void nf_conntrack_ecache_pernet_init(struct net *net);
156 void nf_conntrack_ecache_pernet_fini(struct net *net);
157
158 struct nf_conntrack_net_ecache *nf_conn_pernet_ecache(const struct net *net);
159
nf_conntrack_ecache_dwork_pending(const struct net * net)160 static 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
nf_ct_expect_event_report(enum ip_conntrack_expect_events e,struct nf_conntrack_expect * exp,u32 portid,int report)166 static 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
nf_conntrack_ecache_work(struct net * net,enum nf_ct_ecache_state s)173 static inline void nf_conntrack_ecache_work(struct net *net,
174 enum nf_ct_ecache_state s)
175 {
176 }
177
nf_conntrack_ecache_pernet_init(struct net * net)178 static inline void nf_conntrack_ecache_pernet_init(struct net *net)
179 {
180 }
181
nf_conntrack_ecache_pernet_fini(struct net * net)182 static inline void nf_conntrack_ecache_pernet_fini(struct net *net)
183 {
184 }
nf_conntrack_ecache_dwork_pending(const struct net * net)185 static 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