1 /*
2  * connection tracking event cache.
3  */
4 
5 #ifndef _NF_CONNTRACK_ECACHE_H
6 #define _NF_CONNTRACK_ECACHE_H
7 #include <net/netfilter/nf_conntrack.h>
8 
9 #include <net/net_namespace.h>
10 #include <net/netfilter/nf_conntrack_expect.h>
11 #include <linux/netfilter/nf_conntrack_common.h>
12 #include <linux/netfilter/nf_conntrack_tuple_common.h>
13 #include <net/netfilter/nf_conntrack_extend.h>
14 
15 struct nf_conntrack_ecache {
16 	unsigned long cache;	/* bitops want long */
17 	unsigned long missed;	/* missed events */
18 	u16 ctmask;		/* bitmask of ct events to be delivered */
19 	u16 expmask;		/* bitmask of expect events to be delivered */
20 	u32 portid;		/* netlink portid of destroyer */
21 };
22 
23 static inline struct nf_conntrack_ecache *
24 nf_ct_ecache_find(const struct nf_conn *ct)
25 {
26 #ifdef CONFIG_NF_CONNTRACK_EVENTS
27 	return nf_ct_ext_find(ct, NF_CT_EXT_ECACHE);
28 #else
29 	return NULL;
30 #endif
31 }
32 
33 static inline struct nf_conntrack_ecache *
34 nf_ct_ecache_ext_add(struct nf_conn *ct, u16 ctmask, u16 expmask, gfp_t gfp)
35 {
36 #ifdef CONFIG_NF_CONNTRACK_EVENTS
37 	struct net *net = nf_ct_net(ct);
38 	struct nf_conntrack_ecache *e;
39 
40 	if (!ctmask && !expmask && net->ct.sysctl_events) {
41 		ctmask = ~0;
42 		expmask = ~0;
43 	}
44 	if (!ctmask && !expmask)
45 		return NULL;
46 
47 	e = nf_ct_ext_add(ct, NF_CT_EXT_ECACHE, gfp);
48 	if (e) {
49 		e->ctmask  = ctmask;
50 		e->expmask = expmask;
51 	}
52 	return e;
53 #else
54 	return NULL;
55 #endif
56 };
57 
58 #ifdef CONFIG_NF_CONNTRACK_EVENTS
59 /* This structure is passed to event handler */
60 struct nf_ct_event {
61 	struct nf_conn *ct;
62 	u32 portid;
63 	int report;
64 };
65 
66 struct nf_ct_event_notifier {
67 	int (*fcn)(unsigned int events, struct nf_ct_event *item);
68 };
69 
70 int nf_conntrack_register_notifier(struct net *net,
71 				   struct nf_ct_event_notifier *nb);
72 void nf_conntrack_unregister_notifier(struct net *net,
73 				      struct nf_ct_event_notifier *nb);
74 
75 void nf_ct_deliver_cached_events(struct nf_conn *ct);
76 int nf_conntrack_eventmask_report(unsigned int eventmask, struct nf_conn *ct,
77 				  u32 portid, int report);
78 
79 static inline void
80 nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct)
81 {
82 	struct net *net = nf_ct_net(ct);
83 	struct nf_conntrack_ecache *e;
84 
85 	if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb))
86 		return;
87 
88 	e = nf_ct_ecache_find(ct);
89 	if (e == NULL)
90 		return;
91 
92 	set_bit(event, &e->cache);
93 }
94 
95 static inline int
96 nf_conntrack_event_report(enum ip_conntrack_events event, struct nf_conn *ct,
97 			  u32 portid, int report)
98 {
99 	const struct net *net = nf_ct_net(ct);
100 
101 	if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb))
102 		return 0;
103 
104 	return nf_conntrack_eventmask_report(1 << event, ct, portid, report);
105 }
106 
107 static inline int
108 nf_conntrack_event(enum ip_conntrack_events event, struct nf_conn *ct)
109 {
110 	const struct net *net = nf_ct_net(ct);
111 
112 	if (!rcu_access_pointer(net->ct.nf_conntrack_event_cb))
113 		return 0;
114 
115 	return nf_conntrack_eventmask_report(1 << event, ct, 0, 0);
116 }
117 
118 struct nf_exp_event {
119 	struct nf_conntrack_expect *exp;
120 	u32 portid;
121 	int report;
122 };
123 
124 struct nf_exp_event_notifier {
125 	int (*fcn)(unsigned int events, struct nf_exp_event *item);
126 };
127 
128 int nf_ct_expect_register_notifier(struct net *net,
129 				   struct nf_exp_event_notifier *nb);
130 void nf_ct_expect_unregister_notifier(struct net *net,
131 				      struct nf_exp_event_notifier *nb);
132 
133 void nf_ct_expect_event_report(enum ip_conntrack_expect_events event,
134 			       struct nf_conntrack_expect *exp,
135 			       u32 portid, int report);
136 
137 int nf_conntrack_ecache_pernet_init(struct net *net);
138 void nf_conntrack_ecache_pernet_fini(struct net *net);
139 
140 int nf_conntrack_ecache_init(void);
141 void nf_conntrack_ecache_fini(void);
142 
143 static inline void nf_conntrack_ecache_delayed_work(struct net *net)
144 {
145 	if (!delayed_work_pending(&net->ct.ecache_dwork)) {
146 		schedule_delayed_work(&net->ct.ecache_dwork, HZ);
147 		net->ct.ecache_dwork_pending = true;
148 	}
149 }
150 
151 static inline void nf_conntrack_ecache_work(struct net *net)
152 {
153 	if (net->ct.ecache_dwork_pending) {
154 		net->ct.ecache_dwork_pending = false;
155 		mod_delayed_work(system_wq, &net->ct.ecache_dwork, 0);
156 	}
157 }
158 #else /* CONFIG_NF_CONNTRACK_EVENTS */
159 static inline void nf_conntrack_event_cache(enum ip_conntrack_events event,
160 					    struct nf_conn *ct) {}
161 static inline int nf_conntrack_eventmask_report(unsigned int eventmask,
162 						struct nf_conn *ct,
163 						u32 portid,
164 						int report) { return 0; }
165 static inline int nf_conntrack_event(enum ip_conntrack_events event,
166 				     struct nf_conn *ct) { return 0; }
167 static inline int nf_conntrack_event_report(enum ip_conntrack_events event,
168 					    struct nf_conn *ct,
169 					    u32 portid,
170 					    int report) { return 0; }
171 static inline void nf_ct_deliver_cached_events(const struct nf_conn *ct) {}
172 static inline void nf_ct_expect_event_report(enum ip_conntrack_expect_events e,
173 					     struct nf_conntrack_expect *exp,
174  					     u32 portid,
175  					     int report) {}
176 
177 static inline int nf_conntrack_ecache_pernet_init(struct net *net)
178 {
179 	return 0;
180 }
181 
182 static inline void nf_conntrack_ecache_pernet_fini(struct net *net)
183 {
184 }
185 
186 static inline int nf_conntrack_ecache_init(void)
187 {
188 	return 0;
189 }
190 
191 static inline void nf_conntrack_ecache_fini(void)
192 {
193 }
194 
195 static inline void nf_conntrack_ecache_delayed_work(struct net *net)
196 {
197 }
198 
199 static inline void nf_conntrack_ecache_work(struct net *net)
200 {
201 }
202 #endif /* CONFIG_NF_CONNTRACK_EVENTS */
203 
204 #endif /*_NF_CONNTRACK_ECACHE_H*/
205 
206