include/net/netfilter/nf_conntrack_ecache.h

   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 /* Connection tracking event types */
  16 enum ip_conntrack_events
  17 {
  18         IPCT_NEW                = 0,    /* new conntrack */
  19         IPCT_RELATED            = 1,    /* related conntrack */
  20         IPCT_DESTROY            = 2,    /* destroyed conntrack */
  21         IPCT_STATUS             = 3,    /* status has changed */
  22         IPCT_PROTOINFO          = 4,    /* protocol information has changed */
  23         IPCT_HELPER             = 5,    /* new helper has been set */
  24         IPCT_MARK               = 6,    /* new mark has been set */
  25         IPCT_NATSEQADJ          = 7,    /* NAT is doing sequence adjustment */
  26         IPCT_SECMARK            = 8,    /* new security mark has been set */
  27 };
  28
  29 enum ip_conntrack_expect_events {
  30         IPEXP_NEW               = 0,    /* new expectation */
  31 };
  32
  33 struct nf_conntrack_ecache {
  34         unsigned long cache;            /* bitops want long */
  35         unsigned long missed;           /* missed events */
  36         u32 pid;                        /* netlink pid of destroyer */
  37 };
  38
  39 static inline struct nf_conntrack_ecache *
  40 nf_ct_ecache_find(const struct nf_conn *ct)
  41 {
  42         return nf_ct_ext_find(ct, NF_CT_EXT_ECACHE);
  43 }
  44
  45 static inline struct nf_conntrack_ecache *
  46 nf_ct_ecache_ext_add(struct nf_conn *ct, gfp_t gfp)
  47 {
  48         struct net *net = nf_ct_net(ct);
  49
  50         if (!net->ct.sysctl_events)
  51                 return NULL;
  52
  53         return nf_ct_ext_add(ct, NF_CT_EXT_ECACHE, gfp);
  54 };
  55
  56 #ifdef CONFIG_NF_CONNTRACK_EVENTS
  57 /* This structure is passed to event handler */
  58 struct nf_ct_event {
  59         struct nf_conn *ct;
  60         u32 pid;
  61         int report;
  62 };
  63
  64 struct nf_ct_event_notifier {
  65         int (*fcn)(unsigned int events, struct nf_ct_event *item);
  66 };
  67
  68 extern struct nf_ct_event_notifier *nf_conntrack_event_cb;
  69 extern int nf_conntrack_register_notifier(struct nf_ct_event_notifier *nb);
  70 extern void nf_conntrack_unregister_notifier(struct nf_ct_event_notifier *nb);
  71
  72 extern void nf_ct_deliver_cached_events(struct nf_conn *ct);
  73
  74 static inline void
  75 nf_conntrack_event_cache(enum ip_conntrack_events event, struct nf_conn *ct)
  76 {
  77         struct nf_conntrack_ecache *e;
  78
  79         if (nf_conntrack_event_cb == NULL)
  80                 return;
  81
  82         e = nf_ct_ecache_find(ct);
  83         if (e == NULL)
  84                 return;
  85
  86         set_bit(event, &e->cache);
  87 }
  88
  89 static inline int
  90 nf_conntrack_eventmask_report(unsigned int eventmask,
  91                               struct nf_conn *ct,
  92                               u32 pid,
  93                               int report)
  94 {
  95         int ret = 0;
  96         struct net *net = nf_ct_net(ct);
  97         struct nf_ct_event_notifier *notify;
  98         struct nf_conntrack_ecache *e;
  99
 100         rcu_read_lock();
 101         notify = rcu_dereference(nf_conntrack_event_cb);
 102         if (notify == NULL)
 103                 goto out_unlock;
 104
 105         if (!net->ct.sysctl_events)
 106                 goto out_unlock;
 107
 108         e = nf_ct_ecache_find(ct);
 109         if (e == NULL)
 110                 goto out_unlock;
 111
 112         if (nf_ct_is_confirmed(ct) && !nf_ct_is_dying(ct)) {
 113                 struct nf_ct_event item = {
 114                         .ct     = ct,
 115                         .pid    = e->pid ? e->pid : pid,
 116                         .report = report
 117                 };
 118                 /* This is a resent of a destroy event? If so, skip missed */
 119                 unsigned long missed = e->pid ? 0 : e->missed;
 120
 121                 ret = notify->fcn(eventmask | missed, &item);
 122                 if (unlikely(ret < 0 || missed)) {
 123                         spin_lock_bh(&ct->lock);
 124                         if (ret < 0) {
 125                                 /* This is a destroy event that has been
 126                                  * triggered by a process, we store the PID
 127                                  * to include it in the retransmission. */
 128                                 if (eventmask & (1 << IPCT_DESTROY) &&
 129                                     e->pid == 0 && pid != 0)
 130                                         e->pid = pid;
 131                                 else
 132                                         e->missed |= eventmask;
 133                         } else
 134                                 e->missed &= ~missed;
 135                         spin_unlock_bh(&ct->lock);
 136                 }
 137         }
 138 out_unlock:
 139         rcu_read_unlock();
 140         return ret;
 141 }
 142
 143 static inline int
 144 nf_conntrack_event_report(enum ip_conntrack_events event, struct nf_conn *ct,
 145                           u32 pid, int report)
 146 {
 147         return nf_conntrack_eventmask_report(1 << event, ct, pid, report);
 148 }
 149
 150 static inline int
 151 nf_conntrack_event(enum ip_conntrack_events event, struct nf_conn *ct)
 152 {
 153         return nf_conntrack_eventmask_report(1 << event, ct, 0, 0);
 154 }
 155
 156 struct nf_exp_event {
 157         struct nf_conntrack_expect *exp;
 158         u32 pid;
 159         int report;
 160 };
 161
 162 struct nf_exp_event_notifier {
 163         int (*fcn)(unsigned int events, struct nf_exp_event *item);
 164 };
 165
 166 extern struct nf_exp_event_notifier *nf_expect_event_cb;
 167 extern int nf_ct_expect_register_notifier(struct nf_exp_event_notifier *nb);
 168 extern void nf_ct_expect_unregister_notifier(struct nf_exp_event_notifier *nb);
 169
 170 static inline void
 171 nf_ct_expect_event_report(enum ip_conntrack_expect_events event,
 172                           struct nf_conntrack_expect *exp,
 173                           u32 pid,
 174                           int report)
 175 {
 176         struct net *net = nf_ct_exp_net(exp);
 177         struct nf_exp_event_notifier *notify;
 178
 179         rcu_read_lock();
 180         notify = rcu_dereference(nf_expect_event_cb);
 181         if (notify == NULL)
 182                 goto out_unlock;
 183
 184         if (!net->ct.sysctl_events)
 185                 goto out_unlock;
 186
 187         {
 188                 struct nf_exp_event item = {
 189                         .exp    = exp,
 190                         .pid    = pid,
 191                         .report = report
 192                 };
 193                 notify->fcn(1 << event, &item);
 194         }
 195 out_unlock:
 196         rcu_read_unlock();
 197 }
 198
 199 static inline void
 200 nf_ct_expect_event(enum ip_conntrack_expect_events event,
 201                    struct nf_conntrack_expect *exp)
 202 {
 203         nf_ct_expect_event_report(event, exp, 0, 0);
 204 }
 205
 206 extern int nf_conntrack_ecache_init(struct net *net);
 207 extern void nf_conntrack_ecache_fini(struct net *net);
 208
 209 #else /* CONFIG_NF_CONNTRACK_EVENTS */
 210
 211 static inline void nf_conntrack_event_cache(enum ip_conntrack_events event,
 212                                             struct nf_conn *ct) {}
 213 static inline int nf_conntrack_eventmask_report(unsigned int eventmask,
 214                                                 struct nf_conn *ct,
 215                                                 u32 pid,
 216                                                 int report) { return 0; }
 217 static inline int nf_conntrack_event(enum ip_conntrack_events event,
 218                                      struct nf_conn *ct) { return 0; }
 219 static inline int nf_conntrack_event_report(enum ip_conntrack_events event,
 220                                             struct nf_conn *ct,
 221                                             u32 pid,
 222                                             int report) { return 0; }
 223 static inline void nf_ct_deliver_cached_events(const struct nf_conn *ct) {}
 224 static inline void nf_ct_expect_event(enum ip_conntrack_expect_events event,
 225                                       struct nf_conntrack_expect *exp) {}
 226 static inline void nf_ct_expect_event_report(enum ip_conntrack_expect_events e,
 227                                              struct nf_conntrack_expect *exp,
 228                                              u32 pid,
 229                                              int report) {}
 230
 231 static inline int nf_conntrack_ecache_init(struct net *net)
 232 {
 233         return 0;
 234 }
 235
 236 static inline void nf_conntrack_ecache_fini(struct net *net)
 237 {
 238 }
 239 #endif /* CONFIG_NF_CONNTRACK_EVENTS */
 240
 241 #endif /*_NF_CONNTRACK_ECACHE_H*/
 242