include/net/netfilter/nf_conntrack_expect.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * connection tracking expectations.
   4  */
   5
   6 #ifndef _NF_CONNTRACK_EXPECT_H
   7 #define _NF_CONNTRACK_EXPECT_H
   8
   9 #include <linux/refcount.h>
  10
  11 #include <net/netfilter/nf_conntrack.h>
  12 #include <net/netfilter/nf_conntrack_zones.h>
  13
  14 extern unsigned int nf_ct_expect_hsize;
  15 extern unsigned int nf_ct_expect_max;
  16 extern struct hlist_head *nf_ct_expect_hash;
  17
  18 struct nf_conntrack_expect {
  19         /* Conntrack expectation list member */
  20         struct hlist_node lnode;
  21
  22         /* Hash member */
  23         struct hlist_node hnode;
  24
  25         /* We expect this tuple, with the following mask */
  26         struct nf_conntrack_tuple tuple;
  27         struct nf_conntrack_tuple_mask mask;
  28
  29         /* Function to call after setup and insertion */
  30         void (*expectfn)(struct nf_conn *new,
  31                          struct nf_conntrack_expect *this);
  32
  33         /* Helper to assign to new connection */
  34         struct nf_conntrack_helper *helper;
  35
  36         /* The conntrack of the master connection */
  37         struct nf_conn *master;
  38
  39         /* Timer function; deletes the expectation. */
  40         struct timer_list timeout;
  41
  42         /* Usage count. */
  43         refcount_t use;
  44
  45         /* Flags */
  46         unsigned int flags;
  47
  48         /* Expectation class */
  49         unsigned int class;
  50
  51 #if IS_ENABLED(CONFIG_NF_NAT)
  52         union nf_inet_addr saved_addr;
  53         /* This is the original per-proto part, used to map the
  54          * expected connection the way the recipient expects. */
  55         union nf_conntrack_man_proto saved_proto;
  56         /* Direction relative to the master connection. */
  57         enum ip_conntrack_dir dir;
  58 #endif
  59
  60         struct rcu_head rcu;
  61 };
  62
  63 static inline struct net *nf_ct_exp_net(struct nf_conntrack_expect *exp)
  64 {
  65         return nf_ct_net(exp->master);
  66 }
  67
  68 #define NF_CT_EXP_POLICY_NAME_LEN       16
  69
  70 struct nf_conntrack_expect_policy {
  71         unsigned int    max_expected;
  72         unsigned int    timeout;
  73         char            name[NF_CT_EXP_POLICY_NAME_LEN];
  74 };
  75
  76 #define NF_CT_EXPECT_CLASS_DEFAULT      0
  77 #define NF_CT_EXPECT_MAX_CNT            255
  78
  79 /* Allow to reuse expectations with the same tuples from different master
  80  * conntracks.
  81  */
  82 #define NF_CT_EXP_F_SKIP_MASTER 0x1
  83
  84 int nf_conntrack_expect_pernet_init(struct net *net);
  85 void nf_conntrack_expect_pernet_fini(struct net *net);
  86
  87 int nf_conntrack_expect_init(void);
  88 void nf_conntrack_expect_fini(void);
  89
  90 struct nf_conntrack_expect *
  91 __nf_ct_expect_find(struct net *net,
  92                     const struct nf_conntrack_zone *zone,
  93                     const struct nf_conntrack_tuple *tuple);
  94
  95 struct nf_conntrack_expect *
  96 nf_ct_expect_find_get(struct net *net,
  97                       const struct nf_conntrack_zone *zone,
  98                       const struct nf_conntrack_tuple *tuple);
  99
 100 struct nf_conntrack_expect *
 101 nf_ct_find_expectation(struct net *net,
 102                        const struct nf_conntrack_zone *zone,
 103                        const struct nf_conntrack_tuple *tuple);
 104
 105 void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
 106                                 u32 portid, int report);
 107 static inline void nf_ct_unlink_expect(struct nf_conntrack_expect *exp)
 108 {
 109         nf_ct_unlink_expect_report(exp, 0, 0);
 110 }
 111
 112 void nf_ct_remove_expectations(struct nf_conn *ct);
 113 void nf_ct_unexpect_related(struct nf_conntrack_expect *exp);
 114 bool nf_ct_remove_expect(struct nf_conntrack_expect *exp);
 115
 116 void nf_ct_expect_iterate_destroy(bool (*iter)(struct nf_conntrack_expect *e, void *data), void *data);
 117 void nf_ct_expect_iterate_net(struct net *net,
 118                               bool (*iter)(struct nf_conntrack_expect *e, void *data),
 119                               void *data, u32 portid, int report);
 120
 121 /* Allocate space for an expectation: this is mandatory before calling
 122    nf_ct_expect_related.  You will have to call put afterwards. */
 123 struct nf_conntrack_expect *nf_ct_expect_alloc(struct nf_conn *me);
 124 void nf_ct_expect_init(struct nf_conntrack_expect *, unsigned int, u_int8_t,
 125                        const union nf_inet_addr *,
 126                        const union nf_inet_addr *,
 127                        u_int8_t, const __be16 *, const __be16 *);
 128 void nf_ct_expect_put(struct nf_conntrack_expect *exp);
 129 int nf_ct_expect_related_report(struct nf_conntrack_expect *expect,
 130                                 u32 portid, int report, unsigned int flags);
 131 static inline int nf_ct_expect_related(struct nf_conntrack_expect *expect,
 132                                        unsigned int flags)
 133 {
 134         return nf_ct_expect_related_report(expect, 0, 0, flags);
 135 }
 136
 137 #endif /*_NF_CONNTRACK_EXPECT_H*/
 138