include/net/netfilter/nf_conntrack_l4proto.h

   1 /*
   2  * Header for use in defining a given L4 protocol for connection tracking.
   3  *
   4  * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   5  *      - generalized L3 protocol dependent part.
   6  *
   7  * Derived from include/linux/netfiter_ipv4/ip_conntrack_protcol.h
   8  */
   9
  10 #ifndef _NF_CONNTRACK_L4PROTO_H
  11 #define _NF_CONNTRACK_L4PROTO_H
  12 #include <linux/netlink.h>
  13 #include <net/netlink.h>
  14 #include <net/netfilter/nf_conntrack.h>
  15 #include <net/netns/generic.h>
  16
  17 struct seq_file;
  18
  19 struct nf_conntrack_l4proto {
  20         /* L3 Protocol number. */
  21         u_int16_t l3proto;
  22
  23         /* L4 Protocol number. */
  24         u_int8_t l4proto;
  25
  26         /* Resolve clashes on insertion races. */
  27         bool allow_clash;
  28
  29         /* Try to fill in the third arg: dataoff is offset past network protocol
  30            hdr.  Return true if possible. */
  31         bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
  32                              struct net *net, struct nf_conntrack_tuple *tuple);
  33
  34         /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  35          * Some packets can't be inverted: return 0 in that case.
  36          */
  37         bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  38                              const struct nf_conntrack_tuple *orig);
  39
  40         /* Returns verdict for packet, or -1 for invalid. */
  41         int (*packet)(struct nf_conn *ct,
  42                       const struct sk_buff *skb,
  43                       unsigned int dataoff,
  44                       enum ip_conntrack_info ctinfo,
  45                       u_int8_t pf,
  46                       unsigned int hooknum,
  47                       unsigned int *timeouts);
  48
  49         /* Called when a new connection for this protocol found;
  50          * returns TRUE if it's OK.  If so, packet() called next. */
  51         bool (*new)(struct nf_conn *ct, const struct sk_buff *skb,
  52                     unsigned int dataoff, unsigned int *timeouts);
  53
  54         /* Called when a conntrack entry is destroyed */
  55         void (*destroy)(struct nf_conn *ct);
  56
  57         int (*error)(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
  58                      unsigned int dataoff,
  59                      u_int8_t pf, unsigned int hooknum);
  60
  61         /* called by gc worker if table is full */
  62         bool (*can_early_drop)(const struct nf_conn *ct);
  63
  64         /* Print out the per-protocol part of the tuple. Return like seq_* */
  65         void (*print_tuple)(struct seq_file *s,
  66                             const struct nf_conntrack_tuple *);
  67
  68         /* Print out the private part of the conntrack. */
  69         void (*print_conntrack)(struct seq_file *s, struct nf_conn *);
  70
  71         /* Return the array of timeouts for this protocol. */
  72         unsigned int *(*get_timeouts)(struct net *net);
  73
  74         /* convert protoinfo to nfnetink attributes */
  75         int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
  76                          struct nf_conn *ct);
  77         /* Calculate protoinfo nlattr size */
  78         int (*nlattr_size)(void);
  79
  80         /* convert nfnetlink attributes to protoinfo */
  81         int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
  82
  83         int (*tuple_to_nlattr)(struct sk_buff *skb,
  84                                const struct nf_conntrack_tuple *t);
  85         /* Calculate tuple nlattr size */
  86         int (*nlattr_tuple_size)(void);
  87         int (*nlattr_to_tuple)(struct nlattr *tb[],
  88                                struct nf_conntrack_tuple *t);
  89         const struct nla_policy *nla_policy;
  90
  91         size_t nla_size;
  92
  93 #if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
  94         struct {
  95                 size_t obj_size;
  96                 int (*nlattr_to_obj)(struct nlattr *tb[],
  97                                      struct net *net, void *data);
  98                 int (*obj_to_nlattr)(struct sk_buff *skb, const void *data);
  99
 100                 unsigned int nlattr_max;
 101                 const struct nla_policy *nla_policy;
 102         } ctnl_timeout;
 103 #endif
 104         unsigned int    *net_id;
 105         /* Init l4proto pernet data */
 106         int (*init_net)(struct net *net, u_int16_t proto);
 107
 108         /* Return the per-net protocol part. */
 109         struct nf_proto_net *(*get_net_proto)(struct net *net);
 110
 111         /* Protocol name */
 112         const char *name;
 113
 114         /* Module (if any) which this is connected to. */
 115         struct module *me;
 116 };
 117
 118 /* Existing built-in generic protocol */
 119 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 120
 121 #define MAX_NF_CT_PROTO 256
 122
 123 struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u_int16_t l3proto,
 124                                                   u_int8_t l4proto);
 125
 126 struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u_int16_t l3proto,
 127                                                     u_int8_t l4proto);
 128 void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 129
 130 /* Protocol pernet registration. */
 131 int nf_ct_l4proto_pernet_register_one(struct net *net,
 132                                       struct nf_conntrack_l4proto *proto);
 133 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
 134                                          struct nf_conntrack_l4proto *proto);
 135 int nf_ct_l4proto_pernet_register(struct net *net,
 136                                   struct nf_conntrack_l4proto *proto[],
 137                                   unsigned int num_proto);
 138 void nf_ct_l4proto_pernet_unregister(struct net *net,
 139                                      struct nf_conntrack_l4proto *proto[],
 140                                      unsigned int num_proto);
 141
 142 /* Protocol global registration. */
 143 int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *proto);
 144 void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *proto);
 145 int nf_ct_l4proto_register(struct nf_conntrack_l4proto *proto[],
 146                            unsigned int num_proto);
 147 void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *proto[],
 148                               unsigned int num_proto);
 149
 150 /* Generic netlink helpers */
 151 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 152                                const struct nf_conntrack_tuple *tuple);
 153 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 154                                struct nf_conntrack_tuple *t);
 155 int nf_ct_port_nlattr_tuple_size(void);
 156 extern const struct nla_policy nf_ct_port_nla_policy[];
 157
 158 #ifdef CONFIG_SYSCTL
 159 #define LOG_INVALID(net, proto)                         \
 160         ((net)->ct.sysctl_log_invalid == (proto) ||     \
 161          (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
 162 #else
 163 static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
 164 #endif /* CONFIG_SYSCTL */
 165
 166 #endif /*_NF_CONNTRACK_PROTOCOL_H*/