LXR linux/include/net/netfilter/nf_conntrack

   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
  17struct seq_file;
  18
  19struct 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 */
 119extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 120
 121#define MAX_NF_CT_PROTO 256
 122
 123struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u_int16_t l3proto,
 124                                                  u_int8_t l4proto);
 125
 126struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u_int16_t l3proto,
 127                                                    u_int8_t l4proto);
 128void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 129
 130/* Protocol pernet registration. */
 131int nf_ct_l4proto_pernet_register_one(struct net *net,
 132                                      struct nf_conntrack_l4proto *proto);
 133void nf_ct_l4proto_pernet_unregister_one(struct net *net,
 134                                         struct nf_conntrack_l4proto *proto);
 135int nf_ct_l4proto_pernet_register(struct net *net,
 136                                  struct nf_conntrack_l4proto *proto[],
 137                                  unsigned int num_proto);
 138void nf_ct_l4proto_pernet_unregister(struct net *net,
 139                                     struct nf_conntrack_l4proto *proto[],
 140                                     unsigned int num_proto);
 141
 142/* Protocol global registration. */
 143int nf_ct_l4proto_register_one(struct nf_conntrack_l4proto *proto);
 144void nf_ct_l4proto_unregister_one(struct nf_conntrack_l4proto *proto);
 145int nf_ct_l4proto_register(struct nf_conntrack_l4proto *proto[],
 146                           unsigned int num_proto);
 147void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *proto[],
 148                              unsigned int num_proto);
 149
 150/* Generic netlink helpers */
 151int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 152                               const struct nf_conntrack_tuple *tuple);
 153int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 154                               struct nf_conntrack_tuple *t);
 155int nf_ct_port_nlattr_tuple_size(void);
 156extern 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
 163static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
 164#endif /* CONFIG_SYSCTL */
 165
 166#endif /*_NF_CONNTRACK_PROTOCOL_H*/
 167