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, enum ip_conntrack_info *ctinfo,
  59                     u_int8_t pf, unsigned int hooknum);
  60
  61        /* Print out the per-protocol part of the tuple. Return like seq_* */
  62        void (*print_tuple)(struct seq_file *s,
  63                            const struct nf_conntrack_tuple *);
  64
  65        /* Print out the private part of the conntrack. */
  66        void (*print_conntrack)(struct seq_file *s, struct nf_conn *);
  67
  68        /* Return the array of timeouts for this protocol. */
  69        unsigned int *(*get_timeouts)(struct net *net);
  70
  71        /* convert protoinfo to nfnetink attributes */
  72        int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
  73                         struct nf_conn *ct);
  74        /* Calculate protoinfo nlattr size */
  75        int (*nlattr_size)(void);
  76
  77        /* convert nfnetlink attributes to protoinfo */
  78        int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
  79
  80        int (*tuple_to_nlattr)(struct sk_buff *skb,
  81                               const struct nf_conntrack_tuple *t);
  82        /* Calculate tuple nlattr size */
  83        int (*nlattr_tuple_size)(void);
  84        int (*nlattr_to_tuple)(struct nlattr *tb[],
  85                               struct nf_conntrack_tuple *t);
  86        const struct nla_policy *nla_policy;
  87
  88        size_t nla_size;
  89
  90#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
  91        struct {
  92                size_t obj_size;
  93                int (*nlattr_to_obj)(struct nlattr *tb[],
  94                                     struct net *net, void *data);
  95                int (*obj_to_nlattr)(struct sk_buff *skb, const void *data);
  96
  97                unsigned int nlattr_max;
  98                const struct nla_policy *nla_policy;
  99        } ctnl_timeout;
 100#endif
 101        int     *net_id;
 102        /* Init l4proto pernet data */
 103        int (*init_net)(struct net *net, u_int16_t proto);
 104
 105        /* Return the per-net protocol part. */
 106        struct nf_proto_net *(*get_net_proto)(struct net *net);
 107
 108        /* Protocol name */
 109        const char *name;
 110
 111        /* Module (if any) which this is connected to. */
 112        struct module *me;
 113};
 114
 115/* Existing built-in generic protocol */
 116extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 117
 118#define MAX_NF_CT_PROTO 256
 119
 120struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u_int16_t l3proto,
 121                                                  u_int8_t l4proto);
 122
 123struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u_int16_t l3proto,
 124                                                    u_int8_t l4proto);
 125void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 126
 127/* Protocol pernet registration. */
 128int nf_ct_l4proto_pernet_register(struct net *net,
 129                                  struct nf_conntrack_l4proto *proto);
 130void nf_ct_l4proto_pernet_unregister(struct net *net,
 131                                     struct nf_conntrack_l4proto *proto);
 132
 133/* Protocol global registration. */
 134int nf_ct_l4proto_register(struct nf_conntrack_l4proto *proto);
 135void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *proto);
 136
 137static inline void nf_ct_kfree_compat_sysctl_table(struct nf_proto_net *pn)
 138{
 139#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
 140        kfree(pn->ctl_compat_table);
 141        pn->ctl_compat_table = NULL;
 142#endif
 143}
 144
 145/* Generic netlink helpers */
 146int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 147                               const struct nf_conntrack_tuple *tuple);
 148int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 149                               struct nf_conntrack_tuple *t);
 150int nf_ct_port_nlattr_tuple_size(void);
 151extern const struct nla_policy nf_ct_port_nla_policy[];
 152
 153#ifdef CONFIG_SYSCTL
 154#define LOG_INVALID(net, proto)                         \
 155        ((net)->ct.sysctl_log_invalid == (proto) ||     \
 156         (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
 157#else
 158static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
 159#endif /* CONFIG_SYSCTL */
 160
 161#endif /*_NF_CONNTRACK_PROTOCOL_H*/
 162