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        /* Try to fill in the third arg: dataoff is offset past network protocol
  27           hdr.  Return true if possible. */
  28        bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
  29                             struct nf_conntrack_tuple *tuple);
  30
  31        /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  32         * Some packets can't be inverted: return 0 in that case.
  33         */
  34        bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  35                             const struct nf_conntrack_tuple *orig);
  36
  37        /* Returns verdict for packet, or -1 for invalid. */
  38        int (*packet)(struct nf_conn *ct,
  39                      const struct sk_buff *skb,
  40                      unsigned int dataoff,
  41                      enum ip_conntrack_info ctinfo,
  42                      u_int8_t pf,
  43                      unsigned int hooknum,
  44                      unsigned int *timeouts);
  45
  46        /* Called when a new connection for this protocol found;
  47         * returns TRUE if it's OK.  If so, packet() called next. */
  48        bool (*new)(struct nf_conn *ct, const struct sk_buff *skb,
  49                    unsigned int dataoff, unsigned int *timeouts);
  50
  51        /* Called when a conntrack entry is destroyed */
  52        void (*destroy)(struct nf_conn *ct);
  53
  54        int (*error)(struct net *net, struct nf_conn *tmpl, struct sk_buff *skb,
  55                     unsigned int dataoff, enum ip_conntrack_info *ctinfo,
  56                     u_int8_t pf, unsigned int hooknum);
  57
  58        /* Print out the per-protocol part of the tuple. Return like seq_* */
  59        int (*print_tuple)(struct seq_file *s,
  60                           const struct nf_conntrack_tuple *);
  61
  62        /* Print out the private part of the conntrack. */
  63        int (*print_conntrack)(struct seq_file *s, struct nf_conn *);
  64
  65        /* Return the array of timeouts for this protocol. */
  66        unsigned int *(*get_timeouts)(struct net *net);
  67
  68        /* convert protoinfo to nfnetink attributes */
  69        int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
  70                         struct nf_conn *ct);
  71        /* Calculate protoinfo nlattr size */
  72        int (*nlattr_size)(void);
  73
  74        /* convert nfnetlink attributes to protoinfo */
  75        int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
  76
  77        int (*tuple_to_nlattr)(struct sk_buff *skb,
  78                               const struct nf_conntrack_tuple *t);
  79        /* Calculate tuple nlattr size */
  80        int (*nlattr_tuple_size)(void);
  81        int (*nlattr_to_tuple)(struct nlattr *tb[],
  82                               struct nf_conntrack_tuple *t);
  83        const struct nla_policy *nla_policy;
  84
  85        size_t nla_size;
  86
  87#if IS_ENABLED(CONFIG_NF_CT_NETLINK_TIMEOUT)
  88        struct {
  89                size_t obj_size;
  90                int (*nlattr_to_obj)(struct nlattr *tb[],
  91                                     struct net *net, void *data);
  92                int (*obj_to_nlattr)(struct sk_buff *skb, const void *data);
  93
  94                unsigned int nlattr_max;
  95                const struct nla_policy *nla_policy;
  96        } ctnl_timeout;
  97#endif
  98        int     *net_id;
  99        /* Init l4proto pernet data */
 100        int (*init_net)(struct net *net, u_int16_t proto);
 101
 102        /* Return the per-net protocol part. */
 103        struct nf_proto_net *(*get_net_proto)(struct net *net);
 104
 105        /* Protocol name */
 106        const char *name;
 107
 108        /* Module (if any) which this is connected to. */
 109        struct module *me;
 110};
 111
 112/* Existing built-in generic protocol */
 113extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 114
 115#define MAX_NF_CT_PROTO 256
 116
 117extern struct nf_conntrack_l4proto *
 118__nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto);
 119
 120extern struct nf_conntrack_l4proto *
 121nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto);
 122extern void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 123
 124/* Protocol pernet registration. */
 125extern int nf_ct_l4proto_pernet_register(struct net *net,
 126                                         struct nf_conntrack_l4proto *proto);
 127extern void nf_ct_l4proto_pernet_unregister(struct net *net,
 128                                            struct nf_conntrack_l4proto *proto);
 129
 130/* Protocol global registration. */
 131extern int nf_ct_l4proto_register(struct nf_conntrack_l4proto *proto);
 132extern void nf_ct_l4proto_unregister(struct nf_conntrack_l4proto *proto);
 133
 134static inline void nf_ct_kfree_compat_sysctl_table(struct nf_proto_net *pn)
 135{
 136#if defined(CONFIG_SYSCTL) && defined(CONFIG_NF_CONNTRACK_PROC_COMPAT)
 137        kfree(pn->ctl_compat_table);
 138        pn->ctl_compat_table = NULL;
 139#endif
 140}
 141
 142/* Generic netlink helpers */
 143extern int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 144                                      const struct nf_conntrack_tuple *tuple);
 145extern int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 146                                      struct nf_conntrack_tuple *t);
 147extern int nf_ct_port_nlattr_tuple_size(void);
 148extern const struct nla_policy nf_ct_port_nla_policy[];
 149
 150#ifdef CONFIG_SYSCTL
 151#ifdef DEBUG_INVALID_PACKETS
 152#define LOG_INVALID(net, proto)                         \
 153        ((net)->ct.sysctl_log_invalid == (proto) ||     \
 154         (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
 155#else
 156#define LOG_INVALID(net, proto)                         \
 157        (((net)->ct.sysctl_log_invalid == (proto) ||    \
 158          (net)->ct.sysctl_log_invalid == IPPROTO_RAW)  \
 159         && net_ratelimit())
 160#endif
 161#else
 162static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
 163#endif /* CONFIG_SYSCTL */
 164
 165#endif /*_NF_CONNTRACK_PROTOCOL_H*/
 166