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         /* 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);
 101
 102         /* Protocol name */
 103         const char *name;
 104
 105         /* Module (if any) which this is connected to. */
 106         struct module *me;
 107 };
 108
 109 /* Existing built-in generic protocol */
 110 extern struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 111
 112 #define MAX_NF_CT_PROTO 256
 113
 114 extern struct nf_conntrack_l4proto *
 115 __nf_ct_l4proto_find(u_int16_t l3proto, u_int8_t l4proto);
 116
 117 extern struct nf_conntrack_l4proto *
 118 nf_ct_l4proto_find_get(u_int16_t l3proto, u_int8_t l4proto);
 119 extern void nf_ct_l4proto_put(struct nf_conntrack_l4proto *p);
 120
 121 /* Protocol registration. */
 122 extern int nf_conntrack_l4proto_register(struct net *net,
 123                                          struct nf_conntrack_l4proto *proto);
 124 extern void nf_conntrack_l4proto_unregister(struct net *net,
 125                                             struct nf_conntrack_l4proto *proto);
 126
 127 /* Generic netlink helpers */
 128 extern int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 129                                       const struct nf_conntrack_tuple *tuple);
 130 extern int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 131                                       struct nf_conntrack_tuple *t);
 132 extern int nf_ct_port_nlattr_tuple_size(void);
 133 extern const struct nla_policy nf_ct_port_nla_policy[];
 134
 135 #ifdef CONFIG_SYSCTL
 136 #ifdef DEBUG_INVALID_PACKETS
 137 #define LOG_INVALID(net, proto)                         \
 138         ((net)->ct.sysctl_log_invalid == (proto) ||     \
 139          (net)->ct.sysctl_log_invalid == IPPROTO_RAW)
 140 #else
 141 #define LOG_INVALID(net, proto)                         \
 142         (((net)->ct.sysctl_log_invalid == (proto) ||    \
 143           (net)->ct.sysctl_log_invalid == IPPROTO_RAW)  \
 144          && net_ratelimit())
 145 #endif
 146 #else
 147 static inline int LOG_INVALID(struct net *net, int proto) { return 0; }
 148 #endif /* CONFIG_SYSCTL */
 149
 150 #endif /*_NF_CONNTRACK_PROTOCOL_H*/