LXR linux/include/net/netfilter/nf_conntrack

   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 * Header for use in defining a given L4 protocol for connection tracking.
   4 *
   5 * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
   6 *      - generalized L3 protocol dependent part.
   7 *
   8 * Derived from include/linux/netfiter_ipv4/ip_conntrack_protcol.h
   9 */
  10
  11#ifndef _NF_CONNTRACK_L4PROTO_H
  12#define _NF_CONNTRACK_L4PROTO_H
  13#include <linux/netlink.h>
  14#include <net/netlink.h>
  15#include <net/netfilter/nf_conntrack.h>
  16#include <net/netns/generic.h>
  17
  18struct seq_file;
  19
  20struct nf_conntrack_l4proto {
  21        /* L4 Protocol number. */
  22        u_int8_t l4proto;
  23
  24        /* Resolve clashes on insertion races. */
  25        bool allow_clash;
  26
  27        /* protoinfo nlattr size, closes a hole */
  28        u16 nlattr_size;
  29
  30        /* called by gc worker if table is full */
  31        bool (*can_early_drop)(const struct nf_conn *ct);
  32
  33        /* convert protoinfo to nfnetink attributes */
  34        int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
  35                         struct nf_conn *ct, bool destroy);
  36
  37        /* convert nfnetlink attributes to protoinfo */
  38        int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
  39
  40        int (*tuple_to_nlattr)(struct sk_buff *skb,
  41                               const struct nf_conntrack_tuple *t);
  42        /* Calculate tuple nlattr size */
  43        unsigned int (*nlattr_tuple_size)(void);
  44        int (*nlattr_to_tuple)(struct nlattr *tb[],
  45                               struct nf_conntrack_tuple *t,
  46                               u_int32_t flags);
  47        const struct nla_policy *nla_policy;
  48
  49        struct {
  50                int (*nlattr_to_obj)(struct nlattr *tb[],
  51                                     struct net *net, void *data);
  52                int (*obj_to_nlattr)(struct sk_buff *skb, const void *data);
  53
  54                u16 obj_size;
  55                u16 nlattr_max;
  56                const struct nla_policy *nla_policy;
  57        } ctnl_timeout;
  58#ifdef CONFIG_NF_CONNTRACK_PROCFS
  59        /* Print out the private part of the conntrack. */
  60        void (*print_conntrack)(struct seq_file *s, struct nf_conn *);
  61#endif
  62};
  63
  64bool icmp_pkt_to_tuple(const struct sk_buff *skb,
  65                       unsigned int dataoff,
  66                       struct net *net,
  67                       struct nf_conntrack_tuple *tuple);
  68
  69bool icmpv6_pkt_to_tuple(const struct sk_buff *skb,
  70                         unsigned int dataoff,
  71                         struct net *net,
  72                         struct nf_conntrack_tuple *tuple);
  73
  74bool nf_conntrack_invert_icmp_tuple(struct nf_conntrack_tuple *tuple,
  75                                    const struct nf_conntrack_tuple *orig);
  76bool nf_conntrack_invert_icmpv6_tuple(struct nf_conntrack_tuple *tuple,
  77                                      const struct nf_conntrack_tuple *orig);
  78
  79int nf_conntrack_inet_error(struct nf_conn *tmpl, struct sk_buff *skb,
  80                            unsigned int dataoff,
  81                            const struct nf_hook_state *state,
  82                            u8 l4proto,
  83                            union nf_inet_addr *outer_daddr);
  84
  85int nf_conntrack_icmpv4_error(struct nf_conn *tmpl,
  86                              struct sk_buff *skb,
  87                              unsigned int dataoff,
  88                              const struct nf_hook_state *state);
  89
  90int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
  91                              struct sk_buff *skb,
  92                              unsigned int dataoff,
  93                              const struct nf_hook_state *state);
  94
  95int nf_conntrack_icmp_packet(struct nf_conn *ct,
  96                             struct sk_buff *skb,
  97                             enum ip_conntrack_info ctinfo,
  98                             const struct nf_hook_state *state);
  99
 100int nf_conntrack_icmpv6_packet(struct nf_conn *ct,
 101                               struct sk_buff *skb,
 102                               enum ip_conntrack_info ctinfo,
 103                               const struct nf_hook_state *state);
 104
 105int nf_conntrack_udp_packet(struct nf_conn *ct,
 106                            struct sk_buff *skb,
 107                            unsigned int dataoff,
 108                            enum ip_conntrack_info ctinfo,
 109                            const struct nf_hook_state *state);
 110int nf_conntrack_udplite_packet(struct nf_conn *ct,
 111                                struct sk_buff *skb,
 112                                unsigned int dataoff,
 113                                enum ip_conntrack_info ctinfo,
 114                                const struct nf_hook_state *state);
 115int nf_conntrack_tcp_packet(struct nf_conn *ct,
 116                            struct sk_buff *skb,
 117                            unsigned int dataoff,
 118                            enum ip_conntrack_info ctinfo,
 119                            const struct nf_hook_state *state);
 120int nf_conntrack_dccp_packet(struct nf_conn *ct,
 121                             struct sk_buff *skb,
 122                             unsigned int dataoff,
 123                             enum ip_conntrack_info ctinfo,
 124                             const struct nf_hook_state *state);
 125int nf_conntrack_sctp_packet(struct nf_conn *ct,
 126                             struct sk_buff *skb,
 127                             unsigned int dataoff,
 128                             enum ip_conntrack_info ctinfo,
 129                             const struct nf_hook_state *state);
 130int nf_conntrack_gre_packet(struct nf_conn *ct,
 131                            struct sk_buff *skb,
 132                            unsigned int dataoff,
 133                            enum ip_conntrack_info ctinfo,
 134                            const struct nf_hook_state *state);
 135
 136void nf_conntrack_generic_init_net(struct net *net);
 137void nf_conntrack_tcp_init_net(struct net *net);
 138void nf_conntrack_udp_init_net(struct net *net);
 139void nf_conntrack_gre_init_net(struct net *net);
 140void nf_conntrack_dccp_init_net(struct net *net);
 141void nf_conntrack_sctp_init_net(struct net *net);
 142void nf_conntrack_icmp_init_net(struct net *net);
 143void nf_conntrack_icmpv6_init_net(struct net *net);
 144
 145/* Existing built-in generic protocol */
 146extern const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 147
 148#define MAX_NF_CT_PROTO IPPROTO_UDPLITE
 149
 150const struct nf_conntrack_l4proto *nf_ct_l4proto_find(u8 l4proto);
 151
 152/* Generic netlink helpers */
 153int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 154                               const struct nf_conntrack_tuple *tuple);
 155int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 156                               struct nf_conntrack_tuple *t,
 157                               u_int32_t flags);
 158unsigned int nf_ct_port_nlattr_tuple_size(void);
 159extern const struct nla_policy nf_ct_port_nla_policy[];
 160
 161#ifdef CONFIG_SYSCTL
 162__printf(4, 5) __cold
 163void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
 164                               const struct nf_conn *ct,
 165                               const struct nf_hook_state *state,
 166                               const char *fmt, ...);
 167__printf(4, 5) __cold
 168void nf_l4proto_log_invalid(const struct sk_buff *skb,
 169                            const struct nf_hook_state *state,
 170                            u8 protonum,
 171                            const char *fmt, ...);
 172#else
 173static inline __printf(4, 5) __cold
 174void nf_l4proto_log_invalid(const struct sk_buff *skb,
 175                            const struct nf_hook_state *state,
 176                            u8 protonum,
 177                            const char *fmt, ...) {}
 178static inline __printf(4, 5) __cold
 179void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
 180                               const struct nf_conn *ct,
 181                               const struct nf_hook_state *state,
 182                               const char *fmt, ...) { }
 183#endif /* CONFIG_SYSCTL */
 184
 185#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 186static inline struct nf_generic_net *nf_generic_pernet(struct net *net)
 187{
 188        return &net->ct.nf_ct_proto.generic;
 189}
 190
 191static inline struct nf_tcp_net *nf_tcp_pernet(struct net *net)
 192{
 193        return &net->ct.nf_ct_proto.tcp;
 194}
 195
 196static inline struct nf_udp_net *nf_udp_pernet(struct net *net)
 197{
 198        return &net->ct.nf_ct_proto.udp;
 199}
 200
 201static inline struct nf_icmp_net *nf_icmp_pernet(struct net *net)
 202{
 203        return &net->ct.nf_ct_proto.icmp;
 204}
 205
 206static inline struct nf_icmp_net *nf_icmpv6_pernet(struct net *net)
 207{
 208        return &net->ct.nf_ct_proto.icmpv6;
 209}
 210
 211/* Caller must check nf_ct_protonum(ct) is IPPROTO_TCP before calling. */
 212static inline void nf_ct_set_tcp_be_liberal(struct nf_conn *ct)
 213{
 214        ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
 215        ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
 216}
 217
 218/* Caller must check nf_ct_protonum(ct) is IPPROTO_TCP before calling. */
 219static inline bool nf_conntrack_tcp_established(const struct nf_conn *ct)
 220{
 221        return ct->proto.tcp.state == TCP_CONNTRACK_ESTABLISHED &&
 222               test_bit(IPS_ASSURED_BIT, &ct->status);
 223}
 224#endif
 225
 226#ifdef CONFIG_NF_CT_PROTO_DCCP
 227static inline struct nf_dccp_net *nf_dccp_pernet(struct net *net)
 228{
 229        return &net->ct.nf_ct_proto.dccp;
 230}
 231#endif
 232
 233#ifdef CONFIG_NF_CT_PROTO_SCTP
 234static inline struct nf_sctp_net *nf_sctp_pernet(struct net *net)
 235{
 236        return &net->ct.nf_ct_proto.sctp;
 237}
 238#endif
 239
 240#ifdef CONFIG_NF_CT_PROTO_GRE
 241static inline struct nf_gre_net *nf_gre_pernet(struct net *net)
 242{
 243        return &net->ct.nf_ct_proto.gre;
 244}
 245#endif
 246
 247#endif /*_NF_CONNTRACK_PROTOCOL_H*/
 248