include/net/netfilter/nf_conntrack_l4proto.h

   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
  18 struct seq_file;
  19
  20 struct 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         /* Try to fill in the third arg: dataoff is offset past network protocol
  31            hdr.  Return true if possible. */
  32         bool (*pkt_to_tuple)(const struct sk_buff *skb, unsigned int dataoff,
  33                              struct net *net, struct nf_conntrack_tuple *tuple);
  34
  35         /* Invert the per-proto part of the tuple: ie. turn xmit into reply.
  36          * Only used by icmp, most protocols use a generic version.
  37          */
  38         bool (*invert_tuple)(struct nf_conntrack_tuple *inverse,
  39                              const struct nf_conntrack_tuple *orig);
  40
  41         /* Returns verdict for packet, or -1 for invalid. */
  42         int (*packet)(struct nf_conn *ct,
  43                       struct sk_buff *skb,
  44                       unsigned int dataoff,
  45                       enum ip_conntrack_info ctinfo,
  46                       const struct nf_hook_state *state);
  47
  48         /* Called when a conntrack entry is destroyed */
  49         void (*destroy)(struct nf_conn *ct);
  50
  51         /* called by gc worker if table is full */
  52         bool (*can_early_drop)(const struct nf_conn *ct);
  53
  54         /* convert protoinfo to nfnetink attributes */
  55         int (*to_nlattr)(struct sk_buff *skb, struct nlattr *nla,
  56                          struct nf_conn *ct);
  57
  58         /* convert nfnetlink attributes to protoinfo */
  59         int (*from_nlattr)(struct nlattr *tb[], struct nf_conn *ct);
  60
  61         int (*tuple_to_nlattr)(struct sk_buff *skb,
  62                                const struct nf_conntrack_tuple *t);
  63         /* Calculate tuple nlattr size */
  64         unsigned int (*nlattr_tuple_size)(void);
  65         int (*nlattr_to_tuple)(struct nlattr *tb[],
  66                                struct nf_conntrack_tuple *t);
  67         const struct nla_policy *nla_policy;
  68
  69         struct {
  70                 int (*nlattr_to_obj)(struct nlattr *tb[],
  71                                      struct net *net, void *data);
  72                 int (*obj_to_nlattr)(struct sk_buff *skb, const void *data);
  73
  74                 u16 obj_size;
  75                 u16 nlattr_max;
  76                 const struct nla_policy *nla_policy;
  77         } ctnl_timeout;
  78 #ifdef CONFIG_NF_CONNTRACK_PROCFS
  79         /* Print out the private part of the conntrack. */
  80         void (*print_conntrack)(struct seq_file *s, struct nf_conn *);
  81 #endif
  82         unsigned int    *net_id;
  83         /* Init l4proto pernet data */
  84         int (*init_net)(struct net *net);
  85
  86         /* Return the per-net protocol part. */
  87         struct nf_proto_net *(*get_net_proto)(struct net *net);
  88
  89         /* Module (if any) which this is connected to. */
  90         struct module *me;
  91 };
  92
  93 int nf_conntrack_icmpv4_error(struct nf_conn *tmpl,
  94                               struct sk_buff *skb,
  95                               unsigned int dataoff,
  96                               const struct nf_hook_state *state);
  97
  98 int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
  99                               struct sk_buff *skb,
 100                               unsigned int dataoff,
 101                               const struct nf_hook_state *state);
 102
 103 int nf_conntrack_icmp_packet(struct nf_conn *ct,
 104                              struct sk_buff *skb,
 105                              enum ip_conntrack_info ctinfo,
 106                              const struct nf_hook_state *state);
 107
 108 int nf_conntrack_icmpv6_packet(struct nf_conn *ct,
 109                                struct sk_buff *skb,
 110                                enum ip_conntrack_info ctinfo,
 111                                const struct nf_hook_state *state);
 112
 113 int nf_conntrack_udp_packet(struct nf_conn *ct,
 114                             struct sk_buff *skb,
 115                             unsigned int dataoff,
 116                             enum ip_conntrack_info ctinfo,
 117                             const struct nf_hook_state *state);
 118 int nf_conntrack_udplite_packet(struct nf_conn *ct,
 119                                 struct sk_buff *skb,
 120                                 unsigned int dataoff,
 121                                 enum ip_conntrack_info ctinfo,
 122                                 const struct nf_hook_state *state);
 123 int nf_conntrack_tcp_packet(struct nf_conn *ct,
 124                             struct sk_buff *skb,
 125                             unsigned int dataoff,
 126                             enum ip_conntrack_info ctinfo,
 127                             const struct nf_hook_state *state);
 128 int nf_conntrack_dccp_packet(struct nf_conn *ct,
 129                              struct sk_buff *skb,
 130                              unsigned int dataoff,
 131                              enum ip_conntrack_info ctinfo,
 132                              const struct nf_hook_state *state);
 133 int nf_conntrack_sctp_packet(struct nf_conn *ct,
 134                              struct sk_buff *skb,
 135                              unsigned int dataoff,
 136                              enum ip_conntrack_info ctinfo,
 137                              const struct nf_hook_state *state);
 138
 139 /* Existing built-in generic protocol */
 140 extern const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 141
 142 #define MAX_NF_CT_PROTO IPPROTO_UDPLITE
 143
 144 const struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u8 l4proto);
 145
 146 const struct nf_conntrack_l4proto *nf_ct_l4proto_find_get(u8 l4proto);
 147 void nf_ct_l4proto_put(const struct nf_conntrack_l4proto *p);
 148
 149 /* Protocol pernet registration. */
 150 int nf_ct_l4proto_pernet_register_one(struct net *net,
 151                                 const struct nf_conntrack_l4proto *proto);
 152 void nf_ct_l4proto_pernet_unregister_one(struct net *net,
 153                                 const struct nf_conntrack_l4proto *proto);
 154 int nf_ct_l4proto_pernet_register(struct net *net,
 155                                   const struct nf_conntrack_l4proto *const proto[],
 156                                   unsigned int num_proto);
 157 void nf_ct_l4proto_pernet_unregister(struct net *net,
 158                                 const struct nf_conntrack_l4proto *const proto[],
 159                                 unsigned int num_proto);
 160
 161 /* Protocol global registration. */
 162 int nf_ct_l4proto_register_one(const struct nf_conntrack_l4proto *proto);
 163 void nf_ct_l4proto_unregister_one(const struct nf_conntrack_l4proto *proto);
 164
 165 /* Generic netlink helpers */
 166 int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
 167                                const struct nf_conntrack_tuple *tuple);
 168 int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
 169                                struct nf_conntrack_tuple *t);
 170 unsigned int nf_ct_port_nlattr_tuple_size(void);
 171 extern const struct nla_policy nf_ct_port_nla_policy[];
 172
 173 #ifdef CONFIG_SYSCTL
 174 __printf(3, 4) __cold
 175 void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
 176                                const struct nf_conn *ct,
 177                                const char *fmt, ...);
 178 __printf(5, 6) __cold
 179 void nf_l4proto_log_invalid(const struct sk_buff *skb,
 180                             struct net *net,
 181                             u16 pf, u8 protonum,
 182                             const char *fmt, ...);
 183 #else
 184 static inline __printf(5, 6) __cold
 185 void nf_l4proto_log_invalid(const struct sk_buff *skb, struct net *net,
 186                             u16 pf, u8 protonum, const char *fmt, ...) {}
 187 static inline __printf(3, 4) __cold
 188 void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
 189                                const struct nf_conn *ct,
 190                                const char *fmt, ...) { }
 191 #endif /* CONFIG_SYSCTL */
 192
 193 static inline struct nf_generic_net *nf_generic_pernet(struct net *net)
 194 {
 195        return &net->ct.nf_ct_proto.generic;
 196 }
 197
 198 static inline struct nf_tcp_net *nf_tcp_pernet(struct net *net)
 199 {
 200        return &net->ct.nf_ct_proto.tcp;
 201 }
 202
 203 static inline struct nf_udp_net *nf_udp_pernet(struct net *net)
 204 {
 205        return &net->ct.nf_ct_proto.udp;
 206 }
 207
 208 static inline struct nf_icmp_net *nf_icmp_pernet(struct net *net)
 209 {
 210        return &net->ct.nf_ct_proto.icmp;
 211 }
 212
 213 static inline struct nf_icmp_net *nf_icmpv6_pernet(struct net *net)
 214 {
 215        return &net->ct.nf_ct_proto.icmpv6;
 216 }
 217
 218 #ifdef CONFIG_NF_CT_PROTO_DCCP
 219 static inline struct nf_dccp_net *nf_dccp_pernet(struct net *net)
 220 {
 221        return &net->ct.nf_ct_proto.dccp;
 222 }
 223 #endif
 224
 225 #ifdef CONFIG_NF_CT_PROTO_SCTP
 226 static inline struct nf_sctp_net *nf_sctp_pernet(struct net *net)
 227 {
 228        return &net->ct.nf_ct_proto.sctp;
 229 }
 230 #endif
 231
 232 #endif /*_NF_CONNTRACK_PROTOCOL_H*/