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
 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 nfnetlink 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_sctp_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_gre_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);
130
131void nf_conntrack_generic_init_net(struct net *net);
132void nf_conntrack_tcp_init_net(struct net *net);
133void nf_conntrack_udp_init_net(struct net *net);
134void nf_conntrack_gre_init_net(struct net *net);
135void nf_conntrack_sctp_init_net(struct net *net);
136void nf_conntrack_icmp_init_net(struct net *net);
137void nf_conntrack_icmpv6_init_net(struct net *net);
138
139/* Existing built-in generic protocol */
140extern const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
141
142#define MAX_NF_CT_PROTO IPPROTO_UDPLITE
143
144const struct nf_conntrack_l4proto *nf_ct_l4proto_find(u8 l4proto);
145
146/* Generic netlink helpers */
147int nf_ct_port_tuple_to_nlattr(struct sk_buff *skb,
148			       const struct nf_conntrack_tuple *tuple);
149int nf_ct_port_nlattr_to_tuple(struct nlattr *tb[],
150			       struct nf_conntrack_tuple *t,
151			       u_int32_t flags);
152unsigned int nf_ct_port_nlattr_tuple_size(void);
153extern const struct nla_policy nf_ct_port_nla_policy[];
154
155#ifdef CONFIG_SYSCTL
156__printf(4, 5) __cold
157void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
158			       const struct nf_conn *ct,
159			       const struct nf_hook_state *state,
160			       const char *fmt, ...);
161__printf(4, 5) __cold
162void nf_l4proto_log_invalid(const struct sk_buff *skb,
163			    const struct nf_hook_state *state,
164			    u8 protonum,
165			    const char *fmt, ...);
166#else
167static inline __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, ...) {}
172static inline __printf(4, 5) __cold
173void nf_ct_l4proto_log_invalid(const struct sk_buff *skb,
174			       const struct nf_conn *ct,
175			       const struct nf_hook_state *state,
176			       const char *fmt, ...) { }
177#endif /* CONFIG_SYSCTL */
178
179#if IS_ENABLED(CONFIG_NF_CONNTRACK)
180static inline struct nf_generic_net *nf_generic_pernet(struct net *net)
181{
182	return &net->ct.nf_ct_proto.generic;
183}
184
185static inline struct nf_tcp_net *nf_tcp_pernet(struct net *net)
186{
187	return &net->ct.nf_ct_proto.tcp;
188}
189
190static inline struct nf_udp_net *nf_udp_pernet(struct net *net)
191{
192	return &net->ct.nf_ct_proto.udp;
193}
194
195static inline struct nf_icmp_net *nf_icmp_pernet(struct net *net)
196{
197	return &net->ct.nf_ct_proto.icmp;
198}
199
200static inline struct nf_icmp_net *nf_icmpv6_pernet(struct net *net)
201{
202	return &net->ct.nf_ct_proto.icmpv6;
203}
204
205/* Caller must check nf_ct_protonum(ct) is IPPROTO_TCP before calling. */
206static inline void nf_ct_set_tcp_be_liberal(struct nf_conn *ct)
207{
208	ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
209	ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
210}
211
212/* Caller must check nf_ct_protonum(ct) is IPPROTO_TCP before calling. */
213static inline bool nf_conntrack_tcp_established(const struct nf_conn *ct)
214{
215	return ct->proto.tcp.state == TCP_CONNTRACK_ESTABLISHED &&
216	       test_bit(IPS_ASSURED_BIT, &ct->status);
217}
218#endif
219
220#ifdef CONFIG_NF_CT_PROTO_SCTP
221static inline struct nf_sctp_net *nf_sctp_pernet(struct net *net)
222{
223	return &net->ct.nf_ct_proto.sctp;
224}
225#endif
226
227#ifdef CONFIG_NF_CT_PROTO_GRE
228static inline struct nf_gre_net *nf_gre_pernet(struct net *net)
229{
230	return &net->ct.nf_ct_proto.gre;
231}
232#endif
233
234#endif /*_NF_CONNTRACK_PROTOCOL_H*/