1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * INET		An implementation of the TCP/IP protocol suite for the LINUX
4  *		operating system.  INET is implemented using the  BSD Socket
5  *		interface as the means of communication with the user level.
6  *
7  *		Definitions for the protocol dispatcher.
8  *
9  * Version:	@(#)protocol.h	1.0.2	05/07/93
10  *
11  * Author:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
12  *
13  *	Changes:
14  *		Alan Cox	:	Added a name field and a frag handler
15  *					field for later.
16  *		Alan Cox	:	Cleaned up, and sorted types.
17  *		Pedro Roque	:	inet6 protocols
18  */
19 
20 #ifndef _PROTOCOL_H
21 #define _PROTOCOL_H
22 
23 #include <linux/in6.h>
24 #include <linux/skbuff.h>
25 #if IS_ENABLED(CONFIG_IPV6)
26 #include <linux/ipv6.h>
27 #endif
28 #include <linux/netdevice.h>
29 
30 /* This is one larger than the largest protocol value that can be
31  * found in an ipv4 or ipv6 header.  Since in both cases the protocol
32  * value is presented in a __u8, this is defined to be 256.
33  */
34 #define MAX_INET_PROTOS		256
35 
36 /* This is used to register protocols. */
37 struct net_protocol {
38 	int			(*early_demux)(struct sk_buff *skb);
39 	int			(*early_demux_handler)(struct sk_buff *skb);
40 	int			(*handler)(struct sk_buff *skb);
41 
42 	/* This returns an error if we weren't able to handle the error. */
43 	int			(*err_handler)(struct sk_buff *skb, u32 info);
44 
45 	unsigned int		no_policy:1,
46 				/* does the protocol do more stringent
47 				 * icmp tag validation than simple
48 				 * socket lookup?
49 				 */
50 				icmp_strict_tag_validation:1;
51 };
52 
53 #if IS_ENABLED(CONFIG_IPV6)
54 struct inet6_protocol {
55 	void	(*early_demux)(struct sk_buff *skb);
56 	void    (*early_demux_handler)(struct sk_buff *skb);
57 	int	(*handler)(struct sk_buff *skb);
58 
59 	/* This returns an error if we weren't able to handle the error. */
60 	int	(*err_handler)(struct sk_buff *skb,
61 			       struct inet6_skb_parm *opt,
62 			       u8 type, u8 code, int offset,
63 			       __be32 info);
64 
65 	unsigned int	flags;	/* INET6_PROTO_xxx */
66 };
67 
68 #define INET6_PROTO_NOPOLICY	0x1
69 #define INET6_PROTO_FINAL	0x2
70 #endif
71 
72 struct net_offload {
73 	struct offload_callbacks callbacks;
74 	unsigned int		 flags;	/* Flags used by IPv6 for now */
75 };
76 /* This should be set for any extension header which is compatible with GSO. */
77 #define INET6_PROTO_GSO_EXTHDR	0x1
78 
79 /* This is used to register socket interfaces for IP protocols.  */
80 struct inet_protosw {
81 	struct list_head list;
82 
83         /* These two fields form the lookup key.  */
84 	unsigned short	 type;	   /* This is the 2nd argument to socket(2). */
85 	unsigned short	 protocol; /* This is the L4 protocol number.  */
86 
87 	struct proto	 *prot;
88 	const struct proto_ops *ops;
89 
90 	unsigned char	 flags;      /* See INET_PROTOSW_* below.  */
91 };
92 #define INET_PROTOSW_REUSE 0x01	     /* Are ports automatically reusable? */
93 #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
94 #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
95 
96 extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
97 extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
98 extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
99 
100 #if IS_ENABLED(CONFIG_IPV6)
101 extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
102 #endif
103 
104 int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
105 int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
106 int inet_add_offload(const struct net_offload *prot, unsigned char num);
107 int inet_del_offload(const struct net_offload *prot, unsigned char num);
108 void inet_register_protosw(struct inet_protosw *p);
109 void inet_unregister_protosw(struct inet_protosw *p);
110 
111 #if IS_ENABLED(CONFIG_IPV6)
112 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
113 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
114 int inet6_register_protosw(struct inet_protosw *p);
115 void inet6_unregister_protosw(struct inet_protosw *p);
116 #endif
117 int inet6_add_offload(const struct net_offload *prot, unsigned char num);
118 int inet6_del_offload(const struct net_offload *prot, unsigned char num);
119 
120 #endif	/* _PROTOCOL_H */
121