xref: /linux/include/net/protocol.h (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
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			(*handler)(struct sk_buff *skb);
39 
40 	/* This returns an error if we weren't able to handle the error. */
41 	int			(*err_handler)(struct sk_buff *skb, u32 info);
42 
43 	unsigned int		no_policy:1,
44 				/* does the protocol do more stringent
45 				 * icmp tag validation than simple
46 				 * socket lookup?
47 				 */
48 				icmp_strict_tag_validation:1;
49 	u32			secret;
50 };
51 
52 #if IS_ENABLED(CONFIG_IPV6)
53 struct inet6_protocol {
54 	int	(*handler)(struct sk_buff *skb);
55 
56 	/* This returns an error if we weren't able to handle the error. */
57 	int	(*err_handler)(struct sk_buff *skb,
58 			       struct inet6_skb_parm *opt,
59 			       u8 type, u8 code, int offset,
60 			       __be32 info);
61 
62 	unsigned int	flags;	/* INET6_PROTO_xxx */
63 	u32		secret;
64 };
65 
66 #define INET6_PROTO_NOPOLICY	0x1
67 #define INET6_PROTO_FINAL	0x2
68 #endif
69 
70 struct net_offload {
71 	struct offload_callbacks callbacks;
72 	unsigned int		 flags;	/* Flags used by IPv6 for now */
73 	u32			 secret;
74 };
75 /* This should be set for any extension header which is compatible with GSO. */
76 #define INET6_PROTO_GSO_EXTHDR	0x1
77 
78 /* This is used to register socket interfaces for IP protocols.  */
79 struct inet_protosw {
80 	struct list_head list;
81 
82         /* These two fields form the lookup key.  */
83 	unsigned short	 type;	   /* This is the 2nd argument to socket(2). */
84 	unsigned short	 protocol; /* This is the L4 protocol number.  */
85 
86 	struct proto	 *prot;
87 	const struct proto_ops *ops;
88 
89 	unsigned char	 flags;      /* See INET_PROTOSW_* below.  */
90 };
91 #define INET_PROTOSW_REUSE 0x01	     /* Are ports automatically reusable? */
92 #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
93 #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
94 
95 extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
96 extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
97 extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
98 
99 #if IS_ENABLED(CONFIG_IPV6)
100 extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
101 #endif
102 
103 int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
104 int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
105 int inet_add_offload(const struct net_offload *prot, unsigned char num);
106 int inet_del_offload(const struct net_offload *prot, unsigned char num);
107 void inet_register_protosw(struct inet_protosw *p);
108 void inet_unregister_protosw(struct inet_protosw *p);
109 
110 #if IS_ENABLED(CONFIG_IPV6)
111 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
112 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
113 int inet6_register_protosw(struct inet_protosw *p);
114 void inet6_unregister_protosw(struct inet_protosw *p);
115 #endif
116 int inet6_add_offload(const struct net_offload *prot, unsigned char num);
117 int inet6_del_offload(const struct net_offload *prot, unsigned char num);
118 
119 #endif	/* _PROTOCOL_H */
120