xref: /linux/include/net/protocol.h (revision 4e0ae876f77bc01a7e77724dea57b4b82bd53244)
1 /*
2  * INET		An implementation of the TCP/IP protocol suite for the LINUX
3  *		operating system.  INET is implemented using the  BSD Socket
4  *		interface as the means of communication with the user level.
5  *
6  *		Definitions for the protocol dispatcher.
7  *
8  * Version:	@(#)protocol.h	1.0.2	05/07/93
9  *
10  * Author:	Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
11  *
12  *		This program is free software; you can redistribute it and/or
13  *		modify it under the terms of the GNU General Public License
14  *		as published by the Free Software Foundation; either version
15  *		2 of the License, or (at your option) any later version.
16  *
17  *	Changes:
18  *		Alan Cox	:	Added a name field and a frag handler
19  *					field for later.
20  *		Alan Cox	:	Cleaned up, and sorted types.
21  *		Pedro Roque	:	inet6 protocols
22  */
23 
24 #ifndef _PROTOCOL_H
25 #define _PROTOCOL_H
26 
27 #include <linux/in6.h>
28 #include <linux/skbuff.h>
29 #if IS_ENABLED(CONFIG_IPV6)
30 #include <linux/ipv6.h>
31 #endif
32 #include <linux/netdevice.h>
33 
34 /* This is one larger than the largest protocol value that can be
35  * found in an ipv4 or ipv6 header.  Since in both cases the protocol
36  * value is presented in a __u8, this is defined to be 256.
37  */
38 #define MAX_INET_PROTOS		256
39 
40 /* This is used to register protocols. */
41 struct net_protocol {
42 	int			(*early_demux)(struct sk_buff *skb);
43 	int			(*early_demux_handler)(struct sk_buff *skb);
44 	int			(*handler)(struct sk_buff *skb);
45 
46 	/* This returns an error if we weren't able to handle the error. */
47 	int			(*err_handler)(struct sk_buff *skb, u32 info);
48 
49 	unsigned int		no_policy:1,
50 				netns_ok:1,
51 				/* does the protocol do more stringent
52 				 * icmp tag validation than simple
53 				 * socket lookup?
54 				 */
55 				icmp_strict_tag_validation:1;
56 };
57 
58 #if IS_ENABLED(CONFIG_IPV6)
59 struct inet6_protocol {
60 	void	(*early_demux)(struct sk_buff *skb);
61 	void    (*early_demux_handler)(struct sk_buff *skb);
62 	int	(*handler)(struct sk_buff *skb);
63 
64 	/* This returns an error if we weren't able to handle the error. */
65 	int	(*err_handler)(struct sk_buff *skb,
66 			       struct inet6_skb_parm *opt,
67 			       u8 type, u8 code, int offset,
68 			       __be32 info);
69 
70 	unsigned int	flags;	/* INET6_PROTO_xxx */
71 };
72 
73 #define INET6_PROTO_NOPOLICY	0x1
74 #define INET6_PROTO_FINAL	0x2
75 #endif
76 
77 struct net_offload {
78 	struct offload_callbacks callbacks;
79 	unsigned int		 flags;	/* Flags used by IPv6 for now */
80 };
81 /* This should be set for any extension header which is compatible with GSO. */
82 #define INET6_PROTO_GSO_EXTHDR	0x1
83 
84 /* This is used to register socket interfaces for IP protocols.  */
85 struct inet_protosw {
86 	struct list_head list;
87 
88         /* These two fields form the lookup key.  */
89 	unsigned short	 type;	   /* This is the 2nd argument to socket(2). */
90 	unsigned short	 protocol; /* This is the L4 protocol number.  */
91 
92 	struct proto	 *prot;
93 	const struct proto_ops *ops;
94 
95 	unsigned char	 flags;      /* See INET_PROTOSW_* below.  */
96 };
97 #define INET_PROTOSW_REUSE 0x01	     /* Are ports automatically reusable? */
98 #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
99 #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
100 
101 extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
102 extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
103 extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
104 
105 #if IS_ENABLED(CONFIG_IPV6)
106 extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
107 #endif
108 
109 int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
110 int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
111 int inet_add_offload(const struct net_offload *prot, unsigned char num);
112 int inet_del_offload(const struct net_offload *prot, unsigned char num);
113 void inet_register_protosw(struct inet_protosw *p);
114 void inet_unregister_protosw(struct inet_protosw *p);
115 
116 #if IS_ENABLED(CONFIG_IPV6)
117 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
118 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
119 int inet6_register_protosw(struct inet_protosw *p);
120 void inet6_unregister_protosw(struct inet_protosw *p);
121 #endif
122 int inet6_add_offload(const struct net_offload *prot, unsigned char num);
123 int inet6_del_offload(const struct net_offload *prot, unsigned char num);
124 
125 #endif	/* _PROTOCOL_H */
126