xref: /linux/include/net/protocol.h (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 	void			(*early_demux)(struct sk_buff *skb);
43 	int			(*handler)(struct sk_buff *skb);
44 	void			(*err_handler)(struct sk_buff *skb, u32 info);
45 	unsigned int		no_policy:1,
46 				netns_ok:1;
47 };
48 
49 #if IS_ENABLED(CONFIG_IPV6)
50 struct inet6_protocol {
51 	void	(*early_demux)(struct sk_buff *skb);
52 
53 	int	(*handler)(struct sk_buff *skb);
54 
55 	void	(*err_handler)(struct sk_buff *skb,
56 			       struct inet6_skb_parm *opt,
57 			       u8 type, u8 code, int offset,
58 			       __be32 info);
59 	unsigned int	flags;	/* INET6_PROTO_xxx */
60 };
61 
62 #define INET6_PROTO_NOPOLICY	0x1
63 #define INET6_PROTO_FINAL	0x2
64 #endif
65 
66 struct net_offload {
67 	struct offload_callbacks callbacks;
68 	unsigned int		 flags;	/* Flags used by IPv6 for now */
69 };
70 /* This should be set for any extension header which is compatible with GSO. */
71 #define INET6_PROTO_GSO_EXTHDR	0x1
72 
73 /* This is used to register socket interfaces for IP protocols.  */
74 struct inet_protosw {
75 	struct list_head list;
76 
77         /* These two fields form the lookup key.  */
78 	unsigned short	 type;	   /* This is the 2nd argument to socket(2). */
79 	unsigned short	 protocol; /* This is the L4 protocol number.  */
80 
81 	struct proto	 *prot;
82 	const struct proto_ops *ops;
83 
84 	char             no_check;   /* checksum on rcv/xmit/none? */
85 	unsigned char	 flags;      /* See INET_PROTOSW_* below.  */
86 };
87 #define INET_PROTOSW_REUSE 0x01	     /* Are ports automatically reusable? */
88 #define INET_PROTOSW_PERMANENT 0x02  /* Permanent protocols are unremovable. */
89 #define INET_PROTOSW_ICSK      0x04  /* Is this an inet_connection_sock? */
90 
91 extern const struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
92 extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
93 extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
94 
95 #if IS_ENABLED(CONFIG_IPV6)
96 extern const struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
97 #endif
98 
99 int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
100 int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
101 int inet_add_offload(const struct net_offload *prot, unsigned char num);
102 int inet_del_offload(const struct net_offload *prot, unsigned char num);
103 void inet_register_protosw(struct inet_protosw *p);
104 void inet_unregister_protosw(struct inet_protosw *p);
105 
106 #if IS_ENABLED(CONFIG_IPV6)
107 int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
108 int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
109 int inet6_register_protosw(struct inet_protosw *p);
110 void inet6_unregister_protosw(struct inet_protosw *p);
111 #endif
112 int inet6_add_offload(const struct net_offload *prot, unsigned char num);
113 int inet6_del_offload(const struct net_offload *prot, unsigned char num);
114 
115 #endif	/* _PROTOCOL_H */
116