alistair23-linux/include/net/protocol.h
Stefano Brivio 32bbd8793f net: Convert protocol error handlers from void to int
We'll need this to handle ICMP errors for tunnels without a sending socket
(i.e. FoU and GUE). There, we might have to look up different types of IP
tunnels, registered as network protocols, before we get a match, so we
want this for the error handlers of IPPROTO_IPIP and IPPROTO_IPV6 in both
inet_protos and inet6_protos. These error codes will be used in the next
patch.

For consistency, return sensible error codes in protocol error handlers
whenever handlers can't handle errors because, even if valid, they don't
match a protocol or any of its states.

This has no effect on existing error handling paths.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-08 17:13:08 -08:00

126 lines
4.2 KiB
C

/*
* INET An implementation of the TCP/IP protocol suite for the LINUX
* operating system. INET is implemented using the BSD Socket
* interface as the means of communication with the user level.
*
* Definitions for the protocol dispatcher.
*
* Version: @(#)protocol.h 1.0.2 05/07/93
*
* Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Changes:
* Alan Cox : Added a name field and a frag handler
* field for later.
* Alan Cox : Cleaned up, and sorted types.
* Pedro Roque : inet6 protocols
*/
#ifndef _PROTOCOL_H
#define _PROTOCOL_H
#include <linux/in6.h>
#include <linux/skbuff.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <linux/ipv6.h>
#endif
#include <linux/netdevice.h>
/* This is one larger than the largest protocol value that can be
* found in an ipv4 or ipv6 header. Since in both cases the protocol
* value is presented in a __u8, this is defined to be 256.
*/
#define MAX_INET_PROTOS 256
/* This is used to register protocols. */
struct net_protocol {
int (*early_demux)(struct sk_buff *skb);
int (*early_demux_handler)(struct sk_buff *skb);
int (*handler)(struct sk_buff *skb);
/* This returns an error if we weren't able to handle the error. */
int (*err_handler)(struct sk_buff *skb, u32 info);
unsigned int no_policy:1,
netns_ok:1,
/* does the protocol do more stringent
* icmp tag validation than simple
* socket lookup?
*/
icmp_strict_tag_validation:1;
};
#if IS_ENABLED(CONFIG_IPV6)
struct inet6_protocol {
void (*early_demux)(struct sk_buff *skb);
void (*early_demux_handler)(struct sk_buff *skb);
int (*handler)(struct sk_buff *skb);
/* This returns an error if we weren't able to handle the error. */
int (*err_handler)(struct sk_buff *skb,
struct inet6_skb_parm *opt,
u8 type, u8 code, int offset,
__be32 info);
unsigned int flags; /* INET6_PROTO_xxx */
};
#define INET6_PROTO_NOPOLICY 0x1
#define INET6_PROTO_FINAL 0x2
#endif
struct net_offload {
struct offload_callbacks callbacks;
unsigned int flags; /* Flags used by IPv6 for now */
};
/* This should be set for any extension header which is compatible with GSO. */
#define INET6_PROTO_GSO_EXTHDR 0x1
/* This is used to register socket interfaces for IP protocols. */
struct inet_protosw {
struct list_head list;
/* These two fields form the lookup key. */
unsigned short type; /* This is the 2nd argument to socket(2). */
unsigned short protocol; /* This is the L4 protocol number. */
struct proto *prot;
const struct proto_ops *ops;
unsigned char flags; /* See INET_PROTOSW_* below. */
};
#define INET_PROTOSW_REUSE 0x01 /* Are ports automatically reusable? */
#define INET_PROTOSW_PERMANENT 0x02 /* Permanent protocols are unremovable. */
#define INET_PROTOSW_ICSK 0x04 /* Is this an inet_connection_sock? */
extern struct net_protocol __rcu *inet_protos[MAX_INET_PROTOS];
extern const struct net_offload __rcu *inet_offloads[MAX_INET_PROTOS];
extern const struct net_offload __rcu *inet6_offloads[MAX_INET_PROTOS];
#if IS_ENABLED(CONFIG_IPV6)
extern struct inet6_protocol __rcu *inet6_protos[MAX_INET_PROTOS];
#endif
int inet_add_protocol(const struct net_protocol *prot, unsigned char num);
int inet_del_protocol(const struct net_protocol *prot, unsigned char num);
int inet_add_offload(const struct net_offload *prot, unsigned char num);
int inet_del_offload(const struct net_offload *prot, unsigned char num);
void inet_register_protosw(struct inet_protosw *p);
void inet_unregister_protosw(struct inet_protosw *p);
#if IS_ENABLED(CONFIG_IPV6)
int inet6_add_protocol(const struct inet6_protocol *prot, unsigned char num);
int inet6_del_protocol(const struct inet6_protocol *prot, unsigned char num);
int inet6_register_protosw(struct inet_protosw *p);
void inet6_unregister_protosw(struct inet_protosw *p);
#endif
int inet6_add_offload(const struct net_offload *prot, unsigned char num);
int inet6_del_offload(const struct net_offload *prot, unsigned char num);
#endif /* _PROTOCOL_H */