linux-stable/include/linux/udp.h
David Howells 24a4e79d92 rxrpc: Fix ICMP/ICMP6 error handling
[ Upstream commit ac56a0b48d ]

Because rxrpc pretends to be a tunnel on top of a UDP/UDP6 socket, allowing
it to siphon off UDP packets early in the handling of received UDP packets
thereby avoiding the packet going through the UDP receive queue, it doesn't
get ICMP packets through the UDP ->sk_error_report() callback.  In fact, it
doesn't appear that there's any usable option for getting hold of ICMP
packets.

Fix this by adding a new UDP encap hook to distribute error messages for
UDP tunnels.  If the hook is set, then the tunnel driver will be able to
see ICMP packets.  The hook provides the offset into the packet of the UDP
header of the original packet that caused the notification.

An alternative would be to call the ->error_handler() hook - but that
requires that the skbuff be cloned (as ip_icmp_error() or ipv6_cmp_error()
do, though isn't really necessary or desirable in rxrpc's case is we want
to parse them there and then, not queue them).

Changes
=======
ver #3)
 - Fixed an uninitialised variable.

ver #2)
 - Fixed some missing CONFIG_AF_RXRPC_IPV6 conditionals.

Fixes: 5271953cad ("rxrpc: Use the UDP encap_rcv hook")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-09-15 11:30:05 +02:00

163 lines
4.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* 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 UDP protocol.
*
* Version: @(#)udp.h 1.0.2 04/28/93
*
* Author: Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
*/
#ifndef _LINUX_UDP_H
#define _LINUX_UDP_H
#include <net/inet_sock.h>
#include <linux/skbuff.h>
#include <net/netns/hash.h>
#include <uapi/linux/udp.h>
static inline struct udphdr *udp_hdr(const struct sk_buff *skb)
{
return (struct udphdr *)skb_transport_header(skb);
}
static inline struct udphdr *inner_udp_hdr(const struct sk_buff *skb)
{
return (struct udphdr *)skb_inner_transport_header(skb);
}
#define UDP_HTABLE_SIZE_MIN (CONFIG_BASE_SMALL ? 128 : 256)
static inline u32 udp_hashfn(const struct net *net, u32 num, u32 mask)
{
return (num + net_hash_mix(net)) & mask;
}
struct udp_sock {
/* inet_sock has to be the first member */
struct inet_sock inet;
#define udp_port_hash inet.sk.__sk_common.skc_u16hashes[0]
#define udp_portaddr_hash inet.sk.__sk_common.skc_u16hashes[1]
#define udp_portaddr_node inet.sk.__sk_common.skc_portaddr_node
int pending; /* Any pending frames ? */
unsigned int corkflag; /* Cork is required */
__u8 encap_type; /* Is this an Encapsulation socket? */
unsigned char no_check6_tx:1,/* Send zero UDP6 checksums on TX? */
no_check6_rx:1,/* Allow zero UDP6 checksums on RX? */
encap_enabled:1, /* This socket enabled encap
* processing; UDP tunnels and
* different encapsulation layer set
* this
*/
gro_enabled:1, /* Request GRO aggregation */
accept_udp_l4:1,
accept_udp_fraglist:1;
/*
* Following member retains the information to create a UDP header
* when the socket is uncorked.
*/
__u16 len; /* total length of pending frames */
__u16 gso_size;
/*
* Fields specific to UDP-Lite.
*/
__u16 pcslen;
__u16 pcrlen;
/* indicator bits used by pcflag: */
#define UDPLITE_BIT 0x1 /* set by udplite proto init function */
#define UDPLITE_SEND_CC 0x2 /* set via udplite setsockopt */
#define UDPLITE_RECV_CC 0x4 /* set via udplite setsocktopt */
__u8 pcflag; /* marks socket as UDP-Lite if > 0 */
__u8 unused[3];
/*
* For encapsulation sockets.
*/
int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
void (*encap_err_rcv)(struct sock *sk, struct sk_buff *skb, unsigned int udp_offset);
int (*encap_err_lookup)(struct sock *sk, struct sk_buff *skb);
void (*encap_destroy)(struct sock *sk);
/* GRO functions for UDP socket */
struct sk_buff * (*gro_receive)(struct sock *sk,
struct list_head *head,
struct sk_buff *skb);
int (*gro_complete)(struct sock *sk,
struct sk_buff *skb,
int nhoff);
/* udp_recvmsg try to use this before splicing sk_receive_queue */
struct sk_buff_head reader_queue ____cacheline_aligned_in_smp;
/* This field is dirtied by udp_recvmsg() */
int forward_deficit;
};
#define UDP_MAX_SEGMENTS (1 << 6UL)
static inline struct udp_sock *udp_sk(const struct sock *sk)
{
return (struct udp_sock *)sk;
}
static inline void udp_set_no_check6_tx(struct sock *sk, bool val)
{
udp_sk(sk)->no_check6_tx = val;
}
static inline void udp_set_no_check6_rx(struct sock *sk, bool val)
{
udp_sk(sk)->no_check6_rx = val;
}
static inline bool udp_get_no_check6_tx(struct sock *sk)
{
return udp_sk(sk)->no_check6_tx;
}
static inline bool udp_get_no_check6_rx(struct sock *sk)
{
return udp_sk(sk)->no_check6_rx;
}
static inline void udp_cmsg_recv(struct msghdr *msg, struct sock *sk,
struct sk_buff *skb)
{
int gso_size;
if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
gso_size = skb_shinfo(skb)->gso_size;
put_cmsg(msg, SOL_UDP, UDP_GRO, sizeof(gso_size), &gso_size);
}
}
static inline bool udp_unexpected_gso(struct sock *sk, struct sk_buff *skb)
{
if (!skb_is_gso(skb))
return false;
if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4 && !udp_sk(sk)->accept_udp_l4)
return true;
if (skb_shinfo(skb)->gso_type & SKB_GSO_FRAGLIST && !udp_sk(sk)->accept_udp_fraglist)
return true;
return false;
}
static inline void udp_allow_gso(struct sock *sk)
{
udp_sk(sk)->accept_udp_l4 = 1;
udp_sk(sk)->accept_udp_fraglist = 1;
}
#define udp_portaddr_for_each_entry(__sk, list) \
hlist_for_each_entry(__sk, list, __sk_common.skc_portaddr_node)
#define udp_portaddr_for_each_entry_rcu(__sk, list) \
hlist_for_each_entry_rcu(__sk, list, __sk_common.skc_portaddr_node)
#define IS_UDPLITE(__sk) (__sk->sk_protocol == IPPROTO_UDPLITE)
#endif /* _LINUX_UDP_H */