linux/include/net/udp_tunnel.h
Stefano Brivio a36e185e8c udp: Handle ICMP errors for tunnels with same destination port on both endpoints
For both IPv4 and IPv6, if we can't match errors to a socket, try
tunnels before ignoring them. Look up a socket with the original source
and destination ports as found in the UDP packet inside the ICMP payload,
this will work for tunnels that force the same destination port for both
endpoints, i.e. VXLAN and GENEVE.

Actually, lwtunnels could break this assumption if they are configured by
an external control plane to have different destination ports on the
endpoints: in this case, we won't be able to trace ICMP messages back to
them.

For IPv6 redirect messages, call ip6_redirect() directly with the output
interface argument set to the interface we received the packet from (as
it's the very interface we should build the exception on), otherwise the
new nexthop will be rejected. There's no such need for IPv4.

Tunnels can now export an encap_err_lookup() operation that indicates a
match. Pass the packet to the lookup function, and if the tunnel driver
reports a matching association, continue with regular ICMP error handling.

v2:
- Added newline between network and transport header sets in
  __udp{4,6}_lib_err_encap() (David Miller)
- Removed redundant skb_reset_network_header(skb); in
  __udp4_lib_err_encap()
- Removed redundant reassignment of iph in __udp4_lib_err_encap()
  (Sabrina Dubroca)
- Edited comment to __udp{4,6}_lib_err_encap() to reflect the fact this
  won't work with lwtunnels configured to use asymmetric ports. By the way,
  it's VXLAN, not VxLAN (Jiri Benc)

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

186 lines
5.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __NET_UDP_TUNNEL_H
#define __NET_UDP_TUNNEL_H
#include <net/ip_tunnels.h>
#include <net/udp.h>
#if IS_ENABLED(CONFIG_IPV6)
#include <net/ipv6.h>
#include <net/addrconf.h>
#endif
struct udp_port_cfg {
u8 family;
/* Used only for kernel-created sockets */
union {
struct in_addr local_ip;
#if IS_ENABLED(CONFIG_IPV6)
struct in6_addr local_ip6;
#endif
};
union {
struct in_addr peer_ip;
#if IS_ENABLED(CONFIG_IPV6)
struct in6_addr peer_ip6;
#endif
};
__be16 local_udp_port;
__be16 peer_udp_port;
unsigned int use_udp_checksums:1,
use_udp6_tx_checksums:1,
use_udp6_rx_checksums:1,
ipv6_v6only:1;
};
int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
struct socket **sockp);
#if IS_ENABLED(CONFIG_IPV6)
int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
struct socket **sockp);
#else
static inline int udp_sock_create6(struct net *net, struct udp_port_cfg *cfg,
struct socket **sockp)
{
return 0;
}
#endif
static inline int udp_sock_create(struct net *net,
struct udp_port_cfg *cfg,
struct socket **sockp)
{
if (cfg->family == AF_INET)
return udp_sock_create4(net, cfg, sockp);
if (cfg->family == AF_INET6)
return udp_sock_create6(net, cfg, sockp);
return -EPFNOSUPPORT;
}
typedef int (*udp_tunnel_encap_rcv_t)(struct sock *sk, struct sk_buff *skb);
typedef int (*udp_tunnel_encap_err_lookup_t)(struct sock *sk,
struct sk_buff *skb);
typedef void (*udp_tunnel_encap_destroy_t)(struct sock *sk);
typedef struct sk_buff *(*udp_tunnel_gro_receive_t)(struct sock *sk,
struct list_head *head,
struct sk_buff *skb);
typedef int (*udp_tunnel_gro_complete_t)(struct sock *sk, struct sk_buff *skb,
int nhoff);
struct udp_tunnel_sock_cfg {
void *sk_user_data; /* user data used by encap_rcv call back */
/* Used for setting up udp_sock fields, see udp.h for details */
__u8 encap_type;
udp_tunnel_encap_rcv_t encap_rcv;
udp_tunnel_encap_err_lookup_t encap_err_lookup;
udp_tunnel_encap_destroy_t encap_destroy;
udp_tunnel_gro_receive_t gro_receive;
udp_tunnel_gro_complete_t gro_complete;
};
/* Setup the given (UDP) sock to receive UDP encapsulated packets */
void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
struct udp_tunnel_sock_cfg *sock_cfg);
/* -- List of parsable UDP tunnel types --
*
* Adding to this list will result in serious debate. The main issue is
* that this list is essentially a list of workarounds for either poorly
* designed tunnels, or poorly designed device offloads.
*
* The parsing supported via these types should really be used for Rx
* traffic only as the network stack will have already inserted offsets for
* the location of the headers in the skb. In addition any ports that are
* pushed should be kept within the namespace without leaking to other
* devices such as VFs or other ports on the same device.
*
* It is strongly encouraged to use CHECKSUM_COMPLETE for Rx to avoid the
* need to use this for Rx checksum offload. It should not be necessary to
* call this function to perform Tx offloads on outgoing traffic.
*/
enum udp_parsable_tunnel_type {
UDP_TUNNEL_TYPE_VXLAN, /* RFC 7348 */
UDP_TUNNEL_TYPE_GENEVE, /* draft-ietf-nvo3-geneve */
UDP_TUNNEL_TYPE_VXLAN_GPE, /* draft-ietf-nvo3-vxlan-gpe */
};
struct udp_tunnel_info {
unsigned short type;
sa_family_t sa_family;
__be16 port;
};
/* Notify network devices of offloadable types */
void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
unsigned short type);
void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
unsigned short type);
void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type);
void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type);
static inline void udp_tunnel_get_rx_info(struct net_device *dev)
{
ASSERT_RTNL();
call_netdevice_notifiers(NETDEV_UDP_TUNNEL_PUSH_INFO, dev);
}
static inline void udp_tunnel_drop_rx_info(struct net_device *dev)
{
ASSERT_RTNL();
call_netdevice_notifiers(NETDEV_UDP_TUNNEL_DROP_INFO, dev);
}
/* Transmit the skb using UDP encapsulation. */
void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
__be32 src, __be32 dst, __u8 tos, __u8 ttl,
__be16 df, __be16 src_port, __be16 dst_port,
bool xnet, bool nocheck);
#if IS_ENABLED(CONFIG_IPV6)
int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb,
struct net_device *dev, struct in6_addr *saddr,
struct in6_addr *daddr,
__u8 prio, __u8 ttl, __be32 label,
__be16 src_port, __be16 dst_port, bool nocheck);
#endif
void udp_tunnel_sock_release(struct socket *sock);
struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
__be16 flags, __be64 tunnel_id,
int md_size);
#ifdef CONFIG_INET
static inline int udp_tunnel_handle_offloads(struct sk_buff *skb, bool udp_csum)
{
int type = udp_csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
return iptunnel_handle_offloads(skb, type);
}
#endif
static inline void udp_tunnel_encap_enable(struct socket *sock)
{
struct udp_sock *up = udp_sk(sock->sk);
if (up->encap_enabled)
return;
up->encap_enabled = 1;
#if IS_ENABLED(CONFIG_IPV6)
if (sock->sk->sk_family == PF_INET6)
ipv6_stub->udpv6_encap_enable();
else
#endif
udp_encap_enable();
}
#endif