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linux/include/net/udp_tunnel.h
Alexander Lobakin 5832c4a77d ip_tunnel: convert __be16 tunnel flags to bitmaps 
Historically, tunnel flags like TUNNEL_CSUM or TUNNEL_ERSPAN_OPT
have been defined as __be16. Now all of those 16 bits are occupied
and there's no more free space for new flags.
It can't be simply switched to a bigger container with no
adjustments to the values, since it's an explicit Endian storage,
and on LE systems (__be16)0x0001 equals to
(__be64)0x0001000000000000.
We could probably define new 64-bit flags depending on the
Endianness, i.e. (__be64)0x0001 on BE and (__be64)0x00010000... on
LE, but that would introduce an Endianness dependency and spawn a
ton of Sparse warnings. To mitigate them, all of those places which
were adjusted with this change would be touched anyway, so why not
define stuff properly if there's no choice.

Define IP_TUNNEL_*_BIT counterparts as a bit number instead of the
value already coded and a fistful of <16 <-> bitmap> converters and
helpers. The two flags which have a different bit position are
SIT_ISATAP_BIT and VTI_ISVTI_BIT, as they were defined not as
__cpu_to_be16(), but as (__force __be16), i.e. had different
positions on LE and BE. Now they both have strongly defined places.
Change all __be16 fields which were used to store those flags, to
IP_TUNNEL_DECLARE_FLAGS() -> DECLARE_BITMAP(__IP_TUNNEL_FLAG_NUM) ->
unsigned long[1] for now, and replace all TUNNEL_* occurrences to
their bitmap counterparts. Use the converters in the places which talk
to the userspace, hardware (NFP) or other hosts (GRE header). The rest
must explicitly use the new flags only. This must be done at once,
otherwise there will be too many conversions throughout the code in
the intermediate commits.
Finally, disable the old __be16 flags for use in the kernel code
(except for the two 'irregular' flags mentioned above), to prevent
any accidental (mis)use of them. For the userspace, nothing is
changed, only additions were made.

Most noticeable bloat-o-meter difference (.text):

vmlinux:	307/-1 (306)
gre.ko:		62/0 (62)
ip_gre.ko:	941/-217 (724)	[*]
ip_tunnel.ko:	390/-900 (-510)	[**]
ip_vti.ko:	138/0 (138)
ip6_gre.ko:	534/-18 (516)	[*]
ip6_tunnel.ko:	118/-10 (108)

[*] gre_flags_to_tnl_flags() grew, but still is inlined
[**] ip_tunnel_find() got uninlined, hence such decrease

The average code size increase in non-extreme case is 100-200 bytes
per module, mostly due to sizeof(long) > sizeof(__be16), as
%__IP_TUNNEL_FLAG_NUM is less than %BITS_PER_LONG and the compilers
are able to expand the majority of bitmap_*() calls here into direct
operations on scalars.

Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-01 10:49:28 +01:00

397 lines
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/* 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/ipv6_stubs.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;
int bind_ifindex;
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_err_rcv_t)(struct sock *sk,
struct sk_buff *skb, int err,
__be16 port, u32 info, u8 *payload);
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_err_rcv_t encap_err_rcv;
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 = BIT(0), /* RFC 7348 */
UDP_TUNNEL_TYPE_GENEVE = BIT(1), /* draft-ietf-nvo3-geneve */
UDP_TUNNEL_TYPE_VXLAN_GPE = BIT(2), /* draft-ietf-nvo3-vxlan-gpe */
};
struct udp_tunnel_info {
unsigned short type;
sa_family_t sa_family;
__be16 port;
u8 hw_priv;
};
/* 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();
if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
return;
call_netdevice_notifiers(NETDEV_UDP_TUNNEL_PUSH_INFO, dev);
}
static inline void udp_tunnel_drop_rx_info(struct net_device *dev)
{
ASSERT_RTNL();
if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
return;
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);
int udp_tunnel6_xmit_skb(struct dst_entry *dst, struct sock *sk,
struct sk_buff *skb,
struct net_device *dev,
const struct in6_addr *saddr,
const struct in6_addr *daddr,
__u8 prio, __u8 ttl, __be32 label,
__be16 src_port, __be16 dst_port, bool nocheck);
void udp_tunnel_sock_release(struct socket *sock);
struct rtable *udp_tunnel_dst_lookup(struct sk_buff *skb,
struct net_device *dev,
struct net *net, int oif,
__be32 *saddr,
const struct ip_tunnel_key *key,
__be16 sport, __be16 dport, u8 tos,
struct dst_cache *dst_cache);
struct dst_entry *udp_tunnel6_dst_lookup(struct sk_buff *skb,
struct net_device *dev,
struct net *net,
struct socket *sock, int oif,
struct in6_addr *saddr,
const struct ip_tunnel_key *key,
__be16 sport, __be16 dport, u8 dsfield,
struct dst_cache *dst_cache);
struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
const unsigned long *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 sock *sk)
{
if (udp_test_and_set_bit(ENCAP_ENABLED, sk))
return;
#if IS_ENABLED(CONFIG_IPV6)
if (READ_ONCE(sk->sk_family) == PF_INET6)
ipv6_stub->udpv6_encap_enable();
#endif
udp_encap_enable();
}
#define UDP_TUNNEL_NIC_MAX_TABLES 4
enum udp_tunnel_nic_info_flags {
/* Device callbacks may sleep */
UDP_TUNNEL_NIC_INFO_MAY_SLEEP = BIT(0),
/* Device only supports offloads when it's open, all ports
* will be removed before close and re-added after open.
*/
UDP_TUNNEL_NIC_INFO_OPEN_ONLY = BIT(1),
/* Device supports only IPv4 tunnels */
UDP_TUNNEL_NIC_INFO_IPV4_ONLY = BIT(2),
/* Device has hard-coded the IANA VXLAN port (4789) as VXLAN.
* This port must not be counted towards n_entries of any table.
* Driver will not receive any callback associated with port 4789.
*/
UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN = BIT(3),
};
struct udp_tunnel_nic;
#define UDP_TUNNEL_NIC_MAX_SHARING_DEVICES (U16_MAX / 2)
struct udp_tunnel_nic_shared {
struct udp_tunnel_nic *udp_tunnel_nic_info;
struct list_head devices;
};
struct udp_tunnel_nic_shared_node {
struct net_device *dev;
struct list_head list;
};
/**
* struct udp_tunnel_nic_info - driver UDP tunnel offload information
* @set_port: callback for adding a new port
* @unset_port: callback for removing a port
* @sync_table: callback for syncing the entire port table at once
* @shared: reference to device global state (optional)
* @flags: device flags from enum udp_tunnel_nic_info_flags
* @tables: UDP port tables this device has
* @tables.n_entries: number of entries in this table
* @tables.tunnel_types: types of tunnels this table accepts
*
* Drivers are expected to provide either @set_port and @unset_port callbacks
* or the @sync_table callback. Callbacks are invoked with rtnl lock held.
*
* Devices which (misguidedly) share the UDP tunnel port table across multiple
* netdevs should allocate an instance of struct udp_tunnel_nic_shared and
* point @shared at it.
* There must never be more than %UDP_TUNNEL_NIC_MAX_SHARING_DEVICES devices
* sharing a table.
*
* Known limitations:
* - UDP tunnel port notifications are fundamentally best-effort -
* it is likely the driver will both see skbs which use a UDP tunnel port,
* while not being a tunneled skb, and tunnel skbs from other ports -
* drivers should only use these ports for non-critical RX-side offloads,
* e.g. the checksum offload;
* - none of the devices care about the socket family at present, so we don't
* track it. Please extend this code if you care.
*/
struct udp_tunnel_nic_info {
/* one-by-one */
int (*set_port)(struct net_device *dev,
unsigned int table, unsigned int entry,
struct udp_tunnel_info *ti);
int (*unset_port)(struct net_device *dev,
unsigned int table, unsigned int entry,
struct udp_tunnel_info *ti);
/* all at once */
int (*sync_table)(struct net_device *dev, unsigned int table);
struct udp_tunnel_nic_shared *shared;
unsigned int flags;
struct udp_tunnel_nic_table_info {
unsigned int n_entries;
unsigned int tunnel_types;
} tables[UDP_TUNNEL_NIC_MAX_TABLES];
};
/* UDP tunnel module dependencies
*
* Tunnel drivers are expected to have a hard dependency on the udp_tunnel
* module. NIC drivers are not, they just attach their
* struct udp_tunnel_nic_info to the netdev and wait for callbacks to come.
* Loading a tunnel driver will cause the udp_tunnel module to be loaded
* and only then will all the required state structures be allocated.
* Since we want a weak dependency from the drivers and the core to udp_tunnel
* we call things through the following stubs.
*/
struct udp_tunnel_nic_ops {
void (*get_port)(struct net_device *dev, unsigned int table,
unsigned int idx, struct udp_tunnel_info *ti);
void (*set_port_priv)(struct net_device *dev, unsigned int table,
unsigned int idx, u8 priv);
void (*add_port)(struct net_device *dev, struct udp_tunnel_info *ti);
void (*del_port)(struct net_device *dev, struct udp_tunnel_info *ti);
void (*reset_ntf)(struct net_device *dev);
size_t (*dump_size)(struct net_device *dev, unsigned int table);
int (*dump_write)(struct net_device *dev, unsigned int table,
struct sk_buff *skb);
};
#ifdef CONFIG_INET
extern const struct udp_tunnel_nic_ops *udp_tunnel_nic_ops;
#else
#define udp_tunnel_nic_ops ((struct udp_tunnel_nic_ops *)NULL)
#endif
static inline void
udp_tunnel_nic_get_port(struct net_device *dev, unsigned int table,
unsigned int idx, struct udp_tunnel_info *ti)
{
/* This helper is used from .sync_table, we indicate empty entries
* by zero'ed @ti. Drivers which need to know the details of a port
* when it gets deleted should use the .set_port / .unset_port
* callbacks.
* Zero out here, otherwise !CONFIG_INET causes uninitilized warnings.
*/
memset(ti, 0, sizeof(*ti));
if (udp_tunnel_nic_ops)
udp_tunnel_nic_ops->get_port(dev, table, idx, ti);
}
static inline void
udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
unsigned int idx, u8 priv)
{
if (udp_tunnel_nic_ops)
udp_tunnel_nic_ops->set_port_priv(dev, table, idx, priv);
}
static inline void
udp_tunnel_nic_add_port(struct net_device *dev, struct udp_tunnel_info *ti)
{
if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
return;
if (udp_tunnel_nic_ops)
udp_tunnel_nic_ops->add_port(dev, ti);
}
static inline void
udp_tunnel_nic_del_port(struct net_device *dev, struct udp_tunnel_info *ti)
{
if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
return;
if (udp_tunnel_nic_ops)
udp_tunnel_nic_ops->del_port(dev, ti);
}
/**
* udp_tunnel_nic_reset_ntf() - device-originating reset notification
* @dev: network interface device structure
*
* Called by the driver to inform the core that the entire UDP tunnel port
* state has been lost, usually due to device reset. Core will assume device
* forgot all the ports and issue .set_port and .sync_table callbacks as
* necessary.
*
* This function must be called with rtnl lock held, and will issue all
* the callbacks before returning.
*/
static inline void udp_tunnel_nic_reset_ntf(struct net_device *dev)
{
if (udp_tunnel_nic_ops)
udp_tunnel_nic_ops->reset_ntf(dev);
}
static inline size_t
udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
{
if (!udp_tunnel_nic_ops)
return 0;
return udp_tunnel_nic_ops->dump_size(dev, table);
}
static inline int
udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
struct sk_buff *skb)
{
if (!udp_tunnel_nic_ops)
return 0;
return udp_tunnel_nic_ops->dump_write(dev, table, skb);
}
#endif
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