udp_tunnel: add central NIC RX port offload infrastructure

Cater to devices which:
 (a) may want to sleep in the callbacks;
 (b) only have IPv4 support;
 (c) need all the programming to happen while the netdev is up.

Drivers attach UDP tunnel offload info struct to their netdevs,
where they declare how many UDP ports of various tunnel types
they support. Core takes care of tracking which ports to offload.

Use a fixed-size array since this matches what almost all drivers
do, and avoids a complexity and uncertainty around memory allocations
in an atomic context.

Make sure that tunnel drivers don't try to replay the ports when
new NIC netdev is registered. Automatic replays would mess up
reference counting, and will be removed completely once all drivers
are converted.

v4:
 - use a #define NULL to avoid build issues with CONFIG_INET=n.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 0 insertions, 224 deletions

diff --git a/net/ipv4/udp_tunnel.c b/net/ipv4/udp_tunnel.c
deleted file mode 100644
index 3eecba0874aa..000000000000
--- a/net/ipv4/udp_tunnel.c
+++ /dev/null
@@ -1,224 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-#include <linux/module.h>
-#include <linux/errno.h>
-#include <linux/socket.h>
-#include <linux/udp.h>
-#include <linux/types.h>
-#include <linux/kernel.h>
-#include <net/dst_metadata.h>
-#include <net/net_namespace.h>
-#include <net/udp.h>
-#include <net/udp_tunnel.h>
-
-int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
-		     struct socket **sockp)
-{
-	int err;
-	struct socket *sock = NULL;
-	struct sockaddr_in udp_addr;
-
-	err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 0, &sock);
-	if (err < 0)
-		goto error;
-
-	if (cfg->bind_ifindex) {
-		err = sock_bindtoindex(sock->sk, cfg->bind_ifindex, true);
-		if (err < 0)
-			goto error;
-	}
-
-	udp_addr.sin_family = AF_INET;
-	udp_addr.sin_addr = cfg->local_ip;
-	udp_addr.sin_port = cfg->local_udp_port;
-	err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
-			  sizeof(udp_addr));
-	if (err < 0)
-		goto error;
-
-	if (cfg->peer_udp_port) {
-		udp_addr.sin_family = AF_INET;
-		udp_addr.sin_addr = cfg->peer_ip;
-		udp_addr.sin_port = cfg->peer_udp_port;
-		err = kernel_connect(sock, (struct sockaddr *)&udp_addr,
-				     sizeof(udp_addr), 0);
-		if (err < 0)
-			goto error;
-	}
-
-	sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
-
-	*sockp = sock;
-	return 0;
-
-error:
-	if (sock) {
-		kernel_sock_shutdown(sock, SHUT_RDWR);
-		sock_release(sock);
-	}
-	*sockp = NULL;
-	return err;
-}
-EXPORT_SYMBOL(udp_sock_create4);
-
-void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
-			   struct udp_tunnel_sock_cfg *cfg)
-{
-	struct sock *sk = sock->sk;
-
-	/* Disable multicast loopback */
-	inet_sk(sk)->mc_loop = 0;
-
-	/* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
-	inet_inc_convert_csum(sk);
-
-	rcu_assign_sk_user_data(sk, cfg->sk_user_data);
-
-	udp_sk(sk)->encap_type = cfg->encap_type;
-	udp_sk(sk)->encap_rcv = cfg->encap_rcv;
-	udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup;
-	udp_sk(sk)->encap_destroy = cfg->encap_destroy;
-	udp_sk(sk)->gro_receive = cfg->gro_receive;
-	udp_sk(sk)->gro_complete = cfg->gro_complete;
-
-	udp_tunnel_encap_enable(sock);
-}
-EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
-
-void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
-			     unsigned short type)
-{
-	struct sock *sk = sock->sk;
-	struct udp_tunnel_info ti;
-
-	if (!dev->netdev_ops->ndo_udp_tunnel_add ||
-	    !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
-		return;
-
-	ti.type = type;
-	ti.sa_family = sk->sk_family;
-	ti.port = inet_sk(sk)->inet_sport;
-
-	dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
-}
-EXPORT_SYMBOL_GPL(udp_tunnel_push_rx_port);
-
-void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
-			     unsigned short type)
-{
-	struct sock *sk = sock->sk;
-	struct udp_tunnel_info ti;
-
-	if (!dev->netdev_ops->ndo_udp_tunnel_del ||
-	    !(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
-		return;
-
-	ti.type = type;
-	ti.sa_family = sk->sk_family;
-	ti.port = inet_sk(sk)->inet_sport;
-
-	dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
-}
-EXPORT_SYMBOL_GPL(udp_tunnel_drop_rx_port);
-
-/* Notify netdevs that UDP port started listening */
-void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type)
-{
-	struct sock *sk = sock->sk;
-	struct net *net = sock_net(sk);
-	struct udp_tunnel_info ti;
-	struct net_device *dev;
-
-	ti.type = type;
-	ti.sa_family = sk->sk_family;
-	ti.port = inet_sk(sk)->inet_sport;
-
-	rcu_read_lock();
-	for_each_netdev_rcu(net, dev) {
-		if (!dev->netdev_ops->ndo_udp_tunnel_add)
-			continue;
-		if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
-			continue;
-		dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
-	}
-	rcu_read_unlock();
-}
-EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port);
-
-/* Notify netdevs that UDP port is no more listening */
-void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
-{
-	struct sock *sk = sock->sk;
-	struct net *net = sock_net(sk);
-	struct udp_tunnel_info ti;
-	struct net_device *dev;
-
-	ti.type = type;
-	ti.sa_family = sk->sk_family;
-	ti.port = inet_sk(sk)->inet_sport;
-
-	rcu_read_lock();
-	for_each_netdev_rcu(net, dev) {
-		if (!dev->netdev_ops->ndo_udp_tunnel_del)
-			continue;
-		if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
-			continue;
-		dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
-	}
-	rcu_read_unlock();
-}
-EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port);
-
-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)
-{
-	struct udphdr *uh;
-
-	__skb_push(skb, sizeof(*uh));
-	skb_reset_transport_header(skb);
-	uh = udp_hdr(skb);
-
-	uh->dest = dst_port;
-	uh->source = src_port;
-	uh->len = htons(skb->len);
-
-	memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-
-	udp_set_csum(nocheck, skb, src, dst, skb->len);
-
-	iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, xnet);
-}
-EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
-
-void udp_tunnel_sock_release(struct socket *sock)
-{
-	rcu_assign_sk_user_data(sock->sk, NULL);
-	kernel_sock_shutdown(sock, SHUT_RDWR);
-	sock_release(sock);
-}
-EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
-
-struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb,  unsigned short family,
-				    __be16 flags, __be64 tunnel_id, int md_size)
-{
-	struct metadata_dst *tun_dst;
-	struct ip_tunnel_info *info;
-
-	if (family == AF_INET)
-		tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id, md_size);
-	else
-		tun_dst = ipv6_tun_rx_dst(skb, flags, tunnel_id, md_size);
-	if (!tun_dst)
-		return NULL;
-
-	info = &tun_dst->u.tun_info;
-	info->key.tp_src = udp_hdr(skb)->source;
-	info->key.tp_dst = udp_hdr(skb)->dest;
-	if (udp_hdr(skb)->check)
-		info->key.tun_flags |= TUNNEL_CSUM;
-	return tun_dst;
-}
-EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
-
-MODULE_LICENSE("GPL");