1 files changed, 225 insertions, 0 deletions
diff --git a/net/ipv4/udp_tunnel_core.c b/net/ipv4/udp_tunnel_core.c
new file mode 100644
index 000000000..d70f683d3
--- /dev/null
+++ b/net/ipv4/udp_tunnel_core.c
@@ -0,0 +1,225 @@
+// 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);
+	synchronize_rcu();
+	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");