1 files changed, 301 insertions, 0 deletions
diff --git a/drivers/net/pfcp.c b/drivers/net/pfcp.c
new file mode 100644
index 000000000000..69434fd13f96
--- /dev/null
+++ b/drivers/net/pfcp.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PFCP according to 3GPP TS 29.244
+ *
+ * Copyright (C) 2022, Intel Corporation.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/rculist.h>
+#include <linux/skbuff.h>
+#include <linux/types.h>
+
+#include <net/udp.h>
+#include <net/udp_tunnel.h>
+#include <net/pfcp.h>
+
+struct pfcp_dev {
+	struct list_head	list;
+
+	struct socket		*sock;
+	struct net_device	*dev;
+	struct net		*net;
+
+	struct gro_cells	gro_cells;
+};
+
+static unsigned int pfcp_net_id __read_mostly;
+
+struct pfcp_net {
+	struct list_head	pfcp_dev_list;
+};
+
+static void
+pfcp_session_recv(struct pfcp_dev *pfcp, struct sk_buff *skb,
+		  struct pfcp_metadata *md)
+{
+	struct pfcphdr_session *unparsed = pfcp_hdr_session(skb);
+
+	md->seid = unparsed->seid;
+	md->type = PFCP_TYPE_SESSION;
+}
+
+static void
+pfcp_node_recv(struct pfcp_dev *pfcp, struct sk_buff *skb,
+	       struct pfcp_metadata *md)
+{
+	md->type = PFCP_TYPE_NODE;
+}
+
+static int pfcp_encap_recv(struct sock *sk, struct sk_buff *skb)
+{
+	IP_TUNNEL_DECLARE_FLAGS(flags) = { };
+	struct metadata_dst *tun_dst;
+	struct pfcp_metadata *md;
+	struct pfcphdr *unparsed;
+	struct pfcp_dev *pfcp;
+
+	if (unlikely(!pskb_may_pull(skb, PFCP_HLEN)))
+		goto drop;
+
+	pfcp = rcu_dereference_sk_user_data(sk);
+	if (unlikely(!pfcp))
+		goto drop;
+
+	unparsed = pfcp_hdr(skb);
+
+	ip_tunnel_flags_zero(flags);
+	tun_dst = udp_tun_rx_dst(skb, sk->sk_family, flags, 0,
+				 sizeof(*md));
+	if (unlikely(!tun_dst))
+		goto drop;
+
+	md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
+	if (unlikely(!md))
+		goto drop;
+
+	if (unparsed->flags & PFCP_SEID_FLAG)
+		pfcp_session_recv(pfcp, skb, md);
+	else
+		pfcp_node_recv(pfcp, skb, md);
+
+	__set_bit(IP_TUNNEL_PFCP_OPT_BIT, tun_dst->u.tun_info.key.tun_flags);
+	tun_dst->u.tun_info.options_len = sizeof(*md);
+
+	if (unlikely(iptunnel_pull_header(skb, PFCP_HLEN, skb->protocol,
+					  !net_eq(sock_net(sk),
+					  dev_net(pfcp->dev)))))
+		goto drop;
+
+	skb_dst_set(skb, (struct dst_entry *)tun_dst);
+
+	skb_reset_network_header(skb);
+	skb_reset_mac_header(skb);
+	skb->dev = pfcp->dev;
+
+	gro_cells_receive(&pfcp->gro_cells, skb);
+
+	return 0;
+drop:
+	kfree_skb(skb);
+	return 0;
+}
+
+static void pfcp_del_sock(struct pfcp_dev *pfcp)
+{
+	udp_tunnel_sock_release(pfcp->sock);
+	pfcp->sock = NULL;
+}
+
+static void pfcp_dev_uninit(struct net_device *dev)
+{
+	struct pfcp_dev *pfcp = netdev_priv(dev);
+
+	gro_cells_destroy(&pfcp->gro_cells);
+	pfcp_del_sock(pfcp);
+}
+
+static int pfcp_dev_init(struct net_device *dev)
+{
+	struct pfcp_dev *pfcp = netdev_priv(dev);
+
+	pfcp->dev = dev;
+
+	return gro_cells_init(&pfcp->gro_cells, dev);
+}
+
+static const struct net_device_ops pfcp_netdev_ops = {
+	.ndo_init		= pfcp_dev_init,
+	.ndo_uninit		= pfcp_dev_uninit,
+	.ndo_get_stats64	= dev_get_tstats64,
+};
+
+static const struct device_type pfcp_type = {
+	.name = "pfcp",
+};
+
+static void pfcp_link_setup(struct net_device *dev)
+{
+	dev->netdev_ops = &pfcp_netdev_ops;
+	dev->needs_free_netdev = true;
+	SET_NETDEV_DEVTYPE(dev, &pfcp_type);
+
+	dev->hard_header_len = 0;
+	dev->addr_len = 0;
+
+	dev->type = ARPHRD_NONE;
+	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+	dev->priv_flags |= IFF_NO_QUEUE;
+
+	netif_keep_dst(dev);
+}
+
+static struct socket *pfcp_create_sock(struct pfcp_dev *pfcp)
+{
+	struct udp_tunnel_sock_cfg tuncfg = {};
+	struct udp_port_cfg udp_conf = {
+		.local_ip.s_addr	= htonl(INADDR_ANY),
+		.family			= AF_INET,
+	};
+	struct net *net = pfcp->net;
+	struct socket *sock;
+	int err;
+
+	udp_conf.local_udp_port = htons(PFCP_PORT);
+
+	err = udp_sock_create(net, &udp_conf, &sock);
+	if (err)
+		return ERR_PTR(err);
+
+	tuncfg.sk_user_data = pfcp;
+	tuncfg.encap_rcv = pfcp_encap_recv;
+	tuncfg.encap_type = 1;
+
+	setup_udp_tunnel_sock(net, sock, &tuncfg);
+
+	return sock;
+}
+
+static int pfcp_add_sock(struct pfcp_dev *pfcp)
+{
+	pfcp->sock = pfcp_create_sock(pfcp);
+
+	return PTR_ERR_OR_ZERO(pfcp->sock);
+}
+
+static int pfcp_newlink(struct net *net, struct net_device *dev,
+			struct nlattr *tb[], struct nlattr *data[],
+			struct netlink_ext_ack *extack)
+{
+	struct pfcp_dev *pfcp = netdev_priv(dev);
+	struct pfcp_net *pn;
+	int err;
+
+	pfcp->net = net;
+
+	err = pfcp_add_sock(pfcp);
+	if (err) {
+		netdev_dbg(dev, "failed to add pfcp socket %d\n", err);
+		goto exit_err;
+	}
+
+	err = register_netdevice(dev);
+	if (err) {
+		netdev_dbg(dev, "failed to register pfcp netdev %d\n", err);
+		goto exit_del_pfcp_sock;
+	}
+
+	pn = net_generic(dev_net(dev), pfcp_net_id);
+	list_add_rcu(&pfcp->list, &pn->pfcp_dev_list);
+
+	netdev_dbg(dev, "registered new PFCP interface\n");
+
+	return 0;
+
+exit_del_pfcp_sock:
+	pfcp_del_sock(pfcp);
+exit_err:
+	pfcp->net = NULL;
+	return err;
+}
+
+static void pfcp_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct pfcp_dev *pfcp = netdev_priv(dev);
+
+	list_del_rcu(&pfcp->list);
+	unregister_netdevice_queue(dev, head);
+}
+
+static struct rtnl_link_ops pfcp_link_ops __read_mostly = {
+	.kind		= "pfcp",
+	.priv_size	= sizeof(struct pfcp_dev),
+	.setup		= pfcp_link_setup,
+	.newlink	= pfcp_newlink,
+	.dellink	= pfcp_dellink,
+};
+
+static int __net_init pfcp_net_init(struct net *net)
+{
+	struct pfcp_net *pn = net_generic(net, pfcp_net_id);
+
+	INIT_LIST_HEAD(&pn->pfcp_dev_list);
+	return 0;
+}
+
+static void __net_exit pfcp_net_exit(struct net *net)
+{
+	struct pfcp_net *pn = net_generic(net, pfcp_net_id);
+	struct pfcp_dev *pfcp;
+	LIST_HEAD(list);
+
+	rtnl_lock();
+	list_for_each_entry(pfcp, &pn->pfcp_dev_list, list)
+		pfcp_dellink(pfcp->dev, &list);
+
+	unregister_netdevice_many(&list);
+	rtnl_unlock();
+}
+
+static struct pernet_operations pfcp_net_ops = {
+	.init	= pfcp_net_init,
+	.exit	= pfcp_net_exit,
+	.id	= &pfcp_net_id,
+	.size	= sizeof(struct pfcp_net),
+};
+
+static int __init pfcp_init(void)
+{
+	int err;
+
+	err = register_pernet_subsys(&pfcp_net_ops);
+	if (err)
+		goto exit_err;
+
+	err = rtnl_link_register(&pfcp_link_ops);
+	if (err)
+		goto exit_unregister_subsys;
+	return 0;
+
+exit_unregister_subsys:
+	unregister_pernet_subsys(&pfcp_net_ops);
+exit_err:
+	pr_err("loading PFCP module failed: err %d\n", err);
+	return err;
+}
+late_initcall(pfcp_init);
+
+static void __exit pfcp_exit(void)
+{
+	rtnl_link_unregister(&pfcp_link_ops);
+	unregister_pernet_subsys(&pfcp_net_ops);
+
+	pr_info("PFCP module unloaded\n");
+}
+module_exit(pfcp_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Wojciech Drewek <[email protected]>");
+MODULE_DESCRIPTION("Interface driver for PFCP encapsulated traffic");
+MODULE_ALIAS_RTNL_LINK("pfcp");