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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /net/l2tp/l2tp_eth.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/l2tp/l2tp_eth.c')
-rw-r--r--net/l2tp/l2tp_eth.c370
1 files changed, 370 insertions, 0 deletions
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
new file mode 100644
index 0000000000..f2ae03c404
--- /dev/null
+++ b/net/l2tp/l2tp_eth.c
@@ -0,0 +1,370 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* L2TPv3 ethernet pseudowire driver
+ *
+ * Copyright (c) 2008,2009,2010 Katalix Systems Ltd
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/socket.h>
+#include <linux/hash.h>
+#include <linux/l2tp.h>
+#include <linux/in.h>
+#include <linux/etherdevice.h>
+#include <linux/spinlock.h>
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/udp.h>
+#include <net/inet_common.h>
+#include <net/inet_hashtables.h>
+#include <net/tcp_states.h>
+#include <net/protocol.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/udp.h>
+
+#include "l2tp_core.h"
+
+/* Default device name. May be overridden by name specified by user */
+#define L2TP_ETH_DEV_NAME "l2tpeth%d"
+
+/* via netdev_priv() */
+struct l2tp_eth {
+ struct l2tp_session *session;
+ atomic_long_t tx_bytes;
+ atomic_long_t tx_packets;
+ atomic_long_t tx_dropped;
+ atomic_long_t rx_bytes;
+ atomic_long_t rx_packets;
+ atomic_long_t rx_errors;
+};
+
+/* via l2tp_session_priv() */
+struct l2tp_eth_sess {
+ struct net_device __rcu *dev;
+};
+
+static int l2tp_eth_dev_init(struct net_device *dev)
+{
+ eth_hw_addr_random(dev);
+ eth_broadcast_addr(dev->broadcast);
+ netdev_lockdep_set_classes(dev);
+
+ return 0;
+}
+
+static void l2tp_eth_dev_uninit(struct net_device *dev)
+{
+ struct l2tp_eth *priv = netdev_priv(dev);
+ struct l2tp_eth_sess *spriv;
+
+ spriv = l2tp_session_priv(priv->session);
+ RCU_INIT_POINTER(spriv->dev, NULL);
+ /* No need for synchronize_net() here. We're called by
+ * unregister_netdev*(), which does the synchronisation for us.
+ */
+}
+
+static netdev_tx_t l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct l2tp_eth *priv = netdev_priv(dev);
+ struct l2tp_session *session = priv->session;
+ unsigned int len = skb->len;
+ int ret = l2tp_xmit_skb(session, skb);
+
+ if (likely(ret == NET_XMIT_SUCCESS)) {
+ atomic_long_add(len, &priv->tx_bytes);
+ atomic_long_inc(&priv->tx_packets);
+ } else {
+ atomic_long_inc(&priv->tx_dropped);
+ }
+ return NETDEV_TX_OK;
+}
+
+static void l2tp_eth_get_stats64(struct net_device *dev,
+ struct rtnl_link_stats64 *stats)
+{
+ struct l2tp_eth *priv = netdev_priv(dev);
+
+ stats->tx_bytes = (unsigned long)atomic_long_read(&priv->tx_bytes);
+ stats->tx_packets = (unsigned long)atomic_long_read(&priv->tx_packets);
+ stats->tx_dropped = (unsigned long)atomic_long_read(&priv->tx_dropped);
+ stats->rx_bytes = (unsigned long)atomic_long_read(&priv->rx_bytes);
+ stats->rx_packets = (unsigned long)atomic_long_read(&priv->rx_packets);
+ stats->rx_errors = (unsigned long)atomic_long_read(&priv->rx_errors);
+}
+
+static const struct net_device_ops l2tp_eth_netdev_ops = {
+ .ndo_init = l2tp_eth_dev_init,
+ .ndo_uninit = l2tp_eth_dev_uninit,
+ .ndo_start_xmit = l2tp_eth_dev_xmit,
+ .ndo_get_stats64 = l2tp_eth_get_stats64,
+ .ndo_set_mac_address = eth_mac_addr,
+};
+
+static struct device_type l2tpeth_type = {
+ .name = "l2tpeth",
+};
+
+static void l2tp_eth_dev_setup(struct net_device *dev)
+{
+ SET_NETDEV_DEVTYPE(dev, &l2tpeth_type);
+ ether_setup(dev);
+ dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+ dev->features |= NETIF_F_LLTX;
+ dev->netdev_ops = &l2tp_eth_netdev_ops;
+ dev->needs_free_netdev = true;
+}
+
+static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len)
+{
+ struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
+ struct net_device *dev;
+ struct l2tp_eth *priv;
+
+ if (!pskb_may_pull(skb, ETH_HLEN))
+ goto error;
+
+ secpath_reset(skb);
+
+ /* checksums verified by L2TP */
+ skb->ip_summed = CHECKSUM_NONE;
+
+ skb_dst_drop(skb);
+ nf_reset_ct(skb);
+
+ rcu_read_lock();
+ dev = rcu_dereference(spriv->dev);
+ if (!dev)
+ goto error_rcu;
+
+ priv = netdev_priv(dev);
+ if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) {
+ atomic_long_inc(&priv->rx_packets);
+ atomic_long_add(data_len, &priv->rx_bytes);
+ } else {
+ atomic_long_inc(&priv->rx_errors);
+ }
+ rcu_read_unlock();
+
+ return;
+
+error_rcu:
+ rcu_read_unlock();
+error:
+ kfree_skb(skb);
+}
+
+static void l2tp_eth_delete(struct l2tp_session *session)
+{
+ struct l2tp_eth_sess *spriv;
+ struct net_device *dev;
+
+ if (session) {
+ spriv = l2tp_session_priv(session);
+
+ rtnl_lock();
+ dev = rtnl_dereference(spriv->dev);
+ if (dev) {
+ unregister_netdevice(dev);
+ rtnl_unlock();
+ module_put(THIS_MODULE);
+ } else {
+ rtnl_unlock();
+ }
+ }
+}
+
+static void l2tp_eth_show(struct seq_file *m, void *arg)
+{
+ struct l2tp_session *session = arg;
+ struct l2tp_eth_sess *spriv = l2tp_session_priv(session);
+ struct net_device *dev;
+
+ rcu_read_lock();
+ dev = rcu_dereference(spriv->dev);
+ if (!dev) {
+ rcu_read_unlock();
+ return;
+ }
+ dev_hold(dev);
+ rcu_read_unlock();
+
+ seq_printf(m, " interface %s\n", dev->name);
+
+ dev_put(dev);
+}
+
+static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel,
+ struct l2tp_session *session,
+ struct net_device *dev)
+{
+ unsigned int overhead = 0;
+ u32 l3_overhead = 0;
+ u32 mtu;
+
+ /* if the encap is UDP, account for UDP header size */
+ if (tunnel->encap == L2TP_ENCAPTYPE_UDP) {
+ overhead += sizeof(struct udphdr);
+ dev->needed_headroom += sizeof(struct udphdr);
+ }
+
+ lock_sock(tunnel->sock);
+ l3_overhead = kernel_sock_ip_overhead(tunnel->sock);
+ release_sock(tunnel->sock);
+
+ if (l3_overhead == 0) {
+ /* L3 Overhead couldn't be identified, this could be
+ * because tunnel->sock was NULL or the socket's
+ * address family was not IPv4 or IPv6,
+ * dev mtu stays at 1500.
+ */
+ return;
+ }
+ /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr
+ * UDP overhead, if any, was already factored in above.
+ */
+ overhead += session->hdr_len + ETH_HLEN + l3_overhead;
+
+ mtu = l2tp_tunnel_dst_mtu(tunnel) - overhead;
+ if (mtu < dev->min_mtu || mtu > dev->max_mtu)
+ dev->mtu = ETH_DATA_LEN - overhead;
+ else
+ dev->mtu = mtu;
+
+ dev->needed_headroom += session->hdr_len;
+}
+
+static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel,
+ u32 session_id, u32 peer_session_id,
+ struct l2tp_session_cfg *cfg)
+{
+ unsigned char name_assign_type;
+ struct net_device *dev;
+ char name[IFNAMSIZ];
+ struct l2tp_session *session;
+ struct l2tp_eth *priv;
+ struct l2tp_eth_sess *spriv;
+ int rc;
+
+ if (cfg->ifname) {
+ strscpy(name, cfg->ifname, IFNAMSIZ);
+ name_assign_type = NET_NAME_USER;
+ } else {
+ strcpy(name, L2TP_ETH_DEV_NAME);
+ name_assign_type = NET_NAME_ENUM;
+ }
+
+ session = l2tp_session_create(sizeof(*spriv), tunnel, session_id,
+ peer_session_id, cfg);
+ if (IS_ERR(session)) {
+ rc = PTR_ERR(session);
+ goto err;
+ }
+
+ dev = alloc_netdev(sizeof(*priv), name, name_assign_type,
+ l2tp_eth_dev_setup);
+ if (!dev) {
+ rc = -ENOMEM;
+ goto err_sess;
+ }
+
+ dev_net_set(dev, net);
+ dev->min_mtu = 0;
+ dev->max_mtu = ETH_MAX_MTU;
+ l2tp_eth_adjust_mtu(tunnel, session, dev);
+
+ priv = netdev_priv(dev);
+ priv->session = session;
+
+ session->recv_skb = l2tp_eth_dev_recv;
+ session->session_close = l2tp_eth_delete;
+ if (IS_ENABLED(CONFIG_L2TP_DEBUGFS))
+ session->show = l2tp_eth_show;
+
+ spriv = l2tp_session_priv(session);
+
+ l2tp_session_inc_refcount(session);
+
+ rtnl_lock();
+
+ /* Register both device and session while holding the rtnl lock. This
+ * ensures that l2tp_eth_delete() will see that there's a device to
+ * unregister, even if it happened to run before we assign spriv->dev.
+ */
+ rc = l2tp_session_register(session, tunnel);
+ if (rc < 0) {
+ rtnl_unlock();
+ goto err_sess_dev;
+ }
+
+ rc = register_netdevice(dev);
+ if (rc < 0) {
+ rtnl_unlock();
+ l2tp_session_delete(session);
+ l2tp_session_dec_refcount(session);
+ free_netdev(dev);
+
+ return rc;
+ }
+
+ strscpy(session->ifname, dev->name, IFNAMSIZ);
+ rcu_assign_pointer(spriv->dev, dev);
+
+ rtnl_unlock();
+
+ l2tp_session_dec_refcount(session);
+
+ __module_get(THIS_MODULE);
+
+ return 0;
+
+err_sess_dev:
+ l2tp_session_dec_refcount(session);
+ free_netdev(dev);
+err_sess:
+ kfree(session);
+err:
+ return rc;
+}
+
+static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = {
+ .session_create = l2tp_eth_create,
+ .session_delete = l2tp_session_delete,
+};
+
+static int __init l2tp_eth_init(void)
+{
+ int err = 0;
+
+ err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops);
+ if (err)
+ goto err;
+
+ pr_info("L2TP ethernet pseudowire support (L2TPv3)\n");
+
+ return 0;
+
+err:
+ return err;
+}
+
+static void __exit l2tp_eth_exit(void)
+{
+ l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH);
+}
+
+module_init(l2tp_eth_init);
+module_exit(l2tp_eth_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
+MODULE_DESCRIPTION("L2TP ethernet pseudowire driver");
+MODULE_VERSION("1.0");
+MODULE_ALIAS_L2TP_PWTYPE(5);