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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /net/l2tp/l2tp_eth.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'net/l2tp/l2tp_eth.c')
-rw-r--r--net/l2tp/l2tp_eth.c352
1 files changed, 352 insertions, 0 deletions
diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c
new file mode 100644
index 000000000..a4956ef95
--- /dev/null
+++ b/net/l2tp/l2tp_eth.c
@@ -0,0 +1,352 @@
+// 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 <linux/string.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 <net/netdev_lock.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;
+};
+
+/* 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))
+ dev_dstats_tx_add(dev, len);
+ else
+ dev_dstats_tx_dropped(dev);
+
+ return NETDEV_TX_OK;
+}
+
+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_set_mac_address = eth_mac_addr,
+};
+
+static const 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->lltx = true;
+ dev->netdev_ops = &l2tp_eth_netdev_ops;
+ dev->needs_free_netdev = true;
+ dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
+}
+
+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;
+
+ if (!pskb_may_pull(skb, ETH_HLEN))
+ goto error;
+
+ secpath_reset(skb);
+
+ /* checksums verified by L2TP */
+ skb->ip_summed = CHECKSUM_NONE;
+
+ /* drop outer flow-hash */
+ skb_clear_hash(skb);
+
+ skb_dst_drop(skb);
+ nf_reset_ct(skb);
+
+ rcu_read_lock();
+ dev = rcu_dereference(spriv->dev);
+ if (!dev)
+ goto error_rcu;
+
+ if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS)
+ dev_dstats_rx_add(dev, data_len);
+ else
+ DEV_STATS_INC(dev, 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);
+ name_assign_type = NET_NAME_USER;
+ } else {
+ strscpy(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);
+
+ refcount_inc(&session->ref_count);
+
+ 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_put(session);
+ free_netdev(dev);
+
+ return rc;
+ }
+
+ strscpy(session->ifname, dev->name, IFNAMSIZ);
+ rcu_assign_pointer(spriv->dev, dev);
+
+ rtnl_unlock();
+
+ l2tp_session_put(session);
+
+ __module_get(THIS_MODULE);
+
+ return 0;
+
+err_sess_dev:
+ l2tp_session_put(session);
+ free_netdev(dev);
+err_sess:
+ l2tp_session_put(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);