summaryrefslogtreecommitdiffstats
path: root/drivers/net/can/vxcan.c
diff options
context:
space:
mode:
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 /drivers/net/can/vxcan.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 'drivers/net/can/vxcan.c')
-rw-r--r--drivers/net/can/vxcan.c345
1 files changed, 345 insertions, 0 deletions
diff --git a/drivers/net/can/vxcan.c b/drivers/net/can/vxcan.c
new file mode 100644
index 000000000..9e2e25d02
--- /dev/null
+++ b/drivers/net/can/vxcan.c
@@ -0,0 +1,345 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * vxcan.c - Virtual CAN Tunnel for cross namespace communication
+ *
+ * This code is derived from drivers/net/can/vcan.c for the virtual CAN
+ * specific parts and from drivers/net/veth.c to implement the netlink API
+ * for network interface pairs in a common and established way.
+ *
+ * Copyright (c) 2017 Oliver Hartkopp <socketcan@hartkopp.net>
+ */
+
+#include <linux/ethtool.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/can.h>
+#include <linux/can/dev.h>
+#include <linux/can/skb.h>
+#include <linux/can/vxcan.h>
+#include <linux/can/can-ml.h>
+#include <linux/slab.h>
+#include <net/can.h>
+#include <net/rtnetlink.h>
+
+#define DRV_NAME "vxcan"
+
+MODULE_DESCRIPTION("Virtual CAN Tunnel");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Oliver Hartkopp <socketcan@hartkopp.net>");
+MODULE_ALIAS_RTNL_LINK(DRV_NAME);
+
+struct vxcan_priv {
+ struct net_device __rcu *peer;
+ netdevice_tracker peer_tracker;
+};
+
+static netdev_tx_t vxcan_xmit(struct sk_buff *oskb, struct net_device *dev)
+{
+ struct vxcan_priv *priv = netdev_priv(dev);
+ struct net_device *peer;
+ struct net_device_stats *peerstats, *srcstats = &dev->stats;
+ struct can_skb_ext *csx;
+ struct sk_buff *skb;
+ unsigned int len;
+
+ if (can_dropped_invalid_skb(dev, oskb))
+ return NETDEV_TX_OK;
+
+ rcu_read_lock();
+ peer = rcu_dereference(priv->peer);
+ if (unlikely(!peer)) {
+ kfree_skb(oskb);
+ dev->stats.tx_dropped++;
+ goto out_unlock;
+ }
+
+ skb_tx_timestamp(oskb);
+
+ skb = skb_clone(oskb, GFP_ATOMIC);
+ if (skb) {
+ consume_skb(oskb);
+ } else {
+ kfree_skb(oskb);
+ goto out_unlock;
+ }
+
+ /* the cloned skb points to the skb extension of the already cloned
+ * oskb with an increased refcount. skb_ext_add() creates a copy to
+ * separate the skb extension data which is needed to start with a
+ * fresh can_gw_hops counter in the other namespace.
+ */
+ csx = skb_ext_add(skb, SKB_EXT_CAN);
+ if (!csx) {
+ kfree_skb(skb);
+ goto out_unlock;
+ }
+
+ /* reset CAN GW hop counter */
+ csx->can_gw_hops = 0;
+ skb->pkt_type = PACKET_BROADCAST;
+ skb->dev = peer;
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+
+ len = can_skb_get_data_len(skb);
+ if (netif_rx(skb) == NET_RX_SUCCESS) {
+ srcstats->tx_packets++;
+ srcstats->tx_bytes += len;
+ peerstats = &peer->stats;
+ peerstats->rx_packets++;
+ peerstats->rx_bytes += len;
+ }
+
+out_unlock:
+ rcu_read_unlock();
+ return NETDEV_TX_OK;
+}
+
+
+static int vxcan_open(struct net_device *dev)
+{
+ struct vxcan_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
+
+ if (!peer)
+ return -ENOTCONN;
+
+ if (peer->flags & IFF_UP) {
+ netif_carrier_on(dev);
+ netif_carrier_on(peer);
+ }
+ return 0;
+}
+
+static int vxcan_close(struct net_device *dev)
+{
+ struct vxcan_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
+
+ netif_carrier_off(dev);
+ if (peer)
+ netif_carrier_off(peer);
+
+ return 0;
+}
+
+static int vxcan_get_iflink(const struct net_device *dev)
+{
+ struct vxcan_priv *priv = netdev_priv(dev);
+ struct net_device *peer;
+ int iflink;
+
+ rcu_read_lock();
+ peer = rcu_dereference(priv->peer);
+ iflink = peer ? READ_ONCE(peer->ifindex) : 0;
+ rcu_read_unlock();
+
+ return iflink;
+}
+
+static void vxcan_set_cap_info(struct net_device *dev)
+{
+ u32 can_cap = CAN_CAP_CC;
+
+ if (dev->mtu > CAN_MTU)
+ can_cap |= CAN_CAP_FD;
+
+ if (dev->mtu >= CANXL_MIN_MTU)
+ can_cap |= CAN_CAP_XL;
+
+ can_set_cap(dev, can_cap);
+}
+
+static int vxcan_change_mtu(struct net_device *dev, int new_mtu)
+{
+ /* Do not allow changing the MTU while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+
+ if (new_mtu != CAN_MTU && new_mtu != CANFD_MTU &&
+ !can_is_canxl_dev_mtu(new_mtu))
+ return -EINVAL;
+
+ WRITE_ONCE(dev->mtu, new_mtu);
+ vxcan_set_cap_info(dev);
+ return 0;
+}
+
+static const struct net_device_ops vxcan_netdev_ops = {
+ .ndo_open = vxcan_open,
+ .ndo_stop = vxcan_close,
+ .ndo_start_xmit = vxcan_xmit,
+ .ndo_get_iflink = vxcan_get_iflink,
+ .ndo_change_mtu = vxcan_change_mtu,
+};
+
+static const struct ethtool_ops vxcan_ethtool_ops = {
+ .get_ts_info = ethtool_op_get_ts_info,
+};
+
+static void vxcan_setup(struct net_device *dev)
+{
+ struct can_ml_priv *can_ml;
+
+ dev->type = ARPHRD_CAN;
+ dev->mtu = CANXL_MTU;
+ dev->hard_header_len = 0;
+ dev->addr_len = 0;
+ dev->tx_queue_len = 0;
+ dev->flags = IFF_NOARP;
+ dev->netdev_ops = &vxcan_netdev_ops;
+ dev->ethtool_ops = &vxcan_ethtool_ops;
+ dev->needs_free_netdev = true;
+
+ can_ml = netdev_priv(dev) + ALIGN(sizeof(struct vxcan_priv), NETDEV_ALIGN);
+ can_set_ml_priv(dev, can_ml);
+ vxcan_set_cap_info(dev);
+}
+
+/* forward declaration for rtnl_create_link() */
+static struct rtnl_link_ops vxcan_link_ops;
+
+static int vxcan_newlink(struct net_device *dev,
+ struct rtnl_newlink_params *params,
+ struct netlink_ext_ack *extack)
+{
+ struct net *peer_net = rtnl_newlink_peer_net(params);
+ struct nlattr **data = params->data;
+ struct nlattr **tb = params->tb;
+ struct vxcan_priv *priv;
+ struct net_device *peer;
+
+ struct nlattr *peer_tb[IFLA_MAX + 1], **tbp = tb;
+ char ifname[IFNAMSIZ];
+ unsigned char name_assign_type;
+ struct ifinfomsg *ifmp = NULL;
+ int err;
+
+ /* register peer device */
+ if (data && data[VXCAN_INFO_PEER]) {
+ struct nlattr *nla_peer = data[VXCAN_INFO_PEER];
+
+ ifmp = nla_data(nla_peer);
+ rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
+ tbp = peer_tb;
+ }
+
+ if (ifmp && tbp[IFLA_IFNAME]) {
+ nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
+ name_assign_type = NET_NAME_USER;
+ } else {
+ snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
+ name_assign_type = NET_NAME_ENUM;
+ }
+
+ peer = rtnl_create_link(peer_net, ifname, name_assign_type,
+ &vxcan_link_ops, tbp, extack);
+ if (IS_ERR(peer))
+ return PTR_ERR(peer);
+
+ if (ifmp && dev->ifindex)
+ peer->ifindex = ifmp->ifi_index;
+
+ err = register_netdevice(peer);
+ if (err < 0) {
+ free_netdev(peer);
+ return err;
+ }
+
+ netif_carrier_off(peer);
+
+ err = rtnl_configure_link(peer, ifmp, 0, NULL);
+ if (err < 0)
+ goto unregister_network_device;
+
+ /* register first device */
+ if (tb[IFLA_IFNAME])
+ nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
+ else
+ snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
+
+ err = register_netdevice(dev);
+ if (err < 0)
+ goto unregister_network_device;
+
+ netif_carrier_off(dev);
+
+ /* cross link the device pair */
+ priv = netdev_priv(dev);
+ rcu_assign_pointer(priv->peer, peer);
+ netdev_hold(peer, &priv->peer_tracker, GFP_KERNEL);
+
+ priv = netdev_priv(peer);
+ rcu_assign_pointer(priv->peer, dev);
+ netdev_hold(dev, &priv->peer_tracker, GFP_KERNEL);
+
+ return 0;
+
+unregister_network_device:
+ unregister_netdevice(peer);
+ return err;
+}
+
+static void vxcan_dellink(struct net_device *dev, struct list_head *head)
+{
+ netdevice_tracker *peer_tracker;
+ struct vxcan_priv *priv;
+ struct net_device *peer;
+
+ priv = netdev_priv(dev);
+ peer_tracker = &priv->peer_tracker;
+ peer = unrcu_pointer(xchg(&priv->peer, NULL));
+ if (!peer)
+ return;
+
+ unregister_netdevice_queue(dev, head);
+
+ priv = netdev_priv(peer);
+ dev = unrcu_pointer(xchg(&priv->peer, NULL));
+ if (dev)
+ unregister_netdevice_queue_net(dev_net(dev), peer, head);
+
+ netdev_put(peer, peer_tracker);
+ netdev_put(dev, &priv->peer_tracker);
+}
+
+static const struct nla_policy vxcan_policy[VXCAN_INFO_MAX + 1] = {
+ [VXCAN_INFO_PEER] = { .len = sizeof(struct ifinfomsg) },
+};
+
+static struct net *vxcan_get_link_net(const struct net_device *dev)
+{
+ struct vxcan_priv *priv = netdev_priv(dev);
+ struct net_device *peer = rtnl_dereference(priv->peer);
+
+ return peer ? dev_net(peer) : dev_net(dev);
+}
+
+static struct rtnl_link_ops vxcan_link_ops = {
+ .kind = DRV_NAME,
+ .priv_size = ALIGN(sizeof(struct vxcan_priv), NETDEV_ALIGN) + sizeof(struct can_ml_priv),
+ .setup = vxcan_setup,
+ .newlink = vxcan_newlink,
+ .dellink = vxcan_dellink,
+ .policy = vxcan_policy,
+ .peer_type = VXCAN_INFO_PEER,
+ .maxtype = VXCAN_INFO_MAX,
+ .get_link_net = vxcan_get_link_net,
+};
+
+static __init int vxcan_init(void)
+{
+ pr_info("vxcan: Virtual CAN Tunnel driver\n");
+
+ return rtnl_link_register(&vxcan_link_ops);
+}
+
+static __exit void vxcan_exit(void)
+{
+ rtnl_link_unregister(&vxcan_link_ops);
+}
+
+module_init(vxcan_init);
+module_exit(vxcan_exit);