From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- drivers/net/can/vxcan.c | 322 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 322 insertions(+) create mode 100644 drivers/net/can/vxcan.c (limited to 'drivers/net/can/vxcan.c') diff --git a/drivers/net/can/vxcan.c b/drivers/net/can/vxcan.c new file mode 100644 index 0000000000..98c669ad51 --- /dev/null +++ b/drivers/net/can/vxcan.c @@ -0,0 +1,322 @@ +// 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 + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "vxcan" + +MODULE_DESCRIPTION("Virtual CAN Tunnel"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Oliver Hartkopp "); +MODULE_ALIAS_RTNL_LINK(DRV_NAME); + +struct vxcan_priv { + struct net_device __rcu *peer; +}; + +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 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; + } + + /* reset CAN GW hop counter */ + skb->csum_start = 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 ? peer->ifindex : 0; + rcu_read_unlock(); + + return iflink; +} + +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; + + dev->mtu = new_mtu; + 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 = CANFD_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); +} + +/* forward declaration for rtnl_create_link() */ +static struct rtnl_link_ops vxcan_link_ops; + +static int vxcan_newlink(struct net *net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +{ + struct vxcan_priv *priv; + struct net_device *peer; + struct net *peer_net; + + 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; + + nla_peer = data[VXCAN_INFO_PEER]; + ifmp = nla_data(nla_peer); + err = rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack); + if (err < 0) + return err; + + 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_net = rtnl_link_get_net(net, tbp); + if (IS_ERR(peer_net)) + return PTR_ERR(peer_net); + + peer = rtnl_create_link(peer_net, ifname, name_assign_type, + &vxcan_link_ops, tbp, extack); + if (IS_ERR(peer)) { + put_net(peer_net); + return PTR_ERR(peer); + } + + if (ifmp && dev->ifindex) + peer->ifindex = ifmp->ifi_index; + + err = register_netdevice(peer); + put_net(peer_net); + peer_net = NULL; + 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); + + priv = netdev_priv(peer); + rcu_assign_pointer(priv->peer, dev); + + return 0; + +unregister_network_device: + unregister_netdevice(peer); + return err; +} + +static void vxcan_dellink(struct net_device *dev, struct list_head *head) +{ + struct vxcan_priv *priv; + struct net_device *peer; + + priv = netdev_priv(dev); + peer = rtnl_dereference(priv->peer); + + /* Note : dellink() is called from default_device_exit_batch(), + * before a rcu_synchronize() point. The devices are guaranteed + * not being freed before one RCU grace period. + */ + RCU_INIT_POINTER(priv->peer, NULL); + unregister_netdevice_queue(dev, head); + + if (peer) { + priv = netdev_priv(peer); + RCU_INIT_POINTER(priv->peer, NULL); + unregister_netdevice_queue(peer, head); + } +} + +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, + .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); -- cgit v1.2.3