diff options
Diffstat (limited to 'drivers/net/ovpn/main.c')
| -rw-r--r-- | drivers/net/ovpn/main.c | 279 |
1 files changed, 279 insertions, 0 deletions
diff --git a/drivers/net/ovpn/main.c b/drivers/net/ovpn/main.c new file mode 100644 index 000000000000..1bb1afe766a4 --- /dev/null +++ b/drivers/net/ovpn/main.c @@ -0,0 +1,279 @@ +// SPDX-License-Identifier: GPL-2.0 +/* OpenVPN data channel offload + * + * Copyright (C) 2020-2025 OpenVPN, Inc. + * + * Author: Antonio Quartulli <antonio@openvpn.net> + * James Yonan <james@openvpn.net> + */ + +#include <linux/ethtool.h> +#include <linux/genetlink.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/inetdevice.h> +#include <net/gro_cells.h> +#include <net/ip.h> +#include <net/rtnetlink.h> +#include <uapi/linux/if_arp.h> + +#include "ovpnpriv.h" +#include "main.h" +#include "netlink.h" +#include "io.h" +#include "peer.h" +#include "proto.h" +#include "tcp.h" +#include "udp.h" + +static void ovpn_priv_free(struct net_device *net) +{ + struct ovpn_priv *ovpn = netdev_priv(net); + + kfree(ovpn->peers); +} + +static int ovpn_mp_alloc(struct ovpn_priv *ovpn) +{ + struct in_device *dev_v4; + int i; + + if (ovpn->mode != OVPN_MODE_MP) + return 0; + + dev_v4 = __in_dev_get_rtnl(ovpn->dev); + if (dev_v4) { + /* disable redirects as Linux gets confused by ovpn + * handling same-LAN routing. + * This happens because a multipeer interface is used as + * relay point between hosts in the same subnet, while + * in a classic LAN this would not be needed because the + * two hosts would be able to talk directly. + */ + IN_DEV_CONF_SET(dev_v4, SEND_REDIRECTS, false); + IPV4_DEVCONF_ALL(dev_net(ovpn->dev), SEND_REDIRECTS) = false; + } + + /* the peer container is fairly large, therefore we allocate it only in + * MP mode + */ + ovpn->peers = kzalloc(sizeof(*ovpn->peers), GFP_KERNEL); + if (!ovpn->peers) + return -ENOMEM; + + for (i = 0; i < ARRAY_SIZE(ovpn->peers->by_id); i++) { + INIT_HLIST_HEAD(&ovpn->peers->by_id[i]); + INIT_HLIST_NULLS_HEAD(&ovpn->peers->by_vpn_addr4[i], i); + INIT_HLIST_NULLS_HEAD(&ovpn->peers->by_vpn_addr6[i], i); + INIT_HLIST_NULLS_HEAD(&ovpn->peers->by_transp_addr[i], i); + } + + return 0; +} + +static int ovpn_net_init(struct net_device *dev) +{ + struct ovpn_priv *ovpn = netdev_priv(dev); + int err = gro_cells_init(&ovpn->gro_cells, dev); + + if (err < 0) + return err; + + err = ovpn_mp_alloc(ovpn); + if (err < 0) { + gro_cells_destroy(&ovpn->gro_cells); + return err; + } + + return 0; +} + +static void ovpn_net_uninit(struct net_device *dev) +{ + struct ovpn_priv *ovpn = netdev_priv(dev); + + gro_cells_destroy(&ovpn->gro_cells); +} + +static const struct net_device_ops ovpn_netdev_ops = { + .ndo_init = ovpn_net_init, + .ndo_uninit = ovpn_net_uninit, + .ndo_start_xmit = ovpn_net_xmit, +}; + +static const struct device_type ovpn_type = { + .name = OVPN_FAMILY_NAME, +}; + +static const struct nla_policy ovpn_policy[IFLA_OVPN_MAX + 1] = { + [IFLA_OVPN_MODE] = NLA_POLICY_RANGE(NLA_U8, OVPN_MODE_P2P, + OVPN_MODE_MP), +}; + +/** + * ovpn_dev_is_valid - check if the netdevice is of type 'ovpn' + * @dev: the interface to check + * + * Return: whether the netdevice is of type 'ovpn' + */ +bool ovpn_dev_is_valid(const struct net_device *dev) +{ + return dev->netdev_ops == &ovpn_netdev_ops; +} + +static void ovpn_get_drvinfo(struct net_device *dev, + struct ethtool_drvinfo *info) +{ + strscpy(info->driver, "ovpn", sizeof(info->driver)); + strscpy(info->bus_info, "ovpn", sizeof(info->bus_info)); +} + +static const struct ethtool_ops ovpn_ethtool_ops = { + .get_drvinfo = ovpn_get_drvinfo, + .get_link = ethtool_op_get_link, + .get_ts_info = ethtool_op_get_ts_info, +}; + +static void ovpn_setup(struct net_device *dev) +{ + netdev_features_t feat = NETIF_F_SG | NETIF_F_GSO | + NETIF_F_GSO_SOFTWARE | NETIF_F_HIGHDMA; + + dev->needs_free_netdev = true; + + dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS; + + dev->ethtool_ops = &ovpn_ethtool_ops; + dev->netdev_ops = &ovpn_netdev_ops; + + dev->priv_destructor = ovpn_priv_free; + + dev->hard_header_len = 0; + dev->addr_len = 0; + dev->mtu = ETH_DATA_LEN - OVPN_HEAD_ROOM; + dev->min_mtu = IPV4_MIN_MTU; + dev->max_mtu = IP_MAX_MTU - OVPN_HEAD_ROOM; + + dev->type = ARPHRD_NONE; + dev->flags = IFF_POINTOPOINT | IFF_NOARP; + dev->priv_flags |= IFF_NO_QUEUE; + /* when routing packets to a LAN behind a client, we rely on the + * route entry that originally brought the packet into ovpn, so + * don't release it + */ + netif_keep_dst(dev); + + dev->lltx = true; + dev->features |= feat; + dev->hw_features |= feat; + dev->hw_enc_features |= feat; + + dev->needed_headroom = ALIGN(OVPN_HEAD_ROOM, 4); + dev->needed_tailroom = OVPN_MAX_PADDING; + + SET_NETDEV_DEVTYPE(dev, &ovpn_type); +} + +static int ovpn_newlink(struct net_device *dev, + struct rtnl_newlink_params *params, + struct netlink_ext_ack *extack) +{ + struct ovpn_priv *ovpn = netdev_priv(dev); + struct nlattr **data = params->data; + enum ovpn_mode mode = OVPN_MODE_P2P; + + if (data && data[IFLA_OVPN_MODE]) { + mode = nla_get_u8(data[IFLA_OVPN_MODE]); + netdev_dbg(dev, "setting device mode: %u\n", mode); + } + + ovpn->dev = dev; + ovpn->mode = mode; + spin_lock_init(&ovpn->lock); + INIT_DELAYED_WORK(&ovpn->keepalive_work, ovpn_peer_keepalive_work); + + /* Set carrier explicitly after registration, this way state is + * clearly defined. + * + * In case of MP interfaces we keep the carrier always on. + * + * Carrier for P2P interfaces is initially off and it is then + * switched on and off when the remote peer is added or deleted. + */ + if (ovpn->mode == OVPN_MODE_MP) + netif_carrier_on(dev); + else + netif_carrier_off(dev); + + return register_netdevice(dev); +} + +static void ovpn_dellink(struct net_device *dev, struct list_head *head) +{ + struct ovpn_priv *ovpn = netdev_priv(dev); + + cancel_delayed_work_sync(&ovpn->keepalive_work); + ovpn_peers_free(ovpn, NULL, OVPN_DEL_PEER_REASON_TEARDOWN); + unregister_netdevice_queue(dev, head); +} + +static int ovpn_fill_info(struct sk_buff *skb, const struct net_device *dev) +{ + struct ovpn_priv *ovpn = netdev_priv(dev); + + if (nla_put_u8(skb, IFLA_OVPN_MODE, ovpn->mode)) + return -EMSGSIZE; + + return 0; +} + +static struct rtnl_link_ops ovpn_link_ops = { + .kind = "ovpn", + .netns_refund = false, + .priv_size = sizeof(struct ovpn_priv), + .setup = ovpn_setup, + .policy = ovpn_policy, + .maxtype = IFLA_OVPN_MAX, + .newlink = ovpn_newlink, + .dellink = ovpn_dellink, + .fill_info = ovpn_fill_info, +}; + +static int __init ovpn_init(void) +{ + int err = rtnl_link_register(&ovpn_link_ops); + + if (err) { + pr_err("ovpn: can't register rtnl link ops: %d\n", err); + return err; + } + + err = ovpn_nl_register(); + if (err) { + pr_err("ovpn: can't register netlink family: %d\n", err); + goto unreg_rtnl; + } + + ovpn_tcp_init(); + + return 0; + +unreg_rtnl: + rtnl_link_unregister(&ovpn_link_ops); + return err; +} + +static __exit void ovpn_cleanup(void) +{ + ovpn_nl_unregister(); + rtnl_link_unregister(&ovpn_link_ops); + + rcu_barrier(); +} + +module_init(ovpn_init); +module_exit(ovpn_cleanup); + +MODULE_DESCRIPTION("OpenVPN data channel offload (ovpn)"); +MODULE_AUTHOR("Antonio Quartulli <antonio@openvpn.net>"); +MODULE_LICENSE("GPL"); |