Merge tag 'net-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

Pull networking updates from Paolo Abeni:
 "Core:

   - Implement the Device Memory TCP transmit path, allowing zero-copy
     data transmission on top of TCP from e.g. GPU memory to the wire.

   - Move all the IPv6 routing tables management outside the RTNL scope,
     under its own lock and RCU. The route control path is now 3x times
     faster.

   - Convert queue related netlink ops to instance lock, reducing again
     the scope of the RTNL lock. This improves the control plane
     scalability.

   - Refactor the software crc32c implementation, removing unneeded
     abstraction layers and improving significantly the related
     micro-benchmarks.

   - Optimize the GRO engine for UDP-tunneled traffic, for a 10%
     performance improvement in related stream tests.

   - Cover more per-CPU storage with local nested BH locking; this is a
     prep work to remove the current per-CPU lock in local_bh_disable()
     on PREMPT_RT.

   - Introduce and use nlmsg_payload helper, combining buffer bounds
     verification with accessing payload carried by netlink messages.

  Netfilter:

   - Rewrite the procfs conntrack table implementation, improving
     considerably the dump performance. A lot of user-space tools still
     use this interface.

   - Implement support for wildcard netdevice in netdev basechain and
     flowtables.

   - Integrate conntrack information into nft trace infrastructure.

   - Export set count and backend name to userspace, for better
     introspection.

  BPF:

   - BPF qdisc support: BPF-qdisc can be implemented with BPF struct_ops
     programs and can be controlled in similar way to traditional qdiscs
     using the "tc qdisc" command.

   - Refactor the UDP socket iterator, addressing long standing issues
     WRT duplicate hits or missed sockets.

  Protocols:

   - Improve TCP receive buffer auto-tuning and increase the default
     upper bound for the receive buffer; overall this improves the
     single flow maximum thoughput on 200Gbs link by over 60%.

   - Add AFS GSSAPI security class to AF_RXRPC; it provides transport
     security for connections to the AFS fileserver and VL server.

   - Improve TCP multipath routing, so that the sources address always
     matches the nexthop device.

   - Introduce SO_PASSRIGHTS for AF_UNIX, to allow disabling SCM_RIGHTS,
     and thus preventing DoS caused by passing around problematic FDs.

   - Retire DCCP socket. DCCP only receives updates for bugs, and major
     distros disable it by default. Its removal allows for better
     organisation of TCP fields to reduce the number of cache lines hit
     in the fast path.

   - Extend TCP drop-reason support to cover PAWS checks.

  Driver API:

   - Reorganize PTP ioctl flag support to require an explicit opt-in for
     the drivers, avoiding the problem of drivers not rejecting new
     unsupported flags.

   - Converted several device drivers to timestamping APIs.

   - Introduce per-PHY ethtool dump helpers, improving the support for
     dump operations targeting PHYs.

  Tests and tooling:

   - Add support for classic netlink in user space C codegen, so that
     ynl-c can now read, create and modify links, routes addresses and
     qdisc layer configuration.

   - Add ynl sub-types for binary attributes, allowing ynl-c to output
     known struct instead of raw binary data, clarifying the classic
     netlink output.

   - Extend MPTCP selftests to improve the code-coverage.

   - Add tests for XDP tail adjustment in AF_XDP.

  New hardware / drivers:

   - OpenVPN virtual driver: offload OpenVPN data channels processing to
     the kernel-space, increasing the data transfer throughput WRT the
     user-space implementation.

   - Renesas glue driver for the gigabit ethernet RZ/V2H(P) SoC.

   - Broadcom asp-v3.0 ethernet driver.

   - AMD Renoir ethernet device.

   - ReakTek MT9888 2.5G ethernet PHY driver.

   - Aeonsemi 10G C45 PHYs driver.

  Drivers:

   - Ethernet high-speed NICs:
       - nVidia/Mellanox (mlx5):
           - refactor the steering table handling to significantly
             reduce the amount of memory used
           - add support for complex matches in H/W flow steering
           - improve flow streeing error handling
           - convert to netdev instance locking
       - Intel (100G, ice, igb, ixgbe, idpf):
           - ice: add switchdev support for LLDP traffic over VF
           - ixgbe: add firmware manipulation and regions devlink support
           - igb: introduce support for frame transmission premption
           - igb: adds persistent NAPI configuration
           - idpf: introduce RDMA support
           - idpf: add initial PTP support
       - Meta (fbnic):
           - extend hardware stats coverage
           - add devlink dev flash support
       - Broadcom (bnxt):
           - add support for RX-side device memory TCP
       - Wangxun (txgbe):
           - implement support for udp tunnel offload
           - complete PTP and SRIOV support for AML 25G/10G devices

   - Ethernet NICs embedded and virtual:
       - Google (gve):
           - add device memory TCP TX support
       - Amazon (ena):
           - support persistent per-NAPI config
       - Airoha:
           - add H/W support for L2 traffic offload
           - add per flow stats for flow offloading
       - RealTek (rtl8211): add support for WoL magic packet
       - Synopsys (stmmac):
           - dwmac-socfpga 1000BaseX support
           - add Loongson-2K3000 support
           - introduce support for hardware-accelerated VLAN stripping
       - Broadcom (bcmgenet):
           - expose more H/W stats
       - Freescale (enetc, dpaa2-eth):
           - enetc: add MAC filter, VLAN filter RSS and loopback support
           - dpaa2-eth: convert to H/W timestamping APIs
       - vxlan: convert FDB table to rhashtable, for better scalabilty
       - veth: apply qdisc backpressure on full ring to reduce TX drops

   - Ethernet switches:
       - Microchip (kzZ88x3): add ETS scheduler support

   - Ethernet PHYs:
       - RealTek (rtl8211):
           - add support for WoL magic packet
           - add support for PHY LEDs

   - CAN:
       - Adds RZ/G3E CANFD support to the rcar_canfd driver.
       - Preparatory work for CAN-XL support.
       - Add self-tests framework with support for CAN physical interfaces.

   - WiFi:
       - mac80211:
           - scan improvements with multi-link operation (MLO)
       - Qualcomm (ath12k):
           - enable AHB support for IPQ5332
           - add monitor interface support to QCN9274
           - add multi-link operation support to WCN7850
           - add 802.11d scan offload support to WCN7850
           - monitor mode for WCN7850, better 6 GHz regulatory
       - Qualcomm (ath11k):
           - restore hibernation support
       - MediaTek (mt76):
           - WiFi-7 improvements
           - implement support for mt7990
       - Intel (iwlwifi):
           - enhanced multi-link single-radio (EMLSR) support on 5 GHz links
           - rework device configuration
       - RealTek (rtw88):
           - improve throughput for RTL8814AU
       - RealTek (rtw89):
           - add multi-link operation support
           - STA/P2P concurrency improvements
           - support different SAR configs by antenna

   - Bluetooth:
       - introduce HCI Driver protocol
       - btintel_pcie: do not generate coredump for diagnostic events
       - btusb: add HCI Drv commands for configuring altsetting
       - btusb: add RTL8851BE device 0x0bda:0xb850
       - btusb: add new VID/PID 13d3/3584 for MT7922
       - btusb: add new VID/PID 13d3/3630 and 13d3/3613 for MT7925
       - btnxpuart: implement host-wakeup feature"

* tag 'net-next-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1611 commits)
  selftests/bpf: Fix bpf selftest build warning
  selftests: netfilter: Fix skip of wildcard interface test
  net: phy: mscc: Stop clearing the the UDPv4 checksum for L2 frames
  net: openvswitch: Fix the dead loop of MPLS parse
  calipso: Don't call calipso functions for AF_INET sk.
  selftests/tc-testing: Add a test for HFSC eltree double add with reentrant enqueue behaviour on netem
  net_sched: hfsc: Address reentrant enqueue adding class to eltree twice
  octeontx2-pf: QOS: Refactor TC_HTB_LEAF_DEL_LAST callback
  octeontx2-pf: QOS: Perform cache sync on send queue teardown
  net: mana: Add support for Multi Vports on Bare metal
  net: devmem: ncdevmem: remove unused variable
  net: devmem: ksft: upgrade rx test to send 1K data
  net: devmem: ksft: add 5 tuple FS support
  net: devmem: ksft: add exit_wait to make rx test pass
  net: devmem: ksft: add ipv4 support
  net: devmem: preserve sockc_err
  page_pool: fix ugly page_pool formatting
  net: devmem: move list_add to net_devmem_bind_dmabuf.
  selftests: netfilter: nft_queue.sh: include file transfer duration in log message
  net: phy: mscc: Fix memory leak when using one step timestamping
  ...

1 files changed, 458 insertions, 0 deletions

diff --git a/drivers/net/ovpn/io.c b/drivers/net/ovpn/io.c
new file mode 100644
index 000000000000..10d8afecec55
--- /dev/null
+++ b/drivers/net/ovpn/io.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0
+/*  OpenVPN data channel offload
+ *
+ *  Copyright (C) 2019-2025 OpenVPN, Inc.
+ *
+ *  Author:	James Yonan <james@openvpn.net>
+ *		Antonio Quartulli <antonio@openvpn.net>
+ */
+
+#include <crypto/aead.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/gro_cells.h>
+#include <net/gso.h>
+#include <net/ip.h>
+
+#include "ovpnpriv.h"
+#include "peer.h"
+#include "io.h"
+#include "bind.h"
+#include "crypto.h"
+#include "crypto_aead.h"
+#include "netlink.h"
+#include "proto.h"
+#include "tcp.h"
+#include "udp.h"
+#include "skb.h"
+#include "socket.h"
+
+const unsigned char ovpn_keepalive_message[OVPN_KEEPALIVE_SIZE] = {
+	0x2a, 0x18, 0x7b, 0xf3, 0x64, 0x1e, 0xb4, 0xcb,
+	0x07, 0xed, 0x2d, 0x0a, 0x98, 0x1f, 0xc7, 0x48
+};
+
+/**
+ * ovpn_is_keepalive - check if skb contains a keepalive message
+ * @skb: packet to check
+ *
+ * Assumes that the first byte of skb->data is defined.
+ *
+ * Return: true if skb contains a keepalive or false otherwise
+ */
+static bool ovpn_is_keepalive(struct sk_buff *skb)
+{
+	if (*skb->data != ovpn_keepalive_message[0])
+		return false;
+
+	if (skb->len != OVPN_KEEPALIVE_SIZE)
+		return false;
+
+	if (!pskb_may_pull(skb, OVPN_KEEPALIVE_SIZE))
+		return false;
+
+	return !memcmp(skb->data, ovpn_keepalive_message, OVPN_KEEPALIVE_SIZE);
+}
+
+/* Called after decrypt to write the IP packet to the device.
+ * This method is expected to manage/free the skb.
+ */
+static void ovpn_netdev_write(struct ovpn_peer *peer, struct sk_buff *skb)
+{
+	unsigned int pkt_len;
+	int ret;
+
+	/* we can't guarantee the packet wasn't corrupted before entering the
+	 * VPN, therefore we give other layers a chance to check that
+	 */
+	skb->ip_summed = CHECKSUM_NONE;
+
+	/* skb hash for transport packet no longer valid after decapsulation */
+	skb_clear_hash(skb);
+
+	/* post-decrypt scrub -- prepare to inject encapsulated packet onto the
+	 * interface, based on __skb_tunnel_rx() in dst.h
+	 */
+	skb->dev = peer->ovpn->dev;
+	skb_set_queue_mapping(skb, 0);
+	skb_scrub_packet(skb, true);
+
+	/* network header reset in ovpn_decrypt_post() */
+	skb_reset_transport_header(skb);
+	skb_reset_inner_headers(skb);
+
+	/* cause packet to be "received" by the interface */
+	pkt_len = skb->len;
+	ret = gro_cells_receive(&peer->ovpn->gro_cells, skb);
+	if (likely(ret == NET_RX_SUCCESS)) {
+		/* update RX stats with the size of decrypted packet */
+		ovpn_peer_stats_increment_rx(&peer->vpn_stats, pkt_len);
+		dev_dstats_rx_add(peer->ovpn->dev, pkt_len);
+	}
+}
+
+void ovpn_decrypt_post(void *data, int ret)
+{
+	struct ovpn_crypto_key_slot *ks;
+	unsigned int payload_offset = 0;
+	struct sk_buff *skb = data;
+	struct ovpn_socket *sock;
+	struct ovpn_peer *peer;
+	__be16 proto;
+	__be32 *pid;
+
+	/* crypto is happening asynchronously. this function will be called
+	 * again later by the crypto callback with a proper return code
+	 */
+	if (unlikely(ret == -EINPROGRESS))
+		return;
+
+	payload_offset = ovpn_skb_cb(skb)->payload_offset;
+	ks = ovpn_skb_cb(skb)->ks;
+	peer = ovpn_skb_cb(skb)->peer;
+
+	/* crypto is done, cleanup skb CB and its members */
+	kfree(ovpn_skb_cb(skb)->iv);
+	kfree(ovpn_skb_cb(skb)->sg);
+	aead_request_free(ovpn_skb_cb(skb)->req);
+
+	if (unlikely(ret < 0))
+		goto drop;
+
+	/* PID sits after the op */
+	pid = (__force __be32 *)(skb->data + OVPN_OPCODE_SIZE);
+	ret = ovpn_pktid_recv(&ks->pid_recv, ntohl(*pid), 0);
+	if (unlikely(ret < 0)) {
+		net_err_ratelimited("%s: PKT ID RX error for peer %u: %d\n",
+				    netdev_name(peer->ovpn->dev), peer->id,
+				    ret);
+		goto drop;
+	}
+
+	/* keep track of last received authenticated packet for keepalive */
+	WRITE_ONCE(peer->last_recv, ktime_get_real_seconds());
+
+	rcu_read_lock();
+	sock = rcu_dereference(peer->sock);
+	if (sock && sock->sock->sk->sk_protocol == IPPROTO_UDP)
+		/* check if this peer changed local or remote endpoint */
+		ovpn_peer_endpoints_update(peer, skb);
+	rcu_read_unlock();
+
+	/* point to encapsulated IP packet */
+	__skb_pull(skb, payload_offset);
+
+	/* check if this is a valid datapacket that has to be delivered to the
+	 * ovpn interface
+	 */
+	skb_reset_network_header(skb);
+	proto = ovpn_ip_check_protocol(skb);
+	if (unlikely(!proto)) {
+		/* check if null packet */
+		if (unlikely(!pskb_may_pull(skb, 1))) {
+			net_info_ratelimited("%s: NULL packet received from peer %u\n",
+					     netdev_name(peer->ovpn->dev),
+					     peer->id);
+			goto drop;
+		}
+
+		if (ovpn_is_keepalive(skb)) {
+			net_dbg_ratelimited("%s: ping received from peer %u\n",
+					    netdev_name(peer->ovpn->dev),
+					    peer->id);
+			/* we drop the packet, but this is not a failure */
+			consume_skb(skb);
+			goto drop_nocount;
+		}
+
+		net_info_ratelimited("%s: unsupported protocol received from peer %u\n",
+				     netdev_name(peer->ovpn->dev), peer->id);
+		goto drop;
+	}
+	skb->protocol = proto;
+
+	/* perform Reverse Path Filtering (RPF) */
+	if (unlikely(!ovpn_peer_check_by_src(peer->ovpn, skb, peer))) {
+		if (skb->protocol == htons(ETH_P_IPV6))
+			net_dbg_ratelimited("%s: RPF dropped packet from peer %u, src: %pI6c\n",
+					    netdev_name(peer->ovpn->dev),
+					    peer->id, &ipv6_hdr(skb)->saddr);
+		else
+			net_dbg_ratelimited("%s: RPF dropped packet from peer %u, src: %pI4\n",
+					    netdev_name(peer->ovpn->dev),
+					    peer->id, &ip_hdr(skb)->saddr);
+		goto drop;
+	}
+
+	ovpn_netdev_write(peer, skb);
+	/* skb is passed to upper layer - don't free it */
+	skb = NULL;
+drop:
+	if (unlikely(skb))
+		dev_dstats_rx_dropped(peer->ovpn->dev);
+	kfree_skb(skb);
+drop_nocount:
+	if (likely(peer))
+		ovpn_peer_put(peer);
+	if (likely(ks))
+		ovpn_crypto_key_slot_put(ks);
+}
+
+/* RX path entry point: decrypt packet and forward it to the device */
+void ovpn_recv(struct ovpn_peer *peer, struct sk_buff *skb)
+{
+	struct ovpn_crypto_key_slot *ks;
+	u8 key_id;
+
+	ovpn_peer_stats_increment_rx(&peer->link_stats, skb->len);
+
+	/* get the key slot matching the key ID in the received packet */
+	key_id = ovpn_key_id_from_skb(skb);
+	ks = ovpn_crypto_key_id_to_slot(&peer->crypto, key_id);
+	if (unlikely(!ks)) {
+		net_info_ratelimited("%s: no available key for peer %u, key-id: %u\n",
+				     netdev_name(peer->ovpn->dev), peer->id,
+				     key_id);
+		dev_dstats_rx_dropped(peer->ovpn->dev);
+		kfree_skb(skb);
+		ovpn_peer_put(peer);
+		return;
+	}
+
+	memset(ovpn_skb_cb(skb), 0, sizeof(struct ovpn_cb));
+	ovpn_decrypt_post(skb, ovpn_aead_decrypt(peer, ks, skb));
+}
+
+void ovpn_encrypt_post(void *data, int ret)
+{
+	struct ovpn_crypto_key_slot *ks;
+	struct sk_buff *skb = data;
+	struct ovpn_socket *sock;
+	struct ovpn_peer *peer;
+	unsigned int orig_len;
+
+	/* encryption is happening asynchronously. This function will be
+	 * called later by the crypto callback with a proper return value
+	 */
+	if (unlikely(ret == -EINPROGRESS))
+		return;
+
+	ks = ovpn_skb_cb(skb)->ks;
+	peer = ovpn_skb_cb(skb)->peer;
+
+	/* crypto is done, cleanup skb CB and its members */
+	kfree(ovpn_skb_cb(skb)->iv);
+	kfree(ovpn_skb_cb(skb)->sg);
+	aead_request_free(ovpn_skb_cb(skb)->req);
+
+	if (unlikely(ret == -ERANGE)) {
+		/* we ran out of IVs and we must kill the key as it can't be
+		 * use anymore
+		 */
+		netdev_warn(peer->ovpn->dev,
+			    "killing key %u for peer %u\n", ks->key_id,
+			    peer->id);
+		if (ovpn_crypto_kill_key(&peer->crypto, ks->key_id))
+			/* let userspace know so that a new key must be negotiated */
+			ovpn_nl_key_swap_notify(peer, ks->key_id);
+
+		goto err;
+	}
+
+	if (unlikely(ret < 0))
+		goto err;
+
+	skb_mark_not_on_list(skb);
+	orig_len = skb->len;
+
+	rcu_read_lock();
+	sock = rcu_dereference(peer->sock);
+	if (unlikely(!sock))
+		goto err_unlock;
+
+	switch (sock->sock->sk->sk_protocol) {
+	case IPPROTO_UDP:
+		ovpn_udp_send_skb(peer, sock->sock, skb);
+		break;
+	case IPPROTO_TCP:
+		ovpn_tcp_send_skb(peer, sock->sock, skb);
+		break;
+	default:
+		/* no transport configured yet */
+		goto err_unlock;
+	}
+
+	ovpn_peer_stats_increment_tx(&peer->link_stats, orig_len);
+	/* keep track of last sent packet for keepalive */
+	WRITE_ONCE(peer->last_sent, ktime_get_real_seconds());
+	/* skb passed down the stack - don't free it */
+	skb = NULL;
+err_unlock:
+	rcu_read_unlock();
+err:
+	if (unlikely(skb))
+		dev_dstats_tx_dropped(peer->ovpn->dev);
+	if (likely(peer))
+		ovpn_peer_put(peer);
+	if (likely(ks))
+		ovpn_crypto_key_slot_put(ks);
+	kfree_skb(skb);
+}
+
+static bool ovpn_encrypt_one(struct ovpn_peer *peer, struct sk_buff *skb)
+{
+	struct ovpn_crypto_key_slot *ks;
+
+	/* get primary key to be used for encrypting data */
+	ks = ovpn_crypto_key_slot_primary(&peer->crypto);
+	if (unlikely(!ks))
+		return false;
+
+	/* take a reference to the peer because the crypto code may run async.
+	 * ovpn_encrypt_post() will release it upon completion
+	 */
+	if (unlikely(!ovpn_peer_hold(peer))) {
+		DEBUG_NET_WARN_ON_ONCE(1);
+		ovpn_crypto_key_slot_put(ks);
+		return false;
+	}
+
+	memset(ovpn_skb_cb(skb), 0, sizeof(struct ovpn_cb));
+	ovpn_encrypt_post(skb, ovpn_aead_encrypt(peer, ks, skb));
+	return true;
+}
+
+/* send skb to connected peer, if any */
+static void ovpn_send(struct ovpn_priv *ovpn, struct sk_buff *skb,
+		      struct ovpn_peer *peer)
+{
+	struct sk_buff *curr, *next;
+
+	/* this might be a GSO-segmented skb list: process each skb
+	 * independently
+	 */
+	skb_list_walk_safe(skb, curr, next) {
+		if (unlikely(!ovpn_encrypt_one(peer, curr))) {
+			dev_dstats_tx_dropped(ovpn->dev);
+			kfree_skb(curr);
+		}
+	}
+
+	ovpn_peer_put(peer);
+}
+
+/* Send user data to the network
+ */
+netdev_tx_t ovpn_net_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct ovpn_priv *ovpn = netdev_priv(dev);
+	struct sk_buff *segments, *curr, *next;
+	struct sk_buff_head skb_list;
+	struct ovpn_peer *peer;
+	__be16 proto;
+	int ret;
+
+	/* reset netfilter state */
+	nf_reset_ct(skb);
+
+	/* verify IP header size in network packet */
+	proto = ovpn_ip_check_protocol(skb);
+	if (unlikely(!proto || skb->protocol != proto))
+		goto drop;
+
+	if (skb_is_gso(skb)) {
+		segments = skb_gso_segment(skb, 0);
+		if (IS_ERR(segments)) {
+			ret = PTR_ERR(segments);
+			net_err_ratelimited("%s: cannot segment payload packet: %d\n",
+					    netdev_name(dev), ret);
+			goto drop;
+		}
+
+		consume_skb(skb);
+		skb = segments;
+	}
+
+	/* from this moment on, "skb" might be a list */
+
+	__skb_queue_head_init(&skb_list);
+	skb_list_walk_safe(skb, curr, next) {
+		skb_mark_not_on_list(curr);
+
+		curr = skb_share_check(curr, GFP_ATOMIC);
+		if (unlikely(!curr)) {
+			net_err_ratelimited("%s: skb_share_check failed for payload packet\n",
+					    netdev_name(dev));
+			dev_dstats_tx_dropped(ovpn->dev);
+			continue;
+		}
+
+		__skb_queue_tail(&skb_list, curr);
+	}
+	skb_list.prev->next = NULL;
+
+	/* retrieve peer serving the destination IP of this packet */
+	peer = ovpn_peer_get_by_dst(ovpn, skb);
+	if (unlikely(!peer)) {
+		switch (skb->protocol) {
+		case htons(ETH_P_IP):
+			net_dbg_ratelimited("%s: no peer to send data to dst=%pI4\n",
+					    netdev_name(ovpn->dev),
+					    &ip_hdr(skb)->daddr);
+			break;
+		case htons(ETH_P_IPV6):
+			net_dbg_ratelimited("%s: no peer to send data to dst=%pI6c\n",
+					    netdev_name(ovpn->dev),
+					    &ipv6_hdr(skb)->daddr);
+			break;
+		}
+		goto drop;
+	}
+	/* dst was needed for peer selection - it can now be dropped */
+	skb_dst_drop(skb);
+
+	ovpn_peer_stats_increment_tx(&peer->vpn_stats, skb->len);
+	ovpn_send(ovpn, skb_list.next, peer);
+
+	return NETDEV_TX_OK;
+
+drop:
+	dev_dstats_tx_dropped(ovpn->dev);
+	skb_tx_error(skb);
+	kfree_skb_list(skb);
+	return NETDEV_TX_OK;
+}
+
+/**
+ * ovpn_xmit_special - encrypt and transmit an out-of-band message to peer
+ * @peer: peer to send the message to
+ * @data: message content
+ * @len: message length
+ *
+ * Assumes that caller holds a reference to peer, which will be
+ * passed to ovpn_send()
+ */
+void ovpn_xmit_special(struct ovpn_peer *peer, const void *data,
+		       const unsigned int len)
+{
+	struct ovpn_priv *ovpn;
+	struct sk_buff *skb;
+
+	ovpn = peer->ovpn;
+	if (unlikely(!ovpn)) {
+		ovpn_peer_put(peer);
+		return;
+	}
+
+	skb = alloc_skb(256 + len, GFP_ATOMIC);
+	if (unlikely(!skb)) {
+		ovpn_peer_put(peer);
+		return;
+	}
+
+	skb_reserve(skb, 128);
+	skb->priority = TC_PRIO_BESTEFFORT;
+	__skb_put_data(skb, data, len);
+
+	ovpn_send(ovpn, skb, peer);
+}