Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted

Pull networking updates from Jakub Kicinski:
 "Core:

   - Add dedicated kmem_cache for typical/small skb->head, avoid having
     to access struct page at kfree time, and improve memory use.

   - Introduce sysctl to set default RPS configuration for new netdevs.

   - Define Netlink protocol specification format which can be used to
     describe messages used by each family and auto-generate parsers.
     Add tools for generating kernel data structures and uAPI headers.

   - Expose all net/core sysctls inside netns.

   - Remove 4s sleep in netpoll if carrier is instantly detected on
     boot.

   - Add configurable limit of MDB entries per port, and port-vlan.

   - Continue populating drop reasons throughout the stack.

   - Retire a handful of legacy Qdiscs and classifiers.

  Protocols:

   - Support IPv4 big TCP (TSO frames larger than 64kB).

   - Add IP_LOCAL_PORT_RANGE socket option, to control local port range
     on socket by socket basis.

   - Track and report in procfs number of MPTCP sockets used.

   - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path
     manager.

   - IPv6: don't check net.ipv6.route.max_size and rely on garbage
     collection to free memory (similarly to IPv4).

   - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986).

   - ICMP: add per-rate limit counters.

   - Add support for user scanning requests in ieee802154.

   - Remove static WEP support.

   - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate
     reporting.

   - WiFi 7 EHT channel puncturing support (client & AP).

  BPF:

   - Add a rbtree data structure following the "next-gen data structure"
     precedent set by recently added linked list, that is, by using
     kfunc + kptr instead of adding a new BPF map type.

   - Expose XDP hints via kfuncs with initial support for RX hash and
     timestamp metadata.

   - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to
     better support decap on GRE tunnel devices not operating in collect
     metadata.

   - Improve x86 JIT's codegen for PROBE_MEM runtime error checks.

   - Remove the need for trace_printk_lock for bpf_trace_printk and
     bpf_trace_vprintk helpers.

   - Extend libbpf's bpf_tracing.h support for tracing arguments of
     kprobes/uprobes and syscall as a special case.

   - Significantly reduce the search time for module symbols by
     livepatch and BPF.

   - Enable cpumasks to be used as kptrs, which is useful for tracing
     programs tracking which tasks end up running on which CPUs in
     different time intervals.

   - Add support for BPF trampoline on s390x and riscv64.

   - Add capability to export the XDP features supported by the NIC.

   - Add __bpf_kfunc tag for marking kernel functions as kfuncs.

   - Add cgroup.memory=nobpf kernel parameter option to disable BPF
     memory accounting for container environments.

  Netfilter:

   - Remove the CLUSTERIP target. It has been marked as obsolete for
     years, and we still have WARN splats wrt races of the out-of-band
     /proc interface installed by this target.

   - Add 'destroy' commands to nf_tables. They are identical to the
     existing 'delete' commands, but do not return an error if the
     referenced object (set, chain, rule...) did not exist.

  Driver API:

   - Improve cpumask_local_spread() locality to help NICs set the right
     IRQ affinity on AMD platforms.

   - Separate C22 and C45 MDIO bus transactions more clearly.

   - Introduce new DCB table to control DSCP rewrite on egress.

   - Support configuration of Physical Layer Collision Avoidance (PLCA)
     Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of
     shared medium Ethernet.

   - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing
     preemption of low priority frames by high priority frames.

   - Add support for controlling MACSec offload using netlink SET.

   - Rework devlink instance refcounts to allow registration and
     de-registration under the instance lock. Split the code into
     multiple files, drop some of the unnecessarily granular locks and
     factor out common parts of netlink operation handling.

   - Add TX frame aggregation parameters (for USB drivers).

   - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning
     messages with notifications for debug.

   - Allow offloading of UDP NEW connections via act_ct.

   - Add support for per action HW stats in TC.

   - Support hardware miss to TC action (continue processing in SW from
     a specific point in the action chain).

   - Warn if old Wireless Extension user space interface is used with
     modern cfg80211/mac80211 drivers. Do not support Wireless
     Extensions for Wi-Fi 7 devices at all. Everyone should switch to
     using nl80211 interface instead.

   - Improve the CAN bit timing configuration. Use extack to return
     error messages directly to user space, update the SJW handling,
     including the definition of a new default value that will benefit
     CAN-FD controllers, by increasing their oscillator tolerance.

  New hardware / drivers:

   - Ethernet:
      - nVidia BlueField-3 support (control traffic driver)
      - Ethernet support for imx93 SoCs
      - Motorcomm yt8531 gigabit Ethernet PHY
      - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA)
      - Microchip LAN8841 PHY (incl. cable diagnostics and PTP)
      - Amlogic gxl MDIO mux

   - WiFi:
      - RealTek RTL8188EU (rtl8xxxu)
      - Qualcomm Wi-Fi 7 devices (ath12k)

   - CAN:
      - Renesas R-Car V4H

  Drivers:

   - Bluetooth:
      - Set Per Platform Antenna Gain (PPAG) for Intel controllers.

   - Ethernet NICs:
      - Intel (1G, igc):
         - support TSN / Qbv / packet scheduling features of i226 model
      - Intel (100G, ice):
         - use GNSS subsystem instead of TTY
         - multi-buffer XDP support
         - extend support for GPIO pins to E823 devices
      - nVidia/Mellanox:
         - update the shared buffer configuration on PFC commands
         - implement PTP adjphase function for HW offset control
         - TC support for Geneve and GRE with VF tunnel offload
         - more efficient crypto key management method
         - multi-port eswitch support
      - Netronome/Corigine:
         - add DCB IEEE support
         - support IPsec offloading for NFP3800
      - Freescale/NXP (enetc):
         - support XDP_REDIRECT for XDP non-linear buffers
         - improve reconfig, avoid link flap and waiting for idle
         - support MAC Merge layer
      - Other NICs:
         - sfc/ef100: add basic devlink support for ef100
         - ionic: rx_push mode operation (writing descriptors via MMIO)
         - bnxt: use the auxiliary bus abstraction for RDMA
         - r8169: disable ASPM and reset bus in case of tx timeout
         - cpsw: support QSGMII mode for J721e CPSW9G
         - cpts: support pulse-per-second output
         - ngbe: add an mdio bus driver
         - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing
         - r8152: handle devices with FW with NCM support
         - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation
         - virtio-net: support multi buffer XDP
         - virtio/vsock: replace virtio_vsock_pkt with sk_buff
         - tsnep: XDP support

   - Ethernet high-speed switches:
      - nVidia/Mellanox (mlxsw):
         - add support for latency TLV (in FW control messages)
      - Microchip (sparx5):
         - separate explicit and implicit traffic forwarding rules, make
           the implicit rules always active
         - add support for egress DSCP rewrite
         - IS0 VCAP support (Ingress Classification)
         - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS
           etc.)
         - ES2 VCAP support (Egress Access Control)
         - support for Per-Stream Filtering and Policing (802.1Q,
           8.6.5.1)

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - add MAB (port auth) offload support
         - enable PTP receive for mv88e6390
      - NXP (ocelot):
         - support MAC Merge layer
         - support for the the vsc7512 internal copper phys
      - Microchip:
         - lan9303: convert to PHYLINK
         - lan966x: support TC flower filter statistics
         - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x
         - lan937x: support Credit Based Shaper configuration
         - ksz9477: support Energy Efficient Ethernet
      - other:
         - qca8k: convert to regmap read/write API, use bulk operations
         - rswitch: Improve TX timestamp accuracy

   - Intel WiFi (iwlwifi):
      - EHT (Wi-Fi 7) rate reporting
      - STEP equalizer support: transfer some STEP (connection to radio
        on platforms with integrated wifi) related parameters from the
        BIOS to the firmware.

   - Qualcomm 802.11ax WiFi (ath11k):
      - IPQ5018 support
      - Fine Timing Measurement (FTM) responder role support
      - channel 177 support

   - MediaTek WiFi (mt76):
      - per-PHY LED support
      - mt7996: EHT (Wi-Fi 7) support
      - Wireless Ethernet Dispatch (WED) reset support
      - switch to using page pool allocator

   - RealTek WiFi (rtw89):
      - support new version of Bluetooth co-existance

   - Mobile:
      - rmnet: support TX aggregation"

* tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits)
  page_pool: add a comment explaining the fragment counter usage
  net: ethtool: fix __ethtool_dev_mm_supported() implementation
  ethtool: pse-pd: Fix double word in comments
  xsk: add linux/vmalloc.h to xsk.c
  sefltests: netdevsim: wait for devlink instance after netns removal
  selftest: fib_tests: Always cleanup before exit
  net/mlx5e: Align IPsec ASO result memory to be as required by hardware
  net/mlx5e: TC, Set CT miss to the specific ct action instance
  net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG
  net/mlx5: Refactor tc miss handling to a single function
  net/mlx5: Kconfig: Make tc offload depend on tc skb extension
  net/sched: flower: Support hardware miss to tc action
  net/sched: flower: Move filter handle initialization earlier
  net/sched: cls_api: Support hardware miss to tc action
  net/sched: Rename user cookie and act cookie
  sfc: fix builds without CONFIG_RTC_LIB
  sfc: clean up some inconsistent indentings
  net/mlx4_en: Introduce flexible array to silence overflow warning
  net: lan966x: Fix possible deadlock inside PTP
  net/ulp: Remove redundant ->clone() test in inet_clone_ulp().
  ...

1 files changed, 851 insertions, 0 deletions

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
new file mode 100644
index 000000000..a089b704b
--- /dev/null
+++ b/net/core/netpoll.c
@@ -0,0 +1,851 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Common framework for low-level network console, dump, and debugger code
+ *
+ * Sep 8 2003  Matt Mackall <mpm@selenic.com>
+ *
+ * based on the netconsole code from:
+ *
+ * Copyright (C) 2001  Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2002  Red Hat, Inc.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/moduleparam.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/string.h>
+#include <linux/if_arp.h>
+#include <linux/inetdevice.h>
+#include <linux/inet.h>
+#include <linux/interrupt.h>
+#include <linux/netpoll.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/rcupdate.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+#include <linux/export.h>
+#include <linux/if_vlan.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/addrconf.h>
+#include <net/ndisc.h>
+#include <net/ip6_checksum.h>
+#include <asm/unaligned.h>
+#include <trace/events/napi.h>
+#include <linux/kconfig.h>
+
+/*
+ * We maintain a small pool of fully-sized skbs, to make sure the
+ * message gets out even in extreme OOM situations.
+ */
+
+#define MAX_UDP_CHUNK 1460
+#define MAX_SKBS 32
+
+static struct sk_buff_head skb_pool;
+
+DEFINE_STATIC_SRCU(netpoll_srcu);
+
+#define USEC_PER_POLL	50
+
+#define MAX_SKB_SIZE							\
+	(sizeof(struct ethhdr) +					\
+	 sizeof(struct iphdr) +						\
+	 sizeof(struct udphdr) +					\
+	 MAX_UDP_CHUNK)
+
+static void zap_completion_queue(void);
+
+static unsigned int carrier_timeout = 4;
+module_param(carrier_timeout, uint, 0644);
+
+#define np_info(np, fmt, ...)				\
+	pr_info("%s: " fmt, np->name, ##__VA_ARGS__)
+#define np_err(np, fmt, ...)				\
+	pr_err("%s: " fmt, np->name, ##__VA_ARGS__)
+#define np_notice(np, fmt, ...)				\
+	pr_notice("%s: " fmt, np->name, ##__VA_ARGS__)
+
+static netdev_tx_t netpoll_start_xmit(struct sk_buff *skb,
+				      struct net_device *dev,
+				      struct netdev_queue *txq)
+{
+	netdev_tx_t status = NETDEV_TX_OK;
+	netdev_features_t features;
+
+	features = netif_skb_features(skb);
+
+	if (skb_vlan_tag_present(skb) &&
+	    !vlan_hw_offload_capable(features, skb->vlan_proto)) {
+		skb = __vlan_hwaccel_push_inside(skb);
+		if (unlikely(!skb)) {
+			/* This is actually a packet drop, but we
+			 * don't want the code that calls this
+			 * function to try and operate on a NULL skb.
+			 */
+			goto out;
+		}
+	}
+
+	status = netdev_start_xmit(skb, dev, txq, false);
+
+out:
+	return status;
+}
+
+static void queue_process(struct work_struct *work)
+{
+	struct netpoll_info *npinfo =
+		container_of(work, struct netpoll_info, tx_work.work);
+	struct sk_buff *skb;
+	unsigned long flags;
+
+	while ((skb = skb_dequeue(&npinfo->txq))) {
+		struct net_device *dev = skb->dev;
+		struct netdev_queue *txq;
+		unsigned int q_index;
+
+		if (!netif_device_present(dev) || !netif_running(dev)) {
+			kfree_skb(skb);
+			continue;
+		}
+
+		local_irq_save(flags);
+		/* check if skb->queue_mapping is still valid */
+		q_index = skb_get_queue_mapping(skb);
+		if (unlikely(q_index >= dev->real_num_tx_queues)) {
+			q_index = q_index % dev->real_num_tx_queues;
+			skb_set_queue_mapping(skb, q_index);
+		}
+		txq = netdev_get_tx_queue(dev, q_index);
+		HARD_TX_LOCK(dev, txq, smp_processor_id());
+		if (netif_xmit_frozen_or_stopped(txq) ||
+		    !dev_xmit_complete(netpoll_start_xmit(skb, dev, txq))) {
+			skb_queue_head(&npinfo->txq, skb);
+			HARD_TX_UNLOCK(dev, txq);
+			local_irq_restore(flags);
+
+			schedule_delayed_work(&npinfo->tx_work, HZ/10);
+			return;
+		}
+		HARD_TX_UNLOCK(dev, txq);
+		local_irq_restore(flags);
+	}
+}
+
+static void poll_one_napi(struct napi_struct *napi)
+{
+	int work;
+
+	/* If we set this bit but see that it has already been set,
+	 * that indicates that napi has been disabled and we need
+	 * to abort this operation
+	 */
+	if (test_and_set_bit(NAPI_STATE_NPSVC, &napi->state))
+		return;
+
+	/* We explicilty pass the polling call a budget of 0 to
+	 * indicate that we are clearing the Tx path only.
+	 */
+	work = napi->poll(napi, 0);
+	WARN_ONCE(work, "%pS exceeded budget in poll\n", napi->poll);
+	trace_napi_poll(napi, work, 0);
+
+	clear_bit(NAPI_STATE_NPSVC, &napi->state);
+}
+
+static void poll_napi(struct net_device *dev)
+{
+	struct napi_struct *napi;
+	int cpu = smp_processor_id();
+
+	list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
+		if (cmpxchg(&napi->poll_owner, -1, cpu) == -1) {
+			poll_one_napi(napi);
+			smp_store_release(&napi->poll_owner, -1);
+		}
+	}
+}
+
+void netpoll_poll_dev(struct net_device *dev)
+{
+	struct netpoll_info *ni = rcu_dereference_bh(dev->npinfo);
+	const struct net_device_ops *ops;
+
+	/* Don't do any rx activity if the dev_lock mutex is held
+	 * the dev_open/close paths use this to block netpoll activity
+	 * while changing device state
+	 */
+	if (!ni || down_trylock(&ni->dev_lock))
+		return;
+
+	if (!netif_running(dev)) {
+		up(&ni->dev_lock);
+		return;
+	}
+
+	ops = dev->netdev_ops;
+	if (ops->ndo_poll_controller)
+		ops->ndo_poll_controller(dev);
+
+	poll_napi(dev);
+
+	up(&ni->dev_lock);
+
+	zap_completion_queue();
+}
+EXPORT_SYMBOL(netpoll_poll_dev);
+
+void netpoll_poll_disable(struct net_device *dev)
+{
+	struct netpoll_info *ni;
+	int idx;
+	might_sleep();
+	idx = srcu_read_lock(&netpoll_srcu);
+	ni = srcu_dereference(dev->npinfo, &netpoll_srcu);
+	if (ni)
+		down(&ni->dev_lock);
+	srcu_read_unlock(&netpoll_srcu, idx);
+}
+EXPORT_SYMBOL(netpoll_poll_disable);
+
+void netpoll_poll_enable(struct net_device *dev)
+{
+	struct netpoll_info *ni;
+	rcu_read_lock();
+	ni = rcu_dereference(dev->npinfo);
+	if (ni)
+		up(&ni->dev_lock);
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(netpoll_poll_enable);
+
+static void refill_skbs(void)
+{
+	struct sk_buff *skb;
+	unsigned long flags;
+
+	spin_lock_irqsave(&skb_pool.lock, flags);
+	while (skb_pool.qlen < MAX_SKBS) {
+		skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC);
+		if (!skb)
+			break;
+
+		__skb_queue_tail(&skb_pool, skb);
+	}
+	spin_unlock_irqrestore(&skb_pool.lock, flags);
+}
+
+static void zap_completion_queue(void)
+{
+	unsigned long flags;
+	struct softnet_data *sd = &get_cpu_var(softnet_data);
+
+	if (sd->completion_queue) {
+		struct sk_buff *clist;
+
+		local_irq_save(flags);
+		clist = sd->completion_queue;
+		sd->completion_queue = NULL;
+		local_irq_restore(flags);
+
+		while (clist != NULL) {
+			struct sk_buff *skb = clist;
+			clist = clist->next;
+			if (!skb_irq_freeable(skb)) {
+				refcount_set(&skb->users, 1);
+				dev_kfree_skb_any(skb); /* put this one back */
+			} else {
+				__kfree_skb(skb);
+			}
+		}
+	}
+
+	put_cpu_var(softnet_data);
+}
+
+static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve)
+{
+	int count = 0;
+	struct sk_buff *skb;
+
+	zap_completion_queue();
+	refill_skbs();
+repeat:
+
+	skb = alloc_skb(len, GFP_ATOMIC);
+	if (!skb)
+		skb = skb_dequeue(&skb_pool);
+
+	if (!skb) {
+		if (++count < 10) {
+			netpoll_poll_dev(np->dev);
+			goto repeat;
+		}
+		return NULL;
+	}
+
+	refcount_set(&skb->users, 1);
+	skb_reserve(skb, reserve);
+	return skb;
+}
+
+static int netpoll_owner_active(struct net_device *dev)
+{
+	struct napi_struct *napi;
+
+	list_for_each_entry_rcu(napi, &dev->napi_list, dev_list) {
+		if (napi->poll_owner == smp_processor_id())
+			return 1;
+	}
+	return 0;
+}
+
+/* call with IRQ disabled */
+static netdev_tx_t __netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
+{
+	netdev_tx_t status = NETDEV_TX_BUSY;
+	struct net_device *dev;
+	unsigned long tries;
+	/* It is up to the caller to keep npinfo alive. */
+	struct netpoll_info *npinfo;
+
+	lockdep_assert_irqs_disabled();
+
+	dev = np->dev;
+	npinfo = rcu_dereference_bh(dev->npinfo);
+
+	if (!npinfo || !netif_running(dev) || !netif_device_present(dev)) {
+		dev_kfree_skb_irq(skb);
+		return NET_XMIT_DROP;
+	}
+
+	/* don't get messages out of order, and no recursion */
+	if (skb_queue_len(&npinfo->txq) == 0 && !netpoll_owner_active(dev)) {
+		struct netdev_queue *txq;
+
+		txq = netdev_core_pick_tx(dev, skb, NULL);
+
+		/* try until next clock tick */
+		for (tries = jiffies_to_usecs(1)/USEC_PER_POLL;
+		     tries > 0; --tries) {
+			if (HARD_TX_TRYLOCK(dev, txq)) {
+				if (!netif_xmit_stopped(txq))
+					status = netpoll_start_xmit(skb, dev, txq);
+
+				HARD_TX_UNLOCK(dev, txq);
+
+				if (dev_xmit_complete(status))
+					break;
+
+			}
+
+			/* tickle device maybe there is some cleanup */
+			netpoll_poll_dev(np->dev);
+
+			udelay(USEC_PER_POLL);
+		}
+
+		WARN_ONCE(!irqs_disabled(),
+			"netpoll_send_skb_on_dev(): %s enabled interrupts in poll (%pS)\n",
+			dev->name, dev->netdev_ops->ndo_start_xmit);
+
+	}
+
+	if (!dev_xmit_complete(status)) {
+		skb_queue_tail(&npinfo->txq, skb);
+		schedule_delayed_work(&npinfo->tx_work,0);
+	}
+	return NETDEV_TX_OK;
+}
+
+netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
+{
+	unsigned long flags;
+	netdev_tx_t ret;
+
+	if (unlikely(!np)) {
+		dev_kfree_skb_irq(skb);
+		ret = NET_XMIT_DROP;
+	} else {
+		local_irq_save(flags);
+		ret = __netpoll_send_skb(np, skb);
+		local_irq_restore(flags);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(netpoll_send_skb);
+
+void netpoll_send_udp(struct netpoll *np, const char *msg, int len)
+{
+	int total_len, ip_len, udp_len;
+	struct sk_buff *skb;
+	struct udphdr *udph;
+	struct iphdr *iph;
+	struct ethhdr *eth;
+	static atomic_t ip_ident;
+	struct ipv6hdr *ip6h;
+
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		WARN_ON_ONCE(!irqs_disabled());
+
+	udp_len = len + sizeof(*udph);
+	if (np->ipv6)
+		ip_len = udp_len + sizeof(*ip6h);
+	else
+		ip_len = udp_len + sizeof(*iph);
+
+	total_len = ip_len + LL_RESERVED_SPACE(np->dev);
+
+	skb = find_skb(np, total_len + np->dev->needed_tailroom,
+		       total_len - len);
+	if (!skb)
+		return;
+
+	skb_copy_to_linear_data(skb, msg, len);
+	skb_put(skb, len);
+
+	skb_push(skb, sizeof(*udph));
+	skb_reset_transport_header(skb);
+	udph = udp_hdr(skb);
+	udph->source = htons(np->local_port);
+	udph->dest = htons(np->remote_port);
+	udph->len = htons(udp_len);
+
+	if (np->ipv6) {
+		udph->check = 0;
+		udph->check = csum_ipv6_magic(&np->local_ip.in6,
+					      &np->remote_ip.in6,
+					      udp_len, IPPROTO_UDP,
+					      csum_partial(udph, udp_len, 0));
+		if (udph->check == 0)
+			udph->check = CSUM_MANGLED_0;
+
+		skb_push(skb, sizeof(*ip6h));
+		skb_reset_network_header(skb);
+		ip6h = ipv6_hdr(skb);
+
+		/* ip6h->version = 6; ip6h->priority = 0; */
+		*(unsigned char *)ip6h = 0x60;
+		ip6h->flow_lbl[0] = 0;
+		ip6h->flow_lbl[1] = 0;
+		ip6h->flow_lbl[2] = 0;
+
+		ip6h->payload_len = htons(sizeof(struct udphdr) + len);
+		ip6h->nexthdr = IPPROTO_UDP;
+		ip6h->hop_limit = 32;
+		ip6h->saddr = np->local_ip.in6;
+		ip6h->daddr = np->remote_ip.in6;
+
+		eth = skb_push(skb, ETH_HLEN);
+		skb_reset_mac_header(skb);
+		skb->protocol = eth->h_proto = htons(ETH_P_IPV6);
+	} else {
+		udph->check = 0;
+		udph->check = csum_tcpudp_magic(np->local_ip.ip,
+						np->remote_ip.ip,
+						udp_len, IPPROTO_UDP,
+						csum_partial(udph, udp_len, 0));
+		if (udph->check == 0)
+			udph->check = CSUM_MANGLED_0;
+
+		skb_push(skb, sizeof(*iph));
+		skb_reset_network_header(skb);
+		iph = ip_hdr(skb);
+
+		/* iph->version = 4; iph->ihl = 5; */
+		*(unsigned char *)iph = 0x45;
+		iph->tos      = 0;
+		put_unaligned(htons(ip_len), &(iph->tot_len));
+		iph->id       = htons(atomic_inc_return(&ip_ident));
+		iph->frag_off = 0;
+		iph->ttl      = 64;
+		iph->protocol = IPPROTO_UDP;
+		iph->check    = 0;
+		put_unaligned(np->local_ip.ip, &(iph->saddr));
+		put_unaligned(np->remote_ip.ip, &(iph->daddr));
+		iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
+
+		eth = skb_push(skb, ETH_HLEN);
+		skb_reset_mac_header(skb);
+		skb->protocol = eth->h_proto = htons(ETH_P_IP);
+	}
+
+	ether_addr_copy(eth->h_source, np->dev->dev_addr);
+	ether_addr_copy(eth->h_dest, np->remote_mac);
+
+	skb->dev = np->dev;
+
+	netpoll_send_skb(np, skb);
+}
+EXPORT_SYMBOL(netpoll_send_udp);
+
+void netpoll_print_options(struct netpoll *np)
+{
+	np_info(np, "local port %d\n", np->local_port);
+	if (np->ipv6)
+		np_info(np, "local IPv6 address %pI6c\n", &np->local_ip.in6);
+	else
+		np_info(np, "local IPv4 address %pI4\n", &np->local_ip.ip);
+	np_info(np, "interface '%s'\n", np->dev_name);
+	np_info(np, "remote port %d\n", np->remote_port);
+	if (np->ipv6)
+		np_info(np, "remote IPv6 address %pI6c\n", &np->remote_ip.in6);
+	else
+		np_info(np, "remote IPv4 address %pI4\n", &np->remote_ip.ip);
+	np_info(np, "remote ethernet address %pM\n", np->remote_mac);
+}
+EXPORT_SYMBOL(netpoll_print_options);
+
+static int netpoll_parse_ip_addr(const char *str, union inet_addr *addr)
+{
+	const char *end;
+
+	if (!strchr(str, ':') &&
+	    in4_pton(str, -1, (void *)addr, -1, &end) > 0) {
+		if (!*end)
+			return 0;
+	}
+	if (in6_pton(str, -1, addr->in6.s6_addr, -1, &end) > 0) {
+#if IS_ENABLED(CONFIG_IPV6)
+		if (!*end)
+			return 1;
+#else
+		return -1;
+#endif
+	}
+	return -1;
+}
+
+int netpoll_parse_options(struct netpoll *np, char *opt)
+{
+	char *cur=opt, *delim;
+	int ipv6;
+	bool ipversion_set = false;
+
+	if (*cur != '@') {
+		if ((delim = strchr(cur, '@')) == NULL)
+			goto parse_failed;
+		*delim = 0;
+		if (kstrtou16(cur, 10, &np->local_port))
+			goto parse_failed;
+		cur = delim;
+	}
+	cur++;
+
+	if (*cur != '/') {
+		ipversion_set = true;
+		if ((delim = strchr(cur, '/')) == NULL)
+			goto parse_failed;
+		*delim = 0;
+		ipv6 = netpoll_parse_ip_addr(cur, &np->local_ip);
+		if (ipv6 < 0)
+			goto parse_failed;
+		else
+			np->ipv6 = (bool)ipv6;
+		cur = delim;
+	}
+	cur++;
+
+	if (*cur != ',') {
+		/* parse out dev name */
+		if ((delim = strchr(cur, ',')) == NULL)
+			goto parse_failed;
+		*delim = 0;
+		strscpy(np->dev_name, cur, sizeof(np->dev_name));
+		cur = delim;
+	}
+	cur++;
+
+	if (*cur != '@') {
+		/* dst port */
+		if ((delim = strchr(cur, '@')) == NULL)
+			goto parse_failed;
+		*delim = 0;
+		if (*cur == ' ' || *cur == '\t')
+			np_info(np, "warning: whitespace is not allowed\n");
+		if (kstrtou16(cur, 10, &np->remote_port))
+			goto parse_failed;
+		cur = delim;
+	}
+	cur++;
+
+	/* dst ip */
+	if ((delim = strchr(cur, '/')) == NULL)
+		goto parse_failed;
+	*delim = 0;
+	ipv6 = netpoll_parse_ip_addr(cur, &np->remote_ip);
+	if (ipv6 < 0)
+		goto parse_failed;
+	else if (ipversion_set && np->ipv6 != (bool)ipv6)
+		goto parse_failed;
+	else
+		np->ipv6 = (bool)ipv6;
+	cur = delim + 1;
+
+	if (*cur != 0) {
+		/* MAC address */
+		if (!mac_pton(cur, np->remote_mac))
+			goto parse_failed;
+	}
+
+	netpoll_print_options(np);
+
+	return 0;
+
+ parse_failed:
+	np_info(np, "couldn't parse config at '%s'!\n", cur);
+	return -1;
+}
+EXPORT_SYMBOL(netpoll_parse_options);
+
+int __netpoll_setup(struct netpoll *np, struct net_device *ndev)
+{
+	struct netpoll_info *npinfo;
+	const struct net_device_ops *ops;
+	int err;
+
+	np->dev = ndev;
+	strscpy(np->dev_name, ndev->name, IFNAMSIZ);
+
+	if (ndev->priv_flags & IFF_DISABLE_NETPOLL) {
+		np_err(np, "%s doesn't support polling, aborting\n",
+		       np->dev_name);
+		err = -ENOTSUPP;
+		goto out;
+	}
+
+	if (!ndev->npinfo) {
+		npinfo = kmalloc(sizeof(*npinfo), GFP_KERNEL);
+		if (!npinfo) {
+			err = -ENOMEM;
+			goto out;
+		}
+
+		sema_init(&npinfo->dev_lock, 1);
+		skb_queue_head_init(&npinfo->txq);
+		INIT_DELAYED_WORK(&npinfo->tx_work, queue_process);
+
+		refcount_set(&npinfo->refcnt, 1);
+
+		ops = np->dev->netdev_ops;
+		if (ops->ndo_netpoll_setup) {
+			err = ops->ndo_netpoll_setup(ndev, npinfo);
+			if (err)
+				goto free_npinfo;
+		}
+	} else {
+		npinfo = rtnl_dereference(ndev->npinfo);
+		refcount_inc(&npinfo->refcnt);
+	}
+
+	npinfo->netpoll = np;
+
+	/* last thing to do is link it to the net device structure */
+	rcu_assign_pointer(ndev->npinfo, npinfo);
+
+	return 0;
+
+free_npinfo:
+	kfree(npinfo);
+out:
+	return err;
+}
+EXPORT_SYMBOL_GPL(__netpoll_setup);
+
+int netpoll_setup(struct netpoll *np)
+{
+	struct net_device *ndev = NULL;
+	struct in_device *in_dev;
+	int err;
+
+	rtnl_lock();
+	if (np->dev_name[0]) {
+		struct net *net = current->nsproxy->net_ns;
+		ndev = __dev_get_by_name(net, np->dev_name);
+	}
+	if (!ndev) {
+		np_err(np, "%s doesn't exist, aborting\n", np->dev_name);
+		err = -ENODEV;
+		goto unlock;
+	}
+	dev_hold(ndev);
+
+	if (netdev_master_upper_dev_get(ndev)) {
+		np_err(np, "%s is a slave device, aborting\n", np->dev_name);
+		err = -EBUSY;
+		goto put;
+	}
+
+	if (!netif_running(ndev)) {
+		unsigned long atmost;
+
+		np_info(np, "device %s not up yet, forcing it\n", np->dev_name);
+
+		err = dev_open(ndev, NULL);
+
+		if (err) {
+			np_err(np, "failed to open %s\n", ndev->name);
+			goto put;
+		}
+
+		rtnl_unlock();
+		atmost = jiffies + carrier_timeout * HZ;
+		while (!netif_carrier_ok(ndev)) {
+			if (time_after(jiffies, atmost)) {
+				np_notice(np, "timeout waiting for carrier\n");
+				break;
+			}
+			msleep(1);
+		}
+
+		rtnl_lock();
+	}
+
+	if (!np->local_ip.ip) {
+		if (!np->ipv6) {
+			const struct in_ifaddr *ifa;
+
+			in_dev = __in_dev_get_rtnl(ndev);
+			if (!in_dev)
+				goto put_noaddr;
+
+			ifa = rtnl_dereference(in_dev->ifa_list);
+			if (!ifa) {
+put_noaddr:
+				np_err(np, "no IP address for %s, aborting\n",
+				       np->dev_name);
+				err = -EDESTADDRREQ;
+				goto put;
+			}
+
+			np->local_ip.ip = ifa->ifa_local;
+			np_info(np, "local IP %pI4\n", &np->local_ip.ip);
+		} else {
+#if IS_ENABLED(CONFIG_IPV6)
+			struct inet6_dev *idev;
+
+			err = -EDESTADDRREQ;
+			idev = __in6_dev_get(ndev);
+			if (idev) {
+				struct inet6_ifaddr *ifp;
+
+				read_lock_bh(&idev->lock);
+				list_for_each_entry(ifp, &idev->addr_list, if_list) {
+					if (!!(ipv6_addr_type(&ifp->addr) & IPV6_ADDR_LINKLOCAL) !=
+					    !!(ipv6_addr_type(&np->remote_ip.in6) & IPV6_ADDR_LINKLOCAL))
+						continue;
+					np->local_ip.in6 = ifp->addr;
+					err = 0;
+					break;
+				}
+				read_unlock_bh(&idev->lock);
+			}
+			if (err) {
+				np_err(np, "no IPv6 address for %s, aborting\n",
+				       np->dev_name);
+				goto put;
+			} else
+				np_info(np, "local IPv6 %pI6c\n", &np->local_ip.in6);
+#else
+			np_err(np, "IPv6 is not supported %s, aborting\n",
+			       np->dev_name);
+			err = -EINVAL;
+			goto put;
+#endif
+		}
+	}
+
+	/* fill up the skb queue */
+	refill_skbs();
+
+	err = __netpoll_setup(np, ndev);
+	if (err)
+		goto put;
+	netdev_tracker_alloc(ndev, &np->dev_tracker, GFP_KERNEL);
+	rtnl_unlock();
+	return 0;
+
+put:
+	dev_put(ndev);
+unlock:
+	rtnl_unlock();
+	return err;
+}
+EXPORT_SYMBOL(netpoll_setup);
+
+static int __init netpoll_init(void)
+{
+	skb_queue_head_init(&skb_pool);
+	return 0;
+}
+core_initcall(netpoll_init);
+
+static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head)
+{
+	struct netpoll_info *npinfo =
+			container_of(rcu_head, struct netpoll_info, rcu);
+
+	skb_queue_purge(&npinfo->txq);
+
+	/* we can't call cancel_delayed_work_sync here, as we are in softirq */
+	cancel_delayed_work(&npinfo->tx_work);
+
+	/* clean after last, unfinished work */
+	__skb_queue_purge(&npinfo->txq);
+	/* now cancel it again */
+	cancel_delayed_work(&npinfo->tx_work);
+	kfree(npinfo);
+}
+
+void __netpoll_cleanup(struct netpoll *np)
+{
+	struct netpoll_info *npinfo;
+
+	npinfo = rtnl_dereference(np->dev->npinfo);
+	if (!npinfo)
+		return;
+
+	synchronize_srcu(&netpoll_srcu);
+
+	if (refcount_dec_and_test(&npinfo->refcnt)) {
+		const struct net_device_ops *ops;
+
+		ops = np->dev->netdev_ops;
+		if (ops->ndo_netpoll_cleanup)
+			ops->ndo_netpoll_cleanup(np->dev);
+
+		RCU_INIT_POINTER(np->dev->npinfo, NULL);
+		call_rcu(&npinfo->rcu, rcu_cleanup_netpoll_info);
+	} else
+		RCU_INIT_POINTER(np->dev->npinfo, NULL);
+}
+EXPORT_SYMBOL_GPL(__netpoll_cleanup);
+
+void __netpoll_free(struct netpoll *np)
+{
+	ASSERT_RTNL();
+
+	/* Wait for transmitting packets to finish before freeing. */
+	synchronize_rcu();
+	__netpoll_cleanup(np);
+	kfree(np);
+}
+EXPORT_SYMBOL_GPL(__netpoll_free);
+
+void netpoll_cleanup(struct netpoll *np)
+{
+	rtnl_lock();
+	if (!np->dev)
+		goto out;
+	__netpoll_cleanup(np);
+	netdev_put(np->dev, &np->dev_tracker);
+	np->dev = NULL;
+out:
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(netpoll_cleanup);