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().
  ...

7 files changed, 704 insertions, 0 deletions

diff --git a/arch/um/os-Linux/drivers/Makefile b/arch/um/os-Linux/drivers/Makefile
new file mode 100644
index 000000000..d79e75f1b
--- /dev/null
+++ b/arch/um/os-Linux/drivers/Makefile
@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+# 
+# Copyright (C) 2000, 2002 Jeff Dike (jdike@karaya.com)
+#
+
+ethertap-objs := ethertap_kern.o ethertap_user.o
+tuntap-objs := tuntap_kern.o tuntap_user.o
+
+obj-y = 
+obj-$(CONFIG_UML_NET_ETHERTAP) += ethertap.o
+obj-$(CONFIG_UML_NET_TUNTAP) += tuntap.o
+
+include arch/um/scripts/Makefile.rules
diff --git a/arch/um/os-Linux/drivers/etap.h b/arch/um/os-Linux/drivers/etap.h
new file mode 100644
index 000000000..a475259f9
--- /dev/null
+++ b/arch/um/os-Linux/drivers/etap.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __DRIVERS_ETAP_H
+#define __DRIVERS_ETAP_H
+
+#include <net_user.h>
+
+struct ethertap_data {
+	char *dev_name;
+	char *gate_addr;
+	int data_fd;
+	int control_fd;
+	void *dev;
+};
+
+extern const struct net_user_info ethertap_user_info;
+
+#endif
diff --git a/arch/um/os-Linux/drivers/ethertap_kern.c b/arch/um/os-Linux/drivers/ethertap_kern.c
new file mode 100644
index 000000000..3182e759d
--- /dev/null
+++ b/arch/um/os-Linux/drivers/ethertap_kern.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
+ * James Leu (jleu@mindspring.net).
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright (C) 2001 by various other people who didn't put their name here.
+ */
+
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include "etap.h"
+#include <net_kern.h>
+
+struct ethertap_init {
+	char *dev_name;
+	char *gate_addr;
+};
+
+static void etap_init(struct net_device *dev, void *data)
+{
+	struct uml_net_private *pri;
+	struct ethertap_data *epri;
+	struct ethertap_init *init = data;
+
+	pri = netdev_priv(dev);
+	epri = (struct ethertap_data *) pri->user;
+	epri->dev_name = init->dev_name;
+	epri->gate_addr = init->gate_addr;
+	epri->data_fd = -1;
+	epri->control_fd = -1;
+	epri->dev = dev;
+
+	printk(KERN_INFO "ethertap backend - %s", epri->dev_name);
+	if (epri->gate_addr != NULL)
+		printk(KERN_CONT ", IP = %s", epri->gate_addr);
+	printk(KERN_CONT "\n");
+}
+
+static int etap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+	int len;
+
+	len = net_recvfrom(fd, skb_mac_header(skb),
+			   skb->dev->mtu + 2 + ETH_HEADER_ETHERTAP);
+	if (len <= 0)
+		return(len);
+
+	skb_pull(skb, 2);
+	len -= 2;
+	return len;
+}
+
+static int etap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+	skb_push(skb, 2);
+	return net_send(fd, skb->data, skb->len);
+}
+
+const struct net_kern_info ethertap_kern_info = {
+	.init			= etap_init,
+	.protocol		= eth_protocol,
+	.read			= etap_read,
+	.write 			= etap_write,
+};
+
+int ethertap_setup(char *str, char **mac_out, void *data)
+{
+	struct ethertap_init *init = data;
+
+	*init = ((struct ethertap_init)
+		{ .dev_name 	= NULL,
+		  .gate_addr 	= NULL });
+	if (tap_setup_common(str, "ethertap", &init->dev_name, mac_out,
+			    &init->gate_addr))
+		return 0;
+	if (init->dev_name == NULL) {
+		printk(KERN_ERR "ethertap_setup : Missing tap device name\n");
+		return 0;
+	}
+
+	return 1;
+}
+
+static struct transport ethertap_transport = {
+	.list 		= LIST_HEAD_INIT(ethertap_transport.list),
+	.name 		= "ethertap",
+	.setup  	= ethertap_setup,
+	.user 		= &ethertap_user_info,
+	.kern 		= &ethertap_kern_info,
+	.private_size 	= sizeof(struct ethertap_data),
+	.setup_size 	= sizeof(struct ethertap_init),
+};
+
+static int register_ethertap(void)
+{
+	register_transport(&ethertap_transport);
+	return 0;
+}
+
+late_initcall(register_ethertap);
diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
new file mode 100644
index 000000000..9483021d8
--- /dev/null
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
+ * James Leu (jleu@mindspring.net).
+ * Copyright (C) 2001 by various other people who didn't put their name here.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include "etap.h"
+#include <os.h>
+#include <net_user.h>
+#include <um_malloc.h>
+
+#define MAX_PACKET ETH_MAX_PACKET
+
+static int etap_user_init(void *data, void *dev)
+{
+	struct ethertap_data *pri = data;
+
+	pri->dev = dev;
+	return 0;
+}
+
+struct addr_change {
+	enum { ADD_ADDR, DEL_ADDR } what;
+	unsigned char addr[4];
+	unsigned char netmask[4];
+};
+
+static void etap_change(int op, unsigned char *addr, unsigned char *netmask,
+			int fd)
+{
+	struct addr_change change;
+	char *output;
+	int n;
+
+	change.what = op;
+	memcpy(change.addr, addr, sizeof(change.addr));
+	memcpy(change.netmask, netmask, sizeof(change.netmask));
+	CATCH_EINTR(n = write(fd, &change, sizeof(change)));
+	if (n != sizeof(change)) {
+		printk(UM_KERN_ERR "etap_change - request failed, err = %d\n",
+		       errno);
+		return;
+	}
+
+	output = uml_kmalloc(UM_KERN_PAGE_SIZE, UM_GFP_KERNEL);
+	if (output == NULL)
+		printk(UM_KERN_ERR "etap_change : Failed to allocate output "
+		       "buffer\n");
+	read_output(fd, output, UM_KERN_PAGE_SIZE);
+	if (output != NULL) {
+		printk("%s", output);
+		kfree(output);
+	}
+}
+
+static void etap_open_addr(unsigned char *addr, unsigned char *netmask,
+			   void *arg)
+{
+	etap_change(ADD_ADDR, addr, netmask, *((int *) arg));
+}
+
+static void etap_close_addr(unsigned char *addr, unsigned char *netmask,
+			    void *arg)
+{
+	etap_change(DEL_ADDR, addr, netmask, *((int *) arg));
+}
+
+struct etap_pre_exec_data {
+	int control_remote;
+	int control_me;
+	int data_me;
+};
+
+static void etap_pre_exec(void *arg)
+{
+	struct etap_pre_exec_data *data = arg;
+
+	dup2(data->control_remote, 1);
+	close(data->data_me);
+	close(data->control_me);
+}
+
+static int etap_tramp(char *dev, char *gate, int control_me,
+		      int control_remote, int data_me, int data_remote)
+{
+	struct etap_pre_exec_data pe_data;
+	int pid, err, n;
+	char version_buf[sizeof("nnnnn\0")];
+	char data_fd_buf[sizeof("nnnnnn\0")];
+	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
+	char *setup_args[] = { "uml_net", version_buf, "ethertap", dev,
+			       data_fd_buf, gate_buf, NULL };
+	char *nosetup_args[] = { "uml_net", version_buf, "ethertap",
+				 dev, data_fd_buf, NULL };
+	char **args, c;
+
+	sprintf(data_fd_buf, "%d", data_remote);
+	sprintf(version_buf, "%d", UML_NET_VERSION);
+	if (gate != NULL) {
+		strncpy(gate_buf, gate, 15);
+		args = setup_args;
+	}
+	else args = nosetup_args;
+
+	err = 0;
+	pe_data.control_remote = control_remote;
+	pe_data.control_me = control_me;
+	pe_data.data_me = data_me;
+	pid = run_helper(etap_pre_exec, &pe_data, args);
+
+	if (pid < 0)
+		err = pid;
+	close(data_remote);
+	close(control_remote);
+	CATCH_EINTR(n = read(control_me, &c, sizeof(c)));
+	if (n != sizeof(c)) {
+		err = -errno;
+		printk(UM_KERN_ERR "etap_tramp : read of status failed, "
+		       "err = %d\n", -err);
+		return err;
+	}
+	if (c != 1) {
+		printk(UM_KERN_ERR "etap_tramp : uml_net failed\n");
+		err = helper_wait(pid);
+	}
+	return err;
+}
+
+static int etap_open(void *data)
+{
+	struct ethertap_data *pri = data;
+	char *output;
+	int data_fds[2], control_fds[2], err, output_len;
+
+	err = tap_open_common(pri->dev, pri->gate_addr);
+	if (err)
+		return err;
+
+	err = socketpair(AF_UNIX, SOCK_DGRAM, 0, data_fds);
+	if (err) {
+		err = -errno;
+		printk(UM_KERN_ERR "etap_open - data socketpair failed - "
+		       "err = %d\n", errno);
+		return err;
+	}
+
+	err = socketpair(AF_UNIX, SOCK_STREAM, 0, control_fds);
+	if (err) {
+		err = -errno;
+		printk(UM_KERN_ERR "etap_open - control socketpair failed - "
+		       "err = %d\n", errno);
+		goto out_close_data;
+	}
+
+	err = etap_tramp(pri->dev_name, pri->gate_addr, control_fds[0],
+			 control_fds[1], data_fds[0], data_fds[1]);
+	output_len = UM_KERN_PAGE_SIZE;
+	output = uml_kmalloc(output_len, UM_GFP_KERNEL);
+	read_output(control_fds[0], output, output_len);
+
+	if (output == NULL)
+		printk(UM_KERN_ERR "etap_open : failed to allocate output "
+		       "buffer\n");
+	else {
+		printk("%s", output);
+		kfree(output);
+	}
+
+	if (err < 0) {
+		printk(UM_KERN_ERR "etap_tramp failed - err = %d\n", -err);
+		goto out_close_control;
+	}
+
+	pri->data_fd = data_fds[0];
+	pri->control_fd = control_fds[0];
+	iter_addresses(pri->dev, etap_open_addr, &pri->control_fd);
+	return data_fds[0];
+
+out_close_control:
+	close(control_fds[0]);
+	close(control_fds[1]);
+out_close_data:
+	close(data_fds[0]);
+	close(data_fds[1]);
+	return err;
+}
+
+static void etap_close(int fd, void *data)
+{
+	struct ethertap_data *pri = data;
+
+	iter_addresses(pri->dev, etap_close_addr, &pri->control_fd);
+	close(fd);
+
+	if (shutdown(pri->data_fd, SHUT_RDWR) < 0)
+		printk(UM_KERN_ERR "etap_close - shutdown data socket failed, "
+		       "errno = %d\n", errno);
+
+	if (shutdown(pri->control_fd, SHUT_RDWR) < 0)
+		printk(UM_KERN_ERR "etap_close - shutdown control socket "
+		       "failed, errno = %d\n", errno);
+
+	close(pri->data_fd);
+	pri->data_fd = -1;
+	close(pri->control_fd);
+	pri->control_fd = -1;
+}
+
+static void etap_add_addr(unsigned char *addr, unsigned char *netmask,
+			  void *data)
+{
+	struct ethertap_data *pri = data;
+
+	tap_check_ips(pri->gate_addr, addr);
+	if (pri->control_fd == -1)
+		return;
+	etap_open_addr(addr, netmask, &pri->control_fd);
+}
+
+static void etap_del_addr(unsigned char *addr, unsigned char *netmask,
+			  void *data)
+{
+	struct ethertap_data *pri = data;
+
+	if (pri->control_fd == -1)
+		return;
+
+	etap_close_addr(addr, netmask, &pri->control_fd);
+}
+
+const struct net_user_info ethertap_user_info = {
+	.init		= etap_user_init,
+	.open		= etap_open,
+	.close	 	= etap_close,
+	.remove	 	= NULL,
+	.add_address	= etap_add_addr,
+	.delete_address = etap_del_addr,
+	.mtu		= ETH_MAX_PACKET,
+	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_ETHERTAP,
+};
diff --git a/arch/um/os-Linux/drivers/tuntap.h b/arch/um/os-Linux/drivers/tuntap.h
new file mode 100644
index 000000000..e364e42ab
--- /dev/null
+++ b/arch/um/os-Linux/drivers/tuntap.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* 
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#ifndef __UM_TUNTAP_H
+#define __UM_TUNTAP_H
+
+#include <net_user.h>
+
+struct tuntap_data {
+	char *dev_name;
+	int fixed_config;
+	char *gate_addr;
+	int fd;
+	void *dev;
+};
+
+extern const struct net_user_info tuntap_user_info;
+
+#endif
diff --git a/arch/um/os-Linux/drivers/tuntap_kern.c b/arch/um/os-Linux/drivers/tuntap_kern.c
new file mode 100644
index 000000000..adcb6717b
--- /dev/null
+++ b/arch/um/os-Linux/drivers/tuntap_kern.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <linux/netdevice.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <asm/errno.h>
+#include <net_kern.h>
+#include "tuntap.h"
+
+struct tuntap_init {
+	char *dev_name;
+	char *gate_addr;
+};
+
+static void tuntap_init(struct net_device *dev, void *data)
+{
+	struct uml_net_private *pri;
+	struct tuntap_data *tpri;
+	struct tuntap_init *init = data;
+
+	pri = netdev_priv(dev);
+	tpri = (struct tuntap_data *) pri->user;
+	tpri->dev_name = init->dev_name;
+	tpri->fixed_config = (init->dev_name != NULL);
+	tpri->gate_addr = init->gate_addr;
+	tpri->fd = -1;
+	tpri->dev = dev;
+
+	printk(KERN_INFO "TUN/TAP backend - ");
+	if (tpri->gate_addr != NULL)
+		printk(KERN_CONT "IP = %s", tpri->gate_addr);
+	printk(KERN_CONT "\n");
+}
+
+static int tuntap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+	return net_read(fd, skb_mac_header(skb),
+			skb->dev->mtu + ETH_HEADER_OTHER);
+}
+
+static int tuntap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
+{
+	return net_write(fd, skb->data, skb->len);
+}
+
+const struct net_kern_info tuntap_kern_info = {
+	.init			= tuntap_init,
+	.protocol		= eth_protocol,
+	.read			= tuntap_read,
+	.write 			= tuntap_write,
+};
+
+int tuntap_setup(char *str, char **mac_out, void *data)
+{
+	struct tuntap_init *init = data;
+
+	*init = ((struct tuntap_init)
+		{ .dev_name 	= NULL,
+		  .gate_addr 	= NULL });
+	if (tap_setup_common(str, "tuntap", &init->dev_name, mac_out,
+			    &init->gate_addr))
+		return 0;
+
+	return 1;
+}
+
+static struct transport tuntap_transport = {
+	.list 		= LIST_HEAD_INIT(tuntap_transport.list),
+	.name 		= "tuntap",
+	.setup  	= tuntap_setup,
+	.user 		= &tuntap_user_info,
+	.kern 		= &tuntap_kern_info,
+	.private_size 	= sizeof(struct tuntap_data),
+	.setup_size 	= sizeof(struct tuntap_init),
+};
+
+static int register_tuntap(void)
+{
+	register_transport(&tuntap_transport);
+	return 0;
+}
+
+late_initcall(register_tuntap);
diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
new file mode 100644
index 000000000..53eb3d508
--- /dev/null
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/* 
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <linux/if_tun.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/uio.h>
+#include <kern_util.h>
+#include <os.h>
+#include "tuntap.h"
+
+static int tuntap_user_init(void *data, void *dev)
+{
+	struct tuntap_data *pri = data;
+
+	pri->dev = dev;
+	return 0;
+}
+
+static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
+			    void *data)
+{
+	struct tuntap_data *pri = data;
+
+	tap_check_ips(pri->gate_addr, addr);
+	if ((pri->fd == -1) || pri->fixed_config)
+		return;
+	open_addr(addr, netmask, pri->dev_name);
+}
+
+static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
+			    void *data)
+{
+	struct tuntap_data *pri = data;
+
+	if ((pri->fd == -1) || pri->fixed_config)
+		return;
+	close_addr(addr, netmask, pri->dev_name);
+}
+
+struct tuntap_pre_exec_data {
+	int stdout_fd;
+	int close_me;
+};
+
+static void tuntap_pre_exec(void *arg)
+{
+	struct tuntap_pre_exec_data *data = arg;
+
+	dup2(data->stdout_fd, 1);
+	close(data->close_me);
+}
+
+static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
+			     char *buffer, int buffer_len, int *used_out)
+{
+	struct tuntap_pre_exec_data data;
+	char version_buf[sizeof("nnnnn\0")];
+	char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
+			 NULL };
+	char buf[CMSG_SPACE(sizeof(*fd_out))];
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	struct iovec iov;
+	int pid, n, err;
+
+	sprintf(version_buf, "%d", UML_NET_VERSION);
+
+	data.stdout_fd = remote;
+	data.close_me = me;
+
+	pid = run_helper(tuntap_pre_exec, &data, argv);
+
+	if (pid < 0)
+		return pid;
+
+	close(remote);
+
+	msg.msg_name = NULL;
+	msg.msg_namelen = 0;
+	if (buffer != NULL) {
+		iov = ((struct iovec) { buffer, buffer_len });
+		msg.msg_iov = &iov;
+		msg.msg_iovlen = 1;
+	}
+	else {
+		msg.msg_iov = NULL;
+		msg.msg_iovlen = 0;
+	}
+	msg.msg_control = buf;
+	msg.msg_controllen = sizeof(buf);
+	msg.msg_flags = 0;
+	n = recvmsg(me, &msg, 0);
+	*used_out = n;
+	if (n < 0) {
+		err = -errno;
+		printk(UM_KERN_ERR "tuntap_open_tramp : recvmsg failed - "
+		       "errno = %d\n", errno);
+		return err;
+	}
+	helper_wait(pid);
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	if (cmsg == NULL) {
+		printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
+		       "message\n");
+		return -EINVAL;
+	}
+	if ((cmsg->cmsg_level != SOL_SOCKET) ||
+	   (cmsg->cmsg_type != SCM_RIGHTS)) {
+		printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
+		       "descriptor\n");
+		return -EINVAL;
+	}
+	*fd_out = ((int *) CMSG_DATA(cmsg))[0];
+	os_set_exec_close(*fd_out);
+	return 0;
+}
+
+static int tuntap_open(void *data)
+{
+	struct ifreq ifr;
+	struct tuntap_data *pri = data;
+	char *output, *buffer;
+	int err, fds[2], len, used;
+
+	err = tap_open_common(pri->dev, pri->gate_addr);
+	if (err < 0)
+		return err;
+
+	if (pri->fixed_config) {
+		pri->fd = os_open_file("/dev/net/tun",
+				       of_cloexec(of_rdwr(OPENFLAGS())), 0);
+		if (pri->fd < 0) {
+			printk(UM_KERN_ERR "Failed to open /dev/net/tun, "
+			       "err = %d\n", -pri->fd);
+			return pri->fd;
+		}
+		memset(&ifr, 0, sizeof(ifr));
+		ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+		strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
+		if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) {
+			err = -errno;
+			printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",
+			       errno);
+			close(pri->fd);
+			return err;
+		}
+	}
+	else {
+		err = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds);
+		if (err) {
+			err = -errno;
+			printk(UM_KERN_ERR "tuntap_open : socketpair failed - "
+			       "errno = %d\n", errno);
+			return err;
+		}
+
+		buffer = get_output_buffer(&len);
+		if (buffer != NULL)
+			len--;
+		used = 0;
+
+		err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
+					fds[1], buffer, len, &used);
+
+		output = buffer;
+		if (err < 0) {
+			printk("%s", output);
+			free_output_buffer(buffer);
+			printk(UM_KERN_ERR "tuntap_open_tramp failed - "
+			       "err = %d\n", -err);
+			return err;
+		}
+
+		pri->dev_name = uml_strdup(buffer);
+		output += IFNAMSIZ;
+		printk("%s", output);
+		free_output_buffer(buffer);
+
+		close(fds[0]);
+		iter_addresses(pri->dev, open_addr, pri->dev_name);
+	}
+
+	return pri->fd;
+}
+
+static void tuntap_close(int fd, void *data)
+{
+	struct tuntap_data *pri = data;
+
+	if (!pri->fixed_config)
+		iter_addresses(pri->dev, close_addr, pri->dev_name);
+	close(fd);
+	pri->fd = -1;
+}
+
+const struct net_user_info tuntap_user_info = {
+	.init		= tuntap_user_init,
+	.open		= tuntap_open,
+	.close	 	= tuntap_close,
+	.remove	 	= NULL,
+	.add_address	= tuntap_add_addr,
+	.delete_address = tuntap_del_addr,
+	.mtu		= ETH_MAX_PACKET,
+	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_OTHER,
+};