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, 688 insertions, 0 deletions

diff --git a/drivers/usb/usbip/stub_rx.c b/drivers/usb/usbip/stub_rx.c
new file mode 100644
index 000000000..fc01b31bb
--- /dev/null
+++ b/drivers/usb/usbip/stub_rx.c
@@ -0,0 +1,688 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2003-2008 Takahiro Hirofuchi
+ */
+
+#include <asm/byteorder.h>
+#include <linux/kthread.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+#include <linux/scatterlist.h>
+
+#include "usbip_common.h"
+#include "stub.h"
+
+static int is_clear_halt_cmd(struct urb *urb)
+{
+	struct usb_ctrlrequest *req;
+
+	req = (struct usb_ctrlrequest *) urb->setup_packet;
+
+	return (req->bRequest == USB_REQ_CLEAR_FEATURE) &&
+	       (req->bRequestType == USB_RECIP_ENDPOINT) &&
+	       (req->wValue == USB_ENDPOINT_HALT);
+}
+
+static int is_set_interface_cmd(struct urb *urb)
+{
+	struct usb_ctrlrequest *req;
+
+	req = (struct usb_ctrlrequest *) urb->setup_packet;
+
+	return (req->bRequest == USB_REQ_SET_INTERFACE) &&
+		(req->bRequestType == USB_RECIP_INTERFACE);
+}
+
+static int is_set_configuration_cmd(struct urb *urb)
+{
+	struct usb_ctrlrequest *req;
+
+	req = (struct usb_ctrlrequest *) urb->setup_packet;
+
+	return (req->bRequest == USB_REQ_SET_CONFIGURATION) &&
+		(req->bRequestType == USB_RECIP_DEVICE);
+}
+
+static int is_reset_device_cmd(struct urb *urb)
+{
+	struct usb_ctrlrequest *req;
+	__u16 value;
+	__u16 index;
+
+	req = (struct usb_ctrlrequest *) urb->setup_packet;
+	value = le16_to_cpu(req->wValue);
+	index = le16_to_cpu(req->wIndex);
+
+	if ((req->bRequest == USB_REQ_SET_FEATURE) &&
+	    (req->bRequestType == USB_RT_PORT) &&
+	    (value == USB_PORT_FEAT_RESET)) {
+		usbip_dbg_stub_rx("reset_device_cmd, port %u\n", index);
+		return 1;
+	} else
+		return 0;
+}
+
+static int tweak_clear_halt_cmd(struct urb *urb)
+{
+	struct usb_ctrlrequest *req;
+	int target_endp;
+	int target_dir;
+	int target_pipe;
+	int ret;
+
+	req = (struct usb_ctrlrequest *) urb->setup_packet;
+
+	/*
+	 * The stalled endpoint is specified in the wIndex value. The endpoint
+	 * of the urb is the target of this clear_halt request (i.e., control
+	 * endpoint).
+	 */
+	target_endp = le16_to_cpu(req->wIndex) & 0x000f;
+
+	/* the stalled endpoint direction is IN or OUT?. USB_DIR_IN is 0x80.  */
+	target_dir = le16_to_cpu(req->wIndex) & 0x0080;
+
+	if (target_dir)
+		target_pipe = usb_rcvctrlpipe(urb->dev, target_endp);
+	else
+		target_pipe = usb_sndctrlpipe(urb->dev, target_endp);
+
+	ret = usb_clear_halt(urb->dev, target_pipe);
+	if (ret < 0)
+		dev_err(&urb->dev->dev,
+			"usb_clear_halt error: devnum %d endp %d ret %d\n",
+			urb->dev->devnum, target_endp, ret);
+	else
+		dev_info(&urb->dev->dev,
+			 "usb_clear_halt done: devnum %d endp %d\n",
+			 urb->dev->devnum, target_endp);
+
+	return ret;
+}
+
+static int tweak_set_interface_cmd(struct urb *urb)
+{
+	struct usb_ctrlrequest *req;
+	__u16 alternate;
+	__u16 interface;
+	int ret;
+
+	req = (struct usb_ctrlrequest *) urb->setup_packet;
+	alternate = le16_to_cpu(req->wValue);
+	interface = le16_to_cpu(req->wIndex);
+
+	usbip_dbg_stub_rx("set_interface: inf %u alt %u\n",
+			  interface, alternate);
+
+	ret = usb_set_interface(urb->dev, interface, alternate);
+	if (ret < 0)
+		dev_err(&urb->dev->dev,
+			"usb_set_interface error: inf %u alt %u ret %d\n",
+			interface, alternate, ret);
+	else
+		dev_info(&urb->dev->dev,
+			"usb_set_interface done: inf %u alt %u\n",
+			interface, alternate);
+
+	return ret;
+}
+
+static int tweak_set_configuration_cmd(struct urb *urb)
+{
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+	struct stub_device *sdev = priv->sdev;
+	struct usb_ctrlrequest *req;
+	__u16 config;
+	int err;
+
+	req = (struct usb_ctrlrequest *) urb->setup_packet;
+	config = le16_to_cpu(req->wValue);
+
+	usb_lock_device(sdev->udev);
+	err = usb_set_configuration(sdev->udev, config);
+	usb_unlock_device(sdev->udev);
+	if (err && err != -ENODEV)
+		dev_err(&sdev->udev->dev, "can't set config #%d, error %d\n",
+			config, err);
+	return 0;
+}
+
+static int tweak_reset_device_cmd(struct urb *urb)
+{
+	struct stub_priv *priv = (struct stub_priv *) urb->context;
+	struct stub_device *sdev = priv->sdev;
+
+	dev_info(&urb->dev->dev, "usb_queue_reset_device\n");
+
+	if (usb_lock_device_for_reset(sdev->udev, NULL) < 0) {
+		dev_err(&urb->dev->dev, "could not obtain lock to reset device\n");
+		return 0;
+	}
+	usb_reset_device(sdev->udev);
+	usb_unlock_device(sdev->udev);
+
+	return 0;
+}
+
+/*
+ * clear_halt, set_interface, and set_configuration require special tricks.
+ */
+static void tweak_special_requests(struct urb *urb)
+{
+	if (!urb || !urb->setup_packet)
+		return;
+
+	if (usb_pipetype(urb->pipe) != PIPE_CONTROL)
+		return;
+
+	if (is_clear_halt_cmd(urb))
+		/* tweak clear_halt */
+		 tweak_clear_halt_cmd(urb);
+
+	else if (is_set_interface_cmd(urb))
+		/* tweak set_interface */
+		tweak_set_interface_cmd(urb);
+
+	else if (is_set_configuration_cmd(urb))
+		/* tweak set_configuration */
+		tweak_set_configuration_cmd(urb);
+
+	else if (is_reset_device_cmd(urb))
+		tweak_reset_device_cmd(urb);
+	else
+		usbip_dbg_stub_rx("no need to tweak\n");
+}
+
+/*
+ * stub_recv_unlink() unlinks the URB by a call to usb_unlink_urb().
+ * By unlinking the urb asynchronously, stub_rx can continuously
+ * process coming urbs.  Even if the urb is unlinked, its completion
+ * handler will be called and stub_tx will send a return pdu.
+ *
+ * See also comments about unlinking strategy in vhci_hcd.c.
+ */
+static int stub_recv_cmd_unlink(struct stub_device *sdev,
+				struct usbip_header *pdu)
+{
+	int ret, i;
+	unsigned long flags;
+	struct stub_priv *priv;
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	list_for_each_entry(priv, &sdev->priv_init, list) {
+		if (priv->seqnum != pdu->u.cmd_unlink.seqnum)
+			continue;
+
+		/*
+		 * This matched urb is not completed yet (i.e., be in
+		 * flight in usb hcd hardware/driver). Now we are
+		 * cancelling it. The unlinking flag means that we are
+		 * now not going to return the normal result pdu of a
+		 * submission request, but going to return a result pdu
+		 * of the unlink request.
+		 */
+		priv->unlinking = 1;
+
+		/*
+		 * In the case that unlinking flag is on, prev->seqnum
+		 * is changed from the seqnum of the cancelling urb to
+		 * the seqnum of the unlink request. This will be used
+		 * to make the result pdu of the unlink request.
+		 */
+		priv->seqnum = pdu->base.seqnum;
+
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+		/*
+		 * usb_unlink_urb() is now out of spinlocking to avoid
+		 * spinlock recursion since stub_complete() is
+		 * sometimes called in this context but not in the
+		 * interrupt context.  If stub_complete() is executed
+		 * before we call usb_unlink_urb(), usb_unlink_urb()
+		 * will return an error value. In this case, stub_tx
+		 * will return the result pdu of this unlink request
+		 * though submission is completed and actual unlinking
+		 * is not executed. OK?
+		 */
+		/* In the above case, urb->status is not -ECONNRESET,
+		 * so a driver in a client host will know the failure
+		 * of the unlink request ?
+		 */
+		for (i = priv->completed_urbs; i < priv->num_urbs; i++) {
+			ret = usb_unlink_urb(priv->urbs[i]);
+			if (ret != -EINPROGRESS)
+				dev_err(&priv->urbs[i]->dev->dev,
+					"failed to unlink %d/%d urb of seqnum %lu, ret %d\n",
+					i + 1, priv->num_urbs,
+					priv->seqnum, ret);
+		}
+		return 0;
+	}
+
+	usbip_dbg_stub_rx("seqnum %d is not pending\n",
+			  pdu->u.cmd_unlink.seqnum);
+
+	/*
+	 * The urb of the unlink target is not found in priv_init queue. It was
+	 * already completed and its results is/was going to be sent by a
+	 * CMD_RET pdu. In this case, usb_unlink_urb() is not needed. We only
+	 * return the completeness of this unlink request to vhci_hcd.
+	 */
+	stub_enqueue_ret_unlink(sdev, pdu->base.seqnum, 0);
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return 0;
+}
+
+static int valid_request(struct stub_device *sdev, struct usbip_header *pdu)
+{
+	struct usbip_device *ud = &sdev->ud;
+	int valid = 0;
+
+	if (pdu->base.devid == sdev->devid) {
+		spin_lock_irq(&ud->lock);
+		if (ud->status == SDEV_ST_USED) {
+			/* A request is valid. */
+			valid = 1;
+		}
+		spin_unlock_irq(&ud->lock);
+	}
+
+	return valid;
+}
+
+static struct stub_priv *stub_priv_alloc(struct stub_device *sdev,
+					 struct usbip_header *pdu)
+{
+	struct stub_priv *priv;
+	struct usbip_device *ud = &sdev->ud;
+	unsigned long flags;
+
+	spin_lock_irqsave(&sdev->priv_lock, flags);
+
+	priv = kmem_cache_zalloc(stub_priv_cache, GFP_ATOMIC);
+	if (!priv) {
+		dev_err(&sdev->udev->dev, "alloc stub_priv\n");
+		spin_unlock_irqrestore(&sdev->priv_lock, flags);
+		usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
+		return NULL;
+	}
+
+	priv->seqnum = pdu->base.seqnum;
+	priv->sdev = sdev;
+
+	/*
+	 * After a stub_priv is linked to a list_head,
+	 * our error handler can free allocated data.
+	 */
+	list_add_tail(&priv->list, &sdev->priv_init);
+
+	spin_unlock_irqrestore(&sdev->priv_lock, flags);
+
+	return priv;
+}
+
+static int get_pipe(struct stub_device *sdev, struct usbip_header *pdu)
+{
+	struct usb_device *udev = sdev->udev;
+	struct usb_host_endpoint *ep;
+	struct usb_endpoint_descriptor *epd = NULL;
+	int epnum = pdu->base.ep;
+	int dir = pdu->base.direction;
+
+	if (epnum < 0 || epnum > 15)
+		goto err_ret;
+
+	if (dir == USBIP_DIR_IN)
+		ep = udev->ep_in[epnum & 0x7f];
+	else
+		ep = udev->ep_out[epnum & 0x7f];
+	if (!ep)
+		goto err_ret;
+
+	epd = &ep->desc;
+
+	if (usb_endpoint_xfer_control(epd)) {
+		if (dir == USBIP_DIR_OUT)
+			return usb_sndctrlpipe(udev, epnum);
+		else
+			return usb_rcvctrlpipe(udev, epnum);
+	}
+
+	if (usb_endpoint_xfer_bulk(epd)) {
+		if (dir == USBIP_DIR_OUT)
+			return usb_sndbulkpipe(udev, epnum);
+		else
+			return usb_rcvbulkpipe(udev, epnum);
+	}
+
+	if (usb_endpoint_xfer_int(epd)) {
+		if (dir == USBIP_DIR_OUT)
+			return usb_sndintpipe(udev, epnum);
+		else
+			return usb_rcvintpipe(udev, epnum);
+	}
+
+	if (usb_endpoint_xfer_isoc(epd)) {
+		/* validate number of packets */
+		if (pdu->u.cmd_submit.number_of_packets < 0 ||
+		    pdu->u.cmd_submit.number_of_packets >
+		    USBIP_MAX_ISO_PACKETS) {
+			dev_err(&sdev->udev->dev,
+				"CMD_SUBMIT: isoc invalid num packets %d\n",
+				pdu->u.cmd_submit.number_of_packets);
+			return -1;
+		}
+		if (dir == USBIP_DIR_OUT)
+			return usb_sndisocpipe(udev, epnum);
+		else
+			return usb_rcvisocpipe(udev, epnum);
+	}
+
+err_ret:
+	/* NOT REACHED */
+	dev_err(&sdev->udev->dev, "CMD_SUBMIT: invalid epnum %d\n", epnum);
+	return -1;
+}
+
+static void masking_bogus_flags(struct urb *urb)
+{
+	int				xfertype;
+	struct usb_device		*dev;
+	struct usb_host_endpoint	*ep;
+	int				is_out;
+	unsigned int	allowed;
+
+	if (!urb || urb->hcpriv || !urb->complete)
+		return;
+	dev = urb->dev;
+	if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
+		return;
+
+	ep = (usb_pipein(urb->pipe) ? dev->ep_in : dev->ep_out)
+		[usb_pipeendpoint(urb->pipe)];
+	if (!ep)
+		return;
+
+	xfertype = usb_endpoint_type(&ep->desc);
+	if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
+		struct usb_ctrlrequest *setup =
+			(struct usb_ctrlrequest *) urb->setup_packet;
+
+		if (!setup)
+			return;
+		is_out = !(setup->bRequestType & USB_DIR_IN) ||
+			!setup->wLength;
+	} else {
+		is_out = usb_endpoint_dir_out(&ep->desc);
+	}
+
+	/* enforce simple/standard policy */
+	allowed = (URB_NO_TRANSFER_DMA_MAP | URB_NO_INTERRUPT |
+		   URB_DIR_MASK | URB_FREE_BUFFER);
+	switch (xfertype) {
+	case USB_ENDPOINT_XFER_BULK:
+		if (is_out)
+			allowed |= URB_ZERO_PACKET;
+		fallthrough;
+	default:			/* all non-iso endpoints */
+		if (!is_out)
+			allowed |= URB_SHORT_NOT_OK;
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		allowed |= URB_ISO_ASAP;
+		break;
+	}
+	urb->transfer_flags &= allowed;
+}
+
+static int stub_recv_xbuff(struct usbip_device *ud, struct stub_priv *priv)
+{
+	int ret;
+	int i;
+
+	for (i = 0; i < priv->num_urbs; i++) {
+		ret = usbip_recv_xbuff(ud, priv->urbs[i]);
+		if (ret < 0)
+			break;
+	}
+
+	return ret;
+}
+
+static void stub_recv_cmd_submit(struct stub_device *sdev,
+				 struct usbip_header *pdu)
+{
+	struct stub_priv *priv;
+	struct usbip_device *ud = &sdev->ud;
+	struct usb_device *udev = sdev->udev;
+	struct scatterlist *sgl = NULL, *sg;
+	void *buffer = NULL;
+	unsigned long long buf_len;
+	int nents;
+	int num_urbs = 1;
+	int pipe = get_pipe(sdev, pdu);
+	int use_sg = pdu->u.cmd_submit.transfer_flags & USBIP_URB_DMA_MAP_SG;
+	int support_sg = 1;
+	int np = 0;
+	int ret, i;
+
+	if (pipe == -1)
+		return;
+
+	/*
+	 * Smatch reported the error case where use_sg is true and buf_len is 0.
+	 * In this case, It adds SDEV_EVENT_ERROR_MALLOC and stub_priv will be
+	 * released by stub event handler and connection will be shut down.
+	 */
+	priv = stub_priv_alloc(sdev, pdu);
+	if (!priv)
+		return;
+
+	buf_len = (unsigned long long)pdu->u.cmd_submit.transfer_buffer_length;
+
+	if (use_sg && !buf_len) {
+		dev_err(&udev->dev, "sg buffer with zero length\n");
+		goto err_malloc;
+	}
+
+	/* allocate urb transfer buffer, if needed */
+	if (buf_len) {
+		if (use_sg) {
+			sgl = sgl_alloc(buf_len, GFP_KERNEL, &nents);
+			if (!sgl)
+				goto err_malloc;
+
+			/* Check if the server's HCD supports SG */
+			if (!udev->bus->sg_tablesize) {
+				/*
+				 * If the server's HCD doesn't support SG, break
+				 * a single SG request into several URBs and map
+				 * each SG list entry to corresponding URB
+				 * buffer. The previously allocated SG list is
+				 * stored in priv->sgl (If the server's HCD
+				 * support SG, SG list is stored only in
+				 * urb->sg) and it is used as an indicator that
+				 * the server split single SG request into
+				 * several URBs. Later, priv->sgl is used by
+				 * stub_complete() and stub_send_ret_submit() to
+				 * reassemble the divied URBs.
+				 */
+				support_sg = 0;
+				num_urbs = nents;
+				priv->completed_urbs = 0;
+				pdu->u.cmd_submit.transfer_flags &=
+								~USBIP_URB_DMA_MAP_SG;
+			}
+		} else {
+			buffer = kzalloc(buf_len, GFP_KERNEL);
+			if (!buffer)
+				goto err_malloc;
+		}
+	}
+
+	/* allocate urb array */
+	priv->num_urbs = num_urbs;
+	priv->urbs = kmalloc_array(num_urbs, sizeof(*priv->urbs), GFP_KERNEL);
+	if (!priv->urbs)
+		goto err_urbs;
+
+	/* setup a urb */
+	if (support_sg) {
+		if (usb_pipeisoc(pipe))
+			np = pdu->u.cmd_submit.number_of_packets;
+
+		priv->urbs[0] = usb_alloc_urb(np, GFP_KERNEL);
+		if (!priv->urbs[0])
+			goto err_urb;
+
+		if (buf_len) {
+			if (use_sg) {
+				priv->urbs[0]->sg = sgl;
+				priv->urbs[0]->num_sgs = nents;
+				priv->urbs[0]->transfer_buffer = NULL;
+			} else {
+				priv->urbs[0]->transfer_buffer = buffer;
+			}
+		}
+
+		/* copy urb setup packet */
+		priv->urbs[0]->setup_packet = kmemdup(&pdu->u.cmd_submit.setup,
+					8, GFP_KERNEL);
+		if (!priv->urbs[0]->setup_packet) {
+			usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
+			return;
+		}
+
+		usbip_pack_pdu(pdu, priv->urbs[0], USBIP_CMD_SUBMIT, 0);
+	} else {
+		for_each_sg(sgl, sg, nents, i) {
+			priv->urbs[i] = usb_alloc_urb(0, GFP_KERNEL);
+			/* The URBs which is previously allocated will be freed
+			 * in stub_device_cleanup_urbs() if error occurs.
+			 */
+			if (!priv->urbs[i])
+				goto err_urb;
+
+			usbip_pack_pdu(pdu, priv->urbs[i], USBIP_CMD_SUBMIT, 0);
+			priv->urbs[i]->transfer_buffer = sg_virt(sg);
+			priv->urbs[i]->transfer_buffer_length = sg->length;
+		}
+		priv->sgl = sgl;
+	}
+
+	for (i = 0; i < num_urbs; i++) {
+		/* set other members from the base header of pdu */
+		priv->urbs[i]->context = (void *) priv;
+		priv->urbs[i]->dev = udev;
+		priv->urbs[i]->pipe = pipe;
+		priv->urbs[i]->complete = stub_complete;
+
+		/* no need to submit an intercepted request, but harmless? */
+		tweak_special_requests(priv->urbs[i]);
+
+		masking_bogus_flags(priv->urbs[i]);
+	}
+
+	if (stub_recv_xbuff(ud, priv) < 0)
+		return;
+
+	if (usbip_recv_iso(ud, priv->urbs[0]) < 0)
+		return;
+
+	/* urb is now ready to submit */
+	for (i = 0; i < priv->num_urbs; i++) {
+		ret = usb_submit_urb(priv->urbs[i], GFP_KERNEL);
+
+		if (ret == 0)
+			usbip_dbg_stub_rx("submit urb ok, seqnum %u\n",
+					pdu->base.seqnum);
+		else {
+			dev_err(&udev->dev, "submit_urb error, %d\n", ret);
+			usbip_dump_header(pdu);
+			usbip_dump_urb(priv->urbs[i]);
+
+			/*
+			 * Pessimistic.
+			 * This connection will be discarded.
+			 */
+			usbip_event_add(ud, SDEV_EVENT_ERROR_SUBMIT);
+			break;
+		}
+	}
+
+	usbip_dbg_stub_rx("Leave\n");
+	return;
+
+err_urb:
+	kfree(priv->urbs);
+err_urbs:
+	kfree(buffer);
+	sgl_free(sgl);
+err_malloc:
+	usbip_event_add(ud, SDEV_EVENT_ERROR_MALLOC);
+}
+
+/* recv a pdu */
+static void stub_rx_pdu(struct usbip_device *ud)
+{
+	int ret;
+	struct usbip_header pdu;
+	struct stub_device *sdev = container_of(ud, struct stub_device, ud);
+	struct device *dev = &sdev->udev->dev;
+
+	usbip_dbg_stub_rx("Enter\n");
+
+	memset(&pdu, 0, sizeof(pdu));
+
+	/* receive a pdu header */
+	ret = usbip_recv(ud->tcp_socket, &pdu, sizeof(pdu));
+	if (ret != sizeof(pdu)) {
+		dev_err(dev, "recv a header, %d\n", ret);
+		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+		return;
+	}
+
+	usbip_header_correct_endian(&pdu, 0);
+
+	if (usbip_dbg_flag_stub_rx)
+		usbip_dump_header(&pdu);
+
+	if (!valid_request(sdev, &pdu)) {
+		dev_err(dev, "recv invalid request\n");
+		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+		return;
+	}
+
+	switch (pdu.base.command) {
+	case USBIP_CMD_UNLINK:
+		stub_recv_cmd_unlink(sdev, &pdu);
+		break;
+
+	case USBIP_CMD_SUBMIT:
+		stub_recv_cmd_submit(sdev, &pdu);
+		break;
+
+	default:
+		/* NOTREACHED */
+		dev_err(dev, "unknown pdu\n");
+		usbip_event_add(ud, SDEV_EVENT_ERROR_TCP);
+		break;
+	}
+}
+
+int stub_rx_loop(void *data)
+{
+	struct usbip_device *ud = data;
+
+	while (!kthread_should_stop()) {
+		if (usbip_event_happened(ud))
+			break;
+
+		stub_rx_pdu(ud);
+	}
+
+	return 0;
+}