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, 649 insertions, 0 deletions

diff --git a/net/802/garp.c b/net/802/garp.c
new file mode 100644
index 000000000..ab24b21fb
--- /dev/null
+++ b/net/802/garp.c
@@ -0,0 +1,649 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *	IEEE 802.1D Generic Attribute Registration Protocol (GARP)
+ *
+ *	Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ */
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/llc.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <net/llc.h>
+#include <net/llc_pdu.h>
+#include <net/garp.h>
+#include <asm/unaligned.h>
+
+static unsigned int garp_join_time __read_mostly = 200;
+module_param(garp_join_time, uint, 0644);
+MODULE_PARM_DESC(garp_join_time, "Join time in ms (default 200ms)");
+MODULE_LICENSE("GPL");
+
+static const struct garp_state_trans {
+	u8	state;
+	u8	action;
+} garp_applicant_state_table[GARP_APPLICANT_MAX + 1][GARP_EVENT_MAX + 1] = {
+	[GARP_APPLICANT_VA] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_AA,
+						    .action = GARP_ACTION_S_JOIN_IN },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_AA },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_LA },
+	},
+	[GARP_APPLICANT_AA] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_QA,
+						    .action = GARP_ACTION_S_JOIN_IN },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QA },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_LA },
+	},
+	[GARP_APPLICANT_QA] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QA },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_LA },
+	},
+	[GARP_APPLICANT_LA] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_VO,
+						    .action = GARP_ACTION_S_LEAVE_EMPTY },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_LA },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_LA },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_LA },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_VA },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_INVALID },
+	},
+	[GARP_APPLICANT_VP] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_AA,
+						    .action = GARP_ACTION_S_JOIN_IN },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_AP },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_VO },
+	},
+	[GARP_APPLICANT_AP] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_QA,
+						    .action = GARP_ACTION_S_JOIN_IN },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QP },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_AO },
+	},
+	[GARP_APPLICANT_QP] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QP },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_QO },
+	},
+	[GARP_APPLICANT_VO] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_AO },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_VP },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_INVALID },
+	},
+	[GARP_APPLICANT_AO] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QO },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_AP },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_INVALID },
+	},
+	[GARP_APPLICANT_QO] = {
+		[GARP_EVENT_TRANSMIT_PDU]	= { .state = GARP_APPLICANT_INVALID },
+		[GARP_EVENT_R_JOIN_IN]		= { .state = GARP_APPLICANT_QO },
+		[GARP_EVENT_R_JOIN_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_EMPTY]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_IN]		= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_R_LEAVE_EMPTY]	= { .state = GARP_APPLICANT_VO },
+		[GARP_EVENT_REQ_JOIN]		= { .state = GARP_APPLICANT_QP },
+		[GARP_EVENT_REQ_LEAVE]		= { .state = GARP_APPLICANT_INVALID },
+	},
+};
+
+static int garp_attr_cmp(const struct garp_attr *attr,
+			 const void *data, u8 len, u8 type)
+{
+	if (attr->type != type)
+		return attr->type - type;
+	if (attr->dlen != len)
+		return attr->dlen - len;
+	return memcmp(attr->data, data, len);
+}
+
+static struct garp_attr *garp_attr_lookup(const struct garp_applicant *app,
+					  const void *data, u8 len, u8 type)
+{
+	struct rb_node *parent = app->gid.rb_node;
+	struct garp_attr *attr;
+	int d;
+
+	while (parent) {
+		attr = rb_entry(parent, struct garp_attr, node);
+		d = garp_attr_cmp(attr, data, len, type);
+		if (d > 0)
+			parent = parent->rb_left;
+		else if (d < 0)
+			parent = parent->rb_right;
+		else
+			return attr;
+	}
+	return NULL;
+}
+
+static struct garp_attr *garp_attr_create(struct garp_applicant *app,
+					  const void *data, u8 len, u8 type)
+{
+	struct rb_node *parent = NULL, **p = &app->gid.rb_node;
+	struct garp_attr *attr;
+	int d;
+
+	while (*p) {
+		parent = *p;
+		attr = rb_entry(parent, struct garp_attr, node);
+		d = garp_attr_cmp(attr, data, len, type);
+		if (d > 0)
+			p = &parent->rb_left;
+		else if (d < 0)
+			p = &parent->rb_right;
+		else {
+			/* The attribute already exists; re-use it. */
+			return attr;
+		}
+	}
+	attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+	if (!attr)
+		return attr;
+	attr->state = GARP_APPLICANT_VO;
+	attr->type  = type;
+	attr->dlen  = len;
+	memcpy(attr->data, data, len);
+
+	rb_link_node(&attr->node, parent, p);
+	rb_insert_color(&attr->node, &app->gid);
+	return attr;
+}
+
+static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr)
+{
+	rb_erase(&attr->node, &app->gid);
+	kfree(attr);
+}
+
+static void garp_attr_destroy_all(struct garp_applicant *app)
+{
+	struct rb_node *node, *next;
+	struct garp_attr *attr;
+
+	for (node = rb_first(&app->gid);
+	     next = node ? rb_next(node) : NULL, node != NULL;
+	     node = next) {
+		attr = rb_entry(node, struct garp_attr, node);
+		garp_attr_destroy(app, attr);
+	}
+}
+
+static int garp_pdu_init(struct garp_applicant *app)
+{
+	struct sk_buff *skb;
+	struct garp_pdu_hdr *gp;
+
+#define LLC_RESERVE	sizeof(struct llc_pdu_un)
+	skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
+			GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	skb->dev = app->dev;
+	skb->protocol = htons(ETH_P_802_2);
+	skb_reserve(skb, LL_RESERVED_SPACE(app->dev) + LLC_RESERVE);
+
+	gp = __skb_put(skb, sizeof(*gp));
+	put_unaligned(htons(GARP_PROTOCOL_ID), &gp->protocol);
+
+	app->pdu = skb;
+	return 0;
+}
+
+static int garp_pdu_append_end_mark(struct garp_applicant *app)
+{
+	if (skb_tailroom(app->pdu) < sizeof(u8))
+		return -1;
+	__skb_put_u8(app->pdu, GARP_END_MARK);
+	return 0;
+}
+
+static void garp_pdu_queue(struct garp_applicant *app)
+{
+	if (!app->pdu)
+		return;
+
+	garp_pdu_append_end_mark(app);
+	garp_pdu_append_end_mark(app);
+
+	llc_pdu_header_init(app->pdu, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
+			    LLC_SAP_BSPAN, LLC_PDU_CMD);
+	llc_pdu_init_as_ui_cmd(app->pdu);
+	llc_mac_hdr_init(app->pdu, app->dev->dev_addr,
+			 app->app->proto.group_address);
+
+	skb_queue_tail(&app->queue, app->pdu);
+	app->pdu = NULL;
+}
+
+static void garp_queue_xmit(struct garp_applicant *app)
+{
+	struct sk_buff *skb;
+
+	while ((skb = skb_dequeue(&app->queue)))
+		dev_queue_xmit(skb);
+}
+
+static int garp_pdu_append_msg(struct garp_applicant *app, u8 attrtype)
+{
+	struct garp_msg_hdr *gm;
+
+	if (skb_tailroom(app->pdu) < sizeof(*gm))
+		return -1;
+	gm = __skb_put(app->pdu, sizeof(*gm));
+	gm->attrtype = attrtype;
+	garp_cb(app->pdu)->cur_type = attrtype;
+	return 0;
+}
+
+static int garp_pdu_append_attr(struct garp_applicant *app,
+				const struct garp_attr *attr,
+				enum garp_attr_event event)
+{
+	struct garp_attr_hdr *ga;
+	unsigned int len;
+	int err;
+again:
+	if (!app->pdu) {
+		err = garp_pdu_init(app);
+		if (err < 0)
+			return err;
+	}
+
+	if (garp_cb(app->pdu)->cur_type != attr->type) {
+		if (garp_cb(app->pdu)->cur_type &&
+		    garp_pdu_append_end_mark(app) < 0)
+			goto queue;
+		if (garp_pdu_append_msg(app, attr->type) < 0)
+			goto queue;
+	}
+
+	len = sizeof(*ga) + attr->dlen;
+	if (skb_tailroom(app->pdu) < len)
+		goto queue;
+	ga = __skb_put(app->pdu, len);
+	ga->len   = len;
+	ga->event = event;
+	memcpy(ga->data, attr->data, attr->dlen);
+	return 0;
+
+queue:
+	garp_pdu_queue(app);
+	goto again;
+}
+
+static void garp_attr_event(struct garp_applicant *app,
+			    struct garp_attr *attr, enum garp_event event)
+{
+	enum garp_applicant_state state;
+
+	state = garp_applicant_state_table[attr->state][event].state;
+	if (state == GARP_APPLICANT_INVALID)
+		return;
+
+	switch (garp_applicant_state_table[attr->state][event].action) {
+	case GARP_ACTION_NONE:
+		break;
+	case GARP_ACTION_S_JOIN_IN:
+		/* When appending the attribute fails, don't update state in
+		 * order to retry on next TRANSMIT_PDU event. */
+		if (garp_pdu_append_attr(app, attr, GARP_JOIN_IN) < 0)
+			return;
+		break;
+	case GARP_ACTION_S_LEAVE_EMPTY:
+		garp_pdu_append_attr(app, attr, GARP_LEAVE_EMPTY);
+		/* As a pure applicant, sending a leave message implies that
+		 * the attribute was unregistered and can be destroyed. */
+		garp_attr_destroy(app, attr);
+		return;
+	default:
+		WARN_ON(1);
+	}
+
+	attr->state = state;
+}
+
+int garp_request_join(const struct net_device *dev,
+		      const struct garp_application *appl,
+		      const void *data, u8 len, u8 type)
+{
+	struct garp_port *port = rtnl_dereference(dev->garp_port);
+	struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
+	struct garp_attr *attr;
+
+	spin_lock_bh(&app->lock);
+	attr = garp_attr_create(app, data, len, type);
+	if (!attr) {
+		spin_unlock_bh(&app->lock);
+		return -ENOMEM;
+	}
+	garp_attr_event(app, attr, GARP_EVENT_REQ_JOIN);
+	spin_unlock_bh(&app->lock);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(garp_request_join);
+
+void garp_request_leave(const struct net_device *dev,
+			const struct garp_application *appl,
+			const void *data, u8 len, u8 type)
+{
+	struct garp_port *port = rtnl_dereference(dev->garp_port);
+	struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
+	struct garp_attr *attr;
+
+	spin_lock_bh(&app->lock);
+	attr = garp_attr_lookup(app, data, len, type);
+	if (!attr) {
+		spin_unlock_bh(&app->lock);
+		return;
+	}
+	garp_attr_event(app, attr, GARP_EVENT_REQ_LEAVE);
+	spin_unlock_bh(&app->lock);
+}
+EXPORT_SYMBOL_GPL(garp_request_leave);
+
+static void garp_gid_event(struct garp_applicant *app, enum garp_event event)
+{
+	struct rb_node *node, *next;
+	struct garp_attr *attr;
+
+	for (node = rb_first(&app->gid);
+	     next = node ? rb_next(node) : NULL, node != NULL;
+	     node = next) {
+		attr = rb_entry(node, struct garp_attr, node);
+		garp_attr_event(app, attr, event);
+	}
+}
+
+static void garp_join_timer_arm(struct garp_applicant *app)
+{
+	unsigned long delay;
+
+	delay = get_random_u32_below(msecs_to_jiffies(garp_join_time));
+	mod_timer(&app->join_timer, jiffies + delay);
+}
+
+static void garp_join_timer(struct timer_list *t)
+{
+	struct garp_applicant *app = from_timer(app, t, join_timer);
+
+	spin_lock(&app->lock);
+	garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
+	garp_pdu_queue(app);
+	spin_unlock(&app->lock);
+
+	garp_queue_xmit(app);
+	garp_join_timer_arm(app);
+}
+
+static int garp_pdu_parse_end_mark(struct sk_buff *skb)
+{
+	if (!pskb_may_pull(skb, sizeof(u8)))
+		return -1;
+	if (*skb->data == GARP_END_MARK) {
+		skb_pull(skb, sizeof(u8));
+		return -1;
+	}
+	return 0;
+}
+
+static int garp_pdu_parse_attr(struct garp_applicant *app, struct sk_buff *skb,
+			       u8 attrtype)
+{
+	const struct garp_attr_hdr *ga;
+	struct garp_attr *attr;
+	enum garp_event event;
+	unsigned int dlen;
+
+	if (!pskb_may_pull(skb, sizeof(*ga)))
+		return -1;
+	ga = (struct garp_attr_hdr *)skb->data;
+	if (ga->len < sizeof(*ga))
+		return -1;
+
+	if (!pskb_may_pull(skb, ga->len))
+		return -1;
+	skb_pull(skb, ga->len);
+	dlen = sizeof(*ga) - ga->len;
+
+	if (attrtype > app->app->maxattr)
+		return 0;
+
+	switch (ga->event) {
+	case GARP_LEAVE_ALL:
+		if (dlen != 0)
+			return -1;
+		garp_gid_event(app, GARP_EVENT_R_LEAVE_EMPTY);
+		return 0;
+	case GARP_JOIN_EMPTY:
+		event = GARP_EVENT_R_JOIN_EMPTY;
+		break;
+	case GARP_JOIN_IN:
+		event = GARP_EVENT_R_JOIN_IN;
+		break;
+	case GARP_LEAVE_EMPTY:
+		event = GARP_EVENT_R_LEAVE_EMPTY;
+		break;
+	case GARP_EMPTY:
+		event = GARP_EVENT_R_EMPTY;
+		break;
+	default:
+		return 0;
+	}
+
+	if (dlen == 0)
+		return -1;
+	attr = garp_attr_lookup(app, ga->data, dlen, attrtype);
+	if (attr == NULL)
+		return 0;
+	garp_attr_event(app, attr, event);
+	return 0;
+}
+
+static int garp_pdu_parse_msg(struct garp_applicant *app, struct sk_buff *skb)
+{
+	const struct garp_msg_hdr *gm;
+
+	if (!pskb_may_pull(skb, sizeof(*gm)))
+		return -1;
+	gm = (struct garp_msg_hdr *)skb->data;
+	if (gm->attrtype == 0)
+		return -1;
+	skb_pull(skb, sizeof(*gm));
+
+	while (skb->len > 0) {
+		if (garp_pdu_parse_attr(app, skb, gm->attrtype) < 0)
+			return -1;
+		if (garp_pdu_parse_end_mark(skb) < 0)
+			break;
+	}
+	return 0;
+}
+
+static void garp_pdu_rcv(const struct stp_proto *proto, struct sk_buff *skb,
+			 struct net_device *dev)
+{
+	struct garp_application *appl = proto->data;
+	struct garp_port *port;
+	struct garp_applicant *app;
+	const struct garp_pdu_hdr *gp;
+
+	port = rcu_dereference(dev->garp_port);
+	if (!port)
+		goto err;
+	app = rcu_dereference(port->applicants[appl->type]);
+	if (!app)
+		goto err;
+
+	if (!pskb_may_pull(skb, sizeof(*gp)))
+		goto err;
+	gp = (struct garp_pdu_hdr *)skb->data;
+	if (get_unaligned(&gp->protocol) != htons(GARP_PROTOCOL_ID))
+		goto err;
+	skb_pull(skb, sizeof(*gp));
+
+	spin_lock(&app->lock);
+	while (skb->len > 0) {
+		if (garp_pdu_parse_msg(app, skb) < 0)
+			break;
+		if (garp_pdu_parse_end_mark(skb) < 0)
+			break;
+	}
+	spin_unlock(&app->lock);
+err:
+	kfree_skb(skb);
+}
+
+static int garp_init_port(struct net_device *dev)
+{
+	struct garp_port *port;
+
+	port = kzalloc(sizeof(*port), GFP_KERNEL);
+	if (!port)
+		return -ENOMEM;
+	rcu_assign_pointer(dev->garp_port, port);
+	return 0;
+}
+
+static void garp_release_port(struct net_device *dev)
+{
+	struct garp_port *port = rtnl_dereference(dev->garp_port);
+	unsigned int i;
+
+	for (i = 0; i <= GARP_APPLICATION_MAX; i++) {
+		if (rtnl_dereference(port->applicants[i]))
+			return;
+	}
+	RCU_INIT_POINTER(dev->garp_port, NULL);
+	kfree_rcu(port, rcu);
+}
+
+int garp_init_applicant(struct net_device *dev, struct garp_application *appl)
+{
+	struct garp_applicant *app;
+	int err;
+
+	ASSERT_RTNL();
+
+	if (!rtnl_dereference(dev->garp_port)) {
+		err = garp_init_port(dev);
+		if (err < 0)
+			goto err1;
+	}
+
+	err = -ENOMEM;
+	app = kzalloc(sizeof(*app), GFP_KERNEL);
+	if (!app)
+		goto err2;
+
+	err = dev_mc_add(dev, appl->proto.group_address);
+	if (err < 0)
+		goto err3;
+
+	app->dev = dev;
+	app->app = appl;
+	app->gid = RB_ROOT;
+	spin_lock_init(&app->lock);
+	skb_queue_head_init(&app->queue);
+	rcu_assign_pointer(dev->garp_port->applicants[appl->type], app);
+	timer_setup(&app->join_timer, garp_join_timer, 0);
+	garp_join_timer_arm(app);
+	return 0;
+
+err3:
+	kfree(app);
+err2:
+	garp_release_port(dev);
+err1:
+	return err;
+}
+EXPORT_SYMBOL_GPL(garp_init_applicant);
+
+void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl)
+{
+	struct garp_port *port = rtnl_dereference(dev->garp_port);
+	struct garp_applicant *app = rtnl_dereference(port->applicants[appl->type]);
+
+	ASSERT_RTNL();
+
+	RCU_INIT_POINTER(port->applicants[appl->type], NULL);
+
+	/* Delete timer and generate a final TRANSMIT_PDU event to flush out
+	 * all pending messages before the applicant is gone. */
+	timer_shutdown_sync(&app->join_timer);
+
+	spin_lock_bh(&app->lock);
+	garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
+	garp_attr_destroy_all(app);
+	garp_pdu_queue(app);
+	spin_unlock_bh(&app->lock);
+
+	garp_queue_xmit(app);
+
+	dev_mc_del(dev, appl->proto.group_address);
+	kfree_rcu(app, rcu);
+	garp_release_port(dev);
+}
+EXPORT_SYMBOL_GPL(garp_uninit_applicant);
+
+int garp_register_application(struct garp_application *appl)
+{
+	appl->proto.rcv = garp_pdu_rcv;
+	appl->proto.data = appl;
+	return stp_proto_register(&appl->proto);
+}
+EXPORT_SYMBOL_GPL(garp_register_application);
+
+void garp_unregister_application(struct garp_application *appl)
+{
+	stp_proto_unregister(&appl->proto);
+}
+EXPORT_SYMBOL_GPL(garp_unregister_application);