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, 444 insertions, 0 deletions

diff --git a/include/net/llc_pdu.h b/include/net/llc_pdu.h
new file mode 100644
index 000000000..49aa79c7b
--- /dev/null
+++ b/include/net/llc_pdu.h
@@ -0,0 +1,444 @@
+#ifndef LLC_PDU_H
+#define LLC_PDU_H
+/*
+ * Copyright (c) 1997 by Procom Technology,Inc.
+ * 		 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program can be redistributed or modified under the terms of the
+ * GNU General Public License as published by the Free Software Foundation.
+ * This program is distributed without any warranty or implied warranty
+ * of merchantability or fitness for a particular purpose.
+ *
+ * See the GNU General Public License for more details.
+ */
+
+#include <linux/if_ether.h>
+
+/* Lengths of frame formats */
+#define LLC_PDU_LEN_I		4       /* header and 2 control bytes */
+#define LLC_PDU_LEN_S		4
+#define LLC_PDU_LEN_U		3       /* header and 1 control byte */
+/* header and 1 control byte and XID info */
+#define LLC_PDU_LEN_U_XID	(LLC_PDU_LEN_U + sizeof(struct llc_xid_info))
+/* Known SAP addresses */
+#define LLC_GLOBAL_SAP	0xFF
+#define LLC_NULL_SAP	0x00	/* not network-layer visible */
+#define LLC_MGMT_INDIV	0x02	/* station LLC mgmt indiv addr */
+#define LLC_MGMT_GRP	0x03	/* station LLC mgmt group addr */
+#define LLC_RDE_SAP	0xA6	/* route ... */
+
+/* SAP field bit masks */
+#define LLC_ISO_RESERVED_SAP	0x02
+#define LLC_SAP_GROUP_DSAP	0x01
+#define LLC_SAP_RESP_SSAP	0x01
+
+/* Group/individual DSAP indicator is DSAP field */
+#define LLC_PDU_GROUP_DSAP_MASK    0x01
+#define LLC_PDU_IS_GROUP_DSAP(pdu)      \
+	((pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
+#define LLC_PDU_IS_INDIV_DSAP(pdu)      \
+	(!(pdu->dsap & LLC_PDU_GROUP_DSAP_MASK) ? 0 : 1)
+
+/* Command/response PDU indicator in SSAP field */
+#define LLC_PDU_CMD_RSP_MASK	0x01
+#define LLC_PDU_CMD		0
+#define LLC_PDU_RSP		1
+#define LLC_PDU_IS_CMD(pdu)    ((pdu->ssap & LLC_PDU_RSP) ? 0 : 1)
+#define LLC_PDU_IS_RSP(pdu)    ((pdu->ssap & LLC_PDU_RSP) ? 1 : 0)
+
+/* Get PDU type from 2 lowest-order bits of control field first byte */
+#define LLC_PDU_TYPE_I_MASK    0x01	/* 16-bit control field */
+#define LLC_PDU_TYPE_S_MASK    0x03
+#define LLC_PDU_TYPE_U_MASK    0x03	/* 8-bit control field */
+#define LLC_PDU_TYPE_MASK      0x03
+
+#define LLC_PDU_TYPE_I		0	/* first bit */
+#define LLC_PDU_TYPE_S		1	/* first two bits */
+#define LLC_PDU_TYPE_U		3	/* first two bits */
+#define LLC_PDU_TYPE_U_XID	4	/* private type for detecting XID commands */
+
+#define LLC_PDU_TYPE_IS_I(pdu) \
+	((!(pdu->ctrl_1 & LLC_PDU_TYPE_I_MASK)) ? 1 : 0)
+
+#define LLC_PDU_TYPE_IS_U(pdu) \
+	(((pdu->ctrl_1 & LLC_PDU_TYPE_U_MASK) == LLC_PDU_TYPE_U) ? 1 : 0)
+
+#define LLC_PDU_TYPE_IS_S(pdu) \
+	(((pdu->ctrl_1 & LLC_PDU_TYPE_S_MASK) == LLC_PDU_TYPE_S) ? 1 : 0)
+
+/* U-format PDU control field masks */
+#define LLC_U_PF_BIT_MASK      0x10	/* P/F bit mask */
+#define LLC_U_PF_IS_1(pdu)     ((pdu->ctrl_1 & LLC_U_PF_BIT_MASK) ? 1 : 0)
+#define LLC_U_PF_IS_0(pdu)     ((!(pdu->ctrl_1 & LLC_U_PF_BIT_MASK)) ? 1 : 0)
+
+#define LLC_U_PDU_CMD_MASK     0xEC	/* cmd/rsp mask */
+#define LLC_U_PDU_CMD(pdu)     (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
+#define LLC_U_PDU_RSP(pdu)     (pdu->ctrl_1 & LLC_U_PDU_CMD_MASK)
+
+#define LLC_1_PDU_CMD_UI       0x00	/* Type 1 cmds/rsps */
+#define LLC_1_PDU_CMD_XID      0xAC
+#define LLC_1_PDU_CMD_TEST     0xE0
+
+#define LLC_2_PDU_CMD_SABME    0x6C	/* Type 2 cmds/rsps */
+#define LLC_2_PDU_CMD_DISC     0x40
+#define LLC_2_PDU_RSP_UA       0x60
+#define LLC_2_PDU_RSP_DM       0x0C
+#define LLC_2_PDU_RSP_FRMR     0x84
+
+/* Type 1 operations */
+
+/* XID information field bit masks */
+
+/* LLC format identifier (byte 1) */
+#define LLC_XID_FMT_ID		0x81	/* first byte must be this */
+
+/* LLC types/classes identifier (byte 2) */
+#define LLC_XID_CLASS_ZEROS_MASK	0xE0	/* these must be zeros */
+#define LLC_XID_CLASS_MASK		0x1F	/* AND with byte to get below */
+
+#define LLC_XID_NULL_CLASS_1	0x01	/* if NULL LSAP...use these */
+#define LLC_XID_NULL_CLASS_2	0x03
+#define LLC_XID_NULL_CLASS_3	0x05
+#define LLC_XID_NULL_CLASS_4	0x07
+
+#define LLC_XID_NNULL_TYPE_1	0x01	/* if non-NULL LSAP...use these */
+#define LLC_XID_NNULL_TYPE_2	0x02
+#define LLC_XID_NNULL_TYPE_3	0x04
+#define LLC_XID_NNULL_TYPE_1_2	0x03
+#define LLC_XID_NNULL_TYPE_1_3	0x05
+#define LLC_XID_NNULL_TYPE_2_3	0x06
+#define LLC_XID_NNULL_ALL		0x07
+
+/* Sender Receive Window (byte 3) */
+#define LLC_XID_RW_MASK	0xFE	/* AND with value to get below */
+
+#define LLC_XID_MIN_RW	0x02	/* lowest-order bit always zero */
+
+/* Type 2 operations */
+
+#define LLC_2_SEQ_NBR_MODULO   ((u8) 128)
+
+/* I-PDU masks ('ctrl' is I-PDU control word) */
+#define LLC_I_GET_NS(pdu)     (u8)((pdu->ctrl_1 & 0xFE) >> 1)
+#define LLC_I_GET_NR(pdu)     (u8)((pdu->ctrl_2 & 0xFE) >> 1)
+
+#define LLC_I_PF_BIT_MASK      0x01
+
+#define LLC_I_PF_IS_0(pdu)     ((!(pdu->ctrl_2 & LLC_I_PF_BIT_MASK)) ? 1 : 0)
+#define LLC_I_PF_IS_1(pdu)     ((pdu->ctrl_2 & LLC_I_PF_BIT_MASK) ? 1 : 0)
+
+/* S-PDU supervisory commands and responses */
+
+#define LLC_S_PDU_CMD_MASK     0x0C
+#define LLC_S_PDU_CMD(pdu)     (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
+#define LLC_S_PDU_RSP(pdu)     (pdu->ctrl_1 & LLC_S_PDU_CMD_MASK)
+
+#define LLC_2_PDU_CMD_RR       0x00	/* rx ready cmd */
+#define LLC_2_PDU_RSP_RR       0x00	/* rx ready rsp */
+#define LLC_2_PDU_CMD_REJ      0x08	/* reject PDU cmd */
+#define LLC_2_PDU_RSP_REJ      0x08	/* reject PDU rsp */
+#define LLC_2_PDU_CMD_RNR      0x04	/* rx not ready cmd */
+#define LLC_2_PDU_RSP_RNR      0x04	/* rx not ready rsp */
+
+#define LLC_S_PF_BIT_MASK      0x01
+#define LLC_S_PF_IS_0(pdu)     ((!(pdu->ctrl_2 & LLC_S_PF_BIT_MASK)) ? 1 : 0)
+#define LLC_S_PF_IS_1(pdu)     ((pdu->ctrl_2 & LLC_S_PF_BIT_MASK) ? 1 : 0)
+
+#define PDU_SUPV_GET_Nr(pdu)   ((pdu->ctrl_2 & 0xFE) >> 1)
+#define PDU_GET_NEXT_Vr(sn)    (((sn) + 1) & ~LLC_2_SEQ_NBR_MODULO)
+
+/* FRMR information field macros */
+
+#define FRMR_INFO_LENGTH       5	/* 5 bytes of information */
+
+/*
+ * info is pointer to FRMR info field structure; 'rej_ctrl' is byte pointer
+ * (if U-PDU) or word pointer to rejected PDU control field
+ */
+#define FRMR_INFO_SET_REJ_CNTRL(info,rej_ctrl) \
+	info->rej_pdu_ctrl = ((*((u8 *) rej_ctrl) & \
+				LLC_PDU_TYPE_U) != LLC_PDU_TYPE_U ? \
+				(u16)*((u16 *) rej_ctrl) : \
+				(((u16) *((u8 *) rej_ctrl)) & 0x00FF))
+
+/*
+ * Info is pointer to FRMR info field structure; 'vs' is a byte containing
+ * send state variable value in low-order 7 bits (insure the lowest-order
+ * bit remains zero (0))
+ */
+#define FRMR_INFO_SET_Vs(info,vs) (info->curr_ssv = (((u8) vs) << 1))
+#define FRMR_INFO_SET_Vr(info,vr) (info->curr_rsv = (((u8) vr) << 1))
+
+/*
+ * Info is pointer to FRMR info field structure; 'cr' is a byte containing
+ * the C/R bit value in the low-order bit
+ */
+#define FRMR_INFO_SET_C_R_BIT(info, cr)  (info->curr_rsv |= (((u8) cr) & 0x01))
+
+/*
+ * In the remaining five macros, 'info' is pointer to FRMR info field
+ * structure; 'ind' is a byte containing the bit value to set in the
+ * lowest-order bit)
+ */
+#define FRMR_INFO_SET_INVALID_PDU_CTRL_IND(info, ind) \
+       (info->ind_bits = ((info->ind_bits & 0xFE) | (((u8) ind) & 0x01)))
+
+#define FRMR_INFO_SET_INVALID_PDU_INFO_IND(info, ind) \
+       (info->ind_bits = ( (info->ind_bits & 0xFD) | (((u8) ind) & 0x02)))
+
+#define FRMR_INFO_SET_PDU_INFO_2LONG_IND(info, ind) \
+       (info->ind_bits = ( (info->ind_bits & 0xFB) | (((u8) ind) & 0x04)))
+
+#define FRMR_INFO_SET_PDU_INVALID_Nr_IND(info, ind) \
+       (info->ind_bits = ( (info->ind_bits & 0xF7) | (((u8) ind) & 0x08)))
+
+#define FRMR_INFO_SET_PDU_INVALID_Ns_IND(info, ind) \
+       (info->ind_bits = ( (info->ind_bits & 0xEF) | (((u8) ind) & 0x10)))
+
+/* Sequence-numbered PDU format (4 bytes in length) */
+struct llc_pdu_sn {
+	u8 dsap;
+	u8 ssap;
+	u8 ctrl_1;
+	u8 ctrl_2;
+} __packed;
+
+static inline struct llc_pdu_sn *llc_pdu_sn_hdr(struct sk_buff *skb)
+{
+	return (struct llc_pdu_sn *)skb_network_header(skb);
+}
+
+/* Un-numbered PDU format (3 bytes in length) */
+struct llc_pdu_un {
+	u8 dsap;
+	u8 ssap;
+	u8 ctrl_1;
+} __packed;
+
+static inline struct llc_pdu_un *llc_pdu_un_hdr(struct sk_buff *skb)
+{
+	return (struct llc_pdu_un *)skb_network_header(skb);
+}
+
+/**
+ *	llc_pdu_header_init - initializes pdu header
+ *	@skb: input skb that header must be set into it.
+ *	@type: type of PDU (U, I or S).
+ *	@ssap: source sap.
+ *	@dsap: destination sap.
+ *	@cr: command/response bit (0 or 1).
+ *
+ *	This function sets DSAP, SSAP and command/Response bit in LLC header.
+ */
+static inline void llc_pdu_header_init(struct sk_buff *skb, u8 type,
+				       u8 ssap, u8 dsap, u8 cr)
+{
+	int hlen = 4; /* default value for I and S types */
+	struct llc_pdu_un *pdu;
+
+	switch (type) {
+	case LLC_PDU_TYPE_U:
+		hlen = 3;
+		break;
+	case LLC_PDU_TYPE_U_XID:
+		hlen = 6;
+		break;
+	}
+
+	skb_push(skb, hlen);
+	skb_reset_network_header(skb);
+	pdu = llc_pdu_un_hdr(skb);
+	pdu->dsap = dsap;
+	pdu->ssap = ssap;
+	pdu->ssap |= cr;
+}
+
+/**
+ *	llc_pdu_decode_sa - extracs source address (MAC) of input frame
+ *	@skb: input skb that source address must be extracted from it.
+ *	@sa: pointer to source address (6 byte array).
+ *
+ *	This function extracts source address(MAC) of input frame.
+ */
+static inline void llc_pdu_decode_sa(struct sk_buff *skb, u8 *sa)
+{
+	if (skb->protocol == htons(ETH_P_802_2))
+		memcpy(sa, eth_hdr(skb)->h_source, ETH_ALEN);
+}
+
+/**
+ *	llc_pdu_decode_da - extracts dest address of input frame
+ *	@skb: input skb that destination address must be extracted from it
+ *	@sa: pointer to destination address (6 byte array).
+ *
+ *	This function extracts destination address(MAC) of input frame.
+ */
+static inline void llc_pdu_decode_da(struct sk_buff *skb, u8 *da)
+{
+	if (skb->protocol == htons(ETH_P_802_2))
+		memcpy(da, eth_hdr(skb)->h_dest, ETH_ALEN);
+}
+
+/**
+ *	llc_pdu_decode_ssap - extracts source SAP of input frame
+ *	@skb: input skb that source SAP must be extracted from it.
+ *	@ssap: source SAP (output argument).
+ *
+ *	This function extracts source SAP of input frame. Right bit of SSAP is
+ *	command/response bit.
+ */
+static inline void llc_pdu_decode_ssap(struct sk_buff *skb, u8 *ssap)
+{
+	*ssap = llc_pdu_un_hdr(skb)->ssap & 0xFE;
+}
+
+/**
+ *	llc_pdu_decode_dsap - extracts dest SAP of input frame
+ *	@skb: input skb that destination SAP must be extracted from it.
+ *	@dsap: destination SAP (output argument).
+ *
+ *	This function extracts destination SAP of input frame. right bit of
+ *	DSAP designates individual/group SAP.
+ */
+static inline void llc_pdu_decode_dsap(struct sk_buff *skb, u8 *dsap)
+{
+	*dsap = llc_pdu_un_hdr(skb)->dsap & 0xFE;
+}
+
+/**
+ *	llc_pdu_init_as_ui_cmd - sets LLC header as UI PDU
+ *	@skb: input skb that header must be set into it.
+ *
+ *	This function sets third byte of LLC header as a UI PDU.
+ */
+static inline void llc_pdu_init_as_ui_cmd(struct sk_buff *skb)
+{
+	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
+
+	pdu->ctrl_1  = LLC_PDU_TYPE_U;
+	pdu->ctrl_1 |= LLC_1_PDU_CMD_UI;
+}
+
+/**
+ *	llc_pdu_init_as_test_cmd - sets PDU as TEST
+ *	@skb - Address of the skb to build
+ *
+ * 	Sets a PDU as TEST
+ */
+static inline void llc_pdu_init_as_test_cmd(struct sk_buff *skb)
+{
+	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
+
+	pdu->ctrl_1  = LLC_PDU_TYPE_U;
+	pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST;
+	pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
+}
+
+/**
+ *	llc_pdu_init_as_test_rsp - build TEST response PDU
+ *	@skb: Address of the skb to build
+ *	@ev_skb: The received TEST command PDU frame
+ *
+ *	Builds a pdu frame as a TEST response.
+ */
+static inline void llc_pdu_init_as_test_rsp(struct sk_buff *skb,
+					    struct sk_buff *ev_skb)
+{
+	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
+
+	pdu->ctrl_1  = LLC_PDU_TYPE_U;
+	pdu->ctrl_1 |= LLC_1_PDU_CMD_TEST;
+	pdu->ctrl_1 |= LLC_U_PF_BIT_MASK;
+	if (ev_skb->protocol == htons(ETH_P_802_2)) {
+		struct llc_pdu_un *ev_pdu = llc_pdu_un_hdr(ev_skb);
+		int dsize;
+
+		dsize = ntohs(eth_hdr(ev_skb)->h_proto) - 3;
+		memcpy(((u8 *)pdu) + 3, ((u8 *)ev_pdu) + 3, dsize);
+		skb_put(skb, dsize);
+	}
+}
+
+/* LLC Type 1 XID command/response information fields format */
+struct llc_xid_info {
+	u8 fmt_id;	/* always 0x81 for LLC */
+	u8 type;	/* different if NULL/non-NULL LSAP */
+	u8 rw;		/* sender receive window */
+} __packed;
+
+/**
+ *	llc_pdu_init_as_xid_cmd - sets bytes 3, 4 & 5 of LLC header as XID
+ *	@skb: input skb that header must be set into it.
+ *
+ *	This function sets third,fourth,fifth and sixth bytes of LLC header as
+ *	a XID PDU.
+ */
+static inline void llc_pdu_init_as_xid_cmd(struct sk_buff *skb,
+					   u8 svcs_supported, u8 rx_window)
+{
+	struct llc_xid_info *xid_info;
+	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
+
+	pdu->ctrl_1	 = LLC_PDU_TYPE_U;
+	pdu->ctrl_1	|= LLC_1_PDU_CMD_XID;
+	pdu->ctrl_1	|= LLC_U_PF_BIT_MASK;
+	xid_info	 = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1);
+	xid_info->fmt_id = LLC_XID_FMT_ID;	/* 0x81 */
+	xid_info->type	 = svcs_supported;
+	xid_info->rw	 = rx_window << 1;	/* size of receive window */
+
+	/* no need to push/put since llc_pdu_header_init() has already
+	 * pushed 3 + 3 bytes
+	 */
+}
+
+/**
+ *	llc_pdu_init_as_xid_rsp - builds XID response PDU
+ *	@skb: Address of the skb to build
+ *	@svcs_supported: The class of the LLC (I or II)
+ *	@rx_window: The size of the receive window of the LLC
+ *
+ *	Builds a pdu frame as an XID response.
+ */
+static inline void llc_pdu_init_as_xid_rsp(struct sk_buff *skb,
+					   u8 svcs_supported, u8 rx_window)
+{
+	struct llc_xid_info *xid_info;
+	struct llc_pdu_un *pdu = llc_pdu_un_hdr(skb);
+
+	pdu->ctrl_1	 = LLC_PDU_TYPE_U;
+	pdu->ctrl_1	|= LLC_1_PDU_CMD_XID;
+	pdu->ctrl_1	|= LLC_U_PF_BIT_MASK;
+
+	xid_info	 = (struct llc_xid_info *)(((u8 *)&pdu->ctrl_1) + 1);
+	xid_info->fmt_id = LLC_XID_FMT_ID;
+	xid_info->type	 = svcs_supported;
+	xid_info->rw	 = rx_window << 1;
+	skb_put(skb, sizeof(struct llc_xid_info));
+}
+
+/* LLC Type 2 FRMR response information field format */
+struct llc_frmr_info {
+	u16 rej_pdu_ctrl;	/* bits 1-8 if U-PDU */
+	u8  curr_ssv;		/* current send state variable val */
+	u8  curr_rsv;		/* current receive state variable */
+	u8  ind_bits;		/* indicator bits set with macro */
+} __packed;
+
+void llc_pdu_set_cmd_rsp(struct sk_buff *skb, u8 type);
+void llc_pdu_set_pf_bit(struct sk_buff *skb, u8 bit_value);
+void llc_pdu_decode_pf_bit(struct sk_buff *skb, u8 *pf_bit);
+void llc_pdu_init_as_disc_cmd(struct sk_buff *skb, u8 p_bit);
+void llc_pdu_init_as_i_cmd(struct sk_buff *skb, u8 p_bit, u8 ns, u8 nr);
+void llc_pdu_init_as_rej_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
+void llc_pdu_init_as_rnr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
+void llc_pdu_init_as_rr_cmd(struct sk_buff *skb, u8 p_bit, u8 nr);
+void llc_pdu_init_as_sabme_cmd(struct sk_buff *skb, u8 p_bit);
+void llc_pdu_init_as_dm_rsp(struct sk_buff *skb, u8 f_bit);
+void llc_pdu_init_as_frmr_rsp(struct sk_buff *skb, struct llc_pdu_sn *prev_pdu,
+			      u8 f_bit, u8 vs, u8 vr, u8 vzyxw);
+void llc_pdu_init_as_rr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
+void llc_pdu_init_as_rej_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
+void llc_pdu_init_as_rnr_rsp(struct sk_buff *skb, u8 f_bit, u8 nr);
+void llc_pdu_init_as_ua_rsp(struct sk_buff *skb, u8 f_bit);
+#endif /* LLC_PDU_H */