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, 184 insertions, 0 deletions

diff --git a/Documentation/networking/segmentation-offloads.rst b/Documentation/networking/segmentation-offloads.rst
new file mode 100644
index 000000000..085e8fab0
--- /dev/null
+++ b/Documentation/networking/segmentation-offloads.rst
@@ -0,0 +1,184 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+Segmentation Offloads
+=====================
+
+
+Introduction
+============
+
+This document describes a set of techniques in the Linux networking stack
+to take advantage of segmentation offload capabilities of various NICs.
+
+The following technologies are described:
+ * TCP Segmentation Offload - TSO
+ * UDP Fragmentation Offload - UFO
+ * IPIP, SIT, GRE, and UDP Tunnel Offloads
+ * Generic Segmentation Offload - GSO
+ * Generic Receive Offload - GRO
+ * Partial Generic Segmentation Offload - GSO_PARTIAL
+ * SCTP acceleration with GSO - GSO_BY_FRAGS
+
+
+TCP Segmentation Offload
+========================
+
+TCP segmentation allows a device to segment a single frame into multiple
+frames with a data payload size specified in skb_shinfo()->gso_size.
+When TCP segmentation requested the bit for either SKB_GSO_TCPV4 or
+SKB_GSO_TCPV6 should be set in skb_shinfo()->gso_type and
+skb_shinfo()->gso_size should be set to a non-zero value.
+
+TCP segmentation is dependent on support for the use of partial checksum
+offload.  For this reason TSO is normally disabled if the Tx checksum
+offload for a given device is disabled.
+
+In order to support TCP segmentation offload it is necessary to populate
+the network and transport header offsets of the skbuff so that the device
+drivers will be able determine the offsets of the IP or IPv6 header and the
+TCP header.  In addition as CHECKSUM_PARTIAL is required csum_start should
+also point to the TCP header of the packet.
+
+For IPv4 segmentation we support one of two types in terms of the IP ID.
+The default behavior is to increment the IP ID with every segment.  If the
+GSO type SKB_GSO_TCP_FIXEDID is specified then we will not increment the IP
+ID and all segments will use the same IP ID.  If a device has
+NETIF_F_TSO_MANGLEID set then the IP ID can be ignored when performing TSO
+and we will either increment the IP ID for all frames, or leave it at a
+static value based on driver preference.
+
+
+UDP Fragmentation Offload
+=========================
+
+UDP fragmentation offload allows a device to fragment an oversized UDP
+datagram into multiple IPv4 fragments.  Many of the requirements for UDP
+fragmentation offload are the same as TSO.  However the IPv4 ID for
+fragments should not increment as a single IPv4 datagram is fragmented.
+
+UFO is deprecated: modern kernels will no longer generate UFO skbs, but can
+still receive them from tuntap and similar devices. Offload of UDP-based
+tunnel protocols is still supported.
+
+
+IPIP, SIT, GRE, UDP Tunnel, and Remote Checksum Offloads
+========================================================
+
+In addition to the offloads described above it is possible for a frame to
+contain additional headers such as an outer tunnel.  In order to account
+for such instances an additional set of segmentation offload types were
+introduced including SKB_GSO_IPXIP4, SKB_GSO_IPXIP6, SKB_GSO_GRE, and
+SKB_GSO_UDP_TUNNEL.  These extra segmentation types are used to identify
+cases where there are more than just 1 set of headers.  For example in the
+case of IPIP and SIT we should have the network and transport headers moved
+from the standard list of headers to "inner" header offsets.
+
+Currently only two levels of headers are supported.  The convention is to
+refer to the tunnel headers as the outer headers, while the encapsulated
+data is normally referred to as the inner headers.  Below is the list of
+calls to access the given headers:
+
+IPIP/SIT Tunnel::
+
+             Outer                  Inner
+  MAC        skb_mac_header
+  Network    skb_network_header     skb_inner_network_header
+  Transport  skb_transport_header
+
+UDP/GRE Tunnel::
+
+             Outer                  Inner
+  MAC        skb_mac_header         skb_inner_mac_header
+  Network    skb_network_header     skb_inner_network_header
+  Transport  skb_transport_header   skb_inner_transport_header
+
+In addition to the above tunnel types there are also SKB_GSO_GRE_CSUM and
+SKB_GSO_UDP_TUNNEL_CSUM.  These two additional tunnel types reflect the
+fact that the outer header also requests to have a non-zero checksum
+included in the outer header.
+
+Finally there is SKB_GSO_TUNNEL_REMCSUM which indicates that a given tunnel
+header has requested a remote checksum offload.  In this case the inner
+headers will be left with a partial checksum and only the outer header
+checksum will be computed.
+
+
+Generic Segmentation Offload
+============================
+
+Generic segmentation offload is a pure software offload that is meant to
+deal with cases where device drivers cannot perform the offloads described
+above.  What occurs in GSO is that a given skbuff will have its data broken
+out over multiple skbuffs that have been resized to match the MSS provided
+via skb_shinfo()->gso_size.
+
+Before enabling any hardware segmentation offload a corresponding software
+offload is required in GSO.  Otherwise it becomes possible for a frame to
+be re-routed between devices and end up being unable to be transmitted.
+
+
+Generic Receive Offload
+=======================
+
+Generic receive offload is the complement to GSO.  Ideally any frame
+assembled by GRO should be segmented to create an identical sequence of
+frames using GSO, and any sequence of frames segmented by GSO should be
+able to be reassembled back to the original by GRO.  The only exception to
+this is IPv4 ID in the case that the DF bit is set for a given IP header.
+If the value of the IPv4 ID is not sequentially incrementing it will be
+altered so that it is when a frame assembled via GRO is segmented via GSO.
+
+
+Partial Generic Segmentation Offload
+====================================
+
+Partial generic segmentation offload is a hybrid between TSO and GSO.  What
+it effectively does is take advantage of certain traits of TCP and tunnels
+so that instead of having to rewrite the packet headers for each segment
+only the inner-most transport header and possibly the outer-most network
+header need to be updated.  This allows devices that do not support tunnel
+offloads or tunnel offloads with checksum to still make use of segmentation.
+
+With the partial offload what occurs is that all headers excluding the
+inner transport header are updated such that they will contain the correct
+values for if the header was simply duplicated.  The one exception to this
+is the outer IPv4 ID field.  It is up to the device drivers to guarantee
+that the IPv4 ID field is incremented in the case that a given header does
+not have the DF bit set.
+
+
+SCTP acceleration with GSO
+===========================
+
+SCTP - despite the lack of hardware support - can still take advantage of
+GSO to pass one large packet through the network stack, rather than
+multiple small packets.
+
+This requires a different approach to other offloads, as SCTP packets
+cannot be just segmented to (P)MTU. Rather, the chunks must be contained in
+IP segments, padding respected. So unlike regular GSO, SCTP can't just
+generate a big skb, set gso_size to the fragmentation point and deliver it
+to IP layer.
+
+Instead, the SCTP protocol layer builds an skb with the segments correctly
+padded and stored as chained skbs, and skb_segment() splits based on those.
+To signal this, gso_size is set to the special value GSO_BY_FRAGS.
+
+Therefore, any code in the core networking stack must be aware of the
+possibility that gso_size will be GSO_BY_FRAGS and handle that case
+appropriately.
+
+There are some helpers to make this easier:
+
+- skb_is_gso(skb) && skb_is_gso_sctp(skb) is the best way to see if
+  an skb is an SCTP GSO skb.
+
+- For size checks, the skb_gso_validate_*_len family of helpers correctly
+  considers GSO_BY_FRAGS.
+
+- For manipulating packets, skb_increase_gso_size and skb_decrease_gso_size
+  will check for GSO_BY_FRAGS and WARN if asked to manipulate these skbs.
+
+This also affects drivers with the NETIF_F_FRAGLIST & NETIF_F_GSO_SCTP bits
+set. Note also that NETIF_F_GSO_SCTP is included in NETIF_F_GSO_SOFTWARE.