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author | 2023-02-21 18:24:12 -0800 | |
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committer | 2023-02-21 18:24:12 -0800 | |
commit | 5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch) | |
tree | cc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/networking/6pack.rst | |
download | linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip |
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().
...
Diffstat (limited to 'Documentation/networking/6pack.rst')
-rw-r--r-- | Documentation/networking/6pack.rst | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/Documentation/networking/6pack.rst b/Documentation/networking/6pack.rst new file mode 100644 index 000000000..bc5bf1f1a --- /dev/null +++ b/Documentation/networking/6pack.rst @@ -0,0 +1,191 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============== +6pack Protocol +============== + +This is the 6pack-mini-HOWTO, written by + +Andreas Könsgen DG3KQ + +:Internet: ajk@comnets.uni-bremen.de +:AMPR-net: dg3kq@db0pra.ampr.org +:AX.25: dg3kq@db0ach.#nrw.deu.eu + +Last update: April 7, 1998 + +1. What is 6pack, and what are the advantages to KISS? +====================================================== + +6pack is a transmission protocol for data exchange between the PC and +the TNC over a serial line. It can be used as an alternative to KISS. + +6pack has two major advantages: + +- The PC is given full control over the radio + channel. Special control data is exchanged between the PC and the TNC so + that the PC knows at any time if the TNC is receiving data, if a TNC + buffer underrun or overrun has occurred, if the PTT is + set and so on. This control data is processed at a higher priority than + normal data, so a data stream can be interrupted at any time to issue an + important event. This helps to improve the channel access and timing + algorithms as everything is computed in the PC. It would even be possible + to experiment with something completely different from the known CSMA and + DAMA channel access methods. + This kind of real-time control is especially important to supply several + TNCs that are connected between each other and the PC by a daisy chain + (however, this feature is not supported yet by the Linux 6pack driver). + +- Each packet transferred over the serial line is supplied with a checksum, + so it is easy to detect errors due to problems on the serial line. + Received packets that are corrupt are not passed on to the AX.25 layer. + Damaged packets that the TNC has received from the PC are not transmitted. + +More details about 6pack are described in the file 6pack.ps that is located +in the doc directory of the AX.25 utilities package. + +2. Who has developed the 6pack protocol? +======================================== + +The 6pack protocol has been developed by Ekki Plicht DF4OR, Henning Rech +DF9IC and Gunter Jost DK7WJ. A driver for 6pack, written by Gunter Jost and +Matthias Welwarsky DG2FEF, comes along with the PC version of FlexNet. +They have also written a firmware for TNCs to perform the 6pack +protocol (see section 4 below). + +3. Where can I get the latest version of 6pack for LinuX? +========================================================= + +At the moment, the 6pack stuff can obtained via anonymous ftp from +db0bm.automation.fh-aachen.de. In the directory /incoming/dg3kq, +there is a file named 6pack.tgz. + +4. Preparing the TNC for 6pack operation +======================================== + +To be able to use 6pack, a special firmware for the TNC is needed. The EPROM +of a newly bought TNC does not contain 6pack, so you will have to +program an EPROM yourself. The image file for 6pack EPROMs should be +available on any packet radio box where PC/FlexNet can be found. The name of +the file is 6pack.bin. This file is copyrighted and maintained by the FlexNet +team. It can be used under the terms of the license that comes along +with PC/FlexNet. Please do not ask me about the internals of this file as I +don't know anything about it. I used a textual description of the 6pack +protocol to program the Linux driver. + +TNCs contain a 64kByte EPROM, the lower half of which is used for +the firmware/KISS. The upper half is either empty or is sometimes +programmed with software called TAPR. In the latter case, the TNC +is supplied with a DIP switch so you can easily change between the +two systems. When programming a new EPROM, one of the systems is replaced +by 6pack. It is useful to replace TAPR, as this software is rarely used +nowadays. If your TNC is not equipped with the switch mentioned above, you +can build in one yourself that switches over the highest address pin +of the EPROM between HIGH and LOW level. After having inserted the new EPROM +and switched to 6pack, apply power to the TNC for a first test. The connect +and the status LED are lit for about a second if the firmware initialises +the TNC correctly. + +5. Building and installing the 6pack driver +=========================================== + +The driver has been tested with kernel version 2.1.90. Use with older +kernels may lead to a compilation error because the interface to a kernel +function has been changed in the 2.1.8x kernels. + +How to turn on 6pack support: +============================= + +- In the linux kernel configuration program, select the code maturity level + options menu and turn on the prompting for development drivers. + +- Select the amateur radio support menu and turn on the serial port 6pack + driver. + +- Compile and install the kernel and the modules. + +To use the driver, the kissattach program delivered with the AX.25 utilities +has to be modified. + +- Do a cd to the directory that holds the kissattach sources. Edit the + kissattach.c file. At the top, insert the following lines:: + + #ifndef N_6PACK + #define N_6PACK (N_AX25+1) + #endif + + Then find the line: + + int disc = N_AX25; + + and replace N_AX25 by N_6PACK. + +- Recompile kissattach. Rename it to spattach to avoid confusions. + +Installing the driver: +---------------------- + +- Do an insmod 6pack. Look at your /var/log/messages file to check if the + module has printed its initialization message. + +- Do a spattach as you would launch kissattach when starting a KISS port. + Check if the kernel prints the message '6pack: TNC found'. + +- From here, everything should work as if you were setting up a KISS port. + The only difference is that the network device that represents + the 6pack port is called sp instead of sl or ax. So, sp0 would be the + first 6pack port. + +Although the driver has been tested on various platforms, I still declare it +ALPHA. BE CAREFUL! Sync your disks before insmoding the 6pack module +and spattaching. Watch out if your computer behaves strangely. Read section +6 of this file about known problems. + +Note that the connect and status LEDs of the TNC are controlled in a +different way than they are when the TNC is used with PC/FlexNet. When using +FlexNet, the connect LED is on if there is a connection; the status LED is +on if there is data in the buffer of the PC's AX.25 engine that has to be +transmitted. Under Linux, the 6pack layer is beyond the AX.25 layer, +so the 6pack driver doesn't know anything about connects or data that +has not yet been transmitted. Therefore the LEDs are controlled +as they are in KISS mode: The connect LED is turned on if data is transferred +from the PC to the TNC over the serial line, the status LED if data is +sent to the PC. + +6. Known problems +================= + +When testing the driver with 2.0.3x kernels and +operating with data rates on the radio channel of 9600 Baud or higher, +the driver may, on certain systems, sometimes print the message '6pack: +bad checksum', which is due to data loss if the other station sends two +or more subsequent packets. I have been told that this is due to a problem +with the serial driver of 2.0.3x kernels. I don't know yet if the problem +still exists with 2.1.x kernels, as I have heard that the serial driver +code has been changed with 2.1.x. + +When shutting down the sp interface with ifconfig, the kernel crashes if +there is still an AX.25 connection left over which an IP connection was +running, even if that IP connection is already closed. The problem does not +occur when there is a bare AX.25 connection still running. I don't know if +this is a problem of the 6pack driver or something else in the kernel. + +The driver has been tested as a module, not yet as a kernel-builtin driver. + +The 6pack protocol supports daisy-chaining of TNCs in a token ring, which is +connected to one serial port of the PC. This feature is not implemented +and at least at the moment I won't be able to do it because I do not have +the opportunity to build a TNC daisy-chain and test it. + +Some of the comments in the source code are inaccurate. They are left from +the SLIP/KISS driver, from which the 6pack driver has been derived. +I haven't modified or removed them yet -- sorry! The code itself needs +some cleaning and optimizing. This will be done in a later release. + +If you encounter a bug or if you have a question or suggestion concerning the +driver, feel free to mail me, using the addresses given at the beginning of +this file. + +Have fun! + +Andreas |