diff options
Diffstat (limited to 'Documentation/networking')
20 files changed, 1077 insertions, 97 deletions
diff --git a/Documentation/networking/00-INDEX b/Documentation/networking/00-INDEX index 50189bf07d53..fe5c099b8fc8 100644 --- a/Documentation/networking/00-INDEX +++ b/Documentation/networking/00-INDEX @@ -32,6 +32,8 @@ cs89x0.txt - the Crystal LAN (CS8900/20-based) Ethernet ISA adapter driver cxacru.txt - Conexant AccessRunner USB ADSL Modem +cxacru-cf.py + - Conexant AccessRunner USB ADSL Modem configuration file parser de4x5.txt - the Digital EtherWORKS DE4?? and DE5?? PCI Ethernet driver decnet.txt diff --git a/Documentation/networking/Makefile b/Documentation/networking/Makefile index 6d8af1ac56c4..5aba7a33aeeb 100644 --- a/Documentation/networking/Makefile +++ b/Documentation/networking/Makefile @@ -6,3 +6,5 @@ hostprogs-y := ifenslave # Tell kbuild to always build the programs always := $(hostprogs-y) + +obj-m := timestamping/ diff --git a/Documentation/networking/caif/Linux-CAIF.txt b/Documentation/networking/caif/Linux-CAIF.txt new file mode 100644 index 000000000000..7fe7a9a33a4f --- /dev/null +++ b/Documentation/networking/caif/Linux-CAIF.txt @@ -0,0 +1,212 @@ +Linux CAIF +=========== +copyright (C) ST-Ericsson AB 2010 +Author: Sjur Brendeland/ sjur.brandeland@stericsson.com +License terms: GNU General Public License (GPL) version 2 + + +Introduction +------------ +CAIF is a MUX protocol used by ST-Ericsson cellular modems for +communication between Modem and host. The host processes can open virtual AT +channels, initiate GPRS Data connections, Video channels and Utility Channels. +The Utility Channels are general purpose pipes between modem and host. + +ST-Ericsson modems support a number of transports between modem +and host. Currently, UART and Loopback are available for Linux. + + +Architecture: +------------ +The implementation of CAIF is divided into: +* CAIF Socket Layer, Kernel API, and Net Device. +* CAIF Core Protocol Implementation +* CAIF Link Layer, implemented as NET devices. + + + RTNL + ! + ! +------+ +------+ +------+ + ! +------+! +------+! +------+! + ! ! Sock !! !Kernel!! ! Net !! + ! ! API !+ ! API !+ ! Dev !+ <- CAIF Client APIs + ! +------+ +------! +------+ + ! ! ! ! + ! +----------!----------+ + ! +------+ <- CAIF Protocol Implementation + +-------> ! CAIF ! + ! Core ! + +------+ + +--------!--------+ + ! ! + +------+ +-----+ + ! ! ! TTY ! <- Link Layer (Net Devices) + +------+ +-----+ + + +Using the Kernel API +---------------------- +The Kernel API is used for accessing CAIF channels from the +kernel. +The user of the API has to implement two callbacks for receive +and control. +The receive callback gives a CAIF packet as a SKB. The control +callback will +notify of channel initialization complete, and flow-on/flow- +off. + + + struct caif_device caif_dev = { + .caif_config = { + .name = "MYDEV" + .type = CAIF_CHTY_AT + } + .receive_cb = my_receive, + .control_cb = my_control, + }; + caif_add_device(&caif_dev); + caif_transmit(&caif_dev, skb); + +See the caif_kernel.h for details about the CAIF kernel API. + + +I M P L E M E N T A T I O N +=========================== +=========================== + +CAIF Core Protocol Layer +========================================= + +CAIF Core layer implements the CAIF protocol as defined by ST-Ericsson. +It implements the CAIF protocol stack in a layered approach, where +each layer described in the specification is implemented as a separate layer. +The architecture is inspired by the design patterns "Protocol Layer" and +"Protocol Packet". + +== CAIF structure == +The Core CAIF implementation contains: + - Simple implementation of CAIF. + - Layered architecture (a la Streams), each layer in the CAIF + specification is implemented in a separate c-file. + - Clients must implement PHY layer to access physical HW + with receive and transmit functions. + - Clients must call configuration function to add PHY layer. + - Clients must implement CAIF layer to consume/produce + CAIF payload with receive and transmit functions. + - Clients must call configuration function to add and connect the + Client layer. + - When receiving / transmitting CAIF Packets (cfpkt), ownership is passed + to the called function (except for framing layers' receive functions + or if a transmit function returns an error, in which case the caller + must free the packet). + +Layered Architecture +-------------------- +The CAIF protocol can be divided into two parts: Support functions and Protocol +Implementation. The support functions include: + + - CFPKT CAIF Packet. Implementation of CAIF Protocol Packet. The + CAIF Packet has functions for creating, destroying and adding content + and for adding/extracting header and trailers to protocol packets. + + - CFLST CAIF list implementation. + + - CFGLUE CAIF Glue. Contains OS Specifics, such as memory + allocation, endianness, etc. + +The CAIF Protocol implementation contains: + + - CFCNFG CAIF Configuration layer. Configures the CAIF Protocol + Stack and provides a Client interface for adding Link-Layer and + Driver interfaces on top of the CAIF Stack. + + - CFCTRL CAIF Control layer. Encodes and Decodes control messages + such as enumeration and channel setup. Also matches request and + response messages. + + - CFSERVL General CAIF Service Layer functionality; handles flow + control and remote shutdown requests. + + - CFVEI CAIF VEI layer. Handles CAIF AT Channels on VEI (Virtual + External Interface). This layer encodes/decodes VEI frames. + + - CFDGML CAIF Datagram layer. Handles CAIF Datagram layer (IP + traffic), encodes/decodes Datagram frames. + + - CFMUX CAIF Mux layer. Handles multiplexing between multiple + physical bearers and multiple channels such as VEI, Datagram, etc. + The MUX keeps track of the existing CAIF Channels and + Physical Instances and selects the apropriate instance based + on Channel-Id and Physical-ID. + + - CFFRML CAIF Framing layer. Handles Framing i.e. Frame length + and frame checksum. + + - CFSERL CAIF Serial layer. Handles concatenation/split of frames + into CAIF Frames with correct length. + + + + +---------+ + | Config | + | CFCNFG | + +---------+ + ! + +---------+ +---------+ +---------+ + | AT | | Control | | Datagram| + | CFVEIL | | CFCTRL | | CFDGML | + +---------+ +---------+ +---------+ + \_____________!______________/ + ! + +---------+ + | MUX | + | | + +---------+ + _____!_____ + / \ + +---------+ +---------+ + | CFFRML | | CFFRML | + | Framing | | Framing | + +---------+ +---------+ + ! ! + +---------+ +---------+ + | | | Serial | + | | | CFSERL | + +---------+ +---------+ + + +In this layered approach the following "rules" apply. + - All layers embed the same structure "struct cflayer" + - A layer does not depend on any other layer's private data. + - Layers are stacked by setting the pointers + layer->up , layer->dn + - In order to send data upwards, each layer should do + layer->up->receive(layer->up, packet); + - In order to send data downwards, each layer should do + layer->dn->transmit(layer->dn, packet); + + +Linux Driver Implementation +=========================== + +Linux GPRS Net Device and CAIF socket are implemented on top of the +CAIF Core protocol. The Net device and CAIF socket have an instance of +'struct cflayer', just like the CAIF Core protocol stack. +Net device and Socket implement the 'receive()' function defined by +'struct cflayer', just like the rest of the CAIF stack. In this way, transmit and +receive of packets is handled as by the rest of the layers: the 'dn->transmit()' +function is called in order to transmit data. + +The layer on top of the CAIF Core implementation is +sometimes referred to as the "Client layer". + + +Configuration of Link Layer +--------------------------- +The Link Layer is implemented as Linux net devices (struct net_device). +Payload handling and registration is done using standard Linux mechanisms. + +The CAIF Protocol relies on a loss-less link layer without implementing +retransmission. This implies that packet drops must not happen. +Therefore a flow-control mechanism is implemented where the physical +interface can initiate flow stop for all CAIF Channels. diff --git a/Documentation/networking/caif/README b/Documentation/networking/caif/README new file mode 100644 index 000000000000..757ccfaa1385 --- /dev/null +++ b/Documentation/networking/caif/README @@ -0,0 +1,109 @@ +Copyright (C) ST-Ericsson AB 2010 +Author: Sjur Brendeland/ sjur.brandeland@stericsson.com +License terms: GNU General Public License (GPL) version 2 +--------------------------------------------------------- + +=== Start === +If you have compiled CAIF for modules do: + +$modprobe crc_ccitt +$modprobe caif +$modprobe caif_socket +$modprobe chnl_net + + +=== Preparing the setup with a STE modem === + +If you are working on integration of CAIF you should make sure +that the kernel is built with module support. + +There are some things that need to be tweaked to get the host TTY correctly +set up to talk to the modem. +Since the CAIF stack is running in the kernel and we want to use the existing +TTY, we are installing our physical serial driver as a line discipline above +the TTY device. + +To achieve this we need to install the N_CAIF ldisc from user space. +The benefit is that we can hook up to any TTY. + +The use of Start-of-frame-extension (STX) must also be set as +module parameter "ser_use_stx". + +Normally Frame Checksum is always used on UART, but this is also provided as a +module parameter "ser_use_fcs". + +$ modprobe caif_serial ser_ttyname=/dev/ttyS0 ser_use_stx=yes +$ ifconfig caif_ttyS0 up + +PLEASE NOTE: There is a limitation in Android shell. + It only accepts one argument to insmod/modprobe! + +=== Trouble shooting === + +There are debugfs parameters provided for serial communication. +/sys/kernel/debug/caif_serial/<tty-name>/ + +* ser_state: Prints the bit-mask status where + - 0x02 means SENDING, this is a transient state. + - 0x10 means FLOW_OFF_SENT, i.e. the previous frame has not been sent + and is blocking further send operation. Flow OFF has been propagated + to all CAIF Channels using this TTY. + +* tty_status: Prints the bit-mask tty status information + - 0x01 - tty->warned is on. + - 0x02 - tty->low_latency is on. + - 0x04 - tty->packed is on. + - 0x08 - tty->flow_stopped is on. + - 0x10 - tty->hw_stopped is on. + - 0x20 - tty->stopped is on. + +* last_tx_msg: Binary blob Prints the last transmitted frame. + This can be printed with + $od --format=x1 /sys/kernel/debug/caif_serial/<tty>/last_rx_msg. + The first two tx messages sent look like this. Note: The initial + byte 02 is start of frame extension (STX) used for re-syncing + upon errors. + + - Enumeration: + 0000000 02 05 00 00 03 01 d2 02 + | | | | | | + STX(1) | | | | + Length(2)| | | + Control Channel(1) + Command:Enumeration(1) + Link-ID(1) + Checksum(2) + - Channel Setup: + 0000000 02 07 00 00 00 21 a1 00 48 df + | | | | | | | | + STX(1) | | | | | | + Length(2)| | | | | + Control Channel(1) + Command:Channel Setup(1) + Channel Type(1) + Priority and Link-ID(1) + Endpoint(1) + Checksum(2) + +* last_rx_msg: Prints the last transmitted frame. + The RX messages for LinkSetup look almost identical but they have the + bit 0x20 set in the command bit, and Channel Setup has added one byte + before Checksum containing Channel ID. + NOTE: Several CAIF Messages might be concatenated. The maximum debug + buffer size is 128 bytes. + +== Error Scenarios: +- last_tx_msg contains channel setup message and last_rx_msg is empty -> + The host seems to be able to send over the UART, at least the CAIF ldisc get + notified that sending is completed. + +- last_tx_msg contains enumeration message and last_rx_msg is empty -> + The host is not able to send the message from UART, the tty has not been + able to complete the transmit operation. + +- if /sys/kernel/debug/caif_serial/<tty>/tty_status is non-zero there + might be problems transmitting over UART. + E.g. host and modem wiring is not correct you will typically see + tty_status = 0x10 (hw_stopped) and ser_state = 0x10 (FLOW_OFF_SENT). + You will probably see the enumeration message in last_tx_message + and empty last_rx_message. diff --git a/Documentation/networking/cxacru-cf.py b/Documentation/networking/cxacru-cf.py new file mode 100644 index 000000000000..b41d298398c8 --- /dev/null +++ b/Documentation/networking/cxacru-cf.py @@ -0,0 +1,48 @@ +#!/usr/bin/env python +# Copyright 2009 Simon Arlott +# +# This program is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by the Free +# Software Foundation; either version 2 of the License, or (at your option) +# any later version. +# +# This program is distributed in the hope that it will be useful, but WITHOUT +# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for +# more details. +# +# You should have received a copy of the GNU General Public License along with +# this program; if not, write to the Free Software Foundation, Inc., 59 +# Temple Place - Suite 330, Boston, MA 02111-1307, USA. +# +# Usage: cxacru-cf.py < cxacru-cf.bin +# Output: values string suitable for the sysfs adsl_config attribute +# +# Warning: cxacru-cf.bin with MD5 hash cdbac2689969d5ed5d4850f117702110 +# contains mis-aligned values which will stop the modem from being able +# to make a connection. If the first and last two bytes are removed then +# the values become valid, but the modulation will be forced to ANSI +# T1.413 only which may not be appropriate. +# +# The original binary format is a packed list of le32 values. + +import sys +import struct + +i = 0 +while True: + buf = sys.stdin.read(4) + + if len(buf) == 0: + break + elif len(buf) != 4: + sys.stdout.write("\n") + sys.stderr.write("Error: read {0} not 4 bytes\n".format(len(buf))) + sys.exit(1) + + if i > 0: + sys.stdout.write(" ") + sys.stdout.write("{0:x}={1}".format(i, struct.unpack("<I", buf)[0])) + i += 1 + +sys.stdout.write("\n") diff --git a/Documentation/networking/cxacru.txt b/Documentation/networking/cxacru.txt index b074681a963e..2cce04457b4d 100644 --- a/Documentation/networking/cxacru.txt +++ b/Documentation/networking/cxacru.txt @@ -4,6 +4,12 @@ While it is capable of managing/maintaining the ADSL connection without the module loaded, the device will sometimes stop responding after unloading the driver and it is necessary to unplug/remove power to the device to fix this. +Note: support for cxacru-cf.bin has been removed. It was not loaded correctly +so it had no effect on the device configuration. Fixing it could have stopped +existing devices working when an invalid configuration is supplied. + +There is a script cxacru-cf.py to convert an existing file to the sysfs form. + Detected devices will appear as ATM devices named "cxacru". In /sys/class/atm/ these are directories named cxacruN where N is the device number. A symlink named device points to the USB interface device's directory which contains @@ -15,6 +21,15 @@ several sysfs attribute files for retrieving device statistics: * adsl_headend_environment Information about the remote headend. +* adsl_config + Configuration writing interface. + Write parameters in hexadecimal format <index>=<value>, + separated by whitespace, e.g.: + "1=0 a=5" + Up to 7 parameters at a time will be sent and the modem will restart + the ADSL connection when any value is set. These are logged for future + reference. + * downstream_attenuation (dB) * downstream_bits_per_frame * downstream_rate (kbps) @@ -61,6 +76,7 @@ several sysfs attribute files for retrieving device statistics: * mac_address * modulation + "" (when not connected) "ANSI T1.413" "ITU-T G.992.1 (G.DMT)" "ITU-T G.992.2 (G.LITE)" diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt index b132e4a3cf0f..a62fdf7a6bff 100644 --- a/Documentation/networking/dccp.txt +++ b/Documentation/networking/dccp.txt @@ -58,8 +58,10 @@ DCCP_SOCKOPT_GET_CUR_MPS is read-only and retrieves the current maximum packet size (application payload size) in bytes, see RFC 4340, section 14. DCCP_SOCKOPT_AVAILABLE_CCIDS is also read-only and returns the list of CCIDs -supported by the endpoint (see include/linux/dccp.h for symbolic constants). -The caller needs to provide a sufficiently large (> 2) array of type uint8_t. +supported by the endpoint. The option value is an array of type uint8_t whose +size is passed as option length. The minimum array size is 4 elements, the +value returned in the optlen argument always reflects the true number of +built-in CCIDs. DCCP_SOCKOPT_CCID is write-only and sets both the TX and RX CCIDs at the same time, combining the operation of the next two socket options. This option is diff --git a/Documentation/networking/ifenslave.c b/Documentation/networking/ifenslave.c index 1b96ccda3836..2bac9618c345 100644 --- a/Documentation/networking/ifenslave.c +++ b/Documentation/networking/ifenslave.c @@ -756,7 +756,7 @@ static int enslave(char *master_ifname, char *slave_ifname) */ if (abi_ver < 1) { /* For old ABI, the master needs to be - * down before setting it's hwaddr + * down before setting its hwaddr */ res = set_if_down(master_ifname, master_flags.ifr_flags); if (res) { diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 006b39dec87d..d0536b5a4e01 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -487,6 +487,30 @@ tcp_dma_copybreak - INTEGER and CONFIG_NET_DMA is enabled. Default: 4096 +tcp_thin_linear_timeouts - BOOLEAN + Enable dynamic triggering of linear timeouts for thin streams. + If set, a check is performed upon retransmission by timeout to + determine if the stream is thin (less than 4 packets in flight). + As long as the stream is found to be thin, up to 6 linear + timeouts may be performed before exponential backoff mode is + initiated. This improves retransmission latency for + non-aggressive thin streams, often found to be time-dependent. + For more information on thin streams, see + Documentation/networking/tcp-thin.txt + Default: 0 + +tcp_thin_dupack - BOOLEAN + Enable dynamic triggering of retransmissions after one dupACK + for thin streams. If set, a check is performed upon reception + of a dupACK to determine if the stream is thin (less than 4 + packets in flight). As long as the stream is found to be thin, + data is retransmitted on the first received dupACK. This + improves retransmission latency for non-aggressive thin + streams, often found to be time-dependent. + For more information on thin streams, see + Documentation/networking/tcp-thin.txt + Default: 0 + UDP variables: udp_mem - vector of 3 INTEGERs: min, pressure, max @@ -564,6 +588,37 @@ ip_local_port_range - 2 INTEGERS (i.e. by default) range 1024-4999 is enough to issue up to 2000 connections per second to systems supporting timestamps. +ip_local_reserved_ports - list of comma separated ranges + Specify the ports which are reserved for known third-party + applications. These ports will not be used by automatic port + assignments (e.g. when calling connect() or bind() with port + number 0). Explicit port allocation behavior is unchanged. + + The format used for both input and output is a comma separated + list of ranges (e.g. "1,2-4,10-10" for ports 1, 2, 3, 4 and + 10). Writing to the file will clear all previously reserved + ports and update the current list with the one given in the + input. + + Note that ip_local_port_range and ip_local_reserved_ports + settings are independent and both are considered by the kernel + when determining which ports are available for automatic port + assignments. + + You can reserve ports which are not in the current + ip_local_port_range, e.g.: + + $ cat /proc/sys/net/ipv4/ip_local_port_range + 32000 61000 + $ cat /proc/sys/net/ipv4/ip_local_reserved_ports + 8080,9148 + + although this is redundant. However such a setting is useful + if later the port range is changed to a value that will + include the reserved ports. + + Default: Empty + ip_nonlocal_bind - BOOLEAN If set, allows processes to bind() to non-local IP addresses, which can be quite useful - but may break some applications. @@ -692,6 +747,25 @@ proxy_arp - BOOLEAN conf/{all,interface}/proxy_arp is set to TRUE, it will be disabled otherwise +proxy_arp_pvlan - BOOLEAN + Private VLAN proxy arp. + Basically allow proxy arp replies back to the same interface + (from which the ARP request/solicitation was received). + + This is done to support (ethernet) switch features, like RFC + 3069, where the individual ports are NOT allowed to + communicate with each other, but they are allowed to talk to + the upstream router. As described in RFC 3069, it is possible + to allow these hosts to communicate through the upstream + router by proxy_arp'ing. Don't need to be used together with + proxy_arp. + + This technology is known by different names: + In RFC 3069 it is called VLAN Aggregation. + Cisco and Allied Telesyn call it Private VLAN. + Hewlett-Packard call it Source-Port filtering or port-isolation. + Ericsson call it MAC-Forced Forwarding (RFC Draft). + shared_media - BOOLEAN Send(router) or accept(host) RFC1620 shared media redirects. Overrides ip_secure_redirects. @@ -833,9 +907,18 @@ arp_notify - BOOLEAN or hardware address changes. arp_accept - BOOLEAN - Define behavior when gratuitous arp replies are received: - 0 - drop gratuitous arp frames - 1 - accept gratuitous arp frames + Define behavior for gratuitous ARP frames who's IP is not + already present in the ARP table: + 0 - don't create new entries in the ARP table + 1 - create new entries in the ARP table + + Both replies and requests type gratuitous arp will trigger the + ARP table to be updated, if this setting is on. + + If the ARP table already contains the IP address of the + gratuitous arp frame, the arp table will be updated regardless + if this setting is on or off. + app_solicit - INTEGER The maximum number of probes to send to the user space ARP daemon @@ -1074,10 +1157,10 @@ regen_max_retry - INTEGER Default: 5 max_addresses - INTEGER - Number of maximum addresses per interface. 0 disables limitation. - It is recommended not set too large value (or 0) because it would - be too easy way to crash kernel to allow to create too much of - autoconfigured addresses. + Maximum number of autoconfigured addresses per interface. Setting + to zero disables the limitation. It is not recommended to set this + value too large (or to zero) because it would be an easy way to + crash the kernel by allowing too many addresses to be created. Default: 16 disable_ipv6 - BOOLEAN diff --git a/Documentation/networking/ixgbevf.txt b/Documentation/networking/ixgbevf.txt new file mode 100755 index 000000000000..19015de6725f --- /dev/null +++ b/Documentation/networking/ixgbevf.txt @@ -0,0 +1,90 @@ +Linux* Base Driver for Intel(R) Network Connection +================================================== + +November 24, 2009 + +Contents +======== + +- In This Release +- Identifying Your Adapter +- Known Issues/Troubleshooting +- Support + +In This Release +=============== + +This file describes the ixgbevf Linux* Base Driver for Intel Network +Connection. + +The ixgbevf driver supports 82599-based virtual function devices that can only +be activated on kernels with CONFIG_PCI_IOV enabled. + +The ixgbevf driver supports virtual functions generated by the ixgbe driver +with a max_vfs value of 1 or greater. + +The guest OS loading the ixgbevf driver must support MSI-X interrupts. + +VLANs: There is a limit of a total of 32 shared VLANs to 1 or more VFs. + +Identifying Your Adapter +======================== + +For more information on how to identify your adapter, go to the Adapter & +Driver ID Guide at: + + http://support.intel.com/support/network/sb/CS-008441.htm + +Known Issues/Troubleshooting +============================ + + Unloading Physical Function (PF) Driver Causes System Reboots When VM is + Running and VF is Loaded on the VM + ------------------------------------------------------------------------ + Do not unload the PF driver (ixgbe) while VFs are assigned to guests. + +Support +======= + +For general information, go to the Intel support website at: + + http://support.intel.com + +or the Intel Wired Networking project hosted by Sourceforge at: + + http://sourceforge.net/projects/e1000 + +If an issue is identified with the released source code on the supported +kernel with a supported adapter, email the specific information related +to the issue to e1000-devel@lists.sf.net + +License +======= + +Intel 10 Gigabit Linux driver. +Copyright(c) 1999 - 2009 Intel Corporation. + +This program is free software; you can redistribute it and/or modify it +under the terms and conditions of the GNU General Public License, +version 2, as published by the Free Software Foundation. + +This program is distributed in the hope it will be useful, but WITHOUT +ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for +more details. + +You should have received a copy of the GNU General Public License along with +this program; if not, write to the Free Software Foundation, Inc., +51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + +The full GNU General Public License is included in this distribution in +the file called "COPYING". + +Trademarks +========== + +Intel, Itanium, and Pentium are trademarks or registered trademarks of +Intel Corporation or its subsidiaries in the United States and other +countries. + +* Other names and brands may be claimed as the property of others. diff --git a/Documentation/networking/l2tp.txt b/Documentation/networking/l2tp.txt index 63214b280e00..e7bf3979facb 100644 --- a/Documentation/networking/l2tp.txt +++ b/Documentation/networking/l2tp.txt @@ -1,44 +1,95 @@ -This brief document describes how to use the kernel's PPPoL2TP driver -to provide L2TP functionality. L2TP is a protocol that tunnels one or -more PPP sessions over a UDP tunnel. It is commonly used for VPNs +This document describes how to use the kernel's L2TP drivers to +provide L2TP functionality. L2TP is a protocol that tunnels one or +more sessions over an IP tunnel. It is commonly used for VPNs (L2TP/IPSec) and by ISPs to tunnel subscriber PPP sessions over an IP -network infrastructure. +network infrastructure. With L2TPv3, it is also useful as a Layer-2 +tunneling infrastructure. + +Features +======== + +L2TPv2 (PPP over L2TP (UDP tunnels)). +L2TPv3 ethernet pseudowires. +L2TPv3 PPP pseudowires. +L2TPv3 IP encapsulation. +Netlink sockets for L2TPv3 configuration management. + +History +======= + +The original pppol2tp driver was introduced in 2.6.23 and provided +L2TPv2 functionality (rfc2661). L2TPv2 is used to tunnel one or more PPP +sessions over a UDP tunnel. + +L2TPv3 (rfc3931) changes the protocol to allow different frame types +to be passed over an L2TP tunnel by moving the PPP-specific parts of +the protocol out of the core L2TP packet headers. Each frame type is +known as a pseudowire type. Ethernet, PPP, HDLC, Frame Relay and ATM +pseudowires for L2TP are defined in separate RFC standards. Another +change for L2TPv3 is that it can be carried directly over IP with no +UDP header (UDP is optional). It is also possible to create static +unmanaged L2TPv3 tunnels manually without a control protocol +(userspace daemon) to manage them. + +To support L2TPv3, the original pppol2tp driver was split up to +separate the L2TP and PPP functionality. Existing L2TPv2 userspace +apps should be unaffected as the original pppol2tp sockets API is +retained. L2TPv3, however, uses netlink to manage L2TPv3 tunnels and +sessions. Design ====== -The PPPoL2TP driver, drivers/net/pppol2tp.c, provides a mechanism by -which PPP frames carried through an L2TP session are passed through -the kernel's PPP subsystem. The standard PPP daemon, pppd, handles all -PPP interaction with the peer. PPP network interfaces are created for -each local PPP endpoint. - -The L2TP protocol http://www.faqs.org/rfcs/rfc2661.html defines L2TP -control and data frames. L2TP control frames carry messages between -L2TP clients/servers and are used to setup / teardown tunnels and -sessions. An L2TP client or server is implemented in userspace and -will use a regular UDP socket per tunnel. L2TP data frames carry PPP -frames, which may be PPP control or PPP data. The kernel's PPP +The L2TP protocol separates control and data frames. The L2TP kernel +drivers handle only L2TP data frames; control frames are always +handled by userspace. L2TP control frames carry messages between L2TP +clients/servers and are used to setup / teardown tunnels and +sessions. An L2TP client or server is implemented in userspace. + +Each L2TP tunnel is implemented using a UDP or L2TPIP socket; L2TPIP +provides L2TPv3 IP encapsulation (no UDP) and is implemented using a +new l2tpip socket family. The tunnel socket is typically created by +userspace, though for unmanaged L2TPv3 tunnels, the socket can also be +created by the kernel. Each L2TP session (pseudowire) gets a network +interface instance. In the case of PPP, these interfaces are created +indirectly by pppd using a pppol2tp socket. In the case of ethernet, +the netdevice is created upon a netlink request to create an L2TPv3 +ethernet pseudowire. + +For PPP, the PPPoL2TP driver, net/l2tp/l2tp_ppp.c, provides a +mechanism by which PPP frames carried through an L2TP session are +passed through the kernel's PPP subsystem. The standard PPP daemon, +pppd, handles all PPP interaction with the peer. PPP network +interfaces are created for each local PPP endpoint. The kernel's PPP subsystem arranges for PPP control frames to be delivered to pppd, while data frames are forwarded as usual. +For ethernet, the L2TPETH driver, net/l2tp/l2tp_eth.c, implements a +netdevice driver, managing virtual ethernet devices, one per +pseudowire. These interfaces can be managed using standard Linux tools +such as "ip" and "ifconfig". If only IP frames are passed over the +tunnel, the interface can be given an IP addresses of itself and its +peer. If non-IP frames are to be passed over the tunnel, the interface +can be added to a bridge using brctl. All L2TP datapath protocol +functions are handled by the L2TP core driver. + Each tunnel and session within a tunnel is assigned a unique tunnel_id and session_id. These ids are carried in the L2TP header of every -control and data packet. The pppol2tp driver uses them to lookup -internal tunnel and/or session contexts. Zero tunnel / session ids are -treated specially - zero ids are never assigned to tunnels or sessions -in the network. In the driver, the tunnel context keeps a pointer to -the tunnel UDP socket. The session context keeps a pointer to the -PPPoL2TP socket, as well as other data that lets the driver interface -to the kernel PPP subsystem. - -Note that the pppol2tp kernel driver handles only L2TP data frames; -L2TP control frames are simply passed up to userspace in the UDP -tunnel socket. The kernel handles all datapath aspects of the -protocol, including data packet resequencing (if enabled). - -There are a number of requirements on the userspace L2TP daemon in -order to use the pppol2tp driver. +control and data packet. (Actually, in L2TPv3, the tunnel_id isn't +present in data frames - it is inferred from the IP connection on +which the packet was received.) The L2TP driver uses the ids to lookup +internal tunnel and/or session contexts to determine how to handle the +packet. Zero tunnel / session ids are treated specially - zero ids are +never assigned to tunnels or sessions in the network. In the driver, +the tunnel context keeps a reference to the tunnel UDP or L2TPIP +socket. The session context holds data that lets the driver interface +to the kernel's network frame type subsystems, i.e. PPP, ethernet. + +Userspace Programming +===================== + +For L2TPv2, there are a number of requirements on the userspace L2TP +daemon in order to use the pppol2tp driver. 1. Use a UDP socket per tunnel. @@ -86,6 +137,35 @@ In addition to the standard PPP ioctls, a PPPIOCGL2TPSTATS is provided to retrieve tunnel and session statistics from the kernel using the PPPoX socket of the appropriate tunnel or session. +For L2TPv3, userspace must use the netlink API defined in +include/linux/l2tp.h to manage tunnel and session contexts. The +general procedure to create a new L2TP tunnel with one session is:- + +1. Open a GENL socket using L2TP_GENL_NAME for configuring the kernel + using netlink. + +2. Create a UDP or L2TPIP socket for the tunnel. + +3. Create a new L2TP tunnel using a L2TP_CMD_TUNNEL_CREATE + request. Set attributes according to desired tunnel parameters, + referencing the UDP or L2TPIP socket created in the previous step. + +4. Create a new L2TP session in the tunnel using a + L2TP_CMD_SESSION_CREATE request. + +The tunnel and all of its sessions are closed when the tunnel socket +is closed. The netlink API may also be used to delete sessions and +tunnels. Configuration and status info may be set or read using netlink. + +The L2TP driver also supports static (unmanaged) L2TPv3 tunnels. These +are where there is no L2TP control message exchange with the peer to +setup the tunnel; the tunnel is configured manually at each end of the +tunnel. There is no need for an L2TP userspace application in this +case -- the tunnel socket is created by the kernel and configured +using parameters sent in the L2TP_CMD_TUNNEL_CREATE netlink +request. The "ip" utility of iproute2 has commands for managing static +L2TPv3 tunnels; do "ip l2tp help" for more information. + Debugging ========= @@ -102,6 +182,69 @@ PPPOL2TP_MSG_CONTROL userspace - kernel interface PPPOL2TP_MSG_SEQ sequence numbers handling PPPOL2TP_MSG_DATA data packets +If enabled, files under a l2tp debugfs directory can be used to dump +kernel state about L2TP tunnels and sessions. To access it, the +debugfs filesystem must first be mounted. + +# mount -t debugfs debugfs /debug + +Files under the l2tp directory can then be accessed. + +# cat /debug/l2tp/tunnels + +The debugfs files should not be used by applications to obtain L2TP +state information because the file format is subject to change. It is +implemented to provide extra debug information to help diagnose +problems.) Users should use the netlink API. + +/proc/net/pppol2tp is also provided for backwards compaibility with +the original pppol2tp driver. It lists information about L2TPv2 +tunnels and sessions only. Its use is discouraged. + +Unmanaged L2TPv3 Tunnels +======================== + +Some commercial L2TP products support unmanaged L2TPv3 ethernet +tunnels, where there is no L2TP control protocol; tunnels are +configured at each side manually. New commands are available in +iproute2's ip utility to support this. + +To create an L2TPv3 ethernet pseudowire between local host 192.168.1.1 +and peer 192.168.1.2, using IP addresses 10.5.1.1 and 10.5.1.2 for the +tunnel endpoints:- + +# modprobe l2tp_eth +# modprobe l2tp_netlink + +# ip l2tp add tunnel tunnel_id 1 peer_tunnel_id 1 udp_sport 5000 \ + udp_dport 5000 encap udp local 192.168.1.1 remote 192.168.1.2 +# ip l2tp add session tunnel_id 1 session_id 1 peer_session_id 1 +# ifconfig -a +# ip addr add 10.5.1.2/32 peer 10.5.1.1/32 dev l2tpeth0 +# ifconfig l2tpeth0 up + +Choose IP addresses to be the address of a local IP interface and that +of the remote system. The IP addresses of the l2tpeth0 interface can be +anything suitable. + +Repeat the above at the peer, with ports, tunnel/session ids and IP +addresses reversed. The tunnel and session IDs can be any non-zero +32-bit number, but the values must be reversed at the peer. + +Host 1 Host2 +udp_sport=5000 udp_sport=5001 +udp_dport=5001 udp_dport=5000 +tunnel_id=42 tunnel_id=45 +peer_tunnel_id=45 peer_tunnel_id=42 +session_id=128 session_id=5196755 +peer_session_id=5196755 peer_session_id=128 + +When done at both ends of the tunnel, it should be possible to send +data over the network. e.g. + +# ping 10.5.1.1 + + Sample Userspace Code ===================== @@ -158,12 +301,48 @@ Sample Userspace Code } return 0; +Internal Implementation +======================= + +The driver keeps a struct l2tp_tunnel context per L2TP tunnel and a +struct l2tp_session context for each session. The l2tp_tunnel is +always associated with a UDP or L2TP/IP socket and keeps a list of +sessions in the tunnel. The l2tp_session context keeps kernel state +about the session. It has private data which is used for data specific +to the session type. With L2TPv2, the session always carried PPP +traffic. With L2TPv3, the session can also carry ethernet frames +(ethernet pseudowire) or other data types such as ATM, HDLC or Frame +Relay. + +When a tunnel is first opened, the reference count on the socket is +increased using sock_hold(). This ensures that the kernel socket +cannot be removed while L2TP's data structures reference it. + +Some L2TP sessions also have a socket (PPP pseudowires) while others +do not (ethernet pseudowires). We can't use the socket reference count +as the reference count for session contexts. The L2TP implementation +therefore has its own internal reference counts on the session +contexts. + +To Do +===== + +Add L2TP tunnel switching support. This would route tunneled traffic +from one L2TP tunnel into another. Specified in +http://tools.ietf.org/html/draft-ietf-l2tpext-tunnel-switching-08 + +Add L2TPv3 VLAN pseudowire support. + +Add L2TPv3 IP pseudowire support. + +Add L2TPv3 ATM pseudowire support. + Miscellaneous -============ +============= -The PPPoL2TP driver was developed as part of the OpenL2TP project by +The L2TP drivers were developed as part of the OpenL2TP project by Katalix Systems Ltd. OpenL2TP is a full-featured L2TP client / server, designed from the ground up to have the L2TP datapath in the kernel. The project also implemented the pppol2tp plugin for pppd which allows pppd to use the kernel driver. Details can be found at -http://openl2tp.sourceforge.net. +http://www.openl2tp.org. diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt index a22fd85e3796..98f71a5cef00 100644 --- a/Documentation/networking/packet_mmap.txt +++ b/Documentation/networking/packet_mmap.txt @@ -2,7 +2,7 @@ + ABSTRACT -------------------------------------------------------------------------------- -This file documents the CONFIG_PACKET_MMAP option available with the PACKET +This file documents the mmap() facility available with the PACKET socket interface on 2.4 and 2.6 kernels. This type of sockets is used for capture network traffic with utilities like tcpdump or any other that needs raw access to network interface. @@ -44,7 +44,7 @@ enabled. For transmission, check the MTU (Maximum Transmission Unit) used and supported by devices of your network. -------------------------------------------------------------------------------- -+ How to use CONFIG_PACKET_MMAP to improve capture process ++ How to use mmap() to improve capture process -------------------------------------------------------------------------------- From the user standpoint, you should use the higher level libpcap library, which @@ -64,7 +64,7 @@ the low level details or want to improve libpcap by including PACKET_MMAP support. -------------------------------------------------------------------------------- -+ How to use CONFIG_PACKET_MMAP directly to improve capture process ++ How to use mmap() directly to improve capture process -------------------------------------------------------------------------------- From the system calls stand point, the use of PACKET_MMAP involves @@ -100,12 +100,12 @@ by the kernel. The destruction of the socket and all associated resources is done by a simple call to close(fd). -Next I will describe PACKET_MMAP settings and it's constraints, +Next I will describe PACKET_MMAP settings and its constraints, also the mapping of the circular buffer in the user process and the use of this buffer. -------------------------------------------------------------------------------- -+ How to use CONFIG_PACKET_MMAP directly to improve transmission process ++ How to use mmap() directly to improve transmission process -------------------------------------------------------------------------------- Transmission process is similar to capture as shown below. @@ -432,7 +432,7 @@ TP_STATUS_LOSING : indicates there were packet drops from last time the PACKET_STATISTICS option. TP_STATUS_CSUMNOTREADY: currently it's used for outgoing IP packets which - it's checksum will be done in hardware. So while + its checksum will be done in hardware. So while reading the packet we should not try to check the checksum. diff --git a/Documentation/networking/regulatory.txt b/Documentation/networking/regulatory.txt index ee31369e9e5b..9551622d0a7b 100644 --- a/Documentation/networking/regulatory.txt +++ b/Documentation/networking/regulatory.txt @@ -188,3 +188,27 @@ Then in some part of your code after your wiphy has been registered: &mydriver_jp_regdom.reg_rules[i], sizeof(struct ieee80211_reg_rule)); regulatory_struct_hint(rd); + +Statically compiled regulatory database +--------------------------------------- + +In most situations the userland solution using CRDA as described +above is the preferred solution. However in some cases a set of +rules built into the kernel itself may be desirable. To account +for this situation, a configuration option has been provided +(i.e. CONFIG_CFG80211_INTERNAL_REGDB). With this option enabled, +the wireless database information contained in net/wireless/db.txt is +used to generate a data structure encoded in net/wireless/regdb.c. +That option also enables code in net/wireless/reg.c which queries +the data in regdb.c as an alternative to using CRDA. + +The file net/wireless/db.txt should be kept up-to-date with the db.txt +file available in the git repository here: + + git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-regdb.git + +Again, most users in most situations should be using the CRDA package +provided with their distribution, and in most other situations users +should be building and using CRDA on their own rather than using +this option. If you are not absolutely sure that you should be using +CONFIG_CFG80211_INTERNAL_REGDB then _DO_NOT_USE_IT_. diff --git a/Documentation/networking/skfp.txt b/Documentation/networking/skfp.txt index abfddf81e34a..203ec66c9fb4 100644 --- a/Documentation/networking/skfp.txt +++ b/Documentation/networking/skfp.txt @@ -68,7 +68,7 @@ Compaq adapters (not tested): ======================= From v2.01 on, the driver is integrated in the linux kernel sources. -Therefor, the installation is the same as for any other adapter +Therefore, the installation is the same as for any other adapter supported by the kernel. Refer to the manual of your distribution about the installation of network adapters. diff --git a/Documentation/networking/stmmac.txt b/Documentation/networking/stmmac.txt new file mode 100644 index 000000000000..7ee770b5ef5f --- /dev/null +++ b/Documentation/networking/stmmac.txt @@ -0,0 +1,143 @@ + STMicroelectronics 10/100/1000 Synopsys Ethernet driver + +Copyright (C) 2007-2010 STMicroelectronics Ltd +Author: Giuseppe Cavallaro <peppe.cavallaro@st.com> + +This is the driver for the MAC 10/100/1000 on-chip Ethernet controllers +(Synopsys IP blocks); it has been fully tested on STLinux platforms. + +Currently this network device driver is for all STM embedded MAC/GMAC +(7xxx SoCs). + +DWC Ether MAC 10/100/1000 Universal version 3.41a and DWC Ether MAC 10/100 +Universal version 4.0 have been used for developing the first code +implementation. + +Please, for more information also visit: www.stlinux.com + +1) Kernel Configuration +The kernel configuration option is STMMAC_ETH: + Device Drivers ---> Network device support ---> Ethernet (1000 Mbit) ---> + STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH) + +2) Driver parameters list: + debug: message level (0: no output, 16: all); + phyaddr: to manually provide the physical address to the PHY device; + dma_rxsize: DMA rx ring size; + dma_txsize: DMA tx ring size; + buf_sz: DMA buffer size; + tc: control the HW FIFO threshold; + tx_coe: Enable/Disable Tx Checksum Offload engine; + watchdog: transmit timeout (in milliseconds); + flow_ctrl: Flow control ability [on/off]; + pause: Flow Control Pause Time; + tmrate: timer period (only if timer optimisation is configured). + +3) Command line options +Driver parameters can be also passed in command line by using: + stmmaceth=dma_rxsize:128,dma_txsize:512 + +4) Driver information and notes + +4.1) Transmit process +The xmit method is invoked when the kernel needs to transmit a packet; it sets +the descriptors in the ring and informs the DMA engine that there is a packet +ready to be transmitted. +Once the controller has finished transmitting the packet, an interrupt is +triggered; So the driver will be able to release the socket buffers. +By default, the driver sets the NETIF_F_SG bit in the features field of the +net_device structure enabling the scatter/gather feature. + +4.2) Receive process +When one or more packets are received, an interrupt happens. The interrupts +are not queued so the driver has to scan all the descriptors in the ring during +the receive process. +This is based on NAPI so the interrupt handler signals only if there is work to be +done, and it exits. +Then the poll method will be scheduled at some future point. +The incoming packets are stored, by the DMA, in a list of pre-allocated socket +buffers in order to avoid the memcpy (Zero-copy). + +4.3) Timer-Driver Interrupt +Instead of having the device that asynchronously notifies the frame receptions, the +driver configures a timer to generate an interrupt at regular intervals. +Based on the granularity of the timer, the frames that are received by the device +will experience different levels of latency. Some NICs have dedicated timer +device to perform this task. STMMAC can use either the RTC device or the TMU +channel 2 on STLinux platforms. +The timers frequency can be passed to the driver as parameter; when change it, +take care of both hardware capability and network stability/performance impact. +Several performance tests on STM platforms showed this optimisation allows to spare +the CPU while having the maximum throughput. + +4.4) WOL +Wake up on Lan feature through Magic Frame is only supported for the GMAC +core. + +4.5) DMA descriptors +Driver handles both normal and enhanced descriptors. The latter has been only +tested on DWC Ether MAC 10/100/1000 Universal version 3.41a. + +4.6) Ethtool support +Ethtool is supported. Driver statistics and internal errors can be taken using: +ethtool -S ethX command. It is possible to dump registers etc. + +4.7) Jumbo and Segmentation Offloading +Jumbo frames are supported and tested for the GMAC. +The GSO has been also added but it's performed in software. +LRO is not supported. + +4.8) Physical +The driver is compatible with PAL to work with PHY and GPHY devices. + +4.9) Platform information +Several information came from the platform; please refer to the +driver's Header file in include/linux directory. + +struct plat_stmmacenet_data { + int bus_id; + int pbl; + int has_gmac; + void (*fix_mac_speed)(void *priv, unsigned int speed); + void (*bus_setup)(unsigned long ioaddr); +#ifdef CONFIG_STM_DRIVERS + struct stm_pad_config *pad_config; +#endif + void *bsp_priv; +}; + +Where: +- pbl (Programmable Burst Length) is maximum number of + beats to be transferred in one DMA transaction. + GMAC also enables the 4xPBL by default. +- fix_mac_speed and bus_setup are used to configure internal target + registers (on STM platforms); +- has_gmac: GMAC core is on board (get it at run-time in the next step); +- bus_id: bus identifier. + +struct plat_stmmacphy_data { + int bus_id; + int phy_addr; + unsigned int phy_mask; + int interface; + int (*phy_reset)(void *priv); + void *priv; +}; + +Where: +- bus_id: bus identifier; +- phy_addr: physical address used for the attached phy device; + set it to -1 to get it at run-time; +- interface: physical MII interface mode; +- phy_reset: hook to reset HW function. + +TODO: +- Continue to make the driver more generic and suitable for other Synopsys + Ethernet controllers used on other architectures (i.e. ARM). +- 10G controllers are not supported. +- MAC uses Normal descriptors and GMAC uses enhanced ones. + This is a limit that should be reviewed. MAC could want to + use the enhanced structure. +- Checksumming: Rx/Tx csum is done in HW in case of GMAC only. +- Review the timer optimisation code to use an embedded device that seems to be + available in new chip generations. diff --git a/Documentation/networking/tcp-thin.txt b/Documentation/networking/tcp-thin.txt new file mode 100644 index 000000000000..151e229980f1 --- /dev/null +++ b/Documentation/networking/tcp-thin.txt @@ -0,0 +1,47 @@ +Thin-streams and TCP +==================== +A wide range of Internet-based services that use reliable transport +protocols display what we call thin-stream properties. This means +that the application sends data with such a low rate that the +retransmission mechanisms of the transport protocol are not fully +effective. In time-dependent scenarios (like online games, control +systems, stock trading etc.) where the user experience depends +on the data delivery latency, packet loss can be devastating for +the service quality. Extreme latencies are caused by TCP's +dependency on the arrival of new data from the application to trigger +retransmissions effectively through fast retransmit instead of +waiting for long timeouts. + +After analysing a large number of time-dependent interactive +applications, we have seen that they often produce thin streams +and also stay with this traffic pattern throughout its entire +lifespan. The combination of time-dependency and the fact that the +streams provoke high latencies when using TCP is unfortunate. + +In order to reduce application-layer latency when packets are lost, +a set of mechanisms has been made, which address these latency issues +for thin streams. In short, if the kernel detects a thin stream, +the retransmission mechanisms are modified in the following manner: + +1) If the stream is thin, fast retransmit on the first dupACK. +2) If the stream is thin, do not apply exponential backoff. + +These enhancements are applied only if the stream is detected as +thin. This is accomplished by defining a threshold for the number +of packets in flight. If there are less than 4 packets in flight, +fast retransmissions can not be triggered, and the stream is prone +to experience high retransmission latencies. + +Since these mechanisms are targeted at time-dependent applications, +they must be specifically activated by the application using the +TCP_THIN_LINEAR_TIMEOUTS and TCP_THIN_DUPACK IOCTLS or the +tcp_thin_linear_timeouts and tcp_thin_dupack sysctls. Both +modifications are turned off by default. + +References +========== +More information on the modifications, as well as a wide range of +experimental data can be found here: +"Improving latency for interactive, thin-stream applications over +reliable transport" +http://simula.no/research/nd/publications/Simula.nd.477/simula_pdf_file diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 0e58b4539176..e8c8f4f06c67 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -41,11 +41,12 @@ SOF_TIMESTAMPING_SOFTWARE: return system time stamp generated in SOF_TIMESTAMPING_TX/RX determine how time stamps are generated. SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the following control message: - struct scm_timestamping { - struct timespec systime; - struct timespec hwtimetrans; - struct timespec hwtimeraw; - }; + +struct scm_timestamping { + struct timespec systime; + struct timespec hwtimetrans; + struct timespec hwtimeraw; +}; recvmsg() can be used to get this control message for regular incoming packets. For send time stamps the outgoing packet is looped back to @@ -87,12 +88,13 @@ by the network device and will be empty without that support. SIOCSHWTSTAMP: Hardware time stamping must also be initialized for each device driver -that is expected to do hardware time stamping. The parameter is: +that is expected to do hardware time stamping. The parameter is defined in +/include/linux/net_tstamp.h as: struct hwtstamp_config { - int flags; /* no flags defined right now, must be zero */ - int tx_type; /* HWTSTAMP_TX_* */ - int rx_filter; /* HWTSTAMP_FILTER_* */ + int flags; /* no flags defined right now, must be zero */ + int tx_type; /* HWTSTAMP_TX_* */ + int rx_filter; /* HWTSTAMP_FILTER_* */ }; Desired behavior is passed into the kernel and to a specific device by @@ -139,42 +141,56 @@ enum { /* time stamp any incoming packet */ HWTSTAMP_FILTER_ALL, - /* return value: time stamp all packets requested plus some others */ - HWTSTAMP_FILTER_SOME, + /* return value: time stamp all packets requested plus some others */ + HWTSTAMP_FILTER_SOME, /* PTP v1, UDP, any kind of event packet */ HWTSTAMP_FILTER_PTP_V1_L4_EVENT, - ... + /* for the complete list of values, please check + * the include file /include/linux/net_tstamp.h + */ }; DEVICE IMPLEMENTATION A driver which supports hardware time stamping must support the -SIOCSHWTSTAMP ioctl. Time stamps for received packets must be stored -in the skb with skb_hwtstamp_set(). +SIOCSHWTSTAMP ioctl and update the supplied struct hwtstamp_config with +the actual values as described in the section on SIOCSHWTSTAMP. + +Time stamps for received packets must be stored in the skb. To get a pointer +to the shared time stamp structure of the skb call skb_hwtstamps(). Then +set the time stamps in the structure: + +struct skb_shared_hwtstamps { + /* hardware time stamp transformed into duration + * since arbitrary point in time + */ + ktime_t hwtstamp; + ktime_t syststamp; /* hwtstamp transformed to system time base */ +}; Time stamps for outgoing packets are to be generated as follows: -- In hard_start_xmit(), check if skb_hwtstamp_check_tx_hardware() - returns non-zero. If yes, then the driver is expected - to do hardware time stamping. +- In hard_start_xmit(), check if skb_tx(skb)->hardware is set no-zero. + If yes, then the driver is expected to do hardware time stamping. - If this is possible for the skb and requested, then declare - that the driver is doing the time stamping by calling - skb_hwtstamp_tx_in_progress(). A driver not supporting - hardware time stamping doesn't do that. A driver must never - touch sk_buff::tstamp! It is used to store how time stamping - for an outgoing packets is to be done. + that the driver is doing the time stamping by setting the field + skb_tx(skb)->in_progress non-zero. You might want to keep a pointer + to the associated skb for the next step and not free the skb. A driver + not supporting hardware time stamping doesn't do that. A driver must + never touch sk_buff::tstamp! It is used to store software generated + time stamps by the network subsystem. - As soon as the driver has sent the packet and/or obtained a hardware time stamp for it, it passes the time stamp back by calling skb_hwtstamp_tx() with the original skb, the raw - hardware time stamp and a handle to the device (necessary - to convert the hardware time stamp to system time). If obtaining - the hardware time stamp somehow fails, then the driver should - not fall back to software time stamping. The rationale is that - this would occur at a later time in the processing pipeline - than other software time stamping and therefore could lead - to unexpected deltas between time stamps. -- If the driver did not call skb_hwtstamp_tx_in_progress(), then + hardware time stamp. skb_hwtstamp_tx() clones the original skb and + adds the timestamps, therefore the original skb has to be freed now. + If obtaining the hardware time stamp somehow fails, then the driver + should not fall back to software time stamping. The rationale is that + this would occur at a later time in the processing pipeline than other + software time stamping and therefore could lead to unexpected deltas + between time stamps. +- If the driver did not call set skb_tx(skb)->in_progress, then dev_hard_start_xmit() checks whether software time stamping is wanted as fallback and potentially generates the time stamp. diff --git a/Documentation/networking/timestamping/Makefile b/Documentation/networking/timestamping/Makefile index 2a1489fdc036..e79973443e9f 100644 --- a/Documentation/networking/timestamping/Makefile +++ b/Documentation/networking/timestamping/Makefile @@ -1,6 +1,13 @@ -CPPFLAGS = -I../../../include +# kbuild trick to avoid linker error. Can be omitted if a module is built. +obj- := dummy.o -timestamping: timestamping.c +# List of programs to build +hostprogs-y := timestamping + +# Tell kbuild to always build the programs +always := $(hostprogs-y) + +HOSTCFLAGS_timestamping.o += -I$(objtree)/usr/include clean: rm -f timestamping diff --git a/Documentation/networking/timestamping/timestamping.c b/Documentation/networking/timestamping/timestamping.c index a7936fe8444a..8ba82bfe6a33 100644 --- a/Documentation/networking/timestamping/timestamping.c +++ b/Documentation/networking/timestamping/timestamping.c @@ -41,9 +41,9 @@ #include <arpa/inet.h> #include <net/if.h> -#include "asm/types.h" -#include "linux/net_tstamp.h" -#include "linux/errqueue.h" +#include <asm/types.h> +#include <linux/net_tstamp.h> +#include <linux/errqueue.h> #ifndef SO_TIMESTAMPING # define SO_TIMESTAMPING 37 @@ -164,7 +164,7 @@ static void printpacket(struct msghdr *msg, int res, gettimeofday(&now, 0); - printf("%ld.%06ld: received %s data, %d bytes from %s, %d bytes control messages\n", + printf("%ld.%06ld: received %s data, %d bytes from %s, %zu bytes control messages\n", (long)now.tv_sec, (long)now.tv_usec, (recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular", res, @@ -173,7 +173,7 @@ static void printpacket(struct msghdr *msg, int res, for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { - printf(" cmsg len %d: ", cmsg->cmsg_len); + printf(" cmsg len %zu: ", cmsg->cmsg_len); switch (cmsg->cmsg_level) { case SOL_SOCKET: printf("SOL_SOCKET "); @@ -370,7 +370,7 @@ int main(int argc, char **argv) } sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); - if (socket < 0) + if (sock < 0) bail("socket"); memset(&device, 0, sizeof(device)); diff --git a/Documentation/networking/x25-iface.txt b/Documentation/networking/x25-iface.txt index 975cc87ebdd1..78f662ee0622 100644 --- a/Documentation/networking/x25-iface.txt +++ b/Documentation/networking/x25-iface.txt @@ -20,23 +20,23 @@ the rest of the skbuff, if any more information does exist. Packet Layer to Device Driver ----------------------------- -First Byte = 0x00 +First Byte = 0x00 (X25_IFACE_DATA) This indicates that the rest of the skbuff contains data to be transmitted over the LAPB link. The LAPB link should already exist before any data is passed down. -First Byte = 0x01 +First Byte = 0x01 (X25_IFACE_CONNECT) Establish the LAPB link. If the link is already established then the connect confirmation message should be returned as soon as possible. -First Byte = 0x02 +First Byte = 0x02 (X25_IFACE_DISCONNECT) Terminate the LAPB link. If it is already disconnected then the disconnect confirmation message should be returned as soon as possible. -First Byte = 0x03 +First Byte = 0x03 (X25_IFACE_PARAMS) LAPB parameters. To be defined. @@ -44,22 +44,22 @@ LAPB parameters. To be defined. Device Driver to Packet Layer ----------------------------- -First Byte = 0x00 +First Byte = 0x00 (X25_IFACE_DATA) This indicates that the rest of the skbuff contains data that has been received over the LAPB link. -First Byte = 0x01 +First Byte = 0x01 (X25_IFACE_CONNECT) LAPB link has been established. The same message is used for both a LAPB link connect_confirmation and a connect_indication. -First Byte = 0x02 +First Byte = 0x02 (X25_IFACE_DISCONNECT) LAPB link has been terminated. This same message is used for both a LAPB link disconnect_confirmation and a disconnect_indication. -First Byte = 0x03 +First Byte = 0x03 (X25_IFACE_PARAMS) LAPB parameters. To be defined. |
