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-rw-r--r--Documentation/networking/00-INDEX4
-rw-r--r--Documentation/networking/bonding.txt204
-rw-r--r--Documentation/networking/can.txt629
-rw-r--r--Documentation/networking/dccp.txt39
-rw-r--r--Documentation/networking/ip-sysctl.txt27
-rw-r--r--Documentation/networking/shaper.txt48
-rw-r--r--Documentation/networking/udplite.txt2
-rw-r--r--Documentation/networking/xfrm_proc.txt70
8 files changed, 904 insertions, 119 deletions
diff --git a/Documentation/networking/00-INDEX b/Documentation/networking/00-INDEX
index 563e442f2d42..02e56d447a8f 100644
--- a/Documentation/networking/00-INDEX
+++ b/Documentation/networking/00-INDEX
@@ -24,6 +24,8 @@ baycom.txt
24 - info on the driver for Baycom style amateur radio modems 24 - info on the driver for Baycom style amateur radio modems
25bridge.txt 25bridge.txt
26 - where to get user space programs for ethernet bridging with Linux. 26 - where to get user space programs for ethernet bridging with Linux.
27can.txt
28 - documentation on CAN protocol family.
27cops.txt 29cops.txt
28 - info on the COPS LocalTalk Linux driver 30 - info on the COPS LocalTalk Linux driver
29cs89x0.txt 31cs89x0.txt
@@ -82,8 +84,6 @@ policy-routing.txt
82 - IP policy-based routing 84 - IP policy-based routing
83ray_cs.txt 85ray_cs.txt
84 - Raylink Wireless LAN card driver info. 86 - Raylink Wireless LAN card driver info.
85shaper.txt
86 - info on the module that can shape/limit transmitted traffic.
87sk98lin.txt 87sk98lin.txt
88 - Marvell Yukon Chipset / SysKonnect SK-98xx compliant Gigabit 88 - Marvell Yukon Chipset / SysKonnect SK-98xx compliant Gigabit
89 Ethernet Adapter family driver info 89 Ethernet Adapter family driver info
diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt
index 6cc30e0d5795..a0cda062bc33 100644
--- a/Documentation/networking/bonding.txt
+++ b/Documentation/networking/bonding.txt
@@ -1,7 +1,7 @@
1 1
2 Linux Ethernet Bonding Driver HOWTO 2 Linux Ethernet Bonding Driver HOWTO
3 3
4 Latest update: 24 April 2006 4 Latest update: 12 November 2007
5 5
6Initial release : Thomas Davis <tadavis at lbl.gov> 6Initial release : Thomas Davis <tadavis at lbl.gov>
7Corrections, HA extensions : 2000/10/03-15 : 7Corrections, HA extensions : 2000/10/03-15 :
@@ -166,12 +166,17 @@ to use ifenslave.
1662. Bonding Driver Options 1662. Bonding Driver Options
167========================= 167=========================
168 168
169 Options for the bonding driver are supplied as parameters to 169 Options for the bonding driver are supplied as parameters to the
170the bonding module at load time. They may be given as command line 170bonding module at load time, or are specified via sysfs.
171arguments to the insmod or modprobe command, but are usually specified 171
172in either the /etc/modules.conf or /etc/modprobe.conf configuration 172 Module options may be given as command line arguments to the
173file, or in a distro-specific configuration file (some of which are 173insmod or modprobe command, but are usually specified in either the
174detailed in the next section). 174/etc/modules.conf or /etc/modprobe.conf configuration file, or in a
175distro-specific configuration file (some of which are detailed in the next
176section).
177
178 Details on bonding support for sysfs is provided in the
179"Configuring Bonding Manually via Sysfs" section, below.
175 180
176 The available bonding driver parameters are listed below. If a 181 The available bonding driver parameters are listed below. If a
177parameter is not specified the default value is used. When initially 182parameter is not specified the default value is used. When initially
@@ -812,11 +817,13 @@ the system /etc/modules.conf or /etc/modprobe.conf configuration file.
8123.2 Configuration with Initscripts Support 8173.2 Configuration with Initscripts Support
813------------------------------------------ 818------------------------------------------
814 819
815 This section applies to distros using a version of initscripts 820 This section applies to distros using a recent version of
816with bonding support, for example, Red Hat Linux 9 or Red Hat 821initscripts with bonding support, for example, Red Hat Enterprise Linux
817Enterprise Linux version 3 or 4. On these systems, the network 822version 3 or later, Fedora, etc. On these systems, the network
818initialization scripts have some knowledge of bonding, and can be 823initialization scripts have knowledge of bonding, and can be configured to
819configured to control bonding devices. 824control bonding devices. Note that older versions of the initscripts
825package have lower levels of support for bonding; this will be noted where
826applicable.
820 827
821 These distros will not automatically load the network adapter 828 These distros will not automatically load the network adapter
822driver unless the ethX device is configured with an IP address. 829driver unless the ethX device is configured with an IP address.
@@ -864,11 +871,31 @@ USERCTL=no
864 Be sure to change the networking specific lines (IPADDR, 871 Be sure to change the networking specific lines (IPADDR,
865NETMASK, NETWORK and BROADCAST) to match your network configuration. 872NETMASK, NETWORK and BROADCAST) to match your network configuration.
866 873
867 Finally, it is necessary to edit /etc/modules.conf (or 874 For later versions of initscripts, such as that found with Fedora
868/etc/modprobe.conf, depending upon your distro) to load the bonding 8757 and Red Hat Enterprise Linux version 5 (or later), it is possible, and,
869module with your desired options when the bond0 interface is brought 876indeed, preferable, to specify the bonding options in the ifcfg-bond0
870up. The following lines in /etc/modules.conf (or modprobe.conf) will 877file, e.g. a line of the format:
871load the bonding module, and select its options: 878
879BONDING_OPTS="mode=active-backup arp_interval=60 arp_ip_target=+192.168.1.254"
880
881 will configure the bond with the specified options. The options
882specified in BONDING_OPTS are identical to the bonding module parameters
883except for the arp_ip_target field. Each target should be included as a
884separate option and should be preceded by a '+' to indicate it should be
885added to the list of queried targets, e.g.,
886
887 arp_ip_target=+192.168.1.1 arp_ip_target=+192.168.1.2
888
889 is the proper syntax to specify multiple targets. When specifying
890options via BONDING_OPTS, it is not necessary to edit /etc/modules.conf or
891/etc/modprobe.conf.
892
893 For older versions of initscripts that do not support
894BONDING_OPTS, it is necessary to edit /etc/modules.conf (or
895/etc/modprobe.conf, depending upon your distro) to load the bonding module
896with your desired options when the bond0 interface is brought up. The
897following lines in /etc/modules.conf (or modprobe.conf) will load the
898bonding module, and select its options:
872 899
873alias bond0 bonding 900alias bond0 bonding
874options bond0 mode=balance-alb miimon=100 901options bond0 mode=balance-alb miimon=100
@@ -883,9 +910,10 @@ up and running.
8833.2.1 Using DHCP with Initscripts 9103.2.1 Using DHCP with Initscripts
884--------------------------------- 911---------------------------------
885 912
886 Recent versions of initscripts (the version supplied with 913 Recent versions of initscripts (the versions supplied with Fedora
887Fedora Core 3 and Red Hat Enterprise Linux 4 is reported to work) do 914Core 3 and Red Hat Enterprise Linux 4, or later versions, are reported to
888have support for assigning IP information to bonding devices via DHCP. 915work) have support for assigning IP information to bonding devices via
916DHCP.
889 917
890 To configure bonding for DHCP, configure it as described 918 To configure bonding for DHCP, configure it as described
891above, except replace the line "BOOTPROTO=none" with "BOOTPROTO=dhcp" 919above, except replace the line "BOOTPROTO=none" with "BOOTPROTO=dhcp"
@@ -895,18 +923,14 @@ is case sensitive.
8953.2.2 Configuring Multiple Bonds with Initscripts 9233.2.2 Configuring Multiple Bonds with Initscripts
896------------------------------------------------- 924-------------------------------------------------
897 925
898 At this writing, the initscripts package does not directly 926 Initscripts packages that are included with Fedora 7 and Red Hat
899support loading the bonding driver multiple times, so the process for 927Enterprise Linux 5 support multiple bonding interfaces by simply
900doing so is the same as described in the "Configuring Multiple Bonds 928specifying the appropriate BONDING_OPTS= in ifcfg-bondX where X is the
901Manually" section, below. 929number of the bond. This support requires sysfs support in the kernel,
902 930and a bonding driver of version 3.0.0 or later. Other configurations may
903 NOTE: It has been observed that some Red Hat supplied kernels 931not support this method for specifying multiple bonding interfaces; for
904are apparently unable to rename modules at load time (the "-o bond1" 932those instances, see the "Configuring Multiple Bonds Manually" section,
905part). Attempts to pass that option to modprobe will produce an 933below.
906"Operation not permitted" error. This has been reported on some
907Fedora Core kernels, and has been seen on RHEL 4 as well. On kernels
908exhibiting this problem, it will be impossible to configure multiple
909bonds with differing parameters.
910 934
9113.3 Configuring Bonding Manually with Ifenslave 9353.3 Configuring Bonding Manually with Ifenslave
912----------------------------------------------- 936-----------------------------------------------
@@ -977,15 +1001,58 @@ initialization scripts lack support for configuring multiple bonds.
977options, you may wish to use the "max_bonds" module parameter, 1001options, you may wish to use the "max_bonds" module parameter,
978documented above. 1002documented above.
979 1003
980 To create multiple bonding devices with differing options, it 1004 To create multiple bonding devices with differing options, it is
981is necessary to use bonding parameters exported by sysfs, documented 1005preferrable to use bonding parameters exported by sysfs, documented in the
982in the section below. 1006section below.
1007
1008 For versions of bonding without sysfs support, the only means to
1009provide multiple instances of bonding with differing options is to load
1010the bonding driver multiple times. Note that current versions of the
1011sysconfig network initialization scripts handle this automatically; if
1012your distro uses these scripts, no special action is needed. See the
1013section Configuring Bonding Devices, above, if you're not sure about your
1014network initialization scripts.
1015
1016 To load multiple instances of the module, it is necessary to
1017specify a different name for each instance (the module loading system
1018requires that every loaded module, even multiple instances of the same
1019module, have a unique name). This is accomplished by supplying multiple
1020sets of bonding options in /etc/modprobe.conf, for example:
1021
1022alias bond0 bonding
1023options bond0 -o bond0 mode=balance-rr miimon=100
1024
1025alias bond1 bonding
1026options bond1 -o bond1 mode=balance-alb miimon=50
1027
1028 will load the bonding module two times. The first instance is
1029named "bond0" and creates the bond0 device in balance-rr mode with an
1030miimon of 100. The second instance is named "bond1" and creates the
1031bond1 device in balance-alb mode with an miimon of 50.
1032
1033 In some circumstances (typically with older distributions),
1034the above does not work, and the second bonding instance never sees
1035its options. In that case, the second options line can be substituted
1036as follows:
1037
1038install bond1 /sbin/modprobe --ignore-install bonding -o bond1 \
1039 mode=balance-alb miimon=50
983 1040
1041 This may be repeated any number of times, specifying a new and
1042unique name in place of bond1 for each subsequent instance.
1043
1044 It has been observed that some Red Hat supplied kernels are unable
1045to rename modules at load time (the "-o bond1" part). Attempts to pass
1046that option to modprobe will produce an "Operation not permitted" error.
1047This has been reported on some Fedora Core kernels, and has been seen on
1048RHEL 4 as well. On kernels exhibiting this problem, it will be impossible
1049to configure multiple bonds with differing parameters (as they are older
1050kernels, and also lack sysfs support).
984 1051
9853.4 Configuring Bonding Manually via Sysfs 10523.4 Configuring Bonding Manually via Sysfs
986------------------------------------------ 1053------------------------------------------
987 1054
988 Starting with version 3.0, Channel Bonding may be configured 1055 Starting with version 3.0.0, Channel Bonding may be configured
989via the sysfs interface. This interface allows dynamic configuration 1056via the sysfs interface. This interface allows dynamic configuration
990of all bonds in the system without unloading the module. It also 1057of all bonds in the system without unloading the module. It also
991allows for adding and removing bonds at runtime. Ifenslave is no 1058allows for adding and removing bonds at runtime. Ifenslave is no
@@ -1030,9 +1097,6 @@ To enslave interface eth0 to bond bond0:
1030To free slave eth0 from bond bond0: 1097To free slave eth0 from bond bond0:
1031# echo -eth0 > /sys/class/net/bond0/bonding/slaves 1098# echo -eth0 > /sys/class/net/bond0/bonding/slaves
1032 1099
1033 NOTE: The bond must be up before slaves can be added. All
1034slaves are freed when the interface is brought down.
1035
1036 When an interface is enslaved to a bond, symlinks between the 1100 When an interface is enslaved to a bond, symlinks between the
1037two are created in the sysfs filesystem. In this case, you would get 1101two are created in the sysfs filesystem. In this case, you would get
1038/sys/class/net/bond0/slave_eth0 pointing to /sys/class/net/eth0, and 1102/sys/class/net/bond0/slave_eth0 pointing to /sys/class/net/eth0, and
@@ -1622,6 +1686,15 @@ one for each switch in the network). This will insure that,
1622regardless of which switch is active, the ARP monitor has a suitable 1686regardless of which switch is active, the ARP monitor has a suitable
1623target to query. 1687target to query.
1624 1688
1689 Note, also, that of late many switches now support a functionality
1690generally referred to as "trunk failover." This is a feature of the
1691switch that causes the link state of a particular switch port to be set
1692down (or up) when the state of another switch port goes down (or up).
1693It's purpose is to propogate link failures from logically "exterior" ports
1694to the logically "interior" ports that bonding is able to monitor via
1695miimon. Availability and configuration for trunk failover varies by
1696switch, but this can be a viable alternative to the ARP monitor when using
1697suitable switches.
1625 1698
162612. Configuring Bonding for Maximum Throughput 169912. Configuring Bonding for Maximum Throughput
1627============================================== 1700==============================================
@@ -1709,7 +1782,7 @@ balance-rr: This mode is the only mode that will permit a single
1709 interfaces. It is therefore the only mode that will allow a 1782 interfaces. It is therefore the only mode that will allow a
1710 single TCP/IP stream to utilize more than one interface's 1783 single TCP/IP stream to utilize more than one interface's
1711 worth of throughput. This comes at a cost, however: the 1784 worth of throughput. This comes at a cost, however: the
1712 striping often results in peer systems receiving packets out 1785 striping generally results in peer systems receiving packets out
1713 of order, causing TCP/IP's congestion control system to kick 1786 of order, causing TCP/IP's congestion control system to kick
1714 in, often by retransmitting segments. 1787 in, often by retransmitting segments.
1715 1788
@@ -1721,22 +1794,20 @@ balance-rr: This mode is the only mode that will permit a single
1721 interface's worth of throughput, even after adjusting 1794 interface's worth of throughput, even after adjusting
1722 tcp_reordering. 1795 tcp_reordering.
1723 1796
1724 Note that this out of order delivery occurs when both the 1797 Note that the fraction of packets that will be delivered out of
1725 sending and receiving systems are utilizing a multiple 1798 order is highly variable, and is unlikely to be zero. The level
1726 interface bond. Consider a configuration in which a 1799 of reordering depends upon a variety of factors, including the
1727 balance-rr bond feeds into a single higher capacity network 1800 networking interfaces, the switch, and the topology of the
1728 channel (e.g., multiple 100Mb/sec ethernets feeding a single 1801 configuration. Speaking in general terms, higher speed network
1729 gigabit ethernet via an etherchannel capable switch). In this 1802 cards produce more reordering (due to factors such as packet
1730 configuration, traffic sent from the multiple 100Mb devices to 1803 coalescing), and a "many to many" topology will reorder at a
1731 a destination connected to the gigabit device will not see 1804 higher rate than a "many slow to one fast" configuration.
1732 packets out of order. However, traffic sent from the gigabit 1805
1733 device to the multiple 100Mb devices may or may not see 1806 Many switches do not support any modes that stripe traffic
1734 traffic out of order, depending upon the balance policy of the 1807 (instead choosing a port based upon IP or MAC level addresses);
1735 switch. Many switches do not support any modes that stripe 1808 for those devices, traffic for a particular connection flowing
1736 traffic (instead choosing a port based upon IP or MAC level 1809 through the switch to a balance-rr bond will not utilize greater
1737 addresses); for those devices, traffic flowing from the 1810 than one interface's worth of bandwidth.
1738 gigabit device to the many 100Mb devices will only utilize one
1739 interface.
1740 1811
1741 If you are utilizing protocols other than TCP/IP, UDP for 1812 If you are utilizing protocols other than TCP/IP, UDP for
1742 example, and your application can tolerate out of order 1813 example, and your application can tolerate out of order
@@ -1936,6 +2007,10 @@ Failover may be delayed via the downdelay bonding module option.
193613.2 Duplicated Incoming Packets 200713.2 Duplicated Incoming Packets
1937-------------------------------- 2008--------------------------------
1938 2009
2010 NOTE: Starting with version 3.0.2, the bonding driver has logic to
2011suppress duplicate packets, which should largely eliminate this problem.
2012The following description is kept for reference.
2013
1939 It is not uncommon to observe a short burst of duplicated 2014 It is not uncommon to observe a short burst of duplicated
1940traffic when the bonding device is first used, or after it has been 2015traffic when the bonding device is first used, or after it has been
1941idle for some period of time. This is most easily observed by issuing 2016idle for some period of time. This is most easily observed by issuing
@@ -2096,6 +2171,9 @@ The new driver was designed to be SMP safe from the start.
2096EtherExpress PRO/100 and a 3com 3c905b, for example). For most modes, 2171EtherExpress PRO/100 and a 3com 3c905b, for example). For most modes,
2097devices need not be of the same speed. 2172devices need not be of the same speed.
2098 2173
2174 Starting with version 3.2.1, bonding also supports Infiniband
2175slaves in active-backup mode.
2176
20993. How many bonding devices can I have? 21773. How many bonding devices can I have?
2100 2178
2101 There is no limit. 2179 There is no limit.
@@ -2154,11 +2232,15 @@ switches currently available support 802.3ad.
2154 2232
21558. Where does a bonding device get its MAC address from? 22338. Where does a bonding device get its MAC address from?
2156 2234
2157 If not explicitly configured (with ifconfig or ip link), the 2235 When using slave devices that have fixed MAC addresses, or when
2158MAC address of the bonding device is taken from its first slave 2236the fail_over_mac option is enabled, the bonding device's MAC address is
2159device. This MAC address is then passed to all following slaves and 2237the MAC address of the active slave.
2160remains persistent (even if the first slave is removed) until the 2238
2161bonding device is brought down or reconfigured. 2239 For other configurations, if not explicitly configured (with
2240ifconfig or ip link), the MAC address of the bonding device is taken from
2241its first slave device. This MAC address is then passed to all following
2242slaves and remains persistent (even if the first slave is removed) until
2243the bonding device is brought down or reconfigured.
2162 2244
2163 If you wish to change the MAC address, you can set it with 2245 If you wish to change the MAC address, you can set it with
2164ifconfig or ip link: 2246ifconfig or ip link:
diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt
new file mode 100644
index 000000000000..f1b2de170929
--- /dev/null
+++ b/Documentation/networking/can.txt
@@ -0,0 +1,629 @@
1============================================================================
2
3can.txt
4
5Readme file for the Controller Area Network Protocol Family (aka Socket CAN)
6
7This file contains
8
9 1 Overview / What is Socket CAN
10
11 2 Motivation / Why using the socket API
12
13 3 Socket CAN concept
14 3.1 receive lists
15 3.2 local loopback of sent frames
16 3.3 network security issues (capabilities)
17 3.4 network problem notifications
18
19 4 How to use Socket CAN
20 4.1 RAW protocol sockets with can_filters (SOCK_RAW)
21 4.1.1 RAW socket option CAN_RAW_FILTER
22 4.1.2 RAW socket option CAN_RAW_ERR_FILTER
23 4.1.3 RAW socket option CAN_RAW_LOOPBACK
24 4.1.4 RAW socket option CAN_RAW_RECV_OWN_MSGS
25 4.2 Broadcast Manager protocol sockets (SOCK_DGRAM)
26 4.3 connected transport protocols (SOCK_SEQPACKET)
27 4.4 unconnected transport protocols (SOCK_DGRAM)
28
29 5 Socket CAN core module
30 5.1 can.ko module params
31 5.2 procfs content
32 5.3 writing own CAN protocol modules
33
34 6 CAN network drivers
35 6.1 general settings
36 6.2 local loopback of sent frames
37 6.3 CAN controller hardware filters
38 6.4 currently supported CAN hardware
39 6.5 todo
40
41 7 Credits
42
43============================================================================
44
451. Overview / What is Socket CAN
46--------------------------------
47
48The socketcan package is an implementation of CAN protocols
49(Controller Area Network) for Linux. CAN is a networking technology
50which has widespread use in automation, embedded devices, and
51automotive fields. While there have been other CAN implementations
52for Linux based on character devices, Socket CAN uses the Berkeley
53socket API, the Linux network stack and implements the CAN device
54drivers as network interfaces. The CAN socket API has been designed
55as similar as possible to the TCP/IP protocols to allow programmers,
56familiar with network programming, to easily learn how to use CAN
57sockets.
58
592. Motivation / Why using the socket API
60----------------------------------------
61
62There have been CAN implementations for Linux before Socket CAN so the
63question arises, why we have started another project. Most existing
64implementations come as a device driver for some CAN hardware, they
65are based on character devices and provide comparatively little
66functionality. Usually, there is only a hardware-specific device
67driver which provides a character device interface to send and
68receive raw CAN frames, directly to/from the controller hardware.
69Queueing of frames and higher-level transport protocols like ISO-TP
70have to be implemented in user space applications. Also, most
71character-device implementations support only one single process to
72open the device at a time, similar to a serial interface. Exchanging
73the CAN controller requires employment of another device driver and
74often the need for adaption of large parts of the application to the
75new driver's API.
76
77Socket CAN was designed to overcome all of these limitations. A new
78protocol family has been implemented which provides a socket interface
79to user space applications and which builds upon the Linux network
80layer, so to use all of the provided queueing functionality. A device
81driver for CAN controller hardware registers itself with the Linux
82network layer as a network device, so that CAN frames from the
83controller can be passed up to the network layer and on to the CAN
84protocol family module and also vice-versa. Also, the protocol family
85module provides an API for transport protocol modules to register, so
86that any number of transport protocols can be loaded or unloaded
87dynamically. In fact, the can core module alone does not provide any
88protocol and cannot be used without loading at least one additional
89protocol module. Multiple sockets can be opened at the same time,
90on different or the same protocol module and they can listen/send
91frames on different or the same CAN IDs. Several sockets listening on
92the same interface for frames with the same CAN ID are all passed the
93same received matching CAN frames. An application wishing to
94communicate using a specific transport protocol, e.g. ISO-TP, just
95selects that protocol when opening the socket, and then can read and
96write application data byte streams, without having to deal with
97CAN-IDs, frames, etc.
98
99Similar functionality visible from user-space could be provided by a
100character device, too, but this would lead to a technically inelegant
101solution for a couple of reasons:
102
103* Intricate usage. Instead of passing a protocol argument to
104 socket(2) and using bind(2) to select a CAN interface and CAN ID, an
105 application would have to do all these operations using ioctl(2)s.
106
107* Code duplication. A character device cannot make use of the Linux
108 network queueing code, so all that code would have to be duplicated
109 for CAN networking.
110
111* Abstraction. In most existing character-device implementations, the
112 hardware-specific device driver for a CAN controller directly
113 provides the character device for the application to work with.
114 This is at least very unusual in Unix systems for both, char and
115 block devices. For example you don't have a character device for a
116 certain UART of a serial interface, a certain sound chip in your
117 computer, a SCSI or IDE controller providing access to your hard
118 disk or tape streamer device. Instead, you have abstraction layers
119 which provide a unified character or block device interface to the
120 application on the one hand, and a interface for hardware-specific
121 device drivers on the other hand. These abstractions are provided
122 by subsystems like the tty layer, the audio subsystem or the SCSI
123 and IDE subsystems for the devices mentioned above.
124
125 The easiest way to implement a CAN device driver is as a character
126 device without such a (complete) abstraction layer, as is done by most
127 existing drivers. The right way, however, would be to add such a
128 layer with all the functionality like registering for certain CAN
129 IDs, supporting several open file descriptors and (de)multiplexing
130 CAN frames between them, (sophisticated) queueing of CAN frames, and
131 providing an API for device drivers to register with. However, then
132 it would be no more difficult, or may be even easier, to use the
133 networking framework provided by the Linux kernel, and this is what
134 Socket CAN does.
135
136 The use of the networking framework of the Linux kernel is just the
137 natural and most appropriate way to implement CAN for Linux.
138
1393. Socket CAN concept
140---------------------
141
142 As described in chapter 2 it is the main goal of Socket CAN to
143 provide a socket interface to user space applications which builds
144 upon the Linux network layer. In contrast to the commonly known
145 TCP/IP and ethernet networking, the CAN bus is a broadcast-only(!)
146 medium that has no MAC-layer addressing like ethernet. The CAN-identifier
147 (can_id) is used for arbitration on the CAN-bus. Therefore the CAN-IDs
148 have to be chosen uniquely on the bus. When designing a CAN-ECU
149 network the CAN-IDs are mapped to be sent by a specific ECU.
150 For this reason a CAN-ID can be treated best as a kind of source address.
151
152 3.1 receive lists
153
154 The network transparent access of multiple applications leads to the
155 problem that different applications may be interested in the same
156 CAN-IDs from the same CAN network interface. The Socket CAN core
157 module - which implements the protocol family CAN - provides several
158 high efficient receive lists for this reason. If e.g. a user space
159 application opens a CAN RAW socket, the raw protocol module itself
160 requests the (range of) CAN-IDs from the Socket CAN core that are
161 requested by the user. The subscription and unsubscription of
162 CAN-IDs can be done for specific CAN interfaces or for all(!) known
163 CAN interfaces with the can_rx_(un)register() functions provided to
164 CAN protocol modules by the SocketCAN core (see chapter 5).
165 To optimize the CPU usage at runtime the receive lists are split up
166 into several specific lists per device that match the requested
167 filter complexity for a given use-case.
168
169 3.2 local loopback of sent frames
170
171 As known from other networking concepts the data exchanging
172 applications may run on the same or different nodes without any
173 change (except for the according addressing information):
174
175 ___ ___ ___ _______ ___
176 | _ | | _ | | _ | | _ _ | | _ |
177 ||A|| ||B|| ||C|| ||A| |B|| ||C||
178 |___| |___| |___| |_______| |___|
179 | | | | |
180 -----------------(1)- CAN bus -(2)---------------
181
182 To ensure that application A receives the same information in the
183 example (2) as it would receive in example (1) there is need for
184 some kind of local loopback of the sent CAN frames on the appropriate
185 node.
186
187 The Linux network devices (by default) just can handle the
188 transmission and reception of media dependent frames. Due to the
189 arbritration on the CAN bus the transmission of a low prio CAN-ID
190 may be delayed by the reception of a high prio CAN frame. To
191 reflect the correct* traffic on the node the loopback of the sent
192 data has to be performed right after a successful transmission. If
193 the CAN network interface is not capable of performing the loopback for
194 some reason the SocketCAN core can do this task as a fallback solution.
195 See chapter 6.2 for details (recommended).
196
197 The loopback functionality is enabled by default to reflect standard
198 networking behaviour for CAN applications. Due to some requests from
199 the RT-SocketCAN group the loopback optionally may be disabled for each
200 separate socket. See sockopts from the CAN RAW sockets in chapter 4.1.
201
202 * = you really like to have this when you're running analyser tools
203 like 'candump' or 'cansniffer' on the (same) node.
204
205 3.3 network security issues (capabilities)
206
207 The Controller Area Network is a local field bus transmitting only
208 broadcast messages without any routing and security concepts.
209 In the majority of cases the user application has to deal with
210 raw CAN frames. Therefore it might be reasonable NOT to restrict
211 the CAN access only to the user root, as known from other networks.
212 Since the currently implemented CAN_RAW and CAN_BCM sockets can only
213 send and receive frames to/from CAN interfaces it does not affect
214 security of others networks to allow all users to access the CAN.
215 To enable non-root users to access CAN_RAW and CAN_BCM protocol
216 sockets the Kconfig options CAN_RAW_USER and/or CAN_BCM_USER may be
217 selected at kernel compile time.
218
219 3.4 network problem notifications
220
221 The use of the CAN bus may lead to several problems on the physical
222 and media access control layer. Detecting and logging of these lower
223 layer problems is a vital requirement for CAN users to identify
224 hardware issues on the physical transceiver layer as well as
225 arbitration problems and error frames caused by the different
226 ECUs. The occurrence of detected errors are important for diagnosis
227 and have to be logged together with the exact timestamp. For this
228 reason the CAN interface driver can generate so called Error Frames
229 that can optionally be passed to the user application in the same
230 way as other CAN frames. Whenever an error on the physical layer
231 or the MAC layer is detected (e.g. by the CAN controller) the driver
232 creates an appropriate error frame. Error frames can be requested by
233 the user application using the common CAN filter mechanisms. Inside
234 this filter definition the (interested) type of errors may be
235 selected. The reception of error frames is disabled by default.
236
2374. How to use Socket CAN
238------------------------
239
240 Like TCP/IP, you first need to open a socket for communicating over a
241 CAN network. Since Socket CAN implements a new protocol family, you
242 need to pass PF_CAN as the first argument to the socket(2) system
243 call. Currently, there are two CAN protocols to choose from, the raw
244 socket protocol and the broadcast manager (BCM). So to open a socket,
245 you would write
246
247 s = socket(PF_CAN, SOCK_RAW, CAN_RAW);
248
249 and
250
251 s = socket(PF_CAN, SOCK_DGRAM, CAN_BCM);
252
253 respectively. After the successful creation of the socket, you would
254 normally use the bind(2) system call to bind the socket to a CAN
255 interface (which is different from TCP/IP due to different addressing
256 - see chapter 3). After binding (CAN_RAW) or connecting (CAN_BCM)
257 the socket, you can read(2) and write(2) from/to the socket or use
258 send(2), sendto(2), sendmsg(2) and the recv* counterpart operations
259 on the socket as usual. There are also CAN specific socket options
260 described below.
261
262 The basic CAN frame structure and the sockaddr structure are defined
263 in include/linux/can.h:
264
265 struct can_frame {
266 canid_t can_id; /* 32 bit CAN_ID + EFF/RTR/ERR flags */
267 __u8 can_dlc; /* data length code: 0 .. 8 */
268 __u8 data[8] __attribute__((aligned(8)));
269 };
270
271 The alignment of the (linear) payload data[] to a 64bit boundary
272 allows the user to define own structs and unions to easily access the
273 CAN payload. There is no given byteorder on the CAN bus by
274 default. A read(2) system call on a CAN_RAW socket transfers a
275 struct can_frame to the user space.
276
277 The sockaddr_can structure has an interface index like the
278 PF_PACKET socket, that also binds to a specific interface:
279
280 struct sockaddr_can {
281 sa_family_t can_family;
282 int can_ifindex;
283 union {
284 struct { canid_t rx_id, tx_id; } tp16;
285 struct { canid_t rx_id, tx_id; } tp20;
286 struct { canid_t rx_id, tx_id; } mcnet;
287 struct { canid_t rx_id, tx_id; } isotp;
288 } can_addr;
289 };
290
291 To determine the interface index an appropriate ioctl() has to
292 be used (example for CAN_RAW sockets without error checking):
293
294 int s;
295 struct sockaddr_can addr;
296 struct ifreq ifr;
297
298 s = socket(PF_CAN, SOCK_RAW, CAN_RAW);
299
300 strcpy(ifr.ifr_name, "can0" );
301 ioctl(s, SIOCGIFINDEX, &ifr);
302
303 addr.can_family = AF_CAN;
304 addr.can_ifindex = ifr.ifr_ifindex;
305
306 bind(s, (struct sockaddr *)&addr, sizeof(addr));
307
308 (..)
309
310 To bind a socket to all(!) CAN interfaces the interface index must
311 be 0 (zero). In this case the socket receives CAN frames from every
312 enabled CAN interface. To determine the originating CAN interface
313 the system call recvfrom(2) may be used instead of read(2). To send
314 on a socket that is bound to 'any' interface sendto(2) is needed to
315 specify the outgoing interface.
316
317 Reading CAN frames from a bound CAN_RAW socket (see above) consists
318 of reading a struct can_frame:
319
320 struct can_frame frame;
321
322 nbytes = read(s, &frame, sizeof(struct can_frame));
323
324 if (nbytes < 0) {
325 perror("can raw socket read");
326 return 1;
327 }
328
329 /* paraniod check ... */
330 if (nbytes < sizeof(struct can_frame)) {
331 fprintf(stderr, "read: incomplete CAN frame\n");
332 return 1;
333 }
334
335 /* do something with the received CAN frame */
336
337 Writing CAN frames can be done similarly, with the write(2) system call:
338
339 nbytes = write(s, &frame, sizeof(struct can_frame));
340
341 When the CAN interface is bound to 'any' existing CAN interface
342 (addr.can_ifindex = 0) it is recommended to use recvfrom(2) if the
343 information about the originating CAN interface is needed:
344
345 struct sockaddr_can addr;
346 struct ifreq ifr;
347 socklen_t len = sizeof(addr);
348 struct can_frame frame;
349
350 nbytes = recvfrom(s, &frame, sizeof(struct can_frame),
351 0, (struct sockaddr*)&addr, &len);
352
353 /* get interface name of the received CAN frame */
354 ifr.ifr_ifindex = addr.can_ifindex;
355 ioctl(s, SIOCGIFNAME, &ifr);
356 printf("Received a CAN frame from interface %s", ifr.ifr_name);
357
358 To write CAN frames on sockets bound to 'any' CAN interface the
359 outgoing interface has to be defined certainly.
360
361 strcpy(ifr.ifr_name, "can0");
362 ioctl(s, SIOCGIFINDEX, &ifr);
363 addr.can_ifindex = ifr.ifr_ifindex;
364 addr.can_family = AF_CAN;
365
366 nbytes = sendto(s, &frame, sizeof(struct can_frame),
367 0, (struct sockaddr*)&addr, sizeof(addr));
368
369 4.1 RAW protocol sockets with can_filters (SOCK_RAW)
370
371 Using CAN_RAW sockets is extensively comparable to the commonly
372 known access to CAN character devices. To meet the new possibilities
373 provided by the multi user SocketCAN approach, some reasonable
374 defaults are set at RAW socket binding time:
375
376 - The filters are set to exactly one filter receiving everything
377 - The socket only receives valid data frames (=> no error frames)
378 - The loopback of sent CAN frames is enabled (see chapter 3.2)
379 - The socket does not receive its own sent frames (in loopback mode)
380
381 These default settings may be changed before or after binding the socket.
382 To use the referenced definitions of the socket options for CAN_RAW
383 sockets, include <linux/can/raw.h>.
384
385 4.1.1 RAW socket option CAN_RAW_FILTER
386
387 The reception of CAN frames using CAN_RAW sockets can be controlled
388 by defining 0 .. n filters with the CAN_RAW_FILTER socket option.
389
390 The CAN filter structure is defined in include/linux/can.h:
391
392 struct can_filter {
393 canid_t can_id;
394 canid_t can_mask;
395 };
396
397 A filter matches, when
398
399 <received_can_id> & mask == can_id & mask
400
401 which is analogous to known CAN controllers hardware filter semantics.
402 The filter can be inverted in this semantic, when the CAN_INV_FILTER
403 bit is set in can_id element of the can_filter structure. In
404 contrast to CAN controller hardware filters the user may set 0 .. n
405 receive filters for each open socket separately:
406
407 struct can_filter rfilter[2];
408
409 rfilter[0].can_id = 0x123;
410 rfilter[0].can_mask = CAN_SFF_MASK;
411 rfilter[1].can_id = 0x200;
412 rfilter[1].can_mask = 0x700;
413
414 setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, &rfilter, sizeof(rfilter));
415
416 To disable the reception of CAN frames on the selected CAN_RAW socket:
417
418 setsockopt(s, SOL_CAN_RAW, CAN_RAW_FILTER, NULL, 0);
419
420 To set the filters to zero filters is quite obsolete as not read
421 data causes the raw socket to discard the received CAN frames. But
422 having this 'send only' use-case we may remove the receive list in the
423 Kernel to save a little (really a very little!) CPU usage.
424
425 4.1.2 RAW socket option CAN_RAW_ERR_FILTER
426
427 As described in chapter 3.4 the CAN interface driver can generate so
428 called Error Frames that can optionally be passed to the user
429 application in the same way as other CAN frames. The possible
430 errors are divided into different error classes that may be filtered
431 using the appropriate error mask. To register for every possible
432 error condition CAN_ERR_MASK can be used as value for the error mask.
433 The values for the error mask are defined in linux/can/error.h .
434
435 can_err_mask_t err_mask = ( CAN_ERR_TX_TIMEOUT | CAN_ERR_BUSOFF );
436
437 setsockopt(s, SOL_CAN_RAW, CAN_RAW_ERR_FILTER,
438 &err_mask, sizeof(err_mask));
439
440 4.1.3 RAW socket option CAN_RAW_LOOPBACK
441
442 To meet multi user needs the local loopback is enabled by default
443 (see chapter 3.2 for details). But in some embedded use-cases
444 (e.g. when only one application uses the CAN bus) this loopback
445 functionality can be disabled (separately for each socket):
446
447 int loopback = 0; /* 0 = disabled, 1 = enabled (default) */
448
449 setsockopt(s, SOL_CAN_RAW, CAN_RAW_LOOPBACK, &loopback, sizeof(loopback));
450
451 4.1.4 RAW socket option CAN_RAW_RECV_OWN_MSGS
452
453 When the local loopback is enabled, all the sent CAN frames are
454 looped back to the open CAN sockets that registered for the CAN
455 frames' CAN-ID on this given interface to meet the multi user
456 needs. The reception of the CAN frames on the same socket that was
457 sending the CAN frame is assumed to be unwanted and therefore
458 disabled by default. This default behaviour may be changed on
459 demand:
460
461 int recv_own_msgs = 1; /* 0 = disabled (default), 1 = enabled */
462
463 setsockopt(s, SOL_CAN_RAW, CAN_RAW_RECV_OWN_MSGS,
464 &recv_own_msgs, sizeof(recv_own_msgs));
465
466 4.2 Broadcast Manager protocol sockets (SOCK_DGRAM)
467 4.3 connected transport protocols (SOCK_SEQPACKET)
468 4.4 unconnected transport protocols (SOCK_DGRAM)
469
470
4715. Socket CAN core module
472-------------------------
473
474 The Socket CAN core module implements the protocol family
475 PF_CAN. CAN protocol modules are loaded by the core module at
476 runtime. The core module provides an interface for CAN protocol
477 modules to subscribe needed CAN IDs (see chapter 3.1).
478
479 5.1 can.ko module params
480
481 - stats_timer: To calculate the Socket CAN core statistics
482 (e.g. current/maximum frames per second) this 1 second timer is
483 invoked at can.ko module start time by default. This timer can be
484 disabled by using stattimer=0 on the module comandline.
485
486 - debug: (removed since SocketCAN SVN r546)
487
488 5.2 procfs content
489
490 As described in chapter 3.1 the Socket CAN core uses several filter
491 lists to deliver received CAN frames to CAN protocol modules. These
492 receive lists, their filters and the count of filter matches can be
493 checked in the appropriate receive list. All entries contain the
494 device and a protocol module identifier:
495
496 foo@bar:~$ cat /proc/net/can/rcvlist_all
497
498 receive list 'rx_all':
499 (vcan3: no entry)
500 (vcan2: no entry)
501 (vcan1: no entry)
502 device can_id can_mask function userdata matches ident
503 vcan0 000 00000000 f88e6370 f6c6f400 0 raw
504 (any: no entry)
505
506 In this example an application requests any CAN traffic from vcan0.
507
508 rcvlist_all - list for unfiltered entries (no filter operations)
509 rcvlist_eff - list for single extended frame (EFF) entries
510 rcvlist_err - list for error frames masks
511 rcvlist_fil - list for mask/value filters
512 rcvlist_inv - list for mask/value filters (inverse semantic)
513 rcvlist_sff - list for single standard frame (SFF) entries
514
515 Additional procfs files in /proc/net/can
516
517 stats - Socket CAN core statistics (rx/tx frames, match ratios, ...)
518 reset_stats - manual statistic reset
519 version - prints the Socket CAN core version and the ABI version
520
521 5.3 writing own CAN protocol modules
522
523 To implement a new protocol in the protocol family PF_CAN a new
524 protocol has to be defined in include/linux/can.h .
525 The prototypes and definitions to use the Socket CAN core can be
526 accessed by including include/linux/can/core.h .
527 In addition to functions that register the CAN protocol and the
528 CAN device notifier chain there are functions to subscribe CAN
529 frames received by CAN interfaces and to send CAN frames:
530
531 can_rx_register - subscribe CAN frames from a specific interface
532 can_rx_unregister - unsubscribe CAN frames from a specific interface
533 can_send - transmit a CAN frame (optional with local loopback)
534
535 For details see the kerneldoc documentation in net/can/af_can.c or
536 the source code of net/can/raw.c or net/can/bcm.c .
537
5386. CAN network drivers
539----------------------
540
541 Writing a CAN network device driver is much easier than writing a
542 CAN character device driver. Similar to other known network device
543 drivers you mainly have to deal with:
544
545 - TX: Put the CAN frame from the socket buffer to the CAN controller.
546 - RX: Put the CAN frame from the CAN controller to the socket buffer.
547
548 See e.g. at Documentation/networking/netdevices.txt . The differences
549 for writing CAN network device driver are described below:
550
551 6.1 general settings
552
553 dev->type = ARPHRD_CAN; /* the netdevice hardware type */
554 dev->flags = IFF_NOARP; /* CAN has no arp */
555
556 dev->mtu = sizeof(struct can_frame);
557
558 The struct can_frame is the payload of each socket buffer in the
559 protocol family PF_CAN.
560
561 6.2 local loopback of sent frames
562
563 As described in chapter 3.2 the CAN network device driver should
564 support a local loopback functionality similar to the local echo
565 e.g. of tty devices. In this case the driver flag IFF_ECHO has to be
566 set to prevent the PF_CAN core from locally echoing sent frames
567 (aka loopback) as fallback solution:
568
569 dev->flags = (IFF_NOARP | IFF_ECHO);
570
571 6.3 CAN controller hardware filters
572
573 To reduce the interrupt load on deep embedded systems some CAN
574 controllers support the filtering of CAN IDs or ranges of CAN IDs.
575 These hardware filter capabilities vary from controller to
576 controller and have to be identified as not feasible in a multi-user
577 networking approach. The use of the very controller specific
578 hardware filters could make sense in a very dedicated use-case, as a
579 filter on driver level would affect all users in the multi-user
580 system. The high efficient filter sets inside the PF_CAN core allow
581 to set different multiple filters for each socket separately.
582 Therefore the use of hardware filters goes to the category 'handmade
583 tuning on deep embedded systems'. The author is running a MPC603e
584 @133MHz with four SJA1000 CAN controllers from 2002 under heavy bus
585 load without any problems ...
586
587 6.4 currently supported CAN hardware (September 2007)
588
589 On the project website http://developer.berlios.de/projects/socketcan
590 there are different drivers available:
591
592 vcan: Virtual CAN interface driver (if no real hardware is available)
593 sja1000: Philips SJA1000 CAN controller (recommended)
594 i82527: Intel i82527 CAN controller
595 mscan: Motorola/Freescale CAN controller (e.g. inside SOC MPC5200)
596 ccan: CCAN controller core (e.g. inside SOC h7202)
597 slcan: For a bunch of CAN adaptors that are attached via a
598 serial line ASCII protocol (for serial / USB adaptors)
599
600 Additionally the different CAN adaptors (ISA/PCI/PCMCIA/USB/Parport)
601 from PEAK Systemtechnik support the CAN netdevice driver model
602 since Linux driver v6.0: http://www.peak-system.com/linux/index.htm
603
604 Please check the Mailing Lists on the berlios OSS project website.
605
606 6.5 todo (September 2007)
607
608 The configuration interface for CAN network drivers is still an open
609 issue that has not been finalized in the socketcan project. Also the
610 idea of having a library module (candev.ko) that holds functions
611 that are needed by all CAN netdevices is not ready to ship.
612 Your contribution is welcome.
613
6147. Credits
615----------
616
617 Oliver Hartkopp (PF_CAN core, filters, drivers, bcm)
618 Urs Thuermann (PF_CAN core, kernel integration, socket interfaces, raw, vcan)
619 Jan Kizka (RT-SocketCAN core, Socket-API reconciliation)
620 Wolfgang Grandegger (RT-SocketCAN core & drivers, Raw Socket-API reviews)
621 Robert Schwebel (design reviews, PTXdist integration)
622 Marc Kleine-Budde (design reviews, Kernel 2.6 cleanups, drivers)
623 Benedikt Spranger (reviews)
624 Thomas Gleixner (LKML reviews, coding style, posting hints)
625 Andrey Volkov (kernel subtree structure, ioctls, mscan driver)
626 Matthias Brukner (first SJA1000 CAN netdevice implementation Q2/2003)
627 Klaus Hitschler (PEAK driver integration)
628 Uwe Koppe (CAN netdevices with PF_PACKET approach)
629 Michael Schulze (driver layer loopback requirement, RT CAN drivers review)
diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt
index afb66f9a8aff..39131a3c78f8 100644
--- a/Documentation/networking/dccp.txt
+++ b/Documentation/networking/dccp.txt
@@ -14,24 +14,35 @@ Introduction
14============ 14============
15 15
16Datagram Congestion Control Protocol (DCCP) is an unreliable, connection 16Datagram Congestion Control Protocol (DCCP) is an unreliable, connection
17based protocol designed to solve issues present in UDP and TCP particularly 17oriented protocol designed to solve issues present in UDP and TCP, particularly
18for real time and multimedia traffic. 18for real-time and multimedia (streaming) traffic.
19It divides into a base protocol (RFC 4340) and plugable congestion control
20modules called CCIDs. Like plugable TCP congestion control, at least one CCID
21needs to be enabled in order for the protocol to function properly. In the Linux
22implementation, this is the TCP-like CCID2 (RFC 4341). Additional CCIDs, such as
23the TCP-friendly CCID3 (RFC 4342), are optional.
24For a brief introduction to CCIDs and suggestions for choosing a CCID to match
25given applications, see section 10 of RFC 4340.
19 26
20It has a base protocol and pluggable congestion control IDs (CCIDs). 27It has a base protocol and pluggable congestion control IDs (CCIDs).
21 28
22It is at proposed standard RFC status and the homepage for DCCP as a protocol 29DCCP is a Proposed Standard (RFC 2026), and the homepage for DCCP as a protocol
23is at: 30is at http://www.ietf.org/html.charters/dccp-charter.html
24 http://www.read.cs.ucla.edu/dccp/
25 31
26Missing features 32Missing features
27================ 33================
28 34
29The DCCP implementation does not currently have all the features that are in 35The Linux DCCP implementation does not currently support all the features that are
30the RFC. 36specified in RFCs 4340...42.
31 37
32The known bugs are at: 38The known bugs are at:
33 http://linux-net.osdl.org/index.php/TODO#DCCP 39 http://linux-net.osdl.org/index.php/TODO#DCCP
34 40
41For more up-to-date versions of the DCCP implementation, please consider using
42the experimental DCCP test tree; instructions for checking this out are on:
43http://linux-net.osdl.org/index.php/DCCP_Testing#Experimental_DCCP_source_tree
44
45
35Socket options 46Socket options
36============== 47==============
37 48
@@ -46,6 +57,12 @@ can be set before calling bind().
46DCCP_SOCKOPT_GET_CUR_MPS is read-only and retrieves the current maximum packet 57DCCP_SOCKOPT_GET_CUR_MPS is read-only and retrieves the current maximum packet
47size (application payload size) in bytes, see RFC 4340, section 14. 58size (application payload size) in bytes, see RFC 4340, section 14.
48 59
60DCCP_SOCKOPT_SERVER_TIMEWAIT enables the server (listening socket) to hold
61timewait state when closing the connection (RFC 4340, 8.3). The usual case is
62that the closing server sends a CloseReq, whereupon the client holds timewait
63state. When this boolean socket option is on, the server sends a Close instead
64and will enter TIMEWAIT. This option must be set after accept() returns.
65
49DCCP_SOCKOPT_SEND_CSCOV and DCCP_SOCKOPT_RECV_CSCOV are used for setting the 66DCCP_SOCKOPT_SEND_CSCOV and DCCP_SOCKOPT_RECV_CSCOV are used for setting the
50partial checksum coverage (RFC 4340, sec. 9.2). The default is that checksums 67partial checksum coverage (RFC 4340, sec. 9.2). The default is that checksums
51always cover the entire packet and that only fully covered application data is 68always cover the entire packet and that only fully covered application data is
@@ -72,6 +89,8 @@ DCCP_SOCKOPT_CCID_TX_INFO
72 Returns a `struct tfrc_tx_info' in optval; the buffer for optval and 89 Returns a `struct tfrc_tx_info' in optval; the buffer for optval and
73 optlen must be set to at least sizeof(struct tfrc_tx_info). 90 optlen must be set to at least sizeof(struct tfrc_tx_info).
74 91
92On unidirectional connections it is useful to close the unused half-connection
93via shutdown (SHUT_WR or SHUT_RD): this will reduce per-packet processing costs.
75 94
76Sysctl variables 95Sysctl variables
77================ 96================
@@ -123,6 +142,12 @@ sync_ratelimit = 125 ms
123 sequence-invalid packets on the same socket (RFC 4340, 7.5.4). The unit 142 sequence-invalid packets on the same socket (RFC 4340, 7.5.4). The unit
124 of this parameter is milliseconds; a value of 0 disables rate-limiting. 143 of this parameter is milliseconds; a value of 0 disables rate-limiting.
125 144
145IOCTLS
146======
147FIONREAD
148 Works as in udp(7): returns in the `int' argument pointer the size of
149 the next pending datagram in bytes, or 0 when no datagram is pending.
150
126Notes 151Notes
127===== 152=====
128 153
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 6f7872ba1def..17a6e46fbd43 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -446,6 +446,33 @@ tcp_dma_copybreak - INTEGER
446 and CONFIG_NET_DMA is enabled. 446 and CONFIG_NET_DMA is enabled.
447 Default: 4096 447 Default: 4096
448 448
449UDP variables:
450
451udp_mem - vector of 3 INTEGERs: min, pressure, max
452 Number of pages allowed for queueing by all UDP sockets.
453
454 min: Below this number of pages UDP is not bothered about its
455 memory appetite. When amount of memory allocated by UDP exceeds
456 this number, UDP starts to moderate memory usage.
457
458 pressure: This value was introduced to follow format of tcp_mem.
459
460 max: Number of pages allowed for queueing by all UDP sockets.
461
462 Default is calculated at boot time from amount of available memory.
463
464udp_rmem_min - INTEGER
465 Minimal size of receive buffer used by UDP sockets in moderation.
466 Each UDP socket is able to use the size for receiving data, even if
467 total pages of UDP sockets exceed udp_mem pressure. The unit is byte.
468 Default: 4096
469
470udp_wmem_min - INTEGER
471 Minimal size of send buffer used by UDP sockets in moderation.
472 Each UDP socket is able to use the size for sending data, even if
473 total pages of UDP sockets exceed udp_mem pressure. The unit is byte.
474 Default: 4096
475
449CIPSOv4 Variables: 476CIPSOv4 Variables:
450 477
451cipso_cache_enable - BOOLEAN 478cipso_cache_enable - BOOLEAN
diff --git a/Documentation/networking/shaper.txt b/Documentation/networking/shaper.txt
deleted file mode 100644
index 6c4ebb66a906..000000000000
--- a/Documentation/networking/shaper.txt
+++ /dev/null
@@ -1,48 +0,0 @@
1Traffic Shaper For Linux
2
3This is the current BETA release of the traffic shaper for Linux. It works
4within the following limits:
5
6o Minimum shaping speed is currently about 9600 baud (it can only
7shape down to 1 byte per clock tick)
8
9o Maximum is about 256K, it will go above this but get a bit blocky.
10
11o If you ifconfig the master device that a shaper is attached to down
12then your machine will follow.
13
14o The shaper must be a module.
15
16
17Setup:
18
19 A shaper device is configured using the shapeconfig program.
20Typically you will do something like this
21
22shapecfg attach shaper0 eth1
23shapecfg speed shaper0 64000
24ifconfig shaper0 myhost netmask 255.255.255.240 broadcast 1.2.3.4.255 up
25route add -net some.network netmask a.b.c.d dev shaper0
26
27The shaper should have the same IP address as the device it is attached to
28for normal use.
29
30Gotchas:
31
32 The shaper shapes transmitted traffic. It's rather impossible to
33shape received traffic except at the end (or a router) transmitting it.
34
35 Gated/routed/rwhod/mrouted all see the shaper as an additional device
36and will treat it as such unless patched. Note that for mrouted you can run
37mrouted tunnels via a traffic shaper to control bandwidth usage.
38
39 The shaper is device/route based. This makes it very easy to use
40with any setup BUT less flexible. You may need to use iproute2 to set up
41multiple route tables to get the flexibility.
42
43 There is no "borrowing" or "sharing" scheme. This is a simple
44traffic limiter. We implement Van Jacobson and Sally Floyd's CBQ
45architecture into Linux 2.2. This is the preferred solution. Shaper is
46for simple or back compatible setups.
47
48Alan
diff --git a/Documentation/networking/udplite.txt b/Documentation/networking/udplite.txt
index b6409cab075c..3870f280280b 100644
--- a/Documentation/networking/udplite.txt
+++ b/Documentation/networking/udplite.txt
@@ -236,7 +236,7 @@
236 236
237 This displays UDP-Lite statistics variables, whose meaning is as follows. 237 This displays UDP-Lite statistics variables, whose meaning is as follows.
238 238
239 InDatagrams: Total number of received datagrams. 239 InDatagrams: The total number of datagrams delivered to users.
240 240
241 NoPorts: Number of packets received to an unknown port. 241 NoPorts: Number of packets received to an unknown port.
242 These cases are counted separately (not as InErrors). 242 These cases are counted separately (not as InErrors).
diff --git a/Documentation/networking/xfrm_proc.txt b/Documentation/networking/xfrm_proc.txt
new file mode 100644
index 000000000000..53c1a58b02f1
--- /dev/null
+++ b/Documentation/networking/xfrm_proc.txt
@@ -0,0 +1,70 @@
1XFRM proc - /proc/net/xfrm_* files
2==================================
3Masahide NAKAMURA <nakam@linux-ipv6.org>
4
5
6Transformation Statistics
7-------------------------
8xfrm_proc is a statistics shown factor dropped by transformation
9for developer.
10It is a counter designed from current transformation source code
11and defined like linux private MIB.
12
13Inbound statistics
14~~~~~~~~~~~~~~~~~~
15XfrmInError:
16 All errors which is not matched others
17XfrmInBufferError:
18 No buffer is left
19XfrmInHdrError:
20 Header error
21XfrmInNoStates:
22 No state is found
23 i.e. Either inbound SPI, address, or IPsec protocol at SA is wrong
24XfrmInStateProtoError:
25 Transformation protocol specific error
26 e.g. SA key is wrong
27XfrmInStateModeError:
28 Transformation mode specific error
29XfrmInSeqOutOfWindow:
30 Sequence out of window
31XfrmInStateExpired:
32 State is expired
33XfrmInStateMismatch:
34 State has mismatch option
35 e.g. UDP encapsulation type is mismatch
36XfrmInStateInvalid:
37 State is invalid
38XfrmInTmplMismatch:
39 No matching template for states
40 e.g. Inbound SAs are correct but SP rule is wrong
41XfrmInNoPols:
42 No policy is found for states
43 e.g. Inbound SAs are correct but no SP is found
44XfrmInPolBlock:
45 Policy discards
46XfrmInPolError:
47 Policy error
48
49Outbound errors
50~~~~~~~~~~~~~~~
51XfrmOutError:
52 All errors which is not matched others
53XfrmOutBundleGenError:
54 Bundle generation error
55XfrmOutBundleCheckError:
56 Bundle check error
57XfrmOutNoStates:
58 No state is found
59XfrmOutStateProtoError:
60 Transformation protocol specific error
61XfrmOutStateModeError:
62 Transformation mode specific error
63XfrmOutStateExpired:
64 State is expired
65XfrmOutPolBlock:
66 Policy discards
67XfrmOutPolDead:
68 Policy is dead
69XfrmOutPolError:
70 Policy error