History log of /net/ipv4/Makefile
Revision Date Author Comments
b23a0e30038fdb1bff0bcb71ddd531c66fd0815d 31-Jul-2008 Robert Love <rlove@google.com> sysfs_net_ipv4: Add sysfs-based knobs for controlling TCP window size

Add a family of knobs to /sys/kernel/ipv4 for controlling the TCP window size:

tcp_wmem_min
tcp_wmem_def
tcp_wmem_max
tcp_rmem_min
tcp_rmem_def
tcp_rmem_max

This six values mirror the sysctl knobs in /proc/sys/net/ipv4/tcp_wmem and
/proc/sys/net/ipv4/tcp_rmem.

Sysfs, unlike sysctl, allows us to set and manage the files' permissions and
owners.

Signed-off-by: Robert Love <rlove@google.com>
0b5e8b8eeae40bae6ad7c7e91c97c3c0d0e57882 04-Oct-2014 Andy Zhou <azhou@nicira.com> net: Add Geneve tunneling protocol driver

This adds a device level support for Geneve -- Generic Network
Virtualization Encapsulation. The protocol is documented at
http://tools.ietf.org/html/draft-gross-geneve-01

Only protocol layer Geneve support is provided by this driver.
Openvswitch can be used for configuring, set up and tear down
functional Geneve tunnels.

Signed-off-by: Jesse Gross <jesse@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
e3118e8359bb7c59555aca60c725106e6d78c5ce 26-Sep-2014 Daniel Borkmann <dborkman@redhat.com> net: tcp: add DCTCP congestion control algorithm

This work adds the DataCenter TCP (DCTCP) congestion control
algorithm [1], which has been first published at SIGCOMM 2010 [2],
resp. follow-up analysis at SIGMETRICS 2011 [3] (and also, more
recently as an informational IETF draft available at [4]).

DCTCP is an enhancement to the TCP congestion control algorithm for
data center networks. Typical data center workloads are i.e.
i) partition/aggregate (queries; bursty, delay sensitive), ii) short
messages e.g. 50KB-1MB (for coordination and control state; delay
sensitive), and iii) large flows e.g. 1MB-100MB (data update;
throughput sensitive). DCTCP has therefore been designed for such
environments to provide/achieve the following three requirements:

* High burst tolerance (incast due to partition/aggregate)
* Low latency (short flows, queries)
* High throughput (continuous data updates, large file
transfers) with commodity, shallow buffered switches

The basic idea of its design consists of two fundamentals: i) on the
switch side, packets are being marked when its internal queue
length > threshold K (K is chosen so that a large enough headroom
for marked traffic is still available in the switch queue); ii) the
sender/host side maintains a moving average of the fraction of marked
packets, so each RTT, F is being updated as follows:

F := X / Y, where X is # of marked ACKs, Y is total # of ACKs
alpha := (1 - g) * alpha + g * F, where g is a smoothing constant

The resulting alpha (iow: probability that switch queue is congested)
is then being used in order to adaptively decrease the congestion
window W:

W := (1 - (alpha / 2)) * W

The means for receiving marked packets resp. marking them on switch
side in DCTCP is the use of ECN.

RFC3168 describes a mechanism for using Explicit Congestion Notification
from the switch for early detection of congestion, rather than waiting
for segment loss to occur.

However, this method only detects the presence of congestion, not
the *extent*. In the presence of mild congestion, it reduces the TCP
congestion window too aggressively and unnecessarily affects the
throughput of long flows [4].

DCTCP, as mentioned, enhances Explicit Congestion Notification (ECN)
processing to estimate the fraction of bytes that encounter congestion,
rather than simply detecting that some congestion has occurred. DCTCP
then scales the TCP congestion window based on this estimate [4],
thus it can derive multibit feedback from the information present in
the single-bit sequence of marks in its control law. And thus act in
*proportion* to the extent of congestion, not its *presence*.

Switches therefore set the Congestion Experienced (CE) codepoint in
packets when internal queue lengths exceed threshold K. Resulting,
DCTCP delivers the same or better throughput than normal TCP, while
using 90% less buffer space.

It was found in [2] that DCTCP enables the applications to handle 10x
the current background traffic, without impacting foreground traffic.
Moreover, a 10x increase in foreground traffic did not cause any
timeouts, and thus largely eliminates TCP incast collapse problems.

The algorithm itself has already seen deployments in large production
data centers since then.

We did a long-term stress-test and analysis in a data center, short
summary of our TCP incast tests with iperf compared to cubic:

This test measured DCTCP throughput and latency and compared it with
CUBIC throughput and latency for an incast scenario. In this test, 19
senders sent at maximum rate to a single receiver. The receiver simply
ran iperf -s.

The senders ran iperf -c <receiver> -t 30. All senders started
simultaneously (using local clocks synchronized by ntp).

This test was repeated multiple times. Below shows the results from a
single test. Other tests are similar. (DCTCP results were extremely
consistent, CUBIC results show some variance induced by the TCP timeouts
that CUBIC encountered.)

For this test, we report statistics on the number of TCP timeouts,
flow throughput, and traffic latency.

1) Timeouts (total over all flows, and per flow summaries):

CUBIC DCTCP
Total 3227 25
Mean 169.842 1.316
Median 183 1
Max 207 5
Min 123 0
Stddev 28.991 1.600

Timeout data is taken by measuring the net change in netstat -s
"other TCP timeouts" reported. As a result, the timeout measurements
above are not restricted to the test traffic, and we believe that it
is likely that all of the "DCTCP timeouts" are actually timeouts for
non-test traffic. We report them nevertheless. CUBIC will also include
some non-test timeouts, but they are drawfed by bona fide test traffic
timeouts for CUBIC. Clearly DCTCP does an excellent job of preventing
TCP timeouts. DCTCP reduces timeouts by at least two orders of
magnitude and may well have eliminated them in this scenario.

2) Throughput (per flow in Mbps):

CUBIC DCTCP
Mean 521.684 521.895
Median 464 523
Max 776 527
Min 403 519
Stddev 105.891 2.601
Fairness 0.962 0.999

Throughput data was simply the average throughput for each flow
reported by iperf. By avoiding TCP timeouts, DCTCP is able to
achieve much better per-flow results. In CUBIC, many flows
experience TCP timeouts which makes flow throughput unpredictable and
unfair. DCTCP, on the other hand, provides very clean predictable
throughput without incurring TCP timeouts. Thus, the standard deviation
of CUBIC throughput is dramatically higher than the standard deviation
of DCTCP throughput.

Mean throughput is nearly identical because even though cubic flows
suffer TCP timeouts, other flows will step in and fill the unused
bandwidth. Note that this test is something of a best case scenario
for incast under CUBIC: it allows other flows to fill in for flows
experiencing a timeout. Under situations where the receiver is issuing
requests and then waiting for all flows to complete, flows cannot fill
in for timed out flows and throughput will drop dramatically.

3) Latency (in ms):

CUBIC DCTCP
Mean 4.0088 0.04219
Median 4.055 0.0395
Max 4.2 0.085
Min 3.32 0.028
Stddev 0.1666 0.01064

Latency for each protocol was computed by running "ping -i 0.2
<receiver>" from a single sender to the receiver during the incast
test. For DCTCP, "ping -Q 0x6 -i 0.2 <receiver>" was used to ensure
that traffic traversed the DCTCP queue and was not dropped when the
queue size was greater than the marking threshold. The summary
statistics above are over all ping metrics measured between the single
sender, receiver pair.

The latency results for this test show a dramatic difference between
CUBIC and DCTCP. CUBIC intentionally overflows the switch buffer
which incurs the maximum queue latency (more buffer memory will lead
to high latency.) DCTCP, on the other hand, deliberately attempts to
keep queue occupancy low. The result is a two orders of magnitude
reduction of latency with DCTCP - even with a switch with relatively
little RAM. Switches with larger amounts of RAM will incur increasing
amounts of latency for CUBIC, but not for DCTCP.

4) Convergence and stability test:

This test measured the time that DCTCP took to fairly redistribute
bandwidth when a new flow commences. It also measured DCTCP's ability
to remain stable at a fair bandwidth distribution. DCTCP is compared
with CUBIC for this test.

At the commencement of this test, a single flow is sending at maximum
rate (near 10 Gbps) to a single receiver. One second after that first
flow commences, a new flow from a distinct server begins sending to
the same receiver as the first flow. After the second flow has sent
data for 10 seconds, the second flow is terminated. The first flow
sends for an additional second. Ideally, the bandwidth would be evenly
shared as soon as the second flow starts, and recover as soon as it
stops.

The results of this test are shown below. Note that the flow bandwidth
for the two flows was measured near the same time, but not
simultaneously.

DCTCP performs nearly perfectly within the measurement limitations
of this test: bandwidth is quickly distributed fairly between the two
flows, remains stable throughout the duration of the test, and
recovers quickly. CUBIC, in contrast, is slow to divide the bandwidth
fairly, and has trouble remaining stable.

CUBIC DCTCP

Seconds Flow 1 Flow 2 Seconds Flow 1 Flow 2
0 9.93 0 0 9.92 0
0.5 9.87 0 0.5 9.86 0
1 8.73 2.25 1 6.46 4.88
1.5 7.29 2.8 1.5 4.9 4.99
2 6.96 3.1 2 4.92 4.94
2.5 6.67 3.34 2.5 4.93 5
3 6.39 3.57 3 4.92 4.99
3.5 6.24 3.75 3.5 4.94 4.74
4 6 3.94 4 5.34 4.71
4.5 5.88 4.09 4.5 4.99 4.97
5 5.27 4.98 5 4.83 5.01
5.5 4.93 5.04 5.5 4.89 4.99
6 4.9 4.99 6 4.92 5.04
6.5 4.93 5.1 6.5 4.91 4.97
7 4.28 5.8 7 4.97 4.97
7.5 4.62 4.91 7.5 4.99 4.82
8 5.05 4.45 8 5.16 4.76
8.5 5.93 4.09 8.5 4.94 4.98
9 5.73 4.2 9 4.92 5.02
9.5 5.62 4.32 9.5 4.87 5.03
10 6.12 3.2 10 4.91 5.01
10.5 6.91 3.11 10.5 4.87 5.04
11 8.48 0 11 8.49 4.94
11.5 9.87 0 11.5 9.9 0

SYN/ACK ECT test:

This test demonstrates the importance of ECT on SYN and SYN-ACK packets
by measuring the connection probability in the presence of competing
flows for a DCTCP connection attempt *without* ECT in the SYN packet.
The test was repeated five times for each number of competing flows.

Competing Flows 1 | 2 | 4 | 8 | 16
------------------------------
Mean Connection Probability 1 | 0.67 | 0.45 | 0.28 | 0
Median Connection Probability 1 | 0.65 | 0.45 | 0.25 | 0

As the number of competing flows moves beyond 1, the connection
probability drops rapidly.

Enabling DCTCP with this patch requires the following steps:

DCTCP must be running both on the sender and receiver side in your
data center, i.e.:

sysctl -w net.ipv4.tcp_congestion_control=dctcp

Also, ECN functionality must be enabled on all switches in your
data center for DCTCP to work. The default ECN marking threshold (K)
heuristic on the switch for DCTCP is e.g., 20 packets (30KB) at
1Gbps, and 65 packets (~100KB) at 10Gbps (K > 1/7 * C * RTT, [4]).

In above tests, for each switch port, traffic was segregated into two
queues. For any packet with a DSCP of 0x01 - or equivalently a TOS of
0x04 - the packet was placed into the DCTCP queue. All other packets
were placed into the default drop-tail queue. For the DCTCP queue,
RED/ECN marking was enabled, here, with a marking threshold of 75 KB.
More details however, we refer you to the paper [2] under section 3).

There are no code changes required to applications running in user
space. DCTCP has been implemented in full *isolation* of the rest of
the TCP code as its own congestion control module, so that it can run
without a need to expose code to the core of the TCP stack, and thus
nothing changes for non-DCTCP users.

Changes in the CA framework code are minimal, and DCTCP algorithm
operates on mechanisms that are already available in most Silicon.
The gain (dctcp_shift_g) is currently a fixed constant (1/16) from
the paper, but we leave the option that it can be chosen carefully
to a different value by the user.

In case DCTCP is being used and ECN support on peer site is off,
DCTCP falls back after 3WHS to operate in normal TCP Reno mode.

ss {-4,-6} -t -i diag interface:

... dctcp wscale:7,7 rto:203 rtt:2.349/0.026 mss:1448 cwnd:2054
ssthresh:1102 ce_state 0 alpha 15 ab_ecn 0 ab_tot 735584
send 10129.2Mbps pacing_rate 20254.1Mbps unacked:1822 retrans:0/15
reordering:101 rcv_space:29200

... dctcp-reno wscale:7,7 rto:201 rtt:0.711/1.327 ato:40 mss:1448
cwnd:10 ssthresh:1102 fallback_mode send 162.9Mbps pacing_rate
325.5Mbps rcv_rtt:1.5 rcv_space:29200

More information about DCTCP can be found in [1-4].

[1] http://simula.stanford.edu/~alizade/Site/DCTCP.html
[2] http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp-final.pdf
[3] http://simula.stanford.edu/~alizade/Site/DCTCP_files/dctcp_analysis-full.pdf
[4] http://tools.ietf.org/html/draft-bensley-tcpm-dctcp-00

Joint work with Florian Westphal and Glenn Judd.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Glenn Judd <glenn.judd@morganstanley.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
23461551c00628c3f3fe9cf837bf53cf8f212b63 17-Sep-2014 Tom Herbert <therbert@google.com> fou: Support for foo-over-udp RX path

This patch provides a receive path for foo-over-udp. This allows
direct encapsulation of IP protocols over UDP. The bound destination
port is used to map to an IP protocol, and the XFRM framework
(udp_encap_rcv) is used to receive encapsulated packets. Upon
reception, the encapsulation header is logically removed (pointer
to transport header is advanced) and the packet is reinjected into
the receive path with the IP protocol indicated by the mapping.

Netlink is used to configure FOU ports. The configuration information
includes the port number to bind to and the IP protocol corresponding
to that port.

This should support GRE/UDP
(http://tools.ietf.org/html/draft-yong-tsvwg-gre-in-udp-encap-02),
as will as the other IP tunneling protocols (IPIP, SIT).

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
8024e02879ddd5042be02c70557f74cdc70b44b4 14-Jul-2014 Tom Herbert <therbert@google.com> udp: Add udp_sock_create for UDP tunnels to open listener socket

Added udp_tunnel.c which can contain some common functions for UDP
tunnels. The first function in this is udp_sock_create which is used
to open the listener port for a UDP tunnel.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
3328715e6c1fcb10cd86b0f3212d18290b7e4463 21-Feb-2014 Steffen Klassert <steffen.klassert@secunet.com> xfrm4: Add IPsec protocol multiplexer

This patch add an IPsec protocol multiplexer. With this
it is possible to add alternative protocol handlers as
needed for IPsec virtual tunnel interfaces.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
438e38fadca2f6e57eeecc08326c8a95758594d4 06-Jan-2014 Eric Dumazet <edumazet@google.com> gre_offload: statically build GRE offloading support

GRO/GSO layers can be enabled on a node, even if said
node is only forwarding packets.

This patch permits GSO (and upcoming GRO) support for GRE
encapsulated packets, even if the host has no GRE tunnel setup.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: H.K. Jerry Chu <hkchu@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
c50cd357887acf9fd7af3a5d492911bd825555a2 01-Jul-2013 Daniel Borkmann <dborkman@redhat.com> net: gre: move GSO functions to gre_offload

Similarly to TCP/UDP offloading, move all related GRE functions to
gre_offload.c to make things more explicit and similar to the rest
of the code.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
0e6fbc5b6c6218987c93b8c7ca60cf786062899d 18-Jun-2013 Pravin B Shelar <pshelar@nicira.com> ip_tunnels: extend iptunnel_xmit()

Refactor various ip tunnels xmit functions and extend iptunnel_xmit()
so that there is more code sharing.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
da5bab079f9b7d90ba234965a14914ace55e45e9 08-Jun-2013 Daniel Borkmann <dborkman@redhat.com> net: udp4: move GSO functions to udp_offload

Similarly to TCP offloading and UDPv6 offloading, move all related
UDPv4 functions to udp_offload.c to make things more explicit. Also,
by this, we can make those functions static.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
28850dc7c71da9d0c0e39246e9ff6913f41f8d0a 07-Jun-2013 Daniel Borkmann <dborkman@redhat.com> net: tcp: move GRO/GSO functions to tcp_offload

Would be good to make things explicit and move those functions to
a new file called tcp_offload.c, thus make this similar to tcpv6_offload.c.
While moving all related functions into tcp_offload.c, we can also
make some of them static, since they are only used there. Also, add
an explicit registration function.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
c54419321455631079c7d6e60bc732dd0c5914c5 25-Mar-2013 Pravin B Shelar <pshelar@nicira.com> GRE: Refactor GRE tunneling code.

Following patch refactors GRE code into ip tunneling code and GRE
specific code. Common tunneling code is moved to ip_tunnel module.
ip_tunnel module is written as generic library which can be used
by different tunneling implementations.

ip_tunnel module contains following components:
- packet xmit and rcv generic code. xmit flow looks like
(gre_xmit/ipip_xmit)->ip_tunnel_xmit->ip_local_out.
- hash table of all devices.
- lookup for tunnel devices.
- control plane operations like device create, destroy, ioctl, netlink
operations code.
- registration for tunneling modules, like gre, ipip etc.
- define single pcpu_tstats dev->tstats.
- struct tnl_ptk_info added to pass parsed tunnel packet parameters.

ipip.h header is renamed to ip_tunnel.h

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
c255a458055e459f65eb7b7f51dc5dbdd0caf1d8 01-Aug-2012 Andrew Morton <akpm@linux-foundation.org> memcg: rename config variables

Sanity:

CONFIG_CGROUP_MEM_RES_CTLR -> CONFIG_MEMCG
CONFIG_CGROUP_MEM_RES_CTLR_SWAP -> CONFIG_MEMCG_SWAP
CONFIG_CGROUP_MEM_RES_CTLR_SWAP_ENABLED -> CONFIG_MEMCG_SWAP_ENABLED
CONFIG_CGROUP_MEM_RES_CTLR_KMEM -> CONFIG_MEMCG_KMEM

[mhocko@suse.cz: fix missed bits]
Cc: Glauber Costa <glommer@parallels.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2100c8d2d9db23c0a09901a782bb4e3b21bee298 19-Jul-2012 Yuchung Cheng <ycheng@google.com> net-tcp: Fast Open base

This patch impelements the common code for both the client and server.

1. TCP Fast Open option processing. Since Fast Open does not have an
option number assigned by IANA yet, it shares the experiment option
code 254 by implementing draft-ietf-tcpm-experimental-options
with a 16 bits magic number 0xF989. This enables global experiments
without clashing the scarce(2) experimental options available for TCP.

When the draft status becomes standard (maybe), the client should
switch to the new option number assigned while the server supports
both numbers for transistion.

2. The new sysctl tcp_fastopen

3. A place holder init function

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1181412c1a671ed4e8fb1736f17e6ec617c68059 17-Jul-2012 Saurabh <saurabh.mohan@vyatta.com> net/ipv4: VTI support new module for ip_vti.

New VTI tunnel kernel module, Kconfig and Makefile changes.

Signed-off-by: Saurabh Mohan <saurabh.mohan@vyatta.com>
Reviewed-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
4aabd8ef8c43677cfee3e1e36c5a79edddb41942 10-Jul-2012 David S. Miller <davem@davemloft.net> tcp: Move dynamnic metrics handling into seperate file.

Signed-off-by: David S. Miller <davem@davemloft.net>
d1a4c0b37c296e600ffe08edb0db2dc1b8f550d7 11-Dec-2011 Glauber Costa <glommer@parallels.com> tcp memory pressure controls

This patch introduces memory pressure controls for the tcp
protocol. It uses the generic socket memory pressure code
introduced in earlier patches, and fills in the
necessary data in cg_proto struct.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
507dd7961eed950ef958a9a9536de987c52e81cd 09-Dec-2011 Pavel Emelyanov <xemul@parallels.com> udp_diag: Wire the udp_diag module into kbuild

Copy-s/tcp/udp/-paste from TCP bits.

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
c319b4d76b9e583a5d88d6bf190e079c4e43213d 13-May-2011 Vasiliy Kulikov <segoon@openwall.com> net: ipv4: add IPPROTO_ICMP socket kind

This patch adds IPPROTO_ICMP socket kind. It makes it possible to send
ICMP_ECHO messages and receive the corresponding ICMP_ECHOREPLY messages
without any special privileges. In other words, the patch makes it
possible to implement setuid-less and CAP_NET_RAW-less /bin/ping. In
order not to increase the kernel's attack surface, the new functionality
is disabled by default, but is enabled at bootup by supporting Linux
distributions, optionally with restriction to a group or a group range
(see below).

Similar functionality is implemented in Mac OS X:
http://www.manpagez.com/man/4/icmp/

A new ping socket is created with

socket(PF_INET, SOCK_DGRAM, PROT_ICMP)

Message identifiers (octets 4-5 of ICMP header) are interpreted as local
ports. Addresses are stored in struct sockaddr_in. No port numbers are
reserved for privileged processes, port 0 is reserved for API ("let the
kernel pick a free number"). There is no notion of remote ports, remote
port numbers provided by the user (e.g. in connect()) are ignored.

Data sent and received include ICMP headers. This is deliberate to:
1) Avoid the need to transport headers values like sequence numbers by
other means.
2) Make it easier to port existing programs using raw sockets.

ICMP headers given to send() are checked and sanitized. The type must be
ICMP_ECHO and the code must be zero (future extensions might relax this,
see below). The id is set to the number (local port) of the socket, the
checksum is always recomputed.

ICMP reply packets received from the network are demultiplexed according
to their id's, and are returned by recv() without any modifications.
IP header information and ICMP errors of those packets may be obtained
via ancillary data (IP_RECVTTL, IP_RETOPTS, and IP_RECVERR). ICMP source
quenches and redirects are reported as fake errors via the error queue
(IP_RECVERR); the next hop address for redirects is saved to ee_info (in
network order).

socket(2) is restricted to the group range specified in
"/proc/sys/net/ipv4/ping_group_range". It is "1 0" by default, meaning
that nobody (not even root) may create ping sockets. Setting it to "100
100" would grant permissions to the single group (to either make
/sbin/ping g+s and owned by this group or to grant permissions to the
"netadmins" group), "0 4294967295" would enable it for the world, "100
4294967295" would enable it for the users, but not daemons.

The existing code might be (in the unlikely case anyone needs it)
extended rather easily to handle other similar pairs of ICMP messages
(Timestamp/Reply, Information Request/Reply, Address Mask Request/Reply
etc.).

Userspace ping util & patch for it:
http://openwall.info/wiki/people/segoon/ping

For Openwall GNU/*/Linux it was the last step on the road to the
setuid-less distro. A revision of this patch (for RHEL5/OpenVZ kernels)
is in use in Owl-current, such as in the 2011/03/12 LiveCD ISOs:
http://mirrors.kernel.org/openwall/Owl/current/iso/

Initially this functionality was written by Pavel Kankovsky for
Linux 2.4.32, but unfortunately it was never made public.

All ping options (-b, -p, -Q, -R, -s, -t, -T, -M, -I), are tested with
the patch.

PATCH v3:
- switched to flowi4.
- minor changes to be consistent with raw sockets code.

PATCH v2:
- changed ping_debug() to pr_debug().
- removed CONFIG_IP_PING.
- removed ping_seq_fops.owner field (unused for procfs).
- switched to proc_net_fops_create().
- switched to %pK in seq_printf().

PATCH v1:
- fixed checksumming bug.
- CAP_NET_RAW may not create icmp sockets anymore.

RFC v2:
- minor cleanups.
- introduced sysctl'able group range to restrict socket(2).

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
3630b7c050d9c3564f143d595339fc06b888d6f3 02-Feb-2011 David S. Miller <davem@davemloft.net> ipv4: Remove fib_hash.

The time has finally come to remove the hash based routing table
implementation in ipv4.

FIB Trie is mature, well tested, and I've done an audit of it's code
to confirm that it implements insert, delete, and lookup with the same
identical semantics as fib_hash did.

If there are any semantic differences found in fib_trie, we should
simply fix them.

I've placed the trie statistic config option under advanced router
configuration.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Stephen Hemminger <shemminger@vyatta.com>
00959ade36acadc00e757f87060bf6e4501d545f 22-Aug-2010 Dmitry Kozlov <xeb@mail.ru> PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol)

PPP: introduce "pptp" module which implements point-to-point tunneling protocol using pppox framework
NET: introduce the "gre" module for demultiplexing GRE packets on version criteria
(required to pptp and ip_gre may coexists)
NET: ip_gre: update to use the "gre" module

This patch introduces then pptp support to the linux kernel which
dramatically speeds up pptp vpn connections and decreases cpu usage in
comparison of existing user-space implementation
(poptop/pptpclient). There is accel-pptp project
(https://sourceforge.net/projects/accel-pptp/) to utilize this module,
it contains plugin for pppd to use pptp in client-mode and modified
pptpd (poptop) to build high-performance pptp NAS.

There was many changes from initial submitted patch, most important are:
1. using rcu instead of read-write locks
2. using static bitmap instead of dynamically allocated
3. using vmalloc for memory allocation instead of BITS_PER_LONG + __get_free_pages
4. fixed many coding style issues
Thanks to Eric Dumazet.

Signed-off-by: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
cb7f6a7b716e801097b564dec3ccb58d330aef56 19-Sep-2008 Julius Volz <juliusv@google.com> IPVS: Move IPVS to net/netfilter/ipvs

Since IPVS now has partial IPv6 support, this patch moves IPVS from
net/ipv4/ipvs to net/netfilter/ipvs. It's a result of:

$ git mv net/ipv4/ipvs net/netfilter

and adapting the relevant Kconfigs/Makefiles to the new path.

Signed-off-by: Julius Volz <juliusv@google.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
db8dac20d5199307dcfcf4e01dac4bda5edf9e89 07-Mar-2008 David S. Miller <davem@davemloft.net> [UDP]: Revert udplite and code split.

This reverts commit db1ed684f6c430c4cdad67d058688b8a1b5e607c ("[IPV6]
UDP: Rename IPv6 UDP files."), commit
8be8af8fa4405652e6c0797db5465a4be8afb998 ("[IPV4] UDP: Move
IPv4-specific bits to other file.") and commit
e898d4db2749c6052072e9bc4448e396cbdeb06a ("[UDP]: Allow users to
configure UDP-Lite.").

First, udplite is of such small cost, and it is a core protocol just
like TCP and normal UDP are.

We spent enormous amounts of effort to make udplite share as much code
with core UDP as possible. All of that work is less valuable if we're
just going to slap a config option on udplite support.

It is also causing build failures, as reported on linux-next, showing
that the changeset was not tested very well. In fact, this is the
second build failure resulting from the udplite change.

Finally, the config options provided was a bool, instead of a modular
option. Meaning the udplite code does not even get build tested
by allmodconfig builds, and furthermore the user is not presented
with a reasonable modular build option which is particularly needed
by distribution vendors.

Signed-off-by: David S. Miller <davem@davemloft.net>
8be8af8fa4405652e6c0797db5465a4be8afb998 04-Mar-2008 YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> [IPV4] UDP: Move IPv4-specific bits to other file.

Move IPv4-specific UDP bits from net/ipv4/udp.c into (new) net/ipv4/udp_ipv4.c.
Rename net/ipv4/udplite.c to net/ipv4/udplite_ipv4.c.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
e898d4db2749c6052072e9bc4448e396cbdeb06a 29-Feb-2008 YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> [UDP]: Allow users to configure UDP-Lite.

Let's give users an option for disabling UDP-Lite (~4K).

old:
| text data bss dec hex filename
| 286498 12432 6072 305002 4a76a net/ipv4/built-in.o
| 193830 8192 3204 205226 321aa net/ipv6/ipv6.o

new (without UDP-Lite):
| text data bss dec hex filename
| 284086 12136 5432 301654 49a56 net/ipv4/built-in.o
| 191835 7832 3076 202743 317f7 net/ipv6/ipv6.o

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
9ba639797606acbcd97be886f41fbce163914e7b 05-Dec-2007 Pavel Emelyanov <xemul@openvz.org> [IPV4]: Cleanup the sysctl_net_ipv4.c file

This includes several cleanups:

* tune Makefile to compile out this file when SYSCTL=n. Now
it looks like net/core/sysctl_net_core.c one;
* move the ipv4_config to af_inet.c to exist all the time;
* remove additional sysctl_ip_nonlocal_bind declaration
(it is already declared in net/ip.h);
* remove no nonger needed ifdefs from this file.

This is a preparation for using ctl paths for net/ipv4/
sysctl table.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
7eb95156d9dce2f59794264db336ce007d71638b 15-Oct-2007 Pavel Emelyanov <xemul@openvz.org> [INET]: Collect frag queues management objects together

There are some objects that are common in all the places
which are used to keep track of frag queues, they are:

* hash table
* LRU list
* rw lock
* rnd number for hash function
* the number of queues
* the amount of memory occupied by queues
* secret timer

Move all this stuff into one structure (struct inet_frags)
to make it possible use them uniformly in the future. Like
with the previous patch this mostly consists of hunks like

- write_lock(&ipfrag_lock);
+ write_lock(&ip4_frags.lock);

To address the issue with exporting the number of queues and
the amount of memory occupied by queues outside the .c file
they are declared in, I introduce a couple of helpers.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
71c87e0cedca843162206c698cfa02e5fea9e2e3 09-Aug-2007 Jan-Bernd Themann <themann@de.ibm.com> [NET]: Generic Large Receive Offload for TCP traffic

This patch provides generic Large Receive Offload (LRO) functionality
for IPv4/TCP traffic.

LRO combines received tcp packets to a single larger tcp packet and
passes them then to the network stack in order to increase performance
(throughput). The interface supports two modes: Drivers can either
pass SKBs or fragment lists to the LRO engine.

Signed-off-by: Jan-Bernd Themann <themann@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
e06e7c615877026544ad7f8b309d1a3706410383 11-Jun-2007 David S. Miller <davem@sunset.davemloft.net> [IPV4]: The scheduled removal of multipath cached routing support.

With help from Chris Wedgwood.

Signed-off-by: David S. Miller <davem@davemloft.net>
5e0f04351d11e07a23b5ab4914282cbb78027e50 25-Apr-2007 Herbert Xu <herbert@gondor.apana.org.au> [IPV4]: Consolidate common SNMP code

This patch moves the SNMP code shared between IPv4/IPv6 from proc.c
into net/ipv4/af_inet.c. This makes sense because these functions
aren't specific to /proc.

As a result we can again skip proc.o if /proc is disabled.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
bb7ec6dfb5aa32b5b4d7d6388b4098b33cd01e8c 25-Apr-2007 YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> [IPV4]: Fix build without procfs.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
c462238d6a6d8ee855bda10f9fff442971540ed2 21-Apr-2007 Stephen Hemminger <shemminger@linux-foundation.org> [TCP]: TCP Illinois congestion control (rev3)

This is an implementation of TCP Illinois invented by Shao Liu
at University of Illinois. It is a another variant of Reno which adapts
the alpha and beta parameters based on RTT. The basic idea is to increase
window less rapidly as delay approaches the maximum. See the papers
and talks to get a more complete description.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
5ef814753eb810d900fbd77af7c87f6d04f0e551 22-Feb-2007 Angelo P. Castellani <angelo.castellani@gmail.con> [TCP] YeAH-TCP: algorithm implementation

YeAH-TCP is a sender-side high-speed enabled TCP congestion control
algorithm, which uses a mixed loss/delay approach to compute the
congestion window. It's design goals target high efficiency, internal,
RTT and Reno fairness, resilience to link loss while keeping network
elements load as low as possible.

For further details look here:
http://wil.cs.caltech.edu/pfldnet2007/paper/YeAH_TCP.pdf

Signed-off-by: Angelo P. Castellani <angelo.castellani@gmail.con>
Signed-off-by: David S. Miller <davem@davemloft.net>
ba4e58eca8aa9473b44fdfd312f26c4a2e7798b3 27-Nov-2006 Gerrit Renker <gerrit@erg.abdn.ac.uk> [NET]: Supporting UDP-Lite (RFC 3828) in Linux

This is a revision of the previously submitted patch, which alters
the way files are organized and compiled in the following manner:

* UDP and UDP-Lite now use separate object files
* source file dependencies resolved via header files
net/ipv{4,6}/udp_impl.h
* order of inclusion files in udp.c/udplite.c adapted
accordingly

[NET/IPv4]: Support for the UDP-Lite protocol (RFC 3828)

This patch adds support for UDP-Lite to the IPv4 stack, provided as an
extension to the existing UDPv4 code:
* generic routines are all located in net/ipv4/udp.c
* UDP-Lite specific routines are in net/ipv4/udplite.c
* MIB/statistics support in /proc/net/snmp and /proc/net/udplite
* shared API with extensions for partial checksum coverage

[NET/IPv6]: Extension for UDP-Lite over IPv6

It extends the existing UDPv6 code base with support for UDP-Lite
in the same manner as per UDPv4. In particular,
* UDPv6 generic and shared code is in net/ipv6/udp.c
* UDP-Litev6 specific extensions are in net/ipv6/udplite.c
* MIB/statistics support in /proc/net/snmp6 and /proc/net/udplite6
* support for IPV6_ADDRFORM
* aligned the coding style of protocol initialisation with af_inet6.c
* made the error handling in udpv6_queue_rcv_skb consistent;
to return `-1' on error on all error cases
* consolidation of shared code

[NET]: UDP-Lite Documentation and basic XFRM/Netfilter support

The UDP-Lite patch further provides
* API documentation for UDP-Lite
* basic xfrm support
* basic netfilter support for IPv4 and IPv6 (LOG target)

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
0a69452cb45add0841c2bc1e75c25f6bd4f1d8d9 04-Oct-2006 Diego Beltrami <diego.beltrami@gmail.com> [XFRM]: BEET mode

This patch introduces the BEET mode (Bound End-to-End Tunnel) with as
specified by the ietf draft at the following link:

http://www.ietf.org/internet-drafts/draft-nikander-esp-beet-mode-06.txt

The patch provides only single family support (i.e. inner family =
outer family).

Signed-off-by: Diego Beltrami <diego.beltrami@gmail.com>
Signed-off-by: Miika Komu <miika@iki.fi>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Abhinav Pathak <abhinav.pathak@hiit.fi>
Signed-off-by: Jeff Ahrenholz <ahrenholz@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
446fda4f26822b2d42ab3396aafcedf38a9ff2b6 04-Aug-2006 Paul Moore <paul.moore@hp.com> [NetLabel]: CIPSOv4 engine

Add support for the Commercial IP Security Option (CIPSO) to the IPv4
network stack. CIPSO has become a de-facto standard for
trusted/labeled networking amongst existing Trusted Operating Systems
such as Trusted Solaris, HP-UX CMW, etc. This implementation is
designed to be used with the NetLabel subsystem to provide explicit
packet labeling to LSM developers.

The CIPSO/IPv4 packet labeling works by the LSM calling a NetLabel API
function which attaches a CIPSO label (IPv4 option) to a given socket;
this in turn attaches the CIPSO label to every packet leaving the
socket without any extra processing on the outbound side. On the
inbound side the individual packet's sk_buff is examined through a
call to a NetLabel API function to determine if a CIPSO/IPv4 label is
present and if so the security attributes of the CIPSO label are
returned to the caller of the NetLabel API function.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
c427d27452b41378e305af80db5757da048dd38e 10-Jul-2006 David S. Miller <davem@davemloft.net> [TCP]: Remove TCP Compound

This reverts: f890f921040fef6a35e39d15b729af1fd1a35f29

The inclusion of TCP Compound needs to be reverted at this time
because it is not 100% certain that this code conforms to the
requirements of Developer's Certificate of Origin 1.1 paragraph (b).

Signed-off-by: David S. Miller <davem@davemloft.net>
a42e9d6ce89cfd19aee9f990b7231ce697f0d00f 06-Jun-2006 Stephen Hemminger <shemminger@osdl.org> [TCP]: TCP Probe congestion window tracing

This adds a new module for tracking TCP state variables non-intrusively
using kprobes. It has a simple /proc interface that outputs one line
for each packet received. A sample usage is to collect congestion
window and ssthresh over time graphs.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
f890f921040fef6a35e39d15b729af1fd1a35f29 06-Jun-2006 Angelo P. Castellani <angelo.castellani@gmail.com> [TCP]: TCP Compound congestion control

TCP Compound is a sender-side only change to TCP that uses
a mixed Reno/Vegas approach to calculate the cwnd.

For further details look here:
ftp://ftp.research.microsoft.com/pub/tr/TR-2005-86.pdf

Signed-off-by: Angelo P. Castellani <angelo.castellani@gmail.com>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
76f1017757aa0c308a0b83ca611c9a89ee9a79a4 06-Jun-2006 Bin Zhou <zhou0022@ntu.edu.sg> [TCP]: TCP Veno congestion control

TCP Veno module is a new congestion control module to improve TCP
performance over wireless networks. The key innovation in TCP Veno is
the enhancement of TCP Reno/Sack congestion control algorithm by using
the estimated state of a connection based on TCP Vegas. This scheme
significantly reduces "blind" reduction of TCP window regardless of
the cause of packet loss.

This work is based on the research paper "TCP Veno: TCP Enhancement
for Transmission over Wireless Access Networks." C. P. Fu, S. C. Liew,
IEEE Journal on Selected Areas in Communication, Feb. 2003.

Original paper and many latest research works on veno:
http://www.ntu.edu.sg/home/ascpfu/veno/veno.html

Signed-off-by: Bin Zhou <zhou0022@ntu.edu.sg>
Cheng Peng Fu <ascpfu@ntu.edu.sg>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
7c106d7e782bd4805f39da30e81018f861b4b8c5 06-Jun-2006 Wong Hoi Sing Edison <hswong3i@gmail.com> [TCP]: TCP Low Priority congestion control

TCP Low Priority is a distributed algorithm whose goal is to utilize only
the excess network bandwidth as compared to the ``fair share`` of
bandwidth as targeted by TCP. Available from:
http://www.ece.rice.edu/~akuzma/Doc/akuzma/TCP-LP.pdf

Original Author:
Aleksandar Kuzmanovic <akuzma@northwestern.edu>

See http://www-ece.rice.edu/networks/TCP-LP/ for their implementation.
As of 2.6.13, Linux supports pluggable congestion control algorithms.
Due to the limitation of the API, we take the following changes from
the original TCP-LP implementation:
o We use newReno in most core CA handling. Only add some checking
within cong_avoid.
o Error correcting in remote HZ, therefore remote HZ will be keeped
on checking and updating.
o Handling calculation of One-Way-Delay (OWD) within rtt_sample, sicne
OWD have a similar meaning as RTT. Also correct the buggy formular.
o Handle reaction for Early Congestion Indication (ECI) within
pkts_acked, as mentioned within pseudo code.
o OWD is handled in relative format, where local time stamp will in
tcp_time_stamp format.

Port from 2.4.19 to 2.6.16 as module by:
Wong Hoi Sing Edison <hswong3i@gmail.com>
Hung Hing Lun <hlhung3i@gmail.com>

Signed-off-by: Wong Hoi Sing Edison <hswong3i@gmail.com>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
b59f45d0b2878ab76f8053b0973654e6621828ee 28-May-2006 Herbert Xu <herbert@gondor.apana.org.au> [IPSEC] xfrm: Abstract out encapsulation modes

This patch adds the structure xfrm_mode. It is meant to represent
the operations carried out by transport/tunnel modes.

By doing this we allow additional encapsulation modes to be added
without clogging up the xfrm_input/xfrm_output paths.

Candidate modes include 4-to-6 tunnel mode, 6-to-4 tunnel mode, and
BEET modes.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
d2acc3479cbccd5cfbca6c787be713ef1de12ec6 28-Mar-2006 Herbert Xu <herbert@gondor.apana.org.au> [INET]: Introduce tunnel4/tunnel6

Basically this patch moves the generic tunnel protocol stuff out of
xfrm4_tunnel/xfrm6_tunnel and moves it into the new files of tunnel4.c
and tunnel6 respectively.

The reason for this is that the problem that Hugo uncovered is only
the tip of the iceberg. The real problem is that when we removed the
dependency of ipip on xfrm4_tunnel we didn't really consider the module
case at all.

For instance, as it is it's possible to build both ipip and xfrm4_tunnel
as modules and if the latter is loaded then ipip simply won't load.

After considering the alternatives I've decided that the best way out of
this is to restore the dependency of ipip on the non-xfrm-specific part
of xfrm4_tunnel. This is acceptable IMHO because the intention of the
removal was really to be able to use ipip without the xfrm subsystem.
This is still preserved by this patch.

So now both ipip/xfrm4_tunnel depend on the new tunnel4.c which handles
the arbitration between the two. The order of processing is determined
by a simple integer which ensures that ipip gets processed before
xfrm4_tunnel.

The situation for ICMP handling is a little bit more complicated since
we may not have enough information to determine who it's for. It's not
a big deal at the moment since the xfrm ICMP handlers are basically
no-ops. In future we can deal with this when we look at ICMP caching
in general.

The user-visible change to this is the removal of the TUNNEL Kconfig
prompts. This makes sense because it can only be used through IPCOMP
as it stands.

The addition of the new modules shouldn't introduce any problems since
module dependency will cause them to be loaded.

Oh and I also turned some unnecessary pskb's in IPv6 related to this
patch to skb's.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
bb94aa169eaa6e713a429370d37388722f08666f 10-Jan-2006 Patrick McHardy <kaber@trash.net> [NETFILTER]: net/ipv[46]/netfilter.c cleanups

Don't wrap entire file in #ifdef CONFIG_NETFILTER, remove a few
unneccessary includes.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
df3271f3361b61ce02da0026b4a53e63bc2720cb 14-Dec-2005 Stephen Hemminger <shemminger@osdl.org> [TCP] BIC: CUBIC window growth (2.0)

Replace existing BIC version 1.1 with new version 2.0.
The main change is to replace the window growth function
with a cubic function as described in:
http://www.csc.ncsu.edu/faculty/rhee/export/bitcp/cubic-paper.pdf

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
17b085eacef81a6286bd478f2ec75e04abb091cb 12-Aug-2005 Arnaldo Carvalho de Melo <acme@mandriva.com> [INET_DIAG]: Move the tcp_diag interface to the proper place

With this the previous setup is back, i.e. tcp_diag can be built as a module,
as dccp_diag and both share the infrastructure available in inet_diag.

If one selects CONFIG_INET_DIAG as module CONFIG_INET_TCP_DIAG will also be
built as a module, as will CONFIG_INET_DCCP_DIAG, if CONFIG_IP_DCCP was
selected static or as a module, if CONFIG_INET_DIAG is y, being statically
linked CONFIG_INET_TCP_DIAG will follow suit and CONFIG_INET_DCCP_DIAG will be
built in the same manner as CONFIG_IP_DCCP.

Now to aim at UDP, converting it to use inet_hashinfo, so that we can use
iproute2 for UDP sockets as well.

Ah, just to show an example of this new infrastructure working for DCCP :-)

[root@qemu ~]# ./ss -dane
State Recv-Q Send-Q Local Address:Port Peer Address:Port
LISTEN 0 0 *:5001 *:* ino:942 sk:cfd503a0
ESTAB 0 0 127.0.0.1:5001 127.0.0.1:32770 ino:943 sk:cfd50a60
ESTAB 0 0 127.0.0.1:32770 127.0.0.1:5001 ino:947 sk:cfd50700
TIME-WAIT 0 0 127.0.0.1:32769 127.0.0.1:5001 timer:(timewait,3.430ms,0) ino:0 sk:cf209620

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
a8c2190ee7da1a1dc68ff1a6b5f03feb61e523a5 12-Aug-2005 Arnaldo Carvalho de Melo <acme@mandriva.com> [INET_DIAG]: Rename tcp_diag.[ch] to inet_diag.[ch]

Next changeset will introduce net/ipv4/tcp_diag.c, moving the code that was put
transitioanlly in inet_diag.c.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
73c1f4a033675f168df7e98bbeeafca3c644b8a6 12-Aug-2005 Arnaldo Carvalho de Melo <acme@mandriva.com> [TCPDIAG]: Just rename everything to inet_diag

Next changeset will rename tcp_diag.[ch] to inet_diag.[ch].

I'm taking this longer route so as to easy review, making clear the changes
made all along the way.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
3f421baa4720b708022f8bcc52a61e5cd6f10bf8 10-Aug-2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> [NET]: Just move the inet_connection_sock function from tcp sources

Completing the previous changeset, this also generalises tcp_v4_synq_add,
renaming it to inet_csk_reqsk_queue_hash_add, already geing used in the
DCCP tree, which I plan to merge RSN.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
e48c414ee61f4ac8d5cff2973e66a7cbc8a93aa5 10-Aug-2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> [INET]: Generalise the TCP sock ID lookup routines

And also some TIME_WAIT functions.

[acme@toy net-2.6.14]$ grep built-in /tmp/before.size /tmp/after.size
/tmp/before.size: 282955 13122 9312 305389 4a8ed net/ipv4/built-in.o
/tmp/after.size: 281566 13122 9312 304000 4a380 net/ipv4/built-in.o
[acme@toy net-2.6.14]$

I kept them still inlined, will uninline at some point to see what
would be the performance difference.

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
77d8bf9c6208eb535f05718168ffcc476be0ca8c 10-Aug-2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net> [INET]: Move the TCP hashtable functions/structs to inet_hashtables.[ch]

Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
020b4c12dbe3868d792a01d7c1470cd837abe10f 10-Aug-2005 Harald Welte <laforge@netfilter.org> [NETFILTER]: Move ipv4 specific code from net/core/netfilter.c to net/ipv4/netfilter.c

Netfilter cleanup
- Move ipv4 code from net/core/netfilter.c to net/ipv4/netfilter.c
- Move ipv6 netfilter code from net/ipv6/ip6_output.c to net/ipv6/netfilter.c

Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
5e43db7730e7cef7d37968ea789c41392519a864 28-Jul-2005 Matt Mackall <mpm@selenic.com> [NET]: Move in_aton from net/ipv4/utils.c to net/core/utils.c

Move in_aton to allow netpoll and pktgen to work without the rest of
the IPv4 stack. Fix whitespace and add comment for the odd placement.

Delete now-empty net/ipv4/utils.c

Re-enable netpoll/netconsole without CONFIG_INET

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
0e57976b6376f7fda6bef8b7dee2a3c8819ec9e9 23-Jun-2005 John Heffner <jheffner@psc.edu> [TCP]: Add Scalable TCP congestion control module.

This patch implements Tom Kelly's Scalable TCP congestion control algorithm
for the modular framework.

The algorithm has some nice scaling properties, and has been used a fair bit
in research, though is known to have significant fairness issues, so it's not
really suitable for general purpose use.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
a7868ea68d29eb2c037952aeb3b549cf05749a18 23-Jun-2005 Baruch Even <baruch@ev-en.org> [TCP]: Add H-TCP congestion control module.

H-TCP is a congestion control algorithm developed at the Hamilton Institute, by
Douglas Leith and Robert Shorten. It is extending the standard Reno algorithm
with mode switching is thus a relatively simple modification.

H-TCP is defined in a layered manner as it is still a research platform. The
basic form includes the modification of beta according to the ratio of maxRTT
to min RTT and the alpha=2*factor*(1-beta) relation, where factor is dependant
on the time since last congestion.

The other layers improve convergence by adding appropriate factors to alpha.

The following patch implements the H-TCP algorithm in it's basic form.

Signed-Off-By: Baruch Even <baruch@ev-en.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
b87d8561d8667d221b728ccdcb18eb95b16a687b 23-Jun-2005 Stephen Hemminger <shemminger@osdl.org> [TCP]: Add TCP Vegas congestion control module.

TCP Vegas code modified for the new TCP infrastructure.
Vegas now uses microsecond resolution timestamps for
better estimation of performance over higher speed links.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
835b3f0c0d7e1f716c45ec576662eac7a68b8548 23-Jun-2005 Daniele Lacamera <(root at danielinux.net)net> [TCP]: Add TCP Hybla congestion control module.

TCP Hybla congestion avoidance.

- "In heterogeneous networks, TCP connections that incorporate a
terrestrial or satellite radio link are greatly disadvantaged with
respect to entirely wired connections, because of their longer round
trip times (RTTs). To cope with this problem, a new TCP proposal, the
TCP Hybla, is presented and discussed in the paper[1]. It stems from an
analytical evaluation of the congestion window dynamics in the TCP
standard versions (Tahoe, Reno, NewReno), which suggests the necessary
modifications to remove the performance dependence on RTT.[...]"[1]

[1]: Carlo Caini, Rosario Firrincieli, "TCP Hybla: a TCP enhancement for
heterogeneous networks",
International Journal of Satellite Communications and Networking
Volume 22, Issue 5 , Pages 547 - 566. September 2004.

Signed-off-by: Daniele Lacamera (root at danielinux.net)net
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
a628d29b56d3f420bf3ff1d7543a9caf3ce3b994 23-Jun-2005 John Heffner <jheffner@psc.edu> [TCP]: Add High Speed TCP congestion control module.

Sally Floyd's high speed TCP congestion control.
This is useful for comparison and research.

Signed-off-by: John Heffner <jheffner@psc.edu>
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
8727076289ec55298a05cabddf02b374d13c1624 23-Jun-2005 Stephen Hemminger <shemminger@osdl.org> [TCP]: Add TCP Westwood congestion control module.

This is the existing 2.6.12 Westwood code moved from tcp_input
to the new congestion framework. A lot of the inline functions
have been eliminated to try and make it clearer.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
83803034f4233d810c4adc52008921da060c55d1 23-Jun-2005 Stephen Hemminger <shemminger@osdl.org> [TCP]: Add TCP BIC congestion control module.

TCP BIC congestion control reworked to use the new congestion control
infrastructure. This version is more up to date than the BIC
code in 2.6.12; it incorporates enhancements from BICTCP 1.1,
to handle low latency links.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
317a76f9a44b437d6301718f4e5d08bd93f98da7 23-Jun-2005 Stephen Hemminger <shemminger@osdl.org> [TCP]: Add pluggable congestion control algorithm infrastructure.

Allow TCP to have multiple pluggable congestion control algorithms.
Algorithms are defined by a set of operations and can be built in
or modules. The legacy "new RENO" algorithm is used as a starting
point and fallback.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
19baf839ff4a8daa1f2a7400897094fc18e4f5e9 21-Jun-2005 Robert Olsson <Robert.Olsson@data.slu.se> [IPV4]: Add LC-Trie FIB lookup algorithm.

Signed-off-by: Robert Olsson <Robert.Olsson@data.slu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 17-Apr-2005 Linus Torvalds <torvalds@ppc970.osdl.org> Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!