This patch provides a "user timeout" support as described in RFC793. The
socket option is also needed for the the local half of RFC5482 "TCP User
Timeout Option".

TCP_USER_TIMEOUT is a TCP level socket option that takes an unsigned int,
when > 0, to specify the maximum amount of time in ms that transmitted
data may remain unacknowledged before TCP will forcefully close the
corresponding connection and return ETIMEDOUT to the application. If
0 is given, TCP will continue to use the system default.

Increasing the user timeouts allows a TCP connection to survive extended
periods without end-to-end connectivity. Decreasing the user timeouts
allows applications to "fail fast" if so desired. Otherwise it may take
upto 20 minutes with the current system defaults in a normal WAN
environment.

The socket option can be made during any state of a TCP connection, but
is only effective during the synchronized states of a connection
(ESTABLISHED, FIN-WAIT-1, FIN-WAIT-2, CLOSE-WAIT, CLOSING, or LAST-ACK).
Moreover, when used with the TCP keepalive (SO_KEEPALIVE) option,
TCP_USER_TIMEOUT will overtake keepalive to determine when to close a
connection due to keepalive failure.

The option does not change in anyway when TCP retransmits a packet, nor
when a keepalive probe will be sent.

This option, like many others, will be inherited by an acceptor from its
listener.
Signed-off-by: NH.K. Jerry Chu <hkchu@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Compiler is not smart enough to avoid a conditional branch.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SKBs can be "fragmented" in two ways, via a page array (called
skb_shinfo(skb)->frags[]) and via a list of SKBs (called
skb_shinfo(skb)->frag_list).

Since skb_has_frags() tests the latter, it's name is confusing
since it sounds more like it's testing the former.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Via setsockopt it is possible to reduce the socket RX buffer
(SO_RCVBUF). TCP method to select the initial window and window scaling
option in tcp_select_initial_window() currently misbehaves and do not
consider a reduced RX socket buffer via setsockopt.

Even though the server's RX buffer is reduced via setsockopt() to 256
byte (Initial Window 384 byte => 256 * 2 - (256 * 2 / 4)) the window
scale option is still 7:

192.168.1.38.40676 > 78.47.222.210.5001: Flags [S], seq 2577214362, win 5840, options [mss 1460,sackOK,TS val 338417 ecr 0,nop,wscale 0], length 0
78.47.222.210.5001 > 192.168.1.38.40676: Flags [S.], seq 1570631029, ack 2577214363, win 384, options [mss 1452,sackOK,TS val 2435248895 ecr 338417,nop,wscale 7], length 0
192.168.1.38.40676 > 78.47.222.210.5001: Flags [.], ack 1, win 5840, options [nop,nop,TS val 338421 ecr 2435248895], length 0

Within tcp_select_initial_window() the original space argument - a
representation of the rx buffer size - is expanded during
tcp_select_initial_window(). Only sysctl_tcp_rmem[2], sysctl_rmem_max
and window_clamp are considered to calculate the initial window.

This patch adjust the window_clamp argument if the user explicitly
reduce the receive buffer.
Signed-off-by: NHagen Paul Pfeifer <hagen@jauu.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NDmitry Kozlov <xeb@mail.ru>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now cmpxchg() is available on all arches, we can use it in
build_ehash_secret() and rt_bind_peer() instead of using spinlocks.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch removes the abstraction introduced by the union skb_shared_tx in
the shared skb data.

The access of the different union elements at several places led to some
confusion about accessing the shared tx_flags e.g. in skb_orphan_try().

    http://marc.info/?l=linux-netdev&m=128084897415886&w=2Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After commit 24b36f01 (netfilter: {ip,ip6,arp}_tables: dont block
bottom half more than necessary), lockdep can raise a warning
because we attempt to lock a spinlock with BH enabled, while
the same lock is usually locked by another cpu in a softirq context.

Disable again BH to avoid these lockdep warnings.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
Diagnosed-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_parse_md5sig_option doesn't check md5sig option (TCPOPT_MD5SIG)
length, but tcp_v[46]_inbound_md5_hash assume that it's at least 16
bytes long.
Signed-off-by: NDmitry Popov <dp@highloadlab.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

6c79bf0f subtracts PPPOE_SES_HLEN from mtu at
the front of ip_fragment(). So the later subtraction should be removed. The
MTU of 802.1q is also 1500, so MTU should not be changed.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NBart De Schuymer <bdschuym@pandora.bo>
----
 net/ipv4/ip_output.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)
Signed-off-by: NBart De Schuymer <bdschuym@pandora.bo>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Initial TCP thin-stream commit did not add getsockopt support for the new
socket options: TCP_THIN_LINEAR_TIMEOUTS and TCP_THIN_DUPACK. This adds support
for them.
Signed-off-by: NJosh Hunt <johunt@akamai.com>
Tested-by: NAndreas Petlund <apetlund@simula.no>
Acked-by: NAndreas Petlund <apetlund@simula.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The tuple got from unique_tuple() doesn't need to be really unique, so the
check for the unique tuple isn't necessary, when there isn't any other
choice. Eliminating the unnecessary nf_nat_used_tuple() can save some CPU
cycles too.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

The only user of unique_tuple() get_unique_tuple() doesn't care about the
return value of unique_tuple(), so make unique_tuple() return void (nothing).
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Use local variable hdrlen instead of ip_hdrlen(skb).
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

We currently disable BH for the whole duration of get_counters()

On machines with a lot of cpus and large tables, this might be too long.

We can disable preemption during the whole function, and disable BH only
while fetching counters for the current cpu.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

There is a bug in do_tcp_setsockopt(net/ipv4/tcp.c),
TCP_COOKIE_TRANSACTIONS case.
In some cases (when tp->cookie_values == NULL) new tcp_cookie_values
structure can be allocated (at cvp), but not bound to
tp->cookie_values. So a memory leak occurs.
Signed-off-by: NDmitry Popov <dp@highloadlab.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use skb->len for accounting as xt_quota does.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

use arp_hdr_len().
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

proto->unique_tuple() will be called finally, if the previous calls fail. This
patch checks the false condition of (range->flags &IP_NAT_RANGE_PROTO_RANDOM)
instead to avoid duplicate line of code: proto->unique_tuple().
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Add a new rt attribute, RTA_MARK, and use it in
rt_fill_info()/inet_rtm_getroute() to support following commands :

ip route get 192.168.20.110 mark NUMBER
ip route get 192.168.20.108 from 192.168.20.110 iif eth1 mark NUMBER
ip route list cache [192.168.20.110] mark NUMBER
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Network code uses the __packed macro instead of __attribute__((packed)).
Signed-off-by: NGustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It can happen that there are no packets in queue while calling
tcp_xmit_retransmit_queue(). tcp_write_queue_head() then returns
NULL and that gets deref'ed to get sacked into a local var.

There is no work to do if no packets are outstanding so we just
exit early.

This oops was introduced by 08ebd172 (tcp: remove tp->lost_out
guard to make joining diff nicer).
Signed-off-by: NIlpo Järvinen <ilpo.jarvinen@helsinki.fi>
Reported-by: NLennart Schulte <lennart.schulte@nets.rwth-aachen.de>
Tested-by: NLennart Schulte <lennart.schulte@nets.rwth-aachen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This was detected using two mcast router tables.  The
pimreg for the second interface did not have a specific
mrule, so packets received by it were handled by the
default table, which had nothing configured.

This caused the ipmr_fib_lookup to fail, causing
the memory leak.
Signed-off-by: NBen Greear <greearb@candelatech.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rfs: call sock_rps_record_flow() in tcp_splice_read()

call sock_rps_record_flow() in tcp_splice_read(), so the applications using
splice(2) or sendfile(2) can utilize RFS.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
----
 net/ipv4/tcp.c |    1 +
 1 file changed, 1 insertion(+)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

a new boolean flag no_autobind is added to structure proto to avoid the autobind
calls when the protocol is TCP. Then sock_rps_record_flow() is called int the
TCP's sendmsg() and sendpage() pathes.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
----
 include/net/inet_common.h |    4 ++++
 include/net/sock.h        |    1 +
 include/net/tcp.h         |    8 ++++----
 net/ipv4/af_inet.c        |   15 +++++++++------
 net/ipv4/tcp.c            |   11 +++++------
 net/ipv4/tcp_ipv4.c       |    3 +++
 net/ipv6/af_inet6.c       |    8 ++++----
 net/ipv6/tcp_ipv6.c       |    3 +++
 8 files changed, 33 insertions(+), 20 deletions(-)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

CodingStyle cleanups

EXPORT_SYMBOL should immediately follow the symbol declaration.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch makes IPV6 over IPv4 GRE tunnel propagate the transport
class field from the underlying IPV6 header to the IPV4 Type Of Service
field. Without the patch, all IPV6 packets in tunnel look the same to QoS.

This assumes that IPV6 transport class is exactly the same
as IPv4 TOS. Not sure if that is always the case?  Maybe need
to mask off some bits.

The mask and shift to get tclass is copied from ipv6/datagram.c
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Removal of unused integer variable in ip_fragment().
Signed-off-by: NGeorge Kadianakis <desnacked@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Avoid touching dst refcount in ip_fragment().
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can avoid a pair of atomic ops in ipt_REJECT send_reset()
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

postpone the checksum calculation, then if the output NIC supports checksum
offloading, we can utlize it. And though the output NIC doesn't support
checksum offloading, but we'll mangle this packet, this can free us from
updating the checksum, as the checksum calculation occurs later.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NPatrick McHardy <kaber@trash.net>

While using xfrm by MARK feature in
2.6.34 - 2.6.35 kernels, the mark
is always cleared in flowi structure via memset in
_decode_session4 (net/ipv4/xfrm4_policy.c), so
the policy lookup fails.
IPv6 code is affected by this bug too.
Signed-off-by: NPeter Kosyh <p.kosyh@gmail.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

add fast path for in-order fragments

As the fragments are sent in order in most of OSes, such as Windows, Darwin and
FreeBSD, it is likely the new fragments are at the end of the inet_frag_queue.
In the fast path, we check if the skb at the end of the inet_frag_queue is the
prev we expect.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
----
 include/net/inet_frag.h |    1 +
 net/ipv4/ip_fragment.c  |   12 ++++++++++++
 net/ipv6/reassembly.c   |   11 +++++++++++
 3 files changed, 24 insertions(+)
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

/proc/net/snmp and /proc/net/netstat expose SNMP counters.

Width of these counters is either 32 or 64 bits, depending on the size
of "unsigned long" in kernel.

This means user program parsing these files must already be prepared to
deal with 64bit values, regardless of user program being 32 or 64 bit.

This patch introduces 64bit snmp values for IPSTAT mib, where some
counters can wrap pretty fast if they are 32bit wide.

# netstat -s|egrep "InOctets|OutOctets"
    InOctets: 244068329096
    OutOctets: 244069348848
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We can pass a gfp argument to tso_fragment() and avoid GFP_ATOMIC
allocations sometimes.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

use this_cpu_ptr(p) instead of per_cpu_ptr(p, smp_processor_id())
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The LOG targets print the entire MAC header as one long string, which is not
readable very well:

IN=eth0 OUT= MAC=00:15:f2:24:91:f8:00:1b:24:dc:61:e6:08:00 ...

Add an option to decode known header formats (currently just ARPHRD_ETHER devices)
in their individual fields:

IN=eth0 OUT= MACSRC=00:1b:24:dc:61:e6 MACDST=00:15:f2:24:91:f8 MACPROTO=0800 ...
IN=eth0 OUT= MACSRC=00:1b:24:dc:61:e6 MACDST=00:15:f2:24:91:f8 MACPROTO=86dd ...

The option needs to be explicitly enabled by userspace to avoid breaking
existing parsers.
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Remove the comparison within the loop to print the macheader by prepending
the colon to all but the first printk.

Based on suggestion by Jan Engelhardt <jengelh@medozas.de>.
Signed-off-by: NPatrick McHardy <kaber@trash.net>

Allows use of ECN when syncookies are in effect by encoding ecn_ok
into the syn-ack tcp timestamp.

While at it, remove a uneeded #ifdef CONFIG_SYN_COOKIES.
With CONFIG_SYN_COOKIES=nm want_cookie is ifdef'd to 0 and gcc
removes the "if (0)".
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>