Adding casts of objects to the same type is unnecessary
and confusing for a human reader.

For example, this cast:

	int y;
	int *p = (int *)&y;

I used the coccinelle script below to find and remove these
unnecessary casts.  I manually removed the conversions this
script produces of casts with __force and __user.

@@
type T;
T *p;
@@

-	(T *)p
+	p
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tcp_make_synack() clones the dst, and callers release it.

We can avoid two atomic operations per SYNACK if tcp_make_synack()
consumes dst instead of cloning it.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While testing how linux behaves on SYNFLOOD attack on multiqueue device
(ixgbe), I found that SYNACK messages were dropped at Qdisc level
because we send them all on a single queue.

Obvious choice is to reflect incoming SYN packet @queue_mapping to
SYNACK packet.

Under stress, my machine could only send 25.000 SYNACK per second (for
200.000 incoming SYN per second). NIC : ixgbe with 16 rx/tx queues.

After patch, not a single SYNACK is dropped.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since commit ad0081e4
"ipv6: Fragment locally generated tunnel-mode IPSec6 packets as needed"
the fragment of packets is incorrect.
because tunnel mode needs IPsec headers and trailer for all fragments,
while on transport mode it is sufficient to add the headers to the
first fragment and the trailer to the last.

so modify mtu and maxfraglen base on ipsec mode and if fragment is first
or last.

with my test,it work well(every fragment's size is the mtu)
and does not trigger slow fragment path.

Changes from v1:
	though optimization, mtu_prev and maxfraglen_prev can be delete.
	replace xfrm mode codes with dst_entry's new frag DST_XFRM_TUNNEL.
	add fuction ip6_append_data_mtu to make codes clearer.
Signed-off-by: NGao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Corrects the function that determines the esp payload size. The calculations
done in esp{4,6}_get_mtu() lead to overlength frames in transport mode for
certain mtu values and suboptimal frames for others.

According to what is done, mainly in esp{,6}_output() and tcp_mtu_to_mss(),
net_header_len must be taken into account before doing the alignment
calculation.
Signed-off-by: NBenjamin Poirier <bpoirier@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The following tightens the padding check from commit
c1412fce :

* Take into account combinations of consecutive Pad1 and PadN.

* Catch the corner case of when only padding is present in the
  header, when the extention header length is 0 (i.e., 8 bytes).
  In this case, the header would have exactly 6 bytes of padding:

+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
:  Next Header  : Hdr Ext Len=0 :                               :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+                               +
:                        Padding (Pad1 or PadN)                 :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Signed-off-by: NEldad Zack <eldad@fogrefinery.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ip6_frag_reasm() can use skb_try_coalesce() to build optimized skb,
reducing memory used by them (truesize), and reducing number of cache
line misses and overhead for the consumer.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixed space issues relating to operators found by
checkpatch.pl tool in net/ipv6/udp.c
Signed-off-by: NJeffrin Jose <ahiliation@yahoo.co.in>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixed a trailing white space issue found by
checkpatch.pl tool in net/ipv6/udp.c
Signed-off-by: NJeffrin Jose <ahiliation@yahoo.co.in>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the allfrag feature has been set on a host route (due to an ICMPv6
Packet Too Big received indicating a MTU of less than 1280), we hit a
very slow behavior in TCP stack, because all big packets are dropped and
only a retransmit timer is able to push one MSS frame every 200 ms.

One way to handle this is to disable GSO on the socket the first time a
super packet is dropped. Adding a specific dst_allfrag() in the fast
path is probably overkill since the dst_allfrag() case almost never
happen.

Result on netperf TCP_STREAM, one flow :

Before : 60 kbit/sec
After : 1.6 Gbit/sec
Reported-by: NTore Anderson <tore@fud.no>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Tested-by: NTore Anderson <tore@fud.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Mostly bool conversions, some inline removals and const additions.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Quoting Tore Anderson from :

If the allfrag feature has been set on a host route (due to an ICMPv6
Packet Too Big received indicating a MTU of less than 1280),
TCP SYN/ACK packets to that destination appears to get an incorrect
TCP checksum. This in turn means they are thrown away as invalid.

In the case of an IPv4 client behind a link with a MTU of less than
1260, accessing an IPv6 server through a stateless translator,
this means that the client can only download a single large file
from the server, because once it is in the server's routing cache
with the allfrag feature set, new TCP connections can no longer
be established.

</endquote>

It appears ip6_fragment() doesn't handle CHECKSUM_PARTIAL properly.

As network drivers are not prepared to fetch correct transport header, a
safe fix is to call skb_checksum_help() before fragmenting packet.
Reported-by: NTore Anderson <tore@fud.no>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Tested-by: NTore Anderson <tore@fud.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

csummode variable is always CHECKSUM_NONE in ip6_append_data()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ipv6_opt_accepted() returns a bool, and can use const pointers

ipv6_addr_equal(), ipv6_addr_any(), ipv6_addr_loopback(),
ipv6_addr_orchid() return a bool.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

- match() method returns a boolean
- return (A && B && C && D) -> return A && B && C && D
- fix indentation
Signed-off-by: NEric Dumazet <edumazet@google.com>

The padding destination or hop-by-hop option is called Pad1 and not Pad0.

See RFC2460 (4.2) or the IANA ipv6-parameters registry:
http://www.iana.org/assignments/ipv6-parameters/ipv6-parameters.xmlSigned-off-by: NEldad Zack <eldad@fogrefinery.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

bool conversions where possible.

__inline__ -> inline

space cleanups
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Why use several macros when one will do?

Convert the multiple ND_PRINTKx macros to a single
ND_PRINTK macro.  Use the new net_<level>_ratelimited
mechanism too.

Add pr_fmt with "ICMPv6: " as prefix.
Remove embedded ICMPv6 prefixes from messages.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the current debugging style and enable dynamic_debug.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add #define pr_fmt(fmt) as appropriate.

Add "IPv6: " to appropriate files.

Convert printk(KERN_<LEVEL> to pr_<level> (but not KERN_DEBUG).
Standardize on "%s: " not "%s(): " when emitting __func__.
Use "%s: ", __func__ instead of embedding function name.
Coalesce formats, align arguments.

ADDRCONF output is now prefixed with "IPv6: "
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are going to delete the Token ring support.  This removes any
special processing in the core networking for token ring, (aside
from net/tr.c itself), leaving the drivers and remaining tokenring
support present but inert.

The mass removal of the drivers and net/tr.c will be in a separate
commit, so that the history of these files that we still care
about won't have the giant deletion tied into their history.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Standardize the net core ratelimited logging functions.

Coalesce formats, align arguments.
Change a printk then vprintk sequence to use printf extension %pV.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

By making this a standalone config option (auto-selected as needed),
selecting CRYPTO from here rather than from XFRM (which is boolean)
allows the core crypto code to become a module again even when XFRM=y.
Signed-off-by: NJan Beulich <jbeulich@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

af_inet6.c:80: ERROR: do not initialise statics to 0 or NULL
af_inet6.c:259: ERROR: spaces required around that '=' (ctx:VxV)
af_inet6.c:394: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:412: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:422: ERROR: do not use assignment in if condition
af_inet6.c:425: ERROR: do not use assignment in if condition
af_inet6.c:433: ERROR: do not use assignment in if condition
af_inet6.c:437: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:446: ERROR: spaces required around that '=' (ctx:VxV)
af_inet6.c:478: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:485: ERROR: that open brace { should be on the previous line
af_inet6.c:485: ERROR: space required before the open parenthesis '('
af_inet6.c:513: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:629: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:647: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:687: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:709: WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
af_inet6.c:1073: ERROR: space required before the open parenthesis '('
Signed-off-by: NEldad Zack <eldad@fogrefinery.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

According to the RFC4944 (Transmission of IPv6 Packets over
IEEE 802.15.4 Networks), chapter 7:

The IPv6 link-local address [RFC4291] for an IEEE 802.15.4 interface
is formed by appending the Interface Identifier, as defined above, to
the prefix FE80::/64.

  10 bits            54 bits                  64 bits
+----------+-----------------------+----------------------------+
|1111111010|         (zeros)       |    Interface Identifier    |
+----------+-----------------------+----------------------------+

This patch adds IPv6 address generation support for the 6lowpan
interfaces.
Signed-off-by: NAlexander Smirnov <alex.bluesman.smirnov@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the flags parameter to ipv6_find_hdr. This flags
allows us to:

* know if this is a fragment.
* stop at the AH header, so the information contained in that header
  can be used for some specific packet handling.

This patch also adds the offset parameter for inspection of one
inner IPv6 header that is contained in error messages.
Signed-off-by: NHans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

This patch removes ip_queue support which was marked as obsolete
years ago. The nfnetlink_queue modules provides more advanced
user-space packet queueing mechanism.

This patch also removes capability code included in SELinux that
refers to ip_queue. Otherwise, we break compilation.

Several warning has been sent regarding this to the mailing list
in the past month without anyone rising the hand to stop this
with some strong argument.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

It appears some networks play bad games with the two bits reserved for
ECN. This can trigger false congestion notifications and very slow
transferts.

Since RFC 3168 (6.1.1) forbids SYN packets to carry CT bits, we can
disable TCP ECN negociation if it happens we receive mangled CT bits in
the SYN packet.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Perry Lorier <perryl@google.com>
Cc: Matt Mathis <mattmathis@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Wilmer van der Gaast <wilmer@google.com>
Cc: Ankur Jain <jankur@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Dave Täht <dave.taht@bufferbloat.net>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For implementing other protocols on top of IPv6, such as L2TPv3's IP
encapsulation over ipv6, we'd like to call some IPv6 functions which
are not currently exported. This patch exports them.
Signed-off-by: NChris Elston <celston@katalix.com>
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that the sematics of udpv6_queue_rcv_skb() match IPv4's
udp_queue_rcv_skb(), introduce the UDP encap_rcv() hook for IPv6.
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to make sure that when the encap_rcv() hook is introduced it is
not called with the socket lock held, move socket locking from callers into
udpv6_queue_rcv_skb(), matching what happens in IPv4.
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is the first step in reworking the IPv6 UDP code to be structured more
like the IPv4 UDP code.  This patch creates __udpv6_queue_rcv_skb() with
the equivalent sematics to __udp_queue_rcv_skb(), and wires it up to the
backlog_rcv method.
Signed-off-by: NBenjamin LaHaise <bcrl@kvack.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Quoting Tore Anderson from :
https://bugzilla.kernel.org/show_bug.cgi?id=42572

When RTAX_FEATURE_ALLFRAG is set on a route, the effective TCP segment
size does not take into account the size of the IPv6 Fragmentation
header that needs to be included in outbound packets, causing every
transmitted TCP segment to be fragmented across two IPv6 packets, the
latter of which will only contain 8 bytes of actual payload.

RTAX_FEATURE_ALLFRAG is typically set on a route in response to
receving a ICMPv6 Packet Too Big message indicating a Path MTU of less
than 1280 bytes. 1280 bytes is the minimum IPv6 MTU, however ICMPv6
PTBs with MTU < 1280 are still valid, in particular when an IPv6
packet is sent to an IPv4 destination through a stateless translator.
Any ICMPv4 Need To Fragment packets originated from the IPv4 part of
the path will be translated to ICMPv6 PTB which may then indicate an
MTU of less than 1280.

The Linux kernel refuses to reduce the effective MTU to anything below
1280 bytes, instead it sets it to exactly 1280 bytes, and
RTAX_FEATURE_ALLFRAG is also set. However, the TCP segment size appears
to be set to 1240 bytes (1280 Path MTU - 40 bytes of IPv6 header),
instead of 1232 (additionally taking into account the 8 bytes required
by the IPv6 Fragmentation extension header).

This in turn results in rather inefficient transmission, as every
transmitted TCP segment now is split in two fragments containing
1232+8 bytes of payload.

After this patch, all the outgoing packets that includes a
Fragmentation header all are "atomic" or "non-fragmented" fragments,
i.e., they both have Offset=0 and More Fragments=0.

With help from David S. Miller
Reported-by: NTore Anderson <tore@fud.no>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Tom Herbert <therbert@google.com>
Tested-by: NTore Anderson <tore@fud.no>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some kfree_skb() calls should be replaced by consume_skb() to avoid
drop_monitor/dropwatch false positives.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While investigating TCP performance problems on 10Gb+ links, we found a
tcp sender was dropping lot of incoming ACKS because of sk_rcvbuf limit
in sk_add_backlog(), especially if receiver doesnt use GRO/LRO and sends
one ACK every two MSS segments.

A sender usually tweaks sk_sndbuf, but sk_rcvbuf stays at its default
value (87380), allowing a too small backlog.

A TCP ACK, even being small, can consume nearly same truesize space than
outgoing packets. Using sk_rcvbuf + sk_sndbuf as a limit makes sense and
is fast to compute.

Performance results on netperf, single flow, receiver with disabled
GRO/LRO : 7500 Mbits instead of 6050 Mbits, no more TCPBacklogDrop
increments at sender.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Rick Jones <rick.jones2@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sk_add_backlog() & sk_rcvqueues_full() hard coded sk_rcvbuf as the
memory limit. We need to make this limit a parameter for TCP use.

No functional change expected in this patch, all callers still using the
old sk_rcvbuf limit.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Cc: Rick Jones <rick.jones2@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/tcp_ipv4.c: In function 'tcp_v4_init_sock':
net/ipv4/tcp_ipv4.c:1891:19: warning: unused variable 'tp' [-Wunused-variable]
net/ipv6/tcp_ipv6.c: In function 'tcp_v6_init_sock':
net/ipv6/tcp_ipv6.c:1836:19: warning: unused variable 'tp' [-Wunused-variable]
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit f5fff5dc forgot to fix TCP_MAXSEG behavior IPv6 sockets, so IPv6
TCP server sockets that used TCP_MAXSEG would find that the advmss of
child sockets would be incorrect. This commit mirrors the advmss logic
from tcp_v4_syn_recv_sock in tcp_v6_syn_recv_sock. Eventually this
logic should probably be shared between IPv4 and IPv6, but this at
least fixes this issue.
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This commit moves the (substantial) common code shared between
tcp_v4_init_sock() and tcp_v6_init_sock() to a new address-family
independent function, tcp_init_sock().

Centralizing this functionality should help avoid drift issues,
e.g. where the IPv4 side is updated without a corresponding update to
IPv6. There was already some drift: IPv4 initialized snd_cwnd to
TCP_INIT_CWND, while the IPv6 side was still initializing snd_cwnd to
2 (in this case it should not matter, since snd_cwnd is also
initialized in tcp_init_metrics(), but the general risks and
maintenance overhead remain).

When diffing the old and new code, note that new tcp_init_sock()
function uses the order of steps from the tcp_v4_init_sock()
implementation (the order is slightly different in
tcp_v6_init_sock()).
Signed-off-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Name them in a "backward compatible" manner, i.e. reuse or not
are still 1 and 0 respectively. The reuse value of 2 means that
the socket with it will forcibly reuse everyone else's port.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>