Create a new data structure for IPv4 protocols that holds GRO/GSO
callbacks and a new array to track the protocols that register GRO/GSO.
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert to using the new GSO/GRO registration mechanism and new
packet offload structure.
Signed-off-by: NVlad Yasevich <vyasevic@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NChristoph Paasch <christoph.paasch@uclouvain.be>
Acked-by: NH.K. Jerry Chu <hkchu@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fengguang Wu reported various panics and bisected to commit
8336886f (tcp: TCP Fast Open Server - support TFO listeners)

Fix this by making sure socket is a TCP socket before accessing TFO data
structures.

[  233.046014] kfree_debugcheck: out of range ptr ea6000000bb8h.
[  233.047399] ------------[ cut here ]------------
[  233.048393] kernel BUG at /c/kernel-tests/src/stable/mm/slab.c:3074!
[  233.048393] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[  233.048393] Modules linked in:
[  233.048393] CPU 0
[  233.048393] Pid: 3929, comm: trinity-watchdo Not tainted 3.6.0-rc3+
#4192 Bochs Bochs
[  233.048393] RIP: 0010:[<ffffffff81169653>]  [<ffffffff81169653>]
kfree_debugcheck+0x27/0x2d
[  233.048393] RSP: 0018:ffff88000facbca8  EFLAGS: 00010092
[  233.048393] RAX: 0000000000000031 RBX: 0000ea6000000bb8 RCX:
00000000a189a188
[  233.048393] RDX: 000000000000a189 RSI: ffffffff8108ad32 RDI:
ffffffff810d30f9
[  233.048393] RBP: ffff88000facbcb8 R08: 0000000000000002 R09:
ffffffff843846f0
[  233.048393] R10: ffffffff810ae37c R11: 0000000000000908 R12:
0000000000000202
[  233.048393] R13: ffffffff823dbd5a R14: ffff88000ec5bea8 R15:
ffffffff8363c780
[  233.048393] FS:  00007faa6899c700(0000) GS:ffff88001f200000(0000)
knlGS:0000000000000000
[  233.048393] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[  233.048393] CR2: 00007faa6841019c CR3: 0000000012c82000 CR4:
00000000000006f0
[  233.048393] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[  233.048393] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[  233.048393] Process trinity-watchdo (pid: 3929, threadinfo
ffff88000faca000, task ffff88000faec600)
[  233.048393] Stack:
[  233.048393]  0000000000000000 0000ea6000000bb8 ffff88000facbce8
ffffffff8116ad81
[  233.048393]  ffff88000ff588a0 ffff88000ff58850 ffff88000ff588a0
0000000000000000
[  233.048393]  ffff88000facbd08 ffffffff823dbd5a ffffffff823dbcb0
ffff88000ff58850
[  233.048393] Call Trace:
[  233.048393]  [<ffffffff8116ad81>] kfree+0x5f/0xca
[  233.048393]  [<ffffffff823dbd5a>] inet_sock_destruct+0xaa/0x13c
[  233.048393]  [<ffffffff823dbcb0>] ? inet_sk_rebuild_header
+0x319/0x319
[  233.048393]  [<ffffffff8231c307>] __sk_free+0x21/0x14b
[  233.048393]  [<ffffffff8231c4bd>] sk_free+0x26/0x2a
[  233.048393]  [<ffffffff825372db>] sctp_close+0x215/0x224
[  233.048393]  [<ffffffff810d6835>] ? lock_release+0x16f/0x1b9
[  233.048393]  [<ffffffff823daf12>] inet_release+0x7e/0x85
[  233.048393]  [<ffffffff82317d15>] sock_release+0x1f/0x77
[  233.048393]  [<ffffffff82317d94>] sock_close+0x27/0x2b
[  233.048393]  [<ffffffff81173bbe>] __fput+0x101/0x20a
[  233.048393]  [<ffffffff81173cd5>] ____fput+0xe/0x10
[  233.048393]  [<ffffffff810a3794>] task_work_run+0x5d/0x75
[  233.048393]  [<ffffffff8108da70>] do_exit+0x290/0x7f5
[  233.048393]  [<ffffffff82707415>] ? retint_swapgs+0x13/0x1b
[  233.048393]  [<ffffffff8108e23f>] do_group_exit+0x7b/0xba
[  233.048393]  [<ffffffff8108e295>] sys_exit_group+0x17/0x17
[  233.048393]  [<ffffffff8270de10>] tracesys+0xdd/0xe2
[  233.048393] Code: 59 01 5d c3 55 48 89 e5 53 41 50 0f 1f 44 00 00 48
89 fb e8 d4 b0 f0 ff 84 c0 75 11 48 89 de 48 c7 c7 fc fa f7 82 e8 0d 0f
57 01 <0f> 0b 5f 5b 5d c3 55 48 89 e5 0f 1f 44 00 00 48 63 87 d8 00 00
[  233.048393] RIP  [<ffffffff81169653>] kfree_debugcheck+0x27/0x2d
[  233.048393]  RSP <ffff88000facbca8>
Reported-by: NFengguang Wu <wfg@linux.intel.com>
Tested-by: NFengguang Wu <wfg@linux.intel.com>
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: "H.K. Jerry Chu" <hkchu@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NH.K. Jerry Chu <hkchu@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch builds on top of the previous patch to add the support
for TFO listeners. This includes -

1. allocating, properly initializing, and managing the per listener
fastopen_queue structure when TFO is enabled

2. changes to the inet_csk_accept code to support TFO. E.g., the
request_sock can no longer be freed upon accept(), not until 3WHS
finishes

3. allowing a TCP_SYN_RECV socket to properly poll() and sendmsg()
if it's a TFO socket

4. properly closing a TFO listener, and a TFO socket before 3WHS
finishes

5. supporting TCP_FASTOPEN socket option

6. modifying tcp_check_req() to use to check a TFO socket as well
as request_sock

7. supporting TCP's TFO cookie option

8. adding a new SYN-ACK retransmit handler to use the timer directly
off the TFO socket rather than the listener socket. Note that TFO
server side will not retransmit anything other than SYN-ACK until
the 3WHS is completed.

The patch also contains an important function
"reqsk_fastopen_remove()" to manage the somewhat complex relation
between a listener, its request_sock, and the corresponding child
socket. See the comment above the function for the detail.
Signed-off-by: NH.K. Jerry Chu <hkchu@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While doing TCP ECN tests, I discovered GRO was reordering packets if it
receives one packet with CE set, while previous packets in same NAPI run
have ECT(0) for the same flow :

09:25:25.857620 IP (tos 0x2,ECT(0), ttl 64, id 27893, offset 0, flags
[DF], proto TCP (6), length 4396)
    172.30.42.19.54550 > 172.30.42.13.44139: Flags [.], seq
233801:238145, ack 1, win 115, options [nop,nop,TS val 3397779 ecr
1990627], length 4344

09:25:25.857626 IP (tos 0x3,CE, ttl 64, id 27892, offset 0, flags [DF],
proto TCP (6), length 1500)
    172.30.42.19.54550 > 172.30.42.13.44139: Flags [.], seq
232353:233801, ack 1, win 115, options [nop,nop,TS val 3397779 ecr
1990627], length 1448

09:25:25.857638 IP (tos 0x0, ttl 64, id 34581, offset 0, flags [DF],
proto TCP (6), length 64)
    172.30.42.13.44139 > 172.30.42.19.54550: Flags [.], cksum 0xac8f
(incorrect -> 0xca69), ack 232353, win 1271, options [nop,nop,TS val
1990627 ecr 3397779,nop,nop,sack 1 {233801:238145}], length 0

We have two problems here :

1) GRO reorders packets

  If NIC gave packet1, then packet2, which happen to be from "different
flows"  GRO feeds stack with packet2, then packet1. I have yet to
understand how to solve this problem.

2) GRO is not ECN friendly

Delivering packets out of order makes TCP stack not as fast as it could
be.

In this patch I suggest we make the tos test not part of the 'same_flow'
determination, but part of the 'should flush' logic
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sendmsg() (or sendto()) with MSG_FASTOPEN is a combo of connect(2)
and write(2). The application should replace connect() with it to
send data in the opening SYN packet.

For blocking socket, sendmsg() blocks until all the data are buffered
locally and the handshake is completed like connect() call. It
returns similar errno like connect() if the TCP handshake fails.

For non-blocking socket, it returns the number of bytes queued (and
transmitted in the SYN-data packet) if cookie is available. If cookie
is not available, it transmits a data-less SYN packet with Fast Open
cookie request option and returns -EINPROGRESS like connect().

Using MSG_FASTOPEN on connecting or connected socket will result in
simlar errno like repeating connect() calls. Therefore the application
should only use this flag on new sockets.

The buffer size of sendmsg() is independent of the MSS of the connection.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements sending SYN-data in tcp_connect(). The data is
from tcp_sendmsg() with flag MSG_FASTOPEN (implemented in a later patch).

The length of the cookie in tcp_fastopen_req, init'd to 0, controls the
type of the SYN. If the cookie is not cached (len==0), the host sends
data-less SYN with Fast Open cookie request option to solicit a cookie
from the remote. If cookie is not available (len > 0), the host sends
a SYN-data with Fast Open cookie option. If cookie length is negative,
  the SYN will not include any Fast Open option (for fall back operations).

To deal with middleboxes that may drop SYN with data or experimental TCP
option, the SYN-data is only sent once. SYN retransmits do not include
data or Fast Open options. The connection will fall back to regular TCP
handshake.
Signed-off-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Input packet processing for local sockets involves two major demuxes.
One for the route and one for the socket.

But we can optimize this down to one demux for certain kinds of local
sockets.

Currently we only do this for established TCP sockets, but it could
at least in theory be expanded to other kinds of connections.

If a TCP socket is established then it's identity is fully specified.

This means that whatever input route was used during the three-way
handshake must work equally well for the rest of the connection since
the keys will not change.

Once we move to established state, we cache the receive packet's input
route to use later.

Like the existing cached route in sk->sk_dst_cache used for output
packets, we have to check for route invalidations using dst->obsolete
and dst->ops->check().

Early demux occurs outside of a socket locked section, so when a route
invalidation occurs we defer the fixup of sk->sk_rx_dst until we are
actually inside of established state packet processing and thus have
the socket locked.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Don't pretend that inet_protos[] and inet6_protos[] are hashes, thay
are just a straight arrays.  Remove all unnecessary hash masking.

Document MAX_INET_PROTOS.

Use RAW_HTABLE_SIZE when appropriate.
Reported-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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>

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>

Fix checkpatch errors of the following type:
	* ERROR: "foo * bar" should be "foo *bar"
	* ERROR: "(foo*)" should be "(foo *)"
Signed-off-by: NDaniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Add #define pr_fmt(fmt) as appropriate.

Add "IPv4: ", "TCP: ", and "IPsec: " to appropriate files.
Standardize on "UDPLite: " for appropriate uses.
Some prefixes were previously "UDPLITE: " and "UDP-Lite: ".

Add KBUILD_MODNAME ": " to icmp and gre.
Remove embedded prefixes as appropriate.

Add missing "\n" to pr_info in gre.c.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a more current kernel messaging style.

Convert a printk block to print_hex_dump.
Coalesce formats, align arguments.
Use %s, __func__ instead of embedding function names.

Some messages that were prefixed with <foo>_close are
now prefixed with <foo>_fini.  Some ah4 and esp messages
are now not prefixed with "ip ".

The intent of this patch is to later add something like
  #define pr_fmt(fmt) "IPv4: " fmt.
to standardize the output messages.

Text size is trivially reduced. (x86-32 allyesconfig)

$ size net/ipv4/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 887888	  31558	 249696	1169142	 11d6f6	net/ipv4/built-in.o.new
 887934	  31558	 249800	1169292	 11d78c	net/ipv4/built-in.o.old
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, it is not easily possible to get TOS/DSCP value of packets from
an incoming TCP stream. The mechanism is there, IP_PKTOPTIONS getsockopt
with IP_RECVTOS set, the same way as incoming TTL can be queried. This is
not actually implemented for TOS, though.

This patch adds this functionality, both for IPv4 (IP_PKTOPTIONS) and IPv6
(IPV6_2292PKTOPTIONS). For IPv4, like in the IP_RECVTTL case, the value of
the TOS field is stored from the other party's ACK.

This is needed for proxies which require DSCP transparency. One such example
is at http://zph.bratcheda.org/.
Signed-off-by: NJiri Benc <jbenc@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch allows each namespace to independently set up
its levels for tcp memory pressure thresholds. This patch
alone does not buy much: we need to make this values
per group of process somehow. This is achieved in the
patches that follows in this patchset.
Signed-off-by: NGlauber Costa <glommer@parallels.com>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
CC: David S. Miller <davem@davemloft.net>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

v2:	add couple missing conversions in drivers
	split unexporting netdev_fix_features()
	implemented %pNF
	convert sock::sk_route_(no?)caps
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Reading /proc/net/snmp on a machine with a lot of cpus is very expensive
(can be ~88000 us).

This is because ICMPMSG MIB uses 4096 bytes per cpu, and folding values
for all possible cpus can read 16 Mbytes of memory.

ICMP messages are not considered as fast path on a typical server, and
eventually few cpus handle them anyway. We can afford an atomic
operation instead of using percpu data.

This saves 4096 bytes per cpu and per network namespace.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ipv4: compat_ioctl is local to af_inet.c, make it static
Signed-off-by: NGerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit d0733d2e (Check for mistakenly passed in non-IPv4 address)
added regression on legacy apps that use bind() with AF_UNSPEC family.

Relax the check, but make sure the bind() is done on INADDR_ANY
addresses, as AF_UNSPEC has probably no sane meaning for other
addresses.

Bugzilla reference : https://bugzilla.kernel.org/show_bug.cgi?id=42012Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Reported-and-bisected-by: NRene Meier <r_meier@freenet.de>
CC: Marcus Meissner <meissner@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Hi,

Reinhard Max also pointed out that the error should EAFNOSUPPORT according
to POSIX.

The Linux manpages have it as EINVAL, some other OSes (Minix, HPUX, perhaps BSD) use
EAFNOSUPPORT. Windows uses WSAEFAULT according to MSDN.

Other protocols error values in their af bind() methods in current mainline git as far
as a brief look shows:
	EAFNOSUPPORT: atm, appletalk, l2tp, llc, phonet, rxrpc
	EINVAL: ax25, bluetooth, decnet, econet, ieee802154, iucv, netlink, netrom, packet, rds, rose, unix, x25,
	No check?: can/raw, ipv6/raw, irda, l2tp/l2tp_ip

Ciao, Marcus
Signed-off-by: NMarcus Meissner <meissner@suse.de>
Cc: Reinhard Max <max@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Le jeudi 16 juin 2011 à 23:38 -0400, David Miller a écrit :
> From: Ben Hutchings <bhutchings@solarflare.com>
> Date: Fri, 17 Jun 2011 00:50:46 +0100
>
> > On Wed, 2011-06-15 at 04:15 +0200, Eric Dumazet wrote:
> >> @@ -1594,6 +1594,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
> >>  			goto discard;
> >>
> >>  		if (nsk != sk) {
> >> +			sock_rps_save_rxhash(nsk, skb->rxhash);
> >>  			if (tcp_child_process(sk, nsk, skb)) {
> >>  				rsk = nsk;
> >>  				goto reset;
> >>
> >
> > I haven't tried this, but it looks reasonable to me.
> >
> > What about IPv6?  The logic in tcp_v6_do_rcv() looks very similar.
>
> Indeed ipv6 side needs the same fix.
>
> Eric please add that part and resubmit.  And in fact I might stick
> this into net-2.6 instead of net-next-2.6
>

OK, here is the net-2.6 based one then, thanks !

[PATCH v2] net: rfs: enable RFS before first data packet is received

First packet received on a passive tcp flow is not correctly RFS
steered.

One sock_rps_record_flow() call is missing in inet_accept()

But before that, we also must record rxhash when child socket is setup.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Tom Herbert <therbert@google.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: NDavid S. Miller <davem@conan.davemloft.net>

SNMP mibs use two percpu arrays, one used in BH context, another in USER
context. With increasing number of cpus in machines, and fact that ipv6
uses per network device ipstats_mib, this is consuming a lot of memory
if many network devices are registered.

commit be281e55 (ipv6: reduce per device ICMP mib sizes) shrinked
percpu needs for ipv6, but we can reduce memory use a bit more.

With recent percpu infrastructure (irqsafe_cpu_inc() ...), we no longer
need this BH/USER separation since we can update counters in a single
x86 instruction, regardless of the BH/USER context.

Other arches than x86 might need to disable irq in their
irqsafe_cpu_inc() implementation : If this happens to be a problem, we
can make SNMP_ARRAY_SZ arch dependent, but a previous poll
( https://lkml.org/lkml/2011/3/17/174 ) to arch maintainers did not
raise strong opposition.

Only on 32bit arches, we need to disable BH for 64bit counters updates
done from USER context (currently used for IP MIB)

This also reduces vmlinux size :

1) x86_64 build
$ size vmlinux.before vmlinux.after
   text	   data	    bss	    dec	    hex	filename
7853650	1293772	1896448	11043870	 a8841e	vmlinux.before
7850578	1293772	1896448	11040798	 a8781e	vmlinux.after

2) i386  build
$ size vmlinux.before vmlinux.afterpatch
   text	   data	    bss	    dec	    hex	filename
6039335	 635076	3670016	10344427	 9dd7eb	vmlinux.before
6037342	 635076	3670016	10342434	 9dd022	vmlinux.afterpatch
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Andi Kleen <andi@firstfloor.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: Tejun Heo <tj@kernel.org>
CC: Christoph Lameter <cl@linux-foundation.org>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org
CC: linux-arch@vger.kernel.org
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Check against mistakenly passing in IPv6 addresses (which would result
in an INADDR_ANY bind) or similar incompatible sockaddrs.
Signed-off-by: NMarcus Meissner <meissner@suse.de>
Cc: Reinhard Max <max@suse.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NVasiliy Kulikov <segoon@openwall.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These two functions must be invoked only when the socket is locked
(because socket identity modifications are made non-atomically).

Therefore we can use the cork flow for output route lookups.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that output route lookups update the flow with
source address selection, we can fetch it from
fl4->saddr instead of rt->rt_src
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We lack proper synchronization to manipulate inet->opt ip_options

Problem is ip_make_skb() calls ip_setup_cork() and
ip_setup_cork() possibly makes a copy of ipc->opt (struct ip_options),
without any protection against another thread manipulating inet->opt.

Another thread can change inet->opt pointer and free old one under us.

Use RCU to protect inet->opt (changed to inet->inet_opt).

Instead of handling atomic refcounts, just copy ip_options when
necessary, to avoid cache line dirtying.

We cant insert an rcu_head in struct ip_options since its included in
skb->cb[], so this patch is large because I had to introduce a new
ip_options_rcu structure.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

These functions are used together as a unit for route resolution
during connect().  They address the chicken-and-egg problem that
exists when ports need to be allocated during connect() processing,
yet such port allocations require addressing information from the
routing code.

It's currently more heavy handed than it needs to be, and in
particular we allocate and initialize a flow object twice.

Let the callers provide the on-stack flow object.  That way we only
need to initialize it once in the ip_route_connect() call.

Later, if ip_route_newports() needs to do anything, it re-uses that
flow object as-is except for the ports which it updates before the
route re-lookup.

Also, describe why this set of facilities are needed and how it works
in a big comment.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>

Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The idea here is this minimizes the number of places one has to edit
in order to make changes to how flows are defined and used.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of on the stack.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This boolean state is now available in the flow flags.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since that is what the current vague "flags" argument means.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since that's what the current vague "flags" thing means.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SIOCGETSGCNT is not a unique ioctl value as it it maps tio SIOCPROTOPRIVATE +1,
which unfortunately means the existing infrastructure for compat networking
ioctls is insufficient.  A trivial compact ioctl implementation would conflict
with:

SIOCAX25ADDUID
SIOCAIPXPRISLT
SIOCGETSGCNT_IN6
SIOCGETSGCNT
SIOCRSSCAUSE
SIOCX25SSUBSCRIP
SIOCX25SDTEFACILITIES

To make this work I have updated the compat_ioctl decode path to mirror the
the normal ioctl decode path.  I have added an ipv4 inet_compat_ioctl function
so that I can have ipv4 specific compat ioctls.   I have added a compat_ioctl
function into struct proto so I can break out ioctls by which kind of ip socket
I am using.  I have added a compat_raw_ioctl function because SIOCGETSGCNT only
works on raw sockets.  I have added a ipmr_compat_ioctl that mirrors the normal
ipmr_ioctl.

This was necessary because unfortunately the struct layout for the SIOCGETSGCNT
has unsigned longs in it so changes between 32bit and 64bit kernels.

This change was sufficient to run a 32bit ip multicast routing daemon on a
64bit kernel.
Reported-by: NBill Fenner <fenner@aristanetworks.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.

Occurences found by `grep -r` on net/, drivers/net, include/

[ Move features and vlan_features next to each other in
  struct netdev, as per Eric Dumazet's suggestion -DaveM ]
Signed-off-by: NMichał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>