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: NGlauber Costa <glommer@parallels.com>
Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com>
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch replaces all uses of struct sock fields' memory_pressure,
memory_allocated, sockets_allocated, and sysctl_mem to acessor
macros. Those macros can either receive a socket argument, or a mem_cgroup
argument, depending on the context they live in.

Since we're only doing a macro wrapping here, no performance impact at all is
expected in the case where we don't have cgroups disabled.
Signed-off-by: NGlauber Costa <glommer@parallels.com>
Reviewed-by: NHiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com>
CC: David S. Miller <davem@davemloft.net>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Instead of testing defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Wrap the udp6 lookup into the proper ifdef-s.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Eric Dumazet reported, that when inet_diag is built-in the udp_diag also goes
built-in and when ipv6 is a module the udp6 lookup symbol is not found.

  LD      .tmp_vmlinux1
net/built-in.o: In function `udp_dump_one':
udp_diag.c:(.text+0xa2b40): undefined reference to `__udp6_lib_lookup'
make: *** [.tmp_vmlinux1] Erreur 1

Fix this by making udp diag build mode depend on both -- inet diag and ipv6.
Reported-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Copy-s/tcp/udp/-paste from TCP bits.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do the same as TCP does -- iterate the given udp_table, filter
sockets with bytecode and dump sockets into reply message.

The same filtering as for TCP applies, though only some of the
state bits really matter.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Do the same as TCP does -- lookup a socket in the given udp_table,
check cookie, fill the reply message with existing inet socket dumping
helper and send one back.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce the transport level diag handler module for UDP (and UDP-lite)
sockets and register (empty for now) callbacks in the inet_diag module.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The UDP diag get_exact handler will require them to find a
socket by provided net, [sd]addr-s, [sd]ports and device.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce two callbacks in inet_diag_handler -- one for dumping all
sockets (with filters) and the other one for dumping a single sk.

Replace direct calls to icsk handlers with indirect calls to callbacks
provided by handlers.

Make existing TCP and DCCP handlers use provided helpers for icsk-s.

The UDP diag module will provide its own.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The existing inet_csk_diag_fill dumps the inet connection sock info
into the netlink inet_diag_message. Prepare this routine to be able
to dump only the inet_sock part of a socket if the icsk part is missing.

This will be used by UDP diag module when dumping UDP sockets.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The upcoming UDP module will require exactly this ability, so just
move the existing code to provide one.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to previous patch: the 1st part locks the inet handler
and will get generalized and the 2nd one dumps icsk-s and will
be used by TCP and DCCP handlers.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The 1st part locks the inet handler and the 2nd one dump the
inet connection sock.

In the next patches the 1st part will be generalized to call
the socket dumping routine indirectly (i.e. TCP/UDP/DCCP) and
the 2nd part will be used by TCP and DCCP handlers.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The netlink diag susbsys stores sk address bits in the nl message
as a "cookie" and uses one when dumps details about particular
socket.

The same will be required for udp diag module, so introduce a heler
in inet_diag module
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There's an info_size value stored on inet_diag_handler, but for existing
code this value is effectively constant, so just use sizeof(struct tcp_info)
where required.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch moves the sock_ code from inet_diag.c to generic sock_diag.c
file and provides necessary request_module-s calls and a pointer on
inet_diag_compat dumping routine.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now all the code works with sock_diag_req-compatible structs, so it's
possible to stop using the inet_diag_type2proto in inet_csk_diag_fill.
Pass the inet_diag_req into it and use the sdiag_protocol field. At the
same time remove the explicit ext argument, since it's also on the req.

However, this conversion is still required in _compat code, so just move
this routine, not remove.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The new API will specify family to work with. Teach the existing
socket walking code to bypass not interesting ones.

To preserve compatibility with existing behavior the _compat code
sets interesting family to AF_UNSPEC to dump them all.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make inet_diag_dumo work with given header instead of calculating
one from the nl message.

The SOCK_DIAG_BY_FAMILY just passes skb's one through, the compat code
converts the old header to new one.

Also fix the bytecode calculation to find one at proper offset.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Make inet_diag_get_exact work with given header instead of calculating
one from the nl message.

The SOCK_DIAG_BY_FAMILY just passes skb's one through, the compat code
converts the old header to new one.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This one coinsides with the sock_diag_req in the beginning and
contains only used fields from its previous analogue.

The existing code is patched to use the _compat version of it
for now.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When receiving the SOCK_DIAG_BY_FAMILY message we have to find the
handler for provided family and pass the nl message to it.

This patch describes an infrastructure to work with such nandlers
and implements stubs for AF_INET(6) ones.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sorry, but the vger didn't let this message go to the list. Re-sending it with
less spam-filter-prone subject.

When dumping the AF_INET/AF_INET6 sockets user will also specify the protocol,
so prepare the protocol diag handlers to work with IPPROTO_ constants.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current code calculates it at fixed offset. This offset will change, so
move the BC calculation upper to make the further patching simpler.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This type will run the family+protocol based socket dumping.
Also prepare the stub function for it.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ultimate goal is to get the sock_diag module, that works in
family+protocol terms. Currently this is suitable to do on the
inet_diag basis, so rename parts of the code. It will be moved
to sock_diag.c later.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use "IS_ENABLED(CONFIG_FOO)" macro instead of
"defined(CONFIG_FOO) || defined(CONFIG_FOO_MODULE)"
Signed-off-by: NIgor Maravic <igorm@etf.rs>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As mentioned by Joe Perches, TCP_OFF() and TCP_PAGE() macros are
useless.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

commit f07d960d (tcp: avoid frag allocation for small frames)
breaked assumption in tcp stack that skb is either linear (skb->data_len
== 0), or fully fragged (skb->data_len == skb->len)

tcp_trim_head() made this assumption, we must fix it.

Thanks to Vijay for providing a very detailed explanation.
Reported-by: NVijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To reflect the fact that a refrence is not obtained to the
resulting neighbour entry.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NRoland Dreier <roland@purestorage.com>

If ipv4_valdiate_peer() fails during a cached entry lookup,
we'll NULL derer since the loop iterator assumes rth is not
NULL.

Letting this be handled as a failure is just bogus, so just make it
not fail.  If we have trouble getting a non-NULL neighbour for the
redirected gateway, just restore the original gateway and continue.

The very next use of this cached route will try again.
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If our TCP_PAGE(sk) is not shared (page_count() == 1), we can set page
offset to 0.

This permits better filling of the pages on small to medium tcp writes.

"tbench 16" results on my dev server (2x4x2 machine) :

Before : 3072 MB/s
After  : 3146 MB/s  (2.4 % gain)
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We discovered that TCP stack could retransmit misaligned skbs if a
malicious peer acknowledged sub MSS frame. This currently can happen
only if output interface is non SG enabled : If SG is enabled, tcp
builds headless skbs (all payload is included in fragments), so the tcp
trimming process only removes parts of skb fragments, header stay
aligned.

Some arches cant handle misalignments, so force a head reallocation and
shrink headroom to MAX_TCP_HEADER.

Dont care about misaligments on x86 and PPC (or other arches setting
NET_IP_ALIGN to 0)

This patch introduces __pskb_copy() which can specify the headroom of
new head, and pskb_copy() becomes a wrapper on top of __pskb_copy()
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Denys Fedoryshchenko reported that SYN+FIN attacks were bringing his
linux machines to their limits.

Dont call conn_request() if the TCP flags includes SYN flag
Reported-by: NDenys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

__mkroute_output fails to work with the original tos
and uses value with stripped RTO_ONLINK bit. Make sure we put
the original TOS bits into rt_key_tos because it used to match
cached route.
Signed-off-by: NJulian Anastasov <ja@ssi.bg>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After reset ipv4_devconf->data[IPV4_DEVCONF_ACCEPT_LOCAL] to 0,
we should flush route cache, or it will continue receive packets with local
source address, which should be dropped.
Signed-off-by: NWeiping Pan <panweiping3@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit 81d54ec8.

If we take the "try_again" goto, due to a checksum error,
the 'len' has already been truncated.  So we won't compute
the same values as the original code did.
Reported-by: Npaul bilke <fsmail@conspiracy.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>