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>

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>

As pointed out by Fernando Gont there is no need to encode rcv_wscale
into the cookie.

We did not use the restored rcv_wscale anyway; it is recomputed
via tcp_select_initial_window().

Thus we can save 4 bits in the ts option space by removing rcv_wscale.
In case window scaling was not supported, we set the (invalid) wscale
value 0xf.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In preparation for 64bit snmp counters for some mibs,
add an 'align' parameter to snmp_mib_init(), instead
of assuming mibs only contain 'unsigned long' fields.

Callers can use __alignof__(type) to provide correct
alignment.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
CC: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Avoid two atomic ops in arp_solicit()
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

i've found that tcp_close() can be called for an already closed
socket, but still sends reset in this case (tcp_send_active_reset())
which seems to be incorrect.  Moreover, a packet with reset is sent
with different source port as original port number has been already
cleared on socket.  Besides that incrementing stat counter for
LINUX_MIB_TCPABORTONCLOSE also does not look correct in this case.

Initially this issue was found on 2.6.18-x RHEL5 kernel, but the same
seems to be true for the current mainstream kernel (checked on
2.6.35-rc3).  Please, correct me if i missed something.

How that happens:

1) the server receives a packet for socket in TCP_CLOSE_WAIT state
   that triggers a tcp_reset():

Call Trace:
 <IRQ>  [<ffffffff8025b9b9>] tcp_reset+0x12f/0x1e8
 [<ffffffff80046125>] tcp_rcv_state_process+0x1c0/0xa08
 [<ffffffff8003eb22>] tcp_v4_do_rcv+0x310/0x37a
 [<ffffffff80028bea>] tcp_v4_rcv+0x74d/0xb43
 [<ffffffff8024ef4c>] ip_local_deliver_finish+0x0/0x259
 [<ffffffff80037131>] ip_local_deliver+0x200/0x2f4
 [<ffffffff8003843c>] ip_rcv+0x64c/0x69f
 [<ffffffff80021d89>] netif_receive_skb+0x4c4/0x4fa
 [<ffffffff80032eca>] process_backlog+0x90/0xec
 [<ffffffff8000cc50>] net_rx_action+0xbb/0x1f1
 [<ffffffff80012d3a>] __do_softirq+0xf5/0x1ce
 [<ffffffff8001147a>] handle_IRQ_event+0x56/0xb0
 [<ffffffff8006334c>] call_softirq+0x1c/0x28
 [<ffffffff80070476>] do_softirq+0x2c/0x85
 [<ffffffff80070441>] do_IRQ+0x149/0x152
 [<ffffffff80062665>] ret_from_intr+0x0/0xa
 <EOI>  [<ffffffff80008a2e>] __handle_mm_fault+0x6cd/0x1303
 [<ffffffff80008903>] __handle_mm_fault+0x5a2/0x1303
 [<ffffffff80033a9d>] cache_free_debugcheck+0x21f/0x22e
 [<ffffffff8006a263>] do_page_fault+0x49a/0x7dc
 [<ffffffff80066487>] thread_return+0x89/0x174
 [<ffffffff800c5aee>] audit_syscall_exit+0x341/0x35c
 [<ffffffff80062e39>] error_exit+0x0/0x84

tcp_rcv_state_process()
...  // (sk_state == TCP_CLOSE_WAIT here)
...
        /* step 2: check RST bit */
        if(th->rst) {
                tcp_reset(sk);
                goto discard;
        }
...
---------------------------------
tcp_rcv_state_process
 tcp_reset
  tcp_done
   tcp_set_state(sk, TCP_CLOSE);
     inet_put_port
      __inet_put_port
       inet_sk(sk)->num = 0;

   sk->sk_shutdown = SHUTDOWN_MASK;

2) After that the process (socket owner) tries to write something to
   that socket and "inet_autobind" sets a _new_ (which differs from
   the original!) port number for the socket:

 Call Trace:
  [<ffffffff80255a12>] inet_bind_hash+0x33/0x5f
  [<ffffffff80257180>] inet_csk_get_port+0x216/0x268
  [<ffffffff8026bcc9>] inet_autobind+0x22/0x8f
  [<ffffffff80049140>] inet_sendmsg+0x27/0x57
  [<ffffffff8003a9d9>] do_sock_write+0xae/0xea
  [<ffffffff80226ac7>] sock_writev+0xdc/0xf6
  [<ffffffff800680c7>] _spin_lock_irqsave+0x9/0xe
  [<ffffffff8001fb49>] __pollwait+0x0/0xdd
  [<ffffffff8008d533>] default_wake_function+0x0/0xe
  [<ffffffff800a4f10>] autoremove_wake_function+0x0/0x2e
  [<ffffffff800f0b49>] do_readv_writev+0x163/0x274
  [<ffffffff80066538>] thread_return+0x13a/0x174
  [<ffffffff800145d8>] tcp_poll+0x0/0x1c9
  [<ffffffff800c56d3>] audit_syscall_entry+0x180/0x1b3
  [<ffffffff800f0dd0>] sys_writev+0x49/0xe4
  [<ffffffff800622dd>] tracesys+0xd5/0xe0

3) sendmsg fails at last with -EPIPE (=> 'write' returns -EPIPE in userspace):

F: tcp_sendmsg1 -EPIPE: sk=ffff81000bda00d0, sport=49847, old_state=7, new_state=7, sk_err=0, sk_shutdown=3

Call Trace:
 [<ffffffff80027557>] tcp_sendmsg+0xcb/0xe87
 [<ffffffff80033300>] release_sock+0x10/0xae
 [<ffffffff8016f20f>] vgacon_cursor+0x0/0x1a7
 [<ffffffff8026bd32>] inet_autobind+0x8b/0x8f
 [<ffffffff8003a9d9>] do_sock_write+0xae/0xea
 [<ffffffff80226ac7>] sock_writev+0xdc/0xf6
 [<ffffffff800680c7>] _spin_lock_irqsave+0x9/0xe
 [<ffffffff8001fb49>] __pollwait+0x0/0xdd
 [<ffffffff8008d533>] default_wake_function+0x0/0xe
 [<ffffffff800a4f10>] autoremove_wake_function+0x0/0x2e
 [<ffffffff800f0b49>] do_readv_writev+0x163/0x274
 [<ffffffff80066538>] thread_return+0x13a/0x174
 [<ffffffff800145d8>] tcp_poll+0x0/0x1c9
 [<ffffffff800c56d3>] audit_syscall_entry+0x180/0x1b3
 [<ffffffff800f0dd0>] sys_writev+0x49/0xe4
 [<ffffffff800622dd>] tracesys+0xd5/0xe0

tcp_sendmsg()
...
        /* Wait for a connection to finish. */
        if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) {
                int old_state = sk->sk_state;
                if ((err = sk_stream_wait_connect(sk, &timeo)) != 0) {
if (f_d && (err == -EPIPE)) {
        printk("F: tcp_sendmsg1 -EPIPE: sk=%p, sport=%u, old_state=%d, new_state=%d, "
                "sk_err=%d, sk_shutdown=%d\n",
                sk, ntohs(inet_sk(sk)->sport), old_state, sk->sk_state,
                sk->sk_err, sk->sk_shutdown);
        dump_stack();
}
                        goto out_err;
                }
        }
...

4) Then the process (socket owner) understands that it's time to close
   that socket and does that (and thus triggers sending reset packet):

Call Trace:
...
 [<ffffffff80032077>] dev_queue_xmit+0x343/0x3d6
 [<ffffffff80034698>] ip_output+0x351/0x384
 [<ffffffff80251ae9>] dst_output+0x0/0xe
 [<ffffffff80036ec6>] ip_queue_xmit+0x567/0x5d2
 [<ffffffff80095700>] vprintk+0x21/0x33
 [<ffffffff800070f0>] check_poison_obj+0x2e/0x206
 [<ffffffff80013587>] poison_obj+0x36/0x45
 [<ffffffff8025dea6>] tcp_send_active_reset+0x15/0x14d
 [<ffffffff80023481>] dbg_redzone1+0x1c/0x25
 [<ffffffff8025dea6>] tcp_send_active_reset+0x15/0x14d
 [<ffffffff8000ca94>] cache_alloc_debugcheck_after+0x189/0x1c8
 [<ffffffff80023405>] tcp_transmit_skb+0x764/0x786
 [<ffffffff8025df8a>] tcp_send_active_reset+0xf9/0x14d
 [<ffffffff80258ff1>] tcp_close+0x39a/0x960
 [<ffffffff8026be12>] inet_release+0x69/0x80
 [<ffffffff80059b31>] sock_release+0x4f/0xcf
 [<ffffffff80059d4c>] sock_close+0x2c/0x30
 [<ffffffff800133c9>] __fput+0xac/0x197
 [<ffffffff800252bc>] filp_close+0x59/0x61
 [<ffffffff8001eff6>] sys_close+0x85/0xc7
 [<ffffffff800622dd>] tracesys+0xd5/0xe0

So, in brief:

* a received packet for socket in TCP_CLOSE_WAIT state triggers
  tcp_reset() which clears inet_sk(sk)->num and put socket into
  TCP_CLOSE state

* an attempt to write to that socket forces inet_autobind() to get a
  new port (but the write itself fails with -EPIPE)

* tcp_close() called for socket in TCP_CLOSE state sends an active
  reset via socket with newly allocated port

This adds an additional check in tcp_close() for already closed
sockets. We do not want to send anything to closed sockets.
Signed-off-by: NKonstantin Khorenko <khorenko@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

this patch is implementing IP_NODEFRAG option for IPv4 socket.
The reason is, there's no other way to send out the packet with user
customized header of the reassembly part.
Signed-off-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>