Commit Graph

35 Commits

Author SHA1 Message Date
Guillaume Nault 43f8c8b058 l2tp: take reference on sessions being dumped
commit e08293a4ccbcc993ded0fdc46f1e57926b833d63 upstream.

Take a reference on the sessions returned by l2tp_session_find_nth()
(and rename it l2tp_session_get_nth() to reflect this change), so that
caller is assured that the session isn't going to disappear while
processing it.

For procfs and debugfs handlers, the session is held in the .start()
callback and dropped in .show(). Given that pppol2tp_seq_session_show()
dereferences the associated PPPoL2TP socket and that
l2tp_dfs_seq_session_show() might call pppol2tp_show(), we also need to
call the session's .ref() callback to prevent the socket from going
away from under us.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Fixes: 0ad6614048 ("l2tp: Add debugfs files for dumping l2tp debug info")
Fixes: 309795f4be ("l2tp: Add netlink control API for L2TP")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: Willy Tarreau <w@1wt.eu>
2017-06-08 00:47:08 +02:00
Guillaume Nault 696c5d5f34 l2tp: fix race while getting PMTU on PPP pseudo-wire
[ Upstream commit eed4d839b0cdf9d84b0a9bc63de90fd5e1e886fb ]

Use dst_entry held by sk_dst_get() to retrieve tunnel's PMTU.

The dst_mtu(__sk_dst_get(tunnel->sock)) call was racy. __sk_dst_get()
could return NULL if tunnel->sock->sk_dst_cache was reset just before the
call, thus making dst_mtu() dereference a NULL pointer:

[ 1937.661598] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
[ 1937.664005] IP: [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
[ 1937.664005] PGD daf0c067 PUD d9f93067 PMD 0
[ 1937.664005] Oops: 0000 [#1] SMP
[ 1937.664005] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core ip6table_filter ip6_tables iptable_filter ip_tables ebtable_nat ebtables x_tables udp_tunnel pppoe pppox ppp_generic slhc deflate ctr twofish_generic twofish_x86_64_3way xts lrw gf128mul glue_helper twofish_x86_64 twofish_common blowfish_generic blowfish_x86_64 blowfish_common des_generic cbc xcbc rmd160 sha512_generic hmac crypto_null af_key xfrm_algo 8021q garp bridge stp llc tun atmtcp clip atm ext3 mbcache jbd iTCO_wdt coretemp kvm_intel iTCO_vendor_support kvm pcspkr evdev ehci_pci lpc_ich mfd_core i5400_edac edac_core i5k_amb shpchp button processor thermal_sys xfs crc32c_generic libcrc32c dm_mod usbhid sg hid sr_mod sd_mod cdrom crc_t10dif crct10dif_common ata_generic ahci ata_piix tg3 libahci libata uhci_hcd ptp ehci_hcd pps_core usbcore scsi_mod libphy usb_common [last unloaded: l2tp_core]
[ 1937.664005] CPU: 0 PID: 10022 Comm: l2tpstress Tainted: G           O   3.17.0-rc1 #1
[ 1937.664005] Hardware name: HP ProLiant DL160 G5, BIOS O12 08/22/2008
[ 1937.664005] task: ffff8800d8fda790 ti: ffff8800c43c4000 task.ti: ffff8800c43c4000
[ 1937.664005] RIP: 0010:[<ffffffffa049db88>]  [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
[ 1937.664005] RSP: 0018:ffff8800c43c7de8  EFLAGS: 00010282
[ 1937.664005] RAX: ffff8800da8a7240 RBX: ffff8800d8c64600 RCX: 000001c325a137b5
[ 1937.664005] RDX: 8c6318c6318c6320 RSI: 000000000000010c RDI: 0000000000000000
[ 1937.664005] RBP: ffff8800c43c7ea8 R08: 0000000000000000 R09: 0000000000000000
[ 1937.664005] R10: ffffffffa048e2c0 R11: ffff8800d8c64600 R12: ffff8800ca7a5000
[ 1937.664005] R13: ffff8800c439bf40 R14: 000000000000000c R15: 0000000000000009
[ 1937.664005] FS:  00007fd7f610f700(0000) GS:ffff88011a600000(0000) knlGS:0000000000000000
[ 1937.664005] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1937.664005] CR2: 0000000000000020 CR3: 00000000d9d75000 CR4: 00000000000027e0
[ 1937.664005] Stack:
[ 1937.664005]  ffffffffa049da80 ffff8800d8fda790 000000000000005b ffff880000000009
[ 1937.664005]  ffff8800daf3f200 0000000000000003 ffff8800c43c7e48 ffffffff81109b57
[ 1937.664005]  ffffffff81109b0e ffffffff8114c566 0000000000000000 0000000000000000
[ 1937.664005] Call Trace:
[ 1937.664005]  [<ffffffffa049da80>] ? pppol2tp_connect+0x235/0x41e [l2tp_ppp]
[ 1937.664005]  [<ffffffff81109b57>] ? might_fault+0x9e/0xa5
[ 1937.664005]  [<ffffffff81109b0e>] ? might_fault+0x55/0xa5
[ 1937.664005]  [<ffffffff8114c566>] ? rcu_read_unlock+0x1c/0x26
[ 1937.664005]  [<ffffffff81309196>] SYSC_connect+0x87/0xb1
[ 1937.664005]  [<ffffffff813e56f7>] ? sysret_check+0x1b/0x56
[ 1937.664005]  [<ffffffff8107590d>] ? trace_hardirqs_on_caller+0x145/0x1a1
[ 1937.664005]  [<ffffffff81213dee>] ? trace_hardirqs_on_thunk+0x3a/0x3f
[ 1937.664005]  [<ffffffff8114c262>] ? spin_lock+0x9/0xb
[ 1937.664005]  [<ffffffff813092b4>] SyS_connect+0x9/0xb
[ 1937.664005]  [<ffffffff813e56d2>] system_call_fastpath+0x16/0x1b
[ 1937.664005] Code: 10 2a 84 81 e8 65 76 bd e0 65 ff 0c 25 10 bb 00 00 4d 85 ed 74 37 48 8b 85 60 ff ff ff 48 8b 80 88 01 00 00 48 8b b8 10 02 00 00 <48> 8b 47 20 ff 50 20 85 c0 74 0f 83 e8 28 89 83 10 01 00 00 89
[ 1937.664005] RIP  [<ffffffffa049db88>] pppol2tp_connect+0x33d/0x41e [l2tp_ppp]
[ 1937.664005]  RSP <ffff8800c43c7de8>
[ 1937.664005] CR2: 0000000000000020
[ 1939.559375] ---[ end trace 82d44500f28f8708 ]---

Fixes: f34c4a35d879 ("l2tp: take PMTU from tunnel UDP socket")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-10-15 08:31:57 +02:00
Sasha Levin 6718de2340 net/l2tp: don't fall back on UDP [get|set]sockopt
commit 3cf521f7dc87c031617fd47e4b7aa2593c2f3daf upstream.

The l2tp [get|set]sockopt() code has fallen back to the UDP functions
for socket option levels != SOL_PPPOL2TP since day one, but that has
never actually worked, since the l2tp socket isn't an inet socket.

As David Miller points out:

  "If we wanted this to work, it'd have to look up the tunnel and then
   use tunnel->sk, but I wonder how useful that would be"

Since this can never have worked so nobody could possibly have depended
on that functionality, just remove the broken code and return -EINVAL.

Reported-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: James Chapman <jchapman@katalix.com>
Acked-by: David Miller <davem@davemloft.net>
Cc: Phil Turnbull <phil.turnbull@oracle.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-08-07 14:30:27 -07:00
Dmitry Petukhov 6ea4dd539a l2tp: take PMTU from tunnel UDP socket
[ Upstream commit f34c4a35d87949fbb0e0f31eba3c054e9f8199ba ]

When l2tp driver tries to get PMTU for the tunnel destination, it uses
the pointer to struct sock that represents PPPoX socket, while it
should use the pointer that represents UDP socket of the tunnel.

Signed-off-by: Dmitry Petukhov <dmgenp@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-30 21:52:14 -07:00
Hannes Frederic Sowa 2f73d7fde9 net: rework recvmsg handler msg_name and msg_namelen logic
[ Upstream commit f3d3342602f8bcbf37d7c46641cb9bca7618eb1c ]

This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.

This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.

Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.

Also document these changes in include/linux/net.h as suggested by David
Miller.

Changes since RFC:

Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.

With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
	msg->msg_name = NULL
".

This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.

Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.

Cc: David Miller <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-08 07:29:25 -08:00
Eric Dumazet a41536775e l2tp: must disable bh before calling l2tp_xmit_skb()
[ Upstream commit 455cc32bf128e114455d11ad919321ab89a2c312 ]

François Cachereul made a very nice bug report and suspected
the bh_lock_sock() / bh_unlok_sock() pair used in l2tp_xmit_skb() from
process context was not good.

This problem was added by commit 6af88da14e
("l2tp: Fix locking in l2tp_core.c").

l2tp_eth_dev_xmit() runs from BH context, so we must disable BH
from other l2tp_xmit_skb() users.

[  452.060011] BUG: soft lockup - CPU#1 stuck for 23s! [accel-pppd:6662]
[  452.061757] Modules linked in: l2tp_ppp l2tp_netlink l2tp_core pppoe pppox
ppp_generic slhc ipv6 ext3 mbcache jbd virtio_balloon xfs exportfs dm_mod
virtio_blk ata_generic virtio_net floppy ata_piix libata virtio_pci virtio_ring virtio [last unloaded: scsi_wait_scan]
[  452.064012] CPU 1
[  452.080015] BUG: soft lockup - CPU#2 stuck for 23s! [accel-pppd:6643]
[  452.080015] CPU 2
[  452.080015]
[  452.080015] Pid: 6643, comm: accel-pppd Not tainted 3.2.46.mini #1 Bochs Bochs
[  452.080015] RIP: 0010:[<ffffffff81059f6c>]  [<ffffffff81059f6c>] do_raw_spin_lock+0x17/0x1f
[  452.080015] RSP: 0018:ffff88007125fc18  EFLAGS: 00000293
[  452.080015] RAX: 000000000000aba9 RBX: ffffffff811d0703 RCX: 0000000000000000
[  452.080015] RDX: 00000000000000ab RSI: ffff8800711f6896 RDI: ffff8800745c8110
[  452.080015] RBP: ffff88007125fc18 R08: 0000000000000020 R09: 0000000000000000
[  452.080015] R10: 0000000000000000 R11: 0000000000000280 R12: 0000000000000286
[  452.080015] R13: 0000000000000020 R14: 0000000000000240 R15: 0000000000000000
[  452.080015] FS:  00007fdc0cc24700(0000) GS:ffff8800b6f00000(0000) knlGS:0000000000000000
[  452.080015] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  452.080015] CR2: 00007fdb054899b8 CR3: 0000000074404000 CR4: 00000000000006a0
[  452.080015] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  452.080015] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  452.080015] Process accel-pppd (pid: 6643, threadinfo ffff88007125e000, task ffff8800b27e6dd0)
[  452.080015] Stack:
[  452.080015]  ffff88007125fc28 ffffffff81256559 ffff88007125fc98 ffffffffa01b2bd1
[  452.080015]  ffff88007125fc58 000000000000000c 00000000029490d0 0000009c71dbe25e
[  452.080015]  000000000000005c 000000080000000e 0000000000000000 ffff880071170600
[  452.080015] Call Trace:
[  452.080015]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.080015]  [<ffffffffa01b2bd1>] l2tp_xmit_skb+0x189/0x4ac [l2tp_core]
[  452.080015]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.080015]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.080015]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.080015]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.080015]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.080015]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.080015]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.080015]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.080015]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.080015] Code: 81 48 89 e5 72 0c 31 c0 48 81 ff 45 66 25 81 0f 92 c0 5d c3 55 b8 00 01 00 00 48 89 e5 f0 66 0f c1 07 0f b6 d4 38 d0 74 06 f3 90 <8a> 07 eb f6 5d c3 90 90 55 48 89 e5 9c 58 0f 1f 44 00 00 5d c3
[  452.080015] Call Trace:
[  452.080015]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.080015]  [<ffffffffa01b2bd1>] l2tp_xmit_skb+0x189/0x4ac [l2tp_core]
[  452.080015]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.080015]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.080015]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.080015]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.080015]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.080015]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.080015]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.080015]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.080015]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.064012]
[  452.064012] Pid: 6662, comm: accel-pppd Not tainted 3.2.46.mini #1 Bochs Bochs
[  452.064012] RIP: 0010:[<ffffffff81059f6e>]  [<ffffffff81059f6e>] do_raw_spin_lock+0x19/0x1f
[  452.064012] RSP: 0018:ffff8800b6e83ba0  EFLAGS: 00000297
[  452.064012] RAX: 000000000000aaa9 RBX: ffff8800b6e83b40 RCX: 0000000000000002
[  452.064012] RDX: 00000000000000aa RSI: 000000000000000a RDI: ffff8800745c8110
[  452.064012] RBP: ffff8800b6e83ba0 R08: 000000000000c802 R09: 000000000000001c
[  452.064012] R10: ffff880071096c4e R11: 0000000000000006 R12: ffff8800b6e83b18
[  452.064012] R13: ffffffff8125d51e R14: ffff8800b6e83ba0 R15: ffff880072a589c0
[  452.064012] FS:  00007fdc0b81e700(0000) GS:ffff8800b6e80000(0000) knlGS:0000000000000000
[  452.064012] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  452.064012] CR2: 0000000000625208 CR3: 0000000074404000 CR4: 00000000000006a0
[  452.064012] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  452.064012] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[  452.064012] Process accel-pppd (pid: 6662, threadinfo ffff88007129a000, task ffff8800744f7410)
[  452.064012] Stack:
[  452.064012]  ffff8800b6e83bb0 ffffffff81256559 ffff8800b6e83bc0 ffffffff8121c64a
[  452.064012]  ffff8800b6e83bf0 ffffffff8121ec7a ffff880072a589c0 ffff880071096c62
[  452.064012]  0000000000000011 ffffffff81430024 ffff8800b6e83c80 ffffffff8121f276
[  452.064012] Call Trace:
[  452.064012]  <IRQ>
[  452.064012]  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8121c64a>] spin_lock+0x9/0xb
[  452.064012]  [<ffffffff8121ec7a>] udp_queue_rcv_skb+0x186/0x269
[  452.064012]  [<ffffffff8121f276>] __udp4_lib_rcv+0x297/0x4ae
[  452.064012]  [<ffffffff8121c178>] ? raw_rcv+0xe9/0xf0
[  452.064012]  [<ffffffff8121f4a7>] udp_rcv+0x1a/0x1c
[  452.064012]  [<ffffffff811fe385>] ip_local_deliver_finish+0x12b/0x1a5
[  452.064012]  [<ffffffff811fe54e>] ip_local_deliver+0x53/0x84
[  452.064012]  [<ffffffff811fe1d0>] ip_rcv_finish+0x2bc/0x2f3
[  452.064012]  [<ffffffff811fe78f>] ip_rcv+0x210/0x269
[  452.064012]  [<ffffffff8101911e>] ? kvm_clock_get_cycles+0x9/0xb
[  452.064012]  [<ffffffff811d88cd>] __netif_receive_skb+0x3a5/0x3f7
[  452.064012]  [<ffffffff811d8eba>] netif_receive_skb+0x57/0x5e
[  452.064012]  [<ffffffff811cf30f>] ? __netdev_alloc_skb+0x1f/0x3b
[  452.064012]  [<ffffffffa0049126>] virtnet_poll+0x4ba/0x5a4 [virtio_net]
[  452.064012]  [<ffffffff811d9417>] net_rx_action+0x73/0x184
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffff810343b9>] __do_softirq+0xc3/0x1a8
[  452.064012]  [<ffffffff81013b56>] ? ack_APIC_irq+0x10/0x12
[  452.064012]  [<ffffffff81256559>] ? _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8125e0ac>] call_softirq+0x1c/0x26
[  452.064012]  [<ffffffff81003587>] do_softirq+0x45/0x82
[  452.064012]  [<ffffffff81034667>] irq_exit+0x42/0x9c
[  452.064012]  [<ffffffff8125e146>] do_IRQ+0x8e/0xa5
[  452.064012]  [<ffffffff8125676e>] common_interrupt+0x6e/0x6e
[  452.064012]  <EOI>
[  452.064012]  [<ffffffff810b82a1>] ? kfree+0x8a/0xa3
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01b2c25>] ? l2tp_xmit_skb+0x1dd/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.064012]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.064012]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.064012]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.064012]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.064012]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.064012]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.064012]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.064012]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b
[  452.064012] Code: 89 e5 72 0c 31 c0 48 81 ff 45 66 25 81 0f 92 c0 5d c3 55 b8 00 01 00 00 48 89 e5 f0 66 0f c1 07 0f b6 d4 38 d0 74 06 f3 90 8a 07 <eb> f6 5d c3 90 90 55 48 89 e5 9c 58 0f 1f 44 00 00 5d c3 55 48
[  452.064012] Call Trace:
[  452.064012]  <IRQ>  [<ffffffff81256559>] _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8121c64a>] spin_lock+0x9/0xb
[  452.064012]  [<ffffffff8121ec7a>] udp_queue_rcv_skb+0x186/0x269
[  452.064012]  [<ffffffff8121f276>] __udp4_lib_rcv+0x297/0x4ae
[  452.064012]  [<ffffffff8121c178>] ? raw_rcv+0xe9/0xf0
[  452.064012]  [<ffffffff8121f4a7>] udp_rcv+0x1a/0x1c
[  452.064012]  [<ffffffff811fe385>] ip_local_deliver_finish+0x12b/0x1a5
[  452.064012]  [<ffffffff811fe54e>] ip_local_deliver+0x53/0x84
[  452.064012]  [<ffffffff811fe1d0>] ip_rcv_finish+0x2bc/0x2f3
[  452.064012]  [<ffffffff811fe78f>] ip_rcv+0x210/0x269
[  452.064012]  [<ffffffff8101911e>] ? kvm_clock_get_cycles+0x9/0xb
[  452.064012]  [<ffffffff811d88cd>] __netif_receive_skb+0x3a5/0x3f7
[  452.064012]  [<ffffffff811d8eba>] netif_receive_skb+0x57/0x5e
[  452.064012]  [<ffffffff811cf30f>] ? __netdev_alloc_skb+0x1f/0x3b
[  452.064012]  [<ffffffffa0049126>] virtnet_poll+0x4ba/0x5a4 [virtio_net]
[  452.064012]  [<ffffffff811d9417>] net_rx_action+0x73/0x184
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffff810343b9>] __do_softirq+0xc3/0x1a8
[  452.064012]  [<ffffffff81013b56>] ? ack_APIC_irq+0x10/0x12
[  452.064012]  [<ffffffff81256559>] ? _raw_spin_lock+0xe/0x10
[  452.064012]  [<ffffffff8125e0ac>] call_softirq+0x1c/0x26
[  452.064012]  [<ffffffff81003587>] do_softirq+0x45/0x82
[  452.064012]  [<ffffffff81034667>] irq_exit+0x42/0x9c
[  452.064012]  [<ffffffff8125e146>] do_IRQ+0x8e/0xa5
[  452.064012]  [<ffffffff8125676e>] common_interrupt+0x6e/0x6e
[  452.064012]  <EOI>  [<ffffffff810b82a1>] ? kfree+0x8a/0xa3
[  452.064012]  [<ffffffffa01b2cc2>] ? l2tp_xmit_skb+0x27a/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01b2c25>] ? l2tp_xmit_skb+0x1dd/0x4ac [l2tp_core]
[  452.064012]  [<ffffffffa01c2d36>] pppol2tp_sendmsg+0x15e/0x19c [l2tp_ppp]
[  452.064012]  [<ffffffff811c7872>] __sock_sendmsg_nosec+0x22/0x24
[  452.064012]  [<ffffffff811c83bd>] sock_sendmsg+0xa1/0xb6
[  452.064012]  [<ffffffff81254e88>] ? __schedule+0x5c1/0x616
[  452.064012]  [<ffffffff8103c7c6>] ? __dequeue_signal+0xb7/0x10c
[  452.064012]  [<ffffffff810bbd21>] ? fget_light+0x75/0x89
[  452.064012]  [<ffffffff811c8444>] ? sockfd_lookup_light+0x20/0x56
[  452.064012]  [<ffffffff811c9b34>] sys_sendto+0x10c/0x13b
[  452.064012]  [<ffffffff8125cac2>] system_call_fastpath+0x16/0x1b

Reported-by: François Cachereul <f.cachereul@alphalink.fr>
Tested-by: François Cachereul <f.cachereul@alphalink.fr>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-04 04:31:02 -08:00
Wei Yongjun ed7f614ab8 l2tp: add missing .owner to struct pppox_proto
[ Upstream commit e1558a93b61962710733dc8c11a2bc765607f1cd ]

Add missing .owner of struct pppox_proto. This prevents the
module from being removed from underneath its users.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-28 16:29:49 -07:00
Guillaume Nault a6f79d0f26 l2tp: Fix sendmsg() return value
PPPoL2TP sockets should comply with the standard send*() return values
(i.e. return number of bytes sent instead of 0 upon success).

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-13 02:39:04 -07:00
Guillaume Nault 55b92b7a11 l2tp: Fix PPP header erasure and memory leak
Copy user data after PPP framing header. This prevents erasure of the
added PPP header and avoids leaking two bytes of uninitialised memory
at the end of skb's data buffer.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-13 02:39:04 -07:00
Tom Parkin f6e16b299b l2tp: unhash l2tp sessions on delete, not on free
If we postpone unhashing of l2tp sessions until the structure is freed, we
risk:

 1. further packets arriving and getting queued while the pseudowire is being
    closed down
 2. the recv path hitting "scheduling while atomic" errors in the case that
    recv drops the last reference to a session and calls l2tp_session_free
    while in atomic context

As such, l2tp sessions should be unhashed from l2tp_core data structures early
in the teardown process prior to calling pseudowire close.  For pseudowires
like l2tp_ppp which have multiple shutdown codepaths, provide an unhash hook.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20 12:10:39 -04:00
Tom Parkin 7b7c0719cd l2tp: avoid deadlock in l2tp stats update
l2tp's u64_stats writers were incorrectly synchronised, making it possible to
deadlock a 64bit machine running a 32bit kernel simply by sending the l2tp
code netlink commands while passing data through l2tp sessions.

Previous discussion on netdev determined that alternative solutions such as
spinlock writer synchronisation or per-cpu data would bring unjustified
overhead, given that most users interested in high volume traffic will likely
be running 64bit kernels on 64bit hardware.

As such, this patch replaces l2tp's use of u64_stats with atomic_long_t,
thereby avoiding the deadlock.

Ref:
http://marc.info/?l=linux-netdev&m=134029167910731&w=2
http://marc.info/?l=linux-netdev&m=134079868111131&w=2

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20 12:10:39 -04:00
Tom Parkin cf2f5c886a l2tp: push all ppp pseudowire shutdown through .release handler
If userspace deletes a ppp pseudowire using the netlink API, either by
directly deleting the session or by deleting the tunnel that contains the
session, we need to tear down the corresponding pppox channel.

Rather than trying to manage two pppox unbind codepaths, switch the netlink
and l2tp_core session_close handlers to close via. the l2tp_ppp socket
.release handler.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-20 12:10:39 -04:00
Guillaume Nault 8b82547e33 l2tp: Restore socket refcount when sendmsg succeeds
The sendmsg() syscall handler for PPPoL2TP doesn't decrease the socket
reference counter after successful transmissions. Any successful
sendmsg() call from userspace will then increase the reference counter
forever, thus preventing the kernel's session and tunnel data from
being freed later on.

The problem only happens when writing directly on L2TP sockets.
PPP sockets attached to L2TP are unaffected as the PPP subsystem
uses pppol2tp_xmit() which symmetrically increase/decrease reference
counters.

This patch adds the missing call to sock_put() before returning from
pppol2tp_sendmsg().

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-01 14:13:09 -05:00
Gao feng ece31ffd53 net: proc: change proc_net_remove to remove_proc_entry
proc_net_remove is only used to remove proc entries
that under /proc/net,it's not a general function for
removing proc entries of netns. if we want to remove
some proc entries which under /proc/net/stat/, we still
need to call remove_proc_entry.

this patch use remove_proc_entry to replace proc_net_remove.
we can remove proc_net_remove after this patch.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 14:53:08 -05:00
Gao feng d4beaa66ad net: proc: change proc_net_fops_create to proc_create
Right now, some modules such as bonding use proc_create
to create proc entries under /proc/net/, and other modules
such as ipv4 use proc_net_fops_create.

It looks a little chaos.this patch changes all of
proc_net_fops_create to proc_create. we can remove
proc_net_fops_create after this patch.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 14:53:08 -05:00
Eric Dumazet 87c084a980 l2tp: dont play with skb->truesize
Andrew Savchenko reported a DNS failure and we diagnosed that
some UDP sockets were unable to send more packets because their
sk_wmem_alloc was corrupted after a while (tx_queue column in
following trace)

$ cat /proc/net/udp
  sl  local_address rem_address   st tx_queue rx_queue tr tm->when retrnsmt   uid  timeout inode ref pointer drops
...
  459: 00000000:0270 00000000:0000 07 00000000:00000000 00:00000000 00000000     0        0 4507 2 ffff88003d612380 0
  466: 00000000:0277 00000000:0000 07 00000000:00000000 00:00000000 00000000     0        0 4802 2 ffff88003d613180 0
  470: 076A070A:007B 00000000:0000 07 FFFF4600:00000000 00:00000000 00000000   123        0 5552 2 ffff880039974380 0
  470: 010213AC:007B 00000000:0000 07 00000000:00000000 00:00000000 00000000     0        0 4986 2 ffff88003dbd3180 0
  470: 010013AC:007B 00000000:0000 07 00000000:00000000 00:00000000 00000000     0        0 4985 2 ffff88003dbd2e00 0
  470: 00FCA8C0:007B 00000000:0000 07 FFFFFB00:00000000 00:00000000 00000000     0        0 4984 2 ffff88003dbd2a80 0
...

Playing with skb->truesize is tricky, especially when
skb is attached to a socket, as we can fool memory charging.

Just remove this code, its not worth trying to be ultra
precise in xmit path.

Reported-by: Andrew Savchenko <bircoph@gmail.com>
Tested-by: Andrew Savchenko <bircoph@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-08 01:49:49 -05:00
Joe Perches e3192690a3 net: Remove casts to same type
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: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-04 11:45:11 -04:00
Joe Perches a4ca44fa57 net: l2tp: Standardize logging styles
Use more current logging styles.

Add pr_fmt to prefix output appropriately.
Convert printks to pr_<level>.
Convert PRINTK macros to new l2tp_<level> macros.
Neaten some <foo>_refcount debugging macros.
Use print_hex_dump_bytes instead of hand-coded loops.
Coalesce formats and align arguments.

Some KERN_DEBUG output is not now emitted unless
dynamic_debugging is enabled.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-17 04:34:38 -04:00
James Chapman b79585f537 l2tp: pppol2tp_connect() handles ipv6 sockaddr variants
Userspace uses connect() to associate a pppol2tp socket with a tunnel
socket. This needs to allow the caller to supply the new IPv6
sockaddr_pppol2tp structures if IPv6 is used.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01 09:30:55 -04:00
Benjamin LaHaise d2cf336167 net/l2tp: add support for L2TP over IPv6 UDP
Now that encap_rcv() works on IPv6 UDP sockets, wire L2TP up to IPv6.
Support has been tested with and without hardware offloading.  This
version fixes the L2TP over localhost issue with incorrect checksums
being reported.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-28 22:21:51 -04:00
Benjamin LaHaise 9395a09d05 l2tp: enable automatic module loading for l2tp_ppp
When L2TP is configured as a module, requests for L2TP sockets do not result
in the l2tp_ppp module being loaded.  Fix this by adding the appropriate
MODULE_ALIAS to be recognized by pppox's request_module() call.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-21 22:14:56 -04:00
Benjamin LaHaise bbdb32cb5b Fix pppol2tp getsockname()
While testing L2TP functionality, I came across a bug in getsockname().  The
IP address returned within the pppol2tp_addr's addr memember was not being
set to the IP  address in use.  This bug is caused by using inet_sk() on the
wrong socket (the L2TP socket rather than the underlying UDP socket), and was
likely introduced during the addition of L2TPv3 support.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-20 16:12:11 -04:00
Paul Mackerras 4b32da2bcf ppp: Replace uses of <linux/if_ppp.h> with <linux/ppp-ioctl.h>
Since all that include/linux/if_ppp.h does is #include <linux/ppp-ioctl.h>,
this replaces the occurrences of #include <linux/if_ppp.h> with
#include <linux/ppp-ioctl.h>.

It also corrects an error in Documentation/networking/l2tp.txt, where
it referenced include/linux/if_ppp.h as the source of some definitions
that are actually now defined in include/linux/if_pppol2tp.h.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-04 20:41:38 -05:00
Eric Dumazet 09df57ca60 l2tp: give proper headroom in pppol2tp_xmit()
pppol2tp_xmit() calls skb_cow_head(skb, 2) before calling
l2tp_xmit_skb()

Then l2tp_xmit_skb() calls again skb_cow_head(skb, large_headroom)

This patchs changes the first skb_cow_head() call to supply the needed
headroom to make sure at most one (expensive) pskb_expand_head() is
done.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-18 23:33:44 -04:00
Arun Sharma 60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
Eric Dumazet 756e64a0b1 net: constify some ppp/pptp structs
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-21 18:04:47 -07:00
stephen hemminger d7100da026 ppp: make channel_ops const
The PPP channel ops structure should be const.
Cleanup the declarations to use standard C99 format.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-04 21:53:17 -07:00
David S. Miller f66ef2d064 l2tp: Fix L2TP_DEBUGFS ifdef tests.
We have to check CONFIG_L2TP_DEBUGFS_MODULE as well as
CONFIG_L2TP_DEBUGFS.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 15:01:37 -07:00
James Chapman 0ad6614048 l2tp: Add debugfs files for dumping l2tp debug info
The existing pppol2tp driver exports debug info to
/proc/net/pppol2tp. Rather than adding info to that file for the new
functionality added in this patch series, we add new files in debugfs,
leaving the old /proc file for backwards compatibility (L2TPv2 only).

Currently only one file is provided: l2tp/tunnels, which lists
internal debug info for all l2tp tunnels and sessions. More files may
be added later. The info is for debug and problem analysis only -
userspace apps should use netlink to obtain status about l2tp tunnels
and sessions.

Although debugfs does not support net namespaces, the tunnels and
sessions dumped in l2tp/tunnels are only those in the net namespace of
the process reading the file.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:07 -07:00
James Chapman 309795f4be l2tp: Add netlink control API for L2TP
In L2TPv3, we need to create/delete/modify/query L2TP tunnel and
session contexts. The number of parameters is significant. So let's
use netlink. Userspace uses this API to control L2TP tunnel/session
contexts in the kernel.

The previous pppol2tp driver was managed using [gs]etsockopt(). This
API is retained for backwards compatibility. Unlike L2TPv2 which
carries only PPP frames, L2TPv3 can carry raw ethernet frames or other
frame types and these do not always have an associated socket
family. Therefore, we need a way to use L2TP sessions that doesn't
require a socket type for each supported frame type. Hence netlink is
used.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:05 -07:00
James Chapman 0d76751fad l2tp: Add L2TPv3 IP encapsulation (no UDP) support
This patch adds a new L2TPIP socket family and modifies the core to
handle the case where there is no UDP header in the L2TP
packet. L2TP/IP uses IP protocol 115. Since L2TP/UDP and L2TP/IP
packets differ in layout, the datapath packet handling code needs
changes too. Userspace uses an L2TPIP socket instead of a UDP socket
when IP encapsulation is required.

We can't use raw sockets for this because the semantics of raw sockets
don't lend themselves to the socket-per-tunnel model - we need to

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:04 -07:00
James Chapman e0d4435f93 l2tp: Update PPP-over-L2TP driver to work over L2TPv3
This patch makes changes to the L2TP PPP code for L2TPv3.

The existing code has some assumptions about the L2TP header which are
broken by L2TPv3. Also the sockaddr_pppol2tp structure of the original
code is too small to support the increased size of the L2TPv3 tunnel
and session id, so a new sockaddr_pppol2tpv3 structure is needed. In
the socket calls, the size of this structure is used to tell if the
operation is for L2TPv2 or L2TPv3.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:04 -07:00
James Chapman f7faffa3ff l2tp: Add L2TPv3 protocol support
The L2TPv3 protocol changes the layout of the L2TP packet
header. Tunnel and session ids change from 16-bit to 32-bit values,
data sequence numbers change from 16-bit to 24-bit values and PPP-specific
fields are moved into protocol-specific subheaders.

Although this patch introduces L2TPv3 protocol support, there are no
userspace interfaces to create L2TPv3 sessions yet.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:03 -07:00
James Chapman 9345471bca l2tp: Add ppp device name to L2TP ppp session data
When dumping L2TP PPP sessions using /proc/net/pppol2tp, get the
assigned PPP device name from PPP using ppp_dev_name().

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:03 -07:00
James Chapman fd558d186d l2tp: Split pppol2tp patch into separate l2tp and ppp parts
This patch splits the pppol2tp driver into separate L2TP and PPP parts
to prepare for L2TPv3 support. In L2TPv3, protocols other than PPP can
be carried, so this split creates a common L2TP core that will handle
the common L2TP bits which protocol support modules such as PPP will
use.

Note that the existing pppol2tp module is split into l2tp_core and
l2tp_ppp by this change.

There are no feature changes here. Internally, however, there are
significant changes, mostly to handle the separation of PPP-specific
data from the L2TP session and to provide hooks in the core for
modules like PPP to access.

Signed-off-by: James Chapman <jchapman@katalix.com>
Reviewed-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03 14:56:02 -07:00