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path: root/net/l2tp/l2tp_core.c
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2013-03-20l2tp: unhash l2tp sessions on delete, not on freeTom Parkin
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>
2013-03-20l2tp: avoid deadlock in l2tp stats updateTom Parkin
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>
2013-03-20l2tp: purge session reorder queue on deleteTom Parkin
Add calls to l2tp_session_queue_purge as a part of l2tp_tunnel_closeall and l2tp_session_delete. Pseudowire implementations which are deleted only via. l2tp_core l2tp_session_delete calls can dispense with their own code for flushing the reorder queue. 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>
2013-03-20l2tp: add session reorder queue purge function to coreTom Parkin
If an l2tp session is deleted, it is necessary to delete skbs in-flight on the session's reorder queue before taking it down. Rather than having each pseudowire implementation reaching into the l2tp_session struct to handle this itself, provide a function in l2tp_core to purge the session queue. 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>
2013-03-20l2tp: don't BUG_ON sk_socket being NULLTom Parkin
It is valid for an existing struct sock object to have a NULL sk_socket pointer, so don't BUG_ON in l2tp_tunnel_del_work if that should occur. 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>
2013-03-20l2tp: take a reference for kernel sockets in l2tp_tunnel_sock_lookupTom Parkin
When looking up the tunnel socket in struct l2tp_tunnel, hold a reference whether the socket was created by the kernel or by userspace. 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>
2013-03-20l2tp: close sessions before initiating tunnel deleteTom Parkin
When a user deletes a tunnel using netlink, all the sessions in the tunnel should also be deleted. Since running sessions will pin the tunnel socket with the references they hold, have the l2tp_tunnel_delete close all sessions in a tunnel before finally closing the tunnel socket. 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>
2013-03-20l2tp: export l2tp_tunnel_closeallTom Parkin
l2tp_core internally uses l2tp_tunnel_closeall to close all sessions in a tunnel when a UDP-encapsulation socket is destroyed. We need to do something similar for IP-encapsulation sockets. Export l2tp_tunnel_closeall as a GPL symbol to enable l2tp_ip and l2tp_ip6 to call it from their .destroy handlers. 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>
2013-03-20l2tp: add udp encap socket destroy handlerTom Parkin
L2TP sessions hold a reference to the tunnel socket to prevent it going away while sessions are still active. However, since tunnel destruction is handled by the sock sk_destruct callback there is a catch-22: a tunnel with sessions cannot be deleted since each session holds a reference to the tunnel socket. If userspace closes a managed tunnel socket, or dies, the tunnel will persist and it will be neccessary to individually delete the sessions using netlink commands. This is ugly. To prevent this occuring, this patch leverages the udp encapsulation socket destroy callback to gain early notification when the tunnel socket is closed. This allows us to safely close the sessions running in the tunnel, dropping the tunnel socket references in the process. The tunnel socket is then destroyed as normal, and the tunnel resources deallocated in sk_destruct. While we're at it, ensure that l2tp_tunnel_closeall correctly drops session references to allow the sessions to be deleted rather than leaking. 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>
2013-02-28hlist: drop the node parameter from iteratorsSasha Levin
I'm not sure why, but the hlist for each entry iterators were conceived list_for_each_entry(pos, head, member) The hlist ones were greedy and wanted an extra parameter: hlist_for_each_entry(tpos, pos, head, member) Why did they need an extra pos parameter? I'm not quite sure. Not only they don't really need it, it also prevents the iterator from looking exactly like the list iterator, which is unfortunate. Besides the semantic patch, there was some manual work required: - Fix up the actual hlist iterators in linux/list.h - Fix up the declaration of other iterators based on the hlist ones. - A very small amount of places were using the 'node' parameter, this was modified to use 'obj->member' instead. - Coccinelle didn't handle the hlist_for_each_entry_safe iterator properly, so those had to be fixed up manually. The semantic patch which is mostly the work of Peter Senna Tschudin is here: @@ iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host; type T; expression a,c,d,e; identifier b; statement S; @@ -T b; <+... when != b ( hlist_for_each_entry(a, - b, c, d) S | hlist_for_each_entry_continue(a, - b, c) S | hlist_for_each_entry_from(a, - b, c) S | hlist_for_each_entry_rcu(a, - b, c, d) S | hlist_for_each_entry_rcu_bh(a, - b, c, d) S | hlist_for_each_entry_continue_rcu_bh(a, - b, c) S | for_each_busy_worker(a, c, - b, d) S | ax25_uid_for_each(a, - b, c) S | ax25_for_each(a, - b, c) S | inet_bind_bucket_for_each(a, - b, c) S | sctp_for_each_hentry(a, - b, c) S | sk_for_each(a, - b, c) S | sk_for_each_rcu(a, - b, c) S | sk_for_each_from -(a, b) +(a) S + sk_for_each_from(a) S | sk_for_each_safe(a, - b, c, d) S | sk_for_each_bound(a, - b, c) S | hlist_for_each_entry_safe(a, - b, c, d, e) S | hlist_for_each_entry_continue_rcu(a, - b, c) S | nr_neigh_for_each(a, - b, c) S | nr_neigh_for_each_safe(a, - b, c, d) S | nr_node_for_each(a, - b, c) S | nr_node_for_each_safe(a, - b, c, d) S | - for_each_gfn_sp(a, c, d, b) S + for_each_gfn_sp(a, c, d) S | - for_each_gfn_indirect_valid_sp(a, c, d, b) S + for_each_gfn_indirect_valid_sp(a, c, d) S | for_each_host(a, - b, c) S | for_each_host_safe(a, - b, c, d) S | for_each_mesh_entry(a, - b, c, d) S ) ...+> [akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c] [akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c] [akpm@linux-foundation.org: checkpatch fixes] [akpm@linux-foundation.org: fix warnings] [akpm@linux-foudnation.org: redo intrusive kvm changes] Tested-by: Peter Senna Tschudin <peter.senna@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
Synchronize with 'net' in order to sort out some l2tp, wireless, and ipv6 GRE fixes that will be built on top of in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-08l2tp: dont play with skb->truesizeEric Dumazet
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>
2013-02-05l2tp: create tunnel sockets in the right namespaceTom Parkin
When creating unmanaged tunnel sockets we should honour the network namespace passed to l2tp_tunnel_create. Furthermore, unmanaged tunnel sockets should not hold a reference to the network namespace lest they accidentally keep alive a namespace which should otherwise have been released. Unmanaged tunnel sockets now drop their namespace reference via sk_change_net, and are released in a new pernet exit callback, l2tp_exit_net. 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>
2013-02-05l2tp: prevent tunnel creation on netns mismatchTom Parkin
l2tp_tunnel_create is passed a pointer to the network namespace for the tunnel, along with an optional file descriptor for the tunnel which may be passed in from userspace via. netlink. In the case where the file descriptor is defined, ensure that the namespace associated with that socket matches the namespace explicitly passed to l2tp_tunnel_create. 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>
2013-02-05l2tp: put tunnel socket release on a workqueueTom Parkin
To allow l2tp_tunnel_delete to be called from an atomic context, place the tunnel socket release calls on a workqueue for asynchronous execution. Tunnel memory is eventually freed in the tunnel socket destructor. 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>
2013-01-29l2tp: prevent l2tp_tunnel_delete racing with userspace closeTom Parkin
If a tunnel socket is created by userspace, l2tp hooks the socket destructor in order to clean up resources if userspace closes the socket or crashes. It also caches a pointer to the struct sock for use in the data path and in the netlink interface. While it is safe to use the cached sock pointer in the data path, where the skb references keep the socket alive, it is not safe to use it elsewhere as such access introduces a race with userspace closing the socket. In particular, l2tp_tunnel_delete is prone to oopsing if a multithreaded userspace application closes a socket at the same time as sending a netlink delete command for the tunnel. This patch fixes this oops by forcing l2tp_tunnel_delete to explicitly look up a tunnel socket held by userspace using sockfd_lookup(). 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>
2012-09-04l2tp: fix a lockdep splatEric Dumazet
Fixes following lockdep splat : [ 1614.734896] ============================================= [ 1614.734898] [ INFO: possible recursive locking detected ] [ 1614.734901] 3.6.0-rc3+ #782 Not tainted [ 1614.734903] --------------------------------------------- [ 1614.734905] swapper/11/0 is trying to acquire lock: [ 1614.734907] (slock-AF_INET){+.-...}, at: [<ffffffffa0209d72>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core] [ 1614.734920] [ 1614.734920] but task is already holding lock: [ 1614.734922] (slock-AF_INET){+.-...}, at: [<ffffffff815fce23>] tcp_v4_err+0x163/0x6b0 [ 1614.734932] [ 1614.734932] other info that might help us debug this: [ 1614.734935] Possible unsafe locking scenario: [ 1614.734935] [ 1614.734937] CPU0 [ 1614.734938] ---- [ 1614.734940] lock(slock-AF_INET); [ 1614.734943] lock(slock-AF_INET); [ 1614.734946] [ 1614.734946] *** DEADLOCK *** [ 1614.734946] [ 1614.734949] May be due to missing lock nesting notation [ 1614.734949] [ 1614.734952] 7 locks held by swapper/11/0: [ 1614.734954] #0: (rcu_read_lock){.+.+..}, at: [<ffffffff81592801>] __netif_receive_skb+0x251/0xd00 [ 1614.734964] #1: (rcu_read_lock){.+.+..}, at: [<ffffffff815d319c>] ip_local_deliver_finish+0x4c/0x4e0 [ 1614.734972] #2: (rcu_read_lock){.+.+..}, at: [<ffffffff8160d116>] icmp_socket_deliver+0x46/0x230 [ 1614.734982] #3: (slock-AF_INET){+.-...}, at: [<ffffffff815fce23>] tcp_v4_err+0x163/0x6b0 [ 1614.734989] #4: (rcu_read_lock){.+.+..}, at: [<ffffffff815da240>] ip_queue_xmit+0x0/0x680 [ 1614.734997] #5: (rcu_read_lock_bh){.+....}, at: [<ffffffff815d9925>] ip_finish_output+0x135/0x890 [ 1614.735004] #6: (rcu_read_lock_bh){.+....}, at: [<ffffffff81595680>] dev_queue_xmit+0x0/0xe00 [ 1614.735012] [ 1614.735012] stack backtrace: [ 1614.735016] Pid: 0, comm: swapper/11 Not tainted 3.6.0-rc3+ #782 [ 1614.735018] Call Trace: [ 1614.735020] <IRQ> [<ffffffff810a50ac>] __lock_acquire+0x144c/0x1b10 [ 1614.735033] [<ffffffff810a334b>] ? check_usage+0x9b/0x4d0 [ 1614.735037] [<ffffffff810a6762>] ? mark_held_locks+0x82/0x130 [ 1614.735042] [<ffffffff810a5df0>] lock_acquire+0x90/0x200 [ 1614.735047] [<ffffffffa0209d72>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core] [ 1614.735051] [<ffffffff810a69ad>] ? trace_hardirqs_on+0xd/0x10 [ 1614.735060] [<ffffffff81749b31>] _raw_spin_lock+0x41/0x50 [ 1614.735065] [<ffffffffa0209d72>] ? l2tp_xmit_skb+0x172/0xa50 [l2tp_core] [ 1614.735069] [<ffffffffa0209d72>] l2tp_xmit_skb+0x172/0xa50 [l2tp_core] [ 1614.735075] [<ffffffffa014f7f2>] l2tp_eth_dev_xmit+0x32/0x60 [l2tp_eth] [ 1614.735079] [<ffffffff81595112>] dev_hard_start_xmit+0x502/0xa70 [ 1614.735083] [<ffffffff81594c6e>] ? dev_hard_start_xmit+0x5e/0xa70 [ 1614.735087] [<ffffffff815957c1>] ? dev_queue_xmit+0x141/0xe00 [ 1614.735093] [<ffffffff815b622e>] sch_direct_xmit+0xfe/0x290 [ 1614.735098] [<ffffffff81595865>] dev_queue_xmit+0x1e5/0xe00 [ 1614.735102] [<ffffffff81595680>] ? dev_hard_start_xmit+0xa70/0xa70 [ 1614.735106] [<ffffffff815b4daa>] ? eth_header+0x3a/0xf0 [ 1614.735111] [<ffffffff8161d33e>] ? fib_get_table+0x2e/0x280 [ 1614.735117] [<ffffffff8160a7e2>] arp_xmit+0x22/0x60 [ 1614.735121] [<ffffffff8160a863>] arp_send+0x43/0x50 [ 1614.735125] [<ffffffff8160b82f>] arp_solicit+0x18f/0x450 [ 1614.735132] [<ffffffff8159d9da>] neigh_probe+0x4a/0x70 [ 1614.735137] [<ffffffff815a191a>] __neigh_event_send+0xea/0x300 [ 1614.735141] [<ffffffff815a1c93>] neigh_resolve_output+0x163/0x260 [ 1614.735146] [<ffffffff815d9cf5>] ip_finish_output+0x505/0x890 [ 1614.735150] [<ffffffff815d9925>] ? ip_finish_output+0x135/0x890 [ 1614.735154] [<ffffffff815dae79>] ip_output+0x59/0xf0 [ 1614.735158] [<ffffffff815da1cd>] ip_local_out+0x2d/0xa0 [ 1614.735162] [<ffffffff815da403>] ip_queue_xmit+0x1c3/0x680 [ 1614.735165] [<ffffffff815da240>] ? ip_local_out+0xa0/0xa0 [ 1614.735172] [<ffffffff815f4402>] tcp_transmit_skb+0x402/0xa60 [ 1614.735177] [<ffffffff815f5a11>] tcp_retransmit_skb+0x1a1/0x620 [ 1614.735181] [<ffffffff815f7e93>] tcp_retransmit_timer+0x393/0x960 [ 1614.735185] [<ffffffff815fce23>] ? tcp_v4_err+0x163/0x6b0 [ 1614.735189] [<ffffffff815fd317>] tcp_v4_err+0x657/0x6b0 [ 1614.735194] [<ffffffff8160d116>] ? icmp_socket_deliver+0x46/0x230 [ 1614.735199] [<ffffffff8160d19e>] icmp_socket_deliver+0xce/0x230 [ 1614.735203] [<ffffffff8160d116>] ? icmp_socket_deliver+0x46/0x230 [ 1614.735208] [<ffffffff8160d464>] icmp_unreach+0xe4/0x2c0 [ 1614.735213] [<ffffffff8160e520>] icmp_rcv+0x350/0x4a0 [ 1614.735217] [<ffffffff815d3285>] ip_local_deliver_finish+0x135/0x4e0 [ 1614.735221] [<ffffffff815d319c>] ? ip_local_deliver_finish+0x4c/0x4e0 [ 1614.735225] [<ffffffff815d3ffa>] ip_local_deliver+0x4a/0x90 [ 1614.735229] [<ffffffff815d37b7>] ip_rcv_finish+0x187/0x730 [ 1614.735233] [<ffffffff815d425d>] ip_rcv+0x21d/0x300 [ 1614.735237] [<ffffffff81592a1b>] __netif_receive_skb+0x46b/0xd00 [ 1614.735241] [<ffffffff81592801>] ? __netif_receive_skb+0x251/0xd00 [ 1614.735245] [<ffffffff81593368>] process_backlog+0xb8/0x180 [ 1614.735249] [<ffffffff81593cf9>] net_rx_action+0x159/0x330 [ 1614.735257] [<ffffffff810491f0>] __do_softirq+0xd0/0x3e0 [ 1614.735264] [<ffffffff8109ed24>] ? tick_program_event+0x24/0x30 [ 1614.735270] [<ffffffff8175419c>] call_softirq+0x1c/0x30 [ 1614.735278] [<ffffffff8100425d>] do_softirq+0x8d/0xc0 [ 1614.735282] [<ffffffff8104983e>] irq_exit+0xae/0xe0 [ 1614.735287] [<ffffffff8175494e>] smp_apic_timer_interrupt+0x6e/0x99 [ 1614.735291] [<ffffffff81753a1c>] apic_timer_interrupt+0x6c/0x80 [ 1614.735293] <EOI> [<ffffffff810a14ad>] ? trace_hardirqs_off+0xd/0x10 [ 1614.735306] [<ffffffff81336f85>] ? intel_idle+0xf5/0x150 [ 1614.735310] [<ffffffff81336f7e>] ? intel_idle+0xee/0x150 [ 1614.735317] [<ffffffff814e6ea9>] cpuidle_enter+0x19/0x20 [ 1614.735321] [<ffffffff814e7538>] cpuidle_idle_call+0xa8/0x630 [ 1614.735327] [<ffffffff8100c1ba>] cpu_idle+0x8a/0xe0 [ 1614.735333] [<ffffffff8173762e>] start_secondary+0x220/0x222 Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-30l2tp: avoid to use synchronize_rcu in tunnel free functionxeb@mail.ru
Avoid to use synchronize_rcu in l2tp_tunnel_free because context may be atomic. Signed-off-by: Dmitry Kozlov <xeb@mail.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-29net: l2tp_eth: provide tx_dropped counterEric Dumazet
Change l2tp_xmit_skb() to return NET_XMIT_DROP in case skb is dropped. Use kfree_skb() instead dev_kfree_skb() for drop_monitor pleasure. Support tx_dropped counter for l2tp_eth Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-17net: l2tp: Standardize logging stylesJoe Perches
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>
2012-05-11l2tp: fix data packet sequence number handlingJames Chapman
If enabled, L2TP data packets have sequence numbers which a receiver can use to drop out of sequence frames or try to reorder them. The first frame has sequence number 0, but the L2TP code currently expects it to be 1. This results in the first data frame being handled as out of sequence. This one-line patch fixes the problem. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-11l2tp: fix reorder timeout recoveryJames Chapman
When L2TP data packet reordering is enabled, packets are held in a queue while waiting for out-of-sequence packets. If a packet gets lost, packets will be held until the reorder timeout expires, when we are supposed to then advance to the sequence number of the next packet but we don't currently do so. As a result, the data channel is stuck because we are waiting for a packet that will never arrive - all packets age out and none are passed. The fix is to add a flag to the session context, which is set when the reorder timeout expires and tells the receive code to reset the next expected sequence number to that of the next packet in the queue. Tested in a production L2TP network with Starent and Nortel L2TP gear. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: let iproute2 create L2TPv3 IP tunnels using IPv6James Chapman
The netlink API lets users create unmanaged L2TPv3 tunnels using iproute2. Until now, a request to create an unmanaged L2TPv3 IP encapsulation tunnel over IPv6 would be rejected with EPROTONOSUPPORT. Now that l2tp_ip6 implements sockets for L2TP IP encapsulation over IPv6, we can add support for that tunnel type. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: netlink api for l2tpv3 ipv6 unmanaged tunnelsChris Elston
This patch adds support for unmanaged L2TPv3 tunnels over IPv6 using the netlink API. We already support unmanaged L2TPv3 tunnels over IPv4. A patch to iproute2 to make use of this feature will be submitted separately. Signed-off-by: Chris Elston <celston@katalix.com> Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01l2tp: fix locking of 64-bit counters for smpJames Chapman
L2TP uses 64-bit counters but since these are not updated atomically, we need to make them safe for smp. This patch addresses that. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-30l2tp: Add missing net/net/ip6_checksum.h include.David S. Miller
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-29net/l2tp: add support for L2TP over IPv6 UDPBenjamin LaHaise
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>
2012-04-13udp: intoduce udp_encap_needed static_keyEric Dumazet
Most machines dont use UDP encapsulation (L2TP) Adds a static_key so that udp_queue_rcv_skb() doesnt have to perform a test if L2TP never setup the encap_rcv on a socket. Idea of this patch came after Simon Horman proposal to add a hook on TCP as well. If static_key is not yet enabled, the fast path does a single JMP . When static_key is enabled, JMP destination is patched to reach the real encap_type/encap_rcv logic, possibly adding cache misses. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Simon Horman <horms@verge.net.au> Cc: dev@openvswitch.org Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26l2tp: ensure sk->dst is still validFlorian Westphal
When using l2tp over ipsec, the tunnel will hang when rekeying occurs. Reason is that the transformer bundle attached to the dst entry is now in STATE_DEAD and thus xfrm_output_one() drops all packets (XfrmOutStateExpired increases). Fix this by calling __sk_dst_check (which drops the stale dst if xfrm dst->check callback finds that the bundle is no longer valid). Cc: James Chapman <jchapman@katalix.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-08l2tp: fix l2tp_udp_recv_core()Eric Dumazet
pskb_may_pull() can change skb->data, so we have to load ptr/optr at the right place. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-03l2tp: fix race in l2tp_recv_dequeue()Eric Dumazet
Misha Labjuk reported panics occurring in l2tp_recv_dequeue() If we release reorder_q.lock, we must not keep a dangling pointer (tmp), since another thread could manipulate reorder_q. Instead we must restart the scan at beginning of list. Reported-by: Misha Labjuk <spiked.yar@gmail.com> Tested-by: Misha Labjuk <spiked.yar@gmail.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-19l2tp: fix a potential skb leak in l2tp_xmit_skb()Eric Dumazet
l2tp_xmit_skb() can leak one skb if skb_cow_head() returns an error. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
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>
2011-05-12l2tp: fix potential rcu raceEric Dumazet
While trying to remove useless synchronize_rcu() calls, I found l2tp is indeed incorrectly using two of such calls, but also bumps tunnel refcount after list insertion. tunnel refcount must be incremented before being made publically visible by rcu readers. This fix can be applied to 2.6.35+ and might need a backport for older kernels, since things were shuffled in commit fd558d186df2c (l2tp: Split pppol2tp patch into separate l2tp and ppp parts) Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Paul E. McKenney <paulmck@linux.vnet.ibm.com> CC: James Chapman <jchapman@katalix.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-08inet: Pass flowi to ->queue_xmit().David S. Miller
This allows us to acquire the exact route keying information from the protocol, however that might be managed. It handles all of the possibilities, from the simplest case of storing the key in inet->cork.fl to the more complex setup SCTP has where individual transports determine the flow. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-08l2tp: Fix locking in l2tp_core.cDavid S. Miller
l2tp_xmit_skb() must take the socket lock. It makes use of ip_queue_xmit() which expects to execute in a socket atomic context. Since we execute this function in software interrupts, we cannot use the usual lock_sock()/release_sock() sequence, instead we have to use bh_lock_sock() and see if a user has the socket locked, and if so drop the packet. Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-25l2tp: static functions should not be exportedStephen Rothwell
Causes these build failures on PowerPC: net/l2tp/l2tp_core.c:1228: error: __ksymtab_l2tp_tunnel_closeall causes a section type conflict net/l2tp/l2tp_core.c:1228: error: __ksymtab_l2tp_tunnel_closeall causes a section type conflict net/l2tp/l2tp_core.c:1006: error: __ksymtab_l2tp_xmit_core causes a section type conflict net/l2tp/l2tp_core.c:1006: error: __ksymtab_l2tp_xmit_core causes a section type conflict net/l2tp/l2tp_core.c:847: error: __ksymtab_l2tp_udp_recv_core causes a section type conflict net/l2tp/l2tp_core.c:847: error: __ksymtab_l2tp_udp_recv_core causes a section type conflict Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-10-24l2tp: make local function staticstephen hemminger
Also moved the refcound inlines from l2tp_core.h to l2tp_core.c since only used in that one file. Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-23l2tp: fix memory allocationJiri Pirko
Since .size is set properly in "struct pernet_operations l2tp_net_ops", allocating space for "struct l2tp_net" by hand is not correct, even causes memory leakage. Signed-off-by: Jiri Pirko <jpirko@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-16net: replace ipfragok with skb->local_dfShan Wei
As Herbert Xu said: we should be able to simply replace ipfragok with skb->local_df. commit f88037(sctp: Drop ipfargok in sctp_xmit function) has droped ipfragok and set local_df value properly. The patch kills the ipfragok parameter of .queue_xmit(). Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-04l2tp: unmanaged L2TPv3 tunnels fixesEric Dumazet
Followup to commit 789a4a2c (l2tp: Add support for static unmanaged L2TPv3 tunnels) One missing init in l2tp_tunnel_sock_create() could access random kernel memory, and a bit field should be unsigned. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Add support for static unmanaged L2TPv3 tunnelsJames Chapman
This patch adds support for static (unmanaged) L2TPv3 tunnels, where the tunnel socket is created by the kernel rather than being created by userspace. This means L2TP tunnels and sessions can be created manually, without needing an L2TP control protocol implemented in userspace. This might be useful where the user wants a simple ethernet over IP tunnel. A patch to iproute2 adds a new command set under "ip l2tp" to make use of this feature. This will be submitted separately. 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>
2010-04-03l2tp: Convert rwlock to RCUJames Chapman
Reader/write locks are discouraged because they are slower than spin locks. So this patch converts the rwlocks used in the per_net structs to rcu. Signed-off-by: James Chapman <jchapman@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-03l2tp: Add netlink control API for L2TPJames Chapman
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>
2010-04-03l2tp: Add L2TPv3 IP encapsulation (no UDP) supportJames Chapman
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>
2010-04-03l2tp: Add L2TPv3 protocol supportJames Chapman
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>
2010-04-03l2tp: Split pppol2tp patch into separate l2tp and ppp partsJames Chapman
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>