Applications using L2TP/IP sockets want to be able to bind() an L2TP/IP
socket to set the local tunnel id while leaving the auto-assigned source
address alone. So if no source address is supplied, don't overwrite
the address already stored in the socket.
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The l2tp_ip socket close handler does not update the module refcount
correctly which prevents module unload after the first bind() call on
an L2TPv3 IP encapulation socket.
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a packet is received on an L2TP IP socket (L2TPv3 IP link
encapsulation), the l2tpip socket's backlog_rcv function calls
xfrm4_policy_check(). This is not necessary, since it was called
before the skb was added to the backlog. With CONFIG_NET_NS enabled,
xfrm4_policy_check() will oops if skb->dev is null, so this trivial
patch removes the call.

This bug has always been present, but only when CONFIG_NET_NS is
enabled does it cause problems. Most users are probably using UDP
encapsulation for L2TP, hence the problem has only recently
surfaced.

EIP: 0060:[<c12bb62b>] EFLAGS: 00210246 CPU: 0
EIP is at l2tp_ip_recvmsg+0xd4/0x2a7
EAX: 00000001 EBX: d77b5180 ECX: 00000000 EDX: 00200246
ESI: 00000000 EDI: d63cbd30 EBP: d63cbd18 ESP: d63cbcf4
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Call Trace:
 [<c1218568>] sock_common_recvmsg+0x31/0x46
 [<c1215c92>] __sock_recvmsg_nosec+0x45/0x4d
 [<c12163a1>] __sock_recvmsg+0x31/0x3b
 [<c1216828>] sock_recvmsg+0x96/0xab
 [<c10b2693>] ? might_fault+0x47/0x81
 [<c10b2693>] ? might_fault+0x47/0x81
 [<c1167fd0>] ? _copy_from_user+0x31/0x115
 [<c121e8c8>] ? copy_from_user+0x8/0xa
 [<c121ebd6>] ? verify_iovec+0x3e/0x78
 [<c1216604>] __sys_recvmsg+0x10a/0x1aa
 [<c1216792>] ? sock_recvmsg+0x0/0xab
 [<c105a99b>] ? __lock_acquire+0xbdf/0xbee
 [<c12d5a99>] ? do_page_fault+0x193/0x375
 [<c10d1200>] ? fcheck_files+0x9b/0xca
 [<c10d1259>] ? fget_light+0x2a/0x9c
 [<c1216bbb>] sys_recvmsg+0x2b/0x43
 [<c1218145>] sys_socketcall+0x16d/0x1a5
 [<c11679f0>] ? trace_hardirqs_on_thunk+0xc/0x10
 [<c100305f>] sysenter_do_call+0x12/0x38
Code: c6 05 8c ea a8 c1 01 e8 0c d4 d9 ff 85 f6 74 07 3e ff 86 80 00 00 00 b9 17 b6 2b c1 ba 01 00 00 00 b8 78 ed 48 c1 e8 23 f6 d9 ff <ff> 76 0c 68 28 e3 30 c1 68 2d 44 41 c1 e8 89 57 01 00 83 c4 0c
Signed-off-by: NJames Chapman <jchapman@katalix.com>
Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_ip_sendmsg() in non connected mode incorrectly calls
sk_setup_caps(). Subsequent send() calls send data to wrong destination.

We can also avoid changing dst refcount in connected mode, using
appropriate rcu locking. Once output route lookups can also be done
under rcu, sendto() calls wont change dst refcounts too.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
CC: James Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@conan.davemloft.net>

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: NDavid S. Miller <davem@davemloft.net>

Now that the socket is consistently locked in these two routines,
this transformation is legal.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both l2tp_ip_connect() and l2tp_ip_sendmsg() must take the socket
lock.  They both modify socket state non-atomically, and in particular
l2tp_ip_sendmsg() increments socket private counters without using
atomic operations.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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

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

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

We don't actually hold the socket lock at this point, so the
rcu_dereference_protected() isn't' correct.  Thanks to Eric
Dumazet for pointing this out.

Thankfully, we're only interested in fetching the faddr value
if srr is enabled, so we can simply make this an RCU sequence
and use plain rcu_dereference().
Reported-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We lack proper synchronization to manipulate inet->opt ip_options

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

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

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

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

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

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

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

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

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

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

These changes were incorrectly fixed by codespell. They were now
manually corrected.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

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

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

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

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

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

Using the SOCK_DGRAM enum results in
"net-pf-2-proto-SOCK_DGRAM-type-115", so use the numeric value like it
is done in net/dccp.
Signed-off-by: NMichal Marek <mmarek@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the macros defined for the members of flowi to clean the code up.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Also moved the refcound inlines from l2tp_core.h to l2tp_core.c
since only used in that one file.
Signed-off-by: NStephen Hemminger <shemminger@vyatta.com>
Acked-by: NJames Chapman <jchapman@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

remove useless union keyword in rtable, rt6_info and dn_route.

Since there is only one member in a union, the union keyword isn't useful.
Signed-off-by: NChangli Gao <xiaosuo@gmail.com>
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NShan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

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: NDavid S. Miller <davem@davemloft.net>