linux-toradex.git/net/tipc/msg.c, branch v4.9.62

tipc: use only positive error codes in messages

2017-10-12T09:51:23+00:00

[ Upstream commit aad06212d36cf34859428a0a279e5c14ee5c9e26 ]

In commit e3a77561e7d32 ("tipc: split up function tipc_msg_eval()"),
we have updated the function tipc_msg_lookup_dest() to set the error
codes to negative values at destination lookup failures. Thus when
the function sets the error code to -TIPC_ERR_NO_NAME, its inserted
into the 4 bit error field of the message header as 0xf instead of
TIPC_ERR_NO_NAME (1). The value 0xf is an unknown error code.

In this commit, we set only positive error code.

Fixes: e3a77561e7d32 ("tipc: split up function tipc_msg_eval()")
Signed-off-by: Parthasarathy Bhuvaragan 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: allocate user memory with GFP_KERNEL flag

2017-07-05T12:40:27+00:00

[ Upstream commit 57d5f64d83ab5b5a5118b1597386dd76eaf4340d ]

Until now, we allocate memory always with GFP_ATOMIC flag.
When the system is under memory pressure and a user tries to send,
the send fails due to low memory. However, the user application
can wait for free memory if we allocate it using GFP_KERNEL flag.

In this commit, we use allocate memory with GFP_KERNEL for all user
allocation.

Reported-by: Rune Torgersen 
Acked-by: Jon Maloy 
Signed-off-by: Parthasarathy Bhuvaragan 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

net: tipc: Fix a sleep-in-atomic bug in tipc_msg_reverse

2017-07-05T12:40:14+00:00

[ Upstream commit 343eba69c6968190d8654b857aea952fed9a6749 ]

The kernel may sleep under a rcu read lock in tipc_msg_reverse, and the
function call path is:
tipc_l2_rcv_msg (acquire the lock by rcu_read_lock)
  tipc_rcv
    tipc_sk_rcv
      tipc_msg_reverse
        pskb_expand_head(GFP_KERNEL) --> may sleep
tipc_node_broadcast
  tipc_node_xmit_skb
    tipc_node_xmit
      tipc_sk_rcv
        tipc_msg_reverse
          pskb_expand_head(GFP_KERNEL) --> may sleep

To fix it, "GFP_KERNEL" is replaced with "GFP_ATOMIC".

Signed-off-by: Jia-Ju Bai 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tipc: unclone unbundled buffers before forwarding

2016-06-22T20:33:35+00:00

When extracting an individual message from a received "bundle" buffer,
we just create a clone of the base buffer, and adjust it to point into
the right position of the linearized data area of the latter. This works
well for regular message reception, but during periods of extremely high
load it may happen that an extracted buffer, e.g, a connection probe, is
reversed and forwarded through an external interface while the preceding
extracted message is still unhandled. When this happens, the header or
data area of the preceding message will be partially overwritten by a
MAC header, leading to unpredicatable consequences, such as a link
reset.

We now fix this by ensuring that the msg_reverse() function never
returns a cloned buffer, and that the returned buffer always contains
sufficient valid head and tail room to be forwarded.

Reported-by: Erik Hugne 
Acked-by: Ying Xue 
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: let broadcast packet reception use new link receive function

2015-10-24T13:56:37+00:00

The code path for receiving broadcast packets is currently distinct
from the unicast path. This leads to unnecessary code and data
duplication, something that can be avoided with some effort.

We now introduce separate per-peer tipc_link instances for handling
broadcast packet reception. Each receive link keeps a pointer to the
common, single, broadcast link instance, and can hence handle release
and retransmission of send buffers as if they belonged to the own
instance.

Furthermore, we let each unicast link instance keep a reference to both
the pertaining broadcast receive link, and to the common send link.
This makes it possible for the unicast links to easily access data for
broadcast link synchronization, as well as for carrying acknowledges for
received broadcast packets.

Signed-off-by: Jon Maloy 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: let broadcast transmission use new link transmit function

2015-10-24T13:56:32+00:00

This commit simplifies the broadcast link transmission function, by
leveraging previous changes to the link transmission function and the
broadcast transmission link life cycle.

Signed-off-by: Jon Maloy 
Reviewed-by: Ying Xue 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2015-10-24T13:54:12+00:00

Conflicts:
	net/ipv6/xfrm6_output.c
	net/openvswitch/flow_netlink.c
	net/openvswitch/vport-gre.c
	net/openvswitch/vport-vxlan.c
	net/openvswitch/vport.c
	net/openvswitch/vport.h

The openvswitch conflicts were overlapping changes.  One was
the egress tunnel info fix in 'net' and the other was the
vport ->send() op simplification in 'net-next'.

The xfrm6_output.c conflicts was also a simplification
overlapping a bug fix.

Signed-off-by: David S. Miller

tipc: allow non-linear first fragment buffer

2015-10-22T02:08:24+00:00

The current code for message reassembly is erroneously assuming that
the the first arriving fragment buffer always is linear, and then goes
ahead resetting the fragment list of that buffer in anticipation of
more arriving fragments.

However, if the buffer already happens to be non-linear, we will
inadvertently drop the already attached fragment list, and later
on trig a BUG() in __pskb_pull_tail().

We see this happen when running fragmented TIPC multicast across UDP,
something made possible since
commit d0f91938bede ("tipc: add ip/udp media type")

We fix this by not resetting the fragment list when the buffer is non-
linear, and by initiatlizing our private fragment list tail pointer to
the tail of the existing fragment list.

Fixes: commit d0f91938bede ("tipc: add ip/udp media type")
Signed-off-by: Jon Maloy 
Signed-off-by: David S. Miller

tipc: disallow packet duplicates in link deferred queue

2015-10-16T06:55:21+00:00

After the previous commits, we are guaranteed that no packets
of type LINK_PROTOCOL or with illegal sequence numbers will be
attempted added to the link deferred queue. This makes it possible to
make some simplifications to the sorting algorithm in the function
tipc_skb_queue_sorted().

We also alter the function so that it will drop packets if one with
the same seqeunce number is already present in the queue. This is
necessary because we have identified weird packet sequences, involving
duplicate packets, where a legitimate in-sequence packet may advance to
the head of the queue without being detected and de-queued.

Finally, we make this function outline, since it will now be called only
in exceptional cases.

Signed-off-by: Jon Maloy 
Acked-by: Ying Xue 
Signed-off-by: David S. Miller

tipc: reinitialize pointer after skb linearize

2015-09-21T05:31:20+00:00

The msg pointer into header may change after skb linearization.
We must reinitialize it after calling skb_linearize to prevent
operating on a freed or invalid pointer.

Signed-off-by: Erik Hugne 
Reported-by: Tamás Végh 
Acked-by: Ying Xue 
Signed-off-by: David S. Miller