Signed-off-by: NOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

When building can subsystem with CONFIG_PROC_FS=n I detected some unused
variables warning by using proc functions. In CAN the proc handling is
nicely placed in one object file. This patch adds simple add a
dependency on CONFIG_PROC_FS for CAN's proc.o file and corresponding
static inline no-op functions.
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Acked-by: NOliver Hartkopp <socketcan@hartkopp.net>
[mkl: provide static inline noops instead of using #ifdefs]
Signed-off-by: NMarc Kleine-Budde <mkl@pengutronix.de>

When we check for RTM_DELTFILTER, we should also reject the request
for deleting all filters under a given parent when TCA_KIND attribute
is present. If present, it's currently just ignored but there's also
no point to let it pass in the first place either since this doesn't
have any meaning with wild-card removal.

Fixes: ea7f8277 ("net, cls: allow for deleting all filters for given parent")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Modern C standards expect the '__inline__' keyword to come before the return
type in a declaration, and we get a couple of warnings for this with "make W=1"
in the xfrm{4,6}_policy.c files:

net/ipv6/xfrm6_policy.c:369:1: error: 'inline' is not at beginning of declaration [-Werror=old-style-declaration]
 static int inline xfrm6_net_sysctl_init(struct net *net)
net/ipv6/xfrm6_policy.c:374:1: error: 'inline' is not at beginning of declaration [-Werror=old-style-declaration]
 static void inline xfrm6_net_sysctl_exit(struct net *net)
net/ipv4/xfrm4_policy.c:339:1: error: 'inline' is not at beginning of declaration [-Werror=old-style-declaration]
 static int inline xfrm4_net_sysctl_init(struct net *net)
net/ipv4/xfrm4_policy.c:344:1: error: 'inline' is not at beginning of declaration [-Werror=old-style-declaration]
 static void inline xfrm4_net_sysctl_exit(struct net *net)
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The space is missing after ',', and this will introduce much more
noise when checking patch around.
Signed-off-by: NWei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes the checkpatch.pl error to dev.c:

ERROR: do not initialise statics to 0
Signed-off-by: NWei Tang <tangwei@cmss.chinamobile.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This appears to be necessary and sufficient to provide
MPLS in GRE (RFC4023) support.

This can be used by establishing an ipgre tunnel device
and then routing MPLS over it.

The following example will forward MPLS frames received with an outermost
MPLS label 100 over tun1, a GRE tunnel. The forwarded packet will have the
outermost MPLS LSE removed and two new LSEs added with labels 200
(outermost) and 300 (next).

ip link add name tun1 type gre remote 10.0.99.193 local 10.0.99.192 ttl 225
ip link set up dev tun1
ip addr add 10.0.98.192/24 dev tun1
ip route sh

echo 1 > /proc/sys/net/mpls/conf/eth0/input
echo 101 > /proc/sys/net/mpls/platform_labels
ip -f mpls route add 100 as 200/300 via inet 10.0.98.193
ip -f mpls route sh

Also remove unnecessary braces.
Reviewed-by: NDinan Gunawardena <dinan.gunawardena@netronome.com>
Signed-off-by: NSimon Horman <simon.horman@netronome.com>
Acked-by: NRobert Shearman <rshearma@brocade.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit d46e416c ("sctp: sctp should change socket state when
shutdown is received") may set sk_state CLOSING in sctp_sock_migrate,
but inet_accept doesn't allow the sk_state other than ESTABLISHED/
CLOSED for sctp. So we will change sk_state to CLOSED, instead of
CLOSING, as actually sk is closed already there.

Fixes: d46e416c ("sctp: sctp should change socket state when shutdown is received")
Reported-by: NYe Xiaolong <xiaolong.ye@intel.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The algorithm for checksum neutral mapping is incorrect. This problem
was being hidden since we were previously always performing checksum
offload on the translated addresses and only with IPv6 HW csum.
Enabling an ILA router shows the issue.

Corrected algorithm:

old_loc is the original locator in the packet, new_loc is the value
to overwrite with and is found in the lookup table. old_flag is
the old flag value (zero of CSUM_NEUTRAL_FLAG) and new_flag is
then (old_flag ^ CSUM_NEUTRAL_FLAG) & CSUM_NEUTRAL_FLAG.

Need SUM(new_id + new_flag + diff) == SUM(old_id + old_flag) for
checksum neutral translation.

Solving for diff gives:

diff = (old_id - new_id) + (old_flag - new_flag)

compute_csum_diff8(new_id, old_id) gives old_id - new_id

If old_flag is set
   old_flag - new_flag = old_flag = CSUM_NEUTRAL_FLAG
Else
   old_flag - new_flag = -new_flag = ~CSUM_NEUTRAL_FLAG

Tested:
  - Implemented a user space program that creates random addresses
    and random locators to overwrite. Compares the checksum over
    the address before and after translation (must always be equal)
  - Enabled ILA router and showed proper operation.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

    In the presence of firewalls which improperly block ICMP Unreachable
    (including Fragmentation Required) messages, Path MTU Discovery is
    prevented from working.

    A workaround is to handle IPv4 payloads opaquely, ignoring the DF bit--as
    is done for other payloads like AppleTalk--and doing transparent
    fragmentation and reassembly.

    Redux includes the enforcement of mutual exclusion between this feature
    and Path MTU Discovery as suggested by Alexander Duyck.

    Cc: Alexander Duyck <alexander.duyck@gmail.com>
Reviewed-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NPhilip Prindeville <philipp@redfish-solutions.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds necessary handling for use the short address for
802.15.4 6lowpan. It contains support for IPHC address compression
and new matching algorithmn to decide which link layer address will be
used for 802.15.4 frame.
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In case of sending RA messages we need some way to get the short address
from an 802.15.4 6LoWPAN interface. This patch will add a temporary
debugfs entry for experimental userspace api.
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduce different 6lowpan handling for receive and transmit
NS/NA messages for the ipv6 neighbour discovery. The first use-case is
for supporting 802.15.4 short addresses inside the option fields and
handling for RFC6775 6CO option field as userspace option.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Acked-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch exports some neighbour discovery functions which can be used
by 6lowpan neighbour discovery ops functionality then.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces neighbour discovery ops callback structure. The
idea is to separate the handling for 6LoWPAN into the 6lowpan module.

These callback offers 6lowpan different handling, such as 802.15.4 short
address handling or RFC6775 (Neighbor Discovery Optimization for IPv6
over 6LoWPANs).

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch moves the functionality to add a RA PIO prefix generated
address in an own function. This move prepares to add a hook for
adding a second address for a second link-layer address. E.g. short
address for 802.15.4 6LoWPAN.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Acked-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds __ndisc_fill_addr_option as low-level function for
ndisc_fill_addr_option which doesn't depend on net_device parameter.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since we use exported function from ipv6 kernel module we don't need to
request the module anymore to have ipv6 functionality.
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds the autoconfiguration if a valid 802.15.4 short address
is available for 802.15.4 6LoWPAN interfaces.

Cc: David S. Miller <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: James Morris <jmorris@namei.org>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Patrick McHardy <kaber@trash.net>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch will introduce a 6lowpan neighbour private data. Like the
interface private data we handle private data for generic 6lowpan and
for link-layer specific 6lowpan.

The current first use case if to save the short address for a 802.15.4
6lowpan neighbour.

Cc: David S. Miller <davem@davemloft.net>
Reviewed-by: NStefan Schmidt <stefan@osg.samsung.com>
Acked-by: NYOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: NAlexander Aring <aar@pengutronix.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sfq_reset() can use rtnl_kfree_skbs() instead of kfree_skb()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

pie_change() can use rtnl_qdisc_drop() to benefit from
deferred freeing.

pie_reset() is already using qdisc_reset_queue()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

rtnl_kfree_skbs() can be used in tfifo_reset()

It would be nice if we could iterate through rb tree instead
of removing one skb at a time, and build a single skb chain.
But this is left for a future patch.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both htb_reset() and htb_destroy() can use __qdisc_reset_queue()
instead of __skb_queue_purge() to defer skb freeing of internal
queues.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both hhf_reset() and hhf_change() can use rtnl_kfree_skbs()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both fq_codel_change() and fq_codel_reset() can use rtnl_kfree_skbs()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Both fq_change() and fq_reset() can use rtnl_kfree_skbs()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

codel_change() can use rtnl_qdisc_drop()
to defer expensive skb freeing after locks are released.

codel_reset() already has support for deferred skb freeing
because it uses qdisc_reset_queue()
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

choke_reset() and choke_change() can use rtnl_qdisc_drop()
to defer expensive skb freeing after locks are released.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qdisc are changed under RTNL protection and often
while blocking BH and root qdisc spinlock.

When lots of skbs need to be dropped, we free
them under these locks causing TX/RX freezes,
and more generally latency spikes.

This commit adds rtnl_kfree_skbs(), used to queue
skbs for deferred freeing.

Actual freeing happens right after RTNL is released,
with appropriate scheduling points.

rtnl_qdisc_drop() can also be used in place
of disc_drop() when RTNL is held.

qdisc_reset_queue() and __qdisc_reset_queue() get
the new behavior, so standard qdiscs like pfifo, pfifo_fast...
have their ->reset() method automatically handled.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TIPC based clusters are by default set up with full-mesh link
connectivity between all nodes. Those links are expected to provide
a short failure detection time, by default set to 1500 ms. Because
of this, the background load for neighbor monitoring in an N-node
cluster increases with a factor N on each node, while the overall
monitoring traffic through the network infrastructure increases at
a ~(N * (N - 1)) rate. Experience has shown that such clusters don't
scale well beyond ~100 nodes unless we significantly increase failure
discovery tolerance.

This commit introduces a framework and an algorithm that drastically
reduces this background load, while basically maintaining the original
failure detection times across the whole cluster. Using this algorithm,
background load will now grow at a rate of ~(2 * sqrt(N)) per node, and
at ~(2 * N * sqrt(N)) in traffic overhead. As an example, each node will
now have to actively monitor 38 neighbors in a 400-node cluster, instead
of as before 399.

This "Overlapping Ring Supervision Algorithm" is completely distributed
and employs no centralized or coordinated state. It goes as follows:

- Each node makes up a linearly ascending, circular list of all its N
  known neighbors, based on their TIPC node identity. This algorithm
  must be the same on all nodes.

- The node then selects the next M = sqrt(N) - 1 nodes downstream from
  itself in the list, and chooses to actively monitor those. This is
  called its "local monitoring domain".

- It creates a domain record describing the monitoring domain, and
  piggy-backs this in the data area of all neighbor monitoring messages
  (LINK_PROTOCOL/STATE) leaving that node. This means that all nodes in
  the cluster eventually (default within 400 ms) will learn about
  its monitoring domain.

- Whenever a node discovers a change in its local domain, e.g., a node
  has been added or has gone down, it creates and sends out a new
  version of its node record to inform all neighbors about the change.

- A node receiving a domain record from anybody outside its local domain
  matches this against its own list (which may not look the same), and
  chooses to not actively monitor those members of the received domain
  record that are also present in its own list. Instead, it relies on
  indications from the direct monitoring nodes if an indirectly
  monitored node has gone up or down. If a node is indicated lost, the
  receiving node temporarily activates its own direct monitoring towards
  that node in order to confirm, or not, that it is actually gone.

- Since each node is actively monitoring sqrt(N) downstream neighbors,
  each node is also actively monitored by the same number of upstream
  neighbors. This means that all non-direct monitoring nodes normally
  will receive sqrt(N) indications that a node is gone.

- A major drawback with ring monitoring is how it handles failures that
  cause massive network partitionings. If both a lost node and all its
  direct monitoring neighbors are inside the lost partition, the nodes in
  the remaining partition will never receive indications about the loss.
  To overcome this, each node also chooses to actively monitor some
  nodes outside its local domain. Those nodes are called remote domain
  "heads", and are selected in such a way that no node in the cluster
  will be more than two direct monitoring hops away. Because of this,
  each node, apart from monitoring the member of its local domain, will
  also typically monitor sqrt(N) remote head nodes.

- As an optimization, local list status, domain status and domain
  records are marked with a generation number. This saves senders from
  unnecessarily conveying  unaltered domain records, and receivers from
  performing unneeded re-adaptations of their node monitoring list, such
  as re-assigning domain heads.

- As a measure of caution we have added the possibility to disable the
  new algorithm through configuration. We do this by keeping a threshold
  value for the cluster size; a cluster that grows beyond this value
  will switch from full-mesh to ring monitoring, and vice versa when
  it shrinks below the value. This means that if the threshold is set to
  a value larger than any anticipated cluster size (default size is 32)
  the new algorithm is effectively disabled. A patch set for altering the
  threshold value and for listing the table contents will follow shortly.

- This change is fully backwards compatible.
Acked-by: NYing Xue <ying.xue@windriver.com>
Signed-off-by: NJon Maloy <jon.maloy@ericsson.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Acked-by: NJamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IPv6 multicast and link-local addresses require special handling by the
VRF driver:
1. Rather than using the VRF device index and full FIB lookups,
   packets to/from these addresses should use direct FIB lookups based on
   the VRF device table.

2. fail sends/receives on a VRF device to/from a multicast address
   (e.g, make ping6 ff02::1%<vrf> fail)

3. move the setting of the flow oif to the first dst lookup and revert
   the change in icmpv6_echo_reply made in ca254490 ("net: Add VRF
   support to IPv6 stack"). Linklocal/mcast addresses require use of the
   skb->dev.

With this change connections into and out of a VRF enslaved device work
for multicast and link-local addresses work (icmp, tcp, and udp)
e.g.,

1. packets into VM with VRF config:
    ping6 -c3 fe80::e0:f9ff:fe1c:b974%br1
    ping6 -c3 ff02::1%br1

    ssh -6 fe80::e0:f9ff:fe1c:b974%br1

2. packets going out a VRF enslaved device:
    ping6 -c3 fe80::18f8:83ff:fe4b:7a2e%eth1
    ping6 -c3 ff02::1%eth1
    ssh -6 root@fe80::18f8:83ff:fe4b:7a2e%eth1
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

L3 master devices are virtual devices similar to the loopback
device. Link local and multicast routes for these devices do
not make sense. The ipv6 addrconf code already skips adding a
linklocal address; do the same for the mcast route.
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow drivers to pass flow arg to functions where the arg is not const
and allow the driver to make updates as needed (eg., setting oif).
Signed-off-by: NDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an inbound message is bigger than a page, allocate a paged SKB,
and subsequently use IUCV receive primitive with IPBUFLST flag.
This relaxes the pressure to allocate big contiguous kernel buffers.
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Before introducing paged skbs in the receive path, get rid of the
function `iucv_fragment_skb()` that replaces one large linear skb
with several smaller linear skbs.
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an outbound message is bigger than a page, allocate and fill
a paged SKB, and subsequently use IUCV send primitive with IPBUFLST
flag. This relaxes the pressure to allocate big contiguous kernel
buffers.
Signed-off-by: NEugene Crosser <Eugene.Crosser@ru.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rework the local RxRPC endpoint management.

Local endpoint objects are maintained in a flat list as before.  This
should be okay as there shouldn't be more than one per open AF_RXRPC socket
(there can be fewer as local endpoints can be shared if their local service
ID is 0 and they share the same local transport parameters).

Changes:

 (1) Local endpoints may now only be shared if they have local service ID 0
     (ie. they're not being used for listening).

     This prevents a scenario where process A is listening of the Cache
     Manager port and process B contacts a fileserver - which may then
     attempt to send CM requests back to B.  But if A and B are sharing a
     local endpoint, A will get the CM requests meant for B.

 (2) We use a mutex to handle lookups and don't provide RCU-only lookups
     since we only expect to access the list when opening a socket or
     destroying an endpoint.

     The local endpoint object is pointed to by the transport socket's
     sk_user_data for the life of the transport socket - allowing us to
     refer to it directly from the sk_data_ready and sk_error_report
     callbacks.

 (3) atomic_inc_not_zero() now exists and can be used to only share a local
     endpoint if the last reference hasn't yet gone.

 (4) We can remove rxrpc_local_lock - a spinlock that had to be taken with
     BH processing disabled given that we assume sk_user_data won't change
     under us.

 (5) The transport socket is shut down before we clear the sk_user_data
     pointer so that we can be sure that the transport socket's callbacks
     won't be invoked once the RCU destruction is scheduled.

 (6) Local endpoints have a work item that handles both destruction and
     event processing.  The means that destruction doesn't then need to
     wait for event processing.  The event queues can then be cleared after
     the transport socket is shut down.

 (7) Local endpoints are no longer available for resurrection beyond the
     life of the sockets that had them open.  As soon as their last ref
     goes, they are scheduled for destruction and may not have their usage
     count moved from 0.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Separate local endpoint event handling out into its own file preparatory to
overhauling the object management aspect (which remains in the original
file).
Signed-off-by: NDavid Howells <dhowells@redhat.com>