In our ongoing effort to simplify the TIPC locking structure,
we see a need to remove the linked list for tipc_links
in the bearer. This can be explained as follows.
Currently, we have three different ways to access a link,
via three different lists/tables:
1: Via a node hash table:
Used by the time-critical outgoing/incoming data paths.
(e.g. link_send_sections_fast() and tipc_recv_msg() ):
grab net_lock(read)
find node from node hash table
grab node_lock
select link
grab bearer_lock
send_msg()
release bearer_lock
release node lock
release net_lock
2: Via a global linked list for nodes:
Used by configuration commands (link_cmd_set_value())
grab net_lock(read)
find node and link from global node list (using link name)
grab node_lock
update link
release node lock
release net_lock
(Same locking order as above. No problem.)
3: Via the bearer's linked link list:
Used by notifications from interface (e.g. tipc_disable_bearer() )
grab net_lock(write)
grab bearer_lock
get link ptr from bearer's link list
get node from link
grab node_lock
delete link
release node lock
release bearer_lock
release net_lock
(Different order from above, but works because we grab the
outer net_lock in write mode first, excluding all other access.)
The first major goal in our simplification effort is to get rid
of the "big" net_lock, replacing it with rcu-locks when accessing
the node list and node hash array. This will come in a later patch
series.
But to get there we first need to rewrite access methods ##2 and 3,
since removal of net_lock would introduce three major problems:
a) In access method #2, we access the link before taking the
protecting node_lock. This will not work once net_lock is gone,
so we will have to change the access order. We will deal with
this in a later commit in this series, "tipc: add node lock
protection to link found by link_find_link()".
b) When the outer protection from net_lock is gone, taking
bearer_lock and node_lock in opposite order of method 1) and 2)
will become an obvious deadlock hazard. This is fixed in the
commit ("tipc: remove bearer_lock from tipc_bearer struct")
later in this series.
c) Similar to what is described in problem a), access method #3
starts with using a link pointer that is unprotected by node_lock,
in order to via that pointer find the correct node struct and
lock it. Before we remove net_lock, this access order must be
altered. This is what we do with this commit.
We can avoid introducing problem problem c) by even here using the
global node list to find the node, before accessing its links. When
we loop though the node list we use the own bearer identity as search
criteria, thus easily finding the links that are associated to the
resetting/disabling bearer. It should be noted that although this
method is somewhat slower than the current list traversal, it is in
no way time critical. This is only about resetting or deleting links,
something that must be considered relatively infrequent events.
As a bonus, we can get rid of the mutual pointers between links and
bearers. After this commit, pointer dependency go in one direction
only: from the link to the bearer.
This commit pre-empts introduction of problem c) as described above.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, the 'started' field in struct tipc_link represents only a
binary state, 'started' or 'not started'. We need it to represent
more link execution states in the coming commits in this series.
Hence, we rename the field to 'flags', and define the current
started/non-started state to be represented by the LSB bit of
that field.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We break out the code for deleting attached links in the
function bearer_disable(), and define a new function named
tipc_link_delete_list() to do this job.
This commit incurs no functional changes, but makes the code of
function bearer_disable() cleaner. It is also a preparation
for a more important change to the bearer code, in a subsequent
commit in this series.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We break out the code for resetting attached links in the
function tipc_reset_bearer(), and define a new function named
tipc_link_reset_list() to do this job.
This commit incurs no functional changes, but makes the code
of function tipc_reset_bearer() cleaner. It is also a preparation
for a more important change to the bearer code, in a subsequent
commit in this series.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The function tipc_link_recv_fragment(struct sk_buff **buf) currently
leaves the value of the input buffer pointer undefined when it returns,
except when the return code indicates that the reassembly is complete.
This despite the fact that it always consumes the input buffer.
Here, we enforce a stricter behavior by this function, ensuring that
the returned buffer pointer is non-NULL if and only if the reassembly
is complete. This makes it possible to test for the buffer pointer as
criteria for successful reassembly.
We also rename the function to tipc_link_frag_rcv(), which is both
shorter and more in line with common naming practice in the network
subsystem.
Apart from the new name, these changes have no impact on current
users of the function, but makes it more practical for use in some
planned future commits.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The inline functions in addr.h uses tipc_own_addr which is exported by
core.h, but addr.h never actually includes it. It works because it is
explicitly included where this is used, but it looks a bit strange.
Include core.h in addr.h explicitly to make the dependency clearer.
Signed-off-by: Andreas Bofjäll <andreas.bofjall@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a packet received on a link is out-of-sequence, it will be
placed on a deferred queue and later reinserted in the receive
path once the preceding packets have been processed. The problem
with this is that it will be subject to the buffer adjustment from
link_recv_buf_validate twice. The second adjustment for 20 bytes
header space will corrupt the packet.
We solve this by tagging the deferred packets and bail out from
receive buffer validation for packets that have already been
subjected to this.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is a follow-up patch to f3d3342602 ("net: rework recvmsg
handler msg_name and msg_namelen logic").
DECLARE_SOCKADDR validates that the structure we use for writing the
name information to is not larger than the buffer which is reserved
for msg->msg_name (which is 128 bytes). Also use DECLARE_SOCKADDR
consistently in sendmsg code paths.
Signed-off-by: Steffen Hurrle <steffen@hurrle.net>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Standardize the behaviour of waiting for events in TIPC recvmsg()
so that all variables of socket or port structures are protected
within socket lock, allowing the process of calling recvmsg() to
be woken up at appropriate time.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Standardize the behaviour of waiting for events in TIPC send_packet()
so that all variables of socket or port structures are protected within
socket lock, allowing the process of calling sendmsg() to be woken up
at appropriate time.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Comparing the behaviour of how to wait for events in TIPC sendmsg()
with other stacks, the TIPC implementation might be perceived as
different, and sometimes even incorrect. For instance, sk_sleep()
and tport->congested variables associated with socket are exposed
without socket lock protection while wait_event_interruptible_timeout()
accesses them. So standardizing it with similar implementation
in other stacks can help us correct these errors which the process
of calling sendmsg() cannot be woken up event if an expected event
arrive at socket or improperly woken up although the wake condition
doesn't match.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Comparing the behaviour of how to wait for events in TIPC accept()
with other stacks, the TIPC implementation might be perceived as
different, and sometimes even incorrect. As sk_sleep() and
sk->sk_receive_queue variables associated with socket are not
protected by socket lock, the process of calling accept() may be
woken up improperly or sometimes cannot be woken up at all. After
standardizing it with inet_csk_wait_for_connect routine, we can
get benefits including: avoiding 'thundering herd' phenomenon,
adding a timeout mechanism for accept(), coping with a pending
signal, and having sk_sleep() and sk->sk_receive_queue being
always protected within socket lock scope and so on.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Comparing the behaviour of how to wait for events in TIPC connect()
with other stacks, the TIPC implementation might be perceived as
different, and sometimes even incorrect. For instance, as both
sock->state and sk_sleep() are directly fed to
wait_event_interruptible_timeout() as its arguments, and socket lock
has to be released before we call wait_event_interruptible_timeout(),
the two variables associated with socket are exposed out of socket
lock protection, thereby probably getting stale values so that the
process of calling connect() cannot be woken up exactly even if
correct event arrives or it is woken up improperly even if the wake
condition is not satisfied in practice. Therefore, standardizing its
behaviour with sk_stream_wait_connect routine can avoid these risks.
Additionally the implementation of connect routine is simplified as a
whole, allowing it to return correct values in all different cases.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a link is created we delay the start event by launching it
to be executed later in a tasklet. As we hold all the
necessary locks at the moment of creation, and there is no risk
of deadlock or contention, this delay serves no purpose in the
current code.
We remove this obsolete indirection step, and the associated function
link_start(). At the same time, we rename the function tipc_link_stop()
to the more appropriate tipc_link_purge_queues().
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, only 'bearer_lock' is used to protect struct link_req in
the function disc_timeout(). This is unsafe, since the member fields
'num_nodes' and 'timer_intv' might be accessed by below three different
threads simultaneously, none of them grabbing bearer_lock in the
critical region:
link_activate()
tipc_bearer_add_dest()
tipc_disc_add_dest()
req->num_nodes++;
tipc_link_reset()
tipc_bearer_remove_dest()
tipc_disc_remove_dest()
req->num_nodes--
disc_update()
read req->num_nodes
write req->timer_intv
disc_timeout()
read req->num_nodes
read/write req->timer_intv
Without lock protection, the only symptom of a race is that discovery
messages occasionally may not be sent out. This is not fatal, since such
messages are best-effort anyway. On the other hand, since discovery
messages are not time critical, adding a protecting lock brings no
serious overhead either. So we add a new, dedicated spinlock in
order to guarantee absolute data consistency in link_req objects.
This also helps reduce the overall role of the bearer_lock, which
we want to remove completely in a later commit series.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The flag 'has_redundant_link' is defined only in RESET and ACTIVATE
protocol messages. Due to an ambiguity in the protocol specification it
is currently also transferred in STATE messages. Its value is used to
initialize a link state variable, 'permit_changeover', which is used
to inhibit futile link failover attempts when it is known that the
peer node has no working links at the moment, although the local node
may still think it has one.
The fact that 'has_redundant_link' incorrectly is read from STATE
messages has the effect that 'permit_changeover' sometimes gets a wrong
value, and permanently blocks any links from being re-established. Such
failures can only occur in in dual-link systems, and are extremely rare.
This bug seems to have always been present in the code.
Furthermore, since commit b4b5610223
("tipc: Ensure both nodes recognize loss of contact between them"),
the 'permit_changeover' field serves no purpose any more. The task of
enforcing 'lost contact' cycles at both peer endpoints is now taken
by a new mechanism, using the flags WAIT_NODE_DOWN and WAIT_PEER_DOWN
in struct tipc_node to abort unnecessary failover attempts.
We therefore remove the 'has_redundant_link' flag from STATE messages,
as well as the now redundant 'permit_changeover' variable.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The functionality related to link addition and failover is unnecessarily
hard to understand and maintain. We try to improve this by renaming
some of the functions, at the same time adding or improving the
explanatory comments around them. Names such as "tipc_rcv()" etc. also
align better with what is used in other networking components.
The changes in this commit are purely cosmetic, no functional changes
are made.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we pull a received packet from a link's 'deferred packets' queue
for processing, its 'next' pointer is not cleared, and still refers to
the next packet in that queue, if any. This is incorrect, but caused
no harm before commit 40ba3cdf54 ("tipc:
message reassembly using fragment chain") was introduced. After that
commit, it may sometimes lead to the following oops:
general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC
Modules linked in: tipc
CPU: 4 PID: 0 Comm: swapper/4 Tainted: G W 3.13.0-rc2+ #6
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
task: ffff880017af4880 ti: ffff880017aee000 task.ti: ffff880017aee000
RIP: 0010:[<ffffffff81710694>] [<ffffffff81710694>] skb_try_coalesce+0x44/0x3d0
RSP: 0018:ffff880016603a78 EFLAGS: 00010212
RAX: 6b6b6b6bd6d6d6d6 RBX: ffff880013106ac0 RCX: ffff880016603ad0
RDX: ffff880016603ad7 RSI: ffff88001223ed00 RDI: ffff880013106ac0
RBP: ffff880016603ab8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff88001223ed00
R13: ffff880016603ad0 R14: 000000000000058c R15: ffff880012297650
FS: 0000000000000000(0000) GS:ffff880016600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 000000000805b000 CR3: 0000000011f5d000 CR4: 00000000000006e0
Stack:
ffff880016603a88 ffffffff810a38ed ffff880016603aa8 ffff88001223ed00
0000000000000001 ffff880012297648 ffff880016603b68 ffff880012297650
ffff880016603b08 ffffffffa0006c51 ffff880016603b08 00ffffffa00005fc
Call Trace:
<IRQ>
[<ffffffff810a38ed>] ? trace_hardirqs_on+0xd/0x10
[<ffffffffa0006c51>] tipc_link_recv_fragment+0xd1/0x1b0 [tipc]
[<ffffffffa0007214>] tipc_recv_msg+0x4e4/0x920 [tipc]
[<ffffffffa00016f0>] ? tipc_l2_rcv_msg+0x40/0x250 [tipc]
[<ffffffffa000177c>] tipc_l2_rcv_msg+0xcc/0x250 [tipc]
[<ffffffffa00016f0>] ? tipc_l2_rcv_msg+0x40/0x250 [tipc]
[<ffffffff8171e65b>] __netif_receive_skb_core+0x80b/0xd00
[<ffffffff8171df94>] ? __netif_receive_skb_core+0x144/0xd00
[<ffffffff8171eb76>] __netif_receive_skb+0x26/0x70
[<ffffffff8171ed6d>] netif_receive_skb+0x2d/0x200
[<ffffffff8171fe70>] napi_gro_receive+0xb0/0x130
[<ffffffff815647c2>] e1000_clean_rx_irq+0x2c2/0x530
[<ffffffff81565986>] e1000_clean+0x266/0x9c0
[<ffffffff81985f7b>] ? notifier_call_chain+0x2b/0x160
[<ffffffff8171f971>] net_rx_action+0x141/0x310
[<ffffffff81051c1b>] __do_softirq+0xeb/0x480
[<ffffffff819817bb>] ? _raw_spin_unlock+0x2b/0x40
[<ffffffff810b8c42>] ? handle_fasteoi_irq+0x72/0x100
[<ffffffff81052346>] irq_exit+0x96/0xc0
[<ffffffff8198cbc3>] do_IRQ+0x63/0xe0
[<ffffffff81981def>] common_interrupt+0x6f/0x6f
<EOI>
This happens when the last fragment of a message has passed through the
the receiving link's 'deferred packets' queue, and at least one other
packet was added to that queue while it was there. After the fragment
chain with the complete message has been successfully delivered to the
receiving socket, it is released. Since 'next' pointer of the last
fragment in the released chain now is non-NULL, we get the crash shown
above.
We fix this by clearing the 'next' pointer of all received packets,
including those being pulled from the 'deferred' queue, before they
undergo any further processing.
Fixes: 40ba3cdf54 ("tipc: message reassembly using fragment chain")
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reported-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c
net/ipv6/ip6_tunnel.c
net/ipv6/ip6_vti.c
ipv6 tunnel statistic bug fixes conflicting with consolidation into
generic sw per-cpu net stats.
qlogic conflict between queue counting bug fix and the addition
of multiple MAC address support.
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove dead code;
tipc_bearer_find_interface
tipc_node_redundant_links
This may break out of tree version of TIPC if there still is one.
But that maybe a good thing :-)
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In commit 3b8401fe9d ("tipc: kill unnecessary goto's") didn't make
the code look most readable, so fix it. This patch is cosmetic
and does not change the operation of TIPC in any way.
Suggested-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A deadlock might occur if name table is withdrawn in socket release
routine, and while packets are still being received from bearer.
CPU0 CPU1
T0: recv_msg() release()
T1: tipc_recv_msg() tipc_withdraw()
T2: [grab node lock] [grab port lock]
T3: tipc_link_wakeup_ports() tipc_nametbl_withdraw()
T4: [grab port lock]* named_cluster_distribute()
T5: wakeupdispatch() tipc_link_send()
T6: [grab node lock]*
The opposite order of holding port lock and node lock on above two
different paths may result in a deadlock. If socket lock instead of
port lock is used to protect port instance in tipc_withdraw(), the
reverse order of holding port lock and node lock will be eliminated,
as a result, the deadlock is killed as well.
Reported-by: Lars Everbrand <lars.everbrand@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/intel/i40e/i40e_main.c
drivers/net/macvtap.c
Both minor merge hassles, simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of reaquiring the socket lock and taking the normal exit
path when a connection times out, we bail out early with a
return -ETIMEDOUT.
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As warned by checkpatch.pl, use #include <linux/uaccess.h>
instead of <asm/uaccess.h>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove a number of needless 'goto exit' in send_stream
when the socket is in an unconnected state.
This patch is cosmetic and does not alter the operation of
TIPC in any way.
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We remove a number of unnecessary variables and branches
in TIPC. This patch is cosmetic and does not change the
operation of TIPC in any way.
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In early versions of TIPC it was possible to administratively block
individual links through the use of the member flag 'blocked'. This
functionality was deemed redundant, and since commit 7368dd ("tipc:
clean out all instances of #if 0'd unused code"), this flag has been
unused.
In the current code, a link only needs to be blocked for sending and
reception if it is subject to an ongoing link failover. In that case,
it is sufficient to check if the number of expected failover packets
is non-zero, something which is done via the funtion 'link_blocked()'.
This commit finally removes the redundant 'blocked' flag completely.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently TIPC supports two L2 media types, Ethernet and Infiniband.
Because both these media are accessed through the common net_device API,
several functions in the two media adaptation files turn out to be
fully or almost identical, leading to unnecessary code duplication.
In this commit we extract this common code from the two media files
and move them to the generic bearer.c. Additionally, we change
the function names to reflect their real role: to access L2 media,
irrespective of type.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Patrick McHardy <kaber@trash.net>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, registering a TIPC stack handler in the network device layer
is done twice, once for Ethernet (eth_media) and Infiniband (ib_media)
repectively. But, as this registration is not media specific, we can
avoid some code duplication by moving the registering function to
the generic bearer layer, to the file bearer.c, and call it only once.
The same is true for the network device event notifier.
As a side effect, the two workqueues we are using for for setting up/
cleaning up media can now be eliminated. Furthermore, the array for
storing the specific media type structs, media_array[], can be entirely
deleted.
Note that the eth_started and ib_started flags were removed during the
code relocation. There is now only one call to bearer_setup and
bearer_cleanup, and these can logically not race against each other.
Despite its size, this cleanup work incurs no functional changes in TIPC.
In particular, it should be noted that the sequence ordering of received
packets is unaffected by this change, since packet reception never was
subject to any work queue handling in the first place.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TIPC is currently using the field 'af_packet_priv' in struct net_device
as a handle to find the bearer instance associated to the given network
device. But, by doing so it is blocking other networking cleanups, such
as the one discussed here:
http://patchwork.ozlabs.org/patch/178044/
This commit removes this usage from TIPC. Instead, we introduce a new
field, 'tipc_ptr', to the net_device structure, to serve this purpose.
When TIPC bearer is enabled, the bearer object is associated to
'tipc_ptr'. When a TIPC packet arrives in the recv_msg() upcall
from a networking device, the bearer object can now be obtained from
'tipc_ptr'. When a bearer is disabled, the bearer object is detached
from its underlying network device by setting 'tipc_ptr' to NULL.
Additionally, an RCU lock is used to protect the new pointer.
Henceforth, the existing tipc_net_lock is used in write mode to
serialize write accesses to this pointer, while the new RCU lock is
applied on the read side to ensure that the pointer is 100% valid
within its wrapped area for all readers.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Patrick McHardy <kaber@trash.net>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct 'tipc_media' represents the specific info that the media
layer adaptors (eth_media and ib_media) expose to the generic
bearer layer. We clarify this by improved commenting, and by giving
the 'media_list' array the more appropriate name 'media_info_array'.
There are no functional changes in this commit.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Communication media types are abstracted through the struct 'tipc_media',
one per media type. These structs are allocated statically inside their
respective media file.
Furthermore, in order to be able to reach all instances from a central
location, we keep a static array with pointers to these structs. This
array is currently initialized at runtime, under protection of
tipc_net_lock. However, since the contents of the array itself never
changes after initialization, we can just as well initialize it at
compile time and make it 'const', at the same time making it obvious
that no lock protection is needed here.
This commit makes the array constant and removes the redundant lock
protection.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sk_buff lists are currently relased by looping over the list and
explicitly releasing each buffer.
We replace all occurrences of this loop with a call to kfree_skb_list().
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
'handler_enabled' is a global flag indicating whether the TIPC
signal handling service is enabled or not. The lack of lock
protection for this flag incurs a risk for contention, so that
a tipc_k_signal() call might queue a signal handler to a destroyed
signal queue, with unpredictable results. To correct this, we let
the already existing 'qitem_lock' protect the flag, as it already
does with the queue itself. This way, we ensure that the flag
always is consistent across all cores.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 'signal handler' service in TIPC is a mechanism that makes it
possible to postpone execution of functions, by launcing them into
a job queue for execution in a separate tasklet, independent of
the launching execution thread.
When we do rmmod on the tipc module, this service is stopped after
the network service. At the same time, the stopping of the network
service may itself launch jobs for execution, with the risk that these
functions may be scheduled for execution after the data structures
meant to be accessed by the job have already been deleted. We have
seen this happen, most often resulting in an oops.
This commit ensures that the signal handler is the very first to be
stopped when TIPC is shut down, so there are no surprises during
the cleanup of the other services.
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
struct 'tipc_bearer' is a generic representation of the underlying
media type, and exists in a one-to-one relationship to each interface
TIPC is using. The struct contains a 'blocked' flag that mirrors the
operational and execution state of the represented interface, and is
updated through notification calls from the latter. The users of
tipc_bearer are checking this flag before each attempt to send a
packet via the interface.
This state mirroring serves no purpose in the current code base. TIPC
links will not discover a media failure any faster through this
mechanism, and in reality the flag only adds overhead at packet
sending and reception.
Furthermore, the fact that the flag needs to be protected by a spinlock
aggregated into tipc_bearer has turned out to cause a serious and
completely unnecessary deadlock problem.
CPU0 CPU1
---- ----
Time 0: bearer_disable() link_timeout()
Time 1: spin_lock_bh(&b_ptr->lock) tipc_link_push_queue()
Time 2: tipc_link_delete() tipc_bearer_blocked(b_ptr)
Time 3: k_cancel_timer(&req->timer) spin_lock_bh(&b_ptr->lock)
Time 4: del_timer_sync(&req->timer)
I.e., del_timer_sync() on CPU0 never returns, because the timer handler
on CPU1 is waiting for the bearer lock.
We eliminate the 'blocked' flag from struct tipc_bearer, along with all
tests on this flag. This not only resolves the deadlock, but also
simplifies and speeds up the data path execution of TIPC. It also fits
well into our ongoing effort to make the locking policy simpler and
more manageable.
An effect of this change is that we can get rid of functions such as
tipc_bearer_blocked(), tipc_continue() and tipc_block_bearer().
We replace the latter with a new function, tipc_reset_bearer(), which
resets all links associated to the bearer immediately after an
interface goes down.
A user might notice one slight change in link behaviour after this
change. When an interface goes down, (e.g. through a NETDEV_DOWN
event) all attached links will be reset immediately, instead of
leaving it to each link to detect the failure through a timer-driven
mechanism. We consider this an improvement, and see no obvious risks
with the new behavior.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <Paul.Gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
As suggested by David Miller, make genl_register_family_with_ops()
a macro and pass only the array, evaluating ARRAY_SIZE() in the
macro, this is a little safer.
The openvswitch has some indirection, assing ops/n_ops directly in
that code. This might ultimately just assign the pointers in the
family initializations, saving the struct genl_family_and_ops and
code (once mcast groups are handled differently.)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes the following Smatch warning:
net/tipc/link.c:2364 tipc_link_recv_fragment()
warn: variable dereferenced before check '*head' (see line 2361)
A null pointer might be passed to skb_try_coalesce if
a malicious sender injects orphan fragments on a link.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If appending a received fragment to the pending fragment chain
in a unicast link fails, the current code tries to force a retransmission
of the fragment by decrementing the 'next received sequence number'
field in the link. This is done under the assumption that the failure
is caused by an out-of-memory situation, an assumption that does
not hold true after the previous patch in this series.
A failure to append a fragment can now only be caused by a protocol
violation by the sending peer, and it must hence be assumed that it
is either malicious or buggy. Either way, the correct behavior is now
to reset the link instead of trying to revert its sequence number.
So, this is what we do in this commit.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the first fragment of a long data data message is received on a link, a
reassembly buffer large enough to hold the data from this and all subsequent
fragments of the message is allocated. The payload of each new fragment is
copied into this buffer upon arrival. When the last fragment is received, the
reassembled message is delivered upwards to the port/socket layer.
Not only is this an inefficient approach, but it may also cause bursts of
reassembly failures in low memory situations. since we may fail to allocate
the necessary large buffer in the first place. Furthermore, after 100 subsequent
such failures the link will be reset, something that in reality aggravates the
situation.
To remedy this problem, this patch introduces a different approach. Instead of
allocating a big reassembly buffer, we now append the arriving fragments
to a reassembly chain on the link, and deliver the whole chain up to the
socket layer once the last fragment has been received. This is safe because
the retransmission layer of a TIPC link always delivers packets in strict
uninterrupted order, to the reassembly layer as to all other upper layers.
Hence there can never be more than one fragment chain pending reassembly at
any given time in a link, and we can trust (but still verify) that the
fragments will be chained up in the correct order.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a message fragment is received in a broadcast or unicast link,
the reception code will append the fragment payload to a big reassembly
buffer through a call to the function tipc_recv_fragm(). However, after
the return of that call, the logics goes on and passes the fragment
buffer to the function tipc_net_route_msg(), which will simply drop it.
This behavior is a remnant from the now obsolete multi-cluster
functionality, and has no relevance in the current code base.
Although currently harmless, this unnecessary call would be fatal
after applying the next patch in this series, which introduces
a completely new reassembly algorithm. So we change the code to
eliminate the redundant call.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The message dispatching part of tipc_recv_msg() is wrapped layers of
while/if/if/switch, causing out-of-control indentation and does not
look very good. We reduce two indentation levels by separating the
message dispatching from the blocks that checks link state and
sequence numbers, allowing longer function and arg names to be
consistently indented without wrapping. Additionally we also rename
"cont" label to "discard" and add one new label called "unlock_discard"
to make code clearer. In all, these are cosmetic changes that do not
alter the operation of TIPC in any way.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Cc: David Laight <david.laight@aculab.com>
Cc: Andreas Bofjäll <andreas.bofjall@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are a mix of function prototypes with and without extern
in the kernel sources. Standardize on not using extern for
function prototypes.
Function prototypes don't need to be written with extern.
extern is assumed by the compiler. Its use is as unnecessary as
using auto to declare automatic/local variables in a block.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When checking statistics or changing parameters on a link, the
link_find_link function is used to locate the link with a given
name. The complex method of deconstructing the name into local
and remote address/interface is error prone and may fail if the
interface names contains special characters. We change the lookup
method to iterate over the list of nodes and compare the link
names.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
link_cmd_set_value() takes commands for link, bearer and media related
configuration. Genereally the function returns 0 when a command is
recognized, and -EINVAL when it is not. However, in the switch for link
related commands it returns 0 even when the command is unrecognized. This
will sometimes make it look as if a failed configuration command has been
successful, but has otherwise no negative effects.
We remove this anomaly by returning -EINVAL even for link commands. We also
rework all three switches to make them conforming to common kernel coding
style.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, rcv_msg() always returns zero on a packet delivery upcall
from net_device.
To make its behavior more compliant with the way this API should be
used, we change this to let it return NET_RX_SUCCESS (which is zero
anyway) when it is able to handle the packet, and NET_RX_DROP otherwise.
The latter does not imply any functional change, it only enables the
driver to keep more accurate statistics about the fate of delivered
packets.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tipc_block_bearer() currently takes a bearer name (const char*)
as argument. This requires the function to make a lookup to find
the pointer to the corresponding bearer struct. In the current
code base this is not necessary, since the only two callers
(tipc_continue(),recv_notification()) already have validated
copies of this pointer, and hence can pass it directly in the
function call.
We change tipc_block_bearer() to directly take struct tipc_bearer*
as argument instead.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TIPC 'bearer' exists as an abstract concept, while 'media'
is deemed a specific implementation of a bearer, such as Ethernet
or Infiniband media. When a component inside TIPC wants to control
a specific media, it only needs to access the generic bearer API
to achieve this. However, in the current media implementations,
the 'bearer' name is also extensively used in media specific
function and variable names.
This may create confusion, so we choose to replace the term 'bearer'
with 'media' in all function names, variable names, and prefixes
where this is what really is meant.
Note that this change is cosmetic only, and no runtime behaviour
changes are made here.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tipc_msg_build() now copies message data from iovec to skb_buff
using memcpy_fromiovecend(), which doesn't need to be passed the
iovec length to perform the copying.
So we remove the parameter indicating iovec length in all
functions where TIPC messages are built and sent.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tipc_msg_build() calls skb_copy_to_linear_data_offset() to copy data
from user space to kernel space. However, the latter function does
in its turn call memcpy() to perform the actual copying. This poses
an obvious security and robustness risk, since memcpy() never makes
any validity check on the pointer it is copying from.
To correct this, we the replace the offending function call with
a call to memcpy_fromiovecend(), which uses copy_from_user() to
perform the copying.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Should a connect fail, if the publication/server is unavailable or
due to some other error, a positive value will be returned and errno
is never set. If the application code checks for an explicit zero
return from connect (success) or a negative return (failure), it
will not catch the error and subsequent send() calls will fail as
shown from the strace snippet below.
socket(0x1e /* PF_??? */, SOCK_SEQPACKET, 0) = 3
connect(3, {sa_family=0x1e /* AF_??? */, sa_data="\2\1\322\4\0\0\322\4\0\0\0\0\0\0"}, 16) = 111
sendto(3, "test", 4, 0, NULL, 0) = -1 EPIPE (Broken pipe)
The reason for this behaviour is that TIPC wrongly inverts error
codes set in sk_err.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of passing each byte by stack let's use nice specifier for that.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Convert enable_bearer() to RCU locking with dev_get_by_name().
Based on a similar changeset in commit 840a185d ["aoe: remove
dev_base_lock use from aoecmd_cfg_pkts()"] -- quoting that:
"dev_base_lock is the legacy way to lock the device list,
and is planned to disappear. (writers hold RTNL, readers
hold RCU lock)"
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When skb buffer cannot be allocated in link_send_sections_long(),
-ENOMEM error code instead of -EFAULT should be returned to its
caller.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Once message build request function returns invalid code, the
process of sending message cannot continue. So in case of message
build failure, tipc_link_send_sections_fast() should return
immediately.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
pfifo_fast is set as default traffic class queueing discipline. This
queue has three so called "bands". Within each band, FIFO rules apply.
However, as long as there are packets waiting in band 0, band 1 won't
be processed.
Now all kind of TIPC type packet priorities are never set, that is,
their priorities are 0, so they are mapped to band 1 of pfifo_fast
qdisc. But, especially during link congestion, if link protocol packet
can be sent out as earlier as possible than other type of packets so
that protocol packet can arrive at peer endpoint in time, the peer
will timely reset its link timeout timer to keep the link alive.
So enhancing the priority of link protocol packets can meet the
specific demand to avoid unnecessary link reset due to a transient
link congestion.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
No runtime code changes here. Just a realign of the function
arguments to start where the 1st one was, and fit as many args
as can be put in an 80 char line.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Directly save sock structure pointer instead of void pointer to avoid
unnecessary cast conversions.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the configuration server is now running under process context,
it's unnecessary for us to have a spinlock serializing the TIPC
configuration process. Instead, we replace it with a mutex lock,
which gives us more freedom. For instance, we can now call
pre-emptable functions within the protected area.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After the removal of the native API, there is now only one way to
to create a TIPC port instance -- the function tipc_createport_raw().
We make it more readable by renaming it to tipc_createport().
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After the native API has been completely removed, the 'user_port'
field in struct tipc_port becomes unused, and can be removed.
As a consequence, the "usrmem" argument in tipc_msg_build() is no
longer needed, and so we remove that one too.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Having completed the conversion of the topology server and
configuration server to use the new server infrastructure,
the following functions become unused, and can be deleted:
- tipc_createport()
- port_wakeup_sh()
- port_dispatcher()
- port_dispatcher_sigh()
- tipc_send_buf_fast()
- tipc_send_buf2port
Additionally, the following variables become orphaned,
and can be deleted:
- tipc_msg_err_event
- tipc_named_msg_err_event
- tipc_conn_shutdown_event
- tipc_msg_event
- tipc_named_msg_event
- tipc_conn_msg_event
- tipc_continue_event
- msg_queue_head
- msg_queue_tail
- queue_lock
Deletion is done here in a separate commit in order to allow
the actual conversion changes to be more easily viewed.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the new socket-based TIPC server infrastructure has been
introduced, we can now convert the configuration server to use
it. Then we can take future steps to simplify the configuration
server locking policy.
Some minor reordering of initialization is done, due to the
dependency on having tipc_socket_init completed.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As the new TIPC server infrastructure has been introduced, we can
now convert the TIPC topology server to it. We get two benefits
from doing this:
1) It simplifies the topology server locking policy. In the
original locking policy, we placed one spin lock pointer in the
tipc_subscriber structure to reuse the lock of the subscriber's
server port, controlling access to members of tipc_subscriber
instance. That is, we only used one lock to ensure both
tipc_port and tipc_subscriber members were safely accessed.
Now we introduce another spin lock for tipc_subscriber structure
only protecting themselves, to get a finer granularity locking
policy. Moreover, the change will allow us to make the topology
server code more readable and maintainable.
2) It fixes a bug where sent subscription events may be lost when
the topology port is congested. Using the new service, the
topology server now queues sent events into an outgoing buffer,
and then wakes up a sender process which has been blocked in
workqueue context. The process will keep picking events from the
buffer and send them to their respective subscribers, using the
kernel socket interface, until the buffer is empty. Even if the
socket is congested during transmission there is no risk that
events may be dropped, since the sender process may block when
needed.
Some minor reordering of initialization is done, since we now
have a scenario where the topology server must be started after
socket initialization has taken place, as the former depends
on the latter. And overall, we see a simplification of the
TIPC subscriber code in making this changeover.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TIPC has two internal servers, one providing a subscription
service for topology events, and another providing the
configuration interface. These servers have previously been running
in BH context, accessing the TIPC-port (aka native) API directly.
Apart from these servers, even the TIPC socket implementation is
partially built on this API.
As this API may simultaneously be called via different paths and in
different contexts, a complex and costly lock policiy is required
in order to protect TIPC internal resources.
To eliminate the need for this complex lock policiy, we introduce
a new, generic service API that uses kernel sockets for message
passing instead of the native API. Once the toplogy and configuration
servers are converted to use this new service, all code pertaining
to the native API can be removed. This entails a significant
reduction in code amount and complexity, and opens up for a complete
rework of the locking policy in TIPC.
The new service also solves another problem:
As the current topology server works in BH context, it cannot easily
be blocked when sending of events fails due to congestion. In such
cases events may have to be silently dropped, something that is
unacceptable. Therefore, the new service keeps a dedicated outbound
queue receiving messages from BH context. Once messages are
inserted into this queue, we will immediately schedule a work from a
special workqueue. This way, messages/events from the topology server
are in reality sent in process context, and the server can block
if necessary.
Analogously, there is a new workqueue for receiving messages. Once a
notification about an arriving message is received in BH context, we
schedule a work from the receive workqueue to do the job of
receiving the message in process context.
As both sending and receive messages are now finished in processes,
subscribed events cannot be dropped any more.
As of this commit, this new server infrastructure is built, but
not actually yet called by the existing TIPC code, but since the
conversion changes required in order to use it are significant,
the addition is kept here as a separate commit.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
TIPC's implied connect feature, aka piggyback connect, allows
applications to save one syscall and all SYN/SYN-ACK signalling
overhead when setting up a connection. Until now, this has only
been supported for SEQPACKET sockets. Here, we make it possible
to use this feature even with stream sockets.
At the connecting side, the connection is completed when the
first data message arrives from the accepting peer. This means
that we must allow the connecting user to call blocking recv()
before the socket has reached state SS_CONNECTED. So we must must
relax the state machine check at recv_stream(), and allow the
recv() call even if socket is in state SS_CONNECTING.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As per feedback from the netdev community, we change the buffer
overflow protection algorithm in receiving sockets so that it
always respects the nominal upper limit set in sk_rcvbuf.
Instead of scaling up from a small sk_rcvbuf value, which leads to
violation of the configured sk_rcvbuf limit, we now calculate the
weighted per-message limit by scaling down from a much bigger value,
still in the same field, according to the importance priority of the
received message.
To allow for administrative tunability of the socket receive buffer
size, we create a tipc_rmem sysctl variable to allow the user to
configure an even bigger value via sysctl command. It is a size of
three (min/default/max) to be consistent with things like tcp_rmem.
By default, the value initialized in tipc_rmem[1] is equal to the
receive socket size needed by a TIPC_CRITICAL_IMPORTANCE message.
This value is also set as the default value of sk_rcvbuf.
Originally-by: Jon Maloy <jon.maloy@ericsson.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
[Ying: added sysctl variation to Jon's original patch]
Signed-off-by: Ying Xue <ying.xue@windriver.com>
[PG: don't compile sysctl.c if not config'd; add Documentation]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
So far, only net_device * could be passed along with netdevice notifier
event. This patch provides a possibility to pass custom structure
able to provide info that event listener needs to know.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
v2->v3: fix typo on simeth
shortened dev_getter
shortened notifier_info struct name
v1->v2: fix notifier_call parameter in call_netdevice_notifier()
Signed-off-by: David S. Miller <davem@davemloft.net>
The worry here is that fragm_sz could be zero since it comes from
skb->data.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The bearer_id here comes from skb->data and it can be a number from 0 to
7. The problem is that the ->links[] array has only 2 elements so I
have added a range check.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When sending packets, TIPC bearers use skb_clone() before writing their
hardware header. This will however NOT copy the data buffer.
So when the same packet is sent over multiple bearers (to reach multiple
nodes), the same socket buffer data will be treated by multiple
tipc_media drivers which will write their own hardware header through
dev_hard_header().
Most of the time this is not a problem, because by the time the
packet is processed by the second media, it has already been sent over
the first one. However, when the first transmission is delayed (e.g.
because of insufficient bandwidth or through a shaper), the next bearer
will overwrite the hardware header, resulting in the packet being sent:
a) with the wrong source address, when bearers of the same type,
e.g. ethernet, are involved
b) with a completely corrupt header, or even dropped, when bearers of
different types are involved.
So when the same socket buffer is to be sent multiple times, send a
pskb_copy() instead (from the second instance on), and release it
afterwards (the bearer will skb_clone() it anyway).
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add InfiniBand media type based on the ethernet media type.
The only real difference is that in case of InfiniBand, we need the entire
20 bytes of space reserved for media addresses, so the TIPC media type ID is
not explicitly stored in the packet payload.
Sample output of tipc-config:
# tipc-config -v -addr -netid -nt=all -p -m -b -n -ls
node address: <10.1.4>
current network id: 4711
Type Lower Upper Port Identity Publication Scope
0 167776257 167776257 <10.1.1:1855512577> 1855512578 cluster
167776260 167776260 <10.1.4:1216454657> 1216454658 zone
1 1 1 <10.1.4:1216479235> 1216479236 node
Ports:
1216479235: bound to {1,1}
1216454657: bound to {0,167776260}
Media:
eth
ib
Bearers:
ib:ib0
Nodes known:
<10.1.1>: up
Link <broadcast-link>
Window:20 packets
RX packets:0 fragments:0/0 bundles:0/0
TX packets:0 fragments:0/0 bundles:0/0
RX naks:0 defs:0 dups:0
TX naks:0 acks:0 dups:0
Congestion bearer:0 link:0 Send queue max:0 avg:0
Link <10.1.4:ib0-10.1.1:ib0>
ACTIVE MTU:2044 Priority:10 Tolerance:1500 ms Window:50 packets
RX packets:80 fragments:0/0 bundles:0/0
TX packets:40 fragments:0/0 bundles:0/0
TX profile sample:22 packets average:54 octets
0-64:100% -256:0% -1024:0% -4096:0% -16384:0% -32768:0% -66000:0%
RX states:410 probes:213 naks:0 defs:0 dups:0
TX states:410 probes:197 naks:0 acks:0 dups:0
Congestion bearer:0 link:0 Send queue max:1 avg:0
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The skb->protocol field is used by packet classifiers and for AF_PACKET
cooked format, TIPC needs to set it properly.
Fixes packet classification and ethertype of 0x0000 in cooked captures:
Out 20:c9:d0:43:12:d9 ethertype Unknown (0x0000), length 56:
0x0000: 5b50 0028 0000 30d4 0100 1000 0100 1001 [P.(..0.........
0x0010: 0000 03e8 0000 0001 20c9 d043 12d9 0000 ...........C....
0x0020: 0000 0000 0000 0000 ........
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some network protocols, like InfiniBand, don't have a fixed broadcast
address but one that depends on the configuration. Move the bcast_addr
to struct tipc_bearer and initialize it with the broadcast address of
the network device when the bearer is enabled.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/nfc/microread/mei.c
net/netfilter/nfnetlink_queue_core.c
Pull in 'net' to get Eric Biederman's AF_UNIX fix, upon which
some cleanups are going to go on-top.
Signed-off-by: David S. Miller <davem@davemloft.net>
The code in set_orig_addr() does not initialize all of the members of
struct sockaddr_tipc when filling the sockaddr info -- namely the union
is only partly filled. This will make recv_msg() and recv_stream() --
the only users of this function -- leak kernel stack memory as the
msg_name member is a local variable in net/socket.c.
Additionally to that both recv_msg() and recv_stream() fail to update
the msg_namelen member to 0 while otherwise returning with 0, i.e.
"success". This is the case for, e.g., non-blocking sockets. This will
lead to a 128 byte kernel stack leak in net/socket.c.
Fix the first issue by initializing the memory of the union with
memset(0). Fix the second one by setting msg_namelen to 0 early as it
will be updated later if we're going to fill the msg_name member.
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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>
Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers all
over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
If you need me to provide a merged tree to handle these resolutions,
please let me know.
Other than those patches, there's not much here, some minor fixes and
updates.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core patches from Greg Kroah-Hartman:
"Here is the big driver core merge for 3.9-rc1
There are two major series here, both of which touch lots of drivers
all over the kernel, and will cause you some merge conflicts:
- add a new function called devm_ioremap_resource() to properly be
able to check return values.
- remove CONFIG_EXPERIMENTAL
Other than those patches, there's not much here, some minor fixes and
updates"
Fix up trivial conflicts
* tag 'driver-core-3.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (221 commits)
base: memory: fix soft/hard_offline_page permissions
drivercore: Fix ordering between deferred_probe and exiting initcalls
backlight: fix class_find_device() arguments
TTY: mark tty_get_device call with the proper const values
driver-core: constify data for class_find_device()
firmware: Ignore abort check when no user-helper is used
firmware: Reduce ifdef CONFIG_FW_LOADER_USER_HELPER
firmware: Make user-mode helper optional
firmware: Refactoring for splitting user-mode helper code
Driver core: treat unregistered bus_types as having no devices
watchdog: Convert to devm_ioremap_resource()
thermal: Convert to devm_ioremap_resource()
spi: Convert to devm_ioremap_resource()
power: Convert to devm_ioremap_resource()
mtd: Convert to devm_ioremap_resource()
mmc: Convert to devm_ioremap_resource()
mfd: Convert to devm_ioremap_resource()
media: Convert to devm_ioremap_resource()
iommu: Convert to devm_ioremap_resource()
drm: Convert to devm_ioremap_resource()
...
Pull in 'net' to take in the bug fixes that didn't make it into
3.8-final.
Also, deal with the semantic conflict of the change made to
net/ipv6/xfrm6_policy.c A missing rt6->n neighbour release
was added to 'net', but in 'net-next' we no longer cache the
neighbour entries in the ipv6 routes so that change is not
appropriate there.
Signed-off-by: David S. Miller <davem@davemloft.net>
As the number of iovecs in a send request is already limited within
UIO_MAXIOV(i.e. 1024) in __sys_sendmsg(), it's unnecessary to check it
again in TIPC stack.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Change overload control to be purely byte-based, using
sk->sk_rmem_alloc as byte counter, and compare it to a calculated
upper limit for the socket receive queue.
For all connection messages, irrespective of message importance,
the overload limit is set to a constant value (i.e, 67MB). This
limit should normally never be reached because of the lower
limit used by the flow control algorithm, and is there only
as a last resort in case a faulty peer doesn't respect the send
window limit.
For datagram messages, message importance is taken into account
when calculating the overload limit. The calculation is based
on sk->sk_rcvbuf, and is hence configurable via the socket option
SO_RCVBUF.
Cc: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The tipc function discard_rx_queue() is just a duplicated
implementation of __skb_queue_purge(). Remove the former
and directly invoke __skb_queue_purge().
In doing so, the underscores convey to the code reader, more
information about the current locking state that is assumed.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
After commit 3c294cb3 "tipc: remove the bearer congestion mechanism",
we try to grab the broadcast bearer lock when sending multicast
messages over the broadcast link. This will cause an oops because
the lock is never initialized. This is an old bug, but the lock
was never actually used before commit 3c294cb3, so that why it was
not visible until now. The oops will look something like:
BUG: spinlock bad magic on CPU#2, daemon/147
lock: bcast_bearer+0x48/0xffffffffffffd19a [tipc],
.magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
Pid: 147, comm: daemon Not tainted 3.8.0-rc3+ #206
Call Trace:
spin_dump+0x8a/0x8f
spin_bug+0x21/0x26
do_raw_spin_lock+0x114/0x150
_raw_spin_lock_bh+0x19/0x20
tipc_bearer_blocked+0x1f/0x40 [tipc]
tipc_link_send_buf+0x82/0x280 [tipc]
? __alloc_skb+0x9f/0x2b0
tipc_bclink_send_msg+0x77/0xa0 [tipc]
tipc_multicast+0x11b/0x1b0 [tipc]
send_msg+0x225/0x530 [tipc]
sock_sendmsg+0xca/0xe0
The above can be triggered by running the multicast demo program.
Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The CONFIG_EXPERIMENTAL config item has not carried much meaning for a
while now and is almost always enabled by default. As agreed during the
Linux kernel summit, remove it from any "depends on" lines in Kconfigs.
CC: Jon Maloy <jon.maloy@ericsson.com>
CC: Allan Stephens <allan.stephens@windriver.com>
CC: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: David S. Miller <davem@davemloft.net>
In TIPC's accept() routine, there is a large block of code relating
to initialization of a new socket, all within an if condition checking
if the allocation succeeded.
Here, we simply flip the check of the if, so that the main execution
path stays at the same indentation level, which improves readability.
If the allocation fails, we jump to an already existing exit label.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
TIPC accept() call grabs the socket lock on a newly allocated
socket while holding the socket lock on an old socket. But lockdep
worries that this might be a recursive lock attempt:
[ INFO: possible recursive locking detected ]
---------------------------------------------
kworker/u:0/6 is trying to acquire lock:
(sk_lock-AF_TIPC){+.+.+.}, at: [<c8c1226c>] accept+0x15c/0x310 [tipc]
but task is already holding lock:
(sk_lock-AF_TIPC){+.+.+.}, at: [<c8c12138>] accept+0x28/0x310 [tipc]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(sk_lock-AF_TIPC);
lock(sk_lock-AF_TIPC);
*** DEADLOCK ***
May be due to missing lock nesting notation
[...]
Tell lockdep that this locking is safe by using lock_sock_nested().
This is similar to what was done in commit 5131a184a3 for
SCTP code ("SCTP: lock_sock_nested in sctp_sock_migrate").
Also note that this is isn't something that is seen normally,
as it was uncovered with some experimental work-in-progress
code not yet ready for mainline. So no need for stable
backports or similar of this commit.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
As connection setup is now completed asynchronously in BH context,
in the function filter_connect(), the corresponding code in recv_msg()
becomes redundant.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
TIPC has so far only supported blocking connect(), meaning that a call
to connect() doesn't return until either the connection is fully
established, or an error occurs. This has proved insufficient for many
users, so we now introduce non-blocking connect(), analogous to how
this is done in TCP and other protocols.
With this feature, if a connection cannot be established instantly,
connect() will return the error code "-EINPROGRESS".
If the user later calls connect() again, he will either have the
return code "-EALREADY" or "-EISCONN", depending on whether the
connection has been established or not.
The user must have explicitly set the socket to be non-blocking
(SOCK_NONBLOCK or O_NONBLOCK, depending on method used), so unless
for some reason they had set this already (the socket would anyway
remain blocking in current TIPC) this change should be completely
backwards compatible.
It is also now possible to call select() or poll() to wait for the
completion of a connection.
An effect of the above is that the actual completion of a connection
may now be performed asynchronously, independent of the calls from
user space. Therefore, we now execute this code in BH context, in
the function filter_rcv(), which is executed upon reception of
messages in the socket.
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
[PG: minor refactoring for improved connect/disconnect function names]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
