__rds_conn_create() did not release conn->c_path when loop_trans != 0 and
trans->t_prefer_loopback != 0 and is_outgoing == 0.
Fixes: aced3ce57c ("RDS tcp loopback connection can hang")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Reviewed-by: Sharath Srinivasan <sharath.srinivasan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When TCP is used as transport and a program on the
system connects to RDS port 16385, connection is
accepted but denied per the rules of RDS. However,
RDS connections object is left in the list. Next
loopback connection will select that connection
object as it is at the head of list. The connection
attempt will hang as the connection object is set
to connect over TCP which is not allowed
The issue can be reproduced easily, use rds-ping
to ping a local IP address. After that use any
program like ncat to connect to the same IP
address and port 16385. This will hang so ctrl-c out.
Now try rds-ping, it will hang.
To fix the issue this patch adds checks to disallow
the connection object creation and destroys the
connection object.
Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In testing with mprds enabled, Oracle Cluster nodes after reboot were
not able to communicate with others nodes and so failed to rejoin
the cluster. Peers with lower IP address initiated connection but the
node could not respond as it choose a different path and could not
initiate a connection as it had a higher IP address.
With this patch, when a node sends out a packet and the selected path
is down, all other paths are also checked and any down paths are
re-connected.
Reviewed-by: Ka-cheong Poon <ka-cheong.poon@oracle.com>
Reviewed-by: David Edmondson <david.edmondson@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Signed-off-by: Rao Shoaib <rao.shoaib@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The proper "tos" value needs to be returned
to user-space (sockopt RDS_INFO_CONNECTIONS).
Fixes: 3eb450367d ("rds: add type of service(tos) infrastructure")
Signed-off-by: Gerd Rausch <gerd.rausch@oracle.com>
Reviewed-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
RDS Service type (TOS) is user-defined and needs to be configured
via RDS IOCTL interface. It must be set before initiating any
traffic and once set the TOS can not be changed. All out-going
traffic from the socket will be associated with its TOS.
Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
[yanjun.zhu@oracle.com: Adapted original patch with ipv6 changes]
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
Mark RDSv3.1 as compat version and add v4.1 version macro's.
Subsequent patches enable TOS(Type of Service) feature which is
tied with v4.1 for RDMA transport.
Reviewed-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
[yanjun.zhu@oracle.com: Adapted original patch with ipv6 changes]
Signed-off-by: Zhu Yanjun <yanjun.zhu@oracle.com>
This patch removes the IPv6 dependency from RDS.
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are many data structures (RDS socket options) used by RDS apps
which use a 32 bit integer to store IP address. To support IPv6,
struct in6_addr needs to be used. To ensure backward compatibility, a
new data structure is introduced for each of those data structures
which use a 32 bit integer to represent an IP address. And new socket
options are introduced to use those new structures. This means that
existing apps should work without a problem with the new RDS module.
For apps which want to use IPv6, those new data structures and socket
options can be used. IPv4 mapped address is used to represent IPv4
address in the new data structures.
v4: Revert changes to SO_RDS_TRANSPORT
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch enables RDS to use IPv6 addresses. For RDS/TCP, the
listener is now an IPv6 endpoint which accepts both IPv4 and IPv6
connection requests. RDS/RDMA/IB uses a private data (struct
rds_ib_connect_private) exchange between endpoints at RDS connection
establishment time to support RDMA. This private data exchange uses a
32 bit integer to represent an IP address. This needs to be changed in
order to support IPv6. A new private data struct
rds6_ib_connect_private is introduced to handle this. To ensure
backward compatibility, an IPv6 capable RDS stack uses another RDMA
listener port (RDS_CM_PORT) to accept IPv6 connection. And it
continues to use the original RDS_PORT for IPv4 RDS connections. When
it needs to communicate with an IPv6 peer, it uses the RDS_CM_PORT to
send the connection set up request.
v5: Fixed syntax problem (David Miller).
v4: Changed port history comments in rds.h (Sowmini Varadhan).
v3: Added support to set up IPv4 connection using mapped address
(David Miller).
Added support to set up connection between link local and non-link
addresses.
Various review comments from Santosh Shilimkar and Sowmini Varadhan.
v2: Fixed bound and peer address scope mismatched issue.
Added back rds_connect() IPv6 changes.
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch changes the internal representation of an IP address to use
struct in6_addr. IPv4 address is stored as an IPv4 mapped address.
All the functions which take an IP address as argument are also
changed to use struct in6_addr. But RDS socket layer is not modified
such that it still does not accept IPv6 address from an application.
And RDS layer does not accept nor initiate IPv6 connections.
v2: Fixed sparse warnings.
Signed-off-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The RDS core module creates rds_connections based on callbacks
from rds_loop_transport when sending/receiving packets to local
addresses.
These connections will need to be cleaned up when they are
created from a netns that is not init_net, and that netns is deleted.
Add the changes aligned with the changes from
commit ebeeb1ad9b ("rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management") for
rds_loop_transport
Reported-and-tested-by: syzbot+4c20b3866171ce8441d2@syzkaller.appspotmail.com
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid VLA[1] by using an already allocated buffer passed
by the caller.
[1] https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Avoid VLA[1] by using an already allocated buffer passed
by the caller.
[1] https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Salvatore Mesoraca <s.mesoraca16@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit ebeeb1ad9b ("rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management")
adds an rcu read critical section to __rd_conn_create. The
memory allocations in that critcal section need to use
GFP_ATOMIC to avoid sleeping.
This patch was verified with syzkaller reproducer.
Reported-by: syzbot+a0564419941aaae3fe3c@syzkaller.appspotmail.com
Fixes: ebeeb1ad9b ("rds: tcp: use rds_destroy_pending() to synchronize
netns/module teardown and rds connection/workq management")
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
An rds_connection can get added during netns deletion between lines 528
and 529 of
506 static void rds_tcp_kill_sock(struct net *net)
:
/* code to pull out all the rds_connections that should be destroyed */
:
528 spin_unlock_irq(&rds_tcp_conn_lock);
529 list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node)
530 rds_conn_destroy(tc->t_cpath->cp_conn);
Such an rds_connection would miss out the rds_conn_destroy()
loop (that cancels all pending work) and (if it was scheduled
after netns deletion) could trigger the use-after-free.
A similar race-window exists for the module unload path
in rds_tcp_exit -> rds_tcp_destroy_conns
Concurrency with netns deletion (rds_tcp_kill_sock()) must be handled
by checking check_net() before enqueuing new work or adding new
connections.
Concurrency with module-unload is handled by maintaining a module
specific flag that is set at the start of the module exit function,
and must be checked before enqueuing new work or adding new connections.
This commit refactors existing RDS_DESTROY_PENDING checks added by
commit 3db6e0d172 ("rds: use RCU to synchronize work-enqueue with
connection teardown") and consolidates all the concurrency checks
listed above into the function rds_destroy_pending().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rds_sendmsg() can enqueue work on cp_send_w from process context, but
it should not enqueue this work if connection teardown has commenced
(else we risk enquing work after rds_conn_path_destroy() has assumed that
all work has been cancelled/flushed).
Similarly some other functions like rds_cong_queue_updates
and rds_tcp_data_ready are called in softirq context, and may end
up enqueuing work on rds_wq after rds_conn_path_destroy() has assumed
that all workqs are quiesced.
Check the RDS_DESTROY_PENDING bit and use rcu synchronization to avoid
all these races.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace c_destroy_in_prog by using a bit in cp_flags that
can set/tested atomically.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
t_name cannot be NULL since it is an array field of a struct.
Replacing null check on static array with string length check using
strnlen()
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 8edc3affc0 ("rds: tcp: Take explicit refcounts on struct net")
introduces a regression in rds-tcp netns cleanup. The cleanup_net(),
(and thus rds_tcp_dev_event notification) is only called from put_net()
when all netns refcounts go to 0, but this cannot happen if the
rds_connection itself is holding a c_net ref that it expects to
release in rds_tcp_kill_sock.
Instead, the rds_tcp_kill_sock callback should make sure to
tear down state carefully, ensuring that the socket teardown
is only done after all data-structures and workqs that depend
on it are quiesced.
The original motivation for commit 8edc3affc0 ("rds: tcp: Take explicit
refcounts on struct net") was to resolve a race condition reported by
syzkaller where workqs for tx/rx/connect were triggered after the
namespace was deleted. Those worker threads should have been
cancelled/flushed before socket tear-down and indeed,
rds_conn_path_destroy() does try to sequence this by doing
/* cancel cp_send_w */
/* cancel cp_recv_w */
/* flush cp_down_w */
/* free data structures */
Here the "flush cp_down_w" will trigger rds_conn_shutdown and thus
invoke rds_tcp_conn_path_shutdown() to close the tcp socket, so that
we ought to have satisfied the requirement that "socket-close is
done after all other dependent state is quiesced". However,
rds_conn_shutdown has a bug in that it *always* triggers the reconnect
workq (and if connection is successful, we always restart tx/rx
workqs so with the right timing, we risk the race conditions reported
by syzkaller).
Netns deletion is like module teardown- no need to restart a
reconnect in this case. We can use the c_destroy_in_prog bit
to avoid restarting the reconnect.
Fixes: 8edc3affc0 ("rds: tcp: Take explicit refcounts on struct net")
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RDS over IB does not use multipath RDS, so the array
of additional rds_conn_path structures is always superfluous
in this case. Reduce the memory footprint of the rds module
by making this a dynamic allocation predicated on whether
the transport is mp_capable.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Tested-by: Efrain Galaviz <efrain.galaviz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We could end up executing rds_conn_shutdown before the rds_recv_worker
thread, then rds_conn_shutdown -> rds_tcp_conn_shutdown can do a
sock_release and set sock->sk to null, which may interleave in bad
ways with rds_recv_worker, e.g., it could result in:
"BUG: unable to handle kernel NULL pointer dereference at 0000000000000078"
[ffff881769f6fd70] release_sock at ffffffff815f337b
[ffff881769f6fd90] rds_tcp_recv at ffffffffa043c888 [rds_tcp]
[ffff881769f6fdb0] rds_recv_worker at ffffffffa04a4810 [rds]
[ffff881769f6fde0] process_one_work at ffffffff810a14c1
[ffff881769f6fe40] worker_thread at ffffffff810a1940
[ffff881769f6fec0] kthread at ffffffff810a6b1e
Also, do not enqueue any new shutdown workq items when the connection is
shutting down (this may happen for rds-tcp in softirq mode, if a FIN
or CLOSE is received while the modules is in the middle of an unload)
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we are unloading the rds_tcp module, we can set linger to 1
and drop pending packets to accelerate reconnect. The peer will
end up resetting the connection based on new generation numbers
of the new incarnation, so hanging on to unsent TCP packets via
linger is mostly pointless in this case.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Jenny Xu <jenny.x.xu@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 1a0e100fb2 ("RDS: TCP: Force every connection to be
initiated by numerically smaller IP address") we no longer need
the logic associated with cp_outgoing, so clean up usage of this
field.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Tested-by: Imanti Mendez <imanti.mendez@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rds_conn_shutdown() runs in workq context, and marks the rds_connection
as DISCONNECTING before quiescing Tx/Rx paths. However, after all I/O
has quiesced, we may still find the rds_connection state to be
RDS_CONN_ERROR if an intervening FIN was processed in softirq context.
This is not a fatal error: rds_conn_shutdown() should continue the
shutdown, and there is no need to log noisy messages about this event.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is incorrect for the rds_connection to piggyback on the
sock_net() refcount for the netns because this gives rise to
a chicken-and-egg problem during rds_conn_destroy. Instead explicitly
take a ref on the net, and hold the netns down till the connection
tear-down is complete.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes below warnings:
warning: symbol 'rds_send_probe' was not declared. Should it be static?
warning: symbol 'rds_send_ping' was not declared. Should it be static?
warning: symbol 'rds_tcp_accept_one_path' was not declared. Should it be static?
warning: symbol 'rds_walk_conn_path_info' was not declared. Should it be static?
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
When 2 RDS peers initiate an RDS-TCP connection simultaneously,
there is a potential for "duelling syns" on either/both sides.
See commit 241b271952 ("RDS-TCP: Reset tcp callbacks if re-using an
outgoing socket in rds_tcp_accept_one()") for a description of this
condition, and the arbitration logic which ensures that the
numerically large IP address in the TCP connection is bound to the
RDS_TCP_PORT ("canonical ordering").
The rds_connection should not be marked as RDS_CONN_UP until the
arbitration logic has converged for the following reason. The sender
may start transmitting RDS datagrams as soon as RDS_CONN_UP is set,
and since the sender removes all datagrams from the rds_connection's
cp_retrans queue based on TCP acks. If the TCP ack was sent from
a tcp socket that got reset as part of duel aribitration (but
before data was delivered to the receivers RDS socket layer),
the sender may end up prematurely freeing the datagram, and
the datagram is no longer reliably deliverable.
This patch remedies that condition by making sure that, upon
receipt of 3WH completion state change notification of TCP_ESTABLISHED
in rds_tcp_state_change, we mark the rds_connection as RDS_CONN_UP
if, and only if, the IP addresses and ports for the connection are
canonically ordered. In all other cases, rds_tcp_state_change will
force an rds_conn_path_drop(), and rds_queue_reconnect() on
both peers will restart the connection to ensure canonical ordering.
A side-effect of enforcing this condition in rds_tcp_state_change()
is that rds_tcp_accept_one_path() can now be refactored for simplicity.
It is also no longer possible to encounter an RDS_CONN_UP connection in
the arbitration logic in rds_tcp_accept_one().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The RDS transport has to be able to distinguish between
two types of failure events:
(a) when the transport fails (e.g., TCP connection reset)
but the RDS socket/connection layer on both sides stays
the same
(b) when the peer's RDS layer itself resets (e.g., due to module
reload or machine reboot at the peer)
In case (a) both sides must reconnect and continue the RDS messaging
without any message loss or disruption to the message sequence numbers,
and this is achieved by rds_send_path_reset().
In case (b) we should reset all rds_connection state to the
new incarnation of the peer. Examples of state that needs to
be reset are next expected rx sequence number from, or messages to be
retransmitted to, the new incarnation of the peer.
To achieve this, the RDS handshake probe added as part of
commit 5916e2c155 ("RDS: TCP: Enable multipath RDS for TCP")
is enhanced so that sender and receiver of the RDS ping-probe
will add a generation number as part of the RDS_EXTHDR_GEN_NUM
extension header. Each peer stores local and remote generation
numbers as part of each rds_connection. Changes in generation
number will be detected via incoming handshake probe ping
request or response and will allow the receiver to reset rds_connection
state.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This macro's last use was removed in commit d769ef81d5
("RDS: Update rds_conn_shutdown to work with rds_conn_path")
so make the macro and the __rds_conn_error function definition
and declaration disappear.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use RDS probe-ping to compute how many paths may be used with
the peer, and to synchronously start the multiple paths. If mprds is
supported, hash outgoing traffic to one of multiple paths in rds_sendmsg()
when multipath RDS is supported by the transport.
CC: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When reconnecting, the peer with the smaller IP address will initiate
the reconnect, to avoid needless duelling SYN issues.
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The struct rds_tcp_connection is the transport-specific private
data structure that tracks TCP information per rds_conn_path.
Modify this structure to have a back-pointer to the rds_conn_path
for which it is the ->cp_transport_data.
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Refactor code to avoid separate indirections for single-path
and multipath transports. All transports (both single and mp-capable)
will get a pointer to the rds_conn_path, and can trivially derive
the rds_connection from the ->cp_conn.
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Refactor rds_conn_destroy() so that the per-path dismantling
is done in rds_conn_path_destroy, and then iterate as needed
over rds_conn_path_destroy().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit changes rds_conn_shutdown to take a rds_conn_path *
argument, allowing it to shutdown paths other than c_path[0] for
MP-capable transports.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a for() loop in __rds_conn_create to initialize all the
conn_paths, in preparate for MP capable transports.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rds_conn_path_error() is the MP-aware analog of rds_conn_error,
to be used by multipath-capable callers.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit updates the callbacks related to the rds-info command
so that they walk through all the rds_conn_path structures and
report the requested info.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rds_conn_path_connect_if_down() works on the rds_conn_path
that it is passed. Callers who are not t_m_capable may continue
calling rds_conn_connect_if_down, which will invoke
rds_conn_path_connect_if_down() with the default c_path[0].
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation for multipath RDS, split the rds_connection
structure into a base structure, and a per-path struct rds_conn_path.
The base structure tracks information and locks common to all
paths. The workqs for send/recv/shutdown etc are tracked per
rds_conn_path. Thus the workq callbacks now work with rds_conn_path.
This commit allows for one rds_conn_path per rds_connection, and will
be extended into multiple conn_paths in subsequent commits.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sasha's found a NULL pointer dereference in the RDS connection code when
sending a message to an apparently unbound socket. The problem is caused
by the code checking if the socket is bound in rds_sendmsg(), which checks
the rs_bound_addr field without taking a lock on the socket. This opens a
race where rs_bound_addr is temporarily set but where the transport is not
in rds_bind(), leading to a NULL pointer dereference when trying to
dereference 'trans' in __rds_conn_create().
Vegard wrote a reproducer for this issue, so kindly ask him to share if
you're interested.
I cannot reproduce the NULL pointer dereference using Vegard's reproducer
with this patch, whereas I could without.
Complete earlier incomplete fix to CVE-2015-6937:
74e98eb085 ("RDS: verify the underlying transport exists before creating a connection")
Cc: David S. Miller <davem@davemloft.net>
Cc: stable@vger.kernel.org
Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com>
Reviewed-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit f711a6ae06 ("net/rds: RDS-TCP: Always create a new rds_sock
for an incoming connection.") modified rds-tcp so that an incoming SYN
would ignore an existing "client" TCP connection which had the local
port set to the transient port. The motivation for ignoring the existing
"client" connection in f711a6ae was to avoid race conditions and an
endless duel of reconnect attempts triggered by a restart/abort of one
of the nodes in the TCP connection.
However, having separate sockets for active and passive sides
is avoidable, and the simpler model of a single TCP socket for
both send and receives of all RDS connections associated with
that tcp socket makes for easier observability. We avoid the race
conditions from f711a6ae by attempting reconnects in rds_conn_shutdown
if, and only if, the (new) c_outgoing bit is set for RDS_TRANS_TCP.
The c_outgoing bit is initialized in __rds_conn_create().
A side-effect of re-using the client rds_connection for an incoming
SYN is the potential of encountering duelling SYNs, i.e., we
have an outgoing RDS_CONN_CONNECTING socket when we get the incoming
SYN. The logic to arbitrate this criss-crossing SYN exchange in
rds_tcp_accept_one() has been modified to emulate the BGP state
machine: the smaller IP address should back off from the connection attempt.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only return a conn if the rds_conn_net(conn) matches the struct
net passed to rds_conn_lookup().
Fixes: 467fa15356 ("RDS-TCP: Support multiple RDS-TCP listen endpoints,
one per netns.")
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If we get an ENOMEM during rds_ib_recv_refill, we might never come
back and refill again later. Patch makes sure to kick krdsd into
helping out.
To achieve this we add RDS_RECV_REFILL flag and update in the refill
path based on that so that at least some therad will keep posting
receive buffers.
Since krdsd and softirq both might race for refill, we decide to
schedule on work queue based on ring_low instead of ring_empty.
Reviewed-by: Ajaykumar Hotchandani <ajaykumar.hotchandani@oracle.com>
Signed-off-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Open the sockets calling sock_create_kern() with the correct struct net
pointer, and use that struct net pointer when verifying the
address passed to rds_bind().
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When the peer of an RDS-TCP connection restarts, a reconnect
attempt should only be made from the active side of the TCP
connection, i.e. the side that has a transient TCP port
number. Do not add the passive side of the TCP connection
to the c_hash_node and thus avoid triggering rds_queue_reconnect()
for passive rds connections.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When running RDS over TCP, the active (client) side connects to the
listening ("passive") side at the RDS_TCP_PORT. After the connection
is established, if the client side reboots (potentially without even
sending a FIN) the server still has a TCP socket in the esablished
state. If the server-side now gets a new SYN comes from the client
with a different client port, TCP will create a new socket-pair, but
the RDS layer will incorrectly pull up the old rds_connection (which
is still associated with the stale t_sock and RDS socket state).
This patch corrects this behavior by having rds_tcp_accept_one()
always create a new connection for an incoming TCP SYN.
The rds and tcp state associated with the old socket-pair is cleaned
up via the rds_tcp_state_change() callback which would typically be
invoked in most cases when the client-TCP sends a FIN on TCP restart,
triggering a transition to CLOSE_WAIT state. In the rarer event of client
death without a FIN, TCP_KEEPALIVE probes on the socket will detect
the stale socket, and the TCP transition to CLOSE state will trigger
the RDS state cleanup.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a determined set of concurrent senders keep the send queue full,
we can loop forever inside rds_send_xmit. This fix has two parts.
First we are dropping out of the while(1) loop after we've processed a
large batch of messages.
Second we add a generation number that gets bumped each time the
xmit bit lock is acquired. If someone else has jumped in and
made progress in the queue, we skip our goto restart.
Original patch by Chris Mason.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Passive connections were added for the case where one loopback IB
connection between identical addresses needs another connection to store
the second QP. Unfortunately, they were also created in the case where
the addesses differ and we already have both QPs.
This lead to a message reordering bug.
- two different IB interfaces and addresses on a machine: A B
- traffic is sent from A to B
- connection from A-B is created, connect request sent
- listening accepts connect request, B-A is created
- traffic flows, next_rx is incremented
- unacked messages exist on the retrans list
- connection A-B is shut down, new connect request sent
- listen sees existing loopback B-A, creates new passive B-A
- retrans messages are sent and delivered because of 0 next_rx
The problem is that the second connection request saw the previously
existing parent connection. Instead of using it, and using the existing
next_rx_seq state for the traffic between those IPs, it mistakenly
thought that it had to create a passive connection.
We fix this by only using passive connections in the special case where
laddr and faddr match. In this case we'll only ever have one parent
sending connection requests and one passive connection created as the
listening path sees the existing parent connection which initiated the
request.
Original patch by Zach Brown
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
