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2018-10-29sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peerXin Long
If a transport is removed by asconf but there still are some chunks with this transport queuing on out_chunk_list, later an use-after-free issue will be caused when accessing this transport from these chunks in sctp_outq_flush(). This is an old bug, we fix it by clearing the transport of these chunks in out_chunk_list when removing a transport in sctp_assoc_rm_peer(). Reported-by: syzbot+56a40ceee5fb35932f4d@syzkaller.appspotmail.com Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-15sctp: use the pmtu from the icmp packet to update transport pathmtuXin Long
Other than asoc pmtu sync from all transports, sctp_assoc_sync_pmtu is also processing transport pmtu_pending by icmp packets. But it's meaningless to use sctp_dst_mtu(t->dst) as new pmtu for a transport. The right pmtu value should come from the icmp packet, and it would be saved into transport->mtu_info in this patch and used later when the pmtu sync happens in sctp_sendmsg_to_asoc or sctp_packet_config. Besides, without this patch, as pmtu can only be updated correctly when receiving a icmp packet and no place is holding sock lock, it will take long time if the sock is busy with sending packets. Note that it doesn't process transport->mtu_info in .release_cb(), as there is no enough information for pmtu update, like for which asoc or transport. It is not worth traversing all asocs to check pmtu_pending. So unlike tcp, sctp does this in tx path, for which mtu_info needs to be atomic_t. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-04sctp: add support for setting flowlabel when adding a transportXin Long
Struct sockaddr_in6 has the member sin6_flowinfo that includes the ipv6 flowlabel, it should also support for setting flowlabel when adding a transport whose ipaddr is from userspace. Note that addrinfo in sctp_sendmsg is using struct in6_addr for the secondary addrs, which doesn't contain sin6_flowinfo, and it needs to copy sin6_flowinfo from the primary addr. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-04sctp: add support for dscp and flowlabel per transportXin Long
Like some other per transport params, flowlabel and dscp are added in transport, asoc and sctp_sock. By default, transport sets its value from asoc's, and asoc does it from sctp_sock. flowlabel only works for ipv6 transport. Other than that they need to be passed down in sctp_xmit, flow4/6 also needs to set them before looking up route in get_dst. Note that it uses '& 0x100000' to check if flowlabel is set and '& 0x1' (tos 1st bit is unused) to check if dscp is set by users, so that they could be set to 0 by sockopt in next patch. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller
The bpf syscall and selftests conflicts were trivial overlapping changes. The r8169 change involved moving the added mdelay from 'net' into a different function. A TLS close bug fix overlapped with the splitting of the TLS state into separate TX and RX parts. I just expanded the tests in the bug fix from "ctx->conf == X" into "ctx->tx_conf == X && ctx->rx_conf == X". Signed-off-by: David S. Miller <davem@davemloft.net>
2018-05-07sctp: delay the authentication for the duplicated cookie-echo chunkXin Long
Now sctp only delays the authentication for the normal cookie-echo chunk by setting chunk->auth_chunk in sctp_endpoint_bh_rcv(). But for the duplicated one with auth, in sctp_assoc_bh_rcv(), it does authentication first based on the old asoc, which will definitely fail due to the different auth info in the old asoc. The duplicated cookie-echo chunk will create a new asoc with the auth info from this chunk, and the authentication should also be done with the new asoc's auth info for all of the collision 'A', 'B' and 'D'. Otherwise, the duplicated cookie-echo chunk with auth will never pass the authentication and create the new connection. This issue exists since very beginning, and this fix is to make sctp_assoc_bh_rcv() follow the way sctp_endpoint_bh_rcv() does for the normal cookie-echo chunk to delay the authentication. While at it, remove the unused params from sctp_sf_authenticate() and define sctp_auth_chunk_verify() used for all the places that do the delayed authentication. v1->v2: fix the typo in changelog as Marcelo noticed. Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27sctp: introduce sctp_dst_mtuMarcelo Ricardo Leitner
Which makes sure that the MTU respects the minimum value of SCTP_DEFAULT_MINSEGMENT and that it is correctly aligned. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27sctp: introduce sctp_assoc_update_frag_pointMarcelo Ricardo Leitner
and avoid the open-coded versions of it. Now sctp_datamsg_from_user can just re-use asoc->frag_point as it will always be updated. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27sctp: introduce sctp_assoc_set_pmtuMarcelo Ricardo Leitner
All changes to asoc PMTU should now go through this wrapper, making it easier to track them and to do other actions upon it. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27sctp: remove an if() that is always trueMarcelo Ricardo Leitner
As noticed by Xin Long, the if() here is always true as PMTU can never be 0. Reported-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-27sctp: move transport pathmtu calc away of sctp_assoc_add_peerMarcelo Ricardo Leitner
There was only one case that sctp_assoc_add_peer couldn't handle, which is when SPP_PMTUD_DISABLE is set and pathmtu not initialized. So add this situation to sctp_transport_route and reuse what was already in there. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-04-25sctp: remove the unused sctp_assoc_is_match functionXin Long
After Commit 4f0087812648 ("sctp: apply rhashtable api to send/recv path"), there's no place using sctp_assoc_is_match, so remove it. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-12-11sctp: implement enqueue_event for sctp_stream_interleaveXin Long
enqueue_event is added as a member of sctp_stream_interleave, used to enqueue either data, idata or notification events into user socket rx queue. It replaces sctp_ulpq_tail_event used in the other places with enqueue_event. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-25net: sctp: Convert timers to use timer_setup()Kees Cook
In preparation for unconditionally passing the struct timer_list pointer to all timer callbacks, switch to using the new timer_setup() and from_timer() to pass the timer pointer explicitly. Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: linux-sctp@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06sctp: remove the typedef sctp_subtype_tXin Long
This patch is to remove the typedef sctp_subtype_t, and replace with union sctp_subtype in the places where it's using this typedef. Note that it doesn't fix many indents although it should, as sctp_disposition_t's removal would mess them up again. So better to fix them when removing sctp_disposition_t in later patch. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06sctp: remove the typedef sctp_transport_cmd_tXin Long
This patch is to remove the typedef sctp_transport_cmd_t, and replace with enum sctp_transport_cmd in the places where it's using this typedef. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-06sctp: remove the typedef sctp_scope_tXin Long
This patch is to remove the typedef sctp_scope_t, and replace with enum sctp_scope in the places where it's using this typedef. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-04net, sctp: convert sctp_ep_common.refcnt from atomic_t to refcount_tReshetova, Elena
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01sctp: remove the typedef sctp_paramhdr_tXin Long
This patch is to remove the typedef sctp_paramhdr_t, and replace with struct sctp_paramhdr in the places where it's using this typedef. It is also to fix some indents and use sizeof(variable) instead of sizeof(type). Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-20sctp: handle errors when updating asocXin Long
It's a bad thing not to handle errors when updating asoc. The memory allocation failure in any of the functions called in sctp_assoc_update() would cause sctp to work unexpectedly. This patch is to fix it by aborting the asoc and reporting the error when any of these functions fails. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-10sctp: no need to check assoc id before calling sctp_assoc_set_idXin Long
sctp_assoc_set_id does the assoc id check in the beginning when processing dupcookie, no need to do the same check before calling it. v1->v2: fix some typo errs Marcelo pointed in changelog. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-02sctp: merge sctp_stream_new and sctp_stream_initXin Long
Since last patch, sctp doesn't need to alloc memory for asoc->stream any more. sctp_stream_new and sctp_stream_init both are used to alloc memory for stream.in or stream.out, and their names are also confusing. This patch is to merge them into sctp_stream_init, and only pass stream and streamcnt parameters into it, instead of the whole asoc. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-02sctp: define the member stream as an object instead of pointer in asocXin Long
As Marcelo's suggestion, stream is a fixed size member of asoc and would not grow with more streams. To avoid an allocation for it, this patch is to define it as an object instead of pointer and update the places using it, also create sctp_stream_update() called in sctp_assoc_update() to migrate the stream info from one stream to another. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-24sctp: fix stream update when processing dupcookieXin Long
Since commit 3dbcc105d556 ("sctp: alloc stream info when initializing asoc"), stream and stream.out info are always alloced when creating an asoc. So it's not correct to check !asoc->stream before updating stream info when processing dupcookie, but would be better to check asoc state instead. Fixes: 3dbcc105d556 ("sctp: alloc stream info when initializing asoc") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-05sctp: get sock from transport in sctp_transport_update_pmtuXin Long
This patch is almost to revert commit 02f3d4ce9e81 ("sctp: Adjust PMTU updates to accomodate route invalidation."). As t->asoc can't be NULL in sctp_transport_update_pmtu, it could get sk from asoc, and no need to pass sk into that function. It is also to remove some duplicated codes from that function. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-30sctp: alloc stream info when initializing asocXin Long
When sending a msg without asoc established, sctp will send INIT packet first and then enqueue chunks. Before receiving INIT_ACK, stream info is not yet alloced. But enqueuing chunks needs to access stream info, like out stream state and out stream cnt. This patch is to fix it by allocing out stream info when initializing an asoc, allocing in stream and re-allocing out stream when processing init. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-22sctp: remove useless err from sctp_association_initXin Long
This patch is to remove the unnecessary temporary variable 'err' from sctp_association_init. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-07sctp: add dst_pending_confirm flagJulian Anastasov
Add new transport flag to allow sockets to confirm neighbour. When same struct dst_entry can be used for many different neighbours we can not use it for pending confirmations. The flag is propagated from transport to every packet. It is reset when cached dst is reset. Reported-by: YueHaibing <yuehaibing@huawei.com> Fixes: 5110effee8fd ("net: Do delayed neigh confirmation.") Fixes: f2bb4bedf35d ("ipv4: Cache output routes in fib_info nexthops.") Signed-off-by: Julian Anastasov <ja@ssi.bg> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18sctp: add sockopt SCTP_ENABLE_STREAM_RESETXin Long
This patch is to add sockopt SCTP_ENABLE_STREAM_RESET to get/set strreset_enable to indicate which reconf request type it supports, which is described in rfc6525 section 6.3.1. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18sctp: add reconf_enable in asoc ep and netnsXin Long
This patch is to add reconf_enable field in all of asoc ep and netns to indicate if they support stream reset. When initializing, asoc reconf_enable get the default value from ep reconf_enable which is from netns netns reconf_enable by default. It is also to add reconf_capable in asoc peer part to know if peer supports reconf_enable, the value is set if ext params have reconf chunk support when processing init chunk, just as rfc6525 section 5.1.1 demands. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18sctp: add stream reconf timerXin Long
This patch is to add a per transport timer based on sctp timer frame for stream reconf chunk retransmission. It would start after sending a reconf request chunk, and stop after receiving the response chunk. If the timer expires, besides retransmitting the reconf request chunk, it would also do the same thing with data RTO timer. like to increase the appropriate error counts, and perform threshold management, possibly destroying the asoc if sctp retransmission thresholds are exceeded, just as section 5.1.1 describes. This patch is also to add asoc strreset_chunk, it is used to save the reconf request chunk, so that it can be retransmitted, and to check if the response is really for this request by comparing the information inside with the response chunk as well. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-18sctp: add support for generating stream reconf ssn reset request chunkXin Long
This patch is to add asoc strreset_outseq and strreset_inseq for saving the reconf request sequence, initialize them when create assoc and process init, and also to define Incoming and Outgoing SSN Reset Request Parameter described in rfc6525 section 4.1 and 4.2, As they can be in one same chunk as section rfc6525 3.1-3 describes, it makes them in one function. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-01-06sctp: prepare asoc stream for stream reconfXin Long
sctp stream reconf, described in RFC 6525, needs a structure to save per stream information in assoc, like stream state. In the future, sctp stream scheduler also needs it to save some stream scheduler params and queues. This patchset is to prepare the stream array in assoc for stream reconf. It defines sctp_stream that includes stream arrays inside to replace ssnmap. Note that we use different structures for IN and OUT streams, as the members in per OUT stream will get more and more different from per IN stream. v1->v2: - put these patches into a smaller group. v2->v3: - define sctp_stream to contain stream arrays, and create stream.c to put stream-related functions. - merge 3 patches into 1, as new sctp_stream has the same name with before. Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-23sctp: fix recovering from 0 win with small data chunksMarcelo Ricardo Leitner
Currently if SCTP closes the receive window with window pressure, mostly caused by excessive skb overhead on payload/overheads ratio, SCTP will close the window abruptly while saving the delta on rwnd_press. It will start recovering rwnd as the chunks are consumed by the application and the rwnd_press will be only recovered after rwnd reach the same value as of rwnd_press, mostly to prevent silly window syndrome. Thing is, this is very inefficient with small data chunks, as with those it will never reach back that value, and thus it will never recover from such pressure. This means that we will not issue window updates when recovering from 0 window and will rely on a sender retransmit to notice it. The fix here is to remove such threshold, as no value is good enough: it depends on the (avg) chunk sizes being used. Test with netperf -t SCTP_STREAM -- -m 1, and trigger 0 window by sending SIGSTOP to netserver, sleep 1.2, and SIGCONT. Rate limited to 845kbps, for visibility. Capture done at netserver side. Previously: 01.500751 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632372996] [a_rwnd 99153] [ 01.500752 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632372997] [SID: 0] [SS 01.517471 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373010] [SID: 0] [SS 01.517483 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap 01.517485 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373083] [SID: 0] [SS 01.517488 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap 01.534168 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373096] [SID: 0] [SS 01.534180 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap 01.534181 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373169] [SID: 0] [SS 01.534185 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap 02.525978 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373010] [SID: 0] [SS 02.526021 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373009] [a_rwnd 0] [#gap (window update missed) 04.573807 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373010] [SID: 0] [SS 04.779370 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373082] [a_rwnd 859] [#g 04.789162 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373083] [SID: 0] [SS 04.789323 IP A.36925 > B.48277: sctp (1) [DATA] (B)(E) [TSN: 632373156] [SID: 0] [SS 04.789372 IP B.48277 > A.36925: sctp (1) [SACK] [cum ack 632373228] [a_rwnd 786] [#g After: 02.568957 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098728] [a_rwnd 99153] 02.568961 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098729] [SID: 0] [S 02.585631 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098742] [SID: 0] [S 02.585666 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga 02.585671 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098815] [SID: 0] [S 02.585683 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga 02.602330 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098828] [SID: 0] [S 02.602359 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga 02.602363 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098901] [SID: 0] [S 02.602372 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga 03.600788 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098742] [SID: 0] [S 03.600830 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 0] [#ga 03.619455 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 13508] 03.619479 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 27017] 03.619497 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 40526] 03.619516 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 54035] 03.619533 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 67544] 03.619552 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 81053] 03.619570 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098741] [a_rwnd 94562] (following data transmission triggered by window updates above) 03.633504 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098742] [SID: 0] [S 03.836445 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098814] [a_rwnd 100000] 03.843125 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098815] [SID: 0] [S 03.843285 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098888] [SID: 0] [S 03.843345 IP B.50536 > A.55173: sctp (1) [SACK] [cum ack 2490098960] [a_rwnd 99894] 03.856546 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490098961] [SID: 0] [S 03.866450 IP A.55173 > B.50536: sctp (1) [DATA] (B)(E) [TSN: 2490099011] [SID: 0] [S Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-12-23sctp: do not loose window information if in rwnd_overMarcelo Ricardo Leitner
It's possible that we receive a packet that is larger than current window. If it's the first packet in this way, it will cause it to increase rwnd_over. Then, if we receive another data chunk (specially as SCTP allows you to have one data chunk in flight even during 0 window), rwnd_over will be overwritten instead of added to. In the long run, this could cause the window to grow bigger than its initial size, as rwnd_over would be charged only for the last received data chunk while the code will try open the window for all packets that were received and had its value in rwnd_over overwritten. This, then, can lead to the worsening of payload/buffer ratio and cause rwnd_press to kick in more often. The fix is to sum it too, same as is done for rwnd_press, so that if we receive 3 chunks after closing the window, we still have to release that same amount before re-opening it. Log snippet from sctp_test exhibiting the issue: [ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000 rwnd decreased by 1 to (0, 1, 114221) [ 146.209232] sctp: sctp_assoc_rwnd_decrease: association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1! [ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000 rwnd decreased by 1 to (0, 1, 114221) [ 146.209232] sctp: sctp_assoc_rwnd_decrease: association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1! [ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000 rwnd decreased by 1 to (0, 1, 114221) [ 146.209232] sctp: sctp_assoc_rwnd_decrease: association:ffff88013928e000 has asoc->rwnd:0, asoc->rwnd_over:1! [ 146.209232] sctp: sctp_assoc_rwnd_decrease: asoc:ffff88013928e000 rwnd decreased by 1 to (0, 1, 114221) Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-16sctp: use new rhlist interface on sctp transport rhashtableXin Long
Now sctp transport rhashtable uses hash(lport, dport, daddr) as the key to hash a node to one chain. If in one host thousands of assocs connect to one server with the same lport and different laddrs (although it's not a normal case), all the transports would be hashed into the same chain. It may cause to keep returning -EBUSY when inserting a new node, as the chain is too long and sctp inserts a transport node in a loop, which could even lead to system hangs there. The new rhlist interface works for this case that there are many nodes with the same key in one chain. It puts them into a list then makes this list be as a node of the chain. This patch is to replace rhashtable_ interface with rhltable_ interface. Since a chain would not be too long and it would not return -EBUSY with this fix when inserting a node, the reinsert loop is also removed here. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-22sctp: rename WORD_TRUNC/ROUND macrosMarcelo Ricardo Leitner
To something more meaningful these days, specially because this is working on packet headers or lengths and which are not tied to any CPU arch but to the protocol itself. So, WORD_TRUNC becomes SCTP_TRUNC4 and WORD_ROUND becomes SCTP_PAD4. Reported-by: David Laight <David.Laight@ACULAB.COM> Reported-by: David Miller <davem@davemloft.net> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-11sctp: add SCTP_PR_SUPPORTED on sctp sockoptXin Long
According to section 4.5 of rfc7496, prsctp_enable should be per asoc. We will add prsctp_enable to both asoc and ep, and replace the places where it used net.sctp->prsctp_enable with asoc->prsctp_enable. ep->prsctp_enable will be initialized with net.sctp->prsctp_enable, and asoc->prsctp_enable will be initialized with ep->prsctp_enable. We can also modify it's value through sockopt SCTP_PR_SUPPORTED. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-20sctp: align MTU to a wordMarcelo Ricardo Leitner
SCTP is a protocol that is aligned to a word (4 bytes). Thus using bare MTU can sometimes return values that are not aligned, like for loopback, which is 65536 but ipv4_mtu() limits that to 65535. This mis-alignment will cause the last non-aligned bytes to never be used and can cause issues with congestion control. So it's better to just consider a lower MTU and keep congestion control calcs saner as they are based on PMTU. Same applies to icmp frag needed messages, which is also fixed by this patch. One other effect of this is the inability to send MTU-sized packet without queueing or fragmentation and without hitting Nagle. As the check performed at sctp_packet_can_append_data(): if (chunk->skb->len + q->out_qlen >= transport->pathmtu - packet->overhead) /* Enough data queued to fill a packet */ return SCTP_XMIT_OK; with the above example of MTU, if there are no other messages queued, one cannot send a packet that just fits one packet (65532 bytes) and without causing DATA chunk fragmentation or a delay. v2: - Added WORD_TRUNC macro Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-13sctp: allow sctp_transmit_packet and others to use gfpMarcelo Ricardo Leitner
Currently sctp_sendmsg() triggers some calls that will allocate memory with GFP_ATOMIC even when not necessary. In the case of sctp_packet_transmit it will allocate a linear skb that will be used to construct the packet and this may cause sends to fail due to ENOMEM more often than anticipated specially with big MTUs. This patch thus allows it to inherit gfp flags from upper calls so that it can use GFP_KERNEL if it was triggered by a sctp_sendmsg call or similar. All others, like retransmits or flushes started from BH, are still allocated using GFP_ATOMIC. In netperf tests this didn't result in any performance drawbacks when memory is not too fragmented and made it trigger ENOMEM way less often. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-13sctp: fix the transports round robin issue when init is retransmittedXin Long
prior to this patch, at the beginning if we have two paths in one assoc, they may have the same params other than the last_time_heard, it will try the paths like this: 1st cycle try trans1 fail. then trans2 is selected.(cause it's last_time_heard is after trans1). 2nd cycle: try trans2 fail then trans2 is selected.(cause it's last_time_heard is after trans1). 3rd cycle: try trans2 fail then trans2 is selected.(cause it's last_time_heard is after trans1). .... trans1 will never have change to be selected, which is not what we expect. we should keeping round robin all the paths if they are just added at the beginning. So at first every tranport's last_time_heard should be initialized 0, so that we ensure they have the same value at the beginning, only by this, all the transports could get equal chance to be selected. Then for sctp_trans_elect_best, it should return the trans_next one when *trans == *trans_next, so that we can try next if it fails, but now it always return trans. so we can fix it by exchanging these two params when we calls sctp_trans_elect_tie(). Fixes: 4c47af4d5eb2 ('net: sctp: rework multihoming retransmission path selection to rfc4960') Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-05sctp: apply rhashtable api to send/recv pathXin Long
apply lookup apis to two functions, for __sctp_endpoint_lookup_assoc and __sctp_lookup_association, it's invoked in the protection of sock lock, it will be safe, but sctp_lookup_association need to call rcu_read_lock() and to detect the t->dead to protect it. Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-06mm, page_alloc: distinguish between being unable to sleep, unwilling to ↵Mel Gorman
sleep and avoiding waking kswapd __GFP_WAIT has been used to identify atomic context in callers that hold spinlocks or are in interrupts. They are expected to be high priority and have access one of two watermarks lower than "min" which can be referred to as the "atomic reserve". __GFP_HIGH users get access to the first lower watermark and can be called the "high priority reserve". Over time, callers had a requirement to not block when fallback options were available. Some have abused __GFP_WAIT leading to a situation where an optimisitic allocation with a fallback option can access atomic reserves. This patch uses __GFP_ATOMIC to identify callers that are truely atomic, cannot sleep and have no alternative. High priority users continue to use __GFP_HIGH. __GFP_DIRECT_RECLAIM identifies callers that can sleep and are willing to enter direct reclaim. __GFP_KSWAPD_RECLAIM to identify callers that want to wake kswapd for background reclaim. __GFP_WAIT is redefined as a caller that is willing to enter direct reclaim and wake kswapd for background reclaim. This patch then converts a number of sites o __GFP_ATOMIC is used by callers that are high priority and have memory pools for those requests. GFP_ATOMIC uses this flag. o Callers that have a limited mempool to guarantee forward progress clear __GFP_DIRECT_RECLAIM but keep __GFP_KSWAPD_RECLAIM. bio allocations fall into this category where kswapd will still be woken but atomic reserves are not used as there is a one-entry mempool to guarantee progress. o Callers that are checking if they are non-blocking should use the helper gfpflags_allow_blocking() where possible. This is because checking for __GFP_WAIT as was done historically now can trigger false positives. Some exceptions like dm-crypt.c exist where the code intent is clearer if __GFP_DIRECT_RECLAIM is used instead of the helper due to flag manipulations. o Callers that built their own GFP flags instead of starting with GFP_KERNEL and friends now also need to specify __GFP_KSWAPD_RECLAIM. The first key hazard to watch out for is callers that removed __GFP_WAIT and was depending on access to atomic reserves for inconspicuous reasons. In some cases it may be appropriate for them to use __GFP_HIGH. The second key hazard is callers that assembled their own combination of GFP flags instead of starting with something like GFP_KERNEL. They may now wish to specify __GFP_KSWAPD_RECLAIM. It's almost certainly harmless if it's missed in most cases as other activity will wake kswapd. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-28net: sctp: Don't use 64 kilobyte lookup table for four elementsDenys Vlasenko
Seemingly innocuous sctp_trans_state_to_prio_map[] array is way bigger than it looks, since "[SCTP_UNKNOWN] = 2" expands into "[0xffff] = 2" ! This patch replaces it with switch() statement. Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com> CC: Vlad Yasevich <vyasevich@gmail.com> CC: Neil Horman <nhorman@tuxdriver.com> CC: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> CC: linux-sctp@vger.kernel.org CC: netdev@vger.kernel.org CC: linux-kernel@vger.kernel.org Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-02net: sctp: Deletion of an unnecessary check before the function call "kfree"Markus Elfring
The kfree() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Acked-By: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2015-01-26net: sctp: fix slab corruption from use after free on INIT collisionsDaniel Borkmann
When hitting an INIT collision case during the 4WHS with AUTH enabled, as already described in detail in commit 1be9a950c646 ("net: sctp: inherit auth_capable on INIT collisions"), it can happen that we occasionally still remotely trigger the following panic on server side which seems to have been uncovered after the fix from commit 1be9a950c646 ... [ 533.876389] BUG: unable to handle kernel paging request at 00000000ffffffff [ 533.913657] IP: [<ffffffff811ac385>] __kmalloc+0x95/0x230 [ 533.940559] PGD 5030f2067 PUD 0 [ 533.957104] Oops: 0000 [#1] SMP [ 533.974283] Modules linked in: sctp mlx4_en [...] [ 534.939704] Call Trace: [ 534.951833] [<ffffffff81294e30>] ? crypto_init_shash_ops+0x60/0xf0 [ 534.984213] [<ffffffff81294e30>] crypto_init_shash_ops+0x60/0xf0 [ 535.015025] [<ffffffff8128c8ed>] __crypto_alloc_tfm+0x6d/0x170 [ 535.045661] [<ffffffff8128d12c>] crypto_alloc_base+0x4c/0xb0 [ 535.074593] [<ffffffff8160bd42>] ? _raw_spin_lock_bh+0x12/0x50 [ 535.105239] [<ffffffffa0418c11>] sctp_inet_listen+0x161/0x1e0 [sctp] [ 535.138606] [<ffffffff814e43bd>] SyS_listen+0x9d/0xb0 [ 535.166848] [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b ... or depending on the the application, for example this one: [ 1370.026490] BUG: unable to handle kernel paging request at 00000000ffffffff [ 1370.026506] IP: [<ffffffff811ab455>] kmem_cache_alloc+0x75/0x1d0 [ 1370.054568] PGD 633c94067 PUD 0 [ 1370.070446] Oops: 0000 [#1] SMP [ 1370.085010] Modules linked in: sctp kvm_amd kvm [...] [ 1370.963431] Call Trace: [ 1370.974632] [<ffffffff8120f7cf>] ? SyS_epoll_ctl+0x53f/0x960 [ 1371.000863] [<ffffffff8120f7cf>] SyS_epoll_ctl+0x53f/0x960 [ 1371.027154] [<ffffffff812100d3>] ? anon_inode_getfile+0xd3/0x170 [ 1371.054679] [<ffffffff811e3d67>] ? __alloc_fd+0xa7/0x130 [ 1371.080183] [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b With slab debugging enabled, we can see that the poison has been overwritten: [ 669.826368] BUG kmalloc-128 (Tainted: G W ): Poison overwritten [ 669.826385] INFO: 0xffff880228b32e50-0xffff880228b32e50. First byte 0x6a instead of 0x6b [ 669.826414] INFO: Allocated in sctp_auth_create_key+0x23/0x50 [sctp] age=3 cpu=0 pid=18494 [ 669.826424] __slab_alloc+0x4bf/0x566 [ 669.826433] __kmalloc+0x280/0x310 [ 669.826453] sctp_auth_create_key+0x23/0x50 [sctp] [ 669.826471] sctp_auth_asoc_create_secret+0xcb/0x1e0 [sctp] [ 669.826488] sctp_auth_asoc_init_active_key+0x68/0xa0 [sctp] [ 669.826505] sctp_do_sm+0x29d/0x17c0 [sctp] [...] [ 669.826629] INFO: Freed in kzfree+0x31/0x40 age=1 cpu=0 pid=18494 [ 669.826635] __slab_free+0x39/0x2a8 [ 669.826643] kfree+0x1d6/0x230 [ 669.826650] kzfree+0x31/0x40 [ 669.826666] sctp_auth_key_put+0x19/0x20 [sctp] [ 669.826681] sctp_assoc_update+0x1ee/0x2d0 [sctp] [ 669.826695] sctp_do_sm+0x674/0x17c0 [sctp] Since this only triggers in some collision-cases with AUTH, the problem at heart is that sctp_auth_key_put() on asoc->asoc_shared_key is called twice when having refcnt 1, once directly in sctp_assoc_update() and yet again from within sctp_auth_asoc_init_active_key() via sctp_assoc_update() on the already kzfree'd memory, which is also consistent with the observation of the poison decrease from 0x6b to 0x6a (note: the overwrite is detected at a later point in time when poison is checked on new allocation). Reference counting of auth keys revisited: Shared keys for AUTH chunks are being stored in endpoints and associations in endpoint_shared_keys list. On endpoint creation, a null key is being added; on association creation, all endpoint shared keys are being cached and thus cloned over to the association. struct sctp_shared_key only holds a pointer to the actual key bytes, that is, struct sctp_auth_bytes which keeps track of users internally through refcounting. Naturally, on assoc or enpoint destruction, sctp_shared_key are being destroyed directly and the reference on sctp_auth_bytes dropped. User space can add keys to either list via setsockopt(2) through struct sctp_authkey and by passing that to sctp_auth_set_key() which replaces or adds a new auth key. There, sctp_auth_create_key() creates a new sctp_auth_bytes with refcount 1 and in case of replacement drops the reference on the old sctp_auth_bytes. A key can be set active from user space through setsockopt() on the id via sctp_auth_set_active_key(), which iterates through either endpoint_shared_keys and in case of an assoc, invokes (one of various places) sctp_auth_asoc_init_active_key(). sctp_auth_asoc_init_active_key() computes the actual secret from local's and peer's random, hmac and shared key parameters and returns a new key directly as sctp_auth_bytes, that is asoc->asoc_shared_key, plus drops the reference if there was a previous one. The secret, which where we eventually double drop the ref comes from sctp_auth_asoc_set_secret() with intitial refcount of 1, which also stays unchanged eventually in sctp_assoc_update(). This key is later being used for crypto layer to set the key for the hash in crypto_hash_setkey() from sctp_auth_calculate_hmac(). To close the loop: asoc->asoc_shared_key is freshly allocated secret material and independant of the sctp_shared_key management keeping track of only shared keys in endpoints and assocs. Hence, also commit 4184b2a79a76 ("net: sctp: fix memory leak in auth key management") is independant of this bug here since it concerns a different layer (though same structures being used eventually). asoc->asoc_shared_key is reference dropped correctly on assoc destruction in sctp_association_free() and when active keys are being replaced in sctp_auth_asoc_init_active_key(), it always has a refcount of 1. Hence, it's freed prematurely in sctp_assoc_update(). Simple fix is to remove that sctp_auth_key_put() from there which fixes these panics. Fixes: 730fc3d05cd4 ("[SCTP]: Implete SCTP-AUTH parameter processing") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-10-14net: sctp: fix panic on duplicate ASCONF chunksDaniel Borkmann
When receiving a e.g. semi-good formed connection scan in the form of ... -------------- INIT[ASCONF; ASCONF_ACK] -------------> <----------- INIT-ACK[ASCONF; ASCONF_ACK] ------------ -------------------- COOKIE-ECHO --------------------> <-------------------- COOKIE-ACK --------------------- ---------------- ASCONF_a; ASCONF_b -----------------> ... where ASCONF_a equals ASCONF_b chunk (at least both serials need to be equal), we panic an SCTP server! The problem is that good-formed ASCONF chunks that we reply with ASCONF_ACK chunks are cached per serial. Thus, when we receive a same ASCONF chunk twice (e.g. through a lost ASCONF_ACK), we do not need to process them again on the server side (that was the idea, also proposed in the RFC). Instead, we know it was cached and we just resend the cached chunk instead. So far, so good. Where things get nasty is in SCTP's side effect interpreter, that is, sctp_cmd_interpreter(): While incoming ASCONF_a (chunk = event_arg) is being marked !end_of_packet and !singleton, and we have an association context, we do not flush the outqueue the first time after processing the ASCONF_ACK singleton chunk via SCTP_CMD_REPLY. Instead, we keep it queued up, although we set local_cork to 1. Commit 2e3216cd54b1 changed the precedence, so that as long as we get bundled, incoming chunks we try possible bundling on outgoing queue as well. Before this commit, we would just flush the output queue. Now, while ASCONF_a's ASCONF_ACK sits in the corked outq, we continue to process the same ASCONF_b chunk from the packet. As we have cached the previous ASCONF_ACK, we find it, grab it and do another SCTP_CMD_REPLY command on it. So, effectively, we rip the chunk->list pointers and requeue the same ASCONF_ACK chunk another time. Since we process ASCONF_b, it's correctly marked with end_of_packet and we enforce an uncork, and thus flush, thus crashing the kernel. Fix it by testing if the ASCONF_ACK is currently pending and if that is the case, do not requeue it. When flushing the output queue we may relink the chunk for preparing an outgoing packet, but eventually unlink it when it's copied into the skb right before transmission. Joint work with Vlad Yasevich. Fixes: 2e3216cd54b1 ("sctp: Follow security requirement of responding with 1 packet") Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-22net: sctp: fix suboptimal edge-case on non-active active/retrans path selectionDaniel Borkmann
In SCTP, selection of active (T.ACT) and retransmission (T.RET) transports is being done whenever transport control operations (UP, DOWN, PF, ...) are engaged through sctp_assoc_control_transport(). Commits 4c47af4d5eb2 ("net: sctp: rework multihoming retransmission path selection to rfc4960") and a7288c4dd509 ("net: sctp: improve sctp_select_active_and_retran_path selection") have both improved it towards a more fine-grained and optimal path selection. Currently, the selection algorithm for T.ACT and T.RET is as follows: 1) Elect the two most recently used ACTIVE transports T1, T2 for T.ACT, T.RET, where T.ACT<-T1 and T1 is most recently used 2) In case primary path T.PRI not in {T1, T2} but ACTIVE, set T.ACT<-T.PRI and T.RET<-T1 3) If only T1 is ACTIVE from the set, set T.ACT<-T1 and T.RET<-T1 4) If none is ACTIVE, set T.ACT<-best(T.PRI, T.RET, T3) where T3 is the most recently used (if avail) in PF, set T.RET<-T.PRI Prior to above commits, 4) was simply a camp on T.ACT<-T.PRI and T.RET<-T.PRI, ignoring possible paths in PF. Camping on T.PRI is still slightly suboptimal as it can lead to the following scenario: Setup: <A> <B> T1: p1p1 (10.0.10.10) <==> .'`) <==> p1p1 (10.0.10.12) <= T.PRI T2: p1p2 (10.0.10.20) <==> (_ . ) <==> p1p2 (10.0.10.22) net.sctp.rto_min = 1000 net.sctp.path_max_retrans = 2 net.sctp.pf_retrans = 0 net.sctp.hb_interval = 1000 T.PRI is permanently down, T2 is put briefly into PF state (e.g. due to link flapping). Here, the first time transmission is sent over PF path T2 as it's the only non-INACTIVE path, but the retransmitted data-chunks are sent over the INACTIVE path T1 (T.PRI), which is not good. After the patch, it's choosing better transports in both cases by modifying step 4): 4) If none is ACTIVE, set T.ACT_new<-best(T.ACT_old, T3) where T3 is the most recently used (if avail) in PF, set T.RET<-T.ACT_new This will still select a best possible path in PF if available (which can also include T.PRI/T.RET), and set both T.ACT/T.RET to it. In case sctp_assoc_control_transport() *just* put T.ACT_old into INACTIVE as it transitioned from ACTIVE->PF->INACTIVE and stays in INACTIVE just for a very short while before going back ACTIVE, it will guarantee that this path will be reselected for T.ACT/T.RET since T3 (PF) is not available. Previously, this was not possible, as we would only select between T.PRI and T.RET, and a possible T3 would be NULL due to the fact that we have just transitioned T3 in sctp_assoc_control_transport() from PF->INACTIVE and would select a suboptimal path when T.PRI/T.RET have worse properties. In the case that T.ACT_old permanently went to INACTIVE during this transition and there's no PF path available, plus T.PRI and T.RET are INACTIVE as well, we would now camp on T.ACT_old, but if everything is being INACTIVE there's really not much we can do except hoping for a successful HB to bring one of the transports back up again and, thus cause a new selection through sctp_assoc_control_transport(). Now both tests work fine: Case 1: 1. T1 S(ACTIVE) T.ACT T2 S(ACTIVE) T.RET 2. T1 S(ACTIVE) T.ACT, T.RET T2 S(PF) 3. T1 S(ACTIVE) T.ACT, T.RET T2 S(INACTIVE) 5. T1 S(PF) T.ACT, T.RET T2 S(INACTIVE) [ 5.1 T1 S(INACTIVE) T.ACT, T.RET T2 S(INACTIVE) ] 6. T1 S(ACTIVE) T.ACT, T.RET T2 S(INACTIVE) 7. T1 S(ACTIVE) T.ACT T2 S(ACTIVE) T.RET Case 2: 1. T1 S(ACTIVE) T.ACT T2 S(ACTIVE) T.RET 2. T1 S(PF) T2 S(ACTIVE) T.ACT, T.RET 3. T1 S(INACTIVE) T2 S(ACTIVE) T.ACT, T.RET 5. T1 S(INACTIVE) T2 S(PF) T.ACT, T.RET [ 5.1 T1 S(INACTIVE) T2 S(INACTIVE) T.ACT, T.RET ] 6. T1 S(INACTIVE) T2 S(ACTIVE) T.ACT, T.RET 7. T1 S(ACTIVE) T.ACT T2 S(ACTIVE) T.RET Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-22net: sctp: spare unnecessary comparison in sctp_trans_elect_bestDaniel Borkmann
When both transports are the same, we don't have to go down that road only to realize that we will return the very same transport. We are guaranteed that curr is always non-NULL. Therefore, just short-circuit this special case. Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-21sctp: not send SCTP_PEER_ADDR_CHANGE notifications with failed probezhuyj
Since the transport has always been in state SCTP_UNCONFIRMED, it therefore wasn't active before and hasn't been used before, and it always has been, so it is unnecessary to bug the user with a notification. Reported-by: Deepak Khandelwal <khandelwal.deepak.1987@gmail.com> Suggested-by: Vlad Yasevich <vyasevich@gmail.com> Suggested-by: Michael Tuexen <tuexen@fh-muenster.de> Suggested-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Zhu Yanjun <Yanjun.Zhu@windriver.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Acked-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>