linux.git/net/sctp/ulpqueue.c, branch v4.15

sctp: fix the issue that a __u16 variable may overflow in sctp_ulpq_renege

2017-12-18T18:21:46+00:00

Now when reneging events in sctp_ulpq_renege(), the variable freed
could be increased by a __u16 value twice while freed is of __u16
type. It means freed may overflow at the second addition.

This patch is to fix it by using __u32 type for 'freed', while at
it, also to remove 'if (chunk)' check, as all renege commands are
generated in sctp_eat_data and it can't be NULL.

Reported-by: Marcelo Ricardo Leitner 
Signed-off-by: Xin Long 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

sctp: fix missing wake ups in some situations

2017-09-08T17:02:47+00:00

Commit fb586f25300f ("sctp: delay calls to sk_data_ready() as much as
possible") minimized the number of wake ups that are triggered in case
the association receives a packet with multiple data chunks on it and/or
when io_events are enabled and then commit 0970f5b36659 ("sctp: signal
sk_data_ready earlier on data chunks reception") moved the wake up to as
soon as possible. It thus relies on the state machine running later to
clean the flag that the event was already generated.

The issue is that there are 2 call paths that calls
sctp_ulpq_tail_event() outside of the state machine, causing the flag to
linger and possibly omitting a needed wake up in the sequence.

One of the call paths is when enabling SCTP_SENDER_DRY_EVENTS via
setsockopt(SCTP_EVENTS), as noticed by Harald Welte. The other is when
partial reliability triggers removal of chunks from the send queue when
the application calls sendmsg().

This commit fixes it by not setting the flag in case the socket is not
owned by the user, as it won't be cleaned later. This works for
user-initiated calls and also for rx path processing.

Fixes: fb586f25300f ("sctp: delay calls to sk_data_ready() as much as possible")
Reported-by: Harald Welte 
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: remove the typedef sctp_data_chunk_t

2017-07-01T16:08:42+00:00

This patch is to remove the typedef sctp_data_chunk_t, and replace
with struct sctp_data_chunk in the places where it's using this
typedef.

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: define the member stream as an object instead of pointer in asoc

2017-06-02T17:56:26+00:00

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 
Signed-off-by: David S. Miller

sctp: prepare asoc stream for stream reconf

2017-01-07T02:07:26+00:00

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 
Reviewed-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: Remove some redundant code

2016-09-19T05:34:01+00:00

In commit 311b21774f13 ("sctp: simplify sk_receive_queue locking"), a call
to 'skb_queue_splice_tail_init()' has been made explicit. Previously it was
hidden in 'sctp_skb_list_tail()'

Now, the code around it looks redundant. The '_init()' part of
'skb_queue_splice_tail_init()' should already do the same.

Signed-off-by: Christophe JAILLET 
Acked-by: Marcelo Ricardo Leitner 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

sctp: allow delivering notifications after receiving SHUTDOWN

2016-07-31T05:06:22+00:00

Prior to this patch, once sctp received SHUTDOWN or shutdown with RD,
sk->sk_shutdown would be set with RCV_SHUTDOWN, and all events would
be dropped in sctp_ulpq_tail_event(). It would cause:

1. some notifications couldn't be received by users. like
   SCTP_SHUTDOWN_COMP generated by sctp_sf_do_4_C().

2. sctp would also never trigger sk_data_ready when the association
   was closed, making it harder to identify the end of the association
   by calling recvmsg() and getting an EOF. It was not convenient for
   kernel users.

The check here should be stopping delivering DATA chunks after receiving
SHUTDOWN, and stopping delivering ANY chunks after sctp_close().

So this patch is to allow notifications to enqueue into receive queue
even if sk->sk_shutdown is set to RCV_SHUTDOWN in sctp_ulpq_tail_event,
but if sk->sk_shutdown == RCV_SHUTDOWN | SEND_SHUTDOWN, it drops all
events.

Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: signal sk_data_ready earlier on data chunks reception

2016-05-02T01:06:10+00:00

Dave Miller pointed out that fb586f25300f ("sctp: delay calls to
sk_data_ready() as much as possible") may insert latency specially if
the receiving application is running on another CPU and that it would be
better if we signalled as early as possible.

This patch thus basically inverts the logic on fb586f25300f and signals
it as early as possible, similar to what we had before.

Fixes: fb586f25300f ("sctp: delay calls to sk_data_ready() as much as possible")
Reported-by: Dave Miller 
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: simplify sk_receive_queue locking

2016-04-15T21:22:20+00:00

SCTP already serializes access to rcvbuf through its sock lock:
sctp_recvmsg takes it right in the start and release at the end, while
rx path will also take the lock before doing any socket processing. On
sctp_rcv() it will check if there is an user using the socket and, if
there is, it will queue incoming packets to the backlog. The backlog
processing will do the same. Even timers will do such check and
re-schedule if an user is using the socket.

Simplifying this will allow us to remove sctp_skb_list_tail and get ride
of some expensive lockings.  The lists that it is used on are also
mangled with functions like __skb_queue_tail and __skb_unlink in the
same context, like on sctp_ulpq_tail_event() and sctp_clear_pd().
sctp_close() will also purge those while using only the sock lock.

Therefore the lockings performed by sctp_skb_list_tail() are not
necessary. This patch removes this function and replaces its calls with
just skb_queue_splice_tail_init() instead.

The biggest gain is at sctp_ulpq_tail_event(), because the events always
contain a list, even if it's queueing a single skb and this was
triggering expensive calls to spin_lock_irqsave/_irqrestore for every
data chunk received.

As SCTP will deliver each data chunk on a corresponding recvmsg, the
more effective the change will be.
Before this patch, with chunks with 30 bytes:
netperf -t SCTP_STREAM -H 192.168.1.2 -cC -l 60 -- -m 30 -S 400000
400000 -s 400000 400000
on a 10Gbit link with 1500 MTU:

SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.1.1 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

425984 425984     30    60.00       137.45   7.34     7.36     52.504  52.608

With it:

SCTP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 192.168.1.1 () port 0 AF_INET
Recv   Send    Send                          Utilization       Service Demand
Socket Socket  Message  Elapsed              Send     Recv     Send    Recv
Size   Size    Size     Time     Throughput  local    remote   local   remote
bytes  bytes   bytes    secs.    10^6bits/s  % S      % S      us/KB   us/KB

425984 425984     30    60.00       179.10   7.97     6.70     43.740  36.788

Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: delay calls to sk_data_ready() as much as possible

2016-04-14T03:04:44+00:00

Currently processing of multiple chunks in a single SCTP packet leads to
multiple calls to sk_data_ready, causing multiple wake up signals which
are costy and doesn't make it wake up any faster.

With this patch it will note that the wake up is pending and will do it
before leaving the state machine interpreter, latest place possible to
do it realiably and cleanly.

Note that sk_data_ready events are not dependent on asocs, unlike waking
up writers.

v2: series re-checked
v3: use local vars to cleanup the code, suggested by Jakub Sitnicki
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller