Commit 4135cce7 authored Nov 27, 2018 by Xin Long Committed by David S. Miller Nov 30, 2018

sctp: update frag_point when stream_interleave is set



sctp_assoc_update_frag_point() should be called whenever asoc->pathmtu
changes, but we missed one place in sctp_association_init(). It would
cause frag_point is zero when sending data.

As says in Jakub's reproducer, if sp->pathmtu is set by socketopt, the
new asoc->pathmtu inherits it in sctp_association_init(). Later when
transports are added and their pmtu >= asoc->pathmtu, it will never
call sctp_assoc_update_frag_point() to set frag_point.

This patch is to fix it by updating frag_point after asoc->pathmtu is
set as sp->pathmtu in sctp_association_init(). Note that it moved them
after sctp_stream_init(), as stream->si needs to be set first.

Frag_point's calculation is also related with datachunk's type, so it
needs to update frag_point when stream->si may be changed in
sctp_process_init().

v1->v2:
  - call sctp_assoc_update_frag_point() separately in sctp_process_init
    and sctp_association_init, per Marcelo's suggestion.

Fixes: 2f5e3c9d ("sctp: introduce sctp_assoc_update_frag_point")
Reported-by: Jakub Audykowicz <jakub.audykowicz@gmail.com>
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>

parent 9410d386

net/sctp/associola.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -118,9 +118,6 @@ static struct sctp_association *sctp_association_init(
		asoc->flowlabel = sp->flowlabel;
		asoc->dscp = sp->dscp;

		/* Initialize default path MTU. */
		asoc->pathmtu = sp->pathmtu;

		/* Set association default SACK delay */
		asoc->sackdelay = msecs_to_jiffies(sp->sackdelay);
		asoc->sackfreq = sp->sackfreq;
		@@ -252,6 +249,10 @@ static struct sctp_association *sctp_association_init(
		0, gfp))
		goto fail_init;

		/* Initialize default path MTU. */
		asoc->pathmtu = sp->pathmtu;
		sctp_assoc_update_frag_point(asoc);

		/* Assume that peer would support both address types unless we are
		* told otherwise.
		*/

net/sctp/sm_make_chunk.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -2462,6 +2462,9 @@ int sctp_process_init(struct sctp_association asoc, struct sctp_chunk chunk,
		asoc->c.sinit_max_instreams, gfp))
		goto clean_up;

		/* Update frag_point when stream_interleave may get changed. */
		sctp_assoc_update_frag_point(asoc);

		if (!asoc->temp && sctp_assoc_set_id(asoc, gfp))
		goto clean_up;

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