Re: [PATCHv2 net] sctp: update frag_point when stream_interleave is set
From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Date: 2018-11-28 08:40:51
Also in:
linux-sctp
On Tue, Nov 27, 2018 at 07:11:50PM +0800, Xin Long wrote:
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: 2f5e3c9df693 ("sctp: introduce sctp_assoc_update_frag_point")
Reported-by: Jakub Audykowicz <redacted>
Signed-off-by: Xin Long <lucien.xin@gmail.com>Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
quoted hunk ↗ jump to hunk
--- net/sctp/associola.c | 7 ++++--- net/sctp/sm_make_chunk.c | 3 +++ 2 files changed, 7 insertions(+), 3 deletions(-)diff --git a/net/sctp/associola.c b/net/sctp/associola.c index 6a28b96..dd77ec3 100644 --- a/net/sctp/associola.c +++ b/net/sctp/associola.c@@ -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. */diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c index 4a4fd19..f4ac6c5 100644 --- a/net/sctp/sm_make_chunk.c +++ b/net/sctp/sm_make_chunk.c@@ -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;-- 2.1.0