sctp: Fix SCTP_MAXSEG socket option to comply to spec.
We had a bug that we never stored the user-defined value for
MAXSEG when setting the value on an association. Thus future
PMTU events ended up re-writing the frag point and increasing
it past user limit. Additionally, when setting the option on
the socket/endpoint, we effect all current associations, which
is against spec.
Now, we store the user 'maxseg' value along with the computed
'frag_point'. We inherit 'maxseg' from the socket at association
creation and use it as an upper limit for 'frag_point' when its
set.
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index d16a304..8a6d529 100644
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -486,15 +486,16 @@
}
/* Break down data chunks at this point. */
-static inline int sctp_frag_point(const struct sctp_sock *sp, int pmtu)
+static inline int sctp_frag_point(const struct sctp_association *asoc, int pmtu)
{
+ struct sctp_sock *sp = sctp_sk(asoc->base.sk);
int frag = pmtu;
frag -= sp->pf->af->net_header_len;
frag -= sizeof(struct sctphdr) + sizeof(struct sctp_data_chunk);
- if (sp->user_frag)
- frag = min_t(int, frag, sp->user_frag);
+ if (asoc->user_frag)
+ frag = min_t(int, frag, asoc->user_frag);
frag = min_t(int, frag, SCTP_MAX_CHUNK_LEN);