Re: [PATCH 2/4] sctp: Add ip option support

On Tue, Dec 12, 2017 at 02:08:00PM -0200, Marcelo Ricardo Leitner wrote:

Hi Richard,

On Mon, Nov 27, 2017 at 07:31:21PM +0000, Richard Haines wrote:
...

quoted

--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c

@@ -3123,8 +3123,10 @@ static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, unsigned
 
 	if (asoc) {
 		if (val == 0) {
+			struct sctp_af *af = sp->pf->af;
 			val = asoc->pathmtu;
-			val -= sp->pf->af->net_header_len;
+			val -= af->ip_options_len(asoc->base.sk);
+			val -= af->net_header_len;
 			val -= sizeof(struct sctphdr) +
 					sizeof(struct sctp_data_chunk);
 		}

Right below here there is a call to sctp_frag_point(). That function
also needs this tweak.

Yes, we should simplify all these calculations. I have a patch to use
sctp_frag_point on where it is currently recalculating it on
sctp_datamsg_from_user(), but probably should include other places as
well.

I have no further comments on this patchset other than the above and
LGTM.
Thanks Richard.

  Marcelo