sctp: introduce sctp_assoc_set_pmtu

All changes to asoc PMTU should now go through this wrapper, making it
easier to track them and to do other actions upon it.

Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 15 insertions, 9 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index 05594b248e52..c5e244be8f1e 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -2097,6 +2097,7 @@ int sctp_assoc_update(struct sctp_association *old,
 
 __u32 sctp_association_get_next_tsn(struct sctp_association *);
 
+void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu);
 void sctp_assoc_sync_pmtu(struct sctp_association *asoc);
 void sctp_assoc_rwnd_increase(struct sctp_association *, unsigned int);
 void sctp_assoc_rwnd_decrease(struct sctp_association *, unsigned int);
diff --git a/net/sctp/associola.c b/net/sctp/associola.c
index c5ed09cfa842..85b362324084 100644
--- a/net/sctp/associola.c
+++ b/net/sctp/associola.c
@@ -660,13 +660,9 @@ struct sctp_transport *sctp_assoc_add_peer(struct sctp_association *asoc,
          * If not and the current association PMTU is higher than the new
          * peer's PMTU, reset the association PMTU to the new peer's PMTU.
          */
-        if (asoc->pathmtu)
-                asoc->pathmtu = min_t(int, peer->pathmtu, asoc->pathmtu);
-        else
-                asoc->pathmtu = peer->pathmtu;
-
-        pr_debug("%s: association:%p PMTU set to %d\n", __func__, asoc,
-                 asoc->pathmtu);
+        sctp_assoc_set_pmtu(asoc, asoc->pathmtu ?
+                                  min_t(int, peer->pathmtu, asoc->pathmtu) :
+                                  peer->pathmtu);
 
         peer->pmtu_pending = 0;
 
@@ -1374,6 +1370,15 @@ sctp_assoc_choose_alter_transport(struct sctp_association *asoc,
         }
 }
 
+void sctp_assoc_set_pmtu(struct sctp_association *asoc, __u32 pmtu)
+{
+        if (asoc->pathmtu != pmtu)
+                asoc->pathmtu = pmtu;
+
+        pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
+                 asoc->pathmtu, asoc->frag_point);
+}
+
 /* Update the association's pmtu and frag_point by going through all the
  * transports. This routine is called when a transport's PMTU has changed.
  */
@@ -1397,7 +1402,7 @@ void sctp_assoc_sync_pmtu(struct sctp_association *asoc)
                         pmtu = t->pathmtu;
         }
 
-        asoc->pathmtu = pmtu;
+        sctp_assoc_set_pmtu(asoc, pmtu);
         asoc->frag_point = sctp_frag_point(asoc, pmtu);
 
         pr_debug("%s: asoc:%p, pmtu:%d, frag_point:%d\n", __func__, asoc,
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 80835ac26d2c..eeec81d5c485 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2539,7 +2539,7 @@ static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params,
                         trans->pathmtu = params->spp_pathmtu;
                         sctp_assoc_sync_pmtu(asoc);
                 } else if (asoc) {
-                        asoc->pathmtu = params->spp_pathmtu;
+                        sctp_assoc_set_pmtu(asoc, params->spp_pathmtu);
                 } else {
                         sp->pathmtu = params->spp_pathmtu;
                 }