[IPSEC]: Kill obsolete get_mss function
Now that we've switched over to storing MTUs in the xfrm_dst entries,
we no longer need the dst's get_mss methods. This patch gets rid of
them.
It also documents the fact that our MTU calculation is not optimal
for ESP.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index cbb0ba3..0db9e57 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -1192,46 +1192,6 @@
EXPORT_SYMBOL(xfrm_bundle_ok);
-/* Well... that's _TASK_. We need to scan through transformation
- * list and figure out what mss tcp should generate in order to
- * final datagram fit to mtu. Mama mia... :-)
- *
- * Apparently, some easy way exists, but we used to choose the most
- * bizarre ones. :-) So, raising Kalashnikov... tra-ta-ta.
- *
- * Consider this function as something like dark humour. :-)
- */
-static int xfrm_get_mss(struct dst_entry *dst, u32 mtu)
-{
- int res = mtu - dst->header_len;
-
- for (;;) {
- struct dst_entry *d = dst;
- int m = res;
-
- do {
- struct xfrm_state *x = d->xfrm;
- if (x) {
- spin_lock_bh(&x->lock);
- if (x->km.state == XFRM_STATE_VALID &&
- x->type && x->type->get_max_size)
- m = x->type->get_max_size(d->xfrm, m);
- else
- m += x->props.header_len;
- spin_unlock_bh(&x->lock);
- }
- } while ((d = d->child) != NULL);
-
- if (m <= mtu)
- break;
- res -= (m - mtu);
- if (res < 88)
- return mtu;
- }
-
- return res + dst->header_len;
-}
-
int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo)
{
int err = 0;
@@ -1252,8 +1212,6 @@
dst_ops->negative_advice = xfrm_negative_advice;
if (likely(dst_ops->link_failure == NULL))
dst_ops->link_failure = xfrm_link_failure;
- if (likely(dst_ops->get_mss == NULL))
- dst_ops->get_mss = xfrm_get_mss;
if (likely(afinfo->garbage_collect == NULL))
afinfo->garbage_collect = __xfrm_garbage_collect;
xfrm_policy_afinfo[afinfo->family] = afinfo;
@@ -1281,7 +1239,6 @@
dst_ops->check = NULL;
dst_ops->negative_advice = NULL;
dst_ops->link_failure = NULL;
- dst_ops->get_mss = NULL;
afinfo->garbage_collect = NULL;
}
}
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 9d206c2..8b9a474 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -1026,6 +1026,12 @@
}
EXPORT_SYMBOL(xfrm_state_delete_tunnel);
+/*
+ * This function is NOT optimal. For example, with ESP it will give an
+ * MTU that's usually two bytes short of being optimal. However, it will
+ * usually give an answer that's a multiple of 4 provided the input is
+ * also a multiple of 4.
+ */
int xfrm_state_mtu(struct xfrm_state *x, int mtu)
{
int res = mtu;