This is an proposed enhancement to
"Implement OpenFlow support for MPLS, for up to 3 labels."
It is in preparation for not adding flows to the datapath
which have more MPLS LSEs than the datapath supports.
Signed-off-by: Simon Horman <ho...@verge.net.au>
---
ofproto/ofproto-dpif.c | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 59 insertions(+)
diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index 62c1e4c..6da8e5c 100644
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -256,6 +256,10 @@ struct dpif_backer {
* OVS_USERSPACE_ATTR_USERDATA in OVS_ACTION_ATTR_USERSPACE actions.
* False if the datapath supports only 8-byte (or shorter) userdata. */
bool variable_length_userdata;
+
+ /* Maximum number of MPLS label stack entries that the datapath supports
+ * in a match */
+ size_t max_mpls_depth;
};
/* All existing ofproto_backer instances, indexed by ofproto->up.type. */
@@ -781,6 +785,7 @@ struct odp_garbage {
};
static bool check_variable_length_userdata(struct dpif_backer *backer);
+static size_t check_max_mpls_depth(struct dpif_backer *backer);
static int
open_dpif_backer(const char *type, struct dpif_backer **backerp)
@@ -881,6 +886,7 @@ open_dpif_backer(const char *type, struct dpif_backer
**backerp)
return error;
}
backer->variable_length_userdata = check_variable_length_userdata(backer);
+ backer->max_mpls_depth = check_max_mpls_depth(backer);
if (backer->recv_set_enable) {
udpif_set_threads(backer->udpif, n_handlers, n_revalidators);
@@ -965,6 +971,59 @@ check_variable_length_userdata(struct dpif_backer *backer)
}
}
+/* Tests the MPLS label stack depth supported by 'backer''s datapath.
+ *
+ * Returns the number of elements in a struct flow's mpls_lse field
+ * if the datapath supports at least that many entries in an
+ * MPLS label stack.
+ * Otherwise returns the number of MPLS push actions supported by
+ * the datapath. */
+static size_t
+check_max_mpls_depth(struct dpif_backer *backer)
+{
+ size_t i;
+ struct flow flow;
+ int error;
+
+ /* If ARRAY_SIZE(flow.mpls_lse) becomes large then it might
+ * make more sense to do a binary search here. */
+ for (i = ARRAY_SIZE(flow.mpls_lse) - 1; i > 0; i--) {
+ struct odputil_keybuf keybuf;
+ struct ofpbuf key;
+
+ memset(&flow, 0, sizeof flow);
+ flow.dl_type = htons(ETH_TYPE_MPLS);
+ flow_set_mpls_bos(&flow, ARRAY_SIZE(flow.mpls_lse) - 1, 1);
+
+ ofpbuf_use_stack(&key, &keybuf, sizeof keybuf);
+ odp_flow_key_from_flow(&key, &flow, 0);
+
+ error = dpif_flow_put(backer->dpif, DPIF_FP_CREATE, key.data, key.size,
+ NULL, 0, NULL, 0, NULL);
+ if (!error) {
+ error = dpif_flow_del(backer->dpif, key.data, key.size, NULL);
+ if (error) {
+ goto err;
+ }
+ i++;
+ break;
+ } else if (error != EINVAL) {
+ goto err;
+ }
+ }
+
+ VLOG_INFO("%s: MPLS label stack length probed as %"PRIuSIZE,
+ dpif_name(backer->dpif), i);
+ return i;
+
+err:
+ /* Something odd happened. We're not sure how large an
+ * MPLS label stack the datapath supports. Default to 0. */
+ VLOG_WARN("%s: mpls stack length feature probe failed (%s)",
+ dpif_name(backer->dpif), ovs_strerror(error));
+ return 0;
+}
+
static int
construct(struct ofproto *ofproto_)
{
--
1.8.4
_______________________________________________
dev mailing list
dev@openvswitch.org
http://openvswitch.org/mailman/listinfo/dev
