@@ -12,41 +12,6 @@ one router to another, this doesn't seem to matter (just put more than
one connection between them), but for connections between a router and
a switch it might matter because a switch has only one router port.
-** OVN_SB schema
-
-*** Allow output to ingress port
-
-Sometimes when a packet ingresses into a router, it has to egress the
-same port. One example is a "one-armed" router that has multiple
-routes on a single port (or in which a host is (mis)configured to send
-every IP packet to the router, e.g. due to a bad netmask). Another is
-when a router needs to send an ICMP reply to an ingressing packet.
-
-To some degree this problem is layered, because there are two
-different notions of "ingress port". The first is the OpenFlow
-ingress port, essentially a physical port identifier. This is
-implemented as part of ovs-vswitchd's OpenFlow implementation. It
-prevents a reply from being sent across the tunnel on which it
-arrived. It is questionable whether this OpenFlow feature is useful
-to OVN. (OVN already has to override it to allow a packet from one
-nested container to be forwarded to a different nested container.)
-OVS make it possible to disable this feature of OpenFlow by setting
-the OpenFlow input port field to 0. (If one does this too early, of
-course, it means that there's no way to actually match on the input
-port in the OpenFlow flow tables, but one can work around that by
-instead setting the input port just before the output action, possibly
-wrapping these actions in push/pop pairs to preserve the input port
-for later.)
-
-The second is the OVN logical ingress port, which is implemented in
-ovn-controller as part of the logical abstraction, using an OVS
-register. Dropping packets directed to the logical ingress port is
-implemented through an OpenFlow table not directly visible to the
-logical flow table. Currently this behavior can't be disabled, but
-various ways to ensure it could be implemented, e.g. the same as for
-OpenFlow by allowing the logical inport to be zeroed, or by
-introducing a new action that ignores the inport.
-
** New OVN logical actions
*** arp
@@ -19,6 +19,7 @@
#include "dynamic-string.h"
#include "json.h"
#include "lex.h"
+#include "logical-fields.h"
#include "match.h"
#include "ofp-actions.h"
#include "shash.h"
@@ -2810,8 +2811,17 @@ parse_assignment(struct expr_context *ctx, const struct simap *ports,
uint32_t port = simap_get(ports, c->string);
bitwise_put(port, &sf->value,
sf->field->n_bytes, 0, sf->field->n_bits);
- bitwise_put(UINT64_MAX, &sf->mask,
- sf->field->n_bytes, 0, sf->field->n_bits);
+ bitwise_one(&sf->mask, sf->field->n_bytes, 0, sf->field->n_bits);
+
+ /* If the logical input port is being zeroed, clear the OpenFlow
+ * ingress port also, to allow a packet to be sent back to its
+ * origin. */
+ if (!port && sf->field->id == MFF_LOG_INPORT) {
+ sf = ofpact_put_SET_FIELD(ofpacts);
+ sf->field = mf_from_id(MFF_IN_PORT);
+ bitwise_one(&sf->mask,
+ sf->field->n_bytes, 0, sf->field->n_bits);
+ }
}
exit_destroy_cs:
@@ -782,7 +782,11 @@
<p>
Output to the input port is implicitly dropped, that is,
<code>output</code> becomes a no-op if <code>outport</code> ==
- <code>inport</code>.
+ <code>inport</code>. Occasionally it may be useful to override
+ this behavior, e.g. to send an ARP reply to an ARP request; to do
+ so, use <code>inport = "";</code> to set the logical input port to
+ an empty string (which should not be used as the name of any
+ logical port).
</p>
</dd>
@@ -454,6 +454,7 @@ reg0 = reg1; => actions=move:OXM_OF_PKT_REG0[0..31]->OXM_OF_PKT_REG0[32..63], pr
vlan.pcp = reg0[0..2]; => actions=move:OXM_OF_PKT_REG0[32..34]->NXM_OF_VLAN_TCI[13..15], prereqs=vlan.tci[12]
reg0[10] = vlan.pcp[1]; => actions=move:NXM_OF_VLAN_TCI[14]->OXM_OF_PKT_REG0[42], prereqs=vlan.tci[12]
outport = inport; => actions=move:NXM_NX_REG6[]->NXM_NX_REG7[], prereqs=1
+inport = ""; => actions=set_field:0->reg6,set_field:0->in_port, prereqs=1
reg0 <-> reg1; => actions=push:OXM_OF_PKT_REG0[0..31],push:OXM_OF_PKT_REG0[32..63],pop:OXM_OF_PKT_REG0[0..31],pop:OXM_OF_PKT_REG0[32..63], prereqs=1
vlan.pcp <-> reg0[0..2]; => actions=push:OXM_OF_PKT_REG0[32..34],push:NXM_OF_VLAN_TCI[13..15],pop:OXM_OF_PKT_REG0[32..34],pop:NXM_OF_VLAN_TCI[13..15], prereqs=vlan.tci[12]
reg0[10] <-> vlan.pcp[1]; => actions=push:NXM_OF_VLAN_TCI[14],push:OXM_OF_PKT_REG0[42],pop:NXM_OF_VLAN_TCI[14],pop:OXM_OF_PKT_REG0[42], prereqs=vlan.tci[12]