From: Numan Siddique <[email protected]>
Presently when a VM's IPv6 stack sends a Neighbor Solicitation request for its
router IP, (mostly when the ND cache entry for the router is in STALE state)
ovn-controller responds with a Neighbor Adv packet (using the action nd_na).
But it doesn't set 'ND_RSO_ROUTER' in the RSO flags (please see RFC4861 page
23).
Because of which, the VM deletes the default route. The default route gets added
again when the next RA is received (but would again gets deleted if its sends
NS request). And this results in disruption of IPv6 traffic.
This patch addresses this issue by adding a new action 'nd_na_router' which is
same as 'nd_na' but it sets the 'ND_RSO_ROUTER' in the RSO flags. ovn-northd
uses this action. A new action is added instead of modifying the existing
'nd_na'
action. This is because
- We cannot set the RSO flags in the "nd_na { ..actions .. }"
- It would be ugly to have something like nd_na { router_flags, ...actions ..
}
Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1567735
Signed-off-by: Numan Siddique <[email protected]>
Acked-by: Mark Michelson <[email protected]>
---
v3 -> v4
-------
Added the required documentation in ovn-sb.xml/ovn-northd.8.xml
v2 -> v3
-------
Updated the commit subject
v1 -> v2
-------
Updated the commit message with the RFC info.
include/ovn/actions.h | 7 +++++++
ovn/controller/pinctrl.c | 23 +++++++++++++--------
ovn/lib/actions.c | 22 ++++++++++++++++++++
ovn/northd/ovn-northd.8.xml | 34 ++++++++++++++++++++++++++----
ovn/northd/ovn-northd.c | 2 +-
ovn/ovn-sb.xml | 41 +++++++++++++++++++++++++++++++++++++
ovn/utilities/ovn-trace.c | 1 +
tests/ovn.at | 5 +++++
8 files changed, 122 insertions(+), 13 deletions(-)
diff --git a/include/ovn/actions.h b/include/ovn/actions.h
index fb8f51509..638465193 100644
--- a/include/ovn/actions.h
+++ b/include/ovn/actions.h
@@ -68,6 +68,7 @@ struct ovn_extend_table;
OVNACT(ICMP6, ovnact_nest) \
OVNACT(TCP_RESET, ovnact_nest) \
OVNACT(ND_NA, ovnact_nest) \
+ OVNACT(ND_NA_ROUTER, ovnact_nest) \
OVNACT(GET_ARP, ovnact_get_mac_bind) \
OVNACT(PUT_ARP, ovnact_put_mac_bind) \
OVNACT(GET_ND, ovnact_get_mac_bind) \
@@ -444,6 +445,12 @@ enum action_opcode {
* The actions, in OpenFlow 1.3 format, follow the action_header.
*/
ACTION_OPCODE_TCP_RESET,
+
+ /* "nd_na_router { ...actions... }" with rso flag 'ND_RSO_ROUTER' set.
+ *
+ * The actions, in OpenFlow 1.3 format, follow the action_header.
+ */
+ ACTION_OPCODE_ND_NA_ROUTER,
};
/* Header. */
diff --git a/ovn/controller/pinctrl.c b/ovn/controller/pinctrl.c
index 6e6aa1caa..305f20649 100644
--- a/ovn/controller/pinctrl.c
+++ b/ovn/controller/pinctrl.c
@@ -81,7 +81,8 @@ static void send_garp_run(struct controller_ctx *ctx,
struct sset *active_tunnels);
static void pinctrl_handle_nd_na(const struct flow *ip_flow,
const struct match *md,
- struct ofpbuf *userdata);
+ struct ofpbuf *userdata,
+ bool is_router);
static void reload_metadata(struct ofpbuf *ofpacts,
const struct match *md);
static void pinctrl_handle_put_nd_ra_opts(
@@ -1154,7 +1155,11 @@ process_packet_in(const struct ofp_header *msg, struct
controller_ctx *ctx)
break;
case ACTION_OPCODE_ND_NA:
- pinctrl_handle_nd_na(&headers, &pin.flow_metadata, &userdata);
+ pinctrl_handle_nd_na(&headers, &pin.flow_metadata, &userdata, false);
+ break;
+
+ case ACTION_OPCODE_ND_NA_ROUTER:
+ pinctrl_handle_nd_na(&headers, &pin.flow_metadata, &userdata, true);
break;
case ACTION_OPCODE_PUT_ND:
@@ -2308,7 +2313,7 @@ reload_metadata(struct ofpbuf *ofpacts, const struct
match *md)
static void
pinctrl_handle_nd_na(const struct flow *ip_flow, const struct match *md,
- struct ofpbuf *userdata)
+ struct ofpbuf *userdata, bool is_router)
{
/* This action only works for IPv6 ND packets, and the switch should only
* send us ND packets this way, but check here just to be sure. */
@@ -2322,13 +2327,15 @@ pinctrl_handle_nd_na(const struct flow *ip_flow, const
struct match *md,
struct dp_packet packet;
dp_packet_use_stub(&packet, packet_stub, sizeof packet_stub);
- /* xxx These flags are not exactly correct. Look at section 7.2.4
- * xxx of RFC 4861. For example, we need to set ND_RSO_ROUTER for
- * xxx router's interfaces and ND_RSO_SOLICITED only if it was
- * xxx requested. */
+ /* These flags are not exactly correct. Look at section 7.2.4
+ * of RFC 4861. */
+ uint32_t rso_flags = ND_RSO_SOLICITED | ND_RSO_OVERRIDE;
+ if (is_router) {
+ rso_flags |= ND_RSO_ROUTER;
+ }
compose_nd_na(&packet, ip_flow->dl_dst, ip_flow->dl_src,
&ip_flow->nd_target, &ip_flow->ipv6_src,
- htonl(ND_RSO_SOLICITED | ND_RSO_OVERRIDE));
+ htonl(rso_flags));
/* Reload previous packet metadata and set actions from userdata. */
set_actions_and_enqueue_msg(&packet, md, userdata);
diff --git a/ovn/lib/actions.c b/ovn/lib/actions.c
index a6945812d..0669cc1c9 100644
--- a/ovn/lib/actions.c
+++ b/ovn/lib/actions.c
@@ -1155,6 +1155,12 @@ parse_ND_NA(struct action_context *ctx)
parse_nested_action(ctx, OVNACT_ND_NA, "nd_ns");
}
+static void
+parse_ND_NA_ROUTER(struct action_context *ctx)
+{
+ parse_nested_action(ctx, OVNACT_ND_NA_ROUTER, "nd_ns");
+}
+
static void
parse_ND_NS(struct action_context *ctx)
{
@@ -1206,6 +1212,12 @@ format_ND_NA(const struct ovnact_nest *nest, struct ds
*s)
format_nested_action(nest, "nd_na", s);
}
+static void
+format_ND_NA_ROUTER(const struct ovnact_nest *nest, struct ds *s)
+{
+ format_nested_action(nest, "nd_na_router", s);
+}
+
static void
format_ND_NS(const struct ovnact_nest *nest, struct ds *s)
{
@@ -1282,6 +1294,14 @@ encode_ND_NA(const struct ovnact_nest *on,
encode_nested_actions(on, ep, ACTION_OPCODE_ND_NA, ofpacts);
}
+static void
+encode_ND_NA_ROUTER(const struct ovnact_nest *on,
+ const struct ovnact_encode_params *ep,
+ struct ofpbuf *ofpacts)
+{
+ encode_nested_actions(on, ep, ACTION_OPCODE_ND_NA_ROUTER, ofpacts);
+}
+
static void
encode_ND_NS(const struct ovnact_nest *on,
const struct ovnact_encode_params *ep,
@@ -2305,6 +2325,8 @@ parse_action(struct action_context *ctx)
parse_TCP_RESET(ctx);
} else if (lexer_match_id(ctx->lexer, "nd_na")) {
parse_ND_NA(ctx);
+ } else if (lexer_match_id(ctx->lexer, "nd_na_router")) {
+ parse_ND_NA_ROUTER(ctx);
} else if (lexer_match_id(ctx->lexer, "nd_ns")) {
parse_ND_NS(ctx);
} else if (lexer_match_id(ctx->lexer, "get_arp")) {
diff --git a/ovn/northd/ovn-northd.8.xml b/ovn/northd/ovn-northd.8.xml
index d6d270b39..1d68f1aab 100644
--- a/ovn/northd/ovn-northd.8.xml
+++ b/ovn/northd/ovn-northd.8.xml
@@ -1230,10 +1230,36 @@ arp.sha = <var>external_mac</var>;
Reply to IPv6 Neighbor Solicitations. These flows reply to
Neighbor Solicitation requests for the router's own IPv6
address and load balancing IPv6 VIPs and populate the logical
- router's mac binding table. For each router port <var>P</var> that
- owns IPv6 address or has load balancing VIP <var>A</var>, solicited
- node address <var>S</var>, and Ethernet address <var>E</var>, a
- priority-90 flow matches <code>inport == <var>P</var> &&
+ router's mac binding table.
+ </p>
+
+ <p>
+ For each router port <var>P</var> that
+ owns IPv6 address <var>A</var>, solicited node address <var>S</var>,
+ and Ethernet address <var>E</var>, a priority-90 flow matches
+ <code>inport == <var>P</var> &&
+ nd_ns && ip6.dst == {<var>A</var>, <var>E</var>} &&
+ nd.target == <var>A</var></code> with the following actions:
+ </p>
+
+ <pre>
+put_nd(inport, ip6.src, nd.sll);
+nd_na_router {
+ eth.src = <var>E</var>;
+ ip6.src = <var>A</var>;
+ nd.target = <var>A</var>;
+ nd.tll = <var>E</var>;
+ outport = inport;
+ flags.loopback = 1;
+ output;
+};
+ </pre>
+
+ <p>
+ For each router port <var>P</var> that has load balancing VIP
+ <var>A</var>, solicited node address <var>S</var>, and Ethernet
+ address <var>E</var>, a priority-90 flow matches
+ <code>inport == <var>P</var> &&
nd_ns && ip6.dst == {<var>A</var>, <var>E</var>} &&
nd.target == <var>A</var></code> with the following actions:
</p>
diff --git a/ovn/northd/ovn-northd.c b/ovn/northd/ovn-northd.c
index cef4d978f..0e06776ad 100644
--- a/ovn/northd/ovn-northd.c
+++ b/ovn/northd/ovn-northd.c
@@ -5224,7 +5224,7 @@ build_lrouter_flows(struct hmap *datapaths, struct hmap
*ports,
ds_clear(&actions);
ds_put_format(&actions,
"put_nd(inport, ip6.src, nd.sll); "
- "nd_na { "
+ "nd_na_router { "
"eth.src = %s; "
"ip6.src = %s; "
"nd.target = %s; "
diff --git a/ovn/ovn-sb.xml b/ovn/ovn-sb.xml
index 5d237743b..b17110e48 100644
--- a/ovn/ovn-sb.xml
+++ b/ovn/ovn-sb.xml
@@ -1367,6 +1367,47 @@
</p>
</dd>
+ <dt>
+ <code>nd_na_router { <var>action</var>; </code>...<code> };</code>
+ </dt>
+
+ <dd>
+ <p>
+ Temporarily replaces the IPv6 neighbor solicitation packet
+ being processed by an IPv6 neighbor advertisement (NA)
+ packet, sets ND_NSO_ROUTER in the RSO flags and executes each
+ nested <var>action</var> on the NA packet. Actions following
+ the <code>nd_na_router</code> action, if any, apply to the
+ original, unmodified packet.
+ </p>
+
+ <p>
+ The NA packet that this action operates on is initialized based on
+ the IPv6 packet being processed, as follows. These are default
+ values that the nested actions will probably want to change:
+ </p>
+
+ <ul>
+ <li><code>eth.dst</code> exchanged with <code>eth.src</code></li>
+ <li><code>eth.type = 0x86dd</code></li>
+ <li><code>ip6.dst</code> copied from <code>ip6.src</code></li>
+ <li><code>ip6.src</code> copied from <code>nd.target</code></li>
+ <li><code>icmp6.type = 136</code> (Neighbor Advertisement)</li>
+ <li><code>nd.target</code> unchanged</li>
+ <li><code>nd.sll = 00:00:00:00:00:00</code></li>
+ <li><code>nd.tll</code> copied from <code>eth.dst</code></li>
+ </ul>
+
+ <p>
+ The ND packet has the same VLAN header, if any, as the IPv6 packet
+ it replaces.
+ </p>
+
+ <p>
+ <b>Prerequisite:</b> <code>nd_ns</code>
+ </p>
+ </dd>
+
<dt><code>get_nd(<var>P</var>, <var>A</var>);</code></dt>
<dd>
diff --git a/ovn/utilities/ovn-trace.c b/ovn/utilities/ovn-trace.c
index 9c19b5b9a..1fd48f22e 100644
--- a/ovn/utilities/ovn-trace.c
+++ b/ovn/utilities/ovn-trace.c
@@ -1927,6 +1927,7 @@ trace_actions(const struct ovnact *ovnacts, size_t
ovnacts_len,
break;
case OVNACT_ND_NA:
+ case OVNACT_ND_NA_ROUTER:
execute_nd_na(ovnact_get_ND_NA(a), dp, uflow, table_id, pipeline,
super);
break;
diff --git a/tests/ovn.at b/tests/ovn.at
index 7a136478c..8d9519e66 100644
--- a/tests/ovn.at
+++ b/tests/ovn.at
@@ -1033,6 +1033,11 @@ nd_na { eth.src = 12:34:56:78:9a:bc; nd.tll =
12:34:56:78:9a:bc; outport = inpor
formats as nd_na { eth.src = 12:34:56:78:9a:bc; nd.tll =
12:34:56:78:9a:bc; outport = inport; inport = ""; output; };
encodes as
controller(userdata=00.00.00.03.00.00.00.00.00.19.00.10.80.00.08.06.12.34.56.78.9a.bc.00.00.00.19.00.10.80.00.42.06.12.34.56.78.9a.bc.00.00.ff.ff.00.18.00.00.23.20.00.06.00.20.00.00.00.00.00.01.1c.04.00.01.1e.04.00.19.00.10.00.01.1c.04.00.00.00.00.00.00.00.00.ff.ff.00.10.00.00.23.20.00.0e.ff.f8.40.00.00.00)
has prereqs nd_ns
+# nd_na_router
+nd_na_router { eth.src = 12:34:56:78:9a:bc; nd.tll = 12:34:56:78:9a:bc;
outport = inport; inport = ""; /* Allow sending out inport. */ output; };
+ formats as nd_na_router { eth.src = 12:34:56:78:9a:bc; nd.tll =
12:34:56:78:9a:bc; outport = inport; inport = ""; output; };
+ encodes as
controller(userdata=00.00.00.0c.00.00.00.00.00.19.00.10.80.00.08.06.12.34.56.78.9a.bc.00.00.00.19.00.10.80.00.42.06.12.34.56.78.9a.bc.00.00.ff.ff.00.18.00.00.23.20.00.06.00.20.00.00.00.00.00.01.1c.04.00.01.1e.04.00.19.00.10.00.01.1c.04.00.00.00.00.00.00.00.00.ff.ff.00.10.00.00.23.20.00.0e.ff.f8.40.00.00.00)
+ has prereqs nd_ns
# get_nd
get_nd(outport, ip6.dst);
--
2.17.0
_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
