summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorPim van Pelt <pim@ipng.nl>2024-03-08 09:27:40 +0100
committerNeale Ranns <neale@graphiant.com>2024-04-09 04:26:21 +0000
commit2a7bc81ae302b02e8e0d4eec7db82c1ca15b7f7a (patch)
tree46572a13e4be6271032862c1ab18e17e35515903
parent0bfce6b7243af63c74823c78a9c98377079efec7 (diff)
vnet: fix ARP for unnumbered
On unnumbered interfaces, ARP fails because there is no attached route. Allow replies to peer-to-peer addresses on unnumbered interfaces: eg. 192.0.2.1/32 <-> 192.0.2.2/32 Type: fix Change-Id: Ibeb8d8ebc8d58d5bfb0724739a17694e0217356e Signed-off-by: Pim van Pelt <pim@ipng.nl>
-rw-r--r--src/vnet/arp/arp.c29
-rw-r--r--test/test_neighbor.py22
2 files changed, 30 insertions, 21 deletions
diff --git a/src/vnet/arp/arp.c b/src/vnet/arp/arp.c
index cacdd71e381..43b2a93a7b3 100644
--- a/src/vnet/arp/arp.c
+++ b/src/vnet/arp/arp.c
@@ -423,6 +423,10 @@ arp_reply (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
}
+ dst_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0),
+ &arp0->ip4_over_ethernet[1].ip4, 32);
+ conn_sw_if_index0 = fib_entry_get_any_resolving_interface (dst_fei);
+
{
/*
* we're looking for FIB entries that indicate the source
@@ -509,24 +513,20 @@ arp_reply (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
while (!attached &&
!fib_entry_is_sourced (src_fei, FIB_SOURCE_DEFAULT_ROUTE));
- if (!attached)
+ if (!attached &&
+ !arp_unnumbered (p0, sw_if_index0, conn_sw_if_index0))
{
/*
- * the matching route is a not attached, i.e. it was
- * added as a result of routing, rather than interface/ARP
- * configuration. If the matching route is not a host route
- * (i.e. a /32)
+ * the matching route is a not attached and not unnumbered,
+ * i.e. it was added as a result of routing, rather than
+ * interface/ARP configuration. If the matching route is not
+ * a host route (i.e. a /32)
*/
error0 = ARP_ERROR_L3_SRC_ADDRESS_NOT_LOCAL;
goto drop;
}
}
- dst_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0),
- &arp0->ip4_over_ethernet[1].ip4,
- 32);
- conn_sw_if_index0 = fib_entry_get_any_resolving_interface (dst_fei);
-
switch (arp_dst_fib_check (dst_fei, &dst_flags))
{
case ARP_DST_FIB_ADJ:
@@ -619,9 +619,9 @@ arp_reply (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
sw_if_index0 != fib_entry_get_resolving_interface (src_fei))
{
/*
- * The interface the ARP is sent to or was received on is not the
- * interface on which the covering prefix is configured.
- * Maybe this is a case for unnumbered.
+ * The interface the ARP is sent to or was received on is
+ * not the interface on which the covering prefix is
+ * configured. Maybe this is a case for unnumbered.
*/
if (!arp_unnumbered (p0, sw_if_index0, conn_sw_if_index0))
{
@@ -636,8 +636,7 @@ arp_reply (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
goto drop;
}
- next0 = arp_mk_reply (vnm, p0, sw_if_index0,
- if_addr0, arp0, eth_rx);
+ next0 = arp_mk_reply (vnm, p0, sw_if_index0, if_addr0, arp0, eth_rx);
/* We are going to reply to this request, so, in the absence of
errors, learn the sender */
diff --git a/test/test_neighbor.py b/test/test_neighbor.py
index 7338eff86d3..6fcf13f8261 100644
--- a/test/test_neighbor.py
+++ b/test/test_neighbor.py
@@ -432,14 +432,24 @@ class ARPTestCase(VppTestCase):
self.assertEqual(unnum[0].ip_sw_if_index, self.pg1.sw_if_index)
self.assertEqual(unnum[0].sw_if_index, self.pg2.sw_if_index)
- #
- # We should respond to ARP requests for the unnumbered to address
- # once an attached route to the source is known
- #
- self.send_and_assert_no_replies(
- self.pg2, p, "ARP req for unnumbered address - no source"
+ # Allow for ARP requests from point-to-point ethernet neighbors
+ # without an attached route on pg2
+ self.pg2.add_stream(p)
+ self.pg_enable_capture(self.pg_interfaces)
+ self.pg_start()
+
+ rx = self.pg2.get_capture(1)
+ self.verify_arp_resp(
+ rx[0],
+ self.pg2.local_mac,
+ self.pg2.remote_mac,
+ self.pg1.local_ip4,
+ self.pg2.remote_hosts[3].ip4,
)
+ #
+ # Allow for ARP requests from neighbors on unnumbered with
+ # an attached route on pg2
attached_host = VppIpRoute(
self,
self.pg2.remote_hosts[3].ip4,