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authorDave Barach <dave@barachs.net>2018-05-26 10:48:55 -0400
committerOle Trøan <otroan@employees.org>2018-05-27 04:39:56 +0000
commit525c9d0f8645ef9901316f042c195adc970b4546 (patch)
tree88486d59b7c9ec37bae5e8434dbd7508a1e3c92e /src/vnet/dhcp/client.c
parentfc23f12c252a9843aeeb8dae7bf60264908f084d (diff)
VPP-1294: add missing feature arc constraint
the ip4-dhcp-client-detect feature MUST run prior to nat44-out2in, or inbound dhcp broadcast packets will be dropped. Certain dhcp servers answer lease renewal dhcp-request packets with broadcast dhcp-acks, leading to unrecoverable lease loss. In detail, this constraint: VNET_FEATURE_INIT (ip4_snat_out2in, static) = { .arc_name = "ip4-unicast", .node_name = "nat44-out2in", .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa"), }; doesn't get the job done: ip4-unicast: [17] nat44-out2in [23] ip4-dhcp-client-detect [26] ip4-not-enabled Add a proper constraint: VNET_FEATURE_INIT (ip4_snat_out2in, static) = { .arc_name = "ip4-unicast", .node_name = "nat44-out2in", .runs_after = VNET_FEATURES ("acl-plugin-in-ip4-fa", "ip4-dhcp-client-detect"), }; and the interface feature order is OK, at least in this regard: ip4-unicast: [17] ip4-dhcp-client-detect [18] nat44-out2in [26] ip4-not-enabled We need to carefully audit (especially) the ip4-unicast feature arc, which has [gasp] 37 features on it! Change-Id: I5e749ead7ab2a25d80839a331de6261e112977ad Signed-off-by: Dave Barach <dave@barachs.net>
Diffstat (limited to 'src/vnet/dhcp/client.c')
-rw-r--r--src/vnet/dhcp/client.c24
1 files changed, 20 insertions, 4 deletions
diff --git a/src/vnet/dhcp/client.c b/src/vnet/dhcp/client.c
index dbcb2a53dbc..11e47f9ad7a 100644
--- a/src/vnet/dhcp/client.c
+++ b/src/vnet/dhcp/client.c
@@ -106,6 +106,7 @@ dhcp_client_addr_callback (dhcp_client_t * c)
vnet_feature_enable_disable ("ip4-unicast",
"ip4-dhcp-client-detect",
c->sw_if_index, 0 /* disable */ , 0, 0);
+ c->client_detect_feature_enabled = 0;
/* if renewing the lease, the address and route have already been added */
if (c->state == DHCP_BOUND)
@@ -220,6 +221,7 @@ dhcp_client_for_us (u32 bi, vlib_buffer_t * b,
{
u32 lease_time_in_seconds =
clib_host_to_net_u32 (o->data_as_u32[0]);
+ // for debug: lease_time_in_seconds = 20; /*$$$$*/
c->lease_expires = now + (f64) lease_time_in_seconds;
c->lease_lifetime = lease_time_in_seconds;
/* Set a sensible default, in case we don't get opt 58 */
@@ -307,6 +309,7 @@ dhcp_client_for_us (u32 bi, vlib_buffer_t * b,
"ip4-dhcp-client-detect",
c->sw_if_index, 1 /* enable */ ,
0, 0);
+ c->client_detect_feature_enabled = 1;
}
/* Wipe out any memory of the address we had... */
c->state = DHCP_DISCOVER;
@@ -577,6 +580,15 @@ dhcp_discover_state (dhcp_client_main_t * dcm, dhcp_client_t * c, f64 now)
* State machine "DISCOVER" state. Send a dhcp discover packet,
* eventually back off the retry rate.
*/
+
+ if (c->client_detect_feature_enabled == 0)
+ {
+ vnet_feature_enable_disable ("ip4-unicast",
+ "ip4-dhcp-client-detect",
+ c->sw_if_index, 1 /* enable */ , 0, 0);
+ c->client_detect_feature_enabled = 1;
+ }
+
send_dhcp_pkt (dcm, c, DHCP_PACKET_DISCOVER, 1 /* is_broadcast */ );
c->retry_count++;
@@ -623,10 +635,13 @@ dhcp_bound_state (dhcp_client_main_t * dcm, dhcp_client_t * c, f64 now)
* DHCP address. Turn it back on again on first renew attempt.
* Otherwise, if the DHCP server replies we'll never see it.
*/
- if (!c->retry_count)
- vnet_feature_enable_disable ("ip4-unicast",
- "ip4-dhcp-client-detect",
- c->sw_if_index, 1 /* enable */ , 0, 0);
+ if (c->client_detect_feature_enabled == 0)
+ {
+ vnet_feature_enable_disable ("ip4-unicast",
+ "ip4-dhcp-client-detect",
+ c->sw_if_index, 1 /* enable */ , 0, 0);
+ c->client_detect_feature_enabled = 1;
+ }
send_dhcp_pkt (dcm, c, DHCP_PACKET_REQUEST, 0 /* is_broadcast */ );
@@ -928,6 +943,7 @@ dhcp_client_add_del (dhcp_client_add_del_args_t * a)
vnet_feature_enable_disable ("ip4-unicast",
"ip4-dhcp-client-detect",
c->sw_if_index, 1 /* enable */ , 0, 0);
+ c->client_detect_feature_enabled = 1;
vlib_process_signal_event (vm, dhcp_client_process_node.index,
EVENT_DHCP_CLIENT_WAKEUP, c - dcm->clients);