dhcp: fix crash on unicast renewal send

Type: fix

- when the addresses were learnt a copy of the client was sent to the
main thread, this meant the unicast adjacecny was saved on the copy
not on the original.
- Add logging.
- Improve the proxy-node that hands the clint packets so the DHCP
packets are traced.
 - allow a renewal to configure new address data

Change-Id: I6ab0afcccbc4a1cdefdd1b8beeda8fc7ba20ec1f
Signed-off-by: Neale Ranns <nranns@cisco.com>

src/plugins/dhcp/client.h

@@ -42,6 +42,24 @@ struct dhcp_client_t_;
 typedef void (*dhcp_event_cb_t) (u32 client_index,
 				 const struct dhcp_client_t_ * client);
 
+/**
+ * The set of addresses/mask that contribute forwarding info
+ * and are installed.
+ */
+typedef struct dhcp_client_fwd_addresses_t_
+{
+  /** the address assigned to this client and it's mask */
+  ip4_address_t leased_address;
+  u32 subnet_mask_width;
+
+  /** the address of the DHCP server handing out the address.
+      this is used to send any unicast messages */
+  ip4_address_t dhcp_server;
+
+  /** The address of this client's default gateway - may not be present */
+  ip4_address_t router_address;
+} dhcp_client_fwd_addresses_t;
+
 typedef struct dhcp_client_t_
 {
   dhcp_client_state_t state;
@@ -59,11 +77,16 @@ typedef struct dhcp_client_t_
   /* DHCP transaction ID, a random number */
   u32 transaction_id;
 
-  /* leased address, other learned info DHCP */
-  ip4_address_t leased_address;	/* from your_ip_address field */
-  ip4_address_t dhcp_server;
-  u32 subnet_mask_width;	/* option 1 */
-  ip4_address_t router_address;	/* option 3 */
+  /**
+   * leased address, other learned info DHCP
+   *  the learned set is updated by new messages recieved in the DP
+   *  the installed set is what's actually been added
+   */
+  dhcp_client_fwd_addresses_t learned;
+  dhcp_client_fwd_addresses_t installed;
+  /* have local Addresses and default route been installed */
+  u8 addresses_installed;
+
   ip4_address_t *domain_server_address;	/* option 6 */
   u32 lease_renewal_interval;	/* option 51 */
   u32 lease_lifetime;		/* option 59 */