Fix DHCP client crash with worker threads

Crash occurring With a worker thread configured and dhcp
client active on an interface. When a DHCP reply packet
is received, call to ethernet_get_main() from
dhcp_proxy_to_client_input() was causing a crash.
Replaced with a call to vnet_get_ethernet_main().

Once that was resolved, calling dhcp_client_acquire_address()
from a worker thread also caused a crash. Changed so the main
thread will do the address/route configuration.

Change-Id: Ib23984787102dea8cf6cfcde86188a751f15c1e1
Signed-off-by: Matthew Smith <mgsmith@netgate.com>

3 files changed, 54 insertions, 38 deletions

diff --git a/src/vnet/dhcp/client.c b/src/vnet/dhcp/client.c
index e2cbc3281ca..f8f92a5d9f9 100644
--- a/src/vnet/dhcp/client.c
+++ b/src/vnet/dhcp/client.c
@@ -139,6 +139,56 @@ dhcp_client_proc_callback (uword * client_index)
 			     EVENT_DHCP_CLIENT_WAKEUP, *client_index);
 }
 
+static void
+dhcp_client_addr_callback (dhcp_client_t * c)
+{
+  dhcp_client_main_t *dcm = &dhcp_client_main;
+  void (*fp) (u32, u32, u8 *, u8, u8, u8 *, u8 *, u8 *) = c->event_callback;
+
+  /* replace the temporary RX address with the correct subnet */
+  dhcp_client_remove_rx_address (dcm, c);
+  dhcp_client_acquire_address (dcm, c);
+
+  /*
+   * Configure default IP route:
+   */
+  if (c->router_address.as_u32)
+    {
+      fib_prefix_t all_0s = {
+	.fp_len = 0,
+	.fp_addr.ip4.as_u32 = 0x0,
+	.fp_proto = FIB_PROTOCOL_IP4,
+      };
+      ip46_address_t nh = {
+	.ip4 = c->router_address,
+      };
+
+      /* *INDENT-OFF* */
+      fib_table_entry_path_add (
+	fib_table_get_index_for_sw_if_index (
+	  FIB_PROTOCOL_IP4,
+	  c->sw_if_index),
+	  &all_0s,
+	  FIB_SOURCE_DHCP,
+	  FIB_ENTRY_FLAG_NONE,
+          DPO_PROTO_IP4,
+          &nh, c->sw_if_index,
+          ~0, 1, NULL,	// no label stack
+          FIB_ROUTE_PATH_FLAG_NONE);
+      /* *INDENT-ON* */
+    }
+
+  /*
+   * Call the user's event callback to report DHCP information
+   */
+  if (fp)
+    (*fp) (c->client_index,	/* clinet index */
+	   c->pid, c->hostname, c->subnet_mask_width, 0,	/* is_ipv6 */
+	   (u8 *) & c->leased_address,	/* host IP address */
+	   (u8 *) & c->router_address,	/* router IP address */
+	   (u8 *) (c->l2_rewrite + 6));	/* host MAC address */
+}
+
 /*
  * dhcp_client_for_us - server-to-client callback.
  * Called from proxy_node.c:dhcp_proxy_to_client_input().
@@ -286,42 +336,8 @@ dhcp_client_for_us (u32 bi, vlib_buffer_t * b,
 	}
       /* OK, we own the address (etc), add to the routing table(s) */
       if (c->state == DHCP_REQUEST)
-	{
-	  void (*fp) (u32, u32, u8 *, u8, u8, u8 *, u8 *, u8 *) =
-	    c->event_callback;
-
-	  /* replace the temporary RX address with the correct subnet */
-	  dhcp_client_remove_rx_address (dcm, c);
-	  dhcp_client_acquire_address (dcm, c);
-
-	  /*
-	   * Configure default IP route:
-	   */
-	  if (c->router_address.as_u32)
-	    {
-	      fib_prefix_t all_0s = {
-		.fp_len = 0,
-		.fp_addr.ip4.as_u32 = 0x0,
-		.fp_proto = FIB_PROTOCOL_IP4,
-	      };
-	      ip46_address_t nh = {
-		.ip4 = c->router_address,
-	      };
-
-	      fib_table_entry_path_add (fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, c->sw_if_index), &all_0s, FIB_SOURCE_DHCP, FIB_ENTRY_FLAG_NONE, DPO_PROTO_IP4, &nh, c->sw_if_index, ~0, 1, NULL,	// no label stack
-					FIB_ROUTE_PATH_FLAG_NONE);
-	    }
-
-	  /*
-	   * Call the user's event callback to report DHCP information
-	   */
-	  if (fp)
-	    (*fp) (c->client_index,	/* clinet index */
-		   c->pid, c->hostname, c->subnet_mask_width, 0,	/* is_ipv6 */
-		   (u8 *) & c->leased_address,	/* host IP address */
-		   (u8 *) & c->router_address,	/* router IP address */
-		   (u8 *) (c->l2_rewrite + 6));	/* host MAC address */
-	}
+	vl_api_rpc_call_main_thread (dhcp_client_addr_callback,
+				     (u8 *) c, sizeof (*c));
 
       c->state = DHCP_BOUND;
       c->retry_count = 0;
diff --git a/src/vnet/dhcp/dhcp4_proxy_node.c b/src/vnet/dhcp/dhcp4_proxy_node.c
index e84d72c0afb..6b15c51b38f 100644
--- a/src/vnet/dhcp/dhcp4_proxy_node.c
+++ b/src/vnet/dhcp/dhcp4_proxy_node.c
@@ -477,7 +477,7 @@ dhcp_proxy_to_client_input (vlib_main_t * vm,
 			    vlib_frame_t * from_frame)
 {
   u32 n_left_from, *from;
-  ethernet_main_t *em = ethernet_get_main (vm);
+  ethernet_main_t *em = vnet_get_ethernet_main ();
   dhcp_proxy_main_t *dpm = &dhcp_proxy_main;
   vnet_main_t *vnm = vnet_get_main ();
   ip4_main_t *im = &ip4_main;
diff --git a/src/vnet/dhcp/dhcp6_proxy_node.c b/src/vnet/dhcp/dhcp6_proxy_node.c
index 5a3a99e2e5d..2a1ac12e535 100644
--- a/src/vnet/dhcp/dhcp6_proxy_node.c
+++ b/src/vnet/dhcp/dhcp6_proxy_node.c
@@ -563,7 +563,7 @@ dhcpv6_proxy_to_client_input (vlib_main_t * vm,
 {
 
   u32 n_left_from, *from;
-  ethernet_main_t *em = ethernet_get_main (vm);
+  ethernet_main_t *em = vnet_get_ethernet_main ();
   dhcp_proxy_main_t *dm = &dhcp_proxy_main;
   dhcp_proxy_t *proxy;
   dhcp_server_t *server;