Allow the provider of a midchain adjacency to pass context data that is returned in the fixup function

Change-Id: I458e6e03b03e27775df33a2fd302743126d6ac44
Signed-off-by: Neale Ranns <nranns@cisco.com>

15 files changed, 88 insertions, 30 deletions

diff --git a/src/plugins/pppoe/pppoe.c b/src/plugins/pppoe/pppoe.c
index fac29c781fa..dfbe2e487c9 100644
--- a/src/plugins/pppoe/pppoe.c
+++ b/src/plugins/pppoe/pppoe.c
@@ -146,16 +146,23 @@ pppoe_build_rewrite (vnet_main_t * vnm,
  * @brief Fixup the adj rewrite post encap. Insert the packet's length
  */
 static void
-pppoe_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0)
+pppoe_fixup (vlib_main_t * vm,
+	     ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
 {
+  const pppoe_session_t *t;
   pppoe_header_t *pppoe0;
 
+  /* update the rewrite string */
   pppoe0 = vlib_buffer_get_current (b0) + sizeof (ethernet_header_t);
 
   pppoe0->length = clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0)
 					 - sizeof (pppoe_header_t)
 					 + sizeof (pppoe0->ppp_proto)
 					 - sizeof (ethernet_header_t));
+  /* Swap to the the packet's output interface to the encap (not the
+   * session) interface */
+  t = data;
+  vnet_buffer (b0)->sw_if_index[VLIB_TX] = t->encap_if_index;
 }
 
 static void
@@ -170,12 +177,14 @@ pppoe_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
   ASSERT (ADJ_INDEX_INVALID != ai);
 
   adj = adj_get (ai);
+  session_id = pem->session_index_by_sw_if_index[sw_if_index];
+  t = pool_elt_at_index (pem->sessions, session_id);
 
   switch (adj->lookup_next_index)
     {
     case IP_LOOKUP_NEXT_ARP:
     case IP_LOOKUP_NEXT_GLEAN:
-      adj_nbr_midchain_update_rewrite (ai, pppoe_fixup,
+      adj_nbr_midchain_update_rewrite (ai, pppoe_fixup, t,
 				       ADJ_FLAG_NONE,
 				       pppoe_build_rewrite (vnm,
 							    sw_if_index,
@@ -187,7 +196,7 @@ pppoe_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
        * Construct a partial rewrite from the known ethernet mcast dest MAC
        * There's no MAC fixup, so the last 2 parameters are 0
        */
-      adj_mcast_midchain_update_rewrite (ai, pppoe_fixup,
+      adj_mcast_midchain_update_rewrite (ai, pppoe_fixup, t,
 					 ADJ_FLAG_NONE,
 					 pppoe_build_rewrite (vnm,
 							      sw_if_index,
@@ -207,8 +216,6 @@ pppoe_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
       break;
     }
 
-  session_id = pem->session_index_by_sw_if_index[sw_if_index];
-  t = pool_elt_at_index (pem->sessions, session_id);
   interface_tx_dpo_add_or_lock (vnet_link_to_dpo_proto (adj->ia_link),
 				t->encap_if_index, &dpo);
 
diff --git a/src/vnet/adj/adj.h b/src/vnet/adj/adj.h
index ed5eb1f1e88..fe77d1634e0 100644
--- a/src/vnet/adj/adj.h
+++ b/src/vnet/adj/adj.h
@@ -141,7 +141,8 @@ struct ip_adjacency_t_;
  */
 typedef void (*adj_midchain_fixup_t) (vlib_main_t * vm,
 				      struct ip_adjacency_t_ * adj,
-				      vlib_buffer_t * b0);
+				      vlib_buffer_t * b0,
+                                      const void *data);
 
 /**
  * @brief Flags on an IP adjacency
@@ -242,6 +243,10 @@ typedef struct ip_adjacency_t_
        * A function to perform the post-rewrite fixup
        */
       adj_midchain_fixup_t fixup_func;
+      /**
+       * Fixup data passed back to the client in the fixup function
+       */
+      const void *fixup_data;
     } midchain;
     /**
      * IP_LOOKUP_NEXT_GLEAN
diff --git a/src/vnet/adj/adj_internal.h b/src/vnet/adj/adj_internal.h
index ca41cb21d9e..e6d276e4d02 100644
--- a/src/vnet/adj/adj_internal.h
+++ b/src/vnet/adj/adj_internal.h
@@ -95,6 +95,7 @@ extern void adj_nbr_update_rewrite_internal(ip_adjacency_t *adj,
                                             u8 *rewrite);
 extern void adj_midchain_setup(adj_index_t adj_index,
                                adj_midchain_fixup_t fixup,
+                               const void *data,
                                adj_flags_t flags);
 
 extern ip_adjacency_t * adj_alloc(fib_protocol_t proto);
diff --git a/src/vnet/adj/adj_l2.c b/src/vnet/adj/adj_l2.c
index 20d70dd4cd1..132ceb28168 100644
--- a/src/vnet/adj/adj_l2.c
+++ b/src/vnet/adj/adj_l2.c
@@ -110,7 +110,9 @@ adj_l2_rewrite_inline (vlib_main_t * vm,
 
 		if (is_midchain)
 		{
-		    adj0->sub_type.midchain.fixup_func(vm, adj0, p0);
+		    adj0->sub_type.midchain.fixup_func(
+                        vm, adj0, p0,
+                        adj0->sub_type.midchain.fixup_data);
 		}
 
 		vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
diff --git a/src/vnet/adj/adj_mcast.c b/src/vnet/adj/adj_mcast.c
index 00a12ad330b..efc781de989 100644
--- a/src/vnet/adj/adj_mcast.c
+++ b/src/vnet/adj/adj_mcast.c
@@ -139,6 +139,7 @@ adj_mcast_update_rewrite (adj_index_t adj_index,
 void
 adj_mcast_midchain_update_rewrite (adj_index_t adj_index,
                                    adj_midchain_fixup_t fixup,
+                                   const void *fixup_data,
                                    adj_flags_t flags,
                                    u8 *rewrite,
                                    u8 offset,
@@ -160,7 +161,7 @@ adj_mcast_midchain_update_rewrite (adj_index_t adj_index,
      */
     ASSERT(NULL != rewrite);
 
-    adj_midchain_setup(adj_index, fixup, flags);
+    adj_midchain_setup(adj_index, fixup, fixup_data, flags);
 
     /*
      * update the adj's rewrite string and build the arc
@@ -354,14 +355,13 @@ format_adj_mcast_midchain (u8* s, va_list *ap)
 {
     index_t index = va_arg(*ap, index_t);
     CLIB_UNUSED(u32 indent) = va_arg(*ap, u32);
-    vnet_main_t * vnm = vnet_get_main();
     ip_adjacency_t * adj = adj_get(index);
 
     s = format(s, "%U-mcast-midchain: ",
                format_fib_protocol, adj->ia_nh_proto);
     s = format (s, "%U",
 		format_vnet_rewrite,
-		vnm->vlib_main, &adj->rewrite_header,
+		&adj->rewrite_header,
                 sizeof (adj->rewrite_data), 0);
     s = format (s, "\n%Ustacked-on:\n%U%U",
 		format_white_space, indent,
diff --git a/src/vnet/adj/adj_mcast.h b/src/vnet/adj/adj_mcast.h
index bfb0d6f6d11..55e2ec03d09 100644
--- a/src/vnet/adj/adj_mcast.h
+++ b/src/vnet/adj/adj_mcast.h
@@ -77,11 +77,22 @@ extern void adj_mcast_update_rewrite(adj_index_t adj_index,
  * @param
  *  The index of the adj to update
  *
+ * @param fixup
+ *  The function that will be invoked at paket switch time to 'fixup'
+ *  the rewrite applied with necessary per-packet info (i.e. length, checksums).
+ * @param fixup_data
+ *  Context data set by the caller that is provided as an argument in the
+ *  fixup function.
+ *
+ * @param flags
+ *  Flags controlling the adjacency behaviour
+ *
  * @param
  *  The new rewrite
  */
 extern void adj_mcast_midchain_update_rewrite(adj_index_t adj_index,
                                               adj_midchain_fixup_t fixup,
+                                              const void *fixup_data,
                                               adj_flags_t flags,
                                               u8 *rewrite,
                                               u8 offset,
diff --git a/src/vnet/adj/adj_midchain.c b/src/vnet/adj/adj_midchain.c
index 370fa4652f8..9fd3246b15a 100644
--- a/src/vnet/adj/adj_midchain.c
+++ b/src/vnet/adj/adj_midchain.c
@@ -460,6 +460,7 @@ adj_nbr_midchain_get_feature_node (ip_adjacency_t *adj)
 void
 adj_midchain_setup (adj_index_t adj_index,
                     adj_midchain_fixup_t fixup,
+                    const void *data,
                     adj_flags_t flags)
 {
     u32 feature_index, tx_node;
@@ -471,6 +472,7 @@ adj_midchain_setup (adj_index_t adj_index,
     adj = adj_get(adj_index);
 
     adj->sub_type.midchain.fixup_func = fixup;
+    adj->sub_type.midchain.fixup_data = data;
     adj->ia_flags |= flags;
 
     arc_index = adj_midchain_get_feature_arc_index_for_link_type (adj);
@@ -503,6 +505,7 @@ adj_midchain_setup (adj_index_t adj_index,
 void
 adj_nbr_midchain_update_rewrite (adj_index_t adj_index,
 				 adj_midchain_fixup_t fixup,
+                                 const void *fixup_data,
 				 adj_flags_t flags,
 				 u8 *rewrite)
 {
@@ -522,7 +525,7 @@ adj_nbr_midchain_update_rewrite (adj_index_t adj_index,
      */
     ASSERT(NULL != rewrite);
 
-    adj_midchain_setup(adj_index, fixup, flags);
+    adj_midchain_setup(adj_index, fixup, fixup_data, flags);
 
     /*
      * update the rewirte with the workers paused.
diff --git a/src/vnet/adj/adj_midchain.h b/src/vnet/adj/adj_midchain.h
index 27ca1d3398d..65892314f40 100644
--- a/src/vnet/adj/adj_midchain.h
+++ b/src/vnet/adj/adj_midchain.h
@@ -31,15 +31,22 @@
  * @param adj_index
  *  The index of the neighbour adjacency.
  *
- * @param post_rewrite_node
- *  The VLIB graph node that provides the post-encap fixup.
- *  where 'fixup' is e.g., correcting chksum, length, etc.
+ * @param fixup
+ *  The function that will be invoked at paket switch time to 'fixup'
+ *  the rewrite applied with necessary per-packet info (i.e. length, checksums).
+ * @param fixup_data
+ *  Context data set by the caller that is provided as an argument in the
+ *  fixup function.
+ *
+ * @param flags
+ *  Flags controlling the adjacency behaviour
  *
  * @param rewrite
  *  The rewrite.
  */
 extern void adj_nbr_midchain_update_rewrite(adj_index_t adj_index,
 					    adj_midchain_fixup_t fixup,
+                                            const void *fixup_data,
 					    adj_flags_t flags,
 					    u8 *rewrite);
 
diff --git a/src/vnet/adj/adj_nsh.c b/src/vnet/adj/adj_nsh.c
index 128570b02a9..76503f59309 100644
--- a/src/vnet/adj/adj_nsh.c
+++ b/src/vnet/adj/adj_nsh.c
@@ -111,7 +111,9 @@ adj_nsh_rewrite_inline (vlib_main_t * vm,
 
                 if (is_midchain)
                 {
-                    adj0->sub_type.midchain.fixup_func(vm, adj0, p0);
+                    adj0->sub_type.midchain.fixup_func(
+                        vm, adj0, p0,
+                        adj0->sub_type.midchain.fixup_data);
                 }
 
                 vnet_buffer (p0)->sw_if_index[VLIB_TX] = tx_sw_if_index0;
diff --git a/src/vnet/gre/gre.c b/src/vnet/gre/gre.c
index 7660bbe1d4b..c049b87b6a7 100644
--- a/src/vnet/gre/gre.c
+++ b/src/vnet/gre/gre.c
@@ -261,8 +261,9 @@ gre_build_rewrite (vnet_main_t * vnm,
 
 #define is_v4_packet(_h) ((*(u8*) _h) & 0xF0) == 0x40
 
-void
-gre4_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0)
+static void
+gre4_fixup (vlib_main_t * vm,
+	    ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
 {
   ip4_header_t *ip0;
 
@@ -274,8 +275,9 @@ gre4_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0)
   ip0->checksum = ip4_header_checksum (ip0);
 }
 
-void
-gre6_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b0)
+static void
+gre6_fixup (vlib_main_t * vm,
+	    ip_adjacency_t * adj, vlib_buffer_t * b0, const void *data)
 {
   ip6_header_t *ip0;
 
@@ -301,6 +303,7 @@ gre_update_adj (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
   is_ipv6 = t->tunnel_dst.fp_proto == FIB_PROTOCOL_IP6 ? 1 : 0;
 
   adj_nbr_midchain_update_rewrite (ai, !is_ipv6 ? gre4_fixup : gre6_fixup,
+				   NULL,
 				   (VNET_LINK_ETHERNET ==
 				    adj_get_link_type (ai) ?
 				    ADJ_FLAG_MIDCHAIN_NO_COUNT :
diff --git a/src/vnet/ip/ip4_forward.c b/src/vnet/ip/ip4_forward.c
index 201d391a77e..c4c54b7ab22 100755
--- a/src/vnet/ip/ip4_forward.c
+++ b/src/vnet/ip/ip4_forward.c
@@ -2541,8 +2541,10 @@ ip4_rewrite_inline (vlib_main_t * vm,
 
 	  if (is_midchain)
 	    {
-	      adj0->sub_type.midchain.fixup_func (vm, adj0, p0);
-	      adj1->sub_type.midchain.fixup_func (vm, adj1, p1);
+	      adj0->sub_type.midchain.fixup_func
+		(vm, adj0, p0, adj0->sub_type.midchain.fixup_data);
+	      adj1->sub_type.midchain.fixup_func
+		(vm, adj1, p1, adj0->sub_type.midchain.fixup_data);
 	    }
 	  if (is_mcast)
 	    {
@@ -2667,7 +2669,8 @@ ip4_rewrite_inline (vlib_main_t * vm,
 
 	      if (is_midchain)
 		{
-		  adj0->sub_type.midchain.fixup_func (vm, adj0, p0);
+		  adj0->sub_type.midchain.fixup_func
+		    (vm, adj0, p0, adj0->sub_type.midchain.fixup_data);
 		}
 
 	      if (PREDICT_FALSE
diff --git a/src/vnet/ip/ip6_forward.c b/src/vnet/ip/ip6_forward.c
index a7e7930a69f..0a308720389 100644
--- a/src/vnet/ip/ip6_forward.c
+++ b/src/vnet/ip/ip6_forward.c
@@ -2229,8 +2229,10 @@ ip6_rewrite_inline (vlib_main_t * vm,
 
 	  if (is_midchain)
 	    {
-	      adj0->sub_type.midchain.fixup_func (vm, adj0, p0);
-	      adj1->sub_type.midchain.fixup_func (vm, adj1, p1);
+	      adj0->sub_type.midchain.fixup_func
+		(vm, adj0, p0, adj0->sub_type.midchain.fixup_data);
+	      adj1->sub_type.midchain.fixup_func
+		(vm, adj1, p1, adj1->sub_type.midchain.fixup_data);
 	    }
 	  if (is_mcast)
 	    {
@@ -2340,7 +2342,8 @@ ip6_rewrite_inline (vlib_main_t * vm,
 
 	  if (is_midchain)
 	    {
-	      adj0->sub_type.midchain.fixup_func (vm, adj0, p0);
+	      adj0->sub_type.midchain.fixup_func
+		(vm, adj0, p0, adj0->sub_type.midchain.fixup_data);
 	    }
 	  if (is_mcast)
 	    {
diff --git a/src/vnet/lisp-gpe/lisp_gpe_adjacency.c b/src/vnet/lisp-gpe/lisp_gpe_adjacency.c
index 7db1c9bbb72..7464af3d441 100644
--- a/src/vnet/lisp-gpe/lisp_gpe_adjacency.c
+++ b/src/vnet/lisp-gpe/lisp_gpe_adjacency.c
@@ -307,7 +307,8 @@ lisp_gpe_increment_stats_counters (lisp_cp_main_t * lcm, ip_adjacency_t * adj,
 }
 
 static void
-lisp_gpe_fixup (vlib_main_t * vm, ip_adjacency_t * adj, vlib_buffer_t * b)
+lisp_gpe_fixup (vlib_main_t * vm,
+		ip_adjacency_t * adj, vlib_buffer_t * b, const void *data)
 {
   lisp_cp_main_t *lcm = vnet_lisp_cp_get_main ();
 
@@ -348,6 +349,7 @@ lisp_gpe_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, adj_index_t ai)
   linkt = adj_get_link_type (ai);
   adj_nbr_midchain_update_rewrite
     (ai, lisp_gpe_fixup,
+     NULL,
      (VNET_LINK_ETHERNET == linkt ?
       ADJ_FLAG_MIDCHAIN_NO_COUNT :
       ADJ_FLAG_NONE),
diff --git a/src/vnet/mpls/mpls_output.c b/src/vnet/mpls/mpls_output.c
index 0dc12b8d5bd..22e6c1062c3 100644
--- a/src/vnet/mpls/mpls_output.c
+++ b/src/vnet/mpls/mpls_output.c
@@ -185,8 +185,12 @@ mpls_output_inline (vlib_main_t * vm,
             }
           if (is_midchain)
           {
-              adj0->sub_type.midchain.fixup_func(vm, adj0, p0);
-              adj1->sub_type.midchain.fixup_func(vm, adj1, p1);
+	      adj0->sub_type.midchain.fixup_func
+                (vm, adj0, p0,
+                 adj0->sub_type.midchain.fixup_data);
+	      adj1->sub_type.midchain.fixup_func
+                (vm, adj1, p1,
+                 adj1->sub_type.midchain.fixup_data);
           }
 
           p0->error = error_node->errors[error0];
@@ -266,7 +270,9 @@ mpls_output_inline (vlib_main_t * vm,
             }
           if (is_midchain)
           {
-              adj0->sub_type.midchain.fixup_func(vm, adj0, p0);
+	      adj0->sub_type.midchain.fixup_func
+                (vm, adj0, p0,
+                 adj0->sub_type.midchain.fixup_data);
           }
 
           p0->error = error_node->errors[error0];
diff --git a/src/vnet/mpls/mpls_tunnel.c b/src/vnet/mpls/mpls_tunnel.c
index efd9e2dbc84..8ed2c409ce8 100644
--- a/src/vnet/mpls/mpls_tunnel.c
+++ b/src/vnet/mpls/mpls_tunnel.c
@@ -377,7 +377,8 @@ mpls_tunnel_admin_up_down (vnet_main_t * vnm,
 static void
 mpls_tunnel_fixup (vlib_main_t *vm,
                    ip_adjacency_t *adj,
-                   vlib_buffer_t *b0)
+                   vlib_buffer_t *b0,
+                   const void*data)
 {
     /*
      * A no-op w.r.t. the header. but reset the 'have we pushed any
@@ -403,6 +404,7 @@ mpls_tunnel_update_adj (vnet_main_t * vnm,
     case IP_LOOKUP_NEXT_ARP:
     case IP_LOOKUP_NEXT_GLEAN:
         adj_nbr_midchain_update_rewrite(ai, mpls_tunnel_fixup,
+                                        NULL,
                                         ADJ_FLAG_NONE,
                                         mpls_tunnel_build_rewrite_i());
         break;
@@ -412,6 +414,7 @@ mpls_tunnel_update_adj (vnet_main_t * vnm,
          * There's no MAC fixup, so the last 2 parameters are 0
          */
         adj_mcast_midchain_update_rewrite(ai, mpls_tunnel_fixup,
+                                          NULL,
                                           ADJ_FLAG_NONE,
                                           mpls_tunnel_build_rewrite_i(),
                                           0, 0);