IP6 link-local table

- IPv6 link local table is a per-SW interface array of IPv6 unicast FIBs
- the per-interface ocst is sizeof(fib_table_t) which is small,
  w.r.t. the cost of an interface
- FE80::/10 in the 'global' table points to a DPO that performs a lookup in the
  input interface's LL fib.

Change-Id: Ice834b25ebeeacb2e929d7c864d7ec8c09918cbe
Signed-off-by: Neale Ranns <neale.ranns@cisco.com>

8 files changed, 106 insertions, 74 deletions

diff --git a/src/vnet/fib/fib_entry.h b/src/vnet/fib/fib_entry.h
index d905a839c48..3fde97add32 100644
--- a/src/vnet/fib/fib_entry.h
+++ b/src/vnet/fib/fib_entry.h
@@ -89,6 +89,10 @@ typedef enum fib_source_t_ {
      */
     FIB_SOURCE_IP6_ND_PROXY,
     /**
+     * IPv6 ND (seen in the link-local tables)
+     */
+    FIB_SOURCE_IP6_ND,
+    /**
      * Adjacency source.
      * routes created as a result of ARP/ND entries. This is lower priority
      * then the API/CLI. This is on purpose. trust me.
@@ -151,6 +155,7 @@ STATIC_ASSERT (sizeof(fib_source_t) == 1,
     [FIB_SOURCE_CLASSIFY] = "classify",			\
     [FIB_SOURCE_DHCP] = "DHCP",   			\
     [FIB_SOURCE_IP6_ND_PROXY] = "IPv6-proxy-nd",        \
+    [FIB_SOURCE_IP6_ND] = "IPv6-nd",                    \
     [FIB_SOURCE_RR] = "recursive-resolution",	        \
     [FIB_SOURCE_AE] = "attached_export",	        \
     [FIB_SOURCE_MPLS] = "mpls",           	        \
@@ -208,6 +213,10 @@ typedef enum fib_entry_attribute_t_ {
      */
     FIB_ENTRY_ATTRIBUTE_URPF_EXEMPT,
     /**
+     * The prefix/address exempted from attached export
+     */
+    FIB_ENTRY_ATTRIBUTE_NO_ATTACHED_EXPORT,
+    /**
      * This FIB entry imposes its source information on all prefixes
      * that is covers
      */
@@ -227,6 +236,7 @@ typedef enum fib_entry_attribute_t_ {
     [FIB_ENTRY_ATTRIBUTE_LOCAL]     = "local",		\
     [FIB_ENTRY_ATTRIBUTE_URPF_EXEMPT] = "uRPF-exempt",  \
     [FIB_ENTRY_ATTRIBUTE_MULTICAST] = "multicast",	\
+    [FIB_ENTRY_ATTRIBUTE_NO_ATTACHED_EXPORT] = "no-attached-export",	\
     [FIB_ENTRY_ATTRIBUTE_COVERED_INHERIT] = "covered-inherit",  \
 }
 
@@ -243,6 +253,7 @@ typedef enum fib_entry_flag_t_ {
     FIB_ENTRY_FLAG_EXCLUSIVE = (1 << FIB_ENTRY_ATTRIBUTE_EXCLUSIVE),
     FIB_ENTRY_FLAG_LOCAL     = (1 << FIB_ENTRY_ATTRIBUTE_LOCAL),
     FIB_ENTRY_FLAG_IMPORT    = (1 << FIB_ENTRY_ATTRIBUTE_IMPORT),
+    FIB_ENTRY_FLAG_NO_ATTACHED_EXPORT = (1 << FIB_ENTRY_ATTRIBUTE_NO_ATTACHED_EXPORT),
     FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT = (1 << FIB_ENTRY_ATTRIBUTE_URPF_EXEMPT),
     FIB_ENTRY_FLAG_MULTICAST = (1 << FIB_ENTRY_ATTRIBUTE_MULTICAST),
     FIB_ENTRY_FLAG_COVERED_INHERIT = (1 << FIB_ENTRY_ATTRIBUTE_COVERED_INHERIT),
diff --git a/src/vnet/fib/fib_entry_src.c b/src/vnet/fib/fib_entry_src.c
index 616d77e8b0a..6dc0c73a305 100644
--- a/src/vnet/fib/fib_entry_src.c
+++ b/src/vnet/fib/fib_entry_src.c
@@ -1352,10 +1352,7 @@ fib_route_attached_cross_table (const fib_entry_t *fib_entry,
 }
 
 /*
- * fib_route_attached_cross_table
- *
- * Return true the the route is attached via an interface that
- * is not in the same table as the route
+ * Return true if the path is attached
  */
 static inline int
 fib_path_is_attached (const fib_route_path_t *rpath)
@@ -1419,7 +1416,8 @@ fib_entry_flags_update (const fib_entry_t *fib_entry,
 	    esrc->fes_entry_flags |= FIB_ENTRY_FLAG_LOOSE_URPF_EXEMPT;
 	}
     }
-    if (fib_route_attached_cross_table(fib_entry, rpath))
+    if (fib_route_attached_cross_table(fib_entry, rpath) &&
+        !(esrc->fes_entry_flags & FIB_ENTRY_FLAG_NO_ATTACHED_EXPORT))
     {
 	esrc->fes_entry_flags |= FIB_ENTRY_FLAG_IMPORT;
     }
diff --git a/src/vnet/fib/fib_entry_src_api.c b/src/vnet/fib/fib_entry_src_api.c
index 1cdcfbde850..4558d65d523 100644
--- a/src/vnet/fib/fib_entry_src_api.c
+++ b/src/vnet/fib/fib_entry_src_api.c
@@ -167,5 +167,6 @@ fib_entry_src_api_register (void)
     fib_entry_src_register(FIB_SOURCE_CLI, &api_src_vft);
     fib_entry_src_register(FIB_SOURCE_DHCP, &api_src_vft);
     fib_entry_src_register(FIB_SOURCE_IP6_ND_PROXY, &api_src_vft);
+    fib_entry_src_register(FIB_SOURCE_IP6_ND, &api_src_vft);
     fib_entry_src_register(FIB_SOURCE_SR, &api_src_vft);
 }
diff --git a/src/vnet/fib/fib_entry_src_special.c b/src/vnet/fib/fib_entry_src_special.c
index a2899161c8f..c976da9327a 100644
--- a/src/vnet/fib/fib_entry_src_special.c
+++ b/src/vnet/fib/fib_entry_src_special.c
@@ -52,11 +52,22 @@ fib_entry_src_special_add (fib_entry_src_t *src,
 				     dpo);
 }
 
+static void
+fib_entry_src_special_path_swap (fib_entry_src_t *src,
+                                 const fib_entry_t *entry,
+                                 fib_path_list_flags_t pl_flags,
+                                 const fib_route_path_t *rpaths)
+{
+    src->fes_pl = fib_path_list_create((FIB_PATH_LIST_FLAG_SHARED | pl_flags),
+				       rpaths);
+}
+
 const static fib_entry_src_vft_t special_src_vft = {
     .fesv_init = fib_entry_src_special_init,
     .fesv_deinit = fib_entry_src_special_deinit,
     .fesv_add = fib_entry_src_special_add,
     .fesv_remove = fib_entry_src_special_remove,
+    .fesv_path_swap = fib_entry_src_special_path_swap,
 };
 
 void
diff --git a/src/vnet/fib/fib_table.c b/src/vnet/fib/fib_table.c
index c20bb255ddf..e9173484dec 100644
--- a/src/vnet/fib/fib_table.c
+++ b/src/vnet/fib/fib_table.c
@@ -1129,7 +1129,7 @@ fib_table_create_and_lock (fib_protocol_t proto,
 	fi = ip4_fib_table_create_and_lock(src);
         break;
     case FIB_PROTOCOL_IP6:
-	fi = ip6_fib_table_create_and_lock(src);
+	fi = ip6_fib_table_create_and_lock(src, FIB_TABLE_FLAG_NONE, NULL);
         break;
      case FIB_PROTOCOL_MPLS:
 	fi = mpls_fib_table_create_and_lock(src);
diff --git a/src/vnet/fib/fib_table.h b/src/vnet/fib/fib_table.h
index 14ac7054059..ddc00e537c2 100644
--- a/src/vnet/fib/fib_table.h
+++ b/src/vnet/fib/fib_table.h
@@ -29,6 +29,40 @@
 #define FIB_TABLE_TOTAL_LOCKS FIB_SOURCE_MAX
 
 /**
+ * Flags for the source data
+ */
+typedef enum fib_table_attribute_t_ {
+    /**
+     * Marker. Add new values after this one.
+     */
+    FIB_TABLE_ATTRIBUTE_FIRST,
+    /**
+     * the table is for IP6 link local addresses
+     */
+    FIB_TABLE_ATTRIBUTE_IP6_LL = FIB_TABLE_ATTRIBUTE_FIRST,
+    /**
+     * Marker. add new entries before this one.
+     */
+    FIB_TABLE_ATTRIBUTE_LAST = FIB_TABLE_ATTRIBUTE_IP6_LL,
+} fib_table_attribute_t;
+
+#define FIB_TABLE_ATTRIBUTE_MAX (FIB_TABLE_ATTRIBUTE_LAST+1)
+
+#define FIB_TABLE_ATTRIBUTES {		         \
+    [FIB_TABLE_ATTRIBUTE_IP6_LL]  = "ip6-ll",	 \
+}
+
+#define FOR_EACH_FIB_TABLE_ATTRIBUTE(_item)      	\
+    for (_item = FIB_TABLE_ATTRIBUTE_FIRST;		\
+	 _item < FIB_TABLE_ATTRIBUTE_MAX;		\
+	 _item++)
+
+typedef enum fib_table_flags_t_ {
+    FIB_TABLE_FLAG_NONE   = 0,
+    FIB_TABLE_FLAG_IP6_LL  = (1 << FIB_TABLE_ATTRIBUTE_IP6_LL),
+} __attribute__ ((packed)) fib_table_flags_t;
+
+/**
  * @brief 
  *   A protocol Independent FIB table
  */
@@ -40,6 +74,11 @@ typedef struct fib_table_t_
     fib_protocol_t ft_proto;
 
     /**
+     * Table flags
+     */
+    fib_table_flags_t ft_flags;
+
+    /**
      * per-source number of locks on the table
      */
     u16 ft_locks[FIB_TABLE_N_LOCKS];
diff --git a/src/vnet/fib/ip6_fib.c b/src/vnet/fib/ip6_fib.c
index 9f58e4b6a9e..fa9eb112986 100644
--- a/src/vnet/fib/ip6_fib.c
+++ b/src/vnet/fib/ip6_fib.c
@@ -15,6 +15,7 @@
 
 #include <vnet/fib/ip6_fib.h>
 #include <vnet/fib/fib_table.h>
+#include <vnet/dpo/ip6_ll_dpo.h>
 
 static void
 vnet_ip6_fib_init (u32 fib_index)
@@ -38,20 +39,23 @@ vnet_ip6_fib_init (u32 fib_index)
 				FIB_ENTRY_FLAG_DROP);
 
     /*
-     * all link local for us
+     * all link local via the link local lookup DPO
      */
     pfx.fp_addr.ip6.as_u64[0] = clib_host_to_net_u64 (0xFE80000000000000ULL);
     pfx.fp_addr.ip6.as_u64[1] = 0;
     pfx.fp_len = 10;
-    fib_table_entry_special_add(fib_index,
-				&pfx,
-				FIB_SOURCE_SPECIAL,
-				FIB_ENTRY_FLAG_LOCAL);
+    fib_table_entry_special_dpo_add(fib_index,
+                                    &pfx,
+                                    FIB_SOURCE_SPECIAL,
+                                    FIB_ENTRY_FLAG_NONE,
+                                    ip6_ll_dpo_get());
 }
 
 static u32
 create_fib_with_table_id (u32 table_id,
-                          fib_source_t src)
+                          fib_source_t src,
+                          fib_table_flags_t flags,
+                          u8 *desc)
 {
     fib_table_t *fib_table;
     ip6_fib_t *v6_fib;
@@ -76,6 +80,8 @@ create_fib_with_table_id (u32 table_id,
 	v6_fib->table_id =
 	    table_id;
     fib_table->ft_flow_hash_config = IP_FLOW_HASH_DEFAULT;
+    fib_table->ft_flags = flags;
+    fib_table->ft_desc = desc;
 
     vnet_ip6_fib_init(fib_table->ft_index);
     fib_table_lock(fib_table->ft_index, FIB_PROTOCOL_IP6, src);
@@ -91,95 +97,57 @@ ip6_fib_table_find_or_create_and_lock (u32 table_id,
 
     p = hash_get (ip6_main.fib_index_by_table_id, table_id);
     if (NULL == p)
-	return create_fib_with_table_id(table_id, src);
-    
+	return create_fib_with_table_id(table_id, src,
+                                        FIB_TABLE_FLAG_NONE,
+                                        NULL);
+
     fib_table_lock(p[0], FIB_PROTOCOL_IP6, src);
 
     return (p[0]);
 }
 
 u32
-ip6_fib_table_create_and_lock (fib_source_t src)
+ip6_fib_table_create_and_lock (fib_source_t src,
+                               fib_table_flags_t flags,
+                               u8 *desc)
 {
-    return (create_fib_with_table_id(~0, src));
+    return (create_fib_with_table_id(~0, src, flags, desc));
 }
 
 void
 ip6_fib_table_destroy (u32 fib_index)
 {
+    /*
+     * all link local first ...
+     */
     fib_prefix_t pfx = {
 	.fp_proto = FIB_PROTOCOL_IP6,
-	.fp_len = 0,
+	.fp_len = 10,
 	.fp_addr = {
 	    .ip6 = {
-		{ 0, 0, },
+                .as_u8 = {
+                    [0] = 0xFE,
+                    [1] = 0x80,
+                },
 	    },
 	}
     };
+    fib_table_entry_delete(fib_index,
+                           &pfx,
+                           FIB_SOURCE_SPECIAL);
 
     /*
-     * the default route.
+     * ... then the default route.
      */
+    pfx.fp_addr.ip6.as_u64[0] = 0;
+    pfx.fp_len = 00;
     fib_table_entry_special_remove(fib_index,
 				   &pfx,
 				   FIB_SOURCE_DEFAULT_ROUTE);
 
-
-    /*
-     * ff02::1:ff00:0/104
-     */
-    ip6_set_solicited_node_multicast_address(&pfx.fp_addr.ip6, 0);
-    pfx.fp_len = 104;
-    fib_table_entry_special_remove(fib_index,
-				   &pfx,
-				   FIB_SOURCE_SPECIAL);
-
-    /*
-     * all-routers multicast address
-     */
-    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
-					IP6_MULTICAST_SCOPE_link_local,
-					IP6_MULTICAST_GROUP_ID_all_routers);
-    pfx.fp_len = 128;
-    fib_table_entry_special_remove(fib_index,
-				   &pfx,
-				   FIB_SOURCE_SPECIAL);
-
-    /*
-     * all-nodes multicast address
-     */
-    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
-					IP6_MULTICAST_SCOPE_link_local,
-					IP6_MULTICAST_GROUP_ID_all_hosts);
-    pfx.fp_len = 128;
-    fib_table_entry_special_remove(fib_index,
-				   &pfx,
-				   FIB_SOURCE_SPECIAL);
-
-    /*
-     * all-mldv2 multicast address
-     */
-    ip6_set_reserved_multicast_address (&pfx.fp_addr.ip6,
-					IP6_MULTICAST_SCOPE_link_local,
-					IP6_MULTICAST_GROUP_ID_mldv2_routers);
-    pfx.fp_len = 128;
-    fib_table_entry_special_remove(fib_index,
-				   &pfx,
-				   FIB_SOURCE_SPECIAL);
-
-    /*
-     * all link local 
-     */
-    pfx.fp_addr.ip6.as_u64[0] = clib_host_to_net_u64 (0xFE80000000000000ULL);
-    pfx.fp_addr.ip6.as_u64[1] = 0;
-    pfx.fp_len = 10;
-    fib_table_entry_special_remove(fib_index,
-				   &pfx,
-				   FIB_SOURCE_SPECIAL);
-
     fib_table_t *fib_table = fib_table_get(fib_index, FIB_PROTOCOL_IP6);
     fib_source_t source;
-    
+
      /*
      * validate no more routes.
      */
@@ -691,6 +659,8 @@ ip6_show_fib (vlib_main_t * vm,
 	    continue;
 	if (fib_index != ~0 && fib_index != (int)fib->index)
 	    continue;
+        if (fib_table->ft_flags & FIB_TABLE_FLAG_IP6_LL)
+            continue;
 
 	s = format(s, "%U, fib_index:%d, flow hash:[%U] locks:[",
                    format_fib_table_name, fib->index,
diff --git a/src/vnet/fib/ip6_fib.h b/src/vnet/fib/ip6_fib.h
index dcd6c301bec..10ae75ce6f9 100644
--- a/src/vnet/fib/ip6_fib.h
+++ b/src/vnet/fib/ip6_fib.h
@@ -156,7 +156,9 @@ ip6_src_lookup_for_packet (ip6_main_t * im,
  */
 extern u32 ip6_fib_table_find_or_create_and_lock(u32 table_id,
                                                  fib_source_t src);
-extern u32 ip6_fib_table_create_and_lock(fib_source_t src);
+extern u32 ip6_fib_table_create_and_lock(fib_source_t src,
+                                         fib_table_flags_t flags,
+                                         u8* desc);
 
 extern u8 *format_ip6_fib_table_memory(u8 * s, va_list * args);