xia: add fxid_copy to FIB interface

Since the underlying structure of a FIB entry is not known to
the principal, it cannot copy a FIB entry. This patch adds a
function to every FIB that makes a copy of a FIB entry that
includes FIB-specific data.

This patch also fixes a bug in the LPM principal by making use
of the new copy function.

Author: cjdoucette

include/net/xia_fib.h

@@ -194,6 +194,16 @@ struct xia_ppal_rt_iops {
 	 */
 	void (*fxid_init)(struct fib_xid *fxid, int table_id, int entry_type);
 
+	/* fxid_copy - copy @old_fxid, including FIB-specific data.
+	 *
+	 * NOTE
+	 *	This function must copy any FIB-specific data in addition
+	 *	to the fields from struct fib_xid. @old_fxid and @new_fxid
+	 *	should reference FIB entries previously allocated by
+	 *	fxid_ppal_alloc().
+	 */
+	void (*fxid_copy)(struct fib_xid *old_fxid, struct fib_xid *new_fxid);
+
 	/** fxid_find_rcu - Find struct fib_xid in @xtbl that has key @xid.
 	 *
 	 * RETURN

net/xia/list_fib.c

@@ -171,6 +171,12 @@ static void list_fxid_init(struct fib_xid *fxid, int table_id, int entry_type)
 	fxid->dead.xtbl = NULL;
 }
 
+static void list_fxid_copy(struct fib_xid *old_fxid, struct fib_xid *new_fxid)
+{
+	memcpy(new_fxid, old_fxid,
+		sizeof(*old_fxid) + sizeof(struct list_fib_xid));
+}
+
 static void list_xtbl_death_work(struct work_struct *work)
 {
 	struct fib_xid_table *xtbl = container_of(work, struct fib_xid_table,
@@ -621,6 +627,7 @@ const struct xia_ppal_rt_iops xia_ppal_list_rt_iops = {
 
 	.fxid_ppal_alloc = list_fxid_ppal_alloc,
 	.fxid_init = list_fxid_init,
+	.fxid_copy = list_fxid_copy,
 
 	.fxid_find_rcu = list_fxid_find_rcu,
 	.fxid_find_lock = list_fxid_find_lock,

net/xia/ppal_lpm/main.c

@@ -105,6 +105,7 @@ static int newroute_flush_anchor_unlock(struct fib_xid_table *xtbl,
 		 * node with the new one in the tree.
 		 */
 		xdst_init_anchor(&dup_llpm->anchor);
+		lpm_rt_iops->fxid_copy(&dup_llpm->common, pred_fxid);
 		lpm_rt_iops->fxid_replace_locked(xtbl, pred_fxid,
 						 &dup_llpm->common);
 
@@ -136,6 +137,7 @@ static int newroute_flush_anchor_unlock(struct fib_xid_table *xtbl,
 		}
 
 		dup_mrd->gw = fxid_mrd(pred_fxid)->gw;
+		lpm_rt_iops->fxid_copy(&dup_mrd->common, pred_fxid);
 		lpm_rt_iops->fxid_replace_locked(xtbl, pred_fxid,
 						 &dup_mrd->common);
 

net/xia/ppal_lpm/tree_fib.c

@@ -109,6 +109,12 @@ static void tree_fxid_init(struct fib_xid *fxid, int table_id, int entry_type)
 	fxid->dead.xtbl = NULL;
 }
 
+static void tree_fxid_copy(struct fib_xid *old_fxid, struct fib_xid *new_fxid)
+{
+	memcpy(new_fxid, old_fxid,
+		sizeof(*old_fxid) + sizeof(struct tree_fib_xid));
+}
+
 static inline void disconnect_from_parent(struct tree_fib_xid *node)
 {
 	if (node && node->parent) {
@@ -683,6 +689,7 @@ const struct xia_ppal_rt_iops xia_ppal_tree_rt_iops = {
 
 	.fxid_ppal_alloc = tree_fxid_ppal_alloc,
 	.fxid_init = tree_fxid_init,
+	.fxid_copy = tree_fxid_copy,
 
 	/* Note that there is no RCU-specific version. */
 	.fxid_find_rcu = tree_fxid_find_rcu,