--- /dev/null
+/*
+ * SRC-DEST Routing Table
+ *
+ * Copyright (C) 2017 by David Lamparter & Christian Franke,
+ * Open Source Routing / NetDEF Inc.
+ *
+ * This file is part of FreeRangeRouting (FRR)
+ *
+ * FRR is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * FRR is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with FRR; see the file COPYING. If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include <zebra.h>
+
+#include "srcdest_table.h"
+
+#include "memory.h"
+#include "prefix.h"
+#include "table.h"
+
+DEFINE_MTYPE_STATIC(LIB, ROUTE_SRC_NODE, "Route source node")
+
+/* ----- functions to manage rnodes _with_ srcdest table ----- */
+struct srcdest_rnode
+{
+ /* must be first in structure for casting to/from route_node */
+ ROUTE_NODE_FIELDS;
+
+ struct route_table *src_table;
+};
+
+static struct srcdest_rnode *
+srcdest_rnode_from_rnode (struct route_node *rn)
+{
+ assert (rnode_is_dstnode (rn));
+ return (struct srcdest_rnode *) rn;
+}
+
+static struct route_node *
+srcdest_rnode_to_rnode (struct srcdest_rnode *srn)
+{
+ return (struct route_node *) srn;
+}
+
+static struct route_node *
+srcdest_rnode_create (route_table_delegate_t *delegate,
+ struct route_table *table)
+{
+ struct srcdest_rnode *srn;
+ srn = XCALLOC (MTYPE_ROUTE_NODE, sizeof (struct srcdest_rnode));
+ return srcdest_rnode_to_rnode(srn);
+}
+
+static void
+srcdest_rnode_destroy (route_table_delegate_t *delegate,
+ struct route_table *table, struct route_node *rn)
+{
+ struct srcdest_rnode *srn = srcdest_rnode_from_rnode(rn);
+ struct route_table *src_table;
+
+ /* Clear route node's src_table here already, otherwise the
+ * deletion of the last node in the src_table will trigger
+ * another call to route_table_finish for the src_table.
+ *
+ * (Compare with srcdest_srcnode_destroy)
+ */
+ src_table = srn->src_table;
+ srn->src_table = NULL;
+ route_table_finish(src_table);
+ XFREE (MTYPE_ROUTE_NODE, rn);
+}
+
+route_table_delegate_t _srcdest_dstnode_delegate = {
+ .create_node = srcdest_rnode_create,
+ .destroy_node = srcdest_rnode_destroy
+};
+
+/* ----- functions to manage rnodes _in_ srcdest table ----- */
+
+/* node creation / deletion for srcdest source prefix nodes.
+ * the route_node isn't actually different from the normal route_node,
+ * but the cleanup is special to free the table (and possibly the
+ * destination prefix's route_node) */
+
+static struct route_node *
+srcdest_srcnode_create (route_table_delegate_t *delegate,
+ struct route_table *table)
+{
+ return XCALLOC (MTYPE_ROUTE_SRC_NODE, sizeof (struct route_node));
+}
+
+static void
+srcdest_srcnode_destroy (route_table_delegate_t *delegate,
+ struct route_table *table, struct route_node *rn)
+{
+ struct srcdest_rnode *srn;
+
+ XFREE (MTYPE_ROUTE_SRC_NODE, rn);
+
+ srn = table->info;
+ if (srn->src_table && route_table_count (srn->src_table) == 0)
+ {
+ /* deleting the route_table from inside destroy_node is ONLY
+ * permitted IF table->count is 0! see lib/table.c route_node_delete()
+ * for details */
+ route_table_finish (srn->src_table);
+ srn->src_table = NULL;
+
+ /* drop the ref we're holding in srcdest_node_get(). there might be
+ * non-srcdest routes, so the route_node may still exist. hence, it's
+ * important to clear src_table above. */
+ route_unlock_node (srcdest_rnode_to_rnode (srn));
+ }
+}
+
+route_table_delegate_t _srcdest_srcnode_delegate = {
+ .create_node = srcdest_srcnode_create,
+ .destroy_node = srcdest_srcnode_destroy
+};
+
+/* NB: read comments in code for refcounting before using! */
+static struct route_node *
+srcdest_srcnode_get (struct route_node *rn, struct prefix_ipv6 *src_p)
+{
+ struct srcdest_rnode *srn;
+
+ if (!src_p || src_p->prefixlen == 0)
+ return rn;
+
+ srn = srcdest_rnode_from_rnode (rn);
+ if (!srn->src_table)
+ {
+ /* this won't use srcdest_rnode, we're already on the source here */
+ srn->src_table = route_table_init_with_delegate (&_srcdest_srcnode_delegate);
+ srn->src_table->info = srn;
+
+ /* there is no route_unlock_node on the original rn here.
+ * The reference is kept for the src_table. */
+ }
+ else
+ {
+ /* only keep 1 reference for the src_table, makes the refcounting
+ * more similar to the non-srcdest case. Either way after return from
+ * function, the only reference held is the one on the return value.
+ *
+ * We can safely drop our reference here because src_table is holding
+ * another reference, so this won't free rn */
+ route_unlock_node (rn);
+ }
+
+ return route_node_get (srn->src_table, (struct prefix *)src_p);
+}
+
+static struct route_node *
+srcdest_srcnode_lookup (struct route_node *rn, struct prefix_ipv6 *src_p)
+{
+ struct srcdest_rnode *srn;
+
+ if (!rn || !src_p || src_p->prefixlen == 0)
+ return rn;
+
+ /* We got this rn from a lookup, so its refcnt was incremented. As we won't
+ * return return rn from any point beyond here, we should decrement its refcnt.
+ */
+ route_unlock_node (rn);
+
+ srn = srcdest_rnode_from_rnode (rn);
+ if (!srn->src_table)
+ return NULL;
+
+ return route_node_lookup (srn->src_table, (struct prefix *)src_p);
+}
+
+/* ----- exported functions ----- */
+
+struct route_table *
+srcdest_table_init(void)
+{
+ return route_table_init_with_delegate(&_srcdest_dstnode_delegate);
+}
+
+struct route_node *
+srcdest_route_next(struct route_node *rn)
+{
+ struct route_node *next, *parent;
+
+ /* For a non src-dest node, just return route_next */
+ if (!(rnode_is_dstnode(rn) || rnode_is_srcnode(rn)))
+ return route_next(rn);
+
+ if (rnode_is_dstnode(rn))
+ {
+ /* This means the route_node is part of the top hierarchy
+ * and refers to a destination prefix. */
+ struct srcdest_rnode *srn = srcdest_rnode_from_rnode(rn);
+
+ if (srn->src_table)
+ next = route_top(srn->src_table);
+ else
+ next = NULL;
+
+ if (next)
+ {
+ /* There is a source prefix. Return the node for it */
+ route_unlock_node(rn);
+ return next;
+ }
+ else
+ {
+ /* There is no source prefix, just continue as usual */
+ return route_next(rn);
+ }
+ }
+
+ /* This part handles the case of iterating source nodes. */
+ parent = route_lock_node(rn->table->info);
+ next = route_next(rn);
+
+ if (next)
+ {
+ /* There is another source node, continue in the source table */
+ route_unlock_node(parent);
+ return next;
+ }
+ else
+ {
+ /* The source table is complete, continue in the parent table */
+ return route_next(parent);
+ }
+}
+
+struct route_node *
+srcdest_rnode_get (struct route_table *table, union prefix46ptr dst_pu,
+ struct prefix_ipv6 *src_p)
+{
+ struct prefix_ipv6 *dst_p = dst_pu.p6;
+ struct route_node *rn;
+
+ rn = route_node_get (table, (struct prefix *) dst_p);
+ return srcdest_srcnode_get (rn, src_p);
+}
+
+struct route_node *
+srcdest_rnode_lookup (struct route_table *table, union prefix46ptr dst_pu,
+ struct prefix_ipv6 *src_p)
+{
+ struct prefix_ipv6 *dst_p = dst_pu.p6;
+ struct route_node *rn;
+ struct route_node *srn;
+
+ rn = route_node_lookup_maynull (table, (struct prefix *) dst_p);
+ srn = srcdest_srcnode_lookup (rn, src_p);
+
+ if (rn != NULL && rn == srn && !rn->info)
+ {
+ /* Match the behavior of route_node_lookup and don't return an
+ * empty route-node for a dest-route */
+ route_unlock_node(rn);
+ return NULL;
+ }
+ return srn;
+}
+
+void
+srcdest_rnode_prefixes (struct route_node *rn, struct prefix **p,
+ struct prefix **src_p)
+{
+ if (rnode_is_srcnode (rn))
+ {
+ struct route_node *dst_rn = rn->table->info;
+ if (p)
+ *p = &dst_rn->p;
+ if (src_p)
+ *src_p = &rn->p;
+ }
+ else
+ {
+ if (p)
+ *p = &rn->p;
+ if (src_p)
+ *src_p = NULL;
+ }
+}
+
+const char *
+srcdest_rnode2str (struct route_node *rn, char *str, int size)
+{
+ struct prefix *dst_p, *src_p;
+ char dst_buf[PREFIX_STRLEN], src_buf[PREFIX_STRLEN];
+
+ srcdest_rnode_prefixes(rn, &dst_p, &src_p);
+
+ snprintf(str, size, "%s%s%s",
+ prefix2str(dst_p, dst_buf, sizeof(dst_buf)),
+ (src_p && src_p->prefixlen) ? " from " : "",
+ (src_p && src_p->prefixlen) ? prefix2str(src_p, src_buf,
+ sizeof(src_buf))
+ : "");
+ return str;
+}
--- /dev/null
+/*
+ * SRC-DEST Routing Table
+ *
+ * Copyright (C) 2017 by David Lamparter & Christian Franke,
+ * Open Source Routing / NetDEF Inc.
+ *
+ * This file is part of FreeRangeRouting (FRR)
+ *
+ * FRR is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * FRR is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with FRR; see the file COPYING. If not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#ifndef _ZEBRA_SRC_DEST_TABLE_H
+#define _ZEBRA_SRC_DEST_TABLE_H
+
+/* old/IPv4/non-srcdest:
+ * table -> route_node .info -> [obj]
+ *
+ * new/IPv6/srcdest:
+ * table -...-> srcdest_rnode [prefix = dest] .info -> [obj]
+ * .src_table ->
+ * srcdest table -...-> route_node [prefix = src] .info -> [obj]
+ *
+ * non-srcdest routes (src = ::/0) are treated just like before, their
+ * information being directly there in the info pointer.
+ *
+ * srcdest routes are found by looking up destination first, then looking
+ * up the source in the "src_table". src_table contains normal route_nodes,
+ * whose prefix is the _source_ prefix.
+ *
+ * NB: info can be NULL on the destination rnode, if there are only srcdest
+ * routes for a particular destination prefix.
+ */
+
+#include "prefix.h"
+#include "table.h"
+
+#define SRCDEST2STR_BUFFER (2*PREFIX2STR_BUFFER + sizeof(" from "))
+
+/* extended route node for IPv6 srcdest routing */
+struct srcdest_rnode;
+
+extern route_table_delegate_t _srcdest_dstnode_delegate;
+extern route_table_delegate_t _srcdest_srcnode_delegate;
+
+extern struct route_table *srcdest_table_init(void);
+extern struct route_node *srcdest_rnode_get(struct route_table *table,
+ union prefix46ptr dst_pu,
+ struct prefix_ipv6 *src_p);
+extern struct route_node *srcdest_rnode_lookup(struct route_table *table,
+ union prefix46ptr dst_pu,
+ struct prefix_ipv6 *src_p);
+extern void srcdest_rnode_prefixes (struct route_node *rn, struct prefix **p,
+ struct prefix **src_p);
+extern const char *srcdest_rnode2str(struct route_node *rn, char *str, int size);
+extern struct route_node *srcdest_route_next(struct route_node *rn);
+
+static inline int
+rnode_is_dstnode (struct route_node *rn)
+{
+ return rn->table->delegate == &_srcdest_dstnode_delegate;
+}
+
+static inline int
+rnode_is_srcnode (struct route_node *rn)
+{
+ return rn->table->delegate == &_srcdest_srcnode_delegate;
+}
+
+static inline struct route_table *
+srcdest_rnode_table (struct route_node *rn)
+{
+ if (rnode_is_srcnode (rn))
+ {
+ struct route_node *dst_rn = rn->table->info;
+ return dst_rn->table;
+ }
+ else
+ {
+ return rn->table;
+ }
+}
+static inline void *
+srcdest_rnode_table_info (struct route_node *rn)
+{
+ return srcdest_rnode_table(rn)->info;
+}
+
+#endif /* _ZEBRA_SRC_DEST_TABLE_H */
projects / matthieu / frr.git / commitdiff