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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:53:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:53:30 +0000
commit2c7cac91ed6e7db0f6937923d2b57f97dbdbc337 (patch)
treec05dc0f8e6aa3accc84e3e5cffc933ed94941383 /lib/srcdest_table.c
parentInitial commit. (diff)
downloadfrr-2c7cac91ed6e7db0f6937923d2b57f97dbdbc337.tar.xz
frr-2c7cac91ed6e7db0f6937923d2b57f97dbdbc337.zip
Adding upstream version 8.4.4.upstream/8.4.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--lib/srcdest_table.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/lib/srcdest_table.c b/lib/srcdest_table.c
new file mode 100644
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--- /dev/null
+++ b/lib/srcdest_table.c
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+/*
+ * SRC-DEST Routing Table
+ *
+ * Copyright (C) 2017 by David Lamparter & Christian Franke,
+ * Open Source Routing / NetDEF Inc.
+ *
+ * This file is part of FRRouting (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 this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <zebra.h>
+
+#include "srcdest_table.h"
+
+#include "memory.h"
+#include "prefix.h"
+#include "table.h"
+#include "printfrr.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 = route_table_get_info(table);
+ 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,
+ const 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);
+ route_table_set_info(srn->src_table, 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, (const struct prefix *)src_p);
+}
+
+static struct route_node *srcdest_srcnode_lookup(
+ struct route_node *rn,
+ const 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, (const 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(route_table_get_info(rn->table));
+ 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 prefixconstptr dst_pu,
+ const struct prefix_ipv6 *src_p)
+{
+ const struct prefix_ipv6 *dst_p = dst_pu.p6;
+ struct route_node *rn;
+
+ rn = route_node_get(table, (const struct prefix *)dst_p);
+ return srcdest_srcnode_get(rn, src_p);
+}
+
+struct route_node *srcdest_rnode_lookup(struct route_table *table,
+ union prefixconstptr dst_pu,
+ const struct prefix_ipv6 *src_p)
+{
+ const struct prefix_ipv6 *dst_p = dst_pu.p6;
+ struct route_node *rn;
+ struct route_node *srn;
+
+ rn = route_node_lookup_maynull(table, (const 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(const struct route_node *rn,
+ const struct prefix **p,
+ const struct prefix **src_p)
+{
+ if (rnode_is_srcnode(rn)) {
+ struct route_node *dst_rn = route_table_get_info(rn->table);
+ 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 *srcdest2str(const struct prefix *dst_p,
+ const struct prefix_ipv6 *src_p,
+ char *str, int size)
+{
+ char dst_buf[PREFIX_STRLEN], src_buf[PREFIX_STRLEN];
+
+ 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;
+}
+
+const char *srcdest_rnode2str(const struct route_node *rn, char *str, int size)
+{
+ const struct prefix *dst_p, *src_p;
+
+ srcdest_rnode_prefixes(rn, &dst_p, &src_p);
+ return srcdest2str(dst_p, (const struct prefix_ipv6 *)src_p, str, size);
+}
+
+printfrr_ext_autoreg_p("RN", printfrr_rn);
+static ssize_t printfrr_rn(struct fbuf *buf, struct printfrr_eargs *ea,
+ const void *ptr)
+{
+ const struct route_node *rn = ptr;
+ const struct prefix *dst_p, *src_p;
+ char cbuf[PREFIX_STRLEN * 2 + 6];
+
+ if (!rn)
+ return bputs(buf, "(null)");
+
+ srcdest_rnode_prefixes(rn, &dst_p, &src_p);
+ srcdest2str(dst_p, (const struct prefix_ipv6 *)src_p,
+ cbuf, sizeof(cbuf));
+ return bputs(buf, cbuf);
+}
+
+struct route_table *srcdest_srcnode_table(struct route_node *rn)
+{
+ if (rnode_is_dstnode(rn)) {
+ struct srcdest_rnode *srn = srcdest_rnode_from_rnode(rn);
+
+ return srn->src_table;
+ }
+ return NULL;
+}