[dpdk-dev] [PATCH] lpm: rte_lpm_iterate() - iterate through the routes

chunguang yang chunguang.yang at windriver.com
Fri Nov 25 07:31:31 CET 2016


From: Jörgen Grahn <grahn+src at snipabacken.se>

In practice, there's a need to iterate through the entries
of a rte_lpm, apart from the usual insert/delete/lookup
operations.  This is useful for debugging and perhaps for
things like removing all entries referencing a certain nexthop.

This patch implements this through rte_lpm_iterate(), which
uses a cursor (or iterator) to keep track of the current
position.  Client code doesn't need to be aware of rte_lpm
implementation details.

Change-Id: I28ea3d7d92f318988444553ee2bb30b709bcb3b6
Signed-off-by: Jorgen Grahn <jorgen.grahn at hiq.se>
Signed-off-by: alloc <alloc.young at gmail.com>
---
 lib/librte_lpm/Makefile          |  4 +-
 lib/librte_lpm/rte_lpm_iterate.c | 81 ++++++++++++++++++++++++++++++++++++++++
 lib/librte_lpm/rte_lpm_iterate.h | 56 +++++++++++++++++++++++++++
 3 files changed, 139 insertions(+), 2 deletions(-)
 create mode 100644 lib/librte_lpm/rte_lpm_iterate.c
 create mode 100644 lib/librte_lpm/rte_lpm_iterate.h

diff --git a/lib/librte_lpm/Makefile b/lib/librte_lpm/Makefile
index 3dc549d..c45da19 100644
--- a/lib/librte_lpm/Makefile
+++ b/lib/librte_lpm/Makefile
@@ -42,10 +42,10 @@ EXPORT_MAP := rte_lpm_version.map
 LIBABIVER := 2
 
 # all source are stored in SRCS-y
-SRCS-$(CONFIG_RTE_LIBRTE_LPM) := rte_lpm.c rte_lpm6.c
+SRCS-$(CONFIG_RTE_LIBRTE_LPM) := rte_lpm.c rte_lpm6.c rte_lpm_iterate.c
 
 # install this header file
-SYMLINK-$(CONFIG_RTE_LIBRTE_LPM)-include := rte_lpm.h rte_lpm6.h
+SYMLINK-$(CONFIG_RTE_LIBRTE_LPM)-include := rte_lpm.h rte_lpm6.h rte_lpm_iterate.h
 
 ifneq ($(filter y,$(CONFIG_RTE_ARCH_ARM) $(CONFIG_RTE_ARCH_ARM64)),)
 SYMLINK-$(CONFIG_RTE_LIBRTE_LPM)-include += rte_lpm_neon.h
diff --git a/lib/librte_lpm/rte_lpm_iterate.c b/lib/librte_lpm/rte_lpm_iterate.c
new file mode 100644
index 0000000..f643764
--- /dev/null
+++ b/lib/librte_lpm/rte_lpm_iterate.c
@@ -0,0 +1,81 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2014 Jörgen Grahn. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "rte_lpm_iterate.h"
+#include "rte_lpm.h"
+
+#include <arpa/inet.h>
+
+
+/**
+ * Iterate through the lpm, pulling out at most 'buflen' valid routes
+ * (less means we've hit the end).  The cursor should be initialized
+ * to { 0, 0 } before the first call.
+ *
+ * The routes are partially sorted, by prefix length.  Undefined
+ * results if the lpm is modified in parallel with or inbetween calls,
+ * although the iteration will still terminate properly.
+ */
+unsigned
+rte_lpm_iterate(struct rte_lpm_route* const buf, unsigned buflen,
+		const struct rte_lpm* lpm,
+		struct rte_lpm_cursor* const cursor)
+{
+	struct rte_lpm_route* p = buf;
+	struct rte_lpm_route* const end = p + buflen;
+
+	const struct rte_lpm_rule_info* const rinfo = lpm->rule_info;
+	const struct rte_lpm_rule* const rtbl = lpm->rules_tbl;
+
+	unsigned d = cursor->d;
+	unsigned n = cursor->n;
+
+	while(p!=end) {
+		if(d==32) break;
+		if(n>=rinfo[d].used_rules) {
+			d++;
+			n = 0;
+			continue;
+		}
+		const struct rte_lpm_rule rule = rtbl[rinfo[d].first_rule + n];
+		p->addr.s_addr = htonl(rule.ip);
+		p->plen = d+1;
+		p->nh = rule.next_hop;
+		p++;
+		n++;
+	}
+
+	cursor->d = d;
+	cursor->n = n;
+
+	return p - buf;
+}
diff --git a/lib/librte_lpm/rte_lpm_iterate.h b/lib/librte_lpm/rte_lpm_iterate.h
new file mode 100644
index 0000000..25c7841
--- /dev/null
+++ b/lib/librte_lpm/rte_lpm_iterate.h
@@ -0,0 +1,56 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2014 Jörgen Grahn. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef _RTE_LPM_ITERATE_H_
+#define _RTE_LPM_ITERATE_H_
+
+#include <stdint.h>
+#include <netinet/in.h>
+
+struct rte_lpm;
+
+struct rte_lpm_cursor {
+	unsigned d;
+	unsigned n;
+};
+
+struct rte_lpm_route {
+	struct in_addr addr;
+	uint8_t plen;
+	uint8_t nh;
+};
+
+unsigned rte_lpm_iterate(struct rte_lpm_route* buf, unsigned buflen,
+			 const struct rte_lpm* lpm,
+			 struct rte_lpm_cursor* cursor);
+
+#endif
-- 
2.7.4



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