Introduce common code for an associative container. This common code
will be used for maps of matches, targets, and tables. Hash search
tables from libc are used as an index.
The supported sets of operations is: create, find, upsert, free.
Co-developed-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Quentin Deslandes <qde@naccy.de>
---
net/bpfilter/Makefile | 2 +-
net/bpfilter/map-common.c | 51 +++++++++++++++
net/bpfilter/map-common.h | 19 ++++++
.../testing/selftests/bpf/bpfilter/.gitignore | 2 +
tools/testing/selftests/bpf/bpfilter/Makefile | 19 ++++++
.../testing/selftests/bpf/bpfilter/test_map.c | 63 +++++++++++++++++++
6 files changed, 155 insertions(+), 1 deletion(-)
create mode 100644 net/bpfilter/map-common.c
create mode 100644 net/bpfilter/map-common.h
create mode 100644 tools/testing/selftests/bpf/bpfilter/.gitignore
create mode 100644 tools/testing/selftests/bpf/bpfilter/Makefile
create mode 100644 tools/testing/selftests/bpf/bpfilter/test_map.c
@@ -4,7 +4,7 @@
#
userprogs := bpfilter_umh
-bpfilter_umh-objs := main.o logger.o
+bpfilter_umh-objs := main.o logger.o map-common.o
userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi
ifeq ($(CONFIG_BPFILTER_UMH), y)
new file mode 100644
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Telegram FZ-LLC
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ */
+
+#include "map-common.h"
+
+#include <linux/err.h>
+
+#include <errno.h>
+#include <string.h>
+
+int create_map(struct hsearch_data *htab, size_t nelem)
+{
+ memset(htab, 0, sizeof(*htab));
+ if (!hcreate_r(nelem, htab))
+ return -errno;
+
+ return 0;
+}
+
+void *map_find(struct hsearch_data *htab, const char *key)
+{
+ const ENTRY needle = { .key = (char *)key };
+ ENTRY *found;
+
+ if (!hsearch_r(needle, FIND, &found, htab))
+ return ERR_PTR(-ENOENT);
+
+ return found->data;
+}
+
+int map_upsert(struct hsearch_data *htab, const char *key, void *value)
+{
+ const ENTRY needle = { .key = (char *)key, .data = value };
+ ENTRY *found;
+
+ if (!hsearch_r(needle, ENTER, &found, htab))
+ return -errno;
+
+ found->key = (char *)key;
+ found->data = value;
+
+ return 0;
+}
+
+void free_map(struct hsearch_data *htab)
+{
+ hdestroy_r(htab);
+}
new file mode 100644
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2021 Telegram FZ-LLC
+ * Copyright (c) 2022 Meta Platforms, Inc. and affiliates.
+ */
+
+#ifndef NET_BPFILTER_MAP_COMMON_H
+#define NET_BPFILTER_MAP_COMMON_H
+
+#define _GNU_SOURCE
+
+#include <search.h>
+
+int create_map(struct hsearch_data *htab, size_t nelem);
+void *map_find(struct hsearch_data *htab, const char *key);
+int map_upsert(struct hsearch_data *htab, const char *key, void *value);
+void free_map(struct hsearch_data *htab);
+
+#endif // NET_BPFILTER_MAP_COMMON_H
new file mode 100644
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+test_map
new file mode 100644
@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: GPL-2.0
+
+top_srcdir = ../../../../..
+TOOLSDIR := $(abspath ../../../../)
+TOOLSINCDIR := $(TOOLSDIR)/include
+APIDIR := $(TOOLSINCDIR)/uapi
+BPFILTERSRCDIR := $(top_srcdir)/net/bpfilter
+
+CFLAGS += -Wall -g -pthread -I$(TOOLSINCDIR) -I$(APIDIR) -I$(BPFILTERSRCDIR)
+
+TEST_GEN_PROGS += test_map
+
+KSFT_KHDR_INSTALL := 1
+
+include ../../lib.mk
+
+BPFILTER_MAP_SRCS := $(BPFILTERSRCDIR)/map-common.c
+
+$(OUTPUT)/test_map: test_map.c $(BPFILTER_MAP_SRCS)
new file mode 100644
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "map-common.h"
+
+#include <linux/err.h>
+
+#include "../../kselftest_harness.h"
+
+FIXTURE(test_map)
+{
+ struct hsearch_data map;
+ const char *key;
+ void *expected;
+ void *actual;
+};
+
+FIXTURE_SETUP(test_map)
+{
+ const int max_nelements = 100;
+
+ create_map(&self->map, max_nelements);
+ self->key = "key";
+ self->expected = "expected";
+ self->actual = "actual";
+}
+
+FIXTURE_TEARDOWN(test_map)
+{
+ free_map(&self->map);
+}
+
+TEST_F(test_map, upsert_and_find)
+{
+ void *found;
+
+ found = map_find(&self->map, self->key);
+ ASSERT_TRUE(IS_ERR(found))
+ ASSERT_EQ(-ENOENT, PTR_ERR(found))
+
+ ASSERT_EQ(0, map_upsert(&self->map, self->key, self->expected));
+ ASSERT_EQ(0, map_upsert(&self->map, self->key, self->expected));
+ ASSERT_EQ(0, map_upsert(&self->map, self->key, self->actual));
+
+ found = map_find(&self->map, self->key);
+
+ ASSERT_FALSE(IS_ERR(found));
+ ASSERT_STREQ(self->actual, found);
+}
+
+TEST_F(test_map, update)
+{
+ void *found;
+
+ ASSERT_EQ(0, map_upsert(&self->map, self->key, self->actual));
+ ASSERT_EQ(0, map_upsert(&self->map, self->key, self->expected));
+
+ found = map_find(&self->map, self->key);
+
+ ASSERT_FALSE(IS_ERR(found));
+ ASSERT_STREQ(self->expected, found);
+}
+
+TEST_HARNESS_MAIN