Commit e4b0c94b authored by Daniel Borkmann's avatar Daniel Borkmann
Browse files

Merge branch 'bpf-libbpf-mapinmap' 



Nikita V. Shirokov says:

====================
In this patch series I'm adding a helper for libbpf which would allow
it to load map-in-map(BPF_MAP_TYPE_ARRAY_OF_MAPS and BPF_MAP_TYPE_HASH_OF_MAPS).
First patch contains new helper + explains proposed workflow second patch
contains tests which also could be used as example usage.

v4->v5:
 - naming: renamed everything to map_in_map instead of mapinmap
 - start to return nonzero val if set_inner_map_fd failed

v3->v4:
 - renamed helper to set_inner_map_fd
 - now we set this value only if it haven't
   been set before and only for (array|hash) of maps

v2->v3:
 - fixing typo in patch description
 - initializing inner_map_fd to -1 by default

v1->v2:
 - addressing nits
 - removing const identifier from fd in new helper
 - starting to check return val for bpf_map_update_elem
====================

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parents 5b32a23e b1957c92

tools/lib/bpf/libbpf.c

+34 −6
Original line number Diff line number Diff line
@@ -175,6 +175,7 @@ struct bpf_map { 
	char *name;

	size_t offset;

	int map_ifindex;

	int inner_map_fd;

	struct bpf_map_def def;

	__u32 btf_key_type_id;

	__u32 btf_value_type_id;
@@ -605,6 +606,14 @@ static int compare_bpf_map(const void *_a, const void *_b) 
	return a->offset - b->offset;

}



static bool bpf_map_type__is_map_in_map(enum bpf_map_type type)

{

	if (type == BPF_MAP_TYPE_ARRAY_OF_MAPS ||

	    type == BPF_MAP_TYPE_HASH_OF_MAPS)

		return true;

	return false;

}



static int

bpf_object__init_maps(struct bpf_object *obj, int flags)

{
@@ -668,13 +677,15 @@ bpf_object__init_maps(struct bpf_object *obj, int flags) 
	}

	obj->nr_maps = nr_maps;



	for (i = 0; i < nr_maps; i++) {

		/*

		 * fill all fd with -1 so won't close incorrect

		 * fd (fd=0 is stdin) when failure (zclose won't close

		 * negative fd)).

		 */

	for (i = 0; i < nr_maps; i++)

		obj->maps[i].fd = -1;

		obj->maps[i].inner_map_fd = -1;

	}



	/*

	 * Fill obj->maps using data in "maps" section.
@@ -1222,6 +1233,9 @@ bpf_object__create_maps(struct bpf_object *obj) 
		create_attr.btf_fd = 0;

		create_attr.btf_key_type_id = 0;

		create_attr.btf_value_type_id = 0;

		if (bpf_map_type__is_map_in_map(def->type) &&

		    map->inner_map_fd >= 0)

			create_attr.inner_map_fd = map->inner_map_fd;



		if (obj->btf && !bpf_map_find_btf_info(map, obj->btf)) {

			create_attr.btf_fd = btf__fd(obj->btf);
@@ -2681,6 +2695,20 @@ void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex) 
	map->map_ifindex = ifindex;

}



int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd)

{

	if (!bpf_map_type__is_map_in_map(map->def.type)) {

		pr_warning("error: unsupported map type\n");

		return -EINVAL;

	}

	if (map->inner_map_fd != -1) {

		pr_warning("error: inner_map_fd already specified\n");

		return -EINVAL;

	}

	map->inner_map_fd = fd;

	return 0;

}



static struct bpf_map *

__bpf_map__iter(struct bpf_map *m, struct bpf_object *obj, int i)

{

tools/lib/bpf/libbpf.h

+2 −0
Original line number Diff line number Diff line
@@ -297,6 +297,8 @@ LIBBPF_API void bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex); 
LIBBPF_API int bpf_map__pin(struct bpf_map *map, const char *path);

LIBBPF_API int bpf_map__unpin(struct bpf_map *map, const char *path);



LIBBPF_API int bpf_map__set_inner_map_fd(struct bpf_map *map, int fd);



LIBBPF_API long libbpf_get_error(const void *ptr);



struct bpf_prog_load_attr {

tools/testing/selftests/bpf/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ TEST_GEN_FILES = test_pkt_access.o test_xdp.o test_l4lb.o test_tcp_estats.o test 
	test_lwt_seg6local.o sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \

	get_cgroup_id_kern.o socket_cookie_prog.o test_select_reuseport_kern.o \

	test_skb_cgroup_id_kern.o bpf_flow.o netcnt_prog.o \

	test_sk_lookup_kern.o test_xdp_vlan.o test_queue_map.o test_stack_map.o

	test_sk_lookup_kern.o test_xdp_vlan.o test_queue_map.o test_stack_map.o \

	test_map_in_map.o



# Order correspond to 'make run_tests' order

TEST_PROGS := test_kmod.sh \

tools/testing/selftests/bpf/test_map_in_map.c

0 → 100644
+49 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* Copyright (c) 2018 Facebook */

#include <stddef.h>

#include <linux/bpf.h>

#include <linux/types.h>

#include "bpf_helpers.h"



struct bpf_map_def SEC("maps") mim_array = {

	.type = BPF_MAP_TYPE_ARRAY_OF_MAPS,

	.key_size = sizeof(int),

	/* must be sizeof(__u32) for map in map */

	.value_size = sizeof(__u32),

	.max_entries = 1,

	.map_flags = 0,

};



struct bpf_map_def SEC("maps") mim_hash = {

	.type = BPF_MAP_TYPE_HASH_OF_MAPS,

	.key_size = sizeof(int),

	/* must be sizeof(__u32) for map in map */

	.value_size = sizeof(__u32),

	.max_entries = 1,

	.map_flags = 0,

};



SEC("xdp_mimtest")

int xdp_mimtest0(struct xdp_md *ctx)

{

	int value = 123;

	int key = 0;

	void *map;



	map = bpf_map_lookup_elem(&mim_array, &key);

	if (!map)

		return XDP_DROP;



	bpf_map_update_elem(map, &key, &value, 0);



	map = bpf_map_lookup_elem(&mim_hash, &key);

	if (!map)

		return XDP_DROP;



	bpf_map_update_elem(map, &key, &value, 0);



	return XDP_PASS;

}



int _version SEC("version") = 1;

char _license[] SEC("license") = "GPL";

tools/testing/selftests/bpf/test_maps.c

+90 −0
Original line number Diff line number Diff line
@@ -1125,6 +1125,94 @@ out_sockmap: 
	exit(1);

}



#define MAPINMAP_PROG "./test_map_in_map.o"

static void test_map_in_map(void)

{

	struct bpf_program *prog;

	struct bpf_object *obj;

	struct bpf_map *map;

	int mim_fd, fd, err;

	int pos = 0;



	obj = bpf_object__open(MAPINMAP_PROG);



	fd = bpf_create_map(BPF_MAP_TYPE_HASH, sizeof(int), sizeof(int),

			    2, 0);

	if (fd < 0) {

		printf("Failed to create hashmap '%s'!\n", strerror(errno));

		exit(1);

	}



	map = bpf_object__find_map_by_name(obj, "mim_array");

	if (IS_ERR(map)) {

		printf("Failed to load array of maps from test prog\n");

		goto out_map_in_map;

	}

	err = bpf_map__set_inner_map_fd(map, fd);

	if (err) {

		printf("Failed to set inner_map_fd for array of maps\n");

		goto out_map_in_map;

	}



	map = bpf_object__find_map_by_name(obj, "mim_hash");

	if (IS_ERR(map)) {

		printf("Failed to load hash of maps from test prog\n");

		goto out_map_in_map;

	}

	err = bpf_map__set_inner_map_fd(map, fd);

	if (err) {

		printf("Failed to set inner_map_fd for hash of maps\n");

		goto out_map_in_map;

	}



	bpf_object__for_each_program(prog, obj) {

		bpf_program__set_xdp(prog);

	}

	bpf_object__load(obj);



	map = bpf_object__find_map_by_name(obj, "mim_array");

	if (IS_ERR(map)) {

		printf("Failed to load array of maps from test prog\n");

		goto out_map_in_map;

	}

	mim_fd = bpf_map__fd(map);

	if (mim_fd < 0) {

		printf("Failed to get descriptor for array of maps\n");

		goto out_map_in_map;

	}



	err = bpf_map_update_elem(mim_fd, &pos, &fd, 0);

	if (err) {

		printf("Failed to update array of maps\n");

		goto out_map_in_map;

	}



	map = bpf_object__find_map_by_name(obj, "mim_hash");

	if (IS_ERR(map)) {

		printf("Failed to load hash of maps from test prog\n");

		goto out_map_in_map;

	}

	mim_fd = bpf_map__fd(map);

	if (mim_fd < 0) {

		printf("Failed to get descriptor for hash of maps\n");

		goto out_map_in_map;

	}



	err = bpf_map_update_elem(mim_fd, &pos, &fd, 0);

	if (err) {

		printf("Failed to update hash of maps\n");

		goto out_map_in_map;

	}



	close(fd);

	bpf_object__close(obj);

	return;



out_map_in_map:

	close(fd);

	exit(1);

}



#define MAP_SIZE (32 * 1024)



static void test_map_large(void)
@@ -1600,6 +1688,8 @@ static void run_all_tests(void) 


	test_queuemap(0, NULL);

	test_stackmap(0, NULL);



	test_map_in_map();

}



int main(void)

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