Commit 84a20d8e authored by Alexei Starovoitov's avatar Alexei Starovoitov
Browse files

Merge branch 'Sockmap copying' 

Lorenz Bauer says:

====================
Changes in v2:
- Check sk_fullsock in map_update_elem (Martin)

Enable calling map_update_elem on sockmaps from bpf_iter context. This
in turn allows us to copy a sockmap by iterating its elements.

The change itself is tiny, all thanks to the ground work from Martin,
whose series [1] this patch is based on. I updated the tests to do some
copying, and also included two cleanups.

I'm sending this out now rather than when Martin's series has landed
because I hope this can get in before the merge window (potentially)
closes this weekend.

1: https://lore.kernel.org/bpf/20200925000337.3853598-1-kafai@fb.com/


====================

Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parents efa90b50 5b87adc3

kernel/bpf/verifier.c

+1 −1
Original line number Diff line number Diff line
@@ -3943,7 +3943,7 @@ static int resolve_map_arg_type(struct bpf_verifier_env *env, 
	case BPF_MAP_TYPE_SOCKMAP:

	case BPF_MAP_TYPE_SOCKHASH:

		if (*arg_type == ARG_PTR_TO_MAP_VALUE) {

			*arg_type = ARG_PTR_TO_SOCKET;

			*arg_type = ARG_PTR_TO_BTF_ID_SOCK_COMMON;

		} else {

			verbose(env, "invalid arg_type for sockmap/sockhash\n");

			return -EINVAL;

net/core/sock_map.c

+3 −0
Original line number Diff line number Diff line
@@ -610,6 +610,9 @@ static int sock_map_update_elem(struct bpf_map *map, void *key, 
	struct sock *sk = (struct sock *)value;

	int ret;



	if (unlikely(!sk || !sk_fullsock(sk)))

		return -EINVAL;



	if (!sock_map_sk_is_suitable(sk))

		return -EOPNOTSUPP;

tools/testing/selftests/bpf/prog_tests/sockmap_basic.c

+62 −38
Original line number Diff line number Diff line
@@ -8,8 +8,6 @@ 
#include "test_sockmap_invalid_update.skel.h"

#include "bpf_iter_sockmap.skel.h"



#include "progs/bpf_iter_sockmap.h"



#define TCP_REPAIR		19	/* TCP sock is under repair right now */



#define TCP_REPAIR_ON		1
@@ -50,6 +48,37 @@ error: 
	return -1;

}



static void compare_cookies(struct bpf_map *src, struct bpf_map *dst)

{

	__u32 i, max_entries = bpf_map__max_entries(src);

	int err, duration = 0, src_fd, dst_fd;



	src_fd = bpf_map__fd(src);

	dst_fd = bpf_map__fd(dst);



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

		__u64 src_cookie, dst_cookie;



		err = bpf_map_lookup_elem(src_fd, &i, &src_cookie);

		if (err && errno == ENOENT) {

			err = bpf_map_lookup_elem(dst_fd, &i, &dst_cookie);

			CHECK(!err, "map_lookup_elem(dst)", "element %u not deleted\n", i);

			CHECK(err && errno != ENOENT, "map_lookup_elem(dst)", "%s\n",

			      strerror(errno));

			continue;

		}

		if (CHECK(err, "lookup_elem(src)", "%s\n", strerror(errno)))

			continue;



		err = bpf_map_lookup_elem(dst_fd, &i, &dst_cookie);

		if (CHECK(err, "lookup_elem(dst)", "%s\n", strerror(errno)))

			continue;



		CHECK(dst_cookie != src_cookie, "cookie mismatch",

		      "%llu != %llu (pos %u)\n", dst_cookie, src_cookie, i);

	}

}



/* Create a map, populate it with one socket, and free the map. */

static void test_sockmap_create_update_free(enum bpf_map_type map_type)

{
@@ -109,9 +138,9 @@ out: 
static void test_sockmap_update(enum bpf_map_type map_type)

{

	struct bpf_prog_test_run_attr tattr;

	int err, prog, src, dst, duration = 0;

	int err, prog, src, duration = 0;

	struct test_sockmap_update *skel;

	__u64 src_cookie, dst_cookie;

	struct bpf_map *dst_map;

	const __u32 zero = 0;

	char dummy[14] = {0};

	__s64 sk;
@@ -127,18 +156,14 @@ static void test_sockmap_update(enum bpf_map_type map_type) 
	prog = bpf_program__fd(skel->progs.copy_sock_map);

	src = bpf_map__fd(skel->maps.src);

	if (map_type == BPF_MAP_TYPE_SOCKMAP)

		dst = bpf_map__fd(skel->maps.dst_sock_map);

		dst_map = skel->maps.dst_sock_map;

	else

		dst = bpf_map__fd(skel->maps.dst_sock_hash);

		dst_map = skel->maps.dst_sock_hash;



	err = bpf_map_update_elem(src, &zero, &sk, BPF_NOEXIST);

	if (CHECK(err, "update_elem(src)", "errno=%u\n", errno))

		goto out;



	err = bpf_map_lookup_elem(src, &zero, &src_cookie);

	if (CHECK(err, "lookup_elem(src, cookie)", "errno=%u\n", errno))

		goto out;



	tattr = (struct bpf_prog_test_run_attr){

		.prog_fd = prog,

		.repeat = 1,
@@ -151,12 +176,7 @@ static void test_sockmap_update(enum bpf_map_type map_type) 
		       "errno=%u retval=%u\n", errno, tattr.retval))

		goto out;



	err = bpf_map_lookup_elem(dst, &zero, &dst_cookie);

	if (CHECK(err, "lookup_elem(dst, cookie)", "errno=%u\n", errno))

		goto out;



	CHECK(dst_cookie != src_cookie, "cookie mismatch", "%llu != %llu\n",

	      dst_cookie, src_cookie);

	compare_cookies(skel->maps.src, dst_map);



out:

	test_sockmap_update__destroy(skel);
@@ -174,14 +194,14 @@ static void test_sockmap_invalid_update(void) 
		test_sockmap_invalid_update__destroy(skel);

}



static void test_sockmap_iter(enum bpf_map_type map_type)

static void test_sockmap_copy(enum bpf_map_type map_type)

{

	DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts);

	int err, len, src_fd, iter_fd, duration = 0;

	union bpf_iter_link_info linfo = {0};

	__s64 sock_fd[SOCKMAP_MAX_ENTRIES];

	__u32 i, num_sockets, max_elems;

	__u32 i, num_sockets, num_elems;

	struct bpf_iter_sockmap *skel;

	__s64 *sock_fd = NULL;

	struct bpf_link *link;

	struct bpf_map *src;

	char buf[64];
@@ -190,22 +210,23 @@ static void test_sockmap_iter(enum bpf_map_type map_type) 
	if (CHECK(!skel, "bpf_iter_sockmap__open_and_load", "skeleton open_and_load failed\n"))

		return;



	for (i = 0; i < ARRAY_SIZE(sock_fd); i++)

		sock_fd[i] = -1;



	/* Make sure we have at least one "empty" entry to test iteration of

	 * an empty slot.

	 */

	num_sockets = ARRAY_SIZE(sock_fd) - 1;



	if (map_type == BPF_MAP_TYPE_SOCKMAP) {

		src = skel->maps.sockmap;

		max_elems = bpf_map__max_entries(src);

		num_elems = bpf_map__max_entries(src);

		num_sockets = num_elems - 1;

	} else {

		src = skel->maps.sockhash;

		max_elems = num_sockets;

		num_elems = bpf_map__max_entries(src) - 1;

		num_sockets = num_elems;

	}



	sock_fd = calloc(num_sockets, sizeof(*sock_fd));

	if (CHECK(!sock_fd, "calloc(sock_fd)", "failed to allocate\n"))

		goto out;



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

		sock_fd[i] = -1;



	src_fd = bpf_map__fd(src);



	for (i = 0; i < num_sockets; i++) {
@@ -221,7 +242,7 @@ static void test_sockmap_iter(enum bpf_map_type map_type) 
	linfo.map.map_fd = src_fd;

	opts.link_info = &linfo;

	opts.link_info_len = sizeof(linfo);

	link = bpf_program__attach_iter(skel->progs.count_elems, &opts);

	link = bpf_program__attach_iter(skel->progs.copy, &opts);

	if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n"))

		goto out;
@@ -236,23 +257,26 @@ static void test_sockmap_iter(enum bpf_map_type map_type) 
		goto close_iter;



	/* test results */

	if (CHECK(skel->bss->elems != max_elems, "elems", "got %u expected %u\n",

		  skel->bss->elems, max_elems))

	if (CHECK(skel->bss->elems != num_elems, "elems", "got %u expected %u\n",

		  skel->bss->elems, num_elems))

		goto close_iter;



	if (CHECK(skel->bss->socks != num_sockets, "socks", "got %u expected %u\n",

		  skel->bss->socks, num_sockets))

		goto close_iter;



	compare_cookies(src, skel->maps.dst);



close_iter:

	close(iter_fd);

free_link:

	bpf_link__destroy(link);

out:

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

	for (i = 0; sock_fd && i < num_sockets; i++)

		if (sock_fd[i] >= 0)

			close(sock_fd[i]);

	}

	if (sock_fd)

		free(sock_fd);

	bpf_iter_sockmap__destroy(skel);

}
@@ -272,8 +296,8 @@ void test_sockmap_basic(void) 
		test_sockmap_update(BPF_MAP_TYPE_SOCKHASH);

	if (test__start_subtest("sockmap update in unsafe context"))

		test_sockmap_invalid_update();

	if (test__start_subtest("sockmap iter"))

		test_sockmap_iter(BPF_MAP_TYPE_SOCKMAP);

	if (test__start_subtest("sockhash iter"))

		test_sockmap_iter(BPF_MAP_TYPE_SOCKHASH);

	if (test__start_subtest("sockmap copy"))

		test_sockmap_copy(BPF_MAP_TYPE_SOCKMAP);

	if (test__start_subtest("sockhash copy"))

		test_sockmap_copy(BPF_MAP_TYPE_SOCKHASH);

}

tools/testing/selftests/bpf/progs/bpf_iter_sockmap.c

+24 −8
Original line number Diff line number Diff line
@@ -2,7 +2,6 @@ 
/* Copyright (c) 2020 Cloudflare */

#include "bpf_iter.h"

#include "bpf_tracing_net.h"

#include "bpf_iter_sockmap.h"

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include <errno.h>
@@ -11,33 +10,50 @@ char _license[] SEC("license") = "GPL"; 


struct {

	__uint(type, BPF_MAP_TYPE_SOCKMAP);

	__uint(max_entries, SOCKMAP_MAX_ENTRIES);

	__uint(max_entries, 64);

	__type(key, __u32);

	__type(value, __u64);

} sockmap SEC(".maps");



struct {

	__uint(type, BPF_MAP_TYPE_SOCKHASH);

	__uint(max_entries, SOCKMAP_MAX_ENTRIES);

	__uint(max_entries, 64);

	__type(key, __u32);

	__type(value, __u64);

} sockhash SEC(".maps");



struct {

	__uint(type, BPF_MAP_TYPE_SOCKHASH);

	__uint(max_entries, 64);

	__type(key, __u32);

	__type(value, __u64);

} dst SEC(".maps");



__u32 elems = 0;

__u32 socks = 0;



SEC("iter/sockmap")

int count_elems(struct bpf_iter__sockmap *ctx)

int copy(struct bpf_iter__sockmap *ctx)

{

	struct sock *sk = ctx->sk;

	__u32 tmp, *key = ctx->key;

	int ret;



	if (key)

	if (!key)

		return 0;



	elems++;



	if (sk)

	/* We need a temporary buffer on the stack, since the verifier doesn't

	 * let us use the pointer from the context as an argument to the helper.

	 */

	tmp = *key;



	if (sk) {

		socks++;

		return bpf_map_update_elem(&dst, &tmp, sk, 0) != 0;

	}



	return 0;

	ret = bpf_map_delete_elem(&dst, &tmp);

	return ret && ret != -ENOENT;

}

tools/testing/selftests/bpf/progs/bpf_iter_sockmap.h

deleted100644 → 0
+0 −3
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */



#define SOCKMAP_MAX_ENTRIES (64)

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