diff mbox series

[bpf-next,6/6] selftests: bpf: test sockmap update from BPF

Message ID 20200819092436.58232-7-lmb@cloudflare.com (mailing list archive)
State New
Headers show
Series None | expand

Commit Message

Lorenz Bauer Aug. 19, 2020, 9:24 a.m. UTC
Add a test which copies a socket from a sockmap into another sockmap
or sockhash. This excercises bpf_map_update_elem support from BPF
context. Compare the socket cookies from source and destination to
ensure that the copy succeeded.

Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
---
 .../selftests/bpf/prog_tests/sockmap_basic.c  | 76 +++++++++++++++++++
 .../selftests/bpf/progs/test_sockmap_copy.c   | 48 ++++++++++++
 2 files changed, 124 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_copy.c

Comments

Yonghong Song Aug. 19, 2020, 8:45 p.m. UTC | #1
On 8/19/20 2:24 AM, Lorenz Bauer wrote:
> Add a test which copies a socket from a sockmap into another sockmap
> or sockhash. This excercises bpf_map_update_elem support from BPF
> context. Compare the socket cookies from source and destination to
> ensure that the copy succeeded.
> 
> Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
> ---
>   .../selftests/bpf/prog_tests/sockmap_basic.c  | 76 +++++++++++++++++++
>   .../selftests/bpf/progs/test_sockmap_copy.c   | 48 ++++++++++++
>   2 files changed, 124 insertions(+)
>   create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_copy.c
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> index 96e7b7f84c65..d30cabc00e9e 100644
> --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> @@ -4,6 +4,7 @@
>   
>   #include "test_progs.h"
>   #include "test_skmsg_load_helpers.skel.h"
> +#include "test_sockmap_copy.skel.h"
>   
>   #define TCP_REPAIR		19	/* TCP sock is under repair right now */
>   
> @@ -101,6 +102,77 @@ static void test_skmsg_helpers(enum bpf_map_type map_type)
>   	test_skmsg_load_helpers__destroy(skel);
>   }
>   
> +static void test_sockmap_copy(enum bpf_map_type map_type)
> +{
> +	struct bpf_prog_test_run_attr attr;
> +	struct test_sockmap_copy *skel;
> +	__u64 src_cookie, dst_cookie;
> +	int err, prog, s, src, dst;
> +	const __u32 zero = 0;
> +	char dummy[14] = {0};
> +
> +	s = connected_socket_v4();

Maybe change variable name to "sk" for better clarity?

> +	if (CHECK_FAIL(s == -1))
> +		return;
> +
> +	skel = test_sockmap_copy__open_and_load();
> +	if (CHECK_FAIL(!skel)) {
> +		close(s);
> +		perror("test_sockmap_copy__open_and_load");
> +		return;
> +	}

Could you use CHECK instead of CHECK_FAIL?
With CHECK, you can print additional information without perror.


> +
> +	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);
> +	else
> +		dst = bpf_map__fd(skel->maps.dst_sock_hash);
> +
> +	err = bpf_map_update_elem(src, &zero, &s, BPF_NOEXIST);

The map defined in bpf program is __u64 and here "s" is int.
Any potential issues?

> +	if (CHECK_FAIL(err)) {
> +		perror("bpf_map_update");
> +		goto out;
> +	}
> +
> +	err = bpf_map_lookup_elem(src, &zero, &src_cookie);
> +	if (CHECK_FAIL(err)) {
> +		perror("bpf_map_lookup_elem(src)");
> +		goto out;
> +	}
> +
> +	attr = (struct bpf_prog_test_run_attr){
> +		.prog_fd = prog,
> +		.repeat = 1,
> +		.data_in = dummy,
> +		.data_size_in = sizeof(dummy),
> +	};
> +
> +	err = bpf_prog_test_run_xattr(&attr);
> +	if (err) {

You can use CHECK macro here.

> +		test__fail();
> +		perror("bpf_prog_test_run");
> +		goto out;
> +	} else if (!attr.retval) {
> +		PRINT_FAIL("bpf_prog_test_run: program returned %u\n",
> +			   attr.retval);
> +		goto out;
> +	}
> +
> +	err = bpf_map_lookup_elem(dst, &zero, &dst_cookie);
> +	if (CHECK_FAIL(err)) {
> +		perror("bpf_map_lookup_elem(dst)");
> +		goto out;
> +	}
> +
> +	if (dst_cookie != src_cookie)
> +		PRINT_FAIL("cookie %llu != %llu\n", dst_cookie, src_cookie);

Just replace the whole if statement with a CHECK macro.

> +
> +out:
> +	close(s);
> +	test_sockmap_copy__destroy(skel);
> +}
> +
>   void test_sockmap_basic(void)
>   {
>   	if (test__start_subtest("sockmap create_update_free"))
> @@ -111,4 +183,8 @@ void test_sockmap_basic(void)
>   		test_skmsg_helpers(BPF_MAP_TYPE_SOCKMAP);
>   	if (test__start_subtest("sockhash sk_msg load helpers"))
>   		test_skmsg_helpers(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);
>   }
> diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_copy.c b/tools/testing/selftests/bpf/progs/test_sockmap_copy.c
> new file mode 100644
> index 000000000000..9d0c9f28cab2
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/progs/test_sockmap_copy.c
> @@ -0,0 +1,48 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (c) 2020 Cloudflare
> +#include "vmlinux.h"
> +#include <bpf/bpf_helpers.h>
> +
> +struct {
> +	__uint(type, BPF_MAP_TYPE_SOCKMAP);
> +	__uint(max_entries, 1);
> +	__type(key, __u32);
> +	__type(value, __u64);
> +} src SEC(".maps");
> +
> +struct {
> +	__uint(type, BPF_MAP_TYPE_SOCKMAP);
> +	__uint(max_entries, 1);
> +	__type(key, __u32);
> +	__type(value, __u64);
> +} dst_sock_map SEC(".maps");
> +
> +struct {
> +	__uint(type, BPF_MAP_TYPE_SOCKHASH);
> +	__uint(max_entries, 1);
> +	__type(key, __u32);
> +	__type(value, __u64);
> +} dst_sock_hash SEC(".maps");
> +
> +SEC("classifier/copy_sock_map")
> +int copy_sock_map(void *ctx)
> +{
> +	struct bpf_sock *sk;
> +	bool failed = false;
> +	__u32 key = 0;
> +
> +	sk = bpf_map_lookup_elem(&src, &key);
> +	if (!sk)
> +		return SK_DROP;
> +
> +	if (bpf_map_update_elem(&dst_sock_map, &key, sk, 0))
> +		failed = true;
> +
> +	if (bpf_map_update_elem(&dst_sock_hash, &key, sk, 0))
> +		failed = true;
> +
> +	bpf_sk_release(sk);
> +	return failed ? SK_DROP : SK_PASS;
> +}
> +
> +char _license[] SEC("license") = "GPL";
>
Lorenz Bauer Aug. 20, 2020, 11:58 a.m. UTC | #2
On Wed, 19 Aug 2020 at 21:46, Yonghong Song <yhs@fb.com> wrote:
>
>
>
> On 8/19/20 2:24 AM, Lorenz Bauer wrote:
> > Add a test which copies a socket from a sockmap into another sockmap
> > or sockhash. This excercises bpf_map_update_elem support from BPF
> > context. Compare the socket cookies from source and destination to
> > ensure that the copy succeeded.
> >
> > Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
> > ---
> >   .../selftests/bpf/prog_tests/sockmap_basic.c  | 76 +++++++++++++++++++
> >   .../selftests/bpf/progs/test_sockmap_copy.c   | 48 ++++++++++++
> >   2 files changed, 124 insertions(+)
> >   create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_copy.c
> >
> > diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> > index 96e7b7f84c65..d30cabc00e9e 100644
> > --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> > +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> > @@ -4,6 +4,7 @@
> >
> >   #include "test_progs.h"
> >   #include "test_skmsg_load_helpers.skel.h"
> > +#include "test_sockmap_copy.skel.h"
> >
> >   #define TCP_REPAIR          19      /* TCP sock is under repair right now */
> >
> > @@ -101,6 +102,77 @@ static void test_skmsg_helpers(enum bpf_map_type map_type)
> >       test_skmsg_load_helpers__destroy(skel);
> >   }
> >
> > +static void test_sockmap_copy(enum bpf_map_type map_type)
> > +{
> > +     struct bpf_prog_test_run_attr attr;
> > +     struct test_sockmap_copy *skel;
> > +     __u64 src_cookie, dst_cookie;
> > +     int err, prog, s, src, dst;
> > +     const __u32 zero = 0;
> > +     char dummy[14] = {0};
> > +
> > +     s = connected_socket_v4();
>
> Maybe change variable name to "sk" for better clarity?

Yup!

>
> > +     if (CHECK_FAIL(s == -1))
> > +             return;
> > +
> > +     skel = test_sockmap_copy__open_and_load();
> > +     if (CHECK_FAIL(!skel)) {
> > +             close(s);
> > +             perror("test_sockmap_copy__open_and_load");
> > +             return;
> > +     }
>
> Could you use CHECK instead of CHECK_FAIL?
> With CHECK, you can print additional information without perror.

I avoid CHECK because it requires `duration`, which doesn't make sense
for most things that I call CHECK_FAIL on here. So either it outputs 0
nsec (which is bogus) or it outputs the value from the last
bpf_prog_test_run call (which is also bogus). How do other tests
handle this? Just ignore it?

>
>
> > +
> > +     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);
> > +     else
> > +             dst = bpf_map__fd(skel->maps.dst_sock_hash);
> > +
> > +     err = bpf_map_update_elem(src, &zero, &s, BPF_NOEXIST);
>
> The map defined in bpf program is __u64 and here "s" is int.
> Any potential issues?

Hm, good point. This is a quirk of the sockmap API, I need to dig into
this a bit.

>
> > +     if (CHECK_FAIL(err)) {
> > +             perror("bpf_map_update");
> > +             goto out;
> > +     }
> > +
> > +     err = bpf_map_lookup_elem(src, &zero, &src_cookie);
> > +     if (CHECK_FAIL(err)) {
> > +             perror("bpf_map_lookup_elem(src)");
> > +             goto out;
> > +     }
> > +
> > +     attr = (struct bpf_prog_test_run_attr){
> > +             .prog_fd = prog,
> > +             .repeat = 1,
> > +             .data_in = dummy,
> > +             .data_size_in = sizeof(dummy),
> > +     };
> > +
> > +     err = bpf_prog_test_run_xattr(&attr);
> > +     if (err) {
>
> You can use CHECK macro here.
>
> > +             test__fail();
> > +             perror("bpf_prog_test_run");
> > +             goto out;
> > +     } else if (!attr.retval) {
> > +             PRINT_FAIL("bpf_prog_test_run: program returned %u\n",
> > +                        attr.retval);
> > +             goto out;
> > +     }
> > +
> > +     err = bpf_map_lookup_elem(dst, &zero, &dst_cookie);
> > +     if (CHECK_FAIL(err)) {
> > +             perror("bpf_map_lookup_elem(dst)");
> > +             goto out;
> > +     }
> > +
> > +     if (dst_cookie != src_cookie)
> > +             PRINT_FAIL("cookie %llu != %llu\n", dst_cookie, src_cookie);
>
> Just replace the whole if statement with a CHECK macro.

See above, re duration.

>
> > +
> > +out:
> > +     close(s);
> > +     test_sockmap_copy__destroy(skel);
> > +}
> > +
> >   void test_sockmap_basic(void)
> >   {
> >       if (test__start_subtest("sockmap create_update_free"))
> > @@ -111,4 +183,8 @@ void test_sockmap_basic(void)
> >               test_skmsg_helpers(BPF_MAP_TYPE_SOCKMAP);
> >       if (test__start_subtest("sockhash sk_msg load helpers"))
> >               test_skmsg_helpers(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);
> >   }
> > diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_copy.c b/tools/testing/selftests/bpf/progs/test_sockmap_copy.c
> > new file mode 100644
> > index 000000000000..9d0c9f28cab2
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/progs/test_sockmap_copy.c
> > @@ -0,0 +1,48 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +// Copyright (c) 2020 Cloudflare
> > +#include "vmlinux.h"
> > +#include <bpf/bpf_helpers.h>
> > +
> > +struct {
> > +     __uint(type, BPF_MAP_TYPE_SOCKMAP);
> > +     __uint(max_entries, 1);
> > +     __type(key, __u32);
> > +     __type(value, __u64);
> > +} src SEC(".maps");
> > +
> > +struct {
> > +     __uint(type, BPF_MAP_TYPE_SOCKMAP);
> > +     __uint(max_entries, 1);
> > +     __type(key, __u32);
> > +     __type(value, __u64);
> > +} dst_sock_map SEC(".maps");
> > +
> > +struct {
> > +     __uint(type, BPF_MAP_TYPE_SOCKHASH);
> > +     __uint(max_entries, 1);
> > +     __type(key, __u32);
> > +     __type(value, __u64);
> > +} dst_sock_hash SEC(".maps");
> > +
> > +SEC("classifier/copy_sock_map")
> > +int copy_sock_map(void *ctx)
> > +{
> > +     struct bpf_sock *sk;
> > +     bool failed = false;
> > +     __u32 key = 0;
> > +
> > +     sk = bpf_map_lookup_elem(&src, &key);
> > +     if (!sk)
> > +             return SK_DROP;
> > +
> > +     if (bpf_map_update_elem(&dst_sock_map, &key, sk, 0))
> > +             failed = true;
> > +
> > +     if (bpf_map_update_elem(&dst_sock_hash, &key, sk, 0))
> > +             failed = true;
> > +
> > +     bpf_sk_release(sk);
> > +     return failed ? SK_DROP : SK_PASS;
> > +}
> > +
> > +char _license[] SEC("license") = "GPL";
> >
Yonghong Song Aug. 20, 2020, 2:49 p.m. UTC | #3
On 8/20/20 4:58 AM, Lorenz Bauer wrote:
> On Wed, 19 Aug 2020 at 21:46, Yonghong Song <yhs@fb.com> wrote:
>>
>>
>>
>> On 8/19/20 2:24 AM, Lorenz Bauer wrote:
>>> Add a test which copies a socket from a sockmap into another sockmap
>>> or sockhash. This excercises bpf_map_update_elem support from BPF
>>> context. Compare the socket cookies from source and destination to
>>> ensure that the copy succeeded.
>>>
>>> Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
>>> ---
>>>    .../selftests/bpf/prog_tests/sockmap_basic.c  | 76 +++++++++++++++++++
>>>    .../selftests/bpf/progs/test_sockmap_copy.c   | 48 ++++++++++++
>>>    2 files changed, 124 insertions(+)
>>>    create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_copy.c
>>>
>>> diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
>>> index 96e7b7f84c65..d30cabc00e9e 100644
>>> --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
>>> +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
>>> @@ -4,6 +4,7 @@
>>>
>>>    #include "test_progs.h"
>>>    #include "test_skmsg_load_helpers.skel.h"
>>> +#include "test_sockmap_copy.skel.h"
>>>
>>>    #define TCP_REPAIR          19      /* TCP sock is under repair right now */
>>>
>>> @@ -101,6 +102,77 @@ static void test_skmsg_helpers(enum bpf_map_type map_type)
>>>        test_skmsg_load_helpers__destroy(skel);
>>>    }
>>>
>>> +static void test_sockmap_copy(enum bpf_map_type map_type)
>>> +{
>>> +     struct bpf_prog_test_run_attr attr;
>>> +     struct test_sockmap_copy *skel;
>>> +     __u64 src_cookie, dst_cookie;
>>> +     int err, prog, s, src, dst;
>>> +     const __u32 zero = 0;
>>> +     char dummy[14] = {0};
>>> +
>>> +     s = connected_socket_v4();
>>
>> Maybe change variable name to "sk" for better clarity?
> 
> Yup!
> 
>>
>>> +     if (CHECK_FAIL(s == -1))
>>> +             return;
>>> +
>>> +     skel = test_sockmap_copy__open_and_load();
>>> +     if (CHECK_FAIL(!skel)) {
>>> +             close(s);
>>> +             perror("test_sockmap_copy__open_and_load");
>>> +             return;
>>> +     }
>>
>> Could you use CHECK instead of CHECK_FAIL?
>> With CHECK, you can print additional information without perror.
> 
> I avoid CHECK because it requires `duration`, which doesn't make sense
> for most things that I call CHECK_FAIL on here. So either it outputs 0
> nsec (which is bogus) or it outputs the value from the last
> bpf_prog_test_run call (which is also bogus). How do other tests
> handle this? Just ignore it?

Just ignore it. You can define a static variable duration in the 
beginning of file and then use CHECK in the rest of file.

> 
>>
>>
>>> +
>>> +     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);
>>> +     else
>>> +             dst = bpf_map__fd(skel->maps.dst_sock_hash);
>>> +
[...]
Lorenz Bauer Aug. 20, 2020, 4:12 p.m. UTC | #4
On Thu, 20 Aug 2020 at 15:49, Yonghong Song <yhs@fb.com> wrote:
>
>
>
> On 8/20/20 4:58 AM, Lorenz Bauer wrote:
> > On Wed, 19 Aug 2020 at 21:46, Yonghong Song <yhs@fb.com> wrote:
> >>
> >>
> >>
> >> On 8/19/20 2:24 AM, Lorenz Bauer wrote:
> >>> Add a test which copies a socket from a sockmap into another sockmap
> >>> or sockhash. This excercises bpf_map_update_elem support from BPF
> >>> context. Compare the socket cookies from source and destination to
> >>> ensure that the copy succeeded.
> >>>
> >>> Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
> >>> ---
> >>>    .../selftests/bpf/prog_tests/sockmap_basic.c  | 76 +++++++++++++++++++
> >>>    .../selftests/bpf/progs/test_sockmap_copy.c   | 48 ++++++++++++
> >>>    2 files changed, 124 insertions(+)
> >>>    create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_copy.c
> >>>
> >>> diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> >>> index 96e7b7f84c65..d30cabc00e9e 100644
> >>> --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> >>> +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
> >>> @@ -4,6 +4,7 @@
> >>>
> >>>    #include "test_progs.h"
> >>>    #include "test_skmsg_load_helpers.skel.h"
> >>> +#include "test_sockmap_copy.skel.h"
> >>>
> >>>    #define TCP_REPAIR          19      /* TCP sock is under repair right now */
> >>>
> >>> @@ -101,6 +102,77 @@ static void test_skmsg_helpers(enum bpf_map_type map_type)
> >>>        test_skmsg_load_helpers__destroy(skel);
> >>>    }
> >>>
> >>> +static void test_sockmap_copy(enum bpf_map_type map_type)
> >>> +{
> >>> +     struct bpf_prog_test_run_attr attr;
> >>> +     struct test_sockmap_copy *skel;
> >>> +     __u64 src_cookie, dst_cookie;
> >>> +     int err, prog, s, src, dst;
> >>> +     const __u32 zero = 0;
> >>> +     char dummy[14] = {0};
> >>> +
> >>> +     s = connected_socket_v4();
> >>
> >> Maybe change variable name to "sk" for better clarity?
> >
> > Yup!
> >
> >>
> >>> +     if (CHECK_FAIL(s == -1))
> >>> +             return;
> >>> +
> >>> +     skel = test_sockmap_copy__open_and_load();
> >>> +     if (CHECK_FAIL(!skel)) {
> >>> +             close(s);
> >>> +             perror("test_sockmap_copy__open_and_load");
> >>> +             return;
> >>> +     }
> >>
> >> Could you use CHECK instead of CHECK_FAIL?
> >> With CHECK, you can print additional information without perror.
> >
> > I avoid CHECK because it requires `duration`, which doesn't make sense
> > for most things that I call CHECK_FAIL on here. So either it outputs 0
> > nsec (which is bogus) or it outputs the value from the last
> > bpf_prog_test_run call (which is also bogus). How do other tests
> > handle this? Just ignore it?
>
> Just ignore it. You can define a static variable duration in the
> beginning of file and then use CHECK in the rest of file.

Ok, will do in v3!

>
> >
> >>
> >>
> >>> +
> >>> +     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);
> >>> +     else
> >>> +             dst = bpf_map__fd(skel->maps.dst_sock_hash);
> >>> +
> [...]
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
index 96e7b7f84c65..d30cabc00e9e 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
@@ -4,6 +4,7 @@ 
 
 #include "test_progs.h"
 #include "test_skmsg_load_helpers.skel.h"
+#include "test_sockmap_copy.skel.h"
 
 #define TCP_REPAIR		19	/* TCP sock is under repair right now */
 
@@ -101,6 +102,77 @@  static void test_skmsg_helpers(enum bpf_map_type map_type)
 	test_skmsg_load_helpers__destroy(skel);
 }
 
+static void test_sockmap_copy(enum bpf_map_type map_type)
+{
+	struct bpf_prog_test_run_attr attr;
+	struct test_sockmap_copy *skel;
+	__u64 src_cookie, dst_cookie;
+	int err, prog, s, src, dst;
+	const __u32 zero = 0;
+	char dummy[14] = {0};
+
+	s = connected_socket_v4();
+	if (CHECK_FAIL(s == -1))
+		return;
+
+	skel = test_sockmap_copy__open_and_load();
+	if (CHECK_FAIL(!skel)) {
+		close(s);
+		perror("test_sockmap_copy__open_and_load");
+		return;
+	}
+
+	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);
+	else
+		dst = bpf_map__fd(skel->maps.dst_sock_hash);
+
+	err = bpf_map_update_elem(src, &zero, &s, BPF_NOEXIST);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_map_update");
+		goto out;
+	}
+
+	err = bpf_map_lookup_elem(src, &zero, &src_cookie);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_map_lookup_elem(src)");
+		goto out;
+	}
+
+	attr = (struct bpf_prog_test_run_attr){
+		.prog_fd = prog,
+		.repeat = 1,
+		.data_in = dummy,
+		.data_size_in = sizeof(dummy),
+	};
+
+	err = bpf_prog_test_run_xattr(&attr);
+	if (err) {
+		test__fail();
+		perror("bpf_prog_test_run");
+		goto out;
+	} else if (!attr.retval) {
+		PRINT_FAIL("bpf_prog_test_run: program returned %u\n",
+			   attr.retval);
+		goto out;
+	}
+
+	err = bpf_map_lookup_elem(dst, &zero, &dst_cookie);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_map_lookup_elem(dst)");
+		goto out;
+	}
+
+	if (dst_cookie != src_cookie)
+		PRINT_FAIL("cookie %llu != %llu\n", dst_cookie, src_cookie);
+
+out:
+	close(s);
+	test_sockmap_copy__destroy(skel);
+}
+
 void test_sockmap_basic(void)
 {
 	if (test__start_subtest("sockmap create_update_free"))
@@ -111,4 +183,8 @@  void test_sockmap_basic(void)
 		test_skmsg_helpers(BPF_MAP_TYPE_SOCKMAP);
 	if (test__start_subtest("sockhash sk_msg load helpers"))
 		test_skmsg_helpers(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);
 }
diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_copy.c b/tools/testing/selftests/bpf/progs/test_sockmap_copy.c
new file mode 100644
index 000000000000..9d0c9f28cab2
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_sockmap_copy.c
@@ -0,0 +1,48 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Cloudflare
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_SOCKMAP);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u64);
+} src SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_SOCKMAP);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u64);
+} dst_sock_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_SOCKHASH);
+	__uint(max_entries, 1);
+	__type(key, __u32);
+	__type(value, __u64);
+} dst_sock_hash SEC(".maps");
+
+SEC("classifier/copy_sock_map")
+int copy_sock_map(void *ctx)
+{
+	struct bpf_sock *sk;
+	bool failed = false;
+	__u32 key = 0;
+
+	sk = bpf_map_lookup_elem(&src, &key);
+	if (!sk)
+		return SK_DROP;
+
+	if (bpf_map_update_elem(&dst_sock_map, &key, sk, 0))
+		failed = true;
+
+	if (bpf_map_update_elem(&dst_sock_hash, &key, sk, 0))
+		failed = true;
+
+	bpf_sk_release(sk);
+	return failed ? SK_DROP : SK_PASS;
+}
+
+char _license[] SEC("license") = "GPL";