diff mbox series

[v1,bpf-next,11/11] bpf: Test BPF_SK_REUSEPORT_SELECT_OR_MIGRATE.

Message ID 20201201144418.35045-12-kuniyu@amazon.co.jp
State New
Headers show
Series Socket migration for SO_REUSEPORT. | expand

Commit Message

Kuniyuki Iwashima Dec. 1, 2020, 2:44 p.m. UTC
This patch adds a test for BPF_SK_REUSEPORT_SELECT_OR_MIGRATE.

Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
---
 .../bpf/prog_tests/migrate_reuseport.c        | 164 ++++++++++++++++++
 .../bpf/progs/test_migrate_reuseport_kern.c   |  54 ++++++
 2 files changed, 218 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
 create mode 100644 tools/testing/selftests/bpf/progs/test_migrate_reuseport_kern.c

Comments

Martin KaFai Lau Dec. 5, 2020, 1:50 a.m. UTC | #1
On Tue, Dec 01, 2020 at 11:44:18PM +0900, Kuniyuki Iwashima wrote:
> This patch adds a test for BPF_SK_REUSEPORT_SELECT_OR_MIGRATE.
> 
> Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
> ---
>  .../bpf/prog_tests/migrate_reuseport.c        | 164 ++++++++++++++++++
>  .../bpf/progs/test_migrate_reuseport_kern.c   |  54 ++++++
>  2 files changed, 218 insertions(+)
>  create mode 100644 tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
>  create mode 100644 tools/testing/selftests/bpf/progs/test_migrate_reuseport_kern.c
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
> new file mode 100644
> index 000000000000..87c72d9ccadd
> --- /dev/null
> +++ b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
> @@ -0,0 +1,164 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Check if we can migrate child sockets.
> + *
> + *   1. call listen() for 5 server sockets.
> + *   2. update a map to migrate all child socket
> + *        to the last server socket (migrate_map[cookie] = 4)
> + *   3. call connect() for 25 client sockets.
> + *   4. call close() for first 4 server sockets.
> + *   5. call accept() for the last server socket.
> + *
> + * Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
> + */
> +
> +#include <stdlib.h>
> +#include <unistd.h>
> +#include <fcntl.h>
> +#include <netinet/in.h>
> +#include <arpa/inet.h>
> +#include <linux/bpf.h>
> +#include <sys/socket.h>
> +#include <sys/types.h>
> +#include <bpf/bpf.h>
> +#include <bpf/libbpf.h>
> +
> +#define NUM_SOCKS 5
> +#define LOCALHOST "127.0.0.1"
> +#define err_exit(condition, message)			      \
> +	do {						      \
> +		if (condition) {			      \
> +			perror("ERROR: " message " ");	      \
> +			exit(1);			      \
> +		}					      \
> +	} while (0)
> +
> +__u64 server_fds[NUM_SOCKS];
> +int prog_fd, reuseport_map_fd, migrate_map_fd;
> +
> +
> +void setup_bpf(void)
> +{
> +	struct bpf_object *obj;
> +	struct bpf_program *prog;
> +	struct bpf_map *reuseport_map, *migrate_map;
> +	int err;
> +
> +	obj = bpf_object__open("test_migrate_reuseport_kern.o");
> +	err_exit(libbpf_get_error(obj), "opening BPF object file failed");
> +
> +	err = bpf_object__load(obj);
> +	err_exit(err, "loading BPF object failed");
> +
> +	prog = bpf_program__next(NULL, obj);
> +	err_exit(!prog, "loading BPF program failed");
> +
> +	reuseport_map = bpf_object__find_map_by_name(obj, "reuseport_map");
> +	err_exit(!reuseport_map, "loading BPF reuseport_map failed");
> +
> +	migrate_map = bpf_object__find_map_by_name(obj, "migrate_map");
> +	err_exit(!migrate_map, "loading BPF migrate_map failed");
> +
> +	prog_fd = bpf_program__fd(prog);
> +	reuseport_map_fd = bpf_map__fd(reuseport_map);
> +	migrate_map_fd = bpf_map__fd(migrate_map);
> +}
> +
> +void test_listen(void)
> +{
> +	struct sockaddr_in addr;
> +	socklen_t addr_len = sizeof(addr);
> +	int i, err, optval = 1, migrated_to = NUM_SOCKS - 1;
> +	__u64 value;
> +
> +	addr.sin_family = AF_INET;
> +	addr.sin_port = htons(80);
> +	inet_pton(AF_INET, LOCALHOST, &addr.sin_addr.s_addr);
> +
> +	for (i = 0; i < NUM_SOCKS; i++) {
> +		server_fds[i] = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
> +		err_exit(server_fds[i] == -1, "socket() for listener sockets failed");
> +
> +		err = setsockopt(server_fds[i], SOL_SOCKET, SO_REUSEPORT,
> +				 &optval, sizeof(optval));
> +		err_exit(err == -1, "setsockopt() for SO_REUSEPORT failed");
> +
> +		if (i == 0) {
> +			err = setsockopt(server_fds[i], SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF,
> +					 &prog_fd, sizeof(prog_fd));
> +			err_exit(err == -1, "setsockopt() for SO_ATTACH_REUSEPORT_EBPF failed");
> +		}
> +
> +		err = bind(server_fds[i], (struct sockaddr *)&addr, addr_len);
> +		err_exit(err == -1, "bind() failed");
> +
> +		err = listen(server_fds[i], 32);
> +		err_exit(err == -1, "listen() failed");
> +
> +		err = bpf_map_update_elem(reuseport_map_fd, &i, &server_fds[i], BPF_NOEXIST);
> +		err_exit(err == -1, "updating BPF reuseport_map failed");
> +
> +		err = bpf_map_lookup_elem(reuseport_map_fd, &i, &value);
> +		err_exit(err == -1, "looking up BPF reuseport_map failed");
> +
> +		printf("fd[%d] (cookie: %llu) -> fd[%d]\n", i, value, migrated_to);
> +		err = bpf_map_update_elem(migrate_map_fd, &value, &migrated_to, BPF_NOEXIST);
> +		err_exit(err == -1, "updating BPF migrate_map failed");
> +	}
> +}
> +
> +void test_connect(void)
> +{
> +	struct sockaddr_in addr;
> +	socklen_t addr_len = sizeof(addr);
> +	int i, err, client_fd;
> +
> +	addr.sin_family = AF_INET;
> +	addr.sin_port = htons(80);
> +	inet_pton(AF_INET, LOCALHOST, &addr.sin_addr.s_addr);
> +
> +	for (i = 0; i < NUM_SOCKS * 5; i++) {
> +		client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
> +		err_exit(client_fd == -1, "socket() for listener sockets failed");
> +
> +		err = connect(client_fd, (struct sockaddr *)&addr, addr_len);
> +		err_exit(err == -1, "connect() failed");
> +
> +		close(client_fd);
> +	}
> +}
> +
> +void test_close(void)
> +{
> +	int i;
> +
> +	for (i = 0; i < NUM_SOCKS - 1; i++)
> +		close(server_fds[i]);
> +}
> +
> +void test_accept(void)
> +{
> +	struct sockaddr_in addr;
> +	socklen_t addr_len = sizeof(addr);
> +	int cnt, client_fd;
> +
> +	fcntl(server_fds[NUM_SOCKS - 1], F_SETFL, O_NONBLOCK);
> +
> +	for (cnt = 0; cnt < NUM_SOCKS * 5; cnt++) {
> +		client_fd = accept(server_fds[NUM_SOCKS - 1], (struct sockaddr *)&addr, &addr_len);
> +		err_exit(client_fd == -1, "accept() failed");
> +	}
> +
> +	printf("%d accepted, %d is expected\n", cnt, NUM_SOCKS * 5);
> +}
> +
> +int main(void)
I am pretty sure "make -C tools/testing/selftests/bpf"
will not compile here because of double main() with
the test_progs.c.

Please take a look at how other tests are written in
tools/testing/selftests/bpf/prog_tests/. e.g.
the test function in tcp_hdr_options.c is
test_tcp_hdr_options().

Also, instead of bpf_object__open(), please use skeleton
like most of the tests do.


> +{
> +	setup_bpf();
> +	test_listen();
> +	test_connect();
> +	test_close();
> +	test_accept();
> +	close(server_fds[NUM_SOCKS - 1]);
> +	return 0;
> +}
Kuniyuki Iwashima Dec. 6, 2020, 4:43 a.m. UTC | #2
I'm sending this mail just for logging because I failed to send mails only 
to LKML, netdev, and bpf yesterday.


From:   Martin KaFai Lau <kafai@fb.com>
Date:   Fri, 4 Dec 2020 17:50:00 -0800
> On Tue, Dec 01, 2020 at 11:44:18PM +0900, Kuniyuki Iwashima wrote:
> > This patch adds a test for BPF_SK_REUSEPORT_SELECT_OR_MIGRATE.
> > 
> > Reviewed-by: Benjamin Herrenschmidt <benh@amazon.com>
> > Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
> > ---
> >  .../bpf/prog_tests/migrate_reuseport.c        | 164 ++++++++++++++++++
> >  .../bpf/progs/test_migrate_reuseport_kern.c   |  54 ++++++
> >  2 files changed, 218 insertions(+)
> >  create mode 100644 tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
> >  create mode 100644 tools/testing/selftests/bpf/progs/test_migrate_reuseport_kern.c
> > 
> > diff --git a/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
> > new file mode 100644
> > index 000000000000..87c72d9ccadd
> > --- /dev/null
> > +++ b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
> > @@ -0,0 +1,164 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Check if we can migrate child sockets.
> > + *
> > + *   1. call listen() for 5 server sockets.
> > + *   2. update a map to migrate all child socket
> > + *        to the last server socket (migrate_map[cookie] = 4)
> > + *   3. call connect() for 25 client sockets.
> > + *   4. call close() for first 4 server sockets.
> > + *   5. call accept() for the last server socket.
> > + *
> > + * Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
> > + */
> > +
> > +#include <stdlib.h>
> > +#include <unistd.h>
> > +#include <fcntl.h>
> > +#include <netinet/in.h>
> > +#include <arpa/inet.h>
> > +#include <linux/bpf.h>
> > +#include <sys/socket.h>
> > +#include <sys/types.h>
> > +#include <bpf/bpf.h>
> > +#include <bpf/libbpf.h>
> > +
> > +#define NUM_SOCKS 5
> > +#define LOCALHOST "127.0.0.1"
> > +#define err_exit(condition, message)			      \
> > +	do {						      \
> > +		if (condition) {			      \
> > +			perror("ERROR: " message " ");	      \
> > +			exit(1);			      \
> > +		}					      \
> > +	} while (0)
> > +
> > +__u64 server_fds[NUM_SOCKS];
> > +int prog_fd, reuseport_map_fd, migrate_map_fd;
> > +
> > +
> > +void setup_bpf(void)
> > +{
> > +	struct bpf_object *obj;
> > +	struct bpf_program *prog;
> > +	struct bpf_map *reuseport_map, *migrate_map;
> > +	int err;
> > +
> > +	obj = bpf_object__open("test_migrate_reuseport_kern.o");
> > +	err_exit(libbpf_get_error(obj), "opening BPF object file failed");
> > +
> > +	err = bpf_object__load(obj);
> > +	err_exit(err, "loading BPF object failed");
> > +
> > +	prog = bpf_program__next(NULL, obj);
> > +	err_exit(!prog, "loading BPF program failed");
> > +
> > +	reuseport_map = bpf_object__find_map_by_name(obj, "reuseport_map");
> > +	err_exit(!reuseport_map, "loading BPF reuseport_map failed");
> > +
> > +	migrate_map = bpf_object__find_map_by_name(obj, "migrate_map");
> > +	err_exit(!migrate_map, "loading BPF migrate_map failed");
> > +
> > +	prog_fd = bpf_program__fd(prog);
> > +	reuseport_map_fd = bpf_map__fd(reuseport_map);
> > +	migrate_map_fd = bpf_map__fd(migrate_map);
> > +}
> > +
> > +void test_listen(void)
> > +{
> > +	struct sockaddr_in addr;
> > +	socklen_t addr_len = sizeof(addr);
> > +	int i, err, optval = 1, migrated_to = NUM_SOCKS - 1;
> > +	__u64 value;
> > +
> > +	addr.sin_family = AF_INET;
> > +	addr.sin_port = htons(80);
> > +	inet_pton(AF_INET, LOCALHOST, &addr.sin_addr.s_addr);
> > +
> > +	for (i = 0; i < NUM_SOCKS; i++) {
> > +		server_fds[i] = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
> > +		err_exit(server_fds[i] == -1, "socket() for listener sockets failed");
> > +
> > +		err = setsockopt(server_fds[i], SOL_SOCKET, SO_REUSEPORT,
> > +				 &optval, sizeof(optval));
> > +		err_exit(err == -1, "setsockopt() for SO_REUSEPORT failed");
> > +
> > +		if (i == 0) {
> > +			err = setsockopt(server_fds[i], SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF,
> > +					 &prog_fd, sizeof(prog_fd));
> > +			err_exit(err == -1, "setsockopt() for SO_ATTACH_REUSEPORT_EBPF failed");
> > +		}
> > +
> > +		err = bind(server_fds[i], (struct sockaddr *)&addr, addr_len);
> > +		err_exit(err == -1, "bind() failed");
> > +
> > +		err = listen(server_fds[i], 32);
> > +		err_exit(err == -1, "listen() failed");
> > +
> > +		err = bpf_map_update_elem(reuseport_map_fd, &i, &server_fds[i], BPF_NOEXIST);
> > +		err_exit(err == -1, "updating BPF reuseport_map failed");
> > +
> > +		err = bpf_map_lookup_elem(reuseport_map_fd, &i, &value);
> > +		err_exit(err == -1, "looking up BPF reuseport_map failed");
> > +
> > +		printf("fd[%d] (cookie: %llu) -> fd[%d]\n", i, value, migrated_to);
> > +		err = bpf_map_update_elem(migrate_map_fd, &value, &migrated_to, BPF_NOEXIST);
> > +		err_exit(err == -1, "updating BPF migrate_map failed");
> > +	}
> > +}
> > +
> > +void test_connect(void)
> > +{
> > +	struct sockaddr_in addr;
> > +	socklen_t addr_len = sizeof(addr);
> > +	int i, err, client_fd;
> > +
> > +	addr.sin_family = AF_INET;
> > +	addr.sin_port = htons(80);
> > +	inet_pton(AF_INET, LOCALHOST, &addr.sin_addr.s_addr);
> > +
> > +	for (i = 0; i < NUM_SOCKS * 5; i++) {
> > +		client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
> > +		err_exit(client_fd == -1, "socket() for listener sockets failed");
> > +
> > +		err = connect(client_fd, (struct sockaddr *)&addr, addr_len);
> > +		err_exit(err == -1, "connect() failed");
> > +
> > +		close(client_fd);
> > +	}
> > +}
> > +
> > +void test_close(void)
> > +{
> > +	int i;
> > +
> > +	for (i = 0; i < NUM_SOCKS - 1; i++)
> > +		close(server_fds[i]);
> > +}
> > +
> > +void test_accept(void)
> > +{
> > +	struct sockaddr_in addr;
> > +	socklen_t addr_len = sizeof(addr);
> > +	int cnt, client_fd;
> > +
> > +	fcntl(server_fds[NUM_SOCKS - 1], F_SETFL, O_NONBLOCK);
> > +
> > +	for (cnt = 0; cnt < NUM_SOCKS * 5; cnt++) {
> > +		client_fd = accept(server_fds[NUM_SOCKS - 1], (struct sockaddr *)&addr, &addr_len);
> > +		err_exit(client_fd == -1, "accept() failed");
> > +	}
> > +
> > +	printf("%d accepted, %d is expected\n", cnt, NUM_SOCKS * 5);
> > +}
> > +
> > +int main(void)
> I am pretty sure "make -C tools/testing/selftests/bpf"
> will not compile here because of double main() with
> the test_progs.c.
> 
> Please take a look at how other tests are written in
> tools/testing/selftests/bpf/prog_tests/. e.g.
> the test function in tcp_hdr_options.c is
> test_tcp_hdr_options().
> 
> Also, instead of bpf_object__open(), please use skeleton
> like most of the tests do.

I'm sorry... I will check other tests and rewrite this patch along them.
diff mbox series

Patch

diff --git a/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
new file mode 100644
index 000000000000..87c72d9ccadd
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
@@ -0,0 +1,164 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Check if we can migrate child sockets.
+ *
+ *   1. call listen() for 5 server sockets.
+ *   2. update a map to migrate all child socket
+ *        to the last server socket (migrate_map[cookie] = 4)
+ *   3. call connect() for 25 client sockets.
+ *   4. call close() for first 4 server sockets.
+ *   5. call accept() for the last server socket.
+ *
+ * Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
+ */
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <linux/bpf.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#define NUM_SOCKS 5
+#define LOCALHOST "127.0.0.1"
+#define err_exit(condition, message)			      \
+	do {						      \
+		if (condition) {			      \
+			perror("ERROR: " message " ");	      \
+			exit(1);			      \
+		}					      \
+	} while (0)
+
+__u64 server_fds[NUM_SOCKS];
+int prog_fd, reuseport_map_fd, migrate_map_fd;
+
+
+void setup_bpf(void)
+{
+	struct bpf_object *obj;
+	struct bpf_program *prog;
+	struct bpf_map *reuseport_map, *migrate_map;
+	int err;
+
+	obj = bpf_object__open("test_migrate_reuseport_kern.o");
+	err_exit(libbpf_get_error(obj), "opening BPF object file failed");
+
+	err = bpf_object__load(obj);
+	err_exit(err, "loading BPF object failed");
+
+	prog = bpf_program__next(NULL, obj);
+	err_exit(!prog, "loading BPF program failed");
+
+	reuseport_map = bpf_object__find_map_by_name(obj, "reuseport_map");
+	err_exit(!reuseport_map, "loading BPF reuseport_map failed");
+
+	migrate_map = bpf_object__find_map_by_name(obj, "migrate_map");
+	err_exit(!migrate_map, "loading BPF migrate_map failed");
+
+	prog_fd = bpf_program__fd(prog);
+	reuseport_map_fd = bpf_map__fd(reuseport_map);
+	migrate_map_fd = bpf_map__fd(migrate_map);
+}
+
+void test_listen(void)
+{
+	struct sockaddr_in addr;
+	socklen_t addr_len = sizeof(addr);
+	int i, err, optval = 1, migrated_to = NUM_SOCKS - 1;
+	__u64 value;
+
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(80);
+	inet_pton(AF_INET, LOCALHOST, &addr.sin_addr.s_addr);
+
+	for (i = 0; i < NUM_SOCKS; i++) {
+		server_fds[i] = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+		err_exit(server_fds[i] == -1, "socket() for listener sockets failed");
+
+		err = setsockopt(server_fds[i], SOL_SOCKET, SO_REUSEPORT,
+				 &optval, sizeof(optval));
+		err_exit(err == -1, "setsockopt() for SO_REUSEPORT failed");
+
+		if (i == 0) {
+			err = setsockopt(server_fds[i], SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF,
+					 &prog_fd, sizeof(prog_fd));
+			err_exit(err == -1, "setsockopt() for SO_ATTACH_REUSEPORT_EBPF failed");
+		}
+
+		err = bind(server_fds[i], (struct sockaddr *)&addr, addr_len);
+		err_exit(err == -1, "bind() failed");
+
+		err = listen(server_fds[i], 32);
+		err_exit(err == -1, "listen() failed");
+
+		err = bpf_map_update_elem(reuseport_map_fd, &i, &server_fds[i], BPF_NOEXIST);
+		err_exit(err == -1, "updating BPF reuseport_map failed");
+
+		err = bpf_map_lookup_elem(reuseport_map_fd, &i, &value);
+		err_exit(err == -1, "looking up BPF reuseport_map failed");
+
+		printf("fd[%d] (cookie: %llu) -> fd[%d]\n", i, value, migrated_to);
+		err = bpf_map_update_elem(migrate_map_fd, &value, &migrated_to, BPF_NOEXIST);
+		err_exit(err == -1, "updating BPF migrate_map failed");
+	}
+}
+
+void test_connect(void)
+{
+	struct sockaddr_in addr;
+	socklen_t addr_len = sizeof(addr);
+	int i, err, client_fd;
+
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(80);
+	inet_pton(AF_INET, LOCALHOST, &addr.sin_addr.s_addr);
+
+	for (i = 0; i < NUM_SOCKS * 5; i++) {
+		client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
+		err_exit(client_fd == -1, "socket() for listener sockets failed");
+
+		err = connect(client_fd, (struct sockaddr *)&addr, addr_len);
+		err_exit(err == -1, "connect() failed");
+
+		close(client_fd);
+	}
+}
+
+void test_close(void)
+{
+	int i;
+
+	for (i = 0; i < NUM_SOCKS - 1; i++)
+		close(server_fds[i]);
+}
+
+void test_accept(void)
+{
+	struct sockaddr_in addr;
+	socklen_t addr_len = sizeof(addr);
+	int cnt, client_fd;
+
+	fcntl(server_fds[NUM_SOCKS - 1], F_SETFL, O_NONBLOCK);
+
+	for (cnt = 0; cnt < NUM_SOCKS * 5; cnt++) {
+		client_fd = accept(server_fds[NUM_SOCKS - 1], (struct sockaddr *)&addr, &addr_len);
+		err_exit(client_fd == -1, "accept() failed");
+	}
+
+	printf("%d accepted, %d is expected\n", cnt, NUM_SOCKS * 5);
+}
+
+int main(void)
+{
+	setup_bpf();
+	test_listen();
+	test_connect();
+	test_close();
+	test_accept();
+	close(server_fds[NUM_SOCKS - 1]);
+	return 0;
+}
diff --git a/tools/testing/selftests/bpf/progs/test_migrate_reuseport_kern.c b/tools/testing/selftests/bpf/progs/test_migrate_reuseport_kern.c
new file mode 100644
index 000000000000..28d007b3a7a7
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_migrate_reuseport_kern.c
@@ -0,0 +1,54 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Check if we can migrate child sockets.
+ *
+ *   1. If reuse_md->migration is 0 (SYN packet),
+ *        return SK_PASS without selecting a listener.
+ *   2. If reuse_md->migration is not 0 (socket migration),
+ *        select a listener (reuseport_map[migrate_map[cookie]])
+ *
+ * Author: Kuniyuki Iwashima <kuniyu@amazon.co.jp>
+ */
+
+#include <linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define NULL ((void *)0)
+
+int _version SEC("version") = 1;
+
+struct bpf_map_def SEC("maps") reuseport_map = {
+	.type = BPF_MAP_TYPE_REUSEPORT_SOCKARRAY,
+	.key_size = sizeof(int),
+	.value_size = sizeof(__u64),
+	.max_entries = 256,
+};
+
+struct bpf_map_def SEC("maps") migrate_map = {
+	.type = BPF_MAP_TYPE_HASH,
+	.key_size = sizeof(__u64),
+	.value_size = sizeof(int),
+	.max_entries = 256,
+};
+
+SEC("sk_reuseport/migrate")
+int select_by_skb_data(struct sk_reuseport_md *reuse_md)
+{
+	int *key, flags = 0;
+	__u64 cookie;
+
+	if (!reuse_md->migration)
+		return SK_PASS;
+
+	cookie = bpf_get_socket_cookie(reuse_md->sk);
+
+	key = bpf_map_lookup_elem(&migrate_map, &cookie);
+	if (key == NULL)
+		return SK_DROP;
+
+	bpf_sk_select_reuseport(reuse_md, &reuseport_map, key, flags);
+
+	return SK_PASS;
+}
+
+char _license[] SEC("license") = "GPL";