This patch adds a test for net.ipv4.tcp_migrate_req with eBPF.
Reviewed-by: Benjamin Herrenschmidt <benh@xxxxxxxxxx>
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx>
---
.../bpf/prog_tests/migrate_reuseport.c | 175 ++++++++++++++++++
.../bpf/progs/test_migrate_reuseport_kern.c | 53 ++++++
2 files changed, 228 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..fb182e575371
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/migrate_reuseport.c
@@ -0,0 +1,175 @@
+// 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 (map[cookie] = 4)
+ * 3. call connect() for 25 client sockets.
+ * 4. call close() first 4 server sockets.
+ * 5. call receive() for the last server socket.
+ *
+ * Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx>
+ */
+
+#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 " "); \
+ setup_sysctl(0); \
+ exit(1); \
+ } \
+ } while (0)
+
+__u64 server_fds[NUM_SOCKS];
+int prog_fd, map_fd, migrate_map_fd;
+
+void setup_sysctl(int value)
+{
+ FILE *file;
+
+ file = fopen("/proc/sys/net/ipv4/tcp_migrate_req", "w");
+ fprintf(file, "%d", value);
+ fclose(file);
+}
+
+void setup_bpf(void)
+{
+ struct bpf_object *obj;
+ struct bpf_program *prog;
+ struct bpf_map *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");
+
+ map = bpf_object__find_map_by_name(obj, "reuseport_map");
+ err_exit(!map, "loading BPF reuseport_map failed");
+
+ migrate_map = bpf_object__find_map_by_name(obj, "migrate_map");
+ err_exit(!map, "loading BPF migrate_map failed");
+
+ prog_fd = bpf_program__fd(prog);
+ map_fd = bpf_map__fd(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(map_fd, &i, &server_fds[i], BPF_NOEXIST);
+ err_exit(err == -1, "updating BPF reuseport_map failed");
+
+ err = bpf_map_lookup_elem(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_receive(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_sysctl(1);
+ setup_bpf();
+ test_listen();
+ test_connect();
+ test_close();
+ test_receive();
+ close(server_fds[NUM_SOCKS - 1]);
+ setup_sysctl(0);
+ 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..79f8a3465c20
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_migrate_reuseport_kern.c
@@ -0,0 +1,53 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Check if we can migrate child sockets.
+ *
+ * 1. If data is not NULL (SYN packet),
+ * return SK_PASS without selecting a listener.
+ * 2. If data is NULL (socket migration),
+ * select a listener (reuseport_map[map[cookie]])
+ *
+ * Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx>
+ */
+
+#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")
+int select_by_skb_data(struct sk_reuseport_md *reuse_md)
+{
+ int *key, flags = 0;
+ void *data = reuse_md->data;
+ __u64 cookie = reuse_md->cookie;
+
+ if (data)
+ return SK_PASS;
+
+ 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";
--
2.17.2 (Apple Git-113)
