selftests/bpf: bpf_setsockopt tests
authorMartin KaFai Lau <kafai@fb.com>
Wed, 17 Aug 2022 06:18:47 +0000 (23:18 -0700)
committerAlexei Starovoitov <ast@kernel.org>
Fri, 19 Aug 2022 00:06:14 +0000 (17:06 -0700)
This patch adds tests to exercise optnames that are allowed
in bpf_setsockopt().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061847.4182339-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
tools/testing/selftests/bpf/prog_tests/setget_sockopt.c [new file with mode: 0644]
tools/testing/selftests/bpf/progs/bpf_tracing_net.h
tools/testing/selftests/bpf/progs/setget_sockopt.c [new file with mode: 0644]

diff --git a/tools/testing/selftests/bpf/prog_tests/setget_sockopt.c b/tools/testing/selftests/bpf/prog_tests/setget_sockopt.c
new file mode 100644 (file)
index 0000000..018611e
--- /dev/null
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#define _GNU_SOURCE
+#include <sched.h>
+#include <linux/socket.h>
+#include <net/if.h>
+
+#include "test_progs.h"
+#include "cgroup_helpers.h"
+#include "network_helpers.h"
+
+#include "setget_sockopt.skel.h"
+
+#define CG_NAME "/setget-sockopt-test"
+
+static const char addr4_str[] = "127.0.0.1";
+static const char addr6_str[] = "::1";
+static struct setget_sockopt *skel;
+static int cg_fd;
+
+static int create_netns(void)
+{
+       if (!ASSERT_OK(unshare(CLONE_NEWNET), "create netns"))
+               return -1;
+
+       if (!ASSERT_OK(system("ip link set dev lo up"), "set lo up"))
+               return -1;
+
+       if (!ASSERT_OK(system("ip link add dev binddevtest1 type veth peer name binddevtest2"),
+                      "add veth"))
+               return -1;
+
+       if (!ASSERT_OK(system("ip link set dev binddevtest1 up"),
+                      "bring veth up"))
+               return -1;
+
+       return 0;
+}
+
+static void test_tcp(int family)
+{
+       struct setget_sockopt__bss *bss = skel->bss;
+       int sfd, cfd;
+
+       memset(bss, 0, sizeof(*bss));
+
+       sfd = start_server(family, SOCK_STREAM,
+                          family == AF_INET6 ? addr6_str : addr4_str, 0, 0);
+       if (!ASSERT_GE(sfd, 0, "start_server"))
+               return;
+
+       cfd = connect_to_fd(sfd, 0);
+       if (!ASSERT_GE(cfd, 0, "connect_to_fd_server")) {
+               close(sfd);
+               return;
+       }
+       close(sfd);
+       close(cfd);
+
+       ASSERT_EQ(bss->nr_listen, 1, "nr_listen");
+       ASSERT_EQ(bss->nr_connect, 1, "nr_connect");
+       ASSERT_EQ(bss->nr_active, 1, "nr_active");
+       ASSERT_EQ(bss->nr_passive, 1, "nr_passive");
+       ASSERT_EQ(bss->nr_socket_post_create, 2, "nr_socket_post_create");
+       ASSERT_EQ(bss->nr_binddev, 2, "nr_bind");
+}
+
+static void test_udp(int family)
+{
+       struct setget_sockopt__bss *bss = skel->bss;
+       int sfd;
+
+       memset(bss, 0, sizeof(*bss));
+
+       sfd = start_server(family, SOCK_DGRAM,
+                          family == AF_INET6 ? addr6_str : addr4_str, 0, 0);
+       if (!ASSERT_GE(sfd, 0, "start_server"))
+               return;
+       close(sfd);
+
+       ASSERT_GE(bss->nr_socket_post_create, 1, "nr_socket_post_create");
+       ASSERT_EQ(bss->nr_binddev, 1, "nr_bind");
+}
+
+void test_setget_sockopt(void)
+{
+       cg_fd = test__join_cgroup(CG_NAME);
+       if (cg_fd < 0)
+               return;
+
+       if (create_netns())
+               goto done;
+
+       skel = setget_sockopt__open();
+       if (!ASSERT_OK_PTR(skel, "open skel"))
+               goto done;
+
+       strcpy(skel->rodata->veth, "binddevtest1");
+       skel->rodata->veth_ifindex = if_nametoindex("binddevtest1");
+       if (!ASSERT_GT(skel->rodata->veth_ifindex, 0, "if_nametoindex"))
+               goto done;
+
+       if (!ASSERT_OK(setget_sockopt__load(skel), "load skel"))
+               goto done;
+
+       skel->links.skops_sockopt =
+               bpf_program__attach_cgroup(skel->progs.skops_sockopt, cg_fd);
+       if (!ASSERT_OK_PTR(skel->links.skops_sockopt, "attach cgroup"))
+               goto done;
+
+       skel->links.socket_post_create =
+               bpf_program__attach_cgroup(skel->progs.socket_post_create, cg_fd);
+       if (!ASSERT_OK_PTR(skel->links.socket_post_create, "attach_cgroup"))
+               goto done;
+
+       test_tcp(AF_INET6);
+       test_tcp(AF_INET);
+       test_udp(AF_INET6);
+       test_udp(AF_INET);
+
+done:
+       setget_sockopt__destroy(skel);
+       close(cg_fd);
+}
index 98dd2c4..5ebc6da 100644 (file)
@@ -6,13 +6,40 @@
 #define AF_INET6               10
 
 #define SOL_SOCKET             1
+#define SO_REUSEADDR           2
 #define SO_SNDBUF              7
-#define __SO_ACCEPTCON         (1 << 16)
+#define SO_RCVBUF              8
+#define SO_KEEPALIVE           9
 #define SO_PRIORITY            12
+#define SO_REUSEPORT           15
+#define SO_RCVLOWAT            18
+#define SO_BINDTODEVICE                25
+#define SO_MARK                        36
+#define SO_MAX_PACING_RATE     47
+#define SO_BINDTOIFINDEX       62
+#define SO_TXREHASH            74
+#define __SO_ACCEPTCON         (1 << 16)
+
+#define IP_TOS                 1
+
+#define IPV6_TCLASS            67
+#define IPV6_AUTOFLOWLABEL     70
 
 #define SOL_TCP                        6
+#define TCP_NODELAY            1
+#define TCP_MAXSEG             2
+#define TCP_KEEPIDLE           4
+#define TCP_KEEPINTVL          5
+#define TCP_KEEPCNT            6
+#define TCP_SYNCNT             7
+#define TCP_WINDOW_CLAMP       10
 #define TCP_CONGESTION         13
+#define TCP_THIN_LINEAR_TIMEOUTS       16
+#define TCP_USER_TIMEOUT       18
+#define TCP_NOTSENT_LOWAT      25
+#define TCP_SAVE_SYN           27
 #define TCP_CA_NAME_MAX                16
+#define TCP_NAGLE_OFF          1
 
 #define ICSK_TIME_RETRANS      1
 #define ICSK_TIME_PROBE0       3
@@ -49,6 +76,8 @@
 #define sk_state               __sk_common.skc_state
 #define sk_v6_daddr            __sk_common.skc_v6_daddr
 #define sk_v6_rcv_saddr                __sk_common.skc_v6_rcv_saddr
+#define sk_flags               __sk_common.skc_flags
+#define sk_reuse               __sk_common.skc_reuse
 
 #define s6_addr32              in6_u.u6_addr32
 
diff --git a/tools/testing/selftests/bpf/progs/setget_sockopt.c b/tools/testing/selftests/bpf/progs/setget_sockopt.c
new file mode 100644 (file)
index 0000000..4a4cb44
--- /dev/null
@@ -0,0 +1,451 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include "bpf_tracing_net.h"
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+extern unsigned long CONFIG_HZ __kconfig;
+
+const volatile char veth[IFNAMSIZ];
+const volatile int veth_ifindex;
+
+int nr_listen;
+int nr_passive;
+int nr_active;
+int nr_connect;
+int nr_binddev;
+int nr_socket_post_create;
+
+struct sockopt_test {
+       int opt;
+       int new;
+       int restore;
+       int expected;
+       int tcp_expected;
+       unsigned int flip:1;
+};
+
+static const char cubic_cc[] = "cubic";
+static const char reno_cc[] = "reno";
+
+static const struct sockopt_test sol_socket_tests[] = {
+       { .opt = SO_REUSEADDR, .flip = 1, },
+       { .opt = SO_SNDBUF, .new = 8123, .expected = 8123 * 2, },
+       { .opt = SO_RCVBUF, .new = 8123, .expected = 8123 * 2, },
+       { .opt = SO_KEEPALIVE, .flip = 1, },
+       { .opt = SO_PRIORITY, .new = 0xeb9f, .expected = 0xeb9f, },
+       { .opt = SO_REUSEPORT, .flip = 1, },
+       { .opt = SO_RCVLOWAT, .new = 8123, .expected = 8123, },
+       { .opt = SO_MARK, .new = 0xeb9f, .expected = 0xeb9f, },
+       { .opt = SO_MAX_PACING_RATE, .new = 0xeb9f, .expected = 0xeb9f, },
+       { .opt = SO_TXREHASH, .flip = 1, },
+       { .opt = 0, },
+};
+
+static const struct sockopt_test sol_tcp_tests[] = {
+       { .opt = TCP_NODELAY, .flip = 1, },
+       { .opt = TCP_MAXSEG, .new = 1314, .expected = 1314, },
+       { .opt = TCP_KEEPIDLE, .new = 123, .expected = 123, .restore = 321, },
+       { .opt = TCP_KEEPINTVL, .new = 123, .expected = 123, .restore = 321, },
+       { .opt = TCP_KEEPCNT, .new = 123, .expected = 123, .restore = 124, },
+       { .opt = TCP_SYNCNT, .new = 123, .expected = 123, .restore = 124, },
+       { .opt = TCP_WINDOW_CLAMP, .new = 8123, .expected = 8123, .restore = 8124, },
+       { .opt = TCP_CONGESTION, },
+       { .opt = TCP_THIN_LINEAR_TIMEOUTS, .flip = 1, },
+       { .opt = TCP_USER_TIMEOUT, .new = 123400, .expected = 123400, },
+       { .opt = TCP_NOTSENT_LOWAT, .new = 1314, .expected = 1314, },
+       { .opt = TCP_SAVE_SYN, .new = 1, .expected = 1, },
+       { .opt = 0, },
+};
+
+static const struct sockopt_test sol_ip_tests[] = {
+       { .opt = IP_TOS, .new = 0xe1, .expected = 0xe1, .tcp_expected = 0xe0, },
+       { .opt = 0, },
+};
+
+static const struct sockopt_test sol_ipv6_tests[] = {
+       { .opt = IPV6_TCLASS, .new = 0xe1, .expected = 0xe1, .tcp_expected = 0xe0, },
+       { .opt = IPV6_AUTOFLOWLABEL, .flip = 1, },
+       { .opt = 0, },
+};
+
+struct loop_ctx {
+       void *ctx;
+       struct sock *sk;
+};
+
+static int __bpf_getsockopt(void *ctx, struct sock *sk,
+                           int level, int opt, int *optval,
+                           int optlen)
+{
+       if (level == SOL_SOCKET) {
+               switch (opt) {
+               case SO_REUSEADDR:
+                       *optval = !!BPF_CORE_READ_BITFIELD(sk, sk_reuse);
+                       break;
+               case SO_KEEPALIVE:
+                       *optval = !!(sk->sk_flags & (1UL << 3));
+                       break;
+               case SO_RCVLOWAT:
+                       *optval = sk->sk_rcvlowat;
+                       break;
+               case SO_MAX_PACING_RATE:
+                       *optval = sk->sk_max_pacing_rate;
+                       break;
+               default:
+                       return bpf_getsockopt(ctx, level, opt, optval, optlen);
+               }
+               return 0;
+       }
+
+       if (level == IPPROTO_TCP) {
+               struct tcp_sock *tp = bpf_skc_to_tcp_sock(sk);
+
+               if (!tp)
+                       return -1;
+
+               switch (opt) {
+               case TCP_NODELAY:
+                       *optval = !!(BPF_CORE_READ_BITFIELD(tp, nonagle) & TCP_NAGLE_OFF);
+                       break;
+               case TCP_MAXSEG:
+                       *optval = tp->rx_opt.user_mss;
+                       break;
+               case TCP_KEEPIDLE:
+                       *optval = tp->keepalive_time / CONFIG_HZ;
+                       break;
+               case TCP_SYNCNT:
+                       *optval = tp->inet_conn.icsk_syn_retries;
+                       break;
+               case TCP_KEEPINTVL:
+                       *optval = tp->keepalive_intvl / CONFIG_HZ;
+                       break;
+               case TCP_KEEPCNT:
+                       *optval = tp->keepalive_probes;
+                       break;
+               case TCP_WINDOW_CLAMP:
+                       *optval = tp->window_clamp;
+                       break;
+               case TCP_THIN_LINEAR_TIMEOUTS:
+                       *optval = !!BPF_CORE_READ_BITFIELD(tp, thin_lto);
+                       break;
+               case TCP_USER_TIMEOUT:
+                       *optval = tp->inet_conn.icsk_user_timeout;
+                       break;
+               case TCP_NOTSENT_LOWAT:
+                       *optval = tp->notsent_lowat;
+                       break;
+               case TCP_SAVE_SYN:
+                       *optval = BPF_CORE_READ_BITFIELD(tp, save_syn);
+                       break;
+               default:
+                       return bpf_getsockopt(ctx, level, opt, optval, optlen);
+               }
+               return 0;
+       }
+
+       if (level == IPPROTO_IPV6) {
+               switch (opt) {
+               case IPV6_AUTOFLOWLABEL: {
+                       __u16 proto = sk->sk_protocol;
+                       struct inet_sock *inet_sk;
+
+                       if (proto == IPPROTO_TCP)
+                               inet_sk = (struct inet_sock *)bpf_skc_to_tcp_sock(sk);
+                       else
+                               inet_sk = (struct inet_sock *)bpf_skc_to_udp6_sock(sk);
+
+                       if (!inet_sk)
+                               return -1;
+
+                       *optval = !!inet_sk->pinet6->autoflowlabel;
+                       break;
+               }
+               default:
+                       return bpf_getsockopt(ctx, level, opt, optval, optlen);
+               }
+               return 0;
+       }
+
+       return bpf_getsockopt(ctx, level, opt, optval, optlen);
+}
+
+static int bpf_test_sockopt_flip(void *ctx, struct sock *sk,
+                                const struct sockopt_test *t,
+                                int level)
+{
+       int old, tmp, new, opt = t->opt;
+
+       opt = t->opt;
+
+       if (__bpf_getsockopt(ctx, sk, level, opt, &old, sizeof(old)))
+               return 1;
+       /* kernel initialized txrehash to 255 */
+       if (level == SOL_SOCKET && opt == SO_TXREHASH && old != 0 && old != 1)
+               old = 1;
+
+       new = !old;
+       if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)))
+               return 1;
+       if (__bpf_getsockopt(ctx, sk, level, opt, &tmp, sizeof(tmp)) ||
+           tmp != new)
+               return 1;
+
+       if (bpf_setsockopt(ctx, level, opt, &old, sizeof(old)))
+               return 1;
+
+       return 0;
+}
+
+static int bpf_test_sockopt_int(void *ctx, struct sock *sk,
+                               const struct sockopt_test *t,
+                               int level)
+{
+       int old, tmp, new, expected, opt;
+
+       opt = t->opt;
+       new = t->new;
+       if (sk->sk_type == SOCK_STREAM && t->tcp_expected)
+               expected = t->tcp_expected;
+       else
+               expected = t->expected;
+
+       if (__bpf_getsockopt(ctx, sk, level, opt, &old, sizeof(old)) ||
+           old == new)
+               return 1;
+
+       if (bpf_setsockopt(ctx, level, opt, &new, sizeof(new)))
+               return 1;
+       if (__bpf_getsockopt(ctx, sk, level, opt, &tmp, sizeof(tmp)) ||
+           tmp != expected)
+               return 1;
+
+       if (t->restore)
+               old = t->restore;
+       if (bpf_setsockopt(ctx, level, opt, &old, sizeof(old)))
+               return 1;
+
+       return 0;
+}
+
+static int bpf_test_socket_sockopt(__u32 i, struct loop_ctx *lc)
+{
+       const struct sockopt_test *t;
+
+       if (i >= ARRAY_SIZE(sol_socket_tests))
+               return 1;
+
+       t = &sol_socket_tests[i];
+       if (!t->opt)
+               return 1;
+
+       if (t->flip)
+               return bpf_test_sockopt_flip(lc->ctx, lc->sk, t, SOL_SOCKET);
+
+       return bpf_test_sockopt_int(lc->ctx, lc->sk, t, SOL_SOCKET);
+}
+
+static int bpf_test_ip_sockopt(__u32 i, struct loop_ctx *lc)
+{
+       const struct sockopt_test *t;
+
+       if (i >= ARRAY_SIZE(sol_ip_tests))
+               return 1;
+
+       t = &sol_ip_tests[i];
+       if (!t->opt)
+               return 1;
+
+       if (t->flip)
+               return bpf_test_sockopt_flip(lc->ctx, lc->sk, t, IPPROTO_IP);
+
+       return bpf_test_sockopt_int(lc->ctx, lc->sk, t, IPPROTO_IP);
+}
+
+static int bpf_test_ipv6_sockopt(__u32 i, struct loop_ctx *lc)
+{
+       const struct sockopt_test *t;
+
+       if (i >= ARRAY_SIZE(sol_ipv6_tests))
+               return 1;
+
+       t = &sol_ipv6_tests[i];
+       if (!t->opt)
+               return 1;
+
+       if (t->flip)
+               return bpf_test_sockopt_flip(lc->ctx, lc->sk, t, IPPROTO_IPV6);
+
+       return bpf_test_sockopt_int(lc->ctx, lc->sk, t, IPPROTO_IPV6);
+}
+
+static int bpf_test_tcp_sockopt(__u32 i, struct loop_ctx *lc)
+{
+       const struct sockopt_test *t;
+       struct sock *sk;
+       void *ctx;
+
+       if (i >= ARRAY_SIZE(sol_tcp_tests))
+               return 1;
+
+       t = &sol_tcp_tests[i];
+       if (!t->opt)
+               return 1;
+
+       ctx = lc->ctx;
+       sk = lc->sk;
+
+       if (t->opt == TCP_CONGESTION) {
+               char old_cc[16], tmp_cc[16];
+               const char *new_cc;
+
+               if (bpf_getsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, old_cc, sizeof(old_cc)))
+                       return 1;
+               if (!bpf_strncmp(old_cc, sizeof(old_cc), cubic_cc))
+                       new_cc = reno_cc;
+               else
+                       new_cc = cubic_cc;
+               if (bpf_setsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, (void *)new_cc,
+                                  sizeof(new_cc)))
+                       return 1;
+               if (bpf_getsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, tmp_cc, sizeof(tmp_cc)))
+                       return 1;
+               if (bpf_strncmp(tmp_cc, sizeof(tmp_cc), new_cc))
+                       return 1;
+               if (bpf_setsockopt(ctx, IPPROTO_TCP, TCP_CONGESTION, old_cc, sizeof(old_cc)))
+                       return 1;
+               return 0;
+       }
+
+       if (t->flip)
+               return bpf_test_sockopt_flip(ctx, sk, t, IPPROTO_TCP);
+
+       return bpf_test_sockopt_int(ctx, sk, t, IPPROTO_TCP);
+}
+
+static int bpf_test_sockopt(void *ctx, struct sock *sk)
+{
+       struct loop_ctx lc = { .ctx = ctx, .sk = sk, };
+       __u16 family, proto;
+       int n;
+
+       family = sk->sk_family;
+       proto = sk->sk_protocol;
+
+       n = bpf_loop(ARRAY_SIZE(sol_socket_tests), bpf_test_socket_sockopt, &lc, 0);
+       if (n != ARRAY_SIZE(sol_socket_tests))
+               return -1;
+
+       if (proto == IPPROTO_TCP) {
+               n = bpf_loop(ARRAY_SIZE(sol_tcp_tests), bpf_test_tcp_sockopt, &lc, 0);
+               if (n != ARRAY_SIZE(sol_tcp_tests))
+                       return -1;
+       }
+
+       if (family == AF_INET) {
+               n = bpf_loop(ARRAY_SIZE(sol_ip_tests), bpf_test_ip_sockopt, &lc, 0);
+               if (n != ARRAY_SIZE(sol_ip_tests))
+                       return -1;
+       } else {
+               n = bpf_loop(ARRAY_SIZE(sol_ipv6_tests), bpf_test_ipv6_sockopt, &lc, 0);
+               if (n != ARRAY_SIZE(sol_ipv6_tests))
+                       return -1;
+       }
+
+       return 0;
+}
+
+static int binddev_test(void *ctx)
+{
+       const char empty_ifname[] = "";
+       int ifindex, zero = 0;
+
+       if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+                          (void *)veth, sizeof(veth)))
+               return -1;
+       if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+                          &ifindex, sizeof(int)) ||
+           ifindex != veth_ifindex)
+               return -1;
+
+       if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTODEVICE,
+                          (void *)empty_ifname, sizeof(empty_ifname)))
+               return -1;
+       if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+                          &ifindex, sizeof(int)) ||
+           ifindex != 0)
+               return -1;
+
+       if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+                          (void *)&veth_ifindex, sizeof(int)))
+               return -1;
+       if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+                          &ifindex, sizeof(int)) ||
+           ifindex != veth_ifindex)
+               return -1;
+
+       if (bpf_setsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+                          &zero, sizeof(int)))
+               return -1;
+       if (bpf_getsockopt(ctx, SOL_SOCKET, SO_BINDTOIFINDEX,
+                          &ifindex, sizeof(int)) ||
+           ifindex != 0)
+               return -1;
+
+       return 0;
+}
+
+SEC("lsm_cgroup/socket_post_create")
+int BPF_PROG(socket_post_create, struct socket *sock, int family,
+            int type, int protocol, int kern)
+{
+       struct sock *sk = sock->sk;
+
+       if (!sk)
+               return 1;
+
+       nr_socket_post_create += !bpf_test_sockopt(sk, sk);
+       nr_binddev += !binddev_test(sk);
+
+       return 1;
+}
+
+SEC("sockops")
+int skops_sockopt(struct bpf_sock_ops *skops)
+{
+       struct bpf_sock *bpf_sk = skops->sk;
+       struct sock *sk;
+
+       if (!bpf_sk)
+               return 1;
+
+       sk = (struct sock *)bpf_skc_to_tcp_sock(bpf_sk);
+       if (!sk)
+               return 1;
+
+       switch (skops->op) {
+       case BPF_SOCK_OPS_TCP_LISTEN_CB:
+               nr_listen += !bpf_test_sockopt(skops, sk);
+               break;
+       case BPF_SOCK_OPS_TCP_CONNECT_CB:
+               nr_connect += !bpf_test_sockopt(skops, sk);
+               break;
+       case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+               nr_active += !bpf_test_sockopt(skops, sk);
+               break;
+       case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+               nr_passive += !bpf_test_sockopt(skops, sk);
+               break;
+       }
+
+       return 1;
+}
+
+char _license[] SEC("license") = "GPL";