1 files changed, 678 insertions, 0 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c
new file mode 100644
index 000000000..172c586b6
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector_reattach.c
@@ -0,0 +1,678 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Tests for attaching, detaching, and replacing flow_dissector BPF program.
+ */
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+
+#include "test_progs.h"
+
+static int init_net = -1;
+
+static __u32 query_attached_prog_id(int netns)
+{
+	__u32 prog_ids[1] = {};
+	__u32 prog_cnt = ARRAY_SIZE(prog_ids);
+	int err;
+
+	err = bpf_prog_query(netns, BPF_FLOW_DISSECTOR, 0, NULL,
+			     prog_ids, &prog_cnt);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_prog_query");
+		return 0;
+	}
+
+	return prog_cnt == 1 ? prog_ids[0] : 0;
+}
+
+static bool prog_is_attached(int netns)
+{
+	return query_attached_prog_id(netns) > 0;
+}
+
+static int load_prog(enum bpf_prog_type type)
+{
+	struct bpf_insn prog[] = {
+		BPF_MOV64_IMM(BPF_REG_0, BPF_OK),
+		BPF_EXIT_INSN(),
+	};
+	int fd;
+
+	fd = bpf_load_program(type, prog, ARRAY_SIZE(prog), "GPL", 0, NULL, 0);
+	if (CHECK_FAIL(fd < 0))
+		perror("bpf_load_program");
+
+	return fd;
+}
+
+static __u32 query_prog_id(int prog)
+{
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	int err;
+
+	err = bpf_obj_get_info_by_fd(prog, &info, &info_len);
+	if (CHECK_FAIL(err || info_len != sizeof(info))) {
+		perror("bpf_obj_get_info_by_fd");
+		return 0;
+	}
+
+	return info.id;
+}
+
+static int unshare_net(int old_net)
+{
+	int err, new_net;
+
+	err = unshare(CLONE_NEWNET);
+	if (CHECK_FAIL(err)) {
+		perror("unshare(CLONE_NEWNET)");
+		return -1;
+	}
+	new_net = open("/proc/self/ns/net", O_RDONLY);
+	if (CHECK_FAIL(new_net < 0)) {
+		perror("open(/proc/self/ns/net)");
+		setns(old_net, CLONE_NEWNET);
+		return -1;
+	}
+	return new_net;
+}
+
+static void test_prog_attach_prog_attach(int netns, int prog1, int prog2)
+{
+	int err;
+
+	err = bpf_prog_attach(prog1, 0, BPF_FLOW_DISSECTOR, 0);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_prog_attach(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect success when attaching a different program */
+	err = bpf_prog_attach(prog2, 0, BPF_FLOW_DISSECTOR, 0);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_prog_attach(prog2) #1");
+		goto out_detach;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog2));
+
+	/* Expect failure when attaching the same program twice */
+	err = bpf_prog_attach(prog2, 0, BPF_FLOW_DISSECTOR, 0);
+	if (CHECK_FAIL(!err || errno != EINVAL))
+		perror("bpf_prog_attach(prog2) #2");
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog2));
+
+out_detach:
+	err = bpf_prog_detach2(prog2, 0, BPF_FLOW_DISSECTOR);
+	if (CHECK_FAIL(err))
+		perror("bpf_prog_detach");
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_create_link_create(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts);
+	int link1, link2;
+
+	link1 = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect failure creating link when another link exists */
+	errno = 0;
+	link2 = bpf_link_create(prog2, netns, BPF_FLOW_DISSECTOR, &opts);
+	if (CHECK_FAIL(link2 != -1 || errno != E2BIG))
+		perror("bpf_prog_attach(prog2) expected E2BIG");
+	if (link2 != -1)
+		close(link2);
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	close(link1);
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_prog_attach_link_create(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts);
+	int err, link;
+
+	err = bpf_prog_attach(prog1, 0, BPF_FLOW_DISSECTOR, 0);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_prog_attach(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect failure creating link when prog attached */
+	errno = 0;
+	link = bpf_link_create(prog2, netns, BPF_FLOW_DISSECTOR, &opts);
+	if (CHECK_FAIL(link != -1 || errno != EEXIST))
+		perror("bpf_link_create(prog2) expected EEXIST");
+	if (link != -1)
+		close(link);
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	err = bpf_prog_detach2(prog1, 0, BPF_FLOW_DISSECTOR);
+	if (CHECK_FAIL(err))
+		perror("bpf_prog_detach");
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_create_prog_attach(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts);
+	int err, link;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect failure attaching prog when link exists */
+	errno = 0;
+	err = bpf_prog_attach(prog2, 0, BPF_FLOW_DISSECTOR, 0);
+	if (CHECK_FAIL(!err || errno != EEXIST))
+		perror("bpf_prog_attach(prog2) expected EEXIST");
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	close(link);
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_create_prog_detach(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts);
+	int err, link;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect failure detaching prog when link exists */
+	errno = 0;
+	err = bpf_prog_detach2(prog1, 0, BPF_FLOW_DISSECTOR);
+	if (CHECK_FAIL(!err || errno != EINVAL))
+		perror("bpf_prog_detach expected EINVAL");
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	close(link);
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_prog_attach_detach_query(int netns, int prog1, int prog2)
+{
+	int err;
+
+	err = bpf_prog_attach(prog1, 0, BPF_FLOW_DISSECTOR, 0);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_prog_attach(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	err = bpf_prog_detach2(prog1, 0, BPF_FLOW_DISSECTOR);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_prog_detach");
+		return;
+	}
+
+	/* Expect no prog attached after successful detach */
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_create_close_query(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, opts);
+	int link;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	close(link);
+	/* Expect no prog attached after closing last link FD */
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_update_no_old_prog(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts);
+	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts);
+	int err, link;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &create_opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect success replacing the prog when old prog not specified */
+	update_opts.flags = 0;
+	update_opts.old_prog_fd = 0;
+	err = bpf_link_update(link, prog2, &update_opts);
+	if (CHECK_FAIL(err))
+		perror("bpf_link_update");
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog2));
+
+	close(link);
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_update_replace_old_prog(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts);
+	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts);
+	int err, link;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &create_opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect success F_REPLACE and old prog specified to succeed */
+	update_opts.flags = BPF_F_REPLACE;
+	update_opts.old_prog_fd = prog1;
+	err = bpf_link_update(link, prog2, &update_opts);
+	if (CHECK_FAIL(err))
+		perror("bpf_link_update");
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog2));
+
+	close(link);
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_update_same_prog(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts);
+	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts);
+	int err, link;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &create_opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect success updating the prog with the same one */
+	update_opts.flags = 0;
+	update_opts.old_prog_fd = 0;
+	err = bpf_link_update(link, prog1, &update_opts);
+	if (CHECK_FAIL(err))
+		perror("bpf_link_update");
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	close(link);
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_update_invalid_opts(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts);
+	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts);
+	int err, link;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &create_opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect update to fail w/ old prog FD but w/o F_REPLACE*/
+	errno = 0;
+	update_opts.flags = 0;
+	update_opts.old_prog_fd = prog1;
+	err = bpf_link_update(link, prog2, &update_opts);
+	if (CHECK_FAIL(!err || errno != EINVAL)) {
+		perror("bpf_link_update expected EINVAL");
+		goto out_close;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect update to fail on old prog FD mismatch */
+	errno = 0;
+	update_opts.flags = BPF_F_REPLACE;
+	update_opts.old_prog_fd = prog2;
+	err = bpf_link_update(link, prog2, &update_opts);
+	if (CHECK_FAIL(!err || errno != EPERM)) {
+		perror("bpf_link_update expected EPERM");
+		goto out_close;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect update to fail for invalid old prog FD */
+	errno = 0;
+	update_opts.flags = BPF_F_REPLACE;
+	update_opts.old_prog_fd = -1;
+	err = bpf_link_update(link, prog2, &update_opts);
+	if (CHECK_FAIL(!err || errno != EBADF)) {
+		perror("bpf_link_update expected EBADF");
+		goto out_close;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect update to fail with invalid flags */
+	errno = 0;
+	update_opts.flags = BPF_F_ALLOW_MULTI;
+	update_opts.old_prog_fd = 0;
+	err = bpf_link_update(link, prog2, &update_opts);
+	if (CHECK_FAIL(!err || errno != EINVAL))
+		perror("bpf_link_update expected EINVAL");
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+out_close:
+	close(link);
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_update_invalid_prog(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts);
+	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts);
+	int err, link, prog3;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &create_opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	/* Expect failure when new prog FD is not valid */
+	errno = 0;
+	update_opts.flags = 0;
+	update_opts.old_prog_fd = 0;
+	err = bpf_link_update(link, -1, &update_opts);
+	if (CHECK_FAIL(!err || errno != EBADF)) {
+		perror("bpf_link_update expected EINVAL");
+		goto out_close_link;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	prog3 = load_prog(BPF_PROG_TYPE_SOCKET_FILTER);
+	if (prog3 < 0)
+		goto out_close_link;
+
+	/* Expect failure when new prog FD type doesn't match */
+	errno = 0;
+	update_opts.flags = 0;
+	update_opts.old_prog_fd = 0;
+	err = bpf_link_update(link, prog3, &update_opts);
+	if (CHECK_FAIL(!err || errno != EINVAL))
+		perror("bpf_link_update expected EINVAL");
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	close(prog3);
+out_close_link:
+	close(link);
+	CHECK_FAIL(prog_is_attached(netns));
+}
+
+static void test_link_update_netns_gone(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts);
+	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts);
+	int err, link, old_net;
+
+	old_net = netns;
+	netns = unshare_net(old_net);
+	if (netns < 0)
+		return;
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &create_opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		return;
+	}
+	CHECK_FAIL(query_attached_prog_id(netns) != query_prog_id(prog1));
+
+	close(netns);
+	err = setns(old_net, CLONE_NEWNET);
+	if (CHECK_FAIL(err)) {
+		perror("setns(CLONE_NEWNET)");
+		close(link);
+		return;
+	}
+
+	/* Expect failure when netns destroyed */
+	errno = 0;
+	update_opts.flags = 0;
+	update_opts.old_prog_fd = 0;
+	err = bpf_link_update(link, prog2, &update_opts);
+	if (CHECK_FAIL(!err || errno != ENOLINK))
+		perror("bpf_link_update");
+
+	close(link);
+}
+
+static void test_link_get_info(int netns, int prog1, int prog2)
+{
+	DECLARE_LIBBPF_OPTS(bpf_link_create_opts, create_opts);
+	DECLARE_LIBBPF_OPTS(bpf_link_update_opts, update_opts);
+	struct bpf_link_info info = {};
+	struct stat netns_stat = {};
+	__u32 info_len, link_id;
+	int err, link, old_net;
+
+	old_net = netns;
+	netns = unshare_net(old_net);
+	if (netns < 0)
+		return;
+
+	err = fstat(netns, &netns_stat);
+	if (CHECK_FAIL(err)) {
+		perror("stat(netns)");
+		goto out_resetns;
+	}
+
+	link = bpf_link_create(prog1, netns, BPF_FLOW_DISSECTOR, &create_opts);
+	if (CHECK_FAIL(link < 0)) {
+		perror("bpf_link_create(prog1)");
+		goto out_resetns;
+	}
+
+	info_len = sizeof(info);
+	err = bpf_obj_get_info_by_fd(link, &info, &info_len);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_obj_get_info");
+		goto out_unlink;
+	}
+	CHECK_FAIL(info_len != sizeof(info));
+
+	/* Expect link info to be sane and match prog and netns details */
+	CHECK_FAIL(info.type != BPF_LINK_TYPE_NETNS);
+	CHECK_FAIL(info.id == 0);
+	CHECK_FAIL(info.prog_id != query_prog_id(prog1));
+	CHECK_FAIL(info.netns.netns_ino != netns_stat.st_ino);
+	CHECK_FAIL(info.netns.attach_type != BPF_FLOW_DISSECTOR);
+
+	update_opts.flags = 0;
+	update_opts.old_prog_fd = 0;
+	err = bpf_link_update(link, prog2, &update_opts);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_link_update(prog2)");
+		goto out_unlink;
+	}
+
+	link_id = info.id;
+	info_len = sizeof(info);
+	err = bpf_obj_get_info_by_fd(link, &info, &info_len);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_obj_get_info");
+		goto out_unlink;
+	}
+	CHECK_FAIL(info_len != sizeof(info));
+
+	/* Expect no info change after update except in prog id */
+	CHECK_FAIL(info.type != BPF_LINK_TYPE_NETNS);
+	CHECK_FAIL(info.id != link_id);
+	CHECK_FAIL(info.prog_id != query_prog_id(prog2));
+	CHECK_FAIL(info.netns.netns_ino != netns_stat.st_ino);
+	CHECK_FAIL(info.netns.attach_type != BPF_FLOW_DISSECTOR);
+
+	/* Leave netns link is attached to and close last FD to it */
+	err = setns(old_net, CLONE_NEWNET);
+	if (CHECK_FAIL(err)) {
+		perror("setns(NEWNET)");
+		goto out_unlink;
+	}
+	close(netns);
+	old_net = -1;
+	netns = -1;
+
+	info_len = sizeof(info);
+	err = bpf_obj_get_info_by_fd(link, &info, &info_len);
+	if (CHECK_FAIL(err)) {
+		perror("bpf_obj_get_info");
+		goto out_unlink;
+	}
+	CHECK_FAIL(info_len != sizeof(info));
+
+	/* Expect netns_ino to change to 0 */
+	CHECK_FAIL(info.type != BPF_LINK_TYPE_NETNS);
+	CHECK_FAIL(info.id != link_id);
+	CHECK_FAIL(info.prog_id != query_prog_id(prog2));
+	CHECK_FAIL(info.netns.netns_ino != 0);
+	CHECK_FAIL(info.netns.attach_type != BPF_FLOW_DISSECTOR);
+
+out_unlink:
+	close(link);
+out_resetns:
+	if (old_net != -1)
+		setns(old_net, CLONE_NEWNET);
+	if (netns != -1)
+		close(netns);
+}
+
+static void run_tests(int netns)
+{
+	struct test {
+		const char *test_name;
+		void (*test_func)(int netns, int prog1, int prog2);
+	} tests[] = {
+		{ "prog attach, prog attach",
+		  test_prog_attach_prog_attach },
+		{ "link create, link create",
+		  test_link_create_link_create },
+		{ "prog attach, link create",
+		  test_prog_attach_link_create },
+		{ "link create, prog attach",
+		  test_link_create_prog_attach },
+		{ "link create, prog detach",
+		  test_link_create_prog_detach },
+		{ "prog attach, detach, query",
+		  test_prog_attach_detach_query },
+		{ "link create, close, query",
+		  test_link_create_close_query },
+		{ "link update no old prog",
+		  test_link_update_no_old_prog },
+		{ "link update with replace old prog",
+		  test_link_update_replace_old_prog },
+		{ "link update with same prog",
+		  test_link_update_same_prog },
+		{ "link update invalid opts",
+		  test_link_update_invalid_opts },
+		{ "link update invalid prog",
+		  test_link_update_invalid_prog },
+		{ "link update netns gone",
+		  test_link_update_netns_gone },
+		{ "link get info",
+		  test_link_get_info },
+	};
+	int i, progs[2] = { -1, -1 };
+	char test_name[80];
+
+	for (i = 0; i < ARRAY_SIZE(progs); i++) {
+		progs[i] = load_prog(BPF_PROG_TYPE_FLOW_DISSECTOR);
+		if (progs[i] < 0)
+			goto out_close;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(tests); i++) {
+		snprintf(test_name, sizeof(test_name),
+			 "flow dissector %s%s",
+			 tests[i].test_name,
+			 netns == init_net ? " (init_net)" : "");
+		if (test__start_subtest(test_name))
+			tests[i].test_func(netns, progs[0], progs[1]);
+	}
+out_close:
+	for (i = 0; i < ARRAY_SIZE(progs); i++) {
+		if (progs[i] != -1)
+			CHECK_FAIL(close(progs[i]));
+	}
+}
+
+void test_flow_dissector_reattach(void)
+{
+	int err, new_net, saved_net;
+
+	saved_net = open("/proc/self/ns/net", O_RDONLY);
+	if (CHECK_FAIL(saved_net < 0)) {
+		perror("open(/proc/self/ns/net");
+		return;
+	}
+
+	init_net = open("/proc/1/ns/net", O_RDONLY);
+	if (CHECK_FAIL(init_net < 0)) {
+		perror("open(/proc/1/ns/net)");
+		goto out_close;
+	}
+
+	err = setns(init_net, CLONE_NEWNET);
+	if (CHECK_FAIL(err)) {
+		perror("setns(/proc/1/ns/net)");
+		goto out_close;
+	}
+
+	if (prog_is_attached(init_net)) {
+		test__skip();
+		printf("Can't test with flow dissector attached to init_net\n");
+		goto out_setns;
+	}
+
+	/* First run tests in root network namespace */
+	run_tests(init_net);
+
+	/* Then repeat tests in a non-root namespace */
+	new_net = unshare_net(init_net);
+	if (new_net < 0)
+		goto out_setns;
+	run_tests(new_net);
+	close(new_net);
+
+out_setns:
+	/* Move back to netns we started in. */
+	err = setns(saved_net, CLONE_NEWNET);
+	if (CHECK_FAIL(err))
+		perror("setns(/proc/self/ns/net)");
+
+out_close:
+	close(init_net);
+	close(saved_net);
+}