tools/testing/selftests/bpf/prog_tests/sockopt_multi.c

// SPDX-License-Identifier: GPL-2.0
#include <test_progs.h>
#include "cgroup_helpers.h"

#include "sockopt_multi.skel.h"

static int run_getsockopt_test(struct sockopt_multi *obj, int cg_parent,
			       int cg_child, int sock_fd)
{
	struct bpf_link *link_parent = NULL;
	struct bpf_link *link_child = NULL;
	socklen_t optlen;
	__u8 buf;
	int err;

	/* Set IP_TOS to the expected value (0x80). */

	buf = 0x80;
	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
	if (err < 0) {
		log_err("Failed to call setsockopt(IP_TOS)");
		goto detach;
	}

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (err) {
		log_err("Failed to call getsockopt(IP_TOS)");
		goto detach;
	}

	if (buf != 0x80) {
		log_err("Unexpected getsockopt 0x%x != 0x80 without BPF", buf);
		err = -1;
		goto detach;
	}

	/* Attach child program and make sure it returns new value:
	 * - kernel:      -> 0x80
	 * - child:  0x80 -> 0x90
	 */

	link_child = bpf_program__attach_cgroup(obj->progs._getsockopt_child,
						cg_child);
	if (!ASSERT_OK_PTR(link_child, "cg-attach-getsockopt_child"))
		goto detach;

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (err) {
		log_err("Failed to call getsockopt(IP_TOS)");
		goto detach;
	}

	if (buf != 0x90) {
		log_err("Unexpected getsockopt 0x%x != 0x90", buf);
		err = -1;
		goto detach;
	}

	/* Attach parent program and make sure it returns new value:
	 * - kernel:      -> 0x80
	 * - child:  0x80 -> 0x90
	 * - parent: 0x90 -> 0xA0
	 */

	link_parent = bpf_program__attach_cgroup(obj->progs._getsockopt_parent,
						 cg_parent);
	if (!ASSERT_OK_PTR(link_parent, "cg-attach-getsockopt_parent"))
		goto detach;

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (err) {
		log_err("Failed to call getsockopt(IP_TOS)");
		goto detach;
	}

	if (buf != 0xA0) {
		log_err("Unexpected getsockopt 0x%x != 0xA0", buf);
		err = -1;
		goto detach;
	}

	/* Setting unexpected initial sockopt should return EPERM:
	 * - kernel: -> 0x40
	 * - child:  unexpected 0x40, EPERM
	 * - parent: unexpected 0x40, EPERM
	 */

	buf = 0x40;
	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
	if (err < 0) {
		log_err("Failed to call setsockopt(IP_TOS)");
		goto detach;
	}

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (!err) {
		log_err("Unexpected success from getsockopt(IP_TOS)");
		goto detach;
	}

	/* Detach child program and make sure we still get EPERM:
	 * - kernel: -> 0x40
	 * - parent: unexpected 0x40, EPERM
	 */

	bpf_link__destroy(link_child);
	link_child = NULL;

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (!err) {
		log_err("Unexpected success from getsockopt(IP_TOS)");
		goto detach;
	}

	/* Set initial value to the one the parent program expects:
	 * - kernel:      -> 0x90
	 * - parent: 0x90 -> 0xA0
	 */

	buf = 0x90;
	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
	if (err < 0) {
		log_err("Failed to call setsockopt(IP_TOS)");
		goto detach;
	}

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (err) {
		log_err("Failed to call getsockopt(IP_TOS)");
		goto detach;
	}

	if (buf != 0xA0) {
		log_err("Unexpected getsockopt 0x%x != 0xA0", buf);
		err = -1;
		goto detach;
	}

detach:
	bpf_link__destroy(link_child);
	bpf_link__destroy(link_parent);

	return err;
}

static int run_setsockopt_test(struct sockopt_multi *obj, int cg_parent,
			       int cg_child, int sock_fd)
{
	struct bpf_link *link_parent = NULL;
	struct bpf_link *link_child = NULL;
	socklen_t optlen;
	__u8 buf;
	int err;

	/* Set IP_TOS to the expected value (0x80). */

	buf = 0x80;
	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
	if (err < 0) {
		log_err("Failed to call setsockopt(IP_TOS)");
		goto detach;
	}

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (err) {
		log_err("Failed to call getsockopt(IP_TOS)");
		goto detach;
	}

	if (buf != 0x80) {
		log_err("Unexpected getsockopt 0x%x != 0x80 without BPF", buf);
		err = -1;
		goto detach;
	}

	/* Attach child program and make sure it adds 0x10. */

	link_child = bpf_program__attach_cgroup(obj->progs._setsockopt,
						cg_child);
	if (!ASSERT_OK_PTR(link_child, "cg-attach-setsockopt_child"))
		goto detach;

	buf = 0x80;
	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
	if (err < 0) {
		log_err("Failed to call setsockopt(IP_TOS)");
		goto detach;
	}

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (err) {
		log_err("Failed to call getsockopt(IP_TOS)");
		goto detach;
	}

	if (buf != 0x80 + 0x10) {
		log_err("Unexpected getsockopt 0x%x != 0x80 + 0x10", buf);
		err = -1;
		goto detach;
	}

	/* Attach parent program and make sure it adds another 0x10. */

	link_parent = bpf_program__attach_cgroup(obj->progs._setsockopt,
						 cg_parent);
	if (!ASSERT_OK_PTR(link_parent, "cg-attach-setsockopt_parent"))
		goto detach;

	buf = 0x80;
	err = setsockopt(sock_fd, SOL_IP, IP_TOS, &buf, 1);
	if (err < 0) {
		log_err("Failed to call setsockopt(IP_TOS)");
		goto detach;
	}

	buf = 0x00;
	optlen = 1;
	err = getsockopt(sock_fd, SOL_IP, IP_TOS, &buf, &optlen);
	if (err) {
		log_err("Failed to call getsockopt(IP_TOS)");
		goto detach;
	}

	if (buf != 0x80 + 2 * 0x10) {
		log_err("Unexpected getsockopt 0x%x != 0x80 + 2 * 0x10", buf);
		err = -1;
		goto detach;
	}

detach:
	bpf_link__destroy(link_child);
	bpf_link__destroy(link_parent);

	return err;
}

void test_sockopt_multi(void)
{
	int cg_parent = -1, cg_child = -1;
	struct sockopt_multi *obj = NULL;
	int sock_fd = -1;

	cg_parent = test__join_cgroup("/parent");
	if (!ASSERT_GE(cg_parent, 0, "join_cgroup /parent"))
		goto out;

	cg_child = test__join_cgroup("/parent/child");
	if (!ASSERT_GE(cg_child, 0, "join_cgroup /parent/child"))
		goto out;

	obj = sockopt_multi__open_and_load();
	if (!ASSERT_OK_PTR(obj, "skel-load"))
		goto out;

	obj->bss->page_size = sysconf(_SC_PAGESIZE);

	sock_fd = socket(AF_INET, SOCK_STREAM, 0);
	if (!ASSERT_GE(sock_fd, 0, "socket"))
		goto out;

	ASSERT_OK(run_getsockopt_test(obj, cg_parent, cg_child, sock_fd), "getsockopt_test");
	ASSERT_OK(run_setsockopt_test(obj, cg_parent, cg_child, sock_fd), "setsockopt_test");

out:
	close(sock_fd);
	sockopt_multi__destroy(obj);
	close(cg_child);
	close(cg_parent);
}