// 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);
}