// SPDX-License-Identifier: GPL-2.0
#include <kunit/test.h>

#include "protocol.h"

static struct mptcp_subflow_request_sock *build_req_sock(struct kunit *test)
{
        struct mptcp_subflow_request_sock *req;

        req = kunit_kzalloc(test, sizeof(struct mptcp_subflow_request_sock),
                            GFP_USER);
        KUNIT_EXPECT_NOT_ERR_OR_NULL(test, req);
        mptcp_token_init_request((struct request_sock *)req);
        sock_net_set((struct sock *)req, &init_net);
        return req;
}

static void mptcp_token_test_req_basic(struct kunit *test)
{
        struct mptcp_subflow_request_sock *req = build_req_sock(test);
        struct mptcp_sock *null_msk = NULL;

        KUNIT_ASSERT_EQ(test, 0,
                        mptcp_token_new_request((struct request_sock *)req));
        KUNIT_EXPECT_NE(test, 0, (int)req->token);
        KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(&init_net, req->token));

        /* cleanup */
        mptcp_token_destroy_request((struct request_sock *)req);
}

static struct inet_connection_sock *build_icsk(struct kunit *test)
{
        struct inet_connection_sock *icsk;

        icsk = kunit_kzalloc(test, sizeof(struct inet_connection_sock),
                             GFP_USER);
        KUNIT_EXPECT_NOT_ERR_OR_NULL(test, icsk);
        return icsk;
}

static struct mptcp_subflow_context *build_ctx(struct kunit *test)
{
        struct mptcp_subflow_context *ctx;

        ctx = kunit_kzalloc(test, sizeof(struct mptcp_subflow_context),
                            GFP_USER);
        KUNIT_EXPECT_NOT_ERR_OR_NULL(test, ctx);
        return ctx;
}

static struct mptcp_sock *build_msk(struct kunit *test)
{
        struct mptcp_sock *msk;
        struct sock *sk;

        msk = kunit_kzalloc(test, sizeof(struct mptcp_sock), GFP_USER);
        KUNIT_EXPECT_NOT_ERR_OR_NULL(test, msk);
        refcount_set(&((struct sock *)msk)->sk_refcnt, 1);
        sock_net_set((struct sock *)msk, &init_net);

        sk = (struct sock *)msk;

        /* be sure the token helpers can dereference sk->sk_prot */
        sk->sk_prot = &tcp_prot;
        sk->sk_protocol = IPPROTO_MPTCP;

        return msk;
}

static void mptcp_token_test_msk_basic(struct kunit *test)
{
        struct inet_connection_sock *icsk = build_icsk(test);
        struct mptcp_subflow_context *ctx = build_ctx(test);
        struct mptcp_sock *msk = build_msk(test);
        struct mptcp_sock *null_msk = NULL;
        struct sock *sk;

        rcu_assign_pointer(icsk->icsk_ulp_data, ctx);
        ctx->conn = (struct sock *)msk;
        sk = (struct sock *)msk;

        KUNIT_ASSERT_EQ(test, 0,
                        mptcp_token_new_connect((struct sock *)icsk));
        KUNIT_EXPECT_NE(test, 0, (int)ctx->token);
        KUNIT_EXPECT_EQ(test, ctx->token, msk->token);
        KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(&init_net, ctx->token));
        KUNIT_EXPECT_EQ(test, 2, (int)refcount_read(&sk->sk_refcnt));

        mptcp_token_destroy(msk);
        KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(&init_net, ctx->token));
}

static void mptcp_token_test_accept(struct kunit *test)
{
        struct mptcp_subflow_request_sock *req = build_req_sock(test);
        struct mptcp_sock *msk = build_msk(test);

        KUNIT_ASSERT_EQ(test, 0,
                        mptcp_token_new_request((struct request_sock *)req));
        msk->token = req->token;
        mptcp_token_accept(req, msk);
        KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(&init_net, msk->token));

        /* this is now a no-op */
        mptcp_token_destroy_request((struct request_sock *)req);
        KUNIT_EXPECT_PTR_EQ(test, msk, mptcp_token_get_sock(&init_net, msk->token));

        /* cleanup */
        mptcp_token_destroy(msk);
}

static void mptcp_token_test_destroyed(struct kunit *test)
{
        struct mptcp_subflow_request_sock *req = build_req_sock(test);
        struct mptcp_sock *msk = build_msk(test);
        struct mptcp_sock *null_msk = NULL;
        struct sock *sk;

        sk = (struct sock *)msk;

        KUNIT_ASSERT_EQ(test, 0,
                        mptcp_token_new_request((struct request_sock *)req));
        msk->token = req->token;
        mptcp_token_accept(req, msk);

        /* simulate race on removal */
        refcount_set(&sk->sk_refcnt, 0);
        KUNIT_EXPECT_PTR_EQ(test, null_msk, mptcp_token_get_sock(&init_net, msk->token));

        /* cleanup */
        mptcp_token_destroy(msk);
}

static struct kunit_case mptcp_token_test_cases[] = {
        KUNIT_CASE(mptcp_token_test_req_basic),
        KUNIT_CASE(mptcp_token_test_msk_basic),
        KUNIT_CASE(mptcp_token_test_accept),
        KUNIT_CASE(mptcp_token_test_destroyed),
        {}
};

static struct kunit_suite mptcp_token_suite = {
        .name = "mptcp-token",
        .test_cases = mptcp_token_test_cases,
};

kunit_test_suite(mptcp_token_suite);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("KUnit tests for MPTCP Token");