// SPDX-License-Identifier: GPL-2.0
/* This is over-simplified TCP_REPAIR for TCP_ESTABLISHED sockets
 * It tests that TCP-AO enabled connection can be restored.
 * For the proper socket repair see:
 * https://github.com/checkpoint-restore/criu/blob/criu-dev/soccr/soccr.h
 */
#include <fcntl.h>
#include <linux/sockios.h>
#include <sys/ioctl.h>
#include "aolib.h"

#ifndef TCPOPT_MAXSEG
# define TCPOPT_MAXSEG          2
#endif
#ifndef TCPOPT_WINDOW
# define TCPOPT_WINDOW          3
#endif
#ifndef TCPOPT_SACK_PERMITTED
# define TCPOPT_SACK_PERMITTED  4
#endif
#ifndef TCPOPT_TIMESTAMP
# define TCPOPT_TIMESTAMP       8
#endif

enum {
        TCP_ESTABLISHED = 1,
        TCP_SYN_SENT,
        TCP_SYN_RECV,
        TCP_FIN_WAIT1,
        TCP_FIN_WAIT2,
        TCP_TIME_WAIT,
        TCP_CLOSE,
        TCP_CLOSE_WAIT,
        TCP_LAST_ACK,
        TCP_LISTEN,
        TCP_CLOSING,    /* Now a valid state */
        TCP_NEW_SYN_RECV,

        TCP_MAX_STATES  /* Leave at the end! */
};

static void test_sock_checkpoint_queue(int sk, int queue, int qlen,
                                       struct tcp_sock_queue *q)
{
        socklen_t len;
        int ret;

        if (setsockopt(sk, SOL_TCP, TCP_REPAIR_QUEUE, &queue, sizeof(queue)))
                test_error("setsockopt(TCP_REPAIR_QUEUE)");

        len = sizeof(q->seq);
        ret = getsockopt(sk, SOL_TCP, TCP_QUEUE_SEQ, &q->seq, &len);
        if (ret || len != sizeof(q->seq))
                test_error("getsockopt(TCP_QUEUE_SEQ): %d", (int)len);

        if (!qlen) {
                q->buf = NULL;
                return;
        }

        q->buf = malloc(qlen);
        if (q->buf == NULL)
                test_error("malloc()");
        ret = recv(sk, q->buf, qlen, MSG_PEEK | MSG_DONTWAIT);
        if (ret != qlen)
                test_error("recv(%d): %d", qlen, ret);
}

void __test_sock_checkpoint(int sk, struct tcp_sock_state *state,
                            void *addr, size_t addr_size)
{
        socklen_t len = sizeof(state->info);
        int ret;

        memset(state, 0, sizeof(*state));

        ret = getsockopt(sk, SOL_TCP, TCP_INFO, &state->info, &len);
        if (ret || len != sizeof(state->info))
                test_error("getsockopt(TCP_INFO): %d", (int)len);

        len = addr_size;
        if (getsockname(sk, addr, &len) || len != addr_size)
                test_error("getsockname(): %d", (int)len);

        len = sizeof(state->trw);
        ret = getsockopt(sk, SOL_TCP, TCP_REPAIR_WINDOW, &state->trw, &len);
        if (ret || len != sizeof(state->trw))
                test_error("getsockopt(TCP_REPAIR_WINDOW): %d", (int)len);

        if (ioctl(sk, SIOCOUTQ, &state->outq_len))
                test_error("ioctl(SIOCOUTQ)");

        if (ioctl(sk, SIOCOUTQNSD, &state->outq_nsd_len))
                test_error("ioctl(SIOCOUTQNSD)");
        test_sock_checkpoint_queue(sk, TCP_SEND_QUEUE, state->outq_len, &state->out);

        if (ioctl(sk, SIOCINQ, &state->inq_len))
                test_error("ioctl(SIOCINQ)");
        test_sock_checkpoint_queue(sk, TCP_RECV_QUEUE, state->inq_len, &state->in);

        if (state->info.tcpi_state == TCP_CLOSE)
                state->outq_len = state->outq_nsd_len = 0;

        len = sizeof(state->mss);
        ret = getsockopt(sk, SOL_TCP, TCP_MAXSEG, &state->mss, &len);
        if (ret || len != sizeof(state->mss))
                test_error("getsockopt(TCP_MAXSEG): %d", (int)len);

        len = sizeof(state->timestamp);
        ret = getsockopt(sk, SOL_TCP, TCP_TIMESTAMP, &state->timestamp, &len);
        if (ret || len != sizeof(state->timestamp))
                test_error("getsockopt(TCP_TIMESTAMP): %d", (int)len);
}

void test_ao_checkpoint(int sk, struct tcp_ao_repair *state)
{
        socklen_t len = sizeof(*state);
        int ret;

        memset(state, 0, sizeof(*state));

        ret = getsockopt(sk, SOL_TCP, TCP_AO_REPAIR, state, &len);
        if (ret || len != sizeof(*state))
                test_error("getsockopt(TCP_AO_REPAIR): %d", (int)len);
}

static void test_sock_restore_seq(int sk, int queue, uint32_t seq)
{
        if (setsockopt(sk, SOL_TCP, TCP_REPAIR_QUEUE, &queue, sizeof(queue)))
                test_error("setsockopt(TCP_REPAIR_QUEUE)");

        if (setsockopt(sk, SOL_TCP, TCP_QUEUE_SEQ, &seq, sizeof(seq)))
                test_error("setsockopt(TCP_QUEUE_SEQ)");
}

static void test_sock_restore_queue(int sk, int queue, void *buf, int len)
{
        int chunk = len;
        size_t off = 0;

        if (len == 0)
                return;

        if (setsockopt(sk, SOL_TCP, TCP_REPAIR_QUEUE, &queue, sizeof(queue)))
                test_error("setsockopt(TCP_REPAIR_QUEUE)");

        do {
                int ret;

                ret = send(sk, buf + off, chunk, 0);
                if (ret <= 0) {
                        if (chunk > 1024) {
                                chunk >>= 1;
                                continue;
                        }
                        test_error("send()");
                }
                off += ret;
                len -= ret;
        } while (len > 0);
}

void __test_sock_restore(int sk, const char *device,
                         struct tcp_sock_state *state,
                         void *saddr, void *daddr, size_t addr_size)
{
        struct tcp_repair_opt opts[4];
        unsigned int opt_nr = 0;
        long flags;

        if (bind(sk, saddr, addr_size))
                test_error("bind()");

        flags = fcntl(sk, F_GETFL);
        if ((flags < 0) || (fcntl(sk, F_SETFL, flags | O_NONBLOCK) < 0))
                test_error("fcntl()");

        test_sock_restore_seq(sk, TCP_RECV_QUEUE, state->in.seq - state->inq_len);
        test_sock_restore_seq(sk, TCP_SEND_QUEUE, state->out.seq - state->outq_len);

        if (device != NULL && setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
                                         device, strlen(device) + 1))
                test_error("setsockopt(SO_BINDTODEVICE, %s)", device);

        if (connect(sk, daddr, addr_size))
                test_error("connect()");

        if (state->info.tcpi_options & TCPI_OPT_SACK) {
                opts[opt_nr].opt_code = TCPOPT_SACK_PERMITTED;
                opts[opt_nr].opt_val = 0;
                opt_nr++;
        }
        if (state->info.tcpi_options & TCPI_OPT_WSCALE) {
                opts[opt_nr].opt_code = TCPOPT_WINDOW;
                opts[opt_nr].opt_val = state->info.tcpi_snd_wscale +
                                (state->info.tcpi_rcv_wscale << 16);
                opt_nr++;
        }
        if (state->info.tcpi_options & TCPI_OPT_TIMESTAMPS) {
                opts[opt_nr].opt_code = TCPOPT_TIMESTAMP;
                opts[opt_nr].opt_val = 0;
                opt_nr++;
        }
        opts[opt_nr].opt_code = TCPOPT_MAXSEG;
        opts[opt_nr].opt_val = state->mss;
        opt_nr++;

        if (setsockopt(sk, SOL_TCP, TCP_REPAIR_OPTIONS, opts, opt_nr * sizeof(opts[0])))
                test_error("setsockopt(TCP_REPAIR_OPTIONS)");

        if (state->info.tcpi_options & TCPI_OPT_TIMESTAMPS) {
                if (setsockopt(sk, SOL_TCP, TCP_TIMESTAMP,
                               &state->timestamp, opt_nr * sizeof(opts[0])))
                        test_error("setsockopt(TCP_TIMESTAMP)");
        }
        test_sock_restore_queue(sk, TCP_RECV_QUEUE, state->in.buf, state->inq_len);
        test_sock_restore_queue(sk, TCP_SEND_QUEUE, state->out.buf, state->outq_len);
        if (setsockopt(sk, SOL_TCP, TCP_REPAIR_WINDOW, &state->trw, sizeof(state->trw)))
                test_error("setsockopt(TCP_REPAIR_WINDOW)");
}

void test_ao_restore(int sk, struct tcp_ao_repair *state)
{
        if (setsockopt(sk, SOL_TCP, TCP_AO_REPAIR, state, sizeof(*state)))
                test_error("setsockopt(TCP_AO_REPAIR)");
}

void test_sock_state_free(struct tcp_sock_state *state)
{
        free(state->out.buf);
        free(state->in.buf);
}

void test_enable_repair(int sk)
{
        int val = TCP_REPAIR_ON;

        if (setsockopt(sk, SOL_TCP, TCP_REPAIR, &val, sizeof(val)))
                test_error("setsockopt(TCP_REPAIR)");
}

void test_disable_repair(int sk)
{
        int val = TCP_REPAIR_OFF_NO_WP;

        if (setsockopt(sk, SOL_TCP, TCP_REPAIR, &val, sizeof(val)))
                test_error("setsockopt(TCP_REPAIR)");
}

void test_kill_sk(int sk)
{
        test_enable_repair(sk);
        close(sk);
}