/*-
 * Copyright (c) 2023 John Baldwin <jhb@FreeBSD.org>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 */

/*
 * Fetch the value of fwctl nodes from a guest.
 *
 * Usage: fwctl_fetch <node>
 */

#include <sys/param.h>
#include <err.h>
#include <fcntl.h>
#include <libutil.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <machine/cpufunc.h>

#define OP_GET          3
#define OP_GET_LEN      4

/* I/O ports */
#define FWCTL_OUT       0x510
#define FWCTL_IN        0x511

static void
reset_fwctl(void)
{
        char buf[4];

        outw(FWCTL_OUT, 0);
        for (u_int i = 0; i < 4; i++)
                buf[i] = inb(FWCTL_IN);
        if (memcmp(buf, "BHYV", 4) != 0)
                errx(1, "Signature mismatch: %.4s", buf);
}

static void
send_node_name(const char *name)
{
        uint32_t value;
        size_t len;

        len = strlen(name) + 1;
        while (len > 4) {
                memcpy(&value, name, 4);
                outl(FWCTL_OUT, value);
                name += 4;
                len -= 4;
        }

        if (len > 0) {
                value = 0;
                memcpy(&value, name, len);
                outl(FWCTL_OUT, value);
        }
}

static void
fwctl_op(uint32_t op, uint32_t id, const char *name, void *buf, size_t len)
{
        char *cp;
        uint32_t value, rsplen;

        /* Length */
        outl(FWCTL_OUT, 12 + strlen(name) + 1);

        /* Operation */
        outl(FWCTL_OUT, op);

        /* Transaction ID */
        outl(FWCTL_OUT, id);

        send_node_name(name);

        /* Length */
        rsplen = inl(FWCTL_IN);

        /* If there is an error, the response will have no payload. */
        if (rsplen < 4 * sizeof(value))
                errx(1, "Invalid response length (%u): %u", id, rsplen);

        /* Operation */
        value = inl(FWCTL_IN);
        if (value != op)
                errx(1, "Invalid response type (%u): %u", id, value);

        /* Transaction ID */
        value = inl(FWCTL_IN);
        if (value != id)
                errx(1, "Invalid response ID (%u): %u", id, value);

        /* Error */
        value = inl(FWCTL_IN);
        if (value != 0)
                errx(1, "Error from op %u (%u): %u", op, id, value);

        /* If there wasn't an error, require payload length to match */
        if (rsplen != 4 * sizeof(value) + len)
                errx(1, "Response payload length mismatch (%u): %zu vs %zu", id,
                    rsplen - 4 * sizeof(value), len);

        cp = buf;
        while (len > 0) {
                value = inl(FWCTL_IN);
                memcpy(cp, &value, 4);
                cp += 4;
                len -= 4;
        }
}

int
main(int ac, char **av)
{
        char *p;
        size_t len, buflen, len2;

        if (ac != 2)
                errx(1, "Need node name");

        if (open("/dev/io", O_RDWR) == -1)
                err(1, "Failed to open /dev/io");

        reset_fwctl();

        fwctl_op(OP_GET_LEN, 1, av[1], &len, sizeof(len));
        if (len == 0)
                errx(1, "Node has length of 0");

        /* Buffer includes embedded length followed by value. */
        buflen = sizeof(size_t) + roundup2(len, 4);
        p = malloc(buflen);
        fwctl_op(OP_GET, 2, av[1], p, buflen);
        memcpy(&len2, p, sizeof(len2));
        if (len2 != len)
                errx(1, "Length mismatch: %zu vs %zu", len, len2);
        hexdump(p + sizeof(len2), len, NULL, 0);

        return (0);
}