// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 */

#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <os.h>
#include "harddog.h"

struct dog_data {
        int stdin_fd;
        int stdout_fd;
        int close_me[2];
};

static void pre_exec(void *d)
{
        struct dog_data *data = d;

        dup2(data->stdin_fd, 0);
        dup2(data->stdout_fd, 1);
        dup2(data->stdout_fd, 2);
        close(data->stdin_fd);
        close(data->stdout_fd);
        close(data->close_me[0]);
        close(data->close_me[1]);
}

int start_watchdog(int *in_fd_ret, int *out_fd_ret, char *sock)
{
        struct dog_data data;
        int in_fds[2], out_fds[2], pid, n, err;
        char pid_buf[sizeof("nnnnnnn\0")], c;
        char *pid_args[] = { "/usr/bin/uml_watchdog", "-pid", pid_buf, NULL };
        char *mconsole_args[] = { "/usr/bin/uml_watchdog", "-mconsole", NULL,
                                  NULL };
        char **args = NULL;

        err = os_pipe(in_fds, 1, 0);
        if (err < 0) {
                printk("harddog_open - os_pipe failed, err = %d\n", -err);
                goto out;
        }

        err = os_pipe(out_fds, 1, 0);
        if (err < 0) {
                printk("harddog_open - os_pipe failed, err = %d\n", -err);
                goto out_close_in;
        }

        data.stdin_fd = out_fds[0];
        data.stdout_fd = in_fds[1];
        data.close_me[0] = out_fds[1];
        data.close_me[1] = in_fds[0];

        if (sock != NULL) {
                mconsole_args[2] = sock;
                args = mconsole_args;
        }
        else {
                /* XXX The os_getpid() is not SMP correct */
                sprintf(pid_buf, "%d", os_getpid());
                args = pid_args;
        }

        pid = run_helper(pre_exec, &data, args);

        close(out_fds[0]);
        close(in_fds[1]);

        if (pid < 0) {
                err = -pid;
                printk("harddog_open - run_helper failed, errno = %d\n", -err);
                goto out_close_out;
        }

        n = read(in_fds[0], &c, sizeof(c));
        if (n == 0) {
                printk("harddog_open - EOF on watchdog pipe\n");
                helper_wait(pid);
                err = -EIO;
                goto out_close_out;
        }
        else if (n < 0) {
                printk("harddog_open - read of watchdog pipe failed, "
                       "err = %d\n", errno);
                helper_wait(pid);
                err = n;
                goto out_close_out;
        }
        *in_fd_ret = in_fds[0];
        *out_fd_ret = out_fds[1];
        return 0;

 out_close_in:
        close(in_fds[0]);
        close(in_fds[1]);
 out_close_out:
        close(out_fds[0]);
        close(out_fds[1]);
 out:
        return err;
}

void stop_watchdog(int in_fd, int out_fd)
{
        close(in_fd);
        close(out_fd);
}

int ping_watchdog(int fd)
{
        int n;
        char c = '\n';

        n = write(fd, &c, sizeof(c));
        if (n != sizeof(c)) {
                printk("ping_watchdog - write failed, ret = %d, err = %d\n",
                       n, errno);
                if (n < 0)
                        return n;
                return -EIO;
        }
        return 1;

}