/*
 * Copyright (c) 2011 Google, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/disk.h>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/filio.h>
#include <dirent.h>
#include <dlfcn.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <inttypes.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>
#include <unistd.h>

#include <userboot.h>

int *zfs_debug;

static int script;
static char *host_base;
static struct termios term, oldterm;
static char *image;
static size_t image_size;

uint64_t regs[16];
uint64_t pc;
int *disk_fd;
int disk_index = -1;

void test_exit(void *arg, int v);

const char *
_umem_debug_init(void)
{
        return ("default,verbose"); /* $UMEM_DEBUG setting */
}

const char *
_umem_logging_init(void)
{
        return ("fail,contents"); /* $UMEM_LOGGING setting */
}

/*
 * Console i/o
 */

void
test_putc(void *arg, int ch)
{
        char c = ch;

        (void) write(1, &c, 1);
}

int
test_getc(void *arg)
{
        char c;

        if (read(script, &c, 1) == 1) {
                if (c == '\n')
                        c = '\r';
                return (c);
        }
        return (-1);
}

int
test_poll(void *arg)
{
        int n;

        if (ioctl(script, FIONREAD, &n) >= 0)
                return (n > 0);
        return (0);
}

/*
 * Host filesystem i/o
 */

struct test_file {
        char *tf_name;
        int tf_isdir;
        size_t tf_size;
        struct stat tf_stat;
        union {
                int fd;
                DIR *dir;
        } tf_u;
};

int
test_open(void *arg, const char *filename, void **h_return)
{
        struct test_file *tf;
        char path[PATH_MAX];

        if (!host_base)
                return (ENOENT);

        (void) strlcpy(path, host_base, PATH_MAX);
        if (path[strlen(path) - 1] == '/')
                path[strlen(path) - 1] = 0;
        (void) strlcat(path, filename, PATH_MAX);
        tf = malloc(sizeof (struct test_file));
        if (stat(path, &tf->tf_stat) < 0) {
                free(tf);
                return (errno);
        }

        tf->tf_name = strdup(path);
        tf->tf_size = tf->tf_stat.st_size;
        if (S_ISDIR(tf->tf_stat.st_mode)) {
                tf->tf_isdir = 1;
                tf->tf_u.dir = opendir(path);
                if (!tf->tf_u.dir)
                        goto out;
                *h_return = tf;
                return (0);
        }
        if (S_ISREG(tf->tf_stat.st_mode)) {
                tf->tf_isdir = 0;
                tf->tf_u.fd = open(path, O_RDONLY);
                if (tf->tf_u.fd < 0)
                        goto out;
                *h_return = tf;
                return (0);
        }

out:
        free(tf);
        return (EINVAL);
}

int
test_close(void *arg, void *h)
{
        struct test_file *tf = h;

        if (tf->tf_isdir)
                (void) closedir(tf->tf_u.dir);
        else
                (void) close(tf->tf_u.fd);
        free(tf->tf_name);
        free(tf);

        return (0);
}

int
test_isdir(void *arg, void *h)
{
        struct test_file *tf = h;

        return (tf->tf_isdir);
}

int
test_read(void *arg, void *h, void *dst, size_t size, size_t *resid_return)
{
        struct test_file *tf = h;
        ssize_t sz;

        if (tf->tf_isdir)
                return (EINVAL);
        sz = read(tf->tf_u.fd, dst, size);
        if (sz < 0)
                return (EINVAL);
        *resid_return = size - sz;
        return (0);
}

int
test_readdir(void *arg, void *h, uint32_t *fileno_return, uint8_t *type_return,
    size_t *namelen_return, char *name)
{
        struct test_file *tf = h;
        struct dirent *dp;
        struct stat st;
        char path[PATH_MAX];

        if (!tf->tf_isdir)
                return (EINVAL);

        dp = readdir(tf->tf_u.dir);
        if (!dp)
                return (ENOENT);
        (void) snprintf(path, sizeof (path), "%s/%s/%s", host_base, tf->tf_name,
            dp->d_name);
        if (lstat(path, &st) < 0) {
                return (errno);
        } else {
                *type_return = (st.st_mode & S_IFMT) >> 12;
        }

        /*
         * Note: d_namlen is in the range 0..255 and therefore less
         * than PATH_MAX so we don't need to test before copying.
         */
        *fileno_return = dp->d_ino;
        *namelen_return = strlen(dp->d_name);
        (void) strcpy(name, dp->d_name);

        return (0);
}

int
test_seek(void *arg, void *h, uint64_t offset, int whence)
{
        struct test_file *tf = h;

        if (tf->tf_isdir)
                return (EINVAL);
        if (lseek(tf->tf_u.fd, offset, whence) < 0)
                return (errno);
        return (0);
}

int
test_stat(void *arg, void *h, int *mode_return, int *uid_return,
    int *gid_return, uint64_t *size_return)
{
        struct test_file *tf = h;

        *mode_return = tf->tf_stat.st_mode;
        *uid_return = tf->tf_stat.st_uid;
        *gid_return = tf->tf_stat.st_gid;
        *size_return = tf->tf_stat.st_size;
        return (0);
}

/*
 * Disk image i/o
 */

int
test_diskwrite(void *arg, int unit, uint64_t offset, void *src, size_t size,
    size_t *resid_return)
{
        ssize_t n;

        if (unit > disk_index || disk_fd[unit] == -1)
                return (EIO);
        n = pwrite(disk_fd[unit], src, size, offset);
        if (n < 0)
                return (errno);
        *resid_return = size - n;
        return (0);
}

int
test_diskread(void *arg, int unit, uint64_t offset, void *dst, size_t size,
    size_t *resid_return)
{
        ssize_t n;

        if (unit > disk_index || disk_fd[unit] == -1)
                return (EIO);
        n = pread(disk_fd[unit], dst, size, offset);
        if (n == 0) {
                printf("%s: end of disk (%ju)\n", __func__, (intmax_t)offset);
                return (EIO);
        }

        if (n < 0)
                return (errno);
        *resid_return = size - n;
        return (0);
}

int
test_diskioctl(void *arg, int unit, ulong_t cmd, void *data)
{
        struct stat sb;

        if (unit > disk_index || disk_fd[unit] == -1)
                return (EBADF);
        switch (cmd) {
        case DIOCGSECTORSIZE:
                *(uint_t *)data = 512;
                break;
        case DIOCGMEDIASIZE:
                if (fstat(disk_fd[unit], &sb) == 0)
                        *(off_t *)data = sb.st_size;
                else
                        return (ENOTTY);
                break;
        default:
                return (ENOTTY);
        }
        return (0);
}

/*
 * Guest virtual machine i/o
 *
 * Note: guest addresses are kernel virtual
 */

int
test_copyin(void *arg, const void *from, uint64_t to, size_t size)
{

        to &= 0x7fffffff;
        if (to > image_size)
                return (EFAULT);
        if (to + size > image_size)
                size = image_size - to;
        memcpy(&image[to], from, size);
        return (0);
}

int
test_copyout(void *arg, uint64_t from, void *to, size_t size)
{

        from &= 0x7fffffff;
        if (from > image_size)
                return (EFAULT);
        if (from + size > image_size)
                size = image_size - from;
        memcpy(to, &image[from], size);
        return (0);
}

void
test_setreg(void *arg, int r, uint64_t v)
{

        if (r < 0 || r >= 16)
                return;
        regs[r] = v;
}

void
test_setmsr(void *arg, int r, uint64_t v)
{
}

void
test_setcr(void *arg, int r, uint64_t v)
{
}

void
test_setgdt(void *arg, uint64_t v, size_t sz)
{
}

void
test_exec(void *arg, uint64_t pc)
{
        printf("Execute at 0x%"PRIx64"\n\r", pc);
        test_exit(arg, 0);
}

/*
 * Misc
 */

void
test_delay(void *arg, int usec)
{

        (void) usleep(usec);
}

void
test_exit(void *arg, int v)
{

        (void) tcsetattr(0, TCSAFLUSH, &oldterm);
        exit(v);
}

void
test_getmem(void *arg, uint64_t *lowmem, uint64_t *highmem)
{

        *lowmem = 128*1024*1024;
        *highmem = 0;
}

char *
test_getenv(void *arg, int idx)
{
        extern char **environ;

        return (environ[idx]);
}

struct loader_callbacks cb = {
        .putc = test_putc,
        .getc = test_getc,
        .poll = test_poll,

        .open = test_open,
        .close = test_close,
        .isdir = test_isdir,
        .read = test_read,
        .readdir = test_readdir,
        .seek = test_seek,
        .stat = test_stat,

        .diskread = test_diskread,
        .diskwrite = test_diskwrite,
        .diskioctl = test_diskioctl,

        .copyin = test_copyin,
        .copyout = test_copyout,
        .setreg = test_setreg,
        .setmsr = test_setmsr,
        .setcr = test_setcr,
        .setgdt = test_setgdt,
        .exec = test_exec,

        .delay = test_delay,
        .exit = test_exit,
        .getmem = test_getmem,

        .getenv = test_getenv,
};

void
usage(void)
{

        printf("usage: [-b <userboot shared object>] [-d <disk image path>] "
            "[-h <host filesystem path>\n");
        exit(1);
}

int
main(int argc, char **argv)
{
        void *h;
        void (*func)(struct loader_callbacks *, void *, int, int) __NORETURN;
        int opt;
        const char *userboot_obj = "/boot/userboot.so";
        struct winsize ws;
        int cols = 80, rows = 24, z = 0;
        int oflag = O_RDONLY;
        char *buffer = NULL;

        if (ioctl(1, TIOCGWINSZ, &ws) != -1) {
                if (ws.ws_col)
                        cols = ws.ws_col;
                if (ws.ws_row)
                        rows = ws.ws_row;
        }

        (void) clearenv();
        if (asprintf(&buffer, "%d", cols) > 0)
                (void) setenv("screen-#cols", buffer, 1);
        free(buffer);
        if (asprintf(&buffer, "%d", rows) > 0)
                (void) setenv("screen-#rows", buffer, 1);
        free(buffer);
        (void) setenv("ISADIR", "amd64", 1);

        while ((opt = getopt(argc, argv, "b:d:h:s:wz")) != -1) {
                switch (opt) {
                case 'b':
                        userboot_obj = optarg;
                        break;

                case 'd':
                        disk_index++;
                        disk_fd = reallocarray(disk_fd, disk_index + 1,
                            sizeof (int));
                        disk_fd[disk_index] = open(optarg, oflag);
                        if (disk_fd[disk_index] < 0)
                                err(1, "Can't open disk image '%s'", optarg);
                        break;

                case 'h':
                        host_base = optarg;
                        break;

                case 's':
                        if (strcmp(optarg, "-") == 0)
                                script = 0;
                        else
                                script = open(optarg, O_RDONLY);

                        if (script < 0)
                                err(1, "Can't open script file '%s'", optarg);
                        break;

                case 'w':
                        oflag = O_RDWR;
                        break;

                case 'z':
                        z = 1;
                        break;

                case '?':
                        usage();
                }
        }

        h = dlopen(userboot_obj, RTLD_LAZY | RTLD_LOCAL);
        if (!h) {
                printf("%s\n", dlerror());
                return (1);
        }
        func = dlsym(h, "loader_main");
        if (!func) {
                printf("%s\n", dlerror());
                return (1);
        }
        zfs_debug = dlsym(h, "zfs_debug");
        if (zfs_debug != NULL)
                *zfs_debug = z;

        image_size = 128*1024*1024;
        image = malloc(image_size);

        (void) tcgetattr(0, &term);
        oldterm = term;
        term.c_iflag &= ~(ICRNL | INPCK | ISTRIP);
        term.c_lflag &= ~(ICANON | ECHO | IEXTEN);
        term.c_cflag &= ~(CSIZE | PARENB);
        term.c_cflag |= CS8;
        term.c_oflag &= ~(OPOST);
        term.c_cc[VMIN] = 1;
        term.c_cc[VTIME] = 0;
        (void) tcsetattr(0, TCSADRAIN, &term);

        func(&cb, NULL, USERBOOT_VERSION_3, disk_index + 1);
}