/*
 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Licensed under the GPL
 */

#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/vfs.h>
#include <sys/syscall.h>
#include "hostfs.h"
#include <utime.h>

static void statx_to_hostfs(const struct statx *buf, struct hostfs_stat *p)
{
        p->ino = buf->stx_ino;
        p->mode = buf->stx_mode;
        p->nlink = buf->stx_nlink;
        p->uid = buf->stx_uid;
        p->gid = buf->stx_gid;
        p->size = buf->stx_size;
        p->atime.tv_sec = buf->stx_atime.tv_sec;
        p->atime.tv_nsec = buf->stx_atime.tv_nsec;
        p->ctime.tv_sec = buf->stx_ctime.tv_sec;
        p->ctime.tv_nsec = buf->stx_ctime.tv_nsec;
        p->mtime.tv_sec = buf->stx_mtime.tv_sec;
        p->mtime.tv_nsec = buf->stx_mtime.tv_nsec;
        if (buf->stx_mask & STATX_BTIME) {
                p->btime.tv_sec = buf->stx_btime.tv_sec;
                p->btime.tv_nsec = buf->stx_btime.tv_nsec;
        } else {
                memset(&p->btime, 0, sizeof(p->btime));
        }
        p->blksize = buf->stx_blksize;
        p->blocks = buf->stx_blocks;
        p->rdev.maj = buf->stx_rdev_major;
        p->rdev.min = buf->stx_rdev_minor;
        p->dev.maj = buf->stx_dev_major;
        p->dev.min = buf->stx_dev_minor;
}

int stat_file(const char *path, struct hostfs_stat *p, int fd)
{
        struct statx buf;
        int flags = AT_SYMLINK_NOFOLLOW;

        if (fd >= 0) {
                flags |= AT_EMPTY_PATH;
                path = "";
        }

        if ((statx(fd, path, flags, STATX_BASIC_STATS | STATX_BTIME, &buf)) < 0)
                return -errno;

        statx_to_hostfs(&buf, p);
        return 0;
}

int access_file(char *path, int r, int w, int x)
{
        int mode = 0;

        if (r)
                mode = R_OK;
        if (w)
                mode |= W_OK;
        if (x)
                mode |= X_OK;
        if (access(path, mode) != 0)
                return -errno;
        else return 0;
}

int open_file(char *path, int r, int w, int append)
{
        int mode = 0, fd;

        if (r && !w)
                mode = O_RDONLY;
        else if (!r && w)
                mode = O_WRONLY;
        else if (r && w)
                mode = O_RDWR;
        else panic("Impossible mode in open_file");

        if (append)
                mode |= O_APPEND;
        fd = open64(path, mode);
        if (fd < 0)
                return -errno;
        else return fd;
}

void *open_dir(char *path, int *err_out)
{
        DIR *dir;

        dir = opendir(path);
        *err_out = errno;

        return dir;
}

void seek_dir(void *stream, unsigned long long pos)
{
        DIR *dir = stream;

        seekdir(dir, pos);
}

char *read_dir(void *stream, unsigned long long *pos_out,
               unsigned long long *ino_out, int *len_out,
               unsigned int *type_out)
{
        DIR *dir = stream;
        struct dirent *ent;

        ent = readdir(dir);
        if (ent == NULL)
                return NULL;
        *len_out = strlen(ent->d_name);
        *ino_out = ent->d_ino;
        *type_out = ent->d_type;
        *pos_out = ent->d_off;
        return ent->d_name;
}

int read_file(int fd, unsigned long long *offset, char *buf, int len)
{
        int n;

        n = pread64(fd, buf, len, *offset);
        if (n < 0)
                return -errno;
        *offset += n;
        return n;
}

int write_file(int fd, unsigned long long *offset, const char *buf, int len)
{
        int n;

        n = pwrite64(fd, buf, len, *offset);
        if (n < 0)
                return -errno;
        *offset += n;
        return n;
}

int lseek_file(int fd, long long offset, int whence)
{
        int ret;

        ret = lseek64(fd, offset, whence);
        if (ret < 0)
                return -errno;
        return 0;
}

int fsync_file(int fd, int datasync)
{
        int ret;
        if (datasync)
                ret = fdatasync(fd);
        else
                ret = fsync(fd);

        if (ret < 0)
                return -errno;
        return 0;
}

int replace_file(int oldfd, int fd)
{
        return dup2(oldfd, fd);
}

void close_file(void *stream)
{
        close(*((int *) stream));
}

void close_dir(void *stream)
{
        closedir(stream);
}

int file_create(char *name, int mode)
{
        int fd;

        fd = open64(name, O_CREAT | O_RDWR, mode);
        if (fd < 0)
                return -errno;
        return fd;
}

int set_attr(const char *file, struct hostfs_iattr *attrs, int fd)
{
        struct hostfs_stat st;
        struct timeval times[2];
        int err, ma;

        if (attrs->ia_valid & HOSTFS_ATTR_MODE) {
                if (fd >= 0) {
                        if (fchmod(fd, attrs->ia_mode) != 0)
                                return -errno;
                } else if (chmod(file, attrs->ia_mode) != 0) {
                        return -errno;
                }
        }
        if (attrs->ia_valid & HOSTFS_ATTR_UID) {
                if (fd >= 0) {
                        if (fchown(fd, attrs->ia_uid, -1))
                                return -errno;
                } else if (chown(file, attrs->ia_uid, -1)) {
                        return -errno;
                }
        }
        if (attrs->ia_valid & HOSTFS_ATTR_GID) {
                if (fd >= 0) {
                        if (fchown(fd, -1, attrs->ia_gid))
                                return -errno;
                } else if (chown(file, -1, attrs->ia_gid)) {
                        return -errno;
                }
        }
        if (attrs->ia_valid & HOSTFS_ATTR_SIZE) {
                if (fd >= 0) {
                        if (ftruncate(fd, attrs->ia_size))
                                return -errno;
                } else if (truncate(file, attrs->ia_size)) {
                        return -errno;
                }
        }

        /*
         * Update accessed and/or modified time, in two parts: first set
         * times according to the changes to perform, and then call futimes()
         * or utimes() to apply them.
         */
        ma = (HOSTFS_ATTR_ATIME_SET | HOSTFS_ATTR_MTIME_SET);
        if (attrs->ia_valid & ma) {
                err = stat_file(file, &st, fd);
                if (err != 0)
                        return err;

                times[0].tv_sec = st.atime.tv_sec;
                times[0].tv_usec = st.atime.tv_nsec / 1000;
                times[1].tv_sec = st.mtime.tv_sec;
                times[1].tv_usec = st.mtime.tv_nsec / 1000;

                if (attrs->ia_valid & HOSTFS_ATTR_ATIME_SET) {
                        times[0].tv_sec = attrs->ia_atime.tv_sec;
                        times[0].tv_usec = attrs->ia_atime.tv_nsec / 1000;
                }
                if (attrs->ia_valid & HOSTFS_ATTR_MTIME_SET) {
                        times[1].tv_sec = attrs->ia_mtime.tv_sec;
                        times[1].tv_usec = attrs->ia_mtime.tv_nsec / 1000;
                }

                if (fd >= 0) {
                        if (futimes(fd, times) != 0)
                                return -errno;
                } else if (utimes(file, times) != 0) {
                        return -errno;
                }
        }

        /* Note: ctime is not handled */
        if (attrs->ia_valid & (HOSTFS_ATTR_ATIME | HOSTFS_ATTR_MTIME)) {
                err = stat_file(file, &st, fd);
                attrs->ia_atime = st.atime;
                attrs->ia_mtime = st.mtime;
                if (err != 0)
                        return err;
        }
        return 0;
}

int make_symlink(const char *from, const char *to)
{
        int err;

        err = symlink(to, from);
        if (err)
                return -errno;
        return 0;
}

int unlink_file(const char *file)
{
        int err;

        err = unlink(file);
        if (err)
                return -errno;
        return 0;
}

int do_mkdir(const char *file, int mode)
{
        int err;

        err = mkdir(file, mode);
        if (err)
                return -errno;
        return 0;
}

int hostfs_do_rmdir(const char *file)
{
        int err;

        err = rmdir(file);
        if (err)
                return -errno;
        return 0;
}

int do_mknod(const char *file, int mode, unsigned int major, unsigned int minor)
{
        int err;

        err = mknod(file, mode, os_makedev(major, minor));
        if (err)
                return -errno;
        return 0;
}

int link_file(const char *to, const char *from)
{
        int err;

        err = link(to, from);
        if (err)
                return -errno;
        return 0;
}

int hostfs_do_readlink(char *file, char *buf, int size)
{
        int n;

        n = readlink(file, buf, size);
        if (n < 0)
                return -errno;
        if (n < size)
                buf[n] = '\0';
        return n;
}

int rename_file(char *from, char *to)
{
        int err;

        err = rename(from, to);
        if (err < 0)
                return -errno;
        return 0;
}

int rename2_file(char *from, char *to, unsigned int flags)
{
        int err;

#ifndef SYS_renameat2
#  ifdef __x86_64__
#    define SYS_renameat2 316
#  endif
#  ifdef __i386__
#    define SYS_renameat2 353
#  endif
#endif

#ifdef SYS_renameat2
        err = syscall(SYS_renameat2, AT_FDCWD, from, AT_FDCWD, to, flags);
        if (err < 0) {
                if (errno != ENOSYS)
                        return -errno;
                else
                        return -EINVAL;
        }
        return 0;
#else
        return -EINVAL;
#endif
}

int do_statfs(char *root, long *bsize_out, long long *blocks_out,
              long long *bfree_out, long long *bavail_out,
              long long *files_out, long long *ffree_out,
              void *fsid_out, int fsid_size, long *namelen_out)
{
        struct statfs64 buf;
        int err;

        err = statfs64(root, &buf);
        if (err < 0)
                return -errno;

        *bsize_out = buf.f_bsize;
        *blocks_out = buf.f_blocks;
        *bfree_out = buf.f_bfree;
        *bavail_out = buf.f_bavail;
        *files_out = buf.f_files;
        *ffree_out = buf.f_ffree;
        memcpy(fsid_out, &buf.f_fsid,
               sizeof(buf.f_fsid) > fsid_size ? fsid_size :
               sizeof(buf.f_fsid));
        *namelen_out = buf.f_namelen;

        return 0;
}