libzfs_compat.c revision 297108 
1/*
2 * CDDL HEADER SART
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22/*
23 * Copyright (c) 2013 Martin Matuska <mm@FreeBSD.org>. All rights reserved.
24 */
25
26#include "libzfs_compat.h"
27
28int zfs_ioctl_version = ZFS_IOCVER_UNDEF;
29static int zfs_spa_version = -1;
30
31/*
32 * Get zfs_ioctl_version
33 */
34int
35get_zfs_ioctl_version(void)
36{
37	size_t ver_size;
38	int ver = ZFS_IOCVER_NONE;
39
40	ver_size = sizeof(ver);
41	sysctlbyname("vfs.zfs.version.ioctl", &ver, &ver_size, NULL, 0);
42
43	return (ver);
44}
45
46/*
47 * Get the SPA version
48 */
49static int
50get_zfs_spa_version(void)
51{
52	size_t ver_size;
53	int ver = 0;
54
55	ver_size = sizeof(ver);
56	sysctlbyname("vfs.zfs.version.spa", &ver, &ver_size, NULL, 0);
57
58	return (ver);
59}
60
61/*
62 * This is FreeBSD version of ioctl, because Solaris' ioctl() updates
63 * zc_nvlist_dst_size even if an error is returned, on FreeBSD if an
64 * error is returned zc_nvlist_dst_size won't be updated.
65 */
66int
67zcmd_ioctl(int fd, int request, zfs_cmd_t *zc)
68{
69	size_t oldsize;
70	int ret, cflag = ZFS_CMD_COMPAT_NONE;
71
72	if (zfs_ioctl_version == ZFS_IOCVER_UNDEF)
73		zfs_ioctl_version = get_zfs_ioctl_version();
74
75	if (zfs_ioctl_version >= ZFS_IOCVER_DEADMAN) {
76		switch (zfs_ioctl_version) {
77		case ZFS_IOCVER_RESUME:
78			cflag = ZFS_CMD_COMPAT_RESUME;
79			break;
80		case ZFS_IOCVER_EDBP:
81			cflag = ZFS_CMD_COMPAT_EDBP;
82			break;
83		case ZFS_IOCVER_ZCMD:
84			cflag = ZFS_CMD_COMPAT_ZCMD;
85			break;
86		case ZFS_IOCVER_LZC:
87			cflag = ZFS_CMD_COMPAT_LZC;
88			break;
89		case ZFS_IOCVER_DEADMAN:
90			cflag = ZFS_CMD_COMPAT_DEADMAN;
91			break;
92		}
93	} else {
94		/*
95		 * If vfs.zfs.version.ioctl is not defined, assume we have v28
96		 * compatible binaries and use vfs.zfs.version.spa to test for v15
97		 */
98		cflag = ZFS_CMD_COMPAT_V28;
99
100		if (zfs_spa_version < 0)
101			zfs_spa_version = get_zfs_spa_version();
102
103		if (zfs_spa_version == SPA_VERSION_15 ||
104		    zfs_spa_version == SPA_VERSION_14 ||
105		    zfs_spa_version == SPA_VERSION_13)
106			cflag = ZFS_CMD_COMPAT_V15;
107	}
108
109	oldsize = zc->zc_nvlist_dst_size;
110	ret = zcmd_ioctl_compat(fd, request, zc, cflag);
111
112	if (ret == 0 && oldsize < zc->zc_nvlist_dst_size) {
113		ret = -1;
114		errno = ENOMEM;
115	}
116
117	return (ret);
118}
119