xref: /illumos-gate/usr/src/uts/common/sys/lofi.h (revision 3d393ee6c37fa10ac512ed6d36109ad616dc7c1a)
1 /*
2  * CDDL HEADER START
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  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 
27 #ifndef	_SYS_LOFI_H
28 #define	_SYS_LOFI_H
29 
30 #include <sys/types.h>
31 #include <sys/time.h>
32 #include <sys/taskq.h>
33 #include <sys/vtoc.h>
34 #include <sys/dkio.h>
35 #include <sys/vnode.h>
36 #include <sys/crypto/api.h>
37 
38 #ifdef	__cplusplus
39 extern "C" {
40 #endif
41 
42 /*
43  * /dev names:
44  *	/dev/lofictl	- master control device
45  *	/dev/lofi	- block devices, named by minor number
46  *	/dev/rlofi	- character devices, named by minor number
47  */
48 #define	LOFI_DRIVER_NAME	"lofi"
49 #define	LOFI_CTL_NODE		"ctl"
50 #define	LOFI_CTL_NAME		LOFI_DRIVER_NAME LOFI_CTL_NODE
51 #define	LOFI_BLOCK_NAME		LOFI_DRIVER_NAME
52 #define	LOFI_CHAR_NAME		"r" LOFI_DRIVER_NAME
53 
54 #define	SEGHDR		1
55 #define	COMPRESSED	1
56 #define	UNCOMPRESSED	0
57 #define	MAXALGLEN	36
58 
59 /*
60  *
61  * Use is:
62  *	ld = open("/dev/lofictl", O_RDWR | O_EXCL);
63  *
64  * lofi must be opened exclusively. Access is controlled by permissions on
65  * the device, which is 644 by default. Write-access is required for ioctls
66  * that change state, but only read-access is required for the ioctls that
67  * return information. Basically, only root can add and remove files, but
68  * non-root can look at the current lists.
69  *
70  * ioctl usage:
71  *
72  * kernel ioctls
73  *
74  *	strcpy(li.li_filename, "somefilename");
75  *	ioctl(ld, LOFI_MAP_FILE, &li);
76  *	newminor = li.li_minor;
77  *
78  *	strcpy(li.li_filename, "somefilename");
79  *	ioctl(ld, LOFI_UNMAP_FILE, &li);
80  *
81  *	strcpy(li.li_filename, "somefilename");
82  *	li.li_minor = minor_number;
83  *	ioctl(ld, LOFI_MAP_FILE_MINOR, &li);
84  *
85  *	li.li_minor = minor_number;
86  *	ioctl(ld, LOFI_UNMAP_FILE_MINOR, &li);
87  *
88  *	li.li_minor = minor_number;
89  *	ioctl(ld, LOFI_GET_FILENAME, &li);
90  *	filename = li.li_filename;
91  *	encrypted = li.li_crypto_enabled;
92  *
93  *	strcpy(li.li_filename, "somefilename");
94  *	ioctl(ld, LOFI_GET_MINOR, &li);
95  *	minor = li.li_minor;
96  *
97  *	li.li_minor = 0;
98  *	ioctl(ld, LOFI_GET_MAXMINOR, &li);
99  *	maxminor = li.li_minor;
100  *
101  *	strcpy(li.li_filename, "somefilename");
102  *	li.li_minor = 0;
103  *	ioctl(ld, LOFI_CHECK_COMPRESSED, &li);
104  *
105  * If the 'li_force' flag is set for any of the LOFI_UNMAP_* commands, then if
106  * the device is busy, the underlying vnode will be closed, and any subsequent
107  * operations will fail.  It will behave as if the device had been forcibly
108  * removed, so the DKIOCSTATE ioctl will return DKIO_DEV_GONE.  When the device
109  * is last closed, it will be torn down.
110  *
111  * If the 'li_cleanup' flag is set for any of the LOFI_UNMAP_* commands, then
112  * if the device is busy, it is marked for removal at the next time it is
113  * no longer held open by anybody.  When the device is last closed, it will be
114  * torn down.
115  *
116  * Oh, and last but not least: these ioctls are totally private and only
117  * for use by lofiadm(1M).
118  *
119  */
120 
121 typedef enum	iv_method {
122 	IVM_NONE,	/* no iv needed, iv is null */
123 	IVM_ENC_BLKNO	/* iv is logical block no. encrypted */
124 } iv_method_t;
125 
126 struct lofi_ioctl {
127 	uint32_t 	li_minor;
128 	boolean_t	li_force;
129 	boolean_t	li_cleanup;
130 	char	li_filename[MAXPATHLEN];
131 
132 	/* the following fields are required for compression support */
133 	char	li_algorithm[MAXALGLEN];
134 
135 	/* the following fields are required for encryption support */
136 	boolean_t	li_crypto_enabled;
137 	crypto_mech_name_t	li_cipher;	/* for data */
138 	uint32_t	li_key_len;		/* for data */
139 	char		li_key[56];	/* for data: max 448-bit Blowfish key */
140 	crypto_mech_name_t	li_iv_cipher;	/* for iv derivation */
141 	uint32_t	li_iv_len;		/* for iv derivation */
142 	iv_method_t	li_iv_type;		/* for iv derivation */
143 };
144 
145 #define	LOFI_IOC_BASE		(('L' << 16) | ('F' << 8))
146 
147 #define	LOFI_MAP_FILE		(LOFI_IOC_BASE | 0x01)
148 #define	LOFI_MAP_FILE_MINOR	(LOFI_IOC_BASE | 0x02)
149 #define	LOFI_UNMAP_FILE		(LOFI_IOC_BASE | 0x03)
150 #define	LOFI_UNMAP_FILE_MINOR	(LOFI_IOC_BASE | 0x04)
151 #define	LOFI_GET_FILENAME	(LOFI_IOC_BASE | 0x05)
152 #define	LOFI_GET_MINOR		(LOFI_IOC_BASE | 0x06)
153 #define	LOFI_GET_MAXMINOR	(LOFI_IOC_BASE | 0x07)
154 #define	LOFI_CHECK_COMPRESSED	(LOFI_IOC_BASE | 0x08)
155 
156 /*
157  * file types that might be usable with lofi, maybe. Only regular
158  * files are documented though.
159  */
160 #define	S_ISLOFIABLE(mode) \
161 	(S_ISREG(mode) || S_ISBLK(mode) || S_ISCHR(mode))
162 
163 #if defined(_KERNEL)
164 
165 /*
166  * We limit the maximum number of active lofi devices to 128, which seems very
167  * large. You can tune this by changing lofi_max_files in /etc/system.
168  * If you change it dynamically, which you probably shouldn't do, make sure
169  * to only _increase_ it.
170  */
171 #define	LOFI_MAX_FILES	128
172 extern uint32_t lofi_max_files;
173 
174 #define	V_ISLOFIABLE(vtype) \
175 	((vtype == VREG) || (vtype == VBLK) || (vtype == VCHR))
176 
177 /*
178  * Need exactly 6 bytes to identify encrypted lofi image
179  */
180 extern const char lofi_crypto_magic[6];
181 #define	LOFI_CRYPTO_MAGIC	{ 'C', 'F', 'L', 'O', 'F', 'I' }
182 #define	LOFI_CRYPTO_VERSION	((uint16_t)0)
183 #define	LOFI_CRYPTO_DATA_SECTOR	((uint32_t)16)		/* for version 0 */
184 
185 /*
186  * Crypto metadata for encrypted lofi images
187  * The fields here only satisfy initial implementation requirements.
188  */
189 struct crypto_meta {
190 	char		magic[6];		/* LOFI_CRYPTO_MAGIC */
191 	uint16_t	version;		/* version of encrypted lofi */
192 	char		reserved1[96];		/* future use */
193 	uint32_t	data_sector;		/* start of data area */
194 	char		pad[404];		/* end on DEV_BSIZE bdry */
195 	/* second header block is not defined at this time */
196 };
197 
198 struct lofi_state {
199 	char		*ls_filename;	/* filename to open */
200 	size_t		ls_filename_sz;
201 	struct vnode	*ls_vp;		/* open vnode */
202 	kmutex_t	ls_vp_lock;	/* protects ls_vp */
203 	kcondvar_t	ls_vp_cv;	/* signal changes to ls_vp */
204 	uint32_t	ls_vp_iocount;	/* # pending I/O requests */
205 	boolean_t	ls_vp_closereq;	/* force close requested */
206 	u_offset_t	ls_vp_size;
207 	uint32_t	ls_blk_open;
208 	uint32_t	ls_chr_open;
209 	uint32_t	ls_lyr_open_count;
210 	int		ls_openflag;
211 	boolean_t	ls_cleanup;	/* cleanup on close */
212 	taskq_t		*ls_taskq;
213 	kstat_t		*ls_kstat;
214 	kmutex_t	ls_kstat_lock;
215 	struct dk_geom	ls_dkg;
216 	struct vtoc	ls_vtoc;
217 	struct dk_cinfo	ls_ci;
218 
219 	/* the following fields are required for compression support */
220 	int		ls_comp_algorithm_index; /* idx into compress_table */
221 	char		ls_comp_algorithm[MAXALGLEN];
222 	uint32_t	ls_uncomp_seg_sz; /* sz of uncompressed segment */
223 	uint32_t	ls_comp_index_sz; /* number of index entries */
224 	uint32_t	ls_comp_seg_shift; /* exponent for byte shift */
225 	uint32_t	ls_uncomp_last_seg_sz; /* sz of last uncomp segment */
226 	uint64_t	ls_comp_offbase; /* offset of actual compressed data */
227 	uint64_t	*ls_comp_seg_index; /* array of index entries */
228 	caddr_t		ls_comp_index_data; /* index pages loaded from file */
229 	uint32_t	ls_comp_index_data_sz;
230 	u_offset_t	ls_vp_comp_size; /* actual compressed file size */
231 
232 	/* the following fields are required for encryption support */
233 	boolean_t		ls_crypto_enabled;
234 	u_offset_t		ls_crypto_offset;	/* crypto meta size */
235 	struct crypto_meta	ls_crypto;
236 	crypto_mechanism_t	ls_mech;	/* for data encr/decr */
237 	crypto_key_t		ls_key;		/* for data encr/decr */
238 	crypto_mechanism_t	ls_iv_mech;	/* for iv derivation */
239 	size_t			ls_iv_len;	/* for iv derivation */
240 	iv_method_t		ls_iv_type;	/* for iv derivation */
241 	kmutex_t		ls_crypto_lock;
242 	crypto_ctx_template_t	ls_ctx_tmpl;
243 
244 };
245 
246 #endif	/* _KERNEL */
247 
248 /*
249  * Common signature for all lofi compress functions
250  */
251 typedef int lofi_compress_func_t(void *src, size_t srclen, void *dst,
252 	size_t *destlen, int level);
253 
254 /*
255  * Information about each compression function
256  */
257 typedef struct lofi_compress_info {
258 	lofi_compress_func_t	*l_decompress;
259 	lofi_compress_func_t	*l_compress;
260 	int			l_level;
261 	char			*l_name;	/* algorithm name */
262 } lofi_compress_info_t;
263 
264 enum lofi_compress {
265 	LOFI_COMPRESS_GZIP = 0,
266 	LOFI_COMPRESS_GZIP_6 = 1,
267 	LOFI_COMPRESS_GZIP_9 = 2,
268 	LOFI_COMPRESS_FUNCTIONS
269 };
270 
271 #ifdef	__cplusplus
272 }
273 #endif
274 
275 #endif	/* _SYS_LOFI_H */
276