1 /*
2  * JFFS2 -- Journalling Flash File System, Version 2.
3  *
4  * Copyright © 2001-2007 Red Hat, Inc.
5  * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
6  *
7  * Created by David Woodhouse <dwmw2@infradead.org>
8  *
9  * For licensing information, see the file 'LICENCE' in the
10  * jffs2 directory.
11  */
12 
13 #ifndef __LINUX_JFFS2_H__
14 #define __LINUX_JFFS2_H__
15 
16 #include <linux/types.h>
17 #include <linux/magic.h>
18 
19 /* You must include something which defines the C99 uintXX_t types.
20    We don't do it from here because this file is used in too many
21    different environments. */
22 
23 /* Values we may expect to find in the 'magic' field */
24 #define JFFS2_OLD_MAGIC_BITMASK 0x1984
25 #define JFFS2_MAGIC_BITMASK 0x1985
26 #define KSAMTIB_CIGAM_2SFFJ 0x8519 /* For detecting wrong-endian fs */
27 #define JFFS2_EMPTY_BITMASK 0xffff
28 #define JFFS2_DIRTY_BITMASK 0x0000
29 
30 /* Summary node MAGIC marker */
31 #define JFFS2_SUM_MAGIC	0x02851885
32 
33 /* We only allow a single char for length, and 0xFF is empty flash so
34    we don't want it confused with a real length. Hence max 254.
35 */
36 #define JFFS2_MAX_NAME_LEN 254
37 
38 /* How small can we sensibly write nodes? */
39 #define JFFS2_MIN_DATA_LEN 128
40 
41 #define JFFS2_COMPR_NONE	0x00
42 #define JFFS2_COMPR_ZERO	0x01
43 #define JFFS2_COMPR_RTIME	0x02
44 #define JFFS2_COMPR_RUBINMIPS	0x03
45 #define JFFS2_COMPR_COPY	0x04
46 #define JFFS2_COMPR_DYNRUBIN	0x05
47 #define JFFS2_COMPR_ZLIB	0x06
48 #define JFFS2_COMPR_LZO		0x07
49 /* Compatibility flags. */
50 #define JFFS2_COMPAT_MASK 0xc000      /* What do to if an unknown nodetype is found */
51 #define JFFS2_NODE_ACCURATE 0x2000
52 /* INCOMPAT: Fail to mount the filesystem */
53 #define JFFS2_FEATURE_INCOMPAT 0xc000
54 /* ROCOMPAT: Mount read-only */
55 #define JFFS2_FEATURE_ROCOMPAT 0x8000
56 /* RWCOMPAT_COPY: Mount read/write, and copy the node when it's GC'd */
57 #define JFFS2_FEATURE_RWCOMPAT_COPY 0x4000
58 /* RWCOMPAT_DELETE: Mount read/write, and delete the node when it's GC'd */
59 #define JFFS2_FEATURE_RWCOMPAT_DELETE 0x0000
60 
61 #define JFFS2_NODETYPE_DIRENT (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 1)
62 #define JFFS2_NODETYPE_INODE (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 2)
63 #define JFFS2_NODETYPE_CLEANMARKER (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
64 #define JFFS2_NODETYPE_PADDING (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 4)
65 
66 #define JFFS2_NODETYPE_SUMMARY (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 6)
67 
68 #define JFFS2_NODETYPE_XATTR (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 8)
69 #define JFFS2_NODETYPE_XREF (JFFS2_FEATURE_INCOMPAT | JFFS2_NODE_ACCURATE | 9)
70 
71 /* XATTR Related */
72 #define JFFS2_XPREFIX_USER		1	/* for "user." */
73 #define JFFS2_XPREFIX_SECURITY		2	/* for "security." */
74 #define JFFS2_XPREFIX_ACL_ACCESS	3	/* for "system.posix_acl_access" */
75 #define JFFS2_XPREFIX_ACL_DEFAULT	4	/* for "system.posix_acl_default" */
76 #define JFFS2_XPREFIX_TRUSTED		5	/* for "trusted.*" */
77 
78 #define JFFS2_ACL_VERSION		0x0001
79 
80 // Maybe later...
81 //#define JFFS2_NODETYPE_CHECKPOINT (JFFS2_FEATURE_RWCOMPAT_DELETE | JFFS2_NODE_ACCURATE | 3)
82 //#define JFFS2_NODETYPE_OPTIONS (JFFS2_FEATURE_RWCOMPAT_COPY | JFFS2_NODE_ACCURATE | 4)
83 
84 
85 #define JFFS2_INO_FLAG_PREREAD	  1	/* Do read_inode() for this one at
86 					   mount time, don't wait for it to
87 					   happen later */
88 #define JFFS2_INO_FLAG_USERCOMPR  2	/* User has requested a specific
89 					   compression type */
90 
91 
92 /* These can go once we've made sure we've caught all uses without
93    byteswapping */
94 
95 typedef struct {
96 	__u32 v32;
97 } __attribute__((packed)) jint32_t;
98 
99 typedef struct {
100 	__u32 m;
101 } __attribute__((packed)) jmode_t;
102 
103 typedef struct {
104 	__u16 v16;
105 } __attribute__((packed)) jint16_t;
106 
107 struct jffs2_unknown_node
108 {
109 	/* All start like this */
110 	jint16_t magic;
111 	jint16_t nodetype;
112 	jint32_t totlen; /* So we can skip over nodes we don't grok */
113 	jint32_t hdr_crc;
114 };
115 
116 struct jffs2_raw_dirent
117 {
118 	jint16_t magic;
119 	jint16_t nodetype;	/* == JFFS2_NODETYPE_DIRENT */
120 	jint32_t totlen;
121 	jint32_t hdr_crc;
122 	jint32_t pino;
123 	jint32_t version;
124 	jint32_t ino; /* == zero for unlink */
125 	jint32_t mctime;
126 	__u8 nsize;
127 	__u8 type;
128 	__u8 unused[2];
129 	jint32_t node_crc;
130 	jint32_t name_crc;
131 	__u8 name[0];
132 };
133 
134 /* The JFFS2 raw inode structure: Used for storage on physical media.  */
135 /* The uid, gid, atime, mtime and ctime members could be longer, but
136    are left like this for space efficiency. If and when people decide
137    they really need them extended, it's simple enough to add support for
138    a new type of raw node.
139 */
140 struct jffs2_raw_inode
141 {
142 	jint16_t magic;      /* A constant magic number.  */
143 	jint16_t nodetype;   /* == JFFS2_NODETYPE_INODE */
144 	jint32_t totlen;     /* Total length of this node (inc data, etc.) */
145 	jint32_t hdr_crc;
146 	jint32_t ino;        /* Inode number.  */
147 	jint32_t version;    /* Version number.  */
148 	jmode_t mode;       /* The file's type or mode.  */
149 	jint16_t uid;        /* The file's owner.  */
150 	jint16_t gid;        /* The file's group.  */
151 	jint32_t isize;      /* Total resultant size of this inode (used for truncations)  */
152 	jint32_t atime;      /* Last access time.  */
153 	jint32_t mtime;      /* Last modification time.  */
154 	jint32_t ctime;      /* Change time.  */
155 	jint32_t offset;     /* Where to begin to write.  */
156 	jint32_t csize;      /* (Compressed) data size */
157 	jint32_t dsize;	     /* Size of the node's data. (after decompression) */
158 	__u8 compr;       /* Compression algorithm used */
159 	__u8 usercompr;   /* Compression algorithm requested by the user */
160 	jint16_t flags;	     /* See JFFS2_INO_FLAG_* */
161 	jint32_t data_crc;   /* CRC for the (compressed) data.  */
162 	jint32_t node_crc;   /* CRC for the raw inode (excluding data)  */
163 	__u8 data[0];
164 };
165 
166 struct jffs2_raw_xattr {
167 	jint16_t magic;
168 	jint16_t nodetype;	/* = JFFS2_NODETYPE_XATTR */
169 	jint32_t totlen;
170 	jint32_t hdr_crc;
171 	jint32_t xid;		/* XATTR identifier number */
172 	jint32_t version;
173 	__u8 xprefix;
174 	__u8 name_len;
175 	jint16_t value_len;
176 	jint32_t data_crc;
177 	jint32_t node_crc;
178 	__u8 data[0];
179 } __attribute__((packed));
180 
181 struct jffs2_raw_xref
182 {
183 	jint16_t magic;
184 	jint16_t nodetype;	/* = JFFS2_NODETYPE_XREF */
185 	jint32_t totlen;
186 	jint32_t hdr_crc;
187 	jint32_t ino;		/* inode number */
188 	jint32_t xid;		/* XATTR identifier number */
189 	jint32_t xseqno;	/* xref sequential number */
190 	jint32_t node_crc;
191 } __attribute__((packed));
192 
193 struct jffs2_raw_summary
194 {
195 	jint16_t magic;
196 	jint16_t nodetype; 	/* = JFFS2_NODETYPE_SUMMARY */
197 	jint32_t totlen;
198 	jint32_t hdr_crc;
199 	jint32_t sum_num;	/* number of sum entries*/
200 	jint32_t cln_mkr;	/* clean marker size, 0 = no cleanmarker */
201 	jint32_t padded;	/* sum of the size of padding nodes */
202 	jint32_t sum_crc;	/* summary information crc */
203 	jint32_t node_crc; 	/* node crc */
204 	jint32_t sum[0]; 	/* inode summary info */
205 };
206 
207 union jffs2_node_union
208 {
209 	struct jffs2_raw_inode i;
210 	struct jffs2_raw_dirent d;
211 	struct jffs2_raw_xattr x;
212 	struct jffs2_raw_xref r;
213 	struct jffs2_raw_summary s;
214 	struct jffs2_unknown_node u;
215 };
216 
217 /* Data payload for device nodes. */
218 union jffs2_device_node {
219 	jint16_t old_id;
220 	jint32_t new_id;
221 };
222 
223 #endif /* __LINUX_JFFS2_H__ */
224