1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
4 *
5 * This file describes the layout of the file handles as passed
6 * over the wire.
7 */
8 #ifndef _LINUX_NFSD_NFSFH_H
9 #define _LINUX_NFSD_NFSFH_H
10
11 #include <linux/crc32.h>
12 #include <linux/sunrpc/svc.h>
13 #include <linux/iversion.h>
14 #include <linux/exportfs.h>
15 #include <linux/nfs4.h>
16
17 /*
18 * The file handle starts with a sequence of four-byte words.
19 * The first word contains a version number (1) and three descriptor bytes
20 * that tell how the remaining 3 variable length fields should be handled.
21 * These three bytes are auth_type, fsid_type and fileid_type.
22 *
23 * All four-byte values are in host-byte-order.
24 *
25 * The auth_type field is deprecated and must be set to 0.
26 *
27 * The fsid_type identifies how the filesystem (or export point) is
28 * encoded.
29 * Current values:
30 * 0 - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number
31 * NOTE: we cannot use the kdev_t device id value, because kdev_t.h
32 * says we mustn't. We must break it up and reassemble.
33 * 1 - 4 byte user specified identifier
34 * 2 - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED
35 * 3 - 4 byte device id, encoded for user-space, 4 byte inode number
36 * 4 - 4 byte inode number and 4 byte uuid
37 * 5 - 8 byte uuid
38 * 6 - 16 byte uuid
39 * 7 - 8 byte inode number and 16 byte uuid
40 *
41 * The fileid_type identifies how the file within the filesystem is encoded.
42 * The values for this field are filesystem specific, exccept that
43 * filesystems must not use the values '0' or '0xff'. 'See enum fid_type'
44 * in include/linux/exportfs.h for currently registered values.
45 */
46
47 struct knfsd_fh {
48 unsigned int fh_size; /*
49 * Points to the current size while
50 * building a new file handle.
51 */
52 u8 fh_raw[NFS4_FHSIZE];
53 };
54
55 #define fh_version fh_raw[0]
56 #define fh_auth_type fh_raw[1]
57 #define fh_fsid_type fh_raw[2]
58 #define fh_fileid_type fh_raw[3]
59
fh_fsid(const struct knfsd_fh * fh)60 static inline u32 *fh_fsid(const struct knfsd_fh *fh)
61 {
62 return (u32 *)&fh->fh_raw[4];
63 }
64
ino_t_to_u32(ino_t ino)65 static inline __u32 ino_t_to_u32(ino_t ino)
66 {
67 return (__u32) ino;
68 }
69
u32_to_ino_t(__u32 uino)70 static inline ino_t u32_to_ino_t(__u32 uino)
71 {
72 return (ino_t) uino;
73 }
74
75 /*
76 * This is the internal representation of an NFS handle used in knfsd.
77 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3.
78 */
79 typedef struct svc_fh {
80 struct knfsd_fh fh_handle; /* FH data */
81 int fh_maxsize; /* max size for fh_handle */
82 struct dentry * fh_dentry; /* validated dentry */
83 struct svc_export * fh_export; /* export pointer */
84
85 bool fh_want_write; /* remount protection taken */
86 bool fh_no_wcc; /* no wcc data needed */
87 bool fh_no_atomic_attr;
88 /*
89 * wcc data is not atomic with
90 * operation
91 */
92 bool fh_use_wgather; /* NFSv2 wgather option */
93 bool fh_64bit_cookies;/* readdir cookie size */
94 int fh_flags; /* FH flags */
95 bool fh_post_saved; /* post-op attrs saved */
96 bool fh_pre_saved; /* pre-op attrs saved */
97
98 /* Pre-op attributes saved when inode is locked */
99 __u64 fh_pre_size; /* size before operation */
100 struct timespec64 fh_pre_mtime; /* mtime before oper */
101 struct timespec64 fh_pre_ctime; /* ctime before oper */
102 /*
103 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode)
104 * to find out if it is valid.
105 */
106 u64 fh_pre_change;
107
108 /* Post-op attributes saved in fh_fill_post_attrs() */
109 struct kstat fh_post_attr; /* full attrs after operation */
110 u64 fh_post_change; /* nfsv4 change; see above */
111 } svc_fh;
112 #define NFSD4_FH_FOREIGN (1<<0)
113 #define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f))
114 #define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f))
115
116 enum nfsd_fsid {
117 FSID_DEV = 0,
118 FSID_NUM,
119 FSID_MAJOR_MINOR,
120 FSID_ENCODE_DEV,
121 FSID_UUID4_INUM,
122 FSID_UUID8,
123 FSID_UUID16,
124 FSID_UUID16_INUM,
125 };
126
127 enum fsid_source {
128 FSIDSOURCE_DEV,
129 FSIDSOURCE_FSID,
130 FSIDSOURCE_UUID,
131 };
132 extern enum fsid_source fsid_source(const struct svc_fh *fhp);
133
134
135 /*
136 * This might look a little large to "inline" but in all calls except
137 * one, 'vers' is constant so moste of the function disappears.
138 *
139 * In some cases the values are considered to be host endian and in
140 * others, net endian. fsidv is always considered to be u32 as the
141 * callers don't know which it will be. So we must use __force to keep
142 * sparse from complaining. Since these values are opaque to the
143 * client, that shouldn't be a problem.
144 */
mk_fsid(int vers,u32 * fsidv,dev_t dev,ino_t ino,u32 fsid,unsigned char * uuid)145 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino,
146 u32 fsid, unsigned char *uuid)
147 {
148 u32 *up;
149 switch(vers) {
150 case FSID_DEV:
151 fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) |
152 MINOR(dev));
153 fsidv[1] = ino_t_to_u32(ino);
154 break;
155 case FSID_NUM:
156 fsidv[0] = fsid;
157 break;
158 case FSID_MAJOR_MINOR:
159 fsidv[0] = (__force __u32)htonl(MAJOR(dev));
160 fsidv[1] = (__force __u32)htonl(MINOR(dev));
161 fsidv[2] = ino_t_to_u32(ino);
162 break;
163
164 case FSID_ENCODE_DEV:
165 fsidv[0] = new_encode_dev(dev);
166 fsidv[1] = ino_t_to_u32(ino);
167 break;
168
169 case FSID_UUID4_INUM:
170 /* 4 byte fsid and inode number */
171 up = (u32*)uuid;
172 fsidv[0] = ino_t_to_u32(ino);
173 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3];
174 break;
175
176 case FSID_UUID8:
177 /* 8 byte fsid */
178 up = (u32*)uuid;
179 fsidv[0] = up[0] ^ up[2];
180 fsidv[1] = up[1] ^ up[3];
181 break;
182
183 case FSID_UUID16:
184 /* 16 byte fsid - NFSv3+ only */
185 memcpy(fsidv, uuid, 16);
186 break;
187
188 case FSID_UUID16_INUM:
189 /* 8 byte inode and 16 byte fsid */
190 *(u64*)fsidv = (u64)ino;
191 memcpy(fsidv+2, uuid, 16);
192 break;
193 default: BUG();
194 }
195 }
196
key_len(int type)197 static inline int key_len(int type)
198 {
199 switch(type) {
200 case FSID_DEV: return 8;
201 case FSID_NUM: return 4;
202 case FSID_MAJOR_MINOR: return 12;
203 case FSID_ENCODE_DEV: return 8;
204 case FSID_UUID4_INUM: return 8;
205 case FSID_UUID8: return 8;
206 case FSID_UUID16: return 16;
207 case FSID_UUID16_INUM: return 24;
208 default: return 0;
209 }
210 }
211
212 /*
213 * Shorthand for dprintk()'s
214 */
215 extern char * SVCFH_fmt(struct svc_fh *fhp);
216
217 /*
218 * Function prototypes
219 */
220 __be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int);
221 __be32 fh_verify_local(struct net *, struct svc_cred *, struct auth_domain *,
222 struct svc_fh *, umode_t, int);
223 __be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *);
224 __be32 fh_update(struct svc_fh *);
225 void fh_put(struct svc_fh *);
226
227 static __inline__ struct svc_fh *
fh_copy(struct svc_fh * dst,const struct svc_fh * src)228 fh_copy(struct svc_fh *dst, const struct svc_fh *src)
229 {
230 WARN_ON(src->fh_dentry);
231
232 *dst = *src;
233 return dst;
234 }
235
236 static inline void
fh_copy_shallow(struct knfsd_fh * dst,const struct knfsd_fh * src)237 fh_copy_shallow(struct knfsd_fh *dst, const struct knfsd_fh *src)
238 {
239 dst->fh_size = src->fh_size;
240 memcpy(&dst->fh_raw, &src->fh_raw, src->fh_size);
241 }
242
243 static __inline__ struct svc_fh *
fh_init(struct svc_fh * fhp,int maxsize)244 fh_init(struct svc_fh *fhp, int maxsize)
245 {
246 memset(fhp, 0, sizeof(*fhp));
247 fhp->fh_maxsize = maxsize;
248 return fhp;
249 }
250
fh_match(const struct knfsd_fh * fh1,const struct knfsd_fh * fh2)251 static inline bool fh_match(const struct knfsd_fh *fh1,
252 const struct knfsd_fh *fh2)
253 {
254 if (fh1->fh_size != fh2->fh_size)
255 return false;
256 if (memcmp(fh1->fh_raw, fh2->fh_raw, fh1->fh_size) != 0)
257 return false;
258 return true;
259 }
260
fh_fsid_match(const struct knfsd_fh * fh1,const struct knfsd_fh * fh2)261 static inline bool fh_fsid_match(const struct knfsd_fh *fh1,
262 const struct knfsd_fh *fh2)
263 {
264 u32 *fsid1 = fh_fsid(fh1);
265 u32 *fsid2 = fh_fsid(fh2);
266
267 if (fh1->fh_fsid_type != fh2->fh_fsid_type)
268 return false;
269 if (memcmp(fsid1, fsid2, key_len(fh1->fh_fsid_type)) != 0)
270 return false;
271 return true;
272 }
273
274 /**
275 * knfsd_fh_hash - calculate the crc32 hash for the filehandle
276 * @fh - pointer to filehandle
277 *
278 * returns a crc32 hash for the filehandle that is compatible with
279 * the one displayed by "wireshark".
280 */
knfsd_fh_hash(const struct knfsd_fh * fh)281 static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh)
282 {
283 return ~crc32_le(0xFFFFFFFF, fh->fh_raw, fh->fh_size);
284 }
285
286 /**
287 * fh_clear_pre_post_attrs - Reset pre/post attributes
288 * @fhp: file handle to be updated
289 *
290 */
fh_clear_pre_post_attrs(struct svc_fh * fhp)291 static inline void fh_clear_pre_post_attrs(struct svc_fh *fhp)
292 {
293 fhp->fh_post_saved = false;
294 fhp->fh_pre_saved = false;
295 }
296
297 u64 nfsd4_change_attribute(const struct kstat *stat);
298 __be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp);
299 __be32 fh_fill_post_attrs(struct svc_fh *fhp);
300 __be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp);
301 #endif /* _LINUX_NFSD_NFSFH_H */
302