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 60 static inline u32 *fh_fsid(const struct knfsd_fh *fh) 61 { 62 return (u32 *)&fh->fh_raw[4]; 63 } 64 65 static inline __u32 ino_t_to_u32(ino_t ino) 66 { 67 return (__u32) ino; 68 } 69 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 */ 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 } 196 197 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 * 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 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 * 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 } 250 251 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 } 260 261 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 */ 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 */ 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