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 union { 53 char fh_raw[NFS4_FHSIZE]; 54 struct { 55 u8 fh_version; /* == 1 */ 56 u8 fh_auth_type; /* deprecated */ 57 u8 fh_fsid_type; 58 u8 fh_fileid_type; 59 u32 fh_fsid[]; /* flexible-array member */ 60 }; 61 }; 62 }; 63 ino_t_to_u32(ino_t ino)64 static inline __u32 ino_t_to_u32(ino_t ino) 65 { 66 return (__u32) ino; 67 } 68 u32_to_ino_t(__u32 uino)69 static inline ino_t u32_to_ino_t(__u32 uino) 70 { 71 return (ino_t) uino; 72 } 73 74 /* 75 * This is the internal representation of an NFS handle used in knfsd. 76 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3. 77 */ 78 typedef struct svc_fh { 79 struct knfsd_fh fh_handle; /* FH data */ 80 int fh_maxsize; /* max size for fh_handle */ 81 struct dentry * fh_dentry; /* validated dentry */ 82 struct svc_export * fh_export; /* export pointer */ 83 84 bool fh_want_write; /* remount protection taken */ 85 bool fh_no_wcc; /* no wcc data needed */ 86 bool fh_no_atomic_attr; 87 /* 88 * wcc data is not atomic with 89 * operation 90 */ 91 bool fh_use_wgather; /* NFSv2 wgather option */ 92 bool fh_64bit_cookies;/* readdir cookie size */ 93 int fh_flags; /* FH flags */ 94 bool fh_post_saved; /* post-op attrs saved */ 95 bool fh_pre_saved; /* pre-op attrs saved */ 96 97 /* Pre-op attributes saved when inode is locked */ 98 __u64 fh_pre_size; /* size before operation */ 99 struct timespec64 fh_pre_mtime; /* mtime before oper */ 100 struct timespec64 fh_pre_ctime; /* ctime before oper */ 101 /* 102 * pre-op nfsv4 change attr: note must check IS_I_VERSION(inode) 103 * to find out if it is valid. 104 */ 105 u64 fh_pre_change; 106 107 /* Post-op attributes saved in fh_fill_post_attrs() */ 108 struct kstat fh_post_attr; /* full attrs after operation */ 109 u64 fh_post_change; /* nfsv4 change; see above */ 110 } svc_fh; 111 #define NFSD4_FH_FOREIGN (1<<0) 112 #define SET_FH_FLAG(c, f) ((c)->fh_flags |= (f)) 113 #define HAS_FH_FLAG(c, f) ((c)->fh_flags & (f)) 114 115 enum nfsd_fsid { 116 FSID_DEV = 0, 117 FSID_NUM, 118 FSID_MAJOR_MINOR, 119 FSID_ENCODE_DEV, 120 FSID_UUID4_INUM, 121 FSID_UUID8, 122 FSID_UUID16, 123 FSID_UUID16_INUM, 124 }; 125 126 enum fsid_source { 127 FSIDSOURCE_DEV, 128 FSIDSOURCE_FSID, 129 FSIDSOURCE_UUID, 130 }; 131 extern enum fsid_source fsid_source(const struct svc_fh *fhp); 132 133 134 /* 135 * This might look a little large to "inline" but in all calls except 136 * one, 'vers' is constant so moste of the function disappears. 137 * 138 * In some cases the values are considered to be host endian and in 139 * others, net endian. fsidv is always considered to be u32 as the 140 * callers don't know which it will be. So we must use __force to keep 141 * sparse from complaining. Since these values are opaque to the 142 * client, that shouldn't be a problem. 143 */ mk_fsid(int vers,u32 * fsidv,dev_t dev,ino_t ino,u32 fsid,unsigned char * uuid)144 static inline void mk_fsid(int vers, u32 *fsidv, dev_t dev, ino_t ino, 145 u32 fsid, unsigned char *uuid) 146 { 147 u32 *up; 148 switch(vers) { 149 case FSID_DEV: 150 fsidv[0] = (__force __u32)htonl((MAJOR(dev)<<16) | 151 MINOR(dev)); 152 fsidv[1] = ino_t_to_u32(ino); 153 break; 154 case FSID_NUM: 155 fsidv[0] = fsid; 156 break; 157 case FSID_MAJOR_MINOR: 158 fsidv[0] = (__force __u32)htonl(MAJOR(dev)); 159 fsidv[1] = (__force __u32)htonl(MINOR(dev)); 160 fsidv[2] = ino_t_to_u32(ino); 161 break; 162 163 case FSID_ENCODE_DEV: 164 fsidv[0] = new_encode_dev(dev); 165 fsidv[1] = ino_t_to_u32(ino); 166 break; 167 168 case FSID_UUID4_INUM: 169 /* 4 byte fsid and inode number */ 170 up = (u32*)uuid; 171 fsidv[0] = ino_t_to_u32(ino); 172 fsidv[1] = up[0] ^ up[1] ^ up[2] ^ up[3]; 173 break; 174 175 case FSID_UUID8: 176 /* 8 byte fsid */ 177 up = (u32*)uuid; 178 fsidv[0] = up[0] ^ up[2]; 179 fsidv[1] = up[1] ^ up[3]; 180 break; 181 182 case FSID_UUID16: 183 /* 16 byte fsid - NFSv3+ only */ 184 memcpy(fsidv, uuid, 16); 185 break; 186 187 case FSID_UUID16_INUM: 188 /* 8 byte inode and 16 byte fsid */ 189 *(u64*)fsidv = (u64)ino; 190 memcpy(fsidv+2, uuid, 16); 191 break; 192 default: BUG(); 193 } 194 } 195 key_len(int type)196 static inline int key_len(int type) 197 { 198 switch(type) { 199 case FSID_DEV: return 8; 200 case FSID_NUM: return 4; 201 case FSID_MAJOR_MINOR: return 12; 202 case FSID_ENCODE_DEV: return 8; 203 case FSID_UUID4_INUM: return 8; 204 case FSID_UUID8: return 8; 205 case FSID_UUID16: return 16; 206 case FSID_UUID16_INUM: return 24; 207 default: return 0; 208 } 209 } 210 211 /* 212 * Shorthand for dprintk()'s 213 */ 214 extern char * SVCFH_fmt(struct svc_fh *fhp); 215 216 /* 217 * Function prototypes 218 */ 219 __be32 fh_verify(struct svc_rqst *, struct svc_fh *, umode_t, int); 220 __be32 fh_verify_local(struct net *, struct svc_cred *, struct auth_domain *, 221 struct svc_fh *, umode_t, int); 222 __be32 fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *); 223 __be32 fh_update(struct svc_fh *); 224 void fh_put(struct svc_fh *); 225 226 static __inline__ struct svc_fh * fh_copy(struct svc_fh * dst,const struct svc_fh * src)227 fh_copy(struct svc_fh *dst, const struct svc_fh *src) 228 { 229 WARN_ON(src->fh_dentry); 230 231 *dst = *src; 232 return dst; 233 } 234 235 static inline void fh_copy_shallow(struct knfsd_fh * dst,const struct knfsd_fh * src)236 fh_copy_shallow(struct knfsd_fh *dst, const struct knfsd_fh *src) 237 { 238 dst->fh_size = src->fh_size; 239 memcpy(&dst->fh_raw, &src->fh_raw, src->fh_size); 240 } 241 242 static __inline__ struct svc_fh * fh_init(struct svc_fh * fhp,int maxsize)243 fh_init(struct svc_fh *fhp, int maxsize) 244 { 245 memset(fhp, 0, sizeof(*fhp)); 246 fhp->fh_maxsize = maxsize; 247 return fhp; 248 } 249 fh_match(const struct knfsd_fh * fh1,const struct knfsd_fh * fh2)250 static inline bool fh_match(const struct knfsd_fh *fh1, 251 const struct knfsd_fh *fh2) 252 { 253 if (fh1->fh_size != fh2->fh_size) 254 return false; 255 if (memcmp(fh1->fh_raw, fh2->fh_raw, fh1->fh_size) != 0) 256 return false; 257 return true; 258 } 259 fh_fsid_match(const struct knfsd_fh * fh1,const struct knfsd_fh * fh2)260 static inline bool fh_fsid_match(const struct knfsd_fh *fh1, 261 const struct knfsd_fh *fh2) 262 { 263 if (fh1->fh_fsid_type != fh2->fh_fsid_type) 264 return false; 265 if (memcmp(fh1->fh_fsid, fh2->fh_fsid, key_len(fh1->fh_fsid_type)) != 0) 266 return false; 267 return true; 268 } 269 270 #ifdef CONFIG_CRC32 271 /** 272 * knfsd_fh_hash - calculate the crc32 hash for the filehandle 273 * @fh - pointer to filehandle 274 * 275 * returns a crc32 hash for the filehandle that is compatible with 276 * the one displayed by "wireshark". 277 */ knfsd_fh_hash(const struct knfsd_fh * fh)278 static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh) 279 { 280 return ~crc32_le(0xFFFFFFFF, fh->fh_raw, fh->fh_size); 281 } 282 #else knfsd_fh_hash(const struct knfsd_fh * fh)283 static inline u32 knfsd_fh_hash(const struct knfsd_fh *fh) 284 { 285 return 0; 286 } 287 #endif 288 289 /** 290 * fh_clear_pre_post_attrs - Reset pre/post attributes 291 * @fhp: file handle to be updated 292 * 293 */ fh_clear_pre_post_attrs(struct svc_fh * fhp)294 static inline void fh_clear_pre_post_attrs(struct svc_fh *fhp) 295 { 296 fhp->fh_post_saved = false; 297 fhp->fh_pre_saved = false; 298 } 299 300 u64 nfsd4_change_attribute(const struct kstat *stat, 301 const struct inode *inode); 302 __be32 __must_check fh_fill_pre_attrs(struct svc_fh *fhp); 303 __be32 fh_fill_post_attrs(struct svc_fh *fhp); 304 __be32 __must_check fh_fill_both_attrs(struct svc_fh *fhp); 305 #endif /* _LINUX_NFSD_NFSFH_H */ 306