1 /* 2 * include/linux/nfsd/nfsfh.h 3 * 4 * This file describes the layout of the file handles as passed 5 * over the wire. 6 * 7 * Earlier versions of knfsd used to sign file handles using keyed MD5 8 * or SHA. I've removed this code, because it doesn't give you more 9 * security than blocking external access to port 2049 on your firewall. 10 * 11 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir (at) monad.swb.de> 12 */ 13 14 #ifndef _LINUX_NFSD_FH_H 15 #define _LINUX_NFSD_FH_H 16 17 #include <asm/types.h> 18 #ifdef __KERNEL__ 19 # include <linux/types.h> 20 # include <linux/string.h> 21 # include <linux/fs.h> 22 #endif 23 #include <linux/nfsd/const.h> 24 #include <linux/nfsd/debug.h> 25 26 /* 27 * This is the old "dentry style" Linux NFSv2 file handle. 28 * 29 * The xino and xdev fields are currently used to transport the 30 * ino/dev of the exported inode. 31 */ 32 struct nfs_fhbase_old { 33 __u32 fb_dcookie; /* dentry cookie - always 0xfeebbaca */ 34 __u32 fb_ino; /* our inode number */ 35 __u32 fb_dirino; /* dir inode number, 0 for directories */ 36 __u32 fb_dev; /* our device */ 37 __u32 fb_xdev; 38 __u32 fb_xino; 39 __u32 fb_generation; 40 }; 41 42 /* 43 * This is the new flexible, extensible style NFSv2/v3 file handle. 44 * by Neil Brown <neilb (at) cse.unsw.edu.au> - March 2000 45 * 46 * The file handle is seens as a list of 4byte words. 47 * The first word contains a version number (1) and four descriptor bytes 48 * that tell how the remaining 3 variable length fields should be handled. 49 * These three bytes are auth_type, fsid_type and fileid_type. 50 * 51 * All 4byte values are in host-byte-order. 52 * 53 * The auth_type field specifies how the filehandle can be authenticated 54 * This might allow a file to be confirmed to be in a writable part of a 55 * filetree without checking the path from it upto the root. 56 * Current values: 57 * 0 - No authentication. fb_auth is 0 bytes long 58 * Possible future values: 59 * 1 - 4 bytes taken from MD5 hash of the remainer of the file handle 60 * prefixed by a secret and with the important export flags. 61 * 62 * The fsid_type identifies how the filesystem (or export point) is 63 * encoded. 64 * Current values: 65 * 0 - 4 byte device id (ms-2-bytes major, ls-2-bytes minor), 4byte inode number 66 * NOTE: we cannot use the kdev_t device id value, because kdev_t.h 67 * says we mustn't. We must break it up and reassemble. 68 * 1 - 4 byte user specified identifier 69 * 2 - 4 byte major, 4 byte minor, 4 byte inode number - DEPRECATED 70 * 3 - 4 byte device id, encoded for user-space, 4 byte inode number 71 * 72 * The fileid_type identified how the file within the filesystem is encoded. 73 * This is (will be) passed to, and set by, the underlying filesystem if it supports 74 * filehandle operations. The filesystem must not use the value '0' or '0xff' and may 75 * only use the values 1 and 2 as defined below: 76 * Current values: 77 * 0 - The root, or export point, of the filesystem. fb_fileid is 0 bytes. 78 * 1 - 32bit inode number, 32 bit generation number. 79 * 2 - 32bit inode number, 32 bit generation number, 32 bit parent directory inode number. 80 * 81 */ 82 struct nfs_fhbase_new { 83 __u8 fb_version; /* == 1, even => nfs_fhbase_old */ 84 __u8 fb_auth_type; 85 __u8 fb_fsid_type; 86 __u8 fb_fileid_type; 87 __u32 fb_auth[1]; 88 /* __u32 fb_fsid[0]; floating */ 89 /* __u32 fb_fileid[0]; floating */ 90 }; 91 92 struct knfsd_fh { 93 unsigned int fh_size; /* significant for NFSv3. 94 * Points to the current size while building 95 * a new file handle 96 */ 97 union { 98 struct nfs_fhbase_old fh_old; 99 __u32 fh_pad[NFS4_FHSIZE/4]; 100 struct nfs_fhbase_new fh_new; 101 } fh_base; 102 }; 103 104 #define ofh_dcookie fh_base.fh_old.fb_dcookie 105 #define ofh_ino fh_base.fh_old.fb_ino 106 #define ofh_dirino fh_base.fh_old.fb_dirino 107 #define ofh_dev fh_base.fh_old.fb_dev 108 #define ofh_xdev fh_base.fh_old.fb_xdev 109 #define ofh_xino fh_base.fh_old.fb_xino 110 #define ofh_generation fh_base.fh_old.fb_generation 111 112 #define fh_version fh_base.fh_new.fb_version 113 #define fh_fsid_type fh_base.fh_new.fb_fsid_type 114 #define fh_auth_type fh_base.fh_new.fb_auth_type 115 #define fh_fileid_type fh_base.fh_new.fb_fileid_type 116 #define fh_auth fh_base.fh_new.fb_auth 117 #define fh_fsid fh_base.fh_new.fb_auth 118 119 #ifdef __KERNEL__ 120 121 static inline __u32 ino_t_to_u32(ino_t ino) 122 { 123 return (__u32) ino; 124 } 125 126 static inline ino_t u32_to_ino_t(__u32 uino) 127 { 128 return (ino_t) uino; 129 } 130 131 /* 132 * This is the internal representation of an NFS handle used in knfsd. 133 * pre_mtime/post_version will be used to support wcc_attr's in NFSv3. 134 */ 135 typedef struct svc_fh { 136 struct knfsd_fh fh_handle; /* FH data */ 137 struct dentry * fh_dentry; /* validated dentry */ 138 struct svc_export * fh_export; /* export pointer */ 139 int fh_maxsize; /* max size for fh_handle */ 140 141 unsigned char fh_locked; /* inode locked by us */ 142 143 #ifdef CONFIG_NFSD_V3 144 unsigned char fh_post_saved; /* post-op attrs saved */ 145 unsigned char fh_pre_saved; /* pre-op attrs saved */ 146 147 /* Pre-op attributes saved during fh_lock */ 148 __u64 fh_pre_size; /* size before operation */ 149 struct timespec fh_pre_mtime; /* mtime before oper */ 150 struct timespec fh_pre_ctime; /* ctime before oper */ 151 152 /* Post-op attributes saved in fh_unlock */ 153 umode_t fh_post_mode; /* i_mode */ 154 nlink_t fh_post_nlink; /* i_nlink */ 155 uid_t fh_post_uid; /* i_uid */ 156 gid_t fh_post_gid; /* i_gid */ 157 __u64 fh_post_size; /* i_size */ 158 unsigned long fh_post_blocks; /* i_blocks */ 159 unsigned long fh_post_blksize;/* i_blksize */ 160 __u32 fh_post_rdev[2];/* i_rdev */ 161 struct timespec fh_post_atime; /* i_atime */ 162 struct timespec fh_post_mtime; /* i_mtime */ 163 struct timespec fh_post_ctime; /* i_ctime */ 164 #endif /* CONFIG_NFSD_V3 */ 165 166 } svc_fh; 167 168 static inline void mk_fsid_v0(u32 *fsidv, dev_t dev, ino_t ino) 169 { 170 fsidv[0] = htonl((MAJOR(dev)<<16) | 171 MINOR(dev)); 172 fsidv[1] = ino_t_to_u32(ino); 173 } 174 175 static inline void mk_fsid_v1(u32 *fsidv, u32 fsid) 176 { 177 fsidv[0] = fsid; 178 } 179 180 static inline void mk_fsid_v2(u32 *fsidv, dev_t dev, ino_t ino) 181 { 182 fsidv[0] = htonl(MAJOR(dev)); 183 fsidv[1] = htonl(MINOR(dev)); 184 fsidv[2] = ino_t_to_u32(ino); 185 } 186 187 static inline void mk_fsid_v3(u32 *fsidv, dev_t dev, ino_t ino) 188 { 189 fsidv[0] = new_encode_dev(dev); 190 fsidv[1] = ino_t_to_u32(ino); 191 } 192 193 static inline int key_len(int type) 194 { 195 switch(type) { 196 case 0: return 8; 197 case 1: return 4; 198 case 2: return 12; 199 case 3: return 8; 200 default: return 0; 201 } 202 } 203 204 /* 205 * Shorthand for dprintk()'s 206 */ 207 extern char * SVCFH_fmt(struct svc_fh *fhp); 208 209 /* 210 * Function prototypes 211 */ 212 u32 fh_verify(struct svc_rqst *, struct svc_fh *, int, int); 213 int fh_compose(struct svc_fh *, struct svc_export *, struct dentry *, struct svc_fh *); 214 int fh_update(struct svc_fh *); 215 void fh_put(struct svc_fh *); 216 217 static __inline__ struct svc_fh * 218 fh_copy(struct svc_fh *dst, struct svc_fh *src) 219 { 220 if (src->fh_dentry || src->fh_locked) { 221 struct dentry *dentry = src->fh_dentry; 222 printk(KERN_ERR "fh_copy: copying %s/%s, already verified!\n", 223 dentry->d_parent->d_name.name, dentry->d_name.name); 224 } 225 226 *dst = *src; 227 return dst; 228 } 229 230 static __inline__ struct svc_fh * 231 fh_init(struct svc_fh *fhp, int maxsize) 232 { 233 memset(fhp, 0, sizeof(*fhp)); 234 fhp->fh_maxsize = maxsize; 235 return fhp; 236 } 237 238 #ifdef CONFIG_NFSD_V3 239 /* 240 * Fill in the pre_op attr for the wcc data 241 */ 242 static inline void 243 fill_pre_wcc(struct svc_fh *fhp) 244 { 245 struct inode *inode; 246 247 inode = fhp->fh_dentry->d_inode; 248 if (!fhp->fh_pre_saved) { 249 fhp->fh_pre_mtime = inode->i_mtime; 250 fhp->fh_pre_ctime = inode->i_ctime; 251 fhp->fh_pre_size = inode->i_size; 252 fhp->fh_pre_saved = 1; 253 } 254 } 255 256 /* 257 * Fill in the post_op attr for the wcc data 258 */ 259 static inline void 260 fill_post_wcc(struct svc_fh *fhp) 261 { 262 struct inode *inode = fhp->fh_dentry->d_inode; 263 264 if (fhp->fh_post_saved) 265 printk("nfsd: inode locked twice during operation.\n"); 266 267 fhp->fh_post_mode = inode->i_mode; 268 fhp->fh_post_nlink = inode->i_nlink; 269 fhp->fh_post_uid = inode->i_uid; 270 fhp->fh_post_gid = inode->i_gid; 271 fhp->fh_post_size = inode->i_size; 272 if (inode->i_blksize) { 273 fhp->fh_post_blksize = inode->i_blksize; 274 fhp->fh_post_blocks = inode->i_blocks; 275 } else { 276 fhp->fh_post_blksize = BLOCK_SIZE; 277 /* how much do we care for accuracy with MinixFS? */ 278 fhp->fh_post_blocks = (inode->i_size+511) >> 9; 279 } 280 fhp->fh_post_rdev[0] = htonl((u32)imajor(inode)); 281 fhp->fh_post_rdev[1] = htonl((u32)iminor(inode)); 282 fhp->fh_post_atime = inode->i_atime; 283 fhp->fh_post_mtime = inode->i_mtime; 284 fhp->fh_post_ctime = inode->i_ctime; 285 fhp->fh_post_saved = 1; 286 } 287 #else 288 #define fill_pre_wcc(ignored) 289 #define fill_post_wcc(notused) 290 #endif /* CONFIG_NFSD_V3 */ 291 292 293 /* 294 * Lock a file handle/inode 295 * NOTE: both fh_lock and fh_unlock are done "by hand" in 296 * vfs.c:nfsd_rename as it needs to grab 2 i_mutex's at once 297 * so, any changes here should be reflected there. 298 */ 299 static inline void 300 fh_lock(struct svc_fh *fhp) 301 { 302 struct dentry *dentry = fhp->fh_dentry; 303 struct inode *inode; 304 305 dfprintk(FILEOP, "nfsd: fh_lock(%s) locked = %d\n", 306 SVCFH_fmt(fhp), fhp->fh_locked); 307 308 if (!fhp->fh_dentry) { 309 printk(KERN_ERR "fh_lock: fh not verified!\n"); 310 return; 311 } 312 if (fhp->fh_locked) { 313 printk(KERN_WARNING "fh_lock: %s/%s already locked!\n", 314 dentry->d_parent->d_name.name, dentry->d_name.name); 315 return; 316 } 317 318 inode = dentry->d_inode; 319 mutex_lock(&inode->i_mutex); 320 fill_pre_wcc(fhp); 321 fhp->fh_locked = 1; 322 } 323 324 /* 325 * Unlock a file handle/inode 326 */ 327 static inline void 328 fh_unlock(struct svc_fh *fhp) 329 { 330 if (!fhp->fh_dentry) 331 printk(KERN_ERR "fh_unlock: fh not verified!\n"); 332 333 if (fhp->fh_locked) { 334 fill_post_wcc(fhp); 335 mutex_unlock(&fhp->fh_dentry->d_inode->i_mutex); 336 fhp->fh_locked = 0; 337 } 338 } 339 #endif /* __KERNEL__ */ 340 341 342 #endif /* _LINUX_NFSD_FH_H */ 343
