/* * linux/fs/nfsd/nfsfh.c * * NFS server file handle treatment. * * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> * Portions Copyright (C) 1999 G. Allen Morris III <gam3@acm.org> * Extensive rewrite by Neil Brown <neilb@cse.unsw.edu.au> Southern-Spring 1999 * ... and again Southern-Winter 2001 to support export_operations */ #include <linux/sched.h> #include <linux/slab.h> #include <linux/smp_lock.h> #include <linux/fs.h> #include <linux/unistd.h> #include <linux/string.h> #include <linux/stat.h> #include <linux/dcache.h> #include <linux/mount.h> #include <asm/pgtable.h> #include <linux/sunrpc/svc.h> #include <linux/nfsd/nfsd.h> #define NFSDDBG_FACILITY NFSDDBG_FH #define NFSD_PARANOIA 1 /* #define NFSD_DEBUG_VERBOSE 1 */ static int nfsd_nr_verified; static int nfsd_nr_put; extern struct export_operations export_op_default; #define CALL(ops,fun) ((ops->fun)?(ops->fun):export_op_default.fun) /* * our acceptability function. * if NOSUBTREECHECK, accept anything * if not, require that we can walk up to exp->ex_dentry * doing some checks on the 'x' bits */ static int nfsd_acceptable(void *expv, struct dentry *dentry) { struct svc_export *exp = expv; int rv; struct dentry *tdentry; struct dentry *parent; if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) return 1; tdentry = dget(dentry); while (tdentry != exp->ex_dentry && ! IS_ROOT(tdentry)) { /* make sure parents give x permission to user */ int err; parent = dget_parent(tdentry); err = permission(parent->d_inode, MAY_EXEC, NULL); if (err < 0) { dput(parent); break; } dput(tdentry); tdentry = parent; } if (tdentry != exp->ex_dentry) dprintk("nfsd_acceptable failed at %p %s\n", tdentry, tdentry->d_name.name); rv = (tdentry == exp->ex_dentry); dput(tdentry); return rv; } /* Type check. The correct error return for type mismatches does not seem to be * generally agreed upon. SunOS seems to use EISDIR if file isn't S_IFREG; a * comment in the NFSv3 spec says this is incorrect (implementation notes for * the write call). */ static inline int nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type) { /* Type can be negative when creating hardlinks - not to a dir */ if (type > 0 && (mode & S_IFMT) != type) { if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK) return nfserr_symlink; else if (type == S_IFDIR) return nfserr_notdir; else if ((mode & S_IFMT) == S_IFDIR) return nfserr_isdir; else return nfserr_inval; } if (type < 0 && (mode & S_IFMT) == -type) { if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK) return nfserr_symlink; else if (type == -S_IFDIR) return nfserr_isdir; else return nfserr_notdir; } return 0; } /* * Perform sanity checks on the dentry in a client's file handle. * * Note that the file handle dentry may need to be freed even after * an error return. * * This is only called at the start of an nfsproc call, so fhp points to * a svc_fh which is all 0 except for the over-the-wire file handle. */ u32 fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access) { struct knfsd_fh *fh = &fhp->fh_handle; struct svc_export *exp = NULL; struct dentry *dentry; u32 error = 0; dprintk("nfsd: fh_verify(%s)\n", SVCFH_fmt(fhp)); /* keep this filehandle for possible reference when encoding attributes */ rqstp->rq_reffh = fh; if (!fhp->fh_dentry) { __u32 *datap=NULL; __u32 tfh[3]; /* filehandle fragment for oldstyle filehandles */ int fileid_type; int data_left = fh->fh_size/4; error = nfserr_stale; if (rqstp->rq_client == NULL) goto out; if (rqstp->rq_vers > 2) error = nfserr_badhandle; if (rqstp->rq_vers == 4 && fh->fh_size == 0) return nfserr_nofilehandle; if (fh->fh_version == 1) { int len; datap = fh->fh_auth; if (--data_left<0) goto out; switch (fh->fh_auth_type) { case 0: break; default: goto out; } len = key_len(fh->fh_fsid_type) / 4; if (len == 0) goto out; if (fh->fh_fsid_type == 2) { /* deprecated, convert to type 3 */ len = 3; fh->fh_fsid_type = 3; fh->fh_fsid[0] = new_encode_dev(MKDEV(ntohl(fh->fh_fsid[0]), ntohl(fh->fh_fsid[1]))); fh->fh_fsid[1] = fh->fh_fsid[2]; } if ((data_left -= len)<0) goto out; exp = exp_find(rqstp->rq_client, fh->fh_fsid_type, datap, &rqstp->rq_chandle); datap += len; } else { dev_t xdev; ino_t xino; if (fh->fh_size != NFS_FHSIZE) goto out; /* assume old filehandle format */ xdev = old_decode_dev(fh->ofh_xdev); xino = u32_to_ino_t(fh->ofh_xino); mk_fsid_v0(tfh, xdev, xino); exp = exp_find(rqstp->rq_client, 0, tfh, &rqstp->rq_chandle); } error = nfserr_dropit; if (IS_ERR(exp) && PTR_ERR(exp) == -EAGAIN) goto out; error = nfserr_stale; if (!exp || IS_ERR(exp)) goto out; /* Check if the request originated from a secure port. */ error = nfserr_perm; if (!rqstp->rq_secure && EX_SECURE(exp)) { printk(KERN_WARNING "nfsd: request from insecure port (%u.%u.%u.%u:%d)!\n", NIPQUAD(rqstp->rq_addr.sin_addr.s_addr), ntohs(rqstp->rq_addr.sin_port)); goto out; } /* Set user creds for this exportpoint */ error = nfsd_setuser(rqstp, exp); if (error) { error = nfserrno(error); goto out; } /* * Look up the dentry using the NFS file handle. */ error = nfserr_stale; if (rqstp->rq_vers > 2) error = nfserr_badhandle; if (fh->fh_version != 1) { tfh[0] = fh->ofh_ino; tfh[1] = fh->ofh_generation; tfh[2] = fh->ofh_dirino; datap = tfh; data_left = 3; if (fh->ofh_dirino == 0) fileid_type = 1; else fileid_type = 2; } else fileid_type = fh->fh_fileid_type; if (fileid_type == 0) dentry = dget(exp->ex_dentry); else { struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op; dentry = CALL(nop,decode_fh)(exp->ex_mnt->mnt_sb, datap, data_left, fileid_type, nfsd_acceptable, exp); } if (dentry == NULL) goto out; if (IS_ERR(dentry)) { if (PTR_ERR(dentry) != -EINVAL) error = nfserrno(PTR_ERR(dentry)); goto out; } #ifdef NFSD_PARANOIA if (S_ISDIR(dentry->d_inode->i_mode) && (dentry->d_flags & DCACHE_DISCONNECTED)) { printk("nfsd: find_fh_dentry returned a DISCONNECTED directory: %s/%s\n", dentry->d_parent->d_name.name, dentry->d_name.name); } #endif fhp->fh_dentry = dentry; fhp->fh_export = exp; nfsd_nr_verified++; } else { /* just rechecking permissions * (e.g. nfsproc_create calls fh_verify, then nfsd_create does as well) */ dprintk("nfsd: fh_verify - just checking\n"); dentry = fhp->fh_dentry; exp = fhp->fh_export; } cache_get(&exp->h); error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type); if (error) goto out; /* Finally, check access permissions. */ error = nfsd_permission(exp, dentry, access); #ifdef NFSD_PARANOIA_EXTREME if (error) { printk("fh_verify: %s/%s permission failure, acc=%x, error=%d\n", dentry->d_parent->d_name.name, dentry->d_name.name, access, (error >> 24)); } #endif out: if (exp && !IS_ERR(exp)) exp_put(exp); if (error == nfserr_stale) nfsdstats.fh_stale++; return error; } /* * Compose a file handle for an NFS reply. * * Note that when first composed, the dentry may not yet have * an inode. In this case a call to fh_update should be made * before the fh goes out on the wire ... */ static inline int _fh_update(struct dentry *dentry, struct svc_export *exp, __u32 *datap, int *maxsize) { struct export_operations *nop = exp->ex_mnt->mnt_sb->s_export_op; if (dentry == exp->ex_dentry) { *maxsize = 0; return 0; } return CALL(nop,encode_fh)(dentry, datap, maxsize, !(exp->ex_flags&NFSEXP_NOSUBTREECHECK)); } /* * for composing old style file handles */ static inline void _fh_update_old(struct dentry *dentry, struct svc_export *exp, struct knfsd_fh *fh) { fh->ofh_ino = ino_t_to_u32(dentry->d_inode->i_ino); fh->ofh_generation = dentry->d_inode->i_generation; if (S_ISDIR(dentry->d_inode->i_mode) || (exp->ex_flags & NFSEXP_NOSUBTREECHECK)) fh->ofh_dirino = 0; } int fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry, struct svc_fh *ref_fh) { /* ref_fh is a reference file handle. * if it is non-null, then we should compose a filehandle which is * of the same version, where possible. * Currently, that means that if ref_fh->fh_handle.fh_version == 0xca * Then create a 32byte filehandle using nfs_fhbase_old * */ u8 ref_fh_version = 0; u8 ref_fh_fsid_type = 0; struct inode * inode = dentry->d_inode; struct dentry *parent = dentry->d_parent; __u32 *datap; dev_t ex_dev = exp->ex_dentry->d_inode->i_sb->s_dev; dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n", MAJOR(ex_dev), MINOR(ex_dev), (long) exp->ex_dentry->d_inode->i_ino, parent->d_name.name, dentry->d_name.name, (inode ? inode->i_ino : 0)); if (ref_fh) { ref_fh_version = ref_fh->fh_handle.fh_version; if (ref_fh_version == 0xca) ref_fh_fsid_type = 0; else ref_fh_fsid_type = ref_fh->fh_handle.fh_fsid_type; if (ref_fh_fsid_type > 3) ref_fh_fsid_type = 0; /* make sure ref_fh type works for given export */ if (ref_fh_fsid_type == 1 && !(exp->ex_flags & NFSEXP_FSID)) { /* if we don't have an fsid, we cannot provide one... */ ref_fh_fsid_type = 0; } } else if (exp->ex_flags & NFSEXP_FSID) ref_fh_fsid_type = 1; if (!old_valid_dev(ex_dev) && ref_fh_fsid_type == 0) { /* for newer device numbers, we must use a newer fsid format */ ref_fh_version = 1; ref_fh_fsid_type = 3; } if (old_valid_dev(ex_dev) && (ref_fh_fsid_type == 2 || ref_fh_fsid_type == 3)) /* must use type1 for smaller device numbers */ ref_fh_fsid_type = 0; if (ref_fh == fhp) fh_put(ref_fh); if (fhp->fh_locked || fhp->fh_dentry) { printk(KERN_ERR "fh_compose: fh %s/%s not initialized!\n", parent->d_name.name, dentry->d_name.name); } if (fhp->fh_maxsize < NFS_FHSIZE) printk(KERN_ERR "fh_compose: called with maxsize %d! %s/%s\n", fhp->fh_maxsize, parent->d_name.name, dentry->d_name.name); fhp->fh_dentry = dget(dentry); /* our internal copy */ fhp->fh_export = exp; cache_get(&exp->h); if (ref_fh_version == 0xca) { /* old style filehandle please */ memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE); fhp->fh_handle.fh_size = NFS_FHSIZE; fhp->fh_handle.ofh_dcookie = 0xfeebbaca; fhp->fh_handle.ofh_dev = old_encode_dev(ex_dev); fhp->fh_handle.ofh_xdev = fhp->fh_handle.ofh_dev; fhp->fh_handle.ofh_xino = ino_t_to_u32(exp->ex_dentry->d_inode->i_ino); fhp->fh_handle.ofh_dirino = ino_t_to_u32(parent_ino(dentry)); if (inode) _fh_update_old(dentry, exp, &fhp->fh_handle); } else { int len; fhp->fh_handle.fh_version = 1; fhp->fh_handle.fh_auth_type = 0; datap = fhp->fh_handle.fh_auth+0; fhp->fh_handle.fh_fsid_type = ref_fh_fsid_type; switch (ref_fh_fsid_type) { case 0: /* * fsid_type 0: * 2byte major, 2byte minor, 4byte inode */ mk_fsid_v0(datap, ex_dev, exp->ex_dentry->d_inode->i_ino); break; case 1: /* fsid_type 1 == 4 bytes filesystem id */ mk_fsid_v1(datap, exp->ex_fsid); break; case 2: /* * fsid_type 2: * 4byte major, 4byte minor, 4byte inode */ mk_fsid_v2(datap, ex_dev, exp->ex_dentry->d_inode->i_ino); break; case 3: /* * fsid_type 3: * 4byte devicenumber, 4byte inode */ mk_fsid_v3(datap, ex_dev, exp->ex_dentry->d_inode->i_ino); break; } len = key_len(ref_fh_fsid_type); datap += len/4; fhp->fh_handle.fh_size = 4 + len; if (inode) { int size = (fhp->fh_maxsize-len-4)/4; fhp->fh_handle.fh_fileid_type = _fh_update(dentry, exp, datap, &size); fhp->fh_handle.fh_size += size*4; } if (fhp->fh_handle.fh_fileid_type == 255) return nfserr_opnotsupp; } nfsd_nr_verified++; return 0; } /* * Update file handle information after changing a dentry. * This is only called by nfsd_create, nfsd_create_v3 and nfsd_proc_create */ int fh_update(struct svc_fh *fhp) { struct dentry *dentry; __u32 *datap; if (!fhp->fh_dentry) goto out_bad; dentry = fhp->fh_dentry; if (!dentry->d_inode) goto out_negative; if (fhp->fh_handle.fh_version != 1) { _fh_update_old(dentry, fhp->fh_export, &fhp->fh_handle); } else { int size; if (fhp->fh_handle.fh_fileid_type != 0) goto out_uptodate; datap = fhp->fh_handle.fh_auth+ fhp->fh_handle.fh_size/4 -1; size = (fhp->fh_maxsize - fhp->fh_handle.fh_size)/4; fhp->fh_handle.fh_fileid_type = _fh_update(dentry, fhp->fh_export, datap, &size); fhp->fh_handle.fh_size += size*4; if (fhp->fh_handle.fh_fileid_type == 255) return nfserr_opnotsupp; } out: return 0; out_bad: printk(KERN_ERR "fh_update: fh not verified!\n"); goto out; out_negative: printk(KERN_ERR "fh_update: %s/%s still negative!\n", dentry->d_parent->d_name.name, dentry->d_name.name); goto out; out_uptodate: printk(KERN_ERR "fh_update: %s/%s already up-to-date!\n", dentry->d_parent->d_name.name, dentry->d_name.name); goto out; } /* * Release a file handle. */ void fh_put(struct svc_fh *fhp) { struct dentry * dentry = fhp->fh_dentry; struct svc_export * exp = fhp->fh_export; if (dentry) { fh_unlock(fhp); fhp->fh_dentry = NULL; dput(dentry); #ifdef CONFIG_NFSD_V3 fhp->fh_pre_saved = 0; fhp->fh_post_saved = 0; #endif nfsd_nr_put++; } if (exp) { cache_put(&exp->h, &svc_export_cache); fhp->fh_export = NULL; } return; } /* * Shorthand for dprintk()'s */ char * SVCFH_fmt(struct svc_fh *fhp) { struct knfsd_fh *fh = &fhp->fh_handle; static char buf[80]; sprintf(buf, "%d: %08x %08x %08x %08x %08x %08x", fh->fh_size, fh->fh_base.fh_pad[0], fh->fh_base.fh_pad[1], fh->fh_base.fh_pad[2], fh->fh_base.fh_pad[3], fh->fh_base.fh_pad[4], fh->fh_base.fh_pad[5]); return buf; }