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Diffstat (limited to 'fs/nfsd/nfsfh.c')
-rw-r--r--fs/nfsd/nfsfh.c532
1 files changed, 532 insertions, 0 deletions
diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
new file mode 100644
index 00000000000..7a3e397b4ed
--- /dev/null
+++ b/fs/nfsd/nfsfh.c
@@ -0,0 +1,532 @@
+/*
+ * 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) {
+ svc_export_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;
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 16:30:08 +0000