1 files changed, 532 insertions, 0 deletions

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
new file mode 100644
index 0000000..7a3e397
--- /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;
+}