1 files changed, 532 insertions, 0 deletions

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
new file mode 100644
index 000000000000..7a3e397b4ed3
--- /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;
+}