#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/svcauth_gss.h>
#include <linux/nfsd/nfsd.h>
+#include "vfs.h"
#include "auth.h"
#define NFSDDBG_FACILITY NFSDDBG_FH
-static int nfsd_nr_verified;
-static int nfsd_nr_put;
-
/*
* our acceptability function.
* if NOSUBTREECHECK, accept anything
goto out;
}
- if (exp->ex_flags & NFSEXP_NOSUBTREECHECK) {
- error = nfsd_setuser_and_check_port(rqstp, exp);
- if (error) {
- dput(dentry);
- goto out;
- }
- }
-
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",
fhp->fh_dentry = dentry;
fhp->fh_export = exp;
- nfsd_nr_verified++;
return 0;
out:
exp_put(exp);
return error;
}
-/*
- * Perform sanity checks on the dentry in a client's file handle.
+/**
+ * fh_verify - filehandle lookup and access checking
+ * @rqstp: pointer to current rpc request
+ * @fhp: filehandle to be verified
+ * @type: expected type of object pointed to by filehandle
+ * @access: type of access needed to object
+ *
+ * Look up a dentry from the on-the-wire filehandle, check the client's
+ * access to the export, and set the current task's credentials.
+ *
+ * Regardless of success or failure of fh_verify(), fh_put() should be
+ * called on @fhp when the caller is finished with the filehandle.
*
- * Note that the file handle dentry may need to be freed even after
- * an error return.
+ * fh_verify() may be called multiple times on a given filehandle, for
+ * example, when processing an NFSv4 compound. The first call will look
+ * up a dentry using the on-the-wire filehandle. Subsequent calls will
+ * skip the lookup and just perform the other checks and possibly change
+ * the current task's credentials.
*
- * 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.
+ * @type specifies the type of object expected using one of the S_IF*
+ * constants defined in include/linux/stat.h. The caller may use zero
+ * to indicate that it doesn't care, or a negative integer to indicate
+ * that it expects something not of the given type.
+ *
+ * @access is formed from the NFSD_MAY_* constants defined in
+ * include/linux/nfsd/nfsd.h.
*/
__be32
fh_verify(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access)
error = nfsd_set_fh_dentry(rqstp, fhp);
if (error)
goto out;
- dentry = fhp->fh_dentry;
- exp = fhp->fh_export;
- } 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;
- /*
- * Set user creds for this exportpoint; necessary even
- * in the "just checking" case because this may be a
- * filehandle that was created by fh_compose, and that
- * is about to be used in another nfsv4 compound
- * operation.
- */
- error = nfsd_setuser_and_check_port(rqstp, exp);
- if (error)
- goto out;
}
+ dentry = fhp->fh_dentry;
+ exp = fhp->fh_export;
+ /*
+ * We still have to do all these permission checks, even when
+ * fh_dentry is already set:
+ * - fh_verify may be called multiple times with different
+ * "access" arguments (e.g. nfsd_proc_create calls
+ * fh_verify(...,NFSD_MAY_EXEC) first, then later (in
+ * nfsd_create) calls fh_verify(...,NFSD_MAY_CREATE).
+ * - in the NFSv4 case, the filehandle may have been filled
+ * in by fh_compose, and given a dentry, but further
+ * compound operations performed with that filehandle
+ * still need permissions checks. In the worst case, a
+ * mountpoint crossing may have changed the export
+ * options, and we may now need to use a different uid
+ * (for example, if different id-squashing options are in
+ * effect on the new filesystem).
+ */
+ error = nfsd_setuser_and_check_port(rqstp, exp);
+ if (error)
+ goto out;
error = nfsd_mode_check(rqstp, dentry->d_inode->i_mode, type);
if (error)
fh->ofh_dirino = 0;
}
-__be32
-fh_compose(struct svc_fh *fhp, struct svc_export *exp, struct dentry *dentry,
- struct svc_fh *ref_fh)
+static bool is_root_export(struct svc_export *exp)
{
- /* ref_fh is a reference file handle.
- * if it is non-null and for the same filesystem, 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
- *
- */
+ return exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root;
+}
- u8 version;
- u8 fsid_type = 0;
- struct inode * inode = dentry->d_inode;
- struct dentry *parent = dentry->d_parent;
- __u32 *datap;
- dev_t ex_dev = exp->ex_path.dentry->d_inode->i_sb->s_dev;
- int root_export = (exp->ex_path.dentry == exp->ex_path.dentry->d_sb->s_root);
+static struct super_block *exp_sb(struct svc_export *exp)
+{
+ return exp->ex_path.dentry->d_inode->i_sb;
+}
- dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
- MAJOR(ex_dev), MINOR(ex_dev),
- (long) exp->ex_path.dentry->d_inode->i_ino,
- parent->d_name.name, dentry->d_name.name,
- (inode ? inode->i_ino : 0));
+static bool fsid_type_ok_for_exp(u8 fsid_type, struct svc_export *exp)
+{
+ switch (fsid_type) {
+ case FSID_DEV:
+ if (!old_valid_dev(exp_sb(exp)->s_dev))
+ return 0;
+ /* FALL THROUGH */
+ case FSID_MAJOR_MINOR:
+ case FSID_ENCODE_DEV:
+ return exp_sb(exp)->s_type->fs_flags & FS_REQUIRES_DEV;
+ case FSID_NUM:
+ return exp->ex_flags & NFSEXP_FSID;
+ case FSID_UUID8:
+ case FSID_UUID16:
+ if (!is_root_export(exp))
+ return 0;
+ /* fall through */
+ case FSID_UUID4_INUM:
+ case FSID_UUID16_INUM:
+ return exp->ex_uuid != NULL;
+ }
+ return 1;
+}
- /* Choose filehandle version and fsid type based on
- * the reference filehandle (if it is in the same export)
- * or the export options.
- */
- retry:
+
+static void set_version_and_fsid_type(struct svc_fh *fhp, struct svc_export *exp, struct svc_fh *ref_fh)
+{
+ u8 version;
+ u8 fsid_type;
+retry:
version = 1;
if (ref_fh && ref_fh->fh_export == exp) {
version = ref_fh->fh_handle.fh_version;
fsid_type = ref_fh->fh_handle.fh_fsid_type;
- if (ref_fh == fhp)
- fh_put(ref_fh);
ref_fh = NULL;
switch (version) {
goto retry;
}
- /* Need to check that this type works for this
- * export point. As the fsid -> filesystem mapping
- * was guided by user-space, there is no guarantee
- * that the filesystem actually supports that fsid
- * type. If it doesn't we loop around again without
- * ref_fh set.
+ /*
+ * As the fsid -> filesystem mapping was guided by
+ * user-space, there is no guarantee that the filesystem
+ * actually supports that fsid type. If it doesn't we
+ * loop around again without ref_fh set.
*/
- switch(fsid_type) {
- case FSID_DEV:
- if (!old_valid_dev(ex_dev))
- goto retry;
- /* FALL THROUGH */
- case FSID_MAJOR_MINOR:
- case FSID_ENCODE_DEV:
- if (!(exp->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
- & FS_REQUIRES_DEV))
- goto retry;
- break;
- case FSID_NUM:
- if (! (exp->ex_flags & NFSEXP_FSID))
- goto retry;
- break;
- case FSID_UUID8:
- case FSID_UUID16:
- if (!root_export)
- goto retry;
- /* fall through */
- case FSID_UUID4_INUM:
- case FSID_UUID16_INUM:
- if (exp->ex_uuid == NULL)
- goto retry;
- break;
- }
+ if (!fsid_type_ok_for_exp(fsid_type, exp))
+ goto retry;
+ } else if (exp->ex_flags & NFSEXP_FSID) {
+ fsid_type = FSID_NUM;
} else if (exp->ex_uuid) {
if (fhp->fh_maxsize >= 64) {
- if (root_export)
+ if (is_root_export(exp))
fsid_type = FSID_UUID16;
else
fsid_type = FSID_UUID16_INUM;
} else {
- if (root_export)
+ if (is_root_export(exp))
fsid_type = FSID_UUID8;
else
fsid_type = FSID_UUID4_INUM;
}
- } else if (exp->ex_flags & NFSEXP_FSID)
- fsid_type = FSID_NUM;
- else if (!old_valid_dev(ex_dev))
+ } else if (!old_valid_dev(exp_sb(exp)->s_dev))
/* for newer device numbers, we must use a newer fsid format */
fsid_type = FSID_ENCODE_DEV;
else
fsid_type = FSID_DEV;
+ fhp->fh_handle.fh_version = version;
+ if (version)
+ fhp->fh_handle.fh_fsid_type = fsid_type;
+}
+
+__be32
+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 and for the same filesystem, 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
+ *
+ */
+
+ struct inode * inode = dentry->d_inode;
+ struct dentry *parent = dentry->d_parent;
+ __u32 *datap;
+ dev_t ex_dev = exp_sb(exp)->s_dev;
+
+ dprintk("nfsd: fh_compose(exp %02x:%02x/%ld %s/%s, ino=%ld)\n",
+ MAJOR(ex_dev), MINOR(ex_dev),
+ (long) exp->ex_path.dentry->d_inode->i_ino,
+ parent->d_name.name, dentry->d_name.name,
+ (inode ? inode->i_ino : 0));
+
+ /* Choose filehandle version and fsid type based on
+ * the reference filehandle (if it is in the same export)
+ * or the export options.
+ */
+ set_version_and_fsid_type(fhp, exp, ref_fh);
if (ref_fh == fhp)
fh_put(ref_fh);
fhp->fh_export = exp;
cache_get(&exp->h);
- if (version == 0xca) {
+ if (fhp->fh_handle.fh_version == 0xca) {
/* old style filehandle please */
memset(&fhp->fh_handle.fh_base, 0, NFS_FHSIZE);
fhp->fh_handle.fh_size = NFS_FHSIZE;
_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 = fsid_type;
- mk_fsid(fsid_type, datap, ex_dev,
+ mk_fsid(fhp->fh_handle.fh_fsid_type, datap, ex_dev,
exp->ex_path.dentry->d_inode->i_ino,
exp->ex_fsid, exp->ex_uuid);
- len = key_len(fsid_type);
+ len = key_len(fhp->fh_handle.fh_fsid_type);
datap += len/4;
fhp->fh_handle.fh_size = 4 + len;
if (inode)
_fh_update(fhp, exp, dentry);
- if (fhp->fh_handle.fh_fileid_type == 255)
+ if (fhp->fh_handle.fh_fileid_type == 255) {
+ fh_put(fhp);
return nfserr_opnotsupp;
+ }
}
- nfsd_nr_verified++;
return 0;
}
fhp->fh_pre_saved = 0;
fhp->fh_post_saved = 0;
#endif
- nfsd_nr_put++;
}
if (exp) {
cache_put(&exp->h, &svc_export_cache);
case FSID_DEV:
case FSID_ENCODE_DEV:
case FSID_MAJOR_MINOR:
- if (fhp->fh_export->ex_path.dentry->d_inode->i_sb->s_type->fs_flags
- & FS_REQUIRES_DEV)
+ if (exp_sb(fhp->fh_export)->s_type->fs_flags & FS_REQUIRES_DEV)
return FSIDSOURCE_DEV;
break;
case FSID_NUM:
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