+__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp)
+{
+ struct exp_flavor_info *f;
+ struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
+
+ /* legacy gss-only clients are always OK: */
+ if (exp->ex_client == rqstp->rq_gssclient)
+ return 0;
+ /* ip-address based client; check sec= export option: */
+ for (f = exp->ex_flavors; f < end; f++) {
+ if (f->pseudoflavor == rqstp->rq_flavor)
+ return 0;
+ }
+ /* defaults in absence of sec= options: */
+ if (exp->ex_nflavors == 0) {
+ if (rqstp->rq_flavor == RPC_AUTH_NULL ||
+ rqstp->rq_flavor == RPC_AUTH_UNIX)
+ return 0;
+ }
+ return nfserr_wrongsec;
+}
+
+/*
+ * Uses rq_client and rq_gssclient to find an export; uses rq_client (an
+ * auth_unix client) if it's available and has secinfo information;
+ * otherwise, will try to use rq_gssclient.
+ *
+ * Called from functions that handle requests; functions that do work on
+ * behalf of mountd are passed a single client name to use, and should
+ * use exp_get_by_name() or exp_find().
+ */
+struct svc_export *
+rqst_exp_get_by_name(struct svc_rqst *rqstp, struct vfsmount *mnt,
+ struct dentry *dentry)
+{
+ struct svc_export *gssexp, *exp = NULL;
+
+ if (rqstp->rq_client == NULL)
+ goto gss;
+
+ /* First try the auth_unix client: */
+ exp = exp_get_by_name(rqstp->rq_client, mnt, dentry,
+ &rqstp->rq_chandle);
+ if (PTR_ERR(exp) == -ENOENT)
+ goto gss;
+ if (IS_ERR(exp))
+ return exp;
+ /* If it has secinfo, assume there are no gss/... clients */
+ if (exp->ex_nflavors > 0)
+ return exp;
+gss:
+ /* Otherwise, try falling back on gss client */
+ if (rqstp->rq_gssclient == NULL)
+ return exp;
+ gssexp = exp_get_by_name(rqstp->rq_gssclient, mnt, dentry,
+ &rqstp->rq_chandle);
+ if (PTR_ERR(gssexp) == -ENOENT)
+ return exp;
+ if (exp && !IS_ERR(exp))
+ exp_put(exp);
+ return gssexp;
+}
+
+struct svc_export *
+rqst_exp_find(struct svc_rqst *rqstp, int fsid_type, u32 *fsidv)
+{
+ struct svc_export *gssexp, *exp = NULL;
+
+ if (rqstp->rq_client == NULL)
+ goto gss;
+
+ /* First try the auth_unix client: */
+ exp = exp_find(rqstp->rq_client, fsid_type, fsidv, &rqstp->rq_chandle);
+ if (PTR_ERR(exp) == -ENOENT)
+ goto gss;
+ if (IS_ERR(exp))
+ return exp;
+ /* If it has secinfo, assume there are no gss/... clients */
+ if (exp->ex_nflavors > 0)
+ return exp;
+gss:
+ /* Otherwise, try falling back on gss client */
+ if (rqstp->rq_gssclient == NULL)
+ return exp;
+ gssexp = exp_find(rqstp->rq_gssclient, fsid_type, fsidv,
+ &rqstp->rq_chandle);
+ if (PTR_ERR(gssexp) == -ENOENT)
+ return exp;
+ if (exp && !IS_ERR(exp))
+ exp_put(exp);
+ return gssexp;
+}
+
+struct svc_export *
+rqst_exp_parent(struct svc_rqst *rqstp, struct vfsmount *mnt,
+ struct dentry *dentry)
+{
+ struct svc_export *exp;
+
+ dget(dentry);
+ exp = rqst_exp_get_by_name(rqstp, mnt, dentry);
+
+ while (PTR_ERR(exp) == -ENOENT && !IS_ROOT(dentry)) {
+ struct dentry *parent;
+
+ parent = dget_parent(dentry);
+ dput(dentry);
+ dentry = parent;
+ exp = rqst_exp_get_by_name(rqstp, mnt, dentry);
+ }
+ dput(dentry);
+ return exp;
+}