SUNRPC: Refactor nfsd4_do_encode_secinfo()

Clean up.  This matches a similar API for the client side, and
keeps ULP fingers out the of the GSS mech switch.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

6 files changed, 87 insertions, 15 deletions

diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c
index 01168865dd37..2a2745615b42 100644
--- a/fs/nfsd/nfs4xdr.c
+++ b/fs/nfsd/nfs4xdr.c
@@ -3138,10 +3138,9 @@ nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_
 
 static __be32
 nfsd4_do_encode_secinfo(struct nfsd4_compoundres *resp,
-                         __be32 nfserr,struct svc_export *exp)
+                         __be32 nfserr, struct svc_export *exp)
 {
-        int i = 0;
-        u32 nflavs;
+        u32 i, nflavs;
         struct exp_flavor_info *flavs;
         struct exp_flavor_info def_flavs[2];
         __be32 *p;
@@ -3172,30 +3171,29 @@ nfsd4_do_encode_secinfo(struct nfsd4_compoundres *resp,
         WRITE32(nflavs);
         ADJUST_ARGS();
         for (i = 0; i < nflavs; i++) {
-                u32 flav = flavs[i].pseudoflavor;
-                struct gss_api_mech *gm = gss_mech_get_by_pseudoflavor(flav);
+                struct rpcsec_gss_info info;
 
-                if (gm) {
+                if (rpcauth_get_gssinfo(flavs[i].pseudoflavor, &info) == 0) {
                         RESERVE_SPACE(4);
                         WRITE32(RPC_AUTH_GSS);
                         ADJUST_ARGS();
-                        RESERVE_SPACE(4 + gm->gm_oid.len);
-                        WRITE32(gm->gm_oid.len);
-                        WRITEMEM(gm->gm_oid.data, gm->gm_oid.len);
+                        RESERVE_SPACE(4 + info.oid.len);
+                        WRITE32(info.oid.len);
+                        WRITEMEM(info.oid.data, info.oid.len);
                         ADJUST_ARGS();
                         RESERVE_SPACE(4);
-                        WRITE32(0); /* qop */
+                        WRITE32(info.qop);
                         ADJUST_ARGS();
                         RESERVE_SPACE(4);
-                        WRITE32(gss_pseudoflavor_to_service(gm, flav));
+                        WRITE32(info.service);
                         ADJUST_ARGS();
-                        gss_mech_put(gm);
                 } else {
                         RESERVE_SPACE(4);
-                        WRITE32(flav);
+                        WRITE32(flavs[i].pseudoflavor);
                         ADJUST_ARGS();
                 }
         }
+
 out:
         if (exp)
                 exp_put(exp);
diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index 6851da4cb416..0dd00f4f6810 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -106,6 +106,8 @@ struct rpc_authops {
         void                    (*pipes_destroy)(struct rpc_auth *);
         int                     (*list_pseudoflavors)(rpc_authflavor_t *, int);
         rpc_authflavor_t        (*info2flavor)(struct rpcsec_gss_info *);
+        int                     (*flavor2info)(rpc_authflavor_t,
+                                                struct rpcsec_gss_info *);
 };
 
 struct rpc_credops {
@@ -142,6 +144,8 @@ struct rpc_auth *	rpcauth_create(rpc_authflavor_t, struct rpc_clnt *);
 void                    rpcauth_release(struct rpc_auth *);
 rpc_authflavor_t        rpcauth_get_pseudoflavor(rpc_authflavor_t,
                                 struct rpcsec_gss_info *);
+int                     rpcauth_get_gssinfo(rpc_authflavor_t,
+                                struct rpcsec_gss_info *);
 int                     rpcauth_list_flavors(rpc_authflavor_t *, int);
 struct rpc_cred *       rpcauth_lookup_credcache(struct rpc_auth *, struct auth_cred *, int);
 void                    rpcauth_init_cred(struct rpc_cred *, const struct auth_cred *, struct rpc_auth *, const struct rpc_credops *);
diff --git a/include/linux/sunrpc/gss_api.h b/include/linux/sunrpc/gss_api.h
index 96e5a81a54d7..fca23380e667 100644
--- a/include/linux/sunrpc/gss_api.h
+++ b/include/linux/sunrpc/gss_api.h
@@ -133,6 +133,9 @@ void gss_mech_unregister(struct gss_api_mech *);
 /* Given a GSS security tuple, look up a pseudoflavor */
 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *);
 
+/* Given a pseudoflavor, look up a GSS security tuple */
+int gss_mech_flavor2info(rpc_authflavor_t, struct rpcsec_gss_info *);
+
 /* Returns a reference to a mechanism, given a name like "krb5" etc. */
 struct gss_api_mech *gss_mech_get_by_name(const char *);
 
diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index 9b81be8d9946..2bc0cc2196e0 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -159,6 +159,41 @@ rpcauth_get_pseudoflavor(rpc_authflavor_t flavor, struct rpcsec_gss_info *info)
 EXPORT_SYMBOL_GPL(rpcauth_get_pseudoflavor);
 
 /**
+ * rpcauth_get_gssinfo - find GSS tuple matching a GSS pseudoflavor
+ * @pseudoflavor: GSS pseudoflavor to match
+ * @info: rpcsec_gss_info structure to fill in
+ *
+ * Returns zero and fills in "info" if pseudoflavor matches a
+ * supported mechanism.
+ */
+int
+rpcauth_get_gssinfo(rpc_authflavor_t pseudoflavor, struct rpcsec_gss_info *info)
+{
+        rpc_authflavor_t flavor = pseudoflavor_to_flavor(pseudoflavor);
+        const struct rpc_authops *ops;
+        int result;
+
+        ops = auth_flavors[flavor];
+        if (ops == NULL)
+                request_module("rpc-auth-%u", flavor);
+        spin_lock(&rpc_authflavor_lock);
+        ops = auth_flavors[flavor];
+        if (ops == NULL || !try_module_get(ops->owner)) {
+                spin_unlock(&rpc_authflavor_lock);
+                return -ENOENT;
+        }
+        spin_unlock(&rpc_authflavor_lock);
+
+        result = -ENOENT;
+        if (ops->flavor2info != NULL)
+                result = ops->flavor2info(pseudoflavor, info);
+
+        module_put(ops->owner);
+        return result;
+}
+EXPORT_SYMBOL_GPL(rpcauth_get_gssinfo);
+
+/**
  * rpcauth_list_flavors - discover registered flavors and pseudoflavors
  * @array: array to fill in
  * @size: size of "array"
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index a7420076ef39..51415b07174e 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1642,6 +1642,7 @@ static const struct rpc_authops authgss_ops = {
         .pipes_destroy  = gss_pipes_dentries_destroy,
         .list_pseudoflavors = gss_mech_list_pseudoflavors,
         .info2flavor    = gss_mech_info2flavor,
+        .flavor2info    = gss_mech_flavor2info,
 };
 
 static const struct rpc_credops gss_credops = {
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c
index 81fb6f3e2424..deaa7ae81cdf 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -240,8 +240,6 @@ gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
         return gm;
 }
 
-EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
-
 /**
  * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
  * @array: array to fill in
@@ -315,6 +313,39 @@ rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
         return pseudoflavor;
 }
 
+/**
+ * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
+ * @pseudoflavor: GSS pseudoflavor to match
+ * @info: rpcsec_gss_info structure to fill in
+ *
+ * Returns zero and fills in "info" if pseudoflavor matches a
+ * supported mechanism.  Otherwise a negative errno is returned.
+ */
+int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
+                         struct rpcsec_gss_info *info)
+{
+        struct gss_api_mech *gm;
+        int i;
+
+        gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
+        if (gm == NULL)
+                return -ENOENT;
+
+        for (i = 0; i < gm->gm_pf_num; i++) {
+                if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
+                        memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
+                        info->oid.len = gm->gm_oid.len;
+                        info->qop = gm->gm_pfs[i].qop;
+                        info->service = gm->gm_pfs[i].service;
+                        gss_mech_put(gm);
+                        return 0;
+                }
+        }
+
+        gss_mech_put(gm);
+        return -ENOENT;
+}
+
 u32
 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
 {