sunrpc: add a new "stringify_acceptor" rpc_credop

...and add an new rpc_auth function to call it when it exists. This
is only applicable for AUTH_GSS mechanisms, so we only specify this
for those sorts of credentials.

Signed-off-by: Jeff Layton <jlayton@poochiereds.net>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

2 files changed, 51 insertions, 20 deletions

diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c
index f77366717420..1481efff6aa2 100644
--- a/net/sunrpc/auth.c
+++ b/net/sunrpc/auth.c
@@ -363,6 +363,15 @@ rpcauth_cred_key_to_expire(struct rpc_cred *cred)
 }
 EXPORT_SYMBOL_GPL(rpcauth_cred_key_to_expire);
 
+char *
+rpcauth_stringify_acceptor(struct rpc_cred *cred)
+{
+        if (!cred->cr_ops->crstringify_acceptor)
+                return NULL;
+        return cred->cr_ops->crstringify_acceptor(cred);
+}
+EXPORT_SYMBOL_GPL(rpcauth_stringify_acceptor);
+
 /*
  * Destroy a list of credentials
  */
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index e34af68603bd..73854314fb85 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -1346,6 +1346,26 @@ gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
         return err;
 }
 
+static char *
+gss_stringify_acceptor(struct rpc_cred *cred)
+{
+        char *string;
+        struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
+        struct xdr_netobj *acceptor = &gss_cred->gc_ctx->gc_acceptor;
+
+        /* no point if there's no string */
+        if (!acceptor->len)
+                return NULL;
+
+        string = kmalloc(acceptor->len + 1, GFP_KERNEL);
+        if (!string)
+                return string;
+
+        memcpy(string, acceptor->data, acceptor->len);
+        string[acceptor->len] = '\0';
+        return string;
+}
+
 /*
  * Returns -EACCES if GSS context is NULL or will expire within the
  * timeout (miliseconds)
@@ -1923,29 +1943,31 @@ static const struct rpc_authops authgss_ops = {
 };
 
 static const struct rpc_credops gss_credops = {
-        .cr_name        = "AUTH_GSS",
-        .crdestroy      = gss_destroy_cred,
-        .cr_init        = gss_cred_init,
-        .crbind         = rpcauth_generic_bind_cred,
-        .crmatch        = gss_match,
-        .crmarshal      = gss_marshal,
-        .crrefresh      = gss_refresh,
-        .crvalidate     = gss_validate,
-        .crwrap_req     = gss_wrap_req,
-        .crunwrap_resp  = gss_unwrap_resp,
-        .crkey_timeout  = gss_key_timeout,
+        .cr_name                = "AUTH_GSS",
+        .crdestroy              = gss_destroy_cred,
+        .cr_init                = gss_cred_init,
+        .crbind                 = rpcauth_generic_bind_cred,
+        .crmatch                = gss_match,
+        .crmarshal              = gss_marshal,
+        .crrefresh              = gss_refresh,
+        .crvalidate             = gss_validate,
+        .crwrap_req             = gss_wrap_req,
+        .crunwrap_resp          = gss_unwrap_resp,
+        .crkey_timeout          = gss_key_timeout,
+        .crstringify_acceptor   = gss_stringify_acceptor,
 };
 
 static const struct rpc_credops gss_nullops = {
-        .cr_name        = "AUTH_GSS",
-        .crdestroy      = gss_destroy_nullcred,
-        .crbind         = rpcauth_generic_bind_cred,
-        .crmatch        = gss_match,
-        .crmarshal      = gss_marshal,
-        .crrefresh      = gss_refresh_null,
-        .crvalidate     = gss_validate,
-        .crwrap_req     = gss_wrap_req,
-        .crunwrap_resp  = gss_unwrap_resp,
+        .cr_name                = "AUTH_GSS",
+        .crdestroy              = gss_destroy_nullcred,
+        .crbind                 = rpcauth_generic_bind_cred,
+        .crmatch                = gss_match,
+        .crmarshal              = gss_marshal,
+        .crrefresh              = gss_refresh_null,
+        .crvalidate             = gss_validate,
+        .crwrap_req             = gss_wrap_req,
+        .crunwrap_resp          = gss_unwrap_resp,
+        .crstringify_acceptor   = gss_stringify_acceptor,
 };
 
 static const struct rpc_pipe_ops gss_upcall_ops_v0 = {