s3:winbind: Add a lower-cost alternative to wbinfo -t: wbinfo --ping-dc

This just does a NULL RPC call through an existing NETLOGON connection. If
someone knows an operation that "just works" and does not return NOT_SUPPORTED,
please tell me :-)

4 files changed, 153 insertions, 0 deletions

diff --git a/source3/winbindd/winbindd.c b/source3/winbindd/winbindd.c
index e09374c5cb..597957d9d6 100644
--- a/source3/winbindd/winbindd.c
+++ b/source3/winbindd/winbindd.c
@@ -532,6 +532,8 @@ static struct winbindd_async_dispatch_table async_nonpriv_table[] = {
 	  winbindd_list_groups_send, winbindd_list_groups_recv },
 	{ WINBINDD_CHECK_MACHACC, "CHECK_MACHACC",
 	  winbindd_check_machine_acct_send, winbindd_check_machine_acct_recv },
+	{ WINBINDD_PING_DC, "PING_DC",
+	  winbindd_ping_dc_send, winbindd_ping_dc_recv },
 
 	{ 0, NULL, NULL, NULL }
 };
diff --git a/source3/winbindd/winbindd_dual_srv.c b/source3/winbindd/winbindd_dual_srv.c
index cecbb61051..b247d5a233 100644
--- a/source3/winbindd/winbindd_dual_srv.c
+++ b/source3/winbindd/winbindd_dual_srv.c
@@ -510,6 +510,54 @@ again:
 	return status;
 }
 
+NTSTATUS _wbint_PingDc(pipes_struct *p, struct wbint_PingDc *r)
+{
+	NTSTATUS status;
+	struct winbindd_domain *domain;
+	struct rpc_pipe_client *netlogon_pipe;
+	union netr_CONTROL_QUERY_INFORMATION info;
+	WERROR werr;
+	fstring logon_server;
+
+	domain = wb_child_domain();
+	if (domain == NULL) {
+		return NT_STATUS_REQUEST_NOT_ACCEPTED;
+	}
+
+	status = cm_connect_netlogon(domain, &netlogon_pipe);
+        if (!NT_STATUS_IS_OK(status)) {
+                DEBUG(3, ("could not open handle to NETLOGON pipe\n"));
+		return status;
+        }
+
+	fstr_sprintf(logon_server, "\\\\%s", domain->dcname);
+
+	/*
+	 * This provokes a WERR_NOT_SUPPORTED error message. This is
+	 * documented in the wspp docs. I could not get a successful
+	 * call to work, but the main point here is testing that the
+	 * netlogon pipe works.
+	 */
+	status = rpccli_netr_LogonControl(netlogon_pipe, p->mem_ctx,
+					  logon_server, NETLOGON_CONTROL_QUERY,
+					  2, &info, &werr);
+
+	if (NT_STATUS_EQUAL(status, NT_STATUS_IO_TIMEOUT)) {
+		DEBUG(2, ("rpccli_netr_LogonControl timed out\n"));
+		invalidate_cm_connection(&domain->conn);
+		return status;
+	}
+
+	if (!NT_STATUS_EQUAL(status, NT_STATUS_CTL_FILE_NOT_SUPPORTED)) {
+		DEBUG(2, ("rpccli_netr_LogonControl returned %s, expected "
+			  "NT_STATUS_CTL_FILE_NOT_SUPPORTED\n",
+			  nt_errstr(status)));
+		return status;
+	}
+
+	DEBUG(5, ("winbindd_dual_ping_dc succeeded\n"));
+	return NT_STATUS_OK;
+}
 
 NTSTATUS _wbint_SetMapping(pipes_struct *p, struct wbint_SetMapping *r)
 {
diff --git a/source3/winbindd/winbindd_ping_dc.c b/source3/winbindd/winbindd_ping_dc.c
new file mode 100644
index 0000000000..e06e5896c2
--- /dev/null
+++ b/source3/winbindd/winbindd_ping_dc.c
@@ -0,0 +1,96 @@
+/*
+   Unix SMB/CIFS implementation.
+   async implementation of WINBINDD_PING_DC
+   Copyright (C) Volker Lendecke 2009
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "winbindd.h"
+#include "librpc/gen_ndr/cli_wbint.h"
+
+struct winbindd_ping_dc_state {
+	uint8_t dummy;
+};
+
+static void winbindd_ping_dc_done(struct tevent_req *subreq);
+
+struct tevent_req *winbindd_ping_dc_send(TALLOC_CTX *mem_ctx,
+					 struct tevent_context *ev,
+					 struct winbindd_cli_state *cli,
+					 struct winbindd_request *request)
+{
+	struct tevent_req *req, *subreq;
+	struct winbindd_ping_dc_state *state;
+	struct winbindd_domain *domain;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct winbindd_ping_dc_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	if (request->domain_name[0] == '\0') {
+		/* preserve old behavior, when no domain name is given */
+		domain = find_our_domain();
+	} else {
+		domain = find_domain_from_name(request->domain_name);
+	}
+	if (domain == NULL) {
+		tevent_req_nterror(req, NT_STATUS_NO_SUCH_DOMAIN);
+		return tevent_req_post(req, ev);
+	}
+	if (domain->internal) {
+		/*
+		 * Internal domains are passdb based, we can always
+		 * contact them.
+		 */
+		tevent_req_done(req);
+		return tevent_req_post(req, ev);
+	}
+
+	subreq = rpccli_wbint_PingDc_send(state, ev, domain->child.rpccli);
+	if (tevent_req_nomem(subreq, req)) {
+		return tevent_req_post(req, ev);
+	}
+	tevent_req_set_callback(subreq, winbindd_ping_dc_done, req);
+	return req;
+}
+
+static void winbindd_ping_dc_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(
+		subreq, struct tevent_req);
+	struct winbindd_ping_dc_state *state = tevent_req_data(
+		req, struct winbindd_ping_dc_state);
+	NTSTATUS status, result;
+
+	status = rpccli_wbint_PingDc_recv(subreq, state, &result);
+	if (!NT_STATUS_IS_OK(status)) {
+		tevent_req_nterror(req, status);
+		return;
+	}
+	if (!NT_STATUS_IS_OK(result)) {
+		tevent_req_nterror(req, result);
+		return;
+	}
+	tevent_req_done(req);
+}
+
+NTSTATUS winbindd_ping_dc_recv(struct tevent_req *req,
+			       struct winbindd_response *presp)
+{
+	return tevent_req_simple_recv_ntstatus(req);
+}
diff --git a/source3/winbindd/winbindd_proto.h b/source3/winbindd/winbindd_proto.h
index 5a03f5d3b8..fab31ba60b 100644
--- a/source3/winbindd/winbindd_proto.h
+++ b/source3/winbindd/winbindd_proto.h
@@ -848,6 +848,13 @@ struct tevent_req *winbindd_check_machine_acct_send(TALLOC_CTX *mem_ctx,
 NTSTATUS winbindd_check_machine_acct_recv(struct tevent_req *req,
 					  struct winbindd_response *presp);
 
+struct tevent_req *winbindd_ping_dc_send(TALLOC_CTX *mem_ctx,
+					 struct tevent_context *ev,
+					 struct winbindd_cli_state *cli,
+					 struct winbindd_request *request);
+NTSTATUS winbindd_ping_dc_recv(struct tevent_req *req,
+			       struct winbindd_response *presp);
+
 struct tevent_req *winbindd_change_machine_acct_send(TALLOC_CTX *mem_ctx,
 						     struct tevent_context *ev,
 						     struct winbindd_cli_state *cli,