s4-winbind Add a proxy method to update DNS records with a read-write DC

This must be done in winbindd as it already has the schannel connection
and the credential chain.  If we re-established that elsewhere, we
would break the chain in winbindd.

Andrew Bartlett

Signed-Off-By: Andrew Tridgell <tridge@samba.org>

4 files changed, 219 insertions, 1 deletions

diff --git a/source4/winbind/wb_irpc.c b/source4/winbind/wb_irpc.c
index bfb31e66a7..1eed89fd41 100644
--- a/source4/winbind/wb_irpc.c
+++ b/source4/winbind/wb_irpc.c
@@ -71,6 +71,52 @@ static void wb_irpc_SamLogon_callback(struct composite_context *ctx)
 	irpc_send_reply(s->msg, status);
 }
 
+struct wb_irpc_DsrUpdateReadOnlyServerDnsRecords_state {
+	struct irpc_message *msg;
+	struct winbind_DsrUpdateReadOnlyServerDnsRecords *req;
+};
+
+static void wb_irpc_DsrUpdateReadOnlyServerDnsRecords_callback(struct composite_context *ctx);
+
+static NTSTATUS wb_irpc_DsrUpdateReadOnlyServerDnsRecords(struct irpc_message *msg,
+				 struct winbind_DsrUpdateReadOnlyServerDnsRecords *req)
+{
+	struct wbsrv_service *service = talloc_get_type(msg->private_data,
+					struct wbsrv_service);
+	struct wb_irpc_DsrUpdateReadOnlyServerDnsRecords_state *s;
+	struct composite_context *ctx;
+
+	DEBUG(5, ("wb_irpc_DsrUpdateReadOnlyServerDnsRecords called\n"));
+
+	s = talloc(msg, struct wb_irpc_DsrUpdateReadOnlyServerDnsRecords_state);
+	NT_STATUS_HAVE_NO_MEMORY(s);
+
+	s->msg = msg;
+	s->req = req;
+
+	ctx = wb_update_rodc_dns_send(msg, service, req);
+	NT_STATUS_HAVE_NO_MEMORY(ctx);
+
+	ctx->async.fn = wb_irpc_DsrUpdateReadOnlyServerDnsRecords_callback;
+	ctx->async.private_data = s;
+
+	msg->defer_reply = true;
+	return NT_STATUS_OK;
+}
+
+static void wb_irpc_DsrUpdateReadOnlyServerDnsRecords_callback(struct composite_context *ctx)
+{
+	struct wb_irpc_DsrUpdateReadOnlyServerDnsRecords_state *s = talloc_get_type(ctx->async.private_data,
+					   struct wb_irpc_DsrUpdateReadOnlyServerDnsRecords_state);
+	NTSTATUS status;
+
+	DEBUG(5, ("wb_irpc_DsrUpdateReadOnlyServerDnsRecords_callback called\n"));
+
+	status = wb_update_rodc_dns_recv(ctx, s, s->req);
+
+	irpc_send_reply(s->msg, status);
+}
+
 struct wb_irpc_get_idmap_state {
 	struct irpc_message *msg;
 	struct winbind_get_idmap *req;
@@ -149,6 +195,10 @@ NTSTATUS wbsrv_init_irpc(struct wbsrv_service *service)
 			       wb_irpc_SamLogon, service);
 	NT_STATUS_NOT_OK_RETURN(status);
 
+	status = IRPC_REGISTER(service->task->msg_ctx, winbind, WINBIND_DSRUPDATEREADONLYSERVERDNSRECORDS,
+			       wb_irpc_DsrUpdateReadOnlyServerDnsRecords, service);
+	NT_STATUS_NOT_OK_RETURN(status);
+
 	status = IRPC_REGISTER(service->task->msg_ctx, winbind, WINBIND_GET_IDMAP,
 			       wb_irpc_get_idmap, service);
 	NT_STATUS_NOT_OK_RETURN(status);
diff --git a/source4/winbind/wb_server.h b/source4/winbind/wb_server.h
index ddb77d05f6..f20bc0aa51 100644
--- a/source4/winbind/wb_server.h
+++ b/source4/winbind/wb_server.h
@@ -176,6 +176,7 @@ struct wbsrv_samba3_call {
 struct netr_LMSessionKey;
 struct netr_UserSessionKey;
 struct winbind_SamLogon;
+struct winbind_DsrUpdateReadOnlyServerDnsRecords;
 
 #include "winbind/wb_async_helpers.h"
 #include "winbind/wb_proto.h"
diff --git a/source4/winbind/wb_update_rodc_dns.c b/source4/winbind/wb_update_rodc_dns.c
new file mode 100644
index 0000000000..5ad2d0cbb0
--- /dev/null
+++ b/source4/winbind/wb_update_rodc_dns.c
@@ -0,0 +1,167 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Do a netr_DsrUpdateReadOnlyServerDnsRecords to a remote DC
+
+   Copyright (C) Andrew Bartlett 2010
+   Copyright (C) Andrew Tridgell 2010
+
+   based heavily on wb_sam_logon.c which is copyright:
+
+   Copyright (C) Volker Lendecke 2005
+   Copyright (C) Andrew Bartlett 2005
+   Copyright (C) Stefan Metzmacher 2006
+
+   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 "libcli/composite/composite.h"
+#include "winbind/wb_server.h"
+#include "smbd/service_task.h"
+#include "auth/credentials/credentials.h"
+#include "libcli/auth/libcli_auth.h"
+#include "librpc/gen_ndr/ndr_netlogon_c.h"
+#include "librpc/gen_ndr/winbind.h"
+
+struct wb_update_rodc_dns_state {
+	struct composite_context *ctx;
+
+	struct winbind_DsrUpdateReadOnlyServerDnsRecords *req;
+
+        struct netlogon_creds_CredentialState *creds_state;
+        struct netr_Authenticator auth1, auth2;
+
+	TALLOC_CTX *r_mem_ctx;
+        struct netr_DsrUpdateReadOnlyServerDnsRecords r;
+};
+
+static void wb_update_rodc_dns_recv_domain(struct composite_context *ctx);
+static void wb_update_rodc_dns_recv_response(struct tevent_req *subreq);
+
+/*
+    Find the connection to the DC (or find an existing connection)
+*/
+struct composite_context *wb_update_rodc_dns_send(TALLOC_CTX *mem_ctx,
+					    struct wbsrv_service *service,
+					    struct winbind_DsrUpdateReadOnlyServerDnsRecords *req)
+{
+	struct composite_context *c, *creq;
+	struct wb_update_rodc_dns_state *s;
+
+	c = composite_create(mem_ctx, service->task->event_ctx);
+	if (!c) return NULL;
+
+	s = talloc_zero(c, struct wb_update_rodc_dns_state);
+	if (composite_nomem(s, c)) return c;
+	s->ctx = c;
+	s->req = req;
+
+	c->private_data = s;
+
+	creq = wb_sid2domain_send(s, service, service->primary_sid);
+	composite_continue(c, creq, wb_update_rodc_dns_recv_domain, s);
+	return c;
+}
+
+/*
+    Having finished making the connection to the DC
+    Send of a DsrUpdateReadOnlyServerDnsRecords request to authenticate a user.
+*/
+static void wb_update_rodc_dns_recv_domain(struct composite_context *creq)
+{
+	struct wb_update_rodc_dns_state *s = talloc_get_type(creq->async.private_data,
+				       struct wb_update_rodc_dns_state);
+	struct wbsrv_domain *domain;
+	struct tevent_req *subreq;
+
+	s->ctx->status = wb_sid2domain_recv(creq, &domain);
+	if (!composite_is_ok(s->ctx)) return;
+
+	s->creds_state = cli_credentials_get_netlogon_creds(domain->libnet_ctx->cred);
+	netlogon_creds_client_authenticator(s->creds_state, &s->auth1);
+
+	s->r.in.server_name = talloc_asprintf(s, "\\\\%s",
+			      dcerpc_server_name(domain->netlogon_pipe));
+	if (composite_nomem(s->r.in.server_name, s->ctx)) return;
+
+	s->r.in.computer_name = cli_credentials_get_workstation(domain->libnet_ctx->cred);
+	s->r.in.credential = &s->auth1;
+	s->r.out.return_authenticator = &s->auth2;
+	s->r.in.site_name = s->req->in.site_name;
+	s->r.in.dns_ttl = s->req->in.dns_ttl;
+	s->r.in.dns_names = s->req->in.dns_names;
+	s->r.out.dns_names = s->req->in.dns_names;
+
+	/*
+	 * use a new talloc context for the DsrUpdateReadOnlyServerDnsRecords call
+	 * because then we can just to a talloc_steal on this context
+	 * in the final _recv() function to give the caller all the content of
+	 * the s->r.out.dns_names
+	 */
+	s->r_mem_ctx = talloc_new(s);
+	if (composite_nomem(s->r_mem_ctx, s->ctx)) return;
+
+	subreq = dcerpc_netr_DsrUpdateReadOnlyServerDnsRecords_r_send(s,
+						  s->ctx->event_ctx,
+						  domain->netlogon_pipe->binding_handle,
+						  &s->r);
+	if (composite_nomem(subreq, s->ctx)) return;
+	tevent_req_set_callback(subreq, wb_update_rodc_dns_recv_response, s);
+}
+
+/*
+   NTLM Authentication
+
+   Check the DsrUpdateReadOnlyServerDnsRecords reply and decrypt the session keys
+*/
+static void wb_update_rodc_dns_recv_response(struct tevent_req *subreq)
+{
+	struct wb_update_rodc_dns_state *s = tevent_req_callback_data(subreq,
+				       struct wb_update_rodc_dns_state);
+
+	s->ctx->status = dcerpc_netr_DsrUpdateReadOnlyServerDnsRecords_r_recv(subreq, s->r_mem_ctx);
+	TALLOC_FREE(subreq);
+	if (!composite_is_ok(s->ctx)) return;
+
+	s->ctx->status = s->r.out.result;
+	if (!composite_is_ok(s->ctx)) return;
+
+	if ((s->r.out.return_authenticator == NULL) ||
+	    (!netlogon_creds_client_check(s->creds_state,
+					  &s->r.out.return_authenticator->cred))) {
+		DEBUG(0, ("Credentials check failed!\n"));
+		composite_error(s->ctx, NT_STATUS_ACCESS_DENIED);
+		return;
+	}
+
+	composite_done(s->ctx);
+}
+
+NTSTATUS wb_update_rodc_dns_recv(struct composite_context *c,
+			   TALLOC_CTX *mem_ctx,
+			   struct winbind_DsrUpdateReadOnlyServerDnsRecords *req)
+{
+	struct wb_update_rodc_dns_state *s = talloc_get_type(c->private_data,
+				       struct wb_update_rodc_dns_state);
+	NTSTATUS status = composite_wait(c);
+
+	if (NT_STATUS_IS_OK(status)) {
+		talloc_steal(mem_ctx, s->r_mem_ctx);
+		req->out.dns_names	= s->r.out.dns_names;
+	}
+
+	talloc_free(s);
+	return status;
+}
diff --git a/source4/winbind/wscript_build b/source4/winbind/wscript_build
index c9682f3eec..2c8a6f8317 100644
--- a/source4/winbind/wscript_build
+++ b/source4/winbind/wscript_build
@@ -2,7 +2,7 @@
 
 
 bld.SAMBA_MODULE('WINBIND',
-	source='wb_server.c wb_irpc.c wb_samba3_protocol.c wb_samba3_cmd.c wb_init_domain.c wb_dom_info.c wb_dom_info_trusted.c wb_sid2domain.c wb_name2domain.c wb_sids2xids.c wb_xids2sids.c wb_gid2sid.c wb_sid2uid.c wb_sid2gid.c wb_uid2sid.c wb_connect_lsa.c wb_connect_sam.c wb_cmd_lookupname.c wb_cmd_lookupsid.c wb_cmd_getdcname.c wb_cmd_getgrnam.c wb_cmd_getgrgid.c wb_cmd_getpwnam.c wb_cmd_getpwuid.c wb_cmd_userdomgroups.c wb_cmd_usersids.c wb_cmd_list_groups.c wb_cmd_list_trustdom.c wb_cmd_list_users.c wb_cmd_setpwent.c wb_cmd_getpwent.c wb_cmd_getgrent.c wb_cmd_setgrent.c wb_cmd_getgroups.c wb_pam_auth.c wb_sam_logon.c',
+	source='wb_server.c wb_irpc.c wb_samba3_protocol.c wb_samba3_cmd.c wb_init_domain.c wb_dom_info.c wb_dom_info_trusted.c wb_sid2domain.c wb_name2domain.c wb_sids2xids.c wb_xids2sids.c wb_gid2sid.c wb_sid2uid.c wb_sid2gid.c wb_uid2sid.c wb_connect_lsa.c wb_connect_sam.c wb_cmd_lookupname.c wb_cmd_lookupsid.c wb_cmd_getdcname.c wb_cmd_getgrnam.c wb_cmd_getgrgid.c wb_cmd_getpwnam.c wb_cmd_getpwuid.c wb_cmd_userdomgroups.c wb_cmd_usersids.c wb_cmd_list_groups.c wb_cmd_list_trustdom.c wb_cmd_list_users.c wb_cmd_setpwent.c wb_cmd_getpwent.c wb_cmd_getgrent.c wb_cmd_setgrent.c wb_cmd_getgroups.c wb_pam_auth.c wb_sam_logon.c wb_update_rodc_dns.c',
 	autoproto='wb_proto.h',
 	subsystem='service',
 	init_function='server_service_winbind_init',