s4-finddcs: added finddcs_cldap()

this finds DCs with a specified set of server_type bit using SRV
lookups and CLDAP

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

3 files changed, 284 insertions, 3 deletions

diff --git a/source4/libcli/finddcs.h b/source4/libcli/finddcs.h
new file mode 100644
index 0000000000..9e6e2dfe83
--- /dev/null
+++ b/source4/libcli/finddcs.h
@@ -0,0 +1,37 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   a composite API for finding a DC and its name
+
+   Copyright (C) Andrew Tridgell 2010
+
+   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 "libcli/netlogon.h"
+
+struct finddcs {
+	struct {
+		const char *dns_domain_name;
+		const char *site_name; /* optional */
+		struct dom_sid *domain_sid; /* optional */
+		uint32_t minimum_dc_flags; /* DS_SERVER_* */
+	} in;
+	struct {
+		const char *address; /* IP address of server */
+		struct netlogon_samlogon_response netlogon;
+	} out;
+};
+
+#include "finddcs_proto.h"
diff --git a/source4/libcli/finddcs_cldap.c b/source4/libcli/finddcs_cldap.c
new file mode 100644
index 0000000000..6842a0958a
--- /dev/null
+++ b/source4/libcli/finddcs_cldap.c
@@ -0,0 +1,244 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   a composite API for finding a DC and its name via CLDAP
+
+   Copyright (C) Andrew Tridgell 2010
+   Copyright (C) Andrew Bartlett 2010
+
+   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 "include/includes.h"
+#include <tevent.h>
+#include "libcli/resolve/resolve.h"
+#include "lib/messaging/messaging.h"
+#include "libcli/libcli.h"
+#include "libcli/cldap/cldap.h"
+#include "libcli/finddcs.h"
+#include "libcli/security/dom_sid.h"
+#include "lib/util/tevent_ntstatus.h"
+#include "libcli/composite/composite.h"
+
+struct finddcs_cldap_state {
+	struct tevent_context *ev;
+	struct tevent_req *req;
+	const char *dns_domain_name;
+	struct dom_sid *domain_sid;
+	const char **srv_addresses;
+	uint32_t minimum_dc_flags;
+	uint32_t srv_address_index;
+	struct cldap_socket *cldap;
+	struct cldap_netlogon *netlogon;
+};
+
+static void finddcs_cldap_srv_resolved(struct composite_context *ctx);
+static void finddcs_cldap_netlogon_replied(struct tevent_req *req);
+
+
+/*
+ * find a list of DCs via DNS/CLDAP
+ *
+ */
+struct tevent_req *finddcs_cldap_send(TALLOC_CTX *mem_ctx,
+				      struct finddcs *io,
+				      struct resolve_context *resolve_ctx,
+				      struct tevent_context *event_ctx)
+{
+	struct finddcs_cldap_state *state;
+	struct tevent_req *req;
+	const char *srv_name;
+	struct composite_context *creq;
+	struct nbt_name name;
+
+	req = tevent_req_create(mem_ctx, &state, struct finddcs_cldap_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	state->req = req;
+	state->ev = event_ctx;
+	state->minimum_dc_flags = io->in.minimum_dc_flags;
+	state->dns_domain_name = talloc_strdup(state, io->in.dns_domain_name);
+	if (tevent_req_nomem(state->dns_domain_name, req)) {
+		return tevent_req_post(req, event_ctx);
+	}
+
+	if (io->in.domain_sid) {
+		state->domain_sid = dom_sid_dup(state, io->in.domain_sid);
+		if (tevent_req_nomem(state->domain_sid, req)) {
+			return tevent_req_post(req, event_ctx);
+		}
+	} else {
+		state->domain_sid = NULL;
+	}
+
+	/* step1: lookup _ldap._tcp.* */
+	if (io->in.site_name) {
+		srv_name = talloc_asprintf(state, "_ldap._tcp.%s._sites.%s",
+					   io->in.site_name, io->in.dns_domain_name);
+	} else {
+		srv_name = talloc_asprintf(state, "_ldap._tcp.%s", io->in.dns_domain_name);
+	}
+
+	make_nbt_name(&name, srv_name, 0);
+
+	creq = resolve_name_ex_send(resolve_ctx, state,
+				    RESOLVE_NAME_FLAG_FORCE_DNS | RESOLVE_NAME_FLAG_DNS_SRV,
+				    0, &name, event_ctx);
+	if (tevent_req_nomem(creq, req)) {
+		return tevent_req_post(req, event_ctx);
+	}
+	creq->async.fn = finddcs_cldap_srv_resolved;
+	creq->async.private_data = state;
+
+	return req;
+}
+
+
+/*
+  fire off a CLDAP query to the next server
+ */
+static void finddcs_cldap_next_server(struct finddcs_cldap_state *state)
+{
+	struct tevent_req *subreq;
+
+	if (state->srv_addresses[state->srv_address_index] == NULL) {
+		tevent_req_nterror(state->req, NT_STATUS_OBJECT_NAME_NOT_FOUND);
+		return;
+	}
+
+	state->netlogon = talloc_zero(state, struct cldap_netlogon);
+	if (tevent_req_nomem(state->netlogon, state->req)) {
+		return;
+	}
+
+	state->netlogon->in.dest_address = state->srv_addresses[state->srv_address_index];
+	/* we should get the port from the SRV response */
+	state->netlogon->in.dest_port = 389;
+	state->netlogon->in.realm = state->dns_domain_name;
+	if (state->domain_sid) {
+		state->netlogon->in.domain_sid = dom_sid_string(state, state->domain_sid);
+		if (tevent_req_nomem(state->netlogon->in.domain_sid, state->req)) {
+			return;
+		}
+	}
+	state->netlogon->in.acct_control = -1;
+	state->netlogon->in.version =
+		NETLOGON_NT_VERSION_5 |
+		NETLOGON_NT_VERSION_5EX |
+		NETLOGON_NT_VERSION_IP;
+	state->netlogon->in.map_response = true;
+
+	subreq = cldap_netlogon_send(state, state->cldap, state->netlogon);
+	if (tevent_req_nomem(subreq, state->req)) {
+		return;
+	}
+
+	tevent_req_set_callback(subreq, finddcs_cldap_netlogon_replied, state);
+}
+
+
+/*
+  we have a response from a CLDAP server for a netlogon request
+ */
+static void finddcs_cldap_netlogon_replied(struct tevent_req *subreq)
+{
+	struct finddcs_cldap_state *state;
+	NTSTATUS status;
+
+	state = tevent_req_callback_data(subreq, struct finddcs_cldap_state);
+
+	status = cldap_netlogon_recv(subreq, state->netlogon, state->netlogon);
+	if (!NT_STATUS_IS_OK(status)) {
+		state->srv_address_index++;
+		finddcs_cldap_next_server(state);
+		return;
+	}
+	if (state->minimum_dc_flags !=
+	    (state->minimum_dc_flags & state->netlogon->out.netlogon.data.nt5_ex.server_type)) {
+		/* the server didn't match the minimum requirements */
+		DEBUG(4,(__location__ ": Skipping DC %s with server_type=0x%08x\n",
+			 state->srv_addresses[state->srv_address_index],
+			 state->netlogon->out.netlogon.data.nt5_ex.server_type));
+		state->srv_address_index++;
+		finddcs_cldap_next_server(state);
+		return;
+	}
+
+	talloc_free(subreq);
+	tevent_req_done(state->req);
+}
+
+
+/*
+ * Having got a DNS SRV answer, fire off the first CLDAP request
+ */
+static void finddcs_cldap_srv_resolved(struct composite_context *ctx)
+{
+	struct finddcs_cldap_state *state =
+		talloc_get_type(ctx->async.private_data, struct finddcs_cldap_state);
+	NTSTATUS status;
+
+	status = resolve_name_multiple_recv(ctx, state, &state->srv_addresses);
+	if (tevent_req_nterror(state->req, status)) {
+		return;
+	}
+
+	state->srv_address_index = 0;
+
+	status = cldap_socket_init(state, state->ev, NULL, NULL, &state->cldap);
+	if (tevent_req_nterror(state->req, status)) {
+		return;
+	}
+
+	finddcs_cldap_next_server(state);
+}
+
+
+NTSTATUS finddcs_cldap_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, struct finddcs *io)
+{
+	struct finddcs_cldap_state *state = tevent_req_data(req, struct finddcs_cldap_state);
+	bool ok;
+	NTSTATUS status;
+
+	ok = tevent_req_poll(req, state->ev);
+	if (!ok) {
+		talloc_free(req);
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+	status = tevent_req_simple_recv_ntstatus(req);
+	if (NT_STATUS_IS_OK(status)) {
+		talloc_steal(mem_ctx, state->netlogon);
+		io->out.netlogon = state->netlogon->out.netlogon;
+		io->out.address = talloc_steal(mem_ctx, state->srv_addresses[state->srv_address_index]);
+	}
+	tevent_req_received(req);
+	return status;
+}
+
+NTSTATUS finddcs_cldap(TALLOC_CTX *mem_ctx,
+		       struct finddcs *io,
+		       struct resolve_context *resolve_ctx,
+		       struct tevent_context *event_ctx)
+{
+	NTSTATUS status;
+	struct tevent_req *req = finddcs_cldap_send(mem_ctx,
+						    io,
+						    resolve_ctx,
+						    event_ctx);
+	status = finddcs_cldap_recv(req, mem_ctx, io);
+	talloc_free(req);
+	return status;
+}
diff --git a/source4/libcli/wscript_build b/source4/libcli/wscript_build
index 8a2111dab8..33623109e5 100644
--- a/source4/libcli/wscript_build
+++ b/source4/libcli/wscript_build
@@ -69,9 +69,9 @@ bld.SAMBA_SUBSYSTEM('LP_RESOLVE',
 
 
 bld.SAMBA_SUBSYSTEM('LIBCLI_FINDDCS',
-	source='finddcs.c',
-	autoproto='finddcs.h',
-	public_deps='LIBCLI_NBT MESSAGING RPC_NDR_IRPC'
+	source='finddcs.c finddcs_cldap.c',
+	autoproto='finddcs_proto.h',
+	public_deps='LIBCLI_NBT MESSAGING RPC_NDR_IRPC LIBCLI_CLDAP'
 	)