s4-kcc: add a very simple KCC

A KCC is a 'Knowledge Consistency Checker', a fancy name for a daemon
that works out who will replicate with who in a AD domain. This
implements an extremely simple KCC task that just wants to replicate
with everyone :-)

4 files changed, 533 insertions, 0 deletions

diff --git a/source4/dsdb/config.mk b/source4/dsdb/config.mk
index 2a9f70fdb5..eb26f5b433 100644
--- a/source4/dsdb/config.mk
+++ b/source4/dsdb/config.mk
@@ -65,3 +65,21 @@ DREPL_SRV_OBJ_FILES = $(addprefix $(dsdbsrcdir)/repl/, \
 		drepl_out_helpers.o)
 
 $(eval $(call proto_header_template,$(dsdbsrcdir)/repl/drepl_service_proto.h,$(DREPL_SRV_OBJ_FILES:.o=.c)))
+
+#######################
+# Start SUBSYSTEM KCC_SRV
+[MODULE::KCC_SRV]
+INIT_FUNCTION = server_service_kcc_init
+SUBSYSTEM = service
+PRIVATE_DEPENDENCIES = \
+		SAMDB \
+		process_model \
+		RPC_NDR_DRSUAPI
+# End SUBSYSTEM KCC_SRV
+#######################
+
+KCC_SRV_OBJ_FILES = $(addprefix $(dsdbsrcdir)/kcc/, \
+		kcc_service.o \
+		kcc_periodic.o)
+
+$(eval $(call proto_header_template,$(dsdbsrcdir)/kcc/kcc_service_proto.h,$(KCC_SRV_OBJ_FILES:.o=.c)))
diff --git a/source4/dsdb/kcc/kcc_periodic.c b/source4/dsdb/kcc/kcc_periodic.c
new file mode 100644
index 0000000000..649efd51ca
--- /dev/null
+++ b/source4/dsdb/kcc/kcc_periodic.c
@@ -0,0 +1,209 @@
+/* 
+   Unix SMB/CIFS mplementation.
+   KCC service periodic handling
+   
+   Copyright (C) Andrew Tridgell 2009
+   based on repl service code
+    
+   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 "lib/events/events.h"
+#include "dsdb/samdb/samdb.h"
+#include "auth/auth.h"
+#include "smbd/service.h"
+#include "lib/messaging/irpc.h"
+#include "dsdb/kcc/kcc_service.h"
+#include "lib/ldb/include/ldb_errors.h"
+#include "../lib/util/dlinklist.h"
+#include "librpc/gen_ndr/ndr_misc.h"
+#include "librpc/gen_ndr/ndr_drsuapi.h"
+#include "librpc/gen_ndr/ndr_drsblobs.h"
+#include "param/param.h"
+
+/*
+ * add a repsFrom to all our partitions
+ */
+
+
+/*
+  this is the core of our initial simple KCC
+  We just add a repsFrom entry for all DCs we find that have nTDSDSA
+  objects, except for ourselves
+ */
+static NTSTATUS kccsrv_simple_update(struct kccsrv_service *s, TALLOC_CTX *mem_ctx)
+{
+	struct ldb_result *res;
+	int ret, i;
+	const char *attrs[] = { "objectGUID", "invocationID", NULL };
+	struct ldb_message *msg;
+	struct ldb_message_element *el;
+	struct kccsrv_partition *p;
+
+	ret = ldb_search(s->samdb, mem_ctx, &res, s->config_dn, LDB_SCOPE_SUBTREE, 
+			 attrs, "objectClass=nTDSDSA");
+	if (ret != LDB_SUCCESS) {
+		DEBUG(0,(__location__ ": Failed nTDSDSA search - %s\n", ldb_errstring(s->samdb)));
+		return NT_STATUS_INTERNAL_DB_CORRUPTION;
+	}
+
+	msg = ldb_msg_new(mem_ctx);
+	NT_STATUS_HAVE_NO_MEMORY(msg);
+
+	ret = ldb_msg_add_empty(msg, "repsFrom", LDB_FLAG_MOD_REPLACE, &el);
+	if (ret != LDB_SUCCESS) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	for (i=0; i<res->count; i++) {
+		struct repsFromToBlob r;
+		struct repsFromTo1 *r1;
+		struct repsFromTo1OtherInfo oi;
+		struct GUID ntds_guid, invocation_id;
+		struct ldb_val v;
+		enum ndr_err_code ndr_err;
+
+		ntds_guid = samdb_result_guid(res->msgs[i], "objectGUID");
+		if (GUID_compare(&ntds_guid, &s->ntds_guid) == 0) {
+			/* don't replicate with ourselves */
+			continue;
+		}
+
+		invocation_id = samdb_result_guid(res->msgs[i], "invocationID");
+
+		ZERO_STRUCT(r);
+		ZERO_STRUCT(oi);
+		r.version = 1;
+		r1 = &r.ctr.ctr1;
+
+		oi.dns_name                  = talloc_asprintf(mem_ctx, "%s._msdcs.%s",
+							       GUID_string(mem_ctx, &ntds_guid),
+							       lp_realm(s->task->lp_ctx));
+		r1->other_info               = &oi;
+		r1->source_dsa_obj_guid      = ntds_guid;
+		r1->source_dsa_invocation_id = invocation_id;
+		r1->replica_flags            = 
+			DRSUAPI_DS_REPLICA_NEIGHBOUR_WRITEABLE | 
+			DRSUAPI_DS_REPLICA_NEIGHBOUR_SYNC_ON_STARTUP | 
+			DRSUAPI_DS_REPLICA_NEIGHBOUR_DO_SCHEDULED_SYNCS;
+		memset(r1->schedule, 0x11, sizeof(r1->schedule));
+
+
+		ndr_err = ndr_push_struct_blob(&v, mem_ctx, 
+					       lp_iconv_convenience(s->task->lp_ctx),
+					       &r,
+					       (ndr_push_flags_fn_t)ndr_push_repsFromToBlob);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			DEBUG(0,(__location__ ": Failed tp push repsFrom blob\n"));
+			return NT_STATUS_INTERNAL_ERROR;
+		}
+
+		el->values = talloc_realloc(msg, el->values, struct ldb_val, el->num_values+1);
+		NT_STATUS_HAVE_NO_MEMORY(el->values);
+		el->values[el->num_values] = v;
+		el->num_values++;
+	}
+
+	/* replace the repsFrom on all partitions */
+	for (p=s->partitions; p; p=p->next) {
+		msg->dn = p->dn;
+		ret = ldb_modify(s->samdb, msg);
+		if (ret != LDB_SUCCESS) {
+			DEBUG(0,(__location__ ": Failed to store repsFrom for %s - %s\n",
+				 ldb_dn_get_linearized(msg->dn), ldb_errstring(s->samdb)));
+			return NT_STATUS_INTERNAL_ERROR;
+		}
+	}
+
+	return NT_STATUS_OK;
+}
+
+
+static void kccsrv_periodic_run(struct kccsrv_service *service);
+
+static void kccsrv_periodic_handler_te(struct tevent_context *ev, struct tevent_timer *te,
+					 struct timeval t, void *ptr)
+{
+	struct kccsrv_service *service = talloc_get_type(ptr, struct kccsrv_service);
+	WERROR status;
+
+	service->periodic.te = NULL;
+
+	kccsrv_periodic_run(service);
+
+	status = kccsrv_periodic_schedule(service, service->periodic.interval);
+	if (!W_ERROR_IS_OK(status)) {
+		task_server_terminate(service->task, win_errstr(status));
+		return;
+	}
+}
+
+WERROR kccsrv_periodic_schedule(struct kccsrv_service *service, uint32_t next_interval)
+{
+	TALLOC_CTX *tmp_mem;
+	struct tevent_timer *new_te;
+	struct timeval next_time;
+
+	/* prevent looping */
+	if (next_interval == 0) next_interval = 1;
+
+	next_time = timeval_current_ofs(next_interval, 50);
+
+	if (service->periodic.te) {
+		/*
+		 * if the timestamp of the new event is higher,
+		 * as current next we don't need to reschedule
+		 */
+		if (timeval_compare(&next_time, &service->periodic.next_event) > 0) {
+			return WERR_OK;
+		}
+	}
+
+	/* reset the next scheduled timestamp */
+	service->periodic.next_event = next_time;
+
+	new_te = event_add_timed(service->task->event_ctx, service,
+			         service->periodic.next_event,
+			         kccsrv_periodic_handler_te, service);
+	W_ERROR_HAVE_NO_MEMORY(new_te);
+
+	tmp_mem = talloc_new(service);
+	DEBUG(2,("kccsrv_periodic_schedule(%u) %sscheduled for: %s\n",
+		next_interval,
+		(service->periodic.te?"re":""),
+		nt_time_string(tmp_mem, timeval_to_nttime(&next_time))));
+	talloc_free(tmp_mem);
+
+	talloc_free(service->periodic.te);
+	service->periodic.te = new_te;
+
+	return WERR_OK;
+}
+
+static void kccsrv_periodic_run(struct kccsrv_service *service)
+{
+	TALLOC_CTX *mem_ctx;
+	NTSTATUS status;
+
+	DEBUG(2,("kccsrv_periodic_run(): simple update\n"));
+
+	mem_ctx = talloc_new(service);
+	status = kccsrv_simple_update(service, mem_ctx);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0,("kccsrv_simple_update failed - %s\n", nt_errstr(status)));
+	}
+	talloc_free(mem_ctx);
+}
diff --git a/source4/dsdb/kcc/kcc_service.c b/source4/dsdb/kcc/kcc_service.c
new file mode 100644
index 0000000000..2279879000
--- /dev/null
+++ b/source4/dsdb/kcc/kcc_service.c
@@ -0,0 +1,221 @@
+/* 
+   Unix SMB/CIFS mplementation.
+
+   KCC service
+   
+   Copyright (C) Andrew Tridgell 2009
+   based on repl service code
+    
+   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 "dsdb/samdb/samdb.h"
+#include "auth/auth.h"
+#include "smbd/service.h"
+#include "lib/events/events.h"
+#include "lib/messaging/irpc.h"
+#include "dsdb/kcc/kcc_service.h"
+#include "lib/ldb/include/ldb_errors.h"
+#include "../lib/util/dlinklist.h"
+#include "librpc/gen_ndr/ndr_misc.h"
+#include "librpc/gen_ndr/ndr_drsuapi.h"
+#include "librpc/gen_ndr/ndr_drsblobs.h"
+#include "param/param.h"
+
+/*
+  establish system creds
+ */
+static WERROR kccsrv_init_creds(struct kccsrv_service *service)
+{
+	NTSTATUS status;
+
+	status = auth_system_session_info(service, service->task->lp_ctx, 
+					  &service->system_session_info);
+	if (!NT_STATUS_IS_OK(status)) {
+		return ntstatus_to_werror(status);
+	}
+
+	return WERR_OK;
+}
+
+/*
+  connect to the local SAM
+ */
+static WERROR kccsrv_connect_samdb(struct kccsrv_service *service, struct loadparm_context *lp_ctx)
+{
+	const struct GUID *ntds_guid;
+
+	service->samdb = samdb_connect(service, service->task->event_ctx, lp_ctx, service->system_session_info);
+	if (!service->samdb) {
+		return WERR_DS_UNAVAILABLE;
+	}
+
+	ntds_guid = samdb_ntds_objectGUID(service->samdb);
+	if (!ntds_guid) {
+		return WERR_DS_UNAVAILABLE;
+	}
+
+	service->ntds_guid = *ntds_guid;
+
+	return WERR_OK;
+}
+
+
+/*
+  load our local partition list
+ */
+static WERROR kccsrv_load_partitions(struct kccsrv_service *s)
+{
+	struct ldb_dn *basedn;
+	struct ldb_result *r;
+	struct ldb_message_element *el;
+	static const char *attrs[] = { "namingContexts", "configurationNamingContext", NULL };
+	uint32_t i;
+	int ret;
+
+	basedn = ldb_dn_new(s, s->samdb, NULL);
+	W_ERROR_HAVE_NO_MEMORY(basedn);
+
+	ret = ldb_search(s->samdb, s, &r, basedn, LDB_SCOPE_BASE, attrs,
+			 "(objectClass=*)");
+	talloc_free(basedn);
+	if (ret != LDB_SUCCESS) {
+		return WERR_FOOBAR;
+	} else if (r->count != 1) {
+		talloc_free(r);
+		return WERR_FOOBAR;
+	}
+
+	el = ldb_msg_find_element(r->msgs[0], "namingContexts");
+	if (!el) {
+		return WERR_FOOBAR;
+	}
+
+	for (i=0; el && i < el->num_values; i++) {
+		const char *v = (const char *)el->values[i].data;
+		struct ldb_dn *pdn;
+		struct kccsrv_partition *p;
+
+		pdn = ldb_dn_new(s, s->samdb, v);
+		if (!ldb_dn_validate(pdn)) {
+			return WERR_FOOBAR;
+		}
+
+		p = talloc_zero(s, struct kccsrv_partition);
+		W_ERROR_HAVE_NO_MEMORY(p);
+
+		p->dn = talloc_steal(p, pdn);
+		p->service = s;
+
+		DLIST_ADD(s->partitions, p);
+
+		DEBUG(2, ("kccsrv_partition[%s] loaded\n", v));
+	}
+
+	el = ldb_msg_find_element(r->msgs[0], "configurationNamingContext");
+	if (!el) {
+		return WERR_FOOBAR;
+	}
+	s->config_dn = ldb_dn_new(s, s->samdb, (const char *)el->values[0].data);
+	if (!ldb_dn_validate(s->config_dn)) {
+		return WERR_FOOBAR;
+	}
+
+	talloc_free(r);
+
+	return WERR_OK;
+}
+
+
+/*
+  startup the kcc service task
+*/
+static void kccsrv_task_init(struct task_server *task)
+{
+	WERROR status;
+	struct kccsrv_service *service;
+	uint32_t periodic_startup_interval;
+
+	switch (lp_server_role(task->lp_ctx)) {
+	case ROLE_STANDALONE:
+		task_server_terminate(task, "kccsrv: no KCC required in standalone configuration");
+		return;
+	case ROLE_DOMAIN_MEMBER:
+		task_server_terminate(task, "kccsrv: no KCC required in domain member configuration");
+		return;
+	case ROLE_DOMAIN_CONTROLLER:
+		/* Yes, we want a KCC */
+		break;
+	}
+
+	task_server_set_title(task, "task[kccsrv]");
+
+	service = talloc_zero(task, struct kccsrv_service);
+	if (!service) {
+		task_server_terminate(task, "kccsrv_task_init: out of memory");
+		return;
+	}
+	service->task		= task;
+	service->startup_time	= timeval_current();
+	task->private_data	= service;
+
+	status = kccsrv_init_creds(service);
+	if (!W_ERROR_IS_OK(status)) {
+		task_server_terminate(task, talloc_asprintf(task,
+				      "kccsrv: Failed to obtain server credentials: %s\n",
+				      win_errstr(status)));
+		return;
+	}
+
+	status = kccsrv_connect_samdb(service, task->lp_ctx);
+	if (!W_ERROR_IS_OK(status)) {
+		task_server_terminate(task, talloc_asprintf(task,
+				      "kccsrv: Failed to connect to local samdb: %s\n",
+				      win_errstr(status)));
+		return;
+	}
+
+	status = kccsrv_load_partitions(service);
+	if (!W_ERROR_IS_OK(status)) {
+		task_server_terminate(task, talloc_asprintf(task,
+				      "kccsrv: Failed to load partitions: %s\n",
+				      win_errstr(status)));
+		return;
+	}
+
+	periodic_startup_interval	= lp_parm_int(task->lp_ctx, NULL, "kccsrv", 
+						      "periodic_startup_interval", 15); /* in seconds */
+	service->periodic.interval	= lp_parm_int(task->lp_ctx, NULL, "kccsrv", 
+						      "periodic_interval", 300); /* in seconds */
+
+	status = kccsrv_periodic_schedule(service, periodic_startup_interval);
+	if (!W_ERROR_IS_OK(status)) {
+		task_server_terminate(task, talloc_asprintf(task,
+				      "kccsrv: Failed to periodic schedule: %s\n",
+				      win_errstr(status)));
+		return;
+	}
+
+	irpc_add_name(task->msg_ctx, "kccsrv");
+}
+
+/*
+  register ourselves as a available server
+*/
+NTSTATUS server_service_kcc_init(void)
+{
+	return register_server_service("kcc", kccsrv_task_init);
+}
diff --git a/source4/dsdb/kcc/kcc_service.h b/source4/dsdb/kcc/kcc_service.h
new file mode 100644
index 0000000000..6a78d37a91
--- /dev/null
+++ b/source4/dsdb/kcc/kcc_service.h
@@ -0,0 +1,85 @@
+/* 
+   Unix SMB/CIFS mplementation.
+
+   KCC service
+   
+   Copyright (C) Andrew Tridgell 2009
+   based on drepl service code
+    
+   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/>.
+   
+*/
+
+#ifndef _DSDB_REPL_KCC_SERVICE_H_
+#define _DSDB_REPL_KCC_SERVICE_H_
+
+#include "librpc/gen_ndr/ndr_drsuapi_c.h"
+
+struct kccsrv_partition {
+	struct kccsrv_partition *prev, *next;
+	struct kccsrv_service *service;
+
+	/* the dn of the partition */
+	struct ldb_dn *dn;
+};
+
+
+struct kccsrv_service {
+	/* the whole kcc service is in one task */
+	struct task_server *task;
+
+	/* the time the service was started */
+	struct timeval startup_time;
+
+	/* dn of our configuration partition */
+	struct ldb_dn *config_dn;
+
+	/* 
+	 * system session info
+	 * with machine account credentials
+	 */
+	struct auth_session_info *system_session_info;
+
+	/* list of local partitions */
+	struct kccsrv_partition *partitions;
+
+	/*
+	 * a connection to the local samdb
+	 */
+	struct ldb_context *samdb;
+
+	/* the guid of our NTDS Settings object, which never changes! */
+	struct GUID ntds_guid;
+
+	/* some stuff for periodic processing */
+	struct {
+		/*
+		 * the interval between to periodic runs
+		 */
+		uint32_t interval;
+
+		/*
+		 * the timestamp for the next event,
+		 * this is the timstamp passed to event_add_timed()
+		 */
+		struct timeval next_event;
+
+		/* here we have a reference to the timed event the schedules the periodic stuff */
+		struct tevent_timer *te;
+	} periodic;
+};
+
+#include "dsdb/kcc/kcc_service_proto.h"
+
+#endif /* _DSDB_REPL_KCC_SERVICE_H_ */