s4-kcc: we should only add to the repsFrom if it doesn't already exist

If we already have a repsFrom for a particular DC and naming context
then we should not overwrite it, as it contains info on what
replication we've already done

2 files changed, 182 insertions, 45 deletions

diff --git a/source4/dsdb/common/util.c b/source4/dsdb/common/util.c
index 6da02b0b6a..b5005444cc 100644
--- a/source4/dsdb/common/util.c
+++ b/source4/dsdb/common/util.c
@@ -36,6 +36,7 @@
 #include "libcli/ldap/ldap_ndr.h"
 #include "param/param.h"
 #include "libcli/auth/libcli_auth.h"
+#include "librpc/gen_ndr/ndr_drsblobs.h"
 
 /*
   search the sam for the specified attributes in a specific domain, filter on
@@ -2146,3 +2147,113 @@ int dsdb_find_guid_by_dn(struct ldb_context *ldb,
 	talloc_free(tmp_ctx);
 	return LDB_SUCCESS;
 }
+
+
+
+/*
+  load a repsFromTo blob list for a given partition GUID
+  attr must be "repsFrom" or "repsTo"
+ */
+WERROR dsdb_loadreps(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx, struct ldb_dn *dn,
+		     const char *attr, struct repsFromToBlob **r, uint32_t *count)
+{
+	const char *attrs[] = { attr, NULL };
+	struct ldb_result *res = NULL;
+	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
+	int i;
+	struct ldb_message_element *el;
+
+	*r = NULL;
+	*count = 0;
+
+	if (ldb_search(sam_ctx, tmp_ctx, &res, dn, LDB_SCOPE_BASE, attrs, NULL) != LDB_SUCCESS ||
+	    res->count < 1) {
+		DEBUG(0,("dsdb_loadreps: failed to read partition object\n"));
+		talloc_free(tmp_ctx);
+		return WERR_DS_DRA_INTERNAL_ERROR;
+	}
+
+	el = ldb_msg_find_element(res->msgs[0], attr);
+	if (el == NULL) {
+		/* it's OK to be empty */
+		talloc_free(tmp_ctx);
+		return WERR_OK;
+	}
+
+	*count = el->num_values;
+	*r = talloc_array(mem_ctx, struct repsFromToBlob, *count);
+	if (*r == NULL) {
+		talloc_free(tmp_ctx);
+		return WERR_DS_DRA_INTERNAL_ERROR;
+	}
+
+	for (i=0; i<(*count); i++) {
+		enum ndr_err_code ndr_err;
+		ndr_err = ndr_pull_struct_blob(&el->values[i], 
+					       mem_ctx, lp_iconv_convenience(ldb_get_opaque(sam_ctx, "loadparm")),
+					       &(*r)[i], 
+					       (ndr_pull_flags_fn_t)ndr_pull_repsFromToBlob);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			talloc_free(tmp_ctx);
+			return WERR_DS_DRA_INTERNAL_ERROR;
+		}
+	}
+
+	talloc_free(tmp_ctx);
+	
+	return WERR_OK;
+}
+
+/*
+  save the repsFromTo blob list for a given partition GUID
+  attr must be "repsFrom" or "repsTo"
+ */
+WERROR dsdb_savereps(struct ldb_context *sam_ctx, TALLOC_CTX *mem_ctx, struct ldb_dn *dn,
+		     const char *attr, struct repsFromToBlob *r, uint32_t count)
+{
+	TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
+	struct ldb_message *msg;
+	struct ldb_message_element *el;
+	int i;
+
+	msg = ldb_msg_new(tmp_ctx);
+	msg->dn = dn;
+	if (ldb_msg_add_empty(msg, attr, LDB_FLAG_MOD_REPLACE, &el) != LDB_SUCCESS) {
+		goto failed;
+	}
+
+	el->values = talloc_array(msg, struct ldb_val, count);
+	if (!el->values) {
+		goto failed;
+	}
+
+	for (i=0; i<count; i++) {
+		struct ldb_val v;
+		enum ndr_err_code ndr_err;
+
+		ndr_err = ndr_push_struct_blob(&v, tmp_ctx, lp_iconv_convenience(ldb_get_opaque(sam_ctx, "loadparm")),
+					       &r[i], 
+					       (ndr_push_flags_fn_t)ndr_push_repsFromToBlob);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			goto failed;
+		}
+
+		el->num_values++;
+		el->values[i] = v;
+	}
+
+	if (ldb_modify(sam_ctx, msg) != LDB_SUCCESS) {
+		DEBUG(0,("Failed to store %s - %s\n", attr, ldb_errstring(sam_ctx)));
+		goto failed;
+	}
+
+	talloc_free(tmp_ctx);
+	
+	return WERR_OK;
+
+failed:
+	talloc_free(tmp_ctx);
+	return WERR_DS_DRA_INTERNAL_ERROR;
+}
+
+
diff --git a/source4/dsdb/kcc/kcc_periodic.c b/source4/dsdb/kcc/kcc_periodic.c
index 649efd51ca..3af79d8b89 100644
--- a/source4/dsdb/kcc/kcc_periodic.c
+++ b/source4/dsdb/kcc/kcc_periodic.c
@@ -35,11 +35,71 @@
 #include "param/param.h"
 
 /*
- * add a repsFrom to all our partitions
+ * see if a repsFromToBlob is in a list
  */
+static bool reps_in_list(struct repsFromToBlob *r, struct repsFromToBlob *reps, uint32_t count)
+{
+	int i;
+	for (i=0; i<count; i++) {
+		if (strcmp(r->ctr.ctr1.other_info->dns_name, 
+			   reps[i].ctr.ctr1.other_info->dns_name) == 0 &&
+		    GUID_compare(&r->ctr.ctr1.source_dsa_obj_guid, 
+				 &reps[i].ctr.ctr1.source_dsa_obj_guid) == 0) {
+			return true;
+		}
+	}
+	return false;
+}
 
 
 /*
+ * add any missing repsFrom structures to our partitions
+ */
+static NTSTATUS kccsrv_add_repsFrom(struct kccsrv_service *s, TALLOC_CTX *mem_ctx,
+				    struct repsFromToBlob *reps, uint32_t count)
+{
+	struct kccsrv_partition *p;
+
+	/* update the repsFrom on all partitions */
+	for (p=s->partitions; p; p=p->next) {
+		struct repsFromToBlob *old_reps;
+		uint32_t old_count;
+		WERROR werr;
+		int i;
+		bool modified = false;
+
+		werr = dsdb_loadreps(s->samdb, mem_ctx, p->dn, "repsFrom", &old_reps, &old_count);
+		if (!W_ERROR_IS_OK(werr)) {
+			DEBUG(0,(__location__ ": Failed to load repsFrom from %s - %s\n", 
+				 ldb_dn_get_linearized(p->dn), ldb_errstring(s->samdb)));
+			return NT_STATUS_INTERNAL_DB_CORRUPTION;
+		}
+
+		for (i=0; i<count; i++) {
+			if (!reps_in_list(&reps[i], old_reps, old_count)) {
+				old_reps = talloc_realloc(mem_ctx, old_reps, struct repsFromToBlob, old_count+1);
+				NT_STATUS_HAVE_NO_MEMORY(old_reps);
+				old_reps[old_count] = reps[i];
+				old_count++;
+				modified = true;
+			}
+		}
+		
+		if (modified) {
+			werr = dsdb_savereps(s->samdb, mem_ctx, p->dn, "repsFrom", old_reps, old_count);
+			if (!W_ERROR_IS_OK(werr)) {
+				DEBUG(0,(__location__ ": Failed to save repsFrom to %s - %s\n", 
+					 ldb_dn_get_linearized(p->dn), ldb_errstring(s->samdb)));
+				return NT_STATUS_INTERNAL_DB_CORRUPTION;
+			}
+		}
+	}
+
+	return NT_STATUS_OK;
+
+}
+
+/*
   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
@@ -49,9 +109,8 @@ static NTSTATUS kccsrv_simple_update(struct kccsrv_service *s, TALLOC_CTX *mem_c
 	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;
+	struct repsFromToBlob *reps = NULL;
+	uint32_t count = 0;
 
 	ret = ldb_search(s->samdb, mem_ctx, &res, s->config_dn, LDB_SCOPE_SUBTREE, 
 			 attrs, "objectClass=nTDSDSA");
@@ -60,21 +119,10 @@ static NTSTATUS kccsrv_simple_update(struct kccsrv_service *s, TALLOC_CTX *mem_c
 		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) {
@@ -84,10 +132,13 @@ static NTSTATUS kccsrv_simple_update(struct kccsrv_service *s, TALLOC_CTX *mem_c
 
 		invocation_id = samdb_result_guid(res->msgs[i], "invocationID");
 
-		ZERO_STRUCT(r);
+		reps = talloc_realloc(mem_ctx, reps, struct repsFromToBlob, count+1);
+		NT_STATUS_HAVE_NO_MEMORY(reps);
+
+		ZERO_STRUCT(reps[count]);
 		ZERO_STRUCT(oi);
-		r.version = 1;
-		r1 = &r.ctr.ctr1;
+		reps[count].version = 1;
+		r1 = &reps[count].ctr.ctr1;
 
 		oi.dns_name                  = talloc_asprintf(mem_ctx, "%s._msdcs.%s",
 							       GUID_string(mem_ctx, &ntds_guid),
@@ -100,35 +151,10 @@ static NTSTATUS kccsrv_simple_update(struct kccsrv_service *s, TALLOC_CTX *mem_c
 			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;
-		}
+		count++;
 	}
 
-	return NT_STATUS_OK;
+	return kccsrv_add_repsFrom(s, mem_ctx, reps, count);
 }