s4-dns: implemented RODC DNS update in dns update task

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

1 files changed, 199 insertions, 0 deletions

diff --git a/source4/dsdb/dns/dns_update.c b/source4/dsdb/dns/dns_update.c
index e9f93038b6..fbfca192ba 100644
--- a/source4/dsdb/dns/dns_update.c
+++ b/source4/dsdb/dns/dns_update.c
@@ -36,6 +36,8 @@
 #include "param/param.h"
 #include "system/filesys.h"
 #include "libcli/composite/composite.h"
+#include "libcli/security/dom_sid.h"
+#include "librpc/gen_ndr/ndr_irpc.h"
 
 struct dnsupdate_service {
 	struct task_server *task;
@@ -347,6 +349,200 @@ static NTSTATUS dnsupdate_nameupdate_schedule(struct dnsupdate_service *service)
 	return NT_STATUS_OK;
 }
 
+
+struct dnsupdate_RODC_state {
+	struct irpc_message *msg;
+	struct dnsupdate_RODC *r;
+	char *tmp_path;
+	int fd;
+};
+
+static int dnsupdate_RODC_destructor(struct dnsupdate_RODC_state *st)
+{
+	if (st->fd != -1) {
+		close(st->fd);
+	}
+	unlink(st->tmp_path);
+	return 0;
+}
+
+/*
+  called when the DNS update has completed
+ */
+static void dnsupdate_RODC_callback(struct tevent_req *req)
+{
+	struct dnsupdate_RODC_state *st =
+		tevent_req_callback_data(req,
+					 struct dnsupdate_RODC_state);
+	int sys_errno;
+	int i, ret;
+
+	ret = samba_runcmd_recv(req, &sys_errno);
+	talloc_free(req);
+	if (ret != 0) {
+		st->r->out.result = map_nt_error_from_unix(sys_errno);
+		DEBUG(2,(__location__ ": RODC DNS Update failed: %s\n", nt_errstr(st->r->out.result)));
+	} else {
+		st->r->out.result = NT_STATUS_OK;
+		DEBUG(3,(__location__ ": RODC DNS Update OK\n"));
+	}
+
+	for (i=0; i<st->r->in.dns_names->count; i++) {
+		st->r->out.dns_names->names[i].status = NT_STATUS_V(st->r->out.result);
+	}
+
+	irpc_send_reply(st->msg, NT_STATUS_OK);
+}
+
+
+/**
+ * Called when we get a RODC DNS update request from the netlogon
+ * rpc server
+ */
+static NTSTATUS dnsupdate_dnsupdate_RODC(struct irpc_message *msg,
+					 struct dnsupdate_RODC *r)
+{
+	struct dnsupdate_service *s = talloc_get_type(msg->private_data,
+						      struct dnsupdate_service);
+	const char * const *dns_update_command = lpcfg_dns_update_command(s->task->lp_ctx);
+	struct dnsupdate_RODC_state *st;
+	struct tevent_req *req;
+	int i, ret;
+	struct GUID ntds_guid;
+	const char *site, *dnsdomain, *dnsforest, *ntdsguid, *hostname;
+	struct ldb_dn *sid_dn;
+	const char *attrs[] = { "dNSHostName", NULL };
+	struct ldb_result *res;
+
+	st = talloc_zero(msg, struct dnsupdate_RODC_state);
+	if (!st) {
+		r->out.result = NT_STATUS_NO_MEMORY;
+		return NT_STATUS_OK;
+	}
+
+	st->r = r;
+	st->msg = msg;
+
+	st->tmp_path = smbd_tmp_path(st, s->task->lp_ctx, "rodcdns.XXXXXX");
+	if (!st->tmp_path) {
+		talloc_free(st);
+		r->out.result = NT_STATUS_NO_MEMORY;
+		return NT_STATUS_OK;
+	}
+
+	st->fd = mkstemp(st->tmp_path);
+	if (st->fd == -1) {
+		DEBUG(0,("Unable to create a temporary file for RODC dnsupdate\n"));
+		talloc_free(st);
+		r->out.result = NT_STATUS_INTERNAL_DB_CORRUPTION;
+		return NT_STATUS_OK;
+	}
+
+	talloc_set_destructor(st, dnsupdate_RODC_destructor);
+
+	sid_dn = ldb_dn_new_fmt(st, s->samdb, "<SID=%s>", dom_sid_string(st, r->in.dom_sid));
+	if (!sid_dn) {
+		talloc_free(st);
+		r->out.result = NT_STATUS_NO_MEMORY;
+		return NT_STATUS_OK;
+	}
+
+	/* work out the site */
+	ret = samdb_find_site_for_computer(s->samdb, st, sid_dn, &site);
+	if (ret != LDB_SUCCESS) {
+		DEBUG(2, (__location__ ": Unable to find site for computer %s\n",
+			  ldb_dn_get_linearized(sid_dn)));
+		talloc_free(st);
+		r->out.result = NT_STATUS_NO_SUCH_USER;
+		return NT_STATUS_OK;
+	}
+
+	/* work out the ntdsguid */
+	ret = samdb_find_ntdsguid_for_computer(s->samdb, sid_dn, &ntds_guid);
+	ntdsguid = GUID_string(st, &ntds_guid);
+	if (ret != LDB_SUCCESS || !ntdsguid) {
+		DEBUG(2, (__location__ ": Unable to find NTDS GUID for computer %s\n",
+			  ldb_dn_get_linearized(sid_dn)));
+		talloc_free(st);
+		r->out.result = NT_STATUS_NO_SUCH_USER;
+		return NT_STATUS_OK;
+	}
+
+
+	/* find dnsdomain and dnsforest */
+	dnsdomain = lpcfg_realm(s->task->lp_ctx);
+	dnsforest = dnsdomain;
+
+	/* find the hostname */
+	ret = dsdb_search_dn(s->samdb, st, &res, sid_dn, attrs, 0);
+	if (ret == LDB_SUCCESS) {
+		hostname = ldb_msg_find_attr_as_string(res->msgs[0], "dNSHostName", NULL);
+	}
+	if (ret != LDB_SUCCESS || !hostname) {
+		DEBUG(2, (__location__ ": Unable to find NTDS GUID for computer %s\n",
+			  ldb_dn_get_linearized(sid_dn)));
+		talloc_free(st);
+		r->out.result = NT_STATUS_NO_SUCH_USER;
+		return NT_STATUS_OK;
+	}
+
+
+	for (i=0; i<st->r->in.dns_names->count; i++) {
+		struct NL_DNS_NAME_INFO *n = &r->in.dns_names->names[i];
+		switch (n->type) {
+		case NlDnsLdapAtSite:
+			dprintf(st->fd, "SRV _ldap._tcp.%s._sites.%s. %s %u\n",
+				site, dnsdomain, hostname, n->port);
+			break;
+		case NlDnsGcAtSite:
+			dprintf(st->fd, "SRV _ldap._tcp.%s._sites.gc._msdcs.%s. %s %u\n",
+				site, dnsdomain, hostname, n->port);
+			break;
+		case NlDnsDsaCname:
+			dprintf(st->fd, "CNAME %s._msdcs.%s. %s\n",
+				ntdsguid, dnsforest, hostname);
+			break;
+		case NlDnsKdcAtSite:
+			dprintf(st->fd, "SRV _kerberos._tcp.%s._sites.dc._msdcs.%s. %s %u\n",
+				site, dnsdomain, hostname, n->port);
+			break;
+		case NlDnsDcAtSite:
+			dprintf(st->fd, "SRV _ldap._tcp.%s._sites.dc._msdcs.%s. %s %u\n",
+				site, dnsdomain, hostname, n->port);
+			break;
+		case NlDnsRfc1510KdcAtSite:
+			dprintf(st->fd, "SRV _kerberos._tcp.%s._sites.%s. %s %u\n",
+				site, dnsdomain, hostname, n->port);
+			break;
+		case NlDnsGenericGcAtSite:
+			dprintf(st->fd, "SRV _gc._tcp.%s._sites.%s. %s %u\n",
+				site, dnsforest, hostname, n->port);
+			break;
+		}
+	}
+
+	close(st->fd);
+	st->fd = -1;
+
+	DEBUG(3,("Calling RODC DNS name update script %s\n", st->tmp_path));
+	req = samba_runcmd_send(st,
+				s->task->event_ctx,
+				timeval_current_ofs(20, 0),
+				2, 0,
+				dns_update_command,
+				"--update-list",
+				st->tmp_path,
+				NULL);
+	NT_STATUS_HAVE_NO_MEMORY(req);
+
+	/* setup the callback */
+	tevent_req_set_callback(req, dnsupdate_RODC_callback, st);
+
+	msg->defer_reply = true;
+
+	return NT_STATUS_OK;
+}
+
 /*
   startup the dns update task
 */
@@ -412,6 +608,9 @@ static void dnsupdate_task_init(struct task_server *task)
 
 	irpc_add_name(task->msg_ctx, "dnsupdate");
 
+	IRPC_REGISTER(task->msg_ctx, irpc, DNSUPDATE_RODC,
+		      dnsupdate_dnsupdate_RODC, service);
+
 	/* create the intial file */
 	dnsupdate_rebuild(service);