Fix bug #8953 - winbind can hang as nbt_getdc() has no timeout.

Add a timeout_in_seconds parameter to nbt_getdc() to make it fail
after that time with NT_STATUS_IO_TIMEOUT.

4 files changed, 15 insertions, 2 deletions

diff --git a/source3/libsmb/clidgram.c b/source3/libsmb/clidgram.c
index 04964bd3f0..cfed06794d 100644
--- a/source3/libsmb/clidgram.c
+++ b/source3/libsmb/clidgram.c
@@ -437,6 +437,7 @@ NTSTATUS nbt_getdc_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 }
 
 NTSTATUS nbt_getdc(struct messaging_context *msg_ctx,
+		   uint32_t timeout_in_seconds,
 		   const struct sockaddr_storage *dc_addr,
 		   const char *domain_name,
 		   const struct dom_sid *sid,
@@ -449,6 +450,8 @@ NTSTATUS nbt_getdc(struct messaging_context *msg_ctx,
 	TALLOC_CTX *frame = talloc_stackframe();
 	struct tevent_context *ev;
 	struct tevent_req *req;
+	enum tevent_req_state err_state;
+	uint64_t error;
 	NTSTATUS status = NT_STATUS_NO_MEMORY;
 
 	ev = tevent_context_init(frame);
@@ -460,12 +463,21 @@ NTSTATUS nbt_getdc(struct messaging_context *msg_ctx,
 	if (req == NULL) {
 		goto fail;
 	}
+	if (!tevent_req_set_endtime(req, ev,
+			timeval_current_ofs(timeout_in_seconds, 0))) {
+		goto fail;
+	}
 	if (!tevent_req_poll_ntstatus(req, ev, &status)) {
 		goto fail;
 	}
 	status = nbt_getdc_recv(req, mem_ctx, pnt_version, dc_name,
 				samlogon_response);
  fail:
+	if (ev && req &&
+			tevent_req_is_error(req, &err_state, &error) &&
+			err_state == TEVENT_REQ_TIMED_OUT) {
+		status = NT_STATUS_IO_TIMEOUT;
+	}
 	TALLOC_FREE(frame);
 	return status;
 }
diff --git a/source3/libsmb/clidgram.h b/source3/libsmb/clidgram.h
index a449724a41..6cd6222df6 100644
--- a/source3/libsmb/clidgram.h
+++ b/source3/libsmb/clidgram.h
@@ -37,6 +37,7 @@ NTSTATUS nbt_getdc_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
 			uint32_t *nt_version, const char **dc_name,
 			struct netlogon_samlogon_response **samlogon_response);
 NTSTATUS nbt_getdc(struct messaging_context *msg_ctx,
+		   uint32_t timeout_in_seconds,
 		   const struct sockaddr_storage *dc_addr,
 		   const char *domain_name,
 		   const struct dom_sid *sid,
diff --git a/source3/libsmb/dsgetdcname.c b/source3/libsmb/dsgetdcname.c
index 5df833f40f..05be272450 100644
--- a/source3/libsmb/dsgetdcname.c
+++ b/source3/libsmb/dsgetdcname.c
@@ -946,7 +946,7 @@ static NTSTATUS process_dc_netbios(TALLOC_CTX *mem_ctx,
 			return NT_STATUS_UNSUCCESSFUL;
 		}
 
-		status = nbt_getdc(msg_ctx, &dclist[i].ss, domain_name,
+		status = nbt_getdc(msg_ctx, 10, &dclist[i].ss, domain_name,
 				   NULL, nt_version,
 				   mem_ctx, &nt_version, &dc_name, &r);
 		if (NT_STATUS_IS_OK(status)) {
diff --git a/source3/winbindd/winbindd_cm.c b/source3/winbindd/winbindd_cm.c
index 4188b5e6ed..cf1eb8bd0e 100644
--- a/source3/winbindd/winbindd_cm.c
+++ b/source3/winbindd/winbindd_cm.c
@@ -1161,7 +1161,7 @@ static bool dcip_to_name(TALLOC_CTX *mem_ctx,
 	}
 #endif
 
-	status = nbt_getdc(winbind_messaging_context(), pss, domain->name,
+	status = nbt_getdc(winbind_messaging_context(), 10, pss, domain->name,
 			   &domain->sid, nt_version, mem_ctx, &nt_version,
 			   &dc_name, NULL);
 	if (NT_STATUS_IS_OK(status)) {