s4:librpc/rpc: make dcerpc_bh_raw_call_* more robust against disconnects and timeouts

Using tevent_req_defer_callback() should make the situation a bit better,
until we have a common robust low level dcerpc library.

metze

Autobuild-User: Stefan Metzmacher <metze@samba.org>
Autobuild-Date: Wed Mar  7 18:44:24 CET 2012 on sn-devel-104

diff --git a/source4/librpc/rpc/dcerpc.c b/source4/librpc/rpc/dcerpc.c
index 8317778bc8e654fb92552ac43d4f4ee7645e5f58..599ad786c64f5d422a87d414693395677b6ee9de 100644 (file)
--- a/source4/librpc/rpc/dcerpc.c
+++ b/source4/librpc/rpc/dcerpc.c
@@ -194,6 +194,7 @@ static uint32_t dcerpc_bh_set_timeout(struct dcerpc_binding_handle *h,
 }
 
 struct dcerpc_bh_raw_call_state {
+       struct tevent_context *ev;
        struct dcerpc_binding_handle *h;
        DATA_BLOB in_data;
        DATA_BLOB out_data;
@@ -223,6 +224,7 @@ static struct tevent_req *dcerpc_bh_raw_call_send(TALLOC_CTX *mem_ctx,
        if (req == NULL) {
                return NULL;
        }
+       state->ev = ev;
        state->h = h;
        state->in_data.data = discard_const_p(uint8_t, in_data);
        state->in_data.length = in_length;
@@ -268,6 +270,19 @@ static void dcerpc_bh_raw_call_done(struct rpc_request *subreq)
        if (NT_STATUS_EQUAL(status, NT_STATUS_NET_WRITE_FAULT)) {
                status = dcerpc_fault_to_nt_status(fault_code);
        }
+
+       /*
+        * We trigger the callback in the next event run
+        * because the code in this file might trigger
+        * multiple request callbacks from within a single
+        * while loop.
+        *
+        * In order to avoid segfaults from within
+        * dcerpc_connection_dead() we call
+        * tevent_req_defer_callback().
+        */
+       tevent_req_defer_callback(req, state->ev);
+
        if (!NT_STATUS_IS_OK(status)) {
                tevent_req_nterror(req, status);
                return;