added a basic dcerpc endpoint mapper to Samba4. Currently only

implements the epm_Lookup() call, I'll add the other important calls
soon. I was rather pleased to find that epm_Lookup() worked first
time, which is particularly surprising given its complexity.

This required quite a bit of new infrastructure:

  * a generic way of handling dcerpc policy handles in the rpc server

  * added type checked varients of talloc. These are much less error
    prone. I'd like to move to using these for nearly all uses of
    talloc.

  * added more dcerpc fault handling code, and translation from
    NTSTATUS to a dcerpc fault code

  * added data_blob_talloc_zero() for allocating an initially zero
    blob

  * added a endpoint enumeration hook in the dcerpc endpoint server
    operations

source/rpc_server/handles.c

@@ -0,0 +1,92 @@
+/* 
+   Unix SMB/CIFS implementation.
+
+   server side dcerpc handle code
+
+   Copyright (C) Andrew Tridgell 2003
+   
+   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 2 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#include "includes.h"
+
+/*
+  allocate a new rpc handle
+*/
+struct dcesrv_handle *dcesrv_handle_new(struct dcesrv_state *dce, 
+					uint8 handle_type)
+{
+	TALLOC_CTX *mem_ctx;
+	struct dcesrv_handle *h;
+
+	mem_ctx = talloc_init("rpc handle type %d\n", handle_type);
+	if (!mem_ctx) {
+		return NULL;
+	}
+	h = talloc(mem_ctx, sizeof(*h));
+	if (!h) {
+		talloc_destroy(mem_ctx);
+		return NULL;
+	}
+	h->mem_ctx = mem_ctx;
+	h->data = NULL;
+
+	memset(h->wire_handle.data, 'H', sizeof(h->wire_handle.data));
+	strncpy(h->wire_handle.data, dce->ndr->name, 11);
+	h->wire_handle.data[11] = handle_type;
+	
+	/* TODO: check for wraparound here */
+	SIVAL(&h->wire_handle.data, 12, random());
+	SIVAL(&h->wire_handle.data, 16, dce->next_handle);
+	dce->next_handle++;	
+
+	DLIST_ADD(dce->handles, h);
+
+	return h;
+}
+
+/*
+  destroy a rpc handle
+*/
+void dcesrv_handle_destroy(struct dcesrv_state *dce, 
+			   struct dcesrv_handle *h)
+{
+	DLIST_REMOVE(dce->handles, h);
+	talloc_destroy(h->mem_ctx);
+}
+
+
+/*
+  find an internal handle given a wire handle. If the wire handle is NULL then
+  allocate a new handle
+*/
+struct dcesrv_handle *dcesrv_handle_fetch(struct dcesrv_state *dce, 
+					  struct policy_handle *p,
+					  uint8 handle_type)
+{
+	struct dcesrv_handle *h;
+
+	if (all_zero(p->data, sizeof(p->data))) {
+		return dcesrv_handle_new(dce, handle_type);
+	}
+
+	for (h=dce->handles; h; h=h->next) {
+		if (memcmp(h->wire_handle.data, p->data, sizeof(p->data)) == 0) {
+			return h;
+		}
+	}
+
+	return NULL;
+}