Adaptation to init refactoring

Since init no longer provides public headers, we have to adjust the
existing users of this headers. The 'init/child_config.h' is used only
by GDB monitor. So the patch moves the header there as an interim fix.
The 'init/child_policy.h' is still used by a few components, so we have
to keep a trimmed-down version of it for now.

repos/demo/include/launchpad/launchpad.h

@@ -19,12 +19,15 @@
 #ifndef _INCLUDE__LAUNCHPAD__LAUNCHPAD_H_
 #define _INCLUDE__LAUNCHPAD__LAUNCHPAD_H_
 
+#include <util/xml_node.h>
 #include <base/allocator.h>
 #include <base/service.h>
 #include <base/lock.h>
+#include <base/child.h>
 #include <timer_session/timer_session.h>
 #include <pd_session/client.h>
-#include <init/child.h>
+#include <init/child_policy.h>
+#include <os/session_requester.h>
 
 class Launchpad;
 

repos/os/include/init/child_policy.h

@@ -1,7 +1,9 @@
 /*
- * \brief  Policy applied to all children of the init process
+ * \brief  Child-policy helpers
  * \author Norman Feske
  * \date   2010-04-29
+ *
+ * \deprecated  use os/dynamic_rom_session.h instead
  */
 
 /*
@@ -15,104 +17,16 @@
 #define _INCLUDE__INIT__CHILD_POLICY_H_
 
 /* Genode includes */
+#include <base/rpc_server.h>
 #include <base/service.h>
-#include <base/child.h>
+#include <rom_session/rom_session.h>
-#include <base/session_label.h>
-#include <base/attached_ram_dataspace.h>
-#include <util/arg_string.h>
-#include <rom_session/connection.h>
-#include <base/session_label.h>
-#include <os/dynamic_rom_session.h>
 
 namespace Init {
-
-	class Child_policy_ram_phys;
-	class Child_policy_handle_cpu_priorities;
 	class Child_policy_provide_rom_file;
-	class Child_policy_provide_dynamic_rom;
-	class Child_policy_redirect_rom_file;
-	class Traditional_child_policy;
-
 	using namespace Genode;
-	using Genode::size_t;
-	using Genode::strcmp;
-	using Genode::snprintf;
 }
 
 
-class Init::Child_policy_ram_phys
-{
-	private:
-
-		bool _constrain_phys;
-
-	public:
-
-		Child_policy_ram_phys(bool constrain_phys)
-		: _constrain_phys(constrain_phys) { }
-
-		/**
-		 * Filter arguments of session request
-		 *
-		 * This method removes phys_start and phys_size ram_session
-		 * parameters if the child configuration does not explicitly
-		 * permits this.
-		 */
-		void filter_session_args(const char *service, char *args,
-		                         size_t args_len)
-		{
-			/* intercept only RAM session requests */
-			if (strcmp(service, "RAM"))
-				return;
-
-			if (_constrain_phys)
-				return;
-
-			Arg_string::remove_arg(args, "phys_start");
-			Arg_string::remove_arg(args, "phys_size");
-		}
-};
-
-
-class Init::Child_policy_handle_cpu_priorities
-{
-	/* priority parameters */
-	long _prio_levels_log2;
-	long _priority;
-
-	public:
-
-		Child_policy_handle_cpu_priorities(long prio_levels_log2, long priority)
-		: _prio_levels_log2(prio_levels_log2), _priority(priority) { }
-
-		void filter_session_args(const char *service, char *args, size_t args_len)
-		{
-			/* intercept only CPU session requests to scale priorities */
-			if (strcmp(service, "CPU") || _prio_levels_log2 == 0)
-				return;
-
-			unsigned long priority = Arg_string::find_arg(args, "priority").ulong_value(0);
-
-			/* clamp priority value to valid range */
-			priority = min((unsigned)Cpu_session::PRIORITY_LIMIT - 1, priority);
-
-			long discarded_prio_lsb_bits_mask = (1 << _prio_levels_log2) - 1;
-			if (priority & discarded_prio_lsb_bits_mask) {
-				warning("priority band too small, losing least-significant priority bits");
-			}
-			priority >>= _prio_levels_log2;
-
-			/* assign child priority to the most significant priority bits */
-			priority |= _priority*(Cpu_session::PRIORITY_LIMIT >> _prio_levels_log2);
-
-			/* override priority when delegating the session request to the parent */
-			char value_buf[64];
-			snprintf(value_buf, sizeof(value_buf), "0x%lx", priority);
-			Arg_string::set_arg(args, args_len, "priority", value_buf);
-		}
-};
-
-
 class Init::Child_policy_provide_rom_file
 {
 	private:
@@ -177,46 +91,4 @@ class Init::Child_policy_provide_rom_file
 		}
 };
 
-
-class Init::Child_policy_redirect_rom_file
-{
-	private:
-
-		char const *_from;
-		char const *_to;
-
-	public:
-
-		Child_policy_redirect_rom_file(const char *from, const char *to)
-		: _from(from), _to(to) { }
-
-		void filter_session_args(const char *service,
-		                         char *args, size_t args_len)
-		{
-			if (!_from || !_to) return;
-
-			/* ignore session requests for non-ROM services */
-			if (strcmp(service, "ROM")) return;
-
-			/* drop out if request refers to another module name */
-			Session_label const label = label_from_args(args);
-			Session_label const from(_from);
-			if (from != label.last_element()) return;
-
-			/*
-			 * The module name corresponds to the last part of the label.
-			 * We have to replace this part with the 'to' module name.
-			 * If the label consists of only the module name but no prefix,
-			 * we replace the entire label with the 'to' module name.
-			 */
-			Session_label const prefix = label.prefix();
-			Session_label const to(_to);
-
-			Session_label const prefixed_to =
-				prefixed_label(prefix.valid() ? prefix : Session_label(), to);
-
-			Arg_string::set_arg_string(args, args_len, "label", prefixed_to.string());
-		}
-};
-
 #endif /* _INCLUDE__INIT__CHILD_POLICY_H_ */

repos/ports/src/app/gdb_monitor/app_child.h

@@ -18,7 +18,6 @@
 #include <base/child.h>
 #include <base/service.h>
 
-#include <init/child_config.h>
 #include <init/child_policy.h>
 
 #include <util/arg_string.h>
@@ -28,6 +27,7 @@
 #include "cpu_session_component.h"
 #include "pd_session_component.h"
 #include "rom.h"
+#include "child_config.h"
 
 namespace Gdb_monitor {
 	using namespace Genode;

repos/ports/src/app/gdb_monitor/child_config.h

@@ -0,0 +1,138 @@
+/*
+ * \brief  Utility for handling child configuration
+ * \author Norman Feske
+ * \date   2008-03-22
+ */
+
+/*
+ * Copyright (C) 2008-2017 Genode Labs GmbH
+ *
+ * This file is part of the Genode OS framework, which is distributed
+ * under the terms of the GNU Affero General Public License version 3.
+ */
+
+#ifndef _CHILD_CONFIG_H_
+#define _CHILD_CONFIG_H_
+
+#warning header is deprecated, used os/dynamic_rom_session.h instead
+
+#include <util/xml_node.h>
+#include <base/attached_dataspace.h>
+#include <ram_session/ram_session.h>
+
+namespace Init { class Child_config; }
+
+
+class Init::Child_config
+{
+	private:
+
+		Genode::Ram_session &_ram;
+
+		typedef Genode::String<64> Rom_name;
+		Rom_name const _rom_name;
+
+		Genode::Ram_dataspace_capability const _ram_ds;
+
+		Rom_name _rom_name_from_start_node(Genode::Xml_node start)
+		{
+			if (!start.has_sub_node("configfile"))
+				return Rom_name();
+
+			return start.sub_node("configfile").attribute_value("name", Rom_name());
+		}
+
+		/**
+		 * Buffer '<config>' sub node in a dedicated RAM dataspace
+		 *
+		 * \throw Ram_session::Alloc_failed
+		 * \throw Rm_session::Attach_failed
+		 */
+		Genode::Ram_dataspace_capability
+		_ram_ds_from_start_node(Genode::Xml_node start,
+		                        Genode::Ram_session &ram, Genode::Region_map &rm)
+		{
+			/*
+			 * If the start node contains a 'config' entry, we copy this entry
+			 * into a fresh dataspace to be provided to our child.
+			 */
+			Genode::Xml_node const config = start.has_sub_node("config")
+			                              ? start.sub_node("config")
+			                              : Genode::Xml_node("<config/>");
+
+			Genode::Ram_dataspace_capability ram_ds;
+			try {
+				/*
+				 * Allocate RAM dataspace that is big enough to hold the
+				 * configuration and the null termination.
+				 */
+				ram_ds = ram.alloc(config.size() + 1);
+
+				/*
+				 * Make dataspace locally accessible, copy configuration into the
+				 * dataspace, and append a string-terminating zero.
+				 */
+				Genode::Attached_dataspace attached(rm, ram_ds);
+
+				Genode::memcpy(attached.local_addr<char>(),
+				               config.addr(), config.size());
+
+				attached.local_addr<char>()[config.size()] = 0;
+
+				return ram_ds;
+			}
+			catch (Genode::Region_map::Attach_failed) { ram.free(ram_ds); throw; }
+		}
+
+	public:
+
+		/**
+		 * Constructor
+		 *
+		 * The provided RAM session is used to obtain a dataspace for
+		 * holding the copy of the child's configuration data unless the
+		 * configuration is supplied via a config ROM module.
+		 *
+		 * \throw Ram_session::Alloc_failed  failed to allocate the backing
+		 *                                   store for holding config data
+		 *
+		 * \throw Region_map::Attach_failed  failed to temporarily attach the
+		 *                                   config dataspace to the local
+		 *                                   address space
+		 *
+		 * If the start node contains a 'filename' entry, we only keep the
+		 * information about the ROM module name.
+		 */
+		Child_config(Genode::Ram_session &ram, Genode::Region_map &local_rm,
+		             Genode::Xml_node start)
+		:
+			_ram(ram),
+			_rom_name(_rom_name_from_start_node(start)),
+			_ram_ds(_rom_name.valid() ? Genode::Ram_dataspace_capability()
+			                          : _ram_ds_from_start_node(start, ram, local_rm))
+		{ }
+
+		/**
+		 * Destructor
+		 */
+		~Child_config() { if (_ram_ds.valid()) _ram.free(_ram_ds); }
+
+		/**
+		 * Return file name if configuration comes from a file
+		 *
+		 * If the configuration is provided inline, the method returns 0.
+		 */
+		char const *filename() const {
+			return _rom_name.valid() ? _rom_name.string() : nullptr; }
+
+		/**
+		 * Request dataspace holding the start node's configuration data
+		 *
+		 * This method returns a valid dataspace only when using an
+		 * inline configuration (if 'filename()' returns 0).
+		 */
+		Genode::Dataspace_capability dataspace() {
+			return Genode::Dataspace_capability(_ram_ds); }
+};
+
+#endif /* _CHILD_CONFIG_H_ */