From 62f83b71987f054a25de4b8c8f637d6276486c09 Mon Sep 17 00:00:00 2001
From: Christian Helmuth <christian.helmuth@genode-labs.com>
Date: Tue, 25 May 2021 12:07:16 +0200
Subject: [PATCH] linux_nic_drv: optionally report MAC address

Issue #4133
---
 repos/libports/run/lwip_lx.run               | 14 +++++++++++-
 repos/os/recipes/src/linux_nic_drv/used_apis |  7 +++---
 repos/os/src/drivers/nic/spec/linux/README   |  6 +++++
 repos/os/src/drivers/nic/spec/linux/main.cc  | 24 +++++++++++++++++++-
 4 files changed, 46 insertions(+), 5 deletions(-)

diff --git a/repos/libports/run/lwip_lx.run b/repos/libports/run/lwip_lx.run
index a0581f6b39..e0cdc92afa 100644
--- a/repos/libports/run/lwip_lx.run
+++ b/repos/libports/run/lwip_lx.run
@@ -32,6 +32,7 @@ build {
 	test/lwip/http_srv
 	lib/vfs/lwip
 	server/nic_router
+	server/report_rom
 }
 
 create_boot_directory
@@ -65,10 +66,21 @@ set config {
 		<provides> <service name="Timer"/> </provides>
 	</start>
 
+	<start name="devices_report_rom">
+		<binary name="report_rom"/>
+		<resource name="RAM" quantum="1200K"/>
+		<provides> <service name="Report"/> <service name="ROM"/> </provides>
+		<config verbose="yes"/>
+	</start>
+
 	<start name="linux_nic_drv" ld="no">
 		<resource name="RAM" quantum="8M"/>
+		<config>
+			<report mac_address="true"/>
+		</config>
 		<route>
 			<service name="Uplink"> <child name="nic_router"/> </service>
+			<service name="Report"> <child name="devices_report_rom"/> </service>
 			<any-service> <parent/> </any-service>
 		</route>
 	</start>
@@ -124,7 +136,7 @@ install_config $config
 set boot_modules {
 	core init timer linux_nic_drv
 	ld.lib.so libc.lib.so vfs.lib.so vfs_lwip.lib.so test-lwip_httpsrv
-	nic_router
+	nic_router report_rom
 }
 
 build_boot_image $boot_modules
diff --git a/repos/os/recipes/src/linux_nic_drv/used_apis b/repos/os/recipes/src/linux_nic_drv/used_apis
index 37fabb6132..39602f2d5c 100644
--- a/repos/os/recipes/src/linux_nic_drv/used_apis
+++ b/repos/os/recipes/src/linux_nic_drv/used_apis
@@ -1,6 +1,7 @@
 base
 base-linux
-os
-nic_session
-uplink_session
 nic_driver
+nic_session
+os
+report_session
+uplink_session
diff --git a/repos/os/src/drivers/nic/spec/linux/README b/repos/os/src/drivers/nic/spec/linux/README
index bf073b13c6..bd47cde0bf 100644
--- a/repos/os/src/drivers/nic/spec/linux/README
+++ b/repos/os/src/drivers/nic/spec/linux/README
@@ -18,3 +18,9 @@ changed via
 
 ! <config mac="12:23:34:45:56:67"/>
 
+The driver optionally reports the following information under the
+label "devices" if requested in the config as depicted.
+
+! <config> <report mac_address="true"/> </config>
+
+! <devices> <nic label="tap0" mac_address="02:00:00:00:00:01"/> </devices>
diff --git a/repos/os/src/drivers/nic/spec/linux/main.cc b/repos/os/src/drivers/nic/spec/linux/main.cc
index 8e197cb567..6fd9ac7153 100644
--- a/repos/os/src/drivers/nic/spec/linux/main.cc
+++ b/repos/os/src/drivers/nic/spec/linux/main.cc
@@ -21,6 +21,7 @@
 #include <base/thread.h>
 #include <base/log.h>
 #include <base/blockade.h>
+#include <os/reporter.h>
 
 /* NIC driver includes */
 #include <drivers/nic/uplink_client_base.h>
@@ -204,7 +205,28 @@ struct Main
 
 	Uplink_client _uplink { _env, _heap, _tap_name, _mac_address };
 
-	Main(Env &env) : _env(env) { }
+	Constructible<Reporter> _reporter { };
+
+	Main(Env &env) : _env(env)
+	{
+		_config_rom.xml().with_sub_node("report", [&] (Xml_node const &xml) {
+			bool const report_mac_address =
+				xml.attribute_value("mac_address", false);
+
+			if (!report_mac_address)
+				return;
+
+			_reporter.construct(_env, "devices");
+			_reporter->enabled(true);
+
+			Reporter::Xml_generator report(*_reporter, [&] () {
+				report.node("nic", [&] () {
+					report.attribute("label", _tap_name);
+					report.attribute("mac_address", String<32>(_mac_address));
+				});
+			});
+		});
+	}
 };