lib/vfs/lxip: support configuration of MTU

The MTU can be set via the "mtu" attribute like follows.

  <vfs> <lxip mtu="1200" dhcp="yes"/> </vfs>

repos/dde_linux/run/vfs_cfg.run

@@ -54,7 +54,7 @@ append config {
 			<sleep milliseconds="2500"/> <inline description="dynamic">
 			<config>
 				<vfs>
-					<lxip dhcp="yes"/>
+					<lxip mtu="1000" dhcp="yes"/>
 				</vfs>
 			</config>
 			</inline>

repos/dde_linux/src/lib/lxip/driver.c

@@ -31,7 +31,7 @@ static int driver_net_open(struct net_device *dev)
 }
 
 
-int driver_net_xmit(struct sk_buff *skb, struct net_device *dev)
+static int driver_net_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct net_device_stats *stats = (struct net_device_stats*) netdev_priv(dev);
 	int len                        = skb->len;
@@ -56,10 +56,18 @@ int driver_net_xmit(struct sk_buff *skb, struct net_device *dev)
 }
 
 
+static int driver_change_mtu(struct net_device *dev, int new_mtu)
+{
+	/* possible point to reflect successful MTU setting */
+	return eth_change_mtu(dev, new_mtu);
+}
+
+
 static const struct net_device_ops driver_net_ops =
 {
 	.ndo_open       = driver_net_open,
 	.ndo_start_xmit = driver_net_xmit,
+	.ndo_change_mtu = driver_change_mtu,
 };
 
 

repos/dde_linux/src/lib/lxip/lx.h

@@ -47,6 +47,7 @@ extern "C" void lxip_configure_static(char const *addr,
                                       char const *gateway,
                                       char const *nameserver);
 extern "C" void lxip_configure_dhcp();
+extern "C" void lxip_configure_mtu(unsigned mtu);
 
 extern "C" bool lxip_do_dhcp();
 

repos/dde_linux/src/lib/lxip/lxc_emul.c

@@ -528,6 +528,22 @@ static void lxip_configure(char const *address_config)
 static bool dhcp_configured = false;
 static bool dhcp_pending    = false;
 
+void lxip_configure_mtu(unsigned mtu)
+{
+	/* zero mtu means reset to default */
+	unsigned new_mtu = mtu ? mtu : ETH_DATA_LEN;
+
+	struct net        *net;
+	struct net_device *dev;
+
+	for_each_net(net) {
+		for_each_netdev(net, dev) {
+			dev_set_mtu(dev, new_mtu);
+		}
+	}
+}
+
+
 void lxip_configure_static(char const *addr, char const *netmask,
                            char const *gateway, char const *nameserver)
 {

repos/dde_linux/src/lib/vfs/lxip/vfs.cc

@@ -1393,15 +1393,19 @@ class Vfs::Lxip_file_system : public Vfs::File_system,
 		{
 			typedef String<16> Addr;
 
-			try {
+			unsigned const mtu = config.attribute_value("mtu", 0U);
+			if (mtu) {
+				log("Setting MTU to ", mtu);
+				lxip_configure_mtu(mtu);
+			} else {
+				lxip_configure_mtu(0);
+			}
 
-				if (config.attribute_value("dhcp", false)) {
+			if (config.attribute_value("dhcp", false)) {
-					log("Using DHCP for interface configuration.");
+				log("Using DHCP for interface configuration.");
-					lxip_configure_dhcp();
+				lxip_configure_dhcp();
-					return;
+				return;
-				}
+			}
-
-			} catch (...) { }
 
 			try {
 
@@ -1426,7 +1430,7 @@ class Vfs::Lxip_file_system : public Vfs::File_system,
 
 				lxip_configure_static(ip_addr.string(), netmask.string(),
 				                      gateway.string(), nameserver.string());
-			} catch (...) {	}
+			} catch (...) { }
 		 }
 
 

repos/libports/run/netty.inc

@@ -1,11 +1,15 @@
 assert_spec x86
 
+proc use_dynamic_rom { } { return true }
+
 set build_components {
 	core init
-	drivers/timer drivers/nic server/ram_fs server/vfs
+	drivers/timer drivers/nic server/vfs
 	lib/vfs/lxip
 }
 
+lappend_if [use_dynamic_rom] build_components server/dynamic_rom
+
 source ${genode_dir}/repos/base/run/platform_drv.inc
 append_platform_drv_build_components
 
@@ -39,12 +43,51 @@ append config {
 		<binary name="} [nic_drv_binary] {"/>
 		<resource name="RAM" quantum="4M"/>
 		<provides> <service name="Nic"/> </provides>
-	</start>
+	</start>}
 
+append_if [use_dynamic_rom] config {
+	<start name="dynamic_rom">
+		<resource name="RAM" quantum="4M"/>
+		<provides><service name="ROM"/> </provides>
+		<config verbose="yes">
+			<rom name="socket_fs.config"> <inline description="MTU default">
+			<config ld_verbose="yes">
+				<vfs>
+					<dir name="socket">
+						<lxip ip_addr="10.0.2.55" netmask="255.255.255.0" gateway="10.0.2.1" nameserver="8.8.8.8"/>
+					</dir>
+				</vfs>
+				<default-policy root="/socket" writeable="yes" />
+			</config>
+			</inline>
+			<sleep milliseconds="3000"/> <inline description="MTU 400">
+			<config ld_verbose="yes">
+				<vfs>
+					<dir name="socket">
+						<lxip mtu="400" ip_addr="10.0.2.55" netmask="255.255.255.0" gateway="10.0.2.1" nameserver="8.8.8.8"/>
+					</dir>
+				</vfs>
+				<default-policy root="/socket" writeable="yes" />
+			</config>
+			</inline>
+			<sleep milliseconds="3000"/>
+			</rom>
+		</config>
+	</start>}
+
+append config {
 	<start name="socket_fs" caps="200">
 		<binary name="vfs"/>
 		<resource name="RAM" quantum="32M"/>
-		<provides> <service name="File_system"/> </provides>
+		<provides> <service name="File_system"/> </provides>}
+
+if {[use_dynamic_rom]} { append config {
+		<configfile name="socket_fs.config"/>
+		<route>
+			<service name="ROM" label="socket_fs.config"> <child name="dynamic_rom"/> </service>
+			<any-service> <parent/> <any-child/> </any-service>
+		</route>}
+} else { append config {
 		<config ld_verbose="yes">
 			<vfs>
 				<dir name="socket">
@@ -53,16 +96,20 @@ append config {
 				</dir>
 			</vfs>
 			<default-policy root="/socket" writeable="yes" />
-		</config>
+		</config>}
+}
+
+append config {
 	</start>
 }
 
 append boot_modules {
-	core init timer } [nic_drv_binary] { ram_fs vfs
+	core init timer } [nic_drv_binary] { vfs
-	ld.lib.so libc.lib.so libm.lib.so posix.lib.so
+	ld.lib.so libc.lib.so vfs_lxip.lib.so lxip.lib.so
-	vfs_lxip.lib.so lxip.lib.so
 }
 
+lappend_if [use_dynamic_rom] boot_modules dynamic_rom
+
 append_platform_drv_boot_modules
 
 append qemu_args " -nographic -net nic,model=e1000 -net tap,ifname=tap0,downscript=no,script=no "