added dynamic interface manipulation for guests

management of tap devices on the host

10 files changed, 883 insertions, 35 deletions

diff --git a/src/dumm/Makefile b/src/dumm/Makefile
index 39bdb0b4a..c60e57dbc 100644
--- a/src/dumm/Makefile
+++ b/src/dumm/Makefile
@@ -1,3 +1,3 @@
 
-dumm:	dumm.c dumm.h guest.c guest.h main.c
-	gcc -o dumm dumm.c guest.c main.c -lreadline -lstrongswan -I../libstrongswan/ -g -Wall
+dumm:	dumm.c dumm.h guest.c guest.h iface.c iface.h mconsole.c mconsole.h main.c
+	gcc -o dumm dumm.c guest.c iface.c mconsole.c main.c -lreadline -lstrongswan -I../libstrongswan/ -g -Wall
diff --git a/src/dumm/dumm.c b/src/dumm/dumm.c
index 7536bce57..f5ca7d300 100644
--- a/src/dumm/dumm.c
+++ b/src/dumm/dumm.c
@@ -1,3 +1,18 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
 #include <sys/stat.h>
 
 #include <debug.h>
diff --git a/src/dumm/dumm.h b/src/dumm/dumm.h
index f18817abc..fd2ba46e8 100644
--- a/src/dumm/dumm.h
+++ b/src/dumm/dumm.h
@@ -1,3 +1,18 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
 #ifndef DUMM_H
 #define DUMM_H
 
@@ -45,6 +60,14 @@ struct dumm_t {
 	void (*destroy) (dumm_t *this);
 };
 
+/**
+ * @brief Create a new group of UML hosts and networks.
+ *
+ * Dumm uses its working dir to create folders and files it works with.
+ *
+ * @return				created UML group, or NULL if failed.
+ */
 dumm_t *dumm_create();
 
 #endif /* DUMM_H */
+
diff --git a/src/dumm/guest.c b/src/dumm/guest.c
index 202882367..cdb97c7bd 100644
--- a/src/dumm/guest.c
+++ b/src/dumm/guest.c
@@ -1,3 +1,18 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
 #define _GNU_SOURCE
 
 #include <sys/types.h>
@@ -10,27 +25,88 @@
 #include <signal.h>
 
 #include <debug.h>
+#include <utils/linked_list.h>
 
 #include "dumm.h"
 #include "guest.h"
+#include "mconsole.h"
 
 typedef struct private_guest_t private_guest_t;
 
 struct private_guest_t {
+	/** implemented public interface */
 	guest_t public;
+	/** name of the guest */
 	char *name;
+	/** kernel to boot for guest */
 	char *kernel;
+	/** read only master filesystem guest uses */
 	char *master;
+	/** amount of memory for guest, in MB */
 	int mem;
+	/** pid of guest child process */
 	int pid;
+	/** log file for console 0 */
 	int bootlog;
+	/** mconsole to control running UML */
+	mconsole_t *mconsole;
+	/** list of interfaces attached to the guest */
+	linked_list_t *ifaces;
 };
 
+/**
+ * Implementation of guest_t.get_name.
+ */
 static char* get_name(private_guest_t *this)
 {
 	return this->name;
 }
 
+/**
+ * Implementation of guest_t.create_iface.
+ */
+static iface_t* create_iface(private_guest_t *this, char *name)
+{
+	iterator_t *iterator;
+	iface_t *iface;
+	
+	if (this->pid == 0)
+	{
+		DBG1("guest '%s' not running, unable to add interface", this->name);
+		return NULL;
+	}
+	
+	iterator = this->ifaces->create_iterator(this->ifaces, TRUE);
+	while (iterator->iterate(iterator, (void**)&iface))
+	{
+		if (streq(name, iface->get_guest(iface)))
+		{
+			DBG1("guest '%s' already has an interface '%s'", this->name, name);
+			iterator->destroy(iterator);
+			return NULL;
+		}
+	}
+	iterator->destroy(iterator);
+
+	iface = iface_create(name, this->mconsole);
+	if (iface)
+	{
+		this->ifaces->insert_last(this->ifaces, iface);
+	}
+	return iface;
+}
+
+/**
+ * Implementation of guest_t.create_iface_iterator.
+ */
+static iterator_t* create_iface_iterator(private_guest_t *this)
+{
+	return this->ifaces->create_iterator(this->ifaces, TRUE);
+}
+
+/**
+ * write format string to a buffer, and advance buffer position
+ */
 static char* write_arg(char **pos, size_t *left, char *format, ...)
 {
 	size_t len;
@@ -50,6 +126,9 @@ static char* write_arg(char **pos, size_t *left, char *format, ...)
 	return res;
 }
 
+/**
+ * Implementation of guest_t.start.
+ */
 static bool start(private_guest_t *this)
 {
 	char buf[1024];
@@ -67,7 +146,7 @@ static bool start(private_guest_t *this)
 	args[i++] = write_arg(&pos, &left, "uml_dir=%s/%s", RUN_DIR, this->name);
 	args[i++] = write_arg(&pos, &left, "umid=%s", this->name);
 	args[i++] = write_arg(&pos, &left, "mem=%dM", this->mem);
-	//args[i++] = write_arg(&pos, &left, "con=pts");
+	/*args[i++] = write_arg(&pos, &left, "con=pts");*/
 	args[i++] = write_arg(&pos, &left, "con0=null,fd:%d", this->bootlog);
 	args[i++] = write_arg(&pos, &left, "con1=fd:0,fd:1");
 	args[i++] = write_arg(&pos, &left, "con3=null,null");
@@ -84,15 +163,30 @@ static bool start(private_guest_t *this)
 			dup2(open("/dev/null", 0), 1);
 			dup2(open("/dev/null", 0), 2);
 			execvp(args[0], args);
+			DBG1("starting UML kernel '%s' failed", args[0]);
 			exit(1);
 		case -1:
 			this->pid = 0;
 			return FALSE;
 		default:
-			return TRUE;
+			break;
+	}
+	/* open mconsole */
+	snprintf(buf, sizeof(buf), "%s/%s/%s/mconsole", RUN_DIR, this->name, this->name);
+	this->mconsole = mconsole_create(buf);
+	if (this->mconsole == NULL)
+	{
+		DBG1("opening mconsole at '%s' failed, stopping guest", buf);
+		kill(this->pid, SIGINT);
+		this->pid = 0;
+		return FALSE;
 	}
+	return TRUE;
 }
 
+/**
+ * Implementation of guest_t.stop.
+ */
 static void stop(private_guest_t *this)
 {
 	if (this->pid)
@@ -103,7 +197,7 @@ static void stop(private_guest_t *this)
 }
 
 /**
- * create a directory
+ * Check if directory exists, create otherwise
  */
 static bool makedir(char *dir, char *name)
 {
@@ -138,6 +232,7 @@ static bool umount_unionfs(char *name)
 	}
 	if (system(cmd) != 0)
 	{
+		DBG1("unmounting guest unionfs for %s failed", name);
 		return FALSE;
 	}
 	return TRUE;
@@ -151,7 +246,6 @@ static bool mount_unionfs(char *name, char *master)
 	char cmd[256];
 	size_t len;
 	
-	/* mount unionfs */
 	len = snprintf(cmd, sizeof(cmd), "unionfs %s/%s:%s %s/%s",
 				   HOST_DIR, name, master, MOUNT_DIR, name);
 	if (len < 0 || len >= sizeof(cmd))
@@ -160,7 +254,7 @@ static bool mount_unionfs(char *name, char *master)
 	}
 	if (system(cmd) != 0)
 	{
-		DBG1("mounting unionfs using '%s' failed.", cmd);
+		DBG1("mounting guest unionfs for %s using '%s' failed", name, cmd);
 		return FALSE;
 	}
 	return TRUE;
@@ -183,18 +277,21 @@ static int open_bootlog(char *name)
 	fd = open(blg, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
 	if (fd == -1)
 	{
+		DBG1("opening bootlog '%s' for %s failed, using stdout", blg, name);
 		return 1;
 	}
 	return fd;
 }
 
 /**
- * stop guest, unmount mounts
+ * Implementation of guest_t.destroy.
  */
 static void destroy(private_guest_t *this)
 {
 	stop(this);
 	umount_unionfs(this->name);
+	this->ifaces->destroy_offset(this->ifaces, offsetof(iface_t, destroy));
+	DESTROY_IF(this->mconsole);
 	free(this->name);
 	free(this->kernel);
 	free(this->master);
@@ -209,21 +306,15 @@ guest_t *guest_create(char *name, char *kernel, char *master, int mem)
 	private_guest_t *this = malloc_thing(private_guest_t);
 	
 	this->public.get_name = (void*)get_name;
+	this->public.create_iface = (iface_t*(*)(guest_t*,char*))create_iface;
+	this->public.create_iface_iterator = (iterator_t*(*)(guest_t*))create_iface_iterator;
 	this->public.start = (void*)start;
 	this->public.stop = (void*)stop;
 	this->public.destroy = (void*)destroy;
 	
 	if (!makedir(HOST_DIR, name) || !makedir(MOUNT_DIR, name) ||
-		!makedir(RUN_DIR, name))
-	{
-		DBG1("creating guest directories for %s failed failed.", name);
-		free(this);
-		return NULL;
-	}
-	
-	if (!mount_unionfs(name, master))
+		!makedir(RUN_DIR, name) || !mount_unionfs(name, master))
 	{
-		DBG1("mounting guest unionfs for %s failed.", name);
 		free(this);
 		return NULL;
 	}
@@ -234,6 +325,8 @@ guest_t *guest_create(char *name, char *kernel, char *master, int mem)
 	this->mem = mem;
 	this->pid = 0;
 	this->bootlog = open_bootlog(name);
+	this->mconsole = NULL;
+	this->ifaces = linked_list_create();
 
 	return &this->public;
 }
diff --git a/src/dumm/guest.h b/src/dumm/guest.h
index 39a72c081..f4e9f50c6 100644
--- a/src/dumm/guest.h
+++ b/src/dumm/guest.h
@@ -1,23 +1,84 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
 #ifndef GUEST_H
 #define GUEST_H
 
 #include <library.h>
-#include <utils/linked_list.h>
+#include <utils/iterator.h>
+
+#include "iface.h"
 
 typedef struct guest_t guest_t;
 
+/**
+ * @brief A guest is a UML instance running on the host.
+ **/
 struct guest_t {
 	
+	/**
+	 * @brief Get the name of this guest.
+	 *
+	 * @return		name of the guest
+	 */
 	char* (*get_name) (guest_t *this);
 	
+	/**
+	 * @brief Start the guest.
+	 *
+	 * @return		TRUE if guest successfully started
+	 */
 	bool (*start) (guest_t *this);
 	
+	/**
+	 * @brief Kill the guest.
+	 *
+	 * @return		TRUE if guest was running and killed
+	 */
 	bool (*stop) (guest_t *this);
 	
+	/**
+	 * @brief Create a new interface for that host.
+	 *
+	 * @param name	name of the interface in the guest
+	 * @return		created interface, or NULL if failed
+	 */
+	iface_t* (*create_iface)(guest_t *this, char *name);
+	
+	/**
+	 * @brief Create an iterator over all guest interfaces.
+	 *
+	 * @return		iterator over iface_t's
+	 */
+	iterator_t* (*create_iface_iterator)(guest_t *this);
+
+	/**
+	 * @brief Close and destroy a guest with all interfaces
+	 */	
 	void (*destroy) (guest_t *this);
 };
 
+/**
+ * @brief Create a new, unstarted guest.
+ *
+ * @param name		name of the guest
+ * @param kernel	kernel to boot for this guest
+ * @param master	read-only master filesystem for guest
+ * @param mem		amount of memory to give the guest
+ */
 guest_t *guest_create(char *name, char *kernel, char *master, int mem);
 
-
 #endif /* GUEST_H */
+
diff --git a/src/dumm/iface.c b/src/dumm/iface.c
new file mode 100644
index 000000000..9e690d488
--- /dev/null
+++ b/src/dumm/iface.c
@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ * Copyright (C) 2002 Jeff Dike
+ *
+ * Based on the "tunctl" utlity from Jeff Dike.
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include <sys/types.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <linux/if_tun.h>
+
+#include <debug.h>
+
+#include "iface.h"
+
+typedef struct private_iface_t private_iface_t;
+
+struct private_iface_t {
+	/** public interface */
+	iface_t public;
+	/** device name in guest (eth0) */
+	char *guest;
+	/** device name at host (tap0) */
+	char *host;
+	/** tap device handle to manage taps */
+	int tap;
+	/** mconsole for guest */
+	mconsole_t *mconsole;
+};
+
+/**
+ * Implementation of iface_t.get_guest.
+ */
+static char* get_guest(private_iface_t *this)
+{
+	return this->guest;
+}
+
+/**
+ * Implementation of iface_t.get_host.
+ */
+static char* get_host(private_iface_t *this)
+{
+	return this->host;
+}
+
+/**
+ * destroy the tap device
+ */
+static bool destroy_tap(private_iface_t *this)
+{
+	struct ifreq ifr;
+
+	memset(&ifr, 0, sizeof(ifr));
+	ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+	strncpy(ifr.ifr_name, this->host, sizeof(ifr.ifr_name) - 1);
+	
+	if (ioctl(this->tap, TUNSETIFF, &ifr) < 0 ||
+		ioctl(this->tap, TUNSETPERSIST, 0) < 0)
+	{
+		DBG1("removing %s failed: %m", this->host);
+		return FALSE;
+	}
+	return TRUE;
+}
+
+/**
+ * create the tap device
+ */
+static char* create_tap(private_iface_t *this)
+{
+	struct ifreq ifr;
+
+	memset(&ifr, 0, sizeof(ifr));
+	ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+	
+	if (ioctl(this->tap, TUNSETIFF, &ifr) < 0 ||
+		ioctl(this->tap, TUNSETPERSIST, 1) < 0)
+    {
+		DBG1("creating new tap device failed: %m");
+		return NULL;
+    } 
+	return strdup(ifr.ifr_name);
+}
+
+/**
+ * Implementation of iface_t.destroy.
+ */
+static void destroy(private_iface_t *this)
+{
+	this->mconsole->del_iface(this->mconsole, this->guest);
+	destroy_tap(this);
+	close(this->tap);
+	free(this->guest);
+	free(this->host);
+	free(this);
+}
+
+/**
+ * create the iface instance
+ */
+iface_t *iface_create(char *guest, mconsole_t *mconsole)
+{
+	private_iface_t *this = malloc_thing(private_iface_t);
+	
+	this->public.get_host = (char*(*)(iface_t*))get_host;
+	this->public.get_guest = (char*(*)(iface_t*))get_guest;
+	this->public.destroy = (void*)destroy;
+
+	this->mconsole = mconsole;
+	this->tap = open(TAP_DEVICE, O_RDWR);
+	if (this->tap < 0)
+	{
+		DBG1("unable to open tap device %s: %m", TAP_DEVICE);
+		free(this);
+		return NULL;
+	}
+	this->guest = strdup(guest);
+	this->host = create_tap(this);
+	if (this->host == NULL)
+	{
+		destroy_tap(this);
+		close(this->tap);
+		free(this->guest);
+		free(this);
+		return NULL;
+	}
+	if (!this->mconsole->add_iface(this->mconsole, this->guest, this->host))
+	{
+		DBG1("creating interface '%s' in guest failed", this->guest);
+		destroy_tap(this);
+		close(this->tap);
+		free(this->guest);
+		free(this->host);
+		free(this);
+		return NULL;
+	}
+	return &this->public;
+}
+
diff --git a/src/dumm/iface.h b/src/dumm/iface.h
new file mode 100644
index 000000000..de69fcbba
--- /dev/null
+++ b/src/dumm/iface.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#ifndef IFACE_H
+#define IFACE_H
+
+#include <library.h>
+#include <utils/iterator.h>
+
+#include "mconsole.h"
+
+#define TAP_DEVICE "/dev/net/tun"
+
+typedef struct iface_t iface_t;
+
+/**
+ * @brief Interface in a guest, connected to a tap device on the host.
+ */
+struct iface_t {
+	
+	/**
+	 * @brief Get the interface name in the guest (e.g. eth0).
+	 *
+	 * @return		guest interface name
+	 */
+	char* (*get_guest)(iface_t *this);
+	
+	/**
+	 * @brief Get the interface name at the host (e.g. tap0).
+	 *
+	 * @return		host interface (tap device) name
+	 */
+	char* (*get_host)(iface_t *this);
+	
+	/*
+	bool (*up) (iface_t *this);
+	bool (*down) (iface_t *this);
+	bool (*add_addr) (iface_t *this, host_t *addr);
+	bool (*del_addr) (iface_t *this, host_t *addr);
+	iterator_t* (*create_addr_iterator) (iface_t *this);
+	*/
+	
+	/**
+	 * @brief Destroy an interface
+	 */
+	void (*destroy) (iface_t *this);
+};
+
+/**
+ * @brief Create a new interface for a guest
+ *
+ * @param guest		name of the interface in the guest
+ * @param mconsole	mconsole of guest
+ * @return			interface descriptor, or NULL if failed
+ */
+iface_t *iface_create(char *guest, mconsole_t *mconsole);
+
+#endif /* IFACE_H */
diff --git a/src/dumm/main.c b/src/dumm/main.c
index 26896c2df..7e22ddfd6 100644
--- a/src/dumm/main.c
+++ b/src/dumm/main.c
@@ -1,3 +1,18 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
 #define _GNU_SOURCE
 
 #include <stdio.h>
@@ -20,7 +35,7 @@ static void usage()
 }
 
 /**
- * show usage information (commandline arguments)
+ * help for dumm root shell
  */
 static void help()
 {
@@ -29,15 +44,29 @@ static void help()
 	printf("                                kernel=<uml-kernel>\n");
 	printf("                                master=<read-only root files>\n");
 	printf("                                memory=<guest memory in MB>\n");
-	printf("guests                        list running guests\n");
+	printf("list                          list running guests\n");
+	printf("guest <name>                  open guest menu for <name>\n");
 	printf("help                          show this help\n");
 	printf("quit                          kill quests and exit\n");
 }
 
+
+/**
+ * help for guest shell
+ */
+static void help_guest()
+{
+	printf("addif <name>                  add an interface to the guest\n");
+	printf("delif <name>                  remove the interface\n");
+	printf("listif                        list guests interfaces\n");
+	printf("help                          show this help\n");
+	printf("quit                          quit the guest menu\n");
+}
+
 /**
  * start an UML guest
  */
-static void start(umli_t *umli, char *line)
+static void start(dumm_t *dumm, char *line)
 {
 	enum {
 		NAME = 0,
@@ -101,7 +130,7 @@ static void start(umli_t *umli, char *line)
 		mem = 128;
 	}
 	
-	if (umli->start_guest(umli, name, kernel, master, mem))
+	if (dumm->start_guest(dumm, name, kernel, master, mem))
 	{
 		printf("starting guest '%s'\n", name);
 	}
@@ -112,19 +141,187 @@ static void start(umli_t *umli, char *line)
 }
 
 /**
- * list running UML guests
+ * add an iface to a guest
+ */
+static void add_if(guest_t *guest, char *name)
+{
+	iface_t *iface;
+	
+	iface = guest->create_iface(guest, name);
+	if (iface)
+	{
+		printf("created guest interface '%s' connected to '%s'\n",
+			   iface->get_guest(iface), iface->get_host(iface));
+	}
+	else
+	{
+		printf("failed to create guest interface\n");
+	}
+}
+
+/**
+ * delete an iface from a guest
  */
-static void guests(umli_t *umli)
+static void del_if(guest_t *guest, char *name)
 {
+	iface_t *iface;
+	iterator_t *iterator;
+	bool found = FALSE;
+	
+	iterator = guest->create_iface_iterator(guest);
+	while (iterator->iterate(iterator, (void**)&iface))
+	{
+		if (streq(name, iface->get_guest(iface)))
+		{
+			iterator->remove(iterator);
+			printf("removing interface '%s' ('%s') from %s\n",
+				   iface->get_guest(iface), iface->get_host(iface),
+				   guest->get_name(guest));
+			iface->destroy(iface);
+			found = TRUE;
+			break;
+		}
+	}
+	iterator->destroy(iterator);
+	if (!found)
+	{
+		printf("guest '%s' has no interface named '%s'\n",
+			   guest->get_name(guest), name);
+	}
+}
+
+/**
+ * list interfaces on a guest
+ */
+static void list_if(guest_t *guest)
+{
+	iface_t *iface;
+	iterator_t *iterator;
+	
+	iterator = guest->create_iface_iterator(guest);
+	while (iterator->iterate(iterator, (void**)&iface))
+	{
+		printf("'%s' => '%s'\n", iface->get_guest(iface), iface->get_host(iface));
+
+	}
+	iterator->destroy(iterator);
+}
+
+/**
+ * subshell for guests
+ */
+static void guest(dumm_t *dumm, char *name)
+{
+	char *line = NULL;
+	char prompt[32];
+	int len;
 	iterator_t *iterator;
 	guest_t *guest;
+	bool found = FALSE;
 	
-	iterator = umli->create_guest_iterator(umli);
+	iterator = dumm->create_guest_iterator(dumm);
 	while (iterator->iterate(iterator, (void**)&guest))
 	{
-		printf("%s\n", guest->get_name(guest));
+		if (streq(name, guest->get_name(guest)))
+		{
+			found = TRUE;
+		}
 	}
 	iterator->destroy(iterator);
+	if (!found)
+	{
+		printf("guest '%s' not found\n", name);
+		return;
+	}
+	
+	len = snprintf(prompt, sizeof(prompt), "dumm@%s# ", name);
+	if (len < 0 || len >= sizeof(prompt))
+	{
+		return;
+	}
+
+	while (TRUE)
+	{
+		enum {
+			QUIT = 0,
+			HELP,
+			ADDIF,
+			DELIF,
+			LISTIF,
+		};
+		char *const opts[] = {
+			[QUIT] = "quit",
+			[HELP] = "help",
+			[ADDIF] = "addif",
+			[DELIF] = "delif",
+			[LISTIF] = "listif",
+			NULL
+		};
+		char *pos, *value;
+		
+		free(line);
+		line = readline(prompt);
+		if (line == NULL || *line == '\0')
+		{
+			continue;
+		}
+		add_history(line);
+		pos = line;
+		while (*pos != '\0')
+		{
+			if (*pos == ' ')
+			{
+				*pos = ',';
+			}
+			pos++;
+		}
+		pos = line;
+		switch (getsubopt(&pos, opts, &value))
+		{
+			case QUIT:
+				free(line);
+				break;
+			case HELP:
+				help_guest();
+				continue;
+			case ADDIF:
+				add_if(guest, pos);
+				continue;
+			case DELIF:
+				del_if(guest, pos);
+				continue;
+			case LISTIF:
+				list_if(guest);
+				continue;
+			default:
+				printf("command unknown: '%s'\n", line);
+				continue;
+		}
+		break;
+	}
+}
+
+/**
+ * list running UML guests
+ */
+static void list(dumm_t *dumm)
+{
+	iterator_t *guests, *ifaces;
+	guest_t *guest;
+	iface_t *iface;
+	
+	guests = dumm->create_guest_iterator(dumm);
+	while (guests->iterate(guests, (void**)&guest))
+	{
+		printf("%s\n", guest->get_name(guest));
+		ifaces = guest->create_iface_iterator(guest);
+		while (ifaces->iterate(ifaces, (void**)&iface))
+		{
+			printf("  '%s' => '%s'\n", iface->get_guest(iface), iface->get_host(iface));
+		}
+		ifaces->destroy(ifaces);
+	}
+	guests->destroy(guests);
 }
 
 /**
@@ -132,7 +329,7 @@ static void guests(umli_t *umli)
  */
 int main(int argc, char *argv[])
 {
-	umli_t *umli;
+	dumm_t *dumm;
 	char *line = NULL;
 
 	while (TRUE)
@@ -164,7 +361,7 @@ int main(int argc, char *argv[])
 		break;
 	}
 	
-	umli = umli_create();
+	dumm = dumm_create();
 
 	while (TRUE)
 	{
@@ -172,13 +369,15 @@ int main(int argc, char *argv[])
 			QUIT = 0,
 			HELP,
 			START,
-			GUESTS,
+			LIST,
+			GUEST,
 		};
 		char *const opts[] = {
 			[QUIT] = "quit",
 			[HELP] = "help",
 			[START] = "start",
-			[GUESTS] = "guests",
+			[LIST] = "list",
+			[GUEST] = "guest",
 			NULL
 		};
 		char *pos, *value;
@@ -210,10 +409,13 @@ int main(int argc, char *argv[])
 				help();
 				continue;
 			case START:
-				start(umli, pos);
+				start(dumm, pos);
+				continue;
+			case LIST:
+				list(dumm);
 				continue;
-			case GUESTS:
-				guests(umli);
+			case GUEST:
+				guest(dumm, pos);
 				continue;
 			default:
 				printf("command unknown: '%s'\n", line);
@@ -221,7 +423,7 @@ int main(int argc, char *argv[])
 		}
 		break;
 	}
-	umli->destroy(umli);
+	dumm->destroy(dumm);
 	clear_history();
 	return 0;
 }
diff --git a/src/dumm/mconsole.c b/src/dumm/mconsole.c
new file mode 100644
index 000000000..b782ebe81
--- /dev/null
+++ b/src/dumm/mconsole.c
@@ -0,0 +1,170 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ * Copyright (C) 2001-2004 Jeff Dike
+ *
+ * Based on the "uml_mconsole" utilty from Jeff Dike.
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <debug.h>
+
+#include "mconsole.h"
+
+#define MCONSOLE_MAGIC 0xcafebabe
+#define MCONSOLE_VERSION 2
+#define MCONSOLE_MAX_DATA 512
+
+typedef struct private_mconsole_t private_mconsole_t;
+
+struct private_mconsole_t {
+	/** public interface */
+	mconsole_t public;
+	/** mconsole socket */
+	int socket;
+	/** address of uml socket */
+	struct sockaddr_un uml;
+};
+
+/**
+ * send a request to UML using mconsole
+ */
+static bool request(private_mconsole_t *this, char *command)
+{
+	struct {
+		u_int32_t magic;
+		u_int32_t version;
+		u_int32_t len;
+		char data[MCONSOLE_MAX_DATA];
+	} request;
+	struct {
+		u_int32_t err;
+		u_int32_t more;
+		u_int32_t len;
+		char data[MCONSOLE_MAX_DATA];
+	} reply;
+	bool first = TRUE, good = TRUE;
+	int len;
+	
+	memset(&request, 0, sizeof(request));
+	request.magic = MCONSOLE_MAGIC;
+	request.version = MCONSOLE_VERSION;
+	request.len = min(strlen(command), sizeof(reply.data) - 1);
+	strncpy(request.data, command, request.len);
+
+	if (sendto(this->socket, &request, sizeof(request), 0,
+		(struct sockaddr*)&this->uml, sizeof(this->uml)) < 0)
+	{
+		DBG1("sending mconsole command to UML failed: %m");
+		return FALSE;
+	}
+	do 
+	{
+		len = recvfrom(this->socket, &reply, sizeof(reply), 0, NULL, 0);
+		if (len < 0)
+		{
+			DBG1("receiving from mconsole failed: %m");
+	    	return FALSE;
+		}
+		if (first && reply.err)
+		{
+			good = FALSE;
+			DBG1("received error from UML mconsole: %s", reply.data);
+		}
+		first = FALSE;
+	}
+	while (reply.more);
+	return good;
+}
+
+/**
+ * Implementation of mconsole_t.add_iface.
+ */
+static bool add_iface(private_mconsole_t *this, char *guest, char *host)
+{
+	char buf[128];
+	int len;
+	
+	len = snprintf(buf, sizeof(buf), "config %s=tuntap,%s", guest, host);
+	if (len < 0 || len >= sizeof(buf))
+	{
+		return FALSE;
+	}
+	return request(this, buf);
+}
+
+/**
+ * Implementation of mconsole_t.del_iface.
+ */
+static bool del_iface(private_mconsole_t *this, char *guest)
+{
+	char buf[128];
+	int len;
+	
+	len = snprintf(buf, sizeof(buf), "remove %s", guest);
+	if (len < 0 || len >= sizeof(buf))
+	{
+		return FALSE;
+	}
+	return request(this, buf);
+}
+
+/**
+ * Implementation of mconsole_t.destroy.
+ */
+static void destroy(private_mconsole_t *this)
+{
+	close(this->socket);
+	free(this);
+}
+
+/**
+ * create the mconsole instance
+ */
+mconsole_t *mconsole_create(char *sock)
+{
+	struct sockaddr_un addr;
+	private_mconsole_t *this = malloc_thing(private_mconsole_t);
+	
+	this->public.add_iface = (bool(*)(mconsole_t*, char *guest, char *host))add_iface;
+	this->public.del_iface = (bool(*)(mconsole_t*, char *guest))del_iface;
+	this->public.destroy = (void*)destroy;
+	
+	this->socket = socket(AF_UNIX, SOCK_DGRAM, 0);
+	if (this->socket < 0)
+	{
+		DBG1("opening mconsole socket failed: %m");
+		free(this);
+		return NULL;
+	}
+	memset(&addr, 0, sizeof(addr));
+	addr.sun_family = AF_UNIX;
+	sprintf(&addr.sun_path[1], "%5d", getpid());
+	if (bind(this->socket, (struct sockaddr*)&addr, sizeof(addr)) < 0)
+	{
+		DBG1("binding mconsole socket failed: %m");
+		destroy(this);
+		return NULL;
+	}
+	memset(&this->uml, 0, sizeof(this->uml));
+	this->uml.sun_family = AF_UNIX;
+	strncpy(this->uml.sun_path, sock, sizeof(this->uml.sun_path));
+	
+	return &this->public;
+}
+
diff --git a/src/dumm/mconsole.h b/src/dumm/mconsole.h
new file mode 100644
index 000000000..8d71053a5
--- /dev/null
+++ b/src/dumm/mconsole.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2007 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#ifndef MCONSOLE_H
+#define MCONSOLE_H
+
+#include <library.h>
+
+typedef struct mconsole_t mconsole_t;
+
+/**
+ * @brief UML mconsole, change running UML configuration using mconsole.
+ */
+struct mconsole_t {
+	
+	/**
+	 * @brief Create a guest interface and connect it to tap host interface.
+	 *
+	 * @param guest			name of the interface to create in the guest
+	 * @param host			name of the tap device to connect guest to
+	 * @return				TRUE if interface created
+	 */
+	bool (*add_iface)(mconsole_t *this, char *guest, char *host);
+	
+	/**
+	 * @brief Delete a guest interface.
+	 *
+	 * @param guest			name of the interface to delete on the guest
+	 * @return				TRUE if interface deleted
+	 */
+	bool (*del_iface)(mconsole_t *this, char *guest);
+	
+	/**
+	 * @brief Destroy the mconsole instance
+	 */
+	void (*destroy) (mconsole_t *this);
+};
+
+/**
+ * @brief Create a new mconsole connection to a guest.
+ *
+ * @param socket			guests mconsole socket
+ * @return					mconsole instance, or NULL if failed
+ */
+mconsole_t *mconsole_create(char *socket);
+
+#endif /* MCONSOLE_H */
+