bridging using libbridge

rewrite of guest, does not change cwd anymore
loading of created scenarios

8 files changed, 639 insertions, 143 deletions

diff --git a/src/dumm/Makefile b/src/dumm/Makefile
index 62aa92913..85bcad69f 100644
--- a/src/dumm/Makefile
+++ b/src/dumm/Makefile
@@ -1,3 +1,3 @@
 
-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 -O2 -Wall -Wno-format -Wno-strict-aliasing
+dumm:	dumm.c dumm.h guest.c guest.h iface.c iface.h bridge.c bridge.h mconsole.c mconsole.h main.c
+	gcc -o dumm dumm.c guest.c iface.c bridge.c mconsole.c main.c -lreadline -lbridge -lstrongswan -I../libstrongswan/ -g -O2 -Wall -Wno-format -Wno-strict-aliasing
diff --git a/src/dumm/bridge.c b/src/dumm/bridge.c
new file mode 100644
index 000000000..fa30ab6e9
--- /dev/null
+++ b/src/dumm/bridge.c
@@ -0,0 +1,160 @@
+/*
+ * 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/types.h>
+#include <libbridge.h>
+
+#include <debug.h>
+#include <utils/linked_list.h>
+
+#include "bridge.h"
+
+typedef struct private_bridge_t private_bridge_t;
+
+struct private_bridge_t {
+	/** public interface */
+	bridge_t public;
+	/** device name */
+	char *name;
+	/** list of attached interfaces */
+	linked_list_t *ifaces;
+};
+	
+/**
+ * Implementation of bridge_t.get_name.
+ */
+static char* get_name(private_bridge_t *this)
+{
+	return this->name;
+}
+
+/**
+ * Implementation of bridge_t.create_iface_iterator.
+ */
+static iterator_t* create_iface_iterator(private_bridge_t *this)
+{
+	return this->ifaces->create_iterator(this->ifaces, TRUE);
+}
+
+/**
+ * Implementation of bridge_t.del_iface.
+ */
+static bool del_iface(private_bridge_t *this, iface_t *iface)
+{
+	iterator_t *iterator;
+	iface_t *current;
+	bool good = FALSE;
+
+	iterator = this->ifaces->create_iterator(this->ifaces, TRUE);
+	while (iterator->iterate(iterator, (void**)&current))
+	{
+		if (current == iface)
+		{
+			if (br_del_interface(this->name, iface->get_hostif(iface)) != 0)
+			{
+				DBG1("removing iface '%s' from bridge '%s' in kernel failed: %m",
+					 iface->get_hostif(iface), this->name);
+			}
+			else
+			{
+				good = TRUE;
+			}
+			break;
+		}
+	}
+	if (iface != current)
+	{
+		DBG1("iface '%s' not found on bridge '%s'", iface->get_hostif(iface),
+			 this->name);
+	}
+	iterator->destroy(iterator);
+	return good;
+}
+
+/**
+ * Implementation of bridge_t.add_iface.
+ */
+static bool add_iface(private_bridge_t *this, iface_t *iface)
+{
+	if (br_add_interface(this->name, iface->get_hostif(iface)) != 0)
+	{
+		DBG1("adding iface '%s' to bridge '%s' failed: %m",
+			 iface->get_hostif(iface), this->name);
+		return FALSE;
+	}
+	this->ifaces->insert_last(this->ifaces, iface);
+	return TRUE;
+}
+
+/**
+ * instance counter to (de-)initialize libbridge
+ */
+static int instances = 0;
+
+/**
+ * Implementation of bridge_t.destroy.
+ */
+static void destroy(private_bridge_t *this)
+{
+	this->ifaces->destroy(this->ifaces);
+	if (br_del_bridge(this->name) != 0)
+	{
+		DBG1("deleting bridge '%s' from kernel failed: %m", this->name);
+	}
+	free(this->name);
+	free(this);
+	if (--instances == 0)
+	{
+		br_shutdown();
+	}
+}
+
+/**
+ * create the bridge instance
+ */
+bridge_t *bridge_create(char *name)
+{
+	private_bridge_t *this;
+	
+	if (instances == 0)
+	{
+		if (br_init() != 0)
+		{
+			DBG1("libbridge initialization failed: %m");
+			return NULL;
+		}
+	}
+	
+	this = malloc_thing(private_bridge_t);
+	this->public.get_name = (char*(*)(bridge_t*))get_name;
+	this->public.create_iface_iterator = (iterator_t*(*)(bridge_t*))create_iface_iterator;
+	this->public.del_iface = (bool(*)(bridge_t*, iface_t *iface))del_iface;
+	this->public.add_iface = (bool(*)(bridge_t*, iface_t *iface))add_iface;
+	this->public.destroy = (void*)destroy;
+
+	if (br_add_bridge(name) != 0)
+	{
+		DBG1("creating bridge '%s' failed: %m", name);
+		free(this);
+		return NULL;
+	}
+
+	this->name = strdup(name);
+	this->ifaces = linked_list_create();
+
+	instances++;
+	return &this->public;
+}
+
diff --git a/src/dumm/bridge.h b/src/dumm/bridge.h
new file mode 100644
index 000000000..d47f7ee54
--- /dev/null
+++ b/src/dumm/bridge.h
@@ -0,0 +1,76 @@
+/*
+ * 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 BRIDGE_H
+#define BRIDGE_H
+
+#include <library.h>
+#include <utils/iterator.h>
+
+#include "iface.h"
+
+typedef struct bridge_t bridge_t;
+
+/**
+ * @brief Interface in a guest, connected to a tap device on the host.
+ */
+struct bridge_t {
+	
+	/**
+	 * @brief Get the name of the bridge.
+	 *
+	 * @return				name of the bridge
+	 */
+	char* (*get_name)(bridge_t *this);
+	
+	/**
+	 * @brief Add an interface to a bridge.
+	 *
+	 * @param iface			interface to add
+	 * @return				TRUE if interface added
+	 */
+	bool (*add_iface)(bridge_t *this, iface_t *iface);
+	
+	/**
+	 * @brief Remove an interface from a bridge.
+	 *
+	 * @param iface			interface to remove
+	 * @return				TRUE ifinterface removed
+	 */
+	bool (*del_iface)(bridge_t *this, iface_t *iface);
+	
+	/**
+	 * @brief Create an iterator over all interfaces.
+	 *
+	 * @return 				iterator over iface_t's
+	 */
+	iterator_t* (*create_iface_iterator)(bridge_t *this);	
+	
+	/**
+	 * @brief Destroy a bridge
+	 */
+	void (*destroy) (bridge_t *this);
+};
+
+/**
+ * @brief Create a new bridge.
+ *
+ * @param name		name of the bridge to create
+ * @return			bridge, NULL if failed
+ */
+bridge_t *bridge_create(char *name);
+
+#endif /* BRIDGE_H */
+
diff --git a/src/dumm/dumm.c b/src/dumm/dumm.c
index 6432e74a7..b8211ff9e 100644
--- a/src/dumm/dumm.c
+++ b/src/dumm/dumm.c
@@ -13,7 +13,12 @@
  * for more details.
  */
 
-#include <sys/stat.h>
+#define _GNU_SOURCE
+
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <dirent.h>
 
 #include <debug.h>
 
@@ -22,16 +27,27 @@
 typedef struct private_dumm_t private_dumm_t;
 
 struct private_dumm_t {
+	/** public dumm interface */
 	dumm_t public;
+	/** working dir */
+	char *dir;
+	/** list of managed guests */
 	linked_list_t *guests;
+	/** list of managed bridges */
+	linked_list_t *bridges;
+	/** do not catch signals if we are destroying */
 	bool destroying;
 };
 
-static guest_t* create_guest(private_dumm_t *this, char *name, char *master, int mem)
+/**
+ * Implementation of dumm_t.create_guest.
+ */
+static guest_t* create_guest(private_dumm_t *this, char *name, char *kernel, 
+							 char *master, int mem)
 {
 	guest_t *guest;
 	
-	guest = guest_create(name, master, mem);
+	guest = guest_create(this->dir, name, kernel, master, mem);
 	if (guest)
 	{
 		this->guests->insert_last(this->guests, guest);
@@ -39,11 +55,37 @@ static guest_t* create_guest(private_dumm_t *this, char *name, char *master, int
 	return guest;
 }
 
+/**
+ * Implementation of dumm_t.create_guest_iterator.
+ */
 static iterator_t* create_guest_iterator(private_dumm_t *this)
 {
 	return this->guests->create_iterator(this->guests, TRUE);
-}	
+}
+
+/**
+ * Implementation of dumm_t.create_bridge.
+ */
+static bridge_t* create_bridge(private_dumm_t *this, char *name)
+{
+	bridge_t *bridge;
 	
+	bridge = bridge_create(name);
+	if (bridge)
+	{
+		this->bridges->insert_last(this->bridges, bridge);
+	}
+	return bridge;
+}
+
+/**
+ * Implementation of dumm_t.create_bridge_iterator.
+ */
+static iterator_t* create_bridge_iterator(private_dumm_t *this)
+{
+	return this->bridges->create_iterator(this->bridges, TRUE);
+}
+
 /**
  * Implementation of dumm_t.sigchild_handler.
  */
@@ -53,13 +95,11 @@ static void sigchild_handler(private_dumm_t *this, siginfo_t *info)
 	{
 		return;
 	}
-
 	switch (info->si_code)
 	{
 		case CLD_EXITED:
 		case CLD_KILLED:
 		case CLD_DUMPED:
-		case CLD_STOPPED:
 		{
 			iterator_t *iterator;
 			guest_t *guest;
@@ -81,11 +121,16 @@ static void sigchild_handler(private_dumm_t *this, siginfo_t *info)
 	}
 }
 
+/**
+ * Implementation of dumm_t.destroy
+ */
 static void destroy(private_dumm_t *this)
 {
 	iterator_t *iterator;
 	guest_t *guest;
 
+	this->bridges->destroy_offset(this->bridges, offsetof(bridge_t, destroy));
+	
 	iterator = this->guests->create_iterator(this->guests, TRUE);
 	while (iterator->iterate(iterator, (void**)&guest))
 	{
@@ -95,40 +140,72 @@ static void destroy(private_dumm_t *this)
 	
 	this->destroying = TRUE;
 	this->guests->destroy_offset(this->guests, offsetof(guest_t, destroy));
+	free(this->dir);
 	free(this);
 }
 
 /**
- * check for a directory, create if it does not exist
+ * load all guests in our working dir
  */
-static bool makedir(char *dir)
+static void load_guests(private_dumm_t *this)
 {
-	struct stat st;
+	DIR *dir;
+	struct dirent *ent;
+	guest_t *guest;
 	
-	if (stat(dir, &st) != 0)
+	dir = opendir(this->dir);
+	if (dir == NULL)
 	{
-		return mkdir(dir, S_IRWXU) == 0;
+		return;
 	}
-	return S_ISDIR(st.st_mode);
+	
+	while ((ent = readdir(dir)))
+	{
+		if (streq(ent->d_name, ".") ||  streq(ent->d_name, ".."))
+		{
+			continue;
+		}
+		guest = guest_load(this->dir, ent->d_name);
+		if (guest)
+		{
+			this->guests->insert_last(this->guests, guest);
+		}
+		else
+		{
+			DBG1("loading guest in directory '%s' failed, skipped", ent->d_name);
+		}
+	}
+	closedir(dir);
 }
 
-dumm_t *dumm_create()
+/**
+ * create a dumm instance
+ */
+dumm_t *dumm_create(char *dir)
 {
+	char cwd[PATH_MAX];
 	private_dumm_t *this = malloc_thing(private_dumm_t);
 	
+	this->public.create_guest = (guest_t*(*)(dumm_t*,char*,char*,char*,int))create_guest;
+	this->public.create_guest_iterator = (iterator_t*(*)(dumm_t*))create_guest_iterator;
+	this->public.create_bridge = (bridge_t*(*)(dumm_t*, char *name))create_bridge;
+	this->public.create_bridge_iterator = (iterator_t*(*)(dumm_t*))create_bridge_iterator;
 	this->public.sigchild_handler = (void(*)(dumm_t*, siginfo_t *info))sigchild_handler;
-	this->public.create_guest = (void*)create_guest;
-	this->public.create_guest_iterator = (void*)create_guest_iterator;
-	this->public.destroy = (void*)destroy;
+	this->public.destroy = (void(*)(dumm_t*))destroy;
 	
-	if (!makedir(HOST_DIR) || !makedir(MOUNT_DIR) || !makedir(RUN_DIR))
+	this->destroying = FALSE;
+	if (*dir == '/' || getcwd(cwd, sizeof(cwd)) == 0)
 	{
-		free(this);
-		return NULL;
+		this->dir = strdup(dir);
+	}
+	else
+	{
+		asprintf(&this->dir, "%s/%s", cwd, dir);
 	}
-	
-	this->destroying = FALSE;
 	this->guests = linked_list_create();
+	this->bridges = linked_list_create();
+	
+	load_guests(this);
 	return &this->public;
 }
 
diff --git a/src/dumm/dumm.h b/src/dumm/dumm.h
index fe4f9ca4e..cb68fdb1e 100644
--- a/src/dumm/dumm.h
+++ b/src/dumm/dumm.h
@@ -22,11 +22,7 @@
 #include <utils/linked_list.h>
 
 #include "guest.h"
-
-#define HOST_DIR "host"
-#define MOUNT_DIR "mount"
-#define RUN_DIR "run"
-
+#include "bridge.h"
 
 typedef struct dumm_t dumm_t;
 
@@ -41,11 +37,13 @@ struct dumm_t {
 	 * @brief Starts a new UML guest
 	 *
 	 * @param name		name of the guest
+	 * @param kernel	UML kernel to use for guest
 	 * @param master	mounted read only master filesystem
 	 * @param mem		amount of memory for guest, in MB
 	 * @return			guest if started, NULL if failed
 	 */
-	guest_t* (*create_guest) (dumm_t *this, char *name, char *master, int mem);
+	guest_t* (*create_guest) (dumm_t *this, char *name, char *kernel, 
+							  char *master, int mem);
 	
 	/**
 	 * @brief Create an iterator over all guests.
@@ -55,6 +53,21 @@ struct dumm_t {
 	iterator_t* (*create_guest_iterator) (dumm_t *this);
 	
 	/**
+	 * @brief Create a new bridge.
+	 *
+	 * @param name		name of the bridge to create
+	 * @return			created bridge
+	 */
+	bridge_t* (*create_bridge)(dumm_t *this, char *name);
+	
+	/**
+	 * @brief Create an iterator over all bridges.
+	 *
+	 * @return			iterator over bridge_t's
+	 */
+	iterator_t* (*create_bridge_iterator)(dumm_t *this);
+	
+	/**
 	 * @brief Handler for received SIG_CHILD signals.
 	 *
 	 * Dumm spans children, UML kernels. To track and cleanup these kernel
@@ -73,13 +86,12 @@ struct dumm_t {
 };
 
 /**
- * @brief Create a new group of UML hosts and networks.
- *
- * Dumm uses its working dir to create folders and files it works with.
+ * @brief Create a group of UML hosts and networks.
  *
+ * @param dir			directory to create guests/load from
  * @return				created UML group, or NULL if failed.
  */
-dumm_t *dumm_create();
+dumm_t *dumm_create(char *dir);
 
 #endif /* DUMM_H */
 
diff --git a/src/dumm/guest.c b/src/dumm/guest.c
index 784891835..533599bf5 100644
--- a/src/dumm/guest.c
+++ b/src/dumm/guest.c
@@ -17,12 +17,13 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/uio.h>
 #include <unistd.h>
 #include <stdio.h>
-#include <sys/uio.h>
-#include <sys/types.h>
 #include <fcntl.h>
 #include <signal.h>
+#include <dirent.h>
 
 #include <debug.h>
 #include <utils/linked_list.h>
@@ -31,6 +32,9 @@
 #include "guest.h"
 #include "mconsole.h"
 
+#define PERME (S_IRWXU | S_IRWXG)
+#define PERM (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP)
+
 typedef struct private_guest_t private_guest_t;
 
 struct private_guest_t {
@@ -38,8 +42,10 @@ struct private_guest_t {
 	guest_t public;
 	/** name of the guest */
 	char *name;
-	/** read only master filesystem guest uses */
-	char *master;
+	/** directory of guest */
+	int dir;
+	/** directory name of guest */
+	char *dirname;
 	/** amount of memory for guest, in MB */
 	int mem;
 	/** pid of guest child process */
@@ -48,6 +54,8 @@ struct private_guest_t {
 	guest_state_t state;
 	/** log file for console 0 */
 	int bootlog;
+	/** has the unionfs been mounted */
+	bool mounted;
 	/** mconsole to control running UML */
 	mconsole_t *mconsole;
 	/** list of interfaces attached to the guest */
@@ -151,12 +159,29 @@ static char* write_arg(char **pos, size_t *left, char *format, ...)
 }
 
 /**
+ * Implementation of guest_t.stop.
+ */
+static void stop(private_guest_t *this)
+{
+	if (this->state != GUEST_STOPPED)
+	{
+		this->state = GUEST_STOPPING;
+		this->ifaces->destroy_offset(this->ifaces, offsetof(iface_t, destroy));
+		this->ifaces = linked_list_create();
+		kill(this->pid, SIGINT);
+		while (this->state == GUEST_STOPPING)
+		{
+			sched_yield();
+		}
+	}
+}
+
+/**
  * Implementation of guest_t.start.
  */
 static bool start(private_guest_t *this, char *kernel)
 {
-	char buf[1024];
-	char cwd[512];
+	char buf[2048];
 	char *notify;
 	char *pos = buf;
 	char *args[16];
@@ -170,14 +195,13 @@ static bool start(private_guest_t *this, char *kernel)
 	}
 	this->state = GUEST_STARTING;
 	
-	notify = write_arg(&pos, &left, "%s/%s/notify", RUN_DIR, this->name);
+	notify = write_arg(&pos, &left, "%s/%s", this->dirname, NOTIFY_FILE);
 	
-	args[i++] = kernel;
+	args[i++] = write_arg(&pos, &left, "%s/%s", this->dirname, KERNEL_FILE);
 	args[i++] = write_arg(&pos, &left, "root=/dev/root");
 	args[i++] = write_arg(&pos, &left, "rootfstype=hostfs");
-	args[i++] = write_arg(&pos, &left, "rootflags=%s/%s/%s",
-						  getcwd(cwd, sizeof(cwd)), MOUNT_DIR, this->name);
-	args[i++] = write_arg(&pos, &left, "uml_dir=%s/%s", RUN_DIR, this->name);
+	args[i++] = write_arg(&pos, &left, "rootflags=%s/%s", this->dirname, UNION_DIR);
+	args[i++] = write_arg(&pos, &left, "uml_dir=%s", this->dirname);
 	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, "mconsole=notify:%s", notify);
@@ -199,10 +223,10 @@ static bool start(private_guest_t *this, char *kernel)
 			dup2(open("/dev/null", 0), 1);
 			dup2(open("/dev/null", 0), 2);
 			execvp(args[0], args);
-			DBG1("starting UML kernel '%s' failed", args[0]);
+			DBG1("starting UML kernel '%s' failed: %m", args[0]);
 			exit(1);
 		case -1:
-			this->pid = 0;
+			this->state = GUEST_STOPPED;
 			return FALSE;
 		default:
 			break;
@@ -212,8 +236,7 @@ static bool start(private_guest_t *this, char *kernel)
 	if (this->mconsole == NULL)
 	{
 		DBG1("opening mconsole at '%s' failed, stopping guest", buf);
-		kill(this->pid, SIGINT);
-		this->pid = 0;
+		stop(this);
 		return FALSE;
 	}
 	this->state = GUEST_RUNNING;
@@ -221,72 +244,34 @@ static bool start(private_guest_t *this, char *kernel)
 }
 
 /**
- * Implementation of guest_t.stop.
- */
-static void stop(private_guest_t *this)
-{
-	if (this->state != GUEST_STOPPED)
-	{
-		this->state = GUEST_STOPPING;
-		this->ifaces->destroy_offset(this->ifaces, offsetof(iface_t, destroy));
-		this->ifaces = linked_list_create();
-		kill(this->pid, SIGINT);
-		while (this->state == GUEST_STOPPING)
-		{
-			sched_yield();
-		}
-	}
-}
-
-/**
  * Implementation of guest_t.sigchild.
  */
 static void sigchild(private_guest_t *this)
 {
+	waitpid(this->pid, NULL, WNOHANG);
 	DESTROY_IF(this->mconsole);
 	this->mconsole = NULL;
 	this->state = GUEST_STOPPED;
-	this->pid = 0;
-}
-
-/**
- * Check if directory exists, create otherwise
- */
-static bool makedir(char *dir, char *name)
-{
-	struct stat st;
-	char buf[256];
-	size_t len;
-	
-	len = snprintf(buf, sizeof(buf), "%s/%s", dir, name);
-	if (len < 0 || len >= sizeof(buf))
-	{
-		return FALSE;
-	}
-	if (stat(buf, &st) != 0)
-	{
-		return mkdir(buf, S_IRWXU) == 0;
-	}
-	return S_ISDIR(st.st_mode);
 }
 
 /**
  * umount the union filesystem
  */
-static bool umount_unionfs(char *name)
+static bool umount_unionfs(private_guest_t *this)
 {
 	char cmd[128];
 	size_t len;
 	
-	len = snprintf(cmd, sizeof(cmd), "fusermount -u %s/%s", MOUNT_DIR, name);
-	if (len < 0 || len >= sizeof(cmd))
-	{
-		return FALSE;
-	}
-	if (system(cmd) != 0)
+	if (this->mounted)
 	{
-		DBG1("unmounting guest unionfs for %s failed", name);
-		return FALSE;
+		len = snprintf(cmd, sizeof(cmd), "fusermount -u %s/%s",
+					   this->dirname, UNION_DIR);
+		if (len < 0 || len >= sizeof(cmd) || system(cmd) != 0)
+		{
+			DBG1("unmounting guest unionfs failed");
+			return FALSE;
+		}
+		this->mounted = FALSE;
 	}
 	return TRUE;
 }
@@ -294,21 +279,22 @@ static bool umount_unionfs(char *name)
 /**
  * mount the union filesystem
  */
-static bool mount_unionfs(char *name, char *master)
+static bool mount_unionfs(private_guest_t *this)
 {
 	char cmd[256];
 	size_t len;
 	
-	len = snprintf(cmd, sizeof(cmd), "unionfs %s/%s:%s %s/%s",
-				   HOST_DIR, name, master, MOUNT_DIR, name);
-	if (len < 0 || len >= sizeof(cmd))
+	if (!this->mounted)
 	{
-		return FALSE;
-	}
-	if (system(cmd) != 0)
-	{
-		DBG1("mounting guest unionfs for %s using '%s' failed", name, cmd);
-		return FALSE;
+		len = snprintf(cmd, sizeof(cmd), "unionfs %s/%s:%s/%s %s/%s",
+					   this->dirname, MASTER_DIR, this->dirname, DIFF_DIR,
+					   this->dirname, UNION_DIR);
+		if (len < 0 || len >= sizeof(cmd) || system(cmd) != 0)
+		{
+			DBG1("mounting guest unionfs failed");
+			return FALSE;
+		}
+		this->mounted = TRUE;
 	}
 	return TRUE;
 }
@@ -316,43 +302,87 @@ static bool mount_unionfs(char *name, char *master)
 /**
  * open logfile for boot messages
  */
-static int open_bootlog(char *name)
+static int open_bootlog(private_guest_t *this)
 {
-	char blg[256];
-	size_t len;
 	int fd;
 	
-	len = snprintf(blg, sizeof(blg), "%s/%s/boot.log", RUN_DIR, name);
-	if (len < 0 || len >= sizeof(blg))
-	{
-		return 1;
-	}
-	fd = open(blg, O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR);
+	fd = openat(this->dir, LOG_FILE, O_WRONLY | O_CREAT, PERM);
 	if (fd == -1)
 	{
-		DBG1("opening bootlog '%s' for %s failed, using stdout", blg, name);
+		DBG1("opening bootlog failed, using stdout");
 		return 1;
 	}
 	return fd;
 }
 
 /**
+ * load memory configuration from file
+ */
+int loadmem(private_guest_t *this)
+{
+	FILE *file;
+	int mem = 0;
+	
+	file = fdopen(openat(this->dir, MEMORY_FILE, O_RDONLY, PERM), "r");
+	if (file)
+	{
+		if (fscanf(file, "%d", &mem) <= 0)
+		{
+			mem = 0;
+		}
+		fclose(file);
+	}
+	return mem;
+}
+
+/**
+ * save memory configuration to file
+ */
+bool savemem(private_guest_t *this, int mem)
+{
+	FILE *file;
+	bool retval = FALSE;
+	
+	file = fdopen(openat(this->dir, MEMORY_FILE, O_RDWR | O_CREAT | O_TRUNC,
+						 PERM), "w");
+	if (file)
+	{
+		if (fprintf(file, "%d", mem) > 0)
+		{
+			retval = TRUE;
+		}
+		fclose(file);
+	}
+	return retval;
+}
+
+/**
  * Implementation of guest_t.destroy.
  */
 static void destroy(private_guest_t *this)
 {
 	stop(this);
-	umount_unionfs(this->name);
+	umount_unionfs(this);
+	if (this->bootlog > 1)
+	{
+		close(this->bootlog);
+	}
+	if (this->dir > 0)
+	{
+		close(this->dir);
+	}
+	free(this->dirname);
 	free(this->name);
-	free(this->master);
 	free(this);
 }
 
 /**
- * create the guest instance, including required dirs and mounts 
+ * generic guest constructor
  */
-guest_t *guest_create(char *name, char *master, int mem)
+static private_guest_t *guest_create_generic(char *parent, char *name,
+											 bool create)
 {
+	char cwd[PATH_MAX];
 	private_guest_t *this = malloc_thing(private_guest_t);
 	
 	this->public.get_name = (void*)get_name;
@@ -365,22 +395,130 @@ guest_t *guest_create(char *name, char *master, int mem)
 	this->public.sigchild = (void(*)(guest_t*))sigchild;
 	this->public.destroy = (void*)destroy;
 	
-	if (!makedir(HOST_DIR, name) || !makedir(MOUNT_DIR, name) ||
-		!makedir(RUN_DIR, name) || !mount_unionfs(name, master))
+	if (*parent == '/' || getcwd(cwd, sizeof(cwd)) == NULL)
+	{
+		asprintf(&this->dirname, "%s/%s", parent, name);
+	}
+	else
+	{
+		asprintf(&this->dirname, "%s/%s/%s", cwd, parent, name);
+	}
+	if (create)
+	{
+		mkdir(this->dirname, PERME);
+	}
+	this->dir = open(this->dirname, O_DIRECTORY, PERME);
+	if (this->dir < 0)
 	{
+		DBG1("opening guest directory '%s' failed: %m", this->dirname);
+		free(this->dirname);
 		free(this);
 		return NULL;
 	}
 	
-	this->name = strdup(name);
-	this->master = strdup(master);
-	this->mem = mem;
 	this->pid = 0;
 	this->state = GUEST_STOPPED;
-	this->bootlog = open_bootlog(name);
 	this->mconsole = NULL;
 	this->ifaces = linked_list_create();
+	this->mem = 0;
+	this->bootlog = open_bootlog(this);
+	this->name = strdup(name);
+	this->mounted = FALSE;
+	
+	return this;
+}
+
+/**
+ * create a symlink to old called new in our working dir
+ */
+static bool make_symlink(private_guest_t *this, char *old, char *new)
+{
+	char cwd[PATH_MAX];
+	char buf[PATH_MAX];
+	
+	if (*old == '/' || getcwd(cwd, sizeof(cwd)) == NULL)
+	{
+		snprintf(buf, sizeof(buf), "%s", old);
+	}
+	else
+	{
+		snprintf(buf, sizeof(buf), "%s/%s", cwd, old);
+	}
+	return symlinkat(buf, this->dir, new) == 0;
+}
+
+
+/**
+ * create the guest instance, including required dirs and mounts 
+ */
+guest_t *guest_create(char *parent, char *name, char *kernel,
+					  char *master, int mem)
+{
+	private_guest_t *this = guest_create_generic(parent, name, TRUE);
+	
+	if (this == NULL)
+	{
+		return NULL;
+	}
+	
+	if (!make_symlink(this, master, MASTER_DIR) ||
+		!make_symlink(this, kernel, KERNEL_FILE))
+	{
+		DBG1("creating master/kernel symlink failed: %m");
+		destroy(this);
+		return NULL;
+	}
+	
+	if (mkdirat(this->dir, UNION_DIR, PERME) != 0 || 
+		mkdirat(this->dir, DIFF_DIR, PERME) != 0)
+	{
+		DBG1("unable to create directories for '%s': %m", name);
+		destroy(this);
+		return NULL;
+	}
+	
+	this->mem = mem;
+	if (!savemem(this, mem))
+	{
+		destroy(this);
+		return NULL;
+	}
+	
+	if (!mount_unionfs(this))
+	{
+		destroy(this);
+		return NULL;
+	}
 
 	return &this->public;
 }
 
+/**
+ * load an already created guest
+ */
+guest_t *guest_load(char *parent, char *name)
+{
+	private_guest_t *this = guest_create_generic(parent, name, FALSE);
+	
+	if (this == NULL)
+	{
+		return NULL;
+	}
+	
+	this->mem = loadmem(this);
+	if (this->mem == 0)
+	{
+		DBG1("unable to open memory configuration file: %m", name);
+		destroy(this);
+		return NULL;
+	}
+	
+	if (!mount_unionfs(this))
+	{
+		destroy(this);
+		return NULL;
+	}
+	
+	return &this->public;
+}
+
diff --git a/src/dumm/guest.h b/src/dumm/guest.h
index 48cfbf240..d9845e8a8 100644
--- a/src/dumm/guest.h
+++ b/src/dumm/guest.h
@@ -21,6 +21,14 @@
 
 #include "iface.h"
 
+#define MASTER_DIR "master"
+#define DIFF_DIR "diff"
+#define UNION_DIR "union"
+#define MEMORY_FILE "mem"
+#define KERNEL_FILE "linux"
+#define LOG_FILE "boot.log"
+#define NOTIFY_FILE "notify"
+
 typedef enum guest_state_t guest_state_t;
 
 /**
@@ -115,11 +123,22 @@ struct guest_t {
 /**
  * @brief Create a new, unstarted guest.
  *
- * @param name		name of the guest
+ * @param parent	parent directory to create the guest in
+ * @param name		name of the guest to create
+ * @param kernel	kernel this guest uses
  * @param master	read-only master filesystem for guest
  * @param mem		amount of memory to give the guest
  */
-guest_t *guest_create(char *name, char *master, int mem);
+guest_t *guest_create(char *parent, char *name, char *kernel,
+					  char *master, int mem);
+
+/**
+ * @brief Load a guest created with guest_create().
+ *
+ * @param parent	parent directory to look for a guest
+ * @param name		name of the guest directory
+ */
+guest_t *guest_load(char *parent, char *name);
 
 #endif /* GUEST_H */
 
diff --git a/src/dumm/main.c b/src/dumm/main.c
index 8d4c3e688..bd764017a 100644
--- a/src/dumm/main.c
+++ b/src/dumm/main.c
@@ -292,6 +292,16 @@ static void guest(char *name)
 	}
 }
 
+
+/**
+ * create an bridge
+ */
+static void create_bridge(char *name)
+{
+	dumm->create_bridge(dumm, name);
+
+}
+
 /**
  * create an UML guest
  */
@@ -299,11 +309,13 @@ static void create_guest(char *line)
 {
 	enum {
 		NAME = 0,
+		KERNEL,
 		MASTER,
 		MEMORY,
 	};
 	char *const opts[] = {
 		[NAME] = "name",
+		[KERNEL] = "kernel",
 		[MASTER] = "master",
 		[MEMORY] = "memory",
 		NULL
@@ -311,7 +323,8 @@ static void create_guest(char *line)
 	char *value;
 	char *name = NULL;
 	char *master = NULL;
-	int mem = 0;
+	char *kernel = NULL;
+	int mem = 128;
 	
 	while (TRUE)
 	{
@@ -320,6 +333,9 @@ static void create_guest(char *line)
 			case NAME:
 				name = value;
 				continue;
+			case KERNEL:
+				kernel = value;
+				continue;
 			case MASTER:
 				master = value;
 				continue;
@@ -334,21 +350,17 @@ static void create_guest(char *line)
 		}
 		break;
 	}
-	if (name == NULL)
+	if (name == NULL || master == NULL || kernel == NULL)
 	{
-		printf("option 'name' is required.\n");
+		printf("too few arguments!\n");
 		help();
 		return;
 	}
-	if (master == NULL)
-	{
-		master = "master";
-	}
 	if (mem == 0)
 	{
 		mem = 128;
 	}
-	if (dumm->create_guest(dumm, name, master, mem))
+	if (dumm->create_guest(dumm, name, kernel, master, mem))
 	{
 		printf("guest '%s' created\n", name);
 		guest(name);
@@ -406,6 +418,7 @@ int main(int argc, char *argv[])
 {
 	char *line = NULL;
 	struct sigaction action;
+	char *dir = ".";
 
 	while (TRUE)
 	{
@@ -420,11 +433,7 @@ int main(int argc, char *argv[])
 			case -1:
 				break;
 			case 'd':
-				if (chdir(optarg))
-				{
-					printf("changing to directory '%s' failed.\n", optarg);
-					return 1;
-				}
+				dir = optarg;
 				continue;
 			case 'h':
 				usage();
@@ -436,7 +445,7 @@ int main(int argc, char *argv[])
 		break;
 	}
 	
-	dumm = dumm_create();
+	dumm = dumm_create(dir);
 	
 	memset(&action, 0, sizeof(action));
 	action.sa_sigaction = signal_action;
@@ -456,6 +465,7 @@ int main(int argc, char *argv[])
 			QUIT = 0,
 			HELP,
 			CREATE,
+			BRIDGE,
 			LIST,
 			GUEST,
 		};
@@ -463,6 +473,7 @@ int main(int argc, char *argv[])
 			[QUIT] = "quit",
 			[HELP] = "help",
 			[CREATE] = "create",
+			[BRIDGE] = "bridge",
 			[LIST] = "list",
 			[GUEST] = "guest",
 			NULL
@@ -498,6 +509,9 @@ int main(int argc, char *argv[])
 			case CREATE:
 				create_guest(pos);
 				continue;
+			case BRIDGE:
+				create_bridge(pos);
+				continue;
 			case LIST:
 				list();
 				continue;