support for killing guests properly

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 -Wall
+	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

src/dumm/dumm.c

@@ -41,6 +41,38 @@ static guest_t* create_guest(private_dumm_t *this, char *name, char *master, int
 static iterator_t* create_guest_iterator(private_dumm_t *this)
 {
 	return this->guests->create_iterator(this->guests, TRUE);
+}	
+	
+/**
+ * Implementation of dumm_t.sigchild_handler.
+ */
+static void sigchild_handler(private_dumm_t *this, siginfo_t *info)
+{
+	switch (info->si_code)
+	{
+		case CLD_EXITED:
+		case CLD_KILLED:
+		case CLD_DUMPED:
+		case CLD_STOPPED:
+		{
+			iterator_t *iterator;
+			guest_t *guest;
+			
+			iterator = this->guests->create_iterator(this->guests, TRUE);
+			while (iterator->iterate(iterator, (void**)&guest))
+			{
+				if (guest->get_pid(guest) == info->si_pid)
+				{
+					guest->sigchild(guest);
+					break;
+				}
+			}
+			iterator->destroy(iterator);
+			break;
+		}
+		default:
+			break;
+	}
 }
 
 static void destroy(private_dumm_t *this)
@@ -67,6 +99,7 @@ dumm_t *dumm_create()
 {
 	private_dumm_t *this = malloc_thing(private_dumm_t);
 	
+	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;

src/dumm/dumm.h

@@ -16,6 +16,8 @@
 #ifndef DUMM_H
 #define DUMM_H
 
+#include <signal.h>
+
 #include <library.h>
 #include <utils/linked_list.h>
 
@@ -52,6 +54,18 @@ struct dumm_t {
 	 */
 	iterator_t* (*create_guest_iterator) (dumm_t *this);
 	
+	/**
+	 * @brief Handler for received SIG_CHILD signals.
+	 *
+	 * Dumm spans children, UML kernels. To track and cleanup these kernel
+	 * processes, it is required that this method is called whenever a SIG_CHILD
+	 * is received. The user is responsible to call sigchild_handler on each
+	 * dumm_t instance with the signals siginfo_t. 
+	 *
+	 * @param info		siginfo associated to the SIG_CHILD signal
+	 */
+	void (*sigchild_handler)(dumm_t *this, siginfo_t *info);
+	
 	/**
 	 * @brief stop all guests and destroy the modeler
 	 */

src/dumm/guest.c

@@ -78,7 +78,7 @@ static iface_t* create_iface(private_guest_t *this, char *name)
 	iterator_t *iterator;
 	iface_t *iface;
 	
-	if (this->pid == 0)
+	if (this->state != GUEST_RUNNING)
 	{
 		DBG1("guest '%s' not running, unable to add interface", this->name);
 		return NULL;
@@ -225,13 +225,28 @@ static bool start(private_guest_t *this, char *kernel)
  */
 static void stop(private_guest_t *this)
 {
-	if (this->pid)
+	if (this->state != GUEST_STOPPED)
 	{
+		this->ifaces->destroy_offset(this->ifaces, offsetof(iface_t, destroy));
+		this->ifaces = linked_list_create();
 		kill(this->pid, SIGINT);
-		this->pid = 0;
+		this->state = GUEST_STOPPING;
+		while (this->state == GUEST_STOPPING)
+		{
+			sched_yield();
+		}
 	}
 }
 
+/**
+ * Implementation of guest_t.sigchild.
+ */
+static void sigchild(private_guest_t *this)
+{
+	this->state = GUEST_STOPPED;
+	this->pid = 0;
+}
+
 /**
  * Check if directory exists, create otherwise
  */
@@ -326,7 +341,6 @@ 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->master);
@@ -347,6 +361,7 @@ guest_t *guest_create(char *name, char *master, int mem)
 	this->public.create_iface_iterator = (iterator_t*(*)(guest_t*))create_iface_iterator;
 	this->public.start = (void*)start;
 	this->public.stop = (void*)stop;
+	this->public.sigchild = (void(*)(guest_t*))sigchild;
 	this->public.destroy = (void*)destroy;
 	
 	if (!makedir(HOST_DIR, name) || !makedir(MOUNT_DIR, name) ||

src/dumm/guest.h

@@ -100,7 +100,12 @@ struct guest_t {
 	 * @return		iterator over iface_t's
 	 */
 	iterator_t* (*create_iface_iterator)(guest_t *this);
-
+	
+	/**
+	 * @brief Called whenever a SIGCHILD is received.
+	 */
+	void (*sigchild)(guest_t *this);
+	
 	/**
 	 * @brief Close and destroy a guest with all interfaces
 	 */	

src/dumm/main.c

@@ -24,6 +24,11 @@
 
 #include "dumm.h"
 
+/**
+ * global set of UMLs guests
+ */
+dumm_t *dumm;
+
 /**
  * show usage information (program arguments)
  */
@@ -53,7 +58,8 @@ static void help()
  */
 static void help_guest()
 {
-	printf("start [kernel=<uml-kernel>]   start the guest\n");
+	printf("start [kernel=<uml-kernel>]   start a stopped guest\n");
+	printf("stop                          stop a started guest\n");
 	printf("addif <name>                  add an interface to the guest\n");
 	printf("delif <name>                  remove the interface\n");
 	printf("listif                        list guests interfaces\n");
@@ -171,10 +177,20 @@ static void start_guest(guest_t *guest, char *line)
 	}
 }
 
+/**
+ * stop (kill) an UML guest
+ */
+static void stop_guest(guest_t *guest, char *line)
+{	
+	printf("stopping guest '%s'...\n", guest->get_name(guest));
+	guest->stop(guest);
+	printf("guest '%s' is down\n", guest->get_name(guest));
+}
+
 /**
  * subshell for guests
  */
-static void guest(dumm_t *dumm, char *name)
+static void guest(char *name)
 {
 	char *line = NULL;
 	char prompt[32];
@@ -211,6 +227,7 @@ static void guest(dumm_t *dumm, char *name)
 			QUIT = 0,
 			HELP,
 			START,
+			STOP,
 			ADDIF,
 			DELIF,
 			LISTIF,
@@ -219,6 +236,7 @@ static void guest(dumm_t *dumm, char *name)
 			[QUIT] = "quit",
 			[HELP] = "help",
 			[START] = "start",
+			[STOP] = "stop",
 			[ADDIF] = "addif",
 			[DELIF] = "delif",
 			[LISTIF] = "listif",
@@ -254,6 +272,9 @@ static void guest(dumm_t *dumm, char *name)
 			case START:
 				start_guest(guest, pos);
 				continue;
+			case STOP:
+				stop_guest(guest, pos);
+				continue;
 			case ADDIF:
 				add_if(guest, pos);
 				continue;
@@ -274,7 +295,7 @@ static void guest(dumm_t *dumm, char *name)
 /**
  * create an UML guest
  */
-static void create_guest(dumm_t *dumm, char *line)
+static void create_guest(char *line)
 {
 	enum {
 		NAME = 0,
@@ -330,7 +351,7 @@ static void create_guest(dumm_t *dumm, char *line)
 	if (dumm->create_guest(dumm, name, master, mem))
 	{
 		printf("guest '%s' created\n", name);
-		guest(dumm, name);
+		guest(name);
 	}
 	else
 	{
@@ -341,7 +362,7 @@ static void create_guest(dumm_t *dumm, char *line)
 /**
  * list running UML guests
  */
-static void list(dumm_t *dumm)
+static void list()
 {
 	iterator_t *guests, *ifaces;
 	guest_t *guest;
@@ -350,7 +371,8 @@ static void list(dumm_t *dumm)
 	guests = dumm->create_guest_iterator(dumm);
 	while (guests->iterate(guests, (void**)&guest))
 	{
-		printf("%s\n", guest->get_name(guest));
+		printf("%s (%N)\n", guest->get_name(guest),
+			   guest_state_names, guest->get_state(guest));
 		ifaces = guest->create_iface_iterator(guest);
 		while (ifaces->iterate(ifaces, (void**)&iface))
 		{
@@ -362,13 +384,31 @@ static void list(dumm_t *dumm)
 	guests->destroy(guests);
 }
 
+/**
+ * Signal handler 
+ */
+void signal_action(int sig, siginfo_t *info, void *ucontext)
+{
+	if (sig == SIGCHLD)
+	{
+		dumm->sigchild_handler(dumm, info);
+	}
+	else
+	{
+		dumm->destroy(dumm);
+		clear_history();
+		printf("\n");
+		exit(0);
+	}
+}
+
 /**
  * main routine, parses args and reads from console
  */
 int main(int argc, char *argv[])
 {
-	dumm_t *dumm;
 	char *line = NULL;
+	struct sigaction action;
 
 	while (TRUE)
 	{
@@ -400,6 +440,18 @@ int main(int argc, char *argv[])
 	}
 	
 	dumm = dumm_create();
+	
+	memset(&action, 0, sizeof(action));
+	action.sa_sigaction = signal_action;
+	action.sa_flags = SA_SIGINFO;
+	if (sigaction(SIGCHLD, &action, NULL) != 0 ||
+		sigaction(SIGINT, &action, NULL) != 0 ||
+		sigaction(SIGQUIT, &action, NULL) != 0 ||
+		sigaction(SIGTERM, &action, NULL) != 0)
+	{
+		printf("signal handler setup failed: %m.\n");
+		return 1;
+	}
 
 	while (TRUE)
 	{
@@ -447,13 +499,13 @@ int main(int argc, char *argv[])
 				help();
 				continue;
 			case CREATE:
-				create_guest(dumm, pos);
+				create_guest(pos);
 				continue;
 			case LIST:
-				list(dumm);
+				list();
 				continue;
 			case GUEST:
-				guest(dumm, pos);
+				guest(pos);
 				continue;
 			default:
 				printf("command unknown: '%s'\n", line);