Link LXC with USERCR

index 7db1d85..4be6f92 100644
@@ -38,11 +38,19 @@
 lxc_log_define(lxc_restart_ui, lxc_restart);
 
 static struct lxc_list defines;
+static char *statedir;
 
 static int my_checker(const struct lxc_arguments* args)
 {
-	if (!args->statefile) {
-		lxc_error(args, "no statefile specified");
+	int d, f;
+
+	/* make them boolean */
+	d = !!(statedir);
+	f = !!(args->statefile);
+
+	if (!(d ^ f)) {
+		lxc_error(args, "Must specify exactly one of --directory "
+				"and --statefile options");
 		return -1;
 	}
 

@@ -52,8 +60,9 @@ static int my_checker(const struct lxc_arguments* args)
 static int my_parser(struct lxc_arguments* args, int c, char* arg)
 {
 	switch (c) {
-	case 'd': args->statefile = arg; break;
+	case 'd': statedir = arg; break;
 	case 'f': args->rcfile = arg; break;
+	case 'S': args->statefile = arg; break;
 	case 'p': args->flags = LXC_FLAG_PAUSE; break;
 	case 's': return lxc_config_define_add(&defines, arg);
 	}

@@ -66,21 +75,24 @@ static const struct option my_longopts[] = {
 	{"rcfile", required_argument, 0, 'f'},
 	{"pause", no_argument, 0, 'p'},
 	{"define", required_argument, 0, 's'},
+	{"statefile", required_argument, 0, 'S'},
 	LXC_COMMON_OPTIONS
 };
 
 static struct lxc_arguments my_args = {
 	.progname = "lxc-restart",
 	.help     = "\
---name=NAME --directory STATEFILE\n\
+--name=NAME --directory STATEFILE (deprecated)\n\
+\tlxc_restart --name=NAME --statefile=STATEFILE\n\
 \n\
 lxc-restart restarts from STATEFILE the NAME container\n\
 \n\
 Options :\n\
   -n, --name=NAME      NAME for name of the container\n\
   -p, --pause          do not release the container after the restart\n\
-  -d, --directory=STATEFILE for name of statefile\n\
+  -d, --directory=STATEFILE for name of statefile (legacy mode, deprecated)\n\
   -f, --rcfile=FILE Load configuration file FILE\n\
+  -i, --statefile=STATEFILE Load the application state from STATEFILE (libcr mode)\n\
   -s, --define KEY=VAL Assign VAL to configuration variable KEY\n",
 	.options  = my_longopts,
 	.parser   = my_parser,

@@ -90,6 +102,7 @@ Options :\n\
 int main(int argc, char *argv[])
 {
 	char *rcfile = NULL;
+	const char *statefile;
 	struct lxc_conf *conf;
 
 	lxc_list_init(&defines);

@@ -131,6 +144,9 @@ int main(int argc, char *argv[])
 	if (lxc_config_define_load(&defines, conf))
 		return -1;
 
-	return lxc_restart(my_args.name, my_args.statefile, conf,
-			   my_args.flags);
+	statefile = my_args.statefile;
+	if (statedir)
+		statefile = statedir;
+
+	return lxc_restart(my_args.name, statefile, conf, my_args.flags);
 }

index a8c74a9..b0cd634 100644
@@ -37,10 +37,19 @@
 
 lxc_log_define(lxc_checkpoint_ui, lxc_checkpoint);
 
+static char *statedir;
+
 static int my_checker(const struct lxc_arguments* args)
 {
-	if (!args->statefile) {
-		lxc_error(args, "no statefile specified");
+	int d, f;
+
+	/* make them boolean */
+	d = !!(statedir);
+	f = !!(args->statefile);
+
+	if (!(d ^ f)) {
+		lxc_error(args, "Must specify exactly one of --directory "
+				"and --statefile options");
 		return -1;
 	}
 

@@ -52,7 +61,8 @@ static int my_parser(struct lxc_arguments* args, int c, char* arg)
 	switch (c) {
 	case 'k': args->flags = LXC_FLAG_HALT; break;
 	case 'p': args->flags = LXC_FLAG_PAUSE; break;
-	case 'd': args->statefile = arg; break;
+	case 'd': statedir = arg; break;
+	case 'S': args->statefile = arg; break;
 	}
 	return 0;
 }

@@ -61,13 +71,15 @@ static const struct option my_longopts[] = {
 	{"kill", no_argument, 0, 'k'},
 	{"pause", no_argument, 0, 'p'},
 	{"directory", required_argument, 0, 'd'},
+	{"statefile", required_argument, 0, 'S'},
 	LXC_COMMON_OPTIONS
 };
 
 static struct lxc_arguments my_args = {
 	.progname = "lxc-checkpoint",
 	.help     = "\
---name=NAME --directory STATEFILE\n\
+--name=NAME --directory STATEFILE (deprecated)\n\
+\tlxc_checkpoint --name=NAME --statefile=STATEFILE\n\
 \n\
 lxc-checkpoint checkpoints in STATEFILE the NAME container\n\
 \n\

@@ -75,7 +87,8 @@ Options :\n\
   -n, --name=NAME      NAME for name of the container\n\
   -k, --kill           stop the container after checkpoint\n\
   -p, --pause          don't unfreeze the container after the checkpoint\n\
-  -d, --directory=STATEFILE where to store the statefile\n",
+  -d, --directory=STATEFILE where to store the statefile (deprecated)\n\
+  -i, --statefile=STATEFILE where to store the checkpoint-image (LIBCR mode)\n",
 
 	.options  = my_longopts,
 	.parser   = my_parser,

@@ -97,6 +110,7 @@ static int create_statefile(const char *dir)
 int main(int argc, char *argv[])
 {
 	int ret;
+	const char *statefile;
 
 	ret = lxc_arguments_parse(&my_args, argc, argv);
 	if (ret)

@@ -107,11 +121,15 @@ int main(int argc, char *argv[])
 	if (ret)
 		return ret;
 
-	ret = create_statefile(my_args.statefile);
-	if (ret)
-		return ret;
+	statefile = my_args.statefile;
+	if (statedir) {
+		statefile = statedir;
+		ret = create_statefile(statefile);
+		if (ret)
+			return ret;
+	}
 
-	ret = lxc_checkpoint(my_args.name, my_args.statefile, my_args.flags);
+	ret = lxc_checkpoint(my_args.name, statefile, my_args.flags);
 	if (ret)
 		ERROR("failed to checkpoint '%s'", my_args.name);
 	else

index 7e8a93e..4e75cb6 100644
@@ -22,9 +22,38 @@
  */
 #include <lxc/lxc.h>
 #include <lxc/log.h>
+#include <lxc/commands.h>
 
 lxc_log_define(lxc_checkpoint, lxc);
 
+pid_t get_init_pid(const char *name)
+{
+	struct lxc_command command = {
+		.request = { .type = LXC_COMMAND_PID },
+	};
+
+	int ret, stopped = 0;
+
+	ret = lxc_command(name, &command, &stopped);
+	if (ret < 0 && stopped) {
+		INFO("'%s' is already stopped", name);
+		return 0;
+	}
+
+	if (ret < 0) {
+		ERROR("failed to send command");
+		return -1;
+	}
+
+	if (command.answer.ret) {
+		ERROR("failed to retrieve the init pid: %s",
+		      strerror(-command.answer.ret));
+		return -1;
+	}
+
+	return command.answer.pid;
+}
+
 int lxc_checkpoint(const char *name, const char *statefile, int flags)
 {
 	return 0;

index b0b9f4e..bd87bdb 100644
@@ -27,6 +27,7 @@
 extern "C" {
 #endif
 
+#include <unistd.h>
 #include <stddef.h>
 #include <lxc/state.h>
 

@@ -56,6 +57,11 @@ extern int lxc_start(const char *name, char *const argv[], struct lxc_conf *);
 extern int lxc_stop(const char *name);
 
 /*
+ * Get the pid of the root application process tree in parent-pid namespace
+ */
+extern pid_t get_init_pid(const char *name);
+
+/*
  * Open the monitoring mechanism for a specific container
  * The function will return an fd corresponding to the events
  * Returns a file descriptor on success, < 0 otherwise

index a012c2c..3d2cdd5 100644
@@ -28,6 +28,7 @@
 #include "commands.h"
 #include "arguments.h"
 #include "namespace.h"
+#include "lxc.h"
 #include "log.h"
 
 lxc_log_define(lxc_attach_ui, lxc);

@@ -50,34 +51,6 @@ Options :\n\
 	.checker  = NULL,
 };
 
-pid_t get_init_pid(const char *name)
-{
-	struct lxc_command command = {
-		.request = { .type = LXC_COMMAND_PID },
-	};
-
-	int ret, stopped = 0;
-
-	ret = lxc_command(name, &command, &stopped);
-	if (ret < 0 && stopped) {
-		INFO("'%s' is already stopped", name);
-		return 0;
-	}
-
-	if (ret < 0) {
-		ERROR("failed to send command");
-		return -1;
-	}
-
-	if (command.answer.ret) {
-		ERROR("failed to retrieve the init pid: %s",
-		      strerror(-command.answer.ret));
-		return -1;
-	}
-
-	return command.answer.pid;
-}
-
 int main(int argc, char *argv[], char *envp[])
 {
 	int ret;

index 467489e..c9ff565 100644
@@ -22,11 +22,138 @@
  */
 #include <lxc/lxc.h>
 #include <lxc/log.h>
+#include <lxc/start.h>
+#include <lxc/namespace.h>
+#include <lxc/cgroup.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/prctl.h>
+#include <sys/wait.h>
+#include "error.h"
+#ifdef LIBCR
+#include <app-checkpoint.h>
+#endif
 
 lxc_log_define(lxc_restart, lxc);
 
+#ifdef LIBCR
+
+struct lxc_restart_arg {
+	const char *name;
+	const char *statefile;
+	char *const argv;
+	struct lxc_handler *handler;
+	int lxc_flags;
+};
+
+static int do_restart(struct lxc_restart_arg *lxcarg)
+{
+	int pid;
+	int lxc_flags = lxcarg->lxc_flags;
+	struct lxc_handler *handler = lxcarg->handler;
+	const char *statefile = lxcarg->statefile;
+	struct app_restart_args restart_args;
+
+	if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL)) {
+		SYSERROR("failed to set sigprocmask");
+		return -1;
+	}
+
+	if (prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0)) {
+		SYSERROR("failed to set pdeath signal");
+		return -1;
+	}
+
+	memset(&restart_args, 0, sizeof(restart_args));
+
+	restart_args.infd = open(statefile, O_RDONLY, 0);
+	if (restart_args.infd < 0) {
+		SYSERROR("Failed to open statefile %s\n", statefile);
+		return -1;
+	}
+
+	restart_args.pids = 1;
+	restart_args.pidns = 1;
+	restart_args.mnt_pty = 1;
+	restart_args.mntns = 1;
+	restart_args.klogfd = -1;
+	restart_args.ulogfd = lxc_log_fd;
+	restart_args.uerrfd = fileno(stderr);
+	restart_args.debug = 1;
+	restart_args.wait = 0;
+
+	if (lxc_flags & LXC_FLAG_PAUSE)
+		restart_args.keep_frozen = 1;
+
+	pid = app_restart(&restart_args);
+
+	return pid;
+}
+
 int lxc_restart(const char *name, const char *statefile, struct lxc_conf *conf,
-		int flags)
+		int lxc_flags)
 {
+	int err;
+	int status;
+	struct lxc_handler *handler;
+	struct lxc_restart_arg lxcarg = {
+		.name = name,
+		.statefile = statefile,
+		.lxc_flags = lxc_flags,
+		.handler = NULL,
+	};
+
+	if (lxc_check_inherited())
+		return -1;
+
+	handler = lxc_init(name, conf);
+	if (!handler) {
+		ERROR("failed to initialize the container");
+		return -1;
+	}
+
+	lxcarg.handler = handler;
+	handler->pid = do_restart(&lxcarg);
+
+	INFO("do_restart(): returns pid %d\n", handler->pid);
+	lxc_rename_nsgroup(name, handler);
+
+	err = lxc_poll(name, handler);
+	if (err) {
+		ERROR("mainloop exited with an error");
+		goto out_abort;
+	}
+
+	while (waitpid(handler->pid, &status, 0) < 0 && errno == EINTR)
+		continue;
+
+	if (!(lxc_flags & LXC_FLAG_PAUSE)) {
+		err = lxc_unfreeze(name);
+		if (err) {
+			ERROR("lxc_restart(): Unable to unfreeze\n");
+			goto out_fini;
+		}
+	}
+
+	err =  lxc_error_set_and_log(handler->pid, status);
+
+out_fini:
+	lxc_fini(name, handler);
+	return err;
+
+out_abort:
+	lxc_abort(name, handler);
+	goto out_fini;
+
 	return 0;
 }
+#else
+int lxc_restart(const char *name, const char *statefile, struct lxc_conf *conf,
+		int lxc_flags)
+{
+	ERROR("'restart' function not configured");
+	ERROR("Try --with-libcr option to 'configure' script");
+	return -1;
+}
+#endif

index 4e75cb6..d861ce1 100644
@@ -22,7 +22,17 @@
  */
 #include <lxc/lxc.h>
 #include <lxc/log.h>
-#include <lxc/commands.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <linux/checkpoint.h>
+
+#include "commands.h"
+#include "arguments.h"
+#include "namespace.h"
+#ifdef LIBCR
+#include "app-checkpoint.h"
+#endif
 
 lxc_log_define(lxc_checkpoint, lxc);
 

@@ -54,7 +64,81 @@ pid_t get_init_pid(const char *name)
 	return command.answer.pid;
 }
 
-int lxc_checkpoint(const char *name, const char *statefile, int flags)
+#ifdef LIBCR
+int lxc_checkpoint(const char *name, const char *statefile, int lxc_flags)
 {
+	int ret;
+	int pid;
+	int flags;
+	struct app_checkpoint_args crargs;
+
+	pid = get_init_pid(name);
+	if (pid < 0) {
+		ERROR("Unable to find cinit pid");
+		return -1;
+	}
+
+	ret = lxc_freeze(name);
+	if (ret < 0)
+		return ret;
+
+	memset(&crargs, 0, sizeof(crargs));
+
+	ret = open(statefile, O_CREAT|O_RDWR|O_EXCL, 0600);
+	if (ret < 0) {
+		ERROR("open(%s) failed, %s\n", statefile, strerror(errno));
+		return -1;
+	}
+
+	crargs.outfd = ret;
+	crargs.logfd = lxc_log_fd;
+	crargs.uerrfd = lxc_log_fd;
+	/*
+	 * TODO: Set this to 0 for now - otherwise we get an objhash leak
+	 * 	 due to mismatched references to current PTY which needs to
+	 * 	 be investigated.
+	 *
+	 * TODO: Map @lxc_flags to user-cr flags ?
+	 *
+	 * TODO: We can probably drop the ->container field since @flags
+	 * 	 can provide the same selection.
+	 *
+	 * TODO: Do we may need a --container option to lxc_checkpoint or
+	 * 	 assume that we always work with full containers ?
+	 */
+	crargs.container = 0;
+
+	/*
+	 * TODO: Set the CHECKPOINT_NONETNS unconditionally for now. Otherwise
+	 * 	 it would require running the application in a private netns.
+	 * 	 Implement a command-line option to allow user selection.
+	 */
+	flags = CHECKPOINT_SUBTREE|CHECKPOINT_NONETNS;
+
+	ret = app_checkpoint(pid, flags, &crargs);
+	if (ret < 0) {
+		ERROR("checkpoint of %s (pid %d) failed\n", name, pid);
+		return -1;
+	}
+
+	if (lxc_flags & LXC_FLAG_HALT) {
+		ret = lxc_stop(name);
+		if (ret < 0)
+			return ret;
+
+		return lxc_unfreeze(name);
+	}
+
+	if (!(lxc_flags & LXC_FLAG_PAUSE))
+		return lxc_unfreeze(name);
+
 	return 0;
 }
+#else
+int lxc_checkpoint(const char *name, const char *statefile, int lxc_flags)
+{
+	ERROR("'checkpoint' not configured");
+	ERROR("Try --with-libcr option to 'configure' script");
+	return -1;
+}
+#endif

index b29ae09..1e4c7e1 100644
@@ -167,4 +167,3 @@ extern int lxc_state_callback(int fd, struct lxc_request *request,
 out:
 	return ret;
 }
-