[weston,v2,13/17] libweston: make a shared library for compositor launchers

Submitted by Giulio Camuffo on Dec. 4, 2014, 9:01 p.m.

Details

Message ID 1417726883-8305-14-git-send-email-giuliocamuffo@gmail.com
State Superseded
Headers show

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Commit Message

Giulio Camuffo Dec. 4, 2014, 9:01 p.m.
---
 Makefile.am           |  21 +-
 src/weston-launch.c   | 698 +--------------------------------------------
 src/weston-launcher.c | 769 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/weston-launcher.h |  45 +++
 4 files changed, 845 insertions(+), 688 deletions(-)
 create mode 100644 src/weston-launcher.c
 create mode 100644 src/weston-launcher.h

Patch hide | download patch | download mbox

diff --git a/Makefile.am b/Makefile.am
index 8f2ba15..38b835a 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -141,15 +141,25 @@  endif
 .FORCE :
 
 if BUILD_WESTON_LAUNCH
-bin_PROGRAMS += weston-launch
-weston_launch_SOURCES = src/weston-launch.c src/weston-launch.h
-weston_launch_CPPFLAGS = -DBINDIR='"$(bindir)"'
-weston_launch_CFLAGS=				\
+lib_LTLIBRARIES += libweston-launcher.la
+libweston_launcher_la_CPPFLAGS = $(AM_CPPFLAGS)
+libweston_launcher_la_LIBADD = $(PAM_LIBS) $(SYSTEMD_LOGIN_LIBS) $(LIBDRM_LIBS)
+libweston_launcher_la_CFLAGS =			\
 	$(GCC_CFLAGS)				\
 	$(PAM_CFLAGS)				\
 	$(SYSTEMD_LOGIN_CFLAGS)			\
 	$(LIBDRM_CFLAGS)
-weston_launch_LDADD = $(PAM_LIBS) $(SYSTEMD_LOGIN_LIBS) $(LIBDRM_LIBS)
+libweston_launcher_la_SOURCES = 		\
+	src/weston-launcher.c		\
+	src/weston-launch.h		\
+	src/weston-launcher.h
+
+bin_PROGRAMS += weston-launch
+weston_launch_SOURCES = src/weston-launch.c
+weston_launch_CPPFLAGS = -DBINDIR='"$(bindir)"' -I$(top_srcdir)/libweston
+weston_launch_CFLAGS=				\
+	$(GCC_CFLAGS)
+weston_launch_LDADD = libweston-launcher.la
 
 if ENABLE_SETUID_INSTALL
 install-exec-hook:
@@ -168,6 +178,7 @@  westoninclude_HEADERS =				\
 	src/compositor.h			\
 	src/compositor-x11.h			\
 	src/compositor-drm.h			\
+	src/weston-launcher.h			\
 	shared/matrix.h				\
 	shared/config-parser.h			\
 	shared/zalloc.h
diff --git a/src/weston-launch.c b/src/weston-launch.c
index 10c66de..1ae2646 100644
--- a/src/weston-launch.c
+++ b/src/weston-launch.c
@@ -43,620 +43,7 @@ 
 #include <unistd.h>
 #include <fcntl.h>
 
-#include <linux/vt.h>
-#include <linux/major.h>
-#include <linux/kd.h>
-
-#include <pwd.h>
-#include <grp.h>
-#include <security/pam_appl.h>
-
-#ifdef HAVE_SYSTEMD_LOGIN
-#include <systemd/sd-login.h>
-#endif
-
-#include "weston-launch.h"
-
-#define DRM_MAJOR 226
-
-#ifndef KDSKBMUTE
-#define KDSKBMUTE	0x4B51
-#endif
-
-#ifndef EVIOCREVOKE
-#define EVIOCREVOKE _IOW('E', 0x91, int)
-#endif
-
-#define MAX_ARGV_SIZE 256
-
-#ifdef HAVE_LIBDRM
-
-#include <xf86drm.h>
-
-#else
-
-static inline int
-drmDropMaster(int drm_fd)
-{
-	return 0;
-}
-
-static inline int
-drmSetMaster(int drm_fd)
-{
-	return 0;
-}
-
-#endif
-
-struct weston_launch {
-	struct pam_conv pc;
-	pam_handle_t *ph;
-	int tty;
-	int ttynr;
-	int sock[2];
-	int drm_fd;
-	int last_input_fd;
-	int kb_mode;
-	struct passwd *pw;
-
-	int signalfd;
-
-	pid_t child;
-	int verbose;
-	char *new_user;
-};
-
-union cmsg_data { unsigned char b[4]; int fd; };
-
-static gid_t *
-read_groups(void)
-{
-	int n;
-	gid_t *groups;
-	
-	n = getgroups(0, NULL);
-
-	if (n < 0) {
-		fprintf(stderr, "Unable to retrieve groups: %m\n");
-		return NULL;
-	}
-
-	groups = malloc(n * sizeof(gid_t));
-	if (!groups)
-		return NULL;
-
-	if (getgroups(n, groups) < 0) {
-		fprintf(stderr, "Unable to retrieve groups: %m\n");
-		free(groups);
-		return NULL;
-	}
-	return groups;
-}
-
-static bool
-weston_launch_allowed(struct weston_launch *wl)
-{
-	struct group *gr;
-	gid_t *groups;
-	int i;
-#ifdef HAVE_SYSTEMD_LOGIN
-	char *session, *seat;
-	int err;
-#endif
-
-	if (getuid() == 0)
-		return true;
-
-	gr = getgrnam("weston-launch");
-	if (gr) {
-		groups = read_groups();
-		if (groups) {
-			for (i = 0; groups[i]; ++i) {
-				if (groups[i] == gr->gr_gid) {
-					free(groups);
-					return true;
-				}
-			}
-			free(groups);
-		}
-	}
-
-#ifdef HAVE_SYSTEMD_LOGIN
-	err = sd_pid_get_session(getpid(), &session);
-	if (err == 0 && session) {
-		if (sd_session_is_active(session) &&
-		    sd_session_get_seat(session, &seat) == 0) {
-			free(seat);
-			free(session);
-			return true;
-		}
-		free(session);
-	}
-#endif
-	
-	return false;
-}
-
-static int
-pam_conversation_fn(int msg_count,
-		    const struct pam_message **messages,
-		    struct pam_response **responses,
-		    void *user_data)
-{
-	return PAM_SUCCESS;
-}
-
-static int
-setup_pam(struct weston_launch *wl)
-{
-	int err;
-
-	wl->pc.conv = pam_conversation_fn;
-	wl->pc.appdata_ptr = wl;
-
-	err = pam_start("login", wl->pw->pw_name, &wl->pc, &wl->ph);
-	if (err != PAM_SUCCESS) {
-		fprintf(stderr, "failed to start pam transaction: %d: %s\n",
-			err, pam_strerror(wl->ph, err));
-		return -1;
-	}
-
-	err = pam_set_item(wl->ph, PAM_TTY, ttyname(wl->tty));
-	if (err != PAM_SUCCESS) {
-		fprintf(stderr, "failed to set PAM_TTY item: %d: %s\n",
-			err, pam_strerror(wl->ph, err));
-		return -1;
-	}
-
-	err = pam_open_session(wl->ph, 0);
-	if (err != PAM_SUCCESS) {
-		fprintf(stderr, "failed to open pam session: %d: %s\n",
-			err, pam_strerror(wl->ph, err));
-		return -1;
-	}
-
-	return 0;
-}
-
-static int
-setup_launcher_socket(struct weston_launch *wl)
-{
-	if (socketpair(AF_LOCAL, SOCK_SEQPACKET, 0, wl->sock) < 0)
-		error(1, errno, "socketpair failed");
-	
-	if (fcntl(wl->sock[0], F_SETFD, FD_CLOEXEC) < 0)
-		error(1, errno, "fcntl failed");
-
-	return 0;
-}
-
-static int
-setup_signals(struct weston_launch *wl)
-{
-	int ret;
-	sigset_t mask;
-	struct sigaction sa;
-
-	memset(&sa, 0, sizeof sa);
-	sa.sa_handler = SIG_DFL;
-	sa.sa_flags = SA_NOCLDSTOP | SA_RESTART;
-	ret = sigaction(SIGCHLD, &sa, NULL);
-	assert(ret == 0);
-
-	sa.sa_handler = SIG_IGN;
-	sa.sa_flags = 0;
-	sigaction(SIGHUP, &sa, NULL);
-
-	ret = sigemptyset(&mask);
-	assert(ret == 0);
-	sigaddset(&mask, SIGCHLD);
-	sigaddset(&mask, SIGINT);
-	sigaddset(&mask, SIGTERM);
-	sigaddset(&mask, SIGUSR1);
-	sigaddset(&mask, SIGUSR2);
-	ret = sigprocmask(SIG_BLOCK, &mask, NULL);
-	assert(ret == 0);
-
-	wl->signalfd = signalfd(-1, &mask, SFD_NONBLOCK | SFD_CLOEXEC);
-	if (wl->signalfd < 0)
-		return -errno;
-
-	return 0;
-}
-
-static void
-setenv_fd(const char *env, int fd)
-{
-	char buf[32];
-
-	snprintf(buf, sizeof buf, "%d", fd);
-	setenv(env, buf, 1);
-}
-
-static int
-send_reply(struct weston_launch *wl, int reply)
-{
-	int len;
-
-	do {
-		len = send(wl->sock[0], &reply, sizeof reply, 0);
-	} while (len < 0 && errno == EINTR);
-
-	return len;
-}
-
-static int
-handle_open(struct weston_launch *wl, struct msghdr *msg, ssize_t len)
-{
-	int fd = -1, ret = -1;
-	char control[CMSG_SPACE(sizeof(fd))];
-	struct cmsghdr *cmsg;
-	struct stat s;
-	struct msghdr nmsg;
-	struct iovec iov;
-	struct weston_launcher_open *message;
-	union cmsg_data *data;
-
-	message = msg->msg_iov->iov_base;
-	if ((size_t)len < sizeof(*message))
-		goto err0;
-
-	/* Ensure path is null-terminated */
-	((char *) message)[len-1] = '\0';
-
-	fd = open(message->path, message->flags);
-	if (fd < 0) {
-		fprintf(stderr, "Error opening device %s: %m\n",
-			message->path);
-		goto err0;
-	}
-
-	if (fstat(fd, &s) < 0) {
-		close(fd);
-		fd = -1;
-		fprintf(stderr, "Failed to stat %s\n", message->path);
-		goto err0;
-	}
-
-	if (major(s.st_rdev) != INPUT_MAJOR &&
-	    major(s.st_rdev) != DRM_MAJOR) {
-		close(fd);
-		fd = -1;
-		fprintf(stderr, "Device %s is not an input or drm device\n",
-			message->path);
-		goto err0;
-	}
-
-err0:
-	memset(&nmsg, 0, sizeof nmsg);
-	nmsg.msg_iov = &iov;
-	nmsg.msg_iovlen = 1;
-	if (fd != -1) {
-		nmsg.msg_control = control;
-		nmsg.msg_controllen = sizeof control;
-		cmsg = CMSG_FIRSTHDR(&nmsg);
-		cmsg->cmsg_level = SOL_SOCKET;
-		cmsg->cmsg_type = SCM_RIGHTS;
-		cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
-		data = (union cmsg_data *) CMSG_DATA(cmsg);
-		data->fd = fd;
-		nmsg.msg_controllen = cmsg->cmsg_len;
-		ret = 0;
-	}
-	iov.iov_base = &ret;
-	iov.iov_len = sizeof ret;
-
-	if (wl->verbose)
-		fprintf(stderr, "weston-launch: opened %s: ret: %d, fd: %d\n",
-			message->path, ret, fd);
-	do {
-		len = sendmsg(wl->sock[0], &nmsg, 0);
-	} while (len < 0 && errno == EINTR);
-
-	if (len < 0)
-		return -1;
-
-	if (fd != -1 && major(s.st_rdev) == DRM_MAJOR)
-		wl->drm_fd = fd;
-	if (fd != -1 && major(s.st_rdev) == INPUT_MAJOR &&
-	    wl->last_input_fd < fd)
-		wl->last_input_fd = fd;
-
-	return 0;
-}
-
-static int
-handle_socket_msg(struct weston_launch *wl)
-{
-	char control[CMSG_SPACE(sizeof(int))];
-	char buf[BUFSIZ];
-	struct msghdr msg;
-	struct iovec iov;
-	int ret = -1;
-	ssize_t len;
-	struct weston_launcher_message *message;
-
-	memset(&msg, 0, sizeof(msg));
-	iov.iov_base = buf;
-	iov.iov_len  = sizeof buf;
-	msg.msg_iov = &iov;
-	msg.msg_iovlen = 1;
-	msg.msg_control = control;
-	msg.msg_controllen = sizeof control;
-
-	do {
-		len = recvmsg(wl->sock[0], &msg, 0);
-	} while (len < 0 && errno == EINTR);
-
-	if (len < 1)
-		return -1;
-
-	message = (void *) buf;
-	switch (message->opcode) {
-	case WESTON_LAUNCHER_OPEN:
-		ret = handle_open(wl, &msg, len);
-		break;
-	}
-
-	return ret;
-}
-
-static void
-quit(struct weston_launch *wl, int status)
-{
-	struct vt_mode mode = { 0 };
-	int err;
-
-	close(wl->signalfd);
-	close(wl->sock[0]);
-
-	if (wl->new_user) {
-		err = pam_close_session(wl->ph, 0);
-		if (err)
-			fprintf(stderr, "pam_close_session failed: %d: %s\n",
-				err, pam_strerror(wl->ph, err));
-		pam_end(wl->ph, err);
-	}
-
-	if (ioctl(wl->tty, KDSKBMUTE, 0) &&
-	    ioctl(wl->tty, KDSKBMODE, wl->kb_mode))
-		fprintf(stderr, "failed to restore keyboard mode: %m\n");
-
-	if (ioctl(wl->tty, KDSETMODE, KD_TEXT))
-		fprintf(stderr, "failed to set KD_TEXT mode on tty: %m\n");
-
-	/* We have to drop master before we switch the VT back in
-	 * VT_AUTO, so we don't risk switching to a VT with another
-	 * display server, that will then fail to set drm master. */
-	drmDropMaster(wl->drm_fd);
-
-	mode.mode = VT_AUTO;
-	if (ioctl(wl->tty, VT_SETMODE, &mode) < 0)
-		fprintf(stderr, "could not reset vt handling\n");
-
-	exit(status);
-}
-
-static void
-close_input_fds(struct weston_launch *wl)
-{
-	struct stat s;
-	int fd;
-
-	for (fd = 3; fd <= wl->last_input_fd; fd++) {
-		if (fstat(fd, &s) == 0 && major(s.st_rdev) == INPUT_MAJOR) {
-			/* EVIOCREVOKE may fail if the kernel doesn't
-			 * support it, but all we can do is ignore it. */
-			ioctl(fd, EVIOCREVOKE, 0);
-			close(fd);
-		}
-	}
-}
-
-static int
-handle_signal(struct weston_launch *wl)
-{
-	struct signalfd_siginfo sig;
-	int pid, status, ret;
-
-	if (read(wl->signalfd, &sig, sizeof sig) != sizeof sig) {
-		error(0, errno, "reading signalfd failed");
-		return -1;
-	}
-
-	switch (sig.ssi_signo) {
-	case SIGCHLD:
-		pid = waitpid(-1, &status, 0);
-		if (pid == wl->child) {
-			wl->child = 0;
-			if (WIFEXITED(status))
-				ret = WEXITSTATUS(status);
-			else if (WIFSIGNALED(status))
-				/*
-				 * If weston dies because of signal N, we
-				 * return 10+N. This is distinct from
-				 * weston-launch dying because of a signal
-				 * (128+N).
-				 */
-				ret = 10 + WTERMSIG(status);
-			else
-				ret = 0;
-			quit(wl, ret);
-		}
-		break;
-	case SIGTERM:
-	case SIGINT:
-		if (wl->child)
-			kill(wl->child, sig.ssi_signo);
-		break;
-	case SIGUSR1:
-		send_reply(wl, WESTON_LAUNCHER_DEACTIVATE);
-		close_input_fds(wl);
-		drmDropMaster(wl->drm_fd);
-		ioctl(wl->tty, VT_RELDISP, 1);
-		break;
-	case SIGUSR2:
-		ioctl(wl->tty, VT_RELDISP, VT_ACKACQ);
-		drmSetMaster(wl->drm_fd);
-		send_reply(wl, WESTON_LAUNCHER_ACTIVATE);
-		break;
-	default:
-		return -1;
-	}
-
-	return 0;
-}
-
-static int
-setup_tty(struct weston_launch *wl, const char *tty)
-{
-	struct stat buf;
-	struct vt_mode mode = { 0 };
-	char *t;
-
-	if (!wl->new_user) {
-		wl->tty = STDIN_FILENO;
-	} else if (tty) {
-		t = ttyname(STDIN_FILENO);
-		if (t && strcmp(t, tty) == 0)
-			wl->tty = STDIN_FILENO;
-		else
-			wl->tty = open(tty, O_RDWR | O_NOCTTY);
-	} else {
-		int tty0 = open("/dev/tty0", O_WRONLY | O_CLOEXEC);
-		char filename[16];
-
-		if (tty0 < 0)
-			error(1, errno, "could not open tty0");
-
-		if (ioctl(tty0, VT_OPENQRY, &wl->ttynr) < 0 || wl->ttynr == -1)
-			error(1, errno, "failed to find non-opened console"); 
-
-		snprintf(filename, sizeof filename, "/dev/tty%d", wl->ttynr);
-		wl->tty = open(filename, O_RDWR | O_NOCTTY);
-		close(tty0);
-	}
-
-	if (wl->tty < 0)
-		error(1, errno, "failed to open tty");
-
-	if (fstat(wl->tty, &buf) == -1 ||
-	    major(buf.st_rdev) != TTY_MAJOR || minor(buf.st_rdev) == 0)
-		error(1, 0, "weston-launch must be run from a virtual terminal");
-
-	if (tty) {
-		if (fstat(wl->tty, &buf) < 0)
-			error(1, errno, "stat %s failed", tty);
-
-		if (major(buf.st_rdev) != TTY_MAJOR)
-			error(1, 0, "invalid tty device: %s", tty);
-
-		wl->ttynr = minor(buf.st_rdev);
-	}
-
-	if (ioctl(wl->tty, KDGKBMODE, &wl->kb_mode))
-		error(1, errno, "failed to get current keyboard mode: %m\n");
-
-	if (ioctl(wl->tty, KDSKBMUTE, 1) &&
-	    ioctl(wl->tty, KDSKBMODE, K_OFF))
-		error(1, errno, "failed to set K_OFF keyboard mode: %m\n");
-
-	if (ioctl(wl->tty, KDSETMODE, KD_GRAPHICS))
-		error(1, errno, "failed to set KD_GRAPHICS mode on tty: %m\n");
-
-	mode.mode = VT_PROCESS;
-	mode.relsig = SIGUSR1;
-	mode.acqsig = SIGUSR2;
-	if (ioctl(wl->tty, VT_SETMODE, &mode) < 0)
-		error(1, errno, "failed to take control of vt handling\n");
-
-	return 0;
-}
-
-static void
-setup_session(struct weston_launch *wl)
-{
-	char **env;
-	char *term;
-	int i;
-
-	if (wl->tty != STDIN_FILENO) {
-		if (setsid() < 0)
-			error(1, errno, "setsid failed");
-		if (ioctl(wl->tty, TIOCSCTTY, 0) < 0)
-			error(1, errno, "TIOCSCTTY failed - tty is in use");
-	}
-
-	term = getenv("TERM");
-	clearenv();
-	if (term)
-		setenv("TERM", term, 1);
-	setenv("USER", wl->pw->pw_name, 1);
-	setenv("LOGNAME", wl->pw->pw_name, 1);
-	setenv("HOME", wl->pw->pw_dir, 1);
-	setenv("SHELL", wl->pw->pw_shell, 1);
-
-	env = pam_getenvlist(wl->ph);
-	if (env) {
-		for (i = 0; env[i]; ++i) {
-			if (putenv(env[i]) < 0)
-				error(0, 0, "putenv %s failed", env[i]);
-		}
-		free(env);
-	}
-}
-
-static void
-drop_privileges(struct weston_launch *wl)
-{
-	if (setgid(wl->pw->pw_gid) < 0 ||
-#ifdef HAVE_INITGROUPS
-	    initgroups(wl->pw->pw_name, wl->pw->pw_gid) < 0 ||
-#endif
-	    setuid(wl->pw->pw_uid) < 0)
-		error(1, errno, "dropping privileges failed");
-}
-
-static void
-launch_compositor(struct weston_launch *wl, int argc, char *argv[])
-{
-	char *child_argv[MAX_ARGV_SIZE];
-	sigset_t mask;
-	int i;
-
-	if (wl->verbose)
-		printf("weston-launch: spawned weston with pid: %d\n", getpid());
-	if (wl->new_user)
-		setup_session(wl);
-
-	if (geteuid() == 0)
-		drop_privileges(wl);
-
-	setenv_fd("WESTON_TTY_FD", wl->tty);
-	setenv_fd("WESTON_LAUNCHER_SOCK", wl->sock[1]);
-
-	unsetenv("DISPLAY");
-
-	/* Do not give our signal mask to the new process. */
-	sigemptyset(&mask);
-	sigaddset(&mask, SIGTERM);
-	sigaddset(&mask, SIGCHLD);
-	sigaddset(&mask, SIGINT);
-	sigprocmask(SIG_UNBLOCK, &mask, NULL);
-
-	child_argv[0] = "/bin/sh";
-	child_argv[1] = "-l";
-	child_argv[2] = "-c";
-	child_argv[3] = BINDIR "/weston \"$@\"";
-	child_argv[4] = "weston";
-	for (i = 0; i < argc; ++i)
-		child_argv[5 + i] = argv[i];
-	child_argv[5 + i] = NULL;
-
-	execv(child_argv[0], child_argv);
-	error(1, errno, "exec failed");
-}
+#include "weston-launcher.h"
 
 static void
 help(const char *name)
@@ -671,31 +58,30 @@  help(const char *name)
 int
 main(int argc, char *argv[])
 {
-	struct weston_launch wl;
-	int i, c;
+	struct weston_launcher *wl;
+	int i, c, ret;
 	char *tty = NULL;
+	char *new_user = NULL;
+	int verbose = 0;
+
 	struct option opts[] = {
 		{ "user",    required_argument, NULL, 'u' },
 		{ "tty",     required_argument, NULL, 't' },
 		{ "verbose", no_argument,       NULL, 'v' },
 		{ "help",    no_argument,       NULL, 'h' },
 		{ 0,         0,                 NULL,  0  }
-	};	
-
-	memset(&wl, 0, sizeof wl);
+	};
 
 	while ((c = getopt_long(argc, argv, "u:t::vh", opts, &i)) != -1) {
 		switch (c) {
 		case 'u':
-			wl.new_user = optarg;
-			if (getuid() != 0)
-				error(1, 0, "Permission denied. -u allowed for root only");
+			new_user = optarg;
 			break;
 		case 't':
 			tty = optarg;
 			break;
 		case 'v':
-			wl.verbose = 1;
+			verbose = 1;
 			break;
 		case 'h':
 			help("weston-launch");
@@ -703,67 +89,13 @@  main(int argc, char *argv[])
 		}
 	}
 
-	if ((argc - optind) > (MAX_ARGV_SIZE - 6))
-		error(1, E2BIG, "Too many arguments to pass to weston");
-
-	if (wl.new_user)
-		wl.pw = getpwnam(wl.new_user);
-	else
-		wl.pw = getpwuid(getuid());
-	if (wl.pw == NULL)
-		error(1, errno, "failed to get username");
-
-	if (!weston_launch_allowed(&wl))
-		error(1, 0, "Permission denied. You should either:\n"
-#ifdef HAVE_SYSTEMD_LOGIN
-		      " - run from an active and local (systemd) session.\n"
-#else
-		      " - enable systemd session support for weston-launch.\n"
-#endif
-		      " - or add yourself to the 'weston-launch' group.");
-
-	if (setup_tty(&wl, tty) < 0)
-		exit(EXIT_FAILURE);
-
-	if (wl.new_user && setup_pam(&wl) < 0)
-		exit(EXIT_FAILURE);
-
-	if (setup_launcher_socket(&wl) < 0)
-		exit(EXIT_FAILURE);
-
-	if (setup_signals(&wl) < 0)
+	wl = weston_launcher_create(new_user, tty, verbose);
+	if (wl == NULL)
 		exit(EXIT_FAILURE);
 
-	wl.child = fork();
-	if (wl.child == -1) {
-		error(1, errno, "fork failed");
-		exit(EXIT_FAILURE);
-	}
-
-	if (wl.child == 0)
-		launch_compositor(&wl, argc - optind, argv + optind);
+	ret = weston_launcher_run_compositor(wl, BINDIR "/weston",
+					     argc - optind, argv + optind);
 
-	close(wl.sock[1]);
-	if (wl.tty != STDIN_FILENO)
-		close(wl.tty);
-
-	while (1) {
-		struct pollfd fds[2];
-		int n;
-
-		fds[0].fd = wl.sock[0];
-		fds[0].events = POLLIN;
-		fds[1].fd = wl.signalfd;
-		fds[1].events = POLLIN;
-
-		n = poll(fds, 2, -1);
-		if (n < 0)
-			error(0, errno, "poll failed");
-		if (fds[0].revents & POLLIN)
-			handle_socket_msg(&wl);
-		if (fds[1].revents)
-			handle_signal(&wl);
-	}
-
-	return 0;
+	weston_launcher_destroy(wl);
+	return ret;
 }
diff --git a/src/weston-launcher.c b/src/weston-launcher.c
new file mode 100644
index 0000000..72f02b4
--- /dev/null
+++ b/src/weston-launcher.c
@@ -0,0 +1,769 @@ 
+/*
+ * Copyright © 2012 Benjamin Franzke
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of the copyright holders not be used in
+ * advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission.  The copyright holders make
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+ * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <poll.h>
+#include <errno.h>
+
+#include <error.h>
+#include <getopt.h>
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <sys/signalfd.h>
+#include <signal.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#include <linux/vt.h>
+#include <linux/major.h>
+#include <linux/kd.h>
+
+#include <pwd.h>
+#include <grp.h>
+#include <security/pam_appl.h>
+
+#ifdef HAVE_SYSTEMD_LOGIN
+#include <systemd/sd-login.h>
+#endif
+
+#include <wayland-util.h>
+
+#include "weston-launch.h"
+#include "weston-launcher.h"
+#include "../shared/zalloc.h"
+
+#define DRM_MAJOR 226
+
+#ifndef KDSKBMUTE
+#define KDSKBMUTE	0x4B51
+#endif
+
+#ifndef EVIOCREVOKE
+#define EVIOCREVOKE _IOW('E', 0x91, int)
+#endif
+
+#define MAX_ARGV_SIZE 256
+
+#ifdef HAVE_LIBDRM
+
+#include <xf86drm.h>
+
+#else
+
+static inline int
+drmDropMaster(int drm_fd)
+{
+	return 0;
+}
+
+static inline int
+drmSetMaster(int drm_fd)
+{
+	return 0;
+}
+
+#endif
+
+struct weston_launcher {
+	struct pam_conv pc;
+	pam_handle_t *ph;
+	int tty;
+	int ttynr;
+	int sock[2];
+	int drm_fd;
+	int last_input_fd;
+	int kb_mode;
+	struct passwd *pw;
+
+	int signalfd;
+
+	pid_t child;
+	int verbose;
+	char *new_user;
+};
+
+union cmsg_data { unsigned char b[4]; int fd; };
+
+static gid_t *
+read_groups(void)
+{
+	int n;
+	gid_t *groups;
+	
+	n = getgroups(0, NULL);
+
+	if (n < 0) {
+		fprintf(stderr, "Unable to retrieve groups: %m\n");
+		return NULL;
+	}
+
+	groups = malloc(n * sizeof(gid_t));
+	if (!groups)
+		return NULL;
+
+	if (getgroups(n, groups) < 0) {
+		fprintf(stderr, "Unable to retrieve groups: %m\n");
+		free(groups);
+		return NULL;
+	}
+	return groups;
+}
+
+static bool
+weston_launch_allowed(struct weston_launcher *wl)
+{
+	struct group *gr;
+	gid_t *groups;
+	int i;
+#ifdef HAVE_SYSTEMD_LOGIN
+	char *session, *seat;
+	int err;
+#endif
+
+	if (getuid() == 0)
+		return true;
+
+	gr = getgrnam("weston-launch");
+	if (gr) {
+		groups = read_groups();
+		if (groups) {
+			for (i = 0; groups[i]; ++i) {
+				if (groups[i] == gr->gr_gid) {
+					free(groups);
+					return true;
+				}
+			}
+			free(groups);
+		}
+	}
+
+#ifdef HAVE_SYSTEMD_LOGIN
+	err = sd_pid_get_session(getpid(), &session);
+	if (err == 0 && session) {
+		if (sd_session_is_active(session) &&
+		    sd_session_get_seat(session, &seat) == 0) {
+			free(seat);
+			free(session);
+			return true;
+		}
+		free(session);
+	}
+#endif
+	
+	return false;
+}
+
+static int
+pam_conversation_fn(int msg_count,
+		    const struct pam_message **messages,
+		    struct pam_response **responses,
+		    void *user_data)
+{
+	return PAM_SUCCESS;
+}
+
+static int
+setup_pam(struct weston_launcher *wl)
+{
+	int err;
+
+	wl->pc.conv = pam_conversation_fn;
+	wl->pc.appdata_ptr = wl;
+
+	err = pam_start("login", wl->pw->pw_name, &wl->pc, &wl->ph);
+	if (err != PAM_SUCCESS) {
+		fprintf(stderr, "failed to start pam transaction: %d: %s\n",
+			err, pam_strerror(wl->ph, err));
+		return -1;
+	}
+
+	err = pam_set_item(wl->ph, PAM_TTY, ttyname(wl->tty));
+	if (err != PAM_SUCCESS) {
+		fprintf(stderr, "failed to set PAM_TTY item: %d: %s\n",
+			err, pam_strerror(wl->ph, err));
+		return -1;
+	}
+
+	err = pam_open_session(wl->ph, 0);
+	if (err != PAM_SUCCESS) {
+		fprintf(stderr, "failed to open pam session: %d: %s\n",
+			err, pam_strerror(wl->ph, err));
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+setup_launcher_socket(struct weston_launcher *wl)
+{
+	if (socketpair(AF_LOCAL, SOCK_SEQPACKET, 0, wl->sock) < 0)
+		error(1, errno, "socketpair failed");
+	
+	if (fcntl(wl->sock[0], F_SETFD, FD_CLOEXEC) < 0)
+		error(1, errno, "fcntl failed");
+
+	return 0;
+}
+
+static int
+setup_signals(struct weston_launcher *wl)
+{
+	int ret;
+	sigset_t mask;
+	struct sigaction sa;
+
+	memset(&sa, 0, sizeof sa);
+	sa.sa_handler = SIG_DFL;
+	sa.sa_flags = SA_NOCLDSTOP | SA_RESTART;
+	ret = sigaction(SIGCHLD, &sa, NULL);
+	assert(ret == 0);
+
+	sa.sa_handler = SIG_IGN;
+	sa.sa_flags = 0;
+	sigaction(SIGHUP, &sa, NULL);
+
+	ret = sigemptyset(&mask);
+	assert(ret == 0);
+	sigaddset(&mask, SIGCHLD);
+	sigaddset(&mask, SIGINT);
+	sigaddset(&mask, SIGTERM);
+	sigaddset(&mask, SIGUSR1);
+	sigaddset(&mask, SIGUSR2);
+	ret = sigprocmask(SIG_BLOCK, &mask, NULL);
+	assert(ret == 0);
+
+	wl->signalfd = signalfd(-1, &mask, SFD_NONBLOCK | SFD_CLOEXEC);
+	if (wl->signalfd < 0)
+		return -errno;
+
+	return 0;
+}
+
+static void
+setenv_fd(const char *env, int fd)
+{
+	char buf[32];
+
+	snprintf(buf, sizeof buf, "%d", fd);
+	setenv(env, buf, 1);
+}
+
+static int
+send_reply(struct weston_launcher *wl, int reply)
+{
+	int len;
+
+	do {
+		len = send(wl->sock[0], &reply, sizeof reply, 0);
+	} while (len < 0 && errno == EINTR);
+
+	return len;
+}
+
+static int
+handle_open(struct weston_launcher *wl, struct msghdr *msg, ssize_t len)
+{
+	int fd = -1, ret = -1;
+	char control[CMSG_SPACE(sizeof(fd))];
+	struct cmsghdr *cmsg;
+	struct stat s;
+	struct msghdr nmsg;
+	struct iovec iov;
+	struct weston_launcher_open *message;
+	union cmsg_data *data;
+
+	message = msg->msg_iov->iov_base;
+	if ((size_t)len < sizeof(*message))
+		goto err0;
+
+	/* Ensure path is null-terminated */
+	((char *) message)[len-1] = '\0';
+
+	fd = open(message->path, message->flags);
+	if (fd < 0) {
+		fprintf(stderr, "Error opening device %s: %m\n",
+			message->path);
+		goto err0;
+	}
+
+	if (fstat(fd, &s) < 0) {
+		close(fd);
+		fd = -1;
+		fprintf(stderr, "Failed to stat %s\n", message->path);
+		goto err0;
+	}
+
+	if (major(s.st_rdev) != INPUT_MAJOR &&
+	    major(s.st_rdev) != DRM_MAJOR) {
+		close(fd);
+		fd = -1;
+		fprintf(stderr, "Device %s is not an input or drm device\n",
+			message->path);
+		goto err0;
+	}
+
+err0:
+	memset(&nmsg, 0, sizeof nmsg);
+	nmsg.msg_iov = &iov;
+	nmsg.msg_iovlen = 1;
+	if (fd != -1) {
+		nmsg.msg_control = control;
+		nmsg.msg_controllen = sizeof control;
+		cmsg = CMSG_FIRSTHDR(&nmsg);
+		cmsg->cmsg_level = SOL_SOCKET;
+		cmsg->cmsg_type = SCM_RIGHTS;
+		cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
+		data = (union cmsg_data *) CMSG_DATA(cmsg);
+		data->fd = fd;
+		nmsg.msg_controllen = cmsg->cmsg_len;
+		ret = 0;
+	}
+	iov.iov_base = &ret;
+	iov.iov_len = sizeof ret;
+
+	if (wl->verbose)
+		fprintf(stderr, "weston-launch: opened %s: ret: %d, fd: %d\n",
+			message->path, ret, fd);
+	do {
+		len = sendmsg(wl->sock[0], &nmsg, 0);
+	} while (len < 0 && errno == EINTR);
+
+	if (len < 0)
+		return -1;
+
+	if (fd != -1 && major(s.st_rdev) == DRM_MAJOR)
+		wl->drm_fd = fd;
+	if (fd != -1 && major(s.st_rdev) == INPUT_MAJOR &&
+	    wl->last_input_fd < fd)
+		wl->last_input_fd = fd;
+
+	return 0;
+}
+
+static int
+handle_socket_msg(struct weston_launcher *wl)
+{
+	char control[CMSG_SPACE(sizeof(int))];
+	char buf[BUFSIZ];
+	struct msghdr msg;
+	struct iovec iov;
+	int ret = -1;
+	ssize_t len;
+	struct weston_launcher_message *message;
+
+	memset(&msg, 0, sizeof(msg));
+	iov.iov_base = buf;
+	iov.iov_len  = sizeof buf;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = control;
+	msg.msg_controllen = sizeof control;
+
+	do {
+		len = recvmsg(wl->sock[0], &msg, 0);
+	} while (len < 0 && errno == EINTR);
+
+	if (len < 1)
+		return -1;
+
+	message = (void *) buf;
+	switch (message->opcode) {
+	case WESTON_LAUNCHER_OPEN:
+		ret = handle_open(wl, &msg, len);
+		break;
+	}
+
+	return ret;
+}
+
+static void
+quit(struct weston_launcher *wl, int status)
+{
+	struct vt_mode mode = { 0 };
+	int err;
+
+	close(wl->signalfd);
+	close(wl->sock[0]);
+
+	if (wl->new_user) {
+		err = pam_close_session(wl->ph, 0);
+		if (err)
+			fprintf(stderr, "pam_close_session failed: %d: %s\n",
+				err, pam_strerror(wl->ph, err));
+		pam_end(wl->ph, err);
+	}
+
+	if (ioctl(wl->tty, KDSKBMUTE, 0) &&
+	    ioctl(wl->tty, KDSKBMODE, wl->kb_mode))
+		fprintf(stderr, "failed to restore keyboard mode: %m\n");
+
+	if (ioctl(wl->tty, KDSETMODE, KD_TEXT))
+		fprintf(stderr, "failed to set KD_TEXT mode on tty: %m\n");
+
+	/* We have to drop master before we switch the VT back in
+	 * VT_AUTO, so we don't risk switching to a VT with another
+	 * display server, that will then fail to set drm master. */
+	drmDropMaster(wl->drm_fd);
+
+	mode.mode = VT_AUTO;
+	if (ioctl(wl->tty, VT_SETMODE, &mode) < 0)
+		fprintf(stderr, "could not reset vt handling\n");
+
+	exit(status);
+}
+
+static void
+close_input_fds(struct weston_launcher *wl)
+{
+	struct stat s;
+	int fd;
+
+	for (fd = 3; fd <= wl->last_input_fd; fd++) {
+		if (fstat(fd, &s) == 0 && major(s.st_rdev) == INPUT_MAJOR) {
+			/* EVIOCREVOKE may fail if the kernel doesn't
+			 * support it, but all we can do is ignore it. */
+			ioctl(fd, EVIOCREVOKE, 0);
+			close(fd);
+		}
+	}
+}
+
+static int
+handle_signal(struct weston_launcher *wl)
+{
+	struct signalfd_siginfo sig;
+	int pid, status, ret;
+
+	if (read(wl->signalfd, &sig, sizeof sig) != sizeof sig) {
+		error(0, errno, "reading signalfd failed");
+		return -1;
+	}
+
+	switch (sig.ssi_signo) {
+	case SIGCHLD:
+		pid = waitpid(-1, &status, 0);
+		if (pid == wl->child) {
+			wl->child = 0;
+			if (WIFEXITED(status))
+				ret = WEXITSTATUS(status);
+			else if (WIFSIGNALED(status))
+				/*
+				 * If weston dies because of signal N, we
+				 * return 10+N. This is distinct from
+				 * weston-launch dying because of a signal
+				 * (128+N).
+				 */
+				ret = 10 + WTERMSIG(status);
+			else
+				ret = 0;
+			quit(wl, ret);
+		}
+		break;
+	case SIGTERM:
+	case SIGINT:
+		if (wl->child)
+			kill(wl->child, sig.ssi_signo);
+		break;
+	case SIGUSR1:
+		send_reply(wl, WESTON_LAUNCHER_DEACTIVATE);
+		close_input_fds(wl);
+		drmDropMaster(wl->drm_fd);
+		ioctl(wl->tty, VT_RELDISP, 1);
+		break;
+	case SIGUSR2:
+		ioctl(wl->tty, VT_RELDISP, VT_ACKACQ);
+		drmSetMaster(wl->drm_fd);
+		send_reply(wl, WESTON_LAUNCHER_ACTIVATE);
+		break;
+	default:
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+setup_tty(struct weston_launcher *wl, const char *tty)
+{
+	struct stat buf;
+	struct vt_mode mode = { 0 };
+	char *t;
+
+	if (!wl->new_user) {
+		wl->tty = STDIN_FILENO;
+	} else if (tty) {
+		t = ttyname(STDIN_FILENO);
+		if (t && strcmp(t, tty) == 0)
+			wl->tty = STDIN_FILENO;
+		else
+			wl->tty = open(tty, O_RDWR | O_NOCTTY);
+	} else {
+		int tty0 = open("/dev/tty0", O_WRONLY | O_CLOEXEC);
+		char filename[16];
+
+		if (tty0 < 0)
+			error(1, errno, "could not open tty0");
+
+		if (ioctl(tty0, VT_OPENQRY, &wl->ttynr) < 0 || wl->ttynr == -1)
+			error(1, errno, "failed to find non-opened console"); 
+
+		snprintf(filename, sizeof filename, "/dev/tty%d", wl->ttynr);
+		wl->tty = open(filename, O_RDWR | O_NOCTTY);
+		close(tty0);
+	}
+
+	if (wl->tty < 0)
+		error(1, errno, "failed to open tty");
+
+	if (fstat(wl->tty, &buf) == -1 ||
+	    major(buf.st_rdev) != TTY_MAJOR || minor(buf.st_rdev) == 0)
+		error(1, 0, "weston-launch must be run from a virtual terminal");
+
+	if (tty) {
+		if (fstat(wl->tty, &buf) < 0)
+			error(1, errno, "stat %s failed", tty);
+
+		if (major(buf.st_rdev) != TTY_MAJOR)
+			error(1, 0, "invalid tty device: %s", tty);
+
+		wl->ttynr = minor(buf.st_rdev);
+	}
+
+	if (ioctl(wl->tty, KDGKBMODE, &wl->kb_mode))
+		error(1, errno, "failed to get current keyboard mode: %m\n");
+
+	if (ioctl(wl->tty, KDSKBMUTE, 1) &&
+	    ioctl(wl->tty, KDSKBMODE, K_OFF))
+		error(1, errno, "failed to set K_OFF keyboard mode: %m\n");
+
+	if (ioctl(wl->tty, KDSETMODE, KD_GRAPHICS))
+		error(1, errno, "failed to set KD_GRAPHICS mode on tty: %m\n");
+
+	mode.mode = VT_PROCESS;
+	mode.relsig = SIGUSR1;
+	mode.acqsig = SIGUSR2;
+	if (ioctl(wl->tty, VT_SETMODE, &mode) < 0)
+		error(1, errno, "failed to take control of vt handling\n");
+
+	return 0;
+}
+
+static void
+setup_session(struct weston_launcher *wl)
+{
+	char **env;
+	char *term;
+	int i;
+
+	if (wl->tty != STDIN_FILENO) {
+		if (setsid() < 0)
+			error(1, errno, "setsid failed");
+		if (ioctl(wl->tty, TIOCSCTTY, 0) < 0)
+			error(1, errno, "TIOCSCTTY failed - tty is in use");
+	}
+
+	term = getenv("TERM");
+	clearenv();
+	if (term)
+		setenv("TERM", term, 1);
+	setenv("USER", wl->pw->pw_name, 1);
+	setenv("LOGNAME", wl->pw->pw_name, 1);
+	setenv("HOME", wl->pw->pw_dir, 1);
+	setenv("SHELL", wl->pw->pw_shell, 1);
+
+	env = pam_getenvlist(wl->ph);
+	if (env) {
+		for (i = 0; env[i]; ++i) {
+			if (putenv(env[i]) < 0)
+				error(0, 0, "putenv %s failed", env[i]);
+		}
+		free(env);
+	}
+}
+
+static void
+drop_privileges(struct weston_launcher *wl)
+{
+	if (setgid(wl->pw->pw_gid) < 0 ||
+#ifdef HAVE_INITGROUPS
+	    initgroups(wl->pw->pw_name, wl->pw->pw_gid) < 0 ||
+#endif
+	    setuid(wl->pw->pw_uid) < 0)
+		error(1, errno, "dropping privileges failed");
+}
+
+static void
+launch_compositor(struct weston_launcher *wl, const char *path,
+		  int argc, char *argv[])
+{
+	char *child_argv[MAX_ARGV_SIZE];
+	sigset_t mask;
+	int i;
+	char *bin = basename(path);
+
+	if (wl->verbose)
+		printf("weston-launch: spawned %s with pid: %d\n", bin, getpid());
+	if (wl->new_user)
+		setup_session(wl);
+
+	if (geteuid() == 0)
+		drop_privileges(wl);
+
+	setenv_fd("WESTON_TTY_FD", wl->tty);
+	setenv_fd("WESTON_LAUNCHER_SOCK", wl->sock[1]);
+
+	unsetenv("DISPLAY");
+
+	/* Do not give our signal mask to the new process. */
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGTERM);
+	sigaddset(&mask, SIGCHLD);
+	sigaddset(&mask, SIGINT);
+	sigprocmask(SIG_UNBLOCK, &mask, NULL);
+
+	child_argv[0] = "/bin/sh";
+	child_argv[1] = "-l";
+	child_argv[2] = "-c";
+	child_argv[3] = strcat(zalloc(strlen(path) + 6), path);
+	strcat(child_argv[3], " \"$@\"");
+	printf("%s %s\n",child_argv[3],bin);
+	child_argv[4] = bin;
+	for (i = 0; i < argc; ++i)
+		child_argv[5 + i] = argv[i];
+	child_argv[5 + i] = NULL;
+
+	execv(child_argv[0], child_argv);
+	error(1, errno, "exec failed");
+}
+
+WL_EXPORT struct weston_launcher *
+weston_launcher_create(const char *new_user, const char *tty, int verbose)
+{
+	struct weston_launcher *wl;
+
+	wl = zalloc(sizeof *wl);
+	if (wl == NULL)
+		return NULL;
+
+	wl->verbose = verbose;
+
+	if (new_user) {
+		wl->new_user = strdup(new_user);
+		if (getuid() != 0)
+			error(1, 0, "Permission denied. Setting the user is allowed for root only");
+	}
+
+	if (wl->new_user)
+		wl->pw = getpwnam(wl->new_user);
+	else
+		wl->pw = getpwuid(getuid());
+	if (wl->pw == NULL)
+		error(1, errno, "failed to get username");
+
+	if (!weston_launch_allowed(wl))
+		error(1, 0, "Permission denied. You should either:\n"
+#ifdef HAVE_SYSTEMD_LOGIN
+		      " - run from an active and local (systemd) session.\n"
+#else
+		      " - enable systemd session support for weston-launch.\n"
+#endif
+		      " - or add yourself to the 'weston-launch' group.");
+
+	if (setup_tty(wl, tty) < 0)
+		goto error_out;
+
+	if (wl->new_user && setup_pam(wl) < 0)
+		goto error_out;
+
+	if (setup_launcher_socket(wl) < 0)
+		goto error_out;
+
+	if (setup_signals(wl) < 0)
+		goto error_out;
+
+	return wl;
+
+error_out:
+	free(wl);
+	return NULL;
+}
+
+WL_EXPORT int
+weston_launcher_run_compositor(struct weston_launcher *wl,
+			       const char *compositor_path,
+			       int argc, char *argv[])
+{
+	if (argc > (MAX_ARGV_SIZE - 6))
+		error(1, E2BIG, "Too many arguments to pass to the compositor");
+
+	wl->child = fork();
+	if (wl->child == -1) {
+		error(1, errno, "fork failed");
+		return -1;
+	}
+
+	if (wl->child == 0)
+		launch_compositor(wl, compositor_path, argc, argv);
+
+	close(wl->sock[1]);
+	if (wl->tty != STDIN_FILENO)
+		close(wl->tty);
+
+	while (1) {
+		struct pollfd fds[2];
+		int n;
+
+		fds[0].fd = wl->sock[0];
+		fds[0].events = POLLIN;
+		fds[1].fd = wl->signalfd;
+		fds[1].events = POLLIN;
+
+		n = poll(fds, 2, -1);
+		if (n < 0)
+			error(0, errno, "poll failed");
+		if (fds[0].revents & POLLIN)
+			handle_socket_msg(wl);
+		if (fds[1].revents)
+			handle_signal(wl);
+	}
+
+	return 0;
+}
+
+WL_EXPORT void
+weston_launcher_destroy(struct weston_launcher *wl)
+{
+	if (wl->new_user)
+		free(wl->new_user);
+	free(wl);
+}
diff --git a/src/weston-launcher.h b/src/weston-launcher.h
new file mode 100644
index 0000000..bdfb3ac
--- /dev/null
+++ b/src/weston-launcher.h
@@ -0,0 +1,45 @@ 
+/*
+ * Copyright © 2014 Giulio Camuffo
+ *
+ * Permission to use, copy, modify, distribute, and sell this software and
+ * its documentation for any purpose is hereby granted without fee, provided
+ * that the above copyright notice appear in all copies and that both that
+ * copyright notice and this permission notice appear in supporting
+ * documentation, and that the name of the copyright holders not be used in
+ * advertising or publicity pertaining to distribution of the software
+ * without specific, written prior permission.  The copyright holders make
+ * no representations about the suitability of this software for any
+ * purpose.  It is provided "as is" without express or implied warranty.
+ *
+ * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
+ * SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+ * RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+ * CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef _WESTON_LAUNCHER_H_
+#define _WESTON_LAUNCHER_H_
+
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
+struct weston_launcher;
+
+struct weston_launcher *
+weston_launcher_create(const char *new_user, const char *tty, int verbose);
+int
+weston_launcher_run_compositor(struct weston_launcher *wl,
+			       const char *compositor_path,
+			       int argc, char *argv[]);
+void
+weston_launcher_destroy(struct weston_launcher *wl);
+
+#ifdef  __cplusplus
+}
+#endif
+
+#endif