launcher: Split out launcher implementations into three distinct ones

We now have a launcher interface and distinct implementations for
logind, weston-launch, and direct DRM, each in their own files.

This helps up clean up the spaghetti code into something that's
hopefully a bit more understood. There should be no functional
changes here.

Reviewed-by: Derek Foreman <derekf@osg.samsung.com>

update:  Dropped redundant free() in weston_launcher_destroy()
diff --git a/src/launcher-direct.c b/src/launcher-direct.c
new file mode 100644
index 0000000..29d9c28
--- /dev/null
+++ b/src/launcher-direct.c
@@ -0,0 +1,315 @@
+/*
+ * Copyright © 2012 Benjamin Franzke
+ * Copyright © 2013 Intel Corporation
+ *
+ * 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 "compositor.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <signal.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <linux/vt.h>
+#include <linux/kd.h>
+#include <linux/major.h>
+
+#include "launcher-impl.h"
+
+#define DRM_MAJOR 226
+
+#ifndef KDSKBMUTE
+#define KDSKBMUTE	0x4B51
+#endif
+
+#ifdef HAVE_LIBDRM
+
+#include <xf86drm.h>
+
+static inline int
+is_drm_master(int drm_fd)
+{
+	drm_magic_t magic;
+
+	return drmGetMagic(drm_fd, &magic) == 0 &&
+		drmAuthMagic(drm_fd, magic) == 0;
+}
+
+#else
+
+static inline int
+drmDropMaster(int drm_fd)
+{
+	return 0;
+}
+
+static inline int
+drmSetMaster(int drm_fd)
+{
+	return 0;
+}
+
+static inline int
+is_drm_master(int drm_fd)
+{
+	return 0;
+}
+
+#endif
+
+struct launcher_direct {
+	struct weston_launcher base;
+	struct weston_compositor *compositor;
+	int kb_mode, tty, drm_fd;
+	struct wl_event_source *vt_source;
+};
+
+static int
+vt_handler(int signal_number, void *data)
+{
+	struct launcher_direct *launcher = data;
+	struct weston_compositor *compositor = launcher->compositor;
+
+	if (compositor->session_active) {
+		compositor->session_active = 0;
+		wl_signal_emit(&compositor->session_signal, compositor);
+		drmDropMaster(launcher->drm_fd);
+		ioctl(launcher->tty, VT_RELDISP, 1);
+	} else {
+		ioctl(launcher->tty, VT_RELDISP, VT_ACKACQ);
+		drmSetMaster(launcher->drm_fd);
+		compositor->session_active = 1;
+		wl_signal_emit(&compositor->session_signal, compositor);
+	}
+
+	return 1;
+}
+
+static int
+setup_tty(struct launcher_direct *launcher, int tty)
+{
+	struct wl_event_loop *loop;
+	struct vt_mode mode = { 0 };
+	struct stat buf;
+	char tty_device[32] ="<stdin>";
+	int ret, kd_mode;
+
+	if (tty == 0) {
+		launcher->tty = dup(tty);
+		if (launcher->tty == -1) {
+			weston_log("couldn't dup stdin: %m\n");
+			return -1;
+		}
+	} else {
+		snprintf(tty_device, sizeof tty_device, "/dev/tty%d", tty);
+		launcher->tty = open(tty_device, O_RDWR | O_CLOEXEC);
+		if (launcher->tty == -1) {
+			weston_log("couldn't open tty %s: %m\n", tty_device);
+			return -1;
+		}
+	}
+
+	if (fstat(launcher->tty, &buf) == -1 ||
+	    major(buf.st_rdev) != TTY_MAJOR || minor(buf.st_rdev) == 0) {
+		weston_log("%s not a vt\n", tty_device);
+		weston_log("if running weston from ssh, "
+			   "use --tty to specify a tty\n");
+		goto err_close;
+	}
+
+	ret = ioctl(launcher->tty, KDGETMODE, &kd_mode);
+	if (ret) {
+		weston_log("failed to get VT mode: %m\n");
+		return -1;
+	}
+	if (kd_mode != KD_TEXT) {
+		weston_log("%s is already in graphics mode, "
+			   "is another display server running?\n", tty_device);
+		goto err_close;
+	}
+
+	ioctl(launcher->tty, VT_ACTIVATE, minor(buf.st_rdev));
+	ioctl(launcher->tty, VT_WAITACTIVE, minor(buf.st_rdev));
+
+	if (ioctl(launcher->tty, KDGKBMODE, &launcher->kb_mode)) {
+		weston_log("failed to read keyboard mode: %m\n");
+		goto err_close;
+	}
+
+	if (ioctl(launcher->tty, KDSKBMUTE, 1) &&
+	    ioctl(launcher->tty, KDSKBMODE, K_OFF)) {
+		weston_log("failed to set K_OFF keyboard mode: %m\n");
+		goto err_close;
+	}
+
+	ret = ioctl(launcher->tty, KDSETMODE, KD_GRAPHICS);
+	if (ret) {
+		weston_log("failed to set KD_GRAPHICS mode on tty: %m\n");
+		goto err_close;
+	}
+
+	/*
+	 * SIGRTMIN is used as global VT-acquire+release signal. Note that
+	 * SIGRT* must be tested on runtime, as their exact values are not
+	 * known at compile-time. POSIX requires 32 of them to be available.
+	 */
+	if (SIGRTMIN > SIGRTMAX) {
+		weston_log("not enough RT signals available: %u-%u\n",
+			   SIGRTMIN, SIGRTMAX);
+		ret = -EINVAL;
+		goto err_close;
+	}
+
+	mode.mode = VT_PROCESS;
+	mode.relsig = SIGRTMIN;
+	mode.acqsig = SIGRTMIN;
+	if (ioctl(launcher->tty, VT_SETMODE, &mode) < 0) {
+		weston_log("failed to take control of vt handling\n");
+		goto err_close;
+	}
+
+	loop = wl_display_get_event_loop(launcher->compositor->wl_display);
+	launcher->vt_source =
+		wl_event_loop_add_signal(loop, SIGRTMIN, vt_handler, launcher);
+	if (!launcher->vt_source)
+		goto err_close;
+
+	return 0;
+
+ err_close:
+	close(launcher->tty);
+	return -1;
+}
+
+static int
+launcher_direct_open(struct weston_launcher *launcher_base, const char *path, int flags)
+{
+	struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
+	struct stat s;
+	int fd;
+
+	fd = open(path, flags | O_CLOEXEC);
+	if (fd == -1)
+		return -1;
+
+	if (fstat(fd, &s) == -1) {
+		close(fd);
+		return -1;
+	}
+
+	if (major(s.st_rdev) == DRM_MAJOR) {
+		launcher->drm_fd = fd;
+		if (!is_drm_master(fd)) {
+			weston_log("drm fd not master\n");
+			close(fd);
+			return -1;
+		}
+	}
+
+	return fd;
+}
+
+static void
+launcher_direct_close(struct weston_launcher *launcher_base, int fd)
+{
+	close(fd);
+}
+
+static void
+launcher_direct_restore(struct weston_launcher *launcher_base)
+{
+	struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
+	struct vt_mode mode = { 0 };
+
+	if (ioctl(launcher->tty, KDSKBMUTE, 0) &&
+	    ioctl(launcher->tty, KDSKBMODE, launcher->kb_mode))
+		weston_log("failed to restore kb mode: %m\n");
+
+	if (ioctl(launcher->tty, KDSETMODE, KD_TEXT))
+		weston_log("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(launcher->drm_fd);
+
+	mode.mode = VT_AUTO;
+	if (ioctl(launcher->tty, VT_SETMODE, &mode) < 0)
+		weston_log("could not reset vt handling\n");
+}
+
+static int
+launcher_direct_activate_vt(struct weston_launcher *launcher_base, int vt)
+{
+	struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
+	return ioctl(launcher->tty, VT_ACTIVATE, vt);
+}
+
+static int
+launcher_direct_connect(struct weston_launcher **out, struct weston_compositor *compositor,
+			int tty, const char *seat_id, bool sync_drm)
+{
+	struct launcher_direct *launcher;
+
+	if (geteuid() != 0)
+		return -EINVAL;
+
+	launcher = zalloc(sizeof(*launcher));
+	if (launcher == NULL)
+		return -ENOMEM;
+
+	launcher->base.iface = &launcher_direct_iface;
+	launcher->compositor = compositor;
+
+	if (setup_tty(launcher, tty) == -1) {
+		free(launcher);
+		return -1;
+	}
+
+	* (struct launcher_direct **) out = launcher;
+	return 0;
+}
+
+static void
+launcher_direct_destroy(struct weston_launcher *launcher_base)
+{
+	struct launcher_direct *launcher = wl_container_of(launcher_base, launcher, base);
+
+	launcher_direct_restore(&launcher->base);
+	wl_event_source_remove(launcher->vt_source);
+
+	if (launcher->tty >= 0)
+		close(launcher->tty);
+
+	free(launcher);
+}
+
+struct launcher_interface launcher_direct_iface = {
+	launcher_direct_connect,
+	launcher_direct_destroy,
+	launcher_direct_open,
+	launcher_direct_close,
+	launcher_direct_activate_vt,
+	launcher_direct_restore,
+};