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-weston-launch.c b/src/launcher-weston-launch.c
new file mode 100644
index 0000000..09f671d
--- /dev/null
+++ b/src/launcher-weston-launch.c
@@ -0,0 +1,302 @@
+/*
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <errno.h>
+#include <signal.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+#include <sys/ioctl.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <linux/vt.h>
+#include <linux/kd.h>
+#include <linux/major.h>
+
+#include "compositor.h"
+#include "weston-launch.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
+
+
+union cmsg_data { unsigned char b[4]; int fd; };
+
+struct launcher_weston_launch {
+	struct weston_launcher base;
+	struct weston_compositor *compositor;
+	struct wl_event_loop *loop;
+	int fd;
+	struct wl_event_source *source;
+
+	int kb_mode, tty, drm_fd;
+	struct wl_event_source *vt_source;
+};
+
+static int
+launcher_weston_launch_open(struct weston_launcher *launcher_base,
+		     const char *path, int flags)
+{
+	struct launcher_weston_launch *launcher = wl_container_of(launcher_base, launcher, base);
+	int n, ret;
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	struct iovec iov;
+	union cmsg_data *data;
+	char control[CMSG_SPACE(sizeof data->fd)];
+	ssize_t len;
+	struct weston_launcher_open *message;
+
+	n = sizeof(*message) + strlen(path) + 1;
+	message = malloc(n);
+	if (!message)
+		return -1;
+
+	message->header.opcode = WESTON_LAUNCHER_OPEN;
+	message->flags = flags;
+	strcpy(message->path, path);
+
+	do {
+		len = send(launcher->fd, message, n, 0);
+	} while (len < 0 && errno == EINTR);
+	free(message);
+
+	memset(&msg, 0, sizeof msg);
+	iov.iov_base = &ret;
+	iov.iov_len = sizeof ret;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = control;
+	msg.msg_controllen = sizeof control;
+	
+	do {
+		len = recvmsg(launcher->fd, &msg, MSG_CMSG_CLOEXEC);
+	} while (len < 0 && errno == EINTR);
+
+	if (len != sizeof ret ||
+	    ret < 0)
+		return -1;
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	if (!cmsg ||
+	    cmsg->cmsg_level != SOL_SOCKET ||
+	    cmsg->cmsg_type != SCM_RIGHTS) {
+		fprintf(stderr, "invalid control message\n");
+		return -1;
+	}
+
+	data = (union cmsg_data *) CMSG_DATA(cmsg);
+	if (data->fd == -1) {
+		fprintf(stderr, "missing drm fd in socket request\n");
+		return -1;
+	}
+
+	return data->fd;
+}
+
+static void
+launcher_weston_launch_close(struct weston_launcher *launcher_base, int fd)
+{
+	close(fd);
+}
+
+static void
+launcher_weston_launch_restore(struct weston_launcher *launcher_base)
+{
+	struct launcher_weston_launch *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_weston_launch_data(int fd, uint32_t mask, void *data)
+{
+	struct launcher_weston_launch *launcher = data;
+	int len, ret;
+
+	if (mask & (WL_EVENT_HANGUP | WL_EVENT_ERROR)) {
+		weston_log("launcher socket closed, exiting\n");
+		/* Normally the weston-launch will reset the tty, but
+		 * in this case it died or something, so do it here so
+		 * we don't end up with a stuck vt. */
+		launcher_weston_launch_restore(&launcher->base);
+		exit(-1);
+	}
+
+	do {
+		len = recv(launcher->fd, &ret, sizeof ret, 0);
+	} while (len < 0 && errno == EINTR);
+
+	switch (ret) {
+	case WESTON_LAUNCHER_ACTIVATE:
+		launcher->compositor->session_active = 1;
+		wl_signal_emit(&launcher->compositor->session_signal,
+			       launcher->compositor);
+		break;
+	case WESTON_LAUNCHER_DEACTIVATE:
+		launcher->compositor->session_active = 0;
+		wl_signal_emit(&launcher->compositor->session_signal,
+			       launcher->compositor);
+		break;
+	default:
+		weston_log("unexpected event from weston-launch\n");
+		break;
+	}
+
+	return 1;
+}
+
+static int
+launcher_weston_launch_activate_vt(struct weston_launcher *launcher_base, int vt)
+{
+	struct launcher_weston_launch *launcher = wl_container_of(launcher_base, launcher, base);
+	return ioctl(launcher->tty, VT_ACTIVATE, vt);
+}
+
+static int
+launcher_weston_launch_connect(struct weston_launcher **out, struct weston_compositor *compositor,
+			       int tty, const char *seat_id, bool sync_drm)
+{
+	struct launcher_weston_launch *launcher;
+	struct wl_event_loop *loop;
+
+	launcher = malloc(sizeof *launcher);
+	if (launcher == NULL)
+		return -ENOMEM;
+
+	launcher->base.iface = &launcher_weston_launch_iface;
+	* (struct launcher_weston_launch **) out = launcher;
+	launcher->compositor = compositor;
+	launcher->drm_fd = -1;
+	launcher->fd = weston_environment_get_fd("WESTON_LAUNCH_SOCK");
+	if (launcher->fd != -1) {
+		launcher->tty = weston_environment_get_fd("WESTON_TTY_FD");
+		/* We don't get a chance to read out the original kb
+		 * mode for the tty, so just hard code K_UNICODE here
+		 * in case we have to clean if weston-launch dies. */
+		launcher->kb_mode = K_UNICODE;
+
+		loop = wl_display_get_event_loop(compositor->wl_display);
+		launcher->source = wl_event_loop_add_fd(loop, launcher->fd,
+							WL_EVENT_READABLE,
+							launcher_weston_launch_data,
+							launcher);
+		if (launcher->source == NULL) {
+			free(launcher);
+			return -ENOMEM;
+		}
+
+		return 0;
+	} else {
+		return -1;
+	}
+}
+
+static void
+launcher_weston_launch_destroy(struct weston_launcher *launcher_base)
+{
+	struct launcher_weston_launch *launcher = wl_container_of(launcher_base, launcher, base);
+
+	if (launcher->fd != -1) {
+		close(launcher->fd);
+		wl_event_source_remove(launcher->source);
+	} else {
+		launcher_weston_launch_restore(&launcher->base);
+		wl_event_source_remove(launcher->vt_source);
+	}
+
+	if (launcher->tty >= 0)
+		close(launcher->tty);
+
+	free(launcher);
+}
+
+struct launcher_interface launcher_weston_launch_iface = {
+	launcher_weston_launch_connect,
+	launcher_weston_launch_destroy,
+	launcher_weston_launch_open,
+	launcher_weston_launch_close,
+	launcher_weston_launch_activate_vt,
+	launcher_weston_launch_restore,
+};