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-util.c b/src/launcher-util.c
index dc02dff..e1beef6 100644
--- a/src/launcher-util.c
+++ b/src/launcher-util.c
@@ -26,440 +26,66 @@
 
 #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 "launcher-util.h"
-#include "launcher-logind.h"
-#include "weston-launch.h"
+#include "launcher-impl.h"
 
-#define DRM_MAJOR 226
+#include <unistd.h>
 
-#ifndef KDSKBMUTE
-#define KDSKBMUTE	0x4B51
+static struct launcher_interface *ifaces[] = {
+#ifdef HAVE_SYSTEMD_LOGIN
+	&launcher_logind_iface,
 #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 weston_launcher {
-	struct weston_compositor *compositor;
-	struct weston_logind *logind;
-	struct wl_event_loop *loop;
-	int fd;
-	struct wl_event_source *source;
-
-	int kb_mode, tty, drm_fd;
-	struct wl_event_source *vt_source;
+	&launcher_weston_launch_iface,
+	&launcher_direct_iface,
+	NULL,
 };
 
-int
-weston_launcher_open(struct weston_launcher *launcher,
-		     const char *path, int flags)
-{
-	int n, fd, ret = -1;
-	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;
-	struct stat s;
-
-	/* We really don't want to be leaking fds to child processes so
-	 * we force this flag here.  If someone comes up with a legitimate
-	 * reason to not CLOEXEC they'll need to unset the flag manually.
-	 */
-	flags |= O_CLOEXEC;
-
-	if (launcher->logind)
-		return weston_logind_open(launcher->logind, path, flags);
-
-	if (launcher->fd == -1) {
-		fd = open(path, flags);
-		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;
-	}
-
-	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;
-}
-
-void
-weston_launcher_close(struct weston_launcher *launcher, int fd)
-{
-	if (launcher->logind)
-		weston_logind_close(launcher->logind, fd);
-
-	close(fd);
-}
-
-void
-weston_launcher_restore(struct weston_launcher *launcher)
-{
-	struct vt_mode mode = { 0 };
-
-	if (launcher->logind)
-		return weston_logind_restore(launcher->logind);
-
-	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
-weston_launcher_data(int fd, uint32_t mask, void *data)
-{
-	struct weston_launcher *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. */
-		weston_launcher_restore(launcher);
-		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
-vt_handler(int signal_number, void *data)
-{
-	struct weston_launcher *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 weston_launcher *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;
-}
-
-int
-weston_launcher_activate_vt(struct weston_launcher *launcher, int vt)
-{
-	if (launcher->logind)
-		return weston_logind_activate_vt(launcher->logind, vt);
-
-	return ioctl(launcher->tty, VT_ACTIVATE, vt);
-}
-
-struct weston_launcher *
+WL_EXPORT struct weston_launcher *
 weston_launcher_connect(struct weston_compositor *compositor, int tty,
 			const char *seat_id, bool sync_drm)
 {
-	struct weston_launcher *launcher;
-	struct wl_event_loop *loop;
-	int r;
+	struct launcher_interface **it;
 
-	launcher = malloc(sizeof *launcher);
-	if (launcher == NULL)
-		return NULL;
+	for (it = ifaces; *it != NULL; it++) {
+		struct launcher_interface *iface = *it;
+		struct weston_launcher *launcher;
 
-	launcher->logind = NULL;
-	launcher->compositor = compositor;
-	launcher->drm_fd = -1;
-	launcher->fd = weston_environment_get_fd("WESTON_LAUNCHER_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,
-							weston_launcher_data,
-							launcher);
-		if (launcher->source == NULL) {
-			free(launcher);
-			return NULL;
-		}
-	} else {
-		r = weston_logind_connect(&launcher->logind, compositor,
-					  seat_id, tty, sync_drm);
-		if (r < 0) {
-			launcher->logind = NULL;
-			if (geteuid() == 0) {
-				if (setup_tty(launcher, tty) == -1) {
-					free(launcher);
-					return NULL;
-				}
-			} else {
-				free(launcher);
-				return NULL;
-			}
-		}
+		if (iface->connect(&launcher, compositor, tty, seat_id, sync_drm) == 0)
+			return launcher;
 	}
 
-	return launcher;
+	return NULL;
 }
 
-void
+WL_EXPORT void
 weston_launcher_destroy(struct weston_launcher *launcher)
 {
-	if (launcher->logind) {
-		weston_logind_destroy(launcher->logind);
-	} else if (launcher->fd != -1) {
-		close(launcher->fd);
-		wl_event_source_remove(launcher->source);
-	} else {
-		weston_launcher_restore(launcher);
-		wl_event_source_remove(launcher->vt_source);
-	}
+	launcher->iface->destroy(launcher);
+}
 
-	if (launcher->tty >= 0)
-		close(launcher->tty);
+WL_EXPORT int
+weston_launcher_open(struct weston_launcher *launcher,
+		     const char *path, int flags)
+{
+	return launcher->iface->open(launcher, path, flags);
+}
 
-	free(launcher);
+WL_EXPORT void
+weston_launcher_close(struct weston_launcher *launcher, int fd)
+{
+	launcher->iface->close(launcher, fd);
+}
+
+WL_EXPORT int
+weston_launcher_activate_vt(struct weston_launcher *launcher, int vt)
+{
+	return launcher->iface->activate_vt(launcher, vt);
+}
+
+WL_EXPORT void
+weston_launcher_restore(struct weston_launcher *launcher)
+{
+	launcher->iface->restore(launcher);
 }