Introduce weston-launch

weston-launch starts weston and provides mechanism
for weston to set/drop drm master, open a tty,
and read input devices without being root.

Execution is allowed for local-active sessions
or users in the group weston-launch.

1 files changed, 156 insertions, 0 deletions

diff --git a/src/launcher-util.c b/src/launcher-util.c
new file mode 100644
index 00000000..acfcc3ee
--- /dev/null
+++ b/src/launcher-util.c
@@ -0,0 +1,156 @@
+/*
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/uio.h>
+#include <fcntl.h>
+
+#include <xf86drm.h>
+
+#include "compositor.h"
+#include "launcher-util.h"
+#include "weston-launch.h"
+
+int
+weston_launcher_open(struct weston_compositor *compositor,
+		     const char *path, int flags)
+{
+	int sock = compositor->launcher_sock;
+	int fd, n, ret = -1;
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	struct iovec iov;
+	char control[CMSG_SPACE(sizeof fd)];
+	ssize_t len;
+	struct weston_launcher_open *message;
+
+	if (sock == -1)
+		return open(path, flags);
+
+	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(sock, message, n, 0);
+	} while (len < 0 && errno == EINTR);
+
+	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(sock, &msg, MSG_CMSG_CLOEXEC);
+	} while (len < 0 && errno == EINTR);
+
+	if (len != sizeof ret ||
+	    ret < 0)
+		goto out;
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	if (!cmsg ||
+	    cmsg->cmsg_level != SOL_SOCKET ||
+	    cmsg->cmsg_type != SCM_RIGHTS) {
+		fprintf(stderr, "invalid control message\n");
+		goto out;
+	}
+
+	fd = *(int *) CMSG_DATA(cmsg);
+	if (fd == -1) {
+		fprintf(stderr, "missing drm fd in socket request");
+		return -1;
+	}
+
+out:
+	free(message);
+	return ret < 0 ? ret : fd;
+}
+
+int
+weston_launcher_drm_set_master(struct weston_compositor *compositor,
+			       int drm_fd, char master)
+{
+	struct msghdr msg;
+	struct cmsghdr *cmsg;
+	struct iovec iov;
+	char control[CMSG_SPACE(sizeof(drm_fd))];
+	int ret;
+	ssize_t len;
+	struct weston_launcher_set_master message;
+
+	if (compositor->launcher_sock == -1) {
+		if (master)
+			return drmSetMaster(drm_fd);
+		else
+			return drmDropMaster(drm_fd);
+	}
+
+	memset(&msg, 0, sizeof msg);
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	msg.msg_control = control;
+	msg.msg_controllen = sizeof control;
+	cmsg = CMSG_FIRSTHDR(&msg);
+	cmsg->cmsg_level = SOL_SOCKET;
+	cmsg->cmsg_type = SCM_RIGHTS;
+	cmsg->cmsg_len = CMSG_LEN(sizeof(drm_fd));
+
+	*(int *) CMSG_DATA(cmsg) = drm_fd;
+	msg.msg_controllen = cmsg->cmsg_len;
+
+	iov.iov_base = &message;
+	iov.iov_len = sizeof message;
+
+	message.header.opcode = WESTON_LAUNCHER_DRM_SET_MASTER;
+	message.set_master = master;
+
+	do {
+		len = sendmsg(compositor->launcher_sock, &msg, 0);
+	} while (len < 0 && errno == EINTR);
+	if (len < 0)
+		return -1;
+
+	do {
+		len = recv(compositor->launcher_sock, &ret, sizeof ret, 0);
+	} while (len < 0 && errno == EINTR);
+	if (len < 0)
+		return -1;
+
+	return ret;
+}
+