1 files changed, 144 insertions, 0 deletions
diff --git a/lib/plymouth-ctrl.c b/lib/plymouth-ctrl.c
new file mode 100644
index 0000000..2d3deda
--- /dev/null
+++ b/lib/plymouth-ctrl.c
@@ -0,0 +1,144 @@
+/*
+ * plymouth-ctrl.c	Simply communications with plymouthd
+ *			to avoid forked sub processes and/or
+ *			missed plymouth send commands tool
+ *			due a plymouthd replacement.
+ *
+ * Copyright (c) 2016 SUSE Linux GmbH, All rights reserved.
+ * Copyright (c) 2016 Werner Fink <werner@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (see the file COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ * Author: Werner Fink <werner@suse.de>
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdlib.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include "all-io.h"
+#include "c.h"
+#include "nls.h"
+#include "plymouth-ctrl.h"
+
+static int can_read(int fd, const long timeout)
+{
+	struct pollfd fds = {
+		.fd = fd,
+		.events = POLLIN|POLLPRI,
+		.revents = 0,
+	};
+	int ret;
+
+	do {
+		ret = poll(&fds, 1, timeout);
+	} while ((ret < 0) && (errno == EINTR));
+
+	return (ret == 1) && (fds.revents & (POLLIN|POLLPRI));
+}
+
+static int open_un_socket_and_connect(void)
+{
+	/* The abstract UNIX socket of plymouth */
+	struct sockaddr_un su = {
+		.sun_family = AF_UNIX,
+		.sun_path = PLYMOUTH_SOCKET_PATH,
+	};
+	const int one = 1;
+	int fd, ret;
+
+	fd = socket(PF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+	if (fd < 0) {
+		warnx(_("cannot open UNIX socket"));
+		goto err;
+	}
+
+	ret = setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
+	if (ret < 0) {
+		warnx(_("cannot set option for UNIX socket"));
+		close(fd);
+		fd = -1;
+		goto err;
+	}
+
+	/* Note, the abstract PLYMOUTH_SOCKET_PATH has a leading NULL byte */
+	ret = connect(fd, (struct sockaddr *) &su,
+		offsetof(struct sockaddr_un, sun_path) + 1 + strlen(su.sun_path+1));
+	if (ret < 0) {
+		if (errno != ECONNREFUSED)
+			warnx(_("cannot connect on UNIX socket"));
+		close(fd);
+		fd = -1;
+		goto err;
+	}
+err:
+	return fd;
+}
+
+int plymouth_command(int cmd, ...)
+{
+	uint8_t answer[2], command[2];
+	struct sigaction sp, op;
+	int fdsock = -1, ret = 0;
+
+	sigemptyset (&sp.sa_mask);
+	sp.sa_handler = SIG_IGN;
+	sp.sa_flags = SA_RESTART;
+	sigaction(SIGPIPE, &sp, &op);
+
+	/* The plymouthd does read at least two bytes. */
+	command[1] = '\0';
+	switch (cmd) {
+	case MAGIC_PING:
+		fdsock = open_un_socket_and_connect();
+		if (fdsock >= 0) {
+			command[0] = cmd;
+			write_all(fdsock, command, sizeof(command));
+		}
+		break;
+	case MAGIC_QUIT:
+		fdsock = open_un_socket_and_connect();
+		if (fdsock >= 0) {
+			command[0] = cmd;
+			write_all(fdsock, command, sizeof(command));
+		}
+		break;
+	default:
+		warnx(_("the plymouth request %c is not implemented"), cmd);
+	case '?':
+		goto err;
+	}
+
+	answer[0] = '\0';
+	if (fdsock >= 0) {
+		if (can_read(fdsock, 1000))
+			read_all(fdsock, (char *) &answer[0], sizeof(answer));
+		close(fdsock);
+	}
+	sigaction(SIGPIPE, &op, NULL);
+	ret = (answer[0] == ANSWER_ACK) ? 1 : 0;
+err:
+	return ret;
+}
+