initctl refactor, break out domain socket/client API

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/client.c

@@ -0,0 +1,97 @@
+/* External client API, using UNIX domain socket.
+ *
+ * Copyright (c) 2015-2017  Joachim Nilsson <troglobit@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include "client.h"
+
+static int sd = -1;
+
+int client_connect(void)
+{
+	struct sockaddr_un sun = {
+		.sun_family = AF_UNIX,
+		.sun_path   = INIT_SOCKET,
+	};
+
+	sd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (-1 == sd)
+		goto error;
+
+	if (connect(sd, (struct sockaddr*)&sun, sizeof(sun)) == -1) {
+		close(sd);
+		goto error;
+	}
+
+	return sd;
+error:
+	perror("Failed connecting to finit");
+	return -1;
+}
+
+int client_disconnect(void)
+{
+	int rc;
+
+	if (sd < 0) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	rc = close(sd);
+	sd = -1;
+
+	return rc;
+}
+
+int client_send(struct init_request *rq, ssize_t len)
+{
+	int sd, result = 255;
+
+	sd = client_connect();
+	if (-1 == sd)
+		return -1;
+
+	if (write(sd, rq, len) != len)
+		goto error;
+
+	if (read(sd, rq, len) != len)
+		goto error;
+
+	result = 0;
+	goto exit;
+error:
+	perror("Failed communicating with finit");
+exit:
+	client_disconnect();
+	return result;
+}
+
+/**
+ * Local Variables:
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */