System status message protocol

1 files changed, 134 insertions, 0 deletions

diff --git a/common/sysconf.c b/common/sysconf.c
new file mode 100644
index 00000000..fac3c06d
--- /dev/null
+++ b/common/sysconf.c
@@ -0,0 +1,134 @@
+/* systat.c
+
+   System status watcher...
+
+   !!!Boy, howdy, is this ever not guaranteed not to change!!! */
+
+/*
+ * Copyright (c) 1997 The Internet Software Consortium.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of The Internet Software Consortium nor the names
+ *    of its contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND
+ * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This software has been written for the Internet Software Consortium
+ * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie
+ * Enterprises.  To learn more about the Internet Software Consortium,
+ * see ``http://www.vix.com/isc''.  To learn more about Vixie
+ * Enterprises, see ``http://www.vix.com''.
+ */
+
+#ifndef lint
+static char copyright[] =
+"$Id: sysconf.c,v 1.1 1997/09/16 18:15:44 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+
+int systat_initialized;
+int systat_fd;
+
+void systat_startup (handler)
+	void (*handler) PROTO ((struct systat_header *, void *));
+{
+	struct sockaddr_un name;
+	static int once;
+
+	/* Only initialize systat once. */
+	if (systat_initialized)
+		error ("attempted to reinitialize systat protocol");
+	systat_initialized = 1;
+
+	systat_fd = socket (AF_UNIX, SOCK_STREAM, 0);
+	if (systat_fd < 0)
+		error ("unable to create systat socket: %m");
+
+	/* XXX for now... */
+	name.sun_family = PF_UNIX;
+	strcpy (name.sun_path, "/var/run/systat");
+	name.sun_len = ((sizeof name) - (sizeof name.sun_path) +
+			strlen (name.sun_path));
+
+	if (connect (systat_fd, (struct sockaddr *)&name, name.sun_len) < 0) {
+		if (!once)
+			warn ("can't connect to systat socket: %m");
+		once = 1;
+		close (systat_fd);
+		systat_initialized = 0;
+		add_timeout (cur_time + 60, systat_restart, handler);
+	} else
+		add_protocol ("systat", systat_fd, systat_message, handler);
+}
+
+void systat_restart (v)
+	void *v;
+{
+	void (*handler) PROTO ((struct systat_header *, void *)) = v;
+
+	systat_startup (handler);
+}
+
+void systat_message (proto)
+	struct protocol *proto;
+{
+	struct systat_header hdr;
+	int status;
+	char *buf;
+	void (*handler) PROTO ((struct systat_header *, void *));
+
+	status = read (systat_fd, &hdr, sizeof hdr);
+	if (status < 0) {
+		warn ("systat_message: %m");
+	      lose:
+		add_timeout (cur_time + 60, systat_restart, proto -> local);
+		remove_protocol (proto);
+		return;
+	}
+	if (status < sizeof (hdr)) {
+		warn ("systat_message: short message");
+		goto lose;
+	}
+
+	if (hdr.length) {
+		buf = malloc (hdr.length);
+		if (!buf)
+			error ("systat_message: can't buffer payload");
+		status = read (systat_fd, buf, hdr.length);
+		if (status < 0)
+			error ("systat_message payload read: %m");
+		if (status != hdr.length)
+			error ("systat_message payload: short read");
+	} else
+		buf = (char *)0;
+
+	/* Call the handler... */
+	if ((handler = proto -> local))
+		(*handler) (&hdr, buf);
+
+	if (buf)
+		free (buf);
+}