Make write() and sendto() properly handle short writes and errors in ndhc.

Make ndhc write a pidfile.
Clean up defines.h and split out ifchd and ndhc specifics.

ifchd/ifchd-defines.h

@@ -1,12 +1,14 @@
-#define MAX_PATH_LENGTH 1024
+#ifndef IFCHD_DEFINES_H_
+#define IFCHD_DEFINES_H_
+
+#include "defines.h"
+
 #define PID_FILE_DEFAULT "/var/run/ifchd.pid"
 #define IFCHD_VERSION "0.8"
-
 #define COMM_SOCKET_PATH "ifchange"
 #define MAX_BUF 1024
-#define MAXLINE 1024
-
 #define SOCK_QUEUE 2
 #define CONN_TIMEOUT 60
-#define LINUX 1
+
+#endif /* IFCHD_DEFINES_H_ */
 

ifchd/ifchd.c

@@ -1,5 +1,5 @@
 /* ifchd.c - interface change daemon
- * Time-stamp: <2010-11-12 17:22:34 njk>
+ * Time-stamp: <2010-11-12 18:40:54 njk>
  *
  * (C) 2004-2010 Nicholas J. Kain <njkain at gmail dot com>
  *
@@ -39,7 +39,7 @@
 #define _GNU_SOURCE
 #include <getopt.h>
 
-#include "defines.h"
+#include "ifchd-defines.h"
 #include "malloc.h"
 #include "log.h"
 #include "chroot.h"

ifchd/linux.c

@@ -1,5 +1,5 @@
 /* linux.c - ifchd Linux-specific functions
- * Time-stamp: <2010-11-12 14:29:32 njk>
+ * Time-stamp: <2010-11-12 18:41:15 njk>
  *
  * (C) 2004-2010 Nicholas J. Kain <njkain at gmail dot com>
  *
@@ -37,7 +37,7 @@
 
 #include <errno.h>
 
-#include "defines.h"
+#include "ifchd-defines.h"
 #include "log.h"
 #include "strlist.h"
 #include "ifproto.h"