added functions to utils_base:

  np_check_if_root() - returns nonzero if geteuid()==0
  np_warn_if_not_root() - uses the above to print an informative warning
added uses of these functions to check_dhcp and check_icmp.


git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1718 f882894a-f735-0410-b71e-b25c423dba1c

lib/utils_base.c

@@ -228,3 +228,18 @@ char *np_escaped_string (const char *string) {
 	data[j] = '\0';
 	return data;
 }
+
+int np_check_if_root(void) { return (geteuid() == 0); }
+
+int np_warn_if_not_root(void) {
+	int status = np_check_if_root();
+	if(!status) {
+		printf(_("Warning: "));
+		printf(_("This plugin must be either run as root or setuid root.\n"));
+		printf(_("To run as root, you can use a tool like sudo.\n"));
+		printf(_("To set the setuid permissions, use the command:\n"));
+		// XXX could we use something like progname?
+		printf("\tchmod u+s yourpluginfile\n");
+	}
+	return status;
+}

lib/utils_base.h

@@ -43,4 +43,11 @@ void die (int, const char *, ...) __attribute__((noreturn,format(printf, 2, 3)))
 #define NP_RANGE_UNPARSEABLE 1
 #define NP_WARN_WITHIN_CRIT 2
 
+/* a simple check to see if we're running as root.  
+ * returns zero on failure, nonzero on success */
+int np_check_if_root(void);
+/* and a helpful wrapper around that.  it returns the same status
+ * code from the above function, in case it's helpful for testing */
+int np_warn_if_not_root(void);
+
 #endif /* _UTILS_BASE_ */

plugins-root/check_dhcp.c

@@ -250,10 +250,13 @@ int main(int argc, char **argv){
 	int dhcp_socket;
 	int result = STATE_UNKNOWN;
 
+	/* this plugin almost certainly needs root permissions. */
+	np_warn_if_not_root();
+	
 	setlocale (LC_ALL, "");
 	bindtextdomain (PACKAGE, LOCALEDIR);
 	textdomain (PACKAGE);
-	
+
 	if(process_arguments(argc,argv)!=OK){
 		usage4 (_("Could not parse arguments"));
 		}

plugins-root/check_icmp.c

@@ -372,6 +372,9 @@ main(int argc, char **argv)
 	int result;
 	struct rta_host *host;
 	
+	/* print a helpful error message if geteuid != 0 */
+	np_warn_if_not_root();
+
 	/* we only need to be setsuid when we get the sockets, so do
 	 * that before pointer magic (esp. on network data) */
 	icmp_sockerrno = udp_sockerrno = tcp_sockerrno = sockets = 0;