4 files changed, 29 insertions, 1 deletions

diff --git a/lib/utils_base.c b/lib/utils_base.c
index db21ea15..da281286 100644
--- a/lib/utils_base.c
+++ b/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;
+}
diff --git a/lib/utils_base.h b/lib/utils_base.h
index b722d0ec..bda76595 100644
--- a/lib/utils_base.h
+++ b/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_ */
diff --git a/plugins-root/check_dhcp.c b/plugins-root/check_dhcp.c
index 8559d634..7cb2d300 100644
--- a/plugins-root/check_dhcp.c
+++ b/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"));
                 }
diff --git a/plugins-root/check_icmp.c b/plugins-root/check_icmp.c
index 7e3b00f3..7f9160c4 100644
--- a/plugins-root/check_icmp.c
+++ b/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;