Make the error message printed when an update of a table is rejected by the kernel
diff --git a/communication.c b/communication.c
index c45ebec..4b89a65 100644
--- a/communication.c
+++ b/communication.c
@@ -238,9 +238,13 @@
goto free_repl;
}
- ebt_print_error("The kernel doesn't support a certain ebtables"
- " extension, consider recompiling your kernel or insmod"
- " the extension");
+ ebt_print_error("Unable to update the kernel. Two possible causes:\n"
+ "1. Multiple ebtables programs were executing simultaneously. The ebtables\n"
+ " userspace tool doesn't by default support multiple ebtables programs running\n"
+ " concurrently. The ebtables option --concurrent or a tool like flock can be\n"
+ " used to support concurrent scripts that update the ebtables kernel tables.\n"
+ "2. The kernel doesn't support a certain ebtables extension, consider\n"
+ " recompiling your kernel or insmod the extension.\n");
free_repl:
if (repl) {
free(repl->entries);