new: introduce flag to explicitly do not detach/destroy TC hook and p…

…rogram at the exit

Signed-off-by: Leonardo Di Donato <[email protected]>

traffico.c

@@ -25,13 +25,16 @@ const char OPT_IFNAME_ARG[] = "IFNAME";
 const char OPT_ATTACH_LONG[] = "at";
 #define OPT_ATTACH_KEY 0x80
 const char OPT_ATTACH_ARG[] = "INGRESS|EGRESS";
+#define OPT_NO_CLEANUP_KEY 0x81
+const char OPT_NO_CLEANUP_LONG[] = "no-cleanup";
 
 const struct argp_option argp_opts[] = {
 
     {"OPTIONS", 0, 0, OPTION_DOC, 0, 0},
     {OPT_VERBOSE_LONG, OPT_VERBOSE_KEY, NULL, 0, "Verbose debug output", -1},
     {OPT_IFNAME_LONG, OPT_IFNAME_KEY, OPT_IFNAME_ARG, 0, "Interface to which to attach the filter\n(defaults to the default gateway interface)", 1},
     {OPT_ATTACH_LONG, OPT_ATTACH_KEY, OPT_ATTACH_ARG, 0, "Where to attach the filter (defaults to egress)", 1},
+    {OPT_NO_CLEANUP_LONG, OPT_NO_CLEANUP_KEY, NULL, 0, "Do not detach the TC hook and filter at the exit", 1},
     {"", 0, 0, OPTION_DOC, 0, 0},
     {0} // .
 
@@ -89,6 +92,9 @@ static error_t parse_cli(int key, char *arg, struct argp_state *state)
             argp_error(state, "option '--%s' requires one of the following values: %s", OPT_ATTACH_LONG, OPT_ATTACH_ARG);
         }
         break;
+    case OPT_NO_CLEANUP_KEY:
+        g_config.cleanup_on_exit = false;
+        break;
 
     // Arguments
     case ARGP_KEY_ARG:
@@ -205,22 +211,7 @@ int await(struct bpf_tc_hook hook, struct bpf_tc_opts opts)
     }
     fprintf(stdout, "\n");
 
-    // Detach the TC hook
-    int err;
-    char buf[100];
-    buf[sizeof(buf) - 1] = '\0';
-
-    opts.prog_fd = opts.prog_id = 0;
-    opts.flags = 0;
-    err = bpf_tc_detach(&hook, &opts);
-    if (err)
-    {
-        libbpf_strerror(err, buf, sizeof(buf));
-        log_erro("fail: detaching the TC eBPF program: %s\n", buf);
-    }
-    log_info("done: detaching the TC eBPF program\n");
-
-    return err < 0 ? -err : err;
+    return 0;
 }
 
 int main(int argc, char **argv)