pcap-file: don't kill engine in unix socket mode

This patch updates the cleaning code to avoid to exit from suricata
in unix socket mode when a invalid pcap is given.

src/source-pcap-file.c

@@ -182,10 +182,16 @@ TmEcode ReceivePcapFileLoop(ThreadVars *tv, void *data, void *slot)
         if (unlikely(r == -1)) {
             SCLogError(SC_ERR_PCAP_DISPATCH, "error code %" PRId32 " %s",
                        r, pcap_geterr(pcap_g.pcap_handle));
-
+            if (! RunModeUnixSocketIsActive()) {
                 /* in the error state we just kill the engine */
                 EngineKill();
                 SCReturnInt(TM_ECODE_FAILED);
+            } else {
+                pcap_close(pcap_g.pcap_handle);
+                pcap_g.pcap_handle = NULL;
+                UnixSocketPcapFile(TM_ECODE_DONE);
+                SCReturnInt(TM_ECODE_DONE);
+            }
         } else if (unlikely(r == 0)) {
             SCLogInfo("pcap file end of file reached (pcap err code %" PRId32 ")", r);
             if (! RunModeUnixSocketIsActive()) {
@@ -199,8 +205,15 @@ TmEcode ReceivePcapFileLoop(ThreadVars *tv, void *data, void *slot)
             break;
         } else if (ptv->cb_result == TM_ECODE_FAILED) {
             SCLogError(SC_ERR_PCAP_DISPATCH, "Pcap callback PcapFileCallbackLoop failed");
+            if (! RunModeUnixSocketIsActive()) {
                 EngineKill();
                 SCReturnInt(TM_ECODE_FAILED);
+            } else {
+                pcap_close(pcap_g.pcap_handle);
+                pcap_g.pcap_handle = NULL;
+                UnixSocketPcapFile(TM_ECODE_DONE);
+                SCReturnInt(TM_ECODE_DONE);
+            }
         }
         SCPerfSyncCountersIfSignalled(tv, 0);
     }