af-packet: use mmap capture by default

Update the code to use mmap capture by default even in unset in
configuration file. mmap capture is now be turned off by using
explicitely 'use-mmap: no' in configuration.

src/runmode-af-packet.c

@@ -216,12 +216,17 @@ void *ParseAFPConfig(const char *iface)
         }
     }
 
-    (void)ConfGetChildValueBoolWithDefault(if_root, if_default, "use-mmap", (int *)&boolval);
-    if (boolval) {
-        SCLogInfo("Enabling mmaped capture on iface %s",
-                aconf->iface);
+    if (ConfGetChildValueBoolWithDefault(if_root, if_default, "use-mmap", (int *)&boolval) == 1) {
+        if (boolval) {
+            aconf->flags |= AFP_RING_MODE;
+        } else {
+            SCLogInfo("Disabling mmaped capture on iface %s",
+                    aconf->iface);
+        }
+    } else {
         aconf->flags |= AFP_RING_MODE;
     }
+
     (void)ConfGetChildValueBoolWithDefault(if_root, if_default, "mmap-locked", (int *)&boolval);
     if (boolval) {
         SCLogInfo("Enabling locked memory for mmap on iface %s",

suricata.yaml.in

@@ -525,7 +525,7 @@ af-packet:
   # Put default values here
   - interface: default
     #threads: auto
-    #use-mmap: yes
+    #use-mmap: no
     #rollover: yes
     tpacket-v3: yes