detect/distance: improve value parsing and fix broken test

src/detect-content.c

@@ -2773,7 +2773,7 @@ static int SigTest69TestNegatedContent(void)
 
 static int SigTest70TestNegatedContent(void)
 {
-    return SigTestNegativeTestContent("alert tcp any any -> any any (content:\"one\"; content:!\"fourty\"; within:52; distance:45 sid:1;)", (uint8_t *)"one four nine fourteen twentythree thirtyfive fourtysix fiftysix");
+    return SigTestNegativeTestContent("alert tcp any any -> any any (content:\"one\"; content:!\"fourty\"; within:52; sid:1;)", (uint8_t *)"one four nine fourteen twentythree thirtyfive fourtysix fiftysix");
 }
 
 /** \test within and distance */

src/detect-distance.c

@@ -41,6 +41,7 @@
 
 #include "flow-var.h"
 
+#include "util-byte.h"
 #include "util-debug.h"
 #include "util-unittest.h"
 #include "detect-bytejump.h"
@@ -112,7 +113,11 @@ static int DetectDistanceSetup (DetectEngineCtx *de_ctx, Signature *s,
         cd->distance = ((DetectByteExtractData *)bed_sm->ctx)->local_id;
         cd->flags |= DETECT_CONTENT_DISTANCE_BE;
     } else {
-        cd->distance = strtol(str, NULL, 10);
+        if (ByteExtractStringInt32(&cd->distance, 0, 0, str) != (int)strlen(str)) {
+            SCLogError(SC_ERR_INVALID_SIGNATURE,
+                      "invalid value for distance: %s", str);
+            goto end;
+        }
     }
     cd->flags |= DETECT_CONTENT_DISTANCE;