Test on the logging generation

Avoid to print the '%' character. This commit should be reverted
before production

Author: zimmerle

src/ngx_http_modsecurity_log.c

@@ -20,14 +20,51 @@
 
 #include "ngx_http_modsecurity_common.h"
 
+
+// FIXME: This function should be replaced, it is being used just for test.
+char *
+str_replace ( const char *string, const char *substr, const char *replacement ){
+  char *tok = NULL;
+  char *newstr = NULL;
+  char *oldstr = NULL;
+  char *head = NULL;
+
+  /* if either substr or replacement is NULL, duplicate string a let caller handle it */
+  if ( substr == NULL || replacement == NULL ) return strdup (string);
+  newstr = strdup (string);
+  head = newstr;
+  while ( (tok = strstr ( head, substr ))){
+    oldstr = newstr;
+    newstr = malloc ( strlen ( oldstr ) - strlen ( substr ) + strlen ( replacement ) + 1 );
+    /*failed to alloc mem, free old string and return NULL */
+    if ( newstr == NULL ){
+      free (oldstr);
+      return NULL;
+    }
+    memcpy ( newstr, oldstr, tok - oldstr );
+    memcpy ( newstr + (tok - oldstr), replacement, strlen ( replacement ) );
+    memcpy ( newstr + (tok - oldstr) + strlen( replacement ), tok + strlen ( substr ), strlen ( oldstr ) - strlen ( substr ) - ( tok - oldstr ) );
+    memset ( newstr + strlen ( oldstr ) - strlen ( substr ) + strlen ( replacement ) , 0, 1 );
+    /* move back head right after the last replacement */
+    head = newstr + (tok - oldstr) + strlen( replacement );
+    free (oldstr);
+  }
+  return newstr;
+}
+
+
 void
 ngx_http_modsecurity_log(void *log, const char* msg)
 {
+	char *new_log = NULL;
+
     if (log == NULL) {
         return;
     }
 
-    ngx_log_error(NGX_LOG_INFO, (ngx_log_t *)log, 0, msg);
+    new_log = str_replace(msg, "%", "_");
+    ngx_log_error(NGX_LOG_INFO, (ngx_log_t *)log, 0, new_log);
+    free(new_log);
 }