SimpleChatTC:SimpleProxy:UrlValidator module initial skeleton

Copy validate_url and build initial skeleton

tools/server/public_simplechat/local.tools/urlvalidator.py

@@ -0,0 +1,45 @@
+# Handle URL validation
+# by Humans for All
+
+import urllib.parse
+import re
+from dataclasses import dataclass
+
+
+gMe = {
+}
+
+
+@dataclass(frozen=True)
+class UrlVResponse:
+    """
+    Used to return result wrt urlreq helper below.
+    """
+    callOk: bool
+    statusCode: int
+    statusMsg: str = ""
+
+
+def validator_ok():
+    pass
+
+
+def validate_url(url: str, tag: str):
+    """
+    Implement a re based filter logic on the specified url.
+    """
+    tag=f"VU:{tag}"
+    if (not gMe.get('--allowed.domains')):
+        return UrlVResponse(False, 400, f"DBUG:{tag}:MissingAllowedDomains")
+    urlParts = urllib.parse.urlparse(url)
+    print(f"DBUG:ValidateUrl:{urlParts}, {urlParts.hostname}")
+    urlHName = urlParts.hostname
+    if not urlHName:
+        return UrlVResponse(False, 400, f"WARN:{tag}:Missing hostname in Url")
+    bMatched = False
+    for filter in gMe['--allowed.domains']:
+        if re.match(filter, urlHName):
+            bMatched = True
+    if not bMatched:
+        return UrlVResponse(False, 400, f"WARN:{tag}:requested hostname not allowed")
+    return UrlVResponse(True, 200)