feat: add proxy template origin field and implement socket utilities for log streaming

templates/http-block-path-traversal.yaml

@@ -0,0 +1,48 @@
+id: http-block-path-traversal
+name: Block path traversal
+protocol: http
+description: Stops common path traversal probes in path and query.
+category: http
+family: web-hardening
+tags:
+- path-traversal
+- web
+- block
+action: block
+summary: Stops common path traversal probes in path and query.
+behavior: Logs the matched traversal token and immediately drops the client connection
+  before the request reaches the upstream service.
+source_url: https://docs.mitmproxy.org/stable/addons/examples/
+code: |
+  import logging
+  from urllib.parse import unquote
+
+  from mitmproxy import http
+
+  TRAVERSAL_MARKERS = (
+      "../",
+      "..\\",
+      "%2e%2e",
+      "%252e%252e",
+      "..%2f",
+      "..%5c",
+  )
+
+
+  def request(flow: http.HTTPFlow) -> None:
+      raw_target = (
+          f"{flow.request.path}?{flow.request.query}"
+          if flow.request.query
+          else flow.request.path
+      )
+      normalized = unquote(unquote(raw_target)).lower()
+      for marker in TRAVERSAL_MARKERS:
+          if marker in normalized:
+              logging.warning(
+                  "[http-block-path-traversal] blocked %s %s from %s",
+                  flow.request.method,
+                  flow.request.pretty_url,
+                  flow.client_conn.peername,
+              )
+              flow.kill()
+              return