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

templates/http-block-command-injection-markers.yaml

@@ -0,0 +1,37 @@
+id: http-block-command-injection-markers
+name: Block command injection markers
+protocol: http
+description: Rejects obvious shell metacharacters and command-substitution markers.
+category: http
+family: web-hardening
+tags:
+- command-injection
+- web
+- block
+action: block
+summary: Rejects obvious shell metacharacters and command-substitution markers.
+behavior: Scans URL and body for shell-style injection markers, logs the first hit,
+  and drops the client connection.
+source_url: https://docs.mitmproxy.org/stable/addons/examples/
+code: |
+  import logging
+
+  from mitmproxy import http
+
+  BLOCKED_MARKERS = (";", "&&", "||", "$(", "`", "|sh", "|bash")
+
+
+  def request(flow: http.HTTPFlow) -> None:
+      body = flow.request.get_text(strict=False)
+      haystack = "\n".join(
+          [flow.request.pretty_url, body]
+      ).lower()
+      for marker in BLOCKED_MARKERS:
+          if marker in haystack:
+              logging.warning(
+                  "[http-block-command-injection-markers] blocked marker=%r url=%s",
+                  marker,
+                  flow.request.pretty_url,
+              )
+              flow.kill()
+              return