From 948fdecf5264ffe283f0ed89751f96747bbdd659 Mon Sep 17 00:00:00 2001
From: jknapp <jknapp85@gmail.com>
Date: Sun, 24 Aug 2025 06:59:26 -0700
Subject: [PATCH] Update all backend templates with real IP forwarding and scan
 detection
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Extends the tarpit protection and real IP handling to all backend templates,
ensuring consistent behavior across different backend configurations.

Changes to all backend templates:
- Pass real client IP via X-CLIENT-IP and X-Real-IP headers
- Use var(txn.real_ip) which contains the actual client IP (from proxy headers or direct)
- Add scan attempt detection (400/401/403/404 errors)
- Track suspicious paths (admin panels, config files, etc.)
- Increment error counters for tarpit decisions

Updated templates:
- hap_backend.tpl: Main backend template
- hap_backend_http_check.tpl: Backend with HTTP health checks
- hap_backend_basic.tpl: Minimal backend configuration

Benefits:
- Backend applications receive the real client IP, not proxy IPs
- All backend types now contribute to scan detection
- Consistent security across different backend configurations
- Works seamlessly with Cloudflare and other CDNs

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
---
 templates/hap_backend.tpl            |  4 +++-
 templates/hap_backend_basic.tpl      | 22 ++++++++++++++++++++++
 templates/hap_backend_http_check.tpl | 22 +++++++++++++++++++++-
 3 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/templates/hap_backend.tpl b/templates/hap_backend.tpl
index cd6de57..27d4194 100644
--- a/templates/hap_backend.tpl
+++ b/templates/hap_backend.tpl
@@ -1,7 +1,9 @@
 
 backend {{ name }}-backend
     option forwardfor
-    http-request add-header X-CLIENT-IP %[src]
+    # Pass the real client IP to backend (from proxy headers or direct connection)
+    http-request add-header X-CLIENT-IP %[var(txn.real_ip)]
+    http-request set-header X-Real-IP %[var(txn.real_ip)]
     {% if ssl_enabled %}http-request set-header X-Forwarded-Proto https if { ssl_fc }{% endif %}
     
     # Define scanning attempt patterns
diff --git a/templates/hap_backend_basic.tpl b/templates/hap_backend_basic.tpl
index 257a108..5ef92d9 100644
--- a/templates/hap_backend_basic.tpl
+++ b/templates/hap_backend_basic.tpl
@@ -1,5 +1,27 @@
 
 backend {{ name }}-backend
+    option forwardfor
+    # Pass the real client IP to backend (from proxy headers or direct connection)
+    http-request add-header X-CLIENT-IP %[var(txn.real_ip)]
+    http-request set-header X-Real-IP %[var(txn.real_ip)]
+    
+    # Define scanning attempt patterns
+    acl is_404_error status 404
+    acl is_403_error status 403  
+    acl is_401_error status 401
+    acl is_400_error status 400
+    acl is_scan_attempt status 400 401 403 404
+    
+    # Additional suspicious patterns
+    acl suspicious_path path_reg -i \.(php|asp|aspx|jsp|cgi)$
+    acl suspicious_path path_reg -i /(wp-admin|phpmyadmin|admin|login|xmlrpc)
+    acl suspicious_path path_reg -i \.(env|git|svn|backup|bak|old)
+    
+    # Track scan attempts in the frontend stick table
+    # This increments the counter AFTER the backend responds with an error
+    # The frontend will check this counter on SUBSEQUENT requests
+    http-response sc-inc-gpc0(0) if is_scan_attempt
+    
     {% for server in servers %}
     server {{ server.server_name }} {{ server.server_address }}:{{ server.server_port }} {{ server.server_options }}
     {% endfor %}
diff --git a/templates/hap_backend_http_check.tpl b/templates/hap_backend_http_check.tpl
index e516029..339fc0a 100644
--- a/templates/hap_backend_http_check.tpl
+++ b/templates/hap_backend_http_check.tpl
@@ -2,8 +2,28 @@
 backend {{ name }}-backend
     option forwardfor
     option httpchk
-    http-request add-header X-CLIENT-IP %[src]
+    # Pass the real client IP to backend (from proxy headers or direct connection)
+    http-request add-header X-CLIENT-IP %[var(txn.real_ip)]
+    http-request set-header X-Real-IP %[var(txn.real_ip)]
     {% if ssl_enabled %}http-request set-header X-Forwarded-Proto https if { ssl_fc }{% endif %}
+    
+    # Define scanning attempt patterns
+    acl is_404_error status 404
+    acl is_403_error status 403  
+    acl is_401_error status 401
+    acl is_400_error status 400
+    acl is_scan_attempt status 400 401 403 404
+    
+    # Additional suspicious patterns
+    acl suspicious_path path_reg -i \.(php|asp|aspx|jsp|cgi)$
+    acl suspicious_path path_reg -i /(wp-admin|phpmyadmin|admin|login|xmlrpc)
+    acl suspicious_path path_reg -i \.(env|git|svn|backup|bak|old)
+    
+    # Track scan attempts in the frontend stick table
+    # This increments the counter AFTER the backend responds with an error
+    # The frontend will check this counter on SUBSEQUENT requests
+    http-response sc-inc-gpc0(0) if is_scan_attempt
+    
     {% for server in servers %}
     server {{ server.server_name }} {{ server.server_address }}:{{ server.server_port }} {{ server.server_options }}
     {% endfor %}