MINOR: listener: add the "accept-netscaler-cip" option to the "bind" keyword
When NetScaler application switch is used as L3+ switch, informations
regarding the original IP and TCP headers are lost as a new TCP
connection is created between the NetScaler and the backend server.
NetScaler provides a feature to insert in the TCP data the original data
that can then be consumed by the backend server.
Specifications and documentations from NetScaler:
https://support.citrix.com/article/CTX205670
https://www.citrix.com/blogs/2016/04/25/how-to-enable-client-ip-in-tcpip-option-of-netscaler/
When CIP is enabled on the NetScaler, then a TCP packet is inserted just after
the TCP handshake. This is composed as:
- CIP magic number : 4 bytes
Both sender and receiver have to agree on a magic number so that
they both handle the incoming data as a NetScaler Client IP insertion
packet.
- Header length : 4 bytes
Defines the length on the remaining data.
- IP header : >= 20 bytes if IPv4, 40 bytes if IPv6
Contains the header of the last IP packet sent by the client during TCP
handshake.
- TCP header : >= 20 bytes
Contains the header of the last TCP packet sent by the client during TCP
handshake.
diff --git a/doc/netscaler-client-ip-insertion-protocol.txt b/doc/netscaler-client-ip-insertion-protocol.txt
new file mode 100644
index 0000000..6f77f65
--- /dev/null
+++ b/doc/netscaler-client-ip-insertion-protocol.txt
@@ -0,0 +1,29 @@
+When NetScaler application switch is used as L3+ switch, informations
+regarding the original IP and TCP headers are lost as a new TCP
+connection is created between the NetScaler and the backend server.
+
+NetScaler provides a feature to insert in the TCP data the original data
+that can then be consumed by the backend server.
+
+Specifications and documentations from NetScaler:
+ https://support.citrix.com/article/CTX205670
+ https://www.citrix.com/blogs/2016/04/25/how-to-enable-client-ip-in-tcpip-option-of-netscaler/
+
+When CIP is enabled on the NetScaler, then a TCP packet is inserted just after
+the TCP handshake. This is composed as:
+
+ - CIP magic number : 4 bytes
+ Both sender and receiver have to agree on a magic number so that
+ they both handle the incoming data as a NetScaler Client IP insertion
+ packet.
+
+ - Header length : 4 bytes
+ Defines the length on the remaining data.
+
+ - IP header : >= 20 bytes if IPv4, 40 bytes if IPv6
+ Contains the header of the last IP packet sent by the client during TCP
+ handshake.
+
+ - TCP header : >= 20 bytes
+ Contains the header of the last TCP packet sent by the client during TCP
+ handshake.