new-in-devel: document udp_accept_proxy & related

docs/alphaindexes/devel/rpccommands.md

@@ -378,6 +378,10 @@
 | **uac.reg_reload** | [uac](https://www.kamailio.org/docs/modules/6.1.x/modules/uac.html#uac.r.uac.reg_reload) |
 | **uac.reg_remove** | [uac](https://www.kamailio.org/docs/modules/6.1.x/modules/uac.html#uac.r.uac.reg_remove) |
 | **uac.reg_unregister** | [uac](https://www.kamailio.org/docs/modules/6.1.x/modules/uac.html#uac.r.uac.reg_unregister) |
+| **udp.proxy.dump** | [kex](https://www.kamailio.org/docs/modules/6.1.x/modules/kex.html#kex.r.udp.proxy.dump) |
+| **udp.proxy.stats** | [kex](https://www.kamailio.org/docs/modules/6.1.x/modules/kex.html#kex.r.udp.proxy.stats) |
+| **udp.proxy.clean** | [kex](https://www.kamailio.org/docs/modules/6.1.x/modules/kex.html#kex.r.udp.proxy.clean) |
+| **udp.proxy.flush** | [kex](https://www.kamailio.org/docs/modules/6.1.x/modules/kex.html#kex.r.udp.proxy.flush) |
 | **ul.add** | [usrloc](https://www.kamailio.org/docs/modules/6.1.x/modules/usrloc.html#usrloc.r.add) |
 | **ul.db_contacts** | [usrloc](https://www.kamailio.org/docs/modules/6.1.x/modules/usrloc.html#usrloc.r.db_contacts) |
 | **ul.db_expired_contacts** | [usrloc](https://www.kamailio.org/docs/modules/6.1.x/modules/usrloc.html#usrloc.r.db_expired_contacts) |

docs/cookbooks/devel/core.md

@@ -4394,6 +4394,35 @@ for normal UDP sockets.
 
 The parameter can be set at runtime (`core.udp4_raw_ttl`).
 
+### udp_accept_proxy
+
+Enables support for one or both of two UDP proxy protocols if set to non-zero.
+
+The bit value 1 enables support for version 2 of the [HAproxy
+protocol](https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt) (version
+1 does not support UDP). The bit value 2 enables support for the "simple" UDP
+proxy protocol (for example used by [Cloudflare
+Spectrum](https://developers.cloudflare.com/spectrum/reference/simple-proxy-protocol-header/)).
+The value 3 therefore enables support for both.
+
+When a UDP proxy protocol is in use, UDP packets are prepended with an
+additional header which includes information about the real source address and
+port. This header is then removed for further processing of the packet.
+
+The mappings between real source addresses and proxy addresses are kept in an
+internal hash table. For packets sent in the reverse direction, the matching
+proxy address is then looked up from the hash table in order to establish
+correct UDP flows.
+
+Entries are automatically removed from the hash table after 2 hours or not
+being used.
+
+The default value is zero to disable this support.
+
+``` c
+udp_accept_proxy=2
+```
+
 ## Blocklist Parameters
 
 ### dst_blocklist_expire

docs/features/new-in-devel.md

@@ -33,6 +33,12 @@ modules considered obsolete and not maintained have been moved to
 
 ### Parameters
 
+- `udp_accept_proxy` - add support for two UDP proxy protocols (HAproxy and "simple")
+- RPC command `udp.proxy.dump` to inspect the contents of the UDP proxy hash table
+- RPC command `udp.proxy.stats` to get an overview of the size of the UDP proxy hash table
+- RPC command `udp.proxy.clean` to remove expired entries from the UDP proxy hash table
+- RPC command `udp.proxy.flush` to remove all entries from the UDP proxy hash table
+
 ### Functions
 
 ### Memory Managers