add DHT discovery service

This uses the BitTorrent 'Mainline' DHT in order to find peers.
It operates on the global PEX port, in order to allow exchanging network data
through double NAT. Only the IPv4 DHT is used at the moment.

Signed-off-by: Felix Fietkau <[email protected]>

Author: nbd168

.gitignore

@@ -7,3 +7,4 @@ CMakeFiles
 *.dylib
 unetd
 unet-tool
+unet-dht

CMakeLists.txt

@@ -36,6 +36,7 @@ ENDIF()
 
 IF(UBUS_SUPPORT)
   SET(SOURCES ${SOURCES} ubus.c)
+  SET(DHT_SOURCES ${DHT_SOURCES} udht-ubus.c)
   ADD_DEFINITIONS(-DUBUS_SUPPORT=1)
   FIND_LIBRARY(ubus ubus)
 ELSE()
@@ -51,7 +52,10 @@ TARGET_LINK_LIBRARIES(unetd unet ubox ${ubus} blobmsg_json ${libjson} ${nl} ${bp
 ADD_EXECUTABLE(unet-tool cli.c)
 TARGET_LINK_LIBRARIES(unet-tool unet blobmsg_json ${libjson} ubox)
 
-INSTALL(TARGETS unetd unet unet-tool
+ADD_EXECUTABLE(unet-dht dht.c udht.c ${DHT_SOURCES})
+TARGET_LINK_LIBRARIES(unet-dht unet ${ubus} ubox)
+
+INSTALL(TARGETS unetd unet unet-tool unet-dht
 	RUNTIME DESTINATION sbin
 	LIBRARY DESTINATION lib
 )