cmake: Add libnatpmp optional package support

CMakeLists.txt

@@ -106,6 +106,11 @@ cmake_dependent_option(BUILD_WALLET_TOOL "Build bitcoin-wallet tool." ${BUILD_TE
 
 option(WITH_CCACHE "Attempt to use ccache for compiling." ON)
 
+option(WITH_NATPMP "Enable NAT-PMP." OFF)
+if(WITH_NATPMP)
+  find_package(NATPMP MODULE REQUIRED)
+endif()
+
 set(configure_warnings)
 
 include(CheckPIESupported)
@@ -278,6 +283,8 @@ if(ENABLE_WALLET)
   message("   - descriptor wallets (SQLite) ...... ${WITH_SQLITE}")
   message("   - legacy wallets (Berkeley DB) ..... ${WITH_BDB}")
 endif()
+message("  port mapping:")
+message("   - using NAT-PMP .................... ${WITH_NATPMP}")
 message("Tests:")
 message("  test_bitcoin ........................ ${BUILD_TESTS}")
 message("")

cmake/module/FindNATPMP.cmake

@@ -0,0 +1,32 @@
+# Copyright (c) 2023-present The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or https://opensource.org/license/mit/.
+
+find_path(NATPMP_INCLUDE_DIR
+  NAMES natpmp.h
+)
+
+find_library(NATPMP_LIBRARY
+  NAMES natpmp
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(NATPMP
+  REQUIRED_VARS NATPMP_LIBRARY NATPMP_INCLUDE_DIR
+)
+
+if(NATPMP_FOUND AND NOT TARGET NATPMP::NATPMP)
+  add_library(NATPMP::NATPMP UNKNOWN IMPORTED)
+  set_target_properties(NATPMP::NATPMP PROPERTIES
+    IMPORTED_LOCATION "${NATPMP_LIBRARY}"
+    INTERFACE_INCLUDE_DIRECTORIES "${NATPMP_INCLUDE_DIR}"
+  )
+  set_property(TARGET NATPMP::NATPMP PROPERTY
+    INTERFACE_COMPILE_DEFINITIONS USE_NATPMP=1 $<$<PLATFORM_ID:Windows>:NATPMP_STATICLIB>
+  )
+endif()
+
+mark_as_advanced(
+  NATPMP_INCLUDE_DIR
+  NATPMP_LIBRARY
+)

src/CMakeLists.txt

@@ -268,6 +268,7 @@ target_link_libraries(bitcoin_node
     Boost::headers
     $<TARGET_NAME_IF_EXISTS:libevent::libevent>
     $<TARGET_NAME_IF_EXISTS:libevent::pthreads>
+    $<TARGET_NAME_IF_EXISTS:NATPMP::NATPMP>
 )