doc: Add libnatpmp stuff

depends/README.md

@@ -94,6 +94,7 @@ The following can be set when running make: `make FOO=bar`
 - `NO_BDB`: Don't download/build/cache BerkeleyDB
 - `NO_SQLITE`: Don't download/build/cache SQLite
 - `NO_UPNP`: Don't download/build/cache packages needed for enabling UPnP
+- `NO_NATPMP`: Don't download/build/cache packages needed for enabling NAT-PMP</dd>
 - `ALLOW_HOST_PACKAGES`: Packages that are missed in dependencies (due to `NO_*` option or
   build script logic) are searched for among the host system packages using
   `pkg-config`. It allows building with packages of other (newer) versions

doc/build-osx.md

@@ -19,7 +19,7 @@ Then install [Homebrew](https://brew.sh).
 
 ## Dependencies
 ```shell
-brew install automake libtool boost miniupnpc pkg-config python qt libevent qrencode
+brew install automake libtool boost miniupnpc libnatpmp pkg-config python qt libevent qrencode
 ```
 
 If you run into issues, check [Homebrew's troubleshooting page](https://docs.brew.sh/Troubleshooting).

doc/build-unix.md

@@ -41,6 +41,7 @@ Optional dependencies:
  Library     | Purpose          | Description
  ------------|------------------|----------------------
  miniupnpc   | UPnP Support     | Firewall-jumping support
+ libnatpmp   | NAT-PMP Support  | Firewall-jumping support
  libdb4.8    | Berkeley DB      | Optional, wallet storage (only needed when wallet enabled)
  qt          | GUI              | GUI toolkit (only needed when GUI enabled)
  libqrencode | QR codes in GUI  | Optional for generating QR codes (only needed when GUI enabled)
@@ -99,9 +100,9 @@ SQLite is required for the wallet:
 To build Bitcoin Core without wallet, see [*Disable-wallet mode*](/doc/build-unix.md#disable-wallet-mode)
 
 
-Optional (see `--with-miniupnpc` and `--enable-upnp-default`):
+Optional port mapping libraries (see: `--with-miniupnpc`, and `--enable-upnp-default`, `--with-natpmp`, `--enable-natpmp-default`):
 
-    sudo apt-get install libminiupnpc-dev
+    sudo apt install libminiupnpc-dev libnatpmp-dev
 
 ZMQ dependencies (provides ZMQ API):
 
@@ -133,9 +134,9 @@ Build requirements:
 
     sudo dnf install gcc-c++ libtool make autoconf automake libevent-devel boost-devel libdb4-devel libdb4-cxx-devel python3
 
-Optional (see `--with-miniupnpc` and `--enable-upnp-default`):
+Optional port mapping libraries (see: `--with-miniupnpc`, and `--enable-upnp-default`, `--with-natpmp`, `--enable-natpmp-default`):
 
-    sudo dnf install miniupnpc-devel
+    sudo dnf install miniupnpc-devel libnatpmp-devel
 
 ZMQ dependencies (provides ZMQ API):
 
@@ -158,18 +159,27 @@ Notes
 The release is built with GCC and then "strip bitcoind" to strip the debug
 symbols, which reduces the executable size by about 90%.
 
-
 miniupnpc
 ---------
 
 [miniupnpc](https://miniupnp.tuxfamily.org) may be used for UPnP port mapping.  It can be downloaded from [here](
 https://miniupnp.tuxfamily.org/files/).  UPnP support is compiled in and
-turned off by default.  See the configure options for upnp behavior desired:
+turned off by default.  See the configure options for UPnP behavior desired:
 
-	--without-miniupnpc      No UPnP support miniupnp not required
+	--without-miniupnpc      No UPnP support, miniupnp not required
 	--disable-upnp-default   (the default) UPnP support turned off by default at runtime
 	--enable-upnp-default    UPnP support turned on by default at runtime
 
+libnatpmp
+---------
+
+[libnatpmp](https://miniupnp.tuxfamily.org/libnatpmp.html) may be used for NAT-PMP port mapping. It can be downloaded
+from [here](https://miniupnp.tuxfamily.org/files/). NAT-PMP support is compiled in and
+turned off by default. See the configure options for NAT-PMP behavior desired:
+
+	--without-natpmp          No NAT-PMP support, libnatpmp not required
+	--disable-natpmp-default  (the default) NAT-PMP support turned off by default at runtime
+	--enable-natpmp-default   NAT-PMP support turned on by default at runtime
 
 Berkeley DB
 -----------

doc/dependencies.md

@@ -14,6 +14,7 @@ These are the dependencies currently used by Bitcoin Core. You can find instruct
 | GCC |  | [7+](https://gcc.gnu.org/) (C++17 support) |  |  |  |
 | HarfBuzz-NG |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) |
 | libevent | [2.1.11-stable](https://github.com/libevent/libevent/releases) | [2.0.21](https://github.com/bitcoin/bitcoin/pull/18676) | No |  |  |
+| libnatpmp | [20150609](https://miniupnp.tuxfamily.org/files) |  | No |  |  |
 | libpng |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) |
 | librsvg | |  |  |  |  |
 | MiniUPnPc | [2.0.20180203](https://miniupnp.tuxfamily.org/files) |  | No |  |  |
@@ -32,7 +33,8 @@ Controlling dependencies
 Some dependencies are not needed in all configurations. The following are some factors that affect the dependency list.
 
 #### Options passed to `./configure`
-* MiniUPnPc is not needed with  `--with-miniupnpc=no`.
+* MiniUPnPc is not needed with `--without-miniupnpc`.
+* libnatpmp is not needed with `--without-natpmp`.
 * Berkeley DB is not needed with `--disable-wallet` or `--without-bdb`.
 * SQLite is not needed with `--disable-wallet` or `--without-sqlite`.
 * Qt is not needed with `--without-gui`.

doc/productivity.md

@@ -51,6 +51,7 @@ After running `./autogen.sh`, which generates the `./configure` file, use `./con
 
 ```sh
 --without-miniupnpc
+--without-natpmp
 --disable-bench
 --disable-wallet
 --without-gui

doc/tor.md

@@ -99,7 +99,7 @@ as well, use `discover` instead:
 
 	./bitcoind ... -discover
 
-and open port 8333 on your firewall (or use -upnp).
+and open port 8333 on your firewall (or use port mapping, i.e., `-upnp` or `-natpmp`).
 
 If you only want to use Tor to reach .onion addresses, but not use it as a proxy
 for normal IPv4/IPv6 communication, use: