support OpenBSD in i2prouter

We don't include a wrapper for OpenBSD and Tanuki doesn't offer OpenBSD
binaries either. It is available as an OpenBSD package. Therefore, if the
wrapper is not found (likely), advise the user to install it. The next time
`i2prouter start` is run, the wrapper will be copied to the I2P install
directory and it should "just work".

installer/resources/i2prouter

@@ -527,6 +527,42 @@ outputFile() {
     fi
 }
 
+setup_openbsd() {
+    if ! pkg_info -qe 'java-tanukiwrapper->=3.5.19'; then
+        echo "Java wrapper not found. Either:"
+        echo "- install the package java-tanukiwrapper then start I2P again; or"
+        echo "- start I2P with $I2P/runplain.sh"
+        exit 1
+    else
+        # Wrapper package is installed so let's try copying the bits into the proper places
+        pkg_path=$(pkg_info -v java-tanukiwrapper   | awk '/^@cwd/{print $2}')
+        if [ -z $pkg_path ]; then
+            # Fallback, but we shouldn't end up here
+            echo "Unable to locate ${WRAPPER_CMD} in ${I2P}!"
+            echo
+            unsupported
+            exit 1
+        fi
+        set -e   # abort in case of error
+        # Package java-tanukiwrapper-3.5.19.1 misspells 'tanuki'
+        if [ -e "$pkg_path/lib/tanukuwrapper/libwrapper.so" ]; then
+            cp "$pkg_path/lib/tanukuwrapper/libwrapper.so" "$I2P/lib/libwrapper.so"
+        else    # they fixed the path
+            cp "$pkg_path/lib/tanukiwrapper/libwrapper.so" "$I2P/lib/libwrapper.so"
+        fi
+        cp "$pkg_path/share/java/classes/tanukiwrapper.jar" "$I2P/lib/wrapper.jar"
+        cp "$pkg_path/sbin/tanukiwrapper" "$WRAPPER_CMD"
+        chmod +x "$WRAPPER_CMD"
+    fi
+    set +e
+}
+
+if [ "$DIST_OS"="openbsd" -a ! -f "$WRAPPER_CMD" ]; then
+    # We handle it here because Tanuki doesn't ship OpenBSD binaries.
+    # We don't either, but they are (finally!) in OpenBSD itself.
+    setup_openbsd
+fi
+
 # Decide on the wrapper binary to use.
 # If the bits of the OS could be detected, we will try to look for the
 #  binary with the correct bits value.  If it doesn't exist, fall back