nat: T2198: migrate "show nat" commands to XML and Python

- "show nat source|destination statistics" is now implemented in Python
- "show nat source|destination rules" needs a new implementation, see T2459
- "show nat source|destination translations" has been copied over from the old
  repo and is here until it is rewritten, this was not possible for "rules"
  as there would have been too much dependencies. This one only requires
  libxml-simple-perl

1 files changed, 63 insertions, 0 deletions

diff --git a/src/op_mode/show_nat_statistics.py b/src/op_mode/show_nat_statistics.py
new file mode 100755
index 000000000..b77693e19
--- /dev/null
+++ b/src/op_mode/show_nat_statistics.py
@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2018 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import jmespath
+import json
+
+from argparse import ArgumentParser
+from jinja2 import Template
+from sys import exit
+from vyos.util import cmd
+
+OUT_TMPL_SRC="""
+rule      pkts        bytes   interface
+----      ----        -----   ---------
+{% for r in output %}
+{%- if r.comment -%}
+{%- set packets   = r.counter.packets -%}
+{%- set bytes     = r.counter.bytes -%}
+{%- set interface = r.interface -%}
+{# remove rule comment prefix #}
+{%- set comment   = r.comment | replace('SRC-NAT-', '') | replace('DST-NAT-', '') -%}
+{{ "%-4s" | format(comment) }} {{ "%9s" | format(packets) }} {{ "%12s" | format(bytes) }}   {{ interface }}
+{%- endif %}
+{% endfor %}
+"""
+
+parser = ArgumentParser()
+group = parser.add_mutually_exclusive_group()
+group.add_argument("--source", help="Show statistics for configured source NAT rules", action="store_true")
+group.add_argument("--destination", help="Show statistics for configured destination NAT rules", action="store_true")
+args = parser.parse_args()
+
+if args.source or args.destination:
+    tmp = cmd('sudo nft -j list table nat')
+    tmp = json.loads(tmp)
+
+    source = r"nftables[?rule.chain=='POSTROUTING'].rule.{chain: chain, handle: handle, comment: comment, counter: expr[].counter | [0], interface: expr[].match.right | [0] }"
+    destination = r"nftables[?rule.chain=='PREROUTING'].rule.{chain: chain, handle: handle, comment: comment, counter: expr[].counter | [0], interface: expr[].match.right | [0] }"
+    data = {
+        'output' : jmespath.search(source if args.source else destination, tmp),
+        'direction' : 'source' if args.source else 'destination'
+    }
+
+    tmpl = Template(OUT_TMPL_SRC, lstrip_blocks=True)
+    print(tmpl.render(data))
+    exit(0)
+else:
+    parser.print_help()
+    exit(1)
+