[bug#49540] [PATCH 1/2] services: nftables: Only manage delete our own table.

[Brice Waegeneire <brice@waegenei.re>]

* gnu/services/networking.scm (%default-nftables-ruleset): Rename table
  from "forward" to "guix".  Clear table before applying before setting
  it up.
(nftables-shepherd-service): Don't flush all the table, just delete our
  own.
---
 gnu/services/networking.scm | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/gnu/services/networking.scm b/gnu/services/networking.scm
index 1ae58041d3..3058c14caf 100644
--- a/gnu/services/networking.scm
+++ b/gnu/services/networking.scm
@@ -13,7 +13,7 @@
 ;;; Copyright © 2019, 2021 Maxim Cournoyer <maxim.cournoyer@gmail.com>
 ;;; Copyright © 2019 Sou Bunnbu <iyzsong@member.fsf.org>
 ;;; Copyright © 2019 Alex Griffin <a@ajgrf.com>
-;;; Copyright © 2020 Brice Waegeneire <brice@waegenei.re>
+;;; Copyright © 2020, 2021 Brice Waegeneire <brice@waegenei.re>
 ;;; Copyright © 2021 Oleg Pykhalov <go.wigust@gmail.com>
 ;;; Copyright © 2021 Christopher Lemmer Webber <cwebber@dustycloud.org>
 ;;; Copyright © 2021 Maxime Devos <maximedevos@telenet.be>
@@ -1717,7 +1717,12 @@ COMMIT
 (define %default-nftables-ruleset
   (plain-file "nftables.conf"
               "# A simple and safe firewall
-table inet filter {
+
+# Start with our table clean of previous state
+add table inet guix
+delete table inet guix
+
+table inet guix {
   chain input {
     type filter hook input priority 0; policy drop;
 
@@ -1768,7 +1773,7 @@ table inet filter {
         (start #~(lambda _
                    (invoke #$nft "--file" #$ruleset)))
         (stop #~(lambda _
-                  (invoke #$nft "flush" "ruleset"))))))))
+                  (invoke #$nft "delete" "table" "inet" "guix"))))))))
 
 (define nftables-service-type
   (service-type
-- 
2.31.1