Implement --echo option

When used with add, insert or replace commands, nft tool will print
event notifications just like 'nft monitor' does for the same commands.

Apart from seeing what a given command will turn out in the rule set,
this allows to reliably retrieve a new rule's assigned handle (if used
together with --handle option).

Here are some examples of how it works:

| # nft --echo --handle add table ip t
| add table ip t
|
| # nft --echo --handle add chain ip t c \
| 	'{ type filter hook forward priority 0; }'
| add chain ip t c { type filter hook forward priority 0; policy accept; }
|
| # nft --echo --handle add rule ip t c tcp dport '{22, 80}' accept
| add rule ip t c tcp dport { ssh, http } accept # handle 2
|
| # nft --echo --handle add set ip t ipset '{ type ipv4_addr; \
| 	elements = { 192.168.0.1, 192.168.0.2 }; }'
| add set ip t ipset { type ipv4_addr; }
| add element ip t ipset { 192.168.0.1 }
| add element ip t ipset { 192.168.0.2 }

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

0 files changed, 0 insertions, 0 deletions