src: add `flush ruleset'

This patch adds the `flush ruleset' operation to nft.

The syntax is:
 % nft flush ruleset [family]

To flush all the ruleset (all families):
 % nft flush ruleset

To flush the ruleset of a given family:
 % nft flush ruleset ip
 % nft flush ruleset inet

This flush is a shortcut operation which deletes all rules, sets, tables
and chains.
It's possible since the modifications in the kernel to the NFT_MSG_DELTABLE
API call.

Users can benefit of this operation when doing an atomic replacement of the
entire ruleset, loading a file like this:

 =========
 flush ruleset
 table ip filter {
 	chain input {
		counter accept
	}
 }
 =========

Also, users who want to simply clean the ruleset for whatever reason can do it now
without having to iterate families/tables.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 25 insertions, 5 deletions

diff --git a/src/parser.y b/src/parser.y
index a4ccf732..aa40f905 100644
--- a/src/parser.y
+++ b/src/parser.y
@@ -187,6 +187,7 @@ static int monitor_lookup_event(const char *event)
 %token ELEMENT			"element"
 %token MAP			"map"
 %token HANDLE			"handle"
+%token RULESET			"ruleset"
 
 %token INET			"inet"
 
@@ -397,11 +398,11 @@ static int monitor_lookup_event(const char *event)
 %type <cmd>			base_cmd add_cmd create_cmd insert_cmd delete_cmd list_cmd flush_cmd rename_cmd export_cmd monitor_cmd
 %destructor { cmd_free($$); }	base_cmd add_cmd create_cmd insert_cmd delete_cmd list_cmd flush_cmd rename_cmd export_cmd monitor_cmd
 
-%type <handle>			table_spec tables_spec chain_spec chain_identifier ruleid_spec
-%destructor { handle_free(&$$); } table_spec tables_spec chain_spec chain_identifier ruleid_spec
+%type <handle>			table_spec tables_spec chain_spec chain_identifier ruleid_spec ruleset_spec
+%destructor { handle_free(&$$); } table_spec tables_spec chain_spec chain_identifier ruleid_spec ruleset_spec
 %type <handle>			set_spec set_identifier
 %destructor { handle_free(&$$); } set_spec set_identifier
-%type <val>			handle_spec family_spec position_spec
+%type <val>			handle_spec family_spec family_spec_explicit position_spec
 
 %type <table>			table_block_alloc table_block
 %destructor { close_scope(state); table_free($$); }	table_block_alloc
@@ -775,6 +776,10 @@ flush_cmd		:	TABLE		table_spec
 			{
 				$$ = cmd_alloc(CMD_FLUSH, CMD_OBJ_SET, &$2, &@$, NULL);
 			}
+			|	RULESET		ruleset_spec
+			{
+				$$ = cmd_alloc(CMD_FLUSH, CMD_OBJ_RULESET, &$2, &@$, NULL);
+			}
 			;
 
 rename_cmd		:	CHAIN		chain_spec	identifier
@@ -1164,8 +1169,11 @@ string			:	STRING
 			|	QUOTED_STRING
 			;
 
-family_spec		:	/* empty */	{ $$ = NFPROTO_IPV4; }
-			|	IP		{ $$ = NFPROTO_IPV4; }
+family_spec		:	/* empty */		{ $$ = NFPROTO_IPV4; }
+			|	family_spec_explicit
+			;
+
+family_spec_explicit	:	IP		{ $$ = NFPROTO_IPV4; }
 			|	IP6		{ $$ = NFPROTO_IPV6; }
 			|	INET		{ $$ = NFPROTO_INET; }
 			|	ARP		{ $$ = NFPROTO_ARP; }
@@ -1254,6 +1262,18 @@ comment_spec		:	/* empty */
 			}
 			;
 
+ruleset_spec		:	/* empty */
+			{
+				memset(&$$, 0, sizeof($$));
+				$$.family	= NFPROTO_UNSPEC;
+			}
+			|	family_spec_explicit
+			{
+				memset(&$$, 0, sizeof($$));
+				$$.family	= $1;
+			}
+			;
+
 rule			:	stmt_list	comment_spec
 			{
 				struct stmt *i;