[PATCH nft v3 05/10] parser: add typeof keyword for declarations

[Florian Westphal <fw@strlen.de>]

From: Pablo Neira Ayuso <pablo@netfilter.org>

Add a typeof keyword to automatically use the correct type in set and map
declarations.

table filter {
	set blacklist {
		typeof ip saddr
	}

	chain input {
		ip saddr @blacklist counter drop
	}
}

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
---
 src/parser_bison.y | 46 ++++++++++++++++++++++++++++++++++++++++++++--
 src/scanner.l      |  1 +
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/src/parser_bison.y b/src/parser_bison.y
index 6d17539fa57e..799f7a308b07 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -223,6 +223,8 @@ int nft_lex(void *, void *, void *);
 %token WSCALE			"wscale"
 %token SACKPERM			"sack-perm"
 
+%token TYPEOF			"typeof"
+
 %token HOOK			"hook"
 %token DEVICE			"device"
 %token DEVICES			"devices"
@@ -658,8 +660,8 @@ int nft_lex(void *, void *, void *);
 
 %type <expr>			symbol_expr verdict_expr integer_expr variable_expr chain_expr policy_expr
 %destructor { expr_free($$); }	symbol_expr verdict_expr integer_expr variable_expr chain_expr policy_expr
-%type <expr>			primary_expr shift_expr and_expr
-%destructor { expr_free($$); }	primary_expr shift_expr and_expr
+%type <expr>			primary_expr shift_expr and_expr typeof_expr
+%destructor { expr_free($$); }	primary_expr shift_expr and_expr typeof_expr
 %type <expr>			exclusive_or_expr inclusive_or_expr
 %destructor { expr_free($$); }	exclusive_or_expr inclusive_or_expr
 %type <expr>			basic_expr
@@ -1671,6 +1673,29 @@ chain_block		:	/* empty */	{ $$ = $<chain>-1; }
 			}
 			;
 
+typeof_expr		:	primary_expr
+			{
+				if (expr_ops($1)->build_udata == NULL) {
+					erec_queue(error(&@1, "primary expression type '%s' lacks typeof serialization", expr_ops($1)->name),
+						   state->msgs);
+					expr_free($1);
+					YYERROR;
+				}
+
+				$$ = $1;
+			}
+			|	typeof_expr		DOT		primary_expr
+			{
+				struct location rhs[] = {
+					[1]	= @2,
+					[2]	= @3,
+				};
+
+				$$ = handle_concat_expr(&@$, $$, $1, $3, rhs);
+			}
+			;
+
+
 set_block_alloc		:	/* empty */
 			{
 				$$ = set_alloc(NULL);
@@ -1685,6 +1710,12 @@ set_block		:	/* empty */	{ $$ = $<set>-1; }
 				$1->key = $3;
 				$$ = $1;
 			}
+			|	set_block	TYPEOF		typeof_expr	stmt_separator
+			{
+				$1->key = $3;
+				datatype_set($1->key, $3->dtype);
+				$$ = $1;
+			}
 			|	set_block	FLAGS		set_flag_list	stmt_separator
 			{
 				$1->flags = $3;
@@ -1754,6 +1785,17 @@ map_block		:	/* empty */	{ $$ = $<set>-1; }
 				$1->flags |= NFT_SET_MAP;
 				$$ = $1;
 			}
+			|	map_block	TYPEOF
+						typeof_expr	COLON	typeof_expr
+						stmt_separator
+			{
+				$1->key = $3;
+				datatype_set($1->key, $3->dtype);
+				$1->data = $5;
+
+				$1->flags |= NFT_SET_MAP;
+				$$ = $1;
+			}
 			|	map_block	TYPE
 						data_type_expr	COLON	COUNTER
 						stmt_separator
diff --git a/src/scanner.l b/src/scanner.l
index d32adf4897ae..4fbdcf2afa4b 100644
--- a/src/scanner.l
+++ b/src/scanner.l
@@ -385,6 +385,7 @@ addrstring	({macaddr}|{ip4addr}|{ip6addr})
 "saddr"			{ return SADDR; }
 "daddr"			{ return DADDR; }
 "type"			{ return TYPE; }
+"typeof"		{ return TYPEOF; }
 
 "vlan"			{ return VLAN; }
 "id"			{ return ID; }
-- 
2.24.1