From a67fce7ffe7e4f38c54b65541d4f3372dd2516e9 Mon Sep 17 00:00:00 2001
From: Phil Sutter <phil@nwl.cc>
Date: Fri, 30 Jul 2021 17:26:31 +0200
Subject: scanner: nat: Move to own scope

Unify nat, masquerade and redirect statements, they widely share their
syntax.

Note the workaround of adding "prefix" to SCANSTATE_IP. This is required
to fix for 'snat ip prefix ...' style expressions.

Signed-off-by: Phil Sutter <phil@nwl.cc>
---
 src/parser_bison.y | 13 +++++++------
 src/scanner.l      | 21 ++++++++++++---------
 2 files changed, 19 insertions(+), 15 deletions(-)

(limited to 'src')

diff --git a/src/parser_bison.y b/src/parser_bison.y
index 2d419287..d8e9937b 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -955,6 +955,7 @@ close_scope_list	: { scanner_pop_start_cond(nft->scanner, PARSER_SC_CMD_LIST); }
 close_scope_limit	: { scanner_pop_start_cond(nft->scanner, PARSER_SC_LIMIT); };
 close_scope_mh		: { scanner_pop_start_cond(nft->scanner, PARSER_SC_EXPR_MH); };
 close_scope_monitor	: { scanner_pop_start_cond(nft->scanner, PARSER_SC_CMD_MONITOR); };
+close_scope_nat		: { scanner_pop_start_cond(nft->scanner, PARSER_SC_STMT_NAT); };
 close_scope_numgen	: { scanner_pop_start_cond(nft->scanner, PARSER_SC_EXPR_NUMGEN); };
 close_scope_osf		: { scanner_pop_start_cond(nft->scanner, PARSER_SC_EXPR_OSF); };
 close_scope_policy	: { scanner_pop_start_cond(nft->scanner, PARSER_SC_POLICY); };
@@ -2842,12 +2843,12 @@ stmt			:	verdict_stmt
 			|	meta_stmt
 			|	log_stmt	close_scope_log
 			|	reject_stmt	close_scope_reject
-			|	nat_stmt
+			|	nat_stmt	close_scope_nat
 			|	tproxy_stmt
 			|	queue_stmt
 			|	ct_stmt
-			|	masq_stmt
-			|	redir_stmt
+			|	masq_stmt	close_scope_nat
+			|	redir_stmt	close_scope_nat
 			|	dup_stmt
 			|	fwd_stmt
 			|	set_stmt
@@ -4768,8 +4769,8 @@ keyword_expr		:	ETHER   close_scope_eth { $$ = symbol_value(&@$, "ether"); }
 			|	IP6	close_scope_ip6 { $$ = symbol_value(&@$, "ip6"); }
 			|	VLAN	close_scope_vlan { $$ = symbol_value(&@$, "vlan"); }
 			|	ARP	close_scope_arp { $$ = symbol_value(&@$, "arp"); }
-			|	DNAT			{ $$ = symbol_value(&@$, "dnat"); }
-			|	SNAT			{ $$ = symbol_value(&@$, "snat"); }
+			|	DNAT	close_scope_nat	{ $$ = symbol_value(&@$, "dnat"); }
+			|	SNAT	close_scope_nat	{ $$ = symbol_value(&@$, "snat"); }
 			|	ECN			{ $$ = symbol_value(&@$, "ecn"); }
 			|	RESET	close_scope_reset	{ $$ = symbol_value(&@$, "reset"); }
 			|	ORIGINAL		{ $$ = symbol_value(&@$, "original"); }
@@ -4858,7 +4859,7 @@ primary_rhs_expr	:	symbol_expr		{ $$ = $1; }
 							 BYTEORDER_HOST_ENDIAN,
 							 sizeof(data) * BITS_PER_BYTE, &data);
 			}
-			|	REDIRECT
+			|	REDIRECT	close_scope_nat
 			{
 				uint8_t data = ICMP_REDIRECT;
 				$$ = constant_expr_alloc(&@$, &icmp_type_type,
diff --git a/src/scanner.l b/src/scanner.l
index b885f845..078bcc70 100644
--- a/src/scanner.l
+++ b/src/scanner.l
@@ -240,6 +240,7 @@ addrstring	({macaddr}|{ip4addr}|{ip6addr})
 %s SCANSTATE_EXPR_UDPLITE
 
 %s SCANSTATE_STMT_LOG
+%s SCANSTATE_STMT_NAT
 %s SCANSTATE_STMT_REJECT
 %s SCANSTATE_STMT_SYNPROXY
 
@@ -403,7 +404,7 @@ addrstring	({macaddr}|{ip4addr}|{ip6addr})
 }
 
 "log"			{ scanner_push_start_cond(yyscanner, SCANSTATE_STMT_LOG); return LOG; }
-"prefix"		{ return PREFIX; }
+<SCANSTATE_STMT_LOG,SCANSTATE_STMT_NAT,SCANSTATE_IP>"prefix"		{ return PREFIX; }
 <SCANSTATE_STMT_LOG>{
 	"snaplen"		{ return SNAPLEN; }
 	"queue-threshold"	{ return QUEUE_THRESHOLD; }
@@ -444,13 +445,16 @@ addrstring	({macaddr}|{ip4addr}|{ip6addr})
 	"icmpx"			{ return ICMPX; }
 }
 
-"snat"			{ return SNAT; }
-"dnat"			{ return DNAT; }
-"masquerade"		{ return MASQUERADE; }
-"redirect"		{ return REDIRECT; }
+"snat"			{ scanner_push_start_cond(yyscanner, SCANSTATE_STMT_NAT); return SNAT; }
+"dnat"			{ scanner_push_start_cond(yyscanner, SCANSTATE_STMT_NAT); return DNAT; }
+"masquerade"		{ scanner_push_start_cond(yyscanner, SCANSTATE_STMT_NAT); return MASQUERADE; }
+"redirect"		{ scanner_push_start_cond(yyscanner, SCANSTATE_STMT_NAT); return REDIRECT; }
 "random"		{ return RANDOM; }
-"fully-random"		{ return FULLY_RANDOM; }
-"persistent"		{ return PERSISTENT; }
+<SCANSTATE_STMT_NAT>{
+	"fully-random"		{ return FULLY_RANDOM; }
+	"persistent"		{ return PERSISTENT; }
+	"port"			{ return PORT; }
+}
 
 "ll"			{ return LL_HDR; }
 "nh"			{ return NETWORK_HDR; }
@@ -614,7 +618,6 @@ addrstring	({macaddr}|{ip4addr}|{ip6addr})
 <SCANSTATE_CT,SCANSTATE_EXPR_DCCP,SCANSTATE_SCTP,SCANSTATE_TCP,SCANSTATE_EXPR_TH,SCANSTATE_EXPR_UDP,SCANSTATE_EXPR_UDPLITE>{
 	"dport"			{ return DPORT; }
 }
-"port"			{ return PORT; }
 
 "tcp"			{ scanner_push_start_cond(yyscanner, SCANSTATE_TCP); return TCP; }
 
@@ -668,7 +671,7 @@ addrstring	({macaddr}|{ip4addr}|{ip6addr})
 "rt0"			{ scanner_push_start_cond(yyscanner, SCANSTATE_EXPR_RT); return RT0; }
 "rt2"			{ scanner_push_start_cond(yyscanner, SCANSTATE_EXPR_RT); return RT2; }
 "srh"			{ scanner_push_start_cond(yyscanner, SCANSTATE_EXPR_RT); return RT4; }
-"addr"			{ return ADDR; }
+<SCANSTATE_EXPR_RT,SCANSTATE_STMT_NAT>"addr"			{ return ADDR; }
 
 "hbh"			{ scanner_push_start_cond(yyscanner, SCANSTATE_EXPR_HBH); return HBH; }
 
-- 
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