xshared: Share print_fragment() with legacy

Also add a fake mode to make it suitable for ip6tables. This is required
because IPT_F_FRAG value clashes with IP6T_F_PROTO, so ip6tables rules
might seem to have IPT_F_FRAG bit set.

While being at it, drop the local variable 'flags' from
print_firewall().

Signed-off-by: Phil Sutter <phil@nwl.cc>

6 files changed, 25 insertions, 35 deletions

diff --git a/iptables/ip6tables.c b/iptables/ip6tables.c
index e0cc4e89..3d304d44 100644
--- a/iptables/ip6tables.c
+++ b/iptables/ip6tables.c
@@ -332,13 +332,7 @@ print_firewall(const struct ip6t_entry *fw,
 	print_rule_details(num, &fw->counters, targname, fw->ipv6.proto,
 			   fw->ipv6.flags, fw->ipv6.invflags, format);
 
-	if (format & FMT_OPTIONS) {
-		if (format & FMT_NOTABLE)
-			fputs("opt ", stdout);
-		fputc(' ', stdout); /* Invert flag of FRAG */
-		fputc(' ', stdout); /* -f */
-		fputc(' ', stdout);
-	}
+	print_fragment(fw->ipv6.flags, fw->ipv6.invflags, format, true);
 
 	print_ifaces(fw->ipv6.iniface, fw->ipv6.outiface,
 		     fw->ipv6.invflags, format);
diff --git a/iptables/iptables.c b/iptables/iptables.c
index 29da40b1..12a5423e 100644
--- a/iptables/iptables.c
+++ b/iptables/iptables.c
@@ -311,7 +311,6 @@ print_firewall(const struct ipt_entry *fw,
 {
 	struct xtables_target *target, *tg;
 	const struct xt_entry_target *t;
-	uint8_t flags;
 
 	if (!iptc_is_chain(targname, handle))
 		target = xtables_find_target(targname, XTF_TRY_LOAD);
@@ -320,18 +319,11 @@ print_firewall(const struct ipt_entry *fw,
 		         XTF_LOAD_MUST_SUCCEED);
 
 	t = ipt_get_target((struct ipt_entry *)fw);
-	flags = fw->ip.flags;
 
 	print_rule_details(num, &fw->counters, targname, fw->ip.proto,
 			   fw->ip.flags, fw->ip.invflags, format);
 
-	if (format & FMT_OPTIONS) {
-		if (format & FMT_NOTABLE)
-			fputs("opt ", stdout);
-		fputc(fw->ip.invflags & IPT_INV_FRAG ? '!' : '-', stdout);
-		fputc(flags & IPT_F_FRAG ? 'f' : '-', stdout);
-		fputc(' ', stdout);
-	}
+	print_fragment(fw->ip.flags, fw->ip.invflags, format, false);
 
 	print_ifaces(fw->ip.iniface, fw->ip.outiface, fw->ip.invflags, format);
 
diff --git a/iptables/nft-ipv4.c b/iptables/nft-ipv4.c
index 6b044642..f3626098 100644
--- a/iptables/nft-ipv4.c
+++ b/iptables/nft-ipv4.c
@@ -226,19 +226,6 @@ static void nft_ipv4_parse_immediate(const char *jumpto, bool nft_goto,
 		cs->fw.ip.flags |= IPT_F_GOTO;
 }
 
-static void print_fragment(unsigned int flags, unsigned int invflags,
-			   unsigned int format)
-{
-	if (!(format & FMT_OPTIONS))
-		return;
-
-	if (format & FMT_NOTABLE)
-		fputs("opt ", stdout);
-	fputc(invflags & IPT_INV_FRAG ? '!' : '-', stdout);
-	fputc(flags & IPT_F_FRAG ? 'f' : '-', stdout);
-	fputc(' ', stdout);
-}
-
 static void nft_ipv4_print_rule(struct nft_handle *h, struct nftnl_rule *r,
 				unsigned int num, unsigned int format)
 {
@@ -248,7 +235,7 @@ static void nft_ipv4_print_rule(struct nft_handle *h, struct nftnl_rule *r,
 
 	print_rule_details(num, &cs.counters, cs.jumpto, cs.fw.ip.proto,
 			   cs.fw.ip.flags, cs.fw.ip.invflags, format);
-	print_fragment(cs.fw.ip.flags, cs.fw.ip.invflags, format);
+	print_fragment(cs.fw.ip.flags, cs.fw.ip.invflags, format, false);
 	print_ifaces(cs.fw.ip.iniface, cs.fw.ip.outiface, cs.fw.ip.invflags,
 		     format);
 	print_ipv4_addresses(&cs.fw, format);
diff --git a/iptables/nft-ipv6.c b/iptables/nft-ipv6.c
index cb83f9e1..13213088 100644
--- a/iptables/nft-ipv6.c
+++ b/iptables/nft-ipv6.c
@@ -200,11 +200,7 @@ static void nft_ipv6_print_rule(struct nft_handle *h, struct nftnl_rule *r,
 
 	print_rule_details(num, &cs.counters, cs.jumpto, cs.fw6.ipv6.proto,
 			   cs.fw6.ipv6.flags, cs.fw6.ipv6.invflags, format);
-	if (format & FMT_OPTIONS) {
-		if (format & FMT_NOTABLE)
-			fputs("opt ", stdout);
-		fputs("   ", stdout);
-	}
+	print_fragment(cs.fw6.ipv6.flags, cs.fw6.ipv6.invflags, format, true);
 	print_ifaces(cs.fw6.ipv6.iniface, cs.fw6.ipv6.outiface,
 		     cs.fw6.ipv6.invflags, format);
 	print_ipv6_addresses(&cs.fw6, format);
diff --git a/iptables/xshared.c b/iptables/xshared.c
index 7f2e1a32..e8c8939c 100644
--- a/iptables/xshared.c
+++ b/iptables/xshared.c
@@ -669,6 +669,24 @@ void save_ipv6_addr(char letter, const struct in6_addr *addr,
 		printf("/%d", l);
 }
 
+void print_fragment(unsigned int flags, unsigned int invflags,
+		    unsigned int format, bool fake)
+{
+	if (!(format & FMT_OPTIONS))
+		return;
+
+	if (format & FMT_NOTABLE)
+		fputs("opt ", stdout);
+
+	if (fake) {
+		fputs("  ", stdout);
+	} else {
+		fputc(invflags & IPT_INV_FRAG ? '!' : '-', stdout);
+		fputc(flags & IPT_F_FRAG ? 'f' : '-', stdout);
+	}
+	fputc(' ', stdout);
+}
+
 /* Luckily, IPT_INV_VIA_IN and IPT_INV_VIA_OUT
  * have the same values as IP6T_INV_VIA_IN and IP6T_INV_VIA_OUT
  * so this function serves for both iptables and ip6tables */
diff --git a/iptables/xshared.h b/iptables/xshared.h
index 9f0fa143..48f314ca 100644
--- a/iptables/xshared.h
+++ b/iptables/xshared.h
@@ -232,6 +232,9 @@ void print_ifaces(const char *iniface, const char *outiface, uint8_t invflags,
 void save_iface(char letter, const char *iface,
 		const unsigned char *mask, int invert);
 
+void print_fragment(unsigned int flags, unsigned int invflags,
+		    unsigned int format, bool fake);
+
 void command_match(struct iptables_command_state *cs, bool invert);
 const char *xt_parse_target(const char *targetname);
 void command_jump(struct iptables_command_state *cs, const char *jumpto);