ipvs: pass parsed transport offset to state handlers

[ Upstream commit bae7ce7 ]

IPVS callers already parse the packet into struct ip_vs_iphdr before
updating connection state. For IPv6 this records the real
transport-header offset after extension headers in iph.len.

Pass this parsed transport offset through ip_vs_set_state() and the
protocol state_transition() callback so protocol handlers can use the
same packet context as scheduling and NAT handling. This patch only
changes the common callback plumbing and adapts the protocol callback
signatures; TCP and SCTP start using the value in follow-up patches.

Signed-off-by: Yizhou Zhao <zhaoyz24@mails.tsinghua.edu.cn>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Stable-dep-of: 2500fa3 ("ipvs: use parsed transport offset in TCP state lookup")
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: ArtisticFantasy

include/net/ip_vs.h

@@ -455,7 +455,8 @@ struct ip_vs_protocol {
 
 	void (*state_transition)(struct ip_vs_conn *cp, int direction,
 				 const struct sk_buff *skb,
-				 struct ip_vs_proto_data *pd);
+				 struct ip_vs_proto_data *pd,
+				 unsigned int iph_len);
 
 	int (*register_app)(struct netns_ipvs *ipvs, struct ip_vs_app *inc);
 

net/netfilter/ipvs/ip_vs_core.c

@@ -220,10 +220,10 @@ ip_vs_conn_stats(struct ip_vs_conn *cp, struct ip_vs_service *svc)
 static inline void
 ip_vs_set_state(struct ip_vs_conn *cp, int direction,
 		const struct sk_buff *skb,
-		struct ip_vs_proto_data *pd)
+		struct ip_vs_proto_data *pd, unsigned int iph_len)
 {
 	if (likely(pd->pp->state_transition))
-		pd->pp->state_transition(cp, direction, skb, pd);
+		pd->pp->state_transition(cp, direction, skb, pd, iph_len);
 }
 
 static inline int
@@ -625,7 +625,7 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
 		ip_vs_in_stats(cp, skb);
 
 		/* set state */
-		ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
+		ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd, iph->len);
 
 		/* transmit the first SYN packet */
 		ret = cp->packet_xmit(skb, cp, pd->pp, iph);
@@ -1308,7 +1308,7 @@ handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
 
 after_nat:
 	ip_vs_out_stats(cp, skb);
-	ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd);
+	ip_vs_set_state(cp, IP_VS_DIR_OUTPUT, skb, pd, iph->len);
 	skb->ipvs_property = 1;
 	if (!(cp->flags & IP_VS_CONN_F_NFCT))
 		ip_vs_notrack(skb);
@@ -2060,7 +2060,7 @@ ip_vs_in_hook(void *priv, struct sk_buff *skb, const struct nf_hook_state *state
 	IP_VS_DBG_PKT(11, af, pp, skb, iph.off, "Incoming packet");
 
 	ip_vs_in_stats(cp, skb);
-	ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
+	ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd, iph.len);
 	if (cp->packet_xmit)
 		ret = cp->packet_xmit(skb, cp, pp, &iph);
 		/* do not touch skb anymore */

net/netfilter/ipvs/ip_vs_proto_sctp.c

@@ -468,7 +468,8 @@ set_sctp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
 
 static void
 sctp_state_transition(struct ip_vs_conn *cp, int direction,
-		const struct sk_buff *skb, struct ip_vs_proto_data *pd)
+		const struct sk_buff *skb, struct ip_vs_proto_data *pd,
+		unsigned int iph_len)
 {
 	spin_lock_bh(&cp->lock);
 	set_sctp_state(pd, cp, direction, skb);

net/netfilter/ipvs/ip_vs_proto_tcp.c

@@ -580,7 +580,8 @@ set_tcp_state(struct ip_vs_proto_data *pd, struct ip_vs_conn *cp,
 static void
 tcp_state_transition(struct ip_vs_conn *cp, int direction,
 		     const struct sk_buff *skb,
-		     struct ip_vs_proto_data *pd)
+		     struct ip_vs_proto_data *pd,
+		     unsigned int iph_len)
 {
 	struct tcphdr _tcph, *th;
 

net/netfilter/ipvs/ip_vs_proto_udp.c

@@ -445,7 +445,8 @@ static const char * udp_state_name(int state)
 static void
 udp_state_transition(struct ip_vs_conn *cp, int direction,
 		     const struct sk_buff *skb,
-		     struct ip_vs_proto_data *pd)
+		     struct ip_vs_proto_data *pd,
+		     unsigned int iph_len)
 {
 	if (unlikely(!pd)) {
 		pr_err("UDP no ns data\n");