[PATCH nf v2 1/3] ipvs: pass parsed transport offset to state handlers

[Yizhou Zhao <zhaoyz24@xxxxxxxxxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxxxxxxxxx>
---
 include/net/ip_vs.h                   |  3 ++-
 net/netfilter/ipvs/ip_vs_core.c       | 10 +++++-----
 net/netfilter/ipvs/ip_vs_proto_sctp.c |  3 ++-
 net/netfilter/ipvs/ip_vs_proto_tcp.c  |  3 ++-
 net/netfilter/ipvs/ip_vs_proto_udp.c  |  3 ++-
 5 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 49297fec448a..417ff51f62fc 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -752,7 +752,8 @@ 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);
 
diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index d40b404c1bf6..bd90f03fe3a4 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -398,10 +398,10 @@ 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
@@ -803,7 +803,7 @@ 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);
@@ -1484,7 +1484,7 @@ 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);
@@ -2233,7 +2233,7 @@ 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 */
diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c 
b/net/netfilter/ipvs/ip_vs_proto_sctp.c
index 63c78a1f3918..394367b7b388 100644
--- a/net/netfilter/ipvs/ip_vs_proto_sctp.c
+++ b/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);
diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c 
b/net/netfilter/ipvs/ip_vs_proto_tcp.c
index 8cc0a8ce6241..2d3f6aeafe52 100644
--- a/net/netfilter/ipvs/ip_vs_proto_tcp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c
@@ -579,7 +579,8 @@ 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;
 
diff --git a/net/netfilter/ipvs/ip_vs_proto_udp.c 
b/net/netfilter/ipvs/ip_vs_proto_udp.c
index f9de632e38cd..58f9e255927e 100644
--- a/net/netfilter/ipvs/ip_vs_proto_udp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_udp.c
@@ -444,7 +444,8 @@ 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");
-- 
2.34.1