ipvs: API change to avoid rescan of IPv6 exthdr

Reduce the number of times we scan/skip the IPv6 exthdrs.

This patch contains a lot of API changes.  This is done, to avoid
repeating the scan of finding the IPv6 headers, via ipv6_find_hdr(),
which is called by ip_vs_fill_iph_skb().

Finding the IPv6 headers is done as early as possible, and passed on
as a pointer "struct ip_vs_iphdr *" to the affected functions.

This patch reduce/removes 19 calls to ip_vs_fill_iph_skb().

Notice, I have choosen, not to change the API of function
pointer "(*schedule)" (in struct ip_vs_scheduler) as it can be
used by external schedulers, via {un,}register_ip_vs_scheduler.
Only 4 out of 10 schedulers use info from ip_vs_iphdr*, and when
they do, they are only interested in iph->{s,d}addr.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>

1 files changed, 25 insertions, 33 deletions

diff --git a/net/netfilter/ipvs/ip_vs_xmit.c b/net/netfilter/ipvs/ip_vs_xmit.c
index a8b75fc8e6a..90122eb0b04 100644
--- a/net/netfilter/ipvs/ip_vs_xmit.c
+++ b/net/netfilter/ipvs/ip_vs_xmit.c
@@ -424,7 +424,7 @@ do {							\
  */
 int
 ip_vs_null_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
-		struct ip_vs_protocol *pp)
+		struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
 {
 	/* we do not touch skb and do not need pskb ptr */
 	IP_VS_XMIT(NFPROTO_IPV4, skb, cp, 1);
@@ -438,7 +438,7 @@ ip_vs_null_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
  */
 int
 ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
-		  struct ip_vs_protocol *pp)
+		  struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
 {
 	struct rtable *rt;			/* Route to the other host */
 	struct iphdr  *iph = ip_hdr(skb);
@@ -493,16 +493,14 @@ ip_vs_bypass_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 #ifdef CONFIG_IP_VS_IPV6
 int
 ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
-		     struct ip_vs_protocol *pp)
+		     struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph)
 {
 	struct rt6_info *rt;			/* Route to the other host */
-	struct ip_vs_iphdr iph;
 	int    mtu;
 
 	EnterFunction(10);
-	ip_vs_fill_iph_skb(cp->af, skb, &iph);
 
-	rt = __ip_vs_get_out_rt_v6(skb, NULL, &iph.daddr.in6, NULL, 0,
+	rt = __ip_vs_get_out_rt_v6(skb, NULL, &iph->daddr.in6, NULL, 0,
 				   IP_VS_RT_MODE_NON_LOCAL);
 	if (!rt)
 		goto tx_error_icmp;
@@ -516,7 +514,7 @@ ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 			skb->dev = net->loopback_dev;
 		}
 		/* only send ICMP too big on first fragment */
-		if (!iph.fragoffs)
+		if (!iph->fragoffs)
 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		dst_release(&rt->dst);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
@@ -560,7 +558,7 @@ ip_vs_bypass_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
  */
 int
 ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
-	       struct ip_vs_protocol *pp)
+	       struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
 {
 	struct rtable *rt;		/* Route to the other host */
 	int mtu;
@@ -630,7 +628,7 @@ ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 		goto tx_error_put;
 
 	/* mangle the packet */
-	if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp))
+	if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp, ipvsh))
 		goto tx_error_put;
 	ip_hdr(skb)->daddr = cp->daddr.ip;
 	ip_send_check(ip_hdr(skb));
@@ -678,20 +676,18 @@ ip_vs_nat_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 #ifdef CONFIG_IP_VS_IPV6
 int
 ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
-		  struct ip_vs_protocol *pp)
+		  struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph)
 {
 	struct rt6_info *rt;		/* Route to the other host */
 	int mtu;
 	int local;
-	struct ip_vs_iphdr iph;
 
 	EnterFunction(10);
-	ip_vs_fill_iph_skb(cp->af, skb, &iph);
 
 	/* check if it is a connection of no-client-port */
-	if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT && !iph.fragoffs)) {
+	if (unlikely(cp->flags & IP_VS_CONN_F_NO_CPORT && !iph->fragoffs)) {
 		__be16 _pt, *p;
-		p = skb_header_pointer(skb, iph.len, sizeof(_pt), &_pt);
+		p = skb_header_pointer(skb, iph->len, sizeof(_pt), &_pt);
 		if (p == NULL)
 			goto tx_error;
 		ip_vs_conn_fill_cport(cp, *p);
@@ -740,7 +736,7 @@ ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 			skb->dev = net->loopback_dev;
 		}
 		/* only send ICMP too big on first fragment */
-		if (!iph.fragoffs)
+		if (!iph->fragoffs)
 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		IP_VS_DBG_RL_PKT(0, AF_INET6, pp, skb, 0,
 				 "ip_vs_nat_xmit_v6(): frag needed for");
@@ -755,7 +751,7 @@ ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 		goto tx_error_put;
 
 	/* mangle the packet */
-	if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp))
+	if (pp->dnat_handler && !pp->dnat_handler(skb, pp, cp, iph))
 		goto tx_error;
 	ipv6_hdr(skb)->daddr = cp->daddr.in6;
 
@@ -816,7 +812,7 @@ tx_error_put:
  */
 int
 ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
-		  struct ip_vs_protocol *pp)
+		  struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
 {
 	struct netns_ipvs *ipvs = net_ipvs(skb_net(skb));
 	struct rtable *rt;			/* Route to the other host */
@@ -936,7 +932,7 @@ tx_error_put:
 #ifdef CONFIG_IP_VS_IPV6
 int
 ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
-		     struct ip_vs_protocol *pp)
+		     struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
 {
 	struct rt6_info *rt;		/* Route to the other host */
 	struct in6_addr saddr;		/* Source for tunnel */
@@ -946,10 +942,8 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 	unsigned int max_headroom;	/* The extra header space needed */
 	int    mtu;
 	int ret;
-	struct ip_vs_iphdr ipvsh;
 
 	EnterFunction(10);
-	ip_vs_fill_iph_skb(cp->af, skb, &ipvsh);
 
 	if (!(rt = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6,
 					 &saddr, 1, (IP_VS_RT_MODE_LOCAL |
@@ -979,7 +973,7 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 			skb->dev = net->loopback_dev;
 		}
 		/* only send ICMP too big on first fragment */
-		if (!ipvsh.fragoffs)
+		if (!ipvsh->fragoffs)
 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
 		goto tx_error_put;
@@ -1061,7 +1055,7 @@ tx_error_put:
  */
 int
 ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
-	      struct ip_vs_protocol *pp)
+	      struct ip_vs_protocol *pp, struct ip_vs_iphdr *ipvsh)
 {
 	struct rtable *rt;			/* Route to the other host */
 	struct iphdr  *iph = ip_hdr(skb);
@@ -1122,14 +1116,12 @@ ip_vs_dr_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 #ifdef CONFIG_IP_VS_IPV6
 int
 ip_vs_dr_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
-		 struct ip_vs_protocol *pp)
+		 struct ip_vs_protocol *pp, struct ip_vs_iphdr *iph)
 {
 	struct rt6_info *rt;			/* Route to the other host */
 	int    mtu;
-	struct ip_vs_iphdr iph;
 
 	EnterFunction(10);
-	ip_vs_fill_iph_skb(cp->af, skb, &iph);
 
 	if (!(rt = __ip_vs_get_out_rt_v6(skb, cp->dest, &cp->daddr.in6, NULL,
 					 0, (IP_VS_RT_MODE_LOCAL |
@@ -1149,7 +1141,7 @@ ip_vs_dr_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 			skb->dev = net->loopback_dev;
 		}
 		/* only send ICMP too big on first fragment */
-		if (!iph.fragoffs)
+		if (!iph->fragoffs)
 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		dst_release(&rt->dst);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
@@ -1194,7 +1186,8 @@ tx_error:
  */
 int
 ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
-		struct ip_vs_protocol *pp, int offset, unsigned int hooknum)
+		struct ip_vs_protocol *pp, int offset, unsigned int hooknum,
+		struct ip_vs_iphdr *iph)
 {
 	struct rtable	*rt;	/* Route to the other host */
 	int mtu;
@@ -1209,7 +1202,7 @@ ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 	   translate address/port back */
 	if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
 		if (cp->packet_xmit)
-			rc = cp->packet_xmit(skb, cp, pp);
+			rc = cp->packet_xmit(skb, cp, pp, iph);
 		else
 			rc = NF_ACCEPT;
 		/* do not touch skb anymore */
@@ -1315,24 +1308,23 @@ ip_vs_icmp_xmit(struct sk_buff *skb, struct ip_vs_conn *cp,
 #ifdef CONFIG_IP_VS_IPV6
 int
 ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
-		struct ip_vs_protocol *pp, int offset, unsigned int hooknum)
+		struct ip_vs_protocol *pp, int offset, unsigned int hooknum,
+		struct ip_vs_iphdr *iph)
 {
 	struct rt6_info	*rt;	/* Route to the other host */
 	int mtu;
 	int rc;
 	int local;
 	int rt_mode;
-	struct ip_vs_iphdr iph;
 
 	EnterFunction(10);
-	ip_vs_fill_iph_skb(cp->af, skb, &iph);
 
 	/* The ICMP packet for VS/TUN, VS/DR and LOCALNODE will be
 	   forwarded directly here, because there is no need to
 	   translate address/port back */
 	if (IP_VS_FWD_METHOD(cp) != IP_VS_CONN_F_MASQ) {
 		if (cp->packet_xmit)
-			rc = cp->packet_xmit(skb, cp, pp);
+			rc = cp->packet_xmit(skb, cp, pp, iph);
 		else
 			rc = NF_ACCEPT;
 		/* do not touch skb anymore */
@@ -1389,7 +1381,7 @@ ip_vs_icmp_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp,
 			skb->dev = net->loopback_dev;
 		}
 		/* only send ICMP too big on first fragment */
-		if (!iph.fragoffs)
+		if (!iph->fragoffs)
 			icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 		IP_VS_DBG_RL("%s(): frag needed\n", __func__);
 		goto tx_error_put;