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, 51 insertions, 65 deletions

diff --git a/net/netfilter/ipvs/ip_vs_core.c b/net/netfilter/ipvs/ip_vs_core.c
index 19b89ff..fb45640 100644
--- a/net/netfilter/ipvs/ip_vs_core.c
+++ b/net/netfilter/ipvs/ip_vs_core.c
@@ -222,11 +222,10 @@ ip_vs_conn_fill_param_persist(const struct ip_vs_service *svc,
  */
 static struct ip_vs_conn *
 ip_vs_sched_persist(struct ip_vs_service *svc,
-		    struct sk_buff *skb,
-		    __be16 src_port, __be16 dst_port, int *ignored)
+		    struct sk_buff *skb, __be16 src_port, __be16 dst_port,
+		    int *ignored, struct ip_vs_iphdr *iph)
 {
 	struct ip_vs_conn *cp = NULL;
-	struct ip_vs_iphdr iph;
 	struct ip_vs_dest *dest;
 	struct ip_vs_conn *ct;
 	__be16 dport = 0;		/* destination port to forward */
@@ -236,20 +235,18 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
 	union nf_inet_addr snet;	/* source network of the client,
 					   after masking */
 
-	ip_vs_fill_iph_skb(svc->af, skb, &iph);
-
 	/* Mask saddr with the netmask to adjust template granularity */
 #ifdef CONFIG_IP_VS_IPV6
 	if (svc->af == AF_INET6)
-		ipv6_addr_prefix(&snet.in6, &iph.saddr.in6, svc->netmask);
+		ipv6_addr_prefix(&snet.in6, &iph->saddr.in6, svc->netmask);
 	else
 #endif
-		snet.ip = iph.saddr.ip & svc->netmask;
+		snet.ip = iph->saddr.ip & svc->netmask;
 
 	IP_VS_DBG_BUF(6, "p-schedule: src %s:%u dest %s:%u "
 		      "mnet %s\n",
-		      IP_VS_DBG_ADDR(svc->af, &iph.saddr), ntohs(src_port),
-		      IP_VS_DBG_ADDR(svc->af, &iph.daddr), ntohs(dst_port),
+		      IP_VS_DBG_ADDR(svc->af, &iph->saddr), ntohs(src_port),
+		      IP_VS_DBG_ADDR(svc->af, &iph->daddr), ntohs(dst_port),
 		      IP_VS_DBG_ADDR(svc->af, &snet));
 
 	/*
@@ -266,8 +263,8 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
 	 * is created for other persistent services.
 	 */
 	{
-		int protocol = iph.protocol;
-		const union nf_inet_addr *vaddr = &iph.daddr;
+		int protocol = iph->protocol;
+		const union nf_inet_addr *vaddr = &iph->daddr;
 		__be16 vport = 0;
 
 		if (dst_port == svc->port) {
@@ -342,14 +339,14 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
 		dport = dest->port;
 
 	flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
-		 && iph.protocol == IPPROTO_UDP)?
+		 && iph->protocol == IPPROTO_UDP) ?
 		IP_VS_CONN_F_ONE_PACKET : 0;
 
 	/*
 	 *    Create a new connection according to the template
 	 */
-	ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol, &iph.saddr,
-			      src_port, &iph.daddr, dst_port, &param);
+	ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol, &iph->saddr,
+			      src_port, &iph->daddr, dst_port, &param);
 
 	cp = ip_vs_conn_new(&param, &dest->addr, dport, flags, dest, skb->mark);
 	if (cp == NULL) {
@@ -392,22 +389,20 @@ ip_vs_sched_persist(struct ip_vs_service *svc,
  */
 struct ip_vs_conn *
 ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
-	       struct ip_vs_proto_data *pd, int *ignored)
+	       struct ip_vs_proto_data *pd, int *ignored,
+	       struct ip_vs_iphdr *iph)
 {
 	struct ip_vs_protocol *pp = pd->pp;
 	struct ip_vs_conn *cp = NULL;
-	struct ip_vs_iphdr iph;
 	struct ip_vs_dest *dest;
 	__be16 _ports[2], *pptr;
 	unsigned int flags;
 
 	*ignored = 1;
-
 	/*
 	 * IPv6 frags, only the first hit here.
 	 */
-	ip_vs_fill_iph_skb(svc->af, skb, &iph);
-	pptr = frag_safe_skb_hp(skb, iph.len, sizeof(_ports), _ports, &iph);
+	pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
 	if (pptr == NULL)
 		return NULL;
 
@@ -427,7 +422,7 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
 	 *    Do not schedule replies from local real server.
 	 */
 	if ((!skb->dev || skb->dev->flags & IFF_LOOPBACK) &&
-	    (cp = pp->conn_in_get(svc->af, skb, &iph, iph.len, 1))) {
+	    (cp = pp->conn_in_get(svc->af, skb, iph, 1))) {
 		IP_VS_DBG_PKT(12, svc->af, pp, skb, 0,
 			      "Not scheduling reply for existing connection");
 		__ip_vs_conn_put(cp);
@@ -438,7 +433,8 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
 	 *    Persistent service
 	 */
 	if (svc->flags & IP_VS_SVC_F_PERSISTENT)
-		return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored);
+		return ip_vs_sched_persist(svc, skb, pptr[0], pptr[1], ignored,
+					   iph);
 
 	*ignored = 0;
 
@@ -460,7 +456,7 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
 	}
 
 	flags = (svc->flags & IP_VS_SVC_F_ONEPACKET
-		 && iph.protocol == IPPROTO_UDP)?
+		 && iph->protocol == IPPROTO_UDP) ?
 		IP_VS_CONN_F_ONE_PACKET : 0;
 
 	/*
@@ -469,9 +465,9 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
 	{
 		struct ip_vs_conn_param p;
 
-		ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol,
-				      &iph.saddr, pptr[0], &iph.daddr, pptr[1],
-				      &p);
+		ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol,
+				      &iph->saddr, pptr[0], &iph->daddr,
+				      pptr[1], &p);
 		cp = ip_vs_conn_new(&p, &dest->addr,
 				    dest->port ? dest->port : pptr[1],
 				    flags, dest, skb->mark);
@@ -500,18 +496,16 @@ ip_vs_schedule(struct ip_vs_service *svc, struct sk_buff *skb,
  *  no destination is available for a new connection.
  */
 int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
-		struct ip_vs_proto_data *pd)
+		struct ip_vs_proto_data *pd, struct ip_vs_iphdr *iph)
 {
 	__be16 _ports[2], *pptr;
-	struct ip_vs_iphdr iph;
 #ifdef CONFIG_SYSCTL
 	struct net *net;
 	struct netns_ipvs *ipvs;
 	int unicast;
 #endif
 
-	ip_vs_fill_iph_skb(svc->af, skb, &iph);
-	pptr = frag_safe_skb_hp(skb, iph.len, sizeof(_ports), _ports, &iph);
+	pptr = frag_safe_skb_hp(skb, iph->len, sizeof(_ports), _ports, iph);
 	if (pptr == NULL) {
 		ip_vs_service_put(svc);
 		return NF_DROP;
@@ -522,10 +516,10 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
 
 #ifdef CONFIG_IP_VS_IPV6
 	if (svc->af == AF_INET6)
-		unicast = ipv6_addr_type(&iph.daddr.in6) & IPV6_ADDR_UNICAST;
+		unicast = ipv6_addr_type(&iph->daddr.in6) & IPV6_ADDR_UNICAST;
 	else
 #endif
-		unicast = (inet_addr_type(net, iph.daddr.ip) == RTN_UNICAST);
+		unicast = (inet_addr_type(net, iph->daddr.ip) == RTN_UNICAST);
 
 	/* if it is fwmark-based service, the cache_bypass sysctl is up
 	   and the destination is a non-local unicast, then create
@@ -535,7 +529,7 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
 		int ret;
 		struct ip_vs_conn *cp;
 		unsigned int flags = (svc->flags & IP_VS_SVC_F_ONEPACKET &&
-				      iph.protocol == IPPROTO_UDP)?
+				      iph->protocol == IPPROTO_UDP) ?
 				      IP_VS_CONN_F_ONE_PACKET : 0;
 		union nf_inet_addr daddr =  { .all = { 0, 0, 0, 0 } };
 
@@ -545,9 +539,9 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
 		IP_VS_DBG(6, "%s(): create a cache_bypass entry\n", __func__);
 		{
 			struct ip_vs_conn_param p;
-			ip_vs_conn_fill_param(svc->net, svc->af, iph.protocol,
-					      &iph.saddr, pptr[0],
-					      &iph.daddr, pptr[1], &p);
+			ip_vs_conn_fill_param(svc->net, svc->af, iph->protocol,
+					      &iph->saddr, pptr[0],
+					      &iph->daddr, pptr[1], &p);
 			cp = ip_vs_conn_new(&p, &daddr, 0,
 					    IP_VS_CONN_F_BYPASS | flags,
 					    NULL, skb->mark);
@@ -562,7 +556,7 @@ int ip_vs_leave(struct ip_vs_service *svc, struct sk_buff *skb,
 		ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
 
 		/* transmit the first SYN packet */
-		ret = cp->packet_xmit(skb, cp, pd->pp);
+		ret = cp->packet_xmit(skb, cp, pd->pp, iph);
 		/* do not touch skb anymore */
 
 		atomic_inc(&cp->in_pkts);
@@ -908,7 +902,7 @@ static int ip_vs_out_icmp(struct sk_buff *skb, int *related,
 	ip_vs_fill_ip4hdr(cih, &ciph);
 	ciph.len += offset;
 	/* The embedded headers contain source and dest in reverse order */
-	cp = pp->conn_out_get(AF_INET, skb, &ciph, offset, 1);
+	cp = pp->conn_out_get(AF_INET, skb, &ciph, 1);
 	if (!cp)
 		return NF_ACCEPT;
 
@@ -919,7 +913,7 @@ static int ip_vs_out_icmp(struct sk_buff *skb, int *related,
 
 #ifdef CONFIG_IP_VS_IPV6
 static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related,
-			     unsigned int hooknum)
+			     unsigned int hooknum, struct ip_vs_iphdr *ipvsh)
 {
 	struct icmp6hdr	_icmph, *ic;
 	struct ipv6hdr _ip6h, *ip6h; /* The ip header contained within ICMP */
@@ -929,10 +923,6 @@ static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related,
 	union nf_inet_addr snet;
 	unsigned int writable;
 
-	struct ip_vs_iphdr ipvsh_stack;
-	struct ip_vs_iphdr *ipvsh = &ipvsh_stack;
-	ip_vs_fill_iph_skb(AF_INET6, skb, ipvsh);
-
 	*related = 1;
 	ic = frag_safe_skb_hp(skb, ipvsh->len, sizeof(_icmph), &_icmph, ipvsh);
 	if (ic == NULL)
@@ -976,7 +966,7 @@ static int ip_vs_out_icmp_v6(struct sk_buff *skb, int *related,
 		return NF_ACCEPT;
 
 	/* The embedded headers contain source and dest in reverse order */
-	cp = pp->conn_out_get(AF_INET6, skb, &ciph, ciph.len, 1);
+	cp = pp->conn_out_get(AF_INET6, skb, &ciph, 1);
 	if (!cp)
 		return NF_ACCEPT;
 
@@ -1016,17 +1006,17 @@ static inline int is_tcp_reset(const struct sk_buff *skb, int nh_len)
  */
 static unsigned int
 handle_response(int af, struct sk_buff *skb, struct ip_vs_proto_data *pd,
-		struct ip_vs_conn *cp, int ihl)
+		struct ip_vs_conn *cp, struct ip_vs_iphdr *iph)
 {
 	struct ip_vs_protocol *pp = pd->pp;
 
 	IP_VS_DBG_PKT(11, af, pp, skb, 0, "Outgoing packet");
 
-	if (!skb_make_writable(skb, ihl))
+	if (!skb_make_writable(skb, iph->len))
 		goto drop;
 
 	/* mangle the packet */
-	if (pp->snat_handler && !pp->snat_handler(skb, pp, cp))
+	if (pp->snat_handler && !pp->snat_handler(skb, pp, cp, iph))
 		goto drop;
 
 #ifdef CONFIG_IP_VS_IPV6
@@ -1125,7 +1115,7 @@ ip_vs_out(unsigned int hooknum, struct sk_buff *skb, int af)
 		if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
 			int related;
 			int verdict = ip_vs_out_icmp_v6(skb, &related,
-							hooknum);
+							hooknum, &iph);
 
 			if (related)
 				return verdict;
@@ -1160,10 +1150,10 @@ ip_vs_out(unsigned int hooknum, struct sk_buff *skb, int af)
 	/*
 	 * Check if the packet belongs to an existing entry
 	 */
-	cp = pp->conn_out_get(af, skb, &iph, iph.len, 0);
+	cp = pp->conn_out_get(af, skb, &iph, 0);
 
 	if (likely(cp))
-		return handle_response(af, skb, pd, cp, iph.len);
+		return handle_response(af, skb, pd, cp, &iph);
 	if (sysctl_nat_icmp_send(net) &&
 	    (pp->protocol == IPPROTO_TCP ||
 	     pp->protocol == IPPROTO_UDP ||
@@ -1375,7 +1365,7 @@ ip_vs_in_icmp(struct sk_buff *skb, int *related, unsigned int hooknum)
 	/* The embedded headers contain source and dest in reverse order.
 	 * For IPIP this is error for request, not for reply.
 	 */
-	cp = pp->conn_in_get(AF_INET, skb, &ciph, offset, ipip ? 0 : 1);
+	cp = pp->conn_in_get(AF_INET, skb, &ciph, ipip ? 0 : 1);
 	if (!cp)
 		return NF_ACCEPT;
 
@@ -1444,7 +1434,7 @@ ignore_ipip:
 	ip_vs_in_stats(cp, skb);
 	if (IPPROTO_TCP == cih->protocol || IPPROTO_UDP == cih->protocol)
 		offset += 2 * sizeof(__u16);
-	verdict = ip_vs_icmp_xmit(skb, cp, pp, offset, hooknum);
+	verdict = ip_vs_icmp_xmit(skb, cp, pp, offset, hooknum, &ciph);
 
 out:
 	__ip_vs_conn_put(cp);
@@ -1453,8 +1443,8 @@ out:
 }
 
 #ifdef CONFIG_IP_VS_IPV6
-static int
-ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
+static int ip_vs_in_icmp_v6(struct sk_buff *skb, int *related,
+			    unsigned int hooknum, struct ip_vs_iphdr *iph)
 {
 	struct net *net = NULL;
 	struct ipv6hdr _ip6h, *ip6h;
@@ -1465,10 +1455,6 @@ ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
 	struct ip_vs_proto_data *pd;
 	unsigned int offs_ciph, writable, verdict;
 
-	struct ip_vs_iphdr iph_stack;
-	struct ip_vs_iphdr *iph = &iph_stack;
-	ip_vs_fill_iph_skb(AF_INET6, skb, iph);
-
 	*related = 1;
 
 	ic = frag_safe_skb_hp(skb, iph->len, sizeof(_icmph), &_icmph, iph);
@@ -1525,7 +1511,7 @@ ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
 	/* The embedded headers contain source and dest in reverse order
 	 * if not from localhost
 	 */
-	cp = pp->conn_in_get(AF_INET6, skb, &ciph, ciph.len,
+	cp = pp->conn_in_get(AF_INET6, skb, &ciph,
 			     (hooknum == NF_INET_LOCAL_OUT) ? 0 : 1);
 
 	if (!cp)
@@ -1546,7 +1532,7 @@ ip_vs_in_icmp_v6(struct sk_buff *skb, int *related, unsigned int hooknum)
 	    IPPROTO_SCTP == ciph.protocol)
 		writable += 2 * sizeof(__u16); /* Also mangle ports */
 
-	verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, writable, hooknum);
+	verdict = ip_vs_icmp_xmit_v6(skb, cp, pp, writable, hooknum, &ciph);
 
 	__ip_vs_conn_put(cp);
 
@@ -1616,7 +1602,8 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
 		}
 		if (unlikely(iph.protocol == IPPROTO_ICMPV6)) {
 			int related;
-			int verdict = ip_vs_in_icmp_v6(skb, &related, hooknum);
+			int verdict = ip_vs_in_icmp_v6(skb, &related, hooknum,
+						       &iph);
 
 			if (related)
 				return verdict;
@@ -1639,8 +1626,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
 	/*
 	 * Check if the packet belongs to an existing connection entry
 	 */
-	cp = pp->conn_in_get(af, skb, &iph, iph.len, 0);
-
+	cp = pp->conn_in_get(af, skb, &iph, 0);
 	if (unlikely(!cp) && !iph.fragoffs) {
 		/* No (second) fragments need to enter here, as nf_defrag_ipv6
 		 * replayed fragment zero will already have created the cp
@@ -1648,7 +1634,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
 		int v;
 
 		/* Schedule and create new connection entry into &cp */
-		if (!pp->conn_schedule(af, skb, pd, &v, &cp))
+		if (!pp->conn_schedule(af, skb, pd, &v, &cp, &iph))
 			return v;
 	}
 
@@ -1686,7 +1672,7 @@ ip_vs_in(unsigned int hooknum, struct sk_buff *skb, int af)
 	ip_vs_in_stats(cp, skb);
 	ip_vs_set_state(cp, IP_VS_DIR_INPUT, skb, pd);
 	if (cp->packet_xmit)
-		ret = cp->packet_xmit(skb, cp, pp);
+		ret = cp->packet_xmit(skb, cp, pp, &iph);
 		/* do not touch skb anymore */
 	else {
 		IP_VS_DBG_RL("warning: packet_xmit is null");
@@ -1860,7 +1846,7 @@ ip_vs_forward_icmp_v6(unsigned int hooknum, struct sk_buff *skb,
 	if (!net_ipvs(net)->enable)
 		return NF_ACCEPT;
 
-	return ip_vs_in_icmp_v6(skb, &r, hooknum);
+	return ip_vs_in_icmp_v6(skb, &r, hooknum, &iphdr);
 }
 #endif