net/ipv6: Pass skb to route lookup

IPv6 does path selection for multipath routes deep in the lookup
functions. The next patch adds L4 hash option and needs the skb
for the forward path. To get the skb to the relevant FIB lookup
functions it needs to go through the fib rules layer, so add a
lookup_data argument to the fib_lookup_arg struct.

Signed-off-by: David Ahern <[e-mail]>
Reviewed-by: Ido Schimmel <[e-mail]>
Reviewed-by: Nikolay Aleksandrov <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/infiniband/core/cma.c

···
 			   IPV6_ADDR_LINKLOCAL;
 	struct rt6_info *rt = rt6_lookup(dev_net(net_dev), &dst_addr->sin6_addr,
 					 &src_addr->sin6_addr, net_dev->ifindex,
-					 strict);
+					 NULL, strict);
 	bool ret;
 
 	if (!rt)

drivers/net/ipvlan/ipvlan_core.c

···
 		};
 
 		skb_dst_drop(skb);
-		dst = ip6_route_input_lookup(dev_net(sdev), sdev, &fl6, flags);
+		dst = ip6_route_input_lookup(dev_net(sdev), sdev, &fl6,
+					     skb, flags);
 		skb_dst_set(skb, dst);
 		break;
 	}

drivers/net/vrf.c

···
 					     const struct net_device *dev,
 					     struct flowi6 *fl6,
 					     int ifindex,
+					     const struct sk_buff *skb,
 					     int flags)
 {
 	struct net_vrf *vrf = netdev_priv(dev);
···
 	if (!table)
 		return NULL;
 
-	return ip6_pol_route(net, table, ifindex, fl6, flags);
+	return ip6_pol_route(net, table, ifindex, fl6, skb, flags);
 }
 
 static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
···
 	struct net *net = dev_net(vrf_dev);
 	struct rt6_info *rt6;
 
-	rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex,
+	rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
 				   RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
 	if (unlikely(!rt6))
 		return;
···
 	if (!ipv6_addr_any(&fl6->saddr))
 		flags |= RT6_LOOKUP_F_HAS_SADDR;
 
-	rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, flags);
+	rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
 	if (rt)
 		dst = &rt->dst;
 

include/net/fib_rules.h

···
 
 struct fib_lookup_arg {
 	void			*lookup_ptr;
+	const void		*lookup_data;
 	void			*result;
 	struct fib_rule		*rule;
 	u32			table;

include/net/ip6_fib.h

···
 
 typedef struct rt6_info *(*pol_lookup_t)(struct net *,
 					 struct fib6_table *,
-					 struct flowi6 *, int);
+					 struct flowi6 *,
+					 const struct sk_buff *, int);
 
 struct fib6_entry_notifier_info {
 	struct fib_notifier_info info; /* must be first */
···
 struct fib6_table *fib6_get_table(struct net *net, u32 id);
 struct fib6_table *fib6_new_table(struct net *net, u32 id);
 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
+				   const struct sk_buff *skb,
 				   int flags, pol_lookup_t lookup);
 
 struct fib6_node *fib6_lookup(struct fib6_node *root,

include/net/ip6_route.h

···
 void ip6_route_input(struct sk_buff *skb);
 struct dst_entry *ip6_route_input_lookup(struct net *net,
 					 struct net_device *dev,
-					 struct flowi6 *fl6, int flags);
+					 struct flowi6 *fl6,
+					 const struct sk_buff *skb, int flags);
 
 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
 					 struct flowi6 *fl6, int flags);
···
 }
 
 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
-				   int flags);
+				   const struct sk_buff *skb, int flags);
 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
-			       int ifindex, struct flowi6 *fl6, int flags);
+			       int ifindex, struct flowi6 *fl6,
+			       const struct sk_buff *skb, int flags);
 
 void ip6_route_init_special_entries(void);
 int ip6_route_init(void);
···
 }
 
 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
-			    const struct in6_addr *saddr, int oif, int flags);
+			    const struct in6_addr *saddr, int oif,
+			    const struct sk_buff *skb, int flags);
 u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb,
 		       struct flow_keys *hkeys);
 

net/ipv6/anycast.c

···
 	if (ifindex == 0) {
 		struct rt6_info *rt;
 
-		rt = rt6_lookup(net, addr, NULL, 0, 0);
+		rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
 		if (rt) {
 			dev = rt->dst.dev;
 			ip6_rt_put(rt);

net/ipv6/fib6_rules.c

···
 }
 
 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
+				   const struct sk_buff *skb,
 				   int flags, pol_lookup_t lookup)
 {
 	if (net->ipv6.fib6_has_custom_rules) {
 		struct fib_lookup_arg arg = {
 			.lookup_ptr = lookup,
+			.lookup_data = skb,
 			.flags = FIB_LOOKUP_NOREF,
 		};
 
···
 	} else {
 		struct rt6_info *rt;
 
-		rt = lookup(net, net->ipv6.fib6_local_tbl, fl6, flags);
+		rt = lookup(net, net->ipv6.fib6_local_tbl, fl6, skb, flags);
 		if (rt != net->ipv6.ip6_null_entry && rt->dst.error != -EAGAIN)
 			return &rt->dst;
 		ip6_rt_put(rt);
-		rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
+		rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
 		if (rt->dst.error != -EAGAIN)
 			return &rt->dst;
 		ip6_rt_put(rt);
···
 		goto out;
 	}
 
-	rt = lookup(net, table, flp6, flags);
+	rt = lookup(net, table, flp6, arg->lookup_data, flags);
 	if (rt != net->ipv6.ip6_null_entry) {
 		struct fib6_rule *r = (struct fib6_rule *)rule;
 

net/ipv6/icmp.c

···
 	skb_pull(skb2, nhs);
 	skb_reset_network_header(skb2);
 
-	rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, 0);
+	rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0,
+			skb, 0);
 
 	if (rt && rt->dst.dev)
 		skb2->dev = rt->dst.dev;

net/ipv6/ip6_fib.c

···
 }
 
 struct dst_entry *fib6_rule_lookup(struct net *net, struct flowi6 *fl6,
+				   const struct sk_buff *skb,
 				   int flags, pol_lookup_t lookup)
 {
 	struct rt6_info *rt;
 
-	rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, flags);
+	rt = lookup(net, net->ipv6.fib6_main_tbl, fl6, skb, flags);
 	if (rt->dst.error == -EAGAIN) {
 		ip6_rt_put(rt);
 		rt = net->ipv6.ip6_null_entry;

net/ipv6/ip6_gre.c

···
 
 		struct rt6_info *rt = rt6_lookup(t->net,
 						 &p->raddr, &p->laddr,
-						 p->link, strict);
+						 p->link, NULL, strict);
 
 		if (!rt)
 			return;

net/ipv6/ip6_tunnel.c

···
 
 		/* Try to guess incoming interface */
 		rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr,
-				NULL, 0, 0);
+				NULL, 0, skb2, 0);
 
 		if (rt && rt->dst.dev)
 			skb2->dev = rt->dst.dev;
···
 
 		struct rt6_info *rt = rt6_lookup(t->net,
 						 &p->raddr, &p->laddr,
-						 p->link, strict);
+						 p->link, NULL, strict);
 
 		if (!rt)
 			return;

net/ipv6/ip6_vti.c

···
 			      (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL));
 		struct rt6_info *rt = rt6_lookup(t->net,
 						 &p->raddr, &p->laddr,
-						 p->link, strict);
+						 p->link, NULL, strict);
 
 		if (rt)
 			tdev = rt->dst.dev;

net/ipv6/mcast.c

···
 
 	if (ifindex == 0) {
 		struct rt6_info *rt;
-		rt = rt6_lookup(net, addr, NULL, 0, 0);
+		rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
 		if (rt) {
 			dev = rt->dst.dev;
 			ip6_rt_put(rt);
···
 	struct inet6_dev *idev = NULL;
 
 	if (ifindex == 0) {
-		struct rt6_info *rt = rt6_lookup(net, group, NULL, 0, 0);
+		struct rt6_info *rt = rt6_lookup(net, group, NULL, 0, NULL, 0);
 
 		if (rt) {
 			dev = rt->dst.dev;

net/ipv6/netfilter/ip6t_rpfilter.c

···
 		lookup_flags |= RT6_LOOKUP_F_IFACE;
 	}
 
-	rt = (void *) ip6_route_lookup(net, &fl6, lookup_flags);
+	rt = (void *)ip6_route_lookup(net, &fl6, skb, lookup_flags);
 	if (rt->dst.error)
 		goto out;
 

net/ipv6/netfilter/nft_fib_ipv6.c

···
 
 	*dest = 0;
  again:
-	rt = (void *)ip6_route_lookup(nft_net(pkt), &fl6, lookup_flags);
+	rt = (void *)ip6_route_lookup(nft_net(pkt), &fl6, pkt->skb,
+				      lookup_flags);
 	if (rt->dst.error)
 		goto put_rt_err;
 

net/ipv6/route.c

···
 
 static struct rt6_info *rt6_multipath_select(struct rt6_info *match,
 					     struct flowi6 *fl6, int oif,
+					     const struct sk_buff *skb,
 					     int strict)
 {
 	struct rt6_info *sibling, *next_sibling;
···
 	 * case it will always be non-zero. Otherwise now is the time to do it.
 	 */
 	if (!fl6->mp_hash)
-		fl6->mp_hash = rt6_multipath_hash(fl6, NULL, NULL);
+		fl6->mp_hash = rt6_multipath_hash(fl6, skb, NULL);
 
 	if (fl6->mp_hash <= atomic_read(&match->rt6i_nh_upper_bound))
 		return match;
···
 
 static struct rt6_info *ip6_pol_route_lookup(struct net *net,
 					     struct fib6_table *table,
-					     struct flowi6 *fl6, int flags)
+					     struct flowi6 *fl6,
+					     const struct sk_buff *skb,
+					     int flags)
 {
 	struct rt6_info *rt, *rt_cache;
 	struct fib6_node *fn;
···
 		rt = rt6_device_match(net, rt, &fl6->saddr,
 				      fl6->flowi6_oif, flags);
 		if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
-			rt = rt6_multipath_select(rt, fl6,
-						  fl6->flowi6_oif, flags);
+			rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif,
+						  skb, flags);
 	}
 	if (rt == net->ipv6.ip6_null_entry) {
 		fn = fib6_backtrack(fn, &fl6->saddr);
···
 }
 
 struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
-				    int flags)
+				   const struct sk_buff *skb, int flags)
 {
-	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_lookup);
+	return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
 }
 EXPORT_SYMBOL_GPL(ip6_route_lookup);
 
 struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
-			    const struct in6_addr *saddr, int oif, int strict)
+			    const struct in6_addr *saddr, int oif,
+			    const struct sk_buff *skb, int strict)
 {
 	struct flowi6 fl6 = {
 		.flowi6_oif = oif,
···
 		flags |= RT6_LOOKUP_F_HAS_SADDR;
 	}
 
-	dst = fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_lookup);
+	dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
 	if (dst->error == 0)
 		return (struct rt6_info *) dst;
 
···
 }
 
 struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
-			       int oif, struct flowi6 *fl6, int flags)
+			       int oif, struct flowi6 *fl6,
+			       const struct sk_buff *skb, int flags)
 {
 	struct fib6_node *fn, *saved_fn;
 	struct rt6_info *rt, *rt_cache;
···
 redo_rt6_select:
 	rt = rt6_select(net, fn, oif, strict);
 	if (rt->rt6i_nsiblings)
-		rt = rt6_multipath_select(rt, fl6, oif, strict);
+		rt = rt6_multipath_select(rt, fl6, oif, skb, strict);
 	if (rt == net->ipv6.ip6_null_entry) {
 		fn = fib6_backtrack(fn, &fl6->saddr);
 		if (fn)
···
 }
 EXPORT_SYMBOL_GPL(ip6_pol_route);
 
-static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *table,
-					    struct flowi6 *fl6, int flags)
+static struct rt6_info *ip6_pol_route_input(struct net *net,
+					    struct fib6_table *table,
+					    struct flowi6 *fl6,
+					    const struct sk_buff *skb,
+					    int flags)
 {
-	return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags);
+	return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
 }
 
 struct dst_entry *ip6_route_input_lookup(struct net *net,
 					 struct net_device *dev,
-					 struct flowi6 *fl6, int flags)
+					 struct flowi6 *fl6,
+					 const struct sk_buff *skb,
+					 int flags)
 {
 	if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
 		flags |= RT6_LOOKUP_F_IFACE;
 
-	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_input);
+	return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
 }
 EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
 
···
 	if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
 		fl6.mp_hash = rt6_multipath_hash(&fl6, skb, flkeys);
 	skb_dst_drop(skb);
-	skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags));
+	skb_dst_set(skb,
+		    ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags));
 }
 
-static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table,
-					     struct flowi6 *fl6, int flags)
+static struct rt6_info *ip6_pol_route_output(struct net *net,
+					     struct fib6_table *table,
+					     struct flowi6 *fl6,
+					     const struct sk_buff *skb,
+					     int flags)
 {
-	return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags);
+	return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
 }
 
 struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
···
 	else if (sk)
 		flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
 
-	return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output);
+	return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
 }
 EXPORT_SYMBOL_GPL(ip6_route_output_flags);
 
···
 static struct rt6_info *__ip6_route_redirect(struct net *net,
 					     struct fib6_table *table,
 					     struct flowi6 *fl6,
+					     const struct sk_buff *skb,
 					     int flags)
 {
 	struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
···
 };
 
 static struct dst_entry *ip6_route_redirect(struct net *net,
-					const struct flowi6 *fl6,
-					const struct in6_addr *gateway)
+					    const struct flowi6 *fl6,
+					    const struct sk_buff *skb,
+					    const struct in6_addr *gateway)
 {
 	int flags = RT6_LOOKUP_F_HAS_SADDR;
 	struct ip6rd_flowi rdfl;
···
 	rdfl.fl6 = *fl6;
 	rdfl.gateway = *gateway;
 
-	return fib6_rule_lookup(net, &rdfl.fl6,
+	return fib6_rule_lookup(net, &rdfl.fl6, skb,
 				flags, __ip6_route_redirect);
 }
 
···
 	fl6.flowlabel = ip6_flowinfo(iph);
 	fl6.flowi6_uid = uid;
 
-	dst = ip6_route_redirect(net, &fl6, &ipv6_hdr(skb)->saddr);
+	dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
 	rt6_do_redirect(dst, NULL, skb);
 	dst_release(dst);
 }
···
 	fl6.saddr = iph->daddr;
 	fl6.flowi6_uid = sock_net_uid(net, NULL);
 
-	dst = ip6_route_redirect(net, &fl6, &iph->saddr);
+	dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
 	rt6_do_redirect(dst, NULL, skb);
 	dst_release(dst);
 }
···
 		flags |= RT6_LOOKUP_F_HAS_SADDR;
 
 	flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
-	rt = ip6_pol_route(net, table, cfg->fc_ifindex, &fl6, flags);
+	rt = ip6_pol_route(net, table, cfg->fc_ifindex, &fl6, NULL, flags);
 
 	/* if table lookup failed, fall back to full lookup */
 	if (rt == net->ipv6.ip6_null_entry) {
···
 	}
 
 	if (!grt)
-		grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
+		grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, NULL, 1);
 
 	if (!grt)
 		goto out;
···
 		if (!ipv6_addr_any(&fl6.saddr))
 			flags |= RT6_LOOKUP_F_HAS_SADDR;
 
-		dst = ip6_route_input_lookup(net, dev, &fl6, flags);
+		dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
 
 		rcu_read_unlock();
 	} else {

net/ipv6/seg6_local.c

···
 		fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
 
 	if (!tbl_id) {
-		dst = ip6_route_input_lookup(net, skb->dev, &fl6, flags);
+		dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags);
 	} else {
 		struct fib6_table *table;
 
···
 		if (!table)
 			goto out;
 
-		rt = ip6_pol_route(net, table, 0, &fl6, flags);
+		rt = ip6_pol_route(net, table, 0, &fl6, skb, flags);
 		dst = &rt->dst;
 	}