ipvlan: decouple l3s mode dependencies from other modes

Right now ipvlan has a hard dependency on CONFIG_NETFILTER and
otherwise it cannot be built. However, the only ipvlan operation
mode that actually depends on netfilter is l3s, everything else
is independent of it. Break this hard dependency such that users
are able to use ipvlan l3 mode on systems where netfilter is not
compiled in.

Therefore, this adds a hidden CONFIG_IPVLAN_L3S bool which is
defaulting to y when CONFIG_NETFILTER is set in order to retain
existing behavior for l3s. All l3s related code is refactored
into ipvlan_l3s.c that is compiled in when enabled.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Martynas Pumputis <m@lambda.lt>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 98 deletions

diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c
index 1a8132eb2a3e..e0f5bc82b10c 100644
--- a/drivers/net/ipvlan/ipvlan_core.c
+++ b/drivers/net/ipvlan/ipvlan_core.c
@@ -138,7 +138,7 @@ bool ipvlan_addr_busy(struct ipvl_port *port, void *iaddr, bool is_v6)
 	return ret;
 }
 
-static void *ipvlan_get_L3_hdr(struct ipvl_port *port, struct sk_buff *skb, int *type)
+void *ipvlan_get_L3_hdr(struct ipvl_port *port, struct sk_buff *skb, int *type)
 {
 	void *lyr3h = NULL;
 
@@ -355,9 +355,8 @@ out:
 	return ret;
 }
 
-static struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port,
-					    void *lyr3h, int addr_type,
-					    bool use_dest)
+struct ipvl_addr *ipvlan_addr_lookup(struct ipvl_port *port, void *lyr3h,
+				     int addr_type, bool use_dest)
 {
 	struct ipvl_addr *addr = NULL;
 
@@ -647,7 +646,9 @@ int ipvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
 	case IPVLAN_MODE_L2:
 		return ipvlan_xmit_mode_l2(skb, dev);
 	case IPVLAN_MODE_L3:
+#ifdef CONFIG_IPVLAN_L3S
 	case IPVLAN_MODE_L3S:
+#endif
 		return ipvlan_xmit_mode_l3(skb, dev);
 	}
 
@@ -743,8 +744,10 @@ rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
 		return ipvlan_handle_mode_l2(pskb, port);
 	case IPVLAN_MODE_L3:
 		return ipvlan_handle_mode_l3(pskb, port);
+#ifdef CONFIG_IPVLAN_L3S
 	case IPVLAN_MODE_L3S:
 		return RX_HANDLER_PASS;
+#endif
 	}
 
 	/* Should not reach here */
@@ -753,97 +756,3 @@ rx_handler_result_t ipvlan_handle_frame(struct sk_buff **pskb)
 	kfree_skb(skb);
 	return RX_HANDLER_CONSUMED;
 }
-
-static struct ipvl_addr *ipvlan_skb_to_addr(struct sk_buff *skb,
-					    struct net_device *dev)
-{
-	struct ipvl_addr *addr = NULL;
-	struct ipvl_port *port;
-	void *lyr3h;
-	int addr_type;
-
-	if (!dev || !netif_is_ipvlan_port(dev))
-		goto out;
-
-	port = ipvlan_port_get_rcu(dev);
-	if (!port || port->mode != IPVLAN_MODE_L3S)
-		goto out;
-
-	lyr3h = ipvlan_get_L3_hdr(port, skb, &addr_type);
-	if (!lyr3h)
-		goto out;
-
-	addr = ipvlan_addr_lookup(port, lyr3h, addr_type, true);
-out:
-	return addr;
-}
-
-struct sk_buff *ipvlan_l3_rcv(struct net_device *dev, struct sk_buff *skb,
-			      u16 proto)
-{
-	struct ipvl_addr *addr;
-	struct net_device *sdev;
-
-	addr = ipvlan_skb_to_addr(skb, dev);
-	if (!addr)
-		goto out;
-
-	sdev = addr->master->dev;
-	switch (proto) {
-	case AF_INET:
-	{
-		int err;
-		struct iphdr *ip4h = ip_hdr(skb);
-
-		err = ip_route_input_noref(skb, ip4h->daddr, ip4h->saddr,
-					   ip4h->tos, sdev);
-		if (unlikely(err))
-			goto out;
-		break;
-	}
-#if IS_ENABLED(CONFIG_IPV6)
-	case AF_INET6:
-	{
-		struct dst_entry *dst;
-		struct ipv6hdr *ip6h = ipv6_hdr(skb);
-		int flags = RT6_LOOKUP_F_HAS_SADDR;
-		struct flowi6 fl6 = {
-			.flowi6_iif   = sdev->ifindex,
-			.daddr        = ip6h->daddr,
-			.saddr        = ip6h->saddr,
-			.flowlabel    = ip6_flowinfo(ip6h),
-			.flowi6_mark  = skb->mark,
-			.flowi6_proto = ip6h->nexthdr,
-		};
-
-		skb_dst_drop(skb);
-		dst = ip6_route_input_lookup(dev_net(sdev), sdev, &fl6,
-					     skb, flags);
-		skb_dst_set(skb, dst);
-		break;
-	}
-#endif
-	default:
-		break;
-	}
-
-out:
-	return skb;
-}
-
-unsigned int ipvlan_nf_input(void *priv, struct sk_buff *skb,
-			     const struct nf_hook_state *state)
-{
-	struct ipvl_addr *addr;
-	unsigned int len;
-
-	addr = ipvlan_skb_to_addr(skb, skb->dev);
-	if (!addr)
-		goto out;
-
-	skb->dev = addr->master->dev;
-	len = skb->len + ETH_HLEN;
-	ipvlan_count_rx(addr->master, len, true, false);
-out:
-	return NF_ACCEPT;
-}