Subject: [PATCH 2/8] vti[6]: fix packet tx through bpf_redirect() in XinY cases

From: Steffen Klassert <[email-masked]>
Date: Fri, 27 Mar 2020 09:10:01 +0100

From: Nicolas Dichtel <[email-masked]>

I forgot the 4in6/6in4 cases in my previous patch. Let's fix them.

Fixes: 95224166a903 ("vti[6]: fix packet tx through bpf_redirect()")
Signed-off-by: Nicolas Dichtel <[email-masked]>
Signed-off-by: Steffen Klassert <[email-masked]>
---
 net/ipv4/Kconfig   |  1 +
 net/ipv4/ip_vti.c  | 38 ++++++++++++++++++++++++++++++--------
 net/ipv6/ip6_vti.c | 32 +++++++++++++++++++++++++-------
 3 files changed, 56 insertions(+), 15 deletions(-)

diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig
index f96bd489b362..6490b845e17b 100644
--- a/net/ipv4/Kconfig
+++ b/net/ipv4/Kconfig
@@ -303,6 +303,7 @@ config SYN_COOKIES
 
 config NET_IPVTI
 	tristate "Virtual (secure) IP: tunneling"
+	depends on IPV6 || IPV6=n
 	select INET_TUNNEL
 	select NET_IP_TUNNEL
 	select XFRM
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c
index 37cddd18f282..1b4e6f298648 100644
--- a/net/ipv4/ip_vti.c
+++ b/net/ipv4/ip_vti.c
@@ -187,17 +187,39 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 	int mtu;
 
 	if (!dst) {
-		struct rtable *rt;
-
-		fl->u.ip4.flowi4_oif = dev->ifindex;
-		fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
-		rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
-		if (IS_ERR(rt)) {
+		switch (skb->protocol) {
+		case htons(ETH_P_IP): {
+			struct rtable *rt;
+
+			fl->u.ip4.flowi4_oif = dev->ifindex;
+			fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
+			rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
+			if (IS_ERR(rt)) {
+				dev->stats.tx_carrier_errors++;
+				goto tx_error_icmp;
+			}
+			dst = &rt->dst;
+			skb_dst_set(skb, dst);
+			break;
+		}
+#if IS_ENABLED(CONFIG_IPV6)
+		case htons(ETH_P_IPV6):
+			fl->u.ip6.flowi6_oif = dev->ifindex;
+			fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
+			dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6);
+			if (dst->error) {
+				dst_release(dst);
+				dst = NULL;
+				dev->stats.tx_carrier_errors++;
+				goto tx_error_icmp;
+			}
+			skb_dst_set(skb, dst);
+			break;
+#endif
+		default:
 			dev->stats.tx_carrier_errors++;
 			goto tx_error_icmp;
 		}
-		dst = &rt->dst;
-		skb_dst_set(skb, dst);
 	}
 
 	dst_hold(dst);
diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c
index 524006aa0d78..56e642efefff 100644
--- a/net/ipv6/ip6_vti.c
+++ b/net/ipv6/ip6_vti.c
@@ -450,15 +450,33 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 	int mtu;
 
 	if (!dst) {
-		fl->u.ip6.flowi6_oif = dev->ifindex;
-		fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
-		dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6);
-		if (dst->error) {
-			dst_release(dst);
-			dst = NULL;
+		switch (skb->protocol) {
+		case htons(ETH_P_IP): {
+			struct rtable *rt;
+
+			fl->u.ip4.flowi4_oif = dev->ifindex;
+			fl->u.ip4.flowi4_flags |= FLOWI_FLAG_ANYSRC;
+			rt = __ip_route_output_key(dev_net(dev), &fl->u.ip4);
+			if (IS_ERR(rt))
+				goto tx_err_link_failure;
+			dst = &rt->dst;
+			skb_dst_set(skb, dst);
+			break;
+		}
+		case htons(ETH_P_IPV6):
+			fl->u.ip6.flowi6_oif = dev->ifindex;
+			fl->u.ip6.flowi6_flags |= FLOWI_FLAG_ANYSRC;
+			dst = ip6_route_output(dev_net(dev), NULL, &fl->u.ip6);
+			if (dst->error) {
+				dst_release(dst);
+				dst = NULL;
+				goto tx_err_link_failure;
+			}
+			skb_dst_set(skb, dst);
+			break;
+		default:
 			goto tx_err_link_failure;
 		}
-		skb_dst_set(skb, dst);
 	}
 
 	dst_hold(dst);
-- 
2.17.1