vti[6]: fix packet tx through bpf_redirect() in XinY cases

BugLink: https://bugs.launchpad.net/bugs/1873852

commit f1ed1026 upstream.

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

Fixes: 95224166 ("vti[6]: fix packet tx through bpf_redirect()")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>

net/ipv4/Kconfig

@@ -298,6 +298,7 @@ config SYN_COOKIES
 
 config NET_IPVTI
 	tristate "Virtual (secure) IP: tunneling"
+	depends on IPV6 || IPV6=n
 	select INET_TUNNEL
 	select NET_IP_TUNNEL
 	depends on INET_XFRM_MODE_TUNNEL

net/ipv4/ip_vti.c

@@ -195,6 +195,8 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 	int err;
 
 	if (!dst) {
+		switch (skb->protocol) {
+		case htons(ETH_P_IP): {
 			struct rtable *rt;
 
 			fl->u.ip4.flowi4_oif = dev->ifindex;
@@ -206,6 +208,26 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 			}
 			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_hold(dst);

net/ipv6/ip6_vti.c

@@ -442,6 +442,20 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 	int mtu;
 
 	if (!dst) {
+		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);
@@ -451,6 +465,10 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl)
 				goto tx_err_link_failure;
 			}
 			skb_dst_set(skb, dst);
+			break;
+		default:
+			goto tx_err_link_failure;
+		}
 	}
 
 	dst_hold(dst);