vti[6]: fix packet tx through bpf_redirect() (95224166) · Commits · 戴 / test

With an ebpf program that redirects packets through a vti[6] interface, the packets are dropped because no dst is attached. This could also be reproduced with an AF_PACKET socket, with the following python script (vti1 is an ip_vti interface): import socket send_s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, 0) # scapy # p = IP(src='10.100.0.2', dst='10.200.0.1')/ICMP(type='echo-request') # raw(p) req = b'E\x00\x00\x1c\x00\x01\x00\x00@\x01e\xb2\nd\x00\x02\n\xc8\x00\x01\x08\x00\xf7\xff\x00\x00\x00\x00' send_s.sendto(req, ('vti1', 0x800, 0, 0)) Signed-off-by:

Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by:

Steffen Klassert <steffen.klassert@secunet.com>

net/ipv4/ip_vti.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -187,9 +187,18 @@ 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)) {
		dev->stats.tx_carrier_errors++;
		goto tx_error_icmp;
		}
		dst = &rt->dst;
		skb_dst_set(skb, dst);
		}

		dst_hold(dst);
		dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);

net/ipv6/ip6_vti.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -449,8 +449,17 @@ vti6_xmit(struct sk_buff skb, struct net_device dev, struct flowi *fl)
		int err = -1;
		int mtu;

		if (!dst)
		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;
		goto tx_err_link_failure;
		}
		skb_dst_set(skb, dst);
		}

		dst_hold(dst);
		dst = xfrm_lookup(t->net, dst, fl, NULL, 0);

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