diff options
| author | Nicolas Dichtel <nicolas.dichtel@6wind.com> | 2020-01-13 09:32:46 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-05 14:18:23 +0000 |
| commit | 9c8c51176e9d3035f6e89b6664b4dd67a0873cbf (patch) | |
| tree | 63b46645ad0247dd7b9dac187f389f3a0ea32142 /net | |
| parent | adafa3c54b4ad81622a4508ed2c29cb1da46801b (diff) | |
vti[6]: fix packet tx through bpf_redirect()
[ Upstream commit 95224166a9032ff5d08fca633d37113078ce7d01 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/ip_vti.c | 13 | ||||
| -rw-r--r-- | net/ipv6/ip6_vti.c | 13 |
2 files changed, 22 insertions, 4 deletions
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c index 08c15dd42d93..59384ffe89f7 100644 --- a/net/ipv4/ip_vti.c +++ b/net/ipv4/ip_vti.c @@ -208,8 +208,17 @@ static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev, int mtu; if (!dst) { - dev->stats.tx_carrier_errors++; - goto tx_error_icmp; + 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); diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c index 557fe3880a3f..396a0f61f5f8 100644 --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -453,8 +453,17 @@ vti6_xmit(struct sk_buff *skb, struct net_device *dev, struct flowi *fl) int err = -1; int mtu; - if (!dst) - goto tx_err_link_failure; + 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); |