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| author | Nicolas Dichtel <nicolas.dichtel@6wind.com> | 2020-01-13 09:32:46 +0100 |
|---|---|---|
| committer | Steffen Klassert <steffen.klassert@secunet.com> | 2020-01-14 08:55:38 +0100 |
| commit | 95224166a9032ff5d08fca633d37113078ce7d01 (patch) | |
| tree | 21181101c0a61e77ab1082dc80fd028249719eb9 /net/ipv4/ip_vti.c | |
| parent | a112adafcb47760feff959ee1ecd10b74d2c5467 (diff) | |
| download | lwn-95224166a9032ff5d08fca633d37113078ce7d01.tar.gz lwn-95224166a9032ff5d08fca633d37113078ce7d01.zip | |
vti[6]: fix packet tx through bpf_redirect()
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>
Diffstat (limited to 'net/ipv4/ip_vti.c')
| -rw-r--r-- | net/ipv4/ip_vti.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/net/ipv4/ip_vti.c b/net/ipv4/ip_vti.c index e90b600c7a25..37cddd18f282 100644 --- a/net/ipv4/ip_vti.c +++ b/net/ipv4/ip_vti.c @@ -187,8 +187,17 @@ 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); |