vti[6]: fix packet tx through bpf_redirect()
authorNicolas Dichtel <nicolas.dichtel@6wind.com>
Mon, 13 Jan 2020 08:32:46 +0000 (09:32 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 5 Feb 2020 13:05:51 +0000 (13:05 +0000)
commitbe914e09066dff6a9506a45ef99c813f58997f72
tree192a6e81e52bc7004a23c5ffeae014829dc16e9b
parenta1832a2a897cf6141eb6b278bff79d975f3fb873
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>
net/ipv4/ip_vti.c
net/ipv6/ip6_vti.c