❦ 15 juillet 2018 19:12 -0700, Mahesh Bandewar <mah...@bandewar.net>:
> Commit b89f04c61efe ("bonding: deliver link-local packets with
> skb->dev set to link that packets arrived on") changed the behavior
> of how link-local-multicast packets are processed. The change in
> the behavior broke some legacy use cases where these packets are
> expected to arrive on bonding master device also.
Unfortunately, this doesn't completely restore the previous
functionality as PACKET_ORIGDEV is broken for the copy: the original
interface is lost through the call to netif_rx(). A LLDP daemon
listening to the master interface won't get the original interface like
it was able to before 4.12.
I am a bit lost of what the original patch was trying to achieve. I am
using the following test program:
#v+
#!/usr/bin/env python3
import sys
import socket
import datetime
socket.SOL_PACKET = 263
socket.ETH_P_ALL = 3
socket.PACKET_ORIGDEV = 9
interface = sys.argv[1] if len(sys.argv) > 1 else 'lag1'
s = socket.socket(socket.AF_PACKET,
socket.SOCK_RAW,
socket.htons(socket.ETH_P_ALL))
s.bind((interface, 0))
s.setsockopt(socket.SOL_PACKET, socket.PACKET_ORIGDEV, 1)
while True:
data, addrinfo = s.recvfrom(1500)
if addrinfo[2] == socket.PACKET_OUTGOING:
continue
print(f"{datetime.datetime.now().isoformat()}: "
f"Received {len(data)} bytes from {addrinfo}")
#v-
If I run it with a kernel compiled with the commit before b89f04c61efe
(plus a few more cherry-pick to make it work like ea8ffc0818d8 and
72ccc471e13b), I get:
#v+
2018-11-30T22:20:40.193378: Received 221 bytes from ('eth1', 35020, 2, 1,
b'RT3\x00\x00\x02')
2018-11-30T22:20:40.194504: Received 221 bytes from ('eth0', 35020, 2, 1,
b'RT3\x00\x00\x01')
#v-
If I send non link-local packets, I get:
#v+
2018-11-30T22:25:57.300965: Received 98 bytes from ('eth0', 2048, 0, 1,
b'PT3\x00\x00\x02')
#v-
I am also able to correctly receive link-local packets directly on each
interface. So, it seems everything was working as expected before
b89f04c61efe.
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