Hi all,
I just managed to track this down to systemd-udev.
While running the following command:
ip link add link eth0 name macvtap0 type macvtap mode bridge
I straced systemd-udev, and found the following nugget:
[pid 637] sendto(15, {{len=48, type=0x6c /* RTM_??? */,
flags=NLM_F_REQUEST|NLM_F_ACK|NLM_F_EXCL|NLM_F_CREATE|NLM_F_APPEND,
seq=3, pid=0}, {family=AF_UNSPEC,
"\x00\x00\x00\x07\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x10\x00\x34\x80\x0b\x00\x35\x00\x80\x40\x56\x07\xab\xaa\x00\x00"}},
48, 0, {sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, 16) = 48
where the undecoded RTM_??? is RTM_NEWLINKPROP, and the message
containing:
struct nlattr {
nla_len = 16,
nla_type = NLA_F_NESTED | IFLA_PROP_LIST,
}
struct ntattr {
nla_len = 11,
nla_type = IFLA_ALT_IFNAME,
}
altname = "\x80\x40\x56\x07\xab\xaa\x00\"
padding = "\0x00"
it looks like systemd-udev tries to set an altname (why?) based on some
uninitialized structure, and the kernel happily honors the request.
Based on the above, I'd say that iproute2 is innocent, and that someone
should investigate systemd.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
