From: Roman Mashak <m...@mojatatu.com> Date: Tue, 10 Oct 2017 16:08:44 -0400
> When creating veth pair, at first rtnl_new_link() creates veth_dev, i.e. > one end of the veth pipe, but not registers it; then veth_newlink() gets > invoked, where peer dev is created _and_ registered, followed by veth_dev > registration, which may fail if peer information, that is VETH_INFO_PEER > attribute, has not been provided and the kernel will allocate unique veth > name. > > So, we should ask the kernel to allocate unique name for veth_dev only > when peer info is not available. > > Example: > > % ip link dev veth0 type veth > RTNETLINK answers: File exists > > After fix: > % ip link dev veth0 type veth > % ip link show dev veth0 > 5: veth0@veth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode > DEFAULT group default qlen 1000 > link/ether f6:ef:8b:96:f4:ec brd ff:ff:ff:ff:ff:ff > % > > Signed-off-by: Roman Mashak <m...@mojatatu.com> I'm not so sure about this. If we specify an explicit tb[IFLA_NAME], we shouldn't completely ignore that request from the user just because they didn't give any peer information. I see what happens in this case, the peer gets 'veth0' and then since the user asked for 'veth0' for the non-peer it conflicts. Well, too bad. The user must work to orchestrate things such that this doesn't happen. That means either providing the IFLA_NAME for both the peer and the non-peer, or specifying neither. I'm not applying this, sorry.
