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 <[email protected]>
---
drivers/net/veth.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/veth.c b/drivers/net/veth.c
index f5438d0..00dce15 100644
--- a/drivers/net/veth.c
+++ b/drivers/net/veth.c
@@ -432,7 +432,7 @@ static int veth_newlink(struct net *src_net, struct
net_device *dev,
if (tb[IFLA_ADDRESS] == NULL)
eth_hw_addr_random(dev);
- if (tb[IFLA_IFNAME])
+ if (ifmp && tb[IFLA_IFNAME])
nla_strlcpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
else
snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
--
1.9.1
