[PATCH net-next v10 01/13] rtnetlink: Lookup device in target netns when creating link
From: Xiao Liang <hidden>
Date: 2025-02-19 12:51:04
Also in:
batman, bpf, bridge, linux-can, linux-kselftest, linux-rdma, linux-wireless, lkml
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
When creating link, lookup for existing device in target net namespace instead of current one. For example, two links created by: # ip link add dummy1 type dummy # ip link add netns ns1 dummy1 type dummy should have no conflict since they are in different namespaces. Signed-off-by: Xiao Liang <redacted> Reviewed-by: Kuniyuki Iwashima <redacted> --- net/core/rtnetlink.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index abe1a461ea67..0f3e2c6021de 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c@@ -3867,20 +3867,26 @@ static int __rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, { struct nlattr ** const tb = tbs->tb; struct net *net = sock_net(skb->sk); + struct net *device_net; struct net_device *dev; struct ifinfomsg *ifm; bool link_specified; + /* When creating, lookup for existing device in target net namespace */ + device_net = (nlh->nlmsg_flags & NLM_F_CREATE) && + (nlh->nlmsg_flags & NLM_F_EXCL) ? + tgt_net : net; + ifm = nlmsg_data(nlh); if (ifm->ifi_index > 0) { link_specified = true; - dev = __dev_get_by_index(net, ifm->ifi_index); + dev = __dev_get_by_index(device_net, ifm->ifi_index); } else if (ifm->ifi_index < 0) { NL_SET_ERR_MSG(extack, "ifindex can't be negative"); return -EINVAL; } else if (tb[IFLA_IFNAME] || tb[IFLA_ALT_IFNAME]) { link_specified = true; - dev = rtnl_dev_get(net, tb); + dev = rtnl_dev_get(device_net, tb); } else { link_specified = false; dev = NULL;
--
2.48.1