From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Date: Mon, 26 Nov 2018 14:42:05 +0000 (+0100)
Subject: netns: enable to specify a nsid for a get request
X-Git-Tag: v5.15~7332^2~201^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3a4f68bf660414801781fd06506a9c75c2d936e5;p=platform%2Fkernel%2Flinux-starfive.git

netns: enable to specify a nsid for a get request

Combined with NETNSA_TARGET_NSID, it enables to "translate" a nsid from one
netns to a nsid of another netns.
This is useful when using NETLINK_F_LISTEN_ALL_NSID because it helps the
user to interpret a nsid received from an other netns.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 885c541..dd25fb2 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -797,6 +797,11 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh,
 	} else if (tb[NETNSA_FD]) {
 		peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
 		nla = tb[NETNSA_FD];
+	} else if (tb[NETNSA_NSID]) {
+		peer = get_net_ns_by_id(net, nla_get_u32(tb[NETNSA_NSID]));
+		if (!peer)
+			peer = ERR_PTR(-ENOENT);
+		nla = tb[NETNSA_NSID];
 	} else {
 		NL_SET_ERR_MSG(extack, "Peer netns reference is missing");
 		return -EINVAL;