From 59324cf35aba5336b611074028777838a963d03b Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel <nicolas.dichtel@6wind.com> Date: Thu, 7 May 2015 11:02:53 +0200 Subject: netlink: allow to listen "all" netns More accurately, listen all netns that have a nsid assigned into the netns where the netlink socket is opened. For this purpose, a netlink socket option is added: NETLINK_LISTEN_ALL_NSID. When this option is set on a netlink socket, this socket will receive netlink notifications from all netns that have a nsid assigned into the netns where the socket has been opened. The nsid is sent to userland via an anscillary data. With this patch, a daemon needs only one socket to listen many netns. This is useful when the number of netns is high. Because 0 is a valid value for a nsid, the field nsid_is_set indicates if the field nsid is valid or not. skb->cb is initialized to 0 on skb allocation, thus we are sure that we will never send a nsid 0 by error to the userland. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net> --- net/core/net_namespace.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'net/core') diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c index ae5008b..a665bf4 100644 --- a/net/core/net_namespace.c +++ b/net/core/net_namespace.c @@ -229,7 +229,7 @@ int peernet2id_alloc(struct net *net, struct net *peer) EXPORT_SYMBOL(peernet2id_alloc); /* This function returns, if assigned, the id of a peer netns. */ -static int peernet2id(struct net *net, struct net *peer) +int peernet2id(struct net *net, struct net *peer) { unsigned long flags; int id; @@ -240,6 +240,14 @@ static int peernet2id(struct net *net, struct net *peer) return id; } +/* This function returns true is the peer netns has an id assigned into the + * current netns. + */ +bool peernet_has_id(struct net *net, struct net *peer) +{ + return peernet2id(net, peer) >= 0; +} + struct net *get_net_ns_by_id(struct net *net, int id) { unsigned long flags; -- cgit v1.1