From 59324cf35aba5336b611074028777838a963d03b Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel 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 Acked-by: Thomas Graf Signed-off-by: David S. Miller --- include/linux/netlink.h | 2 ++ include/net/net_namespace.h | 2 ++ include/uapi/linux/netlink.h | 1 + 3 files changed, 5 insertions(+) (limited to 'include') diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 6835c1279df7..9120edb650a0 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -28,6 +28,8 @@ struct netlink_skb_parms { __u32 dst_group; __u32 flags; struct sock *sk; + bool nsid_is_set; + int nsid; }; #define NETLINK_CB(skb) (*(struct netlink_skb_parms*)&((skb)->cb)) diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 6d1e2eae32fb..3f850acc844e 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -272,6 +272,8 @@ static inline struct net *read_pnet(const possible_net_t *pnet) #endif int peernet2id_alloc(struct net *net, struct net *peer); +int peernet2id(struct net *net, struct net *peer); +bool peernet_has_id(struct net *net, struct net *peer); struct net *get_net_ns_by_id(struct net *net, int id); struct pernet_operations { diff --git a/include/uapi/linux/netlink.h b/include/uapi/linux/netlink.h index 1a85940f8ab7..3e34b7d702f8 100644 --- a/include/uapi/linux/netlink.h +++ b/include/uapi/linux/netlink.h @@ -108,6 +108,7 @@ struct nlmsgerr { #define NETLINK_NO_ENOBUFS 5 #define NETLINK_RX_RING 6 #define NETLINK_TX_RING 7 +#define NETLINK_LISTEN_ALL_NSID 8 struct nl_pktinfo { __u32 group; -- cgit v1.2.3