On Wed, May 31, 2017 at 03:48:06PM +0200, Nicolas Dichtel wrote: > Le 31/05/2017 à 14:28, Flavio Leitner a écrit : > > On Wed, May 31, 2017 at 10:38:21AM +0200, Nicolas Dichtel wrote: > >> Le 30/05/2017 à 23:33, Flavio Leitner a écrit : > >>> Don't include netns id for notifications broadcasts when the > >>> socket and the skb are in the same netns because it will be > >>> an error which can't be distinguished from a peer netns failing > >>> to allocate an id. > >> I don't understand the problem. peernet2id() doesn't allocate ids, it only > >> do a > >> lookup. If you need an id for the current netns, you have to allocate one. > > > > The issue is that if you query an interface on the same netns, the > > error is returned, then we cannot tell if the iface is on the same > > netns or if there was an error while allocating the ID and the > > iface is on another netns. > If the returned id is NETNSA_NSID_NOT_ASSIGNED, then the netns is the same. > > Some lines before your patch, we call peernet_has_id() when the netns differ, > thus we ensure that the id is available.
Right, but that's internal to the kernel. > The principle was that netlink messages of other netns can be sent only if an > id > is assigned. OK, could you please update include/uapi/linux/net_namespace.h to reflect that? It says NETNSA_NSID_NOT_ASSIGNED are attributes for RTM_NEWNSID or RTM_GETNSID which makes sense, but NOT_ASSIGNED sounds little like SAME_NSID for other message types. -- Flavio
