@@ -6,10 +6,14 @@
#define NETNS_GENL_NAME "netns"
#define NETNS_GENL_VERSION 0x1
+#define NETNS_GENL_MCAST_EVENT_NAME "events"
+
/* Commands */
enum {
NETNS_CMD_NOOP,
NETNS_CMD_GET,
+ NETNS_CMD_NEW,
+ NETNS_CMD_DEL,
__NETNS_CMD_MAX,
};
#define NETNS_CMD_MAX (__NETNS_CMD_MAX - 1)
@@ -40,6 +40,8 @@ EXPORT_SYMBOL(init_net);
static unsigned int max_gen_ptrs = INITIAL_NET_GEN_PTRS;
+static int netns_nl_event(struct net *net, int cmd);
+
static struct net_generic *net_alloc_generic(void)
{
struct net_generic *ng;
@@ -179,6 +181,7 @@ again:
if (error < 0)
goto out_undo;
}
+ netns_nl_event(net, NETNS_CMD_NEW);
out:
return error;
@@ -311,6 +314,7 @@ static void cleanup_net(struct work_struct *work)
synchronize_rcu();
list_for_each_entry(net, &net_exit_list, exit_list) {
+ netns_nl_event(net, NETNS_CMD_DEL);
/* Free the index */
ida_remove(&net_namespace_ids, net->nsindex);
}
@@ -413,6 +417,10 @@ struct net *get_net_ns_by_nsindex(int nsindex)
}
EXPORT_SYMBOL_GPL(get_net_ns_by_nsindex);
+static struct genl_multicast_group netns_nl_event_mcgrp = {
+ .name = NETNS_GENL_MCAST_EVENT_NAME,
+};
+
static struct genl_family netns_nl_family = {
.id = GENL_ID_GENERATE,
.name = NETNS_GENL_NAME,
@@ -562,10 +570,38 @@ static struct genl_ops netns_nl_ops[] = {
},
};
+static int netns_nl_event(struct net *net, int cmd)
+{
+ struct sk_buff *msg;
+ int err = -ENOBUFS;
+
+ /* Check that gennl infra is ready */
+ if (!netns_nl_event_mcgrp.id)
+ return -ENOENT;
+
+ msg = genlmsg_new(netns_nl_get_size(), GFP_ATOMIC);
+ if (!msg)
+ return -ENOMEM;
+
+ err = netns_nl_fill(msg, 0, 0, 0, cmd, net);
+ if (err < 0) {
+ nlmsg_free(msg);
+ return err;
+ }
+
+ return genlmsg_multicast(msg, 0, netns_nl_event_mcgrp.id, GFP_ATOMIC);
+}
+
int netns_genl_register(void)
{
- return genl_register_family_with_ops(&netns_nl_family, netns_nl_ops,
+ int err;
+
+ err = genl_register_family_with_ops(&netns_nl_family, netns_nl_ops,
ARRAY_SIZE(netns_nl_ops));
+ if (err < 0)
+ return err;
+
+ return genl_register_mc_group(&netns_nl_family, &netns_nl_event_mcgrp);
}
static int __init net_ns_init(void)
Goal of this patch is to send netlink messages when netns are crated/deleted. This is useful for daemon that wants to manage all netns with only one running instance. Note that until that netns_nl_event_mcgrp group is not registered, we cannot send event. Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> --- include/uapi/linux/netns.h | 4 ++++ net/core/net_namespace.c | 38 +++++++++++++++++++++++++++++++++++++- 2 files changed, 41 insertions(+), 1 deletion(-)