[NET]: netlink support for moving devices between network namespaces.
The simplest thing to implement is moving network devices between
namespaces. However with the same attribute IFLA_NET_NS_PID we can
easily implement creating devices in the destination network
namespace as well. However that is a little bit trickier so this
patch sticks to what is simple and easy.
A pid is used to identify a process that happens to be a member
of the network namespace we want to move the network device to.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 44f91bb..1b9c32d 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -35,6 +35,7 @@
#include <linux/security.h>
#include <linux/mutex.h>
#include <linux/if_addr.h>
+#include <linux/nsproxy.h>
#include <asm/uaccess.h>
#include <asm/system.h>
@@ -727,6 +728,7 @@
[IFLA_WEIGHT] = { .type = NLA_U32 },
[IFLA_OPERSTATE] = { .type = NLA_U8 },
[IFLA_LINKMODE] = { .type = NLA_U8 },
+ [IFLA_NET_NS_PID] = { .type = NLA_U32 },
};
static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
@@ -734,12 +736,45 @@
[IFLA_INFO_DATA] = { .type = NLA_NESTED },
};
+static struct net *get_net_ns_by_pid(pid_t pid)
+{
+ struct task_struct *tsk;
+ struct net *net;
+
+ /* Lookup the network namespace */
+ net = ERR_PTR(-ESRCH);
+ rcu_read_lock();
+ tsk = find_task_by_pid(pid);
+ if (tsk) {
+ task_lock(tsk);
+ if (tsk->nsproxy)
+ net = get_net(tsk->nsproxy->net_ns);
+ task_unlock(tsk);
+ }
+ rcu_read_unlock();
+ return net;
+}
+
static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
struct nlattr **tb, char *ifname, int modified)
{
int send_addr_notify = 0;
int err;
+ if (tb[IFLA_NET_NS_PID]) {
+ struct net *net;
+ net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
+ if (IS_ERR(net)) {
+ err = PTR_ERR(net);
+ goto errout;
+ }
+ err = dev_change_net_namespace(dev, net, ifname);
+ put_net(net);
+ if (err)
+ goto errout;
+ modified = 1;
+ }
+
if (tb[IFLA_MAP]) {
struct rtnl_link_ifmap *u_map;
struct ifmap k_map;