Merge git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd

* git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/linux-2.6-nsfd:
  net: fix get_net_ns_by_fd for !CONFIG_NET_NS
  ns proc: Return -ENOENT for a nonexistent /proc/self/ns/ entry.
  ns: Declare sys_setns in syscalls.h
  net: Allow setting the network namespace by fd
  ns proc: Add support for the ipc namespace
  ns proc: Add support for the uts namespace
  ns proc: Add support for the network namespace.
  ns: Introduce the setns syscall
  ns: proc files for namespace naming policy.

2 files changed, 69 insertions, 1 deletions

diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 2e2dce6583e..6c6b86d0da1 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -8,6 +8,8 @@
 #include <linux/idr.h>
 #include <linux/rculist.h>
 #include <linux/nsproxy.h>
+#include <linux/proc_fs.h>
+#include <linux/file.h>
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 
@@ -302,6 +304,28 @@ void __put_net(struct net *net)
 }
 EXPORT_SYMBOL_GPL(__put_net);
 
+struct net *get_net_ns_by_fd(int fd)
+{
+        struct proc_inode *ei;
+        struct file *file;
+        struct net *net;
+
+        net = ERR_PTR(-EINVAL);
+        file = proc_ns_fget(fd);
+        if (!file)
+                goto out;
+
+        ei = PROC_I(file->f_dentry->d_inode);
+        if (ei->ns_ops != &netns_operations)
+                goto out;
+
+        net = get_net(ei->ns);
+out:
+        if (file)
+                fput(file);
+        return net;
+}
+
 #else
 struct net *copy_net_ns(unsigned long flags, struct net *old_net)
 {
@@ -309,6 +333,11 @@ struct net *copy_net_ns(unsigned long flags, struct net *old_net)
                 return ERR_PTR(-EINVAL);
         return old_net;
 }
+
+struct net *get_net_ns_by_fd(int fd)
+{
+        return ERR_PTR(-EINVAL);
+}
 #endif
 
 struct net *get_net_ns_by_pid(pid_t pid)
@@ -561,3 +590,39 @@ void unregister_pernet_device(struct pernet_operations *ops)
         mutex_unlock(&net_mutex);
 }
 EXPORT_SYMBOL_GPL(unregister_pernet_device);
+
+#ifdef CONFIG_NET_NS
+static void *netns_get(struct task_struct *task)
+{
+        struct net *net = NULL;
+        struct nsproxy *nsproxy;
+
+        rcu_read_lock();
+        nsproxy = task_nsproxy(task);
+        if (nsproxy)
+                net = get_net(nsproxy->net_ns);
+        rcu_read_unlock();
+
+        return net;
+}
+
+static void netns_put(void *ns)
+{
+        put_net(ns);
+}
+
+static int netns_install(struct nsproxy *nsproxy, void *ns)
+{
+        put_net(nsproxy->net_ns);
+        nsproxy->net_ns = get_net(ns);
+        return 0;
+}
+
+const struct proc_ns_operations netns_operations = {
+        .name           = "net",
+        .type           = CLONE_NEWNET,
+        .get            = netns_get,
+        .put            = netns_put,
+        .install        = netns_install,
+};
+#endif
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 2d56cb9b0b9..abd936d8a71 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1046,6 +1046,7 @@ const struct nla_policy ifla_policy[IFLA_MAX+1] = {
         [IFLA_LINKMODE]         = { .type = NLA_U8 },
         [IFLA_LINKINFO]         = { .type = NLA_NESTED },
         [IFLA_NET_NS_PID]       = { .type = NLA_U32 },
+        [IFLA_NET_NS_FD]        = { .type = NLA_U32 },
         [IFLA_IFALIAS]          = { .type = NLA_STRING, .len = IFALIASZ-1 },
         [IFLA_VFINFO_LIST]      = {. type = NLA_NESTED },
         [IFLA_VF_PORTS]         = { .type = NLA_NESTED },
@@ -1094,6 +1095,8 @@ struct net *rtnl_link_get_net(struct net *src_net, struct nlattr *tb[])
          */
         if (tb[IFLA_NET_NS_PID])
                 net = get_net_ns_by_pid(nla_get_u32(tb[IFLA_NET_NS_PID]));
+        else if (tb[IFLA_NET_NS_FD])
+                net = get_net_ns_by_fd(nla_get_u32(tb[IFLA_NET_NS_FD]));
         else
                 net = get_net(src_net);
         return net;
@@ -1224,7 +1227,7 @@ static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
         int send_addr_notify = 0;
         int err;
 
-        if (tb[IFLA_NET_NS_PID]) {
+        if (tb[IFLA_NET_NS_PID] || tb[IFLA_NET_NS_FD]) {
                 struct net *net = rtnl_link_get_net(dev_net(dev), tb);
                 if (IS_ERR(net)) {
                         err = PTR_ERR(net);