diff --git a/MAINTAINERS b/MAINTAINERS
index 9de900572633bdccd6a7afa39943d36e391b1a86..9b91d9f0257e370d61a32095fdcb8914a5882873 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6578,6 +6578,7 @@ F: include/linux/netdevice.h
F: include/uapi/linux/in.h
F: include/uapi/linux/net.h
F: include/uapi/linux/netdevice.h
+F: include/uapi/linux/net_namespace.h
F: tools/net/
F: tools/testing/selftests/net/
F: lib/random32.c
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 2e8756b8c77543391b1c3381fa442c2a2a1c582e..36faf4990c4b6f2604fd2b00178c941d75f540a8 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -60,6 +60,7 @@ struct net {
struct list_head exit_list; /* Use only net_mutex */
struct user_namespace *user_ns; /* Owning user namespace */
+ struct idr netns_ids;
struct ns_common ns;
@@ -290,6 +291,9 @@ static inline struct net *read_pnet(struct net * const *pnet)
#define __net_initconst __initconst
#endif
+int peernet2id(struct net *net, struct net *peer);
+struct net *get_net_ns_by_id(struct net *net, int id);
+
struct pernet_operations {
struct list_head list;
int (*init)(struct net *net);
diff --git a/include/uapi/linux/Kbuild b/include/uapi/linux/Kbuild
index 00b100023c477bf80de661c386ceb27461f4bbd6..14b7b6e44c77ce279960d852936e9fbf37b231da 100644
--- a/include/uapi/linux/Kbuild
+++ b/include/uapi/linux/Kbuild
@@ -283,6 +283,7 @@ header-y += net.h
header-y += netlink_diag.h
header-y += netlink.h
header-y += netrom.h
+header-y += net_namespace.h
header-y += net_tstamp.h
header-y += nfc.h
header-y += nfs2.h
diff --git a/include/uapi/linux/net_namespace.h b/include/uapi/linux/net_namespace.h
new file mode 100644
index 0000000000000000000000000000000000000000..778cd2c3ebf42eb8f3ce4621326b043b53817b7c
--- /dev/null
+++ b/include/uapi/linux/net_namespace.h
@@ -0,0 +1,23 @@
+/* Copyright (c) 2015 6WIND S.A.
+ * Author: Nicolas Dichtel <nicolas.dichtel@6wind.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+#ifndef _UAPI_LINUX_NET_NAMESPACE_H_
+#define _UAPI_LINUX_NET_NAMESPACE_H_
+
+/* Attributes of RTM_NEWNSID/RTM_GETNSID messages */
+enum {
+ NETNSA_NONE,
+#define NETNSA_NSID_NOT_ASSIGNED -1
+ NETNSA_NSID,
+ NETNSA_PID,
+ NETNSA_FD,
+ __NETNSA_MAX,
+};
+
+#define NETNSA_MAX (__NETNSA_MAX - 1)
+
+#endif /* _UAPI_LINUX_NET_NAMESPACE_H_ */
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index a1d18593f41ea1d0db0272e6dc305a22949607bc..5cc5d66bf519f65cb4b29e041c3b06fdbe01c889 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -132,6 +132,11 @@ enum {
RTM_GETMDB = 86,
#define RTM_GETMDB RTM_GETMDB
+ RTM_NEWNSID = 88,
+#define RTM_NEWNSID RTM_NEWNSID
+ RTM_GETNSID = 90,
+#define RTM_GETNSID RTM_GETNSID
+
__RTM_MAX,
#define RTM_MAX (((__RTM_MAX + 3) & ~3) - 1)
};
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index ce780c722e48ca2bf35534895ef0b7dc0a9541d5..9d1a4cac83b604cf657f1492628dbc4966db8eca 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -15,6 +15,10 @@
#include <linux/file.h>
#include <linux/export.h>
#include <linux/user_namespace.h>
+#include <linux/net_namespace.h>
+#include <linux/rtnetlink.h>
+#include <net/sock.h>
+#include <net/netlink.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
@@ -144,6 +148,77 @@ static void ops_free_list(const struct pernet_operations *ops,
}
}
+static int alloc_netid(struct net *net, struct net *peer, int reqid)
+{
+ int min = 0, max = 0;
+
+ ASSERT_RTNL();
+
+ if (reqid >= 0) {
+ min = reqid;
+ max = reqid + 1;
+ }
+
+ return idr_alloc(&net->netns_ids, peer, min, max, GFP_KERNEL);
+}
+
+/* This function is used by idr_for_each(). If net is equal to peer, the
+ * function returns the id so that idr_for_each() stops. Because we cannot
+ * returns the id 0 (idr_for_each() will not stop), we return the magic value
+ * NET_ID_ZERO (-1) for it.
+ */
+#define NET_ID_ZERO -1
+static int net_eq_idr(int id, void *net, void *peer)
+{
+ if (net_eq(net, peer))
+ return id ? : NET_ID_ZERO;
+ return 0;
+}
+
+static int __peernet2id(struct net *net, struct net *peer, bool alloc)
+{
+ int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
+
+ ASSERT_RTNL();
+
+ /* Magic value for id 0. */
+ if (id == NET_ID_ZERO)
+ return 0;
+ if (id > 0)
+ return id;
+
+ if (alloc)
+ return alloc_netid(net, peer, -1);
+
+ return -ENOENT;
+}
+
+/* This function returns the id of a peer netns. If no id is assigned, one will
+ * be allocated and returned.
+ */
+int peernet2id(struct net *net, struct net *peer)
+{
+ int id = __peernet2id(net, peer, true);
+
+ return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
+}
+
+struct net *get_net_ns_by_id(struct net *net, int id)
+{
+ struct net *peer;
+
+ if (id < 0)
+ return NULL;
+
+ rcu_read_lock();
+ peer = idr_find(&net->netns_ids, id);
+ if (peer)
+ get_net(peer);
+ rcu_read_unlock();
+
+ return peer;
+}
+
/*
* setup_net runs the initializers for the network namespace object.
*/
@@ -158,6 +233,7 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
atomic_set(&net->passive, 1);
net->dev_base_seq = 1;
net->user_ns = user_ns;
+ idr_init(&net->netns_ids);
#ifdef NETNS_REFCNT_DEBUG
atomic_set(&net->use_count, 0);
@@ -288,6 +364,14 @@ static void cleanup_net(struct work_struct *work)
list_for_each_entry(net, &net_kill_list, cleanup_list) {
list_del_rcu(&net->list);
list_add_tail(&net->exit_list, &net_exit_list);
+ for_each_net(tmp) {
+ int id = __peernet2id(tmp, net, false);
+
+ if (id >= 0)
+ idr_remove(&tmp->netns_ids, id);
+ }
+ idr_destroy(&net->netns_ids);
+
}
rtnl_unlock();
@@ -402,6 +486,130 @@ static struct pernet_operations __net_initdata net_ns_ops = {
.exit = net_ns_net_exit,
};
+static struct nla_policy rtnl_net_policy[NETNSA_MAX + 1] = {
+ [NETNSA_NONE] = { .type = NLA_UNSPEC },
+ [NETNSA_NSID] = { .type = NLA_S32 },
+ [NETNSA_PID] = { .type = NLA_U32 },
+ [NETNSA_FD] = { .type = NLA_U32 },
+};
+
+static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nlattr *tb[NETNSA_MAX + 1];
+ struct net *peer;
+ int nsid, err;
+
+ err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
+ rtnl_net_policy);
+ if (err < 0)
+ return err;
+ if (!tb[NETNSA_NSID])
+ return -EINVAL;
+ nsid = nla_get_s32(tb[NETNSA_NSID]);
+
+ if (tb[NETNSA_PID])
+ peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
+ else if (tb[NETNSA_FD])
+ peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
+ else
+ return -EINVAL;
+ if (IS_ERR(peer))
+ return PTR_ERR(peer);
+
+ if (__peernet2id(net, peer, false) >= 0) {
+ err = -EEXIST;
+ goto out;
+ }
+
+ err = alloc_netid(net, peer, nsid);
+ if (err > 0)
+ err = 0;
+out:
+ put_net(peer);
+ return err;
+}
+
+static int rtnl_net_get_size(void)
+{
+ return NLMSG_ALIGN(sizeof(struct rtgenmsg))
+ + nla_total_size(sizeof(s32)) /* NETNSA_NSID */
+ ;
+}
+
+static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
+ int cmd, struct net *net, struct net *peer)
+{
+ struct nlmsghdr *nlh;
+ struct rtgenmsg *rth;
+ int id;
+
+ ASSERT_RTNL();
+
+ nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ rth = nlmsg_data(nlh);
+ rth->rtgen_family = AF_UNSPEC;
+
+ id = __peernet2id(net, peer, false);
+ if (id < 0)
+ id = NETNSA_NSID_NOT_ASSIGNED;
+ if (nla_put_s32(skb, NETNSA_NSID, id))
+ goto nla_put_failure;
+
+ nlmsg_end(skb, nlh);
+ return 0;
+
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nlattr *tb[NETNSA_MAX + 1];
+ struct sk_buff *msg;
+ int err = -ENOBUFS;
+ struct net *peer;
+
+ err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
+ rtnl_net_policy);
+ if (err < 0)
+ return err;
+ if (tb[NETNSA_PID])
+ peer = get_net_ns_by_pid(nla_get_u32(tb[NETNSA_PID]));
+ else if (tb[NETNSA_FD])
+ peer = get_net_ns_by_fd(nla_get_u32(tb[NETNSA_FD]));
+ else
+ return -EINVAL;
+
+ if (IS_ERR(peer))
+ return PTR_ERR(peer);
+
+ msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
+ if (!msg) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
+ RTM_GETNSID, net, peer);
+ if (err < 0)
+ goto err_out;
+
+ err = rtnl_unicast(msg, net, NETLINK_CB(skb).portid);
+ goto out;
+
+err_out:
+ nlmsg_free(msg);
+out:
+ put_net(peer);
+ return err;
+}
+
static int __init net_ns_init(void)
{
struct net_generic *ng;
@@ -435,6 +643,9 @@ static int __init net_ns_init(void)
register_pernet_subsys(&net_ns_ops);
+ rtnl_register(PF_UNSPEC, RTM_NEWNSID, rtnl_net_newid, NULL, NULL);
+ rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, NULL, NULL);
+
return 0;
}