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-rw-r--r--net/core/net_namespace.c188
1 files changed, 150 insertions, 38 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 70d3450588b2..2c2eb1b629b1 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -16,7 +16,6 @@
#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>
@@ -148,18 +147,17 @@ static void ops_free_list(const struct pernet_operations *ops,
}
}
+/* should be called with nsid_lock held */
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);
+ return idr_alloc(&net->netns_ids, peer, min, max, GFP_ATOMIC);
}
/* This function is used by idr_for_each(). If net is equal to peer, the
@@ -175,11 +173,16 @@ static int net_eq_idr(int id, void *net, void *peer)
return 0;
}
-static int __peernet2id(struct net *net, struct net *peer, bool alloc)
+/* Should be called with nsid_lock held. If a new id is assigned, the bool alloc
+ * is set to true, thus the caller knows that the new id must be notified via
+ * rtnl.
+ */
+static int __peernet2id_alloc(struct net *net, struct net *peer, bool *alloc)
{
int id = idr_for_each(&net->netns_ids, net_eq_idr, peer);
+ bool alloc_it = *alloc;
- ASSERT_RTNL();
+ *alloc = false;
/* Magic value for id 0. */
if (id == NET_ID_ZERO)
@@ -187,36 +190,77 @@ static int __peernet2id(struct net *net, struct net *peer, bool alloc)
if (id > 0)
return id;
- if (alloc)
- return alloc_netid(net, peer, -1);
+ if (alloc_it) {
+ id = alloc_netid(net, peer, -1);
+ *alloc = true;
+ return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
+ }
+
+ return NETNSA_NSID_NOT_ASSIGNED;
+}
+
+/* should be called with nsid_lock held */
+static int __peernet2id(struct net *net, struct net *peer)
+{
+ bool no = false;
- return -ENOENT;
+ return __peernet2id_alloc(net, peer, &no);
}
+static void rtnl_net_notifyid(struct net *net, int cmd, int id);
/* This function returns the id of a peer netns. If no id is assigned, one will
* be allocated and returned.
*/
+int peernet2id_alloc(struct net *net, struct net *peer)
+{
+ unsigned long flags;
+ bool alloc;
+ int id;
+
+ spin_lock_irqsave(&net->nsid_lock, flags);
+ alloc = atomic_read(&peer->count) == 0 ? false : true;
+ id = __peernet2id_alloc(net, peer, &alloc);
+ spin_unlock_irqrestore(&net->nsid_lock, flags);
+ if (alloc && id >= 0)
+ rtnl_net_notifyid(net, RTM_NEWNSID, id);
+ return id;
+}
+EXPORT_SYMBOL(peernet2id_alloc);
+
+/* This function returns, if assigned, the id of a peer netns. */
int peernet2id(struct net *net, struct net *peer)
{
- bool alloc = atomic_read(&peer->count) == 0 ? false : true;
+ unsigned long flags;
int id;
- id = __peernet2id(net, peer, alloc);
- return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
+ spin_lock_irqsave(&net->nsid_lock, flags);
+ id = __peernet2id(net, peer);
+ spin_unlock_irqrestore(&net->nsid_lock, flags);
+ return id;
+}
+
+/* This function returns true is the peer netns has an id assigned into the
+ * current netns.
+ */
+bool peernet_has_id(struct net *net, struct net *peer)
+{
+ return peernet2id(net, peer) >= 0;
}
-EXPORT_SYMBOL(peernet2id);
struct net *get_net_ns_by_id(struct net *net, int id)
{
+ unsigned long flags;
struct net *peer;
if (id < 0)
return NULL;
rcu_read_lock();
+ spin_lock_irqsave(&net->nsid_lock, flags);
peer = idr_find(&net->netns_ids, id);
if (peer)
get_net(peer);
+ spin_unlock_irqrestore(&net->nsid_lock, flags);
rcu_read_unlock();
return peer;
@@ -237,10 +281,7 @@ static __net_init int setup_net(struct net *net, struct user_namespace *user_ns)
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);
-#endif
+ spin_lock_init(&net->nsid_lock);
list_for_each_entry(ops, &pernet_list, list) {
error = ops_init(ops, net);
@@ -296,13 +337,6 @@ out_free:
static void net_free(struct net *net)
{
-#ifdef NETNS_REFCNT_DEBUG
- if (unlikely(atomic_read(&net->use_count) != 0)) {
- pr_emerg("network namespace not free! Usage: %d\n",
- atomic_read(&net->use_count));
- return;
- }
-#endif
kfree(rcu_access_pointer(net->gen));
kmem_cache_free(net_cachep, net);
}
@@ -368,12 +402,19 @@ static void cleanup_net(struct work_struct *work)
list_del_rcu(&net->list);
list_add_tail(&net->exit_list, &net_exit_list);
for_each_net(tmp) {
- int id = __peernet2id(tmp, net, false);
+ int id;
+ spin_lock_irq(&tmp->nsid_lock);
+ id = __peernet2id(tmp, net);
if (id >= 0)
idr_remove(&tmp->netns_ids, id);
+ spin_unlock_irq(&tmp->nsid_lock);
+ if (id >= 0)
+ rtnl_net_notifyid(tmp, RTM_DELNSID, id);
}
+ spin_lock_irq(&net->nsid_lock);
idr_destroy(&net->netns_ids);
+ spin_unlock_irq(&net->nsid_lock);
}
rtnl_unlock();
@@ -501,6 +542,7 @@ 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];
+ unsigned long flags;
struct net *peer;
int nsid, err;
@@ -521,14 +563,19 @@ static int rtnl_net_newid(struct sk_buff *skb, struct nlmsghdr *nlh)
if (IS_ERR(peer))
return PTR_ERR(peer);
- if (__peernet2id(net, peer, false) >= 0) {
+ spin_lock_irqsave(&net->nsid_lock, flags);
+ if (__peernet2id(net, peer) >= 0) {
+ spin_unlock_irqrestore(&net->nsid_lock, flags);
err = -EEXIST;
goto out;
}
err = alloc_netid(net, peer, nsid);
- if (err > 0)
+ spin_unlock_irqrestore(&net->nsid_lock, flags);
+ if (err >= 0) {
+ rtnl_net_notifyid(net, RTM_NEWNSID, err);
err = 0;
+ }
out:
put_net(peer);
return err;
@@ -542,13 +589,10 @@ static int rtnl_net_get_size(void)
}
static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
- int cmd, struct net *net, struct net *peer)
+ int cmd, struct net *net, int nsid)
{
struct nlmsghdr *nlh;
struct rtgenmsg *rth;
- int id;
-
- ASSERT_RTNL();
nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rth), flags);
if (!nlh)
@@ -557,10 +601,7 @@ static int rtnl_net_fill(struct sk_buff *skb, u32 portid, u32 seq, int flags,
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))
+ if (nla_put_s32(skb, NETNSA_NSID, nsid))
goto nla_put_failure;
nlmsg_end(skb, nlh);
@@ -576,8 +617,8 @@ 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;
+ int err, id;
err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
rtnl_net_policy);
@@ -599,8 +640,9 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh)
goto out;
}
+ id = peernet2id(net, peer);
err = rtnl_net_fill(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq, 0,
- RTM_GETNSID, net, peer);
+ RTM_NEWNSID, net, id);
if (err < 0)
goto err_out;
@@ -614,6 +656,75 @@ out:
return err;
}
+struct rtnl_net_dump_cb {
+ struct net *net;
+ struct sk_buff *skb;
+ struct netlink_callback *cb;
+ int idx;
+ int s_idx;
+};
+
+static int rtnl_net_dumpid_one(int id, void *peer, void *data)
+{
+ struct rtnl_net_dump_cb *net_cb = (struct rtnl_net_dump_cb *)data;
+ int ret;
+
+ if (net_cb->idx < net_cb->s_idx)
+ goto cont;
+
+ ret = rtnl_net_fill(net_cb->skb, NETLINK_CB(net_cb->cb->skb).portid,
+ net_cb->cb->nlh->nlmsg_seq, NLM_F_MULTI,
+ RTM_NEWNSID, net_cb->net, id);
+ if (ret < 0)
+ return ret;
+
+cont:
+ net_cb->idx++;
+ return 0;
+}
+
+static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct net *net = sock_net(skb->sk);
+ struct rtnl_net_dump_cb net_cb = {
+ .net = net,
+ .skb = skb,
+ .cb = cb,
+ .idx = 0,
+ .s_idx = cb->args[0],
+ };
+ unsigned long flags;
+
+ spin_lock_irqsave(&net->nsid_lock, flags);
+ idr_for_each(&net->netns_ids, rtnl_net_dumpid_one, &net_cb);
+ spin_unlock_irqrestore(&net->nsid_lock, flags);
+
+ cb->args[0] = net_cb.idx;
+ return skb->len;
+}
+
+static void rtnl_net_notifyid(struct net *net, int cmd, int id)
+{
+ struct sk_buff *msg;
+ int err = -ENOMEM;
+
+ msg = nlmsg_new(rtnl_net_get_size(), GFP_KERNEL);
+ if (!msg)
+ goto out;
+
+ err = rtnl_net_fill(msg, 0, 0, 0, cmd, net, id);
+ if (err < 0)
+ goto err_out;
+
+ rtnl_notify(msg, net, 0, RTNLGRP_NSID, NULL, 0);
+ return;
+
+err_out:
+ nlmsg_free(msg);
+out:
+ rtnl_set_sk_err(net, RTNLGRP_NSID, err);
+}
+
static int __init net_ns_init(void)
{
struct net_generic *ng;
@@ -648,7 +759,8 @@ 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);
+ rtnl_register(PF_UNSPEC, RTM_GETNSID, rtnl_net_getid, rtnl_net_dumpid,
+ NULL);
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-05-11 22:24:05 +0000