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-rw-r--r--net/core/net_namespace.c133
1 files changed, 87 insertions, 46 deletions
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 572af0011997..2c2eb1b629b1 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -147,24 +147,17 @@ static void ops_free_list(const struct pernet_operations *ops,
}
}
-static void rtnl_net_notifyid(struct net *net, struct net *peer, int cmd,
- int id);
+/* should be called with nsid_lock held */
static int alloc_netid(struct net *net, struct net *peer, int reqid)
{
- int min = 0, max = 0, id;
-
- ASSERT_RTNL();
+ int min = 0, max = 0;
if (reqid >= 0) {
min = reqid;
max = reqid + 1;
}
- id = idr_alloc(&net->netns_ids, peer, min, max, GFP_KERNEL);
- if (id >= 0)
- rtnl_net_notifyid(net, peer, RTM_NEWNSID, id);
-
- return id;
+ 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
@@ -180,11 +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)
@@ -192,36 +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;
@@ -242,6 +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);
+ spin_lock_init(&net->nsid_lock);
list_for_each_entry(ops, &pernet_list, list) {
error = ops_init(ops, net);
@@ -362,14 +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;
- if (id >= 0) {
- rtnl_net_notifyid(tmp, net, RTM_DELNSID, 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();
@@ -497,6 +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;
@@ -517,14 +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;
@@ -538,14 +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 nsid)
+ 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)
@@ -554,14 +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;
- if (nsid >= 0) {
- id = nsid;
- } else {
- 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);
@@ -578,7 +618,7 @@ static int rtnl_net_getid(struct sk_buff *skb, struct nlmsghdr *nlh)
struct nlattr *tb[NETNSA_MAX + 1];
struct sk_buff *msg;
struct net *peer;
- int err;
+ int err, id;
err = nlmsg_parse(nlh, sizeof(struct rtgenmsg), tb, NETNSA_MAX,
rtnl_net_policy);
@@ -600,8 +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_NEWNSID, net, peer, -1);
+ RTM_NEWNSID, net, id);
if (err < 0)
goto err_out;
@@ -633,7 +674,7 @@ static int rtnl_net_dumpid_one(int id, void *peer, void *data)
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, peer, id);
+ RTM_NEWNSID, net_cb->net, id);
if (ret < 0)
return ret;
@@ -652,17 +693,17 @@ static int rtnl_net_dumpid(struct sk_buff *skb, struct netlink_callback *cb)
.idx = 0,
.s_idx = cb->args[0],
};
+ unsigned long flags;
- ASSERT_RTNL();
-
+ 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, struct net *peer, int cmd,
- int id)
+static void rtnl_net_notifyid(struct net *net, int cmd, int id)
{
struct sk_buff *msg;
int err = -ENOMEM;
@@ -671,7 +712,7 @@ static void rtnl_net_notifyid(struct net *net, struct net *peer, int cmd,
if (!msg)
goto out;
- err = rtnl_net_fill(msg, 0, 0, 0, cmd, net, peer, id);
+ err = rtnl_net_fill(msg, 0, 0, 0, cmd, net, id);
if (err < 0)
goto err_out;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-29 14:17:28 +0000