[NET]: Support multiple network namespaces with netlink
Each netlink socket will live in exactly one network namespace,
this includes the controlling kernel sockets.
This patch updates all of the existing netlink protocols
to only support the initial network namespace. Request
by clients in other namespaces will get -ECONREFUSED.
As they would if the kernel did not have the support for
that netlink protocol compiled in.
As each netlink protocol is updated to be multiple network
namespace safe it can register multiple kernel sockets
to acquire a presence in the rest of the network namespaces.
The implementation in af_netlink is a simple filter implementation
at hash table insertion and hash table look up time.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 406a493..3029f86 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -211,7 +211,7 @@
wake_up(&nl_table_wait);
}
-static __inline__ struct sock *netlink_lookup(int protocol, u32 pid)
+static __inline__ struct sock *netlink_lookup(struct net *net, int protocol, u32 pid)
{
struct nl_pid_hash *hash = &nl_table[protocol].hash;
struct hlist_head *head;
@@ -221,7 +221,7 @@
read_lock(&nl_table_lock);
head = nl_pid_hashfn(hash, pid);
sk_for_each(sk, node, head) {
- if (nlk_sk(sk)->pid == pid) {
+ if ((sk->sk_net == net) && (nlk_sk(sk)->pid == pid)) {
sock_hold(sk);
goto found;
}
@@ -328,7 +328,7 @@
* makes sure updates are visible before bind or setsockopt return. */
}
-static int netlink_insert(struct sock *sk, u32 pid)
+static int netlink_insert(struct sock *sk, struct net *net, u32 pid)
{
struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
struct hlist_head *head;
@@ -341,7 +341,7 @@
head = nl_pid_hashfn(hash, pid);
len = 0;
sk_for_each(osk, node, head) {
- if (nlk_sk(osk)->pid == pid)
+ if ((osk->sk_net == net) && (nlk_sk(osk)->pid == pid))
break;
len++;
}
@@ -419,9 +419,6 @@
struct netlink_sock *nlk;
int err = 0;
- if (net != &init_net)
- return -EAFNOSUPPORT;
-
sock->state = SS_UNCONNECTED;
if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
@@ -481,6 +478,7 @@
if (nlk->pid && !nlk->subscriptions) {
struct netlink_notify n = {
+ .net = sk->sk_net,
.protocol = sk->sk_protocol,
.pid = nlk->pid,
};
@@ -509,6 +507,7 @@
static int netlink_autobind(struct socket *sock)
{
struct sock *sk = sock->sk;
+ struct net *net = sk->sk_net;
struct nl_pid_hash *hash = &nl_table[sk->sk_protocol].hash;
struct hlist_head *head;
struct sock *osk;
@@ -522,6 +521,8 @@
netlink_table_grab();
head = nl_pid_hashfn(hash, pid);
sk_for_each(osk, node, head) {
+ if ((osk->sk_net != net))
+ continue;
if (nlk_sk(osk)->pid == pid) {
/* Bind collision, search negative pid values. */
pid = rover--;
@@ -533,7 +534,7 @@
}
netlink_table_ungrab();
- err = netlink_insert(sk, pid);
+ err = netlink_insert(sk, net, pid);
if (err == -EADDRINUSE)
goto retry;
@@ -598,6 +599,7 @@
static int netlink_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
{
struct sock *sk = sock->sk;
+ struct net *net = sk->sk_net;
struct netlink_sock *nlk = nlk_sk(sk);
struct sockaddr_nl *nladdr = (struct sockaddr_nl *)addr;
int err;
@@ -619,7 +621,7 @@
return -EINVAL;
} else {
err = nladdr->nl_pid ?
- netlink_insert(sk, nladdr->nl_pid) :
+ netlink_insert(sk, net, nladdr->nl_pid) :
netlink_autobind(sock);
if (err)
return err;
@@ -703,10 +705,12 @@
static struct sock *netlink_getsockbypid(struct sock *ssk, u32 pid)
{
int protocol = ssk->sk_protocol;
+ struct net *net;
struct sock *sock;
struct netlink_sock *nlk;
- sock = netlink_lookup(protocol, pid);
+ net = ssk->sk_net;
+ sock = netlink_lookup(net, protocol, pid);
if (!sock)
return ERR_PTR(-ECONNREFUSED);
@@ -887,6 +891,7 @@
struct netlink_broadcast_data {
struct sock *exclude_sk;
+ struct net *net;
u32 pid;
u32 group;
int failure;
@@ -909,6 +914,9 @@
!test_bit(p->group - 1, nlk->groups))
goto out;
+ if ((sk->sk_net != p->net))
+ goto out;
+
if (p->failure) {
netlink_overrun(sk);
goto out;
@@ -947,6 +955,7 @@
int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
u32 group, gfp_t allocation)
{
+ struct net *net = ssk->sk_net;
struct netlink_broadcast_data info;
struct hlist_node *node;
struct sock *sk;
@@ -954,6 +963,7 @@
skb = netlink_trim(skb, allocation);
info.exclude_sk = ssk;
+ info.net = net;
info.pid = pid;
info.group = group;
info.failure = 0;
@@ -1002,6 +1012,9 @@
if (sk == p->exclude_sk)
goto out;
+ if (sk->sk_net != p->exclude_sk->sk_net)
+ goto out;
+
if (nlk->pid == p->pid || p->group - 1 >= nlk->ngroups ||
!test_bit(p->group - 1, nlk->groups))
goto out;
@@ -1304,7 +1317,7 @@
*/
struct sock *
-netlink_kernel_create(int unit, unsigned int groups,
+netlink_kernel_create(struct net *net, int unit, unsigned int groups,
void (*input)(struct sock *sk, int len),
struct mutex *cb_mutex, struct module *module)
{
@@ -1321,7 +1334,7 @@
if (sock_create_lite(PF_NETLINK, SOCK_DGRAM, unit, &sock))
return NULL;
- if (__netlink_create(&init_net, sock, cb_mutex, unit) < 0)
+ if (__netlink_create(net, sock, cb_mutex, unit) < 0)
goto out_sock_release;
if (groups < 32)
@@ -1336,18 +1349,20 @@
if (input)
nlk_sk(sk)->data_ready = input;
- if (netlink_insert(sk, 0))
+ if (netlink_insert(sk, net, 0))
goto out_sock_release;
nlk = nlk_sk(sk);
nlk->flags |= NETLINK_KERNEL_SOCKET;
netlink_table_grab();
- nl_table[unit].groups = groups;
- nl_table[unit].listeners = listeners;
- nl_table[unit].cb_mutex = cb_mutex;
- nl_table[unit].module = module;
- nl_table[unit].registered = 1;
+ if (!nl_table[unit].registered) {
+ nl_table[unit].groups = groups;
+ nl_table[unit].listeners = listeners;
+ nl_table[unit].cb_mutex = cb_mutex;
+ nl_table[unit].module = module;
+ nl_table[unit].registered = 1;
+ }
netlink_table_ungrab();
return sk;
@@ -1513,7 +1528,7 @@
atomic_inc(&skb->users);
cb->skb = skb;
- sk = netlink_lookup(ssk->sk_protocol, NETLINK_CB(skb).pid);
+ sk = netlink_lookup(ssk->sk_net, ssk->sk_protocol, NETLINK_CB(skb).pid);
if (sk == NULL) {
netlink_destroy_callback(cb);
return -ECONNREFUSED;
@@ -1555,7 +1570,8 @@
if (!skb) {
struct sock *sk;
- sk = netlink_lookup(in_skb->sk->sk_protocol,
+ sk = netlink_lookup(in_skb->sk->sk_net,
+ in_skb->sk->sk_protocol,
NETLINK_CB(in_skb).pid);
if (sk) {
sk->sk_err = ENOBUFS;
@@ -1706,6 +1722,7 @@
#ifdef CONFIG_PROC_FS
struct nl_seq_iter {
+ struct net *net;
int link;
int hash_idx;
};
@@ -1723,6 +1740,8 @@
for (j = 0; j <= hash->mask; j++) {
sk_for_each(s, node, &hash->table[j]) {
+ if (iter->net != s->sk_net)
+ continue;
if (off == pos) {
iter->link = i;
iter->hash_idx = j;
@@ -1752,11 +1771,14 @@
if (v == SEQ_START_TOKEN)
return netlink_seq_socket_idx(seq, 0);
- s = sk_next(v);
+ iter = seq->private;
+ s = v;
+ do {
+ s = sk_next(s);
+ } while (s && (iter->net != s->sk_net));
if (s)
return s;
- iter = seq->private;
i = iter->link;
j = iter->hash_idx + 1;
@@ -1765,6 +1787,8 @@
for (; j <= hash->mask; j++) {
s = sk_head(&hash->table[j]);
+ while (s && (iter->net != s->sk_net))
+ s = sk_next(s);
if (s) {
iter->link = i;
iter->hash_idx = j;
@@ -1835,15 +1859,24 @@
seq = file->private_data;
seq->private = iter;
+ iter->net = get_net(PROC_NET(inode));
return 0;
}
+static int netlink_seq_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq = file->private_data;
+ struct nl_seq_iter *iter = seq->private;
+ put_net(iter->net);
+ return seq_release_private(inode, file);
+}
+
static const struct file_operations netlink_seq_fops = {
.owner = THIS_MODULE,
.open = netlink_seq_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release_private,
+ .release = netlink_seq_release,
};
#endif
@@ -1885,6 +1918,27 @@
.owner = THIS_MODULE, /* for consistency 8) */
};
+static int netlink_net_init(struct net *net)
+{
+#ifdef CONFIG_PROC_FS
+ if (!proc_net_fops_create(net, "netlink", 0, &netlink_seq_fops))
+ return -ENOMEM;
+#endif
+ return 0;
+}
+
+static void netlink_net_exit(struct net *net)
+{
+#ifdef CONFIG_PROC_FS
+ proc_net_remove(net, "netlink");
+#endif
+}
+
+static struct pernet_operations netlink_net_ops = {
+ .init = netlink_net_init,
+ .exit = netlink_net_exit,
+};
+
static int __init netlink_proto_init(void)
{
struct sk_buff *dummy_skb;
@@ -1930,9 +1984,7 @@
}
sock_register(&netlink_family_ops);
-#ifdef CONFIG_PROC_FS
- proc_net_fops_create(&init_net, "netlink", 0, &netlink_seq_fops);
-#endif
+ register_pernet_subsys(&netlink_net_ops);
/* The netlink device handler may be needed early. */
rtnetlink_init();
out: