[Devel] [PATCH 5/5] net: Make AF_UNIX per network namespace safe.
Eric W. Biederman
ebiederm at xmission.com
Fri Sep 28 18:08:05 PDT 2007
Because of the global nature of garbage collection, and because of the
cost of per namespace hash tables unix_socket_table has been kept
global. With a filter added on lookups so we don't see sockets from
the wrong namespace.
Currently I don't fold the namesapce into the hash so multiple
namespaces using the same socket name will be guaranteed a hash
collision.
Signed-off-by: Eric W. Biederman <ebiederm at xmission.com>
---
net/unix/af_unix.c | 113 +++++++++++++++++++++++++++++++++++++++------------
1 files changed, 86 insertions(+), 27 deletions(-)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 10e7312..2792ef2 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -270,7 +270,8 @@ static inline void unix_insert_socket(struct hlist_head *list, struct sock *sk)
spin_unlock(&unix_table_lock);
}
-static struct sock *__unix_find_socket_byname(struct sockaddr_un *sunname,
+static struct sock *__unix_find_socket_byname(struct net *net,
+ struct sockaddr_un *sunname,
int len, int type, unsigned hash)
{
struct sock *s;
@@ -279,6 +280,9 @@ static struct sock *__unix_find_socket_byname(struct sockaddr_un *sunname,
sk_for_each(s, node, &unix_socket_table[hash ^ type]) {
struct unix_sock *u = unix_sk(s);
+ if (s->sk_net != net)
+ continue;
+
if (u->addr->len == len &&
!memcmp(u->addr->name, sunname, len))
goto found;
@@ -288,21 +292,22 @@ found:
return s;
}
-static inline struct sock *unix_find_socket_byname(struct sockaddr_un *sunname,
+static inline struct sock *unix_find_socket_byname(struct net *net,
+ struct sockaddr_un *sunname,
int len, int type,
unsigned hash)
{
struct sock *s;
spin_lock(&unix_table_lock);
- s = __unix_find_socket_byname(sunname, len, type, hash);
+ s = __unix_find_socket_byname(net, sunname, len, type, hash);
if (s)
sock_hold(s);
spin_unlock(&unix_table_lock);
return s;
}
-static struct sock *unix_find_socket_byinode(struct inode *i)
+static struct sock *unix_find_socket_byinode(struct net *net, struct inode *i)
{
struct sock *s;
struct hlist_node *node;
@@ -312,6 +317,9 @@ static struct sock *unix_find_socket_byinode(struct inode *i)
&unix_socket_table[i->i_ino & (UNIX_HASH_SIZE - 1)]) {
struct dentry *dentry = unix_sk(s)->dentry;
+ if (s->sk_net != net)
+ continue;
+
if(dentry && dentry->d_inode == i)
{
sock_hold(s);
@@ -630,9 +638,6 @@ out:
static int unix_create(struct net *net, struct socket *sock, int protocol)
{
- if (net != &init_net)
- return -EAFNOSUPPORT;
-
if (protocol && protocol != PF_UNIX)
return -EPROTONOSUPPORT;
@@ -676,6 +681,7 @@ static int unix_release(struct socket *sock)
static int unix_autobind(struct socket *sock)
{
struct sock *sk = sock->sk;
+ struct net *net = sk->sk_net;
struct unix_sock *u = unix_sk(sk);
static u32 ordernum = 1;
struct unix_address * addr;
@@ -702,7 +708,7 @@ retry:
spin_lock(&unix_table_lock);
ordernum = (ordernum+1)&0xFFFFF;
- if (__unix_find_socket_byname(addr->name, addr->len, sock->type,
+ if (__unix_find_socket_byname(net, addr->name, addr->len, sock->type,
addr->hash)) {
spin_unlock(&unix_table_lock);
/* Sanity yield. It is unusual case, but yet... */
@@ -722,7 +728,8 @@ out: mutex_unlock(&u->readlock);
return err;
}
-static struct sock *unix_find_other(struct sockaddr_un *sunname, int len,
+static struct sock *unix_find_other(struct net *net,
+ struct sockaddr_un *sunname, int len,
int type, unsigned hash, int *error)
{
struct sock *u;
@@ -740,7 +747,7 @@ static struct sock *unix_find_other(struct sockaddr_un *sunname, int len,
err = -ECONNREFUSED;
if (!S_ISSOCK(nd.dentry->d_inode->i_mode))
goto put_fail;
- u=unix_find_socket_byinode(nd.dentry->d_inode);
+ u=unix_find_socket_byinode(net, nd.dentry->d_inode);
if (!u)
goto put_fail;
@@ -756,7 +763,7 @@ static struct sock *unix_find_other(struct sockaddr_un *sunname, int len,
}
} else {
err = -ECONNREFUSED;
- u=unix_find_socket_byname(sunname, len, type, hash);
+ u=unix_find_socket_byname(net, sunname, len, type, hash);
if (u) {
struct dentry *dentry;
dentry = unix_sk(u)->dentry;
@@ -778,6 +785,7 @@ fail:
static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
struct sock *sk = sock->sk;
+ struct net *net = sk->sk_net;
struct unix_sock *u = unix_sk(sk);
struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
struct dentry * dentry = NULL;
@@ -852,7 +860,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
if (!sunaddr->sun_path[0]) {
err = -EADDRINUSE;
- if (__unix_find_socket_byname(sunaddr, addr_len,
+ if (__unix_find_socket_byname(net, sunaddr, addr_len,
sk->sk_type, hash)) {
unix_release_addr(addr);
goto out_unlock;
@@ -918,6 +926,7 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
int alen, int flags)
{
struct sock *sk = sock->sk;
+ struct net *net = sk->sk_net;
struct sockaddr_un *sunaddr=(struct sockaddr_un*)addr;
struct sock *other;
unsigned hash;
@@ -934,7 +943,7 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr,
goto out;
restart:
- other=unix_find_other(sunaddr, alen, sock->type, hash, &err);
+ other=unix_find_other(net, sunaddr, alen, sock->type, hash, &err);
if (!other)
goto out;
@@ -1014,6 +1023,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
{
struct sockaddr_un *sunaddr=(struct sockaddr_un *)uaddr;
struct sock *sk = sock->sk;
+ struct net *net = sk->sk_net;
struct unix_sock *u = unix_sk(sk), *newu, *otheru;
struct sock *newsk = NULL;
struct sock *other = NULL;
@@ -1053,7 +1063,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
restart:
/* Find listening sock. */
- other = unix_find_other(sunaddr, addr_len, sk->sk_type, hash, &err);
+ other = unix_find_other(net, sunaddr, addr_len, sk->sk_type, hash, &err);
if (!other)
goto out;
@@ -1329,6 +1339,7 @@ static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
{
struct sock_iocb *siocb = kiocb_to_siocb(kiocb);
struct sock *sk = sock->sk;
+ struct net *net = sk->sk_net;
struct unix_sock *u = unix_sk(sk);
struct sockaddr_un *sunaddr=msg->msg_name;
struct sock *other = NULL;
@@ -1392,7 +1403,7 @@ restart:
if (sunaddr == NULL)
goto out_free;
- other = unix_find_other(sunaddr, namelen, sk->sk_type,
+ other = unix_find_other(net, sunaddr, namelen, sk->sk_type,
hash, &err);
if (other==NULL)
goto out_free;
@@ -1998,12 +2009,18 @@ static unsigned int unix_poll(struct file * file, struct socket *sock, poll_tabl
#ifdef CONFIG_PROC_FS
-static struct sock *unix_seq_idx(int *iter, loff_t pos)
+struct unix_iter_state {
+ struct net *net;
+ int i;
+};
+static struct sock *unix_seq_idx(struct unix_iter_state *iter, loff_t pos)
{
loff_t off = 0;
struct sock *s;
- for (s = first_unix_socket(iter); s; s = next_unix_socket(iter, s)) {
+ for (s = first_unix_socket(&iter->i); s; s = next_unix_socket(&iter->i, s)) {
+ if (s->sk_net != iter->net)
+ continue;
if (off == pos)
return s;
++off;
@@ -2014,17 +2031,24 @@ static struct sock *unix_seq_idx(int *iter, loff_t pos)
static void *unix_seq_start(struct seq_file *seq, loff_t *pos)
{
+ struct unix_iter_state *iter = seq->private;
spin_lock(&unix_table_lock);
- return *pos ? unix_seq_idx(seq->private, *pos - 1) : ((void *) 1);
+ return *pos ? unix_seq_idx(iter, *pos - 1) : ((void *) 1);
}
static void *unix_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
+ struct unix_iter_state *iter = seq->private;
+ struct sock *sk = v;
++*pos;
if (v == (void *)1)
- return first_unix_socket(seq->private);
- return next_unix_socket(seq->private, v);
+ sk = first_unix_socket(&iter->i);
+ else
+ sk = next_unix_socket(&iter->i, sk);
+ while (sk && (sk->sk_net != iter->net))
+ sk = next_unix_socket(&iter->i, sk);
+ return sk;
}
static void unix_seq_stop(struct seq_file *seq, void *v)
@@ -2088,7 +2112,7 @@ static int unix_seq_open(struct inode *inode, struct file *file)
{
struct seq_file *seq;
int rc = -ENOMEM;
- int *iter = kmalloc(sizeof(int), GFP_KERNEL);
+ struct unix_iter_state *iter = kmalloc(sizeof(*iter), GFP_KERNEL);
if (!iter)
goto out;
@@ -2099,7 +2123,12 @@ static int unix_seq_open(struct inode *inode, struct file *file)
seq = file->private_data;
seq->private = iter;
- *iter = 0;
+ iter->i = 0;
+ iter->net = get_proc_net(inode);
+ if (!iter->net) {
+ seq_release_private(inode, file);
+ rc = -ENXIO;
+ }
out:
return rc;
out_kfree:
@@ -2107,12 +2136,20 @@ out_kfree:
goto out;
}
+static int unix_seq_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq = file->private_data;
+ struct unix_iter_state *iter = seq->private;
+ put_net(iter->net);
+ return seq_release_private(inode, file);
+}
+
static const struct file_operations unix_seq_fops = {
.owner = THIS_MODULE,
.open = unix_seq_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release_private,
+ .release = unix_seq_release,
};
#endif
@@ -2123,6 +2160,30 @@ static struct net_proto_family unix_family_ops = {
.owner = THIS_MODULE,
};
+
+static int unix_net_init(struct net *net)
+{
+ int error = -ENOMEM;
+
+#ifdef CONFIG_PROC_FS
+ if (!proc_net_fops_create(net, "unix", 0, &unix_seq_fops))
+ goto out;
+#endif
+ error = 0;
+out:
+ return 0;
+}
+
+static void unix_net_exit(struct net *net)
+{
+ proc_net_remove(net, "unix");
+}
+
+static struct pernet_operations unix_net_ops = {
+ .init = unix_net_init,
+ .exit = unix_net_exit,
+};
+
static int __init af_unix_init(void)
{
int rc = -1;
@@ -2138,9 +2199,7 @@ static int __init af_unix_init(void)
}
sock_register(&unix_family_ops);
-#ifdef CONFIG_PROC_FS
- proc_net_fops_create(&init_net, "unix", 0, &unix_seq_fops);
-#endif
+ register_pernet_subsys(&unix_net_ops);
unix_sysctl_register();
out:
return rc;
@@ -2150,8 +2209,8 @@ static void __exit af_unix_exit(void)
{
sock_unregister(PF_UNIX);
unix_sysctl_unregister();
- proc_net_remove(&init_net, "unix");
proto_unregister(&unix_proto);
+ unregister_pernet_subsys(&unix_net_ops);
}
module_init(af_unix_init);
--
1.5.3.rc6.17.g1911
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