[Devel] [PATCH 2.6.25 5/6] net: Make AF_UNIX per network namespace safe (v2)
Denis V. Lunev
den at openvz.org
Thu Nov 15 08:00:41 PST 2007
>From 337f0867c81ab93a1bc645e62896a798d0c864ac Mon Sep 17 00:00:00 2001
From: Denis V. Lunev <den at openvz.org>
Date: Thu, 15 Nov 2007 15:04:12 +0300
Subject: [PATCH] net: Make AF_UNIX per network namespace safe [v2]
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.
Changes from v1:
- fixed unix_seq_open
Signed-off-by: Denis V. Lunev <den at openvz.org>
Signed-off-by: Eric W. Biederman <ebiederm at xmission.com>
---
net/unix/af_unix.c | 118 ++++++++++++++++++++++++++++++++++++++++-----------
1 files changed, 92 insertions(+), 26 deletions(-)
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index e835da8..93d7e55 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);
@@ -631,9 +639,6 @@ 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;
@@ -677,6 +682,7 @@ 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;
@@ -703,7 +709,7 @@ 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... */
@@ -723,7 +729,8 @@ 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;
@@ -741,7 +748,7 @@ 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;
@@ -757,7 +764,7 @@ 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;
@@ -779,6 +786,7 @@ 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;
@@ -853,7 +861,7 @@ 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;
@@ -919,6 +927,7 @@ 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;
@@ -935,7 +944,7 @@ 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;
@@ -1015,6 +1024,7 @@ 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;
@@ -1054,7 +1064,7 @@ 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;
@@ -1330,6 +1340,7 @@ 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;
@@ -1393,7 +1404,7 @@ 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;
@@ -1999,12 +2010,18 @@ 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;
@@ -2015,17 +2032,24 @@ 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)
@@ -2087,7 +2111,27 @@ static const struct seq_operations unix_seq_ops = {
static int unix_seq_open(struct inode *inode, struct file *file)
{
- return seq_open_private(file, &unix_seq_ops, sizeof(int));
+ struct unix_iter_state *it;
+
+ it = __seq_open_private(file, &unix_seq_ops,
+ sizeof(struct unix_iter_state));
+ if (it == NULL)
+ return -ENOMEM;
+
+ it->net = get_proc_net(inode);
+ if (it->net == NULL) {
+ seq_release_private(inode, file);
+ return -ENXIO;
+ }
+ return 0;
+}
+
+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 = {
@@ -2095,7 +2139,7 @@ static const struct file_operations unix_seq_fops = {
.open = unix_seq_open,
.read = seq_read,
.llseek = seq_lseek,
- .release = seq_release_private,
+ .release = unix_seq_release,
};
#endif
@@ -2106,6 +2150,30 @@ 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;
@@ -2121,9 +2189,7 @@ 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;
@@ -2133,8 +2199,8 @@ 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.rc5
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