From 097e66c578459f79e3a2128c54e9df5194e1419a Mon Sep 17 00:00:00 2001 From: "Denis V. Lunev" Date: Mon, 19 Nov 2007 22:29:30 -0800 Subject: [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 Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller --- net/unix/af_unix.c | 118 +++++++++++++++++++++++++++++++++++++++++------------ 1 file changed, 92 insertions(+), 26 deletions(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 060bba4567d..ecad42b72ad 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; @@ -2006,12 +2017,18 @@ 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; @@ -2022,17 +2039,24 @@ 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) @@ -2094,7 +2118,27 @@ 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 = { @@ -2102,7 +2146,7 @@ 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 @@ -2113,6 +2157,30 @@ 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; @@ -2128,9 +2196,7 @@ 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; @@ -2140,8 +2206,8 @@ 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); -- cgit v1.2.3