unix_bind(): take BSD and abstract address cases into new helpers
authorAl Viro <viro@zeniv.linux.org.uk>
Sat, 19 Jun 2021 03:50:29 +0000 (03:50 +0000)
committerDavid S. Miller <davem@davemloft.net>
Mon, 21 Jun 2021 19:28:49 +0000 (12:28 -0700)
unix_bind_bsd() and unix_bind_abstract() respectively.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/unix/af_unix.c

index 84ddfb25bc6419ca4766ee1cf228fbf1e2f0c591..d48ebfb182c76df42770efe65a3b204a008c8b4e 100644 (file)
@@ -1014,104 +1014,105 @@ static int unix_mknod(const char *sun_path, umode_t mode, struct path *res)
        return err;
 }
 
+static int unix_bind_bsd(struct sock *sk, struct unix_address *addr)
+{
+       struct unix_sock *u = unix_sk(sk);
+       struct path path = { };
+       umode_t mode = S_IFSOCK |
+              (SOCK_INODE(sk->sk_socket)->i_mode & ~current_umask());
+       unsigned int hash;
+       int err;
+
+       err = unix_mknod(addr->name->sun_path, mode, &path);
+       if (err)
+               return err;
+
+       err = mutex_lock_interruptible(&u->bindlock);
+       if (err) {
+               path_put(&path);
+               return err;
+       }
+
+       if (u->addr) {
+               mutex_unlock(&u->bindlock);
+               path_put(&path);
+               return -EINVAL;
+       }
+
+       addr->hash = UNIX_HASH_SIZE;
+       hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1);
+       spin_lock(&unix_table_lock);
+       u->path = path;
+       __unix_set_addr(sk, addr, hash);
+       spin_unlock(&unix_table_lock);
+       mutex_unlock(&u->bindlock);
+       return 0;
+}
+
+static int unix_bind_abstract(struct sock *sk, unsigned hash,
+                             struct unix_address *addr)
+{
+       struct unix_sock *u = unix_sk(sk);
+       int err;
+
+       err = mutex_lock_interruptible(&u->bindlock);
+       if (err)
+               return err;
+
+       if (u->addr) {
+               mutex_unlock(&u->bindlock);
+               return -EINVAL;
+       }
+
+       spin_lock(&unix_table_lock);
+       if (__unix_find_socket_byname(sock_net(sk), addr->name, addr->len,
+                                     sk->sk_type, hash)) {
+               spin_unlock(&unix_table_lock);
+               mutex_unlock(&u->bindlock);
+               return -EADDRINUSE;
+       }
+       __unix_set_addr(sk, addr, addr->hash);
+       spin_unlock(&unix_table_lock);
+       mutex_unlock(&u->bindlock);
+       return 0;
+}
+
 static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 {
        struct sock *sk = sock->sk;
-       struct net *net = sock_net(sk);
-       struct unix_sock *u = unix_sk(sk);
        struct sockaddr_un *sunaddr = (struct sockaddr_un *)uaddr;
        char *sun_path = sunaddr->sun_path;
        int err;
        unsigned int hash;
        struct unix_address *addr;
 
-       err = -EINVAL;
        if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
            sunaddr->sun_family != AF_UNIX)
-               goto out;
+               return -EINVAL;
 
-       if (addr_len == sizeof(short)) {
-               err = unix_autobind(sock);
-               goto out;
-       }
+       if (addr_len == sizeof(short))
+               return unix_autobind(sock);
 
        err = unix_mkname(sunaddr, addr_len, &hash);
        if (err < 0)
-               goto out;
+               return err;
        addr_len = err;
-       err = -ENOMEM;
        addr = kmalloc(sizeof(*addr)+addr_len, GFP_KERNEL);
        if (!addr)
-               goto out;
+               return -ENOMEM;
 
        memcpy(addr->name, sunaddr, addr_len);
        addr->len = addr_len;
        addr->hash = hash ^ sk->sk_type;
        refcount_set(&addr->refcnt, 1);
 
-       if (sun_path[0]) {
-               struct path path = { };
-               umode_t mode = S_IFSOCK |
-                      (SOCK_INODE(sock)->i_mode & ~current_umask());
-               err = unix_mknod(sun_path, mode, &path);
-               if (err) {
-                       if (err == -EEXIST)
-                               err = -EADDRINUSE;
-                       goto out_addr;
-               }
-
-               err = mutex_lock_interruptible(&u->bindlock);
-               if (err) {
-                       path_put(&path);
-                       goto out_addr;
-               }
-
-               err = -EINVAL;
-               if (u->addr) {
-                       mutex_unlock(&u->bindlock);
-                       path_put(&path);
-                       goto out_addr;
-               }
-
-               addr->hash = UNIX_HASH_SIZE;
-               hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1);
-               spin_lock(&unix_table_lock);
-               u->path = path;
-               __unix_set_addr(sk, addr, hash);
-               spin_unlock(&unix_table_lock);
-               mutex_unlock(&u->bindlock);
-               addr = NULL;
-               err = 0;
-       } else {
-               err = mutex_lock_interruptible(&u->bindlock);
-               if (err)
-                       goto out_addr;
-
-               err = -EINVAL;
-               if (u->addr) {
-                       mutex_unlock(&u->bindlock);
-                       goto out_addr;
-               }
-
-               spin_lock(&unix_table_lock);
-               err = -EADDRINUSE;
-               if (__unix_find_socket_byname(net, sunaddr, addr_len,
-                                             sk->sk_type, hash)) {
-                       spin_unlock(&unix_table_lock);
-                       mutex_unlock(&u->bindlock);
-                       goto out_addr;
-               }
-               __unix_set_addr(sk, addr, addr->hash);
-               spin_unlock(&unix_table_lock);
-               mutex_unlock(&u->bindlock);
-               addr = NULL;
-               err = 0;
-       }
-out_addr:
-       if (addr)
+       if (sun_path[0])
+               err = unix_bind_bsd(sk, addr);
+       else
+               err = unix_bind_abstract(sk, hash, addr);
+       if (err)
                unix_release_addr(addr);
-out:
-       return err;
+       return err == -EEXIST ? -EADDRINUSE : err;
 }
 
 static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)