From patchwork Mon Feb 22 19:12:18 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Al Viro X-Patchwork-Id: 386062 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 746F2C433E6 for ; Mon, 22 Feb 2021 19:20:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4648164E32 for ; Mon, 22 Feb 2021 19:20:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232956AbhBVTTw (ORCPT ); Mon, 22 Feb 2021 14:19:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35628 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230442AbhBVTNF (ORCPT ); Mon, 22 Feb 2021 14:13:05 -0500 Received: from zeniv-ca.linux.org.uk (zeniv-ca.linux.org.uk [IPv6:2607:5300:60:148a::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A87BFC061786; Mon, 22 Feb 2021 11:12:25 -0800 (PST) Received: from viro by zeniv-ca.linux.org.uk with local (Exim 4.94 #2 (Red Hat Linux)) id 1lEGd4-00HAzp-CX; Mon, 22 Feb 2021 19:12:22 +0000 From: Al Viro To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Christoph Hellwig , Jakub Kicinski , Denis Kirjanov , linux-fsdevel , Cong Wang Subject: [PATCH 4/8] unix_bind(): take BSD and abstract address cases into new helpers Date: Mon, 22 Feb 2021 19:12:18 +0000 Message-Id: <20210222191222.4093800-4-viro@zeniv.linux.org.uk> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210222191222.4093800-1-viro@zeniv.linux.org.uk> References: <20210222191222.4093800-1-viro@zeniv.linux.org.uk> MIME-Version: 1.0 Sender: Al Viro Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org unix_bind_bsd() and unix_bind_abstract() respectively. Signed-off-by: Al Viro --- net/unix/af_unix.c | 147 +++++++++++++++++++++++++++-------------------------- 1 file changed, 74 insertions(+), 73 deletions(-) diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 496b069c99fe..56443f05ed9d 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1012,104 +1012,105 @@ 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)