From patchwork Wed Nov 7 04:12:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: NeilBrown X-Patchwork-Id: 10671793 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 855F115E9 for ; Wed, 7 Nov 2018 04:14:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 74C8328741 for ; Wed, 7 Nov 2018 04:14:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6899628917; Wed, 7 Nov 2018 04:14:57 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8D5E328AFC for ; Wed, 7 Nov 2018 04:14:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389061AbeKGNnb (ORCPT ); Wed, 7 Nov 2018 08:43:31 -0500 Received: from mx2.suse.de ([195.135.220.15]:56714 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388530AbeKGNnb (ORCPT ); Wed, 7 Nov 2018 08:43:31 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 914F2B11C; Wed, 7 Nov 2018 04:14:47 +0000 (UTC) From: NeilBrown To: "J. Bruce Fields" , Chuck Lever , Jeff Layton , Trond Myklebust , Anna Schumaker Date: Wed, 07 Nov 2018 15:12:31 +1100 Subject: [PATCH 12/23] NFS/SUNRPC: don't lookup machine credential until rpcauth_bindcred(). Cc: Linux NFS Mailing List , linux-kernel@vger.kernel.org Message-ID: <154156395117.24086.12738019247425162006.stgit@noble> In-Reply-To: <154156285766.24086.14262073575778354276.stgit@noble> References: <154156285766.24086.14262073575778354276.stgit@noble> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Sender: linux-nfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When NFS creates a machine credential, it is a "generic" credential, not tied to any auth protocol, and is really just a container for the princpal name. This doesn't get linked to a genuine credential until rpcauth_bindcred() is called. The lookup always succeeds, so various places that test if the machine credential is NULL, are pointless. As a step towards getting rid of generic credentials, this patch gets rid of generic machine credentials. The nfs_client and rpc_client just hold a pointer to a constant principal name. When a machine credential is wanted, a special static 'struct rpc_cred' pointer is used. rpcauth_bindcred() recognizes this, finds the principal from the client, and binds the correct credential. Signed-off-by: NeilBrown --- fs/nfs/client.c | 11 ++--------- fs/nfs/nfs4_fs.h | 9 +-------- fs/nfs/nfs4state.c | 21 ++++----------------- fs/nfsd/nfs4callback.c | 12 ++++-------- include/linux/nfs_fs_sb.h | 3 +-- include/linux/sunrpc/auth.h | 3 ++- include/linux/sunrpc/clnt.h | 1 + net/sunrpc/auth.c | 42 +++++++++++++++++++++++++++++++++++++++--- net/sunrpc/auth_generic.c | 21 --------------------- net/sunrpc/clnt.c | 1 + 10 files changed, 55 insertions(+), 69 deletions(-) diff --git a/fs/nfs/client.c b/fs/nfs/client.c index cce151776709..fb1cf1a4bda2 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -151,7 +151,6 @@ EXPORT_SYMBOL_GPL(unregister_nfs_version); struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init) { struct nfs_client *clp; - struct rpc_cred *cred; int err = -ENOMEM; if ((clp = kzalloc(sizeof(*clp), GFP_KERNEL)) == NULL) @@ -182,9 +181,7 @@ struct nfs_client *nfs_alloc_client(const struct nfs_client_initdata *cl_init) clp->cl_proto = cl_init->proto; clp->cl_net = get_net(cl_init->net); - cred = rpc_lookup_machine_cred("*"); - if (!IS_ERR(cred)) - clp->cl_machine_cred = cred; + clp->cl_principal = "*"; nfs_fscache_get_client_cookie(clp); return clp; @@ -246,11 +243,6 @@ void nfs_free_client(struct nfs_client *clp) if (!IS_ERR(clp->cl_rpcclient)) rpc_shutdown_client(clp->cl_rpcclient); - if (clp->cl_machine_cred != NULL) - put_rpccred(clp->cl_machine_cred); - if (clp->cl_root_cred != NULL) - put_rpccred(clp->cl_root_cred); - put_net(clp->cl_net); put_nfs_version(clp->cl_nfs_mod); kfree(clp->cl_hostname); @@ -529,6 +521,7 @@ int nfs_create_rpc_client(struct nfs_client *clp, return PTR_ERR(clnt); } + clnt->cl_principal = clp->cl_principal; clp->cl_rpcclient = clnt; return 0; } diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index 0f393eb6b4e4..431fbac63a09 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -336,7 +336,6 @@ static inline bool _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode, struct rpc_clnt **clntp, struct rpc_message *msg) { - struct rpc_cred *newcred = NULL; rpc_authflavor_t flavor; if (sp4_mode == NFS_SP4_MACH_CRED_CLEANUP || @@ -351,13 +350,7 @@ _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode, return false; } if (test_bit(sp4_mode, &clp->cl_sp4_flags)) { - spin_lock(&clp->cl_lock); - if (clp->cl_machine_cred != NULL) - /* don't call get_rpccred on the machine cred - - * a reference will be held for life of clp */ - newcred = clp->cl_machine_cred; - spin_unlock(&clp->cl_lock); - msg->rpc_cred = newcred; + msg->rpc_cred = rpc_machine_cred(); flavor = clp->cl_rpcclient->cl_auth->au_flavor; WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I && diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index dde17424c4f4..f6f984d8a94b 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -166,28 +166,15 @@ int nfs40_discover_server_trunking(struct nfs_client *clp, struct rpc_cred *nfs4_get_machine_cred(struct nfs_client *clp) { - struct rpc_cred *cred = clp->cl_root_cred; - - if (!cred) - cred = clp->cl_machine_cred; - if (cred) - return get_rpccred(cred); - return cred; + return get_rpccred(rpc_machine_cred()); } static void nfs4_root_machine_cred(struct nfs_client *clp) { - struct rpc_cred *new; - new = rpc_lookup_machine_cred(NULL); - spin_lock(&clp->cl_lock); - if (clp->cl_root_cred == NULL) { - clp->cl_root_cred = new; - new = NULL; - } - spin_unlock(&clp->cl_lock); - if (new != NULL) - put_rpccred(new); + /* Force root creds instead of machine */ + clp->cl_principal = NULL; + clp->cl_rpcclient->cl_principal = NULL; } static struct rpc_cred * diff --git a/fs/nfsd/nfs4callback.c b/fs/nfsd/nfs4callback.c index c032e4c24a8d..1dcee1fd32d9 100644 --- a/fs/nfsd/nfs4callback.c +++ b/fs/nfsd/nfs4callback.c @@ -847,14 +847,10 @@ static int max_cb_time(struct net *net) static struct rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses) { if (clp->cl_minorversion == 0) { - char *principal = clp->cl_cred.cr_targ_princ ? - clp->cl_cred.cr_targ_princ : "nfs"; - struct rpc_cred *cred; - - cred = rpc_lookup_machine_cred(principal); - if (!IS_ERR(cred)) - get_rpccred(cred); - return cred; + client->cl_principal = clp->cl_cred.cr_targ_princ ? + clp->cl_cred.cr_targ_princ : "nfs"; + + return get_rpccred(rpc_machine_cred()); } else { struct rpc_auth *auth = client->cl_auth; struct auth_cred acred = {}; diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h index fea51b44fe50..6aa8cc83c3b6 100644 --- a/include/linux/nfs_fs_sb.h +++ b/include/linux/nfs_fs_sb.h @@ -58,8 +58,7 @@ struct nfs_client { struct nfs_subversion * cl_nfs_mod; /* pointer to nfs version module */ u32 cl_minorversion;/* NFSv4 minorversion */ - struct rpc_cred *cl_machine_cred; - struct rpc_cred *cl_root_cred; /* Use when machine_cred is ineffective */ + const char * cl_principal; /* used for machine cred */ #if IS_ENABLED(CONFIG_NFS_V4) struct list_head cl_ds_clients; /* auth flavor data servers */ diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h index 1c0468f39479..28b34c740c43 100644 --- a/include/linux/sunrpc/auth.h +++ b/include/linux/sunrpc/auth.h @@ -75,6 +75,8 @@ struct rpc_cred { #define RPCAUTH_CRED_HASHED 2 #define RPCAUTH_CRED_NEGATIVE 3 +struct rpc_cred *rpc_machine_cred(void); + /* rpc_auth au_flags */ #define RPCAUTH_AUTH_NO_CRKEY_TIMEOUT 0x0001 /* underlying cred has no key timeout */ @@ -170,7 +172,6 @@ void rpc_destroy_authunix(void); struct rpc_cred * rpc_lookup_cred(void); struct rpc_cred * rpc_lookup_cred_nonblock(void); struct rpc_cred * rpc_lookup_generic_cred(struct auth_cred *, int, gfp_t); -struct rpc_cred * rpc_lookup_machine_cred(const char *service_name); int rpcauth_register(const struct rpc_authops *); int rpcauth_unregister(const struct rpc_authops *); struct rpc_auth * rpcauth_create(const struct rpc_auth_create_args *, diff --git a/include/linux/sunrpc/clnt.h b/include/linux/sunrpc/clnt.h index 73d5c4a870fa..fc6dfbf77a9d 100644 --- a/include/linux/sunrpc/clnt.h +++ b/include/linux/sunrpc/clnt.h @@ -66,6 +66,7 @@ struct rpc_clnt { struct rpc_rtt cl_rtt_default; struct rpc_timeout cl_timeout_default; const struct rpc_program *cl_program; + const char * cl_principal; /* use for machine cred */ #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) struct dentry *cl_debugfs; /* debugfs directory */ #endif diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index 63e2d35c10d5..9e709dcc8c39 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -39,6 +39,20 @@ static const struct rpc_authops __rcu *auth_flavors[RPC_AUTH_MAXFLAVOR] = { static LIST_HEAD(cred_unused); static unsigned long number_cred_unused; +static struct rpc_cred machine_cred = { + .cr_count = REFCOUNT_INIT(1), +}; + +/* + * Return the machine_cred pointer to be used whenever + * the a generic machine credential is needed. + */ +struct rpc_cred *rpc_machine_cred(void) +{ + return &machine_cred; +} +EXPORT_SYMBOL_GPL(rpc_machine_cred); + #define MAX_HASHTABLE_BITS (14) static int param_set_hashtbl_sz(const char *val, const struct kernel_param *kp) { @@ -702,6 +716,22 @@ rpcauth_bind_root_cred(struct rpc_task *task, int lookupflags) return ret; } +static struct rpc_cred * +rpcauth_bind_machine_cred(struct rpc_task *task, int lookupflags) +{ + struct rpc_auth *auth = task->tk_client->cl_auth; + struct auth_cred acred = { + .principal = task->tk_client->cl_principal, + .cred = init_task.cred, + }; + + if (!acred.principal) + return NULL; + dprintk("RPC: %5u looking up %s machine cred\n", + task->tk_pid, task->tk_client->cl_auth->au_ops->au_name); + return auth->au_ops->lookup_cred(auth, &acred, lookupflags); +} + static struct rpc_cred * rpcauth_bind_new_cred(struct rpc_task *task, int lookupflags) { @@ -716,14 +746,20 @@ static int rpcauth_bindcred(struct rpc_task *task, struct rpc_cred *cred, int flags) { struct rpc_rqst *req = task->tk_rqstp; - struct rpc_cred *new; + struct rpc_cred *new = NULL; int lookupflags = 0; if (flags & RPC_TASK_ASYNC) lookupflags |= RPCAUTH_LOOKUP_NEW; - if (cred != NULL) + if (cred != NULL && cred != &machine_cred) new = cred->cr_ops->crbind(task, cred, lookupflags); - else if (flags & RPC_TASK_ROOTCREDS) + else if (cred == &machine_cred) + new = rpcauth_bind_machine_cred(task, lookupflags); + + /* If machine cred couldn't be bound, try a root cred */ + if (new) + ; + else if (cred == &machine_cred || (flags & RPC_TASK_ROOTCREDS)) new = rpcauth_bind_root_cred(task, lookupflags); else new = rpcauth_bind_new_cred(task, lookupflags); diff --git a/net/sunrpc/auth_generic.c b/net/sunrpc/auth_generic.c index 810d535c79b8..8cf5aa515c51 100644 --- a/net/sunrpc/auth_generic.c +++ b/net/sunrpc/auth_generic.c @@ -48,27 +48,6 @@ struct rpc_cred *rpc_lookup_cred_nonblock(void) } EXPORT_SYMBOL_GPL(rpc_lookup_cred_nonblock); -/* - * Public call interface for looking up machine creds. - * Note that if service_name is NULL, we actually look up - * "root" credential. - */ -struct rpc_cred *rpc_lookup_machine_cred(const char *service_name) -{ - struct auth_cred acred = { - .principal = service_name, - .cred = get_task_cred(&init_task), - }; - struct rpc_cred *ret; - - dprintk("RPC: looking up machine cred for service %s\n", - service_name); - ret = generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0); - put_cred(acred.cred); - return ret; -} -EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred); - static struct rpc_cred *generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred, int lookupflags) { diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c index ae3b8145da35..7c720b60f482 100644 --- a/net/sunrpc/clnt.c +++ b/net/sunrpc/clnt.c @@ -627,6 +627,7 @@ static struct rpc_clnt *__rpc_clone_client(struct rpc_create_args *args, new->cl_noretranstimeo = clnt->cl_noretranstimeo; new->cl_discrtry = clnt->cl_discrtry; new->cl_chatty = clnt->cl_chatty; + new->cl_principal = clnt->cl_principal; return new; out_err: