diff options
Diffstat (limited to 'drivers/staging/lustre/lustre/ptlrpc/gss/gss_keyring.c')
| -rw-r--r-- | drivers/staging/lustre/lustre/ptlrpc/gss/gss_keyring.c | 1424 |
1 files changed, 1424 insertions, 0 deletions
diff --git a/drivers/staging/lustre/lustre/ptlrpc/gss/gss_keyring.c b/drivers/staging/lustre/lustre/ptlrpc/gss/gss_keyring.c new file mode 100644 index 000000000000..bb571ae51054 --- /dev/null +++ b/drivers/staging/lustre/lustre/ptlrpc/gss/gss_keyring.c @@ -0,0 +1,1424 @@ +/* + * GPL HEADER START + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 only, + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License version 2 for more details (a copy is included + * in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU General Public License + * version 2 along with this program; If not, see + * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf + * + * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + * GPL HEADER END + */ +/* + * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved. + * Use is subject to license terms. + * + * Copyright (c) 2012, Intel Corporation. + */ +/* + * This file is part of Lustre, http://www.lustre.org/ + * Lustre is a trademark of Sun Microsystems, Inc. + * + * lustre/ptlrpc/gss/gss_keyring.c + * + * Author: Eric Mei <ericm@clusterfs.com> + */ + +#define DEBUG_SUBSYSTEM S_SEC +#include <linux/init.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/dcache.h> +#include <linux/fs.h> +#include <linux/crypto.h> +#include <linux/key.h> +#include <linux/keyctl.h> +#include <linux/key-type.h> +#include <linux/mutex.h> +#include <asm/atomic.h> + +#include <obd.h> +#include <obd_class.h> +#include <obd_support.h> +#include <lustre/lustre_idl.h> +#include <lustre_sec.h> +#include <lustre_net.h> +#include <lustre_import.h> + +#include "gss_err.h" +#include "gss_internal.h" +#include "gss_api.h" + +static struct ptlrpc_sec_policy gss_policy_keyring; +static struct ptlrpc_ctx_ops gss_keyring_ctxops; +static struct key_type gss_key_type; + +static int sec_install_rctx_kr(struct ptlrpc_sec *sec, + struct ptlrpc_svc_ctx *svc_ctx); + +/* + * the timeout is only for the case that upcall child process die abnormally. + * in any other cases it should finally update kernel key. + * + * FIXME we'd better to incorporate the client & server side upcall timeouts + * into the framework of Adaptive Timeouts, but we need to figure out how to + * make sure that kernel knows the upcall processes is in-progress or died + * unexpectedly. + */ +#define KEYRING_UPCALL_TIMEOUT (obd_timeout + obd_timeout) + +/**************************************** + * internal helpers * + ****************************************/ + +#define DUMP_PROCESS_KEYRINGS(tsk) \ +{ \ + CWARN("DUMP PK: %s[%u,%u/%u](<-%s[%u,%u/%u]): " \ + "a %d, t %d, p %d, s %d, u %d, us %d, df %d\n", \ + tsk->comm, tsk->pid, tsk->uid, tsk->fsuid, \ + tsk->parent->comm, tsk->parent->pid, \ + tsk->parent->uid, tsk->parent->fsuid, \ + tsk->request_key_auth ? \ + tsk->request_key_auth->serial : 0, \ + key_cred(tsk)->thread_keyring ? \ + key_cred(tsk)->thread_keyring->serial : 0, \ + key_tgcred(tsk)->process_keyring ? \ + key_tgcred(tsk)->process_keyring->serial : 0, \ + key_tgcred(tsk)->session_keyring ? \ + key_tgcred(tsk)->session_keyring->serial : 0, \ + key_cred(tsk)->user->uid_keyring ? \ + key_cred(tsk)->user->uid_keyring->serial : 0, \ + key_cred(tsk)->user->session_keyring ? \ + key_cred(tsk)->user->session_keyring->serial : 0, \ + key_cred(tsk)->jit_keyring \ + ); \ +} + +#define DUMP_KEY(key) \ +{ \ + CWARN("DUMP KEY: %p(%d) ref %d u%u/g%u desc %s\n", \ + key, key->serial, atomic_read(&key->usage), \ + key->uid, key->gid, \ + key->description ? key->description : "n/a" \ + ); \ +} + +#define key_cred(tsk) ((tsk)->cred) +#define key_tgcred(tsk) ((tsk)->cred->tgcred) + +static inline void keyring_upcall_lock(struct gss_sec_keyring *gsec_kr) +{ +#ifdef HAVE_KEYRING_UPCALL_SERIALIZED + mutex_lock(&gsec_kr->gsk_uc_lock); +#endif +} + +static inline void keyring_upcall_unlock(struct gss_sec_keyring *gsec_kr) +{ +#ifdef HAVE_KEYRING_UPCALL_SERIALIZED + mutex_unlock(&gsec_kr->gsk_uc_lock); +#endif +} + +static inline void key_revoke_locked(struct key *key) +{ + set_bit(KEY_FLAG_REVOKED, &key->flags); +} + +static void ctx_upcall_timeout_kr(unsigned long data) +{ + struct ptlrpc_cli_ctx *ctx = (struct ptlrpc_cli_ctx *) data; + struct key *key = ctx2gctx_keyring(ctx)->gck_key; + + CWARN("ctx %p, key %p\n", ctx, key); + + LASSERT(key); + + cli_ctx_expire(ctx); + key_revoke_locked(key); +} + +static +void ctx_start_timer_kr(struct ptlrpc_cli_ctx *ctx, long timeout) +{ + struct gss_cli_ctx_keyring *gctx_kr = ctx2gctx_keyring(ctx); + struct timer_list *timer = gctx_kr->gck_timer; + + LASSERT(timer); + + CDEBUG(D_SEC, "ctx %p: start timer %lds\n", ctx, timeout); + timeout = timeout * HZ + cfs_time_current(); + + init_timer(timer); + timer->expires = timeout; + timer->data = (unsigned long ) ctx; + timer->function = ctx_upcall_timeout_kr; + + add_timer(timer); +} + +/* + * caller should make sure no race with other threads + */ +static +void ctx_clear_timer_kr(struct ptlrpc_cli_ctx *ctx) +{ + struct gss_cli_ctx_keyring *gctx_kr = ctx2gctx_keyring(ctx); + struct timer_list *timer = gctx_kr->gck_timer; + + if (timer == NULL) + return; + + CDEBUG(D_SEC, "ctx %p, key %p\n", ctx, gctx_kr->gck_key); + + gctx_kr->gck_timer = NULL; + + del_singleshot_timer_sync(timer); + + OBD_FREE_PTR(timer); +} + +static +struct ptlrpc_cli_ctx *ctx_create_kr(struct ptlrpc_sec *sec, + struct vfs_cred *vcred) +{ + struct ptlrpc_cli_ctx *ctx; + struct gss_cli_ctx_keyring *gctx_kr; + + OBD_ALLOC_PTR(gctx_kr); + if (gctx_kr == NULL) + return NULL; + + OBD_ALLOC_PTR(gctx_kr->gck_timer); + if (gctx_kr->gck_timer == NULL) { + OBD_FREE_PTR(gctx_kr); + return NULL; + } + init_timer(gctx_kr->gck_timer); + + ctx = &gctx_kr->gck_base.gc_base; + + if (gss_cli_ctx_init_common(sec, ctx, &gss_keyring_ctxops, vcred)) { + OBD_FREE_PTR(gctx_kr->gck_timer); + OBD_FREE_PTR(gctx_kr); + return NULL; + } + + ctx->cc_expire = cfs_time_current_sec() + KEYRING_UPCALL_TIMEOUT; + clear_bit(PTLRPC_CTX_NEW_BIT, &ctx->cc_flags); + atomic_inc(&ctx->cc_refcount); /* for the caller */ + + return ctx; +} + +static void ctx_destroy_kr(struct ptlrpc_cli_ctx *ctx) +{ + struct ptlrpc_sec *sec = ctx->cc_sec; + struct gss_cli_ctx_keyring *gctx_kr = ctx2gctx_keyring(ctx); + + CDEBUG(D_SEC, "destroying ctx %p\n", ctx); + + /* at this time the association with key has been broken. */ + LASSERT(sec); + LASSERT(atomic_read(&sec->ps_refcount) > 0); + LASSERT(atomic_read(&sec->ps_nctx) > 0); + LASSERT(test_bit(PTLRPC_CTX_CACHED_BIT, &ctx->cc_flags) == 0); + LASSERT(gctx_kr->gck_key == NULL); + + ctx_clear_timer_kr(ctx); + LASSERT(gctx_kr->gck_timer == NULL); + + if (gss_cli_ctx_fini_common(sec, ctx)) + return; + + OBD_FREE_PTR(gctx_kr); + + atomic_dec(&sec->ps_nctx); + sptlrpc_sec_put(sec); +} + +static void ctx_release_kr(struct ptlrpc_cli_ctx *ctx, int sync) +{ + if (sync) { + ctx_destroy_kr(ctx); + } else { + atomic_inc(&ctx->cc_refcount); + sptlrpc_gc_add_ctx(ctx); + } +} + +static void ctx_put_kr(struct ptlrpc_cli_ctx *ctx, int sync) +{ + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + + if (atomic_dec_and_test(&ctx->cc_refcount)) + ctx_release_kr(ctx, sync); +} + +/* + * key <-> ctx association and rules: + * - ctx might not bind with any key + * - key/ctx binding is protected by key semaphore (if the key present) + * - key and ctx each take a reference of the other + * - ctx enlist/unlist is protected by ctx spinlock + * - never enlist a ctx after it's been unlisted + * - whoever do enlist should also do bind, lock key before enlist: + * - lock key -> lock ctx -> enlist -> unlock ctx -> bind -> unlock key + * - whoever do unlist should also do unbind: + * - lock key -> lock ctx -> unlist -> unlock ctx -> unbind -> unlock key + * - lock ctx -> unlist -> unlock ctx -> lock key -> unbind -> unlock key + */ + +static inline void spin_lock_if(spinlock_t *lock, int condition) +{ + if (condition) + spin_lock(lock); +} + +static inline void spin_unlock_if(spinlock_t *lock, int condition) +{ + if (condition) + spin_unlock(lock); +} + +static void ctx_enlist_kr(struct ptlrpc_cli_ctx *ctx, int is_root, int locked) +{ + struct ptlrpc_sec *sec = ctx->cc_sec; + struct gss_sec_keyring *gsec_kr = sec2gsec_keyring(sec); + + LASSERT(!test_bit(PTLRPC_CTX_CACHED_BIT, &ctx->cc_flags)); + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + + spin_lock_if(&sec->ps_lock, !locked); + + atomic_inc(&ctx->cc_refcount); + set_bit(PTLRPC_CTX_CACHED_BIT, &ctx->cc_flags); + hlist_add_head(&ctx->cc_cache, &gsec_kr->gsk_clist); + if (is_root) + gsec_kr->gsk_root_ctx = ctx; + + spin_unlock_if(&sec->ps_lock, !locked); +} + +/* + * Note after this get called, caller should not access ctx again because + * it might have been freed, unless caller hold at least one refcount of + * the ctx. + * + * return non-zero if we indeed unlist this ctx. + */ +static int ctx_unlist_kr(struct ptlrpc_cli_ctx *ctx, int locked) +{ + struct ptlrpc_sec *sec = ctx->cc_sec; + struct gss_sec_keyring *gsec_kr = sec2gsec_keyring(sec); + + /* if hashed bit has gone, leave the job to somebody who is doing it */ + if (test_and_clear_bit(PTLRPC_CTX_CACHED_BIT, &ctx->cc_flags) == 0) + return 0; + + /* drop ref inside spin lock to prevent race with other operations */ + spin_lock_if(&sec->ps_lock, !locked); + + if (gsec_kr->gsk_root_ctx == ctx) + gsec_kr->gsk_root_ctx = NULL; + hlist_del_init(&ctx->cc_cache); + atomic_dec(&ctx->cc_refcount); + + spin_unlock_if(&sec->ps_lock, !locked); + + return 1; +} + +/* + * bind a key with a ctx together. + * caller must hold write lock of the key, as well as ref on key & ctx. + */ +static void bind_key_ctx(struct key *key, struct ptlrpc_cli_ctx *ctx) +{ + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + LASSERT(atomic_read(&key->usage) > 0); + LASSERT(ctx2gctx_keyring(ctx)->gck_key == NULL); + LASSERT(key->payload.data == NULL); + + /* at this time context may or may not in list. */ + key_get(key); + atomic_inc(&ctx->cc_refcount); + ctx2gctx_keyring(ctx)->gck_key = key; + key->payload.data = ctx; +} + +/* + * unbind a key and a ctx. + * caller must hold write lock, as well as a ref of the key. + */ +static void unbind_key_ctx(struct key *key, struct ptlrpc_cli_ctx *ctx) +{ + LASSERT(key->payload.data == ctx); + LASSERT(test_bit(PTLRPC_CTX_CACHED_BIT, &ctx->cc_flags) == 0); + + /* must revoke the key, or others may treat it as newly created */ + key_revoke_locked(key); + + key->payload.data = NULL; + ctx2gctx_keyring(ctx)->gck_key = NULL; + + /* once ctx get split from key, the timer is meaningless */ + ctx_clear_timer_kr(ctx); + + ctx_put_kr(ctx, 1); + key_put(key); +} + +/* + * given a ctx, unbind with its coupled key, if any. + * unbind could only be called once, so we don't worry the key be released + * by someone else. + */ +static void unbind_ctx_kr(struct ptlrpc_cli_ctx *ctx) +{ + struct key *key = ctx2gctx_keyring(ctx)->gck_key; + + if (key) { + LASSERT(key->payload.data == ctx); + + key_get(key); + down_write(&key->sem); + unbind_key_ctx(key, ctx); + up_write(&key->sem); + key_put(key); + } +} + +/* + * given a key, unbind with its coupled ctx, if any. + * caller must hold write lock, as well as a ref of the key. + */ +static void unbind_key_locked(struct key *key) +{ + struct ptlrpc_cli_ctx *ctx = key->payload.data; + + if (ctx) + unbind_key_ctx(key, ctx); +} + +/* + * unlist a ctx, and unbind from coupled key + */ +static void kill_ctx_kr(struct ptlrpc_cli_ctx *ctx) +{ + if (ctx_unlist_kr(ctx, 0)) + unbind_ctx_kr(ctx); +} + +/* + * given a key, unlist and unbind with the coupled ctx (if any). + * caller must hold write lock, as well as a ref of the key. + */ +static void kill_key_locked(struct key *key) +{ + struct ptlrpc_cli_ctx *ctx = key->payload.data; + + if (ctx && ctx_unlist_kr(ctx, 0)) + unbind_key_locked(key); +} + +/* + * caller should hold one ref on contexts in freelist. + */ +static void dispose_ctx_list_kr(struct hlist_head *freelist) +{ + struct hlist_node *next; + struct ptlrpc_cli_ctx *ctx; + struct gss_cli_ctx *gctx; + + hlist_for_each_entry_safe(ctx, next, freelist, cc_cache) { + hlist_del_init(&ctx->cc_cache); + + /* reverse ctx: update current seq to buddy svcctx if exist. + * ideally this should be done at gss_cli_ctx_finalize(), but + * the ctx destroy could be delayed by: + * 1) ctx still has reference; + * 2) ctx destroy is asynchronous; + * and reverse import call inval_all_ctx() require this be done + *_immediately_ otherwise newly created reverse ctx might copy + * the very old sequence number from svcctx. */ + gctx = ctx2gctx(ctx); + if (!rawobj_empty(&gctx->gc_svc_handle) && + sec_is_reverse(gctx->gc_base.cc_sec)) { + gss_svc_upcall_update_sequence(&gctx->gc_svc_handle, + (__u32) atomic_read(&gctx->gc_seq)); + } + + /* we need to wakeup waiting reqs here. the context might + * be forced released before upcall finished, then the + * late-arrived downcall can't find the ctx even. */ + sptlrpc_cli_ctx_wakeup(ctx); + + unbind_ctx_kr(ctx); + ctx_put_kr(ctx, 0); + } +} + +/* + * lookup a root context directly in a sec, return root ctx with a + * reference taken or NULL. + */ +static +struct ptlrpc_cli_ctx * sec_lookup_root_ctx_kr(struct ptlrpc_sec *sec) +{ + struct gss_sec_keyring *gsec_kr = sec2gsec_keyring(sec); + struct ptlrpc_cli_ctx *ctx = NULL; + + spin_lock(&sec->ps_lock); + + ctx = gsec_kr->gsk_root_ctx; + + if (ctx == NULL && unlikely(sec_is_reverse(sec))) { + struct ptlrpc_cli_ctx *tmp; + + /* reverse ctx, search root ctx in list, choose the one + * with shortest expire time, which is most possibly have + * an established peer ctx at client side. */ + hlist_for_each_entry(tmp, &gsec_kr->gsk_clist, cc_cache) { + if (ctx == NULL || ctx->cc_expire == 0 || + ctx->cc_expire > tmp->cc_expire) { + ctx = tmp; + /* promote to be root_ctx */ + gsec_kr->gsk_root_ctx = ctx; + } + } + } + + if (ctx) { + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + LASSERT(!hlist_empty(&gsec_kr->gsk_clist)); + atomic_inc(&ctx->cc_refcount); + } + + spin_unlock(&sec->ps_lock); + + return ctx; +} + +#define RVS_CTX_EXPIRE_NICE (10) + +static +void rvs_sec_install_root_ctx_kr(struct ptlrpc_sec *sec, + struct ptlrpc_cli_ctx *new_ctx, + struct key *key) +{ + struct gss_sec_keyring *gsec_kr = sec2gsec_keyring(sec); + struct ptlrpc_cli_ctx *ctx; + cfs_time_t now; + ENTRY; + + LASSERT(sec_is_reverse(sec)); + + spin_lock(&sec->ps_lock); + + now = cfs_time_current_sec(); + + /* set all existing ctxs short expiry */ + hlist_for_each_entry(ctx, &gsec_kr->gsk_clist, cc_cache) { + if (ctx->cc_expire > now + RVS_CTX_EXPIRE_NICE) { + ctx->cc_early_expire = 1; + ctx->cc_expire = now + RVS_CTX_EXPIRE_NICE; + } + } + + /* if there's root_ctx there, instead obsolete the current + * immediately, we leave it continue operating for a little while. + * hopefully when the first backward rpc with newest ctx send out, + * the client side already have the peer ctx well established. */ + ctx_enlist_kr(new_ctx, gsec_kr->gsk_root_ctx ? 0 : 1, 1); + + if (key) + bind_key_ctx(key, new_ctx); + + spin_unlock(&sec->ps_lock); +} + +static void construct_key_desc(void *buf, int bufsize, + struct ptlrpc_sec *sec, uid_t uid) +{ + snprintf(buf, bufsize, "%d@%x", uid, sec->ps_id); + ((char *)buf)[bufsize - 1] = '\0'; +} + +/**************************************** + * sec apis * + ****************************************/ + +static +struct ptlrpc_sec * gss_sec_create_kr(struct obd_import *imp, + struct ptlrpc_svc_ctx *svcctx, + struct sptlrpc_flavor *sf) +{ + struct gss_sec_keyring *gsec_kr; + ENTRY; + + OBD_ALLOC(gsec_kr, sizeof(*gsec_kr)); + if (gsec_kr == NULL) + RETURN(NULL); + + INIT_HLIST_HEAD(&gsec_kr->gsk_clist); + gsec_kr->gsk_root_ctx = NULL; + mutex_init(&gsec_kr->gsk_root_uc_lock); +#ifdef HAVE_KEYRING_UPCALL_SERIALIZED + mutex_init(&gsec_kr->gsk_uc_lock); +#endif + + if (gss_sec_create_common(&gsec_kr->gsk_base, &gss_policy_keyring, + imp, svcctx, sf)) + goto err_free; + + if (svcctx != NULL && + sec_install_rctx_kr(&gsec_kr->gsk_base.gs_base, svcctx)) { + gss_sec_destroy_common(&gsec_kr->gsk_base); + goto err_free; + } + + RETURN(&gsec_kr->gsk_base.gs_base); + +err_free: + OBD_FREE(gsec_kr, sizeof(*gsec_kr)); + RETURN(NULL); +} + +static +void gss_sec_destroy_kr(struct ptlrpc_sec *sec) +{ + struct gss_sec *gsec = sec2gsec(sec); + struct gss_sec_keyring *gsec_kr = sec2gsec_keyring(sec); + + CDEBUG(D_SEC, "destroy %s@%p\n", sec->ps_policy->sp_name, sec); + + LASSERT(hlist_empty(&gsec_kr->gsk_clist)); + LASSERT(gsec_kr->gsk_root_ctx == NULL); + + gss_sec_destroy_common(gsec); + + OBD_FREE(gsec_kr, sizeof(*gsec_kr)); +} + +static inline int user_is_root(struct ptlrpc_sec *sec, struct vfs_cred *vcred) +{ + /* except the ROOTONLY flag, treat it as root user only if real uid + * is 0, euid/fsuid being 0 are handled as setuid scenarios */ + if (sec_is_rootonly(sec) || (vcred->vc_uid == 0)) + return 1; + else + return 0; +} + +/* + * unlink request key from it's ring, which is linked during request_key(). + * sadly, we have to 'guess' which keyring it's linked to. + * + * FIXME this code is fragile, depend on how request_key_link() is implemented. + */ +static void request_key_unlink(struct key *key) +{ + struct task_struct *tsk = current; + struct key *ring; + + switch (key_cred(tsk)->jit_keyring) { + case KEY_REQKEY_DEFL_DEFAULT: + case KEY_REQKEY_DEFL_THREAD_KEYRING: + ring = key_get(key_cred(tsk)->thread_keyring); + if (ring) + break; + case KEY_REQKEY_DEFL_PROCESS_KEYRING: + ring = key_get(key_tgcred(tsk)->process_keyring); + if (ring) + break; + case KEY_REQKEY_DEFL_SESSION_KEYRING: + rcu_read_lock(); + ring = key_get(rcu_dereference(key_tgcred(tsk) + ->session_keyring)); + rcu_read_unlock(); + if (ring) + break; + case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: + ring = key_get(key_cred(tsk)->user->session_keyring); + break; + case KEY_REQKEY_DEFL_USER_KEYRING: + ring = key_get(key_cred(tsk)->user->uid_keyring); + break; + case KEY_REQKEY_DEFL_GROUP_KEYRING: + default: + LBUG(); + } + + LASSERT(ring); + key_unlink(ring, key); + key_put(ring); +} + +static +struct ptlrpc_cli_ctx * gss_sec_lookup_ctx_kr(struct ptlrpc_sec *sec, + struct vfs_cred *vcred, + int create, int remove_dead) +{ + struct obd_import *imp = sec->ps_import; + struct gss_sec_keyring *gsec_kr = sec2gsec_keyring(sec); + struct ptlrpc_cli_ctx *ctx = NULL; + unsigned int is_root = 0, create_new = 0; + struct key *key; + char desc[24]; + char *coinfo; + int coinfo_size; + char *co_flags = ""; + ENTRY; + + LASSERT(imp != NULL); + + is_root = user_is_root(sec, vcred); + + /* a little bit optimization for root context */ + if (is_root) { + ctx = sec_lookup_root_ctx_kr(sec); + /* + * Only lookup directly for REVERSE sec, which should + * always succeed. + */ + if (ctx || sec_is_reverse(sec)) + RETURN(ctx); + } + + LASSERT(create != 0); + + /* for root context, obtain lock and check again, this time hold + * the root upcall lock, make sure nobody else populated new root + * context after last check. */ + if (is_root) { + mutex_lock(&gsec_kr->gsk_root_uc_lock); + + ctx = sec_lookup_root_ctx_kr(sec); + if (ctx) + goto out; + + /* update reverse handle for root user */ + sec2gsec(sec)->gs_rvs_hdl = gss_get_next_ctx_index(); + + switch (sec->ps_part) { + case LUSTRE_SP_MDT: + co_flags = "m"; + break; + case LUSTRE_SP_OST: + co_flags = "o"; + break; + case LUSTRE_SP_MGC: + co_flags = "rmo"; + break; + case LUSTRE_SP_CLI: + co_flags = "r"; + break; + case LUSTRE_SP_MGS: + default: + LBUG(); + } + } + + /* in case of setuid, key will be constructed as owner of fsuid/fsgid, + * but we do authentication based on real uid/gid. the key permission + * bits will be exactly as POS_ALL, so only processes who subscribed + * this key could have the access, although the quota might be counted + * on others (fsuid/fsgid). + * + * keyring will use fsuid/fsgid as upcall parameters, so we have to + * encode real uid/gid into callout info. + */ + + construct_key_desc(desc, sizeof(desc), sec, vcred->vc_uid); + + /* callout info format: + * secid:mech:uid:gid:flags:svc_type:peer_nid:target_uuid + */ + coinfo_size = sizeof(struct obd_uuid) + MAX_OBD_NAME + 64; + OBD_ALLOC(coinfo, coinfo_size); + if (coinfo == NULL) + goto out; + + snprintf(coinfo, coinfo_size, "%d:%s:%u:%u:%s:%d:"LPX64":%s", + sec->ps_id, sec2gsec(sec)->gs_mech->gm_name, + vcred->vc_uid, vcred->vc_gid, + co_flags, import_to_gss_svc(imp), + imp->imp_connection->c_peer.nid, imp->imp_obd->obd_name); + + CDEBUG(D_SEC, "requesting key for %s\n", desc); + + keyring_upcall_lock(gsec_kr); + key = request_key(&gss_key_type, desc, coinfo); + keyring_upcall_unlock(gsec_kr); + + OBD_FREE(coinfo, coinfo_size); + + if (IS_ERR(key)) { + CERROR("failed request key: %ld\n", PTR_ERR(key)); + goto out; + } + CDEBUG(D_SEC, "obtained key %08x for %s\n", key->serial, desc); + + /* once payload.data was pointed to a ctx, it never changes until + * we de-associate them; but parallel request_key() may return + * a key with payload.data == NULL at the same time. so we still + * need wirtelock of key->sem to serialize them. */ + down_write(&key->sem); + + if (likely(key->payload.data != NULL)) { + ctx = key->payload.data; + + LASSERT(atomic_read(&ctx->cc_refcount) >= 1); + LASSERT(ctx2gctx_keyring(ctx)->gck_key == key); + LASSERT(atomic_read(&key->usage) >= 2); + + /* simply take a ref and return. it's upper layer's + * responsibility to detect & replace dead ctx. */ + atomic_inc(&ctx->cc_refcount); + } else { + /* pre initialization with a cli_ctx. this can't be done in + * key_instantiate() because we'v no enough information + * there. */ + ctx = ctx_create_kr(sec, vcred); + if (ctx != NULL) { + ctx_enlist_kr(ctx, is_root, 0); + bind_key_ctx(key, ctx); + + ctx_start_timer_kr(ctx, KEYRING_UPCALL_TIMEOUT); + + CDEBUG(D_SEC, "installed key %p <-> ctx %p (sec %p)\n", + key, ctx, sec); + } else { + /* we'd prefer to call key_revoke(), but we more like + * to revoke it within this key->sem locked period. */ + key_revoke_locked(key); + } + + create_new = 1; + } + + up_write(&key->sem); + + if (is_root && create_new) + request_key_unlink(key); + + key_put(key); +out: + if (is_root) + mutex_unlock(&gsec_kr->gsk_root_uc_lock); + RETURN(ctx); +} + +static +void gss_sec_release_ctx_kr(struct ptlrpc_sec *sec, + struct ptlrpc_cli_ctx *ctx, + int sync) +{ + LASSERT(atomic_read(&sec->ps_refcount) > 0); + LASSERT(atomic_read(&ctx->cc_refcount) == 0); + ctx_release_kr(ctx, sync); +} + +/* + * flush context of normal user, we must resort to keyring itself to find out + * contexts which belong to me. + * + * Note here we suppose only to flush _my_ context, the "uid" will + * be ignored in the search. + */ +static +void flush_user_ctx_cache_kr(struct ptlrpc_sec *sec, + uid_t uid, + int grace, int force) +{ + struct key *key; + char desc[24]; + + /* nothing to do for reverse or rootonly sec */ + if (sec_is_reverse(sec) || sec_is_rootonly(sec)) + return; + + construct_key_desc(desc, sizeof(desc), sec, uid); + + /* there should be only one valid key, but we put it in the + * loop in case of any weird cases */ + for (;;) { + key = request_key(&gss_key_type, desc, NULL); + if (IS_ERR(key)) { + CDEBUG(D_SEC, "No more key found for current user\n"); + break; + } + + down_write(&key->sem); + + kill_key_locked(key); + + /* kill_key_locked() should usually revoke the key, but we + * revoke it again to make sure, e.g. some case the key may + * not well coupled with a context. */ + key_revoke_locked(key); + + up_write(&key->sem); + + key_put(key); + } +} + +/* + * flush context of root or all, we iterate through the list. + */ +static +void flush_spec_ctx_cache_kr(struct ptlrpc_sec *sec, + uid_t uid, + int grace, int force) +{ + struct gss_sec_keyring *gsec_kr; + struct hlist_head freelist = HLIST_HEAD_INIT; + struct hlist_node *next; + struct ptlrpc_cli_ctx *ctx; + ENTRY; + + gsec_kr = sec2gsec_keyring(sec); + + spin_lock(&sec->ps_lock); + hlist_for_each_entry_safe(ctx, next, + &gsec_kr->gsk_clist, cc_cache) { + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + + if (uid != -1 && uid != ctx->cc_vcred.vc_uid) + continue; + + /* at this moment there's at least 2 base reference: + * key association and in-list. */ + if (atomic_read(&ctx->cc_refcount) > 2) { + if (!force) + continue; + CWARN("flush busy ctx %p(%u->%s, extra ref %d)\n", + ctx, ctx->cc_vcred.vc_uid, + sec2target_str(ctx->cc_sec), + atomic_read(&ctx->cc_refcount) - 2); + } + + set_bit(PTLRPC_CTX_DEAD_BIT, &ctx->cc_flags); + if (!grace) + clear_bit(PTLRPC_CTX_UPTODATE_BIT, &ctx->cc_flags); + + atomic_inc(&ctx->cc_refcount); + + if (ctx_unlist_kr(ctx, 1)) { + hlist_add_head(&ctx->cc_cache, &freelist); + } else { + LASSERT(atomic_read(&ctx->cc_refcount) >= 2); + atomic_dec(&ctx->cc_refcount); + } + } + spin_unlock(&sec->ps_lock); + + dispose_ctx_list_kr(&freelist); + EXIT; +} + +static +int gss_sec_flush_ctx_cache_kr(struct ptlrpc_sec *sec, + uid_t uid, int grace, int force) +{ + ENTRY; + + CDEBUG(D_SEC, "sec %p(%d, nctx %d), uid %d, grace %d, force %d\n", + sec, atomic_read(&sec->ps_refcount), + atomic_read(&sec->ps_nctx), + uid, grace, force); + + if (uid != -1 && uid != 0) + flush_user_ctx_cache_kr(sec, uid, grace, force); + else + flush_spec_ctx_cache_kr(sec, uid, grace, force); + + RETURN(0); +} + +static +void gss_sec_gc_ctx_kr(struct ptlrpc_sec *sec) +{ + struct gss_sec_keyring *gsec_kr = sec2gsec_keyring(sec); + struct hlist_head freelist = HLIST_HEAD_INIT; + struct hlist_node *next; + struct ptlrpc_cli_ctx *ctx; + ENTRY; + + CWARN("running gc\n"); + + spin_lock(&sec->ps_lock); + hlist_for_each_entry_safe(ctx, next, + &gsec_kr->gsk_clist, cc_cache) { + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + + atomic_inc(&ctx->cc_refcount); + + if (cli_ctx_check_death(ctx) && ctx_unlist_kr(ctx, 1)) { + hlist_add_head(&ctx->cc_cache, &freelist); + CWARN("unhashed ctx %p\n", ctx); + } else { + LASSERT(atomic_read(&ctx->cc_refcount) >= 2); + atomic_dec(&ctx->cc_refcount); + } + } + spin_unlock(&sec->ps_lock); + + dispose_ctx_list_kr(&freelist); + EXIT; + return; +} + +static +int gss_sec_display_kr(struct ptlrpc_sec *sec, struct seq_file *seq) +{ + struct gss_sec_keyring *gsec_kr = sec2gsec_keyring(sec); + struct hlist_node *next; + struct ptlrpc_cli_ctx *ctx; + struct gss_cli_ctx *gctx; + time_t now = cfs_time_current_sec(); + ENTRY; + + spin_lock(&sec->ps_lock); + hlist_for_each_entry_safe(ctx, next, + &gsec_kr->gsk_clist, cc_cache) { + struct key *key; + char flags_str[40]; + char mech[40]; + + gctx = ctx2gctx(ctx); + key = ctx2gctx_keyring(ctx)->gck_key; + + gss_cli_ctx_flags2str(ctx->cc_flags, + flags_str, sizeof(flags_str)); + + if (gctx->gc_mechctx) + lgss_display(gctx->gc_mechctx, mech, sizeof(mech)); + else + snprintf(mech, sizeof(mech), "N/A"); + mech[sizeof(mech) - 1] = '\0'; + + seq_printf(seq, "%p: uid %u, ref %d, expire %ld(%+ld), fl %s, " + "seq %d, win %u, key %08x(ref %d), " + "hdl "LPX64":"LPX64", mech: %s\n", + ctx, ctx->cc_vcred.vc_uid, + atomic_read(&ctx->cc_refcount), + ctx->cc_expire, + ctx->cc_expire ? ctx->cc_expire - now : 0, + flags_str, + atomic_read(&gctx->gc_seq), + gctx->gc_win, + key ? key->serial : 0, + key ? atomic_read(&key->usage) : 0, + gss_handle_to_u64(&gctx->gc_handle), + gss_handle_to_u64(&gctx->gc_svc_handle), + mech); + } + spin_unlock(&sec->ps_lock); + + RETURN(0); +} + +/**************************************** + * cli_ctx apis * + ****************************************/ + +static +int gss_cli_ctx_refresh_kr(struct ptlrpc_cli_ctx *ctx) +{ + /* upcall is already on the way */ + return 0; +} + +static +int gss_cli_ctx_validate_kr(struct ptlrpc_cli_ctx *ctx) +{ + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + LASSERT(ctx->cc_sec); + + if (cli_ctx_check_death(ctx)) { + kill_ctx_kr(ctx); + return 1; + } + + if (cli_ctx_is_ready(ctx)) + return 0; + return 1; +} + +static +void gss_cli_ctx_die_kr(struct ptlrpc_cli_ctx *ctx, int grace) +{ + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + LASSERT(ctx->cc_sec); + + cli_ctx_expire(ctx); + kill_ctx_kr(ctx); +} + +/**************************************** + * (reverse) service * + ****************************************/ + +/* + * reverse context could have nothing to do with keyrings. here we still keep + * the version which bind to a key, for future reference. + */ +#define HAVE_REVERSE_CTX_NOKEY + + +static +int sec_install_rctx_kr(struct ptlrpc_sec *sec, + struct ptlrpc_svc_ctx *svc_ctx) +{ + struct ptlrpc_cli_ctx *cli_ctx; + struct vfs_cred vcred = { 0, 0 }; + int rc; + + LASSERT(sec); + LASSERT(svc_ctx); + + cli_ctx = ctx_create_kr(sec, &vcred); + if (cli_ctx == NULL) + return -ENOMEM; + + rc = gss_copy_rvc_cli_ctx(cli_ctx, svc_ctx); + if (rc) { + CERROR("failed copy reverse cli ctx: %d\n", rc); + + ctx_put_kr(cli_ctx, 1); + return rc; + } + + rvs_sec_install_root_ctx_kr(sec, cli_ctx, NULL); + + ctx_put_kr(cli_ctx, 1); + + return 0; +} + + +/**************************************** + * service apis * + ****************************************/ + +static +int gss_svc_accept_kr(struct ptlrpc_request *req) +{ + return gss_svc_accept(&gss_policy_keyring, req); +} + +static +int gss_svc_install_rctx_kr(struct obd_import *imp, + struct ptlrpc_svc_ctx *svc_ctx) +{ + struct ptlrpc_sec *sec; + int rc; + + sec = sptlrpc_import_sec_ref(imp); + LASSERT(sec); + + rc = sec_install_rctx_kr(sec, svc_ctx); + sptlrpc_sec_put(sec); + + return rc; +} + +/**************************************** + * key apis * + ****************************************/ + +static +int gss_kt_instantiate(struct key *key, const void *data, size_t datalen) +{ + int rc; + ENTRY; + + if (data != NULL || datalen != 0) { + CERROR("invalid: data %p, len %lu\n", data, (long)datalen); + RETURN(-EINVAL); + } + + if (key->payload.data != 0) { + CERROR("key already have payload\n"); + RETURN(-EINVAL); + } + + /* link the key to session keyring, so following context negotiation + * rpc fired from user space could find this key. This will be unlinked + * automatically when upcall processes die. + * + * we can't do this through keyctl from userspace, because the upcall + * might be neither possessor nor owner of the key (setuid). + * + * the session keyring is created upon upcall, and don't change all + * the way until upcall finished, so rcu lock is not needed here. + */ + LASSERT(key_tgcred(current)->session_keyring); + + lockdep_off(); + rc = key_link(key_tgcred(current)->session_keyring, key); + lockdep_on(); + if (unlikely(rc)) { + CERROR("failed to link key %08x to keyring %08x: %d\n", + key->serial, + key_tgcred(current)->session_keyring->serial, rc); + RETURN(rc); + } + + CDEBUG(D_SEC, "key %p instantiated, ctx %p\n", key, key->payload.data); + RETURN(0); +} + +/* + * called with key semaphore write locked. it means we can operate + * on the context without fear of loosing refcount. + */ +static +int gss_kt_update(struct key *key, const void *data, size_t datalen) +{ + struct ptlrpc_cli_ctx *ctx = key->payload.data; + struct gss_cli_ctx *gctx; + rawobj_t tmpobj = RAWOBJ_EMPTY; + __u32 datalen32 = (__u32) datalen; + int rc; + ENTRY; + + if (data == NULL || datalen == 0) { + CWARN("invalid: data %p, len %lu\n", data, (long)datalen); + RETURN(-EINVAL); + } + + /* if upcall finished negotiation too fast (mostly likely because + * of local error happened) and call kt_update(), the ctx + * might be still NULL. but the key will finally be associate + * with a context, or be revoked. if key status is fine, return + * -EAGAIN to allow userspace sleep a while and call again. */ + if (ctx == NULL) { + CDEBUG(D_SEC, "update too soon: key %p(%x) flags %lx\n", + key, key->serial, key->flags); + + rc = key_validate(key); + if (rc == 0) + RETURN(-EAGAIN); + else + RETURN(rc); + } + + LASSERT(atomic_read(&ctx->cc_refcount) > 0); + LASSERT(ctx->cc_sec); + + ctx_clear_timer_kr(ctx); + + /* don't proceed if already refreshed */ + if (cli_ctx_is_refreshed(ctx)) { + CWARN("ctx already done refresh\n"); + RETURN(0); + } + + sptlrpc_cli_ctx_get(ctx); + gctx = ctx2gctx(ctx); + + rc = buffer_extract_bytes(&data, &datalen32, &gctx->gc_win, + sizeof(gctx->gc_win)); + if (rc) { + CERROR("failed extract seq_win\n"); + goto out; + } + + if (gctx->gc_win == 0) { + __u32 nego_rpc_err, nego_gss_err; + + rc = buffer_extract_bytes(&data, &datalen32, &nego_rpc_err, + sizeof(nego_rpc_err)); + if (rc) { + CERROR("failed to extrace rpc rc\n"); + goto out; + } + + rc = buffer_extract_bytes(&data, &datalen32, &nego_gss_err, + sizeof(nego_gss_err)); + if (rc) { + CERROR("failed to extrace gss rc\n"); + goto out; + } + + CERROR("negotiation: rpc err %d, gss err %x\n", + nego_rpc_err, nego_gss_err); + + rc = nego_rpc_err ? nego_rpc_err : -EACCES; + } else { + rc = rawobj_extract_local_alloc(&gctx->gc_handle, + (__u32 **) &data, &datalen32); + if (rc) { + CERROR("failed extract handle\n"); + goto out; + } + + rc = rawobj_extract_local(&tmpobj, (__u32 **) &data,&datalen32); + if (rc) { + CERROR("failed extract mech\n"); + goto out; + } + + rc = lgss_import_sec_context(&tmpobj, + sec2gsec(ctx->cc_sec)->gs_mech, + &gctx->gc_mechctx); + if (rc != GSS_S_COMPLETE) + CERROR("failed import context\n"); + else + rc = 0; + } +out: + /* we don't care what current status of this ctx, even someone else + * is operating on the ctx at the same time. we just add up our own + * opinions here. */ + if (rc == 0) { + gss_cli_ctx_uptodate(gctx); + } else { + /* this will also revoke the key. has to be done before + * wakeup waiters otherwise they can find the stale key */ + kill_key_locked(key); + + cli_ctx_expire(ctx); + + if (rc != -ERESTART) + set_bit(PTLRPC_CTX_ERROR_BIT, &ctx->cc_flags); + } + + /* let user space think it's a success */ + sptlrpc_cli_ctx_put(ctx, 1); + RETURN(0); +} + +static +int gss_kt_match(const struct key *key, const void *desc) +{ + return (strcmp(key->description, (const char *) desc) == 0); +} + +static +void gss_kt_destroy(struct key *key) +{ + ENTRY; + LASSERT(key->payload.data == NULL); + CDEBUG(D_SEC, "destroy key %p\n", key); + EXIT; +} + +static +void gss_kt_describe(const struct key *key, struct seq_file *s) +{ + if (key->description == NULL) + seq_puts(s, "[null]"); + else + seq_puts(s, key->description); +} + +static struct key_type gss_key_type = +{ + .name = "lgssc", + .def_datalen = 0, + .instantiate = gss_kt_instantiate, + .update = gss_kt_update, + .match = gss_kt_match, + .destroy = gss_kt_destroy, + .describe = gss_kt_describe, +}; + +/**************************************** + * lustre gss keyring policy * + ****************************************/ + +static struct ptlrpc_ctx_ops gss_keyring_ctxops = { + .match = gss_cli_ctx_match, + .refresh = gss_cli_ctx_refresh_kr, + .validate = gss_cli_ctx_validate_kr, + .die = gss_cli_ctx_die_kr, + .sign = gss_cli_ctx_sign, + .verify = gss_cli_ctx_verify, + .seal = gss_cli_ctx_seal, + .unseal = gss_cli_ctx_unseal, + .wrap_bulk = gss_cli_ctx_wrap_bulk, + .unwrap_bulk = gss_cli_ctx_unwrap_bulk, +}; + +static struct ptlrpc_sec_cops gss_sec_keyring_cops = { + .create_sec = gss_sec_create_kr, + .destroy_sec = gss_sec_destroy_kr, + .kill_sec = gss_sec_kill, + .lookup_ctx = gss_sec_lookup_ctx_kr, + .release_ctx = gss_sec_release_ctx_kr, + .flush_ctx_cache = gss_sec_flush_ctx_cache_kr, + .gc_ctx = gss_sec_gc_ctx_kr, + .install_rctx = gss_sec_install_rctx, + .alloc_reqbuf = gss_alloc_reqbuf, + .free_reqbuf = gss_free_reqbuf, + .alloc_repbuf = gss_alloc_repbuf, + .free_repbuf = gss_free_repbuf, + .enlarge_reqbuf = gss_enlarge_reqbuf, + .display = gss_sec_display_kr, +}; + +static struct ptlrpc_sec_sops gss_sec_keyring_sops = { + .accept = gss_svc_accept_kr, + .invalidate_ctx = gss_svc_invalidate_ctx, + .alloc_rs = gss_svc_alloc_rs, + .authorize = gss_svc_authorize, + .free_rs = gss_svc_free_rs, + .free_ctx = gss_svc_free_ctx, + .prep_bulk = gss_svc_prep_bulk, + .unwrap_bulk = gss_svc_unwrap_bulk, + .wrap_bulk = gss_svc_wrap_bulk, + .install_rctx = gss_svc_install_rctx_kr, +}; + +static struct ptlrpc_sec_policy gss_policy_keyring = { + .sp_owner = THIS_MODULE, + .sp_name = "gss.keyring", + .sp_policy = SPTLRPC_POLICY_GSS, + .sp_cops = &gss_sec_keyring_cops, + .sp_sops = &gss_sec_keyring_sops, +}; + + +int __init gss_init_keyring(void) +{ + int rc; + + rc = register_key_type(&gss_key_type); + if (rc) { + CERROR("failed to register keyring type: %d\n", rc); + return rc; + } + + rc = sptlrpc_register_policy(&gss_policy_keyring); + if (rc) { + unregister_key_type(&gss_key_type); + return rc; + } + + return 0; +} + +void __exit gss_exit_keyring(void) +{ + unregister_key_type(&gss_key_type); + sptlrpc_unregister_policy(&gss_policy_keyring); +} |