gss_keyring.c 46.85 KiB
/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=8:tabstop=8:
*
* Copyright (C) 2007 Cluster File Systems, Inc.
* Author: Eric Mei <ericm@clusterfs.com>
*
* This file is part of Lustre, http://www.lustre.org.
*
* Lustre is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* Lustre 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 for more details.
*
* You should have received a copy of the GNU General Public License
* along with Lustre; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef EXPORT_SYMTAB
# define EXPORT_SYMTAB
#endif
#define DEBUG_SUBSYSTEM S_SEC
#ifdef __KERNEL__
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/dcache.h>
#include <linux/fs.h>
#include <linux/random.h>
#include <linux/crypto.h>
#include <linux/key.h>
#include <linux/keyctl.h>
#include <linux/mutex.h>
#include <asm/atomic.h>
#else
#include <liblustre.h>
#endif
#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);
#ifndef task_aux
#define task_aux(tsk) (tsk)
#endif
/*
* 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, \
task_aux(tsk)->request_key_auth ? \
task_aux(tsk)->request_key_auth->serial : 0, \
task_aux(tsk)->thread_keyring ? \
task_aux(tsk)->thread_keyring->serial : 0, \
tsk->signal->process_keyring ? \
tsk->signal->process_keyring->serial : 0, \
tsk->signal->session_keyring ? \
tsk->signal->session_keyring->serial : 0, \
tsk->user->uid_keyring ? \
tsk->user->uid_keyring->serial : 0, \
tsk->user->session_keyring ? \
tsk->user->session_keyring->serial : 0, \
task_aux(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" \
); \
}
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);
sptlrpc_cli_ctx_wakeup(ctx);
}
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 *pos, *next;
struct ptlrpc_cli_ctx *ctx;
struct gss_cli_ctx *gctx;
hlist_for_each_entry_safe(ctx, pos, 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 hlist_node *node;
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, node, &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 hlist_node *hnode;
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, hnode, &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 *
****************************************/
staticstruct 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);
CFS_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 (task_aux(tsk)->jit_keyring) {
case KEY_REQKEY_DEFL_DEFAULT:
case KEY_REQKEY_DEFL_THREAD_KEYRING:
ring = key_get(task_aux(tsk)->thread_keyring);
if (ring)
break;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
ring = key_get(tsk->signal->process_keyring);
if (ring)
break;
case KEY_REQKEY_DEFL_SESSION_KEYRING:
rcu_read_lock();
ring = key_get(rcu_dereference(tsk->signal->session_keyring));
rcu_read_unlock();
if (ring)
break;
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
ring = key_get(tsk->user->session_keyring);
break;
case KEY_REQKEY_DEFL_USER_KEYRING:
ring = key_get(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();
co_flags = "r";
}
/* 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", 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", 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 = CFS_HLIST_HEAD_INIT;
struct hlist_node *pos, *next;
struct ptlrpc_cli_ctx *ctx;
ENTRY;
gsec_kr = sec2gsec_keyring(sec);
spin_lock(&sec->ps_lock);
hlist_for_each_entry_safe(ctx, pos, 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 = CFS_HLIST_HEAD_INIT;
struct hlist_node *pos, *next;
struct ptlrpc_cli_ctx *ctx;
ENTRY;
CWARN("running gc\n");
spin_lock(&sec->ps_lock);
hlist_for_each_entry_safe(ctx, pos, 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 *pos, *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, pos, 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
#ifdef 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;
}
#else /* ! 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 = NULL;
struct key *key;
struct vfs_cred vcred = { 0, 0 };
char desc[64];
int rc;
LASSERT(sec);
LASSERT(svc_ctx);
CWARN("called\n");
construct_key_desc(desc, sizeof(desc), sec, 0);
key = key_alloc(&gss_key_type, desc, 0, 0,
KEY_POS_ALL | KEY_USR_ALL, 1);
if (IS_ERR(key)) {
CERROR("failed to alloc key: %ld\n", PTR_ERR(key));
return PTR_ERR(key);
}
rc = key_instantiate_and_link(key, NULL, 0, NULL, NULL);
if (rc) { CERROR("failed to instantiate key: %d\n", rc);
goto err_revoke;
}
down_write(&key->sem);
LASSERT(key->payload.data == NULL);
cli_ctx = ctx_create_kr(sec, &vcred);
if (cli_ctx == NULL) {
rc = -ENOMEM;
goto err_up;
}
rc = gss_copy_rvc_cli_ctx(cli_ctx, svc_ctx);
if (rc) {
CERROR("failed copy reverse cli ctx: %d\n", rc);
goto err_put;
}
rvs_sec_install_root_ctx_kr(sec, cli_ctx, key);
ctx_put_kr(cli_ctx, 1);
up_write(&key->sem);
rc = 0;
CWARN("ok!\n");
out:
key_put(key);
return rc;
err_put:
ctx_put_kr(cli_ctx, 1);
err_up:
up_write(&key->sem);
err_revoke:
key_revoke(key);
goto out;
}
#endif /* HAVE_REVERSE_CTX_NOKEY */
/****************************************
* 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 %d\n", data, 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(cfs_current()->signal->session_keyring);
rc = key_link(cfs_current()->signal->session_keyring, key);
if (unlikely(rc)) {
CERROR("failed to link key %08x to keyring %08x: %d\n",
key->serial,
cfs_current()->signal->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;
int rc;
ENTRY;
if (data == NULL || datalen == 0) {
CWARN("invalid: data %p, len %d\n", data, datalen);
RETURN(-EINVAL);
}
/* there's a race between userspace parent - child processes. if
* child finish negotiation too fast 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) {
CWARN("race in userspace. 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");
sptlrpc_cli_ctx_wakeup(ctx);
RETURN(0);
}
sptlrpc_cli_ctx_get(ctx);
gctx = ctx2gctx(ctx);
rc = buffer_extract_bytes(&data, &datalen, &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, &datalen, &nego_rpc_err,
sizeof(nego_rpc_err));
if (rc) {
CERROR("failed to extrace rpc rc\n");
goto out;
}
rc = buffer_extract_bytes(&data, &datalen, &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, &datalen);
if (rc) {
CERROR("failed extract handle\n");
goto out;
}
rc = rawobj_extract_local(&tmpobj, (__u32 **) &data, &datalen);
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);
}
sptlrpc_cli_ctx_wakeup(ctx);
/* 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,
.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);
}