Viewing: gss_keyring.c
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
* Copyright (c) 2012, 2014, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
*
* Author: Eric Mei <ericm@clusterfs.com>
*/
#define DEBUG_SUBSYSTEM S_SEC
#include <linux/init.h>
#include <linux/module.h>
#include <linux/atomic.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 <linux/list.h>
#include <lustre_compat/linux/timer.h>
#include <obd.h>
#include <obd_class.h>
#include <obd_support.h>
#include <uapi/linux/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"
#ifdef HAVE_GET_REQUEST_KEY_AUTH
#include <keys/request_key_auth-type.h>
#endif
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);
static void request_key_unlink(struct key *key, bool fullsearch);
/*
* 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)
/* Check caller's namespace in gss_keyring upcall */
unsigned int gss_check_upcall_ns = 1;
/****************************************
* internal helpers *
****************************************/
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_invalidate_locked(struct key *key)
{
set_bit(KEY_FLAG_INVALIDATED, &key->flags);
}
static void ctx_upcall_timeout_kr(cfs_timer_cb_arg_t data)
{
struct gss_cli_ctx_keyring *gctx_kr = cfs_from_timer(gctx_kr,
data, gck_timer);
struct ptlrpc_cli_ctx *ctx = &(gctx_kr->gck_base.gc_base);
struct obd_import *imp = ctx->cc_sec->ps_import;
struct key *key = gctx_kr->gck_key;
if (key)
CDEBUG(D_SEC,
"%s: GSS context (%p) negotiation timeout, invalidating key (%p)\n",
imp->imp_obd->obd_name, ctx, key);
else
CDEBUG(D_SEC,
"%s: GSS context (%p) negotiation timeout, ignoring already unlinked key\n",
imp->imp_obd->obd_name, ctx);
cli_ctx_expire(ctx);
if (key)
key_invalidate_locked(key);
}
static void ctx_start_timer_kr(struct ptlrpc_cli_ctx *ctx, time64_t 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 %llds\n", ctx, timeout);
cfs_timer_setup(timer, ctx_upcall_timeout_kr,
(unsigned long)gctx_kr, 0);
timer->expires = cfs_time_seconds(timeout) + jiffies;
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;
CDEBUG(D_SEC, "ctx %p, key %p\n", ctx, gctx_kr->gck_key);
timer_delete_sync(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;
cfs_timer_setup(&gctx_kr->gck_timer, NULL, 0, 0);
ctx = &gctx_kr->gck_base.gc_base;
if (gss_cli_ctx_init_common(sec, ctx, &gss_keyring_ctxops, vcred)) {
OBD_FREE_PTR(gctx_kr);
return NULL;
}
ctx->cc_expire = ktime_get_real_seconds() + 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);
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;
}
/*
* Get specific payload. Newer kernels support 4 slots.
*/
static void *
key_get_payload(struct key *key, unsigned int index)
{
return key->payload.data[index];
}
/*
* Set specific payload. Newer kernels support 4 slots.
*/
static int key_set_payload(struct key *key, unsigned int index,
struct ptlrpc_cli_ctx *ctx)
{
int rc = -EINVAL;
if (index < 4) {
key->payload.data[index] = ctx;
rc = 0;
}
return rc;
}
/*
* 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(refcount_read(&key->usage) > 0);
LASSERT(ctx2gctx_keyring(ctx)->gck_key == NULL);
LASSERT(!key_get_payload(key, 0));
/* at this time context may or may not in list. */
key_get(key);
atomic_inc(&ctx->cc_refcount);
ctx2gctx_keyring(ctx)->gck_key = key;
LASSERT(!key_set_payload(key, 0, 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)
{
/* give up on invalidated or empty key,
* someone else already took care of it
*/
if (test_bit(KEY_FLAG_INVALIDATED, &key->flags) ||
key_get_payload(key, 0) != ctx) {
CDEBUG(D_SEC, "key %08x already handled\n", key->serial);
return;
}
/* must invalidate the key, or others may find it during lookup */
key_invalidate_locked(key);
request_key_unlink(key, false);
key_set_payload(key, 0, 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) {
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_get_payload(key, 0);
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_get_payload(key, 0);
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;
time64_t now = ktime_get_real_seconds();
spin_lock(&sec->ps_lock);
ctx = gsec_kr->gsk_root_ctx;
/* Need to find valid rev ctx if we do not have one yet,
* or if it is expired.
*/
if (unlikely(sec_is_reverse(sec)) &&
(ctx == NULL || ctx->cc_expire < now)) {
struct ptlrpc_cli_ctx *tmp;
/* For reverse context, browse list and pick the one with
* shortest expire time and that has not expired yet.
* This one is most likely to have an established peer context
* on client side.
*/
hlist_for_each_entry(tmp, &gsec_kr->gsk_clist, cc_cache) {
if (ctx == NULL || ctx->cc_expire == 0 ||
(tmp->cc_expire > now &&
tmp->cc_expire < ctx->cc_expire) ||
(ctx->cc_expire < now &&
tmp->cc_expire > ctx->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;
struct hlist_node *next;
time64_t now;
ENTRY;
LASSERT(sec_is_reverse(sec));
spin_lock(&sec->ps_lock);
now = ktime_get_real_seconds();
/* set all existing ctxs short expiry */
hlist_for_each_entry_safe(ctx, next, &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;
} else if (ctx != gsec_kr->gsk_root_ctx &&
ctx->cc_expire < now) {
/* unlist expired context to remove it from gsk_clist */
if (ctx_unlist_kr(ctx, 1)) {
/* release unlisted ctx to destroy it */
set_bit(PTLRPC_CTX_DEAD_BIT, &ctx->cc_flags);
ctx_release_kr(ctx, 1);
}
}
}
/* 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(atomic_read(&sec->ps_nctx) == 0);
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;
}
#ifdef HAVE_KEY_NEED_UNLINK
/* from Linux security/keys/internal.h: */
# ifndef KEY_LOOKUP_PARTIAL
# define KEY_LOOKUP_PARTIAL 0x2
# endif
#else
# define KEY_NEED_UNLINK 0
# ifndef KEY_LOOKUP_FOR_UNLINK
# define KEY_LOOKUP_FOR_UNLINK 0x4
# endif
# define KEY_LOOKUP_PARTIAL KEY_LOOKUP_FOR_UNLINK
#endif /* HAVE_KEY_NEED_UNLINK */
static struct key *_user_key(key_serial_t id)
{
key_ref_t ref;
might_sleep();
ref = lookup_user_key(id, KEY_LOOKUP_PARTIAL, KEY_NEED_UNLINK);
if (IS_ERR(ref))
return NULL;
return key_ref_to_ptr(ref);
}
static inline struct key *get_user_session_keyring(const struct cred *cred)
{
return _user_key(KEY_SPEC_USER_SESSION_KEYRING);
}
static inline struct key *get_user_keyring(const struct cred *cred)
{
return _user_key(KEY_SPEC_USER_KEYRING);
}
static inline struct key *get_session_keyring(const struct cred *cred)
{
return _user_key(KEY_SPEC_SESSION_KEYRING);
}
/*
* Get the appropriate destination keyring for the request.
*
* The keyring selected is returned with an extra reference upon it which the
* caller must release.
*/
/*
* Function inspired from the kernel's one, unfortunately not exported.
*/
static int construct_get_dest_keyring(struct key **_dest_keyring)
{
struct key *dest_keyring = *_dest_keyring;
const struct cred *cred = current_cred();
if (dest_keyring) {
/* the caller supplied one */
key_get(dest_keyring);
return 0;
}
switch (cred->jit_keyring) {
case KEY_REQKEY_DEFL_DEFAULT:
case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
#ifdef HAVE_GET_REQUEST_KEY_AUTH
if (cred->request_key_auth) {
struct request_key_auth *rka;
struct key *authkey = cred->request_key_auth;
down_read(&authkey->sem);
rka = get_request_key_auth(authkey);
if (!test_bit(KEY_FLAG_REVOKED, &authkey->flags))
dest_keyring = key_get(rka->dest_keyring);
up_read(&authkey->sem);
if (dest_keyring)
break;
}
#endif
fallthrough;
case KEY_REQKEY_DEFL_THREAD_KEYRING:
dest_keyring = key_get(cred->thread_keyring);
if (dest_keyring)
break;
fallthrough;
case KEY_REQKEY_DEFL_PROCESS_KEYRING:
dest_keyring = key_get(cred->process_keyring);
if (dest_keyring)
break;
fallthrough;
case KEY_REQKEY_DEFL_SESSION_KEYRING:
dest_keyring = key_get(cred->session_keyring);
if (dest_keyring) {
if (!test_bit(KEY_FLAG_REVOKED, &dest_keyring->flags))
break;
key_put(dest_keyring);
}
fallthrough;
case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
dest_keyring = get_user_session_keyring(cred);
break;
case KEY_REQKEY_DEFL_USER_KEYRING:
dest_keyring = get_user_keyring(cred);
break;
case KEY_REQKEY_DEFL_GROUP_KEYRING:
default:
LBUG();
}
*_dest_keyring = dest_keyring;
return 0;
}
/*
* Unlink key from its keyring, which was linked during request_key().
*/
static void request_key_unlink(struct key *key, bool fullsearch)
{
kuid_t kuid_orig = current_cred()->user->uid;
#ifdef HAVE_USER_UID_KEYRING
struct key *root_uid_keyring = NULL;
#endif
const struct cred *old_cred = NULL;
struct cred *new_cred = NULL;
struct key *ring = NULL;
uid_t uid, key_uid;
int res;
uid = from_kuid(current_user_ns(), kuid_orig);
key_uid = from_kuid(&init_user_ns, key->uid);
/* unlink key with user's creds if it's a user key */
if (key_uid != uid) {
new_cred = prepare_creds();
if (new_cred == NULL)
goto search;
new_cred->uid = key->uid;
new_cred->user->uid = key->uid;
if (new_cred->user_ns != &init_user_ns) {
put_user_ns(new_cred->user_ns);
new_cred->user_ns = get_user_ns(&init_user_ns);
}
#ifdef HAVE_USER_UID_KEYRING
root_uid_keyring = current_cred()->user->uid_keyring;
new_cred->user->uid_keyring = NULL;
#endif
old_cred = override_creds(new_cred);
}
/* User keys are linked to the user keyring. So get it now. */
if (key_uid && !fullsearch) {
/* Getting a key(ring) normally increases its refcount by 1.
* But if we overrode creds above, calling get_user_keyring()
* will add one more ref, because of the user switch.
*/
ring = get_user_keyring(current_cred());
} else {
search:
if (construct_get_dest_keyring(&ring))
ring = NULL;
}
if (ring) {
res = key_unlink(ring, key);
CDEBUG(D_SEC,
"Unlink key %08x (%p) from keyring %08x: %d\n",
key->serial, key, ring->serial, res);
/* matches key_get()/get_user_keyring() above */
key_put(ring);
} else {
CDEBUG(D_SEC,
"Missing keyring, key %08x (%p) could not be unlinked, ignored\n",
key->serial, key);
}
if (old_cred) {
revert_creds(old_cred);
put_cred(new_cred);
current_cred()->user->uid = kuid_orig;
#ifdef HAVE_USER_UID_KEYRING
/* We are switching creds back, so need to drop ref on keyring
* for kernel implementation based on user keyring pinned from
* the user_struct struct.
*/
if (key_uid && !fullsearch)
key_put(ring);
if (root_uid_keyring)
current_cred()->user->uid_keyring = root_uid_keyring;
#endif
}
}
/* SSK key desc is in the form "lustre:<fsname>:<client uuid>" */
#define GSS_SK_KEY_DESC_SZ (9 + MTI_NAME_MAXLEN + UUID_MAX)
/* Rename SSK key that was inserted in the kernel keyring at mount specifically
* for this client, so that it uses a key description in the form
* "lustre:<fsname>:<client uuid>". Having the client UUID in the key desc
* allows request_key() to find this client-specific key by putting the UUID
* into the callout info for context negotiation that happens in userspace.
*/
int gss_rename_sk_key(key_serial_t skid, const char *fsname, const char *uuid)
{
key_ref_t orig_key_ref, user_keyring_ref, new_key_ref;
const struct user_key_payload *ukp;
struct key *orig_key, *user_kr;
char desc[GSS_SK_KEY_DESC_SZ];
size_t buflen;
ssize_t plen;
void *buf;
int rc = 0;
ENTRY;
/* no key id, nothing to do */
if (likely(!skid))
RETURN(0);
/* find original key, knowing its serial */
orig_key_ref = lookup_user_key(skid, 0, KEY_NEED_SEARCH);
if (IS_ERR(orig_key_ref)) {
rc = PTR_ERR(orig_key_ref);
CDEBUG(D_SEC, "%s:%s: lookup_user_key(%d) failed: rc = %d\n",
fsname, uuid, skid, rc);
/* ignore error in case original key is not found */
RETURN(0);
}
orig_key = key_ref_to_ptr(orig_key_ref);
buflen = sizeof(struct sk_keyfile_config);
OBD_ALLOC(buf, buflen);
if (!buf)
GOTO(out_put1, rc = -ENOMEM);
/* read and copy payload safely under RCU */
rcu_read_lock();
ukp = user_key_payload_rcu(orig_key);
if (!ukp) {
rcu_read_unlock();
CDEBUG(D_SEC, "%s:%s: no payload on key %d\n",
fsname, uuid, skid);
GOTO(out_free, rc = -ENODATA);
}
plen = ukp->datalen;
if (plen > buflen) {
rcu_read_unlock();
CERROR("%s:%s: key %d: invalid SSK payload size %zd > %zu\n",
fsname, uuid, skid, plen, buflen);
GOTO(out_free, rc = -EINVAL);
}
memcpy(buf, ukp->data, plen);
rcu_read_unlock();
/* get ref to user keyring */
user_keyring_ref = lookup_user_key(KEY_SPEC_USER_KEYRING, 0,
KEY_NEED_WRITE);
if (IS_ERR(user_keyring_ref)) {
rc = PTR_ERR(user_keyring_ref);
CDEBUG(D_SEC, "%s:%s: lookup_user_keyring failed: rc = %d\n",
fsname, uuid, rc);
GOTO(out_free, rc);
}
user_kr = key_ref_to_ptr(user_keyring_ref);
/* create key with original payload and new desc
* in the form "lustre:<fsname>:<client uuid>"
*/
snprintf(desc, sizeof(desc), "lustre:%s:%s", fsname, uuid);
new_key_ref = key_create_or_update(user_keyring_ref, "user", desc,
buf, (size_t)plen,
KEY_POS_ALL | KEY_USR_ALL |
KEY_GRP_ALL | KEY_OTH_ALL,
0);
if (IS_ERR(new_key_ref)) {
rc = PTR_ERR(new_key_ref);
CDEBUG(D_SEC,
"key_create_or_update(%d) with desc %s failed: rc= %d\n",
skid, desc, rc);
GOTO(out_put2, rc);
}
CDEBUG(D_SEC, "installed key %d with desc %s\n",
key_ref_to_ptr(new_key_ref)->serial, desc);
key_ref_put(new_key_ref);
/* now original key can be removed */
rc = key_unlink(user_kr, orig_key);
CDEBUG(D_SEC, "%s:%s: key_unlink(%d) %s: rc = %d\n",
fsname, uuid, skid, rc ? "failed" : "success", rc);
/* ignore error in case original key is not removed */
rc = 0;
out_put2:
key_put(user_kr);
out_free:
OBD_FREE(buf, buflen);
out_put1:
key_put(orig_key);
RETURN(rc);
}
EXPORT_SYMBOL(gss_rename_sk_key);
/* Cleanup SSK key that was inserted in the kernel keyring specifically
* for this client, in the form "lustre:<fsname>:<client uuid>".
*/
void gss_cleanup_sk_key(key_serial_t skid, const char *fsname, const char *uuid)
{
key_ref_t orig_key_ref, user_keyring_ref, key_ref;
struct key *orig_key, *target_key, *user_kr;
char desc[GSS_SK_KEY_DESC_SZ];
int rc;
ENTRY;
/* no key id, nothing to do */
if (likely(!skid))
RETURN_EXIT;
snprintf(desc, sizeof(desc), "lustre:%s:%s", fsname, uuid);
/* get ref to user keyring */
user_keyring_ref = lookup_user_key(KEY_SPEC_USER_KEYRING, 0,
KEY_NEED_WRITE);
if (IS_ERR(user_keyring_ref)) {
CDEBUG(D_SEC, "%s:%s: lookup_user_keyring failed: rc = %ld\n",
fsname, uuid, PTR_ERR(user_keyring_ref));
RETURN_EXIT;
}
user_kr = key_ref_to_ptr(user_keyring_ref);
/* find key to remove */
#ifdef HAVE_KEYRING_SEARCH_4ARGS
key_ref = keyring_search(user_keyring_ref, &key_type_user, desc, false);
#else
key_ref = keyring_search(user_keyring_ref, &key_type_user, desc);
#endif
if (!IS_ERR(key_ref)) {
/* unlink the key */
target_key = key_ref_to_ptr(key_ref);
rc = key_unlink(user_kr, target_key);
CDEBUG(D_SEC, "key_unlink(%d) with desc %s %s: rc = %d\n",
target_key->serial, desc, rc ? "failed" : "success", rc);
key_put(target_key);
}
/* find and remove original key, in case it was left behind */
orig_key_ref = lookup_user_key(skid, 0, KEY_NEED_SEARCH);
if (!IS_ERR(orig_key_ref)) {
orig_key = key_ref_to_ptr(orig_key_ref);
rc = key_unlink(user_kr, orig_key);
CDEBUG(D_SEC, "%s:%s: key_unlink(%d) %s: rc = %d\n",
fsname, uuid, skid, rc ? "failed" : "success", rc);
key_put(orig_key);
}
key_put(user_kr);
RETURN_EXIT;
}
EXPORT_SYMBOL(gss_cleanup_sk_key);
/**
* \retval a valid context on success
* \retval -ev error number or NULL on error
*/
static
struct ptlrpc_cli_ctx * gss_sec_lookup_ctx_kr(struct ptlrpc_sec *sec,
struct vfs_cred *vcred,
int create, int remove_dead)
{
const size_t sizeof_u32 = sizeof(u32) * 2 + 3; /* string + : */
const size_t sizeof_u64 = sizeof(u64) * 2 + 3; /* string + : */
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;
const struct cred *old_cred = NULL;
struct cred *new_cred = NULL;
struct key *key;
char desc[24];
char *coinfo;
int coinfo_size;
const char *sec_part_flags = "";
char svc_flag = '-';
pid_t caller_pid;
struct lnet_nid primary;
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);
}
if (!create)
RETURN(ERR_PTR(-ENODATA));
/* 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:
sec_part_flags = "m";
break;
case LUSTRE_SP_OST:
sec_part_flags = "o";
break;
case LUSTRE_SP_MGC:
sec_part_flags = "rmo";
break;
case LUSTRE_SP_CLI:
sec_part_flags = "r";
break;
case LUSTRE_SP_MGS:
default:
LBUG();
}
switch (SPTLRPC_FLVR_SVC(sec->ps_flvr.sf_rpc)) {
case SPTLRPC_SVC_NULL:
svc_flag = 'n';
break;
case SPTLRPC_SVC_AUTH:
svc_flag = 'a';
break;
case SPTLRPC_SVC_INTG:
svc_flag = 'i';
break;
case SPTLRPC_SVC_PRIV:
svc_flag = 'p';
break;
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.
*/
/* But first we need to make sure the obd type is supported */
if (strcmp(imp->imp_obd->obd_type->typ_name, LUSTRE_MDC_NAME) &&
strcmp(imp->imp_obd->obd_type->typ_name, LUSTRE_OSC_NAME) &&
strcmp(imp->imp_obd->obd_type->typ_name, LUSTRE_MGC_NAME) &&
strcmp(imp->imp_obd->obd_type->typ_name, LUSTRE_LWP_NAME) &&
strcmp(imp->imp_obd->obd_type->typ_name, LUSTRE_OSP_NAME)) {
CERROR("obd %s is not a supported device\n",
imp->imp_obd->obd_name);
GOTO(out, ctx = NULL);
}
construct_key_desc(desc, sizeof(desc), sec, vcred->vc_uid);
/* callout info format */
coinfo_size = sizeof_u32 /* secid */ +
8 /* mech */ +
sizeof_u32 /* uid */ +
sizeof_u32 /* gid */ +
4 /* sec_flags */ +
2 /* svc_flag */ +
sizeof_u32 /* svc_type */ +
sizeof_u64 /* peer_nid */ +
MAX_OBD_NAME + 1 /* target_uuid */ +
sizeof_u64 /* self_nid */ +
sizeof_u32 /* pid */ +
UUID_MAX + 1 /* client_uuid */ +
1;
OBD_ALLOC(coinfo, coinfo_size);
if (coinfo == NULL)
goto out;
/* Last callout parameter is pid of process whose namespace will be used
* for credentials' retrieval.
*/
if (gss_check_upcall_ns) {
/* For user's credentials (in which case sec_part_flags is
* empty), use current PID instead of import's reference
* PID to get reference namespace.
*/
if (sec_part_flags[0] == '\0')
caller_pid = current->pid;
else
caller_pid = imp->imp_sec_refpid;
} else {
/* Do not switch namespace in gss keyring upcall. */
caller_pid = 0;
}
LNetLocalPrimaryNID(&primary);
/* FIXME !! Needs to support larger NIDs */
snprintf(coinfo, coinfo_size,
"%d:%s:%u:%u:%s:%c:%d:%#llx:%s:%#llx:%d:%s",
sec->ps_id, sec2gsec(sec)->gs_mech->gm_name,
vcred->vc_uid, vcred->vc_gid,
sec_part_flags, svc_flag, import_to_gss_svc(imp),
lnet_nid_to_nid4(&imp->imp_connection->c_peer.nid),
imp->imp_obd->obd_name,
lnet_nid_to_nid4(&primary),
caller_pid, obd_uuid2str(&imp->imp_obd->obd_uuid));
CDEBUG(D_SEC, "requesting key for %s\n", desc);
if (vcred->vc_uid) {
new_cred = prepare_creds();
if (new_cred) {
new_cred->thread_keyring =
get_user_keyring(current_cred());
new_cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
old_cred = override_creds(new_cred);
}
}
keyring_upcall_lock(gsec_kr);
key = request_key(&gss_key_type, desc, coinfo);
keyring_upcall_unlock(gsec_kr);
if (old_cred) {
revert_creds(old_cred);
put_cred(new_cred);
}
OBD_FREE(coinfo, coinfo_size);
if (IS_ERR(key)) {
CERROR("%s: request key failed for uid %d: rc = %ld\n",
imp->imp_obd->obd_name, vcred->vc_uid,
PTR_ERR(key));
ctx = ERR_CAST(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);
ctx = key_get_payload(key, 0);
if (likely(ctx)) {
LASSERT(atomic_read(&ctx->cc_refcount) >= 1);
LASSERT(ctx2gctx_keyring(ctx)->gck_key == key);
LASSERT(refcount_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 {
CDEBUG(D_SEC, "invalidating key %08x (%p)\n",
key->serial, key);
key_invalidate_locked(key);
}
if (is_root)
create_new = 1;
}
up_write(&key->sem);
/* We want root keys to be linked to the session keyring.
* But internally request_key() links the key to an independent, newly
* created session keyring. Avoid that by unlinking the key from this
* keyring, to save us pain when we need to remove the key later on.
*/
if (create_new)
request_key_unlink(key, true);
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)
{
const struct cred *old_cred = NULL;
struct cred *new_cred = NULL;
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);
if (uid) {
new_cred = prepare_creds();
if (new_cred) {
new_cred->thread_keyring =
get_user_keyring(current_cred());
new_cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
old_cred = override_creds(new_cred);
}
}
/* 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: rc=%ld\n",
PTR_ERR(key));
break;
}
down_write(&key->sem);
kill_key_locked(key);
/* kill_key_locked() should usually revoke the key, but we
* invalidate it as well to completely get rid of it.
*/
key_invalidate_locked(key);
up_write(&key->sem);
key_put(key);
}
if (old_cred) {
revert_creds(old_cred);
put_cred(new_cred);
}
}
/*
* 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 ptlrpc_cli_ctx *ctx;
struct gss_cli_ctx *gctx;
struct hlist_node *next;
ENTRY;
CDEBUG(D_SEC, "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)) {
gctx = ctx2gctx(ctx);
hlist_add_head(&ctx->cc_cache, &freelist);
CWARN("%s: cleaning gss ctx hdl %#llx:%#llx\n",
ctx->cc_sec->ps_import->imp_obd->obd_name,
gss_handle_to_u64(&gctx->gc_handle),
gss_handle_to_u64(&gctx->gc_svc_handle));
} 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_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;
struct ptlrpc_connection *conn;
time64_t now = ktime_get_real_seconds();
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;
if (sec_is_reverse(sec) &&
ctx->cc_sec && ctx->cc_sec->ps_import &&
ctx->cc_sec->ps_import->imp_connection)
conn = ctx->cc_sec->ps_import->imp_connection;
else
conn = NULL;
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,
"- { %s%s%suid: %u, ctxref: %d, expire: %lld, delta: %lld, flags: [%s], seq: %d, win: %u, key: %08x, keyref: %d, hdl: \"%#llx:%#llx\", mech: \"%s\" }\n",
conn ? "peer_nid: " : "",
conn ? libcfs_nidstr(&conn->c_peer.nid) : "",
conn ? ", " : "",
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 ? refcount_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 */
struct gss_cli_ctx *gctx = ctx ? ctx2gctx(ctx) : NULL;
/* record latest sequence number in buddy svcctx */
if (gctx && !rawobj_empty(&gctx->gc_svc_handle) &&
sec_is_reverse(gctx->gc_base.cc_sec)) {
return gss_svc_upcall_update_sequence(&gctx->gc_svc_handle,
(__u32)atomic_read(&gctx->gc_seq));
}
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 = { .vc_uid = 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 = { .vc_uid = 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_get_payload(key, 0));
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, struct key_preparsed_payload *prep)
{
const void *data = prep->data;
size_t datalen = prep->datalen;
struct key *keyring;
int uid, rc;
ENTRY;
CDEBUG(D_SEC, "instantiating key %08x (%p)\n", key->serial, key);
if (data != NULL || datalen != 0) {
CERROR("invalid: data %p, len %lu\n", data, (long)datalen);
RETURN(-EINVAL);
}
if (key_get_payload(key, 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.
*
* But for end users, we want the key to be linked to the user keyring.
* This simplifies key management, makes them shared across all user
* sessions, and avoids unfortunate key leak if lfs flushctx is not
* called at user logout.
*/
uid = from_kuid(&init_user_ns, current_uid());
if (uid) {
/* Linking user keys to the user keyring is already done at this
* point by request_key() internally, thanks to the
* 'thread keyring' trick used in gss_sec_lookup_ctx_kr().
*/
CDEBUG(D_SEC,
"key %08x (%p) instantiated, ctx %p\n",
key->serial, key, key_get_payload(key, 0));
RETURN(0);
}
/* At this point we are dealing with keys for root */
keyring = get_session_keyring(current_cred());
rc = key_link(keyring, key);
if (unlikely(rc))
CERROR("failed to link key %08x to keyring %08x: %d\n",
key->serial, keyring->serial, rc);
else
CDEBUG(D_SEC,
"key %08x (%p) linked to keyring %08x and instantiated, ctx %p\n",
key->serial, key, keyring->serial,
key_get_payload(key, 0));
key_put(keyring);
RETURN(rc);
}
/*
* 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, struct key_preparsed_payload *prep)
{
const void *data = prep->data;
u32 datalen32 = (u32)prep->datalen;
struct ptlrpc_cli_ctx *ctx = key_get_payload(key, 0);
struct gss_cli_ctx *gctx;
rawobj_t tmpobj = RAWOBJ_EMPTY;
int rc;
ENTRY;
CDEBUG(D_SEC, "updating key %08x (%p)\n", key->serial, key);
if (data == NULL || datalen32 == 0) {
CWARN("invalid: data %p, len %lu\n", data, (long)datalen32);
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 %08x (%p) flags %lx\n",
key->serial, key, 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("cannot extract RPC: rc = %d\n", rc);
goto out;
}
rc = buffer_extract_bytes(&data, &datalen32, &nego_gss_err,
sizeof(nego_gss_err));
if (rc) {
CERROR("failed to extract gss rc = %d\n", rc);
goto out;
}
CERROR("negotiation: rpc err %d, gss err %x\n",
nego_rpc_err, nego_gss_err);
gctx->gc_gss_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:
CDEBUG(D_SEC, "update of key %08x (%p): %d\n", key->serial, key, rc);
/* 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);
/* In case of success, only the companion key for root ctx can
* be unbound. User keys are required to be able to retrieve
* the associated gss context.
*/
if (ctx->cc_vcred.vc_uid == 0)
unbind_key_ctx(key, ctx);
} else {
/* In case of failure, unbind the companion key for all contexts
* i.e root and regular users. It will also invalidate the key.
*/
unbind_key_ctx(key, ctx);
if (rc != -ERESTART)
set_bit(PTLRPC_CTX_ERROR_BIT, &ctx->cc_flags);
cli_ctx_expire(ctx);
}
/* let user space think it's a success */
sptlrpc_cli_ctx_put(ctx, 1);
RETURN(0);
}
static bool
gss_kt_match(const struct key *key, const struct key_match_data *match_data)
{
const char *desc = match_data->raw_data;
return strcmp(key->description, desc) == 0 &&
!test_bit(KEY_FLAG_REVOKED, &key->flags);
}
/*
* Preparse the match criterion.
*/
static int gss_kt_match_preparse(struct key_match_data *match_data)
{
match_data->lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT;
match_data->cmp = gss_kt_match;
return 0;
}
static
void gss_kt_destroy(struct key *key)
{
ENTRY;
LASSERT(!key_get_payload(key, 0));
CDEBUG(D_SEC, "destroy key %08x %p\n", key->serial, 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 void gss_kt_revoke(struct key *key)
{
CDEBUG(D_SEC, "revoking key %08x (%p) ref %d\n",
key->serial, key, refcount_read(&key->usage));
kill_key_locked(key);
CDEBUG(D_SEC, "key %08x (%p) revoked ref %d\n",
key->serial, key, refcount_read(&key->usage));
}
static struct key_type gss_key_type =
{
.name = "lgssc",
.def_datalen = 0,
.instantiate = gss_kt_instantiate,
.update = gss_kt_update,
.match_preparse = gss_kt_match_preparse,
.destroy = gss_kt_destroy,
.describe = gss_kt_describe,
.revoke = gss_kt_revoke,
};
/****************************************
* 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);
}
