1// SPDX-License-Identifier: BSD-3-Clause
   2/*
   3 * linux/net/sunrpc/auth_gss/auth_gss.c
   4 *
   5 * RPCSEC_GSS client authentication.
   6 *
   7 *  Copyright (c) 2000 The Regents of the University of Michigan.
   8 *  All rights reserved.
   9 *
  10 *  Dug Song       <dugsong@monkey.org>
  11 *  Andy Adamson   <andros@umich.edu>
  12 */
  13
  14#include <linux/module.h>
  15#include <linux/init.h>
  16#include <linux/types.h>
  17#include <linux/slab.h>
  18#include <linux/sched.h>
  19#include <linux/pagemap.h>
  20#include <linux/sunrpc/clnt.h>
  21#include <linux/sunrpc/auth.h>
  22#include <linux/sunrpc/auth_gss.h>
 
  23#include <linux/sunrpc/svcauth_gss.h>
  24#include <linux/sunrpc/gss_err.h>
  25#include <linux/workqueue.h>
  26#include <linux/sunrpc/rpc_pipe_fs.h>
  27#include <linux/sunrpc/gss_api.h>
  28#include <linux/uaccess.h>
  29#include <linux/hashtable.h>
  30
 
  31#include "../netns.h"
  32
  33#include <trace/events/rpcgss.h>
  34
  35static const struct rpc_authops authgss_ops;
  36
  37static const struct rpc_credops gss_credops;
  38static const struct rpc_credops gss_nullops;
  39
  40#define GSS_RETRY_EXPIRED 5
  41static unsigned int gss_expired_cred_retry_delay = GSS_RETRY_EXPIRED;
  42
  43#define GSS_KEY_EXPIRE_TIMEO 240
  44static unsigned int gss_key_expire_timeo = GSS_KEY_EXPIRE_TIMEO;
  45
  46#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  47# define RPCDBG_FACILITY	RPCDBG_AUTH
  48#endif
  49
  50#define GSS_CRED_SLACK		(RPC_MAX_AUTH_SIZE * 2)
  51/* length of a krb5 verifier (48), plus data added before arguments when
  52 * using integrity (two 4-byte integers): */
  53#define GSS_VERF_SLACK		100
  54
  55static DEFINE_HASHTABLE(gss_auth_hash_table, 4);
  56static DEFINE_SPINLOCK(gss_auth_hash_lock);
  57
  58struct gss_pipe {
  59	struct rpc_pipe_dir_object pdo;
  60	struct rpc_pipe *pipe;
  61	struct rpc_clnt *clnt;
  62	const char *name;
  63	struct kref kref;
  64};
  65
  66struct gss_auth {
  67	struct kref kref;
  68	struct hlist_node hash;
  69	struct rpc_auth rpc_auth;
  70	struct gss_api_mech *mech;
  71	enum rpc_gss_svc service;
  72	struct rpc_clnt *client;
  73	struct net *net;
 
  74	/*
  75	 * There are two upcall pipes; dentry[1], named "gssd", is used
  76	 * for the new text-based upcall; dentry[0] is named after the
  77	 * mechanism (for example, "krb5") and exists for
  78	 * backwards-compatibility with older gssd's.
  79	 */
  80	struct gss_pipe *gss_pipe[2];
  81	const char *target_name;
  82};
  83
  84/* pipe_version >= 0 if and only if someone has a pipe open. */
  85static DEFINE_SPINLOCK(pipe_version_lock);
  86static struct rpc_wait_queue pipe_version_rpc_waitqueue;
  87static DECLARE_WAIT_QUEUE_HEAD(pipe_version_waitqueue);
  88static void gss_put_auth(struct gss_auth *gss_auth);
  89
  90static void gss_free_ctx(struct gss_cl_ctx *);
  91static const struct rpc_pipe_ops gss_upcall_ops_v0;
  92static const struct rpc_pipe_ops gss_upcall_ops_v1;
  93
  94static inline struct gss_cl_ctx *
  95gss_get_ctx(struct gss_cl_ctx *ctx)
  96{
  97	refcount_inc(&ctx->count);
  98	return ctx;
  99}
 100
 101static inline void
 102gss_put_ctx(struct gss_cl_ctx *ctx)
 103{
 104	if (refcount_dec_and_test(&ctx->count))
 105		gss_free_ctx(ctx);
 106}
 107
 108/* gss_cred_set_ctx:
 109 * called by gss_upcall_callback and gss_create_upcall in order
 110 * to set the gss context. The actual exchange of an old context
 111 * and a new one is protected by the pipe->lock.
 112 */
 113static void
 114gss_cred_set_ctx(struct rpc_cred *cred, struct gss_cl_ctx *ctx)
 115{
 116	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 117
 118	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
 119		return;
 120	gss_get_ctx(ctx);
 121	rcu_assign_pointer(gss_cred->gc_ctx, ctx);
 122	set_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
 123	smp_mb__before_atomic();
 124	clear_bit(RPCAUTH_CRED_NEW, &cred->cr_flags);
 125}
 126
 127static const void *
 128simple_get_bytes(const void *p, const void *end, void *res, size_t len)
 129{
 130	const void *q = (const void *)((const char *)p + len);
 131	if (unlikely(q > end || q < p))
 132		return ERR_PTR(-EFAULT);
 133	memcpy(res, p, len);
 134	return q;
 135}
 136
 137static inline const void *
 138simple_get_netobj(const void *p, const void *end, struct xdr_netobj *dest)
 139{
 140	const void *q;
 141	unsigned int len;
 142
 143	p = simple_get_bytes(p, end, &len, sizeof(len));
 144	if (IS_ERR(p))
 145		return p;
 146	q = (const void *)((const char *)p + len);
 147	if (unlikely(q > end || q < p))
 148		return ERR_PTR(-EFAULT);
 149	dest->data = kmemdup(p, len, GFP_NOFS);
 150	if (unlikely(dest->data == NULL))
 151		return ERR_PTR(-ENOMEM);
 152	dest->len = len;
 153	return q;
 154}
 155
 156static struct gss_cl_ctx *
 157gss_cred_get_ctx(struct rpc_cred *cred)
 158{
 159	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
 160	struct gss_cl_ctx *ctx = NULL;
 161
 162	rcu_read_lock();
 163	ctx = rcu_dereference(gss_cred->gc_ctx);
 164	if (ctx)
 165		gss_get_ctx(ctx);
 166	rcu_read_unlock();
 167	return ctx;
 168}
 169
 170static struct gss_cl_ctx *
 171gss_alloc_context(void)
 172{
 173	struct gss_cl_ctx *ctx;
 174
 175	ctx = kzalloc(sizeof(*ctx), GFP_NOFS);
 176	if (ctx != NULL) {
 177		ctx->gc_proc = RPC_GSS_PROC_DATA;
 178		ctx->gc_seq = 1;	/* NetApp 6.4R1 doesn't accept seq. no. 0 */
 179		spin_lock_init(&ctx->gc_seq_lock);
 180		refcount_set(&ctx->count,1);
 181	}
 182	return ctx;
 183}
 184
 185#define GSSD_MIN_TIMEOUT (60 * 60)
 186static const void *
 187gss_fill_context(const void *p, const void *end, struct gss_cl_ctx *ctx, struct gss_api_mech *gm)
 188{
 189	const void *q;
 190	unsigned int seclen;
 191	unsigned int timeout;
 192	unsigned long now = jiffies;
 193	u32 window_size;
 194	int ret;
 195
 196	/* First unsigned int gives the remaining lifetime in seconds of the
 197	 * credential - e.g. the remaining TGT lifetime for Kerberos or
 198	 * the -t value passed to GSSD.
 199	 */
 200	p = simple_get_bytes(p, end, &timeout, sizeof(timeout));
 201	if (IS_ERR(p))
 202		goto err;
 203	if (timeout == 0)
 204		timeout = GSSD_MIN_TIMEOUT;
 205	ctx->gc_expiry = now + ((unsigned long)timeout * HZ);
 206	/* Sequence number window. Determines the maximum number of
 207	 * simultaneous requests
 208	 */
 209	p = simple_get_bytes(p, end, &window_size, sizeof(window_size));
 210	if (IS_ERR(p))
 211		goto err;
 212	ctx->gc_win = window_size;
 213	/* gssd signals an error by passing ctx->gc_win = 0: */
 214	if (ctx->gc_win == 0) {
 215		/*
 216		 * in which case, p points to an error code. Anything other
 217		 * than -EKEYEXPIRED gets converted to -EACCES.
 218		 */
 219		p = simple_get_bytes(p, end, &ret, sizeof(ret));
 220		if (!IS_ERR(p))
 221			p = (ret == -EKEYEXPIRED) ? ERR_PTR(-EKEYEXPIRED) :
 222						    ERR_PTR(-EACCES);
 223		goto err;
 224	}
 225	/* copy the opaque wire context */
 226	p = simple_get_netobj(p, end, &ctx->gc_wire_ctx);
 227	if (IS_ERR(p))
 228		goto err;
 229	/* import the opaque security context */
 230	p  = simple_get_bytes(p, end, &seclen, sizeof(seclen));
 231	if (IS_ERR(p))
 232		goto err;
 233	q = (const void *)((const char *)p + seclen);
 234	if (unlikely(q > end || q < p)) {
 235		p = ERR_PTR(-EFAULT);
 236		goto err;
 237	}
 238	ret = gss_import_sec_context(p, seclen, gm, &ctx->gc_gss_ctx, NULL, GFP_NOFS);
 239	if (ret < 0) {
 240		trace_rpcgss_import_ctx(ret);
 241		p = ERR_PTR(ret);
 242		goto err;
 243	}
 244
 245	/* is there any trailing data? */
 246	if (q == end) {
 247		p = q;
 248		goto done;
 249	}
 250
 251	/* pull in acceptor name (if there is one) */
 252	p = simple_get_netobj(q, end, &ctx->gc_acceptor);
 253	if (IS_ERR(p))
 254		goto err;
 255done:
 256	trace_rpcgss_context(ctx->gc_expiry, now, timeout,
 257			     ctx->gc_acceptor.len, ctx->gc_acceptor.data);
 258err:
 259	return p;
 260}
 261
 262/* XXX: Need some documentation about why UPCALL_BUF_LEN is so small.
 263 *	Is user space expecting no more than UPCALL_BUF_LEN bytes?
 264 *	Note that there are now _two_ NI_MAXHOST sized data items
 265 *	being passed in this string.
 266 */
 267#define UPCALL_BUF_LEN	256
 268
 269struct gss_upcall_msg {
 270	refcount_t count;
 271	kuid_t	uid;
 272	const char *service_name;
 273	struct rpc_pipe_msg msg;
 274	struct list_head list;
 275	struct gss_auth *auth;
 276	struct rpc_pipe *pipe;
 277	struct rpc_wait_queue rpc_waitqueue;
 278	wait_queue_head_t waitqueue;
 279	struct gss_cl_ctx *ctx;
 280	char databuf[UPCALL_BUF_LEN];
 281};
 282
 283static int get_pipe_version(struct net *net)
 284{
 285	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 286	int ret;
 287
 288	spin_lock(&pipe_version_lock);
 289	if (sn->pipe_version >= 0) {
 290		atomic_inc(&sn->pipe_users);
 291		ret = sn->pipe_version;
 292	} else
 293		ret = -EAGAIN;
 294	spin_unlock(&pipe_version_lock);
 295	return ret;
 296}
 297
 298static void put_pipe_version(struct net *net)
 299{
 300	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 301
 302	if (atomic_dec_and_lock(&sn->pipe_users, &pipe_version_lock)) {
 303		sn->pipe_version = -1;
 304		spin_unlock(&pipe_version_lock);
 305	}
 306}
 307
 308static void
 309gss_release_msg(struct gss_upcall_msg *gss_msg)
 310{
 311	struct net *net = gss_msg->auth->net;
 312	if (!refcount_dec_and_test(&gss_msg->count))
 313		return;
 314	put_pipe_version(net);
 315	BUG_ON(!list_empty(&gss_msg->list));
 316	if (gss_msg->ctx != NULL)
 317		gss_put_ctx(gss_msg->ctx);
 318	rpc_destroy_wait_queue(&gss_msg->rpc_waitqueue);
 319	gss_put_auth(gss_msg->auth);
 320	kfree_const(gss_msg->service_name);
 321	kfree(gss_msg);
 322}
 323
 324static struct gss_upcall_msg *
 325__gss_find_upcall(struct rpc_pipe *pipe, kuid_t uid, const struct gss_auth *auth)
 326{
 327	struct gss_upcall_msg *pos;
 328	list_for_each_entry(pos, &pipe->in_downcall, list) {
 329		if (!uid_eq(pos->uid, uid))
 330			continue;
 331		if (auth && pos->auth->service != auth->service)
 332			continue;
 333		refcount_inc(&pos->count);
 334		return pos;
 335	}
 336	return NULL;
 337}
 338
 339/* Try to add an upcall to the pipefs queue.
 340 * If an upcall owned by our uid already exists, then we return a reference
 341 * to that upcall instead of adding the new upcall.
 342 */
 343static inline struct gss_upcall_msg *
 344gss_add_msg(struct gss_upcall_msg *gss_msg)
 345{
 346	struct rpc_pipe *pipe = gss_msg->pipe;
 347	struct gss_upcall_msg *old;
 348
 349	spin_lock(&pipe->lock);
 350	old = __gss_find_upcall(pipe, gss_msg->uid, gss_msg->auth);
 351	if (old == NULL) {
 352		refcount_inc(&gss_msg->count);
 353		list_add(&gss_msg->list, &pipe->in_downcall);
 354	} else
 355		gss_msg = old;
 356	spin_unlock(&pipe->lock);
 357	return gss_msg;
 358}
 359
 360static void
 361__gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 362{
 363	list_del_init(&gss_msg->list);
 364	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 365	wake_up_all(&gss_msg->waitqueue);
 366	refcount_dec(&gss_msg->count);
 367}
 368
 369static void
 370gss_unhash_msg(struct gss_upcall_msg *gss_msg)
 371{
 372	struct rpc_pipe *pipe = gss_msg->pipe;
 373
 374	if (list_empty(&gss_msg->list))
 375		return;
 376	spin_lock(&pipe->lock);
 377	if (!list_empty(&gss_msg->list))
 378		__gss_unhash_msg(gss_msg);
 379	spin_unlock(&pipe->lock);
 380}
 381
 382static void
 383gss_handle_downcall_result(struct gss_cred *gss_cred, struct gss_upcall_msg *gss_msg)
 384{
 385	switch (gss_msg->msg.errno) {
 386	case 0:
 387		if (gss_msg->ctx == NULL)
 388			break;
 389		clear_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 390		gss_cred_set_ctx(&gss_cred->gc_base, gss_msg->ctx);
 391		break;
 392	case -EKEYEXPIRED:
 393		set_bit(RPCAUTH_CRED_NEGATIVE, &gss_cred->gc_base.cr_flags);
 394	}
 395	gss_cred->gc_upcall_timestamp = jiffies;
 396	gss_cred->gc_upcall = NULL;
 397	rpc_wake_up_status(&gss_msg->rpc_waitqueue, gss_msg->msg.errno);
 398}
 399
 400static void
 401gss_upcall_callback(struct rpc_task *task)
 402{
 403	struct gss_cred *gss_cred = container_of(task->tk_rqstp->rq_cred,
 404			struct gss_cred, gc_base);
 405	struct gss_upcall_msg *gss_msg = gss_cred->gc_upcall;
 406	struct rpc_pipe *pipe = gss_msg->pipe;
 407
 408	spin_lock(&pipe->lock);
 409	gss_handle_downcall_result(gss_cred, gss_msg);
 410	spin_unlock(&pipe->lock);
 411	task->tk_status = gss_msg->msg.errno;
 412	gss_release_msg(gss_msg);
 413}
 414
 415static void gss_encode_v0_msg(struct gss_upcall_msg *gss_msg,
 416			      const struct cred *cred)
 417{
 418	struct user_namespace *userns = cred->user_ns;
 419
 420	uid_t uid = from_kuid_munged(userns, gss_msg->uid);
 421	memcpy(gss_msg->databuf, &uid, sizeof(uid));
 422	gss_msg->msg.data = gss_msg->databuf;
 423	gss_msg->msg.len = sizeof(uid);
 424
 425	BUILD_BUG_ON(sizeof(uid) > sizeof(gss_msg->databuf));
 426}
 427
 428static ssize_t
 429gss_v0_upcall(struct file *file, struct rpc_pipe_msg *msg,
 430		char __user *buf, size_t buflen)
 431{
 432	struct gss_upcall_msg *gss_msg = container_of(msg,
 433						      struct gss_upcall_msg,
 434						      msg);
 435	if (msg->copied == 0)
 436		gss_encode_v0_msg(gss_msg, file->f_cred);
 437	return rpc_pipe_generic_upcall(file, msg, buf, buflen);
 438}
 439
 440static int gss_encode_v1_msg(struct gss_upcall_msg *gss_msg,
 441				const char *service_name,
 442				const char *target_name,
 443				const struct cred *cred)
 444{
 445	struct user_namespace *userns = cred->user_ns;
 446	struct gss_api_mech *mech = gss_msg->auth->mech;
 447	char *p = gss_msg->databuf;
 448	size_t buflen = sizeof(gss_msg->databuf);
 449	int len;
 450
 451	len = scnprintf(p, buflen, "mech=%s uid=%d", mech->gm_name,
 452			from_kuid_munged(userns, gss_msg->uid));
 453	buflen -= len;
 454	p += len;
 455	gss_msg->msg.len = len;
 456
 457	/*
 458	 * target= is a full service principal that names the remote
 459	 * identity that we are authenticating to.
 460	 */
 461	if (target_name) {
 462		len = scnprintf(p, buflen, " target=%s", target_name);
 463		buflen -= len;
 464		p += len;
 465		gss_msg->msg.len += len;
 466	}
 467
 468	/*
 469	 * gssd uses service= and srchost= to select a matching key from
 470	 * the system's keytab to use as the source principal.
 471	 *
 472	 * service= is the service name part of the source principal,
 473	 * or "*" (meaning choose any).
 474	 *
 475	 * srchost= is the hostname part of the source principal. When
 476	 * not provided, gssd uses the local hostname.
 477	 */
 478	if (service_name) {
 479		char *c = strchr(service_name, '@');
 480
 481		if (!c)
 482			len = scnprintf(p, buflen, " service=%s",
 483					service_name);
 484		else
 485			len = scnprintf(p, buflen,
 486					" service=%.*s srchost=%s",
 487					(int)(c - service_name),
 488					service_name, c + 1);
 489		buflen -= len;
 490		p += len;
 491		gss_msg->msg.len += len;
 492	}
 493
 494	if (mech->gm_upcall_enctypes) {
 495		len = scnprintf(p, buflen, " enctypes=%s",
 496				mech->gm_upcall_enctypes);
 497		buflen -= len;
 498		p += len;
 499		gss_msg->msg.len += len;
 500	}
 501	trace_rpcgss_upcall_msg(gss_msg->databuf);
 502	len = scnprintf(p, buflen, "\n");
 503	if (len == 0)
 504		goto out_overflow;
 505	gss_msg->msg.len += len;
 506	gss_msg->msg.data = gss_msg->databuf;
 507	return 0;
 508out_overflow:
 509	WARN_ON_ONCE(1);
 510	return -ENOMEM;
 511}
 512
 513static ssize_t
 514gss_v1_upcall(struct file *file, struct rpc_pipe_msg *msg,
 515		char __user *buf, size_t buflen)
 516{
 517	struct gss_upcall_msg *gss_msg = container_of(msg,
 518						      struct gss_upcall_msg,
 519						      msg);
 520	int err;
 521	if (msg->copied == 0) {
 522		err = gss_encode_v1_msg(gss_msg,
 523					gss_msg->service_name,
 524					gss_msg->auth->target_name,
 525					file->f_cred);
 526		if (err)
 527			return err;
 528	}
 529	return rpc_pipe_generic_upcall(file, msg, buf, buflen);
 530}
 531
 532static struct gss_upcall_msg *
 533gss_alloc_msg(struct gss_auth *gss_auth,
 534		kuid_t uid, const char *service_name)
 535{
 536	struct gss_upcall_msg *gss_msg;
 537	int vers;
 538	int err = -ENOMEM;
 539
 540	gss_msg = kzalloc(sizeof(*gss_msg), GFP_NOFS);
 541	if (gss_msg == NULL)
 542		goto err;
 543	vers = get_pipe_version(gss_auth->net);
 544	err = vers;
 545	if (err < 0)
 546		goto err_free_msg;
 547	gss_msg->pipe = gss_auth->gss_pipe[vers]->pipe;
 548	INIT_LIST_HEAD(&gss_msg->list);
 549	rpc_init_wait_queue(&gss_msg->rpc_waitqueue, "RPCSEC_GSS upcall waitq");
 550	init_waitqueue_head(&gss_msg->waitqueue);
 551	refcount_set(&gss_msg->count, 1);
 552	gss_msg->uid = uid;
 553	gss_msg->auth = gss_auth;
 554	kref_get(&gss_auth->kref);
 555	if (service_name) {
 556		gss_msg->service_name = kstrdup_const(service_name, GFP_NOFS);
 557		if (!gss_msg->service_name) {
 558			err = -ENOMEM;
 559			goto err_put_pipe_version;
 560		}
 561	}
 562	return gss_msg;
 563err_put_pipe_version:
 564	put_pipe_version(gss_auth->net);
 565err_free_msg:
 566	kfree(gss_msg);
 567err:
 568	return ERR_PTR(err);
 569}
 570
 571static struct gss_upcall_msg *
 572gss_setup_upcall(struct gss_auth *gss_auth, struct rpc_cred *cred)
 573{
 574	struct gss_cred *gss_cred = container_of(cred,
 575			struct gss_cred, gc_base);
 576	struct gss_upcall_msg *gss_new, *gss_msg;
 577	kuid_t uid = cred->cr_cred->fsuid;
 578
 579	gss_new = gss_alloc_msg(gss_auth, uid, gss_cred->gc_principal);
 580	if (IS_ERR(gss_new))
 581		return gss_new;
 582	gss_msg = gss_add_msg(gss_new);
 583	if (gss_msg == gss_new) {
 584		int res;
 585		refcount_inc(&gss_msg->count);
 586		res = rpc_queue_upcall(gss_new->pipe, &gss_new->msg);
 587		if (res) {
 588			gss_unhash_msg(gss_new);
 589			refcount_dec(&gss_msg->count);
 590			gss_release_msg(gss_new);
 591			gss_msg = ERR_PTR(res);
 592		}
 593	} else
 594		gss_release_msg(gss_new);
 595	return gss_msg;
 596}
 597
 598static void warn_gssd(void)
 599{
 600	dprintk("AUTH_GSS upcall failed. Please check user daemon is running.\n");
 601}
 602
 603static inline int
 604gss_refresh_upcall(struct rpc_task *task)
 605{
 606	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
 607	struct gss_auth *gss_auth = container_of(cred->cr_auth,
 608			struct gss_auth, rpc_auth);
 609	struct gss_cred *gss_cred = container_of(cred,
 610			struct gss_cred, gc_base);
 611	struct gss_upcall_msg *gss_msg;
 612	struct rpc_pipe *pipe;
 613	int err = 0;
 614
 615	gss_msg = gss_setup_upcall(gss_auth, cred);
 616	if (PTR_ERR(gss_msg) == -EAGAIN) {
 617		/* XXX: warning on the first, under the assumption we
 618		 * shouldn't normally hit this case on a refresh. */
 619		warn_gssd();
 620		rpc_sleep_on_timeout(&pipe_version_rpc_waitqueue,
 621				task, NULL, jiffies + (15 * HZ));
 622		err = -EAGAIN;
 623		goto out;
 624	}
 625	if (IS_ERR(gss_msg)) {
 626		err = PTR_ERR(gss_msg);
 627		goto out;
 628	}
 629	pipe = gss_msg->pipe;
 630	spin_lock(&pipe->lock);
 631	if (gss_cred->gc_upcall != NULL)
 632		rpc_sleep_on(&gss_cred->gc_upcall->rpc_waitqueue, task, NULL);
 633	else if (gss_msg->ctx == NULL && gss_msg->msg.errno >= 0) {
 634		gss_cred->gc_upcall = gss_msg;
 635		/* gss_upcall_callback will release the reference to gss_upcall_msg */
 636		refcount_inc(&gss_msg->count);
 637		rpc_sleep_on(&gss_msg->rpc_waitqueue, task, gss_upcall_callback);
 638	} else {
 639		gss_handle_downcall_result(gss_cred, gss_msg);
 640		err = gss_msg->msg.errno;
 641	}
 642	spin_unlock(&pipe->lock);
 643	gss_release_msg(gss_msg);
 644out:
 645	trace_rpcgss_upcall_result(from_kuid(&init_user_ns,
 646					     cred->cr_cred->fsuid), err);
 647	return err;
 648}
 649
 650static inline int
 651gss_create_upcall(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
 652{
 653	struct net *net = gss_auth->net;
 654	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 655	struct rpc_pipe *pipe;
 656	struct rpc_cred *cred = &gss_cred->gc_base;
 657	struct gss_upcall_msg *gss_msg;
 658	DEFINE_WAIT(wait);
 659	int err;
 660
 661retry:
 662	err = 0;
 663	/* if gssd is down, just skip upcalling altogether */
 664	if (!gssd_running(net)) {
 665		warn_gssd();
 666		err = -EACCES;
 667		goto out;
 668	}
 669	gss_msg = gss_setup_upcall(gss_auth, cred);
 670	if (PTR_ERR(gss_msg) == -EAGAIN) {
 671		err = wait_event_interruptible_timeout(pipe_version_waitqueue,
 672				sn->pipe_version >= 0, 15 * HZ);
 673		if (sn->pipe_version < 0) {
 674			warn_gssd();
 675			err = -EACCES;
 676		}
 677		if (err < 0)
 678			goto out;
 679		goto retry;
 680	}
 681	if (IS_ERR(gss_msg)) {
 682		err = PTR_ERR(gss_msg);
 683		goto out;
 684	}
 685	pipe = gss_msg->pipe;
 686	for (;;) {
 687		prepare_to_wait(&gss_msg->waitqueue, &wait, TASK_KILLABLE);
 688		spin_lock(&pipe->lock);
 689		if (gss_msg->ctx != NULL || gss_msg->msg.errno < 0) {
 690			break;
 691		}
 692		spin_unlock(&pipe->lock);
 693		if (fatal_signal_pending(current)) {
 694			err = -ERESTARTSYS;
 695			goto out_intr;
 696		}
 697		schedule();
 698	}
 699	if (gss_msg->ctx)
 
 700		gss_cred_set_ctx(cred, gss_msg->ctx);
 701	else
 702		err = gss_msg->msg.errno;
 
 703	spin_unlock(&pipe->lock);
 704out_intr:
 705	finish_wait(&gss_msg->waitqueue, &wait);
 706	gss_release_msg(gss_msg);
 707out:
 708	trace_rpcgss_upcall_result(from_kuid(&init_user_ns,
 709					     cred->cr_cred->fsuid), err);
 710	return err;
 711}
 712
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 713#define MSG_BUF_MAXSIZE 1024
 714
 715static ssize_t
 716gss_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 717{
 718	const void *p, *end;
 719	void *buf;
 720	struct gss_upcall_msg *gss_msg;
 721	struct rpc_pipe *pipe = RPC_I(file_inode(filp))->pipe;
 722	struct gss_cl_ctx *ctx;
 723	uid_t id;
 724	kuid_t uid;
 725	ssize_t err = -EFBIG;
 726
 727	if (mlen > MSG_BUF_MAXSIZE)
 728		goto out;
 729	err = -ENOMEM;
 730	buf = kmalloc(mlen, GFP_NOFS);
 731	if (!buf)
 732		goto out;
 733
 734	err = -EFAULT;
 735	if (copy_from_user(buf, src, mlen))
 736		goto err;
 737
 738	end = (const void *)((char *)buf + mlen);
 739	p = simple_get_bytes(buf, end, &id, sizeof(id));
 740	if (IS_ERR(p)) {
 741		err = PTR_ERR(p);
 742		goto err;
 743	}
 744
 745	uid = make_kuid(current_user_ns(), id);
 746	if (!uid_valid(uid)) {
 747		err = -EINVAL;
 748		goto err;
 749	}
 750
 751	err = -ENOMEM;
 752	ctx = gss_alloc_context();
 753	if (ctx == NULL)
 754		goto err;
 755
 756	err = -ENOENT;
 757	/* Find a matching upcall */
 758	spin_lock(&pipe->lock);
 759	gss_msg = __gss_find_upcall(pipe, uid, NULL);
 760	if (gss_msg == NULL) {
 761		spin_unlock(&pipe->lock);
 762		goto err_put_ctx;
 763	}
 764	list_del_init(&gss_msg->list);
 765	spin_unlock(&pipe->lock);
 766
 767	p = gss_fill_context(p, end, ctx, gss_msg->auth->mech);
 768	if (IS_ERR(p)) {
 769		err = PTR_ERR(p);
 770		switch (err) {
 771		case -EACCES:
 772		case -EKEYEXPIRED:
 773			gss_msg->msg.errno = err;
 774			err = mlen;
 775			break;
 776		case -EFAULT:
 777		case -ENOMEM:
 778		case -EINVAL:
 779		case -ENOSYS:
 780			gss_msg->msg.errno = -EAGAIN;
 781			break;
 782		default:
 783			printk(KERN_CRIT "%s: bad return from "
 784				"gss_fill_context: %zd\n", __func__, err);
 785			gss_msg->msg.errno = -EIO;
 786		}
 787		goto err_release_msg;
 788	}
 789	gss_msg->ctx = gss_get_ctx(ctx);
 790	err = mlen;
 791
 792err_release_msg:
 793	spin_lock(&pipe->lock);
 794	__gss_unhash_msg(gss_msg);
 795	spin_unlock(&pipe->lock);
 796	gss_release_msg(gss_msg);
 797err_put_ctx:
 798	gss_put_ctx(ctx);
 799err:
 800	kfree(buf);
 801out:
 802	return err;
 803}
 804
 805static int gss_pipe_open(struct inode *inode, int new_version)
 806{
 807	struct net *net = inode->i_sb->s_fs_info;
 808	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 809	int ret = 0;
 810
 811	spin_lock(&pipe_version_lock);
 812	if (sn->pipe_version < 0) {
 813		/* First open of any gss pipe determines the version: */
 814		sn->pipe_version = new_version;
 815		rpc_wake_up(&pipe_version_rpc_waitqueue);
 816		wake_up(&pipe_version_waitqueue);
 817	} else if (sn->pipe_version != new_version) {
 818		/* Trying to open a pipe of a different version */
 819		ret = -EBUSY;
 820		goto out;
 821	}
 822	atomic_inc(&sn->pipe_users);
 823out:
 824	spin_unlock(&pipe_version_lock);
 825	return ret;
 826
 827}
 828
 829static int gss_pipe_open_v0(struct inode *inode)
 830{
 831	return gss_pipe_open(inode, 0);
 832}
 833
 834static int gss_pipe_open_v1(struct inode *inode)
 835{
 836	return gss_pipe_open(inode, 1);
 837}
 838
 839static void
 840gss_pipe_release(struct inode *inode)
 841{
 842	struct net *net = inode->i_sb->s_fs_info;
 843	struct rpc_pipe *pipe = RPC_I(inode)->pipe;
 844	struct gss_upcall_msg *gss_msg;
 845
 846restart:
 847	spin_lock(&pipe->lock);
 848	list_for_each_entry(gss_msg, &pipe->in_downcall, list) {
 849
 850		if (!list_empty(&gss_msg->msg.list))
 851			continue;
 852		gss_msg->msg.errno = -EPIPE;
 853		refcount_inc(&gss_msg->count);
 854		__gss_unhash_msg(gss_msg);
 855		spin_unlock(&pipe->lock);
 856		gss_release_msg(gss_msg);
 857		goto restart;
 858	}
 859	spin_unlock(&pipe->lock);
 860
 861	put_pipe_version(net);
 862}
 863
 864static void
 865gss_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 866{
 867	struct gss_upcall_msg *gss_msg = container_of(msg, struct gss_upcall_msg, msg);
 868
 869	if (msg->errno < 0) {
 870		refcount_inc(&gss_msg->count);
 871		gss_unhash_msg(gss_msg);
 872		if (msg->errno == -ETIMEDOUT)
 873			warn_gssd();
 874		gss_release_msg(gss_msg);
 875	}
 876	gss_release_msg(gss_msg);
 877}
 878
 879static void gss_pipe_dentry_destroy(struct dentry *dir,
 880		struct rpc_pipe_dir_object *pdo)
 881{
 882	struct gss_pipe *gss_pipe = pdo->pdo_data;
 883	struct rpc_pipe *pipe = gss_pipe->pipe;
 884
 885	if (pipe->dentry != NULL) {
 886		rpc_unlink(pipe->dentry);
 887		pipe->dentry = NULL;
 888	}
 889}
 890
 891static int gss_pipe_dentry_create(struct dentry *dir,
 892		struct rpc_pipe_dir_object *pdo)
 893{
 894	struct gss_pipe *p = pdo->pdo_data;
 895	struct dentry *dentry;
 896
 897	dentry = rpc_mkpipe_dentry(dir, p->name, p->clnt, p->pipe);
 898	if (IS_ERR(dentry))
 899		return PTR_ERR(dentry);
 900	p->pipe->dentry = dentry;
 901	return 0;
 902}
 903
 904static const struct rpc_pipe_dir_object_ops gss_pipe_dir_object_ops = {
 905	.create = gss_pipe_dentry_create,
 906	.destroy = gss_pipe_dentry_destroy,
 907};
 908
 909static struct gss_pipe *gss_pipe_alloc(struct rpc_clnt *clnt,
 910		const char *name,
 911		const struct rpc_pipe_ops *upcall_ops)
 912{
 913	struct gss_pipe *p;
 914	int err = -ENOMEM;
 915
 916	p = kmalloc(sizeof(*p), GFP_KERNEL);
 917	if (p == NULL)
 918		goto err;
 919	p->pipe = rpc_mkpipe_data(upcall_ops, RPC_PIPE_WAIT_FOR_OPEN);
 920	if (IS_ERR(p->pipe)) {
 921		err = PTR_ERR(p->pipe);
 922		goto err_free_gss_pipe;
 923	}
 924	p->name = name;
 925	p->clnt = clnt;
 926	kref_init(&p->kref);
 927	rpc_init_pipe_dir_object(&p->pdo,
 928			&gss_pipe_dir_object_ops,
 929			p);
 930	return p;
 931err_free_gss_pipe:
 932	kfree(p);
 933err:
 934	return ERR_PTR(err);
 935}
 936
 937struct gss_alloc_pdo {
 938	struct rpc_clnt *clnt;
 939	const char *name;
 940	const struct rpc_pipe_ops *upcall_ops;
 941};
 942
 943static int gss_pipe_match_pdo(struct rpc_pipe_dir_object *pdo, void *data)
 944{
 945	struct gss_pipe *gss_pipe;
 946	struct gss_alloc_pdo *args = data;
 947
 948	if (pdo->pdo_ops != &gss_pipe_dir_object_ops)
 949		return 0;
 950	gss_pipe = container_of(pdo, struct gss_pipe, pdo);
 951	if (strcmp(gss_pipe->name, args->name) != 0)
 952		return 0;
 953	if (!kref_get_unless_zero(&gss_pipe->kref))
 954		return 0;
 955	return 1;
 956}
 957
 958static struct rpc_pipe_dir_object *gss_pipe_alloc_pdo(void *data)
 959{
 960	struct gss_pipe *gss_pipe;
 961	struct gss_alloc_pdo *args = data;
 962
 963	gss_pipe = gss_pipe_alloc(args->clnt, args->name, args->upcall_ops);
 964	if (!IS_ERR(gss_pipe))
 965		return &gss_pipe->pdo;
 966	return NULL;
 967}
 968
 969static struct gss_pipe *gss_pipe_get(struct rpc_clnt *clnt,
 970		const char *name,
 971		const struct rpc_pipe_ops *upcall_ops)
 972{
 973	struct net *net = rpc_net_ns(clnt);
 974	struct rpc_pipe_dir_object *pdo;
 975	struct gss_alloc_pdo args = {
 976		.clnt = clnt,
 977		.name = name,
 978		.upcall_ops = upcall_ops,
 979	};
 980
 981	pdo = rpc_find_or_alloc_pipe_dir_object(net,
 982			&clnt->cl_pipedir_objects,
 983			gss_pipe_match_pdo,
 984			gss_pipe_alloc_pdo,
 985			&args);
 986	if (pdo != NULL)
 987		return container_of(pdo, struct gss_pipe, pdo);
 988	return ERR_PTR(-ENOMEM);
 989}
 990
 991static void __gss_pipe_free(struct gss_pipe *p)
 992{
 993	struct rpc_clnt *clnt = p->clnt;
 994	struct net *net = rpc_net_ns(clnt);
 995
 996	rpc_remove_pipe_dir_object(net,
 997			&clnt->cl_pipedir_objects,
 998			&p->pdo);
 999	rpc_destroy_pipe_data(p->pipe);
1000	kfree(p);
1001}
1002
1003static void __gss_pipe_release(struct kref *kref)
1004{
1005	struct gss_pipe *p = container_of(kref, struct gss_pipe, kref);
1006
1007	__gss_pipe_free(p);
1008}
1009
1010static void gss_pipe_free(struct gss_pipe *p)
1011{
1012	if (p != NULL)
1013		kref_put(&p->kref, __gss_pipe_release);
1014}
1015
1016/*
1017 * NOTE: we have the opportunity to use different
1018 * parameters based on the input flavor (which must be a pseudoflavor)
1019 */
1020static struct gss_auth *
1021gss_create_new(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1022{
1023	rpc_authflavor_t flavor = args->pseudoflavor;
1024	struct gss_auth *gss_auth;
1025	struct gss_pipe *gss_pipe;
1026	struct rpc_auth * auth;
1027	int err = -ENOMEM; /* XXX? */
1028
1029	if (!try_module_get(THIS_MODULE))
1030		return ERR_PTR(err);
1031	if (!(gss_auth = kmalloc(sizeof(*gss_auth), GFP_KERNEL)))
1032		goto out_dec;
1033	INIT_HLIST_NODE(&gss_auth->hash);
1034	gss_auth->target_name = NULL;
1035	if (args->target_name) {
1036		gss_auth->target_name = kstrdup(args->target_name, GFP_KERNEL);
1037		if (gss_auth->target_name == NULL)
1038			goto err_free;
1039	}
1040	gss_auth->client = clnt;
1041	gss_auth->net = get_net(rpc_net_ns(clnt));
 
1042	err = -EINVAL;
1043	gss_auth->mech = gss_mech_get_by_pseudoflavor(flavor);
1044	if (!gss_auth->mech)
1045		goto err_put_net;
1046	gss_auth->service = gss_pseudoflavor_to_service(gss_auth->mech, flavor);
1047	if (gss_auth->service == 0)
1048		goto err_put_mech;
1049	if (!gssd_running(gss_auth->net))
1050		goto err_put_mech;
1051	auth = &gss_auth->rpc_auth;
1052	auth->au_cslack = GSS_CRED_SLACK >> 2;
1053	auth->au_rslack = GSS_VERF_SLACK >> 2;
1054	auth->au_verfsize = GSS_VERF_SLACK >> 2;
1055	auth->au_ralign = GSS_VERF_SLACK >> 2;
1056	auth->au_flags = 0;
1057	auth->au_ops = &authgss_ops;
1058	auth->au_flavor = flavor;
1059	if (gss_pseudoflavor_to_datatouch(gss_auth->mech, flavor))
1060		auth->au_flags |= RPCAUTH_AUTH_DATATOUCH;
1061	refcount_set(&auth->au_count, 1);
1062	kref_init(&gss_auth->kref);
1063
1064	err = rpcauth_init_credcache(auth);
1065	if (err)
1066		goto err_put_mech;
1067	/*
1068	 * Note: if we created the old pipe first, then someone who
1069	 * examined the directory at the right moment might conclude
1070	 * that we supported only the old pipe.  So we instead create
1071	 * the new pipe first.
1072	 */
1073	gss_pipe = gss_pipe_get(clnt, "gssd", &gss_upcall_ops_v1);
1074	if (IS_ERR(gss_pipe)) {
1075		err = PTR_ERR(gss_pipe);
1076		goto err_destroy_credcache;
1077	}
1078	gss_auth->gss_pipe[1] = gss_pipe;
1079
1080	gss_pipe = gss_pipe_get(clnt, gss_auth->mech->gm_name,
1081			&gss_upcall_ops_v0);
1082	if (IS_ERR(gss_pipe)) {
1083		err = PTR_ERR(gss_pipe);
1084		goto err_destroy_pipe_1;
1085	}
1086	gss_auth->gss_pipe[0] = gss_pipe;
1087
1088	return gss_auth;
1089err_destroy_pipe_1:
1090	gss_pipe_free(gss_auth->gss_pipe[1]);
1091err_destroy_credcache:
1092	rpcauth_destroy_credcache(auth);
1093err_put_mech:
1094	gss_mech_put(gss_auth->mech);
1095err_put_net:
1096	put_net(gss_auth->net);
1097err_free:
1098	kfree(gss_auth->target_name);
1099	kfree(gss_auth);
1100out_dec:
1101	module_put(THIS_MODULE);
1102	trace_rpcgss_createauth(flavor, err);
1103	return ERR_PTR(err);
1104}
1105
1106static void
1107gss_free(struct gss_auth *gss_auth)
1108{
1109	gss_pipe_free(gss_auth->gss_pipe[0]);
1110	gss_pipe_free(gss_auth->gss_pipe[1]);
1111	gss_mech_put(gss_auth->mech);
1112	put_net(gss_auth->net);
1113	kfree(gss_auth->target_name);
1114
1115	kfree(gss_auth);
1116	module_put(THIS_MODULE);
1117}
1118
1119static void
1120gss_free_callback(struct kref *kref)
1121{
1122	struct gss_auth *gss_auth = container_of(kref, struct gss_auth, kref);
1123
1124	gss_free(gss_auth);
1125}
1126
1127static void
1128gss_put_auth(struct gss_auth *gss_auth)
1129{
1130	kref_put(&gss_auth->kref, gss_free_callback);
1131}
1132
1133static void
1134gss_destroy(struct rpc_auth *auth)
1135{
1136	struct gss_auth *gss_auth = container_of(auth,
1137			struct gss_auth, rpc_auth);
1138
1139	if (hash_hashed(&gss_auth->hash)) {
1140		spin_lock(&gss_auth_hash_lock);
1141		hash_del(&gss_auth->hash);
1142		spin_unlock(&gss_auth_hash_lock);
1143	}
1144
1145	gss_pipe_free(gss_auth->gss_pipe[0]);
1146	gss_auth->gss_pipe[0] = NULL;
1147	gss_pipe_free(gss_auth->gss_pipe[1]);
1148	gss_auth->gss_pipe[1] = NULL;
1149	rpcauth_destroy_credcache(auth);
1150
1151	gss_put_auth(gss_auth);
1152}
1153
1154/*
1155 * Auths may be shared between rpc clients that were cloned from a
1156 * common client with the same xprt, if they also share the flavor and
1157 * target_name.
1158 *
1159 * The auth is looked up from the oldest parent sharing the same
1160 * cl_xprt, and the auth itself references only that common parent
1161 * (which is guaranteed to last as long as any of its descendants).
1162 */
1163static struct gss_auth *
1164gss_auth_find_or_add_hashed(const struct rpc_auth_create_args *args,
1165		struct rpc_clnt *clnt,
1166		struct gss_auth *new)
1167{
1168	struct gss_auth *gss_auth;
1169	unsigned long hashval = (unsigned long)clnt;
1170
1171	spin_lock(&gss_auth_hash_lock);
1172	hash_for_each_possible(gss_auth_hash_table,
1173			gss_auth,
1174			hash,
1175			hashval) {
1176		if (gss_auth->client != clnt)
1177			continue;
1178		if (gss_auth->rpc_auth.au_flavor != args->pseudoflavor)
1179			continue;
1180		if (gss_auth->target_name != args->target_name) {
1181			if (gss_auth->target_name == NULL)
1182				continue;
1183			if (args->target_name == NULL)
1184				continue;
1185			if (strcmp(gss_auth->target_name, args->target_name))
1186				continue;
1187		}
1188		if (!refcount_inc_not_zero(&gss_auth->rpc_auth.au_count))
1189			continue;
1190		goto out;
1191	}
1192	if (new)
1193		hash_add(gss_auth_hash_table, &new->hash, hashval);
1194	gss_auth = new;
1195out:
1196	spin_unlock(&gss_auth_hash_lock);
1197	return gss_auth;
1198}
1199
1200static struct gss_auth *
1201gss_create_hashed(const struct rpc_auth_create_args *args,
1202		  struct rpc_clnt *clnt)
1203{
1204	struct gss_auth *gss_auth;
1205	struct gss_auth *new;
1206
1207	gss_auth = gss_auth_find_or_add_hashed(args, clnt, NULL);
1208	if (gss_auth != NULL)
1209		goto out;
1210	new = gss_create_new(args, clnt);
1211	if (IS_ERR(new))
1212		return new;
1213	gss_auth = gss_auth_find_or_add_hashed(args, clnt, new);
1214	if (gss_auth != new)
1215		gss_destroy(&new->rpc_auth);
1216out:
1217	return gss_auth;
1218}
1219
1220static struct rpc_auth *
1221gss_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
1222{
1223	struct gss_auth *gss_auth;
1224	struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
1225
1226	while (clnt != clnt->cl_parent) {
1227		struct rpc_clnt *parent = clnt->cl_parent;
1228		/* Find the original parent for this transport */
1229		if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
1230			break;
1231		clnt = parent;
1232	}
1233
1234	gss_auth = gss_create_hashed(args, clnt);
1235	if (IS_ERR(gss_auth))
1236		return ERR_CAST(gss_auth);
1237	return &gss_auth->rpc_auth;
1238}
1239
1240static struct gss_cred *
1241gss_dup_cred(struct gss_auth *gss_auth, struct gss_cred *gss_cred)
1242{
1243	struct gss_cred *new;
1244
1245	/* Make a copy of the cred so that we can reference count it */
1246	new = kzalloc(sizeof(*gss_cred), GFP_NOFS);
1247	if (new) {
1248		struct auth_cred acred = {
1249			.cred = gss_cred->gc_base.cr_cred,
1250		};
1251		struct gss_cl_ctx *ctx =
1252			rcu_dereference_protected(gss_cred->gc_ctx, 1);
1253
1254		rpcauth_init_cred(&new->gc_base, &acred,
1255				&gss_auth->rpc_auth,
1256				&gss_nullops);
1257		new->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
1258		new->gc_service = gss_cred->gc_service;
1259		new->gc_principal = gss_cred->gc_principal;
1260		kref_get(&gss_auth->kref);
1261		rcu_assign_pointer(new->gc_ctx, ctx);
1262		gss_get_ctx(ctx);
1263	}
1264	return new;
1265}
1266
1267/*
1268 * gss_send_destroy_context will cause the RPCSEC_GSS to send a NULL RPC call
1269 * to the server with the GSS control procedure field set to
1270 * RPC_GSS_PROC_DESTROY. This should normally cause the server to release
1271 * all RPCSEC_GSS state associated with that context.
1272 */
1273static void
1274gss_send_destroy_context(struct rpc_cred *cred)
1275{
1276	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1277	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1278	struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1279	struct gss_cred *new;
1280	struct rpc_task *task;
1281
1282	new = gss_dup_cred(gss_auth, gss_cred);
1283	if (new) {
1284		ctx->gc_proc = RPC_GSS_PROC_DESTROY;
1285
 
1286		task = rpc_call_null(gss_auth->client, &new->gc_base,
1287				RPC_TASK_ASYNC|RPC_TASK_SOFT);
1288		if (!IS_ERR(task))
1289			rpc_put_task(task);
1290
1291		put_rpccred(&new->gc_base);
1292	}
1293}
1294
1295/* gss_destroy_cred (and gss_free_ctx) are used to clean up after failure
1296 * to create a new cred or context, so they check that things have been
1297 * allocated before freeing them. */
1298static void
1299gss_do_free_ctx(struct gss_cl_ctx *ctx)
1300{
1301	gss_delete_sec_context(&ctx->gc_gss_ctx);
1302	kfree(ctx->gc_wire_ctx.data);
1303	kfree(ctx->gc_acceptor.data);
1304	kfree(ctx);
1305}
1306
1307static void
1308gss_free_ctx_callback(struct rcu_head *head)
1309{
1310	struct gss_cl_ctx *ctx = container_of(head, struct gss_cl_ctx, gc_rcu);
1311	gss_do_free_ctx(ctx);
1312}
1313
1314static void
1315gss_free_ctx(struct gss_cl_ctx *ctx)
1316{
1317	call_rcu(&ctx->gc_rcu, gss_free_ctx_callback);
1318}
1319
1320static void
1321gss_free_cred(struct gss_cred *gss_cred)
1322{
1323	kfree(gss_cred);
1324}
1325
1326static void
1327gss_free_cred_callback(struct rcu_head *head)
1328{
1329	struct gss_cred *gss_cred = container_of(head, struct gss_cred, gc_base.cr_rcu);
1330	gss_free_cred(gss_cred);
1331}
1332
1333static void
1334gss_destroy_nullcred(struct rpc_cred *cred)
1335{
1336	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1337	struct gss_auth *gss_auth = container_of(cred->cr_auth, struct gss_auth, rpc_auth);
1338	struct gss_cl_ctx *ctx = rcu_dereference_protected(gss_cred->gc_ctx, 1);
1339
1340	RCU_INIT_POINTER(gss_cred->gc_ctx, NULL);
1341	put_cred(cred->cr_cred);
1342	call_rcu(&cred->cr_rcu, gss_free_cred_callback);
1343	if (ctx)
1344		gss_put_ctx(ctx);
1345	gss_put_auth(gss_auth);
1346}
1347
1348static void
1349gss_destroy_cred(struct rpc_cred *cred)
1350{
1351
1352	if (test_and_clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags) != 0)
1353		gss_send_destroy_context(cred);
1354	gss_destroy_nullcred(cred);
1355}
1356
1357static int
1358gss_hash_cred(struct auth_cred *acred, unsigned int hashbits)
1359{
1360	return hash_64(from_kuid(&init_user_ns, acred->cred->fsuid), hashbits);
1361}
1362
1363/*
1364 * Lookup RPCSEC_GSS cred for the current process
1365 */
1366static struct rpc_cred *
1367gss_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
1368{
1369	return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
 
1370}
1371
1372static struct rpc_cred *
1373gss_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
1374{
1375	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1376	struct gss_cred	*cred = NULL;
1377	int err = -ENOMEM;
1378
1379	if (!(cred = kzalloc(sizeof(*cred), gfp)))
1380		goto out_err;
1381
1382	rpcauth_init_cred(&cred->gc_base, acred, auth, &gss_credops);
1383	/*
1384	 * Note: in order to force a call to call_refresh(), we deliberately
1385	 * fail to flag the credential as RPCAUTH_CRED_UPTODATE.
1386	 */
1387	cred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_NEW;
1388	cred->gc_service = gss_auth->service;
1389	cred->gc_principal = acred->principal;
1390	kref_get(&gss_auth->kref);
1391	return &cred->gc_base;
1392
1393out_err:
1394	return ERR_PTR(err);
1395}
1396
1397static int
1398gss_cred_init(struct rpc_auth *auth, struct rpc_cred *cred)
1399{
1400	struct gss_auth *gss_auth = container_of(auth, struct gss_auth, rpc_auth);
1401	struct gss_cred *gss_cred = container_of(cred,struct gss_cred, gc_base);
1402	int err;
1403
1404	do {
1405		err = gss_create_upcall(gss_auth, gss_cred);
1406	} while (err == -EAGAIN);
1407	return err;
1408}
1409
1410static char *
1411gss_stringify_acceptor(struct rpc_cred *cred)
1412{
1413	char *string = NULL;
1414	struct gss_cred *gss_cred = container_of(cred, struct gss_cred, gc_base);
1415	struct gss_cl_ctx *ctx;
1416	unsigned int len;
1417	struct xdr_netobj *acceptor;
1418
1419	rcu_read_lock();
1420	ctx = rcu_dereference(gss_cred->gc_ctx);
1421	if (!ctx)
1422		goto out;
1423
1424	len = ctx->gc_acceptor.len;
1425	rcu_read_unlock();
1426
1427	/* no point if there's no string */
1428	if (!len)
1429		return NULL;
1430realloc:
1431	string = kmalloc(len + 1, GFP_KERNEL);
1432	if (!string)
1433		return NULL;
1434
1435	rcu_read_lock();
1436	ctx = rcu_dereference(gss_cred->gc_ctx);
1437
1438	/* did the ctx disappear or was it replaced by one with no acceptor? */
1439	if (!ctx || !ctx->gc_acceptor.len) {
1440		kfree(string);
1441		string = NULL;
1442		goto out;
1443	}
1444
1445	acceptor = &ctx->gc_acceptor;
1446
1447	/*
1448	 * Did we find a new acceptor that's longer than the original? Allocate
1449	 * a longer buffer and try again.
1450	 */
1451	if (len < acceptor->len) {
1452		len = acceptor->len;
1453		rcu_read_unlock();
1454		kfree(string);
1455		goto realloc;
1456	}
1457
1458	memcpy(string, acceptor->data, acceptor->len);
1459	string[acceptor->len] = '\0';
1460out:
1461	rcu_read_unlock();
1462	return string;
1463}
1464
1465/*
1466 * Returns -EACCES if GSS context is NULL or will expire within the
1467 * timeout (miliseconds)
1468 */
1469static int
1470gss_key_timeout(struct rpc_cred *rc)
1471{
1472	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1473	struct gss_cl_ctx *ctx;
1474	unsigned long timeout = jiffies + (gss_key_expire_timeo * HZ);
1475	int ret = 0;
1476
1477	rcu_read_lock();
1478	ctx = rcu_dereference(gss_cred->gc_ctx);
1479	if (!ctx || time_after(timeout, ctx->gc_expiry))
1480		ret = -EACCES;
1481	rcu_read_unlock();
1482
1483	return ret;
1484}
1485
1486static int
1487gss_match(struct auth_cred *acred, struct rpc_cred *rc, int flags)
1488{
1489	struct gss_cred *gss_cred = container_of(rc, struct gss_cred, gc_base);
1490	struct gss_cl_ctx *ctx;
1491	int ret;
1492
1493	if (test_bit(RPCAUTH_CRED_NEW, &rc->cr_flags))
1494		goto out;
1495	/* Don't match with creds that have expired. */
1496	rcu_read_lock();
1497	ctx = rcu_dereference(gss_cred->gc_ctx);
1498	if (!ctx || time_after(jiffies, ctx->gc_expiry)) {
1499		rcu_read_unlock();
1500		return 0;
1501	}
1502	rcu_read_unlock();
1503	if (!test_bit(RPCAUTH_CRED_UPTODATE, &rc->cr_flags))
1504		return 0;
1505out:
1506	if (acred->principal != NULL) {
1507		if (gss_cred->gc_principal == NULL)
1508			return 0;
1509		ret = strcmp(acred->principal, gss_cred->gc_principal) == 0;
1510	} else {
1511		if (gss_cred->gc_principal != NULL)
1512			return 0;
1513		ret = uid_eq(rc->cr_cred->fsuid, acred->cred->fsuid);
1514	}
1515	return ret;
1516}
1517
1518/*
1519 * Marshal credentials.
1520 *
1521 * The expensive part is computing the verifier. We can't cache a
1522 * pre-computed version of the verifier because the seqno, which
1523 * is different every time, is included in the MIC.
1524 */
1525static int gss_marshal(struct rpc_task *task, struct xdr_stream *xdr)
1526{
1527	struct rpc_rqst *req = task->tk_rqstp;
1528	struct rpc_cred *cred = req->rq_cred;
1529	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
1530						 gc_base);
1531	struct gss_cl_ctx	*ctx = gss_cred_get_ctx(cred);
1532	__be32		*p, *cred_len;
1533	u32             maj_stat = 0;
1534	struct xdr_netobj mic;
1535	struct kvec	iov;
1536	struct xdr_buf	verf_buf;
1537	int status;
1538
1539	/* Credential */
1540
1541	p = xdr_reserve_space(xdr, 7 * sizeof(*p) +
1542			      ctx->gc_wire_ctx.len);
1543	if (!p)
1544		goto marshal_failed;
1545	*p++ = rpc_auth_gss;
1546	cred_len = p++;
1547
1548	spin_lock(&ctx->gc_seq_lock);
1549	req->rq_seqno = (ctx->gc_seq < MAXSEQ) ? ctx->gc_seq++ : MAXSEQ;
1550	spin_unlock(&ctx->gc_seq_lock);
1551	if (req->rq_seqno == MAXSEQ)
1552		goto expired;
1553	trace_rpcgss_seqno(task);
1554
1555	*p++ = cpu_to_be32(RPC_GSS_VERSION);
1556	*p++ = cpu_to_be32(ctx->gc_proc);
1557	*p++ = cpu_to_be32(req->rq_seqno);
1558	*p++ = cpu_to_be32(gss_cred->gc_service);
1559	p = xdr_encode_netobj(p, &ctx->gc_wire_ctx);
1560	*cred_len = cpu_to_be32((p - (cred_len + 1)) << 2);
1561
1562	/* Verifier */
1563
1564	/* We compute the checksum for the verifier over the xdr-encoded bytes
1565	 * starting with the xid and ending at the end of the credential: */
1566	iov.iov_base = req->rq_snd_buf.head[0].iov_base;
1567	iov.iov_len = (u8 *)p - (u8 *)iov.iov_base;
1568	xdr_buf_from_iov(&iov, &verf_buf);
1569
1570	p = xdr_reserve_space(xdr, sizeof(*p));
1571	if (!p)
1572		goto marshal_failed;
1573	*p++ = rpc_auth_gss;
1574	mic.data = (u8 *)(p + 1);
1575	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1576	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1577		goto expired;
1578	else if (maj_stat != 0)
1579		goto bad_mic;
1580	if (xdr_stream_encode_opaque_inline(xdr, (void **)&p, mic.len) < 0)
1581		goto marshal_failed;
1582	status = 0;
1583out:
1584	gss_put_ctx(ctx);
1585	return status;
1586expired:
1587	clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1588	status = -EKEYEXPIRED;
1589	goto out;
1590marshal_failed:
1591	status = -EMSGSIZE;
1592	goto out;
1593bad_mic:
1594	trace_rpcgss_get_mic(task, maj_stat);
1595	status = -EIO;
1596	goto out;
1597}
1598
1599static int gss_renew_cred(struct rpc_task *task)
1600{
1601	struct rpc_cred *oldcred = task->tk_rqstp->rq_cred;
1602	struct gss_cred *gss_cred = container_of(oldcred,
1603						 struct gss_cred,
1604						 gc_base);
1605	struct rpc_auth *auth = oldcred->cr_auth;
1606	struct auth_cred acred = {
1607		.cred = oldcred->cr_cred,
1608		.principal = gss_cred->gc_principal,
1609	};
1610	struct rpc_cred *new;
1611
1612	new = gss_lookup_cred(auth, &acred, RPCAUTH_LOOKUP_NEW);
1613	if (IS_ERR(new))
1614		return PTR_ERR(new);
 
1615	task->tk_rqstp->rq_cred = new;
1616	put_rpccred(oldcred);
1617	return 0;
1618}
1619
1620static int gss_cred_is_negative_entry(struct rpc_cred *cred)
1621{
1622	if (test_bit(RPCAUTH_CRED_NEGATIVE, &cred->cr_flags)) {
1623		unsigned long now = jiffies;
1624		unsigned long begin, expire;
1625		struct gss_cred *gss_cred;
1626
1627		gss_cred = container_of(cred, struct gss_cred, gc_base);
1628		begin = gss_cred->gc_upcall_timestamp;
1629		expire = begin + gss_expired_cred_retry_delay * HZ;
1630
1631		if (time_in_range_open(now, begin, expire))
1632			return 1;
1633	}
1634	return 0;
1635}
1636
1637/*
1638* Refresh credentials. XXX - finish
1639*/
1640static int
1641gss_refresh(struct rpc_task *task)
1642{
1643	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1644	int ret = 0;
1645
1646	if (gss_cred_is_negative_entry(cred))
1647		return -EKEYEXPIRED;
1648
1649	if (!test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags) &&
1650			!test_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags)) {
1651		ret = gss_renew_cred(task);
1652		if (ret < 0)
1653			goto out;
1654		cred = task->tk_rqstp->rq_cred;
1655	}
1656
1657	if (test_bit(RPCAUTH_CRED_NEW, &cred->cr_flags))
1658		ret = gss_refresh_upcall(task);
1659out:
1660	return ret;
1661}
1662
1663/* Dummy refresh routine: used only when destroying the context */
1664static int
1665gss_refresh_null(struct rpc_task *task)
1666{
1667	return 0;
1668}
1669
1670static int
1671gss_validate(struct rpc_task *task, struct xdr_stream *xdr)
1672{
1673	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1674	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1675	__be32		*p, *seq = NULL;
1676	struct kvec	iov;
1677	struct xdr_buf	verf_buf;
1678	struct xdr_netobj mic;
1679	u32		len, maj_stat;
1680	int		status;
1681
1682	p = xdr_inline_decode(xdr, 2 * sizeof(*p));
1683	if (!p)
1684		goto validate_failed;
1685	if (*p++ != rpc_auth_gss)
1686		goto validate_failed;
1687	len = be32_to_cpup(p);
1688	if (len > RPC_MAX_AUTH_SIZE)
1689		goto validate_failed;
1690	p = xdr_inline_decode(xdr, len);
1691	if (!p)
1692		goto validate_failed;
1693
1694	seq = kmalloc(4, GFP_NOFS);
1695	if (!seq)
1696		goto validate_failed;
1697	*seq = cpu_to_be32(task->tk_rqstp->rq_seqno);
1698	iov.iov_base = seq;
1699	iov.iov_len = 4;
1700	xdr_buf_from_iov(&iov, &verf_buf);
1701	mic.data = (u8 *)p;
1702	mic.len = len;
1703	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &verf_buf, &mic);
1704	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1705		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1706	if (maj_stat)
1707		goto bad_mic;
1708
1709	/* We leave it to unwrap to calculate au_rslack. For now we just
1710	 * calculate the length of the verifier: */
1711	cred->cr_auth->au_verfsize = XDR_QUADLEN(len) + 2;
 
1712	status = 0;
1713out:
1714	gss_put_ctx(ctx);
1715	kfree(seq);
1716	return status;
1717
1718validate_failed:
1719	status = -EIO;
1720	goto out;
1721bad_mic:
1722	trace_rpcgss_verify_mic(task, maj_stat);
1723	status = -EACCES;
1724	goto out;
1725}
1726
1727static int gss_wrap_req_integ(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1728			      struct rpc_task *task, struct xdr_stream *xdr)
 
1729{
1730	struct rpc_rqst *rqstp = task->tk_rqstp;
1731	struct xdr_buf integ_buf, *snd_buf = &rqstp->rq_snd_buf;
1732	struct xdr_netobj mic;
1733	__be32 *p, *integ_len;
1734	u32 offset, maj_stat;
1735
1736	p = xdr_reserve_space(xdr, 2 * sizeof(*p));
1737	if (!p)
1738		goto wrap_failed;
1739	integ_len = p++;
1740	*p = cpu_to_be32(rqstp->rq_seqno);
1741
1742	if (rpcauth_wrap_req_encode(task, xdr))
1743		goto wrap_failed;
1744
1745	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1746	if (xdr_buf_subsegment(snd_buf, &integ_buf,
1747				offset, snd_buf->len - offset))
1748		goto wrap_failed;
1749	*integ_len = cpu_to_be32(integ_buf.len);
1750
1751	p = xdr_reserve_space(xdr, 0);
1752	if (!p)
1753		goto wrap_failed;
1754	mic.data = (u8 *)(p + 1);
1755	maj_stat = gss_get_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
1756	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1757		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1758	else if (maj_stat)
1759		goto bad_mic;
1760	/* Check that the trailing MIC fit in the buffer, after the fact */
1761	if (xdr_stream_encode_opaque_inline(xdr, (void **)&p, mic.len) < 0)
1762		goto wrap_failed;
1763	return 0;
1764wrap_failed:
1765	return -EMSGSIZE;
1766bad_mic:
1767	trace_rpcgss_get_mic(task, maj_stat);
1768	return -EIO;
1769}
1770
1771static void
1772priv_release_snd_buf(struct rpc_rqst *rqstp)
1773{
1774	int i;
1775
1776	for (i=0; i < rqstp->rq_enc_pages_num; i++)
1777		__free_page(rqstp->rq_enc_pages[i]);
1778	kfree(rqstp->rq_enc_pages);
1779	rqstp->rq_release_snd_buf = NULL;
1780}
1781
1782static int
1783alloc_enc_pages(struct rpc_rqst *rqstp)
1784{
1785	struct xdr_buf *snd_buf = &rqstp->rq_snd_buf;
1786	int first, last, i;
1787
1788	if (rqstp->rq_release_snd_buf)
1789		rqstp->rq_release_snd_buf(rqstp);
1790
1791	if (snd_buf->page_len == 0) {
1792		rqstp->rq_enc_pages_num = 0;
1793		return 0;
1794	}
1795
1796	first = snd_buf->page_base >> PAGE_SHIFT;
1797	last = (snd_buf->page_base + snd_buf->page_len - 1) >> PAGE_SHIFT;
1798	rqstp->rq_enc_pages_num = last - first + 1 + 1;
1799	rqstp->rq_enc_pages
1800		= kmalloc_array(rqstp->rq_enc_pages_num,
1801				sizeof(struct page *),
1802				GFP_NOFS);
1803	if (!rqstp->rq_enc_pages)
1804		goto out;
1805	for (i=0; i < rqstp->rq_enc_pages_num; i++) {
1806		rqstp->rq_enc_pages[i] = alloc_page(GFP_NOFS);
1807		if (rqstp->rq_enc_pages[i] == NULL)
1808			goto out_free;
1809	}
1810	rqstp->rq_release_snd_buf = priv_release_snd_buf;
1811	return 0;
1812out_free:
1813	rqstp->rq_enc_pages_num = i;
1814	priv_release_snd_buf(rqstp);
1815out:
1816	return -EAGAIN;
1817}
1818
1819static int gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx,
1820			     struct rpc_task *task, struct xdr_stream *xdr)
 
1821{
1822	struct rpc_rqst *rqstp = task->tk_rqstp;
1823	struct xdr_buf	*snd_buf = &rqstp->rq_snd_buf;
1824	u32		pad, offset, maj_stat;
1825	int		status;
1826	__be32		*p, *opaque_len;
1827	struct page	**inpages;
1828	int		first;
1829	struct kvec	*iov;
1830
1831	status = -EIO;
1832	p = xdr_reserve_space(xdr, 2 * sizeof(*p));
1833	if (!p)
1834		goto wrap_failed;
1835	opaque_len = p++;
1836	*p = cpu_to_be32(rqstp->rq_seqno);
1837
1838	if (rpcauth_wrap_req_encode(task, xdr))
1839		goto wrap_failed;
1840
1841	status = alloc_enc_pages(rqstp);
1842	if (unlikely(status))
1843		goto wrap_failed;
1844	first = snd_buf->page_base >> PAGE_SHIFT;
1845	inpages = snd_buf->pages + first;
1846	snd_buf->pages = rqstp->rq_enc_pages;
1847	snd_buf->page_base -= first << PAGE_SHIFT;
1848	/*
1849	 * Move the tail into its own page, in case gss_wrap needs
1850	 * more space in the head when wrapping.
1851	 *
1852	 * Still... Why can't gss_wrap just slide the tail down?
1853	 */
1854	if (snd_buf->page_len || snd_buf->tail[0].iov_len) {
1855		char *tmp;
1856
1857		tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]);
1858		memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len);
1859		snd_buf->tail[0].iov_base = tmp;
1860	}
1861	offset = (u8 *)p - (u8 *)snd_buf->head[0].iov_base;
1862	maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages);
1863	/* slack space should prevent this ever happening: */
1864	if (unlikely(snd_buf->len > snd_buf->buflen))
1865		goto wrap_failed;
1866	/* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was
1867	 * done anyway, so it's safe to put the request on the wire: */
1868	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1869		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1870	else if (maj_stat)
1871		goto bad_wrap;
1872
1873	*opaque_len = cpu_to_be32(snd_buf->len - offset);
1874	/* guess whether the pad goes into the head or the tail: */
1875	if (snd_buf->page_len || snd_buf->tail[0].iov_len)
1876		iov = snd_buf->tail;
1877	else
1878		iov = snd_buf->head;
1879	p = iov->iov_base + iov->iov_len;
1880	pad = 3 - ((snd_buf->len - offset - 1) & 3);
1881	memset(p, 0, pad);
1882	iov->iov_len += pad;
1883	snd_buf->len += pad;
1884
1885	return 0;
1886wrap_failed:
1887	return status;
1888bad_wrap:
1889	trace_rpcgss_wrap(task, maj_stat);
1890	return -EIO;
1891}
1892
1893static int gss_wrap_req(struct rpc_task *task, struct xdr_stream *xdr)
1894{
1895	struct rpc_cred *cred = task->tk_rqstp->rq_cred;
1896	struct gss_cred	*gss_cred = container_of(cred, struct gss_cred,
1897			gc_base);
1898	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
1899	int status;
1900
1901	status = -EIO;
1902	if (ctx->gc_proc != RPC_GSS_PROC_DATA) {
1903		/* The spec seems a little ambiguous here, but I think that not
1904		 * wrapping context destruction requests makes the most sense.
1905		 */
1906		status = rpcauth_wrap_req_encode(task, xdr);
1907		goto out;
1908	}
1909	switch (gss_cred->gc_service) {
1910	case RPC_GSS_SVC_NONE:
1911		status = rpcauth_wrap_req_encode(task, xdr);
1912		break;
1913	case RPC_GSS_SVC_INTEGRITY:
1914		status = gss_wrap_req_integ(cred, ctx, task, xdr);
1915		break;
1916	case RPC_GSS_SVC_PRIVACY:
1917		status = gss_wrap_req_priv(cred, ctx, task, xdr);
1918		break;
1919	default:
1920		status = -EIO;
1921	}
1922out:
1923	gss_put_ctx(ctx);
1924	return status;
1925}
1926
1927static int
1928gss_unwrap_resp_auth(struct rpc_cred *cred)
 
 
 
 
 
 
 
 
1929{
1930	struct rpc_auth *auth = cred->cr_auth;
1931
1932	auth->au_rslack = auth->au_verfsize;
1933	auth->au_ralign = auth->au_verfsize;
1934	return 0;
 
 
1935}
1936
1937static int
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1938gss_unwrap_resp_integ(struct rpc_task *task, struct rpc_cred *cred,
1939		      struct gss_cl_ctx *ctx, struct rpc_rqst *rqstp,
1940		      struct xdr_stream *xdr)
1941{
1942	struct xdr_buf integ_buf, *rcv_buf = &rqstp->rq_rcv_buf;
1943	u32 data_offset, mic_offset, integ_len, maj_stat;
1944	struct rpc_auth *auth = cred->cr_auth;
1945	struct xdr_netobj mic;
1946	__be32 *p;
1947
1948	p = xdr_inline_decode(xdr, 2 * sizeof(*p));
1949	if (unlikely(!p))
 
 
 
1950		goto unwrap_failed;
1951	integ_len = be32_to_cpup(p++);
1952	if (integ_len & 3)
1953		goto unwrap_failed;
1954	data_offset = (u8 *)(p) - (u8 *)rcv_buf->head[0].iov_base;
1955	mic_offset = integ_len + data_offset;
1956	if (mic_offset > rcv_buf->len)
1957		goto unwrap_failed;
1958	if (be32_to_cpup(p) != rqstp->rq_seqno)
1959		goto bad_seqno;
 
 
1960
1961	if (xdr_buf_subsegment(rcv_buf, &integ_buf, data_offset, integ_len))
 
 
 
 
 
 
 
 
 
 
1962		goto unwrap_failed;
1963	if (xdr_buf_read_mic(rcv_buf, &mic, mic_offset))
 
1964		goto unwrap_failed;
1965	maj_stat = gss_verify_mic(ctx->gc_gss_ctx, &integ_buf, &mic);
 
 
 
 
 
 
 
1966	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
1967		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
1968	if (maj_stat != GSS_S_COMPLETE)
1969		goto bad_mic;
1970
1971	auth->au_rslack = auth->au_verfsize + 2 + 1 + XDR_QUADLEN(mic.len);
1972	auth->au_ralign = auth->au_verfsize + 2;
1973	return 0;
 
 
 
 
1974unwrap_failed:
1975	trace_rpcgss_unwrap_failed(task);
1976	return -EIO;
1977bad_seqno:
1978	trace_rpcgss_bad_seqno(task, rqstp->rq_seqno, be32_to_cpup(p));
1979	return -EIO;
1980bad_mic:
1981	trace_rpcgss_verify_mic(task, maj_stat);
1982	return -EIO;
1983}
1984
1985static int
1986gss_unwrap_resp_priv(struct rpc_task *task, struct rpc_cred *cred,
1987		     struct gss_cl_ctx *ctx, struct rpc_rqst *rqstp,
1988		     struct xdr_stream *xdr)
1989{
1990	struct xdr_buf *rcv_buf = &rqstp->rq_rcv_buf;
1991	struct kvec *head = rqstp->rq_rcv_buf.head;
1992	struct rpc_auth *auth = cred->cr_auth;
1993	unsigned int savedlen = rcv_buf->len;
1994	u32 offset, opaque_len, maj_stat;
1995	__be32 *p;
1996
1997	p = xdr_inline_decode(xdr, 2 * sizeof(*p));
1998	if (unlikely(!p))
1999		goto unwrap_failed;
2000	opaque_len = be32_to_cpup(p++);
2001	offset = (u8 *)(p) - (u8 *)head->iov_base;
2002	if (offset + opaque_len > rcv_buf->len)
2003		goto unwrap_failed;
2004	rcv_buf->len = offset + opaque_len;
2005
2006	maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
 
2007	if (maj_stat == GSS_S_CONTEXT_EXPIRED)
2008		clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
2009	if (maj_stat != GSS_S_COMPLETE)
2010		goto bad_unwrap;
2011	/* gss_unwrap decrypted the sequence number */
2012	if (be32_to_cpup(p++) != rqstp->rq_seqno)
2013		goto bad_seqno;
2014
2015	/* gss_unwrap redacts the opaque blob from the head iovec.
2016	 * rcv_buf has changed, thus the stream needs to be reset.
2017	 */
2018	xdr_init_decode(xdr, rcv_buf, p, rqstp);
2019
2020	auth->au_rslack = auth->au_verfsize + 2 +
2021			  XDR_QUADLEN(savedlen - rcv_buf->len);
2022	auth->au_ralign = auth->au_verfsize + 2 +
2023			  XDR_QUADLEN(savedlen - rcv_buf->len);
2024	return 0;
2025unwrap_failed:
2026	trace_rpcgss_unwrap_failed(task);
2027	return -EIO;
2028bad_seqno:
2029	trace_rpcgss_bad_seqno(task, rqstp->rq_seqno, be32_to_cpup(--p));
2030	return -EIO;
2031bad_unwrap:
2032	trace_rpcgss_unwrap(task, maj_stat);
2033	return -EIO;
2034}
2035
2036static bool
2037gss_seq_is_newer(u32 new, u32 old)
2038{
2039	return (s32)(new - old) > 0;
2040}
2041
2042static bool
2043gss_xmit_need_reencode(struct rpc_task *task)
2044{
2045	struct rpc_rqst *req = task->tk_rqstp;
2046	struct rpc_cred *cred = req->rq_cred;
2047	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
2048	u32 win, seq_xmit = 0;
2049	bool ret = true;
2050
2051	if (!ctx)
2052		goto out;
2053
2054	if (gss_seq_is_newer(req->rq_seqno, READ_ONCE(ctx->gc_seq)))
2055		goto out_ctx;
2056
2057	seq_xmit = READ_ONCE(ctx->gc_seq_xmit);
2058	while (gss_seq_is_newer(req->rq_seqno, seq_xmit)) {
2059		u32 tmp = seq_xmit;
2060
2061		seq_xmit = cmpxchg(&ctx->gc_seq_xmit, tmp, req->rq_seqno);
2062		if (seq_xmit == tmp) {
2063			ret = false;
2064			goto out_ctx;
2065		}
2066	}
2067
2068	win = ctx->gc_win;
2069	if (win > 0)
2070		ret = !gss_seq_is_newer(req->rq_seqno, seq_xmit - win);
2071
2072out_ctx:
2073	gss_put_ctx(ctx);
2074out:
2075	trace_rpcgss_need_reencode(task, seq_xmit, ret);
2076	return ret;
2077}
2078
2079static int
2080gss_unwrap_resp(struct rpc_task *task, struct xdr_stream *xdr)
2081{
2082	struct rpc_rqst *rqstp = task->tk_rqstp;
2083	struct rpc_cred *cred = rqstp->rq_cred;
2084	struct gss_cred *gss_cred = container_of(cred, struct gss_cred,
2085			gc_base);
2086	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);
2087	int status = -EIO;
2088
2089	if (ctx->gc_proc != RPC_GSS_PROC_DATA)
2090		goto out_decode;
2091	switch (gss_cred->gc_service) {
2092	case RPC_GSS_SVC_NONE:
2093		status = gss_unwrap_resp_auth(cred);
2094		break;
2095	case RPC_GSS_SVC_INTEGRITY:
2096		status = gss_unwrap_resp_integ(task, cred, ctx, rqstp, xdr);
2097		break;
2098	case RPC_GSS_SVC_PRIVACY:
2099		status = gss_unwrap_resp_priv(task, cred, ctx, rqstp, xdr);
2100		break;
2101	}
2102	if (status)
2103		goto out;
2104
2105out_decode:
2106	status = rpcauth_unwrap_resp_decode(task, xdr);
2107out:
2108	gss_put_ctx(ctx);
2109	return status;
2110}
2111
2112static const struct rpc_authops authgss_ops = {
2113	.owner		= THIS_MODULE,
2114	.au_flavor	= RPC_AUTH_GSS,
2115	.au_name	= "RPCSEC_GSS",
2116	.create		= gss_create,
2117	.destroy	= gss_destroy,
2118	.hash_cred	= gss_hash_cred,
2119	.lookup_cred	= gss_lookup_cred,
2120	.crcreate	= gss_create_cred,
2121	.list_pseudoflavors = gss_mech_list_pseudoflavors,
2122	.info2flavor	= gss_mech_info2flavor,
2123	.flavor2info	= gss_mech_flavor2info,
2124};
2125
2126static const struct rpc_credops gss_credops = {
2127	.cr_name		= "AUTH_GSS",
2128	.crdestroy		= gss_destroy_cred,
2129	.cr_init		= gss_cred_init,
2130	.crmatch		= gss_match,
2131	.crmarshal		= gss_marshal,
2132	.crrefresh		= gss_refresh,
2133	.crvalidate		= gss_validate,
2134	.crwrap_req		= gss_wrap_req,
2135	.crunwrap_resp		= gss_unwrap_resp,
2136	.crkey_timeout		= gss_key_timeout,
2137	.crstringify_acceptor	= gss_stringify_acceptor,
2138	.crneed_reencode	= gss_xmit_need_reencode,
2139};
2140
2141static const struct rpc_credops gss_nullops = {
2142	.cr_name		= "AUTH_GSS",
2143	.crdestroy		= gss_destroy_nullcred,
2144	.crmatch		= gss_match,
2145	.crmarshal		= gss_marshal,
2146	.crrefresh		= gss_refresh_null,
2147	.crvalidate		= gss_validate,
2148	.crwrap_req		= gss_wrap_req,
2149	.crunwrap_resp		= gss_unwrap_resp,
2150	.crstringify_acceptor	= gss_stringify_acceptor,
2151};
2152
2153static const struct rpc_pipe_ops gss_upcall_ops_v0 = {
2154	.upcall		= gss_v0_upcall,
2155	.downcall	= gss_pipe_downcall,
2156	.destroy_msg	= gss_pipe_destroy_msg,
2157	.open_pipe	= gss_pipe_open_v0,
2158	.release_pipe	= gss_pipe_release,
2159};
2160
2161static const struct rpc_pipe_ops gss_upcall_ops_v1 = {
2162	.upcall		= gss_v1_upcall,
2163	.downcall	= gss_pipe_downcall,
2164	.destroy_msg	= gss_pipe_destroy_msg,
2165	.open_pipe	= gss_pipe_open_v1,
2166	.release_pipe	= gss_pipe_release,
2167};
2168
2169static __net_init int rpcsec_gss_init_net(struct net *net)
2170{
2171	return gss_svc_init_net(net);
2172}
2173
2174static __net_exit void rpcsec_gss_exit_net(struct net *net)
2175{
2176	gss_svc_shutdown_net(net);
2177}
2178
2179static struct pernet_operations rpcsec_gss_net_ops = {
2180	.init = rpcsec_gss_init_net,
2181	.exit = rpcsec_gss_exit_net,
2182};
2183
2184/*
2185 * Initialize RPCSEC_GSS module
2186 */
2187static int __init init_rpcsec_gss(void)
2188{
2189	int err = 0;
2190
2191	err = rpcauth_register(&authgss_ops);
2192	if (err)
2193		goto out;
2194	err = gss_svc_init();
2195	if (err)
2196		goto out_unregister;
2197	err = register_pernet_subsys(&rpcsec_gss_net_ops);
2198	if (err)
2199		goto out_svc_exit;
2200	rpc_init_wait_queue(&pipe_version_rpc_waitqueue, "gss pipe version");
2201	return 0;
2202out_svc_exit:
2203	gss_svc_shutdown();
2204out_unregister:
2205	rpcauth_unregister(&authgss_ops);
2206out:
2207	return err;
2208}
2209
2210static void __exit exit_rpcsec_gss(void)
2211{
2212	unregister_pernet_subsys(&rpcsec_gss_net_ops);
2213	gss_svc_shutdown();
2214	rpcauth_unregister(&authgss_ops);
2215	rcu_barrier(); /* Wait for completion of call_rcu()'s */
2216}
2217
2218MODULE_ALIAS("rpc-auth-6");
2219MODULE_LICENSE("GPL");
2220module_param_named(expired_cred_retry_delay,
2221		   gss_expired_cred_retry_delay,
2222		   uint, 0644);
2223MODULE_PARM_DESC(expired_cred_retry_delay, "Timeout (in seconds) until "
2224		"the RPC engine retries an expired credential");
2225
2226module_param_named(key_expire_timeo,
2227		   gss_key_expire_timeo,
2228		   uint, 0644);
2229MODULE_PARM_DESC(key_expire_timeo, "Time (in seconds) at the end of a "
2230		"credential keys lifetime where the NFS layer cleans up "
2231		"prior to key expiration");
2232
2233module_init(init_rpcsec_gss)
2234module_exit(exit_rpcsec_gss)