mon.c 15.0 KB
Newer Older
L
Linus Torvalds 已提交
1 2 3 4 5 6 7 8 9 10 11
/*
 * linux/fs/lockd/mon.c
 *
 * The kernel statd client.
 *
 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/types.h>
#include <linux/utsname.h>
#include <linux/kernel.h>
12 13
#include <linux/ktime.h>

L
Linus Torvalds 已提交
14
#include <linux/sunrpc/clnt.h>
15
#include <linux/sunrpc/xprtsock.h>
L
Linus Torvalds 已提交
16 17 18
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>

19 20
#include <asm/unaligned.h>

L
Linus Torvalds 已提交
21
#define NLMDBG_FACILITY		NLMDBG_MONITOR
22 23 24 25 26 27 28 29 30 31 32 33
#define NSM_PROGRAM		100024
#define NSM_VERSION		1

enum {
	NSMPROC_NULL,
	NSMPROC_STAT,
	NSMPROC_MON,
	NSMPROC_UNMON,
	NSMPROC_UNMON_ALL,
	NSMPROC_SIMU_CRASH,
	NSMPROC_NOTIFY,
};
L
Linus Torvalds 已提交
34

35
struct nsm_args {
36
	struct nsm_private	*priv;
37 38 39 40 41 42 43 44 45 46 47 48
	u32			prog;		/* RPC callback info */
	u32			vers;
	u32			proc;

	char			*mon_name;
};

struct nsm_res {
	u32			status;
	u32			state;
};

L
Linus Torvalds 已提交
49
static struct rpc_program	nsm_program;
50 51
static				LIST_HEAD(nsm_handles);
static				DEFINE_SPINLOCK(nsm_lock);
L
Linus Torvalds 已提交
52 53 54 55

/*
 * Local NSM state
 */
56
u32	__read_mostly		nsm_local_state;
57
int	__read_mostly		nsm_use_hostnames;
L
Linus Torvalds 已提交
58

59 60 61 62 63
static inline struct sockaddr *nsm_addr(const struct nsm_handle *nsm)
{
	return (struct sockaddr *)&nsm->sm_addr;
}

64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100
static void nsm_display_ipv4_address(const struct sockaddr *sap, char *buf,
				     const size_t len)
{
	const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
	snprintf(buf, len, "%pI4", &sin->sin_addr.s_addr);
}

static void nsm_display_ipv6_address(const struct sockaddr *sap, char *buf,
				     const size_t len)
{
	const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;

	if (ipv6_addr_v4mapped(&sin6->sin6_addr))
		snprintf(buf, len, "%pI4", &sin6->sin6_addr.s6_addr32[3]);
	else if (sin6->sin6_scope_id != 0)
		snprintf(buf, len, "%pI6%%%u", &sin6->sin6_addr,
				sin6->sin6_scope_id);
	else
		snprintf(buf, len, "%pI6", &sin6->sin6_addr);
}

static void nsm_display_address(const struct sockaddr *sap,
				char *buf, const size_t len)
{
	switch (sap->sa_family) {
	case AF_INET:
		nsm_display_ipv4_address(sap, buf, len);
		break;
	case AF_INET6:
		nsm_display_ipv6_address(sap, buf, len);
		break;
	default:
		snprintf(buf, len, "unsupported address family");
		break;
	}
}

C
Chuck Lever 已提交
101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120
static struct rpc_clnt *nsm_create(void)
{
	struct sockaddr_in sin = {
		.sin_family		= AF_INET,
		.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
	};
	struct rpc_create_args args = {
		.protocol		= XPRT_TRANSPORT_UDP,
		.address		= (struct sockaddr *)&sin,
		.addrsize		= sizeof(sin),
		.servername		= "rpc.statd",
		.program		= &nsm_program,
		.version		= NSM_VERSION,
		.authflavor		= RPC_AUTH_NULL,
	};

	return rpc_create(&args);
}

static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res)
L
Linus Torvalds 已提交
121 122 123
{
	struct rpc_clnt	*clnt;
	int		status;
124
	struct nsm_args args = {
125
		.priv		= &nsm->sm_priv,
126 127 128
		.prog		= NLM_PROGRAM,
		.vers		= 3,
		.proc		= NLMPROC_NSM_NOTIFY,
129
		.mon_name	= nsm->sm_mon_name,
130
	};
131 132 133 134
	struct rpc_message msg = {
		.rpc_argp	= &args,
		.rpc_resp	= res,
	};
L
Linus Torvalds 已提交
135 136 137 138

	clnt = nsm_create();
	if (IS_ERR(clnt)) {
		status = PTR_ERR(clnt);
139 140
		dprintk("lockd: failed to create NSM upcall transport, "
				"status=%d\n", status);
L
Linus Torvalds 已提交
141 142 143 144 145
		goto out;
	}

	memset(res, 0, sizeof(*res));

146 147
	msg.rpc_proc = &clnt->cl_procinfo[proc];
	status = rpc_call_sync(clnt, &msg, 0);
L
Linus Torvalds 已提交
148
	if (status < 0)
149 150
		dprintk("lockd: NSM upcall RPC failed, status=%d\n",
				status);
L
Linus Torvalds 已提交
151 152
	else
		status = 0;
153
	rpc_shutdown_client(clnt);
L
Linus Torvalds 已提交
154 155 156 157
 out:
	return status;
}

158 159 160 161 162 163 164 165 166 167
/**
 * nsm_monitor - Notify a peer in case we reboot
 * @host: pointer to nlm_host of peer to notify
 *
 * If this peer is not already monitored, this function sends an
 * upcall to the local rpc.statd to record the name/address of
 * the peer to notify in case we reboot.
 *
 * Returns zero if the peer is monitored by the local rpc.statd;
 * otherwise a negative errno value is returned.
L
Linus Torvalds 已提交
168
 */
169
int nsm_monitor(const struct nlm_host *host)
L
Linus Torvalds 已提交
170
{
171
	struct nsm_handle *nsm = host->h_nsmhandle;
L
Linus Torvalds 已提交
172 173 174
	struct nsm_res	res;
	int		status;

175
	dprintk("lockd: nsm_monitor(%s)\n", nsm->sm_name);
176 177

	if (nsm->sm_monitored)
178
		return 0;
L
Linus Torvalds 已提交
179

180 181 182 183 184 185
	/*
	 * Choose whether to record the caller_name or IP address of
	 * this peer in the local rpc.statd's database.
	 */
	nsm->sm_mon_name = nsm_use_hostnames ? nsm->sm_name : nsm->sm_addrbuf;

186
	status = nsm_mon_unmon(nsm, NSMPROC_MON, &res);
187
	if (unlikely(res.status != 0))
188
		status = -EIO;
189
	if (unlikely(status < 0)) {
190
		printk(KERN_NOTICE "lockd: cannot monitor %s\n", nsm->sm_name);
191 192 193 194 195 196 197 198 199
		return status;
	}

	nsm->sm_monitored = 1;
	if (unlikely(nsm_local_state != res.state)) {
		nsm_local_state = res.state;
		dprintk("lockd: NSM state changed to %d\n", nsm_local_state);
	}
	return 0;
L
Linus Torvalds 已提交
200 201
}

202 203 204 205 206 207 208
/**
 * nsm_unmonitor - Unregister peer notification
 * @host: pointer to nlm_host of peer to stop monitoring
 *
 * If this peer is monitored, this function sends an upcall to
 * tell the local rpc.statd not to send this peer a notification
 * when we reboot.
L
Linus Torvalds 已提交
209
 */
210
void nsm_unmonitor(const struct nlm_host *host)
L
Linus Torvalds 已提交
211
{
212
	struct nsm_handle *nsm = host->h_nsmhandle;
L
Linus Torvalds 已提交
213
	struct nsm_res	res;
214
	int status;
L
Linus Torvalds 已提交
215

216 217
	if (atomic_read(&nsm->sm_count) == 1
	 && nsm->sm_monitored && !nsm->sm_sticky) {
218
		dprintk("lockd: nsm_unmonitor(%s)\n", nsm->sm_name);
219

220
		status = nsm_mon_unmon(nsm, NSMPROC_UNMON, &res);
221 222
		if (res.status != 0)
			status = -EIO;
223
		if (status < 0)
224
			printk(KERN_NOTICE "lockd: cannot unmonitor %s\n",
225
					nsm->sm_name);
226 227
		else
			nsm->sm_monitored = 0;
228
	}
L
Linus Torvalds 已提交
229 230
}

231 232 233 234 235 236 237 238 239 240 241 242
static struct nsm_handle *nsm_lookup_hostname(const char *hostname,
					      const size_t len)
{
	struct nsm_handle *nsm;

	list_for_each_entry(nsm, &nsm_handles, sm_link)
		if (strlen(nsm->sm_name) == len &&
		    memcmp(nsm->sm_name, hostname, len) == 0)
			return nsm;
	return NULL;
}

243 244 245 246 247 248 249 250 251 252
static struct nsm_handle *nsm_lookup_addr(const struct sockaddr *sap)
{
	struct nsm_handle *nsm;

	list_for_each_entry(nsm, &nsm_handles, sm_link)
		if (nlm_cmp_addr(nsm_addr(nsm), sap))
			return nsm;
	return NULL;
}

253 254 255 256 257 258 259 260 261 262 263
static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)
{
	struct nsm_handle *nsm;

	list_for_each_entry(nsm, &nsm_handles, sm_link)
		if (memcmp(nsm->sm_priv.data, priv->data,
					sizeof(priv->data)) == 0)
			return nsm;
	return NULL;
}

264 265 266 267 268 269
/*
 * Construct a unique cookie to match this nsm_handle to this monitored
 * host.  It is passed to the local rpc.statd via NSMPROC_MON, and
 * returned via NLMPROC_SM_NOTIFY, in the "priv" field of these
 * requests.
 *
270 271 272 273 274 275 276 277 278 279
 * The NSM protocol requires that these cookies be unique while the
 * system is running.  We prefer a stronger requirement of making them
 * unique across reboots.  If user space bugs cause a stale cookie to
 * be sent to the kernel, it could cause the wrong host to lose its
 * lock state if cookies were not unique across reboots.
 *
 * The cookies are exposed only to local user space via loopback.  They
 * do not appear on the physical network.  If we want greater security
 * for some reason, nsm_init_private() could perform a one-way hash to
 * obscure the contents of the cookie.
280 281 282
 */
static void nsm_init_private(struct nsm_handle *nsm)
{
283 284
	u64 *p = (u64 *)&nsm->sm_priv.data;
	struct timespec ts;
285
	s64 ns;
286 287

	ktime_get_ts(&ts);
288 289 290
	ns = timespec_to_ns(&ts);
	put_unaligned(ns, p);
	put_unaligned((unsigned long)nsm, p + 1);
291 292
}

293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316
static struct nsm_handle *nsm_create_handle(const struct sockaddr *sap,
					    const size_t salen,
					    const char *hostname,
					    const size_t hostname_len)
{
	struct nsm_handle *new;

	new = kzalloc(sizeof(*new) + hostname_len + 1, GFP_KERNEL);
	if (unlikely(new == NULL))
		return NULL;

	atomic_set(&new->sm_count, 1);
	new->sm_name = (char *)(new + 1);
	memcpy(nsm_addr(new), sap, salen);
	new->sm_addrlen = salen;
	nsm_init_private(new);
	nsm_display_address((const struct sockaddr *)&new->sm_addr,
				new->sm_addrbuf, sizeof(new->sm_addrbuf));
	memcpy(new->sm_name, hostname, hostname_len);
	new->sm_name[hostname_len] = '\0';

	return new;
}

317
/**
318
 * nsm_get_handle - Find or create a cached nsm_handle
319 320 321 322 323
 * @sap: pointer to socket address of handle to find
 * @salen: length of socket address
 * @hostname: pointer to C string containing hostname to find
 * @hostname_len: length of C string
 *
324
 * Behavior is modulated by the global nsm_use_hostnames variable.
325
 *
326 327 328 329
 * Returns a cached nsm_handle after bumping its ref count, or
 * returns a fresh nsm_handle if a handle that matches @sap and/or
 * @hostname cannot be found in the handle cache.  Returns NULL if
 * an error occurs.
330
 */
331 332 333
struct nsm_handle *nsm_get_handle(const struct sockaddr *sap,
				  const size_t salen, const char *hostname,
				  const size_t hostname_len)
334
{
335
	struct nsm_handle *cached, *new = NULL;
336 337 338 339 340 341 342 343 344 345 346 347

	if (hostname && memchr(hostname, '/', hostname_len) != NULL) {
		if (printk_ratelimit()) {
			printk(KERN_WARNING "Invalid hostname \"%.*s\" "
					    "in NFS lock request\n",
				(int)hostname_len, hostname);
		}
		return NULL;
	}

retry:
	spin_lock(&nsm_lock);
348 349 350 351 352 353 354 355 356 357 358 359 360 361 362

	if (nsm_use_hostnames && hostname != NULL)
		cached = nsm_lookup_hostname(hostname, hostname_len);
	else
		cached = nsm_lookup_addr(sap);

	if (cached != NULL) {
		atomic_inc(&cached->sm_count);
		spin_unlock(&nsm_lock);
		kfree(new);
		dprintk("lockd: found nsm_handle for %s (%s), "
				"cnt %d\n", cached->sm_name,
				cached->sm_addrbuf,
				atomic_read(&cached->sm_count));
		return cached;
363
	}
364 365 366 367

	if (new != NULL) {
		list_add(&new->sm_link, &nsm_handles);
		spin_unlock(&nsm_lock);
368
		dprintk("lockd: created nsm_handle for %s (%s)\n",
369 370
				new->sm_name, new->sm_addrbuf);
		return new;
371
	}
372

373 374
	spin_unlock(&nsm_lock);

375 376
	new = nsm_create_handle(sap, salen, hostname, hostname_len);
	if (unlikely(new == NULL))
377 378 379 380
		return NULL;
	goto retry;
}

381 382 383 384 385 386 387 388 389 390 391 392 393 394
/**
 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle
 * @info: pointer to NLMPROC_SM_NOTIFY arguments
 *
 * Returns a matching nsm_handle if found in the nsm cache; the returned
 * nsm_handle's reference count is bumped and sm_monitored is cleared.
 * Otherwise returns NULL if some error occurred.
 */
struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)
{
	struct nsm_handle *cached;

	spin_lock(&nsm_lock);

395
	cached = nsm_lookup_priv(&info->priv);
396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417
	if (unlikely(cached == NULL)) {
		spin_unlock(&nsm_lock);
		dprintk("lockd: never saw rebooted peer '%.*s' before\n",
				info->len, info->mon);
		return cached;
	}

	atomic_inc(&cached->sm_count);
	spin_unlock(&nsm_lock);

	/*
	 * During subsequent lock activity, force a fresh
	 * notification to be set up for this host.
	 */
	cached->sm_monitored = 0;

	dprintk("lockd: host %s (%s) rebooted, cnt %d\n",
			cached->sm_name, cached->sm_addrbuf,
			atomic_read(&cached->sm_count));
	return cached;
}

418 419 420 421 422 423 424 425 426 427
/**
 * nsm_release - Release an NSM handle
 * @nsm: pointer to handle to be released
 *
 */
void nsm_release(struct nsm_handle *nsm)
{
	if (atomic_dec_and_lock(&nsm->sm_count, &nsm_lock)) {
		list_del(&nsm->sm_link);
		spin_unlock(&nsm_lock);
428 429
		dprintk("lockd: destroyed nsm_handle for %s (%s)\n",
				nsm->sm_name, nsm->sm_addrbuf);
430 431 432 433
		kfree(nsm);
	}
}

L
Linus Torvalds 已提交
434 435
/*
 * XDR functions for NSM.
436 437 438
 *
 * See http://www.opengroup.org/ for details on the Network
 * Status Monitor wire protocol.
L
Linus Torvalds 已提交
439 440
 */

441
static int encode_nsm_string(struct xdr_stream *xdr, const char *string)
442
{
443 444 445 446 447 448 449 450 451 452
	const u32 len = strlen(string);
	__be32 *p;

	if (unlikely(len > SM_MAXSTRLEN))
		return -EIO;
	p = xdr_reserve_space(xdr, sizeof(u32) + len);
	if (unlikely(p == NULL))
		return -EIO;
	xdr_encode_opaque(p, string, len);
	return 0;
453 454
}

455 456 457
/*
 * "mon_name" specifies the host to be monitored.
 */
458
static int encode_mon_name(struct xdr_stream *xdr, const struct nsm_args *argp)
459
{
460
	return encode_nsm_string(xdr, argp->mon_name);
461 462
}

463 464 465
/*
 * The "my_id" argument specifies the hostname and RPC procedure
 * to be called when the status manager receives notification
466
 * (via the NLMPROC_SM_NOTIFY call) that the state of host "mon_name"
467 468
 * has changed.
 */
469
static int encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
470
{
471 472 473 474 475 476 477 478 479
	int status;
	__be32 *p;

	status = encode_nsm_string(xdr, utsname()->nodename);
	if (unlikely(status != 0))
		return status;
	p = xdr_reserve_space(xdr, 3 * sizeof(u32));
	if (unlikely(p == NULL))
		return -EIO;
480 481 482
	*p++ = htonl(argp->prog);
	*p++ = htonl(argp->vers);
	*p++ = htonl(argp->proc);
483
	return 0;
484 485
}

486 487
/*
 * The "mon_id" argument specifies the non-private arguments
488
 * of an NSMPROC_MON or NSMPROC_UNMON call.
489
 */
490
static int encode_mon_id(struct xdr_stream *xdr, const struct nsm_args *argp)
491
{
492
	int status;
493

494 495 496 497
	status = encode_mon_name(xdr, argp);
	if (unlikely(status != 0))
		return status;
	return encode_my_id(xdr, argp);
498 499
}

500 501
/*
 * The "priv" argument may contain private information required
502 503
 * by the NSMPROC_MON call. This information will be supplied in the
 * NLMPROC_SM_NOTIFY call.
504
 */
505
static int encode_priv(struct xdr_stream *xdr, const struct nsm_args *argp)
506
{
507 508 509 510 511
	__be32 *p;

	p = xdr_reserve_space(xdr, SM_PRIV_SIZE);
	if (unlikely(p == NULL))
		return -EIO;
512
	xdr_encode_opaque_fixed(p, argp->priv->data, SM_PRIV_SIZE);
513
	return 0;
514 515
}

516 517
static int xdr_enc_mon(struct rpc_rqst *req, __be32 *p,
		       const struct nsm_args *argp)
L
Linus Torvalds 已提交
518
{
519 520
	struct xdr_stream xdr;
	int status;
521

522 523 524 525 526
	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	status = encode_mon_id(&xdr, argp);
	if (unlikely(status))
		return status;
	return encode_priv(&xdr, argp);
L
Linus Torvalds 已提交
527 528
}

529 530
static int xdr_enc_unmon(struct rpc_rqst *req, __be32 *p,
			 const struct nsm_args *argp)
L
Linus Torvalds 已提交
531
{
532 533 534 535
	struct xdr_stream xdr;

	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	return encode_mon_id(&xdr, argp);
L
Linus Torvalds 已提交
536 537
}

538 539
static int xdr_dec_stat_res(struct rpc_rqst *rqstp, __be32 *p,
			    struct nsm_res *resp)
L
Linus Torvalds 已提交
540
{
541 542 543 544 545 546
	struct xdr_stream xdr;

	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	p = xdr_inline_decode(&xdr, 2 * sizeof(u32));
	if (unlikely(p == NULL))
		return -EIO;
L
Linus Torvalds 已提交
547
	resp->status = ntohl(*p++);
548 549 550
	resp->state = ntohl(*p);

	dprintk("lockd: xdr_dec_stat_res status %d state %d\n",
L
Linus Torvalds 已提交
551 552 553 554
			resp->status, resp->state);
	return 0;
}

555 556
static int xdr_dec_stat(struct rpc_rqst *rqstp, __be32 *p,
			struct nsm_res *resp)
L
Linus Torvalds 已提交
557
{
558 559 560 561 562 563 564 565 566
	struct xdr_stream xdr;

	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	p = xdr_inline_decode(&xdr, sizeof(u32));
	if (unlikely(p == NULL))
		return -EIO;
	resp->state = ntohl(*p);

	dprintk("lockd: xdr_dec_stat state %d\n", resp->state);
L
Linus Torvalds 已提交
567 568 569 570
	return 0;
}

#define SM_my_name_sz	(1+XDR_QUADLEN(SM_MAXSTRLEN))
571 572 573
#define SM_my_id_sz	(SM_my_name_sz+3)
#define SM_mon_name_sz	(1+XDR_QUADLEN(SM_MAXSTRLEN))
#define SM_mon_id_sz	(SM_mon_name_sz+SM_my_id_sz)
574 575
#define SM_priv_sz	(XDR_QUADLEN(SM_PRIV_SIZE))
#define SM_mon_sz	(SM_mon_id_sz+SM_priv_sz)
L
Linus Torvalds 已提交
576 577 578 579
#define SM_monres_sz	2
#define SM_unmonres_sz	1

static struct rpc_procinfo	nsm_procedures[] = {
580 581
[NSMPROC_MON] = {
		.p_proc		= NSMPROC_MON,
582 583
		.p_encode	= (kxdrproc_t)xdr_enc_mon,
		.p_decode	= (kxdrproc_t)xdr_dec_stat_res,
584 585
		.p_arglen	= SM_mon_sz,
		.p_replen	= SM_monres_sz,
586
		.p_statidx	= NSMPROC_MON,
587
		.p_name		= "MONITOR",
L
Linus Torvalds 已提交
588
	},
589 590
[NSMPROC_UNMON] = {
		.p_proc		= NSMPROC_UNMON,
591 592
		.p_encode	= (kxdrproc_t)xdr_enc_unmon,
		.p_decode	= (kxdrproc_t)xdr_dec_stat,
593 594
		.p_arglen	= SM_mon_id_sz,
		.p_replen	= SM_unmonres_sz,
595
		.p_statidx	= NSMPROC_UNMON,
596
		.p_name		= "UNMONITOR",
L
Linus Torvalds 已提交
597 598 599 600
	},
};

static struct rpc_version	nsm_version1 = {
601 602
		.number		= 1,
		.nrprocs	= ARRAY_SIZE(nsm_procedures),
L
Linus Torvalds 已提交
603 604 605 606 607 608 609 610 611 612 613
		.procs		= nsm_procedures
};

static struct rpc_version *	nsm_version[] = {
	[1] = &nsm_version1,
};

static struct rpc_stat		nsm_stats;

static struct rpc_program	nsm_program = {
		.name		= "statd",
614
		.number		= NSM_PROGRAM,
615
		.nrvers		= ARRAY_SIZE(nsm_version),
L
Linus Torvalds 已提交
616 617 618
		.version	= nsm_version,
		.stats		= &nsm_stats
};
新手
引导
客服 返回
顶部