summaryrefslogtreecommitdiffstats
path: root/net/sunrpc/svcauth_unix.c
blob: a0a953a430c29957e7204b03061da0604d8c4cf5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
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
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
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
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/module.h>
#include <linux/sunrpc/types.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svcsock.h>
#include <linux/sunrpc/svcauth.h>
#include <linux/err.h>
#include <linux/seq_file.h>
#include <linux/hash.h>
#include <linux/string.h>
#include <net/sock.h>

#define RPCDBG_FACILITY	RPCDBG_AUTH


/*
 * AUTHUNIX and AUTHNULL credentials are both handled here.
 * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
 * are always nobody (-2).  i.e. we do the same IP address checks for
 * AUTHNULL as for AUTHUNIX, and that is done here.
 */


struct unix_domain {
	struct auth_domain	h;
	int	addr_changes;
	/* other stuff later */
};

extern struct auth_ops svcauth_unix;

struct auth_domain *unix_domain_find(char *name)
{
	struct auth_domain *rv;
	struct unix_domain *new = NULL;

	rv = auth_domain_lookup(name, NULL);
	while(1) {
		if (rv) {
			if (new && rv != &new->h)
				auth_domain_put(&new->h);

			if (rv->flavour != &svcauth_unix) {
				auth_domain_put(rv);
				return NULL;
			}
			return rv;
		}

		new = kmalloc(sizeof(*new), GFP_KERNEL);
		if (new == NULL)
			return NULL;
		kref_init(&new->h.ref);
		new->h.name = kstrdup(name, GFP_KERNEL);
		new->h.flavour = &svcauth_unix;
		new->addr_changes = 0;
		rv = auth_domain_lookup(name, &new->h);
	}
}

static void svcauth_unix_domain_release(struct auth_domain *dom)
{
	struct unix_domain *ud = container_of(dom, struct unix_domain, h);

	kfree(dom->name);
	kfree(ud);
}


/**************************************************
 * cache for IP address to unix_domain
 * as needed by AUTH_UNIX
 */
#define	IP_HASHBITS	8
#define	IP_HASHMAX	(1<<IP_HASHBITS)
#define	IP_HASHMASK	(IP_HASHMAX-1)

struct ip_map {
	struct cache_head	h;
	char			m_class[8]; /* e.g. "nfsd" */
	struct in_addr		m_addr;
	struct unix_domain	*m_client;
	int			m_add_change;
};
static struct cache_head	*ip_table[IP_HASHMAX];

static void ip_map_put(struct kref *kref)
{
	struct cache_head *item = container_of(kref, struct cache_head, ref);
	struct ip_map *im = container_of(item, struct ip_map,h);

	if (test_bit(CACHE_VALID, &item->flags) &&
	    !test_bit(CACHE_NEGATIVE, &item->flags))
		auth_domain_put(&im->m_client->h);
	kfree(im);
}

#if IP_HASHBITS == 8
/* hash_long on a 64 bit machine is currently REALLY BAD for
 * IP addresses in reverse-endian (i.e. on a little-endian machine).
 * So use a trivial but reliable hash instead
 */
static inline int hash_ip(__be32 ip)
{
	int hash = (__force u32)ip ^ ((__force u32)ip>>16);
	return (hash ^ (hash>>8)) & 0xff;
}
#endif
static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
{
	struct ip_map *orig = container_of(corig, struct ip_map, h);
	struct ip_map *new = container_of(cnew, struct ip_map, h);
	return strcmp(orig->m_class, new->m_class) == 0
		&& orig->m_addr.s_addr == new->m_addr.s_addr;
}
static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
{
	struct ip_map *new = container_of(cnew, struct ip_map, h);
	struct ip_map *item = container_of(citem, struct ip_map, h);

	strcpy(new->m_class, item->m_class);
	new->m_addr.s_addr = item->m_addr.s_addr;
}
static void update(struct cache_head *cnew, struct cache_head *citem)
{
	struct ip_map *new = container_of(cnew, struct ip_map, h);
	struct ip_map *item = container_of(citem, struct ip_map, h);

	kref_get(&item->m_client->h.ref);
	new->m_client = item->m_client;
	new->m_add_change = item->m_add_change;
}
static struct cache_head *ip_map_alloc(void)
{
	struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
	if (i)
		return &i->h;
	else
		return NULL;
}

static void ip_map_request(struct cache_detail *cd,
				  struct cache_head *h,
				  char **bpp, int *blen)
{
	char text_addr[20];
	struct ip_map *im = container_of(h, struct ip_map, h);
	__be32 addr = im->m_addr.s_addr;
	
	snprintf(text_addr, 20, "%u.%u.%u.%u",
		 ntohl(addr) >> 24 & 0xff,
		 ntohl(addr) >> 16 & 0xff,
		 ntohl(addr) >>  8 & 0xff,
		 ntohl(addr) >>  0 & 0xff);

	qword_add(bpp, blen, im->m_class);
	qword_add(bpp, blen, text_addr);
	(*bpp)[-1] = '\n';
}

static struct ip_map *ip_map_lookup(char *class, struct in_addr addr);
static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry);

static int ip_map_parse(struct cache_detail *cd,
			  char *mesg, int mlen)
{
	/* class ipaddress [domainname] */
	/* should be safe just to use the start of the input buffer
	 * for scratch: */
	char *buf = mesg;
	int len;
	int b1,b2,b3,b4;
	char c;
	char class[8];
	struct in_addr addr;
	int err;

	struct ip_map *ipmp;
	struct auth_domain *dom;
	time_t expiry;

	if (mesg[mlen-1] != '\n')
		return -EINVAL;
	mesg[mlen-1] = 0;

	/* class */
	len = qword_get(&mesg, class, sizeof(class));
	if (len <= 0) return -EINVAL;

	/* ip address */
	len = qword_get(&mesg, buf, mlen);
	if (len <= 0) return -EINVAL;

	if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
		return -EINVAL;
	
	expiry = get_expiry(&mesg);
	if (expiry ==0)
		return -EINVAL;

	/* domainname, or empty for NEGATIVE */
	len = qword_get(&mesg, buf, mlen);
	if (len < 0) return -EINVAL;

	if (len) {
		dom = unix_domain_find(buf);
		if (dom == NULL)
			return -ENOENT;
	} else
		dom = NULL;

	addr.s_addr =
		htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);

	ipmp = ip_map_lookup(class,addr);
	if (ipmp) {
		err = ip_map_update(ipmp,
			     container_of(dom, struct unix_domain, h),
			     expiry);
	} else
		err = -ENOMEM;

	if (dom)
		auth_domain_put(dom);

	cache_flush();
	return err;
}

static int ip_map_show(struct seq_file *m,
		       struct cache_detail *cd,
		       struct cache_head *h)
{
	struct ip_map *im;
	struct in_addr addr;
	char *dom = "-no-domain-";

	if (h == NULL) {
		seq_puts(m, "#class IP domain\n");
		return 0;
	}
	im = container_of(h, struct ip_map, h);
	/* class addr domain */
	addr = im->m_addr;

	if (test_bit(CACHE_VALID, &h->flags) && 
	    !test_bit(CACHE_NEGATIVE, &h->flags))
		dom = im->m_client->h.name;

	seq_printf(m, "%s %d.%d.%d.%d %s\n",
		   im->m_class,
		   ntohl(addr.s_addr) >> 24 & 0xff,
		   ntohl(addr.s_addr) >> 16 & 0xff,
		   ntohl(addr.s_addr) >>  8 & 0xff,
		   ntohl(addr.s_addr) >>  0 & 0xff,
		   dom
		   );
	return 0;
}
	

struct cache_detail ip_map_cache = {
	.owner		= THIS_MODULE,
	.hash_size	= IP_HASHMAX,
	.hash_table	= ip_table,
	.name		= "auth.unix.ip",
	.cache_put	= ip_map_put,
	.cache_request	= ip_map_request,
	.cache_parse	= ip_map_parse,
	.cache_show	= ip_map_show,
	.match		= ip_map_match,
	.init		= ip_map_init,
	.update		= update,
	.alloc		= ip_map_alloc,
};

static struct ip_map *ip_map_lookup(char *class, struct in_addr addr)
{
	struct ip_map ip;
	struct cache_head *ch;

	strcpy(ip.m_class, class);
	ip.m_addr = addr;
	ch = sunrpc_cache_lookup(&ip_map_cache, &ip.h,
				 hash_str(class, IP_HASHBITS) ^
				 hash_ip(addr.s_addr));

	if (ch)
		return container_of(ch, struct ip_map, h);
	else
		return NULL;
}

static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry)
{
	struct ip_map ip;
	struct cache_head *ch;

	ip.m_client = udom;
	ip.h.flags = 0;
	if (!udom)
		set_bit(CACHE_NEGATIVE, &ip.h.flags);
	else {
		ip.m_add_change = udom->addr_changes;
		/* if this is from the legacy set_client system call,
		 * we need m_add_change to be one higher
		 */
		if (expiry == NEVER)
			ip.m_add_change++;
	}
	ip.h.expiry_time = expiry;
	ch = sunrpc_cache_update(&ip_map_cache,
				 &ip.h, &ipm->h,
				 hash_str(ipm->m_class, IP_HASHBITS) ^
				 hash_ip(ipm->m_addr.s_addr));
	if (!ch)
		return -ENOMEM;
	cache_put(ch, &ip_map_cache);
	return 0;
}

int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
{
	struct unix_domain *udom;
	struct ip_map *ipmp;

	if (dom->flavour != &svcauth_unix)
		return -EINVAL;
	udom = container_of(dom, struct unix_domain, h);
	ipmp = ip_map_lookup("nfsd", addr);

	if (ipmp)
		return ip_map_update(ipmp, udom, NEVER);
	else
		return -ENOMEM;
}

int auth_unix_forget_old(struct auth_domain *dom)
{
	struct unix_domain *udom;
	
	if (dom->flavour != &svcauth_unix)
		return -EINVAL;
	udom = container_of(dom, struct unix_domain, h);
	udom->addr_changes++;
	return 0;
}

struct auth_domain *auth_unix_lookup(struct in_addr addr)
{
	struct ip_map *ipm;
	struct auth_domain *rv;

	ipm = ip_map_lookup("nfsd", addr);

	if (!ipm)
		return NULL;
	if (cache_check(&ip_map_cache, &ipm->h, NULL))
		return NULL;

	if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
		if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
			auth_domain_put(&ipm->m_client->h);
		rv = NULL;
	} else {
		rv = &ipm->m_client->h;
		kref_get(&rv->ref);
	}
	cache_put(&ipm->h, &ip_map_cache);
	return rv;
}

void svcauth_unix_purge(void)
{
	cache_purge(&ip_map_cache);
}

static inline struct ip_map *
ip_map_cached_get(struct svc_rqst *rqstp)
{
	struct ip_map *ipm = rqstp->rq_sock->sk_info_authunix;
	if (ipm != NULL) {
		if (!cache_valid(&ipm->h)) {
			/*
			 * The entry has been invalidated since it was
			 * remembered, e.g. by a second mount from the
			 * same IP address.
			 */
			rqstp->rq_sock->sk_info_authunix = NULL;
			cache_put(&ipm->h, &ip_map_cache);
			return NULL;
		}
		cache_get(&ipm->h);
	}
	return ipm;
}

static inline void
ip_map_cached_put(struct svc_rqst *rqstp, struct ip_map *ipm)
{
	struct svc_sock *svsk = rqstp->rq_sock;

	if (svsk->sk_sock->type == SOCK_STREAM && svsk->sk_info_authunix == NULL)
		svsk->sk_info_authunix = ipm;	/* newly cached, keep the reference */
	else
		cache_put(&ipm->h, &ip_map_cache);
}

void
svcauth_unix_info_release(void *info)
{
	struct ip_map *ipm = info;
	cache_put(&ipm->h, &ip_map_cache);
}

static int
svcauth_unix_set_client(struct svc_rqst *rqstp)
{
	struct ip_map *ipm;

	rqstp->rq_client = NULL;
	if (rqstp->rq_proc == 0)
		return SVC_OK;

	ipm = ip_map_cached_get(rqstp);
	if (ipm == NULL)
		ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
				    rqstp->rq_addr.sin_addr);

	if (ipm == NULL)
		return SVC_DENIED;

	switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
		default:
			BUG();
		case -EAGAIN:
			return SVC_DROP;
		case -ENOENT:
			return SVC_DENIED;
		case 0:
			rqstp->rq_client = &ipm->m_client->h;
			kref_get(&rqstp->rq_client->ref);
			ip_map_cached_put(rqstp, ipm);
			break;
	}
	return SVC_OK;
}

static int
svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
{
	struct kvec	*argv = &rqstp->rq_arg.head[0];
	struct kvec	*resv = &rqstp->rq_res.head[0];
	struct svc_cred	*cred = &rqstp->rq_cred;

	cred->cr_group_info = NULL;
	rqstp->rq_client = NULL;

	if (argv->iov_len < 3*4)
		return SVC_GARBAGE;

	if (svc_getu32(argv) != 0) { 
		dprintk("svc: bad null cred\n");
		*authp = rpc_autherr_badcred;
		return SVC_DENIED;
	}
	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
		dprintk("svc: bad null verf\n");
		*authp = rpc_autherr_badverf;
		return SVC_DENIED;
	}

	/* Signal that mapping to nobody uid/gid is required */
	cred->cr_uid = (uid_t) -1;
	cred->cr_gid = (gid_t) -1;
	cred->cr_group_info = groups_alloc(0);
	if (cred->cr_group_info == NULL)
		return SVC_DROP; /* kmalloc failure - client must retry */

	/* Put NULL verifier */
	svc_putnl(resv, RPC_AUTH_NULL);
	svc_putnl(resv, 0);

	return SVC_OK;
}

static int
svcauth_null_release(struct svc_rqst *rqstp)
{
	if (rqstp->rq_client)
		auth_domain_put(rqstp->rq_client);
	rqstp->rq_client = NULL;
	if (rqstp->rq_cred.cr_group_info)
		put_group_info(rqstp->rq_cred.cr_group_info);
	rqstp->rq_cred.cr_group_info = NULL;

	return 0; /* don't drop */
}


struct auth_ops svcauth_null = {
	.name		= "null",
	.owner		= THIS_MODULE,
	.flavour	= RPC_AUTH_NULL,
	.accept 	= svcauth_null_accept,
	.release	= svcauth_null_release,
	.set_client	= svcauth_unix_set_client,
};


static int
svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
{
	struct kvec	*argv = &rqstp->rq_arg.head[0];
	struct kvec	*resv = &rqstp->rq_res.head[0];
	struct svc_cred	*cred = &rqstp->rq_cred;
	u32		slen, i;
	int		len   = argv->iov_len;

	cred->cr_group_info = NULL;
	rqstp->rq_client = NULL;

	if ((len -= 3*4) < 0)
		return SVC_GARBAGE;

	svc_getu32(argv);			/* length */
	svc_getu32(argv);			/* time stamp */
	slen = XDR_QUADLEN(svc_getnl(argv));	/* machname length */
	if (slen > 64 || (len -= (slen + 3)*4) < 0)
		goto badcred;
	argv->iov_base = (void*)((__be32*)argv->iov_base + slen);	/* skip machname */
	argv->iov_len -= slen*4;

	cred->cr_uid = svc_getnl(argv);		/* uid */
	cred->cr_gid = svc_getnl(argv);		/* gid */
	slen = svc_getnl(argv);			/* gids length */
	if (slen > 16 || (len -= (slen + 2)*4) < 0)
		goto badcred;
	cred->cr_group_info = groups_alloc(slen);
	if (cred->cr_group_info == NULL)
		return SVC_DROP;
	for (i = 0; i < slen; i++)
		GROUP_AT(cred->cr_group_info, i) = svc_getnl(argv);

	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
		*authp = rpc_autherr_badverf;
		return SVC_DENIED;
	}

	/* Put NULL verifier */
	svc_putnl(resv, RPC_AUTH_NULL);
	svc_putnl(resv, 0);

	return SVC_OK;

badcred:
	*authp = rpc_autherr_badcred;
	return SVC_DENIED;
}

static int
svcauth_unix_release(struct svc_rqst *rqstp)
{
	/* Verifier (such as it is) is already in place.
	 */
	if (rqstp->rq_client)
		auth_domain_put(rqstp->rq_client);
	rqstp->rq_client = NULL;
	if (rqstp->rq_cred.cr_group_info)
		put_group_info(rqstp->rq_cred.cr_group_info);
	rqstp->rq_cred.cr_group_info = NULL;

	return 0;
}


struct auth_ops svcauth_unix = {
	.name		= "unix",
	.owner		= THIS_MODULE,
	.flavour	= RPC_AUTH_UNIX,
	.accept 	= svcauth_unix_accept,
	.release	= svcauth_unix_release,
	.domain_release	= svcauth_unix_domain_release,
	.set_client	= svcauth_unix_set_client,
};

OpenPOWER on IntegriCloud