xref: /openbmc/linux/net/sunrpc/svcauth_unix.c (revision 64c70b1c)
1 #include <linux/types.h>
2 #include <linux/sched.h>
3 #include <linux/module.h>
4 #include <linux/sunrpc/types.h>
5 #include <linux/sunrpc/xdr.h>
6 #include <linux/sunrpc/svcsock.h>
7 #include <linux/sunrpc/svcauth.h>
8 #include <linux/err.h>
9 #include <linux/seq_file.h>
10 #include <linux/hash.h>
11 #include <linux/string.h>
12 #include <net/sock.h>
13 
14 #define RPCDBG_FACILITY	RPCDBG_AUTH
15 
16 
17 /*
18  * AUTHUNIX and AUTHNULL credentials are both handled here.
19  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
20  * are always nobody (-2).  i.e. we do the same IP address checks for
21  * AUTHNULL as for AUTHUNIX, and that is done here.
22  */
23 
24 
25 struct unix_domain {
26 	struct auth_domain	h;
27 	int	addr_changes;
28 	/* other stuff later */
29 };
30 
31 extern struct auth_ops svcauth_unix;
32 
33 struct auth_domain *unix_domain_find(char *name)
34 {
35 	struct auth_domain *rv;
36 	struct unix_domain *new = NULL;
37 
38 	rv = auth_domain_lookup(name, NULL);
39 	while(1) {
40 		if (rv) {
41 			if (new && rv != &new->h)
42 				auth_domain_put(&new->h);
43 
44 			if (rv->flavour != &svcauth_unix) {
45 				auth_domain_put(rv);
46 				return NULL;
47 			}
48 			return rv;
49 		}
50 
51 		new = kmalloc(sizeof(*new), GFP_KERNEL);
52 		if (new == NULL)
53 			return NULL;
54 		kref_init(&new->h.ref);
55 		new->h.name = kstrdup(name, GFP_KERNEL);
56 		if (new->h.name == NULL) {
57 			kfree(new);
58 			return NULL;
59 		}
60 		new->h.flavour = &svcauth_unix;
61 		new->addr_changes = 0;
62 		rv = auth_domain_lookup(name, &new->h);
63 	}
64 }
65 
66 static void svcauth_unix_domain_release(struct auth_domain *dom)
67 {
68 	struct unix_domain *ud = container_of(dom, struct unix_domain, h);
69 
70 	kfree(dom->name);
71 	kfree(ud);
72 }
73 
74 
75 /**************************************************
76  * cache for IP address to unix_domain
77  * as needed by AUTH_UNIX
78  */
79 #define	IP_HASHBITS	8
80 #define	IP_HASHMAX	(1<<IP_HASHBITS)
81 #define	IP_HASHMASK	(IP_HASHMAX-1)
82 
83 struct ip_map {
84 	struct cache_head	h;
85 	char			m_class[8]; /* e.g. "nfsd" */
86 	struct in_addr		m_addr;
87 	struct unix_domain	*m_client;
88 	int			m_add_change;
89 };
90 static struct cache_head	*ip_table[IP_HASHMAX];
91 
92 static void ip_map_put(struct kref *kref)
93 {
94 	struct cache_head *item = container_of(kref, struct cache_head, ref);
95 	struct ip_map *im = container_of(item, struct ip_map,h);
96 
97 	if (test_bit(CACHE_VALID, &item->flags) &&
98 	    !test_bit(CACHE_NEGATIVE, &item->flags))
99 		auth_domain_put(&im->m_client->h);
100 	kfree(im);
101 }
102 
103 #if IP_HASHBITS == 8
104 /* hash_long on a 64 bit machine is currently REALLY BAD for
105  * IP addresses in reverse-endian (i.e. on a little-endian machine).
106  * So use a trivial but reliable hash instead
107  */
108 static inline int hash_ip(__be32 ip)
109 {
110 	int hash = (__force u32)ip ^ ((__force u32)ip>>16);
111 	return (hash ^ (hash>>8)) & 0xff;
112 }
113 #endif
114 static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
115 {
116 	struct ip_map *orig = container_of(corig, struct ip_map, h);
117 	struct ip_map *new = container_of(cnew, struct ip_map, h);
118 	return strcmp(orig->m_class, new->m_class) == 0
119 		&& orig->m_addr.s_addr == new->m_addr.s_addr;
120 }
121 static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
122 {
123 	struct ip_map *new = container_of(cnew, struct ip_map, h);
124 	struct ip_map *item = container_of(citem, struct ip_map, h);
125 
126 	strcpy(new->m_class, item->m_class);
127 	new->m_addr.s_addr = item->m_addr.s_addr;
128 }
129 static void update(struct cache_head *cnew, struct cache_head *citem)
130 {
131 	struct ip_map *new = container_of(cnew, struct ip_map, h);
132 	struct ip_map *item = container_of(citem, struct ip_map, h);
133 
134 	kref_get(&item->m_client->h.ref);
135 	new->m_client = item->m_client;
136 	new->m_add_change = item->m_add_change;
137 }
138 static struct cache_head *ip_map_alloc(void)
139 {
140 	struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
141 	if (i)
142 		return &i->h;
143 	else
144 		return NULL;
145 }
146 
147 static void ip_map_request(struct cache_detail *cd,
148 				  struct cache_head *h,
149 				  char **bpp, int *blen)
150 {
151 	char text_addr[20];
152 	struct ip_map *im = container_of(h, struct ip_map, h);
153 	__be32 addr = im->m_addr.s_addr;
154 
155 	snprintf(text_addr, 20, "%u.%u.%u.%u",
156 		 ntohl(addr) >> 24 & 0xff,
157 		 ntohl(addr) >> 16 & 0xff,
158 		 ntohl(addr) >>  8 & 0xff,
159 		 ntohl(addr) >>  0 & 0xff);
160 
161 	qword_add(bpp, blen, im->m_class);
162 	qword_add(bpp, blen, text_addr);
163 	(*bpp)[-1] = '\n';
164 }
165 
166 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr);
167 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry);
168 
169 static int ip_map_parse(struct cache_detail *cd,
170 			  char *mesg, int mlen)
171 {
172 	/* class ipaddress [domainname] */
173 	/* should be safe just to use the start of the input buffer
174 	 * for scratch: */
175 	char *buf = mesg;
176 	int len;
177 	int b1,b2,b3,b4;
178 	char c;
179 	char class[8];
180 	struct in_addr addr;
181 	int err;
182 
183 	struct ip_map *ipmp;
184 	struct auth_domain *dom;
185 	time_t expiry;
186 
187 	if (mesg[mlen-1] != '\n')
188 		return -EINVAL;
189 	mesg[mlen-1] = 0;
190 
191 	/* class */
192 	len = qword_get(&mesg, class, sizeof(class));
193 	if (len <= 0) return -EINVAL;
194 
195 	/* ip address */
196 	len = qword_get(&mesg, buf, mlen);
197 	if (len <= 0) return -EINVAL;
198 
199 	if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
200 		return -EINVAL;
201 
202 	expiry = get_expiry(&mesg);
203 	if (expiry ==0)
204 		return -EINVAL;
205 
206 	/* domainname, or empty for NEGATIVE */
207 	len = qword_get(&mesg, buf, mlen);
208 	if (len < 0) return -EINVAL;
209 
210 	if (len) {
211 		dom = unix_domain_find(buf);
212 		if (dom == NULL)
213 			return -ENOENT;
214 	} else
215 		dom = NULL;
216 
217 	addr.s_addr =
218 		htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
219 
220 	ipmp = ip_map_lookup(class,addr);
221 	if (ipmp) {
222 		err = ip_map_update(ipmp,
223 			     container_of(dom, struct unix_domain, h),
224 			     expiry);
225 	} else
226 		err = -ENOMEM;
227 
228 	if (dom)
229 		auth_domain_put(dom);
230 
231 	cache_flush();
232 	return err;
233 }
234 
235 static int ip_map_show(struct seq_file *m,
236 		       struct cache_detail *cd,
237 		       struct cache_head *h)
238 {
239 	struct ip_map *im;
240 	struct in_addr addr;
241 	char *dom = "-no-domain-";
242 
243 	if (h == NULL) {
244 		seq_puts(m, "#class IP domain\n");
245 		return 0;
246 	}
247 	im = container_of(h, struct ip_map, h);
248 	/* class addr domain */
249 	addr = im->m_addr;
250 
251 	if (test_bit(CACHE_VALID, &h->flags) &&
252 	    !test_bit(CACHE_NEGATIVE, &h->flags))
253 		dom = im->m_client->h.name;
254 
255 	seq_printf(m, "%s %d.%d.%d.%d %s\n",
256 		   im->m_class,
257 		   ntohl(addr.s_addr) >> 24 & 0xff,
258 		   ntohl(addr.s_addr) >> 16 & 0xff,
259 		   ntohl(addr.s_addr) >>  8 & 0xff,
260 		   ntohl(addr.s_addr) >>  0 & 0xff,
261 		   dom
262 		   );
263 	return 0;
264 }
265 
266 
267 struct cache_detail ip_map_cache = {
268 	.owner		= THIS_MODULE,
269 	.hash_size	= IP_HASHMAX,
270 	.hash_table	= ip_table,
271 	.name		= "auth.unix.ip",
272 	.cache_put	= ip_map_put,
273 	.cache_request	= ip_map_request,
274 	.cache_parse	= ip_map_parse,
275 	.cache_show	= ip_map_show,
276 	.match		= ip_map_match,
277 	.init		= ip_map_init,
278 	.update		= update,
279 	.alloc		= ip_map_alloc,
280 };
281 
282 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr)
283 {
284 	struct ip_map ip;
285 	struct cache_head *ch;
286 
287 	strcpy(ip.m_class, class);
288 	ip.m_addr = addr;
289 	ch = sunrpc_cache_lookup(&ip_map_cache, &ip.h,
290 				 hash_str(class, IP_HASHBITS) ^
291 				 hash_ip(addr.s_addr));
292 
293 	if (ch)
294 		return container_of(ch, struct ip_map, h);
295 	else
296 		return NULL;
297 }
298 
299 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry)
300 {
301 	struct ip_map ip;
302 	struct cache_head *ch;
303 
304 	ip.m_client = udom;
305 	ip.h.flags = 0;
306 	if (!udom)
307 		set_bit(CACHE_NEGATIVE, &ip.h.flags);
308 	else {
309 		ip.m_add_change = udom->addr_changes;
310 		/* if this is from the legacy set_client system call,
311 		 * we need m_add_change to be one higher
312 		 */
313 		if (expiry == NEVER)
314 			ip.m_add_change++;
315 	}
316 	ip.h.expiry_time = expiry;
317 	ch = sunrpc_cache_update(&ip_map_cache,
318 				 &ip.h, &ipm->h,
319 				 hash_str(ipm->m_class, IP_HASHBITS) ^
320 				 hash_ip(ipm->m_addr.s_addr));
321 	if (!ch)
322 		return -ENOMEM;
323 	cache_put(ch, &ip_map_cache);
324 	return 0;
325 }
326 
327 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
328 {
329 	struct unix_domain *udom;
330 	struct ip_map *ipmp;
331 
332 	if (dom->flavour != &svcauth_unix)
333 		return -EINVAL;
334 	udom = container_of(dom, struct unix_domain, h);
335 	ipmp = ip_map_lookup("nfsd", addr);
336 
337 	if (ipmp)
338 		return ip_map_update(ipmp, udom, NEVER);
339 	else
340 		return -ENOMEM;
341 }
342 
343 int auth_unix_forget_old(struct auth_domain *dom)
344 {
345 	struct unix_domain *udom;
346 
347 	if (dom->flavour != &svcauth_unix)
348 		return -EINVAL;
349 	udom = container_of(dom, struct unix_domain, h);
350 	udom->addr_changes++;
351 	return 0;
352 }
353 
354 struct auth_domain *auth_unix_lookup(struct in_addr addr)
355 {
356 	struct ip_map *ipm;
357 	struct auth_domain *rv;
358 
359 	ipm = ip_map_lookup("nfsd", addr);
360 
361 	if (!ipm)
362 		return NULL;
363 	if (cache_check(&ip_map_cache, &ipm->h, NULL))
364 		return NULL;
365 
366 	if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
367 		if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
368 			auth_domain_put(&ipm->m_client->h);
369 		rv = NULL;
370 	} else {
371 		rv = &ipm->m_client->h;
372 		kref_get(&rv->ref);
373 	}
374 	cache_put(&ipm->h, &ip_map_cache);
375 	return rv;
376 }
377 
378 void svcauth_unix_purge(void)
379 {
380 	cache_purge(&ip_map_cache);
381 }
382 
383 static inline struct ip_map *
384 ip_map_cached_get(struct svc_rqst *rqstp)
385 {
386 	struct ip_map *ipm;
387 	struct svc_sock *svsk = rqstp->rq_sock;
388 	spin_lock(&svsk->sk_lock);
389 	ipm = svsk->sk_info_authunix;
390 	if (ipm != NULL) {
391 		if (!cache_valid(&ipm->h)) {
392 			/*
393 			 * The entry has been invalidated since it was
394 			 * remembered, e.g. by a second mount from the
395 			 * same IP address.
396 			 */
397 			svsk->sk_info_authunix = NULL;
398 			spin_unlock(&svsk->sk_lock);
399 			cache_put(&ipm->h, &ip_map_cache);
400 			return NULL;
401 		}
402 		cache_get(&ipm->h);
403 	}
404 	spin_unlock(&svsk->sk_lock);
405 	return ipm;
406 }
407 
408 static inline void
409 ip_map_cached_put(struct svc_rqst *rqstp, struct ip_map *ipm)
410 {
411 	struct svc_sock *svsk = rqstp->rq_sock;
412 
413 	spin_lock(&svsk->sk_lock);
414 	if (svsk->sk_sock->type == SOCK_STREAM &&
415 	    svsk->sk_info_authunix == NULL) {
416 		/* newly cached, keep the reference */
417 		svsk->sk_info_authunix = ipm;
418 		ipm = NULL;
419 	}
420 	spin_unlock(&svsk->sk_lock);
421 	if (ipm)
422 		cache_put(&ipm->h, &ip_map_cache);
423 }
424 
425 void
426 svcauth_unix_info_release(void *info)
427 {
428 	struct ip_map *ipm = info;
429 	cache_put(&ipm->h, &ip_map_cache);
430 }
431 
432 /****************************************************************************
433  * auth.unix.gid cache
434  * simple cache to map a UID to a list of GIDs
435  * because AUTH_UNIX aka AUTH_SYS has a max of 16
436  */
437 #define	GID_HASHBITS	8
438 #define	GID_HASHMAX	(1<<GID_HASHBITS)
439 #define	GID_HASHMASK	(GID_HASHMAX - 1)
440 
441 struct unix_gid {
442 	struct cache_head	h;
443 	uid_t			uid;
444 	struct group_info	*gi;
445 };
446 static struct cache_head	*gid_table[GID_HASHMAX];
447 
448 static void unix_gid_put(struct kref *kref)
449 {
450 	struct cache_head *item = container_of(kref, struct cache_head, ref);
451 	struct unix_gid *ug = container_of(item, struct unix_gid, h);
452 	if (test_bit(CACHE_VALID, &item->flags) &&
453 	    !test_bit(CACHE_NEGATIVE, &item->flags))
454 		put_group_info(ug->gi);
455 	kfree(ug);
456 }
457 
458 static int unix_gid_match(struct cache_head *corig, struct cache_head *cnew)
459 {
460 	struct unix_gid *orig = container_of(corig, struct unix_gid, h);
461 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
462 	return orig->uid == new->uid;
463 }
464 static void unix_gid_init(struct cache_head *cnew, struct cache_head *citem)
465 {
466 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
467 	struct unix_gid *item = container_of(citem, struct unix_gid, h);
468 	new->uid = item->uid;
469 }
470 static void unix_gid_update(struct cache_head *cnew, struct cache_head *citem)
471 {
472 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
473 	struct unix_gid *item = container_of(citem, struct unix_gid, h);
474 
475 	get_group_info(item->gi);
476 	new->gi = item->gi;
477 }
478 static struct cache_head *unix_gid_alloc(void)
479 {
480 	struct unix_gid *g = kmalloc(sizeof(*g), GFP_KERNEL);
481 	if (g)
482 		return &g->h;
483 	else
484 		return NULL;
485 }
486 
487 static void unix_gid_request(struct cache_detail *cd,
488 			     struct cache_head *h,
489 			     char **bpp, int *blen)
490 {
491 	char tuid[20];
492 	struct unix_gid *ug = container_of(h, struct unix_gid, h);
493 
494 	snprintf(tuid, 20, "%u", ug->uid);
495 	qword_add(bpp, blen, tuid);
496 	(*bpp)[-1] = '\n';
497 }
498 
499 static struct unix_gid *unix_gid_lookup(uid_t uid);
500 extern struct cache_detail unix_gid_cache;
501 
502 static int unix_gid_parse(struct cache_detail *cd,
503 			char *mesg, int mlen)
504 {
505 	/* uid expiry Ngid gid0 gid1 ... gidN-1 */
506 	int uid;
507 	int gids;
508 	int rv;
509 	int i;
510 	int err;
511 	time_t expiry;
512 	struct unix_gid ug, *ugp;
513 
514 	if (mlen <= 0 || mesg[mlen-1] != '\n')
515 		return -EINVAL;
516 	mesg[mlen-1] = 0;
517 
518 	rv = get_int(&mesg, &uid);
519 	if (rv)
520 		return -EINVAL;
521 	ug.uid = uid;
522 
523 	expiry = get_expiry(&mesg);
524 	if (expiry == 0)
525 		return -EINVAL;
526 
527 	rv = get_int(&mesg, &gids);
528 	if (rv || gids < 0 || gids > 8192)
529 		return -EINVAL;
530 
531 	ug.gi = groups_alloc(gids);
532 	if (!ug.gi)
533 		return -ENOMEM;
534 
535 	for (i = 0 ; i < gids ; i++) {
536 		int gid;
537 		rv = get_int(&mesg, &gid);
538 		err = -EINVAL;
539 		if (rv)
540 			goto out;
541 		GROUP_AT(ug.gi, i) = gid;
542 	}
543 
544 	ugp = unix_gid_lookup(uid);
545 	if (ugp) {
546 		struct cache_head *ch;
547 		ug.h.flags = 0;
548 		ug.h.expiry_time = expiry;
549 		ch = sunrpc_cache_update(&unix_gid_cache,
550 					 &ug.h, &ugp->h,
551 					 hash_long(uid, GID_HASHBITS));
552 		if (!ch)
553 			err = -ENOMEM;
554 		else {
555 			err = 0;
556 			cache_put(ch, &unix_gid_cache);
557 		}
558 	} else
559 		err = -ENOMEM;
560  out:
561 	if (ug.gi)
562 		put_group_info(ug.gi);
563 	return err;
564 }
565 
566 static int unix_gid_show(struct seq_file *m,
567 			 struct cache_detail *cd,
568 			 struct cache_head *h)
569 {
570 	struct unix_gid *ug;
571 	int i;
572 	int glen;
573 
574 	if (h == NULL) {
575 		seq_puts(m, "#uid cnt: gids...\n");
576 		return 0;
577 	}
578 	ug = container_of(h, struct unix_gid, h);
579 	if (test_bit(CACHE_VALID, &h->flags) &&
580 	    !test_bit(CACHE_NEGATIVE, &h->flags))
581 		glen = ug->gi->ngroups;
582 	else
583 		glen = 0;
584 
585 	seq_printf(m, "%d %d:", ug->uid, glen);
586 	for (i = 0; i < glen; i++)
587 		seq_printf(m, " %d", GROUP_AT(ug->gi, i));
588 	seq_printf(m, "\n");
589 	return 0;
590 }
591 
592 struct cache_detail unix_gid_cache = {
593 	.owner		= THIS_MODULE,
594 	.hash_size	= GID_HASHMAX,
595 	.hash_table	= gid_table,
596 	.name		= "auth.unix.gid",
597 	.cache_put	= unix_gid_put,
598 	.cache_request	= unix_gid_request,
599 	.cache_parse	= unix_gid_parse,
600 	.cache_show	= unix_gid_show,
601 	.match		= unix_gid_match,
602 	.init		= unix_gid_init,
603 	.update		= unix_gid_update,
604 	.alloc		= unix_gid_alloc,
605 };
606 
607 static struct unix_gid *unix_gid_lookup(uid_t uid)
608 {
609 	struct unix_gid ug;
610 	struct cache_head *ch;
611 
612 	ug.uid = uid;
613 	ch = sunrpc_cache_lookup(&unix_gid_cache, &ug.h,
614 				 hash_long(uid, GID_HASHBITS));
615 	if (ch)
616 		return container_of(ch, struct unix_gid, h);
617 	else
618 		return NULL;
619 }
620 
621 static int unix_gid_find(uid_t uid, struct group_info **gip,
622 			 struct svc_rqst *rqstp)
623 {
624 	struct unix_gid *ug = unix_gid_lookup(uid);
625 	if (!ug)
626 		return -EAGAIN;
627 	switch (cache_check(&unix_gid_cache, &ug->h, &rqstp->rq_chandle)) {
628 	case -ENOENT:
629 		*gip = NULL;
630 		return 0;
631 	case 0:
632 		*gip = ug->gi;
633 		get_group_info(*gip);
634 		return 0;
635 	default:
636 		return -EAGAIN;
637 	}
638 }
639 
640 static int
641 svcauth_unix_set_client(struct svc_rqst *rqstp)
642 {
643 	struct sockaddr_in *sin = svc_addr_in(rqstp);
644 	struct ip_map *ipm;
645 
646 	rqstp->rq_client = NULL;
647 	if (rqstp->rq_proc == 0)
648 		return SVC_OK;
649 
650 	ipm = ip_map_cached_get(rqstp);
651 	if (ipm == NULL)
652 		ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
653 				    sin->sin_addr);
654 
655 	if (ipm == NULL)
656 		return SVC_DENIED;
657 
658 	switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
659 		default:
660 			BUG();
661 		case -EAGAIN:
662 		case -ETIMEDOUT:
663 			return SVC_DROP;
664 		case -ENOENT:
665 			return SVC_DENIED;
666 		case 0:
667 			rqstp->rq_client = &ipm->m_client->h;
668 			kref_get(&rqstp->rq_client->ref);
669 			ip_map_cached_put(rqstp, ipm);
670 			break;
671 	}
672 	return SVC_OK;
673 }
674 
675 static int
676 svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
677 {
678 	struct kvec	*argv = &rqstp->rq_arg.head[0];
679 	struct kvec	*resv = &rqstp->rq_res.head[0];
680 	struct svc_cred	*cred = &rqstp->rq_cred;
681 
682 	cred->cr_group_info = NULL;
683 	rqstp->rq_client = NULL;
684 
685 	if (argv->iov_len < 3*4)
686 		return SVC_GARBAGE;
687 
688 	if (svc_getu32(argv) != 0) {
689 		dprintk("svc: bad null cred\n");
690 		*authp = rpc_autherr_badcred;
691 		return SVC_DENIED;
692 	}
693 	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
694 		dprintk("svc: bad null verf\n");
695 		*authp = rpc_autherr_badverf;
696 		return SVC_DENIED;
697 	}
698 
699 	/* Signal that mapping to nobody uid/gid is required */
700 	cred->cr_uid = (uid_t) -1;
701 	cred->cr_gid = (gid_t) -1;
702 	cred->cr_group_info = groups_alloc(0);
703 	if (cred->cr_group_info == NULL)
704 		return SVC_DROP; /* kmalloc failure - client must retry */
705 
706 	/* Put NULL verifier */
707 	svc_putnl(resv, RPC_AUTH_NULL);
708 	svc_putnl(resv, 0);
709 
710 	return SVC_OK;
711 }
712 
713 static int
714 svcauth_null_release(struct svc_rqst *rqstp)
715 {
716 	if (rqstp->rq_client)
717 		auth_domain_put(rqstp->rq_client);
718 	rqstp->rq_client = NULL;
719 	if (rqstp->rq_cred.cr_group_info)
720 		put_group_info(rqstp->rq_cred.cr_group_info);
721 	rqstp->rq_cred.cr_group_info = NULL;
722 
723 	return 0; /* don't drop */
724 }
725 
726 
727 struct auth_ops svcauth_null = {
728 	.name		= "null",
729 	.owner		= THIS_MODULE,
730 	.flavour	= RPC_AUTH_NULL,
731 	.accept 	= svcauth_null_accept,
732 	.release	= svcauth_null_release,
733 	.set_client	= svcauth_unix_set_client,
734 };
735 
736 
737 static int
738 svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
739 {
740 	struct kvec	*argv = &rqstp->rq_arg.head[0];
741 	struct kvec	*resv = &rqstp->rq_res.head[0];
742 	struct svc_cred	*cred = &rqstp->rq_cred;
743 	u32		slen, i;
744 	int		len   = argv->iov_len;
745 
746 	cred->cr_group_info = NULL;
747 	rqstp->rq_client = NULL;
748 
749 	if ((len -= 3*4) < 0)
750 		return SVC_GARBAGE;
751 
752 	svc_getu32(argv);			/* length */
753 	svc_getu32(argv);			/* time stamp */
754 	slen = XDR_QUADLEN(svc_getnl(argv));	/* machname length */
755 	if (slen > 64 || (len -= (slen + 3)*4) < 0)
756 		goto badcred;
757 	argv->iov_base = (void*)((__be32*)argv->iov_base + slen);	/* skip machname */
758 	argv->iov_len -= slen*4;
759 
760 	cred->cr_uid = svc_getnl(argv);		/* uid */
761 	cred->cr_gid = svc_getnl(argv);		/* gid */
762 	slen = svc_getnl(argv);			/* gids length */
763 	if (slen > 16 || (len -= (slen + 2)*4) < 0)
764 		goto badcred;
765 	if (unix_gid_find(cred->cr_uid, &cred->cr_group_info, rqstp)
766 	    == -EAGAIN)
767 		return SVC_DROP;
768 	if (cred->cr_group_info == NULL) {
769 		cred->cr_group_info = groups_alloc(slen);
770 		if (cred->cr_group_info == NULL)
771 			return SVC_DROP;
772 		for (i = 0; i < slen; i++)
773 			GROUP_AT(cred->cr_group_info, i) = svc_getnl(argv);
774 	} else {
775 		for (i = 0; i < slen ; i++)
776 			svc_getnl(argv);
777 	}
778 	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
779 		*authp = rpc_autherr_badverf;
780 		return SVC_DENIED;
781 	}
782 
783 	/* Put NULL verifier */
784 	svc_putnl(resv, RPC_AUTH_NULL);
785 	svc_putnl(resv, 0);
786 
787 	return SVC_OK;
788 
789 badcred:
790 	*authp = rpc_autherr_badcred;
791 	return SVC_DENIED;
792 }
793 
794 static int
795 svcauth_unix_release(struct svc_rqst *rqstp)
796 {
797 	/* Verifier (such as it is) is already in place.
798 	 */
799 	if (rqstp->rq_client)
800 		auth_domain_put(rqstp->rq_client);
801 	rqstp->rq_client = NULL;
802 	if (rqstp->rq_cred.cr_group_info)
803 		put_group_info(rqstp->rq_cred.cr_group_info);
804 	rqstp->rq_cred.cr_group_info = NULL;
805 
806 	return 0;
807 }
808 
809 
810 struct auth_ops svcauth_unix = {
811 	.name		= "unix",
812 	.owner		= THIS_MODULE,
813 	.flavour	= RPC_AUTH_UNIX,
814 	.accept 	= svcauth_unix_accept,
815 	.release	= svcauth_unix_release,
816 	.domain_release	= svcauth_unix_domain_release,
817 	.set_client	= svcauth_unix_set_client,
818 };
819 
820