xref: /openbmc/linux/net/sunrpc/svcauth_unix.c (revision f42b3800)
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/sunrpc/gss_api.h>
9 #include <linux/err.h>
10 #include <linux/seq_file.h>
11 #include <linux/hash.h>
12 #include <linux/string.h>
13 #include <net/sock.h>
14 
15 #define RPCDBG_FACILITY	RPCDBG_AUTH
16 
17 
18 /*
19  * AUTHUNIX and AUTHNULL credentials are both handled here.
20  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
21  * are always nobody (-2).  i.e. we do the same IP address checks for
22  * AUTHNULL as for AUTHUNIX, and that is done here.
23  */
24 
25 
26 struct unix_domain {
27 	struct auth_domain	h;
28 	int	addr_changes;
29 	/* other stuff later */
30 };
31 
32 extern struct auth_ops svcauth_unix;
33 
34 struct auth_domain *unix_domain_find(char *name)
35 {
36 	struct auth_domain *rv;
37 	struct unix_domain *new = NULL;
38 
39 	rv = auth_domain_lookup(name, NULL);
40 	while(1) {
41 		if (rv) {
42 			if (new && rv != &new->h)
43 				auth_domain_put(&new->h);
44 
45 			if (rv->flavour != &svcauth_unix) {
46 				auth_domain_put(rv);
47 				return NULL;
48 			}
49 			return rv;
50 		}
51 
52 		new = kmalloc(sizeof(*new), GFP_KERNEL);
53 		if (new == NULL)
54 			return NULL;
55 		kref_init(&new->h.ref);
56 		new->h.name = kstrdup(name, GFP_KERNEL);
57 		if (new->h.name == NULL) {
58 			kfree(new);
59 			return NULL;
60 		}
61 		new->h.flavour = &svcauth_unix;
62 		new->addr_changes = 0;
63 		rv = auth_domain_lookup(name, &new->h);
64 	}
65 }
66 EXPORT_SYMBOL(unix_domain_find);
67 
68 static void svcauth_unix_domain_release(struct auth_domain *dom)
69 {
70 	struct unix_domain *ud = container_of(dom, struct unix_domain, h);
71 
72 	kfree(dom->name);
73 	kfree(ud);
74 }
75 
76 
77 /**************************************************
78  * cache for IP address to unix_domain
79  * as needed by AUTH_UNIX
80  */
81 #define	IP_HASHBITS	8
82 #define	IP_HASHMAX	(1<<IP_HASHBITS)
83 #define	IP_HASHMASK	(IP_HASHMAX-1)
84 
85 struct ip_map {
86 	struct cache_head	h;
87 	char			m_class[8]; /* e.g. "nfsd" */
88 	struct in_addr		m_addr;
89 	struct unix_domain	*m_client;
90 	int			m_add_change;
91 };
92 static struct cache_head	*ip_table[IP_HASHMAX];
93 
94 static void ip_map_put(struct kref *kref)
95 {
96 	struct cache_head *item = container_of(kref, struct cache_head, ref);
97 	struct ip_map *im = container_of(item, struct ip_map,h);
98 
99 	if (test_bit(CACHE_VALID, &item->flags) &&
100 	    !test_bit(CACHE_NEGATIVE, &item->flags))
101 		auth_domain_put(&im->m_client->h);
102 	kfree(im);
103 }
104 
105 #if IP_HASHBITS == 8
106 /* hash_long on a 64 bit machine is currently REALLY BAD for
107  * IP addresses in reverse-endian (i.e. on a little-endian machine).
108  * So use a trivial but reliable hash instead
109  */
110 static inline int hash_ip(__be32 ip)
111 {
112 	int hash = (__force u32)ip ^ ((__force u32)ip>>16);
113 	return (hash ^ (hash>>8)) & 0xff;
114 }
115 #endif
116 static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
117 {
118 	struct ip_map *orig = container_of(corig, struct ip_map, h);
119 	struct ip_map *new = container_of(cnew, struct ip_map, h);
120 	return strcmp(orig->m_class, new->m_class) == 0
121 		&& orig->m_addr.s_addr == new->m_addr.s_addr;
122 }
123 static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
124 {
125 	struct ip_map *new = container_of(cnew, struct ip_map, h);
126 	struct ip_map *item = container_of(citem, struct ip_map, h);
127 
128 	strcpy(new->m_class, item->m_class);
129 	new->m_addr.s_addr = item->m_addr.s_addr;
130 }
131 static void update(struct cache_head *cnew, struct cache_head *citem)
132 {
133 	struct ip_map *new = container_of(cnew, struct ip_map, h);
134 	struct ip_map *item = container_of(citem, struct ip_map, h);
135 
136 	kref_get(&item->m_client->h.ref);
137 	new->m_client = item->m_client;
138 	new->m_add_change = item->m_add_change;
139 }
140 static struct cache_head *ip_map_alloc(void)
141 {
142 	struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
143 	if (i)
144 		return &i->h;
145 	else
146 		return NULL;
147 }
148 
149 static void ip_map_request(struct cache_detail *cd,
150 				  struct cache_head *h,
151 				  char **bpp, int *blen)
152 {
153 	char text_addr[20];
154 	struct ip_map *im = container_of(h, struct ip_map, h);
155 	__be32 addr = im->m_addr.s_addr;
156 
157 	snprintf(text_addr, 20, "%u.%u.%u.%u",
158 		 ntohl(addr) >> 24 & 0xff,
159 		 ntohl(addr) >> 16 & 0xff,
160 		 ntohl(addr) >>  8 & 0xff,
161 		 ntohl(addr) >>  0 & 0xff);
162 
163 	qword_add(bpp, blen, im->m_class);
164 	qword_add(bpp, blen, text_addr);
165 	(*bpp)[-1] = '\n';
166 }
167 
168 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr);
169 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry);
170 
171 static int ip_map_parse(struct cache_detail *cd,
172 			  char *mesg, int mlen)
173 {
174 	/* class ipaddress [domainname] */
175 	/* should be safe just to use the start of the input buffer
176 	 * for scratch: */
177 	char *buf = mesg;
178 	int len;
179 	int b1,b2,b3,b4;
180 	char c;
181 	char class[8];
182 	struct in_addr addr;
183 	int err;
184 
185 	struct ip_map *ipmp;
186 	struct auth_domain *dom;
187 	time_t expiry;
188 
189 	if (mesg[mlen-1] != '\n')
190 		return -EINVAL;
191 	mesg[mlen-1] = 0;
192 
193 	/* class */
194 	len = qword_get(&mesg, class, sizeof(class));
195 	if (len <= 0) return -EINVAL;
196 
197 	/* ip address */
198 	len = qword_get(&mesg, buf, mlen);
199 	if (len <= 0) return -EINVAL;
200 
201 	if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
202 		return -EINVAL;
203 
204 	expiry = get_expiry(&mesg);
205 	if (expiry ==0)
206 		return -EINVAL;
207 
208 	/* domainname, or empty for NEGATIVE */
209 	len = qword_get(&mesg, buf, mlen);
210 	if (len < 0) return -EINVAL;
211 
212 	if (len) {
213 		dom = unix_domain_find(buf);
214 		if (dom == NULL)
215 			return -ENOENT;
216 	} else
217 		dom = NULL;
218 
219 	addr.s_addr =
220 		htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
221 
222 	ipmp = ip_map_lookup(class,addr);
223 	if (ipmp) {
224 		err = ip_map_update(ipmp,
225 			     container_of(dom, struct unix_domain, h),
226 			     expiry);
227 	} else
228 		err = -ENOMEM;
229 
230 	if (dom)
231 		auth_domain_put(dom);
232 
233 	cache_flush();
234 	return err;
235 }
236 
237 static int ip_map_show(struct seq_file *m,
238 		       struct cache_detail *cd,
239 		       struct cache_head *h)
240 {
241 	struct ip_map *im;
242 	struct in_addr addr;
243 	char *dom = "-no-domain-";
244 
245 	if (h == NULL) {
246 		seq_puts(m, "#class IP domain\n");
247 		return 0;
248 	}
249 	im = container_of(h, struct ip_map, h);
250 	/* class addr domain */
251 	addr = im->m_addr;
252 
253 	if (test_bit(CACHE_VALID, &h->flags) &&
254 	    !test_bit(CACHE_NEGATIVE, &h->flags))
255 		dom = im->m_client->h.name;
256 
257 	seq_printf(m, "%s %d.%d.%d.%d %s\n",
258 		   im->m_class,
259 		   ntohl(addr.s_addr) >> 24 & 0xff,
260 		   ntohl(addr.s_addr) >> 16 & 0xff,
261 		   ntohl(addr.s_addr) >>  8 & 0xff,
262 		   ntohl(addr.s_addr) >>  0 & 0xff,
263 		   dom
264 		   );
265 	return 0;
266 }
267 
268 
269 struct cache_detail ip_map_cache = {
270 	.owner		= THIS_MODULE,
271 	.hash_size	= IP_HASHMAX,
272 	.hash_table	= ip_table,
273 	.name		= "auth.unix.ip",
274 	.cache_put	= ip_map_put,
275 	.cache_request	= ip_map_request,
276 	.cache_parse	= ip_map_parse,
277 	.cache_show	= ip_map_show,
278 	.match		= ip_map_match,
279 	.init		= ip_map_init,
280 	.update		= update,
281 	.alloc		= ip_map_alloc,
282 };
283 
284 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr)
285 {
286 	struct ip_map ip;
287 	struct cache_head *ch;
288 
289 	strcpy(ip.m_class, class);
290 	ip.m_addr = addr;
291 	ch = sunrpc_cache_lookup(&ip_map_cache, &ip.h,
292 				 hash_str(class, IP_HASHBITS) ^
293 				 hash_ip(addr.s_addr));
294 
295 	if (ch)
296 		return container_of(ch, struct ip_map, h);
297 	else
298 		return NULL;
299 }
300 
301 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry)
302 {
303 	struct ip_map ip;
304 	struct cache_head *ch;
305 
306 	ip.m_client = udom;
307 	ip.h.flags = 0;
308 	if (!udom)
309 		set_bit(CACHE_NEGATIVE, &ip.h.flags);
310 	else {
311 		ip.m_add_change = udom->addr_changes;
312 		/* if this is from the legacy set_client system call,
313 		 * we need m_add_change to be one higher
314 		 */
315 		if (expiry == NEVER)
316 			ip.m_add_change++;
317 	}
318 	ip.h.expiry_time = expiry;
319 	ch = sunrpc_cache_update(&ip_map_cache,
320 				 &ip.h, &ipm->h,
321 				 hash_str(ipm->m_class, IP_HASHBITS) ^
322 				 hash_ip(ipm->m_addr.s_addr));
323 	if (!ch)
324 		return -ENOMEM;
325 	cache_put(ch, &ip_map_cache);
326 	return 0;
327 }
328 
329 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
330 {
331 	struct unix_domain *udom;
332 	struct ip_map *ipmp;
333 
334 	if (dom->flavour != &svcauth_unix)
335 		return -EINVAL;
336 	udom = container_of(dom, struct unix_domain, h);
337 	ipmp = ip_map_lookup("nfsd", addr);
338 
339 	if (ipmp)
340 		return ip_map_update(ipmp, udom, NEVER);
341 	else
342 		return -ENOMEM;
343 }
344 EXPORT_SYMBOL(auth_unix_add_addr);
345 
346 int auth_unix_forget_old(struct auth_domain *dom)
347 {
348 	struct unix_domain *udom;
349 
350 	if (dom->flavour != &svcauth_unix)
351 		return -EINVAL;
352 	udom = container_of(dom, struct unix_domain, h);
353 	udom->addr_changes++;
354 	return 0;
355 }
356 EXPORT_SYMBOL(auth_unix_forget_old);
357 
358 struct auth_domain *auth_unix_lookup(struct in_addr addr)
359 {
360 	struct ip_map *ipm;
361 	struct auth_domain *rv;
362 
363 	ipm = ip_map_lookup("nfsd", addr);
364 
365 	if (!ipm)
366 		return NULL;
367 	if (cache_check(&ip_map_cache, &ipm->h, NULL))
368 		return NULL;
369 
370 	if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
371 		if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
372 			auth_domain_put(&ipm->m_client->h);
373 		rv = NULL;
374 	} else {
375 		rv = &ipm->m_client->h;
376 		kref_get(&rv->ref);
377 	}
378 	cache_put(&ipm->h, &ip_map_cache);
379 	return rv;
380 }
381 EXPORT_SYMBOL(auth_unix_lookup);
382 
383 void svcauth_unix_purge(void)
384 {
385 	cache_purge(&ip_map_cache);
386 }
387 EXPORT_SYMBOL(svcauth_unix_purge);
388 
389 static inline struct ip_map *
390 ip_map_cached_get(struct svc_rqst *rqstp)
391 {
392 	struct ip_map *ipm = NULL;
393 	struct svc_xprt *xprt = rqstp->rq_xprt;
394 
395 	if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) {
396 		spin_lock(&xprt->xpt_lock);
397 		ipm = xprt->xpt_auth_cache;
398 		if (ipm != NULL) {
399 			if (!cache_valid(&ipm->h)) {
400 				/*
401 				 * The entry has been invalidated since it was
402 				 * remembered, e.g. by a second mount from the
403 				 * same IP address.
404 				 */
405 				xprt->xpt_auth_cache = NULL;
406 				spin_unlock(&xprt->xpt_lock);
407 				cache_put(&ipm->h, &ip_map_cache);
408 				return NULL;
409 			}
410 			cache_get(&ipm->h);
411 		}
412 		spin_unlock(&xprt->xpt_lock);
413 	}
414 	return ipm;
415 }
416 
417 static inline void
418 ip_map_cached_put(struct svc_rqst *rqstp, struct ip_map *ipm)
419 {
420 	struct svc_xprt *xprt = rqstp->rq_xprt;
421 
422 	if (test_bit(XPT_CACHE_AUTH, &xprt->xpt_flags)) {
423 		spin_lock(&xprt->xpt_lock);
424 		if (xprt->xpt_auth_cache == NULL) {
425 			/* newly cached, keep the reference */
426 			xprt->xpt_auth_cache = ipm;
427 			ipm = NULL;
428 		}
429 		spin_unlock(&xprt->xpt_lock);
430 	}
431 	if (ipm)
432 		cache_put(&ipm->h, &ip_map_cache);
433 }
434 
435 void
436 svcauth_unix_info_release(void *info)
437 {
438 	struct ip_map *ipm = info;
439 	cache_put(&ipm->h, &ip_map_cache);
440 }
441 
442 /****************************************************************************
443  * auth.unix.gid cache
444  * simple cache to map a UID to a list of GIDs
445  * because AUTH_UNIX aka AUTH_SYS has a max of 16
446  */
447 #define	GID_HASHBITS	8
448 #define	GID_HASHMAX	(1<<GID_HASHBITS)
449 #define	GID_HASHMASK	(GID_HASHMAX - 1)
450 
451 struct unix_gid {
452 	struct cache_head	h;
453 	uid_t			uid;
454 	struct group_info	*gi;
455 };
456 static struct cache_head	*gid_table[GID_HASHMAX];
457 
458 static void unix_gid_put(struct kref *kref)
459 {
460 	struct cache_head *item = container_of(kref, struct cache_head, ref);
461 	struct unix_gid *ug = container_of(item, struct unix_gid, h);
462 	if (test_bit(CACHE_VALID, &item->flags) &&
463 	    !test_bit(CACHE_NEGATIVE, &item->flags))
464 		put_group_info(ug->gi);
465 	kfree(ug);
466 }
467 
468 static int unix_gid_match(struct cache_head *corig, struct cache_head *cnew)
469 {
470 	struct unix_gid *orig = container_of(corig, struct unix_gid, h);
471 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
472 	return orig->uid == new->uid;
473 }
474 static void unix_gid_init(struct cache_head *cnew, struct cache_head *citem)
475 {
476 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
477 	struct unix_gid *item = container_of(citem, struct unix_gid, h);
478 	new->uid = item->uid;
479 }
480 static void unix_gid_update(struct cache_head *cnew, struct cache_head *citem)
481 {
482 	struct unix_gid *new = container_of(cnew, struct unix_gid, h);
483 	struct unix_gid *item = container_of(citem, struct unix_gid, h);
484 
485 	get_group_info(item->gi);
486 	new->gi = item->gi;
487 }
488 static struct cache_head *unix_gid_alloc(void)
489 {
490 	struct unix_gid *g = kmalloc(sizeof(*g), GFP_KERNEL);
491 	if (g)
492 		return &g->h;
493 	else
494 		return NULL;
495 }
496 
497 static void unix_gid_request(struct cache_detail *cd,
498 			     struct cache_head *h,
499 			     char **bpp, int *blen)
500 {
501 	char tuid[20];
502 	struct unix_gid *ug = container_of(h, struct unix_gid, h);
503 
504 	snprintf(tuid, 20, "%u", ug->uid);
505 	qword_add(bpp, blen, tuid);
506 	(*bpp)[-1] = '\n';
507 }
508 
509 static struct unix_gid *unix_gid_lookup(uid_t uid);
510 extern struct cache_detail unix_gid_cache;
511 
512 static int unix_gid_parse(struct cache_detail *cd,
513 			char *mesg, int mlen)
514 {
515 	/* uid expiry Ngid gid0 gid1 ... gidN-1 */
516 	int uid;
517 	int gids;
518 	int rv;
519 	int i;
520 	int err;
521 	time_t expiry;
522 	struct unix_gid ug, *ugp;
523 
524 	if (mlen <= 0 || mesg[mlen-1] != '\n')
525 		return -EINVAL;
526 	mesg[mlen-1] = 0;
527 
528 	rv = get_int(&mesg, &uid);
529 	if (rv)
530 		return -EINVAL;
531 	ug.uid = uid;
532 
533 	expiry = get_expiry(&mesg);
534 	if (expiry == 0)
535 		return -EINVAL;
536 
537 	rv = get_int(&mesg, &gids);
538 	if (rv || gids < 0 || gids > 8192)
539 		return -EINVAL;
540 
541 	ug.gi = groups_alloc(gids);
542 	if (!ug.gi)
543 		return -ENOMEM;
544 
545 	for (i = 0 ; i < gids ; i++) {
546 		int gid;
547 		rv = get_int(&mesg, &gid);
548 		err = -EINVAL;
549 		if (rv)
550 			goto out;
551 		GROUP_AT(ug.gi, i) = gid;
552 	}
553 
554 	ugp = unix_gid_lookup(uid);
555 	if (ugp) {
556 		struct cache_head *ch;
557 		ug.h.flags = 0;
558 		ug.h.expiry_time = expiry;
559 		ch = sunrpc_cache_update(&unix_gid_cache,
560 					 &ug.h, &ugp->h,
561 					 hash_long(uid, GID_HASHBITS));
562 		if (!ch)
563 			err = -ENOMEM;
564 		else {
565 			err = 0;
566 			cache_put(ch, &unix_gid_cache);
567 		}
568 	} else
569 		err = -ENOMEM;
570  out:
571 	if (ug.gi)
572 		put_group_info(ug.gi);
573 	return err;
574 }
575 
576 static int unix_gid_show(struct seq_file *m,
577 			 struct cache_detail *cd,
578 			 struct cache_head *h)
579 {
580 	struct unix_gid *ug;
581 	int i;
582 	int glen;
583 
584 	if (h == NULL) {
585 		seq_puts(m, "#uid cnt: gids...\n");
586 		return 0;
587 	}
588 	ug = container_of(h, struct unix_gid, h);
589 	if (test_bit(CACHE_VALID, &h->flags) &&
590 	    !test_bit(CACHE_NEGATIVE, &h->flags))
591 		glen = ug->gi->ngroups;
592 	else
593 		glen = 0;
594 
595 	seq_printf(m, "%d %d:", ug->uid, glen);
596 	for (i = 0; i < glen; i++)
597 		seq_printf(m, " %d", GROUP_AT(ug->gi, i));
598 	seq_printf(m, "\n");
599 	return 0;
600 }
601 
602 struct cache_detail unix_gid_cache = {
603 	.owner		= THIS_MODULE,
604 	.hash_size	= GID_HASHMAX,
605 	.hash_table	= gid_table,
606 	.name		= "auth.unix.gid",
607 	.cache_put	= unix_gid_put,
608 	.cache_request	= unix_gid_request,
609 	.cache_parse	= unix_gid_parse,
610 	.cache_show	= unix_gid_show,
611 	.match		= unix_gid_match,
612 	.init		= unix_gid_init,
613 	.update		= unix_gid_update,
614 	.alloc		= unix_gid_alloc,
615 };
616 
617 static struct unix_gid *unix_gid_lookup(uid_t uid)
618 {
619 	struct unix_gid ug;
620 	struct cache_head *ch;
621 
622 	ug.uid = uid;
623 	ch = sunrpc_cache_lookup(&unix_gid_cache, &ug.h,
624 				 hash_long(uid, GID_HASHBITS));
625 	if (ch)
626 		return container_of(ch, struct unix_gid, h);
627 	else
628 		return NULL;
629 }
630 
631 static int unix_gid_find(uid_t uid, struct group_info **gip,
632 			 struct svc_rqst *rqstp)
633 {
634 	struct unix_gid *ug = unix_gid_lookup(uid);
635 	if (!ug)
636 		return -EAGAIN;
637 	switch (cache_check(&unix_gid_cache, &ug->h, &rqstp->rq_chandle)) {
638 	case -ENOENT:
639 		*gip = NULL;
640 		return 0;
641 	case 0:
642 		*gip = ug->gi;
643 		get_group_info(*gip);
644 		return 0;
645 	default:
646 		return -EAGAIN;
647 	}
648 }
649 
650 int
651 svcauth_unix_set_client(struct svc_rqst *rqstp)
652 {
653 	struct sockaddr_in *sin = svc_addr_in(rqstp);
654 	struct ip_map *ipm;
655 
656 	rqstp->rq_client = NULL;
657 	if (rqstp->rq_proc == 0)
658 		return SVC_OK;
659 
660 	ipm = ip_map_cached_get(rqstp);
661 	if (ipm == NULL)
662 		ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
663 				    sin->sin_addr);
664 
665 	if (ipm == NULL)
666 		return SVC_DENIED;
667 
668 	switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
669 		default:
670 			BUG();
671 		case -EAGAIN:
672 		case -ETIMEDOUT:
673 			return SVC_DROP;
674 		case -ENOENT:
675 			return SVC_DENIED;
676 		case 0:
677 			rqstp->rq_client = &ipm->m_client->h;
678 			kref_get(&rqstp->rq_client->ref);
679 			ip_map_cached_put(rqstp, ipm);
680 			break;
681 	}
682 	return SVC_OK;
683 }
684 
685 EXPORT_SYMBOL(svcauth_unix_set_client);
686 
687 static int
688 svcauth_null_accept(struct svc_rqst *rqstp, __be32 *authp)
689 {
690 	struct kvec	*argv = &rqstp->rq_arg.head[0];
691 	struct kvec	*resv = &rqstp->rq_res.head[0];
692 	struct svc_cred	*cred = &rqstp->rq_cred;
693 
694 	cred->cr_group_info = NULL;
695 	rqstp->rq_client = NULL;
696 
697 	if (argv->iov_len < 3*4)
698 		return SVC_GARBAGE;
699 
700 	if (svc_getu32(argv) != 0) {
701 		dprintk("svc: bad null cred\n");
702 		*authp = rpc_autherr_badcred;
703 		return SVC_DENIED;
704 	}
705 	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
706 		dprintk("svc: bad null verf\n");
707 		*authp = rpc_autherr_badverf;
708 		return SVC_DENIED;
709 	}
710 
711 	/* Signal that mapping to nobody uid/gid is required */
712 	cred->cr_uid = (uid_t) -1;
713 	cred->cr_gid = (gid_t) -1;
714 	cred->cr_group_info = groups_alloc(0);
715 	if (cred->cr_group_info == NULL)
716 		return SVC_DROP; /* kmalloc failure - client must retry */
717 
718 	/* Put NULL verifier */
719 	svc_putnl(resv, RPC_AUTH_NULL);
720 	svc_putnl(resv, 0);
721 
722 	rqstp->rq_flavor = RPC_AUTH_NULL;
723 	return SVC_OK;
724 }
725 
726 static int
727 svcauth_null_release(struct svc_rqst *rqstp)
728 {
729 	if (rqstp->rq_client)
730 		auth_domain_put(rqstp->rq_client);
731 	rqstp->rq_client = NULL;
732 	if (rqstp->rq_cred.cr_group_info)
733 		put_group_info(rqstp->rq_cred.cr_group_info);
734 	rqstp->rq_cred.cr_group_info = NULL;
735 
736 	return 0; /* don't drop */
737 }
738 
739 
740 struct auth_ops svcauth_null = {
741 	.name		= "null",
742 	.owner		= THIS_MODULE,
743 	.flavour	= RPC_AUTH_NULL,
744 	.accept 	= svcauth_null_accept,
745 	.release	= svcauth_null_release,
746 	.set_client	= svcauth_unix_set_client,
747 };
748 
749 
750 static int
751 svcauth_unix_accept(struct svc_rqst *rqstp, __be32 *authp)
752 {
753 	struct kvec	*argv = &rqstp->rq_arg.head[0];
754 	struct kvec	*resv = &rqstp->rq_res.head[0];
755 	struct svc_cred	*cred = &rqstp->rq_cred;
756 	u32		slen, i;
757 	int		len   = argv->iov_len;
758 
759 	cred->cr_group_info = NULL;
760 	rqstp->rq_client = NULL;
761 
762 	if ((len -= 3*4) < 0)
763 		return SVC_GARBAGE;
764 
765 	svc_getu32(argv);			/* length */
766 	svc_getu32(argv);			/* time stamp */
767 	slen = XDR_QUADLEN(svc_getnl(argv));	/* machname length */
768 	if (slen > 64 || (len -= (slen + 3)*4) < 0)
769 		goto badcred;
770 	argv->iov_base = (void*)((__be32*)argv->iov_base + slen);	/* skip machname */
771 	argv->iov_len -= slen*4;
772 
773 	cred->cr_uid = svc_getnl(argv);		/* uid */
774 	cred->cr_gid = svc_getnl(argv);		/* gid */
775 	slen = svc_getnl(argv);			/* gids length */
776 	if (slen > 16 || (len -= (slen + 2)*4) < 0)
777 		goto badcred;
778 	if (unix_gid_find(cred->cr_uid, &cred->cr_group_info, rqstp)
779 	    == -EAGAIN)
780 		return SVC_DROP;
781 	if (cred->cr_group_info == NULL) {
782 		cred->cr_group_info = groups_alloc(slen);
783 		if (cred->cr_group_info == NULL)
784 			return SVC_DROP;
785 		for (i = 0; i < slen; i++)
786 			GROUP_AT(cred->cr_group_info, i) = svc_getnl(argv);
787 	} else {
788 		for (i = 0; i < slen ; i++)
789 			svc_getnl(argv);
790 	}
791 	if (svc_getu32(argv) != htonl(RPC_AUTH_NULL) || svc_getu32(argv) != 0) {
792 		*authp = rpc_autherr_badverf;
793 		return SVC_DENIED;
794 	}
795 
796 	/* Put NULL verifier */
797 	svc_putnl(resv, RPC_AUTH_NULL);
798 	svc_putnl(resv, 0);
799 
800 	rqstp->rq_flavor = RPC_AUTH_UNIX;
801 	return SVC_OK;
802 
803 badcred:
804 	*authp = rpc_autherr_badcred;
805 	return SVC_DENIED;
806 }
807 
808 static int
809 svcauth_unix_release(struct svc_rqst *rqstp)
810 {
811 	/* Verifier (such as it is) is already in place.
812 	 */
813 	if (rqstp->rq_client)
814 		auth_domain_put(rqstp->rq_client);
815 	rqstp->rq_client = NULL;
816 	if (rqstp->rq_cred.cr_group_info)
817 		put_group_info(rqstp->rq_cred.cr_group_info);
818 	rqstp->rq_cred.cr_group_info = NULL;
819 
820 	return 0;
821 }
822 
823 
824 struct auth_ops svcauth_unix = {
825 	.name		= "unix",
826 	.owner		= THIS_MODULE,
827 	.flavour	= RPC_AUTH_UNIX,
828 	.accept 	= svcauth_unix_accept,
829 	.release	= svcauth_unix_release,
830 	.domain_release	= svcauth_unix_domain_release,
831 	.set_client	= svcauth_unix_set_client,
832 };
833 
834