xref: /linux/net/sunrpc/svcauth_unix.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 
13 #define RPCDBG_FACILITY	RPCDBG_AUTH
14 
15 
16 /*
17  * AUTHUNIX and AUTHNULL credentials are both handled here.
18  * AUTHNULL is treated just like AUTHUNIX except that the uid/gid
19  * are always nobody (-2).  i.e. we do the same IP address checks for
20  * AUTHNULL as for AUTHUNIX, and that is done here.
21  */
22 
23 
24 struct unix_domain {
25 	struct auth_domain	h;
26 	int	addr_changes;
27 	/* other stuff later */
28 };
29 
30 extern struct auth_ops svcauth_unix;
31 
32 struct auth_domain *unix_domain_find(char *name)
33 {
34 	struct auth_domain *rv;
35 	struct unix_domain *new = NULL;
36 
37 	rv = auth_domain_lookup(name, NULL);
38 	while(1) {
39 		if (rv) {
40 			if (new && rv != &new->h)
41 				auth_domain_put(&new->h);
42 
43 			if (rv->flavour != &svcauth_unix) {
44 				auth_domain_put(rv);
45 				return NULL;
46 			}
47 			return rv;
48 		}
49 
50 		new = kmalloc(sizeof(*new), GFP_KERNEL);
51 		if (new == NULL)
52 			return NULL;
53 		kref_init(&new->h.ref);
54 		new->h.name = kstrdup(name, GFP_KERNEL);
55 		new->h.flavour = &svcauth_unix;
56 		new->addr_changes = 0;
57 		rv = auth_domain_lookup(name, &new->h);
58 	}
59 }
60 
61 static void svcauth_unix_domain_release(struct auth_domain *dom)
62 {
63 	struct unix_domain *ud = container_of(dom, struct unix_domain, h);
64 
65 	kfree(dom->name);
66 	kfree(ud);
67 }
68 
69 
70 /**************************************************
71  * cache for IP address to unix_domain
72  * as needed by AUTH_UNIX
73  */
74 #define	IP_HASHBITS	8
75 #define	IP_HASHMAX	(1<<IP_HASHBITS)
76 #define	IP_HASHMASK	(IP_HASHMAX-1)
77 
78 struct ip_map {
79 	struct cache_head	h;
80 	char			m_class[8]; /* e.g. "nfsd" */
81 	struct in_addr		m_addr;
82 	struct unix_domain	*m_client;
83 	int			m_add_change;
84 };
85 static struct cache_head	*ip_table[IP_HASHMAX];
86 
87 static void ip_map_put(struct kref *kref)
88 {
89 	struct cache_head *item = container_of(kref, struct cache_head, ref);
90 	struct ip_map *im = container_of(item, struct ip_map,h);
91 
92 	if (test_bit(CACHE_VALID, &item->flags) &&
93 	    !test_bit(CACHE_NEGATIVE, &item->flags))
94 		auth_domain_put(&im->m_client->h);
95 	kfree(im);
96 }
97 
98 #if IP_HASHBITS == 8
99 /* hash_long on a 64 bit machine is currently REALLY BAD for
100  * IP addresses in reverse-endian (i.e. on a little-endian machine).
101  * So use a trivial but reliable hash instead
102  */
103 static inline int hash_ip(unsigned long ip)
104 {
105 	int hash = ip ^ (ip>>16);
106 	return (hash ^ (hash>>8)) & 0xff;
107 }
108 #endif
109 static int ip_map_match(struct cache_head *corig, struct cache_head *cnew)
110 {
111 	struct ip_map *orig = container_of(corig, struct ip_map, h);
112 	struct ip_map *new = container_of(cnew, struct ip_map, h);
113 	return strcmp(orig->m_class, new->m_class) == 0
114 		&& orig->m_addr.s_addr == new->m_addr.s_addr;
115 }
116 static void ip_map_init(struct cache_head *cnew, struct cache_head *citem)
117 {
118 	struct ip_map *new = container_of(cnew, struct ip_map, h);
119 	struct ip_map *item = container_of(citem, struct ip_map, h);
120 
121 	strcpy(new->m_class, item->m_class);
122 	new->m_addr.s_addr = item->m_addr.s_addr;
123 }
124 static void update(struct cache_head *cnew, struct cache_head *citem)
125 {
126 	struct ip_map *new = container_of(cnew, struct ip_map, h);
127 	struct ip_map *item = container_of(citem, struct ip_map, h);
128 
129 	kref_get(&item->m_client->h.ref);
130 	new->m_client = item->m_client;
131 	new->m_add_change = item->m_add_change;
132 }
133 static struct cache_head *ip_map_alloc(void)
134 {
135 	struct ip_map *i = kmalloc(sizeof(*i), GFP_KERNEL);
136 	if (i)
137 		return &i->h;
138 	else
139 		return NULL;
140 }
141 
142 static void ip_map_request(struct cache_detail *cd,
143 				  struct cache_head *h,
144 				  char **bpp, int *blen)
145 {
146 	char text_addr[20];
147 	struct ip_map *im = container_of(h, struct ip_map, h);
148 	__u32 addr = im->m_addr.s_addr;
149 
150 	snprintf(text_addr, 20, "%u.%u.%u.%u",
151 		 ntohl(addr) >> 24 & 0xff,
152 		 ntohl(addr) >> 16 & 0xff,
153 		 ntohl(addr) >>  8 & 0xff,
154 		 ntohl(addr) >>  0 & 0xff);
155 
156 	qword_add(bpp, blen, im->m_class);
157 	qword_add(bpp, blen, text_addr);
158 	(*bpp)[-1] = '\n';
159 }
160 
161 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr);
162 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry);
163 
164 static int ip_map_parse(struct cache_detail *cd,
165 			  char *mesg, int mlen)
166 {
167 	/* class ipaddress [domainname] */
168 	/* should be safe just to use the start of the input buffer
169 	 * for scratch: */
170 	char *buf = mesg;
171 	int len;
172 	int b1,b2,b3,b4;
173 	char c;
174 	char class[8];
175 	struct in_addr addr;
176 	int err;
177 
178 	struct ip_map *ipmp;
179 	struct auth_domain *dom;
180 	time_t expiry;
181 
182 	if (mesg[mlen-1] != '\n')
183 		return -EINVAL;
184 	mesg[mlen-1] = 0;
185 
186 	/* class */
187 	len = qword_get(&mesg, class, sizeof(class));
188 	if (len <= 0) return -EINVAL;
189 
190 	/* ip address */
191 	len = qword_get(&mesg, buf, mlen);
192 	if (len <= 0) return -EINVAL;
193 
194 	if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
195 		return -EINVAL;
196 
197 	expiry = get_expiry(&mesg);
198 	if (expiry ==0)
199 		return -EINVAL;
200 
201 	/* domainname, or empty for NEGATIVE */
202 	len = qword_get(&mesg, buf, mlen);
203 	if (len < 0) return -EINVAL;
204 
205 	if (len) {
206 		dom = unix_domain_find(buf);
207 		if (dom == NULL)
208 			return -ENOENT;
209 	} else
210 		dom = NULL;
211 
212 	addr.s_addr =
213 		htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
214 
215 	ipmp = ip_map_lookup(class,addr);
216 	if (ipmp) {
217 		err = ip_map_update(ipmp,
218 			     container_of(dom, struct unix_domain, h),
219 			     expiry);
220 	} else
221 		err = -ENOMEM;
222 
223 	if (dom)
224 		auth_domain_put(dom);
225 
226 	cache_flush();
227 	return err;
228 }
229 
230 static int ip_map_show(struct seq_file *m,
231 		       struct cache_detail *cd,
232 		       struct cache_head *h)
233 {
234 	struct ip_map *im;
235 	struct in_addr addr;
236 	char *dom = "-no-domain-";
237 
238 	if (h == NULL) {
239 		seq_puts(m, "#class IP domain\n");
240 		return 0;
241 	}
242 	im = container_of(h, struct ip_map, h);
243 	/* class addr domain */
244 	addr = im->m_addr;
245 
246 	if (test_bit(CACHE_VALID, &h->flags) &&
247 	    !test_bit(CACHE_NEGATIVE, &h->flags))
248 		dom = im->m_client->h.name;
249 
250 	seq_printf(m, "%s %d.%d.%d.%d %s\n",
251 		   im->m_class,
252 		   htonl(addr.s_addr) >> 24 & 0xff,
253 		   htonl(addr.s_addr) >> 16 & 0xff,
254 		   htonl(addr.s_addr) >>  8 & 0xff,
255 		   htonl(addr.s_addr) >>  0 & 0xff,
256 		   dom
257 		   );
258 	return 0;
259 }
260 
261 
262 struct cache_detail ip_map_cache = {
263 	.owner		= THIS_MODULE,
264 	.hash_size	= IP_HASHMAX,
265 	.hash_table	= ip_table,
266 	.name		= "auth.unix.ip",
267 	.cache_put	= ip_map_put,
268 	.cache_request	= ip_map_request,
269 	.cache_parse	= ip_map_parse,
270 	.cache_show	= ip_map_show,
271 	.match		= ip_map_match,
272 	.init		= ip_map_init,
273 	.update		= update,
274 	.alloc		= ip_map_alloc,
275 };
276 
277 static struct ip_map *ip_map_lookup(char *class, struct in_addr addr)
278 {
279 	struct ip_map ip;
280 	struct cache_head *ch;
281 
282 	strcpy(ip.m_class, class);
283 	ip.m_addr = addr;
284 	ch = sunrpc_cache_lookup(&ip_map_cache, &ip.h,
285 				 hash_str(class, IP_HASHBITS) ^
286 				 hash_ip((unsigned long)addr.s_addr));
287 
288 	if (ch)
289 		return container_of(ch, struct ip_map, h);
290 	else
291 		return NULL;
292 }
293 
294 static int ip_map_update(struct ip_map *ipm, struct unix_domain *udom, time_t expiry)
295 {
296 	struct ip_map ip;
297 	struct cache_head *ch;
298 
299 	ip.m_client = udom;
300 	ip.h.flags = 0;
301 	if (!udom)
302 		set_bit(CACHE_NEGATIVE, &ip.h.flags);
303 	else {
304 		ip.m_add_change = udom->addr_changes;
305 		/* if this is from the legacy set_client system call,
306 		 * we need m_add_change to be one higher
307 		 */
308 		if (expiry == NEVER)
309 			ip.m_add_change++;
310 	}
311 	ip.h.expiry_time = expiry;
312 	ch = sunrpc_cache_update(&ip_map_cache,
313 				 &ip.h, &ipm->h,
314 				 hash_str(ipm->m_class, IP_HASHBITS) ^
315 				 hash_ip((unsigned long)ipm->m_addr.s_addr));
316 	if (!ch)
317 		return -ENOMEM;
318 	cache_put(ch, &ip_map_cache);
319 	return 0;
320 }
321 
322 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
323 {
324 	struct unix_domain *udom;
325 	struct ip_map *ipmp;
326 
327 	if (dom->flavour != &svcauth_unix)
328 		return -EINVAL;
329 	udom = container_of(dom, struct unix_domain, h);
330 	ipmp = ip_map_lookup("nfsd", addr);
331 
332 	if (ipmp)
333 		return ip_map_update(ipmp, udom, NEVER);
334 	else
335 		return -ENOMEM;
336 }
337 
338 int auth_unix_forget_old(struct auth_domain *dom)
339 {
340 	struct unix_domain *udom;
341 
342 	if (dom->flavour != &svcauth_unix)
343 		return -EINVAL;
344 	udom = container_of(dom, struct unix_domain, h);
345 	udom->addr_changes++;
346 	return 0;
347 }
348 
349 struct auth_domain *auth_unix_lookup(struct in_addr addr)
350 {
351 	struct ip_map key, *ipm;
352 	struct auth_domain *rv;
353 
354 	strcpy(key.m_class, "nfsd");
355 	key.m_addr = addr;
356 
357 	ipm = ip_map_lookup("nfsd", addr);
358 
359 	if (!ipm)
360 		return NULL;
361 	if (cache_check(&ip_map_cache, &ipm->h, NULL))
362 		return NULL;
363 
364 	if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
365 		if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
366 			auth_domain_put(&ipm->m_client->h);
367 		rv = NULL;
368 	} else {
369 		rv = &ipm->m_client->h;
370 		kref_get(&rv->ref);
371 	}
372 	cache_put(&ipm->h, &ip_map_cache);
373 	return rv;
374 }
375 
376 void svcauth_unix_purge(void)
377 {
378 	cache_purge(&ip_map_cache);
379 }
380 
381 static int
382 svcauth_unix_set_client(struct svc_rqst *rqstp)
383 {
384 	struct ip_map *ipm;
385 
386 	rqstp->rq_client = NULL;
387 	if (rqstp->rq_proc == 0)
388 		return SVC_OK;
389 
390 	ipm = ip_map_lookup(rqstp->rq_server->sv_program->pg_class,
391 			    rqstp->rq_addr.sin_addr);
392 
393 	if (ipm == NULL)
394 		return SVC_DENIED;
395 
396 	switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
397 		default:
398 			BUG();
399 		case -EAGAIN:
400 			return SVC_DROP;
401 		case -ENOENT:
402 			return SVC_DENIED;
403 		case 0:
404 			rqstp->rq_client = &ipm->m_client->h;
405 			kref_get(&rqstp->rq_client->ref);
406 			cache_put(&ipm->h, &ip_map_cache);
407 			break;
408 	}
409 	return SVC_OK;
410 }
411 
412 static int
413 svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp)
414 {
415 	struct kvec	*argv = &rqstp->rq_arg.head[0];
416 	struct kvec	*resv = &rqstp->rq_res.head[0];
417 	struct svc_cred	*cred = &rqstp->rq_cred;
418 
419 	cred->cr_group_info = NULL;
420 	rqstp->rq_client = NULL;
421 
422 	if (argv->iov_len < 3*4)
423 		return SVC_GARBAGE;
424 
425 	if (svc_getu32(argv) != 0) {
426 		dprintk("svc: bad null cred\n");
427 		*authp = rpc_autherr_badcred;
428 		return SVC_DENIED;
429 	}
430 	if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
431 		dprintk("svc: bad null verf\n");
432 		*authp = rpc_autherr_badverf;
433 		return SVC_DENIED;
434 	}
435 
436 	/* Signal that mapping to nobody uid/gid is required */
437 	cred->cr_uid = (uid_t) -1;
438 	cred->cr_gid = (gid_t) -1;
439 	cred->cr_group_info = groups_alloc(0);
440 	if (cred->cr_group_info == NULL)
441 		return SVC_DROP; /* kmalloc failure - client must retry */
442 
443 	/* Put NULL verifier */
444 	svc_putu32(resv, RPC_AUTH_NULL);
445 	svc_putu32(resv, 0);
446 
447 	return SVC_OK;
448 }
449 
450 static int
451 svcauth_null_release(struct svc_rqst *rqstp)
452 {
453 	if (rqstp->rq_client)
454 		auth_domain_put(rqstp->rq_client);
455 	rqstp->rq_client = NULL;
456 	if (rqstp->rq_cred.cr_group_info)
457 		put_group_info(rqstp->rq_cred.cr_group_info);
458 	rqstp->rq_cred.cr_group_info = NULL;
459 
460 	return 0; /* don't drop */
461 }
462 
463 
464 struct auth_ops svcauth_null = {
465 	.name		= "null",
466 	.owner		= THIS_MODULE,
467 	.flavour	= RPC_AUTH_NULL,
468 	.accept 	= svcauth_null_accept,
469 	.release	= svcauth_null_release,
470 	.set_client	= svcauth_unix_set_client,
471 };
472 
473 
474 static int
475 svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp)
476 {
477 	struct kvec	*argv = &rqstp->rq_arg.head[0];
478 	struct kvec	*resv = &rqstp->rq_res.head[0];
479 	struct svc_cred	*cred = &rqstp->rq_cred;
480 	u32		slen, i;
481 	int		len   = argv->iov_len;
482 
483 	cred->cr_group_info = NULL;
484 	rqstp->rq_client = NULL;
485 
486 	if ((len -= 3*4) < 0)
487 		return SVC_GARBAGE;
488 
489 	svc_getu32(argv);			/* length */
490 	svc_getu32(argv);			/* time stamp */
491 	slen = XDR_QUADLEN(ntohl(svc_getu32(argv)));	/* machname length */
492 	if (slen > 64 || (len -= (slen + 3)*4) < 0)
493 		goto badcred;
494 	argv->iov_base = (void*)((u32*)argv->iov_base + slen);	/* skip machname */
495 	argv->iov_len -= slen*4;
496 
497 	cred->cr_uid = ntohl(svc_getu32(argv));		/* uid */
498 	cred->cr_gid = ntohl(svc_getu32(argv));		/* gid */
499 	slen = ntohl(svc_getu32(argv));			/* gids length */
500 	if (slen > 16 || (len -= (slen + 2)*4) < 0)
501 		goto badcred;
502 	cred->cr_group_info = groups_alloc(slen);
503 	if (cred->cr_group_info == NULL)
504 		return SVC_DROP;
505 	for (i = 0; i < slen; i++)
506 		GROUP_AT(cred->cr_group_info, i) = ntohl(svc_getu32(argv));
507 
508 	if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
509 		*authp = rpc_autherr_badverf;
510 		return SVC_DENIED;
511 	}
512 
513 	/* Put NULL verifier */
514 	svc_putu32(resv, RPC_AUTH_NULL);
515 	svc_putu32(resv, 0);
516 
517 	return SVC_OK;
518 
519 badcred:
520 	*authp = rpc_autherr_badcred;
521 	return SVC_DENIED;
522 }
523 
524 static int
525 svcauth_unix_release(struct svc_rqst *rqstp)
526 {
527 	/* Verifier (such as it is) is already in place.
528 	 */
529 	if (rqstp->rq_client)
530 		auth_domain_put(rqstp->rq_client);
531 	rqstp->rq_client = NULL;
532 	if (rqstp->rq_cred.cr_group_info)
533 		put_group_info(rqstp->rq_cred.cr_group_info);
534 	rqstp->rq_cred.cr_group_info = NULL;
535 
536 	return 0;
537 }
538 
539 
540 struct auth_ops svcauth_unix = {
541 	.name		= "unix",
542 	.owner		= THIS_MODULE,
543 	.flavour	= RPC_AUTH_UNIX,
544 	.accept 	= svcauth_unix_accept,
545 	.release	= svcauth_unix_release,
546 	.domain_release	= svcauth_unix_domain_release,
547 	.set_client	= svcauth_unix_set_client,
548 };
549 
550