xref: /linux/net/sunrpc/svcauth_unix.c (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
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 struct auth_domain *unix_domain_find(char *name)
31 {
32 	struct auth_domain *rv, ud;
33 	struct unix_domain *new;
34 
35 	ud.name = name;
36 
37 	rv = auth_domain_lookup(&ud, 0);
38 
39  foundit:
40 	if (rv && rv->flavour != RPC_AUTH_UNIX) {
41 		auth_domain_put(rv);
42 		return NULL;
43 	}
44 	if (rv)
45 		return rv;
46 
47 	new = kmalloc(sizeof(*new), GFP_KERNEL);
48 	if (new == NULL)
49 		return NULL;
50 	cache_init(&new->h.h);
51 	new->h.name = kstrdup(name, GFP_KERNEL);
52 	new->h.flavour = RPC_AUTH_UNIX;
53 	new->addr_changes = 0;
54 	new->h.h.expiry_time = NEVER;
55 
56 	rv = auth_domain_lookup(&new->h, 2);
57 	if (rv == &new->h) {
58 		if (atomic_dec_and_test(&new->h.h.refcnt)) BUG();
59 	} else {
60 		auth_domain_put(&new->h);
61 		goto foundit;
62 	}
63 
64 	return rv;
65 }
66 
67 static void svcauth_unix_domain_release(struct auth_domain *dom)
68 {
69 	struct unix_domain *ud = container_of(dom, struct unix_domain, h);
70 
71 	kfree(dom->name);
72 	kfree(ud);
73 }
74 
75 
76 /**************************************************
77  * cache for IP address to unix_domain
78  * as needed by AUTH_UNIX
79  */
80 #define	IP_HASHBITS	8
81 #define	IP_HASHMAX	(1<<IP_HASHBITS)
82 #define	IP_HASHMASK	(IP_HASHMAX-1)
83 
84 struct ip_map {
85 	struct cache_head	h;
86 	char			m_class[8]; /* e.g. "nfsd" */
87 	struct in_addr		m_addr;
88 	struct unix_domain	*m_client;
89 	int			m_add_change;
90 };
91 static struct cache_head	*ip_table[IP_HASHMAX];
92 
93 static void ip_map_put(struct cache_head *item, struct cache_detail *cd)
94 {
95 	struct ip_map *im = container_of(item, struct ip_map,h);
96 	if (cache_put(item, cd)) {
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 
104 static inline int ip_map_hash(struct ip_map *item)
105 {
106 	return hash_str(item->m_class, IP_HASHBITS) ^
107 		hash_long((unsigned long)item->m_addr.s_addr, IP_HASHBITS);
108 }
109 static inline int ip_map_match(struct ip_map *item, struct ip_map *tmp)
110 {
111 	return strcmp(tmp->m_class, item->m_class) == 0
112 		&& tmp->m_addr.s_addr == item->m_addr.s_addr;
113 }
114 static inline void ip_map_init(struct ip_map *new, struct ip_map *item)
115 {
116 	strcpy(new->m_class, item->m_class);
117 	new->m_addr.s_addr = item->m_addr.s_addr;
118 }
119 static inline void ip_map_update(struct ip_map *new, struct ip_map *item)
120 {
121 	cache_get(&item->m_client->h.h);
122 	new->m_client = item->m_client;
123 	new->m_add_change = item->m_add_change;
124 }
125 
126 static void ip_map_request(struct cache_detail *cd,
127 				  struct cache_head *h,
128 				  char **bpp, int *blen)
129 {
130 	char text_addr[20];
131 	struct ip_map *im = container_of(h, struct ip_map, h);
132 	__u32 addr = im->m_addr.s_addr;
133 
134 	snprintf(text_addr, 20, "%u.%u.%u.%u",
135 		 ntohl(addr) >> 24 & 0xff,
136 		 ntohl(addr) >> 16 & 0xff,
137 		 ntohl(addr) >>  8 & 0xff,
138 		 ntohl(addr) >>  0 & 0xff);
139 
140 	qword_add(bpp, blen, im->m_class);
141 	qword_add(bpp, blen, text_addr);
142 	(*bpp)[-1] = '\n';
143 }
144 
145 static struct ip_map *ip_map_lookup(struct ip_map *, int);
146 
147 static int ip_map_parse(struct cache_detail *cd,
148 			  char *mesg, int mlen)
149 {
150 	/* class ipaddress [domainname] */
151 	/* should be safe just to use the start of the input buffer
152 	 * for scratch: */
153 	char *buf = mesg;
154 	int len;
155 	int b1,b2,b3,b4;
156 	char c;
157 	struct ip_map ipm, *ipmp;
158 	struct auth_domain *dom;
159 	time_t expiry;
160 
161 	if (mesg[mlen-1] != '\n')
162 		return -EINVAL;
163 	mesg[mlen-1] = 0;
164 
165 	/* class */
166 	len = qword_get(&mesg, ipm.m_class, sizeof(ipm.m_class));
167 	if (len <= 0) return -EINVAL;
168 
169 	/* ip address */
170 	len = qword_get(&mesg, buf, mlen);
171 	if (len <= 0) return -EINVAL;
172 
173 	if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
174 		return -EINVAL;
175 
176 	expiry = get_expiry(&mesg);
177 	if (expiry ==0)
178 		return -EINVAL;
179 
180 	/* domainname, or empty for NEGATIVE */
181 	len = qword_get(&mesg, buf, mlen);
182 	if (len < 0) return -EINVAL;
183 
184 	if (len) {
185 		dom = unix_domain_find(buf);
186 		if (dom == NULL)
187 			return -ENOENT;
188 	} else
189 		dom = NULL;
190 
191 	ipm.m_addr.s_addr =
192 		htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
193 	ipm.h.flags = 0;
194 	if (dom) {
195 		ipm.m_client = container_of(dom, struct unix_domain, h);
196 		ipm.m_add_change = ipm.m_client->addr_changes;
197 	} else
198 		set_bit(CACHE_NEGATIVE, &ipm.h.flags);
199 	ipm.h.expiry_time = expiry;
200 
201 	ipmp = ip_map_lookup(&ipm, 1);
202 	if (ipmp)
203 		ip_map_put(&ipmp->h, &ip_map_cache);
204 	if (dom)
205 		auth_domain_put(dom);
206 	if (!ipmp)
207 		return -ENOMEM;
208 	cache_flush();
209 	return 0;
210 }
211 
212 static int ip_map_show(struct seq_file *m,
213 		       struct cache_detail *cd,
214 		       struct cache_head *h)
215 {
216 	struct ip_map *im;
217 	struct in_addr addr;
218 	char *dom = "-no-domain-";
219 
220 	if (h == NULL) {
221 		seq_puts(m, "#class IP domain\n");
222 		return 0;
223 	}
224 	im = container_of(h, struct ip_map, h);
225 	/* class addr domain */
226 	addr = im->m_addr;
227 
228 	if (test_bit(CACHE_VALID, &h->flags) &&
229 	    !test_bit(CACHE_NEGATIVE, &h->flags))
230 		dom = im->m_client->h.name;
231 
232 	seq_printf(m, "%s %d.%d.%d.%d %s\n",
233 		   im->m_class,
234 		   htonl(addr.s_addr) >> 24 & 0xff,
235 		   htonl(addr.s_addr) >> 16 & 0xff,
236 		   htonl(addr.s_addr) >>  8 & 0xff,
237 		   htonl(addr.s_addr) >>  0 & 0xff,
238 		   dom
239 		   );
240 	return 0;
241 }
242 
243 
244 struct cache_detail ip_map_cache = {
245 	.hash_size	= IP_HASHMAX,
246 	.hash_table	= ip_table,
247 	.name		= "auth.unix.ip",
248 	.cache_put	= ip_map_put,
249 	.cache_request	= ip_map_request,
250 	.cache_parse	= ip_map_parse,
251 	.cache_show	= ip_map_show,
252 };
253 
254 static DefineSimpleCacheLookup(ip_map, 0)
255 
256 
257 int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
258 {
259 	struct unix_domain *udom;
260 	struct ip_map ip, *ipmp;
261 
262 	if (dom->flavour != RPC_AUTH_UNIX)
263 		return -EINVAL;
264 	udom = container_of(dom, struct unix_domain, h);
265 	strcpy(ip.m_class, "nfsd");
266 	ip.m_addr = addr;
267 	ip.m_client = udom;
268 	ip.m_add_change = udom->addr_changes+1;
269 	ip.h.flags = 0;
270 	ip.h.expiry_time = NEVER;
271 
272 	ipmp = ip_map_lookup(&ip, 1);
273 
274 	if (ipmp) {
275 		ip_map_put(&ipmp->h, &ip_map_cache);
276 		return 0;
277 	} else
278 		return -ENOMEM;
279 }
280 
281 int auth_unix_forget_old(struct auth_domain *dom)
282 {
283 	struct unix_domain *udom;
284 
285 	if (dom->flavour != RPC_AUTH_UNIX)
286 		return -EINVAL;
287 	udom = container_of(dom, struct unix_domain, h);
288 	udom->addr_changes++;
289 	return 0;
290 }
291 
292 struct auth_domain *auth_unix_lookup(struct in_addr addr)
293 {
294 	struct ip_map key, *ipm;
295 	struct auth_domain *rv;
296 
297 	strcpy(key.m_class, "nfsd");
298 	key.m_addr = addr;
299 
300 	ipm = ip_map_lookup(&key, 0);
301 
302 	if (!ipm)
303 		return NULL;
304 	if (cache_check(&ip_map_cache, &ipm->h, NULL))
305 		return NULL;
306 
307 	if ((ipm->m_client->addr_changes - ipm->m_add_change) >0) {
308 		if (test_and_set_bit(CACHE_NEGATIVE, &ipm->h.flags) == 0)
309 			auth_domain_put(&ipm->m_client->h);
310 		rv = NULL;
311 	} else {
312 		rv = &ipm->m_client->h;
313 		cache_get(&rv->h);
314 	}
315 	ip_map_put(&ipm->h, &ip_map_cache);
316 	return rv;
317 }
318 
319 void svcauth_unix_purge(void)
320 {
321 	cache_purge(&ip_map_cache);
322 	cache_purge(&auth_domain_cache);
323 }
324 
325 static int
326 svcauth_unix_set_client(struct svc_rqst *rqstp)
327 {
328 	struct ip_map key, *ipm;
329 
330 	rqstp->rq_client = NULL;
331 	if (rqstp->rq_proc == 0)
332 		return SVC_OK;
333 
334 	strcpy(key.m_class, rqstp->rq_server->sv_program->pg_class);
335 	key.m_addr = rqstp->rq_addr.sin_addr;
336 
337 	ipm = ip_map_lookup(&key, 0);
338 
339 	if (ipm == NULL)
340 		return SVC_DENIED;
341 
342 	switch (cache_check(&ip_map_cache, &ipm->h, &rqstp->rq_chandle)) {
343 		default:
344 			BUG();
345 		case -EAGAIN:
346 			return SVC_DROP;
347 		case -ENOENT:
348 			return SVC_DENIED;
349 		case 0:
350 			rqstp->rq_client = &ipm->m_client->h;
351 			cache_get(&rqstp->rq_client->h);
352 			ip_map_put(&ipm->h, &ip_map_cache);
353 			break;
354 	}
355 	return SVC_OK;
356 }
357 
358 static int
359 svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp)
360 {
361 	struct kvec	*argv = &rqstp->rq_arg.head[0];
362 	struct kvec	*resv = &rqstp->rq_res.head[0];
363 	struct svc_cred	*cred = &rqstp->rq_cred;
364 
365 	cred->cr_group_info = NULL;
366 	rqstp->rq_client = NULL;
367 
368 	if (argv->iov_len < 3*4)
369 		return SVC_GARBAGE;
370 
371 	if (svc_getu32(argv) != 0) {
372 		dprintk("svc: bad null cred\n");
373 		*authp = rpc_autherr_badcred;
374 		return SVC_DENIED;
375 	}
376 	if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
377 		dprintk("svc: bad null verf\n");
378 		*authp = rpc_autherr_badverf;
379 		return SVC_DENIED;
380 	}
381 
382 	/* Signal that mapping to nobody uid/gid is required */
383 	cred->cr_uid = (uid_t) -1;
384 	cred->cr_gid = (gid_t) -1;
385 	cred->cr_group_info = groups_alloc(0);
386 	if (cred->cr_group_info == NULL)
387 		return SVC_DROP; /* kmalloc failure - client must retry */
388 
389 	/* Put NULL verifier */
390 	svc_putu32(resv, RPC_AUTH_NULL);
391 	svc_putu32(resv, 0);
392 
393 	return SVC_OK;
394 }
395 
396 static int
397 svcauth_null_release(struct svc_rqst *rqstp)
398 {
399 	if (rqstp->rq_client)
400 		auth_domain_put(rqstp->rq_client);
401 	rqstp->rq_client = NULL;
402 	if (rqstp->rq_cred.cr_group_info)
403 		put_group_info(rqstp->rq_cred.cr_group_info);
404 	rqstp->rq_cred.cr_group_info = NULL;
405 
406 	return 0; /* don't drop */
407 }
408 
409 
410 struct auth_ops svcauth_null = {
411 	.name		= "null",
412 	.owner		= THIS_MODULE,
413 	.flavour	= RPC_AUTH_NULL,
414 	.accept 	= svcauth_null_accept,
415 	.release	= svcauth_null_release,
416 	.set_client	= svcauth_unix_set_client,
417 };
418 
419 
420 static int
421 svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp)
422 {
423 	struct kvec	*argv = &rqstp->rq_arg.head[0];
424 	struct kvec	*resv = &rqstp->rq_res.head[0];
425 	struct svc_cred	*cred = &rqstp->rq_cred;
426 	u32		slen, i;
427 	int		len   = argv->iov_len;
428 
429 	cred->cr_group_info = NULL;
430 	rqstp->rq_client = NULL;
431 
432 	if ((len -= 3*4) < 0)
433 		return SVC_GARBAGE;
434 
435 	svc_getu32(argv);			/* length */
436 	svc_getu32(argv);			/* time stamp */
437 	slen = XDR_QUADLEN(ntohl(svc_getu32(argv)));	/* machname length */
438 	if (slen > 64 || (len -= (slen + 3)*4) < 0)
439 		goto badcred;
440 	argv->iov_base = (void*)((u32*)argv->iov_base + slen);	/* skip machname */
441 	argv->iov_len -= slen*4;
442 
443 	cred->cr_uid = ntohl(svc_getu32(argv));		/* uid */
444 	cred->cr_gid = ntohl(svc_getu32(argv));		/* gid */
445 	slen = ntohl(svc_getu32(argv));			/* gids length */
446 	if (slen > 16 || (len -= (slen + 2)*4) < 0)
447 		goto badcred;
448 	cred->cr_group_info = groups_alloc(slen);
449 	if (cred->cr_group_info == NULL)
450 		return SVC_DROP;
451 	for (i = 0; i < slen; i++)
452 		GROUP_AT(cred->cr_group_info, i) = ntohl(svc_getu32(argv));
453 
454 	if (svc_getu32(argv) != RPC_AUTH_NULL || svc_getu32(argv) != 0) {
455 		*authp = rpc_autherr_badverf;
456 		return SVC_DENIED;
457 	}
458 
459 	/* Put NULL verifier */
460 	svc_putu32(resv, RPC_AUTH_NULL);
461 	svc_putu32(resv, 0);
462 
463 	return SVC_OK;
464 
465 badcred:
466 	*authp = rpc_autherr_badcred;
467 	return SVC_DENIED;
468 }
469 
470 static int
471 svcauth_unix_release(struct svc_rqst *rqstp)
472 {
473 	/* Verifier (such as it is) is already in place.
474 	 */
475 	if (rqstp->rq_client)
476 		auth_domain_put(rqstp->rq_client);
477 	rqstp->rq_client = NULL;
478 	if (rqstp->rq_cred.cr_group_info)
479 		put_group_info(rqstp->rq_cred.cr_group_info);
480 	rqstp->rq_cred.cr_group_info = NULL;
481 
482 	return 0;
483 }
484 
485 
486 struct auth_ops svcauth_unix = {
487 	.name		= "unix",
488 	.owner		= THIS_MODULE,
489 	.flavour	= RPC_AUTH_UNIX,
490 	.accept 	= svcauth_unix_accept,
491 	.release	= svcauth_unix_release,
492 	.domain_release	= svcauth_unix_domain_release,
493 	.set_client	= svcauth_unix_set_client,
494 };
495 
496