xref: /openbmc/linux/net/netlabel/netlabel_mgmt.c (revision 384740dc)
1 /*
2  * NetLabel Management Support
3  *
4  * This file defines the management functions for the NetLabel system.  The
5  * NetLabel system manages static and dynamic label mappings for network
6  * protocols such as CIPSO and RIPSO.
7  *
8  * Author: Paul Moore <paul.moore@hp.com>
9  *
10  */
11 
12 /*
13  * (c) Copyright Hewlett-Packard Development Company, L.P., 2006
14  *
15  * This program is free software;  you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY;  without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
23  * the GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program;  if not, write to the Free Software
27  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
28  *
29  */
30 
31 #include <linux/types.h>
32 #include <linux/socket.h>
33 #include <linux/string.h>
34 #include <linux/skbuff.h>
35 #include <net/sock.h>
36 #include <net/netlink.h>
37 #include <net/genetlink.h>
38 #include <net/netlabel.h>
39 #include <net/cipso_ipv4.h>
40 #include <asm/atomic.h>
41 
42 #include "netlabel_domainhash.h"
43 #include "netlabel_user.h"
44 #include "netlabel_mgmt.h"
45 
46 /* NetLabel configured protocol counter */
47 atomic_t netlabel_mgmt_protocount = ATOMIC_INIT(0);
48 
49 /* Argument struct for netlbl_domhsh_walk() */
50 struct netlbl_domhsh_walk_arg {
51 	struct netlink_callback *nl_cb;
52 	struct sk_buff *skb;
53 	u32 seq;
54 };
55 
56 /* NetLabel Generic NETLINK CIPSOv4 family */
57 static struct genl_family netlbl_mgmt_gnl_family = {
58 	.id = GENL_ID_GENERATE,
59 	.hdrsize = 0,
60 	.name = NETLBL_NLTYPE_MGMT_NAME,
61 	.version = NETLBL_PROTO_VERSION,
62 	.maxattr = NLBL_MGMT_A_MAX,
63 };
64 
65 /* NetLabel Netlink attribute policy */
66 static const struct nla_policy netlbl_mgmt_genl_policy[NLBL_MGMT_A_MAX + 1] = {
67 	[NLBL_MGMT_A_DOMAIN] = { .type = NLA_NUL_STRING },
68 	[NLBL_MGMT_A_PROTOCOL] = { .type = NLA_U32 },
69 	[NLBL_MGMT_A_VERSION] = { .type = NLA_U32 },
70 	[NLBL_MGMT_A_CV4DOI] = { .type = NLA_U32 },
71 };
72 
73 /*
74  * NetLabel Command Handlers
75  */
76 
77 /**
78  * netlbl_mgmt_add - Handle an ADD message
79  * @skb: the NETLINK buffer
80  * @info: the Generic NETLINK info block
81  *
82  * Description:
83  * Process a user generated ADD message and add the domains from the message
84  * to the hash table.  See netlabel.h for a description of the message format.
85  * Returns zero on success, negative values on failure.
86  *
87  */
88 static int netlbl_mgmt_add(struct sk_buff *skb, struct genl_info *info)
89 {
90 	int ret_val = -EINVAL;
91 	struct netlbl_dom_map *entry = NULL;
92 	size_t tmp_size;
93 	u32 tmp_val;
94 	struct netlbl_audit audit_info;
95 
96 	if (!info->attrs[NLBL_MGMT_A_DOMAIN] ||
97 	    !info->attrs[NLBL_MGMT_A_PROTOCOL])
98 		goto add_failure;
99 
100 	netlbl_netlink_auditinfo(skb, &audit_info);
101 
102 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
103 	if (entry == NULL) {
104 		ret_val = -ENOMEM;
105 		goto add_failure;
106 	}
107 	tmp_size = nla_len(info->attrs[NLBL_MGMT_A_DOMAIN]);
108 	entry->domain = kmalloc(tmp_size, GFP_KERNEL);
109 	if (entry->domain == NULL) {
110 		ret_val = -ENOMEM;
111 		goto add_failure;
112 	}
113 	entry->type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
114 	nla_strlcpy(entry->domain, info->attrs[NLBL_MGMT_A_DOMAIN], tmp_size);
115 
116 	switch (entry->type) {
117 	case NETLBL_NLTYPE_UNLABELED:
118 		ret_val = netlbl_domhsh_add(entry, &audit_info);
119 		break;
120 	case NETLBL_NLTYPE_CIPSOV4:
121 		if (!info->attrs[NLBL_MGMT_A_CV4DOI])
122 			goto add_failure;
123 
124 		tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
125 		/* We should be holding a rcu_read_lock() here while we hold
126 		 * the result but since the entry will always be deleted when
127 		 * the CIPSO DOI is deleted we aren't going to keep the
128 		 * lock. */
129 		rcu_read_lock();
130 		entry->type_def.cipsov4 = cipso_v4_doi_getdef(tmp_val);
131 		if (entry->type_def.cipsov4 == NULL) {
132 			rcu_read_unlock();
133 			goto add_failure;
134 		}
135 		ret_val = netlbl_domhsh_add(entry, &audit_info);
136 		rcu_read_unlock();
137 		break;
138 	default:
139 		goto add_failure;
140 	}
141 	if (ret_val != 0)
142 		goto add_failure;
143 
144 	return 0;
145 
146 add_failure:
147 	if (entry)
148 		kfree(entry->domain);
149 	kfree(entry);
150 	return ret_val;
151 }
152 
153 /**
154  * netlbl_mgmt_remove - Handle a REMOVE message
155  * @skb: the NETLINK buffer
156  * @info: the Generic NETLINK info block
157  *
158  * Description:
159  * Process a user generated REMOVE message and remove the specified domain
160  * mappings.  Returns zero on success, negative values on failure.
161  *
162  */
163 static int netlbl_mgmt_remove(struct sk_buff *skb, struct genl_info *info)
164 {
165 	char *domain;
166 	struct netlbl_audit audit_info;
167 
168 	if (!info->attrs[NLBL_MGMT_A_DOMAIN])
169 		return -EINVAL;
170 
171 	netlbl_netlink_auditinfo(skb, &audit_info);
172 
173 	domain = nla_data(info->attrs[NLBL_MGMT_A_DOMAIN]);
174 	return netlbl_domhsh_remove(domain, &audit_info);
175 }
176 
177 /**
178  * netlbl_mgmt_listall_cb - netlbl_domhsh_walk() callback for LISTALL
179  * @entry: the domain mapping hash table entry
180  * @arg: the netlbl_domhsh_walk_arg structure
181  *
182  * Description:
183  * This function is designed to be used as a callback to the
184  * netlbl_domhsh_walk() function for use in generating a response for a LISTALL
185  * message.  Returns the size of the message on success, negative values on
186  * failure.
187  *
188  */
189 static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
190 {
191 	int ret_val = -ENOMEM;
192 	struct netlbl_domhsh_walk_arg *cb_arg = arg;
193 	void *data;
194 
195 	data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
196 			   cb_arg->seq, &netlbl_mgmt_gnl_family,
197 			   NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
198 	if (data == NULL)
199 		goto listall_cb_failure;
200 
201 	ret_val = nla_put_string(cb_arg->skb,
202 				 NLBL_MGMT_A_DOMAIN,
203 				 entry->domain);
204 	if (ret_val != 0)
205 		goto listall_cb_failure;
206 	ret_val = nla_put_u32(cb_arg->skb, NLBL_MGMT_A_PROTOCOL, entry->type);
207 	if (ret_val != 0)
208 		goto listall_cb_failure;
209 	switch (entry->type) {
210 	case NETLBL_NLTYPE_CIPSOV4:
211 		ret_val = nla_put_u32(cb_arg->skb,
212 				      NLBL_MGMT_A_CV4DOI,
213 				      entry->type_def.cipsov4->doi);
214 		if (ret_val != 0)
215 			goto listall_cb_failure;
216 		break;
217 	}
218 
219 	cb_arg->seq++;
220 	return genlmsg_end(cb_arg->skb, data);
221 
222 listall_cb_failure:
223 	genlmsg_cancel(cb_arg->skb, data);
224 	return ret_val;
225 }
226 
227 /**
228  * netlbl_mgmt_listall - Handle a LISTALL message
229  * @skb: the NETLINK buffer
230  * @cb: the NETLINK callback
231  *
232  * Description:
233  * Process a user generated LISTALL message and dumps the domain hash table in
234  * a form suitable for use in a kernel generated LISTALL message.  Returns zero
235  * on success, negative values on failure.
236  *
237  */
238 static int netlbl_mgmt_listall(struct sk_buff *skb,
239 			       struct netlink_callback *cb)
240 {
241 	struct netlbl_domhsh_walk_arg cb_arg;
242 	u32 skip_bkt = cb->args[0];
243 	u32 skip_chain = cb->args[1];
244 
245 	cb_arg.nl_cb = cb;
246 	cb_arg.skb = skb;
247 	cb_arg.seq = cb->nlh->nlmsg_seq;
248 
249 	netlbl_domhsh_walk(&skip_bkt,
250 			   &skip_chain,
251 			   netlbl_mgmt_listall_cb,
252 			   &cb_arg);
253 
254 	cb->args[0] = skip_bkt;
255 	cb->args[1] = skip_chain;
256 	return skb->len;
257 }
258 
259 /**
260  * netlbl_mgmt_adddef - Handle an ADDDEF message
261  * @skb: the NETLINK buffer
262  * @info: the Generic NETLINK info block
263  *
264  * Description:
265  * Process a user generated ADDDEF message and respond accordingly.  Returns
266  * zero on success, negative values on failure.
267  *
268  */
269 static int netlbl_mgmt_adddef(struct sk_buff *skb, struct genl_info *info)
270 {
271 	int ret_val = -EINVAL;
272 	struct netlbl_dom_map *entry = NULL;
273 	u32 tmp_val;
274 	struct netlbl_audit audit_info;
275 
276 	if (!info->attrs[NLBL_MGMT_A_PROTOCOL])
277 		goto adddef_failure;
278 
279 	netlbl_netlink_auditinfo(skb, &audit_info);
280 
281 	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
282 	if (entry == NULL) {
283 		ret_val = -ENOMEM;
284 		goto adddef_failure;
285 	}
286 	entry->type = nla_get_u32(info->attrs[NLBL_MGMT_A_PROTOCOL]);
287 
288 	switch (entry->type) {
289 	case NETLBL_NLTYPE_UNLABELED:
290 		ret_val = netlbl_domhsh_add_default(entry, &audit_info);
291 		break;
292 	case NETLBL_NLTYPE_CIPSOV4:
293 		if (!info->attrs[NLBL_MGMT_A_CV4DOI])
294 			goto adddef_failure;
295 
296 		tmp_val = nla_get_u32(info->attrs[NLBL_MGMT_A_CV4DOI]);
297 		/* We should be holding a rcu_read_lock() here while we hold
298 		 * the result but since the entry will always be deleted when
299 		 * the CIPSO DOI is deleted we aren't going to keep the
300 		 * lock. */
301 		rcu_read_lock();
302 		entry->type_def.cipsov4 = cipso_v4_doi_getdef(tmp_val);
303 		if (entry->type_def.cipsov4 == NULL) {
304 			rcu_read_unlock();
305 			goto adddef_failure;
306 		}
307 		ret_val = netlbl_domhsh_add_default(entry, &audit_info);
308 		rcu_read_unlock();
309 		break;
310 	default:
311 		goto adddef_failure;
312 	}
313 	if (ret_val != 0)
314 		goto adddef_failure;
315 
316 	return 0;
317 
318 adddef_failure:
319 	kfree(entry);
320 	return ret_val;
321 }
322 
323 /**
324  * netlbl_mgmt_removedef - Handle a REMOVEDEF message
325  * @skb: the NETLINK buffer
326  * @info: the Generic NETLINK info block
327  *
328  * Description:
329  * Process a user generated REMOVEDEF message and remove the default domain
330  * mapping.  Returns zero on success, negative values on failure.
331  *
332  */
333 static int netlbl_mgmt_removedef(struct sk_buff *skb, struct genl_info *info)
334 {
335 	struct netlbl_audit audit_info;
336 
337 	netlbl_netlink_auditinfo(skb, &audit_info);
338 
339 	return netlbl_domhsh_remove_default(&audit_info);
340 }
341 
342 /**
343  * netlbl_mgmt_listdef - Handle a LISTDEF message
344  * @skb: the NETLINK buffer
345  * @info: the Generic NETLINK info block
346  *
347  * Description:
348  * Process a user generated LISTDEF message and dumps the default domain
349  * mapping in a form suitable for use in a kernel generated LISTDEF message.
350  * Returns zero on success, negative values on failure.
351  *
352  */
353 static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
354 {
355 	int ret_val = -ENOMEM;
356 	struct sk_buff *ans_skb = NULL;
357 	void *data;
358 	struct netlbl_dom_map *entry;
359 
360 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
361 	if (ans_skb == NULL)
362 		return -ENOMEM;
363 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
364 				 0, NLBL_MGMT_C_LISTDEF);
365 	if (data == NULL)
366 		goto listdef_failure;
367 
368 	rcu_read_lock();
369 	entry = netlbl_domhsh_getentry(NULL);
370 	if (entry == NULL) {
371 		ret_val = -ENOENT;
372 		goto listdef_failure_lock;
373 	}
374 	ret_val = nla_put_u32(ans_skb, NLBL_MGMT_A_PROTOCOL, entry->type);
375 	if (ret_val != 0)
376 		goto listdef_failure_lock;
377 	switch (entry->type) {
378 	case NETLBL_NLTYPE_CIPSOV4:
379 		ret_val = nla_put_u32(ans_skb,
380 				      NLBL_MGMT_A_CV4DOI,
381 				      entry->type_def.cipsov4->doi);
382 		if (ret_val != 0)
383 			goto listdef_failure_lock;
384 		break;
385 	}
386 	rcu_read_unlock();
387 
388 	genlmsg_end(ans_skb, data);
389 	return genlmsg_reply(ans_skb, info);
390 
391 listdef_failure_lock:
392 	rcu_read_unlock();
393 listdef_failure:
394 	kfree_skb(ans_skb);
395 	return ret_val;
396 }
397 
398 /**
399  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
400  * @skb: the skb to write to
401  * @seq: the NETLINK sequence number
402  * @cb: the NETLINK callback
403  * @protocol: the NetLabel protocol to use in the message
404  *
405  * Description:
406  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
407  * answer a application's PROTOCOLS message.  Returns the size of the message
408  * on success, negative values on failure.
409  *
410  */
411 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
412 				    struct netlink_callback *cb,
413 				    u32 protocol)
414 {
415 	int ret_val = -ENOMEM;
416 	void *data;
417 
418 	data = genlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
419 			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
420 			   NLBL_MGMT_C_PROTOCOLS);
421 	if (data == NULL)
422 		goto protocols_cb_failure;
423 
424 	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
425 	if (ret_val != 0)
426 		goto protocols_cb_failure;
427 
428 	return genlmsg_end(skb, data);
429 
430 protocols_cb_failure:
431 	genlmsg_cancel(skb, data);
432 	return ret_val;
433 }
434 
435 /**
436  * netlbl_mgmt_protocols - Handle a PROTOCOLS message
437  * @skb: the NETLINK buffer
438  * @cb: the NETLINK callback
439  *
440  * Description:
441  * Process a user generated PROTOCOLS message and respond accordingly.
442  *
443  */
444 static int netlbl_mgmt_protocols(struct sk_buff *skb,
445 				 struct netlink_callback *cb)
446 {
447 	u32 protos_sent = cb->args[0];
448 
449 	if (protos_sent == 0) {
450 		if (netlbl_mgmt_protocols_cb(skb,
451 					     cb,
452 					     NETLBL_NLTYPE_UNLABELED) < 0)
453 			goto protocols_return;
454 		protos_sent++;
455 	}
456 	if (protos_sent == 1) {
457 		if (netlbl_mgmt_protocols_cb(skb,
458 					     cb,
459 					     NETLBL_NLTYPE_CIPSOV4) < 0)
460 			goto protocols_return;
461 		protos_sent++;
462 	}
463 
464 protocols_return:
465 	cb->args[0] = protos_sent;
466 	return skb->len;
467 }
468 
469 /**
470  * netlbl_mgmt_version - Handle a VERSION message
471  * @skb: the NETLINK buffer
472  * @info: the Generic NETLINK info block
473  *
474  * Description:
475  * Process a user generated VERSION message and respond accordingly.  Returns
476  * zero on success, negative values on failure.
477  *
478  */
479 static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
480 {
481 	int ret_val = -ENOMEM;
482 	struct sk_buff *ans_skb = NULL;
483 	void *data;
484 
485 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
486 	if (ans_skb == NULL)
487 		return -ENOMEM;
488 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
489 				 0, NLBL_MGMT_C_VERSION);
490 	if (data == NULL)
491 		goto version_failure;
492 
493 	ret_val = nla_put_u32(ans_skb,
494 			      NLBL_MGMT_A_VERSION,
495 			      NETLBL_PROTO_VERSION);
496 	if (ret_val != 0)
497 		goto version_failure;
498 
499 	genlmsg_end(ans_skb, data);
500 	return genlmsg_reply(ans_skb, info);
501 
502 version_failure:
503 	kfree_skb(ans_skb);
504 	return ret_val;
505 }
506 
507 
508 /*
509  * NetLabel Generic NETLINK Command Definitions
510  */
511 
512 static struct genl_ops netlbl_mgmt_genl_ops[] = {
513 	{
514 	.cmd = NLBL_MGMT_C_ADD,
515 	.flags = GENL_ADMIN_PERM,
516 	.policy = netlbl_mgmt_genl_policy,
517 	.doit = netlbl_mgmt_add,
518 	.dumpit = NULL,
519 	},
520 	{
521 	.cmd = NLBL_MGMT_C_REMOVE,
522 	.flags = GENL_ADMIN_PERM,
523 	.policy = netlbl_mgmt_genl_policy,
524 	.doit = netlbl_mgmt_remove,
525 	.dumpit = NULL,
526 	},
527 	{
528 	.cmd = NLBL_MGMT_C_LISTALL,
529 	.flags = 0,
530 	.policy = netlbl_mgmt_genl_policy,
531 	.doit = NULL,
532 	.dumpit = netlbl_mgmt_listall,
533 	},
534 	{
535 	.cmd = NLBL_MGMT_C_ADDDEF,
536 	.flags = GENL_ADMIN_PERM,
537 	.policy = netlbl_mgmt_genl_policy,
538 	.doit = netlbl_mgmt_adddef,
539 	.dumpit = NULL,
540 	},
541 	{
542 	.cmd = NLBL_MGMT_C_REMOVEDEF,
543 	.flags = GENL_ADMIN_PERM,
544 	.policy = netlbl_mgmt_genl_policy,
545 	.doit = netlbl_mgmt_removedef,
546 	.dumpit = NULL,
547 	},
548 	{
549 	.cmd = NLBL_MGMT_C_LISTDEF,
550 	.flags = 0,
551 	.policy = netlbl_mgmt_genl_policy,
552 	.doit = netlbl_mgmt_listdef,
553 	.dumpit = NULL,
554 	},
555 	{
556 	.cmd = NLBL_MGMT_C_PROTOCOLS,
557 	.flags = 0,
558 	.policy = netlbl_mgmt_genl_policy,
559 	.doit = NULL,
560 	.dumpit = netlbl_mgmt_protocols,
561 	},
562 	{
563 	.cmd = NLBL_MGMT_C_VERSION,
564 	.flags = 0,
565 	.policy = netlbl_mgmt_genl_policy,
566 	.doit = netlbl_mgmt_version,
567 	.dumpit = NULL,
568 	},
569 };
570 
571 /*
572  * NetLabel Generic NETLINK Protocol Functions
573  */
574 
575 /**
576  * netlbl_mgmt_genl_init - Register the NetLabel management component
577  *
578  * Description:
579  * Register the NetLabel management component with the Generic NETLINK
580  * mechanism.  Returns zero on success, negative values on failure.
581  *
582  */
583 int __init netlbl_mgmt_genl_init(void)
584 {
585 	int ret_val, i;
586 
587 	ret_val = genl_register_family(&netlbl_mgmt_gnl_family);
588 	if (ret_val != 0)
589 		return ret_val;
590 
591 	for (i = 0; i < ARRAY_SIZE(netlbl_mgmt_genl_ops); i++) {
592 		ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
593 				&netlbl_mgmt_genl_ops[i]);
594 		if (ret_val != 0)
595 			return ret_val;
596 	}
597 
598 	return 0;
599 }
600