xref: /openbmc/linux/net/netlabel/netlabel_mgmt.c (revision 643d1f7f)
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 
390 	ret_val = genlmsg_reply(ans_skb, info);
391 	if (ret_val != 0)
392 		goto listdef_failure;
393 	return 0;
394 
395 listdef_failure_lock:
396 	rcu_read_unlock();
397 listdef_failure:
398 	kfree_skb(ans_skb);
399 	return ret_val;
400 }
401 
402 /**
403  * netlbl_mgmt_protocols_cb - Write an individual PROTOCOL message response
404  * @skb: the skb to write to
405  * @seq: the NETLINK sequence number
406  * @cb: the NETLINK callback
407  * @protocol: the NetLabel protocol to use in the message
408  *
409  * Description:
410  * This function is to be used in conjunction with netlbl_mgmt_protocols() to
411  * answer a application's PROTOCOLS message.  Returns the size of the message
412  * on success, negative values on failure.
413  *
414  */
415 static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
416 				    struct netlink_callback *cb,
417 				    u32 protocol)
418 {
419 	int ret_val = -ENOMEM;
420 	void *data;
421 
422 	data = genlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
423 			   &netlbl_mgmt_gnl_family, NLM_F_MULTI,
424 			   NLBL_MGMT_C_PROTOCOLS);
425 	if (data == NULL)
426 		goto protocols_cb_failure;
427 
428 	ret_val = nla_put_u32(skb, NLBL_MGMT_A_PROTOCOL, protocol);
429 	if (ret_val != 0)
430 		goto protocols_cb_failure;
431 
432 	return genlmsg_end(skb, data);
433 
434 protocols_cb_failure:
435 	genlmsg_cancel(skb, data);
436 	return ret_val;
437 }
438 
439 /**
440  * netlbl_mgmt_protocols - Handle a PROTOCOLS message
441  * @skb: the NETLINK buffer
442  * @cb: the NETLINK callback
443  *
444  * Description:
445  * Process a user generated PROTOCOLS message and respond accordingly.
446  *
447  */
448 static int netlbl_mgmt_protocols(struct sk_buff *skb,
449 				 struct netlink_callback *cb)
450 {
451 	u32 protos_sent = cb->args[0];
452 
453 	if (protos_sent == 0) {
454 		if (netlbl_mgmt_protocols_cb(skb,
455 					     cb,
456 					     NETLBL_NLTYPE_UNLABELED) < 0)
457 			goto protocols_return;
458 		protos_sent++;
459 	}
460 	if (protos_sent == 1) {
461 		if (netlbl_mgmt_protocols_cb(skb,
462 					     cb,
463 					     NETLBL_NLTYPE_CIPSOV4) < 0)
464 			goto protocols_return;
465 		protos_sent++;
466 	}
467 
468 protocols_return:
469 	cb->args[0] = protos_sent;
470 	return skb->len;
471 }
472 
473 /**
474  * netlbl_mgmt_version - Handle a VERSION message
475  * @skb: the NETLINK buffer
476  * @info: the Generic NETLINK info block
477  *
478  * Description:
479  * Process a user generated VERSION message and respond accordingly.  Returns
480  * zero on success, negative values on failure.
481  *
482  */
483 static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
484 {
485 	int ret_val = -ENOMEM;
486 	struct sk_buff *ans_skb = NULL;
487 	void *data;
488 
489 	ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
490 	if (ans_skb == NULL)
491 		return -ENOMEM;
492 	data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
493 				 0, NLBL_MGMT_C_VERSION);
494 	if (data == NULL)
495 		goto version_failure;
496 
497 	ret_val = nla_put_u32(ans_skb,
498 			      NLBL_MGMT_A_VERSION,
499 			      NETLBL_PROTO_VERSION);
500 	if (ret_val != 0)
501 		goto version_failure;
502 
503 	genlmsg_end(ans_skb, data);
504 
505 	ret_val = genlmsg_reply(ans_skb, info);
506 	if (ret_val != 0)
507 		goto version_failure;
508 	return 0;
509 
510 version_failure:
511 	kfree_skb(ans_skb);
512 	return ret_val;
513 }
514 
515 
516 /*
517  * NetLabel Generic NETLINK Command Definitions
518  */
519 
520 static struct genl_ops netlbl_mgmt_genl_c_add = {
521 	.cmd = NLBL_MGMT_C_ADD,
522 	.flags = GENL_ADMIN_PERM,
523 	.policy = netlbl_mgmt_genl_policy,
524 	.doit = netlbl_mgmt_add,
525 	.dumpit = NULL,
526 };
527 
528 static struct genl_ops netlbl_mgmt_genl_c_remove = {
529 	.cmd = NLBL_MGMT_C_REMOVE,
530 	.flags = GENL_ADMIN_PERM,
531 	.policy = netlbl_mgmt_genl_policy,
532 	.doit = netlbl_mgmt_remove,
533 	.dumpit = NULL,
534 };
535 
536 static struct genl_ops netlbl_mgmt_genl_c_listall = {
537 	.cmd = NLBL_MGMT_C_LISTALL,
538 	.flags = 0,
539 	.policy = netlbl_mgmt_genl_policy,
540 	.doit = NULL,
541 	.dumpit = netlbl_mgmt_listall,
542 };
543 
544 static struct genl_ops netlbl_mgmt_genl_c_adddef = {
545 	.cmd = NLBL_MGMT_C_ADDDEF,
546 	.flags = GENL_ADMIN_PERM,
547 	.policy = netlbl_mgmt_genl_policy,
548 	.doit = netlbl_mgmt_adddef,
549 	.dumpit = NULL,
550 };
551 
552 static struct genl_ops netlbl_mgmt_genl_c_removedef = {
553 	.cmd = NLBL_MGMT_C_REMOVEDEF,
554 	.flags = GENL_ADMIN_PERM,
555 	.policy = netlbl_mgmt_genl_policy,
556 	.doit = netlbl_mgmt_removedef,
557 	.dumpit = NULL,
558 };
559 
560 static struct genl_ops netlbl_mgmt_genl_c_listdef = {
561 	.cmd = NLBL_MGMT_C_LISTDEF,
562 	.flags = 0,
563 	.policy = netlbl_mgmt_genl_policy,
564 	.doit = netlbl_mgmt_listdef,
565 	.dumpit = NULL,
566 };
567 
568 static struct genl_ops netlbl_mgmt_genl_c_protocols = {
569 	.cmd = NLBL_MGMT_C_PROTOCOLS,
570 	.flags = 0,
571 	.policy = netlbl_mgmt_genl_policy,
572 	.doit = NULL,
573 	.dumpit = netlbl_mgmt_protocols,
574 };
575 
576 static struct genl_ops netlbl_mgmt_genl_c_version = {
577 	.cmd = NLBL_MGMT_C_VERSION,
578 	.flags = 0,
579 	.policy = netlbl_mgmt_genl_policy,
580 	.doit = netlbl_mgmt_version,
581 	.dumpit = NULL,
582 };
583 
584 /*
585  * NetLabel Generic NETLINK Protocol Functions
586  */
587 
588 /**
589  * netlbl_mgmt_genl_init - Register the NetLabel management component
590  *
591  * Description:
592  * Register the NetLabel management component with the Generic NETLINK
593  * mechanism.  Returns zero on success, negative values on failure.
594  *
595  */
596 int netlbl_mgmt_genl_init(void)
597 {
598 	int ret_val;
599 
600 	ret_val = genl_register_family(&netlbl_mgmt_gnl_family);
601 	if (ret_val != 0)
602 		return ret_val;
603 
604 	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
605 				    &netlbl_mgmt_genl_c_add);
606 	if (ret_val != 0)
607 		return ret_val;
608 	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
609 				    &netlbl_mgmt_genl_c_remove);
610 	if (ret_val != 0)
611 		return ret_val;
612 	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
613 				    &netlbl_mgmt_genl_c_listall);
614 	if (ret_val != 0)
615 		return ret_val;
616 	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
617 				    &netlbl_mgmt_genl_c_adddef);
618 	if (ret_val != 0)
619 		return ret_val;
620 	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
621 				    &netlbl_mgmt_genl_c_removedef);
622 	if (ret_val != 0)
623 		return ret_val;
624 	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
625 				    &netlbl_mgmt_genl_c_listdef);
626 	if (ret_val != 0)
627 		return ret_val;
628 	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
629 				    &netlbl_mgmt_genl_c_protocols);
630 	if (ret_val != 0)
631 		return ret_val;
632 	ret_val = genl_register_ops(&netlbl_mgmt_gnl_family,
633 				    &netlbl_mgmt_genl_c_version);
634 	if (ret_val != 0)
635 		return ret_val;
636 
637 	return 0;
638 }
639