1 /*
2 * NetLabel Network Address Lists
3 *
4 * This file contains network address list functions used to manage ordered
5 * lists of network addresses for use by the NetLabel subsystem. The NetLabel
6 * system manages static and dynamic label mappings for network protocols such
7 * as CIPSO and RIPSO.
8 *
9 * Author: Paul Moore <paul@paul-moore.com>
10 *
11 */
12
13 /*
14 * (c) Copyright Hewlett-Packard Development Company, L.P., 2008
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or
19 * (at your option) any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
24 * the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program; if not, write to the Free Software
28 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 *
30 */
31
32 #include <linux/types.h>
33 #include <linux/rcupdate.h>
34 #include <linux/list.h>
35 #include <linux/spinlock.h>
36 #include <linux/in.h>
37 #include <linux/in6.h>
38 #include <linux/ip.h>
39 #include <linux/ipv6.h>
40 #include <net/ip.h>
41 #include <net/ipv6.h>
42 #include <linux/audit.h>
43
44 #include "netlabel_addrlist.h"
45
46 /*
47 * Address List Functions
48 */
49
50 /**
51 * netlbl_af4list_search - Search for a matching IPv4 address entry
52 * @addr: IPv4 address
53 * @head: the list head
54 *
55 * Description:
56 * Searches the IPv4 address list given by @head. If a matching address entry
57 * is found it is returned, otherwise NULL is returned. The caller is
58 * responsible for calling the rcu_read_[un]lock() functions.
59 *
60 */
netlbl_af4list_search(__be32 addr,struct list_head * head)61 struct netlbl_af4list *netlbl_af4list_search(__be32 addr,
62 struct list_head *head)
63 {
64 struct netlbl_af4list *iter;
65
66 list_for_each_entry_rcu(iter, head, list)
67 if (iter->valid && (addr & iter->mask) == iter->addr)
68 return iter;
69
70 return NULL;
71 }
72
73 /**
74 * netlbl_af4list_search_exact - Search for an exact IPv4 address entry
75 * @addr: IPv4 address
76 * @mask: IPv4 address mask
77 * @head: the list head
78 *
79 * Description:
80 * Searches the IPv4 address list given by @head. If an exact match if found
81 * it is returned, otherwise NULL is returned. The caller is responsible for
82 * calling the rcu_read_[un]lock() functions.
83 *
84 */
netlbl_af4list_search_exact(__be32 addr,__be32 mask,struct list_head * head)85 struct netlbl_af4list *netlbl_af4list_search_exact(__be32 addr,
86 __be32 mask,
87 struct list_head *head)
88 {
89 struct netlbl_af4list *iter;
90
91 list_for_each_entry_rcu(iter, head, list)
92 if (iter->valid && iter->addr == addr && iter->mask == mask)
93 return iter;
94
95 return NULL;
96 }
97
98
99 #if IS_ENABLED(CONFIG_IPV6)
100 /**
101 * netlbl_af6list_search - Search for a matching IPv6 address entry
102 * @addr: IPv6 address
103 * @head: the list head
104 *
105 * Description:
106 * Searches the IPv6 address list given by @head. If a matching address entry
107 * is found it is returned, otherwise NULL is returned. The caller is
108 * responsible for calling the rcu_read_[un]lock() functions.
109 *
110 */
netlbl_af6list_search(const struct in6_addr * addr,struct list_head * head)111 struct netlbl_af6list *netlbl_af6list_search(const struct in6_addr *addr,
112 struct list_head *head)
113 {
114 struct netlbl_af6list *iter;
115
116 list_for_each_entry_rcu(iter, head, list)
117 if (iter->valid &&
118 ipv6_masked_addr_cmp(&iter->addr, &iter->mask, addr) == 0)
119 return iter;
120
121 return NULL;
122 }
123
124 /**
125 * netlbl_af6list_search_exact - Search for an exact IPv6 address entry
126 * @addr: IPv6 address
127 * @mask: IPv6 address mask
128 * @head: the list head
129 *
130 * Description:
131 * Searches the IPv6 address list given by @head. If an exact match if found
132 * it is returned, otherwise NULL is returned. The caller is responsible for
133 * calling the rcu_read_[un]lock() functions.
134 *
135 */
netlbl_af6list_search_exact(const struct in6_addr * addr,const struct in6_addr * mask,struct list_head * head)136 struct netlbl_af6list *netlbl_af6list_search_exact(const struct in6_addr *addr,
137 const struct in6_addr *mask,
138 struct list_head *head)
139 {
140 struct netlbl_af6list *iter;
141
142 list_for_each_entry_rcu(iter, head, list)
143 if (iter->valid &&
144 ipv6_addr_equal(&iter->addr, addr) &&
145 ipv6_addr_equal(&iter->mask, mask))
146 return iter;
147
148 return NULL;
149 }
150 #endif /* IPv6 */
151
152 /**
153 * netlbl_af4list_add - Add a new IPv4 address entry to a list
154 * @entry: address entry
155 * @head: the list head
156 *
157 * Description:
158 * Add a new address entry to the list pointed to by @head. On success zero is
159 * returned, otherwise a negative value is returned. The caller is responsible
160 * for calling the necessary locking functions.
161 *
162 */
netlbl_af4list_add(struct netlbl_af4list * entry,struct list_head * head)163 int netlbl_af4list_add(struct netlbl_af4list *entry, struct list_head *head)
164 {
165 struct netlbl_af4list *iter;
166
167 iter = netlbl_af4list_search(entry->addr, head);
168 if (iter != NULL &&
169 iter->addr == entry->addr && iter->mask == entry->mask)
170 return -EEXIST;
171
172 /* in order to speed up address searches through the list (the common
173 * case) we need to keep the list in order based on the size of the
174 * address mask such that the entry with the widest mask (smallest
175 * numerical value) appears first in the list */
176 list_for_each_entry_rcu(iter, head, list)
177 if (iter->valid &&
178 ntohl(entry->mask) > ntohl(iter->mask)) {
179 __list_add_rcu(&entry->list,
180 iter->list.prev,
181 &iter->list);
182 return 0;
183 }
184 list_add_tail_rcu(&entry->list, head);
185 return 0;
186 }
187
188 #if IS_ENABLED(CONFIG_IPV6)
189 /**
190 * netlbl_af6list_add - Add a new IPv6 address entry to a list
191 * @entry: address entry
192 * @head: the list head
193 *
194 * Description:
195 * Add a new address entry to the list pointed to by @head. On success zero is
196 * returned, otherwise a negative value is returned. The caller is responsible
197 * for calling the necessary locking functions.
198 *
199 */
netlbl_af6list_add(struct netlbl_af6list * entry,struct list_head * head)200 int netlbl_af6list_add(struct netlbl_af6list *entry, struct list_head *head)
201 {
202 struct netlbl_af6list *iter;
203
204 iter = netlbl_af6list_search(&entry->addr, head);
205 if (iter != NULL &&
206 ipv6_addr_equal(&iter->addr, &entry->addr) &&
207 ipv6_addr_equal(&iter->mask, &entry->mask))
208 return -EEXIST;
209
210 /* in order to speed up address searches through the list (the common
211 * case) we need to keep the list in order based on the size of the
212 * address mask such that the entry with the widest mask (smallest
213 * numerical value) appears first in the list */
214 list_for_each_entry_rcu(iter, head, list)
215 if (iter->valid &&
216 ipv6_addr_cmp(&entry->mask, &iter->mask) > 0) {
217 __list_add_rcu(&entry->list,
218 iter->list.prev,
219 &iter->list);
220 return 0;
221 }
222 list_add_tail_rcu(&entry->list, head);
223 return 0;
224 }
225 #endif /* IPv6 */
226
227 /**
228 * netlbl_af4list_remove_entry - Remove an IPv4 address entry
229 * @entry: address entry
230 *
231 * Description:
232 * Remove the specified IP address entry. The caller is responsible for
233 * calling the necessary locking functions.
234 *
235 */
netlbl_af4list_remove_entry(struct netlbl_af4list * entry)236 void netlbl_af4list_remove_entry(struct netlbl_af4list *entry)
237 {
238 entry->valid = 0;
239 list_del_rcu(&entry->list);
240 }
241
242 /**
243 * netlbl_af4list_remove - Remove an IPv4 address entry
244 * @addr: IP address
245 * @mask: IP address mask
246 * @head: the list head
247 *
248 * Description:
249 * Remove an IP address entry from the list pointed to by @head. Returns the
250 * entry on success, NULL on failure. The caller is responsible for calling
251 * the necessary locking functions.
252 *
253 */
netlbl_af4list_remove(__be32 addr,__be32 mask,struct list_head * head)254 struct netlbl_af4list *netlbl_af4list_remove(__be32 addr, __be32 mask,
255 struct list_head *head)
256 {
257 struct netlbl_af4list *entry;
258
259 entry = netlbl_af4list_search_exact(addr, mask, head);
260 if (entry == NULL)
261 return NULL;
262 netlbl_af4list_remove_entry(entry);
263 return entry;
264 }
265
266 #if IS_ENABLED(CONFIG_IPV6)
267 /**
268 * netlbl_af6list_remove_entry - Remove an IPv6 address entry
269 * @entry: address entry
270 *
271 * Description:
272 * Remove the specified IP address entry. The caller is responsible for
273 * calling the necessary locking functions.
274 *
275 */
netlbl_af6list_remove_entry(struct netlbl_af6list * entry)276 void netlbl_af6list_remove_entry(struct netlbl_af6list *entry)
277 {
278 entry->valid = 0;
279 list_del_rcu(&entry->list);
280 }
281
282 /**
283 * netlbl_af6list_remove - Remove an IPv6 address entry
284 * @addr: IP address
285 * @mask: IP address mask
286 * @head: the list head
287 *
288 * Description:
289 * Remove an IP address entry from the list pointed to by @head. Returns the
290 * entry on success, NULL on failure. The caller is responsible for calling
291 * the necessary locking functions.
292 *
293 */
netlbl_af6list_remove(const struct in6_addr * addr,const struct in6_addr * mask,struct list_head * head)294 struct netlbl_af6list *netlbl_af6list_remove(const struct in6_addr *addr,
295 const struct in6_addr *mask,
296 struct list_head *head)
297 {
298 struct netlbl_af6list *entry;
299
300 entry = netlbl_af6list_search_exact(addr, mask, head);
301 if (entry == NULL)
302 return NULL;
303 netlbl_af6list_remove_entry(entry);
304 return entry;
305 }
306 #endif /* IPv6 */
307
308 /*
309 * Audit Helper Functions
310 */
311
312 #ifdef CONFIG_AUDIT
313 /**
314 * netlbl_af4list_audit_addr - Audit an IPv4 address
315 * @audit_buf: audit buffer
316 * @src: true if source address, false if destination
317 * @dev: network interface
318 * @addr: IP address
319 * @mask: IP address mask
320 *
321 * Description:
322 * Write the IPv4 address and address mask, if necessary, to @audit_buf.
323 *
324 */
netlbl_af4list_audit_addr(struct audit_buffer * audit_buf,int src,const char * dev,__be32 addr,__be32 mask)325 void netlbl_af4list_audit_addr(struct audit_buffer *audit_buf,
326 int src, const char *dev,
327 __be32 addr, __be32 mask)
328 {
329 u32 mask_val = ntohl(mask);
330 char *dir = (src ? "src" : "dst");
331
332 if (dev != NULL)
333 audit_log_format(audit_buf, " netif=%s", dev);
334 audit_log_format(audit_buf, " %s=%pI4", dir, &addr);
335 if (mask_val != 0xffffffff) {
336 u32 mask_len = 0;
337 while (mask_val > 0) {
338 mask_val <<= 1;
339 mask_len++;
340 }
341 audit_log_format(audit_buf, " %s_prefixlen=%d", dir, mask_len);
342 }
343 }
344
345 #if IS_ENABLED(CONFIG_IPV6)
346 /**
347 * netlbl_af6list_audit_addr - Audit an IPv6 address
348 * @audit_buf: audit buffer
349 * @src: true if source address, false if destination
350 * @dev: network interface
351 * @addr: IP address
352 * @mask: IP address mask
353 *
354 * Description:
355 * Write the IPv6 address and address mask, if necessary, to @audit_buf.
356 *
357 */
netlbl_af6list_audit_addr(struct audit_buffer * audit_buf,int src,const char * dev,const struct in6_addr * addr,const struct in6_addr * mask)358 void netlbl_af6list_audit_addr(struct audit_buffer *audit_buf,
359 int src,
360 const char *dev,
361 const struct in6_addr *addr,
362 const struct in6_addr *mask)
363 {
364 char *dir = (src ? "src" : "dst");
365
366 if (dev != NULL)
367 audit_log_format(audit_buf, " netif=%s", dev);
368 audit_log_format(audit_buf, " %s=%pI6", dir, addr);
369 if (ntohl(mask->s6_addr32[3]) != 0xffffffff) {
370 u32 mask_len = 0;
371 u32 mask_val;
372 int iter = -1;
373 while (ntohl(mask->s6_addr32[++iter]) == 0xffffffff)
374 mask_len += 32;
375 mask_val = ntohl(mask->s6_addr32[iter]);
376 while (mask_val > 0) {
377 mask_val <<= 1;
378 mask_len++;
379 }
380 audit_log_format(audit_buf, " %s_prefixlen=%d", dir, mask_len);
381 }
382 }
383 #endif /* IPv6 */
384 #endif /* CONFIG_AUDIT */
385