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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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