David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 1 | /* auditfilter.c -- filtering of audit events |
| 2 | * |
| 3 | * Copyright 2003-2004 Red Hat, Inc. |
| 4 | * Copyright 2005 Hewlett-Packard Development Company, L.P. |
| 5 | * Copyright 2005 IBM Corporation |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 20 | */ |
| 21 | |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/audit.h> |
| 24 | #include <linux/kthread.h> |
| 25 | #include <linux/netlink.h> |
| 26 | #include "audit.h" |
| 27 | |
| 28 | /* There are three lists of rules -- one to search at task creation |
| 29 | * time, one to search at syscall entry time, and another to search at |
| 30 | * syscall exit time. */ |
| 31 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
| 32 | LIST_HEAD_INIT(audit_filter_list[0]), |
| 33 | LIST_HEAD_INIT(audit_filter_list[1]), |
| 34 | LIST_HEAD_INIT(audit_filter_list[2]), |
| 35 | LIST_HEAD_INIT(audit_filter_list[3]), |
| 36 | LIST_HEAD_INIT(audit_filter_list[4]), |
| 37 | LIST_HEAD_INIT(audit_filter_list[5]), |
| 38 | #if AUDIT_NR_FILTERS != 6 |
| 39 | #error Fix audit_filter_list initialiser |
| 40 | #endif |
| 41 | }; |
| 42 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 43 | static inline void audit_free_rule(struct audit_entry *e) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 44 | { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 45 | kfree(e->rule.fields); |
| 46 | kfree(e); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 47 | } |
| 48 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 49 | static inline void audit_free_rule_rcu(struct rcu_head *head) |
| 50 | { |
| 51 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); |
| 52 | audit_free_rule(e); |
| 53 | } |
| 54 | |
| 55 | /* Unpack a filter field's string representation from user-space |
| 56 | * buffer. */ |
| 57 | static __attribute__((unused)) char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
| 58 | { |
| 59 | char *str; |
| 60 | |
| 61 | if (!*bufp || (len == 0) || (len > *remain)) |
| 62 | return ERR_PTR(-EINVAL); |
| 63 | |
| 64 | /* Of the currently implemented string fields, PATH_MAX |
| 65 | * defines the longest valid length. |
| 66 | */ |
| 67 | if (len > PATH_MAX) |
| 68 | return ERR_PTR(-ENAMETOOLONG); |
| 69 | |
| 70 | str = kmalloc(len + 1, GFP_KERNEL); |
| 71 | if (unlikely(!str)) |
| 72 | return ERR_PTR(-ENOMEM); |
| 73 | |
| 74 | memcpy(str, *bufp, len); |
| 75 | str[len] = 0; |
| 76 | *bufp += len; |
| 77 | *remain -= len; |
| 78 | |
| 79 | return str; |
| 80 | } |
| 81 | |
| 82 | /* Common user-space to kernel rule translation. */ |
| 83 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) |
| 84 | { |
| 85 | unsigned listnr; |
| 86 | struct audit_entry *entry; |
| 87 | struct audit_field *fields; |
| 88 | int i, err; |
| 89 | |
| 90 | err = -EINVAL; |
| 91 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; |
| 92 | switch(listnr) { |
| 93 | default: |
| 94 | goto exit_err; |
| 95 | case AUDIT_FILTER_USER: |
| 96 | case AUDIT_FILTER_TYPE: |
| 97 | #ifdef CONFIG_AUDITSYSCALL |
| 98 | case AUDIT_FILTER_ENTRY: |
| 99 | case AUDIT_FILTER_EXIT: |
| 100 | case AUDIT_FILTER_TASK: |
| 101 | #endif |
| 102 | ; |
| 103 | } |
| 104 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_POSSIBLE && |
| 105 | rule->action != AUDIT_ALWAYS) |
| 106 | goto exit_err; |
| 107 | if (rule->field_count > AUDIT_MAX_FIELDS) |
| 108 | goto exit_err; |
| 109 | |
| 110 | err = -ENOMEM; |
| 111 | entry = kmalloc(sizeof(*entry), GFP_KERNEL); |
| 112 | if (unlikely(!entry)) |
| 113 | goto exit_err; |
| 114 | fields = kmalloc(sizeof(*fields) * rule->field_count, GFP_KERNEL); |
| 115 | if (unlikely(!fields)) { |
| 116 | kfree(entry); |
| 117 | goto exit_err; |
| 118 | } |
| 119 | |
| 120 | memset(&entry->rule, 0, sizeof(struct audit_krule)); |
| 121 | memset(fields, 0, sizeof(struct audit_field)); |
| 122 | |
| 123 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; |
| 124 | entry->rule.listnr = listnr; |
| 125 | entry->rule.action = rule->action; |
| 126 | entry->rule.field_count = rule->field_count; |
| 127 | entry->rule.fields = fields; |
| 128 | |
| 129 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
| 130 | entry->rule.mask[i] = rule->mask[i]; |
| 131 | |
| 132 | return entry; |
| 133 | |
| 134 | exit_err: |
| 135 | return ERR_PTR(err); |
| 136 | } |
| 137 | |
| 138 | /* Translate struct audit_rule to kernel's rule respresentation. |
| 139 | * Exists for backward compatibility with userspace. */ |
| 140 | static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) |
| 141 | { |
| 142 | struct audit_entry *entry; |
| 143 | int err = 0; |
| 144 | int i; |
| 145 | |
| 146 | entry = audit_to_entry_common(rule); |
| 147 | if (IS_ERR(entry)) |
| 148 | goto exit_nofree; |
| 149 | |
| 150 | for (i = 0; i < rule->field_count; i++) { |
| 151 | struct audit_field *f = &entry->rule.fields[i]; |
| 152 | |
| 153 | if (rule->fields[i] & AUDIT_UNUSED_BITS) { |
| 154 | err = -EINVAL; |
| 155 | goto exit_free; |
| 156 | } |
| 157 | |
| 158 | f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); |
| 159 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); |
| 160 | f->val = rule->values[i]; |
| 161 | |
| 162 | entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; |
Dustin Kirkland | d9d9ec6 | 2006-02-16 13:40:01 -0600 | [diff] [blame] | 163 | |
| 164 | /* Support for legacy operators where |
| 165 | * AUDIT_NEGATE bit signifies != and otherwise assumes == */ |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 166 | if (f->op & AUDIT_NEGATE) |
Dustin Kirkland | d9d9ec6 | 2006-02-16 13:40:01 -0600 | [diff] [blame] | 167 | f->op = AUDIT_NOT_EQUAL; |
| 168 | else if (!f->op) |
| 169 | f->op = AUDIT_EQUAL; |
| 170 | else if (f->op == AUDIT_OPERATORS) { |
| 171 | err = -EINVAL; |
| 172 | goto exit_free; |
| 173 | } |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 174 | } |
| 175 | |
| 176 | exit_nofree: |
| 177 | return entry; |
| 178 | |
| 179 | exit_free: |
| 180 | audit_free_rule(entry); |
| 181 | return ERR_PTR(err); |
| 182 | } |
| 183 | |
| 184 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
| 185 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, |
| 186 | size_t datasz) |
| 187 | { |
| 188 | int err = 0; |
| 189 | struct audit_entry *entry; |
| 190 | void *bufp; |
| 191 | /* size_t remain = datasz - sizeof(struct audit_rule_data); */ |
| 192 | int i; |
| 193 | |
| 194 | entry = audit_to_entry_common((struct audit_rule *)data); |
| 195 | if (IS_ERR(entry)) |
| 196 | goto exit_nofree; |
| 197 | |
| 198 | bufp = data->buf; |
| 199 | entry->rule.vers_ops = 2; |
| 200 | for (i = 0; i < data->field_count; i++) { |
| 201 | struct audit_field *f = &entry->rule.fields[i]; |
| 202 | |
| 203 | err = -EINVAL; |
| 204 | if (!(data->fieldflags[i] & AUDIT_OPERATORS) || |
| 205 | data->fieldflags[i] & ~AUDIT_OPERATORS) |
| 206 | goto exit_free; |
| 207 | |
| 208 | f->op = data->fieldflags[i] & AUDIT_OPERATORS; |
| 209 | f->type = data->fields[i]; |
| 210 | switch(f->type) { |
| 211 | /* call type-specific conversion routines here */ |
| 212 | default: |
| 213 | f->val = data->values[i]; |
| 214 | } |
| 215 | } |
| 216 | |
| 217 | exit_nofree: |
| 218 | return entry; |
| 219 | |
| 220 | exit_free: |
| 221 | audit_free_rule(entry); |
| 222 | return ERR_PTR(err); |
| 223 | } |
| 224 | |
| 225 | /* Pack a filter field's string representation into data block. */ |
| 226 | static inline size_t audit_pack_string(void **bufp, char *str) |
| 227 | { |
| 228 | size_t len = strlen(str); |
| 229 | |
| 230 | memcpy(*bufp, str, len); |
| 231 | *bufp += len; |
| 232 | |
| 233 | return len; |
| 234 | } |
| 235 | |
| 236 | /* Translate kernel rule respresentation to struct audit_rule. |
| 237 | * Exists for backward compatibility with userspace. */ |
| 238 | static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) |
| 239 | { |
| 240 | struct audit_rule *rule; |
| 241 | int i; |
| 242 | |
| 243 | rule = kmalloc(sizeof(*rule), GFP_KERNEL); |
| 244 | if (unlikely(!rule)) |
| 245 | return ERR_PTR(-ENOMEM); |
| 246 | memset(rule, 0, sizeof(*rule)); |
| 247 | |
| 248 | rule->flags = krule->flags | krule->listnr; |
| 249 | rule->action = krule->action; |
| 250 | rule->field_count = krule->field_count; |
| 251 | for (i = 0; i < rule->field_count; i++) { |
| 252 | rule->values[i] = krule->fields[i].val; |
| 253 | rule->fields[i] = krule->fields[i].type; |
| 254 | |
| 255 | if (krule->vers_ops == 1) { |
| 256 | if (krule->fields[i].op & AUDIT_NOT_EQUAL) |
| 257 | rule->fields[i] |= AUDIT_NEGATE; |
| 258 | } else { |
| 259 | rule->fields[i] |= krule->fields[i].op; |
| 260 | } |
| 261 | } |
| 262 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; |
| 263 | |
| 264 | return rule; |
| 265 | } |
| 266 | |
| 267 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
| 268 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) |
| 269 | { |
| 270 | struct audit_rule_data *data; |
| 271 | void *bufp; |
| 272 | int i; |
| 273 | |
| 274 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); |
| 275 | if (unlikely(!data)) |
| 276 | return ERR_PTR(-ENOMEM); |
| 277 | memset(data, 0, sizeof(*data)); |
| 278 | |
| 279 | data->flags = krule->flags | krule->listnr; |
| 280 | data->action = krule->action; |
| 281 | data->field_count = krule->field_count; |
| 282 | bufp = data->buf; |
| 283 | for (i = 0; i < data->field_count; i++) { |
| 284 | struct audit_field *f = &krule->fields[i]; |
| 285 | |
| 286 | data->fields[i] = f->type; |
| 287 | data->fieldflags[i] = f->op; |
| 288 | switch(f->type) { |
| 289 | /* call type-specific conversion routines here */ |
| 290 | default: |
| 291 | data->values[i] = f->val; |
| 292 | } |
| 293 | } |
| 294 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; |
| 295 | |
| 296 | return data; |
| 297 | } |
| 298 | |
| 299 | /* Compare two rules in kernel format. Considered success if rules |
| 300 | * don't match. */ |
| 301 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 302 | { |
| 303 | int i; |
| 304 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 305 | if (a->flags != b->flags || |
| 306 | a->listnr != b->listnr || |
| 307 | a->action != b->action || |
| 308 | a->field_count != b->field_count) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 309 | return 1; |
| 310 | |
| 311 | for (i = 0; i < a->field_count; i++) { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 312 | if (a->fields[i].type != b->fields[i].type || |
| 313 | a->fields[i].op != b->fields[i].op) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 314 | return 1; |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 315 | |
| 316 | switch(a->fields[i].type) { |
| 317 | /* call type-specific comparison routines here */ |
| 318 | default: |
| 319 | if (a->fields[i].val != b->fields[i].val) |
| 320 | return 1; |
| 321 | } |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 322 | } |
| 323 | |
| 324 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
| 325 | if (a->mask[i] != b->mask[i]) |
| 326 | return 1; |
| 327 | |
| 328 | return 0; |
| 329 | } |
| 330 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 331 | /* Add rule to given filterlist if not a duplicate. Protected by |
Ingo Molnar | 5a0bbce | 2006-03-07 23:51:38 -0800 | [diff] [blame] | 332 | * audit_netlink_mutex. */ |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 333 | static inline int audit_add_rule(struct audit_entry *entry, |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 334 | struct list_head *list) |
| 335 | { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 336 | struct audit_entry *e; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 337 | |
| 338 | /* Do not use the _rcu iterator here, since this is the only |
| 339 | * addition routine. */ |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 340 | list_for_each_entry(e, list, list) { |
| 341 | if (!audit_compare_rule(&entry->rule, &e->rule)) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 342 | return -EEXIST; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 343 | } |
| 344 | |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 345 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 346 | list_add_rcu(&entry->list, list); |
| 347 | } else { |
| 348 | list_add_tail_rcu(&entry->list, list); |
| 349 | } |
| 350 | |
| 351 | return 0; |
| 352 | } |
| 353 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 354 | /* Remove an existing rule from filterlist. Protected by |
Ingo Molnar | 5a0bbce | 2006-03-07 23:51:38 -0800 | [diff] [blame] | 355 | * audit_netlink_mutex. */ |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 356 | static inline int audit_del_rule(struct audit_entry *entry, |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 357 | struct list_head *list) |
| 358 | { |
| 359 | struct audit_entry *e; |
| 360 | |
| 361 | /* Do not use the _rcu iterator here, since this is the only |
| 362 | * deletion routine. */ |
| 363 | list_for_each_entry(e, list, list) { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 364 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 365 | list_del_rcu(&e->list); |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 366 | call_rcu(&e->rcu, audit_free_rule_rcu); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 367 | return 0; |
| 368 | } |
| 369 | } |
| 370 | return -ENOENT; /* No matching rule */ |
| 371 | } |
| 372 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 373 | /* List rules using struct audit_rule. Exists for backward |
| 374 | * compatibility with userspace. */ |
| 375 | static int audit_list(void *_dest) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 376 | { |
| 377 | int pid, seq; |
| 378 | int *dest = _dest; |
| 379 | struct audit_entry *entry; |
| 380 | int i; |
| 381 | |
| 382 | pid = dest[0]; |
| 383 | seq = dest[1]; |
| 384 | kfree(dest); |
| 385 | |
Ingo Molnar | 5a0bbce | 2006-03-07 23:51:38 -0800 | [diff] [blame] | 386 | mutex_lock(&audit_netlink_mutex); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 387 | |
| 388 | /* The *_rcu iterators not needed here because we are |
Ingo Molnar | 5a0bbce | 2006-03-07 23:51:38 -0800 | [diff] [blame] | 389 | always called with audit_netlink_mutex held. */ |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 390 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 391 | list_for_each_entry(entry, &audit_filter_list[i], list) { |
| 392 | struct audit_rule *rule; |
| 393 | |
| 394 | rule = audit_krule_to_rule(&entry->rule); |
| 395 | if (unlikely(!rule)) |
| 396 | break; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 397 | audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 398 | rule, sizeof(*rule)); |
| 399 | kfree(rule); |
| 400 | } |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 401 | } |
| 402 | audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
| 403 | |
Ingo Molnar | 5a0bbce | 2006-03-07 23:51:38 -0800 | [diff] [blame] | 404 | mutex_unlock(&audit_netlink_mutex); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 405 | return 0; |
| 406 | } |
| 407 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 408 | /* List rules using struct audit_rule_data. */ |
| 409 | static int audit_list_rules(void *_dest) |
| 410 | { |
| 411 | int pid, seq; |
| 412 | int *dest = _dest; |
| 413 | struct audit_entry *e; |
| 414 | int i; |
| 415 | |
| 416 | pid = dest[0]; |
| 417 | seq = dest[1]; |
| 418 | kfree(dest); |
| 419 | |
Ingo Molnar | 5a0bbce | 2006-03-07 23:51:38 -0800 | [diff] [blame] | 420 | mutex_lock(&audit_netlink_mutex); |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 421 | |
| 422 | /* The *_rcu iterators not needed here because we are |
Ingo Molnar | 5a0bbce | 2006-03-07 23:51:38 -0800 | [diff] [blame] | 423 | always called with audit_netlink_mutex held. */ |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 424 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
| 425 | list_for_each_entry(e, &audit_filter_list[i], list) { |
| 426 | struct audit_rule_data *data; |
| 427 | |
| 428 | data = audit_krule_to_data(&e->rule); |
| 429 | if (unlikely(!data)) |
| 430 | break; |
| 431 | audit_send_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
| 432 | data, sizeof(*data)); |
| 433 | kfree(data); |
| 434 | } |
| 435 | } |
| 436 | audit_send_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
| 437 | |
Ingo Molnar | 5a0bbce | 2006-03-07 23:51:38 -0800 | [diff] [blame] | 438 | mutex_unlock(&audit_netlink_mutex); |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 439 | return 0; |
| 440 | } |
| 441 | |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 442 | /** |
| 443 | * audit_receive_filter - apply all rules to the specified message type |
| 444 | * @type: audit message type |
| 445 | * @pid: target pid for netlink audit messages |
| 446 | * @uid: target uid for netlink audit messages |
| 447 | * @seq: netlink audit message sequence (serial) number |
| 448 | * @data: payload data |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 449 | * @datasz: size of payload data |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 450 | * @loginuid: loginuid of sender |
| 451 | */ |
| 452 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 453 | size_t datasz, uid_t loginuid) |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 454 | { |
| 455 | struct task_struct *tsk; |
| 456 | int *dest; |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 457 | int err = 0; |
| 458 | struct audit_entry *entry; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 459 | |
| 460 | switch (type) { |
| 461 | case AUDIT_LIST: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 462 | case AUDIT_LIST_RULES: |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 463 | /* We can't just spew out the rules here because we might fill |
| 464 | * the available socket buffer space and deadlock waiting for |
| 465 | * auditctl to read from it... which isn't ever going to |
| 466 | * happen if we're actually running in the context of auditctl |
| 467 | * trying to _send_ the stuff */ |
| 468 | |
| 469 | dest = kmalloc(2 * sizeof(int), GFP_KERNEL); |
| 470 | if (!dest) |
| 471 | return -ENOMEM; |
| 472 | dest[0] = pid; |
| 473 | dest[1] = seq; |
| 474 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 475 | if (type == AUDIT_LIST) |
| 476 | tsk = kthread_run(audit_list, dest, "audit_list"); |
| 477 | else |
| 478 | tsk = kthread_run(audit_list_rules, dest, |
| 479 | "audit_list_rules"); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 480 | if (IS_ERR(tsk)) { |
| 481 | kfree(dest); |
| 482 | err = PTR_ERR(tsk); |
| 483 | } |
| 484 | break; |
| 485 | case AUDIT_ADD: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 486 | case AUDIT_ADD_RULE: |
| 487 | if (type == AUDIT_ADD) |
| 488 | entry = audit_rule_to_entry(data); |
| 489 | else |
| 490 | entry = audit_data_to_entry(data, datasz); |
| 491 | if (IS_ERR(entry)) |
| 492 | return PTR_ERR(entry); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 493 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 494 | err = audit_add_rule(entry, |
| 495 | &audit_filter_list[entry->rule.listnr]); |
Steve Grubb | 5d33010 | 2006-01-09 09:48:17 -0500 | [diff] [blame] | 496 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, |
| 497 | "auid=%u add rule to list=%d res=%d\n", |
| 498 | loginuid, entry->rule.listnr, !err); |
| 499 | |
| 500 | if (err) |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 501 | audit_free_rule(entry); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 502 | break; |
| 503 | case AUDIT_DEL: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 504 | case AUDIT_DEL_RULE: |
| 505 | if (type == AUDIT_DEL) |
| 506 | entry = audit_rule_to_entry(data); |
| 507 | else |
| 508 | entry = audit_data_to_entry(data, datasz); |
| 509 | if (IS_ERR(entry)) |
| 510 | return PTR_ERR(entry); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 511 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 512 | err = audit_del_rule(entry, |
| 513 | &audit_filter_list[entry->rule.listnr]); |
Steve Grubb | 5d33010 | 2006-01-09 09:48:17 -0500 | [diff] [blame] | 514 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, |
| 515 | "auid=%u remove rule from list=%d res=%d\n", |
| 516 | loginuid, entry->rule.listnr, !err); |
| 517 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 518 | audit_free_rule(entry); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 519 | break; |
| 520 | default: |
| 521 | return -EINVAL; |
| 522 | } |
| 523 | |
| 524 | return err; |
| 525 | } |
| 526 | |
| 527 | int audit_comparator(const u32 left, const u32 op, const u32 right) |
| 528 | { |
| 529 | switch (op) { |
| 530 | case AUDIT_EQUAL: |
| 531 | return (left == right); |
| 532 | case AUDIT_NOT_EQUAL: |
| 533 | return (left != right); |
| 534 | case AUDIT_LESS_THAN: |
| 535 | return (left < right); |
| 536 | case AUDIT_LESS_THAN_OR_EQUAL: |
| 537 | return (left <= right); |
| 538 | case AUDIT_GREATER_THAN: |
| 539 | return (left > right); |
| 540 | case AUDIT_GREATER_THAN_OR_EQUAL: |
| 541 | return (left >= right); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 542 | } |
Dustin Kirkland | d9d9ec6 | 2006-02-16 13:40:01 -0600 | [diff] [blame] | 543 | BUG(); |
| 544 | return 0; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 545 | } |
| 546 | |
| 547 | |
| 548 | |
| 549 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 550 | struct audit_krule *rule, |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 551 | enum audit_state *state) |
| 552 | { |
| 553 | int i; |
| 554 | |
| 555 | for (i = 0; i < rule->field_count; i++) { |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 556 | struct audit_field *f = &rule->fields[i]; |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 557 | int result = 0; |
| 558 | |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 559 | switch (f->type) { |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 560 | case AUDIT_PID: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 561 | result = audit_comparator(cb->creds.pid, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 562 | break; |
| 563 | case AUDIT_UID: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 564 | result = audit_comparator(cb->creds.uid, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 565 | break; |
| 566 | case AUDIT_GID: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 567 | result = audit_comparator(cb->creds.gid, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 568 | break; |
| 569 | case AUDIT_LOGINUID: |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 570 | result = audit_comparator(cb->loginuid, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 571 | break; |
| 572 | } |
| 573 | |
| 574 | if (!result) |
| 575 | return 0; |
| 576 | } |
| 577 | switch (rule->action) { |
| 578 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; |
| 579 | case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break; |
| 580 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
| 581 | } |
| 582 | return 1; |
| 583 | } |
| 584 | |
| 585 | int audit_filter_user(struct netlink_skb_parms *cb, int type) |
| 586 | { |
| 587 | struct audit_entry *e; |
| 588 | enum audit_state state; |
| 589 | int ret = 1; |
| 590 | |
| 591 | rcu_read_lock(); |
| 592 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { |
| 593 | if (audit_filter_user_rules(cb, &e->rule, &state)) { |
| 594 | if (state == AUDIT_DISABLED) |
| 595 | ret = 0; |
| 596 | break; |
| 597 | } |
| 598 | } |
| 599 | rcu_read_unlock(); |
| 600 | |
| 601 | return ret; /* Audit by default */ |
| 602 | } |
| 603 | |
| 604 | int audit_filter_type(int type) |
| 605 | { |
| 606 | struct audit_entry *e; |
| 607 | int result = 0; |
| 608 | |
| 609 | rcu_read_lock(); |
| 610 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) |
| 611 | goto unlock_and_return; |
| 612 | |
| 613 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], |
| 614 | list) { |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 615 | int i; |
Amy Griffis | 93315ed | 2006-02-07 12:05:27 -0500 | [diff] [blame] | 616 | for (i = 0; i < e->rule.field_count; i++) { |
| 617 | struct audit_field *f = &e->rule.fields[i]; |
| 618 | if (f->type == AUDIT_MSGTYPE) { |
| 619 | result = audit_comparator(type, f->op, f->val); |
David Woodhouse | fe7752b | 2005-12-15 18:33:52 +0000 | [diff] [blame] | 620 | if (!result) |
| 621 | break; |
| 622 | } |
| 623 | } |
| 624 | if (result) |
| 625 | goto unlock_and_return; |
| 626 | } |
| 627 | unlock_and_return: |
| 628 | rcu_read_unlock(); |
| 629 | return result; |
| 630 | } |