| 85c8721 | 2005-04-29 16:23:29 +0100 | [diff] [blame] | 1 | /* audit.c -- Auditing support |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Gateway between the kernel (e.g., selinux) and the user-space audit daemon. |
| 3 | * System-call specific features have moved to auditsc.c |
| 4 | * |
| 5 | * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. |
| 6 | * All Rights Reserved. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License as published by |
| 10 | * the Free Software Foundation; either version 2 of the License, or |
| 11 | * (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | * |
| 22 | * Written by Rickard E. (Rik) Faith <faith@redhat.com> |
| 23 | * |
| 24 | * Goals: 1) Integrate fully with SELinux. |
| 25 | * 2) Minimal run-time overhead: |
| 26 | * a) Minimal when syscall auditing is disabled (audit_enable=0). |
| 27 | * b) Small when syscall auditing is enabled and no audit record |
| 28 | * is generated (defer as much work as possible to record |
| 29 | * generation time): |
| 30 | * i) context is allocated, |
| 31 | * ii) names from getname are stored without a copy, and |
| 32 | * iii) inode information stored from path_lookup. |
| 33 | * 3) Ability to disable syscall auditing at boot time (audit=0). |
| 34 | * 4) Usable by other parts of the kernel (if audit_log* is called, |
| 35 | * then a syscall record will be generated automatically for the |
| 36 | * current syscall). |
| 37 | * 5) Netlink interface to user-space. |
| 38 | * 6) Support low-overhead kernel-based filtering to minimize the |
| 39 | * information that must be passed to user-space. |
| 40 | * |
| 85c8721 | 2005-04-29 16:23:29 +0100 | [diff] [blame] | 41 | * Example user-space utilities: http://people.redhat.com/sgrubb/audit/ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | */ |
| 43 | |
| 44 | #include <linux/init.h> |
| 45 | #include <asm/atomic.h> |
| 46 | #include <asm/types.h> |
| 47 | #include <linux/mm.h> |
| 48 | #include <linux/module.h> |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 49 | #include <linux/err.h> |
| 50 | #include <linux/kthread.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
| 52 | #include <linux/audit.h> |
| 53 | |
| 54 | #include <net/sock.h> |
| 55 | #include <linux/skbuff.h> |
| 56 | #include <linux/netlink.h> |
| 57 | |
| 58 | /* No auditing will take place until audit_initialized != 0. |
| 59 | * (Initialization happens after skb_init is called.) */ |
| 60 | static int audit_initialized; |
| 61 | |
| 62 | /* No syscall auditing will take place unless audit_enabled != 0. */ |
| 63 | int audit_enabled; |
| 64 | |
| 65 | /* Default state when kernel boots without any parameters. */ |
| 66 | static int audit_default; |
| 67 | |
| 68 | /* If auditing cannot proceed, audit_failure selects what happens. */ |
| 69 | static int audit_failure = AUDIT_FAIL_PRINTK; |
| 70 | |
| 71 | /* If audit records are to be written to the netlink socket, audit_pid |
| 72 | * contains the (non-zero) pid. */ |
Steve Grubb | c2f0c7c | 2005-05-06 12:38:39 +0100 | [diff] [blame] | 73 | int audit_pid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 74 | |
| 75 | /* If audit_limit is non-zero, limit the rate of sending audit records |
| 76 | * to that number per second. This prevents DoS attacks, but results in |
| 77 | * audit records being dropped. */ |
| 78 | static int audit_rate_limit; |
| 79 | |
| 80 | /* Number of outstanding audit_buffers allowed. */ |
| 81 | static int audit_backlog_limit = 64; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | |
Steve Grubb | c2f0c7c | 2005-05-06 12:38:39 +0100 | [diff] [blame] | 83 | /* The identity of the user shutting down the audit system. */ |
| 84 | uid_t audit_sig_uid = -1; |
| 85 | pid_t audit_sig_pid = -1; |
| 86 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | /* Records can be lost in several ways: |
| 88 | 0) [suppressed in audit_alloc] |
| 89 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] |
| 90 | 2) out of memory in audit_log_move [alloc_skb] |
| 91 | 3) suppressed due to audit_rate_limit |
| 92 | 4) suppressed due to audit_backlog_limit |
| 93 | */ |
| 94 | static atomic_t audit_lost = ATOMIC_INIT(0); |
| 95 | |
| 96 | /* The netlink socket. */ |
| 97 | static struct sock *audit_sock; |
| 98 | |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 99 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
| 101 | * being placed on the freelist). */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | static DEFINE_SPINLOCK(audit_freelist_lock); |
| 103 | static int audit_freelist_count = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | static LIST_HEAD(audit_freelist); |
| 105 | |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 106 | static struct sk_buff_head audit_skb_queue; |
| 107 | static struct task_struct *kauditd_task; |
| 108 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); |
| 109 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | /* The netlink socket is only to be read by 1 CPU, which lets us assume |
Steve Grubb | 23f32d1 | 2005-05-13 18:35:15 +0100 | [diff] [blame] | 111 | * that list additions and deletions never happen simultaneously in |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | * auditsc.c */ |
| 113 | static DECLARE_MUTEX(audit_netlink_sem); |
| 114 | |
| 115 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting |
| 116 | * audit records. Since printk uses a 1024 byte buffer, this buffer |
| 117 | * should be at least that large. */ |
| 118 | #define AUDIT_BUFSIZ 1024 |
| 119 | |
| 120 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the |
| 121 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ |
| 122 | #define AUDIT_MAXFREE (2*NR_CPUS) |
| 123 | |
| 124 | /* The audit_buffer is used when formatting an audit record. The caller |
| 125 | * locks briefly to get the record off the freelist or to allocate the |
| 126 | * buffer, and locks briefly to send the buffer to the netlink layer or |
| 127 | * to place it on a transmit queue. Multiple audit_buffers can be in |
| 128 | * use simultaneously. */ |
| 129 | struct audit_buffer { |
| 130 | struct list_head list; |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 131 | struct sk_buff *skb; /* formatted skb ready to send */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | struct audit_context *ctx; /* NULL or associated context */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | }; |
| 134 | |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 135 | static void audit_set_pid(struct audit_buffer *ab, pid_t pid) |
| 136 | { |
| 137 | struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data; |
| 138 | nlh->nlmsg_pid = pid; |
| 139 | } |
| 140 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | struct audit_entry { |
| 142 | struct list_head list; |
| 143 | struct audit_rule rule; |
| 144 | }; |
| 145 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 146 | static void audit_panic(const char *message) |
| 147 | { |
| 148 | switch (audit_failure) |
| 149 | { |
| 150 | case AUDIT_FAIL_SILENT: |
| 151 | break; |
| 152 | case AUDIT_FAIL_PRINTK: |
| 153 | printk(KERN_ERR "audit: %s\n", message); |
| 154 | break; |
| 155 | case AUDIT_FAIL_PANIC: |
| 156 | panic("audit: %s\n", message); |
| 157 | break; |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | static inline int audit_rate_check(void) |
| 162 | { |
| 163 | static unsigned long last_check = 0; |
| 164 | static int messages = 0; |
| 165 | static DEFINE_SPINLOCK(lock); |
| 166 | unsigned long flags; |
| 167 | unsigned long now; |
| 168 | unsigned long elapsed; |
| 169 | int retval = 0; |
| 170 | |
| 171 | if (!audit_rate_limit) return 1; |
| 172 | |
| 173 | spin_lock_irqsave(&lock, flags); |
| 174 | if (++messages < audit_rate_limit) { |
| 175 | retval = 1; |
| 176 | } else { |
| 177 | now = jiffies; |
| 178 | elapsed = now - last_check; |
| 179 | if (elapsed > HZ) { |
| 180 | last_check = now; |
| 181 | messages = 0; |
| 182 | retval = 1; |
| 183 | } |
| 184 | } |
| 185 | spin_unlock_irqrestore(&lock, flags); |
| 186 | |
| 187 | return retval; |
| 188 | } |
| 189 | |
| 190 | /* Emit at least 1 message per second, even if audit_rate_check is |
| 191 | * throttling. */ |
| 192 | void audit_log_lost(const char *message) |
| 193 | { |
| 194 | static unsigned long last_msg = 0; |
| 195 | static DEFINE_SPINLOCK(lock); |
| 196 | unsigned long flags; |
| 197 | unsigned long now; |
| 198 | int print; |
| 199 | |
| 200 | atomic_inc(&audit_lost); |
| 201 | |
| 202 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); |
| 203 | |
| 204 | if (!print) { |
| 205 | spin_lock_irqsave(&lock, flags); |
| 206 | now = jiffies; |
| 207 | if (now - last_msg > HZ) { |
| 208 | print = 1; |
| 209 | last_msg = now; |
| 210 | } |
| 211 | spin_unlock_irqrestore(&lock, flags); |
| 212 | } |
| 213 | |
| 214 | if (print) { |
| 215 | printk(KERN_WARNING |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 216 | "audit: audit_lost=%d audit_rate_limit=%d audit_backlog_limit=%d\n", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 217 | atomic_read(&audit_lost), |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | audit_rate_limit, |
| 219 | audit_backlog_limit); |
| 220 | audit_panic(message); |
| 221 | } |
| 222 | |
| 223 | } |
| 224 | |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 225 | static int audit_set_rate_limit(int limit, uid_t loginuid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 226 | { |
| 227 | int old = audit_rate_limit; |
| 228 | audit_rate_limit = limit; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 229 | audit_log(NULL, AUDIT_CONFIG_CHANGE, |
David Woodhouse | bccf6ae | 2005-05-23 21:35:28 +0100 | [diff] [blame] | 230 | "audit_rate_limit=%d old=%d by auid=%u", |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 231 | audit_rate_limit, old, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 232 | return old; |
| 233 | } |
| 234 | |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 235 | static int audit_set_backlog_limit(int limit, uid_t loginuid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | { |
| 237 | int old = audit_backlog_limit; |
| 238 | audit_backlog_limit = limit; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 239 | audit_log(NULL, AUDIT_CONFIG_CHANGE, |
David Woodhouse | bccf6ae | 2005-05-23 21:35:28 +0100 | [diff] [blame] | 240 | "audit_backlog_limit=%d old=%d by auid=%u", |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 241 | audit_backlog_limit, old, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | return old; |
| 243 | } |
| 244 | |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 245 | static int audit_set_enabled(int state, uid_t loginuid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 246 | { |
| 247 | int old = audit_enabled; |
| 248 | if (state != 0 && state != 1) |
| 249 | return -EINVAL; |
| 250 | audit_enabled = state; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 251 | audit_log(NULL, AUDIT_CONFIG_CHANGE, |
David Woodhouse | bccf6ae | 2005-05-23 21:35:28 +0100 | [diff] [blame] | 252 | "audit_enabled=%d old=%d by auid=%u", |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 253 | audit_enabled, old, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 254 | return old; |
| 255 | } |
| 256 | |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 257 | static int audit_set_failure(int state, uid_t loginuid) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 258 | { |
| 259 | int old = audit_failure; |
| 260 | if (state != AUDIT_FAIL_SILENT |
| 261 | && state != AUDIT_FAIL_PRINTK |
| 262 | && state != AUDIT_FAIL_PANIC) |
| 263 | return -EINVAL; |
| 264 | audit_failure = state; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 265 | audit_log(NULL, AUDIT_CONFIG_CHANGE, |
David Woodhouse | bccf6ae | 2005-05-23 21:35:28 +0100 | [diff] [blame] | 266 | "audit_failure=%d old=%d by auid=%u", |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 267 | audit_failure, old, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 268 | return old; |
| 269 | } |
| 270 | |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 271 | int kauditd_thread(void *dummy) |
| 272 | { |
| 273 | struct sk_buff *skb; |
| 274 | |
| 275 | while (1) { |
| 276 | skb = skb_dequeue(&audit_skb_queue); |
| 277 | if (skb) { |
| 278 | if (audit_pid) { |
| 279 | int err = netlink_unicast(audit_sock, skb, audit_pid, 0); |
| 280 | if (err < 0) { |
| 281 | BUG_ON(err != -ECONNREFUSED); /* Shoudn't happen */ |
| 282 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
| 283 | audit_pid = 0; |
| 284 | } |
| 285 | } else { |
| 286 | printk(KERN_ERR "%s\n", skb->data + NLMSG_SPACE(0)); |
| 287 | kfree_skb(skb); |
| 288 | } |
| 289 | } else { |
| 290 | DECLARE_WAITQUEUE(wait, current); |
| 291 | set_current_state(TASK_INTERRUPTIBLE); |
| 292 | add_wait_queue(&kauditd_wait, &wait); |
| 293 | |
| 294 | if (!skb_queue_len(&audit_skb_queue)) |
| 295 | schedule(); |
| 296 | |
| 297 | __set_current_state(TASK_RUNNING); |
| 298 | remove_wait_queue(&kauditd_wait, &wait); |
| 299 | } |
| 300 | } |
| 301 | } |
| 302 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 303 | void audit_send_reply(int pid, int seq, int type, int done, int multi, |
| 304 | void *payload, int size) |
| 305 | { |
| 306 | struct sk_buff *skb; |
| 307 | struct nlmsghdr *nlh; |
| 308 | int len = NLMSG_SPACE(size); |
| 309 | void *data; |
| 310 | int flags = multi ? NLM_F_MULTI : 0; |
| 311 | int t = done ? NLMSG_DONE : type; |
| 312 | |
| 313 | skb = alloc_skb(len, GFP_KERNEL); |
| 314 | if (!skb) |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 315 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 316 | |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 317 | nlh = NLMSG_PUT(skb, pid, seq, t, size); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 318 | nlh->nlmsg_flags = flags; |
| 319 | data = NLMSG_DATA(nlh); |
| 320 | memcpy(data, payload, size); |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 321 | |
| 322 | /* Ignore failure. It'll only happen if the sender goes away, |
| 323 | because our timeout is set to infinite. */ |
| 324 | netlink_unicast(audit_sock, skb, pid, 0); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 325 | return; |
| 326 | |
| 327 | nlmsg_failure: /* Used by NLMSG_PUT */ |
| 328 | if (skb) |
| 329 | kfree_skb(skb); |
| 330 | } |
| 331 | |
| 332 | /* |
| 333 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit |
| 334 | * control messages. |
| 335 | */ |
| 336 | static int audit_netlink_ok(kernel_cap_t eff_cap, u16 msg_type) |
| 337 | { |
| 338 | int err = 0; |
| 339 | |
| 340 | switch (msg_type) { |
| 341 | case AUDIT_GET: |
| 342 | case AUDIT_LIST: |
| 343 | case AUDIT_SET: |
| 344 | case AUDIT_ADD: |
| 345 | case AUDIT_DEL: |
Steve Grubb | c2f0c7c | 2005-05-06 12:38:39 +0100 | [diff] [blame] | 346 | case AUDIT_SIGNAL_INFO: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 347 | if (!cap_raised(eff_cap, CAP_AUDIT_CONTROL)) |
| 348 | err = -EPERM; |
| 349 | break; |
Steve Grubb | 0547410 | 2005-05-21 00:18:37 +0100 | [diff] [blame] | 350 | case AUDIT_USER: |
David Woodhouse | 209aba0 | 2005-05-18 10:21:07 +0100 | [diff] [blame] | 351 | case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 352 | if (!cap_raised(eff_cap, CAP_AUDIT_WRITE)) |
| 353 | err = -EPERM; |
| 354 | break; |
| 355 | default: /* bad msg */ |
| 356 | err = -EINVAL; |
| 357 | } |
| 358 | |
| 359 | return err; |
| 360 | } |
| 361 | |
| 362 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
| 363 | { |
| 364 | u32 uid, pid, seq; |
| 365 | void *data; |
| 366 | struct audit_status *status_get, status_set; |
| 367 | int err; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 368 | struct audit_buffer *ab; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 369 | u16 msg_type = nlh->nlmsg_type; |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 370 | uid_t loginuid; /* loginuid of sender */ |
Steve Grubb | c2f0c7c | 2005-05-06 12:38:39 +0100 | [diff] [blame] | 371 | struct audit_sig_info sig_data; |
David Woodhouse | 0f45aa1 | 2005-06-19 19:35:50 +0100 | [diff] [blame^] | 372 | struct task_struct *tsk; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 373 | |
| 374 | err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type); |
| 375 | if (err) |
| 376 | return err; |
| 377 | |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 378 | /* As soon as there's any sign of userspace auditd, start kauditd to talk to it */ |
| 379 | if (!kauditd_task) |
| 380 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
| 381 | if (IS_ERR(kauditd_task)) { |
| 382 | err = PTR_ERR(kauditd_task); |
| 383 | kauditd_task = NULL; |
| 384 | return err; |
| 385 | } |
| 386 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 387 | pid = NETLINK_CREDS(skb)->pid; |
| 388 | uid = NETLINK_CREDS(skb)->uid; |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 389 | loginuid = NETLINK_CB(skb).loginuid; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 390 | seq = nlh->nlmsg_seq; |
| 391 | data = NLMSG_DATA(nlh); |
| 392 | |
| 393 | switch (msg_type) { |
| 394 | case AUDIT_GET: |
| 395 | status_set.enabled = audit_enabled; |
| 396 | status_set.failure = audit_failure; |
| 397 | status_set.pid = audit_pid; |
| 398 | status_set.rate_limit = audit_rate_limit; |
| 399 | status_set.backlog_limit = audit_backlog_limit; |
| 400 | status_set.lost = atomic_read(&audit_lost); |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 401 | status_set.backlog = skb_queue_len(&audit_skb_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 402 | audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0, |
| 403 | &status_set, sizeof(status_set)); |
| 404 | break; |
| 405 | case AUDIT_SET: |
| 406 | if (nlh->nlmsg_len < sizeof(struct audit_status)) |
| 407 | return -EINVAL; |
| 408 | status_get = (struct audit_status *)data; |
| 409 | if (status_get->mask & AUDIT_STATUS_ENABLED) { |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 410 | err = audit_set_enabled(status_get->enabled, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | if (err < 0) return err; |
| 412 | } |
| 413 | if (status_get->mask & AUDIT_STATUS_FAILURE) { |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 414 | err = audit_set_failure(status_get->failure, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 415 | if (err < 0) return err; |
| 416 | } |
| 417 | if (status_get->mask & AUDIT_STATUS_PID) { |
| 418 | int old = audit_pid; |
| 419 | audit_pid = status_get->pid; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 420 | audit_log(NULL, AUDIT_CONFIG_CHANGE, |
David Woodhouse | bccf6ae | 2005-05-23 21:35:28 +0100 | [diff] [blame] | 421 | "audit_pid=%d old=%d by auid=%u", |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 422 | audit_pid, old, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | } |
| 424 | if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 425 | audit_set_rate_limit(status_get->rate_limit, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 426 | if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 427 | audit_set_backlog_limit(status_get->backlog_limit, |
| 428 | loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | break; |
Steve Grubb | 0547410 | 2005-05-21 00:18:37 +0100 | [diff] [blame] | 430 | case AUDIT_USER: |
David Woodhouse | 209aba0 | 2005-05-18 10:21:07 +0100 | [diff] [blame] | 431 | case AUDIT_FIRST_USER_MSG...AUDIT_LAST_USER_MSG: |
David Woodhouse | 0f45aa1 | 2005-06-19 19:35:50 +0100 | [diff] [blame^] | 432 | read_lock(&tasklist_lock); |
| 433 | tsk = find_task_by_pid(pid); |
| 434 | if (tsk) |
| 435 | get_task_struct(tsk); |
| 436 | read_unlock(&tasklist_lock); |
| 437 | if (!tsk) |
| 438 | return -ESRCH; |
| 439 | |
| 440 | if (audit_filter_user(tsk, msg_type)) { |
| 441 | ab = audit_log_start(NULL, msg_type); |
| 442 | if (ab) { |
| 443 | audit_log_format(ab, |
| 444 | "user pid=%d uid=%u auid=%u msg='%.1024s'", |
| 445 | pid, uid, loginuid, (char *)data); |
| 446 | audit_set_pid(ab, pid); |
| 447 | audit_log_end(ab); |
| 448 | } |
| 449 | } |
| 450 | put_task_struct(tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 451 | break; |
| 452 | case AUDIT_ADD: |
| 453 | case AUDIT_DEL: |
| 454 | if (nlh->nlmsg_len < sizeof(struct audit_rule)) |
| 455 | return -EINVAL; |
| 456 | /* fallthrough */ |
| 457 | case AUDIT_LIST: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 458 | err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid, |
Serge Hallyn | c94c257 | 2005-04-29 16:27:17 +0100 | [diff] [blame] | 459 | uid, seq, data, loginuid); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 460 | break; |
Steve Grubb | c2f0c7c | 2005-05-06 12:38:39 +0100 | [diff] [blame] | 461 | case AUDIT_SIGNAL_INFO: |
| 462 | sig_data.uid = audit_sig_uid; |
| 463 | sig_data.pid = audit_sig_pid; |
| 464 | audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, |
| 465 | 0, 0, &sig_data, sizeof(sig_data)); |
| 466 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 467 | default: |
| 468 | err = -EINVAL; |
| 469 | break; |
| 470 | } |
| 471 | |
| 472 | return err < 0 ? err : 0; |
| 473 | } |
| 474 | |
| 475 | /* Get message from skb (based on rtnetlink_rcv_skb). Each message is |
| 476 | * processed by audit_receive_msg. Malformed skbs with wrong length are |
| 477 | * discarded silently. */ |
Herbert Xu | 2a0a6eb | 2005-05-03 14:55:09 -0700 | [diff] [blame] | 478 | static void audit_receive_skb(struct sk_buff *skb) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 479 | { |
| 480 | int err; |
| 481 | struct nlmsghdr *nlh; |
| 482 | u32 rlen; |
| 483 | |
| 484 | while (skb->len >= NLMSG_SPACE(0)) { |
| 485 | nlh = (struct nlmsghdr *)skb->data; |
| 486 | if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) |
Herbert Xu | 2a0a6eb | 2005-05-03 14:55:09 -0700 | [diff] [blame] | 487 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 488 | rlen = NLMSG_ALIGN(nlh->nlmsg_len); |
| 489 | if (rlen > skb->len) |
| 490 | rlen = skb->len; |
| 491 | if ((err = audit_receive_msg(skb, nlh))) { |
| 492 | netlink_ack(skb, nlh, err); |
| 493 | } else if (nlh->nlmsg_flags & NLM_F_ACK) |
| 494 | netlink_ack(skb, nlh, 0); |
| 495 | skb_pull(skb, rlen); |
| 496 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 497 | } |
| 498 | |
| 499 | /* Receive messages from netlink socket. */ |
| 500 | static void audit_receive(struct sock *sk, int length) |
| 501 | { |
| 502 | struct sk_buff *skb; |
Herbert Xu | 2a0a6eb | 2005-05-03 14:55:09 -0700 | [diff] [blame] | 503 | unsigned int qlen; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 504 | |
Herbert Xu | 2a0a6eb | 2005-05-03 14:55:09 -0700 | [diff] [blame] | 505 | down(&audit_netlink_sem); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | |
Herbert Xu | 2a0a6eb | 2005-05-03 14:55:09 -0700 | [diff] [blame] | 507 | for (qlen = skb_queue_len(&sk->sk_receive_queue); qlen; qlen--) { |
| 508 | skb = skb_dequeue(&sk->sk_receive_queue); |
| 509 | audit_receive_skb(skb); |
| 510 | kfree_skb(skb); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 511 | } |
| 512 | up(&audit_netlink_sem); |
| 513 | } |
| 514 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | |
| 516 | /* Initialize audit support at boot time. */ |
| 517 | static int __init audit_init(void) |
| 518 | { |
| 519 | printk(KERN_INFO "audit: initializing netlink socket (%s)\n", |
| 520 | audit_default ? "enabled" : "disabled"); |
| 521 | audit_sock = netlink_kernel_create(NETLINK_AUDIT, audit_receive); |
| 522 | if (!audit_sock) |
| 523 | audit_panic("cannot initialize netlink socket"); |
| 524 | |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 525 | audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; |
| 526 | skb_queue_head_init(&audit_skb_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | audit_initialized = 1; |
| 528 | audit_enabled = audit_default; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 529 | audit_log(NULL, AUDIT_KERNEL, "initialized"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 530 | return 0; |
| 531 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 532 | __initcall(audit_init); |
| 533 | |
| 534 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ |
| 535 | static int __init audit_enable(char *str) |
| 536 | { |
| 537 | audit_default = !!simple_strtol(str, NULL, 0); |
| 538 | printk(KERN_INFO "audit: %s%s\n", |
| 539 | audit_default ? "enabled" : "disabled", |
| 540 | audit_initialized ? "" : " (after initialization)"); |
| 541 | if (audit_initialized) |
| 542 | audit_enabled = audit_default; |
| 543 | return 0; |
| 544 | } |
| 545 | |
| 546 | __setup("audit=", audit_enable); |
| 547 | |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 548 | static void audit_buffer_free(struct audit_buffer *ab) |
| 549 | { |
| 550 | unsigned long flags; |
| 551 | |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 552 | if (!ab) |
| 553 | return; |
| 554 | |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 555 | if (ab->skb) |
| 556 | kfree_skb(ab->skb); |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 557 | |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 558 | spin_lock_irqsave(&audit_freelist_lock, flags); |
| 559 | if (++audit_freelist_count > AUDIT_MAXFREE) |
| 560 | kfree(ab); |
| 561 | else |
| 562 | list_add(&ab->list, &audit_freelist); |
| 563 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
| 564 | } |
| 565 | |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 566 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
| 567 | int gfp_mask, int type) |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 568 | { |
| 569 | unsigned long flags; |
| 570 | struct audit_buffer *ab = NULL; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 571 | struct nlmsghdr *nlh; |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 572 | |
| 573 | spin_lock_irqsave(&audit_freelist_lock, flags); |
| 574 | if (!list_empty(&audit_freelist)) { |
| 575 | ab = list_entry(audit_freelist.next, |
| 576 | struct audit_buffer, list); |
| 577 | list_del(&ab->list); |
| 578 | --audit_freelist_count; |
| 579 | } |
| 580 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
| 581 | |
| 582 | if (!ab) { |
David Woodhouse | 4332bdd | 2005-05-06 15:59:57 +0100 | [diff] [blame] | 583 | ab = kmalloc(sizeof(*ab), gfp_mask); |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 584 | if (!ab) |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 585 | goto err; |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 586 | } |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 587 | |
David Woodhouse | 4332bdd | 2005-05-06 15:59:57 +0100 | [diff] [blame] | 588 | ab->skb = alloc_skb(AUDIT_BUFSIZ, gfp_mask); |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 589 | if (!ab->skb) |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 590 | goto err; |
| 591 | |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 592 | ab->ctx = ctx; |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 593 | nlh = (struct nlmsghdr *)skb_put(ab->skb, NLMSG_SPACE(0)); |
| 594 | nlh->nlmsg_type = type; |
| 595 | nlh->nlmsg_flags = 0; |
| 596 | nlh->nlmsg_pid = 0; |
| 597 | nlh->nlmsg_seq = 0; |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 598 | return ab; |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 599 | err: |
| 600 | audit_buffer_free(ab); |
| 601 | return NULL; |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 602 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 603 | |
David Woodhouse | bfb4496 | 2005-05-21 21:08:09 +0100 | [diff] [blame] | 604 | /* Compute a serial number for the audit record. Audit records are |
| 605 | * written to user-space as soon as they are generated, so a complete |
| 606 | * audit record may be written in several pieces. The timestamp of the |
| 607 | * record and this serial number are used by the user-space tools to |
| 608 | * determine which pieces belong to the same audit record. The |
| 609 | * (timestamp,serial) tuple is unique for each syscall and is live from |
| 610 | * syscall entry to syscall exit. |
| 611 | * |
| 612 | * Atomic values are only guaranteed to be 24-bit, so we count down. |
| 613 | * |
| 614 | * NOTE: Another possibility is to store the formatted records off the |
| 615 | * audit context (for those records that have a context), and emit them |
| 616 | * all at syscall exit. However, this could delay the reporting of |
| 617 | * significant errors until syscall exit (or never, if the system |
| 618 | * halts). */ |
| 619 | unsigned int audit_serial(void) |
| 620 | { |
| 621 | static atomic_t serial = ATOMIC_INIT(0xffffff); |
| 622 | unsigned int a, b; |
| 623 | |
| 624 | do { |
| 625 | a = atomic_read(&serial); |
| 626 | if (atomic_dec_and_test(&serial)) |
| 627 | atomic_set(&serial, 0xffffff); |
| 628 | b = atomic_read(&serial); |
| 629 | } while (b != a - 1); |
| 630 | |
| 631 | return 0xffffff - b; |
| 632 | } |
| 633 | |
| 634 | static inline void audit_get_stamp(struct audit_context *ctx, |
| 635 | struct timespec *t, unsigned int *serial) |
| 636 | { |
| 637 | if (ctx) |
| 638 | auditsc_get_stamp(ctx, t, serial); |
| 639 | else { |
| 640 | *t = CURRENT_TIME; |
| 641 | *serial = audit_serial(); |
| 642 | } |
| 643 | } |
| 644 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 645 | /* Obtain an audit buffer. This routine does locking to obtain the |
| 646 | * audit buffer, but then no locking is required for calls to |
| 647 | * audit_log_*format. If the tsk is a task that is currently in a |
| 648 | * syscall, then the syscall is marked as auditable and an audit record |
| 649 | * will be written at syscall exit. If there is no associated task, tsk |
| 650 | * should be NULL. */ |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 651 | struct audit_buffer *audit_log_start(struct audit_context *ctx, int type) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 652 | { |
| 653 | struct audit_buffer *ab = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 654 | struct timespec t; |
Steve Grubb | d812ddb | 2005-04-29 16:09:52 +0100 | [diff] [blame] | 655 | unsigned int serial; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 656 | |
| 657 | if (!audit_initialized) |
| 658 | return NULL; |
| 659 | |
David Woodhouse | fb19b4c | 2005-05-19 14:55:56 +0100 | [diff] [blame] | 660 | if (audit_backlog_limit |
| 661 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit) { |
| 662 | if (audit_rate_check()) |
| 663 | printk(KERN_WARNING |
| 664 | "audit: audit_backlog=%d > " |
| 665 | "audit_backlog_limit=%d\n", |
| 666 | skb_queue_len(&audit_skb_queue), |
| 667 | audit_backlog_limit); |
| 668 | audit_log_lost("backlog limit exceeded"); |
| 669 | return NULL; |
| 670 | } |
| 671 | |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 672 | ab = audit_buffer_alloc(ctx, GFP_ATOMIC, type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 673 | if (!ab) { |
| 674 | audit_log_lost("out of memory in audit_log_start"); |
| 675 | return NULL; |
| 676 | } |
| 677 | |
David Woodhouse | bfb4496 | 2005-05-21 21:08:09 +0100 | [diff] [blame] | 678 | audit_get_stamp(ab->ctx, &t, &serial); |
Chris Wright | 197c69c | 2005-05-11 10:54:05 +0100 | [diff] [blame] | 679 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 680 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
| 681 | t.tv_sec, t.tv_nsec/1000000, serial); |
| 682 | return ab; |
| 683 | } |
| 684 | |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 685 | /** |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 686 | * audit_expand - expand skb in the audit buffer |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 687 | * @ab: audit_buffer |
| 688 | * |
| 689 | * Returns 0 (no space) on failed expansion, or available space if |
| 690 | * successful. |
| 691 | */ |
David Woodhouse | e3b926b | 2005-05-10 18:56:08 +0100 | [diff] [blame] | 692 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 693 | { |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 694 | struct sk_buff *skb = ab->skb; |
David Woodhouse | e3b926b | 2005-05-10 18:56:08 +0100 | [diff] [blame] | 695 | int ret = pskb_expand_head(skb, skb_headroom(skb), extra, |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 696 | GFP_ATOMIC); |
| 697 | if (ret < 0) { |
| 698 | audit_log_lost("out of memory in audit_expand"); |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 699 | return 0; |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 700 | } |
| 701 | return skb_tailroom(skb); |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 702 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 703 | |
| 704 | /* Format an audit message into the audit buffer. If there isn't enough |
| 705 | * room in the audit buffer, more room will be allocated and vsnprint |
| 706 | * will be called a second time. Currently, we assume that a printk |
| 707 | * can't format message larger than 1024 bytes, so we don't either. */ |
| 708 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
| 709 | va_list args) |
| 710 | { |
| 711 | int len, avail; |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 712 | struct sk_buff *skb; |
David Woodhouse | eecb0a7 | 2005-05-10 18:58:51 +0100 | [diff] [blame] | 713 | va_list args2; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 714 | |
| 715 | if (!ab) |
| 716 | return; |
| 717 | |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 718 | BUG_ON(!ab->skb); |
| 719 | skb = ab->skb; |
| 720 | avail = skb_tailroom(skb); |
| 721 | if (avail == 0) { |
David Woodhouse | e3b926b | 2005-05-10 18:56:08 +0100 | [diff] [blame] | 722 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 723 | if (!avail) |
| 724 | goto out; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 725 | } |
David Woodhouse | eecb0a7 | 2005-05-10 18:58:51 +0100 | [diff] [blame] | 726 | va_copy(args2, args); |
Chris Wright | 5ac52f3 | 2005-05-06 15:54:53 +0100 | [diff] [blame] | 727 | len = vsnprintf(skb->tail, avail, fmt, args); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 728 | if (len >= avail) { |
| 729 | /* The printk buffer is 1024 bytes long, so if we get |
| 730 | * here and AUDIT_BUFSIZ is at least 1024, then we can |
| 731 | * log everything that printk could have logged. */ |
David Woodhouse | 5e014b1 | 2005-05-13 18:50:33 +0100 | [diff] [blame] | 732 | avail = audit_expand(ab, max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 733 | if (!avail) |
| 734 | goto out; |
David Woodhouse | eecb0a7 | 2005-05-10 18:58:51 +0100 | [diff] [blame] | 735 | len = vsnprintf(skb->tail, avail, fmt, args2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 736 | } |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 737 | if (len > 0) |
| 738 | skb_put(skb, len); |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 739 | out: |
| 740 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 741 | } |
| 742 | |
| 743 | /* Format a message into the audit buffer. All the work is done in |
| 744 | * audit_log_vformat. */ |
| 745 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
| 746 | { |
| 747 | va_list args; |
| 748 | |
| 749 | if (!ab) |
| 750 | return; |
| 751 | va_start(args, fmt); |
| 752 | audit_log_vformat(ab, fmt, args); |
| 753 | va_end(args); |
| 754 | } |
| 755 | |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 756 | /* This function will take the passed buf and convert it into a string of |
| 757 | * ascii hex digits. The new string is placed onto the skb. */ |
| 758 | void audit_log_hex(struct audit_buffer *ab, const unsigned char *buf, |
| 759 | size_t len) |
| 83c7d09 | 2005-04-29 15:54:44 +0100 | [diff] [blame] | 760 | { |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 761 | int i, avail, new_len; |
| 762 | unsigned char *ptr; |
| 763 | struct sk_buff *skb; |
| 764 | static const unsigned char *hex = "0123456789ABCDEF"; |
| 83c7d09 | 2005-04-29 15:54:44 +0100 | [diff] [blame] | 765 | |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 766 | BUG_ON(!ab->skb); |
| 767 | skb = ab->skb; |
| 768 | avail = skb_tailroom(skb); |
| 769 | new_len = len<<1; |
| 770 | if (new_len >= avail) { |
| 771 | /* Round the buffer request up to the next multiple */ |
| 772 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); |
| 773 | avail = audit_expand(ab, new_len); |
| 774 | if (!avail) |
| 775 | return; |
| 776 | } |
| 777 | |
| 778 | ptr = skb->tail; |
| 779 | for (i=0; i<len; i++) { |
| 780 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ |
| 781 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ |
| 782 | } |
| 783 | *ptr = 0; |
| 784 | skb_put(skb, len << 1); /* new string is twice the old string */ |
| 83c7d09 | 2005-04-29 15:54:44 +0100 | [diff] [blame] | 785 | } |
| 786 | |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 787 | /* This code will escape a string that is passed to it if the string |
| 788 | * contains a control character, unprintable character, double quote mark, |
| 789 | * or a space. Unescaped strings will start and end with a double quote mark. |
| 790 | * Strings that are escaped are printed in hex (2 digits per char). */ |
| 83c7d09 | 2005-04-29 15:54:44 +0100 | [diff] [blame] | 791 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
| 792 | { |
Andrew Morton | 81b7854 | 2005-04-29 15:59:11 +0100 | [diff] [blame] | 793 | const unsigned char *p = string; |
| 83c7d09 | 2005-04-29 15:54:44 +0100 | [diff] [blame] | 794 | |
| 795 | while (*p) { |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 796 | if (*p == '"' || *p < 0x21 || *p > 0x7f) { |
| 83c7d09 | 2005-04-29 15:54:44 +0100 | [diff] [blame] | 797 | audit_log_hex(ab, string, strlen(string)); |
| 798 | return; |
| 799 | } |
| 800 | p++; |
| 801 | } |
| 802 | audit_log_format(ab, "\"%s\"", string); |
| 803 | } |
| 804 | |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 805 | /* This is a helper-function to print the escaped d_path */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 806 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
| 807 | struct dentry *dentry, struct vfsmount *vfsmnt) |
| 808 | { |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 809 | char *p, *path; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 810 | |
Chris Wright | 8fc6115 | 2005-05-06 15:54:17 +0100 | [diff] [blame] | 811 | if (prefix) |
| 812 | audit_log_format(ab, " %s", prefix); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 813 | |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 814 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
| 815 | path = kmalloc(PATH_MAX+11, GFP_KERNEL); |
| 816 | if (!path) { |
| 817 | audit_log_format(ab, "<no memory>"); |
| 818 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 819 | } |
Steve Grubb | 168b717 | 2005-05-19 10:24:22 +0100 | [diff] [blame] | 820 | p = d_path(dentry, vfsmnt, path, PATH_MAX+11); |
| 821 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
| 822 | /* FIXME: can we save some information here? */ |
| 823 | audit_log_format(ab, "<too long>"); |
| 824 | } else |
| 825 | audit_log_untrustedstring(ab, p); |
| 826 | kfree(path); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | } |
| 828 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 829 | /* The netlink_* functions cannot be called inside an irq context, so |
| 830 | * the audit buffer is places on a queue and a tasklet is scheduled to |
| 831 | * remove them from the queue outside the irq context. May be called in |
| 832 | * any context. */ |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 833 | void audit_log_end(struct audit_buffer *ab) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 834 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 835 | if (!ab) |
| 836 | return; |
| 837 | if (!audit_rate_check()) { |
| 838 | audit_log_lost("rate limit exceeded"); |
| 839 | } else { |
David Woodhouse | b7d1125 | 2005-05-19 10:56:58 +0100 | [diff] [blame] | 840 | if (audit_pid) { |
| 841 | struct nlmsghdr *nlh = (struct nlmsghdr *)ab->skb->data; |
| 842 | nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); |
| 843 | skb_queue_tail(&audit_skb_queue, ab->skb); |
| 844 | ab->skb = NULL; |
| 845 | wake_up_interruptible(&kauditd_wait); |
| 846 | } else { |
| 847 | printk("%s\n", ab->skb->data + NLMSG_SPACE(0)); |
| 848 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 849 | } |
Chris Wright | 16e1904 | 2005-05-06 15:53:34 +0100 | [diff] [blame] | 850 | audit_buffer_free(ab); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 851 | } |
| 852 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 853 | /* Log an audit record. This is a convenience function that calls |
| 854 | * audit_log_start, audit_log_vformat, and audit_log_end. It may be |
| 855 | * called in any context. */ |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 856 | void audit_log(struct audit_context *ctx, int type, const char *fmt, ...) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 857 | { |
| 858 | struct audit_buffer *ab; |
| 859 | va_list args; |
| 860 | |
Steve Grubb | c040499 | 2005-05-13 18:17:42 +0100 | [diff] [blame] | 861 | ab = audit_log_start(ctx, type); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 862 | if (ab) { |
| 863 | va_start(args, fmt); |
| 864 | audit_log_vformat(ab, fmt, args); |
| 865 | va_end(args); |
| 866 | audit_log_end(ab); |
| 867 | } |
| 868 | } |