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Tetsuo Handaeadd99c2011-06-26 23:18:58 +09001/*
2 * security/tomoyo/audit.c
3 *
Tetsuo Handa0f2a55d2011-07-14 14:46:51 +09004 * Copyright (C) 2005-2011 NTT DATA CORPORATION
Tetsuo Handaeadd99c2011-06-26 23:18:58 +09005 */
6
7#include "common.h"
8#include <linux/slab.h>
9
10/**
Tetsuo Handa5b636852011-07-08 13:24:54 +090011 * tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
12 *
13 * @bprm: Pointer to "struct linux_binprm".
14 * @dump: Pointer to "struct tomoyo_page_dump".
15 *
16 * Returns the contents of @bprm on success, NULL otherwise.
17 *
18 * This function uses kzalloc(), so caller must kfree() if this function
19 * didn't return NULL.
20 */
21static char *tomoyo_print_bprm(struct linux_binprm *bprm,
22 struct tomoyo_page_dump *dump)
23{
24 static const int tomoyo_buffer_len = 4096 * 2;
25 char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
26 char *cp;
27 char *last_start;
28 int len;
29 unsigned long pos = bprm->p;
30 int offset = pos % PAGE_SIZE;
31 int argv_count = bprm->argc;
32 int envp_count = bprm->envc;
33 bool truncated = false;
34 if (!buffer)
35 return NULL;
36 len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
37 cp = buffer + len;
38 if (!argv_count) {
39 memmove(cp, "} envp[]={ ", 11);
40 cp += 11;
41 }
42 last_start = cp;
43 while (argv_count || envp_count) {
44 if (!tomoyo_dump_page(bprm, pos, dump))
45 goto out;
46 pos += PAGE_SIZE - offset;
47 /* Read. */
48 while (offset < PAGE_SIZE) {
49 const char *kaddr = dump->data;
50 const unsigned char c = kaddr[offset++];
51 if (cp == last_start)
52 *cp++ = '"';
53 if (cp >= buffer + tomoyo_buffer_len - 32) {
54 /* Reserve some room for "..." string. */
55 truncated = true;
56 } else if (c == '\\') {
57 *cp++ = '\\';
58 *cp++ = '\\';
59 } else if (c > ' ' && c < 127) {
60 *cp++ = c;
61 } else if (!c) {
62 *cp++ = '"';
63 *cp++ = ' ';
64 last_start = cp;
65 } else {
66 *cp++ = '\\';
67 *cp++ = (c >> 6) + '0';
68 *cp++ = ((c >> 3) & 7) + '0';
69 *cp++ = (c & 7) + '0';
70 }
71 if (c)
72 continue;
73 if (argv_count) {
74 if (--argv_count == 0) {
75 if (truncated) {
76 cp = last_start;
77 memmove(cp, "... ", 4);
78 cp += 4;
79 }
80 memmove(cp, "} envp[]={ ", 11);
81 cp += 11;
82 last_start = cp;
83 truncated = false;
84 }
85 } else if (envp_count) {
86 if (--envp_count == 0) {
87 if (truncated) {
88 cp = last_start;
89 memmove(cp, "... ", 4);
90 cp += 4;
91 }
92 }
93 }
94 if (!argv_count && !envp_count)
95 break;
96 }
97 offset = 0;
98 }
99 *cp++ = '}';
100 *cp = '\0';
101 return buffer;
102out:
103 snprintf(buffer, tomoyo_buffer_len - 1,
104 "argv[]={ ... } envp[]= { ... }");
105 return buffer;
106}
107
108/**
Tetsuo Handa8761afd2011-07-08 13:22:41 +0900109 * tomoyo_filetype - Get string representation of file type.
110 *
111 * @mode: Mode value for stat().
112 *
113 * Returns file type string.
114 */
115static inline const char *tomoyo_filetype(const mode_t mode)
116{
117 switch (mode & S_IFMT) {
118 case S_IFREG:
119 case 0:
120 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE];
121 case S_IFDIR:
122 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY];
123 case S_IFLNK:
124 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK];
125 case S_IFIFO:
126 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO];
127 case S_IFSOCK:
128 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET];
129 case S_IFBLK:
130 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV];
131 case S_IFCHR:
132 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV];
133 }
134 return "unknown"; /* This should not happen. */
135}
136
137/**
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900138 * tomoyo_print_header - Get header line of audit log.
139 *
140 * @r: Pointer to "struct tomoyo_request_info".
141 *
142 * Returns string representation.
143 *
144 * This function uses kmalloc(), so caller must kfree() if this function
145 * didn't return NULL.
146 */
147static char *tomoyo_print_header(struct tomoyo_request_info *r)
148{
149 struct tomoyo_time stamp;
150 const pid_t gpid = task_pid_nr(current);
Tetsuo Handa8761afd2011-07-08 13:22:41 +0900151 struct tomoyo_obj_info *obj = r->obj;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900152 static const int tomoyo_buffer_len = 4096;
153 char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
Tetsuo Handa2066a362011-07-08 13:21:37 +0900154 int pos;
Tetsuo Handa8761afd2011-07-08 13:22:41 +0900155 u8 i;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900156 if (!buffer)
157 return NULL;
158 {
159 struct timeval tv;
160 do_gettimeofday(&tv);
161 tomoyo_convert_time(tv.tv_sec, &stamp);
162 }
Tetsuo Handa2066a362011-07-08 13:21:37 +0900163 pos = snprintf(buffer, tomoyo_buffer_len - 1,
164 "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
165 "granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
166 "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
167 "fsuid=%u fsgid=%u }", stamp.year, stamp.month,
168 stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile,
169 tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid,
170 tomoyo_sys_getpid(), tomoyo_sys_getppid(),
171 current_uid(), current_gid(), current_euid(),
172 current_egid(), current_suid(), current_sgid(),
173 current_fsuid(), current_fsgid());
Tetsuo Handa8761afd2011-07-08 13:22:41 +0900174 if (!obj)
175 goto no_obj_info;
176 if (!obj->validate_done) {
177 tomoyo_get_attributes(obj);
178 obj->validate_done = true;
179 }
180 for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
181 struct tomoyo_mini_stat *stat;
182 unsigned int dev;
183 mode_t mode;
184 if (!obj->stat_valid[i])
185 continue;
186 stat = &obj->stat[i];
187 dev = stat->dev;
188 mode = stat->mode;
189 if (i & 1) {
190 pos += snprintf(buffer + pos,
191 tomoyo_buffer_len - 1 - pos,
192 " path%u.parent={ uid=%u gid=%u "
193 "ino=%lu perm=0%o }", (i >> 1) + 1,
194 stat->uid, stat->gid, (unsigned long)
195 stat->ino, stat->mode & S_IALLUGO);
196 continue;
197 }
198 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
199 " path%u={ uid=%u gid=%u ino=%lu major=%u"
200 " minor=%u perm=0%o type=%s", (i >> 1) + 1,
201 stat->uid, stat->gid, (unsigned long)
202 stat->ino, MAJOR(dev), MINOR(dev),
203 mode & S_IALLUGO, tomoyo_filetype(mode));
204 if (S_ISCHR(mode) || S_ISBLK(mode)) {
205 dev = stat->rdev;
206 pos += snprintf(buffer + pos,
207 tomoyo_buffer_len - 1 - pos,
208 " dev_major=%u dev_minor=%u",
209 MAJOR(dev), MINOR(dev));
210 }
211 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
212 " }");
213 }
214no_obj_info:
Tetsuo Handa2066a362011-07-08 13:21:37 +0900215 if (pos < tomoyo_buffer_len - 1)
216 return buffer;
217 kfree(buffer);
218 return NULL;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900219}
220
221/**
222 * tomoyo_init_log - Allocate buffer for audit logs.
223 *
224 * @r: Pointer to "struct tomoyo_request_info".
225 * @len: Buffer size needed for @fmt and @args.
226 * @fmt: The printf()'s format string.
227 * @args: va_list structure for @fmt.
228 *
229 * Returns pointer to allocated memory.
230 *
231 * This function uses kzalloc(), so caller must kfree() if this function
232 * didn't return NULL.
233 */
234char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
235 va_list args)
236{
237 char *buf = NULL;
Tetsuo Handa5b636852011-07-08 13:24:54 +0900238 char *bprm_info = NULL;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900239 const char *header = NULL;
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900240 char *realpath = NULL;
241 const char *symlink = NULL;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900242 int pos;
Tetsuo Handaea504812011-06-30 17:32:30 +0900243 const char *domainname = r->domain->domainname->name;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900244 header = tomoyo_print_header(r);
245 if (!header)
246 return NULL;
247 /* +10 is for '\n' etc. and '\0'. */
248 len += strlen(domainname) + strlen(header) + 10;
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900249 if (r->ee) {
250 struct file *file = r->ee->bprm->file;
251 realpath = tomoyo_realpath_from_path(&file->f_path);
Tetsuo Handa5b636852011-07-08 13:24:54 +0900252 bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
253 if (!realpath || !bprm_info)
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900254 goto out;
Tetsuo Handa5b636852011-07-08 13:24:54 +0900255 /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
256 len += strlen(realpath) + 80 + strlen(bprm_info);
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900257 } else if (r->obj && r->obj->symlink_target) {
258 symlink = r->obj->symlink_target->name;
259 /* +18 is for " symlink.target=\"%s\"" */
260 len += 18 + strlen(symlink);
261 }
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900262 len = tomoyo_round2(len);
263 buf = kzalloc(len, GFP_NOFS);
264 if (!buf)
265 goto out;
266 len--;
267 pos = snprintf(buf, len, "%s", header);
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900268 if (realpath) {
Tetsuo Handa5b636852011-07-08 13:24:54 +0900269 struct linux_binprm *bprm = r->ee->bprm;
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900270 pos += snprintf(buf + pos, len - pos,
Tetsuo Handa5b636852011-07-08 13:24:54 +0900271 " exec={ realpath=\"%s\" argc=%d envc=%d %s }",
272 realpath, bprm->argc, bprm->envc, bprm_info);
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900273 } else if (symlink)
274 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
275 symlink);
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900276 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
277 vsnprintf(buf + pos, len - pos, fmt, args);
278out:
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900279 kfree(realpath);
Tetsuo Handa5b636852011-07-08 13:24:54 +0900280 kfree(bprm_info);
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900281 kfree(header);
282 return buf;
283}
284
285/* Wait queue for /sys/kernel/security/tomoyo/audit. */
286static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
287
288/* Structure for audit log. */
289struct tomoyo_log {
290 struct list_head list;
291 char *log;
292 int size;
293};
294
295/* The list for "struct tomoyo_log". */
296static LIST_HEAD(tomoyo_log);
297
298/* Lock for "struct list_head tomoyo_log". */
299static DEFINE_SPINLOCK(tomoyo_log_lock);
300
301/* Length of "stuct list_head tomoyo_log". */
302static unsigned int tomoyo_log_count;
303
304/**
305 * tomoyo_get_audit - Get audit mode.
306 *
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900307 * @ns: Pointer to "struct tomoyo_policy_namespace".
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900308 * @profile: Profile number.
309 * @index: Index number of functionality.
310 * @is_granted: True if granted log, false otherwise.
311 *
312 * Returns true if this request should be audited, false otherwise.
313 */
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900314static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
315 const u8 profile, const u8 index,
Tetsuo Handa1f067a62011-09-10 15:24:56 +0900316 const struct tomoyo_acl_info *matched_acl,
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900317 const bool is_granted)
318{
319 u8 mode;
Tetsuo Handa2c47ab92011-06-26 23:21:19 +0900320 const u8 category = tomoyo_index2category[index] +
321 TOMOYO_MAX_MAC_INDEX;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900322 struct tomoyo_profile *p;
323 if (!tomoyo_policy_loaded)
324 return false;
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900325 p = tomoyo_profile(ns, profile);
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900326 if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
327 return false;
Tetsuo Handa1f067a62011-09-10 15:24:56 +0900328 if (is_granted && matched_acl && matched_acl->cond &&
329 matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO)
330 return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900331 mode = p->config[index];
332 if (mode == TOMOYO_CONFIG_USE_DEFAULT)
333 mode = p->config[category];
334 if (mode == TOMOYO_CONFIG_USE_DEFAULT)
335 mode = p->default_config;
336 if (is_granted)
337 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
338 return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
339}
340
341/**
342 * tomoyo_write_log2 - Write an audit log.
343 *
344 * @r: Pointer to "struct tomoyo_request_info".
345 * @len: Buffer size needed for @fmt and @args.
346 * @fmt: The printf()'s format string.
347 * @args: va_list structure for @fmt.
348 *
349 * Returns nothing.
350 */
351void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
352 va_list args)
353{
354 char *buf;
355 struct tomoyo_log *entry;
356 bool quota_exceeded = false;
Tetsuo Handa1f067a62011-09-10 15:24:56 +0900357 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type,
358 r->matched_acl, r->granted))
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900359 goto out;
360 buf = tomoyo_init_log(r, len, fmt, args);
361 if (!buf)
362 goto out;
363 entry = kzalloc(sizeof(*entry), GFP_NOFS);
364 if (!entry) {
365 kfree(buf);
366 goto out;
367 }
368 entry->log = buf;
369 len = tomoyo_round2(strlen(buf) + 1);
370 /*
371 * The entry->size is used for memory quota checks.
372 * Don't go beyond strlen(entry->log).
373 */
374 entry->size = len + tomoyo_round2(sizeof(*entry));
375 spin_lock(&tomoyo_log_lock);
376 if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
377 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
378 tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
379 quota_exceeded = true;
380 } else {
381 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
382 list_add_tail(&entry->list, &tomoyo_log);
383 tomoyo_log_count++;
384 }
385 spin_unlock(&tomoyo_log_lock);
386 if (quota_exceeded) {
387 kfree(buf);
388 kfree(entry);
389 goto out;
390 }
391 wake_up(&tomoyo_log_wait);
392out:
393 return;
394}
395
396/**
397 * tomoyo_write_log - Write an audit log.
398 *
399 * @r: Pointer to "struct tomoyo_request_info".
400 * @fmt: The printf()'s format string, followed by parameters.
401 *
402 * Returns nothing.
403 */
404void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
405{
406 va_list args;
407 int len;
408 va_start(args, fmt);
409 len = vsnprintf((char *) &len, 1, fmt, args) + 1;
410 va_end(args);
411 va_start(args, fmt);
412 tomoyo_write_log2(r, len, fmt, args);
413 va_end(args);
414}
415
416/**
417 * tomoyo_read_log - Read an audit log.
418 *
419 * @head: Pointer to "struct tomoyo_io_buffer".
420 *
421 * Returns nothing.
422 */
423void tomoyo_read_log(struct tomoyo_io_buffer *head)
424{
425 struct tomoyo_log *ptr = NULL;
426 if (head->r.w_pos)
427 return;
428 kfree(head->read_buf);
429 head->read_buf = NULL;
430 spin_lock(&tomoyo_log_lock);
431 if (!list_empty(&tomoyo_log)) {
432 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
433 list_del(&ptr->list);
434 tomoyo_log_count--;
435 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
436 }
437 spin_unlock(&tomoyo_log_lock);
438 if (ptr) {
439 head->read_buf = ptr->log;
440 head->r.w[head->r.w_pos++] = head->read_buf;
441 kfree(ptr);
442 }
443}
444
445/**
446 * tomoyo_poll_log - Wait for an audit log.
447 *
448 * @file: Pointer to "struct file".
449 * @wait: Pointer to "poll_table".
450 *
451 * Returns POLLIN | POLLRDNORM when ready to read an audit log.
452 */
453int tomoyo_poll_log(struct file *file, poll_table *wait)
454{
455 if (tomoyo_log_count)
456 return POLLIN | POLLRDNORM;
457 poll_wait(file, &tomoyo_log_wait, wait);
458 if (tomoyo_log_count)
459 return POLLIN | POLLRDNORM;
460 return 0;
461}