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Tetsuo Handaeadd99c2011-06-26 23:18:58 +09001/*
2 * security/tomoyo/audit.c
3 *
4 * Pathname restriction functions.
5 *
6 * Copyright (C) 2005-2010 NTT DATA CORPORATION
7 */
8
9#include "common.h"
10#include <linux/slab.h>
11
12/**
Tetsuo Handa8761afd2011-07-08 13:22:41 +090013 * tomoyo_filetype - Get string representation of file type.
14 *
15 * @mode: Mode value for stat().
16 *
17 * Returns file type string.
18 */
19static inline const char *tomoyo_filetype(const mode_t mode)
20{
21 switch (mode & S_IFMT) {
22 case S_IFREG:
23 case 0:
24 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE];
25 case S_IFDIR:
26 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY];
27 case S_IFLNK:
28 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK];
29 case S_IFIFO:
30 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO];
31 case S_IFSOCK:
32 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET];
33 case S_IFBLK:
34 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV];
35 case S_IFCHR:
36 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV];
37 }
38 return "unknown"; /* This should not happen. */
39}
40
41/**
Tetsuo Handaeadd99c2011-06-26 23:18:58 +090042 * tomoyo_print_header - Get header line of audit log.
43 *
44 * @r: Pointer to "struct tomoyo_request_info".
45 *
46 * Returns string representation.
47 *
48 * This function uses kmalloc(), so caller must kfree() if this function
49 * didn't return NULL.
50 */
51static char *tomoyo_print_header(struct tomoyo_request_info *r)
52{
53 struct tomoyo_time stamp;
54 const pid_t gpid = task_pid_nr(current);
Tetsuo Handa8761afd2011-07-08 13:22:41 +090055 struct tomoyo_obj_info *obj = r->obj;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +090056 static const int tomoyo_buffer_len = 4096;
57 char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
Tetsuo Handa2066a362011-07-08 13:21:37 +090058 int pos;
Tetsuo Handa8761afd2011-07-08 13:22:41 +090059 u8 i;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +090060 if (!buffer)
61 return NULL;
62 {
63 struct timeval tv;
64 do_gettimeofday(&tv);
65 tomoyo_convert_time(tv.tv_sec, &stamp);
66 }
Tetsuo Handa2066a362011-07-08 13:21:37 +090067 pos = snprintf(buffer, tomoyo_buffer_len - 1,
68 "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
69 "granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
70 "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
71 "fsuid=%u fsgid=%u }", stamp.year, stamp.month,
72 stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile,
73 tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid,
74 tomoyo_sys_getpid(), tomoyo_sys_getppid(),
75 current_uid(), current_gid(), current_euid(),
76 current_egid(), current_suid(), current_sgid(),
77 current_fsuid(), current_fsgid());
Tetsuo Handa8761afd2011-07-08 13:22:41 +090078 if (!obj)
79 goto no_obj_info;
80 if (!obj->validate_done) {
81 tomoyo_get_attributes(obj);
82 obj->validate_done = true;
83 }
84 for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) {
85 struct tomoyo_mini_stat *stat;
86 unsigned int dev;
87 mode_t mode;
88 if (!obj->stat_valid[i])
89 continue;
90 stat = &obj->stat[i];
91 dev = stat->dev;
92 mode = stat->mode;
93 if (i & 1) {
94 pos += snprintf(buffer + pos,
95 tomoyo_buffer_len - 1 - pos,
96 " path%u.parent={ uid=%u gid=%u "
97 "ino=%lu perm=0%o }", (i >> 1) + 1,
98 stat->uid, stat->gid, (unsigned long)
99 stat->ino, stat->mode & S_IALLUGO);
100 continue;
101 }
102 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
103 " path%u={ uid=%u gid=%u ino=%lu major=%u"
104 " minor=%u perm=0%o type=%s", (i >> 1) + 1,
105 stat->uid, stat->gid, (unsigned long)
106 stat->ino, MAJOR(dev), MINOR(dev),
107 mode & S_IALLUGO, tomoyo_filetype(mode));
108 if (S_ISCHR(mode) || S_ISBLK(mode)) {
109 dev = stat->rdev;
110 pos += snprintf(buffer + pos,
111 tomoyo_buffer_len - 1 - pos,
112 " dev_major=%u dev_minor=%u",
113 MAJOR(dev), MINOR(dev));
114 }
115 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
116 " }");
117 }
118no_obj_info:
Tetsuo Handa2066a362011-07-08 13:21:37 +0900119 if (pos < tomoyo_buffer_len - 1)
120 return buffer;
121 kfree(buffer);
122 return NULL;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900123}
124
125/**
126 * tomoyo_init_log - Allocate buffer for audit logs.
127 *
128 * @r: Pointer to "struct tomoyo_request_info".
129 * @len: Buffer size needed for @fmt and @args.
130 * @fmt: The printf()'s format string.
131 * @args: va_list structure for @fmt.
132 *
133 * Returns pointer to allocated memory.
134 *
135 * This function uses kzalloc(), so caller must kfree() if this function
136 * didn't return NULL.
137 */
138char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
139 va_list args)
140{
141 char *buf = NULL;
142 const char *header = NULL;
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900143 char *realpath = NULL;
144 const char *symlink = NULL;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900145 int pos;
Tetsuo Handaea504812011-06-30 17:32:30 +0900146 const char *domainname = r->domain->domainname->name;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900147 header = tomoyo_print_header(r);
148 if (!header)
149 return NULL;
150 /* +10 is for '\n' etc. and '\0'. */
151 len += strlen(domainname) + strlen(header) + 10;
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900152 if (r->ee) {
153 struct file *file = r->ee->bprm->file;
154 realpath = tomoyo_realpath_from_path(&file->f_path);
155 if (!realpath)
156 goto out;
157 /* +80 is for " exec={ realpath=\"%s\" }" */
158 len += strlen(realpath) + 80;
159 } else if (r->obj && r->obj->symlink_target) {
160 symlink = r->obj->symlink_target->name;
161 /* +18 is for " symlink.target=\"%s\"" */
162 len += 18 + strlen(symlink);
163 }
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900164 len = tomoyo_round2(len);
165 buf = kzalloc(len, GFP_NOFS);
166 if (!buf)
167 goto out;
168 len--;
169 pos = snprintf(buf, len, "%s", header);
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900170 if (realpath) {
171 pos += snprintf(buf + pos, len - pos,
172 " exec={ realpath=\"%s\" }", realpath);
173 } else if (symlink)
174 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
175 symlink);
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900176 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
177 vsnprintf(buf + pos, len - pos, fmt, args);
178out:
Tetsuo Handa2ca9bf42011-07-08 13:23:44 +0900179 kfree(realpath);
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900180 kfree(header);
181 return buf;
182}
183
184/* Wait queue for /sys/kernel/security/tomoyo/audit. */
185static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
186
187/* Structure for audit log. */
188struct tomoyo_log {
189 struct list_head list;
190 char *log;
191 int size;
192};
193
194/* The list for "struct tomoyo_log". */
195static LIST_HEAD(tomoyo_log);
196
197/* Lock for "struct list_head tomoyo_log". */
198static DEFINE_SPINLOCK(tomoyo_log_lock);
199
200/* Length of "stuct list_head tomoyo_log". */
201static unsigned int tomoyo_log_count;
202
203/**
204 * tomoyo_get_audit - Get audit mode.
205 *
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900206 * @ns: Pointer to "struct tomoyo_policy_namespace".
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900207 * @profile: Profile number.
208 * @index: Index number of functionality.
209 * @is_granted: True if granted log, false otherwise.
210 *
211 * Returns true if this request should be audited, false otherwise.
212 */
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900213static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
214 const u8 profile, const u8 index,
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900215 const bool is_granted)
216{
217 u8 mode;
Tetsuo Handa2c47ab92011-06-26 23:21:19 +0900218 const u8 category = tomoyo_index2category[index] +
219 TOMOYO_MAX_MAC_INDEX;
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900220 struct tomoyo_profile *p;
221 if (!tomoyo_policy_loaded)
222 return false;
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900223 p = tomoyo_profile(ns, profile);
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900224 if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
225 return false;
226 mode = p->config[index];
227 if (mode == TOMOYO_CONFIG_USE_DEFAULT)
228 mode = p->config[category];
229 if (mode == TOMOYO_CONFIG_USE_DEFAULT)
230 mode = p->default_config;
231 if (is_granted)
232 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
233 return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
234}
235
236/**
237 * tomoyo_write_log2 - Write an audit log.
238 *
239 * @r: Pointer to "struct tomoyo_request_info".
240 * @len: Buffer size needed for @fmt and @args.
241 * @fmt: The printf()'s format string.
242 * @args: va_list structure for @fmt.
243 *
244 * Returns nothing.
245 */
246void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
247 va_list args)
248{
249 char *buf;
250 struct tomoyo_log *entry;
251 bool quota_exceeded = false;
Tetsuo Handabd03a3e2011-06-26 23:19:52 +0900252 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, r->granted))
Tetsuo Handaeadd99c2011-06-26 23:18:58 +0900253 goto out;
254 buf = tomoyo_init_log(r, len, fmt, args);
255 if (!buf)
256 goto out;
257 entry = kzalloc(sizeof(*entry), GFP_NOFS);
258 if (!entry) {
259 kfree(buf);
260 goto out;
261 }
262 entry->log = buf;
263 len = tomoyo_round2(strlen(buf) + 1);
264 /*
265 * The entry->size is used for memory quota checks.
266 * Don't go beyond strlen(entry->log).
267 */
268 entry->size = len + tomoyo_round2(sizeof(*entry));
269 spin_lock(&tomoyo_log_lock);
270 if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
271 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
272 tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
273 quota_exceeded = true;
274 } else {
275 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
276 list_add_tail(&entry->list, &tomoyo_log);
277 tomoyo_log_count++;
278 }
279 spin_unlock(&tomoyo_log_lock);
280 if (quota_exceeded) {
281 kfree(buf);
282 kfree(entry);
283 goto out;
284 }
285 wake_up(&tomoyo_log_wait);
286out:
287 return;
288}
289
290/**
291 * tomoyo_write_log - Write an audit log.
292 *
293 * @r: Pointer to "struct tomoyo_request_info".
294 * @fmt: The printf()'s format string, followed by parameters.
295 *
296 * Returns nothing.
297 */
298void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
299{
300 va_list args;
301 int len;
302 va_start(args, fmt);
303 len = vsnprintf((char *) &len, 1, fmt, args) + 1;
304 va_end(args);
305 va_start(args, fmt);
306 tomoyo_write_log2(r, len, fmt, args);
307 va_end(args);
308}
309
310/**
311 * tomoyo_read_log - Read an audit log.
312 *
313 * @head: Pointer to "struct tomoyo_io_buffer".
314 *
315 * Returns nothing.
316 */
317void tomoyo_read_log(struct tomoyo_io_buffer *head)
318{
319 struct tomoyo_log *ptr = NULL;
320 if (head->r.w_pos)
321 return;
322 kfree(head->read_buf);
323 head->read_buf = NULL;
324 spin_lock(&tomoyo_log_lock);
325 if (!list_empty(&tomoyo_log)) {
326 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
327 list_del(&ptr->list);
328 tomoyo_log_count--;
329 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
330 }
331 spin_unlock(&tomoyo_log_lock);
332 if (ptr) {
333 head->read_buf = ptr->log;
334 head->r.w[head->r.w_pos++] = head->read_buf;
335 kfree(ptr);
336 }
337}
338
339/**
340 * tomoyo_poll_log - Wait for an audit log.
341 *
342 * @file: Pointer to "struct file".
343 * @wait: Pointer to "poll_table".
344 *
345 * Returns POLLIN | POLLRDNORM when ready to read an audit log.
346 */
347int tomoyo_poll_log(struct file *file, poll_table *wait)
348{
349 if (tomoyo_log_count)
350 return POLLIN | POLLRDNORM;
351 poll_wait(file, &tomoyo_log_wait, wait);
352 if (tomoyo_log_count)
353 return POLLIN | POLLRDNORM;
354 return 0;
355}