Commit | Line | Data |
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eadd99cc TH |
1 | /* |
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 | /** | |
13 | * tomoyo_convert_time - Convert time_t to YYYY/MM/DD hh/mm/ss. | |
14 | * | |
15 | * @time: Seconds since 1970/01/01 00:00:00. | |
16 | * @stamp: Pointer to "struct tomoyo_time". | |
17 | * | |
18 | * Returns nothing. | |
19 | * | |
20 | * This function does not handle Y2038 problem. | |
21 | */ | |
22 | static void tomoyo_convert_time(time_t time, struct tomoyo_time *stamp) | |
23 | { | |
24 | static const u16 tomoyo_eom[2][12] = { | |
25 | { 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, | |
26 | { 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } | |
27 | }; | |
28 | u16 y; | |
29 | u8 m; | |
30 | bool r; | |
31 | stamp->sec = time % 60; | |
32 | time /= 60; | |
33 | stamp->min = time % 60; | |
34 | time /= 60; | |
35 | stamp->hour = time % 24; | |
36 | time /= 24; | |
37 | for (y = 1970; ; y++) { | |
38 | const unsigned short days = (y & 3) ? 365 : 366; | |
39 | if (time < days) | |
40 | break; | |
41 | time -= days; | |
42 | } | |
43 | r = (y & 3) == 0; | |
44 | for (m = 0; m < 11 && time >= tomoyo_eom[r][m]; m++) | |
45 | ; | |
46 | if (m) | |
47 | time -= tomoyo_eom[r][m - 1]; | |
48 | stamp->year = y; | |
49 | stamp->month = ++m; | |
50 | stamp->day = ++time; | |
51 | } | |
52 | ||
53 | /** | |
54 | * tomoyo_print_header - Get header line of audit log. | |
55 | * | |
56 | * @r: Pointer to "struct tomoyo_request_info". | |
57 | * | |
58 | * Returns string representation. | |
59 | * | |
60 | * This function uses kmalloc(), so caller must kfree() if this function | |
61 | * didn't return NULL. | |
62 | */ | |
63 | static char *tomoyo_print_header(struct tomoyo_request_info *r) | |
64 | { | |
65 | struct tomoyo_time stamp; | |
66 | const pid_t gpid = task_pid_nr(current); | |
67 | static const int tomoyo_buffer_len = 4096; | |
68 | char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS); | |
69 | pid_t ppid; | |
70 | if (!buffer) | |
71 | return NULL; | |
72 | { | |
73 | struct timeval tv; | |
74 | do_gettimeofday(&tv); | |
75 | tomoyo_convert_time(tv.tv_sec, &stamp); | |
76 | } | |
77 | rcu_read_lock(); | |
78 | ppid = task_tgid_vnr(current->real_parent); | |
79 | rcu_read_unlock(); | |
80 | snprintf(buffer, tomoyo_buffer_len - 1, | |
81 | "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s " | |
82 | "granted=%s (global-pid=%u) task={ pid=%u ppid=%u " | |
83 | "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u " | |
84 | "fsuid=%u fsgid=%u }", | |
85 | stamp.year, stamp.month, stamp.day, stamp.hour, | |
86 | stamp.min, stamp.sec, r->profile, tomoyo_mode[r->mode], | |
87 | tomoyo_yesno(r->granted), gpid, task_tgid_vnr(current), ppid, | |
88 | current_uid(), current_gid(), current_euid(), current_egid(), | |
89 | current_suid(), current_sgid(), current_fsuid(), | |
90 | current_fsgid()); | |
91 | return buffer; | |
92 | } | |
93 | ||
94 | /** | |
95 | * tomoyo_init_log - Allocate buffer for audit logs. | |
96 | * | |
97 | * @r: Pointer to "struct tomoyo_request_info". | |
98 | * @len: Buffer size needed for @fmt and @args. | |
99 | * @fmt: The printf()'s format string. | |
100 | * @args: va_list structure for @fmt. | |
101 | * | |
102 | * Returns pointer to allocated memory. | |
103 | * | |
104 | * This function uses kzalloc(), so caller must kfree() if this function | |
105 | * didn't return NULL. | |
106 | */ | |
107 | char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt, | |
108 | va_list args) | |
109 | { | |
110 | char *buf = NULL; | |
111 | const char *header = NULL; | |
112 | int pos; | |
113 | const char *domainname = tomoyo_domain()->domainname->name; | |
114 | header = tomoyo_print_header(r); | |
115 | if (!header) | |
116 | return NULL; | |
117 | /* +10 is for '\n' etc. and '\0'. */ | |
118 | len += strlen(domainname) + strlen(header) + 10; | |
119 | len = tomoyo_round2(len); | |
120 | buf = kzalloc(len, GFP_NOFS); | |
121 | if (!buf) | |
122 | goto out; | |
123 | len--; | |
124 | pos = snprintf(buf, len, "%s", header); | |
125 | pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname); | |
126 | vsnprintf(buf + pos, len - pos, fmt, args); | |
127 | out: | |
128 | kfree(header); | |
129 | return buf; | |
130 | } | |
131 | ||
132 | /* Wait queue for /sys/kernel/security/tomoyo/audit. */ | |
133 | static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait); | |
134 | ||
135 | /* Structure for audit log. */ | |
136 | struct tomoyo_log { | |
137 | struct list_head list; | |
138 | char *log; | |
139 | int size; | |
140 | }; | |
141 | ||
142 | /* The list for "struct tomoyo_log". */ | |
143 | static LIST_HEAD(tomoyo_log); | |
144 | ||
145 | /* Lock for "struct list_head tomoyo_log". */ | |
146 | static DEFINE_SPINLOCK(tomoyo_log_lock); | |
147 | ||
148 | /* Length of "stuct list_head tomoyo_log". */ | |
149 | static unsigned int tomoyo_log_count; | |
150 | ||
151 | /** | |
152 | * tomoyo_get_audit - Get audit mode. | |
153 | * | |
bd03a3e4 | 154 | * @ns: Pointer to "struct tomoyo_policy_namespace". |
eadd99cc TH |
155 | * @profile: Profile number. |
156 | * @index: Index number of functionality. | |
157 | * @is_granted: True if granted log, false otherwise. | |
158 | * | |
159 | * Returns true if this request should be audited, false otherwise. | |
160 | */ | |
bd03a3e4 TH |
161 | static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, |
162 | const u8 profile, const u8 index, | |
eadd99cc TH |
163 | const bool is_granted) |
164 | { | |
165 | u8 mode; | |
166 | const u8 category = TOMOYO_MAC_CATEGORY_FILE + TOMOYO_MAX_MAC_INDEX; | |
167 | struct tomoyo_profile *p; | |
168 | if (!tomoyo_policy_loaded) | |
169 | return false; | |
bd03a3e4 | 170 | p = tomoyo_profile(ns, profile); |
eadd99cc TH |
171 | if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG]) |
172 | return false; | |
173 | mode = p->config[index]; | |
174 | if (mode == TOMOYO_CONFIG_USE_DEFAULT) | |
175 | mode = p->config[category]; | |
176 | if (mode == TOMOYO_CONFIG_USE_DEFAULT) | |
177 | mode = p->default_config; | |
178 | if (is_granted) | |
179 | return mode & TOMOYO_CONFIG_WANT_GRANT_LOG; | |
180 | return mode & TOMOYO_CONFIG_WANT_REJECT_LOG; | |
181 | } | |
182 | ||
183 | /** | |
184 | * tomoyo_write_log2 - Write an audit log. | |
185 | * | |
186 | * @r: Pointer to "struct tomoyo_request_info". | |
187 | * @len: Buffer size needed for @fmt and @args. | |
188 | * @fmt: The printf()'s format string. | |
189 | * @args: va_list structure for @fmt. | |
190 | * | |
191 | * Returns nothing. | |
192 | */ | |
193 | void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, | |
194 | va_list args) | |
195 | { | |
196 | char *buf; | |
197 | struct tomoyo_log *entry; | |
198 | bool quota_exceeded = false; | |
bd03a3e4 | 199 | if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, r->granted)) |
eadd99cc TH |
200 | goto out; |
201 | buf = tomoyo_init_log(r, len, fmt, args); | |
202 | if (!buf) | |
203 | goto out; | |
204 | entry = kzalloc(sizeof(*entry), GFP_NOFS); | |
205 | if (!entry) { | |
206 | kfree(buf); | |
207 | goto out; | |
208 | } | |
209 | entry->log = buf; | |
210 | len = tomoyo_round2(strlen(buf) + 1); | |
211 | /* | |
212 | * The entry->size is used for memory quota checks. | |
213 | * Don't go beyond strlen(entry->log). | |
214 | */ | |
215 | entry->size = len + tomoyo_round2(sizeof(*entry)); | |
216 | spin_lock(&tomoyo_log_lock); | |
217 | if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] && | |
218 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >= | |
219 | tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) { | |
220 | quota_exceeded = true; | |
221 | } else { | |
222 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size; | |
223 | list_add_tail(&entry->list, &tomoyo_log); | |
224 | tomoyo_log_count++; | |
225 | } | |
226 | spin_unlock(&tomoyo_log_lock); | |
227 | if (quota_exceeded) { | |
228 | kfree(buf); | |
229 | kfree(entry); | |
230 | goto out; | |
231 | } | |
232 | wake_up(&tomoyo_log_wait); | |
233 | out: | |
234 | return; | |
235 | } | |
236 | ||
237 | /** | |
238 | * tomoyo_write_log - Write an audit log. | |
239 | * | |
240 | * @r: Pointer to "struct tomoyo_request_info". | |
241 | * @fmt: The printf()'s format string, followed by parameters. | |
242 | * | |
243 | * Returns nothing. | |
244 | */ | |
245 | void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) | |
246 | { | |
247 | va_list args; | |
248 | int len; | |
249 | va_start(args, fmt); | |
250 | len = vsnprintf((char *) &len, 1, fmt, args) + 1; | |
251 | va_end(args); | |
252 | va_start(args, fmt); | |
253 | tomoyo_write_log2(r, len, fmt, args); | |
254 | va_end(args); | |
255 | } | |
256 | ||
257 | /** | |
258 | * tomoyo_read_log - Read an audit log. | |
259 | * | |
260 | * @head: Pointer to "struct tomoyo_io_buffer". | |
261 | * | |
262 | * Returns nothing. | |
263 | */ | |
264 | void tomoyo_read_log(struct tomoyo_io_buffer *head) | |
265 | { | |
266 | struct tomoyo_log *ptr = NULL; | |
267 | if (head->r.w_pos) | |
268 | return; | |
269 | kfree(head->read_buf); | |
270 | head->read_buf = NULL; | |
271 | spin_lock(&tomoyo_log_lock); | |
272 | if (!list_empty(&tomoyo_log)) { | |
273 | ptr = list_entry(tomoyo_log.next, typeof(*ptr), list); | |
274 | list_del(&ptr->list); | |
275 | tomoyo_log_count--; | |
276 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size; | |
277 | } | |
278 | spin_unlock(&tomoyo_log_lock); | |
279 | if (ptr) { | |
280 | head->read_buf = ptr->log; | |
281 | head->r.w[head->r.w_pos++] = head->read_buf; | |
282 | kfree(ptr); | |
283 | } | |
284 | } | |
285 | ||
286 | /** | |
287 | * tomoyo_poll_log - Wait for an audit log. | |
288 | * | |
289 | * @file: Pointer to "struct file". | |
290 | * @wait: Pointer to "poll_table". | |
291 | * | |
292 | * Returns POLLIN | POLLRDNORM when ready to read an audit log. | |
293 | */ | |
294 | int tomoyo_poll_log(struct file *file, poll_table *wait) | |
295 | { | |
296 | if (tomoyo_log_count) | |
297 | return POLLIN | POLLRDNORM; | |
298 | poll_wait(file, &tomoyo_log_wait, wait); | |
299 | if (tomoyo_log_count) | |
300 | return POLLIN | POLLRDNORM; | |
301 | return 0; | |
302 | } |