audit.c revision 2ca9bf453bdd478bcb6c01aa2d0bd4c2f4350563
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_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/** 42 * 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); 55 struct tomoyo_obj_info *obj = r->obj; 56 static const int tomoyo_buffer_len = 4096; 57 char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS); 58 int pos; 59 u8 i; 60 if (!buffer) 61 return NULL; 62 { 63 struct timeval tv; 64 do_gettimeofday(&tv); 65 tomoyo_convert_time(tv.tv_sec, &stamp); 66 } 67 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()); 78 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: 119 if (pos < tomoyo_buffer_len - 1) 120 return buffer; 121 kfree(buffer); 122 return NULL; 123} 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; 143 char *realpath = NULL; 144 const char *symlink = NULL; 145 int pos; 146 const char *domainname = r->domain->domainname->name; 147 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; 152 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 } 164 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); 170 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); 176 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname); 177 vsnprintf(buf + pos, len - pos, fmt, args); 178out: 179 kfree(realpath); 180 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 * 206 * @ns: Pointer to "struct tomoyo_policy_namespace". 207 * @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 */ 213static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, 214 const u8 profile, const u8 index, 215 const bool is_granted) 216{ 217 u8 mode; 218 const u8 category = tomoyo_index2category[index] + 219 TOMOYO_MAX_MAC_INDEX; 220 struct tomoyo_profile *p; 221 if (!tomoyo_policy_loaded) 222 return false; 223 p = tomoyo_profile(ns, profile); 224 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; 252 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, r->granted)) 253 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} 356