1 /* 2 * security/tomoyo/common.h 3 * 4 * Common functions for TOMOYO. 5 * 6 * Copyright (C) 2005-2009 NTT DATA CORPORATION 7 * 8 * Version: 2.2.0 2009/04/01 9 * 10 */ 11 12 #ifndef _SECURITY_TOMOYO_COMMON_H 13 #define _SECURITY_TOMOYO_COMMON_H 14 15 #include <linux/ctype.h> 16 #include <linux/string.h> 17 #include <linux/mm.h> 18 #include <linux/file.h> 19 #include <linux/kmod.h> 20 #include <linux/fs.h> 21 #include <linux/sched.h> 22 #include <linux/namei.h> 23 #include <linux/mount.h> 24 #include <linux/list.h> 25 26 struct dentry; 27 struct vfsmount; 28 29 /* 30 * tomoyo_page_buffer is a structure which is used for holding a pathname 31 * obtained from "struct dentry" and "struct vfsmount" pair. 32 * As of now, it is 4096 bytes. If users complain that 4096 bytes is too small 33 * (because TOMOYO escapes non ASCII printable characters using \ooo format), 34 * we will make the buffer larger. 35 */ 36 struct tomoyo_page_buffer { 37 char buffer[4096]; 38 }; 39 40 /* 41 * tomoyo_path_info is a structure which is used for holding a string data 42 * used by TOMOYO. 43 * This structure has several fields for supporting pattern matching. 44 * 45 * (1) "name" is the '\0' terminated string data. 46 * (2) "hash" is full_name_hash(name, strlen(name)). 47 * This allows tomoyo_pathcmp() to compare by hash before actually compare 48 * using strcmp(). 49 * (3) "const_len" is the length of the initial segment of "name" which 50 * consists entirely of non wildcard characters. In other words, the length 51 * which we can compare two strings using strncmp(). 52 * (4) "is_dir" is a bool which is true if "name" ends with "/", 53 * false otherwise. 54 * TOMOYO distinguishes directory and non-directory. A directory ends with 55 * "/" and non-directory does not end with "/". 56 * (5) "is_patterned" is a bool which is true if "name" contains wildcard 57 * characters, false otherwise. This allows TOMOYO to use "hash" and 58 * strcmp() for string comparison if "is_patterned" is false. 59 * (6) "depth" is calculated using the number of "/" characters in "name". 60 * This allows TOMOYO to avoid comparing two pathnames which never match 61 * (e.g. whether "/var/www/html/index.html" matches "/tmp/sh-thd-\$"). 62 */ 63 struct tomoyo_path_info { 64 const char *name; 65 u32 hash; /* = full_name_hash(name, strlen(name)) */ 66 u16 const_len; /* = tomoyo_const_part_length(name) */ 67 bool is_dir; /* = tomoyo_strendswith(name, "/") */ 68 bool is_patterned; /* = tomoyo_path_contains_pattern(name) */ 69 u16 depth; /* = tomoyo_path_depth(name) */ 70 }; 71 72 /* 73 * This is the max length of a token. 74 * 75 * A token consists of only ASCII printable characters. 76 * Non printable characters in a token is represented in \ooo style 77 * octal string. Thus, \ itself is represented as \\. 78 */ 79 #define TOMOYO_MAX_PATHNAME_LEN 4000 80 81 /* 82 * tomoyo_path_info_with_data is a structure which is used for holding a 83 * pathname obtained from "struct dentry" and "struct vfsmount" pair. 84 * 85 * "struct tomoyo_path_info_with_data" consists of "struct tomoyo_path_info" 86 * and buffer for the pathname, while "struct tomoyo_page_buffer" consists of 87 * buffer for the pathname only. 88 * 89 * "struct tomoyo_path_info_with_data" is intended to allow TOMOYO to release 90 * both "struct tomoyo_path_info" and buffer for the pathname by single kfree() 91 * so that we don't need to return two pointers to the caller. If the caller 92 * puts "struct tomoyo_path_info" on stack memory, we will be able to remove 93 * "struct tomoyo_path_info_with_data". 94 */ 95 struct tomoyo_path_info_with_data { 96 /* Keep "head" first, for this pointer is passed to tomoyo_free(). */ 97 struct tomoyo_path_info head; 98 char barrier1[16]; /* Safeguard for overrun. */ 99 char body[TOMOYO_MAX_PATHNAME_LEN]; 100 char barrier2[16]; /* Safeguard for overrun. */ 101 }; 102 103 /* 104 * tomoyo_acl_info is a structure which is used for holding 105 * 106 * (1) "list" which is linked to the ->acl_info_list of 107 * "struct tomoyo_domain_info" 108 * (2) "type" which tells 109 * (a) type & 0x7F : type of the entry (either 110 * "struct tomoyo_single_path_acl_record" or 111 * "struct tomoyo_double_path_acl_record") 112 * (b) type & 0x80 : whether the entry is marked as "deleted". 113 * 114 * Packing "struct tomoyo_acl_info" allows 115 * "struct tomoyo_single_path_acl_record" to embed "u16" and 116 * "struct tomoyo_double_path_acl_record" to embed "u8" 117 * without enlarging their structure size. 118 */ 119 struct tomoyo_acl_info { 120 struct list_head list; 121 /* 122 * Type of this ACL entry. 123 * 124 * MSB is is_deleted flag. 125 */ 126 u8 type; 127 } __packed; 128 129 /* This ACL entry is deleted. */ 130 #define TOMOYO_ACL_DELETED 0x80 131 132 /* 133 * tomoyo_domain_info is a structure which is used for holding permissions 134 * (e.g. "allow_read /lib/libc-2.5.so") given to each domain. 135 * It has following fields. 136 * 137 * (1) "list" which is linked to tomoyo_domain_list . 138 * (2) "acl_info_list" which is linked to "struct tomoyo_acl_info". 139 * (3) "domainname" which holds the name of the domain. 140 * (4) "profile" which remembers profile number assigned to this domain. 141 * (5) "is_deleted" is a bool which is true if this domain is marked as 142 * "deleted", false otherwise. 143 * (6) "quota_warned" is a bool which is used for suppressing warning message 144 * when learning mode learned too much entries. 145 * (7) "flags" which remembers this domain's attributes. 146 * 147 * A domain's lifecycle is an analogy of files on / directory. 148 * Multiple domains with the same domainname cannot be created (as with 149 * creating files with the same filename fails with -EEXIST). 150 * If a process reached a domain, that process can reside in that domain after 151 * that domain is marked as "deleted" (as with a process can access an already 152 * open()ed file after that file was unlink()ed). 153 */ 154 struct tomoyo_domain_info { 155 struct list_head list; 156 struct list_head acl_info_list; 157 /* Name of this domain. Never NULL. */ 158 const struct tomoyo_path_info *domainname; 159 u8 profile; /* Profile number to use. */ 160 bool is_deleted; /* Delete flag. */ 161 bool quota_warned; /* Quota warnning flag. */ 162 /* DOMAIN_FLAGS_*. Use tomoyo_set_domain_flag() to modify. */ 163 u8 flags; 164 }; 165 166 /* Profile number is an integer between 0 and 255. */ 167 #define TOMOYO_MAX_PROFILES 256 168 169 /* Ignore "allow_read" directive in exception policy. */ 170 #define TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ 1 171 /* 172 * This domain was unable to create a new domain at tomoyo_find_next_domain() 173 * because the name of the domain to be created was too long or 174 * it could not allocate memory. 175 * More than one process continued execve() without domain transition. 176 */ 177 #define TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED 2 178 179 /* 180 * tomoyo_single_path_acl_record is a structure which is used for holding an 181 * entry with one pathname operation (e.g. open(), mkdir()). 182 * It has following fields. 183 * 184 * (1) "head" which is a "struct tomoyo_acl_info". 185 * (2) "perm" which is a bitmask of permitted operations. 186 * (3) "filename" is the pathname. 187 * 188 * Directives held by this structure are "allow_read/write", "allow_execute", 189 * "allow_read", "allow_write", "allow_create", "allow_unlink", "allow_mkdir", 190 * "allow_rmdir", "allow_mkfifo", "allow_mksock", "allow_mkblock", 191 * "allow_mkchar", "allow_truncate", "allow_symlink" and "allow_rewrite". 192 */ 193 struct tomoyo_single_path_acl_record { 194 struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_SINGLE_PATH_ACL */ 195 u16 perm; 196 /* Pointer to single pathname. */ 197 const struct tomoyo_path_info *filename; 198 }; 199 200 /* 201 * tomoyo_double_path_acl_record is a structure which is used for holding an 202 * entry with two pathnames operation (i.e. link() and rename()). 203 * It has following fields. 204 * 205 * (1) "head" which is a "struct tomoyo_acl_info". 206 * (2) "perm" which is a bitmask of permitted operations. 207 * (3) "filename1" is the source/old pathname. 208 * (4) "filename2" is the destination/new pathname. 209 * 210 * Directives held by this structure are "allow_rename" and "allow_link". 211 */ 212 struct tomoyo_double_path_acl_record { 213 struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_DOUBLE_PATH_ACL */ 214 u8 perm; 215 /* Pointer to single pathname. */ 216 const struct tomoyo_path_info *filename1; 217 /* Pointer to single pathname. */ 218 const struct tomoyo_path_info *filename2; 219 }; 220 221 /* Keywords for ACLs. */ 222 #define TOMOYO_KEYWORD_ALIAS "alias " 223 #define TOMOYO_KEYWORD_ALLOW_READ "allow_read " 224 #define TOMOYO_KEYWORD_DELETE "delete " 225 #define TOMOYO_KEYWORD_DENY_REWRITE "deny_rewrite " 226 #define TOMOYO_KEYWORD_FILE_PATTERN "file_pattern " 227 #define TOMOYO_KEYWORD_INITIALIZE_DOMAIN "initialize_domain " 228 #define TOMOYO_KEYWORD_KEEP_DOMAIN "keep_domain " 229 #define TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN "no_initialize_domain " 230 #define TOMOYO_KEYWORD_NO_KEEP_DOMAIN "no_keep_domain " 231 #define TOMOYO_KEYWORD_SELECT "select " 232 #define TOMOYO_KEYWORD_USE_PROFILE "use_profile " 233 #define TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ "ignore_global_allow_read" 234 /* A domain definition starts with <kernel>. */ 235 #define TOMOYO_ROOT_NAME "<kernel>" 236 #define TOMOYO_ROOT_NAME_LEN (sizeof(TOMOYO_ROOT_NAME) - 1) 237 238 /* Index numbers for Access Controls. */ 239 #define TOMOYO_MAC_FOR_FILE 0 /* domain_policy.conf */ 240 #define TOMOYO_MAX_ACCEPT_ENTRY 1 241 #define TOMOYO_VERBOSE 2 242 #define TOMOYO_MAX_CONTROL_INDEX 3 243 244 /* 245 * tomoyo_io_buffer is a structure which is used for reading and modifying 246 * configuration via /sys/kernel/security/tomoyo/ interface. 247 * It has many fields. ->read_var1 , ->read_var2 , ->write_var1 are used as 248 * cursors. 249 * 250 * Since the content of /sys/kernel/security/tomoyo/domain_policy is a list of 251 * "struct tomoyo_domain_info" entries and each "struct tomoyo_domain_info" 252 * entry has a list of "struct tomoyo_acl_info", we need two cursors when 253 * reading (one is for traversing tomoyo_domain_list and the other is for 254 * traversing "struct tomoyo_acl_info"->acl_info_list ). 255 * 256 * If a line written to /sys/kernel/security/tomoyo/domain_policy starts with 257 * "select ", TOMOYO seeks the cursor ->read_var1 and ->write_var1 to the 258 * domain with the domainname specified by the rest of that line (NULL is set 259 * if seek failed). 260 * If a line written to /sys/kernel/security/tomoyo/domain_policy starts with 261 * "delete ", TOMOYO deletes an entry or a domain specified by the rest of that 262 * line (->write_var1 is set to NULL if a domain was deleted). 263 * If a line written to /sys/kernel/security/tomoyo/domain_policy starts with 264 * neither "select " nor "delete ", an entry or a domain specified by that line 265 * is appended. 266 */ 267 struct tomoyo_io_buffer { 268 int (*read) (struct tomoyo_io_buffer *); 269 int (*write) (struct tomoyo_io_buffer *); 270 /* Exclusive lock for this structure. */ 271 struct mutex io_sem; 272 /* The position currently reading from. */ 273 struct list_head *read_var1; 274 /* Extra variables for reading. */ 275 struct list_head *read_var2; 276 /* The position currently writing to. */ 277 struct tomoyo_domain_info *write_var1; 278 /* The step for reading. */ 279 int read_step; 280 /* Buffer for reading. */ 281 char *read_buf; 282 /* EOF flag for reading. */ 283 bool read_eof; 284 /* Read domain ACL of specified PID? */ 285 bool read_single_domain; 286 /* Extra variable for reading. */ 287 u8 read_bit; 288 /* Bytes available for reading. */ 289 int read_avail; 290 /* Size of read buffer. */ 291 int readbuf_size; 292 /* Buffer for writing. */ 293 char *write_buf; 294 /* Bytes available for writing. */ 295 int write_avail; 296 /* Size of write buffer. */ 297 int writebuf_size; 298 }; 299 300 /* Check whether the domain has too many ACL entries to hold. */ 301 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain); 302 /* Transactional sprintf() for policy dump. */ 303 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...) 304 __attribute__ ((format(printf, 2, 3))); 305 /* Check whether the domainname is correct. */ 306 bool tomoyo_is_correct_domain(const unsigned char *domainname, 307 const char *function); 308 /* Check whether the token is correct. */ 309 bool tomoyo_is_correct_path(const char *filename, const s8 start_type, 310 const s8 pattern_type, const s8 end_type, 311 const char *function); 312 /* Check whether the token can be a domainname. */ 313 bool tomoyo_is_domain_def(const unsigned char *buffer); 314 /* Check whether the given filename matches the given pattern. */ 315 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename, 316 const struct tomoyo_path_info *pattern); 317 /* Read "alias" entry in exception policy. */ 318 bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head); 319 /* 320 * Read "initialize_domain" and "no_initialize_domain" entry 321 * in exception policy. 322 */ 323 bool tomoyo_read_domain_initializer_policy(struct tomoyo_io_buffer *head); 324 /* Read "keep_domain" and "no_keep_domain" entry in exception policy. */ 325 bool tomoyo_read_domain_keeper_policy(struct tomoyo_io_buffer *head); 326 /* Read "file_pattern" entry in exception policy. */ 327 bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head); 328 /* Read "allow_read" entry in exception policy. */ 329 bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head); 330 /* Read "deny_rewrite" entry in exception policy. */ 331 bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head); 332 /* Write domain policy violation warning message to console? */ 333 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain); 334 /* Convert double path operation to operation name. */ 335 const char *tomoyo_dp2keyword(const u8 operation); 336 /* Get the last component of the given domainname. */ 337 const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain); 338 /* Get warning message. */ 339 const char *tomoyo_get_msg(const bool is_enforce); 340 /* Convert single path operation to operation name. */ 341 const char *tomoyo_sp2keyword(const u8 operation); 342 /* Delete a domain. */ 343 int tomoyo_delete_domain(char *data); 344 /* Create "alias" entry in exception policy. */ 345 int tomoyo_write_alias_policy(char *data, const bool is_delete); 346 /* 347 * Create "initialize_domain" and "no_initialize_domain" entry 348 * in exception policy. 349 */ 350 int tomoyo_write_domain_initializer_policy(char *data, const bool is_not, 351 const bool is_delete); 352 /* Create "keep_domain" and "no_keep_domain" entry in exception policy. */ 353 int tomoyo_write_domain_keeper_policy(char *data, const bool is_not, 354 const bool is_delete); 355 /* 356 * Create "allow_read/write", "allow_execute", "allow_read", "allow_write", 357 * "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir", 358 * "allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar", 359 * "allow_truncate", "allow_symlink", "allow_rewrite", "allow_rename" and 360 * "allow_link" entry in domain policy. 361 */ 362 int tomoyo_write_file_policy(char *data, struct tomoyo_domain_info *domain, 363 const bool is_delete); 364 /* Create "allow_read" entry in exception policy. */ 365 int tomoyo_write_globally_readable_policy(char *data, const bool is_delete); 366 /* Create "deny_rewrite" entry in exception policy. */ 367 int tomoyo_write_no_rewrite_policy(char *data, const bool is_delete); 368 /* Create "file_pattern" entry in exception policy. */ 369 int tomoyo_write_pattern_policy(char *data, const bool is_delete); 370 /* Find a domain by the given name. */ 371 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname); 372 /* Find or create a domain by the given name. */ 373 struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char * 374 domainname, 375 const u8 profile); 376 /* Check mode for specified functionality. */ 377 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain, 378 const u8 index); 379 /* Allocate memory for structures. */ 380 void *tomoyo_alloc_acl_element(const u8 acl_type); 381 /* Fill in "struct tomoyo_path_info" members. */ 382 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr); 383 /* Run policy loader when /sbin/init starts. */ 384 void tomoyo_load_policy(const char *filename); 385 /* Change "struct tomoyo_domain_info"->flags. */ 386 void tomoyo_set_domain_flag(struct tomoyo_domain_info *domain, 387 const bool is_delete, const u8 flags); 388 389 /* strcmp() for "struct tomoyo_path_info" structure. */ 390 static inline bool tomoyo_pathcmp(const struct tomoyo_path_info *a, 391 const struct tomoyo_path_info *b) 392 { 393 return a->hash != b->hash || strcmp(a->name, b->name); 394 } 395 396 /* Get type of an ACL entry. */ 397 static inline u8 tomoyo_acl_type1(struct tomoyo_acl_info *ptr) 398 { 399 return ptr->type & ~TOMOYO_ACL_DELETED; 400 } 401 402 /* Get type of an ACL entry. */ 403 static inline u8 tomoyo_acl_type2(struct tomoyo_acl_info *ptr) 404 { 405 return ptr->type; 406 } 407 408 /** 409 * tomoyo_is_valid - Check whether the character is a valid char. 410 * 411 * @c: The character to check. 412 * 413 * Returns true if @c is a valid character, false otherwise. 414 */ 415 static inline bool tomoyo_is_valid(const unsigned char c) 416 { 417 return c > ' ' && c < 127; 418 } 419 420 /** 421 * tomoyo_is_invalid - Check whether the character is an invalid char. 422 * 423 * @c: The character to check. 424 * 425 * Returns true if @c is an invalid character, false otherwise. 426 */ 427 static inline bool tomoyo_is_invalid(const unsigned char c) 428 { 429 return c && (c <= ' ' || c >= 127); 430 } 431 432 /* The list for "struct tomoyo_domain_info". */ 433 extern struct list_head tomoyo_domain_list; 434 extern struct rw_semaphore tomoyo_domain_list_lock; 435 436 /* Lock for domain->acl_info_list. */ 437 extern struct rw_semaphore tomoyo_domain_acl_info_list_lock; 438 439 /* Has /sbin/init started? */ 440 extern bool tomoyo_policy_loaded; 441 442 /* The kernel's domain. */ 443 extern struct tomoyo_domain_info tomoyo_kernel_domain; 444 445 /** 446 * list_for_each_cookie - iterate over a list with cookie. 447 * @pos: the &struct list_head to use as a loop cursor. 448 * @cookie: the &struct list_head to use as a cookie. 449 * @head: the head for your list. 450 * 451 * Same with list_for_each() except that this primitive uses @cookie 452 * so that we can continue iteration. 453 * @cookie must be NULL when iteration starts, and @cookie will become 454 * NULL when iteration finishes. 455 */ 456 #define list_for_each_cookie(pos, cookie, head) \ 457 for (({ if (!cookie) \ 458 cookie = head; }), \ 459 pos = (cookie)->next; \ 460 prefetch(pos->next), pos != (head) || ((cookie) = NULL); \ 461 (cookie) = pos, pos = pos->next) 462 463 #endif /* !defined(_SECURITY_TOMOYO_COMMON_H) */ 464