security/tomoyo/common.h

   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 /* Temporary buffer for holding pathnames. */
  30 struct tomoyo_page_buffer {
  31         char buffer[4096];
  32 };
  33
  34 /* Structure for holding a token. */
  35 struct tomoyo_path_info {
  36         const char *name;
  37         u32 hash;          /* = full_name_hash(name, strlen(name)) */
  38         u16 total_len;     /* = strlen(name)                       */
  39         u16 const_len;     /* = tomoyo_const_part_length(name)     */
  40         bool is_dir;       /* = tomoyo_strendswith(name, "/")      */
  41         bool is_patterned; /* = tomoyo_path_contains_pattern(name) */
  42         u16 depth;         /* = tomoyo_path_depth(name)            */
  43 };
  44
  45 /*
  46  * This is the max length of a token.
  47  *
  48  * A token consists of only ASCII printable characters.
  49  * Non printable characters in a token is represented in \ooo style
  50  * octal string. Thus, \ itself is represented as \\.
  51  */
  52 #define TOMOYO_MAX_PATHNAME_LEN 4000
  53
  54 /* Structure for holding requested pathname. */
  55 struct tomoyo_path_info_with_data {
  56         /* Keep "head" first, for this pointer is passed to tomoyo_free(). */
  57         struct tomoyo_path_info head;
  58         char barrier1[16]; /* Safeguard for overrun. */
  59         char body[TOMOYO_MAX_PATHNAME_LEN];
  60         char barrier2[16]; /* Safeguard for overrun. */
  61 };
  62
  63 /*
  64  * Common header for holding ACL entries.
  65  *
  66  * Packing "struct tomoyo_acl_info" allows
  67  * "struct tomoyo_single_path_acl_record" to embed "u16" and
  68  * "struct tomoyo_double_path_acl_record" to embed "u8"
  69  * without enlarging their structure size.
  70  */
  71 struct tomoyo_acl_info {
  72         struct list_head list;
  73         /*
  74          * Type of this ACL entry.
  75          *
  76          * MSB is is_deleted flag.
  77          */
  78         u8 type;
  79 } __packed;
  80
  81 /* This ACL entry is deleted.           */
  82 #define TOMOYO_ACL_DELETED        0x80
  83
  84 /* Structure for domain information. */
  85 struct tomoyo_domain_info {
  86         struct list_head list;
  87         struct list_head acl_info_list;
  88         /* Name of this domain. Never NULL.          */
  89         const struct tomoyo_path_info *domainname;
  90         u8 profile;        /* Profile number to use. */
  91         bool is_deleted;   /* Delete flag.           */
  92         bool quota_warned; /* Quota warnning flag.   */
  93         /* DOMAIN_FLAGS_*. Use tomoyo_set_domain_flag() to modify. */
  94         u8 flags;
  95 };
  96
  97 /* Profile number is an integer between 0 and 255. */
  98 #define TOMOYO_MAX_PROFILES 256
  99
 100 /* Ignore "allow_read" directive in exception policy. */
 101 #define TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ 1
 102 /*
 103  * This domain was unable to create a new domain at tomoyo_find_next_domain()
 104  * because the name of the domain to be created was too long or
 105  * it could not allocate memory.
 106  * More than one process continued execve() without domain transition.
 107  */
 108 #define TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED        2
 109
 110 /*
 111  * Structure for "allow_read/write", "allow_execute", "allow_read",
 112  * "allow_write", "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir",
 113  * "allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar",
 114  * "allow_truncate", "allow_symlink" and "allow_rewrite" directive.
 115  */
 116 struct tomoyo_single_path_acl_record {
 117         struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_SINGLE_PATH_ACL */
 118         u16 perm;
 119         /* Pointer to single pathname. */
 120         const struct tomoyo_path_info *filename;
 121 };
 122
 123 /* Structure for "allow_rename" and "allow_link" directive. */
 124 struct tomoyo_double_path_acl_record {
 125         struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_DOUBLE_PATH_ACL */
 126         u8 perm;
 127         /* Pointer to single pathname. */
 128         const struct tomoyo_path_info *filename1;
 129         /* Pointer to single pathname. */
 130         const struct tomoyo_path_info *filename2;
 131 };
 132
 133 /* Keywords for ACLs. */
 134 #define TOMOYO_KEYWORD_ALIAS                     "alias "
 135 #define TOMOYO_KEYWORD_ALLOW_READ                "allow_read "
 136 #define TOMOYO_KEYWORD_DELETE                    "delete "
 137 #define TOMOYO_KEYWORD_DENY_REWRITE              "deny_rewrite "
 138 #define TOMOYO_KEYWORD_FILE_PATTERN              "file_pattern "
 139 #define TOMOYO_KEYWORD_INITIALIZE_DOMAIN         "initialize_domain "
 140 #define TOMOYO_KEYWORD_KEEP_DOMAIN               "keep_domain "
 141 #define TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN      "no_initialize_domain "
 142 #define TOMOYO_KEYWORD_NO_KEEP_DOMAIN            "no_keep_domain "
 143 #define TOMOYO_KEYWORD_SELECT                    "select "
 144 #define TOMOYO_KEYWORD_USE_PROFILE               "use_profile "
 145 #define TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ  "ignore_global_allow_read"
 146 /* A domain definition starts with <kernel>. */
 147 #define TOMOYO_ROOT_NAME                         "<kernel>"
 148 #define TOMOYO_ROOT_NAME_LEN                     (sizeof(TOMOYO_ROOT_NAME) - 1)
 149
 150 /* Index numbers for Access Controls. */
 151 #define TOMOYO_MAC_FOR_FILE                  0  /* domain_policy.conf */
 152 #define TOMOYO_MAX_ACCEPT_ENTRY              1
 153 #define TOMOYO_VERBOSE                       2
 154 #define TOMOYO_MAX_CONTROL_INDEX             3
 155
 156 /* Structure for reading/writing policy via securityfs interfaces. */
 157 struct tomoyo_io_buffer {
 158         int (*read) (struct tomoyo_io_buffer *);
 159         int (*write) (struct tomoyo_io_buffer *);
 160         /* Exclusive lock for this structure.   */
 161         struct mutex io_sem;
 162         /* The position currently reading from. */
 163         struct list_head *read_var1;
 164         /* Extra variables for reading.         */
 165         struct list_head *read_var2;
 166         /* The position currently writing to.   */
 167         struct tomoyo_domain_info *write_var1;
 168         /* The step for reading.                */
 169         int read_step;
 170         /* Buffer for reading.                  */
 171         char *read_buf;
 172         /* EOF flag for reading.                */
 173         bool read_eof;
 174         /* Read domain ACL of specified PID?    */
 175         bool read_single_domain;
 176         /* Extra variable for reading.          */
 177         u8 read_bit;
 178         /* Bytes available for reading.         */
 179         int read_avail;
 180         /* Size of read buffer.                 */
 181         int readbuf_size;
 182         /* Buffer for writing.                  */
 183         char *write_buf;
 184         /* Bytes available for writing.         */
 185         int write_avail;
 186         /* Size of write buffer.                */
 187         int writebuf_size;
 188 };
 189
 190 /* Check whether the domain has too many ACL entries to hold. */
 191 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain);
 192 /* Transactional sprintf() for policy dump. */
 193 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 194         __attribute__ ((format(printf, 2, 3)));
 195 /* Check whether the domainname is correct. */
 196 bool tomoyo_is_correct_domain(const unsigned char *domainname,
 197                               const char *function);
 198 /* Check whether the token is correct. */
 199 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 200                             const s8 pattern_type, const s8 end_type,
 201                             const char *function);
 202 /* Check whether the token can be a domainname. */
 203 bool tomoyo_is_domain_def(const unsigned char *buffer);
 204 /* Check whether the given filename matches the given pattern. */
 205 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 206                                  const struct tomoyo_path_info *pattern);
 207 /* Read "alias" entry in exception policy. */
 208 bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head);
 209 /*
 210  * Read "initialize_domain" and "no_initialize_domain" entry
 211  * in exception policy.
 212  */
 213 bool tomoyo_read_domain_initializer_policy(struct tomoyo_io_buffer *head);
 214 /* Read "keep_domain" and "no_keep_domain" entry in exception policy. */
 215 bool tomoyo_read_domain_keeper_policy(struct tomoyo_io_buffer *head);
 216 /* Read "file_pattern" entry in exception policy. */
 217 bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head);
 218 /* Read "allow_read" entry in exception policy. */
 219 bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head);
 220 /* Read "deny_rewrite" entry in exception policy. */
 221 bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head);
 222 /* Write domain policy violation warning message to console? */
 223 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain);
 224 /* Convert double path operation to operation name. */
 225 const char *tomoyo_dp2keyword(const u8 operation);
 226 /* Get the last component of the given domainname. */
 227 const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain);
 228 /* Get warning message. */
 229 const char *tomoyo_get_msg(const bool is_enforce);
 230 /* Convert single path operation to operation name. */
 231 const char *tomoyo_sp2keyword(const u8 operation);
 232 /* Delete a domain. */
 233 int tomoyo_delete_domain(char *data);
 234 /* Create "alias" entry in exception policy. */
 235 int tomoyo_write_alias_policy(char *data, const bool is_delete);
 236 /*
 237  * Create "initialize_domain" and "no_initialize_domain" entry
 238  * in exception policy.
 239  */
 240 int tomoyo_write_domain_initializer_policy(char *data, const bool is_not,
 241                                            const bool is_delete);
 242 /* Create "keep_domain" and "no_keep_domain" entry in exception policy. */
 243 int tomoyo_write_domain_keeper_policy(char *data, const bool is_not,
 244                                       const bool is_delete);
 245 /*
 246  * Create "allow_read/write", "allow_execute", "allow_read", "allow_write",
 247  * "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir",
 248  * "allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar",
 249  * "allow_truncate", "allow_symlink", "allow_rewrite", "allow_rename" and
 250  * "allow_link" entry in domain policy.
 251  */
 252 int tomoyo_write_file_policy(char *data, struct tomoyo_domain_info *domain,
 253                              const bool is_delete);
 254 /* Create "allow_read" entry in exception policy. */
 255 int tomoyo_write_globally_readable_policy(char *data, const bool is_delete);
 256 /* Create "deny_rewrite" entry in exception policy. */
 257 int tomoyo_write_no_rewrite_policy(char *data, const bool is_delete);
 258 /* Create "file_pattern" entry in exception policy. */
 259 int tomoyo_write_pattern_policy(char *data, const bool is_delete);
 260 /* Find a domain by the given name. */
 261 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname);
 262 /* Find or create a domain by the given name. */
 263 struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
 264                                                             domainname,
 265                                                             const u8 profile);
 266 /* Check mode for specified functionality. */
 267 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 268                                 const u8 index);
 269 /* Allocate memory for structures. */
 270 void *tomoyo_alloc_acl_element(const u8 acl_type);
 271 /* Fill in "struct tomoyo_path_info" members. */
 272 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr);
 273 /* Run policy loader when /sbin/init starts. */
 274 void tomoyo_load_policy(const char *filename);
 275 /* Change "struct tomoyo_domain_info"->flags. */
 276 void tomoyo_set_domain_flag(struct tomoyo_domain_info *domain,
 277                             const bool is_delete, const u8 flags);
 278
 279 /* strcmp() for "struct tomoyo_path_info" structure. */
 280 static inline bool tomoyo_pathcmp(const struct tomoyo_path_info *a,
 281                                   const struct tomoyo_path_info *b)
 282 {
 283         return a->hash != b->hash || strcmp(a->name, b->name);
 284 }
 285
 286 /* Get type of an ACL entry. */
 287 static inline u8 tomoyo_acl_type1(struct tomoyo_acl_info *ptr)
 288 {
 289         return ptr->type & ~TOMOYO_ACL_DELETED;
 290 }
 291
 292 /* Get type of an ACL entry. */
 293 static inline u8 tomoyo_acl_type2(struct tomoyo_acl_info *ptr)
 294 {
 295         return ptr->type;
 296 }
 297
 298 /**
 299  * tomoyo_is_valid - Check whether the character is a valid char.
 300  *
 301  * @c: The character to check.
 302  *
 303  * Returns true if @c is a valid character, false otherwise.
 304  */
 305 static inline bool tomoyo_is_valid(const unsigned char c)
 306 {
 307         return c > ' ' && c < 127;
 308 }
 309
 310 /**
 311  * tomoyo_is_invalid - Check whether the character is an invalid char.
 312  *
 313  * @c: The character to check.
 314  *
 315  * Returns true if @c is an invalid character, false otherwise.
 316  */
 317 static inline bool tomoyo_is_invalid(const unsigned char c)
 318 {
 319         return c && (c <= ' ' || c >= 127);
 320 }
 321
 322 /* The list for "struct tomoyo_domain_info". */
 323 extern struct list_head tomoyo_domain_list;
 324 extern struct rw_semaphore tomoyo_domain_list_lock;
 325
 326 /* Lock for domain->acl_info_list. */
 327 extern struct rw_semaphore tomoyo_domain_acl_info_list_lock;
 328
 329 /* Has /sbin/init started? */
 330 extern bool tomoyo_policy_loaded;
 331
 332 /* The kernel's domain. */
 333 extern struct tomoyo_domain_info tomoyo_kernel_domain;
 334
 335 /**
 336  * list_for_each_cookie - iterate over a list with cookie.
 337  * @pos:        the &struct list_head to use as a loop cursor.
 338  * @cookie:     the &struct list_head to use as a cookie.
 339  * @head:       the head for your list.
 340  *
 341  * Same with list_for_each() except that this primitive uses @cookie
 342  * so that we can continue iteration.
 343  * @cookie must be NULL when iteration starts, and @cookie will become
 344  * NULL when iteration finishes.
 345  */
 346 #define list_for_each_cookie(pos, cookie, head)                       \
 347         for (({ if (!cookie)                                          \
 348                                      cookie = head; }),               \
 349              pos = (cookie)->next;                                    \
 350              prefetch(pos->next), pos != (head) || ((cookie) = NULL); \
 351              (cookie) = pos, pos = pos->next)
 352
 353 #endif /* !defined(_SECURITY_TOMOYO_COMMON_H) */