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-pre   2009/02/01
   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         u8 is_deleted;     /* Delete flag.
  92                               0 = active.
  93                               1 = deleted but undeletable.
  94                               255 = deleted and no longer undeletable. */
  95         bool quota_warned; /* Quota warnning flag.   */
  96         /* DOMAIN_FLAGS_*. Use tomoyo_set_domain_flag() to modify. */
  97         u8 flags;
  98 };
  99
 100 /* Profile number is an integer between 0 and 255. */
 101 #define TOMOYO_MAX_PROFILES 256
 102
 103 /* Ignore "allow_read" directive in exception policy. */
 104 #define TOMOYO_DOMAIN_FLAGS_IGNORE_GLOBAL_ALLOW_READ 1
 105 /*
 106  * This domain was unable to create a new domain at tomoyo_find_next_domain()
 107  * because the name of the domain to be created was too long or
 108  * it could not allocate memory.
 109  * More than one process continued execve() without domain transition.
 110  */
 111 #define TOMOYO_DOMAIN_FLAGS_TRANSITION_FAILED        2
 112
 113 /*
 114  * Structure for "allow_read/write", "allow_execute", "allow_read",
 115  * "allow_write", "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir",
 116  * "allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar",
 117  * "allow_truncate", "allow_symlink" and "allow_rewrite" directive.
 118  */
 119 struct tomoyo_single_path_acl_record {
 120         struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_SINGLE_PATH_ACL */
 121         u16 perm;
 122         /* Pointer to single pathname. */
 123         const struct tomoyo_path_info *filename;
 124 };
 125
 126 /* Structure for "allow_rename" and "allow_link" directive. */
 127 struct tomoyo_double_path_acl_record {
 128         struct tomoyo_acl_info head; /* type = TOMOYO_TYPE_DOUBLE_PATH_ACL */
 129         u8 perm;
 130         /* Pointer to single pathname. */
 131         const struct tomoyo_path_info *filename1;
 132         /* Pointer to single pathname. */
 133         const struct tomoyo_path_info *filename2;
 134 };
 135
 136 /* Keywords for ACLs. */
 137 #define TOMOYO_KEYWORD_ALIAS                     "alias "
 138 #define TOMOYO_KEYWORD_ALLOW_READ                "allow_read "
 139 #define TOMOYO_KEYWORD_DELETE                    "delete "
 140 #define TOMOYO_KEYWORD_DENY_REWRITE              "deny_rewrite "
 141 #define TOMOYO_KEYWORD_FILE_PATTERN              "file_pattern "
 142 #define TOMOYO_KEYWORD_INITIALIZE_DOMAIN         "initialize_domain "
 143 #define TOMOYO_KEYWORD_KEEP_DOMAIN               "keep_domain "
 144 #define TOMOYO_KEYWORD_NO_INITIALIZE_DOMAIN      "no_initialize_domain "
 145 #define TOMOYO_KEYWORD_NO_KEEP_DOMAIN            "no_keep_domain "
 146 #define TOMOYO_KEYWORD_SELECT                    "select "
 147 #define TOMOYO_KEYWORD_UNDELETE                  "undelete "
 148 #define TOMOYO_KEYWORD_USE_PROFILE               "use_profile "
 149 #define TOMOYO_KEYWORD_IGNORE_GLOBAL_ALLOW_READ  "ignore_global_allow_read"
 150 /* A domain definition starts with <kernel>. */
 151 #define TOMOYO_ROOT_NAME                         "<kernel>"
 152 #define TOMOYO_ROOT_NAME_LEN                     (sizeof(TOMOYO_ROOT_NAME) - 1)
 153
 154 /* Index numbers for Access Controls. */
 155 #define TOMOYO_MAC_FOR_FILE                  0  /* domain_policy.conf */
 156 #define TOMOYO_MAX_ACCEPT_ENTRY              1
 157 #define TOMOYO_VERBOSE                       2
 158 #define TOMOYO_MAX_CONTROL_INDEX             3
 159
 160 /* Structure for reading/writing policy via securityfs interfaces. */
 161 struct tomoyo_io_buffer {
 162         int (*read) (struct tomoyo_io_buffer *);
 163         int (*write) (struct tomoyo_io_buffer *);
 164         /* Exclusive lock for this structure.   */
 165         struct mutex io_sem;
 166         /* The position currently reading from. */
 167         struct list_head *read_var1;
 168         /* Extra variables for reading.         */
 169         struct list_head *read_var2;
 170         /* The position currently writing to.   */
 171         struct tomoyo_domain_info *write_var1;
 172         /* The step for reading.                */
 173         int read_step;
 174         /* Buffer for reading.                  */
 175         char *read_buf;
 176         /* EOF flag for reading.                */
 177         bool read_eof;
 178         /* Read domain ACL of specified PID?    */
 179         bool read_single_domain;
 180         /* Extra variable for reading.          */
 181         u8 read_bit;
 182         /* Bytes available for reading.         */
 183         int read_avail;
 184         /* Size of read buffer.                 */
 185         int readbuf_size;
 186         /* Buffer for writing.                  */
 187         char *write_buf;
 188         /* Bytes available for writing.         */
 189         int write_avail;
 190         /* Size of write buffer.                */
 191         int writebuf_size;
 192 };
 193
 194 /* Check whether the domain has too many ACL entries to hold. */
 195 bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain);
 196 /* Transactional sprintf() for policy dump. */
 197 bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
 198         __attribute__ ((format(printf, 2, 3)));
 199 /* Check whether the domainname is correct. */
 200 bool tomoyo_is_correct_domain(const unsigned char *domainname,
 201                               const char *function);
 202 /* Check whether the token is correct. */
 203 bool tomoyo_is_correct_path(const char *filename, const s8 start_type,
 204                             const s8 pattern_type, const s8 end_type,
 205                             const char *function);
 206 /* Check whether the token can be a domainname. */
 207 bool tomoyo_is_domain_def(const unsigned char *buffer);
 208 /* Check whether the given filename matches the given pattern. */
 209 bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
 210                                  const struct tomoyo_path_info *pattern);
 211 /* Read "alias" entry in exception policy. */
 212 bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head);
 213 /*
 214  * Read "initialize_domain" and "no_initialize_domain" entry
 215  * in exception policy.
 216  */
 217 bool tomoyo_read_domain_initializer_policy(struct tomoyo_io_buffer *head);
 218 /* Read "keep_domain" and "no_keep_domain" entry in exception policy. */
 219 bool tomoyo_read_domain_keeper_policy(struct tomoyo_io_buffer *head);
 220 /* Read "file_pattern" entry in exception policy. */
 221 bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head);
 222 /* Read "allow_read" entry in exception policy. */
 223 bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head);
 224 /* Read "deny_rewrite" entry in exception policy. */
 225 bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head);
 226 /* Write domain policy violation warning message to console? */
 227 bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain);
 228 /* Convert double path operation to operation name. */
 229 const char *tomoyo_dp2keyword(const u8 operation);
 230 /* Get the last component of the given domainname. */
 231 const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain);
 232 /* Get warning message. */
 233 const char *tomoyo_get_msg(const bool is_enforce);
 234 /* Convert single path operation to operation name. */
 235 const char *tomoyo_sp2keyword(const u8 operation);
 236 /* Delete a domain. */
 237 int tomoyo_delete_domain(char *data);
 238 /* Create "alias" entry in exception policy. */
 239 int tomoyo_write_alias_policy(char *data, const bool is_delete);
 240 /*
 241  * Create "initialize_domain" and "no_initialize_domain" entry
 242  * in exception policy.
 243  */
 244 int tomoyo_write_domain_initializer_policy(char *data, const bool is_not,
 245                                            const bool is_delete);
 246 /* Create "keep_domain" and "no_keep_domain" entry in exception policy. */
 247 int tomoyo_write_domain_keeper_policy(char *data, const bool is_not,
 248                                       const bool is_delete);
 249 /*
 250  * Create "allow_read/write", "allow_execute", "allow_read", "allow_write",
 251  * "allow_create", "allow_unlink", "allow_mkdir", "allow_rmdir",
 252  * "allow_mkfifo", "allow_mksock", "allow_mkblock", "allow_mkchar",
 253  * "allow_truncate", "allow_symlink", "allow_rewrite", "allow_rename" and
 254  * "allow_link" entry in domain policy.
 255  */
 256 int tomoyo_write_file_policy(char *data, struct tomoyo_domain_info *domain,
 257                              const bool is_delete);
 258 /* Create "allow_read" entry in exception policy. */
 259 int tomoyo_write_globally_readable_policy(char *data, const bool is_delete);
 260 /* Create "deny_rewrite" entry in exception policy. */
 261 int tomoyo_write_no_rewrite_policy(char *data, const bool is_delete);
 262 /* Create "file_pattern" entry in exception policy. */
 263 int tomoyo_write_pattern_policy(char *data, const bool is_delete);
 264 /* Find a domain by the given name. */
 265 struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname);
 266 /* Find or create a domain by the given name. */
 267 struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
 268                                                             domainname,
 269                                                             const u8 profile);
 270 /* Undelete a domain. */
 271 struct tomoyo_domain_info *tomoyo_undelete_domain(const char *domainname);
 272 /* Check mode for specified functionality. */
 273 unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
 274                                 const u8 index);
 275 /* Allocate memory for structures. */
 276 void *tomoyo_alloc_acl_element(const u8 acl_type);
 277 /* Fill in "struct tomoyo_path_info" members. */
 278 void tomoyo_fill_path_info(struct tomoyo_path_info *ptr);
 279 /* Run policy loader when /sbin/init starts. */
 280 void tomoyo_load_policy(const char *filename);
 281 /* Change "struct tomoyo_domain_info"->flags. */
 282 void tomoyo_set_domain_flag(struct tomoyo_domain_info *domain,
 283                             const bool is_delete, const u8 flags);
 284
 285 /* strcmp() for "struct tomoyo_path_info" structure. */
 286 static inline bool tomoyo_pathcmp(const struct tomoyo_path_info *a,
 287                                   const struct tomoyo_path_info *b)
 288 {
 289         return a->hash != b->hash || strcmp(a->name, b->name);
 290 }
 291
 292 /* Get type of an ACL entry. */
 293 static inline u8 tomoyo_acl_type1(struct tomoyo_acl_info *ptr)
 294 {
 295         return ptr->type & ~TOMOYO_ACL_DELETED;
 296 }
 297
 298 /* Get type of an ACL entry. */
 299 static inline u8 tomoyo_acl_type2(struct tomoyo_acl_info *ptr)
 300 {
 301         return ptr->type;
 302 }
 303
 304 /**
 305  * tomoyo_is_valid - Check whether the character is a valid char.
 306  *
 307  * @c: The character to check.
 308  *
 309  * Returns true if @c is a valid character, false otherwise.
 310  */
 311 static inline bool tomoyo_is_valid(const unsigned char c)
 312 {
 313         return c > ' ' && c < 127;
 314 }
 315
 316 /**
 317  * tomoyo_is_invalid - Check whether the character is an invalid char.
 318  *
 319  * @c: The character to check.
 320  *
 321  * Returns true if @c is an invalid character, false otherwise.
 322  */
 323 static inline bool tomoyo_is_invalid(const unsigned char c)
 324 {
 325         return c && (c <= ' ' || c >= 127);
 326 }
 327
 328 /* The list for "struct tomoyo_domain_info". */
 329 extern struct list_head tomoyo_domain_list;
 330 extern struct rw_semaphore tomoyo_domain_list_lock;
 331
 332 /* Lock for domain->acl_info_list. */
 333 extern struct rw_semaphore tomoyo_domain_acl_info_list_lock;
 334
 335 /* Has /sbin/init started? */
 336 extern bool tomoyo_policy_loaded;
 337
 338 /* The kernel's domain. */
 339 extern struct tomoyo_domain_info tomoyo_kernel_domain;
 340
 341 /**
 342  * list_for_each_cookie - iterate over a list with cookie.
 343  * @pos:        the &struct list_head to use as a loop cursor.
 344  * @cookie:     the &struct list_head to use as a cookie.
 345  * @head:       the head for your list.
 346  *
 347  * Same with list_for_each() except that this primitive uses @cookie
 348  * so that we can continue iteration.
 349  * @cookie must be NULL when iteration starts, and @cookie will become
 350  * NULL when iteration finishes.
 351  */
 352 #define list_for_each_cookie(pos, cookie, head)                       \
 353         for (({ if (!cookie)                                          \
 354                                      cookie = head; }),               \
 355              pos = (cookie)->next;                                    \
 356              prefetch(pos->next), pos != (head) || ((cookie) = NULL); \
 357              (cookie) = pos, pos = pos->next)
 358
 359 #endif /* !defined(_SECURITY_TOMOYO_COMMON_H) */