common.h revision a0558fc3491c0494feb8472cf6c0119e43fd9484 
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
26struct dentry;
27struct vfsmount;
28
29/* Temporary buffer for holding pathnames. */
30struct tomoyo_page_buffer {
31	char buffer[4096];
32};
33
34/* Structure for holding a token. */
35struct 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. */
55struct 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 */
71struct 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. */
85struct 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 */
116struct 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. */
124struct 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. */
157struct 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. */
191bool tomoyo_domain_quota_is_ok(struct tomoyo_domain_info * const domain);
192/* Transactional sprintf() for policy dump. */
193bool tomoyo_io_printf(struct tomoyo_io_buffer *head, const char *fmt, ...)
194	__attribute__ ((format(printf, 2, 3)));
195/* Check whether the domainname is correct. */
196bool tomoyo_is_correct_domain(const unsigned char *domainname,
197			      const char *function);
198/* Check whether the token is correct. */
199bool 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. */
203bool tomoyo_is_domain_def(const unsigned char *buffer);
204/* Check whether the given filename matches the given pattern. */
205bool tomoyo_path_matches_pattern(const struct tomoyo_path_info *filename,
206				 const struct tomoyo_path_info *pattern);
207/* Read "alias" entry in exception policy. */
208bool tomoyo_read_alias_policy(struct tomoyo_io_buffer *head);
209/*
210 * Read "initialize_domain" and "no_initialize_domain" entry
211 * in exception policy.
212 */
213bool tomoyo_read_domain_initializer_policy(struct tomoyo_io_buffer *head);
214/* Read "keep_domain" and "no_keep_domain" entry in exception policy. */
215bool tomoyo_read_domain_keeper_policy(struct tomoyo_io_buffer *head);
216/* Read "file_pattern" entry in exception policy. */
217bool tomoyo_read_file_pattern(struct tomoyo_io_buffer *head);
218/* Read "allow_read" entry in exception policy. */
219bool tomoyo_read_globally_readable_policy(struct tomoyo_io_buffer *head);
220/* Read "deny_rewrite" entry in exception policy. */
221bool tomoyo_read_no_rewrite_policy(struct tomoyo_io_buffer *head);
222/* Write domain policy violation warning message to console? */
223bool tomoyo_verbose_mode(const struct tomoyo_domain_info *domain);
224/* Convert double path operation to operation name. */
225const char *tomoyo_dp2keyword(const u8 operation);
226/* Get the last component of the given domainname. */
227const char *tomoyo_get_last_name(const struct tomoyo_domain_info *domain);
228/* Get warning message. */
229const char *tomoyo_get_msg(const bool is_enforce);
230/* Convert single path operation to operation name. */
231const char *tomoyo_sp2keyword(const u8 operation);
232/* Delete a domain. */
233int tomoyo_delete_domain(char *data);
234/* Create "alias" entry in exception policy. */
235int 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 */
240int 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. */
243int 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 */
252int tomoyo_write_file_policy(char *data, struct tomoyo_domain_info *domain,
253			     const bool is_delete);
254/* Create "allow_read" entry in exception policy. */
255int tomoyo_write_globally_readable_policy(char *data, const bool is_delete);
256/* Create "deny_rewrite" entry in exception policy. */
257int tomoyo_write_no_rewrite_policy(char *data, const bool is_delete);
258/* Create "file_pattern" entry in exception policy. */
259int tomoyo_write_pattern_policy(char *data, const bool is_delete);
260/* Find a domain by the given name. */
261struct tomoyo_domain_info *tomoyo_find_domain(const char *domainname);
262/* Find or create a domain by the given name. */
263struct tomoyo_domain_info *tomoyo_find_or_assign_new_domain(const char *
264							    domainname,
265							    const u8 profile);
266/* Check mode for specified functionality. */
267unsigned int tomoyo_check_flags(const struct tomoyo_domain_info *domain,
268				const u8 index);
269/* Allocate memory for structures. */
270void *tomoyo_alloc_acl_element(const u8 acl_type);
271/* Fill in "struct tomoyo_path_info" members. */
272void tomoyo_fill_path_info(struct tomoyo_path_info *ptr);
273/* Run policy loader when /sbin/init starts. */
274void tomoyo_load_policy(const char *filename);
275/* Change "struct tomoyo_domain_info"->flags. */
276void 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. */
280static 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. */
287static 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. */
293static 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 */
305static 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 */
317static 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". */
323extern struct list_head tomoyo_domain_list;
324extern struct rw_semaphore tomoyo_domain_list_lock;
325
326/* Lock for domain->acl_info_list. */
327extern struct rw_semaphore tomoyo_domain_acl_info_list_lock;
328
329/* Has /sbin/init started? */
330extern bool tomoyo_policy_loaded;
331
332/* The kernel's domain. */
333extern 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) */
354