1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * security/tomoyo/environ.c
4   *
5   * Copyright (C) 2005-2011  NTT DATA CORPORATION
6   */
7  
8  #include "common.h"
9  
10  /**
11   * tomoyo_check_env_acl - Check permission for environment variable's name.
12   *
13   * @r:   Pointer to "struct tomoyo_request_info".
14   * @ptr: Pointer to "struct tomoyo_acl_info".
15   *
16   * Returns true if granted, false otherwise.
17   */
tomoyo_check_env_acl(struct tomoyo_request_info * r,const struct tomoyo_acl_info * ptr)18  static bool tomoyo_check_env_acl(struct tomoyo_request_info *r,
19  				 const struct tomoyo_acl_info *ptr)
20  {
21  	const struct tomoyo_env_acl *acl =
22  		container_of(ptr, typeof(*acl), head);
23  
24  	return tomoyo_path_matches_pattern(r->param.environ.name, acl->env);
25  }
26  
27  /**
28   * tomoyo_audit_env_log - Audit environment variable name log.
29   *
30   * @r: Pointer to "struct tomoyo_request_info".
31   *
32   * Returns 0 on success, negative value otherwise.
33   */
tomoyo_audit_env_log(struct tomoyo_request_info * r)34  static int tomoyo_audit_env_log(struct tomoyo_request_info *r)
35  {
36  	return tomoyo_supervisor(r, "misc env %s\n",
37  				 r->param.environ.name->name);
38  }
39  
40  /**
41   * tomoyo_env_perm - Check permission for environment variable's name.
42   *
43   * @r:   Pointer to "struct tomoyo_request_info".
44   * @env: The name of environment variable.
45   *
46   * Returns 0 on success, negative value otherwise.
47   *
48   * Caller holds tomoyo_read_lock().
49   */
tomoyo_env_perm(struct tomoyo_request_info * r,const char * env)50  int tomoyo_env_perm(struct tomoyo_request_info *r, const char *env)
51  {
52  	struct tomoyo_path_info environ;
53  	int error;
54  
55  	if (!env || !*env)
56  		return 0;
57  	environ.name = env;
58  	tomoyo_fill_path_info(&environ);
59  	r->param_type = TOMOYO_TYPE_ENV_ACL;
60  	r->param.environ.name = &environ;
61  	do {
62  		tomoyo_check_acl(r, tomoyo_check_env_acl);
63  		error = tomoyo_audit_env_log(r);
64  	} while (error == TOMOYO_RETRY_REQUEST);
65  	return error;
66  }
67  
68  /**
69   * tomoyo_same_env_acl - Check for duplicated "struct tomoyo_env_acl" entry.
70   *
71   * @a: Pointer to "struct tomoyo_acl_info".
72   * @b: Pointer to "struct tomoyo_acl_info".
73   *
74   * Returns true if @a == @b, false otherwise.
75   */
tomoyo_same_env_acl(const struct tomoyo_acl_info * a,const struct tomoyo_acl_info * b)76  static bool tomoyo_same_env_acl(const struct tomoyo_acl_info *a,
77  				const struct tomoyo_acl_info *b)
78  {
79  	const struct tomoyo_env_acl *p1 = container_of(a, typeof(*p1), head);
80  	const struct tomoyo_env_acl *p2 = container_of(b, typeof(*p2), head);
81  
82  	return p1->env == p2->env;
83  }
84  
85  /**
86   * tomoyo_write_env - Write "struct tomoyo_env_acl" list.
87   *
88   * @param: Pointer to "struct tomoyo_acl_param".
89   *
90   * Returns 0 on success, negative value otherwise.
91   *
92   * Caller holds tomoyo_read_lock().
93   */
tomoyo_write_env(struct tomoyo_acl_param * param)94  static int tomoyo_write_env(struct tomoyo_acl_param *param)
95  {
96  	struct tomoyo_env_acl e = { .head.type = TOMOYO_TYPE_ENV_ACL };
97  	int error = -ENOMEM;
98  	const char *data = tomoyo_read_token(param);
99  
100  	if (!tomoyo_correct_word(data) || strchr(data, '='))
101  		return -EINVAL;
102  	e.env = tomoyo_get_name(data);
103  	if (!e.env)
104  		return error;
105  	error = tomoyo_update_domain(&e.head, sizeof(e), param,
106  				  tomoyo_same_env_acl, NULL);
107  	tomoyo_put_name(e.env);
108  	return error;
109  }
110  
111  /**
112   * tomoyo_write_misc - Update environment variable list.
113   *
114   * @param: Pointer to "struct tomoyo_acl_param".
115   *
116   * Returns 0 on success, negative value otherwise.
117   */
tomoyo_write_misc(struct tomoyo_acl_param * param)118  int tomoyo_write_misc(struct tomoyo_acl_param *param)
119  {
120  	if (tomoyo_str_starts(&param->data, "env "))
121  		return tomoyo_write_env(param);
122  	return -EINVAL;
123  }
124