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