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 */
18static 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 */
34static 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 */
50int 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 */
76static 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 */
94static 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 */
118int 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