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