1 /*
2 * Copyright (c) 2019 Google Inc. All rights reserved
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files
6 * (the "Software"), to deal in the Software without restriction,
7 * including without limitation the rights to use, copy, modify, merge,
8 * publish, distribute, sublicense, and/or sell copies of the Software,
9 * and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24 #include <err.h>
25 #include <interface/smc/smc.h>
26 #include <lib/smc/smc_test.h>
27 #include <lib/trusty/trusty_app.h>
28 #include <services/smc/acl.h>
29 #include <stdbool.h>
30 #include <string.h>
31 #include <uapi/trusty_uuid.h>
32
33 /* SMC test UUID : {3c321776-548e-4978-b676-843cbf1073e5} */
34 static struct uuid smc_test_uuid = {
35 0x3c321776,
36 0x548e,
37 0x4978,
38 {0xb6, 0x76, 0x84, 0x3c, 0xbf, 0x10, 0x73, 0xe5},
39 };
40
equal_uuid(const struct uuid * a,const struct uuid * b)41 static bool equal_uuid(const struct uuid* a, const struct uuid* b) {
42 return memcmp(a, b, sizeof(struct uuid)) == 0;
43 }
44
smc_test_access_policy(uint32_t smc_nr)45 static int smc_test_access_policy(uint32_t smc_nr) {
46 /*
47 * SMC_FC_ECHO_ONE_ARG and SMC_FC64_ECHO_ONE_ARG used to test that we
48 * can limit access to smcs.
49 */
50 if (smc_nr == SMC_FC_ECHO_ONE_ARG || smc_nr == SMC_FC64_ECHO_ONE_ARG)
51 return ERR_ACCESS_DENIED;
52
53 /* SMC test has unrestricted access to all other SMCs. */
54 return NO_ERROR;
55 }
56
default_access_policy(uint32_t smc_nr)57 static int default_access_policy(uint32_t smc_nr) {
58 return ERR_ACCESS_DENIED;
59 }
60
smc_test_request_check(uint32_t smc_nr,const struct uuid * uuid,const struct smc_msg * request)61 static int smc_test_request_check(uint32_t smc_nr,
62 const struct uuid* uuid,
63 const struct smc_msg* request) {
64 if ((smc_nr == SMC_FC_ECHO_THREE_ARGS ||
65 smc_nr == SMC_FC64_ECHO_THREE_ARGS) &&
66 request->params[1] != SMC_ACCESS_CONTROL_ALLOW_ARGS) {
67 /*
68 * SMC_FC64_ECHO_THREE_ARGS is used to test that we can validate the
69 * arguments of a smcall.
70 */
71 if (request->params[1] == SMC_ACCESS_CONTROL_VALIDATE_ARGS) {
72 /*
73 * If first param is SMC_ACCESS_CONTROL_VALIDATE_ARGS, second param
74 * must be a physical address that requesting app prepared for dma.
75 */
76 paddr_t paddr = request->params[2];
77 if (!paddr || !trusty_uuid_dma_is_allowed(uuid, paddr)) {
78 return ERR_INVALID_ARGS;
79 }
80 return NO_ERROR;
81 }
82 return ERR_INVALID_ARGS;
83 }
84
85 /* SMC test is allowed to make any other request. */
86 return NO_ERROR;
87 }
88
default_request_check(uint32_t smc_nr,const struct uuid * uuid,const struct smc_msg * request)89 static int default_request_check(uint32_t smc_nr,
90 const struct uuid* uuid,
91 const struct smc_msg* request) {
92 return ERR_ACCESS_DENIED;
93 }
94
smc_load_access_policy(const struct uuid * uuid,struct smc_access_policy * policy)95 void smc_load_access_policy(const struct uuid* uuid,
96 struct smc_access_policy* policy) {
97 /* On QEMU builds, only SMC test can have access to SMC service. */
98 if (equal_uuid(uuid, &smc_test_uuid)) {
99 policy->check_access = smc_test_access_policy;
100 policy->check_request = smc_test_request_check;
101 return;
102 }
103 policy->check_access = default_access_policy;
104 policy->check_request = default_request_check;
105 }
106