drivers/tee/sandbox.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2018 Linaro Limited
   4  */
   5 #include <common.h>
   6 #include <dm.h>
   7 #include <sandboxtee.h>
   8 #include <tee.h>
   9 #include <tee/optee_ta_avb.h>
  10
  11 /*
  12  * The sandbox tee driver tries to emulate a generic Trusted Exectution
  13  * Environment (TEE) with the Trusted Application (TA) OPTEE_TA_AVB
  14  * available.
  15  */
  16
  17 static const u32 pstorage_max = 16;
  18 /**
  19  * struct ta_entry - TA entries
  20  * @uuid:               UUID of an emulated TA
  21  * @open_session        Called when a session is openened to the TA
  22  * @invoke_func         Called when a function in the TA is to be invoked
  23  *
  24  * This struct is used to register TAs in this sandbox emulation of a TEE.
  25  */
  26 struct ta_entry {
  27         struct tee_optee_ta_uuid uuid;
  28         u32 (*open_session)(struct udevice *dev, uint num_params,
  29                             struct tee_param *params);
  30         u32 (*invoke_func)(struct udevice *dev,
  31                            u32 func, uint num_params,
  32                            struct tee_param *params);
  33 };
  34
  35 #ifdef CONFIG_OPTEE_TA_AVB
  36 static u32 get_attr(uint n, uint num_params, struct tee_param *params)
  37 {
  38         if (n >= num_params)
  39                 return TEE_PARAM_ATTR_TYPE_NONE;
  40
  41         return params[n].attr;
  42 }
  43
  44 static u32 check_params(u8 p0, u8 p1, u8 p2, u8 p3, uint num_params,
  45                         struct tee_param *params)
  46 {
  47         u8 p[] = { p0, p1, p2, p3};
  48         uint n;
  49
  50         for (n = 0; n < ARRAY_SIZE(p); n++)
  51                 if (p[n] != get_attr(n, num_params, params))
  52                         goto bad_params;
  53
  54         for (; n < num_params; n++)
  55                 if (get_attr(n, num_params, params))
  56                         goto bad_params;
  57
  58         return TEE_SUCCESS;
  59
  60 bad_params:
  61         printf("Bad param attrs\n");
  62
  63         return TEE_ERROR_BAD_PARAMETERS;
  64 }
  65
  66 static u32 ta_avb_open_session(struct udevice *dev, uint num_params,
  67                                struct tee_param *params)
  68 {
  69         /*
  70          * We don't expect additional parameters when opening a session to
  71          * this TA.
  72          */
  73         return check_params(TEE_PARAM_ATTR_TYPE_NONE, TEE_PARAM_ATTR_TYPE_NONE,
  74                             TEE_PARAM_ATTR_TYPE_NONE, TEE_PARAM_ATTR_TYPE_NONE,
  75                             num_params, params);
  76 }
  77
  78 static u32 ta_avb_invoke_func(struct udevice *dev, u32 func, uint num_params,
  79                               struct tee_param *params)
  80 {
  81         struct sandbox_tee_state *state = dev_get_priv(dev);
  82         struct env_entry e, *ep;
  83         char *name;
  84         u32 res;
  85         uint slot;
  86         u64 val;
  87         char *value;
  88         u32 value_sz;
  89
  90         switch (func) {
  91         case TA_AVB_CMD_READ_ROLLBACK_INDEX:
  92                 res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
  93                                    TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT,
  94                                    TEE_PARAM_ATTR_TYPE_NONE,
  95                                    TEE_PARAM_ATTR_TYPE_NONE,
  96                                    num_params, params);
  97                 if (res)
  98                         return res;
  99
 100                 slot = params[0].u.value.a;
 101                 if (slot >= ARRAY_SIZE(state->ta_avb_rollback_indexes)) {
 102                         printf("Rollback index slot out of bounds %u\n", slot);
 103                         return TEE_ERROR_BAD_PARAMETERS;
 104                 }
 105
 106                 val = state->ta_avb_rollback_indexes[slot];
 107                 params[1].u.value.a = val >> 32;
 108                 params[1].u.value.b = val;
 109                 return TEE_SUCCESS;
 110
 111         case TA_AVB_CMD_WRITE_ROLLBACK_INDEX:
 112                 res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
 113                                    TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
 114                                    TEE_PARAM_ATTR_TYPE_NONE,
 115                                    TEE_PARAM_ATTR_TYPE_NONE,
 116                                    num_params, params);
 117                 if (res)
 118                         return res;
 119
 120                 slot = params[0].u.value.a;
 121                 if (slot >= ARRAY_SIZE(state->ta_avb_rollback_indexes)) {
 122                         printf("Rollback index slot out of bounds %u\n", slot);
 123                         return TEE_ERROR_BAD_PARAMETERS;
 124                 }
 125
 126                 val = (u64)params[1].u.value.a << 32 | params[1].u.value.b;
 127                 if (val < state->ta_avb_rollback_indexes[slot])
 128                         return TEE_ERROR_SECURITY;
 129
 130                 state->ta_avb_rollback_indexes[slot] = val;
 131                 return TEE_SUCCESS;
 132
 133         case TA_AVB_CMD_READ_LOCK_STATE:
 134                 res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_OUTPUT,
 135                                    TEE_PARAM_ATTR_TYPE_NONE,
 136                                    TEE_PARAM_ATTR_TYPE_NONE,
 137                                    TEE_PARAM_ATTR_TYPE_NONE,
 138                                    num_params, params);
 139                 if (res)
 140                         return res;
 141
 142                 params[0].u.value.a = state->ta_avb_lock_state;
 143                 return TEE_SUCCESS;
 144
 145         case TA_AVB_CMD_WRITE_LOCK_STATE:
 146                 res = check_params(TEE_PARAM_ATTR_TYPE_VALUE_INPUT,
 147                                    TEE_PARAM_ATTR_TYPE_NONE,
 148                                    TEE_PARAM_ATTR_TYPE_NONE,
 149                                    TEE_PARAM_ATTR_TYPE_NONE,
 150                                    num_params, params);
 151                 if (res)
 152                         return res;
 153
 154                 if (state->ta_avb_lock_state != params[0].u.value.a) {
 155                         state->ta_avb_lock_state = params[0].u.value.a;
 156                         memset(state->ta_avb_rollback_indexes, 0,
 157                                sizeof(state->ta_avb_rollback_indexes));
 158                 }
 159
 160                 return TEE_SUCCESS;
 161         case TA_AVB_CMD_READ_PERSIST_VALUE:
 162                 res = check_params(TEE_PARAM_ATTR_TYPE_MEMREF_INPUT,
 163                                    TEE_PARAM_ATTR_TYPE_MEMREF_INOUT,
 164                                    TEE_PARAM_ATTR_TYPE_NONE,
 165                                    TEE_PARAM_ATTR_TYPE_NONE,
 166                                    num_params, params);
 167                 if (res)
 168                         return res;
 169
 170                 name = params[0].u.memref.shm->addr;
 171
 172                 value = params[1].u.memref.shm->addr;
 173                 value_sz = params[1].u.memref.size;
 174
 175                 e.key = name;
 176                 e.data = NULL;
 177                 hsearch_r(e, ENV_FIND, &ep, &state->pstorage_htab, 0);
 178                 if (!ep)
 179                         return TEE_ERROR_ITEM_NOT_FOUND;
 180
 181                 value_sz = strlen(ep->data) + 1;
 182                 memcpy(value, ep->data, value_sz);
 183
 184                 return TEE_SUCCESS;
 185         case TA_AVB_CMD_WRITE_PERSIST_VALUE:
 186                 res = check_params(TEE_PARAM_ATTR_TYPE_MEMREF_INPUT,
 187                                    TEE_PARAM_ATTR_TYPE_MEMREF_INPUT,
 188                                    TEE_PARAM_ATTR_TYPE_NONE,
 189                                    TEE_PARAM_ATTR_TYPE_NONE,
 190                                    num_params, params);
 191                 if (res)
 192                         return res;
 193
 194                 name = params[0].u.memref.shm->addr;
 195
 196                 value = params[1].u.memref.shm->addr;
 197                 value_sz = params[1].u.memref.size;
 198
 199                 e.key = name;
 200                 e.data = NULL;
 201                 hsearch_r(e, ENV_FIND, &ep, &state->pstorage_htab, 0);
 202                 if (ep)
 203                         hdelete_r(e.key, &state->pstorage_htab, 0);
 204
 205                 e.key = name;
 206                 e.data = value;
 207                 hsearch_r(e, ENV_ENTER, &ep, &state->pstorage_htab, 0);
 208                 if (!ep)
 209                         return TEE_ERROR_OUT_OF_MEMORY;
 210
 211                 return TEE_SUCCESS;
 212
 213         default:
 214                 return TEE_ERROR_NOT_SUPPORTED;
 215         }
 216 }
 217 #endif /*OPTEE_TA_AVB*/
 218
 219 static const struct ta_entry ta_entries[] = {
 220 #ifdef CONFIG_OPTEE_TA_AVB
 221         { .uuid = TA_AVB_UUID,
 222           .open_session = ta_avb_open_session,
 223           .invoke_func = ta_avb_invoke_func,
 224         },
 225 #endif
 226 };
 227
 228 static void sandbox_tee_get_version(struct udevice *dev,
 229                                     struct tee_version_data *vers)
 230 {
 231         struct tee_version_data v = {
 232                 .gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM,
 233         };
 234
 235         *vers = v;
 236 }
 237
 238 static int sandbox_tee_close_session(struct udevice *dev, u32 session)
 239 {
 240         struct sandbox_tee_state *state = dev_get_priv(dev);
 241
 242         if (!state->ta || state->session != session)
 243                 return -EINVAL;
 244
 245         state->session = 0;
 246         state->ta = NULL;
 247
 248         return 0;
 249 }
 250
 251 static const struct ta_entry *find_ta_entry(u8 uuid[TEE_UUID_LEN])
 252 {
 253         struct tee_optee_ta_uuid u;
 254         uint n;
 255
 256         tee_optee_ta_uuid_from_octets(&u, uuid);
 257
 258         for (n = 0; n < ARRAY_SIZE(ta_entries); n++)
 259                 if (!memcmp(&u, &ta_entries[n].uuid, sizeof(u)))
 260                         return ta_entries + n;
 261
 262         return NULL;
 263 }
 264
 265 static int sandbox_tee_open_session(struct udevice *dev,
 266                                     struct tee_open_session_arg *arg,
 267                                     uint num_params, struct tee_param *params)
 268 {
 269         struct sandbox_tee_state *state = dev_get_priv(dev);
 270         const struct ta_entry *ta;
 271
 272         if (state->ta) {
 273                 printf("A session is already open\n");
 274                 return -EBUSY;
 275         }
 276
 277         ta = find_ta_entry(arg->uuid);
 278         if (!ta) {
 279                 printf("Cannot find TA\n");
 280                 arg->ret = TEE_ERROR_ITEM_NOT_FOUND;
 281                 arg->ret_origin = TEE_ORIGIN_TEE;
 282
 283                 return 0;
 284         }
 285
 286         arg->ret = ta->open_session(dev, num_params, params);
 287         arg->ret_origin = TEE_ORIGIN_TRUSTED_APP;
 288
 289         if (!arg->ret) {
 290                 state->ta = (void *)ta;
 291                 state->session = 1;
 292                 arg->session = state->session;
 293         } else {
 294                 printf("Cannot open session, TA returns error\n");
 295         }
 296
 297         return 0;
 298 }
 299
 300 static int sandbox_tee_invoke_func(struct udevice *dev,
 301                                    struct tee_invoke_arg *arg,
 302                                    uint num_params, struct tee_param *params)
 303 {
 304         struct sandbox_tee_state *state = dev_get_priv(dev);
 305         struct ta_entry *ta = state->ta;
 306
 307         if (!arg->session) {
 308                 printf("Missing session\n");
 309                 return -EINVAL;
 310         }
 311
 312         if (!ta) {
 313                 printf("TA session not available\n");
 314                 return -EINVAL;
 315         }
 316
 317         if (arg->session != state->session) {
 318                 printf("Session mismatch\n");
 319                 return -EINVAL;
 320         }
 321
 322         arg->ret = ta->invoke_func(dev, arg->func, num_params, params);
 323         arg->ret_origin = TEE_ORIGIN_TRUSTED_APP;
 324
 325         return 0;
 326 }
 327
 328 static int sandbox_tee_shm_register(struct udevice *dev, struct tee_shm *shm)
 329 {
 330         struct sandbox_tee_state *state = dev_get_priv(dev);
 331
 332         state->num_shms++;
 333
 334         return 0;
 335 }
 336
 337 static int sandbox_tee_shm_unregister(struct udevice *dev, struct tee_shm *shm)
 338 {
 339         struct sandbox_tee_state *state = dev_get_priv(dev);
 340
 341         state->num_shms--;
 342
 343         return 0;
 344 }
 345
 346 static int sandbox_tee_remove(struct udevice *dev)
 347 {
 348         struct sandbox_tee_state *state = dev_get_priv(dev);
 349
 350         hdestroy_r(&state->pstorage_htab);
 351
 352         return 0;
 353 }
 354
 355 static int sandbox_tee_probe(struct udevice *dev)
 356 {
 357         struct sandbox_tee_state *state = dev_get_priv(dev);
 358         /*
 359          * With this hastable we emulate persistent storage,
 360          * which should contain persistent values
 361          * between different sessions/command invocations.
 362          */
 363         if (!hcreate_r(pstorage_max, &state->pstorage_htab))
 364                 return TEE_ERROR_OUT_OF_MEMORY;
 365
 366         return 0;
 367 }
 368
 369 static const struct tee_driver_ops sandbox_tee_ops = {
 370         .get_version = sandbox_tee_get_version,
 371         .open_session = sandbox_tee_open_session,
 372         .close_session = sandbox_tee_close_session,
 373         .invoke_func = sandbox_tee_invoke_func,
 374         .shm_register = sandbox_tee_shm_register,
 375         .shm_unregister = sandbox_tee_shm_unregister,
 376 };
 377
 378 static const struct udevice_id sandbox_tee_match[] = {
 379         { .compatible = "sandbox,tee" },
 380         {},
 381 };
 382
 383 U_BOOT_DRIVER(sandbox_tee) = {
 384         .name = "sandbox_tee",
 385         .id = UCLASS_TEE,
 386         .of_match = sandbox_tee_match,
 387         .ops = &sandbox_tee_ops,
 388         .priv_auto      = sizeof(struct sandbox_tee_state),
 389         .probe = sandbox_tee_probe,
 390         .remove = sandbox_tee_remove,
 391 };