drivers/tpm/tpm_tis_sandbox.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (c) 2013 Google, Inc
   4  */
   5
   6 #include <common.h>
   7 #include <dm.h>
   8 #include <tpm-v1.h>
   9 #include <asm/state.h>
  10 #include <asm/unaligned.h>
  11 #include <u-boot/crc.h>
  12 #include "sandbox_common.h"
  13
  14 #define NV_DATA_PUBLIC_PERMISSIONS_OFFSET       60
  15
  16 /*
  17  * Information about our TPM emulation. This is preserved in the sandbox
  18  * state file if enabled.
  19  */
  20 static struct tpm_state {
  21         bool valid;
  22         struct nvdata_state nvdata[NV_SEQ_COUNT];
  23 } s_state, *g_state;
  24
  25 /**
  26  * sandbox_tpm_read_state() - read the sandbox EC state from the state file
  27  *
  28  * If data is available, then blob and node will provide access to it. If
  29  * not this function sets up an empty TPM.
  30  *
  31  * @blob: Pointer to device tree blob, or NULL if no data to read
  32  * @node: Node offset to read from
  33  */
  34 static int sandbox_tpm_read_state(const void *blob, int node)
  35 {
  36         struct tpm_state *state = &s_state;
  37         const char *prop;
  38         int len;
  39         int i;
  40
  41         if (!blob)
  42                 return 0;
  43
  44         for (i = 0; i < NV_SEQ_COUNT; i++) {
  45                 struct nvdata_state *nvd = &state->nvdata[i];
  46                 char prop_name[20];
  47
  48                 sprintf(prop_name, "nvdata%d", i);
  49                 prop = fdt_getprop(blob, node, prop_name, &len);
  50                 if (len >= NV_DATA_SIZE)
  51                         return log_msg_ret("nvd", -E2BIG);
  52                 if (prop) {
  53                         memcpy(nvd->data, prop, len);
  54                         nvd->length = len;
  55                         nvd->present = true;
  56                 }
  57         }
  58
  59         s_state.valid = true;
  60
  61         return 0;
  62 }
  63
  64 /**
  65  * sandbox_tpm_write_state() - Write out our state to the state file
  66  *
  67  * The caller will ensure that there is a node ready for the state. The node
  68  * may already contain the old state, in which case it is overridden.
  69  *
  70  * @blob: Device tree blob holding state
  71  * @node: Node to write our state into
  72  */
  73 static int sandbox_tpm_write_state(void *blob, int node)
  74 {
  75         const struct tpm_state *state = g_state;
  76         int i;
  77
  78         if (!state)
  79                 return 0;
  80
  81         /*
  82          * We are guaranteed enough space to write basic properties.
  83          * We could use fdt_add_subnode() to put each set of data in its
  84          * own node - perhaps useful if we add access informaiton to each.
  85          */
  86         for (i = 0; i < NV_SEQ_COUNT; i++) {
  87                 const struct nvdata_state *nvd = &state->nvdata[i];
  88                 char prop_name[20];
  89
  90                 if (nvd->present) {
  91                         snprintf(prop_name, sizeof(prop_name), "nvdata%d", i);
  92                         fdt_setprop(blob, node, prop_name, nvd->data,
  93                                     nvd->length);
  94                 }
  95         }
  96
  97         return 0;
  98 }
  99
 100 SANDBOX_STATE_IO(sandbox_tpm, "google,sandbox-tpm", sandbox_tpm_read_state,
 101                  sandbox_tpm_write_state);
 102
 103 static void handle_cap_flag_space(u8 **datap, uint index)
 104 {
 105         struct tpm_nv_data_public pub;
 106
 107         /* TPM_NV_PER_PPWRITE */
 108         memset(&pub, '\0', sizeof(pub));
 109         pub.nv_index = __cpu_to_be32(index);
 110         pub.pcr_info_read.pcr_selection.size_of_select = __cpu_to_be16(
 111                 sizeof(pub.pcr_info_read.pcr_selection.pcr_select));
 112         pub.permission.attributes = __cpu_to_be32(1);
 113         pub.pcr_info_write = pub.pcr_info_read;
 114         memcpy(*datap, &pub, sizeof(pub));
 115         *datap += sizeof(pub);
 116 }
 117
 118 static int sandbox_tpm_xfer(struct udevice *dev, const uint8_t *sendbuf,
 119                             size_t send_size, uint8_t *recvbuf,
 120                             size_t *recv_len)
 121 {
 122         struct tpm_state *tpm = dev_get_priv(dev);
 123         uint32_t code, index, length, type;
 124         uint8_t *data;
 125         int seq;
 126
 127         code = get_unaligned_be32(sendbuf + sizeof(uint16_t) +
 128                                   sizeof(uint32_t));
 129 #ifdef DEBUG
 130         printf("tpm: %zd bytes, recv_len %zd, cmd = %x\n", send_size,
 131                *recv_len, code);
 132         print_buffer(0, sendbuf, 1, send_size, 0);
 133 #endif
 134         switch (code) {
 135         case TPM_CMD_GET_CAPABILITY:
 136                 type = get_unaligned_be32(sendbuf + 14);
 137                 switch (type) {
 138                 case TPM_CAP_FLAG:
 139                         index = get_unaligned_be32(sendbuf + 18);
 140                         printf("Get flags index %#02x\n", index);
 141                         *recv_len = 22;
 142                         memset(recvbuf, '\0', *recv_len);
 143                         data = recvbuf + TPM_HDR_LEN + sizeof(uint32_t);
 144                         switch (index) {
 145                         case FIRMWARE_NV_INDEX:
 146                                 break;
 147                         case KERNEL_NV_INDEX:
 148                                 handle_cap_flag_space(&data, index);
 149                                 *recv_len = data - recvbuf;
 150                                 break;
 151                         case TPM_CAP_FLAG_PERMANENT: {
 152                                 struct tpm_permanent_flags *pflags;
 153
 154                                 pflags = (struct tpm_permanent_flags *)data;
 155                                 memset(pflags, '\0', sizeof(*pflags));
 156                                 put_unaligned_be32(TPM_TAG_PERMANENT_FLAGS,
 157                                                    &pflags->tag);
 158                                 *recv_len = TPM_HEADER_SIZE + 4 +
 159                                                 sizeof(*pflags);
 160                                 break;
 161                         }
 162                         default:
 163                                 printf("   ** Unknown flags index %x\n", index);
 164                                 return -ENOSYS;
 165                         }
 166                         put_unaligned_be32(*recv_len, recvbuf + TPM_HDR_LEN);
 167                         break;
 168                 case TPM_CAP_NV_INDEX:
 169                         index = get_unaligned_be32(sendbuf + 18);
 170                         printf("Get cap nv index %#02x\n", index);
 171                         put_unaligned_be32(22, recvbuf + TPM_HDR_LEN);
 172                         break;
 173                 default:
 174                         printf("   ** Unknown 0x65 command type %#02x\n",
 175                                type);
 176                         return -ENOSYS;
 177                 }
 178                 break;
 179         case TPM_CMD_NV_WRITE_VALUE:
 180                 index = get_unaligned_be32(sendbuf + 10);
 181                 length = get_unaligned_be32(sendbuf + 18);
 182                 seq = sb_tpm_index_to_seq(index);
 183                 if (seq < 0)
 184                         return -EINVAL;
 185                 printf("tpm: nvwrite index=%#02x, len=%#02x\n", index, length);
 186                 sb_tpm_write_data(tpm->nvdata, seq, sendbuf, 22, length);
 187                 break;
 188         case TPM_CMD_NV_READ_VALUE: /* nvread */
 189                 index = get_unaligned_be32(sendbuf + 10);
 190                 length = get_unaligned_be32(sendbuf + 18);
 191                 seq = sb_tpm_index_to_seq(index);
 192                 if (seq < 0)
 193                         return -EINVAL;
 194                 printf("tpm: nvread index=%#02x, len=%#02x, seq=%#02x\n", index,
 195                        length, seq);
 196                 *recv_len = TPM_HDR_LEN + sizeof(uint32_t) + length;
 197                 memset(recvbuf, '\0', *recv_len);
 198                 put_unaligned_be32(length, recvbuf + TPM_HDR_LEN);
 199                 sb_tpm_read_data(tpm->nvdata, seq, recvbuf, TPM_HDR_LEN + 4,
 200                                  length);
 201                 break;
 202         case TPM_CMD_EXTEND:
 203                 *recv_len = 30;
 204                 memset(recvbuf, '\0', *recv_len);
 205                 break;
 206         case TPM_CMD_NV_DEFINE_SPACE:
 207                 index = get_unaligned_be32(sendbuf + 12);
 208                 length = get_unaligned_be32(sendbuf + 77);
 209                 seq = sb_tpm_index_to_seq(index);
 210                 if (seq < 0)
 211                         return -EINVAL;
 212                 printf("tpm: define_space index=%#02x, len=%#02x, seq=%#02x\n",
 213                        index, length, seq);
 214                 sb_tpm_define_data(tpm->nvdata, seq, length);
 215                 *recv_len = 12;
 216                 memset(recvbuf, '\0', *recv_len);
 217                 break;
 218         case 0x15: /* pcr read */
 219         case 0x5d: /* force clear */
 220         case 0x6f: /* physical enable */
 221         case 0x72: /* physical set deactivated */
 222         case 0x99: /* startup */
 223         case 0x50: /* self test full */
 224         case 0x4000000a:  /* assert physical presence */
 225                 *recv_len = 12;
 226                 memset(recvbuf, '\0', *recv_len);
 227                 break;
 228         default:
 229                 printf("Unknown tpm command %02x\n", code);
 230                 return -ENOSYS;
 231         }
 232 #ifdef DEBUG
 233         printf("tpm: rx recv_len %zd\n", *recv_len);
 234         print_buffer(0, recvbuf, 1, *recv_len, 0);
 235 #endif
 236
 237         return 0;
 238 }
 239
 240 static int sandbox_tpm_get_desc(struct udevice *dev, char *buf, int size)
 241 {
 242         if (size < 15)
 243                 return -ENOSPC;
 244
 245         return snprintf(buf, size, "sandbox TPM");
 246 }
 247
 248 static int sandbox_tpm_probe(struct udevice *dev)
 249 {
 250         struct tpm_state *tpm = dev_get_priv(dev);
 251
 252         if (s_state.valid)
 253                 memcpy(tpm, &s_state, sizeof(*tpm));
 254         g_state = tpm;
 255
 256         return 0;
 257 }
 258
 259 static int sandbox_tpm_open(struct udevice *dev)
 260 {
 261         return 0;
 262 }
 263
 264 static int sandbox_tpm_close(struct udevice *dev)
 265 {
 266         return 0;
 267 }
 268
 269 static const struct tpm_ops sandbox_tpm_ops = {
 270         .open           = sandbox_tpm_open,
 271         .close          = sandbox_tpm_close,
 272         .get_desc       = sandbox_tpm_get_desc,
 273         .xfer           = sandbox_tpm_xfer,
 274 };
 275
 276 static const struct udevice_id sandbox_tpm_ids[] = {
 277         { .compatible = "google,sandbox-tpm" },
 278         { }
 279 };
 280
 281 U_BOOT_DRIVER(google_sandbox_tpm) = {
 282         .name   = "google_sandbox_tpm",
 283         .id     = UCLASS_TPM,
 284         .of_match = sandbox_tpm_ids,
 285         .ops    = &sandbox_tpm_ops,
 286         .probe  = sandbox_tpm_probe,
 287         .priv_auto      = sizeof(struct tpm_state),
 288 };