2 * passthrough TPM driver
4 * Copyright (c) 2010 - 2013 IBM Corporation
6 * Stefan Berger <stefanb@us.ibm.com>
8 * Copyright (C) 2011 IAIK, Graz University of Technology
9 * Author: Andreas Niederl
11 * This library is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU Lesser General Public
13 * License as published by the Free Software Foundation; either
14 * version 2 of the License, or (at your option) any later version.
16 * This library is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * Lesser General Public License for more details.
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this library; if not, see <http://www.gnu.org/licenses/>
27 #include "qemu-common.h"
28 #include "qapi/error.h"
29 #include "qemu/sockets.h"
30 #include "sysemu/tpm_backend.h"
33 #include "hw/i386/pc.h"
34 #include "sysemu/tpm_backend_int.h"
37 /* #define DEBUG_TPM */
40 #define DPRINTF(fmt, ...) \
41 do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
43 #define DPRINTF(fmt, ...) \
47 #define TYPE_TPM_PASSTHROUGH "tpm-passthrough"
48 #define TPM_PASSTHROUGH(obj) \
49 OBJECT_CHECK(TPMPassthruState, (obj), TYPE_TPM_PASSTHROUGH)
51 static const TPMDriverOps tpm_passthrough_driver
;
54 typedef struct TPMPassthruThreadParams
{
57 TPMRecvDataCB
*recv_data_callback
;
59 } TPMPassthruThreadParams
;
61 struct TPMPassthruState
{
66 TPMPassthruThreadParams tpm_thread_params
;
73 bool had_startup_error
;
76 typedef struct TPMPassthruState TPMPassthruState
;
78 #define TPM_PASSTHROUGH_DEFAULT_DEVICE "/dev/tpm0"
82 static void tpm_passthrough_cancel_cmd(TPMBackend
*tb
);
84 static int tpm_passthrough_unix_write(int fd
, const uint8_t *buf
, uint32_t len
)
86 return send_all(fd
, buf
, len
);
89 static int tpm_passthrough_unix_read(int fd
, uint8_t *buf
, uint32_t len
)
91 return recv_all(fd
, buf
, len
, true);
94 static uint32_t tpm_passthrough_get_size_from_buffer(const uint8_t *buf
)
96 struct tpm_resp_hdr
*resp
= (struct tpm_resp_hdr
*)buf
;
98 return be32_to_cpu(resp
->len
);
102 * Write an error message in the given output buffer.
104 static void tpm_write_fatal_error_response(uint8_t *out
, uint32_t out_len
)
106 if (out_len
>= sizeof(struct tpm_resp_hdr
)) {
107 struct tpm_resp_hdr
*resp
= (struct tpm_resp_hdr
*)out
;
109 resp
->tag
= cpu_to_be16(TPM_TAG_RSP_COMMAND
);
110 resp
->len
= cpu_to_be32(sizeof(struct tpm_resp_hdr
));
111 resp
->errcode
= cpu_to_be32(TPM_FAIL
);
115 static int tpm_passthrough_unix_tx_bufs(TPMPassthruState
*tpm_pt
,
116 const uint8_t *in
, uint32_t in_len
,
117 uint8_t *out
, uint32_t out_len
)
121 tpm_pt
->tpm_op_canceled
= false;
122 tpm_pt
->tpm_executing
= true;
124 ret
= tpm_passthrough_unix_write(tpm_pt
->tpm_fd
, in
, in_len
);
126 if (!tpm_pt
->tpm_op_canceled
||
127 (tpm_pt
->tpm_op_canceled
&& errno
!= ECANCELED
)) {
128 error_report("tpm_passthrough: error while transmitting data "
130 strerror(errno
), errno
);
135 tpm_pt
->tpm_executing
= false;
137 ret
= tpm_passthrough_unix_read(tpm_pt
->tpm_fd
, out
, out_len
);
139 if (!tpm_pt
->tpm_op_canceled
||
140 (tpm_pt
->tpm_op_canceled
&& errno
!= ECANCELED
)) {
141 error_report("tpm_passthrough: error while reading data from "
143 strerror(errno
), errno
);
145 } else if (ret
< sizeof(struct tpm_resp_hdr
) ||
146 tpm_passthrough_get_size_from_buffer(out
) != ret
) {
148 error_report("tpm_passthrough: received invalid response "
149 "packet from TPM\n");
154 tpm_write_fatal_error_response(out
, out_len
);
157 tpm_pt
->tpm_executing
= false;
162 static int tpm_passthrough_unix_transfer(TPMPassthruState
*tpm_pt
,
163 const TPMLocality
*locty_data
)
165 return tpm_passthrough_unix_tx_bufs(tpm_pt
,
166 locty_data
->w_buffer
.buffer
,
167 locty_data
->w_offset
,
168 locty_data
->r_buffer
.buffer
,
169 locty_data
->r_buffer
.size
);
172 static void tpm_passthrough_worker_thread(gpointer data
,
175 TPMPassthruThreadParams
*thr_parms
= user_data
;
176 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(thr_parms
->tb
);
177 TPMBackendCmd cmd
= (TPMBackendCmd
)data
;
179 DPRINTF("tpm_passthrough: processing command type %d\n", cmd
);
182 case TPM_BACKEND_CMD_PROCESS_CMD
:
183 tpm_passthrough_unix_transfer(tpm_pt
,
184 thr_parms
->tpm_state
->locty_data
);
186 thr_parms
->recv_data_callback(thr_parms
->tpm_state
,
187 thr_parms
->tpm_state
->locty_number
);
189 case TPM_BACKEND_CMD_INIT
:
190 case TPM_BACKEND_CMD_END
:
191 case TPM_BACKEND_CMD_TPM_RESET
:
198 * Start the TPM (thread). If it had been started before, then terminate
199 * and start it again.
201 static int tpm_passthrough_startup_tpm(TPMBackend
*tb
)
203 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
205 /* terminate a running TPM */
206 tpm_backend_thread_end(&tpm_pt
->tbt
);
208 tpm_backend_thread_create(&tpm_pt
->tbt
,
209 tpm_passthrough_worker_thread
,
210 &tpm_pt
->tpm_thread_params
);
215 static void tpm_passthrough_reset(TPMBackend
*tb
)
217 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
219 DPRINTF("tpm_passthrough: CALL TO TPM_RESET!\n");
221 tpm_passthrough_cancel_cmd(tb
);
223 tpm_backend_thread_end(&tpm_pt
->tbt
);
225 tpm_pt
->had_startup_error
= false;
228 static int tpm_passthrough_init(TPMBackend
*tb
, TPMState
*s
,
229 TPMRecvDataCB
*recv_data_cb
)
231 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
233 tpm_pt
->tpm_thread_params
.tpm_state
= s
;
234 tpm_pt
->tpm_thread_params
.recv_data_callback
= recv_data_cb
;
235 tpm_pt
->tpm_thread_params
.tb
= tb
;
240 static bool tpm_passthrough_get_tpm_established_flag(TPMBackend
*tb
)
245 static bool tpm_passthrough_get_startup_error(TPMBackend
*tb
)
247 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
249 return tpm_pt
->had_startup_error
;
252 static size_t tpm_passthrough_realloc_buffer(TPMSizedBuffer
*sb
)
254 size_t wanted_size
= 4096; /* Linux tpm.c buffer size */
256 if (sb
->size
!= wanted_size
) {
257 sb
->buffer
= g_realloc(sb
->buffer
, wanted_size
);
258 sb
->size
= wanted_size
;
263 static void tpm_passthrough_deliver_request(TPMBackend
*tb
)
265 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
267 tpm_backend_thread_deliver_request(&tpm_pt
->tbt
);
270 static void tpm_passthrough_cancel_cmd(TPMBackend
*tb
)
272 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
276 * As of Linux 3.7 the tpm_tis driver does not properly cancel
277 * commands on all TPM manufacturers' TPMs.
278 * Only cancel if we're busy so we don't cancel someone else's
279 * command, e.g., a command executed on the host.
281 if (tpm_pt
->tpm_executing
) {
282 if (tpm_pt
->cancel_fd
>= 0) {
283 n
= write(tpm_pt
->cancel_fd
, "-", 1);
285 error_report("Canceling TPM command failed: %s\n",
288 tpm_pt
->tpm_op_canceled
= true;
291 error_report("Cannot cancel TPM command due to missing "
292 "TPM sysfs cancel entry");
297 static const char *tpm_passthrough_create_desc(void)
299 return "Passthrough TPM backend driver";
303 * A basic test of a TPM device. We expect a well formatted response header
304 * (error response is fine) within one second.
306 static int tpm_passthrough_test_tpmdev(int fd
)
308 struct tpm_req_hdr req
= {
309 .tag
= cpu_to_be16(TPM_TAG_RQU_COMMAND
),
310 .len
= cpu_to_be32(sizeof(req
)),
311 .ordinal
= cpu_to_be32(TPM_ORD_GetTicks
),
313 struct tpm_resp_hdr
*resp
;
316 struct timeval tv
= {
320 unsigned char buf
[1024];
322 n
= write(fd
, &req
, sizeof(req
));
326 if (n
!= sizeof(req
)) {
331 FD_SET(fd
, &readfds
);
333 /* wait for a second */
334 n
= select(fd
+ 1, &readfds
, NULL
, NULL
, &tv
);
339 n
= read(fd
, &buf
, sizeof(buf
));
340 if (n
< sizeof(struct tpm_resp_hdr
)) {
344 resp
= (struct tpm_resp_hdr
*)buf
;
345 /* check the header */
346 if (be16_to_cpu(resp
->tag
) != TPM_TAG_RSP_COMMAND
||
347 be32_to_cpu(resp
->len
) != n
) {
355 * Check whether the given base path, e.g., /sys/class/misc/tpm0/device,
356 * is the sysfs directory of a TPM. A TPM sysfs directory should be uniquely
357 * recognizable by the file entries 'pcrs' and 'cancel'.
358 * Upon success 'true' is returned and the basebath buffer has '/cancel'
361 static bool tpm_passthrough_check_sysfs_cancel(char *basepath
, size_t bufsz
)
366 snprintf(path
, sizeof(path
), "%s/pcrs", basepath
);
367 if (stat(path
, &statbuf
) == -1 || !S_ISREG(statbuf
.st_mode
)) {
371 snprintf(path
, sizeof(path
), "%s/cancel", basepath
);
372 if (stat(path
, &statbuf
) == -1 || !S_ISREG(statbuf
.st_mode
)) {
376 strncpy(basepath
, path
, bufsz
);
382 * Unless path or file descriptor set has been provided by user,
383 * determine the sysfs cancel file following kernel documentation
384 * in Documentation/ABI/stable/sysfs-class-tpm.
386 static int tpm_passthrough_open_sysfs_cancel(TPMBackend
*tb
)
392 struct dirent entry
, *result
;
395 if (tb
->cancel_path
) {
396 fd
= qemu_open(tb
->cancel_path
, O_WRONLY
);
398 error_report("Could not open TPM cancel path : %s",
404 snprintf(path
, sizeof(path
), "/sys/class/misc");
405 pnp_dir
= opendir(path
);
406 if (pnp_dir
!= NULL
) {
407 while (readdir_r(pnp_dir
, &entry
, &result
) == 0 &&
410 * only allow /sys/class/misc/tpm%u type of paths
412 if (sscanf(entry
.d_name
, "tpm%u%n", &idx
, &len
) < 1 ||
413 len
<= strlen("tpm") ||
414 len
!= strlen(entry
.d_name
)) {
418 snprintf(path
, sizeof(path
), "/sys/class/misc/%s/device",
420 if (!tpm_passthrough_check_sysfs_cancel(path
, sizeof(path
))) {
424 fd
= qemu_open(path
, O_WRONLY
);
431 tb
->cancel_path
= g_strdup(path
);
437 static int tpm_passthrough_handle_device_opts(QemuOpts
*opts
, TPMBackend
*tb
)
439 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
442 value
= qemu_opt_get(opts
, "cancel-path");
444 tb
->cancel_path
= g_strdup(value
);
447 value
= qemu_opt_get(opts
, "path");
449 value
= TPM_PASSTHROUGH_DEFAULT_DEVICE
;
452 tpm_pt
->tpm_dev
= g_strdup(value
);
454 tb
->path
= g_strdup(tpm_pt
->tpm_dev
);
456 tpm_pt
->tpm_fd
= qemu_open(tpm_pt
->tpm_dev
, O_RDWR
);
457 if (tpm_pt
->tpm_fd
< 0) {
458 error_report("Cannot access TPM device using '%s': %s\n",
459 tpm_pt
->tpm_dev
, strerror(errno
));
460 goto err_free_parameters
;
463 if (tpm_passthrough_test_tpmdev(tpm_pt
->tpm_fd
)) {
464 error_report("'%s' is not a TPM device.\n",
466 goto err_close_tpmdev
;
472 qemu_close(tpm_pt
->tpm_fd
);
479 g_free(tpm_pt
->tpm_dev
);
480 tpm_pt
->tpm_dev
= NULL
;
485 static TPMBackend
*tpm_passthrough_create(QemuOpts
*opts
, const char *id
)
487 Object
*obj
= object_new(TYPE_TPM_PASSTHROUGH
);
488 TPMBackend
*tb
= TPM_BACKEND(obj
);
489 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
491 tb
->id
= g_strdup(id
);
492 /* let frontend set the fe_model to proper value */
495 tb
->ops
= &tpm_passthrough_driver
;
497 if (tpm_passthrough_handle_device_opts(opts
, tb
)) {
501 tpm_pt
->cancel_fd
= tpm_passthrough_open_sysfs_cancel(tb
);
502 if (tpm_pt
->cancel_fd
< 0) {
514 static void tpm_passthrough_destroy(TPMBackend
*tb
)
516 TPMPassthruState
*tpm_pt
= TPM_PASSTHROUGH(tb
);
518 tpm_passthrough_cancel_cmd(tb
);
520 tpm_backend_thread_end(&tpm_pt
->tbt
);
522 qemu_close(tpm_pt
->tpm_fd
);
523 qemu_close(tpm_pt
->cancel_fd
);
527 g_free(tb
->cancel_path
);
528 g_free(tpm_pt
->tpm_dev
);
531 static const TPMDriverOps tpm_passthrough_driver
= {
532 .type
= TPM_TYPE_PASSTHROUGH
,
533 .desc
= tpm_passthrough_create_desc
,
534 .create
= tpm_passthrough_create
,
535 .destroy
= tpm_passthrough_destroy
,
536 .init
= tpm_passthrough_init
,
537 .startup_tpm
= tpm_passthrough_startup_tpm
,
538 .realloc_buffer
= tpm_passthrough_realloc_buffer
,
539 .reset
= tpm_passthrough_reset
,
540 .had_startup_error
= tpm_passthrough_get_startup_error
,
541 .deliver_request
= tpm_passthrough_deliver_request
,
542 .cancel_cmd
= tpm_passthrough_cancel_cmd
,
543 .get_tpm_established_flag
= tpm_passthrough_get_tpm_established_flag
,
546 static void tpm_passthrough_inst_init(Object
*obj
)
550 static void tpm_passthrough_inst_finalize(Object
*obj
)
554 static void tpm_passthrough_class_init(ObjectClass
*klass
, void *data
)
556 TPMBackendClass
*tbc
= TPM_BACKEND_CLASS(klass
);
558 tbc
->ops
= &tpm_passthrough_driver
;
561 static const TypeInfo tpm_passthrough_info
= {
562 .name
= TYPE_TPM_PASSTHROUGH
,
563 .parent
= TYPE_TPM_BACKEND
,
564 .instance_size
= sizeof(TPMPassthruState
),
565 .class_init
= tpm_passthrough_class_init
,
566 .instance_init
= tpm_passthrough_inst_init
,
567 .instance_finalize
= tpm_passthrough_inst_finalize
,
570 static void tpm_passthrough_register(void)
572 type_register_static(&tpm_passthrough_info
);
573 tpm_register_driver(&tpm_passthrough_driver
);
576 type_init(tpm_passthrough_register
)