--- /dev/null
+/*
+ * passthrough TPM driver
+ *
+ * Copyright (c) 2010 - 2013 IBM Corporation
+ * Authors:
+ * Stefan Berger <stefanb@us.ibm.com>
+ *
+ * Copyright (C) 2011 IAIK, Graz University of Technology
+ * Author: Andreas Niederl
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ */
+
+#include <dirent.h>
+
+#include "qemu-common.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/sockets.h"
+#include "sysemu/tpm_backend.h"
+#include "tpm_int.h"
+#include "hw/hw.h"
+#include "hw/i386/pc.h"
+#include "sysemu/tpm_backend_int.h"
+#include "tpm_tis.h"
+#include "tpm_util.h"
+
+#define DEBUG_TPM 0
+
+#define DPRINTF(fmt, ...) do { \
+ if (DEBUG_TPM) { \
+ fprintf(stderr, fmt, ## __VA_ARGS__); \
+ } \
+} while (0);
+
+#define TYPE_TPM_PASSTHROUGH "tpm-passthrough"
+#define TPM_PASSTHROUGH(obj) \
+ OBJECT_CHECK(TPMPassthruState, (obj), TYPE_TPM_PASSTHROUGH)
+
+static const TPMDriverOps tpm_passthrough_driver;
+
+/* data structures */
+typedef struct TPMPassthruThreadParams {
+ TPMState *tpm_state;
+
+ TPMRecvDataCB *recv_data_callback;
+ TPMBackend *tb;
+} TPMPassthruThreadParams;
+
+struct TPMPassthruState {
+ TPMBackend parent;
+
+ TPMBackendThread tbt;
+
+ TPMPassthruThreadParams tpm_thread_params;
+
+ char *tpm_dev;
+ int tpm_fd;
+ bool tpm_executing;
+ bool tpm_op_canceled;
+ int cancel_fd;
+ bool had_startup_error;
+
+ TPMVersion tpm_version;
+};
+
+typedef struct TPMPassthruState TPMPassthruState;
+
+#define TPM_PASSTHROUGH_DEFAULT_DEVICE "/dev/tpm0"
+
+/* functions */
+
+static void tpm_passthrough_cancel_cmd(TPMBackend *tb);
+
+static int tpm_passthrough_unix_write(int fd, const uint8_t *buf, uint32_t len)
+{
+ return send_all(fd, buf, len);
+}
+
+static int tpm_passthrough_unix_read(int fd, uint8_t *buf, uint32_t len)
+{
+ return recv_all(fd, buf, len, true);
+}
+
+static uint32_t tpm_passthrough_get_size_from_buffer(const uint8_t *buf)
+{
+ struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)buf;
+
+ return be32_to_cpu(resp->len);
+}
+
+/*
+ * Write an error message in the given output buffer.
+ */
+static void tpm_write_fatal_error_response(uint8_t *out, uint32_t out_len)
+{
+ if (out_len >= sizeof(struct tpm_resp_hdr)) {
+ struct tpm_resp_hdr *resp = (struct tpm_resp_hdr *)out;
+
+ resp->tag = cpu_to_be16(TPM_TAG_RSP_COMMAND);
+ resp->len = cpu_to_be32(sizeof(struct tpm_resp_hdr));
+ resp->errcode = cpu_to_be32(TPM_FAIL);
+ }
+}
+
+static bool tpm_passthrough_is_selftest(const uint8_t *in, uint32_t in_len)
+{
+ struct tpm_req_hdr *hdr = (struct tpm_req_hdr *)in;
+
+ if (in_len >= sizeof(*hdr)) {
+ return (be32_to_cpu(hdr->ordinal) == TPM_ORD_ContinueSelfTest);
+ }
+
+ return false;
+}
+
+static int tpm_passthrough_unix_tx_bufs(TPMPassthruState *tpm_pt,
+ const uint8_t *in, uint32_t in_len,
+ uint8_t *out, uint32_t out_len,
+ bool *selftest_done)
+{
+ int ret;
+ bool is_selftest;
+ const struct tpm_resp_hdr *hdr;
+
+ tpm_pt->tpm_op_canceled = false;
+ tpm_pt->tpm_executing = true;
+ *selftest_done = false;
+
+ is_selftest = tpm_passthrough_is_selftest(in, in_len);
+
+ ret = tpm_passthrough_unix_write(tpm_pt->tpm_fd, in, in_len);
+ if (ret != in_len) {
+ if (!tpm_pt->tpm_op_canceled ||
+ (tpm_pt->tpm_op_canceled && errno != ECANCELED)) {
+ error_report("tpm_passthrough: error while transmitting data "
+ "to TPM: %s (%i)",
+ strerror(errno), errno);
+ }
+ goto err_exit;
+ }
+
+ tpm_pt->tpm_executing = false;
+
+ ret = tpm_passthrough_unix_read(tpm_pt->tpm_fd, out, out_len);
+ if (ret < 0) {
+ if (!tpm_pt->tpm_op_canceled ||
+ (tpm_pt->tpm_op_canceled && errno != ECANCELED)) {
+ error_report("tpm_passthrough: error while reading data from "
+ "TPM: %s (%i)",
+ strerror(errno), errno);
+ }
+ } else if (ret < sizeof(struct tpm_resp_hdr) ||
+ tpm_passthrough_get_size_from_buffer(out) != ret) {
+ ret = -1;
+ error_report("tpm_passthrough: received invalid response "
+ "packet from TPM");
+ }
+
+ if (is_selftest && (ret >= sizeof(struct tpm_resp_hdr))) {
+ hdr = (struct tpm_resp_hdr *)out;
+ *selftest_done = (be32_to_cpu(hdr->errcode) == 0);
+ }
+
+err_exit:
+ if (ret < 0) {
+ tpm_write_fatal_error_response(out, out_len);
+ }
+
+ tpm_pt->tpm_executing = false;
+
+ return ret;
+}
+
+static int tpm_passthrough_unix_transfer(TPMPassthruState *tpm_pt,
+ const TPMLocality *locty_data,
+ bool *selftest_done)
+{
+ return tpm_passthrough_unix_tx_bufs(tpm_pt,
+ locty_data->w_buffer.buffer,
+ locty_data->w_offset,
+ locty_data->r_buffer.buffer,
+ locty_data->r_buffer.size,
+ selftest_done);
+}
+
+static void tpm_passthrough_worker_thread(gpointer data,
+ gpointer user_data)
+{
+ TPMPassthruThreadParams *thr_parms = user_data;
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(thr_parms->tb);
+ TPMBackendCmd cmd = (TPMBackendCmd)data;
+ bool selftest_done = false;
+
+ DPRINTF("tpm_passthrough: processing command type %d\n", cmd);
+
+ switch (cmd) {
+ case TPM_BACKEND_CMD_PROCESS_CMD:
+ tpm_passthrough_unix_transfer(tpm_pt,
+ thr_parms->tpm_state->locty_data,
+ &selftest_done);
+
+ thr_parms->recv_data_callback(thr_parms->tpm_state,
+ thr_parms->tpm_state->locty_number,
+ selftest_done);
+ break;
+ case TPM_BACKEND_CMD_INIT:
+ case TPM_BACKEND_CMD_END:
+ case TPM_BACKEND_CMD_TPM_RESET:
+ /* nothing to do */
+ break;
+ }
+}
+
+/*
+ * Start the TPM (thread). If it had been started before, then terminate
+ * and start it again.
+ */
+static int tpm_passthrough_startup_tpm(TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ /* terminate a running TPM */
+ tpm_backend_thread_end(&tpm_pt->tbt);
+
+ tpm_backend_thread_create(&tpm_pt->tbt,
+ tpm_passthrough_worker_thread,
+ &tpm_pt->tpm_thread_params);
+
+ return 0;
+}
+
+static void tpm_passthrough_reset(TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ DPRINTF("tpm_passthrough: CALL TO TPM_RESET!\n");
+
+ tpm_passthrough_cancel_cmd(tb);
+
+ tpm_backend_thread_end(&tpm_pt->tbt);
+
+ tpm_pt->had_startup_error = false;
+}
+
+static int tpm_passthrough_init(TPMBackend *tb, TPMState *s,
+ TPMRecvDataCB *recv_data_cb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ tpm_pt->tpm_thread_params.tpm_state = s;
+ tpm_pt->tpm_thread_params.recv_data_callback = recv_data_cb;
+ tpm_pt->tpm_thread_params.tb = tb;
+
+ return 0;
+}
+
+static bool tpm_passthrough_get_tpm_established_flag(TPMBackend *tb)
+{
+ return false;
+}
+
+static int tpm_passthrough_reset_tpm_established_flag(TPMBackend *tb,
+ uint8_t locty)
+{
+ /* only a TPM 2.0 will support this */
+ return 0;
+}
+
+static bool tpm_passthrough_get_startup_error(TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ return tpm_pt->had_startup_error;
+}
+
+static size_t tpm_passthrough_realloc_buffer(TPMSizedBuffer *sb)
+{
+ size_t wanted_size = 4096; /* Linux tpm.c buffer size */
+
+ if (sb->size != wanted_size) {
+ sb->buffer = g_realloc(sb->buffer, wanted_size);
+ sb->size = wanted_size;
+ }
+ return sb->size;
+}
+
+static void tpm_passthrough_deliver_request(TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ tpm_backend_thread_deliver_request(&tpm_pt->tbt);
+}
+
+static void tpm_passthrough_cancel_cmd(TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+ int n;
+
+ /*
+ * As of Linux 3.7 the tpm_tis driver does not properly cancel
+ * commands on all TPM manufacturers' TPMs.
+ * Only cancel if we're busy so we don't cancel someone else's
+ * command, e.g., a command executed on the host.
+ */
+ if (tpm_pt->tpm_executing) {
+ if (tpm_pt->cancel_fd >= 0) {
+ n = write(tpm_pt->cancel_fd, "-", 1);
+ if (n != 1) {
+ error_report("Canceling TPM command failed: %s",
+ strerror(errno));
+ } else {
+ tpm_pt->tpm_op_canceled = true;
+ }
+ } else {
+ error_report("Cannot cancel TPM command due to missing "
+ "TPM sysfs cancel entry");
+ }
+ }
+}
+
+static const char *tpm_passthrough_create_desc(void)
+{
+ return "Passthrough TPM backend driver";
+}
+
+static TPMVersion tpm_passthrough_get_tpm_version(TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ return tpm_pt->tpm_version;
+}
+
+/*
+ * Unless path or file descriptor set has been provided by user,
+ * determine the sysfs cancel file following kernel documentation
+ * in Documentation/ABI/stable/sysfs-class-tpm.
+ * From /dev/tpm0 create /sys/class/misc/tpm0/device/cancel
+ */
+static int tpm_passthrough_open_sysfs_cancel(TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+ int fd = -1;
+ char *dev;
+ char path[PATH_MAX];
+
+ if (tb->cancel_path) {
+ fd = qemu_open(tb->cancel_path, O_WRONLY);
+ if (fd < 0) {
+ error_report("Could not open TPM cancel path : %s",
+ strerror(errno));
+ }
+ return fd;
+ }
+
+ dev = strrchr(tpm_pt->tpm_dev, '/');
+ if (dev) {
+ dev++;
+ if (snprintf(path, sizeof(path), "/sys/class/misc/%s/device/cancel",
+ dev) < sizeof(path)) {
+ fd = qemu_open(path, O_WRONLY);
+ if (fd >= 0) {
+ tb->cancel_path = g_strdup(path);
+ } else {
+ error_report("tpm_passthrough: Could not open TPM cancel "
+ "path %s : %s", path, strerror(errno));
+ }
+ }
+ } else {
+ error_report("tpm_passthrough: Bad TPM device path %s",
+ tpm_pt->tpm_dev);
+ }
+
+ return fd;
+}
+
+static int tpm_passthrough_handle_device_opts(QemuOpts *opts, TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+ const char *value;
+
+ value = qemu_opt_get(opts, "cancel-path");
+ tb->cancel_path = g_strdup(value);
+
+ value = qemu_opt_get(opts, "path");
+ if (!value) {
+ value = TPM_PASSTHROUGH_DEFAULT_DEVICE;
+ }
+
+ tpm_pt->tpm_dev = g_strdup(value);
+
+ tb->path = g_strdup(tpm_pt->tpm_dev);
+
+ tpm_pt->tpm_fd = qemu_open(tpm_pt->tpm_dev, O_RDWR);
+ if (tpm_pt->tpm_fd < 0) {
+ error_report("Cannot access TPM device using '%s': %s",
+ tpm_pt->tpm_dev, strerror(errno));
+ goto err_free_parameters;
+ }
+
+ if (tpm_util_test_tpmdev(tpm_pt->tpm_fd, &tpm_pt->tpm_version)) {
+ error_report("'%s' is not a TPM device.",
+ tpm_pt->tpm_dev);
+ goto err_close_tpmdev;
+ }
+
+ return 0;
+
+ err_close_tpmdev:
+ qemu_close(tpm_pt->tpm_fd);
+ tpm_pt->tpm_fd = -1;
+
+ err_free_parameters:
+ g_free(tb->path);
+ tb->path = NULL;
+
+ g_free(tpm_pt->tpm_dev);
+ tpm_pt->tpm_dev = NULL;
+
+ return 1;
+}
+
+static TPMBackend *tpm_passthrough_create(QemuOpts *opts, const char *id)
+{
+ Object *obj = object_new(TYPE_TPM_PASSTHROUGH);
+ TPMBackend *tb = TPM_BACKEND(obj);
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ tb->id = g_strdup(id);
+ /* let frontend set the fe_model to proper value */
+ tb->fe_model = -1;
+
+ tb->ops = &tpm_passthrough_driver;
+
+ if (tpm_passthrough_handle_device_opts(opts, tb)) {
+ goto err_exit;
+ }
+
+ tpm_pt->cancel_fd = tpm_passthrough_open_sysfs_cancel(tb);
+ if (tpm_pt->cancel_fd < 0) {
+ goto err_exit;
+ }
+
+ return tb;
+
+err_exit:
+ g_free(tb->id);
+
+ return NULL;
+}
+
+static void tpm_passthrough_destroy(TPMBackend *tb)
+{
+ TPMPassthruState *tpm_pt = TPM_PASSTHROUGH(tb);
+
+ tpm_passthrough_cancel_cmd(tb);
+
+ tpm_backend_thread_end(&tpm_pt->tbt);
+
+ qemu_close(tpm_pt->tpm_fd);
+ qemu_close(tpm_pt->cancel_fd);
+
+ g_free(tb->id);
+ g_free(tb->path);
+ g_free(tb->cancel_path);
+ g_free(tpm_pt->tpm_dev);
+}
+
+static const QemuOptDesc tpm_passthrough_cmdline_opts[] = {
+ TPM_STANDARD_CMDLINE_OPTS,
+ {
+ .name = "cancel-path",
+ .type = QEMU_OPT_STRING,
+ .help = "Sysfs file entry for canceling TPM commands",
+ },
+ {
+ .name = "path",
+ .type = QEMU_OPT_STRING,
+ .help = "Path to TPM device on the host",
+ },
+ { /* end of list */ },
+};
+
+static const TPMDriverOps tpm_passthrough_driver = {
+ .type = TPM_TYPE_PASSTHROUGH,
+ .opts = tpm_passthrough_cmdline_opts,
+ .desc = tpm_passthrough_create_desc,
+ .create = tpm_passthrough_create,
+ .destroy = tpm_passthrough_destroy,
+ .init = tpm_passthrough_init,
+ .startup_tpm = tpm_passthrough_startup_tpm,
+ .realloc_buffer = tpm_passthrough_realloc_buffer,
+ .reset = tpm_passthrough_reset,
+ .had_startup_error = tpm_passthrough_get_startup_error,
+ .deliver_request = tpm_passthrough_deliver_request,
+ .cancel_cmd = tpm_passthrough_cancel_cmd,
+ .get_tpm_established_flag = tpm_passthrough_get_tpm_established_flag,
+ .reset_tpm_established_flag = tpm_passthrough_reset_tpm_established_flag,
+ .get_tpm_version = tpm_passthrough_get_tpm_version,
+};
+
+static void tpm_passthrough_inst_init(Object *obj)
+{
+}
+
+static void tpm_passthrough_inst_finalize(Object *obj)
+{
+}
+
+static void tpm_passthrough_class_init(ObjectClass *klass, void *data)
+{
+ TPMBackendClass *tbc = TPM_BACKEND_CLASS(klass);
+
+ tbc->ops = &tpm_passthrough_driver;
+}
+
+static const TypeInfo tpm_passthrough_info = {
+ .name = TYPE_TPM_PASSTHROUGH,
+ .parent = TYPE_TPM_BACKEND,
+ .instance_size = sizeof(TPMPassthruState),
+ .class_init = tpm_passthrough_class_init,
+ .instance_init = tpm_passthrough_inst_init,
+ .instance_finalize = tpm_passthrough_inst_finalize,
+};
+
+static void tpm_passthrough_register(void)
+{
+ type_register_static(&tpm_passthrough_info);
+ tpm_register_driver(&tpm_passthrough_driver);
+}
+
+type_init(tpm_passthrough_register)
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