| /* SPDX-License-Identifier: BSD-2 */ |
| /* |
| * Copyright (c) 2015 - 2018 Intel Corporation |
| * All rights reserved. |
| */ |
| |
| #include <errno.h> |
| #include <fcntl.h> |
| #include <inttypes.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| #include <poll.h> |
| #include <unistd.h> |
| |
| #include "tss2_tcti.h" |
| #include "tss2_tcti_device.h" |
| #include "tss2_mu.h" |
| #include "tcti-common.h" |
| #include "tcti-device.h" |
| #include "util/io.h" |
| #define LOGMODULE tcti |
| #include "util/log.h" |
| |
| #define TCTI_DEVICE_DEFAULT "/dev/tpm0" |
| /* |
| * This function wraps the "up-cast" of the opaque TCTI context type to the |
| * type for the device TCTI context. The only safe-guard we have to ensure |
| * this operation is possible is the magic number for the device TCTI context. |
| * If passed a NULL context, or the magic number check fails, this function |
| * will return NULL. |
| */ |
| TSS2_TCTI_DEVICE_CONTEXT* |
| tcti_device_context_cast (TSS2_TCTI_CONTEXT *tcti_ctx) |
| { |
| if (tcti_ctx != NULL && TSS2_TCTI_MAGIC (tcti_ctx) == TCTI_DEVICE_MAGIC) { |
| return (TSS2_TCTI_DEVICE_CONTEXT*)tcti_ctx; |
| } |
| return NULL; |
| } |
| /* |
| * This function down-casts the device TCTI context to the common context |
| * defined in the tcti-common module. |
| */ |
| TSS2_TCTI_COMMON_CONTEXT* |
| tcti_device_down_cast (TSS2_TCTI_DEVICE_CONTEXT *tcti_dev) |
| { |
| if (tcti_dev == NULL) { |
| return NULL; |
| } |
| return &tcti_dev->common; |
| } |
| |
| TSS2_RC |
| tcti_device_transmit ( |
| TSS2_TCTI_CONTEXT *tctiContext, |
| size_t command_size, |
| const uint8_t *command_buffer) |
| { |
| TSS2_TCTI_DEVICE_CONTEXT *tcti_dev = tcti_device_context_cast (tctiContext); |
| TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_device_down_cast (tcti_dev); |
| TSS2_RC rc = TSS2_RC_SUCCESS; |
| ssize_t size; |
| |
| if (tcti_dev == NULL) { |
| return TSS2_TCTI_RC_BAD_CONTEXT; |
| } |
| rc = tcti_common_transmit_checks (tcti_common, command_buffer); |
| if (rc != TSS2_RC_SUCCESS) { |
| return rc; |
| } |
| LOGBLOB_DEBUG (command_buffer, |
| command_size, |
| "sending %zu byte command buffer:", |
| command_size); |
| size = write_all (tcti_dev->fd, |
| command_buffer, |
| command_size); |
| if (size < 0) { |
| return TSS2_TCTI_RC_IO_ERROR; |
| } else if ((size_t)size != command_size) { |
| LOG_ERROR ("wrong number of bytes written. Expected %zu, wrote %zd.", |
| command_size, |
| size); |
| return TSS2_TCTI_RC_IO_ERROR; |
| } |
| |
| tcti_common->state = TCTI_STATE_RECEIVE; |
| return TSS2_RC_SUCCESS; |
| } |
| /* |
| * This receive function deviates from the spec a bit. Calling this function |
| * with a NULL 'tctiContext' parameter *should* result in the required size for |
| * the response buffer being returned to the caller. We would typically do this |
| * by reading the response's header and then returning the size to the caller. |
| * We can't do that on account of the TPM2 kernel driver closing any connection |
| * that doesn't read the whole response buffer in one 'read' call. |
| * |
| * Instead, if the caller queries the size, we return 4k just to be on the |
| * safe side. We do *not* however verify that the provided buffer is large |
| * enough to hold the full response (we can't). If the caller provides us with |
| * a buffer less than 4k we'll read as much of the response as we can given |
| * the size of the buffer. If we get enough of the response to read the size |
| * field, we check to see if the buffer was large enough to get the full |
| * response. If the response header claims it's larger than the provided |
| * buffer we print a warning. This allows "expert applications" to |
| * precalculate the required response buffer size for whatever commands they |
| * may send. |
| */ |
| TSS2_RC |
| tcti_device_receive ( |
| TSS2_TCTI_CONTEXT *tctiContext, |
| size_t *response_size, |
| uint8_t *response_buffer, |
| int32_t timeout) |
| { |
| TSS2_TCTI_DEVICE_CONTEXT *tcti_dev = tcti_device_context_cast (tctiContext); |
| TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_device_down_cast (tcti_dev); |
| TSS2_RC rc = TSS2_RC_SUCCESS; |
| ssize_t size = 0; |
| struct pollfd fds; |
| int rc_poll, nfds = 1; |
| #ifdef TCTI_PARTIAL_READ |
| uint8_t header[TPM_HEADER_SIZE]; |
| size_t offset = 2; |
| UINT32 partial_size; |
| #endif |
| |
| if (tcti_dev == NULL) { |
| return TSS2_TCTI_RC_BAD_CONTEXT; |
| } |
| rc = tcti_common_receive_checks (tcti_common, response_size); |
| if (rc != TSS2_RC_SUCCESS) { |
| return rc; |
| } |
| #ifndef TCTI_ASYNC |
| /* For async the valid timeout values are -1 - block forever, |
| * 0 - nonblocking, and any positive value - the actual timeout |
| * value in millisec. |
| * For sync the only valid value is -1 - block forever. |
| */ |
| if (timeout != TSS2_TCTI_TIMEOUT_BLOCK) { |
| LOG_WARNING ("The underlying IPC mechanism does not support " |
| "asynchronous I/O. The 'timeout' parameter must be " |
| "TSS2_TCTI_TIMEOUT_BLOCK"); |
| return TSS2_TCTI_RC_BAD_VALUE; |
| } |
| #endif |
| if (response_buffer == NULL) { |
| #ifndef TCTI_PARTIAL_READ |
| LOG_DEBUG ("Caller queried for size but linux kernel doesn't allow this. " |
| "Returning 4k which is the max size for a response buffer."); |
| *response_size = 4096; |
| return TSS2_RC_SUCCESS; |
| } |
| #else |
| /* Read the header only and get the response size out of it */ |
| LOG_DEBUG("Partial read - reading response size"); |
| fds.fd = tcti_dev->fd; |
| fds.events = POLLIN; |
| |
| rc_poll = poll(&fds, nfds, timeout); |
| if (rc_poll < 0) { |
| LOG_ERROR ("Failed to poll for response from fd %d, got errno %d: %s", |
| tcti_dev->fd, errno, strerror (errno)); |
| return TSS2_TCTI_RC_IO_ERROR; |
| } else if (rc_poll == 0) { |
| LOG_INFO ("Poll timed out on fd %d.", tcti_dev->fd); |
| return TSS2_TCTI_RC_TRY_AGAIN; |
| } else if (fds.revents == POLLIN) { |
| TEMP_RETRY (size, read (tcti_dev->fd, header, TPM_HEADER_SIZE)); |
| if (size < 0 || size != TPM_HEADER_SIZE) { |
| LOG_ERROR ("Failed to get response size fd %d, got errno %d: %s", |
| tcti_dev->fd, errno, strerror (errno)); |
| return TSS2_TCTI_RC_IO_ERROR; |
| } |
| } |
| LOG_DEBUG("Partial read - received header"); |
| rc = Tss2_MU_UINT32_Unmarshal(header, TPM_HEADER_SIZE, |
| &offset, &partial_size); |
| if (rc != TSS2_RC_SUCCESS) { |
| LOG_ERROR ("Failed to unmarshal response size."); |
| return rc; |
| } |
| if (partial_size < TPM_HEADER_SIZE) { |
| LOG_ERROR ("Received %zu bytes, not enough to hold a TPM2 response " |
| "header.", size); |
| return TSS2_TCTI_RC_GENERAL_FAILURE; |
| } |
| |
| LOG_DEBUG("Partial read - received response size %d.", partial_size); |
| tcti_common->partial = true; |
| *response_size = partial_size; |
| memcpy(&tcti_common->header, header, TPM_HEADER_SIZE); |
| return rc; |
| } |
| #endif |
| |
| #ifndef TCTI_PARTIAL_READ |
| if (*response_size < 4096) { |
| #else |
| if (*response_size < TPM_HEADER_SIZE) { |
| #endif |
| LOG_INFO ("Caller provided buffer that *may* not be large enough to " |
| "hold the response buffer."); |
| } |
| |
| /* In case when the whole response is just the 10 bytes header |
| * and we have read it already to get the size, we don't need |
| * to call poll and read again. Just copy what we have read |
| * and return. |
| */ |
| if (tcti_common->partial == true && *response_size == TPM_HEADER_SIZE) { |
| memcpy(response_buffer, &tcti_common->header, TPM_HEADER_SIZE); |
| tcti_common->partial = false; |
| goto out; |
| } |
| |
| /* |
| * The older kernel driver will only return a response buffer in a single |
| * read operation. If we try to read again before sending another command |
| * the kernel will close the file descriptor and we'll get an EOF. |
| * Newer kernels should have partial reads enabled. |
| */ |
| fds.fd = tcti_dev->fd; |
| fds.events = POLLIN; |
| |
| rc_poll = poll(&fds, nfds, timeout); |
| if (rc_poll < 0) { |
| LOG_ERROR ("Failed to poll for response from fd %d, got errno %d: %s", |
| tcti_dev->fd, errno, strerror (errno)); |
| return TSS2_TCTI_RC_IO_ERROR; |
| } else if (rc_poll == 0) { |
| LOG_INFO ("Poll timed out on fd %d.", tcti_dev->fd); |
| return TSS2_TCTI_RC_TRY_AGAIN; |
| } else if (fds.revents == POLLIN) { |
| if (tcti_common->partial == true) { |
| memcpy(response_buffer, &tcti_common->header, TPM_HEADER_SIZE); |
| TEMP_RETRY (size, read (tcti_dev->fd, response_buffer + |
| TPM_HEADER_SIZE, *response_size - TPM_HEADER_SIZE)); |
| } else { |
| TEMP_RETRY (size, read (tcti_dev->fd, response_buffer, |
| *response_size)); |
| } |
| if (size < 0) { |
| LOG_ERROR ("Failed to read response from fd %d, got errno %d: %s", |
| tcti_dev->fd, errno, strerror (errno)); |
| return TSS2_TCTI_RC_IO_ERROR; |
| } |
| } |
| if (size == 0) { |
| LOG_WARNING ("Got EOF instead of response."); |
| rc = TSS2_TCTI_RC_NO_CONNECTION; |
| goto out; |
| } |
| |
| size += tcti_common->partial ? TPM_HEADER_SIZE : 0; |
| LOGBLOB_DEBUG(response_buffer, size, "Response Received"); |
| tcti_common->partial = false; |
| |
| if ((size_t)size < TPM_HEADER_SIZE) { |
| LOG_ERROR ("Received %zu bytes, not enough to hold a TPM2 response " |
| "header.", size); |
| rc = TSS2_TCTI_RC_GENERAL_FAILURE; |
| goto out; |
| } |
| |
| rc = header_unmarshal (response_buffer, &tcti_common->header); |
| if (rc != TSS2_RC_SUCCESS) |
| goto out; |
| |
| LOG_DEBUG("Size from header %u bytes read %zu", tcti_common->header.size, size); |
| |
| if ((size_t)size != tcti_common->header.size) { |
| LOG_WARNING ("TPM2 response size disagrees with number of bytes read " |
| "from fd %d. Header says %u but we read %zu bytes.", |
| tcti_dev->fd, tcti_common->header.size, size); |
| } |
| if (*response_size < tcti_common->header.size) { |
| LOG_WARNING ("TPM2 response size is larger than the provided " |
| "buffer: future use of this TCTI will likely fail."); |
| rc = TSS2_TCTI_RC_GENERAL_FAILURE; |
| } |
| *response_size = size; |
| /* |
| * Executing code beyond this point transitions the state machine to |
| * TRANSMIT. Another call to this function will not be possible until |
| * another command is sent to the TPM. |
| */ |
| out: |
| tcti_common->state = TCTI_STATE_TRANSMIT; |
| |
| return rc; |
| } |
| |
| void |
| tcti_device_finalize ( |
| TSS2_TCTI_CONTEXT *tctiContext) |
| { |
| TSS2_TCTI_DEVICE_CONTEXT *tcti_dev = tcti_device_context_cast (tctiContext); |
| TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_device_down_cast (tcti_dev); |
| |
| if (tcti_dev == NULL) { |
| return; |
| } |
| close (tcti_dev->fd); |
| tcti_common->state = TCTI_STATE_FINAL; |
| } |
| |
| TSS2_RC |
| tcti_device_cancel ( |
| TSS2_TCTI_CONTEXT *tctiContext) |
| { |
| /* Linux driver doesn't expose a mechanism to cancel commands. */ |
| (void)(tctiContext); |
| return TSS2_TCTI_RC_NOT_IMPLEMENTED; |
| } |
| |
| TSS2_RC |
| tcti_device_get_poll_handles ( |
| TSS2_TCTI_CONTEXT *tctiContext, |
| TSS2_TCTI_POLL_HANDLE *handles, |
| size_t *num_handles) |
| { |
| #ifdef TCTI_ASYNC |
| TSS2_TCTI_DEVICE_CONTEXT *tcti_dev = tcti_device_context_cast (tctiContext); |
| |
| if (tcti_dev == NULL) { |
| return TSS2_TCTI_RC_BAD_CONTEXT; |
| } |
| |
| if (handles == NULL || num_handles == NULL) { |
| return TSS2_TCTI_RC_BAD_REFERENCE; |
| } |
| |
| *num_handles = 1; |
| handles->fd = tcti_dev->fd; |
| return TSS2_RC_SUCCESS; |
| #else |
| (void)(tctiContext); |
| (void)(handles); |
| (void)(num_handles); |
| return TSS2_TCTI_RC_NOT_IMPLEMENTED; |
| #endif |
| } |
| |
| TSS2_RC |
| tcti_device_set_locality ( |
| TSS2_TCTI_CONTEXT *tctiContext, |
| uint8_t locality) |
| { |
| /* |
| * Linux driver doesn't expose a mechanism for user space applications |
| * to set locality. |
| */ |
| (void)(tctiContext); |
| (void)(locality); |
| return TSS2_TCTI_RC_NOT_IMPLEMENTED; |
| } |
| |
| TSS2_RC |
| Tss2_Tcti_Device_Init ( |
| TSS2_TCTI_CONTEXT *tctiContext, |
| size_t *size, |
| const char *conf) |
| { |
| TSS2_TCTI_DEVICE_CONTEXT *tcti_dev; |
| TSS2_TCTI_COMMON_CONTEXT *tcti_common; |
| const char *dev_path = conf != NULL ? conf : TCTI_DEVICE_DEFAULT; |
| |
| if (tctiContext == NULL && size == NULL) { |
| return TSS2_TCTI_RC_BAD_VALUE; |
| } else if (tctiContext == NULL) { |
| *size = sizeof (TSS2_TCTI_DEVICE_CONTEXT); |
| return TSS2_RC_SUCCESS; |
| } |
| |
| /* Init TCTI context */ |
| TSS2_TCTI_MAGIC (tctiContext) = TCTI_DEVICE_MAGIC; |
| TSS2_TCTI_VERSION (tctiContext) = TCTI_VERSION; |
| TSS2_TCTI_TRANSMIT (tctiContext) = tcti_device_transmit; |
| TSS2_TCTI_RECEIVE (tctiContext) = tcti_device_receive; |
| TSS2_TCTI_FINALIZE (tctiContext) = tcti_device_finalize; |
| TSS2_TCTI_CANCEL (tctiContext) = tcti_device_cancel; |
| TSS2_TCTI_GET_POLL_HANDLES (tctiContext) = tcti_device_get_poll_handles; |
| TSS2_TCTI_SET_LOCALITY (tctiContext) = tcti_device_set_locality; |
| TSS2_TCTI_MAKE_STICKY (tctiContext) = tcti_make_sticky_not_implemented; |
| tcti_dev = tcti_device_context_cast (tctiContext); |
| tcti_common = tcti_device_down_cast (tcti_dev); |
| tcti_common->state = TCTI_STATE_TRANSMIT; |
| memset (&tcti_common->header, 0, sizeof (tcti_common->header)); |
| tcti_common->locality = 3; |
| |
| tcti_dev->fd = open (dev_path, O_RDWR | O_NONBLOCK); |
| if (tcti_dev->fd < 0) { |
| LOG_ERROR ("Failed to open device file %s: %s", |
| dev_path, strerror (errno)); |
| return TSS2_TCTI_RC_IO_ERROR; |
| } |
| |
| return TSS2_RC_SUCCESS; |
| } |
| |
| const TSS2_TCTI_INFO tss2_tcti_info = { |
| .version = TCTI_VERSION, |
| .name = "tcti-device", |
| .description = "TCTI module for communication with Linux kernel interface.", |
| .config_help = "Path to TPM character device. Default value is: " |
| "TCTI_DEVICE_DEFAULT", |
| .init = Tss2_Tcti_Device_Init, |
| }; |
| |
| const TSS2_TCTI_INFO* |
| Tss2_Tcti_Info (void) |
| { |
| return &tss2_tcti_info; |
| } |