| /********************************************************************************/ |
| /* */ |
| /* Skiboot Transmit and Receive Utilities */ |
| /* */ |
| /* (c) Copyright IBM Corporation 2020. */ |
| /* */ |
| /* All rights reserved. */ |
| /* */ |
| /* Redistribution and use in source and binary forms, with or without */ |
| /* modification, are permitted provided that the following conditions are */ |
| /* met: */ |
| /* */ |
| /* Redistributions of source code must retain the above copyright notice, */ |
| /* this list of conditions and the following disclaimer. */ |
| /* */ |
| /* Redistributions in binary form must reproduce the above copyright */ |
| /* notice, this list of conditions and the following disclaimer in the */ |
| /* documentation and/or other materials provided with the distribution. */ |
| /* */ |
| /* Neither the names of the IBM Corporation nor the names of its */ |
| /* contributors may be used to endorse or promote products derived from */ |
| /* this software without specific prior written permission. */ |
| /* */ |
| /* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS */ |
| /* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT */ |
| /* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR */ |
| /* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT */ |
| /* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, */ |
| /* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT */ |
| /* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, */ |
| /* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY */ |
| /* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT */ |
| /* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE */ |
| /* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ |
| /********************************************************************************/ |
| |
| #include <string.h> |
| |
| #include <ibmtss/tssresponsecode.h> |
| #include <ibmtss/Implementation.h> |
| #include <ibmtss/tsserror.h> |
| #include <ibmtss/tssprint.h> |
| #include <tssproperties.h> |
| |
| #include <tssdev.h> |
| #include <tpm_chip.h> |
| |
| /* global configuration */ |
| |
| extern int tssVerbose; |
| extern int tssVverbose; |
| |
| /* |
| * TSS_Dev_Transmit() transmits the command and receives the response in |
| * skiboot. |
| * Can return device transmit and receive packet errors, but normally returns |
| * the TPM response code. |
| */ |
| TPM_RC TSS_Dev_Transmit(TSS_CONTEXT *tssContext, |
| uint8_t *responseBuffer, uint32_t *length, |
| const uint8_t *commandBuffer, uint32_t written, |
| const char *message) |
| { |
| TPM_RC rc = 0; |
| size_t responseSize; |
| |
| /* skiboot driver's transmit function expects a size_t value as buffer |
| * length instead of uint32_t used in this function header, so this |
| * variable exists just for type compatibility. |
| */ |
| size_t buffer_length; |
| |
| if (message != NULL) { |
| if (tssVverbose) printf("TSS_Skiboot_Transmit: %s\n", message); |
| } |
| if ((rc == 0) && tssVverbose) { |
| TSS_PrintAll("TSS_Skiboot_Transmit: Command ", |
| commandBuffer, written); |
| } |
| |
| /* we don't need to open a device as it is done in user space but we |
| * need to be sure a device and the driver are available for use. |
| */ |
| if (rc == 0) { |
| if (tssContext->tssFirstTransmit) { |
| tssContext->tpm_device = tpm_get_device(); |
| if (tssContext->tpm_device == NULL) { |
| if (tssVerbose) |
| printf("TSS_Skiboot_Transmit: TPM device not set\n"); |
| rc = TSS_RC_NO_CONNECTION; |
| } |
| if (rc == 0) { |
| tssContext->tpm_driver = tpm_get_driver(); |
| if (tssContext->tpm_driver == NULL) { |
| if (tssVerbose) |
| printf("TSS_Skiboot_Transmit: TPM driver not set\n"); |
| rc = TSS_RC_NO_CONNECTION; |
| } |
| } |
| } |
| } |
| |
| if (rc == 0 ) { |
| tssContext->tssFirstTransmit = FALSE; |
| } |
| |
| /* |
| * Let's issue compilation issue if eventually MAX_COMMAND_SIZE becomes |
| * potentially greater than MAX_RESPONSE_SIZE |
| */ |
| #if MAX_COMMAND_SIZE > MAX_RESPONSE_SIZE |
| #error "MAX_COMMAND_SIZE cannot be greater than MAX_RESPONSE_SIZE. Potential overflow on the buffer for Command and Response" |
| #endif |
| if (rc == 0) { |
| if (written > MAX_RESPONSE_SIZE) { |
| if (tssVerbose) |
| printf("TSS_Skiboot_Transmit: Response Overflow. TPM wrote %u bytes, Max response size is %u ", |
| written, MAX_RESPONSE_SIZE); |
| rc = TSS_RC_BAD_CONNECTION; |
| } |
| } |
| |
| /* |
| * the buffer used to send the command will be overwritten and store the |
| * response data after TPM execution. So here we copy the contents of |
| * commandBuffer to responseBuffer, using the latter to perform the |
| * operation and storing the response and keeping the former safe. |
| */ |
| if (rc == 0) { |
| /* |
| * skiboot driver checks for overflow, so we need to share the |
| * max response size to length. In the response length will |
| * contain the length of the response buffer. |
| */ |
| buffer_length = MAX_RESPONSE_SIZE; |
| |
| memcpy(responseBuffer, commandBuffer, written); |
| rc = tssContext->tpm_driver->transmit(tssContext->tpm_device, |
| responseBuffer, written, &buffer_length); |
| /* now that we have buffer length set we save it to length so it |
| * can be used by the callers |
| */ |
| *length = buffer_length; |
| |
| if (rc != 0) { |
| if (tssVerbose) |
| printf("TSS_Skiboot_Transmit: receive error %u\n", rc); |
| rc = TSS_RC_BAD_CONNECTION; |
| } |
| } |
| |
| if (rc == 0) { |
| if (tssVverbose) |
| TSS_PrintAll("TSS_Skiboot_Transmit: Response", responseBuffer, *length); |
| |
| /* verify that there is at least a tag, responseSize, and responseCode */ |
| if (*length < (sizeof(TPM_ST) + (2 * sizeof(uint32_t)))) { |
| if (tssVerbose) |
| printf("TSS_Skiboot_Transmit: received %u bytes < header\n", *length); |
| rc = TSS_RC_MALFORMED_RESPONSE; |
| } |
| } |
| |
| /* |
| * length and the response size in the response body should match. Check |
| * it here. |
| */ |
| if (rc == 0) { |
| responseSize = ntohl(*(uint32_t *)(responseBuffer + sizeof(TPM_ST))); |
| if (responseSize != *length) { |
| if (tssVerbose) |
| printf("TSS_Skiboot_Transmit: Bytes read (%u) and Buffer responseSize field (%lu) don't match\n", |
| *length, responseSize); |
| rc = TSS_RC_MALFORMED_RESPONSE; |
| } |
| } |
| |
| /* |
| * Now we need to get the actual return code from the response buffer |
| * and deliver it to the upper layers |
| */ |
| if (rc == 0) |
| rc = ntohl(*(uint32_t *)(responseBuffer + sizeof(TPM_ST) + sizeof(uint32_t))); |
| |
| if (tssVverbose) |
| printf("TSS_Skiboot_Transmit: Response Code: %08x", rc); |
| |
| return rc; |
| } |
| |
| TPM_RC TSS_Dev_Close(TSS_CONTEXT *tssContext) |
| { |
| tssContext = tssContext; |
| return 0; |
| } |