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Diffstat (limited to 'projects/hsm/hsm.c')
| -rw-r--r-- | projects/hsm/hsm.c | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/projects/hsm/hsm.c b/projects/hsm/hsm.c new file mode 100644 index 0000000..79c567b --- /dev/null +++ b/projects/hsm/hsm.c @@ -0,0 +1,226 @@ +/* + * rpc_server.c + * ------------ + * Remote procedure call server-side private API implementation. + * + * Copyright (c) 2016, NORDUnet A/S 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 name of the NORDUnet 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. + */ + +/* + * This is the main RPC server moddule. It creates a new thread to deal + * with each request, to prevent a long-running request (e.g. RSA keygen) + * from blocking independent requests from other clients. This has a + * number of consequences. We can't do a blocking receive in the main + * thread, because that prevents the dispatch thread from transmitting the + * response (because they both want to lock the UART - see + * stm32f4xx_hal_uart.c). So we have to do a non-blocking receive with a + * callback routine. But we can't create a thread from the callback + * routine, because it's in the context of an ISR, so we raise a semaphore + * for the main thread to create the dispatch thread. + */ + +#include <string.h> + +#include "cmsis_os.h" + +#include "stm-init.h" +#include "stm-led.h" +#include "stm-fmc.h" +#include "stm-uart.h" + +/* stm32f4xx_hal_def.h and hal.h both define HAL_OK as an enum value */ +#define HAL_OK HAL_OKAY + +#include "hal.h" +#include "hal_internal.h" +#include "slip_internal.h" +#include "xdr_internal.h" + +/* RPC buffers. For each active RPC, there will be two - input and output. + */ + +#ifndef NUM_RPC_BUFFER +/* An arbitrary number, but we don't expect to have more than 8 concurrent + * RPC requests. + */ +#define NUM_RPC_BUFFER 16 +#endif + +#ifndef MAX_PKT_SIZE +/* Another arbitrary number, more or less driven by the 4096-bit RSA + * keygen test. + */ +#define MAX_PKT_SIZE 4096 +#endif + +/* The thread entry point takes a single void* argument, so we bundle the + * packet buffer and length arguments together. + */ +typedef struct { + size_t len; + uint8_t buf[MAX_PKT_SIZE]; +} rpc_buffer_t; + +osPoolDef(rpc_buffer_pool, NUM_RPC_BUFFER, rpc_buffer_t); +osPoolId rpc_buffer_pool; + +static rpc_buffer_t *rpc_buffer_alloc(void) +{ + return (rpc_buffer_t *)osPoolCAlloc(rpc_buffer_pool); +} + +/* A mutex to arbitrate concurrent UART transmits, from RPC responses. + */ +osMutexId uart_mutex; +osMutexDef(uart_mutex); + +/* Thread entry point for the RPC request handler. + */ +static void dispatch_thread(void const *args) +{ + rpc_buffer_t *ibuf = (rpc_buffer_t *)args; + rpc_buffer_t *obuf = rpc_buffer_alloc(); + if (obuf == NULL) { + uint8_t buf[8]; + uint8_t * bufptr = &buf[4]; + const uint8_t * const limit = buf + sizeof(buf); + memcpy(buf, ibuf->buf, 4); + hal_xdr_encode_int(&bufptr, limit, HAL_ERROR_ALLOCATION_FAILURE); + osMutexWait(uart_mutex, osWaitForever); + hal_rpc_sendto(ibuf->buf, sizeof(buf), NULL); + osMutexRelease(uart_mutex); + osPoolFree(rpc_buffer_pool, ibuf); + Error_Handler(); + } + /* copy client ID from request to response */ + memcpy(obuf->buf, ibuf->buf, 4); + obuf->len = sizeof(obuf->buf) - 4; + hal_rpc_server_dispatch(ibuf->buf + 4, ibuf->len - 4, obuf->buf + 4, &obuf->len); + osPoolFree(rpc_buffer_pool, ibuf); + osMutexWait(uart_mutex, osWaitForever); + hal_error_t ret = hal_rpc_sendto(obuf->buf, obuf->len + 4, NULL); + osMutexRelease(uart_mutex); + osPoolFree(rpc_buffer_pool, obuf); + if (ret != HAL_OK) + Error_Handler(); +} +osThreadDef(dispatch_thread, osPriorityNormal, DEFAULT_STACK_SIZE); + +/* Semaphore to inform the main thread that there's a new RPC request. + */ +osSemaphoreId rpc_sem; +osSemaphoreDef(rpc_sem); + +static uint8_t c; /* current character received from UART */ +static rpc_buffer_t *ibuf; /* current RPC input buffer */ + +/* Callback for HAL_UART_Receive_IT(). + */ +void HAL_UART2_RxCpltCallback(UART_HandleTypeDef *huart) +{ + int complete; + hal_slip_recv_char(ibuf->buf, &ibuf->len, sizeof(ibuf->buf), &complete); + if (complete) + osSemaphoreRelease(rpc_sem); + + HAL_UART_Receive_IT(huart, &c, 1); +} + +hal_error_t hal_serial_send_char(uint8_t c) +{ + return (uart_send_char(c) == 0) ? HAL_OK : HAL_ERROR_RPC_TRANSPORT; +} + +hal_error_t hal_serial_recv_char(uint8_t *cp) +{ + /* return the character from HAL_UART_Receive_IT */ + *cp = c; + return HAL_OK; +} + +/* The main thread. After the system setup, it waits for the RPC-request + * semaphore from HAL_UART_RxCpltCallback, and spawns a dispatch thread. + */ +int main() +{ + stm_init(); + +#ifdef TARGET_CRYPTECH_DEV_BRIDGE + /* Wait six seconds to not upset the Novena at boot. */ + led_on(LED_BLUE); + for (int i = 0; i < 12; i++) { + osDelay(500); + led_toggle(LED_BLUE); + } + led_off(LED_BLUE); +#endif + led_on(LED_GREEN); + /* Prepare FMC interface. */ + fmc_init(); + + /* Haaaack. probe_cores() calls malloc(), which works from the main + * thread, but not from a spawned thread. It would be better to + * rewrite it to use static memory, but for now, just force it to + * probe early. + */ + hal_core_iterate(NULL); + + rpc_buffer_pool = osPoolCreate(osPool(rpc_buffer_pool)); + uart_mutex = osMutexCreate(osMutex(uart_mutex)); + rpc_sem = osSemaphoreCreate(osSemaphore(rpc_sem), 0); + +#ifdef TARGET_CRYPTECH_ALPHA + /* Launch other threads: + * - admin thread on USART1 + * - csprng warm-up thread? + */ +#endif + + if (hal_rpc_server_init() != HAL_OK) + Error_Handler(); + + ibuf = rpc_buffer_alloc(); + if (ibuf == NULL) + /* Something is badly wrong. */ + Error_Handler(); + + /* Start the non-blocking receive */ + HAL_UART_Receive_IT(&huart_user, &c, 1); + + while (1) { + osSemaphoreWait(rpc_sem, osWaitForever); + if (osThreadCreate(osThread(dispatch_thread), (void *)ibuf) == NULL) + Error_Handler(); + while ((ibuf = rpc_buffer_alloc()) == NULL); + /* XXX There's a potential race condition, where another request + * could write into the old ibuf, or into the null pointer if + * we're out of ibufs. + */ + } +} |