diff options
| -rw-r--r-- | projects/hsm/hsm.c | 128 |
1 files changed, 80 insertions, 48 deletions
diff --git a/projects/hsm/hsm.c b/projects/hsm/hsm.c index f4683b3..3186bc5 100644 --- a/projects/hsm/hsm.c +++ b/projects/hsm/hsm.c @@ -1,7 +1,7 @@ /* - * rpc_server.c - * ------------ - * Remote procedure call server-side private API implementation. + * hsm.c + * ---------------- + * Main module for the HSM project. * * Copyright (c) 2016, NORDUnet A/S All rights reserved. * @@ -33,20 +33,17 @@ */ /* - * 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. + * This is the main RPC server module. At the moment, it has a single + * worker thread to handle RPC requests, while the main thread handles CLI + * activity. The design allows for multiple worker threads to handle + * concurrent RPC requests from multiple clients (muxed through a daemon + * on the host). */ #include <string.h> +/* Rename both CMSIS HAL_OK and libhal HAL_OK to disambiguate */ +#define HAL_OK CMSIS_HAL_OK #include "cmsis_os.h" #include "stm-init.h" @@ -57,46 +54,44 @@ #include "mgmt-cli.h" -/* stm32f4xx_hal_def.h and hal.h both define HAL_OK as an enum value */ -#define HAL_OK HAL_OKAY - +#undef HAL_OK +#define HAL_OK LIBHAL_OK #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. - */ +#undef HAL_OK #ifndef NUM_RPC_TASK -/* An arbitrary number, but we don't expect to have more than 8 concurrent - * RPC requests. +/* Just one RPC task for now. More will require active resource management + * of at least the FPGA cores. */ -#define NUM_RPC_TASK 8 +#define NUM_RPC_TASK 1 #endif #ifndef TASK_STACK_SIZE /* Define an absurdly large task stack, because some pkey operation use a - * lot of stack variables. + * lot of stack variables. This has to go in SDRAM, because it exceeds the + * total RAM on the ARM. */ #define TASK_STACK_SIZE 200*1024 #endif #ifndef MAX_PKT_SIZE -/* Another arbitrary number, more or less driven by the 4096-bit RSA +/* An 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. +/* RPC buffers. For each active RPC, there will be two - input and output. */ typedef struct { size_t len; uint8_t buf[MAX_PKT_SIZE]; } rpc_buffer_t; +#if NUM_RPC_TASK > 1 /* A mutex to arbitrate concurrent UART transmits, from RPC responses. */ osMutexId uart_mutex; @@ -106,6 +101,7 @@ osMutexDef(uart_mutex); */ osMutexId dispatch_mutex; osMutexDef(dispatch_mutex); +#endif /* Semaphore to inform the dispatch thread that there's a new RPC request. */ @@ -114,34 +110,49 @@ osSemaphoreDef(rpc_sem); static volatile uint8_t uart_rx; /* current character received from UART */ static rpc_buffer_t * volatile rbuf; /* current RPC input buffer */ +static volatile int reenable_recv = 1; /* Callback for HAL_UART_Receive_IT(). + * With multiple worker threads, we can't do a blocking receive, because + * that prevents other threads from sending RPC responses (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. + * Even with only one worker thread, context-switching to the CLI thread + * causes HAL_UART_Receive to miss input. */ void HAL_UART2_RxCpltCallback(UART_HandleTypeDef *huart) { int complete; - hal_slip_recv_char(rbuf->buf, &rbuf->len, sizeof(rbuf->buf), &complete); - if (complete) - osSemaphoreRelease(rpc_sem); - HAL_UART_Receive_IT(huart, (uint8_t *)&uart_rx, 1); -} + if (hal_slip_recv_char(rbuf->buf, &rbuf->len, sizeof(rbuf->buf), &complete) != LIBHAL_OK) + Error_Handler(); -hal_error_t hal_serial_send_char(uint8_t c) -{ - return (uart_send_char2(STM_UART_USER, c) == 0) ? HAL_OK : HAL_ERROR_RPC_TRANSPORT; + if (complete) + if (osSemaphoreRelease(rpc_sem) != osOK) + Error_Handler(); + + if (HAL_UART_Receive_IT(huart, (uint8_t *)&uart_rx, 1) != CMSIS_HAL_OK) + /* We may have collided with a transmit. + * Signal the dispatch_thread to try again. + */ + reenable_recv = 1; } hal_error_t hal_serial_recv_char(uint8_t *cp) { /* return the character from HAL_UART_Receive_IT */ *cp = uart_rx; - return HAL_OK; + return LIBHAL_OK; +} + +hal_error_t hal_serial_send_char(uint8_t c) +{ + return (uart_send_char2(STM_UART_USER, c) == 0) ? LIBHAL_OK : HAL_ERROR_RPC_TRANSPORT; } /* Thread entry point for the RPC request handler. */ -static void dispatch_thread(void const *args) +void dispatch_thread(void const *args) { rpc_buffer_t ibuf, obuf; @@ -150,26 +161,46 @@ static void dispatch_thread(void const *args) memset(&obuf, 0, sizeof(obuf)); obuf.len = sizeof(obuf.buf); +#if NUM_RPC_TASK > 1 /* Wait for access to the uart */ osMutexWait(dispatch_mutex, osWaitForever); +#endif + + /* Start receiving, or re-enable after failing in the callback. */ + if (reenable_recv) { + if (HAL_UART_Receive_IT(&huart_user, (uint8_t *)&uart_rx, 1) != CMSIS_HAL_OK) + Error_Handler(); + reenable_recv = 0; + } /* Wait for the complete rpc request */ rbuf = &ibuf; osSemaphoreWait(rpc_sem, osWaitForever); +#if NUM_RPC_TASK > 1 /* Let the next thread handle the next request */ osMutexRelease(dispatch_mutex); /* Let the next thread take the mutex */ osThreadYield(); +#endif /* Process the request */ - hal_rpc_server_dispatch(ibuf.buf, ibuf.len, obuf.buf, &obuf.len); + if (hal_rpc_server_dispatch(ibuf.buf, ibuf.len, obuf.buf, &obuf.len) != LIBHAL_OK) + /* If hal_rpc_server_dispatch failed with an XDR error, it + * probably means the request packet was garbage. In any case, we + * have nothing to transmit. + */ + continue; /* Send the response */ +#if NUM_RPC_TASK > 1 osMutexWait(uart_mutex, osWaitForever); +#endif hal_error_t ret = hal_rpc_sendto(obuf.buf, obuf.len, NULL); +#if NUM_RPC_TASK > 1 osMutexRelease(uart_mutex); - if (ret != HAL_OK) +#endif + if (ret != LIBHAL_OK) Error_Handler(); } } @@ -217,14 +248,18 @@ int main() */ hal_core_iterate(NULL); - uart_mutex = osMutexCreate(osMutex(uart_mutex)); - dispatch_mutex = osMutexCreate(osMutex(dispatch_mutex)); - rpc_sem = osSemaphoreCreate(osSemaphore(rpc_sem), 0); +#if NUM_RPC_TASK > 1 + if ((uart_mutex = osMutexCreate(osMutex(uart_mutex))) == NULL || + (dispatch_mutex = osMutexCreate(osMutex(dispatch_mutex)) == NULL) + Error_Handler(); +#endif + if ((rpc_sem = osSemaphoreCreate(osSemaphore(rpc_sem), 0)) == NULL) + Error_Handler(); - if (hal_rpc_server_init() != HAL_OK) + if (hal_rpc_server_init() != LIBHAL_OK) Error_Handler(); - /* Create the rpc dispatch threads */ + /* Create the rpc dispatch worker threads. */ for (int i = 0; i < NUM_RPC_TASK; ++i) { osThreadDef_t *ot = &thread_def[i]; ot->pthread = dispatch_thread; @@ -237,11 +272,8 @@ int main() Error_Handler(); } - /* Start the non-blocking receive */ - HAL_UART_Receive_IT(&huart_user, (uint8_t *)&uart_rx, 1); - - /* Launch other threads: - * - csprng warm-up thread? + /* Launch other threads (csprng warm-up thread?) + * Wait for FPGA_DONE interrupt. */ return cli_main(); |