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-rw-r--r--projects/hsm/hsm.c128
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();