/*
* hsm.c
* ----------------
* Main module for the HSM project.
*
* 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 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"
#include "stm-led.h"
#include "stm-fmc.h"
#include "stm-uart.h"
#include "stm-sdram.h"
#include "mgmt-cli.h"
#undef HAL_OK
#define HAL_OK LIBHAL_OK
#include "hal.h"
#include "hal_internal.h"
#include "slip_internal.h"
#include "xdr_internal.h"
#undef HAL_OK
#ifndef NUM_RPC_TASK
/* Just one RPC task for now. More will require active resource management
* of at least the FPGA cores.
*/
#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. 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
/* An arbitrary number, more or less driven by the 4096-bit RSA
* keygen test.
*/
#define MAX_PKT_SIZE 4096
#endif
/* 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;
osMutexDef(uart_mutex);
/* A mutex so only one dispatch thread can receive requests.
*/
osMutexId dispatch_mutex;
osMutexDef(dispatch_mutex);
#endif
/* Semaphore to inform the dispatch thread that there's a new RPC request.
*/
osSemaphoreId rpc_sem;
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;
if (hal_slip_recv_char(rbuf->buf, &rbuf->len, sizeof(rbuf->buf), &complete) != LIBHAL_OK)
Error_Handler();
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 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.
*/
void dispatch_thread(void const *args)
{
rpc_buffer_t ibuf, obuf;
while (1) {
memset(&ibuf, 0, sizeof(ibuf));
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 */
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);
#endif
if (ret != LIBHAL_OK)
Error_Handler();
}
}
osThreadDef_t thread_def[NUM_RPC_TASK];
/* Allocate memory from SDRAM1. There is only malloc, no free, so we don't
* worry about fragmentation. */
static uint8_t *sdram_malloc(size_t size)
{
/* end of variables declared with __attribute__((section(".sdram1"))) */
extern uint8_t _esdram1 __asm ("_esdram1");
/* end of SDRAM1 section */
extern uint8_t __end_sdram1 __asm ("__end_sdram1");
static uint8_t *sdram_heap = &_esdram1;
uint8_t *p = sdram_heap;
#define pad(n) (((n) + 3) & ~3)
size = pad(size);
if (p + size > &__end_sdram1)
return NULL;
sdram_heap += size;
return p;
}
/* The main thread. This does all the setup, and the worker threads handle
* the rest.
*/
int main()
{
stm_init();
uart_set_default(STM_UART_MGMT);
led_on(LED_GREEN);
/* Prepare FMC interface. */
fmc_init();
sdram_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);
#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() != LIBHAL_OK)
Error_Handler();
/* 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;
ot->tpriority = osPriorityNormal;
ot->stacksize = TASK_STACK_SIZE;
ot->stack_pointer = (uint32_t *)(sdram_malloc(TASK_STACK_SIZE));
if (ot->stack_pointer == NULL)
Error_Handler();
if (osThreadCreate(ot, (void *)i) == NULL)
Error_Handler();
}
/* Launch other threads (csprng warm-up thread?)
* Wait for FPGA_DONE interrupt.
*/
return cli_main();
}
