/*
* hsm.c
* ----------------
* Main module for the HSM project.
*
* Copyright (c) 2016-2017, 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;
/* A mail queue (memory pool + message queue) for RPC request messages.
*/
osMailQId ibuf_queue;
osMailQDef(ibuf_queue, NUM_RPC_TASK + 2, rpc_buffer_t);
#if NUM_RPC_TASK > 1
/* A mutex to arbitrate concurrent UART transmits, from RPC responses.
*/
osMutexId uart_mutex;
osMutexDef(uart_mutex);
static inline void uart_lock(void) { osMutexWait(uart_mutex, osWaitForever); }
static inline void uart_unlock(void) { osMutexRelease(uart_mutex); }
#else
static inline void uart_lock(void) { }
static inline void uart_unlock(void) { }
#endif
#if NUM_RPC_TASK > 1
/* A mutex to arbitrate concurrent access to the keystore.
*/
osMutexId ks_mutex;
osMutexDef(ks_mutex);
void hal_ks_lock(void) { osMutexWait(ks_mutex, osWaitForever); }
void hal_ks_unlock(void) { osMutexRelease(ks_mutex); }
#endif
static uint8_t uart_rx[2]; /* current character received from UART */
/* Callback for HAL_UART_Receive_DMA().
* 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.
*/
static void RxCallback(uint8_t c)
{
/* current RPC input buffer */
static rpc_buffer_t *ibuf = NULL;
int complete;
if (ibuf == NULL) {
if ((ibuf = (rpc_buffer_t *)osMailAlloc(ibuf_queue, 0)) == NULL)
/* This could happen if all dispatch threads are busy, and
* there are NUM_RPC_TASK requests already queued. We'd like
* to to send a "server busy" error, but we've just received
* the first byte of the request, so we don't yet have enough
* context to craft a response.
*/
return;
ibuf->len = 0;
}
if (hal_slip_process_char(c, ibuf->buf, &ibuf->len, sizeof(ibuf->buf), &complete) != LIBHAL_OK)
Error_Handler();
if (complete) {
if (osMailPut(ibuf_queue, (void *)ibuf) != osOK)
Error_Handler();
ibuf = NULL;
}
}
void HAL_UART2_RxHalfCpltCallback(UART_HandleTypeDef *huart)
{
RxCallback(uart_rx[0]);
}
void HAL_UART2_RxCpltCallback(UART_HandleTypeDef *huart)
{
RxCallback(uart_rx[1]);
}
void HAL_UART_ErrorCallback(UART_HandleTypeDef *huart)
{
/* I dunno, just trap it for now */
Error_Handler();
}
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 obuf_s, *obuf = &obuf_s, *ibuf;
while (1) {
memset(obuf, 0, sizeof(*obuf));
obuf->len = sizeof(obuf->buf);
/* Wait for a complete RPC request */
osEvent evt = osMailGet(ibuf_queue, osWaitForever);
if (evt.status != osEventMail)
continue;
ibuf = (rpc_buffer_t *)evt.value.p;
/* Process the request */
hal_error_t ret = hal_rpc_server_dispatch(ibuf->buf, ibuf->len, obuf->buf, &obuf->len);
osMailFree(ibuf_queue, (void *)ibuf);
if (ret != 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 */
uart_lock();
ret = hal_rpc_sendto(obuf->buf, obuf->len, NULL);
uart_unlock();
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;
}
/* Implement static memory allocation for libhal over sdram_malloc().
* Once again, there's only alloc, not free. */
void *hal_allocate_static_memory(const size_t size)
{
return sdram_malloc(size);
}
#if NUM_RPC_TASK > 1
/* Critical section start/end, currently used just for hal_core_alloc/_free.
*/
void hal_critical_section_start(void)
{
__disable_irq();
}
void hal_critical_section_end(void)
{
__enable_irq();
}
#endif
/* 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();
if ((ibuf_queue = osMailCreate(osMailQ(ibuf_queue), NULL)) == NULL)
Error_Handler();
#if NUM_RPC_TASK > 1
if ((uart_mutex = osMutexCreate(osMutex(uart_mutex))) == NULL)
Error_Handler();
if ((ks_mutex = osMutexCreate(osMutex(ks_mutex))) == NULL)
Error_Handler();
#endif
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();
}
/* Start the UART receiver. */
if (HAL_UART_Receive_DMA(&huart_user, uart_rx, 2) != CMSIS_HAL_OK)
Error_Handler();
/* Launch other threads (csprng warm-up thread?)
* Wait for FPGA_DONE interrupt.
*/
return cli_main();
}
