cleaning up uart_posix.c

[proxmark3-svn] / client / comms.c

//-----------------------------------------------------------------------------
// Copyright (C) 2009 Michael Gernoth <michael at gernoth.net>
// Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// Code for communicating with the proxmark3 hardware.
//-----------------------------------------------------------------------------

#include "comms.h"

#include <stdio.h>
#include <stddef.h>
#include <string.h>
#include <pthread.h>
#include <inttypes.h>

#if defined(__linux__) && !defined(NO_UNLINK)
#include <unistd.h>     // for unlink()
#endif
#include "uart.h"
#include "ui.h"
#include "common.h"
#include "util_darwin.h"
#include "util_posix.h"


// Serial port that we are communicating with the PM3 on.
static serial_port sp = NULL;
static char *serial_port_name = NULL;

// If TRUE, then there is no active connection to the PM3, and we will drop commands sent.
static bool offline;

typedef struct {
        bool run; // If TRUE, continue running the uart_communication thread
} communication_arg_t;

static communication_arg_t conn;
static pthread_t USB_communication_thread;

// Transmit buffer.
static UsbCommand txBuffer;
static bool txBuffer_pending = false;
static pthread_mutex_t txBufferMutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t txBufferSig = PTHREAD_COND_INITIALIZER;

// Used by UsbReceiveCommand as a ring buffer for messages that are yet to be
// processed by a command handler (WaitForResponse{,Timeout})
#define CMD_BUFFER_SIZE 50
static UsbCommand rxBuffer[CMD_BUFFER_SIZE];

// Points to the next empty position to write to
static int cmd_head = 0;

// Points to the position of the last unread command
static int cmd_tail = 0;

// to lock rxBuffer operations from different threads
static pthread_mutex_t rxBufferMutex = PTHREAD_MUTEX_INITIALIZER;

// These wrappers are required because it is not possible to access a static
// global variable outside of the context of a single file.

void SetOffline(bool new_offline) {
        offline = new_offline;
}

bool IsOffline() {
        return offline;
}

void SendCommand(UsbCommand *c) {
        #ifdef COMMS_DEBUG
        printf("Sending %04x cmd\n", c->cmd);
        #endif

        if (offline) {
                PrintAndLog("Sending bytes to proxmark failed - offline");
                return;
        }

        pthread_mutex_lock(&txBufferMutex);
        /**
        This causes hangups at times, when the pm3 unit is unresponsive or disconnected. The main console thread is alive,
        but comm thread just spins here. Not good.../holiman
        **/
        while (txBuffer_pending) {
                pthread_cond_wait(&txBufferSig, &txBufferMutex); // wait for communication thread to complete sending a previous commmand
        }

        txBuffer = *c;
        txBuffer_pending = true;
        pthread_cond_signal(&txBufferSig); // tell communication thread that a new command can be send

        pthread_mutex_unlock(&txBufferMutex);

}


/**
 * @brief This method should be called when sending a new command to the pm3. In case any old
 *  responses from previous commands are stored in the buffer, a call to this method should clear them.
 *  A better method could have been to have explicit command-ACKS, so we can know which ACK goes to which
 *  operation. Right now we'll just have to live with this.
 */
void clearCommandBuffer()
{
        //This is a very simple operation
        pthread_mutex_lock(&rxBufferMutex);
        cmd_tail = cmd_head;
        pthread_mutex_unlock(&rxBufferMutex);
}

/**
 * @brief storeCommand stores a USB command in a circular buffer
 * @param UC
 */
static void storeCommand(UsbCommand *command)
{
        pthread_mutex_lock(&rxBufferMutex);
        if( (cmd_head+1) % CMD_BUFFER_SIZE == cmd_tail)
        {
                // If these two are equal, we're about to overwrite in the
                // circular buffer.
                PrintAndLog("WARNING: Command buffer about to overwrite command! This needs to be fixed!");
        }

        // Store the command at the 'head' location
        UsbCommand* destination = &rxBuffer[cmd_head];
        memcpy(destination, command, sizeof(UsbCommand));

        cmd_head = (cmd_head +1) % CMD_BUFFER_SIZE; //increment head and wrap
        pthread_mutex_unlock(&rxBufferMutex);
}


/**
 * @brief getCommand gets a command from an internal circular buffer.
 * @param response location to write command
 * @return 1 if response was returned, 0 if nothing has been received
 */
static int getCommand(UsbCommand* response)
{
        pthread_mutex_lock(&rxBufferMutex);
        //If head == tail, there's nothing to read, or if we just got initialized
        if (cmd_head == cmd_tail){
                pthread_mutex_unlock(&rxBufferMutex);
                return 0;
        }

        //Pick out the next unread command
        UsbCommand* last_unread = &rxBuffer[cmd_tail];
        memcpy(response, last_unread, sizeof(UsbCommand));
        //Increment tail - this is a circular buffer, so modulo buffer size
        cmd_tail = (cmd_tail + 1) % CMD_BUFFER_SIZE;

        pthread_mutex_unlock(&rxBufferMutex);
        return 1;
}


//----------------------------------------------------------------------------------
// Entry point into our code: called whenever we received a packet over USB.
// Handle debug commands directly, store all other commands in circular buffer.
//----------------------------------------------------------------------------------
static void UsbCommandReceived(UsbCommand *UC)
{
        switch(UC->cmd) {
                // First check if we are handling a debug message
                case CMD_DEBUG_PRINT_STRING: {
                        char s[USB_CMD_DATA_SIZE+1];
                        memset(s, 0x00, sizeof(s));
                        size_t len = MIN(UC->arg[0],USB_CMD_DATA_SIZE);
                        memcpy(s,UC->d.asBytes,len);
                        PrintAndLog("#db# %s", s);
                        return;
                } break;

                case CMD_DEBUG_PRINT_INTEGERS: {
                        PrintAndLog("#db# %08x, %08x, %08x       \r\n", UC->arg[0], UC->arg[1], UC->arg[2]);
                        return;
                } break;

                default:
                        storeCommand(UC);
                        break;
        }

}


static bool receive_from_serial(serial_port sp, uint8_t *rx_buf, size_t len, size_t *received_len) {
        size_t bytes_read = 0;
        *received_len = 0;
        // we eventually need to call uart_receive several times if it times out in the middle of a transfer
        while (uart_receive(sp, rx_buf + *received_len, len - *received_len, &bytes_read) && bytes_read && *received_len < len) {
                #ifdef COMMS_DEBUG
                if (bytes_read != len - *received_len) {
                        printf("uart_receive() returned true but not enough bytes could be received. received: %d, wanted to receive: %d, already received before: %d\n",
                                bytes_read, len - *received_len, *received_len);
                }
                #endif
                *received_len += bytes_read;
                bytes_read = 0;
        }
        return (*received_len == len);
}


static void
#ifdef __has_attribute
#if __has_attribute(force_align_arg_pointer)
__attribute__((force_align_arg_pointer))
#endif
#endif
*uart_communication(void *targ) {
        communication_arg_t *conn = (communication_arg_t*)targ;
        uint8_t rx[sizeof(UsbCommand)];
        size_t rxlen = 0;
        uint8_t *prx = rx;
        UsbCommand *command = (UsbCommand*)rx;
        UsbResponse *response = (UsbResponse*)rx;

#if defined(__MACH__) && defined(__APPLE__)
        disableAppNap("Proxmark3 polling UART");
#endif

        while (conn->run) {
                bool ACK_received = false;
                prx = rx;
                size_t bytes_to_read = offsetof(UsbResponse, d);  // the fixed part of a new style UsbResponse. Otherwise this will be cmd and arg[0] (64 bit each)
                if (receive_from_serial(sp, prx, bytes_to_read, &rxlen)) {
                        prx += rxlen;
                        if (response->cmd & CMD_VARIABLE_SIZE_FLAG) { // new style response with variable size
                                // PrintAndLog("received new style response %04" PRIx16 ", datalen = %d, arg[0] = %08" PRIx32 ", arg[1] = %08" PRIx32 ", arg[2] = %08" PRIx32 "\n",
                                        // response->cmd, response->datalen, response->arg[0], response->arg[1], response->arg[2]);
                                bytes_to_read = response->datalen;
                                if (receive_from_serial(sp, prx, bytes_to_read, &rxlen)) {
                                        UsbCommand resp;
                                        resp.cmd = response->cmd & ~CMD_VARIABLE_SIZE_FLAG;  // remove the flag
                                        resp.arg[0] = response->arg[0];
                                        resp.arg[1] = response->arg[1];
                                        resp.arg[2] = response->arg[2];
                                        memcpy(&resp.d.asBytes, &response->d.asBytes, response->datalen);
                                        UsbCommandReceived(&resp);
                                        if (resp.cmd == CMD_ACK) {
                                                ACK_received = true;
                                        }
                                }
                        } else { // old style response uses same data structure as commands. Fixed size.
                                // PrintAndLog("received old style response %016" PRIx64 ", arg[0] = %016" PRIx64 "\n", command->cmd, command->arg[0]);
                                bytes_to_read = sizeof(UsbCommand) - bytes_to_read;
                                if (receive_from_serial(sp, prx, bytes_to_read, &rxlen)) {
                                        UsbCommandReceived(command);
                                        if (command->cmd == CMD_ACK) {
                                                ACK_received = true;
                                        }
                                }
                        }
                }

                pthread_mutex_lock(&txBufferMutex);
                // if we received an ACK the PM has done its job and waits for another command.
                // We therefore can wait here as well until a new command is to be transmitted.
                // The advantage is that the next command will be transmitted immediately without the need to wait for a receive timeout
                if (ACK_received) {
                        while (!txBuffer_pending) {
                                pthread_cond_wait(&txBufferSig, &txBufferMutex);
                        }
                }
                if (txBuffer_pending) {
                        if (!uart_send(sp, (uint8_t*) &txBuffer, sizeof(UsbCommand))) {
                                PrintAndLog("Sending bytes to proxmark failed");
                        }
                        txBuffer_pending = false;
                }
                pthread_cond_signal(&txBufferSig); // tell main thread that txBuffer is empty
                pthread_mutex_unlock(&txBufferMutex);
        }

#if defined(__MACH__) && defined(__APPLE__)
        enableAppNap();
#endif

        pthread_exit(NULL);
        return NULL;
}


/**
 * Data transfer from Proxmark to client. This method times out after
 * ms_timeout milliseconds.
 * @brief GetFromBigBuf
 * @param dest Destination address for transfer
 * @param bytes number of bytes to be transferred
 * @param start_index offset into Proxmark3 BigBuf[]
 * @param response struct to copy last command (CMD_ACK) into
 * @param ms_timeout timeout in milliseconds
 * @param show_warning display message after 2 seconds
 * @return true if command was returned, otherwise false
 */
bool GetFromBigBuf(uint8_t *dest, int bytes, int start_index, UsbCommand *response, size_t ms_timeout, bool show_warning)
{
        UsbCommand c = {CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K, {start_index, bytes, 0}};
        SendCommand(&c);

        uint64_t start_time = msclock();

        UsbCommand resp;
        if (response == NULL) {
                response = &resp;
        }

        int bytes_completed = 0;
        while(true) {
                if (getCommand(response)) {
                        if (response->cmd == CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K) {
                                int copy_bytes = MIN(bytes - bytes_completed, response->arg[1]);
                                memcpy(dest + response->arg[0], response->d.asBytes, copy_bytes);
                                bytes_completed += copy_bytes;
                        } else if (response->cmd == CMD_ACK) {
                                return true;
                        }
                }

                if (msclock() - start_time > ms_timeout) {
                        break;
                }

                if (msclock() - start_time > 2000 && show_warning) {
                        PrintAndLog("Waiting for a response from the proxmark...");
                        PrintAndLog("You can cancel this operation by pressing the pm3 button");
                        show_warning = false;
                }
        }

        return false;
}


bool GetFromFpgaRAM(uint8_t *dest, int bytes)
{
        UsbCommand c = {CMD_HF_PLOT, {0, 0, 0}};
        SendCommand(&c);

        uint64_t start_time = msclock();

        UsbCommand response;

        int bytes_completed = 0;
        bool show_warning = true;
        while(true) {
                if (getCommand(&response)) {
                        if (response.cmd == CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K) {
                                int copy_bytes = MIN(bytes - bytes_completed, response.arg[1]);
                                memcpy(dest + response.arg[0], response.d.asBytes, copy_bytes);
                                bytes_completed += copy_bytes;
                        } else if (response.cmd == CMD_ACK) {
                                return true;
                        }
                }

                if (msclock() - start_time > 2000 && show_warning) {
                        PrintAndLog("Waiting for a response from the proxmark...");
                        PrintAndLog("You can cancel this operation by pressing the pm3 button");
                        show_warning = false;
                }
        }

        return false;
}


bool OpenProxmark(void *port, bool wait_for_port, int timeout) {
        char *portname = (char *)port;
        if (!wait_for_port) {
                sp = uart_open(portname);
        } else {
                printf("Waiting for Proxmark to appear on %s ", portname);
                fflush(stdout);
                int openCount = 0;
                do {
                        sp = uart_open(portname);
                        msleep(1000);
                        printf(".");
                        fflush(stdout);
                } while(++openCount < timeout && (sp == INVALID_SERIAL_PORT || sp == CLAIMED_SERIAL_PORT));
                printf("\n");
        }

        // check result of uart opening
        if (sp == INVALID_SERIAL_PORT) {
                printf("ERROR: invalid serial port\n");
                sp = NULL;
                serial_port_name = NULL;
                return false;
        } else if (sp == CLAIMED_SERIAL_PORT) {
                printf("ERROR: serial port is claimed by another process\n");
                sp = NULL;
                serial_port_name = NULL;
                return false;
        } else {
                // start the USB communication thread
                serial_port_name = portname;
                conn.run = true;
                pthread_create(&USB_communication_thread, NULL, &uart_communication, &conn);
                return true;
        }
}


void CloseProxmark(void) {
        conn.run = false;

#ifdef __BIONIC__
        // In Android O and later, if an invalid pthread_t is passed to pthread_join, it calls fatal().
        // https://github.com/aosp-mirror/platform_bionic/blob/ed16b344e75f422fb36fbfd91fb30de339475880/libc/bionic/pthread_internal.cpp#L116-L128
        //
        // In Bionic libc, pthread_t is an integer.

        if (USB_communication_thread != 0) {
                pthread_join(USB_communication_thread, NULL);
        }
#else
        // pthread_t is a struct on other libc, treat as an opaque memory reference
        pthread_join(USB_communication_thread, NULL);
#endif

        if (sp) {
                uart_close(sp);
        }

#if defined(__linux__) && !defined(NO_UNLINK)
        // Fix for linux, it seems that it is extremely slow to release the serial port file descriptor /dev/*
        //
        // This may be disabled at compile-time with -DNO_UNLINK (used for a JNI-based serial port on Android).
        if (serial_port_name) {
                unlink(serial_port_name);
        }
#endif

        // Clean up our state
        sp = NULL;
        serial_port_name = NULL;
#ifdef __BIONIC__
        memset(&USB_communication_thread, 0, sizeof(pthread_t));
#endif
}


/**
 * Waits for a certain response type. This method waits for a maximum of
 * ms_timeout milliseconds for a specified response command.
 *@brief WaitForResponseTimeout
 * @param cmd command to wait for, or CMD_UNKNOWN to take any command.
 * @param response struct to copy received command into.
 * @param ms_timeout
 * @param show_warning display message after 2 seconds
 * @return true if command was returned, otherwise false
 */
bool WaitForResponseTimeoutW(uint32_t cmd, UsbCommand* response, size_t ms_timeout, bool show_warning) {

        UsbCommand resp;

        #ifdef COMMS_DEBUG
        printf("Waiting for %04x cmd\n", cmd);
        #endif

        if (response == NULL) {
                response = &resp;
        }

        uint64_t start_time = msclock();

        // Wait until the command is received
        while (true) {
                while (getCommand(response)) {
                        if (cmd == CMD_UNKNOWN || response->cmd == cmd) {
                                return true;
                        }
                }

                if (msclock() - start_time > ms_timeout) {
                        break;
                }

                if (msclock() - start_time > 2000 && show_warning) {
                        // 2 seconds elapsed (but this doesn't mean the timeout was exceeded)
                        PrintAndLog("Waiting for a response from the proxmark...");
                        PrintAndLog("You can cancel this operation by pressing the pm3 button");
                        show_warning = false;
                }
        }
        return false;
}


bool WaitForResponseTimeout(uint32_t cmd, UsbCommand* response, size_t ms_timeout) {
        return WaitForResponseTimeoutW(cmd, response, ms_timeout, true);
}

bool WaitForResponse(uint32_t cmd, UsbCommand* response) {
        return WaitForResponseTimeoutW(cmd, response, -1, true);
}