git.zerfleddert.de Git - proxmark3-svn/blob - client/comms.c

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) 2009 Michael Gernoth <michael at gernoth.net>
   3 // Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
   4 //
   5 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   6 // at your option, any later version. See the LICENSE.txt file for the text of
   7 // the license.
   8 //-----------------------------------------------------------------------------
   9 // Code for communicating with the proxmark3 hardware.
  10 //-----------------------------------------------------------------------------
  11
  12 #include <pthread.h>
  13
  14 #include "comms.h"
  15 #include "uart.h"
  16 #include "ui.h"
  17 #include "common.h"
  18 #include "data.h"
  19 #include "util_posix.h"
  20
  21 // Declare globals.
  22
  23 // Serial port that we are communicating with the PM3 on.
  24 serial_port sp;
  25
  26 // If TRUE, then there is no active connection to the PM3, and we will drop commands sent.
  27 static bool offline;
  28
  29 // Transmit buffer.
  30 // TODO: Use locks and execute this on the main thread, rather than the receiver
  31 // thread.  Running on the main thread means we need to be careful in the
  32 // flasher, as it means SendCommand is no longer async, and can't be used as a
  33 // buffer for a pending command when the connection is re-established.
  34 static UsbCommand txcmd;
  35 volatile static bool txcmd_pending = false;
  36
  37 // Used by UsbReceiveCommand as a ring buffer for messages that are yet to be
  38 // processed by a command handler (WaitForResponse{,Timeout})
  39 static UsbCommand cmdBuffer[CMD_BUFFER_SIZE];
  40
  41 // Points to the next empty position to write to
  42 static int cmd_head = 0;
  43
  44 // Points to the position of the last unread command
  45 static int cmd_tail = 0;
  46
  47 // to lock cmdBuffer operations from different threads
  48 static pthread_mutex_t cmdBufferMutex = PTHREAD_MUTEX_INITIALIZER;
  49
  50 // These wrappers are required because it is not possible to access a static
  51 // global variable outside of the context of a single file.
  52
  53 void SetOffline(bool new_offline) {
  54         offline = new_offline;
  55 }
  56
  57 bool IsOffline() {
  58         return offline;
  59 }
  60
  61 void SendCommand(UsbCommand *c) {
  62         #ifdef COMMS_DEBUG
  63         printf("Sending %04x cmd\n", c->cmd);
  64         #endif
  65
  66         if (offline) {
  67                 PrintAndLog("Sending bytes to proxmark failed - offline");
  68                 return;
  69     }
  70         /**
  71         The while-loop below causes hangups at times, when the pm3 unit is unresponsive
  72         or disconnected. The main console thread is alive, but comm thread just spins here.
  73         Not good.../holiman
  74         **/
  75         while(txcmd_pending);
  76         txcmd = *c;
  77         txcmd_pending = true;
  78 }
  79
  80
  81 /**
  82  * @brief This method should be called when sending a new command to the pm3. In case any old
  83  *  responses from previous commands are stored in the buffer, a call to this method should clear them.
  84  *  A better method could have been to have explicit command-ACKS, so we can know which ACK goes to which
  85  *  operation. Right now we'll just have to live with this.
  86  */
  87 void clearCommandBuffer()
  88 {
  89         //This is a very simple operation
  90         pthread_mutex_lock(&cmdBufferMutex);
  91         cmd_tail = cmd_head;
  92         pthread_mutex_unlock(&cmdBufferMutex);
  93 }
  94
  95 /**
  96  * @brief storeCommand stores a USB command in a circular buffer
  97  * @param UC
  98  */
  99 void storeCommand(UsbCommand *command)
 100 {
 101         pthread_mutex_lock(&cmdBufferMutex);
 102         if( (cmd_head+1) % CMD_BUFFER_SIZE == cmd_tail)
 103         {
 104                 // If these two are equal, we're about to overwrite in the
 105                 // circular buffer.
 106                 PrintAndLog("WARNING: Command buffer about to overwrite command! This needs to be fixed!");
 107         }
 108
 109         // Store the command at the 'head' location
 110         UsbCommand* destination = &cmdBuffer[cmd_head];
 111         memcpy(destination, command, sizeof(UsbCommand));
 112
 113         cmd_head = (cmd_head +1) % CMD_BUFFER_SIZE; //increment head and wrap
 114         pthread_mutex_unlock(&cmdBufferMutex);
 115 }
 116
 117
 118 /**
 119  * @brief getCommand gets a command from an internal circular buffer.
 120  * @param response location to write command
 121  * @return 1 if response was returned, 0 if nothing has been received
 122  */
 123 int getCommand(UsbCommand* response)
 124 {
 125         pthread_mutex_lock(&cmdBufferMutex);
 126         //If head == tail, there's nothing to read, or if we just got initialized
 127         if (cmd_head == cmd_tail){
 128                 pthread_mutex_unlock(&cmdBufferMutex);
 129                 return 0;
 130         }
 131
 132         //Pick out the next unread command
 133         UsbCommand* last_unread = &cmdBuffer[cmd_tail];
 134         memcpy(response, last_unread, sizeof(UsbCommand));
 135         //Increment tail - this is a circular buffer, so modulo buffer size
 136         cmd_tail = (cmd_tail + 1) % CMD_BUFFER_SIZE;
 137
 138         pthread_mutex_unlock(&cmdBufferMutex);
 139         return 1;
 140 }
 141
 142
 143 //-----------------------------------------------------------------------------
 144 // Entry point into our code: called whenever we received a packet over USB
 145 // that we weren't necessarily expecting, for example a debug print.
 146 //-----------------------------------------------------------------------------
 147 void UsbCommandReceived(UsbCommand *UC)
 148 {
 149         switch(UC->cmd) {
 150                 // First check if we are handling a debug message
 151                 case CMD_DEBUG_PRINT_STRING: {
 152                         char s[USB_CMD_DATA_SIZE+1];
 153                         memset(s, 0x00, sizeof(s));
 154                         size_t len = MIN(UC->arg[0],USB_CMD_DATA_SIZE);
 155                         memcpy(s,UC->d.asBytes,len);
 156                         PrintAndLog("#db# %s", s);
 157                         return;
 158                 } break;
 159
 160                 case CMD_DEBUG_PRINT_INTEGERS: {
 161                         PrintAndLog("#db# %08x, %08x, %08x       \r\n", UC->arg[0], UC->arg[1], UC->arg[2]);
 162                         return;
 163                 } break;
 164
 165                 case CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K: {
 166                         // FIXME: This does unsanitised copies into memory when we don't know
 167                         // the size of the buffer.
 168                         memcpy(sample_buf+(UC->arg[0]),UC->d.asBytes,UC->arg[1]);
 169                         return;
 170                 } break;
 171
 172                 default:
 173                         storeCommand(UC);
 174                         break;
 175         }
 176
 177 }
 178
 179
 180 void
 181 #ifdef __has_attribute
 182 #if __has_attribute(force_align_arg_pointer)
 183 __attribute__((force_align_arg_pointer))
 184 #endif
 185 #endif
 186 *uart_receiver(void *targ) {
 187         receiver_arg *arg = (receiver_arg*)targ;
 188         size_t rxlen;
 189         uint8_t rx[sizeof(UsbCommand)];
 190         uint8_t *prx = rx;
 191
 192         while (arg->run) {
 193                 rxlen = 0;
 194                 if (uart_receive(sp, prx, sizeof(UsbCommand) - (prx-rx), &rxlen) && rxlen) {
 195                         prx += rxlen;
 196                         if (prx-rx < sizeof(UsbCommand)) {
 197                                 continue;
 198                         }
 199                         UsbCommandReceived((UsbCommand*)rx);
 200                 }
 201                 prx = rx;
 202
 203                 if(txcmd_pending) {
 204                         if (!uart_send(sp, (uint8_t*) &txcmd, sizeof(UsbCommand))) {
 205                                 PrintAndLog("Sending bytes to proxmark failed");
 206                         }
 207                         txcmd_pending = false;
 208                 }
 209         }
 210
 211         pthread_exit(NULL);
 212         return NULL;
 213 }
 214
 215
 216 /**
 217  * Waits for a certain response type. This method waits for a maximum of
 218  * ms_timeout milliseconds for a specified response command.
 219  *@brief WaitForResponseTimeout
 220  * @param cmd command to wait for, or CMD_UNKNOWN to take any command.
 221  * @param response struct to copy received command into.
 222  * @param ms_timeout
 223  * @param show_warning
 224  * @return true if command was returned, otherwise false
 225  */
 226 bool WaitForResponseTimeoutW(uint32_t cmd, UsbCommand* response, size_t ms_timeout, bool show_warning) {
 227
 228         UsbCommand resp;
 229
 230         #ifdef COMMS_DEBUG
 231         printf("Waiting for %04x cmd\n", cmd);
 232         #endif
 233
 234         if (response == NULL) {
 235                 response = &resp;
 236         }
 237
 238         uint64_t start_time = msclock();
 239
 240         // Wait until the command is received
 241         while (true) {
 242                 while(getCommand(response)) {
 243                         if (cmd == CMD_UNKNOWN || response->cmd == cmd) {
 244                                 return true;
 245                         }
 246                 }
 247
 248                 if (msclock() - start_time > ms_timeout) {
 249                         break;
 250                 }
 251
 252                 if (msclock() - start_time > 2000 && show_warning) {
 253                         // 2 seconds elapsed (but this doesn't mean the timeout was exceeded)
 254                         PrintAndLog("Waiting for a response from the proxmark...");
 255                         PrintAndLog("You can cancel this operation by pressing the pm3 button");
 256                         show_warning = false;
 257                 }
 258         }
 259         return false;
 260 }
 261
 262
 263 bool WaitForResponseTimeout(uint32_t cmd, UsbCommand* response, size_t ms_timeout) {
 264         return WaitForResponseTimeoutW(cmd, response, ms_timeout, true);
 265 }
 266
 267 bool WaitForResponse(uint32_t cmd, UsbCommand* response) {
 268         return WaitForResponseTimeoutW(cmd, response, -1, true);
 269 }
 270