Fixes a double-free issue in CloseProxmark: (#617)
[proxmark3-svn] / 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 "comms.h"
13
14 #include <pthread.h>
15 #ifdef __linux__
16 #include <unistd.h> // for unlink()
17 #endif
18 #include "uart.h"
19 #include "ui.h"
20 #include "common.h"
21 #include "util_posix.h"
22
23
24 // Serial port that we are communicating with the PM3 on.
25 static serial_port sp = NULL;
26 static char *serial_port_name = NULL;
27
28 // If TRUE, then there is no active connection to the PM3, and we will drop commands sent.
29 static bool offline;
30
31 typedef struct {
32 bool run; // If TRUE, continue running the uart_communication thread
33 bool block_after_ACK; // if true, block after receiving an ACK package
34 } communication_arg_t;
35
36 static communication_arg_t conn;
37 static pthread_t USB_communication_thread;
38
39 // Transmit buffer.
40 static UsbCommand txBuffer;
41 static bool txBuffer_pending = false;
42 static pthread_mutex_t txBufferMutex = PTHREAD_MUTEX_INITIALIZER;
43 static pthread_cond_t txBufferSig = PTHREAD_COND_INITIALIZER;
44
45 // Used by UsbReceiveCommand as a ring buffer for messages that are yet to be
46 // processed by a command handler (WaitForResponse{,Timeout})
47 static UsbCommand rxBuffer[CMD_BUFFER_SIZE];
48
49 // Points to the next empty position to write to
50 static int cmd_head = 0;
51
52 // Points to the position of the last unread command
53 static int cmd_tail = 0;
54
55 // to lock rxBuffer operations from different threads
56 static pthread_mutex_t rxBufferMutex = PTHREAD_MUTEX_INITIALIZER;
57
58 // These wrappers are required because it is not possible to access a static
59 // global variable outside of the context of a single file.
60
61 void SetOffline(bool new_offline) {
62 offline = new_offline;
63 }
64
65 bool IsOffline() {
66 return offline;
67 }
68
69 void SendCommand(UsbCommand *c) {
70 #ifdef COMMS_DEBUG
71 printf("Sending %04x cmd\n", c->cmd);
72 #endif
73
74 if (offline) {
75 PrintAndLog("Sending bytes to proxmark failed - offline");
76 return;
77 }
78
79 pthread_mutex_lock(&txBufferMutex);
80 /**
81 This causes hangups at times, when the pm3 unit is unresponsive or disconnected. The main console thread is alive,
82 but comm thread just spins here. Not good.../holiman
83 **/
84 while (txBuffer_pending) {
85 pthread_cond_wait(&txBufferSig, &txBufferMutex); // wait for communication thread to complete sending a previous commmand
86 }
87
88 txBuffer = *c;
89 txBuffer_pending = true;
90 pthread_cond_signal(&txBufferSig); // tell communication thread that a new command can be send
91
92 pthread_mutex_unlock(&txBufferMutex);
93
94 }
95
96
97 /**
98 * @brief This method should be called when sending a new command to the pm3. In case any old
99 * responses from previous commands are stored in the buffer, a call to this method should clear them.
100 * A better method could have been to have explicit command-ACKS, so we can know which ACK goes to which
101 * operation. Right now we'll just have to live with this.
102 */
103 void clearCommandBuffer()
104 {
105 //This is a very simple operation
106 pthread_mutex_lock(&rxBufferMutex);
107 cmd_tail = cmd_head;
108 pthread_mutex_unlock(&rxBufferMutex);
109 }
110
111 /**
112 * @brief storeCommand stores a USB command in a circular buffer
113 * @param UC
114 */
115 static void storeCommand(UsbCommand *command)
116 {
117 pthread_mutex_lock(&rxBufferMutex);
118 if( (cmd_head+1) % CMD_BUFFER_SIZE == cmd_tail)
119 {
120 // If these two are equal, we're about to overwrite in the
121 // circular buffer.
122 PrintAndLog("WARNING: Command buffer about to overwrite command! This needs to be fixed!");
123 }
124
125 // Store the command at the 'head' location
126 UsbCommand* destination = &rxBuffer[cmd_head];
127 memcpy(destination, command, sizeof(UsbCommand));
128
129 cmd_head = (cmd_head +1) % CMD_BUFFER_SIZE; //increment head and wrap
130 pthread_mutex_unlock(&rxBufferMutex);
131 }
132
133
134 /**
135 * @brief getCommand gets a command from an internal circular buffer.
136 * @param response location to write command
137 * @return 1 if response was returned, 0 if nothing has been received
138 */
139 static int getCommand(UsbCommand* response)
140 {
141 pthread_mutex_lock(&rxBufferMutex);
142 //If head == tail, there's nothing to read, or if we just got initialized
143 if (cmd_head == cmd_tail){
144 pthread_mutex_unlock(&rxBufferMutex);
145 return 0;
146 }
147
148 //Pick out the next unread command
149 UsbCommand* last_unread = &rxBuffer[cmd_tail];
150 memcpy(response, last_unread, sizeof(UsbCommand));
151 //Increment tail - this is a circular buffer, so modulo buffer size
152 cmd_tail = (cmd_tail + 1) % CMD_BUFFER_SIZE;
153
154 pthread_mutex_unlock(&rxBufferMutex);
155 return 1;
156 }
157
158
159 //----------------------------------------------------------------------------------
160 // Entry point into our code: called whenever we received a packet over USB.
161 // Handle debug commands directly, store all other commands in circular buffer.
162 //----------------------------------------------------------------------------------
163 static void UsbCommandReceived(UsbCommand *UC)
164 {
165 switch(UC->cmd) {
166 // First check if we are handling a debug message
167 case CMD_DEBUG_PRINT_STRING: {
168 char s[USB_CMD_DATA_SIZE+1];
169 memset(s, 0x00, sizeof(s));
170 size_t len = MIN(UC->arg[0],USB_CMD_DATA_SIZE);
171 memcpy(s,UC->d.asBytes,len);
172 PrintAndLog("#db# %s", s);
173 return;
174 } break;
175
176 case CMD_DEBUG_PRINT_INTEGERS: {
177 PrintAndLog("#db# %08x, %08x, %08x \r\n", UC->arg[0], UC->arg[1], UC->arg[2]);
178 return;
179 } break;
180
181 default:
182 storeCommand(UC);
183 break;
184 }
185
186 }
187
188
189 static void
190 #ifdef __has_attribute
191 #if __has_attribute(force_align_arg_pointer)
192 __attribute__((force_align_arg_pointer))
193 #endif
194 #endif
195 *uart_communication(void *targ) {
196 communication_arg_t *conn = (communication_arg_t*)targ;
197 size_t rxlen;
198 UsbCommand rx;
199 UsbCommand *prx = &rx;
200
201 while (conn->run) {
202 rxlen = 0;
203 bool ACK_received = false;
204 if (uart_receive(sp, (uint8_t *)prx, sizeof(UsbCommand) - (prx-&rx), &rxlen) && rxlen) {
205 prx += rxlen;
206 if (prx-&rx < sizeof(UsbCommand)) {
207 continue;
208 }
209 UsbCommandReceived(&rx);
210 if (rx.cmd == CMD_ACK) {
211 ACK_received = true;
212 }
213 }
214 prx = &rx;
215
216
217 pthread_mutex_lock(&txBufferMutex);
218
219 if (conn->block_after_ACK) {
220 // if we just received an ACK, wait here until a new command is to be transmitted
221 if (ACK_received) {
222 while (!txBuffer_pending) {
223 pthread_cond_wait(&txBufferSig, &txBufferMutex);
224 }
225 }
226 }
227
228 if(txBuffer_pending) {
229 if (!uart_send(sp, (uint8_t*) &txBuffer, sizeof(UsbCommand))) {
230 PrintAndLog("Sending bytes to proxmark failed");
231 }
232 txBuffer_pending = false;
233 pthread_cond_signal(&txBufferSig); // tell main thread that txBuffer is empty
234 }
235
236 pthread_mutex_unlock(&txBufferMutex);
237 }
238
239 pthread_exit(NULL);
240 return NULL;
241 }
242
243
244 /**
245 * Data transfer from Proxmark to client. This method times out after
246 * ms_timeout milliseconds.
247 * @brief GetFromBigBuf
248 * @param dest Destination address for transfer
249 * @param bytes number of bytes to be transferred
250 * @param start_index offset into Proxmark3 BigBuf[]
251 * @param response struct to copy last command (CMD_ACK) into
252 * @param ms_timeout timeout in milliseconds
253 * @param show_warning display message after 2 seconds
254 * @return true if command was returned, otherwise false
255 */
256 bool GetFromBigBuf(uint8_t *dest, int bytes, int start_index, UsbCommand *response, size_t ms_timeout, bool show_warning)
257 {
258 UsbCommand c = {CMD_DOWNLOAD_RAW_ADC_SAMPLES_125K, {start_index, bytes, 0}};
259 SendCommand(&c);
260
261 uint64_t start_time = msclock();
262
263 UsbCommand resp;
264 if (response == NULL) {
265 response = &resp;
266 }
267
268 int bytes_completed = 0;
269 while(true) {
270 if (getCommand(response)) {
271 if (response->cmd == CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K) {
272 int copy_bytes = MIN(bytes - bytes_completed, response->arg[1]);
273 memcpy(dest + response->arg[0], response->d.asBytes, copy_bytes);
274 bytes_completed += copy_bytes;
275 } else if (response->cmd == CMD_ACK) {
276 return true;
277 }
278 }
279
280 if (msclock() - start_time > ms_timeout) {
281 break;
282 }
283
284 if (msclock() - start_time > 2000 && show_warning) {
285 PrintAndLog("Waiting for a response from the proxmark...");
286 PrintAndLog("You can cancel this operation by pressing the pm3 button");
287 show_warning = false;
288 }
289 }
290
291 return false;
292 }
293
294
295 bool OpenProxmark(void *port, bool wait_for_port, int timeout, bool flash_mode) {
296 char *portname = (char *)port;
297 if (!wait_for_port) {
298 sp = uart_open(portname);
299 } else {
300 printf("Waiting for Proxmark to appear on %s ", portname);
301 fflush(stdout);
302 int openCount = 0;
303 do {
304 sp = uart_open(portname);
305 msleep(1000);
306 printf(".");
307 fflush(stdout);
308 } while(++openCount < timeout && (sp == INVALID_SERIAL_PORT || sp == CLAIMED_SERIAL_PORT));
309 printf("\n");
310 }
311
312 // check result of uart opening
313 if (sp == INVALID_SERIAL_PORT) {
314 printf("ERROR: invalid serial port\n");
315 sp = NULL;
316 serial_port_name = NULL;
317 return false;
318 } else if (sp == CLAIMED_SERIAL_PORT) {
319 printf("ERROR: serial port is claimed by another process\n");
320 sp = NULL;
321 serial_port_name = NULL;
322 return false;
323 } else {
324 // start the USB communication thread
325 serial_port_name = portname;
326 conn.run = true;
327 conn.block_after_ACK = flash_mode;
328 pthread_create(&USB_communication_thread, NULL, &uart_communication, &conn);
329 return true;
330 }
331 }
332
333
334 void CloseProxmark(void) {
335 conn.run = false;
336 pthread_join(USB_communication_thread, NULL);
337
338 if (sp) {
339 uart_close(sp);
340 }
341
342 #ifdef __linux__
343 // Fix for linux, it seems that it is extremely slow to release the serial port file descriptor /dev/*
344 if (serial_port_name) {
345 unlink(serial_port_name);
346 }
347 #endif
348
349 // Clean up our state
350 sp = NULL;
351 serial_port_name = NULL;
352 }
353
354
355 /**
356 * Waits for a certain response type. This method waits for a maximum of
357 * ms_timeout milliseconds for a specified response command.
358 *@brief WaitForResponseTimeout
359 * @param cmd command to wait for, or CMD_UNKNOWN to take any command.
360 * @param response struct to copy received command into.
361 * @param ms_timeout
362 * @param show_warning display message after 2 seconds
363 * @return true if command was returned, otherwise false
364 */
365 bool WaitForResponseTimeoutW(uint32_t cmd, UsbCommand* response, size_t ms_timeout, bool show_warning) {
366
367 UsbCommand resp;
368
369 #ifdef COMMS_DEBUG
370 printf("Waiting for %04x cmd\n", cmd);
371 #endif
372
373 if (response == NULL) {
374 response = &resp;
375 }
376
377 uint64_t start_time = msclock();
378
379 // Wait until the command is received
380 while (true) {
381 while(getCommand(response)) {
382 if (cmd == CMD_UNKNOWN || response->cmd == cmd) {
383 return true;
384 }
385 }
386
387 if (msclock() - start_time > ms_timeout) {
388 break;
389 }
390
391 if (msclock() - start_time > 2000 && show_warning) {
392 // 2 seconds elapsed (but this doesn't mean the timeout was exceeded)
393 PrintAndLog("Waiting for a response from the proxmark...");
394 PrintAndLog("You can cancel this operation by pressing the pm3 button");
395 show_warning = false;
396 }
397 }
398 return false;
399 }
400
401
402 bool WaitForResponseTimeout(uint32_t cmd, UsbCommand* response, size_t ms_timeout) {
403 return WaitForResponseTimeoutW(cmd, response, ms_timeout, true);
404 }
405
406 bool WaitForResponse(uint32_t cmd, UsbCommand* response) {
407 return WaitForResponseTimeoutW(cmd, response, -1, true);
408 }
409
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