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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 | static serial_port* port; | |
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 | static bool txcmd_pending; | |
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 SetSerialPort(serial_port* new_port) { | |
54 | port = new_port; | |
55 | } | |
56 | ||
57 | serial_port* GetSerialPort() { | |
58 | return port; | |
59 | } | |
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 | The while-loop below causes hangups at times, when the pm3 unit is unresponsive | |
80 | or disconnected. The main console thread is alive, but comm thread just spins here. | |
81 | Not good.../holiman | |
82 | **/ | |
83 | while(txcmd_pending); | |
84 | txcmd = *c; | |
85 | txcmd_pending = true; | |
86 | } | |
87 | ||
88 | /** | |
89 | * @brief This method should be called when sending a new command to the pm3. In case any old | |
90 | * responses from previous commands are stored in the buffer, a call to this method should clear them. | |
91 | * A better method could have been to have explicit command-ACKS, so we can know which ACK goes to which | |
92 | * operation. Right now we'll just have to live with this. | |
93 | */ | |
94 | void clearCommandBuffer() | |
95 | { | |
96 | //This is a very simple operation | |
97 | pthread_mutex_lock(&cmdBufferMutex); | |
98 | cmd_tail = cmd_head; | |
99 | pthread_mutex_unlock(&cmdBufferMutex); | |
100 | } | |
101 | ||
102 | /** | |
103 | * @brief storeCommand stores a USB command in a circular buffer | |
104 | * @param UC | |
105 | */ | |
106 | void storeCommand(UsbCommand *command) | |
107 | { | |
108 | pthread_mutex_lock(&cmdBufferMutex); | |
109 | if( (cmd_head+1) % CMD_BUFFER_SIZE == cmd_tail) | |
110 | { | |
111 | // If these two are equal, we're about to overwrite in the | |
112 | // circular buffer. | |
113 | PrintAndLog("WARNING: Command buffer about to overwrite command! This needs to be fixed!"); | |
114 | } | |
115 | ||
116 | // Store the command at the 'head' location | |
117 | UsbCommand* destination = &cmdBuffer[cmd_head]; | |
118 | memcpy(destination, command, sizeof(UsbCommand)); | |
119 | ||
120 | cmd_head = (cmd_head +1) % CMD_BUFFER_SIZE; //increment head and wrap | |
121 | pthread_mutex_unlock(&cmdBufferMutex); | |
122 | } | |
123 | ||
124 | ||
125 | /** | |
126 | * @brief getCommand gets a command from an internal circular buffer. | |
127 | * @param response location to write command | |
128 | * @return 1 if response was returned, 0 if nothing has been received | |
129 | */ | |
130 | int getCommand(UsbCommand* response) | |
131 | { | |
132 | pthread_mutex_lock(&cmdBufferMutex); | |
133 | //If head == tail, there's nothing to read, or if we just got initialized | |
134 | if (cmd_head == cmd_tail){ | |
135 | pthread_mutex_unlock(&cmdBufferMutex); | |
136 | return 0; | |
137 | } | |
138 | ||
139 | //Pick out the next unread command | |
140 | UsbCommand* last_unread = &cmdBuffer[cmd_tail]; | |
141 | memcpy(response, last_unread, sizeof(UsbCommand)); | |
142 | //Increment tail - this is a circular buffer, so modulo buffer size | |
143 | cmd_tail = (cmd_tail + 1) % CMD_BUFFER_SIZE; | |
144 | ||
145 | pthread_mutex_unlock(&cmdBufferMutex); | |
146 | return 1; | |
147 | } | |
148 | ||
149 | //----------------------------------------------------------------------------- | |
150 | // Entry point into our code: called whenever we received a packet over USB | |
151 | // that we weren't necessarily expecting, for example a debug print. | |
152 | //----------------------------------------------------------------------------- | |
153 | void UsbCommandReceived(UsbCommand *UC) | |
154 | { | |
155 | switch(UC->cmd) { | |
156 | ||
157 | // First check if we are handling a debug message | |
158 | case CMD_DEBUG_PRINT_STRING: { | |
159 | char s[USB_CMD_DATA_SIZE+1]; | |
160 | memset(s, 0x00, sizeof(s)); | |
161 | size_t len = MIN(UC->arg[0],USB_CMD_DATA_SIZE); | |
162 | memcpy(s,UC->d.asBytes,len); | |
163 | PrintAndLog("#db# %s", s); | |
164 | return; | |
165 | } | |
166 | ||
167 | case CMD_DEBUG_PRINT_INTEGERS: { | |
168 | PrintAndLog("#db# %08x, %08x, %08x \r\n", UC->arg[0], UC->arg[1], UC->arg[2]); | |
169 | return; | |
170 | } | |
171 | ||
172 | case CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K: { | |
173 | // FIXME: This does unsanitised copies into memory when we don't know | |
174 | // the size of the buffer. | |
175 | if (sample_buf) { | |
176 | memcpy(sample_buf+(UC->arg[0]),UC->d.asBytes,UC->arg[1]); | |
177 | } | |
178 | return; | |
179 | } | |
180 | ||
181 | default: { | |
182 | storeCommand(UC); | |
183 | return; | |
184 | } | |
185 | } | |
186 | } | |
187 | ||
188 | // Gets a single command from a proxmark3 device. This should never be used | |
189 | // with the full client. | |
190 | // | |
191 | // @param conn A receiver_arg structure. | |
192 | // @param command A buffer to store the received command. | |
193 | bool ReceiveCommand(receiver_arg* conn, UsbCommand* command) { | |
194 | // Local recieve buffer | |
195 | size_t rxlen; | |
196 | byte_t rx[sizeof(UsbCommand)]; | |
197 | byte_t* prx = rx; | |
198 | ||
199 | while (conn->run) { | |
200 | rxlen = 0; | |
201 | if (uart_receive(port, prx, sizeof(UsbCommand) - (prx-rx), &rxlen) && rxlen) { | |
202 | prx += rxlen; | |
203 | if (prx-rx < sizeof(UsbCommand)) { | |
204 | // Keep reading until we have a completed response. | |
205 | continue; | |
206 | } | |
207 | ||
208 | // We have a completed response. | |
209 | memcpy(command, rx, sizeof(UsbCommand)); | |
210 | return true; | |
211 | } | |
212 | ||
213 | if (prx == rx) { | |
214 | // We got no complete command while waiting, give up control | |
215 | return false; | |
216 | } | |
217 | } | |
218 | ||
219 | // did not get a complete command before being cancelled. | |
220 | return false; | |
221 | } | |
222 | ||
223 | // Worker thread for processing incoming events from the PM3 | |
224 | void *uart_receiver(void *targ) { | |
225 | receiver_arg *conn = (receiver_arg*)targ; | |
226 | UsbCommand rx; | |
227 | ||
228 | while (conn->run) { | |
229 | #ifdef COMMS_DEBUG | |
230 | printf("uart_receiver: get lock\n"); | |
231 | #endif | |
232 | // Lock up receives, in case they try to take it away from us. | |
233 | pthread_mutex_lock(&conn->recv_lock); | |
234 | #ifdef COMMS_DEBUG | |
235 | printf("uart_receiver: lock acquired\n"); | |
236 | #endif | |
237 | ||
238 | if (port == NULL) { | |
239 | #ifdef COMMS_DEBUG | |
240 | printf("uart_receiver: port disappeared\n"); | |
241 | #endif | |
242 | // Our port disappeared, stall. This code path matters for the flasher, | |
243 | // where it is fiddling with the serial port under us. | |
244 | pthread_mutex_unlock(&conn->recv_lock); | |
245 | msleep(10); | |
246 | continue; | |
247 | } | |
248 | ||
249 | bool got_command = ReceiveCommand(conn, &rx); | |
250 | #ifdef COMMS_DEBUG | |
251 | printf("uart_receiver: got command\n"); | |
252 | #endif | |
253 | pthread_mutex_unlock(&conn->recv_lock); | |
254 | ||
255 | if (got_command) { | |
256 | UsbCommandReceived(&rx); | |
257 | } | |
258 | ||
259 | // We aren't normally trying to transmit in the flasher when the port would | |
260 | // be reset, so we can just keep going at this point. | |
261 | if (txcmd_pending) { | |
262 | if (!uart_send(port, (byte_t*) &txcmd, sizeof(UsbCommand))) { | |
263 | PrintAndLog("Sending bytes to proxmark failed"); | |
264 | } | |
265 | txcmd_pending = false; | |
266 | } | |
267 | } | |
268 | ||
269 | pthread_exit(NULL); | |
270 | return NULL; | |
271 | } | |
272 | ||
273 | /** | |
274 | * Waits for a certain response type. This method waits for a maximum of | |
275 | * ms_timeout milliseconds for a specified response command. | |
276 | *@brief WaitForResponseTimeout | |
277 | * @param cmd command to wait for, or CMD_ANY to take any command. | |
278 | * @param response struct to copy received command into. | |
279 | * @param ms_timeout | |
280 | * @param show_warning | |
281 | * @return true if command was returned, otherwise false | |
282 | */ | |
283 | bool WaitForResponseTimeoutW(uint64_t cmd, UsbCommand* response, size_t ms_timeout, bool show_warning) { | |
284 | UsbCommand resp; | |
285 | ||
286 | #ifdef COMMS_DEBUG | |
287 | printf("Waiting for %04x cmd\n", cmd); | |
288 | #endif | |
289 | ||
290 | if (response == NULL) { | |
291 | response = &resp; | |
292 | } | |
293 | ||
294 | uint64_t start_time = msclock(); | |
295 | ||
296 | // Wait until the command is received | |
297 | for (;;) { | |
298 | while(getCommand(response)) { | |
299 | if (cmd == CMD_ANY || response->cmd == cmd) { | |
300 | return true; | |
301 | } | |
302 | } | |
303 | ||
304 | if (msclock() - start_time > ms_timeout) { | |
305 | // We timed out. | |
306 | break; | |
307 | } | |
308 | ||
309 | if (msclock() - start_time > 2000 && show_warning) { | |
310 | // 2 seconds elapsed (but this doesn't mean the timeout was exceeded) | |
311 | PrintAndLog("Waiting for a response from the proxmark..."); | |
312 | PrintAndLog("Don't forget to cancel its operation first by pressing on the button"); | |
313 | break; | |
314 | } | |
315 | } | |
316 | return false; | |
317 | } | |
318 | ||
319 | bool WaitForResponseTimeout(uint64_t cmd, UsbCommand* response, size_t ms_timeout) { | |
320 | return WaitForResponseTimeoutW(cmd, response, ms_timeout, true); | |
321 | } | |
322 | ||
323 | bool WaitForResponse(uint64_t cmd, UsbCommand* response) { | |
324 | return WaitForResponseTimeout(cmd, response, -1); | |
325 | } |