USB comm: prepare for @micolous change (PR#463) (#587)

* move communication related code from proxmark3.c and cmdmain.c to new file comms.c
* replace byte_t by uint8_t in uart_posix.c and uart_win32.c
* move OpenProxmark() and CloseProxmark() from flasher.c to flash.c
* move print_lock mutex including initializer to ui.c
* minor changes in printing help texts
* no changes in comms functionality yet

client/comms.c

@@ -0,0 +1,252 @@
+//-----------------------------------------------------------------------------
+// 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 <pthread.h>
+
+#include "comms.h"
+#include "uart.h"
+#include "ui.h"
+#include "common.h"
+#include "data.h"
+#include "util_posix.h"
+
+// Declare globals.
+
+// Serial port that we are communicating with the PM3 on.
+serial_port sp;
+
+// If TRUE, then there is no active connection to the PM3, and we will drop commands sent.
+bool offline;
+
+// Transmit buffer.
+// TODO: Use locks and execute this on the main thread, rather than the receiver
+// thread.  Running on the main thread means we need to be careful in the
+// flasher, as it means SendCommand is no longer async, and can't be used as a
+// buffer for a pending command when the connection is re-established.
+static UsbCommand txcmd;
+volatile static bool txcmd_pending = false;
+
+// Used by UsbReceiveCommand as a ring buffer for messages that are yet to be
+// processed by a command handler (WaitForResponse{,Timeout})
+static UsbCommand cmdBuffer[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 cmdBuffer operations from different threads
+static pthread_mutex_t cmdBufferMutex = PTHREAD_MUTEX_INITIALIZER;
+
+
+void SendCommand(UsbCommand *c) {
+	#if 0
+		printf("Sending %d bytes\n", sizeof(UsbCommand));
+	#endif
+
+	if (offline) {
+		PrintAndLog("Sending bytes to proxmark failed - offline");
+		return;
+    }
+	/**
+	The while-loop below 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(txcmd_pending);
+	txcmd = *c;
+	txcmd_pending = true;
+}
+
+
+/**
+ * @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(&cmdBufferMutex);
+	cmd_tail = cmd_head;
+	pthread_mutex_unlock(&cmdBufferMutex);
+}
+
+/**
+ * @brief storeCommand stores a USB command in a circular buffer
+ * @param UC
+ */
+void storeCommand(UsbCommand *command)
+{
+	pthread_mutex_lock(&cmdBufferMutex);
+	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 = &cmdBuffer[cmd_head];
+	memcpy(destination, command, sizeof(UsbCommand));
+
+	cmd_head = (cmd_head +1) % CMD_BUFFER_SIZE; //increment head and wrap
+	pthread_mutex_unlock(&cmdBufferMutex);
+}
+
+
+/**
+ * @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
+ */
+int getCommand(UsbCommand* response)
+{
+	pthread_mutex_lock(&cmdBufferMutex);
+	//If head == tail, there's nothing to read, or if we just got initialized
+	if (cmd_head == cmd_tail){
+		pthread_mutex_unlock(&cmdBufferMutex);
+		return 0;
+	}
+
+	//Pick out the next unread command
+	UsbCommand* last_unread = &cmdBuffer[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(&cmdBufferMutex);
+	return 1;
+}
+
+
+//-----------------------------------------------------------------------------
+// Entry point into our code: called whenever we received a packet over USB
+// that we weren't necessarily expecting, for example a debug print.
+//-----------------------------------------------------------------------------
+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;
+
+		case CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K: {
+			memcpy(sample_buf+(UC->arg[0]),UC->d.asBytes,UC->arg[1]);
+			return;
+		} break;
+
+		default:
+			storeCommand(UC);
+			break;
+	}
+
+}
+
+
+void
+#ifdef __has_attribute
+#if __has_attribute(force_align_arg_pointer)
+__attribute__((force_align_arg_pointer)) 
+#endif
+#endif
+*uart_receiver(void *targ) {
+	receiver_arg *arg = (receiver_arg*)targ;
+	size_t rxlen;
+	uint8_t rx[sizeof(UsbCommand)];
+	uint8_t *prx = rx;
+
+	while (arg->run) {
+		rxlen = 0;
+		if (uart_receive(sp, prx, sizeof(UsbCommand) - (prx-rx), &rxlen) && rxlen) {
+			prx += rxlen;
+			if (prx-rx < sizeof(UsbCommand)) {
+				continue;
+			}
+			UsbCommandReceived((UsbCommand*)rx);
+		}
+		prx = rx;
+
+		if(txcmd_pending) {
+			if (!uart_send(sp, (uint8_t*) &txcmd, sizeof(UsbCommand))) {
+				PrintAndLog("Sending bytes to proxmark failed");
+			}
+			txcmd_pending = false;
+		}
+	}
+
+	pthread_exit(NULL);
+	return NULL;
+}
+
+
+/**
+ * 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
+ * @param response struct to copy received command into.
+ * @param ms_timeout
+ * @return true if command was returned, otherwise false
+ */
+bool WaitForResponseTimeoutW(uint32_t cmd, UsbCommand* response, size_t ms_timeout, bool show_warning) {
+
+	UsbCommand resp;
+
+	if (response == NULL) {
+		response = &resp;
+	}
+
+	uint64_t start_time = msclock();
+
+	// Wait until the command is received
+	while (true) {
+		while(getCommand(response)) {
+			if(response->cmd == cmd){
+				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 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);
+}
+