X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/e17660d5f7dfa44447068e7897ee6454157d2ae1..afdcb8c159a73aba95a017f1cfec98e8fa2b93c1:/client/comms.c diff --git a/client/comms.c b/client/comms.c new file mode 100644 index 00000000..abbae386 --- /dev/null +++ b/client/comms.c @@ -0,0 +1,325 @@ +//----------------------------------------------------------------------------- +// Copyright (C) 2009 Michael Gernoth +// Copyright (C) 2010 iZsh +// +// 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 + +#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. +static serial_port* port; + +// If TRUE, then there is no active connection to the PM3, and we will drop commands sent. +static 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; +static bool txcmd_pending; + +// 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; + +// These wrappers are required because it is not possible to access a static +// global variable outside of the context of a single file. + +void SetSerialPort(serial_port* new_port) { + port = new_port; +} + +serial_port* GetSerialPort() { + return port; +} + +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; + } + /** + 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; + } + + case CMD_DEBUG_PRINT_INTEGERS: { + PrintAndLog("#db# %08x, %08x, %08x \r\n", UC->arg[0], UC->arg[1], UC->arg[2]); + return; + } + + case CMD_DOWNLOADED_RAW_ADC_SAMPLES_125K: { + // FIXME: This does unsanitised copies into memory when we don't know + // the size of the buffer. + if (sample_buf) { + memcpy(sample_buf+(UC->arg[0]),UC->d.asBytes,UC->arg[1]); + } + return; + } + + default: { + storeCommand(UC); + return; + } + } +} + +// Gets a single command from a proxmark3 device. This should never be used +// with the full client. +// +// @param conn A receiver_arg structure. +// @param command A buffer to store the received command. +bool ReceiveCommand(receiver_arg* conn, UsbCommand* command) { + // Local recieve buffer + size_t rxlen; + byte_t rx[sizeof(UsbCommand)]; + byte_t* prx = rx; + + while (conn->run) { + rxlen = 0; + if (uart_receive(port, prx, sizeof(UsbCommand) - (prx-rx), &rxlen) && rxlen) { + prx += rxlen; + if (prx-rx < sizeof(UsbCommand)) { + // Keep reading until we have a completed response. + continue; + } + + // We have a completed response. + memcpy(command, rx, sizeof(UsbCommand)); + return true; + } + + if (prx == rx) { + // We got no complete command while waiting, give up control + return false; + } + } + + // did not get a complete command before being cancelled. + return false; +} + +// Worker thread for processing incoming events from the PM3 +void *uart_receiver(void *targ) { + receiver_arg *conn = (receiver_arg*)targ; + UsbCommand rx; + + while (conn->run) { + #ifdef COMMS_DEBUG + printf("uart_receiver: get lock\n"); + #endif + // Lock up receives, in case they try to take it away from us. + pthread_mutex_lock(&conn->recv_lock); + #ifdef COMMS_DEBUG + printf("uart_receiver: lock acquired\n"); + #endif + + if (port == NULL) { + #ifdef COMMS_DEBUG + printf("uart_receiver: port disappeared\n"); + #endif + // Our port disappeared, stall. This code path matters for the flasher, + // where it is fiddling with the serial port under us. + pthread_mutex_unlock(&conn->recv_lock); + msleep(10); + continue; + } + + bool got_command = ReceiveCommand(conn, &rx); + #ifdef COMMS_DEBUG + printf("uart_receiver: got command\n"); + #endif + pthread_mutex_unlock(&conn->recv_lock); + + if (got_command) { + UsbCommandReceived(&rx); + } + + // We aren't normally trying to transmit in the flasher when the port would + // be reset, so we can just keep going at this point. + if (txcmd_pending) { + if (!uart_send(port, (byte_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, or CMD_ANY to take any command. + * @param response struct to copy received command into. + * @param ms_timeout + * @param show_warning + * @return true if command was returned, otherwise false + */ +bool WaitForResponseTimeoutW(uint64_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 + for (;;) { + while(getCommand(response)) { + if (cmd == CMD_ANY || response->cmd == cmd) { + return true; + } + } + + if (msclock() - start_time > ms_timeout) { + // We timed out. + 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("Don't forget to cancel its operation first by pressing on the button"); + break; + } + } + return false; +} + +bool WaitForResponseTimeout(uint64_t cmd, UsbCommand* response, size_t ms_timeout) { + return WaitForResponseTimeoutW(cmd, response, ms_timeout, true); +} + +bool WaitForResponse(uint64_t cmd, UsbCommand* response) { + return WaitForResponseTimeout(cmd, response, -1); +}