firmware/main.c

   1 /* Name: main.c
   2  * Project: labortage-2013-badge
   3  * Author: bg (bg@das-labor.org)
   4  * Creation Date: 2013-10-16
   5  * Tabsize: 4
   6  * Copyright: (c) 2008 by OBJECTIVE DEVELOPMENT Software GmbH, (c) Daniel Otte
   7  * License: GNU GPL v3
   8  * This Revision: $Id: main.c 692 2008-11-07 15:07:40Z cs $
   9  */
  10
  11 /*
  12 This example should run on most AVRs with only little changes. No special
  13 hardware resources except INT0 are used. You may have to change usbconfig.h for
  14 different I/O pins for USB. Please note that USB D+ must be the INT0 pin, or
  15 at least be connected to INT0 as well.
  16 */
  17
  18 #define BUTTON_PIN 5
  19 #define DEBOUNCE_DELAY 50
  20 #define SIMPLE_COUNTER 1
  21 #define NO_CHECK 1
  22 #define ALLOW_SECRET_READ 0
  23
  24 #include <stdint.h>
  25 #include <string.h>
  26 #include <stdbool.h>
  27
  28 #include <avr/io.h>
  29 #include <avr/wdt.h>
  30 #include <avr/eeprom.h>
  31 #include <avr/interrupt.h>  /* for sei() */
  32 #include <util/delay.h>     /* for _delay_ms() */
  33
  34 #include <avr/pgmspace.h>   /* required by usbdrv.h */
  35 #include "usbdrv.h"
  36 #include "requests.h"       /* The custom request numbers we use */
  37 #include "hotp.h"
  38 #include "special_functions.h"
  39
  40 #if !SIMPLE_COUNTER
  41 #include "percnt2.h"
  42 #endif
  43
  44 #include "usb_keyboard_codes.h"
  45
  46 /* ------------------------------------------------------------------------- */
  47 /* ----------------------------- USB interface ----------------------------- */
  48 /* ------------------------------------------------------------------------- */
  49
  50 #define STATE_WAIT 0
  51 #define STATE_SEND_KEY 1
  52 #define STATE_RELEASE_KEY 2
  53 #define STATE_NEXT 3
  54
  55 #define MIN(a, b) (((a) < (b)) ? (a) : (b))
  56
  57 PROGMEM const char usbHidReportDescriptor[USB_CFG_HID_REPORT_DESCRIPTOR_LENGTH] = {
  58     0x05, 0x01,                    /* USAGE_PAGE (Generic Desktop) */
  59     0x09, 0x06,                    /* USAGE (Keyboard) */
  60     0xa1, 0x01,                    /* COLLECTION (Application) */
  61     0x75, 0x01,                    /*   REPORT_SIZE (1) */
  62     0x95, 0x08,                    /*   REPORT_COUNT (8) */
  63     0x05, 0x07,                    /*   USAGE_PAGE (Keyboard)(Key Codes) */
  64     0x19, 0xe0,                    /*   USAGE_MINIMUM (Keyboard LeftControl)(224) */
  65     0x29, 0xe7,                    /*   USAGE_MAXIMUM (Keyboard Right GUI)(231) */
  66     0x15, 0x00,                    /*   LOGICAL_MINIMUM (0) */
  67     0x25, 0x01,                    /*   LOGICAL_MAXIMUM (1) */
  68     0x81, 0x02,                    /*   INPUT (Data,Var,Abs) ; Modifier byte */
  69     0x95, 0x01,                    /*   REPORT_COUNT (1) */
  70     0x75, 0x08,                    /*   REPORT_SIZE (8) */
  71     0x81, 0x03,                    /*   INPUT (Cnst,Var,Abs) ; Reserved byte */
  72     0x95, 0x05,                    /*   REPORT_COUNT (5) */
  73     0x75, 0x01,                    /*   REPORT_SIZE (1) */
  74     0x05, 0x08,                    /*   USAGE_PAGE (LEDs) */
  75     0x19, 0x01,                    /*   USAGE_MINIMUM (Num Lock) */
  76     0x29, 0x05,                    /*   USAGE_MAXIMUM (Kana) */
  77     0x91, 0x02,                    /*   OUTPUT (Data,Var,Abs) ; LED report */
  78     0x95, 0x01,                    /*   REPORT_COUNT (1) */
  79     0x75, 0x03,                    /*   REPORT_SIZE (3) */
  80     0x91, 0x03,                    /*   OUTPUT (Cnst,Var,Abs) ; LED report padding */
  81     0x95, 0x06,                    /*   REPORT_COUNT (6) */
  82     0x75, 0x08,                    /*   REPORT_SIZE (8) */
  83     0x15, 0x00,                    /*   LOGICAL_MINIMUM (0) */
  84     0x25, 0x65,                    /*   LOGICAL_MAXIMUM (101) */
  85     0x05, 0x07,                    /*   USAGE_PAGE (Keyboard)(Key Codes) */
  86     0x19, 0x00,                    /*   USAGE_MINIMUM (Reserved (no event indicated))(0) */
  87     0x29, 0x65,                    /*   USAGE_MAXIMUM (Keyboard Application)(101) */
  88     0x81, 0x00,                    /*   INPUT (Data,Ary,Abs) */
  89     0xc0                           /* END_COLLECTION */
  90 };
  91
  92 static uint16_t secret_length_ee EEMEM = 0;
  93 static uint8_t  secret_ee[32] EEMEM;
  94 static uint8_t  reset_counter_ee EEMEM = 0;
  95 static uint8_t  digits_ee EEMEM = 8;
  96
  97 #if SIMPLE_COUNTER
  98 static uint32_t counter_ee EEMEM = 0;
  99 #endif
 100
 101 static uint8_t dbg_buffer[8];
 102 static uint8_t secret[32];
 103 static uint16_t secret_length_b;
 104 static char token[10];
 105
 106 #define UNI_BUFFER_SIZE 16
 107
 108 static union __attribute__((packed)) {
 109         uint8_t  w8[UNI_BUFFER_SIZE];
 110         uint16_t w16[UNI_BUFFER_SIZE/2];
 111         uint32_t w32[UNI_BUFFER_SIZE/4];
 112         void*    ptr[UNI_BUFFER_SIZE/sizeof(void*)];
 113 } uni_buffer;
 114
 115 static uint8_t current_command;
 116
 117 typedef struct __attribute__((packed)) {
 118     uint8_t modifier;
 119     uint8_t reserved;
 120     uint8_t keycode[6];
 121 } keyboard_report_t;
 122
 123 static keyboard_report_t keyboard_report; /* report sent to the host */
 124 static uchar idleRate;  /* in 4 ms units */
 125 static uchar key_state = STATE_WAIT;
 126 volatile static uchar LED_state = 0xff;
 127 /* ------------------------------------------------------------------------- */
 128
 129 static
 130 void memory_clean(void) {
 131     memset(secret, 0, 32);
 132     secret_length_b = 0;
 133 }
 134
 135 static
 136 uint8_t secret_set(void){
 137 #if !NO_CHECK
 138     uint8_t r;
 139     union {
 140         uint8_t w8[32];
 141         uint16_t w16[16];
 142     } read_back;
 143 #endif
 144     const uint8_t length_B = (secret_length_b + 7) / 8;
 145
 146     eeprom_busy_wait();
 147     eeprom_write_block(secret, secret_ee, length_B);
 148 #if !NO_CHECK
 149     eeprom_busy_wait();
 150     eeprom_read_block(read_back.w8, secret_ee, length_B);
 151     r = memcmp(secret, read_back.w8, length_B);
 152     memory_clean();
 153     memset(read_back.w8, 0, 32);
 154     if (r) {
 155         return 1;
 156     }
 157 #endif
 158     eeprom_busy_wait();
 159     eeprom_write_word(&secret_length_ee, secret_length_b);
 160 #if !NO_CHECK
 161     eeprom_busy_wait();
 162     r = eeprom_read_word(&secret_length_ee) == secret_length_b;
 163     memory_clean();
 164     *read_back.w16 = 0;
 165     if (!r) {
 166         return 1;
 167     }
 168 #else
 169     memory_clean();
 170 #endif
 171
 172     return 0;
 173 }
 174
 175 static
 176 void counter_inc(void){
 177 #if SIMPLE_COUNTER
 178     uint32_t t;
 179     eeprom_busy_wait();
 180     t = eeprom_read_dword(&counter_ee);
 181     eeprom_busy_wait();
 182     eeprom_write_dword(&counter_ee, t + 1);
 183 #else
 184     percnt_inc(0);
 185 #endif
 186 }
 187
 188 static
 189 void counter_reset(void) {
 190     uint8_t reset_counter;
 191     eeprom_busy_wait();
 192     reset_counter = eeprom_read_byte(&reset_counter_ee);
 193 #if SIMPLE_COUNTER
 194     eeprom_busy_wait();
 195     eeprom_write_dword(&counter_ee, 0);
 196 #else
 197     percnt_reset(0);
 198 #endif
 199     eeprom_busy_wait();
 200     eeprom_write_byte(&reset_counter_ee, reset_counter + 1);
 201 }
 202
 203 static
 204 void counter_init(void) {
 205 #if !SIMPLE_COUNTER
 206     eeprom_busy_wait();
 207     if (eeprom_read_byte(&reset_counter_ee) == 0) {
 208         counter_reset();
 209     }
 210     percnt_init(0);
 211 #endif
 212 }
 213
 214 static
 215 void token_generate(void) {
 216     uint16_t s_length_b;
 217     uint8_t digits;
 218     counter_inc();
 219     eeprom_busy_wait();
 220     eeprom_read_block(secret, secret_ee, 32);
 221     eeprom_busy_wait();
 222     s_length_b = eeprom_read_word(&secret_length_ee);
 223     if (s_length_b > 256) {
 224         s_length_b = 256;
 225     }
 226     eeprom_busy_wait();
 227     digits = eeprom_read_byte(&digits_ee);
 228 #if SIMPLE_COUNTER
 229     eeprom_busy_wait();
 230     hotp(token, secret, s_length_b, eeprom_read_dword(&counter_ee) - 1, digits);
 231 #else
 232     hotp(token, secret, s_length_b, percnt_get(0) - 1, digits);
 233 #endif
 234     memory_clean();
 235 }
 236
 237
 238 static
 239 void buildReport(uchar send_key) {
 240     keyboard_report.modifier = 0;
 241     switch (send_key) {
 242     case '1' ... '9':
 243         keyboard_report.keycode[0] = KEY_1 + (send_key-'1');
 244         break;
 245     case '0':
 246         keyboard_report.keycode[0] = KEY_0;
 247         break;
 248     default:
 249         keyboard_report.keycode[0] = 0;
 250     }
 251 }
 252
 253 static
 254 int8_t button_get_debounced(volatile int8_t debounce_count) {
 255     uint8_t v;
 256     v = PINB & _BV(BUTTON_PIN);
 257     while (debounce_count-- && (v == (PINB & _BV(BUTTON_PIN)))) {
 258         ;
 259     }
 260     if (debounce_count != -1) {
 261         return -1;
 262     }
 263     return v ? 0 : 1;
 264 }
 265
 266 usbMsgLen_t usbFunctionSetup(uchar data[8])
 267 {
 268         usbRequest_t    *rq = (usbRequest_t *)data;
 269         if ((rq->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_CLASS) {    /* class request type */
 270             switch(rq->bRequest) {
 271         case USBRQ_HID_GET_REPORT: /* send "no keys pressed" if asked here */
 272             /* wValue: ReportType (highbyte), ReportID (lowbyte) */
 273             usbMsgPtr = (void *)&keyboard_report; /* we only have this one */
 274             keyboard_report.modifier = 0;
 275             keyboard_report.keycode[0] = 0;
 276             return sizeof(keyboard_report);
 277         case USBRQ_HID_SET_REPORT: /* if wLength == 1, should be LED state */
 278             if (rq->wLength.word == 1) {
 279                 current_command = LED_WRITE;
 280                 return USB_NO_MSG;
 281             }
 282             return 0;
 283         case USBRQ_HID_GET_IDLE: /* send idle rate to PC as required by spec */
 284             usbMsgPtr = &idleRate;
 285             return 1;
 286         case USBRQ_HID_SET_IDLE: /* save idle rate as required by spec */
 287             idleRate = rq->wValue.bytes[1];
 288             return 0;
 289         }
 290     }
 291     if ((rq->bmRequestType & USBRQ_TYPE_MASK) == USBRQ_TYPE_VENDOR) {
 292                 current_command = rq->bRequest;
 293         usbMsgPtr = uni_buffer.w8;
 294         switch(rq->bRequest)
 295                 {
 296         case CUSTOM_RQ_SET_SECRET:
 297             secret_length_b = rq->wValue.word;
 298             if (secret_length_b > 256) {
 299                 secret_length_b = 256;
 300             }
 301             uni_buffer.w8[0] = 0;
 302             return USB_NO_MSG;
 303         case CUSTOM_RQ_INC_COUNTER:
 304             counter_inc();
 305             return 0;
 306         case CUSTOM_RQ_GET_COUNTER:
 307 #if SIMPLE_COUNTER
 308             eeprom_busy_wait();
 309             uni_buffer.w32[0] = eeprom_read_dword(&counter_ee);
 310 #else
 311             uni_buffer.w32[0] = percnt_get(0);
 312 #endif
 313             return 4;
 314         case CUSTOM_RQ_RESET_COUNTER:
 315             counter_reset();
 316             return 0;
 317         case CUSTOM_RQ_GET_RESET_COUNTER:
 318             eeprom_busy_wait();
 319             uni_buffer.w8[0] = eeprom_read_byte(&reset_counter_ee);
 320             return 1;
 321         case CUSTOM_RQ_SET_DIGITS:
 322             if (rq->wValue.bytes[0] < 6) {
 323                 rq->wValue.bytes[0] = 6;
 324             }
 325             if (rq->wValue.bytes[0] > 9) {
 326                 rq->wValue.bytes[0] = 9;
 327             }
 328             eeprom_busy_wait();
 329             eeprom_write_byte(&digits_ee, rq->wValue.bytes[0]);
 330             return 0;
 331         case CUSTOM_RQ_GET_DIGITS:
 332             eeprom_busy_wait();
 333             uni_buffer.w8[0] = eeprom_read_byte(&digits_ee);
 334             return 1;
 335         case CUSTOM_RQ_GET_TOKEN:
 336             token_generate();
 337             usbMsgPtr = (usbMsgPtr_t)token;
 338             return strlen(token);
 339         case CUSTOM_RQ_PRESS_BUTTON:
 340             key_state = STATE_SEND_KEY;
 341             return 0;
 342         case CUSTOM_RQ_CLR_DBG:
 343             memset(dbg_buffer, 0, sizeof(dbg_buffer));
 344             return 0;
 345                 case CUSTOM_RQ_SET_DBG:
 346                         return USB_NO_MSG;
 347                 case CUSTOM_RQ_GET_DBG:
 348                         usbMsgPtr = dbg_buffer;
 349                         return MIN(8, rq->wLength.word);
 350                 case CUSTOM_RQ_RESET:
 351                         soft_reset((uint8_t)(rq->wValue.word));
 352                         break;
 353                 case CUSTOM_RQ_READ_BUTTON:
 354                         uni_buffer.w8[0] = button_get_debounced(DEBOUNCE_DELAY);
 355                         return 1;
 356 #if ALLOW_SECRET_READ
 357                 case CUSTOM_RQ_GET_SECRET:
 358             uni_buffer.w8[0] = 0;
 359                     return USB_NO_MSG;
 360 #else
 361 #endif
 362         default:
 363             return 0;
 364                 }
 365     }
 366
 367     return 0;   /* default for not implemented requests: return no data back to host */
 368 }
 369
 370
 371 uchar usbFunctionWrite(uchar *data, uchar len)
 372 {
 373         switch(current_command){
 374
 375         case LED_WRITE:
 376             if (data[0] != LED_state)
 377                 LED_state = data[0];
 378             return 1; /* Data read, not expecting more */
 379         case CUSTOM_RQ_SET_SECRET:
 380         {
 381             if (uni_buffer.w8[0] < (secret_length_b + 7) / 8) {
 382                 memcpy(&secret[uni_buffer.w8[0]], data, len);
 383                 uni_buffer.w8[0] += len;
 384             }
 385             if (uni_buffer.w8[0] >= (secret_length_b + 7) / 8) {
 386                 secret_set();
 387                 return 1;
 388             }
 389             return 0;
 390         }
 391         case CUSTOM_RQ_SET_DBG:
 392                 if(len > sizeof(dbg_buffer)){
 393                         len = sizeof(dbg_buffer);
 394                 }
 395                 memcpy(dbg_buffer, data, len);
 396         }
 397         return 1;
 398 }
 399
 400 uchar usbFunctionRead(uchar *data, uchar len){
 401 #if ALLOW_SECRET_READ || 1
 402     uchar r;
 403     uint8_t s_length_B;
 404     switch(current_command){
 405     case CUSTOM_RQ_GET_SECRET:
 406         eeprom_busy_wait();
 407         s_length_B = (eeprom_read_word(&secret_length_ee) + 7) / 8;
 408         r = MIN(len, s_length_B - uni_buffer.w8[0]);
 409         eeprom_busy_wait();
 410         eeprom_read_block(data, secret_ee + uni_buffer.w8[0], r);
 411         uni_buffer.w8[0] += r;
 412         return r;
 413     }
 414 #endif
 415     return 0;
 416 }
 417
 418 static void calibrateOscillator(void)
 419 {
 420 uchar       step = 128;
 421 uchar       trialValue = 0, optimumValue;
 422 int         x, optimumDev, targetValue = (unsigned)(1499 * (double)F_CPU / 10.5e6 + 0.5);
 423
 424     /* do a binary search: */
 425     do {
 426         OSCCAL = trialValue + step;
 427         x = usbMeasureFrameLength();    /* proportional to current real frequency */
 428         if(x < targetValue)             /* frequency still too low */
 429             trialValue += step;
 430         step >>= 1;
 431     } while(step > 0);
 432     /* We have a precision of +/- 1 for optimum OSCCAL here */
 433     /* now do a neighborhood search for optimum value */
 434     optimumValue = trialValue;
 435     optimumDev = x; /* this is certainly far away from optimum */
 436     for (OSCCAL = trialValue - 1; OSCCAL <= trialValue + 1; OSCCAL++){
 437         x = usbMeasureFrameLength() - targetValue;
 438         if (x < 0)
 439             x = -x;
 440         if (x < optimumDev) {
 441             optimumDev = x;
 442             optimumValue = OSCCAL;
 443         }
 444     }
 445     OSCCAL = optimumValue;
 446 }
 447
 448
 449 void usbEventResetReady(void)
 450 {
 451     cli();  /* usbMeasureFrameLength() counts CPU cycles, so disable interrupts. */
 452     calibrateOscillator();
 453     sei();
 454 }
 455
 456 /* ------------------------------------------------------------------------- */
 457
 458 int main(void)
 459 {
 460         size_t idx = 0;
 461         int8_t i = 0, last_stable_button_state = 0;
 462
 463     wdt_enable(WDTO_1S);
 464     /* Even if you don't use the watchdog, turn it off here. On newer devices,
 465      * the status of the watchdog (on/off, period) is PRESERVED OVER RESET!
 466      */
 467     /* RESET status: all port bits are inputs without pull-up.
 468      * That's the way we need D+ and D-. Therefore we don't need any
 469      * additional hardware initialization.
 470      */
 471
 472     counter_init();
 473     usbInit();
 474     usbDeviceDisconnect();  /* enforce re-enumeration, do this while interrupts are disabled! */
 475     while(--i){             /* fake USB disconnect for ~512 ms */
 476         wdt_reset();
 477         _delay_ms(2);
 478     }
 479     usbDeviceConnect();
 480
 481     sei();
 482     DDRB &= ~_BV(BUTTON_PIN); /* make button pin input */
 483     PORTB |= _BV(BUTTON_PIN); /* turn on pull-up resistor */
 484
 485     for(;;){                /* main event loop */
 486         wdt_reset();
 487         usbPoll();
 488
 489         i = button_get_debounced(DEBOUNCE_DELAY);
 490         if (i != -1) {
 491             if (last_stable_button_state == 0 && i == 1) {
 492                 token_generate();
 493                 key_state = STATE_SEND_KEY;
 494             }
 495             last_stable_button_state = i;
 496         }
 497
 498         if(usbInterruptIsReady() && key_state != STATE_WAIT){
 499             switch(key_state) {
 500             case STATE_SEND_KEY:
 501                 buildReport(token[idx]);
 502                 key_state = STATE_RELEASE_KEY; /* release next */
 503                 break;
 504             case STATE_RELEASE_KEY:
 505                 buildReport(0);
 506                 ++idx;
 507                 if (token[idx] == '\0') {
 508                     idx = 0;
 509                     key_state = STATE_WAIT;
 510                 } else {
 511                     key_state = STATE_SEND_KEY;
 512                 }
 513                 break;
 514             default:
 515                 key_state = STATE_WAIT; /* should not happen */
 516             }
 517                         /* start sending */
 518             usbSetInterrupt((void *)&keyboard_report, sizeof(keyboard_report));
 519
 520         }
 521
 522     }
 523     return 0;
 524 }
 525
 526 /* ------------------------------------------------------------------------- */