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