eyefi-config.c

   1 /*
   2  * eyefi-config.c
   3  *
   4  * Copyright (C) 2008 Dave Hansen <dave@sr71.net>
   5  *
   6  * This software may be redistributed and/or modified under the terms of
   7  * the GNU General Public License ("GPL") version 2 as published by the
   8  * Free Software Foundation.
   9  */
  10
  11 #include "eyefi-config.h"
  12
  13 int eyefi_debug_level = 1;
  14
  15 int eyefi_printf(const char *fmt, ...)
  16 {
  17         va_list args;
  18         int r;
  19
  20         va_start(args, fmt);
  21         r = vprintf(fmt, args);
  22         va_end(args);
  23
  24         return r;
  25 }
  26
  27 static char *eyefi_file_name(enum eyefi_file file)
  28 {
  29         switch (file) {
  30         case REQC: return "reqc";
  31         case REQM: return "reqm";
  32         case RSPC: return "rspc";
  33         case RSPM: return "rspm";
  34         }
  35
  36         return NULL;
  37 }
  38
  39 char *eyefi_file_on(enum eyefi_file file, char *mnt)
  40 {
  41         char *filename = eyefi_file_name(file);
  42         char *full = malloc(PATHNAME_MAX);
  43
  44         if (!full)
  45                 return NULL;
  46
  47         sprintf(&full[0], "%s/EyeFi/%s", mnt, filename);
  48         debug_printf(4, "eyefile nr: %d on '%s' is: '%s'\n", file, mnt, &full[0]);
  49         return full;
  50 }
  51
  52 /*
  53  * This lets us get away with a static allocation
  54  * for the buffer.  We make it size*2 so that we're
  55  * guaranteed to be able to get a "size" buffer
  56  * aligned inside of the larger one.
  57  */
  58 static char unaligned_buf[EYEFI_BUF_SIZE*2];
  59 static void *eyefi_buf;
  60
  61 void *eyefi_response(void)
  62 {
  63         return eyefi_buf;
  64 }
  65
  66 void dumpbuf(const char *buffer, int bytesToWrite)
  67 {
  68     int i;
  69     static char linebuf[500];
  70
  71     for (i=0; i < bytesToWrite; i += 16) {
  72         char *tmpbuf = &linebuf[0];
  73         unsigned long sum = 0;
  74         int j;
  75 #define lprintf(args...)        do {            \
  76         tmpbuf += sprintf(tmpbuf, ## args);\
  77 } while (0)
  78
  79         lprintf("[%03d]: ", i);
  80         for (j=0; j < 16; j++) {
  81                 u8 c = ((unsigned char *)buffer)[i+j];
  82                 lprintf("%02x ", (unsigned int)c);
  83                 sum += c;
  84         }
  85         lprintf(" |");
  86         for (j=0; j < 16; j++) {
  87                 u8 c = ((unsigned char *)buffer)[i+j];
  88                 if (c >= 'a' && c <= 'z')
  89                         lprintf("%c", c);
  90                 else if (c >= 'A' && c <= 'Z')
  91                         lprintf("%c", c);
  92                 else if (c >= '0' && c <= '9')
  93                         lprintf("%c", c);
  94                 else if (c >= 0x20 && c <= 127)
  95                         lprintf("%c", c);
  96                 else
  97                         lprintf(".");
  98         }
  99         lprintf("|\n");
 100         if (sum == 0)
 101                 continue;
 102         printf("%s", linebuf);
 103         //if (i > 200)
 104         //      break;
 105     }
 106 }
 107
 108 void read_from(enum eyefi_file);
 109 void write_to(enum eyefi_file, void *, int);
 110
 111 struct card_seq_num eyefi_seq;
 112 struct card_seq_num read_seq_from(enum eyefi_file file)
 113 {
 114         struct card_seq_num *ret;
 115         read_from(file);
 116         ret = eyefi_buf;
 117         return *ret;
 118 }
 119
 120 /*
 121  * For O_DIRECT writes to files, we need
 122  * to be 512 byte aligned on Linux, I think.
 123  * So, just align this to something big
 124  * and be done with it.  FIXME :)
 125  *
 126  * This probably isn't necessary on chdk,
 127  * since I don't think it buffers I/O at
 128  * all.
 129  */
 130 void align_buf(void)
 131 {
 132         unsigned long addr = (unsigned long)&unaligned_buf[EYEFI_BUF_SIZE];
 133         addr &= ~(EYEFI_BUF_SIZE-1);
 134         eyefi_buf = (void *)addr;
 135         debug_printf(4, "buf: %p\n", eyefi_buf);
 136         debug_printf(4, "unaligned: %p\n", &unaligned_buf[0]);
 137 }
 138
 139 /*
 140  * The real manager does this so we might
 141  * as well, too.
 142  */
 143 void zero_card_files(void)
 144 {
 145         char zbuf[EYEFI_BUF_SIZE];
 146
 147         memset(&zbuf[0], 0, EYEFI_BUF_SIZE);
 148         //write_to(REQM, zbuf, EYEFI_BUF_SIZE);
 149         write_to(REQC, zbuf, EYEFI_BUF_SIZE);
 150         write_to(RSPM, zbuf, EYEFI_BUF_SIZE);
 151         write_to(RSPC, zbuf, EYEFI_BUF_SIZE);
 152
 153         read_from(REQM);
 154         read_from(REQC);
 155         read_from(RSPM);
 156         read_from(RSPC);
 157 }
 158
 159 void init_card()
 160 {
 161         char *mnt;
 162         if (eyefi_buf != NULL)
 163                 return;
 164
 165         debug_printf(2, "Initializing card...\n");
 166         mnt = locate_eyefi_mount();
 167         if (mnt == NULL)
 168                 return;
 169
 170         align_buf();
 171         zero_card_files();
 172         eyefi_seq = read_seq_from(RSPC);
 173         if (eyefi_seq.seq == 0)
 174                 eyefi_seq.seq = 0x1234;
 175         eyefi_seq.seq++;
 176         debug_printf(2, "Done initializing card...\n");
 177         debug_printf(2, "seq was: %04x\n", eyefi_seq.seq);
 178 }
 179
 180 static char *eyefi_file(enum eyefi_file file)
 181 {
 182         init_card();
 183         return eyefi_file_on(file, locate_eyefi_mount());
 184 }
 185
 186 void read_from(enum eyefi_file __file)
 187 {
 188         int ret;
 189         int fd;
 190         char *file = eyefi_file(__file);
 191
 192         init_card();
 193
 194 retry:
 195         fd = open(file, O_RDONLY);
 196         if (fd < 0)
 197                 open_error(file, fd);
 198         fd_flush(fd);
 199         ret = read(fd, eyefi_buf, EYEFI_BUF_SIZE);
 200         if (eyefi_debug_level > 3)
 201                 dumpbuf(eyefi_buf, 128);
 202         if (ret < 0) {
 203                 close(fd);
 204                 perror("bad read, retrying...");
 205                 goto retry;
 206                 exit(1);
 207         }
 208         debug_printf(4, "read '%s': bytes: %d\n", file, ret);
 209         /*
 210          * There was a time when I was carefully recording how each response
 211          * looked, and I counted the zeros in each response.  I don't care
 212          * any more.
 213         u8 c;
 214         int zeros = 0;
 215         int i;
 216         for (i=0; i < EYEFI_BUF_SIZE; i++) {
 217                 c = ((char *)eyefi_buf)[i];
 218                 if (c == '\0') {
 219                         zeros++;
 220                         continue;
 221                 }
 222         }
 223         */
 224         free(file);
 225         close(fd);
 226 }
 227
 228 int fake_write = 0;
 229 void write_to(enum eyefi_file __file, void *stuff, int len)
 230 {
 231         int ret;
 232         int fd;
 233         char *file;
 234
 235         if (fake_write)
 236                 return;
 237
 238         init_card();
 239         file = eyefi_file(__file);
 240         if (len == -1)
 241                 len = strlen(stuff);
 242
 243         if (eyefi_debug_level > 3) {
 244                 debug_printf(3, "%s('%s', ..., %d)\n", __func__, file, len);
 245                 dumpbuf(stuff, len);
 246         }
 247         memset(eyefi_buf, 0, EYEFI_BUF_SIZE);
 248         memcpy(eyefi_buf, stuff, len);
 249         fd = open(file, O_RDWR|O_CREAT, 0600);
 250         if (fd < 0 )
 251                 open_error(file, fd);
 252         if (eyefi_debug_level > 3)
 253                 dumpbuf(eyefi_buf, 128);
 254         ret = write(fd, eyefi_buf, EYEFI_BUF_SIZE);
 255         if (ret < 0)
 256                 open_error(file, ret);
 257         ret = fd_flush(fd);
 258         if (ret < 0)
 259                 open_error(file, ret);
 260         close(fd);
 261         debug_printf(3, "wrote %d bytes to '%s' (string was %d bytes)\n", ret, file, len);
 262         if (ret < 0) {
 263                 fprintf(stderr, "error writing to '%s': ", file);
 264                 perror("");
 265                 exit(ret);
 266         }
 267         free(file);
 268 }
 269
 270 #define write_struct(file, s) write_to((file), s, sizeof(*(s)))
 271
 272 void inc_seq(void)
 273 {
 274         /*
 275          * Oddly enough, the sequence number appears
 276          * to be of normal endianness.
 277          */
 278         //u32 tmpseq = be32_to_u32(seq.seq);
 279         //seq.seq = u32_to_be32(tmpseq+1);
 280         eyefi_seq.seq++;
 281         write_struct(REQC, &eyefi_seq);
 282 }
 283
 284 u32 eyefi_current_seq(void)
 285 {
 286         return eyefi_seq.seq;
 287 }
 288
 289 int wait_for_response(void)
 290 {
 291         int good_rsp = 0;
 292         u32 rsp = 0;
 293         int i;
 294         debug_printf(3, "waiting for response...\n");
 295         inc_seq();
 296         for (i = 0; i < 50; i++) {
 297                 struct card_seq_num cardseq = read_seq_from(RSPC);
 298                 debug_printf(3, "read rsp code: %x, looking for: %x raw: %x\n", rsp, eyefi_current_seq(),
 299                                 cardseq.seq);
 300                 rsp = cardseq.seq;
 301                 if (rsp == eyefi_current_seq()) {
 302                         good_rsp = 1;
 303                         break;
 304                 }
 305                 if (eyefi_debug_level > 4) {
 306                         read_from(REQM);
 307                         debug_printf(1, "command issued was: '%c'\n", ((char *)eyefi_buf)[0]);
 308                 }
 309                 usleep(300000);
 310         }
 311         if (!good_rsp) {
 312                 debug_printf(1, "never saw card seq response\n");
 313                 return -1;
 314         }
 315         debug_printf(3, "got good seq (%d), reading RSPM...\n", rsp);
 316         read_from(RSPM);
 317         debug_printf(3, "done reading RSPM\n");
 318         return 0;
 319 }
 320
 321 char *net_test_states[] = {
 322        "not scanning",
 323        "locating network",
 324        "verifying network key",
 325        "waiting for DHCP",
 326        "testing connection to Eye-Fi server",
 327        "success",
 328 };
 329
 330 char *net_test_state_name(u8 state)
 331 {
 332         int size = ARRAY_SIZE(net_test_states);
 333         if (state >= size)
 334                 return "unknown";
 335         return net_test_states[state];
 336 }
 337
 338 const char *net_types[] = {
 339         "none",
 340         "WEP",
 341         "WPA",
 342         "unknown1",
 343         "WPA2",
 344 };
 345 const char net_type_unknown[] = "unknown";
 346
 347 const char *net_type_name(u8 type)
 348 {
 349         int size = ARRAY_SIZE(net_types);
 350         debug_printf(3, "%s(%d): '%s' size: %d\n", __func__, type, net_types[type], size);
 351         if (type >= size)
 352                 return net_type_unknown;
 353         return net_types[type];
 354 }
 355
 356 static char lower(char c)
 357 {
 358         if ((c >= 'A') && (c <= 'Z'))
 359                 c += ('a' - 'A');
 360         return c;
 361 }
 362
 363 int atoh(char c)
 364 {
 365         char lc = lower(c);
 366         if ((c >= '0') && (c <= '9'))
 367                 return c - '0';
 368         else if ((lc >= 'a') && (lc <= 'z'))
 369                 return (lc - 'a') + 10;
 370         debug_printf(5, "non-hex character: '%c'/'%c'\n", c, lc);
 371         return -1;
 372 }
 373
 374 /*
 375  * Take a string like "0ab1" and make it
 376  * a series of bytes: { 0x0a, 0xb1 }
 377  *
 378  * @len is the strlen() of the ascii
 379  *
 380  * Destroys the original string.
 381  */
 382 char *convert_ascii_to_hex(char *ascii, int len)
 383 {
 384         int i;
 385         if (len%2) {
 386                 fprintf(stderr, "%s() must be even number of bytes: %d\n",
 387                 __func__, len);
 388                 exit(2);
 389         }
 390         for (i=0; i < len; i+=2) {
 391                 int high = atoh(ascii[i]);
 392                 int low  = atoh(ascii[i+1]);
 393                 u8 byte = (high<<4 | low);
 394                 if (high < 0 || low < 0) {
 395                         fprintf(stderr, "unable to parse hex string: '%s'\n", ascii);
 396                         return NULL;
 397                 }
 398                 debug_printf(6, "high: %02x low: %02x, both: %02x\n", high, low, byte);
 399                 ascii[i/2] = byte;
 400         }
 401         for (i=len/2; i < len; i++)
 402                 ascii[i] = '\0';
 403         return &ascii[0];
 404 }
 405
 406 int make_network_key(struct network_key *key, char *essid, char *pass)
 407 {
 408         char tmp[WPA_KEY_BYTES+WEP_KEY_BYTES];
 409         int pass_len = strlen(pass);
 410         char *hex_pass;
 411         memset(key, 0, sizeof(*key));
 412
 413         strcpy(&tmp[0], pass);
 414         eyefi_printf(" interpreting passphrase as ");
 415         switch (pass_len) {
 416                 case WPA_KEY_BYTES*2:
 417                         eyefi_printf("hex WPA");
 418                         hex_pass = convert_ascii_to_hex(tmp, pass_len);
 419                         if (!hex_pass)
 420                                 return -EINVAL;
 421                         key->len = pass_len/2;
 422                         memcpy(&key->wpa.key[0], hex_pass, key->len);
 423                         break;
 424                 case WEP_KEY_BYTES*2:
 425                 case WEP_40_KEY_BYTES*2:
 426                         eyefi_printf("hex WEP");
 427                         hex_pass = convert_ascii_to_hex(tmp, strlen(pass));
 428                         if (!hex_pass)
 429                                 return -EINVAL;
 430                         key->len = pass_len/2;
 431                         memcpy(&key->wep.key[0], hex_pass, key->len);
 432                         break;
 433                 default:
 434                         eyefi_printf("ASCII WPA");
 435                         pbkdf2_sha1(pass, essid, strlen(essid), 4096,
 436                                     &key->wpa.key[0], WPA_KEY_BYTES);
 437                         key->len = WPA_KEY_BYTES;
 438                         break;
 439         }
 440         eyefi_printf(" key (%d bytes)\n", key->len);
 441         assert(key->len != 0);
 442         return 0;
 443 }
 444
 445 int card_info_cmd(enum card_info_subcommand cmd)
 446 {
 447         struct card_info_req cir;
 448         cir.o = 'o';
 449         cir.subcommand = cmd;
 450
 451         write_struct(REQM, &cir);
 452         return wait_for_response();
 453 }
 454
 455 u32 fetch_log_length(void)
 456 {
 457         debug_printf(3, "%s()\n", __func__);
 458         card_info_cmd(LOG_LEN);
 459         struct card_info_log_len *loglen = eyefi_buf;
 460         return be32_to_u32(loglen->val);
 461 }
 462
 463 struct card_firmware_info *fetch_card_firmware_info(void)
 464 {
 465         debug_printf(2, "%s()\n", __func__);
 466         card_info_cmd(FIRMWARE_INFO);
 467         return (struct card_firmware_info *)eyefi_buf;
 468         return NULL;
 469 }
 470
 471 struct testbuf {
 472         char cmd;
 473         u8 l1;
 474         char name[100];
 475 };
 476
 477 struct z {
 478         char zeros[100];
 479 } z;
 480
 481
 482 char fwbuf[1<<20];
 483 char zbuf[1<<20];
 484 void testit0(void)
 485 {
 486         char c;
 487         struct testbuf tb;
 488         int i;
 489         int fdin;
 490         int fdout;
 491
 492         card_info_cmd(3);
 493         printf("o3 result:\n");
 494         dumpbuf(eyefi_buf, 64);
 495
 496         memset(&zbuf[0], 0, EYEFI_BUF_SIZE);
 497         zbuf[0] = 'o';
 498         zbuf[1] = 2;
 499
 500         write_to(REQM, &zbuf[0], 16384);
 501         printf("o2 written\n");
 502         printf("seq: %x\n", (int)eyefi_seq.seq);
 503         inc_seq();
 504
 505         for (i=0; i < 4; i++) {
 506                 read_from(RSPC);
 507                 printf("RSPC %d:\n", i);
 508                 dumpbuf(eyefi_buf, 64);
 509                 usleep(20000);
 510         }
 511
 512         printf("RSPM1:\n");
 513         read_from(RSPM);
 514         dumpbuf(eyefi_buf, 64);
 515
 516         memset(&zbuf[0], 0, EYEFI_BUF_SIZE);
 517         write_to(RSPM, zbuf, EYEFI_BUF_SIZE);
 518         write_to(REQM, zbuf, EYEFI_BUF_SIZE);
 519
 520         fdin = open("/home/dave/projects/eyefi/EYEFIFWU.BIN.2.0001", O_RDONLY);
 521         perror("fdin");
 522         fdout = open("/media/EYE-FI/EYEFIFWU.BIN", O_WRONLY|O_CREAT);
 523         perror("fdout");
 524         if (fdin <= 0 || fdout <= 0)
 525                 exit(1);
 526         fd_flush(fdin);
 527         i = read(fdin, &fwbuf[0], 524288);
 528         perror("read");
 529         if (i != 524288)
 530                 exit(2);
 531         i = write(fdout, &fwbuf[0], 524288);
 532         fd_flush(fdout);
 533         perror("write");
 534         if (i != 524288)
 535                 exit(3);
 536
 537         printf("RSPM2:\n");
 538         read_from(RSPM);
 539         dumpbuf(eyefi_buf, 64);
 540
 541         reboot_card();
 542         printf("after reboot:\n");
 543         dumpbuf(eyefi_buf, 64);
 544
 545         printf("cic3:\n");
 546         card_info_cmd(3);
 547         dumpbuf(eyefi_buf, 64);
 548
 549         printf("cic2:\n");
 550         card_info_cmd(2);
 551         dumpbuf(eyefi_buf, 64);
 552
 553         memset(&zbuf[0], 0, EYEFI_BUF_SIZE);
 554         write_to(RSPM, zbuf, EYEFI_BUF_SIZE);
 555         write_to(REQM, zbuf, EYEFI_BUF_SIZE);
 556
 557         printf("cic2v2:\n");
 558         card_info_cmd(2);
 559         dumpbuf(eyefi_buf, 64);
 560
 561         exit(0);
 562         strcpy(tb.name, "www.sr71.net/");
 563         tb.l1 = strlen(tb.name);
 564         for (i = 0; i < 10; i++) {
 565                 tb.cmd = 'O';
 566                 tb.l1 = i;
 567                 write_struct(RSPM, &z);
 568                 write_struct(REQM, &tb);
 569                 wait_for_response();
 570                 printf("buffer after O %d:\n", i);
 571                 dumpbuf(eyefi_buf, 64);
 572                 printf("----------------\n");
 573                 write_struct(REQM, &tb);
 574                 card_info_cmd(i);
 575                 printf("card info(%d):\n", i);
 576                 dumpbuf(eyefi_buf, 64);
 577                 printf("-----------\n");
 578         }
 579         return;
 580
 581         strcpy(tb.name, "/public/eyefi/servname");
 582         strcpy(tb.name, "/config/networks.xml");
 583         //tb.len = strlen(tb.name);
 584         tb.l1 = 0;
 585         for (c = 'O'; c <= 'O'; c++) {
 586                 tb.cmd = c;
 587                 write_struct(REQM, &tb);
 588                 wait_for_response();
 589                 printf("dumping buffer:\n");
 590                 dumpbuf(eyefi_buf, 64);
 591                 printf("buffer dump done\n");
 592         }
 593 }
 594
 595 struct card_info_rsp_key *fetch_card_key(void)
 596 {
 597         struct card_info_rsp_key *key;
 598
 599         debug_printf(2, "%s()\n", __func__);
 600         card_info_cmd(CARD_KEY);
 601         key = eyefi_buf;
 602         return key;
 603 }
 604
 605 int issue_noarg_command(u8 cmd)
 606 {
 607         struct noarg_request req;
 608         debug_printf(4, "%s() cmd: %d\n", __func__, cmd);
 609         req.req = cmd;
 610         write_struct(REQM, &req);
 611         return wait_for_response();
 612 }
 613
 614 struct scanned_net_list *scan_nets(void)
 615 {
 616         struct scanned_net_list *scanned;
 617
 618         debug_printf(2, "%s()\n", __func__);
 619         issue_noarg_command('g');
 620         scanned = eyefi_response();
 621         return scanned;
 622 }
 623
 624 struct configured_net_list *fetch_configured_nets(void)
 625 {
 626         struct configured_net_list *configured;
 627
 628         debug_printf(2, "%s()\n", __func__);
 629         issue_noarg_command('l');
 630         configured = eyefi_buf;
 631         return configured;
 632 }
 633
 634 void reboot_card(void)
 635 {
 636         debug_printf(2, "%s()\n", __func__);
 637         issue_noarg_command('b');
 638 }
 639
 640 int network_action(char cmd, char *essid, char *ascii_password)
 641 {
 642         struct net_request nr;
 643         memset(&nr, 0, sizeof(nr));
 644
 645         nr.req = cmd;
 646         strcpy(&nr.essid[0], essid);
 647         nr.essid_len = strlen(essid);
 648
 649         if (ascii_password) {
 650                 int ret = make_network_key(&nr.key, essid, ascii_password);
 651                 if (ret)
 652                         return ret;
 653         }
 654         write_struct(REQM, &nr);
 655         return wait_for_response();
 656 }
 657
 658 void add_network(char *essid, char *ascii_password)
 659 {
 660         debug_printf(2, "%s('%s', '%s')\n", __func__, essid, ascii_password);
 661         network_action('a', essid, ascii_password);
 662 }
 663
 664 void remove_network(char *essid)
 665 {
 666         debug_printf(2, "%s()\n", __func__);
 667         network_action('d', essid, NULL);
 668 }
 669
 670 int get_log_at_offset(u32 offset)
 671 {
 672         struct fetch_log_cmd cmd;
 673         cmd.m = 'm';
 674         cmd.offset = u32_to_be32(offset);
 675
 676         debug_printf(2, "getting log at offset: %08x\n", offset);
 677         write_struct(REQM, &cmd);
 678         return wait_for_response();
 679 }
 680
 681 void add_log_piece(u8 *log, int log_len, u8 *piece, int piece_pos, int piece_size)
 682 {
 683         debug_printf(2, "%s(%p, %d, %p, %d, %d)\n", __func__, log, log_len, piece, piece_pos, piece_size);
 684         if (piece_pos + piece_size > log_len) {
 685                 int overflow_by = (piece_pos + piece_size) - log_len;
 686                 int piece_overrun_pos = piece_size - overflow_by;
 687                 piece_size -= overflow_by;
 688                 memcpy(&log[0], &piece[piece_overrun_pos], overflow_by);
 689                 debug_printf(2, "writing %d bytes to logbuf[0] from piece[%d]\n",
 690                                 overflow_by, piece_overrun_pos);
 691         }
 692         debug_printf(2, "writing %d bytes to logbuf[%d]\n", piece_size, piece_pos);
 693         memcpy(&log[piece_pos], piece, piece_size);
 694 }
 695
 696 int get_log_into(u8 *resbuf)
 697 {
 698         int total_bytes = 0;
 699         int ret;
 700         int i;
 701         u32 log_start;
 702         u32 log_end;
 703         u32 __log_size = fetch_log_length();
 704         int log_pieces = __log_size/EYEFI_BUF_SIZE;
 705
 706         if (__log_size <= 0)
 707                 return __log_size;
 708
 709         /* There are 8 bytes of header in the first log entry
 710          * to specify where the log starts and ends */
 711         u32 log_size = __log_size - 8;
 712
 713         for (i = 0; i < log_pieces; i++) {
 714                 debug_printf(1, "fetching EyeFi card log part %d/%d...",
 715                                 i+1, log_pieces);
 716                 fflush(NULL);
 717                 ret = get_log_at_offset(EYEFI_BUF_SIZE*i);
 718                 debug_printf(1, "done\n");
 719                 u8 *log_piece;
 720                 u32 log_piece_size;
 721                 if (i == 0) {
 722                         struct first_log_response *log = eyefi_buf;
 723                         log_end = log_size - be32_to_u32(log->log_end);
 724                         log_start = log_size - be32_to_u32(log->log_start);
 725                         debug_printf(2, "log end:   0x%04x\n", log_end);
 726                         debug_printf(2, "log start: 0x%04x\n", log_start);
 727                         log_piece = &log->data[0];
 728                         log_piece_size = ARRAY_SIZE(log->data);
 729                 } else {
 730                         struct rest_log_response *log = eyefi_buf;
 731                         log_piece = &log->data[0];
 732                         log_piece_size = ARRAY_SIZE(log->data);
 733                 }
 734                 add_log_piece(resbuf, log_size, log_piece, log_start, log_piece_size);
 735                 total_bytes += log_piece_size;
 736                 log_start += log_piece_size;
 737                 log_start = log_start % log_size;
 738         }
 739         return total_bytes;
 740 }
 741