command.c

   1 /*
   2  * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /** \file command.c does client authentication and executes server commands */
  20
  21 #include <sys/time.h> /* gettimeofday */
  22 #include "server.cmdline.h"
  23 #include "afs.h"
  24 #include "server.h"
  25 #include "vss.h"
  26 #include "send.h"
  27 #include "rc4.h"
  28 #include <openssl/rc4.h>
  29 #include "error.h"
  30 #include "net.h"
  31 #include "daemon.h"
  32 #include "string.h"
  33 #include "fd.h"
  34 #include "user_list.h"
  35 #include "server_command_list.h"
  36
  37 /** commands including options must be shorter than this */
  38 #define MAX_COMMAND_LEN 4096
  39
  40 static RC4_KEY rc4_recv_key;
  41 static RC4_KEY rc4_send_key;
  42 static unsigned char rc4_buf[2 * RC4_KEY_LEN];
  43
  44 extern const char *status_item_list[NUM_STAT_ITEMS];
  45 extern struct misc_meta_data *mmd;
  46 extern struct audio_file_selector selectors[];
  47 extern struct sender senders[];
  48 extern char *user_list;
  49
  50 static void dummy(__a_unused int s)
  51 {}
  52
  53 static void mmd_dup(struct misc_meta_data *new_mmd)
  54 {
  55         mmd_lock();
  56         *new_mmd = *mmd;
  57         mmd_unlock();
  58 }
  59
  60 /*
  61  * compute human readable string containing
  62  * vss status for given integer value
  63  */
  64 static char *vss_status_tohuman(unsigned int flags)
  65 {
  66         if (flags & VSS_PLAYING)
  67                 return para_strdup("playing");
  68         else if (flags & VSS_NEXT)
  69                 return para_strdup("stopped");
  70         else
  71                 return para_strdup("paused");
  72 }
  73
  74 /*
  75  * return human readable permission string. Never returns NULL.
  76  */
  77 static char *cmd_perms_itohuman(unsigned int perms)
  78 {
  79         char *msg = para_malloc(5 * sizeof(char));
  80
  81         msg[0] = perms & AFS_READ? 'a' : '-';
  82         msg[1] = perms & AFS_WRITE? 'A' : '-';
  83         msg[2] = perms & VSS_READ? 'v' : '-';
  84         msg[3] = perms & VSS_WRITE? 'V' : '-';
  85         msg[4] = '\0';
  86         return msg;
  87 }
  88
  89 /*
  90  * Never returns NULL.
  91  */
  92 static char *vss_get_status_flags(unsigned int flags)
  93 {
  94         char *msg = para_malloc(5 * sizeof(char));
  95
  96         msg[0] = (flags & VSS_PLAYING)? 'P' : '_';
  97         msg[1] = (flags & VSS_NOMORE)? 'O' : '_';
  98         msg[2] = (flags & VSS_NEXT)? 'N' : '_';
  99         msg[3] = (flags & VSS_REPOS)? 'R' : '_';
 100         msg[4] = '\0';
 101         return msg;
 102 }
 103
 104 /*
 105  * compute status bar string. Never returns NULL
 106  */
 107 static char *get_sb_string(struct misc_meta_data *nmmd)
 108 {
 109         char *base, *ret;
 110         long long unsigned secs = 0, rsecs = 0, percent = 0;
 111
 112         base = para_basename(nmmd->filename);
 113         if (!base)
 114                 return para_strdup("");
 115         if (!base[0])
 116                 return base;
 117         if (nmmd->afi.chunks_total) {
 118                 secs = (long long) nmmd->afi.seconds_total * nmmd->chunks_sent
 119                         / nmmd->afi.chunks_total;
 120                 rsecs = (long long) nmmd->afi.seconds_total *
 121                         (nmmd->afi.chunks_total - nmmd->chunks_sent)
 122                         / nmmd->afi.chunks_total;
 123                 percent = 100 * ((nmmd->chunks_sent + 5) / 10)
 124                         / ((nmmd->afi.chunks_total + 5) / 10);
 125         }
 126         ret = make_message("%llu:%02llu [%llu:%02llu] (%llu%%) %s",
 127                 secs / 60, secs % 60,
 128                 rsecs / 60, rsecs % 60,
 129                 percent,
 130                 base
 131         );
 132         free(base);
 133         return ret;
 134 }
 135
 136 static char *get_status(struct misc_meta_data *nmmd)
 137 {
 138         char *bar, *ret, mtime[30] = "";
 139         char *status, *flags; /* vss status info */
 140         char *ut = uptime_str();
 141         long offset = (nmmd->offset + 500) / 1000;
 142         struct timeval now;
 143         struct tm mtime_tm;
 144
 145         if (nmmd->audio_format >= 0) {
 146                 localtime_r(&nmmd->mtime, &mtime_tm);
 147                 strftime(mtime, 29, "%a %b %d %Y", &mtime_tm);
 148         }
 149         /* report real status */
 150         status = vss_status_tohuman(nmmd->vss_status_flags);
 151         flags = vss_get_status_flags(nmmd->vss_status_flags);
 152         bar = para_basename(nmmd->filename);
 153         gettimeofday(&now, NULL);
 154         ret = make_message(
 155                 "%s:%lu\n"      "%s:%s\n"               "%s:%i\n"       "%s:%u\n"
 156                 "%s:%s\n"       "%s:%s\n"       "%s:%s\n"       "%s:%s\n"
 157                 "%s:%li\n"      "%s:%s\n"       "%s"            "%s"
 158                 "%s:%s\n"       "%s:%lu.%lu\n"  "%s:%lu.%lu\n",
 159                 status_item_list[SI_FILE_SIZE], nmmd->size / 1024,
 160                 status_item_list[SI_MTIME], mtime,
 161                 status_item_list[SI_LENGTH], nmmd->afi.seconds_total,
 162                 status_item_list[SI_NUM_PLAYED], nmmd->num_played,
 163
 164                 status_item_list[SI_STATUS_BAR], bar ? bar : "(none)",
 165                 status_item_list[SI_STATUS], status,
 166                 status_item_list[SI_STATUS_FLAGS], flags,
 167                 status_item_list[SI_SELECTOR], selectors[nmmd->selector_num].name,
 168
 169                 status_item_list[SI_OFFSET], offset,
 170                 status_item_list[SI_FORMAT], audio_format_name(nmmd->audio_format),
 171                 nmmd->selector_info,
 172                 nmmd->afi.info_string,
 173
 174                 status_item_list[SI_UPTIME], ut,
 175                 status_item_list[SI_STREAM_START],
 176                         (long unsigned)nmmd->stream_start.tv_sec,
 177                         (long unsigned)nmmd->stream_start.tv_usec,
 178                 status_item_list[SI_CURRENT_TIME],
 179                         (long unsigned)now.tv_sec,
 180                         (long unsigned)now.tv_usec
 181
 182         );
 183         free(bar);
 184         free(flags);
 185         free(status);
 186         free(ut);
 187         return ret;
 188 }
 189
 190 static int check_sender_args(int argc, char **argv, struct sender_command_data *scd)
 191 {
 192         int i;
 193         /* this has to match sender.h */
 194         const char *subcmds[] = {"add", "delete", "allow", "deny", "on", "off", NULL};
 195
 196         scd->sender_num = -1;
 197         if (argc < 2)
 198                 return -E_COMMAND_SYNTAX;
 199         for (i = 0; senders[i].name; i++)
 200                 if (!strcmp(senders[i].name, argv[1]))
 201                         break;
 202         PARA_DEBUG_LOG("%d:%s\n", argc, argv[1]);
 203         if (!senders[i].name)
 204                 return -E_COMMAND_SYNTAX;
 205         scd->sender_num = i;
 206         for (i = 0; subcmds[i]; i++)
 207                 if (!strcmp(subcmds[i], argv[2]))
 208                         break;
 209         if (!subcmds[i])
 210                 return -E_COMMAND_SYNTAX;
 211         scd->cmd_num = i;
 212         mmd_lock();
 213         if (!senders[scd->sender_num].client_cmds[scd->cmd_num]) {
 214                 mmd_unlock();
 215                 return -E_SENDER_CMD;
 216         }
 217         mmd_unlock();
 218         switch (scd->cmd_num) {
 219         case SENDER_ON:
 220         case SENDER_OFF:
 221                 if (argc != 3)
 222                         return -E_COMMAND_SYNTAX;
 223                 break;
 224         case SENDER_DENY:
 225         case SENDER_ALLOW:
 226                 if (argc != 4 && argc != 5)
 227                         return -E_COMMAND_SYNTAX;
 228                 if (!inet_aton(argv[3], &scd->addr))
 229                         return -E_COMMAND_SYNTAX;
 230                 scd->netmask = 32;
 231                 if (argc == 5) {
 232                         scd->netmask = atoi(argv[4]);
 233                         if (scd->netmask < 0 || scd->netmask > 32)
 234                                 return -E_COMMAND_SYNTAX;
 235                 }
 236                 break;
 237         case SENDER_ADD:
 238         case SENDER_DELETE:
 239                 if (argc != 4 && argc != 5)
 240                         return -E_COMMAND_SYNTAX;
 241                 if (!inet_aton(argv[3], &scd->addr))
 242                         return -E_COMMAND_SYNTAX;
 243                 scd->port = -1;
 244                 if (argc == 5) {
 245                         scd->port = atoi(argv[4]);
 246                         if (scd->port < 0 || scd->port > 65535)
 247                                 return -E_COMMAND_SYNTAX;
 248                 }
 249                 break;
 250         default:
 251                 return -E_COMMAND_SYNTAX;
 252         }
 253         return 1;
 254 }
 255
 256 int com_sender(int fd, int argc, char **argv)
 257 {
 258         int i, ret;
 259         struct sender_command_data scd;
 260
 261         if (argc < 2) {
 262                 char *msg = NULL;
 263                 for (i = 0; senders[i].name; i++) {
 264                         char *tmp = make_message("%s%s\n",
 265                                 msg? msg : "", senders[i].name);
 266                         free(msg);
 267                         msg = tmp;
 268                 }
 269                 ret = send_buffer(fd, msg);
 270                 free(msg);
 271                 return ret;
 272         }
 273         ret = check_sender_args(argc, argv, &scd);
 274         if (ret < 0) {
 275                 char *msg;
 276                 if (scd.sender_num < 0)
 277                         return ret;
 278                 msg = senders[scd.sender_num].help();
 279                 send_buffer(fd, msg);
 280                 free(msg);
 281                 return 1;
 282         }
 283         for (i = 0; i < 10; i++) {
 284                 mmd_lock();
 285                 if (mmd->sender_cmd_data.cmd_num >= 0) {
 286                         mmd_unlock();
 287                         usleep(100 * 1000);
 288                         continue;
 289                 }
 290                 mmd->sender_cmd_data = scd;
 291                 mmd_unlock();
 292                 break;
 293         }
 294         return (i < 10)? 1 : -E_LOCK;
 295 }
 296
 297 /* server info */
 298 int com_si(int fd, int argc, __a_unused char **argv)
 299 {
 300         int i, ret;
 301         char *ut;
 302         char *selector_string = NULL, *sender_info = NULL, *sender_list = NULL;
 303
 304         if (argc != 1)
 305                 return -E_COMMAND_SYNTAX;
 306         mmd_lock();
 307         for (i = 0; selectors[i].name; i++) {
 308                 selector_string = para_strcat(selector_string, selectors[i].name);
 309                 selector_string = para_strcat(selector_string, " ");
 310         }
 311         for (i = 0; senders[i].name; i++) {
 312                 char *info = senders[i].info();
 313                 sender_info = para_strcat(sender_info, info);
 314                 free(info);
 315                 sender_list = para_strcat(sender_list, senders[i].name);
 316                 sender_list = para_strcat(sender_list, " ");
 317         }
 318         ut = uptime_str();
 319         ret = send_va_buffer(fd, "up: %s\nplayed: %u\n"
 320                 "pid: %d\n"
 321                 "connections (active/accepted/total): %u/%u/%u\n"
 322                 "current loglevel: %i\n"
 323                 "supported audio file selectors: %s\n"
 324                 "supported audio formats: %s\n"
 325                 "supported senders: %s\n"
 326                 "%s",
 327                 ut, mmd->num_played,
 328                 getppid(),
 329                 mmd->active_connections,
 330                 mmd->num_commands,
 331                 mmd->num_connects,
 332                 conf.loglevel_arg,
 333                 selector_string,
 334                 supported_audio_formats(),
 335                 sender_list,
 336                 sender_info
 337         );
 338         mmd_unlock();
 339         free(ut);
 340         free(selector_string);
 341         free(sender_list);
 342         free(sender_info);
 343         return ret;
 344 }
 345
 346 /* version */
 347 int com_version(int fd, int argc, __a_unused char **argv)
 348 {
 349         if (argc != 1)
 350                 return -E_COMMAND_SYNTAX;
 351         return send_buffer(fd, VERSION_TEXT("server")
 352                 "built: " BUILD_DATE "\n"
 353                 SYSTEM ", " CC_VERSION "\n"
 354         );
 355 }
 356
 357 /* sc */
 358 int com_sc(int fd, int argc, char **argv)
 359 {
 360         char *name = NULL;
 361         int ret, old = 0, count = -1; /* print af change forever */
 362
 363         if (argc > 1)
 364                 count = atoi(argv[1]);
 365 repeat:
 366         mmd_lock();
 367         if (old != mmd->num_played) {
 368                 old = mmd->num_played;
 369                 name = para_strdup(mmd->filename);
 370         }
 371         mmd_unlock();
 372         if (name) {
 373                 ret = send_va_buffer(fd, "%s\n", name);
 374                 free(name);
 375                 name = NULL;
 376                 if (ret < 0)
 377                         return ret;
 378                 if (argc > 1 && !--count)
 379                         return 1;
 380         }
 381         usleep(500000);
 382         goto repeat;
 383 }
 384
 385 /* sb */
 386 int com_sb(int fd, int argc, char **argv)
 387 {
 388         char *sb;
 389         int ret, nr = -1;       /* status bar will be printed that many
 390                                  * times. Negative value means: print
 391                                  * forever
 392                                  */
 393         if (argc > 1)
 394                 nr = atoi(argv[1]);
 395         while (nr) {
 396                 mmd_lock();
 397                 sb = get_sb_string(mmd);
 398                 mmd_unlock();
 399                 ret = send_va_buffer(fd, "%s\n", sb);
 400                 free(sb);
 401                 if (ret < 0)
 402                         return ret;
 403                 if (nr == 1)
 404                         return 1;
 405                 usleep(500000);
 406                 if (nr > 0)
 407                         nr--;
 408         }
 409         return 1;
 410 }
 411
 412 /* stat */
 413 int com_stat(int fd, int argc, char **argv)
 414 {
 415         int ret, num = 0;/* status will be printed that many
 416                           * times. num <= 0 means: print forever
 417                           */
 418         struct misc_meta_data tmp, *nmmd = &tmp;
 419         char *s;
 420
 421         signal(SIGUSR1, dummy);
 422
 423         if (argc > 1)
 424                 num = atoi(argv[1]);
 425         for (;;) {
 426
 427                 mmd_dup(nmmd);
 428                 s = get_status(nmmd);
 429                 ret = send_buffer(fd, s);
 430                 free(s);
 431                 if (ret < 0)
 432                         goto out;
 433                 ret = 1;
 434                 if (num == 1)
 435                         goto out;
 436                 sleep(50);
 437                 if (getppid() == 1)
 438                         return -E_SERVER_CRASH;
 439         }
 440 out:
 441         return ret;
 442 }
 443
 444 static int send_list_of_commands(int fd, struct server_command *cmd,
 445                 const char *handler)
 446 {
 447         int ret, i;
 448
 449         for (i = 1; cmd->name; cmd++, i++) {
 450                 char *perms = cmd_perms_itohuman(cmd->perms);
 451                 ret = send_va_buffer(fd, "%s\t%s\t%s\t%s\n", cmd->name,
 452                         handler,
 453                         perms,
 454                         cmd->description);
 455                 free(perms);
 456                 if (ret < 0)
 457                         return ret;
 458         }
 459         return 1;
 460 }
 461
 462 /* always returns string that must be freed by the caller in handler */
 463 static struct server_command *get_cmd_ptr(char *name, char **handler)
 464 {
 465         struct server_command *cmd;
 466
 467         for (cmd = server_cmds; cmd->name; cmd++)
 468                 if (!strcmp(cmd->name, name)) {
 469                         if (handler)
 470                                 *handler = para_strdup("para_server"); /* server commands */
 471                         return cmd;
 472                 }
 473         /* not found, look for commands supported by the current selector */
 474         mmd_lock();
 475         if (handler)
 476                 *handler = make_message("the %s selector",
 477                         selectors[mmd->selector_num].name);
 478         cmd = selectors[mmd->selector_num].cmd_list;
 479         mmd_unlock();
 480         for (; cmd->name; cmd++)
 481                 if (!strcmp(cmd->name, name))
 482                         return cmd;
 483         return NULL;
 484 }
 485
 486 /* help */
 487 int com_help(int fd, int argc, char **argv)
 488 {
 489         struct server_command *cmd;
 490         char *perms, *handler;
 491         int ret;
 492
 493         if (argc < 2) {
 494                 /* no argument given, print list of commands */
 495                 if ((ret = send_list_of_commands(fd, server_cmds, "server")) < 0)
 496                         return ret;
 497                 mmd_lock();
 498                 handler = para_strdup(selectors[mmd->selector_num].name);
 499                 cmd = selectors[mmd->selector_num].cmd_list;
 500                 mmd_unlock();
 501                 ret = send_list_of_commands(fd, cmd, handler);
 502                 free(handler);
 503                 return ret;
 504         }
 505         /* argument given for help */
 506         cmd = get_cmd_ptr(argv[1], &handler);
 507         if (!cmd) {
 508                 free(handler);
 509                 return -E_BAD_CMD;
 510         }
 511         perms = cmd_perms_itohuman(cmd->perms);
 512         ret = send_va_buffer(fd,
 513                 "%s - %s\n\n"
 514                 "handler: %s\n"
 515                 "permissions: %s\n"
 516                 "usage: %s\n\n"
 517                 "%s\n",
 518                 argv[1],
 519                 cmd->description,
 520                 handler,
 521                 perms,
 522                 cmd->usage,
 523                 cmd->help
 524         );
 525         free(perms);
 526         free(handler);
 527         return ret;
 528 }
 529
 530 /* hup */
 531 int com_hup(__a_unused int fd, int argc, __a_unused char **argv)
 532 {
 533         if (argc != 1)
 534                 return -E_COMMAND_SYNTAX;
 535         kill(getppid(), SIGHUP);
 536         return 1;
 537 }
 538
 539 /* term */
 540 int com_term(__a_unused int fd, int argc, __a_unused char **argv)
 541 {
 542         if (argc != 1)
 543                 return -E_COMMAND_SYNTAX;
 544         kill(getppid(), SIGTERM);
 545         return 1;
 546 }
 547
 548 int com_play(__a_unused int fd, int argc, __a_unused char **argv)
 549 {
 550         if (argc != 1)
 551                 return -E_COMMAND_SYNTAX;
 552         mmd_lock();
 553         mmd->new_vss_status_flags |= VSS_PLAYING;
 554         mmd->new_vss_status_flags &= ~VSS_NOMORE;
 555         mmd_unlock();
 556         return 1;
 557
 558 }
 559
 560 /* stop */
 561 int com_stop(__a_unused int fd, int argc, __a_unused char **argv)
 562 {
 563         if (argc != 1)
 564                 return -E_COMMAND_SYNTAX;
 565         mmd_lock();
 566         mmd->new_vss_status_flags &= ~VSS_PLAYING;
 567         mmd->new_vss_status_flags &= ~VSS_REPOS;
 568         mmd->new_vss_status_flags |= VSS_NEXT;
 569         mmd_unlock();
 570         return 1;
 571 }
 572
 573 /* pause */
 574 int com_pause(__a_unused int fd, int argc, __a_unused char **argv)
 575 {
 576         if (argc != 1)
 577                 return -E_COMMAND_SYNTAX;
 578         mmd_lock();
 579         if (!vss_paused())
 580                 mmd->events++;
 581         mmd->new_vss_status_flags &= ~VSS_PLAYING;
 582         mmd->new_vss_status_flags &= ~VSS_NEXT;
 583         mmd_unlock();
 584         return 1;
 585 }
 586
 587 int com_chs(int fd, int argc, char **argv)
 588 {
 589         int i, ret;
 590
 591         if (argc == 1) {
 592                 char *selector;
 593                 mmd_lock();
 594                 selector = para_strdup(selectors[mmd->selector_num].name);
 595                 mmd_unlock();
 596                 ret = send_va_buffer(fd, "%s\n", selector);
 597                 free(selector);
 598                 return ret;
 599         }
 600         for (i = 0; selectors[i].name; i++) {
 601                 if (strcmp(selectors[i].name, argv[1]))
 602                         continue;
 603                 mmd_lock();
 604                 mmd->selector_change = i;
 605                 mmd->events++;
 606                 mmd_unlock();
 607                 return 1;
 608         }
 609         return -E_BAD_SELECTOR;
 610 }
 611
 612 /* next */
 613 int com_next(__a_unused int fd, int argc, __a_unused char **argv)
 614 {
 615         if (argc != 1)
 616                 return -E_COMMAND_SYNTAX;
 617         mmd_lock();
 618         mmd->events++;
 619         mmd->new_vss_status_flags |= VSS_NEXT;
 620         mmd_unlock();
 621         return 1;
 622 }
 623
 624 /* nomore */
 625 int com_nomore(__a_unused int fd, int argc, __a_unused char **argv)
 626 {
 627         if (argc != 1)
 628                 return -E_COMMAND_SYNTAX;
 629         mmd_lock();
 630         if (vss_playing() || vss_paused())
 631                 mmd->new_vss_status_flags |= VSS_NOMORE;
 632         mmd_unlock();
 633         return 1;
 634 }
 635
 636 /* ff */
 637 int com_ff(__a_unused int fd, int argc, char **argv)
 638 {
 639         long promille;
 640         int ret, backwards = 0;
 641         unsigned i;
 642         char c;
 643
 644         if (argc != 2)
 645                 return -E_COMMAND_SYNTAX;
 646         if (!(ret = sscanf(argv[1], "%u%c", &i, &c)))
 647                 return -E_COMMAND_SYNTAX;
 648         if (ret > 1 && c == '-')
 649                 backwards = 1; /* jmp backwards */
 650         mmd_lock();
 651         ret = -E_NO_AUDIO_FILE;
 652         if (!mmd->afi.chunks_total || !mmd->afi.seconds_total)
 653                 goto out;
 654         promille = (1000 * mmd->current_chunk) / mmd->afi.chunks_total;
 655         if (backwards)
 656                 promille -= 1000 * i / mmd->afi.seconds_total;
 657         else
 658                 promille += 1000 * i / mmd->afi.seconds_total;
 659         if (promille < 0)
 660                 promille = 0;
 661         if (promille >  1000) {
 662                 mmd->new_vss_status_flags |= VSS_NEXT;
 663                 goto out;
 664         }
 665         mmd->repos_request = (mmd->afi.chunks_total * promille) / 1000;
 666         mmd->new_vss_status_flags |= VSS_REPOS;
 667         mmd->new_vss_status_flags &= ~VSS_NEXT;
 668         mmd->events++;
 669         ret = 1;
 670 out:
 671         mmd_unlock();
 672         return ret;
 673 }
 674
 675 /* jmp */
 676 int com_jmp(__a_unused int fd, int argc, char **argv)
 677 {
 678         long unsigned int i;
 679         int ret;
 680
 681         if (argc != 2)
 682                 return -E_COMMAND_SYNTAX;
 683         if (sscanf(argv[1], "%lu", &i) <= 0)
 684                 return -E_COMMAND_SYNTAX;
 685         mmd_lock();
 686         ret = -E_NO_AUDIO_FILE;
 687         if (!mmd->afi.chunks_total)
 688                 goto out;
 689         if (i > 100)
 690                 i = 100;
 691         PARA_INFO_LOG("jumping to %lu%%\n", i);
 692         mmd->repos_request = (mmd->afi.chunks_total * i + 50)/ 100;
 693         PARA_INFO_LOG("sent: %lu,  offset before jmp: %lu\n",
 694                 mmd->chunks_sent, mmd->offset);
 695         mmd->new_vss_status_flags |= VSS_REPOS;
 696         mmd->new_vss_status_flags &= ~VSS_NEXT;
 697         ret = 1;
 698         mmd->events++;
 699 out:
 700         mmd_unlock();
 701         return ret;
 702 }
 703
 704 /*
 705  * check if perms are sufficient to exec a command having perms cmd_perms.
 706  * Returns 0 if perms are sufficient, -E_PERM otherwise.
 707  */
 708 static int check_perms(unsigned int perms, struct server_command *cmd_ptr)
 709 {
 710         PARA_DEBUG_LOG("%s", "checking permissions\n");
 711         return (cmd_ptr->perms & perms) < cmd_ptr->perms ? -E_PERM : 0;
 712 }
 713
 714 /*
 715  * Parse first string from *cmd and lookup in table of valid commands.
 716  * On error, NULL is returned.
 717  */
 718 static struct server_command *parse_cmd(const char *cmdstr)
 719 {
 720         char buf[255];
 721         int n = 0;
 722
 723         sscanf(cmdstr, "%200s%n", buf, &n);
 724         if (!n)
 725                 return NULL;
 726         buf[n] = '\0';
 727         return get_cmd_ptr(buf, NULL);
 728 }
 729
 730 static long int para_rand(long unsigned max)
 731 {
 732         return (long int) ((max + 0.0) * (random() / (RAND_MAX + 1.0)));
 733 }
 734
 735 static void init_rc4_keys(void)
 736 {
 737         int i;
 738
 739         for (i = 0; i < 2 * RC4_KEY_LEN; i++)
 740                 rc4_buf[i] = para_rand(256);
 741         PARA_DEBUG_LOG("rc4 keys initialized (%u:%u)\n",
 742                 (unsigned char) rc4_buf[0],
 743                 (unsigned char) rc4_buf[RC4_KEY_LEN]);
 744         RC4_set_key(&rc4_recv_key, RC4_KEY_LEN, rc4_buf);
 745         RC4_set_key(&rc4_send_key, RC4_KEY_LEN, rc4_buf + RC4_KEY_LEN);
 746 }
 747
 748 static void rc4_recv(unsigned long len, const unsigned char *indata,
 749                 unsigned char *outdata, __a_unused void *private_data)
 750 {
 751         RC4(&rc4_recv_key, len, indata, outdata);
 752 }
 753
 754 static void rc4_send(unsigned long len, const unsigned char *indata,
 755                 unsigned char *outdata, __a_unused void *private_data)
 756 {
 757         RC4(&rc4_send_key, len, indata, outdata);
 758 }
 759
 760 /**
 761  * perform user authentication and execute a command
 762  *
 763  * \param fd the file descriptor to send output to
 764  * \param addr socket address info of peer
 765  *
 766  * \return EXIT_SUCCESS or EXIT_FAILURE
 767  *
 768  * Whenever para_server accepts an incoming tcp connection on
 769  * the port it listens on, it forks and the resulting child
 770  * calls this function.
 771  *
 772  * An RSA-based challenge/response is used to authenticate
 773  * the peer. It that authentication succeeds, a random RC4
 774  * session key is generated and sent back to the peer,
 775  * encrypted with its RSA public key.  From this point on,
 776  * all transfers are crypted with this session key.
 777  *
 778  * Next it is checked if the peer supplied  a valid server
 779  * command or a command for the audio file selector currently
 780  * in use.  If yes, and if the user has sufficient
 781  * permissions to execute that command, the function calls
 782  * the corresponding command handler which does argument
 783  * checking and further processing.
 784  *
 785  * In order to cope with a DOS attacks, a timeout is set up
 786  * which terminates the function if the connection was not
 787  * authenticated when the timeout expires.
 788  *
 789  * \sa alarm(2), rc4(3), crypt.c, crypt.h
 790  */
 791 int handle_connect(int fd, struct sockaddr_in *addr)
 792 {
 793         int numbytes, ret, argc, use_rc4 = 0;
 794         char buf[4096];
 795         unsigned char crypt_buf[MAXLINE];
 796         struct user *u;
 797         struct server_command *cmd = NULL;
 798         long unsigned challenge_nr, chall_response;
 799         char **argv = NULL;
 800         char *p, *command = NULL;
 801
 802         signal(SIGCHLD, SIG_IGN);
 803         signal(SIGINT, SIG_DFL);
 804         signal(SIGTERM, SIG_DFL);
 805         signal(SIGHUP, SIG_DFL);
 806         signal(SIGUSR1, SIG_IGN);
 807
 808         challenge_nr = random();
 809         /* send Welcome message */
 810         ret = send_va_buffer(fd, "This is para_server, version "
 811                 PACKAGE_VERSION  ".\n" );
 812         if (ret < 0)
 813                 goto err_out;
 814         /* recv auth request line */
 815         ret = recv_buffer(fd, buf, sizeof(buf));
 816         if (ret < 0)
 817                 goto err_out;
 818         if (ret <= 6) {
 819                 ret = -E_AUTH;
 820                 goto err_out;
 821         }
 822         numbytes = ret;
 823         ret = -E_AUTH;
 824         if (strncmp(buf, "auth ", 5))
 825                 goto err_out;
 826
 827         if (numbytes < 9 || strncmp(buf, "auth rc4 ", 9))
 828                 p = buf + 5; /* client version < 0.2.6 */
 829         else {
 830                 p = buf + 9; /* client version >= 0.2.6 */
 831                 use_rc4 = 1;
 832         }
 833         PARA_DEBUG_LOG("received %s request for user %s\n",
 834                 use_rc4? "rc4" : "auth", p);
 835         ret = -E_BAD_USER;
 836         u = lookup_user(p);
 837         if (!u)
 838                 goto err_out;
 839         ret = para_encrypt_challenge(u->rsa, challenge_nr, crypt_buf);
 840         if (ret <= 0)
 841                 goto err_out;
 842         numbytes = ret;
 843         PARA_DEBUG_LOG("sending %d byte challenge\n", numbytes);
 844         /* We can't use send_buffer here since buf may contain null bytes */
 845         ret = send_bin_buffer(fd,(char *) crypt_buf, numbytes);
 846         if (ret < 0)
 847                 goto err_out;
 848         /* recv decrypted number */
 849         numbytes = recv_buffer(fd, buf, sizeof(buf));
 850         ret = numbytes;
 851         if (ret < 0)
 852                 goto err_out;
 853         ret = -E_AUTH;
 854         if (!numbytes)
 855                 goto err_out;
 856         if (sscanf(buf, CHALLENGE_RESPONSE_MSG "%lu", &chall_response) < 1
 857                         || chall_response != challenge_nr)
 858                 goto err_out;
 859         /* auth successful. Send 'Proceed' message */
 860         PARA_INFO_LOG("good auth for %s (%lu)\n", u->name, challenge_nr);
 861         sprintf(buf, "%s", PROCEED_MSG);
 862         if (use_rc4) {
 863                 init_rc4_keys();
 864                 ret = para_encrypt_buffer(u->rsa, rc4_buf, 2 * RC4_KEY_LEN,
 865                         (unsigned char *)buf + PROCEED_MSG_LEN + 1);
 866                 if (ret <= 0)
 867                         goto err_out;
 868                 numbytes = ret + strlen(PROCEED_MSG) + 1;
 869         } else
 870                 numbytes = strlen(buf);
 871         ret = send_bin_buffer(fd, buf, numbytes);
 872         if (ret < 0)
 873                 goto err_out;
 874         if (use_rc4)
 875                 enable_crypt(fd, rc4_recv, rc4_send, NULL);
 876         /* read command */
 877         while ((numbytes = recv_buffer(fd, buf, sizeof(buf))) > 0) {
 878 //              PARA_INFO_LOG("recvd: %s (%d)\n", buf, numbytes);
 879                 ret = -E_COMMAND_SYNTAX;
 880                 if (command && numbytes + strlen(command) > MAX_COMMAND_LEN) /* DOS */
 881                         goto err_out;
 882                 command = para_strcat(command, buf);
 883                 if ((p = strstr(command, EOC_MSG))) {
 884                         *p = '\0';
 885                         break;
 886                 }
 887         }
 888         ret = numbytes;
 889         if (ret < 0)
 890                 goto err_out;
 891         ret = -E_BAD_CMD;
 892         /* parse command */
 893         if (!(cmd = parse_cmd(command)))
 894                 goto err_out;
 895         /* valid command, check permissions */
 896         ret = check_perms(u->perms, cmd);
 897         if (ret < 0)
 898                 goto err_out;
 899         /* valid command and sufficient perms */
 900         alarm(0);
 901         argc = split_args(command, &argv, "\n");
 902         mmd_lock();
 903         mmd->num_commands++;
 904         mmd_unlock();
 905         PARA_NOTICE_LOG("calling com_%s() for %s@%s\n", cmd->name, u->name,
 906                 inet_ntoa(addr->sin_addr));
 907         ret = cmd->handler(fd, argc, argv);
 908         if (ret >= 0) {
 909                 ret = EXIT_SUCCESS;
 910                 goto out;
 911         }
 912 err_out:
 913         if (ret != -E_SEND && ret != -E_RECV) {
 914                 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-ret));
 915                 send_va_buffer(fd, "%s\n", PARA_STRERROR(-ret));
 916         }
 917         ret = EXIT_FAILURE;
 918 out:
 919         free(command);
 920         free(argv);
 921         mmd_lock();
 922         if (cmd && (cmd->perms & AFS_WRITE) && ret >= 0)
 923                 mmd->events++;
 924         mmd->active_connections--;
 925         mmd_unlock();
 926         return ret;
 927 }