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