server/mr_main.c

   1 /*
   2  *      $Source$
   3  *      $Author$
   4  *      $Header$
   5  *
   6  *      Copyright (C) 1987 by the Massachusetts Institute of Technology
   7  *      For copying and distribution information, please see the file
   8  *      <mit-copyright.h>.
   9  *
  10  *      MOIRA server process.
  11  *
  12  *      Most of this is stolen from ../gdb/tsr.c
  13  *
  14  *      You are in a maze of twisty little finite automata, all different.
  15  *      Let the reader beware.
  16  *
  17  */
  18
  19 static char *rcsid_mr_main_c = "$Header$";
  20
  21 #include <mit-copyright.h>
  22 #include <strings.h>
  23 #include <sys/types.h>
  24 #include <sys/errno.h>
  25 #include <sys/signal.h>
  26 #include <sys/wait.h>
  27 #include <sys/stat.h>
  28 #include "mr_server.h"
  29 #include <krb_et.h>
  30
  31 extern CONNECTION newconn, listencon;
  32
  33 extern int nclients;
  34 extern client **clients, *cur_client;
  35
  36 extern OPERATION listenop;
  37 extern LIST_OF_OPERATIONS op_list;
  38
  39 extern struct sockaddr_in client_addr;
  40 extern int client_addrlen;
  41 extern TUPLE client_tuple;
  42
  43 extern char *whoami;
  44 extern char buf1[BUFSIZ];
  45 extern char *takedown;
  46 extern int errno;
  47 extern FILE *journal;
  48
  49 extern char *inet_ntoa();
  50 extern void mr_com_err();
  51 extern void do_client();
  52
  53 extern int sigshut();
  54 void clist_append();
  55 void oplist_append();
  56 void reapchild(), godormant(), gowakeup();
  57
  58 extern time_t now;
  59
  60 #ifdef _DEBUG_MALLOC_INC
  61 static char *dbg_malloc();
  62 static int dbg_free();
  63 #endif
  64
  65 /*
  66  * Main MOIRA server loop.
  67  *
  68  * Initialize the world, then start accepting connections and
  69  * making progress on current connections.
  70  */
  71
  72 /*ARGSUSED*/
  73 int
  74 main(argc, argv)
  75         int argc;
  76         char **argv;
  77 {
  78         int status, i;
  79         time_t tardy;
  80         char *port;
  81         extern char *database;
  82         struct stat stbuf;
  83
  84         whoami = argv[0];
  85         /*
  86          * Error handler init.
  87          */
  88         initialize_sms_error_table();
  89         initialize_krb_error_table();
  90         initialize_gdss_error_table();
  91         set_com_err_hook(mr_com_err);
  92         setlinebuf(stderr);
  93
  94         database = "moira";
  95         port = index(MOIRA_SERVER, ':') + 1;
  96
  97         for (i = 1; i < argc; i++) {
  98             if (!strcmp(argv[i], "-db") && i+1 < argc) {
  99                 database = argv[i+1];
 100                 i++;
 101             } else if (!strcmp(argv[i], "-p") && i+1 < argc) {
 102                 port = argv[i+1];
 103                 i++;
 104             } else {
 105                 com_err(whoami, 0, "Usage: moirad [-db database][-p port]");
 106                 exit(1);
 107             }
 108         }
 109
 110         /* Profiling implies that getting rid of one level of call
 111          * indirection here wins us maybe 1% on the VAX.
 112          */
 113 #ifdef _DEBUG_MALLOC_INC
 114         gdb_amv = dbg_malloc;
 115         gdb_fmv = dbg_free;
 116 #else
 117         gdb_amv = malloc;
 118         gdb_fmv = (int (*)()) free;
 119 #endif
 120
 121         /*
 122          * GDB initialization.
 123          */
 124         if(gdb_init() != 0) {
 125                 com_err(whoami, 0, "GDB initialization failed.");
 126                 exit(1);
 127         }
 128         gdb_debug(0); /* this can be patched, if necessary, to enable */
 129                       /* GDB level debugging .. */
 130         krb_realm = malloc(REALM_SZ);
 131         krb_get_lrealm(krb_realm, 1);
 132
 133         /*
 134          * Database initialization.  Only init if database should be open.
 135          */
 136
 137         if (stat(MOIRA_MOTD_FILE, &stbuf) != 0) {
 138             if ((status = mr_open_database()) != 0) {
 139                 com_err(whoami, status, " when trying to open database.");
 140                 exit(1);
 141             }
 142             sanity_check_database();
 143         } else {
 144             dormant = ASLEEP;
 145             com_err(whoami, 0, "sleeping, not opening database");
 146         }
 147
 148         sanity_check_queries();
 149
 150         /*
 151          * Set up client array handler.
 152          */
 153         nclients = 0;
 154         clients = (client **) malloc(0);
 155
 156         mr_setup_signals();
 157
 158         journal = fopen(JOURNAL, "a");
 159         if (journal == NULL) {
 160             com_err(whoami, errno, " while opening journal file");
 161             exit(1);
 162         }
 163
 164         /*
 165          * Establish template connection.
 166          */
 167         if ((status = do_listen(port)) != 0) {
 168                 com_err(whoami, status,
 169                         " while trying to create listening connection");
 170                 exit(1);
 171         }
 172
 173         op_list = create_list_of_operations(1, listenop);
 174
 175         com_err(whoami, 0, "started (pid %d)", getpid());
 176         com_err(whoami, 0, rcsid_mr_main_c);
 177         if (dormant != ASLEEP)
 178           send_zgram("MOIRA", "server started");
 179         else
 180           send_zgram("MOIRA", "server started, but database closed");
 181
 182         /*
 183          * Run until shut down.
 184          */
 185         while(!takedown) {
 186                 register int i;
 187                 /*
 188                  * Block until something happens.
 189                  */
 190 #ifdef notdef
 191                 com_err(whoami, 0, "tick");
 192 #endif notdef
 193                 if (dormant == SLEEPY) {
 194                     mr_close_database();
 195                     com_err(whoami, 0, "database closed");
 196                     mr_setup_signals();
 197                     send_zgram("MOIRA", "database closed");
 198                     dormant = ASLEEP;
 199                 } else if (dormant == GROGGY) {
 200                     mr_open_database();
 201                     com_err(whoami, 0, "database open");
 202                     mr_setup_signals();
 203                     send_zgram("MOIRA", "database open again");
 204                     dormant = AWAKE;
 205                 }
 206
 207                 errno = 0;
 208                 status = op_select_any(op_list, 0,
 209                                        (fd_set *)NULL, (fd_set *)NULL,
 210                                        (fd_set *)NULL, (struct timeval *)NULL);
 211
 212                 if (status == -1) {
 213                         if (errno != EINTR)
 214                           com_err(whoami, errno, " error from op_select");
 215                         if (!inc_running || now - inc_started > INC_TIMEOUT)
 216                           next_incremental();
 217                         continue;
 218                 } else if (status != -2) {
 219                         com_err(whoami, 0, " wrong return from op_select_any");
 220                         continue;
 221                 }
 222                 if (takedown) break;
 223                 time(&now);
 224                 if (!inc_running || now - inc_started > INC_TIMEOUT)
 225                   next_incremental();
 226 #ifdef notdef
 227                 fprintf(stderr, "    tick\n");
 228 #endif notdef
 229                 /*
 230                  * Handle any new connections; this comes first so
 231                  * errno isn't tromped on.
 232                  */
 233                 if (OP_DONE(listenop)) {
 234                         if (OP_STATUS(listenop) == OP_CANCELLED) {
 235                                 if (errno == EWOULDBLOCK) {
 236                                         do_reset_listen();
 237                                 } else {
 238                                         static int count = 0;
 239                                         com_err(whoami, errno,
 240                                                 " error (%d) on listen", count);
 241                                         if (count++ > 10)
 242                                           exit(1);
 243                                 }
 244                         } else if ((status = new_connection()) != 0) {
 245                                 com_err(whoami, errno,
 246                                         " Error on listening operation.");
 247                                 /*
 248                                  * Sleep here to prevent hosing?
 249                                  */
 250                         }
 251                         /* if the new connection is our only connection,
 252                          * and the server is supposed to be down, then go
 253                          * down now.
 254                          */
 255                         if ((dormant == AWAKE) && (nclients == 1) &&
 256                             (stat(MOIRA_MOTD_FILE, &stbuf) == 0)) {
 257                             com_err(whoami, 0, "motd file exists, slumbertime");
 258                             dormant = SLEEPY;
 259                         }
 260                         /* on new connection, if we are no longer supposed
 261                          * to be down, then wake up.
 262                          */
 263                         if ((dormant == ASLEEP) &&
 264                             (stat(MOIRA_MOTD_FILE, &stbuf) == -1) &&
 265                             (errno == ENOENT)) {
 266                             com_err(whoami, 0, "motd file no longer exists, waking up");
 267                             dormant = GROGGY;
 268                         }
 269
 270                 }
 271                 /*
 272                  * Handle any existing connections.
 273                  */
 274                 tardy = now - 30*60;
 275
 276                 for (i=0; i<nclients; i++) {
 277                         cur_client = clients[i];
 278                         if (OP_DONE(clients[i]->pending_op)) {
 279                                 cur_client->last_time_used = now;
 280                                 do_client(cur_client);
 281                         } else if (clients[i]->last_time_used < tardy) {
 282                                 com_err(whoami, 0, "Shutting down connection due to inactivity");
 283                                 shutdown(cur_client->con->in.fd, 0);
 284                         }
 285                         cur_client = NULL;
 286                         if (takedown) break;
 287                 }
 288         }
 289         com_err(whoami, 0, "%s", takedown);
 290         mr_close_database();
 291         send_zgram("MOIRA", takedown);
 292         return 0;
 293 }
 294
 295 /*
 296  * Set up the template connection and queue the first accept.
 297  */
 298
 299 int
 300 do_listen(port)
 301 char *port;
 302 {
 303         listencon = create_listening_connection(port);
 304
 305         if (listencon == NULL)
 306                 return errno;
 307
 308         listenop = create_operation();
 309         client_addrlen = sizeof(client_addr);
 310
 311         start_accepting_client(listencon, listenop, &newconn,
 312                                (char *)&client_addr,
 313                                &client_addrlen, &client_tuple);
 314         return 0;
 315 }
 316
 317
 318 do_reset_listen()
 319 {
 320         client_addrlen = sizeof(client_addr);
 321         start_accepting_client(listencon, listenop, &newconn,
 322                                (char *)&client_addr,
 323                                &client_addrlen, &client_tuple);
 324 }
 325
 326 /*
 327  * This routine is called when a new connection comes in.
 328  *
 329  * It sets up a new client and adds it to the list of currently active clients.
 330  */
 331 int
 332 new_connection()
 333 {
 334         register client *cp;
 335         static counter = 0;
 336
 337         /*
 338          * Make sure there's been no error
 339          */
 340         if(OP_STATUS(listenop) != OP_COMPLETE) {
 341                 return errno;
 342         }
 343
 344         if (newconn == NULL) {
 345                 return MR_NOT_CONNECTED;
 346         }
 347
 348         /*
 349          * Set up the new connection and reply to the client
 350          */
 351         cp = (client *)malloc(sizeof *cp);
 352         bzero(cp, sizeof(*cp));
 353         cp->action = CL_ACCEPT;
 354         cp->con = newconn;
 355         cp->id = counter++;
 356         cp->args = NULL;
 357         cp->clname[0] = NULL;
 358         cp->reply.mr_argv = NULL;
 359         cp->first = NULL;
 360         cp->last = NULL;
 361         cp->last_time_used = now;
 362         newconn = NULL;
 363
 364         cp->pending_op = create_operation();
 365         reset_operation(cp->pending_op);
 366         oplist_append(&op_list, cp->pending_op);
 367         cur_client = cp;
 368
 369         /*
 370          * Add a new client to the array..
 371          */
 372         clist_append(cp);
 373
 374         /*
 375          * Let him know we heard him.
 376          */
 377         start_replying_to_client(cp->pending_op, cp->con, GDB_ACCEPTED,
 378                                  "", "");
 379
 380         cp->haddr = client_addr;
 381
 382         /*
 383          * Log new connection.
 384          */
 385
 386         com_err(whoami, 0, "New connection from %s port %d (now %d client%s)",
 387                 inet_ntoa(cp->haddr.sin_addr),
 388                 (int)ntohs(cp->haddr.sin_port),
 389                 nclients,
 390                 nclients!=1?"s":"");
 391
 392         /*
 393          * Get ready to accept the next connection.
 394          */
 395         reset_operation(listenop);
 396         client_addrlen = sizeof(client_addr);
 397
 398         start_accepting_client(listencon, listenop, &newconn,
 399                                (char *)&client_addr,
 400                                &client_addrlen, &client_tuple);
 401         return 0;
 402 }
 403
 404 /*
 405  * Add a new client to the known clients.
 406  */
 407 void
 408 clist_append(cp)
 409         client *cp;
 410 {
 411         client **clients_n;
 412
 413         nclients++;
 414         clients_n = (client **)malloc
 415                 ((unsigned)(nclients * sizeof(client *)));
 416         bcopy((char *)clients, (char *)clients_n, (nclients-1)*sizeof(cp));
 417         clients_n[nclients-1] = cp;
 418         free((char *)clients);
 419         clients = clients_n;
 420         clients_n = NULL;
 421 }
 422
 423
 424 void
 425 clist_delete(cp)
 426         client *cp;
 427 {
 428         client **clients_n, **scpp, **dcpp; /* source and dest client */
 429                                             /* ptr ptr */
 430
 431         int found_it = 0;
 432
 433         clients_n = (client **)malloc
 434                 ((unsigned)((nclients - 1)* sizeof(client *)));
 435         for (scpp = clients, dcpp = clients_n; scpp < clients+nclients; ) {
 436                 if (*scpp != cp) {
 437                         *dcpp++ = *scpp++;
 438                 } else {
 439                         scpp++;
 440                         if (found_it) abort();
 441                         found_it = 1;
 442                 }
 443         }
 444         --nclients;
 445         free((char *)clients);
 446         clients = clients_n;
 447         clients_n = NULL;
 448         oplist_delete(op_list, cp->pending_op);
 449         reset_operation(cp->pending_op);
 450         delete_operation(cp->pending_op);
 451         sever_connection(cp->con);
 452         free((char *)cp);
 453 }
 454
 455 /*
 456  * Add a new operation to a list of operations.
 457  *
 458  * This should be rewritten to use realloc instead, since in most
 459  * cases it won't have to copy the array.
 460  */
 461
 462 void
 463 oplist_append(oplp, op)
 464         LIST_OF_OPERATIONS *oplp;
 465         OPERATION op;
 466 {
 467         int count = (*oplp)->count+1;
 468         LIST_OF_OPERATIONS newlist = (LIST_OF_OPERATIONS)
 469                 db_alloc(size_of_list_of_operations(count));
 470         bcopy((char *)(*oplp), (char *)newlist,
 471               size_of_list_of_operations((*oplp)->count));
 472         newlist->count++;
 473         newlist->op[count-1] = op;
 474         db_free((char *)(*oplp), size_of_list_of_operations(count-1));
 475         (*oplp) = newlist;
 476 }
 477
 478
 479 oplist_delete(oplp, op)
 480         LIST_OF_OPERATIONS oplp;
 481         register OPERATION op;
 482 {
 483         register OPERATION *s;
 484         register int c;
 485
 486         for (s = oplp->op, c=oplp->count; c; --c, ++s) {
 487                 if (*s == op) {
 488                         while (c > 0) {
 489                                 *s = *(s+1);
 490                                 ++s;
 491                                 --c;
 492                         }
 493                         oplp->count--;
 494                         return;
 495                 }
 496         }
 497         abort();
 498 }
 499
 500
 501 void reapchild()
 502 {
 503     union wait status;
 504     int pid;
 505
 506     while ((pid = wait3(&status, WNOHANG, (struct rusage *)0)) > 0) {
 507         if (pid == inc_pid)
 508           inc_running = 0;
 509         if  (!takedown && (status.w_termsig != 0 || status.w_retcode != 0))
 510           com_err(whoami, 0, "%d: child exits with signal %d status %d",
 511                   pid, status.w_termsig, status.w_retcode);
 512     }
 513 }
 514
 515
 516 void godormant()
 517 {
 518     switch (dormant) {
 519     case AWAKE:
 520     case GROGGY:
 521         com_err(whoami, 0, "requested to go dormant");
 522         break;
 523     case ASLEEP:
 524         com_err(whoami, 0, "already asleep");
 525         break;
 526     case SLEEPY:
 527         break;
 528     }
 529     dormant = SLEEPY;
 530 }
 531
 532
 533 void gowakeup()
 534 {
 535     switch (dormant) {
 536     case ASLEEP:
 537     case SLEEPY:
 538         com_err(whoami, 0, "Good morning");
 539         break;
 540     case AWAKE:
 541         com_err(whoami, 0, "already awake");
 542         break;
 543     case GROGGY:
 544         break;
 545     }
 546     dormant = GROGGY;
 547 }
 548
 549
 550 mr_setup_signals()
 551 {
 552     /* There should probably be a few more of these. */
 553
 554     if ((((int)signal (SIGTERM, sigshut)) < 0) ||
 555         (((int)signal (SIGCHLD, reapchild)) < 0) ||
 556         (((int)signal (SIGUSR1, godormant)) < 0) ||
 557         (((int)signal (SIGUSR2, gowakeup)) < 0) ||
 558         (((int)signal (SIGHUP, sigshut)) < 0)) {
 559         com_err(whoami, errno, " Unable to establish signal handlers.");
 560         exit(1);
 561     }
 562 }
 563
 564 #ifdef _DEBUG_MALLOC_INC
 565 static char *dbg_malloc(size)
 566         SIZETYPE        size;
 567 {
 568         return( debug_malloc("somewhere in the gdb code",1,size) );
 569 }
 570
 571 static int dbg_free(cptr)
 572         DATATYPE        *cptr;
 573 {
 574         debug_free((char *)NULL, 0, cptr);
 575         return 0;               /* GDB is being stupid */
 576 }
 577 #endif
 578