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