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