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                                         static int count = 0;
 217                                         com_err(whoami, errno,
 218                                                 " error (%d) on listen", count);
 219                                         if (count++ > 10)
 220                                           exit(1);
 221                                 }
 222                         } else if ((status = new_connection()) != 0) {
 223                                 com_err(whoami, errno,
 224                                         " Error on listening operation.");
 225                                 /*
 226                                  * Sleep here to prevent hosing?
 227                                  */
 228                         }
 229                         /* if the new connection is our only connection,
 230                          * and the server is supposed to be down, then go
 231                          * down now.
 232                          */
 233                         if ((dormant == AWAKE) && (nclients == 1) &&
 234                             (stat(MOIRA_MOTD_FILE, &stbuf) == 0)) {
 235                             com_err(whoami, 0, "motd file exists, slumbertime");
 236                             dormant = SLEEPY;
 237                         }
 238                         /* on new connection, if we are no longer supposed
 239                          * to be down, then wake up.
 240                          */
 241                         if ((dormant == ASLEEP) &&
 242                             (stat(MOIRA_MOTD_FILE, &stbuf) == -1) &&
 243                             (errno == ENOENT)) {
 244                             com_err(whoami, 0, "motd file no longer exists, waking up");
 245                             dormant = GROGGY;
 246                         }
 247
 248                 }
 249                 /*
 250                  * Handle any existing connections.
 251                  */
 252                 tardy = now - 30*60;
 253
 254                 for (i=0; i<nclients; i++) {
 255                         cur_client = clients[i];
 256                         if (OP_DONE(clients[i]->pending_op)) {
 257                                 cur_client->last_time_used = now;
 258                                 do_client(cur_client);
 259                         } else if (clients[i]->last_time_used < tardy) {
 260                                 com_err(whoami, 0, "Shutting down connection due to inactivity");
 261                                 shutdown(cur_client->con->in.fd, 0);
 262                         }
 263                         cur_client = NULL;
 264                         if (takedown) break;
 265                 }
 266         }
 267         com_err(whoami, 0, "%s", takedown);
 268         mr_close_database();
 269         send_zgram("MOIRA", takedown);
 270         return 0;
 271 }
 272
 273 /*
 274  * Set up the template connection and queue the first accept.
 275  */
 276
 277 int
 278 do_listen()
 279 {
 280         char *service = index(MOIRA_SERVER, ':') + 1;
 281
 282         listencon = create_listening_connection(service);
 283
 284         if (listencon == NULL)
 285                 return errno;
 286
 287         listenop = create_operation();
 288         client_addrlen = sizeof(client_addr);
 289
 290         start_accepting_client(listencon, listenop, &newconn,
 291                                (char *)&client_addr,
 292                                &client_addrlen, &client_tuple);
 293         return 0;
 294 }
 295
 296
 297 do_reset_listen()
 298 {
 299         client_addrlen = sizeof(client_addr);
 300         start_accepting_client(listencon, listenop, &newconn,
 301                                (char *)&client_addr,
 302                                &client_addrlen, &client_tuple);
 303 }
 304
 305 /*
 306  * This routine is called when a new connection comes in.
 307  *
 308  * It sets up a new client and adds it to the list of currently active clients.
 309  */
 310 int
 311 new_connection()
 312 {
 313         register client *cp;
 314         static counter = 0;
 315
 316         /*
 317          * Make sure there's been no error
 318          */
 319         if(OP_STATUS(listenop) != OP_COMPLETE) {
 320                 return errno;
 321         }
 322
 323         if (newconn == NULL) {
 324                 return MR_NOT_CONNECTED;
 325         }
 326
 327         /*
 328          * Set up the new connection and reply to the client
 329          */
 330         cp = (client *)malloc(sizeof *cp);
 331         bzero(cp, sizeof(*cp));
 332         cp->action = CL_ACCEPT;
 333         cp->con = newconn;
 334         cp->id = counter++;
 335         cp->args = NULL;
 336         cp->clname[0] = NULL;
 337         cp->reply.mr_argv = NULL;
 338         cp->first = NULL;
 339         cp->last = NULL;
 340         cp->last_time_used = now;
 341         newconn = NULL;
 342
 343         cp->pending_op = create_operation();
 344         reset_operation(cp->pending_op);
 345         oplist_append(&op_list, cp->pending_op);
 346         cur_client = cp;
 347
 348         /*
 349          * Add a new client to the array..
 350          */
 351         clist_append(cp);
 352
 353         /*
 354          * Let him know we heard him.
 355          */
 356         start_replying_to_client(cp->pending_op, cp->con, GDB_ACCEPTED,
 357                                  "", "");
 358
 359         cp->haddr = client_addr;
 360
 361         /*
 362          * Log new connection.
 363          */
 364
 365         com_err(whoami, 0, "New connection from %s port %d (now %d client%s)",
 366                 inet_ntoa(cp->haddr.sin_addr),
 367                 (int)ntohs(cp->haddr.sin_port),
 368                 nclients,
 369                 nclients!=1?"s":"");
 370
 371         /*
 372          * Get ready to accept the next connection.
 373          */
 374         reset_operation(listenop);
 375         client_addrlen = sizeof(client_addr);
 376
 377         start_accepting_client(listencon, listenop, &newconn,
 378                                (char *)&client_addr,
 379                                &client_addrlen, &client_tuple);
 380         return 0;
 381 }
 382
 383 /*
 384  * Add a new client to the known clients.
 385  */
 386 void
 387 clist_append(cp)
 388         client *cp;
 389 {
 390         client **clients_n;
 391
 392         nclients++;
 393         clients_n = (client **)malloc
 394                 ((unsigned)(nclients * sizeof(client *)));
 395         bcopy((char *)clients, (char *)clients_n, (nclients-1)*sizeof(cp));
 396         clients_n[nclients-1] = cp;
 397         free((char *)clients);
 398         clients = clients_n;
 399         clients_n = NULL;
 400 }
 401
 402
 403 void
 404 clist_delete(cp)
 405         client *cp;
 406 {
 407         client **clients_n, **scpp, **dcpp; /* source and dest client */
 408                                             /* ptr ptr */
 409
 410         int found_it = 0;
 411
 412         clients_n = (client **)malloc
 413                 ((unsigned)((nclients - 1)* sizeof(client *)));
 414         for (scpp = clients, dcpp = clients_n; scpp < clients+nclients; ) {
 415                 if (*scpp != cp) {
 416                         *dcpp++ = *scpp++;
 417                 } else {
 418                         scpp++;
 419                         if (found_it) abort();
 420                         found_it = 1;
 421                 }
 422         }
 423         --nclients;
 424         free((char *)clients);
 425         clients = clients_n;
 426         clients_n = NULL;
 427         oplist_delete(op_list, cp->pending_op);
 428         reset_operation(cp->pending_op);
 429         delete_operation(cp->pending_op);
 430         sever_connection(cp->con);
 431         free((char *)cp);
 432 }
 433
 434 /*
 435  * Add a new operation to a list of operations.
 436  *
 437  * This should be rewritten to use realloc instead, since in most
 438  * cases it won't have to copy the array.
 439  */
 440
 441 void
 442 oplist_append(oplp, op)
 443         LIST_OF_OPERATIONS *oplp;
 444         OPERATION op;
 445 {
 446         int count = (*oplp)->count+1;
 447         LIST_OF_OPERATIONS newlist = (LIST_OF_OPERATIONS)
 448                 db_alloc(size_of_list_of_operations(count));
 449         bcopy((char *)(*oplp), (char *)newlist,
 450               size_of_list_of_operations((*oplp)->count));
 451         newlist->count++;
 452         newlist->op[count-1] = op;
 453         db_free((char *)(*oplp), size_of_list_of_operations(count-1));
 454         (*oplp) = newlist;
 455 }
 456
 457
 458 oplist_delete(oplp, op)
 459         LIST_OF_OPERATIONS oplp;
 460         register OPERATION op;
 461 {
 462         register OPERATION *s;
 463         register int c;
 464
 465         for (s = oplp->op, c=oplp->count; c; --c, ++s) {
 466                 if (*s == op) {
 467                         while (c > 0) {
 468                                 *s = *(s+1);
 469                                 ++s;
 470                                 --c;
 471                         }
 472                         oplp->count--;
 473                         return;
 474                 }
 475         }
 476         abort();
 477 }
 478
 479
 480 void reapchild()
 481 {
 482     union wait status;
 483     int pid;
 484
 485     while ((pid = wait3(&status, WNOHANG, (struct rusage *)0)) > 0) {
 486         if (pid == inc_pid)
 487           inc_running = 0;
 488         if  (!takedown && (status.w_termsig != 0 || status.w_retcode != 0))
 489           com_err(whoami, 0, "%d: child exits with signal %d status %d",
 490                   pid, status.w_termsig, status.w_retcode);
 491     }
 492 }
 493
 494
 495 void godormant()
 496 {
 497     switch (dormant) {
 498     case AWAKE:
 499     case GROGGY:
 500         com_err(whoami, 0, "requested to go dormant");
 501         break;
 502     case ASLEEP:
 503         com_err(whoami, 0, "already asleep");
 504         break;
 505     case SLEEPY:
 506         break;
 507     }
 508     dormant = SLEEPY;
 509 }
 510
 511
 512 void gowakeup()
 513 {
 514     switch (dormant) {
 515     case ASLEEP:
 516     case SLEEPY:
 517         com_err(whoami, 0, "Good morning");
 518         break;
 519     case AWAKE:
 520         com_err(whoami, 0, "already awake");
 521         break;
 522     case GROGGY:
 523         break;
 524     }
 525     dormant = GROGGY;
 526 }
 527
 528
 529 mr_setup_signals()
 530 {
 531     /* There should probably be a few more of these. */
 532
 533     if ((((int)signal (SIGTERM, sigshut)) < 0) ||
 534         (((int)signal (SIGCHLD, reapchild)) < 0) ||
 535         (((int)signal (SIGUSR1, godormant)) < 0) ||
 536         (((int)signal (SIGUSR2, gowakeup)) < 0) ||
 537         (((int)signal (SIGHUP, sigshut)) < 0)) {
 538         com_err(whoami, errno, " Unable to establish signal handlers.");
 539         exit(1);
 540     }
 541 }