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 <string.h>
  23 #include <stdio.h>
  24 #include <sys/types.h>
  25 #include <sys/errno.h>
  26 #include <sys/signal.h>
  27 #include <sys/wait.h>
  28 #include <sys/stat.h>
  29 #include <unistd.h>
  30 #include <signal.h>
  31 #include "mr_server.h"
  32 #include <krb_et.h>
  33 #include <gdss_et.h>
  34 #include <arpa/inet.h>
  35
  36 extern CONNECTION newconn, listencon;
  37
  38 extern int nclients;
  39 extern client **clients, *cur_client;
  40
  41 extern OPERATION listenop;
  42 extern LIST_OF_OPERATIONS op_list;
  43
  44 extern struct sockaddr_in client_addr;
  45 extern int client_addrlen;
  46 extern TUPLE client_tuple;
  47
  48 extern char *whoami;
  49 extern char buf1[BUFSIZ];
  50 extern char *takedown;
  51 extern int errno;
  52 extern FILE *journal;
  53
  54 extern time_t now;
  55
  56 char hostbuf[BUFSIZ], *host;
  57
  58 int do_listen(char *port);
  59 void do_reset_listen(void);
  60 void clist_append(client *cp);
  61 void oplist_append(LIST_OF_OPERATIONS *oplp, OPERATION op);
  62 void oplist_delete(LIST_OF_OPERATIONS oplp, OPERATION op);
  63 void mr_setup_signals(void);
  64 int new_connection(void);
  65
  66 /*
  67  * Main MOIRA server loop.
  68  *
  69  * Initialize the world, then start accepting connections and
  70  * making progress on current connections.
  71  */
  72
  73 /*ARGSUSED*/
  74 int main(argc, argv)
  75      int argc;
  76      char **argv;
  77 {
  78         int status, i;
  79         time_t tardy;
  80         char *port, *p;
  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         setvbuf(stderr, NULL, _IOLBF, BUFSIZ);
  93
  94         port = strchr(MOIRA_SERVER, ':') + 1;
  95
  96         for (i = 1; i < argc; i++) {
  97             if (!strcmp(argv[i], "-db") && i+1 < argc) {
  98                 database = argv[i+1];
  99                 i++;
 100             } else if (!strcmp(argv[i], "-p") && i+1 < argc) {
 101                 port = argv[i+1];
 102                 i++;
 103             } else {
 104                 com_err(whoami, 0, "Usage: moirad [-db database][-p port]");
 105                 exit(1);
 106             }
 107         }
 108
 109         /*
 110          * GDB initialization.
 111          */
 112         if(gdb_init() != 0) {
 113                 com_err(whoami, 0, "GDB initialization failed.");
 114                 exit(1);
 115         }
 116         gdb_debug(0); /* this can be patched, if necessary, to enable */
 117                       /* GDB level debugging .. */
 118         krb_realm = malloc(REALM_SZ);
 119         krb_get_lrealm(krb_realm, 1);
 120
 121         /*
 122          * Database initialization.  Only init if database should be open.
 123          */
 124
 125         if (stat(MOIRA_MOTD_FILE, &stbuf) != 0) {
 126             if ((status = mr_open_database()) != 0) {
 127                 com_err(whoami, status, " when trying to open database.");
 128                 exit(1);
 129             }
 130             sanity_check_database();
 131         } else {
 132             dormant = ASLEEP;
 133             com_err(whoami, 0, "sleeping, not opening database");
 134         }
 135
 136         sanity_check_queries();
 137
 138         /*
 139          * Get moira server hostname for authentication
 140          */
 141         if (gethostname(hostbuf, sizeof(hostbuf)) < 0) {
 142           com_err(whoami, errno, "Unable to get local hostname");
 143           exit(1);
 144         }
 145         host = canonicalize_hostname(strsave(hostbuf));
 146         for (p = host; *p && *p != '.'; p++)
 147           if (isupper(*p))
 148             *p = tolower(*p);
 149         *p = 0;
 150
 151         /*
 152          * Set up client array handler.
 153          */
 154         nclients = 0;
 155         clients = (client **) malloc(0);
 156
 157         mr_setup_signals();
 158
 159         journal = fopen(JOURNAL, "a");
 160         if (journal == NULL) {
 161             com_err(whoami, errno, " while opening journal file");
 162             exit(1);
 163         }
 164
 165         /*
 166          * Establish template connection.
 167          */
 168         if ((status = do_listen(port)) != 0) {
 169                 com_err(whoami, status,
 170                         " while trying to create listening connection");
 171                 exit(1);
 172         }
 173
 174         op_list = create_list_of_operations(1, listenop);
 175
 176         com_err(whoami, 0, "started (pid %d)", getpid());
 177         com_err(whoami, 0, rcsid_mr_main_c);
 178         if (dormant != ASLEEP)
 179           send_zgram("MOIRA", "server started");
 180         else
 181           send_zgram("MOIRA", "server started, but database closed");
 182
 183         /*
 184          * Run until shut down.
 185          */
 186         while(!takedown) {
 187                 register int i;
 188                 /*
 189                  * Block until something happens.
 190                  */
 191 #ifdef notdef
 192                 com_err(whoami, 0, "tick");
 193 #endif notdef
 194                 if (dormant == SLEEPY) {
 195                     mr_close_database();
 196                     com_err(whoami, 0, "database closed");
 197                     mr_setup_signals();
 198                     send_zgram("MOIRA", "database closed");
 199                     dormant = ASLEEP;
 200                 } else if (dormant == GROGGY) {
 201                     mr_open_database();
 202                     com_err(whoami, 0, "database open");
 203                     mr_setup_signals();
 204                     send_zgram("MOIRA", "database open again");
 205                     dormant = AWAKE;
 206                 }
 207
 208                 errno = 0;
 209                 status = op_select_any(op_list, 0,
 210                                        (fd_set *)NULL, (fd_set *)NULL,
 211                                        (fd_set *)NULL, (struct timeval *)NULL);
 212
 213                 if (status == -1) {
 214                         if (errno != EINTR)
 215                           com_err(whoami, errno, " error from op_select");
 216                         if (!inc_running || now - inc_started > INC_TIMEOUT)
 217                           next_incremental();
 218                         continue;
 219                 } else if (status != -2) {
 220                         com_err(whoami, 0, " wrong return from op_select_any");
 221                         continue;
 222                 }
 223                 if (takedown) break;
 224                 time(&now);
 225                 if (!inc_running || now - inc_started > INC_TIMEOUT)
 226                   next_incremental();
 227 #ifdef notdef
 228                 fprintf(stderr, "    tick\n");
 229 #endif notdef
 230                 /*
 231                  * Handle any new connections; this comes first so
 232                  * errno isn't tromped on.
 233                  */
 234                 if (OP_DONE(listenop)) {
 235                         if (OP_STATUS(listenop) == OP_CANCELLED) {
 236                                 if (errno == EWOULDBLOCK) {
 237                                         do_reset_listen();
 238                                 } else {
 239                                         static int count = 0;
 240                                         com_err(whoami, errno,
 241                                                 " error (%d) on listen", count);
 242                                         if (count++ > 10)
 243                                           exit(1);
 244                                 }
 245                         } else if ((status = new_connection()) != 0) {
 246                                 com_err(whoami, errno,
 247                                         " Error on listening operation.");
 248                                 /*
 249                                  * Sleep here to prevent hosing?
 250                                  */
 251                         }
 252                         /* if the new connection is our only connection,
 253                          * and the server is supposed to be down, then go
 254                          * down now.
 255                          */
 256                         if ((dormant == AWAKE) && (nclients == 1) &&
 257                             (stat(MOIRA_MOTD_FILE, &stbuf) == 0)) {
 258                             com_err(whoami, 0, "motd file exists, slumbertime");
 259                             dormant = SLEEPY;
 260                         }
 261                         /* on new connection, if we are no longer supposed
 262                          * to be down, then wake up.
 263                          */
 264                         if ((dormant == ASLEEP) &&
 265                             (stat(MOIRA_MOTD_FILE, &stbuf) == -1) &&
 266                             (errno == ENOENT)) {
 267                             com_err(whoami, 0, "motd file no longer exists, waking up");
 268                             dormant = GROGGY;
 269                         }
 270
 271                 }
 272                 /*
 273                  * Handle any existing connections.
 274                  */
 275                 tardy = now - 30*60;
 276
 277                 for (i=0; i<nclients; i++) {
 278                         cur_client = clients[i];
 279                         if (OP_DONE(clients[i]->pending_op)) {
 280                                 cur_client->last_time_used = now;
 281                                 do_client(cur_client);
 282                         } else if (clients[i]->last_time_used < tardy) {
 283                                 com_err(whoami, 0, "Shutting down connection due to inactivity");
 284                                 shutdown(cur_client->con->in.fd, 2);
 285                         }
 286                         cur_client = NULL;
 287                         if (takedown) break;
 288                 }
 289         }
 290         com_err(whoami, 0, "%s", takedown);
 291         mr_close_database();
 292         send_zgram("MOIRA", takedown);
 293         return 0;
 294 }
 295
 296 /*
 297  * Set up the template connection and queue the first accept.
 298  */
 299
 300 int 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 void do_reset_listen(void)
 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 new_connection(void)
 332 {
 333         register client *cp;
 334         static counter = 0;
 335
 336         /*
 337          * Make sure there's been no error
 338          */
 339         if(OP_STATUS(listenop) != OP_COMPLETE) {
 340                 return errno;
 341         }
 342
 343         if (newconn == NULL) {
 344                 return MR_NOT_CONNECTED;
 345         }
 346
 347         /*
 348          * Set up the new connection and reply to the client
 349          */
 350         cp = (client *)malloc(sizeof *cp);
 351         memset(cp, 0, sizeof(*cp));
 352         cp->action = CL_ACCEPT;
 353         cp->con = newconn;
 354         cp->id = counter++;
 355         cp->args = NULL;
 356         cp->clname[0] = NULL;
 357         cp->reply.mr_argv = NULL;
 358         cp->first = NULL;
 359         cp->last = NULL;
 360         cp->last_time_used = now;
 361         newconn = NULL;
 362
 363         cp->pending_op = create_operation();
 364         reset_operation(cp->pending_op);
 365         oplist_append(&op_list, cp->pending_op);
 366         cur_client = cp;
 367
 368         /*
 369          * Add a new client to the array..
 370          */
 371         clist_append(cp);
 372
 373         /*
 374          * Let him know we heard him.
 375          */
 376         start_replying_to_client(cp->pending_op, cp->con, GDB_ACCEPTED,
 377                                  "", "");
 378
 379         cp->haddr = client_addr;
 380
 381         /*
 382          * Log new connection.
 383          */
 384
 385         com_err(whoami, 0, "New connection from %s port %d (now %d client%s)",
 386                 inet_ntoa(cp->haddr.sin_addr),
 387                 (int)ntohs(cp->haddr.sin_port),
 388                 nclients,
 389                 nclients!=1?"s":"");
 390
 391         /*
 392          * Get ready to accept the next connection.
 393          */
 394         reset_operation(listenop);
 395         client_addrlen = sizeof(client_addr);
 396
 397         start_accepting_client(listencon, listenop, &newconn,
 398                                (char *)&client_addr,
 399                                &client_addrlen, &client_tuple);
 400         return 0;
 401 }
 402
 403 /*
 404  * Add a new client to the known clients.
 405  */
 406 void clist_append(cp)
 407      client *cp;
 408 {
 409         client **clients_n;
 410
 411         nclients++;
 412         clients_n = (client **)malloc
 413                 ((unsigned)(nclients * sizeof(client *)));
 414         memcpy((char *)clients_n, (char *)clients, (nclients-1)*sizeof(cp));
 415         clients_n[nclients-1] = cp;
 416         free((char *)clients);
 417         clients = clients_n;
 418         clients_n = NULL;
 419 }
 420
 421
 422 void clist_delete(cp)
 423      client *cp;
 424 {
 425         client **clients_n, **scpp, **dcpp; /* source and dest client */
 426                                             /* ptr ptr */
 427
 428         int found_it = 0;
 429
 430         clients_n = (client **)malloc
 431                 ((unsigned)((nclients - 1)* sizeof(client *)));
 432         for (scpp = clients, dcpp = clients_n; scpp < clients+nclients; ) {
 433                 if (*scpp != cp) {
 434                         *dcpp++ = *scpp++;
 435                 } else {
 436                         scpp++;
 437                         if (found_it) abort();
 438                         found_it = 1;
 439                 }
 440         }
 441         --nclients;
 442         free((char *)clients);
 443         clients = clients_n;
 444         clients_n = NULL;
 445         oplist_delete(op_list, cp->pending_op);
 446         reset_operation(cp->pending_op);
 447         delete_operation(cp->pending_op);
 448         sever_connection(cp->con);
 449         free((char *)cp);
 450 }
 451
 452 /*
 453  * Add a new operation to a list of operations.
 454  *
 455  * This should be rewritten to use realloc instead, since in most
 456  * cases it won't have to copy the array.
 457  */
 458
 459 void oplist_append(oplp, op)
 460      LIST_OF_OPERATIONS *oplp;
 461      OPERATION op;
 462 {
 463         int count = (*oplp)->count+1;
 464         LIST_OF_OPERATIONS newlist = (LIST_OF_OPERATIONS)
 465                 db_alloc(size_of_list_of_operations(count));
 466         memcpy((char *)newlist, (char *)(*oplp),
 467               size_of_list_of_operations((*oplp)->count));
 468         newlist->count++;
 469         newlist->op[count-1] = op;
 470         db_free((char *)(*oplp), size_of_list_of_operations(count-1));
 471         (*oplp) = newlist;
 472 }
 473
 474
 475 void oplist_delete(oplp, op)
 476      LIST_OF_OPERATIONS oplp;
 477      OPERATION op;
 478 {
 479         register OPERATION *s;
 480         register int c;
 481
 482         for (s = oplp->op, c=oplp->count; c; --c, ++s) {
 483                 if (*s == op) {
 484                         while (c > 0) {
 485                                 *s = *(s+1);
 486                                 ++s;
 487                                 --c;
 488                         }
 489                         oplp->count--;
 490                         return;
 491                 }
 492         }
 493         abort();
 494 }
 495
 496
 497 void reapchild(x)
 498      int x;
 499 {
 500     int status, pid;
 501
 502     while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {
 503 #ifdef INCR_DEBUG
 504         com_err(whoami, 0, "Reaping %d (inc_pid=%d, inc_running=%d)",
 505                 pid, inc_pid, inc_running);
 506 #endif
 507         if (pid == inc_pid)
 508           inc_running = 0;
 509         if  (!takedown && (WTERMSIG(status)!= 0 || WEXITSTATUS(status)!= 0))
 510           com_err(whoami, 0, "%d: child exits with signal %d status %d",
 511                   pid, WTERMSIG(status), WEXITSTATUS(status));
 512     }
 513 }
 514
 515
 516 void godormant(x)
 517      int x;
 518 {
 519     switch (dormant) {
 520     case AWAKE:
 521     case GROGGY:
 522         com_err(whoami, 0, "requested to go dormant");
 523         break;
 524     case ASLEEP:
 525         com_err(whoami, 0, "already asleep");
 526         break;
 527     case SLEEPY:
 528         break;
 529     }
 530     dormant = SLEEPY;
 531 }
 532
 533
 534 void gowakeup(x)
 535      int x;
 536 {
 537     switch (dormant) {
 538     case ASLEEP:
 539     case SLEEPY:
 540         com_err(whoami, 0, "Good morning");
 541         break;
 542     case AWAKE:
 543         com_err(whoami, 0, "already awake");
 544         break;
 545     case GROGGY:
 546         break;
 547     }
 548     dormant = GROGGY;
 549 }
 550
 551
 552 void mr_setup_signals(void)
 553 {
 554     struct sigaction action;
 555
 556     action.sa_flags = 0;
 557     sigemptyset(&action.sa_mask);
 558
 559     /* There should probably be a few more of these. */
 560
 561     action.sa_handler = sigshut;
 562     if ((sigaction(SIGTERM, &action, NULL) < 0) ||
 563         (sigaction(SIGINT, &action, NULL) < 0) ||
 564         (sigaction(SIGHUP, &action, NULL) < 0)) {
 565       com_err(whoami, errno, "Unable to establish signal handlers.");
 566       exit(1);
 567     }
 568
 569     action.sa_handler = godormant;
 570     if (sigaction(SIGUSR1, &action, NULL) < 0) {
 571       com_err(whoami, errno, "Unable to establish signal handlers.");
 572       exit(1);
 573     }
 574
 575     action.sa_handler = gowakeup;
 576     if (sigaction(SIGUSR2, &action, NULL) < 0) {
 577       com_err(whoami, errno, "Unable to establish signal handlers.");
 578       exit(1);
 579     }
 580
 581     action.sa_handler = reapchild;
 582     sigaddset(&action.sa_mask, SIGCHLD);
 583     if (sigaction(SIGCHLD, &action, NULL) < 0) {
 584       com_err(whoami, errno, "Unable to establish signal handlers.");
 585       exit(1);
 586     }
 587 }