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  *      SMS 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_sms_main_c = "$Header$";
  20
  21 #include <mit-copyright.h>
  22 #include <strings.h>
  23 #include <sys/errno.h>
  24 #include <sys/signal.h>
  25 #include <sys/wait.h>
  26 #include "sms_server.h"
  27
  28 extern CONNECTION newconn, listencon;
  29
  30 extern int nclients;
  31 extern client **clients, *cur_client;
  32
  33 extern OPERATION listenop;
  34 extern LIST_OF_OPERATIONS op_list;
  35
  36 extern struct sockaddr_in client_addr;
  37 extern int client_addrlen;
  38 extern TUPLE client_tuple;
  39
  40 extern char *whoami;
  41 extern char buf1[BUFSIZ];
  42 extern char *takedown;
  43 extern int errno;
  44 extern FILE *journal;
  45 #define JOURNAL "/u1/sms/journal"
  46
  47 extern char *malloc();
  48 extern int free();
  49 extern char *inet_ntoa();
  50 extern void sms_com_err();
  51 extern void do_client();
  52
  53 extern int sigshut();
  54 void clist_append();
  55 void oplist_append();
  56 void reapchild();
  57
  58 extern time_t now;
  59
  60 /*
  61  * Main SMS server loop.
  62  *
  63  * Initialize the world, then start accepting connections and
  64  * making progress on current connections.
  65  */
  66
  67 /*ARGSUSED*/
  68 int
  69 main(argc, argv)
  70         int argc;
  71         char **argv;
  72 {
  73         int status;
  74         time_t tardy;
  75
  76         whoami = argv[0];
  77         /*
  78          * Error handler init.
  79          */
  80         init_sms_err_tbl();
  81         init_krb_err_tbl();
  82         set_com_err_hook(sms_com_err);
  83         setlinebuf(stderr);
  84
  85         if (argc != 1) {
  86                 com_err(whoami, 0, "Usage: smsd");
  87                 exit(1);
  88         }
  89
  90         /* Profiling implies that getting rid of one level of call
  91          * indirection here wins us maybe 1% on the VAX.
  92          */
  93         gdb_amv = malloc;
  94         gdb_fmv = free;
  95
  96         /*
  97          * GDB initialization.
  98          */
  99         if(gdb_init() != 0) {
 100                 com_err(whoami, 0, "GDB initialization failed.");
 101                 exit(1);
 102         }
 103         gdb_debug(0); /* this can be patched, if necessary, to enable */
 104                       /* GDB level debugging .. */
 105         krb_realm = malloc(REALM_SZ);
 106         get_krbrlm(krb_realm, 1);
 107
 108         /*
 109          * Database initialization.
 110          */
 111
 112         if ((status = sms_open_database()) != 0) {
 113                 com_err(whoami, status, " when trying to open database.");
 114                 exit(1);
 115         }
 116
 117         sanity_check_queries();
 118         sanity_check_database();
 119
 120         /*
 121          * Set up client array handler.
 122          */
 123         nclients = 0;
 124         clients = (client **) malloc(0);
 125
 126         /*
 127          * Signal handlers
 128          *      There should probably be a few more of these.
 129          */
 130
 131         if ((((int)signal (SIGTERM, sigshut)) < 0) ||
 132             (((int)signal (SIGCHLD, reapchild)) < 0) ||
 133             (((int)signal (SIGHUP, sigshut)) < 0)) {
 134                 com_err(whoami, errno, " Unable to establish signal handler.");
 135                 exit(1);
 136         }
 137
 138         journal = fopen(JOURNAL, "a");
 139         if (journal == NULL) {
 140             com_err(whoami, errno, " while opening journal file");
 141             exit(1);
 142         }
 143
 144         /*
 145          * Establish template connection.
 146          */
 147         if ((status = do_listen()) != 0) {
 148                 com_err(whoami, status,
 149                         " while trying to create listening connection");
 150                 exit(1);
 151         }
 152
 153         op_list = create_list_of_operations(1, listenop);
 154
 155         com_err(whoami, 0, "started (pid %d)", getpid());
 156         com_err(whoami, 0, rcsid_sms_main_c);
 157         send_zgram("SMS", "server started");
 158
 159         /*
 160          * Run until shut down.
 161          */
 162         while(!takedown) {
 163                 register int i;
 164                 /*
 165                  * Block until something happens.
 166                  */
 167 #ifdef notdef
 168                 com_err(whoami, 0, "tick");
 169 #endif notdef
 170                 errno = 0;
 171                 status = op_select_any(op_list, 0,
 172                                        (fd_set *)NULL, (fd_set *)NULL,
 173                                        (fd_set *)NULL, (struct timeval *)NULL);
 174
 175                 if (status == -1) {
 176                         com_err(whoami, errno, " error from op_select");
 177                         continue;
 178                 } else if (status != -2) {
 179                         com_err(whoami, 0, " wrong return from op_select_any");
 180                         continue;
 181                 }
 182                 if (takedown) break;
 183                 time(&now);
 184 #ifdef notdef
 185                 fprintf(stderr, "    tick\n");
 186 #endif notdef
 187                 /*
 188                  * Handle any new connections; this comes first so
 189                  * errno isn't tromped on.
 190                  */
 191                 if (OP_DONE(listenop)) {
 192                         if (OP_STATUS(listenop) == OP_CANCELLED) {
 193                                 if (errno == EWOULDBLOCK) {
 194                                         do_reset_listen();
 195                                 } else {
 196                                         com_err(whoami, errno,
 197                                                 " error on listen");
 198                                         exit(1);
 199                                 }
 200                         } else if ((status = new_connection()) != 0) {
 201                                 com_err(whoami, errno,
 202                                         " Error on listening operation.");
 203                                 /*
 204                                  * Sleep here to prevent hosing?
 205                                  */
 206                         }
 207                 }
 208                 /*
 209                  * Handle any existing connections.
 210                  */
 211                 tardy = now - 30*60;
 212
 213                 for (i=0; i<nclients; i++) {
 214                         cur_client = clients[i];
 215                         if (OP_DONE(clients[i]->pending_op)) {
 216                                 cur_client->last_time_used = now;
 217                                 do_client(cur_client);
 218                         } else if (clients[i]->last_time_used < tardy) {
 219                                 com_err(whoami, 0, "Shutting down connection due to inactivity");
 220                                 shutdown(cur_client->con->in.fd, 0);
 221                         }
 222                         cur_client = NULL;
 223                         if (takedown) break;
 224                 }
 225         }
 226         com_err(whoami, 0, "%s", takedown);
 227         sms_close_database();
 228         send_zgram("SMS", takedown);
 229         return 0;
 230 }
 231
 232 /*
 233  * Set up the template connection and queue the first accept.
 234  */
 235
 236 int
 237 do_listen()
 238 {
 239         char *service = index(SMS_GDB_SERV, ':') + 1;
 240
 241         listencon = create_listening_connection(service);
 242
 243         if (listencon == NULL)
 244                 return errno;
 245
 246         listenop = create_operation();
 247         client_addrlen = sizeof(client_addr);
 248
 249         start_accepting_client(listencon, listenop, &newconn,
 250                                (char *)&client_addr,
 251                                &client_addrlen, &client_tuple);
 252         return 0;
 253 }
 254
 255
 256 do_reset_listen()
 257 {
 258         client_addrlen = sizeof(client_addr);
 259         start_accepting_client(listencon, listenop, &newconn,
 260                                (char *)&client_addr,
 261                                &client_addrlen, &client_tuple);
 262 }
 263
 264 /*
 265  * This routine is called when a new connection comes in.
 266  *
 267  * It sets up a new client and adds it to the list of currently active clients.
 268  */
 269 int
 270 new_connection()
 271 {
 272         register client *cp;
 273         static counter = 0;
 274
 275         /*
 276          * Make sure there's been no error
 277          */
 278         if(OP_STATUS(listenop) != OP_COMPLETE) {
 279                 return errno;
 280         }
 281
 282         if (newconn == NULL) {
 283                 return SMS_NOT_CONNECTED;
 284         }
 285
 286         /*
 287          * Set up the new connection and reply to the client
 288          */
 289         cp = (client *)malloc(sizeof *cp);
 290         bzero(cp, sizeof(*cp));
 291         cp->state = CL_STARTING;
 292         cp->action = CL_ACCEPT;
 293         cp->con = newconn;
 294         cp->id = counter++;
 295         cp->args = NULL;
 296         cp->clname = NULL;
 297         cp->reply.sms_argv = NULL;
 298         cp->first = NULL;
 299         cp->last = NULL;
 300         cp->last_time_used = now;
 301         newconn = NULL;
 302
 303         cp->pending_op = create_operation();
 304         reset_operation(cp->pending_op);
 305         oplist_append(&op_list, cp->pending_op);
 306         cur_client = cp;
 307
 308         /*
 309          * Add a new client to the array..
 310          */
 311         clist_append(cp);
 312
 313         /*
 314          * Let him know we heard him.
 315          */
 316         start_replying_to_client(cp->pending_op, cp->con, GDB_ACCEPTED,
 317                                  "", "");
 318
 319         cp->haddr = client_addr;
 320
 321         /*
 322          * Log new connection.
 323          */
 324
 325         com_err(whoami, 0, "New connection from %s port %d (now %d client%s)",
 326                 inet_ntoa(cp->haddr.sin_addr),
 327                 (int)ntohs(cp->haddr.sin_port),
 328                 nclients,
 329                 nclients!=1?"s":"");
 330
 331         /*
 332          * Get ready to accept the next connection.
 333          */
 334         reset_operation(listenop);
 335         client_addrlen = sizeof(client_addr);
 336
 337         start_accepting_client(listencon, listenop, &newconn,
 338                                (char *)&client_addr,
 339                                &client_addrlen, &client_tuple);
 340         return 0;
 341 }
 342
 343 /*
 344  * Add a new client to the known clients.
 345  */
 346 void
 347 clist_append(cp)
 348         client *cp;
 349 {
 350         client **clients_n;
 351
 352         nclients++;
 353         clients_n = (client **)malloc
 354                 ((unsigned)(nclients * sizeof(client *)));
 355         bcopy((char *)clients, (char *)clients_n, (nclients-1)*sizeof(cp));
 356         clients_n[nclients-1] = cp;
 357         free((char *)clients);
 358         clients = clients_n;
 359         clients_n = NULL;
 360 }
 361
 362
 363 void
 364 clist_delete(cp)
 365         client *cp;
 366 {
 367         client **clients_n, **scpp, **dcpp; /* source and dest client */
 368                                             /* ptr ptr */
 369
 370         int found_it = 0;
 371
 372         clients_n = (client **)malloc
 373                 ((unsigned)((nclients - 1)* sizeof(client *)));
 374         for (scpp = clients, dcpp = clients_n; scpp < clients+nclients; ) {
 375                 if (*scpp != cp) {
 376                         *dcpp++ = *scpp++;
 377                 } else {
 378                         scpp++;
 379                         if (found_it) abort();
 380                         found_it = 1;
 381                 }
 382         }
 383         --nclients;
 384         free((char *)clients);
 385         clients = clients_n;
 386         clients_n = NULL;
 387         oplist_delete(op_list, cp->pending_op);
 388         reset_operation(cp->pending_op);
 389         delete_operation(cp->pending_op);
 390         sever_connection(cp->con);
 391         free((char *)cp);
 392 }
 393
 394 /*
 395  * Add a new operation to a list of operations.
 396  *
 397  * This should be rewritten to use realloc instead, since in most
 398  * cases it won't have to copy the array.
 399  */
 400
 401 void
 402 oplist_append(oplp, op)
 403         LIST_OF_OPERATIONS *oplp;
 404         OPERATION op;
 405 {
 406         int count = (*oplp)->count+1;
 407         LIST_OF_OPERATIONS newlist = (LIST_OF_OPERATIONS)
 408                 db_alloc(size_of_list_of_operations(count));
 409         bcopy((char *)(*oplp), (char *)newlist,
 410               size_of_list_of_operations((*oplp)->count));
 411         newlist->count++;
 412         newlist->op[count-1] = op;
 413         db_free((char *)(*oplp), size_of_list_of_operations(count-1));
 414         (*oplp) = newlist;
 415 }
 416
 417
 418 oplist_delete(oplp, op)
 419         LIST_OF_OPERATIONS oplp;
 420         register OPERATION op;
 421 {
 422         register OPERATION *s;
 423         register int c;
 424
 425         for (s = oplp->op, c=oplp->count; c; --c, ++s) {
 426                 if (*s == op) {
 427                         while (c > 0) {
 428                                 *s = *(s+1);
 429                                 ++s;
 430                                 --c;
 431                         }
 432                         oplp->count--;
 433                         return;
 434                 }
 435         }
 436         abort();
 437 }
 438
 439
 440 void reapchild()
 441 {
 442     union wait status;
 443     int pid;
 444
 445     while ((pid = wait3(&status, WNOHANG, (struct rusage *)0)) > 0) {
 446         if  (status.w_termsig == 0 && status.w_retcode == 0)
 447           com_err(whoami, 0, "dcm started successfully");
 448         else
 449           com_err(whoami, 0, "%d: startdcm exits with signal %d status %d",
 450                   pid, status.w_termsig, status.w_retcode);
 451     }
 452 }