src/WINNT/afsd/cm_server.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 #include <afs/param.h>
  11 #include <afs/stds.h>
  12
  13 #ifndef DJGPP
  14 #include <windows.h>
  15 #include <winsock2.h>
  16 #include <nb30.h>
  17 #else
  18 #include <sys/socket.h>
  19 #endif /* !DJGPP */
  20 #include <stdlib.h>
  21 #include <malloc.h>
  22 #include <string.h>
  23
  24 #include <osi.h>
  25 #include <rx/rx.h>
  26 #include "afsd.h"
  27
  28 osi_rwlock_t cm_serverLock;
  29
  30 cm_server_t *cm_allServersp;
  31
  32 int cm_noIPAddr;         /* number of client network interfaces */
  33 int cm_IPAddr[CM_MAXINTERFACE_ADDR];    /* client's IP address in host order */
  34 int cm_SubnetMask[CM_MAXINTERFACE_ADDR];/* client's subnet mask in host order*/
  35 int cm_NetMtu[CM_MAXINTERFACE_ADDR];    /* client's MTU sizes */
  36 int cm_NetFlags[CM_MAXINTERFACE_ADDR];  /* network flags */
  37
  38 void cm_CheckServers(long flags, cm_cell_t *cellp)
  39 {
  40         /* ping all file servers, up or down, with unauthenticated connection,
  41          * to find out whether we have all our callbacks from the server still.
  42          * Also, ping down VLDBs.
  43          */
  44         cm_server_t *tsp;
  45         long code;
  46         long secs;
  47         long usecs;
  48         int doPing;
  49         int serverType;
  50         long now;
  51         int wasDown;
  52         cm_conn_t *connp;
  53
  54         lock_ObtainWrite(&cm_serverLock);
  55         for(tsp = cm_allServersp; tsp; tsp = tsp->allNextp) {
  56                 tsp->refCount++;
  57                 lock_ReleaseWrite(&cm_serverLock);
  58
  59                 /* now process the server */
  60                 lock_ObtainMutex(&tsp->mx);
  61
  62                 /* what time is it? */
  63                 now = osi_Time();
  64
  65                 serverType = tsp->type;
  66                 doPing = 0;
  67                 wasDown = tsp->flags & CM_SERVERFLAG_DOWN;
  68
  69                 /* only do the ping if the cell matches the requested cell, or we're
  70                  * matching all cells (cellp == NULL), and if we've requested to ping
  71                  * this type of {up, down} servers.
  72                  */
  73                 if ((cellp == NULL || cellp == tsp->cellp) &&
  74                         ((wasDown && (flags & CM_FLAG_CHECKDOWNSERVERS)) ||
  75                          (!wasDown && (flags & CM_FLAG_CHECKUPSERVERS)))) {
  76
  77                         doPing = 1;
  78                 }       /* we're supposed to check this up/down server */
  79                 lock_ReleaseMutex(&tsp->mx);
  80
  81                 /* at this point, we've adjusted the server state, so do the ping and
  82                  * adjust things.
  83                  */
  84                 if (doPing) {
  85                         code = cm_ConnByServer(tsp, cm_rootUserp, &connp);
  86                         if (code == 0) {
  87                                 /* now call the appropriate ping call.  Drop the timeout if
  88                                  * the server is known to be down, so that we don't waste a
  89                                  * lot of time retiming out down servers.
  90                                  */
  91                                 if (wasDown)
  92                                         rx_SetConnDeadTime(connp->callp, 10);
  93                                 if (serverType == CM_SERVER_VLDB) {
  94                                         code = VL_ProbeServer(connp->callp);
  95                                 }
  96                                 else {
  97                                         /* file server */
  98                                         code = RXAFS_GetTime(connp->callp, &secs, &usecs);
  99                                 }
 100                                 if (wasDown)
 101                                         rx_SetConnDeadTime(connp->callp, CM_CONN_CONNDEADTIME);
 102                                 cm_PutConn(connp);
 103                         }       /* got an unauthenticated connection to this server */
 104
 105                         lock_ObtainMutex(&tsp->mx);
 106                         if (code == 0) {
 107                                 /* mark server as up */
 108                                 tsp->flags &= ~CM_SERVERFLAG_DOWN;
 109                         }
 110                         else {
 111                                 /* mark server as down */
 112                                 tsp->flags |= CM_SERVERFLAG_DOWN;
 113                         }
 114                         lock_ReleaseMutex(&tsp->mx);
 115                 }
 116
 117                 /* also, run the GC function for connections on all of the
 118                  * server's connections.
 119                  */
 120                 cm_GCConnections(tsp);
 121
 122                 lock_ObtainWrite(&cm_serverLock);
 123                 osi_assert(tsp->refCount-- > 0);
 124         }
 125         lock_ReleaseWrite(&cm_serverLock);
 126 }
 127
 128 void cm_InitServer(void)
 129 {
 130         static osi_once_t once;
 131
 132         if (osi_Once(&once)) {
 133                 lock_InitializeRWLock(&cm_serverLock, "cm_serverLock");
 134                 osi_EndOnce(&once);
 135         }
 136 }
 137
 138 void cm_PutServer(cm_server_t *serverp)
 139 {
 140         lock_ObtainWrite(&cm_serverLock);
 141         osi_assert(serverp->refCount-- > 0);
 142         lock_ReleaseWrite(&cm_serverLock);
 143 }
 144
 145 void cm_SetServerPrefs(cm_server_t * serverp)
 146 {
 147         unsigned long   serverAddr;     /* in host byte order */
 148         unsigned long   myAddr, myNet, mySubnet;/* in host byte order */
 149         unsigned long   netMask;
 150         int             i;
 151
 152         /* implement server prefs for fileservers only */
 153         if ( serverp->type == CM_SERVER_FILE )
 154         {
 155             serverAddr = ntohl(serverp->addr.sin_addr.s_addr);
 156             serverp->ipRank  = CM_IPRANK_LOW;   /* default setings */
 157
 158             for ( i=0; i < cm_noIPAddr; i++)
 159             {
 160                 /* loop through all the client's IP address and compare
 161                 ** each of them against the server's IP address */
 162
 163                 myAddr = cm_IPAddr[i];
 164                 if ( IN_CLASSA(myAddr) )
 165                     netMask = IN_CLASSA_NET;
 166                 else if ( IN_CLASSB(myAddr) )
 167                     netMask = IN_CLASSB_NET;
 168                 else if ( IN_CLASSC(myAddr) )
 169                     netMask = IN_CLASSC_NET;
 170                 else
 171                     netMask = 0;
 172
 173                 myNet    =  myAddr & netMask;
 174                 mySubnet =  myAddr & cm_SubnetMask[i];
 175
 176                 if ( (serverAddr & netMask) == myNet )
 177                 {
 178                     if ( (serverAddr & cm_SubnetMask[i]) == mySubnet)
 179                     {
 180                         if ( serverAddr == myAddr )
 181                             serverp->ipRank = min(serverp->ipRank,
 182                                               CM_IPRANK_TOP);/* same machine */
 183                         else serverp->ipRank = min(serverp->ipRank,
 184                                               CM_IPRANK_HI); /* same subnet */
 185                     }
 186                     else serverp->ipRank = min(serverp->ipRank,CM_IPRANK_MED);
 187                                                            /* same net */
 188                 }
 189                                                  /* random between 0..15*/
 190                 serverp->ipRank += min(serverp->ipRank, rand() % 0x000f);
 191             } /* and of for loop */
 192         }
 193         else    serverp->ipRank = 10000 + (rand() % 0x00ff); /* VL server */
 194 }
 195
 196 cm_server_t *cm_NewServer(struct sockaddr_in *socketp, int type, cm_cell_t *cellp) {
 197         cm_server_t *tsp;
 198
 199         osi_assert(socketp->sin_family == AF_INET);
 200
 201         tsp = malloc(sizeof(*tsp));
 202     memset(tsp, 0, sizeof(*tsp));
 203         tsp->type = type;
 204     tsp->cellp = cellp;
 205     tsp->refCount = 1;
 206         lock_InitializeMutex(&tsp->mx, "cm_server_t mutex");
 207         tsp->addr = *socketp;
 208
 209         cm_SetServerPrefs(tsp);
 210
 211     lock_ObtainWrite(&cm_serverLock); /* get server lock */
 212         tsp->allNextp = cm_allServersp;
 213     cm_allServersp = tsp;
 214     lock_ReleaseWrite(&cm_serverLock); /* release server lock */
 215
 216     return tsp;
 217 }
 218
 219 /* find a server based on its properties */
 220 cm_server_t *cm_FindServer(struct sockaddr_in *addrp, int type)
 221 {
 222         cm_server_t *tsp;
 223
 224         osi_assert(addrp->sin_family == AF_INET);
 225
 226         lock_ObtainWrite(&cm_serverLock);
 227         for(tsp = cm_allServersp; tsp; tsp=tsp->allNextp) {
 228                 if (tsp->type == type &&
 229                         tsp->addr.sin_addr.s_addr == addrp->sin_addr.s_addr) break;
 230         }
 231
 232         /* bump ref count if we found the server */
 233         if (tsp) tsp->refCount++;
 234
 235         /* drop big table lock */
 236         lock_ReleaseWrite(&cm_serverLock);
 237
 238         /* return what we found */
 239         return tsp;
 240 }
 241
 242 cm_serverRef_t *cm_NewServerRef(cm_server_t *serverp)
 243 {
 244         cm_serverRef_t *tsrp;
 245
 246         lock_ObtainWrite(&cm_serverLock);
 247         serverp->refCount++;
 248         lock_ReleaseWrite(&cm_serverLock);
 249         tsrp = malloc(sizeof(*tsrp));
 250         tsrp->server = serverp;
 251         tsrp->status = not_busy;
 252         tsrp->next = NULL;
 253
 254         return tsrp;
 255 }
 256
 257 long cm_ChecksumServerList(cm_serverRef_t *serversp)
 258 {
 259         long sum = 0;
 260         int first = 1;
 261         cm_serverRef_t *tsrp;
 262
 263     lock_ObtainWrite(&cm_serverLock);
 264
 265         for (tsrp = serversp; tsrp; tsrp=tsrp->next) {
 266                 if (first)
 267                         first = 0;
 268                 else
 269                         sum <<= 1;
 270                 sum ^= (long) tsrp->server;
 271         }
 272
 273     lock_ReleaseWrite(&cm_serverLock);
 274         return sum;
 275 }
 276
 277 /*
 278 ** Insert a server into the server list keeping the list sorted in
 279 ** asending order of ipRank.
 280 */
 281 void cm_InsertServerList(cm_serverRef_t** list, cm_serverRef_t* element)
 282 {
 283         cm_serverRef_t  *current=*list;
 284         unsigned short ipRank = element->server->ipRank;
 285
 286     lock_ObtainWrite(&cm_serverLock);
 287
 288         /* insertion into empty list  or at the beginning of the list */
 289         if ( !current || (current->server->ipRank > ipRank) )
 290         {
 291                 element->next = *list;
 292                 *list = element;
 293         lock_ReleaseWrite(&cm_serverLock);
 294                 return ;
 295         }
 296
 297         while ( current->next ) /* find appropriate place to insert */
 298         {
 299                 if ( current->next->server->ipRank > ipRank )
 300                         break;
 301                 else current = current->next;
 302         }
 303         element->next = current->next;
 304         current->next = element;
 305     lock_ReleaseWrite(&cm_serverLock);
 306 }
 307 /*
 308 ** Re-sort the server list with the modified rank
 309 ** returns 0 if element was changed successfully.
 310 ** returns 1 if  list remained unchanged.
 311 */
 312 long cm_ChangeRankServer(cm_serverRef_t** list, cm_server_t*    server)
 313 {
 314         cm_serverRef_t  **current=list;
 315         cm_serverRef_t  *element=0;
 316
 317         /* if there is max of one element in the list, nothing to sort */
 318         if ( (!*current) || !((*current)->next)  )
 319                 return 1;               /* list unchanged: return success */
 320
 321     lock_ObtainWrite(&cm_serverLock);
 322         /* if the server is on the list, delete it from list */
 323         while ( *current )
 324         {
 325                 if ( (*current)->server == server)
 326                 {
 327                         element = (*current);
 328                         *current = (*current)->next; /* delete it */
 329                         break;
 330                 }
 331                 current = & ( (*current)->next);
 332         }
 333     lock_ReleaseWrite(&cm_serverLock);
 334
 335     /* if this volume is not replicated on this server  */
 336         if (!element)
 337                 return 1;       /* server is not on list */
 338
 339         /* re-insert deleted element into the list with modified rank*/
 340         cm_InsertServerList(list, element);
 341         return 0;
 342 }
 343 /*
 344 ** If there are more than one server on the list and the first n servers on
 345 ** the list have the same rank( n>1), then randomise among the first n servers.
 346 */
 347 void cm_RandomizeServer(cm_serverRef_t** list)
 348 {
 349         int             count, picked;
 350         cm_serverRef_t* tsrp = *list, *lastTsrp;
 351         unsigned short  lowestRank;
 352
 353         /* an empty list or a list with only one element */
 354         if ( !tsrp || ! tsrp->next )
 355                 return ;
 356
 357     lock_ObtainWrite(&cm_serverLock);
 358
 359         /* count the number of servers with the lowest rank */
 360         lowestRank = tsrp->server->ipRank;
 361         for ( count=1, tsrp=tsrp->next; tsrp; tsrp=tsrp->next)
 362         {
 363                 if ( tsrp->server->ipRank != lowestRank)
 364                         break;
 365                 else
 366                         count++;
 367         }
 368
 369         /* if there is only one server with the lowest rank, we are done */
 370         if ( count <= 1 ) {
 371         lock_ReleaseWrite(&cm_serverLock);
 372                 return ;
 373     }
 374
 375         picked = rand() % count;
 376         if ( !picked ) {
 377         lock_ReleaseWrite(&cm_serverLock);
 378                 return ;
 379     }
 380
 381         tsrp = *list;
 382         while (--picked >= 0)
 383         {
 384                 lastTsrp = tsrp;
 385                 tsrp = tsrp->next;
 386         }
 387         lastTsrp->next = tsrp->next;  /* delete random element from list*/
 388         tsrp->next     = *list; /* insert element at the beginning of list */
 389         *list          = tsrp;
 390     lock_ReleaseWrite(&cm_serverLock);
 391 }
 392
 393 void cm_FreeServerList(cm_serverRef_t** list)
 394 {
 395     cm_serverRef_t  *current = *list;
 396     cm_serverRef_t  *next = 0;
 397
 398     lock_ObtainWrite(&cm_serverLock);
 399
 400     while (current)
 401     {
 402            next = current->next;
 403            free(current);
 404            current = next;
 405     }
 406
 407     lock_ReleaseWrite(&cm_serverLock);
 408 }
 409