lnet/router/router.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Copyright (C) 2002 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Portals
   7  *   http://sourceforge.net/projects/sandiaportals/
   8  *
   9  *   Portals is free software; you can redistribute it and/or
  10  *   modify it under the terms of version 2 of the GNU General Public
  11  *   License as published by the Free Software Foundation.
  12  *
  13  *   Portals is distributed in the hope that it will be useful,
  14  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *   GNU General Public License for more details.
  17  *
  18  *   You should have received a copy of the GNU General Public License
  19  *   along with Portals; if not, write to the Free Software
  20  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  */
  23
  24 #include "router.h"
  25
  26 LIST_HEAD(kpr_routes);
  27 LIST_HEAD(kpr_gateways);
  28 LIST_HEAD(kpr_nals);
  29
  30 unsigned long long kpr_fwd_bytes;
  31 unsigned long      kpr_fwd_packets;
  32 unsigned long      kpr_fwd_errors;
  33 atomic_t           kpr_queue_depth;
  34
  35 /* Mostly the tables are read-only (thread and interrupt context)
  36  *
  37  * Once in a blue moon we register/deregister NALs and add/remove routing
  38  * entries (thread context only)... */
  39 rwlock_t         kpr_rwlock = RW_LOCK_UNLOCKED;
  40
  41 kpr_router_interface_t kpr_router_interface = {
  42         kprri_register:         kpr_register_nal,
  43         kprri_lookup:           kpr_lookup_target,
  44         kprri_fwd_start:        kpr_forward_packet,
  45         kprri_fwd_done:         kpr_complete_packet,
  46         kprri_notify:           kpr_nal_notify,
  47         kprri_shutdown:         kpr_shutdown_nal,
  48         kprri_deregister:       kpr_deregister_nal,
  49 };
  50
  51 kpr_control_interface_t kpr_control_interface = {
  52         kprci_add_route:        kpr_add_route,
  53         kprci_del_route:        kpr_del_route,
  54         kprci_get_route:        kpr_get_route,
  55         kprci_notify:           kpr_sys_notify,
  56 };
  57
  58 int
  59 kpr_register_nal (kpr_nal_interface_t *nalif, void **argp)
  60 {
  61         unsigned long      flags;
  62         struct list_head  *e;
  63         kpr_nal_entry_t   *ne;
  64
  65         CDEBUG (D_NET, "Registering NAL %d\n", nalif->kprni_nalid);
  66
  67         PORTAL_ALLOC (ne, sizeof (*ne));
  68         if (ne == NULL)
  69                 return (-ENOMEM);
  70
  71         memset (ne, 0, sizeof (*ne));
  72         memcpy ((void *)&ne->kpne_interface, (void *)nalif, sizeof (*nalif));
  73
  74         LASSERT (!in_interrupt());
  75         write_lock_irqsave (&kpr_rwlock, flags);
  76
  77         for (e = kpr_nals.next; e != &kpr_nals; e = e->next)
  78         {
  79                 kpr_nal_entry_t *ne2 = list_entry (e, kpr_nal_entry_t, kpne_list);
  80
  81                 if (ne2->kpne_interface.kprni_nalid == ne->kpne_interface.kprni_nalid)
  82                 {
  83                         write_unlock_irqrestore (&kpr_rwlock, flags);
  84
  85                         CERROR ("Attempt to register same NAL %d twice\n", ne->kpne_interface.kprni_nalid);
  86
  87                         PORTAL_FREE (ne, sizeof (*ne));
  88                         return (-EEXIST);
  89                 }
  90         }
  91
  92         list_add (&ne->kpne_list, &kpr_nals);
  93
  94         write_unlock_irqrestore (&kpr_rwlock, flags);
  95
  96         *argp = ne;
  97         PORTAL_MODULE_USE;
  98         return (0);
  99 }
 100
 101 void
 102 kpr_do_upcall (void *arg)
 103 {
 104         kpr_upcall_t *u = (kpr_upcall_t *)arg;
 105         char          nalstr[10];
 106         char          nidstr[36];
 107         char          whenstr[36];
 108         char         *argv[] = {
 109                 NULL,
 110                 "ROUTER_NOTIFY",
 111                 nalstr,
 112                 nidstr,
 113                 u->kpru_alive ? "up" : "down",
 114                 whenstr,
 115                 NULL};
 116
 117         snprintf (nalstr, sizeof(nalstr), "%d", u->kpru_nal_id);
 118         snprintf (nidstr, sizeof(nidstr), LPX64, u->kpru_nid);
 119         snprintf (whenstr, sizeof(whenstr), "%ld", u->kpru_when);
 120
 121         portals_run_upcall (argv);
 122 }
 123
 124 void
 125 kpr_upcall (int gw_nalid, ptl_nid_t gw_nid, int alive, time_t when)
 126 {
 127         /* May be in arbitrary context */
 128         kpr_upcall_t  *u = kmalloc (sizeof (kpr_upcall_t), GFP_ATOMIC);
 129
 130         if (u == NULL) {
 131                 CERROR ("Upcall out of memory: nal %d nid "LPX64" %s\n",
 132                         gw_nalid, gw_nid, alive ? "up" : "down");
 133                 return;
 134         }
 135
 136         u->kpru_nal_id     = gw_nalid;
 137         u->kpru_nid        = gw_nid;
 138         u->kpru_alive      = alive;
 139         u->kpru_when       = when;
 140
 141         prepare_work (&u->kpru_tq, kpr_do_upcall, u);
 142         schedule_work (&u->kpru_tq);
 143 }
 144
 145 int
 146 kpr_do_notify (int byNal, int gateway_nalid, ptl_nid_t gateway_nid,
 147                int alive, time_t when)
 148 {
 149         unsigned long        flags;
 150         int                  rc = -ENOENT;
 151         kpr_nal_entry_t     *ne = NULL;
 152         kpr_gateway_entry_t *ge = NULL;
 153         struct timeval       now;
 154         struct list_head    *e;
 155         struct list_head    *n;
 156
 157         CDEBUG (D_ERROR, "%s notifying [%d] "LPX64": %s\n",
 158                 byNal ? "NAL" : "userspace",
 159                 gateway_nalid, gateway_nid, alive ? "up" : "down");
 160
 161         /* can't do predictions... */
 162         do_gettimeofday (&now);
 163         if (when > now.tv_sec) {
 164                 CERROR ("Ignoring prediction from %s of [%d] "LPX64" %s "
 165                         "%ld seconds in the future\n",
 166                 byNal ? "NAL" : "userspace",
 167                 gateway_nalid, gateway_nid, alive ? "up" : "down",
 168                         when - now.tv_sec);
 169                 return (EINVAL);
 170         }
 171
 172         LASSERT (when <= now.tv_sec);
 173
 174         /* Serialise with lookups (i.e. write lock) */
 175         write_lock_irqsave(&kpr_rwlock, flags);
 176
 177         list_for_each_safe (e, n, &kpr_gateways) {
 178
 179                 ge = list_entry(e, kpr_gateway_entry_t, kpge_list);
 180                 if ((gateway_nalid != 0 &&
 181                      ge->kpge_nalid != gateway_nalid) ||
 182                     ge->kpge_nid != gateway_nid)
 183                         continue;
 184
 185                 rc = 0;
 186                 break;
 187         }
 188
 189         if (rc != 0) {
 190                 /* gateway not found */
 191                 write_unlock_irqrestore(&kpr_rwlock, flags);
 192                 CERROR ("Gateway not found\n");
 193                 return (rc);
 194         }
 195
 196         if (when < ge->kpge_timestamp) {
 197                 /* out of date information */
 198                 write_unlock_irqrestore (&kpr_rwlock, flags);
 199                 CERROR ("Out of date\n");
 200                 return (0);
 201         }
 202
 203         /* update timestamp */
 204         ge->kpge_timestamp = when;
 205
 206         if ((!ge->kpge_alive) == (!alive)) {
 207                 /* new date for old news */
 208                 write_unlock_irqrestore (&kpr_rwlock, flags);
 209                 CERROR ("Old news\n");
 210                 return (0);
 211         }
 212
 213         ge->kpge_alive = alive;
 214         CDEBUG(D_NET, "set "LPX64" [%p] %d\n", gateway_nid, ge, alive);
 215
 216         if (alive) {
 217                 /* Reset all gateway weights so the newly-enabled gateway
 218                  * doesn't have to play catch-up */
 219                 list_for_each_safe (e, n, &kpr_gateways) {
 220                         kpr_gateway_entry_t *ge = list_entry(e, kpr_gateway_entry_t,
 221                                                              kpge_list);
 222                         atomic_set (&ge->kpge_weight, 0);
 223                 }
 224         }
 225
 226         if (!byNal) {
 227                 /* userland notified me: notify NAL? */
 228                 ne = kpr_find_nal_entry_locked (ge->kpge_nalid);
 229                 if (ne != NULL) {
 230                         if (ne->kpne_shutdown ||
 231                             ne->kpne_interface.kprni_notify == NULL) {
 232                                 /* no need to notify */
 233                                 ne = NULL;
 234                         } else {
 235                                 /* take a ref on this NAL until notifying
 236                                  * it has completed... */
 237                                 atomic_inc (&ne->kpne_refcount);
 238                         }
 239                 }
 240         }
 241
 242         write_unlock_irqrestore(&kpr_rwlock, flags);
 243
 244         if (ne != NULL) {
 245                 ne->kpne_interface.kprni_notify (ne->kpne_interface.kprni_arg,
 246                                                  gateway_nid, alive);
 247                 /* 'ne' can disappear now... */
 248                 atomic_dec (&ne->kpne_refcount);
 249         }
 250
 251         if (byNal) {
 252                 /* It wasn't userland that notified me... */
 253                 CERROR ("Doing upcall\n");
 254                 kpr_upcall (gateway_nalid, gateway_nid, alive, when);
 255         } else {
 256                 CERROR (" NOT Doing upcall\n");
 257         }
 258
 259         return (0);
 260 }
 261
 262 void
 263 kpr_nal_notify (void *arg, ptl_nid_t peer, int alive, time_t when)
 264 {
 265         kpr_nal_entry_t *ne = (kpr_nal_entry_t *)arg;
 266
 267         kpr_do_notify (1, ne->kpne_interface.kprni_nalid, peer, alive, when);
 268 }
 269
 270 void
 271 kpr_shutdown_nal (void *arg)
 272 {
 273         unsigned long    flags;
 274         kpr_nal_entry_t *ne = (kpr_nal_entry_t *)arg;
 275
 276         CDEBUG (D_NET, "Shutting down NAL %d\n", ne->kpne_interface.kprni_nalid);
 277
 278         LASSERT (!ne->kpne_shutdown);
 279         LASSERT (!in_interrupt());
 280
 281         write_lock_irqsave (&kpr_rwlock, flags); /* locking a bit spurious... */
 282         ne->kpne_shutdown = 1;
 283         write_unlock_irqrestore (&kpr_rwlock, flags); /* except it's a memory barrier */
 284
 285         while (atomic_read (&ne->kpne_refcount) != 0)
 286         {
 287                 CDEBUG (D_NET, "Waiting for refcount on NAL %d to reach zero (%d)\n",
 288                         ne->kpne_interface.kprni_nalid, atomic_read (&ne->kpne_refcount));
 289
 290                 set_current_state (TASK_UNINTERRUPTIBLE);
 291                 schedule_timeout (HZ);
 292         }
 293 }
 294
 295 void
 296 kpr_deregister_nal (void *arg)
 297 {
 298         unsigned long     flags;
 299         kpr_nal_entry_t  *ne = (kpr_nal_entry_t *)arg;
 300
 301         CDEBUG (D_NET, "Deregister NAL %d\n", ne->kpne_interface.kprni_nalid);
 302
 303         LASSERT (ne->kpne_shutdown);            /* caller must have issued shutdown already */
 304         LASSERT (atomic_read (&ne->kpne_refcount) == 0); /* can't be busy */
 305         LASSERT (!in_interrupt());
 306
 307         write_lock_irqsave (&kpr_rwlock, flags);
 308
 309         list_del (&ne->kpne_list);
 310
 311         write_unlock_irqrestore (&kpr_rwlock, flags);
 312
 313         PORTAL_FREE (ne, sizeof (*ne));
 314         PORTAL_MODULE_UNUSE;
 315 }
 316
 317 int
 318 kpr_ge_isbetter (kpr_gateway_entry_t *ge1, kpr_gateway_entry_t *ge2)
 319 {
 320         const int significant_bits = 0x00ffffff;
 321         /* We use atomic_t to record/compare route weights for
 322          * load-balancing.  Here we limit ourselves to only using
 323          * 'significant_bits' when we do an 'after' comparison */
 324
 325         int    diff = (atomic_read (&ge1->kpge_weight) -
 326                        atomic_read (&ge2->kpge_weight)) & significant_bits;
 327         int    rc = (diff > (significant_bits >> 1));
 328
 329         CDEBUG(D_NET, "[%p]"LPX64"=%d %s [%p]"LPX64"=%d\n",
 330                ge1, ge1->kpge_nid, atomic_read (&ge1->kpge_weight),
 331                rc ? ">" : "<",
 332                ge2, ge2->kpge_nid, atomic_read (&ge2->kpge_weight));
 333
 334         return (rc);
 335 }
 336
 337 void
 338 kpr_update_weight (kpr_gateway_entry_t *ge, int nob)
 339 {
 340         int weight = 1 + (nob + sizeof (ptl_hdr_t)/2)/sizeof (ptl_hdr_t);
 341
 342         /* We've chosen this route entry (i.e. gateway) to forward payload
 343          * of length 'nob'; update the route's weight to make it less
 344          * favoured.  Note that the weight is 1 plus the payload size
 345          * rounded and scaled to the portals header size, so we get better
 346          * use of the significant bits in kpge_weight. */
 347
 348         CDEBUG(D_NET, "gateway [%p]"LPX64" += %d\n", ge,
 349                ge->kpge_nid, weight);
 350
 351         atomic_add (weight, &ge->kpge_weight);
 352 }
 353
 354 int
 355 kpr_lookup_target (void *arg, ptl_nid_t target_nid, int nob,
 356                    ptl_nid_t *gateway_nidp)
 357 {
 358         kpr_nal_entry_t     *ne = (kpr_nal_entry_t *)arg;
 359         struct list_head    *e;
 360         kpr_route_entry_t   *re;
 361         kpr_gateway_entry_t *ge = NULL;
 362         int                  rc = -ENOENT;
 363
 364         /* Caller wants to know if 'target_nid' can be reached via a gateway
 365          * ON HER OWN NETWORK */
 366
 367         CDEBUG (D_NET, "lookup "LPX64" from NAL %d\n", target_nid,
 368                 ne->kpne_interface.kprni_nalid);
 369
 370         if (ne->kpne_shutdown)          /* caller is shutting down */
 371                 return (-ENOENT);
 372
 373         read_lock (&kpr_rwlock);
 374
 375         /* Search routes for one that has a gateway to target_nid on the callers network */
 376
 377         list_for_each (e, &kpr_routes) {
 378                 re = list_entry (e, kpr_route_entry_t, kpre_list);
 379
 380                 if (re->kpre_lo_nid > target_nid ||
 381                     re->kpre_hi_nid < target_nid)
 382                         continue;
 383
 384                 /* found table entry */
 385
 386                 if (re->kpre_gateway->kpge_nalid != ne->kpne_interface.kprni_nalid ||
 387                     !re->kpre_gateway->kpge_alive) {
 388                         /* different NAL or gateway down */
 389                         rc = -EHOSTUNREACH;
 390                         continue;
 391                 }
 392
 393                 if (ge == NULL ||
 394                     kpr_ge_isbetter (re->kpre_gateway, ge))
 395                     ge = re->kpre_gateway;
 396         }
 397
 398         if (ge != NULL) {
 399                 kpr_update_weight (ge, nob);
 400                 *gateway_nidp = ge->kpge_nid;
 401                 rc = 0;
 402         }
 403
 404         read_unlock (&kpr_rwlock);
 405
 406         /* NB can't deref 're' now; it might have been removed! */
 407
 408         CDEBUG (D_NET, "lookup "LPX64" from NAL %d: %d ("LPX64")\n",
 409                 target_nid, ne->kpne_interface.kprni_nalid, rc,
 410                 (rc == 0) ? *gateway_nidp : (ptl_nid_t)0);
 411         return (rc);
 412 }
 413
 414 kpr_nal_entry_t *
 415 kpr_find_nal_entry_locked (int nal_id)
 416 {
 417         struct list_head    *e;
 418
 419         /* Called with kpr_rwlock held */
 420
 421         list_for_each (e, &kpr_nals) {
 422                 kpr_nal_entry_t *ne = list_entry (e, kpr_nal_entry_t, kpne_list);
 423
 424                 if (nal_id != ne->kpne_interface.kprni_nalid) /* no match */
 425                         continue;
 426
 427                 return (ne);
 428         }
 429
 430         return (NULL);
 431 }
 432
 433 void
 434 kpr_forward_packet (void *arg, kpr_fwd_desc_t *fwd)
 435 {
 436         kpr_nal_entry_t     *src_ne = (kpr_nal_entry_t *)arg;
 437         ptl_nid_t            target_nid = fwd->kprfd_target_nid;
 438         int                  nob = fwd->kprfd_nob;
 439         kpr_gateway_entry_t *ge = NULL;
 440         kpr_nal_entry_t     *dst_ne = NULL;
 441         struct list_head    *e;
 442         kpr_route_entry_t   *re;
 443         kpr_nal_entry_t     *tmp_ne;
 444
 445         CDEBUG (D_NET, "forward [%p] "LPX64" from NAL %d\n", fwd,
 446                 target_nid, src_ne->kpne_interface.kprni_nalid);
 447
 448         LASSERT (nob >= sizeof (ptl_hdr_t)); /* at least got a packet header */
 449         LASSERT (nob == lib_iov_nob (fwd->kprfd_niov, fwd->kprfd_iov));
 450
 451         atomic_inc (&kpr_queue_depth);
 452         atomic_inc (&src_ne->kpne_refcount); /* source nal is busy until fwd completes */
 453
 454         kpr_fwd_packets++;                   /* (loose) stats accounting */
 455         kpr_fwd_bytes += nob;
 456
 457         if (src_ne->kpne_shutdown)           /* caller is shutting down */
 458                 goto out;
 459
 460         fwd->kprfd_router_arg = src_ne;      /* stash caller's nal entry */
 461
 462         read_lock (&kpr_rwlock);
 463
 464         /* Search routes for one that has a gateway to target_nid NOT on the caller's network */
 465
 466         list_for_each (e, &kpr_routes) {
 467                 re = list_entry (e, kpr_route_entry_t, kpre_list);
 468
 469                 if (re->kpre_lo_nid > target_nid || /* no match */
 470                     re->kpre_hi_nid < target_nid)
 471                         continue;
 472
 473                 if (re->kpre_gateway->kpge_nalid == src_ne->kpne_interface.kprni_nalid)
 474                         continue;               /* don't route to same NAL */
 475
 476                 if (!re->kpre_gateway->kpge_alive)
 477                         continue;               /* gateway is dead */
 478
 479                 tmp_ne = kpr_find_nal_entry_locked (re->kpre_gateway->kpge_nalid);
 480
 481                 if (tmp_ne == NULL ||
 482                     tmp_ne->kpne_shutdown) {
 483                         /* NAL must be registered and not shutting down */
 484                         continue;
 485                 }
 486
 487                 if (ge == NULL ||
 488                     kpr_ge_isbetter (re->kpre_gateway, ge)) {
 489                         ge = re->kpre_gateway;
 490                         dst_ne = tmp_ne;
 491                 }
 492         }
 493
 494         if (ge != NULL) {
 495                 LASSERT (dst_ne != NULL);
 496
 497                 kpr_update_weight (ge, nob);
 498
 499                 fwd->kprfd_gateway_nid = ge->kpge_nid;
 500                 atomic_inc (&dst_ne->kpne_refcount); /* dest nal is busy until fwd completes */
 501
 502                 read_unlock (&kpr_rwlock);
 503
 504                 CDEBUG (D_NET, "forward [%p] "LPX64" from NAL %d: "
 505                         "to "LPX64" on NAL %d\n",
 506                         fwd, target_nid, src_ne->kpne_interface.kprni_nalid,
 507                         fwd->kprfd_gateway_nid, dst_ne->kpne_interface.kprni_nalid);
 508
 509                 dst_ne->kpne_interface.kprni_fwd (dst_ne->kpne_interface.kprni_arg, fwd);
 510                 return;
 511         }
 512
 513         read_unlock (&kpr_rwlock);
 514  out:
 515         kpr_fwd_errors++;
 516
 517         CDEBUG (D_NET, "Failed to forward [%p] "LPX64" from NAL %d\n", fwd,
 518                 target_nid, src_ne->kpne_interface.kprni_nalid);
 519
 520         /* Can't find anywhere to forward to */
 521         (fwd->kprfd_callback)(fwd->kprfd_callback_arg, -EHOSTUNREACH);
 522
 523         atomic_dec (&kpr_queue_depth);
 524         atomic_dec (&src_ne->kpne_refcount);
 525 }
 526
 527 void
 528 kpr_complete_packet (void *arg, kpr_fwd_desc_t *fwd, int error)
 529 {
 530         kpr_nal_entry_t *dst_ne = (kpr_nal_entry_t *)arg;
 531         kpr_nal_entry_t *src_ne = (kpr_nal_entry_t *)fwd->kprfd_router_arg;
 532
 533         CDEBUG (D_NET, "complete(1) [%p] from NAL %d to NAL %d: %d\n", fwd,
 534                 src_ne->kpne_interface.kprni_nalid, dst_ne->kpne_interface.kprni_nalid, error);
 535
 536         atomic_dec (&dst_ne->kpne_refcount);    /* CAVEAT EMPTOR dst_ne can disappear now!!! */
 537
 538         (fwd->kprfd_callback)(fwd->kprfd_callback_arg, error);
 539
 540         CDEBUG (D_NET, "complete(2) [%p] from NAL %d: %d\n", fwd,
 541                 src_ne->kpne_interface.kprni_nalid, error);
 542
 543         atomic_dec (&kpr_queue_depth);
 544         atomic_dec (&src_ne->kpne_refcount);    /* CAVEAT EMPTOR src_ne can disappear now!!! */
 545 }
 546
 547 int
 548 kpr_add_route (int gateway_nalid, ptl_nid_t gateway_nid,
 549                ptl_nid_t lo_nid, ptl_nid_t hi_nid)
 550 {
 551         unsigned long        flags;
 552         struct list_head    *e;
 553         kpr_route_entry_t   *re;
 554         kpr_gateway_entry_t *ge;
 555         int                  dup = 0;
 556
 557         CDEBUG(D_NET, "Add route: %d "LPX64" : "LPX64" - "LPX64"\n",
 558                gateway_nalid, gateway_nid, lo_nid, hi_nid);
 559
 560         if (gateway_nalid == PTL_NID_ANY ||
 561             lo_nid == PTL_NID_ANY ||
 562             hi_nid == PTL_NID_ANY ||
 563             lo_nid > hi_nid)
 564                 return (-EINVAL);
 565
 566         PORTAL_ALLOC (ge, sizeof (*ge));
 567         if (ge == NULL)
 568                 return (-ENOMEM);
 569
 570         ge->kpge_nalid = gateway_nalid;
 571         ge->kpge_nid   = gateway_nid;
 572         ge->kpge_alive = 1;
 573         ge->kpge_timestamp = 0;
 574         ge->kpge_refcount = 0;
 575         atomic_set (&ge->kpge_weight, 0);
 576
 577         PORTAL_ALLOC (re, sizeof (*re));
 578         if (re == NULL)
 579                 return (-ENOMEM);
 580
 581         re->kpre_lo_nid = lo_nid;
 582         re->kpre_hi_nid = hi_nid;
 583
 584         LASSERT(!in_interrupt());
 585         write_lock_irqsave (&kpr_rwlock, flags);
 586
 587         list_for_each (e, &kpr_gateways) {
 588                 kpr_gateway_entry_t *ge2 = list_entry(e, kpr_gateway_entry_t,
 589                                                       kpge_list);
 590
 591                 if (ge2->kpge_nalid == gateway_nalid &&
 592                     ge2->kpge_nid == gateway_nid) {
 593                         PORTAL_FREE (ge, sizeof (*ge));
 594                         ge = ge2;
 595                         dup = 1;
 596                         break;
 597                 }
 598         }
 599
 600         if (!dup) {
 601                 /* Adding a new gateway... */
 602
 603                 list_add (&ge->kpge_list, &kpr_gateways);
 604
 605                 /* ...zero all gateway weights so this one doesn't have to
 606                  * play catch-up */
 607
 608                 list_for_each (e, &kpr_gateways) {
 609                         kpr_gateway_entry_t *ge2 = list_entry(e, kpr_gateway_entry_t,
 610                                                               kpge_list);
 611                         atomic_set (&ge2->kpge_weight, 0);
 612                 }
 613
 614         }
 615
 616         re->kpre_gateway = ge;
 617         ge->kpge_refcount++;
 618         list_add (&re->kpre_list, &kpr_routes);
 619
 620         write_unlock_irqrestore (&kpr_rwlock, flags);
 621         return (0);
 622 }
 623
 624 int
 625 kpr_sys_notify (int gateway_nalid, ptl_nid_t gateway_nid,
 626             int alive, time_t when)
 627 {
 628         return (kpr_do_notify (0, gateway_nalid, gateway_nid, alive, when));
 629 }
 630
 631 int
 632 kpr_del_route (int gw_nalid, ptl_nid_t gw_nid,
 633                ptl_nid_t lo, ptl_nid_t hi)
 634 {
 635         int                specific = (lo != PTL_NID_ANY);
 636         unsigned long      flags;
 637         int                rc = -ENOENT;
 638         struct list_head  *e;
 639         struct list_head  *n;
 640
 641         CDEBUG(D_NET, "Del route [%d] "LPX64" : "LPX64" - "LPX64"\n",
 642                gw_nalid, gw_nid, lo, hi);
 643
 644         LASSERT(!in_interrupt());
 645
 646         /* NB Caller may specify either all routes via the given gateway
 647          * (lo/hi == PTL_NID_ANY) or a specific route entry (lo/hi are
 648          * actual NIDs) */
 649
 650         if (specific ? (hi == PTL_NID_ANY || hi < lo) : (hi != PTL_NID_ANY))
 651                 return (-EINVAL);
 652
 653         write_lock_irqsave(&kpr_rwlock, flags);
 654
 655         list_for_each_safe (e, n, &kpr_routes) {
 656                 kpr_route_entry_t   *re = list_entry(e, kpr_route_entry_t,
 657                                                    kpre_list);
 658                 kpr_gateway_entry_t *ge = re->kpre_gateway;
 659
 660                 if (ge->kpge_nalid != gw_nalid ||
 661                     ge->kpge_nid != gw_nid ||
 662                     (specific &&
 663                      (lo != re->kpre_lo_nid || hi != re->kpre_hi_nid)))
 664                         continue;
 665
 666                 rc = 0;
 667
 668                 if (--ge->kpge_refcount == 0) {
 669                         list_del (&ge->kpge_list);
 670                         PORTAL_FREE (ge, sizeof (*ge));
 671                 }
 672
 673                 list_del (&re->kpre_list);
 674                 PORTAL_FREE(re, sizeof (*re));
 675
 676                 if (specific)
 677                         break;
 678         }
 679
 680         write_unlock_irqrestore(&kpr_rwlock, flags);
 681         return (rc);
 682 }
 683
 684 int
 685 kpr_get_route (int idx, int *gateway_nalid, ptl_nid_t *gateway_nid,
 686                ptl_nid_t *lo_nid, ptl_nid_t *hi_nid, int *alive)
 687 {
 688         struct list_head  *e;
 689
 690         read_lock(&kpr_rwlock);
 691
 692         for (e = kpr_routes.next; e != &kpr_routes; e = e->next) {
 693                 kpr_route_entry_t   *re = list_entry(e, kpr_route_entry_t,
 694                                                      kpre_list);
 695                 kpr_gateway_entry_t *ge = re->kpre_gateway;
 696
 697                 if (idx-- == 0) {
 698                         *gateway_nalid = ge->kpge_nalid;
 699                         *gateway_nid = ge->kpge_nid;
 700                         *alive = ge->kpge_alive;
 701                         *lo_nid = re->kpre_lo_nid;
 702                         *hi_nid = re->kpre_hi_nid;
 703
 704                         read_unlock(&kpr_rwlock);
 705                         return (0);
 706                 }
 707         }
 708
 709         read_unlock (&kpr_rwlock);
 710         return (-ENOENT);
 711 }
 712
 713 static void /*__exit*/
 714 kpr_finalise (void)
 715 {
 716         LASSERT (list_empty (&kpr_nals));
 717
 718         while (!list_empty (&kpr_routes)) {
 719                 kpr_route_entry_t *re = list_entry(kpr_routes.next,
 720                                                    kpr_route_entry_t,
 721                                                    kpre_list);
 722
 723                 list_del(&re->kpre_list);
 724                 PORTAL_FREE(re, sizeof (*re));
 725         }
 726
 727         kpr_proc_fini();
 728
 729         PORTAL_SYMBOL_UNREGISTER(kpr_router_interface);
 730         PORTAL_SYMBOL_UNREGISTER(kpr_control_interface);
 731
 732         CDEBUG(D_MALLOC, "kpr_finalise: kmem back to %d\n",
 733                atomic_read(&portal_kmemory));
 734 }
 735
 736 static int __init
 737 kpr_initialise (void)
 738 {
 739         CDEBUG(D_MALLOC, "kpr_initialise: kmem %d\n",
 740                atomic_read(&portal_kmemory));
 741
 742         kpr_proc_init();
 743
 744         PORTAL_SYMBOL_REGISTER(kpr_router_interface);
 745         PORTAL_SYMBOL_REGISTER(kpr_control_interface);
 746         return (0);
 747 }
 748
 749 MODULE_AUTHOR("Eric Barton");
 750 MODULE_DESCRIPTION("Kernel Portals Router v0.01");
 751 MODULE_LICENSE("GPL");
 752
 753 module_init (kpr_initialise);
 754 module_exit (kpr_finalise);
 755
 756 EXPORT_SYMBOL (kpr_control_interface);
 757 EXPORT_SYMBOL (kpr_router_interface);