lustre/portals/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         kfree (u);
 124 }
 125
 126 void
 127 kpr_upcall (int gw_nalid, ptl_nid_t gw_nid, int alive, time_t when)
 128 {
 129         /* May be in arbitrary context */
 130         kpr_upcall_t  *u = kmalloc (sizeof (kpr_upcall_t), GFP_ATOMIC);
 131
 132         if (u == NULL) {
 133                 CERROR ("Upcall out of memory: nal %d nid "LPX64" %s\n",
 134                         gw_nalid, gw_nid, alive ? "up" : "down");
 135                 return;
 136         }
 137
 138         u->kpru_nal_id     = gw_nalid;
 139         u->kpru_nid        = gw_nid;
 140         u->kpru_alive      = alive;
 141         u->kpru_when       = when;
 142
 143         prepare_work (&u->kpru_tq, kpr_do_upcall, u);
 144         schedule_work (&u->kpru_tq);
 145 }
 146
 147 int
 148 kpr_do_notify (int byNal, int gateway_nalid, ptl_nid_t gateway_nid,
 149                int alive, time_t when)
 150 {
 151         unsigned long        flags;
 152         int                  found;
 153         kpr_nal_entry_t     *ne = NULL;
 154         kpr_gateway_entry_t *ge = NULL;
 155         struct timeval       now;
 156         struct list_head    *e;
 157         struct list_head    *n;
 158
 159         CDEBUG (D_NET, "%s notifying [%d] "LPX64": %s\n",
 160                 byNal ? "NAL" : "userspace",
 161                 gateway_nalid, gateway_nid, alive ? "up" : "down");
 162
 163         /* can't do predictions... */
 164         do_gettimeofday (&now);
 165         if (when > now.tv_sec) {
 166                 CWARN ("Ignoring prediction from %s of [%d] "LPX64" %s "
 167                        "%ld seconds in the future\n",
 168                        byNal ? "NAL" : "userspace",
 169                        gateway_nalid, gateway_nid,
 170                        alive ? "up" : "down",
 171                        when - now.tv_sec);
 172                 return (EINVAL);
 173         }
 174
 175         LASSERT (when <= now.tv_sec);
 176
 177         /* Serialise with lookups (i.e. write lock) */
 178         write_lock_irqsave(&kpr_rwlock, flags);
 179
 180         found = 0;
 181         list_for_each_safe (e, n, &kpr_gateways) {
 182
 183                 ge = list_entry(e, kpr_gateway_entry_t, kpge_list);
 184                 if ((gateway_nalid != 0 &&
 185                      ge->kpge_nalid != gateway_nalid) ||
 186                     ge->kpge_nid != gateway_nid)
 187                         continue;
 188
 189                 found = 1;
 190                 break;
 191         }
 192
 193         if (!found) {
 194                 /* gateway not found */
 195                 write_unlock_irqrestore(&kpr_rwlock, flags);
 196                 CDEBUG (D_NET, "Gateway not found\n");
 197                 return (0);
 198         }
 199
 200         if (when < ge->kpge_timestamp) {
 201                 /* out of date information */
 202                 write_unlock_irqrestore (&kpr_rwlock, flags);
 203                 CDEBUG (D_NET, "Out of date\n");
 204                 return (0);
 205         }
 206
 207         /* update timestamp */
 208         ge->kpge_timestamp = when;
 209
 210         if ((!ge->kpge_alive) == (!alive)) {
 211                 /* new date for old news */
 212                 write_unlock_irqrestore (&kpr_rwlock, flags);
 213                 CDEBUG (D_NET, "Old news\n");
 214                 return (0);
 215         }
 216
 217         ge->kpge_alive = alive;
 218         CDEBUG(D_NET, "set "LPX64" [%p] %d\n", gateway_nid, ge, alive);
 219
 220         if (alive) {
 221                 /* Reset all gateway weights so the newly-enabled gateway
 222                  * doesn't have to play catch-up */
 223                 list_for_each_safe (e, n, &kpr_gateways) {
 224                         kpr_gateway_entry_t *ge = list_entry(e, kpr_gateway_entry_t,
 225                                                              kpge_list);
 226                         atomic_set (&ge->kpge_weight, 0);
 227                 }
 228         }
 229
 230         found = 0;
 231         if (!byNal) {
 232                 /* userland notified me: notify NAL? */
 233                 ne = kpr_find_nal_entry_locked (ge->kpge_nalid);
 234                 if (ne != NULL) {
 235                         if (!ne->kpne_shutdown &&
 236                             ne->kpne_interface.kprni_notify != NULL) {
 237                                 /* take a ref on this NAL until notifying
 238                                  * it has completed... */
 239                                 atomic_inc (&ne->kpne_refcount);
 240                                 found = 1;
 241                         }
 242                 }
 243         }
 244
 245         write_unlock_irqrestore(&kpr_rwlock, flags);
 246
 247         if (found) {
 248                 ne->kpne_interface.kprni_notify (ne->kpne_interface.kprni_arg,
 249                                                  gateway_nid, alive);
 250                 /* 'ne' can disappear now... */
 251                 atomic_dec (&ne->kpne_refcount);
 252         }
 253
 254         if (byNal) {
 255                 /* It wasn't userland that notified me... */
 256                 CWARN ("Upcall: NAL %d NID "LPX64" is %s\n",
 257                        gateway_nalid, gateway_nid,
 258                        alive ? "alive" : "dead");
 259                 kpr_upcall (gateway_nalid, gateway_nid, alive, when);
 260         } else {
 261                 CDEBUG (D_NET, " NOT Doing upcall\n");
 262         }
 263
 264         return (0);
 265 }
 266
 267 void
 268 kpr_nal_notify (void *arg, ptl_nid_t peer, int alive, time_t when)
 269 {
 270         kpr_nal_entry_t *ne = (kpr_nal_entry_t *)arg;
 271
 272         kpr_do_notify (1, ne->kpne_interface.kprni_nalid, peer, alive, when);
 273 }
 274
 275 void
 276 kpr_shutdown_nal (void *arg)
 277 {
 278         unsigned long    flags;
 279         kpr_nal_entry_t *ne = (kpr_nal_entry_t *)arg;
 280
 281         CDEBUG (D_NET, "Shutting down NAL %d\n", ne->kpne_interface.kprni_nalid);
 282
 283         LASSERT (!ne->kpne_shutdown);
 284         LASSERT (!in_interrupt());
 285
 286         write_lock_irqsave (&kpr_rwlock, flags); /* locking a bit spurious... */
 287         ne->kpne_shutdown = 1;
 288         write_unlock_irqrestore (&kpr_rwlock, flags); /* except it's a memory barrier */
 289
 290         while (atomic_read (&ne->kpne_refcount) != 0)
 291         {
 292                 CDEBUG (D_NET, "Waiting for refcount on NAL %d to reach zero (%d)\n",
 293                         ne->kpne_interface.kprni_nalid, atomic_read (&ne->kpne_refcount));
 294
 295                 set_current_state (TASK_UNINTERRUPTIBLE);
 296                 schedule_timeout (HZ);
 297         }
 298 }
 299
 300 void
 301 kpr_deregister_nal (void *arg)
 302 {
 303         unsigned long     flags;
 304         kpr_nal_entry_t  *ne = (kpr_nal_entry_t *)arg;
 305
 306         CDEBUG (D_NET, "Deregister NAL %d\n", ne->kpne_interface.kprni_nalid);
 307
 308         LASSERT (ne->kpne_shutdown);            /* caller must have issued shutdown already */
 309         LASSERT (atomic_read (&ne->kpne_refcount) == 0); /* can't be busy */
 310         LASSERT (!in_interrupt());
 311
 312         write_lock_irqsave (&kpr_rwlock, flags);
 313
 314         list_del (&ne->kpne_list);
 315
 316         write_unlock_irqrestore (&kpr_rwlock, flags);
 317
 318         PORTAL_FREE (ne, sizeof (*ne));
 319         PORTAL_MODULE_UNUSE;
 320 }
 321
 322 int
 323 kpr_ge_isbetter (kpr_gateway_entry_t *ge1, kpr_gateway_entry_t *ge2)
 324 {
 325         const int significant_bits = 0x00ffffff;
 326         /* We use atomic_t to record/compare route weights for
 327          * load-balancing.  Here we limit ourselves to only using
 328          * 'significant_bits' when we do an 'after' comparison */
 329
 330         int    diff = (atomic_read (&ge1->kpge_weight) -
 331                        atomic_read (&ge2->kpge_weight)) & significant_bits;
 332         int    rc = (diff > (significant_bits >> 1));
 333
 334         CDEBUG(D_NET, "[%p]"LPX64"=%d %s [%p]"LPX64"=%d\n",
 335                ge1, ge1->kpge_nid, atomic_read (&ge1->kpge_weight),
 336                rc ? ">" : "<",
 337                ge2, ge2->kpge_nid, atomic_read (&ge2->kpge_weight));
 338
 339         return (rc);
 340 }
 341
 342 void
 343 kpr_update_weight (kpr_gateway_entry_t *ge, int nob)
 344 {
 345         int weight = 1 + (nob + sizeof (ptl_hdr_t)/2)/sizeof (ptl_hdr_t);
 346
 347         /* We've chosen this route entry (i.e. gateway) to forward payload
 348          * of length 'nob'; update the route's weight to make it less
 349          * favoured.  Note that the weight is 1 plus the payload size
 350          * rounded and scaled to the portals header size, so we get better
 351          * use of the significant bits in kpge_weight. */
 352
 353         CDEBUG(D_NET, "gateway [%p]"LPX64" += %d\n", ge,
 354                ge->kpge_nid, weight);
 355
 356         atomic_add (weight, &ge->kpge_weight);
 357 }
 358
 359 int
 360 kpr_lookup_target (void *arg, ptl_nid_t target_nid, int nob,
 361                    ptl_nid_t *gateway_nidp)
 362 {
 363         kpr_nal_entry_t     *ne = (kpr_nal_entry_t *)arg;
 364         struct list_head    *e;
 365         kpr_route_entry_t   *re;
 366         kpr_gateway_entry_t *ge = NULL;
 367         int                  rc = -ENOENT;
 368
 369         /* Caller wants to know if 'target_nid' can be reached via a gateway
 370          * ON HER OWN NETWORK */
 371
 372         CDEBUG (D_NET, "lookup "LPX64" from NAL %d\n", target_nid,
 373                 ne->kpne_interface.kprni_nalid);
 374
 375         if (ne->kpne_shutdown)          /* caller is shutting down */
 376                 return (-ENOENT);
 377
 378         read_lock (&kpr_rwlock);
 379
 380         /* Search routes for one that has a gateway to target_nid on the callers network */
 381
 382         list_for_each (e, &kpr_routes) {
 383                 re = list_entry (e, kpr_route_entry_t, kpre_list);
 384
 385                 if (re->kpre_lo_nid > target_nid ||
 386                     re->kpre_hi_nid < target_nid)
 387                         continue;
 388
 389                 /* found table entry */
 390
 391                 if (re->kpre_gateway->kpge_nalid != ne->kpne_interface.kprni_nalid ||
 392                     !re->kpre_gateway->kpge_alive) {
 393                         /* different NAL or gateway down */
 394                         rc = -EHOSTUNREACH;
 395                         continue;
 396                 }
 397
 398                 if (ge == NULL ||
 399                     kpr_ge_isbetter (re->kpre_gateway, ge))
 400                     ge = re->kpre_gateway;
 401         }
 402
 403         if (ge != NULL) {
 404                 kpr_update_weight (ge, nob);
 405                 *gateway_nidp = ge->kpge_nid;
 406                 rc = 0;
 407         }
 408
 409         read_unlock (&kpr_rwlock);
 410
 411         /* NB can't deref 're' now; it might have been removed! */
 412
 413         CDEBUG (D_NET, "lookup "LPX64" from NAL %d: %d ("LPX64")\n",
 414                 target_nid, ne->kpne_interface.kprni_nalid, rc,
 415                 (rc == 0) ? *gateway_nidp : (ptl_nid_t)0);
 416         return (rc);
 417 }
 418
 419 kpr_nal_entry_t *
 420 kpr_find_nal_entry_locked (int nal_id)
 421 {
 422         struct list_head    *e;
 423
 424         /* Called with kpr_rwlock held */
 425
 426         list_for_each (e, &kpr_nals) {
 427                 kpr_nal_entry_t *ne = list_entry (e, kpr_nal_entry_t, kpne_list);
 428
 429                 if (nal_id != ne->kpne_interface.kprni_nalid) /* no match */
 430                         continue;
 431
 432                 return (ne);
 433         }
 434
 435         return (NULL);
 436 }
 437
 438 void
 439 kpr_forward_packet (void *arg, kpr_fwd_desc_t *fwd)
 440 {
 441         kpr_nal_entry_t     *src_ne = (kpr_nal_entry_t *)arg;
 442         ptl_nid_t            target_nid = fwd->kprfd_target_nid;
 443         int                  nob = fwd->kprfd_nob;
 444         kpr_gateway_entry_t *ge = NULL;
 445         kpr_nal_entry_t     *dst_ne = NULL;
 446         struct list_head    *e;
 447         kpr_route_entry_t   *re;
 448         kpr_nal_entry_t     *tmp_ne;
 449
 450         CDEBUG (D_NET, "forward [%p] "LPX64" from NAL %d\n", fwd,
 451                 target_nid, src_ne->kpne_interface.kprni_nalid);
 452
 453         LASSERT (nob >= sizeof (ptl_hdr_t)); /* at least got a packet header */
 454         LASSERT (nob == lib_iov_nob (fwd->kprfd_niov, fwd->kprfd_iov));
 455
 456         atomic_inc (&kpr_queue_depth);
 457         atomic_inc (&src_ne->kpne_refcount); /* source nal is busy until fwd completes */
 458
 459         kpr_fwd_packets++;                   /* (loose) stats accounting */
 460         kpr_fwd_bytes += nob;
 461
 462         if (src_ne->kpne_shutdown)           /* caller is shutting down */
 463                 goto out;
 464
 465         fwd->kprfd_router_arg = src_ne;      /* stash caller's nal entry */
 466
 467         read_lock (&kpr_rwlock);
 468
 469         /* Search routes for one that has a gateway to target_nid NOT on the caller's network */
 470
 471         list_for_each (e, &kpr_routes) {
 472                 re = list_entry (e, kpr_route_entry_t, kpre_list);
 473
 474                 if (re->kpre_lo_nid > target_nid || /* no match */
 475                     re->kpre_hi_nid < target_nid)
 476                         continue;
 477
 478                 if (re->kpre_gateway->kpge_nalid == src_ne->kpne_interface.kprni_nalid)
 479                         continue;               /* don't route to same NAL */
 480
 481                 if (!re->kpre_gateway->kpge_alive)
 482                         continue;               /* gateway is dead */
 483
 484                 tmp_ne = kpr_find_nal_entry_locked (re->kpre_gateway->kpge_nalid);
 485
 486                 if (tmp_ne == NULL ||
 487                     tmp_ne->kpne_shutdown) {
 488                         /* NAL must be registered and not shutting down */
 489                         continue;
 490                 }
 491
 492                 if (ge == NULL ||
 493                     kpr_ge_isbetter (re->kpre_gateway, ge)) {
 494                         ge = re->kpre_gateway;
 495                         dst_ne = tmp_ne;
 496                 }
 497         }
 498
 499         if (ge != NULL) {
 500                 LASSERT (dst_ne != NULL);
 501
 502                 kpr_update_weight (ge, nob);
 503
 504                 fwd->kprfd_gateway_nid = ge->kpge_nid;
 505                 atomic_inc (&dst_ne->kpne_refcount); /* dest nal is busy until fwd completes */
 506
 507                 read_unlock (&kpr_rwlock);
 508
 509                 CDEBUG (D_NET, "forward [%p] "LPX64" from NAL %d: "
 510                         "to "LPX64" on NAL %d\n",
 511                         fwd, target_nid, src_ne->kpne_interface.kprni_nalid,
 512                         fwd->kprfd_gateway_nid, dst_ne->kpne_interface.kprni_nalid);
 513
 514                 dst_ne->kpne_interface.kprni_fwd (dst_ne->kpne_interface.kprni_arg, fwd);
 515                 return;
 516         }
 517
 518         read_unlock (&kpr_rwlock);
 519  out:
 520         kpr_fwd_errors++;
 521
 522         CDEBUG (D_NET, "Failed to forward [%p] "LPX64" from NAL %d\n", fwd,
 523                 target_nid, src_ne->kpne_interface.kprni_nalid);
 524
 525         /* Can't find anywhere to forward to */
 526         (fwd->kprfd_callback)(fwd->kprfd_callback_arg, -EHOSTUNREACH);
 527
 528         atomic_dec (&kpr_queue_depth);
 529         atomic_dec (&src_ne->kpne_refcount);
 530 }
 531
 532 void
 533 kpr_complete_packet (void *arg, kpr_fwd_desc_t *fwd, int error)
 534 {
 535         kpr_nal_entry_t *dst_ne = (kpr_nal_entry_t *)arg;
 536         kpr_nal_entry_t *src_ne = (kpr_nal_entry_t *)fwd->kprfd_router_arg;
 537
 538         CDEBUG (D_NET, "complete(1) [%p] from NAL %d to NAL %d: %d\n", fwd,
 539                 src_ne->kpne_interface.kprni_nalid, dst_ne->kpne_interface.kprni_nalid, error);
 540
 541         atomic_dec (&dst_ne->kpne_refcount);    /* CAVEAT EMPTOR dst_ne can disappear now!!! */
 542
 543         (fwd->kprfd_callback)(fwd->kprfd_callback_arg, error);
 544
 545         CDEBUG (D_NET, "complete(2) [%p] from NAL %d: %d\n", fwd,
 546                 src_ne->kpne_interface.kprni_nalid, error);
 547
 548         atomic_dec (&kpr_queue_depth);
 549         atomic_dec (&src_ne->kpne_refcount);    /* CAVEAT EMPTOR src_ne can disappear now!!! */
 550 }
 551
 552 int
 553 kpr_add_route (int gateway_nalid, ptl_nid_t gateway_nid,
 554                ptl_nid_t lo_nid, ptl_nid_t hi_nid)
 555 {
 556         unsigned long        flags;
 557         struct list_head    *e;
 558         kpr_route_entry_t   *re;
 559         kpr_gateway_entry_t *ge;
 560         int                  dup = 0;
 561
 562         CDEBUG(D_NET, "Add route: %d "LPX64" : "LPX64" - "LPX64"\n",
 563                gateway_nalid, gateway_nid, lo_nid, hi_nid);
 564
 565         if (gateway_nalid == PTL_NID_ANY ||
 566             lo_nid == PTL_NID_ANY ||
 567             hi_nid == PTL_NID_ANY ||
 568             lo_nid > hi_nid)
 569                 return (-EINVAL);
 570
 571         PORTAL_ALLOC (ge, sizeof (*ge));
 572         if (ge == NULL)
 573                 return (-ENOMEM);
 574
 575         ge->kpge_nalid = gateway_nalid;
 576         ge->kpge_nid   = gateway_nid;
 577         ge->kpge_alive = 1;
 578         ge->kpge_timestamp = 0;
 579         ge->kpge_refcount = 0;
 580         atomic_set (&ge->kpge_weight, 0);
 581
 582         PORTAL_ALLOC (re, sizeof (*re));
 583         if (re == NULL)
 584                 return (-ENOMEM);
 585
 586         re->kpre_lo_nid = lo_nid;
 587         re->kpre_hi_nid = hi_nid;
 588
 589         LASSERT(!in_interrupt());
 590         write_lock_irqsave (&kpr_rwlock, flags);
 591
 592         list_for_each (e, &kpr_gateways) {
 593                 kpr_gateway_entry_t *ge2 = list_entry(e, kpr_gateway_entry_t,
 594                                                       kpge_list);
 595
 596                 if (ge2->kpge_nalid == gateway_nalid &&
 597                     ge2->kpge_nid == gateway_nid) {
 598                         PORTAL_FREE (ge, sizeof (*ge));
 599                         ge = ge2;
 600                         dup = 1;
 601                         break;
 602                 }
 603         }
 604
 605         if (!dup) {
 606                 /* Adding a new gateway... */
 607
 608                 list_add (&ge->kpge_list, &kpr_gateways);
 609
 610                 /* ...zero all gateway weights so this one doesn't have to
 611                  * play catch-up */
 612
 613                 list_for_each (e, &kpr_gateways) {
 614                         kpr_gateway_entry_t *ge2 = list_entry(e, kpr_gateway_entry_t,
 615                                                               kpge_list);
 616                         atomic_set (&ge2->kpge_weight, 0);
 617                 }
 618
 619         }
 620
 621         re->kpre_gateway = ge;
 622         ge->kpge_refcount++;
 623         list_add (&re->kpre_list, &kpr_routes);
 624
 625         write_unlock_irqrestore (&kpr_rwlock, flags);
 626         return (0);
 627 }
 628
 629 int
 630 kpr_sys_notify (int gateway_nalid, ptl_nid_t gateway_nid,
 631             int alive, time_t when)
 632 {
 633         return (kpr_do_notify (0, gateway_nalid, gateway_nid, alive, when));
 634 }
 635
 636 int
 637 kpr_del_route (int gw_nalid, ptl_nid_t gw_nid,
 638                ptl_nid_t lo, ptl_nid_t hi)
 639 {
 640         int                specific = (lo != PTL_NID_ANY);
 641         unsigned long      flags;
 642         int                rc = -ENOENT;
 643         struct list_head  *e;
 644         struct list_head  *n;
 645
 646         CDEBUG(D_NET, "Del route [%d] "LPX64" : "LPX64" - "LPX64"\n",
 647                gw_nalid, gw_nid, lo, hi);
 648
 649         LASSERT(!in_interrupt());
 650
 651         /* NB Caller may specify either all routes via the given gateway
 652          * (lo/hi == PTL_NID_ANY) or a specific route entry (lo/hi are
 653          * actual NIDs) */
 654
 655         if (specific ? (hi == PTL_NID_ANY || hi < lo) : (hi != PTL_NID_ANY))
 656                 return (-EINVAL);
 657
 658         write_lock_irqsave(&kpr_rwlock, flags);
 659
 660         list_for_each_safe (e, n, &kpr_routes) {
 661                 kpr_route_entry_t   *re = list_entry(e, kpr_route_entry_t,
 662                                                    kpre_list);
 663                 kpr_gateway_entry_t *ge = re->kpre_gateway;
 664
 665                 if (ge->kpge_nalid != gw_nalid ||
 666                     ge->kpge_nid != gw_nid ||
 667                     (specific &&
 668                      (lo != re->kpre_lo_nid || hi != re->kpre_hi_nid)))
 669                         continue;
 670
 671                 rc = 0;
 672
 673                 if (--ge->kpge_refcount == 0) {
 674                         list_del (&ge->kpge_list);
 675                         PORTAL_FREE (ge, sizeof (*ge));
 676                 }
 677
 678                 list_del (&re->kpre_list);
 679                 PORTAL_FREE(re, sizeof (*re));
 680
 681                 if (specific)
 682                         break;
 683         }
 684
 685         write_unlock_irqrestore(&kpr_rwlock, flags);
 686         return (rc);
 687 }
 688
 689 int
 690 kpr_get_route (int idx, int *gateway_nalid, ptl_nid_t *gateway_nid,
 691                ptl_nid_t *lo_nid, ptl_nid_t *hi_nid, int *alive)
 692 {
 693         struct list_head  *e;
 694
 695         read_lock(&kpr_rwlock);
 696
 697         for (e = kpr_routes.next; e != &kpr_routes; e = e->next) {
 698                 kpr_route_entry_t   *re = list_entry(e, kpr_route_entry_t,
 699                                                      kpre_list);
 700                 kpr_gateway_entry_t *ge = re->kpre_gateway;
 701
 702                 if (idx-- == 0) {
 703                         *gateway_nalid = ge->kpge_nalid;
 704                         *gateway_nid = ge->kpge_nid;
 705                         *alive = ge->kpge_alive;
 706                         *lo_nid = re->kpre_lo_nid;
 707                         *hi_nid = re->kpre_hi_nid;
 708
 709                         read_unlock(&kpr_rwlock);
 710                         return (0);
 711                 }
 712         }
 713
 714         read_unlock (&kpr_rwlock);
 715         return (-ENOENT);
 716 }
 717
 718 static void /*__exit*/
 719 kpr_finalise (void)
 720 {
 721         LASSERT (list_empty (&kpr_nals));
 722
 723         while (!list_empty (&kpr_routes)) {
 724                 kpr_route_entry_t *re = list_entry(kpr_routes.next,
 725                                                    kpr_route_entry_t,
 726                                                    kpre_list);
 727
 728                 list_del(&re->kpre_list);
 729                 PORTAL_FREE(re, sizeof (*re));
 730         }
 731
 732         kpr_proc_fini();
 733
 734         PORTAL_SYMBOL_UNREGISTER(kpr_router_interface);
 735         PORTAL_SYMBOL_UNREGISTER(kpr_control_interface);
 736
 737         CDEBUG(D_MALLOC, "kpr_finalise: kmem back to %d\n",
 738                atomic_read(&portal_kmemory));
 739 }
 740
 741 static int __init
 742 kpr_initialise (void)
 743 {
 744         CDEBUG(D_MALLOC, "kpr_initialise: kmem %d\n",
 745                atomic_read(&portal_kmemory));
 746
 747         kpr_proc_init();
 748
 749         PORTAL_SYMBOL_REGISTER(kpr_router_interface);
 750         PORTAL_SYMBOL_REGISTER(kpr_control_interface);
 751         return (0);
 752 }
 753
 754 MODULE_AUTHOR("Eric Barton");
 755 MODULE_DESCRIPTION("Kernel Portals Router v0.01");
 756 MODULE_LICENSE("GPL");
 757
 758 module_init (kpr_initialise);
 759 module_exit (kpr_finalise);
 760
 761 EXPORT_SYMBOL (kpr_control_interface);
 762 EXPORT_SYMBOL (kpr_router_interface);