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         kfree (u);
 124 }
 125
 126 void
 127 kpr_upcall (int gw_nalid, ptl_nid_t gw_nid, int alive, time_t when)
 128 {
 129         char str[PTL_NALFMT_SIZE];
 130
 131         /* May be in arbitrary context */
 132         kpr_upcall_t  *u = kmalloc (sizeof (kpr_upcall_t), GFP_ATOMIC);
 133
 134         if (u == NULL) {
 135                 CERROR ("Upcall out of memory: nal %d nid "LPX64" (%s) %s\n",
 136                         gw_nalid, gw_nid,
 137                         portals_nid2str(gw_nalid, gw_nid, str),
 138                         alive ? "up" : "down");
 139                 return;
 140         }
 141
 142         u->kpru_nal_id     = gw_nalid;
 143         u->kpru_nid        = gw_nid;
 144         u->kpru_alive      = alive;
 145         u->kpru_when       = when;
 146
 147         prepare_work (&u->kpru_tq, kpr_do_upcall, u);
 148         schedule_work (&u->kpru_tq);
 149 }
 150
 151 int
 152 kpr_do_notify (int byNal, int gateway_nalid, ptl_nid_t gateway_nid,
 153                int alive, time_t when)
 154 {
 155         unsigned long        flags;
 156         int                  found;
 157         kpr_nal_entry_t     *ne = NULL;
 158         kpr_gateway_entry_t *ge = NULL;
 159         struct timeval       now;
 160         struct list_head    *e;
 161         struct list_head    *n;
 162         char                 str[PTL_NALFMT_SIZE];
 163
 164         CDEBUG (D_NET, "%s notifying [%d] "LPX64": %s\n",
 165                 byNal ? "NAL" : "userspace",
 166                 gateway_nalid, gateway_nid, alive ? "up" : "down");
 167
 168         /* can't do predictions... */
 169         do_gettimeofday (&now);
 170         if (when > now.tv_sec) {
 171                 CWARN ("Ignoring prediction from %s of [%d] "LPX64" %s "
 172                        "%ld seconds in the future\n",
 173                        byNal ? "NAL" : "userspace",
 174                        gateway_nalid, gateway_nid,
 175                        alive ? "up" : "down",
 176                        when - now.tv_sec);
 177                 return (EINVAL);
 178         }
 179
 180         LASSERT (when <= now.tv_sec);
 181
 182         /* Serialise with lookups (i.e. write lock) */
 183         write_lock_irqsave(&kpr_rwlock, flags);
 184
 185         found = 0;
 186         list_for_each_safe (e, n, &kpr_gateways) {
 187
 188                 ge = list_entry(e, kpr_gateway_entry_t, kpge_list);
 189                 if ((gateway_nalid != 0 &&
 190                      ge->kpge_nalid != gateway_nalid) ||
 191                     ge->kpge_nid != gateway_nid)
 192                         continue;
 193
 194                 found = 1;
 195                 break;
 196         }
 197
 198         if (!found) {
 199                 /* gateway not found */
 200                 write_unlock_irqrestore(&kpr_rwlock, flags);
 201                 CDEBUG (D_NET, "Gateway not found\n");
 202                 return (0);
 203         }
 204
 205         if (when < ge->kpge_timestamp) {
 206                 /* out of date information */
 207                 write_unlock_irqrestore (&kpr_rwlock, flags);
 208                 CDEBUG (D_NET, "Out of date\n");
 209                 return (0);
 210         }
 211
 212         /* update timestamp */
 213         ge->kpge_timestamp = when;
 214
 215         if ((!ge->kpge_alive) == (!alive)) {
 216                 /* new date for old news */
 217                 write_unlock_irqrestore (&kpr_rwlock, flags);
 218                 CDEBUG (D_NET, "Old news\n");
 219                 return (0);
 220         }
 221
 222         ge->kpge_alive = alive;
 223         CDEBUG(D_NET, "set "LPX64" [%p] %d\n", gateway_nid, ge, alive);
 224
 225         if (alive) {
 226                 /* Reset all gateway weights so the newly-enabled gateway
 227                  * doesn't have to play catch-up */
 228                 list_for_each_safe (e, n, &kpr_gateways) {
 229                         kpr_gateway_entry_t *ge = list_entry(e, kpr_gateway_entry_t,
 230                                                              kpge_list);
 231                         atomic_set (&ge->kpge_weight, 0);
 232                 }
 233         }
 234
 235         found = 0;
 236         if (!byNal) {
 237                 /* userland notified me: notify NAL? */
 238                 ne = kpr_find_nal_entry_locked (ge->kpge_nalid);
 239                 if (ne != NULL) {
 240                         if (!ne->kpne_shutdown &&
 241                             ne->kpne_interface.kprni_notify != NULL) {
 242                                 /* take a ref on this NAL until notifying
 243                                  * it has completed... */
 244                                 atomic_inc (&ne->kpne_refcount);
 245                                 found = 1;
 246                         }
 247                 }
 248         }
 249
 250         write_unlock_irqrestore(&kpr_rwlock, flags);
 251
 252         if (found) {
 253                 ne->kpne_interface.kprni_notify (ne->kpne_interface.kprni_arg,
 254                                                  gateway_nid, alive);
 255                 /* 'ne' can disappear now... */
 256                 atomic_dec (&ne->kpne_refcount);
 257         }
 258
 259         if (byNal) {
 260                 /* It wasn't userland that notified me... */
 261                 CWARN ("Upcall: NAL %d NID "LPX64" (%s) is %s\n",
 262                        gateway_nalid, gateway_nid,
 263                        portals_nid2str(gateway_nalid, gateway_nid, str),
 264                        alive ? "alive" : "dead");
 265                 kpr_upcall (gateway_nalid, gateway_nid, alive, when);
 266         } else {
 267                 CDEBUG (D_NET, " NOT Doing upcall\n");
 268         }
 269
 270         return (0);
 271 }
 272
 273 void
 274 kpr_nal_notify (void *arg, ptl_nid_t peer, int alive, time_t when)
 275 {
 276         kpr_nal_entry_t *ne = (kpr_nal_entry_t *)arg;
 277
 278         kpr_do_notify (1, ne->kpne_interface.kprni_nalid, peer, alive, when);
 279 }
 280
 281 void
 282 kpr_shutdown_nal (void *arg)
 283 {
 284         unsigned long    flags;
 285         kpr_nal_entry_t *ne = (kpr_nal_entry_t *)arg;
 286
 287         CDEBUG (D_NET, "Shutting down NAL %d\n", ne->kpne_interface.kprni_nalid);
 288
 289         LASSERT (!ne->kpne_shutdown);
 290         LASSERT (!in_interrupt());
 291
 292         write_lock_irqsave (&kpr_rwlock, flags);
 293         ne->kpne_shutdown = 1;
 294         write_unlock_irqrestore (&kpr_rwlock, flags);
 295 }
 296
 297 void
 298 kpr_deregister_nal (void *arg)
 299 {
 300         unsigned long     flags;
 301         kpr_nal_entry_t  *ne = (kpr_nal_entry_t *)arg;
 302
 303         CDEBUG (D_NET, "Deregister NAL %d\n", ne->kpne_interface.kprni_nalid);
 304
 305         LASSERT (ne->kpne_shutdown);            /* caller must have issued shutdown already */
 306         LASSERT (!in_interrupt());
 307
 308         write_lock_irqsave (&kpr_rwlock, flags);
 309         list_del (&ne->kpne_list);
 310         write_unlock_irqrestore (&kpr_rwlock, flags);
 311
 312         /* Wait until all outstanding messages/notifications have completed */
 313         while (atomic_read (&ne->kpne_refcount) != 0)
 314         {
 315                 CDEBUG (D_NET, "Waiting for refcount on NAL %d to reach zero (%d)\n",
 316                         ne->kpne_interface.kprni_nalid, atomic_read (&ne->kpne_refcount));
 317
 318                 set_current_state (TASK_UNINTERRUPTIBLE);
 319                 schedule_timeout (HZ);
 320         }
 321
 322         PORTAL_FREE (ne, sizeof (*ne));
 323         PORTAL_MODULE_UNUSE;
 324 }
 325
 326 int
 327 kpr_ge_isbetter (kpr_gateway_entry_t *ge1, kpr_gateway_entry_t *ge2)
 328 {
 329         const int significant_bits = 0x00ffffff;
 330         /* We use atomic_t to record/compare route weights for
 331          * load-balancing.  Here we limit ourselves to only using
 332          * 'significant_bits' when we do an 'after' comparison */
 333
 334         int    diff = (atomic_read (&ge1->kpge_weight) -
 335                        atomic_read (&ge2->kpge_weight)) & significant_bits;
 336         int    rc = (diff > (significant_bits >> 1));
 337
 338         CDEBUG(D_NET, "[%p]"LPX64"=%d %s [%p]"LPX64"=%d\n",
 339                ge1, ge1->kpge_nid, atomic_read (&ge1->kpge_weight),
 340                rc ? ">" : "<",
 341                ge2, ge2->kpge_nid, atomic_read (&ge2->kpge_weight));
 342
 343         return (rc);
 344 }
 345
 346 void
 347 kpr_update_weight (kpr_gateway_entry_t *ge, int nob)
 348 {
 349         int weight = 1 + (nob + sizeof (ptl_hdr_t)/2)/sizeof (ptl_hdr_t);
 350
 351         /* We've chosen this route entry (i.e. gateway) to forward payload
 352          * of length 'nob'; update the route's weight to make it less
 353          * favoured.  Note that the weight is 1 plus the payload size
 354          * rounded and scaled to the portals header size, so we get better
 355          * use of the significant bits in kpge_weight. */
 356
 357         CDEBUG(D_NET, "gateway [%p]"LPX64" += %d\n", ge,
 358                ge->kpge_nid, weight);
 359
 360         atomic_add (weight, &ge->kpge_weight);
 361 }
 362
 363 int
 364 kpr_lookup_target (void *arg, ptl_nid_t target_nid, int nob,
 365                    ptl_nid_t *gateway_nidp)
 366 {
 367         kpr_nal_entry_t     *ne = (kpr_nal_entry_t *)arg;
 368         struct list_head    *e;
 369         kpr_route_entry_t   *re;
 370         kpr_gateway_entry_t *ge = NULL;
 371         int                  rc = -ENOENT;
 372
 373         /* Caller wants to know if 'target_nid' can be reached via a gateway
 374          * ON HER OWN NETWORK */
 375
 376         CDEBUG (D_NET, "lookup "LPX64" from NAL %d\n", target_nid,
 377                 ne->kpne_interface.kprni_nalid);
 378         LASSERT (!in_interrupt());
 379
 380         read_lock (&kpr_rwlock);
 381
 382         if (ne->kpne_shutdown) {        /* caller is shutting down */
 383                 read_unlock (&kpr_rwlock);
 384                 return (-ENOENT);
 385         }
 386
 387         /* Search routes for one that has a gateway to target_nid on the callers network */
 388
 389         list_for_each (e, &kpr_routes) {
 390                 re = list_entry (e, kpr_route_entry_t, kpre_list);
 391
 392                 if (re->kpre_lo_nid > target_nid ||
 393                     re->kpre_hi_nid < target_nid)
 394                         continue;
 395
 396                 /* found table entry */
 397
 398                 if (re->kpre_gateway->kpge_nalid != ne->kpne_interface.kprni_nalid ||
 399                     !re->kpre_gateway->kpge_alive) {
 400                         /* different NAL or gateway down */
 401                         rc = -EHOSTUNREACH;
 402                         continue;
 403                 }
 404
 405                 if (ge == NULL ||
 406                     kpr_ge_isbetter (re->kpre_gateway, ge))
 407                     ge = re->kpre_gateway;
 408         }
 409
 410         if (ge != NULL) {
 411                 kpr_update_weight (ge, nob);
 412                 *gateway_nidp = ge->kpge_nid;
 413                 rc = 0;
 414         }
 415
 416         read_unlock (&kpr_rwlock);
 417
 418         /* NB can't deref 're' now; it might have been removed! */
 419
 420         CDEBUG (D_NET, "lookup "LPX64" from NAL %d: %d ("LPX64")\n",
 421                 target_nid, ne->kpne_interface.kprni_nalid, rc,
 422                 (rc == 0) ? *gateway_nidp : (ptl_nid_t)0);
 423         return (rc);
 424 }
 425
 426 kpr_nal_entry_t *
 427 kpr_find_nal_entry_locked (int nal_id)
 428 {
 429         struct list_head    *e;
 430
 431         /* Called with kpr_rwlock held */
 432
 433         list_for_each (e, &kpr_nals) {
 434                 kpr_nal_entry_t *ne = list_entry (e, kpr_nal_entry_t, kpne_list);
 435
 436                 if (nal_id != ne->kpne_interface.kprni_nalid) /* no match */
 437                         continue;
 438
 439                 return (ne);
 440         }
 441
 442         return (NULL);
 443 }
 444
 445 void
 446 kpr_forward_packet (void *arg, kpr_fwd_desc_t *fwd)
 447 {
 448         kpr_nal_entry_t     *src_ne = (kpr_nal_entry_t *)arg;
 449         ptl_nid_t            target_nid = fwd->kprfd_target_nid;
 450         int                  nob = fwd->kprfd_nob;
 451         kpr_gateway_entry_t *ge = NULL;
 452         kpr_nal_entry_t     *dst_ne = NULL;
 453         struct list_head    *e;
 454         kpr_route_entry_t   *re;
 455         kpr_nal_entry_t     *tmp_ne;
 456         int                  rc;
 457
 458         CDEBUG (D_NET, "forward [%p] "LPX64" from NAL %d\n", fwd,
 459                 target_nid, src_ne->kpne_interface.kprni_nalid);
 460
 461         LASSERT (nob == lib_kiov_nob (fwd->kprfd_niov, fwd->kprfd_kiov));
 462         LASSERT (!in_interrupt());
 463
 464         read_lock (&kpr_rwlock);
 465
 466         kpr_fwd_packets++;                   /* (loose) stats accounting */
 467         kpr_fwd_bytes += nob + sizeof(ptl_hdr_t);
 468
 469         if (src_ne->kpne_shutdown) {         /* caller is shutting down */
 470                 rc = -ESHUTDOWN;
 471                 goto out;
 472         }
 473
 474         fwd->kprfd_router_arg = src_ne;      /* stash caller's nal entry */
 475
 476         /* Search routes for one that has a gateway to target_nid NOT on the caller's network */
 477
 478         list_for_each (e, &kpr_routes) {
 479                 re = list_entry (e, kpr_route_entry_t, kpre_list);
 480
 481                 if (re->kpre_lo_nid > target_nid || /* no match */
 482                     re->kpre_hi_nid < target_nid)
 483                         continue;
 484
 485                 if (re->kpre_gateway->kpge_nalid == src_ne->kpne_interface.kprni_nalid)
 486                         continue;               /* don't route to same NAL */
 487
 488                 if (!re->kpre_gateway->kpge_alive)
 489                         continue;               /* gateway is dead */
 490
 491                 tmp_ne = kpr_find_nal_entry_locked (re->kpre_gateway->kpge_nalid);
 492
 493                 if (tmp_ne == NULL ||
 494                     tmp_ne->kpne_shutdown) {
 495                         /* NAL must be registered and not shutting down */
 496                         continue;
 497                 }
 498
 499                 if (ge == NULL ||
 500                     kpr_ge_isbetter (re->kpre_gateway, ge)) {
 501                         ge = re->kpre_gateway;
 502                         dst_ne = tmp_ne;
 503                 }
 504         }
 505
 506         if (ge != NULL) {
 507                 LASSERT (dst_ne != NULL);
 508
 509                 kpr_update_weight (ge, nob);
 510
 511                 fwd->kprfd_gateway_nid = ge->kpge_nid;
 512                 atomic_inc (&src_ne->kpne_refcount); /* source and dest nals are */
 513                 atomic_inc (&dst_ne->kpne_refcount); /* busy until fwd completes */
 514                 atomic_inc (&kpr_queue_depth);
 515
 516                 read_unlock (&kpr_rwlock);
 517
 518                 CDEBUG (D_NET, "forward [%p] "LPX64" from NAL %d: "
 519                         "to "LPX64" on NAL %d\n",
 520                         fwd, target_nid, src_ne->kpne_interface.kprni_nalid,
 521                         fwd->kprfd_gateway_nid, dst_ne->kpne_interface.kprni_nalid);
 522
 523                 dst_ne->kpne_interface.kprni_fwd (dst_ne->kpne_interface.kprni_arg, fwd);
 524                 return;
 525         }
 526
 527         rc = -EHOSTUNREACH;
 528  out:
 529         kpr_fwd_errors++;
 530
 531         CDEBUG (D_NET, "Failed to forward [%p] "LPX64" from NAL %d: %d\n",
 532                 fwd, target_nid, src_ne->kpne_interface.kprni_nalid, rc);
 533
 534         (fwd->kprfd_callback)(fwd->kprfd_callback_arg, rc);
 535
 536         read_unlock (&kpr_rwlock);
 537 }
 538
 539 void
 540 kpr_complete_packet (void *arg, kpr_fwd_desc_t *fwd, int error)
 541 {
 542         kpr_nal_entry_t *dst_ne = (kpr_nal_entry_t *)arg;
 543         kpr_nal_entry_t *src_ne = (kpr_nal_entry_t *)fwd->kprfd_router_arg;
 544
 545         CDEBUG (D_NET, "complete(1) [%p] from NAL %d to NAL %d: %d\n", fwd,
 546                 src_ne->kpne_interface.kprni_nalid, dst_ne->kpne_interface.kprni_nalid, error);
 547
 548         atomic_dec (&dst_ne->kpne_refcount);    /* CAVEAT EMPTOR dst_ne can disappear now!!! */
 549
 550         (fwd->kprfd_callback)(fwd->kprfd_callback_arg, error);
 551
 552         CDEBUG (D_NET, "complete(2) [%p] from NAL %d: %d\n", fwd,
 553                 src_ne->kpne_interface.kprni_nalid, error);
 554
 555         atomic_dec (&kpr_queue_depth);
 556         atomic_dec (&src_ne->kpne_refcount);    /* CAVEAT EMPTOR src_ne can disappear now!!! */
 557 }
 558
 559 int
 560 kpr_add_route (int gateway_nalid, ptl_nid_t gateway_nid,
 561                ptl_nid_t lo_nid, ptl_nid_t hi_nid)
 562 {
 563         unsigned long        flags;
 564         struct list_head    *e;
 565         kpr_route_entry_t   *re;
 566         kpr_gateway_entry_t *ge;
 567         int                  dup = 0;
 568
 569         CDEBUG(D_NET, "Add route: %d "LPX64" : "LPX64" - "LPX64"\n",
 570                gateway_nalid, gateway_nid, lo_nid, hi_nid);
 571
 572         if (gateway_nalid == PTL_NID_ANY ||
 573             lo_nid == PTL_NID_ANY ||
 574             hi_nid == PTL_NID_ANY ||
 575             lo_nid > hi_nid)
 576                 return (-EINVAL);
 577
 578         PORTAL_ALLOC (ge, sizeof (*ge));
 579         if (ge == NULL)
 580                 return (-ENOMEM);
 581
 582         ge->kpge_nalid = gateway_nalid;
 583         ge->kpge_nid   = gateway_nid;
 584         ge->kpge_alive = 1;
 585         ge->kpge_timestamp = 0;
 586         ge->kpge_refcount = 0;
 587         atomic_set (&ge->kpge_weight, 0);
 588
 589         PORTAL_ALLOC (re, sizeof (*re));
 590         if (re == NULL) {
 591                 PORTAL_FREE (ge, sizeof (*ge));
 592                 return (-ENOMEM);
 593         }
 594
 595         re->kpre_lo_nid = lo_nid;
 596         re->kpre_hi_nid = hi_nid;
 597
 598         LASSERT(!in_interrupt());
 599         write_lock_irqsave (&kpr_rwlock, flags);
 600
 601         list_for_each (e, &kpr_gateways) {
 602                 kpr_gateway_entry_t *ge2 = list_entry(e, kpr_gateway_entry_t,
 603                                                       kpge_list);
 604
 605                 if (ge2->kpge_nalid == gateway_nalid &&
 606                     ge2->kpge_nid == gateway_nid) {
 607                         PORTAL_FREE (ge, sizeof (*ge));
 608                         ge = ge2;
 609                         dup = 1;
 610                         break;
 611                 }
 612         }
 613
 614         if (!dup) {
 615                 /* Adding a new gateway... */
 616
 617                 list_add (&ge->kpge_list, &kpr_gateways);
 618
 619                 /* ...zero all gateway weights so this one doesn't have to
 620                  * play catch-up */
 621
 622                 list_for_each (e, &kpr_gateways) {
 623                         kpr_gateway_entry_t *ge2 = list_entry(e, kpr_gateway_entry_t,
 624                                                               kpge_list);
 625                         atomic_set (&ge2->kpge_weight, 0);
 626                 }
 627
 628         }
 629
 630         re->kpre_gateway = ge;
 631         ge->kpge_refcount++;
 632         list_add (&re->kpre_list, &kpr_routes);
 633
 634         write_unlock_irqrestore (&kpr_rwlock, flags);
 635         return (0);
 636 }
 637
 638 int
 639 kpr_sys_notify (int gateway_nalid, ptl_nid_t gateway_nid,
 640             int alive, time_t when)
 641 {
 642         return (kpr_do_notify (0, gateway_nalid, gateway_nid, alive, when));
 643 }
 644
 645 int
 646 kpr_del_route (int gw_nalid, ptl_nid_t gw_nid,
 647                ptl_nid_t lo, ptl_nid_t hi)
 648 {
 649         int                specific = (lo != PTL_NID_ANY);
 650         unsigned long      flags;
 651         int                rc = -ENOENT;
 652         struct list_head  *e;
 653         struct list_head  *n;
 654
 655         CDEBUG(D_NET, "Del route [%d] "LPX64" : "LPX64" - "LPX64"\n",
 656                gw_nalid, gw_nid, lo, hi);
 657
 658         LASSERT(!in_interrupt());
 659
 660         /* NB Caller may specify either all routes via the given gateway
 661          * (lo/hi == PTL_NID_ANY) or a specific route entry (lo/hi are
 662          * actual NIDs) */
 663
 664         if (specific ? (hi == PTL_NID_ANY || hi < lo) : (hi != PTL_NID_ANY))
 665                 return (-EINVAL);
 666
 667         write_lock_irqsave(&kpr_rwlock, flags);
 668
 669         list_for_each_safe (e, n, &kpr_routes) {
 670                 kpr_route_entry_t   *re = list_entry(e, kpr_route_entry_t,
 671                                                    kpre_list);
 672                 kpr_gateway_entry_t *ge = re->kpre_gateway;
 673
 674                 if (ge->kpge_nalid != gw_nalid ||
 675                     ge->kpge_nid != gw_nid ||
 676                     (specific &&
 677                      (lo != re->kpre_lo_nid || hi != re->kpre_hi_nid)))
 678                         continue;
 679
 680                 rc = 0;
 681
 682                 if (--ge->kpge_refcount == 0) {
 683                         list_del (&ge->kpge_list);
 684                         PORTAL_FREE (ge, sizeof (*ge));
 685                 }
 686
 687                 list_del (&re->kpre_list);
 688                 PORTAL_FREE(re, sizeof (*re));
 689
 690                 if (specific)
 691                         break;
 692         }
 693
 694         write_unlock_irqrestore(&kpr_rwlock, flags);
 695         return (rc);
 696 }
 697
 698 int
 699 kpr_get_route (int idx, int *gateway_nalid, ptl_nid_t *gateway_nid,
 700                ptl_nid_t *lo_nid, ptl_nid_t *hi_nid, int *alive)
 701 {
 702         struct list_head  *e;
 703
 704         LASSERT (!in_interrupt());
 705         read_lock(&kpr_rwlock);
 706
 707         for (e = kpr_routes.next; e != &kpr_routes; e = e->next) {
 708                 kpr_route_entry_t   *re = list_entry(e, kpr_route_entry_t,
 709                                                      kpre_list);
 710                 kpr_gateway_entry_t *ge = re->kpre_gateway;
 711
 712                 if (idx-- == 0) {
 713                         *gateway_nalid = ge->kpge_nalid;
 714                         *gateway_nid = ge->kpge_nid;
 715                         *alive = ge->kpge_alive;
 716                         *lo_nid = re->kpre_lo_nid;
 717                         *hi_nid = re->kpre_hi_nid;
 718
 719                         read_unlock(&kpr_rwlock);
 720                         return (0);
 721                 }
 722         }
 723
 724         read_unlock (&kpr_rwlock);
 725         return (-ENOENT);
 726 }
 727
 728 static void /*__exit*/
 729 kpr_finalise (void)
 730 {
 731         LASSERT (list_empty (&kpr_nals));
 732
 733         while (!list_empty (&kpr_routes)) {
 734                 kpr_route_entry_t *re = list_entry(kpr_routes.next,
 735                                                    kpr_route_entry_t,
 736                                                    kpre_list);
 737
 738                 list_del(&re->kpre_list);
 739                 PORTAL_FREE(re, sizeof (*re));
 740         }
 741
 742         kpr_proc_fini();
 743
 744         PORTAL_SYMBOL_UNREGISTER(kpr_router_interface);
 745         PORTAL_SYMBOL_UNREGISTER(kpr_control_interface);
 746
 747         CDEBUG(D_MALLOC, "kpr_finalise: kmem back to %d\n",
 748                atomic_read(&portal_kmemory));
 749 }
 750
 751 static int __init
 752 kpr_initialise (void)
 753 {
 754         CDEBUG(D_MALLOC, "kpr_initialise: kmem %d\n",
 755                atomic_read(&portal_kmemory));
 756
 757         kpr_proc_init();
 758
 759         PORTAL_SYMBOL_REGISTER(kpr_router_interface);
 760         PORTAL_SYMBOL_REGISTER(kpr_control_interface);
 761         return (0);
 762 }
 763
 764 MODULE_AUTHOR("Eric Barton");
 765 MODULE_DESCRIPTION("Kernel Portals Router v0.01");
 766 MODULE_LICENSE("GPL");
 767
 768 module_init (kpr_initialise);
 769 module_exit (kpr_finalise);
 770
 771 EXPORT_SYMBOL (kpr_control_interface);
 772 EXPORT_SYMBOL (kpr_router_interface);