sbin/hammer2/msg_lnk.c

   1 /*
   2  * Copyright (c) 2012 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@dragonflybsd.org>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34 /*
  35  * LNK_SPAN PROTOCOL SUPPORT FUNCTIONS
  36  *
  37  * This code supports the LNK_SPAN protocol.  Essentially all PFS's
  38  * clients and services rendezvous with the userland hammer2 service and
  39  * open LNK_SPAN transactions using a message header linkid of 0,
  40  * registering any PFS's they have connectivity to with us.
  41  *
  42  * --
  43  *
  44  * Each registration maintains its own open LNK_SPAN message transaction.
  45  * The SPANs are collected, aggregated, and retransmitted over available
  46  * connections through the maintainance of additional LNK_SPAN message
  47  * transactions on each link.
  48  *
  49  * The msgid for each active LNK_SPAN transaction we receive allows us to
  50  * send a message to the target PFS (which might be one of many belonging
  51  * to the same cluster), by specifying that msgid as the linkid in any
  52  * message we send to the target PFS.
  53  *
  54  * Similarly the msgid we allocate for any LNK_SPAN transaction we transmit
  55  * (and remember we will maintain multiple open LNK_SPAN transactions on
  56  * each connection representing the topology span, so every node sees every
  57  * other node as a separate open transaction).  So, similarly the msgid for
  58  * these active transactions which we initiated can be used by the other
  59  * end to route messages through us to another node, ultimately winding up
  60  * at the identified hammer2 PFS.  We have to adjust the spanid in the message
  61  * header at each hop to be representative of the outgoing LNK_SPAN we
  62  * are forwarding the message through.
  63  *
  64  * --
  65  *
  66  * If we were to retransmit every LNK_SPAN transaction we receive it would
  67  * create a huge mess, so we have to aggregate all received LNK_SPAN
  68  * transactions, sort them by the fsid (the cluster) and sub-sort them by
  69  * the pfs_fsid (individual nodes in the cluster), and only retransmit
  70  * (create outgoing transactions) for a subset of the nearest distance-hops
  71  * for each individual node.
  72  *
  73  * The higher level protocols can then issue transactions to the nodes making
  74  * up a cluster to perform all actions required.
  75  *
  76  * --
  77  *
  78  * Since this is a large topology and a spanning tree protocol, links can
  79  * go up and down all the time.  Any time a link goes down its transaction
  80  * is closed.  The transaction has to be closed on both ends before we can
  81  * delete (and potentially reuse) the related spanid.  The LNK_SPAN being
  82  * closed may have been propagated out to other connections and those related
  83  * LNK_SPANs are also closed.  Ultimately all routes via the lost LNK_SPAN
  84  * go away, ultimately reaching all sources and all targets.
  85  *
  86  * Any messages in-transit using a route that goes away will be thrown away.
  87  * Open transactions are only tracked at the two end-points.  When a link
  88  * failure propagates to an end-point the related open transactions lose
  89  * their spanid and are automatically aborted.
  90  *
  91  * It is important to note that internal route nodes cannot just associate
  92  * a lost LNK_SPAN transaction with another route to the same destination.
  93  * Message transactions MUST be serialized and MUST be ordered.  All messages
  94  * for a transaction must run over the same route.  So if the route used by
  95  * an active transaction is lost, the related messages will be fully aborted
  96  * and the higher protocol levels will retry as appropriate.
  97  *
  98  * FULLY ABORTING A ROUTED MESSAGE is handled via link-failure propagation
  99  * back to the originator.  Only the originator keeps tracks of a message.
 100  * Routers just pass it through.  If a route is lost during transit the
 101  * message is simply thrown away.
 102  *
 103  * It is also important to note that several paths to the same PFS can be
 104  * propagated along the same link, which allows concurrency and even
 105  * redundancy over several network interfaces or via different routes through
 106  * the topology.  Any given transaction will use only a single route but busy
 107  * servers will often have hundreds of transactions active simultaniously,
 108  * so having multiple active paths through the network topology for A<->B
 109  * will improve performance.
 110  *
 111  * --
 112  *
 113  * Most protocols consolidate operations rather than simply relaying them.
 114  * This is particularly true of LEAF protocols (such as strict HAMMER2
 115  * clients), of which there can be millions connecting into the cluster at
 116  * various points.  The SPAN protocol is not used for these LEAF elements.
 117  *
 118  * Instead the primary service they connect to implements a proxy for the
 119  * client protocols so the core topology only has to propagate a couple of
 120  * LNK_SPANs and not millions.  LNK_SPANs are meant to be used only for
 121  * core master nodes and satellite slaves and cache nodes.
 122  */
 123
 124 #include "hammer2.h"
 125
 126 /*
 127  * Maximum spanning tree distance.  This has the practical effect of
 128  * stopping tail-chasing closed loops when a feeder span is lost.
 129  */
 130 #define HAMMER2_SPAN_MAXDIST    16
 131
 132 /*
 133  * RED-BLACK TREE DEFINITIONS
 134  *
 135  * We need to track:
 136  *
 137  * (1) shared fsid's (a cluster).
 138  * (2) unique fsid's (a node in a cluster) <--- LNK_SPAN transactions.
 139  *
 140  * We need to aggegate all active LNK_SPANs, aggregate, and create our own
 141  * outgoing LNK_SPAN transactions on each of our connections representing
 142  * the aggregated state.
 143  *
 144  * h2span_connect       - list of iocom connections who wish to receive SPAN
 145  *                        propagation from other connections.  Might contain
 146  *                        a filter string.  Only iocom's with an open
 147  *                        LNK_CONN transactions are applicable for SPAN
 148  *                        propagation.
 149  *
 150  * h2span_relay         - List of links relayed (via SPAN).  Essentially
 151  *                        each relay structure represents a LNK_SPAN
 152  *                        transaction that we initiated, verses h2span_link
 153  *                        which is a LNK_SPAN transaction that we received.
 154  *
 155  * --
 156  *
 157  * h2span_cluster       - Organizes the shared fsid's.  One structure for
 158  *                        each cluster.
 159  *
 160  * h2span_node          - Organizes the nodes in a cluster.  One structure
 161  *                        for each unique {cluster,node}, aka {fsid, pfs_fsid}.
 162  *
 163  * h2span_link          - Organizes all incoming and outgoing LNK_SPAN message
 164  *                        transactions related to a node.
 165  *
 166  *                        One h2span_link structure for each incoming LNK_SPAN
 167  *                        transaction.  Links selected for propagation back
 168  *                        out are also where the outgoing LNK_SPAN messages
 169  *                        are indexed into (so we can propagate changes).
 170  *
 171  *                        The h2span_link's use a red-black tree to sort the
 172  *                        distance hop metric for the incoming LNK_SPAN.  We
 173  *                        then select the top N for outgoing.  When the
 174  *                        topology changes the top N may also change and cause
 175  *                        new outgoing LNK_SPAN transactions to be opened
 176  *                        and less desireable ones to be closed, causing
 177  *                        transactional aborts within the message flow in
 178  *                        the process.
 179  *
 180  * Also note            - All outgoing LNK_SPAN message transactions are also
 181  *                        entered into a red-black tree for use by the routing
 182  *                        function.  This is handled by msg.c in the state
 183  *                        code, not here.
 184  */
 185
 186 struct h2span_link;
 187 struct h2span_relay;
 188 TAILQ_HEAD(h2span_media_queue, h2span_media);
 189 TAILQ_HEAD(h2span_connect_queue, h2span_connect);
 190 TAILQ_HEAD(h2span_relay_queue, h2span_relay);
 191
 192 RB_HEAD(h2span_cluster_tree, h2span_cluster);
 193 RB_HEAD(h2span_node_tree, h2span_node);
 194 RB_HEAD(h2span_link_tree, h2span_link);
 195 RB_HEAD(h2span_relay_tree, h2span_relay);
 196
 197 /*
 198  * This represents a media
 199  */
 200 struct h2span_media {
 201         TAILQ_ENTRY(h2span_media) entry;
 202         uuid_t  mediaid;
 203         int     refs;
 204         struct h2span_media_config {
 205                 hammer2_copy_data_t     copy_run;
 206                 hammer2_copy_data_t     copy_pend;
 207                 pthread_t               thread;
 208                 pthread_cond_t          cond;
 209                 int                     ctl;
 210                 int                     fd;
 211                 hammer2_iocom_t         iocom;
 212                 pthread_t               iocom_thread;
 213                 enum { H2MC_STOPPED, H2MC_CONNECT, H2MC_RUNNING } state;
 214         } config[HAMMER2_COPYID_COUNT];
 215 };
 216
 217 typedef struct h2span_media_config h2span_media_config_t;
 218
 219 #define H2CONFCTL_STOP          0x00000001
 220 #define H2CONFCTL_UPDATE        0x00000002
 221
 222 /*
 223  * Received LNK_CONN transaction enables SPAN protocol over connection.
 224  * (may contain filter).  Typically one for each mount and several may
 225  * share the same media.
 226  */
 227 struct h2span_connect {
 228         TAILQ_ENTRY(h2span_connect) entry;
 229         struct h2span_relay_tree tree;
 230         struct h2span_media *media;
 231         hammer2_state_t *state;
 232 };
 233
 234 /*
 235  * All received LNK_SPANs are organized by cluster (pfs_clid),
 236  * node (pfs_fsid), and link (received LNK_SPAN transaction).
 237  */
 238 struct h2span_cluster {
 239         RB_ENTRY(h2span_cluster) rbnode;
 240         struct h2span_node_tree tree;
 241         uuid_t  pfs_clid;               /* shared fsid */
 242         int     refs;                   /* prevents destruction */
 243 };
 244
 245 struct h2span_node {
 246         RB_ENTRY(h2span_node) rbnode;
 247         struct h2span_link_tree tree;
 248         struct h2span_cluster *cls;
 249         uuid_t  pfs_fsid;               /* unique fsid */
 250         char label[64];
 251 };
 252
 253 struct h2span_link {
 254         RB_ENTRY(h2span_link) rbnode;
 255         hammer2_state_t *state;         /* state<->link */
 256         struct h2span_node *node;       /* related node */
 257         int32_t dist;
 258         struct h2span_relay_queue relayq; /* relay out */
 259         struct hammer2_router *router;  /* route out this link */
 260 };
 261
 262 /*
 263  * Any LNK_SPAN transactions we receive which are relayed out other
 264  * connections utilize this structure to track the LNK_SPAN transaction
 265  * we initiate on the other connections, if selected for relay.
 266  *
 267  * In many respects this is the core of the protocol... actually figuring
 268  * out what LNK_SPANs to relay.  The spanid used for relaying is the
 269  * address of the 'state' structure, which is why h2span_relay has to
 270  * be entered into a RB-TREE based at h2span_connect (so we can look
 271  * up the spanid to validate it).
 272  *
 273  * NOTE: Messages can be received via the LNK_SPAN transaction the
 274  *       relay maintains, and can be replied via relay->router, but
 275  *       messages are NOT initiated via a relay.  Messages are initiated
 276  *       via incoming links (h2span_link's).
 277  *
 278  *       relay->link represents the link being relayed, NOT the LNK_SPAN
 279  *       transaction the relay is holding open.
 280  */
 281 struct h2span_relay {
 282         RB_ENTRY(h2span_relay) rbnode;  /* from h2span_connect */
 283         TAILQ_ENTRY(h2span_relay) entry; /* from link */
 284         struct h2span_connect *conn;
 285         hammer2_state_t *state;         /* transmitted LNK_SPAN */
 286         struct h2span_link *link;       /* LNK_SPAN being relayed */
 287         struct hammer2_router   *router;/* route out this relay */
 288 };
 289
 290
 291 typedef struct h2span_media h2span_media_t;
 292 typedef struct h2span_connect h2span_connect_t;
 293 typedef struct h2span_cluster h2span_cluster_t;
 294 typedef struct h2span_node h2span_node_t;
 295 typedef struct h2span_link h2span_link_t;
 296 typedef struct h2span_relay h2span_relay_t;
 297
 298 static
 299 int
 300 h2span_cluster_cmp(h2span_cluster_t *cls1, h2span_cluster_t *cls2)
 301 {
 302         return(uuid_compare(&cls1->pfs_clid, &cls2->pfs_clid, NULL));
 303 }
 304
 305 static
 306 int
 307 h2span_node_cmp(h2span_node_t *node1, h2span_node_t *node2)
 308 {
 309         return(uuid_compare(&node1->pfs_fsid, &node2->pfs_fsid, NULL));
 310 }
 311
 312 /*
 313  * Sort/subsort must match h2span_relay_cmp() under any given node
 314  * to make the aggregation algorithm easier, so the best links are
 315  * in the same sorted order as the best relays.
 316  *
 317  * NOTE: We cannot use link*->state->msgid because this msgid is created
 318  *       by each remote host and thus might wind up being the same.
 319  */
 320 static
 321 int
 322 h2span_link_cmp(h2span_link_t *link1, h2span_link_t *link2)
 323 {
 324         if (link1->dist < link2->dist)
 325                 return(-1);
 326         if (link1->dist > link2->dist)
 327                 return(1);
 328 #if 1
 329         if ((uintptr_t)link1->state < (uintptr_t)link2->state)
 330                 return(-1);
 331         if ((uintptr_t)link1->state > (uintptr_t)link2->state)
 332                 return(1);
 333 #else
 334         if (link1->state->msgid < link2->state->msgid)
 335                 return(-1);
 336         if (link1->state->msgid > link2->state->msgid)
 337                 return(1);
 338 #endif
 339         return(0);
 340 }
 341
 342 /*
 343  * Relay entries are sorted by node, subsorted by distance and link
 344  * address (so we can match up the conn->tree relay topology with
 345  * a node's link topology).
 346  */
 347 static
 348 int
 349 h2span_relay_cmp(h2span_relay_t *relay1, h2span_relay_t *relay2)
 350 {
 351         h2span_link_t *link1 = relay1->link;
 352         h2span_link_t *link2 = relay2->link;
 353
 354         if ((intptr_t)link1->node < (intptr_t)link2->node)
 355                 return(-1);
 356         if ((intptr_t)link1->node > (intptr_t)link2->node)
 357                 return(1);
 358         if (link1->dist < link2->dist)
 359                 return(-1);
 360         if (link1->dist > link2->dist)
 361                 return(1);
 362 #if 1
 363         if ((uintptr_t)link1->state < (uintptr_t)link2->state)
 364                 return(-1);
 365         if ((uintptr_t)link1->state > (uintptr_t)link2->state)
 366                 return(1);
 367 #else
 368         if (link1->state->msgid < link2->state->msgid)
 369                 return(-1);
 370         if (link1->state->msgid > link2->state->msgid)
 371                 return(1);
 372 #endif
 373         return(0);
 374 }
 375
 376 RB_PROTOTYPE_STATIC(h2span_cluster_tree, h2span_cluster,
 377              rbnode, h2span_cluster_cmp);
 378 RB_PROTOTYPE_STATIC(h2span_node_tree, h2span_node,
 379              rbnode, h2span_node_cmp);
 380 RB_PROTOTYPE_STATIC(h2span_link_tree, h2span_link,
 381              rbnode, h2span_link_cmp);
 382 RB_PROTOTYPE_STATIC(h2span_relay_tree, h2span_relay,
 383              rbnode, h2span_relay_cmp);
 384
 385 RB_GENERATE_STATIC(h2span_cluster_tree, h2span_cluster,
 386              rbnode, h2span_cluster_cmp);
 387 RB_GENERATE_STATIC(h2span_node_tree, h2span_node,
 388              rbnode, h2span_node_cmp);
 389 RB_GENERATE_STATIC(h2span_link_tree, h2span_link,
 390              rbnode, h2span_link_cmp);
 391 RB_GENERATE_STATIC(h2span_relay_tree, h2span_relay,
 392              rbnode, h2span_relay_cmp);
 393
 394 /*
 395  * Global mutex protects cluster_tree lookups, connq, mediaq.
 396  */
 397 static pthread_mutex_t cluster_mtx;
 398 static struct h2span_cluster_tree cluster_tree = RB_INITIALIZER(cluster_tree);
 399 static struct h2span_connect_queue connq = TAILQ_HEAD_INITIALIZER(connq);
 400 static struct h2span_media_queue mediaq = TAILQ_HEAD_INITIALIZER(mediaq);
 401
 402 static void hammer2_lnk_span(hammer2_msg_t *msg);
 403 static void hammer2_lnk_conn(hammer2_msg_t *msg);
 404 static void hammer2_lnk_relay(hammer2_msg_t *msg);
 405 static void hammer2_relay_scan(h2span_connect_t *conn, h2span_node_t *node);
 406 static void hammer2_relay_delete(h2span_relay_t *relay);
 407
 408 static void *hammer2_volconf_thread(void *info);
 409 static void hammer2_volconf_stop(h2span_media_config_t *conf);
 410 static void hammer2_volconf_start(h2span_media_config_t *conf,
 411                                 const char *hostname);
 412
 413 void
 414 hammer2_msg_lnk_signal(hammer2_router_t *router __unused)
 415 {
 416         pthread_mutex_lock(&cluster_mtx);
 417         hammer2_relay_scan(NULL, NULL);
 418         pthread_mutex_unlock(&cluster_mtx);
 419 }
 420
 421 /*
 422  * Receive a HAMMER2_MSG_PROTO_LNK message.  This only called for
 423  * one-way and opening-transactions since state->func will be assigned
 424  * in all other cases.
 425  */
 426 void
 427 hammer2_msg_lnk(hammer2_msg_t *msg)
 428 {
 429         switch(msg->any.head.cmd & HAMMER2_MSGF_BASECMDMASK) {
 430         case HAMMER2_LNK_CONN:
 431                 hammer2_lnk_conn(msg);
 432                 break;
 433         case HAMMER2_LNK_SPAN:
 434                 hammer2_lnk_span(msg);
 435                 break;
 436         default:
 437                 fprintf(stderr,
 438                         "MSG_PROTO_LNK: Unknown msg %08x\n", msg->any.head.cmd);
 439                 hammer2_msg_reply(msg, HAMMER2_MSG_ERR_NOSUPP);
 440                 /* state invalid after reply */
 441                 break;
 442         }
 443 }
 444
 445 void
 446 hammer2_lnk_conn(hammer2_msg_t *msg)
 447 {
 448         hammer2_state_t *state = msg->state;
 449         h2span_media_t *media;
 450         h2span_media_config_t *conf;
 451         h2span_connect_t *conn;
 452         h2span_relay_t *relay;
 453         char *alloc = NULL;
 454         int i;
 455
 456         pthread_mutex_lock(&cluster_mtx);
 457
 458         switch(msg->any.head.cmd & HAMMER2_MSGF_TRANSMASK) {
 459         case HAMMER2_LNK_CONN | HAMMER2_MSGF_CREATE:
 460         case HAMMER2_LNK_CONN | HAMMER2_MSGF_CREATE | HAMMER2_MSGF_DELETE:
 461                 /*
 462                  * On transaction start we allocate a new h2span_connect and
 463                  * acknowledge the request, leaving the transaction open.
 464                  * We then relay priority-selected SPANs.
 465                  */
 466                 fprintf(stderr, "LNK_CONN(%08x): %s/%s\n",
 467                         (uint32_t)msg->any.head.msgid,
 468                         hammer2_uuid_to_str(&msg->any.lnk_conn.pfs_clid,
 469                                             &alloc),
 470                         msg->any.lnk_conn.label);
 471                 free(alloc);
 472
 473                 conn = hammer2_alloc(sizeof(*conn));
 474
 475                 RB_INIT(&conn->tree);
 476                 conn->state = state;
 477                 state->func = hammer2_lnk_conn;
 478                 state->any.conn = conn;
 479                 TAILQ_INSERT_TAIL(&connq, conn, entry);
 480
 481                 /*
 482                  * Set up media
 483                  */
 484                 TAILQ_FOREACH(media, &mediaq, entry) {
 485                         if (uuid_compare(&msg->any.lnk_conn.mediaid,
 486                                          &media->mediaid, NULL) == 0) {
 487                                 break;
 488                         }
 489                 }
 490                 if (media == NULL) {
 491                         media = hammer2_alloc(sizeof(*media));
 492                         media->mediaid = msg->any.lnk_conn.mediaid;
 493                         TAILQ_INSERT_TAIL(&mediaq, media, entry);
 494                 }
 495                 conn->media = media;
 496                 ++media->refs;
 497
 498                 if ((msg->any.head.cmd & HAMMER2_MSGF_DELETE) == 0) {
 499                         hammer2_msg_result(msg, 0);
 500                         hammer2_router_signal(msg->router);
 501                         break;
 502                 }
 503                 /* FALL THROUGH */
 504         case HAMMER2_LNK_CONN | HAMMER2_MSGF_DELETE:
 505         case HAMMER2_LNK_ERROR | HAMMER2_MSGF_DELETE:
 506 deleteconn:
 507                 /*
 508                  * On transaction terminate we clean out our h2span_connect
 509                  * and acknowledge the request, closing the transaction.
 510                  */
 511                 fprintf(stderr, "LNK_CONN: Terminated\n");
 512                 conn = state->any.conn;
 513                 assert(conn);
 514
 515                 /*
 516                  * Clean out the media structure. If refs drops to zero we
 517                  * also clean out the media config threads.  These threads
 518                  * maintain span connections to other hammer2 service daemons.
 519                  */
 520                 media = conn->media;
 521                 if (--media->refs == 0) {
 522                         fprintf(stderr, "Shutting down media spans\n");
 523                         for (i = 0; i < HAMMER2_COPYID_COUNT; ++i) {
 524                                 conf = &media->config[i];
 525
 526                                 if (conf->thread == NULL)
 527                                         continue;
 528                                 conf->ctl = H2CONFCTL_STOP;
 529                                 pthread_cond_signal(&conf->cond);
 530                         }
 531                         for (i = 0; i < HAMMER2_COPYID_COUNT; ++i) {
 532                                 conf = &media->config[i];
 533
 534                                 if (conf->thread == NULL)
 535                                         continue;
 536                                 pthread_mutex_unlock(&cluster_mtx);
 537                                 pthread_join(conf->thread, NULL);
 538                                 pthread_mutex_lock(&cluster_mtx);
 539                                 conf->thread = NULL;
 540                                 pthread_cond_destroy(&conf->cond);
 541                         }
 542                         fprintf(stderr, "Media shutdown complete\n");
 543                         TAILQ_REMOVE(&mediaq, media, entry);
 544                         hammer2_free(media);
 545                 }
 546
 547                 /*
 548                  * Clean out all relays.  This requires terminating each
 549                  * relay transaction.
 550                  */
 551                 while ((relay = RB_ROOT(&conn->tree)) != NULL) {
 552                         hammer2_relay_delete(relay);
 553                 }
 554
 555                 /*
 556                  * Clean out conn
 557                  */
 558                 conn->media = NULL;
 559                 conn->state = NULL;
 560                 msg->state->any.conn = NULL;
 561                 TAILQ_REMOVE(&connq, conn, entry);
 562                 hammer2_free(conn);
 563
 564                 hammer2_msg_reply(msg, 0);
 565                 /* state invalid after reply */
 566                 break;
 567         case HAMMER2_LNK_VOLCONF:
 568                 /*
 569                  * One-way volume-configuration message is transmitted
 570                  * over the open LNK_CONN transaction.
 571                  */
 572                 fprintf(stderr, "RECEIVED VOLCONF\n");
 573                 if (msg->any.lnk_volconf.index < 0 ||
 574                     msg->any.lnk_volconf.index >= HAMMER2_COPYID_COUNT) {
 575                         fprintf(stderr, "VOLCONF: ILLEGAL INDEX %d\n",
 576                                 msg->any.lnk_volconf.index);
 577                         break;
 578                 }
 579                 if (msg->any.lnk_volconf.copy.path[sizeof(msg->any.lnk_volconf.copy.path) - 1] != 0 ||
 580                     msg->any.lnk_volconf.copy.path[0] == 0) {
 581                         fprintf(stderr, "VOLCONF: ILLEGAL PATH %d\n",
 582                                 msg->any.lnk_volconf.index);
 583                         break;
 584                 }
 585                 conn = msg->state->any.conn;
 586                 if (conn == NULL) {
 587                         fprintf(stderr, "VOLCONF: LNK_CONN is missing\n");
 588                         break;
 589                 }
 590                 conf = &conn->media->config[msg->any.lnk_volconf.index];
 591                 conf->copy_pend = msg->any.lnk_volconf.copy;
 592                 conf->ctl |= H2CONFCTL_UPDATE;
 593                 if (conf->thread == NULL) {
 594                         fprintf(stderr, "VOLCONF THREAD STARTED\n");
 595                         pthread_cond_init(&conf->cond, NULL);
 596                         pthread_create(&conf->thread, NULL,
 597                                        hammer2_volconf_thread, (void *)conf);
 598                 }
 599                 pthread_cond_signal(&conf->cond);
 600                 break;
 601         default:
 602                 /*
 603                  * Failsafe
 604                  */
 605                 if (msg->any.head.cmd & HAMMER2_MSGF_DELETE)
 606                         goto deleteconn;
 607                 hammer2_msg_reply(msg, HAMMER2_MSG_ERR_NOSUPP);
 608                 break;
 609         }
 610         pthread_mutex_unlock(&cluster_mtx);
 611 }
 612
 613 void
 614 hammer2_lnk_span(hammer2_msg_t *msg)
 615 {
 616         hammer2_state_t *state = msg->state;
 617         h2span_cluster_t dummy_cls;
 618         h2span_node_t dummy_node;
 619         h2span_cluster_t *cls;
 620         h2span_node_t *node;
 621         h2span_link_t *slink;
 622         h2span_relay_t *relay;
 623         char *alloc = NULL;
 624
 625         assert((msg->any.head.cmd & HAMMER2_MSGF_REPLY) == 0);
 626
 627         pthread_mutex_lock(&cluster_mtx);
 628
 629         /*
 630          * On transaction start we initialize the tracking infrastructure
 631          */
 632         if (msg->any.head.cmd & HAMMER2_MSGF_CREATE) {
 633                 assert(state->func == NULL);
 634                 state->func = hammer2_lnk_span;
 635
 636                 msg->any.lnk_span.label[sizeof(msg->any.lnk_span.label)-1] = 0;
 637
 638                 /*
 639                  * Find the cluster
 640                  */
 641                 dummy_cls.pfs_clid = msg->any.lnk_span.pfs_clid;
 642                 cls = RB_FIND(h2span_cluster_tree, &cluster_tree, &dummy_cls);
 643                 if (cls == NULL) {
 644                         cls = hammer2_alloc(sizeof(*cls));
 645                         cls->pfs_clid = msg->any.lnk_span.pfs_clid;
 646                         RB_INIT(&cls->tree);
 647                         RB_INSERT(h2span_cluster_tree, &cluster_tree, cls);
 648                 }
 649
 650                 /*
 651                  * Find the node
 652                  */
 653                 dummy_node.pfs_fsid = msg->any.lnk_span.pfs_fsid;
 654                 node = RB_FIND(h2span_node_tree, &cls->tree, &dummy_node);
 655                 if (node == NULL) {
 656                         node = hammer2_alloc(sizeof(*node));
 657                         node->pfs_fsid = msg->any.lnk_span.pfs_fsid;
 658                         node->cls = cls;
 659                         RB_INIT(&node->tree);
 660                         RB_INSERT(h2span_node_tree, &cls->tree, node);
 661                         snprintf(node->label, sizeof(node->label),
 662                                  "%s", msg->any.lnk_span.label);
 663                 }
 664
 665                 /*
 666                  * Create the link
 667                  */
 668                 assert(state->any.link == NULL);
 669                 slink = hammer2_alloc(sizeof(*slink));
 670                 TAILQ_INIT(&slink->relayq);
 671                 slink->node = node;
 672                 slink->dist = msg->any.lnk_span.dist;
 673                 slink->state = state;
 674                 state->any.link = slink;
 675
 676                 /*
 677                  * Embedded router structure in link for message forwarding.
 678                  *
 679                  * The spanning id for the router is the message id of
 680                  * the SPAN link it is embedded in, allowing messages to
 681                  * be routed via &slink->router.
 682                  */
 683                 slink->router = hammer2_router_alloc();
 684                 slink->router->iocom = state->iocom;
 685                 slink->router->link = slink;
 686                 slink->router->target = state->msgid;
 687                 hammer2_router_connect(slink->router);
 688
 689                 RB_INSERT(h2span_link_tree, &node->tree, slink);
 690
 691                 fprintf(stderr, "LNK_SPAN(thr %p): %p %s/%s dist=%d\n",
 692                         msg->router->iocom,
 693                         slink,
 694                         hammer2_uuid_to_str(&msg->any.lnk_span.pfs_clid,
 695                                             &alloc),
 696                         msg->any.lnk_span.label,
 697                         msg->any.lnk_span.dist);
 698                 free(alloc);
 699 #if 0
 700                 hammer2_relay_scan(NULL, node);
 701 #endif
 702                 hammer2_router_signal(msg->router);
 703         }
 704
 705         /*
 706          * On transaction terminate we remove the tracking infrastructure.
 707          */
 708         if (msg->any.head.cmd & HAMMER2_MSGF_DELETE) {
 709                 slink = state->any.link;
 710                 assert(slink != NULL);
 711                 node = slink->node;
 712                 cls = node->cls;
 713
 714                 fprintf(stderr, "LNK_DELE(thr %p): %p %s/%s dist=%d\n",
 715                         msg->router->iocom,
 716                         slink,
 717                         hammer2_uuid_to_str(&cls->pfs_clid, &alloc),
 718                         state->msg->any.lnk_span.label,
 719                         state->msg->any.lnk_span.dist);
 720                 free(alloc);
 721
 722                 /*
 723                  * Remove the router from consideration
 724                  */
 725                 hammer2_router_disconnect(&slink->router);
 726
 727                 /*
 728                  * Clean out all relays.  This requires terminating each
 729                  * relay transaction.
 730                  */
 731                 while ((relay = TAILQ_FIRST(&slink->relayq)) != NULL) {
 732                         hammer2_relay_delete(relay);
 733                 }
 734
 735                 /*
 736                  * Clean out the topology
 737                  */
 738                 RB_REMOVE(h2span_link_tree, &node->tree, slink);
 739                 if (RB_EMPTY(&node->tree)) {
 740                         RB_REMOVE(h2span_node_tree, &cls->tree, node);
 741                         if (RB_EMPTY(&cls->tree) && cls->refs == 0) {
 742                                 RB_REMOVE(h2span_cluster_tree,
 743                                           &cluster_tree, cls);
 744                                 hammer2_free(cls);
 745                         }
 746                         node->cls = NULL;
 747                         hammer2_free(node);
 748                         node = NULL;
 749                 }
 750                 state->any.link = NULL;
 751                 slink->state = NULL;
 752                 slink->node = NULL;
 753                 hammer2_free(slink);
 754
 755                 /*
 756                  * We have to terminate the transaction
 757                  */
 758                 hammer2_state_reply(state, 0);
 759                 /* state invalid after reply */
 760
 761                 /*
 762                  * If the node still exists issue any required updates.  If
 763                  * it doesn't then all related relays have already been
 764                  * removed and there's nothing left to do.
 765                  */
 766 #if 0
 767                 if (node)
 768                         hammer2_relay_scan(NULL, node);
 769 #endif
 770                 if (node)
 771                         hammer2_router_signal(msg->router);
 772         }
 773
 774         pthread_mutex_unlock(&cluster_mtx);
 775 }
 776
 777 /*
 778  * Messages received on relay SPANs.  These are open transactions so it is
 779  * in fact possible for the other end to close the transaction.
 780  *
 781  * XXX MPRACE on state structure
 782  */
 783 static void
 784 hammer2_lnk_relay(hammer2_msg_t *msg)
 785 {
 786         hammer2_state_t *state = msg->state;
 787         h2span_relay_t *relay;
 788
 789         assert(msg->any.head.cmd & HAMMER2_MSGF_REPLY);
 790
 791         if (msg->any.head.cmd & HAMMER2_MSGF_DELETE) {
 792                 pthread_mutex_lock(&cluster_mtx);
 793                 if ((relay = state->any.relay) != NULL) {
 794                         hammer2_relay_delete(relay);
 795                 } else {
 796                         hammer2_state_reply(state, 0);
 797                 }
 798                 pthread_mutex_unlock(&cluster_mtx);
 799         }
 800 }
 801
 802 /*
 803  * Update relay transactions for SPANs.
 804  *
 805  * Called with cluster_mtx held.
 806  */
 807 static void hammer2_relay_scan_specific(h2span_node_t *node,
 808                                         h2span_connect_t *conn);
 809
 810 static void
 811 hammer2_relay_scan(h2span_connect_t *conn, h2span_node_t *node)
 812 {
 813         h2span_cluster_t *cls;
 814
 815         if (node) {
 816                 /*
 817                  * Iterate specific node
 818                  */
 819                 TAILQ_FOREACH(conn, &connq, entry)
 820                         hammer2_relay_scan_specific(node, conn);
 821         } else {
 822                 /*
 823                  * Full iteration.
 824                  *
 825                  * Iterate cluster ids, nodes, and either a specific connection
 826                  * or all connections.
 827                  */
 828                 RB_FOREACH(cls, h2span_cluster_tree, &cluster_tree) {
 829                         /*
 830                          * Iterate node ids
 831                          */
 832                         RB_FOREACH(node, h2span_node_tree, &cls->tree) {
 833                                 /*
 834                                  * Synchronize the node's link (received SPANs)
 835                                  * with each connection's relays.
 836                                  */
 837                                 if (conn) {
 838                                         hammer2_relay_scan_specific(node, conn);
 839                                 } else {
 840                                         TAILQ_FOREACH(conn, &connq, entry) {
 841                                             hammer2_relay_scan_specific(node,
 842                                                                         conn);
 843                                         }
 844                                         assert(conn == NULL);
 845                                 }
 846                         }
 847                 }
 848         }
 849 }
 850
 851 /*
 852  * Update the relay'd SPANs for this (node, conn).
 853  *
 854  * Iterate links and adjust relays to match.  We only propagate the top link
 855  * for now (XXX we want to propagate the top two).
 856  *
 857  * The hammer2_relay_scan_cmp() function locates the first relay element
 858  * for any given node.  The relay elements will be sub-sorted by dist.
 859  */
 860 struct relay_scan_info {
 861         h2span_node_t *node;
 862         h2span_relay_t *relay;
 863 };
 864
 865 static int
 866 hammer2_relay_scan_cmp(h2span_relay_t *relay, void *arg)
 867 {
 868         struct relay_scan_info *info = arg;
 869
 870         if ((intptr_t)relay->link->node < (intptr_t)info->node)
 871                 return(-1);
 872         if ((intptr_t)relay->link->node > (intptr_t)info->node)
 873                 return(1);
 874         return(0);
 875 }
 876
 877 static int
 878 hammer2_relay_scan_callback(h2span_relay_t *relay, void *arg)
 879 {
 880         struct relay_scan_info *info = arg;
 881
 882         info->relay = relay;
 883         return(-1);
 884 }
 885
 886 static void
 887 hammer2_relay_scan_specific(h2span_node_t *node, h2span_connect_t *conn)
 888 {
 889         struct relay_scan_info info;
 890         h2span_relay_t *relay;
 891         h2span_relay_t *next_relay;
 892         h2span_link_t *slink;
 893         int count = 2;
 894
 895         info.node = node;
 896         info.relay = NULL;
 897
 898         /*
 899          * Locate the first related relay for the node on this connection.
 900          * relay will be NULL if there were none.
 901          */
 902         RB_SCAN(h2span_relay_tree, &conn->tree,
 903                 hammer2_relay_scan_cmp, hammer2_relay_scan_callback, &info);
 904         relay = info.relay;
 905         info.relay = NULL;
 906         if (relay)
 907                 assert(relay->link->node == node);
 908
 909         if (DebugOpt > 8)
 910                 fprintf(stderr, "relay scan for connection %p\n", conn);
 911
 912         /*
 913          * Iterate the node's links (received SPANs) in distance order,
 914          * lowest (best) dist first.
 915          */
 916         /* fprintf(stderr, "LOOP\n"); */
 917         RB_FOREACH(slink, h2span_link_tree, &node->tree) {
 918                 /*
 919                 fprintf(stderr, "SLINK %p RELAY %p(%p)\n",
 920                         slink, relay, relay ? relay->link : NULL);
 921                 */
 922                 /*
 923                  * PROPAGATE THE BEST LINKS OVER THE SPECIFIED CONNECTION.
 924                  *
 925                  * Track relays while iterating the best links and construct
 926                  * missing relays when necessary.
 927                  *
 928                  * (If some prior better link was removed it would have also
 929                  *  removed the relay, so the relay can only match exactly or
 930                  *  be worse).
 931                  */
 932                 if (relay && relay->link == slink) {
 933                         /*
 934                          * Match, relay already in-place, get the next
 935                          * relay to match against the next slink.
 936                          */
 937                         relay = RB_NEXT(h2span_relay_tree, &conn->tree, relay);
 938                         if (--count == 0)
 939                                 break;
 940                 } else if (slink->dist > HAMMER2_SPAN_MAXDIST) {
 941                         /*
 942                          * No match but span distance is too great,
 943                          * do not relay.  This prevents endless closed
 944                          * loops with ever-incrementing distances when
 945                          * the seed span is lost in the graph.
 946                          *
 947                          * All later spans will also be too far away so
 948                          * we can break out of the loop.
 949                          */
 950                         break;
 951                 } else if (slink->state->iocom == conn->state->iocom) {
 952                         /*
 953                          * No match but we would transmit a LNK_SPAN
 954                          * out the same connection it came in on, which
 955                          * can be trivially optimized out.
 956                          */
 957                         break;
 958                 } else {
 959                         /*
 960                          * No match, distance is ok, construct a new relay.
 961                          * (slink is better than relay).
 962                          */
 963                         hammer2_msg_t *msg;
 964
 965                         assert(relay == NULL ||
 966                                relay->link->node != slink->node ||
 967                                relay->link->dist >= slink->dist);
 968                         relay = hammer2_alloc(sizeof(*relay));
 969                         relay->conn = conn;
 970                         relay->link = slink;
 971
 972                         msg = hammer2_msg_alloc(conn->state->iocom->router, 0,
 973                                                 HAMMER2_LNK_SPAN |
 974                                                 HAMMER2_MSGF_CREATE,
 975                                                 hammer2_lnk_relay, relay);
 976                         relay->state = msg->state;
 977                         relay->router = hammer2_router_alloc();
 978                         relay->router->iocom = relay->state->iocom;
 979                         relay->router->relay = relay;
 980                         relay->router->target = relay->state->msgid;
 981
 982                         msg->any.lnk_span = slink->state->msg->any.lnk_span;
 983                         msg->any.lnk_span.dist = slink->dist + 1;
 984
 985                         hammer2_router_connect(relay->router);
 986
 987                         RB_INSERT(h2span_relay_tree, &conn->tree, relay);
 988                         TAILQ_INSERT_TAIL(&slink->relayq, relay, entry);
 989
 990                         hammer2_msg_write(msg);
 991
 992                         fprintf(stderr,
 993                                 "RELAY SPAN %p RELAY %p ON CLS=%p NODE=%p DIST=%d "
 994                                 "FD %d state %p\n",
 995                                 slink,
 996                                 relay,
 997                                 node->cls, node, slink->dist,
 998                                 conn->state->iocom->sock_fd, relay->state);
 999
1000                         /*
1001                          * Match (created new relay), get the next relay to
1002                          * match against the next slink.
1003                          */
1004                         relay = RB_NEXT(h2span_relay_tree, &conn->tree, relay);
1005                         if (--count == 0)
1006                                 break;
1007                 }
1008         }
1009
1010         /*
1011          * Any remaining relay's belonging to this connection which match
1012          * the node are in excess of the current aggregate spanning state
1013          * and should be removed.
1014          */
1015         while (relay && relay->link->node == node) {
1016                 next_relay = RB_NEXT(h2span_relay_tree, &conn->tree, relay);
1017                 hammer2_relay_delete(relay);
1018                 relay = next_relay;
1019         }
1020 }
1021
1022 static
1023 void
1024 hammer2_relay_delete(h2span_relay_t *relay)
1025 {
1026         fprintf(stderr,
1027                 "RELAY DELETE %p RELAY %p ON CLS=%p NODE=%p DIST=%d FD %d STATE %p\n",
1028                 relay->link,
1029                 relay,
1030                 relay->link->node->cls, relay->link->node,
1031                 relay->link->dist,
1032                 relay->conn->state->iocom->sock_fd, relay->state);
1033
1034         hammer2_router_disconnect(&relay->router);
1035
1036         RB_REMOVE(h2span_relay_tree, &relay->conn->tree, relay);
1037         TAILQ_REMOVE(&relay->link->relayq, relay, entry);
1038
1039         if (relay->state) {
1040                 relay->state->any.relay = NULL;
1041                 hammer2_state_reply(relay->state, 0);
1042                 /* state invalid after reply */
1043                 relay->state = NULL;
1044         }
1045         relay->conn = NULL;
1046         relay->link = NULL;
1047         hammer2_free(relay);
1048 }
1049
1050 static void *
1051 hammer2_volconf_thread(void *info)
1052 {
1053         h2span_media_config_t *conf = info;
1054
1055         pthread_mutex_lock(&cluster_mtx);
1056         while ((conf->ctl & H2CONFCTL_STOP) == 0) {
1057                 if (conf->ctl & H2CONFCTL_UPDATE) {
1058                         fprintf(stderr, "VOLCONF UPDATE\n");
1059                         conf->ctl &= ~H2CONFCTL_UPDATE;
1060                         if (bcmp(&conf->copy_run, &conf->copy_pend,
1061                                  sizeof(conf->copy_run)) == 0) {
1062                                 fprintf(stderr, "VOLCONF: no changes\n");
1063                                 continue;
1064                         }
1065                         /*
1066                          * XXX TODO - auto reconnect on lookup failure or
1067                          *              connect failure or stream failure.
1068                          */
1069
1070                         pthread_mutex_unlock(&cluster_mtx);
1071                         hammer2_volconf_stop(conf);
1072                         conf->copy_run = conf->copy_pend;
1073                         if (conf->copy_run.copyid != 0 &&
1074                             strncmp(conf->copy_run.path, "span:", 5) == 0) {
1075                                 hammer2_volconf_start(conf,
1076                                                       conf->copy_run.path + 5);
1077                         }
1078                         pthread_mutex_lock(&cluster_mtx);
1079                         fprintf(stderr, "VOLCONF UPDATE DONE state %d\n", conf->state);
1080                 }
1081                 if (conf->state == H2MC_CONNECT) {
1082                         hammer2_volconf_start(conf, conf->copy_run.path + 5);
1083                         pthread_mutex_unlock(&cluster_mtx);
1084                         sleep(5);
1085                         pthread_mutex_lock(&cluster_mtx);
1086                 } else {
1087                         pthread_cond_wait(&conf->cond, &cluster_mtx);
1088                 }
1089         }
1090         pthread_mutex_unlock(&cluster_mtx);
1091         hammer2_volconf_stop(conf);
1092         return(NULL);
1093 }
1094
1095 static
1096 void
1097 hammer2_volconf_stop(h2span_media_config_t *conf)
1098 {
1099         switch(conf->state) {
1100         case H2MC_STOPPED:
1101                 break;
1102         case H2MC_CONNECT:
1103                 conf->state = H2MC_STOPPED;
1104                 break;
1105         case H2MC_RUNNING:
1106                 shutdown(conf->fd, SHUT_WR);
1107                 pthread_join(conf->iocom_thread, NULL);
1108                 conf->iocom_thread = NULL;
1109                 break;
1110         }
1111 }
1112
1113 static
1114 void
1115 hammer2_volconf_start(h2span_media_config_t *conf, const char *hostname)
1116 {
1117         switch(conf->state) {
1118         case H2MC_STOPPED:
1119         case H2MC_CONNECT:
1120                 conf->fd = hammer2_connect(hostname);
1121                 if (conf->fd < 0) {
1122                         fprintf(stderr, "Unable to connect to %s\n", hostname);
1123                         conf->state = H2MC_CONNECT;
1124                 } else {
1125                         pthread_create(&conf->iocom_thread, NULL,
1126                                        master_service,
1127                                        (void *)(intptr_t)conf->fd);
1128                         conf->state = H2MC_RUNNING;
1129                 }
1130                 break;
1131         case H2MC_RUNNING:
1132                 break;
1133         }
1134 }
1135
1136 /************************************************************************
1137  *                      ROUTER AND MESSAGING HANDLES                    *
1138  ************************************************************************
1139  *
1140  * Basically the idea here is to provide a stable data structure which
1141  * can be localized to the caller for higher level protocols to work with.
1142  * Depends on the context, these hammer2_handle's can be pooled by use-case
1143  * and remain persistent through a client (or mount point's) life.
1144  */
1145
1146 #if 0
1147 /*
1148  * Obtain a stable handle on a cluster given its uuid.  This ties directly
1149  * into the global cluster topology, creating the structure if necessary
1150  * (even if the uuid does not exist or does not exist yet), and preventing
1151  * the structure from getting ripped out from under us while we hold a
1152  * pointer to it.
1153  */
1154 h2span_cluster_t *
1155 hammer2_cluster_get(uuid_t *pfs_clid)
1156 {
1157         h2span_cluster_t dummy_cls;
1158         h2span_cluster_t *cls;
1159
1160         dummy_cls.pfs_clid = *pfs_clid;
1161         pthread_mutex_lock(&cluster_mtx);
1162         cls = RB_FIND(h2span_cluster_tree, &cluster_tree, &dummy_cls);
1163         if (cls)
1164                 ++cls->refs;
1165         pthread_mutex_unlock(&cluster_mtx);
1166         return (cls);
1167 }
1168
1169 void
1170 hammer2_cluster_put(h2span_cluster_t *cls)
1171 {
1172         pthread_mutex_lock(&cluster_mtx);
1173         assert(cls->refs > 0);
1174         --cls->refs;
1175         if (RB_EMPTY(&cls->tree) && cls->refs == 0) {
1176                 RB_REMOVE(h2span_cluster_tree,
1177                           &cluster_tree, cls);
1178                 hammer2_free(cls);
1179         }
1180         pthread_mutex_unlock(&cluster_mtx);
1181 }
1182
1183 /*
1184  * Obtain a stable handle to a specific cluster node given its uuid.
1185  * This handle does NOT lock in the route to the node and is typically
1186  * used as part of the hammer2_handle_*() API to obtain a set of
1187  * stable nodes.
1188  */
1189 h2span_node_t *
1190 hammer2_node_get(h2span_cluster_t *cls, uuid_t *pfs_fsid)
1191 {
1192 }
1193
1194 #endif
1195
1196 #if 0
1197 /*
1198  * Acquire a persistent router structure given the cluster and node ids.
1199  * Messages can be transacted via this structure while held.  If the route
1200  * is lost messages will return failure.
1201  */
1202 hammer2_router_t *
1203 hammer2_router_get(uuid_t *pfs_clid, uuid_t *pfs_fsid)
1204 {
1205 }
1206
1207 /*
1208  * Release previously acquired router.
1209  */
1210 void
1211 hammer2_router_put(hammer2_router_t *router)
1212 {
1213 }
1214 #endif
1215
1216 /************************************************************************
1217  *                              DEBUGGER                                *
1218  ************************************************************************/
1219 /*
1220  * Dumps the spanning tree
1221  */
1222 void
1223 shell_tree(hammer2_router_t *router, char *cmdbuf __unused)
1224 {
1225         h2span_cluster_t *cls;
1226         h2span_node_t *node;
1227         h2span_link_t *slink;
1228         char *uustr = NULL;
1229
1230         pthread_mutex_lock(&cluster_mtx);
1231         RB_FOREACH(cls, h2span_cluster_tree, &cluster_tree) {
1232                 router_printf(router, "Cluster %s\n",
1233                              hammer2_uuid_to_str(&cls->pfs_clid, &uustr));
1234                 RB_FOREACH(node, h2span_node_tree, &cls->tree) {
1235                         router_printf(router, "    Node %s (%s)\n",
1236                                  hammer2_uuid_to_str(&node->pfs_fsid, &uustr),
1237                                  node->label);
1238                         RB_FOREACH(slink, h2span_link_tree, &node->tree) {
1239                                 router_printf(router, "\tLink dist=%d via %d\n",
1240                                              slink->dist,
1241                                              slink->state->iocom->sock_fd);
1242                         }
1243                 }
1244         }
1245         pthread_mutex_unlock(&cluster_mtx);
1246         if (uustr)
1247                 free(uustr);
1248 #if 0
1249         TAILQ_FOREACH(conn, &connq, entry) {
1250         }
1251 #endif
1252 }