hammer2 - Flesh out span code, API cleanups
[dragonfly.git] / sbin / hammer2 / msg_lnk.c
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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 weighted-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 * It is also important to note that several paths to the same PFS can be
99 * propagated along the same link, which allows concurrency and even
100 * redundancy over several network interfaces or via different routes through
101 * the topology. Any given transaction will use only a single route but busy
102 * servers will often have hundreds of transactions active simultaniously,
103 * so having multiple active paths through the network topology for A<->B
104 * will improve performance.
105 *
106 * --
107 *
108 * Most protocols consolidate operations rather than simply relaying them.
109 * This is particularly true of LEAF protocols (such as strict HAMMER2
110 * clients), of which there can be millions connecting into the cluster at
111 * various points. The SPAN protocol is not used for these LEAF elements.
112 *
113 * Instead the primary service they connect to implements a proxy for the
114 * client protocols so the core topology only has to propagate a couple of
115 * LNK_SPANs and not millions. LNK_SPANs are meant to be used only for
116 * core master nodes and satellite slaves and cache nodes.
117 */
118
119#include "hammer2.h"
120
121/*
122 * RED-BLACK TREE DEFINITIONS
123 *
124 * We need to track
125 *
126 * (1) shared fsid's (a cluster).
127 * (2) unique fsid's (a node in a cluster) <--- LNK_SPAN transactions.
128 *
129 * We need to aggegate all active LNK_SPANs, aggregate, and create our own
130 * outgoing LNK_SPAN transactions on each of our connections representing
131 * the aggregated state.
132 *
133 * h2span_connect - list of iocom connections who wish to receive SPAN
134 * propagation from other connections. Might contain
135 * a filter string. Only iocom's with an open
136 * LNK_CONN transactions are applicable for SPAN
137 * propagation.
138 *
139 * h2span_relay - List of links relayed (via SPAN). Essentially
140 * each relay structure represents a LNK_SPAN
141 * transaction that we initiated, verses h2span_link
142 * which is a LNK_SPAN transaction that we received.
143 *
144 * --
145 *
146 * h2span_cluster - Organizes the shared fsid's. One structure for
147 * each cluster.
148 *
149 * h2span_node - Organizes the nodes in a cluster. One structure
150 * for each unique {cluster,node}, aka {fsid, pfs_fsid}.
151 *
152 * h2span_link - Organizes all incoming and outgoing LNK_SPAN message
153 * transactions related to a node.
154 *
155 * One h2span_link structure for each incoming LNK_SPAN
156 * transaction. Links selected for propagation back
157 * out are also where the outgoing LNK_SPAN messages
158 * are indexed into (so we can propagate changes).
159 *
160 * The h2span_link's use a red-black tree to sort the
161 * weighted hop metric for the incoming LNK_SPAN. We
162 * then select the top N for outgoing. When the
163 * topology changes the top N may also change and cause
164 * new outgoing LNK_SPAN transactions to be opened
165 * and less desireable ones to be closed, causing
166 * transactional aborts within the message flow in
167 * the process.
168 *
169 * Also note - All outgoing LNK_SPAN message transactions are also
170 * entered into a red-black tree for use by the routing
171 * function. This is handled by msg.c in the state
172 * code, not here.
173 */
174
175struct h2span_link;
176struct h2span_relay;
177TAILQ_HEAD(h2span_connect_queue, h2span_connect);
178TAILQ_HEAD(h2span_relay_queue, h2span_relay);
179
180RB_HEAD(h2span_cluster_tree, h2span_cluster);
181RB_HEAD(h2span_node_tree, h2span_node);
182RB_HEAD(h2span_link_tree, h2span_link);
183RB_HEAD(h2span_relay_tree, h2span_relay);
184
185/*
186 * Received LNK_CONN transaction enables SPAN protocol over connection.
187 * (may contain filter).
188 */
189struct h2span_connect {
190 TAILQ_ENTRY(h2span_connect) entry;
191 struct h2span_relay_tree tree;
192 hammer2_state_t *state;
193};
194
195/*
196 * All received LNK_SPANs are organized by cluster (pfs_clid),
197 * node (pfs_fsid), and link (received LNK_SPAN transaction).
198 */
199struct h2span_cluster {
200 RB_ENTRY(h2span_cluster) rbnode;
201 struct h2span_node_tree tree;
202 uuid_t pfs_clid; /* shared fsid */
203};
204
205struct h2span_node {
206 RB_ENTRY(h2span_node) rbnode;
207 struct h2span_link_tree tree;
208 struct h2span_cluster *cls;
209 uuid_t pfs_fsid; /* unique fsid */
210};
211
212struct h2span_link {
213 RB_ENTRY(h2span_link) rbnode;
214 hammer2_state_t *state; /* state<->link */
215 struct h2span_node *node; /* related node */
216 int32_t weight;
217 struct h2span_relay_queue relayq; /* relay out */
218};
219
220/*
221 * Any LNK_SPAN transactions we receive which are relayed out other
222 * connections utilize this structure to track the LNK_SPAN transaction
223 * we initiate on the other connections, if selected for relay.
224 *
225 * In many respects this is the core of the protocol... actually figuring
226 * out what LNK_SPANs to relay. The spanid used for relaying is the
227 * address of the 'state' structure, which is why h2span_relay has to
228 * be entered into a RB-TREE based at h2span_connect (so we can look
229 * up the spanid to validate it).
230 */
231struct h2span_relay {
232 RB_ENTRY(h2span_relay) rbnode; /* from h2span_connect */
233 TAILQ_ENTRY(h2span_relay) entry; /* from link */
234 struct h2span_connect *conn;
235 hammer2_state_t *state; /* transmitted LNK_SPAN */
236 struct h2span_link *link; /* received LNK_SPAN */
237};
238
239
240typedef struct h2span_connect h2span_connect_t;
241typedef struct h2span_cluster h2span_cluster_t;
242typedef struct h2span_node h2span_node_t;
243typedef struct h2span_link h2span_link_t;
244typedef struct h2span_relay h2span_relay_t;
245
246static
247int
248h2span_cluster_cmp(h2span_cluster_t *cls1, h2span_cluster_t *cls2)
249{
250 return(uuid_compare(&cls1->pfs_clid, &cls2->pfs_clid, NULL));
251}
252
253static
254int
255h2span_node_cmp(h2span_node_t *node1, h2span_node_t *node2)
256{
257 return(uuid_compare(&node1->pfs_fsid, &node2->pfs_fsid, NULL));
258}
259
260static
261int
262h2span_link_cmp(h2span_link_t *link1, h2span_link_t *link2)
263{
264 if (link1->weight < link2->weight)
265 return(-1);
266 if (link1->weight > link2->weight)
267 return(1);
268 if ((intptr_t)link1 < (intptr_t)link2)
269 return(-1);
270 if ((intptr_t)link1 > (intptr_t)link2)
271 return(1);
272 return(0);
273}
274
275static
276int
277h2span_relay_cmp(h2span_relay_t *relay1, h2span_relay_t *relay2)
278{
279 if ((intptr_t)relay1->state < (intptr_t)relay2->state)
280 return(-1);
281 if ((intptr_t)relay1->state > (intptr_t)relay2->state)
282 return(1);
283 return(0);
284}
285
286RB_PROTOTYPE_STATIC(h2span_cluster_tree, h2span_cluster,
287 rbnode, h2span_cluster_cmp);
288RB_PROTOTYPE_STATIC(h2span_node_tree, h2span_node,
289 rbnode, h2span_node_cmp);
290RB_PROTOTYPE_STATIC(h2span_link_tree, h2span_link,
291 rbnode, h2span_link_cmp);
292RB_PROTOTYPE_STATIC(h2span_relay_tree, h2span_relay,
293 rbnode, h2span_relay_cmp);
294
295RB_GENERATE_STATIC(h2span_cluster_tree, h2span_cluster,
296 rbnode, h2span_cluster_cmp);
297RB_GENERATE_STATIC(h2span_node_tree, h2span_node,
298 rbnode, h2span_node_cmp);
299RB_GENERATE_STATIC(h2span_link_tree, h2span_link,
300 rbnode, h2span_link_cmp);
301RB_GENERATE_STATIC(h2span_relay_tree, h2span_relay,
302 rbnode, h2span_relay_cmp);
303
304/*
305 * Global mutex protects cluster_tree lookups.
306 */
307static pthread_mutex_t cluster_mtx;
308static struct h2span_cluster_tree cluster_tree = RB_INITIALIZER(cluster_tree);
309static struct h2span_connect_queue connq = TAILQ_HEAD_INITIALIZER(connq);
310
311static void hammer2_lnk_span(hammer2_state_t *state, hammer2_msg_t *msg);
312static void hammer2_lnk_conn(hammer2_state_t *state, hammer2_msg_t *msg);
313static void hammer2_lnk_conn_update(h2span_connect_t *conn);
314
315/*
316 * Receive a HAMMER2_MSG_PROTO_LNK message. This only called for
317 * one-way and opening-transactions since state->func will be assigned
318 * in all other cases.
319 */
320void
321hammer2_msg_lnk(hammer2_iocom_t *iocom, hammer2_msg_t *msg)
322{
323 switch(msg->any.head.cmd & HAMMER2_MSGF_BASECMDMASK) {
324 case HAMMER2_LNK_CONN:
325 hammer2_lnk_conn(msg->state, msg);
326 break;
327 case HAMMER2_LNK_SPAN:
328 hammer2_lnk_span(msg->state, msg);
329 break;
330 default:
331 fprintf(stderr,
332 "MSG_PROTO_LNK: Unknown msg %08x\n", msg->any.head.cmd);
333 hammer2_msg_reply(iocom, msg, HAMMER2_MSG_ERR_UNKNOWN);
334 /* state invalid after reply */
335 break;
336 }
337}
338
339void
340hammer2_lnk_conn(hammer2_state_t *state, hammer2_msg_t *msg)
341{
342 h2span_connect_t *conn;
343 h2span_relay_t *relay;
344 char *alloc = NULL;
345
346 pthread_mutex_lock(&cluster_mtx);
347
348 /*
349 * On transaction start we allocate a new h2span_connect and
350 * acknowledge the request, leaving the transaction open.
351 */
352 if (msg->any.head.cmd & HAMMER2_MSGF_CREATE) {
353 state->func = hammer2_lnk_conn;
354
355 fprintf(stderr, "LNK_CONN(%016jx): %s/%s\n",
356 (intmax_t)msg->any.head.msgid,
357 hammer2_uuid_to_str(&msg->any.lnk_conn.pfs_clid,
358 &alloc),
359 msg->any.lnk_conn.label);
360 free(alloc);
361
362 conn = hammer2_alloc(sizeof(*conn));
363
364 RB_INIT(&conn->tree);
365 conn->state = state;
366 state->any.conn = conn;
367 TAILQ_INSERT_TAIL(&connq, conn, entry);
368
369 hammer2_lnk_conn_update(conn);
370 hammer2_msg_result(state->iocom, msg, 0);
371 }
372
373 /*
374 * On transaction terminate we clean out our h2span_connect
375 * and acknowledge the request, closing the transaction.
376 */
377 if (msg->any.head.cmd & HAMMER2_MSGF_DELETE) {
378 fprintf(stderr, "LNK_CONN: Terminated\n");
379 conn = state->any.conn;
380 assert(conn);
381 while ((relay = RB_ROOT(&conn->tree)) != NULL) {
382 RB_REMOVE(h2span_relay_tree, &conn->tree, relay);
383 TAILQ_REMOVE(&relay->link->relayq, relay, entry);
384
385 if (relay->state) {
386 relay->state->any.relay = NULL;
387 hammer2_state_reply(relay->state, 0);
388 /* state invalid after reply */
389 relay->state = NULL;
390 }
391 relay->conn = NULL;
392 relay->link = NULL;
393 hammer2_free(relay);
394 }
395
396 /*
397 * Clean out conn
398 */
399 conn->state = NULL;
400 msg->state->any.conn = NULL;
401 TAILQ_REMOVE(&connq, conn, entry);
402 hammer2_free(conn);
403
404 hammer2_msg_reply(state->iocom, msg, 0);
405 /* state invalid after reply */
406 }
407 pthread_mutex_unlock(&cluster_mtx);
408}
409
410void
411hammer2_lnk_span(hammer2_state_t *state, hammer2_msg_t *msg)
412{
413 h2span_cluster_t dummy_cls;
414 h2span_node_t dummy_node;
415 h2span_cluster_t *cls;
416 h2span_node_t *node;
417 h2span_link_t *slink;
418 h2span_relay_t *relay;
419 char *alloc = NULL;
420
421 pthread_mutex_lock(&cluster_mtx);
422
423 /*
424 * On transaction start we initialize the tracking infrastructure
425 */
426 if (msg->any.head.cmd & HAMMER2_MSGF_CREATE) {
427 state->func = hammer2_lnk_span;
428
429 fprintf(stderr, "LNK_SPAN: %s/%s\n",
430 hammer2_uuid_to_str(&msg->any.lnk_span.pfs_clid,
431 &alloc),
432 msg->any.lnk_span.label);
433 free(alloc);
434
435 /*
436 * Find the cluster
437 */
438 dummy_cls.pfs_clid = msg->any.lnk_span.pfs_clid;
439 cls = RB_FIND(h2span_cluster_tree, &cluster_tree, &dummy_cls);
440 if (cls == NULL) {
441 cls = hammer2_alloc(sizeof(*cls));
442 cls->pfs_clid = msg->any.lnk_span.pfs_clid;
443 RB_INIT(&cls->tree);
444 RB_INSERT(h2span_cluster_tree, &cluster_tree, cls);
445 }
446
447 /*
448 * Find the node
449 */
450 dummy_node.pfs_fsid = msg->any.lnk_span.pfs_fsid;
451 node = RB_FIND(h2span_node_tree, &cls->tree, &dummy_node);
452 if (node == NULL) {
453 node = hammer2_alloc(sizeof(*node));
454 node->pfs_fsid = msg->any.lnk_span.pfs_fsid;
455 node->cls = cls;
456 RB_INIT(&node->tree);
457 RB_INSERT(h2span_node_tree, &cls->tree, node);
458 }
459
460 /*
461 * Create the link
462 */
463 assert(state->any.link == NULL);
464 slink = hammer2_alloc(sizeof(*slink));
465 slink->node = node;
466 slink->weight = msg->any.lnk_span.weight;
467 slink->state = state;
468 state->any.link = slink;
469 RB_INSERT(h2span_link_tree, &node->tree, slink);
470
471 /*
472 * Now filter and relay the span to all other iocoms. XXX
473 */
474 }
475
476 /*
477 * On transaction terminate we remove the tracking infrastructure.
478 */
479 if (msg->any.head.cmd & HAMMER2_MSGF_DELETE) {
480 slink = state->any.link;
481 assert(slink != NULL);
482 node = slink->node;
483 cls = node->cls;
484
485 /*
486 * Clean out all relays
487 */
488 while ((relay = TAILQ_FIRST(&slink->relayq)) != NULL) {
489 RB_REMOVE(h2span_relay_tree, &relay->conn->tree, relay);
490 TAILQ_REMOVE(&slink->relayq, relay, entry);
491
492 if (relay->state) {
493 relay->state->any.relay = NULL;
494 hammer2_state_reply(relay->state, 0);
495 /* state invalid after reply */
496 relay->state = NULL;
497 }
498 relay->conn = NULL;
499 relay->link = NULL;
500 hammer2_free(relay);
501 }
502
503 /*
504 * Clean out the topology
505 */
506 RB_REMOVE(h2span_link_tree, &node->tree, slink);
507 if (RB_EMPTY(&node->tree)) {
508 RB_REMOVE(h2span_node_tree, &cls->tree, node);
509 if (RB_EMPTY(&cls->tree)) {
510 RB_REMOVE(h2span_cluster_tree,
511 &cluster_tree, cls);
512 hammer2_free(cls);
513 }
514 node->cls = NULL;
515 hammer2_free(node);
516 }
517 state->any.link = NULL;
518 slink->state = NULL;
519 slink->node = NULL;
520 hammer2_free(slink);
521 }
522
523 pthread_mutex_unlock(&cluster_mtx);
524}
525
526/*
527 * Initiate/Update the relayed spans associated with a connection.
528 */
529static void
530hammer2_lnk_conn_update(h2span_connect_t *conn __unused)
531{
532}