ctdb/server/ctdb_takeover_helper.c

   1 /*
   2    CTDB IP takeover helper
   3
   4    Copyright (C) Martin Schwenke  2016
   5
   6    Based on ctdb_recovery_helper.c
   7    Copyright (C) Amitay Isaacs  2015
   8
   9    and ctdb_takeover.c
  10    Copyright (C) Ronnie Sahlberg  2007
  11    Copyright (C) Andrew Tridgell  2007
  12    Copyright (C) Martin Schwenke  2011
  13
  14    This program is free software; you can redistribute it and/or modify
  15    it under the terms of the GNU General Public License as published by
  16    the Free Software Foundation; either version 3 of the License, or
  17    (at your option) any later version.
  18
  19    This program is distributed in the hope that it will be useful,
  20    but WITHOUT ANY WARRANTY; without even the implied warranty of
  21    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22    GNU General Public License for more details.
  23
  24    You should have received a copy of the GNU General Public License
  25    along with this program; if not, see <http://www.gnu.org/licenses/>.
  26 */
  27
  28 #include "replace.h"
  29 #include "system/network.h"
  30 #include "system/filesys.h"
  31
  32 #include <popt.h>
  33 #include <talloc.h>
  34 #include <tevent.h>
  35
  36 #include "lib/util/debug.h"
  37 #include "lib/util/strv.h"
  38 #include "lib/util/strv_util.h"
  39 #include "lib/util/sys_rw.h"
  40 #include "lib/util/time.h"
  41 #include "lib/util/tevent_unix.h"
  42
  43 #include "protocol/protocol.h"
  44 #include "protocol/protocol_api.h"
  45 #include "client/client.h"
  46
  47 #include "common/logging.h"
  48
  49 #include "server/ipalloc.h"
  50
  51 static int takeover_timeout = 9;
  52
  53 #define TIMEOUT()       timeval_current_ofs(takeover_timeout, 0)
  54
  55 /*
  56  * Utility functions
  57  */
  58
  59 static bool generic_recv(struct tevent_req *req, int *perr)
  60 {
  61         int err;
  62
  63         if (tevent_req_is_unix_error(req, &err)) {
  64                 if (perr != NULL) {
  65                         *perr = err;
  66                 }
  67                 return false;
  68         }
  69
  70         return true;
  71 }
  72
  73 static enum ipalloc_algorithm
  74 determine_algorithm(const struct ctdb_tunable_list *tunables)
  75 {
  76         switch (tunables->ip_alloc_algorithm) {
  77         case 0:
  78                 return IPALLOC_DETERMINISTIC;
  79         case 1:
  80                 return IPALLOC_NONDETERMINISTIC;
  81         case 2:
  82                 return IPALLOC_LCP2;
  83         default:
  84                 return IPALLOC_LCP2;
  85         };
  86 }
  87
  88 /**********************************************************************/
  89
  90 struct get_public_ips_state {
  91         struct tevent_context *ev;
  92         struct ctdb_client_context *client;
  93         uint32_t *pnns;
  94         int count;
  95         struct ctdb_public_ip_list *ips;
  96 };
  97
  98 static void get_public_ips_done(struct tevent_req *subreq);
  99
 100 static struct tevent_req *get_public_ips_send(
 101                                 TALLOC_CTX *mem_ctx,
 102                                 struct tevent_context *ev,
 103                                 struct ctdb_client_context *client,
 104                                 uint32_t *pnns,
 105                                 int count,
 106                                 bool available_only)
 107 {
 108         struct tevent_req *req, *subreq;
 109         struct get_public_ips_state *state;
 110         struct ctdb_req_control request;
 111
 112         req = tevent_req_create(mem_ctx, &state, struct get_public_ips_state);
 113         if (req == NULL) {
 114                 return tevent_req_post(req, ev);
 115         }
 116
 117         state->pnns = pnns;
 118         state->count = count;
 119         state->ips = NULL;
 120
 121         ctdb_req_control_get_public_ips(&request, available_only);
 122         subreq = ctdb_client_control_multi_send(mem_ctx, ev, client,
 123                                                 state->pnns,
 124                                                 state->count,
 125                                                 TIMEOUT(), &request);
 126         if (tevent_req_nomem(subreq, req)) {
 127                 return tevent_req_post(req, ev);
 128         }
 129         tevent_req_set_callback(subreq, get_public_ips_done, req);
 130
 131         return req;
 132 }
 133
 134 static void get_public_ips_done(struct tevent_req *subreq)
 135 {
 136         struct tevent_req *req = tevent_req_callback_data(
 137                 subreq, struct tevent_req);
 138         struct get_public_ips_state *state = tevent_req_data(
 139                 req, struct get_public_ips_state);
 140         struct ctdb_reply_control **reply;
 141         int *err_list;
 142         int ret, i;
 143         bool status;
 144
 145         status = ctdb_client_control_multi_recv(subreq, &ret, state, &err_list,
 146                                                 &reply);
 147         TALLOC_FREE(subreq);
 148         if (! status) {
 149                 int ret2;
 150                 uint32_t pnn;
 151
 152                 ret2 = ctdb_client_control_multi_error(state->pnns,
 153                                                        state->count,
 154                                                        err_list, &pnn);
 155                 if (ret2 != 0) {
 156                         D_ERR("control GET_PUBLIC_IPS failed on "
 157                               "node %u, ret=%d\n", pnn, ret2);
 158                 } else {
 159                         D_ERR("control GET_PUBLIC_IPS failed, "
 160                               "ret=%d\n", ret);
 161                 }
 162                 tevent_req_error(req, ret);
 163                 return;
 164         }
 165
 166         state->ips = talloc_zero_array(state, struct ctdb_public_ip_list,
 167                                        state->count);
 168         if (tevent_req_nomem(state->ips, req)) {
 169                 return;
 170         }
 171
 172         for (i = 0; i < state->count; i++) {
 173                 uint32_t pnn;
 174                 struct ctdb_public_ip_list *ips;
 175
 176                 pnn = state->pnns[i];
 177                 ret = ctdb_reply_control_get_public_ips(reply[i], state->ips,
 178                                                         &ips);
 179                 if (ret != 0) {
 180                         D_ERR("control GET_PUBLIC_IPS failed on "
 181                               "node %u\n", pnn);
 182                         tevent_req_error(req, EIO);
 183                         return;
 184                 }
 185                 state->ips[pnn] = *ips;
 186         }
 187
 188         talloc_free(reply);
 189
 190         tevent_req_done(req);
 191 }
 192
 193 static bool get_public_ips_recv(struct tevent_req *req, int *perr,
 194                                 TALLOC_CTX *mem_ctx,
 195                                 struct ctdb_public_ip_list **ips)
 196 {
 197         struct get_public_ips_state *state = tevent_req_data(
 198                 req, struct get_public_ips_state);
 199         int err;
 200
 201         if (tevent_req_is_unix_error(req, &err)) {
 202                 if (perr != NULL) {
 203                         *perr = err;
 204                 }
 205                 return false;
 206         }
 207
 208         *ips = talloc_steal(mem_ctx, state->ips);
 209
 210         return true;
 211 }
 212
 213 /**********************************************************************/
 214
 215 struct release_ip_state {
 216         int num_sent;
 217         int num_replies;
 218         int num_fails;
 219         int err_any;
 220         uint32_t *ban_credits;
 221 };
 222
 223 struct release_ip_one_state {
 224         struct tevent_req *req;
 225         uint32_t *pnns;
 226         int count;
 227         const char *ip_str;
 228 };
 229
 230 static void release_ip_done(struct tevent_req *subreq);
 231
 232 static struct tevent_req *release_ip_send(TALLOC_CTX *mem_ctx,
 233                                           struct tevent_context *ev,
 234                                           struct ctdb_client_context *client,
 235                                           uint32_t *pnns,
 236                                           int count,
 237                                           struct timeval timeout,
 238                                           struct public_ip_list *all_ips,
 239                                           uint32_t *ban_credits)
 240 {
 241         struct tevent_req *req, *subreq;
 242         struct release_ip_state *state;
 243         struct ctdb_req_control request;
 244         struct public_ip_list *tmp_ip;
 245
 246         req = tevent_req_create(mem_ctx, &state, struct release_ip_state);
 247         if (req == NULL) {
 248                 return NULL;
 249         }
 250
 251         state->num_sent = 0;
 252         state->num_replies = 0;
 253         state->num_fails = 0;
 254         state->ban_credits = ban_credits;
 255
 256         /* Send a RELEASE_IP to all nodes that should not be hosting
 257          * each IP.  For each IP, all but one of these will be
 258          * redundant.  However, the redundant ones are used to tell
 259          * nodes which node should be hosting the IP so that commands
 260          * like "ctdb ip" can display a particular nodes idea of who
 261          * is hosting what. */
 262         for (tmp_ip = all_ips; tmp_ip != NULL; tmp_ip = tmp_ip->next) {
 263                 struct release_ip_one_state *substate;
 264                 struct ctdb_public_ip ip;
 265                 int i;
 266
 267                 substate = talloc_zero(state, struct release_ip_one_state);
 268                 if (tevent_req_nomem(substate, req)) {
 269                         return tevent_req_post(req, ev);
 270                 }
 271
 272                 substate->pnns = talloc_zero_array(substate, uint32_t, count);
 273                 if (tevent_req_nomem(substate->pnns, req)) {
 274                         return tevent_req_post(req, ev);
 275                 }
 276
 277                 substate->count = 0;
 278                 substate->req = req;
 279
 280                 substate->ip_str  = ctdb_sock_addr_to_string(substate,
 281                                                              &tmp_ip->addr);
 282                 if (tevent_req_nomem(substate->ip_str, req)) {
 283                         return tevent_req_post(req, ev);
 284                 }
 285
 286                 for (i = 0; i < count; i++) {
 287                         uint32_t pnn = pnns[i];
 288                         /* If pnn is not the node that should be
 289                          * hosting the IP then add it to the list of
 290                          * nodes that need to do a release. */
 291                         if (tmp_ip->pnn != pnn) {
 292                                 substate->pnns[substate->count] = pnn;
 293                                 substate->count++;
 294                         }
 295                 }
 296
 297                 ip.pnn = tmp_ip->pnn;
 298                 ip.addr = tmp_ip->addr;
 299                 ctdb_req_control_release_ip(&request, &ip);
 300                 subreq = ctdb_client_control_multi_send(state, ev, client,
 301                                                         substate->pnns,
 302                                                         substate->count,
 303                                                         timeout,/* cumulative */
 304                                                         &request);
 305                 if (tevent_req_nomem(subreq, req)) {
 306                         return tevent_req_post(req, ev);
 307                 }
 308                 tevent_req_set_callback(subreq, release_ip_done, substate);
 309
 310                 state->num_sent++;
 311         }
 312
 313         return req;
 314 }
 315
 316 static void release_ip_done(struct tevent_req *subreq)
 317 {
 318         struct release_ip_one_state *substate = tevent_req_callback_data(
 319                 subreq, struct release_ip_one_state);
 320         struct tevent_req *req = substate->req;
 321         struct release_ip_state *state = tevent_req_data(
 322                 req, struct release_ip_state);
 323         int ret, i;
 324         int *err_list;
 325         bool status, found_errors;
 326
 327         status = ctdb_client_control_multi_recv(subreq, &ret, state,
 328                                                 &err_list, NULL);
 329         TALLOC_FREE(subreq);
 330
 331         if (status) {
 332                 D_INFO("RELEASE_IP %s succeeded on %d nodes\n",
 333                        substate->ip_str, substate->count);
 334                 goto done;
 335         }
 336
 337         /* Get some clear error messages out of err_list and count
 338          * banning credits
 339          */
 340         found_errors = false;
 341         for (i = 0; i < substate->count; i++) {
 342                 int err = err_list[i];
 343                 if (err != 0) {
 344                         uint32_t pnn = substate->pnns[i];
 345
 346                         D_ERR("RELEASE_IP %s failed on node %u, "
 347                               "ret=%d\n", substate->ip_str, pnn, err);
 348
 349                         state->ban_credits[pnn]++;
 350                         state->err_any = err;
 351                         found_errors = true;
 352                 }
 353         }
 354         if (! found_errors) {
 355                 D_ERR("RELEASE_IP %s internal error, ret=%d\n",
 356                       substate->ip_str, ret);
 357                 state->err_any = EIO;
 358         }
 359
 360         state->num_fails++;
 361
 362 done:
 363         talloc_free(substate);
 364
 365         state->num_replies++;
 366
 367         if (state->num_replies < state->num_sent) {
 368                 /* Not all replies received, don't go further */
 369                 return;
 370         }
 371
 372         if (state->num_fails > 0) {
 373                 tevent_req_error(req, state->err_any);
 374                 return;
 375         }
 376
 377         tevent_req_done(req);
 378 }
 379
 380 static bool release_ip_recv(struct tevent_req *req, int *perr)
 381 {
 382         return generic_recv(req, perr);
 383 }
 384
 385 /**********************************************************************/
 386
 387 struct take_ip_state {
 388         int num_sent;
 389         int num_replies;
 390         int num_fails;
 391         int err_any;
 392         uint32_t *ban_credits;
 393 };
 394
 395 struct take_ip_one_state {
 396         struct tevent_req *req;
 397         uint32_t pnn;
 398         const char *ip_str;
 399 };
 400
 401 static void take_ip_done(struct tevent_req *subreq);
 402
 403 static struct tevent_req *take_ip_send(TALLOC_CTX *mem_ctx,
 404                                        struct tevent_context *ev,
 405                                        struct ctdb_client_context *client,
 406                                        struct timeval timeout,
 407                                        struct public_ip_list *all_ips,
 408                                        uint32_t *ban_credits)
 409 {
 410         struct tevent_req *req, *subreq;
 411         struct take_ip_state *state;
 412         struct ctdb_req_control request;
 413         struct public_ip_list *tmp_ip;
 414
 415         req = tevent_req_create(mem_ctx, &state, struct take_ip_state);
 416         if (req == NULL) {
 417                 return NULL;
 418         }
 419
 420         state->num_sent = 0;
 421         state->num_replies = 0;
 422         state->num_fails = 0;
 423         state->ban_credits = ban_credits;
 424
 425         /* For each IP, send a TAKOVER_IP to the node that should be
 426          * hosting it.  Many of these will often be redundant (since
 427          * the allocation won't have changed) but they can be useful
 428          * to recover from inconsistencies. */
 429         for (tmp_ip = all_ips; tmp_ip != NULL; tmp_ip = tmp_ip->next) {
 430                 struct take_ip_one_state *substate;
 431                 struct ctdb_public_ip ip;
 432
 433                 if (tmp_ip->pnn == -1) {
 434                         /* IP will be unassigned */
 435                         continue;
 436                 }
 437
 438                 substate = talloc_zero(state, struct take_ip_one_state);
 439                 if (tevent_req_nomem(substate, req)) {
 440                         return tevent_req_post(req, ev);
 441                 }
 442
 443                 substate->req = req;
 444                 substate->pnn = tmp_ip->pnn;
 445
 446                 substate->ip_str  = ctdb_sock_addr_to_string(substate,
 447                                                              &tmp_ip->addr);
 448                 if (tevent_req_nomem(substate->ip_str, req)) {
 449                         return tevent_req_post(req, ev);
 450                 }
 451
 452                 ip.pnn = tmp_ip->pnn;
 453                 ip.addr = tmp_ip->addr;
 454                 ctdb_req_control_takeover_ip(&request, &ip);
 455                 subreq = ctdb_client_control_send(
 456                                         state, ev, client, tmp_ip->pnn,
 457                                         timeout, /* cumulative */
 458                                         &request);
 459                 if (tevent_req_nomem(subreq, req)) {
 460                         return tevent_req_post(req, ev);
 461                 }
 462                 tevent_req_set_callback(subreq, take_ip_done, substate);
 463
 464                 state->num_sent++;
 465         }
 466
 467         /* None sent, finished... */
 468         if (state->num_sent == 0) {
 469                 tevent_req_done(req);
 470                 return tevent_req_post(req, ev);
 471         }
 472
 473         return req;
 474 }
 475
 476 static void take_ip_done(struct tevent_req *subreq)
 477 {
 478         struct take_ip_one_state *substate = tevent_req_callback_data(
 479                 subreq, struct take_ip_one_state);
 480         struct tevent_req *req = substate->req;
 481         struct ctdb_reply_control *reply;
 482         struct take_ip_state *state = tevent_req_data(
 483                 req, struct take_ip_state);
 484         int ret = 0;
 485         bool status;
 486
 487         status = ctdb_client_control_recv(subreq, &ret, state, &reply);
 488         TALLOC_FREE(subreq);
 489
 490         if (! status) {
 491                 D_ERR("TAKEOVER_IP %s failed to node %u, ret=%d\n",
 492                       substate->ip_str, substate->pnn, ret);
 493                 goto fail;
 494         }
 495
 496         ret = ctdb_reply_control_takeover_ip(reply);
 497         if (ret != 0) {
 498                 D_ERR("TAKEOVER_IP %s failed on node %u, ret=%d\n",
 499                       substate->ip_str, substate->pnn, ret);
 500                 goto fail;
 501         }
 502
 503         D_INFO("TAKEOVER_IP %s succeeded on node %u\n",
 504                substate->ip_str, substate->pnn);
 505         goto done;
 506
 507 fail:
 508         state->ban_credits[substate->pnn]++;
 509         state->num_fails++;
 510         state->err_any = ret;
 511
 512 done:
 513         talloc_free(substate);
 514
 515         state->num_replies++;
 516
 517         if (state->num_replies < state->num_sent) {
 518                 /* Not all replies received, don't go further */
 519                 return;
 520         }
 521
 522         if (state->num_fails > 0) {
 523                 tevent_req_error(req, state->err_any);
 524                 return;
 525         }
 526
 527         tevent_req_done(req);
 528 }
 529
 530 static bool take_ip_recv(struct tevent_req *req, int *perr)
 531 {
 532         return generic_recv(req, perr);
 533 }
 534
 535 /**********************************************************************/
 536
 537 struct ipreallocated_state {
 538         uint32_t *pnns;
 539         int count;
 540         uint32_t *ban_credits;
 541 };
 542
 543 static void ipreallocated_done(struct tevent_req *subreq);
 544
 545 static struct tevent_req *ipreallocated_send(TALLOC_CTX *mem_ctx,
 546                                              struct tevent_context *ev,
 547                                              struct ctdb_client_context *client,
 548                                              uint32_t *pnns,
 549                                              int count,
 550                                              struct timeval timeout,
 551                                              uint32_t *ban_credits)
 552 {
 553         struct tevent_req *req, *subreq;
 554         struct ipreallocated_state *state;
 555         struct ctdb_req_control request;
 556
 557         req = tevent_req_create(mem_ctx, &state, struct ipreallocated_state);
 558         if (req == NULL) {
 559                 return NULL;
 560         }
 561
 562         state->pnns = pnns;
 563         state->count = count;
 564         state->ban_credits = ban_credits;
 565
 566         ctdb_req_control_ipreallocated(&request);
 567         subreq = ctdb_client_control_multi_send(state, ev, client,
 568                                                 pnns, count,
 569                                                 timeout, /* cumulative */
 570                                                 &request);
 571         if (tevent_req_nomem(subreq, req)) {
 572                 return tevent_req_post(req, ev);
 573         }
 574         tevent_req_set_callback(subreq, ipreallocated_done, req);
 575
 576         return req;
 577 }
 578
 579 static void ipreallocated_done(struct tevent_req *subreq)
 580 {
 581         struct tevent_req *req = tevent_req_callback_data(
 582                 subreq, struct tevent_req);
 583         struct ipreallocated_state *state = tevent_req_data(
 584                 req, struct ipreallocated_state);
 585         int *err_list = NULL;
 586         int ret, i;
 587         bool status, found_errors;
 588
 589         status = ctdb_client_control_multi_recv(subreq, &ret, state,
 590                                                 &err_list, NULL);
 591         TALLOC_FREE(subreq);
 592
 593         if (status) {
 594                 D_INFO("IPREALLOCATED succeeded on %d nodes\n", state->count);
 595                 tevent_req_done(req);
 596                 return;
 597         }
 598
 599         /* Get some clear error messages out of err_list and count
 600          * banning credits
 601          */
 602         found_errors = false;
 603         for (i = 0; i < state->count; i++) {
 604                 int err = err_list[i];
 605                 if (err != 0) {
 606                         uint32_t pnn = state->pnns[i];
 607
 608                         D_ERR("IPREALLOCATED failed on node %u, ret=%d\n",
 609                               pnn, err);
 610
 611                         state->ban_credits[pnn]++;
 612                         found_errors = true;
 613                 }
 614         }
 615
 616         if (! found_errors) {
 617                 D_ERR("IPREALLOCATED internal error, ret=%d\n", ret);
 618         }
 619
 620         tevent_req_error(req, ret);
 621 }
 622
 623 static bool ipreallocated_recv(struct tevent_req *req, int *perr)
 624 {
 625         return generic_recv(req, perr);
 626 }
 627
 628 /**********************************************************************/
 629
 630 /*
 631  * Recalculate the allocation of public IPs to nodes and have the
 632  * nodes host their allocated addresses.
 633  *
 634  * - Get tunables
 635  * - Get nodemap
 636  * - Initialise IP allocation state.  Pass:
 637  *   + algorithm to be used;
 638  *   + various tunables (NoIPTakeover, NoIPFailback, NoIPHostOnAllDisabled)
 639  *   + list of nodes to force rebalance (internal structure, currently
 640  *     no way to fetch, only used by LCP2 for nodes that have had new
 641  *     IP addresses added).
 642  * - Set IP flags for IP allocation based on node map
 643  * - Retrieve known and available IP addresses (done separately so
 644  *   values can be faked in unit testing)
 645  * - Use ipalloc_set_public_ips() to set known and available IP
 646  *   addresses for allocation
 647  * - If cluster can't host IP addresses then jump to IPREALLOCATED
 648  * - Run IP allocation algorithm
 649  * - Send RELEASE_IP to all nodes for IPs they should not host
 650  * - Send TAKE_IP to all nodes for IPs they should host
 651  * - Send IPREALLOCATED to all nodes
 652  */
 653
 654 struct takeover_state {
 655         struct tevent_context *ev;
 656         struct ctdb_client_context *client;
 657         struct timeval timeout;
 658         int num_nodes;
 659         uint32_t *pnns_connected;
 660         int num_connected;
 661         uint32_t *pnns_active;
 662         int num_active;
 663         uint32_t destnode;
 664         uint32_t *force_rebalance_nodes;
 665         struct ctdb_tunable_list *tun_list;
 666         struct ipalloc_state *ipalloc_state;
 667         struct ctdb_public_ip_list *known_ips;
 668         struct public_ip_list *all_ips;
 669         uint32_t *ban_credits;
 670 };
 671
 672 static void takeover_tunables_done(struct tevent_req *subreq);
 673 static void takeover_nodemap_done(struct tevent_req *subreq);
 674 static void takeover_known_ips_done(struct tevent_req *subreq);
 675 static void takeover_avail_ips_done(struct tevent_req *subreq);
 676 static void takeover_release_ip_done(struct tevent_req *subreq);
 677 static void takeover_take_ip_done(struct tevent_req *subreq);
 678 static void takeover_ipreallocated(struct tevent_req *req);
 679 static void takeover_ipreallocated_done(struct tevent_req *subreq);
 680 static void takeover_failed(struct tevent_req *subreq, int ret);
 681 static void takeover_failed_done(struct tevent_req *subreq);
 682
 683 static struct tevent_req *takeover_send(TALLOC_CTX *mem_ctx,
 684                                         struct tevent_context *ev,
 685                                         struct ctdb_client_context *client,
 686                                         uint32_t *force_rebalance_nodes)
 687 {
 688         struct tevent_req *req, *subreq;
 689         struct takeover_state *state;
 690         struct ctdb_req_control request;
 691
 692         req = tevent_req_create(mem_ctx, &state, struct takeover_state);
 693         if (req == NULL) {
 694                 return NULL;
 695         }
 696
 697         state->ev = ev;
 698         state->client = client;
 699         state->force_rebalance_nodes = force_rebalance_nodes;
 700         state->destnode = ctdb_client_pnn(client);
 701
 702         ctdb_req_control_get_all_tunables(&request);
 703         subreq = ctdb_client_control_send(state, state->ev, state->client,
 704                                           state->destnode, TIMEOUT(),
 705                                           &request);
 706         if (tevent_req_nomem(subreq, req)) {
 707                 return tevent_req_post(req, ev);
 708         }
 709         tevent_req_set_callback(subreq, takeover_tunables_done, req);
 710
 711         return req;
 712 }
 713
 714 static void takeover_tunables_done(struct tevent_req *subreq)
 715 {
 716         struct tevent_req *req = tevent_req_callback_data(
 717                 subreq, struct tevent_req);
 718         struct takeover_state *state = tevent_req_data(
 719                 req, struct takeover_state);
 720         struct ctdb_reply_control *reply;
 721         struct ctdb_req_control request;
 722         int ret;
 723         bool status;
 724
 725         status = ctdb_client_control_recv(subreq, &ret, state, &reply);
 726         TALLOC_FREE(subreq);
 727         if (! status) {
 728                 D_ERR("control GET_ALL_TUNABLES failed, ret=%d\n", ret);
 729                 tevent_req_error(req, ret);
 730                 return;
 731         }
 732
 733         ret = ctdb_reply_control_get_all_tunables(reply, state,
 734                                                   &state->tun_list);
 735         if (ret != 0) {
 736                 D_ERR("control GET_ALL_TUNABLES failed, ret=%d\n", ret);
 737                 tevent_req_error(req, ret);
 738                 return;
 739         }
 740
 741         talloc_free(reply);
 742
 743         takeover_timeout = state->tun_list->takeover_timeout;
 744
 745         ctdb_req_control_get_nodemap(&request);
 746         subreq = ctdb_client_control_send(state, state->ev, state->client,
 747                                           state->destnode, TIMEOUT(),
 748                                           &request);
 749         if (tevent_req_nomem(subreq, req)) {
 750                 return;
 751         }
 752         tevent_req_set_callback(subreq, takeover_nodemap_done, req);
 753 }
 754
 755 static void takeover_nodemap_done(struct tevent_req *subreq)
 756 {
 757         struct tevent_req *req = tevent_req_callback_data(
 758                 subreq, struct tevent_req);
 759         struct takeover_state *state = tevent_req_data(
 760                 req, struct takeover_state);
 761         struct ctdb_reply_control *reply;
 762         bool status;
 763         int ret;
 764         struct ctdb_node_map *nodemap;
 765
 766         status = ctdb_client_control_recv(subreq, &ret, state, &reply);
 767         TALLOC_FREE(subreq);
 768         if (! status) {
 769                 D_ERR("control GET_NODEMAP failed to node %u, ret=%d\n",
 770                         state->destnode, ret);
 771                 tevent_req_error(req, ret);
 772                 return;
 773         }
 774
 775         ret = ctdb_reply_control_get_nodemap(reply, state, &nodemap);
 776         if (ret != 0) {
 777                 D_ERR("control GET_NODEMAP failed, ret=%d\n", ret);
 778                 tevent_req_error(req, ret);
 779                 return;
 780         }
 781
 782         state->num_nodes = nodemap->num;
 783
 784         state->num_connected = list_of_connected_nodes(nodemap,
 785                                                        CTDB_UNKNOWN_PNN, state,
 786                                                        &state->pnns_connected);
 787         if (state->num_connected <= 0) {
 788                 tevent_req_error(req, ENOMEM);
 789                 return;
 790         }
 791
 792         state->num_active = list_of_active_nodes(nodemap,
 793                                                  CTDB_UNKNOWN_PNN, state,
 794                                                  &state->pnns_active);
 795         if (state->num_active <= 0) {
 796                 tevent_req_error(req, ENOMEM);
 797                 return;
 798         }
 799
 800         /* Default timeout for early jump to IPREALLOCATED.  See below
 801          * for explanation of 3 times...
 802          */
 803         state->timeout = timeval_current_ofs(3 * takeover_timeout, 0);
 804
 805         state->ban_credits = talloc_zero_array(state, uint32_t,
 806                                                state->num_nodes);
 807         if (tevent_req_nomem(state->ban_credits, req)) {
 808                 return;
 809         }
 810
 811         if (state->tun_list->disable_ip_failover != 0) {
 812                 /* IP failover is completely disabled so just send out
 813                  * ipreallocated event.
 814                  */
 815                 takeover_ipreallocated(req);
 816                 return;
 817         }
 818
 819         state->ipalloc_state =
 820                 ipalloc_state_init(
 821                         state, state->num_nodes,
 822                         determine_algorithm(state->tun_list),
 823                         (state->tun_list->no_ip_takeover != 0),
 824                         (state->tun_list->no_ip_failback != 0),
 825                         (state->tun_list->no_ip_host_on_all_disabled != 0),
 826                         state->force_rebalance_nodes);
 827         if (tevent_req_nomem(state->ipalloc_state, req)) {
 828                 return;
 829         }
 830
 831         ipalloc_set_node_flags(state->ipalloc_state, nodemap);
 832
 833         subreq = get_public_ips_send(state, state->ev, state->client,
 834                                      state->pnns_active, state->num_active,
 835                                      false);
 836         if (tevent_req_nomem(subreq, req)) {
 837                 return;
 838         }
 839
 840         tevent_req_set_callback(subreq, takeover_known_ips_done, req);
 841 }
 842
 843 static void takeover_known_ips_done(struct tevent_req *subreq)
 844 {
 845         struct tevent_req *req = tevent_req_callback_data(
 846                 subreq, struct tevent_req);
 847         struct takeover_state *state = tevent_req_data(
 848                 req, struct takeover_state);
 849         int ret;
 850         bool status;
 851
 852         status = get_public_ips_recv(subreq, &ret, state, &state->known_ips);
 853         TALLOC_FREE(subreq);
 854
 855         if (! status) {
 856                 D_ERR("Failed to fetch known public IPs\n");
 857                 tevent_req_error(req, ret);
 858                 return;
 859         }
 860
 861         subreq = get_public_ips_send(state, state->ev, state->client,
 862                                      state->pnns_active, state->num_active,
 863                                      true);
 864         if (tevent_req_nomem(subreq, req)) {
 865                 return;
 866         }
 867
 868         tevent_req_set_callback(subreq, takeover_avail_ips_done, req);
 869 }
 870
 871 static void takeover_avail_ips_done(struct tevent_req *subreq)
 872 {
 873         struct tevent_req *req = tevent_req_callback_data(
 874                 subreq, struct tevent_req);
 875         struct takeover_state *state = tevent_req_data(
 876                 req, struct takeover_state);
 877         bool status;
 878         int ret;
 879         struct ctdb_public_ip_list *available_ips;
 880
 881         status = get_public_ips_recv(subreq, &ret, state, &available_ips);
 882         TALLOC_FREE(subreq);
 883
 884         if (! status) {
 885                 D_ERR("Failed to fetch available public IPs\n");
 886                 tevent_req_error(req, ret);
 887                 return;
 888         }
 889
 890         ipalloc_set_public_ips(state->ipalloc_state,
 891                                state->known_ips, available_ips);
 892
 893         if (! ipalloc_can_host_ips(state->ipalloc_state)) {
 894                 D_NOTICE("No nodes available to host public IPs yet\n");
 895                 takeover_ipreallocated(req);
 896                 return;
 897         }
 898
 899         /* Do the IP reassignment calculations */
 900         state->all_ips = ipalloc(state->ipalloc_state);
 901         if (tevent_req_nomem(state->all_ips, req)) {
 902                 return;
 903         }
 904
 905         /* Each of the following stages (RELEASE_IP, TAKEOVER_IP,
 906          * IPREALLOCATED) notionally has a timeout of TakeoverTimeout
 907          * seconds.  However, RELEASE_IP can take longer due to TCP
 908          * connection killing, so sometimes needs more time.
 909          * Therefore, use a cumulative timeout of TakeoverTimeout * 3
 910          * seconds across all 3 stages.  No explicit expiry checks are
 911          * needed before each stage because tevent is smart enough to
 912          * fire the timeouts even if they are in the past.  Initialise
 913          * this here so it explicitly covers the stages we're
 914          * interested in but, in particular, not the time taken by the
 915          * ipalloc().
 916          */
 917         state->timeout = timeval_current_ofs(3 * takeover_timeout, 0);
 918
 919         subreq = release_ip_send(state, state->ev, state->client,
 920                                  state->pnns_connected, state->num_connected,
 921                                  state->timeout, state->all_ips,
 922                                  state->ban_credits);
 923         if (tevent_req_nomem(subreq, req)) {
 924                 return;
 925         }
 926         tevent_req_set_callback(subreq, takeover_release_ip_done, req);
 927 }
 928
 929 static void takeover_release_ip_done(struct tevent_req *subreq)
 930 {
 931         struct tevent_req *req = tevent_req_callback_data(
 932                 subreq, struct tevent_req);
 933         struct takeover_state *state = tevent_req_data(
 934                 req, struct takeover_state);
 935         int ret;
 936         bool status;
 937
 938         status = release_ip_recv(subreq, &ret);
 939         TALLOC_FREE(subreq);
 940
 941         if (! status) {
 942                 takeover_failed(req, ret);
 943                 return;
 944         }
 945
 946         /* All released, now for takeovers */
 947
 948         subreq = take_ip_send(state, state->ev, state->client,
 949                               state->timeout, state->all_ips,
 950                               state->ban_credits);
 951         if (tevent_req_nomem(subreq, req)) {
 952                 return;
 953         }
 954         tevent_req_set_callback(subreq, takeover_take_ip_done, req);
 955 }
 956
 957 static void takeover_take_ip_done(struct tevent_req *subreq)
 958 {
 959         struct tevent_req *req = tevent_req_callback_data(
 960                 subreq, struct tevent_req);
 961         int ret = 0;
 962         bool status;
 963
 964         status = take_ip_recv(subreq, &ret);
 965         TALLOC_FREE(subreq);
 966
 967         if (! status) {
 968                 takeover_failed(req, ret);
 969                 return;
 970         }
 971
 972         takeover_ipreallocated(req);
 973 }
 974
 975 static void takeover_ipreallocated(struct tevent_req *req)
 976 {
 977         struct takeover_state *state = tevent_req_data(
 978                 req, struct takeover_state);
 979         struct tevent_req *subreq;
 980
 981         subreq = ipreallocated_send(state, state->ev, state->client,
 982                                     state->pnns_connected,
 983                                     state->num_connected,
 984                                     state->timeout,
 985                                     state->ban_credits);
 986         if (tevent_req_nomem(subreq, req)) {
 987                 return;
 988         }
 989         tevent_req_set_callback(subreq, takeover_ipreallocated_done, req);
 990 }
 991
 992 static void takeover_ipreallocated_done(struct tevent_req *subreq)
 993 {
 994         struct tevent_req *req = tevent_req_callback_data(
 995                 subreq, struct tevent_req);
 996         int ret;
 997         bool status;
 998
 999         status = ipreallocated_recv(subreq, &ret);
1000         TALLOC_FREE(subreq);
1001
1002         if (! status) {
1003                 takeover_failed(req, ret);
1004                 return;
1005         }
1006
1007         tevent_req_done(req);
1008 }
1009
1010 struct takeover_failed_state {
1011         struct tevent_req *req;
1012         int ret;
1013 };
1014
1015 void takeover_failed(struct tevent_req *req, int ret)
1016 {
1017         struct takeover_state *state = tevent_req_data(
1018                 req, struct takeover_state);
1019         struct tevent_req *subreq;
1020         uint32_t max_pnn = CTDB_UNKNOWN_PNN;
1021         int max_credits = 0;
1022         int pnn;
1023
1024         /* Check that bans are enabled */
1025         if (state->tun_list->enable_bans == 0) {
1026                 tevent_req_error(req, ret);
1027                 return;
1028         }
1029
1030         for (pnn = 0; pnn < state->num_nodes; pnn++) {
1031                 if (state->ban_credits[pnn] > max_credits) {
1032                         max_pnn = pnn;
1033                         max_credits = state->ban_credits[pnn];
1034                 }
1035         }
1036
1037         if (max_credits > 0) {
1038                 struct ctdb_req_message message;
1039                 struct takeover_failed_state *substate;
1040
1041                 D_WARNING("Assigning banning credits to node %u\n", max_pnn);
1042
1043                 substate = talloc_zero(state, struct takeover_failed_state);
1044                 if (tevent_req_nomem(substate, req)) {
1045                         return;
1046                 }
1047                 substate->req = req;
1048                 substate->ret = ret;
1049
1050                 message.srvid = CTDB_SRVID_BANNING;
1051                 message.data.pnn = max_pnn;
1052
1053                 subreq = ctdb_client_message_send(
1054                         state, state->ev, state->client,
1055                         ctdb_client_pnn(state->client),
1056                         &message);
1057                 if (subreq == NULL) {
1058                         D_ERR("failed to assign banning credits\n");
1059                         tevent_req_error(req, ret);
1060                         return;
1061                 }
1062                 tevent_req_set_callback(subreq, takeover_failed_done, substate);
1063         } else {
1064                 tevent_req_error(req, ret);
1065         }
1066 }
1067
1068 static void takeover_failed_done(struct tevent_req *subreq)
1069 {
1070         struct takeover_failed_state *substate = tevent_req_callback_data(
1071                 subreq, struct takeover_failed_state);
1072         struct tevent_req *req = substate->req;
1073         int ret;
1074         bool status;
1075
1076         status = ctdb_client_message_recv(subreq, &ret);
1077         TALLOC_FREE(subreq);
1078         if (! status) {
1079                 D_ERR("failed to assign banning credits, ret=%d\n", ret);
1080         }
1081
1082         ret = substate->ret;
1083         talloc_free(substate);
1084         tevent_req_error(req, ret);
1085 }
1086
1087 static void takeover_recv(struct tevent_req *req, int *perr)
1088 {
1089         generic_recv(req, perr);
1090 }
1091
1092 static uint32_t *parse_node_list(TALLOC_CTX *mem_ctx, const char* s)
1093 {
1094         char *strv = NULL;
1095         int num, i, ret;
1096         char *t;
1097         uint32_t *nodes;
1098
1099         ret = strv_split(mem_ctx, &strv, s, ",");
1100         if (ret != 0) {
1101                 D_ERR("out of memory\n");
1102                 return NULL;
1103         }
1104
1105         num = strv_count(strv);
1106
1107         nodes = talloc_array(mem_ctx, uint32_t, num);
1108         if (nodes == NULL) {
1109                 D_ERR("out of memory\n");
1110                 return NULL;
1111         }
1112
1113         t = NULL;
1114         for (i = 0; i < num; i++) {
1115                 t = strv_next(strv, t);
1116                 nodes[i] = atoi(t);
1117         }
1118
1119         return nodes;
1120 }
1121
1122 static void usage(const char *progname)
1123 {
1124         fprintf(stderr,
1125                 "\nUsage: %s <output-fd> <ctdb-socket-path> "
1126                 "[<force-rebalance-nodes>]\n",
1127                 progname);
1128 }
1129
1130 /*
1131  * Arguments - write fd, socket path
1132  */
1133 int main(int argc, const char *argv[])
1134 {
1135         int write_fd;
1136         const char *sockpath;
1137         TALLOC_CTX *mem_ctx;
1138         struct tevent_context *ev;
1139         struct ctdb_client_context *client;
1140         int ret;
1141         struct tevent_req *req;
1142         uint32_t *force_rebalance_nodes = NULL;
1143
1144         if (argc < 3 || argc > 4) {
1145                 usage(argv[0]);
1146                 exit(1);
1147         }
1148
1149         write_fd = atoi(argv[1]);
1150         sockpath = argv[2];
1151
1152         mem_ctx = talloc_new(NULL);
1153         if (mem_ctx == NULL) {
1154                 fprintf(stderr, "talloc_new() failed\n");
1155                 ret = ENOMEM;
1156                 goto done;
1157         }
1158
1159         if (argc == 4) {
1160                 force_rebalance_nodes = parse_node_list(mem_ctx, argv[3]);
1161                 if (force_rebalance_nodes == NULL) {
1162                         usage(argv[0]);
1163                         exit(1);
1164                 }
1165         }
1166
1167         logging_init(mem_ctx, NULL, NULL, "ctdb-takeover");
1168
1169         ev = tevent_context_init(mem_ctx);
1170         if (ev == NULL) {
1171                 D_ERR("tevent_context_init() failed\n");
1172                 ret = ENOMEM;
1173                 goto done;
1174         }
1175
1176         ret = ctdb_client_init(mem_ctx, ev, sockpath, &client);
1177         if (ret != 0) {
1178                 D_ERR("ctdb_client_init() failed, ret=%d\n", ret);
1179                 goto done;
1180         }
1181
1182         req = takeover_send(mem_ctx, ev, client, force_rebalance_nodes);
1183         if (req == NULL) {
1184                 D_ERR("takeover_send() failed\n");
1185                 ret = 1;
1186                 goto done;
1187         }
1188
1189         if (! tevent_req_poll(req, ev)) {
1190                 D_ERR("tevent_req_poll() failed\n");
1191                 ret = 1;
1192                 goto done;
1193         }
1194
1195         takeover_recv(req, &ret);
1196         TALLOC_FREE(req);
1197         if (ret != 0) {
1198                 D_ERR("takeover run failed, ret=%d\n", ret);
1199         }
1200
1201 done:
1202         sys_write_v(write_fd, &ret, sizeof(ret));
1203
1204         talloc_free(mem_ctx);
1205         return ret;
1206 }