sbin/hastd/hastd.c

   1 /*-
   2  * Copyright (c) 2009-2010 The FreeBSD Foundation
   3  * Copyright (c) 2010-2011 Pawel Jakub Dawidek <pawel@dawidek.net>
   4  * All rights reserved.
   5  *
   6  * This software was developed by Pawel Jakub Dawidek under sponsorship from
   7  * the FreeBSD Foundation.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD$");
  33
  34 #include <sys/param.h>
  35 #include <sys/linker.h>
  36 #include <sys/module.h>
  37 #include <sys/stat.h>
  38 #include <sys/wait.h>
  39
  40 #include <err.h>
  41 #include <errno.h>
  42 #include <libutil.h>
  43 #include <signal.h>
  44 #include <stdbool.h>
  45 #include <stdio.h>
  46 #include <stdlib.h>
  47 #include <string.h>
  48 #include <sysexits.h>
  49 #include <time.h>
  50 #include <unistd.h>
  51
  52 #include <activemap.h>
  53 #include <pjdlog.h>
  54
  55 #include "control.h"
  56 #include "event.h"
  57 #include "hast.h"
  58 #include "hast_proto.h"
  59 #include "hastd.h"
  60 #include "hooks.h"
  61 #include "subr.h"
  62
  63 /* Path to configuration file. */
  64 const char *cfgpath = HAST_CONFIG;
  65 /* Hastd configuration. */
  66 static struct hastd_config *cfg;
  67 /* Was SIGINT or SIGTERM signal received? */
  68 bool sigexit_received = false;
  69 /* PID file handle. */
  70 struct pidfh *pfh;
  71
  72 /* How often check for hooks running for too long. */
  73 #define REPORT_INTERVAL 5
  74
  75 static void
  76 usage(void)
  77 {
  78
  79         errx(EX_USAGE, "[-dFh] [-c config] [-P pidfile]");
  80 }
  81
  82 static void
  83 g_gate_load(void)
  84 {
  85
  86         if (modfind("g_gate") == -1) {
  87                 /* Not present in kernel, try loading it. */
  88                 if (kldload("geom_gate") == -1 || modfind("g_gate") == -1) {
  89                         if (errno != EEXIST) {
  90                                 pjdlog_exit(EX_OSERR,
  91                                     "Unable to load geom_gate module");
  92                         }
  93                 }
  94         }
  95 }
  96
  97 void
  98 descriptors_cleanup(struct hast_resource *res)
  99 {
 100         struct hast_resource *tres;
 101
 102         TAILQ_FOREACH(tres, &cfg->hc_resources, hr_next) {
 103                 if (tres == res) {
 104                         PJDLOG_VERIFY(res->hr_role == HAST_ROLE_SECONDARY ||
 105                             (res->hr_remotein == NULL &&
 106                              res->hr_remoteout == NULL));
 107                         continue;
 108                 }
 109                 if (tres->hr_remotein != NULL)
 110                         proto_close(tres->hr_remotein);
 111                 if (tres->hr_remoteout != NULL)
 112                         proto_close(tres->hr_remoteout);
 113                 if (tres->hr_ctrl != NULL)
 114                         proto_close(tres->hr_ctrl);
 115                 if (tres->hr_event != NULL)
 116                         proto_close(tres->hr_event);
 117                 if (tres->hr_conn != NULL)
 118                         proto_close(tres->hr_conn);
 119         }
 120         if (cfg->hc_controlin != NULL)
 121                 proto_close(cfg->hc_controlin);
 122         proto_close(cfg->hc_controlconn);
 123         proto_close(cfg->hc_listenconn);
 124         (void)pidfile_close(pfh);
 125         hook_fini();
 126         pjdlog_fini();
 127 }
 128
 129 static const char *
 130 dtype2str(mode_t mode)
 131 {
 132
 133         if (S_ISBLK(mode))
 134                 return ("block device");
 135         else if (S_ISCHR(mode))
 136                 return ("character device");
 137         else if (S_ISDIR(mode))
 138                 return ("directory");
 139         else if (S_ISFIFO(mode))
 140                 return ("pipe or FIFO");
 141         else if (S_ISLNK(mode))
 142                 return ("symbolic link");
 143         else if (S_ISREG(mode))
 144                 return ("regular file");
 145         else if (S_ISSOCK(mode))
 146                 return ("socket");
 147         else if (S_ISWHT(mode))
 148                 return ("whiteout");
 149         else
 150                 return ("unknown");
 151 }
 152
 153 void
 154 descriptors_assert(const struct hast_resource *res, int pjdlogmode)
 155 {
 156         char msg[256];
 157         struct stat sb;
 158         long maxfd;
 159         bool isopen;
 160         mode_t mode;
 161         int fd;
 162
 163         /*
 164          * At this point descriptor to syslog socket is closed, so if we want
 165          * to log assertion message, we have to first store it in 'msg' local
 166          * buffer and then open syslog socket and log it.
 167          */
 168         msg[0] = '\0';
 169
 170         maxfd = sysconf(_SC_OPEN_MAX);
 171         if (maxfd < 0) {
 172                 pjdlog_init(pjdlogmode);
 173                 pjdlog_prefix_set("[%s] (%s) ", res->hr_name,
 174                     role2str(res->hr_role));
 175                 pjdlog_errno(LOG_WARNING, "sysconf(_SC_OPEN_MAX) failed");
 176                 pjdlog_fini();
 177                 maxfd = 16384;
 178         }
 179         for (fd = 0; fd <= maxfd; fd++) {
 180                 if (fstat(fd, &sb) == 0) {
 181                         isopen = true;
 182                         mode = sb.st_mode;
 183                 } else if (errno == EBADF) {
 184                         isopen = false;
 185                         mode = 0;
 186                 } else {
 187                         (void)snprintf(msg, sizeof(msg),
 188                             "Unable to fstat descriptor %d: %s", fd,
 189                             strerror(errno));
 190                         break;
 191                 }
 192                 if (fd == STDIN_FILENO || fd == STDOUT_FILENO ||
 193                     fd == STDERR_FILENO) {
 194                         if (!isopen) {
 195                                 (void)snprintf(msg, sizeof(msg),
 196                                     "Descriptor %d (%s) is closed, but should be open.",
 197                                     fd, (fd == STDIN_FILENO ? "stdin" :
 198                                     (fd == STDOUT_FILENO ? "stdout" : "stderr")));
 199                                 break;
 200                         }
 201                 } else if (fd == proto_descriptor(res->hr_event)) {
 202                         if (!isopen) {
 203                                 (void)snprintf(msg, sizeof(msg),
 204                                     "Descriptor %d (event) is closed, but should be open.",
 205                                     fd);
 206                                 break;
 207                         }
 208                         if (!S_ISSOCK(mode)) {
 209                                 (void)snprintf(msg, sizeof(msg),
 210                                     "Descriptor %d (event) is %s, but should be %s.",
 211                                     fd, dtype2str(mode), dtype2str(S_IFSOCK));
 212                                 break;
 213                         }
 214                 } else if (fd == proto_descriptor(res->hr_ctrl)) {
 215                         if (!isopen) {
 216                                 (void)snprintf(msg, sizeof(msg),
 217                                     "Descriptor %d (ctrl) is closed, but should be open.",
 218                                     fd);
 219                                 break;
 220                         }
 221                         if (!S_ISSOCK(mode)) {
 222                                 (void)snprintf(msg, sizeof(msg),
 223                                     "Descriptor %d (ctrl) is %s, but should be %s.",
 224                                     fd, dtype2str(mode), dtype2str(S_IFSOCK));
 225                                 break;
 226                         }
 227                 } else if (res->hr_role == HAST_ROLE_PRIMARY &&
 228                     fd == proto_descriptor(res->hr_conn)) {
 229                         if (!isopen) {
 230                                 (void)snprintf(msg, sizeof(msg),
 231                                     "Descriptor %d (conn) is closed, but should be open.",
 232                                     fd);
 233                                 break;
 234                         }
 235                         if (!S_ISSOCK(mode)) {
 236                                 (void)snprintf(msg, sizeof(msg),
 237                                     "Descriptor %d (conn) is %s, but should be %s.",
 238                                     fd, dtype2str(mode), dtype2str(S_IFSOCK));
 239                                 break;
 240                         }
 241                 } else if (res->hr_role == HAST_ROLE_SECONDARY &&
 242                     res->hr_conn != NULL &&
 243                     fd == proto_descriptor(res->hr_conn)) {
 244                         if (isopen) {
 245                                 (void)snprintf(msg, sizeof(msg),
 246                                     "Descriptor %d (conn) is open, but should be closed.",
 247                                     fd);
 248                                 break;
 249                         }
 250                 } else if (res->hr_role == HAST_ROLE_SECONDARY &&
 251                     fd == proto_descriptor(res->hr_remotein)) {
 252                         if (!isopen) {
 253                                 (void)snprintf(msg, sizeof(msg),
 254                                     "Descriptor %d (remote in) is closed, but should be open.",
 255                                     fd);
 256                                 break;
 257                         }
 258                         if (!S_ISSOCK(mode)) {
 259                                 (void)snprintf(msg, sizeof(msg),
 260                                     "Descriptor %d (remote in) is %s, but should be %s.",
 261                                     fd, dtype2str(mode), dtype2str(S_IFSOCK));
 262                                 break;
 263                         }
 264                 } else if (res->hr_role == HAST_ROLE_SECONDARY &&
 265                     fd == proto_descriptor(res->hr_remoteout)) {
 266                         if (!isopen) {
 267                                 (void)snprintf(msg, sizeof(msg),
 268                                     "Descriptor %d (remote out) is closed, but should be open.",
 269                                     fd);
 270                                 break;
 271                         }
 272                         if (!S_ISSOCK(mode)) {
 273                                 (void)snprintf(msg, sizeof(msg),
 274                                     "Descriptor %d (remote out) is %s, but should be %s.",
 275                                     fd, dtype2str(mode), dtype2str(S_IFSOCK));
 276                                 break;
 277                         }
 278                 } else {
 279                         if (isopen) {
 280                                 (void)snprintf(msg, sizeof(msg),
 281                                     "Descriptor %d is open (%s), but should be closed.",
 282                                     fd, dtype2str(mode));
 283                                 break;
 284                         }
 285                 }
 286         }
 287         if (msg[0] != '\0') {
 288                 pjdlog_init(pjdlogmode);
 289                 pjdlog_prefix_set("[%s] (%s) ", res->hr_name,
 290                     role2str(res->hr_role));
 291                 PJDLOG_ABORT("%s", msg);
 292         }
 293 }
 294
 295 static void
 296 child_exit_log(unsigned int pid, int status)
 297 {
 298
 299         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
 300                 pjdlog_debug(1, "Worker process exited gracefully (pid=%u).",
 301                     pid);
 302         } else if (WIFSIGNALED(status)) {
 303                 pjdlog_error("Worker process killed (pid=%u, signal=%d).",
 304                     pid, WTERMSIG(status));
 305         } else {
 306                 pjdlog_error("Worker process exited ungracefully (pid=%u, exitcode=%d).",
 307                     pid, WIFEXITED(status) ? WEXITSTATUS(status) : -1);
 308         }
 309 }
 310
 311 static void
 312 child_exit(void)
 313 {
 314         struct hast_resource *res;
 315         int status;
 316         pid_t pid;
 317
 318         while ((pid = wait3(&status, WNOHANG, NULL)) > 0) {
 319                 /* Find resource related to the process that just exited. */
 320                 TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
 321                         if (pid == res->hr_workerpid)
 322                                 break;
 323                 }
 324                 if (res == NULL) {
 325                         /*
 326                          * This can happen when new connection arrives and we
 327                          * cancel child responsible for the old one or if this
 328                          * was hook which we executed.
 329                          */
 330                         hook_check_one(pid, status);
 331                         continue;
 332                 }
 333                 pjdlog_prefix_set("[%s] (%s) ", res->hr_name,
 334                     role2str(res->hr_role));
 335                 child_exit_log(pid, status);
 336                 child_cleanup(res);
 337                 if (res->hr_role == HAST_ROLE_PRIMARY) {
 338                         /*
 339                          * Restart child process if it was killed by signal
 340                          * or exited because of temporary problem.
 341                          */
 342                         if (WIFSIGNALED(status) ||
 343                             (WIFEXITED(status) &&
 344                              WEXITSTATUS(status) == EX_TEMPFAIL)) {
 345                                 sleep(1);
 346                                 pjdlog_info("Restarting worker process.");
 347                                 hastd_primary(res);
 348                         } else {
 349                                 res->hr_role = HAST_ROLE_INIT;
 350                                 pjdlog_info("Changing resource role back to %s.",
 351                                     role2str(res->hr_role));
 352                         }
 353                 }
 354                 pjdlog_prefix_set("%s", "");
 355         }
 356 }
 357
 358 static bool
 359 resource_needs_restart(const struct hast_resource *res0,
 360     const struct hast_resource *res1)
 361 {
 362
 363         PJDLOG_ASSERT(strcmp(res0->hr_name, res1->hr_name) == 0);
 364
 365         if (strcmp(res0->hr_provname, res1->hr_provname) != 0)
 366                 return (true);
 367         if (strcmp(res0->hr_localpath, res1->hr_localpath) != 0)
 368                 return (true);
 369         if (res0->hr_role == HAST_ROLE_INIT ||
 370             res0->hr_role == HAST_ROLE_SECONDARY) {
 371                 if (strcmp(res0->hr_remoteaddr, res1->hr_remoteaddr) != 0)
 372                         return (true);
 373                 if (strcmp(res0->hr_sourceaddr, res1->hr_sourceaddr) != 0)
 374                         return (true);
 375                 if (res0->hr_replication != res1->hr_replication)
 376                         return (true);
 377                 if (res0->hr_checksum != res1->hr_checksum)
 378                         return (true);
 379                 if (res0->hr_compression != res1->hr_compression)
 380                         return (true);
 381                 if (res0->hr_timeout != res1->hr_timeout)
 382                         return (true);
 383                 if (strcmp(res0->hr_exec, res1->hr_exec) != 0)
 384                         return (true);
 385         }
 386         return (false);
 387 }
 388
 389 static bool
 390 resource_needs_reload(const struct hast_resource *res0,
 391     const struct hast_resource *res1)
 392 {
 393
 394         PJDLOG_ASSERT(strcmp(res0->hr_name, res1->hr_name) == 0);
 395         PJDLOG_ASSERT(strcmp(res0->hr_provname, res1->hr_provname) == 0);
 396         PJDLOG_ASSERT(strcmp(res0->hr_localpath, res1->hr_localpath) == 0);
 397
 398         if (res0->hr_role != HAST_ROLE_PRIMARY)
 399                 return (false);
 400
 401         if (strcmp(res0->hr_remoteaddr, res1->hr_remoteaddr) != 0)
 402                 return (true);
 403         if (strcmp(res0->hr_sourceaddr, res1->hr_sourceaddr) != 0)
 404                 return (true);
 405         if (res0->hr_replication != res1->hr_replication)
 406                 return (true);
 407         if (res0->hr_checksum != res1->hr_checksum)
 408                 return (true);
 409         if (res0->hr_compression != res1->hr_compression)
 410                 return (true);
 411         if (res0->hr_timeout != res1->hr_timeout)
 412                 return (true);
 413         if (strcmp(res0->hr_exec, res1->hr_exec) != 0)
 414                 return (true);
 415         return (false);
 416 }
 417
 418 static void
 419 resource_reload(const struct hast_resource *res)
 420 {
 421         struct nv *nvin, *nvout;
 422         int error;
 423
 424         PJDLOG_ASSERT(res->hr_role == HAST_ROLE_PRIMARY);
 425
 426         nvout = nv_alloc();
 427         nv_add_uint8(nvout, HASTCTL_RELOAD, "cmd");
 428         nv_add_string(nvout, res->hr_remoteaddr, "remoteaddr");
 429         nv_add_string(nvout, res->hr_sourceaddr, "sourceaddr");
 430         nv_add_int32(nvout, (int32_t)res->hr_replication, "replication");
 431         nv_add_int32(nvout, (int32_t)res->hr_checksum, "checksum");
 432         nv_add_int32(nvout, (int32_t)res->hr_compression, "compression");
 433         nv_add_int32(nvout, (int32_t)res->hr_timeout, "timeout");
 434         nv_add_string(nvout, res->hr_exec, "exec");
 435         if (nv_error(nvout) != 0) {
 436                 nv_free(nvout);
 437                 pjdlog_error("Unable to allocate header for reload message.");
 438                 return;
 439         }
 440         if (hast_proto_send(res, res->hr_ctrl, nvout, NULL, 0) < 0) {
 441                 pjdlog_errno(LOG_ERR, "Unable to send reload message");
 442                 nv_free(nvout);
 443                 return;
 444         }
 445         nv_free(nvout);
 446
 447         /* Receive response. */
 448         if (hast_proto_recv_hdr(res->hr_ctrl, &nvin) < 0) {
 449                 pjdlog_errno(LOG_ERR, "Unable to receive reload reply");
 450                 return;
 451         }
 452         error = nv_get_int16(nvin, "error");
 453         nv_free(nvin);
 454         if (error != 0) {
 455                 pjdlog_common(LOG_ERR, 0, error, "Reload failed");
 456                 return;
 457         }
 458 }
 459
 460 static void
 461 hastd_reload(void)
 462 {
 463         struct hastd_config *newcfg;
 464         struct hast_resource *nres, *cres, *tres;
 465         uint8_t role;
 466
 467         pjdlog_info("Reloading configuration...");
 468
 469         newcfg = yy_config_parse(cfgpath, false);
 470         if (newcfg == NULL)
 471                 goto failed;
 472
 473         /*
 474          * Check if control address has changed.
 475          */
 476         if (strcmp(cfg->hc_controladdr, newcfg->hc_controladdr) != 0) {
 477                 if (proto_server(newcfg->hc_controladdr,
 478                     &newcfg->hc_controlconn) < 0) {
 479                         pjdlog_errno(LOG_ERR,
 480                             "Unable to listen on control address %s",
 481                             newcfg->hc_controladdr);
 482                         goto failed;
 483                 }
 484         }
 485         /*
 486          * Check if listen address has changed.
 487          */
 488         if (strcmp(cfg->hc_listenaddr, newcfg->hc_listenaddr) != 0) {
 489                 if (proto_server(newcfg->hc_listenaddr,
 490                     &newcfg->hc_listenconn) < 0) {
 491                         pjdlog_errno(LOG_ERR, "Unable to listen on address %s",
 492                             newcfg->hc_listenaddr);
 493                         goto failed;
 494                 }
 495         }
 496         /*
 497          * Only when both control and listen sockets are successfully
 498          * initialized switch them to new configuration.
 499          */
 500         if (newcfg->hc_controlconn != NULL) {
 501                 pjdlog_info("Control socket changed from %s to %s.",
 502                     cfg->hc_controladdr, newcfg->hc_controladdr);
 503                 proto_close(cfg->hc_controlconn);
 504                 cfg->hc_controlconn = newcfg->hc_controlconn;
 505                 newcfg->hc_controlconn = NULL;
 506                 strlcpy(cfg->hc_controladdr, newcfg->hc_controladdr,
 507                     sizeof(cfg->hc_controladdr));
 508         }
 509         if (newcfg->hc_listenconn != NULL) {
 510                 pjdlog_info("Listen socket changed from %s to %s.",
 511                     cfg->hc_listenaddr, newcfg->hc_listenaddr);
 512                 proto_close(cfg->hc_listenconn);
 513                 cfg->hc_listenconn = newcfg->hc_listenconn;
 514                 newcfg->hc_listenconn = NULL;
 515                 strlcpy(cfg->hc_listenaddr, newcfg->hc_listenaddr,
 516                     sizeof(cfg->hc_listenaddr));
 517         }
 518
 519         /*
 520          * Stop and remove resources that were removed from the configuration.
 521          */
 522         TAILQ_FOREACH_SAFE(cres, &cfg->hc_resources, hr_next, tres) {
 523                 TAILQ_FOREACH(nres, &newcfg->hc_resources, hr_next) {
 524                         if (strcmp(cres->hr_name, nres->hr_name) == 0)
 525                                 break;
 526                 }
 527                 if (nres == NULL) {
 528                         control_set_role(cres, HAST_ROLE_INIT);
 529                         TAILQ_REMOVE(&cfg->hc_resources, cres, hr_next);
 530                         pjdlog_info("Resource %s removed.", cres->hr_name);
 531                         free(cres);
 532                 }
 533         }
 534         /*
 535          * Move new resources to the current configuration.
 536          */
 537         TAILQ_FOREACH_SAFE(nres, &newcfg->hc_resources, hr_next, tres) {
 538                 TAILQ_FOREACH(cres, &cfg->hc_resources, hr_next) {
 539                         if (strcmp(cres->hr_name, nres->hr_name) == 0)
 540                                 break;
 541                 }
 542                 if (cres == NULL) {
 543                         TAILQ_REMOVE(&newcfg->hc_resources, nres, hr_next);
 544                         TAILQ_INSERT_TAIL(&cfg->hc_resources, nres, hr_next);
 545                         pjdlog_info("Resource %s added.", nres->hr_name);
 546                 }
 547         }
 548         /*
 549          * Deal with modified resources.
 550          * Depending on what has changed exactly we might want to perform
 551          * different actions.
 552          *
 553          * We do full resource restart in the following situations:
 554          * Resource role is INIT or SECONDARY.
 555          * Resource role is PRIMARY and path to local component or provider
 556          * name has changed.
 557          * In case of PRIMARY, the worker process will be killed and restarted,
 558          * which also means removing /dev/hast/<name> provider and
 559          * recreating it.
 560          *
 561          * We do just reload (send SIGHUP to worker process) if we act as
 562          * PRIMARY, but only if remote address, replication mode, timeout or
 563          * execution path has changed. For those, there is no need to restart
 564          * worker process.
 565          * If PRIMARY receives SIGHUP, it will reconnect if remote address or
 566          * replication mode has changed or simply set new timeout if only
 567          * timeout has changed.
 568          */
 569         TAILQ_FOREACH_SAFE(nres, &newcfg->hc_resources, hr_next, tres) {
 570                 TAILQ_FOREACH(cres, &cfg->hc_resources, hr_next) {
 571                         if (strcmp(cres->hr_name, nres->hr_name) == 0)
 572                                 break;
 573                 }
 574                 PJDLOG_ASSERT(cres != NULL);
 575                 if (resource_needs_restart(cres, nres)) {
 576                         pjdlog_info("Resource %s configuration was modified, restarting it.",
 577                             cres->hr_name);
 578                         role = cres->hr_role;
 579                         control_set_role(cres, HAST_ROLE_INIT);
 580                         TAILQ_REMOVE(&cfg->hc_resources, cres, hr_next);
 581                         free(cres);
 582                         TAILQ_REMOVE(&newcfg->hc_resources, nres, hr_next);
 583                         TAILQ_INSERT_TAIL(&cfg->hc_resources, nres, hr_next);
 584                         control_set_role(nres, role);
 585                 } else if (resource_needs_reload(cres, nres)) {
 586                         pjdlog_info("Resource %s configuration was modified, reloading it.",
 587                             cres->hr_name);
 588                         strlcpy(cres->hr_remoteaddr, nres->hr_remoteaddr,
 589                             sizeof(cres->hr_remoteaddr));
 590                         strlcpy(cres->hr_sourceaddr, nres->hr_sourceaddr,
 591                             sizeof(cres->hr_sourceaddr));
 592                         cres->hr_replication = nres->hr_replication;
 593                         cres->hr_checksum = nres->hr_checksum;
 594                         cres->hr_compression = nres->hr_compression;
 595                         cres->hr_timeout = nres->hr_timeout;
 596                         strlcpy(cres->hr_exec, nres->hr_exec,
 597                             sizeof(cres->hr_exec));
 598                         if (cres->hr_workerpid != 0)
 599                                 resource_reload(cres);
 600                 }
 601         }
 602
 603         yy_config_free(newcfg);
 604         pjdlog_info("Configuration reloaded successfully.");
 605         return;
 606 failed:
 607         if (newcfg != NULL) {
 608                 if (newcfg->hc_controlconn != NULL)
 609                         proto_close(newcfg->hc_controlconn);
 610                 if (newcfg->hc_listenconn != NULL)
 611                         proto_close(newcfg->hc_listenconn);
 612                 yy_config_free(newcfg);
 613         }
 614         pjdlog_warning("Configuration not reloaded.");
 615 }
 616
 617 static void
 618 terminate_workers(void)
 619 {
 620         struct hast_resource *res;
 621
 622         pjdlog_info("Termination signal received, exiting.");
 623         TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
 624                 if (res->hr_workerpid == 0)
 625                         continue;
 626                 pjdlog_info("Terminating worker process (resource=%s, role=%s, pid=%u).",
 627                     res->hr_name, role2str(res->hr_role), res->hr_workerpid);
 628                 if (kill(res->hr_workerpid, SIGTERM) == 0)
 629                         continue;
 630                 pjdlog_errno(LOG_WARNING,
 631                     "Unable to send signal to worker process (resource=%s, role=%s, pid=%u).",
 632                     res->hr_name, role2str(res->hr_role), res->hr_workerpid);
 633         }
 634 }
 635
 636 static void
 637 listen_accept(void)
 638 {
 639         struct hast_resource *res;
 640         struct proto_conn *conn;
 641         struct nv *nvin, *nvout, *nverr;
 642         const char *resname;
 643         const unsigned char *token;
 644         char laddr[256], raddr[256];
 645         size_t size;
 646         pid_t pid;
 647         int status;
 648
 649         proto_local_address(cfg->hc_listenconn, laddr, sizeof(laddr));
 650         pjdlog_debug(1, "Accepting connection to %s.", laddr);
 651
 652         if (proto_accept(cfg->hc_listenconn, &conn) < 0) {
 653                 pjdlog_errno(LOG_ERR, "Unable to accept connection %s", laddr);
 654                 return;
 655         }
 656
 657         proto_local_address(conn, laddr, sizeof(laddr));
 658         proto_remote_address(conn, raddr, sizeof(raddr));
 659         pjdlog_info("Connection from %s to %s.", raddr, laddr);
 660
 661         /* Error in setting timeout is not critical, but why should it fail? */
 662         if (proto_timeout(conn, HAST_TIMEOUT) < 0)
 663                 pjdlog_errno(LOG_WARNING, "Unable to set connection timeout");
 664
 665         nvin = nvout = nverr = NULL;
 666
 667         /*
 668          * Before receiving any data see if remote host have access to any
 669          * resource.
 670          */
 671         TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
 672                 if (proto_address_match(conn, res->hr_remoteaddr))
 673                         break;
 674         }
 675         if (res == NULL) {
 676                 pjdlog_error("Client %s isn't known.", raddr);
 677                 goto close;
 678         }
 679         /* Ok, remote host can access at least one resource. */
 680
 681         if (hast_proto_recv_hdr(conn, &nvin) < 0) {
 682                 pjdlog_errno(LOG_ERR, "Unable to receive header from %s",
 683                     raddr);
 684                 goto close;
 685         }
 686
 687         resname = nv_get_string(nvin, "resource");
 688         if (resname == NULL) {
 689                 pjdlog_error("No 'resource' field in the header received from %s.",
 690                     raddr);
 691                 goto close;
 692         }
 693         pjdlog_debug(2, "%s: resource=%s", raddr, resname);
 694         token = nv_get_uint8_array(nvin, &size, "token");
 695         /*
 696          * NULL token means that this is first conection.
 697          */
 698         if (token != NULL && size != sizeof(res->hr_token)) {
 699                 pjdlog_error("Received token of invalid size from %s (expected %zu, got %zu).",
 700                     raddr, sizeof(res->hr_token), size);
 701                 goto close;
 702         }
 703
 704         /*
 705          * From now on we want to send errors to the remote node.
 706          */
 707         nverr = nv_alloc();
 708
 709         /* Find resource related to this connection. */
 710         TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
 711                 if (strcmp(resname, res->hr_name) == 0)
 712                         break;
 713         }
 714         /* Have we found the resource? */
 715         if (res == NULL) {
 716                 pjdlog_error("No resource '%s' as requested by %s.",
 717                     resname, raddr);
 718                 nv_add_stringf(nverr, "errmsg", "Resource not configured.");
 719                 goto fail;
 720         }
 721
 722         /* Now that we know resource name setup log prefix. */
 723         pjdlog_prefix_set("[%s] (%s) ", res->hr_name, role2str(res->hr_role));
 724
 725         /* Does the remote host have access to this resource? */
 726         if (!proto_address_match(conn, res->hr_remoteaddr)) {
 727                 pjdlog_error("Client %s has no access to the resource.", raddr);
 728                 nv_add_stringf(nverr, "errmsg", "No access to the resource.");
 729                 goto fail;
 730         }
 731         /* Is the resource marked as secondary? */
 732         if (res->hr_role != HAST_ROLE_SECONDARY) {
 733                 pjdlog_warning("We act as %s for the resource and not as %s as requested by %s.",
 734                     role2str(res->hr_role), role2str(HAST_ROLE_SECONDARY),
 735                     raddr);
 736                 nv_add_stringf(nverr, "errmsg",
 737                     "Remote node acts as %s for the resource and not as %s.",
 738                     role2str(res->hr_role), role2str(HAST_ROLE_SECONDARY));
 739                 if (res->hr_role == HAST_ROLE_PRIMARY) {
 740                         /*
 741                          * If we act as primary request the other side to wait
 742                          * for us a bit, as we might be finishing cleanups.
 743                          */
 744                         nv_add_uint8(nverr, 1, "wait");
 745                 }
 746                 goto fail;
 747         }
 748         /* Does token (if exists) match? */
 749         if (token != NULL && memcmp(token, res->hr_token,
 750             sizeof(res->hr_token)) != 0) {
 751                 pjdlog_error("Token received from %s doesn't match.", raddr);
 752                 nv_add_stringf(nverr, "errmsg", "Token doesn't match.");
 753                 goto fail;
 754         }
 755         /*
 756          * If there is no token, but we have half-open connection
 757          * (only remotein) or full connection (worker process is running)
 758          * we have to cancel those and accept the new connection.
 759          */
 760         if (token == NULL) {
 761                 PJDLOG_ASSERT(res->hr_remoteout == NULL);
 762                 pjdlog_debug(1, "Initial connection from %s.", raddr);
 763                 if (res->hr_workerpid != 0) {
 764                         PJDLOG_ASSERT(res->hr_remotein == NULL);
 765                         pjdlog_debug(1,
 766                             "Worker process exists (pid=%u), stopping it.",
 767                             (unsigned int)res->hr_workerpid);
 768                         /* Stop child process. */
 769                         if (kill(res->hr_workerpid, SIGINT) < 0) {
 770                                 pjdlog_errno(LOG_ERR,
 771                                     "Unable to stop worker process (pid=%u)",
 772                                     (unsigned int)res->hr_workerpid);
 773                                 /*
 774                                  * Other than logging the problem we
 775                                  * ignore it - nothing smart to do.
 776                                  */
 777                         }
 778                         /* Wait for it to exit. */
 779                         else if ((pid = waitpid(res->hr_workerpid,
 780                             &status, 0)) != res->hr_workerpid) {
 781                                 /* We can only log the problem. */
 782                                 pjdlog_errno(LOG_ERR,
 783                                     "Waiting for worker process (pid=%u) failed",
 784                                     (unsigned int)res->hr_workerpid);
 785                         } else {
 786                                 child_exit_log(res->hr_workerpid, status);
 787                         }
 788                         child_cleanup(res);
 789                 } else if (res->hr_remotein != NULL) {
 790                         char oaddr[256];
 791
 792                         proto_remote_address(res->hr_remotein, oaddr,
 793                             sizeof(oaddr));
 794                         pjdlog_debug(1,
 795                             "Canceling half-open connection from %s on connection from %s.",
 796                             oaddr, raddr);
 797                         proto_close(res->hr_remotein);
 798                         res->hr_remotein = NULL;
 799                 }
 800         }
 801
 802         /*
 803          * Checks and cleanups are done.
 804          */
 805
 806         if (token == NULL) {
 807                 arc4random_buf(res->hr_token, sizeof(res->hr_token));
 808                 nvout = nv_alloc();
 809                 nv_add_uint8_array(nvout, res->hr_token,
 810                     sizeof(res->hr_token), "token");
 811                 if (nv_error(nvout) != 0) {
 812                         pjdlog_common(LOG_ERR, 0, nv_error(nvout),
 813                             "Unable to prepare return header for %s", raddr);
 814                         nv_add_stringf(nverr, "errmsg",
 815                             "Remote node was unable to prepare return header: %s.",
 816                             strerror(nv_error(nvout)));
 817                         goto fail;
 818                 }
 819                 if (hast_proto_send(NULL, conn, nvout, NULL, 0) < 0) {
 820                         int error = errno;
 821
 822                         pjdlog_errno(LOG_ERR, "Unable to send response to %s",
 823                             raddr);
 824                         nv_add_stringf(nverr, "errmsg",
 825                             "Remote node was unable to send response: %s.",
 826                             strerror(error));
 827                         goto fail;
 828                 }
 829                 res->hr_remotein = conn;
 830                 pjdlog_debug(1, "Incoming connection from %s configured.",
 831                     raddr);
 832         } else {
 833                 res->hr_remoteout = conn;
 834                 pjdlog_debug(1, "Outgoing connection to %s configured.", raddr);
 835                 hastd_secondary(res, nvin);
 836         }
 837         nv_free(nvin);
 838         nv_free(nvout);
 839         nv_free(nverr);
 840         pjdlog_prefix_set("%s", "");
 841         return;
 842 fail:
 843         if (nv_error(nverr) != 0) {
 844                 pjdlog_common(LOG_ERR, 0, nv_error(nverr),
 845                     "Unable to prepare error header for %s", raddr);
 846                 goto close;
 847         }
 848         if (hast_proto_send(NULL, conn, nverr, NULL, 0) < 0) {
 849                 pjdlog_errno(LOG_ERR, "Unable to send error to %s", raddr);
 850                 goto close;
 851         }
 852 close:
 853         if (nvin != NULL)
 854                 nv_free(nvin);
 855         if (nvout != NULL)
 856                 nv_free(nvout);
 857         if (nverr != NULL)
 858                 nv_free(nverr);
 859         proto_close(conn);
 860         pjdlog_prefix_set("%s", "");
 861 }
 862
 863 static void
 864 connection_migrate(struct hast_resource *res)
 865 {
 866         struct proto_conn *conn;
 867         int16_t val = 0;
 868
 869         pjdlog_prefix_set("[%s] (%s) ", res->hr_name, role2str(res->hr_role));
 870
 871         PJDLOG_ASSERT(res->hr_role == HAST_ROLE_PRIMARY);
 872
 873         if (proto_recv(res->hr_conn, &val, sizeof(val)) < 0) {
 874                 pjdlog_errno(LOG_WARNING,
 875                     "Unable to receive connection command");
 876                 return;
 877         }
 878         if (proto_client(res->hr_sourceaddr[0] != '\0' ? res->hr_sourceaddr : NULL,
 879             res->hr_remoteaddr, &conn) < 0) {
 880                 val = errno;
 881                 pjdlog_errno(LOG_WARNING,
 882                     "Unable to create outgoing connection to %s",
 883                     res->hr_remoteaddr);
 884                 goto out;
 885         }
 886         if (proto_connect(conn, -1) < 0) {
 887                 val = errno;
 888                 pjdlog_errno(LOG_WARNING, "Unable to connect to %s",
 889                     res->hr_remoteaddr);
 890                 proto_close(conn);
 891                 goto out;
 892         }
 893         val = 0;
 894 out:
 895         if (proto_send(res->hr_conn, &val, sizeof(val)) < 0) {
 896                 pjdlog_errno(LOG_WARNING,
 897                     "Unable to send reply to connection request");
 898         }
 899         if (val == 0 && proto_connection_send(res->hr_conn, conn) < 0)
 900                 pjdlog_errno(LOG_WARNING, "Unable to send connection");
 901
 902         pjdlog_prefix_set("%s", "");
 903 }
 904
 905 static void
 906 check_signals(void)
 907 {
 908         struct timespec sigtimeout;
 909         sigset_t mask;
 910         int signo;
 911
 912         sigtimeout.tv_sec = 0;
 913         sigtimeout.tv_nsec = 0;
 914
 915         PJDLOG_VERIFY(sigemptyset(&mask) == 0);
 916         PJDLOG_VERIFY(sigaddset(&mask, SIGHUP) == 0);
 917         PJDLOG_VERIFY(sigaddset(&mask, SIGINT) == 0);
 918         PJDLOG_VERIFY(sigaddset(&mask, SIGTERM) == 0);
 919         PJDLOG_VERIFY(sigaddset(&mask, SIGCHLD) == 0);
 920
 921         while ((signo = sigtimedwait(&mask, NULL, &sigtimeout)) != -1) {
 922                 switch (signo) {
 923                 case SIGINT:
 924                 case SIGTERM:
 925                         sigexit_received = true;
 926                         terminate_workers();
 927                         proto_close(cfg->hc_controlconn);
 928                         exit(EX_OK);
 929                         break;
 930                 case SIGCHLD:
 931                         child_exit();
 932                         break;
 933                 case SIGHUP:
 934                         hastd_reload();
 935                         break;
 936                 default:
 937                         PJDLOG_ABORT("Unexpected signal (%d).", signo);
 938                 }
 939         }
 940 }
 941
 942 static void
 943 main_loop(void)
 944 {
 945         struct hast_resource *res;
 946         struct timeval seltimeout;
 947         int fd, maxfd, ret;
 948         time_t lastcheck, now;
 949         fd_set rfds;
 950
 951         lastcheck = time(NULL);
 952         seltimeout.tv_sec = REPORT_INTERVAL;
 953         seltimeout.tv_usec = 0;
 954
 955         pjdlog_info("Started successfully, running protocol version %d.",
 956             HAST_PROTO_VERSION);
 957
 958         for (;;) {
 959                 check_signals();
 960
 961                 /* Setup descriptors for select(2). */
 962                 FD_ZERO(&rfds);
 963                 maxfd = fd = proto_descriptor(cfg->hc_controlconn);
 964                 PJDLOG_ASSERT(fd >= 0);
 965                 FD_SET(fd, &rfds);
 966                 fd = proto_descriptor(cfg->hc_listenconn);
 967                 PJDLOG_ASSERT(fd >= 0);
 968                 FD_SET(fd, &rfds);
 969                 maxfd = fd > maxfd ? fd : maxfd;
 970                 TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
 971                         if (res->hr_event == NULL)
 972                                 continue;
 973                         fd = proto_descriptor(res->hr_event);
 974                         PJDLOG_ASSERT(fd >= 0);
 975                         FD_SET(fd, &rfds);
 976                         maxfd = fd > maxfd ? fd : maxfd;
 977                         if (res->hr_role == HAST_ROLE_PRIMARY) {
 978                                 /* Only primary workers asks for connections. */
 979                                 PJDLOG_ASSERT(res->hr_conn != NULL);
 980                                 fd = proto_descriptor(res->hr_conn);
 981                                 PJDLOG_ASSERT(fd >= 0);
 982                                 FD_SET(fd, &rfds);
 983                                 maxfd = fd > maxfd ? fd : maxfd;
 984                         } else {
 985                                 PJDLOG_ASSERT(res->hr_conn == NULL);
 986                         }
 987                 }
 988
 989                 PJDLOG_ASSERT(maxfd + 1 <= (int)FD_SETSIZE);
 990                 ret = select(maxfd + 1, &rfds, NULL, NULL, &seltimeout);
 991                 now = time(NULL);
 992                 if (lastcheck + REPORT_INTERVAL <= now) {
 993                         hook_check();
 994                         lastcheck = now;
 995                 }
 996                 if (ret == 0) {
 997                         /*
 998                          * select(2) timed out, so there should be no
 999                          * descriptors to check.
1000                          */
1001                         continue;
1002                 } else if (ret == -1) {
1003                         if (errno == EINTR)
1004                                 continue;
1005                         KEEP_ERRNO((void)pidfile_remove(pfh));
1006                         pjdlog_exit(EX_OSERR, "select() failed");
1007                 }
1008
1009                 /*
1010                  * Check for signals before we do anything to update our
1011                  * info about terminated workers in the meantime.
1012                  */
1013                 check_signals();
1014
1015                 if (FD_ISSET(proto_descriptor(cfg->hc_controlconn), &rfds))
1016                         control_handle(cfg);
1017                 if (FD_ISSET(proto_descriptor(cfg->hc_listenconn), &rfds))
1018                         listen_accept();
1019                 TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) {
1020                         if (res->hr_event == NULL)
1021                                 continue;
1022                         if (FD_ISSET(proto_descriptor(res->hr_event), &rfds)) {
1023                                 if (event_recv(res) == 0)
1024                                         continue;
1025                                 /* The worker process exited? */
1026                                 proto_close(res->hr_event);
1027                                 res->hr_event = NULL;
1028                                 if (res->hr_conn != NULL) {
1029                                         proto_close(res->hr_conn);
1030                                         res->hr_conn = NULL;
1031                                 }
1032                                 continue;
1033                         }
1034                         if (res->hr_role == HAST_ROLE_PRIMARY) {
1035                                 PJDLOG_ASSERT(res->hr_conn != NULL);
1036                                 if (FD_ISSET(proto_descriptor(res->hr_conn),
1037                                     &rfds)) {
1038                                         connection_migrate(res);
1039                                 }
1040                         } else {
1041                                 PJDLOG_ASSERT(res->hr_conn == NULL);
1042                         }
1043                 }
1044         }
1045 }
1046
1047 static void
1048 dummy_sighandler(int sig __unused)
1049 {
1050         /* Nothing to do. */
1051 }
1052
1053 int
1054 main(int argc, char *argv[])
1055 {
1056         const char *pidfile;
1057         pid_t otherpid;
1058         bool foreground;
1059         int debuglevel;
1060         sigset_t mask;
1061
1062         foreground = false;
1063         debuglevel = 0;
1064         pidfile = HASTD_PIDFILE;
1065
1066         for (;;) {
1067                 int ch;
1068
1069                 ch = getopt(argc, argv, "c:dFhP:");
1070                 if (ch == -1)
1071                         break;
1072                 switch (ch) {
1073                 case 'c':
1074                         cfgpath = optarg;
1075                         break;
1076                 case 'd':
1077                         debuglevel++;
1078                         break;
1079                 case 'F':
1080                         foreground = true;
1081                         break;
1082                 case 'P':
1083                         pidfile = optarg;
1084                         break;
1085                 case 'h':
1086                 default:
1087                         usage();
1088                 }
1089         }
1090         argc -= optind;
1091         argv += optind;
1092
1093         pjdlog_init(PJDLOG_MODE_STD);
1094         pjdlog_debug_set(debuglevel);
1095
1096         g_gate_load();
1097
1098         pfh = pidfile_open(pidfile, 0600, &otherpid);
1099         if (pfh == NULL) {
1100                 if (errno == EEXIST) {
1101                         pjdlog_exitx(EX_TEMPFAIL,
1102                             "Another hastd is already running, pid: %jd.",
1103                             (intmax_t)otherpid);
1104                 }
1105                 /* If we cannot create pidfile from other reasons, only warn. */
1106                 pjdlog_errno(LOG_WARNING, "Unable to open or create pidfile");
1107         }
1108
1109         cfg = yy_config_parse(cfgpath, true);
1110         PJDLOG_ASSERT(cfg != NULL);
1111
1112         /*
1113          * Restore default actions for interesting signals in case parent
1114          * process (like init(8)) decided to ignore some of them (like SIGHUP).
1115          */
1116         PJDLOG_VERIFY(signal(SIGHUP, SIG_DFL) != SIG_ERR);
1117         PJDLOG_VERIFY(signal(SIGINT, SIG_DFL) != SIG_ERR);
1118         PJDLOG_VERIFY(signal(SIGTERM, SIG_DFL) != SIG_ERR);
1119         /*
1120          * Because SIGCHLD is ignored by default, setup dummy handler for it,
1121          * so we can mask it.
1122          */
1123         PJDLOG_VERIFY(signal(SIGCHLD, dummy_sighandler) != SIG_ERR);
1124
1125         PJDLOG_VERIFY(sigemptyset(&mask) == 0);
1126         PJDLOG_VERIFY(sigaddset(&mask, SIGHUP) == 0);
1127         PJDLOG_VERIFY(sigaddset(&mask, SIGINT) == 0);
1128         PJDLOG_VERIFY(sigaddset(&mask, SIGTERM) == 0);
1129         PJDLOG_VERIFY(sigaddset(&mask, SIGCHLD) == 0);
1130         PJDLOG_VERIFY(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
1131
1132         /* Listen on control address. */
1133         if (proto_server(cfg->hc_controladdr, &cfg->hc_controlconn) < 0) {
1134                 KEEP_ERRNO((void)pidfile_remove(pfh));
1135                 pjdlog_exit(EX_OSERR, "Unable to listen on control address %s",
1136                     cfg->hc_controladdr);
1137         }
1138         /* Listen for remote connections. */
1139         if (proto_server(cfg->hc_listenaddr, &cfg->hc_listenconn) < 0) {
1140                 KEEP_ERRNO((void)pidfile_remove(pfh));
1141                 pjdlog_exit(EX_OSERR, "Unable to listen on address %s",
1142                     cfg->hc_listenaddr);
1143         }
1144
1145         if (!foreground) {
1146                 if (daemon(0, 0) < 0) {
1147                         KEEP_ERRNO((void)pidfile_remove(pfh));
1148                         pjdlog_exit(EX_OSERR, "Unable to daemonize");
1149                 }
1150
1151                 /* Start logging to syslog. */
1152                 pjdlog_mode_set(PJDLOG_MODE_SYSLOG);
1153
1154                 /* Write PID to a file. */
1155                 if (pidfile_write(pfh) < 0) {
1156                         pjdlog_errno(LOG_WARNING,
1157                             "Unable to write PID to a file");
1158                 }
1159         }
1160
1161         hook_init();
1162
1163         main_loop();
1164
1165         exit(0);
1166 }