lib/services/systemd.c

/* */
This source file includes following definitions.
services__systemd_prepare
services__systemd2ocf
systemd_new_method
systemd_send
systemd_send_recv
systemd_call_simple_method
systemd_init
systemd_get_property
systemd_cleanup
systemd_unit_extension
systemd_service_name
systemd_daemon_reload_complete
systemd_daemon_reload
set_result_from_method_error
execute_after_loadunit
loadunit_completed
invoke_unit_by_name
sort_str
systemd_unit_listall
systemd_unit_exists
systemd_unit_metadata
process_unit_method_reply
unit_method_complete
create_world_readable
create_override_dir
get_override_filename
systemd_create_override
systemd_remove_override
parse_status_result
invoke_unit_by_path
systemd_timeout_callback
services__execute_systemd
   1 /*
   2  * Copyright 2012-2022 the Pacemaker project contributors
   3  *
   4  * The version control history for this file may have further details.
   5  *
   6  * This source code is licensed under the GNU Lesser General Public License
   7  * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
   8  */
   9 
  10 #include <crm_internal.h>
  11 #include <crm/crm.h>
  12 #include <crm/services.h>
  13 #include <crm/services_internal.h>
  14 #include <crm/common/mainloop.h>
  15 
  16 #include <sys/stat.h>
  17 #include <gio/gio.h>
  18 #include <services_private.h>
  19 #include <systemd.h>
  20 #include <dbus/dbus.h>
  21 #include <pcmk-dbus.h>
  22 
  23 static void invoke_unit_by_path(svc_action_t *op, const char *unit);
  24 
  25 #define BUS_NAME         "org.freedesktop.systemd1"
  26 #define BUS_NAME_MANAGER BUS_NAME ".Manager"
  27 #define BUS_NAME_UNIT    BUS_NAME ".Unit"
  28 #define BUS_PATH         "/org/freedesktop/systemd1"
  29 
  30 /*!
  31  * \internal
  32  * \brief Prepare a systemd action
  33  *
  34  * \param[in] op  Action to prepare
  35  *
  36  * \return Standard Pacemaker return code
  37  */
  38 int
  39 services__systemd_prepare(svc_action_t *op)
     /*  */
  40 {
  41     op->opaque->exec = strdup("systemd-dbus");
  42     if (op->opaque->exec == NULL) {
  43         return ENOMEM;
  44     }
  45     return pcmk_rc_ok;
  46 }
  47 
  48 /*!
  49  * \internal
  50  * \brief Map a systemd result to a standard OCF result
  51  *
  52  * \param[in] exit_status  Systemd result
  53  *
  54  * \return Standard OCF result
  55  */
  56 enum ocf_exitcode
  57 services__systemd2ocf(int exit_status)
     /*  */
  58 {
  59     // This library uses OCF codes for systemd actions
  60     return (enum ocf_exitcode) exit_status;
  61 }
  62 
  63 static inline DBusMessage *
  64 systemd_new_method(const char *method)
     /*  */
  65 {
  66     crm_trace("Calling: %s on " BUS_NAME_MANAGER, method);
  67     return dbus_message_new_method_call(BUS_NAME, BUS_PATH, BUS_NAME_MANAGER,
  68                                         method);
  69 }
  70 
  71 /*
  72  * Functions to manage a static DBus connection
  73  */
  74 
  75 static DBusConnection* systemd_proxy = NULL;
  76 
  77 static inline DBusPendingCall *
  78 systemd_send(DBusMessage *msg,
     /*  */
  79              void(*done)(DBusPendingCall *pending, void *user_data),
  80              void *user_data, int timeout)
  81 {
  82     return pcmk_dbus_send(msg, systemd_proxy, done, user_data, timeout);
  83 }
  84 
  85 static inline DBusMessage *
  86 systemd_send_recv(DBusMessage *msg, DBusError *error, int timeout)
     /*  */
  87 {
  88     return pcmk_dbus_send_recv(msg, systemd_proxy, error, timeout);
  89 }
  90 
  91 /*!
  92  * \internal
  93  * \brief Send a method to systemd without arguments, and wait for reply
  94  *
  95  * \param[in] method  Method to send
  96  *
  97  * \return Systemd reply on success, NULL (and error will be logged) otherwise
  98  *
  99  * \note The caller must call dbus_message_unref() on the reply after
 100  *       handling it.
 101  */
 102 static DBusMessage *
 103 systemd_call_simple_method(const char *method)
     /*  */
 104 {
 105     DBusMessage *msg = systemd_new_method(method);
 106     DBusMessage *reply = NULL;
 107     DBusError error;
 108 
 109     /* Don't call systemd_init() here, because that calls this */
 110     CRM_CHECK(systemd_proxy, return NULL);
 111 
 112     if (msg == NULL) {
 113         crm_err("Could not create message to send %s to systemd", method);
 114         return NULL;
 115     }
 116 
 117     dbus_error_init(&error);
 118     reply = systemd_send_recv(msg, &error, DBUS_TIMEOUT_USE_DEFAULT);
 119     dbus_message_unref(msg);
 120 
 121     if (dbus_error_is_set(&error)) {
 122         crm_err("Could not send %s to systemd: %s (%s)",
 123                 method, error.message, error.name);
 124         dbus_error_free(&error);
 125         return NULL;
 126 
 127     } else if (reply == NULL) {
 128         crm_err("Could not send %s to systemd: no reply received", method);
 129         return NULL;
 130     }
 131 
 132     return reply;
 133 }
 134 
 135 static gboolean
 136 systemd_init(void)
     /*  */
 137 {
 138     static int need_init = 1;
 139     // https://dbus.freedesktop.org/doc/api/html/group__DBusConnection.html
 140 
 141     if (systemd_proxy
 142         && dbus_connection_get_is_connected(systemd_proxy) == FALSE) {
 143         crm_warn("Connection to System DBus is closed. Reconnecting...");
 144         pcmk_dbus_disconnect(systemd_proxy);
 145         systemd_proxy = NULL;
 146         need_init = 1;
 147     }
 148 
 149     if (need_init) {
 150         need_init = 0;
 151         systemd_proxy = pcmk_dbus_connect();
 152     }
 153     if (systemd_proxy == NULL) {
 154         return FALSE;
 155     }
 156     return TRUE;
 157 }
 158 
 159 static inline char *
 160 systemd_get_property(const char *unit, const char *name,
     /*  */
 161                      void (*callback)(const char *name, const char *value, void *userdata),
 162                      void *userdata, DBusPendingCall **pending, int timeout)
 163 {
 164     return systemd_proxy?
 165            pcmk_dbus_get_property(systemd_proxy, BUS_NAME, unit, BUS_NAME_UNIT,
 166                                   name, callback, userdata, pending, timeout)
 167            : NULL;
 168 }
 169 
 170 void
 171 systemd_cleanup(void)
     /*  */
 172 {
 173     if (systemd_proxy) {
 174         pcmk_dbus_disconnect(systemd_proxy);
 175         systemd_proxy = NULL;
 176     }
 177 }
 178 
 179 /*
 180  * end of systemd_proxy functions
 181  */
 182 
 183 /*!
 184  * \internal
 185  * \brief Check whether a file name represents a manageable systemd unit
 186  *
 187  * \param[in] name  File name to check
 188  *
 189  * \return Pointer to "dot" before filename extension if so, NULL otherwise
 190  */
 191 static const char *
 192 systemd_unit_extension(const char *name)
     /*  */
 193 {
 194     if (name) {
 195         const char *dot = strrchr(name, '.');
 196 
 197         if (dot && (!strcmp(dot, ".service")
 198                     || !strcmp(dot, ".socket")
 199                     || !strcmp(dot, ".mount")
 200                     || !strcmp(dot, ".timer")
 201                     || !strcmp(dot, ".path"))) {
 202             return dot;
 203         }
 204     }
 205     return NULL;
 206 }
 207 
 208 static char *
 209 systemd_service_name(const char *name, bool add_instance_name)
     /*  */
 210 {
 211     const char *dot = NULL;
 212 
 213     if (pcmk__str_empty(name)) {
 214         return NULL;
 215     }
 216 
 217     /* Services that end with an @ sign are systemd templates.  They expect an
 218      * instance name to follow the service name.  If no instance name was
 219      * provided, just add "pacemaker" to the string as the instance name.  It
 220      * doesn't seem to matter for purposes of looking up whether a service
 221      * exists or not.
 222      *
 223      * A template can be specified either with or without the unit extension,
 224      * so this block handles both cases.
 225      */
 226     dot = systemd_unit_extension(name);
 227 
 228     if (dot) {
 229         if (dot != name && *(dot-1) == '@') {
 230             char *s = NULL;
 231 
 232             if (asprintf(&s, "%.*spacemaker%s", (int) (dot-name), name, dot) == -1) {
 233                 /* If asprintf fails, just return name. */
 234                 return strdup(name);
 235             }
 236 
 237             return s;
 238         } else {
 239             return strdup(name);
 240         }
 241 
 242     } else if (add_instance_name && *(name+strlen(name)-1) == '@') {
 243         return crm_strdup_printf("%spacemaker.service", name);
 244 
 245     } else {
 246         return crm_strdup_printf("%s.service", name);
 247     }
 248 }
 249 
 250 static void
 251 systemd_daemon_reload_complete(DBusPendingCall *pending, void *user_data)
     /*  */
 252 {
 253     DBusError error;
 254     DBusMessage *reply = NULL;
 255     unsigned int reload_count = GPOINTER_TO_UINT(user_data);
 256 
 257     dbus_error_init(&error);
 258     if(pending) {
 259         reply = dbus_pending_call_steal_reply(pending);
 260     }
 261 
 262     if (pcmk_dbus_find_error(pending, reply, &error)) {
 263         crm_warn("Could not issue systemd reload %d: %s",
 264                  reload_count, error.message);
 265         dbus_error_free(&error);
 266 
 267     } else {
 268         crm_trace("Reload %d complete", reload_count);
 269     }
 270 
 271     if(pending) {
 272         dbus_pending_call_unref(pending);
 273     }
 274     if(reply) {
 275         dbus_message_unref(reply);
 276     }
 277 }
 278 
 279 static bool
 280 systemd_daemon_reload(int timeout)
     /*  */
 281 {
 282     static unsigned int reload_count = 0;
 283     DBusMessage *msg = systemd_new_method("Reload");
 284 
 285     reload_count++;
 286     CRM_ASSERT(msg != NULL);
 287     systemd_send(msg, systemd_daemon_reload_complete,
 288                  GUINT_TO_POINTER(reload_count), timeout);
 289     dbus_message_unref(msg);
 290 
 291     return TRUE;
 292 }
 293 
 294 /*!
 295  * \internal
 296  * \brief Set an action result based on a method error
 297  *
 298  * \param[in] op     Action to set result for
 299  * \param[in] error  Method error
 300  */
 301 static void
 302 set_result_from_method_error(svc_action_t *op, const DBusError *error)
     /*  */
 303 {
 304     services__set_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
 305                          "Unable to invoke systemd DBus method");
 306 
 307     if (strstr(error->name, "org.freedesktop.systemd1.InvalidName")
 308         || strstr(error->name, "org.freedesktop.systemd1.LoadFailed")
 309         || strstr(error->name, "org.freedesktop.systemd1.NoSuchUnit")) {
 310 
 311         if (pcmk__str_eq(op->action, "stop", pcmk__str_casei)) {
 312             crm_trace("Masking systemd stop failure (%s) for %s "
 313                       "because unknown service can be considered stopped",
 314                       error->name, crm_str(op->rsc));
 315             services__set_result(op, PCMK_OCF_OK, PCMK_EXEC_DONE, NULL);
 316             return;
 317         }
 318 
 319         services__format_result(op, PCMK_OCF_NOT_INSTALLED,
 320                                PCMK_EXEC_NOT_INSTALLED,
 321                                "systemd unit %s not found", op->agent);
 322     }
 323 
 324     crm_info("DBus request for %s of systemd unit %s for resource %s failed: %s",
 325              op->action, op->agent, crm_str(op->rsc), error->message);
 326 }
 327 
 328 /*!
 329  * \internal
 330  * \brief Extract unit path from LoadUnit reply, and execute action
 331  *
 332  * \param[in] reply  LoadUnit reply
 333  * \param[in] op     Action to execute (or NULL to just return path)
 334  *
 335  * \return DBus object path for specified unit if successful (only valid for
 336  *         lifetime of \p reply), otherwise NULL
 337  */
 338 static const char *
 339 execute_after_loadunit(DBusMessage *reply, svc_action_t *op)
     /*  */
 340 {
 341     const char *path = NULL;
 342     DBusError error;
 343 
 344     /* path here is not used other than as a non-NULL flag to indicate that a
 345      * request was indeed sent
 346      */
 347     if (pcmk_dbus_find_error((void *) &path, reply, &error)) {
 348         if (op != NULL) {
 349             set_result_from_method_error(op, &error);
 350         }
 351         dbus_error_free(&error);
 352 
 353     } else if (!pcmk_dbus_type_check(reply, NULL, DBUS_TYPE_OBJECT_PATH,
 354                                      __func__, __LINE__)) {
 355         if (op != NULL) {
 356             services__set_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
 357                                  "systemd DBus method had unexpected reply");
 358             crm_info("Could not load systemd unit %s for %s: "
 359                      "DBus reply has unexpected type", op->agent, op->id);
 360         } else {
 361             crm_info("Could not load systemd unit: "
 362                      "DBus reply has unexpected type");
 363         }
 364 
 365     } else {
 366         dbus_message_get_args (reply, NULL,
 367                                DBUS_TYPE_OBJECT_PATH, &path,
 368                                DBUS_TYPE_INVALID);
 369     }
 370 
 371     if (op != NULL) {
 372         if (path != NULL) {
 373             invoke_unit_by_path(op, path);
 374 
 375         } else if (!(op->synchronous)) {
 376             services__format_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
 377                                     "No DBus object found for systemd unit %s",
 378                                     op->agent);
 379             services__finalize_async_op(op);
 380         }
 381     }
 382 
 383     return path;
 384 }
 385 
 386 /*!
 387  * \internal
 388  * \brief Execute a systemd action after its LoadUnit completes
 389  *
 390  * \param[in] pending    If not NULL, DBus call associated with LoadUnit request
 391  * \param[in] user_data  Action to execute
 392  */
 393 static void
 394 loadunit_completed(DBusPendingCall *pending, void *user_data)
     /*  */
 395 {
 396     DBusMessage *reply = NULL;
 397     svc_action_t *op = user_data;
 398 
 399     crm_trace("LoadUnit result for %s arrived", op->id);
 400 
 401     // Grab the reply
 402     if (pending != NULL) {
 403         reply = dbus_pending_call_steal_reply(pending);
 404     }
 405 
 406     // The call is no longer pending
 407     CRM_LOG_ASSERT(pending == op->opaque->pending);
 408     services_set_op_pending(op, NULL);
 409 
 410     // Execute the desired action based on the reply
 411     execute_after_loadunit(reply, user_data);
 412     if (reply != NULL) {
 413         dbus_message_unref(reply);
 414     }
 415 }
 416 
 417 /*!
 418  * \internal
 419  * \brief Execute a systemd action, given the unit name
 420  *
 421  * \param[in]  arg_name  Unit name (possibly shortened, i.e. without ".service")
 422  * \param[in]  op        Action to execute (if NULL, just get the object path)
 423  * \param[out] path      If non-NULL and \p op is NULL or synchronous, where to
 424  *                       store DBus object path for specified unit
 425  *
 426  * \return Standard Pacemaker return code (for NULL \p op, pcmk_rc_ok means unit
 427  *         was found; for synchronous actions, pcmk_rc_ok means unit was
 428  *         executed, with the actual result stored in \p op; for asynchronous
 429  *         actions, pcmk_rc_ok means action was initiated)
 430  * \note It is the caller's responsibility to free the path.
 431  */
 432 static int
 433 invoke_unit_by_name(const char *arg_name, svc_action_t *op, char **path)
     /*  */
 434 {
 435     DBusMessage *msg;
 436     DBusMessage *reply = NULL;
 437     DBusPendingCall *pending = NULL;
 438     char *name = NULL;
 439 
 440     if (!systemd_init()) {
 441         if (op != NULL) {
 442             services__set_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
 443                                  "No DBus connection");
 444         }
 445         return ENOTCONN;
 446     }
 447 
 448     /* Create a LoadUnit DBus method (equivalent to GetUnit if already loaded),
 449      * which makes the unit usable via further DBus methods.
 450      *
 451      * <method name="LoadUnit">
 452      *  <arg name="name" type="s" direction="in"/>
 453      *  <arg name="unit" type="o" direction="out"/>
 454      * </method>
 455      */
 456     msg = systemd_new_method("LoadUnit");
 457     CRM_ASSERT(msg != NULL);
 458 
 459     // Add the (expanded) unit name as the argument
 460     name = systemd_service_name(arg_name, op == NULL || pcmk__str_eq(op->action, "meta-data", pcmk__str_none));
 461     CRM_LOG_ASSERT(dbus_message_append_args(msg, DBUS_TYPE_STRING, &name,
 462                                             DBUS_TYPE_INVALID));
 463     free(name);
 464 
 465     if ((op == NULL) || op->synchronous) {
 466         // For synchronous ops, wait for a reply and extract the result
 467         const char *unit = NULL;
 468         int rc = pcmk_rc_ok;
 469 
 470         reply = systemd_send_recv(msg, NULL,
 471                                   (op? op->timeout : DBUS_TIMEOUT_USE_DEFAULT));
 472         dbus_message_unref(msg);
 473 
 474         unit = execute_after_loadunit(reply, op);
 475         if (unit == NULL) {
 476             rc = ENOENT;
 477             if (path != NULL) {
 478                 *path = NULL;
 479             }
 480         } else if (path != NULL) {
 481             *path = strdup(unit);
 482             if (*path == NULL) {
 483                 rc = ENOMEM;
 484             }
 485         }
 486 
 487         if (reply != NULL) {
 488             dbus_message_unref(reply);
 489         }
 490         return rc;
 491     }
 492 
 493     // For asynchronous ops, initiate the LoadUnit call and return
 494     pending = systemd_send(msg, loadunit_completed, op, op->timeout);
 495     if (pending == NULL) {
 496         services__set_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
 497                              "Unable to send DBus message");
 498         dbus_message_unref(msg);
 499         return ECOMM;
 500     }
 501 
 502     // LoadUnit was successfully initiated
 503     services__set_result(op, PCMK_OCF_UNKNOWN, PCMK_EXEC_PENDING, NULL);
 504     services_set_op_pending(op, pending);
 505     dbus_message_unref(msg);
 506     return pcmk_rc_ok;
 507 }
 508 
 509 /*!
 510  * \internal
 511  * \brief Compare two strings alphabetically (case-insensitive)
 512  *
 513  * \param[in] a  First string to compare
 514  * \param[in] b  Second string to compare
 515  *
 516  * \return 0 if strings are equal, -1 if a < b, 1 if a > b
 517  *
 518  * \note Usable as a GCompareFunc with g_list_sort().
 519  *       NULL is considered less than non-NULL.
 520  */
 521 static gint
 522 sort_str(gconstpointer a, gconstpointer b)
     /*  */
 523 {
 524     if (!a && !b) {
 525         return 0;
 526     } else if (!a) {
 527         return -1;
 528     } else if (!b) {
 529         return 1;
 530     }
 531     return strcasecmp(a, b);
 532 }
 533 
 534 GList *
 535 systemd_unit_listall(void)
     /*  */
 536 {
 537     int nfiles = 0;
 538     GList *units = NULL;
 539     DBusMessageIter args;
 540     DBusMessageIter unit;
 541     DBusMessageIter elem;
 542     DBusMessage *reply = NULL;
 543 
 544     if (systemd_init() == FALSE) {
 545         return NULL;
 546     }
 547 
 548 /*
 549         "  <method name=\"ListUnitFiles\">\n"                               \
 550         "   <arg name=\"files\" type=\"a(ss)\" direction=\"out\"/>\n" \
 551         "  </method>\n"                                                 \
 552 */
 553 
 554     reply = systemd_call_simple_method("ListUnitFiles");
 555     if (reply == NULL) {
 556         return NULL;
 557     }
 558     if (!dbus_message_iter_init(reply, &args)) {
 559         crm_err("Could not list systemd unit files: systemd reply has no arguments");
 560         dbus_message_unref(reply);
 561         return NULL;
 562     }
 563     if (!pcmk_dbus_type_check(reply, &args, DBUS_TYPE_ARRAY,
 564                               __func__, __LINE__)) {
 565         crm_err("Could not list systemd unit files: systemd reply has invalid arguments");
 566         dbus_message_unref(reply);
 567         return NULL;
 568     }
 569 
 570     dbus_message_iter_recurse(&args, &unit);
 571     for (; dbus_message_iter_get_arg_type(&unit) != DBUS_TYPE_INVALID;
 572         dbus_message_iter_next(&unit)) {
 573 
 574         DBusBasicValue value;
 575         const char *match = NULL;
 576         char *unit_name = NULL;
 577         char *basename = NULL;
 578 
 579         if(!pcmk_dbus_type_check(reply, &unit, DBUS_TYPE_STRUCT, __func__, __LINE__)) {
 580             crm_warn("Skipping systemd reply argument with unexpected type");
 581             continue;
 582         }
 583 
 584         dbus_message_iter_recurse(&unit, &elem);
 585         if(!pcmk_dbus_type_check(reply, &elem, DBUS_TYPE_STRING, __func__, __LINE__)) {
 586             crm_warn("Skipping systemd reply argument with no string");
 587             continue;
 588         }
 589 
 590         dbus_message_iter_get_basic(&elem, &value);
 591         if (value.str == NULL) {
 592             crm_debug("ListUnitFiles reply did not provide a string");
 593             continue;
 594         }
 595         crm_trace("DBus ListUnitFiles listed: %s", value.str);
 596 
 597         match = systemd_unit_extension(value.str);
 598         if (match == NULL) {
 599             // This is not a unit file type we know how to manage
 600             crm_debug("ListUnitFiles entry '%s' is not supported as resource",
 601                       value.str);
 602             continue;
 603         }
 604 
 605         // ListUnitFiles returns full path names, we just want base name
 606         basename = strrchr(value.str, '/');
 607         if (basename) {
 608             basename = basename + 1;
 609         } else {
 610             basename = value.str;
 611         }
 612 
 613         if (!strcmp(match, ".service")) {
 614             // Service is the "default" unit type, so strip it
 615             unit_name = strndup(basename, match - basename);
 616         } else {
 617             unit_name = strdup(basename);
 618         }
 619 
 620         nfiles++;
 621         units = g_list_prepend(units, unit_name);
 622     }
 623 
 624     dbus_message_unref(reply);
 625 
 626     crm_trace("Found %d manageable systemd unit files", nfiles);
 627     units = g_list_sort(units, sort_str);
 628     return units;
 629 }
 630 
 631 gboolean
 632 systemd_unit_exists(const char *name)
     /*  */
 633 {
 634     char *path = NULL;
 635     char *state = NULL;
 636 
 637     /* Note: Makes a blocking dbus calls
 638      * Used by resources_find_service_class() when resource class=service
 639      */
 640     if ((invoke_unit_by_name(name, NULL, &path) != pcmk_rc_ok)
 641         || (path == NULL)) {
 642         return FALSE;
 643     }
 644 
 645     /* A successful LoadUnit is not sufficient to determine the unit's
 646      * existence; it merely means the LoadUnit request received a reply.
 647      * We must make another blocking call to check the LoadState property.
 648      */
 649     state = systemd_get_property(path, "LoadState", NULL, NULL, NULL,
 650                                  DBUS_TIMEOUT_USE_DEFAULT);
 651     free(path);
 652     if (pcmk__str_any_of(state, "loaded", "masked", NULL)) {
 653         free(state);
 654         return TRUE;
 655     }
 656     free(state);
 657     return FALSE;
 658 }
 659 
 660 #define METADATA_FORMAT                                                     \
 661     "<?xml version=\"1.0\"?>\n"                                             \
 662     "<!DOCTYPE resource-agent SYSTEM \"ra-api-1.dtd\">\n"                   \
 663     "<resource-agent name=\"%s\" version=\"" PCMK_DEFAULT_AGENT_VERSION "\">\n" \
 664     "  <version>1.1</version>\n"                                            \
 665     "  <longdesc lang=\"en\">\n"                                            \
 666     "    %s\n"                                                              \
 667     "  </longdesc>\n"                                                       \
 668     "  <shortdesc lang=\"en\">systemd unit file for %s</shortdesc>\n"       \
 669     "  <parameters/>\n"                                                     \
 670     "  <actions>\n"                                                         \
 671     "    <action name=\"start\"     timeout=\"100\" />\n"                   \
 672     "    <action name=\"stop\"      timeout=\"100\" />\n"                   \
 673     "    <action name=\"status\"    timeout=\"100\" />\n"                   \
 674     "    <action name=\"monitor\"   timeout=\"100\" interval=\"60\"/>\n"    \
 675     "    <action name=\"meta-data\" timeout=\"5\"   />\n"                   \
 676     "  </actions>\n"                                                        \
 677     "  <special tag=\"systemd\"/>\n"                                        \
 678     "</resource-agent>\n"
 679 
 680 static char *
 681 systemd_unit_metadata(const char *name, int timeout)
     /*  */
 682 {
 683     char *meta = NULL;
 684     char *desc = NULL;
 685     char *path = NULL;
 686 
 687     char *escaped = NULL;
 688 
 689     if (invoke_unit_by_name(name, NULL, &path) == pcmk_rc_ok) {
 690         /* TODO: Worth a making blocking call for? Probably not. Possibly if cached. */
 691         desc = systemd_get_property(path, "Description", NULL, NULL, NULL,
 692                                     timeout);
 693     } else {
 694         desc = crm_strdup_printf("Systemd unit file for %s", name);
 695     }
 696 
 697     escaped = crm_xml_escape(desc);
 698 
 699     meta = crm_strdup_printf(METADATA_FORMAT, name, escaped, name);
 700     free(desc);
 701     free(path);
 702     free(escaped);
 703     return meta;
 704 }
 705 
 706 /*!
 707  * \internal
 708  * \brief Determine result of method from reply
 709  *
 710  * \param[in] reply  Reply to start, stop, or restart request
 711  * \param[in] op     Action that was executed
 712  */
 713 static void
 714 process_unit_method_reply(DBusMessage *reply, svc_action_t *op)
     /*  */
 715 {
 716     DBusError error;
 717 
 718     /* The first use of error here is not used other than as a non-NULL flag to
 719      * indicate that a request was indeed sent
 720      */
 721     if (pcmk_dbus_find_error((void *) &error, reply, &error)) {
 722         set_result_from_method_error(op, &error);
 723         dbus_error_free(&error);
 724 
 725     } else if (!pcmk_dbus_type_check(reply, NULL, DBUS_TYPE_OBJECT_PATH,
 726                                      __func__, __LINE__)) {
 727         crm_info("DBus request for %s of %s succeeded but "
 728                  "return type was unexpected", op->action, crm_str(op->rsc));
 729         services__set_result(op, PCMK_OCF_OK, PCMK_EXEC_DONE,
 730                              "systemd DBus method had unexpected reply");
 731 
 732     } else {
 733         const char *path = NULL;
 734 
 735         dbus_message_get_args(reply, NULL,
 736                               DBUS_TYPE_OBJECT_PATH, &path,
 737                               DBUS_TYPE_INVALID);
 738         crm_debug("DBus request for %s of %s using %s succeeded",
 739                   op->action, crm_str(op->rsc), path);
 740         services__set_result(op, PCMK_OCF_OK, PCMK_EXEC_DONE, NULL);
 741     }
 742 }
 743 
 744 /*!
 745  * \internal
 746  * \brief Process the completion of an asynchronous unit start, stop, or restart
 747  *
 748  * \param[in] pending    If not NULL, DBus call associated with request
 749  * \param[in] user_data  Action that was executed
 750  */
 751 static void
 752 unit_method_complete(DBusPendingCall *pending, void *user_data)
     /*  */
 753 {
 754     DBusMessage *reply = NULL;
 755     svc_action_t *op = user_data;
 756 
 757     crm_trace("Result for %s arrived", op->id);
 758 
 759     // Grab the reply
 760     if (pending != NULL) {
 761         reply = dbus_pending_call_steal_reply(pending);
 762     }
 763 
 764     // The call is no longer pending
 765     CRM_LOG_ASSERT(pending == op->opaque->pending);
 766     services_set_op_pending(op, NULL);
 767 
 768     // Determine result and finalize action
 769     process_unit_method_reply(reply, op);
 770     services__finalize_async_op(op);
 771     if (reply != NULL) {
 772         dbus_message_unref(reply);
 773     }
 774 }
 775 
 776 #define SYSTEMD_OVERRIDE_ROOT "/run/systemd/system/"
 777 
 778 /* When the cluster manages a systemd resource, we create a unit file override
 779  * to order the service "before" pacemaker. The "before" relationship won't
 780  * actually be used, since systemd won't ever start the resource -- we're
 781  * interested in the reverse shutdown ordering it creates, to ensure that
 782  * systemd doesn't stop the resource at shutdown while pacemaker is still
 783  * running.
 784  *
 785  * @TODO Add start timeout
 786  */
 787 #define SYSTEMD_OVERRIDE_TEMPLATE                           \
 788     "[Unit]\n"                                              \
 789     "Description=Cluster Controlled %s\n"                   \
 790     "Before=pacemaker.service pacemaker_remote.service\n"   \
 791     "\n"                                                    \
 792     "[Service]\n"                                           \
 793     "Restart=no\n"
 794 
 795 // Temporarily use rwxr-xr-x umask when opening a file for writing
 796 static FILE *
 797 create_world_readable(const char *filename)
     /*  */
 798 {
 799     mode_t orig_umask = umask(S_IWGRP | S_IWOTH);
 800     FILE *fp = fopen(filename, "w");
 801 
 802     umask(orig_umask);
 803     return fp;
 804 }
 805 
 806 static void
 807 create_override_dir(const char *agent)
     /*  */
 808 {
 809     char *override_dir = crm_strdup_printf(SYSTEMD_OVERRIDE_ROOT
 810                                            "/%s.service.d", agent);
 811     int rc = pcmk__build_path(override_dir, 0755);
 812 
 813     if (rc != pcmk_rc_ok) {
 814         crm_warn("Could not create systemd override directory %s: %s",
 815                  override_dir, pcmk_rc_str(rc));
 816     }
 817     free(override_dir);
 818 }
 819 
 820 static char *
 821 get_override_filename(const char *agent)
     /*  */
 822 {
 823     return crm_strdup_printf(SYSTEMD_OVERRIDE_ROOT
 824                              "/%s.service.d/50-pacemaker.conf", agent);
 825 }
 826 
 827 static void
 828 systemd_create_override(const char *agent, int timeout)
     /*  */
 829 {
 830     FILE *file_strm = NULL;
 831     char *override_file = get_override_filename(agent);
 832 
 833     create_override_dir(agent);
 834 
 835     /* Ensure the override file is world-readable. This is not strictly
 836      * necessary, but it avoids a systemd warning in the logs.
 837      */
 838     file_strm = create_world_readable(override_file);
 839     if (file_strm == NULL) {
 840         crm_err("Cannot open systemd override file %s for writing",
 841                 override_file);
 842     } else {
 843         char *override = crm_strdup_printf(SYSTEMD_OVERRIDE_TEMPLATE, agent);
 844 
 845         int rc = fprintf(file_strm, "%s\n", override);
 846 
 847         free(override);
 848         if (rc < 0) {
 849             crm_perror(LOG_WARNING, "Cannot write to systemd override file %s",
 850                        override_file);
 851         }
 852         fflush(file_strm);
 853         fclose(file_strm);
 854         systemd_daemon_reload(timeout);
 855     }
 856 
 857     free(override_file);
 858 }
 859 
 860 static void
 861 systemd_remove_override(const char *agent, int timeout)
     /*  */
 862 {
 863     char *override_file = get_override_filename(agent);
 864     int rc = unlink(override_file);
 865 
 866     if (rc < 0) {
 867         // Stop may be called when already stopped, which is fine
 868         crm_perror(LOG_DEBUG, "Cannot remove systemd override file %s",
 869                    override_file);
 870     } else {
 871         systemd_daemon_reload(timeout);
 872     }
 873     free(override_file);
 874 }
 875 
 876 /*!
 877  * \internal
 878  * \brief Parse result of systemd status check
 879  *
 880  * Set a status action's exit status and execution status based on a DBus
 881  * property check result, and finalize the action if asynchronous.
 882  *
 883  * \param[in] name      DBus interface name for property that was checked
 884  * \param[in] state     Property value
 885  * \param[in] userdata  Status action that check was done for
 886  */
 887 static void
 888 parse_status_result(const char *name, const char *state, void *userdata)
     /*  */
 889 {
 890     svc_action_t *op = userdata;
 891 
 892     crm_trace("Resource %s has %s='%s'",
 893               crm_str(op->rsc), name, crm_str(state));
 894 
 895     if (pcmk__str_eq(state, "active", pcmk__str_none)) {
 896         services__set_result(op, PCMK_OCF_OK, PCMK_EXEC_DONE, NULL);
 897 
 898     } else if (pcmk__str_eq(state, "reloading", pcmk__str_none)) {
 899         services__set_result(op, PCMK_OCF_OK, PCMK_EXEC_DONE, NULL);
 900 
 901     } else if (pcmk__str_eq(state, "activating", pcmk__str_none)) {
 902         services__set_result(op, PCMK_OCF_UNKNOWN, PCMK_EXEC_PENDING, NULL);
 903 
 904     } else if (pcmk__str_eq(state, "deactivating", pcmk__str_none)) {
 905         services__set_result(op, PCMK_OCF_UNKNOWN, PCMK_EXEC_PENDING, NULL);
 906 
 907     } else {
 908         services__set_result(op, PCMK_OCF_NOT_RUNNING, PCMK_EXEC_DONE, state);
 909     }
 910 
 911     if (!(op->synchronous)) {
 912         services_set_op_pending(op, NULL);
 913         services__finalize_async_op(op);
 914     }
 915 }
 916 
 917 /*!
 918  * \internal
 919  * \brief Invoke a systemd unit, given its DBus object path
 920  *
 921  * \param[in] op    Action to execute
 922  * \param[in] unit  DBus object path of systemd unit to invoke
 923  */
 924 static void
 925 invoke_unit_by_path(svc_action_t *op, const char *unit)
     /*  */
 926 {
 927     const char *method = NULL;
 928     DBusMessage *msg = NULL;
 929     DBusMessage *reply = NULL;
 930 
 931     if (pcmk__str_any_of(op->action, "monitor", "status", NULL)) {
 932         DBusPendingCall *pending = NULL;
 933         char *state;
 934 
 935         state = systemd_get_property(unit, "ActiveState",
 936                                      (op->synchronous? NULL : parse_status_result),
 937                                      op, (op->synchronous? NULL : &pending),
 938                                      op->timeout);
 939         if (op->synchronous) {
 940             parse_status_result("ActiveState", state, op);
 941             free(state);
 942 
 943         } else if (pending == NULL) { // Could not get ActiveState property
 944             services__format_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
 945                                     "Could not get state for unit %s from DBus",
 946                                     op->agent);
 947             services__finalize_async_op(op);
 948 
 949         } else {
 950             services_set_op_pending(op, pending);
 951         }
 952         return;
 953 
 954     } else if (pcmk__str_eq(op->action, "start", pcmk__str_none)) {
 955         method = "StartUnit";
 956         systemd_create_override(op->agent, op->timeout);
 957 
 958     } else if (pcmk__str_eq(op->action, "stop", pcmk__str_none)) {
 959         method = "StopUnit";
 960         systemd_remove_override(op->agent, op->timeout);
 961 
 962     } else if (pcmk__str_eq(op->action, "restart", pcmk__str_none)) {
 963         method = "RestartUnit";
 964 
 965     } else {
 966         services__format_result(op, PCMK_OCF_UNIMPLEMENT_FEATURE,
 967                                 PCMK_EXEC_ERROR,
 968                                 "Action %s not implemented "
 969                                 "for systemd resources", crm_str(op->action));
 970         if (!(op->synchronous)) {
 971             services__finalize_async_op(op);
 972         }
 973         return;
 974     }
 975 
 976     crm_trace("Calling %s for unit path %s named %s",
 977               method, unit, crm_str(op->rsc));
 978 
 979     msg = systemd_new_method(method);
 980     CRM_ASSERT(msg != NULL);
 981 
 982     /* (ss) */
 983     {
 984         const char *replace_s = "replace";
 985         char *name = systemd_service_name(op->agent, pcmk__str_eq(op->action, "meta-data", pcmk__str_none));
 986 
 987         CRM_LOG_ASSERT(dbus_message_append_args(msg, DBUS_TYPE_STRING, &name, DBUS_TYPE_INVALID));
 988         CRM_LOG_ASSERT(dbus_message_append_args(msg, DBUS_TYPE_STRING, &replace_s, DBUS_TYPE_INVALID));
 989 
 990         free(name);
 991     }
 992 
 993     if (op->synchronous) {
 994         reply = systemd_send_recv(msg, NULL, op->timeout);
 995         dbus_message_unref(msg);
 996         process_unit_method_reply(reply, op);
 997         if (reply != NULL) {
 998             dbus_message_unref(reply);
 999         }
1000 
1001     } else {
1002         DBusPendingCall *pending = systemd_send(msg, unit_method_complete, op,
1003                                                 op->timeout);
1004 
1005         dbus_message_unref(msg);
1006         if (pending == NULL) {
1007             services__set_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
1008                                  "Unable to send DBus message");
1009             services__finalize_async_op(op);
1010 
1011         } else {
1012             services_set_op_pending(op, pending);
1013         }
1014     }
1015 }
1016 
1017 static gboolean
1018 systemd_timeout_callback(gpointer p)
     /*  */
1019 {
1020     svc_action_t * op = p;
1021 
1022     op->opaque->timerid = 0;
1023     crm_info("%s action for systemd unit %s named '%s' timed out",
1024              op->action, op->agent, op->rsc);
1025     services__format_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_TIMEOUT,
1026                             "%s action for systemd unit %s "
1027                             "did not complete in time", op->action, op->agent);
1028     services__finalize_async_op(op);
1029     return FALSE;
1030 }
1031 
1032 /*!
1033  * \internal
1034  * \brief Execute a systemd action
1035  *
1036  * \param[in] op  Action to execute
1037  *
1038  * \return Standard Pacemaker return code
1039  * \retval EBUSY          Recurring operation could not be initiated
1040  * \retval pcmk_rc_error  Synchronous action failed
1041  * \retval pcmk_rc_ok     Synchronous action succeeded, or asynchronous action
1042  *                        should not be freed (because it's pending or because
1043  *                        it failed to execute and was already freed)
1044  *
1045  * \note If the return value for an asynchronous action is not pcmk_rc_ok, the
1046  *       caller is responsible for freeing the action.
1047  */
1048 int
1049 services__execute_systemd(svc_action_t *op)
     /*  */
1050 {
1051     CRM_ASSERT(op != NULL);
1052 
1053     if ((op->action == NULL) || (op->agent == NULL)) {
1054         services__set_result(op, PCMK_OCF_NOT_CONFIGURED, PCMK_EXEC_ERROR_FATAL,
1055                              "Bug in action caller");
1056         goto done;
1057     }
1058 
1059     if (!systemd_init()) {
1060         services__set_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
1061                              "No DBus connection");
1062         goto done;
1063     }
1064 
1065     crm_debug("Performing %ssynchronous %s op on systemd unit %s named '%s'",
1066               (op->synchronous? "" : "a"), op->action, op->agent,
1067               crm_str(op->rsc));
1068 
1069     if (pcmk__str_eq(op->action, "meta-data", pcmk__str_casei)) {
1070         op->stdout_data = systemd_unit_metadata(op->agent, op->timeout);
1071         services__set_result(op, PCMK_OCF_OK, PCMK_EXEC_DONE, NULL);
1072         goto done;
1073     }
1074 
1075     /* invoke_unit_by_name() should always override these values, which are here
1076      * just as a fail-safe in case there are any code paths that neglect to
1077      */
1078     services__set_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
1079                          "Bug in service library");
1080 
1081     if (invoke_unit_by_name(op->agent, op, NULL) == pcmk_rc_ok) {
1082         op->opaque->timerid = g_timeout_add(op->timeout + 5000,
1083                                             systemd_timeout_callback, op);
1084         services_add_inflight_op(op);
1085         return pcmk_rc_ok;
1086     }
1087 
1088 done:
1089     if (op->synchronous) {
1090         return (op->rc == PCMK_OCF_OK)? pcmk_rc_ok : pcmk_rc_error;
1091     } else {
1092         return services__finalize_async_op(op);
1093     }
1094 }
/* */
root/lib/services/systemd.c

DEFINITIONS
