/*
	 * Copyright 2010-2026 the Pacemaker project contributors
	 *
	 * The version control history for this file may have further details.
	 *
	 * This source code is licensed under the GNU Lesser General Public License
	 * version 2.1 or later (LGPLv2.1+) WITHOUT ANY WARRANTY.
	 */
	
	#include <crm_internal.h>
	
	#include <stdbool.h>                    // bool, true, false
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/wait.h>
	#include <errno.h>
	#include <unistd.h>
	#include <dirent.h>
	#include <grp.h>
	#include <string.h>
	#include <sys/time.h>
	#include <sys/resource.h>
	
	#include "crm/crm.h"
	#include "crm/common/mainloop.h"
	#include "crm/services.h"
	#include "crm/services_internal.h"
	
	#include "services_private.h"
	
	static const char *filter_dir = NULL;
	
	static void close_pipe(int fildes[]);
	
	/* We have two alternative ways of handling SIGCHLD when synchronously waiting
	 * for spawned processes to complete. Both rely on polling a file descriptor to
	 * discover SIGCHLD events.
	 *
	 * If sys/signalfd.h is available (e.g. on Linux), we call signalfd() to
	 * generate the file descriptor. Otherwise, we use the "self-pipe trick"
	 * (opening a pipe and writing a byte to it when SIGCHLD is received).
	 */
	#ifdef HAVE_SYS_SIGNALFD_H
	
	// signalfd() implementation
	
	#include <sys/signalfd.h>
	
	// Everything needed to manage SIGCHLD handling
	struct sigchld_data_s {
	    sigset_t mask;      // Signals to block now (including SIGCHLD)
	    sigset_t old_mask;  // Previous set of blocked signals
	    bool ignored;       // If SIGCHLD for another child has been ignored
	};
	
	// Initialize SIGCHLD data and prepare for use
	static bool
	sigchld_setup(struct sigchld_data_s *data)
	{
	    sigemptyset(&(data->mask));
	    sigaddset(&(data->mask), SIGCHLD);
	
	    sigemptyset(&(data->old_mask));
	
	    // Block SIGCHLD (saving previous set of blocked signals to restore later)
	    if (sigprocmask(SIG_BLOCK, &(data->mask), &(data->old_mask)) < 0) {
	        pcmk__info("Wait for child process completion failed: %s "
	                   QB_XS " source=sigprocmask",
	                   pcmk_rc_str(errno));
	        return false;
	    }
	
	    data->ignored = false;
	
	    return true;
	}
	
	// Get a file descriptor suitable for polling for SIGCHLD events
	static int
	sigchld_open(struct sigchld_data_s *data)
	{
	    int fd;
	
	    CRM_CHECK(data != NULL, return -1);
	
	    fd = signalfd(-1, &(data->mask), SFD_NONBLOCK);
	    if (fd < 0) {
	        pcmk__info("Wait for child process completion failed: %s "
	                   QB_XS " source=signalfd",
	                   pcmk_rc_str(errno));
	    }
	    return fd;
	}
	
	// Close a file descriptor returned by sigchld_open()
	static void
	sigchld_close(int fd)
	{
	    if (fd > 0) {
	        close(fd);
	    }
	}
	
	// Return true if SIGCHLD was received from polled fd
	static bool
	sigchld_received(int fd, int pid, struct sigchld_data_s *data)
	{
	    struct signalfd_siginfo fdsi;
	    ssize_t s;
	
	    if (fd < 0) {
	        return false;
	    }
	    s = read(fd, &fdsi, sizeof(struct signalfd_siginfo));
	    if (s != sizeof(struct signalfd_siginfo)) {
	        pcmk__info("Wait for child process completion failed: %s "
	                   QB_XS " source=read",
	                   pcmk_rc_str(errno));
	
	    } else if (fdsi.ssi_signo == SIGCHLD) {
	        if (fdsi.ssi_pid == pid) {
	            return true;
	
	        } else {
	            /* This SIGCHLD is for another child. We have to ignore it here but
	             * will still need to resend it after this synchronous action has
	             * completed and SIGCHLD has been restored to be handled by the
	             * previous SIGCHLD handler, so that it will be handled.
	             */
	            data->ignored = true;
	            return false;
	        }
	    }
	    return false;
	}
	
	// Do anything needed after done waiting for SIGCHLD
	static void
	sigchld_cleanup(struct sigchld_data_s *data)
	{
	    // Restore the original set of blocked signals
	    if ((sigismember(&(data->old_mask), SIGCHLD) == 0)
	        && (sigprocmask(SIG_UNBLOCK, &(data->mask), NULL) < 0)) {
	        pcmk__warn("Could not clean up after child process completion: %s",
	                   pcmk_rc_str(errno));
	    }
	
	    // Resend any ignored SIGCHLD for other children so that they'll be handled.
	    if (data->ignored && kill(getpid(), SIGCHLD) != 0) {
	        pcmk__warn("Could not resend ignored SIGCHLD to ourselves: %s",
	                   pcmk_rc_str(errno));
	    }
	}
	
	#else // HAVE_SYS_SIGNALFD_H not defined
	
	// Self-pipe implementation (see above for function descriptions)
	
	struct sigchld_data_s {
	    int pipe_fd[2];             // Pipe file descriptors
	    struct sigaction sa;        // Signal handling info (with SIGCHLD)
	    struct sigaction old_sa;    // Previous signal handling info
	    bool ignored;               // If SIGCHLD for another child has been ignored
	};
	
	// We need a global to use in the signal handler
	volatile struct sigchld_data_s *last_sigchld_data = NULL;
	
	static void
	sigchld_handler(void)
	{
	    // We received a SIGCHLD, so trigger pipe polling
	    if ((last_sigchld_data != NULL)
	        && (last_sigchld_data->pipe_fd[1] >= 0)
	        && (write(last_sigchld_data->pipe_fd[1], "", 1) == -1)) {
	        pcmk__info("Wait for child process completion failed: %s "
	                   QB_XS " source=write",
	                   pcmk_rc_str(errno));
	    }
	}
	
	static bool
	sigchld_setup(struct sigchld_data_s *data)
	{
	    int rc;
	
	    data->pipe_fd[0] = data->pipe_fd[1] = -1;
	
	    if (pipe(data->pipe_fd) == -1) {
	        pcmk__info("Wait for child process completion failed: %s "
	                   QB_XS " source=pipe",
	                   pcmk_rc_str(errno));
	        return false;
	    }
	
	    rc = pcmk__set_nonblocking(data->pipe_fd[0]);
	    if (rc != pcmk_rc_ok) {
	        pcmk__info("Could not set pipe input non-blocking: %s " QB_XS " rc=%d",
	                   pcmk_rc_str(rc), rc);
	    }
	    rc = pcmk__set_nonblocking(data->pipe_fd[1]);
	    if (rc != pcmk_rc_ok) {
	        pcmk__info("Could not set pipe output non-blocking: %s " QB_XS " rc=%d",
	                   pcmk_rc_str(rc), rc);
	    }
	
	    // Set SIGCHLD handler
	    data->sa.sa_handler = (sighandler_t) sigchld_handler;
	    data->sa.sa_flags = 0;
	    sigemptyset(&(data->sa.sa_mask));
	    if (sigaction(SIGCHLD, &(data->sa), &(data->old_sa)) < 0) {
	        pcmk__info("Wait for child process completion failed: %s "
	                   QB_XS " source=sigaction",
	                   pcmk_rc_str(errno));
	    }
	
	    data->ignored = false;
	
	    // Remember data for use in signal handler
	    last_sigchld_data = data;
	    return true;
	}
	
	static int
	sigchld_open(struct sigchld_data_s *data)
	{
	    CRM_CHECK(data != NULL, return -1);
	    return data->pipe_fd[0];
	}
	
	static void
	sigchld_close(int fd)
	{
	    // Pipe will be closed in sigchld_cleanup()
	}
	
	static bool
	sigchld_received(int fd, int pid, struct sigchld_data_s *data)
	{
	    char ch;
	
	    if (fd < 0) {
	        return false;
	    }
	
	    // Clear out the self-pipe
	    while (read(fd, &ch, 1) == 1) /*omit*/;
	    return true;
	}
	
	static void
	sigchld_cleanup(struct sigchld_data_s *data)
	{
	    // Restore the previous SIGCHLD handler
	    if (sigaction(SIGCHLD, &(data->old_sa), NULL) < 0) {
	        pcmk__warn("Could not clean up after child process completion: %s",
	                   pcmk_rc_str(errno));
	    }
	
	    close_pipe(data->pipe_fd);
	
	    // Resend any ignored SIGCHLD for other children so that they'll be handled.
	    if (data->ignored && kill(getpid(), SIGCHLD) != 0) {
	        pcmk__warn("Could not resend ignored SIGCHLD to ourselves: %s",
	                   pcmk_rc_str(errno));
	    }
	}
	
	#endif
	
	/*!
	 * \internal
	 * \brief Close the two file descriptors of a pipe
	 *
	 * \param[in,out] fildes  Array of file descriptors opened by pipe()
	 */
	static void
	close_pipe(int fildes[])
	{
	    if (fildes[0] >= 0) {
	        close(fildes[0]);
	        fildes[0] = -1;
	    }
	    if (fildes[1] >= 0) {
	        close(fildes[1]);
	        fildes[1] = -1;
	    }
	}
	
	#define out_type(is_stderr) ((is_stderr)? "stderr" : "stdout")
	
	// Maximum number of bytes of stdout or stderr we'll accept
	#define MAX_OUTPUT (10 * 1024 * 1024)
	
	static gboolean
	svc_read_output(int fd, svc_action_t * op, bool is_stderr)
	{
	    char *data = NULL;
	    ssize_t rc = 0;
	    size_t len = 0;
	    size_t discarded = 0;
	    char buf[500];
	    static const size_t buf_read_len = sizeof(buf) - 1;
	
	    if (fd < 0) {
	        pcmk__trace("No fd for %s", op->id);
	        return FALSE;
	    }
	
	    if (is_stderr && op->stderr_data) {
	        len = strlen(op->stderr_data);
	        data = op->stderr_data;
	        pcmk__trace("Reading %s stderr into offset %zu", op->id, len);
	
	    } else if (is_stderr == FALSE && op->stdout_data) {
	        len = strlen(op->stdout_data);
	        data = op->stdout_data;
	        pcmk__trace("Reading %s stdout into offset %zu", op->id, len);
	
	    } else {
	        pcmk__trace("Reading %s %s", op->id, out_type(is_stderr));
	    }
	
	    do {
	        errno = 0;
	        rc = read(fd, buf, buf_read_len);
	        if (rc > 0) {
	            if (len < MAX_OUTPUT) {
	                buf[rc] = 0;
	                pcmk__trace("Received %zd bytes of %s %s: %.80s", rc, op->id,
	                            out_type(is_stderr), buf);
	                data = pcmk__realloc(data, len + rc + 1);
	                strcpy(data + len, buf);
	                len += rc;
	            } else {
	                discarded += rc;
	            }
	
	        } else if (errno != EINTR) { // Fatal error or EOF
	            rc = 0;
	            break;
	        }
	    } while ((rc == buf_read_len) || (rc < 0));
	
	    if (discarded > 0) {
	        pcmk__warn("Truncated %s %s to %zu bytes (discarded %zu)", op->id,
	                   out_type(is_stderr), len, discarded);
	    }
	
	    if (is_stderr) {
	        op->stderr_data = data;
	    } else {
	        op->stdout_data = data;
	    }
	
	    return rc != 0;
	}
	
	static int
	dispatch_stdout(gpointer userdata)
	{
	    svc_action_t *op = (svc_action_t *) userdata;
	
	    return svc_read_output(op->opaque->stdout_fd, op, FALSE);
	}
	
	static int
	dispatch_stderr(gpointer userdata)
	{
	    svc_action_t *op = (svc_action_t *) userdata;
	
	    return svc_read_output(op->opaque->stderr_fd, op, TRUE);
	}
	
	static void
	pipe_out_done(gpointer user_data)
	{
	    svc_action_t *op = (svc_action_t *) user_data;
	
	    pcmk__trace("%p", op);
	
	    op->opaque->stdout_gsource = NULL;
	    if (op->opaque->stdout_fd > STDOUT_FILENO) {
	        close(op->opaque->stdout_fd);
	    }
	    op->opaque->stdout_fd = -1;
	}
	
	static void
	pipe_err_done(gpointer user_data)
	{
	    svc_action_t *op = (svc_action_t *) user_data;
	
	    op->opaque->stderr_gsource = NULL;
	    if (op->opaque->stderr_fd > STDERR_FILENO) {
	        close(op->opaque->stderr_fd);
	    }
	    op->opaque->stderr_fd = -1;
	}
	
	static struct mainloop_fd_callbacks stdout_callbacks = {
	    .dispatch = dispatch_stdout,
	    .destroy = pipe_out_done,
	};
	
	static struct mainloop_fd_callbacks stderr_callbacks = {
	    .dispatch = dispatch_stderr,
	    .destroy = pipe_err_done,
	};
	
	static void
	set_ocf_env(const char *key, const char *value, gpointer user_data)
	{
	    // @FIXME @COMPAT This seems like it should be a fatal error
	    if (setenv(key, value, 1) != 0) {
	        int rc = errno;
	
	        pcmk__err("setenv failed for key='%s' and value='%s': %s",
	                  pcmk__s(key, ""), pcmk__s(value, ""), strerror(rc));
	    }
	}
	
	static void
	set_ocf_env_with_prefix(gpointer key, gpointer value, gpointer user_data)
	{
	    const char *ckey = key;
	
	    if (pcmk__str_eq(ckey, "OCF_CHECK_LEVEL", pcmk__str_none)) {
	        set_ocf_env(ckey, value, user_data);
	
	    } else {
	        char *buffer = pcmk__assert_asprintf("OCF_RESKEY_%s", ckey);
	
	        set_ocf_env(buffer, value, user_data);
	        free(buffer);
	    }
	}
	
	static void
	set_alert_env(gpointer key, gpointer value, gpointer user_data)
	{
	    int rc;
	
	    if (value != NULL) {
	        rc = setenv(key, value, 1);
	    } else {
	        rc = unsetenv(key);
	    }
	
	    if (rc < 0) {
	        // @FIXME @COMPAT This seems like it should be a fatal error
	        rc = errno;
	
	        if (value != NULL) {
	            pcmk__err("setenv %s='%s' failed: %s", (const char *) key,
	                      (const char *) value, strerror(rc));
	        } else {
	            pcmk__err("unsetenv %s failed: %s", (const char *) key,
	                      strerror(rc));
	        }
	
	    } else {
	        if (value != NULL) {
	            pcmk__trace("setenv %s='%s'", (const char *) key,
	                        (const char *) value);
	        } else {
	            pcmk__trace("unsetenv %s", (const char *) key);
	        }
	    }
	}
	
	/*!
	 * \internal
	 * \brief Add environment variables suitable for an action
	 *
	 * \param[in] op  Action to use
	 */
	static void
	add_action_env_vars(const svc_action_t *op)
	{
	    void (*env_setter)(gpointer, gpointer, gpointer) = NULL;
	    if (op->agent == NULL) {
	        env_setter = set_alert_env;  /* we deal with alert handler */
	
	    } else if (pcmk__str_eq(op->standard, PCMK_RESOURCE_CLASS_OCF, pcmk__str_casei)) {
	        env_setter = set_ocf_env_with_prefix;
	    }
	
	    if (env_setter != NULL && op->params != NULL) {
	        g_hash_table_foreach(op->params, env_setter, NULL);
	    }
	
	    if (env_setter == NULL || env_setter == set_alert_env) {
	        return;
	    }
	
	    set_ocf_env("OCF_RA_VERSION_MAJOR", PCMK_OCF_MAJOR_VERSION, NULL);
	    set_ocf_env("OCF_RA_VERSION_MINOR", PCMK_OCF_MINOR_VERSION, NULL);
	    set_ocf_env("OCF_ROOT", PCMK_OCF_ROOT, NULL);
	    set_ocf_env("OCF_EXIT_REASON_PREFIX", PCMK_OCF_REASON_PREFIX, NULL);
	
	    if (op->rsc) {
	        set_ocf_env("OCF_RESOURCE_INSTANCE", op->rsc, NULL);
	    }
	
	    if (op->agent != NULL) {
	        set_ocf_env("OCF_RESOURCE_TYPE", op->agent, NULL);
	    }
	
	    /* Notes: this is not added to specification yet. Sept 10,2004 */
	    if (op->provider != NULL) {
	        set_ocf_env("OCF_RESOURCE_PROVIDER", op->provider, NULL);
	    }
	}
	
	static void
	pipe_in_single_parameter(gpointer key, gpointer value, gpointer user_data)
	{
	    svc_action_t *op = user_data;
	    char *buffer = pcmk__assert_asprintf("%s=%s\n", (const char *) key,
	                                         (const char *) value);
	    size_t len = strlen(buffer);
	    size_t total = 0;
	    ssize_t ret = 0;
	
	    do {
	        errno = 0;
	        ret = write(op->opaque->stdin_fd, buffer + total, len - total);
	        if (ret > 0) {
	            total += ret;
	        }
	    } while ((errno == EINTR) && (total < len));
	    free(buffer);
	}
	
	/*!
	 * \internal
	 * \brief Pipe parameters in via stdin for action
	 *
	 * \param[in] op  Action to use
	 */
	static void
	pipe_in_action_stdin_parameters(const svc_action_t *op)
	{
	    if (op->params) {
	        g_hash_table_foreach(op->params, pipe_in_single_parameter, (gpointer) op);
	    }
	}
	
	gboolean
	recurring_action_timer(gpointer data)
	{
	    svc_action_t *op = data;
	

	    pcmk__debug("Scheduling another invocation of %s", op->id);
	
	    /* Clean out the old result */

	    g_clear_pointer(&op->stdout_data, free);

	    g_clear_pointer(&op->stderr_data, free);
	    op->opaque->repeat_timer = 0;
	
	    services_action_async(op, NULL);
	    return FALSE;
	}
	
	/*!
	 * \internal
	 * \brief Finalize handling of an asynchronous operation
	 *
	 * Given a completed asynchronous operation, cancel or reschedule it as
	 * appropriate if recurring, call its callback if registered, stop tracking it,
	 * and clean it up.
	 *
	 * \param[in,out] op  Operation to finalize
	 *
	 * \return Standard Pacemaker return code
	 * \retval EINVAL      Caller supplied NULL or invalid \p op
	 * \retval EBUSY       Uncanceled recurring action has only been cleaned up
	 * \retval pcmk_rc_ok  Action has been freed
	 *
	 * \note If the return value is not pcmk_rc_ok, the caller is responsible for
	 *       freeing the action.
	 */
	int
	services__finalize_async_op(svc_action_t *op)
	{
	    CRM_CHECK((op != NULL) && !(op->synchronous), return EINVAL);
	
	    if (op->interval_ms != 0) {
	        // Recurring operations must be either cancelled or rescheduled
	        if (op->cancel) {
	            services__set_cancelled(op);
	            cancel_recurring_action(op);
	        } else {
	            op->opaque->repeat_timer = pcmk__create_timer(op->interval_ms,
	                                                          recurring_action_timer,
	                                                          op);
	        }
	    }
	
	    if (op->opaque->callback != NULL) {
	        op->opaque->callback(op);
	    }
	
	    // Stop tracking the operation (as in-flight or blocked)
	    op->pid = 0;
	    services_untrack_op(op);
	
	    if ((op->interval_ms != 0) && !(op->cancel)) {
	        // Do not free recurring actions (they will get freed when cancelled)
	        services_action_cleanup(op);
	        return EBUSY;
	    }
	
	    services_action_free(op);
	    return pcmk_rc_ok;
	}
	
	static void
	close_op_input(svc_action_t *op)
	{
	    if (op->opaque->stdin_fd >= 0) {
	        close(op->opaque->stdin_fd);
	    }
	}
	
	static void
	finish_op_output(svc_action_t *op, bool is_stderr)
	{
	    mainloop_io_t **source;
	    int fd;
	
	    if (is_stderr) {
	        source = &(op->opaque->stderr_gsource);
	        fd = op->opaque->stderr_fd;
	    } else {
	        source = &(op->opaque->stdout_gsource);
	        fd = op->opaque->stdout_fd;
	    }
	
	    if (op->synchronous || *source) {
	        pcmk__trace("Finish reading %s[%d] %s", op->id, op->pid,
	                    (is_stderr? "stderr" : "stdout"));
	        svc_read_output(fd, op, is_stderr);
	        if (op->synchronous) {
	            close(fd);
	        } else {
	            mainloop_del_fd(*source);
	            *source = NULL;
	        }
	    }
	}
	
	// Log an operation's stdout and stderr
	static void
	log_op_output(svc_action_t *op)
	{
	    char *prefix = pcmk__assert_asprintf("%s[%d] error output", op->id,
	                                         op->pid);
	
	    /* The library caller has better context to know how important the output
	     * is, so log it at info and debug severity here. They can log it again at
	     * higher severity if appropriate.
	     */
	    crm_log_output(LOG_INFO, prefix, op->stderr_data);
	    strcpy(prefix + strlen(prefix) - strlen("error output"), "output");
	    crm_log_output(LOG_DEBUG, prefix, op->stdout_data);
	    free(prefix);
	}
	
	static void
	parse_exit_reason_from_stderr(svc_action_t *op)
	{
	    const char *reason = NULL;
	
	    if ((op->stderr_data == NULL) ||
	        // Only OCF agents have exit reasons in stderr
	        !pcmk__str_eq(op->standard, PCMK_RESOURCE_CLASS_OCF, pcmk__str_none)) {
	        return;
	    }
	
	    // Find the last occurrence of the magic string indicating an exit reason
	    reason = g_strrstr(op->stderr_data, PCMK_OCF_REASON_PREFIX);
	
	    if (reason != NULL) {
	        // Skip over the magic string itself
	        reason += sizeof(PCMK_OCF_REASON_PREFIX) - 1;
	    }
	
	    if (pcmk__str_empty(reason) || (reason[0] == '\n')) {
	        // No exit reason or empty exit reason
	        return;
	    }
	
	    // Exit reason goes to end of line (or end of output)
	    free(op->opaque->exit_reason);
	    op->opaque->exit_reason = strndup(reason, strcspn(reason, "\n"));
	}
	
	/*!
	 * \internal
	 * \brief Process the completion of an asynchronous child process
	 *
	 * \param[in,out] p         Child process that completed
	 * \param[in]     core      (Unused)
	 * \param[in]     signo     Signal that interrupted child, if any
	 * \param[in]     exitcode  Exit status of child process
	 */
	static void
	async_action_complete(mainloop_child_t *p, int core, int signo, int exitcode)
	{
	    svc_action_t *op = mainloop_child_userdata(p);
	
	    mainloop_clear_child_userdata(p);
	    CRM_CHECK(op->pid == p->pid,
	              services__set_result(op, services__generic_error(op),
	                                   PCMK_EXEC_ERROR, "Bug in mainloop handling");
	              return);
	
	    /* Depending on the priority the mainloop gives the stdout and stderr
	     * file descriptors, this function could be called before everything has
	     * been read from them, so force a final read now.
	     */
	    finish_op_output(op, true);
	    finish_op_output(op, false);
	
	    close_op_input(op);
	
	    if (signo == 0) {
	        pcmk__debug("%s[%d] exited with status %d", op->id, op->pid, exitcode);
	        services__set_result(op, exitcode, PCMK_EXEC_DONE, NULL);
	        log_op_output(op);
	        parse_exit_reason_from_stderr(op);
	
	    } else if (mainloop_child_timeout(p)) {
	        const char *kind = services__action_kind(op);
	
	        pcmk__info("%s %s[%d] timed out after %s", kind, op->id, op->pid,
	                   pcmk__readable_interval(op->timeout));
	        services__format_result(op, services__generic_error(op),
	                                PCMK_EXEC_TIMEOUT,
	                                "%s did not complete within %s",
	                                kind, pcmk__readable_interval(op->timeout));
	
	    } else if (op->cancel) {
	        /* If an in-flight recurring operation was killed because it was
	         * cancelled, don't treat that as a failure.
	         */
	        pcmk__info("%s[%d] terminated with signal %d (%s)", op->id, op->pid,
	                   signo, strsignal(signo));
	        services__set_result(op, PCMK_OCF_OK, PCMK_EXEC_CANCELLED, NULL);
	
	    } else {
	        pcmk__info("%s[%d] terminated with signal %d (%s)", op->id, op->pid,
	                   signo, strsignal(signo));
	        services__format_result(op, PCMK_OCF_UNKNOWN_ERROR, PCMK_EXEC_ERROR,
	                                "%s interrupted by %s signal",
	                                services__action_kind(op), strsignal(signo));
	    }
	
	    services__finalize_async_op(op);
	}
	
	/*!
	 * \internal
	 * \brief Return agent standard's exit status for "generic error"
	 *
	 * When returning an internal error for an action, a value that is appropriate
	 * to the action's agent standard must be used. This function returns a value
	 * appropriate for errors in general.
	 *
	 * \param[in] op  Action that error is for
	 *
	 * \return Exit status appropriate to agent standard
	 * \note Actions without a standard will get PCMK_OCF_UNKNOWN_ERROR.
	 */
	int
	services__generic_error(const svc_action_t *op)
	{
	    if ((op == NULL) || (op->standard == NULL)) {
	        return PCMK_OCF_UNKNOWN_ERROR;
	    }
	
	#if PCMK__ENABLE_LSB
	    if (pcmk__str_eq(op->standard, PCMK_RESOURCE_CLASS_LSB, pcmk__str_casei)
	        && pcmk__str_eq(op->action, PCMK_ACTION_STATUS, pcmk__str_casei)) {
	
	        return PCMK_LSB_STATUS_UNKNOWN;
	    }
	#endif
	
	    return PCMK_OCF_UNKNOWN_ERROR;
	}
	
	/*!
	 * \internal
	 * \brief Return agent standard's exit status for "not installed"
	 *
	 * When returning an internal error for an action, a value that is appropriate
	 * to the action's agent standard must be used. This function returns a value
	 * appropriate for "not installed" errors.
	 *
	 * \param[in] op  Action that error is for
	 *
	 * \return Exit status appropriate to agent standard
	 * \note Actions without a standard will get PCMK_OCF_UNKNOWN_ERROR.
	 */
	int
	services__not_installed_error(const svc_action_t *op)
	{
	    if ((op == NULL) || (op->standard == NULL)) {
	        return PCMK_OCF_UNKNOWN_ERROR;
	    }
	
	#if PCMK__ENABLE_LSB
	    if (pcmk__str_eq(op->standard, PCMK_RESOURCE_CLASS_LSB, pcmk__str_casei)
	        && pcmk__str_eq(op->action, PCMK_ACTION_STATUS, pcmk__str_casei)) {
	
	        return PCMK_LSB_STATUS_NOT_INSTALLED;
	    }
	#endif
	
	    return PCMK_OCF_NOT_INSTALLED;
	}
	
	/*!
	 * \internal
	 * \brief Return agent standard's exit status for "insufficient privileges"
	 *
	 * When returning an internal error for an action, a value that is appropriate
	 * to the action's agent standard must be used. This function returns a value
	 * appropriate for "insufficient privileges" errors.
	 *
	 * \param[in] op  Action that error is for
	 *
	 * \return Exit status appropriate to agent standard
	 * \note Actions without a standard will get PCMK_OCF_UNKNOWN_ERROR.
	 */
	int
	services__authorization_error(const svc_action_t *op)
	{
	    if ((op == NULL) || (op->standard == NULL)) {
	        return PCMK_OCF_UNKNOWN_ERROR;
	    }
	
	#if PCMK__ENABLE_LSB
	    if (pcmk__str_eq(op->standard, PCMK_RESOURCE_CLASS_LSB, pcmk__str_casei)
	        && pcmk__str_eq(op->action, PCMK_ACTION_STATUS, pcmk__str_casei)) {
	
	        return PCMK_LSB_STATUS_INSUFFICIENT_PRIV;
	    }
	#endif
	
	    return PCMK_OCF_INSUFFICIENT_PRIV;
	}
	
	/*!
	 * \internal
	 * \brief Return agent standard's exit status for "not configured"
	 *
	 * When returning an internal error for an action, a value that is appropriate
	 * to the action's agent standard must be used. This function returns a value
	 * appropriate for "not configured" errors.
	 *
	 * \param[in] op        Action that error is for
	 * \param[in] is_fatal  Whether problem is cluster-wide instead of only local
	 *
	 * \return Exit status appropriate to agent standard
	 * \note Actions without a standard will get PCMK_OCF_UNKNOWN_ERROR.
	 */
	int
	services__configuration_error(const svc_action_t *op, bool is_fatal)
	{
	    if ((op == NULL) || (op->standard == NULL)) {
	        return PCMK_OCF_UNKNOWN_ERROR;
	    }
	
	#if PCMK__ENABLE_LSB
	    if (pcmk__str_eq(op->standard, PCMK_RESOURCE_CLASS_LSB, pcmk__str_casei)
	        && pcmk__str_eq(op->action, PCMK_ACTION_STATUS, pcmk__str_casei)) {
	
	        return PCMK_LSB_NOT_CONFIGURED;
	    }
	#endif
	
	    return is_fatal? PCMK_OCF_NOT_CONFIGURED : PCMK_OCF_INVALID_PARAM;
	}
	
	
	/*!
	 * \internal
	 * \brief Set operation rc and status per errno from stat(), fork() or execvp()
	 *
	 * \param[in,out] op     Operation to set rc and status for
	 * \param[in]     error  Value of errno after system call
	 *
	 * \return void
	 */
	void
	services__handle_exec_error(svc_action_t * op, int error)
	{
	    const char *name = op->opaque->exec;
	
	    if (name == NULL) {
	        name = op->agent;
	        if (name == NULL) {
	            name = op->id;
	        }
	    }
	
	    switch (error) {   /* see execve(2), stat(2) and fork(2) */
	        case ENOENT:   /* No such file or directory */
	        case EISDIR:   /* Is a directory */
	        case ENOTDIR:  /* Path component is not a directory */
	        case EINVAL:   /* Invalid executable format */
	        case ENOEXEC:  /* Invalid executable format */
	            services__format_result(op, services__not_installed_error(op),
	                                    PCMK_EXEC_NOT_INSTALLED, "%s: %s",
	                                    name, pcmk_rc_str(error));
	            break;
	        case EACCES:   /* permission denied (various errors) */
	        case EPERM:    /* permission denied (various errors) */
	            services__format_result(op, services__authorization_error(op),
	                                    PCMK_EXEC_ERROR, "%s: %s",
	                                    name, pcmk_rc_str(error));
	            break;
	        default:
	            services__set_result(op, services__generic_error(op),
	                                 PCMK_EXEC_ERROR, pcmk_rc_str(error));
	    }
	}
	
	/*!
	 * \internal
	 * \brief Exit a child process that failed before executing agent
	 *
	 * \param[in] op           Action that failed
	 * \param[in] exit_status  Exit status code to use
	 * \param[in] exit_reason  Exit reason to output if for OCF agent
	 */
	static void
	exit_child(const svc_action_t *op, int exit_status, const char *exit_reason)
	{
	    if ((op != NULL) && (exit_reason != NULL)
	        && pcmk__str_eq(op->standard, PCMK_RESOURCE_CLASS_OCF,
	                        pcmk__str_none)) {
	        fprintf(stderr, PCMK_OCF_REASON_PREFIX "%s\n", exit_reason);
	    }
	    pcmk_common_cleanup();
	    _exit(exit_status);
	}
	
	static void
	action_launch_child(svc_action_t *op)
	{
	    int rc;
	
	    /* SIGPIPE is ignored (which is different from signal blocking) by the gnutls library.
	     * Depending on the libqb version in use, libqb may set SIGPIPE to be ignored as well. 
	     * We do not want this to be inherited by the child process. By resetting this the signal
	     * to the default behavior, we avoid some potential odd problems that occur during OCF
	     * scripts when SIGPIPE is ignored by the environment. */
	    signal(SIGPIPE, SIG_DFL);
	
	    if (sched_getscheduler(0) != SCHED_OTHER) {
	        struct sched_param sp;
	
	        memset(&sp, 0, sizeof(sp));
	        sp.sched_priority = 0;
	
	        if (sched_setscheduler(0, SCHED_OTHER, &sp) == -1) {
	            pcmk__info("Could not reset scheduling policy for %s", op->id);
	        }
	    }
	
	    if (setpriority(PRIO_PROCESS, 0, 0) == -1) {
	        pcmk__info("Could not reset process priority for %s", op->id);
	    }
	
	    /* Man: The call setpgrp() is equivalent to setpgid(0,0)
	     * _and_ compiles on BSD variants too
	     * need to investigate if it works the same too.
	     */
	    setpgid(0, 0);
	
	    pcmk__close_fds_in_child();
	
	    /* It would be nice if errors in this function could be reported as
	     * execution status (for example, PCMK_EXEC_NO_SECRETS for the secrets error
	     * below) instead of exit status. However, we've already forked, so
	     * exit status is all we have. At least for OCF actions, we can output an
	     * exit reason for the parent to parse.
	     *
	     * @TODO It might be better to substitute secrets in the parent before
	     * forking, so that if it fails, we can give a better message and result,
	     * and avoid the fork.
	     */
	
	#if PCMK__ENABLE_CIBSECRETS
	    rc = pcmk__substitute_secrets(op->rsc, op->params);
	    if (rc != pcmk_rc_ok) {
	        if (pcmk__str_eq(op->action, PCMK_ACTION_STOP, pcmk__str_casei)) {
	            pcmk__info("Proceeding with stop operation for %s despite being "
	                       "unable to load CIB secrets (%s)",
	                       op->rsc, pcmk_rc_str(rc));
	        } else {
	            pcmk__err("Considering %s unconfigured because unable to load CIB "
	                      "secrets: %s",
	                      op->rsc, pcmk_rc_str(rc));
	            exit_child(op, services__configuration_error(op, false),
	                       "Unable to load CIB secrets");
	        }
	    }
	#endif
	
	    add_action_env_vars(op);
	
	    /* Become the desired user */
	    if (op->opaque->uid && (geteuid() == 0)) {
	
	        // If requested, set effective group
	        if (op->opaque->gid && (setgid(op->opaque->gid) < 0)) {
	            pcmk__err("Considering %s unauthorized because could not set child "
	                      "group to %d: %s",
	                      op->id, op->opaque->gid, strerror(errno));
	            exit_child(op, services__authorization_error(op),
	                       "Could not set group for child process");
	        }
	
	        // Erase supplementary group list
	        // (We could do initgroups() if we kept a copy of the username)
	        if (setgroups(0, NULL) < 0) {
	            pcmk__err("Considering %s unauthorized because could not clear "
	                      "supplementary groups: %s",
	                      op->id, strerror(errno));
	            exit_child(op, services__authorization_error(op),
	                       "Could not clear supplementary groups for child process");
	        }
	
	        // Set effective user
	        if (setuid(op->opaque->uid) < 0) {
	            pcmk__err("Considering %s unauthorized because could not set user "
	                      "to %d: %s",
	                      op->id, op->opaque->uid, strerror(errno));
	            exit_child(op, services__authorization_error(op),
	                       "Could not set user for child process");
	        }
	    }
	
	    // Execute the agent (doesn't return if successful)
	    execvp(op->opaque->exec, op->opaque->args);
	
	    // An earlier stat() should have avoided most possible errors
	    rc = errno;
	    services__handle_exec_error(op, rc);
	    pcmk__err("Unable to execute %s: %s", op->id, strerror(rc));
	    exit_child(op, op->rc, "Child process was unable to execute file");
	}
	
	/*!
	 * \internal
	 * \brief Wait for synchronous action to complete, and set its result
	 *
	 * \param[in,out] op    Action to wait for
	 * \param[in,out] data  Child signal data
	 */
	static void
	wait_for_sync_result(svc_action_t *op, struct sigchld_data_s *data)
	{
	    int status = 0;
	    int timeout = op->timeout;
	    time_t start = time(NULL);
	    struct pollfd fds[3];
	    int wait_rc = 0;
	    const char *wait_reason = NULL;
	
	    fds[0].fd = op->opaque->stdout_fd;
	    fds[0].events = POLLIN;
	    fds[0].revents = 0;
	
	    fds[1].fd = op->opaque->stderr_fd;
	    fds[1].events = POLLIN;
	    fds[1].revents = 0;
	
	    fds[2].fd = sigchld_open(data);
	    fds[2].events = POLLIN;
	    fds[2].revents = 0;
	
	    pcmk__trace("Waiting for %s[%d]", op->id, op->pid);
	    do {
	        int poll_rc = poll(fds, 3, timeout);
	
	        wait_reason = NULL;
	
	        if (poll_rc > 0) {
	            if (fds[0].revents & POLLIN) {
	                svc_read_output(op->opaque->stdout_fd, op, FALSE);
	            }
	
	            if (fds[1].revents & POLLIN) {
	                svc_read_output(op->opaque->stderr_fd, op, TRUE);
	            }
	
	            if ((fds[2].revents & POLLIN)
	                && sigchld_received(fds[2].fd, op->pid, data)) {
	                wait_rc = waitpid(op->pid, &status, WNOHANG);
	
	                if ((wait_rc > 0) || ((wait_rc < 0) && (errno == ECHILD))) {
	                    // Child process exited or doesn't exist
	                    break;
	
	                } else if (wait_rc < 0) {
	                    wait_reason = pcmk_rc_str(errno);
	                    pcmk__info("Wait for completion of %s[%d] failed: %s "
	                               QB_XS " source=waitpid",
	                               op->id, op->pid, wait_reason);
	                    wait_rc = 0; // Act as if process is still running
	
	#ifndef HAVE_SYS_SIGNALFD_H
	                } else {
	                   /* The child hasn't exited, so this SIGCHLD could be for
	                    * another child. We have to ignore it here but will still
	                    * need to resend it after this synchronous action has
	                    * completed and SIGCHLD has been restored to be handled by
	                    * the previous handler, so that it will be handled.
	                    */
	                    data->ignored = true;
	#endif
	                }
	            }
	
	        } else if (poll_rc == 0) {
	            // Poll timed out with no descriptors ready
	            timeout = 0;
	            break;
	
	        } else if ((poll_rc < 0) && (errno != EINTR)) {
	            wait_reason = pcmk_rc_str(errno);
	            pcmk__info("Wait for completion of %s[%d] failed: %s "
	                       QB_XS " source=poll",
	                       op->id, op->pid, wait_reason);
	            break;
	        }
	
	        timeout = op->timeout - (time(NULL) - start) * 1000;
	
	    } while ((op->timeout < 0 || timeout > 0));
	
	    pcmk__trace("Stopped waiting for %s[%d]", op->id, op->pid);
	    finish_op_output(op, true);
	    finish_op_output(op, false);
	    close_op_input(op);
	    sigchld_close(fds[2].fd);
	
	    if (wait_rc <= 0) {
	
	        if ((op->timeout > 0) && (timeout <= 0)) {
	            services__format_result(op, services__generic_error(op),
	                                    PCMK_EXEC_TIMEOUT,
	                                    "%s did not exit within specified timeout",
	                                    services__action_kind(op));
	            pcmk__info("%s[%d] timed out after %dms", op->id, op->pid,
	                       op->timeout);
	
	        } else {
	            services__set_result(op, services__generic_error(op),
	                                 PCMK_EXEC_ERROR, wait_reason);
	        }
	
	        /* If only child hasn't been successfully waited for, yet.
	           This is to limit killing wrong target a bit more. */
	        if ((wait_rc == 0) && (waitpid(op->pid, &status, WNOHANG) == 0)) {
	            if (kill(op->pid, SIGKILL)) {
	                pcmk__warn("Could not kill rogue child %s[%d]: %s", op->id,
	                           op->pid, pcmk_rc_str(errno));
	            }
	            /* Safe to skip WNOHANG here as we sent non-ignorable signal. */
	            while ((waitpid(op->pid, &status, 0) == (pid_t) -1)
	                   && (errno == EINTR)) {
	                /* keep waiting */;
	            }
	        }
	
	    } else if (WIFEXITED(status)) {
	        services__set_result(op, WEXITSTATUS(status), PCMK_EXEC_DONE, NULL);
	        parse_exit_reason_from_stderr(op);
	        pcmk__info("%s[%d] exited with status %d", op->id, op->pid, op->rc);
	
	    } else if (WIFSIGNALED(status)) {
	        int signo = WTERMSIG(status);
	
	        services__format_result(op, services__generic_error(op),
	                                PCMK_EXEC_ERROR, "%s interrupted by %s signal",
	                                services__action_kind(op), strsignal(signo));
	        pcmk__info("%s[%d] terminated with signal %d (%s)", op->id, op->pid,
	                   signo, strsignal(signo));
	
	#ifdef WCOREDUMP
	        if (WCOREDUMP(status)) {
	            pcmk__warn("%s[%d] dumped core", op->id, op->pid);
	        }
	#endif
	
	    } else {
	        // Shouldn't be possible to get here
	        services__set_result(op, services__generic_error(op), PCMK_EXEC_ERROR,
	                             "Unable to wait for child to complete");
	    }
	}
	
	/*!
	 * \internal
	 * \brief Execute an action whose standard uses executable files
	 *
	 * \param[in,out] op  Action to execute
	 *
	 * \return Standard Pacemaker return value
	 * \retval EBUSY          Recurring operation could not be initiated
	 * \retval pcmk_rc_error  Synchronous action failed
	 * \retval pcmk_rc_ok     Synchronous action succeeded, or asynchronous action
	 *                        should not be freed (because it's pending or because
	 *                        it failed to execute and was already freed)
	 *
	 * \note If the return value for an asynchronous action is not pcmk_rc_ok, the
	 *       caller is responsible for freeing the action.
	 */
	int
	services__execute_file(svc_action_t *op)
	{
	    int stdout_fd[2];
	    int stderr_fd[2];
	    int stdin_fd[2] = {-1, -1};
	    int rc;
	    struct stat st;
	    struct sigchld_data_s data = { .ignored = false };
	
	    // Catch common failure conditions early
	    if (stat(op->opaque->exec, &st) != 0) {
	        rc = errno;
	        pcmk__info("Cannot execute '%s': %s " QB_XS " stat rc=%d",
	                   op->opaque->exec, pcmk_rc_str(rc), rc);
	        services__handle_exec_error(op, rc);
	        goto done;
	    }
	
	    if (pipe(stdout_fd) < 0) {
	        rc = errno;
	        pcmk__info("Cannot execute '%s': %s " QB_XS " pipe(stdout) rc=%d",
	                   op->opaque->exec, pcmk_rc_str(rc), rc);
	        services__handle_exec_error(op, rc);
	        goto done;
	    }
	
	    if (pipe(stderr_fd) < 0) {
	        rc = errno;
	
	        close_pipe(stdout_fd);
	
	        pcmk__info("Cannot execute '%s': %s " QB_XS " pipe(stderr) rc=%d",
	                   op->opaque->exec, pcmk_rc_str(rc), rc);
	        services__handle_exec_error(op, rc);
	        goto done;
	    }
	
	    if (pcmk__is_set(pcmk_get_ra_caps(op->standard), pcmk_ra_cap_stdin)) {
	        if (pipe(stdin_fd) < 0) {
	            rc = errno;
	
	            close_pipe(stdout_fd);
	            close_pipe(stderr_fd);
	
	            pcmk__info("Cannot execute '%s': %s " QB_XS " pipe(stdin) rc=%d",
	                       op->opaque->exec, pcmk_rc_str(rc), rc);
	            services__handle_exec_error(op, rc);
	            goto done;
	        }
	    }
	
	    if (op->synchronous && !sigchld_setup(&data)) {
	        close_pipe(stdin_fd);
	        close_pipe(stdout_fd);
	        close_pipe(stderr_fd);
	        sigchld_cleanup(&data);
	        services__set_result(op, services__generic_error(op), PCMK_EXEC_ERROR,
	                             "Could not manage signals for child process");
	        goto done;
	    }
	
	    op->pid = fork();
	    switch (op->pid) {
	        case -1:
	            rc = errno;
	            close_pipe(stdin_fd);
	            close_pipe(stdout_fd);
	            close_pipe(stderr_fd);
	
	            pcmk__info("Cannot execute '%s': %s " QB_XS " fork rc=%d",
	                       op->opaque->exec, pcmk_rc_str(rc), rc);
	            services__handle_exec_error(op, rc);
	            if (op->synchronous) {
	                sigchld_cleanup(&data);
	            }
	            goto done;
	            break;
	
	        case 0:                /* Child */
	            close(stdout_fd[0]);
	            close(stderr_fd[0]);
	            if (stdin_fd[1] >= 0) {
	                close(stdin_fd[1]);
	            }
	            if (STDOUT_FILENO != stdout_fd[1]) {
	                if (dup2(stdout_fd[1], STDOUT_FILENO) != STDOUT_FILENO) {
	                    pcmk__warn("Can't redirect output from '%s': %s "
	                               QB_XS " errno=%d",
	                               op->opaque->exec, pcmk_rc_str(errno), errno);
	                }
	                close(stdout_fd[1]);
	            }
	            if (STDERR_FILENO != stderr_fd[1]) {
	                if (dup2(stderr_fd[1], STDERR_FILENO) != STDERR_FILENO) {
	                    pcmk__warn("Can't redirect error output from '%s': %s "
	                               QB_XS " errno=%d",
	                               op->opaque->exec, pcmk_rc_str(errno), errno);
	                }
	                close(stderr_fd[1]);
	            }
	            if ((stdin_fd[0] >= 0) &&
	                (STDIN_FILENO != stdin_fd[0])) {
	                if (dup2(stdin_fd[0], STDIN_FILENO) != STDIN_FILENO) {
	                    pcmk__warn("Can't redirect input to '%s': %s "
	                               QB_XS " errno=%d",
	                               op->opaque->exec, pcmk_rc_str(errno), errno);
	                }
	                close(stdin_fd[0]);
	            }
	
	            if (op->synchronous) {
	                sigchld_cleanup(&data);
	            }
	
	            action_launch_child(op);
	            pcmk__assert(false); // action_launch_child() should not return
	    }
	
	    /* Only the parent reaches here */
	    close(stdout_fd[1]);
	    close(stderr_fd[1]);
	    if (stdin_fd[0] >= 0) {
	        close(stdin_fd[0]);
	    }
	
	    op->opaque->stdout_fd = stdout_fd[0];
	    rc = pcmk__set_nonblocking(op->opaque->stdout_fd);
	    if (rc != pcmk_rc_ok) {
	        pcmk__info("Could not set '%s' output non-blocking: %s "
	                   QB_XS " rc=%d",
	                   op->opaque->exec, pcmk_rc_str(rc), rc);
	    }
	
	    op->opaque->stderr_fd = stderr_fd[0];
	    rc = pcmk__set_nonblocking(op->opaque->stderr_fd);
	    if (rc != pcmk_rc_ok) {
	        pcmk__info("Could not set '%s' error output non-blocking: %s "
	                   QB_XS " rc=%d",
	                   op->opaque->exec, pcmk_rc_str(rc), rc);
	    }
	
	    op->opaque->stdin_fd = stdin_fd[1];
	    if (op->opaque->stdin_fd >= 0) {
	        // using buffer behind non-blocking-fd here - that could be improved
	        // as long as no other standard uses stdin_fd assume stonith
	        rc = pcmk__set_nonblocking(op->opaque->stdin_fd);
	        if (rc != pcmk_rc_ok) {
	            pcmk__info("Could not set '%s' input non-blocking: %s "
	                       QB_XS " fd=%d,rc=%d", op->opaque->exec,
	                       pcmk_rc_str(rc), op->opaque->stdin_fd, rc);
	        }
	        pipe_in_action_stdin_parameters(op);
	        // as long as we are handling parameters directly in here just close
	        close(op->opaque->stdin_fd);
	        op->opaque->stdin_fd = -1;
	    }
	
	    // after fds are setup properly and before we plug anything into mainloop
	    if (op->opaque->fork_callback) {
	        op->opaque->fork_callback(op);
	    }
	
	    if (op->synchronous) {
	        wait_for_sync_result(op, &data);
	        sigchld_cleanup(&data);
	        goto done;
	    }
	
	    pcmk__trace("Waiting async for '%s'[%d]", op->opaque->exec, op->pid);
	    if (pcmk__is_set(op->flags, SVC_ACTION_LEAVE_GROUP)) {
	        mainloop_child_add_with_flags(op->pid, op->timeout, op->id, op,
	                                      mainloop_leave_pid_group,
	                                      async_action_complete);
	    } else {
	        mainloop_child_add_with_flags(op->pid, op->timeout, op->id, op, 0,
	                                      async_action_complete);
	    }
	
	    op->opaque->stdout_gsource = mainloop_add_fd(op->id,
	                                                 G_PRIORITY_LOW,
	                                                 op->opaque->stdout_fd, op,
	                                                 &stdout_callbacks);
	    op->opaque->stderr_gsource = mainloop_add_fd(op->id,
	                                                 G_PRIORITY_LOW,
	                                                 op->opaque->stderr_fd, op,
	                                                 &stderr_callbacks);
	    services_add_inflight_op(op);
	    return pcmk_rc_ok;
	
	done:
	    if (op->synchronous) {
	        return (op->rc == PCMK_OCF_OK)? pcmk_rc_ok : pcmk_rc_error;
	    } else {
	        return services__finalize_async_op(op);
	    }
	}
	
	/*!
	 * \internal
	 * \brief \c scandir() filter for non-hidden executable regular files
	 *
	 * \param[in] entry  Directory entry
	 *
	 * \retval 1 if the entry is an executable regular file and its name does not
	 *           begin with \c "."
	 * \retval 0 otherwise
	 */
	static int
	exec_file_filter(const struct dirent *entry)
	{
	    char *buf = NULL;
	    struct stat sb;
	    int rc = 0;
	
	    if (entry->d_name[0] == '.') {
	        return rc;
	    }
	
	    buf = pcmk__assert_asprintf("%s/%s", filter_dir, entry->d_name);
	
	    if ((stat(buf, &sb) == 0) && S_ISREG(sb.st_mode)
	        && pcmk__any_flags_set(sb.st_mode, S_IXUSR|S_IXGRP|S_IXOTH)) {
	
	        rc = 1;
	    }
	
	    free(buf);
	    return rc;
	}
	
	/*!
	 * \internal
	 * \brief \c scandir() filter for non-hidden directories
	 *
	 * \param[in] entry  Directory entry
	 *
	 * \retval 1 if the entry is a directory and its name does not begin with \c "."
	 * \retval 0 otherwise
	 */
	static int
	directory_filter(const struct dirent *entry)
	{
	    char *buf = NULL;
	    struct stat sb;
	    int rc = 0;
	
	    if (entry->d_name[0] == '.') {
	        return rc;
	    }
	
	    buf = pcmk__assert_asprintf("%s/%s", filter_dir, entry->d_name);
	
	    if ((stat(buf, &sb) == 0) && S_ISDIR(sb.st_mode)) {
	        rc = 1;
	    }
	
	    free(buf);
	    return rc;
	}
	
	/*!
	 * \internal
	 * \brief List directory's top-level contents of the given type
	 *
	 * Hidden files (those beginning with \c '.') are skipped.
	 *
	 * \param[in] dir         Full path of directory to list
	 * \param[in] exec_files  If \c true, list only executable files within \p dir.
	 *                        If \c false, list only directories within \p dir.
	 *
	 * \return Newly allocated list of newly allocated names of directory entries
	 *
	 * \note The caller is responsible for freeing the return value using
	 *       <tt>g_list_free_full(list, free)</tt>.
	 */
	GList *
	services__list_dir(const char *dir, bool exec_files)
	{
	    GList *list = NULL;
	    struct dirent **namelist = NULL;
	    int entries = 0;
	
	    filter_dir = dir;
	    entries = scandir(dir, &namelist,
	                      (exec_files? exec_file_filter : directory_filter),
	                      alphasort);
	    filter_dir = NULL;
	
	    if (entries < 0) {
	        return NULL;
	    }
	
	    for (int i = 0; i < entries; i++) {
	        list = g_list_append(list, pcmk__str_copy(namelist[i]->d_name));
	        free(namelist[i]);
	    }
	    free(namelist);
	    return list;
	}