Revert "Migrate check_users to new ouput infrastructure"

This reverts commit 10086edbf03fd807794bcfb3fff626da69a9fdb2.

5 files changed, 130 insertions, 323 deletions

diff --git a/plugins/Makefile.am b/plugins/Makefile.am
index e0069653..d43c1971 100644
--- a/plugins/Makefile.am
+++ b/plugins/Makefile.am
@@ -125,7 +125,6 @@ check_time_LDADD = $(NETLIBS)
 check_ntp_time_LDADD = $(NETLIBS) $(MATHLIBS)
 check_ups_LDADD = $(NETLIBS)
 check_users_LDADD = $(BASEOBJS) $(WTSAPI32LIBS) $(SYSTEMDLIBS)
-check_users_SOURCES = check_users.c check_users.d/users.c
 check_by_ssh_LDADD = $(NETLIBS)
 check_ide_smart_LDADD = $(BASEOBJS)
 negate_LDADD = $(BASEOBJS)
diff --git a/plugins/check_users.c b/plugins/check_users.c
index 6ec87d21..f1e1c39d 100644
--- a/plugins/check_users.c
+++ b/plugins/check_users.c
@@ -3,7 +3,7 @@
  * Monitoring check_users plugin
  *
  * License: GPL
- * Copyright (c) 2000-2025 Monitoring Plugins Development Team
+ * Copyright (c) 2000-2024 Monitoring Plugins Development Team
  *
  * Description:
  *
@@ -30,19 +30,12 @@
  *
  *****************************************************************************/
 
-#include "check_users.d/config.h"
-#include "thresholds.h"
 const char *progname = "check_users";
-const char *copyright = "2000-2025";
+const char *copyright = "2000-2024";
 const char *email = "devel@monitoring-plugins.org";
 
-#include "check_users.d/users.h"
-#include "output.h"
-#include "perfdata.h"
-#include "states.h"
-#include "utils_base.h"
-#include "./common.h"
-#include "./utils.h"
+#include "common.h"
+#include "utils.h"
 
 #if HAVE_WTSAPI32_H
 #       include <windows.h>
@@ -60,16 +53,29 @@ const char *email = "devel@monitoring-plugins.org";
 #       include <systemd/sd-login.h>
 #endif
 
-typedef struct process_argument_wrapper {
-        int errorcode;
-        check_users_config config;
-} process_argument_wrapper;
+#define possibly_set(a, b) ((a) == 0 ? (b) : 0)
 
-process_argument_wrapper process_arguments(int /*argc*/, char ** /*argv*/);
-void print_help(void);
+static int process_arguments(int, char **);
+static void print_help(void);
 void print_usage(void);
 
+static char *warning_range = NULL;
+static char *critical_range = NULL;
+static thresholds *thlds = NULL;
+
 int main(int argc, char **argv) {
+        int users = -1;
+        int result = STATE_UNKNOWN;
+#if HAVE_WTSAPI32_H
+        WTS_SESSION_INFO *wtsinfo;
+        DWORD wtscount;
+        DWORD index;
+#elif HAVE_UTMPX_H
+        struct utmpx *putmpx;
+#else
+        char input_buffer[MAX_INPUT_BUFFER];
+#endif
+
         setlocale(LC_ALL, "");
         bindtextdomain(PACKAGE, LOCALEDIR);
         textdomain(PACKAGE);
@@ -77,106 +83,121 @@ int main(int argc, char **argv) {
         /* Parse extra opts if any */
         argv = np_extra_opts(&argc, argv, progname);
 
-        process_argument_wrapper tmp = process_arguments(argc, argv);
-
-        if (tmp.errorcode == ERROR) {
+        if (process_arguments(argc, argv) == ERROR)
                 usage4(_("Could not parse arguments"));
-        }
 
-        check_users_config config = tmp.config;
+        users = 0;
+
+#ifdef HAVE_LIBSYSTEMD
+        if (sd_booted() > 0)
+                users = sd_get_sessions(NULL);
+        else {
+#endif
+#if HAVE_WTSAPI32_H
+                if (!WTSEnumerateSessions(WTS_CURRENT_SERVER_HANDLE, 0, 1, &wtsinfo, &wtscount)) {
+                        printf(_("Could not enumerate RD sessions: %d\n"), GetLastError());
+                        return STATE_UNKNOWN;
+                }
+
+                for (index = 0; index < wtscount; index++) {
+                        LPTSTR username;
+                        DWORD size;
+                        int len;
 
-#ifdef _WIN32
-#       if HAVE_WTSAPI32_H
-        get_num_of_users_wrapper user_wrapper = get_num_of_users_windows();
-#       else
-#               error Did not find WTSAPI32
-#       endif // HAVE_WTSAPI32_H
+                        if (!WTSQuerySessionInformation(WTS_CURRENT_SERVER_HANDLE, wtsinfo[index].SessionId, WTSUserName, &username, &size))
+                                continue;
+
+                        len = lstrlen(username);
+
+                        WTSFreeMemory(username);
+
+                        if (len == 0)
+                                continue;
+
+                        if (wtsinfo[index].State == WTSActive || wtsinfo[index].State == WTSDisconnected)
+                                users++;
+                }
+
+                WTSFreeMemory(wtsinfo);
+#elif HAVE_UTMPX_H
+        /* get currently logged users from utmpx */
+        setutxent();
+
+        while ((putmpx = getutxent()) != NULL)
+                if (putmpx->ut_type == USER_PROCESS)
+                        users++;
+
+        endutxent();
 #else
-#       ifdef HAVE_LIBSYSTEMD
-        get_num_of_users_wrapper user_wrapper = get_num_of_users_systemd();
-#       elif HAVE_UTMPX_H
-        get_num_of_users_wrapper user_wrapper = get_num_of_users_utmp();
-#       else  // !HAVE_LIBSYSTEMD && !HAVE_UTMPX_H
-        get_num_of_users_wrapper user_wrapper = get_num_of_users_who_command();
-#       endif // HAVE_LIBSYSTEMD
-#endif     // _WIN32
-
-        mp_check overall = mp_check_init();
-        mp_subcheck sc_users = mp_subcheck_init();
-
-        if (user_wrapper.errorcode != 0) {
-                sc_users = mp_set_subcheck_state(sc_users, STATE_UNKNOWN);
-                sc_users.output = "Failed to retrieve number of users";
-                mp_add_subcheck_to_check(&overall, sc_users);
-                mp_exit(overall);
+        /* run the command */
+        child_process = spopen(WHO_COMMAND);
+        if (child_process == NULL) {
+                printf(_("Could not open pipe: %s\n"), WHO_COMMAND);
+                return STATE_UNKNOWN;
         }
+
+        child_stderr = fdopen(child_stderr_array[fileno(child_process)], "r");
+        if (child_stderr == NULL)
+                printf(_("Could not open stderr for %s\n"), WHO_COMMAND);
+
+        while (fgets(input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
+                /* increment 'users' on all lines except total user count */
+                if (input_buffer[0] != '#') {
+                        users++;
+                        continue;
+                }
+
+                /* get total logged in users */
+                if (sscanf(input_buffer, _("# users=%d"), &users) == 1)
+                        break;
+        }
+
+        /* check STDERR */
+        if (fgets(input_buffer, MAX_INPUT_BUFFER - 1, child_stderr))
+                result = possibly_set(result, STATE_UNKNOWN);
+        (void)fclose(child_stderr);
+
+        /* close the pipe */
+        if (spclose(child_process))
+                result = possibly_set(result, STATE_UNKNOWN);
+#endif
+#ifdef HAVE_LIBSYSTEMD
+        }
+#endif
+
         /* check the user count against warning and critical thresholds */
+        result = get_status((double)users, thlds);
 
-        mp_perfdata users_pd = {
-                .label = "users",
-                .value = mp_create_pd_value(user_wrapper.users),
-        };
-
-        users_pd = mp_pd_set_thresholds(users_pd, config.thresholds);
-        mp_add_perfdata_to_subcheck(&sc_users, users_pd);
-
-        int tmp_status = mp_get_pd_status(users_pd);
-        sc_users = mp_set_subcheck_state(sc_users, tmp_status);
-
-        switch (tmp_status) {
-        case STATE_WARNING:
-                xasprintf(&sc_users.output, "%d users currently logged in. This violates the warning threshold", user_wrapper.users);
-                break;
-        case STATE_CRITICAL:
-                xasprintf(&sc_users.output, "%d users currently logged in. This violates the critical threshold", user_wrapper.users);
-                break;
-        default:
-                xasprintf(&sc_users.output, "%d users currently logged in", user_wrapper.users);
+        if (result == STATE_UNKNOWN)
+                printf("%s\n", _("Unable to read output"));
+        else {
+                printf(_("USERS %s - %d users currently logged in |%s\n"), state_text(result), users,
+                           sperfdata_int("users", users, "", warning_range, critical_range, true, 0, false, 0));
         }
 
-        mp_add_subcheck_to_check(&overall, sc_users);
-        mp_exit(overall);
+        return result;
 }
 
-#define output_format_index CHAR_MAX + 1
-
 /* process command-line arguments */
-process_argument_wrapper process_arguments(int argc, char **argv) {
+int process_arguments(int argc, char **argv) {
         static struct option longopts[] = {{"critical", required_argument, 0, 'c'},
                                                                            {"warning", required_argument, 0, 'w'},
                                                                            {"version", no_argument, 0, 'V'},
                                                                            {"help", no_argument, 0, 'h'},
-                                                                           {"output-format", required_argument, 0, output_format_index},
                                                                            {0, 0, 0, 0}};
 
-        if (argc < 2) {
+        if (argc < 2)
                 usage("\n");
-        }
-
-        char *warning_range = NULL;
-        char *critical_range = NULL;
-        check_users_config config = check_users_config_init();
 
+        int option_char;
         while (true) {
-                int counter = getopt_long(argc, argv, "+hVvc:w:", longopts, NULL);
+                int option = 0;
+                option_char = getopt_long(argc, argv, "+hVvc:w:", longopts, &option);
 
-                if (counter == -1 || counter == EOF || counter == 1) {
+                if (option_char == -1 || option_char == EOF || option_char == 1)
                         break;
-                }
 
-                switch (counter) {
-                case output_format_index: {
-                        parsed_output_format parser = mp_parse_output_format(optarg);
-                        if (!parser.parsing_success) {
-                                // TODO List all available formats here, maybe add anothoer usage function
-                                printf("Invalid output format: %s\n", optarg);
-                                exit(STATE_UNKNOWN);
-                        }
-
-                        config.output_format_is_set = true;
-                        config.output_format = parser.output_format;
-                        break;
-                }
+                switch (option_char) {
                 case '?': /* print short usage statement if args not parsable */
                         usage5();
                 case 'h': /* help */
@@ -194,35 +215,26 @@ process_argument_wrapper process_arguments(int argc, char **argv) {
                 }
         }
 
-        // TODO add proper verification for ranges here!
-        if (warning_range) {
-                mp_range_parsed tmp = mp_parse_range_string(warning_range);
-                if (tmp.error == MP_PARSING_SUCCES) {
-                        config.thresholds.warning = tmp.range;
-                        config.thresholds.warning_is_set = true;
-                } else {
-                        printf("Failed to parse warning range: %s", warning_range);
-                        exit(STATE_UNKNOWN);
-                }
-        }
+        option_char = optind;
 
-        if (critical_range) {
-                mp_range_parsed tmp = mp_parse_range_string(critical_range);
-                if (tmp.error == MP_PARSING_SUCCES) {
-                        config.thresholds.critical = tmp.range;
-                        config.thresholds.critical_is_set = true;
-                } else {
-                        printf("Failed to parse critical range: %s", critical_range);
-                        exit(STATE_UNKNOWN);
-                }
+        if (warning_range == NULL && argc > option_char)
+                warning_range = argv[option_char++];
+
+        if (critical_range == NULL && argc > option_char)
+                critical_range = argv[option_char++];
+
+        /* this will abort in case of invalid ranges */
+        set_thresholds(&thlds, warning_range, critical_range);
+
+        if (!thlds->warning) {
+                usage4(_("Warning threshold must be a valid range expression"));
         }
 
-        process_argument_wrapper result = {
-                .errorcode = OK,
-                .config = config,
-        };
+        if (!thlds->critical) {
+                usage4(_("Critical threshold must be a valid range expression"));
+        }
 
-        return result;
+        return OK;
 }
 
 void print_help(void) {
@@ -245,7 +257,6 @@ void print_help(void) {
         printf("    %s\n", _("Set WARNING status if number of logged in users violates RANGE_EXPRESSION"));
         printf(" %s\n", "-c, --critical=RANGE_EXPRESSION");
         printf("    %s\n", _("Set CRITICAL status if number of logged in users violates RANGE_EXPRESSION"));
-        printf(UT_OUTPUT_FORMAT);
 
         printf(UT_SUPPORT);
 }
diff --git a/plugins/check_users.d/config.h b/plugins/check_users.d/config.h
deleted file mode 100644
index 35b7b7f8..00000000
--- a/plugins/check_users.d/config.h
+++ /dev/null
@@ -1,19 +0,0 @@
-#pragma once
-
-#include "output.h"
-#include "thresholds.h"
-typedef struct check_users_config {
-        mp_thresholds thresholds;
-
-        bool output_format_is_set;
-        mp_output_format output_format;
-} check_users_config;
-
-check_users_config check_users_config_init() {
-        check_users_config tmp = {
-                .thresholds = mp_thresholds_init(),
-
-                .output_format_is_set = false,
-        };
-        return tmp;
-}
diff --git a/plugins/check_users.d/users.c b/plugins/check_users.d/users.c
deleted file mode 100644
index 7969ae79..00000000
--- a/plugins/check_users.d/users.c
+++ /dev/null
@@ -1,166 +0,0 @@
-#include "./users.h"
-
-#ifdef _WIN32
-#       ifdef HAVE_WTSAPI32_H
-#               include <windows.h>
-#               include <wtsapi32.h>
-#               undef ERROR
-#               define ERROR -1
-
-get_num_of_users_wrapper get_num_of_users_windows() {
-        WTS_SESSION_INFO *wtsinfo;
-        DWORD wtscount;
-
-        get_num_of_users_wrapper result = {};
-
-        if (!WTSEnumerateSessions(WTS_CURRENT_SERVER_HANDLE, 0, 1, &wtsinfo, &wtscount)) {
-                // printf(_("Could not enumerate RD sessions: %d\n"), GetLastError());
-                result.error = WINDOWS_COULD_NOT_ENUMERATE_SESSIONS;
-                return result;
-        }
-
-        for (DWORD index = 0; index < wtscount; index++) {
-                LPTSTR username;
-                DWORD size;
-
-                if (!WTSQuerySessionInformation(WTS_CURRENT_SERVER_HANDLE, wtsinfo[index].SessionId, WTSUserName, &username, &size)) {
-                        continue;
-                }
-
-                int len = lstrlen(username);
-
-                WTSFreeMemory(username);
-
-                if (len == 0) {
-                        continue;
-                }
-
-                if (wtsinfo[index].State == WTSActive || wtsinfo[index].State == WTSDisconnected) {
-                        result.users++;
-                }
-        }
-
-        WTSFreeMemory(wtsinfo);
-        return result;
-}
-#       else // HAVE_WTSAPI32_H
-#               error On windows but without the WTSAPI32 lib
-#       endif // HAVE_WTSAPI32_H
-
-#else // _WIN32
-
-#       include "../../config.h"
-
-#       ifdef HAVE_LIBSYSTEMD
-#               include <systemd/sd-daemon.h>
-#               include <systemd/sd-login.h>
-
-get_num_of_users_wrapper get_num_of_users_systemd() {
-        get_num_of_users_wrapper result = {};
-
-        // Test whether we booted with systemd
-        if (sd_booted() > 0) {
-                int users = sd_get_sessions(NULL);
-                if (users >= 0) {
-                        // Success
-                        result.users = users;
-                        return result;
-                }
-
-                // Failure! return the error code
-                result.errorcode = users;
-                return result;
-        }
-
-        // Looks like we are not running systemd,
-        // return with error here
-        result.errorcode = NO_SYSTEMD_ERROR;
-        return result;
-}
-#       endif
-
-#       ifdef HAVE_UTMPX_H
-#               include <utmpx.h>
-
-get_num_of_users_wrapper get_num_of_users_utmp() {
-        int users = 0;
-
-        /* get currently logged users from utmpx */
-        setutxent();
-
-        struct utmpx *putmpx;
-        while ((putmpx = getutxent()) != NULL) {
-                if (putmpx->ut_type == USER_PROCESS) {
-                        users++;
-                }
-        }
-
-        endutxent();
-
-        get_num_of_users_wrapper result = {
-                .errorcode = 0,
-                .users = users,
-        };
-
-        return result;
-}
-#       endif
-
-#       ifndef HAVE_WTSAPI32_H
-#               ifndef HAVE_LIBSYSTEMD
-#                       ifndef HAVE_UTMPX_H
-//  Fall back option here for the others (probably still not on windows)
-
-#                               include "../popen.h"
-#                               include "../common.h"
-#                               include "../utils.h"
-
-get_num_of_users_wrapper get_num_of_users_who_command() {
-        /* run the command */
-        child_process = spopen(WHO_COMMAND);
-        if (child_process == NULL) {
-                // printf(_("Could not open pipe: %s\n"), WHO_COMMAND);
-                get_num_of_users_wrapper result = {
-                        .errorcode = COULD_NOT_OPEN_PIPE,
-                };
-                return result;
-        }
-
-        child_stderr = fdopen(child_stderr_array[fileno(child_process)], "r");
-        if (child_stderr == NULL) {
-                // printf(_("Could not open stderr for %s\n"), WHO_COMMAND);
-                //  TODO this error should probably be reported
-        }
-
-        get_num_of_users_wrapper result = {};
-        char input_buffer[MAX_INPUT_BUFFER];
-        while (fgets(input_buffer, MAX_INPUT_BUFFER - 1, child_process)) {
-                /* increment 'users' on all lines except total user count */
-                if (input_buffer[0] != '#') {
-                        result.users++;
-                        continue;
-                }
-
-                /* get total logged in users */
-                if (sscanf(input_buffer, _("# users=%d"), &result.users) == 1) {
-                        break;
-                }
-        }
-
-        /* check STDERR */
-        if (fgets(input_buffer, MAX_INPUT_BUFFER - 1, child_stderr)) {
-                // if this fails, something broke and the result can not be relied upon or so is the theorie here
-                result.errorcode = STDERR_COULD_NOT_BE_READ;
-        }
-        (void)fclose(child_stderr);
-
-        /* close the pipe */
-        spclose(child_process);
-
-        return result;
-}
-
-#                       endif
-#               endif
-#       endif
-#endif
diff --git a/plugins/check_users.d/users.h b/plugins/check_users.d/users.h
deleted file mode 100644
index aacba775..00000000
--- a/plugins/check_users.d/users.h
+++ /dev/null
@@ -1,18 +0,0 @@
-#pragma once
-
-typedef struct get_num_of_users_wrapper {
-        int errorcode;
-        int users;
-} get_num_of_users_wrapper;
-
-enum {
-        NO_SYSTEMD_ERROR = 64,
-        WINDOWS_COULD_NOT_ENUMERATE_SESSIONS,
-        COULD_NOT_OPEN_PIPE,
-        STDERR_COULD_NOT_BE_READ,
-};
-
-get_num_of_users_wrapper get_num_of_users_systemd();
-get_num_of_users_wrapper get_num_of_users_utmp();
-get_num_of_users_wrapper get_num_of_users_windows();
-get_num_of_users_wrapper get_num_of_users_who_command();