Merge pull request #2016 from RincewindsHat/fix/check_ssh-variable-stuff

* fix a bug in check_ssh where a variable was used before being set
* clang-format on check_ssh
* do not export local variables from check_ssh
* several style and linter fixes in check_ssh

1 files changed, 178 insertions, 220 deletions

diff --git a/plugins/check_ssh.c b/plugins/check_ssh.c
index e9c55ad7..42a88cf9 100644
--- a/plugins/check_ssh.c
+++ b/plugins/check_ssh.c
@@ -1,32 +1,32 @@
 /*****************************************************************************
-*
-* Monitoring check_ssh plugin
-*
-* License: GPL
-* Copyright (c) 2000-2024 Monitoring Plugins Development Team
-*
-* Description:
-*
-* This file contains the check_ssh plugin
-*
-* Try to connect to an SSH server at specified server and port
-*
-*
-* This program is free software: you can redistribute it and/or modify
-* it under the terms of the GNU General Public License as published by
-* the Free Software Foundation, either version 3 of the License, or
-* (at your option) any later version.
-*
-* This program is distributed in the hope that it will be useful,
-* but WITHOUT ANY WARRANTY; without even the implied warranty of
-* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-* GNU General Public License for more details.
-*
-* You should have received a copy of the GNU General Public License
-* along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*
-*
-*****************************************************************************/
+ *
+ * Monitoring check_ssh plugin
+ *
+ * License: GPL
+ * Copyright (c) 2000-2024 Monitoring Plugins Development Team
+ *
+ * Description:
+ *
+ * This file contains the check_ssh plugin
+ *
+ * Try to connect to an SSH server at specified server and port
+ *
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ *****************************************************************************/
 
 const char *progname = "check_ssh";
 const char *copyright = "2000-2024";
@@ -37,108 +37,96 @@ const char *email = "devel@monitoring-plugins.org";
 #include "utils.h"
 
 #ifndef MSG_DONTWAIT
-#define MSG_DONTWAIT 0
+#       define MSG_DONTWAIT 0
 #endif
 
-#define SSH_DFL_PORT    22
-#define BUFF_SZ         256
+#define SSH_DFL_PORT 22
+#define BUFF_SZ      256
 
-int port = -1;
-char *server_name = NULL;
-char *remote_version = NULL;
-char *remote_protocol = NULL;
-bool verbose = false;
+static int port = -1;
+static char *server_name = NULL;
+static char *remote_version = NULL;
+static char *remote_protocol = NULL;
+static bool verbose = false;
 
-int process_arguments (int, char **);
-int validate_arguments (void);
-void print_help (void);
-void print_usage (void);
+static int process_arguments(int /*argc*/, char ** /*argv*/);
+static int validate_arguments(void);
+static void print_help(void);
+void print_usage(void);
 
-int ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol);
+static int ssh_connect(char *haddr, int hport, char *remote_version, char *remote_protocol);
 
-
-int
-main (int argc, char **argv)
-{
-        int result = STATE_UNKNOWN;
-
-        setlocale (LC_ALL, "");
-        bindtextdomain (PACKAGE, LOCALEDIR);
-        textdomain (PACKAGE);
+int main(int argc, char **argv) {
+        setlocale(LC_ALL, "");
+        bindtextdomain(PACKAGE, LOCALEDIR);
+        textdomain(PACKAGE);
 
         /* Parse extra opts if any */
-        argv=np_extra_opts (&argc, argv, progname);
+        argv = np_extra_opts(&argc, argv, progname);
 
-        if (process_arguments (argc, argv) == ERROR)
-                usage4 (_("Could not parse arguments"));
+        if (process_arguments(argc, argv) == ERROR)
+                usage4(_("Could not parse arguments"));
 
         /* initialize alarm signal handling */
-        signal (SIGALRM, socket_timeout_alarm_handler);
+        signal(SIGALRM, socket_timeout_alarm_handler);
 
-        alarm (socket_timeout);
+        alarm(socket_timeout);
 
         /* ssh_connect exits if error is found */
-        result = ssh_connect (server_name, port, remote_version, remote_protocol);
+        int result = ssh_connect(server_name, port, remote_version, remote_protocol);
 
-        alarm (0);
+        alarm(0);
 
         return (result);
 }
 
-
-
 /* process command-line arguments */
-int
-process_arguments (int argc, char **argv)
-{
-        int c;
-
-        int option = 0;
-        static struct option longopts[] = {
-                {"help", no_argument, 0, 'h'},
-                {"version", no_argument, 0, 'V'},
-                {"host", required_argument, 0, 'H'},    /* backward compatibility */
-                {"hostname", required_argument, 0, 'H'},
-                {"port", required_argument, 0, 'p'},
-                {"use-ipv4", no_argument, 0, '4'},
-                {"use-ipv6", no_argument, 0, '6'},
-                {"timeout", required_argument, 0, 't'},
-                {"verbose", no_argument, 0, 'v'},
-                {"remote-version", required_argument, 0, 'r'},
-                {"remote-protocol", required_argument, 0, 'P'},
-                {0, 0, 0, 0}
-        };
+int process_arguments(int argc, char **argv) {
+        static struct option longopts[] = {{"help", no_argument, 0, 'h'},
+                                                                           {"version", no_argument, 0, 'V'},
+                                                                           {"host", required_argument, 0, 'H'}, /* backward compatibility */
+                                                                           {"hostname", required_argument, 0, 'H'},
+                                                                           {"port", required_argument, 0, 'p'},
+                                                                           {"use-ipv4", no_argument, 0, '4'},
+                                                                           {"use-ipv6", no_argument, 0, '6'},
+                                                                           {"timeout", required_argument, 0, 't'},
+                                                                           {"verbose", no_argument, 0, 'v'},
+                                                                           {"remote-version", required_argument, 0, 'r'},
+                                                                           {"remote-protocol", required_argument, 0, 'P'},
+                                                                           {0, 0, 0, 0}};
 
         if (argc < 2)
                 return ERROR;
 
-        for (c = 1; c < argc; c++)
-                if (strcmp ("-to", argv[c]) == 0)
-                        strcpy (argv[c], "-t");
+        for (int i = 1; i < argc; i++)
+                if (strcmp("-to", argv[i]) == 0)
+                        strcpy(argv[i], "-t");
 
-        while (1) {
-                c = getopt_long (argc, argv, "+Vhv46t:r:H:p:P:", longopts, &option);
+        int option_char;
+        while (true) {
+                int option = 0;
+                option_char = getopt_long(argc, argv, "+Vhv46t:r:H:p:P:", longopts, &option);
 
-                if (c == -1 || c == EOF)
+                if (option_char == -1 || option_char == EOF)
                         break;
 
-                switch (c) {
-                case '?':                                                                       /* help */
-                        usage5 ();
-                case 'V':                                                                       /* version */
-                        print_revision (progname, NP_VERSION);
-                        exit (STATE_UNKNOWN);
-                case 'h':                                                                       /* help */
-                        print_help ();
-                        exit (STATE_UNKNOWN);
-                case 'v':                                                                       /* verbose */
+                switch (option_char) {
+                case '?': /* help */
+                        usage5();
+                case 'V': /* version */
+                        print_revision(progname, NP_VERSION);
+                        exit(STATE_UNKNOWN);
+                case 'h': /* help */
+                        print_help();
+                        exit(STATE_UNKNOWN);
+                case 'v': /* verbose */
                         verbose = true;
                         break;
-                case 't':                                                                       /* timeout period */
-                        if (!is_integer (optarg))
-                                usage2 (_("Timeout interval must be a positive integer"), optarg);
+                case 't': /* timeout period */
+                        if (!is_integer(optarg))
+                                usage2(_("Timeout interval must be a positive integer"), optarg);
                         else
-                                socket_timeout = atoi (optarg);
+                                socket_timeout = atoi(optarg);
                         break;
                 case '4':
                         address_family = AF_INET;
@@ -147,121 +135,104 @@ process_arguments (int argc, char **argv)
 #ifdef USE_IPV6
                         address_family = AF_INET6;
 #else
-                        usage4 (_("IPv6 support not available"));
+                        usage4(_("IPv6 support not available"));
 #endif
                         break;
-                case 'r':                                                                       /* remote version */
+                case 'r': /* remote version */
                         remote_version = optarg;
                         break;
-                case 'P':                                                                       /* remote version */
+                case 'P': /* remote version */
                         remote_protocol = optarg;
                         break;
-                case 'H':                                                                       /* host */
-                        if (!is_host (optarg))
-                                usage2 (_("Invalid hostname/address"), optarg);
+                case 'H': /* host */
+                        if (!is_host(optarg))
+                                usage2(_("Invalid hostname/address"), optarg);
                         server_name = optarg;
                         break;
-                case 'p':                                                                       /* port */
-                        if (is_intpos (optarg)) {
-                                port = atoi (optarg);
-                        }
-                        else {
-                                usage2 (_("Port number must be a positive integer"), optarg);
+                case 'p': /* port */
+                        if (is_intpos(optarg)) {
+                                port = atoi(optarg);
+                        } else {
+                                usage2(_("Port number must be a positive integer"), optarg);
                         }
                 }
         }
 
-        c = optind;
-        if (server_name == NULL && c < argc) {
-                if (is_host (argv[c])) {
-                        server_name = argv[c++];
+        option_char = optind;
+        if (server_name == NULL && option_char < argc) {
+                if (is_host(argv[option_char])) {
+                        server_name = argv[option_char++];
                 }
         }
 
-        if (port == -1 && c < argc) {
-                if (is_intpos (argv[c])) {
-                        port = atoi (argv[c++]);
-                }
-                else {
-                        print_usage ();
-                        exit (STATE_UNKNOWN);
+        if (port == -1 && option_char < argc) {
+                if (is_intpos(argv[option_char])) {
+                        port = atoi(argv[option_char++]);
+                } else {
+                        print_usage();
+                        exit(STATE_UNKNOWN);
                 }
         }
 
-        return validate_arguments ();
+        return validate_arguments();
 }
 
-int
-validate_arguments (void)
-{
+int validate_arguments(void) {
         if (server_name == NULL)
                 return ERROR;
-        if (port == -1)                                                         /* funky, but allows -p to override stray integer in args */
+        if (port == -1) /* funky, but allows -p to override stray integer in args */
                 port = SSH_DFL_PORT;
         return OK;
 }
 
-
 /************************************************************************
-*
-* Try to connect to SSH server at specified server and port
-*
-*-----------------------------------------------------------------------*/
-
-
-int
-ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol)
-{
-        int sd;
-        int result;
-        int len = 0;
-        ssize_t recv_ret = 0;
-        char *version_control_string = NULL;
-        char *buffer = NULL;
-        char *ssh_proto = NULL;
-        char *ssh_server = NULL;
-        static char *rev_no = VERSION;
-        struct timeval tv;
-        double elapsed_time;
+ *
+ * Try to connect to SSH server at specified server and port
+ *
+ *-----------------------------------------------------------------------*/
 
+int ssh_connect(char *haddr, int hport, char *remote_version, char *remote_protocol) {
+        struct timeval tv;
         gettimeofday(&tv, NULL);
 
-        result = my_tcp_connect (haddr, hport, &sd);
+        int socket;
+        int result = my_tcp_connect(haddr, hport, &socket);
 
         if (result != STATE_OK)
                 return result;
 
-        char *output = (char *) calloc (BUFF_SZ + 1, sizeof(char));
-
-        unsigned int iteration = 0;
+        char *output = (char *)calloc(BUFF_SZ + 1, sizeof(char));
+        char *buffer = NULL;
+        ssize_t recv_ret = 0;
+        char *version_control_string = NULL;
         ssize_t byte_offset = 0;
-
-        while ((version_control_string == NULL) && (recv_ret = recv(sd, output+byte_offset, BUFF_SZ - byte_offset, 0) > 0)) {
+        while ((version_control_string == NULL) && (recv_ret = recv(socket, output + byte_offset, BUFF_SZ - byte_offset, 0) > 0)) {
 
                 if (strchr(output, '\n')) { /* we've got at least one full line, start parsing*/
                         byte_offset = 0;
 
                         char *index = NULL;
-                        while ((index = strchr(output+byte_offset, '\n')) != NULL) {
+                        int len = 0;
+                        while ((index = strchr(output + byte_offset, '\n')) != NULL) {
                                 /*Partition the buffer so that this line is a separate string,
                                  * by replacing the newline with NUL*/
                                 output[(index - output)] = '\0';
                                 len = strlen(output + byte_offset);
 
-                                if ((len >= 4) && (strncmp (output+byte_offset, "SSH-", 4) == 0)) {
+                                if ((len >= 4) && (strncmp(output + byte_offset, "SSH-", 4) == 0)) {
                                         /*if the string starts with SSH-, this _should_ be a valid version control string*/
-                                                version_control_string = output+byte_offset;
-                                                break;
+                                        version_control_string = output + byte_offset;
+                                        break;
                                 }
 
                                 /*the start of the next line (if one exists) will be after the current one (+ NUL)*/
                                 byte_offset += (len + 1);
                         }
 
-                        if(version_control_string == NULL) {
+                        if (version_control_string == NULL) {
                                 /* move unconsumed data to beginning of buffer, null rest */
-                                memmove((void *)output, (void *)output+byte_offset+1, BUFF_SZ - len+1);
-                                memset(output+byte_offset+1, 0, BUFF_SZ-byte_offset+1);
+                                memmove((void *)output, (void *)(output + byte_offset + 1), BUFF_SZ - len + 1);
+                                memset(output + byte_offset + 1, 0, BUFF_SZ - byte_offset + 1);
 
                                 /*start reading from end of current line chunk on next recv*/
                                 byte_offset = strlen(output);
@@ -287,10 +258,11 @@ ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol
          * SSH-protoversion-softwareversion SP comments CR LF"
          *              - RFC 4253:4.2
          */
-        strip (version_control_string);
+        strip(version_control_string);
         if (verbose)
-                printf ("%s\n", version_control_string);
-        ssh_proto = version_control_string + 4;
+                printf("%s\n", version_control_string);
+
+        char *ssh_proto = version_control_string + 4;
 
         /*
          * We assume the protoversion is of the form Major.Minor, although
@@ -308,7 +280,7 @@ ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol
          * "1.x" (e.g., "1.5" or "1.3")."
          *              - RFC 4253:5
          */
-        ssh_server = ssh_proto + strspn (ssh_proto, "0123456789.") + 1; /* (+1 for the '-' separating protoversion from softwareversion) */
+        char *ssh_server = ssh_proto + strspn(ssh_proto, "0123456789.") + 1; /* (+1 for the '-' separating protoversion from softwareversion) */
 
         /* If there's a space in the version string, whatever's after the space is a comment
          * (which is NOT part of the server name/version)*/
@@ -318,86 +290,72 @@ ssh_connect (char *haddr, int hport, char *remote_version, char *remote_protocol
         }
         if (strlen(ssh_proto) == 0 || strlen(ssh_server) == 0) {
                 printf(_("SSH CRITICAL - Invalid protocol version control string %s\n"), version_control_string);
-                exit (STATE_CRITICAL);
+                exit(STATE_CRITICAL);
         }
-        ssh_proto[strspn (ssh_proto, "0123456789. ")] = 0;
+        ssh_proto[strspn(ssh_proto, "0123456789. ")] = 0;
 
-        xasprintf (&buffer, "SSH-%s-check_ssh_%s\r\n", ssh_proto, rev_no);
-        send (sd, buffer, strlen (buffer), MSG_DONTWAIT);
+        static char *rev_no = VERSION;
+        xasprintf(&buffer, "SSH-%s-check_ssh_%s\r\n", ssh_proto, rev_no);
+        send(socket, buffer, strlen(buffer), MSG_DONTWAIT);
         if (verbose)
-                printf ("%s\n", buffer);
+                printf("%s\n", buffer);
 
         if (remote_version && strcmp(remote_version, ssh_server)) {
-                printf
-                        (_("SSH CRITICAL - %s (protocol %s) version mismatch, expected '%s'\n"),
-                         ssh_server, ssh_proto, remote_version);
-                close(sd);
-                exit (STATE_CRITICAL);
+                printf(_("SSH CRITICAL - %s (protocol %s) version mismatch, expected '%s'\n"), ssh_server, ssh_proto, remote_version);
+                close(socket);
+                exit(STATE_CRITICAL);
         }
 
+        double elapsed_time = (double)deltime(tv) / 1.0e6;
         if (remote_protocol && strcmp(remote_protocol, ssh_proto)) {
-                printf
-                        (_("SSH CRITICAL - %s (protocol %s) protocol version mismatch, expected '%s' | %s\n"),
-                         ssh_server, ssh_proto, remote_protocol, fperfdata("time", elapsed_time, "s",
-                         false, 0, false, 0, true, 0, true, (int)socket_timeout));
-                close(sd);
-                exit (STATE_CRITICAL);
+                printf(_("SSH CRITICAL - %s (protocol %s) protocol version mismatch, expected '%s' | %s\n"), ssh_server, ssh_proto, remote_protocol,
+                           fperfdata("time", elapsed_time, "s", false, 0, false, 0, true, 0, true, (int)socket_timeout));
+                close(socket);
+                exit(STATE_CRITICAL);
         }
-        elapsed_time = (double)deltime(tv) / 1.0e6;
-
-        printf
-                (_("SSH OK - %s (protocol %s) | %s\n"),
-                 ssh_server, ssh_proto, fperfdata("time", elapsed_time, "s",
-                         false, 0, false, 0, true, 0, true, (int)socket_timeout));
-        close(sd);
-        exit (STATE_OK);
-}
-
 
+        printf(_("SSH OK - %s (protocol %s) | %s\n"), ssh_server, ssh_proto,
+                   fperfdata("time", elapsed_time, "s", false, 0, false, 0, true, 0, true, (int)socket_timeout));
+        close(socket);
+        exit(STATE_OK);
+}
 
-void
-print_help (void)
-{
+void print_help(void) {
         char *myport;
-        xasprintf (&myport, "%d", SSH_DFL_PORT);
+        xasprintf(&myport, "%d", SSH_DFL_PORT);
 
-        print_revision (progname, NP_VERSION);
+        print_revision(progname, NP_VERSION);
 
-        printf ("Copyright (c) 1999 Remi Paulmier <remi@sinfomic.fr>\n");
-        printf (COPYRIGHT, copyright, email);
+        printf("Copyright (c) 1999 Remi Paulmier <remi@sinfomic.fr>\n");
+        printf(COPYRIGHT, copyright, email);
 
-        printf ("%s\n", _("Try to connect to an SSH server at specified server and port"));
+        printf("%s\n", _("Try to connect to an SSH server at specified server and port"));
 
-        printf ("\n\n");
+        printf("\n\n");
 
-        print_usage ();
+        print_usage();
 
-        printf (UT_HELP_VRSN);
-        printf (UT_EXTRA_OPTS);
+        printf(UT_HELP_VRSN);
+        printf(UT_EXTRA_OPTS);
 
-        printf (UT_HOST_PORT, 'p', myport);
+        printf(UT_HOST_PORT, 'p', myport);
 
-        printf (UT_IPv46);
+        printf(UT_IPv46);
 
-        printf (UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
+        printf(UT_CONN_TIMEOUT, DEFAULT_SOCKET_TIMEOUT);
 
-        printf (" %s\n", "-r, --remote-version=STRING");
-        printf ("    %s\n", _("Alert if string doesn't match expected server version (ex: OpenSSH_3.9p1)"));
+        printf(" %s\n", "-r, --remote-version=STRING");
+        printf("    %s\n", _("Alert if string doesn't match expected server version (ex: OpenSSH_3.9p1)"));
 
-        printf (" %s\n", "-P, --remote-protocol=STRING");
-        printf ("    %s\n", _("Alert if protocol doesn't match expected protocol version (ex: 2.0)"));
+        printf(" %s\n", "-P, --remote-protocol=STRING");
+        printf("    %s\n", _("Alert if protocol doesn't match expected protocol version (ex: 2.0)"));
 
-        printf (UT_VERBOSE);
+        printf(UT_VERBOSE);
 
-        printf (UT_SUPPORT);
+        printf(UT_SUPPORT);
 }
 
-
-
-void
-print_usage (void)
-{
-        printf ("%s\n", _("Usage:"));
-        printf ("%s  [-4|-6] [-t <timeout>] [-r <remote version>] [-p <port>] <host>\n", progname);
+void print_usage(void) {
+        printf("%s\n", _("Usage:"));
+        printf("%s  [-4|-6] [-t <timeout>] [-r <remote version>] [-p <port>] <host>\n", progname);
 }
-