Revert my previous change to "-S/--skip" in favour of the two options

"-E/--skip-stderr" and "-S/--skip-stdout".  Both of them support
omitting the number of lines to skip, in which case all output on the
respective file descriptor is skipped.  "--skip" is kept as an alias for
"--skip-stdout" for backwards compatibility with recent releases.

Also, print a message if no (non-skipped) stdout/stderr output is
available.  This fixes a segfault if the remote command prints no
output.


git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1692 f882894a-f735-0410-b71e-b25c423dba1c

1 files changed, 45 insertions, 20 deletions

diff --git a/plugins/check_by_ssh.c b/plugins/check_by_ssh.c
index 65eee3c5..6855ebc0 100644
--- a/plugins/check_by_ssh.c
+++ b/plugins/check_by_ssh.c
@@ -48,7 +48,8 @@ void print_usage (void);
 
 unsigned int commands = 0;
 unsigned int services = 0;
-unsigned int skip = 0;
+int skip_stdout = 0;
+int skip_stderr = 0;
 char *remotecmd = NULL;
 char *comm = NULL;
 char *hostname = NULL;
@@ -92,18 +93,27 @@ main (int argc, char **argv)
                 printf ("%s\n", comm);
 
         result = np_runcmd(comm, &chld_out, &chld_err, 0);
+
+        if (skip_stdout == -1) /* --skip-stdout specified without argument */
+                skip_stdout = chld_out.lines;
+        if (skip_stderr == -1) /* --skip-stderr specified without argument */
+                skip_stderr = chld_err.lines;
+
         /* UNKNOWN if (non-skipped) output found on stderr */
-        if((signed)chld_err.lines - (signed)skip > 0) {
-                printf(_("Remote command execution failed: %s\n"),
-                       skip < chld_err.lines ? chld_err.line[skip] : chld_err.buf);
+        if(chld_err.lines > skip_stderr) {
+                printf (_("Remote command execution failed: %s\n"),
+                        chld_err.line[skip_stderr]);
                 return STATE_UNKNOWN;
         }
-        skip -= chld_err.lines;
 
         /* this is simple if we're not supposed to be passive.
          * Wrap up quickly and keep the tricks below */
         if(!passive) {
-                printf ("%s\n", skip < chld_out.lines ? chld_out.line[skip] : chld_out.buf);
+                if (chld_out.lines > skip_stdout)
+                        puts (chld_out.line[skip_stdout]);
+                else
+                        printf (_("%s - check_by_ssh: Remote command '%s' returned status %d\n"),
+                                state_text(result), remotecmd, result);
                 return result;  /* return error status from remote command */
         }
 
@@ -120,7 +130,7 @@ main (int argc, char **argv)
 
         local_time = time (NULL);
         commands = 0;
-        for(i = skip; chld_out.line[i]; i++) {
+        for(i = skip_stdout; i < chld_out.lines; i++) {
                 status_text = strstr (chld_out.line[i], "STATUS CODE: ");
                 if (status_text == NULL) {
                         printf ("%s", chld_out.line[i]);
@@ -162,7 +172,9 @@ process_arguments (int argc, char **argv)
                 {"user", required_argument, 0, 'u'},
                 {"logname", required_argument, 0, 'l'},
                 {"command", required_argument, 0, 'C'},
-                {"skip", required_argument, 0, 'S'},
+                {"skip", optional_argument, 0, 'S'}, /* backwards compatibility */
+                {"skip-stdout", optional_argument, 0, 'S'},
+                {"skip-stderr", optional_argument, 0, 'E'},
                 {"proto1", no_argument, 0, '1'},
                 {"proto2", no_argument, 0, '2'},
                 {"use-ipv4", no_argument, 0, '4'},
@@ -180,7 +192,7 @@ process_arguments (int argc, char **argv)
                         strcpy (argv[c], "-t");
 
         while (1) {
-                c = getopt_long (argc, argv, "Vvh1246fqt:H:O:p:i:u:l:C:S:n:s:o:", longopts,
+                c = getopt_long (argc, argv, "Vvh1246fqt:H:O:p:i:u:l:C:S::E::n:s:o:", longopts,
                                  &option);
 
                 if (c == -1 || c == EOF)
@@ -250,11 +262,21 @@ process_arguments (int argc, char **argv)
                                 asprintf (&remotecmd, "%s;echo STATUS CODE: $?;", remotecmd);
                         asprintf (&remotecmd, "%s%s", remotecmd, optarg);
                         break;
-                case 'S':                                                                       /* Skip n lines in the output to ignore system banner */
-                        if (!is_integer (optarg))
-                                usage_va(_("skip lines must be an integer"));
+                case 'S':                                                                       /* skip n (or all) lines on stdout */
+                        if (optarg == NULL)
+                                skip_stdout = -1; /* skip all output on stdout */
+                        else if (!is_integer (optarg))
+                                usage_va(_("skip-stdout argument must be an integer"));
+                        else
+                                skip_stdout = atoi (optarg);
+                        break;
+                case 'E':                                                                       /* skip n (or all) lines on stderr */
+                        if (optarg == NULL)
+                                skip_stderr = -1; /* skip all output on stderr */
+                        else if (!is_integer (optarg))
+                                usage_va(_("skip-stderr argument must be an integer"));
                         else
-                                skip = atoi (optarg);
+                                skip_stderr = atoi (optarg);
                         break;
                 case 'o':                                                                       /* Extra options for the ssh command */
                         asprintf (&comm, "%s -%c '%s'", comm, c, optarg);
@@ -334,13 +356,15 @@ print_help (void)
         printf (_(UT_IPv46));
 
   printf (" %s\n", "-1, --proto1");
-  printf ("    %s\n", _("tell ssh to use Protocol 1"));
+  printf ("    %s\n", _("tell ssh to use Protocol 1 [optional]"));
   printf (" %s\n", "-2, --proto2");
-  printf ("    %s\n", _("tell ssh to use Protocol 2"));
-  printf (" %s\n", "-S, --skip=n");
-  printf ("    %s\n", _("Ignore first n lines on STDERR (to suppress a logon banner)"));
+  printf ("    %s\n", _("tell ssh to use Protocol 2 [optional]"));
+  printf (" %s\n", "-S, --skip-stdout[=n]");
+  printf ("    %s\n", _("Ignore all or (if specified) first n lines on STDOUT [optional]"));
+  printf (" %s\n", "-E, --skip-stderr[=n]");
+  printf ("    %s\n", _("Ignore all or (if specified) first n lines on STDERR [optional]"));
   printf (" %s\n", "-f");
-  printf ("    %s\n", _("tells ssh to fork rather than create a tty"));
+  printf ("    %s\n", _("tells ssh to fork rather than create a tty [optional]"));
   printf (" %s\n","-C, --command='COMMAND STRING'");
   printf ("    %s\n", _("command to execute on the remote machine"));
   printf (" %s\n","-l, --logname=USERNAME");
@@ -385,7 +409,8 @@ print_usage (void)
 {
         printf (_("Usage:"));
         printf (" %s -H <host> -C <command> [-fq] [-1|-2] [-4|-6]\n"
-                "       [-S lines] [-t timeout] [-i identity] [-l user] [-n name]\n"
-                "       [-s servicelist] [-O outputfile] [-p port] [-o ssh-option]\n",
+                "       [-S [lines]] [-E [lines]] [-t timeout] [-i identity]\n"
+                "       [-l user] [-n name] [-s servicelist] [-O outputfile]\n"
+                "       [-p port] [-o ssh-option]\n",
                 progname);
 }