Add option to output response body as performance data

Added option -o/--output-body-as-perfdata to append the http response body
to the output line. This will only happen for responses that are of state "OK".

Imagine the requested webserver responds with 200 OK and the text:

|'first variable'=42|'second variable'=111

This text will be appended to the plugin output, and is treated as regular
performance data.

The switch -o or --output-body-as-perfdata enables this feature.

plugins/check_http.c

@@ -120,6 +120,7 @@ int use_ssl = FALSE;
 int use_sni = FALSE;
 int verbose = FALSE;
 int show_extended_perfdata = FALSE;
+int show_output_body_as_perfdata = FALSE;
 int show_url = FALSE;
 int sd;
 int min_page_len = 0;
@@ -266,6 +267,7 @@ process_arguments (int argc, char **argv)
         {"use-ipv4", no_argument, 0, '4'},
         {"use-ipv6", no_argument, 0, '6'},
         {"extended-perfdata", no_argument, 0, 'E'},
+        {"output-body-as-perfdata", no_argument, 0, 'o'},
         {"show-url", no_argument, 0, 'U'},
         {0, 0, 0, 0}
     };
@@ -287,7 +289,7 @@ process_arguments (int argc, char **argv)
     }
 
     while (1) {
-        c = getopt_long (argc, argv, "Vvh46t:c:w:A:k:H:P:j:T:I:a:b:d:e:p:s:R:r:u:f:C:J:K:nlLS::m:M:NEU", longopts, &option);
+        c = getopt_long (argc, argv, "Vvh46t:c:w:A:k:H:P:j:T:I:a:b:d:e:p:s:R:r:u:f:C:J:K:nlLS::m:M:NEoU", longopts, &option);
         if (c == -1 || c == EOF)
             break;
 
@@ -567,6 +569,9 @@ enable_ssl:
         case 'E': /* show extended perfdata */
             show_extended_perfdata = TRUE;
             break;
+        case 'o': /* output response body as perfdata */
+            show_output_body_as_perfdata = TRUE;
+            break;
         case 'U': /* show checked url in output msg */
           show_url = TRUE;
           break;
@@ -1503,7 +1508,7 @@ check_http (void)
     /* check elapsed time */
     if (show_extended_perfdata) {
         xasprintf (&msg,
-                   _("%s - %d bytes in %.3f second response time %s|%s %s %s %s %s %s %s"),
+                   _("%s - %d bytes in %.3f second response time %s|%s %s %s %s %s %s %s%s"),
                    msg, page_len, elapsed_time,
                    (display_html ? "</A>" : ""),
                    perfd_time (elapsed_time),
@@ -1512,15 +1517,17 @@ check_http (void)
                    use_ssl == TRUE ? perfd_time_ssl (elapsed_time_ssl) : "",
                    perfd_time_headers (elapsed_time_headers),
                    perfd_time_firstbyte (elapsed_time_firstbyte),
-                   perfd_time_transfer (elapsed_time_transfer));
+                   perfd_time_transfer (elapsed_time_transfer),
+                   (result == STATE_OK && show_output_body_as_perfdata ? page : ""));
     }
     else {
         xasprintf (&msg,
-                   _("%s - %d bytes in %.3f second response time %s|%s %s"),
+                   _("%s - %d bytes in %.3f second response time %s|%s %s%s"),
                    msg, page_len, elapsed_time,
                    (display_html ? "</A>" : ""),
                    perfd_time (elapsed_time),
-                   perfd_size (page_len));
+                   perfd_size (page_len),
+                   (result == STATE_OK && show_output_body_as_perfdata ? page : ""));
     }
 
     result = max_state_alt(get_status(elapsed_time, thlds), result);
@@ -1865,6 +1872,8 @@ print_help (void)
     printf ("    %s\n", _("Any other tags to be sent in http header. Use multiple times for additional headers"));
     printf (" %s\n", "-E, --extended-perfdata");
     printf ("    %s\n", _("Print additional performance data"));
+    printf (" %s\n", "-o, --output-body-as-perfdata");
+    printf ("    %s\n", _("Output response body as performance data on succes"));
     printf (" %s\n", "-U, --show-url");
     printf ("    %s\n", _("Print URL in msg output in plain text"));
     printf (" %s\n", "-L, --link");