X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=loadcfg.c;h=dbed0a3807092cfc056f9f2500dd060be66b04fb;hp=9b39f54c9cf228cb0fe118899b974a40b1f57b85;hb=a473a2a85dbf5325b270a906e85785ba4b032503;hpb=d718332b42f884d9c3c2fd0cfa9b83f4973c6971

diff --git a/loadcfg.c b/loadcfg.c
index 9b39f54c..dbed0a38 100644
--- a/loadcfg.c
+++ b/loadcfg.c
@@ -1460,13 +1460,41 @@ struct configuration_spec * load_config(void)
          {
             int max_client_connections = parse_numeric_value(cmd, arg);
 
+#if !defined(_WIN32) && !defined(HAVE_POLL)
+            /*
+             * Reject values below 1 for obvious reasons and values above
+             * FD_SETSIZE/2 because Privoxy needs two sockets to serve
+             * client connections that need forwarding.
+             *
+             * We ignore the fact that the first three file descriptors
+             * are usually set to /dev/null, one is used for logging
+             * and yet another file descriptor is required to load
+             * config files.
+             */
+            if ((max_client_connections < 1) || (FD_SETSIZE/2 < max_client_connections))
+            {
+               log_error(LOG_LEVEL_FATAL, "max-client-connections value %d"
+                  " is invalid. Value needs to be above 1 and below %d"
+                  " (FD_SETSIZE/2).", max_client_connections, FD_SETSIZE/2);
+            }
+#else
+            /*
+             * The Windows libc uses FD_SETSIZE for an array used
+             * by select(), but has no problems with file descriptors
+             * above the limit as long as no more than FD_SETSIZE are
+             * passed to select().
+             * https://msdn.microsoft.com/en-us/library/windows/desktop/ms739169%28v=vs.85%29.aspx
+             *
+             * On platforms were we use poll() we don't have to enforce
+             * an upper connection limit either.
+             */
             if (max_client_connections < 1)
             {
                log_error(LOG_LEVEL_FATAL, "max-client-connections value"
                   " has to be a number above 1. %d is invalid.",
                   max_client_connections);
             }
-
+#endif
             config->max_client_connections = max_client_connections;
             break;
          }