(parse_unparsed): Return immediately if the session became blocked by DNS.

(dns_resolution): Schedule an idle check, as a client may have
	become unblocked.  Don't call isc_enable() here.  Instead, add
	the session to the run-queue.  There may be pending input in
	the input buffer.  Handle ADNS errors.
(login_request): Check the return value of isc_resolve_remote().
(read_from_connection): Return if the session is blocked by DNS.

src/server/connections.c

 /*
- * $Id: connections.c,v 0.115 2003/08/05 09:51:36 ceder Exp $
+ * $Id: connections.c,v 0.116 2003/08/06 06:59:13 ceder Exp $
  * Copyright (C) 1991-2002  Lysator Academic Computer Association.
  *
  * This file is part of the LysKOM server.
@@ -49,6 +49,7 @@
 #include <assert.h>
 #include <netdb.h>
 
+#include "adns.h"
 #include "oop.h"
 
 #include "unused.h"
@@ -136,6 +137,9 @@ static isc_stale_output_cb idle_cb;
 static Connection *queue_first = NULL;
 static Connection *queue_last = NULL;
 
+static void busy(void);
+
+
 static void
 queue_add(Connection *c)
 {
@@ -438,6 +442,8 @@ parse_unparsed(Connection *client)
     case 0 :
 	/* Parse message. If message is complete call function and reply. */
 	parse_packet(client);
+	if (client->blocked_by_dns)
+	    return TRUE;
 	update_stat(STAT_REQUESTS, 1);
 	status = call_function(client, &result);
 	update_stat(STAT_REQUESTS, -1);
@@ -684,6 +690,8 @@ dns_resolution(struct isc_scb *scb,
     Connection *conn;
     char *hostname = NULL;
 
+    busy();
+
     update_stat(STAT_DNS_QUEUE, -1);
 
     conn = scb->udg;
@@ -691,10 +699,9 @@ dns_resolution(struct isc_scb *scb,
     conn->dns_done = TRUE;
     if (conn->blocked_by_dns)
     {
-	if (isc_enable(scb) < 0)
-	    restart_kom("Failed to enble session after DNS resolution.\n");
-
 	conn->blocked_by_dns = FALSE;
+	if (!conn->on_queue)
+	    queue_add(conn);
     }
 
     if (res == isc_resolve_aborted)
@@ -723,6 +730,14 @@ dns_resolution(struct isc_scb *scb,
 		    errcode, hostname);
     }
 
+    if (res == isc_resolve_adns_error)
+    {
+	if (hostname == NULL)
+	    hostname = s_crea_c_str(scb->remote);
+
+	kom_log("Error looking up %s: %s\n", hostname, adns_strerror(errcode));
+    }
+
     if (diff > param.dns_log_threshold)
     {
 	if (hostname == NULL)
@@ -808,11 +823,8 @@ login_request(struct isc_scb *session)
     remote_ip = s_crea_c_str(cp->remote_ip);
 
     /* Initiate DNS lookup. */
-    if (param.use_dns)
-    {
+    if (param.use_dns && isc_resolve_remote(session, dns_resolution) == 0)
 	update_stat(STAT_DNS_QUEUE, 1);
-	isc_resolve_remote(session, dns_resolution);
-    }
     else
 	s_strcpy(&session->remote, cp->remote_ip);
 
@@ -879,18 +891,18 @@ read_from_connection(Connection *conn)
     adjust_penalty(conn);
 
     while (!would_block && !go_and_die && conn->penalty < param.max_penalty
-	   && !conn->kill_pending)
+	   && !conn->kill_pending && !conn->blocked_by_dns)
     {
 	pre = s_strlen(conn->unparsed) - conn->first_to_parse;
 	while (conn->more_to_parse
 	       && !go_and_die && conn->penalty < param.max_penalty
-	       && !conn->kill_pending)
+	       && !conn->kill_pending && !conn->blocked_by_dns)
 	    need_flush |= parse_unparsed(conn);
 	update_stat(STAT_RECV_QUEUE,
 		    s_strlen(conn->unparsed) - conn->first_to_parse - pre);
 
 	if (go_and_die || conn->penalty >= param.max_penalty
-	    || conn->kill_pending)
+	    || conn->kill_pending || conn->blocked_by_dns)
 	    break;
 
 	if (!conn->more_to_parse)
@@ -935,7 +947,7 @@ read_from_connection(Connection *conn)
 	restart_kom("parse_unparsed: s_trim_left\n");
     conn->first_to_parse = 0;
 
-    if (conn->penalty >= param.max_penalty)
+    if (conn->penalty >= param.max_penalty && !conn->blocked_by_dns)
     {
 	/* isc_disable() will fail if we have received EPIPE on
 	   this socket.  In that case will soon close it, since
@@ -1031,6 +1043,19 @@ saver_callback(oop_source *source,
 }
 
 
+static void
+busy(void)
+{
+    /* Something arrived, so we are busy.  */
+    if (is_idle)
+    {
+	is_idle = FALSE;
+	enable_idle_check();
+    }
+	
+    work_done = TRUE;
+}
+
 static void *
 data_available_callback(oop_source *source,
 			int fd,
@@ -1044,15 +1069,7 @@ data_available_callback(oop_source *source,
     assert(isc_getoopsource(conn->isc_session) == source);
     assert(conn->on_queue == FALSE);
 
-    /* Something arrived, so we are busy.  */
-    if (is_idle)
-    {
-	is_idle = FALSE;
-	enable_idle_check();
-    }
-	
-    work_done = TRUE;
-
+    busy();
     set_time();
     read_from_connection(conn);