Added a safe connection cleanup procedure for when a connection goes

down while it may be attempted to be used.

GNUmakefile

@@ -131,6 +131,7 @@ libuhub_SOURCES := \
 		src/core/route.c \
 		src/core/user.c \
 		src/core/usermanager.c \
+		src/network/backend.c \
 		src/network/connection.c \
 		src/network/epoll.c \
 		src/network/network.c \

src/network/backend.c

@@ -0,0 +1,63 @@
+/*
+ * uhub - A tiny ADC p2p connection hub
+ * Copyright (C) 2007-2010, Jan Vidar Krey
+ *
+ * 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/>.
+ *
+ */
+
+#include "uhub.h"
+
+#include "network/connection.h"
+
+struct net_cleanup_handler
+{
+	size_t num;
+	size_t max;
+	struct net_connection** queue;
+};
+
+struct net_cleanup_handler* net_cleanup_initialize(size_t max)
+{
+	struct net_cleanup_handler* handler = (struct net_cleanup_handler*) hub_malloc(sizeof(struct net_cleanup_handler));
+	handler->num = 0;
+	handler->max = max;
+	handler->queue = hub_malloc_zero(sizeof(struct net_connection*) * max);
+	return handler;
+}
+
+void net_cleanup_shutdown(struct net_cleanup_handler* handler)
+{
+	hub_free(handler->queue);
+	hub_free(handler);
+}
+
+void net_cleanup_delayed_free(struct net_cleanup_handler* handler, struct net_connection* con)
+{
+	handler->queue[handler->num++] = con;
+	con->flags |= NET_CLEANUP;
+}
+
+void net_cleanup_process(struct net_cleanup_handler* handler)
+{
+	size_t n;
+	for (n = 0; n < handler->num; n++)
+	{
+		struct net_connection* con = handler->queue[n];
+		LOG_TRACE("net_cleanup_process: free: %p", con);
+		hub_free(con);
+	}
+	handler->num = 0;
+}
+

src/network/backend.h

@@ -20,6 +20,9 @@
 #ifndef HAVE_UHUB_NETWORK_BACKEND_H
 #define HAVE_UHUB_NETWORK_BACKEND_H
 
+struct net_cleanup_handler;
+struct net_connection;
+
 /**
  * Initialize the network backend.
  * Returns 1 on success, or 0 on failure.
@@ -38,4 +41,13 @@ extern int net_backend_process();
 
 extern struct timeout_queue* net_backend_get_timeout_queue();
 
+struct net_cleanup_handler* net_cleanup_initialize(size_t max);
+
+void net_cleanup_shutdown(struct net_cleanup_handler* handler);
+
+void net_cleanup_delayed_free(struct net_cleanup_handler* handler, struct net_connection* con);
+
+void net_cleanup_process(struct net_cleanup_handler* handler);
+
+
 #endif /* HAVE_UHUB_NETWORK_BACKEND_H */

src/network/common.h

@@ -1,3 +1,21 @@
+/*
+ * uhub - A tiny ADC p2p connection hub
+ * Copyright (C) 2007-2010, Jan Vidar Krey
+ *
+ * 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/>.
+ *
+ */
 
 #define NET_WANT_READ             NET_EVENT_READ
 #define NET_WANT_WRITE            NET_EVENT_WRITE
@@ -8,10 +26,8 @@
 #define NET_WANT_SSL_CONNECT      0x0080
 #define NET_WANT_SSL_X509_LOOKUP  0x0100
 
-#define NET_PROCESSING_BUSY       0x8000
+#define NET_CLEANUP               0x8000
-#define NET_CLEANUP               0x4000
+
-#define NET_INITIALIZED           0x2000
-#define NET_TIMER_ENABLED         0x1000
 
 #define NET_CON_STRUCT_BASIC \
 	int                  sd;        /** socket descriptor */ \
@@ -24,12 +40,12 @@
 	SSL*                 ssl;       /** SSL handle */ \
 	size_t               write_len; /** Length of last SSL_write(), only used if flags is NET_WANT_SSL_READ. */ \
 
-#ifdef USE_SSL
+#ifdef SSL_SUPPORT
 #define NET_CON_STRUCT_COMMON \
 	NET_CON_STRUCT_BASIC \
 	NET_CON_STRUCT_SSL
 #else
 #define NET_CON_STRUCT_COMMON \
 	NET_CON_STRUCT_BASIC
-#endif
+#endif /* SSL_SUPPORT */
 

src/network/connection.h

@@ -55,7 +55,7 @@ extern void net_con_callback(struct net_connection* con, int events);
  * that the con can safely be deleted (or set to NULL).
  * @returns 1 if the memory pointed to by con can be freed immediately, or 0 if it needs to go through the NET_EVENT_DESTROYED event.
  */
-extern int net_con_close(struct net_connection* con);
+extern void net_con_close(struct net_connection* con);
 
 /**
  * Send data

src/network/epoll.c

@@ -42,6 +42,7 @@ struct net_backend
 	struct epoll_event events[EPOLL_EVBUFFER];
 	time_t now;
 	struct timeout_queue timeout_queue;
+	struct net_cleanup_handler* cleaner;
 };
 
 static struct net_backend* g_backend = 0;
@@ -84,6 +85,7 @@ int net_backend_initialize()
 
 	g_backend->now = time(0);
 	timeout_queue_initialize(&g_backend->timeout_queue, g_backend->now, 600); /* look max 10 minutes into the future. */
+	g_backend->cleaner = net_cleanup_initialize(max);
 	return 1;
 }
 
@@ -93,6 +95,7 @@ int net_backend_initialize()
 void net_backend_shutdown()
 {
 	close(g_backend->epfd);
+	net_cleanup_shutdown(g_backend->cleaner);
 	hub_free(g_backend->conns);
 	hub_free(g_backend);
 }
@@ -119,6 +122,8 @@ int net_backend_process()
 		if (g_backend->events[n].events & EPOLLOUT) ev |= NET_EVENT_WRITE;
 		net_con_callback((struct net_connection*) con, ev);
 	}
+
+	net_cleanup_process(g_backend->cleaner);
 	return 1;
 }
 
@@ -143,7 +148,7 @@ void net_con_initialize(struct net_connection* con_, int sd, net_connection_cb c
 {
 	struct net_connection_epoll* con = (struct net_connection_epoll*) con_;
 	con->sd = sd;
-	con->flags = NET_INITIALIZED;
+	con->flags = 0;
 	con->callback = callback;
 	con->ev.events = 0;
 	con->ptr = (void*) ptr;
@@ -209,13 +214,11 @@ void net_con_update(struct net_connection* con_, int events)
 	net_con_print("MOD", con);
 }
 
-int net_con_close(struct net_connection* con_)
+void net_con_close(struct net_connection* con_)
 {
 	struct net_connection_epoll* con = (struct net_connection_epoll*) con_;
-	if (!(con->flags & NET_INITIALIZED))
+	if (con->flags & NET_CLEANUP)
-		return 0;
+		return;
-
-	con->flags &= ~NET_INITIALIZED;
 
 	if (con->sd != -1)
 	{
@@ -235,7 +238,7 @@ int net_con_close(struct net_connection* con_)
 		LOG_WARN("epoll_ctl() delete failed.");
 	}
 	net_con_print("DEL", con);
-	return 0;
+	net_cleanup_delayed_free(g_backend->cleaner, con_);
 }
 
 #endif /* USE_EPOLL */

src/network/select.c

@@ -39,6 +39,7 @@ struct net_backend
 	fd_set wfds;
 	time_t now;
 	struct timeout_queue timeout_queue;
+	struct net_cleanup_handler* cleaner;
 };
 
 static struct net_backend* g_backend = 0;
@@ -74,6 +75,7 @@ int net_backend_initialize()
 	FD_ZERO(&g_backend->wfds);
 	g_backend->now = time(0);
 	timeout_queue_initialize(&g_backend->timeout_queue, g_backend->now, 600); /* look max 10 minutes into the future. */
+	g_backend->cleaner = net_cleanup_initialize(max);
 	return 1;
 }
 
@@ -82,6 +84,7 @@ int net_backend_initialize()
  */
 void net_backend_shutdown()
 {
+	net_cleanup_shutdown(g_backend->cleaner);
 	hub_free(g_backend->conns);
 	hub_free(g_backend);
 }
@@ -130,6 +133,8 @@ int net_backend_process()
 			}
 		}
 	}
+
+	net_cleanup_process(g_backend->cleaner);
 	return 1;
 }
 
@@ -154,8 +159,7 @@ void net_con_initialize(struct net_connection* con_, int sd, net_connection_cb c
 {
 	struct net_connection_select* con = (struct net_connection_select*) con_;
 	con->sd = sd;
-	con->flags = NET_INITIALIZED;
+	con->flags = events;
-	con->flags |= events;
 	con->callback = callback;
 	con->ptr = (void*) ptr;
 
@@ -176,17 +180,14 @@ void net_con_reinitialize(struct net_connection* con, net_connection_cb callback
 
 void net_con_update(struct net_connection* con, int events)
 {
-	con->flags = NET_INITIALIZED;
+	con->flags = events;
-	con->flags |= events;
 	net_con_print("MOD", (struct net_connection_select*) con);
 }
 
-int net_con_close(struct net_connection* con)
+void net_con_close(struct net_connection* con)
 {
-	if (!(con->flags & NET_INITIALIZED))
+	if (con->flags & NET_CLEANUP)
-		return 0;
+		return;
-
-	con->flags &= ~NET_INITIALIZED;
 
 	if (con->sd != -1)
 	{
@@ -202,7 +203,7 @@ int net_con_close(struct net_connection* con)
 	}
 
 	net_con_print("DEL", (struct net_connection_select*) con);
-	return 0;
+	net_cleanup_delayed_free(g_backend->cleaner, con);
 }
 
 #endif /* USE_SELECT */