* Sockets now inherit from WeakReferenceable.

* This fixes the problem when a socket changes something with regards to its
  parent.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30000 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/net/net_socket.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007, Haiku, Inc. All Rights Reserved.
+ * Copyright 2006-2009, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef NET_SOCKET_H
@@ -38,7 +38,6 @@ typedef struct net_socket {
 	}						send, receive;
 
 	status_t				error;
-	struct net_socket		*parent;
 } net_socket;
 
 struct net_socket_module_info {
@@ -47,7 +46,7 @@ struct net_socket_module_info {
 	status_t	(*open_socket)(int family, int type, int protocol,
 					net_socket **_socket);
 	status_t	(*close)(net_socket *socket);
-	status_t	(*free)(net_socket *socket);
+	void		(*free)(net_socket *socket);
 
 	status_t	(*readv)(net_socket *socket, const iovec *vecs,
 					size_t vecCount, size_t *_length);
@@ -72,13 +71,17 @@ struct net_socket_module_info {
 					struct net_stat *stat);
 
 	// connections
+	void		(*acquire_socket)(net_socket *socket);
+	bool		(*release_socket)(net_socket *socket);
+
 	status_t	(*spawn_pending_socket)(net_socket *parent,
 					net_socket **_socket);
-	void		(*delete_socket)(net_socket *socket);
 	status_t	(*dequeue_connected)(net_socket *parent, net_socket **_socket);
 	ssize_t		(*count_connected)(net_socket *parent);
 	status_t	(*set_max_backlog)(net_socket *socket, uint32 backlog);
+	bool		(*has_parent)(net_socket *socket);
 	status_t	(*set_connected)(net_socket *socket);
+	status_t	(*set_aborted)(net_socket *socket);
 
 	// notifications
 	status_t	(*request_notification)(net_socket *socket, uint8 event,

src/add-ons/kernel/network/protocols/tcp/EndpointManager.cpp

@@ -318,7 +318,9 @@ EndpointManager::FindConnection(sockaddr* local, sockaddr* peer)
 
 	TCPEndpoint *endpoint = _LookupConnection(local, peer);
 	if (endpoint != NULL) {
-		TRACE(("TCP: Received packet corresponds to explicit endpoint %p\n", endpoint));
+		TRACE(("TCP: Received packet corresponds to explicit endpoint %p\n",
+			endpoint));
+		gSocketModule->acquire_socket(endpoint->socket);
 		return endpoint;
 	}
 
@@ -329,7 +331,9 @@ EndpointManager::FindConnection(sockaddr* local, sockaddr* peer)
 
 	endpoint = _LookupConnection(local, *wildcard);
 	if (endpoint != NULL) {
-		TRACE(("TCP: Received packet corresponds to wildcard endpoint %p\n", endpoint));
+		TRACE(("TCP: Received packet corresponds to wildcard endpoint %p\n",
+			endpoint));
+		gSocketModule->acquire_socket(endpoint->socket);
 		return endpoint;
 	}
 
@@ -339,7 +343,9 @@ EndpointManager::FindConnection(sockaddr* local, sockaddr* peer)
 
 	endpoint = _LookupConnection(*localWildcard, *wildcard);
 	if (endpoint != NULL) {
-		TRACE(("TCP: Received packet corresponds to local wildcard endpoint %p\n", endpoint));
+		TRACE(("TCP: Received packet corresponds to local wildcard endpoint "
+			"%p\n", endpoint));
+		gSocketModule->acquire_socket(endpoint->socket);
 		return endpoint;
 	}
 
@@ -564,7 +570,7 @@ void
 EndpointManager::Dump() const
 {
 	kprintf("-------- TCP Domain %p ---------\n", this);
-	kprintf("%10s %20s %20s %8s %8s %12s\n", "address", "local", "peer",
+	kprintf("%10s %21s %21s %8s %8s %12s\n", "address", "local", "peer",
 		"recv-q", "send-q", "state");
 
 	ConnectionTable::Iterator iterator = fConnectionHash.GetIterator();
@@ -576,7 +582,7 @@ EndpointManager::Dump() const
 		endpoint->LocalAddress().AsString(localBuf, sizeof(localBuf), true);
 		endpoint->PeerAddress().AsString(peerBuf, sizeof(peerBuf), true);
 
-		kprintf("%p %20s %20s %8lu %8lu %12s\n", endpoint, localBuf, peerBuf,
+		kprintf("%p %21s %21s %8lu %8lu %12s\n", endpoint, localBuf, peerBuf,
 			endpoint->fReceiveQueue.Available(), endpoint->fSendQueue.Used(),
 			name_for_state(endpoint->State()));
 	}

src/add-ons/kernel/network/protocols/tcp/TCPEndpoint.cpp

@@ -554,7 +554,7 @@ TCPEndpoint::Close()
 }
 
 
-status_t
+void
 TCPEndpoint::Free()
 {
 	TRACE("Free()");
@@ -562,17 +562,16 @@ TCPEndpoint::Free()
 	MutexLocker _(fLock);
 
 	if (fState <= SYNCHRONIZE_SENT)
-		return B_OK;
+		return;
 
 	// we are only interested in the timer, not in changing state
 	_EnterTimeWait();
 
 	fFlags |= FLAG_CLOSED;
-	if ((fFlags & FLAG_DELETE_ON_CLOSE) != 0)
+	if ((fFlags & FLAG_DELETE_ON_CLOSE) == 0) {
-		return B_OK;
-
-	return B_BUSY;
 		// we'll be freed later when the 2MSL timer expires
+		gSocketModule->acquire_socket(socket);
+	}
 }
 
 
@@ -1169,7 +1168,7 @@ TCPEndpoint::_MarkEstablished()
 	fState = ESTABLISHED;
 	T(State(this));
 
-	if (socket->parent != NULL) {
+	if (gSocketModule->has_parent(socket)) {
 		gSocketModule->set_connected(socket);
 		release_sem_etc(fAcceptSemaphore, 1, B_DO_NOT_RESCHEDULE);
 	}
@@ -1211,13 +1210,11 @@ TCPEndpoint::_Close()
 	fSendList.Signal();
 	_NotifyReader();
 
-	if (socket->parent != NULL) {
+	if (gSocketModule->has_parent(socket)) {
 		// We still have a parent - obviously, we haven't been accepted yet,
 		// so no one could ever close us.
-		// Since we can't just delete ourself here, we trigger an immediate
-		// time-wait timer.
 		_CancelConnectionTimers();
-		gStackModule->set_timer(&fTimeWaitTimer, 0);
+		gSocketModule->set_aborted(socket);
 	}
 }
 
@@ -1792,8 +1789,7 @@ TCPEndpoint::SegmentReceived(tcp_segment_header& segment, net_buffer* buffer)
 	if ((fFlags & (FLAG_CLOSED | FLAG_DELETE_ON_CLOSE))
 			== (FLAG_CLOSED | FLAG_DELETE_ON_CLOSE)) {
 		locker.Unlock();
-		gSocketModule->delete_socket(socket);
+		gSocketModule->release_socket(socket);
-			// this will also delete us
 	}
 
 	return segmentAction;
@@ -2293,7 +2289,7 @@ TCPEndpoint::_TimeWaitTimer(net_timer* timer, void* _endpoint)
 
 	locker.Unlock();
 
-	gSocketModule->delete_socket(endpoint->socket);
+	gSocketModule->release_socket(endpoint->socket);
 }
 
 

src/add-ons/kernel/network/protocols/tcp/TCPEndpoint.h

@@ -50,7 +50,7 @@ public:
 
 			status_t	Open();
 			status_t	Close();
-			status_t	Free();
+			void		Free();
 			status_t	Connect(const struct sockaddr* address);
 			status_t	Accept(struct net_socket** _acceptedSocket);
 			status_t	Bind(const sockaddr* address);

src/add-ons/kernel/network/protocols/tcp/tcp.cpp

@@ -496,7 +496,8 @@ tcp_close(net_protocol* protocol)
 status_t
 tcp_free(net_protocol* protocol)
 {
-	return ((TCPEndpoint*)protocol)->Free();
+	((TCPEndpoint*)protocol)->Free();
+	return B_OK;
 }
 
 
@@ -708,9 +709,10 @@ tcp_receive_data(net_buffer* buffer)
 
 	TCPEndpoint* endpoint = endpointManager->FindConnection(
 		buffer->destination, buffer->source);
-	if (endpoint != NULL)
+	if (endpoint != NULL) {
 		segmentAction = endpoint->SegmentReceived(segment, buffer);
-	else if ((segment.flags & TCP_FLAG_RESET) == 0)
+		gSocketModule->release_socket(endpoint->socket);
+	} else if ((segment.flags & TCP_FLAG_RESET) == 0)
 		segmentAction = DROP | RESET;
 
 	if ((segmentAction & RESET) != 0) {

src/add-ons/kernel/network/stack/net_socket.cpp

@@ -16,13 +16,15 @@
 
 #include <new>
 
-#include <AutoDeleter.h>
 #include <Drivers.h>
 #include <KernelExport.h>
 #include <Select.h>
+
+#include <AutoDeleter.h>
 #include <team.h>
 #include <util/AutoLock.h>
 #include <util/list.h>
+#include <WeakReferenceable.h>
 
 #include <fs/select_sync_pool.h>
 #include <kernel.h>
@@ -41,8 +43,15 @@
 struct net_socket_private;
 typedef DoublyLinkedList<net_socket_private> SocketList;
 
-struct net_socket_private
+struct net_socket_private : net_socket,
-		: net_socket, DoublyLinkedListLinkImpl<net_socket_private> {
+		DoublyLinkedListLinkImpl<net_socket_private>,
+		WeakReferenceable<net_socket_private> {
+	net_socket_private();
+	~net_socket_private();
+
+	void RemoveFromParent();
+
+	WeakPointer<net_socket_private>* parent;
 	team_id						owner;
 	uint32						max_backlog;
 	uint32						child_count;
@@ -56,7 +65,6 @@ struct net_socket_private
 };
 
 
-void socket_delete(net_socket* socket);
 int socket_bind(net_socket* socket, const struct sockaddr* address,
 	socklen_t addressLength);
 int socket_setsockopt(net_socket* socket, int level, int option,
@@ -67,6 +75,80 @@ static SocketList sSocketList;
 static mutex sSocketLock;
 
 
+net_socket_private::net_socket_private()
+	: WeakReferenceable<net_socket_private>(this),
+	parent(NULL),
+	owner(-1),
+	max_backlog(0),
+	child_count(0),
+	select_pool(NULL),
+	is_connected(false)
+{
+	first_protocol = NULL;
+	first_info = NULL;
+	options = 0;
+	linger = 0;
+	bound_to_device = 0;
+	error = 0;
+
+	address.ss_len = 0;
+	peer.ss_len = 0;
+
+	mutex_init(&lock, "socket");
+
+	// set defaults (may be overridden by the protocols)
+	send.buffer_size = 65535;
+	send.low_water_mark = 1;
+	send.timeout = B_INFINITE_TIMEOUT;
+	receive.buffer_size = 65535;
+	receive.low_water_mark = 1;
+	receive.timeout = B_INFINITE_TIMEOUT;
+}
+
+
+net_socket_private::~net_socket_private()
+{
+	if (parent != NULL)
+		panic("socket still has a parent!");
+
+	mutex_lock(&sSocketLock);
+	sSocketList.Remove(this);
+	mutex_unlock(&sSocketLock);
+
+	mutex_lock(&lock);
+
+	// also delete all children of this socket
+	while (net_socket_private* child = pending_children.RemoveHead()) {
+		child->RemoveFromParent();
+	}
+	while (net_socket_private* child = connected_children.RemoveHead()) {
+		child->RemoveFromParent();
+	}
+
+	put_domain_protocols(this);
+
+	mutex_unlock(&lock);
+	mutex_destroy(&lock);
+}
+
+
+void
+net_socket_private::RemoveFromParent()
+{
+	parent->RemoveReference();
+	parent = NULL;
+
+	mutex_lock(&sSocketLock);
+	sSocketList.Add(this);
+	mutex_unlock(&sSocketLock);
+
+	RemoveReference();
+}
+
+
+//	#pragma mark -
+
+
 static size_t
 compute_user_iovec_length(iovec* userVec, uint32 count)
 {
@@ -84,16 +166,6 @@ compute_user_iovec_length(iovec* userVec, uint32 count)
 }
 
 
-static void
-delete_children(SocketList& list)
-{
-	while (net_socket_private* child = list.RemoveHead()) {
-		child->parent = NULL;
-		socket_delete(child);
-	}
-}
-
-
 static status_t
 create_socket(int family, int type, int protocol, net_socket_private** _socket)
 {
@@ -101,21 +173,10 @@ create_socket(int family, int type, int protocol, net_socket_private** _socket)
 	if (socket == NULL)
 		return B_NO_MEMORY;
 
-	memset(socket, 0, sizeof(net_socket_private));
 	socket->family = family;
 	socket->type = type;
 	socket->protocol = protocol;
 
-	mutex_init(&socket->lock, "socket");
-
-	// set defaults (may be overridden by the protocols)
-	socket->send.buffer_size = 65535;
-	socket->send.low_water_mark = 1;
-	socket->send.timeout = B_INFINITE_TIMEOUT;
-	socket->receive.buffer_size = 65535;
-	socket->receive.low_water_mark = 1;
-	socket->receive.timeout = B_INFINITE_TIMEOUT;
-
 	status_t status = get_domain_protocols(socket);
 	if (status < B_OK) {
 		mutex_destroy(&socket->lock);
@@ -316,7 +377,7 @@ socket_open(int family, int type, int protocol, net_socket** _socket)
 
 	status = socket->first_info->open(socket->first_protocol);
 	if (status < B_OK) {
-		socket_delete(socket);
+		delete socket;
 		return status;
 	}
 
@@ -339,15 +400,12 @@ socket_close(net_socket* _socket)
 }
 
 
-status_t
+void
-socket_free(net_socket* socket)
+socket_free(net_socket* _socket)
 {
-	status_t status = socket->first_info->free(socket->first_protocol);
+	net_socket_private* socket = (net_socket_private*)_socket;
-	if (status == B_BUSY)
+	socket->first_info->free(socket->first_protocol);
-		return B_OK;
+	socket->RemoveReference();
-
-	socket_delete(socket);
-	return B_OK;
 }
 
 
@@ -532,6 +590,22 @@ socket_get_next_stat(uint32* _cookie, int family, struct net_stat* stat)
 //	#pragma mark - connections
 
 
+void
+socket_acquire(net_socket* _socket)
+{
+	net_socket_private* socket = (net_socket_private*)_socket;
+	socket->AddReference();
+}
+
+
+bool
+socket_release(net_socket* _socket)
+{
+	net_socket_private* socket = (net_socket_private*)_socket;
+	return socket->RemoveReference();
+}
+
+
 status_t
 socket_spawn_pending(net_socket* _parent, net_socket** _socket)
 {
@@ -562,7 +636,7 @@ socket_spawn_pending(net_socket* _parent, net_socket** _socket)
 
 	// add to the parent's list of pending connections
 	parent->pending_children.Add(socket);
-	socket->parent = parent;
+	socket->parent = parent->GetWeakPointer();
 	parent->child_count++;
 
 	*_socket = socket;
@@ -570,42 +644,9 @@ socket_spawn_pending(net_socket* _parent, net_socket** _socket)
 }
 
 
-void
+/*!	Dequeues a connected child from a parent socket.
-socket_delete(net_socket* _socket)
+	It also returns a reference with the child socket.
-{
+*/
-	net_socket_private* socket = (net_socket_private*)_socket;
-	net_socket_private* parent = (net_socket_private*)socket->parent;
-
-	if (parent != NULL) {
-		// The socket still has a parent
-		// TODO: we need to make sure our parent isn't deleted right now,
-		//   or in the process of deleting its children...
-		MutexLocker _(parent->lock);
-
-		if (socket->is_connected)
-			parent->connected_children.Remove(socket);
-		else
-			parent->pending_children.Remove(socket);
-
-		parent->child_count--;
-		socket->parent = NULL;
-	}
-
-	mutex_lock(&sSocketLock);
-	sSocketList.Remove(socket);
-	mutex_unlock(&sSocketLock);
-
-	// also delete all children of this socket
-	delete_children(socket->pending_children);
-	delete_children(socket->connected_children);
-
-	put_domain_protocols(socket);
-
-	mutex_destroy(&socket->lock);
-	delete socket;
-}
-
-
 status_t
 socket_dequeue_connected(net_socket* _parent, net_socket** _socket)
 {
@@ -615,7 +656,8 @@ socket_dequeue_connected(net_socket* _parent, net_socket** _socket)
 
 	net_socket_private* socket = parent->connected_children.RemoveHead();
 	if (socket != NULL) {
-		socket->parent = NULL;
+		socket->AddReference();
+		socket->RemoveFromParent();
 		parent->child_count--;
 		*_socket = socket;
 	}
@@ -625,10 +667,6 @@ socket_dequeue_connected(net_socket* _parent, net_socket** _socket)
 	if (socket == NULL)
 		return B_ENTRY_NOT_FOUND;
 
-	mutex_lock(&sSocketLock);
-	sSocketList.Add(socket);
-	mutex_unlock(&sSocketLock);
-
 	return B_OK;
 }
 
@@ -659,13 +697,12 @@ socket_set_max_backlog(net_socket* _socket, uint32 backlog)
 	net_socket_private* child;
 	while (socket->child_count > backlog
 		&& (child = socket->pending_children.RemoveTail()) != NULL) {
-		child->parent = NULL;
+		child->RemoveFromParent();
 		socket->child_count--;
 	}
 	while (socket->child_count > backlog
 		&& (child = socket->connected_children.RemoveTail()) != NULL) {
-		child->parent = NULL;
+		child->RemoveFromParent();
-		socket_delete(child);
 		socket->child_count--;
 	}
 
@@ -674,21 +711,34 @@ socket_set_max_backlog(net_socket* _socket, uint32 backlog)
 }
 
 
+/*!	Returns whether or not this socket has a parent. The parent might not be
+	valid anymore, though.
+*/
+bool
+socket_has_parent(net_socket* _socket)
+{
+	net_socket_private* socket = (net_socket_private*)_socket;
+	return socket->parent != NULL;
+}
+
+
 /*!	The socket has been connected. It will be moved to the connected queue
 	of its parent socket.
 */
 status_t
-socket_connected(net_socket* socket)
+socket_connected(net_socket* _socket)
 {
-	net_socket_private* parent = (net_socket_private*)socket->parent;
+	net_socket_private* socket = (net_socket_private*)_socket;
+
+	WeakReference<net_socket_private> parent = socket->parent;
 	if (parent == NULL)
 		return B_BAD_VALUE;
 
-	MutexLocker _(&parent->lock);
+	MutexLocker _(parent->lock);
 
-	parent->pending_children.Remove((net_socket_private*)socket);
+	parent->pending_children.Remove(socket);
-	parent->connected_children.Add((net_socket_private*)socket);
+	parent->connected_children.Add(socket);
-	((net_socket_private*)socket)->is_connected = true;
+	socket->is_connected = true;
 
 	// notify parent
 	if (parent->select_pool)
@@ -698,6 +748,32 @@ socket_connected(net_socket* socket)
 }
 
 
+/*!	The socket has been aborted. Steals the parent's reference, and releases
+	it.
+*/
+status_t
+socket_aborted(net_socket* _socket)
+{
+	net_socket_private* socket = (net_socket_private*)_socket;
+
+	WeakReference<net_socket_private> parent = socket->parent;
+	if (parent == NULL)
+		return B_BAD_VALUE;
+
+	MutexLocker _(parent->lock);
+
+	if (socket->is_connected)
+		parent->connected_children.Remove(socket);
+	else
+		parent->pending_children.Remove(socket);
+
+	parent->child_count--;
+	socket->RemoveFromParent();
+
+	return B_OK;
+}
+
+
 //	#pragma mark - notifications
 
 
@@ -1551,12 +1627,15 @@ net_socket_module_info gNetSocketModule = {
 	socket_get_next_stat,
 
 	// connections
+	socket_acquire,
+	socket_release,
 	socket_spawn_pending,
-	socket_delete,
 	socket_dequeue_connected,
 	socket_count_connected,
 	socket_set_max_backlog,
+	socket_has_parent,
 	socket_connected,
+	socket_aborted,
 
 	// notifications
 	socket_request_notification,

src/add-ons/kernel/network/stack/stack_interface.cpp

@@ -27,7 +27,8 @@ stack_interface_close(net_socket* socket)
 static status_t
 stack_interface_free(net_socket* socket)
 {
-	return gNetSocketModule.free(socket);
+	gNetSocketModule.free(socket);
+	return B_OK;
 }