* Actually implemented the SO_BINDTODEVICE socket option I added some time ago.

* This makes it possible to select a specific device, even if no interface
  has been configured for it yet. To make it work, each interface now has a
  private direct route which will be returned if a socket is bound to a device.
* This will be used for example in DHCP to make it work when more than one
  adapter is attached.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27983 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/net/net_socket.h

@@ -29,6 +29,7 @@ typedef struct net_socket {
 
 	int						options;
 	int						linger;
+	int						bound_to_device;
 
 	struct {
 		uint32		buffer_size;

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

@@ -219,7 +219,7 @@ datalink_control_interface(net_domain_private *domain, int32 option,
 			if (interface)
 				strlcpy(request.ifr_name, interface->name, IF_NAMESIZE);
 			else
-			status = B_BAD_VALUE; // TODO should be ENXIO?
+				status = B_BAD_VALUE; // TODO: should be ENXIO?
 			break;
 	}
 
@@ -386,7 +386,12 @@ datalink_send_datagram(net_protocol *protocol, net_domain *domain,
 		domain = protocol->module->get_domain(protocol);
 
 	net_route *route = NULL;
-	status_t status = get_buffer_route(domain, buffer, &route);
+	status_t status;
+	if (protocol->socket->bound_to_device > 0) {
+		status = get_device_route(domain, protocol->socket->bound_to_device,
+			&route);
+	} else
+		status = get_buffer_route(domain, buffer, &route);
 	if (status < B_OK)
 		return status;
 

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

@@ -258,6 +258,16 @@ create_interface(net_domain *domain, const char *name, const char *baseName,
 	interface->metric = 0;
 	interface->device_interface = grab_device_interface(deviceInterface);
 
+	// setup direct route for bound devices
+	interface->direct_route.destination = NULL;
+	interface->direct_route.mask = NULL;
+	interface->direct_route.gateway = NULL;
+	interface->direct_route.flags = 0;
+	interface->direct_route.mtu = 0;
+	interface->direct_route.interface = interface;
+	interface->direct_route.ref_count = 1;
+		// make sure this doesn't get deleted accidently
+
 	status_t status = get_domain_datalink_protocols(interface);
 	if (status < B_OK) {
 		delete interface;

src/add-ons/kernel/network/stack/interfaces.h

@@ -50,6 +50,7 @@ typedef DoublyLinkedList<net_device_interface> DeviceInterfaceList;
 struct net_interface_private : net_interface {
 	char				base_name[IF_NAMESIZE];
 	net_device_interface *device_interface;
+	net_route_private	direct_route;
 };
 
 

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

@@ -1326,6 +1326,21 @@ socket_set_option(net_socket *socket, int level, int option, const void *value,
 				socket->options &= ~option;
 			return B_OK;
 
+		case SO_BINDTODEVICE:
+		{
+			if (length != sizeof(int32))
+				return B_BAD_VALUE;
+
+			int index = *(const int32 *)value;
+			if (index < 0)
+				return B_BAD_VALUE;
+
+			// TODO: we might want to check if the device exists at all
+			// (although it doesn't really harm when we don't)
+			socket->bound_to_device = index;
+			return B_OK;
+		}
+
 		default:
 			break;
 	}

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

@@ -8,6 +8,7 @@
 
 
 #include "domains.h"
+#include "interfaces.h"
 #include "routes.h"
 #include "stack_private.h"
 #include "utility.h"
@@ -607,6 +608,32 @@ get_route(struct net_domain *_domain, const struct sockaddr *address)
 }
 
 
+status_t
+get_device_route(struct net_domain *_domain, uint32 index, net_route **_route)
+{
+	net_domain_private *domain = (net_domain_private *)_domain;
+
+	MutexLocker _(domain->lock);
+
+	net_interface_private *interface = NULL;
+
+	while (true) {
+		interface = (net_interface_private *)list_get_next_item(
+			&domain->interfaces, interface);
+		if (interface == NULL)
+			break;
+
+		if (interface->device->index == index) {
+			atomic_add(&interface->direct_route.ref_count, 1);
+			*_route = &interface->direct_route;
+			return B_OK;
+		}
+	}
+
+	return ENETUNREACH;
+}
+
+
 status_t
 get_buffer_route(net_domain *_domain, net_buffer *buffer, net_route **_route)
 {

src/add-ons/kernel/network/stack/routes.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006-2007, Haiku, Inc. All Rights Reserved.
+ * Copyright 2006-2008, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -42,6 +42,8 @@ status_t get_route_information(struct net_domain *domain, void *buffer,
 void invalidate_routes(net_domain *, net_interface *);
 struct net_route *get_route(struct net_domain *domain,
 				const struct sockaddr *address);
+status_t get_device_route(struct net_domain *domain, uint32 index,
+				struct net_route **_route);
 status_t get_buffer_route(struct net_domain *domain,
 				struct net_buffer *buffer, struct net_route **_route);
 void put_route(struct net_domain *domain, struct net_route *route);