SIOCGIFCONF will now also report the size of the written buffer in ifconf.ifc_len

to cover the case the list of interfaces changed since SIOCGIFCOUNT was called.
Patch by Hugo Santos.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20491 a95241bf-73f2-0310-859d-f6bbb57e9c96

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

@@ -280,7 +280,12 @@ datalink_control(net_domain *_domain, int32 option, void *value,
 			if (user_memcpy(&config, value, sizeof(struct ifconf)) < B_OK)
 				return B_BAD_ADDRESS;
 
-			return list_domain_interfaces(config.ifc_buf, config.ifc_len);
+			status_t result = list_domain_interfaces(config.ifc_buf,
+				(size_t *)&config.ifc_len);
+			if (result != B_OK)
+				return result;
+
+			return user_memcpy(value, &config, sizeof(struct ifconf));
 		}
 
 		case SIOCGRTSIZE:

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006, Haiku, Inc. All Rights Reserved.
+ * Copyright 2006-2007, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -99,12 +99,13 @@ count_domain_interfaces()
 	returned.
 */
 status_t
-list_domain_interfaces(void *buffer, size_t size)
+list_domain_interfaces(void *buffer, size_t *_bufferSize)
 {
 	BenaphoreLocker locker(sDomainLock);
 
+	uint8 *current = (uint8 *)buffer;
+	const uint8 *bufferEnd = current + (*_bufferSize);
 	net_domain_private *domain = NULL;
-	size_t spaceLeft = size;
 
 	while (true) {
 		domain = (net_domain_private *)list_get_next_item(&sDomains, domain);
@@ -118,8 +119,8 @@ list_domain_interfaces(void *buffer, size_t size)
 			if (interface == NULL)
 				break;
 
-			size = IF_NAMESIZE + (interface->address ? interface->address->sa_len : 2);
-			if (spaceLeft < size)
+			size_t size = IF_NAMESIZE + (interface->address ? interface->address->sa_len : 2);
+			if ((current + size) > bufferEnd)
 				return ENOBUFS;
 
 			ifreq request;
@@ -132,14 +133,14 @@ list_domain_interfaces(void *buffer, size_t size)
 				request.ifr_addr.sa_family = AF_UNSPEC;
 			}
 
-			if (user_memcpy(buffer, &request, size) < B_OK)
+			if (user_memcpy(current, &request, size) < B_OK)
 				return B_BAD_ADDRESS;
 
-			buffer = (void *)((addr_t)buffer + size);
-			spaceLeft -= size;
+			current += size;
 		}
 	}
 
+	*_bufferSize = current - (uint8 *)buffer;
 	return B_OK;
 }
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006, Haiku, Inc. All Rights Reserved.
+ * Copyright 2006-2007, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -30,7 +30,7 @@ status_t init_domains();
 status_t uninit_domains();
 
 uint32 count_domain_interfaces();
-status_t list_domain_interfaces(void *buffer, size_t size);
+status_t list_domain_interfaces(void *buffer, size_t *_bufferSize);
 status_t add_interface_to_domain(net_domain *domain, struct ifreq& request);
 status_t remove_interface_from_domain(net_interface *interface);
 

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

@@ -258,12 +258,13 @@ count_device_interfaces()
 	returned.
 */
 status_t
-list_device_interfaces(void *buffer, size_t size)
+list_device_interfaces(void *buffer, size_t *_bufferSize)
 {
 	BenaphoreLocker locker(sInterfaceLock);
 
+	uint8 *current = (uint8 *)buffer;
+	const uint8 *bufferEnd = current + (*_bufferSize);
 	net_device_interface *interface = NULL;
-	size_t spaceLeft = size;
 
 	while (true) {
 		interface = (net_device_interface *)list_get_next_item(&sInterfaces,
@@ -275,17 +276,17 @@ list_device_interfaces(void *buffer, size_t size)
 		strlcpy(request.ifr_name, interface->name, IF_NAMESIZE);
 		get_device_interface_address(interface, &request.ifr_addr);
 
-		size = IF_NAMESIZE + request.ifr_addr.sa_len;
-		if (spaceLeft < size)
+		size_t size = IF_NAMESIZE + request.ifr_addr.sa_len;
+		if ((current + size) > bufferEnd)
 			return ENOBUFS;
 
-		if (user_memcpy(buffer, &request, size) < B_OK)
+		if (user_memcpy(current, &request, size) < B_OK)
 			return B_BAD_ADDRESS;
 
-		buffer = (void *)((addr_t)buffer + size);
-		spaceLeft -= size;
+		current += size;
 	}
 
+	*_bufferSize = current - (uint8 *)buffer;;
 	return B_OK;
 }
 

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

@@ -72,7 +72,7 @@ void delete_interface(net_interface_private *interface);
 void get_device_interface_address(net_device_interface *interface,
 	sockaddr *address);
 uint32 count_device_interfaces();
-status_t list_device_interfaces(void *buffer, size_t size);
+status_t list_device_interfaces(void *buffer, size_t *_bufferSize);
 void put_device_interface(struct net_device_interface *interface);
 struct net_device_interface *get_device_interface(uint32 index);
 struct net_device_interface *get_device_interface(const char *name);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2006, Haiku, Inc. All Rights Reserved.
+ * Copyright 2006-2007, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -174,12 +174,17 @@ link_control(net_protocol *_protocol, int level, int option, void *value,
 
 		case SIOCGIFCONF:
 		{
-			// count number of interfaces
+			// retrieve available interfaces
 			struct ifconf config;
 			if (user_memcpy(&config, value, sizeof(struct ifconf)) < B_OK)
 				return B_BAD_ADDRESS;
 
-			return list_device_interfaces(config.ifc_buf, config.ifc_len);
+			status_t result = list_device_interfaces(config.ifc_buf,
+				(size_t *)&config.ifc_len);
+			if (result != B_OK)
+				return result;
+
+			return user_memcpy(value, &config, sizeof(struct ifconf));
 		}
 
 		case SIOCGIFADDR: