Implement getifaddrs.

This is a BSD extension also available in glibc, but is not POSIX.
Fixes #6279.

headers/compatibility/bsd/ifaddrs.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright 2015, Haiku, Inc. All Rights Reserved.
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef _IFADDRS_H
+#define _IFADDRS_H
+
+
+struct ifaddrs {
+	struct ifaddrs  *ifa_next;    /* Next item in list */
+	const char      *ifa_name;    /* Name of interface */
+	unsigned int     ifa_flags;   /* Flags from SIOCGIFFLAGS */
+	struct sockaddr *ifa_addr;    /* Address of interface */
+	struct sockaddr *ifa_netmask; /* Netmask of interface */
+	struct sockaddr *ifa_dstaddr;
+	#define         ifa_broadaddr ifa_dstaddr
+	void            *ifa_data;    /* Address-specific data */
+};
+
+
+int getifaddrs(struct ifaddrs **ifap);
+void freeifaddrs(struct ifaddrs *ifa);
+
+
+#endif

src/kits/network/interfaces.cpp

@@ -1,12 +1,14 @@
 /*
- * Copyright 2006-2010, Haiku, Inc. All Rights Reserved.
+ * Copyright 2006-2015, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
  *		Axel Dörfler, [email protected]
+ *		Adrien Destugues, [email protected]
  */
 
 
+#include <errno.h>
 #include <net/if.h>
 #include <sys/socket.h>
 #include <sys/sockio.h>
@@ -15,6 +17,11 @@
 #include <unistd.h>
 
 #include <AutoDeleter.h>
+#include <NetworkAddress.h>
+#include <NetworkInterface.h>
+#include <NetworkRoster.h>
+
+#include "compatibility/bsd/ifaddrs.h"
 
 
 namespace BPrivate {
@@ -141,3 +148,68 @@ if_freenameindex(struct if_nameindex *interfaceArray)
 	free(interfaceArray);
 }
 
+
+int getifaddrs(struct ifaddrs **ifap)
+{
+	if (ifap == NULL) {
+		errno = B_BAD_VALUE;
+		return -1;
+	}
+
+	BNetworkRoster& roster = BNetworkRoster::Default();
+
+	uint32 cookie;
+
+	struct ifaddrs* previous = NULL;
+	struct ifaddrs* current = NULL;
+	BNetworkInterface* interface = new BNetworkInterface();
+
+	while (roster.GetNextInterface(&cookie, *interface) == B_OK) {
+		BNetworkInterfaceAddress address;
+		int32 i = 0;
+		while (interface->GetAddressAt(i++, address) == B_OK) {
+			current = new ifaddrs();
+
+			// Chain this interface with the next one
+			current->ifa_next = previous;
+			previous = current;
+
+			current->ifa_data = interface;
+			current->ifa_name = interface->Name();
+				// Points to the name in the BNetworkInterface instance, which
+				// is added as ifa_data so freeifaddrs can release it.
+			current->ifa_flags = address.Flags();
+			current->ifa_addr = new sockaddr(address.Address().SockAddr());
+			current->ifa_netmask = new sockaddr(address.Mask().SockAddr());
+			current->ifa_dstaddr = new sockaddr(address.Destination().SockAddr());
+		}
+
+		interface = new BNetworkInterface();
+	}
+
+	delete interface;
+	*ifap = current;
+
+	return 0;
+}
+
+
+void freeifaddrs(struct ifaddrs *ifa)
+{
+	struct ifaddrs* next;
+	BNetworkInterface* interface = NULL;
+	while (ifa != NULL) {
+		if (ifa->ifa_data != interface) {
+			interface = (BNetworkInterface*)ifa->ifa_data;
+			delete interface;
+		}
+
+		delete ifa->ifa_addr;
+		delete ifa->ifa_netmask;
+		delete ifa->ifa_dstaddr;
+
+		next = ifa->ifa_next;
+		delete ifa;
+		ifa = next;
+	}
+}