From Pontus Fuchs:

Add an interface monitor that, on Linux distributions with libnl,
watches for interfaces to appear or disappear and, on such an event,
causes windows showing interface lists to update.

svn path=/trunk/; revision=43521

1 files changed, 177 insertions, 0 deletions

diff --git a/iface_monitor.c b/iface_monitor.c
new file mode 100644
index 0000000000..ec65bd4076
--- /dev/null
+++ b/iface_monitor.c
@@ -0,0 +1,177 @@
+/* iface_monitor.c
+ * interface monitor by Pontus Fuchs <pontus.fuchs@gmail.com>
+ *
+ * $Id$
+ *
+ * Wireshark - Network traffic analyzer
+ * By Gerald Combs <gerald@wireshark.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * 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 2
+ * 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+#include "config.h"
+#include "iface_monitor.h"
+
+#ifdef HAVE_LIBNL
+
+#include <stdio.h>
+#include <strings.h>
+#include <errno.h>
+
+#include <net/if.h>
+
+#include <netlink/msg.h>
+#include <netlink/attr.h>
+#include <netlink/route/link.h>
+
+/* libnl 1.x compatibility code */
+#ifdef HAVE_LIBNL1
+#define nl_sock nl_handle
+#define nl_socket_disable_seq_check nl_disable_sequence_check
+
+static inline struct nl_handle *nl_socket_alloc(void)
+{
+    return nl_handle_alloc();
+}
+
+static inline void nl_socket_free(struct nl_sock *h)
+{
+    nl_handle_destroy(h);
+}
+#endif /* HAVE_LIBNL1 */
+
+static struct nl_sock *iface_mon_sock;
+
+static void
+iface_mon_handler2(struct nl_object *obj, void *arg)
+{
+    struct rtnl_link *filter;
+    struct rtnl_link *link_obj;
+    int flags, up;
+    char *ifname;
+    iface_mon_cb cb = arg;
+
+    filter = rtnl_link_alloc();
+    if (!filter) {
+        fprintf(stderr, "error allocating filter\n");
+        return;
+    }
+
+    if (nl_object_match_filter (obj, OBJ_CAST (filter)) == 0) {
+        rtnl_link_put(filter);
+        return;
+    }
+
+    link_obj = (struct rtnl_link *) obj;
+    flags = rtnl_link_get_flags (link_obj);
+    ifname = rtnl_link_get_name(link_obj);
+
+    up = (flags & IFF_UP) ? 1 : 0;
+
+    cb(ifname, up);
+
+    rtnl_link_put(filter);
+
+    return;
+}
+
+static int
+iface_mon_handler(struct nl_msg *msg, void *arg)
+{
+    nl_msg_parse (msg, &iface_mon_handler2, arg);
+    return 0;
+}
+
+static int
+iface_mon_nl_init(void *arg)
+{
+    int err;
+
+    iface_mon_sock = nl_socket_alloc();
+    if (!iface_mon_sock) {
+        fprintf(stderr, "Failed to allocate netlink socket.\n");
+        return -ENOMEM;
+    }
+
+    nl_socket_disable_seq_check(iface_mon_sock);
+
+    nl_socket_modify_cb(iface_mon_sock, NL_CB_VALID, NL_CB_CUSTOM, iface_mon_handler, arg);
+
+    if (nl_connect(iface_mon_sock, NETLINK_ROUTE)) {
+        fprintf(stderr, "Failed to connect to generic netlink.\n");
+        err = -ENOLINK;
+        goto out_handle_destroy;
+    }
+
+    nl_socket_add_membership(iface_mon_sock, RTNLGRP_LINK);
+
+    return 0;
+
+out_handle_destroy:
+    nl_socket_free(iface_mon_sock);
+    return err;
+}
+
+void
+iface_mon_event(void)
+{
+    nl_recvmsgs_default(iface_mon_sock);
+}
+
+int
+iface_mon_get_sock(void)
+{
+    return nl_socket_get_fd(iface_mon_sock);
+}
+
+int
+iface_mon_start(iface_mon_cb cb)
+{
+    return iface_mon_nl_init(cb);
+}
+
+void
+iface_mon_stop(void)
+{
+    if(iface_mon_sock)
+        nl_socket_free(iface_mon_sock);
+    iface_mon_sock = NULL;
+}
+
+#else /* HAVE_LIBNL */
+
+int
+iface_mon_start(iface_mon_cb cb _U_)
+{
+    return -1;
+}
+
+void
+iface_mon_stop(void)
+{
+}
+
+int
+iface_mon_get_sock(void)
+{
+    return -1;
+}
+
+void
+iface_mon_event(void)
+{
+}
+
+#endif /* HAVE_LIBNL */