libqmi-glib,net-port-manager: split into abstract class plus rmnet implementation

6 files changed, 831 insertions, 658 deletions

diff --git a/src/libqmi-glib/Makefile.am b/src/libqmi-glib/Makefile.am
index 47e12fc..d65118b 100644
--- a/src/libqmi-glib/Makefile.am
+++ b/src/libqmi-glib/Makefile.am
@@ -76,6 +76,7 @@ libqmi_glib_la_SOURCES = \
 	qmi-endpoint.h qmi-endpoint.c \
 	qmi-endpoint-qmux.h qmi-endpoint-qmux.c \
 	qmi-net-port-manager.h qmi-net-port-manager.c \
+	qmi-net-port-manager-rmnet.h qmi-net-port-manager-rmnet.c \
 	$(NULL)
 
 nodist_libqmi_glib_la_SOURCES = \
diff --git a/src/libqmi-glib/qmi-device.c b/src/libqmi-glib/qmi-device.c
index 0f40f90..8221d97 100644
--- a/src/libqmi-glib/qmi-device.c
+++ b/src/libqmi-glib/qmi-device.c
@@ -59,7 +59,7 @@
 #include "qmi-error-types.h"
 #include "qmi-enum-types.h"
 #include "qmi-proxy.h"
-#include "qmi-net-port-manager.h"
+#include "qmi-net-port-manager-rmnet.h"
 #include "qmi-version.h"
 
 #if QMI_QRTR_SUPPORTED
@@ -1782,7 +1782,7 @@ qmi_device_add_link (QmiDevice           *self,
     task = g_task_new (self, cancellable, callback, user_data);
 
     if (!self->priv->net_port_manager) {
-        self->priv->net_port_manager = qmi_net_port_manager_new (&error);
+        self->priv->net_port_manager = QMI_NET_PORT_MANAGER (qmi_net_port_manager_rmnet_new (&error));
         if (!self->priv->net_port_manager) {
             g_debug ("Failed to create the net port manager: %s",
                      error->message);
@@ -1844,7 +1844,7 @@ qmi_device_delete_link (QmiDevice           *self,
     task = g_task_new (self, cancellable, callback, user_data);
 
     if (!self->priv->net_port_manager) {
-        self->priv->net_port_manager = qmi_net_port_manager_new (&error);
+        self->priv->net_port_manager = QMI_NET_PORT_MANAGER (qmi_net_port_manager_rmnet_new (&error));
         if (!self->priv->net_port_manager) {
             g_debug ("Failed to create the net port manager: %s",
                      error->message);
diff --git a/src/libqmi-glib/qmi-net-port-manager-rmnet.c b/src/libqmi-glib/qmi-net-port-manager-rmnet.c
new file mode 100644
index 0000000..c82df7a
--- /dev/null
+++ b/src/libqmi-glib/qmi-net-port-manager-rmnet.c
@@ -0,0 +1,682 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * libqmi-glib -- GLib/GIO based library to control QMI devices
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ * Copyright (C) 2020 Eric Caruso <ejcaruso@chromium.org>
+ * Copyright (C) 2020 Andrew Lassalle <andrewlassalle@chromium.org>
+ */
+
+#include <linux/if_link.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <net/if.h>
+#include <net/if_arp.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+
+#include "qmi-device.h"
+#include "qmi-error-types.h"
+#include "qmi-errors.h"
+#include "qmi-net-port-manager-rmnet.h"
+
+G_DEFINE_TYPE (QmiNetPortManagerRmnet, qmi_net_port_manager_rmnet, QMI_TYPE_NET_PORT_MANAGER)
+
+struct _QmiNetPortManagerRmnetPrivate {
+    /* Netlink socket */
+    GSocket *socket;
+    GSource *source;
+
+    /* Netlink state */
+    guint       current_sequence_id;
+    GHashTable *transactions;
+};
+
+#define RMNET_DATA_TYPE "rmnet"
+#define RMNET_MAX_MUX_ID 255
+
+/*****************************************************************************/
+
+static gchar *
+mux_id_to_ifname (const gchar *ifname_prefix,
+                  guint        mux_id)
+{
+    /*
+     * By convention, ifname_prefix0 corresponds to mux ID 1, and so on.
+     * A more defensive implementation of this class could always fetch
+     * mux ID via netlink for each existing rmnet interface instead of
+     * encoding it in the interface name in this manner, and then the
+     * interface name could just be assigned incrementally regardless
+     * of the mux ID. */
+    return g_strdup_printf ("%s%u", ifname_prefix, mux_id - 1);
+}
+
+/*****************************************************************************/
+/*
+ * Netlink message construction functions
+ */
+
+typedef GByteArray NetlinkMessage;
+
+typedef struct {
+    struct nlmsghdr  msghdr;
+    struct ifinfomsg ifreq;
+} NetlinkHeader;
+
+static NetlinkHeader *
+netlink_message_header (NetlinkMessage *msg)
+{
+    return (NetlinkHeader *) (msg->data);
+}
+
+static guint
+get_pos_of_next_attr (NetlinkMessage *msg)
+{
+    return NLMSG_ALIGN (msg->len);
+}
+
+static void
+append_netlink_attribute (NetlinkMessage *msg,
+                          gushort         type,
+                          gconstpointer   value,
+                          gushort         len)
+{
+    guint          attr_len;
+    guint          old_len;
+    guint          next_attr_rel_pos;
+    char          *next_attr_abs_pos;
+    struct rtattr  new_attr;
+
+    /* Expand the buffer to hold the new attribute */
+    attr_len = RTA_ALIGN (RTA_LENGTH (len));
+    old_len = msg->len;
+    next_attr_rel_pos = get_pos_of_next_attr (msg);
+
+    g_byte_array_set_size (msg, next_attr_rel_pos + attr_len);
+    /* fill new bytes with zero, since some padding is added between attributes. */
+    memset ((char *) msg->data + old_len, 0, msg->len - old_len);
+
+    new_attr.rta_type = type;
+    new_attr.rta_len = attr_len;
+    next_attr_abs_pos = (char *) msg->data + next_attr_rel_pos;
+    memcpy (next_attr_abs_pos, &new_attr, sizeof (struct rtattr));
+
+    if (value)
+        memcpy (RTA_DATA (next_attr_abs_pos), value, len);
+
+    /* Update the total netlink message length */
+    netlink_message_header (msg)->msghdr.nlmsg_len = msg->len;
+}
+
+static void
+append_netlink_attribute_nested (NetlinkMessage *msg,
+                                 gushort         type)
+{
+    append_netlink_attribute (msg, type, NULL, 0);
+}
+
+static void
+append_netlink_attribute_string (NetlinkMessage *msg,
+                                 gushort         type,
+                                 const gchar    *value)
+{
+    append_netlink_attribute (msg, type, value, strlen (value));
+}
+
+static void
+append_netlink_attribute_uint16 (NetlinkMessage *msg,
+                                 gushort         type,
+                                 guint16         value)
+{
+    append_netlink_attribute (msg, type, &value, sizeof (value));
+}
+
+static void
+append_netlink_attribute_uint32 (NetlinkMessage *msg,
+                                 gushort         type,
+                                 guint32         value)
+{
+    append_netlink_attribute (msg, type, &value, sizeof (value));
+}
+
+static NetlinkMessage *
+netlink_message_new (guint16 type,
+                     guint16 extra_flags)
+{
+    NetlinkMessage *msg;
+    NetlinkHeader  *hdr;
+
+    int size = sizeof (NetlinkHeader);
+
+    msg = g_byte_array_new ();
+    g_byte_array_set_size (msg, size);
+    memset ((char *) msg->data, 0, size);
+
+    hdr = netlink_message_header (msg);
+    hdr->msghdr.nlmsg_len = msg->len;
+    hdr->msghdr.nlmsg_type = type;
+    hdr->msghdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | extra_flags;
+    hdr->ifreq.ifi_family = AF_UNSPEC;
+    if (type != RTM_DELLINK) {
+        hdr->ifreq.ifi_type = ARPHRD_RAWIP;
+        hdr->ifreq.ifi_flags = 0;
+        hdr->ifreq.ifi_change = 0xFFFFFFFF;
+    }
+    return msg;
+}
+
+static void
+netlink_message_free (NetlinkMessage *msg)
+{
+    g_byte_array_unref (msg);
+}
+
+/*****************************************************************************/
+
+typedef struct {
+    QmiNetPortManagerRmnet *manager;
+    guint32                 sequence_id;
+    GSource                *timeout_source;
+    GTask                  *completion_task;
+} Transaction;
+
+static gboolean
+transaction_timed_out (Transaction *tr)
+{
+    GTask *task;
+    guint32 sequence_id;
+
+    task = g_steal_pointer (&tr->completion_task);
+    sequence_id = tr->sequence_id;
+
+    g_hash_table_remove (tr->manager->priv->transactions,
+                         GUINT_TO_POINTER (tr->sequence_id));
+
+    g_task_return_new_error (task,
+                             G_IO_ERROR,
+                             G_IO_ERROR_TIMED_OUT,
+                             "Netlink message with sequence ID %u timed out",
+                             sequence_id);
+
+    g_object_unref (task);
+    return G_SOURCE_REMOVE;
+}
+
+static void
+transaction_complete_with_error (Transaction *tr,
+                                 GError      *error)
+{
+    GTask *task;
+
+    task = g_steal_pointer (&tr->completion_task);
+
+    g_hash_table_remove (tr->manager->priv->transactions,
+                         GUINT_TO_POINTER (tr->sequence_id));
+
+    g_task_return_error (task, error);
+    g_object_unref (task);
+}
+
+static void
+transaction_complete (Transaction *tr,
+                      gint         saved_errno)
+{
+    GTask *task;
+    guint32 sequence_id;
+
+    task = g_steal_pointer (&tr->completion_task);
+    sequence_id = tr->sequence_id;
+
+    g_hash_table_remove (tr->manager->priv->transactions,
+                         GUINT_TO_POINTER (tr->sequence_id));
+
+    if (!saved_errno) {
+        g_task_return_boolean (task, TRUE);
+    } else {
+        g_task_return_new_error (task,
+                                 G_IO_ERROR,
+                                 g_io_error_from_errno (saved_errno),
+                                 "Netlink message with transaction %u failed",
+                                 sequence_id);
+    }
+
+    g_object_unref (task);
+}
+
+static void
+transaction_free (Transaction *tr)
+{
+    g_assert (tr->completion_task == NULL);
+    g_source_destroy (tr->timeout_source);
+    g_source_unref (tr->timeout_source);
+    g_slice_free (Transaction, tr);
+}
+
+static Transaction *
+transaction_new (QmiNetPortManagerRmnet *manager,
+                 NetlinkMessage         *msg,
+                 guint                   timeout,
+                 GTask                  *task)
+{
+    Transaction *tr;
+
+    tr = g_slice_new0 (Transaction);
+    tr->manager = manager;
+    tr->sequence_id = ++manager->priv->current_sequence_id;
+    netlink_message_header (msg)->msghdr.nlmsg_seq = tr->sequence_id;
+    if (timeout) {
+        tr->timeout_source = g_timeout_source_new_seconds (timeout);
+        g_source_set_callback (tr->timeout_source,
+                               (GSourceFunc) transaction_timed_out,
+                               tr,
+                               NULL);
+        g_source_attach (tr->timeout_source,
+                         g_main_context_get_thread_default ());
+    }
+    tr->completion_task = g_object_ref (task);
+
+    g_hash_table_insert (manager->priv->transactions,
+                         GUINT_TO_POINTER (tr->sequence_id),
+                         tr);
+    return tr;
+}
+
+/*****************************************************************************/
+
+static NetlinkMessage *
+netlink_message_new_link (guint  mux_id,
+                          gchar *ifname,
+                          guint  base_if_index)
+{
+    NetlinkMessage          *msg;
+    guint                    linkinfo_pos, datainfo_pos;
+    struct rtattr            info;
+    struct ifla_rmnet_flags  flags;
+
+    g_assert (mux_id != QMI_DEVICE_MUX_ID_UNBOUND);
+
+    msg = netlink_message_new (RTM_NEWLINK, NLM_F_CREATE | NLM_F_EXCL);
+    append_netlink_attribute_uint32 (msg, IFLA_LINK, base_if_index);
+    append_netlink_attribute_string (msg, IFLA_IFNAME, ifname);
+
+    /* Store the position of the next attribute to adjust its length later. */
+    linkinfo_pos = get_pos_of_next_attr (msg);
+    append_netlink_attribute_nested (msg, IFLA_LINKINFO);
+    append_netlink_attribute_string (msg, IFLA_INFO_KIND, RMNET_DATA_TYPE);
+
+    /* Store the position of the next attribute to adjust its length later. */
+    datainfo_pos = get_pos_of_next_attr (msg);
+    append_netlink_attribute_nested (msg, IFLA_INFO_DATA);
+    append_netlink_attribute_uint16 (msg, IFLA_RMNET_MUX_ID, mux_id);
+
+    flags.flags = RMNET_FLAGS_EGRESS_MAP_CKSUMV4 | RMNET_FLAGS_INGRESS_MAP_CKSUMV4 | RMNET_FLAGS_INGRESS_DEAGGREGATION;
+    flags.mask = flags.flags;
+    append_netlink_attribute (msg, IFLA_RMNET_FLAGS, &flags, sizeof (struct ifla_rmnet_flags));
+
+    /* Use memcpy to preserve byte alignment */
+    memcpy (&info, (char *) msg->data + datainfo_pos, sizeof (struct rtattr));
+    info.rta_len = msg->len - datainfo_pos;
+    memcpy ((char *) msg->data + datainfo_pos, &info, sizeof (struct rtattr));
+
+    memcpy (&info, (char *) msg->data + linkinfo_pos, sizeof (struct rtattr));
+    info.rta_len = msg->len - linkinfo_pos;
+    memcpy ((char *) msg->data + linkinfo_pos, &info, sizeof (struct rtattr));
+
+    return msg;
+}
+
+static NetlinkMessage *
+netlink_message_del_link (guint ifindex)
+{
+    NetlinkMessage *msg;
+
+    g_assert (ifindex != 0);
+
+    msg = netlink_message_new (RTM_DELLINK, 0);
+    netlink_message_header (msg)->ifreq.ifi_index = ifindex;
+
+    return msg;
+}
+
+/*****************************************************************************/
+
+static gboolean
+netlink_message_cb (GSocket                *socket,
+                    GIOCondition            condition,
+                    QmiNetPortManagerRmnet *self)
+{
+    GError          *error = NULL;
+    gchar            buf[512];
+    int              bytes_received;
+    unsigned int     buffer_len;
+    struct nlmsghdr *hdr;
+
+    if (condition & G_IO_HUP || condition & G_IO_ERR) {
+        g_warning ("[netlink] socket connection closed.");
+        return G_SOURCE_REMOVE;
+    }
+
+    bytes_received = g_socket_receive (socket, buf, sizeof (buf), NULL, &error);
+
+    if (bytes_received < 0) {
+        g_warning ("[netlink] socket i/o failure: %s", error->message);
+        g_error_free (error);
+        return G_SOURCE_REMOVE;
+    }
+
+    buffer_len = (unsigned int ) bytes_received;
+    for (hdr = (struct nlmsghdr *) buf; NLMSG_OK (hdr, buffer_len);
+         NLMSG_NEXT (hdr, buffer_len)) {
+        Transaction     *tr;
+        struct nlmsgerr *err;
+
+        if (hdr->nlmsg_type != NLMSG_ERROR)
+            continue;
+
+        tr = g_hash_table_lookup (self->priv->transactions,
+                                  GUINT_TO_POINTER (hdr->nlmsg_seq));
+        if (!tr)
+            continue;
+
+        err = NLMSG_DATA (buf);
+        transaction_complete (tr, err->error);
+    }
+    return G_SOURCE_CONTINUE;
+}
+
+/*****************************************************************************/
+
+static guint
+get_first_free_mux_id (QmiNetPortManagerRmnet *self,
+                       const gchar            *ifname_prefix)
+{
+    guint i;
+
+    /* Note that this function does not actually need to use the
+     * QmiNetPortManagerRmnet at the moment. But it will if we ever do rewrite it
+     * to inspect mux IDs of existing rmnet interfaces, so we will pass it
+     * for now. */
+
+    for (i = 1; i <= RMNET_MAX_MUX_ID; i++) {
+        gchar   *ifname;
+        gboolean mux_id_is_free;
+
+        ifname = mux_id_to_ifname (ifname_prefix, i);
+        mux_id_is_free = !if_nametoindex (ifname);
+        g_free (ifname);
+        if (mux_id_is_free)
+            return i;
+    }
+
+    return QMI_DEVICE_MUX_ID_UNBOUND;
+}
+
+/*****************************************************************************/
+typedef struct {
+    guint  mux_id;
+    gchar *ifname;
+} AddLinkContext;
+
+static void
+add_link_context_free (AddLinkContext *ctx)
+{
+    g_free (ctx->ifname);
+    g_free (ctx);
+}
+
+static gchar *
+net_port_manager_add_link_finish (QmiNetPortManager  *self,
+                                  guint              *mux_id,
+                                  GAsyncResult       *res,
+                                  GError            **error)
+{
+    AddLinkContext *ctx;
+
+    ctx = g_task_get_task_data (G_TASK (res));
+
+    if (!g_task_propagate_boolean (G_TASK (res), error)) {
+        g_prefix_error (error, "Failed to add link with mux id %d: ",
+                        ctx->mux_id);
+        return NULL;
+    }
+
+    *mux_id = ctx->mux_id;
+    return g_steal_pointer (&ctx->ifname);
+}
+
+static void
+net_port_manager_add_link (QmiNetPortManager   *_self,
+                           guint                mux_id,
+                           const gchar         *base_ifname,
+                           const gchar         *ifname_prefix,
+                           guint                timeout,
+                           GCancellable        *cancellable,
+                           GAsyncReadyCallback  callback,
+                           gpointer             user_data)
+{
+    QmiNetPortManagerRmnet *self = QMI_NET_PORT_MANAGER_RMNET (_self);
+    NetlinkMessage         *msg;
+    Transaction            *tr;
+    GTask                  *task;
+    GError                 *error = NULL;
+    gssize                  bytes_sent;
+    guint                   base_if_index;
+    AddLinkContext         *ctx;
+
+    task = g_task_new (self, cancellable, callback, user_data);
+
+    ctx = g_new0 (AddLinkContext, 1);
+    ctx->mux_id = mux_id;
+    g_task_set_task_data (task, ctx, (GDestroyNotify) add_link_context_free);
+
+    if (ctx->mux_id == QMI_DEVICE_MUX_ID_UNBOUND) {
+        g_task_return_new_error (task,
+                                 QMI_CORE_ERROR,
+                                 QMI_CORE_ERROR_FAILED,
+                                 "Tried to create interface for unbound mux ID");
+        g_object_unref (task);
+        return;
+    }
+
+    if (ctx->mux_id == QMI_DEVICE_MUX_ID_AUTOMATIC) {
+        ctx->mux_id = get_first_free_mux_id (self, ifname_prefix);
+
+        g_debug ("Using dynamic mux ID %u", ctx->mux_id);
+        if (ctx->mux_id == QMI_DEVICE_MUX_ID_UNBOUND) {
+            g_task_return_new_error (task,
+                                     QMI_CORE_ERROR,
+                                     QMI_CORE_ERROR_FAILED,
+                                     "Failed to find an available mux ID");
+            g_object_unref (task);
+            return;
+        }
+    } else
+        g_debug ("Using static mux ID %u", ctx->mux_id);
+
+    base_if_index = if_nametoindex (base_ifname);
+    if (!base_if_index) {
+        g_task_return_new_error (task,
+                                 QMI_CORE_ERROR,
+                                 QMI_CORE_ERROR_FAILED,
+                                 "%s interface is not available",
+                                 base_ifname);
+        g_object_unref (task);
+        return;
+    }
+
+    ctx->ifname = mux_id_to_ifname (ifname_prefix, ctx->mux_id);
+
+    msg = netlink_message_new_link (ctx->mux_id, ctx->ifname, base_if_index);
+
+    /* The task ownership is transferred to the transaction. */
+    tr = transaction_new (self, msg, timeout, task);
+
+    bytes_sent = g_socket_send (self->priv->socket,
+                                (const gchar *) msg->data,
+                                msg->len,
+                                cancellable,
+                                &error);
+    netlink_message_free (msg);
+
+    if (bytes_sent < 0)
+        transaction_complete_with_error (tr, error);
+
+    g_object_unref (task);
+}
+
+static gboolean
+net_port_manager_del_link_finish (QmiNetPortManager  *self,
+                                  GAsyncResult       *res,
+                                  GError            **error)
+{
+    return g_task_propagate_boolean (G_TASK (res), error);
+}
+
+static void
+net_port_manager_del_link (QmiNetPortManager   *_self,
+                           const gchar         *ifname,
+                           guint                timeout,
+                           GCancellable        *cancellable,
+                           GAsyncReadyCallback  callback,
+                           gpointer             user_data)
+{
+    QmiNetPortManagerRmnet *self = QMI_NET_PORT_MANAGER_RMNET (_self);
+    guint                   ifindex;
+    NetlinkMessage         *msg;
+    Transaction            *tr;
+    GTask                  *task;
+    GError                 *error = NULL;
+    gssize                  bytes_sent;
+
+    task = g_task_new (self, cancellable, callback, user_data);
+
+    ifindex = if_nametoindex (ifname);
+    if (ifindex == 0) {
+        g_task_return_new_error (task,
+                                 QMI_CORE_ERROR,
+                                 QMI_CORE_ERROR_FAILED,
+                                 "Failed to retrieve interface index for interface:%s",
+                                 ifname);
+        g_object_unref (task);
+        return;
+    }
+
+    msg = netlink_message_del_link (ifindex);
+    /* The task ownership is transferred to the transaction. */
+    tr = transaction_new (self, msg, timeout, task);
+
+    bytes_sent = g_socket_send (self->priv->socket,
+                                (const gchar *) msg->data,
+                                msg->len,
+                                cancellable,
+                                &error);
+    netlink_message_free (msg);
+
+    if (bytes_sent < 0)
+        transaction_complete_with_error (tr, error);
+
+    g_object_unref (task);
+}
+
+/*****************************************************************************/
+
+QmiNetPortManagerRmnet *
+qmi_net_port_manager_rmnet_new (GError **error)
+{
+    QmiNetPortManagerRmnet *self;
+    gint                    socket_fd;
+    GSocket                *gsocket;
+    GError                 *inner_error = NULL;
+
+    socket_fd = socket (AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
+    if (socket_fd < 0) {
+        g_set_error (error,
+                     QMI_CORE_ERROR,
+                     QMI_CORE_ERROR_FAILED,
+                     "Failed to create netlink socket");
+        return NULL;
+    }
+
+    gsocket = g_socket_new_from_fd (socket_fd, &inner_error);
+    if (inner_error) {
+        g_debug ("Could not create socket: %s", inner_error->message);
+        close (socket_fd);
+        g_propagate_error (error, inner_error);
+        return NULL;
+    }
+
+    self = g_object_new (QMI_TYPE_NET_PORT_MANAGER_RMNET, NULL);
+    self->priv->socket = gsocket;
+    self->priv->source = g_socket_create_source (self->priv->socket,
+                                                 G_IO_IN | G_IO_ERR | G_IO_HUP,
+                                                 NULL);
+    g_source_set_callback (self->priv->source,
+                           (GSourceFunc) netlink_message_cb,
+                           self,
+                           NULL);
+    g_source_attach (self->priv->source, g_main_context_get_thread_default ());
+
+    self->priv->current_sequence_id = 0;
+    self->priv->transactions =
+        g_hash_table_new_full (g_direct_hash,
+                               g_direct_equal,
+                               NULL,
+                               (GDestroyNotify) transaction_free);
+    return self;
+}
+
+/*****************************************************************************/
+
+static void
+qmi_net_port_manager_rmnet_init (QmiNetPortManagerRmnet *self)
+{
+    self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
+                                              QMI_TYPE_NET_PORT_MANAGER_RMNET,
+                                              QmiNetPortManagerRmnetPrivate);
+}
+
+static void
+dispose (GObject *object)
+{
+    QmiNetPortManagerRmnet *self = QMI_NET_PORT_MANAGER_RMNET (object);
+
+    g_assert (g_hash_table_size (self->priv->transactions) == 0);
+
+    g_clear_pointer (&self->priv->transactions, g_hash_table_unref);
+    if (self->priv->source)
+        g_source_destroy (self->priv->source);
+    g_clear_pointer (&self->priv->source, g_source_unref);
+    g_clear_object (&self->priv->socket);
+
+    G_OBJECT_CLASS (qmi_net_port_manager_rmnet_parent_class)->dispose (object);
+}
+
+static void
+qmi_net_port_manager_rmnet_class_init (QmiNetPortManagerRmnetClass *klass)
+{
+    GObjectClass           *object_class = G_OBJECT_CLASS (klass);
+    QmiNetPortManagerClass *net_port_manager_class = QMI_NET_PORT_MANAGER_CLASS (klass);
+
+    g_type_class_add_private (object_class, sizeof (QmiNetPortManagerRmnetPrivate));
+
+    object_class->dispose = dispose;
+
+    net_port_manager_class->add_link = net_port_manager_add_link;
+    net_port_manager_class->add_link_finish = net_port_manager_add_link_finish;
+    net_port_manager_class->del_link = net_port_manager_del_link;
+    net_port_manager_class->del_link_finish = net_port_manager_del_link_finish;
+}
diff --git a/src/libqmi-glib/qmi-net-port-manager-rmnet.h b/src/libqmi-glib/qmi-net-port-manager-rmnet.h
new file mode 100644
index 0000000..2cdfd4d
--- /dev/null
+++ b/src/libqmi-glib/qmi-net-port-manager-rmnet.h
@@ -0,0 +1,57 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * libqmi-glib -- GLib/GIO based library to control QMI devices
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ * Copyright (C) 2020 Eric Caruso <ejcaruso@chromium.org>
+ * Copyright (C) 2020 Andrew Lassalle <andrewlassalle@chromium.org>
+ */
+
+#ifndef _LIBQMI_GLIB_QMI_NET_PORT_MANAGER_RMNET_H_
+#define _LIBQMI_GLIB_QMI_NET_PORT_MANAGER_RMNET_H_
+
+#include <gio/gio.h>
+#include <glib-object.h>
+
+#include "qmi-net-port-manager.h"
+
+#define QMI_TYPE_NET_PORT_MANAGER_RMNET            (qmi_net_port_manager_rmnet_get_type ())
+#define QMI_NET_PORT_MANAGER_RMNET(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), QMI_TYPE_NET_PORT_MANAGER_RMNET, QmiNetPortManagerRmnet))
+#define QMI_NET_PORT_MANAGER_RMNET_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  QMI_TYPE_NET_PORT_MANAGER_RMNET, QmiNetPortManagerRmnetClass))
+#define QMI_IS_NET_PORT_MANAGER_RMNET(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), QMI_TYPE_NET_PORT_MANAGER_RMNET))
+#define QMI_IS_NET_PORT_MANAGER_RMNET_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  QMI_TYPE_NET_PORT_MANAGER_RMNET))
+#define QMI_NET_PORT_MANAGER_RMNET_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  QMI_TYPE_NET_PORT_MANAGER_RMNET, QmiNetPortManagerRmnetClass))
+
+typedef struct _QmiNetPortManagerRmnet        QmiNetPortManagerRmnet;
+typedef struct _QmiNetPortManagerRmnetClass   QmiNetPortManagerRmnetClass;
+typedef struct _QmiNetPortManagerRmnetPrivate QmiNetPortManagerRmnetPrivate;
+
+struct _QmiNetPortManagerRmnet {
+    QmiNetPortManager              parent;
+    QmiNetPortManagerRmnetPrivate *priv;
+};
+
+struct _QmiNetPortManagerRmnetClass {
+    QmiNetPortManagerClass parent;
+};
+
+GType qmi_net_port_manager_rmnet_get_type (void);
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (QmiNetPortManagerRmnet, g_object_unref)
+
+QmiNetPortManagerRmnet *qmi_net_port_manager_rmnet_new (GError **error);
+
+#endif /* _LIBQMI_GLIB_QMI_NET_PORT_MANAGER_RMNET_H_ */
diff --git a/src/libqmi-glib/qmi-net-port-manager.c b/src/libqmi-glib/qmi-net-port-manager.c
index 3708b7c..c94ab7f 100644
--- a/src/libqmi-glib/qmi-net-port-manager.c
+++ b/src/libqmi-glib/qmi-net-port-manager.c
@@ -17,524 +17,58 @@
  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301 USA.
  *
- * Copyright (C) 2020 Eric Caruso <ejcaruso@chromium.org>
- * Copyright (C) 2020 Andrew Lassalle <andrewlassalle@chromium.org>
+ * Copyright (C) 2021 Aleksander Morgado <aleksander@aleksander.es>
  */
 
 #include "qmi-net-port-manager.h"
 
-#include <linux/if_link.h>
-#include <linux/netlink.h>
-#include <linux/rtnetlink.h>
-#include <net/if.h>
-#include <net/if_arp.h>
-#include <sys/socket.h>
-#include <sys/types.h>
-
-#include "qmi-device.h"
-#include "qmi-error-types.h"
-#include "qmi-errors.h"
-
-G_DEFINE_TYPE (QmiNetPortManager, qmi_net_port_manager, G_TYPE_OBJECT)
-
-struct _QmiNetPortManagerPrivate {
-    /* Netlink socket */
-    GSocket *socket;
-    GSource *source;
-
-    /* Netlink state */
-    guint       current_sequence_id;
-    GHashTable *transactions;
-};
-
-#define RMNET_DATA_TYPE "rmnet"
-#define RMNET_MAX_MUX_ID 255
-/*****************************************************************************/
-
-static gchar *
-mux_id_to_ifname (const gchar *ifname_prefix,
-                  guint        mux_id)
-{
-    /*
-     * By convention, ifname_prefix0 corresponds to mux ID 1, and so on.
-     * A more defensive implementation of this class could always fetch
-     * mux ID via netlink for each existing rmnet interface instead of
-     * encoding it in the interface name in this manner, and then the
-     * interface name could just be assigned incrementally regardless
-     * of the mux ID. */
-    return g_strdup_printf ("%s%u", ifname_prefix, mux_id - 1);
-}
-
-/*****************************************************************************/
-/*
- * Netlink message construction functions
- */
-
-typedef GByteArray NetlinkMessage;
-
-typedef struct {
-    struct nlmsghdr  msghdr;
-    struct ifinfomsg ifreq;
-} NetlinkHeader;
-
-static NetlinkHeader *
-netlink_message_header (NetlinkMessage *msg)
-{
-    return (NetlinkHeader *) (msg->data);
-}
-
-static guint
-get_pos_of_next_attr (NetlinkMessage *msg)
-{
-    return NLMSG_ALIGN (msg->len);
-}
-
-static void
-append_netlink_attribute (NetlinkMessage *msg,
-                          gushort         type,
-                          gconstpointer   value,
-                          gushort         len)
-{
-    guint          attr_len;
-    guint          old_len;
-    guint          next_attr_rel_pos;
-    char          *next_attr_abs_pos;
-    struct rtattr  new_attr;
-
-    /* Expand the buffer to hold the new attribute */
-    attr_len = RTA_ALIGN (RTA_LENGTH (len));
-    old_len = msg->len;
-    next_attr_rel_pos = get_pos_of_next_attr (msg);
-
-    g_byte_array_set_size (msg, next_attr_rel_pos + attr_len);
-    /* fill new bytes with zero, since some padding is added between attributes. */
-    memset ((char *) msg->data + old_len, 0, msg->len - old_len);
-
-    new_attr.rta_type = type;
-    new_attr.rta_len = attr_len;
-    next_attr_abs_pos = (char *) msg->data + next_attr_rel_pos;
-    memcpy (next_attr_abs_pos, &new_attr, sizeof (struct rtattr));
-
-    if (value)
-        memcpy (RTA_DATA (next_attr_abs_pos), value, len);
-
-    /* Update the total netlink message length */
-    netlink_message_header (msg)->msghdr.nlmsg_len = msg->len;
-}
-
-static void
-append_netlink_attribute_nested (NetlinkMessage *msg,
-                                 gushort         type)
-{
-    append_netlink_attribute (msg, type, NULL, 0);
-}
-
-static void
-append_netlink_attribute_string (NetlinkMessage *msg,
-                                 gushort         type,
-                                 const gchar    *value)
-{
-    append_netlink_attribute (msg, type, value, strlen (value));
-}
-
-static void
-append_netlink_attribute_uint16 (NetlinkMessage *msg,
-                                 gushort         type,
-                                 guint16         value)
-{
-    append_netlink_attribute (msg, type, &value, sizeof (value));
-}
-
-static void
-append_netlink_attribute_uint32 (NetlinkMessage *msg,
-                                 gushort         type,
-                                 guint32         value)
-{
-    append_netlink_attribute (msg, type, &value, sizeof (value));
-}
-
-static NetlinkMessage *
-netlink_message_new (guint16 type,
-                     guint16 extra_flags)
-{
-    NetlinkMessage *msg;
-    NetlinkHeader  *hdr;
-
-    int size = sizeof (NetlinkHeader);
-
-    msg = g_byte_array_new ();
-    g_byte_array_set_size (msg, size);
-    memset ((char *) msg->data, 0, size);
-
-    hdr = netlink_message_header (msg);
-    hdr->msghdr.nlmsg_len = msg->len;
-    hdr->msghdr.nlmsg_type = type;
-    hdr->msghdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK | extra_flags;
-    hdr->ifreq.ifi_family = AF_UNSPEC;
-    if (type != RTM_DELLINK) {
-        hdr->ifreq.ifi_type = ARPHRD_RAWIP;
-        hdr->ifreq.ifi_flags = 0;
-        hdr->ifreq.ifi_change = 0xFFFFFFFF;
-    }
-    return msg;
-}
-
-static void
-netlink_message_free (NetlinkMessage *msg)
-{
-    g_byte_array_unref (msg);
-}
-
-/*****************************************************************************/
-
-typedef struct {
-    QmiNetPortManager *manager;
-    guint32            sequence_id;
-    GSource           *timeout_source;
-    GTask             *completion_task;
-} Transaction;
-
-static gboolean
-transaction_timed_out (Transaction *tr)
-{
-    GTask *task;
-    guint32 sequence_id;
-
-    task = g_steal_pointer (&tr->completion_task);
-    sequence_id = tr->sequence_id;
-
-    g_hash_table_remove (tr->manager->priv->transactions,
-                         GUINT_TO_POINTER (tr->sequence_id));
-
-    g_task_return_new_error (task,
-                             G_IO_ERROR,
-                             G_IO_ERROR_TIMED_OUT,
-                             "Netlink message with sequence ID %u timed out",
-                             sequence_id);
-
-    g_object_unref (task);
-    return G_SOURCE_REMOVE;
-}
-
-static void
-transaction_complete_with_error (Transaction *tr,
-                                 GError      *error)
-{
-    GTask *task;
-
-    task = g_steal_pointer (&tr->completion_task);
-
-    g_hash_table_remove (tr->manager->priv->transactions,
-                         GUINT_TO_POINTER (tr->sequence_id));
-
-    g_task_return_error (task, error);
-    g_object_unref (task);
-}
-
-static void
-transaction_complete (Transaction *tr,
-                      gint         saved_errno)
-{
-    GTask *task;
-    guint32 sequence_id;
-
-    task = g_steal_pointer (&tr->completion_task);
-    sequence_id = tr->sequence_id;
-
-    g_hash_table_remove (tr->manager->priv->transactions,
-                         GUINT_TO_POINTER (tr->sequence_id));
-
-    if (!saved_errno) {
-        g_task_return_boolean (task, TRUE);
-    } else {
-        g_task_return_new_error (task,
-                                 G_IO_ERROR,
-                                 g_io_error_from_errno (saved_errno),
-                                 "Netlink message with transaction %u failed",
-                                 sequence_id);
-    }
-
-    g_object_unref (task);
-}
-
-static void
-transaction_free (Transaction *tr)
-{
-    g_assert (tr->completion_task == NULL);
-    g_source_destroy (tr->timeout_source);
-    g_source_unref (tr->timeout_source);
-    g_slice_free (Transaction, tr);
-}
-
-static Transaction *
-transaction_new (QmiNetPortManager *manager,
-                 NetlinkMessage    *msg,
-                 guint              timeout,
-                 GTask             *task)
-{
-    Transaction *tr;
-
-    tr = g_slice_new0 (Transaction);
-    tr->manager = manager;
-    tr->sequence_id = ++manager->priv->current_sequence_id;
-    netlink_message_header (msg)->msghdr.nlmsg_seq = tr->sequence_id;
-    if (timeout) {
-        tr->timeout_source = g_timeout_source_new_seconds (timeout);
-        g_source_set_callback (tr->timeout_source,
-                               (GSourceFunc) transaction_timed_out,
-                               tr,
-                               NULL);
-        g_source_attach (tr->timeout_source,
-                         g_main_context_get_thread_default ());
-    }
-    tr->completion_task = g_object_ref (task);
-
-    g_hash_table_insert (manager->priv->transactions,
-                         GUINT_TO_POINTER (tr->sequence_id),
-                         tr);
-    return tr;
-}
+G_DEFINE_ABSTRACT_TYPE (QmiNetPortManager, qmi_net_port_manager, G_TYPE_OBJECT)
 
 /*****************************************************************************/
 
-static NetlinkMessage *
-netlink_message_new_link (guint  mux_id,
-                          gchar *ifname,
-                          guint  base_if_index)
-{
-    NetlinkMessage          *msg;
-    guint                    linkinfo_pos, datainfo_pos;
-    struct rtattr            info;
-    struct ifla_rmnet_flags  flags;
-
-    g_assert (mux_id != QMI_DEVICE_MUX_ID_UNBOUND);
-
-    msg = netlink_message_new (RTM_NEWLINK, NLM_F_CREATE | NLM_F_EXCL);
-    append_netlink_attribute_uint32 (msg, IFLA_LINK, base_if_index);
-    append_netlink_attribute_string (msg, IFLA_IFNAME, ifname);
-
-    /* Store the position of the next attribute to adjust its length later. */
-    linkinfo_pos = get_pos_of_next_attr (msg);
-    append_netlink_attribute_nested (msg, IFLA_LINKINFO);
-    append_netlink_attribute_string (msg, IFLA_INFO_KIND, RMNET_DATA_TYPE);
-
-    /* Store the position of the next attribute to adjust its length later. */
-    datainfo_pos = get_pos_of_next_attr (msg);
-    append_netlink_attribute_nested (msg, IFLA_INFO_DATA);
-    append_netlink_attribute_uint16 (msg, IFLA_RMNET_MUX_ID, mux_id);
-
-    flags.flags = RMNET_FLAGS_EGRESS_MAP_CKSUMV4 | RMNET_FLAGS_INGRESS_MAP_CKSUMV4 | RMNET_FLAGS_INGRESS_DEAGGREGATION;
-    flags.mask = flags.flags;
-    append_netlink_attribute (msg, IFLA_RMNET_FLAGS, &flags, sizeof (struct ifla_rmnet_flags));
-
-    /* Use memcpy to preserve byte alignment */
-    memcpy (&info, (char *) msg->data + datainfo_pos, sizeof (struct rtattr));
-    info.rta_len = msg->len - datainfo_pos;
-    memcpy ((char *) msg->data + datainfo_pos, &info, sizeof (struct rtattr));
-
-    memcpy (&info, (char *) msg->data + linkinfo_pos, sizeof (struct rtattr));
-    info.rta_len = msg->len - linkinfo_pos;
-    memcpy ((char *) msg->data + linkinfo_pos, &info, sizeof (struct rtattr));
-
-    return msg;
-}
-
-static NetlinkMessage *
-netlink_message_del_link (guint ifindex)
-{
-    NetlinkMessage *msg;
-
-    g_assert (ifindex != 0);
-
-    msg = netlink_message_new (RTM_DELLINK, 0);
-    netlink_message_header (msg)->ifreq.ifi_index = ifindex;
-
-    return msg;
-}
-
-/*****************************************************************************/
-
-static gboolean
-netlink_message_cb (GSocket           *socket,
-                    GIOCondition       condition,
-                    QmiNetPortManager *self)
-{
-    GError          *error = NULL;
-    gchar            buf[512];
-    int              bytes_received;
-    unsigned int     buffer_len;
-    struct nlmsghdr *hdr;
-
-    if (condition & G_IO_HUP || condition & G_IO_ERR) {
-        g_warning ("[netlink] socket connection closed.");
-        return G_SOURCE_REMOVE;
-    }
-
-    bytes_received = g_socket_receive (socket, buf, sizeof (buf), NULL, &error);
-
-    if (bytes_received < 0) {
-        g_warning ("[netlink] socket i/o failure: %s", error->message);
-        g_error_free (error);
-        return G_SOURCE_REMOVE;
-    }
-
-    buffer_len = (unsigned int ) bytes_received;
-    for (hdr = (struct nlmsghdr *) buf; NLMSG_OK (hdr, buffer_len);
-         NLMSG_NEXT (hdr, buffer_len)) {
-        Transaction     *tr;
-        struct nlmsgerr *err;
-
-        if (hdr->nlmsg_type != NLMSG_ERROR)
-            continue;
-
-        tr = g_hash_table_lookup (self->priv->transactions,
-                                  GUINT_TO_POINTER (hdr->nlmsg_seq));
-        if (!tr)
-            continue;
-
-        err = NLMSG_DATA (buf);
-        transaction_complete (tr, err->error);
-    }
-    return G_SOURCE_CONTINUE;
-}
-
-/*****************************************************************************/
-
-static guint
-get_first_free_mux_id (QmiNetPortManager *self,
-                       const gchar       *ifname_prefix)
-{
-    guint i;
-
-    /* Note that this function does not actually need to use the
-     * QmiNetPortManager at the moment. But it will if we ever do rewrite it
-     * to inspect mux IDs of existing rmnet interfaces, so we will pass it
-     * for now. */
-
-    for (i = 1; i <= RMNET_MAX_MUX_ID; i++) {
-        gchar   *ifname;
-        gboolean mux_id_is_free;
-
-        ifname = mux_id_to_ifname (ifname_prefix, i);
-        mux_id_is_free = !if_nametoindex (ifname);
-        g_free (ifname);
-        if (mux_id_is_free)
-            return i;
-    }
-
-    return QMI_DEVICE_MUX_ID_UNBOUND;
-}
-
-/*****************************************************************************/
-typedef struct {
-    guint  mux_id;
-    gchar *ifname;
-} AddLinkContext;
-
-static void
-add_link_context_free (AddLinkContext *ctx)
-{
-    g_free (ctx->ifname);
-    g_free (ctx);
+void
+qmi_net_port_manager_add_link (QmiNetPortManager    *self,
+                               guint                 mux_id,
+                               const gchar          *base_ifname,
+                               const gchar          *ifname_prefix,
+                               guint                 timeout,
+                               GCancellable         *cancellable,
+                               GAsyncReadyCallback   callback,
+                               gpointer              user_data)
+{
+    QMI_NET_PORT_MANAGER_GET_CLASS (self)->add_link (self,
+                                                     mux_id,
+                                                     base_ifname,
+                                                     ifname_prefix,
+                                                     timeout,
+                                                     cancellable,
+                                                     callback,
+                                                     user_data);
 }
 
 gchar *
-qmi_net_port_manager_add_link_finish (QmiNetPortManager *self,
-                                      guint             *mux_id,
-                                      GAsyncResult      *res,
-                                      GError           **error)
+qmi_net_port_manager_add_link_finish (QmiNetPortManager  *self,
+                                      guint              *mux_id,
+                                      GAsyncResult       *res,
+                                      GError            **error)
 {
-    AddLinkContext *ctx;
-
-    ctx = g_task_get_task_data (G_TASK (res));
-
-    if (!g_task_propagate_boolean (G_TASK (res), error)) {
-        g_prefix_error (error, "Failed to add link with mux id %d: ",
-                        ctx->mux_id);
-        return NULL;
-    }
-
-    *mux_id = ctx->mux_id;
-    return g_steal_pointer (&ctx->ifname);
+    return QMI_NET_PORT_MANAGER_GET_CLASS (self)->add_link_finish (self, mux_id, res, error);
 }
 
 void
-qmi_net_port_manager_add_link (QmiNetPortManager   *self,
-                               guint                mux_id,
-                               const gchar         *base_ifname,
-                               const gchar         *ifname_prefix,
-                               guint                timeout,
-                               GCancellable        *cancellable,
-                               GAsyncReadyCallback  callback,
-                               gpointer             user_data)
+qmi_net_port_manager_del_link (QmiNetPortManager    *self,
+                               const gchar          *ifname,
+                               guint                 timeout,
+                               GCancellable         *cancellable,
+                               GAsyncReadyCallback   callback,
+                               gpointer              user_data)
 {
-    NetlinkMessage *msg;
-    Transaction    *tr;
-    GTask          *task;
-    GError         *error = NULL;
-    gssize          bytes_sent;
-    guint           base_if_index;
-    AddLinkContext *ctx;
-
-    task = g_task_new (self, cancellable, callback, user_data);
-
-    ctx = g_new0 (AddLinkContext, 1);
-    ctx->mux_id = mux_id;
-    g_task_set_task_data (task, ctx, (GDestroyNotify) add_link_context_free);
-
-    if (ctx->mux_id == QMI_DEVICE_MUX_ID_UNBOUND) {
-        g_task_return_new_error (task,
-                                 QMI_CORE_ERROR,
-                                 QMI_CORE_ERROR_FAILED,
-                                 "Tried to create interface for unbound mux ID");
-        g_object_unref (task);
-        return;
-    }
-
-    if (ctx->mux_id == QMI_DEVICE_MUX_ID_AUTOMATIC) {
-        ctx->mux_id = get_first_free_mux_id (self, ifname_prefix);
-
-        g_debug ("Using dynamic mux ID %u", ctx->mux_id);
-        if (ctx->mux_id == QMI_DEVICE_MUX_ID_UNBOUND) {
-            g_task_return_new_error (task,
-                                     QMI_CORE_ERROR,
-                                     QMI_CORE_ERROR_FAILED,
-                                     "Failed to find an available mux ID");
-            g_object_unref (task);
-            return;
-        }
-    } else
-        g_debug ("Using static mux ID %u", ctx->mux_id);
-
-    base_if_index = if_nametoindex (base_ifname);
-    if (!base_if_index) {
-        g_task_return_new_error (task,
-                                 QMI_CORE_ERROR,
-                                 QMI_CORE_ERROR_FAILED,
-                                 "%s interface is not available",
-                                 base_ifname);
-        g_object_unref (task);
-        return;
-    }
-
-    ctx->ifname = mux_id_to_ifname (ifname_prefix, ctx->mux_id);
-
-    msg = netlink_message_new_link (ctx->mux_id, ctx->ifname, base_if_index);
-
-    /* The task ownership is transferred to the transaction. */
-    tr = transaction_new (self, msg, timeout, task);
-
-    bytes_sent = g_socket_send (self->priv->socket,
-                                (const gchar *) msg->data,
-                                msg->len,
-                                cancellable,
-                                &error);
-    netlink_message_free (msg);
-
-    if (bytes_sent < 0)
-        transaction_complete_with_error (tr, error);
-
-    g_object_unref (task);
+    QMI_NET_PORT_MANAGER_GET_CLASS (self)->del_link (self,
+                                                     ifname,
+                                                     timeout,
+                                                     cancellable,
+                                                     callback,
+                                                     user_data);
 }
 
 gboolean
@@ -542,99 +76,7 @@ qmi_net_port_manager_del_link_finish (QmiNetPortManager  *self,
                                       GAsyncResult       *res,
                                       GError            **error)
 {
-    return g_task_propagate_boolean (G_TASK (res), error);
-}
-
-void
-qmi_net_port_manager_del_link (QmiNetPortManager   *self,
-                               const gchar         *ifname,
-                               guint                timeout,
-                               GCancellable        *cancellable,
-                               GAsyncReadyCallback  callback,
-                               gpointer             user_data)
-{
-    guint           ifindex;
-    NetlinkMessage *msg;
-    Transaction    *tr;
-    GTask          *task;
-    GError         *error = NULL;
-    gssize          bytes_sent;
-
-    task = g_task_new (self, cancellable, callback, user_data);
-
-    ifindex = if_nametoindex (ifname);
-    if (ifindex == 0) {
-        g_task_return_new_error (task,
-                                 QMI_CORE_ERROR,
-                                 QMI_CORE_ERROR_FAILED,
-                                 "Failed to retrieve interface index for interface:%s",
-                                 ifname);
-        g_object_unref (task);
-        return;
-    }
-
-    msg = netlink_message_del_link (ifindex);
-    /* The task ownership is transferred to the transaction. */
-    tr = transaction_new (self, msg, timeout, task);
-
-    bytes_sent = g_socket_send (self->priv->socket,
-                                (const gchar *) msg->data,
-                                msg->len,
-                                cancellable,
-                                &error);
-    netlink_message_free (msg);
-
-    if (bytes_sent < 0)
-        transaction_complete_with_error (tr, error);
-
-    g_object_unref (task);
-}
-
-/*****************************************************************************/
-
-QmiNetPortManager *
-qmi_net_port_manager_new (GError **error)
-{
-    QmiNetPortManager *self;
-    gint               socket_fd;
-    GSocket           *gsocket;
-    GError            *inner_error = NULL;
-
-    socket_fd = socket (AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE);
-    if (socket_fd < 0) {
-        g_set_error (error,
-                     QMI_CORE_ERROR,
-                     QMI_CORE_ERROR_FAILED,
-                     "Failed to create netlink socket");
-        return NULL;
-    }
-
-    gsocket = g_socket_new_from_fd (socket_fd, &inner_error);
-    if (inner_error) {
-        g_debug ("Could not create socket: %s", inner_error->message);
-        close (socket_fd);
-        g_propagate_error (error, inner_error);
-        return NULL;
-    }
-
-    self = g_object_new (QMI_TYPE_NET_PORT_MANAGER, NULL);
-    self->priv->socket = gsocket;
-    self->priv->source = g_socket_create_source (self->priv->socket,
-                                                 G_IO_IN | G_IO_ERR | G_IO_HUP,
-                                                 NULL);
-    g_source_set_callback (self->priv->source,
-                           (GSourceFunc) netlink_message_cb,
-                           self,
-                           NULL);
-    g_source_attach (self->priv->source, g_main_context_get_thread_default ());
-
-    self->priv->current_sequence_id = 0;
-    self->priv->transactions =
-        g_hash_table_new_full (g_direct_hash,
-                               g_direct_equal,
-                               NULL,
-                               (GDestroyNotify) transaction_free);
-    return self;
+    return QMI_NET_PORT_MANAGER_GET_CLASS (self)->del_link_finish (self, res, error);
 }
 
 /*****************************************************************************/
@@ -642,33 +84,9 @@ qmi_net_port_manager_new (GError **error)
 static void
 qmi_net_port_manager_init (QmiNetPortManager *self)
 {
-    self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
-                                              QMI_TYPE_NET_PORT_MANAGER,
-                                              QmiNetPortManagerPrivate);
-}
-
-static void
-dispose (GObject *object)
-{
-    QmiNetPortManager *self = QMI_NET_PORT_MANAGER (object);
-
-    g_assert (g_hash_table_size (self->priv->transactions) == 0);
-
-    g_hash_table_unref (self->priv->transactions);
-
-    g_source_destroy (self->priv->source);
-    g_clear_pointer (&self->priv->source, g_source_unref);
-    g_clear_object (&self->priv->socket);
-
-    G_OBJECT_CLASS (qmi_net_port_manager_parent_class)->dispose (object);
 }
 
 static void
 qmi_net_port_manager_class_init (QmiNetPortManagerClass *klass)
 {
-    GObjectClass *object_class = G_OBJECT_CLASS (klass);
-
-    g_type_class_add_private (object_class, sizeof (QmiNetPortManagerPrivate));
-
-    object_class->dispose = dispose;
 }
diff --git a/src/libqmi-glib/qmi-net-port-manager.h b/src/libqmi-glib/qmi-net-port-manager.h
index 8e0fd15..1c84c0b 100644
--- a/src/libqmi-glib/qmi-net-port-manager.h
+++ b/src/libqmi-glib/qmi-net-port-manager.h
@@ -17,8 +17,9 @@
  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301 USA.
  *
- * Copyright (C) 2020 Eric Caruso <ejcaruso@chromium.org>
- * Copyright (C) 2020 Andrew Lassalle <andrewlassalle@chromium.org>
+ * Copyright (C) 2020-2021 Eric Caruso <ejcaruso@chromium.org>
+ * Copyright (C) 2020-2021 Andrew Lassalle <andrewlassalle@chromium.org>
+ * Copyright (C) 2021 Aleksander Morgado <aleksander@aleksander.es>
  */
 
 #ifndef _LIBQMI_GLIB_QMI_NET_PORT_MANAGER_H_
@@ -34,51 +35,65 @@
 #define QMI_IS_NET_PORT_MANAGER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  QMI_TYPE_NET_PORT_MANAGER))
 #define QMI_NET_PORT_MANAGER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  QMI_TYPE_NET_PORT_MANAGER, QmiNetPortManagerClass))
 
-typedef struct _QmiNetPortManager        QmiNetPortManager;
-typedef struct _QmiNetPortManagerClass   QmiNetPortManagerClass;
-typedef struct _QmiNetPortManagerPrivate QmiNetPortManagerPrivate;
+typedef struct _QmiNetPortManager      QmiNetPortManager;
+typedef struct _QmiNetPortManagerClass QmiNetPortManagerClass;
 
 struct _QmiNetPortManager {
-    /*< private >*/
-    GObject                   parent;
-    QmiNetPortManagerPrivate *priv;
+    GObject parent;
 };
 
 struct _QmiNetPortManagerClass {
-    /*< private >*/
     GObjectClass parent;
+
+    void     (* add_link)        (QmiNetPortManager    *self,
+                                  guint                 mux_id,
+                                  const gchar          *base_ifname,
+                                  const gchar          *ifname_prefix,
+                                  guint                 timeout,
+                                  GCancellable         *cancellable,
+                                  GAsyncReadyCallback   callback,
+                                  gpointer              user_data);
+    gchar *  (* add_link_finish) (QmiNetPortManager    *self,
+                                  guint                *mux_id,
+                                  GAsyncResult         *res,
+                                  GError              **error);
+
+    void     (* del_link)        (QmiNetPortManager    *self,
+                                  const gchar          *ifname,
+                                  guint                 timeout,
+                                  GCancellable         *cancellable,
+                                  GAsyncReadyCallback   callback,
+                                  gpointer              user_data);
+    gboolean (* del_link_finish) (QmiNetPortManager    *self,
+                                  GAsyncResult         *res,
+                                  GError              **error);
 };
 
 GType qmi_net_port_manager_get_type (void);
 G_DEFINE_AUTOPTR_CLEANUP_FUNC (QmiNetPortManager, g_object_unref)
 
-QmiNetPortManager *qmi_net_port_manager_new (GError **error);
-
-/* Requests to add a link for the given mux_id. */
-void qmi_net_port_manager_add_link (QmiNetPortManager   *self,
-                                    guint                mux_id,
-                                    const gchar         *base_ifname,
-                                    const gchar         *ifname_prefix,
-                                    guint                timeout,
-                                    GCancellable        *cancellable,
-                                    GAsyncReadyCallback  callback,
-                                    gpointer             user_data);
-
-/* Returns the name of the new link. */
-gchar *qmi_net_port_manager_add_link_finish (QmiNetPortManager *self,
-                                             guint             *mux_id,
-                                             GAsyncResult      *res,
-                                             GError **          error);
 
-void qmi_net_port_manager_del_link (QmiNetPortManager   *self,
-                                    const gchar         *ifname,
-                                    guint                timeout,
-                                    GCancellable        *cancellable,
-                                    GAsyncReadyCallback  callback,
-                                    gpointer             user_data);
+void      qmi_net_port_manager_add_link        (QmiNetPortManager    *self,
+                                                guint                 mux_id,
+                                                const gchar          *base_ifname,
+                                                const gchar          *ifname_prefix,
+                                                guint                 timeout,
+                                                GCancellable         *cancellable,
+                                                GAsyncReadyCallback   callback,
+                                                gpointer              user_data);
+gchar    *qmi_net_port_manager_add_link_finish (QmiNetPortManager    *self,
+                                                guint                *mux_id,
+                                                GAsyncResult         *res,
+                                                GError              **error);
 
-gboolean qmi_net_port_manager_del_link_finish (QmiNetPortManager *self,
-                                               GAsyncResult      *res,
-                                               GError **          error);
+void      qmi_net_port_manager_del_link        (QmiNetPortManager    *self,
+                                                const gchar          *ifname,
+                                                guint                 timeout,
+                                                GCancellable         *cancellable,
+                                                GAsyncReadyCallback   callback,
+                                                gpointer              user_data);
+gboolean  qmi_net_port_manager_del_link_finish (QmiNetPortManager    *self,
+                                                GAsyncResult         *res,
+                                                GError              **error);
 
 #endif /* _LIBQMI_GLIB_QMI_NET_PORT_MANAGER_H_ */