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-rw-r--r--net/batman-adv/hard-interface.c1022
1 files changed, 1022 insertions, 0 deletions
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
new file mode 100644
index 000000000..24c9c0c3f
--- /dev/null
+++ b/net/batman-adv/hard-interface.c
@@ -0,0 +1,1022 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) B.A.T.M.A.N. contributors:
+ *
+ * Marek Lindner, Simon Wunderlich
+ */
+
+#include "hard-interface.h"
+#include "main.h"
+
+#include <linux/atomic.h>
+#include <linux/byteorder/generic.h>
+#include <linux/container_of.h>
+#include <linux/errno.h>
+#include <linux/gfp.h>
+#include <linux/if.h>
+#include <linux/if_arp.h>
+#include <linux/if_ether.h>
+#include <linux/kref.h>
+#include <linux/limits.h>
+#include <linux/list.h>
+#include <linux/minmax.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/printk.h>
+#include <linux/rculist.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <net/net_namespace.h>
+#include <net/rtnetlink.h>
+#include <uapi/linux/batadv_packet.h>
+
+#include "bat_v.h"
+#include "bridge_loop_avoidance.h"
+#include "distributed-arp-table.h"
+#include "gateway_client.h"
+#include "log.h"
+#include "originator.h"
+#include "send.h"
+#include "soft-interface.h"
+#include "translation-table.h"
+
+/**
+ * batadv_hardif_release() - release hard interface from lists and queue for
+ * free after rcu grace period
+ * @ref: kref pointer of the hard interface
+ */
+void batadv_hardif_release(struct kref *ref)
+{
+ struct batadv_hard_iface *hard_iface;
+
+ hard_iface = container_of(ref, struct batadv_hard_iface, refcount);
+ dev_put(hard_iface->net_dev);
+
+ kfree_rcu(hard_iface, rcu);
+}
+
+/**
+ * batadv_hardif_get_by_netdev() - Get hard interface object of a net_device
+ * @net_dev: net_device to search for
+ *
+ * Return: batadv_hard_iface of net_dev (with increased refcnt), NULL on errors
+ */
+struct batadv_hard_iface *
+batadv_hardif_get_by_netdev(const struct net_device *net_dev)
+{
+ struct batadv_hard_iface *hard_iface;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if (hard_iface->net_dev == net_dev &&
+ kref_get_unless_zero(&hard_iface->refcount))
+ goto out;
+ }
+
+ hard_iface = NULL;
+
+out:
+ rcu_read_unlock();
+ return hard_iface;
+}
+
+/**
+ * batadv_getlink_net() - return link net namespace (of use fallback)
+ * @netdev: net_device to check
+ * @fallback_net: return in case get_link_net is not available for @netdev
+ *
+ * Return: result of rtnl_link_ops->get_link_net or @fallback_net
+ */
+static struct net *batadv_getlink_net(const struct net_device *netdev,
+ struct net *fallback_net)
+{
+ if (!netdev->rtnl_link_ops)
+ return fallback_net;
+
+ if (!netdev->rtnl_link_ops->get_link_net)
+ return fallback_net;
+
+ return netdev->rtnl_link_ops->get_link_net(netdev);
+}
+
+/**
+ * batadv_mutual_parents() - check if two devices are each others parent
+ * @dev1: 1st net dev
+ * @net1: 1st devices netns
+ * @dev2: 2nd net dev
+ * @net2: 2nd devices netns
+ *
+ * veth devices come in pairs and each is the parent of the other!
+ *
+ * Return: true if the devices are each others parent, otherwise false
+ */
+static bool batadv_mutual_parents(const struct net_device *dev1,
+ struct net *net1,
+ const struct net_device *dev2,
+ struct net *net2)
+{
+ int dev1_parent_iflink = dev_get_iflink(dev1);
+ int dev2_parent_iflink = dev_get_iflink(dev2);
+ const struct net *dev1_parent_net;
+ const struct net *dev2_parent_net;
+
+ dev1_parent_net = batadv_getlink_net(dev1, net1);
+ dev2_parent_net = batadv_getlink_net(dev2, net2);
+
+ if (!dev1_parent_iflink || !dev2_parent_iflink)
+ return false;
+
+ return (dev1_parent_iflink == dev2->ifindex) &&
+ (dev2_parent_iflink == dev1->ifindex) &&
+ net_eq(dev1_parent_net, net2) &&
+ net_eq(dev2_parent_net, net1);
+}
+
+/**
+ * batadv_is_on_batman_iface() - check if a device is a batman iface descendant
+ * @net_dev: the device to check
+ *
+ * If the user creates any virtual device on top of a batman-adv interface, it
+ * is important to prevent this new interface from being used to create a new
+ * mesh network (this behaviour would lead to a batman-over-batman
+ * configuration). This function recursively checks all the fathers of the
+ * device passed as argument looking for a batman-adv soft interface.
+ *
+ * Return: true if the device is descendant of a batman-adv mesh interface (or
+ * if it is a batman-adv interface itself), false otherwise
+ */
+static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
+{
+ struct net *net = dev_net(net_dev);
+ struct net_device *parent_dev;
+ struct net *parent_net;
+ int iflink;
+ bool ret;
+
+ /* check if this is a batman-adv mesh interface */
+ if (batadv_softif_is_valid(net_dev))
+ return true;
+
+ iflink = dev_get_iflink(net_dev);
+ if (iflink == 0)
+ return false;
+
+ parent_net = batadv_getlink_net(net_dev, net);
+
+ /* iflink to itself, most likely physical device */
+ if (net == parent_net && iflink == net_dev->ifindex)
+ return false;
+
+ /* recurse over the parent device */
+ parent_dev = __dev_get_by_index((struct net *)parent_net, iflink);
+ if (!parent_dev) {
+ pr_warn("Cannot find parent device. Skipping batadv-on-batadv check for %s\n",
+ net_dev->name);
+ return false;
+ }
+
+ if (batadv_mutual_parents(net_dev, net, parent_dev, parent_net))
+ return false;
+
+ ret = batadv_is_on_batman_iface(parent_dev);
+
+ return ret;
+}
+
+static bool batadv_is_valid_iface(const struct net_device *net_dev)
+{
+ if (net_dev->flags & IFF_LOOPBACK)
+ return false;
+
+ if (net_dev->type != ARPHRD_ETHER)
+ return false;
+
+ if (net_dev->addr_len != ETH_ALEN)
+ return false;
+
+ /* no batman over batman */
+ if (batadv_is_on_batman_iface(net_dev))
+ return false;
+
+ return true;
+}
+
+/**
+ * batadv_get_real_netdevice() - check if the given netdev struct is a virtual
+ * interface on top of another 'real' interface
+ * @netdev: the device to check
+ *
+ * Callers must hold the rtnl semaphore. You may want batadv_get_real_netdev()
+ * instead of this.
+ *
+ * Return: the 'real' net device or the original net device and NULL in case
+ * of an error.
+ */
+static struct net_device *batadv_get_real_netdevice(struct net_device *netdev)
+{
+ struct batadv_hard_iface *hard_iface = NULL;
+ struct net_device *real_netdev = NULL;
+ struct net *real_net;
+ struct net *net;
+ int iflink;
+
+ ASSERT_RTNL();
+
+ if (!netdev)
+ return NULL;
+
+ iflink = dev_get_iflink(netdev);
+ if (iflink == 0) {
+ dev_hold(netdev);
+ return netdev;
+ }
+
+ hard_iface = batadv_hardif_get_by_netdev(netdev);
+ if (!hard_iface || !hard_iface->soft_iface)
+ goto out;
+
+ net = dev_net(hard_iface->soft_iface);
+ real_net = batadv_getlink_net(netdev, net);
+
+ /* iflink to itself, most likely physical device */
+ if (net == real_net && netdev->ifindex == iflink) {
+ real_netdev = netdev;
+ dev_hold(real_netdev);
+ goto out;
+ }
+
+ real_netdev = dev_get_by_index(real_net, iflink);
+
+out:
+ batadv_hardif_put(hard_iface);
+ return real_netdev;
+}
+
+/**
+ * batadv_get_real_netdev() - check if the given net_device struct is a virtual
+ * interface on top of another 'real' interface
+ * @net_device: the device to check
+ *
+ * Return: the 'real' net device or the original net device and NULL in case
+ * of an error.
+ */
+struct net_device *batadv_get_real_netdev(struct net_device *net_device)
+{
+ struct net_device *real_netdev;
+
+ rtnl_lock();
+ real_netdev = batadv_get_real_netdevice(net_device);
+ rtnl_unlock();
+
+ return real_netdev;
+}
+
+/**
+ * batadv_is_wext_netdev() - check if the given net_device struct is a
+ * wext wifi interface
+ * @net_device: the device to check
+ *
+ * Return: true if the net device is a wext wireless device, false
+ * otherwise.
+ */
+static bool batadv_is_wext_netdev(struct net_device *net_device)
+{
+ if (!net_device)
+ return false;
+
+#ifdef CONFIG_WIRELESS_EXT
+ /* pre-cfg80211 drivers have to implement WEXT, so it is possible to
+ * check for wireless_handlers != NULL
+ */
+ if (net_device->wireless_handlers)
+ return true;
+#endif
+
+ return false;
+}
+
+/**
+ * batadv_is_cfg80211_netdev() - check if the given net_device struct is a
+ * cfg80211 wifi interface
+ * @net_device: the device to check
+ *
+ * Return: true if the net device is a cfg80211 wireless device, false
+ * otherwise.
+ */
+static bool batadv_is_cfg80211_netdev(struct net_device *net_device)
+{
+ if (!net_device)
+ return false;
+
+#if IS_ENABLED(CONFIG_CFG80211)
+ /* cfg80211 drivers have to set ieee80211_ptr */
+ if (net_device->ieee80211_ptr)
+ return true;
+#endif
+
+ return false;
+}
+
+/**
+ * batadv_wifi_flags_evaluate() - calculate wifi flags for net_device
+ * @net_device: the device to check
+ *
+ * Return: batadv_hard_iface_wifi_flags flags of the device
+ */
+static u32 batadv_wifi_flags_evaluate(struct net_device *net_device)
+{
+ u32 wifi_flags = 0;
+ struct net_device *real_netdev;
+
+ if (batadv_is_wext_netdev(net_device))
+ wifi_flags |= BATADV_HARDIF_WIFI_WEXT_DIRECT;
+
+ if (batadv_is_cfg80211_netdev(net_device))
+ wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
+
+ real_netdev = batadv_get_real_netdevice(net_device);
+ if (!real_netdev)
+ return wifi_flags;
+
+ if (real_netdev == net_device)
+ goto out;
+
+ if (batadv_is_wext_netdev(real_netdev))
+ wifi_flags |= BATADV_HARDIF_WIFI_WEXT_INDIRECT;
+
+ if (batadv_is_cfg80211_netdev(real_netdev))
+ wifi_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
+
+out:
+ dev_put(real_netdev);
+ return wifi_flags;
+}
+
+/**
+ * batadv_is_cfg80211_hardif() - check if the given hardif is a cfg80211 wifi
+ * interface
+ * @hard_iface: the device to check
+ *
+ * Return: true if the net device is a cfg80211 wireless device, false
+ * otherwise.
+ */
+bool batadv_is_cfg80211_hardif(struct batadv_hard_iface *hard_iface)
+{
+ u32 allowed_flags = 0;
+
+ allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_DIRECT;
+ allowed_flags |= BATADV_HARDIF_WIFI_CFG80211_INDIRECT;
+
+ return !!(hard_iface->wifi_flags & allowed_flags);
+}
+
+/**
+ * batadv_is_wifi_hardif() - check if the given hardif is a wifi interface
+ * @hard_iface: the device to check
+ *
+ * Return: true if the net device is a 802.11 wireless device, false otherwise.
+ */
+bool batadv_is_wifi_hardif(struct batadv_hard_iface *hard_iface)
+{
+ if (!hard_iface)
+ return false;
+
+ return hard_iface->wifi_flags != 0;
+}
+
+/**
+ * batadv_hardif_no_broadcast() - check whether (re)broadcast is necessary
+ * @if_outgoing: the outgoing interface checked and considered for (re)broadcast
+ * @orig_addr: the originator of this packet
+ * @orig_neigh: originator address of the forwarder we just got the packet from
+ * (NULL if we originated)
+ *
+ * Checks whether a packet needs to be (re)broadcasted on the given interface.
+ *
+ * Return:
+ * BATADV_HARDIF_BCAST_NORECIPIENT: No neighbor on interface
+ * BATADV_HARDIF_BCAST_DUPFWD: Just one neighbor, but it is the forwarder
+ * BATADV_HARDIF_BCAST_DUPORIG: Just one neighbor, but it is the originator
+ * BATADV_HARDIF_BCAST_OK: Several neighbors, must broadcast
+ */
+int batadv_hardif_no_broadcast(struct batadv_hard_iface *if_outgoing,
+ u8 *orig_addr, u8 *orig_neigh)
+{
+ struct batadv_hardif_neigh_node *hardif_neigh;
+ struct hlist_node *first;
+ int ret = BATADV_HARDIF_BCAST_OK;
+
+ rcu_read_lock();
+
+ /* 0 neighbors -> no (re)broadcast */
+ first = rcu_dereference(hlist_first_rcu(&if_outgoing->neigh_list));
+ if (!first) {
+ ret = BATADV_HARDIF_BCAST_NORECIPIENT;
+ goto out;
+ }
+
+ /* >1 neighbors -> (re)broadcast */
+ if (rcu_dereference(hlist_next_rcu(first)))
+ goto out;
+
+ hardif_neigh = hlist_entry(first, struct batadv_hardif_neigh_node,
+ list);
+
+ /* 1 neighbor, is the originator -> no rebroadcast */
+ if (orig_addr && batadv_compare_eth(hardif_neigh->orig, orig_addr)) {
+ ret = BATADV_HARDIF_BCAST_DUPORIG;
+ /* 1 neighbor, is the one we received from -> no rebroadcast */
+ } else if (orig_neigh &&
+ batadv_compare_eth(hardif_neigh->orig, orig_neigh)) {
+ ret = BATADV_HARDIF_BCAST_DUPFWD;
+ }
+
+out:
+ rcu_read_unlock();
+ return ret;
+}
+
+static struct batadv_hard_iface *
+batadv_hardif_get_active(const struct net_device *soft_iface)
+{
+ struct batadv_hard_iface *hard_iface;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if (hard_iface->soft_iface != soft_iface)
+ continue;
+
+ if (hard_iface->if_status == BATADV_IF_ACTIVE &&
+ kref_get_unless_zero(&hard_iface->refcount))
+ goto out;
+ }
+
+ hard_iface = NULL;
+
+out:
+ rcu_read_unlock();
+ return hard_iface;
+}
+
+static void batadv_primary_if_update_addr(struct batadv_priv *bat_priv,
+ struct batadv_hard_iface *oldif)
+{
+ struct batadv_hard_iface *primary_if;
+
+ primary_if = batadv_primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto out;
+
+ batadv_dat_init_own_addr(bat_priv, primary_if);
+ batadv_bla_update_orig_address(bat_priv, primary_if, oldif);
+out:
+ batadv_hardif_put(primary_if);
+}
+
+static void batadv_primary_if_select(struct batadv_priv *bat_priv,
+ struct batadv_hard_iface *new_hard_iface)
+{
+ struct batadv_hard_iface *curr_hard_iface;
+
+ ASSERT_RTNL();
+
+ if (new_hard_iface)
+ kref_get(&new_hard_iface->refcount);
+
+ curr_hard_iface = rcu_replace_pointer(bat_priv->primary_if,
+ new_hard_iface, 1);
+
+ if (!new_hard_iface)
+ goto out;
+
+ bat_priv->algo_ops->iface.primary_set(new_hard_iface);
+ batadv_primary_if_update_addr(bat_priv, curr_hard_iface);
+
+out:
+ batadv_hardif_put(curr_hard_iface);
+}
+
+static bool
+batadv_hardif_is_iface_up(const struct batadv_hard_iface *hard_iface)
+{
+ if (hard_iface->net_dev->flags & IFF_UP)
+ return true;
+
+ return false;
+}
+
+static void batadv_check_known_mac_addr(const struct net_device *net_dev)
+{
+ const struct batadv_hard_iface *hard_iface;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if (hard_iface->if_status != BATADV_IF_ACTIVE &&
+ hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
+ continue;
+
+ if (hard_iface->net_dev == net_dev)
+ continue;
+
+ if (!batadv_compare_eth(hard_iface->net_dev->dev_addr,
+ net_dev->dev_addr))
+ continue;
+
+ pr_warn("The newly added mac address (%pM) already exists on: %s\n",
+ net_dev->dev_addr, hard_iface->net_dev->name);
+ pr_warn("It is strongly recommended to keep mac addresses unique to avoid problems!\n");
+ }
+ rcu_read_unlock();
+}
+
+/**
+ * batadv_hardif_recalc_extra_skbroom() - Recalculate skbuff extra head/tailroom
+ * @soft_iface: netdev struct of the mesh interface
+ */
+static void batadv_hardif_recalc_extra_skbroom(struct net_device *soft_iface)
+{
+ const struct batadv_hard_iface *hard_iface;
+ unsigned short lower_header_len = ETH_HLEN;
+ unsigned short lower_headroom = 0;
+ unsigned short lower_tailroom = 0;
+ unsigned short needed_headroom;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
+ continue;
+
+ if (hard_iface->soft_iface != soft_iface)
+ continue;
+
+ lower_header_len = max_t(unsigned short, lower_header_len,
+ hard_iface->net_dev->hard_header_len);
+
+ lower_headroom = max_t(unsigned short, lower_headroom,
+ hard_iface->net_dev->needed_headroom);
+
+ lower_tailroom = max_t(unsigned short, lower_tailroom,
+ hard_iface->net_dev->needed_tailroom);
+ }
+ rcu_read_unlock();
+
+ needed_headroom = lower_headroom + (lower_header_len - ETH_HLEN);
+ needed_headroom += batadv_max_header_len();
+
+ /* fragmentation headers don't strip the unicast/... header */
+ needed_headroom += sizeof(struct batadv_frag_packet);
+
+ soft_iface->needed_headroom = needed_headroom;
+ soft_iface->needed_tailroom = lower_tailroom;
+}
+
+/**
+ * batadv_hardif_min_mtu() - Calculate maximum MTU for soft interface
+ * @soft_iface: netdev struct of the soft interface
+ *
+ * Return: MTU for the soft-interface (limited by the minimal MTU of all active
+ * slave interfaces)
+ */
+int batadv_hardif_min_mtu(struct net_device *soft_iface)
+{
+ struct batadv_priv *bat_priv = netdev_priv(soft_iface);
+ const struct batadv_hard_iface *hard_iface;
+ int min_mtu = INT_MAX;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if (hard_iface->if_status != BATADV_IF_ACTIVE &&
+ hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
+ continue;
+
+ if (hard_iface->soft_iface != soft_iface)
+ continue;
+
+ min_mtu = min_t(int, hard_iface->net_dev->mtu, min_mtu);
+ }
+ rcu_read_unlock();
+
+ if (atomic_read(&bat_priv->fragmentation) == 0)
+ goto out;
+
+ /* with fragmentation enabled the maximum size of internally generated
+ * packets such as translation table exchanges or tvlv containers, etc
+ * has to be calculated
+ */
+ min_mtu = min_t(int, min_mtu, BATADV_FRAG_MAX_FRAG_SIZE);
+ min_mtu -= sizeof(struct batadv_frag_packet);
+ min_mtu *= BATADV_FRAG_MAX_FRAGMENTS;
+
+out:
+ /* report to the other components the maximum amount of bytes that
+ * batman-adv can send over the wire (without considering the payload
+ * overhead). For example, this value is used by TT to compute the
+ * maximum local table size
+ */
+ atomic_set(&bat_priv->packet_size_max, min_mtu);
+
+ /* the real soft-interface MTU is computed by removing the payload
+ * overhead from the maximum amount of bytes that was just computed.
+ *
+ * However batman-adv does not support MTUs bigger than ETH_DATA_LEN
+ */
+ return min_t(int, min_mtu - batadv_max_header_len(), ETH_DATA_LEN);
+}
+
+/**
+ * batadv_update_min_mtu() - Adjusts the MTU if a new interface with a smaller
+ * MTU appeared
+ * @soft_iface: netdev struct of the soft interface
+ */
+void batadv_update_min_mtu(struct net_device *soft_iface)
+{
+ struct batadv_priv *bat_priv = netdev_priv(soft_iface);
+ int limit_mtu;
+ int mtu;
+
+ mtu = batadv_hardif_min_mtu(soft_iface);
+
+ if (bat_priv->mtu_set_by_user)
+ limit_mtu = bat_priv->mtu_set_by_user;
+ else
+ limit_mtu = ETH_DATA_LEN;
+
+ mtu = min(mtu, limit_mtu);
+ dev_set_mtu(soft_iface, mtu);
+
+ /* Check if the local translate table should be cleaned up to match a
+ * new (and smaller) MTU.
+ */
+ batadv_tt_local_resize_to_mtu(soft_iface);
+}
+
+static void
+batadv_hardif_activate_interface(struct batadv_hard_iface *hard_iface)
+{
+ struct batadv_priv *bat_priv;
+ struct batadv_hard_iface *primary_if = NULL;
+
+ if (hard_iface->if_status != BATADV_IF_INACTIVE)
+ goto out;
+
+ bat_priv = netdev_priv(hard_iface->soft_iface);
+
+ bat_priv->algo_ops->iface.update_mac(hard_iface);
+ hard_iface->if_status = BATADV_IF_TO_BE_ACTIVATED;
+
+ /* the first active interface becomes our primary interface or
+ * the next active interface after the old primary interface was removed
+ */
+ primary_if = batadv_primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ batadv_primary_if_select(bat_priv, hard_iface);
+
+ batadv_info(hard_iface->soft_iface, "Interface activated: %s\n",
+ hard_iface->net_dev->name);
+
+ batadv_update_min_mtu(hard_iface->soft_iface);
+
+ if (bat_priv->algo_ops->iface.activate)
+ bat_priv->algo_ops->iface.activate(hard_iface);
+
+out:
+ batadv_hardif_put(primary_if);
+}
+
+static void
+batadv_hardif_deactivate_interface(struct batadv_hard_iface *hard_iface)
+{
+ if (hard_iface->if_status != BATADV_IF_ACTIVE &&
+ hard_iface->if_status != BATADV_IF_TO_BE_ACTIVATED)
+ return;
+
+ hard_iface->if_status = BATADV_IF_INACTIVE;
+
+ batadv_info(hard_iface->soft_iface, "Interface deactivated: %s\n",
+ hard_iface->net_dev->name);
+
+ batadv_update_min_mtu(hard_iface->soft_iface);
+}
+
+/**
+ * batadv_hardif_enable_interface() - Enslave hard interface to soft interface
+ * @hard_iface: hard interface to add to soft interface
+ * @soft_iface: netdev struct of the mesh interface
+ *
+ * Return: 0 on success or negative error number in case of failure
+ */
+int batadv_hardif_enable_interface(struct batadv_hard_iface *hard_iface,
+ struct net_device *soft_iface)
+{
+ struct batadv_priv *bat_priv;
+ __be16 ethertype = htons(ETH_P_BATMAN);
+ int max_header_len = batadv_max_header_len();
+ int ret;
+
+ if (hard_iface->net_dev->mtu < ETH_MIN_MTU + max_header_len)
+ return -EINVAL;
+
+ if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
+ goto out;
+
+ kref_get(&hard_iface->refcount);
+
+ dev_hold(soft_iface);
+ hard_iface->soft_iface = soft_iface;
+ bat_priv = netdev_priv(hard_iface->soft_iface);
+
+ ret = netdev_master_upper_dev_link(hard_iface->net_dev,
+ soft_iface, NULL, NULL, NULL);
+ if (ret)
+ goto err_dev;
+
+ ret = bat_priv->algo_ops->iface.enable(hard_iface);
+ if (ret < 0)
+ goto err_upper;
+
+ hard_iface->if_status = BATADV_IF_INACTIVE;
+
+ kref_get(&hard_iface->refcount);
+ hard_iface->batman_adv_ptype.type = ethertype;
+ hard_iface->batman_adv_ptype.func = batadv_batman_skb_recv;
+ hard_iface->batman_adv_ptype.dev = hard_iface->net_dev;
+ dev_add_pack(&hard_iface->batman_adv_ptype);
+
+ batadv_info(hard_iface->soft_iface, "Adding interface: %s\n",
+ hard_iface->net_dev->name);
+
+ if (atomic_read(&bat_priv->fragmentation) &&
+ hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
+ batadv_info(hard_iface->soft_iface,
+ "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to %i would solve the problem.\n",
+ hard_iface->net_dev->name, hard_iface->net_dev->mtu,
+ ETH_DATA_LEN + max_header_len);
+
+ if (!atomic_read(&bat_priv->fragmentation) &&
+ hard_iface->net_dev->mtu < ETH_DATA_LEN + max_header_len)
+ batadv_info(hard_iface->soft_iface,
+ "The MTU of interface %s is too small (%i) to handle the transport of batman-adv packets. If you experience problems getting traffic through try increasing the MTU to %i.\n",
+ hard_iface->net_dev->name, hard_iface->net_dev->mtu,
+ ETH_DATA_LEN + max_header_len);
+
+ if (batadv_hardif_is_iface_up(hard_iface))
+ batadv_hardif_activate_interface(hard_iface);
+ else
+ batadv_err(hard_iface->soft_iface,
+ "Not using interface %s (retrying later): interface not active\n",
+ hard_iface->net_dev->name);
+
+ batadv_hardif_recalc_extra_skbroom(soft_iface);
+
+ if (bat_priv->algo_ops->iface.enabled)
+ bat_priv->algo_ops->iface.enabled(hard_iface);
+
+out:
+ return 0;
+
+err_upper:
+ netdev_upper_dev_unlink(hard_iface->net_dev, soft_iface);
+err_dev:
+ hard_iface->soft_iface = NULL;
+ dev_put(soft_iface);
+ batadv_hardif_put(hard_iface);
+ return ret;
+}
+
+/**
+ * batadv_hardif_cnt() - get number of interfaces enslaved to soft interface
+ * @soft_iface: soft interface to check
+ *
+ * This function is only using RCU for locking - the result can therefore be
+ * off when another function is modifying the list at the same time. The
+ * caller can use the rtnl_lock to make sure that the count is accurate.
+ *
+ * Return: number of connected/enslaved hard interfaces
+ */
+static size_t batadv_hardif_cnt(const struct net_device *soft_iface)
+{
+ struct batadv_hard_iface *hard_iface;
+ size_t count = 0;
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+ if (hard_iface->soft_iface != soft_iface)
+ continue;
+
+ count++;
+ }
+ rcu_read_unlock();
+
+ return count;
+}
+
+/**
+ * batadv_hardif_disable_interface() - Remove hard interface from soft interface
+ * @hard_iface: hard interface to be removed
+ */
+void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface)
+{
+ struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+ struct batadv_hard_iface *primary_if = NULL;
+
+ batadv_hardif_deactivate_interface(hard_iface);
+
+ if (hard_iface->if_status != BATADV_IF_INACTIVE)
+ goto out;
+
+ batadv_info(hard_iface->soft_iface, "Removing interface: %s\n",
+ hard_iface->net_dev->name);
+ dev_remove_pack(&hard_iface->batman_adv_ptype);
+ batadv_hardif_put(hard_iface);
+
+ primary_if = batadv_primary_if_get_selected(bat_priv);
+ if (hard_iface == primary_if) {
+ struct batadv_hard_iface *new_if;
+
+ new_if = batadv_hardif_get_active(hard_iface->soft_iface);
+ batadv_primary_if_select(bat_priv, new_if);
+
+ batadv_hardif_put(new_if);
+ }
+
+ bat_priv->algo_ops->iface.disable(hard_iface);
+ hard_iface->if_status = BATADV_IF_NOT_IN_USE;
+
+ /* delete all references to this hard_iface */
+ batadv_purge_orig_ref(bat_priv);
+ batadv_purge_outstanding_packets(bat_priv, hard_iface);
+ dev_put(hard_iface->soft_iface);
+
+ netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
+ batadv_hardif_recalc_extra_skbroom(hard_iface->soft_iface);
+
+ /* nobody uses this interface anymore */
+ if (batadv_hardif_cnt(hard_iface->soft_iface) <= 1)
+ batadv_gw_check_client_stop(bat_priv);
+
+ hard_iface->soft_iface = NULL;
+ batadv_hardif_put(hard_iface);
+
+out:
+ batadv_hardif_put(primary_if);
+}
+
+static struct batadv_hard_iface *
+batadv_hardif_add_interface(struct net_device *net_dev)
+{
+ struct batadv_hard_iface *hard_iface;
+
+ ASSERT_RTNL();
+
+ if (!batadv_is_valid_iface(net_dev))
+ goto out;
+
+ dev_hold(net_dev);
+
+ hard_iface = kzalloc(sizeof(*hard_iface), GFP_ATOMIC);
+ if (!hard_iface)
+ goto release_dev;
+
+ hard_iface->net_dev = net_dev;
+ hard_iface->soft_iface = NULL;
+ hard_iface->if_status = BATADV_IF_NOT_IN_USE;
+
+ INIT_LIST_HEAD(&hard_iface->list);
+ INIT_HLIST_HEAD(&hard_iface->neigh_list);
+
+ mutex_init(&hard_iface->bat_iv.ogm_buff_mutex);
+ spin_lock_init(&hard_iface->neigh_list_lock);
+ kref_init(&hard_iface->refcount);
+
+ hard_iface->num_bcasts = BATADV_NUM_BCASTS_DEFAULT;
+ hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
+ if (batadv_is_wifi_hardif(hard_iface))
+ hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
+
+ atomic_set(&hard_iface->hop_penalty, 0);
+
+ batadv_v_hardif_init(hard_iface);
+
+ batadv_check_known_mac_addr(hard_iface->net_dev);
+ kref_get(&hard_iface->refcount);
+ list_add_tail_rcu(&hard_iface->list, &batadv_hardif_list);
+ batadv_hardif_generation++;
+
+ return hard_iface;
+
+release_dev:
+ dev_put(net_dev);
+out:
+ return NULL;
+}
+
+static void batadv_hardif_remove_interface(struct batadv_hard_iface *hard_iface)
+{
+ ASSERT_RTNL();
+
+ /* first deactivate interface */
+ if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
+ batadv_hardif_disable_interface(hard_iface);
+
+ if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
+ return;
+
+ hard_iface->if_status = BATADV_IF_TO_BE_REMOVED;
+ batadv_hardif_put(hard_iface);
+}
+
+/**
+ * batadv_hard_if_event_softif() - Handle events for soft interfaces
+ * @event: NETDEV_* event to handle
+ * @net_dev: net_device which generated an event
+ *
+ * Return: NOTIFY_* result
+ */
+static int batadv_hard_if_event_softif(unsigned long event,
+ struct net_device *net_dev)
+{
+ struct batadv_priv *bat_priv;
+
+ switch (event) {
+ case NETDEV_REGISTER:
+ bat_priv = netdev_priv(net_dev);
+ batadv_softif_create_vlan(bat_priv, BATADV_NO_FLAGS);
+ break;
+ }
+
+ return NOTIFY_DONE;
+}
+
+static int batadv_hard_if_event(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ struct net_device *net_dev = netdev_notifier_info_to_dev(ptr);
+ struct batadv_hard_iface *hard_iface;
+ struct batadv_hard_iface *primary_if = NULL;
+ struct batadv_priv *bat_priv;
+
+ if (batadv_softif_is_valid(net_dev))
+ return batadv_hard_if_event_softif(event, net_dev);
+
+ hard_iface = batadv_hardif_get_by_netdev(net_dev);
+ if (!hard_iface && (event == NETDEV_REGISTER ||
+ event == NETDEV_POST_TYPE_CHANGE))
+ hard_iface = batadv_hardif_add_interface(net_dev);
+
+ if (!hard_iface)
+ goto out;
+
+ switch (event) {
+ case NETDEV_UP:
+ batadv_hardif_activate_interface(hard_iface);
+ break;
+ case NETDEV_GOING_DOWN:
+ case NETDEV_DOWN:
+ batadv_hardif_deactivate_interface(hard_iface);
+ break;
+ case NETDEV_UNREGISTER:
+ case NETDEV_PRE_TYPE_CHANGE:
+ list_del_rcu(&hard_iface->list);
+ batadv_hardif_generation++;
+
+ batadv_hardif_remove_interface(hard_iface);
+ break;
+ case NETDEV_CHANGEMTU:
+ if (hard_iface->soft_iface)
+ batadv_update_min_mtu(hard_iface->soft_iface);
+ break;
+ case NETDEV_CHANGEADDR:
+ if (hard_iface->if_status == BATADV_IF_NOT_IN_USE)
+ goto hardif_put;
+
+ batadv_check_known_mac_addr(hard_iface->net_dev);
+
+ bat_priv = netdev_priv(hard_iface->soft_iface);
+ bat_priv->algo_ops->iface.update_mac(hard_iface);
+
+ primary_if = batadv_primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto hardif_put;
+
+ if (hard_iface == primary_if)
+ batadv_primary_if_update_addr(bat_priv, NULL);
+ break;
+ case NETDEV_CHANGEUPPER:
+ hard_iface->wifi_flags = batadv_wifi_flags_evaluate(net_dev);
+ if (batadv_is_wifi_hardif(hard_iface))
+ hard_iface->num_bcasts = BATADV_NUM_BCASTS_WIRELESS;
+ break;
+ default:
+ break;
+ }
+
+hardif_put:
+ batadv_hardif_put(hard_iface);
+out:
+ batadv_hardif_put(primary_if);
+ return NOTIFY_DONE;
+}
+
+struct notifier_block batadv_hard_if_notifier = {
+ .notifier_call = batadv_hard_if_event,
+};