Merge branch 'pcmcia' of git://git.armlinux.org.uk/~rmk/linux-arm
[cascardo/linux.git] / net / batman-adv / bat_iv_ogm.c
index 19b0abd..e2d18d0 100644 (file)
@@ -35,6 +35,7 @@
 #include <linux/list.h>
 #include <linux/lockdep.h>
 #include <linux/netdevice.h>
+#include <linux/netlink.h>
 #include <linux/pkt_sched.h>
 #include <linux/printk.h>
 #include <linux/random.h>
 #include <linux/string.h>
 #include <linux/types.h>
 #include <linux/workqueue.h>
+#include <net/genetlink.h>
+#include <net/netlink.h>
+#include <uapi/linux/batman_adv.h>
 
 #include "bat_algo.h"
 #include "bitarray.h"
+#include "gateway_client.h"
 #include "hard-interface.h"
 #include "hash.h"
 #include "log.h"
+#include "netlink.h"
 #include "network-coding.h"
 #include "originator.h"
 #include "packet.h"
@@ -318,17 +324,18 @@ batadv_iv_ogm_orig_get(struct batadv_priv *bat_priv, const u8 *addr)
        if (!orig_node->bat_iv.bcast_own_sum)
                goto free_orig_node;
 
+       kref_get(&orig_node->refcount);
        hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
                                     batadv_choose_orig, orig_node,
                                     &orig_node->hash_entry);
        if (hash_added != 0)
-               goto free_orig_node;
+               goto free_orig_node_hash;
 
        return orig_node;
 
-free_orig_node:
-       /* free twice, as batadv_orig_node_new sets refcount to 2 */
+free_orig_node_hash:
        batadv_orig_node_put(orig_node);
+free_orig_node:
        batadv_orig_node_put(orig_node);
 
        return NULL;
@@ -528,36 +535,25 @@ static void batadv_iv_ogm_send_to_if(struct batadv_forw_packet *forw_packet,
 static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet)
 {
        struct net_device *soft_iface;
-       struct batadv_priv *bat_priv;
-       struct batadv_hard_iface *primary_if = NULL;
 
        if (!forw_packet->if_incoming) {
                pr_err("Error - can't forward packet: incoming iface not specified\n");
-               goto out;
+               return;
        }
 
        soft_iface = forw_packet->if_incoming->soft_iface;
-       bat_priv = netdev_priv(soft_iface);
 
        if (WARN_ON(!forw_packet->if_outgoing))
-               goto out;
+               return;
 
        if (WARN_ON(forw_packet->if_outgoing->soft_iface != soft_iface))
-               goto out;
+               return;
 
        if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE)
-               goto out;
-
-       primary_if = batadv_primary_if_get_selected(bat_priv);
-       if (!primary_if)
-               goto out;
+               return;
 
        /* only for one specific outgoing interface */
        batadv_iv_ogm_send_to_if(forw_packet, forw_packet->if_outgoing);
-
-out:
-       if (primary_if)
-               batadv_hardif_put(primary_if);
 }
 
 /**
@@ -685,19 +681,12 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
        struct batadv_forw_packet *forw_packet_aggr;
        unsigned char *skb_buff;
        unsigned int skb_size;
+       atomic_t *queue_left = own_packet ? NULL : &bat_priv->batman_queue_left;
 
-       /* own packet should always be scheduled */
-       if (!own_packet) {
-               if (!batadv_atomic_dec_not_zero(&bat_priv->batman_queue_left)) {
-                       batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
-                                  "batman packet queue full\n");
-                       return;
-               }
-       }
-
-       forw_packet_aggr = kmalloc(sizeof(*forw_packet_aggr), GFP_ATOMIC);
+       forw_packet_aggr = batadv_forw_packet_alloc(if_incoming, if_outgoing,
+                                                   queue_left, bat_priv);
        if (!forw_packet_aggr)
-               goto out_nomem;
+               return;
 
        if (atomic_read(&bat_priv->aggregated_ogms) &&
            packet_len < BATADV_MAX_AGGREGATION_BYTES)
@@ -708,8 +697,11 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
        skb_size += ETH_HLEN;
 
        forw_packet_aggr->skb = netdev_alloc_skb_ip_align(NULL, skb_size);
-       if (!forw_packet_aggr->skb)
-               goto out_free_forw_packet;
+       if (!forw_packet_aggr->skb) {
+               batadv_forw_packet_free(forw_packet_aggr);
+               return;
+       }
+
        forw_packet_aggr->skb->priority = TC_PRIO_CONTROL;
        skb_reserve(forw_packet_aggr->skb, ETH_HLEN);
 
@@ -717,12 +709,7 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
        forw_packet_aggr->packet_len = packet_len;
        memcpy(skb_buff, packet_buff, packet_len);
 
-       kref_get(&if_incoming->refcount);
-       kref_get(&if_outgoing->refcount);
        forw_packet_aggr->own = own_packet;
-       forw_packet_aggr->if_incoming = if_incoming;
-       forw_packet_aggr->if_outgoing = if_outgoing;
-       forw_packet_aggr->num_packets = 0;
        forw_packet_aggr->direct_link_flags = BATADV_NO_FLAGS;
        forw_packet_aggr->send_time = send_time;
 
@@ -741,13 +728,6 @@ static void batadv_iv_ogm_aggregate_new(const unsigned char *packet_buff,
        queue_delayed_work(batadv_event_workqueue,
                           &forw_packet_aggr->delayed_work,
                           send_time - jiffies);
-
-       return;
-out_free_forw_packet:
-       kfree(forw_packet_aggr);
-out_nomem:
-       if (!own_packet)
-               atomic_inc(&bat_priv->batman_queue_left);
 }
 
 /* aggregate a new packet into the existing ogm packet */
@@ -1830,10 +1810,6 @@ static void batadv_iv_send_outstanding_bat_ogm_packet(struct work_struct *work)
                batadv_iv_ogm_schedule(forw_packet->if_incoming);
 
 out:
-       /* don't count own packet */
-       if (!forw_packet->own)
-               atomic_inc(&bat_priv->batman_queue_left);
-
        batadv_forw_packet_free(forw_packet);
 }
 
@@ -1879,6 +1855,7 @@ static int batadv_iv_ogm_receive(struct sk_buff *skb,
        return NET_RX_SUCCESS;
 }
 
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
 /**
  * batadv_iv_ogm_orig_print_neigh - print neighbors for the originator table
  * @orig_node: the orig_node for which the neighbors are printed
@@ -1976,7 +1953,238 @@ next:
        if (batman_count == 0)
                seq_puts(seq, "No batman nodes in range ...\n");
 }
+#endif
+
+/**
+ * batadv_iv_ogm_neigh_get_tq_avg - Get the TQ average for a neighbour on a
+ *  given outgoing interface.
+ * @neigh_node: Neighbour of interest
+ * @if_outgoing: Outgoing interface of interest
+ * @tq_avg: Pointer of where to store the TQ average
+ *
+ * Return: False if no average TQ available, otherwise true.
+ */
+static bool
+batadv_iv_ogm_neigh_get_tq_avg(struct batadv_neigh_node *neigh_node,
+                              struct batadv_hard_iface *if_outgoing,
+                              u8 *tq_avg)
+{
+       struct batadv_neigh_ifinfo *n_ifinfo;
+
+       n_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
+       if (!n_ifinfo)
+               return false;
+
+       *tq_avg = n_ifinfo->bat_iv.tq_avg;
+       batadv_neigh_ifinfo_put(n_ifinfo);
+
+       return true;
+}
+
+/**
+ * batadv_iv_ogm_orig_dump_subentry - Dump an originator subentry into a
+ *  message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @if_outgoing: Limit dump to entries with this outgoing interface
+ * @orig_node: Originator to dump
+ * @neigh_node: Single hops neighbour
+ * @best: Is the best originator
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_iv_ogm_orig_dump_subentry(struct sk_buff *msg, u32 portid, u32 seq,
+                                struct batadv_priv *bat_priv,
+                                struct batadv_hard_iface *if_outgoing,
+                                struct batadv_orig_node *orig_node,
+                                struct batadv_neigh_node *neigh_node,
+                                bool best)
+{
+       void *hdr;
+       u8 tq_avg;
+       unsigned int last_seen_msecs;
+
+       last_seen_msecs = jiffies_to_msecs(jiffies - orig_node->last_seen);
+
+       if (!batadv_iv_ogm_neigh_get_tq_avg(neigh_node, if_outgoing, &tq_avg))
+               return 0;
+
+       if (if_outgoing != BATADV_IF_DEFAULT &&
+           if_outgoing != neigh_node->if_incoming)
+               return 0;
+
+       hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
+                         NLM_F_MULTI, BATADV_CMD_GET_ORIGINATORS);
+       if (!hdr)
+               return -ENOBUFS;
+
+       if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
+                   orig_node->orig) ||
+           nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
+                   neigh_node->addr) ||
+           nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
+                       neigh_node->if_incoming->net_dev->ifindex) ||
+           nla_put_u8(msg, BATADV_ATTR_TQ, tq_avg) ||
+           nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
+                       last_seen_msecs))
+               goto nla_put_failure;
+
+       if (best && nla_put_flag(msg, BATADV_ATTR_FLAG_BEST))
+               goto nla_put_failure;
+
+       genlmsg_end(msg, hdr);
+       return 0;
+
+ nla_put_failure:
+       genlmsg_cancel(msg, hdr);
+       return -EMSGSIZE;
+}
+
+/**
+ * batadv_iv_ogm_orig_dump_entry - Dump an originator entry into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @if_outgoing: Limit dump to entries with this outgoing interface
+ * @orig_node: Originator to dump
+ * @sub_s: Number of sub entries to skip
+ *
+ * This function assumes the caller holds rcu_read_lock().
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_iv_ogm_orig_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
+                             struct batadv_priv *bat_priv,
+                             struct batadv_hard_iface *if_outgoing,
+                             struct batadv_orig_node *orig_node, int *sub_s)
+{
+       struct batadv_neigh_node *neigh_node_best;
+       struct batadv_neigh_node *neigh_node;
+       int sub = 0;
+       bool best;
+       u8 tq_avg_best;
+
+       neigh_node_best = batadv_orig_router_get(orig_node, if_outgoing);
+       if (!neigh_node_best)
+               goto out;
+
+       if (!batadv_iv_ogm_neigh_get_tq_avg(neigh_node_best, if_outgoing,
+                                           &tq_avg_best))
+               goto out;
+
+       if (tq_avg_best == 0)
+               goto out;
+
+       hlist_for_each_entry_rcu(neigh_node, &orig_node->neigh_list, list) {
+               if (sub++ < *sub_s)
+                       continue;
+
+               best = (neigh_node == neigh_node_best);
+
+               if (batadv_iv_ogm_orig_dump_subentry(msg, portid, seq,
+                                                    bat_priv, if_outgoing,
+                                                    orig_node, neigh_node,
+                                                    best)) {
+                       batadv_neigh_node_put(neigh_node_best);
+
+                       *sub_s = sub - 1;
+                       return -EMSGSIZE;
+               }
+       }
+
+ out:
+       if (neigh_node_best)
+               batadv_neigh_node_put(neigh_node_best);
+
+       *sub_s = 0;
+       return 0;
+}
 
+/**
+ * batadv_iv_ogm_orig_dump_bucket - Dump an originator bucket into a
+ *  message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @if_outgoing: Limit dump to entries with this outgoing interface
+ * @head: Bucket to be dumped
+ * @idx_s: Number of entries to be skipped
+ * @sub: Number of sub entries to be skipped
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_iv_ogm_orig_dump_bucket(struct sk_buff *msg, u32 portid, u32 seq,
+                              struct batadv_priv *bat_priv,
+                              struct batadv_hard_iface *if_outgoing,
+                              struct hlist_head *head, int *idx_s, int *sub)
+{
+       struct batadv_orig_node *orig_node;
+       int idx = 0;
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(orig_node, head, hash_entry) {
+               if (idx++ < *idx_s)
+                       continue;
+
+               if (batadv_iv_ogm_orig_dump_entry(msg, portid, seq, bat_priv,
+                                                 if_outgoing, orig_node,
+                                                 sub)) {
+                       rcu_read_unlock();
+                       *idx_s = idx - 1;
+                       return -EMSGSIZE;
+               }
+       }
+       rcu_read_unlock();
+
+       *idx_s = 0;
+       *sub = 0;
+       return 0;
+}
+
+/**
+ * batadv_iv_ogm_orig_dump - Dump the originators into a message
+ * @msg: Netlink message to dump into
+ * @cb: Control block containing additional options
+ * @bat_priv: The bat priv with all the soft interface information
+ * @if_outgoing: Limit dump to entries with this outgoing interface
+ */
+static void
+batadv_iv_ogm_orig_dump(struct sk_buff *msg, struct netlink_callback *cb,
+                       struct batadv_priv *bat_priv,
+                       struct batadv_hard_iface *if_outgoing)
+{
+       struct batadv_hashtable *hash = bat_priv->orig_hash;
+       struct hlist_head *head;
+       int bucket = cb->args[0];
+       int idx = cb->args[1];
+       int sub = cb->args[2];
+       int portid = NETLINK_CB(cb->skb).portid;
+
+       while (bucket < hash->size) {
+               head = &hash->table[bucket];
+
+               if (batadv_iv_ogm_orig_dump_bucket(msg, portid,
+                                                  cb->nlh->nlmsg_seq,
+                                                  bat_priv, if_outgoing, head,
+                                                  &idx, &sub))
+                       break;
+
+               bucket++;
+       }
+
+       cb->args[0] = bucket;
+       cb->args[1] = idx;
+       cb->args[2] = sub;
+}
+
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
 /**
  * batadv_iv_hardif_neigh_print - print a single hop neighbour node
  * @seq: neighbour table seq_file struct
@@ -2027,37 +2235,43 @@ static void batadv_iv_neigh_print(struct batadv_priv *bat_priv,
        if (batman_count == 0)
                seq_puts(seq, "No batman nodes in range ...\n");
 }
+#endif
 
 /**
- * batadv_iv_ogm_neigh_cmp - compare the metrics of two neighbors
+ * batadv_iv_ogm_neigh_diff - calculate tq difference of two neighbors
  * @neigh1: the first neighbor object of the comparison
  * @if_outgoing1: outgoing interface for the first neighbor
  * @neigh2: the second neighbor object of the comparison
  * @if_outgoing2: outgoing interface for the second neighbor
+ * @diff: pointer to integer receiving the calculated difference
  *
- * Return: a value less, equal to or greater than 0 if the metric via neigh1 is
- * lower, the same as or higher than the metric via neigh2
+ * The content of *@diff is only valid when this function returns true.
+ * It is less, equal to or greater than 0 if the metric via neigh1 is lower,
+ * the same as or higher than the metric via neigh2
+ *
+ * Return: true when the difference could be calculated, false otherwise
  */
-static int batadv_iv_ogm_neigh_cmp(struct batadv_neigh_node *neigh1,
-                                  struct batadv_hard_iface *if_outgoing1,
-                                  struct batadv_neigh_node *neigh2,
-                                  struct batadv_hard_iface *if_outgoing2)
+static bool batadv_iv_ogm_neigh_diff(struct batadv_neigh_node *neigh1,
+                                    struct batadv_hard_iface *if_outgoing1,
+                                    struct batadv_neigh_node *neigh2,
+                                    struct batadv_hard_iface *if_outgoing2,
+                                    int *diff)
 {
        struct batadv_neigh_ifinfo *neigh1_ifinfo, *neigh2_ifinfo;
        u8 tq1, tq2;
-       int diff;
+       bool ret = true;
 
        neigh1_ifinfo = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
        neigh2_ifinfo = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
 
        if (!neigh1_ifinfo || !neigh2_ifinfo) {
-               diff = 0;
+               ret = false;
                goto out;
        }
 
        tq1 = neigh1_ifinfo->bat_iv.tq_avg;
        tq2 = neigh2_ifinfo->bat_iv.tq_avg;
-       diff = tq1 - tq2;
+       *diff = (int)tq1 - (int)tq2;
 
 out:
        if (neigh1_ifinfo)
@@ -2065,6 +2279,162 @@ out:
        if (neigh2_ifinfo)
                batadv_neigh_ifinfo_put(neigh2_ifinfo);
 
+       return ret;
+}
+
+/**
+ * batadv_iv_ogm_neigh_dump_neigh - Dump a neighbour into a netlink message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @hardif_neigh: Neighbour to be dumped
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_iv_ogm_neigh_dump_neigh(struct sk_buff *msg, u32 portid, u32 seq,
+                              struct batadv_hardif_neigh_node *hardif_neigh)
+{
+       void *hdr;
+       unsigned int last_seen_msecs;
+
+       last_seen_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen);
+
+       hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
+                         NLM_F_MULTI, BATADV_CMD_GET_NEIGHBORS);
+       if (!hdr)
+               return -ENOBUFS;
+
+       if (nla_put(msg, BATADV_ATTR_NEIGH_ADDRESS, ETH_ALEN,
+                   hardif_neigh->addr) ||
+           nla_put_u32(msg, BATADV_ATTR_HARD_IFINDEX,
+                       hardif_neigh->if_incoming->net_dev->ifindex) ||
+           nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS,
+                       last_seen_msecs))
+               goto nla_put_failure;
+
+       genlmsg_end(msg, hdr);
+       return 0;
+
+ nla_put_failure:
+       genlmsg_cancel(msg, hdr);
+       return -EMSGSIZE;
+}
+
+/**
+ * batadv_iv_ogm_neigh_dump_hardif - Dump the neighbours of a hard interface
+ *  into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @hard_iface: Hard interface to dump the neighbours for
+ * @idx_s: Number of entries to skip
+ *
+ * This function assumes the caller holds rcu_read_lock().
+ *
+ * Return: Error code, or 0 on success
+ */
+static int
+batadv_iv_ogm_neigh_dump_hardif(struct sk_buff *msg, u32 portid, u32 seq,
+                               struct batadv_priv *bat_priv,
+                               struct batadv_hard_iface *hard_iface,
+                               int *idx_s)
+{
+       struct batadv_hardif_neigh_node *hardif_neigh;
+       int idx = 0;
+
+       hlist_for_each_entry_rcu(hardif_neigh,
+                                &hard_iface->neigh_list, list) {
+               if (idx++ < *idx_s)
+                       continue;
+
+               if (batadv_iv_ogm_neigh_dump_neigh(msg, portid, seq,
+                                                  hardif_neigh)) {
+                       *idx_s = idx - 1;
+                       return -EMSGSIZE;
+               }
+       }
+
+       *idx_s = 0;
+       return 0;
+}
+
+/**
+ * batadv_iv_ogm_neigh_dump - Dump the neighbours into a message
+ * @msg: Netlink message to dump into
+ * @cb: Control block containing additional options
+ * @bat_priv: The bat priv with all the soft interface information
+ * @single_hardif: Limit dump to this hard interfaace
+ */
+static void
+batadv_iv_ogm_neigh_dump(struct sk_buff *msg, struct netlink_callback *cb,
+                        struct batadv_priv *bat_priv,
+                        struct batadv_hard_iface *single_hardif)
+{
+       struct batadv_hard_iface *hard_iface;
+       int i_hardif = 0;
+       int i_hardif_s = cb->args[0];
+       int idx = cb->args[1];
+       int portid = NETLINK_CB(cb->skb).portid;
+
+       rcu_read_lock();
+       if (single_hardif) {
+               if (i_hardif_s == 0) {
+                       if (batadv_iv_ogm_neigh_dump_hardif(msg, portid,
+                                                           cb->nlh->nlmsg_seq,
+                                                           bat_priv,
+                                                           single_hardif,
+                                                           &idx) == 0)
+                               i_hardif++;
+               }
+       } else {
+               list_for_each_entry_rcu(hard_iface, &batadv_hardif_list,
+                                       list) {
+                       if (hard_iface->soft_iface != bat_priv->soft_iface)
+                               continue;
+
+                       if (i_hardif++ < i_hardif_s)
+                               continue;
+
+                       if (batadv_iv_ogm_neigh_dump_hardif(msg, portid,
+                                                           cb->nlh->nlmsg_seq,
+                                                           bat_priv,
+                                                           hard_iface, &idx)) {
+                               i_hardif--;
+                               break;
+                       }
+               }
+       }
+       rcu_read_unlock();
+
+       cb->args[0] = i_hardif;
+       cb->args[1] = idx;
+}
+
+/**
+ * batadv_iv_ogm_neigh_cmp - compare the metrics of two neighbors
+ * @neigh1: the first neighbor object of the comparison
+ * @if_outgoing1: outgoing interface for the first neighbor
+ * @neigh2: the second neighbor object of the comparison
+ * @if_outgoing2: outgoing interface for the second neighbor
+ *
+ * Return: a value less, equal to or greater than 0 if the metric via neigh1 is
+ * lower, the same as or higher than the metric via neigh2
+ */
+static int batadv_iv_ogm_neigh_cmp(struct batadv_neigh_node *neigh1,
+                                  struct batadv_hard_iface *if_outgoing1,
+                                  struct batadv_neigh_node *neigh2,
+                                  struct batadv_hard_iface *if_outgoing2)
+{
+       bool ret;
+       int diff;
+
+       ret = batadv_iv_ogm_neigh_diff(neigh1, if_outgoing1, neigh2,
+                                      if_outgoing2, &diff);
+       if (!ret)
+               return 0;
+
        return diff;
 }
 
@@ -2085,36 +2455,341 @@ batadv_iv_ogm_neigh_is_sob(struct batadv_neigh_node *neigh1,
                           struct batadv_neigh_node *neigh2,
                           struct batadv_hard_iface *if_outgoing2)
 {
-       struct batadv_neigh_ifinfo *neigh1_ifinfo, *neigh2_ifinfo;
-       u8 tq1, tq2;
        bool ret;
+       int diff;
 
-       neigh1_ifinfo = batadv_neigh_ifinfo_get(neigh1, if_outgoing1);
-       neigh2_ifinfo = batadv_neigh_ifinfo_get(neigh2, if_outgoing2);
+       ret = batadv_iv_ogm_neigh_diff(neigh1, if_outgoing1, neigh2,
+                                      if_outgoing2, &diff);
+       if (!ret)
+               return false;
 
-       /* we can't say that the metric is better */
-       if (!neigh1_ifinfo || !neigh2_ifinfo) {
-               ret = false;
+       ret = diff > -BATADV_TQ_SIMILARITY_THRESHOLD;
+       return ret;
+}
+
+static void batadv_iv_iface_activate(struct batadv_hard_iface *hard_iface)
+{
+       /* begin scheduling originator messages on that interface */
+       batadv_iv_ogm_schedule(hard_iface);
+}
+
+static struct batadv_gw_node *
+batadv_iv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
+{
+       struct batadv_neigh_node *router;
+       struct batadv_neigh_ifinfo *router_ifinfo;
+       struct batadv_gw_node *gw_node, *curr_gw = NULL;
+       u64 max_gw_factor = 0;
+       u64 tmp_gw_factor = 0;
+       u8 max_tq = 0;
+       u8 tq_avg;
+       struct batadv_orig_node *orig_node;
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
+               orig_node = gw_node->orig_node;
+               router = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
+               if (!router)
+                       continue;
+
+               router_ifinfo = batadv_neigh_ifinfo_get(router,
+                                                       BATADV_IF_DEFAULT);
+               if (!router_ifinfo)
+                       goto next;
+
+               if (!kref_get_unless_zero(&gw_node->refcount))
+                       goto next;
+
+               tq_avg = router_ifinfo->bat_iv.tq_avg;
+
+               switch (atomic_read(&bat_priv->gw.sel_class)) {
+               case 1: /* fast connection */
+                       tmp_gw_factor = tq_avg * tq_avg;
+                       tmp_gw_factor *= gw_node->bandwidth_down;
+                       tmp_gw_factor *= 100 * 100;
+                       tmp_gw_factor >>= 18;
+
+                       if ((tmp_gw_factor > max_gw_factor) ||
+                           ((tmp_gw_factor == max_gw_factor) &&
+                            (tq_avg > max_tq))) {
+                               if (curr_gw)
+                                       batadv_gw_node_put(curr_gw);
+                               curr_gw = gw_node;
+                               kref_get(&curr_gw->refcount);
+                       }
+                       break;
+
+               default: /* 2:  stable connection (use best statistic)
+                         * 3:  fast-switch (use best statistic but change as
+                         *     soon as a better gateway appears)
+                         * XX: late-switch (use best statistic but change as
+                         *     soon as a better gateway appears which has
+                         *     $routing_class more tq points)
+                         */
+                       if (tq_avg > max_tq) {
+                               if (curr_gw)
+                                       batadv_gw_node_put(curr_gw);
+                               curr_gw = gw_node;
+                               kref_get(&curr_gw->refcount);
+                       }
+                       break;
+               }
+
+               if (tq_avg > max_tq)
+                       max_tq = tq_avg;
+
+               if (tmp_gw_factor > max_gw_factor)
+                       max_gw_factor = tmp_gw_factor;
+
+               batadv_gw_node_put(gw_node);
+
+next:
+               batadv_neigh_node_put(router);
+               if (router_ifinfo)
+                       batadv_neigh_ifinfo_put(router_ifinfo);
+       }
+       rcu_read_unlock();
+
+       return curr_gw;
+}
+
+static bool batadv_iv_gw_is_eligible(struct batadv_priv *bat_priv,
+                                    struct batadv_orig_node *curr_gw_orig,
+                                    struct batadv_orig_node *orig_node)
+{
+       struct batadv_neigh_ifinfo *router_orig_ifinfo = NULL;
+       struct batadv_neigh_ifinfo *router_gw_ifinfo = NULL;
+       struct batadv_neigh_node *router_gw = NULL;
+       struct batadv_neigh_node *router_orig = NULL;
+       u8 gw_tq_avg, orig_tq_avg;
+       bool ret = false;
+
+       /* dynamic re-election is performed only on fast or late switch */
+       if (atomic_read(&bat_priv->gw.sel_class) <= 2)
+               return false;
+
+       router_gw = batadv_orig_router_get(curr_gw_orig, BATADV_IF_DEFAULT);
+       if (!router_gw) {
+               ret = true;
                goto out;
        }
 
-       tq1 = neigh1_ifinfo->bat_iv.tq_avg;
-       tq2 = neigh2_ifinfo->bat_iv.tq_avg;
-       ret = (tq1 - tq2) > -BATADV_TQ_SIMILARITY_THRESHOLD;
+       router_gw_ifinfo = batadv_neigh_ifinfo_get(router_gw,
+                                                  BATADV_IF_DEFAULT);
+       if (!router_gw_ifinfo) {
+               ret = true;
+               goto out;
+       }
+
+       router_orig = batadv_orig_router_get(orig_node, BATADV_IF_DEFAULT);
+       if (!router_orig)
+               goto out;
+
+       router_orig_ifinfo = batadv_neigh_ifinfo_get(router_orig,
+                                                    BATADV_IF_DEFAULT);
+       if (!router_orig_ifinfo)
+               goto out;
+
+       gw_tq_avg = router_gw_ifinfo->bat_iv.tq_avg;
+       orig_tq_avg = router_orig_ifinfo->bat_iv.tq_avg;
+
+       /* the TQ value has to be better */
+       if (orig_tq_avg < gw_tq_avg)
+               goto out;
 
+       /* if the routing class is greater than 3 the value tells us how much
+        * greater the TQ value of the new gateway must be
+        */
+       if ((atomic_read(&bat_priv->gw.sel_class) > 3) &&
+           (orig_tq_avg - gw_tq_avg < atomic_read(&bat_priv->gw.sel_class)))
+               goto out;
+
+       batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+                  "Restarting gateway selection: better gateway found (tq curr: %i, tq new: %i)\n",
+                  gw_tq_avg, orig_tq_avg);
+
+       ret = true;
 out:
-       if (neigh1_ifinfo)
-               batadv_neigh_ifinfo_put(neigh1_ifinfo);
-       if (neigh2_ifinfo)
-               batadv_neigh_ifinfo_put(neigh2_ifinfo);
+       if (router_gw_ifinfo)
+               batadv_neigh_ifinfo_put(router_gw_ifinfo);
+       if (router_orig_ifinfo)
+               batadv_neigh_ifinfo_put(router_orig_ifinfo);
+       if (router_gw)
+               batadv_neigh_node_put(router_gw);
+       if (router_orig)
+               batadv_neigh_node_put(router_orig);
 
        return ret;
 }
 
-static void batadv_iv_iface_activate(struct batadv_hard_iface *hard_iface)
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+/* fails if orig_node has no router */
+static int batadv_iv_gw_write_buffer_text(struct batadv_priv *bat_priv,
+                                         struct seq_file *seq,
+                                         const struct batadv_gw_node *gw_node)
 {
-       /* begin scheduling originator messages on that interface */
-       batadv_iv_ogm_schedule(hard_iface);
+       struct batadv_gw_node *curr_gw;
+       struct batadv_neigh_node *router;
+       struct batadv_neigh_ifinfo *router_ifinfo = NULL;
+       int ret = -1;
+
+       router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
+       if (!router)
+               goto out;
+
+       router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
+       if (!router_ifinfo)
+               goto out;
+
+       curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
+
+       seq_printf(seq, "%s %pM (%3i) %pM [%10s]: %u.%u/%u.%u MBit\n",
+                  (curr_gw == gw_node ? "=>" : "  "),
+                  gw_node->orig_node->orig,
+                  router_ifinfo->bat_iv.tq_avg, router->addr,
+                  router->if_incoming->net_dev->name,
+                  gw_node->bandwidth_down / 10,
+                  gw_node->bandwidth_down % 10,
+                  gw_node->bandwidth_up / 10,
+                  gw_node->bandwidth_up % 10);
+       ret = seq_has_overflowed(seq) ? -1 : 0;
+
+       if (curr_gw)
+               batadv_gw_node_put(curr_gw);
+out:
+       if (router_ifinfo)
+               batadv_neigh_ifinfo_put(router_ifinfo);
+       if (router)
+               batadv_neigh_node_put(router);
+       return ret;
+}
+
+static void batadv_iv_gw_print(struct batadv_priv *bat_priv,
+                              struct seq_file *seq)
+{
+       struct batadv_gw_node *gw_node;
+       int gw_count = 0;
+
+       seq_puts(seq,
+                "      Gateway      (#/255)           Nexthop [outgoingIF]: advertised uplink bandwidth\n");
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
+               /* fails if orig_node has no router */
+               if (batadv_iv_gw_write_buffer_text(bat_priv, seq, gw_node) < 0)
+                       continue;
+
+               gw_count++;
+       }
+       rcu_read_unlock();
+
+       if (gw_count == 0)
+               seq_puts(seq, "No gateways in range ...\n");
+}
+#endif
+
+/**
+ * batadv_iv_gw_dump_entry - Dump a gateway into a message
+ * @msg: Netlink message to dump into
+ * @portid: Port making netlink request
+ * @seq: Sequence number of netlink message
+ * @bat_priv: The bat priv with all the soft interface information
+ * @gw_node: Gateway to be dumped
+ *
+ * Return: Error code, or 0 on success
+ */
+static int batadv_iv_gw_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
+                                  struct batadv_priv *bat_priv,
+                                  struct batadv_gw_node *gw_node)
+{
+       struct batadv_neigh_ifinfo *router_ifinfo = NULL;
+       struct batadv_neigh_node *router;
+       struct batadv_gw_node *curr_gw;
+       int ret = -EINVAL;
+       void *hdr;
+
+       router = batadv_orig_router_get(gw_node->orig_node, BATADV_IF_DEFAULT);
+       if (!router)
+               goto out;
+
+       router_ifinfo = batadv_neigh_ifinfo_get(router, BATADV_IF_DEFAULT);
+       if (!router_ifinfo)
+               goto out;
+
+       curr_gw = batadv_gw_get_selected_gw_node(bat_priv);
+
+       hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
+                         NLM_F_MULTI, BATADV_CMD_GET_GATEWAYS);
+       if (!hdr) {
+               ret = -ENOBUFS;
+               goto out;
+       }
+
+       ret = -EMSGSIZE;
+
+       if (curr_gw == gw_node)
+               if (nla_put_flag(msg, BATADV_ATTR_FLAG_BEST)) {
+                       genlmsg_cancel(msg, hdr);
+                       goto out;
+               }
+
+       if (nla_put(msg, BATADV_ATTR_ORIG_ADDRESS, ETH_ALEN,
+                   gw_node->orig_node->orig) ||
+           nla_put_u8(msg, BATADV_ATTR_TQ, router_ifinfo->bat_iv.tq_avg) ||
+           nla_put(msg, BATADV_ATTR_ROUTER, ETH_ALEN,
+                   router->addr) ||
+           nla_put_string(msg, BATADV_ATTR_HARD_IFNAME,
+                          router->if_incoming->net_dev->name) ||
+           nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_DOWN,
+                       gw_node->bandwidth_down) ||
+           nla_put_u32(msg, BATADV_ATTR_BANDWIDTH_UP,
+                       gw_node->bandwidth_up)) {
+               genlmsg_cancel(msg, hdr);
+               goto out;
+       }
+
+       genlmsg_end(msg, hdr);
+       ret = 0;
+
+out:
+       if (router_ifinfo)
+               batadv_neigh_ifinfo_put(router_ifinfo);
+       if (router)
+               batadv_neigh_node_put(router);
+       return ret;
+}
+
+/**
+ * batadv_iv_gw_dump - Dump gateways into a message
+ * @msg: Netlink message to dump into
+ * @cb: Control block containing additional options
+ * @bat_priv: The bat priv with all the soft interface information
+ */
+static void batadv_iv_gw_dump(struct sk_buff *msg, struct netlink_callback *cb,
+                             struct batadv_priv *bat_priv)
+{
+       int portid = NETLINK_CB(cb->skb).portid;
+       struct batadv_gw_node *gw_node;
+       int idx_skip = cb->args[0];
+       int idx = 0;
+
+       rcu_read_lock();
+       hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
+               if (idx++ < idx_skip)
+                       continue;
+
+               if (batadv_iv_gw_dump_entry(msg, portid, cb->nlh->nlmsg_seq,
+                                           bat_priv, gw_node)) {
+                       idx_skip = idx - 1;
+                       goto unlock;
+               }
+       }
+
+       idx_skip = idx;
+unlock:
+       rcu_read_unlock();
+
+       cb->args[0] = idx_skip;
 }
 
 static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
@@ -2129,14 +2804,28 @@ static struct batadv_algo_ops batadv_batman_iv __read_mostly = {
        .neigh = {
                .cmp = batadv_iv_ogm_neigh_cmp,
                .is_similar_or_better = batadv_iv_ogm_neigh_is_sob,
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
                .print = batadv_iv_neigh_print,
+#endif
+               .dump = batadv_iv_ogm_neigh_dump,
        },
        .orig = {
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
                .print = batadv_iv_ogm_orig_print,
+#endif
+               .dump = batadv_iv_ogm_orig_dump,
                .free = batadv_iv_ogm_orig_free,
                .add_if = batadv_iv_ogm_orig_add_if,
                .del_if = batadv_iv_ogm_orig_del_if,
        },
+       .gw = {
+               .get_best_gw_node = batadv_iv_gw_get_best_gw_node,
+               .is_eligible = batadv_iv_gw_is_eligible,
+#ifdef CONFIG_BATMAN_ADV_DEBUGFS
+               .print = batadv_iv_gw_print,
+#endif
+               .dump = batadv_iv_gw_dump,
+       },
 };
 
 int __init batadv_iv_init(void)