--- /dev/null
+/*
+ * Copyright (C) 2011 B.A.T.M.A.N. contributors:
+ *
+ * Simon Wunderlich
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA
+ *
+ */
+
+#include "main.h"
+#include "hash.h"
+#include "hard-interface.h"
+#include "originator.h"
+#include "bridge_loop_avoidance.h"
+#include "send.h"
+
+#include <linux/etherdevice.h>
+#include <linux/crc16.h>
+#include <linux/if_arp.h>
+#include <net/arp.h>
+#include <linux/if_vlan.h>
+
+static const uint8_t claim_dest[6] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00};
+static const uint8_t announce_mac[4] = {0x43, 0x05, 0x43, 0x05};
+
+static void bla_periodic_work(struct work_struct *work);
+static void bla_send_announce(struct bat_priv *bat_priv,
+ struct backbone_gw *backbone_gw);
+
+/* return the index of the claim */
+static inline uint32_t choose_claim(const void *data, uint32_t size)
+{
+ const unsigned char *key = data;
+ uint32_t hash = 0;
+ size_t i;
+
+ for (i = 0; i < ETH_ALEN + sizeof(short); i++) {
+ hash += key[i];
+ hash += (hash << 10);
+ hash ^= (hash >> 6);
+ }
+
+ hash += (hash << 3);
+ hash ^= (hash >> 11);
+ hash += (hash << 15);
+
+ return hash % size;
+}
+
+/* return the index of the backbone gateway */
+static inline uint32_t choose_backbone_gw(const void *data, uint32_t size)
+{
+ const unsigned char *key = data;
+ uint32_t hash = 0;
+ size_t i;
+
+ for (i = 0; i < ETH_ALEN + sizeof(short); i++) {
+ hash += key[i];
+ hash += (hash << 10);
+ hash ^= (hash >> 6);
+ }
+
+ hash += (hash << 3);
+ hash ^= (hash >> 11);
+ hash += (hash << 15);
+
+ return hash % size;
+}
+
+
+/* compares address and vid of two backbone gws */
+static int compare_backbone_gw(const struct hlist_node *node, const void *data2)
+{
+ const void *data1 = container_of(node, struct backbone_gw,
+ hash_entry);
+
+ return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0);
+}
+
+/* compares address and vid of two claims */
+static int compare_claim(const struct hlist_node *node, const void *data2)
+{
+ const void *data1 = container_of(node, struct claim,
+ hash_entry);
+
+ return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0);
+}
+
+/* free a backbone gw */
+static void backbone_gw_free_ref(struct backbone_gw *backbone_gw)
+{
+ if (atomic_dec_and_test(&backbone_gw->refcount))
+ kfree_rcu(backbone_gw, rcu);
+}
+
+/* finally deinitialize the claim */
+static void claim_free_rcu(struct rcu_head *rcu)
+{
+ struct claim *claim;
+
+ claim = container_of(rcu, struct claim, rcu);
+
+ backbone_gw_free_ref(claim->backbone_gw);
+ kfree(claim);
+}
+
+/* free a claim, call claim_free_rcu if its the last reference */
+static void claim_free_ref(struct claim *claim)
+{
+ if (atomic_dec_and_test(&claim->refcount))
+ call_rcu(&claim->rcu, claim_free_rcu);
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @data: search data (may be local/static data)
+ *
+ * looks for a claim in the hash, and returns it if found
+ * or NULL otherwise.
+ */
+static struct claim *claim_hash_find(struct bat_priv *bat_priv,
+ struct claim *data)
+{
+ struct hashtable_t *hash = bat_priv->claim_hash;
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct claim *claim;
+ struct claim *claim_tmp = NULL;
+ int index;
+
+ if (!hash)
+ return NULL;
+
+ index = choose_claim(data, hash->size);
+ head = &hash->table[index];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(claim, node, head, hash_entry) {
+ if (!compare_claim(&claim->hash_entry, data))
+ continue;
+
+ if (!atomic_inc_not_zero(&claim->refcount))
+ continue;
+
+ claim_tmp = claim;
+ break;
+ }
+ rcu_read_unlock();
+
+ return claim_tmp;
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @addr: the address of the originator
+ * @vid: the VLAN ID
+ *
+ * looks for a claim in the hash, and returns it if found
+ * or NULL otherwise.
+ */
+static struct backbone_gw *backbone_hash_find(struct bat_priv *bat_priv,
+ uint8_t *addr, short vid)
+{
+ struct hashtable_t *hash = bat_priv->backbone_hash;
+ struct hlist_head *head;
+ struct hlist_node *node;
+ struct backbone_gw search_entry, *backbone_gw;
+ struct backbone_gw *backbone_gw_tmp = NULL;
+ int index;
+
+ if (!hash)
+ return NULL;
+
+ memcpy(search_entry.orig, addr, ETH_ALEN);
+ search_entry.vid = vid;
+
+ index = choose_backbone_gw(&search_entry, hash->size);
+ head = &hash->table[index];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
+ if (!compare_backbone_gw(&backbone_gw->hash_entry,
+ &search_entry))
+ continue;
+
+ if (!atomic_inc_not_zero(&backbone_gw->refcount))
+ continue;
+
+ backbone_gw_tmp = backbone_gw;
+ break;
+ }
+ rcu_read_unlock();
+
+ return backbone_gw_tmp;
+}
+
+/* delete all claims for a backbone */
+static void bla_del_backbone_claims(struct backbone_gw *backbone_gw)
+{
+ struct hashtable_t *hash;
+ struct hlist_node *node, *node_tmp;
+ struct hlist_head *head;
+ struct claim *claim;
+ int i;
+ spinlock_t *list_lock; /* protects write access to the hash lists */
+
+ hash = backbone_gw->bat_priv->claim_hash;
+ if (!hash)
+ return;
+
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+ list_lock = &hash->list_locks[i];
+
+ spin_lock_bh(list_lock);
+ hlist_for_each_entry_safe(claim, node, node_tmp,
+ head, hash_entry) {
+
+ if (claim->backbone_gw != backbone_gw)
+ continue;
+
+ claim_free_ref(claim);
+ hlist_del_rcu(node);
+ }
+ spin_unlock_bh(list_lock);
+ }
+
+ /* all claims gone, intialize CRC */
+ backbone_gw->crc = BLA_CRC_INIT;
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the mac address to be announced within the claim
+ * @vid: the VLAN ID
+ * @claimtype: the type of the claim (CLAIM, UNCLAIM, ANNOUNCE, ...)
+ *
+ * sends a claim frame according to the provided info.
+ */
+static void bla_send_claim(struct bat_priv *bat_priv, uint8_t *mac,
+ short vid, int claimtype)
+{
+ struct sk_buff *skb;
+ struct ethhdr *ethhdr;
+ struct hard_iface *primary_if;
+ struct net_device *soft_iface;
+ uint8_t *hw_src;
+ struct bla_claim_dst local_claim_dest;
+ uint32_t zeroip = 0;
+
+ primary_if = primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ return;
+
+ memcpy(&local_claim_dest, claim_dest, sizeof(local_claim_dest));
+ local_claim_dest.type = claimtype;
+
+ soft_iface = primary_if->soft_iface;
+
+ skb = arp_create(ARPOP_REPLY, ETH_P_ARP,
+ /* IP DST: 0.0.0.0 */
+ zeroip,
+ primary_if->soft_iface,
+ /* IP SRC: 0.0.0.0 */
+ zeroip,
+ /* Ethernet DST: Broadcast */
+ NULL,
+ /* Ethernet SRC/HW SRC: originator mac */
+ primary_if->net_dev->dev_addr,
+ /* HW DST: FF:43:05:XX:00:00
+ * with XX = claim type
+ */
+ (uint8_t *)&local_claim_dest);
+
+ if (!skb)
+ goto out;
+
+ ethhdr = (struct ethhdr *)skb->data;
+ hw_src = (uint8_t *)ethhdr +
+ sizeof(struct ethhdr) +
+ sizeof(struct arphdr);
+
+ /* now we pretend that the client would have sent this ... */
+ switch (claimtype) {
+ case CLAIM_TYPE_ADD:
+ /* normal claim frame
+ * set Ethernet SRC to the clients mac
+ */
+ memcpy(ethhdr->h_source, mac, ETH_ALEN);
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_send_claim(): CLAIM %pM on vid %d\n", mac, vid);
+ break;
+ case CLAIM_TYPE_DEL:
+ /* unclaim frame
+ * set HW SRC to the clients mac
+ */
+ memcpy(hw_src, mac, ETH_ALEN);
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_send_claim(): UNCLAIM %pM on vid %d\n", mac, vid);
+ break;
+ case CLAIM_TYPE_ANNOUNCE:
+ /* announcement frame
+ * set HW SRC to the special mac containg the crc
+ */
+ memcpy(hw_src, mac, ETH_ALEN);
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_send_claim(): ANNOUNCE of %pM on vid %d\n",
+ ethhdr->h_source, vid);
+ break;
+ case CLAIM_TYPE_REQUEST:
+ /* request frame
+ * set HW SRC to the special mac containg the crc
+ */
+ memcpy(hw_src, mac, ETH_ALEN);
+ memcpy(ethhdr->h_dest, mac, ETH_ALEN);
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_send_claim(): REQUEST of %pM to %pMon vid %d\n",
+ ethhdr->h_source, ethhdr->h_dest, vid);
+ break;
+
+ }
+
+ if (vid != -1)
+ skb = vlan_insert_tag(skb, vid);
+
+ skb_reset_mac_header(skb);
+ skb->protocol = eth_type_trans(skb, soft_iface);
+ bat_priv->stats.rx_packets++;
+ bat_priv->stats.rx_bytes += skb->len + sizeof(struct ethhdr);
+ soft_iface->last_rx = jiffies;
+
+ netif_rx(skb);
+out:
+ if (primary_if)
+ hardif_free_ref(primary_if);
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @orig: the mac address of the originator
+ * @vid: the VLAN ID
+ *
+ * searches for the backbone gw or creates a new one if it could not
+ * be found.
+ */
+static struct backbone_gw *bla_get_backbone_gw(struct bat_priv *bat_priv,
+ uint8_t *orig, short vid)
+{
+ struct backbone_gw *entry;
+ int hash_added;
+
+ entry = backbone_hash_find(bat_priv, orig, vid);
+
+ if (entry)
+ return entry;
+
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_get_backbone_gw(): not found (%pM, %d), creating new entry\n",
+ orig, vid);
+
+ entry = kzalloc(sizeof(*entry), GFP_ATOMIC);
+ if (!entry)
+ return NULL;
+
+ entry->vid = vid;
+ entry->lasttime = jiffies;
+ entry->crc = BLA_CRC_INIT;
+ entry->bat_priv = bat_priv;
+ atomic_set(&entry->request_sent, 0);
+ memcpy(entry->orig, orig, ETH_ALEN);
+
+ /* one for the hash, one for returning */
+ atomic_set(&entry->refcount, 2);
+
+ hash_added = hash_add(bat_priv->backbone_hash, compare_backbone_gw,
+ choose_backbone_gw, entry, &entry->hash_entry);
+
+ if (unlikely(hash_added != 0)) {
+ /* hash failed, free the structure */
+ kfree(entry);
+ return NULL;
+ }
+
+ return entry;
+}
+
+/* update or add the own backbone gw to make sure we announce
+ * where we receive other backbone gws
+ */
+static void bla_update_own_backbone_gw(struct bat_priv *bat_priv,
+ struct hard_iface *primary_if,
+ short vid)
+{
+ struct backbone_gw *backbone_gw;
+
+ backbone_gw = bla_get_backbone_gw(bat_priv,
+ primary_if->net_dev->dev_addr, vid);
+ if (unlikely(!backbone_gw))
+ return;
+
+ backbone_gw->lasttime = jiffies;
+ backbone_gw_free_ref(backbone_gw);
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @vid: the vid where the request came on
+ *
+ * Repeat all of our own claims, and finally send an ANNOUNCE frame
+ * to allow the requester another check if the CRC is correct now.
+ */
+static void bla_answer_request(struct bat_priv *bat_priv,
+ struct hard_iface *primary_if, short vid)
+{
+ struct hlist_node *node;
+ struct hlist_head *head;
+ struct hashtable_t *hash;
+ struct claim *claim;
+ struct backbone_gw *backbone_gw;
+ int i;
+
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_answer_request(): received a claim request, send all of our own claims again\n");
+
+ backbone_gw = backbone_hash_find(bat_priv,
+ primary_if->net_dev->dev_addr, vid);
+ if (!backbone_gw)
+ return;
+
+ hash = bat_priv->claim_hash;
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(claim, node, head, hash_entry) {
+ /* only own claims are interesting */
+ if (claim->backbone_gw != backbone_gw)
+ continue;
+
+ bla_send_claim(bat_priv, claim->addr, claim->vid,
+ CLAIM_TYPE_ADD);
+ }
+ rcu_read_unlock();
+ }
+
+ /* finally, send an announcement frame */
+ bla_send_announce(bat_priv, backbone_gw);
+ backbone_gw_free_ref(backbone_gw);
+}
+
+/**
+ * @backbone_gw: the backbone gateway from whom we are out of sync
+ *
+ * When the crc is wrong, ask the backbone gateway for a full table update.
+ * After the request, it will repeat all of his own claims and finally
+ * send an announcement claim with which we can check again.
+ */
+static void bla_send_request(struct backbone_gw *backbone_gw)
+{
+ /* first, remove all old entries */
+ bla_del_backbone_claims(backbone_gw);
+
+ bat_dbg(DBG_BLA, backbone_gw->bat_priv,
+ "Sending REQUEST to %pM\n",
+ backbone_gw->orig);
+
+ /* send request */
+ bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig,
+ backbone_gw->vid, CLAIM_TYPE_REQUEST);
+
+ /* no local broadcasts should be sent or received, for now. */
+ if (!atomic_read(&backbone_gw->request_sent)) {
+ atomic_inc(&backbone_gw->bat_priv->bla_num_requests);
+ atomic_set(&backbone_gw->request_sent, 1);
+ }
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @backbone_gw: our backbone gateway which should be announced
+ *
+ * This function sends an announcement. It is called from multiple
+ * places.
+ */
+static void bla_send_announce(struct bat_priv *bat_priv,
+ struct backbone_gw *backbone_gw)
+{
+ uint8_t mac[ETH_ALEN];
+ uint16_t crc;
+
+ memcpy(mac, announce_mac, 4);
+ crc = htons(backbone_gw->crc);
+ memcpy(&mac[4], (uint8_t *)&crc, 2);
+
+ bla_send_claim(bat_priv, mac, backbone_gw->vid, CLAIM_TYPE_ANNOUNCE);
+
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @mac: the mac address of the claim
+ * @vid: the VLAN ID of the frame
+ * @backbone_gw: the backbone gateway which claims it
+ *
+ * Adds a claim in the claim hash.
+ */
+static void bla_add_claim(struct bat_priv *bat_priv, const uint8_t *mac,
+ const short vid, struct backbone_gw *backbone_gw)
+{
+ struct claim *claim;
+ struct claim search_claim;
+ int hash_added;
+
+ memcpy(search_claim.addr, mac, ETH_ALEN);
+ search_claim.vid = vid;
+ claim = claim_hash_find(bat_priv, &search_claim);
+
+ /* create a new claim entry if it does not exist yet. */
+ if (!claim) {
+ claim = kzalloc(sizeof(*claim), GFP_ATOMIC);
+ if (!claim)
+ return;
+
+ memcpy(claim->addr, mac, ETH_ALEN);
+ claim->vid = vid;
+ claim->lasttime = jiffies;
+ claim->backbone_gw = backbone_gw;
+
+ atomic_set(&claim->refcount, 2);
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n",
+ mac, vid);
+ hash_added = hash_add(bat_priv->claim_hash, compare_claim,
+ choose_claim, claim, &claim->hash_entry);
+
+ if (unlikely(hash_added != 0)) {
+ /* only local changes happened. */
+ kfree(claim);
+ return;
+ }
+ } else {
+ claim->lasttime = jiffies;
+ if (claim->backbone_gw == backbone_gw)
+ /* no need to register a new backbone */
+ goto claim_free_ref;
+
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_add_claim(): changing ownership for %pM, vid %d\n",
+ mac, vid);
+
+ claim->backbone_gw->crc ^=
+ crc16(0, claim->addr, ETH_ALEN);
+ backbone_gw_free_ref(claim->backbone_gw);
+
+ }
+ /* set (new) backbone gw */
+ atomic_inc(&backbone_gw->refcount);
+ claim->backbone_gw = backbone_gw;
+
+ backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
+ backbone_gw->lasttime = jiffies;
+
+claim_free_ref:
+ claim_free_ref(claim);
+}
+
+/* Delete a claim from the claim hash which has the
+ * given mac address and vid.
+ */
+static void bla_del_claim(struct bat_priv *bat_priv, const uint8_t *mac,
+ const short vid)
+{
+ struct claim search_claim, *claim;
+
+ memcpy(search_claim.addr, mac, ETH_ALEN);
+ search_claim.vid = vid;
+ claim = claim_hash_find(bat_priv, &search_claim);
+ if (!claim)
+ return;
+
+ bat_dbg(DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n", mac, vid);
+
+ hash_remove(bat_priv->claim_hash, compare_claim, choose_claim, claim);
+ claim_free_ref(claim); /* reference from the hash is gone */
+
+ claim->backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN);
+
+ /* don't need the reference from hash_find() anymore */
+ claim_free_ref(claim);
+}
+
+/* check for ANNOUNCE frame, return 1 if handled */
+static int handle_announce(struct bat_priv *bat_priv,
+ uint8_t *an_addr, uint8_t *backbone_addr, short vid)
+{
+ struct backbone_gw *backbone_gw;
+ uint16_t crc;
+
+ if (memcmp(an_addr, announce_mac, 4) != 0)
+ return 0;
+
+ backbone_gw = bla_get_backbone_gw(bat_priv, backbone_addr, vid);
+
+ if (unlikely(!backbone_gw))
+ return 1;
+
+
+ /* handle as ANNOUNCE frame */
+ backbone_gw->lasttime = jiffies;
+ crc = ntohs(*((uint16_t *)(&an_addr[4])));
+
+ bat_dbg(DBG_BLA, bat_priv,
+ "handle_announce(): ANNOUNCE vid %d (sent by %pM)... CRC = %04x\n",
+ vid, backbone_gw->orig, crc);
+
+ if (backbone_gw->crc != crc) {
+ bat_dbg(DBG_BLA, backbone_gw->bat_priv,
+ "handle_announce(): CRC FAILED for %pM/%d (my = %04x, sent = %04x)\n",
+ backbone_gw->orig, backbone_gw->vid, backbone_gw->crc,
+ crc);
+
+ bla_send_request(backbone_gw);
+ } else {
+ /* if we have sent a request and the crc was OK,
+ * we can allow traffic again.
+ */
+ if (atomic_read(&backbone_gw->request_sent)) {
+ atomic_dec(&backbone_gw->bat_priv->bla_num_requests);
+ atomic_set(&backbone_gw->request_sent, 0);
+ }
+ }
+
+ backbone_gw_free_ref(backbone_gw);
+ return 1;
+}
+
+/* check for REQUEST frame, return 1 if handled */
+static int handle_request(struct bat_priv *bat_priv,
+ struct hard_iface *primary_if,
+ uint8_t *backbone_addr,
+ struct ethhdr *ethhdr, short vid)
+{
+ /* check for REQUEST frame */
+ if (!compare_eth(backbone_addr, ethhdr->h_dest))
+ return 0;
+
+ /* sanity check, this should not happen on a normal switch,
+ * we ignore it in this case.
+ */
+ if (!compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr))
+ return 1;
+
+ bat_dbg(DBG_BLA, bat_priv,
+ "handle_request(): REQUEST vid %d (sent by %pM)...\n",
+ vid, ethhdr->h_source);
+
+ bla_answer_request(bat_priv, primary_if, vid);
+ return 1;
+}
+
+/* check for UNCLAIM frame, return 1 if handled */
+static int handle_unclaim(struct bat_priv *bat_priv,
+ struct hard_iface *primary_if,
+ uint8_t *backbone_addr,
+ uint8_t *claim_addr, short vid)
+{
+ struct backbone_gw *backbone_gw;
+
+ /* unclaim in any case if it is our own */
+ if (primary_if && compare_eth(backbone_addr,
+ primary_if->net_dev->dev_addr))
+ bla_send_claim(bat_priv, claim_addr, vid, CLAIM_TYPE_DEL);
+
+ backbone_gw = backbone_hash_find(bat_priv, backbone_addr, vid);
+
+ if (!backbone_gw)
+ return 1;
+
+ /* this must be an UNCLAIM frame */
+ bat_dbg(DBG_BLA, bat_priv,
+ "handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n",
+ claim_addr, vid, backbone_gw->orig);
+
+ bla_del_claim(bat_priv, claim_addr, vid);
+ backbone_gw_free_ref(backbone_gw);
+ return 1;
+}
+
+/* check for CLAIM frame, return 1 if handled */
+static int handle_claim(struct bat_priv *bat_priv,
+ struct hard_iface *primary_if, uint8_t *backbone_addr,
+ uint8_t *claim_addr, short vid)
+{
+ struct backbone_gw *backbone_gw;
+
+ /* register the gateway if not yet available, and add the claim. */
+
+ backbone_gw = bla_get_backbone_gw(bat_priv, backbone_addr, vid);
+
+ if (unlikely(!backbone_gw))
+ return 1;
+
+ /* this must be a CLAIM frame */
+ bla_add_claim(bat_priv, claim_addr, vid, backbone_gw);
+ if (compare_eth(backbone_addr, primary_if->net_dev->dev_addr))
+ bla_send_claim(bat_priv, claim_addr, vid, CLAIM_TYPE_ADD);
+
+ /* TODO: we could call something like tt_local_del() here. */
+
+ backbone_gw_free_ref(backbone_gw);
+ return 1;
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the frame to be checked
+ *
+ * Check if this is a claim frame, and process it accordingly.
+ *
+ * returns 1 if it was a claim frame, otherwise return 0 to
+ * tell the callee that it can use the frame on its own.
+ */
+static int bla_process_claim(struct bat_priv *bat_priv,
+ struct hard_iface *primary_if,
+ struct sk_buff *skb)
+{
+ struct ethhdr *ethhdr;
+ struct vlan_ethhdr *vhdr;
+ struct arphdr *arphdr;
+ uint8_t *hw_src, *hw_dst;
+ struct bla_claim_dst *bla_dst;
+ uint16_t proto;
+ int headlen;
+ short vid = -1;
+
+ ethhdr = (struct ethhdr *)skb_mac_header(skb);
+
+ if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
+ vhdr = (struct vlan_ethhdr *)ethhdr;
+ vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
+ proto = ntohs(vhdr->h_vlan_encapsulated_proto);
+ headlen = sizeof(*vhdr);
+ } else {
+ proto = ntohs(ethhdr->h_proto);
+ headlen = sizeof(*ethhdr);
+ }
+
+ if (proto != ETH_P_ARP)
+ return 0; /* not a claim frame */
+
+ /* this must be a ARP frame. check if it is a claim. */
+
+ if (unlikely(!pskb_may_pull(skb, headlen + arp_hdr_len(skb->dev))))
+ return 0;
+
+ /* pskb_may_pull() may have modified the pointers, get ethhdr again */
+ ethhdr = (struct ethhdr *)skb_mac_header(skb);
+ arphdr = (struct arphdr *)((uint8_t *)ethhdr + headlen);
+
+ /* Check whether the ARP frame carries a valid
+ * IP information
+ */
+
+ if (arphdr->ar_hrd != htons(ARPHRD_ETHER))
+ return 0;
+ if (arphdr->ar_pro != htons(ETH_P_IP))
+ return 0;
+ if (arphdr->ar_hln != ETH_ALEN)
+ return 0;
+ if (arphdr->ar_pln != 4)
+ return 0;
+
+ hw_src = (uint8_t *)arphdr + sizeof(struct arphdr);
+ hw_dst = hw_src + ETH_ALEN + 4;
+ bla_dst = (struct bla_claim_dst *)hw_dst;
+
+ /* check if it is a claim frame. */
+ if (memcmp(hw_dst, claim_dest, 3) != 0)
+ return 0;
+
+ /* become a backbone gw ourselves on this vlan if not happened yet */
+ bla_update_own_backbone_gw(bat_priv, primary_if, vid);
+
+ /* check for the different types of claim frames ... */
+ switch (bla_dst->type) {
+ case CLAIM_TYPE_ADD:
+ if (handle_claim(bat_priv, primary_if, hw_src,
+ ethhdr->h_source, vid))
+ return 1;
+ break;
+ case CLAIM_TYPE_DEL:
+ if (handle_unclaim(bat_priv, primary_if,
+ ethhdr->h_source, hw_src, vid))
+ return 1;
+ break;
+
+ case CLAIM_TYPE_ANNOUNCE:
+ if (handle_announce(bat_priv, hw_src, ethhdr->h_source, vid))
+ return 1;
+ break;
+ case CLAIM_TYPE_REQUEST:
+ if (handle_request(bat_priv, primary_if, hw_src, ethhdr, vid))
+ return 1;
+ break;
+ }
+
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_process_claim(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n",
+ ethhdr->h_source, vid, hw_src, hw_dst);
+ return 1;
+}
+
+/* Check when we last heard from other nodes, and remove them in case of
+ * a time out, or clean all backbone gws if now is set.
+ */
+static void bla_purge_backbone_gw(struct bat_priv *bat_priv, int now)
+{
+ struct backbone_gw *backbone_gw;
+ struct hlist_node *node, *node_tmp;
+ struct hlist_head *head;
+ struct hashtable_t *hash;
+ spinlock_t *list_lock; /* protects write access to the hash lists */
+ int i;
+
+ hash = bat_priv->backbone_hash;
+ if (!hash)
+ return;
+
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+ list_lock = &hash->list_locks[i];
+
+ spin_lock_bh(list_lock);
+ hlist_for_each_entry_safe(backbone_gw, node, node_tmp,
+ head, hash_entry) {
+ if (now)
+ goto purge_now;
+ if (!has_timed_out(backbone_gw->lasttime,
+ BLA_BACKBONE_TIMEOUT))
+ continue;
+
+ bat_dbg(DBG_BLA, backbone_gw->bat_priv,
+ "bla_purge_backbone_gw(): backbone gw %pM timed out\n",
+ backbone_gw->orig);
+
+purge_now:
+ /* don't wait for the pending request anymore */
+ if (atomic_read(&backbone_gw->request_sent))
+ atomic_dec(&bat_priv->bla_num_requests);
+
+ bla_del_backbone_claims(backbone_gw);
+
+ hlist_del_rcu(node);
+ backbone_gw_free_ref(backbone_gw);
+ }
+ spin_unlock_bh(list_lock);
+ }
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @primary_if: the selected primary interface, may be NULL if now is set
+ * @now: whether the whole hash shall be wiped now
+ *
+ * Check when we heard last time from our own claims, and remove them in case of
+ * a time out, or clean all claims if now is set
+ */
+static void bla_purge_claims(struct bat_priv *bat_priv,
+ struct hard_iface *primary_if, int now)
+{
+ struct claim *claim;
+ struct hlist_node *node;
+ struct hlist_head *head;
+ struct hashtable_t *hash;
+ int i;
+
+ hash = bat_priv->claim_hash;
+ if (!hash)
+ return;
+
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(claim, node, head, hash_entry) {
+ if (now)
+ goto purge_now;
+ if (!compare_eth(claim->backbone_gw->orig,
+ primary_if->net_dev->dev_addr))
+ continue;
+ if (!has_timed_out(claim->lasttime,
+ BLA_CLAIM_TIMEOUT))
+ continue;
+
+ bat_dbg(DBG_BLA, bat_priv,
+ "bla_purge_claims(): %pM, vid %d, time out\n",
+ claim->addr, claim->vid);
+
+purge_now:
+ handle_unclaim(bat_priv, primary_if,
+ claim->backbone_gw->orig,
+ claim->addr, claim->vid);
+ }
+ rcu_read_unlock();
+ }
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @primary_if: the new selected primary_if
+ * @oldif: the old primary interface, may be NULL
+ *
+ * Update the backbone gateways when the own orig address changes.
+ *
+ */
+void bla_update_orig_address(struct bat_priv *bat_priv,
+ struct hard_iface *primary_if,
+ struct hard_iface *oldif)
+{
+ struct backbone_gw *backbone_gw;
+ struct hlist_node *node;
+ struct hlist_head *head;
+ struct hashtable_t *hash;
+ int i;
+
+ if (!oldif) {
+ bla_purge_claims(bat_priv, NULL, 1);
+ bla_purge_backbone_gw(bat_priv, 1);
+ return;
+ }
+
+ hash = bat_priv->backbone_hash;
+ if (!hash)
+ return;
+
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
+ /* own orig still holds the old value. */
+ if (!compare_eth(backbone_gw->orig,
+ oldif->net_dev->dev_addr))
+ continue;
+
+ memcpy(backbone_gw->orig,
+ primary_if->net_dev->dev_addr, ETH_ALEN);
+ /* send an announce frame so others will ask for our
+ * claims and update their tables.
+ */
+ bla_send_announce(bat_priv, backbone_gw);
+ }
+ rcu_read_unlock();
+ }
+}
+
+
+
+/* (re)start the timer */
+static void bla_start_timer(struct bat_priv *bat_priv)
+{
+ INIT_DELAYED_WORK(&bat_priv->bla_work, bla_periodic_work);
+ queue_delayed_work(bat_event_workqueue, &bat_priv->bla_work,
+ msecs_to_jiffies(BLA_PERIOD_LENGTH));
+}
+
+/* periodic work to do:
+ * * purge structures when they are too old
+ * * send announcements
+ */
+static void bla_periodic_work(struct work_struct *work)
+{
+ struct delayed_work *delayed_work =
+ container_of(work, struct delayed_work, work);
+ struct bat_priv *bat_priv =
+ container_of(delayed_work, struct bat_priv, bla_work);
+ struct hlist_node *node;
+ struct hlist_head *head;
+ struct backbone_gw *backbone_gw;
+ struct hashtable_t *hash;
+ struct hard_iface *primary_if;
+ int i;
+
+ primary_if = primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto out;
+
+ bla_purge_claims(bat_priv, primary_if, 0);
+ bla_purge_backbone_gw(bat_priv, 0);
+
+ if (!atomic_read(&bat_priv->bridge_loop_avoidance))
+ goto out;
+
+ hash = bat_priv->backbone_hash;
+ if (!hash)
+ goto out;
+
+ for (i = 0; i < hash->size; i++) {
+ head = &hash->table[i];
+
+ rcu_read_lock();
+ hlist_for_each_entry_rcu(backbone_gw, node, head, hash_entry) {
+ if (!compare_eth(backbone_gw->orig,
+ primary_if->net_dev->dev_addr))
+ continue;
+
+ backbone_gw->lasttime = jiffies;
+
+ bla_send_announce(bat_priv, backbone_gw);
+ }
+ rcu_read_unlock();
+ }
+out:
+ if (primary_if)
+ hardif_free_ref(primary_if);
+
+ bla_start_timer(bat_priv);
+}
+
+/* initialize all bla structures */
+int bla_init(struct bat_priv *bat_priv)
+{
+ bat_dbg(DBG_BLA, bat_priv, "bla hash registering\n");
+
+ if (bat_priv->claim_hash)
+ return 1;
+
+ bat_priv->claim_hash = hash_new(128);
+ bat_priv->backbone_hash = hash_new(32);
+
+ if (!bat_priv->claim_hash || !bat_priv->backbone_hash)
+ return -1;
+
+ bat_dbg(DBG_BLA, bat_priv, "bla hashes initialized\n");
+
+ bla_start_timer(bat_priv);
+ return 1;
+}
+
+/**
+ * @skb: the frame to be checked
+ * @orig_node: the orig_node of the frame
+ * @hdr_size: maximum length of the frame
+ *
+ * bla_is_backbone_gw inspects the skb for the VLAN ID and returns 1
+ * if the orig_node is also a gateway on the soft interface, otherwise it
+ * returns 0.
+ *
+ */
+int bla_is_backbone_gw(struct sk_buff *skb,
+ struct orig_node *orig_node, int hdr_size)
+{
+ struct ethhdr *ethhdr;
+ struct vlan_ethhdr *vhdr;
+ struct backbone_gw *backbone_gw;
+ short vid = -1;
+
+ if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance))
+ return 0;
+
+ /* first, find out the vid. */
+ if (!pskb_may_pull(skb, hdr_size + sizeof(struct ethhdr)))
+ return 0;
+
+ ethhdr = (struct ethhdr *)(((uint8_t *)skb->data) + hdr_size);
+
+ if (ntohs(ethhdr->h_proto) == ETH_P_8021Q) {
+ if (!pskb_may_pull(skb, hdr_size + sizeof(struct vlan_ethhdr)))
+ return 0;
+
+ vhdr = (struct vlan_ethhdr *)(((uint8_t *)skb->data) +
+ hdr_size);
+ vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK;
+ }
+
+ /* see if this originator is a backbone gw for this VLAN */
+
+ backbone_gw = backbone_hash_find(orig_node->bat_priv,
+ orig_node->orig, vid);
+ if (!backbone_gw)
+ return 0;
+
+ backbone_gw_free_ref(backbone_gw);
+ return 1;
+}
+
+/* free all bla structures (for softinterface free or module unload) */
+void bla_free(struct bat_priv *bat_priv)
+{
+ struct hard_iface *primary_if;
+
+ cancel_delayed_work_sync(&bat_priv->bla_work);
+ primary_if = primary_if_get_selected(bat_priv);
+
+ if (bat_priv->claim_hash) {
+ bla_purge_claims(bat_priv, primary_if, 1);
+ hash_destroy(bat_priv->claim_hash);
+ bat_priv->claim_hash = NULL;
+ }
+ if (bat_priv->backbone_hash) {
+ bla_purge_backbone_gw(bat_priv, 1);
+ hash_destroy(bat_priv->backbone_hash);
+ bat_priv->backbone_hash = NULL;
+ }
+ if (primary_if)
+ hardif_free_ref(primary_if);
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the frame to be checked
+ * @vid: the VLAN ID of the frame
+ *
+ * bla_rx avoidance checks if:
+ * * we have to race for a claim
+ * * if the frame is allowed on the LAN
+ *
+ * in these cases, the skb is further handled by this function and
+ * returns 1, otherwise it returns 0 and the caller shall further
+ * process the skb.
+ *
+ */
+int bla_rx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid)
+{
+ struct ethhdr *ethhdr;
+ struct claim search_claim, *claim = NULL;
+ struct hard_iface *primary_if;
+ int ret;
+
+ ethhdr = (struct ethhdr *)skb_mac_header(skb);
+
+ primary_if = primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto handled;
+
+ if (!atomic_read(&bat_priv->bridge_loop_avoidance))
+ goto allow;
+
+
+ if (unlikely(atomic_read(&bat_priv->bla_num_requests)))
+ /* don't allow broadcasts while requests are in flight */
+ if (is_multicast_ether_addr(ethhdr->h_dest))
+ goto handled;
+
+ memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
+ search_claim.vid = vid;
+ claim = claim_hash_find(bat_priv, &search_claim);
+
+ if (!claim) {
+ /* possible optimization: race for a claim */
+ /* No claim exists yet, claim it for us!
+ */
+ handle_claim(bat_priv, primary_if,
+ primary_if->net_dev->dev_addr,
+ ethhdr->h_source, vid);
+ goto allow;
+ }
+
+ /* if it is our own claim ... */
+ if (compare_eth(claim->backbone_gw->orig,
+ primary_if->net_dev->dev_addr)) {
+ /* ... allow it in any case */
+ claim->lasttime = jiffies;
+ goto allow;
+ }
+
+ /* if it is a broadcast ... */
+ if (is_multicast_ether_addr(ethhdr->h_dest)) {
+ /* ... drop it. the responsible gateway is in charge. */
+ goto handled;
+ } else {
+ /* seems the client considers us as its best gateway.
+ * send a claim and update the claim table
+ * immediately.
+ */
+ handle_claim(bat_priv, primary_if,
+ primary_if->net_dev->dev_addr,
+ ethhdr->h_source, vid);
+ goto allow;
+ }
+allow:
+ bla_update_own_backbone_gw(bat_priv, primary_if, vid);
+ ret = 0;
+ goto out;
+
+handled:
+ kfree_skb(skb);
+ ret = 1;
+
+out:
+ if (primary_if)
+ hardif_free_ref(primary_if);
+ if (claim)
+ claim_free_ref(claim);
+ return ret;
+}
+
+/**
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the frame to be checked
+ * @vid: the VLAN ID of the frame
+ *
+ * bla_tx checks if:
+ * * a claim was received which has to be processed
+ * * the frame is allowed on the mesh
+ *
+ * in these cases, the skb is further handled by this function and
+ * returns 1, otherwise it returns 0 and the caller shall further
+ * process the skb.
+ *
+ */
+int bla_tx(struct bat_priv *bat_priv, struct sk_buff *skb, short vid)
+{
+ struct ethhdr *ethhdr;
+ struct claim search_claim, *claim = NULL;
+ struct hard_iface *primary_if;
+ int ret = 0;
+
+ primary_if = primary_if_get_selected(bat_priv);
+ if (!primary_if)
+ goto out;
+
+ if (!atomic_read(&bat_priv->bridge_loop_avoidance))
+ goto allow;
+
+ /* in VLAN case, the mac header might not be set. */
+ skb_reset_mac_header(skb);
+
+ if (bla_process_claim(bat_priv, primary_if, skb))
+ goto handled;
+
+ ethhdr = (struct ethhdr *)skb_mac_header(skb);
+
+ if (unlikely(atomic_read(&bat_priv->bla_num_requests)))
+ /* don't allow broadcasts while requests are in flight */
+ if (is_multicast_ether_addr(ethhdr->h_dest))
+ goto handled;
+
+ memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN);
+ search_claim.vid = vid;
+
+ claim = claim_hash_find(bat_priv, &search_claim);
+
+ /* if no claim exists, allow it. */
+ if (!claim)
+ goto allow;
+
+ /* check if we are responsible. */
+ if (compare_eth(claim->backbone_gw->orig,
+ primary_if->net_dev->dev_addr)) {
+ /* if yes, the client has roamed and we have
+ * to unclaim it.
+ */
+ handle_unclaim(bat_priv, primary_if,
+ primary_if->net_dev->dev_addr,
+ ethhdr->h_source, vid);
+ goto allow;
+ }
+
+ /* check if it is a multicast/broadcast frame */
+ if (is_multicast_ether_addr(ethhdr->h_dest)) {
+ /* drop it. the responsible gateway has forwarded it into
+ * the backbone network.
+ */
+ goto handled;
+ } else {
+ /* we must allow it. at least if we are
+ * responsible for the DESTINATION.
+ */
+ goto allow;
+ }
+allow:
+ bla_update_own_backbone_gw(bat_priv, primary_if, vid);
+ ret = 0;
+ goto out;
+handled:
+ ret = 1;
+out:
+ if (primary_if)
+ hardif_free_ref(primary_if);
+ if (claim)
+ claim_free_ref(claim);
+ return ret;
+}
projects / platform / kernel / linux-exynos.git / commitdiff