diff options
Diffstat (limited to 'net/batman-adv/bridge_loop_avoidance.c')
| -rw-r--r-- | net/batman-adv/bridge_loop_avoidance.c | 1580 |
1 files changed, 1580 insertions, 0 deletions
diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c new file mode 100644 index 00000000000..8bf97515a77 --- /dev/null +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -0,0 +1,1580 @@ +/* + * Copyright (C) 2011-2012 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 "translation-table.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 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, &bat_priv->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 + * and YY:YY = group id + */ + (uint8_t *)&local_claim_dest); + + if (!skb) + goto out; + + ethhdr = (struct ethhdr *)skb->data; + hw_src = (uint8_t *)ethhdr + ETH_HLEN + 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 + ETH_HLEN; + 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; + struct orig_node *orig_node; + 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; + } + + /* this is a gateway now, remove any tt entries */ + orig_node = orig_hash_find(bat_priv, orig); + if (orig_node) { + tt_global_del_orig(bat_priv, orig_node, + "became a backbone gateway"); + orig_node_free_ref(orig_node); + } + 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 + * @hw_src: the Hardware source in the ARP Header + * @hw_dst: the Hardware destination in the ARP Header + * @ethhdr: pointer to the Ethernet header of the claim frame + * + * checks if it is a claim packet and if its on the same group. + * This function also applies the group ID of the sender + * if it is in the same mesh. + * + * returns: + * 2 - if it is a claim packet and on the same group + * 1 - if is a claim packet from another group + * 0 - if it is not a claim packet + */ +static int check_claim_group(struct bat_priv *bat_priv, + struct hard_iface *primary_if, + uint8_t *hw_src, uint8_t *hw_dst, + struct ethhdr *ethhdr) +{ + uint8_t *backbone_addr; + struct orig_node *orig_node; + struct bla_claim_dst *bla_dst, *bla_dst_own; + + bla_dst = (struct bla_claim_dst *)hw_dst; + bla_dst_own = &bat_priv->claim_dest; + + /* check if it is a claim packet in general */ + if (memcmp(bla_dst->magic, bla_dst_own->magic, + sizeof(bla_dst->magic)) != 0) + return 0; + + /* if announcement packet, use the source, + * otherwise assume it is in the hw_src + */ + switch (bla_dst->type) { + case CLAIM_TYPE_ADD: + backbone_addr = hw_src; + break; + case CLAIM_TYPE_REQUEST: + case CLAIM_TYPE_ANNOUNCE: + case CLAIM_TYPE_DEL: + backbone_addr = ethhdr->h_source; + break; + default: + return 0; + } + + /* don't accept claim frames from ourselves */ + if (compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) + return 0; + + /* if its already the same group, it is fine. */ + if (bla_dst->group == bla_dst_own->group) + return 2; + + /* lets see if this originator is in our mesh */ + orig_node = orig_hash_find(bat_priv, backbone_addr); + + /* dont accept claims from gateways which are not in + * the same mesh or group. + */ + if (!orig_node) + return 1; + + /* if our mesh friends mac is bigger, use it for ourselves. */ + if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) { + bat_dbg(DBG_BLA, bat_priv, + "taking other backbones claim group: %04x\n", + ntohs(bla_dst->group)); + bla_dst_own->group = bla_dst->group; + } + + orig_node_free_ref(orig_node); + + return 2; +} + + +/** + * @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; + int ret; + + 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 = ETH_HLEN; + } + + 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. */ + ret = check_claim_group(bat_priv, primary_if, hw_src, hw_dst, ethhdr); + if (ret == 1) + bat_dbg(DBG_BLA, bat_priv, + "bla_process_claim(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n", + ethhdr->h_source, vid, hw_src, hw_dst); + + if (ret < 2) + return ret; + + /* 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; + + /* reset bridge loop avoidance group id */ + bat_priv->claim_dest.group = + htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN)); + + 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) +{ + int i; + uint8_t claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00}; + struct hard_iface *primary_if; + + bat_dbg(DBG_BLA, bat_priv, "bla hash registering\n"); + + /* setting claim destination address */ + memcpy(&bat_priv->claim_dest.magic, claim_dest, 3); + bat_priv->claim_dest.type = 0; + primary_if = primary_if_get_selected(bat_priv); + if (primary_if) { + bat_priv->claim_dest.group = + htons(crc16(0, primary_if->net_dev->dev_addr, + ETH_ALEN)); + hardif_free_ref(primary_if); + } else { + bat_priv->claim_dest.group = 0; /* will be set later */ + } + + /* initialize the duplicate list */ + for (i = 0; i < DUPLIST_SIZE; i++) + bat_priv->bcast_duplist[i].entrytime = + jiffies - msecs_to_jiffies(DUPLIST_TIMEOUT); + bat_priv->bcast_duplist_curr = 0; + + 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; +} + +/** + * @bat_priv: the bat priv with all the soft interface information + * @bcast_packet: originator mac address + * @hdr_size: maximum length of the frame + * + * check if it is on our broadcast list. Another gateway might + * have sent the same packet because it is connected to the same backbone, + * so we have to remove this duplicate. + * + * This is performed by checking the CRC, which will tell us + * with a good chance that it is the same packet. If it is furthermore + * sent by another host, drop it. We allow equal packets from + * the same host however as this might be intended. + * + **/ + +int bla_check_bcast_duplist(struct bat_priv *bat_priv, + struct bcast_packet *bcast_packet, + int hdr_size) +{ + int i, length, curr; + uint8_t *content; + uint16_t crc; + struct bcast_duplist_entry *entry; + + length = hdr_size - sizeof(*bcast_packet); + content = (uint8_t *)bcast_packet; + content += sizeof(*bcast_packet); + + /* calculate the crc ... */ + crc = crc16(0, content, length); + + for (i = 0 ; i < DUPLIST_SIZE; i++) { + curr = (bat_priv->bcast_duplist_curr + i) % DUPLIST_SIZE; + entry = &bat_priv->bcast_duplist[curr]; + + /* we can stop searching if the entry is too old ; + * later entries will be even older + */ + if (has_timed_out(entry->entrytime, DUPLIST_TIMEOUT)) + break; + + if (entry->crc != crc) + continue; + + if (compare_eth(entry->orig, bcast_packet->orig)) + continue; + + /* this entry seems to match: same crc, not too old, + * and from another gw. therefore return 1 to forbid it. + */ + return 1; + } + /* not found, add a new entry (overwrite the oldest entry) */ + curr = (bat_priv->bcast_duplist_curr + DUPLIST_SIZE - 1) % DUPLIST_SIZE; + entry = &bat_priv->bcast_duplist[curr]; + entry->crc = crc; + entry->entrytime = jiffies; + memcpy(entry->orig, bcast_packet->orig, ETH_ALEN); + bat_priv->bcast_duplist_curr = curr; + + /* allow it, its the first occurence. */ + return 0; +} + + + +/** + * @bat_priv: the bat priv with all the soft interface information + * @orig: originator mac address + * + * check if the originator is a gateway for any VLAN ID. + * + * returns 1 if it is found, 0 otherwise + * + */ + +int bla_is_backbone_gw_orig(struct bat_priv *bat_priv, uint8_t *orig) +{ + struct hashtable_t *hash = bat_priv->backbone_hash; + struct hlist_head *head; + struct hlist_node *node; + struct backbone_gw *backbone_gw; + int i; + + if (!atomic_read(&bat_priv->bridge_loop_avoidance)) + return 0; + + if (!hash) + return 0; + + 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, orig)) { + rcu_read_unlock(); + return 1; + } + } + rcu_read_unlock(); + } + + return 0; +} + + +/** + * @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 + ETH_HLEN)) + 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; +} + +int bla_claim_table_seq_print_text(struct seq_file *seq, void *offset) +{ + struct net_device *net_dev = (struct net_device *)seq->private; + struct bat_priv *bat_priv = netdev_priv(net_dev); + struct hashtable_t *hash = bat_priv->claim_hash; + struct claim *claim; + struct hard_iface *primary_if; + struct hlist_node *node; + struct hlist_head *head; + uint32_t i; + bool is_own; + int ret = 0; + + primary_if = primary_if_get_selected(bat_priv); + if (!primary_if) { + ret = seq_printf(seq, + "BATMAN mesh %s disabled - please specify interfaces to enable it\n", + net_dev->name); + goto out; + } + + if (primary_if->if_status != IF_ACTIVE) { + ret = seq_printf(seq, + "BATMAN mesh %s disabled - primary interface not active\n", + net_dev->name); + goto out; + } + + seq_printf(seq, + "Claims announced for the mesh %s (orig %pM, group id %04x)\n", + net_dev->name, primary_if->net_dev->dev_addr, + ntohs(bat_priv->claim_dest.group)); + seq_printf(seq, " %-17s %-5s %-17s [o] (%-4s)\n", + "Client", "VID", "Originator", "CRC"); + for (i = 0; i < hash->size; i++) { + head = &hash->table[i]; + + rcu_read_lock(); + hlist_for_each_entry_rcu(claim, node, head, hash_entry) { + is_own = compare_eth(claim->backbone_gw->orig, + primary_if->net_dev->dev_addr); + seq_printf(seq, " * %pM on % 5d by %pM [%c] (%04x)\n", + claim->addr, claim->vid, + claim->backbone_gw->orig, + (is_own ? 'x' : ' '), + claim->backbone_gw->crc); + } + rcu_read_unlock(); + } +out: + if (primary_if) + hardif_free_ref(primary_if); + return ret; +} |