/* 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 #include #include #include #include static const uint8_t batadv_announce_mac[4] = {0x43, 0x05, 0x43, 0x05}; static void batadv_bla_periodic_work(struct work_struct *work); static void batadv_bla_send_announce(struct batadv_priv *bat_priv, struct batadv_backbone_gw *backbone_gw); /* return the index of the claim */ static inline uint32_t batadv_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 batadv_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 batadv_compare_backbone_gw(const struct hlist_node *node, const void *data2) { const void *data1 = container_of(node, struct batadv_backbone_gw, hash_entry); return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0); } /* compares address and vid of two claims */ static int batadv_compare_claim(const struct hlist_node *node, const void *data2) { const void *data1 = container_of(node, struct batadv_claim, hash_entry); return (memcmp(data1, data2, ETH_ALEN + sizeof(short)) == 0 ? 1 : 0); } /* free a backbone gw */ static void batadv_backbone_gw_free_ref(struct batadv_backbone_gw *backbone_gw) { if (atomic_dec_and_test(&backbone_gw->refcount)) kfree_rcu(backbone_gw, rcu); } /* finally deinitialize the claim */ static void batadv_claim_free_rcu(struct rcu_head *rcu) { struct batadv_claim *claim; claim = container_of(rcu, struct batadv_claim, rcu); batadv_backbone_gw_free_ref(claim->backbone_gw); kfree(claim); } /* free a claim, call claim_free_rcu if its the last reference */ static void batadv_claim_free_ref(struct batadv_claim *claim) { if (atomic_dec_and_test(&claim->refcount)) call_rcu(&claim->rcu, batadv_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 batadv_claim *batadv_claim_hash_find(struct batadv_priv *bat_priv, struct batadv_claim *data) { struct batadv_hashtable *hash = bat_priv->claim_hash; struct hlist_head *head; struct hlist_node *node; struct batadv_claim *claim; struct batadv_claim *claim_tmp = NULL; int index; if (!hash) return NULL; index = batadv_choose_claim(data, hash->size); head = &hash->table[index]; rcu_read_lock(); hlist_for_each_entry_rcu(claim, node, head, hash_entry) { if (!batadv_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; } /** * batadv_backbone_hash_find - looks for a claim in the hash * @bat_priv: the bat priv with all the soft interface information * @addr: the address of the originator * @vid: the VLAN ID * * Returns claim if found or NULL otherwise. */ static struct batadv_backbone_gw * batadv_backbone_hash_find(struct batadv_priv *bat_priv, uint8_t *addr, short vid) { struct batadv_hashtable *hash = bat_priv->backbone_hash; struct hlist_head *head; struct hlist_node *node; struct batadv_backbone_gw search_entry, *backbone_gw; struct batadv_backbone_gw *backbone_gw_tmp = NULL; int index; if (!hash) return NULL; memcpy(search_entry.orig, addr, ETH_ALEN); search_entry.vid = vid; index = batadv_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 (!batadv_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 batadv_bla_del_backbone_claims(struct batadv_backbone_gw *backbone_gw) { struct batadv_hashtable *hash; struct hlist_node *node, *node_tmp; struct hlist_head *head; struct batadv_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; batadv_claim_free_ref(claim); hlist_del_rcu(node); } spin_unlock_bh(list_lock); } /* all claims gone, intialize CRC */ backbone_gw->crc = BATADV_BLA_CRC_INIT; } /** * batadv_bla_send_claim - sends a claim frame according to the provided info * @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, ...) */ static void batadv_bla_send_claim(struct batadv_priv *bat_priv, uint8_t *mac, short vid, int claimtype) { struct sk_buff *skb; struct ethhdr *ethhdr; struct batadv_hard_iface *primary_if; struct net_device *soft_iface; uint8_t *hw_src; struct batadv_bla_claim_dst local_claim_dest; __be32 zeroip = 0; primary_if = batadv_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 BATADV_CLAIM_TYPE_ADD: /* normal claim frame * set Ethernet SRC to the clients mac */ memcpy(ethhdr->h_source, mac, ETH_ALEN); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_send_claim(): CLAIM %pM on vid %d\n", mac, vid); break; case BATADV_CLAIM_TYPE_DEL: /* unclaim frame * set HW SRC to the clients mac */ memcpy(hw_src, mac, ETH_ALEN); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_send_claim(): UNCLAIM %pM on vid %d\n", mac, vid); break; case BATADV_CLAIM_TYPE_ANNOUNCE: /* announcement frame * set HW SRC to the special mac containg the crc */ memcpy(hw_src, mac, ETH_ALEN); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_send_claim(): ANNOUNCE of %pM on vid %d\n", ethhdr->h_source, vid); break; case BATADV_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); batadv_dbg(BATADV_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) batadv_hardif_free_ref(primary_if); } /** * batadv_bla_get_backbone_gw * @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 batadv_backbone_gw * batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, uint8_t *orig, short vid) { struct batadv_backbone_gw *entry; struct batadv_orig_node *orig_node; int hash_added; entry = batadv_backbone_hash_find(bat_priv, orig, vid); if (entry) return entry; batadv_dbg(BATADV_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 = BATADV_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 = batadv_hash_add(bat_priv->backbone_hash, batadv_compare_backbone_gw, batadv_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 = batadv_orig_hash_find(bat_priv, orig); if (orig_node) { batadv_tt_global_del_orig(bat_priv, orig_node, "became a backbone gateway"); batadv_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 batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, short vid) { struct batadv_backbone_gw *backbone_gw; backbone_gw = batadv_bla_get_backbone_gw(bat_priv, primary_if->net_dev->dev_addr, vid); if (unlikely(!backbone_gw)) return; backbone_gw->lasttime = jiffies; batadv_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 batadv_bla_answer_request(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, short vid) { struct hlist_node *node; struct hlist_head *head; struct batadv_hashtable *hash; struct batadv_claim *claim; struct batadv_backbone_gw *backbone_gw; int i; batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_answer_request(): received a claim request, send all of our own claims again\n"); backbone_gw = batadv_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; batadv_bla_send_claim(bat_priv, claim->addr, claim->vid, BATADV_CLAIM_TYPE_ADD); } rcu_read_unlock(); } /* finally, send an announcement frame */ batadv_bla_send_announce(bat_priv, backbone_gw); batadv_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 batadv_bla_send_request(struct batadv_backbone_gw *backbone_gw) { /* first, remove all old entries */ batadv_bla_del_backbone_claims(backbone_gw); batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, "Sending REQUEST to %pM\n", backbone_gw->orig); /* send request */ batadv_bla_send_claim(backbone_gw->bat_priv, backbone_gw->orig, backbone_gw->vid, BATADV_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 batadv_bla_send_announce(struct batadv_priv *bat_priv, struct batadv_backbone_gw *backbone_gw) { uint8_t mac[ETH_ALEN]; __be16 crc; memcpy(mac, batadv_announce_mac, 4); crc = htons(backbone_gw->crc); memcpy(&mac[4], &crc, 2); batadv_bla_send_claim(bat_priv, mac, backbone_gw->vid, BATADV_CLAIM_TYPE_ANNOUNCE); } /** * batadv_bla_add_claim - Adds a claim in the claim hash * @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 */ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, const uint8_t *mac, const short vid, struct batadv_backbone_gw *backbone_gw) { struct batadv_claim *claim; struct batadv_claim search_claim; int hash_added; memcpy(search_claim.addr, mac, ETH_ALEN); search_claim.vid = vid; claim = batadv_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); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_add_claim(): adding new entry %pM, vid %d to hash ...\n", mac, vid); hash_added = batadv_hash_add(bat_priv->claim_hash, batadv_compare_claim, batadv_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; batadv_dbg(BATADV_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); batadv_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: batadv_claim_free_ref(claim); } /* Delete a claim from the claim hash which has the * given mac address and vid. */ static void batadv_bla_del_claim(struct batadv_priv *bat_priv, const uint8_t *mac, const short vid) { struct batadv_claim search_claim, *claim; memcpy(search_claim.addr, mac, ETH_ALEN); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim); if (!claim) return; batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_del_claim(): %pM, vid %d\n", mac, vid); batadv_hash_remove(bat_priv->claim_hash, batadv_compare_claim, batadv_choose_claim, claim); batadv_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 */ batadv_claim_free_ref(claim); } /* check for ANNOUNCE frame, return 1 if handled */ static int batadv_handle_announce(struct batadv_priv *bat_priv, uint8_t *an_addr, uint8_t *backbone_addr, short vid) { struct batadv_backbone_gw *backbone_gw; uint16_t crc; if (memcmp(an_addr, batadv_announce_mac, 4) != 0) return 0; backbone_gw = batadv_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(*((__be16 *)(&an_addr[4]))); batadv_dbg(BATADV_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) { batadv_dbg(BATADV_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); batadv_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); } } batadv_backbone_gw_free_ref(backbone_gw); return 1; } /* check for REQUEST frame, return 1 if handled */ static int batadv_handle_request(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, uint8_t *backbone_addr, struct ethhdr *ethhdr, short vid) { /* check for REQUEST frame */ if (!batadv_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 (!batadv_compare_eth(ethhdr->h_dest, primary_if->net_dev->dev_addr)) return 1; batadv_dbg(BATADV_DBG_BLA, bat_priv, "handle_request(): REQUEST vid %d (sent by %pM)...\n", vid, ethhdr->h_source); batadv_bla_answer_request(bat_priv, primary_if, vid); return 1; } /* check for UNCLAIM frame, return 1 if handled */ static int batadv_handle_unclaim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, uint8_t *backbone_addr, uint8_t *claim_addr, short vid) { struct batadv_backbone_gw *backbone_gw; /* unclaim in any case if it is our own */ if (primary_if && batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) batadv_bla_send_claim(bat_priv, claim_addr, vid, BATADV_CLAIM_TYPE_DEL); backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid); if (!backbone_gw) return 1; /* this must be an UNCLAIM frame */ batadv_dbg(BATADV_DBG_BLA, bat_priv, "handle_unclaim(): UNCLAIM %pM on vid %d (sent by %pM)...\n", claim_addr, vid, backbone_gw->orig); batadv_bla_del_claim(bat_priv, claim_addr, vid); batadv_backbone_gw_free_ref(backbone_gw); return 1; } /* check for CLAIM frame, return 1 if handled */ static int batadv_handle_claim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, uint8_t *backbone_addr, uint8_t *claim_addr, short vid) { struct batadv_backbone_gw *backbone_gw; /* register the gateway if not yet available, and add the claim. */ backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid); if (unlikely(!backbone_gw)) return 1; /* this must be a CLAIM frame */ batadv_bla_add_claim(bat_priv, claim_addr, vid, backbone_gw); if (batadv_compare_eth(backbone_addr, primary_if->net_dev->dev_addr)) batadv_bla_send_claim(bat_priv, claim_addr, vid, BATADV_CLAIM_TYPE_ADD); /* TODO: we could call something like tt_local_del() here. */ batadv_backbone_gw_free_ref(backbone_gw); return 1; } /** * batadv_check_claim_group * @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 batadv_check_claim_group(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, uint8_t *hw_src, uint8_t *hw_dst, struct ethhdr *ethhdr) { uint8_t *backbone_addr; struct batadv_orig_node *orig_node; struct batadv_bla_claim_dst *bla_dst, *bla_dst_own; bla_dst = (struct batadv_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 BATADV_CLAIM_TYPE_ADD: backbone_addr = hw_src; break; case BATADV_CLAIM_TYPE_REQUEST: case BATADV_CLAIM_TYPE_ANNOUNCE: case BATADV_CLAIM_TYPE_DEL: backbone_addr = ethhdr->h_source; break; default: return 0; } /* don't accept claim frames from ourselves */ if (batadv_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 = batadv_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)) { batadv_dbg(BATADV_DBG_BLA, bat_priv, "taking other backbones claim group: %04x\n", ntohs(bla_dst->group)); bla_dst_own->group = bla_dst->group; } batadv_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 batadv_bla_process_claim(struct batadv_priv *bat_priv, struct batadv_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 batadv_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 batadv_bla_claim_dst *)hw_dst; /* check if it is a claim frame. */ ret = batadv_check_claim_group(bat_priv, primary_if, hw_src, hw_dst, ethhdr); if (ret == 1) batadv_dbg(BATADV_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 */ batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); /* check for the different types of claim frames ... */ switch (bla_dst->type) { case BATADV_CLAIM_TYPE_ADD: if (batadv_handle_claim(bat_priv, primary_if, hw_src, ethhdr->h_source, vid)) return 1; break; case BATADV_CLAIM_TYPE_DEL: if (batadv_handle_unclaim(bat_priv, primary_if, ethhdr->h_source, hw_src, vid)) return 1; break; case BATADV_CLAIM_TYPE_ANNOUNCE: if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source, vid)) return 1; break; case BATADV_CLAIM_TYPE_REQUEST: if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr, vid)) return 1; break; } batadv_dbg(BATADV_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 batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now) { struct batadv_backbone_gw *backbone_gw; struct hlist_node *node, *node_tmp; struct hlist_head *head; struct batadv_hashtable *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 (!batadv_has_timed_out(backbone_gw->lasttime, BATADV_BLA_BACKBONE_TIMEOUT)) continue; batadv_dbg(BATADV_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); batadv_bla_del_backbone_claims(backbone_gw); hlist_del_rcu(node); batadv_backbone_gw_free_ref(backbone_gw); } spin_unlock_bh(list_lock); } } /** * batadv_bla_purge_claims * @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 batadv_bla_purge_claims(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, int now) { struct batadv_claim *claim; struct hlist_node *node; struct hlist_head *head; struct batadv_hashtable *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 (!batadv_compare_eth(claim->backbone_gw->orig, primary_if->net_dev->dev_addr)) continue; if (!batadv_has_timed_out(claim->lasttime, BATADV_BLA_CLAIM_TIMEOUT)) continue; batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla_purge_claims(): %pM, vid %d, time out\n", claim->addr, claim->vid); purge_now: batadv_handle_unclaim(bat_priv, primary_if, claim->backbone_gw->orig, claim->addr, claim->vid); } rcu_read_unlock(); } } /** * batadv_bla_update_orig_address * @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 batadv_bla_update_orig_address(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, struct batadv_hard_iface *oldif) { struct batadv_backbone_gw *backbone_gw; struct hlist_node *node; struct hlist_head *head; struct batadv_hashtable *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) { batadv_bla_purge_claims(bat_priv, NULL, 1); batadv_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 (!batadv_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. */ batadv_bla_send_announce(bat_priv, backbone_gw); } rcu_read_unlock(); } } /* (re)start the timer */ static void batadv_bla_start_timer(struct batadv_priv *bat_priv) { INIT_DELAYED_WORK(&bat_priv->bla_work, batadv_bla_periodic_work); queue_delayed_work(batadv_event_workqueue, &bat_priv->bla_work, msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH)); } /* periodic work to do: * * purge structures when they are too old * * send announcements */ static void batadv_bla_periodic_work(struct work_struct *work) { struct delayed_work *delayed_work = container_of(work, struct delayed_work, work); struct batadv_priv *bat_priv; struct hlist_node *node; struct hlist_head *head; struct batadv_backbone_gw *backbone_gw; struct batadv_hashtable *hash; struct batadv_hard_iface *primary_if; int i; bat_priv = container_of(delayed_work, struct batadv_priv, bla_work); primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto out; batadv_bla_purge_claims(bat_priv, primary_if, 0); batadv_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 (!batadv_compare_eth(backbone_gw->orig, primary_if->net_dev->dev_addr)) continue; backbone_gw->lasttime = jiffies; batadv_bla_send_announce(bat_priv, backbone_gw); } rcu_read_unlock(); } out: if (primary_if) batadv_hardif_free_ref(primary_if); batadv_bla_start_timer(bat_priv); } /* The hash for claim and backbone hash receive the same key because they * are getting initialized by hash_new with the same key. Reinitializing * them with to different keys to allow nested locking without generating * lockdep warnings */ static struct lock_class_key batadv_claim_hash_lock_class_key; static struct lock_class_key batadv_backbone_hash_lock_class_key; /* initialize all bla structures */ int batadv_bla_init(struct batadv_priv *bat_priv) { int i; uint8_t claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00}; struct batadv_hard_iface *primary_if; batadv_dbg(BATADV_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 = batadv_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)); batadv_hardif_free_ref(primary_if); } else { bat_priv->claim_dest.group = 0; /* will be set later */ } /* initialize the duplicate list */ for (i = 0; i < BATADV_DUPLIST_SIZE; i++) bat_priv->bcast_duplist[i].entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT); bat_priv->bcast_duplist_curr = 0; if (bat_priv->claim_hash) return 0; bat_priv->claim_hash = batadv_hash_new(128); bat_priv->backbone_hash = batadv_hash_new(32); if (!bat_priv->claim_hash || !bat_priv->backbone_hash) return -ENOMEM; batadv_hash_set_lock_class(bat_priv->claim_hash, &batadv_claim_hash_lock_class_key); batadv_hash_set_lock_class(bat_priv->backbone_hash, &batadv_backbone_hash_lock_class_key); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n"); batadv_bla_start_timer(bat_priv); return 0; } /** * batadv_bla_check_bcast_duplist * @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 batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, struct batadv_bcast_packet *bcast_packet, int hdr_size) { int i, length, curr; uint8_t *content; uint16_t crc; struct batadv_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 < BATADV_DUPLIST_SIZE; i++) { curr = (bat_priv->bcast_duplist_curr + i) % BATADV_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 (batadv_has_timed_out(entry->entrytime, BATADV_DUPLIST_TIMEOUT)) break; if (entry->crc != crc) continue; if (batadv_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 + BATADV_DUPLIST_SIZE - 1); curr %= BATADV_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 batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, uint8_t *orig) { struct batadv_hashtable *hash = bat_priv->backbone_hash; struct hlist_head *head; struct hlist_node *node; struct batadv_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 (batadv_compare_eth(backbone_gw->orig, orig)) { rcu_read_unlock(); return 1; } } rcu_read_unlock(); } return 0; } /** * batadv_bla_is_backbone_gw * @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 batadv_bla_is_backbone_gw(struct sk_buff *skb, struct batadv_orig_node *orig_node, int hdr_size) { struct ethhdr *ethhdr; struct vlan_ethhdr *vhdr; struct batadv_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 = batadv_backbone_hash_find(orig_node->bat_priv, orig_node->orig, vid); if (!backbone_gw) return 0; batadv_backbone_gw_free_ref(backbone_gw); return 1; } /* free all bla structures (for softinterface free or module unload) */ void batadv_bla_free(struct batadv_priv *bat_priv) { struct batadv_hard_iface *primary_if; cancel_delayed_work_sync(&bat_priv->bla_work); primary_if = batadv_primary_if_get_selected(bat_priv); if (bat_priv->claim_hash) { batadv_bla_purge_claims(bat_priv, primary_if, 1); batadv_hash_destroy(bat_priv->claim_hash); bat_priv->claim_hash = NULL; } if (bat_priv->backbone_hash) { batadv_bla_purge_backbone_gw(bat_priv, 1); batadv_hash_destroy(bat_priv->backbone_hash); bat_priv->backbone_hash = NULL; } if (primary_if) batadv_hardif_free_ref(primary_if); } /** * batadv_bla_rx * @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 batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, short vid) { struct ethhdr *ethhdr; struct batadv_claim search_claim, *claim = NULL; struct batadv_hard_iface *primary_if; int ret; ethhdr = (struct ethhdr *)skb_mac_header(skb); primary_if = batadv_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 = batadv_claim_hash_find(bat_priv, &search_claim); if (!claim) { /* possible optimization: race for a claim */ /* No claim exists yet, claim it for us! */ batadv_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 (batadv_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. */ batadv_handle_claim(bat_priv, primary_if, primary_if->net_dev->dev_addr, ethhdr->h_source, vid); goto allow; } allow: batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); ret = 0; goto out; handled: kfree_skb(skb); ret = 1; out: if (primary_if) batadv_hardif_free_ref(primary_if); if (claim) batadv_claim_free_ref(claim); return ret; } /** * batadv_bla_tx * @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 batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb, short vid) { struct ethhdr *ethhdr; struct batadv_claim search_claim, *claim = NULL; struct batadv_hard_iface *primary_if; int ret = 0; primary_if = batadv_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 (batadv_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 = batadv_claim_hash_find(bat_priv, &search_claim); /* if no claim exists, allow it. */ if (!claim) goto allow; /* check if we are responsible. */ if (batadv_compare_eth(claim->backbone_gw->orig, primary_if->net_dev->dev_addr)) { /* if yes, the client has roamed and we have * to unclaim it. */ batadv_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: batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); ret = 0; goto out; handled: ret = 1; out: if (primary_if) batadv_hardif_free_ref(primary_if); if (claim) batadv_claim_free_ref(claim); return ret; } int batadv_bla_claim_table_seq_print_text(struct seq_file *seq, void *offset) { struct net_device *net_dev = (struct net_device *)seq->private; struct batadv_priv *bat_priv = netdev_priv(net_dev); struct batadv_hashtable *hash = bat_priv->claim_hash; struct batadv_claim *claim; struct batadv_hard_iface *primary_if; struct hlist_node *node; struct hlist_head *head; uint32_t i; bool is_own; int ret = 0; uint8_t *primary_addr; primary_if = batadv_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 != BATADV_IF_ACTIVE) { ret = seq_printf(seq, "BATMAN mesh %s disabled - primary interface not active\n", net_dev->name); goto out; } primary_addr = primary_if->net_dev->dev_addr; seq_printf(seq, "Claims announced for the mesh %s (orig %pM, group id %04x)\n", net_dev->name, primary_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 = batadv_compare_eth(claim->backbone_gw->orig, primary_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) batadv_hardif_free_ref(primary_if); return ret; }