// SPDX-License-Identifier: GPL-2.0 /* Copyright (C) B.A.T.M.A.N. contributors: * * Simon Wunderlich */ #include "bridge_loop_avoidance.h" #include "main.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "hard-interface.h" #include "hash.h" #include "log.h" #include "netlink.h" #include "originator.h" #include "soft-interface.h" #include "translation-table.h" static const u8 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_bla_backbone_gw *backbone_gw); /** * batadv_choose_claim() - choose the right bucket for a claim. * @data: data to hash * @size: size of the hash table * * Return: the hash index of the claim */ static inline u32 batadv_choose_claim(const void *data, u32 size) { const struct batadv_bla_claim *claim = data; u32 hash = 0; hash = jhash(&claim->addr, sizeof(claim->addr), hash); hash = jhash(&claim->vid, sizeof(claim->vid), hash); return hash % size; } /** * batadv_choose_backbone_gw() - choose the right bucket for a backbone gateway. * @data: data to hash * @size: size of the hash table * * Return: the hash index of the backbone gateway */ static inline u32 batadv_choose_backbone_gw(const void *data, u32 size) { const struct batadv_bla_backbone_gw *gw; u32 hash = 0; gw = data; hash = jhash(&gw->orig, sizeof(gw->orig), hash); hash = jhash(&gw->vid, sizeof(gw->vid), hash); return hash % size; } /** * batadv_compare_backbone_gw() - compare address and vid of two backbone gws * @node: list node of the first entry to compare * @data2: pointer to the second backbone gateway * * Return: true if the backbones have the same data, false otherwise */ static bool batadv_compare_backbone_gw(const struct hlist_node *node, const void *data2) { const void *data1 = container_of(node, struct batadv_bla_backbone_gw, hash_entry); const struct batadv_bla_backbone_gw *gw1 = data1; const struct batadv_bla_backbone_gw *gw2 = data2; if (!batadv_compare_eth(gw1->orig, gw2->orig)) return false; if (gw1->vid != gw2->vid) return false; return true; } /** * batadv_compare_claim() - compare address and vid of two claims * @node: list node of the first entry to compare * @data2: pointer to the second claims * * Return: true if the claim have the same data, 0 otherwise */ static bool batadv_compare_claim(const struct hlist_node *node, const void *data2) { const void *data1 = container_of(node, struct batadv_bla_claim, hash_entry); const struct batadv_bla_claim *cl1 = data1; const struct batadv_bla_claim *cl2 = data2; if (!batadv_compare_eth(cl1->addr, cl2->addr)) return false; if (cl1->vid != cl2->vid) return false; return true; } /** * batadv_backbone_gw_release() - release backbone gw from lists and queue for * free after rcu grace period * @ref: kref pointer of the backbone gw */ static void batadv_backbone_gw_release(struct kref *ref) { struct batadv_bla_backbone_gw *backbone_gw; backbone_gw = container_of(ref, struct batadv_bla_backbone_gw, refcount); kfree_rcu(backbone_gw, rcu); } /** * batadv_backbone_gw_put() - decrement the backbone gw refcounter and possibly * release it * @backbone_gw: backbone gateway to be free'd */ static void batadv_backbone_gw_put(struct batadv_bla_backbone_gw *backbone_gw) { if (!backbone_gw) return; kref_put(&backbone_gw->refcount, batadv_backbone_gw_release); } /** * batadv_claim_release() - release claim from lists and queue for free after * rcu grace period * @ref: kref pointer of the claim */ static void batadv_claim_release(struct kref *ref) { struct batadv_bla_claim *claim; struct batadv_bla_backbone_gw *old_backbone_gw; claim = container_of(ref, struct batadv_bla_claim, refcount); spin_lock_bh(&claim->backbone_lock); old_backbone_gw = claim->backbone_gw; claim->backbone_gw = NULL; spin_unlock_bh(&claim->backbone_lock); spin_lock_bh(&old_backbone_gw->crc_lock); old_backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); spin_unlock_bh(&old_backbone_gw->crc_lock); batadv_backbone_gw_put(old_backbone_gw); kfree_rcu(claim, rcu); } /** * batadv_claim_put() - decrement the claim refcounter and possibly release it * @claim: claim to be free'd */ static void batadv_claim_put(struct batadv_bla_claim *claim) { if (!claim) return; kref_put(&claim->refcount, batadv_claim_release); } /** * batadv_claim_hash_find() - looks for a claim in the claim hash * @bat_priv: the bat priv with all the soft interface information * @data: search data (may be local/static data) * * Return: claim if found or NULL otherwise. */ static struct batadv_bla_claim * batadv_claim_hash_find(struct batadv_priv *bat_priv, struct batadv_bla_claim *data) { struct batadv_hashtable *hash = bat_priv->bla.claim_hash; struct hlist_head *head; struct batadv_bla_claim *claim; struct batadv_bla_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, head, hash_entry) { if (!batadv_compare_claim(&claim->hash_entry, data)) continue; if (!kref_get_unless_zero(&claim->refcount)) continue; claim_tmp = claim; break; } rcu_read_unlock(); return claim_tmp; } /** * batadv_backbone_hash_find() - looks for a backbone gateway in the hash * @bat_priv: the bat priv with all the soft interface information * @addr: the address of the originator * @vid: the VLAN ID * * Return: backbone gateway if found or NULL otherwise */ static struct batadv_bla_backbone_gw * batadv_backbone_hash_find(struct batadv_priv *bat_priv, const u8 *addr, unsigned short vid) { struct batadv_hashtable *hash = bat_priv->bla.backbone_hash; struct hlist_head *head; struct batadv_bla_backbone_gw search_entry, *backbone_gw; struct batadv_bla_backbone_gw *backbone_gw_tmp = NULL; int index; if (!hash) return NULL; ether_addr_copy(search_entry.orig, addr); 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, head, hash_entry) { if (!batadv_compare_backbone_gw(&backbone_gw->hash_entry, &search_entry)) continue; if (!kref_get_unless_zero(&backbone_gw->refcount)) continue; backbone_gw_tmp = backbone_gw; break; } rcu_read_unlock(); return backbone_gw_tmp; } /** * batadv_bla_del_backbone_claims() - delete all claims for a backbone * @backbone_gw: backbone gateway where the claims should be removed */ static void batadv_bla_del_backbone_claims(struct batadv_bla_backbone_gw *backbone_gw) { struct batadv_hashtable *hash; struct hlist_node *node_tmp; struct hlist_head *head; struct batadv_bla_claim *claim; int i; spinlock_t *list_lock; /* protects write access to the hash lists */ hash = backbone_gw->bat_priv->bla.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_tmp, head, hash_entry) { if (claim->backbone_gw != backbone_gw) continue; batadv_claim_put(claim); hlist_del_rcu(&claim->hash_entry); } spin_unlock_bh(list_lock); } /* all claims gone, initialize CRC */ spin_lock_bh(&backbone_gw->crc_lock); backbone_gw->crc = BATADV_BLA_CRC_INIT; spin_unlock_bh(&backbone_gw->crc_lock); } /** * batadv_bla_send_claim() - sends a claim frame according to the provided info * @bat_priv: the bat priv with all the soft interface information * @mac: 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, const u8 *mac, unsigned short vid, int claimtype) { struct sk_buff *skb; struct ethhdr *ethhdr; struct batadv_hard_iface *primary_if; struct net_device *soft_iface; u8 *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->bla.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:YY:YY * with XX = claim type * and YY:YY = group id */ (u8 *)&local_claim_dest); if (!skb) goto out; ethhdr = (struct ethhdr *)skb->data; hw_src = (u8 *)ethhdr + ETH_HLEN + sizeof(struct arphdr); /* now we pretend that the client would have sent this ... */ switch (claimtype) { case BATADV_CLAIM_TYPE_CLAIM: /* normal claim frame * set Ethernet SRC to the clients mac */ ether_addr_copy(ethhdr->h_source, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): CLAIM %pM on vid %d\n", __func__, mac, batadv_print_vid(vid)); break; case BATADV_CLAIM_TYPE_UNCLAIM: /* unclaim frame * set HW SRC to the clients mac */ ether_addr_copy(hw_src, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): UNCLAIM %pM on vid %d\n", __func__, mac, batadv_print_vid(vid)); break; case BATADV_CLAIM_TYPE_ANNOUNCE: /* announcement frame * set HW SRC to the special mac containing the crc */ ether_addr_copy(hw_src, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): ANNOUNCE of %pM on vid %d\n", __func__, ethhdr->h_source, batadv_print_vid(vid)); break; case BATADV_CLAIM_TYPE_REQUEST: /* request frame * set HW SRC and header destination to the receiving backbone * gws mac */ ether_addr_copy(hw_src, mac); ether_addr_copy(ethhdr->h_dest, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): REQUEST of %pM to %pM on vid %d\n", __func__, ethhdr->h_source, ethhdr->h_dest, batadv_print_vid(vid)); break; case BATADV_CLAIM_TYPE_LOOPDETECT: ether_addr_copy(ethhdr->h_source, mac); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): LOOPDETECT of %pM to %pM on vid %d\n", __func__, ethhdr->h_source, ethhdr->h_dest, batadv_print_vid(vid)); break; } if (vid & BATADV_VLAN_HAS_TAG) { skb = vlan_insert_tag(skb, htons(ETH_P_8021Q), vid & VLAN_VID_MASK); if (!skb) goto out; } skb_reset_mac_header(skb); skb->protocol = eth_type_trans(skb, soft_iface); batadv_inc_counter(bat_priv, BATADV_CNT_RX); batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES, skb->len + ETH_HLEN); netif_rx(skb); out: batadv_hardif_put(primary_if); } /** * batadv_bla_loopdetect_report() - worker for reporting the loop * @work: work queue item * * Throws an uevent, as the loopdetect check function can't do that itself * since the kernel may sleep while throwing uevents. */ static void batadv_bla_loopdetect_report(struct work_struct *work) { struct batadv_bla_backbone_gw *backbone_gw; struct batadv_priv *bat_priv; char vid_str[6] = { '\0' }; backbone_gw = container_of(work, struct batadv_bla_backbone_gw, report_work); bat_priv = backbone_gw->bat_priv; batadv_info(bat_priv->soft_iface, "Possible loop on VLAN %d detected which can't be handled by BLA - please check your network setup!\n", batadv_print_vid(backbone_gw->vid)); snprintf(vid_str, sizeof(vid_str), "%d", batadv_print_vid(backbone_gw->vid)); vid_str[sizeof(vid_str) - 1] = 0; batadv_throw_uevent(bat_priv, BATADV_UEV_BLA, BATADV_UEV_LOOPDETECT, vid_str); batadv_backbone_gw_put(backbone_gw); } /** * batadv_bla_get_backbone_gw() - finds or creates a backbone gateway * @bat_priv: the bat priv with all the soft interface information * @orig: the mac address of the originator * @vid: the VLAN ID * @own_backbone: set if the requested backbone is local * * Return: the (possibly created) backbone gateway or NULL on error */ static struct batadv_bla_backbone_gw * batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig, unsigned short vid, bool own_backbone) { struct batadv_bla_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, "%s(): not found (%pM, %d), creating new entry\n", __func__, orig, batadv_print_vid(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; spin_lock_init(&entry->crc_lock); atomic_set(&entry->request_sent, 0); atomic_set(&entry->wait_periods, 0); ether_addr_copy(entry->orig, orig); INIT_WORK(&entry->report_work, batadv_bla_loopdetect_report); kref_init(&entry->refcount); kref_get(&entry->refcount); hash_added = batadv_hash_add(bat_priv->bla.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 entry on this VLAN */ orig_node = batadv_orig_hash_find(bat_priv, orig); if (orig_node) { batadv_tt_global_del_orig(bat_priv, orig_node, vid, "became a backbone gateway"); batadv_orig_node_put(orig_node); } if (own_backbone) { batadv_bla_send_announce(bat_priv, entry); /* this will be decreased in the worker thread */ atomic_inc(&entry->request_sent); atomic_set(&entry->wait_periods, BATADV_BLA_WAIT_PERIODS); atomic_inc(&bat_priv->bla.num_requests); } return entry; } /** * batadv_bla_update_own_backbone_gw() - updates the own backbone gw for a VLAN * @bat_priv: the bat priv with all the soft interface information * @primary_if: the selected primary interface * @vid: VLAN identifier * * 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, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; backbone_gw = batadv_bla_get_backbone_gw(bat_priv, primary_if->net_dev->dev_addr, vid, true); if (unlikely(!backbone_gw)) return; backbone_gw->lasttime = jiffies; batadv_backbone_gw_put(backbone_gw); } /** * batadv_bla_answer_request() - answer a bla request by sending own claims * @bat_priv: the bat priv with all the soft interface information * @primary_if: interface where the request came on * @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, unsigned short vid) { struct hlist_head *head; struct batadv_hashtable *hash; struct batadv_bla_claim *claim; struct batadv_bla_backbone_gw *backbone_gw; int i; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): received a claim request, send all of our own claims again\n", __func__); backbone_gw = batadv_backbone_hash_find(bat_priv, primary_if->net_dev->dev_addr, vid); if (!backbone_gw) return; hash = bat_priv->bla.claim_hash; for (i = 0; i < hash->size; i++) { head = &hash->table[i]; rcu_read_lock(); hlist_for_each_entry_rcu(claim, 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_CLAIM); } rcu_read_unlock(); } /* finally, send an announcement frame */ batadv_bla_send_announce(bat_priv, backbone_gw); batadv_backbone_gw_put(backbone_gw); } /** * batadv_bla_send_request() - send a request to repeat claims * @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_bla_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); } } /** * batadv_bla_send_announce() - Send an announcement frame * @bat_priv: the bat priv with all the soft interface information * @backbone_gw: our backbone gateway which should be announced */ static void batadv_bla_send_announce(struct batadv_priv *bat_priv, struct batadv_bla_backbone_gw *backbone_gw) { u8 mac[ETH_ALEN]; __be16 crc; memcpy(mac, batadv_announce_mac, 4); spin_lock_bh(&backbone_gw->crc_lock); crc = htons(backbone_gw->crc); spin_unlock_bh(&backbone_gw->crc_lock); 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 u8 *mac, const unsigned short vid, struct batadv_bla_backbone_gw *backbone_gw) { struct batadv_bla_backbone_gw *old_backbone_gw; struct batadv_bla_claim *claim; struct batadv_bla_claim search_claim; bool remove_crc = false; int hash_added; ether_addr_copy(search_claim.addr, mac); 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; ether_addr_copy(claim->addr, mac); spin_lock_init(&claim->backbone_lock); claim->vid = vid; claim->lasttime = jiffies; kref_get(&backbone_gw->refcount); claim->backbone_gw = backbone_gw; kref_init(&claim->refcount); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): adding new entry %pM, vid %d to hash ...\n", __func__, mac, batadv_print_vid(vid)); kref_get(&claim->refcount); hash_added = batadv_hash_add(bat_priv->bla.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, "%s(): changing ownership for %pM, vid %d to gw %pM\n", __func__, mac, batadv_print_vid(vid), backbone_gw->orig); remove_crc = true; } /* replace backbone_gw atomically and adjust reference counters */ spin_lock_bh(&claim->backbone_lock); old_backbone_gw = claim->backbone_gw; kref_get(&backbone_gw->refcount); claim->backbone_gw = backbone_gw; spin_unlock_bh(&claim->backbone_lock); if (remove_crc) { /* remove claim address from old backbone_gw */ spin_lock_bh(&old_backbone_gw->crc_lock); old_backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); spin_unlock_bh(&old_backbone_gw->crc_lock); } batadv_backbone_gw_put(old_backbone_gw); /* add claim address to new backbone_gw */ spin_lock_bh(&backbone_gw->crc_lock); backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); spin_unlock_bh(&backbone_gw->crc_lock); backbone_gw->lasttime = jiffies; claim_free_ref: batadv_claim_put(claim); } /** * batadv_bla_claim_get_backbone_gw() - Get valid reference for backbone_gw of * claim * @claim: claim whose backbone_gw should be returned * * Return: valid reference to claim::backbone_gw */ static struct batadv_bla_backbone_gw * batadv_bla_claim_get_backbone_gw(struct batadv_bla_claim *claim) { struct batadv_bla_backbone_gw *backbone_gw; spin_lock_bh(&claim->backbone_lock); backbone_gw = claim->backbone_gw; kref_get(&backbone_gw->refcount); spin_unlock_bh(&claim->backbone_lock); return backbone_gw; } /** * batadv_bla_del_claim() - delete a claim from the claim hash * @bat_priv: the bat priv with all the soft interface information * @mac: mac address of the claim to be removed * @vid: VLAN id for the claim to be removed */ static void batadv_bla_del_claim(struct batadv_priv *bat_priv, const u8 *mac, const unsigned short vid) { struct batadv_bla_claim search_claim, *claim; struct batadv_bla_claim *claim_removed_entry; struct hlist_node *claim_removed_node; ether_addr_copy(search_claim.addr, mac); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim); if (!claim) return; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): %pM, vid %d\n", __func__, mac, batadv_print_vid(vid)); claim_removed_node = batadv_hash_remove(bat_priv->bla.claim_hash, batadv_compare_claim, batadv_choose_claim, claim); if (!claim_removed_node) goto free_claim; /* reference from the hash is gone */ claim_removed_entry = hlist_entry(claim_removed_node, struct batadv_bla_claim, hash_entry); batadv_claim_put(claim_removed_entry); free_claim: /* don't need the reference from hash_find() anymore */ batadv_claim_put(claim); } /** * batadv_handle_announce() - check for ANNOUNCE frame * @bat_priv: the bat priv with all the soft interface information * @an_addr: announcement mac address (ARP Sender HW address) * @backbone_addr: originator address of the sender (Ethernet source MAC) * @vid: the VLAN ID of the frame * * Return: true if handled */ static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr, u8 *backbone_addr, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; u16 backbone_crc, crc; if (memcmp(an_addr, batadv_announce_mac, 4) != 0) return false; backbone_gw = batadv_bla_get_backbone_gw(bat_priv, backbone_addr, vid, false); if (unlikely(!backbone_gw)) return true; /* handle as ANNOUNCE frame */ backbone_gw->lasttime = jiffies; crc = ntohs(*((__force __be16 *)(&an_addr[4]))); batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): ANNOUNCE vid %d (sent by %pM)... CRC = %#.4x\n", __func__, batadv_print_vid(vid), backbone_gw->orig, crc); spin_lock_bh(&backbone_gw->crc_lock); backbone_crc = backbone_gw->crc; spin_unlock_bh(&backbone_gw->crc_lock); if (backbone_crc != crc) { batadv_dbg(BATADV_DBG_BLA, backbone_gw->bat_priv, "%s(): CRC FAILED for %pM/%d (my = %#.4x, sent = %#.4x)\n", __func__, backbone_gw->orig, batadv_print_vid(backbone_gw->vid), backbone_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_put(backbone_gw); return true; } /** * batadv_handle_request() - check for REQUEST frame * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary hard interface of this batman soft interface * @backbone_addr: backbone address to be requested (ARP sender HW MAC) * @ethhdr: ethernet header of a packet * @vid: the VLAN ID of the frame * * Return: true if handled */ static bool batadv_handle_request(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, u8 *backbone_addr, struct ethhdr *ethhdr, unsigned short vid) { /* check for REQUEST frame */ if (!batadv_compare_eth(backbone_addr, ethhdr->h_dest)) return false; /* 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 true; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): REQUEST vid %d (sent by %pM)...\n", __func__, batadv_print_vid(vid), ethhdr->h_source); batadv_bla_answer_request(bat_priv, primary_if, vid); return true; } /** * batadv_handle_unclaim() - check for UNCLAIM frame * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary hard interface of this batman soft interface * @backbone_addr: originator address of the backbone (Ethernet source) * @claim_addr: Client to be unclaimed (ARP sender HW MAC) * @vid: the VLAN ID of the frame * * Return: true if handled */ static bool batadv_handle_unclaim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, const u8 *backbone_addr, const u8 *claim_addr, unsigned short vid) { struct batadv_bla_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_UNCLAIM); backbone_gw = batadv_backbone_hash_find(bat_priv, backbone_addr, vid); if (!backbone_gw) return true; /* this must be an UNCLAIM frame */ batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): UNCLAIM %pM on vid %d (sent by %pM)...\n", __func__, claim_addr, batadv_print_vid(vid), backbone_gw->orig); batadv_bla_del_claim(bat_priv, claim_addr, vid); batadv_backbone_gw_put(backbone_gw); return true; } /** * batadv_handle_claim() - check for CLAIM frame * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary hard interface of this batman soft interface * @backbone_addr: originator address of the backbone (Ethernet Source) * @claim_addr: client mac address to be claimed (ARP sender HW MAC) * @vid: the VLAN ID of the frame * * Return: true if handled */ static bool batadv_handle_claim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, const u8 *backbone_addr, const u8 *claim_addr, unsigned short vid) { struct batadv_bla_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, false); if (unlikely(!backbone_gw)) return true; /* 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_CLAIM); /* TODO: we could call something like tt_local_del() here. */ batadv_backbone_gw_put(backbone_gw); return true; } /** * batadv_check_claim_group() - check for claim group membership * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary interface of this batman interface * @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 it's on the same group. * This function also applies the group ID of the sender * if it is in the same mesh. * * Return: * 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, u8 *hw_src, u8 *hw_dst, struct ethhdr *ethhdr) { u8 *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->bla.claim_dest; /* if announcement packet, use the source, * otherwise assume it is in the hw_src */ switch (bla_dst->type) { case BATADV_CLAIM_TYPE_CLAIM: backbone_addr = hw_src; break; case BATADV_CLAIM_TYPE_REQUEST: case BATADV_CLAIM_TYPE_ANNOUNCE: case BATADV_CLAIM_TYPE_UNCLAIM: 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); /* don't 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: %#.4x\n", ntohs(bla_dst->group)); bla_dst_own->group = bla_dst->group; } batadv_orig_node_put(orig_node); return 2; } /** * batadv_bla_process_claim() - Check if this is a claim frame, and process it * @bat_priv: the bat priv with all the soft interface information * @primary_if: the primary hard interface of this batman soft interface * @skb: the frame to be checked * * Return: true if it was a claim frame, otherwise return false to * tell the callee that it can use the frame on its own. */ static bool batadv_bla_process_claim(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, struct sk_buff *skb) { struct batadv_bla_claim_dst *bla_dst, *bla_dst_own; u8 *hw_src, *hw_dst; struct vlan_hdr *vhdr, vhdr_buf; struct ethhdr *ethhdr; struct arphdr *arphdr; unsigned short vid; int vlan_depth = 0; __be16 proto; int headlen; int ret; vid = batadv_get_vid(skb, 0); ethhdr = eth_hdr(skb); proto = ethhdr->h_proto; headlen = ETH_HLEN; if (vid & BATADV_VLAN_HAS_TAG) { /* Traverse the VLAN/Ethertypes. * * At this point it is known that the first protocol is a VLAN * header, so start checking at the encapsulated protocol. * * The depth of the VLAN headers is recorded to drop BLA claim * frames encapsulated into multiple VLAN headers (QinQ). */ do { vhdr = skb_header_pointer(skb, headlen, VLAN_HLEN, &vhdr_buf); if (!vhdr) return false; proto = vhdr->h_vlan_encapsulated_proto; headlen += VLAN_HLEN; vlan_depth++; } while (proto == htons(ETH_P_8021Q)); } if (proto != htons(ETH_P_ARP)) return false; /* 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 false; /* pskb_may_pull() may have modified the pointers, get ethhdr again */ ethhdr = eth_hdr(skb); arphdr = (struct arphdr *)((u8 *)ethhdr + headlen); /* Check whether the ARP frame carries a valid * IP information */ if (arphdr->ar_hrd != htons(ARPHRD_ETHER)) return false; if (arphdr->ar_pro != htons(ETH_P_IP)) return false; if (arphdr->ar_hln != ETH_ALEN) return false; if (arphdr->ar_pln != 4) return false; hw_src = (u8 *)arphdr + sizeof(struct arphdr); hw_dst = hw_src + ETH_ALEN + 4; bla_dst = (struct batadv_bla_claim_dst *)hw_dst; bla_dst_own = &bat_priv->bla.claim_dest; /* check if it is a claim frame in general */ if (memcmp(bla_dst->magic, bla_dst_own->magic, sizeof(bla_dst->magic)) != 0) return false; /* check if there is a claim frame encapsulated deeper in (QinQ) and * drop that, as this is not supported by BLA but should also not be * sent via the mesh. */ if (vlan_depth > 1) return true; /* Let the loopdetect frames on the mesh in any case. */ if (bla_dst->type == BATADV_CLAIM_TYPE_LOOPDETECT) return false; /* 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, "%s(): received a claim frame from another group. From: %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n", __func__, ethhdr->h_source, batadv_print_vid(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_CLAIM: if (batadv_handle_claim(bat_priv, primary_if, hw_src, ethhdr->h_source, vid)) return true; break; case BATADV_CLAIM_TYPE_UNCLAIM: if (batadv_handle_unclaim(bat_priv, primary_if, ethhdr->h_source, hw_src, vid)) return true; break; case BATADV_CLAIM_TYPE_ANNOUNCE: if (batadv_handle_announce(bat_priv, hw_src, ethhdr->h_source, vid)) return true; break; case BATADV_CLAIM_TYPE_REQUEST: if (batadv_handle_request(bat_priv, primary_if, hw_src, ethhdr, vid)) return true; break; } batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): ERROR - this looks like a claim frame, but is useless. eth src %pM on vid %d ...(hw_src %pM, hw_dst %pM)\n", __func__, ethhdr->h_source, batadv_print_vid(vid), hw_src, hw_dst); return true; } /** * batadv_bla_purge_backbone_gw() - Remove backbone gateways after a timeout or * immediately * @bat_priv: the bat priv with all the soft interface information * @now: whether the whole hash shall be wiped now * * 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_bla_backbone_gw *backbone_gw; struct hlist_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->bla.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_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, "%s(): backbone gw %pM timed out\n", __func__, 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(&backbone_gw->hash_entry); batadv_backbone_gw_put(backbone_gw); } spin_unlock_bh(list_lock); } } /** * batadv_bla_purge_claims() - Remove claims after a timeout or immediately * @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_bla_backbone_gw *backbone_gw; struct batadv_bla_claim *claim; struct hlist_head *head; struct batadv_hashtable *hash; int i; hash = bat_priv->bla.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, head, hash_entry) { backbone_gw = batadv_bla_claim_get_backbone_gw(claim); if (now) goto purge_now; if (!batadv_compare_eth(backbone_gw->orig, primary_if->net_dev->dev_addr)) goto skip; if (!batadv_has_timed_out(claim->lasttime, BATADV_BLA_CLAIM_TIMEOUT)) goto skip; batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): timed out.\n", __func__); purge_now: batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): %pM, vid %d\n", __func__, claim->addr, claim->vid); batadv_handle_unclaim(bat_priv, primary_if, backbone_gw->orig, claim->addr, claim->vid); skip: batadv_backbone_gw_put(backbone_gw); } rcu_read_unlock(); } } /** * batadv_bla_update_orig_address() - Update the backbone gateways when the own * originator address changes * @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 */ void batadv_bla_update_orig_address(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, struct batadv_hard_iface *oldif) { struct batadv_bla_backbone_gw *backbone_gw; struct hlist_head *head; struct batadv_hashtable *hash; __be16 group; int i; /* reset bridge loop avoidance group id */ group = htons(crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN)); bat_priv->bla.claim_dest.group = group; /* purge everything when bridge loop avoidance is turned off */ if (!atomic_read(&bat_priv->bridge_loop_avoidance)) oldif = NULL; if (!oldif) { batadv_bla_purge_claims(bat_priv, NULL, 1); batadv_bla_purge_backbone_gw(bat_priv, 1); return; } hash = bat_priv->bla.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, head, hash_entry) { /* own orig still holds the old value. */ if (!batadv_compare_eth(backbone_gw->orig, oldif->net_dev->dev_addr)) continue; ether_addr_copy(backbone_gw->orig, primary_if->net_dev->dev_addr); /* 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(); } } /** * batadv_bla_send_loopdetect() - send a loopdetect frame * @bat_priv: the bat priv with all the soft interface information * @backbone_gw: the backbone gateway for which a loop should be detected * * To detect loops that the bridge loop avoidance can't handle, send a loop * detection packet on the backbone. Unlike other BLA frames, this frame will * be allowed on the mesh by other nodes. If it is received on the mesh, this * indicates that there is a loop. */ static void batadv_bla_send_loopdetect(struct batadv_priv *bat_priv, struct batadv_bla_backbone_gw *backbone_gw) { batadv_dbg(BATADV_DBG_BLA, bat_priv, "Send loopdetect frame for vid %d\n", backbone_gw->vid); batadv_bla_send_claim(bat_priv, bat_priv->bla.loopdetect_addr, backbone_gw->vid, BATADV_CLAIM_TYPE_LOOPDETECT); } /** * batadv_bla_status_update() - purge bla interfaces if necessary * @net_dev: the soft interface net device */ void batadv_bla_status_update(struct net_device *net_dev) { struct batadv_priv *bat_priv = netdev_priv(net_dev); struct batadv_hard_iface *primary_if; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) return; /* this function already purges everything when bla is disabled, * so just call that one. */ batadv_bla_update_orig_address(bat_priv, primary_if, primary_if); batadv_hardif_put(primary_if); } /** * batadv_bla_periodic_work() - performs periodic bla work * @work: kernel work struct * * 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; struct batadv_priv *bat_priv; struct batadv_priv_bla *priv_bla; struct hlist_head *head; struct batadv_bla_backbone_gw *backbone_gw; struct batadv_hashtable *hash; struct batadv_hard_iface *primary_if; bool send_loopdetect = false; int i; delayed_work = to_delayed_work(work); priv_bla = container_of(delayed_work, struct batadv_priv_bla, work); bat_priv = container_of(priv_bla, struct batadv_priv, bla); 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; if (atomic_dec_and_test(&bat_priv->bla.loopdetect_next)) { /* set a new random mac address for the next bridge loop * detection frames. Set the locally administered bit to avoid * collisions with users mac addresses. */ eth_random_addr(bat_priv->bla.loopdetect_addr); bat_priv->bla.loopdetect_addr[0] = 0xba; bat_priv->bla.loopdetect_addr[1] = 0xbe; bat_priv->bla.loopdetect_lasttime = jiffies; atomic_set(&bat_priv->bla.loopdetect_next, BATADV_BLA_LOOPDETECT_PERIODS); /* mark for sending loop detect on all VLANs */ send_loopdetect = true; } hash = bat_priv->bla.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, 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); if (send_loopdetect) batadv_bla_send_loopdetect(bat_priv, backbone_gw); /* request_sent is only set after creation to avoid * problems when we are not yet known as backbone gw * in the backbone. * * We can reset this now after we waited some periods * to give bridge forward delays and bla group forming * some grace time. */ if (atomic_read(&backbone_gw->request_sent) == 0) continue; if (!atomic_dec_and_test(&backbone_gw->wait_periods)) continue; atomic_dec(&backbone_gw->bat_priv->bla.num_requests); atomic_set(&backbone_gw->request_sent, 0); } rcu_read_unlock(); } out: batadv_hardif_put(primary_if); queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work, msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH)); } /* 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; /** * batadv_bla_init() - initialize all bla structures * @bat_priv: the bat priv with all the soft interface information * * Return: 0 on success, < 0 on error. */ int batadv_bla_init(struct batadv_priv *bat_priv) { int i; u8 claim_dest[ETH_ALEN] = {0xff, 0x43, 0x05, 0x00, 0x00, 0x00}; struct batadv_hard_iface *primary_if; u16 crc; unsigned long entrytime; spin_lock_init(&bat_priv->bla.bcast_duplist_lock); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hash registering\n"); /* setting claim destination address */ memcpy(&bat_priv->bla.claim_dest.magic, claim_dest, 3); bat_priv->bla.claim_dest.type = 0; primary_if = batadv_primary_if_get_selected(bat_priv); if (primary_if) { crc = crc16(0, primary_if->net_dev->dev_addr, ETH_ALEN); bat_priv->bla.claim_dest.group = htons(crc); batadv_hardif_put(primary_if); } else { bat_priv->bla.claim_dest.group = 0; /* will be set later */ } /* initialize the duplicate list */ entrytime = jiffies - msecs_to_jiffies(BATADV_DUPLIST_TIMEOUT); for (i = 0; i < BATADV_DUPLIST_SIZE; i++) bat_priv->bla.bcast_duplist[i].entrytime = entrytime; bat_priv->bla.bcast_duplist_curr = 0; atomic_set(&bat_priv->bla.loopdetect_next, BATADV_BLA_LOOPDETECT_PERIODS); if (bat_priv->bla.claim_hash) return 0; bat_priv->bla.claim_hash = batadv_hash_new(128); if (!bat_priv->bla.claim_hash) return -ENOMEM; bat_priv->bla.backbone_hash = batadv_hash_new(32); if (!bat_priv->bla.backbone_hash) { batadv_hash_destroy(bat_priv->bla.claim_hash); return -ENOMEM; } batadv_hash_set_lock_class(bat_priv->bla.claim_hash, &batadv_claim_hash_lock_class_key); batadv_hash_set_lock_class(bat_priv->bla.backbone_hash, &batadv_backbone_hash_lock_class_key); batadv_dbg(BATADV_DBG_BLA, bat_priv, "bla hashes initialized\n"); 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)); return 0; } /** * batadv_bla_check_duplist() - Check if a frame is in the broadcast dup. * @bat_priv: the bat priv with all the soft interface information * @skb: contains the multicast packet to be checked * @payload_ptr: pointer to position inside the head buffer of the skb * marking the start of the data to be CRC'ed * @orig: originator mac address, NULL if unknown * * 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. * * Return: true if a packet is in the duplicate list, false otherwise. */ static bool batadv_bla_check_duplist(struct batadv_priv *bat_priv, struct sk_buff *skb, u8 *payload_ptr, const u8 *orig) { struct batadv_bcast_duplist_entry *entry; bool ret = false; int i, curr; __be32 crc; /* calculate the crc ... */ crc = batadv_skb_crc32(skb, payload_ptr); spin_lock_bh(&bat_priv->bla.bcast_duplist_lock); for (i = 0; i < BATADV_DUPLIST_SIZE; i++) { curr = (bat_priv->bla.bcast_duplist_curr + i); curr %= BATADV_DUPLIST_SIZE; entry = &bat_priv->bla.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; /* are the originators both known and not anonymous? */ if (orig && !is_zero_ether_addr(orig) && !is_zero_ether_addr(entry->orig)) { /* If known, check if the new frame came from * the same originator: * We are safe to take identical frames from the * same orig, if known, as multiplications in * the mesh are detected via the (orig, seqno) pair. * So we can be a bit more liberal here and allow * identical frames from the same orig which the source * host might have sent multiple times on purpose. */ if (batadv_compare_eth(entry->orig, orig)) continue; } /* this entry seems to match: same crc, not too old, * and from another gw. therefore return true to forbid it. */ ret = true; goto out; } /* not found, add a new entry (overwrite the oldest entry) * and allow it, its the first occurrence. */ curr = (bat_priv->bla.bcast_duplist_curr + BATADV_DUPLIST_SIZE - 1); curr %= BATADV_DUPLIST_SIZE; entry = &bat_priv->bla.bcast_duplist[curr]; entry->crc = crc; entry->entrytime = jiffies; /* known originator */ if (orig) ether_addr_copy(entry->orig, orig); /* anonymous originator */ else eth_zero_addr(entry->orig); bat_priv->bla.bcast_duplist_curr = curr; out: spin_unlock_bh(&bat_priv->bla.bcast_duplist_lock); return ret; } /** * batadv_bla_check_ucast_duplist() - Check if a frame is in the broadcast dup. * @bat_priv: the bat priv with all the soft interface information * @skb: contains the multicast packet to be checked, decapsulated from a * unicast_packet * * 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. * * Return: true if a packet is in the duplicate list, false otherwise. */ static bool batadv_bla_check_ucast_duplist(struct batadv_priv *bat_priv, struct sk_buff *skb) { return batadv_bla_check_duplist(bat_priv, skb, (u8 *)skb->data, NULL); } /** * batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup. * @bat_priv: the bat priv with all the soft interface information * @skb: contains the bcast_packet to be checked * * 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. * * Return: true if a packet is in the duplicate list, false otherwise. */ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv, struct sk_buff *skb) { struct batadv_bcast_packet *bcast_packet; u8 *payload_ptr; bcast_packet = (struct batadv_bcast_packet *)skb->data; payload_ptr = (u8 *)(bcast_packet + 1); return batadv_bla_check_duplist(bat_priv, skb, payload_ptr, bcast_packet->orig); } /** * batadv_bla_is_backbone_gw_orig() - Check if the originator is a gateway for * the VLAN identified by vid. * @bat_priv: the bat priv with all the soft interface information * @orig: originator mac address * @vid: VLAN identifier * * Return: true if orig is a backbone for this vid, false otherwise. */ bool batadv_bla_is_backbone_gw_orig(struct batadv_priv *bat_priv, u8 *orig, unsigned short vid) { struct batadv_hashtable *hash = bat_priv->bla.backbone_hash; struct hlist_head *head; struct batadv_bla_backbone_gw *backbone_gw; int i; if (!atomic_read(&bat_priv->bridge_loop_avoidance)) return false; if (!hash) return false; for (i = 0; i < hash->size; i++) { head = &hash->table[i]; rcu_read_lock(); hlist_for_each_entry_rcu(backbone_gw, head, hash_entry) { if (batadv_compare_eth(backbone_gw->orig, orig) && backbone_gw->vid == vid) { rcu_read_unlock(); return true; } } rcu_read_unlock(); } return false; } /** * batadv_bla_is_backbone_gw() - check if originator is a backbone gw for a VLAN * @skb: the frame to be checked * @orig_node: the orig_node of the frame * @hdr_size: maximum length of the frame * * Return: true if the orig_node is also a gateway on the soft interface, * otherwise it returns false. */ bool batadv_bla_is_backbone_gw(struct sk_buff *skb, struct batadv_orig_node *orig_node, int hdr_size) { struct batadv_bla_backbone_gw *backbone_gw; unsigned short vid; if (!atomic_read(&orig_node->bat_priv->bridge_loop_avoidance)) return false; /* first, find out the vid. */ if (!pskb_may_pull(skb, hdr_size + ETH_HLEN)) return false; vid = batadv_get_vid(skb, hdr_size); /* 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 false; batadv_backbone_gw_put(backbone_gw); return true; } /** * batadv_bla_free() - free all bla structures * @bat_priv: the bat priv with all the soft interface information * * 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->bla.claim_hash) { batadv_bla_purge_claims(bat_priv, primary_if, 1); batadv_hash_destroy(bat_priv->bla.claim_hash); bat_priv->bla.claim_hash = NULL; } if (bat_priv->bla.backbone_hash) { batadv_bla_purge_backbone_gw(bat_priv, 1); batadv_hash_destroy(bat_priv->bla.backbone_hash); bat_priv->bla.backbone_hash = NULL; } batadv_hardif_put(primary_if); } /** * batadv_bla_loopdetect_check() - check and handle a detected loop * @bat_priv: the bat priv with all the soft interface information * @skb: the packet to check * @primary_if: interface where the request came on * @vid: the VLAN ID of the frame * * Checks if this packet is a loop detect frame which has been sent by us, * throws an uevent and logs the event if that is the case. * * Return: true if it is a loop detect frame which is to be dropped, false * otherwise. */ static bool batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, struct batadv_hard_iface *primary_if, unsigned short vid) { struct batadv_bla_backbone_gw *backbone_gw; struct ethhdr *ethhdr; bool ret; ethhdr = eth_hdr(skb); /* Only check for the MAC address and skip more checks here for * performance reasons - this function is on the hotpath, after all. */ if (!batadv_compare_eth(ethhdr->h_source, bat_priv->bla.loopdetect_addr)) return false; /* If the packet came too late, don't forward it on the mesh * but don't consider that as loop. It might be a coincidence. */ if (batadv_has_timed_out(bat_priv->bla.loopdetect_lasttime, BATADV_BLA_LOOPDETECT_TIMEOUT)) return true; backbone_gw = batadv_bla_get_backbone_gw(bat_priv, primary_if->net_dev->dev_addr, vid, true); if (unlikely(!backbone_gw)) return true; ret = queue_work(batadv_event_workqueue, &backbone_gw->report_work); /* backbone_gw is unreferenced in the report work function * if queue_work() call was successful */ if (!ret) batadv_backbone_gw_put(backbone_gw); return true; } /** * batadv_bla_rx() - check packets coming from the mesh. * @bat_priv: the bat priv with all the soft interface information * @skb: the frame to be checked * @vid: the VLAN ID of the frame * @packet_type: the batman packet type this frame came in * * batadv_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 * * Return: true if handled, otherwise it returns false and the caller shall * further process the skb. */ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid, int packet_type) { struct batadv_bla_backbone_gw *backbone_gw; struct ethhdr *ethhdr; struct batadv_bla_claim search_claim, *claim = NULL; struct batadv_hard_iface *primary_if; bool own_claim; bool ret; ethhdr = eth_hdr(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 (batadv_bla_loopdetect_check(bat_priv, skb, primary_if, vid)) goto handled; if (unlikely(atomic_read(&bat_priv->bla.num_requests))) /* don't allow multicast packets while requests are in flight */ if (is_multicast_ether_addr(ethhdr->h_dest)) /* Both broadcast flooding or multicast-via-unicasts * delivery might send to multiple backbone gateways * sharing the same LAN and therefore need to coordinate * which backbone gateway forwards into the LAN, * by claiming the payload source address. * * Broadcast flooding and multicast-via-unicasts * delivery use the following two batman packet types. * Note: explicitly exclude BATADV_UNICAST_4ADDR, * as the DHCP gateway feature will send explicitly * to only one BLA gateway, so the claiming process * should be avoided there. */ if (packet_type == BATADV_BCAST || packet_type == BATADV_UNICAST) goto handled; /* potential duplicates from foreign BLA backbone gateways via * multicast-in-unicast packets */ if (is_multicast_ether_addr(ethhdr->h_dest) && packet_type == BATADV_UNICAST && batadv_bla_check_ucast_duplist(bat_priv, skb)) goto handled; ether_addr_copy(search_claim.addr, ethhdr->h_source); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim); if (!claim) { bool local = batadv_is_my_client(bat_priv, ethhdr->h_source, vid); /* possible optimization: race for a claim */ /* No claim exists yet, claim it for us! */ batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): Unclaimed MAC %pM found. Claim it. Local: %s\n", __func__, ethhdr->h_source, str_yes_no(local)); 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 ... */ backbone_gw = batadv_bla_claim_get_backbone_gw(claim); own_claim = batadv_compare_eth(backbone_gw->orig, primary_if->net_dev->dev_addr); batadv_backbone_gw_put(backbone_gw); if (own_claim) { /* ... allow it in any case */ claim->lasttime = jiffies; goto allow; } /* if it is a multicast ... */ if (is_multicast_ether_addr(ethhdr->h_dest) && (packet_type == BATADV_BCAST || packet_type == BATADV_UNICAST)) { /* ... drop it. the responsible gateway is in charge. * * We need to check packet type because with the gateway * feature, broadcasts (like DHCP requests) may be sent * using a unicast 4 address packet type. See comment above. */ 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 = false; goto out; handled: kfree_skb(skb); ret = true; out: batadv_hardif_put(primary_if); batadv_claim_put(claim); return ret; } /** * batadv_bla_tx() - check packets going into the mesh * @bat_priv: the bat priv with all the soft interface information * @skb: the frame to be checked * @vid: the VLAN ID of the frame * * batadv_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. * * This call might reallocate skb data. * * Return: true if handled, otherwise it returns false and the caller shall * further process the skb. */ bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb, unsigned short vid) { struct ethhdr *ethhdr; struct batadv_bla_claim search_claim, *claim = NULL; struct batadv_bla_backbone_gw *backbone_gw; struct batadv_hard_iface *primary_if; bool client_roamed; bool ret = false; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto out; if (!atomic_read(&bat_priv->bridge_loop_avoidance)) goto allow; if (batadv_bla_process_claim(bat_priv, primary_if, skb)) goto handled; ethhdr = eth_hdr(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; ether_addr_copy(search_claim.addr, ethhdr->h_source); 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. */ backbone_gw = batadv_bla_claim_get_backbone_gw(claim); client_roamed = batadv_compare_eth(backbone_gw->orig, primary_if->net_dev->dev_addr); batadv_backbone_gw_put(backbone_gw); if (client_roamed) { /* if yes, the client has roamed and we have * to unclaim it. */ if (batadv_has_timed_out(claim->lasttime, 100)) { /* only unclaim if the last claim entry is * older than 100 ms to make sure we really * have a roaming client here. */ batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): Roaming client %pM detected. Unclaim it.\n", __func__, ethhdr->h_source); batadv_handle_unclaim(bat_priv, primary_if, primary_if->net_dev->dev_addr, ethhdr->h_source, vid); goto allow; } else { batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): Race for claim %pM detected. Drop packet.\n", __func__, ethhdr->h_source); goto handled; } } /* 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 = false; goto out; handled: ret = true; out: batadv_hardif_put(primary_if); batadv_claim_put(claim); return ret; } /** * batadv_bla_claim_dump_entry() - dump one entry of the claim table * to a netlink socket * @msg: buffer for the message * @portid: netlink port * @cb: Control block containing additional options * @primary_if: primary interface * @claim: entry to dump * * Return: 0 or error code. */ static int batadv_bla_claim_dump_entry(struct sk_buff *msg, u32 portid, struct netlink_callback *cb, struct batadv_hard_iface *primary_if, struct batadv_bla_claim *claim) { const u8 *primary_addr = primary_if->net_dev->dev_addr; u16 backbone_crc; bool is_own; void *hdr; int ret = -EINVAL; hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq, &batadv_netlink_family, NLM_F_MULTI, BATADV_CMD_GET_BLA_CLAIM); if (!hdr) { ret = -ENOBUFS; goto out; } genl_dump_check_consistent(cb, hdr); is_own = batadv_compare_eth(claim->backbone_gw->orig, primary_addr); spin_lock_bh(&claim->backbone_gw->crc_lock); backbone_crc = claim->backbone_gw->crc; spin_unlock_bh(&claim->backbone_gw->crc_lock); if (is_own) if (nla_put_flag(msg, BATADV_ATTR_BLA_OWN)) { genlmsg_cancel(msg, hdr); goto out; } if (nla_put(msg, BATADV_ATTR_BLA_ADDRESS, ETH_ALEN, claim->addr) || nla_put_u16(msg, BATADV_ATTR_BLA_VID, claim->vid) || nla_put(msg, BATADV_ATTR_BLA_BACKBONE, ETH_ALEN, claim->backbone_gw->orig) || nla_put_u16(msg, BATADV_ATTR_BLA_CRC, backbone_crc)) { genlmsg_cancel(msg, hdr); goto out; } genlmsg_end(msg, hdr); ret = 0; out: return ret; } /** * batadv_bla_claim_dump_bucket() - dump one bucket of the claim table * to a netlink socket * @msg: buffer for the message * @portid: netlink port * @cb: Control block containing additional options * @primary_if: primary interface * @hash: hash to dump * @bucket: bucket index to dump * @idx_skip: How many entries to skip * * Return: always 0. */ static int batadv_bla_claim_dump_bucket(struct sk_buff *msg, u32 portid, struct netlink_callback *cb, struct batadv_hard_iface *primary_if, struct batadv_hashtable *hash, unsigned int bucket, int *idx_skip) { struct batadv_bla_claim *claim; int idx = 0; int ret = 0; spin_lock_bh(&hash->list_locks[bucket]); cb->seq = atomic_read(&hash->generation) << 1 | 1; hlist_for_each_entry(claim, &hash->table[bucket], hash_entry) { if (idx++ < *idx_skip) continue; ret = batadv_bla_claim_dump_entry(msg, portid, cb, primary_if, claim); if (ret) { *idx_skip = idx - 1; goto unlock; } } *idx_skip = 0; unlock: spin_unlock_bh(&hash->list_locks[bucket]); return ret; } /** * batadv_bla_claim_dump() - dump claim table to a netlink socket * @msg: buffer for the message * @cb: callback structure containing arguments * * Return: message length. */ int batadv_bla_claim_dump(struct sk_buff *msg, struct netlink_callback *cb) { struct batadv_hard_iface *primary_if = NULL; int portid = NETLINK_CB(cb->skb).portid; struct net *net = sock_net(cb->skb->sk); struct net_device *soft_iface; struct batadv_hashtable *hash; struct batadv_priv *bat_priv; int bucket = cb->args[0]; int idx = cb->args[1]; int ifindex; int ret = 0; ifindex = batadv_netlink_get_ifindex(cb->nlh, BATADV_ATTR_MESH_IFINDEX); if (!ifindex) return -EINVAL; soft_iface = dev_get_by_index(net, ifindex); if (!soft_iface || !batadv_softif_is_valid(soft_iface)) { ret = -ENODEV; goto out; } bat_priv = netdev_priv(soft_iface); hash = bat_priv->bla.claim_hash; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) { ret = -ENOENT; goto out; } while (bucket < hash->size) { if (batadv_bla_claim_dump_bucket(msg, portid, cb, primary_if, hash, bucket, &idx)) break; bucket++; } cb->args[0] = bucket; cb->args[1] = idx; ret = msg->len; out: batadv_hardif_put(primary_if); dev_put(soft_iface); return ret; } /** * batadv_bla_backbone_dump_entry() - dump one entry of the backbone table to a * netlink socket * @msg: buffer for the message * @portid: netlink port * @cb: Control block containing additional options * @primary_if: primary interface * @backbone_gw: entry to dump * * Return: 0 or error code. */ static int batadv_bla_backbone_dump_entry(struct sk_buff *msg, u32 portid, struct netlink_callback *cb, struct batadv_hard_iface *primary_if, struct batadv_bla_backbone_gw *backbone_gw) { const u8 *primary_addr = primary_if->net_dev->dev_addr; u16 backbone_crc; bool is_own; int msecs; void *hdr; int ret = -EINVAL; hdr = genlmsg_put(msg, portid, cb->nlh->nlmsg_seq, &batadv_netlink_family, NLM_F_MULTI, BATADV_CMD_GET_BLA_BACKBONE); if (!hdr) { ret = -ENOBUFS; goto out; } genl_dump_check_consistent(cb, hdr); is_own = batadv_compare_eth(backbone_gw->orig, primary_addr); spin_lock_bh(&backbone_gw->crc_lock); backbone_crc = backbone_gw->crc; spin_unlock_bh(&backbone_gw->crc_lock); msecs = jiffies_to_msecs(jiffies - backbone_gw->lasttime); if (is_own) if (nla_put_flag(msg, BATADV_ATTR_BLA_OWN)) { genlmsg_cancel(msg, hdr); goto out; } if (nla_put(msg, BATADV_ATTR_BLA_BACKBONE, ETH_ALEN, backbone_gw->orig) || nla_put_u16(msg, BATADV_ATTR_BLA_VID, backbone_gw->vid) || nla_put_u16(msg, BATADV_ATTR_BLA_CRC, backbone_crc) || nla_put_u32(msg, BATADV_ATTR_LAST_SEEN_MSECS, msecs)) { genlmsg_cancel(msg, hdr); goto out; } genlmsg_end(msg, hdr); ret = 0; out: return ret; } /** * batadv_bla_backbone_dump_bucket() - dump one bucket of the backbone table to * a netlink socket * @msg: buffer for the message * @portid: netlink port * @cb: Control block containing additional options * @primary_if: primary interface * @hash: hash to dump * @bucket: bucket index to dump * @idx_skip: How many entries to skip * * Return: always 0. */ static int batadv_bla_backbone_dump_bucket(struct sk_buff *msg, u32 portid, struct netlink_callback *cb, struct batadv_hard_iface *primary_if, struct batadv_hashtable *hash, unsigned int bucket, int *idx_skip) { struct batadv_bla_backbone_gw *backbone_gw; int idx = 0; int ret = 0; spin_lock_bh(&hash->list_locks[bucket]); cb->seq = atomic_read(&hash->generation) << 1 | 1; hlist_for_each_entry(backbone_gw, &hash->table[bucket], hash_entry) { if (idx++ < *idx_skip) continue; ret = batadv_bla_backbone_dump_entry(msg, portid, cb, primary_if, backbone_gw); if (ret) { *idx_skip = idx - 1; goto unlock; } } *idx_skip = 0; unlock: spin_unlock_bh(&hash->list_locks[bucket]); return ret; } /** * batadv_bla_backbone_dump() - dump backbone table to a netlink socket * @msg: buffer for the message * @cb: callback structure containing arguments * * Return: message length. */ int batadv_bla_backbone_dump(struct sk_buff *msg, struct netlink_callback *cb) { struct batadv_hard_iface *primary_if = NULL; int portid = NETLINK_CB(cb->skb).portid; struct net *net = sock_net(cb->skb->sk); struct net_device *soft_iface; struct batadv_hashtable *hash; struct batadv_priv *bat_priv; int bucket = cb->args[0]; int idx = cb->args[1]; int ifindex; int ret = 0; ifindex = batadv_netlink_get_ifindex(cb->nlh, BATADV_ATTR_MESH_IFINDEX); if (!ifindex) return -EINVAL; soft_iface = dev_get_by_index(net, ifindex); if (!soft_iface || !batadv_softif_is_valid(soft_iface)) { ret = -ENODEV; goto out; } bat_priv = netdev_priv(soft_iface); hash = bat_priv->bla.backbone_hash; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if || primary_if->if_status != BATADV_IF_ACTIVE) { ret = -ENOENT; goto out; } while (bucket < hash->size) { if (batadv_bla_backbone_dump_bucket(msg, portid, cb, primary_if, hash, bucket, &idx)) break; bucket++; } cb->args[0] = bucket; cb->args[1] = idx; ret = msg->len; out: batadv_hardif_put(primary_if); dev_put(soft_iface); return ret; } #ifdef CONFIG_BATMAN_ADV_DAT /** * batadv_bla_check_claim() - check if address is claimed * * @bat_priv: the bat priv with all the soft interface information * @addr: mac address of which the claim status is checked * @vid: the VLAN ID * * addr is checked if this address is claimed by the local device itself. * * Return: true if bla is disabled or the mac is claimed by the device, * false if the device addr is already claimed by another gateway */ bool batadv_bla_check_claim(struct batadv_priv *bat_priv, u8 *addr, unsigned short vid) { struct batadv_bla_claim search_claim; struct batadv_bla_claim *claim = NULL; struct batadv_hard_iface *primary_if = NULL; bool ret = true; if (!atomic_read(&bat_priv->bridge_loop_avoidance)) return ret; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) return ret; /* First look if the mac address is claimed */ ether_addr_copy(search_claim.addr, addr); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim); /* If there is a claim and we are not owner of the claim, * return false. */ if (claim) { if (!batadv_compare_eth(claim->backbone_gw->orig, primary_if->net_dev->dev_addr)) ret = false; batadv_claim_put(claim); } batadv_hardif_put(primary_if); return ret; } #endif