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Diffstat (limited to '')
| -rw-r--r-- | net/batman-adv/bridge_loop_avoidance.c | 2502 |
1 files changed, 2502 insertions, 0 deletions
diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c new file mode 100644 index 000000000..37ce6cfb3 --- /dev/null +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -0,0 +1,2502 @@ +// 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 <linux/atomic.h> +#include <linux/byteorder/generic.h> +#include <linux/compiler.h> +#include <linux/container_of.h> +#include <linux/crc16.h> +#include <linux/errno.h> +#include <linux/etherdevice.h> +#include <linux/gfp.h> +#include <linux/if_arp.h> +#include <linux/if_ether.h> +#include <linux/if_vlan.h> +#include <linux/jhash.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/kref.h> +#include <linux/list.h> +#include <linux/lockdep.h> +#include <linux/netdevice.h> +#include <linux/netlink.h> +#include <linux/rculist.h> +#include <linux/rcupdate.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/stddef.h> +#include <linux/string.h> +#include <linux/workqueue.h> +#include <net/arp.h> +#include <net/genetlink.h> +#include <net/netlink.h> +#include <net/sock.h> +#include <uapi/linux/batadv_packet.h> +#include <uapi/linux/batman_adv.h> + +#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) { + /* 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, + batadv_is_my_client(bat_priv, + ethhdr->h_source, vid) ? + "yes" : "no"); + 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 |