/* 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; int i; delayed_work = container_of(work, struct 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; 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); /* 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: if (primary_if) batadv_hardif_free_ref(primary_if); queue_delayed_work(batadv_event_workqueue, &bat_priv->bla.work, msecs_to_jiffies(BATADV_BLA_PERIOD_LENGTH)); }
/** * batadv_check_claim_group * @bat_priv: the bat priv with all the soft interface information * @hw_src: the Hardware source in the ARP Header * @hw_dst: the Hardware destination in the ARP Header * @ethhdr: pointer to the Ethernet header of the claim frame * * checks if it is a claim packet and if its on the same group. * This function also applies the group ID of the sender * if it is in the same mesh. * * returns: * 2 - if it is a claim packet and on the same group * 1 - if is a claim packet from another group * 0 - if it is not a claim packet */ static int batadv_check_claim_group(struct batadv_priv *bat_priv, struct batadv_hard_iface *primary_if, uint8_t *hw_src, uint8_t *hw_dst, struct ethhdr *ethhdr) { uint8_t *backbone_addr; struct batadv_orig_node *orig_node; struct batadv_bla_claim_dst *bla_dst, *bla_dst_own; bla_dst = (struct batadv_bla_claim_dst *)hw_dst; bla_dst_own = &bat_priv->bla.claim_dest; /* check if it is a claim packet in general */ if (memcmp(bla_dst->magic, bla_dst_own->magic, sizeof(bla_dst->magic)) != 0) return 0; /* if announcement packet, use the source, * otherwise assume it is in the hw_src */ switch (bla_dst->type) { case BATADV_CLAIM_TYPE_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); /* dont accept claims from gateways which are not in * the same mesh or group. */ if (!orig_node) return 1; /* if our mesh friends mac is bigger, use it for ourselves. */ if (ntohs(bla_dst->group) > ntohs(bla_dst_own->group)) { batadv_dbg(BATADV_DBG_BLA, bat_priv, "taking other backbones claim group: %#.4x\n", ntohs(bla_dst->group)); bla_dst_own->group = bla_dst->group; } batadv_orig_node_free_ref(orig_node); return 2; }
/** * batadv_bla_rx * @bat_priv: the bat priv with all the soft interface information * @skb: the frame to be checked * @vid: the VLAN ID of the frame * @is_bcast: the packet came in a broadcast packet type. * * bla_rx avoidance checks if: * * we have to race for a claim * * if the frame is allowed on the LAN * * in these cases, the skb is further handled by this function and * returns 1, otherwise it returns 0 and the caller shall further * process the skb. */ int batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, short vid, bool is_bcast) { struct ethhdr *ethhdr; struct batadv_bla_claim search_claim, *claim = NULL; struct batadv_hard_iface *primary_if; int ret; ethhdr = (struct ethhdr *)skb_mac_header(skb); primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto handled; if (!atomic_read(&bat_priv->bridge_loop_avoidance)) goto allow; if (unlikely(atomic_read(&bat_priv->bla.num_requests))) /* don't allow broadcasts while requests are in flight */ if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) goto handled; memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim); if (!claim) { /* possible optimization: race for a claim */ /* No claim exists yet, claim it for us! */ batadv_handle_claim(bat_priv, primary_if, primary_if->net_dev->dev_addr, ethhdr->h_source, vid); goto allow; } /* if it is our own claim ... */ if (batadv_compare_eth(claim->backbone_gw->orig, primary_if->net_dev->dev_addr)) { /* ... allow it in any case */ claim->lasttime = jiffies; goto allow; } /* if it is a broadcast ... */ if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) { /* ... drop it. the responsible gateway is in charge. * * We need to check is_bcast because with the gateway * feature, broadcasts (like DHCP requests) may be sent * using a unicast packet type. */ goto handled; } else { /* seems the client considers us as its best gateway. * send a claim and update the claim table * immediately. */ batadv_handle_claim(bat_priv, primary_if, primary_if->net_dev->dev_addr, ethhdr->h_source, vid); goto allow; } allow: batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); ret = 0; goto out; handled: kfree_skb(skb); ret = 1; out: if (primary_if) batadv_hardif_free_ref(primary_if); if (claim) batadv_claim_free_ref(claim); return ret; }
/** * batadv_bla_tx * @bat_priv: the bat priv with all the soft interface information * @skb: the frame to be checked * @vid: the VLAN ID of the frame * * bla_tx checks if: * * a claim was received which has to be processed * * the frame is allowed on the mesh * * in these cases, the skb is further handled by this function and * returns 1, otherwise it returns 0 and the caller shall further * process the skb. */ int batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb, short vid) { struct ethhdr *ethhdr; struct batadv_bla_claim search_claim, *claim = NULL; struct batadv_hard_iface *primary_if; int ret = 0; primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto out; if (!atomic_read(&bat_priv->bridge_loop_avoidance)) goto allow; /* in VLAN case, the mac header might not be set. */ skb_reset_mac_header(skb); if (batadv_bla_process_claim(bat_priv, primary_if, skb)) goto handled; ethhdr = (struct ethhdr *)skb_mac_header(skb); if (unlikely(atomic_read(&bat_priv->bla.num_requests))) /* don't allow broadcasts while requests are in flight */ if (is_multicast_ether_addr(ethhdr->h_dest)) goto handled; memcpy(search_claim.addr, ethhdr->h_source, ETH_ALEN); search_claim.vid = vid; claim = batadv_claim_hash_find(bat_priv, &search_claim); /* if no claim exists, allow it. */ if (!claim) goto allow; /* check if we are responsible. */ if (batadv_compare_eth(claim->backbone_gw->orig, primary_if->net_dev->dev_addr)) { /* if yes, the client has roamed and we have * to unclaim it. */ batadv_handle_unclaim(bat_priv, primary_if, primary_if->net_dev->dev_addr, ethhdr->h_source, vid); goto allow; } /* check if it is a multicast/broadcast frame */ if (is_multicast_ether_addr(ethhdr->h_dest)) { /* drop it. the responsible gateway has forwarded it into * the backbone network. */ goto handled; } else { /* we must allow it. at least if we are * responsible for the DESTINATION. */ goto allow; } allow: batadv_bla_update_own_backbone_gw(bat_priv, primary_if, vid); ret = 0; goto out; handled: ret = 1; out: if (primary_if) batadv_hardif_free_ref(primary_if); if (claim) batadv_claim_free_ref(claim); return ret; }
static int batadv_interface_tx(struct sk_buff *skb, struct net_device *soft_iface) { struct ethhdr *ethhdr = (struct ethhdr *)skb->data; struct batadv_priv *bat_priv = netdev_priv(soft_iface); struct batadv_hard_iface *primary_if = NULL; struct batadv_bcast_packet *bcast_packet; struct vlan_ethhdr *vhdr; __be16 ethertype = __constant_htons(ETH_P_BATMAN); static const uint8_t stp_addr[ETH_ALEN] = {0x01, 0x80, 0xC2, 0x00, 0x00, 0x00}; static const uint8_t ectp_addr[ETH_ALEN] = {0xCF, 0x00, 0x00, 0x00, 0x00, 0x00}; unsigned int header_len = 0; int data_len = skb->len, ret; short vid __maybe_unused = -1; bool do_bcast = false; uint32_t seqno; unsigned long brd_delay = 1; if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) goto dropped; soft_iface->trans_start = jiffies; switch (ntohs(ethhdr->h_proto)) { case ETH_P_8021Q: vhdr = (struct vlan_ethhdr *)skb->data; vid = ntohs(vhdr->h_vlan_TCI) & VLAN_VID_MASK; if (vhdr->h_vlan_encapsulated_proto != ethertype) break; /* fall through */ case ETH_P_BATMAN: goto dropped; } if (batadv_bla_tx(bat_priv, skb, vid)) goto dropped; /* Register the client MAC in the transtable */ if (!is_multicast_ether_addr(ethhdr->h_source)) batadv_tt_local_add(soft_iface, ethhdr->h_source, skb->skb_iif); /* don't accept stp packets. STP does not help in meshes. * better use the bridge loop avoidance ... * * The same goes for ECTP sent at least by some Cisco Switches, * it might confuse the mesh when used with bridge loop avoidance. */ if (batadv_compare_eth(ethhdr->h_dest, stp_addr)) goto dropped; if (batadv_compare_eth(ethhdr->h_dest, ectp_addr)) goto dropped; if (is_multicast_ether_addr(ethhdr->h_dest)) { do_bcast = true; switch (atomic_read(&bat_priv->gw_mode)) { case BATADV_GW_MODE_SERVER: /* gateway servers should not send dhcp * requests into the mesh */ ret = batadv_gw_is_dhcp_target(skb, &header_len); if (ret) goto dropped; break; case BATADV_GW_MODE_CLIENT: /* gateway clients should send dhcp requests * via unicast to their gateway */ ret = batadv_gw_is_dhcp_target(skb, &header_len); if (ret) do_bcast = false; break; case BATADV_GW_MODE_OFF: default: break; } } /* ethernet packet should be broadcasted */ if (do_bcast) { primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto dropped; /* in case of ARP request, we do not immediately broadcasti the * packet, instead we first wait for DAT to try to retrieve the * correct ARP entry */ if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb)) brd_delay = msecs_to_jiffies(ARP_REQ_DELAY); if (batadv_skb_head_push(skb, sizeof(*bcast_packet)) < 0) goto dropped; bcast_packet = (struct batadv_bcast_packet *)skb->data; bcast_packet->header.version = BATADV_COMPAT_VERSION; bcast_packet->header.ttl = BATADV_TTL; /* batman packet type: broadcast */ bcast_packet->header.packet_type = BATADV_BCAST; bcast_packet->reserved = 0; /* hw address of first interface is the orig mac because only * this mac is known throughout the mesh */ memcpy(bcast_packet->orig, primary_if->net_dev->dev_addr, ETH_ALEN); /* set broadcast sequence number */ seqno = atomic_inc_return(&bat_priv->bcast_seqno); bcast_packet->seqno = htonl(seqno); batadv_add_bcast_packet_to_list(bat_priv, skb, brd_delay); /* a copy is stored in the bcast list, therefore removing * the original skb. */ kfree_skb(skb); /* unicast packet */ } else { if (atomic_read(&bat_priv->gw_mode) != BATADV_GW_MODE_OFF) { ret = batadv_gw_out_of_range(bat_priv, skb, ethhdr); if (ret) goto dropped; } if (batadv_dat_snoop_outgoing_arp_request(bat_priv, skb)) goto dropped; batadv_dat_snoop_outgoing_arp_reply(bat_priv, skb); ret = batadv_unicast_send_skb(bat_priv, skb); if (ret != 0) goto dropped_freed; } batadv_inc_counter(bat_priv, BATADV_CNT_TX); batadv_add_counter(bat_priv, BATADV_CNT_TX_BYTES, data_len); goto end; dropped: kfree_skb(skb); dropped_freed: batadv_inc_counter(bat_priv, BATADV_CNT_TX_DROPPED); end: if (primary_if) batadv_hardif_free_ref(primary_if); return NETDEV_TX_OK; }