// SPDX-License-Identifier: GPL-2.0 /* Copyright (C) 2007-2019 B.A.T.M.A.N. contributors: * * Marek Lindner, Simon Wunderlich */ #include "routing.h" #include "main.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "bitarray.h" #include "bridge_loop_avoidance.h" #include "distributed-arp-table.h" #include "fragmentation.h" #include "hard-interface.h" #include "icmp_socket.h" #include "log.h" #include "network-coding.h" #include "originator.h" #include "send.h" #include "soft-interface.h" #include "tp_meter.h" #include "translation-table.h" #include "tvlv.h" static int batadv_route_unicast_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if); /** * _batadv_update_route() - set the router for this originator * @bat_priv: the bat priv with all the soft interface information * @orig_node: orig node which is to be configured * @recv_if: the receive interface for which this route is set * @neigh_node: neighbor which should be the next router * * This function does not perform any error checks */ static void _batadv_update_route(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node, struct batadv_hard_iface *recv_if, struct batadv_neigh_node *neigh_node) { struct batadv_orig_ifinfo *orig_ifinfo; struct batadv_neigh_node *curr_router; orig_ifinfo = batadv_orig_ifinfo_get(orig_node, recv_if); if (!orig_ifinfo) return; spin_lock_bh(&orig_node->neigh_list_lock); /* curr_router used earlier may not be the current orig_ifinfo->router * anymore because it was dereferenced outside of the neigh_list_lock * protected region. After the new best neighbor has replace the current * best neighbor the reference counter needs to decrease. Consequently, * the code needs to ensure the curr_router variable contains a pointer * to the replaced best neighbor. */ curr_router = rcu_dereference_protected(orig_ifinfo->router, true); /* increase refcount of new best neighbor */ if (neigh_node) kref_get(&neigh_node->refcount); rcu_assign_pointer(orig_ifinfo->router, neigh_node); spin_unlock_bh(&orig_node->neigh_list_lock); batadv_orig_ifinfo_put(orig_ifinfo); /* route deleted */ if (curr_router && !neigh_node) { batadv_dbg(BATADV_DBG_ROUTES, bat_priv, "Deleting route towards: %pM\n", orig_node->orig); batadv_tt_global_del_orig(bat_priv, orig_node, -1, "Deleted route towards originator"); /* route added */ } else if (!curr_router && neigh_node) { batadv_dbg(BATADV_DBG_ROUTES, bat_priv, "Adding route towards: %pM (via %pM)\n", orig_node->orig, neigh_node->addr); /* route changed */ } else if (neigh_node && curr_router) { batadv_dbg(BATADV_DBG_ROUTES, bat_priv, "Changing route towards: %pM (now via %pM - was via %pM)\n", orig_node->orig, neigh_node->addr, curr_router->addr); } /* decrease refcount of previous best neighbor */ if (curr_router) batadv_neigh_node_put(curr_router); } /** * batadv_update_route() - set the router for this originator * @bat_priv: the bat priv with all the soft interface information * @orig_node: orig node which is to be configured * @recv_if: the receive interface for which this route is set * @neigh_node: neighbor which should be the next router */ void batadv_update_route(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node, struct batadv_hard_iface *recv_if, struct batadv_neigh_node *neigh_node) { struct batadv_neigh_node *router = NULL; if (!orig_node) goto out; router = batadv_orig_router_get(orig_node, recv_if); if (router != neigh_node) _batadv_update_route(bat_priv, orig_node, recv_if, neigh_node); out: if (router) batadv_neigh_node_put(router); } /** * batadv_window_protected() - checks whether the host restarted and is in the * protection time. * @bat_priv: the bat priv with all the soft interface information * @seq_num_diff: difference between the current/received sequence number and * the last sequence number * @seq_old_max_diff: maximum age of sequence number not considered as restart * @last_reset: jiffies timestamp of the last reset, will be updated when reset * is detected * @protection_started: is set to true if the protection window was started, * doesn't change otherwise. * * Return: * false if the packet is to be accepted. * true if the packet is to be ignored. */ bool batadv_window_protected(struct batadv_priv *bat_priv, s32 seq_num_diff, s32 seq_old_max_diff, unsigned long *last_reset, bool *protection_started) { if (seq_num_diff <= -seq_old_max_diff || seq_num_diff >= BATADV_EXPECTED_SEQNO_RANGE) { if (!batadv_has_timed_out(*last_reset, BATADV_RESET_PROTECTION_MS)) return true; *last_reset = jiffies; if (protection_started) *protection_started = true; batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "old packet received, start protection\n"); } return false; } /** * batadv_check_management_packet() - Check preconditions for management packets * @skb: incoming packet buffer * @hard_iface: incoming hard interface * @header_len: minimal header length of packet type * * Return: true when management preconditions are met, false otherwise */ bool batadv_check_management_packet(struct sk_buff *skb, struct batadv_hard_iface *hard_iface, int header_len) { struct ethhdr *ethhdr; /* drop packet if it has not necessary minimum size */ if (unlikely(!pskb_may_pull(skb, header_len))) return false; ethhdr = eth_hdr(skb); /* packet with broadcast indication but unicast recipient */ if (!is_broadcast_ether_addr(ethhdr->h_dest)) return false; /* packet with invalid sender address */ if (!is_valid_ether_addr(ethhdr->h_source)) return false; /* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, 0) < 0) return false; /* keep skb linear */ if (skb_linearize(skb) < 0) return false; return true; } /** * batadv_recv_my_icmp_packet() - receive an icmp packet locally * @bat_priv: the bat priv with all the soft interface information * @skb: icmp packet to process * * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP * otherwise. */ static int batadv_recv_my_icmp_packet(struct batadv_priv *bat_priv, struct sk_buff *skb) { struct batadv_hard_iface *primary_if = NULL; struct batadv_orig_node *orig_node = NULL; struct batadv_icmp_header *icmph; int res, ret = NET_RX_DROP; icmph = (struct batadv_icmp_header *)skb->data; switch (icmph->msg_type) { case BATADV_ECHO_REPLY: case BATADV_DESTINATION_UNREACHABLE: case BATADV_TTL_EXCEEDED: /* receive the packet */ if (skb_linearize(skb) < 0) break; batadv_socket_receive_packet(icmph, skb->len); break; case BATADV_ECHO_REQUEST: /* answer echo request (ping) */ primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto out; /* get routing information */ orig_node = batadv_orig_hash_find(bat_priv, icmph->orig); if (!orig_node) goto out; /* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, ETH_HLEN) < 0) goto out; icmph = (struct batadv_icmp_header *)skb->data; ether_addr_copy(icmph->dst, icmph->orig); ether_addr_copy(icmph->orig, primary_if->net_dev->dev_addr); icmph->msg_type = BATADV_ECHO_REPLY; icmph->ttl = BATADV_TTL; res = batadv_send_skb_to_orig(skb, orig_node, NULL); if (res == NET_XMIT_SUCCESS) ret = NET_RX_SUCCESS; /* skb was consumed */ skb = NULL; break; case BATADV_TP: if (!pskb_may_pull(skb, sizeof(struct batadv_icmp_tp_packet))) goto out; batadv_tp_meter_recv(bat_priv, skb); ret = NET_RX_SUCCESS; /* skb was consumed */ skb = NULL; goto out; default: /* drop unknown type */ goto out; } out: if (primary_if) batadv_hardif_put(primary_if); if (orig_node) batadv_orig_node_put(orig_node); kfree_skb(skb); return ret; } static int batadv_recv_icmp_ttl_exceeded(struct batadv_priv *bat_priv, struct sk_buff *skb) { struct batadv_hard_iface *primary_if = NULL; struct batadv_orig_node *orig_node = NULL; struct batadv_icmp_packet *icmp_packet; int res, ret = NET_RX_DROP; icmp_packet = (struct batadv_icmp_packet *)skb->data; /* send TTL exceeded if packet is an echo request (traceroute) */ if (icmp_packet->msg_type != BATADV_ECHO_REQUEST) { pr_debug("Warning - can't forward icmp packet from %pM to %pM: ttl exceeded\n", icmp_packet->orig, icmp_packet->dst); goto out; } primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto out; /* get routing information */ orig_node = batadv_orig_hash_find(bat_priv, icmp_packet->orig); if (!orig_node) goto out; /* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, ETH_HLEN) < 0) goto out; icmp_packet = (struct batadv_icmp_packet *)skb->data; ether_addr_copy(icmp_packet->dst, icmp_packet->orig); ether_addr_copy(icmp_packet->orig, primary_if->net_dev->dev_addr); icmp_packet->msg_type = BATADV_TTL_EXCEEDED; icmp_packet->ttl = BATADV_TTL; res = batadv_send_skb_to_orig(skb, orig_node, NULL); if (res == NET_RX_SUCCESS) ret = NET_XMIT_SUCCESS; /* skb was consumed */ skb = NULL; out: if (primary_if) batadv_hardif_put(primary_if); if (orig_node) batadv_orig_node_put(orig_node); kfree_skb(skb); return ret; } /** * batadv_recv_icmp_packet() - Process incoming icmp packet * @skb: incoming packet buffer * @recv_if: incoming hard interface * * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure */ int batadv_recv_icmp_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if) { struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); struct batadv_icmp_header *icmph; struct batadv_icmp_packet_rr *icmp_packet_rr; struct ethhdr *ethhdr; struct batadv_orig_node *orig_node = NULL; int hdr_size = sizeof(struct batadv_icmp_header); int res, ret = NET_RX_DROP; /* drop packet if it has not necessary minimum size */ if (unlikely(!pskb_may_pull(skb, hdr_size))) goto free_skb; ethhdr = eth_hdr(skb); /* packet with unicast indication but non-unicast recipient */ if (!is_valid_ether_addr(ethhdr->h_dest)) goto free_skb; /* packet with broadcast/multicast sender address */ if (is_multicast_ether_addr(ethhdr->h_source)) goto free_skb; /* not for me */ if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) goto free_skb; icmph = (struct batadv_icmp_header *)skb->data; /* add record route information if not full */ if ((icmph->msg_type == BATADV_ECHO_REPLY || icmph->msg_type == BATADV_ECHO_REQUEST) && skb->len >= sizeof(struct batadv_icmp_packet_rr)) { if (skb_linearize(skb) < 0) goto free_skb; /* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, ETH_HLEN) < 0) goto free_skb; ethhdr = eth_hdr(skb); icmph = (struct batadv_icmp_header *)skb->data; icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph; if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN) goto free_skb; ether_addr_copy(icmp_packet_rr->rr[icmp_packet_rr->rr_cur], ethhdr->h_dest); icmp_packet_rr->rr_cur++; } /* packet for me */ if (batadv_is_my_mac(bat_priv, icmph->dst)) return batadv_recv_my_icmp_packet(bat_priv, skb); /* TTL exceeded */ if (icmph->ttl < 2) return batadv_recv_icmp_ttl_exceeded(bat_priv, skb); /* get routing information */ orig_node = batadv_orig_hash_find(bat_priv, icmph->dst); if (!orig_node) goto free_skb; /* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, ETH_HLEN) < 0) goto put_orig_node; icmph = (struct batadv_icmp_header *)skb->data; /* decrement ttl */ icmph->ttl--; /* route it */ res = batadv_send_skb_to_orig(skb, orig_node, recv_if); if (res == NET_XMIT_SUCCESS) ret = NET_RX_SUCCESS; /* skb was consumed */ skb = NULL; put_orig_node: if (orig_node) batadv_orig_node_put(orig_node); free_skb: kfree_skb(skb); return ret; } /** * batadv_check_unicast_packet() - Check for malformed unicast packets * @bat_priv: the bat priv with all the soft interface information * @skb: packet to check * @hdr_size: size of header to pull * * Check for short header and bad addresses in given packet. * * Return: negative value when check fails and 0 otherwise. The negative value * depends on the reason: -ENODATA for bad header, -EBADR for broadcast * destination or source, and -EREMOTE for non-local (other host) destination. */ static int batadv_check_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, int hdr_size) { struct ethhdr *ethhdr; /* drop packet if it has not necessary minimum size */ if (unlikely(!pskb_may_pull(skb, hdr_size))) return -ENODATA; ethhdr = eth_hdr(skb); /* packet with unicast indication but non-unicast recipient */ if (!is_valid_ether_addr(ethhdr->h_dest)) return -EBADR; /* packet with broadcast/multicast sender address */ if (is_multicast_ether_addr(ethhdr->h_source)) return -EBADR; /* not for me */ if (!batadv_is_my_mac(bat_priv, ethhdr->h_dest)) return -EREMOTE; return 0; } /** * batadv_last_bonding_get() - Get last_bonding_candidate of orig_node * @orig_node: originator node whose last bonding candidate should be retrieved * * Return: last bonding candidate of router or NULL if not found * * The object is returned with refcounter increased by 1. */ static struct batadv_orig_ifinfo * batadv_last_bonding_get(struct batadv_orig_node *orig_node) { struct batadv_orig_ifinfo *last_bonding_candidate; spin_lock_bh(&orig_node->neigh_list_lock); last_bonding_candidate = orig_node->last_bonding_candidate; if (last_bonding_candidate) kref_get(&last_bonding_candidate->refcount); spin_unlock_bh(&orig_node->neigh_list_lock); return last_bonding_candidate; } /** * batadv_last_bonding_replace() - Replace last_bonding_candidate of orig_node * @orig_node: originator node whose bonding candidates should be replaced * @new_candidate: new bonding candidate or NULL */ static void batadv_last_bonding_replace(struct batadv_orig_node *orig_node, struct batadv_orig_ifinfo *new_candidate) { struct batadv_orig_ifinfo *old_candidate; spin_lock_bh(&orig_node->neigh_list_lock); old_candidate = orig_node->last_bonding_candidate; if (new_candidate) kref_get(&new_candidate->refcount); orig_node->last_bonding_candidate = new_candidate; spin_unlock_bh(&orig_node->neigh_list_lock); if (old_candidate) batadv_orig_ifinfo_put(old_candidate); } /** * batadv_find_router() - find a suitable router for this originator * @bat_priv: the bat priv with all the soft interface information * @orig_node: the destination node * @recv_if: pointer to interface this packet was received on * * Return: the router which should be used for this orig_node on * this interface, or NULL if not available. */ struct batadv_neigh_node * batadv_find_router(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node, struct batadv_hard_iface *recv_if) { struct batadv_algo_ops *bao = bat_priv->algo_ops; struct batadv_neigh_node *first_candidate_router = NULL; struct batadv_neigh_node *next_candidate_router = NULL; struct batadv_neigh_node *router, *cand_router = NULL; struct batadv_neigh_node *last_cand_router = NULL; struct batadv_orig_ifinfo *cand, *first_candidate = NULL; struct batadv_orig_ifinfo *next_candidate = NULL; struct batadv_orig_ifinfo *last_candidate; bool last_candidate_found = false; if (!orig_node) return NULL; router = batadv_orig_router_get(orig_node, recv_if); if (!router) return router; /* only consider bonding for recv_if == BATADV_IF_DEFAULT (first hop) * and if activated. */ if (!(recv_if == BATADV_IF_DEFAULT && atomic_read(&bat_priv->bonding))) return router; /* bonding: loop through the list of possible routers found * for the various outgoing interfaces and find a candidate after * the last chosen bonding candidate (next_candidate). If no such * router is found, use the first candidate found (the previously * chosen bonding candidate might have been the last one in the list). * If this can't be found either, return the previously chosen * router - obviously there are no other candidates. */ rcu_read_lock(); last_candidate = batadv_last_bonding_get(orig_node); if (last_candidate) last_cand_router = rcu_dereference(last_candidate->router); hlist_for_each_entry_rcu(cand, &orig_node->ifinfo_list, list) { /* acquire some structures and references ... */ if (!kref_get_unless_zero(&cand->refcount)) continue; cand_router = rcu_dereference(cand->router); if (!cand_router) goto next; if (!kref_get_unless_zero(&cand_router->refcount)) { cand_router = NULL; goto next; } /* alternative candidate should be good enough to be * considered */ if (!bao->neigh.is_similar_or_better(cand_router, cand->if_outgoing, router, recv_if)) goto next; /* don't use the same router twice */ if (last_cand_router == cand_router) goto next; /* mark the first possible candidate */ if (!first_candidate) { kref_get(&cand_router->refcount); kref_get(&cand->refcount); first_candidate = cand; first_candidate_router = cand_router; } /* check if the loop has already passed the previously selected * candidate ... this function should select the next candidate * AFTER the previously used bonding candidate. */ if (!last_candidate || last_candidate_found) { next_candidate = cand; next_candidate_router = cand_router; break; } if (last_candidate == cand) last_candidate_found = true; next: /* free references */ if (cand_router) { batadv_neigh_node_put(cand_router); cand_router = NULL; } batadv_orig_ifinfo_put(cand); } rcu_read_unlock(); /* After finding candidates, handle the three cases: * 1) there is a next candidate, use that * 2) there is no next candidate, use the first of the list * 3) there is no candidate at all, return the default router */ if (next_candidate) { batadv_neigh_node_put(router); kref_get(&next_candidate_router->refcount); router = next_candidate_router; batadv_last_bonding_replace(orig_node, next_candidate); } else if (first_candidate) { batadv_neigh_node_put(router); kref_get(&first_candidate_router->refcount); router = first_candidate_router; batadv_last_bonding_replace(orig_node, first_candidate); } else { batadv_last_bonding_replace(orig_node, NULL); } /* cleanup of candidates */ if (first_candidate) { batadv_neigh_node_put(first_candidate_router); batadv_orig_ifinfo_put(first_candidate); } if (next_candidate) { batadv_neigh_node_put(next_candidate_router); batadv_orig_ifinfo_put(next_candidate); } if (last_candidate) batadv_orig_ifinfo_put(last_candidate); return router; } static int batadv_route_unicast_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if) { struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); struct batadv_orig_node *orig_node = NULL; struct batadv_unicast_packet *unicast_packet; struct ethhdr *ethhdr = eth_hdr(skb); int res, hdr_len, ret = NET_RX_DROP; unsigned int len; unicast_packet = (struct batadv_unicast_packet *)skb->data; /* TTL exceeded */ if (unicast_packet->ttl < 2) { pr_debug("Warning - can't forward unicast packet from %pM to %pM: ttl exceeded\n", ethhdr->h_source, unicast_packet->dest); goto free_skb; } /* get routing information */ orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest); if (!orig_node) goto free_skb; /* create a copy of the skb, if needed, to modify it. */ if (skb_cow(skb, ETH_HLEN) < 0) goto put_orig_node; /* decrement ttl */ unicast_packet = (struct batadv_unicast_packet *)skb->data; unicast_packet->ttl--; switch (unicast_packet->packet_type) { case BATADV_UNICAST_4ADDR: hdr_len = sizeof(struct batadv_unicast_4addr_packet); break; case BATADV_UNICAST: hdr_len = sizeof(struct batadv_unicast_packet); break; default: /* other packet types not supported - yet */ hdr_len = -1; break; } if (hdr_len > 0) batadv_skb_set_priority(skb, hdr_len); len = skb->len; res = batadv_send_skb_to_orig(skb, orig_node, recv_if); /* translate transmit result into receive result */ if (res == NET_XMIT_SUCCESS) { ret = NET_RX_SUCCESS; /* skb was transmitted and consumed */ batadv_inc_counter(bat_priv, BATADV_CNT_FORWARD); batadv_add_counter(bat_priv, BATADV_CNT_FORWARD_BYTES, len + ETH_HLEN); } /* skb was consumed */ skb = NULL; put_orig_node: batadv_orig_node_put(orig_node); free_skb: kfree_skb(skb); return ret; } /** * batadv_reroute_unicast_packet() - update the unicast header for re-routing * @bat_priv: the bat priv with all the soft interface information * @skb: unicast packet to process * @unicast_packet: the unicast header to be updated * @dst_addr: the payload destination * @vid: VLAN identifier * * Search the translation table for dst_addr and update the unicast header with * the new corresponding information (originator address where the destination * client currently is and its known TTVN) * * Return: true if the packet header has been updated, false otherwise */ static bool batadv_reroute_unicast_packet(struct batadv_priv *bat_priv, struct sk_buff *skb, struct batadv_unicast_packet *unicast_packet, u8 *dst_addr, unsigned short vid) { struct batadv_orig_node *orig_node = NULL; struct batadv_hard_iface *primary_if = NULL; bool ret = false; u8 *orig_addr, orig_ttvn; if (batadv_is_my_client(bat_priv, dst_addr, vid)) { primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) goto out; orig_addr = primary_if->net_dev->dev_addr; orig_ttvn = (u8)atomic_read(&bat_priv->tt.vn); } else { orig_node = batadv_transtable_search(bat_priv, NULL, dst_addr, vid); if (!orig_node) goto out; if (batadv_compare_eth(orig_node->orig, unicast_packet->dest)) goto out; orig_addr = orig_node->orig; orig_ttvn = (u8)atomic_read(&orig_node->last_ttvn); } /* update the packet header */ skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ether_addr_copy(unicast_packet->dest, orig_addr); unicast_packet->ttvn = orig_ttvn; skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ret = true; out: if (primary_if) batadv_hardif_put(primary_if); if (orig_node) batadv_orig_node_put(orig_node); return ret; } static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv, struct sk_buff *skb, int hdr_len) { struct batadv_unicast_packet *unicast_packet; struct batadv_hard_iface *primary_if; struct batadv_orig_node *orig_node; u8 curr_ttvn, old_ttvn; struct ethhdr *ethhdr; unsigned short vid; int is_old_ttvn; /* check if there is enough data before accessing it */ if (!pskb_may_pull(skb, hdr_len + ETH_HLEN)) return false; /* create a copy of the skb (in case of for re-routing) to modify it. */ if (skb_cow(skb, sizeof(*unicast_packet)) < 0) return false; unicast_packet = (struct batadv_unicast_packet *)skb->data; vid = batadv_get_vid(skb, hdr_len); ethhdr = (struct ethhdr *)(skb->data + hdr_len); /* check if the destination client was served by this node and it is now * roaming. In this case, it means that the node has got a ROAM_ADV * message and that it knows the new destination in the mesh to re-route * the packet to */ if (batadv_tt_local_client_is_roaming(bat_priv, ethhdr->h_dest, vid)) { if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet, ethhdr->h_dest, vid)) batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv, "Rerouting unicast packet to %pM (dst=%pM): Local Roaming\n", unicast_packet->dest, ethhdr->h_dest); /* at this point the mesh destination should have been * substituted with the originator address found in the global * table. If not, let the packet go untouched anyway because * there is nothing the node can do */ return true; } /* retrieve the TTVN known by this node for the packet destination. This * value is used later to check if the node which sent (or re-routed * last time) the packet had an updated information or not */ curr_ttvn = (u8)atomic_read(&bat_priv->tt.vn); if (!batadv_is_my_mac(bat_priv, unicast_packet->dest)) { orig_node = batadv_orig_hash_find(bat_priv, unicast_packet->dest); /* if it is not possible to find the orig_node representing the * destination, the packet can immediately be dropped as it will * not be possible to deliver it */ if (!orig_node) return false; curr_ttvn = (u8)atomic_read(&orig_node->last_ttvn); batadv_orig_node_put(orig_node); } /* check if the TTVN contained in the packet is fresher than what the * node knows */ is_old_ttvn = batadv_seq_before(unicast_packet->ttvn, curr_ttvn); if (!is_old_ttvn) return true; old_ttvn = unicast_packet->ttvn; /* the packet was forged based on outdated network information. Its * destination can possibly be updated and forwarded towards the new * target host */ if (batadv_reroute_unicast_packet(bat_priv, skb, unicast_packet, ethhdr->h_dest, vid)) { batadv_dbg_ratelimited(BATADV_DBG_TT, bat_priv, "Rerouting unicast packet to %pM (dst=%pM): TTVN mismatch old_ttvn=%u new_ttvn=%u\n", unicast_packet->dest, ethhdr->h_dest, old_ttvn, curr_ttvn); return true; } /* the packet has not been re-routed: either the destination is * currently served by this node or there is no destination at all and * it is possible to drop the packet */ if (!batadv_is_my_client(bat_priv, ethhdr->h_dest, vid)) return false; /* update the header in order to let the packet be delivered to this * node's soft interface */ primary_if = batadv_primary_if_get_selected(bat_priv); if (!primary_if) return false; /* update the packet header */ skb_postpull_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); ether_addr_copy(unicast_packet->dest, primary_if->net_dev->dev_addr); unicast_packet->ttvn = curr_ttvn; skb_postpush_rcsum(skb, unicast_packet, sizeof(*unicast_packet)); batadv_hardif_put(primary_if); return true; } /** * batadv_recv_unhandled_unicast_packet() - receive and process packets which * are in the unicast number space but not yet known to the implementation * @skb: unicast tvlv packet to process * @recv_if: pointer to interface this packet was received on * * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP * otherwise. */ int batadv_recv_unhandled_unicast_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if) { struct batadv_unicast_packet *unicast_packet; struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); int check, hdr_size = sizeof(*unicast_packet); check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); if (check < 0) goto free_skb; /* we don't know about this type, drop it. */ unicast_packet = (struct batadv_unicast_packet *)skb->data; if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) goto free_skb; return batadv_route_unicast_packet(skb, recv_if); free_skb: kfree_skb(skb); return NET_RX_DROP; } /** * batadv_recv_unicast_packet() - Process incoming unicast packet * @skb: incoming packet buffer * @recv_if: incoming hard interface * * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure */ int batadv_recv_unicast_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if) { struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); struct batadv_unicast_packet *unicast_packet; struct batadv_unicast_4addr_packet *unicast_4addr_packet; u8 *orig_addr, *orig_addr_gw; struct batadv_orig_node *orig_node = NULL, *orig_node_gw = NULL; int check, hdr_size = sizeof(*unicast_packet); enum batadv_subtype subtype; int ret = NET_RX_DROP; bool is4addr, is_gw; unicast_packet = (struct batadv_unicast_packet *)skb->data; is4addr = unicast_packet->packet_type == BATADV_UNICAST_4ADDR; /* the caller function should have already pulled 2 bytes */ if (is4addr) hdr_size = sizeof(*unicast_4addr_packet); /* function returns -EREMOTE for promiscuous packets */ check = batadv_check_unicast_packet(bat_priv, skb, hdr_size); /* Even though the packet is not for us, we might save it to use for * decoding a later received coded packet */ if (check == -EREMOTE) batadv_nc_skb_store_sniffed_unicast(bat_priv, skb); if (check < 0) goto free_skb; if (!batadv_check_unicast_ttvn(bat_priv, skb, hdr_size)) goto free_skb; unicast_packet = (struct batadv_unicast_packet *)skb->data; /* packet for me */ if (batadv_is_my_mac(bat_priv, unicast_packet->dest)) { /* If this is a unicast packet from another backgone gw, * drop it. */ orig_addr_gw = eth_hdr(skb)->h_source; orig_node_gw = batadv_orig_hash_find(bat_priv, orig_addr_gw); if (orig_node_gw) { is_gw = batadv_bla_is_backbone_gw(skb, orig_node_gw, hdr_size); batadv_orig_node_put(orig_node_gw); if (is_gw) { batadv_dbg(BATADV_DBG_BLA, bat_priv, "%s(): Dropped unicast pkt received from another backbone gw %pM.\n", __func__, orig_addr_gw); goto free_skb; } } if (is4addr) { unicast_4addr_packet = (struct batadv_unicast_4addr_packet *)skb->data; subtype = unicast_4addr_packet->subtype; batadv_dat_inc_counter(bat_priv, subtype); /* Only payload data should be considered for speedy * join. For example, DAT also uses unicast 4addr * types, but those packets should not be considered * for speedy join, since the clients do not actually * reside at the sending originator. */ if (subtype == BATADV_P_DATA) { orig_addr = unicast_4addr_packet->src; orig_node = batadv_orig_hash_find(bat_priv, orig_addr); } } if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) goto rx_success; if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size)) goto rx_success; batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size); batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, orig_node); rx_success: if (orig_node) batadv_orig_node_put(orig_node); return NET_RX_SUCCESS; } ret = batadv_route_unicast_packet(skb, recv_if); /* skb was consumed */ skb = NULL; free_skb: kfree_skb(skb); return ret; } /** * batadv_recv_unicast_tvlv() - receive and process unicast tvlv packets * @skb: unicast tvlv packet to process * @recv_if: pointer to interface this packet was received on * * Return: NET_RX_SUCCESS if the packet has been consumed or NET_RX_DROP * otherwise. */ int batadv_recv_unicast_tvlv(struct sk_buff *skb, struct batadv_hard_iface *recv_if) { struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); struct batadv_unicast_tvlv_packet *unicast_tvlv_packet; unsigned char *tvlv_buff; u16 tvlv_buff_len; int hdr_size = sizeof(*unicast_tvlv_packet); int ret = NET_RX_DROP; if (batadv_check_unicast_packet(bat_priv, skb, hdr_size) < 0) goto free_skb; /* the header is likely to be modified while forwarding */ if (skb_cow(skb, hdr_size) < 0) goto free_skb; /* packet needs to be linearized to access the tvlv content */ if (skb_linearize(skb) < 0) goto free_skb; unicast_tvlv_packet = (struct batadv_unicast_tvlv_packet *)skb->data; tvlv_buff = (unsigned char *)(skb->data + hdr_size); tvlv_buff_len = ntohs(unicast_tvlv_packet->tvlv_len); if (tvlv_buff_len > skb->len - hdr_size) goto free_skb; ret = batadv_tvlv_containers_process(bat_priv, false, NULL, unicast_tvlv_packet->src, unicast_tvlv_packet->dst, tvlv_buff, tvlv_buff_len); if (ret != NET_RX_SUCCESS) { ret = batadv_route_unicast_packet(skb, recv_if); /* skb was consumed */ skb = NULL; } free_skb: kfree_skb(skb); return ret; } /** * batadv_recv_frag_packet() - process received fragment * @skb: the received fragment * @recv_if: interface that the skb is received on * * This function does one of the three following things: 1) Forward fragment, if * the assembled packet will exceed our MTU; 2) Buffer fragment, if we till * lack further fragments; 3) Merge fragments, if we have all needed parts. * * Return: NET_RX_DROP if the skb is not consumed, NET_RX_SUCCESS otherwise. */ int batadv_recv_frag_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if) { struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); struct batadv_orig_node *orig_node_src = NULL; struct batadv_frag_packet *frag_packet; int ret = NET_RX_DROP; if (batadv_check_unicast_packet(bat_priv, skb, sizeof(*frag_packet)) < 0) goto free_skb; frag_packet = (struct batadv_frag_packet *)skb->data; orig_node_src = batadv_orig_hash_find(bat_priv, frag_packet->orig); if (!orig_node_src) goto free_skb; skb->priority = frag_packet->priority + 256; /* Route the fragment if it is not for us and too big to be merged. */ if (!batadv_is_my_mac(bat_priv, frag_packet->dest) && batadv_frag_skb_fwd(skb, recv_if, orig_node_src)) { /* skb was consumed */ skb = NULL; ret = NET_RX_SUCCESS; goto put_orig_node; } batadv_inc_counter(bat_priv, BATADV_CNT_FRAG_RX); batadv_add_counter(bat_priv, BATADV_CNT_FRAG_RX_BYTES, skb->len); /* Add fragment to buffer and merge if possible. */ if (!batadv_frag_skb_buffer(&skb, orig_node_src)) goto put_orig_node; /* Deliver merged packet to the appropriate handler, if it was * merged */ if (skb) { batadv_batman_skb_recv(skb, recv_if->net_dev, &recv_if->batman_adv_ptype, NULL); /* skb was consumed */ skb = NULL; } ret = NET_RX_SUCCESS; put_orig_node: batadv_orig_node_put(orig_node_src); free_skb: kfree_skb(skb); return ret; } /** * batadv_recv_bcast_packet() - Process incoming broadcast packet * @skb: incoming packet buffer * @recv_if: incoming hard interface * * Return: NET_RX_SUCCESS on success or NET_RX_DROP in case of failure */ int batadv_recv_bcast_packet(struct sk_buff *skb, struct batadv_hard_iface *recv_if) { struct batadv_priv *bat_priv = netdev_priv(recv_if->soft_iface); struct batadv_orig_node *orig_node = NULL; struct batadv_bcast_packet *bcast_packet; struct ethhdr *ethhdr; int hdr_size = sizeof(*bcast_packet); int ret = NET_RX_DROP; s32 seq_diff; u32 seqno; /* drop packet if it has not necessary minimum size */ if (unlikely(!pskb_may_pull(skb, hdr_size))) goto free_skb; ethhdr = eth_hdr(skb); /* packet with broadcast indication but unicast recipient */ if (!is_broadcast_ether_addr(ethhdr->h_dest)) goto free_skb; /* packet with broadcast/multicast sender address */ if (is_multicast_ether_addr(ethhdr->h_source)) goto free_skb; /* ignore broadcasts sent by myself */ if (batadv_is_my_mac(bat_priv, ethhdr->h_source)) goto free_skb; bcast_packet = (struct batadv_bcast_packet *)skb->data; /* ignore broadcasts originated by myself */ if (batadv_is_my_mac(bat_priv, bcast_packet->orig)) goto free_skb; if (bcast_packet->ttl < 2) goto free_skb; orig_node = batadv_orig_hash_find(bat_priv, bcast_packet->orig); if (!orig_node) goto free_skb; spin_lock_bh(&orig_node->bcast_seqno_lock); seqno = ntohl(bcast_packet->seqno); /* check whether the packet is a duplicate */ if (batadv_test_bit(orig_node->bcast_bits, orig_node->last_bcast_seqno, seqno)) goto spin_unlock; seq_diff = seqno - orig_node->last_bcast_seqno; /* check whether the packet is old and the host just restarted. */ if (batadv_window_protected(bat_priv, seq_diff, BATADV_BCAST_MAX_AGE, &orig_node->bcast_seqno_reset, NULL)) goto spin_unlock; /* mark broadcast in flood history, update window position * if required. */ if (batadv_bit_get_packet(bat_priv, orig_node->bcast_bits, seq_diff, 1)) orig_node->last_bcast_seqno = seqno; spin_unlock_bh(&orig_node->bcast_seqno_lock); /* check whether this has been sent by another originator before */ if (batadv_bla_check_bcast_duplist(bat_priv, skb)) goto free_skb; batadv_skb_set_priority(skb, sizeof(struct batadv_bcast_packet)); /* rebroadcast packet */ batadv_add_bcast_packet_to_list(bat_priv, skb, 1, false); /* don't hand the broadcast up if it is from an originator * from the same backbone. */ if (batadv_bla_is_backbone_gw(skb, orig_node, hdr_size)) goto free_skb; if (batadv_dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size)) goto rx_success; if (batadv_dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size)) goto rx_success; batadv_dat_snoop_incoming_dhcp_ack(bat_priv, skb, hdr_size); /* broadcast for me */ batadv_interface_rx(recv_if->soft_iface, skb, hdr_size, orig_node); rx_success: ret = NET_RX_SUCCESS; goto out; spin_unlock: spin_unlock_bh(&orig_node->bcast_seqno_lock); free_skb: kfree_skb(skb); out: if (orig_node) batadv_orig_node_put(orig_node); return ret; }