| // SPDX-License-Identifier: GPL-2.0 |
| /* Copyright (C) 2007-2020 B.A.T.M.A.N. contributors: |
| * |
| * Marek Lindner, Simon Wunderlich |
| */ |
| |
| #include "routing.h" |
| #include "main.h" |
| |
| #include <linux/atomic.h> |
| #include <linux/byteorder/generic.h> |
| #include <linux/compiler.h> |
| #include <linux/errno.h> |
| #include <linux/etherdevice.h> |
| #include <linux/if_ether.h> |
| #include <linux/jiffies.h> |
| #include <linux/kref.h> |
| #include <linux/netdevice.h> |
| #include <linux/printk.h> |
| #include <linux/rculist.h> |
| #include <linux/rcupdate.h> |
| #include <linux/skbuff.h> |
| #include <linux/spinlock.h> |
| #include <linux/stddef.h> |
| #include <uapi/linux/batadv_packet.h> |
| |
| #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; |
| } |