diff options
Diffstat (limited to 'net/batman-adv')
| -rw-r--r-- | net/batman-adv/network-coding.c | 232 | ||||
| -rw-r--r-- | net/batman-adv/soft-interface.c | 4 | ||||
| -rw-r--r-- | net/batman-adv/types.h | 10 |
3 files changed, 246 insertions, 0 deletions
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c index 3d2ed2f..5728079 100644 --- a/net/batman-adv/network-coding.c +++ b/net/batman-adv/network-coding.c @@ -25,11 +25,14 @@ #include "send.h" #include "originator.h" #include "hard-interface.h" +#include "routing.h" static struct lock_class_key batadv_nc_coding_hash_lock_class_key; static struct lock_class_key batadv_nc_decoding_hash_lock_class_key; static void batadv_nc_worker(struct work_struct *work); +static int batadv_nc_recv_coded_packet(struct sk_buff *skb, + struct batadv_hard_iface *recv_if); /** * batadv_nc_start_timer - initialise the nc periodic worker @@ -67,6 +70,11 @@ int batadv_nc_init(struct batadv_priv *bat_priv) batadv_hash_set_lock_class(bat_priv->nc.coding_hash, &batadv_nc_decoding_hash_lock_class_key); + /* Register our packet type */ + if (batadv_recv_handler_register(BATADV_CODED, + batadv_nc_recv_coded_packet) < 0) + goto err; + INIT_DELAYED_WORK(&bat_priv->nc.work, batadv_nc_worker); batadv_nc_start_timer(bat_priv); @@ -1486,11 +1494,235 @@ void batadv_nc_skb_store_sniffed_unicast(struct batadv_priv *bat_priv, } /** + * batadv_nc_skb_decode_packet - decode given skb using the decode data stored + * in nc_packet + * @skb: unicast skb to decode + * @nc_packet: decode data needed to decode the skb + * + * Returns pointer to decoded unicast packet if the packet was decoded or NULL + * in case of an error. + */ +static struct batadv_unicast_packet * +batadv_nc_skb_decode_packet(struct sk_buff *skb, + struct batadv_nc_packet *nc_packet) +{ + const int h_size = sizeof(struct batadv_unicast_packet); + const int h_diff = sizeof(struct batadv_coded_packet) - h_size; + struct batadv_unicast_packet *unicast_packet; + struct batadv_coded_packet coded_packet_tmp; + struct ethhdr *ethhdr, ethhdr_tmp; + uint8_t *orig_dest, ttl, ttvn; + unsigned int coding_len; + + /* Save headers temporarily */ + memcpy(&coded_packet_tmp, skb->data, sizeof(coded_packet_tmp)); + memcpy(ðhdr_tmp, skb_mac_header(skb), sizeof(ethhdr_tmp)); + + if (skb_cow(skb, 0) < 0) + return NULL; + + if (unlikely(!skb_pull_rcsum(skb, h_diff))) + return NULL; + + /* Data points to batman header, so set mac header 14 bytes before + * and network to data + */ + skb_set_mac_header(skb, -ETH_HLEN); + skb_reset_network_header(skb); + + /* Reconstruct original mac header */ + ethhdr = (struct ethhdr *)skb_mac_header(skb); + memcpy(ethhdr, ðhdr_tmp, sizeof(*ethhdr)); + + /* Select the correct unicast header information based on the location + * of our mac address in the coded_packet header + */ + if (batadv_is_my_mac(coded_packet_tmp.second_dest)) { + /* If we are the second destination the packet was overheard, + * so the Ethernet address must be copied to h_dest and + * pkt_type changed from PACKET_OTHERHOST to PACKET_HOST + */ + memcpy(ethhdr->h_dest, coded_packet_tmp.second_dest, ETH_ALEN); + skb->pkt_type = PACKET_HOST; + + orig_dest = coded_packet_tmp.second_orig_dest; + ttl = coded_packet_tmp.second_ttl; + ttvn = coded_packet_tmp.second_ttvn; + } else { + orig_dest = coded_packet_tmp.first_orig_dest; + ttl = coded_packet_tmp.header.ttl; + ttvn = coded_packet_tmp.first_ttvn; + } + + coding_len = ntohs(coded_packet_tmp.coded_len); + + if (coding_len > skb->len) + return NULL; + + /* Here the magic is reversed: + * extract the missing packet from the received coded packet + */ + batadv_nc_memxor(skb->data + h_size, + nc_packet->skb->data + h_size, + coding_len); + + /* Resize decoded skb if decoded with larger packet */ + if (nc_packet->skb->len > coding_len + h_size) + pskb_trim_rcsum(skb, coding_len + h_size); + + /* Create decoded unicast packet */ + unicast_packet = (struct batadv_unicast_packet *)skb->data; + unicast_packet->header.packet_type = BATADV_UNICAST; + unicast_packet->header.version = BATADV_COMPAT_VERSION; + unicast_packet->header.ttl = ttl; + memcpy(unicast_packet->dest, orig_dest, ETH_ALEN); + unicast_packet->ttvn = ttvn; + + batadv_nc_packet_free(nc_packet); + return unicast_packet; +} + +/** + * batadv_nc_find_decoding_packet - search through buffered decoding data to + * find the data needed to decode the coded packet + * @bat_priv: the bat priv with all the soft interface information + * @ethhdr: pointer to the ethernet header inside the coded packet + * @coded: coded packet we try to find decode data for + * + * Returns pointer to nc packet if the needed data was found or NULL otherwise. + */ +static struct batadv_nc_packet * +batadv_nc_find_decoding_packet(struct batadv_priv *bat_priv, + struct ethhdr *ethhdr, + struct batadv_coded_packet *coded) +{ + struct batadv_hashtable *hash = bat_priv->nc.decoding_hash; + struct batadv_nc_packet *tmp_nc_packet, *nc_packet = NULL; + struct batadv_nc_path *nc_path, nc_path_key; + uint8_t *dest, *source; + __be32 packet_id; + int index; + + if (!hash) + return NULL; + + /* Select the correct packet id based on the location of our mac-addr */ + dest = ethhdr->h_source; + if (!batadv_is_my_mac(coded->second_dest)) { + source = coded->second_source; + packet_id = coded->second_crc; + } else { + source = coded->first_source; + packet_id = coded->first_crc; + } + + batadv_nc_hash_key_gen(&nc_path_key, source, dest); + index = batadv_nc_hash_choose(&nc_path_key, hash->size); + + /* Search for matching coding path */ + rcu_read_lock(); + hlist_for_each_entry_rcu(nc_path, &hash->table[index], hash_entry) { + /* Find matching nc_packet */ + spin_lock_bh(&nc_path->packet_list_lock); + list_for_each_entry(tmp_nc_packet, + &nc_path->packet_list, list) { + if (packet_id == tmp_nc_packet->packet_id) { + list_del(&tmp_nc_packet->list); + + nc_packet = tmp_nc_packet; + break; + } + } + spin_unlock_bh(&nc_path->packet_list_lock); + + if (nc_packet) + break; + } + rcu_read_unlock(); + + if (!nc_packet) + batadv_dbg(BATADV_DBG_NC, bat_priv, + "No decoding packet found for %u\n", packet_id); + + return nc_packet; +} + +/** + * batadv_nc_recv_coded_packet - try to decode coded packet and enqueue the + * resulting unicast packet + * @skb: incoming coded packet + * @recv_if: pointer to interface this packet was received on + */ +static int batadv_nc_recv_coded_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_coded_packet *coded_packet; + struct batadv_nc_packet *nc_packet; + struct ethhdr *ethhdr; + int hdr_size = sizeof(*coded_packet); + + /* Check if network coding is enabled */ + if (!atomic_read(&bat_priv->network_coding)) + return NET_RX_DROP; + + /* Make sure we can access (and remove) header */ + if (unlikely(!pskb_may_pull(skb, hdr_size))) + return NET_RX_DROP; + + coded_packet = (struct batadv_coded_packet *)skb->data; + ethhdr = (struct ethhdr *)skb_mac_header(skb); + + /* Verify frame is destined for us */ + if (!batadv_is_my_mac(ethhdr->h_dest) && + !batadv_is_my_mac(coded_packet->second_dest)) + return NET_RX_DROP; + + /* Update stat counter */ + if (batadv_is_my_mac(coded_packet->second_dest)) + batadv_inc_counter(bat_priv, BATADV_CNT_NC_SNIFFED); + + nc_packet = batadv_nc_find_decoding_packet(bat_priv, ethhdr, + coded_packet); + if (!nc_packet) { + batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); + return NET_RX_DROP; + } + + /* Make skb's linear, because decoding accesses the entire buffer */ + if (skb_linearize(skb) < 0) + goto free_nc_packet; + + if (skb_linearize(nc_packet->skb) < 0) + goto free_nc_packet; + + /* Decode the packet */ + unicast_packet = batadv_nc_skb_decode_packet(skb, nc_packet); + if (!unicast_packet) { + batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE_FAILED); + goto free_nc_packet; + } + + /* Mark packet as decoded to do correct recoding when forwarding */ + BATADV_SKB_CB(skb)->decoded = true; + batadv_inc_counter(bat_priv, BATADV_CNT_NC_DECODE); + batadv_add_counter(bat_priv, BATADV_CNT_NC_DECODE_BYTES, + skb->len + ETH_HLEN); + return batadv_recv_unicast_packet(skb, recv_if); + +free_nc_packet: + batadv_nc_packet_free(nc_packet); + return NET_RX_DROP; +} + +/** * batadv_nc_free - clean up network coding memory * @bat_priv: the bat priv with all the soft interface information */ void batadv_nc_free(struct batadv_priv *bat_priv) { + batadv_recv_handler_unregister(BATADV_CODED); cancel_delayed_work_sync(&bat_priv->nc.work); batadv_nc_purge_paths(bat_priv, bat_priv->nc.coding_hash, NULL); diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 75204ec..f93ae42 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -671,6 +671,10 @@ static const struct { { "nc_recode" }, { "nc_recode_bytes" }, { "nc_buffer" }, + { "nc_decode" }, + { "nc_decode_bytes" }, + { "nc_decode_failed" }, + { "nc_sniffed" }, #endif }; diff --git a/net/batman-adv/types.h b/net/batman-adv/types.h index 5f3640d..aba8364 100644 --- a/net/batman-adv/types.h +++ b/net/batman-adv/types.h @@ -280,6 +280,12 @@ struct batadv_bcast_duplist_entry { * @BATADV_CNT_NC_RECODE: transmitted nc-recombined traffic packet counter * @BATADV_CNT_NC_RECODE_BYTES: transmitted nc-recombined traffic bytes counter * @BATADV_CNT_NC_BUFFER: counter for packets buffered for later nc decoding + * @BATADV_CNT_NC_DECODE: received and nc-decoded traffic packet counter + * @BATADV_CNT_NC_DECODE_BYTES: received and nc-decoded traffic bytes counter + * @BATADV_CNT_NC_DECODE_FAILED: received and decode-failed traffic packet + * counter + * @BATADV_CNT_NC_SNIFFED: counter for nc-decoded packets received in promisc + * mode. * @BATADV_CNT_NUM: number of traffic counters */ enum batadv_counters { @@ -313,6 +319,10 @@ enum batadv_counters { BATADV_CNT_NC_RECODE, BATADV_CNT_NC_RECODE_BYTES, BATADV_CNT_NC_BUFFER, + BATADV_CNT_NC_DECODE, + BATADV_CNT_NC_DECODE_BYTES, + BATADV_CNT_NC_DECODE_FAILED, + BATADV_CNT_NC_SNIFFED, #endif BATADV_CNT_NUM, }; 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