From c6c8fea29769d998d94fcec9b9f14d4b52b349d3 Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Mon, 13 Dec 2010 11:19:28 +0000 Subject: net: Add batman-adv meshing protocol B.A.T.M.A.N. (better approach to mobile ad-hoc networking) is a routing protocol for multi-hop ad-hoc mesh networks. The networks may be wired or wireless. See http://www.open-mesh.org/ for more information and user space tools. Signed-off-by: Sven Eckelmann Signed-off-by: David S. Miller --- net/batman-adv/aggregation.c | 273 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 273 insertions(+) create mode 100644 net/batman-adv/aggregation.c (limited to 'net/batman-adv/aggregation.c') diff --git a/net/batman-adv/aggregation.c b/net/batman-adv/aggregation.c new file mode 100644 index 000000000000..3850a3ecf947 --- /dev/null +++ b/net/batman-adv/aggregation.c @@ -0,0 +1,273 @@ +/* + * Copyright (C) 2007-2010 B.A.T.M.A.N. contributors: + * + * Marek Lindner, Simon Wunderlich + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA + * + */ + +#include "main.h" +#include "aggregation.h" +#include "send.h" +#include "routing.h" + +/* calculate the size of the hna information for a given packet */ +static int hna_len(struct batman_packet *batman_packet) +{ + return batman_packet->num_hna * ETH_ALEN; +} + +/* return true if new_packet can be aggregated with forw_packet */ +static bool can_aggregate_with(struct batman_packet *new_batman_packet, + int packet_len, + unsigned long send_time, + bool directlink, + struct batman_if *if_incoming, + struct forw_packet *forw_packet) +{ + struct batman_packet *batman_packet = + (struct batman_packet *)forw_packet->skb->data; + int aggregated_bytes = forw_packet->packet_len + packet_len; + + /** + * we can aggregate the current packet to this aggregated packet + * if: + * + * - the send time is within our MAX_AGGREGATION_MS time + * - the resulting packet wont be bigger than + * MAX_AGGREGATION_BYTES + */ + + if (time_before(send_time, forw_packet->send_time) && + time_after_eq(send_time + msecs_to_jiffies(MAX_AGGREGATION_MS), + forw_packet->send_time) && + (aggregated_bytes <= MAX_AGGREGATION_BYTES)) { + + /** + * check aggregation compatibility + * -> direct link packets are broadcasted on + * their interface only + * -> aggregate packet if the current packet is + * a "global" packet as well as the base + * packet + */ + + /* packets without direct link flag and high TTL + * are flooded through the net */ + if ((!directlink) && + (!(batman_packet->flags & DIRECTLINK)) && + (batman_packet->ttl != 1) && + + /* own packets originating non-primary + * interfaces leave only that interface */ + ((!forw_packet->own) || + (forw_packet->if_incoming->if_num == 0))) + return true; + + /* if the incoming packet is sent via this one + * interface only - we still can aggregate */ + if ((directlink) && + (new_batman_packet->ttl == 1) && + (forw_packet->if_incoming == if_incoming) && + + /* packets from direct neighbors or + * own secondary interface packets + * (= secondary interface packets in general) */ + (batman_packet->flags & DIRECTLINK || + (forw_packet->own && + forw_packet->if_incoming->if_num != 0))) + return true; + } + + return false; +} + +#define atomic_dec_not_zero(v) atomic_add_unless((v), -1, 0) +/* create a new aggregated packet and add this packet to it */ +static void new_aggregated_packet(unsigned char *packet_buff, int packet_len, + unsigned long send_time, bool direct_link, + struct batman_if *if_incoming, + int own_packet) +{ + struct bat_priv *bat_priv = netdev_priv(if_incoming->soft_iface); + struct forw_packet *forw_packet_aggr; + unsigned char *skb_buff; + + /* own packet should always be scheduled */ + if (!own_packet) { + if (!atomic_dec_not_zero(&bat_priv->batman_queue_left)) { + bat_dbg(DBG_BATMAN, bat_priv, + "batman packet queue full\n"); + return; + } + } + + forw_packet_aggr = kmalloc(sizeof(struct forw_packet), GFP_ATOMIC); + if (!forw_packet_aggr) { + if (!own_packet) + atomic_inc(&bat_priv->batman_queue_left); + return; + } + + if ((atomic_read(&bat_priv->aggregated_ogms)) && + (packet_len < MAX_AGGREGATION_BYTES)) + forw_packet_aggr->skb = dev_alloc_skb(MAX_AGGREGATION_BYTES + + sizeof(struct ethhdr)); + else + forw_packet_aggr->skb = dev_alloc_skb(packet_len + + sizeof(struct ethhdr)); + + if (!forw_packet_aggr->skb) { + if (!own_packet) + atomic_inc(&bat_priv->batman_queue_left); + kfree(forw_packet_aggr); + return; + } + skb_reserve(forw_packet_aggr->skb, sizeof(struct ethhdr)); + + INIT_HLIST_NODE(&forw_packet_aggr->list); + + skb_buff = skb_put(forw_packet_aggr->skb, packet_len); + forw_packet_aggr->packet_len = packet_len; + memcpy(skb_buff, packet_buff, packet_len); + + forw_packet_aggr->own = own_packet; + forw_packet_aggr->if_incoming = if_incoming; + forw_packet_aggr->num_packets = 0; + forw_packet_aggr->direct_link_flags = 0; + forw_packet_aggr->send_time = send_time; + + /* save packet direct link flag status */ + if (direct_link) + forw_packet_aggr->direct_link_flags |= 1; + + /* add new packet to packet list */ + spin_lock_bh(&bat_priv->forw_bat_list_lock); + hlist_add_head(&forw_packet_aggr->list, &bat_priv->forw_bat_list); + spin_unlock_bh(&bat_priv->forw_bat_list_lock); + + /* start timer for this packet */ + INIT_DELAYED_WORK(&forw_packet_aggr->delayed_work, + send_outstanding_bat_packet); + queue_delayed_work(bat_event_workqueue, + &forw_packet_aggr->delayed_work, + send_time - jiffies); +} + +/* aggregate a new packet into the existing aggregation */ +static void aggregate(struct forw_packet *forw_packet_aggr, + unsigned char *packet_buff, + int packet_len, + bool direct_link) +{ + unsigned char *skb_buff; + + skb_buff = skb_put(forw_packet_aggr->skb, packet_len); + memcpy(skb_buff, packet_buff, packet_len); + forw_packet_aggr->packet_len += packet_len; + forw_packet_aggr->num_packets++; + + /* save packet direct link flag status */ + if (direct_link) + forw_packet_aggr->direct_link_flags |= + (1 << forw_packet_aggr->num_packets); +} + +void add_bat_packet_to_list(struct bat_priv *bat_priv, + unsigned char *packet_buff, int packet_len, + struct batman_if *if_incoming, char own_packet, + unsigned long send_time) +{ + /** + * _aggr -> pointer to the packet we want to aggregate with + * _pos -> pointer to the position in the queue + */ + struct forw_packet *forw_packet_aggr = NULL, *forw_packet_pos = NULL; + struct hlist_node *tmp_node; + struct batman_packet *batman_packet = + (struct batman_packet *)packet_buff; + bool direct_link = batman_packet->flags & DIRECTLINK ? 1 : 0; + + /* find position for the packet in the forward queue */ + spin_lock_bh(&bat_priv->forw_bat_list_lock); + /* own packets are not to be aggregated */ + if ((atomic_read(&bat_priv->aggregated_ogms)) && (!own_packet)) { + hlist_for_each_entry(forw_packet_pos, tmp_node, + &bat_priv->forw_bat_list, list) { + if (can_aggregate_with(batman_packet, + packet_len, + send_time, + direct_link, + if_incoming, + forw_packet_pos)) { + forw_packet_aggr = forw_packet_pos; + break; + } + } + } + + /* nothing to aggregate with - either aggregation disabled or no + * suitable aggregation packet found */ + if (!forw_packet_aggr) { + /* the following section can run without the lock */ + spin_unlock_bh(&bat_priv->forw_bat_list_lock); + + /** + * if we could not aggregate this packet with one of the others + * we hold it back for a while, so that it might be aggregated + * later on + */ + if ((!own_packet) && + (atomic_read(&bat_priv->aggregated_ogms))) + send_time += msecs_to_jiffies(MAX_AGGREGATION_MS); + + new_aggregated_packet(packet_buff, packet_len, + send_time, direct_link, + if_incoming, own_packet); + } else { + aggregate(forw_packet_aggr, + packet_buff, packet_len, + direct_link); + spin_unlock_bh(&bat_priv->forw_bat_list_lock); + } +} + +/* unpack the aggregated packets and process them one by one */ +void receive_aggr_bat_packet(struct ethhdr *ethhdr, unsigned char *packet_buff, + int packet_len, struct batman_if *if_incoming) +{ + struct batman_packet *batman_packet; + int buff_pos = 0; + unsigned char *hna_buff; + + batman_packet = (struct batman_packet *)packet_buff; + + do { + /* network to host order for our 32bit seqno, and the + orig_interval. */ + batman_packet->seqno = ntohl(batman_packet->seqno); + + hna_buff = packet_buff + buff_pos + BAT_PACKET_LEN; + receive_bat_packet(ethhdr, batman_packet, + hna_buff, hna_len(batman_packet), + if_incoming); + + buff_pos += BAT_PACKET_LEN + hna_len(batman_packet); + batman_packet = (struct batman_packet *) + (packet_buff + buff_pos); + } while (aggregated_packet(buff_pos, packet_len, + batman_packet->num_hna)); +} -- cgit v1.2.3