drivers/staging/batman-adv/aggregation.c - linux - Git at Google

 /*
  * 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->packet_buff;
 	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 forw_packet *forw_packet_aggr;
 	unsigned long flags;
 	/* FIXME: each batman_if will be attached to a softif */
 	struct bat_priv *bat_priv = netdev_priv(soft_device);

 	/* own packet should always be scheduled */
 	if (!own_packet) {
 		if (!atomic_dec_not_zero(&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(&batman_queue_left);
 		return;
 	}

 	forw_packet_aggr->packet_buff = kmalloc(MAX_AGGREGATION_BYTES,
 						GFP_ATOMIC);
 	if (!forw_packet_aggr->packet_buff) {
 		if (!own_packet)
 			atomic_inc(&batman_queue_left);
 		kfree(forw_packet_aggr);
 		return;
 	}

 	INIT_HLIST_NODE(&forw_packet_aggr->list);

 	forw_packet_aggr->packet_len = packet_len;
 	memcpy(forw_packet_aggr->packet_buff,
 	       packet_buff,
 	       forw_packet_aggr->packet_len);

 	forw_packet_aggr->skb = NULL;
 	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_irqsave(&forw_bat_list_lock, flags);
 	hlist_add_head(&forw_packet_aggr->list, &forw_bat_list);
 	spin_unlock_irqrestore(&forw_bat_list_lock, flags);

 	/* 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)
 {
 	memcpy((forw_packet_aggr->packet_buff + forw_packet_aggr->packet_len),
 	       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;
 	unsigned long flags;

 	/* find position for the packet in the forward queue */
 	spin_lock_irqsave(&forw_bat_list_lock, flags);
 	/* own packets are not to be aggregated */
 	if ((atomic_read(&bat_priv->aggregation_enabled)) && (!own_packet)) {
 		hlist_for_each_entry(forw_packet_pos, tmp_node, &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 == NULL) {
 		/* the following section can run without the lock */
 		spin_unlock_irqrestore(&forw_bat_list_lock, flags);

 		/**
 		 * 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->aggregation_enabled)))
 			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_irqrestore(&forw_bat_list_lock, flags);
 	}
 }

 /* 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;

 	while (aggregated_packet(buff_pos, packet_len,
 				 batman_packet->num_hna)) {

 		/* 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);
 	}
 }
	/*
	* 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->packet_buff;
	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 forw_packet *forw_packet_aggr;
	unsigned long flags;
	/* FIXME: each batman_if will be attached to a softif */
	struct bat_priv *bat_priv = netdev_priv(soft_device);

	/* own packet should always be scheduled */
	if (!own_packet) {
	if (!atomic_dec_not_zero(&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(&batman_queue_left);
	return;
	}

	forw_packet_aggr->packet_buff = kmalloc(MAX_AGGREGATION_BYTES,
	GFP_ATOMIC);
	if (!forw_packet_aggr->packet_buff) {
	if (!own_packet)
	atomic_inc(&batman_queue_left);
	kfree(forw_packet_aggr);
	return;
	}

	INIT_HLIST_NODE(&forw_packet_aggr->list);

	forw_packet_aggr->packet_len = packet_len;
	memcpy(forw_packet_aggr->packet_buff,
	packet_buff,
	forw_packet_aggr->packet_len);

	forw_packet_aggr->skb = NULL;
	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_irqsave(&forw_bat_list_lock, flags);
	hlist_add_head(&forw_packet_aggr->list, &forw_bat_list);
	spin_unlock_irqrestore(&forw_bat_list_lock, flags);

	/* 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)
	{
	memcpy((forw_packet_aggr->packet_buff + forw_packet_aggr->packet_len),
	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;
	unsigned long flags;

	/* find position for the packet in the forward queue */
	spin_lock_irqsave(&forw_bat_list_lock, flags);
	/* own packets are not to be aggregated */
	if ((atomic_read(&bat_priv->aggregation_enabled)) && (!own_packet)) {
	hlist_for_each_entry(forw_packet_pos, tmp_node, &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 == NULL) {
	/* the following section can run without the lock */
	spin_unlock_irqrestore(&forw_bat_list_lock, flags);

	/**
	* 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->aggregation_enabled)))
	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_irqrestore(&forw_bat_list_lock, flags);
	}
	}

	/* 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;

	while (aggregated_packet(buff_pos, packet_len,
	batman_packet->num_hna)) {

	/* 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);
	}
	}