Commit 6bc45440 authored by Linus Lüssing's avatar Linus Lüssing Committed by Simon Wunderlich
Browse files

batman-adv: mcast: shorten multicast tt/tvlv worker spinlock section 



It is not necessary to hold the mla_lock spinlock during the whole
multicast tt/tvlv worker callback. Just holding it during the checks and
updates of the bat_priv stored multicast flags and mla_list is enough.

Therefore this patch splits batadv_mcast_mla_tvlv_update() in two:
batadv_mcast_mla_flags_get() at the beginning of the worker to gather
and calculate the new multicast flags, which does not need any locking
as it neither reads from nor writes to bat_priv->mcast.

And batadv_mcast_mla_flags_update() at the end of the worker which
commits the newly calculated flags and lists to bat_priv->mcast and
therefore needs the lock.

Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: default avatarSven Eckelmann <sven@narfation.org>
Signed-off-by: default avatarSimon Wunderlich <sw@simonwunderlich.de>
parent 68a600de

net/batman-adv/multicast.c

+140 −132
Original line number Diff line number Diff line
@@ -71,6 +71,80 @@ static void batadv_mcast_start_timer(struct batadv_priv *bat_priv) 
			   msecs_to_jiffies(BATADV_MCAST_WORK_PERIOD));

}



/**

 * batadv_mcast_has_bridge() - check whether the soft-iface is bridged

 * @bat_priv: the bat priv with all the soft interface information

 *

 * Checks whether there is a bridge on top of our soft interface.

 *

 * Return: true if there is a bridge, false otherwise.

 */

static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv)

{

	struct net_device *upper = bat_priv->soft_iface;



	rcu_read_lock();

	do {

		upper = netdev_master_upper_dev_get_rcu(upper);

	} while (upper && !(upper->priv_flags & IFF_EBRIDGE));

	rcu_read_unlock();



	return upper;

}



/**

 * batadv_mcast_mla_flags_get() - get the new multicast flags

 * @bat_priv: the bat priv with all the soft interface information

 *

 * Return: A set of flags for the current/next TVLV, querier and

 * bridge state.

 */

static struct batadv_mcast_mla_flags

batadv_mcast_mla_flags_get(struct batadv_priv *bat_priv)

{

	struct net_device *dev = bat_priv->soft_iface;

	struct batadv_mcast_querier_state *qr4, *qr6;

	struct batadv_mcast_mla_flags mla_flags;



	memset(&mla_flags, 0, sizeof(mla_flags));

	mla_flags.enabled = 1;



	if (!batadv_mcast_has_bridge(bat_priv))

		return mla_flags;



	mla_flags.bridged = 1;

	qr4 = &mla_flags.querier_ipv4;

	qr6 = &mla_flags.querier_ipv6;



	if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING))

		pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n");



	qr4->exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP);

	qr4->shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP);



	qr6->exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6);

	qr6->shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6);



	mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES;



	/* 1) If no querier exists at all, then multicast listeners on

	 *    our local TT clients behind the bridge will keep silent.

	 * 2) If the selected querier is on one of our local TT clients,

	 *    behind the bridge, then this querier might shadow multicast

	 *    listeners on our local TT clients, behind this bridge.

	 *

	 * In both cases, we will signalize other batman nodes that

	 * we need all multicast traffic of the according protocol.

	 */

	if (!qr4->exists || qr4->shadowing)

		mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_IPV4;



	if (!qr6->exists || qr6->shadowing)

		mla_flags.tvlv_flags |= BATADV_MCAST_WANT_ALL_IPV6;



	return mla_flags;

}



/**

 * batadv_mcast_get_bridge() - get the bridge on top of the softif if it exists

 * @soft_iface: netdev struct of the mesh interface
@@ -127,9 +201,9 @@ static bool batadv_mcast_addr_is_ipv6(const u8 *addr) 


/**

 * batadv_mcast_mla_softif_get() - get softif multicast listeners

 * @bat_priv: the bat priv with all the soft interface information

 * @dev: the device to collect multicast addresses from

 * @mcast_list: a list to put found addresses into

 * @flags: flags indicating the new multicast state

 *

 * Collects multicast addresses of multicast listeners residing

 * on this kernel on the given soft interface, dev, in
@@ -144,12 +218,13 @@ static bool batadv_mcast_addr_is_ipv6(const u8 *addr) 
 * Return: -ENOMEM on memory allocation error or the number of

 * items added to the mcast_list otherwise.

 */

static int batadv_mcast_mla_softif_get(struct batadv_priv *bat_priv,

				       struct net_device *dev,

				       struct hlist_head *mcast_list)

static int

batadv_mcast_mla_softif_get(struct net_device *dev,

			    struct hlist_head *mcast_list,

			    struct batadv_mcast_mla_flags *flags)

{

	bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4;

	bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6;

	bool all_ipv4 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4;

	bool all_ipv6 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6;

	struct net_device *bridge = batadv_mcast_get_bridge(dev);

	struct netdev_hw_addr *mc_list_entry;

	struct batadv_hw_addr *new;
@@ -227,9 +302,9 @@ static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src) 


/**

 * batadv_mcast_mla_bridge_get() - get bridged-in multicast listeners

 * @bat_priv: the bat priv with all the soft interface information

 * @dev: a bridge slave whose bridge to collect multicast addresses from

 * @mcast_list: a list to put found addresses into

 * @flags: flags indicating the new multicast state

 *

 * Collects multicast addresses of multicast listeners residing

 * on foreign, non-mesh devices which we gave access to our mesh via
@@ -239,13 +314,13 @@ static void batadv_mcast_mla_br_addr_cpy(char *dst, const struct br_ip *src) 
 * Return: -ENOMEM on memory allocation error or the number of

 * items added to the mcast_list otherwise.

 */

static int batadv_mcast_mla_bridge_get(struct batadv_priv *bat_priv,

				       struct net_device *dev,

				       struct hlist_head *mcast_list)

static int batadv_mcast_mla_bridge_get(struct net_device *dev,

				       struct hlist_head *mcast_list,

				       struct batadv_mcast_mla_flags *flags)

{

	struct list_head bridge_mcast_list = LIST_HEAD_INIT(bridge_mcast_list);

	bool all_ipv4 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV4;

	bool all_ipv6 = bat_priv->mcast.flags & BATADV_MCAST_WANT_ALL_IPV6;

	bool all_ipv4 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV4;

	bool all_ipv6 = flags->tvlv_flags & BATADV_MCAST_WANT_ALL_IPV6;

	struct br_ip_list *br_ip_entry, *tmp;

	struct batadv_hw_addr *new;

	u8 mcast_addr[ETH_ALEN];
@@ -369,27 +444,6 @@ static void batadv_mcast_mla_tt_add(struct batadv_priv *bat_priv, 
	}

}



/**

 * batadv_mcast_has_bridge() - check whether the soft-iface is bridged

 * @bat_priv: the bat priv with all the soft interface information

 *

 * Checks whether there is a bridge on top of our soft interface.

 *

 * Return: true if there is a bridge, false otherwise.

 */

static bool batadv_mcast_has_bridge(struct batadv_priv *bat_priv)

{

	struct net_device *upper = bat_priv->soft_iface;



	rcu_read_lock();

	do {

		upper = netdev_master_upper_dev_get_rcu(upper);

	} while (upper && !(upper->priv_flags & IFF_EBRIDGE));

	rcu_read_unlock();



	return upper;

}



/**

 * batadv_mcast_querier_log() - debug output regarding the querier status on

 *  link
@@ -424,7 +478,7 @@ batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto, 
		batadv_info(bat_priv->soft_iface,

			    "%s Querier disappeared - multicast optimizations disabled\n",

			    str_proto);

	else if (!bat_priv->mcast.bridged && !new_state->exists)

	else if (!bat_priv->mcast.mla_flags.bridged && !new_state->exists)

		batadv_info(bat_priv->soft_iface,

			    "No %s Querier present - multicast optimizations disabled\n",

			    str_proto);
@@ -446,9 +500,7 @@ batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto, 
 * batadv_mcast_bridge_log() - debug output for topology changes in bridged

 *  setups

 * @bat_priv: the bat priv with all the soft interface information

 * @bridged: a flag about whether the soft interface is currently bridged or not

 * @querier_ipv4: (maybe) new status of a potential, selected IGMP querier

 * @querier_ipv6: (maybe) new status of a potential, selected MLD querier

 * @new_flags: flags indicating the new multicast state

 *

 * If no bridges are ever used on this node, then this function does nothing.

 *
@@ -461,38 +513,40 @@ batadv_mcast_querier_log(struct batadv_priv *bat_priv, char *str_proto, 
 * multicast flags this node is going to set.

 */

static void

batadv_mcast_bridge_log(struct batadv_priv *bat_priv, bool bridged,

			struct batadv_mcast_querier_state *querier_ipv4,

			struct batadv_mcast_querier_state *querier_ipv6)

batadv_mcast_bridge_log(struct batadv_priv *bat_priv,

			struct batadv_mcast_mla_flags *new_flags)

{

	if (!bat_priv->mcast.bridged && bridged)

	struct batadv_mcast_mla_flags *old_flags = &bat_priv->mcast.mla_flags;



	if (!old_flags->bridged && new_flags->bridged)

		batadv_dbg(BATADV_DBG_MCAST, bat_priv,

			   "Bridge added: Setting Unsnoopables(U)-flag\n");

	else if (bat_priv->mcast.bridged && !bridged)

	else if (old_flags->bridged && !new_flags->bridged)

		batadv_dbg(BATADV_DBG_MCAST, bat_priv,

			   "Bridge removed: Unsetting Unsnoopables(U)-flag\n");



	if (bridged) {

	if (new_flags->bridged) {

		batadv_mcast_querier_log(bat_priv, "IGMP",

					 &bat_priv->mcast.querier_ipv4,

					 querier_ipv4);

					 &old_flags->querier_ipv4,

					 &new_flags->querier_ipv4);

		batadv_mcast_querier_log(bat_priv, "MLD",

					 &bat_priv->mcast.querier_ipv6,

					 querier_ipv6);

					 &old_flags->querier_ipv6,

					 &new_flags->querier_ipv6);

	}

}



/**

 * batadv_mcast_flags_logs() - output debug information about mcast flag changes

 * @bat_priv: the bat priv with all the soft interface information

 * @flags: flags indicating the new multicast state

 * @flags: TVLV flags indicating the new multicast state

 *

 * Whenever the multicast flags this nodes announces changes (@mcast_flags vs.

 * bat_priv->mcast.flags), this notifies userspace via the 'mcast' log level.

 * Whenever the multicast TVLV flags this nodes announces change this notifies

 * userspace via the 'mcast' log level.

 */

static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags)

{

	u8 old_flags = bat_priv->mcast.flags;

	bool old_enabled = bat_priv->mcast.mla_flags.enabled;

	u8 old_flags = bat_priv->mcast.mla_flags.tvlv_flags;

	char str_old_flags[] = "[...]";



	sprintf(str_old_flags, "[%c%c%c]",
@@ -502,85 +556,39 @@ static void batadv_mcast_flags_log(struct batadv_priv *bat_priv, u8 flags) 


	batadv_dbg(BATADV_DBG_MCAST, bat_priv,

		   "Changing multicast flags from '%s' to '[%c%c%c]'\n",

		   bat_priv->mcast.enabled ? str_old_flags : "<undefined>",

		   old_enabled ? str_old_flags : "<undefined>",

		   (flags & BATADV_MCAST_WANT_ALL_UNSNOOPABLES) ? 'U' : '.',

		   (flags & BATADV_MCAST_WANT_ALL_IPV4) ? '4' : '.',

		   (flags & BATADV_MCAST_WANT_ALL_IPV6) ? '6' : '.');

}



/**

 * batadv_mcast_mla_tvlv_update() - update multicast tvlv

 * batadv_mcast_mla_flags_update() - update multicast flags

 * @bat_priv: the bat priv with all the soft interface information

 * @flags: flags indicating the new multicast state

 *

 * Updates the own multicast tvlv with our current multicast related settings,

 * capabilities and inabilities.

 *

 * Return: false if we want all IPv4 && IPv6 multicast traffic and true

 * otherwise.

 */

static bool batadv_mcast_mla_tvlv_update(struct batadv_priv *bat_priv)

static void

batadv_mcast_mla_flags_update(struct batadv_priv *bat_priv,

			      struct batadv_mcast_mla_flags *flags)

{

	struct batadv_tvlv_mcast_data mcast_data;

	struct batadv_mcast_querier_state querier4 = {false, false};

	struct batadv_mcast_querier_state querier6 = {false, false};

	struct net_device *dev = bat_priv->soft_iface;

	bool bridged;



	mcast_data.flags = BATADV_NO_FLAGS;

	memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));



	bridged = batadv_mcast_has_bridge(bat_priv);

	if (!bridged)

		goto update;



	if (!IS_ENABLED(CONFIG_BRIDGE_IGMP_SNOOPING))

		pr_warn_once("No bridge IGMP snooping compiled - multicast optimizations disabled\n");



	querier4.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IP);

	querier4.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IP);



	querier6.exists = br_multicast_has_querier_anywhere(dev, ETH_P_IPV6);

	querier6.shadowing = br_multicast_has_querier_adjacent(dev, ETH_P_IPV6);



	mcast_data.flags |= BATADV_MCAST_WANT_ALL_UNSNOOPABLES;



	/* 1) If no querier exists at all, then multicast listeners on

	 *    our local TT clients behind the bridge will keep silent.

	 * 2) If the selected querier is on one of our local TT clients,

	 *    behind the bridge, then this querier might shadow multicast

	 *    listeners on our local TT clients, behind this bridge.

	 *

	 * In both cases, we will signalize other batman nodes that

	 * we need all multicast traffic of the according protocol.

	 */

	if (!querier4.exists || querier4.shadowing)

		mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV4;



	if (!querier6.exists || querier6.shadowing)

		mcast_data.flags |= BATADV_MCAST_WANT_ALL_IPV6;



update:

	batadv_mcast_bridge_log(bat_priv, bridged, &querier4, &querier6);



	bat_priv->mcast.querier_ipv4.exists = querier4.exists;

	bat_priv->mcast.querier_ipv4.shadowing = querier4.shadowing;

	if (!memcmp(flags, &bat_priv->mcast.mla_flags, sizeof(*flags)))

		return;



	bat_priv->mcast.querier_ipv6.exists = querier6.exists;

	bat_priv->mcast.querier_ipv6.shadowing = querier6.shadowing;

	batadv_mcast_bridge_log(bat_priv, flags);

	batadv_mcast_flags_log(bat_priv, flags->tvlv_flags);



	bat_priv->mcast.bridged = bridged;

	mcast_data.flags = flags->tvlv_flags;

	memset(mcast_data.reserved, 0, sizeof(mcast_data.reserved));



	if (!bat_priv->mcast.enabled ||

	    mcast_data.flags != bat_priv->mcast.flags) {

		batadv_mcast_flags_log(bat_priv, mcast_data.flags);

	batadv_tvlv_container_register(bat_priv, BATADV_TVLV_MCAST, 2,

				       &mcast_data, sizeof(mcast_data));

		bat_priv->mcast.flags = mcast_data.flags;

		bat_priv->mcast.enabled = true;

	}



	return !(mcast_data.flags & BATADV_MCAST_WANT_ALL_IPV4 &&

		 mcast_data.flags & BATADV_MCAST_WANT_ALL_IPV6);

	bat_priv->mcast.mla_flags = *flags;

}



/**
@@ -599,22 +607,24 @@ static void __batadv_mcast_mla_update(struct batadv_priv *bat_priv) 
{

	struct net_device *soft_iface = bat_priv->soft_iface;

	struct hlist_head mcast_list = HLIST_HEAD_INIT;

	struct batadv_mcast_mla_flags flags;

	int ret;



	if (!batadv_mcast_mla_tvlv_update(bat_priv))

		goto update;

	flags = batadv_mcast_mla_flags_get(bat_priv);



	ret = batadv_mcast_mla_softif_get(bat_priv, soft_iface, &mcast_list);

	ret = batadv_mcast_mla_softif_get(soft_iface, &mcast_list, &flags);

	if (ret < 0)

		goto out;



	ret = batadv_mcast_mla_bridge_get(bat_priv, soft_iface, &mcast_list);

	ret = batadv_mcast_mla_bridge_get(soft_iface, &mcast_list, &flags);

	if (ret < 0)

		goto out;



update:

	spin_lock(&bat_priv->mcast.mla_lock);

	batadv_mcast_mla_tt_retract(bat_priv, &mcast_list);

	batadv_mcast_mla_tt_add(bat_priv, &mcast_list);

	batadv_mcast_mla_flags_update(bat_priv, &flags);

	spin_unlock(&bat_priv->mcast.mla_lock);



out:

	batadv_mcast_mla_list_free(&mcast_list);
@@ -639,10 +649,7 @@ static void batadv_mcast_mla_update(struct work_struct *work) 
	priv_mcast = container_of(delayed_work, struct batadv_priv_mcast, work);

	bat_priv = container_of(priv_mcast, struct batadv_priv, mcast);



	spin_lock(&bat_priv->mcast.mla_lock);

	__batadv_mcast_mla_update(bat_priv);

	spin_unlock(&bat_priv->mcast.mla_lock);



	batadv_mcast_start_timer(bat_priv);

}
@@ -1417,15 +1424,16 @@ void batadv_mcast_init(struct batadv_priv *bat_priv) 
static void batadv_mcast_flags_print_header(struct batadv_priv *bat_priv,

					    struct seq_file *seq)

{

	u8 flags = bat_priv->mcast.flags;

	struct batadv_mcast_mla_flags *mla_flags = &bat_priv->mcast.mla_flags;

	char querier4, querier6, shadowing4, shadowing6;

	bool bridged = bat_priv->mcast.bridged;

	bool bridged = mla_flags->bridged;

	u8 flags = mla_flags->tvlv_flags;



	if (bridged) {

		querier4 = bat_priv->mcast.querier_ipv4.exists ? '.' : '4';

		querier6 = bat_priv->mcast.querier_ipv6.exists ? '.' : '6';

		shadowing4 = bat_priv->mcast.querier_ipv4.shadowing ? '4' : '.';

		shadowing6 = bat_priv->mcast.querier_ipv6.shadowing ? '6' : '.';

		querier4 = mla_flags->querier_ipv4.exists ? '.' : '4';

		querier6 = mla_flags->querier_ipv6.exists ? '.' : '6';

		shadowing4 = mla_flags->querier_ipv4.shadowing ? '4' : '.';

		shadowing6 = mla_flags->querier_ipv6.shadowing ? '6' : '.';

	} else {

		querier4 = '?';

		querier6 = '?';
@@ -1517,19 +1525,19 @@ int batadv_mcast_flags_seq_print_text(struct seq_file *seq, void *offset) 
int batadv_mcast_mesh_info_put(struct sk_buff *msg,

			       struct batadv_priv *bat_priv)

{

	u32 flags = bat_priv->mcast.flags;

	u32 flags = bat_priv->mcast.mla_flags.tvlv_flags;

	u32 flags_priv = BATADV_NO_FLAGS;



	if (bat_priv->mcast.bridged) {

	if (bat_priv->mcast.mla_flags.bridged) {

		flags_priv |= BATADV_MCAST_FLAGS_BRIDGED;



		if (bat_priv->mcast.querier_ipv4.exists)

		if (bat_priv->mcast.mla_flags.querier_ipv4.exists)

			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_EXISTS;

		if (bat_priv->mcast.querier_ipv6.exists)

		if (bat_priv->mcast.mla_flags.querier_ipv6.exists)

			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_EXISTS;

		if (bat_priv->mcast.querier_ipv4.shadowing)

		if (bat_priv->mcast.mla_flags.querier_ipv4.shadowing)

			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV4_SHADOWING;

		if (bat_priv->mcast.querier_ipv6.shadowing)

		if (bat_priv->mcast.mla_flags.querier_ipv6.shadowing)

			flags_priv |= BATADV_MCAST_FLAGS_QUERIER_IPV6_SHADOWING;

	}

net/batman-adv/soft-interface.c

+0 −5
Original line number Diff line number Diff line
@@ -804,11 +804,6 @@ static int batadv_softif_init_late(struct net_device *dev) 
	atomic_set(&bat_priv->distributed_arp_table, 1);

#endif

#ifdef CONFIG_BATMAN_ADV_MCAST

	bat_priv->mcast.querier_ipv4.exists = false;

	bat_priv->mcast.querier_ipv4.shadowing = false;

	bat_priv->mcast.querier_ipv6.exists = false;

	bat_priv->mcast.querier_ipv6.shadowing = false;

	bat_priv->mcast.flags = BATADV_NO_FLAGS;

	atomic_set(&bat_priv->multicast_mode, 1);

	atomic_set(&bat_priv->multicast_fanout, 16);

	atomic_set(&bat_priv->mcast.num_want_all_unsnoopables, 0);

net/batman-adv/types.h

+24 −14
Original line number Diff line number Diff line
@@ -1170,6 +1170,26 @@ struct batadv_mcast_querier_state { 
	unsigned char shadowing:1;

};



/**

 * struct batadv_mcast_mla_flags - flags for the querier, bridge and tvlv state

 */

struct batadv_mcast_mla_flags {

	/** @querier_ipv4: the current state of an IGMP querier in the mesh */

	struct batadv_mcast_querier_state querier_ipv4;



	/** @querier_ipv6: the current state of an MLD querier in the mesh */

	struct batadv_mcast_querier_state querier_ipv6;



	/** @enabled: whether the multicast tvlv is currently enabled */

	unsigned char enabled:1;



	/** @bridged: whether the soft interface has a bridge on top */

	unsigned char bridged:1;



	/** @tvlv_flags: the flags we have last sent in our mcast tvlv */

	u8 tvlv_flags;

};



/**

 * struct batadv_priv_mcast - per mesh interface mcast data

 */
@@ -1198,20 +1218,10 @@ struct batadv_priv_mcast { 
	 */

	struct hlist_head want_all_ipv6_list;



	/** @querier_ipv4: the current state of an IGMP querier in the mesh */

	struct batadv_mcast_querier_state querier_ipv4;



	/** @querier_ipv6: the current state of an MLD querier in the mesh */

	struct batadv_mcast_querier_state querier_ipv6;



	/** @flags: the flags we have last sent in our mcast tvlv */

	u8 flags;



	/** @enabled: whether the multicast tvlv is currently enabled */

	unsigned char enabled:1;



	/** @bridged: whether the soft interface has a bridge on top */

	unsigned char bridged:1;

	/**

	 * @mla_flags: flags for the querier, bridge and tvlv state

	 */

	struct batadv_mcast_mla_flags mla_flags;



	/**

	 * @mla_lock: a lock protecting mla_list and mla_flags

CRA Git | Maintained and supported by SUSTech CRA and CCSE