1 files changed, 271 insertions, 138 deletions

diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c
index 7f8ade04e08e..0379b126865d 100644
--- a/net/batman-adv/send.c
+++ b/net/batman-adv/send.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-/* Copyright (C) 2007-2020  B.A.T.M.A.N. contributors:
+/* Copyright (C) B.A.T.M.A.N. contributors:
  *
  * Marek Lindner, Simon Wunderlich
  */
@@ -10,13 +10,13 @@
 #include <linux/atomic.h>
 #include <linux/bug.h>
 #include <linux/byteorder/generic.h>
+#include <linux/container_of.h>
 #include <linux/errno.h>
 #include <linux/etherdevice.h>
 #include <linux/gfp.h>
 #include <linux/if.h>
 #include <linux/if_ether.h>
 #include <linux/jiffies.h>
-#include <linux/kernel.h>
 #include <linux/kref.h>
 #include <linux/list.h>
 #include <linux/netdevice.h>
@@ -152,8 +152,7 @@ int batadv_send_unicast_skb(struct sk_buff *skb,
 	if (hardif_neigh && ret != NET_XMIT_DROP)
 		hardif_neigh->bat_v.last_unicast_tx = jiffies;
 
-	if (hardif_neigh)
-		batadv_hardif_neigh_put(hardif_neigh);
+	batadv_hardif_neigh_put(hardif_neigh);
 #endif
 
 	return ret;
@@ -309,8 +308,7 @@ bool batadv_send_skb_prepare_unicast_4addr(struct batadv_priv *bat_priv,
 
 	ret = true;
 out:
-	if (primary_if)
-		batadv_hardif_put(primary_if);
+	batadv_hardif_put(primary_if);
 	return ret;
 }
 
@@ -425,8 +423,7 @@ int batadv_send_skb_via_tt_generic(struct batadv_priv *bat_priv,
 	ret = batadv_send_skb_unicast(bat_priv, skb, packet_type,
 				      packet_subtype, orig_node, vid);
 
-	if (orig_node)
-		batadv_orig_node_put(orig_node);
+	batadv_orig_node_put(orig_node);
 
 	return ret;
 }
@@ -452,8 +449,7 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 	ret = batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST_4ADDR,
 				      BATADV_P_DATA, orig_node, vid);
 
-	if (orig_node)
-		batadv_orig_node_put(orig_node);
+	batadv_orig_node_put(orig_node);
 
 	return ret;
 }
@@ -461,7 +457,7 @@ int batadv_send_skb_via_gw(struct batadv_priv *bat_priv, struct sk_buff *skb,
 /**
  * batadv_forw_packet_free() - free a forwarding packet
  * @forw_packet: The packet to free
- * @dropped: whether the packet is freed because is is dropped
+ * @dropped: whether the packet is freed because is dropped
  *
  * This frees a forwarding packet and releases any resources it might
  * have claimed.
@@ -474,10 +470,8 @@ void batadv_forw_packet_free(struct batadv_forw_packet *forw_packet,
 	else
 		consume_skb(forw_packet->skb);
 
-	if (forw_packet->if_incoming)
-		batadv_hardif_put(forw_packet->if_incoming);
-	if (forw_packet->if_outgoing)
-		batadv_hardif_put(forw_packet->if_outgoing);
+	batadv_hardif_put(forw_packet->if_incoming);
+	batadv_hardif_put(forw_packet->if_outgoing);
 	if (forw_packet->queue_left)
 		atomic_inc(forw_packet->queue_left);
 	kfree(forw_packet);
@@ -605,8 +599,8 @@ bool batadv_forw_packet_steal(struct batadv_forw_packet *forw_packet,
  * given hard_iface. If hard_iface is NULL forwarding packets on all hard
  * interfaces will be claimed.
  *
- * The packets are being moved from the forw_list to the cleanup_list and
- * by that allows already running threads to notice the claiming.
+ * The packets are being moved from the forw_list to the cleanup_list. This
+ * makes it possible for already running threads to notice the claim.
  */
 static void
 batadv_forw_packet_list_steal(struct hlist_head *forw_list,
@@ -737,57 +731,52 @@ void batadv_forw_packet_ogmv1_queue(struct batadv_priv *bat_priv,
 }
 
 /**
- * batadv_add_bcast_packet_to_list() - queue broadcast packet for multiple sends
+ * batadv_forw_bcast_packet_to_list() - queue broadcast packet for transmissions
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: broadcast packet to add
  * @delay: number of jiffies to wait before sending
  * @own_packet: true if it is a self-generated broadcast packet
+ * @if_in: the interface where the packet was received on
+ * @if_out: the outgoing interface to queue on
  *
- * add a broadcast packet to the queue and setup timers. broadcast packets
+ * Adds a broadcast packet to the queue and sets up timers. Broadcast packets
  * are sent multiple times to increase probability for being received.
  *
- * The skb is not consumed, so the caller should make sure that the
- * skb is freed.
+ * This call clones the given skb, hence the caller needs to take into
+ * account that the data segment of the original skb might not be
+ * modifiable anymore.
  *
  * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
  */
-int batadv_add_bcast_packet_to_list(struct batadv_priv *bat_priv,
-				    const struct sk_buff *skb,
-				    unsigned long delay,
-				    bool own_packet)
+static int batadv_forw_bcast_packet_to_list(struct batadv_priv *bat_priv,
+					    struct sk_buff *skb,
+					    unsigned long delay,
+					    bool own_packet,
+					    struct batadv_hard_iface *if_in,
+					    struct batadv_hard_iface *if_out)
 {
-	struct batadv_hard_iface *primary_if;
 	struct batadv_forw_packet *forw_packet;
-	struct batadv_bcast_packet *bcast_packet;
+	unsigned long send_time = jiffies;
 	struct sk_buff *newskb;
 
-	primary_if = batadv_primary_if_get_selected(bat_priv);
-	if (!primary_if)
+	newskb = skb_clone(skb, GFP_ATOMIC);
+	if (!newskb)
 		goto err;
 
-	newskb = skb_copy(skb, GFP_ATOMIC);
-	if (!newskb) {
-		batadv_hardif_put(primary_if);
-		goto err;
-	}
-
-	forw_packet = batadv_forw_packet_alloc(primary_if, NULL,
+	forw_packet = batadv_forw_packet_alloc(if_in, if_out,
 					       &bat_priv->bcast_queue_left,
 					       bat_priv, newskb);
-	batadv_hardif_put(primary_if);
 	if (!forw_packet)
 		goto err_packet_free;
 
-	/* as we have a copy now, it is safe to decrease the TTL */
-	bcast_packet = (struct batadv_bcast_packet *)newskb->data;
-	bcast_packet->ttl--;
-
 	forw_packet->own = own_packet;
 
 	INIT_DELAYED_WORK(&forw_packet->delayed_work,
 			  batadv_send_outstanding_bcast_packet);
 
-	batadv_forw_packet_bcast_queue(bat_priv, forw_packet, jiffies + delay);
+	send_time += delay ? delay : msecs_to_jiffies(5);
+
+	batadv_forw_packet_bcast_queue(bat_priv, forw_packet, send_time);
 	return NETDEV_TX_OK;
 
 err_packet_free:
@@ -797,9 +786,222 @@ err:
 }
 
 /**
+ * batadv_forw_bcast_packet_if() - forward and queue a broadcast packet
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: broadcast packet to add
+ * @delay: number of jiffies to wait before sending
+ * @own_packet: true if it is a self-generated broadcast packet
+ * @if_in: the interface where the packet was received on
+ * @if_out: the outgoing interface to forward to
+ *
+ * Transmits a broadcast packet on the specified interface either immediately
+ * or if a delay is given after that. Furthermore, queues additional
+ * retransmissions if this interface is a wireless one.
+ *
+ * This call clones the given skb, hence the caller needs to take into
+ * account that the data segment of the original skb might not be
+ * modifiable anymore.
+ *
+ * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
+ */
+static int batadv_forw_bcast_packet_if(struct batadv_priv *bat_priv,
+				       struct sk_buff *skb,
+				       unsigned long delay,
+				       bool own_packet,
+				       struct batadv_hard_iface *if_in,
+				       struct batadv_hard_iface *if_out)
+{
+	unsigned int num_bcasts = if_out->num_bcasts;
+	struct sk_buff *newskb;
+	int ret = NETDEV_TX_OK;
+
+	if (!delay) {
+		newskb = skb_clone(skb, GFP_ATOMIC);
+		if (!newskb)
+			return NETDEV_TX_BUSY;
+
+		batadv_send_broadcast_skb(newskb, if_out);
+		num_bcasts--;
+	}
+
+	/* delayed broadcast or rebroadcasts? */
+	if (num_bcasts >= 1) {
+		BATADV_SKB_CB(skb)->num_bcasts = num_bcasts;
+
+		ret = batadv_forw_bcast_packet_to_list(bat_priv, skb, delay,
+						       own_packet, if_in,
+						       if_out);
+	}
+
+	return ret;
+}
+
+/**
+ * batadv_send_no_broadcast() - check whether (re)broadcast is necessary
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: broadcast packet to check
+ * @own_packet: true if it is a self-generated broadcast packet
+ * @if_out: the outgoing interface checked and considered for (re)broadcast
+ *
+ * Return: False if a packet needs to be (re)broadcasted on the given interface,
+ * true otherwise.
+ */
+static bool batadv_send_no_broadcast(struct batadv_priv *bat_priv,
+				     struct sk_buff *skb, bool own_packet,
+				     struct batadv_hard_iface *if_out)
+{
+	struct batadv_hardif_neigh_node *neigh_node = NULL;
+	struct batadv_bcast_packet *bcast_packet;
+	u8 *orig_neigh;
+	u8 *neigh_addr;
+	char *type;
+	int ret;
+
+	if (!own_packet) {
+		neigh_addr = eth_hdr(skb)->h_source;
+		neigh_node = batadv_hardif_neigh_get(if_out,
+						     neigh_addr);
+	}
+
+	bcast_packet = (struct batadv_bcast_packet *)skb->data;
+	orig_neigh = neigh_node ? neigh_node->orig : NULL;
+
+	ret = batadv_hardif_no_broadcast(if_out, bcast_packet->orig,
+					 orig_neigh);
+
+	batadv_hardif_neigh_put(neigh_node);
+
+	/* ok, may broadcast */
+	if (!ret)
+		return false;
+
+	/* no broadcast */
+	switch (ret) {
+	case BATADV_HARDIF_BCAST_NORECIPIENT:
+		type = "no neighbor";
+		break;
+	case BATADV_HARDIF_BCAST_DUPFWD:
+		type = "single neighbor is source";
+		break;
+	case BATADV_HARDIF_BCAST_DUPORIG:
+		type = "single neighbor is originator";
+		break;
+	default:
+		type = "unknown";
+	}
+
+	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+		   "BCAST packet from orig %pM on %s suppressed: %s\n",
+		   bcast_packet->orig,
+		   if_out->net_dev->name, type);
+
+	return true;
+}
+
+/**
+ * __batadv_forw_bcast_packet() - forward and queue a broadcast packet
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: broadcast packet to add
+ * @delay: number of jiffies to wait before sending
+ * @own_packet: true if it is a self-generated broadcast packet
+ *
+ * Transmits a broadcast packet either immediately or if a delay is given
+ * after that. Furthermore, queues additional retransmissions on wireless
+ * interfaces.
+ *
+ * This call clones the given skb, hence the caller needs to take into
+ * account that the data segment of the given skb might not be
+ * modifiable anymore.
+ *
+ * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
+ */
+static int __batadv_forw_bcast_packet(struct batadv_priv *bat_priv,
+				      struct sk_buff *skb,
+				      unsigned long delay,
+				      bool own_packet)
+{
+	struct batadv_hard_iface *hard_iface;
+	struct batadv_hard_iface *primary_if;
+	int ret = NETDEV_TX_OK;
+
+	primary_if = batadv_primary_if_get_selected(bat_priv);
+	if (!primary_if)
+		return NETDEV_TX_BUSY;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+		if (hard_iface->soft_iface != bat_priv->soft_iface)
+			continue;
+
+		if (!kref_get_unless_zero(&hard_iface->refcount))
+			continue;
+
+		if (batadv_send_no_broadcast(bat_priv, skb, own_packet,
+					     hard_iface)) {
+			batadv_hardif_put(hard_iface);
+			continue;
+		}
+
+		ret = batadv_forw_bcast_packet_if(bat_priv, skb, delay,
+						  own_packet, primary_if,
+						  hard_iface);
+		batadv_hardif_put(hard_iface);
+
+		if (ret == NETDEV_TX_BUSY)
+			break;
+	}
+	rcu_read_unlock();
+
+	batadv_hardif_put(primary_if);
+	return ret;
+}
+
+/**
+ * batadv_forw_bcast_packet() - forward and queue a broadcast packet
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: broadcast packet to add
+ * @delay: number of jiffies to wait before sending
+ * @own_packet: true if it is a self-generated broadcast packet
+ *
+ * Transmits a broadcast packet either immediately or if a delay is given
+ * after that. Furthermore, queues additional retransmissions on wireless
+ * interfaces.
+ *
+ * Return: NETDEV_TX_OK on success and NETDEV_TX_BUSY on errors.
+ */
+int batadv_forw_bcast_packet(struct batadv_priv *bat_priv,
+			     struct sk_buff *skb,
+			     unsigned long delay,
+			     bool own_packet)
+{
+	return __batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet);
+}
+
+/**
+ * batadv_send_bcast_packet() - send and queue a broadcast packet
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: broadcast packet to add
+ * @delay: number of jiffies to wait before sending
+ * @own_packet: true if it is a self-generated broadcast packet
+ *
+ * Transmits a broadcast packet either immediately or if a delay is given
+ * after that. Furthermore, queues additional retransmissions on wireless
+ * interfaces.
+ *
+ * Consumes the provided skb.
+ */
+void batadv_send_bcast_packet(struct batadv_priv *bat_priv,
+			      struct sk_buff *skb,
+			      unsigned long delay,
+			      bool own_packet)
+{
+	__batadv_forw_bcast_packet(bat_priv, skb, delay, own_packet);
+	consume_skb(skb);
+}
+
+/**
  * batadv_forw_packet_bcasts_left() - check if a retransmission is necessary
  * @forw_packet: the forwarding packet to check
- * @hard_iface: the interface to check on
  *
  * Checks whether a given packet has any (re)transmissions left on the provided
  * interface.
@@ -811,28 +1013,20 @@ err:
  * Return: True if (re)transmissions are left, false otherwise.
  */
 static bool
-batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet,
-			       struct batadv_hard_iface *hard_iface)
+batadv_forw_packet_bcasts_left(struct batadv_forw_packet *forw_packet)
 {
-	unsigned int max;
-
-	if (hard_iface)
-		max = hard_iface->num_bcasts;
-	else
-		max = BATADV_NUM_BCASTS_MAX;
-
-	return BATADV_SKB_CB(forw_packet->skb)->num_bcasts < max;
+	return BATADV_SKB_CB(forw_packet->skb)->num_bcasts;
 }
 
 /**
- * batadv_forw_packet_bcasts_inc() - increment retransmission counter of a
+ * batadv_forw_packet_bcasts_dec() - decrement retransmission counter of a
  *  packet
- * @forw_packet: the packet to increase the counter for
+ * @forw_packet: the packet to decrease the counter for
  */
 static void
-batadv_forw_packet_bcasts_inc(struct batadv_forw_packet *forw_packet)
+batadv_forw_packet_bcasts_dec(struct batadv_forw_packet *forw_packet)
 {
-	BATADV_SKB_CB(forw_packet->skb)->num_bcasts++;
+	BATADV_SKB_CB(forw_packet->skb)->num_bcasts--;
 }
 
 /**
@@ -843,30 +1037,30 @@ batadv_forw_packet_bcasts_inc(struct batadv_forw_packet *forw_packet)
  */
 bool batadv_forw_packet_is_rebroadcast(struct batadv_forw_packet *forw_packet)
 {
-	return BATADV_SKB_CB(forw_packet->skb)->num_bcasts > 0;
+	unsigned char num_bcasts = BATADV_SKB_CB(forw_packet->skb)->num_bcasts;
+
+	return num_bcasts != forw_packet->if_outgoing->num_bcasts;
 }
 
+/**
+ * batadv_send_outstanding_bcast_packet() - transmit a queued broadcast packet
+ * @work: work queue item
+ *
+ * Transmits a queued broadcast packet and if necessary reschedules it.
+ */
 static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 {
-	struct batadv_hard_iface *hard_iface;
-	struct batadv_hardif_neigh_node *neigh_node;
-	struct delayed_work *delayed_work;
+	unsigned long send_time = jiffies + msecs_to_jiffies(5);
 	struct batadv_forw_packet *forw_packet;
-	struct batadv_bcast_packet *bcast_packet;
-	struct sk_buff *skb1;
-	struct net_device *soft_iface;
+	struct delayed_work *delayed_work;
 	struct batadv_priv *bat_priv;
-	unsigned long send_time = jiffies + msecs_to_jiffies(5);
+	struct sk_buff *skb1;
 	bool dropped = false;
-	u8 *neigh_addr;
-	u8 *orig_neigh;
-	int ret = 0;
 
 	delayed_work = to_delayed_work(work);
 	forw_packet = container_of(delayed_work, struct batadv_forw_packet,
 				   delayed_work);
-	soft_iface = forw_packet->if_incoming->soft_iface;
-	bat_priv = netdev_priv(soft_iface);
+	bat_priv = netdev_priv(forw_packet->if_incoming->soft_iface);
 
 	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING) {
 		dropped = true;
@@ -878,76 +1072,15 @@ static void batadv_send_outstanding_bcast_packet(struct work_struct *work)
 		goto out;
 	}
 
-	bcast_packet = (struct batadv_bcast_packet *)forw_packet->skb->data;
-
-	/* rebroadcast packet */
-	rcu_read_lock();
-	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
-		if (hard_iface->soft_iface != soft_iface)
-			continue;
-
-		if (!batadv_forw_packet_bcasts_left(forw_packet, hard_iface))
-			continue;
-
-		if (forw_packet->own) {
-			neigh_node = NULL;
-		} else {
-			neigh_addr = eth_hdr(forw_packet->skb)->h_source;
-			neigh_node = batadv_hardif_neigh_get(hard_iface,
-							     neigh_addr);
-		}
-
-		orig_neigh = neigh_node ? neigh_node->orig : NULL;
-
-		ret = batadv_hardif_no_broadcast(hard_iface, bcast_packet->orig,
-						 orig_neigh);
-
-		if (ret) {
-			char *type;
-
-			switch (ret) {
-			case BATADV_HARDIF_BCAST_NORECIPIENT:
-				type = "no neighbor";
-				break;
-			case BATADV_HARDIF_BCAST_DUPFWD:
-				type = "single neighbor is source";
-				break;
-			case BATADV_HARDIF_BCAST_DUPORIG:
-				type = "single neighbor is originator";
-				break;
-			default:
-				type = "unknown";
-			}
-
-			batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "BCAST packet from orig %pM on %s suppressed: %s\n",
-				   bcast_packet->orig,
-				   hard_iface->net_dev->name, type);
-
-			if (neigh_node)
-				batadv_hardif_neigh_put(neigh_node);
-
-			continue;
-		}
-
-		if (neigh_node)
-			batadv_hardif_neigh_put(neigh_node);
-
-		if (!kref_get_unless_zero(&hard_iface->refcount))
-			continue;
-
-		/* send a copy of the saved skb */
-		skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
-		if (skb1)
-			batadv_send_broadcast_skb(skb1, hard_iface);
-
-		batadv_hardif_put(hard_iface);
-	}
-	rcu_read_unlock();
+	/* send a copy of the saved skb */
+	skb1 = skb_clone(forw_packet->skb, GFP_ATOMIC);
+	if (!skb1)
+		goto out;
 
-	batadv_forw_packet_bcasts_inc(forw_packet);
+	batadv_send_broadcast_skb(skb1, forw_packet->if_outgoing);
+	batadv_forw_packet_bcasts_dec(forw_packet);
 
-	/* if we still have some more bcasts to send */
-	if (batadv_forw_packet_bcasts_left(forw_packet, NULL)) {
+	if (batadv_forw_packet_bcasts_left(forw_packet)) {
 		batadv_forw_packet_bcast_queue(bat_priv, forw_packet,
 					       send_time);
 		return;