Merge tag 'batadv-net-for-davem-20200918' of git://git.open-mesh.org/linux-merge

Simon Wunderlich says:

====================
Here are some batman-adv bugfixes:

 - fix wrong type use in backbone_gw hash, by Linus Luessing

 - disable TT re-routing for multicast packets, by Linus Luessing

 - Add missing include for in_interrupt(), by Sven Eckelmann

 - fix BLA/multicast issues for packets sent via unicast,
   by Linus Luessing (3 patches)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

Author: davem330

net/batman-adv/bridge_loop_avoidance.c

@@ -25,6 +25,7 @@
 #include <linux/lockdep.h>
 #include <linux/netdevice.h>
 #include <linux/netlink.h>
+#include <linux/preempt.h>
 #include <linux/rculist.h>
 #include <linux/rcupdate.h>
 #include <linux/seq_file.h>
@@ -83,11 +84,12 @@ static inline u32 batadv_choose_claim(const void *data, u32 size)
  */
 static inline u32 batadv_choose_backbone_gw(const void *data, u32 size)
 {
-	const struct batadv_bla_claim *claim = (struct batadv_bla_claim *)data;
+	const struct batadv_bla_backbone_gw *gw;
 	u32 hash = 0;
 
-	hash = jhash(&claim->addr, sizeof(claim->addr), hash);
-	hash = jhash(&claim->vid, sizeof(claim->vid), hash);
+	gw = (struct batadv_bla_backbone_gw *)data;
+	hash = jhash(&gw->orig, sizeof(gw->orig), hash);
+	hash = jhash(&gw->vid, sizeof(gw->vid), hash);
 
 	return hash % size;
 }
@@ -1579,13 +1581,16 @@ int batadv_bla_init(struct batadv_priv *bat_priv)
 }
 
 /**
- * batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup.
+ * batadv_bla_check_duplist() - Check if a frame is in the broadcast dup.
  * @bat_priv: the bat priv with all the soft interface information
- * @skb: contains the bcast_packet to be checked
+ * @skb: contains the multicast packet to be checked
+ * @payload_ptr: pointer to position inside the head buffer of the skb
+ *  marking the start of the data to be CRC'ed
+ * @orig: originator mac address, NULL if unknown
  *
- * check if it is on our broadcast list. Another gateway might
- * have sent the same packet because it is connected to the same backbone,
- * so we have to remove this duplicate.
+ * Check if it is on our broadcast list. Another gateway might have sent the
+ * same packet because it is connected to the same backbone, so we have to
+ * remove this duplicate.
  *
  * This is performed by checking the CRC, which will tell us
  * with a good chance that it is the same packet. If it is furthermore
@@ -1594,19 +1599,17 @@ int batadv_bla_init(struct batadv_priv *bat_priv)
  *
  * Return: true if a packet is in the duplicate list, false otherwise.
  */
-bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
-				    struct sk_buff *skb)
+static bool batadv_bla_check_duplist(struct batadv_priv *bat_priv,
+				     struct sk_buff *skb, u8 *payload_ptr,
+				     const u8 *orig)
 {
-	int i, curr;
-	__be32 crc;
-	struct batadv_bcast_packet *bcast_packet;
 	struct batadv_bcast_duplist_entry *entry;
 	bool ret = false;
-
-	bcast_packet = (struct batadv_bcast_packet *)skb->data;
+	int i, curr;
+	__be32 crc;
 
 	/* calculate the crc ... */
-	crc = batadv_skb_crc32(skb, (u8 *)(bcast_packet + 1));
+	crc = batadv_skb_crc32(skb, payload_ptr);
 
 	spin_lock_bh(&bat_priv->bla.bcast_duplist_lock);
 
@@ -1625,8 +1628,21 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
 		if (entry->crc != crc)
 			continue;
 
-		if (batadv_compare_eth(entry->orig, bcast_packet->orig))
-			continue;
+		/* are the originators both known and not anonymous? */
+		if (orig && !is_zero_ether_addr(orig) &&
+		    !is_zero_ether_addr(entry->orig)) {
+			/* If known, check if the new frame came from
+			 * the same originator:
+			 * We are safe to take identical frames from the
+			 * same orig, if known, as multiplications in
+			 * the mesh are detected via the (orig, seqno) pair.
+			 * So we can be a bit more liberal here and allow
+			 * identical frames from the same orig which the source
+			 * host might have sent multiple times on purpose.
+			 */
+			if (batadv_compare_eth(entry->orig, orig))
+				continue;
+		}
 
 		/* this entry seems to match: same crc, not too old,
 		 * and from another gw. therefore return true to forbid it.
@@ -1642,7 +1658,14 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
 	entry = &bat_priv->bla.bcast_duplist[curr];
 	entry->crc = crc;
 	entry->entrytime = jiffies;
-	ether_addr_copy(entry->orig, bcast_packet->orig);
+
+	/* known originator */
+	if (orig)
+		ether_addr_copy(entry->orig, orig);
+	/* anonymous originator */
+	else
+		eth_zero_addr(entry->orig);
+
 	bat_priv->bla.bcast_duplist_curr = curr;
 
 out:
@@ -1651,6 +1674,48 @@ bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
 	return ret;
 }
 
+/**
+ * batadv_bla_check_ucast_duplist() - Check if a frame is in the broadcast dup.
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: contains the multicast packet to be checked, decapsulated from a
+ *  unicast_packet
+ *
+ * Check if it is on our broadcast list. Another gateway might have sent the
+ * same packet because it is connected to the same backbone, so we have to
+ * remove this duplicate.
+ *
+ * Return: true if a packet is in the duplicate list, false otherwise.
+ */
+static bool batadv_bla_check_ucast_duplist(struct batadv_priv *bat_priv,
+					   struct sk_buff *skb)
+{
+	return batadv_bla_check_duplist(bat_priv, skb, (u8 *)skb->data, NULL);
+}
+
+/**
+ * batadv_bla_check_bcast_duplist() - Check if a frame is in the broadcast dup.
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: contains the bcast_packet to be checked
+ *
+ * Check if it is on our broadcast list. Another gateway might have sent the
+ * same packet because it is connected to the same backbone, so we have to
+ * remove this duplicate.
+ *
+ * Return: true if a packet is in the duplicate list, false otherwise.
+ */
+bool batadv_bla_check_bcast_duplist(struct batadv_priv *bat_priv,
+				    struct sk_buff *skb)
+{
+	struct batadv_bcast_packet *bcast_packet;
+	u8 *payload_ptr;
+
+	bcast_packet = (struct batadv_bcast_packet *)skb->data;
+	payload_ptr = (u8 *)(bcast_packet + 1);
+
+	return batadv_bla_check_duplist(bat_priv, skb, payload_ptr,
+					bcast_packet->orig);
+}
+
 /**
  * batadv_bla_is_backbone_gw_orig() - Check if the originator is a gateway for
  *  the VLAN identified by vid.
@@ -1812,7 +1877,7 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb,
  * @bat_priv: the bat priv with all the soft interface information
  * @skb: the frame to be checked
  * @vid: the VLAN ID of the frame
- * @is_bcast: the packet came in a broadcast packet type.
+ * @packet_type: the batman packet type this frame came in
  *
  * batadv_bla_rx avoidance checks if:
  *  * we have to race for a claim
@@ -1824,7 +1889,7 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb,
  * further process the skb.
  */
 bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
-		   unsigned short vid, bool is_bcast)
+		   unsigned short vid, int packet_type)
 {
 	struct batadv_bla_backbone_gw *backbone_gw;
 	struct ethhdr *ethhdr;
@@ -1846,9 +1911,32 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
 		goto handled;
 
 	if (unlikely(atomic_read(&bat_priv->bla.num_requests)))
-		/* don't allow broadcasts while requests are in flight */
-		if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast)
-			goto handled;
+		/* don't allow multicast packets while requests are in flight */
+		if (is_multicast_ether_addr(ethhdr->h_dest))
+			/* Both broadcast flooding or multicast-via-unicasts
+			 * delivery might send to multiple backbone gateways
+			 * sharing the same LAN and therefore need to coordinate
+			 * which backbone gateway forwards into the LAN,
+			 * by claiming the payload source address.
+			 *
+			 * Broadcast flooding and multicast-via-unicasts
+			 * delivery use the following two batman packet types.
+			 * Note: explicitly exclude BATADV_UNICAST_4ADDR,
+			 * as the DHCP gateway feature will send explicitly
+			 * to only one BLA gateway, so the claiming process
+			 * should be avoided there.
+			 */
+			if (packet_type == BATADV_BCAST ||
+			    packet_type == BATADV_UNICAST)
+				goto handled;
+
+	/* potential duplicates from foreign BLA backbone gateways via
+	 * multicast-in-unicast packets
+	 */
+	if (is_multicast_ether_addr(ethhdr->h_dest) &&
+	    packet_type == BATADV_UNICAST &&
+	    batadv_bla_check_ucast_duplist(bat_priv, skb))
+		goto handled;
 
 	ether_addr_copy(search_claim.addr, ethhdr->h_source);
 	search_claim.vid = vid;
@@ -1883,13 +1971,14 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
 		goto allow;
 	}
 
-	/* if it is a broadcast ... */
-	if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) {
+	/* if it is a multicast ... */
+	if (is_multicast_ether_addr(ethhdr->h_dest) &&
+	    (packet_type == BATADV_BCAST || packet_type == BATADV_UNICAST)) {
 		/* ... drop it. the responsible gateway is in charge.
 		 *
-		 * We need to check is_bcast because with the gateway
+		 * We need to check packet type because with the gateway
 		 * feature, broadcasts (like DHCP requests) may be sent
-		 * using a unicast packet type.
+		 * using a unicast 4 address packet type. See comment above.
 		 */
 		goto handled;
 	} else {

net/batman-adv/bridge_loop_avoidance.h

@@ -35,7 +35,7 @@ static inline bool batadv_bla_is_loopdetect_mac(const uint8_t *mac)
 
 #ifdef CONFIG_BATMAN_ADV_BLA
 bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb,
-		   unsigned short vid, bool is_bcast);
+		   unsigned short vid, int packet_type);
 bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb,
 		   unsigned short vid);
 bool batadv_bla_is_backbone_gw(struct sk_buff *skb,
@@ -66,7 +66,7 @@ bool batadv_bla_check_claim(struct batadv_priv *bat_priv, u8 *addr,
 
 static inline bool batadv_bla_rx(struct batadv_priv *bat_priv,
 				 struct sk_buff *skb, unsigned short vid,
-				 bool is_bcast)
+				 int packet_type)
 {
 	return false;
 }

net/batman-adv/multicast.c

@@ -51,6 +51,7 @@
 #include <uapi/linux/batadv_packet.h>
 #include <uapi/linux/batman_adv.h>
 
+#include "bridge_loop_avoidance.h"
 #include "hard-interface.h"
 #include "hash.h"
 #include "log.h"
@@ -1434,6 +1435,35 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
 	return BATADV_FORW_ALL;
 }
 
+/**
+ * batadv_mcast_forw_send_orig() - send a multicast packet to an originator
+ * @bat_priv: the bat priv with all the soft interface information
+ * @skb: the multicast packet to send
+ * @vid: the vlan identifier
+ * @orig_node: the originator to send the packet to
+ *
+ * Return: NET_XMIT_DROP in case of error or NET_XMIT_SUCCESS otherwise.
+ */
+int batadv_mcast_forw_send_orig(struct batadv_priv *bat_priv,
+				struct sk_buff *skb,
+				unsigned short vid,
+				struct batadv_orig_node *orig_node)
+{
+	/* Avoid sending multicast-in-unicast packets to other BLA
+	 * gateways - they already got the frame from the LAN side
+	 * we share with them.
+	 * TODO: Refactor to take BLA into account earlier, to avoid
+	 * reducing the mcast_fanout count.
+	 */
+	if (batadv_bla_is_backbone_gw_orig(bat_priv, orig_node->orig, vid)) {
+		dev_kfree_skb(skb);
+		return NET_XMIT_SUCCESS;
+	}
+
+	return batadv_send_skb_unicast(bat_priv, skb, BATADV_UNICAST, 0,
+				       orig_node, vid);
+}
+
 /**
  * batadv_mcast_forw_tt() - forwards a packet to multicast listeners
  * @bat_priv: the bat priv with all the soft interface information
@@ -1471,8 +1501,8 @@ batadv_mcast_forw_tt(struct batadv_priv *bat_priv, struct sk_buff *skb,
 			break;
 		}
 
-		batadv_send_skb_unicast(bat_priv, newskb, BATADV_UNICAST, 0,
-					orig_entry->orig_node, vid);
+		batadv_mcast_forw_send_orig(bat_priv, newskb, vid,
+					    orig_entry->orig_node);
 	}
 	rcu_read_unlock();
 
@@ -1513,8 +1543,7 @@ batadv_mcast_forw_want_all_ipv4(struct batadv_priv *bat_priv,
 			break;
 		}
 
-		batadv_send_skb_unicast(bat_priv, newskb, BATADV_UNICAST, 0,
-					orig_node, vid);
+		batadv_mcast_forw_send_orig(bat_priv, newskb, vid, orig_node);
 	}
 	rcu_read_unlock();
 	return ret;
@@ -1551,8 +1580,7 @@ batadv_mcast_forw_want_all_ipv6(struct batadv_priv *bat_priv,
 			break;
 		}
 
-		batadv_send_skb_unicast(bat_priv, newskb, BATADV_UNICAST, 0,
-					orig_node, vid);
+		batadv_mcast_forw_send_orig(bat_priv, newskb, vid, orig_node);
 	}
 	rcu_read_unlock();
 	return ret;
@@ -1618,8 +1646,7 @@ batadv_mcast_forw_want_all_rtr4(struct batadv_priv *bat_priv,
 			break;
 		}
 
-		batadv_send_skb_unicast(bat_priv, newskb, BATADV_UNICAST, 0,
-					orig_node, vid);
+		batadv_mcast_forw_send_orig(bat_priv, newskb, vid, orig_node);
 	}
 	rcu_read_unlock();
 	return ret;
@@ -1656,8 +1683,7 @@ batadv_mcast_forw_want_all_rtr6(struct batadv_priv *bat_priv,
 			break;
 		}
 
-		batadv_send_skb_unicast(bat_priv, newskb, BATADV_UNICAST, 0,
-					orig_node, vid);
+		batadv_mcast_forw_send_orig(bat_priv, newskb, vid, orig_node);
 	}
 	rcu_read_unlock();
 	return ret;

net/batman-adv/multicast.h

@@ -46,6 +46,11 @@ enum batadv_forw_mode
 batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
 		       struct batadv_orig_node **mcast_single_orig);
 
+int batadv_mcast_forw_send_orig(struct batadv_priv *bat_priv,
+				struct sk_buff *skb,
+				unsigned short vid,
+				struct batadv_orig_node *orig_node);
+
 int batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb,
 			   unsigned short vid);
 
@@ -71,6 +76,16 @@ batadv_mcast_forw_mode(struct batadv_priv *bat_priv, struct sk_buff *skb,
 	return BATADV_FORW_ALL;
 }
 
+static inline int
+batadv_mcast_forw_send_orig(struct batadv_priv *bat_priv,
+			    struct sk_buff *skb,
+			    unsigned short vid,
+			    struct batadv_orig_node *orig_node)
+{
+	kfree_skb(skb);
+	return NET_XMIT_DROP;
+}
+
 static inline int
 batadv_mcast_forw_send(struct batadv_priv *bat_priv, struct sk_buff *skb,
 		       unsigned short vid)

net/batman-adv/routing.c

@@ -826,6 +826,10 @@ static bool batadv_check_unicast_ttvn(struct batadv_priv *bat_priv,
 	vid = batadv_get_vid(skb, hdr_len);
 	ethhdr = (struct ethhdr *)(skb->data + hdr_len);
 
+	/* do not reroute multicast frames in a unicast header */
+	if (is_multicast_ether_addr(ethhdr->h_dest))
+		return true;
+
 	/* check if the destination client was served by this node and it is now
 	 * roaming. In this case, it means that the node has got a ROAM_ADV
 	 * message and that it knows the new destination in the mesh to re-route