[PATCH net 1/1] bonding: fix PACKET_ORIGDEV regression on bonding masters

[Michal Soltys <soltys@ziu.info>]

This patch reverts:

b89f04c61efe bonding: deliver link-local packets with skb->dev set to link that packets arrived on

And its subsequent fixups:

6a9e461f6fe4 bonding: pass link-local packets to bonding master also.
0f3b914c9cfc bonding: fix warning message

The intended functionality of the original patch (as explained by its
author) has been available in the kernel since v2.6.21-350-g80feaacb8a64
via PACKET_ORIGDEV socket option. The patch also broke that feature, as
it's now no longer possible to get the original incoming device. Quoting
the report:

> Unfortunately, this doesn't completely restore the previous
> functionality as PACKET_ORIGDEV is broken for the copy: the original
> interface is lost through the call to netif_rx(). A LLDP daemon
> listening to the master interface won't get the original interface like
> it was able to before 4.12.

The patch reverts to pre-b89f04c61efe state, so:

- both master and original (via PACKET_ORIGDEV) devices are available
  when listening on the master
- original device is available when listening directly on one of its
  slaves

Reported-by: Vincent Bernat <vincent@bernat.ch>
Signed-off-by: Michal Soltys <soltys@ziu.info>
---
 drivers/net/bonding/bond_main.c | 21 ---------------------
 1 file changed, 21 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index a9d597f28023..290235587a0e 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -1183,27 +1183,6 @@ static rx_handler_result_t bond_handle_frame(struct sk_buff **pskb)
 		}
 	}
 
-	/* Link-local multicast packets should be passed to the
-	 * stack on the link they arrive as well as pass them to the
-	 * bond-master device. These packets are mostly usable when
-	 * stack receives it with the link on which they arrive
-	 * (e.g. LLDP) they also must be available on master. Some of
-	 * the use cases include (but are not limited to): LLDP agents
-	 * that must be able to operate both on enslaved interfaces as
-	 * well as on bonds themselves; linux bridges that must be able
-	 * to process/pass BPDUs from attached bonds when any kind of
-	 * STP version is enabled on the network.
-	 */
-	if (is_link_local_ether_addr(eth_hdr(skb)->h_dest)) {
-		struct sk_buff *nskb = skb_clone(skb, GFP_ATOMIC);
-
-		if (nskb) {
-			nskb->dev = bond->dev;
-			nskb->queue_mapping = 0;
-			netif_rx(nskb);
-		}
-		return RX_HANDLER_PASS;
-	}
 	if (bond_should_deliver_exact_match(skb, slave, bond))
 		return RX_HANDLER_EXACT;
 
-- 
2.20.1