Before transimitting a packet, the datapath checks that the packet
length is not greater than the MTU. It determines the length based on
the 'protocol' field in the skb. If 'protocol' is ETH_P_8021Q, it reduces
the packet length as stored in the 'len' field by four bytes, which
is the size of a VLAN tag header. Unfortunately, packets that arrived
from userspace were not having the 'protocol' field set, which would
cause MTU-sized packets to be dropped. This commit sets the 'protocol'
field appropriately.
Thanks to Ben Pfaff for the help diagnosing this issue.
NIC-17 and NIC-26
struct odp_flow_key key;
struct sk_buff *skb;
struct sw_flow_actions *actions;
struct odp_flow_key key;
struct sk_buff *skb;
struct sw_flow_actions *actions;
execute.length))
goto error_free_skb;
execute.length))
goto error_free_skb;
+ skb_reset_mac_header(skb);
+ eth = eth_hdr(skb);
+
+ /* Normally, setting the skb 'protocol' field would be handled by a
+ * call to eth_type_trans(), but it assumes there's a sending
+ * device, which we may not have. */
+ if (ntohs(eth->h_proto) >= 1536)
+ skb->protocol = eth->h_proto;
+ else
+ skb->protocol = htons(ETH_P_802_2);
+
flow_extract(skb, execute.in_port, &key);
err = execute_actions(dp, skb, &key, actions->actions,
actions->n_actions, GFP_KERNEL);
flow_extract(skb, execute.in_port, &key);
err = execute_actions(dp, skb, &key, actions->actions,
actions->n_actions, GFP_KERNEL);