mctp: Allow local delivery to the null EID

[ Upstream commit 1f6c77ac9e ]

We may need to receive packets addressed to the null EID (==0), but
addressed to us at the physical layer.

This change adds a lookup for local routes when we see a packet
addressed to EID 0, and a local phys address.

Signed-off-by: Jeremy Kerr <jk@codeconstruct.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 5093bbfc10 ("mctp: perform route lookups under a RCU read-side lock")
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Jeremy Kerr
2021-09-29 15:26:06 +08:00
committed by Greg Kroah-Hartman
parent 29017ab1a5
commit db3f17e571

View File

@@ -480,6 +480,10 @@ static int mctp_alloc_local_tag(struct mctp_sock *msk,
int rc = -EAGAIN;
u8 tagbits;
/* for NULL destination EIDs, we may get a response from any peer */
if (daddr == MCTP_ADDR_NULL)
daddr = MCTP_ADDR_ANY;
/* be optimistic, alloc now */
key = mctp_key_alloc(msk, saddr, daddr, 0, GFP_KERNEL);
if (!key)
@@ -558,6 +562,20 @@ struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet,
return rt;
}
static struct mctp_route *mctp_route_lookup_null(struct net *net,
struct net_device *dev)
{
struct mctp_route *rt;
list_for_each_entry_rcu(rt, &net->mctp.routes, list) {
if (rt->dev->dev == dev && rt->type == RTN_LOCAL &&
refcount_inc_not_zero(&rt->refs))
return rt;
}
return NULL;
}
/* sends a skb to rt and releases the route. */
int mctp_do_route(struct mctp_route *rt, struct sk_buff *skb)
{
@@ -853,6 +871,11 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev,
rcu_read_unlock();
rt = mctp_route_lookup(net, cb->net, mh->dest);
/* NULL EID, but addressed to our physical address */
if (!rt && mh->dest == MCTP_ADDR_NULL && skb->pkt_type == PACKET_HOST)
rt = mctp_route_lookup_null(net, dev);
if (!rt)
goto err_drop;