[PATCH net-next 02/10] mctp: Allow local delivery to the null EID
From: Matt Johnston <matt@codeconstruct.com.au>
Date: 2021-09-29 07:26:55
Subsystem:
management component transport protocol (mctp), networking [general], the rest · Maintainers:
Jeremy Kerr, Matt Johnston, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Jeremy Kerr <jk@codeconstruct.com.au> 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> --- net/mctp/route.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+)
diff --git a/net/mctp/route.c b/net/mctp/route.c
index a953f83ed02b..224fd25b3678 100644
--- a/net/mctp/route.c
+++ b/net/mctp/route.c@@ -474,6 +474,10 @@ 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)
@@ -552,6 +556,20 @@ 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) {
@@ -849,6 +867,11 @@ static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev, cb->net = READ_ONCE(mdev->net); 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;
--
2.30.2