From f38a9eb1f77b296ff07e000823884a0f64d67b2a Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Tue, 21 Jul 2015 10:43:56 +0200 Subject: dst: Metadata destinations Introduces a new dst_metadata which enables to carry per packet metadata between forwarding and processing elements via the skb->dst pointer. The structure is set up to be a union. Thus, each separate type of metadata requires its own dst instance. If demand arises to carry multiple types of metadata concurrently, metadata dst entries can be made stackable. The metadata dst entry is refcnt'ed as expected for now but a non reference counted use is possible if the reference is forced before queueing the skb. In order to allow allocating dsts with variable length, the existing dst_alloc() is split into a dst_alloc() and dst_init() function. The existing dst_init() function to initialize the subsystem is being renamed to dst_subsys_init() to make it clear what is what. The check before ip_route_input() is changed to ignore metadata dsts and drop the dst inside the routing function thus allowing to interpret metadata in a later commit. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- net/ipv4/ip_input.c | 3 ++- net/ipv4/route.c | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) (limited to 'net/ipv4') diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c index 2db4c8773c1b..f4fc8a77aaa7 100644 --- a/net/ipv4/ip_input.c +++ b/net/ipv4/ip_input.c @@ -146,6 +146,7 @@ #include #include #include +#include /* * Process Router Attention IP option (RFC 2113) @@ -331,7 +332,7 @@ static int ip_rcv_finish(struct sock *sk, struct sk_buff *skb) * Initialise the virtual path cache for the packet. It describes * how the packet travels inside Linux networking. */ - if (!skb_dst(skb)) { + if (!skb_valid_dst(skb)) { int err = ip_route_input_noref(skb, iph->daddr, iph->saddr, iph->tos, skb->dev); if (unlikely(err)) { diff --git a/net/ipv4/route.c b/net/ipv4/route.c index cd3157c464e6..4c8e84e75871 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1690,6 +1690,8 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, by fib_lookup. */ + skb_dst_drop(skb); + if (ipv4_is_multicast(saddr) || ipv4_is_lbcast(saddr)) goto martian_source; -- cgit v1.2.3-59-g8ed1b