__skb_get_poff() returns the offset to the payload as far as it could
be dissected. The main user is currently BPF, so that we can dynamically
truncate packets without needing to push actual payload to the user
space and instead can analyze headers only.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In skb_flow_dissect(), we perform a dissection of a skbuff. Since we're
doing the work here anyway, also store thoff for a later usage, e.g. in
the BPF filter.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for L2 GRE tunnels, so that RPS can be more effective.
Signed-off-by: Michael Dalton <mwdalton@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
__skb_tx_hash() and __skb_get_rxhash() are all for calculating hash
value based by some fields in skb, mostly used for selecting queues
by device drivers.
Meanwhile, net/core/dev.c is bloating.
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Introduce ipv6_addr_hash() helper doing a XOR on all bits
of an IPv6 address, with an optimized x86_64 version.
Use it in flow dissector, as suggested by Andrew McGregor,
to reduce hash collision probabilities in fq_codel (and other
users of flow dissector)
Use it in ip6_tunnel.c and use more bit shuffling, as suggested
by David Laight, as existing hash was ignoring most of them.
Use it in sunrpc and use more bit shuffling, using hash_32().
Use it in net/ipv6/addrconf.c, using hash_32() as well.
As a cleanup, use it in net/ipv4/tcp_metrics.c
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrew McGregor <andrewmcgr@gmail.com>
Cc: Dave Taht <dave.taht@gmail.com>
Cc: Tom Herbert <therbert@google.com>
Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The file net/core/flow_dissector.c seems to be missing
including linux/export.h.
Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Le lundi 28 novembre 2011 à 19:06 -0500, David Miller a écrit :
> From: Dimitris Michailidis <dm@chelsio.com>
> Date: Mon, 28 Nov 2011 08:25:39 -0800
>
> >> +bool skb_flow_dissect(const struct sk_buff *skb, struct flow_keys
> >> *flow)
> >> +{
> >> + int poff, nhoff = skb_network_offset(skb);
> >> + u8 ip_proto;
> >> + u16 proto = skb->protocol;
> >
> > __be16 instead of u16 for proto?
>
> I'll take care of this when I apply these patches.
( CC trimmed )
Thanks David !
Here is a small patch to use one 64bit load/store on x86_64 instead of
two 32bit load/stores.
[PATCH net-next] flow_dissector: use a 64bit load/store
gcc compiler is smart enough to use a single load/store if we
memcpy(dptr, sptr, 8) on x86_64, regardless of
CONFIG_CC_OPTIMIZE_FOR_SIZE
In IP header, daddr immediately follows saddr, this wont change in the
future. We only need to make sure our flow_keys (src,dst) fields wont
break the rule.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We use at least two flow dissectors in network stack, with known
limitations and code duplication.
Introduce skb_flow_dissect() to factorize this, highly inspired from
existing dissector from __skb_get_rxhash()
Note : We extensively use skb_header_pointer(), this permits us to not
touch skb at all.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
