Commit Graph

11 Commits

Author SHA1 Message Date
Eric Dumazet f4575d3534 flow_keys: n_proto type should be __be16
(struct flow_keys)->n_proto is in network order, use
proper type for this.

Fixes following sparse errors :

net/core/flow_dissector.c:139:39: warning: incorrect type in assignment (different base types)
net/core/flow_dissector.c:139:39:    expected unsigned short [unsigned] [usertype] n_proto
net/core/flow_dissector.c:139:39:    got restricted __be16 [assigned] [usertype] proto
net/core/flow_dissector.c:237:23: warning: incorrect type in assignment (different base types)
net/core/flow_dissector.c:237:23:    expected unsigned short [unsigned] [usertype] n_proto
net/core/flow_dissector.c:237:23:    got restricted __be16 [assigned] [usertype] proto

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: e0f31d8498 ("flow_keys: Record IP layer protocol in skb_flow_dissect()")
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-02-05 00:40:22 -08:00
Alexander Duyck 56193d1bce net: Add function for parsing the header length out of linear ethernet frames
This patch updates some of the flow_dissector api so that it can be used to
parse the length of ethernet buffers stored in fragments.  Most of the
changes needed were to __skb_get_poff as it needed to be updated to support
sending a linear buffer instead of a skb.

I have split __skb_get_poff into two functions, the first is skb_get_poff
and it retains the functionality of the original __skb_get_poff.  The other
function is __skb_get_poff which now works much like __skb_flow_dissect in
relation to skb_flow_dissect in that it provides the same functionality but
works with just a data buffer and hlen instead of needing an skb.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-09-05 17:47:02 -07:00
WANG Cong 453a940ea7 net: make skb an optional parameter for__skb_flow_dissect()
Fixes: commit 690e36e726 (net: Allow raw buffers to be passed into the flow dissector)
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-25 17:21:26 -07:00
David S. Miller 690e36e726 net: Allow raw buffers to be passed into the flow dissector.
Drivers, and perhaps other entities we have not yet considered,
sometimes want to know how deep the protocol headers go before
deciding how large of an SKB to allocate and how much of the packet to
place into the linear SKB area.

For example, consider a driver which has a device which DMAs into
pools of pages and then tells the driver where the data went in the
DMA descriptor(s).  The driver can then build an SKB and reference
most of the data via SKB fragments (which are page/offset/length
triplets).

However at least some of the front of the packet should be placed into
the linear SKB area, which comes before the fragments, so that packet
processing can get at the headers efficiently.  The first thing each
protocol layer is going to do is a "pskb_may_pull()" so we might as
well aggregate as much of this as possible while we're building the
SKB in the driver.

Part of supporting this is that we don't have an SKB yet, so we want
to be able to let the flow dissector operate on a raw buffer in order
to compute the offset of the end of the headers.

So now we have a __skb_flow_dissect() which takes an explicit data
pointer and length.

Signed-off-by: David S. Miller <davem@davemloft.net>
2014-08-23 12:13:41 -07:00
Tom Herbert 5ed20a68cd flow_dissector: Abstract out hash computation
Move the hash computation located in __skb_get_hash to be a separate
function which takes flow_keys as input. This will allow flow hash
computation in other contexts where we only have addresses and ports.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-07-07 21:14:20 -07:00
Govindarajulu Varadarajan e0f31d8498 flow_keys: Record IP layer protocol in skb_flow_dissect()
skb_flow_dissect() dissects only transport header type in ip_proto. It dose not
give any information about IPv4 or IPv6.

This patch adds new member, n_proto, to struct flow_keys. Which records the
IP layer type. i.e IPv4 or IPv6.

This can be used in netdev->ndo_rx_flow_steer driver function to dissect flow.

Adding new member to flow_keys increases the struct size by around 4 bytes.
This causes BUILD_BUG_ON(sizeof(qcb->data) < sz); to fail in
qdisc_cb_private_validate()

So increase data size by 4

Signed-off-by: Govindarajulu Varadarajan <_govind@gmx.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-06-23 14:32:19 -07:00
Nikolay Aleksandrov 357afe9c46 flow_dissector: factor out the ports extraction in skb_flow_get_ports
Factor out the code that extracts the ports from skb_flow_dissect and
add a new function skb_flow_get_ports which can be re-used.

Suggested-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-10-03 15:36:37 -04:00
Joe Perches 4787342c39 flow.h/flow_keys.h: Remove extern from function prototypes
There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-20 14:49:33 -04:00
Daniel Borkmann 8ed781668d flow_keys: include thoff into flow_keys for later usage
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>
2013-03-20 12:14:36 -04:00
Eric Dumazet 4d77d2b567 flow_dissector: use a 64bit load/store
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>
2011-11-29 13:17:03 -05:00
Eric Dumazet 0744dd00c1 net: introduce skb_flow_dissect()
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>
2011-11-28 19:09:07 -05:00