* [PATCH 4/4] packet: Add pre-defragmentation support for ipv4 fanouts.
@ 2011-07-05 9:04 David Miller
2011-07-05 9:35 ` Victor Julien
0 siblings, 1 reply; 4+ messages in thread
From: David Miller @ 2011-07-05 9:04 UTC (permalink / raw)
To: victor; +Cc: netdev
The skb->rxhash cannot be properly computed if the
packet is a fragment. To alleviate this, allow the
AF_PACKET client to ask for defragmentation to be
done at demux time.
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/if_packet.h | 1 +
net/packet/af_packet.c | 50 +++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/include/linux/if_packet.h b/include/linux/if_packet.h
index 1efa1cb..84e684e 100644
--- a/include/linux/if_packet.h
+++ b/include/linux/if_packet.h
@@ -53,6 +53,7 @@ struct sockaddr_ll {
#define PACKET_FANOUT_HASH 0
#define PACKET_FANOUT_LB 1
+#define PACKET_FANOUT_FLAG_DEFRAG 0x8000
struct tpacket_stats {
unsigned int tp_packets;
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 696d19c..6f381ba 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -223,7 +223,7 @@ struct packet_fanout {
int num_members;
u16 id;
u8 type;
- u8 pad;
+ u8 defrag;
atomic_t rr_cur;
struct list_head list;
struct sock *arr[PACKET_FANOUT_MAX];
@@ -447,6 +447,41 @@ static struct sock *fanout_demux_lb(struct packet_fanout *f, struct sk_buff *skb
return f->arr[cur];
}
+static struct sk_buff *fanout_check_defrag(struct sk_buff *skb)
+{
+ const struct iphdr *iph;
+ u32 len;
+
+ if (skb->protocol != htons(ETH_P_IP))
+ return skb;
+
+ if (!pskb_may_pull(skb, sizeof(struct iphdr)))
+ return skb;
+
+ iph = ip_hdr(skb);
+ if (iph->ihl < 5 || iph->version != 4)
+ return skb;
+ if (!pskb_may_pull(skb, iph->ihl*4))
+ return skb;
+ iph = ip_hdr(skb);
+ len = ntohs(iph->tot_len);
+ if (skb->len < len || len < (iph->ihl * 4))
+ return skb;
+
+ if (ip_is_fragment(ip_hdr(skb))) {
+ skb = skb_clone(skb, GFP_ATOMIC);
+ if (skb) {
+ if (pskb_trim_rcsum(skb, len))
+ return skb;
+ memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
+ if (ip_defrag(skb, IP_DEFRAG_AF_PACKET))
+ return NULL;
+ skb->rxhash = 0;
+ }
+ }
+ return skb;
+}
+
static int packet_rcv_fanout_hash(struct sk_buff *skb, struct net_device *dev,
struct packet_type *pt, struct net_device *orig_dev)
{
@@ -459,6 +494,12 @@ static int packet_rcv_fanout_hash(struct sk_buff *skb, struct net_device *dev,
return 0;
}
+ if (f->defrag) {
+ skb = fanout_check_defrag(skb);
+ if (!skb)
+ return 0;
+ }
+
skb_get_rxhash(skb);
sk = fanout_demux_hash(f, skb);
@@ -515,10 +556,12 @@ static void __fanout_unlink(struct sock *sk, struct packet_sock *po)
spin_unlock(&f->lock);
}
-static int fanout_add(struct sock *sk, u16 id, u8 type)
+static int fanout_add(struct sock *sk, u16 id, u16 type_flags)
{
struct packet_sock *po = pkt_sk(sk);
struct packet_fanout *f, *match;
+ u8 type = type_flags & 0xff;
+ u8 defrag = (type_flags & PACKET_FANOUT_FLAG_DEFRAG) ? 1 : 0;
int err;
switch (type) {
@@ -544,12 +587,15 @@ static int fanout_add(struct sock *sk, u16 id, u8 type)
break;
}
}
+ if (match && match->defrag != defrag)
+ return -EINVAL;
if (!match) {
match = kzalloc(sizeof(*match), GFP_KERNEL);
if (match) {
write_pnet(&match->net, sock_net(sk));
match->id = id;
match->type = type;
+ match->defrag = defrag;
atomic_set(&match->rr_cur, 0);
INIT_LIST_HEAD(&match->list);
spin_lock_init(&match->lock);
--
1.7.5.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 4/4] packet: Add pre-defragmentation support for ipv4 fanouts.
2011-07-05 9:04 [PATCH 4/4] packet: Add pre-defragmentation support for ipv4 fanouts David Miller
@ 2011-07-05 9:35 ` Victor Julien
2011-07-05 10:06 ` David Miller
0 siblings, 1 reply; 4+ messages in thread
From: Victor Julien @ 2011-07-05 9:35 UTC (permalink / raw)
To: David Miller; +Cc: netdev
On 07/05/2011 11:04 AM, David Miller wrote:
>
> The skb->rxhash cannot be properly computed if the
> packet is a fragment. To alleviate this, allow the
> AF_PACKET client to ask for defragmentation to be
> done at demux time.
Does the same limitation exist for IPv6 packets? If I read the patch
correctly the defrag is only done for IPv4.
--
---------------------------------------------
Victor Julien
http://www.inliniac.net/
PGP: http://www.inliniac.net/victorjulien.asc
---------------------------------------------
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 4/4] packet: Add pre-defragmentation support for ipv4 fanouts.
2011-07-05 9:35 ` Victor Julien
@ 2011-07-05 10:06 ` David Miller
2011-07-05 10:11 ` Victor Julien
0 siblings, 1 reply; 4+ messages in thread
From: David Miller @ 2011-07-05 10:06 UTC (permalink / raw)
To: victor; +Cc: netdev
From: Victor Julien <victor@inliniac.net>
Date: Tue, 05 Jul 2011 11:35:41 +0200
> On 07/05/2011 11:04 AM, David Miller wrote:
>>
>> The skb->rxhash cannot be properly computed if the
>> packet is a fragment. To alleviate this, allow the
>> AF_PACKET client to ask for defragmentation to be
>> done at demux time.
>
> Does the same limitation exist for IPv6 packets?
Yes.
> If I read the patch correctly the defrag is only done for IPv4.
Right, one thing at a time :-)
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 4/4] packet: Add pre-defragmentation support for ipv4 fanouts.
2011-07-05 10:06 ` David Miller
@ 2011-07-05 10:11 ` Victor Julien
0 siblings, 0 replies; 4+ messages in thread
From: Victor Julien @ 2011-07-05 10:11 UTC (permalink / raw)
To: David Miller; +Cc: netdev
On 07/05/2011 12:06 PM, David Miller wrote:
>> If I read the patch correctly the defrag is only done for IPv4.
>
> Right, one thing at a time :-)
>
Cool, just checking :)
--
---------------------------------------------
Victor Julien
http://www.inliniac.net/
PGP: http://www.inliniac.net/victorjulien.asc
---------------------------------------------
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-07-05 10:11 UTC | newest]
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2011-07-05 9:04 [PATCH 4/4] packet: Add pre-defragmentation support for ipv4 fanouts David Miller
2011-07-05 9:35 ` Victor Julien
2011-07-05 10:06 ` David Miller
2011-07-05 10:11 ` Victor Julien
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