[PATCH net-next, v2] hyperv: Add handling of IP header with option field in netvsc_set_hash()

[Haiyang Zhang]

In case that the IP header has optional field at the end, this patch will
get the port numbers after that field, and compute the hash.

Signed-off-by: Haiyang Zhang <***@microsoft.com>
Reviewed-by: K. Y. Srinivasan <***@microsoft.com>
---
drivers/net/hyperv/netvsc_drv.c | 16 ++++++++++------
1 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 0fcb5e7..0d60c91 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -162,7 +162,7 @@ union sub_key {
* data: network byte order
* return: host byte order
*/
-static u32 comp_hash(u8 *key, int klen, u8 *data, int dlen)
+static u32 comp_hash(u8 *key, int klen, void *data, int dlen)
{
union sub_key subk;
int k_next = 4;
@@ -176,7 +176,7 @@ static u32 comp_hash(u8 *key, int klen, u8 *data, int dlen)
for (i = 0; i < dlen; i++) {
subk.kb = key[k_next];
k_next = (k_next + 1) % klen;
- dt = data[i];
+ dt = ((u8 *)data)[i];
for (j = 0; j < 8; j++) {
if (dt & 0x80)
ret ^= subk.ka;
@@ -191,6 +191,7 @@ static u32 comp_hash(u8 *key, int klen, u8 *data, int dlen)
static bool netvsc_set_hash(u32 *hash, struct sk_buff *skb)
{
struct iphdr *iphdr;
+ __be32 dbuf[3];
int data_len;
bool ret = false;

@@ -200,12 +201,15 @@ static bool netvsc_set_hash(u32 *hash, struct sk_buff *skb)
iphdr = ip_hdr(skb);

if (iphdr->version == 4) {
- if (iphdr->protocol == IPPROTO_TCP)
+ dbuf[0] = iphdr->saddr;
+ dbuf[1] = iphdr->daddr;
+ if (iphdr->protocol == IPPROTO_TCP) {
+ dbuf[2] = *(__be32 *)&tcp_hdr(skb)->source;
data_len = 12;
- else
+ } else {
data_len = 8;
- *hash = comp_hash(netvsc_hash_key, HASH_KEYLEN,
- (u8 *)&iphdr->saddr, data_len);
+ }
+ *hash = comp_hash(netvsc_hash_key, HASH_KEYLEN, dbuf, data_len);
ret = true;
}

[David Miller]

From: Haiyang Zhang <***@microsoft.com>
Date: Tue, 14 Oct 2014 15:16:28 -0700

Post by Haiyang Zhang
In case that the IP header has optional field at the end, this patch will
get the port numbers after that field, and compute the hash.

Instead of adding hack after hack after hack to your internal header
parser, just use the generic flow dissector we already have in the
kernel to fetch out the values you need.

__skb_flow_get_ports() etc.

[Haiyang Zhang]

-----Original Message-----
Sent: Tuesday, October 14, 2014 5:37 PM
To: Haiyang Zhang
Subject: Re: [PATCH net-next,v2] hyperv: Add handling of IP header with option
field in netvsc_set_hash()
Date: Tue, 14 Oct 2014 15:16:28 -0700

Post by Haiyang Zhang
In case that the IP header has optional field at the end, this patch
will get the port numbers after that field, and compute the hash.

Instead of adding hack after hack after hack to your internal header parser, just
use the generic flow dissector we already have in the kernel to fetch out the
values you need.
__skb_flow_get_ports() etc.

Thanks. I will update the patch.

- Haiyang

[Haiyang Zhang]

-----Original Message-----
Sent: Tuesday, October 14, 2014 4:05 PM
Subject: [PATCH net-next,v2] hyperv: Add handling of IP header with
option field in netvsc_set_hash()

This is a duplicate of a patch submitted earlier today. Please ignore.

[David Miller]

From: Haiyang Zhang <***@microsoft.com>
Date: Tue, 14 Oct 2014 20:05:17 +0000

Post by Haiyang Zhang
In case that the IP header has optional field at the end, this patch will
get the port numbers after that field, and compute the hash.

This isn't even close to what I asked for.

I said to remove all of this by-hand header parsing code in the
hyperv driver, and use the generic code networking facilities
that exist already to do this.