2010-04-11 12:16:06

by Herbert Xu

Subject: [PATCH 1/3] tcp: Handle CHECKSUM_PARTIAL for SYNACK packets for IPv4

tcp: Handle CHECKSUM_PARTIAL for SYNACK packets for IPv4

This patch moves the common code between tcp_v4_send_check and
tcp_v4_gso_send_check into a new function __tcp_v4_send_check.

It then uses the new function in tcp_v4_send_synack so that it
handles CHECKSUM_PARTIAL properly.

Signed-off-by: Herbert Xu <[email protected]>
---

net/ipv4/tcp_ipv4.c | 31 ++++++++++++++-----------------
1 file changed, 14 insertions(+), 17 deletions(-)

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 3c23e70..aebfd28 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -519,26 +519,31 @@ out:
sock_put(sk);
}

-/* This routine computes an IPv4 TCP checksum. */
-void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
+static void __tcp_v4_send_check(struct sk_buff *skb,
+ __be32 saddr, __be32 daddr)
{
- struct inet_sock *inet = inet_sk(sk);
struct tcphdr *th = tcp_hdr(skb);

if (skb->ip_summed == CHECKSUM_PARTIAL) {
- th->check = ~tcp_v4_check(len, inet->inet_saddr,
- inet->inet_daddr, 0);
+ th->check = ~tcp_v4_check(skb->len, saddr, daddr, 0);
skb->csum_start = skb_transport_header(skb) - skb->head;
skb->csum_offset = offsetof(struct tcphdr, check);
} else {
- th->check = tcp_v4_check(len, inet->inet_saddr,
- inet->inet_daddr,
+ th->check = tcp_v4_check(skb->len, saddr, daddr,
csum_partial(th,
th->doff << 2,
skb->csum));
}
}

+/* This routine computes an IPv4 TCP checksum. */
+void tcp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb)
+{
+ struct inet_sock *inet = inet_sk(sk);
+
+ __tcp_v4_send_check(skb, inet->inet_saddr, inet->inet_daddr);
+}
+
int tcp_v4_gso_send_check(struct sk_buff *skb)
{
const struct iphdr *iph;
@@ -551,10 +556,8 @@ int tcp_v4_gso_send_check(struct sk_buff *skb)
th = tcp_hdr(skb);

th->check = 0;
- th->check = ~tcp_v4_check(skb->len, iph->saddr, iph->daddr, 0);
- skb->csum_start = skb_transport_header(skb) - skb->head;
- skb->csum_offset = offsetof(struct tcphdr, check);
skb->ip_summed = CHECKSUM_PARTIAL;
+ __tcp_v4_send_check(skb, iph->saddr, iph->daddr);
return 0;
}

@@ -763,13 +766,7 @@ static int tcp_v4_send_synack(struct sock *sk, struct dst_entry *dst,
skb = tcp_make_synack(sk, dst, req, rvp);

if (skb) {
- struct tcphdr *th = tcp_hdr(skb);
-
- th->check = tcp_v4_check(skb->len,
- ireq->loc_addr,
- ireq->rmt_addr,
- csum_partial(th, skb->len,
- skb->csum));
+ __tcp_v4_send_check(skb, ireq->loc_addr, ireq->rmt_addr);

err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr,
ireq->rmt_addr,

2010-04-11 21:11:43

by Yinghai Lu

Subject: Re: [PATCH 1/3] tcp: Handle CHECKSUM_PARTIAL for SYNACK packets for IPv4

On 04/11/2010 05:15 AM, Herbert Xu wrote:
> tcp: Handle CHECKSUM_PARTIAL for SYNACK packets for IPv4
>
> This patch moves the common code between tcp_v4_send_check and
> tcp_v4_gso_send_check into a new function __tcp_v4_send_check.
>
> It then uses the new function in tcp_v4_send_synack so that it
> handles CHECKSUM_PARTIAL properly.
>
Good, three patches fix the problem.

Thanks

Yinghai

2010-04-11 22:00:05

by David Miller

Subject: Re: [PATCH 1/3] tcp: Handle CHECKSUM_PARTIAL for SYNACK packets for IPv4

From: Yinghai <[email protected]>
Date: Sun, 11 Apr 2010 14:07:40 -0700

> On 04/11/2010 05:15 AM, Herbert Xu wrote:
>> tcp: Handle CHECKSUM_PARTIAL for SYNACK packets for IPv4
>>
>> This patch moves the common code between tcp_v4_send_check and
>> tcp_v4_gso_send_check into a new function __tcp_v4_send_check.
>>
>> It then uses the new function in tcp_v4_send_synack so that it
>> handles CHECKSUM_PARTIAL properly.
>>
> Good, three patches fix the problem.

Thanks for testing.