From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 13/20] netfilter: ip6t_REJECT: skip checksum verification for outgoing ipv6 packets
Date: Mon, 4 Nov 2013 22:50:35 +0100 [thread overview]
Message-ID: <1383601842-4570-14-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1383601842-4570-1-git-send-email-pablo@netfilter.org>
From: Stanislav Fomichev <stfomichev@yandex-team.ru>
Don't verify checksum for outgoing packets because checksum calculation
may be done by the device.
Without this patch:
$ ip6tables -I OUTPUT -p tcp --dport 80 -j REJECT --reject-with tcp-reset
$ time telnet ipv6.google.com 80
Trying 2a00:1450:4010:c03::67...
telnet: Unable to connect to remote host: Connection timed out
real 0m7.201s
user 0m0.000s
sys 0m0.000s
With the patch applied:
$ ip6tables -I OUTPUT -p tcp --dport 80 -j REJECT --reject-with tcp-reset
$ time telnet ipv6.google.com 80
Trying 2a00:1450:4010:c03::67...
telnet: Unable to connect to remote host: Connection refused
real 0m0.085s
user 0m0.000s
sys 0m0.000s
Signed-off-by: Stanislav Fomichev <stfomichev@yandex-team.ru>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/ipv6/netfilter/ip6t_REJECT.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/net/ipv6/netfilter/ip6t_REJECT.c b/net/ipv6/netfilter/ip6t_REJECT.c
index 56eef30..da00a2e 100644
--- a/net/ipv6/netfilter/ip6t_REJECT.c
+++ b/net/ipv6/netfilter/ip6t_REJECT.c
@@ -39,7 +39,7 @@ MODULE_DESCRIPTION("Xtables: packet \"rejection\" target for IPv6");
MODULE_LICENSE("GPL");
/* Send RST reply */
-static void send_reset(struct net *net, struct sk_buff *oldskb)
+static void send_reset(struct net *net, struct sk_buff *oldskb, int hook)
{
struct sk_buff *nskb;
struct tcphdr otcph, *tcph;
@@ -88,8 +88,7 @@ static void send_reset(struct net *net, struct sk_buff *oldskb)
}
/* Check checksum. */
- if (csum_ipv6_magic(&oip6h->saddr, &oip6h->daddr, otcplen, IPPROTO_TCP,
- skb_checksum(oldskb, tcphoff, otcplen, 0))) {
+ if (nf_ip6_checksum(oldskb, hook, tcphoff, IPPROTO_TCP)) {
pr_debug("TCP checksum is invalid\n");
return;
}
@@ -227,7 +226,7 @@ reject_tg6(struct sk_buff *skb, const struct xt_action_param *par)
/* Do nothing */
break;
case IP6T_TCP_RESET:
- send_reset(net, skb);
+ send_reset(net, skb, par->hooknum);
break;
default:
net_info_ratelimited("case %u not handled yet\n", reject->with);
--
1.7.10.4
next prev parent reply other threads:[~2013-11-04 21:50 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-04 21:50 [PATCH 00/20] Netfilter/IPVS updates for net-next Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 01/20] ipvs: fix the IPVS_CMD_ATTR_MAX definition Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 02/20] ipvs: avoid rcu_barrier during netns cleanup Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 03/20] ipvs: improved SH fallback strategy Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 04/20] netfilter: xt_socket: use sock_gen_put() Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 05/20] netfilter: ipt_CLUSTERIP: make proc directory per net namespace Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 06/20] netfilter: ipt_CLUSTERIP: make clusterip_list " Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 07/20] netfilter: ipt_CLUSTERIP: make clusterip_lock " Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 08/20] netfilter: ipt_CLUSTERIP: add parameter net in clusterip_config_find_get Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 09/20] netfilter: ipt_CLUSTERIP: create proc entry under proper ipt_CLUSTERIP directory Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 10/20] netfilter: ipt_CLUSTERIP: use proper net namespace to operate CLUSTERIP Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 11/20] netfilter: ipset: Use netlink callback dump args only Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 12/20] netfilter: ipset: The unnamed union initialization may lead to compilation error Pablo Neira Ayuso
2013-11-04 21:50 ` Pablo Neira Ayuso [this message]
2013-11-04 21:50 ` [PATCH 14/20] netfilter:ipset: Fix memory allocation for bitmap:port Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 15/20] netfilter: ipset: remove duplicate define Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 16/20] bridge: netfilter: orphan skb before invoking ip netfilter hooks Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 17/20] net: ipvs: sctp: add missing verdict assignments in sctp_conn_schedule Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 18/20] net: ipvs: sctp: do not recalc sctp csum when ports didn't change Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 19/20] netfilter: introduce nf_conn_acct structure Pablo Neira Ayuso
2013-11-04 21:50 ` [PATCH 20/20] netfilter: ctnetlink: account both directions in one step Pablo Neira Ayuso
2013-11-05 0:47 ` [PATCH 00/20] Netfilter/IPVS updates for net-next David Miller
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1383601842-4570-14-git-send-email-pablo@netfilter.org \
--to=pablo@netfilter.org \
--cc=davem@davemloft.net \
--cc=netdev@vger.kernel.org \
--cc=netfilter-devel@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).