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From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netfilter-devel@vger.kernel.org
Cc: davem@davemloft.net, netdev@vger.kernel.org
Subject: [PATCH 02/33] netfilter: xt_TCPMSS: Get mtu only if clamp-mss-to-pmtu is specified
Date: Fri,  4 Oct 2013 10:32:47 +0200	[thread overview]
Message-ID: <1380875598-5250-3-git-send-email-pablo@netfilter.org> (raw)
In-Reply-To: <1380875598-5250-1-git-send-email-pablo@netfilter.org>

From: Gao feng <gaofeng@cn.fujitsu.com>

This patch refactors the code to skip tcpmss_reverse_mtu if no
clamp-mss-to-pmtu is specified.

Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_TCPMSS.c |   70 +++++++++++++++++++++++----------------------
 1 file changed, 36 insertions(+), 34 deletions(-)

diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c
index cd24290..62776de 100644
--- a/net/netfilter/xt_TCPMSS.c
+++ b/net/netfilter/xt_TCPMSS.c
@@ -43,10 +43,41 @@ optlen(const u_int8_t *opt, unsigned int offset)
 		return opt[offset+1];
 }
 
+static u_int32_t tcpmss_reverse_mtu(const struct sk_buff *skb,
+				    unsigned int family)
+{
+	struct flowi fl;
+	const struct nf_afinfo *ai;
+	struct rtable *rt = NULL;
+	u_int32_t mtu     = ~0U;
+
+	if (family == PF_INET) {
+		struct flowi4 *fl4 = &fl.u.ip4;
+		memset(fl4, 0, sizeof(*fl4));
+		fl4->daddr = ip_hdr(skb)->saddr;
+	} else {
+		struct flowi6 *fl6 = &fl.u.ip6;
+
+		memset(fl6, 0, sizeof(*fl6));
+		fl6->daddr = ipv6_hdr(skb)->saddr;
+	}
+	rcu_read_lock();
+	ai = nf_get_afinfo(family);
+	if (ai != NULL)
+		ai->route(&init_net, (struct dst_entry **)&rt, &fl, false);
+	rcu_read_unlock();
+
+	if (rt != NULL) {
+		mtu = dst_mtu(&rt->dst);
+		dst_release(&rt->dst);
+	}
+	return mtu;
+}
+
 static int
 tcpmss_mangle_packet(struct sk_buff *skb,
 		     const struct xt_action_param *par,
-		     unsigned int in_mtu,
+		     unsigned int family,
 		     unsigned int tcphoff,
 		     unsigned int minlen)
 {
@@ -76,6 +107,8 @@ tcpmss_mangle_packet(struct sk_buff *skb,
 		return -1;
 
 	if (info->mss == XT_TCPMSS_CLAMP_PMTU) {
+		unsigned int in_mtu = tcpmss_reverse_mtu(skb, family);
+
 		if (dst_mtu(skb_dst(skb)) <= minlen) {
 			net_err_ratelimited("unknown or invalid path-MTU (%u)\n",
 					    dst_mtu(skb_dst(skb)));
@@ -165,37 +198,6 @@ tcpmss_mangle_packet(struct sk_buff *skb,
 	return TCPOLEN_MSS;
 }
 
-static u_int32_t tcpmss_reverse_mtu(const struct sk_buff *skb,
-				    unsigned int family)
-{
-	struct flowi fl;
-	const struct nf_afinfo *ai;
-	struct rtable *rt = NULL;
-	u_int32_t mtu     = ~0U;
-
-	if (family == PF_INET) {
-		struct flowi4 *fl4 = &fl.u.ip4;
-		memset(fl4, 0, sizeof(*fl4));
-		fl4->daddr = ip_hdr(skb)->saddr;
-	} else {
-		struct flowi6 *fl6 = &fl.u.ip6;
-
-		memset(fl6, 0, sizeof(*fl6));
-		fl6->daddr = ipv6_hdr(skb)->saddr;
-	}
-	rcu_read_lock();
-	ai = nf_get_afinfo(family);
-	if (ai != NULL)
-		ai->route(&init_net, (struct dst_entry **)&rt, &fl, false);
-	rcu_read_unlock();
-
-	if (rt != NULL) {
-		mtu = dst_mtu(&rt->dst);
-		dst_release(&rt->dst);
-	}
-	return mtu;
-}
-
 static unsigned int
 tcpmss_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 {
@@ -204,7 +206,7 @@ tcpmss_tg4(struct sk_buff *skb, const struct xt_action_param *par)
 	int ret;
 
 	ret = tcpmss_mangle_packet(skb, par,
-				   tcpmss_reverse_mtu(skb, PF_INET),
+				   PF_INET,
 				   iph->ihl * 4,
 				   sizeof(*iph) + sizeof(struct tcphdr));
 	if (ret < 0)
@@ -233,7 +235,7 @@ tcpmss_tg6(struct sk_buff *skb, const struct xt_action_param *par)
 	if (tcphoff < 0)
 		return NF_DROP;
 	ret = tcpmss_mangle_packet(skb, par,
-				   tcpmss_reverse_mtu(skb, PF_INET6),
+				   PF_INET6,
 				   tcphoff,
 				   sizeof(*ipv6h) + sizeof(struct tcphdr));
 	if (ret < 0)
-- 
1.7.10.4


  parent reply	other threads:[~2013-10-04  8:34 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-04  8:32 [PATCH 00/33] Netfilter updates for net-next Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 01/33] netfilter: nf_ct_sip: extend RCU read lock in set_expected_rtp_rtcp() Pablo Neira Ayuso
2013-10-04  8:32 ` Pablo Neira Ayuso [this message]
2013-10-04  8:32 ` [PATCH 03/33] netfilter: xt_TCPMSS: lookup route from proper net namespace Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 04/33] netfilter: ipset: Don't call ip_nest_end needlessly in the error path Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 05/33] netfilter: ipset: Sparse warning about shadowed variable fixed Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 06/33] netfilter: ipset: Fix sparse warnings due to missing rcu annotations Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 07/33] netfilter: ipset: Rename simple macro names to avoid namespace issues Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 08/33] netfilter: ipset: Fix "may be used uninitialized" warnings Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 09/33] netfilter: ipset: Use fix sized type for timeout in the extension part Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 10/33] netfilter: ipset: Support package fragments for IPv4 protos without ports Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 11/33] netfilter: ipset: order matches and targets separatedly in xt_set.c Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 12/33] netfilter: ipset: Introduce new operation to get both setname and family Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 13/33] netfilter: ipset: Prepare ipset to support multiple networks for hash types Pablo Neira Ayuso
2013-10-04  8:32 ` [PATCH 14/33] netfilter: ipset: Rename extension offset ids to extension ids Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 15/33] netfilter: ipset: Move extension data to set structure Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 16/33] netfilter: ipset: Generalize extensions support Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 17/33] netfilter: ipset: Support extensions which need a per data destroy function Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 18/33] netfilter: ipset: list:set: make sure all elements are checked by the gc Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 19/33] netfilter: ipset: Kconfig: ipset needs NETFILTER_NETLINK Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 20/33] netfilter: ipset: Add hash:net,net module to kernel Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 21/33] netfilter: ipset: Support comments for ipset entries in the core Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 22/33] netfilter: ipset: Support comments in bitmap-type ipsets Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 23/33] netfilter: ipset: Support comments in the list-type ipset Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 24/33] netfilter: ipset: Support comments in hash-type ipsets Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 25/33] netfilter: ipset: Fix hash resizing with comments Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 26/33] netfilter: ipset: For set:list types, replaced elements must be zeroed out Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 27/33] netfilter: ipset: Use a common function at listing the extensions Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 28/33] netfiler: ipset: Add net namespace for ipset Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 29/33] netfilter: ipset: Add hash:net,port,net module to kernel Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 30/33] netfilter: nfnetlink_queue: use proper net namespace to allocate skb Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 31/33] netfilter: nfnetlink_log: use proper net " Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 32/33] netfilter: nf_ct_sip: consolidate NAT hook functions Pablo Neira Ayuso
2013-10-04  8:33 ` [PATCH 33/33] netfilter: cttimeout: allow to set/get default protocol timeouts Pablo Neira Ayuso
2013-10-04 17:59 ` [PATCH 00/33] Netfilter updates for net-next David Miller

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