[NETFILTER]: conntrack: add sysctl to disable checksumming

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter_ipv4/ip_conntrack.h

@@ -293,6 +293,7 @@ static inline int is_dying(struct ip_conntrack *ct)
 }
 
 extern unsigned int ip_conntrack_htable_size;
+extern int ip_conntrack_checksum;
  
 #define CONNTRACK_STAT_INC(count) (__get_cpu_var(ip_conntrack_stat).count++)
 

include/linux/sysctl.h

@@ -313,6 +313,7 @@ enum
 	NET_NF_CONNTRACK_FRAG6_TIMEOUT=29,
 	NET_NF_CONNTRACK_FRAG6_LOW_THRESH=30,
 	NET_NF_CONNTRACK_FRAG6_HIGH_THRESH=31,
+	NET_NF_CONNTRACK_CHECKSUM=32,
 };
 
 /* /proc/sys/net/ipv4 */
@@ -492,6 +493,7 @@ enum
  	NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_RECD=25,
  	NET_IPV4_NF_CONNTRACK_SCTP_TIMEOUT_SHUTDOWN_ACK_SENT=26,
 	NET_IPV4_NF_CONNTRACK_COUNT=27,
+	NET_IPV4_NF_CONNTRACK_CHECKSUM=28,
 };
  
 /* /proc/sys/net/ipv6 */

include/net/netfilter/nf_conntrack.h

@@ -285,6 +285,7 @@ static inline int nf_ct_is_dying(struct nf_conn *ct)
 }
 
 extern unsigned int nf_conntrack_htable_size;
+extern int nf_conntrack_checksum;
 
 #define NF_CT_STAT_INC(count) (__get_cpu_var(nf_conntrack_stat).count++)
 

net/ipv4/netfilter/ip_conntrack_proto_icmp.c

@@ -224,7 +224,7 @@ icmp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
 	}
 
 	/* See ip_conntrack_proto_tcp.c */
-	if (hooknum == NF_IP_PRE_ROUTING &&
+	if (ip_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
 	    nf_ip_checksum(skb, hooknum, skb->nh.iph->ihl * 4, 0)) {
 		if (LOG_INVALID(IPPROTO_ICMP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,

net/ipv4/netfilter/ip_conntrack_proto_tcp.c

@@ -870,7 +870,7 @@ static int tcp_error(struct sk_buff *skb,
 	 * and moreover root might send raw packets.
 	 */
 	/* FIXME: Source route IP option packets --RR */
-	if (hooknum == NF_IP_PRE_ROUTING &&
+	if (ip_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
 	    nf_ip_checksum(skb, hooknum, iph->ihl * 4, IPPROTO_TCP)) {
 		if (LOG_INVALID(IPPROTO_TCP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,

net/ipv4/netfilter/ip_conntrack_proto_udp.c

@@ -120,7 +120,7 @@ static int udp_error(struct sk_buff *skb, enum ip_conntrack_info *ctinfo,
 	 * because the semantic of CHECKSUM_HW is different there 
 	 * and moreover root might send raw packets.
 	 * FIXME: Source route IP option packets --RR */
-	if (hooknum == NF_IP_PRE_ROUTING &&
+	if (ip_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
 	    nf_ip_checksum(skb, hooknum, iph->ihl * 4, IPPROTO_UDP)) {
 		if (LOG_INVALID(IPPROTO_UDP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,

net/ipv4/netfilter/ip_conntrack_standalone.c

@@ -564,6 +564,8 @@ extern unsigned int ip_ct_generic_timeout;
 static int log_invalid_proto_min = 0;
 static int log_invalid_proto_max = 255;
 
+int ip_conntrack_checksum = 1;
+
 static struct ctl_table_header *ip_ct_sysctl_header;
 
 static ctl_table ip_ct_sysctl_table[] = {
@@ -591,6 +593,14 @@ static ctl_table ip_ct_sysctl_table[] = {
 		.mode		= 0444,
 		.proc_handler	= &proc_dointvec,
 	},
+	{
+		.ctl_name	= NET_IPV4_NF_CONNTRACK_CHECKSUM,
+		.procname	= "ip_conntrack_checksum",
+		.data		= &ip_conntrack_checksum,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
 	{
 		.ctl_name	= NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT,
 		.procname	= "ip_conntrack_tcp_timeout_syn_sent",
@@ -946,6 +956,7 @@ EXPORT_SYMBOL_GPL(__ip_conntrack_helper_find_byname);
 EXPORT_SYMBOL_GPL(ip_conntrack_proto_find_get);
 EXPORT_SYMBOL_GPL(ip_conntrack_proto_put);
 EXPORT_SYMBOL_GPL(__ip_conntrack_proto_find);
+EXPORT_SYMBOL_GPL(ip_conntrack_checksum);
 #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
     defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
 EXPORT_SYMBOL_GPL(ip_ct_port_tuple_to_nfattr);

net/ipv4/netfilter/nf_conntrack_proto_icmp.c

@@ -235,7 +235,7 @@ icmp_error(struct sk_buff *skb, unsigned int dataoff,
 	}
 
 	/* See ip_conntrack_proto_tcp.c */
-	if (hooknum == NF_IP_PRE_ROUTING &&
+	if (nf_conntrack_checksum && hooknum == NF_IP_PRE_ROUTING &&
 	    nf_ip_checksum(skb, hooknum, dataoff, 0)) {
 		if (LOG_INVALID(IPPROTO_ICMP))
 			nf_log_packet(PF_INET, 0, skb, NULL, NULL, NULL,

net/ipv6/netfilter/nf_conntrack_proto_icmpv6.c

@@ -233,7 +233,7 @@ icmpv6_error(struct sk_buff *skb, unsigned int dataoff,
 		return -NF_ACCEPT;
 	}
 
-	if (hooknum == NF_IP6_PRE_ROUTING &&
+	if (nf_conntrack_checksum && hooknum == NF_IP6_PRE_ROUTING &&
 	    nf_ip6_checksum(skb, hooknum, dataoff, IPPROTO_ICMPV6)) {
 		nf_log_packet(PF_INET6, 0, skb, NULL, NULL, NULL,
 			      "nf_ct_icmpv6: ICMPv6 checksum failed\n");

net/netfilter/nf_conntrack_proto_tcp.c

@@ -828,7 +828,8 @@ static int tcp_error(struct sk_buff *skb,
 	 * and moreover root might send raw packets.
 	 */
 	/* FIXME: Source route IP option packets --RR */
-	if (((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
+	if (nf_conntrack_checksum &&
+	    ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
 	     (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) &&
 	    nf_checksum(skb, hooknum, dataoff, IPPROTO_TCP, pf)) {
 		if (LOG_INVALID(IPPROTO_TCP))

net/netfilter/nf_conntrack_proto_udp.c

@@ -134,7 +134,8 @@ static int udp_error(struct sk_buff *skb, unsigned int dataoff,
 	 * because the semantic of CHECKSUM_HW is different there
 	 * and moreover root might send raw packets.
 	 * FIXME: Source route IP option packets --RR */
-	if (((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
+	if (nf_conntrack_checksum &&
+	    ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
 	     (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) &&
 	    nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) {
 		if (LOG_INVALID(IPPROTO_UDP))

net/netfilter/nf_conntrack_standalone.c

@@ -455,6 +455,8 @@ extern unsigned int nf_ct_generic_timeout;
 static int log_invalid_proto_min = 0;
 static int log_invalid_proto_max = 255;
 
+int nf_conntrack_checksum = 1;
+
 static struct ctl_table_header *nf_ct_sysctl_header;
 
 static ctl_table nf_ct_sysctl_table[] = {
@@ -482,6 +484,14 @@ static ctl_table nf_ct_sysctl_table[] = {
 		.mode           = 0444,
 		.proc_handler   = &proc_dointvec,
 	},
+	{
+		.ctl_name	= NET_NF_CONNTRACK_CHECKSUM,
+		.procname	= "nf_conntrack_checksum",
+		.data		= &nf_conntrack_checksum,
+		.maxlen		= sizeof(unsigned int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
 	{
 		.ctl_name	= NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT,
 		.procname	= "nf_conntrack_tcp_timeout_syn_sent",
@@ -851,6 +861,7 @@ EXPORT_SYMBOL(nf_ct_proto_put);
 EXPORT_SYMBOL(nf_ct_l3proto_find_get);
 EXPORT_SYMBOL(nf_ct_l3proto_put);
 EXPORT_SYMBOL(nf_ct_l3protos);
+EXPORT_SYMBOL_GPL(nf_conntrack_checksum);
 EXPORT_SYMBOL(nf_conntrack_expect_alloc);
 EXPORT_SYMBOL(nf_conntrack_expect_put);
 EXPORT_SYMBOL(nf_conntrack_expect_related);