fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / net / netfilter / nf_conntrack_proto_tcp.c
index 6492ed6..693d189 100644 (file)
@@ -24,7 +24,6 @@
  * version 2.2
  */
 
-#include <linux/config.h>
 #include <linux/types.h>
 #include <linux/sched.h>
 #include <linux/timer.h>
@@ -43,7 +42,8 @@
 #include <linux/netfilter_ipv4.h>
 #include <linux/netfilter_ipv6.h>
 #include <net/netfilter/nf_conntrack.h>
-#include <net/netfilter/nf_conntrack_protocol.h>
+#include <net/netfilter/nf_conntrack_l4proto.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
 
 #if 0
 #define DEBUGP printk
@@ -58,19 +58,19 @@ static DEFINE_RWLOCK(tcp_lock);
 /* "Be conservative in what you do, 
     be liberal in what you accept from others." 
     If it's non-zero, we mark only out of window RST segments as INVALID. */
-int nf_ct_tcp_be_liberal = 0;
+int nf_ct_tcp_be_liberal __read_mostly = 0;
 
 /* When connection is picked up from the middle, how many packets are required
    to pass in each direction when we assume we are in sync - if any side uses
    window scaling, we lost the game. 
    If it is set to zero, we disable picking up already established 
    connections. */
-int nf_ct_tcp_loose = 3;
+int nf_ct_tcp_loose __read_mostly = 3;
 
 /* Max number of the retransmitted packets without receiving an (acceptable) 
    ACK from the destination. If this number is reached, a shorter timer 
    will be started. */
-int nf_ct_tcp_max_retrans = 3;
+int nf_ct_tcp_max_retrans __read_mostly = 3;
 
   /* FIXME: Examine ipfilter's timeouts and conntrack transitions more
      closely.  They're more complex. --RR */
@@ -93,22 +93,22 @@ static const char *tcp_conntrack_names[] = {
 #define HOURS * 60 MINS
 #define DAYS * 24 HOURS
 
-unsigned int nf_ct_tcp_timeout_syn_sent =      2 MINS;
-unsigned int nf_ct_tcp_timeout_syn_recv =     60 SECS;
-unsigned int nf_ct_tcp_timeout_established =   5 DAYS;
-unsigned int nf_ct_tcp_timeout_fin_wait =      2 MINS;
-unsigned int nf_ct_tcp_timeout_close_wait =   60 SECS;
-unsigned int nf_ct_tcp_timeout_last_ack =     30 SECS;
-unsigned int nf_ct_tcp_timeout_time_wait =     2 MINS;
-unsigned int nf_ct_tcp_timeout_close =        10 SECS;
+static unsigned int nf_ct_tcp_timeout_syn_sent __read_mostly =      2 MINS;
+static unsigned int nf_ct_tcp_timeout_syn_recv __read_mostly =     60 SECS;
+static unsigned int nf_ct_tcp_timeout_established __read_mostly =   5 DAYS;
+static unsigned int nf_ct_tcp_timeout_fin_wait __read_mostly =      2 MINS;
+static unsigned int nf_ct_tcp_timeout_close_wait __read_mostly =   60 SECS;
+static unsigned int nf_ct_tcp_timeout_last_ack __read_mostly =     30 SECS;
+static unsigned int nf_ct_tcp_timeout_time_wait __read_mostly =     2 MINS;
+static unsigned int nf_ct_tcp_timeout_close __read_mostly =        10 SECS;
 
 /* RFC1122 says the R2 limit should be at least 100 seconds.
    Linux uses 15 packets as limit, which corresponds 
    to ~13-30min depending on RTO. */
-unsigned int nf_ct_tcp_timeout_max_retrans =     5 MINS;
+static unsigned int nf_ct_tcp_timeout_max_retrans __read_mostly =   5 MINS;
  
-static unsigned int * tcp_timeouts[]
-= { NULL,                              /* TCP_CONNTRACK_NONE */
+static unsigned int * tcp_timeouts[] = {
+    NULL,                              /* TCP_CONNTRACK_NONE */
     &nf_ct_tcp_timeout_syn_sent,       /* TCP_CONNTRACK_SYN_SENT, */
     &nf_ct_tcp_timeout_syn_recv,       /* TCP_CONNTRACK_SYN_RECV, */
     &nf_ct_tcp_timeout_established,    /* TCP_CONNTRACK_ESTABLISHED, */
@@ -474,8 +474,8 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
 
        /* Fast path for timestamp-only option */
        if (length == TCPOLEN_TSTAMP_ALIGNED*4
-           && *(__u32 *)ptr ==
-               __constant_ntohl((TCPOPT_NOP << 24) 
+           && *(__be32 *)ptr ==
+               __constant_htonl((TCPOPT_NOP << 24)
                                 | (TCPOPT_NOP << 16)
                                 | (TCPOPT_TIMESTAMP << 8)
                                 | TCPOLEN_TIMESTAMP))
@@ -506,9 +506,7 @@ static void tcp_sack(const struct sk_buff *skb, unsigned int dataoff,
                                for (i = 0;
                                     i < (opsize - TCPOLEN_SACK_BASE);
                                     i += TCPOLEN_SACK_PERBLOCK) {
-                                       memcpy(&tmp, (__u32 *)(ptr + i) + 1,
-                                              sizeof(__u32));
-                                       tmp = ntohl(tmp);
+                                       tmp = ntohl(*((__be32 *)(ptr+i)+1));
 
                                        if (after(tmp, *sack))
                                                *sack = tmp;
@@ -689,13 +687,15 @@ static int tcp_in_window(struct ip_ct_tcp *state,
                        if (state->last_dir == dir
                            && state->last_seq == seq
                            && state->last_ack == ack
-                           && state->last_end == end)
+                           && state->last_end == end
+                           && state->last_win == win)
                                state->retrans++;
                        else {
                                state->last_dir = dir;
                                state->last_seq = seq;
                                state->last_ack = ack;
                                state->last_end = end;
+                               state->last_win = win;
                                state->retrans = 0;
                        }
                }
@@ -730,7 +730,7 @@ static int tcp_in_window(struct ip_ct_tcp *state,
        return res;
 }
 
-#ifdef CONFIG_IP_NF_NAT_NEEDED
+#ifdef CONFIG_NF_NAT_NEEDED
 /* Update sender->td_end after NAT successfully mangled the packet */
 /* Caller must linearize skb at tcp header. */
 void nf_conntrack_tcp_update(struct sk_buff *skb,
@@ -762,7 +762,7 @@ void nf_conntrack_tcp_update(struct sk_buff *skb,
                receiver->td_end, receiver->td_maxend, receiver->td_maxwin,
                receiver->td_scale);
 }
+EXPORT_SYMBOL_GPL(nf_conntrack_tcp_update);
 #endif
 
 #define        TH_FIN  0x01
@@ -778,8 +778,10 @@ void nf_conntrack_tcp_update(struct sk_buff *skb,
 static u8 tcp_valid_flags[(TH_FIN|TH_SYN|TH_RST|TH_PUSH|TH_ACK|TH_URG) + 1] =
 {
        [TH_SYN]                        = 1,
-       [TH_SYN|TH_ACK]                 = 1,
        [TH_SYN|TH_PUSH]                = 1,
+       [TH_SYN|TH_URG]                 = 1,
+       [TH_SYN|TH_PUSH|TH_URG]         = 1,
+       [TH_SYN|TH_ACK]                 = 1,
        [TH_SYN|TH_ACK|TH_PUSH]         = 1,
        [TH_RST]                        = 1,
        [TH_RST|TH_ACK]                 = 1,
@@ -799,8 +801,7 @@ static int tcp_error(struct sk_buff *skb,
                     unsigned int dataoff,
                     enum ip_conntrack_info *ctinfo,
                     int pf,
-                    unsigned int hooknum,
-                    int(*csum)(const struct sk_buff *,unsigned int))
+                    unsigned int hooknum)
 {
        struct tcphdr _tcph, *th;
        unsigned int tcplen = skb->len - dataoff;
@@ -825,14 +826,13 @@ static int tcp_error(struct sk_buff *skb,
   
        /* Checksum invalid? Ignore.
         * We skip checking packets on the outgoing path
-        * because the semantic of CHECKSUM_HW is different there 
-        * and moreover root might send raw packets.
+        * because the checksum is assumed to be correct.
         */
        /* FIXME: Source route IP option packets --RR */
-       if (((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) ||
-            (pf == PF_INET6 && hooknum  == NF_IP6_PRE_ROUTING))
-           && skb->ip_summed != CHECKSUM_UNNECESSARY
-           && csum(skb, dataoff)) {
+       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))
                        nf_log_packet(pf, 0, skb, NULL, NULL, NULL,
                                  "nf_ct_tcp: bad TCP checksum ");
@@ -851,44 +851,6 @@ static int tcp_error(struct sk_buff *skb,
        return NF_ACCEPT;
 }
 
-static int csum4(const struct sk_buff *skb, unsigned int dataoff)
-{
-       return csum_tcpudp_magic(skb->nh.iph->saddr, skb->nh.iph->daddr,
-                                skb->len - dataoff, IPPROTO_TCP,
-                                skb->ip_summed == CHECKSUM_HW ? skb->csum
-                                : skb_checksum(skb, dataoff,
-                                               skb->len - dataoff, 0));
-}
-
-static int csum6(const struct sk_buff *skb, unsigned int dataoff)
-{
-       return csum_ipv6_magic(&skb->nh.ipv6h->saddr, &skb->nh.ipv6h->daddr,
-                              skb->len - dataoff, IPPROTO_TCP,
-                              skb->ip_summed == CHECKSUM_HW
-                              ? csum_sub(skb->csum,
-                                         skb_checksum(skb, 0, dataoff, 0))
-                              : skb_checksum(skb, dataoff, skb->len - dataoff,
-                                             0));
-}
-
-static int tcp_error4(struct sk_buff *skb,
-                     unsigned int dataoff,
-                     enum ip_conntrack_info *ctinfo,
-                     int pf,
-                     unsigned int hooknum)
-{
-       return tcp_error(skb, dataoff, ctinfo, pf, hooknum, csum4);
-}
-
-static int tcp_error6(struct sk_buff *skb,
-                     unsigned int dataoff,
-                     enum ip_conntrack_info *ctinfo,
-                     int pf,
-                     unsigned int hooknum)
-{
-       return tcp_error(skb, dataoff, ctinfo, pf, hooknum, csum6);
-}
-
 /* Returns verdict for packet, or -1 for invalid. */
 static int tcp_packet(struct nf_conn *conntrack,
                      const struct sk_buff *skb,
@@ -1206,11 +1168,221 @@ static int nfattr_to_tcp(struct nfattr *cda[], struct nf_conn *ct)
        return 0;
 }
 #endif
-  
-struct nf_conntrack_protocol nf_conntrack_protocol_tcp4 =
+
+#ifdef CONFIG_SYSCTL
+static unsigned int tcp_sysctl_table_users;
+static struct ctl_table_header *tcp_sysctl_header;
+static struct ctl_table tcp_sysctl_table[] = {
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT,
+               .procname       = "nf_conntrack_tcp_timeout_syn_sent",
+               .data           = &nf_ct_tcp_timeout_syn_sent,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_SYN_RECV,
+               .procname       = "nf_conntrack_tcp_timeout_syn_recv",
+               .data           = &nf_ct_tcp_timeout_syn_recv,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED,
+               .procname       = "nf_conntrack_tcp_timeout_established",
+               .data           = &nf_ct_tcp_timeout_established,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_FIN_WAIT,
+               .procname       = "nf_conntrack_tcp_timeout_fin_wait",
+               .data           = &nf_ct_tcp_timeout_fin_wait,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_CLOSE_WAIT,
+               .procname       = "nf_conntrack_tcp_timeout_close_wait",
+               .data           = &nf_ct_tcp_timeout_close_wait,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_LAST_ACK,
+               .procname       = "nf_conntrack_tcp_timeout_last_ack",
+               .data           = &nf_ct_tcp_timeout_last_ack,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_TIME_WAIT,
+               .procname       = "nf_conntrack_tcp_timeout_time_wait",
+               .data           = &nf_ct_tcp_timeout_time_wait,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_CLOSE,
+               .procname       = "nf_conntrack_tcp_timeout_close",
+               .data           = &nf_ct_tcp_timeout_close,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_TIMEOUT_MAX_RETRANS,
+               .procname       = "nf_conntrack_tcp_timeout_max_retrans",
+               .data           = &nf_ct_tcp_timeout_max_retrans,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_LOOSE,
+               .procname       = "nf_conntrack_tcp_loose",
+               .data           = &nf_ct_tcp_loose,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_BE_LIBERAL,
+               .procname       = "nf_conntrack_tcp_be_liberal",
+               .data           = &nf_ct_tcp_be_liberal,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec,
+       },
+       {
+               .ctl_name       = NET_NF_CONNTRACK_TCP_MAX_RETRANS,
+               .procname       = "nf_conntrack_tcp_max_retrans",
+               .data           = &nf_ct_tcp_max_retrans,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec,
+       },
+       {
+               .ctl_name       = 0
+       }
+};
+
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+static struct ctl_table tcp_compat_sysctl_table[] = {
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT,
+               .procname       = "ip_conntrack_tcp_timeout_syn_sent",
+               .data           = &nf_ct_tcp_timeout_syn_sent,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_RECV,
+               .procname       = "ip_conntrack_tcp_timeout_syn_recv",
+               .data           = &nf_ct_tcp_timeout_syn_recv,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED,
+               .procname       = "ip_conntrack_tcp_timeout_established",
+               .data           = &nf_ct_tcp_timeout_established,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_FIN_WAIT,
+               .procname       = "ip_conntrack_tcp_timeout_fin_wait",
+               .data           = &nf_ct_tcp_timeout_fin_wait,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_CLOSE_WAIT,
+               .procname       = "ip_conntrack_tcp_timeout_close_wait",
+               .data           = &nf_ct_tcp_timeout_close_wait,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_LAST_ACK,
+               .procname       = "ip_conntrack_tcp_timeout_last_ack",
+               .data           = &nf_ct_tcp_timeout_last_ack,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_TIME_WAIT,
+               .procname       = "ip_conntrack_tcp_timeout_time_wait",
+               .data           = &nf_ct_tcp_timeout_time_wait,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_CLOSE,
+               .procname       = "ip_conntrack_tcp_timeout_close",
+               .data           = &nf_ct_tcp_timeout_close,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_MAX_RETRANS,
+               .procname       = "ip_conntrack_tcp_timeout_max_retrans",
+               .data           = &nf_ct_tcp_timeout_max_retrans,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_LOOSE,
+               .procname       = "ip_conntrack_tcp_loose",
+               .data           = &nf_ct_tcp_loose,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_BE_LIBERAL,
+               .procname       = "ip_conntrack_tcp_be_liberal",
+               .data           = &nf_ct_tcp_be_liberal,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec,
+       },
+       {
+               .ctl_name       = NET_IPV4_NF_CONNTRACK_TCP_MAX_RETRANS,
+               .procname       = "ip_conntrack_tcp_max_retrans",
+               .data           = &nf_ct_tcp_max_retrans,
+               .maxlen         = sizeof(unsigned int),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec,
+       },
+       {
+               .ctl_name       = 0
+       }
+};
+#endif /* CONFIG_NF_CONNTRACK_PROC_COMPAT */
+#endif /* CONFIG_SYSCTL */
+
+struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp4 =
 {
        .l3proto                = PF_INET,
-       .proto                  = IPPROTO_TCP,
+       .l4proto                = IPPROTO_TCP,
        .name                   = "tcp",
        .pkt_to_tuple           = tcp_pkt_to_tuple,
        .invert_tuple           = tcp_invert_tuple,
@@ -1218,7 +1390,7 @@ struct nf_conntrack_protocol nf_conntrack_protocol_tcp4 =
        .print_conntrack        = tcp_print_conntrack,
        .packet                 = tcp_packet,
        .new                    = tcp_new,
-       .error                  = tcp_error4,
+       .error                  = tcp_error,
 #if defined(CONFIG_NF_CT_NETLINK) || \
     defined(CONFIG_NF_CT_NETLINK_MODULE)
        .to_nfattr              = tcp_to_nfattr,
@@ -1226,12 +1398,21 @@ struct nf_conntrack_protocol nf_conntrack_protocol_tcp4 =
        .tuple_to_nfattr        = nf_ct_port_tuple_to_nfattr,
        .nfattr_to_tuple        = nf_ct_port_nfattr_to_tuple,
 #endif
+#ifdef CONFIG_SYSCTL
+       .ctl_table_users        = &tcp_sysctl_table_users,
+       .ctl_table_header       = &tcp_sysctl_header,
+       .ctl_table              = tcp_sysctl_table,
+#ifdef CONFIG_NF_CONNTRACK_PROC_COMPAT
+       .ctl_compat_table       = tcp_compat_sysctl_table,
+#endif
+#endif
 };
+EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp4);
 
-struct nf_conntrack_protocol nf_conntrack_protocol_tcp6 =
+struct nf_conntrack_l4proto nf_conntrack_l4proto_tcp6 =
 {
        .l3proto                = PF_INET6,
-       .proto                  = IPPROTO_TCP,
+       .l4proto                = IPPROTO_TCP,
        .name                   = "tcp",
        .pkt_to_tuple           = tcp_pkt_to_tuple,
        .invert_tuple           = tcp_invert_tuple,
@@ -1239,7 +1420,7 @@ struct nf_conntrack_protocol nf_conntrack_protocol_tcp6 =
        .print_conntrack        = tcp_print_conntrack,
        .packet                 = tcp_packet,
        .new                    = tcp_new,
-       .error                  = tcp_error6,
+       .error                  = tcp_error,
 #if defined(CONFIG_NF_CT_NETLINK) || \
     defined(CONFIG_NF_CT_NETLINK_MODULE)
        .to_nfattr              = tcp_to_nfattr,
@@ -1247,7 +1428,10 @@ struct nf_conntrack_protocol nf_conntrack_protocol_tcp6 =
        .tuple_to_nfattr        = nf_ct_port_tuple_to_nfattr,
        .nfattr_to_tuple        = nf_ct_port_nfattr_to_tuple,
 #endif
+#ifdef CONFIG_SYSCTL
+       .ctl_table_users        = &tcp_sysctl_table_users,
+       .ctl_table_header       = &tcp_sysctl_header,
+       .ctl_table              = tcp_sysctl_table,
+#endif
 };
-
-EXPORT_SYMBOL(nf_conntrack_protocol_tcp4);
-EXPORT_SYMBOL(nf_conntrack_protocol_tcp6);
+EXPORT_SYMBOL_GPL(nf_conntrack_l4proto_tcp6);