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/* This file contains all the functions required for the standalone

   ip_conntrack module.

   These are not required by the compatibility layer.

*/

/* (c) 1999 Paul `Rusty' Russell.  Licenced under the GNU General

   Public Licence. */

#include <linux/config.h>

#include <linux/types.h>

#include <linux/ip.h>

#include <linux/netfilter.h>

#include <linux/netfilter_ipv4.h>

#include <linux/module.h>

#include <linux/skbuff.h>

#include <linux/proc_fs.h>

#include <linux/version.h>

#include <linux/brlock.h>

#ifdef CONFIG_SYSCTL

#include <linux/sysctl.h>

#endif

#include <net/checksum.h>

#define ASSERT_READ_LOCK(x) MUST_BE_READ_LOCKED(&ip_conntrack_lock)

#define ASSERT_WRITE_LOCK(x) MUST_BE_WRITE_LOCKED(&ip_conntrack_lock)

#include <linux/netfilter_ipv4/ip_conntrack.h>

#include <linux/netfilter_ipv4/ip_conntrack_protocol.h>

#include <linux/netfilter_ipv4/ip_conntrack_core.h>

#include <linux/netfilter_ipv4/ip_conntrack_helper.h>

#include <linux/netfilter_ipv4/listhelp.h>

#if 0

#define DEBUGP printk

#else

#define DEBUGP(format, args...)

#endif

MODULE_LICENSE("GPL");

static int kill_proto(const struct ip_conntrack *i, void *data)

{

        return (i->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum ==

                        *((u_int8_t *) data));

}

static unsigned int

print_tuple(char *buffer, const struct ip_conntrack_tuple *tuple,

            struct ip_conntrack_protocol *proto)

{

        int len;

        len = sprintf(buffer, "src=%u.%u.%u.%u dst=%u.%u.%u.%u ",

                      NIPQUAD(tuple->src.ip), NIPQUAD(tuple->dst.ip));

        len += proto->print_tuple(buffer + len, tuple);

        return len;

}

/* FIXME: Don't print source proto part. --RR */

static unsigned int

print_expect(char *buffer, const struct ip_conntrack_expect *expect)

{

        unsigned int len;

        if (expect->expectant->helper->timeout)

                len = sprintf(buffer, "EXPECTING: %lu ",

                              timer_pending(&expect->timeout)

                              ? (expect->timeout.expires - jiffies)/HZ : 0);

        else

                len = sprintf(buffer, "EXPECTING: - ");

        len += sprintf(buffer + len, "use=%u proto=%u ",

                      atomic_read(&expect->use), expect->tuple.dst.protonum);

        len += print_tuple(buffer + len, &expect->tuple,

                           __ip_ct_find_proto(expect->tuple.dst.protonum));

        len += sprintf(buffer + len, "\n");

        return len;

}

static unsigned int

print_conntrack(char *buffer, struct ip_conntrack *conntrack)

{

        unsigned int len;

        struct ip_conntrack_protocol *proto

                = __ip_ct_find_proto(conntrack->tuplehash[IP_CT_DIR_ORIGINAL]

                               .tuple.dst.protonum);

        len = sprintf(buffer, "%-8s %u %lu ",

                      proto->name,

                      conntrack->tuplehash[IP_CT_DIR_ORIGINAL]

                      .tuple.dst.protonum,

                      timer_pending(&conntrack->timeout)

                      ? (conntrack->timeout.expires - jiffies)/HZ : 0);

        len += proto->print_conntrack(buffer + len, conntrack);

        len += print_tuple(buffer + len,

                           &conntrack->tuplehash[IP_CT_DIR_ORIGINAL].tuple,

                           proto);

        if (!(test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)))

                len += sprintf(buffer + len, "[UNREPLIED] ");

        len += print_tuple(buffer + len,

                           &conntrack->tuplehash[IP_CT_DIR_REPLY].tuple,

                           proto);

        if (test_bit(IPS_ASSURED_BIT, &conntrack->status))

                len += sprintf(buffer + len, "[ASSURED] ");

        len += sprintf(buffer + len, "use=%u ",

                       atomic_read(&conntrack->ct_general.use));

        len += sprintf(buffer + len, "\n");

        return len;

}

/* Returns true when finished. */

static inline int

conntrack_iterate(const struct ip_conntrack_tuple_hash *hash,

                  char *buffer, off_t offset, off_t *upto,

                  unsigned int *len, unsigned int maxlen)

{

        unsigned int newlen;

        IP_NF_ASSERT(hash->ctrack);

        MUST_BE_READ_LOCKED(&ip_conntrack_lock);

        /* Only count originals */

        if (DIRECTION(hash))

                return 0;

        if ((*upto)++ < offset)

                return 0;

        newlen = print_conntrack(buffer + *len, hash->ctrack);

        if (*len + newlen > maxlen)

                return 1;

        else *len += newlen;

        return 0;

}

static int

list_conntracks(char *buffer, char **start, off_t offset, int length)

{

        unsigned int i;

        unsigned int len = 0;

        off_t upto = 0;

        struct list_head *e;

        READ_LOCK(&ip_conntrack_lock);

        /* Traverse hash; print originals then reply. */

        for (i = 0; i < ip_conntrack_htable_size; i++) {

                if (LIST_FIND(&ip_conntrack_hash[i], conntrack_iterate,

                              struct ip_conntrack_tuple_hash *,

                              buffer, offset, &upto, &len, length))

                        goto finished;

        }

        /* Now iterate through expecteds. */

        for (e = ip_conntrack_expect_list.next;

             e != &ip_conntrack_expect_list; e = e->next) {

                unsigned int last_len;

                struct ip_conntrack_expect *expect

                        = (struct ip_conntrack_expect *)e;

                if (upto++ < offset) continue;

                last_len = len;

                len += print_expect(buffer + len, expect);

                if (len > length) {

                        len = last_len;

                        goto finished;

                }

        }

 finished:

        READ_UNLOCK(&ip_conntrack_lock);

        /* `start' hack - see fs/proc/generic.c line ~165 */

        *start = (char *)((unsigned int)upto - offset);

        return len;

}

static unsigned int ip_confirm(unsigned int hooknum,

                               struct sk_buff **pskb,

                               const struct net_device *in,

                               const struct net_device *out,

                               int (*okfn)(struct sk_buff *))

{

        /* We've seen it coming out the other side: confirm it */

        return ip_conntrack_confirm(*pskb);

}

static unsigned int ip_refrag(unsigned int hooknum,

                              struct sk_buff **pskb,

                              const struct net_device *in,

                              const struct net_device *out,

                              int (*okfn)(struct sk_buff *))

{

        struct rtable *rt = (struct rtable *)(*pskb)->dst;

        /* We've seen it coming out the other side: confirm */

        if (ip_confirm(hooknum, pskb, in, out, okfn) != NF_ACCEPT)

                return NF_DROP;

        /* Local packets are never produced too large for their

           interface.  We degfragment them at LOCAL_OUT, however,

           so we have to refragment them here. */

        if ((*pskb)->len > rt->u.dst.pmtu) {

                /* No hook can be after us, so this should be OK. */

                ip_fragment(*pskb, okfn);

                return NF_STOLEN;

        }

        return NF_ACCEPT;

}

static unsigned int ip_conntrack_local(unsigned int hooknum,

                                       struct sk_buff **pskb,

                                       const struct net_device *in,

                                       const struct net_device *out,

                                       int (*okfn)(struct sk_buff *))

{

        /* root is playing with raw sockets. */

        if ((*pskb)->len < sizeof(struct iphdr)

            || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {

                if (net_ratelimit())

                        printk("ipt_hook: happy cracking.\n");

                return NF_ACCEPT;

        }

        return ip_conntrack_in(hooknum, pskb, in, out, okfn);

}

/* Connection tracking may drop packets, but never alters them, so

   make it the first hook. */

static struct nf_hook_ops ip_conntrack_in_ops

= { { NULL, NULL }, ip_conntrack_in, PF_INET, NF_IP_PRE_ROUTING,

        NF_IP_PRI_CONNTRACK };

static struct nf_hook_ops ip_conntrack_local_out_ops

= { { NULL, NULL }, ip_conntrack_local, PF_INET, NF_IP_LOCAL_OUT,

        NF_IP_PRI_CONNTRACK };

/* Refragmenter; last chance. */

static struct nf_hook_ops ip_conntrack_out_ops

= { { NULL, NULL }, ip_refrag, PF_INET, NF_IP_POST_ROUTING, NF_IP_PRI_LAST };

static struct nf_hook_ops ip_conntrack_local_in_ops

= { { NULL, NULL }, ip_confirm, PF_INET, NF_IP_LOCAL_IN, NF_IP_PRI_LAST-1 };

/* Sysctl support */

#ifdef CONFIG_SYSCTL

/* From ip_conntrack_core.c */

extern int ip_conntrack_max;

extern unsigned int ip_conntrack_htable_size;

/* From ip_conntrack_proto_tcp.c */

extern unsigned long ip_ct_tcp_timeout_syn_sent;

extern unsigned long ip_ct_tcp_timeout_syn_recv;

extern unsigned long ip_ct_tcp_timeout_established;

extern unsigned long ip_ct_tcp_timeout_fin_wait;

extern unsigned long ip_ct_tcp_timeout_close_wait;

extern unsigned long ip_ct_tcp_timeout_last_ack;

extern unsigned long ip_ct_tcp_timeout_time_wait;

extern unsigned long ip_ct_tcp_timeout_close;

/* From ip_conntrack_proto_udp.c */

extern unsigned long ip_ct_udp_timeout;

extern unsigned long ip_ct_udp_timeout_stream;

/* From ip_conntrack_proto_icmp.c */

extern unsigned long ip_ct_icmp_timeout;

/* From ip_conntrack_proto_icmp.c */

extern unsigned long ip_ct_generic_timeout;

static struct ctl_table_header *ip_ct_sysctl_header;

static ctl_table ip_ct_sysctl_table[] = {

        {NET_IPV4_NF_CONNTRACK_MAX, "ip_conntrack_max",

         &ip_conntrack_max, sizeof(int), 0644, NULL,

         &proc_dointvec},

        {NET_IPV4_NF_CONNTRACK_BUCKETS, "ip_conntrack_buckets",

         &ip_conntrack_htable_size, sizeof(unsigned int), 0444, NULL,

         &proc_dointvec},

        {NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_SENT, "ip_conntrack_tcp_timeout_syn_sent",

         &ip_ct_tcp_timeout_syn_sent, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_SYN_RECV, "ip_conntrack_tcp_timeout_syn_recv",

         &ip_ct_tcp_timeout_syn_recv, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_ESTABLISHED, "ip_conntrack_tcp_timeout_established",

         &ip_ct_tcp_timeout_established, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_FIN_WAIT, "ip_conntrack_tcp_timeout_fin_wait",

         &ip_ct_tcp_timeout_fin_wait, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_CLOSE_WAIT, "ip_conntrack_tcp_timeout_close_wait",

         &ip_ct_tcp_timeout_close_wait, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_LAST_ACK, "ip_conntrack_tcp_timeout_last_ack",

         &ip_ct_tcp_timeout_last_ack, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_TIME_WAIT, "ip_conntrack_tcp_timeout_time_wait",

         &ip_ct_tcp_timeout_time_wait, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_TCP_TIMEOUT_CLOSE, "ip_conntrack_tcp_timeout_close",

         &ip_ct_tcp_timeout_close, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT, "ip_conntrack_udp_timeout",

         &ip_ct_udp_timeout, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_UDP_TIMEOUT_STREAM, "ip_conntrack_udp_timeout_stream",

         &ip_ct_udp_timeout_stream, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_ICMP_TIMEOUT, "ip_conntrack_icmp_timeout",

         &ip_ct_icmp_timeout, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {NET_IPV4_NF_CONNTRACK_GENERIC_TIMEOUT, "ip_conntrack_generic_timeout",

         &ip_ct_generic_timeout, sizeof(unsigned int), 0644, NULL,

         &proc_dointvec_jiffies},

        {0}

};

#define NET_IP_CONNTRACK_MAX 2089

static ctl_table ip_ct_netfilter_table[] = {

        {NET_IPV4_NETFILTER, "netfilter", NULL, 0, 0555, ip_ct_sysctl_table, 0, 0, 0, 0, 0},

        {NET_IP_CONNTRACK_MAX, "ip_conntrack_max",

         &ip_conntrack_max, sizeof(int), 0644, NULL,

         &proc_dointvec},

        {0}

};

static ctl_table ip_ct_ipv4_table[] = {

        {NET_IPV4, "ipv4", NULL, 0, 0555, ip_ct_netfilter_table, 0, 0, 0, 0, 0},

        {0}

};

static ctl_table ip_ct_net_table[] = {

        {CTL_NET, "net", NULL, 0, 0555, ip_ct_ipv4_table, 0, 0, 0, 0, 0},

        {0}

};

#endif

static int init_or_cleanup(int init)

{

        struct proc_dir_entry *proc;

        int ret = 0;

        if (!init) goto cleanup;

        ret = ip_conntrack_init();

        if (ret < 0)

                goto cleanup_nothing;

        proc = proc_net_create("ip_conntrack",0,list_conntracks);

        if (!proc) goto cleanup_init;

        proc->owner = THIS_MODULE;

        ret = nf_register_hook(&ip_conntrack_in_ops);

        if (ret < 0) {

                printk("ip_conntrack: can't register pre-routing hook.\n");

                goto cleanup_proc;

        }

        ret = nf_register_hook(&ip_conntrack_local_out_ops);

        if (ret < 0) {

                printk("ip_conntrack: can't register local out hook.\n");

                goto cleanup_inops;

        }

        ret = nf_register_hook(&ip_conntrack_out_ops);

        if (ret < 0) {

                printk("ip_conntrack: can't register post-routing hook.\n");

                goto cleanup_inandlocalops;

        }

        ret = nf_register_hook(&ip_conntrack_local_in_ops);

        if (ret < 0) {

                printk("ip_conntrack: can't register local in hook.\n");

                goto cleanup_inoutandlocalops;

        }

#ifdef CONFIG_SYSCTL

        ip_ct_sysctl_header = register_sysctl_table(ip_ct_net_table, 0);

        if (ip_ct_sysctl_header == NULL) {

                printk("ip_conntrack: can't register to sysctl.\n");

                goto cleanup;

        }

#endif

        return ret;

 cleanup:

#ifdef CONFIG_SYSCTL

        unregister_sysctl_table(ip_ct_sysctl_header);

#endif

        nf_unregister_hook(&ip_conntrack_local_in_ops);

 cleanup_inoutandlocalops:

        nf_unregister_hook(&ip_conntrack_out_ops);

 cleanup_inandlocalops:

        nf_unregister_hook(&ip_conntrack_local_out_ops);

 cleanup_inops:

        nf_unregister_hook(&ip_conntrack_in_ops);

 cleanup_proc:

        proc_net_remove("ip_conntrack");

 cleanup_init:

        ip_conntrack_cleanup();

 cleanup_nothing:

        return ret;

}

/* FIXME: Allow NULL functions and sub in pointers to generic for

   them. --RR */

int ip_conntrack_protocol_register(struct ip_conntrack_protocol *proto)

{

        int ret = 0;

        struct list_head *i;

        WRITE_LOCK(&ip_conntrack_lock);

        for (i = protocol_list.next; i != &protocol_list; i = i->next) {

                if (((struct ip_conntrack_protocol *)i)->proto

                    == proto->proto) {

                        ret = -EBUSY;

                        goto out;

                }

        }

        list_prepend(&protocol_list, proto);

        MOD_INC_USE_COUNT;

 out:

        WRITE_UNLOCK(&ip_conntrack_lock);

        return ret;

}

void ip_conntrack_protocol_unregister(struct ip_conntrack_protocol *proto)

{

        WRITE_LOCK(&ip_conntrack_lock);

        /* ip_ct_find_proto() returns proto_generic in case there is no protocol

         * helper. So this should be enough - HW */

        LIST_DELETE(&protocol_list, proto);

        WRITE_UNLOCK(&ip_conntrack_lock);

        /* Somebody could be still looking at the proto in bh. */

        br_write_lock_bh(BR_NETPROTO_LOCK);

        br_write_unlock_bh(BR_NETPROTO_LOCK);

        /* Remove all contrack entries for this protocol */

        ip_ct_selective_cleanup(kill_proto, &proto->proto);

        MOD_DEC_USE_COUNT;

}

static int __init init(void)

{

        return init_or_cleanup(1);

}

static void __exit fini(void)

{

        init_or_cleanup(0);

}

module_init(init);

module_exit(fini);

EXPORT_SYMBOL(ip_conntrack_protocol_register);

EXPORT_SYMBOL(ip_conntrack_protocol_unregister);

EXPORT_SYMBOL(invert_tuplepr);

EXPORT_SYMBOL(ip_conntrack_alter_reply);

EXPORT_SYMBOL(ip_conntrack_destroyed);

EXPORT_SYMBOL(ip_conntrack_get);

EXPORT_SYMBOL(ip_conntrack_helper_register);

EXPORT_SYMBOL(ip_conntrack_helper_unregister);

EXPORT_SYMBOL(ip_ct_selective_cleanup);

EXPORT_SYMBOL(ip_ct_refresh);

EXPORT_SYMBOL(ip_ct_find_proto);

EXPORT_SYMBOL(__ip_ct_find_proto);

EXPORT_SYMBOL(ip_ct_find_helper);

EXPORT_SYMBOL(ip_conntrack_expect_related);

EXPORT_SYMBOL(ip_conntrack_change_expect);

EXPORT_SYMBOL(ip_conntrack_unexpect_related);

EXPORT_SYMBOL_GPL(ip_conntrack_expect_find_get);

EXPORT_SYMBOL_GPL(ip_conntrack_expect_put);

EXPORT_SYMBOL(ip_conntrack_tuple_taken);

EXPORT_SYMBOL(ip_ct_gather_frags);

EXPORT_SYMBOL(ip_conntrack_htable_size);

EXPORT_SYMBOL(ip_conntrack_expect_list);

EXPORT_SYMBOL(ip_conntrack_lock);

EXPORT_SYMBOL(ip_conntrack_hash);

EXPORT_SYMBOL_GPL(ip_conntrack_find_get);

EXPORT_SYMBOL_GPL(ip_conntrack_put);