Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/* IRC extension for TCP NAT alteration.

 *

 * (C) 2000-2001 by Harald Welte <laforge@gnumonks.org>

 * (C) 2004 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation

 * based on a copy of RR's ip_nat_ftp.c

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version

 * 2 of the License, or (at your option) any later version.

 */

#include <linux/module.h>

#include <linux/moduleparam.h>

#include <linux/tcp.h>

#include <linux/kernel.h>

#include <net/netfilter/nf_nat.h>

#include <net/netfilter/nf_nat_helper.h>

#include <net/netfilter/nf_nat_rule.h>

#include <net/netfilter/nf_conntrack_helper.h>

#include <net/netfilter/nf_conntrack_expect.h>

#include <linux/netfilter/nf_conntrack_irc.h>

MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");

MODULE_DESCRIPTION("IRC (DCC) NAT helper");

MODULE_LICENSE("GPL");

MODULE_ALIAS("ip_nat_irc");

static unsigned int help(struct sk_buff *skb,

                         enum ip_conntrack_info ctinfo,

                         unsigned int matchoff,

                         unsigned int matchlen,

                         struct nf_conntrack_expect *exp)

{

        char buffer[sizeof("4294967296 65635")];

        u_int32_t ip;

        u_int16_t port;

        unsigned int ret;

        /* Reply comes from server. */

        exp->saved_proto.tcp.port = exp->tuple.dst.u.tcp.port;

        exp->dir = IP_CT_DIR_REPLY;

        exp->expectfn = nf_nat_follow_master;

        /* Try to get same port: if not, try to change it. */

        for (port = ntohs(exp->saved_proto.tcp.port); port != 0; port++) {

                exp->tuple.dst.u.tcp.port = htons(port);

                if (nf_ct_expect_related(exp) == 0)

                        break;

        }

        if (port == 0)

                return NF_DROP;

        ip = ntohl(exp->master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip);

        sprintf(buffer, "%u %u", ip, port);

        pr_debug("nf_nat_irc: inserting '%s' == %u.%u.%u.%u, port %u\n",

                 buffer, NIPQUAD(ip), port);

        ret = nf_nat_mangle_tcp_packet(skb, exp->master, ctinfo,

                                       matchoff, matchlen, buffer,

                                       strlen(buffer));

        if (ret != NF_ACCEPT)

                nf_ct_unexpect_related(exp);

        return ret;

}

static void __exit nf_nat_irc_fini(void)

{

        rcu_assign_pointer(nf_nat_irc_hook, NULL);

        synchronize_rcu();

}

static int __init nf_nat_irc_init(void)

{

        BUG_ON(nf_nat_irc_hook != NULL);

        rcu_assign_pointer(nf_nat_irc_hook, help);

        return 0;

}

/* Prior to 2.6.11, we had a ports param.  No longer, but don't break users. */

static int warn_set(const char *val, struct kernel_param *kp)

{

        printk(KERN_INFO KBUILD_MODNAME

               ": kernel >= 2.6.10 only uses 'ports' for conntrack modules\n");

        return 0;

}

module_param_call(ports, warn_set, NULL, NULL, 0);

module_init(nf_nat_irc_init);

module_exit(nf_nat_irc_fini);