2005-04-16 22:20:36 +00:00
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/* Amanda extension for IP connection tracking, Version 0.2
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* (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca>
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* based on HW's ip_conntrack_irc.c as well as other modules
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Module load syntax:
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* insmod ip_conntrack_amanda.o [master_timeout=n]
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*
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* Where master_timeout is the timeout (in seconds) of the master
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* connection (port 10080). This defaults to 5 minutes but if
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* your clients take longer than 5 minutes to do their work
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* before getting back to the Amanda server, you can increase
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* this value.
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*
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*/
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2005-12-27 04:43:12 +00:00
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#include <linux/in.h>
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2005-04-16 22:20:36 +00:00
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/netfilter.h>
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#include <linux/ip.h>
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#include <linux/moduleparam.h>
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2005-12-27 04:43:12 +00:00
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#include <linux/udp.h>
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2005-04-16 22:20:36 +00:00
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#include <net/checksum.h>
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#include <net/udp.h>
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#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
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#include <linux/netfilter_ipv4/ip_conntrack_amanda.h>
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static unsigned int master_timeout = 300;
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MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");
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MODULE_DESCRIPTION("Amanda connection tracking module");
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MODULE_LICENSE("GPL");
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module_param(master_timeout, int, 0600);
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MODULE_PARM_DESC(master_timeout, "timeout for the master connection");
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2005-11-30 00:21:38 +00:00
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static const char *conns[] = { "DATA ", "MESG ", "INDEX " };
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2005-04-16 22:20:36 +00:00
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/* This is slow, but it's simple. --RR */
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2005-08-10 03:19:44 +00:00
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static char *amanda_buffer;
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2005-06-21 21:01:30 +00:00
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static DEFINE_SPINLOCK(amanda_buffer_lock);
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2005-04-16 22:20:36 +00:00
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unsigned int (*ip_nat_amanda_hook)(struct sk_buff **pskb,
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enum ip_conntrack_info ctinfo,
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unsigned int matchoff,
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unsigned int matchlen,
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struct ip_conntrack_expect *exp);
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EXPORT_SYMBOL_GPL(ip_nat_amanda_hook);
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static int help(struct sk_buff **pskb,
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struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
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{
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struct ip_conntrack_expect *exp;
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char *data, *data_limit, *tmp;
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unsigned int dataoff, i;
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u_int16_t port, len;
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int ret = NF_ACCEPT;
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/* Only look at packets from the Amanda server */
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if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
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return NF_ACCEPT;
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/* increase the UDP timeout of the master connection as replies from
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* Amanda clients to the server can be quite delayed */
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2005-09-23 06:46:57 +00:00
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ip_ct_refresh(ct, *pskb, master_timeout * HZ);
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2005-04-16 22:20:36 +00:00
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/* No data? */
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dataoff = (*pskb)->nh.iph->ihl*4 + sizeof(struct udphdr);
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if (dataoff >= (*pskb)->len) {
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if (net_ratelimit())
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printk("amanda_help: skblen = %u\n", (*pskb)->len);
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return NF_ACCEPT;
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}
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2005-06-21 21:01:30 +00:00
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spin_lock_bh(&amanda_buffer_lock);
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2005-04-16 22:20:36 +00:00
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skb_copy_bits(*pskb, dataoff, amanda_buffer, (*pskb)->len - dataoff);
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data = amanda_buffer;
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data_limit = amanda_buffer + (*pskb)->len - dataoff;
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*data_limit = '\0';
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/* Search for the CONNECT string */
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data = strstr(data, "CONNECT ");
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if (!data)
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goto out;
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data += strlen("CONNECT ");
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/* Only search first line. */
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if ((tmp = strchr(data, '\n')))
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*tmp = '\0';
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for (i = 0; i < ARRAY_SIZE(conns); i++) {
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char *match = strstr(data, conns[i]);
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if (!match)
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continue;
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tmp = data = match + strlen(conns[i]);
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port = simple_strtoul(data, &data, 10);
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len = data - tmp;
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if (port == 0 || len > 5)
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break;
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2005-07-21 20:14:46 +00:00
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exp = ip_conntrack_expect_alloc(ct);
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2005-04-16 22:20:36 +00:00
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if (exp == NULL) {
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ret = NF_DROP;
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goto out;
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}
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exp->expectfn = NULL;
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2005-09-06 22:06:42 +00:00
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exp->flags = 0;
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2005-04-16 22:20:36 +00:00
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exp->tuple.src.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
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exp->tuple.src.u.tcp.port = 0;
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exp->tuple.dst.ip = ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
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exp->tuple.dst.protonum = IPPROTO_TCP;
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exp->tuple.dst.u.tcp.port = htons(port);
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exp->mask.src.ip = 0xFFFFFFFF;
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exp->mask.src.u.tcp.port = 0;
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exp->mask.dst.ip = 0xFFFFFFFF;
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exp->mask.dst.protonum = 0xFF;
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exp->mask.dst.u.tcp.port = 0xFFFF;
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if (ip_nat_amanda_hook)
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ret = ip_nat_amanda_hook(pskb, ctinfo,
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tmp - amanda_buffer,
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len, exp);
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2005-07-21 20:14:46 +00:00
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else if (ip_conntrack_expect_related(exp) != 0)
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2005-04-16 22:20:36 +00:00
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ret = NF_DROP;
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2005-07-21 20:14:46 +00:00
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ip_conntrack_expect_put(exp);
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2005-04-16 22:20:36 +00:00
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}
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out:
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2005-06-21 21:01:30 +00:00
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spin_unlock_bh(&amanda_buffer_lock);
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2005-04-16 22:20:36 +00:00
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return ret;
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}
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static struct ip_conntrack_helper amanda_helper = {
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.max_expected = ARRAY_SIZE(conns),
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.timeout = 180,
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.me = THIS_MODULE,
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.help = help,
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.name = "amanda",
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.tuple = { .src = { .u = { __constant_htons(10080) } },
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.dst = { .protonum = IPPROTO_UDP },
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},
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.mask = { .src = { .u = { 0xFFFF } },
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.dst = { .protonum = 0xFF },
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},
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};
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static void __exit fini(void)
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{
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ip_conntrack_helper_unregister(&amanda_helper);
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2005-08-10 03:19:44 +00:00
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kfree(amanda_buffer);
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2005-04-16 22:20:36 +00:00
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}
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static int __init init(void)
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{
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2005-08-10 03:19:44 +00:00
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int ret;
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amanda_buffer = kmalloc(65536, GFP_KERNEL);
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if (!amanda_buffer)
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return -ENOMEM;
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ret = ip_conntrack_helper_register(&amanda_helper);
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if (ret < 0) {
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kfree(amanda_buffer);
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return ret;
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}
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return 0;
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2005-04-16 22:20:36 +00:00
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}
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module_init(init);
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module_exit(fini);
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