1 /* Amanda extension for IP connection tracking
3 * (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca>
4 * based on HW's ip_conntrack_irc.c as well as other modules
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/moduleparam.h>
14 #include <linux/textsearch.h>
15 #include <linux/skbuff.h>
17 #include <linux/udp.h>
18 #include <linux/netfilter.h>
19 #include <linux/gfp.h>
21 #include <net/netfilter/nf_conntrack.h>
22 #include <net/netfilter/nf_conntrack_expect.h>
23 #include <net/netfilter/nf_conntrack_ecache.h>
24 #include <net/netfilter/nf_conntrack_helper.h>
25 #include <linux/netfilter/nf_conntrack_amanda.h>
27 static unsigned int master_timeout __read_mostly = 300;
28 static char *ts_algo = "kmp";
30 MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");
31 MODULE_DESCRIPTION("Amanda connection tracking module");
32 MODULE_LICENSE("GPL");
33 MODULE_ALIAS("ip_conntrack_amanda");
34 MODULE_ALIAS_NFCT_HELPER("amanda");
36 module_param(master_timeout, uint, 0600);
37 MODULE_PARM_DESC(master_timeout, "timeout for the master connection");
38 module_param(ts_algo, charp, 0400);
39 MODULE_PARM_DESC(ts_algo, "textsearch algorithm to use (default kmp)");
41 unsigned int (*nf_nat_amanda_hook)(struct sk_buff *skb,
42 enum ip_conntrack_info ctinfo,
43 unsigned int matchoff,
44 unsigned int matchlen,
45 struct nf_conntrack_expect *exp)
47 EXPORT_SYMBOL_GPL(nf_nat_amanda_hook);
61 } search[] __read_mostly = {
84 static int amanda_help(struct sk_buff *skb,
87 enum ip_conntrack_info ctinfo)
90 struct nf_conntrack_expect *exp;
91 struct nf_conntrack_tuple *tuple;
92 unsigned int dataoff, start, stop, off, i;
93 char pbuf[sizeof("65535")], *tmp;
97 typeof(nf_nat_amanda_hook) nf_nat_amanda;
99 /* Only look at packets from the Amanda server */
100 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
103 /* increase the UDP timeout of the master connection as replies from
104 * Amanda clients to the server can be quite delayed */
105 nf_ct_refresh(ct, skb, master_timeout * HZ);
108 dataoff = protoff + sizeof(struct udphdr);
109 if (dataoff >= skb->len) {
111 printk(KERN_ERR "amanda_help: skblen = %u\n", skb->len);
115 memset(&ts, 0, sizeof(ts));
116 start = skb_find_text(skb, dataoff, skb->len,
117 search[SEARCH_CONNECT].ts, &ts);
118 if (start == UINT_MAX)
120 start += dataoff + search[SEARCH_CONNECT].len;
122 memset(&ts, 0, sizeof(ts));
123 stop = skb_find_text(skb, start, skb->len,
124 search[SEARCH_NEWLINE].ts, &ts);
125 if (stop == UINT_MAX)
129 for (i = SEARCH_DATA; i <= SEARCH_INDEX; i++) {
130 memset(&ts, 0, sizeof(ts));
131 off = skb_find_text(skb, start, stop, search[i].ts, &ts);
134 off += start + search[i].len;
136 len = min_t(unsigned int, sizeof(pbuf) - 1, stop - off);
137 if (skb_copy_bits(skb, off, pbuf, len))
141 port = htons(simple_strtoul(pbuf, &tmp, 10));
143 if (port == 0 || len > 5)
146 exp = nf_ct_expect_alloc(ct);
151 tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
152 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
154 &tuple->src.u3, &tuple->dst.u3,
155 IPPROTO_TCP, NULL, &port);
157 nf_nat_amanda = rcu_dereference(nf_nat_amanda_hook);
158 if (nf_nat_amanda && ct->status & IPS_NAT_MASK)
159 ret = nf_nat_amanda(skb, ctinfo, off - dataoff,
161 else if (nf_ct_expect_related(exp) != 0)
163 nf_ct_expect_put(exp);
170 static const struct nf_conntrack_expect_policy amanda_exp_policy = {
175 static struct nf_conntrack_helper amanda_helper[2] __read_mostly = {
180 .tuple.src.l3num = AF_INET,
181 .tuple.src.u.udp.port = cpu_to_be16(10080),
182 .tuple.dst.protonum = IPPROTO_UDP,
183 .expect_policy = &amanda_exp_policy,
189 .tuple.src.l3num = AF_INET6,
190 .tuple.src.u.udp.port = cpu_to_be16(10080),
191 .tuple.dst.protonum = IPPROTO_UDP,
192 .expect_policy = &amanda_exp_policy,
196 static void __exit nf_conntrack_amanda_fini(void)
200 nf_conntrack_helper_unregister(&amanda_helper[0]);
201 nf_conntrack_helper_unregister(&amanda_helper[1]);
202 for (i = 0; i < ARRAY_SIZE(search); i++)
203 textsearch_destroy(search[i].ts);
206 static int __init nf_conntrack_amanda_init(void)
210 for (i = 0; i < ARRAY_SIZE(search); i++) {
211 search[i].ts = textsearch_prepare(ts_algo, search[i].string,
213 GFP_KERNEL, TS_AUTOLOAD);
214 if (IS_ERR(search[i].ts)) {
215 ret = PTR_ERR(search[i].ts);
219 ret = nf_conntrack_helper_register(&amanda_helper[0]);
222 ret = nf_conntrack_helper_register(&amanda_helper[1]);
228 nf_conntrack_helper_unregister(&amanda_helper[0]);
231 textsearch_destroy(search[i].ts);
236 module_init(nf_conntrack_amanda_init);
237 module_exit(nf_conntrack_amanda_fini);