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,
44 unsigned int matchoff,
45 unsigned int matchlen,
46 struct nf_conntrack_expect *exp)
48 EXPORT_SYMBOL_GPL(nf_nat_amanda_hook);
62 } search[] __read_mostly = {
85 static int amanda_help(struct sk_buff *skb,
88 enum ip_conntrack_info ctinfo)
91 struct nf_conntrack_expect *exp;
92 struct nf_conntrack_tuple *tuple;
93 unsigned int dataoff, start, stop, off, i;
94 char pbuf[sizeof("65535")], *tmp;
98 typeof(nf_nat_amanda_hook) nf_nat_amanda;
100 /* Only look at packets from the Amanda server */
101 if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
104 /* increase the UDP timeout of the master connection as replies from
105 * Amanda clients to the server can be quite delayed */
106 nf_ct_refresh(ct, skb, master_timeout * HZ);
109 dataoff = protoff + sizeof(struct udphdr);
110 if (dataoff >= skb->len) {
111 net_err_ratelimited("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);
148 nf_ct_helper_log(skb, ct, "cannot alloc expectation");
152 tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
153 nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
155 &tuple->src.u3, &tuple->dst.u3,
156 IPPROTO_TCP, NULL, &port);
158 nf_nat_amanda = rcu_dereference(nf_nat_amanda_hook);
159 if (nf_nat_amanda && ct->status & IPS_NAT_MASK)
160 ret = nf_nat_amanda(skb, ctinfo, protoff,
161 off - dataoff, len, exp);
162 else if (nf_ct_expect_related(exp) != 0) {
163 nf_ct_helper_log(skb, ct, "cannot add expectation");
166 nf_ct_expect_put(exp);
173 static const struct nf_conntrack_expect_policy amanda_exp_policy = {
178 static struct nf_conntrack_helper amanda_helper[2] __read_mostly = {
183 .tuple.src.l3num = AF_INET,
184 .tuple.src.u.udp.port = cpu_to_be16(10080),
185 .tuple.dst.protonum = IPPROTO_UDP,
186 .expect_policy = &amanda_exp_policy,
192 .tuple.src.l3num = AF_INET6,
193 .tuple.src.u.udp.port = cpu_to_be16(10080),
194 .tuple.dst.protonum = IPPROTO_UDP,
195 .expect_policy = &amanda_exp_policy,
199 static void __exit nf_conntrack_amanda_fini(void)
203 nf_conntrack_helper_unregister(&amanda_helper[0]);
204 nf_conntrack_helper_unregister(&amanda_helper[1]);
205 for (i = 0; i < ARRAY_SIZE(search); i++)
206 textsearch_destroy(search[i].ts);
209 static int __init nf_conntrack_amanda_init(void)
213 for (i = 0; i < ARRAY_SIZE(search); i++) {
214 search[i].ts = textsearch_prepare(ts_algo, search[i].string,
216 GFP_KERNEL, TS_AUTOLOAD);
217 if (IS_ERR(search[i].ts)) {
218 ret = PTR_ERR(search[i].ts);
222 ret = nf_conntrack_helper_register(&amanda_helper[0]);
225 ret = nf_conntrack_helper_register(&amanda_helper[1]);
231 nf_conntrack_helper_unregister(&amanda_helper[0]);
234 textsearch_destroy(search[i].ts);
239 module_init(nf_conntrack_amanda_init);
240 module_exit(nf_conntrack_amanda_fini);