--- /dev/null
+/* Amanda extension for IP connection tracking
+ *
+ * (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca>
+ * based on HW's ip_conntrack_irc.c as well as other modules
+ * (C) 2006 Patrick McHardy <kaber@trash.net>
+ *
+ * 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/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/textsearch.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/udp.h>
+#include <linux/netfilter.h>
+#include <linux/gfp.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <linux/netfilter/nf_conntrack_amanda.h>
+
+static unsigned int master_timeout __read_mostly = 300;
+static char *ts_algo = "kmp";
+
+MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");
+MODULE_DESCRIPTION("Amanda connection tracking module");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ip_conntrack_amanda");
+MODULE_ALIAS_NFCT_HELPER("amanda");
+
+module_param(master_timeout, uint, 0600);
+MODULE_PARM_DESC(master_timeout, "timeout for the master connection");
+module_param(ts_algo, charp, 0400);
+MODULE_PARM_DESC(ts_algo, "textsearch algorithm to use (default kmp)");
+
+unsigned int (*nf_nat_amanda_hook)(struct sk_buff *skb,
+ enum ip_conntrack_info ctinfo,
+ unsigned int protoff,
+ unsigned int matchoff,
+ unsigned int matchlen,
+ struct nf_conntrack_expect *exp)
+ __read_mostly;
+EXPORT_SYMBOL_GPL(nf_nat_amanda_hook);
+
+enum amanda_strings {
+ SEARCH_CONNECT,
+ SEARCH_NEWLINE,
+ SEARCH_DATA,
+ SEARCH_MESG,
+ SEARCH_INDEX,
+};
+
+static struct {
+ const char *string;
+ size_t len;
+ struct ts_config *ts;
+} search[] __read_mostly = {
+ [SEARCH_CONNECT] = {
+ .string = "CONNECT ",
+ .len = 8,
+ },
+ [SEARCH_NEWLINE] = {
+ .string = "\n",
+ .len = 1,
+ },
+ [SEARCH_DATA] = {
+ .string = "DATA ",
+ .len = 5,
+ },
+ [SEARCH_MESG] = {
+ .string = "MESG ",
+ .len = 5,
+ },
+ [SEARCH_INDEX] = {
+ .string = "INDEX ",
+ .len = 6,
+ },
+};
+
+static int amanda_help(struct sk_buff *skb,
+ unsigned int protoff,
+ struct nf_conn *ct,
+ enum ip_conntrack_info ctinfo)
+{
+ struct nf_conntrack_expect *exp;
+ struct nf_conntrack_tuple *tuple;
+ unsigned int dataoff, start, stop, off, i;
+ char pbuf[sizeof("65535")], *tmp;
+ u_int16_t len;
+ __be16 port;
+ int ret = NF_ACCEPT;
+ typeof(nf_nat_amanda_hook) nf_nat_amanda;
+
+ /* Only look at packets from the Amanda server */
+ if (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL)
+ return NF_ACCEPT;
+
+ /* increase the UDP timeout of the master connection as replies from
+ * Amanda clients to the server can be quite delayed */
+ nf_ct_refresh(ct, skb, master_timeout * HZ);
+
+ /* No data? */
+ dataoff = protoff + sizeof(struct udphdr);
+ if (dataoff >= skb->len) {
+ net_err_ratelimited("amanda_help: skblen = %u\n", skb->len);
+ return NF_ACCEPT;
+ }
+
+ start = skb_find_text(skb, dataoff, skb->len,
+ search[SEARCH_CONNECT].ts);
+ if (start == UINT_MAX)
+ goto out;
+ start += dataoff + search[SEARCH_CONNECT].len;
+
+ stop = skb_find_text(skb, start, skb->len,
+ search[SEARCH_NEWLINE].ts);
+ if (stop == UINT_MAX)
+ goto out;
+ stop += start;
+
+ for (i = SEARCH_DATA; i <= SEARCH_INDEX; i++) {
+ off = skb_find_text(skb, start, stop, search[i].ts);
+ if (off == UINT_MAX)
+ continue;
+ off += start + search[i].len;
+
+ len = min_t(unsigned int, sizeof(pbuf) - 1, stop - off);
+ if (skb_copy_bits(skb, off, pbuf, len))
+ break;
+ pbuf[len] = '\0';
+
+ port = htons(simple_strtoul(pbuf, &tmp, 10));
+ len = tmp - pbuf;
+ if (port == 0 || len > 5)
+ break;
+
+ exp = nf_ct_expect_alloc(ct);
+ if (exp == NULL) {
+ nf_ct_helper_log(skb, ct, "cannot alloc expectation");
+ ret = NF_DROP;
+ goto out;
+ }
+ tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
+ nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT,
+ nf_ct_l3num(ct),
+ &tuple->src.u3, &tuple->dst.u3,
+ IPPROTO_TCP, NULL, &port);
+
+ nf_nat_amanda = rcu_dereference(nf_nat_amanda_hook);
+ if (nf_nat_amanda && ct->status & IPS_NAT_MASK)
+ ret = nf_nat_amanda(skb, ctinfo, protoff,
+ off - dataoff, len, exp);
+ else if (nf_ct_expect_related(exp) != 0) {
+ nf_ct_helper_log(skb, ct, "cannot add expectation");
+ ret = NF_DROP;
+ }
+ nf_ct_expect_put(exp);
+ }
+
+out:
+ return ret;
+}
+
+static const struct nf_conntrack_expect_policy amanda_exp_policy = {
+ .max_expected = 3,
+ .timeout = 180,
+};
+
+static struct nf_conntrack_helper amanda_helper[2] __read_mostly = {
+ {
+ .name = "amanda",
+ .me = THIS_MODULE,
+ .help = amanda_help,
+ .tuple.src.l3num = AF_INET,
+ .tuple.src.u.udp.port = cpu_to_be16(10080),
+ .tuple.dst.protonum = IPPROTO_UDP,
+ .expect_policy = &amanda_exp_policy,
+ },
+ {
+ .name = "amanda",
+ .me = THIS_MODULE,
+ .help = amanda_help,
+ .tuple.src.l3num = AF_INET6,
+ .tuple.src.u.udp.port = cpu_to_be16(10080),
+ .tuple.dst.protonum = IPPROTO_UDP,
+ .expect_policy = &amanda_exp_policy,
+ },
+};
+
+static void __exit nf_conntrack_amanda_fini(void)
+{
+ int i;
+
+ nf_conntrack_helper_unregister(&amanda_helper[0]);
+ nf_conntrack_helper_unregister(&amanda_helper[1]);
+ for (i = 0; i < ARRAY_SIZE(search); i++)
+ textsearch_destroy(search[i].ts);
+}
+
+static int __init nf_conntrack_amanda_init(void)
+{
+ int ret, i;
+
+ for (i = 0; i < ARRAY_SIZE(search); i++) {
+ search[i].ts = textsearch_prepare(ts_algo, search[i].string,
+ search[i].len,
+ GFP_KERNEL, TS_AUTOLOAD);
+ if (IS_ERR(search[i].ts)) {
+ ret = PTR_ERR(search[i].ts);
+ goto err1;
+ }
+ }
+ ret = nf_conntrack_helper_register(&amanda_helper[0]);
+ if (ret < 0)
+ goto err1;
+ ret = nf_conntrack_helper_register(&amanda_helper[1]);
+ if (ret < 0)
+ goto err2;
+ return 0;
+
+err2:
+ nf_conntrack_helper_unregister(&amanda_helper[0]);
+err1:
+ while (--i >= 0)
+ textsearch_destroy(search[i].ts);
+
+ return ret;
+}
+
+module_init(nf_conntrack_amanda_init);
+module_exit(nf_conntrack_amanda_fini);
Code Review / kvmfornfv.git / blobdiff