patch-2.4.21 linux-2.4.21/net/ipv4/netfilter/ip_conntrack_amanda.c

• Lines: 236
• Date: 2003-06-13 07:51:39.000000000 -0700
• Orig file: linux-2.4.20/net/ipv4/netfilter/ip_conntrack_amanda.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/net/ipv4/netfilter/ip_conntrack_amanda.c linux-2.4.21/net/ipv4/netfilter/ip_conntrack_amanda.c
@@ -0,0 +1,235 @@
+/* Amanda extension for IP connection tracking, Version 0.2
+ * (C) 2002 by Brian J. Murrell <netfilter@interlinx.bc.ca>
+ * based on HW's ip_conntrack_irc.c as well as other modules
+ *
+ *      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.
+ *
+ *	Module load syntax:
+ * 	insmod ip_conntrack_amanda.o [master_timeout=n]
+ *	
+ *	Where master_timeout is the timeout (in seconds) of the master
+ *	connection (port 10080).  This defaults to 5 minutes but if
+ *	your clients take longer than 5 minutes to do their work
+ *	before getting back to the Amanda server, you can increase
+ *	this value.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/udp.h>
+
+#include <linux/netfilter_ipv4/lockhelp.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_amanda.h>
+
+static unsigned int master_timeout = 300;
+
+MODULE_AUTHOR("Brian J. Murrell <netfilter@interlinx.bc.ca>");
+MODULE_DESCRIPTION("Amanda connection tracking module");
+MODULE_LICENSE("GPL");
+MODULE_PARM(master_timeout, "i");
+MODULE_PARM_DESC(master_timeout, "timeout for the master connection");
+
+DECLARE_LOCK(ip_amanda_lock);
+struct module *ip_conntrack_amanda = THIS_MODULE;
+
+#define MAXMATCHLEN	6
+struct conn conns[NUM_MSGS] = {
+	{"DATA ", 5},
+	{"MESG ", 5},
+	{"INDEX ", 6},
+};
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+
+/* FIXME: This should be in userspace.  Later. */
+static int help(const struct iphdr *iph, size_t len,
+		struct ip_conntrack *ct, enum ip_conntrack_info ctinfo)
+{
+	struct udphdr *udph = (void *)iph + iph->ihl * 4;
+	u_int32_t udplen = len - iph->ihl * 4;
+	u_int32_t datalen = udplen - sizeof(struct udphdr);
+	char *data = (char *)udph + sizeof(struct udphdr);
+	char *datap = data;
+	char *data_limit = (char *) data + datalen;
+	int dir = CTINFO2DIR(ctinfo);
+	struct ip_ct_amanda *info =
+				(struct ip_ct_amanda *)&ct->help.ct_ftp_info;
+
+	/* Can't track connections formed before we registered */
+	if (!info)
+		return NF_ACCEPT;
+
+	/* increase the UDP timeout of the master connection as replies from
+	 * Amanda clients to the server can be quite delayed */
+	ip_ct_refresh(ct, master_timeout * HZ);
+
+	/* If packet is coming from Amanda server */
+	if (dir == IP_CT_DIR_ORIGINAL)
+		return NF_ACCEPT;
+
+	/* Not whole UDP header? */
+	if (udplen < sizeof(struct udphdr)) {
+		printk("ip_conntrack_amanda_help: udplen = %u\n",
+		       (unsigned)udplen);
+		return NF_ACCEPT;
+	}
+
+	/* Checksum invalid?  Ignore. */
+	if (csum_tcpudp_magic(iph->saddr, iph->daddr, udplen, IPPROTO_UDP,
+			      csum_partial((char *)udph, udplen, 0))) {
+		DEBUGP("ip_ct_talk_help: bad csum: %p %u %u.%u.%u.%u "
+		       "%u.%u.%u.%u\n",
+		       udph, udplen, NIPQUAD(iph->saddr),
+		       NIPQUAD(iph->daddr));
+		return NF_ACCEPT;
+	}
+	
+	/* Search for the CONNECT string */
+	while (data < data_limit) {
+		if (!memcmp(data, "CONNECT ", 8)) {
+			break;
+		}
+		data++;
+	}
+	if (memcmp(data, "CONNECT ", 8))
+		return NF_ACCEPT;
+
+	DEBUGP("ip_conntrack_amanda_help: CONNECT found in connection "
+		   "%u.%u.%u.%u:%u %u.%u.%u.%u:%u\n",
+		   NIPQUAD(iph->saddr), htons(udph->source),
+		   NIPQUAD(iph->daddr), htons(udph->dest));
+	data += 8;
+	while (*data != 0x0a && data < data_limit) {
+
+		int i;
+
+		for (i = 0; i < NUM_MSGS; i++) {
+			if (!memcmp(data, conns[i].match,
+				   conns[i].matchlen)) {
+
+				char *portchr;
+				struct ip_conntrack_expect expect;
+				struct ip_ct_amanda_expect
+				    *exp_amanda_info =
+					&expect.help.exp_amanda_info;
+
+				memset(&expect, 0, sizeof(expect));
+
+				data += conns[i].matchlen;
+				/* this is not really tcp, but let's steal an
+				 * idea from a tcp stream helper :-)
+				 */
+				// XXX expect.seq = data - datap;
+				exp_amanda_info->offset = data - datap;
+// XXX DEBUGP("expect.seq = %p - %p = %d\n", data, datap, expect.seq);
+DEBUGP("exp_amanda_info->offset = %p - %p = %d\n", data, datap, exp_amanda_info->offset);
+				portchr = data;
+				exp_amanda_info->port =
+				    simple_strtoul(data, &data, 10);
+				exp_amanda_info->len = data - portchr;
+
+				/* eat whitespace */
+				while (*data == ' ')
+					data++;
+				DEBUGP ("ip_conntrack_amanda_help: "
+					"CONNECT %s request with port "
+					"%u found\n", conns[i].match,
+					exp_amanda_info->port);
+
+				LOCK_BH(&ip_amanda_lock);
+
+				expect.tuple = ((struct ip_conntrack_tuple)
+						{ { ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip,
+						  { 0 } },
+				  		{ ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip,
+						  { htons(exp_amanda_info->port) },
+				    	  IPPROTO_TCP }});
+				expect.mask = ((struct ip_conntrack_tuple)
+							   { { 0, { 0 } },
+				  				 { 0xFFFFFFFF, { 0xFFFF }, 0xFFFF }});
+
+				expect.expectfn = NULL;
+
+				DEBUGP ("ip_conntrack_amanda_help: "
+					"expect_related: %u.%u.%u.%u:%u - "
+					"%u.%u.%u.%u:%u\n",
+					NIPQUAD(expect.tuple.src.ip),
+					ntohs(expect.tuple.src.u.tcp.port),
+					NIPQUAD(expect.tuple.dst.ip),
+					ntohs(expect.tuple.dst.u.tcp.port));
+				if (ip_conntrack_expect_related(ct, &expect) ==
+				    -EEXIST) {
+					;
+					/* this must be a packet being resent */
+					/* XXX - how do I get the
+					 *       ip_conntrack_expect that
+					 *       already exists so that I can
+					 *       update the .seq so that the
+					 *       nat module rewrites the port
+					 *       numbers?
+					 *       Perhaps I should use the
+					 *       exp_amanda_info instead of
+					 *       .seq.
+					 */
+				}
+				UNLOCK_BH(&ip_amanda_lock);
+			} /* if memcmp(conns) */
+		} /* for .. NUM_MSGS */
+		data++;
+	} /* while (*data != 0x0a && data < data_limit) */
+
+	return NF_ACCEPT;
+}
+
+static struct ip_conntrack_helper amanda_helper;
+
+static void fini(void)
+{
+	DEBUGP("ip_ct_amanda: unregistering helper for port 10080\n");
+	ip_conntrack_helper_unregister(&amanda_helper);
+}
+
+static int __init init(void)
+{
+	int ret;
+
+	memset(&amanda_helper, 0, sizeof(struct ip_conntrack_helper));
+	amanda_helper.tuple.src.u.udp.port = htons(10080);
+	amanda_helper.tuple.dst.protonum = IPPROTO_UDP;
+	amanda_helper.mask.src.u.udp.port = 0xFFFF;
+	amanda_helper.mask.dst.protonum = 0xFFFF;
+	amanda_helper.max_expected = NUM_MSGS;
+	amanda_helper.timeout = 180;
+	amanda_helper.flags = IP_CT_HELPER_F_REUSE_EXPECT;
+	amanda_helper.me = ip_conntrack_amanda;
+	amanda_helper.help = help;
+	amanda_helper.name = "amanda";
+
+	DEBUGP("ip_ct_amanda: registering helper for port 10080\n");
+
+	ret = ip_conntrack_helper_register(&amanda_helper);
+
+	if (ret) {
+		printk("ip_ct_amanda: ERROR registering helper\n");
+		fini();
+		return -EBUSY;
+	}
+	return 0;
+}
+
+EXPORT_SYMBOL(ip_amanda_lock);
+
+module_init(init);
+module_exit(fini);