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

• Lines: 132
• Date: 2003-06-13 07:51:39.000000000 -0700
• Orig file: linux-2.4.20/net/ipv4/netfilter/ip_conntrack_tftp.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/net/ipv4/netfilter/ip_conntrack_tftp.c linux-2.4.21/net/ipv4/netfilter/ip_conntrack_tftp.c
@@ -0,0 +1,131 @@
+/*
+ * Licensed under GNU GPL version 2 Copyright Magnus Boden <mb@ozaba.mine.nu>
+ * Version: 0.0.7
+ *
+ * Thu 21 Mar 2002 Harald Welte <laforge@gnumonks.org>
+ * 	- port to newnat API
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_tftp.h>
+
+MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
+MODULE_DESCRIPTION("Netfilter connection tracking module for tftp");
+MODULE_LICENSE("GPL");
+
+#define MAX_PORTS 8
+static int ports[MAX_PORTS];
+static int ports_c = 0;
+#ifdef MODULE_PARM
+MODULE_PARM(ports, "1-" __MODULE_STRING(MAX_PORTS) "i");
+MODULE_PARM_DESC(ports, "port numbers of tftp servers");
+#endif
+
+#if 0
+#define DEBUGP(format, args...) printk(__FILE__ ":" __FUNCTION__ ": " \
+				       format, ## args)
+#else
+#define DEBUGP(format, args...)
+#endif
+
+static int tftp_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;
+	struct tftphdr *tftph = (void *)udph + 8;
+	struct ip_conntrack_expect exp;
+	
+	switch (ntohs(tftph->opcode)) {
+	/* RRQ and WRQ works the same way */
+	case TFTP_OPCODE_READ:
+	case TFTP_OPCODE_WRITE:
+		DEBUGP("");
+		DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
+		DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
+		memset(&exp, 0, sizeof(exp));
+
+		exp.tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple;
+		exp.mask.src.ip = 0xffffffff;
+		exp.mask.dst.ip = 0xffffffff;
+		exp.mask.dst.u.udp.port = 0xffff;
+		exp.mask.dst.protonum = 0xffff;
+		exp.expectfn = NULL;
+
+		DEBUGP("expect: ");
+		DUMP_TUPLE(&exp.tuple);
+		DUMP_TUPLE(&exp.mask);
+		ip_conntrack_expect_related(ct, &exp);
+		break;
+	default:
+		DEBUGP("Unknown opcode\n");
+	}
+	return NF_ACCEPT;
+}
+
+static struct ip_conntrack_helper tftp[MAX_PORTS];
+static char tftp_names[MAX_PORTS][10];
+
+static void fini(void)
+{
+	int i;
+
+	for (i = 0 ; i < ports_c; i++) {
+		DEBUGP("unregistering helper for port %d\n",
+			ports[i]);
+		ip_conntrack_helper_unregister(&tftp[i]);
+	} 
+}
+
+static int __init init(void)
+{
+	int i, ret;
+	char *tmpname;
+
+	if (!ports[0])
+		ports[0]=TFTP_PORT;
+
+	for (i = 0 ; (i < MAX_PORTS) && ports[i] ; i++) {
+		/* Create helper structure */
+		memset(&tftp[i], 0, sizeof(struct ip_conntrack_helper));
+
+		tftp[i].tuple.dst.protonum = IPPROTO_UDP;
+		tftp[i].tuple.src.u.udp.port = htons(ports[i]);
+		tftp[i].mask.dst.protonum = 0xFFFF;
+		tftp[i].mask.src.u.udp.port = 0xFFFF;
+		tftp[i].max_expected = 1;
+		tftp[i].timeout = 0;
+		tftp[i].flags = IP_CT_HELPER_F_REUSE_EXPECT;
+		tftp[i].me = THIS_MODULE;
+		tftp[i].help = tftp_help;
+
+		tmpname = &tftp_names[i][0];
+		if (ports[i] == TFTP_PORT)
+			sprintf(tmpname, "tftp");
+		else
+			sprintf(tmpname, "tftp-%d", i);
+		tftp[i].name = tmpname;
+
+		DEBUGP("port #%d: %d\n", i, ports[i]);
+
+		ret=ip_conntrack_helper_register(&tftp[i]);
+		if (ret) {
+			printk("ERROR registering helper for port %d\n",
+				ports[i]);
+			fini();
+			return(ret);
+		}
+		ports_c++;
+	}
+	return(0);
+}
+
+module_init(init);
+module_exit(fini);