1 /* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu>
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 as
5 * published by the Free Software Foundation.
9 * Thu 21 Mar 2002 Harald Welte <laforge@gnumonks.org>
10 * - port to newnat API
14 #include <linux/module.h>
16 #include <linux/udp.h>
18 #include <linux/netfilter.h>
19 #include <linux/netfilter_ipv4/ip_tables.h>
20 #include <linux/netfilter_ipv4/ip_conntrack_helper.h>
21 #include <linux/netfilter_ipv4/ip_conntrack_tftp.h>
22 #include <linux/moduleparam.h>
24 MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
25 MODULE_DESCRIPTION("tftp connection tracking helper");
26 MODULE_LICENSE("GPL");
29 static int ports[MAX_PORTS];
31 module_param_array(ports, int, &ports_c, 0400);
32 MODULE_PARM_DESC(ports, "port numbers of tftp servers");
35 #define DEBUGP(format, args...) printk("%s:%s:" format, \
36 __FILE__, __FUNCTION__ , ## args)
38 #define DEBUGP(format, args...)
41 unsigned int (*ip_nat_tftp_hook)(struct sk_buff **pskb,
42 enum ip_conntrack_info ctinfo,
43 struct ip_conntrack_expect *exp);
44 EXPORT_SYMBOL_GPL(ip_nat_tftp_hook);
46 static int tftp_help(struct sk_buff **pskb,
47 struct ip_conntrack *ct,
48 enum ip_conntrack_info ctinfo)
50 struct tftphdr _tftph, *tfh;
51 struct ip_conntrack_expect *exp;
52 unsigned int ret = NF_ACCEPT;
54 tfh = skb_header_pointer(*pskb,
55 (*pskb)->nh.iph->ihl*4+sizeof(struct udphdr),
56 sizeof(_tftph), &_tftph);
60 switch (ntohs(tfh->opcode)) {
61 /* RRQ and WRQ works the same way */
62 case TFTP_OPCODE_READ:
63 case TFTP_OPCODE_WRITE:
65 DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
66 DUMP_TUPLE(&ct->tuplehash[IP_CT_DIR_REPLY].tuple);
68 exp = ip_conntrack_expect_alloc();
72 exp->tuple = ct->tuplehash[IP_CT_DIR_REPLY].tuple;
73 exp->mask.src.ip = 0xffffffff;
74 exp->mask.dst.ip = 0xffffffff;
75 exp->mask.dst.u.udp.port = 0xffff;
76 exp->mask.dst.protonum = 0xff;
81 DUMP_TUPLE(&exp->tuple);
82 DUMP_TUPLE(&exp->mask);
84 ret = ip_nat_tftp_hook(pskb, ctinfo, exp);
85 else if (ip_conntrack_expect_related(exp) != 0) {
86 ip_conntrack_expect_free(exp);
90 case TFTP_OPCODE_DATA:
92 DEBUGP("Data/ACK opcode\n");
94 case TFTP_OPCODE_ERROR:
95 DEBUGP("Error opcode\n");
98 DEBUGP("Unknown opcode\n");
103 static struct ip_conntrack_helper tftp[MAX_PORTS];
104 static char tftp_names[MAX_PORTS][10];
106 static void fini(void)
110 for (i = 0 ; i < ports_c; i++) {
111 DEBUGP("unregistering helper for port %d\n",
113 ip_conntrack_helper_unregister(&tftp[i]);
117 static int __init init(void)
123 ports[ports_c++] = TFTP_PORT;
125 for (i = 0; i < ports_c; i++) {
126 /* Create helper structure */
127 memset(&tftp[i], 0, sizeof(struct ip_conntrack_helper));
129 tftp[i].tuple.dst.protonum = IPPROTO_UDP;
130 tftp[i].tuple.src.u.udp.port = htons(ports[i]);
131 tftp[i].mask.dst.protonum = 0xFF;
132 tftp[i].mask.src.u.udp.port = 0xFFFF;
133 tftp[i].max_expected = 1;
134 tftp[i].timeout = 5 * 60; /* 5 minutes */
135 tftp[i].me = THIS_MODULE;
136 tftp[i].help = tftp_help;
138 tmpname = &tftp_names[i][0];
139 if (ports[i] == TFTP_PORT)
140 sprintf(tmpname, "tftp");
142 sprintf(tmpname, "tftp-%d", i);
143 tftp[i].name = tmpname;
145 DEBUGP("port #%d: %d\n", i, ports[i]);
147 ret=ip_conntrack_helper_register(&tftp[i]);
149 printk("ERROR registering helper for port %d\n",