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.
8 #include <linux/module.h>
9 #include <linux/moduleparam.h>
11 #include <linux/udp.h>
13 #include <net/netfilter/nf_conntrack.h>
14 #include <net/netfilter/nf_conntrack_tuple.h>
15 #include <net/netfilter/nf_conntrack_expect.h>
16 #include <net/netfilter/nf_conntrack_ecache.h>
17 #include <net/netfilter/nf_conntrack_helper.h>
18 #include <linux/netfilter/nf_conntrack_tftp.h>
20 MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
21 MODULE_DESCRIPTION("TFTP connection tracking helper");
22 MODULE_LICENSE("GPL");
23 MODULE_ALIAS("ip_conntrack_tftp");
26 static unsigned short ports
[MAX_PORTS
];
28 module_param_array(ports
, ushort
, &ports_c
, 0400);
29 MODULE_PARM_DESC(ports
, "Port numbers of TFTP servers");
32 #define DEBUGP(format, args...) printk("%s:%s:" format, \
33 __FILE__, __FUNCTION__ , ## args)
35 #define DEBUGP(format, args...)
38 unsigned int (*nf_nat_tftp_hook
)(struct sk_buff
**pskb
,
39 enum ip_conntrack_info ctinfo
,
40 struct nf_conntrack_expect
*exp
) __read_mostly
;
41 EXPORT_SYMBOL_GPL(nf_nat_tftp_hook
);
43 static int tftp_help(struct sk_buff
**pskb
,
46 enum ip_conntrack_info ctinfo
)
48 struct tftphdr _tftph
, *tfh
;
49 struct nf_conntrack_expect
*exp
;
50 struct nf_conntrack_tuple
*tuple
;
51 unsigned int ret
= NF_ACCEPT
;
52 int family
= ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
.src
.l3num
;
53 typeof(nf_nat_tftp_hook
) nf_nat_tftp
;
55 tfh
= skb_header_pointer(*pskb
, protoff
+ sizeof(struct udphdr
),
56 sizeof(_tftph
), &_tftph
);
60 switch (ntohs(tfh
->opcode
)) {
61 case TFTP_OPCODE_READ
:
62 case TFTP_OPCODE_WRITE
:
63 /* RRQ and WRQ works the same way */
65 NF_CT_DUMP_TUPLE(&ct
->tuplehash
[IP_CT_DIR_ORIGINAL
].tuple
);
66 NF_CT_DUMP_TUPLE(&ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
);
68 exp
= nf_conntrack_expect_alloc(ct
);
71 tuple
= &ct
->tuplehash
[IP_CT_DIR_REPLY
].tuple
;
72 nf_conntrack_expect_init(exp
, family
,
73 &tuple
->src
.u3
, &tuple
->dst
.u3
,
75 NULL
, &tuple
->dst
.u
.udp
.port
);
78 NF_CT_DUMP_TUPLE(&exp
->tuple
);
79 NF_CT_DUMP_TUPLE(&exp
->mask
);
81 nf_nat_tftp
= rcu_dereference(nf_nat_tftp_hook
);
82 if (nf_nat_tftp
&& ct
->status
& IPS_NAT_MASK
)
83 ret
= nf_nat_tftp(pskb
, ctinfo
, exp
);
84 else if (nf_conntrack_expect_related(exp
) != 0)
86 nf_conntrack_expect_put(exp
);
88 case TFTP_OPCODE_DATA
:
90 DEBUGP("Data/ACK opcode\n");
92 case TFTP_OPCODE_ERROR
:
93 DEBUGP("Error opcode\n");
96 DEBUGP("Unknown opcode\n");
101 static struct nf_conntrack_helper tftp
[MAX_PORTS
][2] __read_mostly
;
102 static char tftp_names
[MAX_PORTS
][2][sizeof("tftp-65535")] __read_mostly
;
104 static void nf_conntrack_tftp_fini(void)
108 for (i
= 0; i
< ports_c
; i
++) {
109 for (j
= 0; j
< 2; j
++)
110 nf_conntrack_helper_unregister(&tftp
[i
][j
]);
114 static int __init
nf_conntrack_tftp_init(void)
120 ports
[ports_c
++] = TFTP_PORT
;
122 for (i
= 0; i
< ports_c
; i
++) {
123 memset(&tftp
[i
], 0, sizeof(tftp
[i
]));
125 tftp
[i
][0].tuple
.src
.l3num
= AF_INET
;
126 tftp
[i
][1].tuple
.src
.l3num
= AF_INET6
;
127 for (j
= 0; j
< 2; j
++) {
128 tftp
[i
][j
].tuple
.dst
.protonum
= IPPROTO_UDP
;
129 tftp
[i
][j
].tuple
.src
.u
.udp
.port
= htons(ports
[i
]);
130 tftp
[i
][j
].mask
.src
.l3num
= 0xFFFF;
131 tftp
[i
][j
].mask
.dst
.protonum
= 0xFF;
132 tftp
[i
][j
].mask
.src
.u
.udp
.port
= htons(0xFFFF);
133 tftp
[i
][j
].max_expected
= 1;
134 tftp
[i
][j
].timeout
= 5 * 60; /* 5 minutes */
135 tftp
[i
][j
].me
= THIS_MODULE
;
136 tftp
[i
][j
].help
= tftp_help
;
138 tmpname
= &tftp_names
[i
][j
][0];
139 if (ports
[i
] == TFTP_PORT
)
140 sprintf(tmpname
, "tftp");
142 sprintf(tmpname
, "tftp-%u", i
);
143 tftp
[i
][j
].name
= tmpname
;
145 ret
= nf_conntrack_helper_register(&tftp
[i
][j
]);
147 printk("nf_ct_tftp: failed to register helper "
148 "for pf: %u port: %u\n",
149 tftp
[i
][j
].tuple
.src
.l3num
, ports
[i
]);
150 nf_conntrack_tftp_fini();
158 module_init(nf_conntrack_tftp_init
);
159 module_exit(nf_conntrack_tftp_fini
);
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