]>
git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - net/ipv6/netfilter/ip6t_hbh.c
1 /* Kernel module to match Hop-by-Hop and Destination parameters. */
3 /* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
10 #include <linux/module.h>
11 #include <linux/skbuff.h>
12 #include <linux/ipv6.h>
13 #include <linux/types.h>
14 #include <net/checksum.h>
17 #include <asm/byteorder.h>
19 #include <linux/netfilter/x_tables.h>
20 #include <linux/netfilter_ipv6/ip6_tables.h>
21 #include <linux/netfilter_ipv6/ip6t_opts.h>
23 MODULE_LICENSE("GPL");
24 MODULE_DESCRIPTION("IPv6 opts match");
25 MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
26 MODULE_ALIAS("ip6t_dst");
31 #define DEBUGP(format, args...)
37 * 1 -> must drop the packet
38 * 2 -> send ICMP PARM PROB regardless and drop packet
39 * 3 -> Send ICMP if not a multicast address and drop packet
42 * 1 -> can change the routing
44 * 0 -> Pad1 (only 1 byte!)
45 * 1 -> PadN LENGTH info (total length = length + 2)
46 * C0 | 2 -> JUMBO 4 x x x x ( xxxx > 64k )
51 match(const struct sk_buff
*skb
,
52 const struct net_device
*in
,
53 const struct net_device
*out
,
54 const struct xt_match
*match
,
55 const void *matchinfo
,
60 struct ipv6_opt_hdr _optsh
, *oh
;
61 const struct ip6t_opts
*optinfo
= matchinfo
;
64 unsigned int hdrlen
= 0;
66 u8 _opttype
, *tp
= NULL
;
67 u8 _optlen
, *lp
= NULL
;
71 err
= ipv6_find_hdr(skb
, &ptr
, match
->data
, NULL
);
78 oh
= skb_header_pointer(skb
, ptr
, sizeof(_optsh
), &_optsh
);
84 hdrlen
= ipv6_optlen(oh
);
85 if (skb
->len
- ptr
< hdrlen
) {
86 /* Packet smaller than it's length field */
90 DEBUGP("IPv6 OPTS LEN %u %u ", hdrlen
, oh
->hdrlen
);
92 DEBUGP("len %02X %04X %02X ",
93 optinfo
->hdrlen
, hdrlen
,
94 (!(optinfo
->flags
& IP6T_OPTS_LEN
) ||
95 ((optinfo
->hdrlen
== hdrlen
) ^
96 !!(optinfo
->invflags
& IP6T_OPTS_INV_LEN
))));
99 (!(optinfo
->flags
& IP6T_OPTS_LEN
) ||
100 ((optinfo
->hdrlen
== hdrlen
) ^
101 !!(optinfo
->invflags
& IP6T_OPTS_INV_LEN
)));
105 if (!(optinfo
->flags
& IP6T_OPTS_OPTS
)) {
107 } else if (optinfo
->flags
& IP6T_OPTS_NSTRICT
) {
108 DEBUGP("Not strict - not implemented");
111 DEBUGP("#%d ", optinfo
->optsnr
);
112 for (temp
= 0; temp
< optinfo
->optsnr
; temp
++) {
113 /* type field exists ? */
116 tp
= skb_header_pointer(skb
, ptr
, sizeof(_opttype
),
122 if (*tp
!= (optinfo
->opts
[temp
] & 0xFF00) >> 8) {
123 DEBUGP("Tbad %02X %02X\n",
125 (optinfo
->opts
[temp
] & 0xFF00) >> 8);
134 /* length field exists ? */
137 lp
= skb_header_pointer(skb
, ptr
+ 1,
142 spec_len
= optinfo
->opts
[temp
] & 0x00FF;
144 if (spec_len
!= 0x00FF && spec_len
!= *lp
) {
145 DEBUGP("Lbad %02X %04X\n", *lp
,
156 /* Step to the next */
157 DEBUGP("len%04X \n", optlen
);
159 if ((ptr
> skb
->len
- optlen
|| hdrlen
< optlen
) &&
160 (temp
< optinfo
->optsnr
- 1)) {
161 DEBUGP("new pointer is too large! \n");
167 if (temp
== optinfo
->optsnr
)
176 /* Called when user tries to insert an entry of this type. */
178 checkentry(const char *tablename
,
180 const struct xt_match
*match
,
182 unsigned int hook_mask
)
184 const struct ip6t_opts
*optsinfo
= matchinfo
;
186 if (optsinfo
->invflags
& ~IP6T_OPTS_INV_MASK
) {
187 DEBUGP("ip6t_opts: unknown flags %X\n", optsinfo
->invflags
);
193 static struct xt_match opts_match
[] = {
198 .matchsize
= sizeof(struct ip6t_opts
),
199 .checkentry
= checkentry
,
207 .matchsize
= sizeof(struct ip6t_opts
),
208 .checkentry
= checkentry
,
210 .data
= NEXTHDR_DEST
,
214 static int __init
ip6t_hbh_init(void)
216 return xt_register_matches(opts_match
, ARRAY_SIZE(opts_match
));
219 static void __exit
ip6t_hbh_fini(void)
221 xt_unregister_matches(opts_match
, ARRAY_SIZE(opts_match
));
224 module_init(ip6t_hbh_init
);
225 module_exit(ip6t_hbh_fini
);