]>
git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - net/ipv6/netfilter/ip6t_frag.c
1 /* Kernel module to match FRAG 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 <linux/netfilter_ipv6/ip6_tables.h>
18 #include <linux/netfilter_ipv6/ip6t_frag.h>
20 MODULE_LICENSE("GPL");
21 MODULE_DESCRIPTION("IPv6 FRAG match");
22 MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
27 #define DEBUGP(format, args...)
30 /* Returns 1 if the id is matched by the range, 0 otherwise */
32 id_match(u_int32_t min
, u_int32_t max
, u_int32_t id
, int invert
)
35 DEBUGP("frag id_match:%c 0x%x <= 0x%x <= 0x%x",invert
? '!':' ',
37 r
=(id
>= min
&& id
<= max
) ^ invert
;
38 DEBUGP(" result %s\n",r
? "PASS" : "FAILED");
43 match(const struct sk_buff
*skb
,
44 const struct net_device
*in
,
45 const struct net_device
*out
,
46 const void *matchinfo
,
51 struct frag_hdr _frag
, *fh
= NULL
;
52 const struct ip6t_frag
*fraginfo
= matchinfo
;
57 unsigned int hdrlen
= 0;
59 /* type of the 1st exthdr */
60 nexthdr
= skb
->nh
.ipv6h
->nexthdr
;
61 /* pointer to the 1st exthdr */
62 ptr
= sizeof(struct ipv6hdr
);
63 /* available length */
67 while (ip6t_ext_hdr(nexthdr
)) {
68 struct ipv6_opt_hdr _hdr
, *hp
;
70 DEBUGP("ipv6_frag header iteration \n");
72 /* Is there enough space for the next ext header? */
73 if (len
< (int)sizeof(struct ipv6_opt_hdr
))
75 /* No more exthdr -> evaluate */
76 if (nexthdr
== NEXTHDR_NONE
) {
80 if (nexthdr
== NEXTHDR_ESP
) {
84 hp
= skb_header_pointer(skb
, ptr
, sizeof(_hdr
), &_hdr
);
87 /* Calculate the header length */
88 if (nexthdr
== NEXTHDR_FRAGMENT
) {
90 } else if (nexthdr
== NEXTHDR_AUTH
)
91 hdrlen
= (hp
->hdrlen
+2)<<2;
93 hdrlen
= ipv6_optlen(hp
);
95 /* FRAG -> evaluate */
96 if (nexthdr
== NEXTHDR_FRAGMENT
) {
97 temp
|= MASK_FRAGMENT
;
105 case NEXTHDR_ROUTING
:
106 case NEXTHDR_FRAGMENT
:
111 DEBUGP("ipv6_frag match: unknown nextheader %u\n",nexthdr
);
116 nexthdr
= hp
->nexthdr
;
119 if ( ptr
> skb
->len
) {
120 DEBUGP("ipv6_frag: new pointer too large! \n");
125 /* FRAG header not found */
126 if ( temp
!= MASK_FRAGMENT
) return 0;
128 if (len
< sizeof(struct frag_hdr
)){
133 fh
= skb_header_pointer(skb
, ptr
, sizeof(_frag
), &_frag
);
136 DEBUGP("INFO %04X ", fh
->frag_off
);
137 DEBUGP("OFFSET %04X ", ntohs(fh
->frag_off
) & ~0x7);
138 DEBUGP("RES %02X %04X", fh
->reserved
, ntohs(fh
->frag_off
) & 0x6);
139 DEBUGP("MF %04X ", fh
->frag_off
& htons(IP6_MF
));
140 DEBUGP("ID %u %08X\n", ntohl(fh
->identification
),
141 ntohl(fh
->identification
));
143 DEBUGP("IPv6 FRAG id %02X ",
144 (id_match(fraginfo
->ids
[0], fraginfo
->ids
[1],
145 ntohl(fh
->identification
),
146 !!(fraginfo
->invflags
& IP6T_FRAG_INV_IDS
))));
147 DEBUGP("res %02X %02X%04X %02X ",
148 (fraginfo
->flags
& IP6T_FRAG_RES
), fh
->reserved
,
149 ntohs(fh
->frag_off
) & 0x6,
150 !((fraginfo
->flags
& IP6T_FRAG_RES
)
151 && (fh
->reserved
|| (ntohs(fh
->frag_off
) & 0x06))));
152 DEBUGP("first %02X %02X %02X ",
153 (fraginfo
->flags
& IP6T_FRAG_FST
),
154 ntohs(fh
->frag_off
) & ~0x7,
155 !((fraginfo
->flags
& IP6T_FRAG_FST
)
156 && (ntohs(fh
->frag_off
) & ~0x7)));
157 DEBUGP("mf %02X %02X %02X ",
158 (fraginfo
->flags
& IP6T_FRAG_MF
),
159 ntohs(fh
->frag_off
) & IP6_MF
,
160 !((fraginfo
->flags
& IP6T_FRAG_MF
)
161 && !((ntohs(fh
->frag_off
) & IP6_MF
))));
162 DEBUGP("last %02X %02X %02X\n",
163 (fraginfo
->flags
& IP6T_FRAG_NMF
),
164 ntohs(fh
->frag_off
) & IP6_MF
,
165 !((fraginfo
->flags
& IP6T_FRAG_NMF
)
166 && (ntohs(fh
->frag_off
) & IP6_MF
)));
170 (id_match(fraginfo
->ids
[0], fraginfo
->ids
[1],
171 ntohl(fh
->identification
),
172 !!(fraginfo
->invflags
& IP6T_FRAG_INV_IDS
)))
174 !((fraginfo
->flags
& IP6T_FRAG_RES
)
175 && (fh
->reserved
|| (ntohs(fh
->frag_off
) & 0x6)))
177 !((fraginfo
->flags
& IP6T_FRAG_FST
)
178 && (ntohs(fh
->frag_off
) & ~0x7))
180 !((fraginfo
->flags
& IP6T_FRAG_MF
)
181 && !(ntohs(fh
->frag_off
) & IP6_MF
))
183 !((fraginfo
->flags
& IP6T_FRAG_NMF
)
184 && (ntohs(fh
->frag_off
) & IP6_MF
));
187 /* Called when user tries to insert an entry of this type. */
189 checkentry(const char *tablename
,
190 const struct ip6t_ip6
*ip
,
192 unsigned int matchinfosize
,
193 unsigned int hook_mask
)
195 const struct ip6t_frag
*fraginfo
= matchinfo
;
197 if (matchinfosize
!= IP6T_ALIGN(sizeof(struct ip6t_frag
))) {
198 DEBUGP("ip6t_frag: matchsize %u != %u\n",
199 matchinfosize
, IP6T_ALIGN(sizeof(struct ip6t_frag
)));
202 if (fraginfo
->invflags
& ~IP6T_FRAG_INV_MASK
) {
203 DEBUGP("ip6t_frag: unknown flags %X\n",
211 static struct ip6t_match frag_match
= {
214 .checkentry
= &checkentry
,
218 static int __init
init(void)
220 return ip6t_register_match(&frag_match
);
223 static void __exit
cleanup(void)
225 ip6t_unregister_match(&frag_match
);
229 module_exit(cleanup
);