[PATCH] Fix breakage on ppc{,64} by "nvidiafb: Fallback to firmware EDID"
[linux-2.6.git] / net / ipv6 / netfilter / ip6t_rt.c
1 /* Kernel module to match ROUTING parameters. */
2
3 /* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
4  *
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.
8  */
9
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>
15 #include <net/ipv6.h>
16
17 #include <asm/byteorder.h>
18
19 #include <linux/netfilter_ipv6/ip6_tables.h>
20 #include <linux/netfilter_ipv6/ip6t_rt.h>
21
22 MODULE_LICENSE("GPL");
23 MODULE_DESCRIPTION("IPv6 RT match");
24 MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
25
26 #if 0
27 #define DEBUGP printk
28 #else
29 #define DEBUGP(format, args...)
30 #endif
31
32 /* Returns 1 if the id is matched by the range, 0 otherwise */
33 static inline int
34 segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, int invert)
35 {
36        int r=0;
37        DEBUGP("rt segsleft_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ',
38               min,id,max);
39        r=(id >= min && id <= max) ^ invert;
40        DEBUGP(" result %s\n",r? "PASS" : "FAILED");
41        return r;
42 }
43
44 static int
45 match(const struct sk_buff *skb,
46       const struct net_device *in,
47       const struct net_device *out,
48       const void *matchinfo,
49       int offset,
50       unsigned int protoff,
51       int *hotdrop)
52 {
53        struct ipv6_rt_hdr _route, *rh = NULL;
54        const struct ip6t_rt *rtinfo = matchinfo;
55        unsigned int temp;
56        unsigned int len;
57        u8 nexthdr;
58        unsigned int ptr;
59        unsigned int hdrlen = 0;
60        unsigned int ret = 0;
61        struct in6_addr *ap, _addr;
62
63        /* type of the 1st exthdr */
64        nexthdr = skb->nh.ipv6h->nexthdr;
65        /* pointer to the 1st exthdr */
66        ptr = sizeof(struct ipv6hdr);
67        /* available length */
68        len = skb->len - ptr;
69        temp = 0;
70
71         while (ip6t_ext_hdr(nexthdr)) {
72                struct ipv6_opt_hdr _hdr, *hp;
73
74               DEBUGP("ipv6_rt header iteration \n");
75
76               /* Is there enough space for the next ext header? */
77                 if (len < (int)sizeof(struct ipv6_opt_hdr))
78                         return 0;
79               /* No more exthdr -> evaluate */
80                 if (nexthdr == NEXTHDR_NONE) {
81                      break;
82               }
83               /* ESP -> evaluate */
84                 if (nexthdr == NEXTHDR_ESP) {
85                      break;
86               }
87
88               hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
89               BUG_ON(hp == NULL);
90
91               /* Calculate the header length */
92                 if (nexthdr == NEXTHDR_FRAGMENT) {
93                         hdrlen = 8;
94                 } else if (nexthdr == NEXTHDR_AUTH)
95                         hdrlen = (hp->hdrlen+2)<<2;
96                 else
97                         hdrlen = ipv6_optlen(hp);
98
99               /* ROUTING -> evaluate */
100                 if (nexthdr == NEXTHDR_ROUTING) {
101                      temp |= MASK_ROUTING;
102                      break;
103               }
104
105
106               /* set the flag */
107               switch (nexthdr){
108                      case NEXTHDR_HOP:
109                      case NEXTHDR_ROUTING:
110                      case NEXTHDR_FRAGMENT:
111                      case NEXTHDR_AUTH:
112                      case NEXTHDR_DEST:
113                             break;
114                      default:
115                             DEBUGP("ipv6_rt match: unknown nextheader %u\n",nexthdr);
116                             return 0;
117                             break;
118               }
119
120                 nexthdr = hp->nexthdr;
121                 len -= hdrlen;
122                 ptr += hdrlen;
123                 if ( ptr > skb->len ) {
124                         DEBUGP("ipv6_rt: new pointer is too large! \n");
125                         break;
126                 }
127         }
128
129        /* ROUTING header not found */
130        if ( temp != MASK_ROUTING ) return 0;
131
132        if (len < (int)sizeof(struct ipv6_rt_hdr)){
133                *hotdrop = 1;
134                 return 0;
135        }
136
137        if (len < hdrlen){
138                /* Pcket smaller than its length field */
139                 return 0;
140        }
141
142        rh = skb_header_pointer(skb, ptr, sizeof(_route), &_route);
143        BUG_ON(rh == NULL);
144
145        DEBUGP("IPv6 RT LEN %u %u ", hdrlen, rh->hdrlen);
146        DEBUGP("TYPE %04X ", rh->type);
147        DEBUGP("SGS_LEFT %u %02X\n", rh->segments_left, rh->segments_left);
148
149        DEBUGP("IPv6 RT segsleft %02X ",
150                 (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
151                            rh->segments_left,
152                            !!(rtinfo->invflags & IP6T_RT_INV_SGS))));
153        DEBUGP("type %02X %02X %02X ",
154                 rtinfo->rt_type, rh->type, 
155                 (!(rtinfo->flags & IP6T_RT_TYP) ||
156                            ((rtinfo->rt_type == rh->type) ^
157                            !!(rtinfo->invflags & IP6T_RT_INV_TYP))));
158        DEBUGP("len %02X %04X %02X ",
159                 rtinfo->hdrlen, hdrlen,
160                 (!(rtinfo->flags & IP6T_RT_LEN) ||
161                            ((rtinfo->hdrlen == hdrlen) ^
162                            !!(rtinfo->invflags & IP6T_RT_INV_LEN))));
163        DEBUGP("res %02X %02X %02X ", 
164                 (rtinfo->flags & IP6T_RT_RES), ((struct rt0_hdr *)rh)->bitmap,
165                 !((rtinfo->flags & IP6T_RT_RES) && (((struct rt0_hdr *)rh)->bitmap)));
166
167        ret = (rh != NULL)
168                 &&
169                 (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
170                            rh->segments_left,
171                            !!(rtinfo->invflags & IP6T_RT_INV_SGS)))
172                 &&
173                 (!(rtinfo->flags & IP6T_RT_LEN) ||
174                            ((rtinfo->hdrlen == hdrlen) ^
175                            !!(rtinfo->invflags & IP6T_RT_INV_LEN)))
176                 &&
177                 (!(rtinfo->flags & IP6T_RT_TYP) ||
178                            ((rtinfo->rt_type == rh->type) ^
179                            !!(rtinfo->invflags & IP6T_RT_INV_TYP)));
180
181         if (ret && (rtinfo->flags & IP6T_RT_RES)) {
182                 u_int32_t *bp, _bitmap;
183                 bp = skb_header_pointer(skb,
184                                         ptr + offsetof(struct rt0_hdr, bitmap),
185                                         sizeof(_bitmap), &_bitmap);
186
187                 ret = (*bp == 0);
188         }
189
190         DEBUGP("#%d ",rtinfo->addrnr);
191        if ( !(rtinfo->flags & IP6T_RT_FST) ){
192                return ret;
193         } else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) {
194                 DEBUGP("Not strict ");
195                 if ( rtinfo->addrnr > (unsigned int)((hdrlen-8)/16) ){
196                         DEBUGP("There isn't enough space\n");
197                         return 0;
198                 } else {
199                         unsigned int i = 0;
200
201                         DEBUGP("#%d ",rtinfo->addrnr);
202                         for(temp=0; temp<(unsigned int)((hdrlen-8)/16); temp++){
203                                 ap = skb_header_pointer(skb,
204                                                         ptr
205                                                         + sizeof(struct rt0_hdr)
206                                                         + temp * sizeof(_addr),
207                                                         sizeof(_addr),
208                                                         &_addr);
209
210                                 BUG_ON(ap == NULL);
211
212                                 if (ipv6_addr_equal(ap, &rtinfo->addrs[i])) {
213                                         DEBUGP("i=%d temp=%d;\n",i,temp);
214                                         i++;
215                                 }
216                                 if (i==rtinfo->addrnr) break;
217                         }
218                         DEBUGP("i=%d #%d\n", i, rtinfo->addrnr);
219                         if (i == rtinfo->addrnr)
220                                 return ret;
221                         else return 0;
222                 }
223         } else {
224                 DEBUGP("Strict ");
225                 if ( rtinfo->addrnr > (unsigned int)((hdrlen-8)/16) ){
226                         DEBUGP("There isn't enough space\n");
227                         return 0;
228                 } else {
229                         DEBUGP("#%d ",rtinfo->addrnr);
230                         for(temp=0; temp<rtinfo->addrnr; temp++){
231                                 ap = skb_header_pointer(skb,
232                                                         ptr
233                                                         + sizeof(struct rt0_hdr)
234                                                         + temp * sizeof(_addr),
235                                                         sizeof(_addr),
236                                                         &_addr);
237                                 BUG_ON(ap == NULL);
238
239                                 if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp]))
240                                         break;
241                         }
242                         DEBUGP("temp=%d #%d\n", temp, rtinfo->addrnr);
243                         if ((temp == rtinfo->addrnr) && (temp == (unsigned int)((hdrlen-8)/16)))
244                                 return ret;
245                         else return 0;
246                 }
247         }
248
249         return 0;
250 }
251
252 /* Called when user tries to insert an entry of this type. */
253 static int
254 checkentry(const char *tablename,
255           const struct ip6t_ip6 *ip,
256           void *matchinfo,
257           unsigned int matchinfosize,
258           unsigned int hook_mask)
259 {
260        const struct ip6t_rt *rtinfo = matchinfo;
261
262        if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_rt))) {
263               DEBUGP("ip6t_rt: matchsize %u != %u\n",
264                       matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_rt)));
265               return 0;
266        }
267        if (rtinfo->invflags & ~IP6T_RT_INV_MASK) {
268               DEBUGP("ip6t_rt: unknown flags %X\n",
269                       rtinfo->invflags);
270               return 0;
271        }
272        if ( (rtinfo->flags & (IP6T_RT_RES|IP6T_RT_FST_MASK)) && 
273                        (!(rtinfo->flags & IP6T_RT_TYP) || 
274                        (rtinfo->rt_type != 0) || 
275                        (rtinfo->invflags & IP6T_RT_INV_TYP)) ) {
276               DEBUGP("`--rt-type 0' required before `--rt-0-*'");
277               return 0;
278        }
279
280        return 1;
281 }
282
283 static struct ip6t_match rt_match = {
284         .name           = "rt",
285         .match          = &match,
286         .checkentry     = &checkentry,
287         .me             = THIS_MODULE,
288 };
289
290 static int __init init(void)
291 {
292        return ip6t_register_match(&rt_match);
293 }
294
295 static void __exit cleanup(void)
296 {
297        ip6t_unregister_match(&rt_match);
298 }
299
300 module_init(init);
301 module_exit(cleanup);