Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Packet matching code. | |
3 | * | |
4 | * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling | |
6b7d31fc | 5 | * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> |
1da177e4 LT |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * 19 Jan 2002 Harald Welte <laforge@gnumonks.org> | |
12 | * - increase module usage count as soon as we have rules inside | |
13 | * a table | |
14 | * 06 Jun 2002 Andras Kis-Szabo <kisza@sch.bme.hu> | |
15 | * - new extension header parser code | |
16 | */ | |
17 | #include <linux/config.h> | |
18 | #include <linux/skbuff.h> | |
19 | #include <linux/kmod.h> | |
20 | #include <linux/vmalloc.h> | |
21 | #include <linux/netdevice.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/tcp.h> | |
24 | #include <linux/udp.h> | |
25 | #include <linux/icmpv6.h> | |
1da177e4 LT |
26 | #include <net/ipv6.h> |
27 | #include <asm/uaccess.h> | |
28 | #include <asm/semaphore.h> | |
29 | #include <linux/proc_fs.h> | |
c8923c6b | 30 | #include <linux/cpumask.h> |
1da177e4 LT |
31 | |
32 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
33 | ||
34 | MODULE_LICENSE("GPL"); | |
35 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); | |
36 | MODULE_DESCRIPTION("IPv6 packet filter"); | |
37 | ||
38 | #define IPV6_HDR_LEN (sizeof(struct ipv6hdr)) | |
39 | #define IPV6_OPTHDR_LEN (sizeof(struct ipv6_opt_hdr)) | |
40 | ||
41 | /*#define DEBUG_IP_FIREWALL*/ | |
42 | /*#define DEBUG_ALLOW_ALL*/ /* Useful for remote debugging */ | |
43 | /*#define DEBUG_IP_FIREWALL_USER*/ | |
44 | ||
45 | #ifdef DEBUG_IP_FIREWALL | |
46 | #define dprintf(format, args...) printk(format , ## args) | |
47 | #else | |
48 | #define dprintf(format, args...) | |
49 | #endif | |
50 | ||
51 | #ifdef DEBUG_IP_FIREWALL_USER | |
52 | #define duprintf(format, args...) printk(format , ## args) | |
53 | #else | |
54 | #define duprintf(format, args...) | |
55 | #endif | |
56 | ||
57 | #ifdef CONFIG_NETFILTER_DEBUG | |
58 | #define IP_NF_ASSERT(x) \ | |
59 | do { \ | |
60 | if (!(x)) \ | |
61 | printk("IP_NF_ASSERT: %s:%s:%u\n", \ | |
62 | __FUNCTION__, __FILE__, __LINE__); \ | |
63 | } while(0) | |
64 | #else | |
65 | #define IP_NF_ASSERT(x) | |
66 | #endif | |
67 | #define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) | |
68 | ||
69 | static DECLARE_MUTEX(ip6t_mutex); | |
70 | ||
71 | /* Must have mutex */ | |
72 | #define ASSERT_READ_LOCK(x) IP_NF_ASSERT(down_trylock(&ip6t_mutex) != 0) | |
73 | #define ASSERT_WRITE_LOCK(x) IP_NF_ASSERT(down_trylock(&ip6t_mutex) != 0) | |
1da177e4 LT |
74 | #include <linux/netfilter_ipv4/listhelp.h> |
75 | ||
76 | #if 0 | |
77 | /* All the better to debug you with... */ | |
78 | #define static | |
79 | #define inline | |
80 | #endif | |
81 | ||
6b7d31fc | 82 | /* |
1da177e4 | 83 | We keep a set of rules for each CPU, so we can avoid write-locking |
6b7d31fc HW |
84 | them in the softirq when updating the counters and therefore |
85 | only need to read-lock in the softirq; doing a write_lock_bh() in user | |
86 | context stops packets coming through and allows user context to read | |
87 | the counters or update the rules. | |
1da177e4 LT |
88 | |
89 | To be cache friendly on SMP, we arrange them like so: | |
90 | [ n-entries ] | |
91 | ... cache-align padding ... | |
92 | [ n-entries ] | |
93 | ||
94 | Hence the start of any table is given by get_table() below. */ | |
95 | ||
96 | /* The table itself */ | |
97 | struct ip6t_table_info | |
98 | { | |
99 | /* Size per table */ | |
100 | unsigned int size; | |
101 | /* Number of entries: FIXME. --RR */ | |
102 | unsigned int number; | |
103 | /* Initial number of entries. Needed for module usage count */ | |
104 | unsigned int initial_entries; | |
105 | ||
106 | /* Entry points and underflows */ | |
107 | unsigned int hook_entry[NF_IP6_NUMHOOKS]; | |
108 | unsigned int underflow[NF_IP6_NUMHOOKS]; | |
109 | ||
110 | /* ip6t_entry tables: one per CPU */ | |
111 | char entries[0] ____cacheline_aligned; | |
112 | }; | |
113 | ||
114 | static LIST_HEAD(ip6t_target); | |
115 | static LIST_HEAD(ip6t_match); | |
116 | static LIST_HEAD(ip6t_tables); | |
117 | #define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0) | |
118 | ||
119 | #ifdef CONFIG_SMP | |
120 | #define TABLE_OFFSET(t,p) (SMP_ALIGN((t)->size)*(p)) | |
121 | #else | |
122 | #define TABLE_OFFSET(t,p) 0 | |
123 | #endif | |
124 | ||
125 | #if 0 | |
126 | #define down(x) do { printk("DOWN:%u:" #x "\n", __LINE__); down(x); } while(0) | |
127 | #define down_interruptible(x) ({ int __r; printk("DOWNi:%u:" #x "\n", __LINE__); __r = down_interruptible(x); if (__r != 0) printk("ABORT-DOWNi:%u\n", __LINE__); __r; }) | |
128 | #define up(x) do { printk("UP:%u:" #x "\n", __LINE__); up(x); } while(0) | |
129 | #endif | |
130 | ||
131 | static int ip6_masked_addrcmp(struct in6_addr addr1, struct in6_addr mask, | |
132 | struct in6_addr addr2) | |
133 | { | |
134 | int i; | |
135 | for( i = 0; i < 16; i++){ | |
136 | if((addr1.s6_addr[i] & mask.s6_addr[i]) != | |
137 | (addr2.s6_addr[i] & mask.s6_addr[i])) | |
138 | return 1; | |
139 | } | |
140 | return 0; | |
141 | } | |
142 | ||
143 | /* Check for an extension */ | |
144 | int | |
145 | ip6t_ext_hdr(u8 nexthdr) | |
146 | { | |
147 | return ( (nexthdr == IPPROTO_HOPOPTS) || | |
148 | (nexthdr == IPPROTO_ROUTING) || | |
149 | (nexthdr == IPPROTO_FRAGMENT) || | |
150 | (nexthdr == IPPROTO_ESP) || | |
151 | (nexthdr == IPPROTO_AH) || | |
152 | (nexthdr == IPPROTO_NONE) || | |
153 | (nexthdr == IPPROTO_DSTOPTS) ); | |
154 | } | |
155 | ||
156 | /* Returns whether matches rule or not. */ | |
157 | static inline int | |
158 | ip6_packet_match(const struct sk_buff *skb, | |
159 | const char *indev, | |
160 | const char *outdev, | |
161 | const struct ip6t_ip6 *ip6info, | |
162 | unsigned int *protoff, | |
163 | int *fragoff) | |
164 | { | |
165 | size_t i; | |
166 | unsigned long ret; | |
167 | const struct ipv6hdr *ipv6 = skb->nh.ipv6h; | |
168 | ||
169 | #define FWINV(bool,invflg) ((bool) ^ !!(ip6info->invflags & invflg)) | |
170 | ||
171 | if (FWINV(ip6_masked_addrcmp(ipv6->saddr,ip6info->smsk,ip6info->src), | |
172 | IP6T_INV_SRCIP) | |
173 | || FWINV(ip6_masked_addrcmp(ipv6->daddr,ip6info->dmsk,ip6info->dst), | |
174 | IP6T_INV_DSTIP)) { | |
175 | dprintf("Source or dest mismatch.\n"); | |
176 | /* | |
177 | dprintf("SRC: %u. Mask: %u. Target: %u.%s\n", ip->saddr, | |
178 | ipinfo->smsk.s_addr, ipinfo->src.s_addr, | |
179 | ipinfo->invflags & IP6T_INV_SRCIP ? " (INV)" : ""); | |
180 | dprintf("DST: %u. Mask: %u. Target: %u.%s\n", ip->daddr, | |
181 | ipinfo->dmsk.s_addr, ipinfo->dst.s_addr, | |
182 | ipinfo->invflags & IP6T_INV_DSTIP ? " (INV)" : "");*/ | |
183 | return 0; | |
184 | } | |
185 | ||
186 | /* Look for ifname matches; this should unroll nicely. */ | |
187 | for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { | |
188 | ret |= (((const unsigned long *)indev)[i] | |
189 | ^ ((const unsigned long *)ip6info->iniface)[i]) | |
190 | & ((const unsigned long *)ip6info->iniface_mask)[i]; | |
191 | } | |
192 | ||
193 | if (FWINV(ret != 0, IP6T_INV_VIA_IN)) { | |
194 | dprintf("VIA in mismatch (%s vs %s).%s\n", | |
195 | indev, ip6info->iniface, | |
196 | ip6info->invflags&IP6T_INV_VIA_IN ?" (INV)":""); | |
197 | return 0; | |
198 | } | |
199 | ||
200 | for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) { | |
201 | ret |= (((const unsigned long *)outdev)[i] | |
202 | ^ ((const unsigned long *)ip6info->outiface)[i]) | |
203 | & ((const unsigned long *)ip6info->outiface_mask)[i]; | |
204 | } | |
205 | ||
206 | if (FWINV(ret != 0, IP6T_INV_VIA_OUT)) { | |
207 | dprintf("VIA out mismatch (%s vs %s).%s\n", | |
208 | outdev, ip6info->outiface, | |
209 | ip6info->invflags&IP6T_INV_VIA_OUT ?" (INV)":""); | |
210 | return 0; | |
211 | } | |
212 | ||
213 | /* ... might want to do something with class and flowlabel here ... */ | |
214 | ||
215 | /* look for the desired protocol header */ | |
216 | if((ip6info->flags & IP6T_F_PROTO)) { | |
217 | u_int8_t currenthdr = ipv6->nexthdr; | |
218 | struct ipv6_opt_hdr _hdr, *hp; | |
219 | u_int16_t ptr; /* Header offset in skb */ | |
220 | u_int16_t hdrlen; /* Header */ | |
221 | u_int16_t _fragoff = 0, *fp = NULL; | |
222 | ||
223 | ptr = IPV6_HDR_LEN; | |
224 | ||
225 | while (ip6t_ext_hdr(currenthdr)) { | |
226 | /* Is there enough space for the next ext header? */ | |
227 | if (skb->len - ptr < IPV6_OPTHDR_LEN) | |
228 | return 0; | |
229 | ||
230 | /* NONE or ESP: there isn't protocol part */ | |
231 | /* If we want to count these packets in '-p all', | |
232 | * we will change the return 0 to 1*/ | |
233 | if ((currenthdr == IPPROTO_NONE) || | |
234 | (currenthdr == IPPROTO_ESP)) | |
235 | break; | |
236 | ||
237 | hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr); | |
238 | BUG_ON(hp == NULL); | |
239 | ||
240 | /* Size calculation */ | |
241 | if (currenthdr == IPPROTO_FRAGMENT) { | |
242 | fp = skb_header_pointer(skb, | |
243 | ptr+offsetof(struct frag_hdr, | |
244 | frag_off), | |
245 | sizeof(_fragoff), | |
246 | &_fragoff); | |
247 | if (fp == NULL) | |
248 | return 0; | |
249 | ||
250 | _fragoff = ntohs(*fp) & ~0x7; | |
251 | hdrlen = 8; | |
252 | } else if (currenthdr == IPPROTO_AH) | |
253 | hdrlen = (hp->hdrlen+2)<<2; | |
254 | else | |
255 | hdrlen = ipv6_optlen(hp); | |
256 | ||
257 | currenthdr = hp->nexthdr; | |
258 | ptr += hdrlen; | |
259 | /* ptr is too large */ | |
260 | if ( ptr > skb->len ) | |
261 | return 0; | |
262 | if (_fragoff) { | |
263 | if (ip6t_ext_hdr(currenthdr)) | |
264 | return 0; | |
265 | break; | |
266 | } | |
267 | } | |
268 | ||
269 | *protoff = ptr; | |
270 | *fragoff = _fragoff; | |
271 | ||
272 | /* currenthdr contains the protocol header */ | |
273 | ||
274 | dprintf("Packet protocol %hi ?= %s%hi.\n", | |
275 | currenthdr, | |
276 | ip6info->invflags & IP6T_INV_PROTO ? "!":"", | |
277 | ip6info->proto); | |
278 | ||
279 | if (ip6info->proto == currenthdr) { | |
280 | if(ip6info->invflags & IP6T_INV_PROTO) { | |
281 | return 0; | |
282 | } | |
283 | return 1; | |
284 | } | |
285 | ||
286 | /* We need match for the '-p all', too! */ | |
287 | if ((ip6info->proto != 0) && | |
288 | !(ip6info->invflags & IP6T_INV_PROTO)) | |
289 | return 0; | |
290 | } | |
291 | return 1; | |
292 | } | |
293 | ||
294 | /* should be ip6 safe */ | |
295 | static inline int | |
296 | ip6_checkentry(const struct ip6t_ip6 *ipv6) | |
297 | { | |
298 | if (ipv6->flags & ~IP6T_F_MASK) { | |
299 | duprintf("Unknown flag bits set: %08X\n", | |
300 | ipv6->flags & ~IP6T_F_MASK); | |
301 | return 0; | |
302 | } | |
303 | if (ipv6->invflags & ~IP6T_INV_MASK) { | |
304 | duprintf("Unknown invflag bits set: %08X\n", | |
305 | ipv6->invflags & ~IP6T_INV_MASK); | |
306 | return 0; | |
307 | } | |
308 | return 1; | |
309 | } | |
310 | ||
311 | static unsigned int | |
312 | ip6t_error(struct sk_buff **pskb, | |
313 | const struct net_device *in, | |
314 | const struct net_device *out, | |
315 | unsigned int hooknum, | |
316 | const void *targinfo, | |
317 | void *userinfo) | |
318 | { | |
319 | if (net_ratelimit()) | |
320 | printk("ip6_tables: error: `%s'\n", (char *)targinfo); | |
321 | ||
322 | return NF_DROP; | |
323 | } | |
324 | ||
325 | static inline | |
326 | int do_match(struct ip6t_entry_match *m, | |
327 | const struct sk_buff *skb, | |
328 | const struct net_device *in, | |
329 | const struct net_device *out, | |
330 | int offset, | |
331 | unsigned int protoff, | |
332 | int *hotdrop) | |
333 | { | |
334 | /* Stop iteration if it doesn't match */ | |
335 | if (!m->u.kernel.match->match(skb, in, out, m->data, | |
336 | offset, protoff, hotdrop)) | |
337 | return 1; | |
338 | else | |
339 | return 0; | |
340 | } | |
341 | ||
342 | static inline struct ip6t_entry * | |
343 | get_entry(void *base, unsigned int offset) | |
344 | { | |
345 | return (struct ip6t_entry *)(base + offset); | |
346 | } | |
347 | ||
348 | /* Returns one of the generic firewall policies, like NF_ACCEPT. */ | |
349 | unsigned int | |
350 | ip6t_do_table(struct sk_buff **pskb, | |
351 | unsigned int hook, | |
352 | const struct net_device *in, | |
353 | const struct net_device *out, | |
354 | struct ip6t_table *table, | |
355 | void *userdata) | |
356 | { | |
6b7d31fc | 357 | static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); |
1da177e4 LT |
358 | int offset = 0; |
359 | unsigned int protoff = 0; | |
360 | int hotdrop = 0; | |
361 | /* Initializing verdict to NF_DROP keeps gcc happy. */ | |
362 | unsigned int verdict = NF_DROP; | |
363 | const char *indev, *outdev; | |
364 | void *table_base; | |
365 | struct ip6t_entry *e, *back; | |
366 | ||
367 | /* Initialization */ | |
368 | indev = in ? in->name : nulldevname; | |
369 | outdev = out ? out->name : nulldevname; | |
1da177e4 LT |
370 | /* We handle fragments by dealing with the first fragment as |
371 | * if it was a normal packet. All other fragments are treated | |
372 | * normally, except that they will NEVER match rules that ask | |
373 | * things we don't know, ie. tcp syn flag or ports). If the | |
374 | * rule is also a fragment-specific rule, non-fragments won't | |
375 | * match it. */ | |
376 | ||
377 | read_lock_bh(&table->lock); | |
378 | IP_NF_ASSERT(table->valid_hooks & (1 << hook)); | |
379 | table_base = (void *)table->private->entries | |
380 | + TABLE_OFFSET(table->private, smp_processor_id()); | |
381 | e = get_entry(table_base, table->private->hook_entry[hook]); | |
382 | ||
383 | #ifdef CONFIG_NETFILTER_DEBUG | |
384 | /* Check noone else using our table */ | |
385 | if (((struct ip6t_entry *)table_base)->comefrom != 0xdead57ac | |
386 | && ((struct ip6t_entry *)table_base)->comefrom != 0xeeeeeeec) { | |
387 | printk("ASSERT: CPU #%u, %s comefrom(%p) = %X\n", | |
388 | smp_processor_id(), | |
389 | table->name, | |
390 | &((struct ip6t_entry *)table_base)->comefrom, | |
391 | ((struct ip6t_entry *)table_base)->comefrom); | |
392 | } | |
393 | ((struct ip6t_entry *)table_base)->comefrom = 0x57acc001; | |
394 | #endif | |
395 | ||
396 | /* For return from builtin chain */ | |
397 | back = get_entry(table_base, table->private->underflow[hook]); | |
398 | ||
399 | do { | |
400 | IP_NF_ASSERT(e); | |
401 | IP_NF_ASSERT(back); | |
1da177e4 LT |
402 | if (ip6_packet_match(*pskb, indev, outdev, &e->ipv6, |
403 | &protoff, &offset)) { | |
404 | struct ip6t_entry_target *t; | |
405 | ||
406 | if (IP6T_MATCH_ITERATE(e, do_match, | |
407 | *pskb, in, out, | |
408 | offset, protoff, &hotdrop) != 0) | |
409 | goto no_match; | |
410 | ||
411 | ADD_COUNTER(e->counters, | |
412 | ntohs((*pskb)->nh.ipv6h->payload_len) | |
413 | + IPV6_HDR_LEN, | |
414 | 1); | |
415 | ||
416 | t = ip6t_get_target(e); | |
417 | IP_NF_ASSERT(t->u.kernel.target); | |
418 | /* Standard target? */ | |
419 | if (!t->u.kernel.target->target) { | |
420 | int v; | |
421 | ||
422 | v = ((struct ip6t_standard_target *)t)->verdict; | |
423 | if (v < 0) { | |
424 | /* Pop from stack? */ | |
425 | if (v != IP6T_RETURN) { | |
426 | verdict = (unsigned)(-v) - 1; | |
427 | break; | |
428 | } | |
429 | e = back; | |
430 | back = get_entry(table_base, | |
431 | back->comefrom); | |
432 | continue; | |
433 | } | |
05465343 PM |
434 | if (table_base + v != (void *)e + e->next_offset |
435 | && !(e->ipv6.flags & IP6T_F_GOTO)) { | |
1da177e4 LT |
436 | /* Save old back ptr in next entry */ |
437 | struct ip6t_entry *next | |
438 | = (void *)e + e->next_offset; | |
439 | next->comefrom | |
440 | = (void *)back - table_base; | |
441 | /* set back pointer to next entry */ | |
442 | back = next; | |
443 | } | |
444 | ||
445 | e = get_entry(table_base, v); | |
446 | } else { | |
447 | /* Targets which reenter must return | |
448 | abs. verdicts */ | |
449 | #ifdef CONFIG_NETFILTER_DEBUG | |
450 | ((struct ip6t_entry *)table_base)->comefrom | |
451 | = 0xeeeeeeec; | |
452 | #endif | |
453 | verdict = t->u.kernel.target->target(pskb, | |
454 | in, out, | |
455 | hook, | |
456 | t->data, | |
457 | userdata); | |
458 | ||
459 | #ifdef CONFIG_NETFILTER_DEBUG | |
460 | if (((struct ip6t_entry *)table_base)->comefrom | |
461 | != 0xeeeeeeec | |
462 | && verdict == IP6T_CONTINUE) { | |
463 | printk("Target %s reentered!\n", | |
464 | t->u.kernel.target->name); | |
465 | verdict = NF_DROP; | |
466 | } | |
467 | ((struct ip6t_entry *)table_base)->comefrom | |
468 | = 0x57acc001; | |
469 | #endif | |
470 | if (verdict == IP6T_CONTINUE) | |
471 | e = (void *)e + e->next_offset; | |
472 | else | |
473 | /* Verdict */ | |
474 | break; | |
475 | } | |
476 | } else { | |
477 | ||
478 | no_match: | |
479 | e = (void *)e + e->next_offset; | |
480 | } | |
481 | } while (!hotdrop); | |
482 | ||
483 | #ifdef CONFIG_NETFILTER_DEBUG | |
484 | ((struct ip6t_entry *)table_base)->comefrom = 0xdead57ac; | |
485 | #endif | |
486 | read_unlock_bh(&table->lock); | |
487 | ||
488 | #ifdef DEBUG_ALLOW_ALL | |
489 | return NF_ACCEPT; | |
490 | #else | |
491 | if (hotdrop) | |
492 | return NF_DROP; | |
493 | else return verdict; | |
494 | #endif | |
495 | } | |
496 | ||
6b7d31fc HW |
497 | /* |
498 | * These are weird, but module loading must not be done with mutex | |
499 | * held (since they will register), and we have to have a single | |
500 | * function to use try_then_request_module(). | |
501 | */ | |
502 | ||
503 | /* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */ | |
504 | static inline struct ip6t_table *find_table_lock(const char *name) | |
1da177e4 | 505 | { |
6b7d31fc | 506 | struct ip6t_table *t; |
1da177e4 | 507 | |
6b7d31fc HW |
508 | if (down_interruptible(&ip6t_mutex) != 0) |
509 | return ERR_PTR(-EINTR); | |
1da177e4 | 510 | |
6b7d31fc HW |
511 | list_for_each_entry(t, &ip6t_tables, list) |
512 | if (strcmp(t->name, name) == 0 && try_module_get(t->me)) | |
513 | return t; | |
514 | up(&ip6t_mutex); | |
515 | return NULL; | |
516 | } | |
1da177e4 | 517 | |
6b7d31fc HW |
518 | /* Find match, grabs ref. Returns ERR_PTR() on error. */ |
519 | static inline struct ip6t_match *find_match(const char *name, u8 revision) | |
520 | { | |
521 | struct ip6t_match *m; | |
522 | int err = 0; | |
523 | ||
524 | if (down_interruptible(&ip6t_mutex) != 0) | |
525 | return ERR_PTR(-EINTR); | |
526 | ||
527 | list_for_each_entry(m, &ip6t_match, list) { | |
528 | if (strcmp(m->name, name) == 0) { | |
529 | if (m->revision == revision) { | |
530 | if (try_module_get(m->me)) { | |
531 | up(&ip6t_mutex); | |
532 | return m; | |
533 | } | |
534 | } else | |
535 | err = -EPROTOTYPE; /* Found something. */ | |
536 | } | |
1da177e4 | 537 | } |
6b7d31fc HW |
538 | up(&ip6t_mutex); |
539 | return ERR_PTR(err); | |
1da177e4 LT |
540 | } |
541 | ||
6b7d31fc HW |
542 | /* Find target, grabs ref. Returns ERR_PTR() on error. */ |
543 | static inline struct ip6t_target *find_target(const char *name, u8 revision) | |
1da177e4 | 544 | { |
6b7d31fc HW |
545 | struct ip6t_target *t; |
546 | int err = 0; | |
547 | ||
548 | if (down_interruptible(&ip6t_mutex) != 0) | |
549 | return ERR_PTR(-EINTR); | |
550 | ||
551 | list_for_each_entry(t, &ip6t_target, list) { | |
552 | if (strcmp(t->name, name) == 0) { | |
553 | if (t->revision == revision) { | |
554 | if (try_module_get(t->me)) { | |
555 | up(&ip6t_mutex); | |
556 | return t; | |
557 | } | |
558 | } else | |
559 | err = -EPROTOTYPE; /* Found something. */ | |
560 | } | |
1da177e4 | 561 | } |
6b7d31fc HW |
562 | up(&ip6t_mutex); |
563 | return ERR_PTR(err); | |
564 | } | |
1da177e4 | 565 | |
6b7d31fc HW |
566 | struct ip6t_target *ip6t_find_target(const char *name, u8 revision) |
567 | { | |
568 | struct ip6t_target *target; | |
569 | ||
570 | target = try_then_request_module(find_target(name, revision), | |
571 | "ip6t_%s", name); | |
572 | if (IS_ERR(target) || !target) | |
573 | return NULL; | |
574 | return target; | |
1da177e4 | 575 | } |
1da177e4 | 576 | |
6b7d31fc | 577 | static int match_revfn(const char *name, u8 revision, int *bestp) |
1da177e4 | 578 | { |
6b7d31fc HW |
579 | struct ip6t_match *m; |
580 | int have_rev = 0; | |
581 | ||
582 | list_for_each_entry(m, &ip6t_match, list) { | |
583 | if (strcmp(m->name, name) == 0) { | |
584 | if (m->revision > *bestp) | |
585 | *bestp = m->revision; | |
586 | if (m->revision == revision) | |
587 | have_rev = 1; | |
588 | } | |
589 | } | |
590 | return have_rev; | |
1da177e4 LT |
591 | } |
592 | ||
6b7d31fc | 593 | static int target_revfn(const char *name, u8 revision, int *bestp) |
1da177e4 | 594 | { |
6b7d31fc HW |
595 | struct ip6t_target *t; |
596 | int have_rev = 0; | |
597 | ||
598 | list_for_each_entry(t, &ip6t_target, list) { | |
599 | if (strcmp(t->name, name) == 0) { | |
600 | if (t->revision > *bestp) | |
601 | *bestp = t->revision; | |
602 | if (t->revision == revision) | |
603 | have_rev = 1; | |
604 | } | |
605 | } | |
606 | return have_rev; | |
1da177e4 LT |
607 | } |
608 | ||
6b7d31fc HW |
609 | /* Returns true or fals (if no such extension at all) */ |
610 | static inline int find_revision(const char *name, u8 revision, | |
611 | int (*revfn)(const char *, u8, int *), | |
612 | int *err) | |
1da177e4 | 613 | { |
6b7d31fc HW |
614 | int have_rev, best = -1; |
615 | ||
616 | if (down_interruptible(&ip6t_mutex) != 0) { | |
617 | *err = -EINTR; | |
618 | return 1; | |
619 | } | |
620 | have_rev = revfn(name, revision, &best); | |
621 | up(&ip6t_mutex); | |
622 | ||
623 | /* Nothing at all? Return 0 to try loading module. */ | |
624 | if (best == -1) { | |
625 | *err = -ENOENT; | |
626 | return 0; | |
627 | } | |
628 | ||
629 | *err = best; | |
630 | if (!have_rev) | |
631 | *err = -EPROTONOSUPPORT; | |
632 | return 1; | |
1da177e4 LT |
633 | } |
634 | ||
6b7d31fc | 635 | |
1da177e4 LT |
636 | /* All zeroes == unconditional rule. */ |
637 | static inline int | |
638 | unconditional(const struct ip6t_ip6 *ipv6) | |
639 | { | |
640 | unsigned int i; | |
641 | ||
642 | for (i = 0; i < sizeof(*ipv6); i++) | |
643 | if (((char *)ipv6)[i]) | |
644 | break; | |
645 | ||
646 | return (i == sizeof(*ipv6)); | |
647 | } | |
648 | ||
649 | /* Figures out from what hook each rule can be called: returns 0 if | |
650 | there are loops. Puts hook bitmask in comefrom. */ | |
651 | static int | |
652 | mark_source_chains(struct ip6t_table_info *newinfo, unsigned int valid_hooks) | |
653 | { | |
654 | unsigned int hook; | |
655 | ||
656 | /* No recursion; use packet counter to save back ptrs (reset | |
657 | to 0 as we leave), and comefrom to save source hook bitmask */ | |
658 | for (hook = 0; hook < NF_IP6_NUMHOOKS; hook++) { | |
659 | unsigned int pos = newinfo->hook_entry[hook]; | |
660 | struct ip6t_entry *e | |
661 | = (struct ip6t_entry *)(newinfo->entries + pos); | |
662 | ||
663 | if (!(valid_hooks & (1 << hook))) | |
664 | continue; | |
665 | ||
666 | /* Set initial back pointer. */ | |
667 | e->counters.pcnt = pos; | |
668 | ||
669 | for (;;) { | |
670 | struct ip6t_standard_target *t | |
671 | = (void *)ip6t_get_target(e); | |
672 | ||
673 | if (e->comefrom & (1 << NF_IP6_NUMHOOKS)) { | |
674 | printk("iptables: loop hook %u pos %u %08X.\n", | |
675 | hook, pos, e->comefrom); | |
676 | return 0; | |
677 | } | |
678 | e->comefrom | |
679 | |= ((1 << hook) | (1 << NF_IP6_NUMHOOKS)); | |
680 | ||
681 | /* Unconditional return/END. */ | |
682 | if (e->target_offset == sizeof(struct ip6t_entry) | |
683 | && (strcmp(t->target.u.user.name, | |
684 | IP6T_STANDARD_TARGET) == 0) | |
685 | && t->verdict < 0 | |
686 | && unconditional(&e->ipv6)) { | |
687 | unsigned int oldpos, size; | |
688 | ||
689 | /* Return: backtrack through the last | |
690 | big jump. */ | |
691 | do { | |
692 | e->comefrom ^= (1<<NF_IP6_NUMHOOKS); | |
693 | #ifdef DEBUG_IP_FIREWALL_USER | |
694 | if (e->comefrom | |
695 | & (1 << NF_IP6_NUMHOOKS)) { | |
696 | duprintf("Back unset " | |
697 | "on hook %u " | |
698 | "rule %u\n", | |
699 | hook, pos); | |
700 | } | |
701 | #endif | |
702 | oldpos = pos; | |
703 | pos = e->counters.pcnt; | |
704 | e->counters.pcnt = 0; | |
705 | ||
706 | /* We're at the start. */ | |
707 | if (pos == oldpos) | |
708 | goto next; | |
709 | ||
710 | e = (struct ip6t_entry *) | |
711 | (newinfo->entries + pos); | |
712 | } while (oldpos == pos + e->next_offset); | |
713 | ||
714 | /* Move along one */ | |
715 | size = e->next_offset; | |
716 | e = (struct ip6t_entry *) | |
717 | (newinfo->entries + pos + size); | |
718 | e->counters.pcnt = pos; | |
719 | pos += size; | |
720 | } else { | |
721 | int newpos = t->verdict; | |
722 | ||
723 | if (strcmp(t->target.u.user.name, | |
724 | IP6T_STANDARD_TARGET) == 0 | |
725 | && newpos >= 0) { | |
726 | /* This a jump; chase it. */ | |
727 | duprintf("Jump rule %u -> %u\n", | |
728 | pos, newpos); | |
729 | } else { | |
730 | /* ... this is a fallthru */ | |
731 | newpos = pos + e->next_offset; | |
732 | } | |
733 | e = (struct ip6t_entry *) | |
734 | (newinfo->entries + newpos); | |
735 | e->counters.pcnt = pos; | |
736 | pos = newpos; | |
737 | } | |
738 | } | |
739 | next: | |
740 | duprintf("Finished chain %u\n", hook); | |
741 | } | |
742 | return 1; | |
743 | } | |
744 | ||
745 | static inline int | |
746 | cleanup_match(struct ip6t_entry_match *m, unsigned int *i) | |
747 | { | |
748 | if (i && (*i)-- == 0) | |
749 | return 1; | |
750 | ||
751 | if (m->u.kernel.match->destroy) | |
752 | m->u.kernel.match->destroy(m->data, | |
753 | m->u.match_size - sizeof(*m)); | |
754 | module_put(m->u.kernel.match->me); | |
755 | return 0; | |
756 | } | |
757 | ||
758 | static inline int | |
759 | standard_check(const struct ip6t_entry_target *t, | |
760 | unsigned int max_offset) | |
761 | { | |
762 | struct ip6t_standard_target *targ = (void *)t; | |
763 | ||
764 | /* Check standard info. */ | |
765 | if (t->u.target_size | |
766 | != IP6T_ALIGN(sizeof(struct ip6t_standard_target))) { | |
767 | duprintf("standard_check: target size %u != %u\n", | |
768 | t->u.target_size, | |
769 | IP6T_ALIGN(sizeof(struct ip6t_standard_target))); | |
770 | return 0; | |
771 | } | |
772 | ||
773 | if (targ->verdict >= 0 | |
774 | && targ->verdict > max_offset - sizeof(struct ip6t_entry)) { | |
775 | duprintf("ip6t_standard_check: bad verdict (%i)\n", | |
776 | targ->verdict); | |
777 | return 0; | |
778 | } | |
779 | ||
780 | if (targ->verdict < -NF_MAX_VERDICT - 1) { | |
781 | duprintf("ip6t_standard_check: bad negative verdict (%i)\n", | |
782 | targ->verdict); | |
783 | return 0; | |
784 | } | |
785 | return 1; | |
786 | } | |
787 | ||
788 | static inline int | |
789 | check_match(struct ip6t_entry_match *m, | |
790 | const char *name, | |
791 | const struct ip6t_ip6 *ipv6, | |
792 | unsigned int hookmask, | |
793 | unsigned int *i) | |
794 | { | |
1da177e4 LT |
795 | struct ip6t_match *match; |
796 | ||
6b7d31fc HW |
797 | match = try_then_request_module(find_match(m->u.user.name, |
798 | m->u.user.revision), | |
799 | "ip6t_%s", m->u.user.name); | |
800 | if (IS_ERR(match) || !match) { | |
801 | duprintf("check_match: `%s' not found\n", m->u.user.name); | |
802 | return match ? PTR_ERR(match) : -ENOENT; | |
1da177e4 LT |
803 | } |
804 | m->u.kernel.match = match; | |
1da177e4 LT |
805 | |
806 | if (m->u.kernel.match->checkentry | |
807 | && !m->u.kernel.match->checkentry(name, ipv6, m->data, | |
808 | m->u.match_size - sizeof(*m), | |
809 | hookmask)) { | |
810 | module_put(m->u.kernel.match->me); | |
811 | duprintf("ip_tables: check failed for `%s'.\n", | |
812 | m->u.kernel.match->name); | |
813 | return -EINVAL; | |
814 | } | |
815 | ||
816 | (*i)++; | |
817 | return 0; | |
818 | } | |
819 | ||
820 | static struct ip6t_target ip6t_standard_target; | |
821 | ||
822 | static inline int | |
823 | check_entry(struct ip6t_entry *e, const char *name, unsigned int size, | |
824 | unsigned int *i) | |
825 | { | |
826 | struct ip6t_entry_target *t; | |
827 | struct ip6t_target *target; | |
828 | int ret; | |
829 | unsigned int j; | |
830 | ||
831 | if (!ip6_checkentry(&e->ipv6)) { | |
832 | duprintf("ip_tables: ip check failed %p %s.\n", e, name); | |
833 | return -EINVAL; | |
834 | } | |
835 | ||
836 | j = 0; | |
837 | ret = IP6T_MATCH_ITERATE(e, check_match, name, &e->ipv6, e->comefrom, &j); | |
838 | if (ret != 0) | |
839 | goto cleanup_matches; | |
840 | ||
841 | t = ip6t_get_target(e); | |
6b7d31fc HW |
842 | target = try_then_request_module(find_target(t->u.user.name, |
843 | t->u.user.revision), | |
844 | "ip6t_%s", t->u.user.name); | |
845 | if (IS_ERR(target) || !target) { | |
1da177e4 | 846 | duprintf("check_entry: `%s' not found\n", t->u.user.name); |
6b7d31fc | 847 | ret = target ? PTR_ERR(target) : -ENOENT; |
1da177e4 LT |
848 | goto cleanup_matches; |
849 | } | |
850 | t->u.kernel.target = target; | |
6b7d31fc | 851 | |
1da177e4 LT |
852 | if (t->u.kernel.target == &ip6t_standard_target) { |
853 | if (!standard_check(t, size)) { | |
854 | ret = -EINVAL; | |
855 | goto cleanup_matches; | |
856 | } | |
857 | } else if (t->u.kernel.target->checkentry | |
858 | && !t->u.kernel.target->checkentry(name, e, t->data, | |
859 | t->u.target_size | |
860 | - sizeof(*t), | |
861 | e->comefrom)) { | |
862 | module_put(t->u.kernel.target->me); | |
863 | duprintf("ip_tables: check failed for `%s'.\n", | |
864 | t->u.kernel.target->name); | |
865 | ret = -EINVAL; | |
866 | goto cleanup_matches; | |
867 | } | |
868 | ||
869 | (*i)++; | |
870 | return 0; | |
871 | ||
872 | cleanup_matches: | |
873 | IP6T_MATCH_ITERATE(e, cleanup_match, &j); | |
874 | return ret; | |
875 | } | |
876 | ||
877 | static inline int | |
878 | check_entry_size_and_hooks(struct ip6t_entry *e, | |
879 | struct ip6t_table_info *newinfo, | |
880 | unsigned char *base, | |
881 | unsigned char *limit, | |
882 | const unsigned int *hook_entries, | |
883 | const unsigned int *underflows, | |
884 | unsigned int *i) | |
885 | { | |
886 | unsigned int h; | |
887 | ||
888 | if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 | |
889 | || (unsigned char *)e + sizeof(struct ip6t_entry) >= limit) { | |
890 | duprintf("Bad offset %p\n", e); | |
891 | return -EINVAL; | |
892 | } | |
893 | ||
894 | if (e->next_offset | |
895 | < sizeof(struct ip6t_entry) + sizeof(struct ip6t_entry_target)) { | |
896 | duprintf("checking: element %p size %u\n", | |
897 | e, e->next_offset); | |
898 | return -EINVAL; | |
899 | } | |
900 | ||
901 | /* Check hooks & underflows */ | |
902 | for (h = 0; h < NF_IP6_NUMHOOKS; h++) { | |
903 | if ((unsigned char *)e - base == hook_entries[h]) | |
904 | newinfo->hook_entry[h] = hook_entries[h]; | |
905 | if ((unsigned char *)e - base == underflows[h]) | |
906 | newinfo->underflow[h] = underflows[h]; | |
907 | } | |
908 | ||
909 | /* FIXME: underflows must be unconditional, standard verdicts | |
910 | < 0 (not IP6T_RETURN). --RR */ | |
911 | ||
912 | /* Clear counters and comefrom */ | |
913 | e->counters = ((struct ip6t_counters) { 0, 0 }); | |
914 | e->comefrom = 0; | |
915 | ||
916 | (*i)++; | |
917 | return 0; | |
918 | } | |
919 | ||
920 | static inline int | |
921 | cleanup_entry(struct ip6t_entry *e, unsigned int *i) | |
922 | { | |
923 | struct ip6t_entry_target *t; | |
924 | ||
925 | if (i && (*i)-- == 0) | |
926 | return 1; | |
927 | ||
928 | /* Cleanup all matches */ | |
929 | IP6T_MATCH_ITERATE(e, cleanup_match, NULL); | |
930 | t = ip6t_get_target(e); | |
931 | if (t->u.kernel.target->destroy) | |
932 | t->u.kernel.target->destroy(t->data, | |
933 | t->u.target_size - sizeof(*t)); | |
934 | module_put(t->u.kernel.target->me); | |
935 | return 0; | |
936 | } | |
937 | ||
938 | /* Checks and translates the user-supplied table segment (held in | |
939 | newinfo) */ | |
940 | static int | |
941 | translate_table(const char *name, | |
942 | unsigned int valid_hooks, | |
943 | struct ip6t_table_info *newinfo, | |
944 | unsigned int size, | |
945 | unsigned int number, | |
946 | const unsigned int *hook_entries, | |
947 | const unsigned int *underflows) | |
948 | { | |
949 | unsigned int i; | |
950 | int ret; | |
951 | ||
952 | newinfo->size = size; | |
953 | newinfo->number = number; | |
954 | ||
955 | /* Init all hooks to impossible value. */ | |
956 | for (i = 0; i < NF_IP6_NUMHOOKS; i++) { | |
957 | newinfo->hook_entry[i] = 0xFFFFFFFF; | |
958 | newinfo->underflow[i] = 0xFFFFFFFF; | |
959 | } | |
960 | ||
961 | duprintf("translate_table: size %u\n", newinfo->size); | |
962 | i = 0; | |
963 | /* Walk through entries, checking offsets. */ | |
964 | ret = IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, | |
965 | check_entry_size_and_hooks, | |
966 | newinfo, | |
967 | newinfo->entries, | |
968 | newinfo->entries + size, | |
969 | hook_entries, underflows, &i); | |
970 | if (ret != 0) | |
971 | return ret; | |
972 | ||
973 | if (i != number) { | |
974 | duprintf("translate_table: %u not %u entries\n", | |
975 | i, number); | |
976 | return -EINVAL; | |
977 | } | |
978 | ||
979 | /* Check hooks all assigned */ | |
980 | for (i = 0; i < NF_IP6_NUMHOOKS; i++) { | |
981 | /* Only hooks which are valid */ | |
982 | if (!(valid_hooks & (1 << i))) | |
983 | continue; | |
984 | if (newinfo->hook_entry[i] == 0xFFFFFFFF) { | |
985 | duprintf("Invalid hook entry %u %u\n", | |
986 | i, hook_entries[i]); | |
987 | return -EINVAL; | |
988 | } | |
989 | if (newinfo->underflow[i] == 0xFFFFFFFF) { | |
990 | duprintf("Invalid underflow %u %u\n", | |
991 | i, underflows[i]); | |
992 | return -EINVAL; | |
993 | } | |
994 | } | |
995 | ||
996 | if (!mark_source_chains(newinfo, valid_hooks)) | |
997 | return -ELOOP; | |
998 | ||
999 | /* Finally, each sanity check must pass */ | |
1000 | i = 0; | |
1001 | ret = IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, | |
1002 | check_entry, name, size, &i); | |
1003 | ||
1004 | if (ret != 0) { | |
1005 | IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, | |
1006 | cleanup_entry, &i); | |
1007 | return ret; | |
1008 | } | |
1009 | ||
1010 | /* And one copy for every other CPU */ | |
c8923c6b DM |
1011 | for_each_cpu(i) { |
1012 | if (i == 0) | |
1013 | continue; | |
1014 | memcpy(newinfo->entries + SMP_ALIGN(newinfo->size) * i, | |
1da177e4 LT |
1015 | newinfo->entries, |
1016 | SMP_ALIGN(newinfo->size)); | |
1017 | } | |
1018 | ||
1019 | return ret; | |
1020 | } | |
1021 | ||
1022 | static struct ip6t_table_info * | |
1023 | replace_table(struct ip6t_table *table, | |
1024 | unsigned int num_counters, | |
1025 | struct ip6t_table_info *newinfo, | |
1026 | int *error) | |
1027 | { | |
1028 | struct ip6t_table_info *oldinfo; | |
1029 | ||
1030 | #ifdef CONFIG_NETFILTER_DEBUG | |
1031 | { | |
1032 | struct ip6t_entry *table_base; | |
1033 | unsigned int i; | |
1034 | ||
c8923c6b | 1035 | for_each_cpu(i) { |
1da177e4 LT |
1036 | table_base = |
1037 | (void *)newinfo->entries | |
1038 | + TABLE_OFFSET(newinfo, i); | |
1039 | ||
1040 | table_base->comefrom = 0xdead57ac; | |
1041 | } | |
1042 | } | |
1043 | #endif | |
1044 | ||
1045 | /* Do the substitution. */ | |
1046 | write_lock_bh(&table->lock); | |
1047 | /* Check inside lock: is the old number correct? */ | |
1048 | if (num_counters != table->private->number) { | |
1049 | duprintf("num_counters != table->private->number (%u/%u)\n", | |
1050 | num_counters, table->private->number); | |
1051 | write_unlock_bh(&table->lock); | |
1052 | *error = -EAGAIN; | |
1053 | return NULL; | |
1054 | } | |
1055 | oldinfo = table->private; | |
1056 | table->private = newinfo; | |
1057 | newinfo->initial_entries = oldinfo->initial_entries; | |
1058 | write_unlock_bh(&table->lock); | |
1059 | ||
1060 | return oldinfo; | |
1061 | } | |
1062 | ||
1063 | /* Gets counters. */ | |
1064 | static inline int | |
1065 | add_entry_to_counter(const struct ip6t_entry *e, | |
1066 | struct ip6t_counters total[], | |
1067 | unsigned int *i) | |
1068 | { | |
1069 | ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt); | |
1070 | ||
1071 | (*i)++; | |
1072 | return 0; | |
1073 | } | |
1074 | ||
1075 | static void | |
1076 | get_counters(const struct ip6t_table_info *t, | |
1077 | struct ip6t_counters counters[]) | |
1078 | { | |
1079 | unsigned int cpu; | |
1080 | unsigned int i; | |
1081 | ||
c8923c6b | 1082 | for_each_cpu(cpu) { |
1da177e4 LT |
1083 | i = 0; |
1084 | IP6T_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu), | |
1085 | t->size, | |
1086 | add_entry_to_counter, | |
1087 | counters, | |
1088 | &i); | |
1089 | } | |
1090 | } | |
1091 | ||
1092 | static int | |
1093 | copy_entries_to_user(unsigned int total_size, | |
1094 | struct ip6t_table *table, | |
1095 | void __user *userptr) | |
1096 | { | |
1097 | unsigned int off, num, countersize; | |
1098 | struct ip6t_entry *e; | |
1099 | struct ip6t_counters *counters; | |
1100 | int ret = 0; | |
1101 | ||
1102 | /* We need atomic snapshot of counters: rest doesn't change | |
1103 | (other than comefrom, which userspace doesn't care | |
1104 | about). */ | |
1105 | countersize = sizeof(struct ip6t_counters) * table->private->number; | |
1106 | counters = vmalloc(countersize); | |
1107 | ||
1108 | if (counters == NULL) | |
1109 | return -ENOMEM; | |
1110 | ||
1111 | /* First, sum counters... */ | |
1112 | memset(counters, 0, countersize); | |
1113 | write_lock_bh(&table->lock); | |
1114 | get_counters(table->private, counters); | |
1115 | write_unlock_bh(&table->lock); | |
1116 | ||
1117 | /* ... then copy entire thing from CPU 0... */ | |
1118 | if (copy_to_user(userptr, table->private->entries, total_size) != 0) { | |
1119 | ret = -EFAULT; | |
1120 | goto free_counters; | |
1121 | } | |
1122 | ||
1123 | /* FIXME: use iterator macros --RR */ | |
1124 | /* ... then go back and fix counters and names */ | |
1125 | for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ | |
1126 | unsigned int i; | |
1127 | struct ip6t_entry_match *m; | |
1128 | struct ip6t_entry_target *t; | |
1129 | ||
1130 | e = (struct ip6t_entry *)(table->private->entries + off); | |
1131 | if (copy_to_user(userptr + off | |
1132 | + offsetof(struct ip6t_entry, counters), | |
1133 | &counters[num], | |
1134 | sizeof(counters[num])) != 0) { | |
1135 | ret = -EFAULT; | |
1136 | goto free_counters; | |
1137 | } | |
1138 | ||
1139 | for (i = sizeof(struct ip6t_entry); | |
1140 | i < e->target_offset; | |
1141 | i += m->u.match_size) { | |
1142 | m = (void *)e + i; | |
1143 | ||
1144 | if (copy_to_user(userptr + off + i | |
1145 | + offsetof(struct ip6t_entry_match, | |
1146 | u.user.name), | |
1147 | m->u.kernel.match->name, | |
1148 | strlen(m->u.kernel.match->name)+1) | |
1149 | != 0) { | |
1150 | ret = -EFAULT; | |
1151 | goto free_counters; | |
1152 | } | |
1153 | } | |
1154 | ||
1155 | t = ip6t_get_target(e); | |
1156 | if (copy_to_user(userptr + off + e->target_offset | |
1157 | + offsetof(struct ip6t_entry_target, | |
1158 | u.user.name), | |
1159 | t->u.kernel.target->name, | |
1160 | strlen(t->u.kernel.target->name)+1) != 0) { | |
1161 | ret = -EFAULT; | |
1162 | goto free_counters; | |
1163 | } | |
1164 | } | |
1165 | ||
1166 | free_counters: | |
1167 | vfree(counters); | |
1168 | return ret; | |
1169 | } | |
1170 | ||
1171 | static int | |
1172 | get_entries(const struct ip6t_get_entries *entries, | |
1173 | struct ip6t_get_entries __user *uptr) | |
1174 | { | |
1175 | int ret; | |
1176 | struct ip6t_table *t; | |
1177 | ||
6b7d31fc HW |
1178 | t = find_table_lock(entries->name); |
1179 | if (t && !IS_ERR(t)) { | |
1da177e4 LT |
1180 | duprintf("t->private->number = %u\n", |
1181 | t->private->number); | |
1182 | if (entries->size == t->private->size) | |
1183 | ret = copy_entries_to_user(t->private->size, | |
1184 | t, uptr->entrytable); | |
1185 | else { | |
1186 | duprintf("get_entries: I've got %u not %u!\n", | |
1187 | t->private->size, | |
1188 | entries->size); | |
1189 | ret = -EINVAL; | |
1190 | } | |
6b7d31fc | 1191 | module_put(t->me); |
1da177e4 LT |
1192 | up(&ip6t_mutex); |
1193 | } else | |
6b7d31fc | 1194 | ret = t ? PTR_ERR(t) : -ENOENT; |
1da177e4 LT |
1195 | |
1196 | return ret; | |
1197 | } | |
1198 | ||
1199 | static int | |
1200 | do_replace(void __user *user, unsigned int len) | |
1201 | { | |
1202 | int ret; | |
1203 | struct ip6t_replace tmp; | |
1204 | struct ip6t_table *t; | |
1205 | struct ip6t_table_info *newinfo, *oldinfo; | |
1206 | struct ip6t_counters *counters; | |
1207 | ||
1208 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) | |
1209 | return -EFAULT; | |
1210 | ||
1211 | /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ | |
1212 | if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages) | |
1213 | return -ENOMEM; | |
1214 | ||
1215 | newinfo = vmalloc(sizeof(struct ip6t_table_info) | |
c8923c6b DM |
1216 | + SMP_ALIGN(tmp.size) * |
1217 | (highest_possible_processor_id()+1)); | |
1da177e4 LT |
1218 | if (!newinfo) |
1219 | return -ENOMEM; | |
1220 | ||
1221 | if (copy_from_user(newinfo->entries, user + sizeof(tmp), | |
1222 | tmp.size) != 0) { | |
1223 | ret = -EFAULT; | |
1224 | goto free_newinfo; | |
1225 | } | |
1226 | ||
1227 | counters = vmalloc(tmp.num_counters * sizeof(struct ip6t_counters)); | |
1228 | if (!counters) { | |
1229 | ret = -ENOMEM; | |
1230 | goto free_newinfo; | |
1231 | } | |
1232 | memset(counters, 0, tmp.num_counters * sizeof(struct ip6t_counters)); | |
1233 | ||
1234 | ret = translate_table(tmp.name, tmp.valid_hooks, | |
1235 | newinfo, tmp.size, tmp.num_entries, | |
1236 | tmp.hook_entry, tmp.underflow); | |
1237 | if (ret != 0) | |
1238 | goto free_newinfo_counters; | |
1239 | ||
1240 | duprintf("ip_tables: Translated table\n"); | |
1241 | ||
6b7d31fc HW |
1242 | t = try_then_request_module(find_table_lock(tmp.name), |
1243 | "ip6table_%s", tmp.name); | |
1244 | if (!t || IS_ERR(t)) { | |
1245 | ret = t ? PTR_ERR(t) : -ENOENT; | |
1da177e4 | 1246 | goto free_newinfo_counters_untrans; |
6b7d31fc | 1247 | } |
1da177e4 LT |
1248 | |
1249 | /* You lied! */ | |
1250 | if (tmp.valid_hooks != t->valid_hooks) { | |
1251 | duprintf("Valid hook crap: %08X vs %08X\n", | |
1252 | tmp.valid_hooks, t->valid_hooks); | |
1253 | ret = -EINVAL; | |
6b7d31fc | 1254 | goto put_module; |
1da177e4 LT |
1255 | } |
1256 | ||
1257 | oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret); | |
1258 | if (!oldinfo) | |
1259 | goto put_module; | |
1260 | ||
1261 | /* Update module usage count based on number of rules */ | |
1262 | duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n", | |
1263 | oldinfo->number, oldinfo->initial_entries, newinfo->number); | |
1264 | if ((oldinfo->number > oldinfo->initial_entries) || | |
1265 | (newinfo->number <= oldinfo->initial_entries)) | |
1266 | module_put(t->me); | |
1267 | if ((oldinfo->number > oldinfo->initial_entries) && | |
1268 | (newinfo->number <= oldinfo->initial_entries)) | |
1269 | module_put(t->me); | |
1270 | ||
1271 | /* Get the old counters. */ | |
1272 | get_counters(oldinfo, counters); | |
1273 | /* Decrease module usage counts and free resource */ | |
1274 | IP6T_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL); | |
1275 | vfree(oldinfo); | |
1da177e4 LT |
1276 | if (copy_to_user(tmp.counters, counters, |
1277 | sizeof(struct ip6t_counters) * tmp.num_counters) != 0) | |
1278 | ret = -EFAULT; | |
1279 | vfree(counters); | |
1280 | up(&ip6t_mutex); | |
1281 | return ret; | |
1282 | ||
1283 | put_module: | |
1284 | module_put(t->me); | |
1da177e4 LT |
1285 | up(&ip6t_mutex); |
1286 | free_newinfo_counters_untrans: | |
1287 | IP6T_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry,NULL); | |
1288 | free_newinfo_counters: | |
1289 | vfree(counters); | |
1290 | free_newinfo: | |
1291 | vfree(newinfo); | |
1292 | return ret; | |
1293 | } | |
1294 | ||
1295 | /* We're lazy, and add to the first CPU; overflow works its fey magic | |
1296 | * and everything is OK. */ | |
1297 | static inline int | |
1298 | add_counter_to_entry(struct ip6t_entry *e, | |
1299 | const struct ip6t_counters addme[], | |
1300 | unsigned int *i) | |
1301 | { | |
1302 | #if 0 | |
1303 | duprintf("add_counter: Entry %u %lu/%lu + %lu/%lu\n", | |
1304 | *i, | |
1305 | (long unsigned int)e->counters.pcnt, | |
1306 | (long unsigned int)e->counters.bcnt, | |
1307 | (long unsigned int)addme[*i].pcnt, | |
1308 | (long unsigned int)addme[*i].bcnt); | |
1309 | #endif | |
1310 | ||
1311 | ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt); | |
1312 | ||
1313 | (*i)++; | |
1314 | return 0; | |
1315 | } | |
1316 | ||
1317 | static int | |
1318 | do_add_counters(void __user *user, unsigned int len) | |
1319 | { | |
1320 | unsigned int i; | |
1321 | struct ip6t_counters_info tmp, *paddc; | |
1322 | struct ip6t_table *t; | |
6b7d31fc | 1323 | int ret = 0; |
1da177e4 LT |
1324 | |
1325 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) | |
1326 | return -EFAULT; | |
1327 | ||
1328 | if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct ip6t_counters)) | |
1329 | return -EINVAL; | |
1330 | ||
1331 | paddc = vmalloc(len); | |
1332 | if (!paddc) | |
1333 | return -ENOMEM; | |
1334 | ||
1335 | if (copy_from_user(paddc, user, len) != 0) { | |
1336 | ret = -EFAULT; | |
1337 | goto free; | |
1338 | } | |
1339 | ||
6b7d31fc HW |
1340 | t = find_table_lock(tmp.name); |
1341 | if (!t || IS_ERR(t)) { | |
1342 | ret = t ? PTR_ERR(t) : -ENOENT; | |
1da177e4 | 1343 | goto free; |
6b7d31fc | 1344 | } |
1da177e4 LT |
1345 | |
1346 | write_lock_bh(&t->lock); | |
1347 | if (t->private->number != paddc->num_counters) { | |
1348 | ret = -EINVAL; | |
1349 | goto unlock_up_free; | |
1350 | } | |
1351 | ||
1352 | i = 0; | |
1353 | IP6T_ENTRY_ITERATE(t->private->entries, | |
1354 | t->private->size, | |
1355 | add_counter_to_entry, | |
1356 | paddc->counters, | |
1357 | &i); | |
1358 | unlock_up_free: | |
1359 | write_unlock_bh(&t->lock); | |
1360 | up(&ip6t_mutex); | |
6b7d31fc | 1361 | module_put(t->me); |
1da177e4 LT |
1362 | free: |
1363 | vfree(paddc); | |
1364 | ||
1365 | return ret; | |
1366 | } | |
1367 | ||
1368 | static int | |
1369 | do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) | |
1370 | { | |
1371 | int ret; | |
1372 | ||
1373 | if (!capable(CAP_NET_ADMIN)) | |
1374 | return -EPERM; | |
1375 | ||
1376 | switch (cmd) { | |
1377 | case IP6T_SO_SET_REPLACE: | |
1378 | ret = do_replace(user, len); | |
1379 | break; | |
1380 | ||
1381 | case IP6T_SO_SET_ADD_COUNTERS: | |
1382 | ret = do_add_counters(user, len); | |
1383 | break; | |
1384 | ||
1385 | default: | |
1386 | duprintf("do_ip6t_set_ctl: unknown request %i\n", cmd); | |
1387 | ret = -EINVAL; | |
1388 | } | |
1389 | ||
1390 | return ret; | |
1391 | } | |
1392 | ||
1393 | static int | |
1394 | do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) | |
1395 | { | |
1396 | int ret; | |
1397 | ||
1398 | if (!capable(CAP_NET_ADMIN)) | |
1399 | return -EPERM; | |
1400 | ||
1401 | switch (cmd) { | |
1402 | case IP6T_SO_GET_INFO: { | |
1403 | char name[IP6T_TABLE_MAXNAMELEN]; | |
1404 | struct ip6t_table *t; | |
1405 | ||
1406 | if (*len != sizeof(struct ip6t_getinfo)) { | |
1407 | duprintf("length %u != %u\n", *len, | |
1408 | sizeof(struct ip6t_getinfo)); | |
1409 | ret = -EINVAL; | |
1410 | break; | |
1411 | } | |
1412 | ||
1413 | if (copy_from_user(name, user, sizeof(name)) != 0) { | |
1414 | ret = -EFAULT; | |
1415 | break; | |
1416 | } | |
1417 | name[IP6T_TABLE_MAXNAMELEN-1] = '\0'; | |
6b7d31fc HW |
1418 | |
1419 | t = try_then_request_module(find_table_lock(name), | |
1420 | "ip6table_%s", name); | |
1421 | if (t && !IS_ERR(t)) { | |
1da177e4 LT |
1422 | struct ip6t_getinfo info; |
1423 | ||
1424 | info.valid_hooks = t->valid_hooks; | |
1425 | memcpy(info.hook_entry, t->private->hook_entry, | |
1426 | sizeof(info.hook_entry)); | |
1427 | memcpy(info.underflow, t->private->underflow, | |
1428 | sizeof(info.underflow)); | |
1429 | info.num_entries = t->private->number; | |
1430 | info.size = t->private->size; | |
1431 | memcpy(info.name, name, sizeof(info.name)); | |
1432 | ||
1433 | if (copy_to_user(user, &info, *len) != 0) | |
1434 | ret = -EFAULT; | |
1435 | else | |
1436 | ret = 0; | |
1da177e4 | 1437 | up(&ip6t_mutex); |
6b7d31fc HW |
1438 | module_put(t->me); |
1439 | } else | |
1440 | ret = t ? PTR_ERR(t) : -ENOENT; | |
1da177e4 LT |
1441 | } |
1442 | break; | |
1443 | ||
1444 | case IP6T_SO_GET_ENTRIES: { | |
1445 | struct ip6t_get_entries get; | |
1446 | ||
1447 | if (*len < sizeof(get)) { | |
1448 | duprintf("get_entries: %u < %u\n", *len, sizeof(get)); | |
1449 | ret = -EINVAL; | |
1450 | } else if (copy_from_user(&get, user, sizeof(get)) != 0) { | |
1451 | ret = -EFAULT; | |
1452 | } else if (*len != sizeof(struct ip6t_get_entries) + get.size) { | |
1453 | duprintf("get_entries: %u != %u\n", *len, | |
1454 | sizeof(struct ip6t_get_entries) + get.size); | |
1455 | ret = -EINVAL; | |
1456 | } else | |
1457 | ret = get_entries(&get, user); | |
1458 | break; | |
1459 | } | |
1460 | ||
6b7d31fc HW |
1461 | case IP6T_SO_GET_REVISION_MATCH: |
1462 | case IP6T_SO_GET_REVISION_TARGET: { | |
1463 | struct ip6t_get_revision rev; | |
1464 | int (*revfn)(const char *, u8, int *); | |
1465 | ||
1466 | if (*len != sizeof(rev)) { | |
1467 | ret = -EINVAL; | |
1468 | break; | |
1469 | } | |
1470 | if (copy_from_user(&rev, user, sizeof(rev)) != 0) { | |
1471 | ret = -EFAULT; | |
1472 | break; | |
1473 | } | |
1474 | ||
1475 | if (cmd == IP6T_SO_GET_REVISION_TARGET) | |
1476 | revfn = target_revfn; | |
1477 | else | |
1478 | revfn = match_revfn; | |
1479 | ||
1480 | try_then_request_module(find_revision(rev.name, rev.revision, | |
1481 | revfn, &ret), | |
1482 | "ip6t_%s", rev.name); | |
1483 | break; | |
1484 | } | |
1485 | ||
1da177e4 LT |
1486 | default: |
1487 | duprintf("do_ip6t_get_ctl: unknown request %i\n", cmd); | |
1488 | ret = -EINVAL; | |
1489 | } | |
1490 | ||
1491 | return ret; | |
1492 | } | |
1493 | ||
1494 | /* Registration hooks for targets. */ | |
1495 | int | |
1496 | ip6t_register_target(struct ip6t_target *target) | |
1497 | { | |
1498 | int ret; | |
1499 | ||
1500 | ret = down_interruptible(&ip6t_mutex); | |
1501 | if (ret != 0) | |
1502 | return ret; | |
6b7d31fc | 1503 | list_add(&target->list, &ip6t_target); |
1da177e4 LT |
1504 | up(&ip6t_mutex); |
1505 | return ret; | |
1506 | } | |
1507 | ||
1508 | void | |
1509 | ip6t_unregister_target(struct ip6t_target *target) | |
1510 | { | |
1511 | down(&ip6t_mutex); | |
1512 | LIST_DELETE(&ip6t_target, target); | |
1513 | up(&ip6t_mutex); | |
1514 | } | |
1515 | ||
1516 | int | |
1517 | ip6t_register_match(struct ip6t_match *match) | |
1518 | { | |
1519 | int ret; | |
1520 | ||
1521 | ret = down_interruptible(&ip6t_mutex); | |
1522 | if (ret != 0) | |
1523 | return ret; | |
1524 | ||
6b7d31fc | 1525 | list_add(&match->list, &ip6t_match); |
1da177e4 LT |
1526 | up(&ip6t_mutex); |
1527 | ||
1528 | return ret; | |
1529 | } | |
1530 | ||
1531 | void | |
1532 | ip6t_unregister_match(struct ip6t_match *match) | |
1533 | { | |
1534 | down(&ip6t_mutex); | |
1535 | LIST_DELETE(&ip6t_match, match); | |
1536 | up(&ip6t_mutex); | |
1537 | } | |
1538 | ||
1539 | int ip6t_register_table(struct ip6t_table *table, | |
1540 | const struct ip6t_replace *repl) | |
1541 | { | |
1542 | int ret; | |
1543 | struct ip6t_table_info *newinfo; | |
1544 | static struct ip6t_table_info bootstrap | |
1545 | = { 0, 0, 0, { 0 }, { 0 }, { } }; | |
1546 | ||
1547 | newinfo = vmalloc(sizeof(struct ip6t_table_info) | |
c8923c6b DM |
1548 | + SMP_ALIGN(repl->size) * |
1549 | (highest_possible_processor_id()+1)); | |
1da177e4 LT |
1550 | if (!newinfo) |
1551 | return -ENOMEM; | |
1552 | ||
1553 | memcpy(newinfo->entries, repl->entries, repl->size); | |
1554 | ||
1555 | ret = translate_table(table->name, table->valid_hooks, | |
1556 | newinfo, repl->size, | |
1557 | repl->num_entries, | |
1558 | repl->hook_entry, | |
1559 | repl->underflow); | |
1560 | if (ret != 0) { | |
1561 | vfree(newinfo); | |
1562 | return ret; | |
1563 | } | |
1564 | ||
1565 | ret = down_interruptible(&ip6t_mutex); | |
1566 | if (ret != 0) { | |
1567 | vfree(newinfo); | |
1568 | return ret; | |
1569 | } | |
1570 | ||
1571 | /* Don't autoload: we'd eat our tail... */ | |
1572 | if (list_named_find(&ip6t_tables, table->name)) { | |
1573 | ret = -EEXIST; | |
1574 | goto free_unlock; | |
1575 | } | |
1576 | ||
1577 | /* Simplifies replace_table code. */ | |
1578 | table->private = &bootstrap; | |
1579 | if (!replace_table(table, 0, newinfo, &ret)) | |
1580 | goto free_unlock; | |
1581 | ||
1582 | duprintf("table->private->number = %u\n", | |
1583 | table->private->number); | |
1584 | ||
1585 | /* save number of initial entries */ | |
1586 | table->private->initial_entries = table->private->number; | |
1587 | ||
1588 | rwlock_init(&table->lock); | |
1589 | list_prepend(&ip6t_tables, table); | |
1590 | ||
1591 | unlock: | |
1592 | up(&ip6t_mutex); | |
1593 | return ret; | |
1594 | ||
1595 | free_unlock: | |
1596 | vfree(newinfo); | |
1597 | goto unlock; | |
1598 | } | |
1599 | ||
1600 | void ip6t_unregister_table(struct ip6t_table *table) | |
1601 | { | |
1602 | down(&ip6t_mutex); | |
1603 | LIST_DELETE(&ip6t_tables, table); | |
1604 | up(&ip6t_mutex); | |
1605 | ||
1606 | /* Decrease module usage counts and free resources */ | |
1607 | IP6T_ENTRY_ITERATE(table->private->entries, table->private->size, | |
1608 | cleanup_entry, NULL); | |
1609 | vfree(table->private); | |
1610 | } | |
1611 | ||
1612 | /* Returns 1 if the port is matched by the range, 0 otherwise */ | |
1613 | static inline int | |
1614 | port_match(u_int16_t min, u_int16_t max, u_int16_t port, int invert) | |
1615 | { | |
1616 | int ret; | |
1617 | ||
1618 | ret = (port >= min && port <= max) ^ invert; | |
1619 | return ret; | |
1620 | } | |
1621 | ||
1622 | static int | |
1623 | tcp_find_option(u_int8_t option, | |
1624 | const struct sk_buff *skb, | |
1625 | unsigned int tcpoff, | |
1626 | unsigned int optlen, | |
1627 | int invert, | |
1628 | int *hotdrop) | |
1629 | { | |
1630 | /* tcp.doff is only 4 bits, ie. max 15 * 4 bytes */ | |
1631 | u_int8_t _opt[60 - sizeof(struct tcphdr)], *op; | |
1632 | unsigned int i; | |
1633 | ||
1634 | duprintf("tcp_match: finding option\n"); | |
1635 | if (!optlen) | |
1636 | return invert; | |
1637 | /* If we don't have the whole header, drop packet. */ | |
1638 | op = skb_header_pointer(skb, tcpoff + sizeof(struct tcphdr), optlen, | |
1639 | _opt); | |
1640 | if (op == NULL) { | |
1641 | *hotdrop = 1; | |
1642 | return 0; | |
1643 | } | |
1644 | ||
1645 | for (i = 0; i < optlen; ) { | |
1646 | if (op[i] == option) return !invert; | |
1647 | if (op[i] < 2) i++; | |
1648 | else i += op[i+1]?:1; | |
1649 | } | |
1650 | ||
1651 | return invert; | |
1652 | } | |
1653 | ||
1654 | static int | |
1655 | tcp_match(const struct sk_buff *skb, | |
1656 | const struct net_device *in, | |
1657 | const struct net_device *out, | |
1658 | const void *matchinfo, | |
1659 | int offset, | |
1660 | unsigned int protoff, | |
1661 | int *hotdrop) | |
1662 | { | |
1663 | struct tcphdr _tcph, *th; | |
1664 | const struct ip6t_tcp *tcpinfo = matchinfo; | |
1665 | ||
1666 | if (offset) { | |
1667 | /* To quote Alan: | |
1668 | ||
1669 | Don't allow a fragment of TCP 8 bytes in. Nobody normal | |
1670 | causes this. Its a cracker trying to break in by doing a | |
1671 | flag overwrite to pass the direction checks. | |
1672 | */ | |
1673 | if (offset == 1) { | |
1674 | duprintf("Dropping evil TCP offset=1 frag.\n"); | |
1675 | *hotdrop = 1; | |
1676 | } | |
1677 | /* Must not be a fragment. */ | |
1678 | return 0; | |
1679 | } | |
1680 | ||
1681 | #define FWINVTCP(bool,invflg) ((bool) ^ !!(tcpinfo->invflags & invflg)) | |
1682 | ||
1683 | th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); | |
1684 | if (th == NULL) { | |
1685 | /* We've been asked to examine this packet, and we | |
1686 | can't. Hence, no choice but to drop. */ | |
1687 | duprintf("Dropping evil TCP offset=0 tinygram.\n"); | |
1688 | *hotdrop = 1; | |
1689 | return 0; | |
1690 | } | |
1691 | ||
1692 | if (!port_match(tcpinfo->spts[0], tcpinfo->spts[1], | |
1693 | ntohs(th->source), | |
1694 | !!(tcpinfo->invflags & IP6T_TCP_INV_SRCPT))) | |
1695 | return 0; | |
1696 | if (!port_match(tcpinfo->dpts[0], tcpinfo->dpts[1], | |
1697 | ntohs(th->dest), | |
1698 | !!(tcpinfo->invflags & IP6T_TCP_INV_DSTPT))) | |
1699 | return 0; | |
1700 | if (!FWINVTCP((((unsigned char *)th)[13] & tcpinfo->flg_mask) | |
1701 | == tcpinfo->flg_cmp, | |
1702 | IP6T_TCP_INV_FLAGS)) | |
1703 | return 0; | |
1704 | if (tcpinfo->option) { | |
1705 | if (th->doff * 4 < sizeof(_tcph)) { | |
1706 | *hotdrop = 1; | |
1707 | return 0; | |
1708 | } | |
1709 | if (!tcp_find_option(tcpinfo->option, skb, protoff, | |
1710 | th->doff*4 - sizeof(*th), | |
1711 | tcpinfo->invflags & IP6T_TCP_INV_OPTION, | |
1712 | hotdrop)) | |
1713 | return 0; | |
1714 | } | |
1715 | return 1; | |
1716 | } | |
1717 | ||
1718 | /* Called when user tries to insert an entry of this type. */ | |
1719 | static int | |
1720 | tcp_checkentry(const char *tablename, | |
1721 | const struct ip6t_ip6 *ipv6, | |
1722 | void *matchinfo, | |
1723 | unsigned int matchsize, | |
1724 | unsigned int hook_mask) | |
1725 | { | |
1726 | const struct ip6t_tcp *tcpinfo = matchinfo; | |
1727 | ||
1728 | /* Must specify proto == TCP, and no unknown invflags */ | |
1729 | return ipv6->proto == IPPROTO_TCP | |
1730 | && !(ipv6->invflags & IP6T_INV_PROTO) | |
1731 | && matchsize == IP6T_ALIGN(sizeof(struct ip6t_tcp)) | |
1732 | && !(tcpinfo->invflags & ~IP6T_TCP_INV_MASK); | |
1733 | } | |
1734 | ||
1735 | static int | |
1736 | udp_match(const struct sk_buff *skb, | |
1737 | const struct net_device *in, | |
1738 | const struct net_device *out, | |
1739 | const void *matchinfo, | |
1740 | int offset, | |
1741 | unsigned int protoff, | |
1742 | int *hotdrop) | |
1743 | { | |
1744 | struct udphdr _udph, *uh; | |
1745 | const struct ip6t_udp *udpinfo = matchinfo; | |
1746 | ||
1747 | /* Must not be a fragment. */ | |
1748 | if (offset) | |
1749 | return 0; | |
1750 | ||
1751 | uh = skb_header_pointer(skb, protoff, sizeof(_udph), &_udph); | |
1752 | if (uh == NULL) { | |
1753 | /* We've been asked to examine this packet, and we | |
1754 | can't. Hence, no choice but to drop. */ | |
1755 | duprintf("Dropping evil UDP tinygram.\n"); | |
1756 | *hotdrop = 1; | |
1757 | return 0; | |
1758 | } | |
1759 | ||
1760 | return port_match(udpinfo->spts[0], udpinfo->spts[1], | |
1761 | ntohs(uh->source), | |
1762 | !!(udpinfo->invflags & IP6T_UDP_INV_SRCPT)) | |
1763 | && port_match(udpinfo->dpts[0], udpinfo->dpts[1], | |
1764 | ntohs(uh->dest), | |
1765 | !!(udpinfo->invflags & IP6T_UDP_INV_DSTPT)); | |
1766 | } | |
1767 | ||
1768 | /* Called when user tries to insert an entry of this type. */ | |
1769 | static int | |
1770 | udp_checkentry(const char *tablename, | |
1771 | const struct ip6t_ip6 *ipv6, | |
1772 | void *matchinfo, | |
1773 | unsigned int matchinfosize, | |
1774 | unsigned int hook_mask) | |
1775 | { | |
1776 | const struct ip6t_udp *udpinfo = matchinfo; | |
1777 | ||
1778 | /* Must specify proto == UDP, and no unknown invflags */ | |
1779 | if (ipv6->proto != IPPROTO_UDP || (ipv6->invflags & IP6T_INV_PROTO)) { | |
1780 | duprintf("ip6t_udp: Protocol %u != %u\n", ipv6->proto, | |
1781 | IPPROTO_UDP); | |
1782 | return 0; | |
1783 | } | |
1784 | if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_udp))) { | |
1785 | duprintf("ip6t_udp: matchsize %u != %u\n", | |
1786 | matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_udp))); | |
1787 | return 0; | |
1788 | } | |
1789 | if (udpinfo->invflags & ~IP6T_UDP_INV_MASK) { | |
1790 | duprintf("ip6t_udp: unknown flags %X\n", | |
1791 | udpinfo->invflags); | |
1792 | return 0; | |
1793 | } | |
1794 | ||
1795 | return 1; | |
1796 | } | |
1797 | ||
1798 | /* Returns 1 if the type and code is matched by the range, 0 otherwise */ | |
1799 | static inline int | |
1800 | icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, | |
1801 | u_int8_t type, u_int8_t code, | |
1802 | int invert) | |
1803 | { | |
1804 | return (type == test_type && code >= min_code && code <= max_code) | |
1805 | ^ invert; | |
1806 | } | |
1807 | ||
1808 | static int | |
1809 | icmp6_match(const struct sk_buff *skb, | |
1810 | const struct net_device *in, | |
1811 | const struct net_device *out, | |
1812 | const void *matchinfo, | |
1813 | int offset, | |
1814 | unsigned int protoff, | |
1815 | int *hotdrop) | |
1816 | { | |
1817 | struct icmp6hdr _icmp, *ic; | |
1818 | const struct ip6t_icmp *icmpinfo = matchinfo; | |
1819 | ||
1820 | /* Must not be a fragment. */ | |
1821 | if (offset) | |
1822 | return 0; | |
1823 | ||
1824 | ic = skb_header_pointer(skb, protoff, sizeof(_icmp), &_icmp); | |
1825 | if (ic == NULL) { | |
1826 | /* We've been asked to examine this packet, and we | |
1827 | can't. Hence, no choice but to drop. */ | |
1828 | duprintf("Dropping evil ICMP tinygram.\n"); | |
1829 | *hotdrop = 1; | |
1830 | return 0; | |
1831 | } | |
1832 | ||
1833 | return icmp6_type_code_match(icmpinfo->type, | |
1834 | icmpinfo->code[0], | |
1835 | icmpinfo->code[1], | |
1836 | ic->icmp6_type, ic->icmp6_code, | |
1837 | !!(icmpinfo->invflags&IP6T_ICMP_INV)); | |
1838 | } | |
1839 | ||
1840 | /* Called when user tries to insert an entry of this type. */ | |
1841 | static int | |
1842 | icmp6_checkentry(const char *tablename, | |
1843 | const struct ip6t_ip6 *ipv6, | |
1844 | void *matchinfo, | |
1845 | unsigned int matchsize, | |
1846 | unsigned int hook_mask) | |
1847 | { | |
1848 | const struct ip6t_icmp *icmpinfo = matchinfo; | |
1849 | ||
1850 | /* Must specify proto == ICMP, and no unknown invflags */ | |
1851 | return ipv6->proto == IPPROTO_ICMPV6 | |
1852 | && !(ipv6->invflags & IP6T_INV_PROTO) | |
1853 | && matchsize == IP6T_ALIGN(sizeof(struct ip6t_icmp)) | |
1854 | && !(icmpinfo->invflags & ~IP6T_ICMP_INV); | |
1855 | } | |
1856 | ||
1857 | /* The built-in targets: standard (NULL) and error. */ | |
1858 | static struct ip6t_target ip6t_standard_target = { | |
1859 | .name = IP6T_STANDARD_TARGET, | |
1860 | }; | |
1861 | ||
1862 | static struct ip6t_target ip6t_error_target = { | |
1863 | .name = IP6T_ERROR_TARGET, | |
1864 | .target = ip6t_error, | |
1865 | }; | |
1866 | ||
1867 | static struct nf_sockopt_ops ip6t_sockopts = { | |
1868 | .pf = PF_INET6, | |
1869 | .set_optmin = IP6T_BASE_CTL, | |
1870 | .set_optmax = IP6T_SO_SET_MAX+1, | |
1871 | .set = do_ip6t_set_ctl, | |
1872 | .get_optmin = IP6T_BASE_CTL, | |
1873 | .get_optmax = IP6T_SO_GET_MAX+1, | |
1874 | .get = do_ip6t_get_ctl, | |
1875 | }; | |
1876 | ||
1877 | static struct ip6t_match tcp_matchstruct = { | |
1878 | .name = "tcp", | |
1879 | .match = &tcp_match, | |
1880 | .checkentry = &tcp_checkentry, | |
1881 | }; | |
1882 | ||
1883 | static struct ip6t_match udp_matchstruct = { | |
1884 | .name = "udp", | |
1885 | .match = &udp_match, | |
1886 | .checkentry = &udp_checkentry, | |
1887 | }; | |
1888 | ||
1889 | static struct ip6t_match icmp6_matchstruct = { | |
1890 | .name = "icmp6", | |
1891 | .match = &icmp6_match, | |
1892 | .checkentry = &icmp6_checkentry, | |
1893 | }; | |
1894 | ||
1895 | #ifdef CONFIG_PROC_FS | |
1896 | static inline int print_name(const char *i, | |
1897 | off_t start_offset, char *buffer, int length, | |
1898 | off_t *pos, unsigned int *count) | |
1899 | { | |
1900 | if ((*count)++ >= start_offset) { | |
1901 | unsigned int namelen; | |
1902 | ||
1903 | namelen = sprintf(buffer + *pos, "%s\n", | |
1904 | i + sizeof(struct list_head)); | |
1905 | if (*pos + namelen > length) { | |
1906 | /* Stop iterating */ | |
1907 | return 1; | |
1908 | } | |
1909 | *pos += namelen; | |
1910 | } | |
1911 | return 0; | |
1912 | } | |
1913 | ||
1914 | static inline int print_target(const struct ip6t_target *t, | |
1915 | off_t start_offset, char *buffer, int length, | |
1916 | off_t *pos, unsigned int *count) | |
1917 | { | |
1918 | if (t == &ip6t_standard_target || t == &ip6t_error_target) | |
1919 | return 0; | |
1920 | return print_name((char *)t, start_offset, buffer, length, pos, count); | |
1921 | } | |
1922 | ||
1923 | static int ip6t_get_tables(char *buffer, char **start, off_t offset, int length) | |
1924 | { | |
1925 | off_t pos = 0; | |
1926 | unsigned int count = 0; | |
1927 | ||
1928 | if (down_interruptible(&ip6t_mutex) != 0) | |
1929 | return 0; | |
1930 | ||
1931 | LIST_FIND(&ip6t_tables, print_name, char *, | |
1932 | offset, buffer, length, &pos, &count); | |
1933 | ||
1934 | up(&ip6t_mutex); | |
1935 | ||
1936 | /* `start' hack - see fs/proc/generic.c line ~105 */ | |
1937 | *start=(char *)((unsigned long)count-offset); | |
1938 | return pos; | |
1939 | } | |
1940 | ||
1941 | static int ip6t_get_targets(char *buffer, char **start, off_t offset, int length) | |
1942 | { | |
1943 | off_t pos = 0; | |
1944 | unsigned int count = 0; | |
1945 | ||
1946 | if (down_interruptible(&ip6t_mutex) != 0) | |
1947 | return 0; | |
1948 | ||
1949 | LIST_FIND(&ip6t_target, print_target, struct ip6t_target *, | |
1950 | offset, buffer, length, &pos, &count); | |
1951 | ||
1952 | up(&ip6t_mutex); | |
1953 | ||
1954 | *start = (char *)((unsigned long)count - offset); | |
1955 | return pos; | |
1956 | } | |
1957 | ||
1958 | static int ip6t_get_matches(char *buffer, char **start, off_t offset, int length) | |
1959 | { | |
1960 | off_t pos = 0; | |
1961 | unsigned int count = 0; | |
1962 | ||
1963 | if (down_interruptible(&ip6t_mutex) != 0) | |
1964 | return 0; | |
1965 | ||
1966 | LIST_FIND(&ip6t_match, print_name, char *, | |
1967 | offset, buffer, length, &pos, &count); | |
1968 | ||
1969 | up(&ip6t_mutex); | |
1970 | ||
1971 | *start = (char *)((unsigned long)count - offset); | |
1972 | return pos; | |
1973 | } | |
1974 | ||
9b5b5cff | 1975 | static const struct { char *name; get_info_t *get_info; } ip6t_proc_entry[] = |
1da177e4 LT |
1976 | { { "ip6_tables_names", ip6t_get_tables }, |
1977 | { "ip6_tables_targets", ip6t_get_targets }, | |
1978 | { "ip6_tables_matches", ip6t_get_matches }, | |
1979 | { NULL, NULL} }; | |
1980 | #endif /*CONFIG_PROC_FS*/ | |
1981 | ||
1982 | static int __init init(void) | |
1983 | { | |
1984 | int ret; | |
1985 | ||
1986 | /* Noone else will be downing sem now, so we won't sleep */ | |
1987 | down(&ip6t_mutex); | |
1988 | list_append(&ip6t_target, &ip6t_standard_target); | |
1989 | list_append(&ip6t_target, &ip6t_error_target); | |
1990 | list_append(&ip6t_match, &tcp_matchstruct); | |
1991 | list_append(&ip6t_match, &udp_matchstruct); | |
1992 | list_append(&ip6t_match, &icmp6_matchstruct); | |
1993 | up(&ip6t_mutex); | |
1994 | ||
1995 | /* Register setsockopt */ | |
1996 | ret = nf_register_sockopt(&ip6t_sockopts); | |
1997 | if (ret < 0) { | |
1998 | duprintf("Unable to register sockopts.\n"); | |
1999 | return ret; | |
2000 | } | |
2001 | ||
2002 | #ifdef CONFIG_PROC_FS | |
2003 | { | |
2004 | struct proc_dir_entry *proc; | |
2005 | int i; | |
2006 | ||
2007 | for (i = 0; ip6t_proc_entry[i].name; i++) { | |
2008 | proc = proc_net_create(ip6t_proc_entry[i].name, 0, | |
2009 | ip6t_proc_entry[i].get_info); | |
2010 | if (!proc) { | |
2011 | while (--i >= 0) | |
2012 | proc_net_remove(ip6t_proc_entry[i].name); | |
2013 | nf_unregister_sockopt(&ip6t_sockopts); | |
2014 | return -ENOMEM; | |
2015 | } | |
2016 | proc->owner = THIS_MODULE; | |
2017 | } | |
2018 | } | |
2019 | #endif | |
2020 | ||
2021 | printk("ip6_tables: (C) 2000-2002 Netfilter core team\n"); | |
2022 | return 0; | |
2023 | } | |
2024 | ||
2025 | static void __exit fini(void) | |
2026 | { | |
2027 | nf_unregister_sockopt(&ip6t_sockopts); | |
2028 | #ifdef CONFIG_PROC_FS | |
2029 | { | |
2030 | int i; | |
2031 | for (i = 0; ip6t_proc_entry[i].name; i++) | |
2032 | proc_net_remove(ip6t_proc_entry[i].name); | |
2033 | } | |
2034 | #endif | |
2035 | } | |
2036 | ||
e674d0f3 YK |
2037 | /* |
2038 | * find specified header up to transport protocol header. | |
2039 | * If found target header, the offset to the header is set to *offset | |
2040 | * and return 0. otherwise, return -1. | |
2041 | * | |
2042 | * Notes: - non-1st Fragment Header isn't skipped. | |
2043 | * - ESP header isn't skipped. | |
2044 | * - The target header may be trancated. | |
2045 | */ | |
2046 | int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, u8 target) | |
2047 | { | |
2048 | unsigned int start = (u8*)(skb->nh.ipv6h + 1) - skb->data; | |
2049 | u8 nexthdr = skb->nh.ipv6h->nexthdr; | |
2050 | unsigned int len = skb->len - start; | |
2051 | ||
2052 | while (nexthdr != target) { | |
2053 | struct ipv6_opt_hdr _hdr, *hp; | |
2054 | unsigned int hdrlen; | |
2055 | ||
2056 | if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) | |
2057 | return -1; | |
2058 | hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr); | |
2059 | if (hp == NULL) | |
2060 | return -1; | |
2061 | if (nexthdr == NEXTHDR_FRAGMENT) { | |
2062 | unsigned short _frag_off, *fp; | |
2063 | fp = skb_header_pointer(skb, | |
2064 | start+offsetof(struct frag_hdr, | |
2065 | frag_off), | |
2066 | sizeof(_frag_off), | |
2067 | &_frag_off); | |
2068 | if (fp == NULL) | |
2069 | return -1; | |
2070 | ||
2071 | if (ntohs(*fp) & ~0x7) | |
2072 | return -1; | |
2073 | hdrlen = 8; | |
2074 | } else if (nexthdr == NEXTHDR_AUTH) | |
2075 | hdrlen = (hp->hdrlen + 2) << 2; | |
2076 | else | |
2077 | hdrlen = ipv6_optlen(hp); | |
2078 | ||
2079 | nexthdr = hp->nexthdr; | |
2080 | len -= hdrlen; | |
2081 | start += hdrlen; | |
2082 | } | |
2083 | ||
2084 | *offset = start; | |
2085 | return 0; | |
2086 | } | |
2087 | ||
1da177e4 LT |
2088 | EXPORT_SYMBOL(ip6t_register_table); |
2089 | EXPORT_SYMBOL(ip6t_unregister_table); | |
2090 | EXPORT_SYMBOL(ip6t_do_table); | |
2091 | EXPORT_SYMBOL(ip6t_register_match); | |
2092 | EXPORT_SYMBOL(ip6t_unregister_match); | |
2093 | EXPORT_SYMBOL(ip6t_register_target); | |
2094 | EXPORT_SYMBOL(ip6t_unregister_target); | |
2095 | EXPORT_SYMBOL(ip6t_ext_hdr); | |
e674d0f3 | 2096 | EXPORT_SYMBOL(ipv6_find_hdr); |
1da177e4 LT |
2097 | |
2098 | module_init(init); | |
2099 | module_exit(fini); |