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netfilter: {ip,ip6,arp}_tables: dont block bottom half more than necessary
[linux-rapidio-2.6.git] / net / ipv4 / netfilter / arp_tables.c
blob6bccba31d13208d03f042002f5808c3396c1f37f
1 /*
2 * Packet matching code for ARP packets.
3 *
4 * Based heavily, if not almost entirely, upon ip_tables.c framework.
5 *
6 * Some ARP specific bits are:
7 *
8 * Copyright (C) 2002 David S. Miller (davem@redhat.com)
9 *
10 */
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 #include <linux/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/netdevice.h>
15 #include <linux/capability.h>
16 #include <linux/if_arp.h>
17 #include <linux/kmod.h>
18 #include <linux/vmalloc.h>
19 #include <linux/proc_fs.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/mutex.h>
23 #include <linux/err.h>
24 #include <net/compat.h>
25 #include <net/sock.h>
26 #include <asm/uaccess.h>
27
28 #include <linux/netfilter/x_tables.h>
29 #include <linux/netfilter_arp/arp_tables.h>
30 #include "../../netfilter/xt_repldata.h"
31
32 MODULE_LICENSE("GPL");
33 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
34 MODULE_DESCRIPTION("arptables core");
35
36 /*#define DEBUG_ARP_TABLES*/
37 /*#define DEBUG_ARP_TABLES_USER*/
38
39 #ifdef DEBUG_ARP_TABLES
40 #define dprintf(format, args...) printk(format , ## args)
41 #else
42 #define dprintf(format, args...)
43 #endif
44
45 #ifdef DEBUG_ARP_TABLES_USER
46 #define duprintf(format, args...) printk(format , ## args)
47 #else
48 #define duprintf(format, args...)
49 #endif
50
51 #ifdef CONFIG_NETFILTER_DEBUG
52 #define ARP_NF_ASSERT(x) WARN_ON(!(x))
53 #else
54 #define ARP_NF_ASSERT(x)
55 #endif
56
57 void *arpt_alloc_initial_table(const struct xt_table *info)
58 {
59 return xt_alloc_initial_table(arpt, ARPT);
60 }
61 EXPORT_SYMBOL_GPL(arpt_alloc_initial_table);
62
63 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
64 const char *hdr_addr, int len)
65 {
66 int i, ret;
67
68 if (len > ARPT_DEV_ADDR_LEN_MAX)
69 len = ARPT_DEV_ADDR_LEN_MAX;
70
71 ret = 0;
72 for (i = 0; i < len; i++)
73 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
74
75 return (ret != 0);
76 }
77
78 /*
79 * Unfortunatly, _b and _mask are not aligned to an int (or long int)
80 * Some arches dont care, unrolling the loop is a win on them.
81 * For other arches, we only have a 16bit alignement.
82 */
83 static unsigned long ifname_compare(const char *_a, const char *_b, const char *_mask)
84 {
85 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
86 unsigned long ret = ifname_compare_aligned(_a, _b, _mask);
87 #else
88 unsigned long ret = 0;
89 const u16 *a = (const u16 *)_a;
90 const u16 *b = (const u16 *)_b;
91 const u16 *mask = (const u16 *)_mask;
92 int i;
93
94 for (i = 0; i < IFNAMSIZ/sizeof(u16); i++)
95 ret |= (a[i] ^ b[i]) & mask[i];
96 #endif
97 return ret;
98 }
99
100 /* Returns whether packet matches rule or not. */
101 static inline int arp_packet_match(const struct arphdr *arphdr,
102 struct net_device *dev,
103 const char *indev,
104 const char *outdev,
105 const struct arpt_arp *arpinfo)
106 {
107 const char *arpptr = (char *)(arphdr + 1);
108 const char *src_devaddr, *tgt_devaddr;
109 __be32 src_ipaddr, tgt_ipaddr;
110 long ret;
111
112 #define FWINV(bool, invflg) ((bool) ^ !!(arpinfo->invflags & (invflg)))
113
114 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
115 ARPT_INV_ARPOP)) {
116 dprintf("ARP operation field mismatch.\n");
117 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
118 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
119 return 0;
120 }
121
122 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
123 ARPT_INV_ARPHRD)) {
124 dprintf("ARP hardware address format mismatch.\n");
125 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
126 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
127 return 0;
128 }
129
130 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
131 ARPT_INV_ARPPRO)) {
132 dprintf("ARP protocol address format mismatch.\n");
133 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
134 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
135 return 0;
136 }
137
138 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
139 ARPT_INV_ARPHLN)) {
140 dprintf("ARP hardware address length mismatch.\n");
141 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
142 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
143 return 0;
144 }
145
146 src_devaddr = arpptr;
147 arpptr += dev->addr_len;
148 memcpy(&src_ipaddr, arpptr, sizeof(u32));
149 arpptr += sizeof(u32);
150 tgt_devaddr = arpptr;
151 arpptr += dev->addr_len;
152 memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
153
154 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
155 ARPT_INV_SRCDEVADDR) ||
156 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
157 ARPT_INV_TGTDEVADDR)) {
158 dprintf("Source or target device address mismatch.\n");
159
160 return 0;
161 }
162
163 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
164 ARPT_INV_SRCIP) ||
165 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
166 ARPT_INV_TGTIP)) {
167 dprintf("Source or target IP address mismatch.\n");
168
169 dprintf("SRC: %pI4. Mask: %pI4. Target: %pI4.%s\n",
170 &src_ipaddr,
171 &arpinfo->smsk.s_addr,
172 &arpinfo->src.s_addr,
173 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
174 dprintf("TGT: %pI4 Mask: %pI4 Target: %pI4.%s\n",
175 &tgt_ipaddr,
176 &arpinfo->tmsk.s_addr,
177 &arpinfo->tgt.s_addr,
178 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
179 return 0;
180 }
181
182 /* Look for ifname matches. */
183 ret = ifname_compare(indev, arpinfo->iniface, arpinfo->iniface_mask);
184
185 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
186 dprintf("VIA in mismatch (%s vs %s).%s\n",
187 indev, arpinfo->iniface,
188 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
189 return 0;
190 }
191
192 ret = ifname_compare(outdev, arpinfo->outiface, arpinfo->outiface_mask);
193
194 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
195 dprintf("VIA out mismatch (%s vs %s).%s\n",
196 outdev, arpinfo->outiface,
197 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
198 return 0;
199 }
200
201 return 1;
202 #undef FWINV
203 }
204
205 static inline int arp_checkentry(const struct arpt_arp *arp)
206 {
207 if (arp->flags & ~ARPT_F_MASK) {
208 duprintf("Unknown flag bits set: %08X\n",
209 arp->flags & ~ARPT_F_MASK);
210 return 0;
211 }
212 if (arp->invflags & ~ARPT_INV_MASK) {
213 duprintf("Unknown invflag bits set: %08X\n",
214 arp->invflags & ~ARPT_INV_MASK);
215 return 0;
216 }
217
218 return 1;
219 }
220
221 static unsigned int
222 arpt_error(struct sk_buff *skb, const struct xt_action_param *par)
223 {
224 if (net_ratelimit())
225 pr_err("arp_tables: error: '%s'\n",
226 (const char *)par->targinfo);
227
228 return NF_DROP;
229 }
230
231 static inline const struct arpt_entry_target *
232 arpt_get_target_c(const struct arpt_entry *e)
233 {
234 return arpt_get_target((struct arpt_entry *)e);
235 }
236
237 static inline struct arpt_entry *
238 get_entry(const void *base, unsigned int offset)
239 {
240 return (struct arpt_entry *)(base + offset);
241 }
242
243 static inline __pure
244 struct arpt_entry *arpt_next_entry(const struct arpt_entry *entry)
245 {
246 return (void *)entry + entry->next_offset;
247 }
248
249 unsigned int arpt_do_table(struct sk_buff *skb,
250 unsigned int hook,
251 const struct net_device *in,
252 const struct net_device *out,
253 struct xt_table *table)
254 {
255 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long))));
256 unsigned int verdict = NF_DROP;
257 const struct arphdr *arp;
258 struct arpt_entry *e, *back;
259 const char *indev, *outdev;
260 void *table_base;
261 const struct xt_table_info *private;
262 struct xt_action_param acpar;
263
264 if (!pskb_may_pull(skb, arp_hdr_len(skb->dev)))
265 return NF_DROP;
266
267 indev = in ? in->name : nulldevname;
268 outdev = out ? out->name : nulldevname;
269
270 xt_info_rdlock_bh();
271 private = table->private;
272 table_base = private->entries[smp_processor_id()];
273
274 e = get_entry(table_base, private->hook_entry[hook]);
275 back = get_entry(table_base, private->underflow[hook]);
276
277 acpar.in = in;
278 acpar.out = out;
279 acpar.hooknum = hook;
280 acpar.family = NFPROTO_ARP;
281 acpar.hotdrop = false;
282
283 arp = arp_hdr(skb);
284 do {
285 const struct arpt_entry_target *t;
286
287 if (!arp_packet_match(arp, skb->dev, indev, outdev, &e->arp)) {
288 e = arpt_next_entry(e);
289 continue;
290 }
291
292 ADD_COUNTER(e->counters, arp_hdr_len(skb->dev), 1);
293
294 t = arpt_get_target_c(e);
295
296 /* Standard target? */
297 if (!t->u.kernel.target->target) {
298 int v;
299
300 v = ((struct arpt_standard_target *)t)->verdict;
301 if (v < 0) {
302 /* Pop from stack? */
303 if (v != ARPT_RETURN) {
304 verdict = (unsigned)(-v) - 1;
305 break;
306 }
307 e = back;
308 back = get_entry(table_base, back->comefrom);
309 continue;
310 }
311 if (table_base + v
312 != arpt_next_entry(e)) {
313 /* Save old back ptr in next entry */
314 struct arpt_entry *next = arpt_next_entry(e);
315 next->comefrom = (void *)back - table_base;
316
317 /* set back pointer to next entry */
318 back = next;
319 }
320
321 e = get_entry(table_base, v);
322 continue;
323 }
324
325 /* Targets which reenter must return
326 * abs. verdicts
327 */
328 acpar.target = t->u.kernel.target;
329 acpar.targinfo = t->data;
330 verdict = t->u.kernel.target->target(skb, &acpar);
331
332 /* Target might have changed stuff. */
333 arp = arp_hdr(skb);
334
335 if (verdict == ARPT_CONTINUE)
336 e = arpt_next_entry(e);
337 else
338 /* Verdict */
339 break;
340 } while (!acpar.hotdrop);
341 xt_info_rdunlock_bh();
342
343 if (acpar.hotdrop)
344 return NF_DROP;
345 else
346 return verdict;
347 }
348
349 /* All zeroes == unconditional rule. */
350 static inline bool unconditional(const struct arpt_arp *arp)
351 {
352 static const struct arpt_arp uncond;
353
354 return memcmp(arp, &uncond, sizeof(uncond)) == 0;
355 }
356
357 /* Figures out from what hook each rule can be called: returns 0 if
358 * there are loops. Puts hook bitmask in comefrom.
359 */
360 static int mark_source_chains(const struct xt_table_info *newinfo,
361 unsigned int valid_hooks, void *entry0)
362 {
363 unsigned int hook;
364
365 /* No recursion; use packet counter to save back ptrs (reset
366 * to 0 as we leave), and comefrom to save source hook bitmask.
367 */
368 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
369 unsigned int pos = newinfo->hook_entry[hook];
370 struct arpt_entry *e
371 = (struct arpt_entry *)(entry0 + pos);
372
373 if (!(valid_hooks & (1 << hook)))
374 continue;
375
376 /* Set initial back pointer. */
377 e->counters.pcnt = pos;
378
379 for (;;) {
380 const struct arpt_standard_target *t
381 = (void *)arpt_get_target_c(e);
382 int visited = e->comefrom & (1 << hook);
383
384 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
385 pr_notice("arptables: loop hook %u pos %u %08X.\n",
386 hook, pos, e->comefrom);
387 return 0;
388 }
389 e->comefrom
390 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
391
392 /* Unconditional return/END. */
393 if ((e->target_offset == sizeof(struct arpt_entry) &&
394 (strcmp(t->target.u.user.name,
395 ARPT_STANDARD_TARGET) == 0) &&
396 t->verdict < 0 && unconditional(&e->arp)) ||
397 visited) {
398 unsigned int oldpos, size;
399
400 if ((strcmp(t->target.u.user.name,
401 ARPT_STANDARD_TARGET) == 0) &&
402 t->verdict < -NF_MAX_VERDICT - 1) {
403 duprintf("mark_source_chains: bad "
404 "negative verdict (%i)\n",
405 t->verdict);
406 return 0;
407 }
408
409 /* Return: backtrack through the last
410 * big jump.
411 */
412 do {
413 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
414 oldpos = pos;
415 pos = e->counters.pcnt;
416 e->counters.pcnt = 0;
417
418 /* We're at the start. */
419 if (pos == oldpos)
420 goto next;
421
422 e = (struct arpt_entry *)
423 (entry0 + pos);
424 } while (oldpos == pos + e->next_offset);
425
426 /* Move along one */
427 size = e->next_offset;
428 e = (struct arpt_entry *)
429 (entry0 + pos + size);
430 e->counters.pcnt = pos;
431 pos += size;
432 } else {
433 int newpos = t->verdict;
434
435 if (strcmp(t->target.u.user.name,
436 ARPT_STANDARD_TARGET) == 0 &&
437 newpos >= 0) {
438 if (newpos > newinfo->size -
439 sizeof(struct arpt_entry)) {
440 duprintf("mark_source_chains: "
441 "bad verdict (%i)\n",
442 newpos);
443 return 0;
444 }
445
446 /* This a jump; chase it. */
447 duprintf("Jump rule %u -> %u\n",
448 pos, newpos);
449 } else {
450 /* ... this is a fallthru */
451 newpos = pos + e->next_offset;
452 }
453 e = (struct arpt_entry *)
454 (entry0 + newpos);
455 e->counters.pcnt = pos;
456 pos = newpos;
457 }
458 }
459 next:
460 duprintf("Finished chain %u\n", hook);
461 }
462 return 1;
463 }
464
465 static inline int check_entry(const struct arpt_entry *e, const char *name)
466 {
467 const struct arpt_entry_target *t;
468
469 if (!arp_checkentry(&e->arp)) {
470 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
471 return -EINVAL;
472 }
473
474 if (e->target_offset + sizeof(struct arpt_entry_target) > e->next_offset)
475 return -EINVAL;
476
477 t = arpt_get_target_c(e);
478 if (e->target_offset + t->u.target_size > e->next_offset)
479 return -EINVAL;
480
481 return 0;
482 }
483
484 static inline int check_target(struct arpt_entry *e, const char *name)
485 {
486 struct arpt_entry_target *t = arpt_get_target(e);
487 int ret;
488 struct xt_tgchk_param par = {
489 .table = name,
490 .entryinfo = e,
491 .target = t->u.kernel.target,
492 .targinfo = t->data,
493 .hook_mask = e->comefrom,
494 .family = NFPROTO_ARP,
495 };
496
497 ret = xt_check_target(&par, t->u.target_size - sizeof(*t), 0, false);
498 if (ret < 0) {
499 duprintf("arp_tables: check failed for `%s'.\n",
500 t->u.kernel.target->name);
501 return ret;
502 }
503 return 0;
504 }
505
506 static inline int
507 find_check_entry(struct arpt_entry *e, const char *name, unsigned int size)
508 {
509 struct arpt_entry_target *t;
510 struct xt_target *target;
511 int ret;
512
513 ret = check_entry(e, name);
514 if (ret)
515 return ret;
516
517 t = arpt_get_target(e);
518 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
519 t->u.user.revision);
520 if (IS_ERR(target)) {
521 duprintf("find_check_entry: `%s' not found\n", t->u.user.name);
522 ret = PTR_ERR(target);
523 goto out;
524 }
525 t->u.kernel.target = target;
526
527 ret = check_target(e, name);
528 if (ret)
529 goto err;
530 return 0;
531 err:
532 module_put(t->u.kernel.target->me);
533 out:
534 return ret;
535 }
536
537 static bool check_underflow(const struct arpt_entry *e)
538 {
539 const struct arpt_entry_target *t;
540 unsigned int verdict;
541
542 if (!unconditional(&e->arp))
543 return false;
544 t = arpt_get_target_c(e);
545 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0)
546 return false;
547 verdict = ((struct arpt_standard_target *)t)->verdict;
548 verdict = -verdict - 1;
549 return verdict == NF_DROP || verdict == NF_ACCEPT;
550 }
551
552 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
553 struct xt_table_info *newinfo,
554 const unsigned char *base,
555 const unsigned char *limit,
556 const unsigned int *hook_entries,
557 const unsigned int *underflows,
558 unsigned int valid_hooks)
559 {
560 unsigned int h;
561
562 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 ||
563 (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
564 duprintf("Bad offset %p\n", e);
565 return -EINVAL;
566 }
567
568 if (e->next_offset
569 < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
570 duprintf("checking: element %p size %u\n",
571 e, e->next_offset);
572 return -EINVAL;
573 }
574
575 /* Check hooks & underflows */
576 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
577 if (!(valid_hooks & (1 << h)))
578 continue;
579 if ((unsigned char *)e - base == hook_entries[h])
580 newinfo->hook_entry[h] = hook_entries[h];
581 if ((unsigned char *)e - base == underflows[h]) {
582 if (!check_underflow(e)) {
583 pr_err("Underflows must be unconditional and "
584 "use the STANDARD target with "
585 "ACCEPT/DROP\n");
586 return -EINVAL;
587 }
588 newinfo->underflow[h] = underflows[h];
589 }
590 }
591
592 /* Clear counters and comefrom */
593 e->counters = ((struct xt_counters) { 0, 0 });
594 e->comefrom = 0;
595 return 0;
596 }
597
598 static inline void cleanup_entry(struct arpt_entry *e)
599 {
600 struct xt_tgdtor_param par;
601 struct arpt_entry_target *t;
602
603 t = arpt_get_target(e);
604 par.target = t->u.kernel.target;
605 par.targinfo = t->data;
606 par.family = NFPROTO_ARP;
607 if (par.target->destroy != NULL)
608 par.target->destroy(&par);
609 module_put(par.target->me);
610 }
611
612 /* Checks and translates the user-supplied table segment (held in
613 * newinfo).
614 */
615 static int translate_table(struct xt_table_info *newinfo, void *entry0,
616 const struct arpt_replace *repl)
617 {
618 struct arpt_entry *iter;
619 unsigned int i;
620 int ret = 0;
621
622 newinfo->size = repl->size;
623 newinfo->number = repl->num_entries;
624
625 /* Init all hooks to impossible value. */
626 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
627 newinfo->hook_entry[i] = 0xFFFFFFFF;
628 newinfo->underflow[i] = 0xFFFFFFFF;
629 }
630
631 duprintf("translate_table: size %u\n", newinfo->size);
632 i = 0;
633
634 /* Walk through entries, checking offsets. */
635 xt_entry_foreach(iter, entry0, newinfo->size) {
636 ret = check_entry_size_and_hooks(iter, newinfo, entry0,
637 entry0 + repl->size,
638 repl->hook_entry,
639 repl->underflow,
640 repl->valid_hooks);
641 if (ret != 0)
642 break;
643 ++i;
644 if (strcmp(arpt_get_target(iter)->u.user.name,
645 XT_ERROR_TARGET) == 0)
646 ++newinfo->stacksize;
647 }
648 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
649 if (ret != 0)
650 return ret;
651
652 if (i != repl->num_entries) {
653 duprintf("translate_table: %u not %u entries\n",
654 i, repl->num_entries);
655 return -EINVAL;
656 }
657
658 /* Check hooks all assigned */
659 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
660 /* Only hooks which are valid */
661 if (!(repl->valid_hooks & (1 << i)))
662 continue;
663 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
664 duprintf("Invalid hook entry %u %u\n",
665 i, repl->hook_entry[i]);
666 return -EINVAL;
667 }
668 if (newinfo->underflow[i] == 0xFFFFFFFF) {
669 duprintf("Invalid underflow %u %u\n",
670 i, repl->underflow[i]);
671 return -EINVAL;
672 }
673 }
674
675 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0)) {
676 duprintf("Looping hook\n");
677 return -ELOOP;
678 }
679
680 /* Finally, each sanity check must pass */
681 i = 0;
682 xt_entry_foreach(iter, entry0, newinfo->size) {
683 ret = find_check_entry(iter, repl->name, repl->size);
684 if (ret != 0)
685 break;
686 ++i;
687 }
688
689 if (ret != 0) {
690 xt_entry_foreach(iter, entry0, newinfo->size) {
691 if (i-- == 0)
692 break;
693 cleanup_entry(iter);
694 }
695 return ret;
696 }
697
698 /* And one copy for every other CPU */
699 for_each_possible_cpu(i) {
700 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
701 memcpy(newinfo->entries[i], entry0, newinfo->size);
702 }
703
704 return ret;
705 }
706
707 static void get_counters(const struct xt_table_info *t,
708 struct xt_counters counters[])
709 {
710 struct arpt_entry *iter;
711 unsigned int cpu;
712 unsigned int i;
713 unsigned int curcpu = get_cpu();
714
715 /* Instead of clearing (by a previous call to memset())
716 * the counters and using adds, we set the counters
717 * with data used by 'current' CPU
718 *
719 * Bottom half has to be disabled to prevent deadlock
720 * if new softirq were to run and call ipt_do_table
721 */
722 local_bh_disable();
723 i = 0;
724 xt_entry_foreach(iter, t->entries[curcpu], t->size) {
725 SET_COUNTER(counters[i], iter->counters.bcnt,
726 iter->counters.pcnt);
727 ++i;
728 }
729 local_bh_enable();
730 /* Processing counters from other cpus, we can let bottom half enabled,
731 * (preemption is disabled)
732 */
733
734 for_each_possible_cpu(cpu) {
735 if (cpu == curcpu)
736 continue;
737 i = 0;
738 xt_info_wrlock(cpu);
739 xt_entry_foreach(iter, t->entries[cpu], t->size) {
740 ADD_COUNTER(counters[i], iter->counters.bcnt,
741 iter->counters.pcnt);
742 ++i;
743 }
744 xt_info_wrunlock(cpu);
745 }
746 put_cpu();
747 }
748
749 static struct xt_counters *alloc_counters(const struct xt_table *table)
750 {
751 unsigned int countersize;
752 struct xt_counters *counters;
753 const struct xt_table_info *private = table->private;
754
755 /* We need atomic snapshot of counters: rest doesn't change
756 * (other than comefrom, which userspace doesn't care
757 * about).
758 */
759 countersize = sizeof(struct xt_counters) * private->number;
760 counters = vmalloc(countersize);
761
762 if (counters == NULL)
763 return ERR_PTR(-ENOMEM);
764
765 get_counters(private, counters);
766
767 return counters;
768 }
769
770 static int copy_entries_to_user(unsigned int total_size,
771 const struct xt_table *table,
772 void __user *userptr)
773 {
774 unsigned int off, num;
775 const struct arpt_entry *e;
776 struct xt_counters *counters;
777 struct xt_table_info *private = table->private;
778 int ret = 0;
779 void *loc_cpu_entry;
780
781 counters = alloc_counters(table);
782 if (IS_ERR(counters))
783 return PTR_ERR(counters);
784
785 loc_cpu_entry = private->entries[raw_smp_processor_id()];
786 /* ... then copy entire thing ... */
787 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
788 ret = -EFAULT;
789 goto free_counters;
790 }
791
792 /* FIXME: use iterator macros --RR */
793 /* ... then go back and fix counters and names */
794 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
795 const struct arpt_entry_target *t;
796
797 e = (struct arpt_entry *)(loc_cpu_entry + off);
798 if (copy_to_user(userptr + off
799 + offsetof(struct arpt_entry, counters),
800 &counters[num],
801 sizeof(counters[num])) != 0) {
802 ret = -EFAULT;
803 goto free_counters;
804 }
805
806 t = arpt_get_target_c(e);
807 if (copy_to_user(userptr + off + e->target_offset
808 + offsetof(struct arpt_entry_target,
809 u.user.name),
810 t->u.kernel.target->name,
811 strlen(t->u.kernel.target->name)+1) != 0) {
812 ret = -EFAULT;
813 goto free_counters;
814 }
815 }
816
817 free_counters:
818 vfree(counters);
819 return ret;
820 }
821
822 #ifdef CONFIG_COMPAT
823 static void compat_standard_from_user(void *dst, const void *src)
824 {
825 int v = *(compat_int_t *)src;
826
827 if (v > 0)
828 v += xt_compat_calc_jump(NFPROTO_ARP, v);
829 memcpy(dst, &v, sizeof(v));
830 }
831
832 static int compat_standard_to_user(void __user *dst, const void *src)
833 {
834 compat_int_t cv = *(int *)src;
835
836 if (cv > 0)
837 cv -= xt_compat_calc_jump(NFPROTO_ARP, cv);
838 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
839 }
840
841 static int compat_calc_entry(const struct arpt_entry *e,
842 const struct xt_table_info *info,
843 const void *base, struct xt_table_info *newinfo)
844 {
845 const struct arpt_entry_target *t;
846 unsigned int entry_offset;
847 int off, i, ret;
848
849 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
850 entry_offset = (void *)e - base;
851
852 t = arpt_get_target_c(e);
853 off += xt_compat_target_offset(t->u.kernel.target);
854 newinfo->size -= off;
855 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
856 if (ret)
857 return ret;
858
859 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
860 if (info->hook_entry[i] &&
861 (e < (struct arpt_entry *)(base + info->hook_entry[i])))
862 newinfo->hook_entry[i] -= off;
863 if (info->underflow[i] &&
864 (e < (struct arpt_entry *)(base + info->underflow[i])))
865 newinfo->underflow[i] -= off;
866 }
867 return 0;
868 }
869
870 static int compat_table_info(const struct xt_table_info *info,
871 struct xt_table_info *newinfo)
872 {
873 struct arpt_entry *iter;
874 void *loc_cpu_entry;
875 int ret;
876
877 if (!newinfo || !info)
878 return -EINVAL;
879
880 /* we dont care about newinfo->entries[] */
881 memcpy(newinfo, info, offsetof(struct xt_table_info, entries));
882 newinfo->initial_entries = 0;
883 loc_cpu_entry = info->entries[raw_smp_processor_id()];
884 xt_entry_foreach(iter, loc_cpu_entry, info->size) {
885 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo);
886 if (ret != 0)
887 return ret;
888 }
889 return 0;
890 }
891 #endif
892
893 static int get_info(struct net *net, void __user *user,
894 const int *len, int compat)
895 {
896 char name[ARPT_TABLE_MAXNAMELEN];
897 struct xt_table *t;
898 int ret;
899
900 if (*len != sizeof(struct arpt_getinfo)) {
901 duprintf("length %u != %Zu\n", *len,
902 sizeof(struct arpt_getinfo));
903 return -EINVAL;
904 }
905
906 if (copy_from_user(name, user, sizeof(name)) != 0)
907 return -EFAULT;
908
909 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
910 #ifdef CONFIG_COMPAT
911 if (compat)
912 xt_compat_lock(NFPROTO_ARP);
913 #endif
914 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
915 "arptable_%s", name);
916 if (t && !IS_ERR(t)) {
917 struct arpt_getinfo info;
918 const struct xt_table_info *private = t->private;
919 #ifdef CONFIG_COMPAT
920 struct xt_table_info tmp;
921
922 if (compat) {
923 ret = compat_table_info(private, &tmp);
924 xt_compat_flush_offsets(NFPROTO_ARP);
925 private = &tmp;
926 }
927 #endif
928 info.valid_hooks = t->valid_hooks;
929 memcpy(info.hook_entry, private->hook_entry,
930 sizeof(info.hook_entry));
931 memcpy(info.underflow, private->underflow,
932 sizeof(info.underflow));
933 info.num_entries = private->number;
934 info.size = private->size;
935 strcpy(info.name, name);
936
937 if (copy_to_user(user, &info, *len) != 0)
938 ret = -EFAULT;
939 else
940 ret = 0;
941 xt_table_unlock(t);
942 module_put(t->me);
943 } else
944 ret = t ? PTR_ERR(t) : -ENOENT;
945 #ifdef CONFIG_COMPAT
946 if (compat)
947 xt_compat_unlock(NFPROTO_ARP);
948 #endif
949 return ret;
950 }
951
952 static int get_entries(struct net *net, struct arpt_get_entries __user *uptr,
953 const int *len)
954 {
955 int ret;
956 struct arpt_get_entries get;
957 struct xt_table *t;
958
959 if (*len < sizeof(get)) {
960 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
961 return -EINVAL;
962 }
963 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
964 return -EFAULT;
965 if (*len != sizeof(struct arpt_get_entries) + get.size) {
966 duprintf("get_entries: %u != %Zu\n", *len,
967 sizeof(struct arpt_get_entries) + get.size);
968 return -EINVAL;
969 }
970
971 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
972 if (t && !IS_ERR(t)) {
973 const struct xt_table_info *private = t->private;
974
975 duprintf("t->private->number = %u\n",
976 private->number);
977 if (get.size == private->size)
978 ret = copy_entries_to_user(private->size,
979 t, uptr->entrytable);
980 else {
981 duprintf("get_entries: I've got %u not %u!\n",
982 private->size, get.size);
983 ret = -EAGAIN;
984 }
985 module_put(t->me);
986 xt_table_unlock(t);
987 } else
988 ret = t ? PTR_ERR(t) : -ENOENT;
989
990 return ret;
991 }
992
993 static int __do_replace(struct net *net, const char *name,
994 unsigned int valid_hooks,
995 struct xt_table_info *newinfo,
996 unsigned int num_counters,
997 void __user *counters_ptr)
998 {
999 int ret;
1000 struct xt_table *t;
1001 struct xt_table_info *oldinfo;
1002 struct xt_counters *counters;
1003 void *loc_cpu_old_entry;
1004 struct arpt_entry *iter;
1005
1006 ret = 0;
1007 counters = vmalloc(num_counters * sizeof(struct xt_counters));
1008 if (!counters) {
1009 ret = -ENOMEM;
1010 goto out;
1011 }
1012
1013 t = try_then_request_module(xt_find_table_lock(net, NFPROTO_ARP, name),
1014 "arptable_%s", name);
1015 if (!t || IS_ERR(t)) {
1016 ret = t ? PTR_ERR(t) : -ENOENT;
1017 goto free_newinfo_counters_untrans;
1018 }
1019
1020 /* You lied! */
1021 if (valid_hooks != t->valid_hooks) {
1022 duprintf("Valid hook crap: %08X vs %08X\n",
1023 valid_hooks, t->valid_hooks);
1024 ret = -EINVAL;
1025 goto put_module;
1026 }
1027
1028 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret);
1029 if (!oldinfo)
1030 goto put_module;
1031
1032 /* Update module usage count based on number of rules */
1033 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
1034 oldinfo->number, oldinfo->initial_entries, newinfo->number);
1035 if ((oldinfo->number > oldinfo->initial_entries) ||
1036 (newinfo->number <= oldinfo->initial_entries))
1037 module_put(t->me);
1038 if ((oldinfo->number > oldinfo->initial_entries) &&
1039 (newinfo->number <= oldinfo->initial_entries))
1040 module_put(t->me);
1041
1042 /* Get the old counters, and synchronize with replace */
1043 get_counters(oldinfo, counters);
1044
1045 /* Decrease module usage counts and free resource */
1046 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
1047 xt_entry_foreach(iter, loc_cpu_old_entry, oldinfo->size)
1048 cleanup_entry(iter);
1049
1050 xt_free_table_info(oldinfo);
1051 if (copy_to_user(counters_ptr, counters,
1052 sizeof(struct xt_counters) * num_counters) != 0)
1053 ret = -EFAULT;
1054 vfree(counters);
1055 xt_table_unlock(t);
1056 return ret;
1057
1058 put_module:
1059 module_put(t->me);
1060 xt_table_unlock(t);
1061 free_newinfo_counters_untrans:
1062 vfree(counters);
1063 out:
1064 return ret;
1065 }
1066
1067 static int do_replace(struct net *net, const void __user *user,
1068 unsigned int len)
1069 {
1070 int ret;
1071 struct arpt_replace tmp;
1072 struct xt_table_info *newinfo;
1073 void *loc_cpu_entry;
1074 struct arpt_entry *iter;
1075
1076 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1077 return -EFAULT;
1078
1079 /* overflow check */
1080 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1081 return -ENOMEM;
1082
1083 newinfo = xt_alloc_table_info(tmp.size);
1084 if (!newinfo)
1085 return -ENOMEM;
1086
1087 /* choose the copy that is on our node/cpu */
1088 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1089 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
1090 tmp.size) != 0) {
1091 ret = -EFAULT;
1092 goto free_newinfo;
1093 }
1094
1095 ret = translate_table(newinfo, loc_cpu_entry, &tmp);
1096 if (ret != 0)
1097 goto free_newinfo;
1098
1099 duprintf("arp_tables: Translated table\n");
1100
1101 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1102 tmp.num_counters, tmp.counters);
1103 if (ret)
1104 goto free_newinfo_untrans;
1105 return 0;
1106
1107 free_newinfo_untrans:
1108 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1109 cleanup_entry(iter);
1110 free_newinfo:
1111 xt_free_table_info(newinfo);
1112 return ret;
1113 }
1114
1115 static int do_add_counters(struct net *net, const void __user *user,
1116 unsigned int len, int compat)
1117 {
1118 unsigned int i, curcpu;
1119 struct xt_counters_info tmp;
1120 struct xt_counters *paddc;
1121 unsigned int num_counters;
1122 const char *name;
1123 int size;
1124 void *ptmp;
1125 struct xt_table *t;
1126 const struct xt_table_info *private;
1127 int ret = 0;
1128 void *loc_cpu_entry;
1129 struct arpt_entry *iter;
1130 #ifdef CONFIG_COMPAT
1131 struct compat_xt_counters_info compat_tmp;
1132
1133 if (compat) {
1134 ptmp = &compat_tmp;
1135 size = sizeof(struct compat_xt_counters_info);
1136 } else
1137 #endif
1138 {
1139 ptmp = &tmp;
1140 size = sizeof(struct xt_counters_info);
1141 }
1142
1143 if (copy_from_user(ptmp, user, size) != 0)
1144 return -EFAULT;
1145
1146 #ifdef CONFIG_COMPAT
1147 if (compat) {
1148 num_counters = compat_tmp.num_counters;
1149 name = compat_tmp.name;
1150 } else
1151 #endif
1152 {
1153 num_counters = tmp.num_counters;
1154 name = tmp.name;
1155 }
1156
1157 if (len != size + num_counters * sizeof(struct xt_counters))
1158 return -EINVAL;
1159
1160 paddc = vmalloc(len - size);
1161 if (!paddc)
1162 return -ENOMEM;
1163
1164 if (copy_from_user(paddc, user + size, len - size) != 0) {
1165 ret = -EFAULT;
1166 goto free;
1167 }
1168
1169 t = xt_find_table_lock(net, NFPROTO_ARP, name);
1170 if (!t || IS_ERR(t)) {
1171 ret = t ? PTR_ERR(t) : -ENOENT;
1172 goto free;
1173 }
1174
1175 local_bh_disable();
1176 private = t->private;
1177 if (private->number != num_counters) {
1178 ret = -EINVAL;
1179 goto unlock_up_free;
1180 }
1181
1182 i = 0;
1183 /* Choose the copy that is on our node */
1184 curcpu = smp_processor_id();
1185 loc_cpu_entry = private->entries[curcpu];
1186 xt_info_wrlock(curcpu);
1187 xt_entry_foreach(iter, loc_cpu_entry, private->size) {
1188 ADD_COUNTER(iter->counters, paddc[i].bcnt, paddc[i].pcnt);
1189 ++i;
1190 }
1191 xt_info_wrunlock(curcpu);
1192 unlock_up_free:
1193 local_bh_enable();
1194 xt_table_unlock(t);
1195 module_put(t->me);
1196 free:
1197 vfree(paddc);
1198
1199 return ret;
1200 }
1201
1202 #ifdef CONFIG_COMPAT
1203 static inline void compat_release_entry(struct compat_arpt_entry *e)
1204 {
1205 struct arpt_entry_target *t;
1206
1207 t = compat_arpt_get_target(e);
1208 module_put(t->u.kernel.target->me);
1209 }
1210
1211 static inline int
1212 check_compat_entry_size_and_hooks(struct compat_arpt_entry *e,
1213 struct xt_table_info *newinfo,
1214 unsigned int *size,
1215 const unsigned char *base,
1216 const unsigned char *limit,
1217 const unsigned int *hook_entries,
1218 const unsigned int *underflows,
1219 const char *name)
1220 {
1221 struct arpt_entry_target *t;
1222 struct xt_target *target;
1223 unsigned int entry_offset;
1224 int ret, off, h;
1225
1226 duprintf("check_compat_entry_size_and_hooks %p\n", e);
1227 if ((unsigned long)e % __alignof__(struct compat_arpt_entry) != 0 ||
1228 (unsigned char *)e + sizeof(struct compat_arpt_entry) >= limit) {
1229 duprintf("Bad offset %p, limit = %p\n", e, limit);
1230 return -EINVAL;
1231 }
1232
1233 if (e->next_offset < sizeof(struct compat_arpt_entry) +
1234 sizeof(struct compat_xt_entry_target)) {
1235 duprintf("checking: element %p size %u\n",
1236 e, e->next_offset);
1237 return -EINVAL;
1238 }
1239
1240 /* For purposes of check_entry casting the compat entry is fine */
1241 ret = check_entry((struct arpt_entry *)e, name);
1242 if (ret)
1243 return ret;
1244
1245 off = sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1246 entry_offset = (void *)e - (void *)base;
1247
1248 t = compat_arpt_get_target(e);
1249 target = xt_request_find_target(NFPROTO_ARP, t->u.user.name,
1250 t->u.user.revision);
1251 if (IS_ERR(target)) {
1252 duprintf("check_compat_entry_size_and_hooks: `%s' not found\n",
1253 t->u.user.name);
1254 ret = PTR_ERR(target);
1255 goto out;
1256 }
1257 t->u.kernel.target = target;
1258
1259 off += xt_compat_target_offset(target);
1260 *size += off;
1261 ret = xt_compat_add_offset(NFPROTO_ARP, entry_offset, off);
1262 if (ret)
1263 goto release_target;
1264
1265 /* Check hooks & underflows */
1266 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1267 if ((unsigned char *)e - base == hook_entries[h])
1268 newinfo->hook_entry[h] = hook_entries[h];
1269 if ((unsigned char *)e - base == underflows[h])
1270 newinfo->underflow[h] = underflows[h];
1271 }
1272
1273 /* Clear counters and comefrom */
1274 memset(&e->counters, 0, sizeof(e->counters));
1275 e->comefrom = 0;
1276 return 0;
1277
1278 release_target:
1279 module_put(t->u.kernel.target->me);
1280 out:
1281 return ret;
1282 }
1283
1284 static int
1285 compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
1286 unsigned int *size, const char *name,
1287 struct xt_table_info *newinfo, unsigned char *base)
1288 {
1289 struct arpt_entry_target *t;
1290 struct xt_target *target;
1291 struct arpt_entry *de;
1292 unsigned int origsize;
1293 int ret, h;
1294
1295 ret = 0;
1296 origsize = *size;
1297 de = (struct arpt_entry *)*dstptr;
1298 memcpy(de, e, sizeof(struct arpt_entry));
1299 memcpy(&de->counters, &e->counters, sizeof(e->counters));
1300
1301 *dstptr += sizeof(struct arpt_entry);
1302 *size += sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1303
1304 de->target_offset = e->target_offset - (origsize - *size);
1305 t = compat_arpt_get_target(e);
1306 target = t->u.kernel.target;
1307 xt_compat_target_from_user(t, dstptr, size);
1308
1309 de->next_offset = e->next_offset - (origsize - *size);
1310 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
1311 if ((unsigned char *)de - base < newinfo->hook_entry[h])
1312 newinfo->hook_entry[h] -= origsize - *size;
1313 if ((unsigned char *)de - base < newinfo->underflow[h])
1314 newinfo->underflow[h] -= origsize - *size;
1315 }
1316 return ret;
1317 }
1318
1319 static int translate_compat_table(const char *name,
1320 unsigned int valid_hooks,
1321 struct xt_table_info **pinfo,
1322 void **pentry0,
1323 unsigned int total_size,
1324 unsigned int number,
1325 unsigned int *hook_entries,
1326 unsigned int *underflows)
1327 {
1328 unsigned int i, j;
1329 struct xt_table_info *newinfo, *info;
1330 void *pos, *entry0, *entry1;
1331 struct compat_arpt_entry *iter0;
1332 struct arpt_entry *iter1;
1333 unsigned int size;
1334 int ret = 0;
1335
1336 info = *pinfo;
1337 entry0 = *pentry0;
1338 size = total_size;
1339 info->number = number;
1340
1341 /* Init all hooks to impossible value. */
1342 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1343 info->hook_entry[i] = 0xFFFFFFFF;
1344 info->underflow[i] = 0xFFFFFFFF;
1345 }
1346
1347 duprintf("translate_compat_table: size %u\n", info->size);
1348 j = 0;
1349 xt_compat_lock(NFPROTO_ARP);
1350 /* Walk through entries, checking offsets. */
1351 xt_entry_foreach(iter0, entry0, total_size) {
1352 ret = check_compat_entry_size_and_hooks(iter0, info, &size,
1353 entry0,
1354 entry0 + total_size,
1355 hook_entries,
1356 underflows,
1357 name);
1358 if (ret != 0)
1359 goto out_unlock;
1360 ++j;
1361 }
1362
1363 ret = -EINVAL;
1364 if (j != number) {
1365 duprintf("translate_compat_table: %u not %u entries\n",
1366 j, number);
1367 goto out_unlock;
1368 }
1369
1370 /* Check hooks all assigned */
1371 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1372 /* Only hooks which are valid */
1373 if (!(valid_hooks & (1 << i)))
1374 continue;
1375 if (info->hook_entry[i] == 0xFFFFFFFF) {
1376 duprintf("Invalid hook entry %u %u\n",
1377 i, hook_entries[i]);
1378 goto out_unlock;
1379 }
1380 if (info->underflow[i] == 0xFFFFFFFF) {
1381 duprintf("Invalid underflow %u %u\n",
1382 i, underflows[i]);
1383 goto out_unlock;
1384 }
1385 }
1386
1387 ret = -ENOMEM;
1388 newinfo = xt_alloc_table_info(size);
1389 if (!newinfo)
1390 goto out_unlock;
1391
1392 newinfo->number = number;
1393 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
1394 newinfo->hook_entry[i] = info->hook_entry[i];
1395 newinfo->underflow[i] = info->underflow[i];
1396 }
1397 entry1 = newinfo->entries[raw_smp_processor_id()];
1398 pos = entry1;
1399 size = total_size;
1400 xt_entry_foreach(iter0, entry0, total_size) {
1401 ret = compat_copy_entry_from_user(iter0, &pos, &size,
1402 name, newinfo, entry1);
1403 if (ret != 0)
1404 break;
1405 }
1406 xt_compat_flush_offsets(NFPROTO_ARP);
1407 xt_compat_unlock(NFPROTO_ARP);
1408 if (ret)
1409 goto free_newinfo;
1410
1411 ret = -ELOOP;
1412 if (!mark_source_chains(newinfo, valid_hooks, entry1))
1413 goto free_newinfo;
1414
1415 i = 0;
1416 xt_entry_foreach(iter1, entry1, newinfo->size) {
1417 ret = check_target(iter1, name);
1418 if (ret != 0)
1419 break;
1420 ++i;
1421 }
1422 if (ret) {
1423 /*
1424 * The first i matches need cleanup_entry (calls ->destroy)
1425 * because they had called ->check already. The other j-i
1426 * entries need only release.
1427 */
1428 int skip = i;
1429 j -= i;
1430 xt_entry_foreach(iter0, entry0, newinfo->size) {
1431 if (skip-- > 0)
1432 continue;
1433 if (j-- == 0)
1434 break;
1435 compat_release_entry(iter0);
1436 }
1437 xt_entry_foreach(iter1, entry1, newinfo->size) {
1438 if (i-- == 0)
1439 break;
1440 cleanup_entry(iter1);
1441 }
1442 xt_free_table_info(newinfo);
1443 return ret;
1444 }
1445
1446 /* And one copy for every other CPU */
1447 for_each_possible_cpu(i)
1448 if (newinfo->entries[i] && newinfo->entries[i] != entry1)
1449 memcpy(newinfo->entries[i], entry1, newinfo->size);
1450
1451 *pinfo = newinfo;
1452 *pentry0 = entry1;
1453 xt_free_table_info(info);
1454 return 0;
1455
1456 free_newinfo:
1457 xt_free_table_info(newinfo);
1458 out:
1459 xt_entry_foreach(iter0, entry0, total_size) {
1460 if (j-- == 0)
1461 break;
1462 compat_release_entry(iter0);
1463 }
1464 return ret;
1465 out_unlock:
1466 xt_compat_flush_offsets(NFPROTO_ARP);
1467 xt_compat_unlock(NFPROTO_ARP);
1468 goto out;
1469 }
1470
1471 struct compat_arpt_replace {
1472 char name[ARPT_TABLE_MAXNAMELEN];
1473 u32 valid_hooks;
1474 u32 num_entries;
1475 u32 size;
1476 u32 hook_entry[NF_ARP_NUMHOOKS];
1477 u32 underflow[NF_ARP_NUMHOOKS];
1478 u32 num_counters;
1479 compat_uptr_t counters;
1480 struct compat_arpt_entry entries[0];
1481 };
1482
1483 static int compat_do_replace(struct net *net, void __user *user,
1484 unsigned int len)
1485 {
1486 int ret;
1487 struct compat_arpt_replace tmp;
1488 struct xt_table_info *newinfo;
1489 void *loc_cpu_entry;
1490 struct arpt_entry *iter;
1491
1492 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
1493 return -EFAULT;
1494
1495 /* overflow check */
1496 if (tmp.size >= INT_MAX / num_possible_cpus())
1497 return -ENOMEM;
1498 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
1499 return -ENOMEM;
1500
1501 newinfo = xt_alloc_table_info(tmp.size);
1502 if (!newinfo)
1503 return -ENOMEM;
1504
1505 /* choose the copy that is on our node/cpu */
1506 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1507 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), tmp.size) != 0) {
1508 ret = -EFAULT;
1509 goto free_newinfo;
1510 }
1511
1512 ret = translate_compat_table(tmp.name, tmp.valid_hooks,
1513 &newinfo, &loc_cpu_entry, tmp.size,
1514 tmp.num_entries, tmp.hook_entry,
1515 tmp.underflow);
1516 if (ret != 0)
1517 goto free_newinfo;
1518
1519 duprintf("compat_do_replace: Translated table\n");
1520
1521 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo,
1522 tmp.num_counters, compat_ptr(tmp.counters));
1523 if (ret)
1524 goto free_newinfo_untrans;
1525 return 0;
1526
1527 free_newinfo_untrans:
1528 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size)
1529 cleanup_entry(iter);
1530 free_newinfo:
1531 xt_free_table_info(newinfo);
1532 return ret;
1533 }
1534
1535 static int compat_do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user,
1536 unsigned int len)
1537 {
1538 int ret;
1539
1540 if (!capable(CAP_NET_ADMIN))
1541 return -EPERM;
1542
1543 switch (cmd) {
1544 case ARPT_SO_SET_REPLACE:
1545 ret = compat_do_replace(sock_net(sk), user, len);
1546 break;
1547
1548 case ARPT_SO_SET_ADD_COUNTERS:
1549 ret = do_add_counters(sock_net(sk), user, len, 1);
1550 break;
1551
1552 default:
1553 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1554 ret = -EINVAL;
1555 }
1556
1557 return ret;
1558 }
1559
1560 static int compat_copy_entry_to_user(struct arpt_entry *e, void __user **dstptr,
1561 compat_uint_t *size,
1562 struct xt_counters *counters,
1563 unsigned int i)
1564 {
1565 struct arpt_entry_target *t;
1566 struct compat_arpt_entry __user *ce;
1567 u_int16_t target_offset, next_offset;
1568 compat_uint_t origsize;
1569 int ret;
1570
1571 origsize = *size;
1572 ce = (struct compat_arpt_entry __user *)*dstptr;
1573 if (copy_to_user(ce, e, sizeof(struct arpt_entry)) != 0 ||
1574 copy_to_user(&ce->counters, &counters[i],
1575 sizeof(counters[i])) != 0)
1576 return -EFAULT;
1577
1578 *dstptr += sizeof(struct compat_arpt_entry);
1579 *size -= sizeof(struct arpt_entry) - sizeof(struct compat_arpt_entry);
1580
1581 target_offset = e->target_offset - (origsize - *size);
1582
1583 t = arpt_get_target(e);
1584 ret = xt_compat_target_to_user(t, dstptr, size);
1585 if (ret)
1586 return ret;
1587 next_offset = e->next_offset - (origsize - *size);
1588 if (put_user(target_offset, &ce->target_offset) != 0 ||
1589 put_user(next_offset, &ce->next_offset) != 0)
1590 return -EFAULT;
1591 return 0;
1592 }
1593
1594 static int compat_copy_entries_to_user(unsigned int total_size,
1595 struct xt_table *table,
1596 void __user *userptr)
1597 {
1598 struct xt_counters *counters;
1599 const struct xt_table_info *private = table->private;
1600 void __user *pos;
1601 unsigned int size;
1602 int ret = 0;
1603 void *loc_cpu_entry;
1604 unsigned int i = 0;
1605 struct arpt_entry *iter;
1606
1607 counters = alloc_counters(table);
1608 if (IS_ERR(counters))
1609 return PTR_ERR(counters);
1610
1611 /* choose the copy on our node/cpu */
1612 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1613 pos = userptr;
1614 size = total_size;
1615 xt_entry_foreach(iter, loc_cpu_entry, total_size) {
1616 ret = compat_copy_entry_to_user(iter, &pos,
1617 &size, counters, i++);
1618 if (ret != 0)
1619 break;
1620 }
1621 vfree(counters);
1622 return ret;
1623 }
1624
1625 struct compat_arpt_get_entries {
1626 char name[ARPT_TABLE_MAXNAMELEN];
1627 compat_uint_t size;
1628 struct compat_arpt_entry entrytable[0];
1629 };
1630
1631 static int compat_get_entries(struct net *net,
1632 struct compat_arpt_get_entries __user *uptr,
1633 int *len)
1634 {
1635 int ret;
1636 struct compat_arpt_get_entries get;
1637 struct xt_table *t;
1638
1639 if (*len < sizeof(get)) {
1640 duprintf("compat_get_entries: %u < %zu\n", *len, sizeof(get));
1641 return -EINVAL;
1642 }
1643 if (copy_from_user(&get, uptr, sizeof(get)) != 0)
1644 return -EFAULT;
1645 if (*len != sizeof(struct compat_arpt_get_entries) + get.size) {
1646 duprintf("compat_get_entries: %u != %zu\n",
1647 *len, sizeof(get) + get.size);
1648 return -EINVAL;
1649 }
1650
1651 xt_compat_lock(NFPROTO_ARP);
1652 t = xt_find_table_lock(net, NFPROTO_ARP, get.name);
1653 if (t && !IS_ERR(t)) {
1654 const struct xt_table_info *private = t->private;
1655 struct xt_table_info info;
1656
1657 duprintf("t->private->number = %u\n", private->number);
1658 ret = compat_table_info(private, &info);
1659 if (!ret && get.size == info.size) {
1660 ret = compat_copy_entries_to_user(private->size,
1661 t, uptr->entrytable);
1662 } else if (!ret) {
1663 duprintf("compat_get_entries: I've got %u not %u!\n",
1664 private->size, get.size);
1665 ret = -EAGAIN;
1666 }
1667 xt_compat_flush_offsets(NFPROTO_ARP);
1668 module_put(t->me);
1669 xt_table_unlock(t);
1670 } else
1671 ret = t ? PTR_ERR(t) : -ENOENT;
1672
1673 xt_compat_unlock(NFPROTO_ARP);
1674 return ret;
1675 }
1676
1677 static int do_arpt_get_ctl(struct sock *, int, void __user *, int *);
1678
1679 static int compat_do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user,
1680 int *len)
1681 {
1682 int ret;
1683
1684 if (!capable(CAP_NET_ADMIN))
1685 return -EPERM;
1686
1687 switch (cmd) {
1688 case ARPT_SO_GET_INFO:
1689 ret = get_info(sock_net(sk), user, len, 1);
1690 break;
1691 case ARPT_SO_GET_ENTRIES:
1692 ret = compat_get_entries(sock_net(sk), user, len);
1693 break;
1694 default:
1695 ret = do_arpt_get_ctl(sk, cmd, user, len);
1696 }
1697 return ret;
1698 }
1699 #endif
1700
1701 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1702 {
1703 int ret;
1704
1705 if (!capable(CAP_NET_ADMIN))
1706 return -EPERM;
1707
1708 switch (cmd) {
1709 case ARPT_SO_SET_REPLACE:
1710 ret = do_replace(sock_net(sk), user, len);
1711 break;
1712
1713 case ARPT_SO_SET_ADD_COUNTERS:
1714 ret = do_add_counters(sock_net(sk), user, len, 0);
1715 break;
1716
1717 default:
1718 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1719 ret = -EINVAL;
1720 }
1721
1722 return ret;
1723 }
1724
1725 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1726 {
1727 int ret;
1728
1729 if (!capable(CAP_NET_ADMIN))
1730 return -EPERM;
1731
1732 switch (cmd) {
1733 case ARPT_SO_GET_INFO:
1734 ret = get_info(sock_net(sk), user, len, 0);
1735 break;
1736
1737 case ARPT_SO_GET_ENTRIES:
1738 ret = get_entries(sock_net(sk), user, len);
1739 break;
1740
1741 case ARPT_SO_GET_REVISION_TARGET: {
1742 struct xt_get_revision rev;
1743
1744 if (*len != sizeof(rev)) {
1745 ret = -EINVAL;
1746 break;
1747 }
1748 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1749 ret = -EFAULT;
1750 break;
1751 }
1752
1753 try_then_request_module(xt_find_revision(NFPROTO_ARP, rev.name,
1754 rev.revision, 1, &ret),
1755 "arpt_%s", rev.name);
1756 break;
1757 }
1758
1759 default:
1760 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1761 ret = -EINVAL;
1762 }
1763
1764 return ret;
1765 }
1766
1767 struct xt_table *arpt_register_table(struct net *net,
1768 const struct xt_table *table,
1769 const struct arpt_replace *repl)
1770 {
1771 int ret;
1772 struct xt_table_info *newinfo;
1773 struct xt_table_info bootstrap = {0};
1774 void *loc_cpu_entry;
1775 struct xt_table *new_table;
1776
1777 newinfo = xt_alloc_table_info(repl->size);
1778 if (!newinfo) {
1779 ret = -ENOMEM;
1780 goto out;
1781 }
1782
1783 /* choose the copy on our node/cpu */
1784 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1785 memcpy(loc_cpu_entry, repl->entries, repl->size);
1786
1787 ret = translate_table(newinfo, loc_cpu_entry, repl);
1788 duprintf("arpt_register_table: translate table gives %d\n", ret);
1789 if (ret != 0)
1790 goto out_free;
1791
1792 new_table = xt_register_table(net, table, &bootstrap, newinfo);
1793 if (IS_ERR(new_table)) {
1794 ret = PTR_ERR(new_table);
1795 goto out_free;
1796 }
1797 return new_table;
1798
1799 out_free:
1800 xt_free_table_info(newinfo);
1801 out:
1802 return ERR_PTR(ret);
1803 }
1804
1805 void arpt_unregister_table(struct xt_table *table)
1806 {
1807 struct xt_table_info *private;
1808 void *loc_cpu_entry;
1809 struct module *table_owner = table->me;
1810 struct arpt_entry *iter;
1811
1812 private = xt_unregister_table(table);
1813
1814 /* Decrease module usage counts and free resources */
1815 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1816 xt_entry_foreach(iter, loc_cpu_entry, private->size)
1817 cleanup_entry(iter);
1818 if (private->number > private->initial_entries)
1819 module_put(table_owner);
1820 xt_free_table_info(private);
1821 }
1822
1823 /* The built-in targets: standard (NULL) and error. */
1824 static struct xt_target arpt_builtin_tg[] __read_mostly = {
1825 {
1826 .name = ARPT_STANDARD_TARGET,
1827 .targetsize = sizeof(int),
1828 .family = NFPROTO_ARP,
1829 #ifdef CONFIG_COMPAT
1830 .compatsize = sizeof(compat_int_t),
1831 .compat_from_user = compat_standard_from_user,
1832 .compat_to_user = compat_standard_to_user,
1833 #endif
1834 },
1835 {
1836 .name = ARPT_ERROR_TARGET,
1837 .target = arpt_error,
1838 .targetsize = ARPT_FUNCTION_MAXNAMELEN,
1839 .family = NFPROTO_ARP,
1840 },
1841 };
1842
1843 static struct nf_sockopt_ops arpt_sockopts = {
1844 .pf = PF_INET,
1845 .set_optmin = ARPT_BASE_CTL,
1846 .set_optmax = ARPT_SO_SET_MAX+1,
1847 .set = do_arpt_set_ctl,
1848 #ifdef CONFIG_COMPAT
1849 .compat_set = compat_do_arpt_set_ctl,
1850 #endif
1851 .get_optmin = ARPT_BASE_CTL,
1852 .get_optmax = ARPT_SO_GET_MAX+1,
1853 .get = do_arpt_get_ctl,
1854 #ifdef CONFIG_COMPAT
1855 .compat_get = compat_do_arpt_get_ctl,
1856 #endif
1857 .owner = THIS_MODULE,
1858 };
1859
1860 static int __net_init arp_tables_net_init(struct net *net)
1861 {
1862 return xt_proto_init(net, NFPROTO_ARP);
1863 }
1864
1865 static void __net_exit arp_tables_net_exit(struct net *net)
1866 {
1867 xt_proto_fini(net, NFPROTO_ARP);
1868 }
1869
1870 static struct pernet_operations arp_tables_net_ops = {
1871 .init = arp_tables_net_init,
1872 .exit = arp_tables_net_exit,
1873 };
1874
1875 static int __init arp_tables_init(void)
1876 {
1877 int ret;
1878
1879 ret = register_pernet_subsys(&arp_tables_net_ops);
1880 if (ret < 0)
1881 goto err1;
1882
1883 /* Noone else will be downing sem now, so we won't sleep */
1884 ret = xt_register_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1885 if (ret < 0)
1886 goto err2;
1887
1888 /* Register setsockopt */
1889 ret = nf_register_sockopt(&arpt_sockopts);
1890 if (ret < 0)
1891 goto err4;
1892
1893 printk(KERN_INFO "arp_tables: (C) 2002 David S. Miller\n");
1894 return 0;
1895
1896 err4:
1897 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1898 err2:
1899 unregister_pernet_subsys(&arp_tables_net_ops);
1900 err1:
1901 return ret;
1902 }
1903
1904 static void __exit arp_tables_fini(void)
1905 {
1906 nf_unregister_sockopt(&arpt_sockopts);
1907 xt_unregister_targets(arpt_builtin_tg, ARRAY_SIZE(arpt_builtin_tg));
1908 unregister_pernet_subsys(&arp_tables_net_ops);
1909 }
1910
1911 EXPORT_SYMBOL(arpt_register_table);
1912 EXPORT_SYMBOL(arpt_unregister_table);
1913 EXPORT_SYMBOL(arpt_do_table);
1914
1915 module_init(arp_tables_init);
1916 module_exit(arp_tables_fini);
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