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[NETFILTER]: {arp,ip,ip6}_tables: proper error recovery in init path
[linux-2.6.git] / net / ipv4 / netfilter / arp_tables.c
blobdf4854cf598bbea46da6b19b6c2bb0ffdc0436fe
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
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
23 #include <asm/uaccess.h>
24 #include <linux/mutex.h>
25
26 #include <linux/netfilter/x_tables.h>
27 #include <linux/netfilter_arp/arp_tables.h>
28
29 MODULE_LICENSE("GPL");
30 MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
31 MODULE_DESCRIPTION("arptables core");
32
33 /*#define DEBUG_ARP_TABLES*/
34 /*#define DEBUG_ARP_TABLES_USER*/
35
36 #ifdef DEBUG_ARP_TABLES
37 #define dprintf(format, args...) printk(format , ## args)
38 #else
39 #define dprintf(format, args...)
40 #endif
41
42 #ifdef DEBUG_ARP_TABLES_USER
43 #define duprintf(format, args...) printk(format , ## args)
44 #else
45 #define duprintf(format, args...)
46 #endif
47
48 #ifdef CONFIG_NETFILTER_DEBUG
49 #define ARP_NF_ASSERT(x) \
50 do { \
51 if (!(x)) \
52 printk("ARP_NF_ASSERT: %s:%s:%u\n", \
53 __FUNCTION__, __FILE__, __LINE__); \
54 } while(0)
55 #else
56 #define ARP_NF_ASSERT(x)
57 #endif
58
59 #include <linux/netfilter_ipv4/listhelp.h>
60
61 static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
62 char *hdr_addr, int len)
63 {
64 int i, ret;
65
66 if (len > ARPT_DEV_ADDR_LEN_MAX)
67 len = ARPT_DEV_ADDR_LEN_MAX;
68
69 ret = 0;
70 for (i = 0; i < len; i++)
71 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
72
73 return (ret != 0);
74 }
75
76 /* Returns whether packet matches rule or not. */
77 static inline int arp_packet_match(const struct arphdr *arphdr,
78 struct net_device *dev,
79 const char *indev,
80 const char *outdev,
81 const struct arpt_arp *arpinfo)
82 {
83 char *arpptr = (char *)(arphdr + 1);
84 char *src_devaddr, *tgt_devaddr;
85 u32 src_ipaddr, tgt_ipaddr;
86 int i, ret;
87
88 #define FWINV(bool,invflg) ((bool) ^ !!(arpinfo->invflags & invflg))
89
90 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
91 ARPT_INV_ARPOP)) {
92 dprintf("ARP operation field mismatch.\n");
93 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
94 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
95 return 0;
96 }
97
98 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
99 ARPT_INV_ARPHRD)) {
100 dprintf("ARP hardware address format mismatch.\n");
101 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
102 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
103 return 0;
104 }
105
106 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
107 ARPT_INV_ARPPRO)) {
108 dprintf("ARP protocol address format mismatch.\n");
109 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
110 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
111 return 0;
112 }
113
114 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
115 ARPT_INV_ARPHLN)) {
116 dprintf("ARP hardware address length mismatch.\n");
117 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
118 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
119 return 0;
120 }
121
122 src_devaddr = arpptr;
123 arpptr += dev->addr_len;
124 memcpy(&src_ipaddr, arpptr, sizeof(u32));
125 arpptr += sizeof(u32);
126 tgt_devaddr = arpptr;
127 arpptr += dev->addr_len;
128 memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
129
130 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
131 ARPT_INV_SRCDEVADDR) ||
132 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
133 ARPT_INV_TGTDEVADDR)) {
134 dprintf("Source or target device address mismatch.\n");
135
136 return 0;
137 }
138
139 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
140 ARPT_INV_SRCIP) ||
141 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
142 ARPT_INV_TGTIP)) {
143 dprintf("Source or target IP address mismatch.\n");
144
145 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
146 NIPQUAD(src_ipaddr),
147 NIPQUAD(arpinfo->smsk.s_addr),
148 NIPQUAD(arpinfo->src.s_addr),
149 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
150 dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
151 NIPQUAD(tgt_ipaddr),
152 NIPQUAD(arpinfo->tmsk.s_addr),
153 NIPQUAD(arpinfo->tgt.s_addr),
154 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
155 return 0;
156 }
157
158 /* Look for ifname matches. */
159 for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
160 ret |= (indev[i] ^ arpinfo->iniface[i])
161 & arpinfo->iniface_mask[i];
162 }
163
164 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
165 dprintf("VIA in mismatch (%s vs %s).%s\n",
166 indev, arpinfo->iniface,
167 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
168 return 0;
169 }
170
171 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
172 unsigned long odev;
173 memcpy(&odev, outdev + i*sizeof(unsigned long),
174 sizeof(unsigned long));
175 ret |= (odev
176 ^ ((const unsigned long *)arpinfo->outiface)[i])
177 & ((const unsigned long *)arpinfo->outiface_mask)[i];
178 }
179
180 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
181 dprintf("VIA out mismatch (%s vs %s).%s\n",
182 outdev, arpinfo->outiface,
183 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
184 return 0;
185 }
186
187 return 1;
188 }
189
190 static inline int arp_checkentry(const struct arpt_arp *arp)
191 {
192 if (arp->flags & ~ARPT_F_MASK) {
193 duprintf("Unknown flag bits set: %08X\n",
194 arp->flags & ~ARPT_F_MASK);
195 return 0;
196 }
197 if (arp->invflags & ~ARPT_INV_MASK) {
198 duprintf("Unknown invflag bits set: %08X\n",
199 arp->invflags & ~ARPT_INV_MASK);
200 return 0;
201 }
202
203 return 1;
204 }
205
206 static unsigned int arpt_error(struct sk_buff **pskb,
207 const struct net_device *in,
208 const struct net_device *out,
209 unsigned int hooknum,
210 const struct xt_target *target,
211 const void *targinfo,
212 void *userinfo)
213 {
214 if (net_ratelimit())
215 printk("arp_tables: error: '%s'\n", (char *)targinfo);
216
217 return NF_DROP;
218 }
219
220 static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
221 {
222 return (struct arpt_entry *)(base + offset);
223 }
224
225 unsigned int arpt_do_table(struct sk_buff **pskb,
226 unsigned int hook,
227 const struct net_device *in,
228 const struct net_device *out,
229 struct arpt_table *table,
230 void *userdata)
231 {
232 static const char nulldevname[IFNAMSIZ];
233 unsigned int verdict = NF_DROP;
234 struct arphdr *arp;
235 int hotdrop = 0;
236 struct arpt_entry *e, *back;
237 const char *indev, *outdev;
238 void *table_base;
239 struct xt_table_info *private = table->private;
240
241 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
242 if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) +
243 (2 * (*pskb)->dev->addr_len) +
244 (2 * sizeof(u32)))))
245 return NF_DROP;
246
247 indev = in ? in->name : nulldevname;
248 outdev = out ? out->name : nulldevname;
249
250 read_lock_bh(&table->lock);
251 table_base = (void *)private->entries[smp_processor_id()];
252 e = get_entry(table_base, private->hook_entry[hook]);
253 back = get_entry(table_base, private->underflow[hook]);
254
255 arp = (*pskb)->nh.arph;
256 do {
257 if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) {
258 struct arpt_entry_target *t;
259 int hdr_len;
260
261 hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
262 (2 * (*pskb)->dev->addr_len);
263 ADD_COUNTER(e->counters, hdr_len, 1);
264
265 t = arpt_get_target(e);
266
267 /* Standard target? */
268 if (!t->u.kernel.target->target) {
269 int v;
270
271 v = ((struct arpt_standard_target *)t)->verdict;
272 if (v < 0) {
273 /* Pop from stack? */
274 if (v != ARPT_RETURN) {
275 verdict = (unsigned)(-v) - 1;
276 break;
277 }
278 e = back;
279 back = get_entry(table_base,
280 back->comefrom);
281 continue;
282 }
283 if (table_base + v
284 != (void *)e + e->next_offset) {
285 /* Save old back ptr in next entry */
286 struct arpt_entry *next
287 = (void *)e + e->next_offset;
288 next->comefrom =
289 (void *)back - table_base;
290
291 /* set back pointer to next entry */
292 back = next;
293 }
294
295 e = get_entry(table_base, v);
296 } else {
297 /* Targets which reenter must return
298 * abs. verdicts
299 */
300 verdict = t->u.kernel.target->target(pskb,
301 in, out,
302 hook,
303 t->u.kernel.target,
304 t->data,
305 userdata);
306
307 /* Target might have changed stuff. */
308 arp = (*pskb)->nh.arph;
309
310 if (verdict == ARPT_CONTINUE)
311 e = (void *)e + e->next_offset;
312 else
313 /* Verdict */
314 break;
315 }
316 } else {
317 e = (void *)e + e->next_offset;
318 }
319 } while (!hotdrop);
320 read_unlock_bh(&table->lock);
321
322 if (hotdrop)
323 return NF_DROP;
324 else
325 return verdict;
326 }
327
328 /* All zeroes == unconditional rule. */
329 static inline int unconditional(const struct arpt_arp *arp)
330 {
331 unsigned int i;
332
333 for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
334 if (((__u32 *)arp)[i])
335 return 0;
336
337 return 1;
338 }
339
340 /* Figures out from what hook each rule can be called: returns 0 if
341 * there are loops. Puts hook bitmask in comefrom.
342 */
343 static int mark_source_chains(struct xt_table_info *newinfo,
344 unsigned int valid_hooks, void *entry0)
345 {
346 unsigned int hook;
347
348 /* No recursion; use packet counter to save back ptrs (reset
349 * to 0 as we leave), and comefrom to save source hook bitmask.
350 */
351 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
352 unsigned int pos = newinfo->hook_entry[hook];
353 struct arpt_entry *e
354 = (struct arpt_entry *)(entry0 + pos);
355
356 if (!(valid_hooks & (1 << hook)))
357 continue;
358
359 /* Set initial back pointer. */
360 e->counters.pcnt = pos;
361
362 for (;;) {
363 struct arpt_standard_target *t
364 = (void *)arpt_get_target(e);
365
366 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
367 printk("arptables: loop hook %u pos %u %08X.\n",
368 hook, pos, e->comefrom);
369 return 0;
370 }
371 e->comefrom
372 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
373
374 /* Unconditional return/END. */
375 if (e->target_offset == sizeof(struct arpt_entry)
376 && (strcmp(t->target.u.user.name,
377 ARPT_STANDARD_TARGET) == 0)
378 && t->verdict < 0
379 && unconditional(&e->arp)) {
380 unsigned int oldpos, size;
381
382 /* Return: backtrack through the last
383 * big jump.
384 */
385 do {
386 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
387 oldpos = pos;
388 pos = e->counters.pcnt;
389 e->counters.pcnt = 0;
390
391 /* We're at the start. */
392 if (pos == oldpos)
393 goto next;
394
395 e = (struct arpt_entry *)
396 (entry0 + pos);
397 } while (oldpos == pos + e->next_offset);
398
399 /* Move along one */
400 size = e->next_offset;
401 e = (struct arpt_entry *)
402 (entry0 + pos + size);
403 e->counters.pcnt = pos;
404 pos += size;
405 } else {
406 int newpos = t->verdict;
407
408 if (strcmp(t->target.u.user.name,
409 ARPT_STANDARD_TARGET) == 0
410 && newpos >= 0) {
411 /* This a jump; chase it. */
412 duprintf("Jump rule %u -> %u\n",
413 pos, newpos);
414 } else {
415 /* ... this is a fallthru */
416 newpos = pos + e->next_offset;
417 }
418 e = (struct arpt_entry *)
419 (entry0 + newpos);
420 e->counters.pcnt = pos;
421 pos = newpos;
422 }
423 }
424 next:
425 duprintf("Finished chain %u\n", hook);
426 }
427 return 1;
428 }
429
430 static inline int standard_check(const struct arpt_entry_target *t,
431 unsigned int max_offset)
432 {
433 struct arpt_standard_target *targ = (void *)t;
434
435 /* Check standard info. */
436 if (t->u.target_size
437 != ARPT_ALIGN(sizeof(struct arpt_standard_target))) {
438 duprintf("arpt_standard_check: target size %u != %Zu\n",
439 t->u.target_size,
440 ARPT_ALIGN(sizeof(struct arpt_standard_target)));
441 return 0;
442 }
443
444 if (targ->verdict >= 0
445 && targ->verdict > max_offset - sizeof(struct arpt_entry)) {
446 duprintf("arpt_standard_check: bad verdict (%i)\n",
447 targ->verdict);
448 return 0;
449 }
450
451 if (targ->verdict < -NF_MAX_VERDICT - 1) {
452 duprintf("arpt_standard_check: bad negative verdict (%i)\n",
453 targ->verdict);
454 return 0;
455 }
456 return 1;
457 }
458
459 static struct arpt_target arpt_standard_target;
460
461 static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size,
462 unsigned int *i)
463 {
464 struct arpt_entry_target *t;
465 struct arpt_target *target;
466 int ret;
467
468 if (!arp_checkentry(&e->arp)) {
469 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
470 return -EINVAL;
471 }
472
473 t = arpt_get_target(e);
474 target = try_then_request_module(xt_find_target(NF_ARP, t->u.user.name,
475 t->u.user.revision),
476 "arpt_%s", t->u.user.name);
477 if (IS_ERR(target) || !target) {
478 duprintf("check_entry: `%s' not found\n", t->u.user.name);
479 ret = target ? PTR_ERR(target) : -ENOENT;
480 goto out;
481 }
482 t->u.kernel.target = target;
483
484 ret = xt_check_target(target, NF_ARP, t->u.target_size - sizeof(*t),
485 name, e->comefrom, 0, 0);
486 if (ret)
487 goto err;
488
489 if (t->u.kernel.target == &arpt_standard_target) {
490 if (!standard_check(t, size)) {
491 ret = -EINVAL;
492 goto out;
493 }
494 } else if (t->u.kernel.target->checkentry
495 && !t->u.kernel.target->checkentry(name, e, target, t->data,
496 t->u.target_size
497 - sizeof(*t),
498 e->comefrom)) {
499 duprintf("arp_tables: check failed for `%s'.\n",
500 t->u.kernel.target->name);
501 ret = -EINVAL;
502 goto err;
503 }
504
505 (*i)++;
506 return 0;
507 err:
508 module_put(t->u.kernel.target->me);
509 out:
510 return ret;
511 }
512
513 static inline int check_entry_size_and_hooks(struct arpt_entry *e,
514 struct xt_table_info *newinfo,
515 unsigned char *base,
516 unsigned char *limit,
517 const unsigned int *hook_entries,
518 const unsigned int *underflows,
519 unsigned int *i)
520 {
521 unsigned int h;
522
523 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
524 || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
525 duprintf("Bad offset %p\n", e);
526 return -EINVAL;
527 }
528
529 if (e->next_offset
530 < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
531 duprintf("checking: element %p size %u\n",
532 e, e->next_offset);
533 return -EINVAL;
534 }
535
536 /* Check hooks & underflows */
537 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
538 if ((unsigned char *)e - base == hook_entries[h])
539 newinfo->hook_entry[h] = hook_entries[h];
540 if ((unsigned char *)e - base == underflows[h])
541 newinfo->underflow[h] = underflows[h];
542 }
543
544 /* FIXME: underflows must be unconditional, standard verdicts
545 < 0 (not ARPT_RETURN). --RR */
546
547 /* Clear counters and comefrom */
548 e->counters = ((struct xt_counters) { 0, 0 });
549 e->comefrom = 0;
550
551 (*i)++;
552 return 0;
553 }
554
555 static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
556 {
557 struct arpt_entry_target *t;
558
559 if (i && (*i)-- == 0)
560 return 1;
561
562 t = arpt_get_target(e);
563 if (t->u.kernel.target->destroy)
564 t->u.kernel.target->destroy(t->u.kernel.target, t->data,
565 t->u.target_size - sizeof(*t));
566 module_put(t->u.kernel.target->me);
567 return 0;
568 }
569
570 /* Checks and translates the user-supplied table segment (held in
571 * newinfo).
572 */
573 static int translate_table(const char *name,
574 unsigned int valid_hooks,
575 struct xt_table_info *newinfo,
576 void *entry0,
577 unsigned int size,
578 unsigned int number,
579 const unsigned int *hook_entries,
580 const unsigned int *underflows)
581 {
582 unsigned int i;
583 int ret;
584
585 newinfo->size = size;
586 newinfo->number = number;
587
588 /* Init all hooks to impossible value. */
589 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
590 newinfo->hook_entry[i] = 0xFFFFFFFF;
591 newinfo->underflow[i] = 0xFFFFFFFF;
592 }
593
594 duprintf("translate_table: size %u\n", newinfo->size);
595 i = 0;
596
597 /* Walk through entries, checking offsets. */
598 ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
599 check_entry_size_and_hooks,
600 newinfo,
601 entry0,
602 entry0 + size,
603 hook_entries, underflows, &i);
604 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
605 if (ret != 0)
606 return ret;
607
608 if (i != number) {
609 duprintf("translate_table: %u not %u entries\n",
610 i, number);
611 return -EINVAL;
612 }
613
614 /* Check hooks all assigned */
615 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
616 /* Only hooks which are valid */
617 if (!(valid_hooks & (1 << i)))
618 continue;
619 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
620 duprintf("Invalid hook entry %u %u\n",
621 i, hook_entries[i]);
622 return -EINVAL;
623 }
624 if (newinfo->underflow[i] == 0xFFFFFFFF) {
625 duprintf("Invalid underflow %u %u\n",
626 i, underflows[i]);
627 return -EINVAL;
628 }
629 }
630
631 if (!mark_source_chains(newinfo, valid_hooks, entry0)) {
632 duprintf("Looping hook\n");
633 return -ELOOP;
634 }
635
636 /* Finally, each sanity check must pass */
637 i = 0;
638 ret = ARPT_ENTRY_ITERATE(entry0, newinfo->size,
639 check_entry, name, size, &i);
640
641 if (ret != 0) {
642 ARPT_ENTRY_ITERATE(entry0, newinfo->size,
643 cleanup_entry, &i);
644 return ret;
645 }
646
647 /* And one copy for every other CPU */
648 for_each_possible_cpu(i) {
649 if (newinfo->entries[i] && newinfo->entries[i] != entry0)
650 memcpy(newinfo->entries[i], entry0, newinfo->size);
651 }
652
653 return ret;
654 }
655
656 /* Gets counters. */
657 static inline int add_entry_to_counter(const struct arpt_entry *e,
658 struct xt_counters total[],
659 unsigned int *i)
660 {
661 ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
662
663 (*i)++;
664 return 0;
665 }
666
667 static inline int set_entry_to_counter(const struct arpt_entry *e,
668 struct xt_counters total[],
669 unsigned int *i)
670 {
671 SET_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
672
673 (*i)++;
674 return 0;
675 }
676
677 static void get_counters(const struct xt_table_info *t,
678 struct xt_counters counters[])
679 {
680 unsigned int cpu;
681 unsigned int i;
682 unsigned int curcpu;
683
684 /* Instead of clearing (by a previous call to memset())
685 * the counters and using adds, we set the counters
686 * with data used by 'current' CPU
687 * We dont care about preemption here.
688 */
689 curcpu = raw_smp_processor_id();
690
691 i = 0;
692 ARPT_ENTRY_ITERATE(t->entries[curcpu],
693 t->size,
694 set_entry_to_counter,
695 counters,
696 &i);
697
698 for_each_possible_cpu(cpu) {
699 if (cpu == curcpu)
700 continue;
701 i = 0;
702 ARPT_ENTRY_ITERATE(t->entries[cpu],
703 t->size,
704 add_entry_to_counter,
705 counters,
706 &i);
707 }
708 }
709
710 static int copy_entries_to_user(unsigned int total_size,
711 struct arpt_table *table,
712 void __user *userptr)
713 {
714 unsigned int off, num, countersize;
715 struct arpt_entry *e;
716 struct xt_counters *counters;
717 struct xt_table_info *private = table->private;
718 int ret = 0;
719 void *loc_cpu_entry;
720
721 /* We need atomic snapshot of counters: rest doesn't change
722 * (other than comefrom, which userspace doesn't care
723 * about).
724 */
725 countersize = sizeof(struct xt_counters) * private->number;
726 counters = vmalloc_node(countersize, numa_node_id());
727
728 if (counters == NULL)
729 return -ENOMEM;
730
731 /* First, sum counters... */
732 write_lock_bh(&table->lock);
733 get_counters(private, counters);
734 write_unlock_bh(&table->lock);
735
736 loc_cpu_entry = private->entries[raw_smp_processor_id()];
737 /* ... then copy entire thing ... */
738 if (copy_to_user(userptr, loc_cpu_entry, total_size) != 0) {
739 ret = -EFAULT;
740 goto free_counters;
741 }
742
743 /* FIXME: use iterator macros --RR */
744 /* ... then go back and fix counters and names */
745 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
746 struct arpt_entry_target *t;
747
748 e = (struct arpt_entry *)(loc_cpu_entry + off);
749 if (copy_to_user(userptr + off
750 + offsetof(struct arpt_entry, counters),
751 &counters[num],
752 sizeof(counters[num])) != 0) {
753 ret = -EFAULT;
754 goto free_counters;
755 }
756
757 t = arpt_get_target(e);
758 if (copy_to_user(userptr + off + e->target_offset
759 + offsetof(struct arpt_entry_target,
760 u.user.name),
761 t->u.kernel.target->name,
762 strlen(t->u.kernel.target->name)+1) != 0) {
763 ret = -EFAULT;
764 goto free_counters;
765 }
766 }
767
768 free_counters:
769 vfree(counters);
770 return ret;
771 }
772
773 static int get_entries(const struct arpt_get_entries *entries,
774 struct arpt_get_entries __user *uptr)
775 {
776 int ret;
777 struct arpt_table *t;
778
779 t = xt_find_table_lock(NF_ARP, entries->name);
780 if (t && !IS_ERR(t)) {
781 struct xt_table_info *private = t->private;
782 duprintf("t->private->number = %u\n",
783 private->number);
784 if (entries->size == private->size)
785 ret = copy_entries_to_user(private->size,
786 t, uptr->entrytable);
787 else {
788 duprintf("get_entries: I've got %u not %u!\n",
789 private->size, entries->size);
790 ret = -EINVAL;
791 }
792 module_put(t->me);
793 xt_table_unlock(t);
794 } else
795 ret = t ? PTR_ERR(t) : -ENOENT;
796
797 return ret;
798 }
799
800 static int do_replace(void __user *user, unsigned int len)
801 {
802 int ret;
803 struct arpt_replace tmp;
804 struct arpt_table *t;
805 struct xt_table_info *newinfo, *oldinfo;
806 struct xt_counters *counters;
807 void *loc_cpu_entry, *loc_cpu_old_entry;
808
809 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
810 return -EFAULT;
811
812 /* Hack: Causes ipchains to give correct error msg --RR */
813 if (len != sizeof(tmp) + tmp.size)
814 return -ENOPROTOOPT;
815
816 /* overflow check */
817 if (tmp.size >= (INT_MAX - sizeof(struct xt_table_info)) / NR_CPUS -
818 SMP_CACHE_BYTES)
819 return -ENOMEM;
820 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters))
821 return -ENOMEM;
822
823 newinfo = xt_alloc_table_info(tmp.size);
824 if (!newinfo)
825 return -ENOMEM;
826
827 /* choose the copy that is on our node/cpu */
828 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
829 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp),
830 tmp.size) != 0) {
831 ret = -EFAULT;
832 goto free_newinfo;
833 }
834
835 counters = vmalloc(tmp.num_counters * sizeof(struct xt_counters));
836 if (!counters) {
837 ret = -ENOMEM;
838 goto free_newinfo;
839 }
840
841 ret = translate_table(tmp.name, tmp.valid_hooks,
842 newinfo, loc_cpu_entry, tmp.size, tmp.num_entries,
843 tmp.hook_entry, tmp.underflow);
844 if (ret != 0)
845 goto free_newinfo_counters;
846
847 duprintf("arp_tables: Translated table\n");
848
849 t = try_then_request_module(xt_find_table_lock(NF_ARP, tmp.name),
850 "arptable_%s", tmp.name);
851 if (!t || IS_ERR(t)) {
852 ret = t ? PTR_ERR(t) : -ENOENT;
853 goto free_newinfo_counters_untrans;
854 }
855
856 /* You lied! */
857 if (tmp.valid_hooks != t->valid_hooks) {
858 duprintf("Valid hook crap: %08X vs %08X\n",
859 tmp.valid_hooks, t->valid_hooks);
860 ret = -EINVAL;
861 goto put_module;
862 }
863
864 oldinfo = xt_replace_table(t, tmp.num_counters, newinfo, &ret);
865 if (!oldinfo)
866 goto put_module;
867
868 /* Update module usage count based on number of rules */
869 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
870 oldinfo->number, oldinfo->initial_entries, newinfo->number);
871 if ((oldinfo->number > oldinfo->initial_entries) ||
872 (newinfo->number <= oldinfo->initial_entries))
873 module_put(t->me);
874 if ((oldinfo->number > oldinfo->initial_entries) &&
875 (newinfo->number <= oldinfo->initial_entries))
876 module_put(t->me);
877
878 /* Get the old counters. */
879 get_counters(oldinfo, counters);
880 /* Decrease module usage counts and free resource */
881 loc_cpu_old_entry = oldinfo->entries[raw_smp_processor_id()];
882 ARPT_ENTRY_ITERATE(loc_cpu_old_entry, oldinfo->size, cleanup_entry,NULL);
883
884 xt_free_table_info(oldinfo);
885 if (copy_to_user(tmp.counters, counters,
886 sizeof(struct xt_counters) * tmp.num_counters) != 0)
887 ret = -EFAULT;
888 vfree(counters);
889 xt_table_unlock(t);
890 return ret;
891
892 put_module:
893 module_put(t->me);
894 xt_table_unlock(t);
895 free_newinfo_counters_untrans:
896 ARPT_ENTRY_ITERATE(loc_cpu_entry, newinfo->size, cleanup_entry, NULL);
897 free_newinfo_counters:
898 vfree(counters);
899 free_newinfo:
900 xt_free_table_info(newinfo);
901 return ret;
902 }
903
904 /* We're lazy, and add to the first CPU; overflow works its fey magic
905 * and everything is OK.
906 */
907 static inline int add_counter_to_entry(struct arpt_entry *e,
908 const struct xt_counters addme[],
909 unsigned int *i)
910 {
911
912 ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
913
914 (*i)++;
915 return 0;
916 }
917
918 static int do_add_counters(void __user *user, unsigned int len)
919 {
920 unsigned int i;
921 struct xt_counters_info tmp, *paddc;
922 struct arpt_table *t;
923 struct xt_table_info *private;
924 int ret = 0;
925 void *loc_cpu_entry;
926
927 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
928 return -EFAULT;
929
930 if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct xt_counters))
931 return -EINVAL;
932
933 paddc = vmalloc(len);
934 if (!paddc)
935 return -ENOMEM;
936
937 if (copy_from_user(paddc, user, len) != 0) {
938 ret = -EFAULT;
939 goto free;
940 }
941
942 t = xt_find_table_lock(NF_ARP, tmp.name);
943 if (!t || IS_ERR(t)) {
944 ret = t ? PTR_ERR(t) : -ENOENT;
945 goto free;
946 }
947
948 write_lock_bh(&t->lock);
949 private = t->private;
950 if (private->number != tmp.num_counters) {
951 ret = -EINVAL;
952 goto unlock_up_free;
953 }
954
955 i = 0;
956 /* Choose the copy that is on our node */
957 loc_cpu_entry = private->entries[smp_processor_id()];
958 ARPT_ENTRY_ITERATE(loc_cpu_entry,
959 private->size,
960 add_counter_to_entry,
961 paddc->counters,
962 &i);
963 unlock_up_free:
964 write_unlock_bh(&t->lock);
965 xt_table_unlock(t);
966 module_put(t->me);
967 free:
968 vfree(paddc);
969
970 return ret;
971 }
972
973 static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
974 {
975 int ret;
976
977 if (!capable(CAP_NET_ADMIN))
978 return -EPERM;
979
980 switch (cmd) {
981 case ARPT_SO_SET_REPLACE:
982 ret = do_replace(user, len);
983 break;
984
985 case ARPT_SO_SET_ADD_COUNTERS:
986 ret = do_add_counters(user, len);
987 break;
988
989 default:
990 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
991 ret = -EINVAL;
992 }
993
994 return ret;
995 }
996
997 static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
998 {
999 int ret;
1000
1001 if (!capable(CAP_NET_ADMIN))
1002 return -EPERM;
1003
1004 switch (cmd) {
1005 case ARPT_SO_GET_INFO: {
1006 char name[ARPT_TABLE_MAXNAMELEN];
1007 struct arpt_table *t;
1008
1009 if (*len != sizeof(struct arpt_getinfo)) {
1010 duprintf("length %u != %Zu\n", *len,
1011 sizeof(struct arpt_getinfo));
1012 ret = -EINVAL;
1013 break;
1014 }
1015
1016 if (copy_from_user(name, user, sizeof(name)) != 0) {
1017 ret = -EFAULT;
1018 break;
1019 }
1020 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
1021
1022 t = try_then_request_module(xt_find_table_lock(NF_ARP, name),
1023 "arptable_%s", name);
1024 if (t && !IS_ERR(t)) {
1025 struct arpt_getinfo info;
1026 struct xt_table_info *private = t->private;
1027
1028 info.valid_hooks = t->valid_hooks;
1029 memcpy(info.hook_entry, private->hook_entry,
1030 sizeof(info.hook_entry));
1031 memcpy(info.underflow, private->underflow,
1032 sizeof(info.underflow));
1033 info.num_entries = private->number;
1034 info.size = private->size;
1035 strcpy(info.name, name);
1036
1037 if (copy_to_user(user, &info, *len) != 0)
1038 ret = -EFAULT;
1039 else
1040 ret = 0;
1041 xt_table_unlock(t);
1042 module_put(t->me);
1043 } else
1044 ret = t ? PTR_ERR(t) : -ENOENT;
1045 }
1046 break;
1047
1048 case ARPT_SO_GET_ENTRIES: {
1049 struct arpt_get_entries get;
1050
1051 if (*len < sizeof(get)) {
1052 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
1053 ret = -EINVAL;
1054 } else if (copy_from_user(&get, user, sizeof(get)) != 0) {
1055 ret = -EFAULT;
1056 } else if (*len != sizeof(struct arpt_get_entries) + get.size) {
1057 duprintf("get_entries: %u != %Zu\n", *len,
1058 sizeof(struct arpt_get_entries) + get.size);
1059 ret = -EINVAL;
1060 } else
1061 ret = get_entries(&get, user);
1062 break;
1063 }
1064
1065 case ARPT_SO_GET_REVISION_TARGET: {
1066 struct xt_get_revision rev;
1067
1068 if (*len != sizeof(rev)) {
1069 ret = -EINVAL;
1070 break;
1071 }
1072 if (copy_from_user(&rev, user, sizeof(rev)) != 0) {
1073 ret = -EFAULT;
1074 break;
1075 }
1076
1077 try_then_request_module(xt_find_revision(NF_ARP, rev.name,
1078 rev.revision, 1, &ret),
1079 "arpt_%s", rev.name);
1080 break;
1081 }
1082
1083 default:
1084 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1085 ret = -EINVAL;
1086 }
1087
1088 return ret;
1089 }
1090
1091 int arpt_register_table(struct arpt_table *table,
1092 const struct arpt_replace *repl)
1093 {
1094 int ret;
1095 struct xt_table_info *newinfo;
1096 static struct xt_table_info bootstrap
1097 = { 0, 0, 0, { 0 }, { 0 }, { } };
1098 void *loc_cpu_entry;
1099
1100 newinfo = xt_alloc_table_info(repl->size);
1101 if (!newinfo) {
1102 ret = -ENOMEM;
1103 return ret;
1104 }
1105
1106 /* choose the copy on our node/cpu */
1107 loc_cpu_entry = newinfo->entries[raw_smp_processor_id()];
1108 memcpy(loc_cpu_entry, repl->entries, repl->size);
1109
1110 ret = translate_table(table->name, table->valid_hooks,
1111 newinfo, loc_cpu_entry, repl->size,
1112 repl->num_entries,
1113 repl->hook_entry,
1114 repl->underflow);
1115
1116 duprintf("arpt_register_table: translate table gives %d\n", ret);
1117 if (ret != 0) {
1118 xt_free_table_info(newinfo);
1119 return ret;
1120 }
1121
1122 ret = xt_register_table(table, &bootstrap, newinfo);
1123 if (ret != 0) {
1124 xt_free_table_info(newinfo);
1125 return ret;
1126 }
1127
1128 return 0;
1129 }
1130
1131 void arpt_unregister_table(struct arpt_table *table)
1132 {
1133 struct xt_table_info *private;
1134 void *loc_cpu_entry;
1135
1136 private = xt_unregister_table(table);
1137
1138 /* Decrease module usage counts and free resources */
1139 loc_cpu_entry = private->entries[raw_smp_processor_id()];
1140 ARPT_ENTRY_ITERATE(loc_cpu_entry, private->size,
1141 cleanup_entry, NULL);
1142 xt_free_table_info(private);
1143 }
1144
1145 /* The built-in targets: standard (NULL) and error. */
1146 static struct arpt_target arpt_standard_target = {
1147 .name = ARPT_STANDARD_TARGET,
1148 .targetsize = sizeof(int),
1149 .family = NF_ARP,
1150 };
1151
1152 static struct arpt_target arpt_error_target = {
1153 .name = ARPT_ERROR_TARGET,
1154 .target = arpt_error,
1155 .targetsize = ARPT_FUNCTION_MAXNAMELEN,
1156 .family = NF_ARP,
1157 };
1158
1159 static struct nf_sockopt_ops arpt_sockopts = {
1160 .pf = PF_INET,
1161 .set_optmin = ARPT_BASE_CTL,
1162 .set_optmax = ARPT_SO_SET_MAX+1,
1163 .set = do_arpt_set_ctl,
1164 .get_optmin = ARPT_BASE_CTL,
1165 .get_optmax = ARPT_SO_GET_MAX+1,
1166 .get = do_arpt_get_ctl,
1167 };
1168
1169 static int __init arp_tables_init(void)
1170 {
1171 int ret;
1172
1173 ret = xt_proto_init(NF_ARP);
1174 if (ret < 0)
1175 goto err1;
1176
1177 /* Noone else will be downing sem now, so we won't sleep */
1178 ret = xt_register_target(&arpt_standard_target);
1179 if (ret < 0)
1180 goto err2;
1181 ret = xt_register_target(&arpt_error_target);
1182 if (ret < 0)
1183 goto err3;
1184
1185 /* Register setsockopt */
1186 ret = nf_register_sockopt(&arpt_sockopts);
1187 if (ret < 0)
1188 goto err4;
1189
1190 printk("arp_tables: (C) 2002 David S. Miller\n");
1191 return 0;
1192
1193 err4:
1194 xt_unregister_target(&arpt_error_target);
1195 err3:
1196 xt_unregister_target(&arpt_standard_target);
1197 err2:
1198 xt_proto_fini(NF_ARP);
1199 err1:
1200 return ret;
1201 }
1202
1203 static void __exit arp_tables_fini(void)
1204 {
1205 nf_unregister_sockopt(&arpt_sockopts);
1206 xt_proto_fini(NF_ARP);
1207 }
1208
1209 EXPORT_SYMBOL(arpt_register_table);
1210 EXPORT_SYMBOL(arpt_unregister_table);
1211 EXPORT_SYMBOL(arpt_do_table);
1212
1213 module_init(arp_tables_init);
1214 module_exit(arp_tables_fini);
Linus' kernel tree