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[GitHub/mt8127/android_kernel_alcatel_ttab.git] / net / ipv4 / netfilter / arp_tables.c
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1da177e4
LT		 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/config.h>
13#include <linux/kernel.h>
14#include <linux/skbuff.h>
15#include <linux/netdevice.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 <asm/semaphore.h>
25
26#include <linux/netfilter_arp/arp_tables.h>
27
28MODULE_LICENSE("GPL");
29MODULE_AUTHOR("David S. Miller <davem@redhat.com>");
30MODULE_DESCRIPTION("arptables core");
31
32/*#define DEBUG_ARP_TABLES*/
33/*#define DEBUG_ARP_TABLES_USER*/
34
35#ifdef DEBUG_ARP_TABLES
36#define dprintf(format, args...) printk(format , ## args)
37#else
38#define dprintf(format, args...)
39#endif
40
41#ifdef DEBUG_ARP_TABLES_USER
42#define duprintf(format, args...) printk(format , ## args)
43#else
44#define duprintf(format, args...)
45#endif
46
47#ifdef CONFIG_NETFILTER_DEBUG
48#define ARP_NF_ASSERT(x) \
49do { \
50 if (!(x)) \
51 printk("ARP_NF_ASSERT: %s:%s:%u\n", \
52 __FUNCTION__, __FILE__, __LINE__); \
53} while(0)
54#else
55#define ARP_NF_ASSERT(x)
56#endif
57#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))
58
59static DECLARE_MUTEX(arpt_mutex);
60
61#define ASSERT_READ_LOCK(x) ARP_NF_ASSERT(down_trylock(&arpt_mutex) != 0)
62#define ASSERT_WRITE_LOCK(x) ARP_NF_ASSERT(down_trylock(&arpt_mutex) != 0)
1da177e4
LT		 63#include <linux/netfilter_ipv4/listhelp.h>
64
65struct arpt_table_info {
66 unsigned int size;
67 unsigned int number;
68 unsigned int initial_entries;
69 unsigned int hook_entry[NF_ARP_NUMHOOKS];
70 unsigned int underflow[NF_ARP_NUMHOOKS];
71 char entries[0] __attribute__((aligned(SMP_CACHE_BYTES)));
72};
73
74static LIST_HEAD(arpt_target);
75static LIST_HEAD(arpt_tables);
76#define ADD_COUNTER(c,b,p) do { (c).bcnt += (b); (c).pcnt += (p); } while(0)
77
78#ifdef CONFIG_SMP
79#define TABLE_OFFSET(t,p) (SMP_ALIGN((t)->size)*(p))
80#else
81#define TABLE_OFFSET(t,p) 0
82#endif
83
84static inline int arp_devaddr_compare(const struct arpt_devaddr_info *ap,
85 char *hdr_addr, int len)
86{
87 int i, ret;
88
89 if (len > ARPT_DEV_ADDR_LEN_MAX)
90 len = ARPT_DEV_ADDR_LEN_MAX;
91
92 ret = 0;
93 for (i = 0; i < len; i++)
94 ret |= (hdr_addr[i] ^ ap->addr[i]) & ap->mask[i];
95
96 return (ret != 0);
97}
98
99/* Returns whether packet matches rule or not. */
100static inline int arp_packet_match(const struct arphdr *arphdr,
101 struct net_device *dev,
102 const char *indev,
103 const char *outdev,
104 const struct arpt_arp *arpinfo)
105{
106 char *arpptr = (char *)(arphdr + 1);
107 char *src_devaddr, *tgt_devaddr;
108 u32 src_ipaddr, tgt_ipaddr;
109 int i, ret;
110
111#define FWINV(bool,invflg) ((bool) ^ !!(arpinfo->invflags & invflg))
112
113 if (FWINV((arphdr->ar_op & arpinfo->arpop_mask) != arpinfo->arpop,
114 ARPT_INV_ARPOP)) {
115 dprintf("ARP operation field mismatch.\n");
116 dprintf("ar_op: %04x info->arpop: %04x info->arpop_mask: %04x\n",
117 arphdr->ar_op, arpinfo->arpop, arpinfo->arpop_mask);
118 return 0;
119 }
120
121 if (FWINV((arphdr->ar_hrd & arpinfo->arhrd_mask) != arpinfo->arhrd,
122 ARPT_INV_ARPHRD)) {
123 dprintf("ARP hardware address format mismatch.\n");
124 dprintf("ar_hrd: %04x info->arhrd: %04x info->arhrd_mask: %04x\n",
125 arphdr->ar_hrd, arpinfo->arhrd, arpinfo->arhrd_mask);
126 return 0;
127 }
128
129 if (FWINV((arphdr->ar_pro & arpinfo->arpro_mask) != arpinfo->arpro,
130 ARPT_INV_ARPPRO)) {
131 dprintf("ARP protocol address format mismatch.\n");
132 dprintf("ar_pro: %04x info->arpro: %04x info->arpro_mask: %04x\n",
133 arphdr->ar_pro, arpinfo->arpro, arpinfo->arpro_mask);
134 return 0;
135 }
136
137 if (FWINV((arphdr->ar_hln & arpinfo->arhln_mask) != arpinfo->arhln,
138 ARPT_INV_ARPHLN)) {
139 dprintf("ARP hardware address length mismatch.\n");
140 dprintf("ar_hln: %02x info->arhln: %02x info->arhln_mask: %02x\n",
141 arphdr->ar_hln, arpinfo->arhln, arpinfo->arhln_mask);
142 return 0;
143 }
144
145 src_devaddr = arpptr;
146 arpptr += dev->addr_len;
147 memcpy(&src_ipaddr, arpptr, sizeof(u32));
148 arpptr += sizeof(u32);
149 tgt_devaddr = arpptr;
150 arpptr += dev->addr_len;
151 memcpy(&tgt_ipaddr, arpptr, sizeof(u32));
152
153 if (FWINV(arp_devaddr_compare(&arpinfo->src_devaddr, src_devaddr, dev->addr_len),
154 ARPT_INV_SRCDEVADDR) ||
155 FWINV(arp_devaddr_compare(&arpinfo->tgt_devaddr, tgt_devaddr, dev->addr_len),
156 ARPT_INV_TGTDEVADDR)) {
157 dprintf("Source or target device address mismatch.\n");
158
159 return 0;
160 }
161
162 if (FWINV((src_ipaddr & arpinfo->smsk.s_addr) != arpinfo->src.s_addr,
163 ARPT_INV_SRCIP) ||
164 FWINV(((tgt_ipaddr & arpinfo->tmsk.s_addr) != arpinfo->tgt.s_addr),
165 ARPT_INV_TGTIP)) {
166 dprintf("Source or target IP address mismatch.\n");
167
168 dprintf("SRC: %u.%u.%u.%u. Mask: %u.%u.%u.%u. Target: %u.%u.%u.%u.%s\n",
169 NIPQUAD(src_ipaddr),
170 NIPQUAD(arpinfo->smsk.s_addr),
171 NIPQUAD(arpinfo->src.s_addr),
172 arpinfo->invflags & ARPT_INV_SRCIP ? " (INV)" : "");
173 dprintf("TGT: %u.%u.%u.%u Mask: %u.%u.%u.%u Target: %u.%u.%u.%u.%s\n",
174 NIPQUAD(tgt_ipaddr),
175 NIPQUAD(arpinfo->tmsk.s_addr),
176 NIPQUAD(arpinfo->tgt.s_addr),
177 arpinfo->invflags & ARPT_INV_TGTIP ? " (INV)" : "");
178 return 0;
179 }
180
181 /* Look for ifname matches. */
182 for (i = 0, ret = 0; i < IFNAMSIZ; i++) {
183 ret |= (indev[i] ^ arpinfo->iniface[i])
184 & arpinfo->iniface_mask[i];
185 }
186
187 if (FWINV(ret != 0, ARPT_INV_VIA_IN)) {
188 dprintf("VIA in mismatch (%s vs %s).%s\n",
189 indev, arpinfo->iniface,
190 arpinfo->invflags&ARPT_INV_VIA_IN ?" (INV)":"");
191 return 0;
192 }
193
194 for (i = 0, ret = 0; i < IFNAMSIZ/sizeof(unsigned long); i++) {
195 unsigned long odev;
196 memcpy(&odev, outdev + i*sizeof(unsigned long),
197 sizeof(unsigned long));
198 ret |= (odev
199 ^ ((const unsigned long *)arpinfo->outiface)[i])
200 & ((const unsigned long *)arpinfo->outiface_mask)[i];
201 }
202
203 if (FWINV(ret != 0, ARPT_INV_VIA_OUT)) {
204 dprintf("VIA out mismatch (%s vs %s).%s\n",
205 outdev, arpinfo->outiface,
206 arpinfo->invflags&ARPT_INV_VIA_OUT ?" (INV)":"");
207 return 0;
208 }
209
210 return 1;
211}
212
213static inline int arp_checkentry(const struct arpt_arp *arp)
214{
215 if (arp->flags & ~ARPT_F_MASK) {
216 duprintf("Unknown flag bits set: %08X\n",
217 arp->flags & ~ARPT_F_MASK);
218 return 0;
219 }
220 if (arp->invflags & ~ARPT_INV_MASK) {
221 duprintf("Unknown invflag bits set: %08X\n",
222 arp->invflags & ~ARPT_INV_MASK);
223 return 0;
224 }
225
226 return 1;
227}
228
229static unsigned int arpt_error(struct sk_buff **pskb,
230 unsigned int hooknum,
231 const struct net_device *in,
232 const struct net_device *out,
233 const void *targinfo,
234 void *userinfo)
235{
236 if (net_ratelimit())
237 printk("arp_tables: error: '%s'\n", (char *)targinfo);
238
239 return NF_DROP;
240}
241
242static inline struct arpt_entry *get_entry(void *base, unsigned int offset)
243{
244 return (struct arpt_entry *)(base + offset);
245}
246
247unsigned int arpt_do_table(struct sk_buff **pskb,
248 unsigned int hook,
249 const struct net_device *in,
250 const struct net_device *out,
251 struct arpt_table *table,
252 void *userdata)
253{
254 static const char nulldevname[IFNAMSIZ];
255 unsigned int verdict = NF_DROP;
256 struct arphdr *arp;
257 int hotdrop = 0;
258 struct arpt_entry *e, *back;
259 const char *indev, *outdev;
260 void *table_base;
261
262 /* ARP header, plus 2 device addresses, plus 2 IP addresses. */
263 if (!pskb_may_pull((*pskb), (sizeof(struct arphdr) +
264 (2 * (*pskb)->dev->addr_len) +
265 (2 * sizeof(u32)))))
266 return NF_DROP;
267
268 indev = in ? in->name : nulldevname;
269 outdev = out ? out->name : nulldevname;
270
271 read_lock_bh(&table->lock);
272 table_base = (void *)table->private->entries
273 + TABLE_OFFSET(table->private,
274 smp_processor_id());
275 e = get_entry(table_base, table->private->hook_entry[hook]);
276 back = get_entry(table_base, table->private->underflow[hook]);
277
278 arp = (*pskb)->nh.arph;
279 do {
280 if (arp_packet_match(arp, (*pskb)->dev, indev, outdev, &e->arp)) {
281 struct arpt_entry_target *t;
282 int hdr_len;
283
284 hdr_len = sizeof(*arp) + (2 * sizeof(struct in_addr)) +
285 (2 * (*pskb)->dev->addr_len);
286 ADD_COUNTER(e->counters, hdr_len, 1);
287
288 t = arpt_get_target(e);
289
290 /* Standard target? */
291 if (!t->u.kernel.target->target) {
292 int v;
293
294 v = ((struct arpt_standard_target *)t)->verdict;
295 if (v < 0) {
296 /* Pop from stack? */
297 if (v != ARPT_RETURN) {
298 verdict = (unsigned)(-v) - 1;
299 break;
300 }
301 e = back;
302 back = get_entry(table_base,
303 back->comefrom);
304 continue;
305 }
306 if (table_base + v
307 != (void *)e + e->next_offset) {
308 /* Save old back ptr in next entry */
309 struct arpt_entry *next
310 = (void *)e + e->next_offset;
311 next->comefrom =
312 (void *)back - table_base;
313
314 /* set back pointer to next entry */
315 back = next;
316 }
317
318 e = get_entry(table_base, v);
319 } else {
320 /* Targets which reenter must return
321 * abs. verdicts
322 */
323 verdict = t->u.kernel.target->target(pskb,
324 hook,
325 in, out,
326 t->data,
327 userdata);
328
329 /* Target might have changed stuff. */
330 arp = (*pskb)->nh.arph;
331
332 if (verdict == ARPT_CONTINUE)
333 e = (void *)e + e->next_offset;
334 else
335 /* Verdict */
336 break;
337 }
338 } else {
339 e = (void *)e + e->next_offset;
340 }
341 } while (!hotdrop);
342 read_unlock_bh(&table->lock);
343
344 if (hotdrop)
345 return NF_DROP;
346 else
347 return verdict;
348}
349
350static inline void *find_inlist_lock_noload(struct list_head *head,
351 const char *name,
352 int *error,
353 struct semaphore *mutex)
354{
355 void *ret;
356
357 *error = down_interruptible(mutex);
358 if (*error != 0)
359 return NULL;
360
361 ret = list_named_find(head, name);
362 if (!ret) {
363 *error = -ENOENT;
364 up(mutex);
365 }
366 return ret;
367}
368
369#ifndef CONFIG_KMOD
370#define find_inlist_lock(h,n,p,e,m) find_inlist_lock_noload((h),(n),(e),(m))
371#else
372static void *
373find_inlist_lock(struct list_head *head,
374 const char *name,
375 const char *prefix,
376 int *error,
377 struct semaphore *mutex)
378{
379 void *ret;
380
381 ret = find_inlist_lock_noload(head, name, error, mutex);
382 if (!ret) {
383 duprintf("find_inlist: loading `%s%s'.\n", prefix, name);
384 request_module("%s%s", prefix, name);
385 ret = find_inlist_lock_noload(head, name, error, mutex);
386 }
387
388 return ret;
389}
390#endif
391
392static inline struct arpt_table *arpt_find_table_lock(const char *name, int *error, struct semaphore *mutex)
393{
394 return find_inlist_lock(&arpt_tables, name, "arptable_", error, mutex);
395}
396
397static struct arpt_target *arpt_find_target_lock(const char *name, int *error, struct semaphore *mutex)
398{
399 return find_inlist_lock(&arpt_target, name, "arpt_", error, mutex);
400}
401
402/* All zeroes == unconditional rule. */
403static inline int unconditional(const struct arpt_arp *arp)
404{
405 unsigned int i;
406
407 for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++)
408 if (((__u32 *)arp)[i])
409 return 0;
410
411 return 1;
412}
413
414/* Figures out from what hook each rule can be called: returns 0 if
415 * there are loops. Puts hook bitmask in comefrom.
416 */
417static int mark_source_chains(struct arpt_table_info *newinfo, unsigned int valid_hooks)
418{
419 unsigned int hook;
420
421 /* No recursion; use packet counter to save back ptrs (reset
422 * to 0 as we leave), and comefrom to save source hook bitmask.
423 */
424 for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) {
425 unsigned int pos = newinfo->hook_entry[hook];
426 struct arpt_entry *e
427 = (struct arpt_entry *)(newinfo->entries + pos);
428
429 if (!(valid_hooks & (1 << hook)))
430 continue;
431
432 /* Set initial back pointer. */
433 e->counters.pcnt = pos;
434
435 for (;;) {
436 struct arpt_standard_target *t
437 = (void *)arpt_get_target(e);
438
439 if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) {
440 printk("arptables: loop hook %u pos %u %08X.\n",
441 hook, pos, e->comefrom);
442 return 0;
443 }
444 e->comefrom
445 |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS));
446
447 /* Unconditional return/END. */
448 if (e->target_offset == sizeof(struct arpt_entry)
449 && (strcmp(t->target.u.user.name,
450 ARPT_STANDARD_TARGET) == 0)
451 && t->verdict < 0
452 && unconditional(&e->arp)) {
453 unsigned int oldpos, size;
454
455 /* Return: backtrack through the last
456 * big jump.
457 */
458 do {
459 e->comefrom ^= (1<<NF_ARP_NUMHOOKS);
460 oldpos = pos;
461 pos = e->counters.pcnt;
462 e->counters.pcnt = 0;
463
464 /* We're at the start. */
465 if (pos == oldpos)
466 goto next;
467
468 e = (struct arpt_entry *)
469 (newinfo->entries + pos);
470 } while (oldpos == pos + e->next_offset);
471
472 /* Move along one */
473 size = e->next_offset;
474 e = (struct arpt_entry *)
475 (newinfo->entries + pos + size);
476 e->counters.pcnt = pos;
477 pos += size;
478 } else {
479 int newpos = t->verdict;
480
481 if (strcmp(t->target.u.user.name,
482 ARPT_STANDARD_TARGET) == 0
483 && newpos >= 0) {
484 /* This a jump; chase it. */
485 duprintf("Jump rule %u -> %u\n",
486 pos, newpos);
487 } else {
488 /* ... this is a fallthru */
489 newpos = pos + e->next_offset;
490 }
491 e = (struct arpt_entry *)
492 (newinfo->entries + newpos);
493 e->counters.pcnt = pos;
494 pos = newpos;
495 }
496 }
497 next:
498 duprintf("Finished chain %u\n", hook);
499 }
500 return 1;
501}
502
503static inline int standard_check(const struct arpt_entry_target *t,
504 unsigned int max_offset)
505{
506 struct arpt_standard_target *targ = (void *)t;
507
508 /* Check standard info. */
509 if (t->u.target_size
510 != ARPT_ALIGN(sizeof(struct arpt_standard_target))) {
511 duprintf("arpt_standard_check: target size %u != %Zu\n",
512 t->u.target_size,
513 ARPT_ALIGN(sizeof(struct arpt_standard_target)));
514 return 0;
515 }
516
517 if (targ->verdict >= 0
518 && targ->verdict > max_offset - sizeof(struct arpt_entry)) {
519 duprintf("arpt_standard_check: bad verdict (%i)\n",
520 targ->verdict);
521 return 0;
522 }
523
524 if (targ->verdict < -NF_MAX_VERDICT - 1) {
525 duprintf("arpt_standard_check: bad negative verdict (%i)\n",
526 targ->verdict);
527 return 0;
528 }
529 return 1;
530}
531
532static struct arpt_target arpt_standard_target;
533
534static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size,
535 unsigned int *i)
536{
537 struct arpt_entry_target *t;
538 struct arpt_target *target;
539 int ret;
540
541 if (!arp_checkentry(&e->arp)) {
542 duprintf("arp_tables: arp check failed %p %s.\n", e, name);
543 return -EINVAL;
544 }
545
546 t = arpt_get_target(e);
547 target = arpt_find_target_lock(t->u.user.name, &ret, &arpt_mutex);
548 if (!target) {
549 duprintf("check_entry: `%s' not found\n", t->u.user.name);
550 goto out;
551 }
552 if (!try_module_get((target->me))) {
553 ret = -ENOENT;
554 goto out_unlock;
555 }
556 t->u.kernel.target = target;
557 up(&arpt_mutex);
558
559 if (t->u.kernel.target == &arpt_standard_target) {
560 if (!standard_check(t, size)) {
561 ret = -EINVAL;
562 goto out;
563 }
564 } else if (t->u.kernel.target->checkentry
565 && !t->u.kernel.target->checkentry(name, e, t->data,
566 t->u.target_size
567 - sizeof(*t),
568 e->comefrom)) {
569 module_put(t->u.kernel.target->me);
570 duprintf("arp_tables: check failed for `%s'.\n",
571 t->u.kernel.target->name);
572 ret = -EINVAL;
573 goto out;
574 }
575
576 (*i)++;
577 return 0;
578
579out_unlock:
580 up(&arpt_mutex);
581out:
582 return ret;
583}
584
585static inline int check_entry_size_and_hooks(struct arpt_entry *e,
586 struct arpt_table_info *newinfo,
587 unsigned char *base,
588 unsigned char *limit,
589 const unsigned int *hook_entries,
590 const unsigned int *underflows,
591 unsigned int *i)
592{
593 unsigned int h;
594
595 if ((unsigned long)e % __alignof__(struct arpt_entry) != 0
596 || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) {
597 duprintf("Bad offset %p\n", e);
598 return -EINVAL;
599 }
600
601 if (e->next_offset
602 < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) {
603 duprintf("checking: element %p size %u\n",
604 e, e->next_offset);
605 return -EINVAL;
606 }
607
608 /* Check hooks & underflows */
609 for (h = 0; h < NF_ARP_NUMHOOKS; h++) {
610 if ((unsigned char *)e - base == hook_entries[h])
611 newinfo->hook_entry[h] = hook_entries[h];
612 if ((unsigned char *)e - base == underflows[h])
613 newinfo->underflow[h] = underflows[h];
614 }
615
616 /* FIXME: underflows must be unconditional, standard verdicts
617 < 0 (not ARPT_RETURN). --RR */
618
619 /* Clear counters and comefrom */
620 e->counters = ((struct arpt_counters) { 0, 0 });
621 e->comefrom = 0;
622
623 (*i)++;
624 return 0;
625}
626
627static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i)
628{
629 struct arpt_entry_target *t;
630
631 if (i && (*i)-- == 0)
632 return 1;
633
634 t = arpt_get_target(e);
635 if (t->u.kernel.target->destroy)
636 t->u.kernel.target->destroy(t->data,
637 t->u.target_size - sizeof(*t));
638 module_put(t->u.kernel.target->me);
639 return 0;
640}
641
642/* Checks and translates the user-supplied table segment (held in
643 * newinfo).
644 */
645static int translate_table(const char *name,
646 unsigned int valid_hooks,
647 struct arpt_table_info *newinfo,
648 unsigned int size,
649 unsigned int number,
650 const unsigned int *hook_entries,
651 const unsigned int *underflows)
652{
653 unsigned int i;
654 int ret;
655
656 newinfo->size = size;
657 newinfo->number = number;
658
659 /* Init all hooks to impossible value. */
660 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
661 newinfo->hook_entry[i] = 0xFFFFFFFF;
662 newinfo->underflow[i] = 0xFFFFFFFF;
663 }
664
665 duprintf("translate_table: size %u\n", newinfo->size);
666 i = 0;
667
668 /* Walk through entries, checking offsets. */
669 ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
670 check_entry_size_and_hooks,
671 newinfo,
672 newinfo->entries,
673 newinfo->entries + size,
674 hook_entries, underflows, &i);
675 duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret);
676 if (ret != 0)
677 return ret;
678
679 if (i != number) {
680 duprintf("translate_table: %u not %u entries\n",
681 i, number);
682 return -EINVAL;
683 }
684
685 /* Check hooks all assigned */
686 for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
687 /* Only hooks which are valid */
688 if (!(valid_hooks & (1 << i)))
689 continue;
690 if (newinfo->hook_entry[i] == 0xFFFFFFFF) {
691 duprintf("Invalid hook entry %u %u\n",
692 i, hook_entries[i]);
693 return -EINVAL;
694 }
695 if (newinfo->underflow[i] == 0xFFFFFFFF) {
696 duprintf("Invalid underflow %u %u\n",
697 i, underflows[i]);
698 return -EINVAL;
699 }
700 }
701
702 if (!mark_source_chains(newinfo, valid_hooks)) {
703 duprintf("Looping hook\n");
704 return -ELOOP;
705 }
706
707 /* Finally, each sanity check must pass */
708 i = 0;
709 ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
710 check_entry, name, size, &i);
711
712 if (ret != 0) {
713 ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size,
714 cleanup_entry, &i);
715 return ret;
716 }
717
718 /* And one copy for every other CPU */
c8923c6b
DM		 719 for_each_cpu(i) {
720 if (i == 0)
721 continue;
722 memcpy(newinfo->entries + SMP_ALIGN(newinfo->size) * i,
1da177e4
LT		 723 newinfo->entries,
724 SMP_ALIGN(newinfo->size));
725 }
726
727 return ret;
728}
729
730static struct arpt_table_info *replace_table(struct arpt_table *table,
731 unsigned int num_counters,
732 struct arpt_table_info *newinfo,
733 int *error)
734{
735 struct arpt_table_info *oldinfo;
736
737 /* Do the substitution. */
738 write_lock_bh(&table->lock);
739 /* Check inside lock: is the old number correct? */
740 if (num_counters != table->private->number) {
741 duprintf("num_counters != table->private->number (%u/%u)\n",
742 num_counters, table->private->number);
743 write_unlock_bh(&table->lock);
744 *error = -EAGAIN;
745 return NULL;
746 }
747 oldinfo = table->private;
748 table->private = newinfo;
749 newinfo->initial_entries = oldinfo->initial_entries;
750 write_unlock_bh(&table->lock);
751
752 return oldinfo;
753}
754
755/* Gets counters. */
756static inline int add_entry_to_counter(const struct arpt_entry *e,
757 struct arpt_counters total[],
758 unsigned int *i)
759{
760 ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt);
761
762 (*i)++;
763 return 0;
764}
765
766static void get_counters(const struct arpt_table_info *t,
767 struct arpt_counters counters[])
768{
769 unsigned int cpu;
770 unsigned int i;
771
c8923c6b 772 for_each_cpu(cpu) {
1da177e4
LT		 773 i = 0;
774 ARPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu),
775 t->size,
776 add_entry_to_counter,
777 counters,
778 &i);
779 }
780}
781
782static int copy_entries_to_user(unsigned int total_size,
783 struct arpt_table *table,
784 void __user *userptr)
785{
786 unsigned int off, num, countersize;
787 struct arpt_entry *e;
788 struct arpt_counters *counters;
789 int ret = 0;
790
791 /* We need atomic snapshot of counters: rest doesn't change
792 * (other than comefrom, which userspace doesn't care
793 * about).
794 */
795 countersize = sizeof(struct arpt_counters) * table->private->number;
796 counters = vmalloc(countersize);
797
798 if (counters == NULL)
799 return -ENOMEM;
800
801 /* First, sum counters... */
802 memset(counters, 0, countersize);
803 write_lock_bh(&table->lock);
804 get_counters(table->private, counters);
805 write_unlock_bh(&table->lock);
806
807 /* ... then copy entire thing from CPU 0... */
808 if (copy_to_user(userptr, table->private->entries, total_size) != 0) {
809 ret = -EFAULT;
810 goto free_counters;
811 }
812
813 /* FIXME: use iterator macros --RR */
814 /* ... then go back and fix counters and names */
815 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){
816 struct arpt_entry_target *t;
817
818 e = (struct arpt_entry *)(table->private->entries + off);
819 if (copy_to_user(userptr + off
820 + offsetof(struct arpt_entry, counters),
821 &counters[num],
822 sizeof(counters[num])) != 0) {
823 ret = -EFAULT;
824 goto free_counters;
825 }
826
827 t = arpt_get_target(e);
828 if (copy_to_user(userptr + off + e->target_offset
829 + offsetof(struct arpt_entry_target,
830 u.user.name),
831 t->u.kernel.target->name,
832 strlen(t->u.kernel.target->name)+1) != 0) {
833 ret = -EFAULT;
834 goto free_counters;
835 }
836 }
837
838 free_counters:
839 vfree(counters);
840 return ret;
841}
842
843static int get_entries(const struct arpt_get_entries *entries,
844 struct arpt_get_entries __user *uptr)
845{
846 int ret;
847 struct arpt_table *t;
848
849 t = arpt_find_table_lock(entries->name, &ret, &arpt_mutex);
850 if (t) {
851 duprintf("t->private->number = %u\n",
852 t->private->number);
853 if (entries->size == t->private->size)
854 ret = copy_entries_to_user(t->private->size,
855 t, uptr->entrytable);
856 else {
857 duprintf("get_entries: I've got %u not %u!\n",
858 t->private->size,
859 entries->size);
860 ret = -EINVAL;
861 }
862 up(&arpt_mutex);
863 } else
864 duprintf("get_entries: Can't find %s!\n",
865 entries->name);
866
867 return ret;
868}
869
870static int do_replace(void __user *user, unsigned int len)
871{
872 int ret;
873 struct arpt_replace tmp;
874 struct arpt_table *t;
875 struct arpt_table_info *newinfo, *oldinfo;
876 struct arpt_counters *counters;
877
878 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
879 return -EFAULT;
880
881 /* Hack: Causes ipchains to give correct error msg --RR */
882 if (len != sizeof(tmp) + tmp.size)
883 return -ENOPROTOOPT;
884
885 /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */
886 if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages)
887 return -ENOMEM;
888
889 newinfo = vmalloc(sizeof(struct arpt_table_info)
c8923c6b
DM		 890 + SMP_ALIGN(tmp.size) *
891 (highest_possible_processor_id()+1));
1da177e4
LT		 892 if (!newinfo)
893 return -ENOMEM;
894
895 if (copy_from_user(newinfo->entries, user + sizeof(tmp),
896 tmp.size) != 0) {
897 ret = -EFAULT;
898 goto free_newinfo;
899 }
900
901 counters = vmalloc(tmp.num_counters * sizeof(struct arpt_counters));
902 if (!counters) {
903 ret = -ENOMEM;
904 goto free_newinfo;
905 }
906 memset(counters, 0, tmp.num_counters * sizeof(struct arpt_counters));
907
908 ret = translate_table(tmp.name, tmp.valid_hooks,
909 newinfo, tmp.size, tmp.num_entries,
910 tmp.hook_entry, tmp.underflow);
911 if (ret != 0)
912 goto free_newinfo_counters;
913
914 duprintf("arp_tables: Translated table\n");
915
916 t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
917 if (!t)
918 goto free_newinfo_counters_untrans;
919
920 /* You lied! */
921 if (tmp.valid_hooks != t->valid_hooks) {
922 duprintf("Valid hook crap: %08X vs %08X\n",
923 tmp.valid_hooks, t->valid_hooks);
924 ret = -EINVAL;
925 goto free_newinfo_counters_untrans_unlock;
926 }
927
928 /* Get a reference in advance, we're not allowed fail later */
929 if (!try_module_get(t->me)) {
930 ret = -EBUSY;
931 goto free_newinfo_counters_untrans_unlock;
932 }
933
934 oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret);
935 if (!oldinfo)
936 goto put_module;
937
938 /* Update module usage count based on number of rules */
939 duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n",
940 oldinfo->number, oldinfo->initial_entries, newinfo->number);
941 if ((oldinfo->number > oldinfo->initial_entries) ||
942 (newinfo->number <= oldinfo->initial_entries))
943 module_put(t->me);
944 if ((oldinfo->number > oldinfo->initial_entries) &&
945 (newinfo->number <= oldinfo->initial_entries))
946 module_put(t->me);
947
948 /* Get the old counters. */
949 get_counters(oldinfo, counters);
950 /* Decrease module usage counts and free resource */
951 ARPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL);
952 vfree(oldinfo);
953 if (copy_to_user(tmp.counters, counters,
954 sizeof(struct arpt_counters) * tmp.num_counters) != 0)
955 ret = -EFAULT;
956 vfree(counters);
957 up(&arpt_mutex);
958 return ret;
959
960 put_module:
961 module_put(t->me);
962 free_newinfo_counters_untrans_unlock:
963 up(&arpt_mutex);
964 free_newinfo_counters_untrans:
965 ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry, NULL);
966 free_newinfo_counters:
967 vfree(counters);
968 free_newinfo:
969 vfree(newinfo);
970 return ret;
971}
972
973/* We're lazy, and add to the first CPU; overflow works its fey magic
974 * and everything is OK.
975 */
976static inline int add_counter_to_entry(struct arpt_entry *e,
977 const struct arpt_counters addme[],
978 unsigned int *i)
979{
980
981 ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt);
982
983 (*i)++;
984 return 0;
985}
986
987static int do_add_counters(void __user *user, unsigned int len)
988{
989 unsigned int i;
990 struct arpt_counters_info tmp, *paddc;
991 struct arpt_table *t;
992 int ret;
993
994 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0)
995 return -EFAULT;
996
997 if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct arpt_counters))
998 return -EINVAL;
999
1000 paddc = vmalloc(len);
1001 if (!paddc)
1002 return -ENOMEM;
1003
1004 if (copy_from_user(paddc, user, len) != 0) {
1005 ret = -EFAULT;
1006 goto free;
1007 }
1008
1009 t = arpt_find_table_lock(tmp.name, &ret, &arpt_mutex);
1010 if (!t)
1011 goto free;
1012
1013 write_lock_bh(&t->lock);
1014 if (t->private->number != paddc->num_counters) {
1015 ret = -EINVAL;
1016 goto unlock_up_free;
1017 }
1018
1019 i = 0;
1020 ARPT_ENTRY_ITERATE(t->private->entries,
1021 t->private->size,
1022 add_counter_to_entry,
1023 paddc->counters,
1024 &i);
1025 unlock_up_free:
1026 write_unlock_bh(&t->lock);
1027 up(&arpt_mutex);
1028 free:
1029 vfree(paddc);
1030
1031 return ret;
1032}
1033
1034static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len)
1035{
1036 int ret;
1037
1038 if (!capable(CAP_NET_ADMIN))
1039 return -EPERM;
1040
1041 switch (cmd) {
1042 case ARPT_SO_SET_REPLACE:
1043 ret = do_replace(user, len);
1044 break;
1045
1046 case ARPT_SO_SET_ADD_COUNTERS:
1047 ret = do_add_counters(user, len);
1048 break;
1049
1050 default:
1051 duprintf("do_arpt_set_ctl: unknown request %i\n", cmd);
1052 ret = -EINVAL;
1053 }
1054
1055 return ret;
1056}
1057
1058static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
1059{
1060 int ret;
1061
1062 if (!capable(CAP_NET_ADMIN))
1063 return -EPERM;
1064
1065 switch (cmd) {
1066 case ARPT_SO_GET_INFO: {
1067 char name[ARPT_TABLE_MAXNAMELEN];
1068 struct arpt_table *t;
1069
1070 if (*len != sizeof(struct arpt_getinfo)) {
1071 duprintf("length %u != %Zu\n", *len,
1072 sizeof(struct arpt_getinfo));
1073 ret = -EINVAL;
1074 break;
1075 }
1076
1077 if (copy_from_user(name, user, sizeof(name)) != 0) {
1078 ret = -EFAULT;
1079 break;
1080 }
1081 name[ARPT_TABLE_MAXNAMELEN-1] = '\0';
1082 t = arpt_find_table_lock(name, &ret, &arpt_mutex);
1083 if (t) {
1084 struct arpt_getinfo info;
1085
1086 info.valid_hooks = t->valid_hooks;
1087 memcpy(info.hook_entry, t->private->hook_entry,
1088 sizeof(info.hook_entry));
1089 memcpy(info.underflow, t->private->underflow,
1090 sizeof(info.underflow));
1091 info.num_entries = t->private->number;
1092 info.size = t->private->size;
1093 strcpy(info.name, name);
1094
1095 if (copy_to_user(user, &info, *len) != 0)
1096 ret = -EFAULT;
1097 else
1098 ret = 0;
1099
1100 up(&arpt_mutex);
1101 }
1102 }
1103 break;
1104
1105 case ARPT_SO_GET_ENTRIES: {
1106 struct arpt_get_entries get;
1107
1108 if (*len < sizeof(get)) {
1109 duprintf("get_entries: %u < %Zu\n", *len, sizeof(get));
1110 ret = -EINVAL;
1111 } else if (copy_from_user(&get, user, sizeof(get)) != 0) {
1112 ret = -EFAULT;
1113 } else if (*len != sizeof(struct arpt_get_entries) + get.size) {
1114 duprintf("get_entries: %u != %Zu\n", *len,
1115 sizeof(struct arpt_get_entries) + get.size);
1116 ret = -EINVAL;
1117 } else
1118 ret = get_entries(&get, user);
1119 break;
1120 }
1121
1122 default:
1123 duprintf("do_arpt_get_ctl: unknown request %i\n", cmd);
1124 ret = -EINVAL;
1125 }
1126
1127 return ret;
1128}
1129
1130/* Registration hooks for targets. */
1131int arpt_register_target(struct arpt_target *target)
1132{
1133 int ret;
1134
1135 ret = down_interruptible(&arpt_mutex);
1136 if (ret != 0)
1137 return ret;
1138
1139 if (!list_named_insert(&arpt_target, target)) {
1140 duprintf("arpt_register_target: `%s' already in list!\n",
1141 target->name);
1142 ret = -EINVAL;
1143 }
1144 up(&arpt_mutex);
1145 return ret;
1146}
1147
1148void arpt_unregister_target(struct arpt_target *target)
1149{
1150 down(&arpt_mutex);
1151 LIST_DELETE(&arpt_target, target);
1152 up(&arpt_mutex);
1153}
1154
1155int arpt_register_table(struct arpt_table *table,
1156 const struct arpt_replace *repl)
1157{
1158 int ret;
1159 struct arpt_table_info *newinfo;
1160 static struct arpt_table_info bootstrap
1161 = { 0, 0, 0, { 0 }, { 0 }, { } };
1162
1163 newinfo = vmalloc(sizeof(struct arpt_table_info)
c8923c6b
DM		 1164 + SMP_ALIGN(repl->size) *
1165 (highest_possible_processor_id()+1));
1da177e4
LT		 1166 if (!newinfo) {
1167 ret = -ENOMEM;
1168 return ret;
1169 }
1170 memcpy(newinfo->entries, repl->entries, repl->size);
1171
1172 ret = translate_table(table->name, table->valid_hooks,
1173 newinfo, repl->size,
1174 repl->num_entries,
1175 repl->hook_entry,
1176 repl->underflow);
1177 duprintf("arpt_register_table: translate table gives %d\n", ret);
1178 if (ret != 0) {
1179 vfree(newinfo);
1180 return ret;
1181 }
1182
1183 ret = down_interruptible(&arpt_mutex);
1184 if (ret != 0) {
1185 vfree(newinfo);
1186 return ret;
1187 }
1188
1189 /* Don't autoload: we'd eat our tail... */
1190 if (list_named_find(&arpt_tables, table->name)) {
1191 ret = -EEXIST;
1192 goto free_unlock;
1193 }
1194
1195 /* Simplifies replace_table code. */
1196 table->private = &bootstrap;
1197 if (!replace_table(table, 0, newinfo, &ret))
1198 goto free_unlock;
1199
1200 duprintf("table->private->number = %u\n",
1201 table->private->number);
1202
1203 /* save number of initial entries */
1204 table->private->initial_entries = table->private->number;
1205
1206 rwlock_init(&table->lock);
1207 list_prepend(&arpt_tables, table);
1208
1209 unlock:
1210 up(&arpt_mutex);
1211 return ret;
1212
1213 free_unlock:
1214 vfree(newinfo);
1215 goto unlock;
1216}
1217
1218void arpt_unregister_table(struct arpt_table *table)
1219{
1220 down(&arpt_mutex);
1221 LIST_DELETE(&arpt_tables, table);
1222 up(&arpt_mutex);
1223
1224 /* Decrease module usage counts and free resources */
1225 ARPT_ENTRY_ITERATE(table->private->entries, table->private->size,
1226 cleanup_entry, NULL);
1227 vfree(table->private);
1228}
1229
1230/* The built-in targets: standard (NULL) and error. */
1231static struct arpt_target arpt_standard_target = {
1232 .name = ARPT_STANDARD_TARGET,
1233};
1234
1235static struct arpt_target arpt_error_target = {
1236 .name = ARPT_ERROR_TARGET,
1237 .target = arpt_error,
1238};
1239
1240static struct nf_sockopt_ops arpt_sockopts = {
1241 .pf = PF_INET,
1242 .set_optmin = ARPT_BASE_CTL,
1243 .set_optmax = ARPT_SO_SET_MAX+1,
1244 .set = do_arpt_set_ctl,
1245 .get_optmin = ARPT_BASE_CTL,
1246 .get_optmax = ARPT_SO_GET_MAX+1,
1247 .get = do_arpt_get_ctl,
1248};
1249
1250#ifdef CONFIG_PROC_FS
1251static inline int print_name(const struct arpt_table *t,
1252 off_t start_offset, char *buffer, int length,
1253 off_t *pos, unsigned int *count)
1254{
1255 if ((*count)++ >= start_offset) {
1256 unsigned int namelen;
1257
1258 namelen = sprintf(buffer + *pos, "%s\n", t->name);
1259 if (*pos + namelen > length) {
1260 /* Stop iterating */
1261 return 1;
1262 }
1263 *pos += namelen;
1264 }
1265 return 0;
1266}
1267
1268static int arpt_get_tables(char *buffer, char **start, off_t offset, int length)
1269{
1270 off_t pos = 0;
1271 unsigned int count = 0;
1272
1273 if (down_interruptible(&arpt_mutex) != 0)
1274 return 0;
1275
1276 LIST_FIND(&arpt_tables, print_name, struct arpt_table *,
1277 offset, buffer, length, &pos, &count);
1278
1279 up(&arpt_mutex);
1280
1281 /* `start' hack - see fs/proc/generic.c line ~105 */
1282 *start=(char *)((unsigned long)count-offset);
1283 return pos;
1284}
1285#endif /*CONFIG_PROC_FS*/
1286
1287static int __init init(void)
1288{
1289 int ret;
1290
1291 /* Noone else will be downing sem now, so we won't sleep */
1292 down(&arpt_mutex);
1293 list_append(&arpt_target, &arpt_standard_target);
1294 list_append(&arpt_target, &arpt_error_target);
1295 up(&arpt_mutex);
1296
1297 /* Register setsockopt */
1298 ret = nf_register_sockopt(&arpt_sockopts);
1299 if (ret < 0) {
1300 duprintf("Unable to register sockopts.\n");
1301 return ret;
1302 }
1303
1304#ifdef CONFIG_PROC_FS
1305 {
1306 struct proc_dir_entry *proc;
1307
1308 proc = proc_net_create("arp_tables_names", 0, arpt_get_tables);
1309 if (!proc) {
1310 nf_unregister_sockopt(&arpt_sockopts);
1311 return -ENOMEM;
1312 }
1313 proc->owner = THIS_MODULE;
1314 }
1315#endif
1316
1317 printk("arp_tables: (C) 2002 David S. Miller\n");
1318 return 0;
1319}
1320
1321static void __exit fini(void)
1322{
1323 nf_unregister_sockopt(&arpt_sockopts);
1324#ifdef CONFIG_PROC_FS
1325 proc_net_remove("arp_tables_names");
1326#endif
1327}
1328
1329EXPORT_SYMBOL(arpt_register_table);
1330EXPORT_SYMBOL(arpt_unregister_table);
1331EXPORT_SYMBOL(arpt_do_table);
1332EXPORT_SYMBOL(arpt_register_target);
1333EXPORT_SYMBOL(arpt_unregister_target);
1334
1335module_init(init);
1336module_exit(fini);
kernel source for telekom puls (alcatel/mediatek)