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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 | ||
28 | MODULE_LICENSE("GPL"); | |
29 | MODULE_AUTHOR("David S. Miller <davem@redhat.com>"); | |
30 | MODULE_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) \ | |
49 | do { \ | |
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 | ||
59 | static 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 | ||
65 | struct 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 | ||
74 | static LIST_HEAD(arpt_target); | |
75 | static 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 | ||
84 | static 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. */ | |
100 | static 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 | ||
213 | static 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 | ||
229 | static 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 | ||
242 | static inline struct arpt_entry *get_entry(void *base, unsigned int offset) | |
243 | { | |
244 | return (struct arpt_entry *)(base + offset); | |
245 | } | |
246 | ||
247 | unsigned 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 | ||
6b7d31fc HW |
350 | /* |
351 | * These are weird, but module loading must not be done with mutex | |
352 | * held (since they will register), and we have to have a single | |
353 | * function to use try_then_request_module(). | |
354 | */ | |
355 | ||
356 | /* Find table by name, grabs mutex & ref. Returns ERR_PTR() on error. */ | |
357 | static inline struct arpt_table *find_table_lock(const char *name) | |
1da177e4 | 358 | { |
6b7d31fc | 359 | struct arpt_table *t; |
1da177e4 | 360 | |
6b7d31fc HW |
361 | if (down_interruptible(&arpt_mutex) != 0) |
362 | return ERR_PTR(-EINTR); | |
1da177e4 | 363 | |
6b7d31fc HW |
364 | list_for_each_entry(t, &arpt_tables, list) |
365 | if (strcmp(t->name, name) == 0 && try_module_get(t->me)) | |
366 | return t; | |
367 | up(&arpt_mutex); | |
368 | return NULL; | |
1da177e4 LT |
369 | } |
370 | ||
1da177e4 | 371 | |
6b7d31fc HW |
372 | /* Find target, grabs ref. Returns ERR_PTR() on error. */ |
373 | static inline struct arpt_target *find_target(const char *name, u8 revision) | |
374 | { | |
375 | struct arpt_target *t; | |
376 | int err = 0; | |
377 | ||
378 | if (down_interruptible(&arpt_mutex) != 0) | |
379 | return ERR_PTR(-EINTR); | |
380 | ||
381 | list_for_each_entry(t, &arpt_target, list) { | |
382 | if (strcmp(t->name, name) == 0) { | |
383 | if (t->revision == revision) { | |
384 | if (try_module_get(t->me)) { | |
385 | up(&arpt_mutex); | |
386 | return t; | |
387 | } | |
388 | } else | |
389 | err = -EPROTOTYPE; /* Found something. */ | |
390 | } | |
1da177e4 | 391 | } |
6b7d31fc HW |
392 | up(&arpt_mutex); |
393 | return ERR_PTR(err); | |
394 | } | |
1da177e4 | 395 | |
6b7d31fc HW |
396 | struct arpt_target *arpt_find_target(const char *name, u8 revision) |
397 | { | |
398 | struct arpt_target *target; | |
399 | ||
400 | target = try_then_request_module(find_target(name, revision), | |
401 | "arpt_%s", name); | |
402 | if (IS_ERR(target) || !target) | |
403 | return NULL; | |
404 | return target; | |
1da177e4 | 405 | } |
1da177e4 | 406 | |
6b7d31fc | 407 | static int target_revfn(const char *name, u8 revision, int *bestp) |
1da177e4 | 408 | { |
6b7d31fc HW |
409 | struct arpt_target *t; |
410 | int have_rev = 0; | |
411 | ||
412 | list_for_each_entry(t, &arpt_target, list) { | |
413 | if (strcmp(t->name, name) == 0) { | |
414 | if (t->revision > *bestp) | |
415 | *bestp = t->revision; | |
416 | if (t->revision == revision) | |
417 | have_rev =1; | |
418 | } | |
419 | } | |
420 | return have_rev; | |
1da177e4 LT |
421 | } |
422 | ||
6b7d31fc HW |
423 | /* Returns true or false (if no such extension at all) */ |
424 | static inline int find_revision(const char *name, u8 revision, | |
425 | int (*revfn)(const char *, u8, int *), | |
426 | int *err) | |
1da177e4 | 427 | { |
6b7d31fc HW |
428 | int have_rev, best = -1; |
429 | ||
430 | if (down_interruptible(&arpt_mutex) != 0) { | |
431 | *err = -EINTR; | |
432 | return 1; | |
433 | } | |
434 | have_rev = revfn(name, revision, &best); | |
435 | up(&arpt_mutex); | |
436 | ||
437 | /* Nothing at all? Return 0 to try loading module. */ | |
438 | if (best == -1) { | |
439 | *err = -ENOENT; | |
440 | return 0; | |
441 | } | |
442 | ||
443 | *err = best; | |
444 | if (!have_rev) | |
445 | *err = -EPROTONOSUPPORT; | |
446 | return 1; | |
1da177e4 LT |
447 | } |
448 | ||
6b7d31fc | 449 | |
1da177e4 LT |
450 | /* All zeroes == unconditional rule. */ |
451 | static inline int unconditional(const struct arpt_arp *arp) | |
452 | { | |
453 | unsigned int i; | |
454 | ||
455 | for (i = 0; i < sizeof(*arp)/sizeof(__u32); i++) | |
456 | if (((__u32 *)arp)[i]) | |
457 | return 0; | |
458 | ||
459 | return 1; | |
460 | } | |
461 | ||
462 | /* Figures out from what hook each rule can be called: returns 0 if | |
463 | * there are loops. Puts hook bitmask in comefrom. | |
464 | */ | |
465 | static int mark_source_chains(struct arpt_table_info *newinfo, unsigned int valid_hooks) | |
466 | { | |
467 | unsigned int hook; | |
468 | ||
469 | /* No recursion; use packet counter to save back ptrs (reset | |
470 | * to 0 as we leave), and comefrom to save source hook bitmask. | |
471 | */ | |
472 | for (hook = 0; hook < NF_ARP_NUMHOOKS; hook++) { | |
473 | unsigned int pos = newinfo->hook_entry[hook]; | |
474 | struct arpt_entry *e | |
475 | = (struct arpt_entry *)(newinfo->entries + pos); | |
476 | ||
477 | if (!(valid_hooks & (1 << hook))) | |
478 | continue; | |
479 | ||
480 | /* Set initial back pointer. */ | |
481 | e->counters.pcnt = pos; | |
482 | ||
483 | for (;;) { | |
484 | struct arpt_standard_target *t | |
485 | = (void *)arpt_get_target(e); | |
486 | ||
487 | if (e->comefrom & (1 << NF_ARP_NUMHOOKS)) { | |
488 | printk("arptables: loop hook %u pos %u %08X.\n", | |
489 | hook, pos, e->comefrom); | |
490 | return 0; | |
491 | } | |
492 | e->comefrom | |
493 | |= ((1 << hook) | (1 << NF_ARP_NUMHOOKS)); | |
494 | ||
495 | /* Unconditional return/END. */ | |
496 | if (e->target_offset == sizeof(struct arpt_entry) | |
497 | && (strcmp(t->target.u.user.name, | |
498 | ARPT_STANDARD_TARGET) == 0) | |
499 | && t->verdict < 0 | |
500 | && unconditional(&e->arp)) { | |
501 | unsigned int oldpos, size; | |
502 | ||
503 | /* Return: backtrack through the last | |
504 | * big jump. | |
505 | */ | |
506 | do { | |
507 | e->comefrom ^= (1<<NF_ARP_NUMHOOKS); | |
508 | oldpos = pos; | |
509 | pos = e->counters.pcnt; | |
510 | e->counters.pcnt = 0; | |
511 | ||
512 | /* We're at the start. */ | |
513 | if (pos == oldpos) | |
514 | goto next; | |
515 | ||
516 | e = (struct arpt_entry *) | |
517 | (newinfo->entries + pos); | |
518 | } while (oldpos == pos + e->next_offset); | |
519 | ||
520 | /* Move along one */ | |
521 | size = e->next_offset; | |
522 | e = (struct arpt_entry *) | |
523 | (newinfo->entries + pos + size); | |
524 | e->counters.pcnt = pos; | |
525 | pos += size; | |
526 | } else { | |
527 | int newpos = t->verdict; | |
528 | ||
529 | if (strcmp(t->target.u.user.name, | |
530 | ARPT_STANDARD_TARGET) == 0 | |
531 | && newpos >= 0) { | |
532 | /* This a jump; chase it. */ | |
533 | duprintf("Jump rule %u -> %u\n", | |
534 | pos, newpos); | |
535 | } else { | |
536 | /* ... this is a fallthru */ | |
537 | newpos = pos + e->next_offset; | |
538 | } | |
539 | e = (struct arpt_entry *) | |
540 | (newinfo->entries + newpos); | |
541 | e->counters.pcnt = pos; | |
542 | pos = newpos; | |
543 | } | |
544 | } | |
545 | next: | |
546 | duprintf("Finished chain %u\n", hook); | |
547 | } | |
548 | return 1; | |
549 | } | |
550 | ||
551 | static inline int standard_check(const struct arpt_entry_target *t, | |
552 | unsigned int max_offset) | |
553 | { | |
554 | struct arpt_standard_target *targ = (void *)t; | |
555 | ||
556 | /* Check standard info. */ | |
557 | if (t->u.target_size | |
558 | != ARPT_ALIGN(sizeof(struct arpt_standard_target))) { | |
559 | duprintf("arpt_standard_check: target size %u != %Zu\n", | |
560 | t->u.target_size, | |
561 | ARPT_ALIGN(sizeof(struct arpt_standard_target))); | |
562 | return 0; | |
563 | } | |
564 | ||
565 | if (targ->verdict >= 0 | |
566 | && targ->verdict > max_offset - sizeof(struct arpt_entry)) { | |
567 | duprintf("arpt_standard_check: bad verdict (%i)\n", | |
568 | targ->verdict); | |
569 | return 0; | |
570 | } | |
571 | ||
572 | if (targ->verdict < -NF_MAX_VERDICT - 1) { | |
573 | duprintf("arpt_standard_check: bad negative verdict (%i)\n", | |
574 | targ->verdict); | |
575 | return 0; | |
576 | } | |
577 | return 1; | |
578 | } | |
579 | ||
580 | static struct arpt_target arpt_standard_target; | |
581 | ||
582 | static inline int check_entry(struct arpt_entry *e, const char *name, unsigned int size, | |
583 | unsigned int *i) | |
584 | { | |
585 | struct arpt_entry_target *t; | |
586 | struct arpt_target *target; | |
587 | int ret; | |
588 | ||
589 | if (!arp_checkentry(&e->arp)) { | |
590 | duprintf("arp_tables: arp check failed %p %s.\n", e, name); | |
591 | return -EINVAL; | |
592 | } | |
593 | ||
594 | t = arpt_get_target(e); | |
6b7d31fc HW |
595 | target = try_then_request_module(find_target(t->u.user.name, |
596 | t->u.user.revision), | |
597 | "arpt_%s", t->u.user.name); | |
598 | if (IS_ERR(target) || !target) { | |
1da177e4 | 599 | duprintf("check_entry: `%s' not found\n", t->u.user.name); |
6b7d31fc | 600 | ret = target ? PTR_ERR(target) : -ENOENT; |
1da177e4 LT |
601 | goto out; |
602 | } | |
1da177e4 | 603 | t->u.kernel.target = target; |
1da177e4 LT |
604 | |
605 | if (t->u.kernel.target == &arpt_standard_target) { | |
606 | if (!standard_check(t, size)) { | |
607 | ret = -EINVAL; | |
608 | goto out; | |
609 | } | |
610 | } else if (t->u.kernel.target->checkentry | |
611 | && !t->u.kernel.target->checkentry(name, e, t->data, | |
612 | t->u.target_size | |
613 | - sizeof(*t), | |
614 | e->comefrom)) { | |
615 | module_put(t->u.kernel.target->me); | |
616 | duprintf("arp_tables: check failed for `%s'.\n", | |
617 | t->u.kernel.target->name); | |
618 | ret = -EINVAL; | |
619 | goto out; | |
620 | } | |
621 | ||
622 | (*i)++; | |
623 | return 0; | |
624 | ||
1da177e4 LT |
625 | out: |
626 | return ret; | |
627 | } | |
628 | ||
629 | static inline int check_entry_size_and_hooks(struct arpt_entry *e, | |
630 | struct arpt_table_info *newinfo, | |
631 | unsigned char *base, | |
632 | unsigned char *limit, | |
633 | const unsigned int *hook_entries, | |
634 | const unsigned int *underflows, | |
635 | unsigned int *i) | |
636 | { | |
637 | unsigned int h; | |
638 | ||
639 | if ((unsigned long)e % __alignof__(struct arpt_entry) != 0 | |
640 | || (unsigned char *)e + sizeof(struct arpt_entry) >= limit) { | |
641 | duprintf("Bad offset %p\n", e); | |
642 | return -EINVAL; | |
643 | } | |
644 | ||
645 | if (e->next_offset | |
646 | < sizeof(struct arpt_entry) + sizeof(struct arpt_entry_target)) { | |
647 | duprintf("checking: element %p size %u\n", | |
648 | e, e->next_offset); | |
649 | return -EINVAL; | |
650 | } | |
651 | ||
652 | /* Check hooks & underflows */ | |
653 | for (h = 0; h < NF_ARP_NUMHOOKS; h++) { | |
654 | if ((unsigned char *)e - base == hook_entries[h]) | |
655 | newinfo->hook_entry[h] = hook_entries[h]; | |
656 | if ((unsigned char *)e - base == underflows[h]) | |
657 | newinfo->underflow[h] = underflows[h]; | |
658 | } | |
659 | ||
660 | /* FIXME: underflows must be unconditional, standard verdicts | |
661 | < 0 (not ARPT_RETURN). --RR */ | |
662 | ||
663 | /* Clear counters and comefrom */ | |
664 | e->counters = ((struct arpt_counters) { 0, 0 }); | |
665 | e->comefrom = 0; | |
666 | ||
667 | (*i)++; | |
668 | return 0; | |
669 | } | |
670 | ||
671 | static inline int cleanup_entry(struct arpt_entry *e, unsigned int *i) | |
672 | { | |
673 | struct arpt_entry_target *t; | |
674 | ||
675 | if (i && (*i)-- == 0) | |
676 | return 1; | |
677 | ||
678 | t = arpt_get_target(e); | |
679 | if (t->u.kernel.target->destroy) | |
680 | t->u.kernel.target->destroy(t->data, | |
681 | t->u.target_size - sizeof(*t)); | |
682 | module_put(t->u.kernel.target->me); | |
683 | return 0; | |
684 | } | |
685 | ||
686 | /* Checks and translates the user-supplied table segment (held in | |
687 | * newinfo). | |
688 | */ | |
689 | static int translate_table(const char *name, | |
690 | unsigned int valid_hooks, | |
691 | struct arpt_table_info *newinfo, | |
692 | unsigned int size, | |
693 | unsigned int number, | |
694 | const unsigned int *hook_entries, | |
695 | const unsigned int *underflows) | |
696 | { | |
697 | unsigned int i; | |
698 | int ret; | |
699 | ||
700 | newinfo->size = size; | |
701 | newinfo->number = number; | |
702 | ||
703 | /* Init all hooks to impossible value. */ | |
704 | for (i = 0; i < NF_ARP_NUMHOOKS; i++) { | |
705 | newinfo->hook_entry[i] = 0xFFFFFFFF; | |
706 | newinfo->underflow[i] = 0xFFFFFFFF; | |
707 | } | |
708 | ||
709 | duprintf("translate_table: size %u\n", newinfo->size); | |
710 | i = 0; | |
711 | ||
712 | /* Walk through entries, checking offsets. */ | |
713 | ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, | |
714 | check_entry_size_and_hooks, | |
715 | newinfo, | |
716 | newinfo->entries, | |
717 | newinfo->entries + size, | |
718 | hook_entries, underflows, &i); | |
719 | duprintf("translate_table: ARPT_ENTRY_ITERATE gives %d\n", ret); | |
720 | if (ret != 0) | |
721 | return ret; | |
722 | ||
723 | if (i != number) { | |
724 | duprintf("translate_table: %u not %u entries\n", | |
725 | i, number); | |
726 | return -EINVAL; | |
727 | } | |
728 | ||
729 | /* Check hooks all assigned */ | |
730 | for (i = 0; i < NF_ARP_NUMHOOKS; i++) { | |
731 | /* Only hooks which are valid */ | |
732 | if (!(valid_hooks & (1 << i))) | |
733 | continue; | |
734 | if (newinfo->hook_entry[i] == 0xFFFFFFFF) { | |
735 | duprintf("Invalid hook entry %u %u\n", | |
736 | i, hook_entries[i]); | |
737 | return -EINVAL; | |
738 | } | |
739 | if (newinfo->underflow[i] == 0xFFFFFFFF) { | |
740 | duprintf("Invalid underflow %u %u\n", | |
741 | i, underflows[i]); | |
742 | return -EINVAL; | |
743 | } | |
744 | } | |
745 | ||
746 | if (!mark_source_chains(newinfo, valid_hooks)) { | |
747 | duprintf("Looping hook\n"); | |
748 | return -ELOOP; | |
749 | } | |
750 | ||
751 | /* Finally, each sanity check must pass */ | |
752 | i = 0; | |
753 | ret = ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, | |
754 | check_entry, name, size, &i); | |
755 | ||
756 | if (ret != 0) { | |
757 | ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, | |
758 | cleanup_entry, &i); | |
759 | return ret; | |
760 | } | |
761 | ||
762 | /* And one copy for every other CPU */ | |
c8923c6b DM |
763 | for_each_cpu(i) { |
764 | if (i == 0) | |
765 | continue; | |
766 | memcpy(newinfo->entries + SMP_ALIGN(newinfo->size) * i, | |
1da177e4 LT |
767 | newinfo->entries, |
768 | SMP_ALIGN(newinfo->size)); | |
769 | } | |
770 | ||
771 | return ret; | |
772 | } | |
773 | ||
774 | static struct arpt_table_info *replace_table(struct arpt_table *table, | |
775 | unsigned int num_counters, | |
776 | struct arpt_table_info *newinfo, | |
777 | int *error) | |
778 | { | |
779 | struct arpt_table_info *oldinfo; | |
780 | ||
781 | /* Do the substitution. */ | |
782 | write_lock_bh(&table->lock); | |
783 | /* Check inside lock: is the old number correct? */ | |
784 | if (num_counters != table->private->number) { | |
785 | duprintf("num_counters != table->private->number (%u/%u)\n", | |
786 | num_counters, table->private->number); | |
787 | write_unlock_bh(&table->lock); | |
788 | *error = -EAGAIN; | |
789 | return NULL; | |
790 | } | |
791 | oldinfo = table->private; | |
792 | table->private = newinfo; | |
793 | newinfo->initial_entries = oldinfo->initial_entries; | |
794 | write_unlock_bh(&table->lock); | |
795 | ||
796 | return oldinfo; | |
797 | } | |
798 | ||
799 | /* Gets counters. */ | |
800 | static inline int add_entry_to_counter(const struct arpt_entry *e, | |
801 | struct arpt_counters total[], | |
802 | unsigned int *i) | |
803 | { | |
804 | ADD_COUNTER(total[*i], e->counters.bcnt, e->counters.pcnt); | |
805 | ||
806 | (*i)++; | |
807 | return 0; | |
808 | } | |
809 | ||
810 | static void get_counters(const struct arpt_table_info *t, | |
811 | struct arpt_counters counters[]) | |
812 | { | |
813 | unsigned int cpu; | |
814 | unsigned int i; | |
815 | ||
c8923c6b | 816 | for_each_cpu(cpu) { |
1da177e4 LT |
817 | i = 0; |
818 | ARPT_ENTRY_ITERATE(t->entries + TABLE_OFFSET(t, cpu), | |
819 | t->size, | |
820 | add_entry_to_counter, | |
821 | counters, | |
822 | &i); | |
823 | } | |
824 | } | |
825 | ||
826 | static int copy_entries_to_user(unsigned int total_size, | |
827 | struct arpt_table *table, | |
828 | void __user *userptr) | |
829 | { | |
830 | unsigned int off, num, countersize; | |
831 | struct arpt_entry *e; | |
832 | struct arpt_counters *counters; | |
833 | int ret = 0; | |
834 | ||
835 | /* We need atomic snapshot of counters: rest doesn't change | |
836 | * (other than comefrom, which userspace doesn't care | |
837 | * about). | |
838 | */ | |
839 | countersize = sizeof(struct arpt_counters) * table->private->number; | |
840 | counters = vmalloc(countersize); | |
841 | ||
842 | if (counters == NULL) | |
843 | return -ENOMEM; | |
844 | ||
845 | /* First, sum counters... */ | |
846 | memset(counters, 0, countersize); | |
847 | write_lock_bh(&table->lock); | |
848 | get_counters(table->private, counters); | |
849 | write_unlock_bh(&table->lock); | |
850 | ||
851 | /* ... then copy entire thing from CPU 0... */ | |
852 | if (copy_to_user(userptr, table->private->entries, total_size) != 0) { | |
853 | ret = -EFAULT; | |
854 | goto free_counters; | |
855 | } | |
856 | ||
857 | /* FIXME: use iterator macros --RR */ | |
858 | /* ... then go back and fix counters and names */ | |
859 | for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ | |
860 | struct arpt_entry_target *t; | |
861 | ||
862 | e = (struct arpt_entry *)(table->private->entries + off); | |
863 | if (copy_to_user(userptr + off | |
864 | + offsetof(struct arpt_entry, counters), | |
865 | &counters[num], | |
866 | sizeof(counters[num])) != 0) { | |
867 | ret = -EFAULT; | |
868 | goto free_counters; | |
869 | } | |
870 | ||
871 | t = arpt_get_target(e); | |
872 | if (copy_to_user(userptr + off + e->target_offset | |
873 | + offsetof(struct arpt_entry_target, | |
874 | u.user.name), | |
875 | t->u.kernel.target->name, | |
876 | strlen(t->u.kernel.target->name)+1) != 0) { | |
877 | ret = -EFAULT; | |
878 | goto free_counters; | |
879 | } | |
880 | } | |
881 | ||
882 | free_counters: | |
883 | vfree(counters); | |
884 | return ret; | |
885 | } | |
886 | ||
887 | static int get_entries(const struct arpt_get_entries *entries, | |
888 | struct arpt_get_entries __user *uptr) | |
889 | { | |
890 | int ret; | |
891 | struct arpt_table *t; | |
892 | ||
6b7d31fc HW |
893 | t = find_table_lock(entries->name); |
894 | if (t || !IS_ERR(t)) { | |
1da177e4 LT |
895 | duprintf("t->private->number = %u\n", |
896 | t->private->number); | |
897 | if (entries->size == t->private->size) | |
898 | ret = copy_entries_to_user(t->private->size, | |
899 | t, uptr->entrytable); | |
900 | else { | |
901 | duprintf("get_entries: I've got %u not %u!\n", | |
902 | t->private->size, | |
903 | entries->size); | |
904 | ret = -EINVAL; | |
905 | } | |
6b7d31fc | 906 | module_put(t->me); |
1da177e4 LT |
907 | up(&arpt_mutex); |
908 | } else | |
6b7d31fc | 909 | ret = t ? PTR_ERR(t) : -ENOENT; |
1da177e4 LT |
910 | |
911 | return ret; | |
912 | } | |
913 | ||
914 | static int do_replace(void __user *user, unsigned int len) | |
915 | { | |
916 | int ret; | |
917 | struct arpt_replace tmp; | |
918 | struct arpt_table *t; | |
919 | struct arpt_table_info *newinfo, *oldinfo; | |
920 | struct arpt_counters *counters; | |
921 | ||
922 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) | |
923 | return -EFAULT; | |
924 | ||
925 | /* Hack: Causes ipchains to give correct error msg --RR */ | |
926 | if (len != sizeof(tmp) + tmp.size) | |
927 | return -ENOPROTOOPT; | |
928 | ||
929 | /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ | |
930 | if ((SMP_ALIGN(tmp.size) >> PAGE_SHIFT) + 2 > num_physpages) | |
931 | return -ENOMEM; | |
932 | ||
933 | newinfo = vmalloc(sizeof(struct arpt_table_info) | |
c8923c6b DM |
934 | + SMP_ALIGN(tmp.size) * |
935 | (highest_possible_processor_id()+1)); | |
1da177e4 LT |
936 | if (!newinfo) |
937 | return -ENOMEM; | |
938 | ||
939 | if (copy_from_user(newinfo->entries, user + sizeof(tmp), | |
940 | tmp.size) != 0) { | |
941 | ret = -EFAULT; | |
942 | goto free_newinfo; | |
943 | } | |
944 | ||
945 | counters = vmalloc(tmp.num_counters * sizeof(struct arpt_counters)); | |
946 | if (!counters) { | |
947 | ret = -ENOMEM; | |
948 | goto free_newinfo; | |
949 | } | |
950 | memset(counters, 0, tmp.num_counters * sizeof(struct arpt_counters)); | |
951 | ||
952 | ret = translate_table(tmp.name, tmp.valid_hooks, | |
953 | newinfo, tmp.size, tmp.num_entries, | |
954 | tmp.hook_entry, tmp.underflow); | |
955 | if (ret != 0) | |
956 | goto free_newinfo_counters; | |
957 | ||
958 | duprintf("arp_tables: Translated table\n"); | |
959 | ||
6b7d31fc HW |
960 | t = try_then_request_module(find_table_lock(tmp.name), |
961 | "arptable_%s", tmp.name); | |
962 | if (!t || IS_ERR(t)) { | |
963 | ret = t ? PTR_ERR(t) : -ENOENT; | |
1da177e4 | 964 | goto free_newinfo_counters_untrans; |
6b7d31fc | 965 | } |
1da177e4 LT |
966 | |
967 | /* You lied! */ | |
968 | if (tmp.valid_hooks != t->valid_hooks) { | |
969 | duprintf("Valid hook crap: %08X vs %08X\n", | |
970 | tmp.valid_hooks, t->valid_hooks); | |
971 | ret = -EINVAL; | |
6b7d31fc | 972 | goto put_module; |
1da177e4 LT |
973 | } |
974 | ||
975 | oldinfo = replace_table(t, tmp.num_counters, newinfo, &ret); | |
976 | if (!oldinfo) | |
977 | goto put_module; | |
978 | ||
979 | /* Update module usage count based on number of rules */ | |
980 | duprintf("do_replace: oldnum=%u, initnum=%u, newnum=%u\n", | |
981 | oldinfo->number, oldinfo->initial_entries, newinfo->number); | |
982 | if ((oldinfo->number > oldinfo->initial_entries) || | |
983 | (newinfo->number <= oldinfo->initial_entries)) | |
984 | module_put(t->me); | |
985 | if ((oldinfo->number > oldinfo->initial_entries) && | |
986 | (newinfo->number <= oldinfo->initial_entries)) | |
987 | module_put(t->me); | |
988 | ||
989 | /* Get the old counters. */ | |
990 | get_counters(oldinfo, counters); | |
991 | /* Decrease module usage counts and free resource */ | |
992 | ARPT_ENTRY_ITERATE(oldinfo->entries, oldinfo->size, cleanup_entry,NULL); | |
993 | vfree(oldinfo); | |
994 | if (copy_to_user(tmp.counters, counters, | |
995 | sizeof(struct arpt_counters) * tmp.num_counters) != 0) | |
996 | ret = -EFAULT; | |
997 | vfree(counters); | |
998 | up(&arpt_mutex); | |
999 | return ret; | |
1000 | ||
1001 | put_module: | |
1002 | module_put(t->me); | |
1da177e4 LT |
1003 | up(&arpt_mutex); |
1004 | free_newinfo_counters_untrans: | |
1005 | ARPT_ENTRY_ITERATE(newinfo->entries, newinfo->size, cleanup_entry, NULL); | |
1006 | free_newinfo_counters: | |
1007 | vfree(counters); | |
1008 | free_newinfo: | |
1009 | vfree(newinfo); | |
1010 | return ret; | |
1011 | } | |
1012 | ||
1013 | /* We're lazy, and add to the first CPU; overflow works its fey magic | |
1014 | * and everything is OK. | |
1015 | */ | |
1016 | static inline int add_counter_to_entry(struct arpt_entry *e, | |
1017 | const struct arpt_counters addme[], | |
1018 | unsigned int *i) | |
1019 | { | |
1020 | ||
1021 | ADD_COUNTER(e->counters, addme[*i].bcnt, addme[*i].pcnt); | |
1022 | ||
1023 | (*i)++; | |
1024 | return 0; | |
1025 | } | |
1026 | ||
1027 | static int do_add_counters(void __user *user, unsigned int len) | |
1028 | { | |
1029 | unsigned int i; | |
1030 | struct arpt_counters_info tmp, *paddc; | |
1031 | struct arpt_table *t; | |
6b7d31fc | 1032 | int ret = 0; |
1da177e4 LT |
1033 | |
1034 | if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) | |
1035 | return -EFAULT; | |
1036 | ||
1037 | if (len != sizeof(tmp) + tmp.num_counters*sizeof(struct arpt_counters)) | |
1038 | return -EINVAL; | |
1039 | ||
1040 | paddc = vmalloc(len); | |
1041 | if (!paddc) | |
1042 | return -ENOMEM; | |
1043 | ||
1044 | if (copy_from_user(paddc, user, len) != 0) { | |
1045 | ret = -EFAULT; | |
1046 | goto free; | |
1047 | } | |
1048 | ||
6b7d31fc HW |
1049 | t = find_table_lock(tmp.name); |
1050 | if (!t || IS_ERR(t)) { | |
1051 | ret = t ? PTR_ERR(t) : -ENOENT; | |
1da177e4 | 1052 | goto free; |
6b7d31fc | 1053 | } |
1da177e4 LT |
1054 | |
1055 | write_lock_bh(&t->lock); | |
1056 | if (t->private->number != paddc->num_counters) { | |
1057 | ret = -EINVAL; | |
1058 | goto unlock_up_free; | |
1059 | } | |
1060 | ||
1061 | i = 0; | |
1062 | ARPT_ENTRY_ITERATE(t->private->entries, | |
1063 | t->private->size, | |
1064 | add_counter_to_entry, | |
1065 | paddc->counters, | |
1066 | &i); | |
1067 | unlock_up_free: | |
1068 | write_unlock_bh(&t->lock); | |
1069 | up(&arpt_mutex); | |
6b7d31fc | 1070 | module_put(t->me); |
1da177e4 LT |
1071 | free: |
1072 | vfree(paddc); | |
1073 | ||
1074 | return ret; | |
1075 | } | |
1076 | ||
1077 | static int do_arpt_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) | |
1078 | { | |
1079 | int ret; | |
1080 | ||
1081 | if (!capable(CAP_NET_ADMIN)) | |
1082 | return -EPERM; | |
1083 | ||
1084 | switch (cmd) { | |
1085 | case ARPT_SO_SET_REPLACE: | |
1086 | ret = do_replace(user, len); | |
1087 | break; | |
1088 | ||
1089 | case ARPT_SO_SET_ADD_COUNTERS: | |
1090 | ret = do_add_counters(user, len); | |
1091 | break; | |
1092 | ||
1093 | default: | |
1094 | duprintf("do_arpt_set_ctl: unknown request %i\n", cmd); | |
1095 | ret = -EINVAL; | |
1096 | } | |
1097 | ||
1098 | return ret; | |
1099 | } | |
1100 | ||
1101 | static int do_arpt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) | |
1102 | { | |
1103 | int ret; | |
1104 | ||
1105 | if (!capable(CAP_NET_ADMIN)) | |
1106 | return -EPERM; | |
1107 | ||
1108 | switch (cmd) { | |
1109 | case ARPT_SO_GET_INFO: { | |
1110 | char name[ARPT_TABLE_MAXNAMELEN]; | |
1111 | struct arpt_table *t; | |
1112 | ||
1113 | if (*len != sizeof(struct arpt_getinfo)) { | |
1114 | duprintf("length %u != %Zu\n", *len, | |
1115 | sizeof(struct arpt_getinfo)); | |
1116 | ret = -EINVAL; | |
1117 | break; | |
1118 | } | |
1119 | ||
1120 | if (copy_from_user(name, user, sizeof(name)) != 0) { | |
1121 | ret = -EFAULT; | |
1122 | break; | |
1123 | } | |
1124 | name[ARPT_TABLE_MAXNAMELEN-1] = '\0'; | |
6b7d31fc HW |
1125 | |
1126 | t = try_then_request_module(find_table_lock(name), | |
1127 | "arptable_%s", name); | |
1128 | if (t && !IS_ERR(t)) { | |
1da177e4 LT |
1129 | struct arpt_getinfo info; |
1130 | ||
1131 | info.valid_hooks = t->valid_hooks; | |
1132 | memcpy(info.hook_entry, t->private->hook_entry, | |
1133 | sizeof(info.hook_entry)); | |
1134 | memcpy(info.underflow, t->private->underflow, | |
1135 | sizeof(info.underflow)); | |
1136 | info.num_entries = t->private->number; | |
1137 | info.size = t->private->size; | |
1138 | strcpy(info.name, name); | |
1139 | ||
1140 | if (copy_to_user(user, &info, *len) != 0) | |
1141 | ret = -EFAULT; | |
1142 | else | |
1143 | ret = 0; | |
1da177e4 | 1144 | up(&arpt_mutex); |
6b7d31fc HW |
1145 | module_put(t->me); |
1146 | } else | |
1147 | ret = t ? PTR_ERR(t) : -ENOENT; | |
1da177e4 LT |
1148 | } |
1149 | break; | |
1150 | ||
1151 | case ARPT_SO_GET_ENTRIES: { | |
1152 | struct arpt_get_entries get; | |
1153 | ||
1154 | if (*len < sizeof(get)) { | |
1155 | duprintf("get_entries: %u < %Zu\n", *len, sizeof(get)); | |
1156 | ret = -EINVAL; | |
1157 | } else if (copy_from_user(&get, user, sizeof(get)) != 0) { | |
1158 | ret = -EFAULT; | |
1159 | } else if (*len != sizeof(struct arpt_get_entries) + get.size) { | |
1160 | duprintf("get_entries: %u != %Zu\n", *len, | |
1161 | sizeof(struct arpt_get_entries) + get.size); | |
1162 | ret = -EINVAL; | |
1163 | } else | |
1164 | ret = get_entries(&get, user); | |
1165 | break; | |
1166 | } | |
1167 | ||
6b7d31fc HW |
1168 | case ARPT_SO_GET_REVISION_TARGET: { |
1169 | struct arpt_get_revision rev; | |
1170 | ||
1171 | if (*len != sizeof(rev)) { | |
1172 | ret = -EINVAL; | |
1173 | break; | |
1174 | } | |
1175 | if (copy_from_user(&rev, user, sizeof(rev)) != 0) { | |
1176 | ret = -EFAULT; | |
1177 | break; | |
1178 | } | |
1179 | ||
1180 | try_then_request_module(find_revision(rev.name, rev.revision, | |
1181 | target_revfn, &ret), | |
1182 | "arpt_%s", rev.name); | |
1183 | break; | |
1184 | } | |
1185 | ||
1da177e4 LT |
1186 | default: |
1187 | duprintf("do_arpt_get_ctl: unknown request %i\n", cmd); | |
1188 | ret = -EINVAL; | |
1189 | } | |
1190 | ||
1191 | return ret; | |
1192 | } | |
1193 | ||
1194 | /* Registration hooks for targets. */ | |
1195 | int arpt_register_target(struct arpt_target *target) | |
1196 | { | |
1197 | int ret; | |
1198 | ||
1199 | ret = down_interruptible(&arpt_mutex); | |
1200 | if (ret != 0) | |
1201 | return ret; | |
1202 | ||
6b7d31fc | 1203 | list_add(&target->list, &arpt_target); |
1da177e4 | 1204 | up(&arpt_mutex); |
6b7d31fc | 1205 | |
1da177e4 LT |
1206 | return ret; |
1207 | } | |
1208 | ||
1209 | void arpt_unregister_target(struct arpt_target *target) | |
1210 | { | |
1211 | down(&arpt_mutex); | |
1212 | LIST_DELETE(&arpt_target, target); | |
1213 | up(&arpt_mutex); | |
1214 | } | |
1215 | ||
1216 | int arpt_register_table(struct arpt_table *table, | |
1217 | const struct arpt_replace *repl) | |
1218 | { | |
1219 | int ret; | |
1220 | struct arpt_table_info *newinfo; | |
1221 | static struct arpt_table_info bootstrap | |
1222 | = { 0, 0, 0, { 0 }, { 0 }, { } }; | |
1223 | ||
1224 | newinfo = vmalloc(sizeof(struct arpt_table_info) | |
c8923c6b DM |
1225 | + SMP_ALIGN(repl->size) * |
1226 | (highest_possible_processor_id()+1)); | |
1da177e4 LT |
1227 | if (!newinfo) { |
1228 | ret = -ENOMEM; | |
1229 | return ret; | |
1230 | } | |
1231 | memcpy(newinfo->entries, repl->entries, repl->size); | |
1232 | ||
1233 | ret = translate_table(table->name, table->valid_hooks, | |
1234 | newinfo, repl->size, | |
1235 | repl->num_entries, | |
1236 | repl->hook_entry, | |
1237 | repl->underflow); | |
1238 | duprintf("arpt_register_table: translate table gives %d\n", ret); | |
1239 | if (ret != 0) { | |
1240 | vfree(newinfo); | |
1241 | return ret; | |
1242 | } | |
1243 | ||
1244 | ret = down_interruptible(&arpt_mutex); | |
1245 | if (ret != 0) { | |
1246 | vfree(newinfo); | |
1247 | return ret; | |
1248 | } | |
1249 | ||
1250 | /* Don't autoload: we'd eat our tail... */ | |
1251 | if (list_named_find(&arpt_tables, table->name)) { | |
1252 | ret = -EEXIST; | |
1253 | goto free_unlock; | |
1254 | } | |
1255 | ||
1256 | /* Simplifies replace_table code. */ | |
1257 | table->private = &bootstrap; | |
1258 | if (!replace_table(table, 0, newinfo, &ret)) | |
1259 | goto free_unlock; | |
1260 | ||
1261 | duprintf("table->private->number = %u\n", | |
1262 | table->private->number); | |
1263 | ||
1264 | /* save number of initial entries */ | |
1265 | table->private->initial_entries = table->private->number; | |
1266 | ||
1267 | rwlock_init(&table->lock); | |
1268 | list_prepend(&arpt_tables, table); | |
1269 | ||
1270 | unlock: | |
1271 | up(&arpt_mutex); | |
1272 | return ret; | |
1273 | ||
1274 | free_unlock: | |
1275 | vfree(newinfo); | |
1276 | goto unlock; | |
1277 | } | |
1278 | ||
1279 | void arpt_unregister_table(struct arpt_table *table) | |
1280 | { | |
1281 | down(&arpt_mutex); | |
1282 | LIST_DELETE(&arpt_tables, table); | |
1283 | up(&arpt_mutex); | |
1284 | ||
1285 | /* Decrease module usage counts and free resources */ | |
1286 | ARPT_ENTRY_ITERATE(table->private->entries, table->private->size, | |
1287 | cleanup_entry, NULL); | |
1288 | vfree(table->private); | |
1289 | } | |
1290 | ||
1291 | /* The built-in targets: standard (NULL) and error. */ | |
1292 | static struct arpt_target arpt_standard_target = { | |
1293 | .name = ARPT_STANDARD_TARGET, | |
1294 | }; | |
1295 | ||
1296 | static struct arpt_target arpt_error_target = { | |
1297 | .name = ARPT_ERROR_TARGET, | |
1298 | .target = arpt_error, | |
1299 | }; | |
1300 | ||
1301 | static struct nf_sockopt_ops arpt_sockopts = { | |
1302 | .pf = PF_INET, | |
1303 | .set_optmin = ARPT_BASE_CTL, | |
1304 | .set_optmax = ARPT_SO_SET_MAX+1, | |
1305 | .set = do_arpt_set_ctl, | |
1306 | .get_optmin = ARPT_BASE_CTL, | |
1307 | .get_optmax = ARPT_SO_GET_MAX+1, | |
1308 | .get = do_arpt_get_ctl, | |
1309 | }; | |
1310 | ||
1311 | #ifdef CONFIG_PROC_FS | |
1312 | static inline int print_name(const struct arpt_table *t, | |
1313 | off_t start_offset, char *buffer, int length, | |
1314 | off_t *pos, unsigned int *count) | |
1315 | { | |
1316 | if ((*count)++ >= start_offset) { | |
1317 | unsigned int namelen; | |
1318 | ||
1319 | namelen = sprintf(buffer + *pos, "%s\n", t->name); | |
1320 | if (*pos + namelen > length) { | |
1321 | /* Stop iterating */ | |
1322 | return 1; | |
1323 | } | |
1324 | *pos += namelen; | |
1325 | } | |
1326 | return 0; | |
1327 | } | |
1328 | ||
1329 | static int arpt_get_tables(char *buffer, char **start, off_t offset, int length) | |
1330 | { | |
1331 | off_t pos = 0; | |
1332 | unsigned int count = 0; | |
1333 | ||
1334 | if (down_interruptible(&arpt_mutex) != 0) | |
1335 | return 0; | |
1336 | ||
1337 | LIST_FIND(&arpt_tables, print_name, struct arpt_table *, | |
1338 | offset, buffer, length, &pos, &count); | |
1339 | ||
1340 | up(&arpt_mutex); | |
1341 | ||
1342 | /* `start' hack - see fs/proc/generic.c line ~105 */ | |
1343 | *start=(char *)((unsigned long)count-offset); | |
1344 | return pos; | |
1345 | } | |
1346 | #endif /*CONFIG_PROC_FS*/ | |
1347 | ||
1348 | static int __init init(void) | |
1349 | { | |
1350 | int ret; | |
1351 | ||
1352 | /* Noone else will be downing sem now, so we won't sleep */ | |
1353 | down(&arpt_mutex); | |
1354 | list_append(&arpt_target, &arpt_standard_target); | |
1355 | list_append(&arpt_target, &arpt_error_target); | |
1356 | up(&arpt_mutex); | |
1357 | ||
1358 | /* Register setsockopt */ | |
1359 | ret = nf_register_sockopt(&arpt_sockopts); | |
1360 | if (ret < 0) { | |
1361 | duprintf("Unable to register sockopts.\n"); | |
1362 | return ret; | |
1363 | } | |
1364 | ||
1365 | #ifdef CONFIG_PROC_FS | |
1366 | { | |
1367 | struct proc_dir_entry *proc; | |
1368 | ||
1369 | proc = proc_net_create("arp_tables_names", 0, arpt_get_tables); | |
1370 | if (!proc) { | |
1371 | nf_unregister_sockopt(&arpt_sockopts); | |
1372 | return -ENOMEM; | |
1373 | } | |
1374 | proc->owner = THIS_MODULE; | |
1375 | } | |
1376 | #endif | |
1377 | ||
1378 | printk("arp_tables: (C) 2002 David S. Miller\n"); | |
1379 | return 0; | |
1380 | } | |
1381 | ||
1382 | static void __exit fini(void) | |
1383 | { | |
1384 | nf_unregister_sockopt(&arpt_sockopts); | |
1385 | #ifdef CONFIG_PROC_FS | |
1386 | proc_net_remove("arp_tables_names"); | |
1387 | #endif | |
1388 | } | |
1389 | ||
1390 | EXPORT_SYMBOL(arpt_register_table); | |
1391 | EXPORT_SYMBOL(arpt_unregister_table); | |
1392 | EXPORT_SYMBOL(arpt_do_table); | |
1393 | EXPORT_SYMBOL(arpt_register_target); | |
1394 | EXPORT_SYMBOL(arpt_unregister_target); | |
1395 | ||
1396 | module_init(init); | |
1397 | module_exit(fini); |