1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Packet matching code. 4 * 5 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling 6 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> 7 * Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net> 8 */ 9 10 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 11 12 #include <linux/kernel.h> 13 #include <linux/capability.h> 14 #include <linux/in.h> 15 #include <linux/skbuff.h> 16 #include <linux/kmod.h> 17 #include <linux/vmalloc.h> 18 #include <linux/netdevice.h> 19 #include <linux/module.h> 20 #include <linux/poison.h> 21 #include <net/ipv6.h> 22 #include <net/compat.h> 23 #include <linux/uaccess.h> 24 #include <linux/mutex.h> 25 #include <linux/proc_fs.h> 26 #include <linux/err.h> 27 #include <linux/cpumask.h> 28 29 #include <linux/netfilter_ipv6/ip6_tables.h> 30 #include <linux/netfilter/x_tables.h> 31 #include <net/netfilter/nf_log.h> 32 #include "../../netfilter/xt_repldata.h" 33 34 MODULE_LICENSE("GPL"); 35 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 36 MODULE_DESCRIPTION("IPv6 packet filter"); 37 38 void *ip6t_alloc_initial_table(const struct xt_table *info) 39 { 40 return xt_alloc_initial_table(ip6t, IP6T); 41 } 42 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table); 43 44 /* Returns whether matches rule or not. */ 45 /* Performance critical - called for every packet */ 46 static inline bool 47 ip6_packet_match(const struct sk_buff *skb, 48 const char *indev, 49 const char *outdev, 50 const struct ip6t_ip6 *ip6info, 51 unsigned int *protoff, 52 u16 *fragoff, bool *hotdrop) 53 { 54 unsigned long ret; 55 const struct ipv6hdr *ipv6 = ipv6_hdr(skb); 56 57 if (NF_INVF(ip6info, IP6T_INV_SRCIP, 58 ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk, 59 &ip6info->src)) || 60 NF_INVF(ip6info, IP6T_INV_DSTIP, 61 ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk, 62 &ip6info->dst))) 63 return false; 64 65 ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask); 66 67 if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0)) 68 return false; 69 70 ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask); 71 72 if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0)) 73 return false; 74 75 /* ... might want to do something with class and flowlabel here ... */ 76 77 /* look for the desired protocol header */ 78 if (ip6info->flags & IP6T_F_PROTO) { 79 int protohdr; 80 unsigned short _frag_off; 81 82 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL); 83 if (protohdr < 0) { 84 if (_frag_off == 0) 85 *hotdrop = true; 86 return false; 87 } 88 *fragoff = _frag_off; 89 90 if (ip6info->proto == protohdr) { 91 if (ip6info->invflags & IP6T_INV_PROTO) 92 return false; 93 94 return true; 95 } 96 97 /* We need match for the '-p all', too! */ 98 if ((ip6info->proto != 0) && 99 !(ip6info->invflags & IP6T_INV_PROTO)) 100 return false; 101 } 102 return true; 103 } 104 105 /* should be ip6 safe */ 106 static bool 107 ip6_checkentry(const struct ip6t_ip6 *ipv6) 108 { 109 if (ipv6->flags & ~IP6T_F_MASK) 110 return false; 111 if (ipv6->invflags & ~IP6T_INV_MASK) 112 return false; 113 114 return true; 115 } 116 117 static unsigned int 118 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par) 119 { 120 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); 121 122 return NF_DROP; 123 } 124 125 static inline struct ip6t_entry * 126 get_entry(const void *base, unsigned int offset) 127 { 128 return (struct ip6t_entry *)(base + offset); 129 } 130 131 /* All zeroes == unconditional rule. */ 132 /* Mildly perf critical (only if packet tracing is on) */ 133 static inline bool unconditional(const struct ip6t_entry *e) 134 { 135 static const struct ip6t_ip6 uncond; 136 137 return e->target_offset == sizeof(struct ip6t_entry) && 138 memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0; 139 } 140 141 static inline const struct xt_entry_target * 142 ip6t_get_target_c(const struct ip6t_entry *e) 143 { 144 return ip6t_get_target((struct ip6t_entry *)e); 145 } 146 147 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 148 /* This cries for unification! */ 149 static const char *const hooknames[] = { 150 [NF_INET_PRE_ROUTING] = "PREROUTING", 151 [NF_INET_LOCAL_IN] = "INPUT", 152 [NF_INET_FORWARD] = "FORWARD", 153 [NF_INET_LOCAL_OUT] = "OUTPUT", 154 [NF_INET_POST_ROUTING] = "POSTROUTING", 155 }; 156 157 enum nf_ip_trace_comments { 158 NF_IP6_TRACE_COMMENT_RULE, 159 NF_IP6_TRACE_COMMENT_RETURN, 160 NF_IP6_TRACE_COMMENT_POLICY, 161 }; 162 163 static const char *const comments[] = { 164 [NF_IP6_TRACE_COMMENT_RULE] = "rule", 165 [NF_IP6_TRACE_COMMENT_RETURN] = "return", 166 [NF_IP6_TRACE_COMMENT_POLICY] = "policy", 167 }; 168 169 static const struct nf_loginfo trace_loginfo = { 170 .type = NF_LOG_TYPE_LOG, 171 .u = { 172 .log = { 173 .level = LOGLEVEL_WARNING, 174 .logflags = NF_LOG_DEFAULT_MASK, 175 }, 176 }, 177 }; 178 179 /* Mildly perf critical (only if packet tracing is on) */ 180 static inline int 181 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e, 182 const char *hookname, const char **chainname, 183 const char **comment, unsigned int *rulenum) 184 { 185 const struct xt_standard_target *t = (void *)ip6t_get_target_c(s); 186 187 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { 188 /* Head of user chain: ERROR target with chainname */ 189 *chainname = t->target.data; 190 (*rulenum) = 0; 191 } else if (s == e) { 192 (*rulenum)++; 193 194 if (unconditional(s) && 195 strcmp(t->target.u.kernel.target->name, 196 XT_STANDARD_TARGET) == 0 && 197 t->verdict < 0) { 198 /* Tail of chains: STANDARD target (return/policy) */ 199 *comment = *chainname == hookname 200 ? comments[NF_IP6_TRACE_COMMENT_POLICY] 201 : comments[NF_IP6_TRACE_COMMENT_RETURN]; 202 } 203 return 1; 204 } else 205 (*rulenum)++; 206 207 return 0; 208 } 209 210 static void trace_packet(struct net *net, 211 const struct sk_buff *skb, 212 unsigned int hook, 213 const struct net_device *in, 214 const struct net_device *out, 215 const char *tablename, 216 const struct xt_table_info *private, 217 const struct ip6t_entry *e) 218 { 219 const struct ip6t_entry *root; 220 const char *hookname, *chainname, *comment; 221 const struct ip6t_entry *iter; 222 unsigned int rulenum = 0; 223 224 root = get_entry(private->entries, private->hook_entry[hook]); 225 226 hookname = chainname = hooknames[hook]; 227 comment = comments[NF_IP6_TRACE_COMMENT_RULE]; 228 229 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) 230 if (get_chainname_rulenum(iter, e, hookname, 231 &chainname, &comment, &rulenum) != 0) 232 break; 233 234 nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo, 235 "TRACE: %s:%s:%s:%u ", 236 tablename, chainname, comment, rulenum); 237 } 238 #endif 239 240 static inline struct ip6t_entry * 241 ip6t_next_entry(const struct ip6t_entry *entry) 242 { 243 return (void *)entry + entry->next_offset; 244 } 245 246 /* Returns one of the generic firewall policies, like NF_ACCEPT. */ 247 unsigned int 248 ip6t_do_table(void *priv, struct sk_buff *skb, 249 const struct nf_hook_state *state) 250 { 251 const struct xt_table *table = priv; 252 unsigned int hook = state->hook; 253 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); 254 /* Initializing verdict to NF_DROP keeps gcc happy. */ 255 unsigned int verdict = NF_DROP; 256 const char *indev, *outdev; 257 const void *table_base; 258 struct ip6t_entry *e, **jumpstack; 259 unsigned int stackidx, cpu; 260 const struct xt_table_info *private; 261 struct xt_action_param acpar; 262 unsigned int addend; 263 264 /* Initialization */ 265 stackidx = 0; 266 indev = state->in ? state->in->name : nulldevname; 267 outdev = state->out ? state->out->name : nulldevname; 268 /* We handle fragments by dealing with the first fragment as 269 * if it was a normal packet. All other fragments are treated 270 * normally, except that they will NEVER match rules that ask 271 * things we don't know, ie. tcp syn flag or ports). If the 272 * rule is also a fragment-specific rule, non-fragments won't 273 * match it. */ 274 acpar.fragoff = 0; 275 acpar.hotdrop = false; 276 acpar.state = state; 277 278 WARN_ON(!(table->valid_hooks & (1 << hook))); 279 280 local_bh_disable(); 281 addend = xt_write_recseq_begin(); 282 private = READ_ONCE(table->private); /* Address dependency. */ 283 cpu = smp_processor_id(); 284 table_base = private->entries; 285 jumpstack = (struct ip6t_entry **)private->jumpstack[cpu]; 286 287 /* Switch to alternate jumpstack if we're being invoked via TEE. 288 * TEE issues XT_CONTINUE verdict on original skb so we must not 289 * clobber the jumpstack. 290 * 291 * For recursion via REJECT or SYNPROXY the stack will be clobbered 292 * but it is no problem since absolute verdict is issued by these. 293 */ 294 if (static_key_false(&xt_tee_enabled)) 295 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated); 296 297 e = get_entry(table_base, private->hook_entry[hook]); 298 299 do { 300 const struct xt_entry_target *t; 301 const struct xt_entry_match *ematch; 302 struct xt_counters *counter; 303 304 WARN_ON(!e); 305 acpar.thoff = 0; 306 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6, 307 &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) { 308 no_match: 309 e = ip6t_next_entry(e); 310 continue; 311 } 312 313 xt_ematch_foreach(ematch, e) { 314 acpar.match = ematch->u.kernel.match; 315 acpar.matchinfo = ematch->data; 316 if (!acpar.match->match(skb, &acpar)) 317 goto no_match; 318 } 319 320 counter = xt_get_this_cpu_counter(&e->counters); 321 ADD_COUNTER(*counter, skb->len, 1); 322 323 t = ip6t_get_target_c(e); 324 WARN_ON(!t->u.kernel.target); 325 326 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 327 /* The packet is traced: log it */ 328 if (unlikely(skb->nf_trace)) 329 trace_packet(state->net, skb, hook, state->in, 330 state->out, table->name, private, e); 331 #endif 332 /* Standard target? */ 333 if (!t->u.kernel.target->target) { 334 int v; 335 336 v = ((struct xt_standard_target *)t)->verdict; 337 if (v < 0) { 338 /* Pop from stack? */ 339 if (v != XT_RETURN) { 340 verdict = (unsigned int)(-v) - 1; 341 break; 342 } 343 if (stackidx == 0) 344 e = get_entry(table_base, 345 private->underflow[hook]); 346 else 347 e = ip6t_next_entry(jumpstack[--stackidx]); 348 continue; 349 } 350 if (table_base + v != ip6t_next_entry(e) && 351 !(e->ipv6.flags & IP6T_F_GOTO)) { 352 if (unlikely(stackidx >= private->stacksize)) { 353 verdict = NF_DROP; 354 break; 355 } 356 jumpstack[stackidx++] = e; 357 } 358 359 e = get_entry(table_base, v); 360 continue; 361 } 362 363 acpar.target = t->u.kernel.target; 364 acpar.targinfo = t->data; 365 366 verdict = t->u.kernel.target->target(skb, &acpar); 367 if (verdict == XT_CONTINUE) 368 e = ip6t_next_entry(e); 369 else 370 /* Verdict */ 371 break; 372 } while (!acpar.hotdrop); 373 374 xt_write_recseq_end(addend); 375 local_bh_enable(); 376 377 if (acpar.hotdrop) 378 return NF_DROP; 379 else return verdict; 380 } 381 382 /* Figures out from what hook each rule can be called: returns 0 if 383 there are loops. Puts hook bitmask in comefrom. */ 384 static int 385 mark_source_chains(const struct xt_table_info *newinfo, 386 unsigned int valid_hooks, void *entry0, 387 unsigned int *offsets) 388 { 389 unsigned int hook; 390 391 /* No recursion; use packet counter to save back ptrs (reset 392 to 0 as we leave), and comefrom to save source hook bitmask */ 393 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { 394 unsigned int pos = newinfo->hook_entry[hook]; 395 struct ip6t_entry *e = entry0 + pos; 396 397 if (!(valid_hooks & (1 << hook))) 398 continue; 399 400 /* Set initial back pointer. */ 401 e->counters.pcnt = pos; 402 403 for (;;) { 404 const struct xt_standard_target *t 405 = (void *)ip6t_get_target_c(e); 406 int visited = e->comefrom & (1 << hook); 407 408 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) 409 return 0; 410 411 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); 412 413 /* Unconditional return/END. */ 414 if ((unconditional(e) && 415 (strcmp(t->target.u.user.name, 416 XT_STANDARD_TARGET) == 0) && 417 t->verdict < 0) || visited) { 418 unsigned int oldpos, size; 419 420 /* Return: backtrack through the last 421 big jump. */ 422 do { 423 e->comefrom ^= (1<<NF_INET_NUMHOOKS); 424 oldpos = pos; 425 pos = e->counters.pcnt; 426 e->counters.pcnt = 0; 427 428 /* We're at the start. */ 429 if (pos == oldpos) 430 goto next; 431 432 e = entry0 + pos; 433 } while (oldpos == pos + e->next_offset); 434 435 /* Move along one */ 436 size = e->next_offset; 437 e = entry0 + pos + size; 438 if (pos + size >= newinfo->size) 439 return 0; 440 e->counters.pcnt = pos; 441 pos += size; 442 } else { 443 int newpos = t->verdict; 444 445 if (strcmp(t->target.u.user.name, 446 XT_STANDARD_TARGET) == 0 && 447 newpos >= 0) { 448 /* This a jump; chase it. */ 449 if (!xt_find_jump_offset(offsets, newpos, 450 newinfo->number)) 451 return 0; 452 } else { 453 /* ... this is a fallthru */ 454 newpos = pos + e->next_offset; 455 if (newpos >= newinfo->size) 456 return 0; 457 } 458 e = entry0 + newpos; 459 e->counters.pcnt = pos; 460 pos = newpos; 461 } 462 } 463 next: ; 464 } 465 return 1; 466 } 467 468 static void cleanup_match(struct xt_entry_match *m, struct net *net) 469 { 470 struct xt_mtdtor_param par; 471 472 par.net = net; 473 par.match = m->u.kernel.match; 474 par.matchinfo = m->data; 475 par.family = NFPROTO_IPV6; 476 if (par.match->destroy != NULL) 477 par.match->destroy(&par); 478 module_put(par.match->me); 479 } 480 481 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 482 { 483 const struct ip6t_ip6 *ipv6 = par->entryinfo; 484 485 par->match = m->u.kernel.match; 486 par->matchinfo = m->data; 487 488 return xt_check_match(par, m->u.match_size - sizeof(*m), 489 ipv6->proto, ipv6->invflags & IP6T_INV_PROTO); 490 } 491 492 static int 493 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 494 { 495 struct xt_match *match; 496 int ret; 497 498 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 499 m->u.user.revision); 500 if (IS_ERR(match)) 501 return PTR_ERR(match); 502 503 m->u.kernel.match = match; 504 505 ret = check_match(m, par); 506 if (ret) 507 goto err; 508 509 return 0; 510 err: 511 module_put(m->u.kernel.match->me); 512 return ret; 513 } 514 515 static int check_target(struct ip6t_entry *e, struct net *net, const char *name) 516 { 517 struct xt_entry_target *t = ip6t_get_target(e); 518 struct xt_tgchk_param par = { 519 .net = net, 520 .table = name, 521 .entryinfo = e, 522 .target = t->u.kernel.target, 523 .targinfo = t->data, 524 .hook_mask = e->comefrom, 525 .family = NFPROTO_IPV6, 526 }; 527 528 return xt_check_target(&par, t->u.target_size - sizeof(*t), 529 e->ipv6.proto, 530 e->ipv6.invflags & IP6T_INV_PROTO); 531 } 532 533 static int 534 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name, 535 unsigned int size, 536 struct xt_percpu_counter_alloc_state *alloc_state) 537 { 538 struct xt_entry_target *t; 539 struct xt_target *target; 540 int ret; 541 unsigned int j; 542 struct xt_mtchk_param mtpar; 543 struct xt_entry_match *ematch; 544 545 if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) 546 return -ENOMEM; 547 548 j = 0; 549 memset(&mtpar, 0, sizeof(mtpar)); 550 mtpar.net = net; 551 mtpar.table = name; 552 mtpar.entryinfo = &e->ipv6; 553 mtpar.hook_mask = e->comefrom; 554 mtpar.family = NFPROTO_IPV6; 555 xt_ematch_foreach(ematch, e) { 556 ret = find_check_match(ematch, &mtpar); 557 if (ret != 0) 558 goto cleanup_matches; 559 ++j; 560 } 561 562 t = ip6t_get_target(e); 563 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 564 t->u.user.revision); 565 if (IS_ERR(target)) { 566 ret = PTR_ERR(target); 567 goto cleanup_matches; 568 } 569 t->u.kernel.target = target; 570 571 ret = check_target(e, net, name); 572 if (ret) 573 goto err; 574 return 0; 575 err: 576 module_put(t->u.kernel.target->me); 577 cleanup_matches: 578 xt_ematch_foreach(ematch, e) { 579 if (j-- == 0) 580 break; 581 cleanup_match(ematch, net); 582 } 583 584 xt_percpu_counter_free(&e->counters); 585 586 return ret; 587 } 588 589 static bool check_underflow(const struct ip6t_entry *e) 590 { 591 const struct xt_entry_target *t; 592 unsigned int verdict; 593 594 if (!unconditional(e)) 595 return false; 596 t = ip6t_get_target_c(e); 597 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 598 return false; 599 verdict = ((struct xt_standard_target *)t)->verdict; 600 verdict = -verdict - 1; 601 return verdict == NF_DROP || verdict == NF_ACCEPT; 602 } 603 604 static int 605 check_entry_size_and_hooks(struct ip6t_entry *e, 606 struct xt_table_info *newinfo, 607 const unsigned char *base, 608 const unsigned char *limit, 609 const unsigned int *hook_entries, 610 const unsigned int *underflows, 611 unsigned int valid_hooks) 612 { 613 unsigned int h; 614 int err; 615 616 if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 || 617 (unsigned char *)e + sizeof(struct ip6t_entry) >= limit || 618 (unsigned char *)e + e->next_offset > limit) 619 return -EINVAL; 620 621 if (e->next_offset 622 < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) 623 return -EINVAL; 624 625 if (!ip6_checkentry(&e->ipv6)) 626 return -EINVAL; 627 628 err = xt_check_entry_offsets(e, e->elems, e->target_offset, 629 e->next_offset); 630 if (err) 631 return err; 632 633 /* Check hooks & underflows */ 634 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 635 if (!(valid_hooks & (1 << h))) 636 continue; 637 if ((unsigned char *)e - base == hook_entries[h]) 638 newinfo->hook_entry[h] = hook_entries[h]; 639 if ((unsigned char *)e - base == underflows[h]) { 640 if (!check_underflow(e)) 641 return -EINVAL; 642 643 newinfo->underflow[h] = underflows[h]; 644 } 645 } 646 647 /* Clear counters and comefrom */ 648 e->counters = ((struct xt_counters) { 0, 0 }); 649 e->comefrom = 0; 650 return 0; 651 } 652 653 static void cleanup_entry(struct ip6t_entry *e, struct net *net) 654 { 655 struct xt_tgdtor_param par; 656 struct xt_entry_target *t; 657 struct xt_entry_match *ematch; 658 659 /* Cleanup all matches */ 660 xt_ematch_foreach(ematch, e) 661 cleanup_match(ematch, net); 662 t = ip6t_get_target(e); 663 664 par.net = net; 665 par.target = t->u.kernel.target; 666 par.targinfo = t->data; 667 par.family = NFPROTO_IPV6; 668 if (par.target->destroy != NULL) 669 par.target->destroy(&par); 670 module_put(par.target->me); 671 xt_percpu_counter_free(&e->counters); 672 } 673 674 /* Checks and translates the user-supplied table segment (held in 675 newinfo) */ 676 static int 677 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, 678 const struct ip6t_replace *repl) 679 { 680 struct xt_percpu_counter_alloc_state alloc_state = { 0 }; 681 struct ip6t_entry *iter; 682 unsigned int *offsets; 683 unsigned int i; 684 int ret = 0; 685 686 newinfo->size = repl->size; 687 newinfo->number = repl->num_entries; 688 689 /* Init all hooks to impossible value. */ 690 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 691 newinfo->hook_entry[i] = 0xFFFFFFFF; 692 newinfo->underflow[i] = 0xFFFFFFFF; 693 } 694 695 offsets = xt_alloc_entry_offsets(newinfo->number); 696 if (!offsets) 697 return -ENOMEM; 698 i = 0; 699 /* Walk through entries, checking offsets. */ 700 xt_entry_foreach(iter, entry0, newinfo->size) { 701 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 702 entry0 + repl->size, 703 repl->hook_entry, 704 repl->underflow, 705 repl->valid_hooks); 706 if (ret != 0) 707 goto out_free; 708 if (i < repl->num_entries) 709 offsets[i] = (void *)iter - entry0; 710 ++i; 711 if (strcmp(ip6t_get_target(iter)->u.user.name, 712 XT_ERROR_TARGET) == 0) 713 ++newinfo->stacksize; 714 } 715 716 ret = -EINVAL; 717 if (i != repl->num_entries) 718 goto out_free; 719 720 ret = xt_check_table_hooks(newinfo, repl->valid_hooks); 721 if (ret) 722 goto out_free; 723 724 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { 725 ret = -ELOOP; 726 goto out_free; 727 } 728 kvfree(offsets); 729 730 /* Finally, each sanity check must pass */ 731 i = 0; 732 xt_entry_foreach(iter, entry0, newinfo->size) { 733 ret = find_check_entry(iter, net, repl->name, repl->size, 734 &alloc_state); 735 if (ret != 0) 736 break; 737 ++i; 738 } 739 740 if (ret != 0) { 741 xt_entry_foreach(iter, entry0, newinfo->size) { 742 if (i-- == 0) 743 break; 744 cleanup_entry(iter, net); 745 } 746 return ret; 747 } 748 749 return ret; 750 out_free: 751 kvfree(offsets); 752 return ret; 753 } 754 755 static void 756 get_counters(const struct xt_table_info *t, 757 struct xt_counters counters[]) 758 { 759 struct ip6t_entry *iter; 760 unsigned int cpu; 761 unsigned int i; 762 763 for_each_possible_cpu(cpu) { 764 seqcount_t *s = &per_cpu(xt_recseq, cpu); 765 766 i = 0; 767 xt_entry_foreach(iter, t->entries, t->size) { 768 struct xt_counters *tmp; 769 u64 bcnt, pcnt; 770 unsigned int start; 771 772 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 773 do { 774 start = read_seqcount_begin(s); 775 bcnt = tmp->bcnt; 776 pcnt = tmp->pcnt; 777 } while (read_seqcount_retry(s, start)); 778 779 ADD_COUNTER(counters[i], bcnt, pcnt); 780 ++i; 781 cond_resched(); 782 } 783 } 784 } 785 786 static void get_old_counters(const struct xt_table_info *t, 787 struct xt_counters counters[]) 788 { 789 struct ip6t_entry *iter; 790 unsigned int cpu, i; 791 792 for_each_possible_cpu(cpu) { 793 i = 0; 794 xt_entry_foreach(iter, t->entries, t->size) { 795 const struct xt_counters *tmp; 796 797 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 798 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); 799 ++i; 800 } 801 cond_resched(); 802 } 803 } 804 805 static struct xt_counters *alloc_counters(const struct xt_table *table) 806 { 807 unsigned int countersize; 808 struct xt_counters *counters; 809 const struct xt_table_info *private = table->private; 810 811 /* We need atomic snapshot of counters: rest doesn't change 812 (other than comefrom, which userspace doesn't care 813 about). */ 814 countersize = sizeof(struct xt_counters) * private->number; 815 counters = vzalloc(countersize); 816 817 if (counters == NULL) 818 return ERR_PTR(-ENOMEM); 819 820 get_counters(private, counters); 821 822 return counters; 823 } 824 825 static int 826 copy_entries_to_user(unsigned int total_size, 827 const struct xt_table *table, 828 void __user *userptr) 829 { 830 unsigned int off, num; 831 const struct ip6t_entry *e; 832 struct xt_counters *counters; 833 const struct xt_table_info *private = table->private; 834 int ret = 0; 835 const void *loc_cpu_entry; 836 837 counters = alloc_counters(table); 838 if (IS_ERR(counters)) 839 return PTR_ERR(counters); 840 841 loc_cpu_entry = private->entries; 842 843 /* FIXME: use iterator macros --RR */ 844 /* ... then go back and fix counters and names */ 845 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 846 unsigned int i; 847 const struct xt_entry_match *m; 848 const struct xt_entry_target *t; 849 850 e = loc_cpu_entry + off; 851 if (copy_to_user(userptr + off, e, sizeof(*e))) { 852 ret = -EFAULT; 853 goto free_counters; 854 } 855 if (copy_to_user(userptr + off 856 + offsetof(struct ip6t_entry, counters), 857 &counters[num], 858 sizeof(counters[num])) != 0) { 859 ret = -EFAULT; 860 goto free_counters; 861 } 862 863 for (i = sizeof(struct ip6t_entry); 864 i < e->target_offset; 865 i += m->u.match_size) { 866 m = (void *)e + i; 867 868 if (xt_match_to_user(m, userptr + off + i)) { 869 ret = -EFAULT; 870 goto free_counters; 871 } 872 } 873 874 t = ip6t_get_target_c(e); 875 if (xt_target_to_user(t, userptr + off + e->target_offset)) { 876 ret = -EFAULT; 877 goto free_counters; 878 } 879 } 880 881 free_counters: 882 vfree(counters); 883 return ret; 884 } 885 886 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 887 static void compat_standard_from_user(void *dst, const void *src) 888 { 889 int v = *(compat_int_t *)src; 890 891 if (v > 0) 892 v += xt_compat_calc_jump(AF_INET6, v); 893 memcpy(dst, &v, sizeof(v)); 894 } 895 896 static int compat_standard_to_user(void __user *dst, const void *src) 897 { 898 compat_int_t cv = *(int *)src; 899 900 if (cv > 0) 901 cv -= xt_compat_calc_jump(AF_INET6, cv); 902 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; 903 } 904 905 static int compat_calc_entry(const struct ip6t_entry *e, 906 const struct xt_table_info *info, 907 const void *base, struct xt_table_info *newinfo) 908 { 909 const struct xt_entry_match *ematch; 910 const struct xt_entry_target *t; 911 unsigned int entry_offset; 912 int off, i, ret; 913 914 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 915 entry_offset = (void *)e - base; 916 xt_ematch_foreach(ematch, e) 917 off += xt_compat_match_offset(ematch->u.kernel.match); 918 t = ip6t_get_target_c(e); 919 off += xt_compat_target_offset(t->u.kernel.target); 920 newinfo->size -= off; 921 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 922 if (ret) 923 return ret; 924 925 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 926 if (info->hook_entry[i] && 927 (e < (struct ip6t_entry *)(base + info->hook_entry[i]))) 928 newinfo->hook_entry[i] -= off; 929 if (info->underflow[i] && 930 (e < (struct ip6t_entry *)(base + info->underflow[i]))) 931 newinfo->underflow[i] -= off; 932 } 933 return 0; 934 } 935 936 static int compat_table_info(const struct xt_table_info *info, 937 struct xt_table_info *newinfo) 938 { 939 struct ip6t_entry *iter; 940 const void *loc_cpu_entry; 941 int ret; 942 943 if (!newinfo || !info) 944 return -EINVAL; 945 946 /* we dont care about newinfo->entries */ 947 memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); 948 newinfo->initial_entries = 0; 949 loc_cpu_entry = info->entries; 950 ret = xt_compat_init_offsets(AF_INET6, info->number); 951 if (ret) 952 return ret; 953 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 954 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 955 if (ret != 0) 956 return ret; 957 } 958 return 0; 959 } 960 #endif 961 962 static int get_info(struct net *net, void __user *user, const int *len) 963 { 964 char name[XT_TABLE_MAXNAMELEN]; 965 struct xt_table *t; 966 int ret; 967 968 if (*len != sizeof(struct ip6t_getinfo)) 969 return -EINVAL; 970 971 if (copy_from_user(name, user, sizeof(name)) != 0) 972 return -EFAULT; 973 974 name[XT_TABLE_MAXNAMELEN-1] = '\0'; 975 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 976 if (in_compat_syscall()) 977 xt_compat_lock(AF_INET6); 978 #endif 979 t = xt_request_find_table_lock(net, AF_INET6, name); 980 if (!IS_ERR(t)) { 981 struct ip6t_getinfo info; 982 const struct xt_table_info *private = t->private; 983 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 984 struct xt_table_info tmp; 985 986 if (in_compat_syscall()) { 987 ret = compat_table_info(private, &tmp); 988 xt_compat_flush_offsets(AF_INET6); 989 private = &tmp; 990 } 991 #endif 992 memset(&info, 0, sizeof(info)); 993 info.valid_hooks = t->valid_hooks; 994 memcpy(info.hook_entry, private->hook_entry, 995 sizeof(info.hook_entry)); 996 memcpy(info.underflow, private->underflow, 997 sizeof(info.underflow)); 998 info.num_entries = private->number; 999 info.size = private->size; 1000 strcpy(info.name, name); 1001 1002 if (copy_to_user(user, &info, *len) != 0) 1003 ret = -EFAULT; 1004 else 1005 ret = 0; 1006 1007 xt_table_unlock(t); 1008 module_put(t->me); 1009 } else 1010 ret = PTR_ERR(t); 1011 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1012 if (in_compat_syscall()) 1013 xt_compat_unlock(AF_INET6); 1014 #endif 1015 return ret; 1016 } 1017 1018 static int 1019 get_entries(struct net *net, struct ip6t_get_entries __user *uptr, 1020 const int *len) 1021 { 1022 int ret; 1023 struct ip6t_get_entries get; 1024 struct xt_table *t; 1025 1026 if (*len < sizeof(get)) 1027 return -EINVAL; 1028 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1029 return -EFAULT; 1030 if (*len != sizeof(struct ip6t_get_entries) + get.size) 1031 return -EINVAL; 1032 1033 get.name[sizeof(get.name) - 1] = '\0'; 1034 1035 t = xt_find_table_lock(net, AF_INET6, get.name); 1036 if (!IS_ERR(t)) { 1037 struct xt_table_info *private = t->private; 1038 if (get.size == private->size) 1039 ret = copy_entries_to_user(private->size, 1040 t, uptr->entrytable); 1041 else 1042 ret = -EAGAIN; 1043 1044 module_put(t->me); 1045 xt_table_unlock(t); 1046 } else 1047 ret = PTR_ERR(t); 1048 1049 return ret; 1050 } 1051 1052 static int 1053 __do_replace(struct net *net, const char *name, unsigned int valid_hooks, 1054 struct xt_table_info *newinfo, unsigned int num_counters, 1055 void __user *counters_ptr) 1056 { 1057 int ret; 1058 struct xt_table *t; 1059 struct xt_table_info *oldinfo; 1060 struct xt_counters *counters; 1061 struct ip6t_entry *iter; 1062 1063 counters = xt_counters_alloc(num_counters); 1064 if (!counters) { 1065 ret = -ENOMEM; 1066 goto out; 1067 } 1068 1069 t = xt_request_find_table_lock(net, AF_INET6, name); 1070 if (IS_ERR(t)) { 1071 ret = PTR_ERR(t); 1072 goto free_newinfo_counters_untrans; 1073 } 1074 1075 /* You lied! */ 1076 if (valid_hooks != t->valid_hooks) { 1077 ret = -EINVAL; 1078 goto put_module; 1079 } 1080 1081 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1082 if (!oldinfo) 1083 goto put_module; 1084 1085 /* Update module usage count based on number of rules */ 1086 if ((oldinfo->number > oldinfo->initial_entries) || 1087 (newinfo->number <= oldinfo->initial_entries)) 1088 module_put(t->me); 1089 if ((oldinfo->number > oldinfo->initial_entries) && 1090 (newinfo->number <= oldinfo->initial_entries)) 1091 module_put(t->me); 1092 1093 xt_table_unlock(t); 1094 1095 get_old_counters(oldinfo, counters); 1096 1097 /* Decrease module usage counts and free resource */ 1098 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) 1099 cleanup_entry(iter, net); 1100 1101 xt_free_table_info(oldinfo); 1102 if (copy_to_user(counters_ptr, counters, 1103 sizeof(struct xt_counters) * num_counters) != 0) { 1104 /* Silent error, can't fail, new table is already in place */ 1105 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n"); 1106 } 1107 vfree(counters); 1108 return 0; 1109 1110 put_module: 1111 module_put(t->me); 1112 xt_table_unlock(t); 1113 free_newinfo_counters_untrans: 1114 vfree(counters); 1115 out: 1116 return ret; 1117 } 1118 1119 static int 1120 do_replace(struct net *net, sockptr_t arg, unsigned int len) 1121 { 1122 int ret; 1123 struct ip6t_replace tmp; 1124 struct xt_table_info *newinfo; 1125 void *loc_cpu_entry; 1126 struct ip6t_entry *iter; 1127 1128 if (len < sizeof(tmp)) 1129 return -EINVAL; 1130 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1131 return -EFAULT; 1132 1133 /* overflow check */ 1134 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1135 return -ENOMEM; 1136 if (tmp.num_counters == 0) 1137 return -EINVAL; 1138 if ((u64)len < (u64)tmp.size + sizeof(tmp)) 1139 return -EINVAL; 1140 1141 tmp.name[sizeof(tmp.name)-1] = 0; 1142 1143 newinfo = xt_alloc_table_info(tmp.size); 1144 if (!newinfo) 1145 return -ENOMEM; 1146 1147 loc_cpu_entry = newinfo->entries; 1148 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1149 tmp.size) != 0) { 1150 ret = -EFAULT; 1151 goto free_newinfo; 1152 } 1153 1154 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); 1155 if (ret != 0) 1156 goto free_newinfo; 1157 1158 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1159 tmp.num_counters, tmp.counters); 1160 if (ret) 1161 goto free_newinfo_untrans; 1162 return 0; 1163 1164 free_newinfo_untrans: 1165 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1166 cleanup_entry(iter, net); 1167 free_newinfo: 1168 xt_free_table_info(newinfo); 1169 return ret; 1170 } 1171 1172 static int 1173 do_add_counters(struct net *net, sockptr_t arg, unsigned int len) 1174 { 1175 unsigned int i; 1176 struct xt_counters_info tmp; 1177 struct xt_counters *paddc; 1178 struct xt_table *t; 1179 const struct xt_table_info *private; 1180 int ret = 0; 1181 struct ip6t_entry *iter; 1182 unsigned int addend; 1183 1184 paddc = xt_copy_counters(arg, len, &tmp); 1185 if (IS_ERR(paddc)) 1186 return PTR_ERR(paddc); 1187 t = xt_find_table_lock(net, AF_INET6, tmp.name); 1188 if (IS_ERR(t)) { 1189 ret = PTR_ERR(t); 1190 goto free; 1191 } 1192 1193 local_bh_disable(); 1194 private = t->private; 1195 if (private->number != tmp.num_counters) { 1196 ret = -EINVAL; 1197 goto unlock_up_free; 1198 } 1199 1200 i = 0; 1201 addend = xt_write_recseq_begin(); 1202 xt_entry_foreach(iter, private->entries, private->size) { 1203 struct xt_counters *tmp; 1204 1205 tmp = xt_get_this_cpu_counter(&iter->counters); 1206 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); 1207 ++i; 1208 } 1209 xt_write_recseq_end(addend); 1210 unlock_up_free: 1211 local_bh_enable(); 1212 xt_table_unlock(t); 1213 module_put(t->me); 1214 free: 1215 vfree(paddc); 1216 1217 return ret; 1218 } 1219 1220 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1221 struct compat_ip6t_replace { 1222 char name[XT_TABLE_MAXNAMELEN]; 1223 u32 valid_hooks; 1224 u32 num_entries; 1225 u32 size; 1226 u32 hook_entry[NF_INET_NUMHOOKS]; 1227 u32 underflow[NF_INET_NUMHOOKS]; 1228 u32 num_counters; 1229 compat_uptr_t counters; /* struct xt_counters * */ 1230 struct compat_ip6t_entry entries[]; 1231 }; 1232 1233 static int 1234 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr, 1235 unsigned int *size, struct xt_counters *counters, 1236 unsigned int i) 1237 { 1238 struct xt_entry_target *t; 1239 struct compat_ip6t_entry __user *ce; 1240 u_int16_t target_offset, next_offset; 1241 compat_uint_t origsize; 1242 const struct xt_entry_match *ematch; 1243 int ret = 0; 1244 1245 origsize = *size; 1246 ce = *dstptr; 1247 if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 || 1248 copy_to_user(&ce->counters, &counters[i], 1249 sizeof(counters[i])) != 0) 1250 return -EFAULT; 1251 1252 *dstptr += sizeof(struct compat_ip6t_entry); 1253 *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1254 1255 xt_ematch_foreach(ematch, e) { 1256 ret = xt_compat_match_to_user(ematch, dstptr, size); 1257 if (ret != 0) 1258 return ret; 1259 } 1260 target_offset = e->target_offset - (origsize - *size); 1261 t = ip6t_get_target(e); 1262 ret = xt_compat_target_to_user(t, dstptr, size); 1263 if (ret) 1264 return ret; 1265 next_offset = e->next_offset - (origsize - *size); 1266 if (put_user(target_offset, &ce->target_offset) != 0 || 1267 put_user(next_offset, &ce->next_offset) != 0) 1268 return -EFAULT; 1269 return 0; 1270 } 1271 1272 static int 1273 compat_find_calc_match(struct xt_entry_match *m, 1274 const struct ip6t_ip6 *ipv6, 1275 int *size) 1276 { 1277 struct xt_match *match; 1278 1279 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 1280 m->u.user.revision); 1281 if (IS_ERR(match)) 1282 return PTR_ERR(match); 1283 1284 m->u.kernel.match = match; 1285 *size += xt_compat_match_offset(match); 1286 return 0; 1287 } 1288 1289 static void compat_release_entry(struct compat_ip6t_entry *e) 1290 { 1291 struct xt_entry_target *t; 1292 struct xt_entry_match *ematch; 1293 1294 /* Cleanup all matches */ 1295 xt_ematch_foreach(ematch, e) 1296 module_put(ematch->u.kernel.match->me); 1297 t = compat_ip6t_get_target(e); 1298 module_put(t->u.kernel.target->me); 1299 } 1300 1301 static int 1302 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e, 1303 struct xt_table_info *newinfo, 1304 unsigned int *size, 1305 const unsigned char *base, 1306 const unsigned char *limit) 1307 { 1308 struct xt_entry_match *ematch; 1309 struct xt_entry_target *t; 1310 struct xt_target *target; 1311 unsigned int entry_offset; 1312 unsigned int j; 1313 int ret, off; 1314 1315 if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 || 1316 (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit || 1317 (unsigned char *)e + e->next_offset > limit) 1318 return -EINVAL; 1319 1320 if (e->next_offset < sizeof(struct compat_ip6t_entry) + 1321 sizeof(struct compat_xt_entry_target)) 1322 return -EINVAL; 1323 1324 if (!ip6_checkentry(&e->ipv6)) 1325 return -EINVAL; 1326 1327 ret = xt_compat_check_entry_offsets(e, e->elems, 1328 e->target_offset, e->next_offset); 1329 if (ret) 1330 return ret; 1331 1332 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1333 entry_offset = (void *)e - (void *)base; 1334 j = 0; 1335 xt_ematch_foreach(ematch, e) { 1336 ret = compat_find_calc_match(ematch, &e->ipv6, &off); 1337 if (ret != 0) 1338 goto release_matches; 1339 ++j; 1340 } 1341 1342 t = compat_ip6t_get_target(e); 1343 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 1344 t->u.user.revision); 1345 if (IS_ERR(target)) { 1346 ret = PTR_ERR(target); 1347 goto release_matches; 1348 } 1349 t->u.kernel.target = target; 1350 1351 off += xt_compat_target_offset(target); 1352 *size += off; 1353 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 1354 if (ret) 1355 goto out; 1356 1357 return 0; 1358 1359 out: 1360 module_put(t->u.kernel.target->me); 1361 release_matches: 1362 xt_ematch_foreach(ematch, e) { 1363 if (j-- == 0) 1364 break; 1365 module_put(ematch->u.kernel.match->me); 1366 } 1367 return ret; 1368 } 1369 1370 static void 1371 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, 1372 unsigned int *size, 1373 struct xt_table_info *newinfo, unsigned char *base) 1374 { 1375 struct xt_entry_target *t; 1376 struct ip6t_entry *de; 1377 unsigned int origsize; 1378 int h; 1379 struct xt_entry_match *ematch; 1380 1381 origsize = *size; 1382 de = *dstptr; 1383 memcpy(de, e, sizeof(struct ip6t_entry)); 1384 memcpy(&de->counters, &e->counters, sizeof(e->counters)); 1385 1386 *dstptr += sizeof(struct ip6t_entry); 1387 *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1388 1389 xt_ematch_foreach(ematch, e) 1390 xt_compat_match_from_user(ematch, dstptr, size); 1391 1392 de->target_offset = e->target_offset - (origsize - *size); 1393 t = compat_ip6t_get_target(e); 1394 xt_compat_target_from_user(t, dstptr, size); 1395 1396 de->next_offset = e->next_offset - (origsize - *size); 1397 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 1398 if ((unsigned char *)de - base < newinfo->hook_entry[h]) 1399 newinfo->hook_entry[h] -= origsize - *size; 1400 if ((unsigned char *)de - base < newinfo->underflow[h]) 1401 newinfo->underflow[h] -= origsize - *size; 1402 } 1403 } 1404 1405 static int 1406 translate_compat_table(struct net *net, 1407 struct xt_table_info **pinfo, 1408 void **pentry0, 1409 const struct compat_ip6t_replace *compatr) 1410 { 1411 unsigned int i, j; 1412 struct xt_table_info *newinfo, *info; 1413 void *pos, *entry0, *entry1; 1414 struct compat_ip6t_entry *iter0; 1415 struct ip6t_replace repl; 1416 unsigned int size; 1417 int ret; 1418 1419 info = *pinfo; 1420 entry0 = *pentry0; 1421 size = compatr->size; 1422 info->number = compatr->num_entries; 1423 1424 j = 0; 1425 xt_compat_lock(AF_INET6); 1426 ret = xt_compat_init_offsets(AF_INET6, compatr->num_entries); 1427 if (ret) 1428 goto out_unlock; 1429 /* Walk through entries, checking offsets. */ 1430 xt_entry_foreach(iter0, entry0, compatr->size) { 1431 ret = check_compat_entry_size_and_hooks(iter0, info, &size, 1432 entry0, 1433 entry0 + compatr->size); 1434 if (ret != 0) 1435 goto out_unlock; 1436 ++j; 1437 } 1438 1439 ret = -EINVAL; 1440 if (j != compatr->num_entries) 1441 goto out_unlock; 1442 1443 ret = -ENOMEM; 1444 newinfo = xt_alloc_table_info(size); 1445 if (!newinfo) 1446 goto out_unlock; 1447 1448 memset(newinfo->entries, 0, size); 1449 1450 newinfo->number = compatr->num_entries; 1451 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1452 newinfo->hook_entry[i] = compatr->hook_entry[i]; 1453 newinfo->underflow[i] = compatr->underflow[i]; 1454 } 1455 entry1 = newinfo->entries; 1456 pos = entry1; 1457 size = compatr->size; 1458 xt_entry_foreach(iter0, entry0, compatr->size) 1459 compat_copy_entry_from_user(iter0, &pos, &size, 1460 newinfo, entry1); 1461 1462 /* all module references in entry0 are now gone. */ 1463 xt_compat_flush_offsets(AF_INET6); 1464 xt_compat_unlock(AF_INET6); 1465 1466 memcpy(&repl, compatr, sizeof(*compatr)); 1467 1468 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1469 repl.hook_entry[i] = newinfo->hook_entry[i]; 1470 repl.underflow[i] = newinfo->underflow[i]; 1471 } 1472 1473 repl.num_counters = 0; 1474 repl.counters = NULL; 1475 repl.size = newinfo->size; 1476 ret = translate_table(net, newinfo, entry1, &repl); 1477 if (ret) 1478 goto free_newinfo; 1479 1480 *pinfo = newinfo; 1481 *pentry0 = entry1; 1482 xt_free_table_info(info); 1483 return 0; 1484 1485 free_newinfo: 1486 xt_free_table_info(newinfo); 1487 return ret; 1488 out_unlock: 1489 xt_compat_flush_offsets(AF_INET6); 1490 xt_compat_unlock(AF_INET6); 1491 xt_entry_foreach(iter0, entry0, compatr->size) { 1492 if (j-- == 0) 1493 break; 1494 compat_release_entry(iter0); 1495 } 1496 return ret; 1497 } 1498 1499 static int 1500 compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) 1501 { 1502 int ret; 1503 struct compat_ip6t_replace tmp; 1504 struct xt_table_info *newinfo; 1505 void *loc_cpu_entry; 1506 struct ip6t_entry *iter; 1507 1508 if (len < sizeof(tmp)) 1509 return -EINVAL; 1510 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1511 return -EFAULT; 1512 1513 /* overflow check */ 1514 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1515 return -ENOMEM; 1516 if (tmp.num_counters == 0) 1517 return -EINVAL; 1518 if ((u64)len < (u64)tmp.size + sizeof(tmp)) 1519 return -EINVAL; 1520 1521 tmp.name[sizeof(tmp.name)-1] = 0; 1522 1523 newinfo = xt_alloc_table_info(tmp.size); 1524 if (!newinfo) 1525 return -ENOMEM; 1526 1527 loc_cpu_entry = newinfo->entries; 1528 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1529 tmp.size) != 0) { 1530 ret = -EFAULT; 1531 goto free_newinfo; 1532 } 1533 1534 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); 1535 if (ret != 0) 1536 goto free_newinfo; 1537 1538 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1539 tmp.num_counters, compat_ptr(tmp.counters)); 1540 if (ret) 1541 goto free_newinfo_untrans; 1542 return 0; 1543 1544 free_newinfo_untrans: 1545 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1546 cleanup_entry(iter, net); 1547 free_newinfo: 1548 xt_free_table_info(newinfo); 1549 return ret; 1550 } 1551 1552 struct compat_ip6t_get_entries { 1553 char name[XT_TABLE_MAXNAMELEN]; 1554 compat_uint_t size; 1555 struct compat_ip6t_entry entrytable[]; 1556 }; 1557 1558 static int 1559 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, 1560 void __user *userptr) 1561 { 1562 struct xt_counters *counters; 1563 const struct xt_table_info *private = table->private; 1564 void __user *pos; 1565 unsigned int size; 1566 int ret = 0; 1567 unsigned int i = 0; 1568 struct ip6t_entry *iter; 1569 1570 counters = alloc_counters(table); 1571 if (IS_ERR(counters)) 1572 return PTR_ERR(counters); 1573 1574 pos = userptr; 1575 size = total_size; 1576 xt_entry_foreach(iter, private->entries, total_size) { 1577 ret = compat_copy_entry_to_user(iter, &pos, 1578 &size, counters, i++); 1579 if (ret != 0) 1580 break; 1581 } 1582 1583 vfree(counters); 1584 return ret; 1585 } 1586 1587 static int 1588 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr, 1589 int *len) 1590 { 1591 int ret; 1592 struct compat_ip6t_get_entries get; 1593 struct xt_table *t; 1594 1595 if (*len < sizeof(get)) 1596 return -EINVAL; 1597 1598 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1599 return -EFAULT; 1600 1601 if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) 1602 return -EINVAL; 1603 1604 get.name[sizeof(get.name) - 1] = '\0'; 1605 1606 xt_compat_lock(AF_INET6); 1607 t = xt_find_table_lock(net, AF_INET6, get.name); 1608 if (!IS_ERR(t)) { 1609 const struct xt_table_info *private = t->private; 1610 struct xt_table_info info; 1611 ret = compat_table_info(private, &info); 1612 if (!ret && get.size == info.size) 1613 ret = compat_copy_entries_to_user(private->size, 1614 t, uptr->entrytable); 1615 else if (!ret) 1616 ret = -EAGAIN; 1617 1618 xt_compat_flush_offsets(AF_INET6); 1619 module_put(t->me); 1620 xt_table_unlock(t); 1621 } else 1622 ret = PTR_ERR(t); 1623 1624 xt_compat_unlock(AF_INET6); 1625 return ret; 1626 } 1627 #endif 1628 1629 static int 1630 do_ip6t_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len) 1631 { 1632 int ret; 1633 1634 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1635 return -EPERM; 1636 1637 switch (cmd) { 1638 case IP6T_SO_SET_REPLACE: 1639 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1640 if (in_compat_syscall()) 1641 ret = compat_do_replace(sock_net(sk), arg, len); 1642 else 1643 #endif 1644 ret = do_replace(sock_net(sk), arg, len); 1645 break; 1646 1647 case IP6T_SO_SET_ADD_COUNTERS: 1648 ret = do_add_counters(sock_net(sk), arg, len); 1649 break; 1650 1651 default: 1652 ret = -EINVAL; 1653 } 1654 1655 return ret; 1656 } 1657 1658 static int 1659 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1660 { 1661 int ret; 1662 1663 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1664 return -EPERM; 1665 1666 switch (cmd) { 1667 case IP6T_SO_GET_INFO: 1668 ret = get_info(sock_net(sk), user, len); 1669 break; 1670 1671 case IP6T_SO_GET_ENTRIES: 1672 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1673 if (in_compat_syscall()) 1674 ret = compat_get_entries(sock_net(sk), user, len); 1675 else 1676 #endif 1677 ret = get_entries(sock_net(sk), user, len); 1678 break; 1679 1680 case IP6T_SO_GET_REVISION_MATCH: 1681 case IP6T_SO_GET_REVISION_TARGET: { 1682 struct xt_get_revision rev; 1683 int target; 1684 1685 if (*len != sizeof(rev)) { 1686 ret = -EINVAL; 1687 break; 1688 } 1689 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1690 ret = -EFAULT; 1691 break; 1692 } 1693 rev.name[sizeof(rev.name)-1] = 0; 1694 1695 if (cmd == IP6T_SO_GET_REVISION_TARGET) 1696 target = 1; 1697 else 1698 target = 0; 1699 1700 try_then_request_module(xt_find_revision(AF_INET6, rev.name, 1701 rev.revision, 1702 target, &ret), 1703 "ip6t_%s", rev.name); 1704 break; 1705 } 1706 1707 default: 1708 ret = -EINVAL; 1709 } 1710 1711 return ret; 1712 } 1713 1714 static void __ip6t_unregister_table(struct net *net, struct xt_table *table) 1715 { 1716 struct xt_table_info *private; 1717 void *loc_cpu_entry; 1718 struct module *table_owner = table->me; 1719 struct ip6t_entry *iter; 1720 1721 private = xt_unregister_table(table); 1722 1723 /* Decrease module usage counts and free resources */ 1724 loc_cpu_entry = private->entries; 1725 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1726 cleanup_entry(iter, net); 1727 if (private->number > private->initial_entries) 1728 module_put(table_owner); 1729 xt_free_table_info(private); 1730 } 1731 1732 int ip6t_register_table(struct net *net, const struct xt_table *table, 1733 const struct ip6t_replace *repl, 1734 const struct nf_hook_ops *template_ops) 1735 { 1736 struct nf_hook_ops *ops; 1737 unsigned int num_ops; 1738 int ret, i; 1739 struct xt_table_info *newinfo; 1740 struct xt_table_info bootstrap = {0}; 1741 void *loc_cpu_entry; 1742 struct xt_table *new_table; 1743 1744 newinfo = xt_alloc_table_info(repl->size); 1745 if (!newinfo) 1746 return -ENOMEM; 1747 1748 loc_cpu_entry = newinfo->entries; 1749 memcpy(loc_cpu_entry, repl->entries, repl->size); 1750 1751 ret = translate_table(net, newinfo, loc_cpu_entry, repl); 1752 if (ret != 0) { 1753 xt_free_table_info(newinfo); 1754 return ret; 1755 } 1756 1757 new_table = xt_register_table(net, table, &bootstrap, newinfo); 1758 if (IS_ERR(new_table)) { 1759 struct ip6t_entry *iter; 1760 1761 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1762 cleanup_entry(iter, net); 1763 xt_free_table_info(newinfo); 1764 return PTR_ERR(new_table); 1765 } 1766 1767 if (!template_ops) 1768 return 0; 1769 1770 num_ops = hweight32(table->valid_hooks); 1771 if (num_ops == 0) { 1772 ret = -EINVAL; 1773 goto out_free; 1774 } 1775 1776 ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL); 1777 if (!ops) { 1778 ret = -ENOMEM; 1779 goto out_free; 1780 } 1781 1782 for (i = 0; i < num_ops; i++) 1783 ops[i].priv = new_table; 1784 1785 new_table->ops = ops; 1786 1787 ret = nf_register_net_hooks(net, ops, num_ops); 1788 if (ret != 0) 1789 goto out_free; 1790 1791 return ret; 1792 1793 out_free: 1794 __ip6t_unregister_table(net, new_table); 1795 return ret; 1796 } 1797 1798 void ip6t_unregister_table_pre_exit(struct net *net, const char *name) 1799 { 1800 struct xt_table *table = xt_find_table(net, NFPROTO_IPV6, name); 1801 1802 if (table) 1803 nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks)); 1804 } 1805 1806 void ip6t_unregister_table_exit(struct net *net, const char *name) 1807 { 1808 struct xt_table *table = xt_find_table(net, NFPROTO_IPV6, name); 1809 1810 if (table) 1811 __ip6t_unregister_table(net, table); 1812 } 1813 1814 /* The built-in targets: standard (NULL) and error. */ 1815 static struct xt_target ip6t_builtin_tg[] __read_mostly = { 1816 { 1817 .name = XT_STANDARD_TARGET, 1818 .targetsize = sizeof(int), 1819 .family = NFPROTO_IPV6, 1820 #ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1821 .compatsize = sizeof(compat_int_t), 1822 .compat_from_user = compat_standard_from_user, 1823 .compat_to_user = compat_standard_to_user, 1824 #endif 1825 }, 1826 { 1827 .name = XT_ERROR_TARGET, 1828 .target = ip6t_error, 1829 .targetsize = XT_FUNCTION_MAXNAMELEN, 1830 .family = NFPROTO_IPV6, 1831 }, 1832 }; 1833 1834 static struct nf_sockopt_ops ip6t_sockopts = { 1835 .pf = PF_INET6, 1836 .set_optmin = IP6T_BASE_CTL, 1837 .set_optmax = IP6T_SO_SET_MAX+1, 1838 .set = do_ip6t_set_ctl, 1839 .get_optmin = IP6T_BASE_CTL, 1840 .get_optmax = IP6T_SO_GET_MAX+1, 1841 .get = do_ip6t_get_ctl, 1842 .owner = THIS_MODULE, 1843 }; 1844 1845 static int __net_init ip6_tables_net_init(struct net *net) 1846 { 1847 return xt_proto_init(net, NFPROTO_IPV6); 1848 } 1849 1850 static void __net_exit ip6_tables_net_exit(struct net *net) 1851 { 1852 xt_proto_fini(net, NFPROTO_IPV6); 1853 } 1854 1855 static struct pernet_operations ip6_tables_net_ops = { 1856 .init = ip6_tables_net_init, 1857 .exit = ip6_tables_net_exit, 1858 }; 1859 1860 static int __init ip6_tables_init(void) 1861 { 1862 int ret; 1863 1864 ret = register_pernet_subsys(&ip6_tables_net_ops); 1865 if (ret < 0) 1866 goto err1; 1867 1868 /* No one else will be downing sem now, so we won't sleep */ 1869 ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1870 if (ret < 0) 1871 goto err2; 1872 1873 /* Register setsockopt */ 1874 ret = nf_register_sockopt(&ip6t_sockopts); 1875 if (ret < 0) 1876 goto err4; 1877 1878 return 0; 1879 1880 err4: 1881 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1882 err2: 1883 unregister_pernet_subsys(&ip6_tables_net_ops); 1884 err1: 1885 return ret; 1886 } 1887 1888 static void __exit ip6_tables_fini(void) 1889 { 1890 nf_unregister_sockopt(&ip6t_sockopts); 1891 1892 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1893 unregister_pernet_subsys(&ip6_tables_net_ops); 1894 } 1895 1896 EXPORT_SYMBOL(ip6t_register_table); 1897 EXPORT_SYMBOL(ip6t_unregister_table_pre_exit); 1898 EXPORT_SYMBOL(ip6t_unregister_table_exit); 1899 EXPORT_SYMBOL(ip6t_do_table); 1900 1901 module_init(ip6_tables_init); 1902 module_exit(ip6_tables_fini); 1903