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 <linux/icmpv6.h> 22 #include <net/ipv6.h> 23 #include <net/compat.h> 24 #include <linux/uaccess.h> 25 #include <linux/mutex.h> 26 #include <linux/proc_fs.h> 27 #include <linux/err.h> 28 #include <linux/cpumask.h> 29 30 #include <linux/netfilter_ipv6/ip6_tables.h> 31 #include <linux/netfilter/x_tables.h> 32 #include <net/netfilter/nf_log.h> 33 #include "../../netfilter/xt_repldata.h" 34 35 MODULE_LICENSE("GPL"); 36 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 37 MODULE_DESCRIPTION("IPv6 packet filter"); 38 MODULE_ALIAS("ip6t_icmp6"); 39 40 void *ip6t_alloc_initial_table(const struct xt_table *info) 41 { 42 return xt_alloc_initial_table(ip6t, IP6T); 43 } 44 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table); 45 46 /* Returns whether matches rule or not. */ 47 /* Performance critical - called for every packet */ 48 static inline bool 49 ip6_packet_match(const struct sk_buff *skb, 50 const char *indev, 51 const char *outdev, 52 const struct ip6t_ip6 *ip6info, 53 unsigned int *protoff, 54 int *fragoff, bool *hotdrop) 55 { 56 unsigned long ret; 57 const struct ipv6hdr *ipv6 = ipv6_hdr(skb); 58 59 if (NF_INVF(ip6info, IP6T_INV_SRCIP, 60 ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk, 61 &ip6info->src)) || 62 NF_INVF(ip6info, IP6T_INV_DSTIP, 63 ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk, 64 &ip6info->dst))) 65 return false; 66 67 ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask); 68 69 if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0)) 70 return false; 71 72 ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask); 73 74 if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0)) 75 return false; 76 77 /* ... might want to do something with class and flowlabel here ... */ 78 79 /* look for the desired protocol header */ 80 if (ip6info->flags & IP6T_F_PROTO) { 81 int protohdr; 82 unsigned short _frag_off; 83 84 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL); 85 if (protohdr < 0) { 86 if (_frag_off == 0) 87 *hotdrop = true; 88 return false; 89 } 90 *fragoff = _frag_off; 91 92 if (ip6info->proto == protohdr) { 93 if (ip6info->invflags & IP6T_INV_PROTO) 94 return false; 95 96 return true; 97 } 98 99 /* We need match for the '-p all', too! */ 100 if ((ip6info->proto != 0) && 101 !(ip6info->invflags & IP6T_INV_PROTO)) 102 return false; 103 } 104 return true; 105 } 106 107 /* should be ip6 safe */ 108 static bool 109 ip6_checkentry(const struct ip6t_ip6 *ipv6) 110 { 111 if (ipv6->flags & ~IP6T_F_MASK) 112 return false; 113 if (ipv6->invflags & ~IP6T_INV_MASK) 114 return false; 115 116 return true; 117 } 118 119 static unsigned int 120 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par) 121 { 122 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); 123 124 return NF_DROP; 125 } 126 127 static inline struct ip6t_entry * 128 get_entry(const void *base, unsigned int offset) 129 { 130 return (struct ip6t_entry *)(base + offset); 131 } 132 133 /* All zeroes == unconditional rule. */ 134 /* Mildly perf critical (only if packet tracing is on) */ 135 static inline bool unconditional(const struct ip6t_entry *e) 136 { 137 static const struct ip6t_ip6 uncond; 138 139 return e->target_offset == sizeof(struct ip6t_entry) && 140 memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0; 141 } 142 143 static inline const struct xt_entry_target * 144 ip6t_get_target_c(const struct ip6t_entry *e) 145 { 146 return ip6t_get_target((struct ip6t_entry *)e); 147 } 148 149 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 150 /* This cries for unification! */ 151 static const char *const hooknames[] = { 152 [NF_INET_PRE_ROUTING] = "PREROUTING", 153 [NF_INET_LOCAL_IN] = "INPUT", 154 [NF_INET_FORWARD] = "FORWARD", 155 [NF_INET_LOCAL_OUT] = "OUTPUT", 156 [NF_INET_POST_ROUTING] = "POSTROUTING", 157 }; 158 159 enum nf_ip_trace_comments { 160 NF_IP6_TRACE_COMMENT_RULE, 161 NF_IP6_TRACE_COMMENT_RETURN, 162 NF_IP6_TRACE_COMMENT_POLICY, 163 }; 164 165 static const char *const comments[] = { 166 [NF_IP6_TRACE_COMMENT_RULE] = "rule", 167 [NF_IP6_TRACE_COMMENT_RETURN] = "return", 168 [NF_IP6_TRACE_COMMENT_POLICY] = "policy", 169 }; 170 171 static const struct nf_loginfo trace_loginfo = { 172 .type = NF_LOG_TYPE_LOG, 173 .u = { 174 .log = { 175 .level = LOGLEVEL_WARNING, 176 .logflags = NF_LOG_DEFAULT_MASK, 177 }, 178 }, 179 }; 180 181 /* Mildly perf critical (only if packet tracing is on) */ 182 static inline int 183 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e, 184 const char *hookname, const char **chainname, 185 const char **comment, unsigned int *rulenum) 186 { 187 const struct xt_standard_target *t = (void *)ip6t_get_target_c(s); 188 189 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { 190 /* Head of user chain: ERROR target with chainname */ 191 *chainname = t->target.data; 192 (*rulenum) = 0; 193 } else if (s == e) { 194 (*rulenum)++; 195 196 if (unconditional(s) && 197 strcmp(t->target.u.kernel.target->name, 198 XT_STANDARD_TARGET) == 0 && 199 t->verdict < 0) { 200 /* Tail of chains: STANDARD target (return/policy) */ 201 *comment = *chainname == hookname 202 ? comments[NF_IP6_TRACE_COMMENT_POLICY] 203 : comments[NF_IP6_TRACE_COMMENT_RETURN]; 204 } 205 return 1; 206 } else 207 (*rulenum)++; 208 209 return 0; 210 } 211 212 static void trace_packet(struct net *net, 213 const struct sk_buff *skb, 214 unsigned int hook, 215 const struct net_device *in, 216 const struct net_device *out, 217 const char *tablename, 218 const struct xt_table_info *private, 219 const struct ip6t_entry *e) 220 { 221 const struct ip6t_entry *root; 222 const char *hookname, *chainname, *comment; 223 const struct ip6t_entry *iter; 224 unsigned int rulenum = 0; 225 226 root = get_entry(private->entries, private->hook_entry[hook]); 227 228 hookname = chainname = hooknames[hook]; 229 comment = comments[NF_IP6_TRACE_COMMENT_RULE]; 230 231 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) 232 if (get_chainname_rulenum(iter, e, hookname, 233 &chainname, &comment, &rulenum) != 0) 234 break; 235 236 nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo, 237 "TRACE: %s:%s:%s:%u ", 238 tablename, chainname, comment, rulenum); 239 } 240 #endif 241 242 static inline struct ip6t_entry * 243 ip6t_next_entry(const struct ip6t_entry *entry) 244 { 245 return (void *)entry + entry->next_offset; 246 } 247 248 /* Returns one of the generic firewall policies, like NF_ACCEPT. */ 249 unsigned int 250 ip6t_do_table(struct sk_buff *skb, 251 const struct nf_hook_state *state, 252 struct xt_table *table) 253 { 254 unsigned int hook = state->hook; 255 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); 256 /* Initializing verdict to NF_DROP keeps gcc happy. */ 257 unsigned int verdict = NF_DROP; 258 const char *indev, *outdev; 259 const void *table_base; 260 struct ip6t_entry *e, **jumpstack; 261 unsigned int stackidx, cpu; 262 const struct xt_table_info *private; 263 struct xt_action_param acpar; 264 unsigned int addend; 265 266 /* Initialization */ 267 stackidx = 0; 268 indev = state->in ? state->in->name : nulldevname; 269 outdev = state->out ? state->out->name : nulldevname; 270 /* We handle fragments by dealing with the first fragment as 271 * if it was a normal packet. All other fragments are treated 272 * normally, except that they will NEVER match rules that ask 273 * things we don't know, ie. tcp syn flag or ports). If the 274 * rule is also a fragment-specific rule, non-fragments won't 275 * match it. */ 276 acpar.hotdrop = false; 277 acpar.state = state; 278 279 WARN_ON(!(table->valid_hooks & (1 << hook))); 280 281 local_bh_disable(); 282 addend = xt_write_recseq_begin(); 283 private = READ_ONCE(table->private); /* Address dependency. */ 284 cpu = smp_processor_id(); 285 table_base = private->entries; 286 jumpstack = (struct ip6t_entry **)private->jumpstack[cpu]; 287 288 /* Switch to alternate jumpstack if we're being invoked via TEE. 289 * TEE issues XT_CONTINUE verdict on original skb so we must not 290 * clobber the jumpstack. 291 * 292 * For recursion via REJECT or SYNPROXY the stack will be clobbered 293 * but it is no problem since absolute verdict is issued by these. 294 */ 295 if (static_key_false(&xt_tee_enabled)) 296 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated); 297 298 e = get_entry(table_base, private->hook_entry[hook]); 299 300 do { 301 const struct xt_entry_target *t; 302 const struct xt_entry_match *ematch; 303 struct xt_counters *counter; 304 305 WARN_ON(!e); 306 acpar.thoff = 0; 307 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6, 308 &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) { 309 no_match: 310 e = ip6t_next_entry(e); 311 continue; 312 } 313 314 xt_ematch_foreach(ematch, e) { 315 acpar.match = ematch->u.kernel.match; 316 acpar.matchinfo = ematch->data; 317 if (!acpar.match->match(skb, &acpar)) 318 goto no_match; 319 } 320 321 counter = xt_get_this_cpu_counter(&e->counters); 322 ADD_COUNTER(*counter, skb->len, 1); 323 324 t = ip6t_get_target_c(e); 325 WARN_ON(!t->u.kernel.target); 326 327 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 328 /* The packet is traced: log it */ 329 if (unlikely(skb->nf_trace)) 330 trace_packet(state->net, skb, hook, state->in, 331 state->out, table->name, private, e); 332 #endif 333 /* Standard target? */ 334 if (!t->u.kernel.target->target) { 335 int v; 336 337 v = ((struct xt_standard_target *)t)->verdict; 338 if (v < 0) { 339 /* Pop from stack? */ 340 if (v != XT_RETURN) { 341 verdict = (unsigned int)(-v) - 1; 342 break; 343 } 344 if (stackidx == 0) 345 e = get_entry(table_base, 346 private->underflow[hook]); 347 else 348 e = ip6t_next_entry(jumpstack[--stackidx]); 349 continue; 350 } 351 if (table_base + v != ip6t_next_entry(e) && 352 !(e->ipv6.flags & IP6T_F_GOTO)) { 353 if (unlikely(stackidx >= private->stacksize)) { 354 verdict = NF_DROP; 355 break; 356 } 357 jumpstack[stackidx++] = e; 358 } 359 360 e = get_entry(table_base, v); 361 continue; 362 } 363 364 acpar.target = t->u.kernel.target; 365 acpar.targinfo = t->data; 366 367 verdict = t->u.kernel.target->target(skb, &acpar); 368 if (verdict == XT_CONTINUE) 369 e = ip6t_next_entry(e); 370 else 371 /* Verdict */ 372 break; 373 } while (!acpar.hotdrop); 374 375 xt_write_recseq_end(addend); 376 local_bh_enable(); 377 378 if (acpar.hotdrop) 379 return NF_DROP; 380 else return verdict; 381 } 382 383 /* Figures out from what hook each rule can be called: returns 0 if 384 there are loops. Puts hook bitmask in comefrom. */ 385 static int 386 mark_source_chains(const struct xt_table_info *newinfo, 387 unsigned int valid_hooks, void *entry0, 388 unsigned int *offsets) 389 { 390 unsigned int hook; 391 392 /* No recursion; use packet counter to save back ptrs (reset 393 to 0 as we leave), and comefrom to save source hook bitmask */ 394 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { 395 unsigned int pos = newinfo->hook_entry[hook]; 396 struct ip6t_entry *e = entry0 + pos; 397 398 if (!(valid_hooks & (1 << hook))) 399 continue; 400 401 /* Set initial back pointer. */ 402 e->counters.pcnt = pos; 403 404 for (;;) { 405 const struct xt_standard_target *t 406 = (void *)ip6t_get_target_c(e); 407 int visited = e->comefrom & (1 << hook); 408 409 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) 410 return 0; 411 412 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); 413 414 /* Unconditional return/END. */ 415 if ((unconditional(e) && 416 (strcmp(t->target.u.user.name, 417 XT_STANDARD_TARGET) == 0) && 418 t->verdict < 0) || visited) { 419 unsigned int oldpos, size; 420 421 /* Return: backtrack through the last 422 big jump. */ 423 do { 424 e->comefrom ^= (1<<NF_INET_NUMHOOKS); 425 oldpos = pos; 426 pos = e->counters.pcnt; 427 e->counters.pcnt = 0; 428 429 /* We're at the start. */ 430 if (pos == oldpos) 431 goto next; 432 433 e = entry0 + pos; 434 } while (oldpos == pos + e->next_offset); 435 436 /* Move along one */ 437 size = e->next_offset; 438 e = entry0 + pos + size; 439 if (pos + size >= newinfo->size) 440 return 0; 441 e->counters.pcnt = pos; 442 pos += size; 443 } else { 444 int newpos = t->verdict; 445 446 if (strcmp(t->target.u.user.name, 447 XT_STANDARD_TARGET) == 0 && 448 newpos >= 0) { 449 /* This a jump; chase it. */ 450 if (!xt_find_jump_offset(offsets, newpos, 451 newinfo->number)) 452 return 0; 453 } else { 454 /* ... this is a fallthru */ 455 newpos = pos + e->next_offset; 456 if (newpos >= newinfo->size) 457 return 0; 458 } 459 e = entry0 + newpos; 460 e->counters.pcnt = pos; 461 pos = newpos; 462 } 463 } 464 next: ; 465 } 466 return 1; 467 } 468 469 static void cleanup_match(struct xt_entry_match *m, struct net *net) 470 { 471 struct xt_mtdtor_param par; 472 473 par.net = net; 474 par.match = m->u.kernel.match; 475 par.matchinfo = m->data; 476 par.family = NFPROTO_IPV6; 477 if (par.match->destroy != NULL) 478 par.match->destroy(&par); 479 module_put(par.match->me); 480 } 481 482 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 483 { 484 const struct ip6t_ip6 *ipv6 = par->entryinfo; 485 486 par->match = m->u.kernel.match; 487 par->matchinfo = m->data; 488 489 return xt_check_match(par, m->u.match_size - sizeof(*m), 490 ipv6->proto, ipv6->invflags & IP6T_INV_PROTO); 491 } 492 493 static int 494 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 495 { 496 struct xt_match *match; 497 int ret; 498 499 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 500 m->u.user.revision); 501 if (IS_ERR(match)) 502 return PTR_ERR(match); 503 504 m->u.kernel.match = match; 505 506 ret = check_match(m, par); 507 if (ret) 508 goto err; 509 510 return 0; 511 err: 512 module_put(m->u.kernel.match->me); 513 return ret; 514 } 515 516 static int check_target(struct ip6t_entry *e, struct net *net, const char *name) 517 { 518 struct xt_entry_target *t = ip6t_get_target(e); 519 struct xt_tgchk_param par = { 520 .net = net, 521 .table = name, 522 .entryinfo = e, 523 .target = t->u.kernel.target, 524 .targinfo = t->data, 525 .hook_mask = e->comefrom, 526 .family = NFPROTO_IPV6, 527 }; 528 529 return xt_check_target(&par, t->u.target_size - sizeof(*t), 530 e->ipv6.proto, 531 e->ipv6.invflags & IP6T_INV_PROTO); 532 } 533 534 static int 535 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name, 536 unsigned int size, 537 struct xt_percpu_counter_alloc_state *alloc_state) 538 { 539 struct xt_entry_target *t; 540 struct xt_target *target; 541 int ret; 542 unsigned int j; 543 struct xt_mtchk_param mtpar; 544 struct xt_entry_match *ematch; 545 546 if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) 547 return -ENOMEM; 548 549 j = 0; 550 memset(&mtpar, 0, sizeof(mtpar)); 551 mtpar.net = net; 552 mtpar.table = name; 553 mtpar.entryinfo = &e->ipv6; 554 mtpar.hook_mask = e->comefrom; 555 mtpar.family = NFPROTO_IPV6; 556 xt_ematch_foreach(ematch, e) { 557 ret = find_check_match(ematch, &mtpar); 558 if (ret != 0) 559 goto cleanup_matches; 560 ++j; 561 } 562 563 t = ip6t_get_target(e); 564 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 565 t->u.user.revision); 566 if (IS_ERR(target)) { 567 ret = PTR_ERR(target); 568 goto cleanup_matches; 569 } 570 t->u.kernel.target = target; 571 572 ret = check_target(e, net, name); 573 if (ret) 574 goto err; 575 return 0; 576 err: 577 module_put(t->u.kernel.target->me); 578 cleanup_matches: 579 xt_ematch_foreach(ematch, e) { 580 if (j-- == 0) 581 break; 582 cleanup_match(ematch, net); 583 } 584 585 xt_percpu_counter_free(&e->counters); 586 587 return ret; 588 } 589 590 static bool check_underflow(const struct ip6t_entry *e) 591 { 592 const struct xt_entry_target *t; 593 unsigned int verdict; 594 595 if (!unconditional(e)) 596 return false; 597 t = ip6t_get_target_c(e); 598 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 599 return false; 600 verdict = ((struct xt_standard_target *)t)->verdict; 601 verdict = -verdict - 1; 602 return verdict == NF_DROP || verdict == NF_ACCEPT; 603 } 604 605 static int 606 check_entry_size_and_hooks(struct ip6t_entry *e, 607 struct xt_table_info *newinfo, 608 const unsigned char *base, 609 const unsigned char *limit, 610 const unsigned int *hook_entries, 611 const unsigned int *underflows, 612 unsigned int valid_hooks) 613 { 614 unsigned int h; 615 int err; 616 617 if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 || 618 (unsigned char *)e + sizeof(struct ip6t_entry) >= limit || 619 (unsigned char *)e + e->next_offset > limit) 620 return -EINVAL; 621 622 if (e->next_offset 623 < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) 624 return -EINVAL; 625 626 if (!ip6_checkentry(&e->ipv6)) 627 return -EINVAL; 628 629 err = xt_check_entry_offsets(e, e->elems, e->target_offset, 630 e->next_offset); 631 if (err) 632 return err; 633 634 /* Check hooks & underflows */ 635 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 636 if (!(valid_hooks & (1 << h))) 637 continue; 638 if ((unsigned char *)e - base == hook_entries[h]) 639 newinfo->hook_entry[h] = hook_entries[h]; 640 if ((unsigned char *)e - base == underflows[h]) { 641 if (!check_underflow(e)) 642 return -EINVAL; 643 644 newinfo->underflow[h] = underflows[h]; 645 } 646 } 647 648 /* Clear counters and comefrom */ 649 e->counters = ((struct xt_counters) { 0, 0 }); 650 e->comefrom = 0; 651 return 0; 652 } 653 654 static void cleanup_entry(struct ip6t_entry *e, struct net *net) 655 { 656 struct xt_tgdtor_param par; 657 struct xt_entry_target *t; 658 struct xt_entry_match *ematch; 659 660 /* Cleanup all matches */ 661 xt_ematch_foreach(ematch, e) 662 cleanup_match(ematch, net); 663 t = ip6t_get_target(e); 664 665 par.net = net; 666 par.target = t->u.kernel.target; 667 par.targinfo = t->data; 668 par.family = NFPROTO_IPV6; 669 if (par.target->destroy != NULL) 670 par.target->destroy(&par); 671 module_put(par.target->me); 672 xt_percpu_counter_free(&e->counters); 673 } 674 675 /* Checks and translates the user-supplied table segment (held in 676 newinfo) */ 677 static int 678 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, 679 const struct ip6t_replace *repl) 680 { 681 struct xt_percpu_counter_alloc_state alloc_state = { 0 }; 682 struct ip6t_entry *iter; 683 unsigned int *offsets; 684 unsigned int i; 685 int ret = 0; 686 687 newinfo->size = repl->size; 688 newinfo->number = repl->num_entries; 689 690 /* Init all hooks to impossible value. */ 691 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 692 newinfo->hook_entry[i] = 0xFFFFFFFF; 693 newinfo->underflow[i] = 0xFFFFFFFF; 694 } 695 696 offsets = xt_alloc_entry_offsets(newinfo->number); 697 if (!offsets) 698 return -ENOMEM; 699 i = 0; 700 /* Walk through entries, checking offsets. */ 701 xt_entry_foreach(iter, entry0, newinfo->size) { 702 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 703 entry0 + repl->size, 704 repl->hook_entry, 705 repl->underflow, 706 repl->valid_hooks); 707 if (ret != 0) 708 goto out_free; 709 if (i < repl->num_entries) 710 offsets[i] = (void *)iter - entry0; 711 ++i; 712 if (strcmp(ip6t_get_target(iter)->u.user.name, 713 XT_ERROR_TARGET) == 0) 714 ++newinfo->stacksize; 715 } 716 717 ret = -EINVAL; 718 if (i != repl->num_entries) 719 goto out_free; 720 721 ret = xt_check_table_hooks(newinfo, repl->valid_hooks); 722 if (ret) 723 goto out_free; 724 725 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { 726 ret = -ELOOP; 727 goto out_free; 728 } 729 kvfree(offsets); 730 731 /* Finally, each sanity check must pass */ 732 i = 0; 733 xt_entry_foreach(iter, entry0, newinfo->size) { 734 ret = find_check_entry(iter, net, repl->name, repl->size, 735 &alloc_state); 736 if (ret != 0) 737 break; 738 ++i; 739 } 740 741 if (ret != 0) { 742 xt_entry_foreach(iter, entry0, newinfo->size) { 743 if (i-- == 0) 744 break; 745 cleanup_entry(iter, net); 746 } 747 return ret; 748 } 749 750 return ret; 751 out_free: 752 kvfree(offsets); 753 return ret; 754 } 755 756 static void 757 get_counters(const struct xt_table_info *t, 758 struct xt_counters counters[]) 759 { 760 struct ip6t_entry *iter; 761 unsigned int cpu; 762 unsigned int i; 763 764 for_each_possible_cpu(cpu) { 765 seqcount_t *s = &per_cpu(xt_recseq, cpu); 766 767 i = 0; 768 xt_entry_foreach(iter, t->entries, t->size) { 769 struct xt_counters *tmp; 770 u64 bcnt, pcnt; 771 unsigned int start; 772 773 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 774 do { 775 start = read_seqcount_begin(s); 776 bcnt = tmp->bcnt; 777 pcnt = tmp->pcnt; 778 } while (read_seqcount_retry(s, start)); 779 780 ADD_COUNTER(counters[i], bcnt, pcnt); 781 ++i; 782 cond_resched(); 783 } 784 } 785 } 786 787 static void get_old_counters(const struct xt_table_info *t, 788 struct xt_counters counters[]) 789 { 790 struct ip6t_entry *iter; 791 unsigned int cpu, i; 792 793 for_each_possible_cpu(cpu) { 794 i = 0; 795 xt_entry_foreach(iter, t->entries, t->size) { 796 const struct xt_counters *tmp; 797 798 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 799 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); 800 ++i; 801 } 802 cond_resched(); 803 } 804 } 805 806 static struct xt_counters *alloc_counters(const struct xt_table *table) 807 { 808 unsigned int countersize; 809 struct xt_counters *counters; 810 const struct xt_table_info *private = table->private; 811 812 /* We need atomic snapshot of counters: rest doesn't change 813 (other than comefrom, which userspace doesn't care 814 about). */ 815 countersize = sizeof(struct xt_counters) * private->number; 816 counters = vzalloc(countersize); 817 818 if (counters == NULL) 819 return ERR_PTR(-ENOMEM); 820 821 get_counters(private, counters); 822 823 return counters; 824 } 825 826 static int 827 copy_entries_to_user(unsigned int total_size, 828 const struct xt_table *table, 829 void __user *userptr) 830 { 831 unsigned int off, num; 832 const struct ip6t_entry *e; 833 struct xt_counters *counters; 834 const struct xt_table_info *private = table->private; 835 int ret = 0; 836 const void *loc_cpu_entry; 837 838 counters = alloc_counters(table); 839 if (IS_ERR(counters)) 840 return PTR_ERR(counters); 841 842 loc_cpu_entry = private->entries; 843 844 /* FIXME: use iterator macros --RR */ 845 /* ... then go back and fix counters and names */ 846 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 847 unsigned int i; 848 const struct xt_entry_match *m; 849 const struct xt_entry_target *t; 850 851 e = loc_cpu_entry + off; 852 if (copy_to_user(userptr + off, e, sizeof(*e))) { 853 ret = -EFAULT; 854 goto free_counters; 855 } 856 if (copy_to_user(userptr + off 857 + offsetof(struct ip6t_entry, counters), 858 &counters[num], 859 sizeof(counters[num])) != 0) { 860 ret = -EFAULT; 861 goto free_counters; 862 } 863 864 for (i = sizeof(struct ip6t_entry); 865 i < e->target_offset; 866 i += m->u.match_size) { 867 m = (void *)e + i; 868 869 if (xt_match_to_user(m, userptr + off + i)) { 870 ret = -EFAULT; 871 goto free_counters; 872 } 873 } 874 875 t = ip6t_get_target_c(e); 876 if (xt_target_to_user(t, userptr + off + e->target_offset)) { 877 ret = -EFAULT; 878 goto free_counters; 879 } 880 } 881 882 free_counters: 883 vfree(counters); 884 return ret; 885 } 886 887 #ifdef CONFIG_COMPAT 888 static void compat_standard_from_user(void *dst, const void *src) 889 { 890 int v = *(compat_int_t *)src; 891 892 if (v > 0) 893 v += xt_compat_calc_jump(AF_INET6, v); 894 memcpy(dst, &v, sizeof(v)); 895 } 896 897 static int compat_standard_to_user(void __user *dst, const void *src) 898 { 899 compat_int_t cv = *(int *)src; 900 901 if (cv > 0) 902 cv -= xt_compat_calc_jump(AF_INET6, cv); 903 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; 904 } 905 906 static int compat_calc_entry(const struct ip6t_entry *e, 907 const struct xt_table_info *info, 908 const void *base, struct xt_table_info *newinfo) 909 { 910 const struct xt_entry_match *ematch; 911 const struct xt_entry_target *t; 912 unsigned int entry_offset; 913 int off, i, ret; 914 915 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 916 entry_offset = (void *)e - base; 917 xt_ematch_foreach(ematch, e) 918 off += xt_compat_match_offset(ematch->u.kernel.match); 919 t = ip6t_get_target_c(e); 920 off += xt_compat_target_offset(t->u.kernel.target); 921 newinfo->size -= off; 922 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 923 if (ret) 924 return ret; 925 926 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 927 if (info->hook_entry[i] && 928 (e < (struct ip6t_entry *)(base + info->hook_entry[i]))) 929 newinfo->hook_entry[i] -= off; 930 if (info->underflow[i] && 931 (e < (struct ip6t_entry *)(base + info->underflow[i]))) 932 newinfo->underflow[i] -= off; 933 } 934 return 0; 935 } 936 937 static int compat_table_info(const struct xt_table_info *info, 938 struct xt_table_info *newinfo) 939 { 940 struct ip6t_entry *iter; 941 const void *loc_cpu_entry; 942 int ret; 943 944 if (!newinfo || !info) 945 return -EINVAL; 946 947 /* we dont care about newinfo->entries */ 948 memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); 949 newinfo->initial_entries = 0; 950 loc_cpu_entry = info->entries; 951 ret = xt_compat_init_offsets(AF_INET6, info->number); 952 if (ret) 953 return ret; 954 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 955 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 956 if (ret != 0) 957 return ret; 958 } 959 return 0; 960 } 961 #endif 962 963 static int get_info(struct net *net, void __user *user, 964 const int *len, int compat) 965 { 966 char name[XT_TABLE_MAXNAMELEN]; 967 struct xt_table *t; 968 int ret; 969 970 if (*len != sizeof(struct ip6t_getinfo)) 971 return -EINVAL; 972 973 if (copy_from_user(name, user, sizeof(name)) != 0) 974 return -EFAULT; 975 976 name[XT_TABLE_MAXNAMELEN-1] = '\0'; 977 #ifdef CONFIG_COMPAT 978 if (compat) 979 xt_compat_lock(AF_INET6); 980 #endif 981 t = xt_request_find_table_lock(net, AF_INET6, name); 982 if (!IS_ERR(t)) { 983 struct ip6t_getinfo info; 984 const struct xt_table_info *private = t->private; 985 #ifdef CONFIG_COMPAT 986 struct xt_table_info tmp; 987 988 if (compat) { 989 ret = compat_table_info(private, &tmp); 990 xt_compat_flush_offsets(AF_INET6); 991 private = &tmp; 992 } 993 #endif 994 memset(&info, 0, sizeof(info)); 995 info.valid_hooks = t->valid_hooks; 996 memcpy(info.hook_entry, private->hook_entry, 997 sizeof(info.hook_entry)); 998 memcpy(info.underflow, private->underflow, 999 sizeof(info.underflow)); 1000 info.num_entries = private->number; 1001 info.size = private->size; 1002 strcpy(info.name, name); 1003 1004 if (copy_to_user(user, &info, *len) != 0) 1005 ret = -EFAULT; 1006 else 1007 ret = 0; 1008 1009 xt_table_unlock(t); 1010 module_put(t->me); 1011 } else 1012 ret = PTR_ERR(t); 1013 #ifdef CONFIG_COMPAT 1014 if (compat) 1015 xt_compat_unlock(AF_INET6); 1016 #endif 1017 return ret; 1018 } 1019 1020 static int 1021 get_entries(struct net *net, struct ip6t_get_entries __user *uptr, 1022 const int *len) 1023 { 1024 int ret; 1025 struct ip6t_get_entries get; 1026 struct xt_table *t; 1027 1028 if (*len < sizeof(get)) 1029 return -EINVAL; 1030 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1031 return -EFAULT; 1032 if (*len != sizeof(struct ip6t_get_entries) + get.size) 1033 return -EINVAL; 1034 1035 get.name[sizeof(get.name) - 1] = '\0'; 1036 1037 t = xt_find_table_lock(net, AF_INET6, get.name); 1038 if (!IS_ERR(t)) { 1039 struct xt_table_info *private = t->private; 1040 if (get.size == private->size) 1041 ret = copy_entries_to_user(private->size, 1042 t, uptr->entrytable); 1043 else 1044 ret = -EAGAIN; 1045 1046 module_put(t->me); 1047 xt_table_unlock(t); 1048 } else 1049 ret = PTR_ERR(t); 1050 1051 return ret; 1052 } 1053 1054 static int 1055 __do_replace(struct net *net, const char *name, unsigned int valid_hooks, 1056 struct xt_table_info *newinfo, unsigned int num_counters, 1057 void __user *counters_ptr) 1058 { 1059 int ret; 1060 struct xt_table *t; 1061 struct xt_table_info *oldinfo; 1062 struct xt_counters *counters; 1063 struct ip6t_entry *iter; 1064 1065 ret = 0; 1066 counters = xt_counters_alloc(num_counters); 1067 if (!counters) { 1068 ret = -ENOMEM; 1069 goto out; 1070 } 1071 1072 t = xt_request_find_table_lock(net, AF_INET6, name); 1073 if (IS_ERR(t)) { 1074 ret = PTR_ERR(t); 1075 goto free_newinfo_counters_untrans; 1076 } 1077 1078 /* You lied! */ 1079 if (valid_hooks != t->valid_hooks) { 1080 ret = -EINVAL; 1081 goto put_module; 1082 } 1083 1084 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1085 if (!oldinfo) 1086 goto put_module; 1087 1088 /* Update module usage count based on number of rules */ 1089 if ((oldinfo->number > oldinfo->initial_entries) || 1090 (newinfo->number <= oldinfo->initial_entries)) 1091 module_put(t->me); 1092 if ((oldinfo->number > oldinfo->initial_entries) && 1093 (newinfo->number <= oldinfo->initial_entries)) 1094 module_put(t->me); 1095 1096 xt_table_unlock(t); 1097 1098 get_old_counters(oldinfo, counters); 1099 1100 /* Decrease module usage counts and free resource */ 1101 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) 1102 cleanup_entry(iter, net); 1103 1104 xt_free_table_info(oldinfo); 1105 if (copy_to_user(counters_ptr, counters, 1106 sizeof(struct xt_counters) * num_counters) != 0) { 1107 /* Silent error, can't fail, new table is already in place */ 1108 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n"); 1109 } 1110 vfree(counters); 1111 return ret; 1112 1113 put_module: 1114 module_put(t->me); 1115 xt_table_unlock(t); 1116 free_newinfo_counters_untrans: 1117 vfree(counters); 1118 out: 1119 return ret; 1120 } 1121 1122 static int 1123 do_replace(struct net *net, const void __user *user, unsigned int len) 1124 { 1125 int ret; 1126 struct ip6t_replace tmp; 1127 struct xt_table_info *newinfo; 1128 void *loc_cpu_entry; 1129 struct ip6t_entry *iter; 1130 1131 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) 1132 return -EFAULT; 1133 1134 /* overflow check */ 1135 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1136 return -ENOMEM; 1137 if (tmp.num_counters == 0) 1138 return -EINVAL; 1139 1140 tmp.name[sizeof(tmp.name)-1] = 0; 1141 1142 newinfo = xt_alloc_table_info(tmp.size); 1143 if (!newinfo) 1144 return -ENOMEM; 1145 1146 loc_cpu_entry = newinfo->entries; 1147 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), 1148 tmp.size) != 0) { 1149 ret = -EFAULT; 1150 goto free_newinfo; 1151 } 1152 1153 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); 1154 if (ret != 0) 1155 goto free_newinfo; 1156 1157 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1158 tmp.num_counters, tmp.counters); 1159 if (ret) 1160 goto free_newinfo_untrans; 1161 return 0; 1162 1163 free_newinfo_untrans: 1164 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1165 cleanup_entry(iter, net); 1166 free_newinfo: 1167 xt_free_table_info(newinfo); 1168 return ret; 1169 } 1170 1171 static int 1172 do_add_counters(struct net *net, const void __user *user, unsigned int len, 1173 int compat) 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_from_user(user, len, &tmp, compat); 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_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[0]; 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 newinfo->number = compatr->num_entries; 1449 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1450 newinfo->hook_entry[i] = compatr->hook_entry[i]; 1451 newinfo->underflow[i] = compatr->underflow[i]; 1452 } 1453 entry1 = newinfo->entries; 1454 pos = entry1; 1455 size = compatr->size; 1456 xt_entry_foreach(iter0, entry0, compatr->size) 1457 compat_copy_entry_from_user(iter0, &pos, &size, 1458 newinfo, entry1); 1459 1460 /* all module references in entry0 are now gone. */ 1461 xt_compat_flush_offsets(AF_INET6); 1462 xt_compat_unlock(AF_INET6); 1463 1464 memcpy(&repl, compatr, sizeof(*compatr)); 1465 1466 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1467 repl.hook_entry[i] = newinfo->hook_entry[i]; 1468 repl.underflow[i] = newinfo->underflow[i]; 1469 } 1470 1471 repl.num_counters = 0; 1472 repl.counters = NULL; 1473 repl.size = newinfo->size; 1474 ret = translate_table(net, newinfo, entry1, &repl); 1475 if (ret) 1476 goto free_newinfo; 1477 1478 *pinfo = newinfo; 1479 *pentry0 = entry1; 1480 xt_free_table_info(info); 1481 return 0; 1482 1483 free_newinfo: 1484 xt_free_table_info(newinfo); 1485 return ret; 1486 out_unlock: 1487 xt_compat_flush_offsets(AF_INET6); 1488 xt_compat_unlock(AF_INET6); 1489 xt_entry_foreach(iter0, entry0, compatr->size) { 1490 if (j-- == 0) 1491 break; 1492 compat_release_entry(iter0); 1493 } 1494 return ret; 1495 } 1496 1497 static int 1498 compat_do_replace(struct net *net, void __user *user, unsigned int len) 1499 { 1500 int ret; 1501 struct compat_ip6t_replace tmp; 1502 struct xt_table_info *newinfo; 1503 void *loc_cpu_entry; 1504 struct ip6t_entry *iter; 1505 1506 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) 1507 return -EFAULT; 1508 1509 /* overflow check */ 1510 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1511 return -ENOMEM; 1512 if (tmp.num_counters == 0) 1513 return -EINVAL; 1514 1515 tmp.name[sizeof(tmp.name)-1] = 0; 1516 1517 newinfo = xt_alloc_table_info(tmp.size); 1518 if (!newinfo) 1519 return -ENOMEM; 1520 1521 loc_cpu_entry = newinfo->entries; 1522 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), 1523 tmp.size) != 0) { 1524 ret = -EFAULT; 1525 goto free_newinfo; 1526 } 1527 1528 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); 1529 if (ret != 0) 1530 goto free_newinfo; 1531 1532 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1533 tmp.num_counters, compat_ptr(tmp.counters)); 1534 if (ret) 1535 goto free_newinfo_untrans; 1536 return 0; 1537 1538 free_newinfo_untrans: 1539 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1540 cleanup_entry(iter, net); 1541 free_newinfo: 1542 xt_free_table_info(newinfo); 1543 return ret; 1544 } 1545 1546 static int 1547 compat_do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, 1548 unsigned int len) 1549 { 1550 int ret; 1551 1552 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1553 return -EPERM; 1554 1555 switch (cmd) { 1556 case IP6T_SO_SET_REPLACE: 1557 ret = compat_do_replace(sock_net(sk), user, len); 1558 break; 1559 1560 case IP6T_SO_SET_ADD_COUNTERS: 1561 ret = do_add_counters(sock_net(sk), user, len, 1); 1562 break; 1563 1564 default: 1565 ret = -EINVAL; 1566 } 1567 1568 return ret; 1569 } 1570 1571 struct compat_ip6t_get_entries { 1572 char name[XT_TABLE_MAXNAMELEN]; 1573 compat_uint_t size; 1574 struct compat_ip6t_entry entrytable[0]; 1575 }; 1576 1577 static int 1578 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, 1579 void __user *userptr) 1580 { 1581 struct xt_counters *counters; 1582 const struct xt_table_info *private = table->private; 1583 void __user *pos; 1584 unsigned int size; 1585 int ret = 0; 1586 unsigned int i = 0; 1587 struct ip6t_entry *iter; 1588 1589 counters = alloc_counters(table); 1590 if (IS_ERR(counters)) 1591 return PTR_ERR(counters); 1592 1593 pos = userptr; 1594 size = total_size; 1595 xt_entry_foreach(iter, private->entries, total_size) { 1596 ret = compat_copy_entry_to_user(iter, &pos, 1597 &size, counters, i++); 1598 if (ret != 0) 1599 break; 1600 } 1601 1602 vfree(counters); 1603 return ret; 1604 } 1605 1606 static int 1607 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr, 1608 int *len) 1609 { 1610 int ret; 1611 struct compat_ip6t_get_entries get; 1612 struct xt_table *t; 1613 1614 if (*len < sizeof(get)) 1615 return -EINVAL; 1616 1617 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1618 return -EFAULT; 1619 1620 if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) 1621 return -EINVAL; 1622 1623 get.name[sizeof(get.name) - 1] = '\0'; 1624 1625 xt_compat_lock(AF_INET6); 1626 t = xt_find_table_lock(net, AF_INET6, get.name); 1627 if (!IS_ERR(t)) { 1628 const struct xt_table_info *private = t->private; 1629 struct xt_table_info info; 1630 ret = compat_table_info(private, &info); 1631 if (!ret && get.size == info.size) 1632 ret = compat_copy_entries_to_user(private->size, 1633 t, uptr->entrytable); 1634 else if (!ret) 1635 ret = -EAGAIN; 1636 1637 xt_compat_flush_offsets(AF_INET6); 1638 module_put(t->me); 1639 xt_table_unlock(t); 1640 } else 1641 ret = PTR_ERR(t); 1642 1643 xt_compat_unlock(AF_INET6); 1644 return ret; 1645 } 1646 1647 static int do_ip6t_get_ctl(struct sock *, int, void __user *, int *); 1648 1649 static int 1650 compat_do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1651 { 1652 int ret; 1653 1654 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1655 return -EPERM; 1656 1657 switch (cmd) { 1658 case IP6T_SO_GET_INFO: 1659 ret = get_info(sock_net(sk), user, len, 1); 1660 break; 1661 case IP6T_SO_GET_ENTRIES: 1662 ret = compat_get_entries(sock_net(sk), user, len); 1663 break; 1664 default: 1665 ret = do_ip6t_get_ctl(sk, cmd, user, len); 1666 } 1667 return ret; 1668 } 1669 #endif 1670 1671 static int 1672 do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) 1673 { 1674 int ret; 1675 1676 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1677 return -EPERM; 1678 1679 switch (cmd) { 1680 case IP6T_SO_SET_REPLACE: 1681 ret = do_replace(sock_net(sk), user, len); 1682 break; 1683 1684 case IP6T_SO_SET_ADD_COUNTERS: 1685 ret = do_add_counters(sock_net(sk), user, len, 0); 1686 break; 1687 1688 default: 1689 ret = -EINVAL; 1690 } 1691 1692 return ret; 1693 } 1694 1695 static int 1696 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1697 { 1698 int ret; 1699 1700 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1701 return -EPERM; 1702 1703 switch (cmd) { 1704 case IP6T_SO_GET_INFO: 1705 ret = get_info(sock_net(sk), user, len, 0); 1706 break; 1707 1708 case IP6T_SO_GET_ENTRIES: 1709 ret = get_entries(sock_net(sk), user, len); 1710 break; 1711 1712 case IP6T_SO_GET_REVISION_MATCH: 1713 case IP6T_SO_GET_REVISION_TARGET: { 1714 struct xt_get_revision rev; 1715 int target; 1716 1717 if (*len != sizeof(rev)) { 1718 ret = -EINVAL; 1719 break; 1720 } 1721 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1722 ret = -EFAULT; 1723 break; 1724 } 1725 rev.name[sizeof(rev.name)-1] = 0; 1726 1727 if (cmd == IP6T_SO_GET_REVISION_TARGET) 1728 target = 1; 1729 else 1730 target = 0; 1731 1732 try_then_request_module(xt_find_revision(AF_INET6, rev.name, 1733 rev.revision, 1734 target, &ret), 1735 "ip6t_%s", rev.name); 1736 break; 1737 } 1738 1739 default: 1740 ret = -EINVAL; 1741 } 1742 1743 return ret; 1744 } 1745 1746 static void __ip6t_unregister_table(struct net *net, struct xt_table *table) 1747 { 1748 struct xt_table_info *private; 1749 void *loc_cpu_entry; 1750 struct module *table_owner = table->me; 1751 struct ip6t_entry *iter; 1752 1753 private = xt_unregister_table(table); 1754 1755 /* Decrease module usage counts and free resources */ 1756 loc_cpu_entry = private->entries; 1757 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1758 cleanup_entry(iter, net); 1759 if (private->number > private->initial_entries) 1760 module_put(table_owner); 1761 xt_free_table_info(private); 1762 } 1763 1764 int ip6t_register_table(struct net *net, const struct xt_table *table, 1765 const struct ip6t_replace *repl, 1766 const struct nf_hook_ops *ops, 1767 struct xt_table **res) 1768 { 1769 int ret; 1770 struct xt_table_info *newinfo; 1771 struct xt_table_info bootstrap = {0}; 1772 void *loc_cpu_entry; 1773 struct xt_table *new_table; 1774 1775 newinfo = xt_alloc_table_info(repl->size); 1776 if (!newinfo) 1777 return -ENOMEM; 1778 1779 loc_cpu_entry = newinfo->entries; 1780 memcpy(loc_cpu_entry, repl->entries, repl->size); 1781 1782 ret = translate_table(net, newinfo, loc_cpu_entry, repl); 1783 if (ret != 0) 1784 goto out_free; 1785 1786 new_table = xt_register_table(net, table, &bootstrap, newinfo); 1787 if (IS_ERR(new_table)) { 1788 ret = PTR_ERR(new_table); 1789 goto out_free; 1790 } 1791 1792 /* set res now, will see skbs right after nf_register_net_hooks */ 1793 WRITE_ONCE(*res, new_table); 1794 if (!ops) 1795 return 0; 1796 1797 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); 1798 if (ret != 0) { 1799 __ip6t_unregister_table(net, new_table); 1800 *res = NULL; 1801 } 1802 1803 return ret; 1804 1805 out_free: 1806 xt_free_table_info(newinfo); 1807 return ret; 1808 } 1809 1810 void ip6t_unregister_table(struct net *net, struct xt_table *table, 1811 const struct nf_hook_ops *ops) 1812 { 1813 if (ops) 1814 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); 1815 __ip6t_unregister_table(net, table); 1816 } 1817 1818 /* Returns 1 if the type and code is matched by the range, 0 otherwise */ 1819 static inline bool 1820 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, 1821 u_int8_t type, u_int8_t code, 1822 bool invert) 1823 { 1824 return (type == test_type && code >= min_code && code <= max_code) 1825 ^ invert; 1826 } 1827 1828 static bool 1829 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par) 1830 { 1831 const struct icmp6hdr *ic; 1832 struct icmp6hdr _icmph; 1833 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1834 1835 /* Must not be a fragment. */ 1836 if (par->fragoff != 0) 1837 return false; 1838 1839 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); 1840 if (ic == NULL) { 1841 /* We've been asked to examine this packet, and we 1842 * can't. Hence, no choice but to drop. 1843 */ 1844 par->hotdrop = true; 1845 return false; 1846 } 1847 1848 return icmp6_type_code_match(icmpinfo->type, 1849 icmpinfo->code[0], 1850 icmpinfo->code[1], 1851 ic->icmp6_type, ic->icmp6_code, 1852 !!(icmpinfo->invflags&IP6T_ICMP_INV)); 1853 } 1854 1855 /* Called when user tries to insert an entry of this type. */ 1856 static int icmp6_checkentry(const struct xt_mtchk_param *par) 1857 { 1858 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1859 1860 /* Must specify no unknown invflags */ 1861 return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0; 1862 } 1863 1864 /* The built-in targets: standard (NULL) and error. */ 1865 static struct xt_target ip6t_builtin_tg[] __read_mostly = { 1866 { 1867 .name = XT_STANDARD_TARGET, 1868 .targetsize = sizeof(int), 1869 .family = NFPROTO_IPV6, 1870 #ifdef CONFIG_COMPAT 1871 .compatsize = sizeof(compat_int_t), 1872 .compat_from_user = compat_standard_from_user, 1873 .compat_to_user = compat_standard_to_user, 1874 #endif 1875 }, 1876 { 1877 .name = XT_ERROR_TARGET, 1878 .target = ip6t_error, 1879 .targetsize = XT_FUNCTION_MAXNAMELEN, 1880 .family = NFPROTO_IPV6, 1881 }, 1882 }; 1883 1884 static struct nf_sockopt_ops ip6t_sockopts = { 1885 .pf = PF_INET6, 1886 .set_optmin = IP6T_BASE_CTL, 1887 .set_optmax = IP6T_SO_SET_MAX+1, 1888 .set = do_ip6t_set_ctl, 1889 #ifdef CONFIG_COMPAT 1890 .compat_set = compat_do_ip6t_set_ctl, 1891 #endif 1892 .get_optmin = IP6T_BASE_CTL, 1893 .get_optmax = IP6T_SO_GET_MAX+1, 1894 .get = do_ip6t_get_ctl, 1895 #ifdef CONFIG_COMPAT 1896 .compat_get = compat_do_ip6t_get_ctl, 1897 #endif 1898 .owner = THIS_MODULE, 1899 }; 1900 1901 static struct xt_match ip6t_builtin_mt[] __read_mostly = { 1902 { 1903 .name = "icmp6", 1904 .match = icmp6_match, 1905 .matchsize = sizeof(struct ip6t_icmp), 1906 .checkentry = icmp6_checkentry, 1907 .proto = IPPROTO_ICMPV6, 1908 .family = NFPROTO_IPV6, 1909 .me = THIS_MODULE, 1910 }, 1911 }; 1912 1913 static int __net_init ip6_tables_net_init(struct net *net) 1914 { 1915 return xt_proto_init(net, NFPROTO_IPV6); 1916 } 1917 1918 static void __net_exit ip6_tables_net_exit(struct net *net) 1919 { 1920 xt_proto_fini(net, NFPROTO_IPV6); 1921 } 1922 1923 static struct pernet_operations ip6_tables_net_ops = { 1924 .init = ip6_tables_net_init, 1925 .exit = ip6_tables_net_exit, 1926 }; 1927 1928 static int __init ip6_tables_init(void) 1929 { 1930 int ret; 1931 1932 ret = register_pernet_subsys(&ip6_tables_net_ops); 1933 if (ret < 0) 1934 goto err1; 1935 1936 /* No one else will be downing sem now, so we won't sleep */ 1937 ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1938 if (ret < 0) 1939 goto err2; 1940 ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1941 if (ret < 0) 1942 goto err4; 1943 1944 /* Register setsockopt */ 1945 ret = nf_register_sockopt(&ip6t_sockopts); 1946 if (ret < 0) 1947 goto err5; 1948 1949 return 0; 1950 1951 err5: 1952 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1953 err4: 1954 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1955 err2: 1956 unregister_pernet_subsys(&ip6_tables_net_ops); 1957 err1: 1958 return ret; 1959 } 1960 1961 static void __exit ip6_tables_fini(void) 1962 { 1963 nf_unregister_sockopt(&ip6t_sockopts); 1964 1965 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1966 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1967 unregister_pernet_subsys(&ip6_tables_net_ops); 1968 } 1969 1970 EXPORT_SYMBOL(ip6t_register_table); 1971 EXPORT_SYMBOL(ip6t_unregister_table); 1972 EXPORT_SYMBOL(ip6t_do_table); 1973 1974 module_init(ip6_tables_init); 1975 module_exit(ip6_tables_fini); 1976