1 /* 2 * Packet matching code. 3 * 4 * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling 5 * Copyright (C) 2000-2005 Netfilter Core Team <coreteam@netfilter.org> 6 * Copyright (c) 2006-2010 Patrick McHardy <kaber@trash.net> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 15 #include <linux/kernel.h> 16 #include <linux/capability.h> 17 #include <linux/in.h> 18 #include <linux/skbuff.h> 19 #include <linux/kmod.h> 20 #include <linux/vmalloc.h> 21 #include <linux/netdevice.h> 22 #include <linux/module.h> 23 #include <linux/poison.h> 24 #include <linux/icmpv6.h> 25 #include <net/ipv6.h> 26 #include <net/compat.h> 27 #include <linux/uaccess.h> 28 #include <linux/mutex.h> 29 #include <linux/proc_fs.h> 30 #include <linux/err.h> 31 #include <linux/cpumask.h> 32 33 #include <linux/netfilter_ipv6/ip6_tables.h> 34 #include <linux/netfilter/x_tables.h> 35 #include <net/netfilter/nf_log.h> 36 #include "../../netfilter/xt_repldata.h" 37 38 MODULE_LICENSE("GPL"); 39 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 40 MODULE_DESCRIPTION("IPv6 packet filter"); 41 42 void *ip6t_alloc_initial_table(const struct xt_table *info) 43 { 44 return xt_alloc_initial_table(ip6t, IP6T); 45 } 46 EXPORT_SYMBOL_GPL(ip6t_alloc_initial_table); 47 48 /* Returns whether matches rule or not. */ 49 /* Performance critical - called for every packet */ 50 static inline bool 51 ip6_packet_match(const struct sk_buff *skb, 52 const char *indev, 53 const char *outdev, 54 const struct ip6t_ip6 *ip6info, 55 unsigned int *protoff, 56 int *fragoff, bool *hotdrop) 57 { 58 unsigned long ret; 59 const struct ipv6hdr *ipv6 = ipv6_hdr(skb); 60 61 if (NF_INVF(ip6info, IP6T_INV_SRCIP, 62 ipv6_masked_addr_cmp(&ipv6->saddr, &ip6info->smsk, 63 &ip6info->src)) || 64 NF_INVF(ip6info, IP6T_INV_DSTIP, 65 ipv6_masked_addr_cmp(&ipv6->daddr, &ip6info->dmsk, 66 &ip6info->dst))) 67 return false; 68 69 ret = ifname_compare_aligned(indev, ip6info->iniface, ip6info->iniface_mask); 70 71 if (NF_INVF(ip6info, IP6T_INV_VIA_IN, ret != 0)) 72 return false; 73 74 ret = ifname_compare_aligned(outdev, ip6info->outiface, ip6info->outiface_mask); 75 76 if (NF_INVF(ip6info, IP6T_INV_VIA_OUT, ret != 0)) 77 return false; 78 79 /* ... might want to do something with class and flowlabel here ... */ 80 81 /* look for the desired protocol header */ 82 if (ip6info->flags & IP6T_F_PROTO) { 83 int protohdr; 84 unsigned short _frag_off; 85 86 protohdr = ipv6_find_hdr(skb, protoff, -1, &_frag_off, NULL); 87 if (protohdr < 0) { 88 if (_frag_off == 0) 89 *hotdrop = true; 90 return false; 91 } 92 *fragoff = _frag_off; 93 94 if (ip6info->proto == protohdr) { 95 if (ip6info->invflags & IP6T_INV_PROTO) 96 return false; 97 98 return true; 99 } 100 101 /* We need match for the '-p all', too! */ 102 if ((ip6info->proto != 0) && 103 !(ip6info->invflags & IP6T_INV_PROTO)) 104 return false; 105 } 106 return true; 107 } 108 109 /* should be ip6 safe */ 110 static bool 111 ip6_checkentry(const struct ip6t_ip6 *ipv6) 112 { 113 if (ipv6->flags & ~IP6T_F_MASK) 114 return false; 115 if (ipv6->invflags & ~IP6T_INV_MASK) 116 return false; 117 118 return true; 119 } 120 121 static unsigned int 122 ip6t_error(struct sk_buff *skb, const struct xt_action_param *par) 123 { 124 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); 125 126 return NF_DROP; 127 } 128 129 static inline struct ip6t_entry * 130 get_entry(const void *base, unsigned int offset) 131 { 132 return (struct ip6t_entry *)(base + offset); 133 } 134 135 /* All zeroes == unconditional rule. */ 136 /* Mildly perf critical (only if packet tracing is on) */ 137 static inline bool unconditional(const struct ip6t_entry *e) 138 { 139 static const struct ip6t_ip6 uncond; 140 141 return e->target_offset == sizeof(struct ip6t_entry) && 142 memcmp(&e->ipv6, &uncond, sizeof(uncond)) == 0; 143 } 144 145 static inline const struct xt_entry_target * 146 ip6t_get_target_c(const struct ip6t_entry *e) 147 { 148 return ip6t_get_target((struct ip6t_entry *)e); 149 } 150 151 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 152 /* This cries for unification! */ 153 static const char *const hooknames[] = { 154 [NF_INET_PRE_ROUTING] = "PREROUTING", 155 [NF_INET_LOCAL_IN] = "INPUT", 156 [NF_INET_FORWARD] = "FORWARD", 157 [NF_INET_LOCAL_OUT] = "OUTPUT", 158 [NF_INET_POST_ROUTING] = "POSTROUTING", 159 }; 160 161 enum nf_ip_trace_comments { 162 NF_IP6_TRACE_COMMENT_RULE, 163 NF_IP6_TRACE_COMMENT_RETURN, 164 NF_IP6_TRACE_COMMENT_POLICY, 165 }; 166 167 static const char *const comments[] = { 168 [NF_IP6_TRACE_COMMENT_RULE] = "rule", 169 [NF_IP6_TRACE_COMMENT_RETURN] = "return", 170 [NF_IP6_TRACE_COMMENT_POLICY] = "policy", 171 }; 172 173 static const struct nf_loginfo trace_loginfo = { 174 .type = NF_LOG_TYPE_LOG, 175 .u = { 176 .log = { 177 .level = LOGLEVEL_WARNING, 178 .logflags = NF_LOG_DEFAULT_MASK, 179 }, 180 }, 181 }; 182 183 /* Mildly perf critical (only if packet tracing is on) */ 184 static inline int 185 get_chainname_rulenum(const struct ip6t_entry *s, const struct ip6t_entry *e, 186 const char *hookname, const char **chainname, 187 const char **comment, unsigned int *rulenum) 188 { 189 const struct xt_standard_target *t = (void *)ip6t_get_target_c(s); 190 191 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { 192 /* Head of user chain: ERROR target with chainname */ 193 *chainname = t->target.data; 194 (*rulenum) = 0; 195 } else if (s == e) { 196 (*rulenum)++; 197 198 if (unconditional(s) && 199 strcmp(t->target.u.kernel.target->name, 200 XT_STANDARD_TARGET) == 0 && 201 t->verdict < 0) { 202 /* Tail of chains: STANDARD target (return/policy) */ 203 *comment = *chainname == hookname 204 ? comments[NF_IP6_TRACE_COMMENT_POLICY] 205 : comments[NF_IP6_TRACE_COMMENT_RETURN]; 206 } 207 return 1; 208 } else 209 (*rulenum)++; 210 211 return 0; 212 } 213 214 static void trace_packet(struct net *net, 215 const struct sk_buff *skb, 216 unsigned int hook, 217 const struct net_device *in, 218 const struct net_device *out, 219 const char *tablename, 220 const struct xt_table_info *private, 221 const struct ip6t_entry *e) 222 { 223 const struct ip6t_entry *root; 224 const char *hookname, *chainname, *comment; 225 const struct ip6t_entry *iter; 226 unsigned int rulenum = 0; 227 228 root = get_entry(private->entries, private->hook_entry[hook]); 229 230 hookname = chainname = hooknames[hook]; 231 comment = comments[NF_IP6_TRACE_COMMENT_RULE]; 232 233 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) 234 if (get_chainname_rulenum(iter, e, hookname, 235 &chainname, &comment, &rulenum) != 0) 236 break; 237 238 nf_log_trace(net, AF_INET6, hook, skb, in, out, &trace_loginfo, 239 "TRACE: %s:%s:%s:%u ", 240 tablename, chainname, comment, rulenum); 241 } 242 #endif 243 244 static inline struct ip6t_entry * 245 ip6t_next_entry(const struct ip6t_entry *entry) 246 { 247 return (void *)entry + entry->next_offset; 248 } 249 250 /* Returns one of the generic firewall policies, like NF_ACCEPT. */ 251 unsigned int 252 ip6t_do_table(struct sk_buff *skb, 253 const struct nf_hook_state *state, 254 struct xt_table *table) 255 { 256 unsigned int hook = state->hook; 257 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); 258 /* Initializing verdict to NF_DROP keeps gcc happy. */ 259 unsigned int verdict = NF_DROP; 260 const char *indev, *outdev; 261 const void *table_base; 262 struct ip6t_entry *e, **jumpstack; 263 unsigned int stackidx, cpu; 264 const struct xt_table_info *private; 265 struct xt_action_param acpar; 266 unsigned int addend; 267 268 /* Initialization */ 269 stackidx = 0; 270 indev = state->in ? state->in->name : nulldevname; 271 outdev = state->out ? state->out->name : nulldevname; 272 /* We handle fragments by dealing with the first fragment as 273 * if it was a normal packet. All other fragments are treated 274 * normally, except that they will NEVER match rules that ask 275 * things we don't know, ie. tcp syn flag or ports). If the 276 * rule is also a fragment-specific rule, non-fragments won't 277 * match it. */ 278 acpar.hotdrop = false; 279 acpar.state = state; 280 281 WARN_ON(!(table->valid_hooks & (1 << hook))); 282 283 local_bh_disable(); 284 addend = xt_write_recseq_begin(); 285 private = READ_ONCE(table->private); /* Address dependency. */ 286 cpu = smp_processor_id(); 287 table_base = private->entries; 288 jumpstack = (struct ip6t_entry **)private->jumpstack[cpu]; 289 290 /* Switch to alternate jumpstack if we're being invoked via TEE. 291 * TEE issues XT_CONTINUE verdict on original skb so we must not 292 * clobber the jumpstack. 293 * 294 * For recursion via REJECT or SYNPROXY the stack will be clobbered 295 * but it is no problem since absolute verdict is issued by these. 296 */ 297 if (static_key_false(&xt_tee_enabled)) 298 jumpstack += private->stacksize * __this_cpu_read(nf_skb_duplicated); 299 300 e = get_entry(table_base, private->hook_entry[hook]); 301 302 do { 303 const struct xt_entry_target *t; 304 const struct xt_entry_match *ematch; 305 struct xt_counters *counter; 306 307 WARN_ON(!e); 308 acpar.thoff = 0; 309 if (!ip6_packet_match(skb, indev, outdev, &e->ipv6, 310 &acpar.thoff, &acpar.fragoff, &acpar.hotdrop)) { 311 no_match: 312 e = ip6t_next_entry(e); 313 continue; 314 } 315 316 xt_ematch_foreach(ematch, e) { 317 acpar.match = ematch->u.kernel.match; 318 acpar.matchinfo = ematch->data; 319 if (!acpar.match->match(skb, &acpar)) 320 goto no_match; 321 } 322 323 counter = xt_get_this_cpu_counter(&e->counters); 324 ADD_COUNTER(*counter, skb->len, 1); 325 326 t = ip6t_get_target_c(e); 327 WARN_ON(!t->u.kernel.target); 328 329 #if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 330 /* The packet is traced: log it */ 331 if (unlikely(skb->nf_trace)) 332 trace_packet(state->net, skb, hook, state->in, 333 state->out, table->name, private, e); 334 #endif 335 /* Standard target? */ 336 if (!t->u.kernel.target->target) { 337 int v; 338 339 v = ((struct xt_standard_target *)t)->verdict; 340 if (v < 0) { 341 /* Pop from stack? */ 342 if (v != XT_RETURN) { 343 verdict = (unsigned int)(-v) - 1; 344 break; 345 } 346 if (stackidx == 0) 347 e = get_entry(table_base, 348 private->underflow[hook]); 349 else 350 e = ip6t_next_entry(jumpstack[--stackidx]); 351 continue; 352 } 353 if (table_base + v != ip6t_next_entry(e) && 354 !(e->ipv6.flags & IP6T_F_GOTO)) { 355 jumpstack[stackidx++] = e; 356 } 357 358 e = get_entry(table_base, v); 359 continue; 360 } 361 362 acpar.target = t->u.kernel.target; 363 acpar.targinfo = t->data; 364 365 verdict = t->u.kernel.target->target(skb, &acpar); 366 if (verdict == XT_CONTINUE) 367 e = ip6t_next_entry(e); 368 else 369 /* Verdict */ 370 break; 371 } while (!acpar.hotdrop); 372 373 xt_write_recseq_end(addend); 374 local_bh_enable(); 375 376 if (acpar.hotdrop) 377 return NF_DROP; 378 else return verdict; 379 } 380 381 /* Figures out from what hook each rule can be called: returns 0 if 382 there are loops. Puts hook bitmask in comefrom. */ 383 static int 384 mark_source_chains(const struct xt_table_info *newinfo, 385 unsigned int valid_hooks, void *entry0, 386 unsigned int *offsets) 387 { 388 unsigned int hook; 389 390 /* No recursion; use packet counter to save back ptrs (reset 391 to 0 as we leave), and comefrom to save source hook bitmask */ 392 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { 393 unsigned int pos = newinfo->hook_entry[hook]; 394 struct ip6t_entry *e = entry0 + pos; 395 396 if (!(valid_hooks & (1 << hook))) 397 continue; 398 399 /* Set initial back pointer. */ 400 e->counters.pcnt = pos; 401 402 for (;;) { 403 const struct xt_standard_target *t 404 = (void *)ip6t_get_target_c(e); 405 int visited = e->comefrom & (1 << hook); 406 407 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) 408 return 0; 409 410 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); 411 412 /* Unconditional return/END. */ 413 if ((unconditional(e) && 414 (strcmp(t->target.u.user.name, 415 XT_STANDARD_TARGET) == 0) && 416 t->verdict < 0) || visited) { 417 unsigned int oldpos, size; 418 419 if ((strcmp(t->target.u.user.name, 420 XT_STANDARD_TARGET) == 0) && 421 t->verdict < -NF_MAX_VERDICT - 1) 422 return 0; 423 424 /* Return: backtrack through the last 425 big jump. */ 426 do { 427 e->comefrom ^= (1<<NF_INET_NUMHOOKS); 428 oldpos = pos; 429 pos = e->counters.pcnt; 430 e->counters.pcnt = 0; 431 432 /* We're at the start. */ 433 if (pos == oldpos) 434 goto next; 435 436 e = entry0 + pos; 437 } while (oldpos == pos + e->next_offset); 438 439 /* Move along one */ 440 size = e->next_offset; 441 e = entry0 + pos + size; 442 if (pos + size >= newinfo->size) 443 return 0; 444 e->counters.pcnt = pos; 445 pos += size; 446 } else { 447 int newpos = t->verdict; 448 449 if (strcmp(t->target.u.user.name, 450 XT_STANDARD_TARGET) == 0 && 451 newpos >= 0) { 452 /* This a jump; chase it. */ 453 if (!xt_find_jump_offset(offsets, newpos, 454 newinfo->number)) 455 return 0; 456 } else { 457 /* ... this is a fallthru */ 458 newpos = pos + e->next_offset; 459 if (newpos >= newinfo->size) 460 return 0; 461 } 462 e = entry0 + newpos; 463 e->counters.pcnt = pos; 464 pos = newpos; 465 } 466 } 467 next: ; 468 } 469 return 1; 470 } 471 472 static void cleanup_match(struct xt_entry_match *m, struct net *net) 473 { 474 struct xt_mtdtor_param par; 475 476 par.net = net; 477 par.match = m->u.kernel.match; 478 par.matchinfo = m->data; 479 par.family = NFPROTO_IPV6; 480 if (par.match->destroy != NULL) 481 par.match->destroy(&par); 482 module_put(par.match->me); 483 } 484 485 static int check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 486 { 487 const struct ip6t_ip6 *ipv6 = par->entryinfo; 488 489 par->match = m->u.kernel.match; 490 par->matchinfo = m->data; 491 492 return xt_check_match(par, m->u.match_size - sizeof(*m), 493 ipv6->proto, ipv6->invflags & IP6T_INV_PROTO); 494 } 495 496 static int 497 find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 498 { 499 struct xt_match *match; 500 int ret; 501 502 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 503 m->u.user.revision); 504 if (IS_ERR(match)) 505 return PTR_ERR(match); 506 507 m->u.kernel.match = match; 508 509 ret = check_match(m, par); 510 if (ret) 511 goto err; 512 513 return 0; 514 err: 515 module_put(m->u.kernel.match->me); 516 return ret; 517 } 518 519 static int check_target(struct ip6t_entry *e, struct net *net, const char *name) 520 { 521 struct xt_entry_target *t = ip6t_get_target(e); 522 struct xt_tgchk_param par = { 523 .net = net, 524 .table = name, 525 .entryinfo = e, 526 .target = t->u.kernel.target, 527 .targinfo = t->data, 528 .hook_mask = e->comefrom, 529 .family = NFPROTO_IPV6, 530 }; 531 532 t = ip6t_get_target(e); 533 return xt_check_target(&par, t->u.target_size - sizeof(*t), 534 e->ipv6.proto, 535 e->ipv6.invflags & IP6T_INV_PROTO); 536 } 537 538 static int 539 find_check_entry(struct ip6t_entry *e, struct net *net, const char *name, 540 unsigned int size, 541 struct xt_percpu_counter_alloc_state *alloc_state) 542 { 543 struct xt_entry_target *t; 544 struct xt_target *target; 545 int ret; 546 unsigned int j; 547 struct xt_mtchk_param mtpar; 548 struct xt_entry_match *ematch; 549 550 if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) 551 return -ENOMEM; 552 553 j = 0; 554 mtpar.net = net; 555 mtpar.table = name; 556 mtpar.entryinfo = &e->ipv6; 557 mtpar.hook_mask = e->comefrom; 558 mtpar.family = NFPROTO_IPV6; 559 xt_ematch_foreach(ematch, e) { 560 ret = find_check_match(ematch, &mtpar); 561 if (ret != 0) 562 goto cleanup_matches; 563 ++j; 564 } 565 566 t = ip6t_get_target(e); 567 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 568 t->u.user.revision); 569 if (IS_ERR(target)) { 570 ret = PTR_ERR(target); 571 goto cleanup_matches; 572 } 573 t->u.kernel.target = target; 574 575 ret = check_target(e, net, name); 576 if (ret) 577 goto err; 578 return 0; 579 err: 580 module_put(t->u.kernel.target->me); 581 cleanup_matches: 582 xt_ematch_foreach(ematch, e) { 583 if (j-- == 0) 584 break; 585 cleanup_match(ematch, net); 586 } 587 588 xt_percpu_counter_free(&e->counters); 589 590 return ret; 591 } 592 593 static bool check_underflow(const struct ip6t_entry *e) 594 { 595 const struct xt_entry_target *t; 596 unsigned int verdict; 597 598 if (!unconditional(e)) 599 return false; 600 t = ip6t_get_target_c(e); 601 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 602 return false; 603 verdict = ((struct xt_standard_target *)t)->verdict; 604 verdict = -verdict - 1; 605 return verdict == NF_DROP || verdict == NF_ACCEPT; 606 } 607 608 static int 609 check_entry_size_and_hooks(struct ip6t_entry *e, 610 struct xt_table_info *newinfo, 611 const unsigned char *base, 612 const unsigned char *limit, 613 const unsigned int *hook_entries, 614 const unsigned int *underflows, 615 unsigned int valid_hooks) 616 { 617 unsigned int h; 618 int err; 619 620 if ((unsigned long)e % __alignof__(struct ip6t_entry) != 0 || 621 (unsigned char *)e + sizeof(struct ip6t_entry) >= limit || 622 (unsigned char *)e + e->next_offset > limit) 623 return -EINVAL; 624 625 if (e->next_offset 626 < sizeof(struct ip6t_entry) + sizeof(struct xt_entry_target)) 627 return -EINVAL; 628 629 if (!ip6_checkentry(&e->ipv6)) 630 return -EINVAL; 631 632 err = xt_check_entry_offsets(e, e->elems, e->target_offset, 633 e->next_offset); 634 if (err) 635 return err; 636 637 /* Check hooks & underflows */ 638 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 639 if (!(valid_hooks & (1 << h))) 640 continue; 641 if ((unsigned char *)e - base == hook_entries[h]) 642 newinfo->hook_entry[h] = hook_entries[h]; 643 if ((unsigned char *)e - base == underflows[h]) { 644 if (!check_underflow(e)) 645 return -EINVAL; 646 647 newinfo->underflow[h] = underflows[h]; 648 } 649 } 650 651 /* Clear counters and comefrom */ 652 e->counters = ((struct xt_counters) { 0, 0 }); 653 e->comefrom = 0; 654 return 0; 655 } 656 657 static void cleanup_entry(struct ip6t_entry *e, struct net *net) 658 { 659 struct xt_tgdtor_param par; 660 struct xt_entry_target *t; 661 struct xt_entry_match *ematch; 662 663 /* Cleanup all matches */ 664 xt_ematch_foreach(ematch, e) 665 cleanup_match(ematch, net); 666 t = ip6t_get_target(e); 667 668 par.net = net; 669 par.target = t->u.kernel.target; 670 par.targinfo = t->data; 671 par.family = NFPROTO_IPV6; 672 if (par.target->destroy != NULL) 673 par.target->destroy(&par); 674 module_put(par.target->me); 675 xt_percpu_counter_free(&e->counters); 676 } 677 678 /* Checks and translates the user-supplied table segment (held in 679 newinfo) */ 680 static int 681 translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, 682 const struct ip6t_replace *repl) 683 { 684 struct xt_percpu_counter_alloc_state alloc_state = { 0 }; 685 struct ip6t_entry *iter; 686 unsigned int *offsets; 687 unsigned int i; 688 int ret = 0; 689 690 newinfo->size = repl->size; 691 newinfo->number = repl->num_entries; 692 693 /* Init all hooks to impossible value. */ 694 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 695 newinfo->hook_entry[i] = 0xFFFFFFFF; 696 newinfo->underflow[i] = 0xFFFFFFFF; 697 } 698 699 offsets = xt_alloc_entry_offsets(newinfo->number); 700 if (!offsets) 701 return -ENOMEM; 702 i = 0; 703 /* Walk through entries, checking offsets. */ 704 xt_entry_foreach(iter, entry0, newinfo->size) { 705 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 706 entry0 + repl->size, 707 repl->hook_entry, 708 repl->underflow, 709 repl->valid_hooks); 710 if (ret != 0) 711 goto out_free; 712 if (i < repl->num_entries) 713 offsets[i] = (void *)iter - entry0; 714 ++i; 715 if (strcmp(ip6t_get_target(iter)->u.user.name, 716 XT_ERROR_TARGET) == 0) 717 ++newinfo->stacksize; 718 } 719 720 ret = -EINVAL; 721 if (i != repl->num_entries) 722 goto out_free; 723 724 /* Check hooks all assigned */ 725 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 726 /* Only hooks which are valid */ 727 if (!(repl->valid_hooks & (1 << i))) 728 continue; 729 if (newinfo->hook_entry[i] == 0xFFFFFFFF) 730 goto out_free; 731 if (newinfo->underflow[i] == 0xFFFFFFFF) 732 goto out_free; 733 } 734 735 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { 736 ret = -ELOOP; 737 goto out_free; 738 } 739 kvfree(offsets); 740 741 /* Finally, each sanity check must pass */ 742 i = 0; 743 xt_entry_foreach(iter, entry0, newinfo->size) { 744 ret = find_check_entry(iter, net, repl->name, repl->size, 745 &alloc_state); 746 if (ret != 0) 747 break; 748 ++i; 749 } 750 751 if (ret != 0) { 752 xt_entry_foreach(iter, entry0, newinfo->size) { 753 if (i-- == 0) 754 break; 755 cleanup_entry(iter, net); 756 } 757 return ret; 758 } 759 760 return ret; 761 out_free: 762 kvfree(offsets); 763 return ret; 764 } 765 766 static void 767 get_counters(const struct xt_table_info *t, 768 struct xt_counters counters[]) 769 { 770 struct ip6t_entry *iter; 771 unsigned int cpu; 772 unsigned int i; 773 774 for_each_possible_cpu(cpu) { 775 seqcount_t *s = &per_cpu(xt_recseq, cpu); 776 777 i = 0; 778 xt_entry_foreach(iter, t->entries, t->size) { 779 struct xt_counters *tmp; 780 u64 bcnt, pcnt; 781 unsigned int start; 782 783 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 784 do { 785 start = read_seqcount_begin(s); 786 bcnt = tmp->bcnt; 787 pcnt = tmp->pcnt; 788 } while (read_seqcount_retry(s, start)); 789 790 ADD_COUNTER(counters[i], bcnt, pcnt); 791 ++i; 792 cond_resched(); 793 } 794 } 795 } 796 797 static void get_old_counters(const struct xt_table_info *t, 798 struct xt_counters counters[]) 799 { 800 struct ip6t_entry *iter; 801 unsigned int cpu, i; 802 803 for_each_possible_cpu(cpu) { 804 i = 0; 805 xt_entry_foreach(iter, t->entries, t->size) { 806 const struct xt_counters *tmp; 807 808 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 809 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); 810 ++i; 811 } 812 cond_resched(); 813 } 814 } 815 816 static struct xt_counters *alloc_counters(const struct xt_table *table) 817 { 818 unsigned int countersize; 819 struct xt_counters *counters; 820 const struct xt_table_info *private = table->private; 821 822 /* We need atomic snapshot of counters: rest doesn't change 823 (other than comefrom, which userspace doesn't care 824 about). */ 825 countersize = sizeof(struct xt_counters) * private->number; 826 counters = vzalloc(countersize); 827 828 if (counters == NULL) 829 return ERR_PTR(-ENOMEM); 830 831 get_counters(private, counters); 832 833 return counters; 834 } 835 836 static int 837 copy_entries_to_user(unsigned int total_size, 838 const struct xt_table *table, 839 void __user *userptr) 840 { 841 unsigned int off, num; 842 const struct ip6t_entry *e; 843 struct xt_counters *counters; 844 const struct xt_table_info *private = table->private; 845 int ret = 0; 846 const void *loc_cpu_entry; 847 848 counters = alloc_counters(table); 849 if (IS_ERR(counters)) 850 return PTR_ERR(counters); 851 852 loc_cpu_entry = private->entries; 853 854 /* FIXME: use iterator macros --RR */ 855 /* ... then go back and fix counters and names */ 856 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 857 unsigned int i; 858 const struct xt_entry_match *m; 859 const struct xt_entry_target *t; 860 861 e = loc_cpu_entry + off; 862 if (copy_to_user(userptr + off, e, sizeof(*e))) { 863 ret = -EFAULT; 864 goto free_counters; 865 } 866 if (copy_to_user(userptr + off 867 + offsetof(struct ip6t_entry, counters), 868 &counters[num], 869 sizeof(counters[num])) != 0) { 870 ret = -EFAULT; 871 goto free_counters; 872 } 873 874 for (i = sizeof(struct ip6t_entry); 875 i < e->target_offset; 876 i += m->u.match_size) { 877 m = (void *)e + i; 878 879 if (xt_match_to_user(m, userptr + off + i)) { 880 ret = -EFAULT; 881 goto free_counters; 882 } 883 } 884 885 t = ip6t_get_target_c(e); 886 if (xt_target_to_user(t, userptr + off + e->target_offset)) { 887 ret = -EFAULT; 888 goto free_counters; 889 } 890 } 891 892 free_counters: 893 vfree(counters); 894 return ret; 895 } 896 897 #ifdef CONFIG_COMPAT 898 static void compat_standard_from_user(void *dst, const void *src) 899 { 900 int v = *(compat_int_t *)src; 901 902 if (v > 0) 903 v += xt_compat_calc_jump(AF_INET6, v); 904 memcpy(dst, &v, sizeof(v)); 905 } 906 907 static int compat_standard_to_user(void __user *dst, const void *src) 908 { 909 compat_int_t cv = *(int *)src; 910 911 if (cv > 0) 912 cv -= xt_compat_calc_jump(AF_INET6, cv); 913 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; 914 } 915 916 static int compat_calc_entry(const struct ip6t_entry *e, 917 const struct xt_table_info *info, 918 const void *base, struct xt_table_info *newinfo) 919 { 920 const struct xt_entry_match *ematch; 921 const struct xt_entry_target *t; 922 unsigned int entry_offset; 923 int off, i, ret; 924 925 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 926 entry_offset = (void *)e - base; 927 xt_ematch_foreach(ematch, e) 928 off += xt_compat_match_offset(ematch->u.kernel.match); 929 t = ip6t_get_target_c(e); 930 off += xt_compat_target_offset(t->u.kernel.target); 931 newinfo->size -= off; 932 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 933 if (ret) 934 return ret; 935 936 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 937 if (info->hook_entry[i] && 938 (e < (struct ip6t_entry *)(base + info->hook_entry[i]))) 939 newinfo->hook_entry[i] -= off; 940 if (info->underflow[i] && 941 (e < (struct ip6t_entry *)(base + info->underflow[i]))) 942 newinfo->underflow[i] -= off; 943 } 944 return 0; 945 } 946 947 static int compat_table_info(const struct xt_table_info *info, 948 struct xt_table_info *newinfo) 949 { 950 struct ip6t_entry *iter; 951 const void *loc_cpu_entry; 952 int ret; 953 954 if (!newinfo || !info) 955 return -EINVAL; 956 957 /* we dont care about newinfo->entries */ 958 memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); 959 newinfo->initial_entries = 0; 960 loc_cpu_entry = info->entries; 961 xt_compat_init_offsets(AF_INET6, info->number); 962 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 963 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 964 if (ret != 0) 965 return ret; 966 } 967 return 0; 968 } 969 #endif 970 971 static int get_info(struct net *net, void __user *user, 972 const int *len, int compat) 973 { 974 char name[XT_TABLE_MAXNAMELEN]; 975 struct xt_table *t; 976 int ret; 977 978 if (*len != sizeof(struct ip6t_getinfo)) 979 return -EINVAL; 980 981 if (copy_from_user(name, user, sizeof(name)) != 0) 982 return -EFAULT; 983 984 name[XT_TABLE_MAXNAMELEN-1] = '\0'; 985 #ifdef CONFIG_COMPAT 986 if (compat) 987 xt_compat_lock(AF_INET6); 988 #endif 989 t = xt_request_find_table_lock(net, AF_INET6, name); 990 if (!IS_ERR(t)) { 991 struct ip6t_getinfo info; 992 const struct xt_table_info *private = t->private; 993 #ifdef CONFIG_COMPAT 994 struct xt_table_info tmp; 995 996 if (compat) { 997 ret = compat_table_info(private, &tmp); 998 xt_compat_flush_offsets(AF_INET6); 999 private = &tmp; 1000 } 1001 #endif 1002 memset(&info, 0, sizeof(info)); 1003 info.valid_hooks = t->valid_hooks; 1004 memcpy(info.hook_entry, private->hook_entry, 1005 sizeof(info.hook_entry)); 1006 memcpy(info.underflow, private->underflow, 1007 sizeof(info.underflow)); 1008 info.num_entries = private->number; 1009 info.size = private->size; 1010 strcpy(info.name, name); 1011 1012 if (copy_to_user(user, &info, *len) != 0) 1013 ret = -EFAULT; 1014 else 1015 ret = 0; 1016 1017 xt_table_unlock(t); 1018 module_put(t->me); 1019 } else 1020 ret = PTR_ERR(t); 1021 #ifdef CONFIG_COMPAT 1022 if (compat) 1023 xt_compat_unlock(AF_INET6); 1024 #endif 1025 return ret; 1026 } 1027 1028 static int 1029 get_entries(struct net *net, struct ip6t_get_entries __user *uptr, 1030 const int *len) 1031 { 1032 int ret; 1033 struct ip6t_get_entries get; 1034 struct xt_table *t; 1035 1036 if (*len < sizeof(get)) 1037 return -EINVAL; 1038 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1039 return -EFAULT; 1040 if (*len != sizeof(struct ip6t_get_entries) + get.size) 1041 return -EINVAL; 1042 1043 get.name[sizeof(get.name) - 1] = '\0'; 1044 1045 t = xt_find_table_lock(net, AF_INET6, get.name); 1046 if (!IS_ERR(t)) { 1047 struct xt_table_info *private = t->private; 1048 if (get.size == private->size) 1049 ret = copy_entries_to_user(private->size, 1050 t, uptr->entrytable); 1051 else 1052 ret = -EAGAIN; 1053 1054 module_put(t->me); 1055 xt_table_unlock(t); 1056 } else 1057 ret = PTR_ERR(t); 1058 1059 return ret; 1060 } 1061 1062 static int 1063 __do_replace(struct net *net, const char *name, unsigned int valid_hooks, 1064 struct xt_table_info *newinfo, unsigned int num_counters, 1065 void __user *counters_ptr) 1066 { 1067 int ret; 1068 struct xt_table *t; 1069 struct xt_table_info *oldinfo; 1070 struct xt_counters *counters; 1071 struct ip6t_entry *iter; 1072 1073 ret = 0; 1074 counters = vzalloc(num_counters * sizeof(struct xt_counters)); 1075 if (!counters) { 1076 ret = -ENOMEM; 1077 goto out; 1078 } 1079 1080 t = xt_request_find_table_lock(net, AF_INET6, name); 1081 if (IS_ERR(t)) { 1082 ret = PTR_ERR(t); 1083 goto free_newinfo_counters_untrans; 1084 } 1085 1086 /* You lied! */ 1087 if (valid_hooks != t->valid_hooks) { 1088 ret = -EINVAL; 1089 goto put_module; 1090 } 1091 1092 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1093 if (!oldinfo) 1094 goto put_module; 1095 1096 /* Update module usage count based on number of rules */ 1097 if ((oldinfo->number > oldinfo->initial_entries) || 1098 (newinfo->number <= oldinfo->initial_entries)) 1099 module_put(t->me); 1100 if ((oldinfo->number > oldinfo->initial_entries) && 1101 (newinfo->number <= oldinfo->initial_entries)) 1102 module_put(t->me); 1103 1104 get_old_counters(oldinfo, counters); 1105 1106 /* Decrease module usage counts and free resource */ 1107 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) 1108 cleanup_entry(iter, net); 1109 1110 xt_free_table_info(oldinfo); 1111 if (copy_to_user(counters_ptr, counters, 1112 sizeof(struct xt_counters) * num_counters) != 0) { 1113 /* Silent error, can't fail, new table is already in place */ 1114 net_warn_ratelimited("ip6tables: counters copy to user failed while replacing table\n"); 1115 } 1116 vfree(counters); 1117 xt_table_unlock(t); 1118 return ret; 1119 1120 put_module: 1121 module_put(t->me); 1122 xt_table_unlock(t); 1123 free_newinfo_counters_untrans: 1124 vfree(counters); 1125 out: 1126 return ret; 1127 } 1128 1129 static int 1130 do_replace(struct net *net, const void __user *user, unsigned int len) 1131 { 1132 int ret; 1133 struct ip6t_replace tmp; 1134 struct xt_table_info *newinfo; 1135 void *loc_cpu_entry; 1136 struct ip6t_entry *iter; 1137 1138 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) 1139 return -EFAULT; 1140 1141 /* overflow check */ 1142 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1143 return -ENOMEM; 1144 if (tmp.num_counters == 0) 1145 return -EINVAL; 1146 1147 tmp.name[sizeof(tmp.name)-1] = 0; 1148 1149 newinfo = xt_alloc_table_info(tmp.size); 1150 if (!newinfo) 1151 return -ENOMEM; 1152 1153 loc_cpu_entry = newinfo->entries; 1154 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), 1155 tmp.size) != 0) { 1156 ret = -EFAULT; 1157 goto free_newinfo; 1158 } 1159 1160 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); 1161 if (ret != 0) 1162 goto free_newinfo; 1163 1164 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1165 tmp.num_counters, tmp.counters); 1166 if (ret) 1167 goto free_newinfo_untrans; 1168 return 0; 1169 1170 free_newinfo_untrans: 1171 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1172 cleanup_entry(iter, net); 1173 free_newinfo: 1174 xt_free_table_info(newinfo); 1175 return ret; 1176 } 1177 1178 static int 1179 do_add_counters(struct net *net, const void __user *user, unsigned int len, 1180 int compat) 1181 { 1182 unsigned int i; 1183 struct xt_counters_info tmp; 1184 struct xt_counters *paddc; 1185 struct xt_table *t; 1186 const struct xt_table_info *private; 1187 int ret = 0; 1188 struct ip6t_entry *iter; 1189 unsigned int addend; 1190 1191 paddc = xt_copy_counters_from_user(user, len, &tmp, compat); 1192 if (IS_ERR(paddc)) 1193 return PTR_ERR(paddc); 1194 t = xt_find_table_lock(net, AF_INET6, tmp.name); 1195 if (IS_ERR(t)) { 1196 ret = PTR_ERR(t); 1197 goto free; 1198 } 1199 1200 local_bh_disable(); 1201 private = t->private; 1202 if (private->number != tmp.num_counters) { 1203 ret = -EINVAL; 1204 goto unlock_up_free; 1205 } 1206 1207 i = 0; 1208 addend = xt_write_recseq_begin(); 1209 xt_entry_foreach(iter, private->entries, private->size) { 1210 struct xt_counters *tmp; 1211 1212 tmp = xt_get_this_cpu_counter(&iter->counters); 1213 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); 1214 ++i; 1215 } 1216 xt_write_recseq_end(addend); 1217 unlock_up_free: 1218 local_bh_enable(); 1219 xt_table_unlock(t); 1220 module_put(t->me); 1221 free: 1222 vfree(paddc); 1223 1224 return ret; 1225 } 1226 1227 #ifdef CONFIG_COMPAT 1228 struct compat_ip6t_replace { 1229 char name[XT_TABLE_MAXNAMELEN]; 1230 u32 valid_hooks; 1231 u32 num_entries; 1232 u32 size; 1233 u32 hook_entry[NF_INET_NUMHOOKS]; 1234 u32 underflow[NF_INET_NUMHOOKS]; 1235 u32 num_counters; 1236 compat_uptr_t counters; /* struct xt_counters * */ 1237 struct compat_ip6t_entry entries[0]; 1238 }; 1239 1240 static int 1241 compat_copy_entry_to_user(struct ip6t_entry *e, void __user **dstptr, 1242 unsigned int *size, struct xt_counters *counters, 1243 unsigned int i) 1244 { 1245 struct xt_entry_target *t; 1246 struct compat_ip6t_entry __user *ce; 1247 u_int16_t target_offset, next_offset; 1248 compat_uint_t origsize; 1249 const struct xt_entry_match *ematch; 1250 int ret = 0; 1251 1252 origsize = *size; 1253 ce = *dstptr; 1254 if (copy_to_user(ce, e, sizeof(struct ip6t_entry)) != 0 || 1255 copy_to_user(&ce->counters, &counters[i], 1256 sizeof(counters[i])) != 0) 1257 return -EFAULT; 1258 1259 *dstptr += sizeof(struct compat_ip6t_entry); 1260 *size -= sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1261 1262 xt_ematch_foreach(ematch, e) { 1263 ret = xt_compat_match_to_user(ematch, dstptr, size); 1264 if (ret != 0) 1265 return ret; 1266 } 1267 target_offset = e->target_offset - (origsize - *size); 1268 t = ip6t_get_target(e); 1269 ret = xt_compat_target_to_user(t, dstptr, size); 1270 if (ret) 1271 return ret; 1272 next_offset = e->next_offset - (origsize - *size); 1273 if (put_user(target_offset, &ce->target_offset) != 0 || 1274 put_user(next_offset, &ce->next_offset) != 0) 1275 return -EFAULT; 1276 return 0; 1277 } 1278 1279 static int 1280 compat_find_calc_match(struct xt_entry_match *m, 1281 const struct ip6t_ip6 *ipv6, 1282 int *size) 1283 { 1284 struct xt_match *match; 1285 1286 match = xt_request_find_match(NFPROTO_IPV6, m->u.user.name, 1287 m->u.user.revision); 1288 if (IS_ERR(match)) 1289 return PTR_ERR(match); 1290 1291 m->u.kernel.match = match; 1292 *size += xt_compat_match_offset(match); 1293 return 0; 1294 } 1295 1296 static void compat_release_entry(struct compat_ip6t_entry *e) 1297 { 1298 struct xt_entry_target *t; 1299 struct xt_entry_match *ematch; 1300 1301 /* Cleanup all matches */ 1302 xt_ematch_foreach(ematch, e) 1303 module_put(ematch->u.kernel.match->me); 1304 t = compat_ip6t_get_target(e); 1305 module_put(t->u.kernel.target->me); 1306 } 1307 1308 static int 1309 check_compat_entry_size_and_hooks(struct compat_ip6t_entry *e, 1310 struct xt_table_info *newinfo, 1311 unsigned int *size, 1312 const unsigned char *base, 1313 const unsigned char *limit) 1314 { 1315 struct xt_entry_match *ematch; 1316 struct xt_entry_target *t; 1317 struct xt_target *target; 1318 unsigned int entry_offset; 1319 unsigned int j; 1320 int ret, off; 1321 1322 if ((unsigned long)e % __alignof__(struct compat_ip6t_entry) != 0 || 1323 (unsigned char *)e + sizeof(struct compat_ip6t_entry) >= limit || 1324 (unsigned char *)e + e->next_offset > limit) 1325 return -EINVAL; 1326 1327 if (e->next_offset < sizeof(struct compat_ip6t_entry) + 1328 sizeof(struct compat_xt_entry_target)) 1329 return -EINVAL; 1330 1331 if (!ip6_checkentry(&e->ipv6)) 1332 return -EINVAL; 1333 1334 ret = xt_compat_check_entry_offsets(e, e->elems, 1335 e->target_offset, e->next_offset); 1336 if (ret) 1337 return ret; 1338 1339 off = sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1340 entry_offset = (void *)e - (void *)base; 1341 j = 0; 1342 xt_ematch_foreach(ematch, e) { 1343 ret = compat_find_calc_match(ematch, &e->ipv6, &off); 1344 if (ret != 0) 1345 goto release_matches; 1346 ++j; 1347 } 1348 1349 t = compat_ip6t_get_target(e); 1350 target = xt_request_find_target(NFPROTO_IPV6, t->u.user.name, 1351 t->u.user.revision); 1352 if (IS_ERR(target)) { 1353 ret = PTR_ERR(target); 1354 goto release_matches; 1355 } 1356 t->u.kernel.target = target; 1357 1358 off += xt_compat_target_offset(target); 1359 *size += off; 1360 ret = xt_compat_add_offset(AF_INET6, entry_offset, off); 1361 if (ret) 1362 goto out; 1363 1364 return 0; 1365 1366 out: 1367 module_put(t->u.kernel.target->me); 1368 release_matches: 1369 xt_ematch_foreach(ematch, e) { 1370 if (j-- == 0) 1371 break; 1372 module_put(ematch->u.kernel.match->me); 1373 } 1374 return ret; 1375 } 1376 1377 static void 1378 compat_copy_entry_from_user(struct compat_ip6t_entry *e, void **dstptr, 1379 unsigned int *size, 1380 struct xt_table_info *newinfo, unsigned char *base) 1381 { 1382 struct xt_entry_target *t; 1383 struct ip6t_entry *de; 1384 unsigned int origsize; 1385 int h; 1386 struct xt_entry_match *ematch; 1387 1388 origsize = *size; 1389 de = *dstptr; 1390 memcpy(de, e, sizeof(struct ip6t_entry)); 1391 memcpy(&de->counters, &e->counters, sizeof(e->counters)); 1392 1393 *dstptr += sizeof(struct ip6t_entry); 1394 *size += sizeof(struct ip6t_entry) - sizeof(struct compat_ip6t_entry); 1395 1396 xt_ematch_foreach(ematch, e) 1397 xt_compat_match_from_user(ematch, dstptr, size); 1398 1399 de->target_offset = e->target_offset - (origsize - *size); 1400 t = compat_ip6t_get_target(e); 1401 xt_compat_target_from_user(t, dstptr, size); 1402 1403 de->next_offset = e->next_offset - (origsize - *size); 1404 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 1405 if ((unsigned char *)de - base < newinfo->hook_entry[h]) 1406 newinfo->hook_entry[h] -= origsize - *size; 1407 if ((unsigned char *)de - base < newinfo->underflow[h]) 1408 newinfo->underflow[h] -= origsize - *size; 1409 } 1410 } 1411 1412 static int 1413 translate_compat_table(struct net *net, 1414 struct xt_table_info **pinfo, 1415 void **pentry0, 1416 const struct compat_ip6t_replace *compatr) 1417 { 1418 unsigned int i, j; 1419 struct xt_table_info *newinfo, *info; 1420 void *pos, *entry0, *entry1; 1421 struct compat_ip6t_entry *iter0; 1422 struct ip6t_replace repl; 1423 unsigned int size; 1424 int ret = 0; 1425 1426 info = *pinfo; 1427 entry0 = *pentry0; 1428 size = compatr->size; 1429 info->number = compatr->num_entries; 1430 1431 j = 0; 1432 xt_compat_lock(AF_INET6); 1433 xt_compat_init_offsets(AF_INET6, compatr->num_entries); 1434 /* Walk through entries, checking offsets. */ 1435 xt_entry_foreach(iter0, entry0, compatr->size) { 1436 ret = check_compat_entry_size_and_hooks(iter0, info, &size, 1437 entry0, 1438 entry0 + compatr->size); 1439 if (ret != 0) 1440 goto out_unlock; 1441 ++j; 1442 } 1443 1444 ret = -EINVAL; 1445 if (j != compatr->num_entries) 1446 goto out_unlock; 1447 1448 ret = -ENOMEM; 1449 newinfo = xt_alloc_table_info(size); 1450 if (!newinfo) 1451 goto out_unlock; 1452 1453 newinfo->number = compatr->num_entries; 1454 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1455 newinfo->hook_entry[i] = compatr->hook_entry[i]; 1456 newinfo->underflow[i] = compatr->underflow[i]; 1457 } 1458 entry1 = newinfo->entries; 1459 pos = entry1; 1460 size = compatr->size; 1461 xt_entry_foreach(iter0, entry0, compatr->size) 1462 compat_copy_entry_from_user(iter0, &pos, &size, 1463 newinfo, entry1); 1464 1465 /* all module references in entry0 are now gone. */ 1466 xt_compat_flush_offsets(AF_INET6); 1467 xt_compat_unlock(AF_INET6); 1468 1469 memcpy(&repl, compatr, sizeof(*compatr)); 1470 1471 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1472 repl.hook_entry[i] = newinfo->hook_entry[i]; 1473 repl.underflow[i] = newinfo->underflow[i]; 1474 } 1475 1476 repl.num_counters = 0; 1477 repl.counters = NULL; 1478 repl.size = newinfo->size; 1479 ret = translate_table(net, newinfo, entry1, &repl); 1480 if (ret) 1481 goto free_newinfo; 1482 1483 *pinfo = newinfo; 1484 *pentry0 = entry1; 1485 xt_free_table_info(info); 1486 return 0; 1487 1488 free_newinfo: 1489 xt_free_table_info(newinfo); 1490 return ret; 1491 out_unlock: 1492 xt_compat_flush_offsets(AF_INET6); 1493 xt_compat_unlock(AF_INET6); 1494 xt_entry_foreach(iter0, entry0, compatr->size) { 1495 if (j-- == 0) 1496 break; 1497 compat_release_entry(iter0); 1498 } 1499 return ret; 1500 } 1501 1502 static int 1503 compat_do_replace(struct net *net, void __user *user, unsigned int len) 1504 { 1505 int ret; 1506 struct compat_ip6t_replace tmp; 1507 struct xt_table_info *newinfo; 1508 void *loc_cpu_entry; 1509 struct ip6t_entry *iter; 1510 1511 if (copy_from_user(&tmp, user, sizeof(tmp)) != 0) 1512 return -EFAULT; 1513 1514 /* overflow check */ 1515 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1516 return -ENOMEM; 1517 if (tmp.num_counters == 0) 1518 return -EINVAL; 1519 1520 tmp.name[sizeof(tmp.name)-1] = 0; 1521 1522 newinfo = xt_alloc_table_info(tmp.size); 1523 if (!newinfo) 1524 return -ENOMEM; 1525 1526 loc_cpu_entry = newinfo->entries; 1527 if (copy_from_user(loc_cpu_entry, user + sizeof(tmp), 1528 tmp.size) != 0) { 1529 ret = -EFAULT; 1530 goto free_newinfo; 1531 } 1532 1533 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); 1534 if (ret != 0) 1535 goto free_newinfo; 1536 1537 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1538 tmp.num_counters, compat_ptr(tmp.counters)); 1539 if (ret) 1540 goto free_newinfo_untrans; 1541 return 0; 1542 1543 free_newinfo_untrans: 1544 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1545 cleanup_entry(iter, net); 1546 free_newinfo: 1547 xt_free_table_info(newinfo); 1548 return ret; 1549 } 1550 1551 static int 1552 compat_do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, 1553 unsigned int len) 1554 { 1555 int ret; 1556 1557 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1558 return -EPERM; 1559 1560 switch (cmd) { 1561 case IP6T_SO_SET_REPLACE: 1562 ret = compat_do_replace(sock_net(sk), user, len); 1563 break; 1564 1565 case IP6T_SO_SET_ADD_COUNTERS: 1566 ret = do_add_counters(sock_net(sk), user, len, 1); 1567 break; 1568 1569 default: 1570 ret = -EINVAL; 1571 } 1572 1573 return ret; 1574 } 1575 1576 struct compat_ip6t_get_entries { 1577 char name[XT_TABLE_MAXNAMELEN]; 1578 compat_uint_t size; 1579 struct compat_ip6t_entry entrytable[0]; 1580 }; 1581 1582 static int 1583 compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, 1584 void __user *userptr) 1585 { 1586 struct xt_counters *counters; 1587 const struct xt_table_info *private = table->private; 1588 void __user *pos; 1589 unsigned int size; 1590 int ret = 0; 1591 unsigned int i = 0; 1592 struct ip6t_entry *iter; 1593 1594 counters = alloc_counters(table); 1595 if (IS_ERR(counters)) 1596 return PTR_ERR(counters); 1597 1598 pos = userptr; 1599 size = total_size; 1600 xt_entry_foreach(iter, private->entries, total_size) { 1601 ret = compat_copy_entry_to_user(iter, &pos, 1602 &size, counters, i++); 1603 if (ret != 0) 1604 break; 1605 } 1606 1607 vfree(counters); 1608 return ret; 1609 } 1610 1611 static int 1612 compat_get_entries(struct net *net, struct compat_ip6t_get_entries __user *uptr, 1613 int *len) 1614 { 1615 int ret; 1616 struct compat_ip6t_get_entries get; 1617 struct xt_table *t; 1618 1619 if (*len < sizeof(get)) 1620 return -EINVAL; 1621 1622 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1623 return -EFAULT; 1624 1625 if (*len != sizeof(struct compat_ip6t_get_entries) + get.size) 1626 return -EINVAL; 1627 1628 get.name[sizeof(get.name) - 1] = '\0'; 1629 1630 xt_compat_lock(AF_INET6); 1631 t = xt_find_table_lock(net, AF_INET6, get.name); 1632 if (!IS_ERR(t)) { 1633 const struct xt_table_info *private = t->private; 1634 struct xt_table_info info; 1635 ret = compat_table_info(private, &info); 1636 if (!ret && get.size == info.size) 1637 ret = compat_copy_entries_to_user(private->size, 1638 t, uptr->entrytable); 1639 else if (!ret) 1640 ret = -EAGAIN; 1641 1642 xt_compat_flush_offsets(AF_INET6); 1643 module_put(t->me); 1644 xt_table_unlock(t); 1645 } else 1646 ret = PTR_ERR(t); 1647 1648 xt_compat_unlock(AF_INET6); 1649 return ret; 1650 } 1651 1652 static int do_ip6t_get_ctl(struct sock *, int, void __user *, int *); 1653 1654 static int 1655 compat_do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1656 { 1657 int ret; 1658 1659 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1660 return -EPERM; 1661 1662 switch (cmd) { 1663 case IP6T_SO_GET_INFO: 1664 ret = get_info(sock_net(sk), user, len, 1); 1665 break; 1666 case IP6T_SO_GET_ENTRIES: 1667 ret = compat_get_entries(sock_net(sk), user, len); 1668 break; 1669 default: 1670 ret = do_ip6t_get_ctl(sk, cmd, user, len); 1671 } 1672 return ret; 1673 } 1674 #endif 1675 1676 static int 1677 do_ip6t_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) 1678 { 1679 int ret; 1680 1681 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1682 return -EPERM; 1683 1684 switch (cmd) { 1685 case IP6T_SO_SET_REPLACE: 1686 ret = do_replace(sock_net(sk), user, len); 1687 break; 1688 1689 case IP6T_SO_SET_ADD_COUNTERS: 1690 ret = do_add_counters(sock_net(sk), user, len, 0); 1691 break; 1692 1693 default: 1694 ret = -EINVAL; 1695 } 1696 1697 return ret; 1698 } 1699 1700 static int 1701 do_ip6t_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) 1702 { 1703 int ret; 1704 1705 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1706 return -EPERM; 1707 1708 switch (cmd) { 1709 case IP6T_SO_GET_INFO: 1710 ret = get_info(sock_net(sk), user, len, 0); 1711 break; 1712 1713 case IP6T_SO_GET_ENTRIES: 1714 ret = get_entries(sock_net(sk), user, len); 1715 break; 1716 1717 case IP6T_SO_GET_REVISION_MATCH: 1718 case IP6T_SO_GET_REVISION_TARGET: { 1719 struct xt_get_revision rev; 1720 int target; 1721 1722 if (*len != sizeof(rev)) { 1723 ret = -EINVAL; 1724 break; 1725 } 1726 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1727 ret = -EFAULT; 1728 break; 1729 } 1730 rev.name[sizeof(rev.name)-1] = 0; 1731 1732 if (cmd == IP6T_SO_GET_REVISION_TARGET) 1733 target = 1; 1734 else 1735 target = 0; 1736 1737 try_then_request_module(xt_find_revision(AF_INET6, rev.name, 1738 rev.revision, 1739 target, &ret), 1740 "ip6t_%s", rev.name); 1741 break; 1742 } 1743 1744 default: 1745 ret = -EINVAL; 1746 } 1747 1748 return ret; 1749 } 1750 1751 static void __ip6t_unregister_table(struct net *net, struct xt_table *table) 1752 { 1753 struct xt_table_info *private; 1754 void *loc_cpu_entry; 1755 struct module *table_owner = table->me; 1756 struct ip6t_entry *iter; 1757 1758 private = xt_unregister_table(table); 1759 1760 /* Decrease module usage counts and free resources */ 1761 loc_cpu_entry = private->entries; 1762 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1763 cleanup_entry(iter, net); 1764 if (private->number > private->initial_entries) 1765 module_put(table_owner); 1766 xt_free_table_info(private); 1767 } 1768 1769 int ip6t_register_table(struct net *net, const struct xt_table *table, 1770 const struct ip6t_replace *repl, 1771 const struct nf_hook_ops *ops, 1772 struct xt_table **res) 1773 { 1774 int ret; 1775 struct xt_table_info *newinfo; 1776 struct xt_table_info bootstrap = {0}; 1777 void *loc_cpu_entry; 1778 struct xt_table *new_table; 1779 1780 newinfo = xt_alloc_table_info(repl->size); 1781 if (!newinfo) 1782 return -ENOMEM; 1783 1784 loc_cpu_entry = newinfo->entries; 1785 memcpy(loc_cpu_entry, repl->entries, repl->size); 1786 1787 ret = translate_table(net, newinfo, loc_cpu_entry, repl); 1788 if (ret != 0) 1789 goto out_free; 1790 1791 new_table = xt_register_table(net, table, &bootstrap, newinfo); 1792 if (IS_ERR(new_table)) { 1793 ret = PTR_ERR(new_table); 1794 goto out_free; 1795 } 1796 1797 /* set res now, will see skbs right after nf_register_net_hooks */ 1798 WRITE_ONCE(*res, new_table); 1799 1800 ret = nf_register_net_hooks(net, ops, hweight32(table->valid_hooks)); 1801 if (ret != 0) { 1802 __ip6t_unregister_table(net, new_table); 1803 *res = NULL; 1804 } 1805 1806 return ret; 1807 1808 out_free: 1809 xt_free_table_info(newinfo); 1810 return ret; 1811 } 1812 1813 void ip6t_unregister_table(struct net *net, struct xt_table *table, 1814 const struct nf_hook_ops *ops) 1815 { 1816 nf_unregister_net_hooks(net, ops, hweight32(table->valid_hooks)); 1817 __ip6t_unregister_table(net, table); 1818 } 1819 1820 /* Returns 1 if the type and code is matched by the range, 0 otherwise */ 1821 static inline bool 1822 icmp6_type_code_match(u_int8_t test_type, u_int8_t min_code, u_int8_t max_code, 1823 u_int8_t type, u_int8_t code, 1824 bool invert) 1825 { 1826 return (type == test_type && code >= min_code && code <= max_code) 1827 ^ invert; 1828 } 1829 1830 static bool 1831 icmp6_match(const struct sk_buff *skb, struct xt_action_param *par) 1832 { 1833 const struct icmp6hdr *ic; 1834 struct icmp6hdr _icmph; 1835 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1836 1837 /* Must not be a fragment. */ 1838 if (par->fragoff != 0) 1839 return false; 1840 1841 ic = skb_header_pointer(skb, par->thoff, sizeof(_icmph), &_icmph); 1842 if (ic == NULL) { 1843 /* We've been asked to examine this packet, and we 1844 * can't. Hence, no choice but to drop. 1845 */ 1846 par->hotdrop = true; 1847 return false; 1848 } 1849 1850 return icmp6_type_code_match(icmpinfo->type, 1851 icmpinfo->code[0], 1852 icmpinfo->code[1], 1853 ic->icmp6_type, ic->icmp6_code, 1854 !!(icmpinfo->invflags&IP6T_ICMP_INV)); 1855 } 1856 1857 /* Called when user tries to insert an entry of this type. */ 1858 static int icmp6_checkentry(const struct xt_mtchk_param *par) 1859 { 1860 const struct ip6t_icmp *icmpinfo = par->matchinfo; 1861 1862 /* Must specify no unknown invflags */ 1863 return (icmpinfo->invflags & ~IP6T_ICMP_INV) ? -EINVAL : 0; 1864 } 1865 1866 /* The built-in targets: standard (NULL) and error. */ 1867 static struct xt_target ip6t_builtin_tg[] __read_mostly = { 1868 { 1869 .name = XT_STANDARD_TARGET, 1870 .targetsize = sizeof(int), 1871 .family = NFPROTO_IPV6, 1872 #ifdef CONFIG_COMPAT 1873 .compatsize = sizeof(compat_int_t), 1874 .compat_from_user = compat_standard_from_user, 1875 .compat_to_user = compat_standard_to_user, 1876 #endif 1877 }, 1878 { 1879 .name = XT_ERROR_TARGET, 1880 .target = ip6t_error, 1881 .targetsize = XT_FUNCTION_MAXNAMELEN, 1882 .family = NFPROTO_IPV6, 1883 }, 1884 }; 1885 1886 static struct nf_sockopt_ops ip6t_sockopts = { 1887 .pf = PF_INET6, 1888 .set_optmin = IP6T_BASE_CTL, 1889 .set_optmax = IP6T_SO_SET_MAX+1, 1890 .set = do_ip6t_set_ctl, 1891 #ifdef CONFIG_COMPAT 1892 .compat_set = compat_do_ip6t_set_ctl, 1893 #endif 1894 .get_optmin = IP6T_BASE_CTL, 1895 .get_optmax = IP6T_SO_GET_MAX+1, 1896 .get = do_ip6t_get_ctl, 1897 #ifdef CONFIG_COMPAT 1898 .compat_get = compat_do_ip6t_get_ctl, 1899 #endif 1900 .owner = THIS_MODULE, 1901 }; 1902 1903 static struct xt_match ip6t_builtin_mt[] __read_mostly = { 1904 { 1905 .name = "icmp6", 1906 .match = icmp6_match, 1907 .matchsize = sizeof(struct ip6t_icmp), 1908 .checkentry = icmp6_checkentry, 1909 .proto = IPPROTO_ICMPV6, 1910 .family = NFPROTO_IPV6, 1911 }, 1912 }; 1913 1914 static int __net_init ip6_tables_net_init(struct net *net) 1915 { 1916 return xt_proto_init(net, NFPROTO_IPV6); 1917 } 1918 1919 static void __net_exit ip6_tables_net_exit(struct net *net) 1920 { 1921 xt_proto_fini(net, NFPROTO_IPV6); 1922 } 1923 1924 static struct pernet_operations ip6_tables_net_ops = { 1925 .init = ip6_tables_net_init, 1926 .exit = ip6_tables_net_exit, 1927 }; 1928 1929 static int __init ip6_tables_init(void) 1930 { 1931 int ret; 1932 1933 ret = register_pernet_subsys(&ip6_tables_net_ops); 1934 if (ret < 0) 1935 goto err1; 1936 1937 /* No one else will be downing sem now, so we won't sleep */ 1938 ret = xt_register_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1939 if (ret < 0) 1940 goto err2; 1941 ret = xt_register_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1942 if (ret < 0) 1943 goto err4; 1944 1945 /* Register setsockopt */ 1946 ret = nf_register_sockopt(&ip6t_sockopts); 1947 if (ret < 0) 1948 goto err5; 1949 1950 return 0; 1951 1952 err5: 1953 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1954 err4: 1955 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1956 err2: 1957 unregister_pernet_subsys(&ip6_tables_net_ops); 1958 err1: 1959 return ret; 1960 } 1961 1962 static void __exit ip6_tables_fini(void) 1963 { 1964 nf_unregister_sockopt(&ip6t_sockopts); 1965 1966 xt_unregister_matches(ip6t_builtin_mt, ARRAY_SIZE(ip6t_builtin_mt)); 1967 xt_unregister_targets(ip6t_builtin_tg, ARRAY_SIZE(ip6t_builtin_tg)); 1968 unregister_pernet_subsys(&ip6_tables_net_ops); 1969 } 1970 1971 EXPORT_SYMBOL(ip6t_register_table); 1972 EXPORT_SYMBOL(ip6t_unregister_table); 1973 EXPORT_SYMBOL(ip6t_do_table); 1974 1975 module_init(ip6_tables_init); 1976 module_exit(ip6_tables_fini); 1977