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ip_tables.c
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linux-6.19.14/net/ipv4/netfilter/ip_tables.c
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 10#include <linux/cache.h> 11#include <linux/capability.h> 12#include <linux/skbuff.h> 13#include <linux/kmod.h> 14#include <linux/vmalloc.h> 15#include <linux/netdevice.h> 16#include <linux/module.h> 17#include <net/ip.h> 18#include <net/compat.h> 19#include <linux/uaccess.h> 20#include <linux/mutex.h> 21#include <linux/proc_fs.h> 22#include <linux/err.h> 23#include <linux/cpumask.h> 24 25#include <linux/netfilter/x_tables.h> 26#include <linux/netfilter_ipv4/ip_tables.h> 27#include <net/netfilter/nf_log.h> 28#include "../../netfilter/xt_repldata.h" 29 30MODULE_LICENSE("GPL"); 31MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); 32MODULE_DESCRIPTION("IPv4 packet filter"); 33 34void *ipt_alloc_initial_table(const struct xt_table *info) 35{ 36 return xt_alloc_initial_table(ipt, IPT); 37} 38EXPORT_SYMBOL_GPL(ipt_alloc_initial_table); 39 40/* Returns whether matches rule or not. */ 41/* Performance critical - called for every packet */ 42static inline bool 43ip_packet_match(const struct iphdr *ip, 44 const char *indev, 45 const char *outdev, 46 const struct ipt_ip *ipinfo, 47 int isfrag) 48{ 49 unsigned long ret; 50 51 if (NF_INVF(ipinfo, IPT_INV_SRCIP, 52 (ip->saddr & ipinfo->smsk.s_addr) != ipinfo->src.s_addr) || 53 NF_INVF(ipinfo, IPT_INV_DSTIP, 54 (ip->daddr & ipinfo->dmsk.s_addr) != ipinfo->dst.s_addr)) 55 return false; 56 57 ret = ifname_compare_aligned(indev, ipinfo->iniface, ipinfo->iniface_mask); 58 59 if (NF_INVF(ipinfo, IPT_INV_VIA_IN, ret != 0)) 60 return false; 61 62 ret = ifname_compare_aligned(outdev, ipinfo->outiface, ipinfo->outiface_mask); 63 64 if (NF_INVF(ipinfo, IPT_INV_VIA_OUT, ret != 0)) 65 return false; 66 67 /* Check specific protocol */ 68 if (ipinfo->proto && 69 NF_INVF(ipinfo, IPT_INV_PROTO, ip->protocol != ipinfo->proto)) 70 return false; 71 72 /* If we have a fragment rule but the packet is not a fragment 73 * then we return zero */ 74 if (NF_INVF(ipinfo, IPT_INV_FRAG, 75 (ipinfo->flags & IPT_F_FRAG) && !isfrag)) 76 return false; 77 78 return true; 79} 80 81static bool 82ip_checkentry(const struct ipt_ip *ip) 83{ 84 if (ip->flags & ~IPT_F_MASK) 85 return false; 86 if (ip->invflags & ~IPT_INV_MASK) 87 return false; 88 return true; 89} 90 91static unsigned int 92ipt_error(struct sk_buff *skb, const struct xt_action_param *par) 93{ 94 net_info_ratelimited("error: `%s'\n", (const char *)par->targinfo); 95 96 return NF_DROP; 97} 98 99/* Performance critical */ 100static inline struct ipt_entry * 101get_entry(const void *base, unsigned int offset) 102{ 103 return (struct ipt_entry *)(base + offset); 104} 105 106/* All zeroes == unconditional rule. */ 107/* Mildly perf critical (only if packet tracing is on) */ 108static inline bool unconditional(const struct ipt_entry *e) 109{ 110 static const struct ipt_ip uncond; 111 112 return e->target_offset == sizeof(struct ipt_entry) && 113 memcmp(&e->ip, &uncond, sizeof(uncond)) == 0; 114} 115 116/* for const-correctness */ 117static inline const struct xt_entry_target * 118ipt_get_target_c(const struct ipt_entry *e) 119{ 120 return ipt_get_target((struct ipt_entry *)e); 121} 122 123#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 124static const char *const hooknames[] = { 125 [NF_INET_PRE_ROUTING] = "PREROUTING", 126 [NF_INET_LOCAL_IN] = "INPUT", 127 [NF_INET_FORWARD] = "FORWARD", 128 [NF_INET_LOCAL_OUT] = "OUTPUT", 129 [NF_INET_POST_ROUTING] = "POSTROUTING", 130}; 131 132enum nf_ip_trace_comments { 133 NF_IP_TRACE_COMMENT_RULE, 134 NF_IP_TRACE_COMMENT_RETURN, 135 NF_IP_TRACE_COMMENT_POLICY, 136}; 137 138static const char *const comments[] = { 139 [NF_IP_TRACE_COMMENT_RULE] = "rule", 140 [NF_IP_TRACE_COMMENT_RETURN] = "return", 141 [NF_IP_TRACE_COMMENT_POLICY] = "policy", 142}; 143 144static const struct nf_loginfo trace_loginfo = { 145 .type = NF_LOG_TYPE_LOG, 146 .u = { 147 .log = { 148 .level = 4, 149 .logflags = NF_LOG_DEFAULT_MASK, 150 }, 151 }, 152}; 153 154/* Mildly perf critical (only if packet tracing is on) */ 155static inline int 156get_chainname_rulenum(const struct ipt_entry *s, const struct ipt_entry *e, 157 const char *hookname, const char **chainname, 158 const char **comment, unsigned int *rulenum) 159{ 160 const struct xt_standard_target *t = (void *)ipt_get_target_c(s); 161 162 if (strcmp(t->target.u.kernel.target->name, XT_ERROR_TARGET) == 0) { 163 /* Head of user chain: ERROR target with chainname */ 164 *chainname = t->target.data; 165 (*rulenum) = 0; 166 } else if (s == e) { 167 (*rulenum)++; 168 169 if (unconditional(s) && 170 strcmp(t->target.u.kernel.target->name, 171 XT_STANDARD_TARGET) == 0 && 172 t->verdict < 0) { 173 /* Tail of chains: STANDARD target (return/policy) */ 174 *comment = *chainname == hookname 175 ? comments[NF_IP_TRACE_COMMENT_POLICY] 176 : comments[NF_IP_TRACE_COMMENT_RETURN]; 177 } 178 return 1; 179 } else 180 (*rulenum)++; 181 182 return 0; 183} 184 185static void trace_packet(struct net *net, 186 const struct sk_buff *skb, 187 unsigned int hook, 188 const struct net_device *in, 189 const struct net_device *out, 190 const char *tablename, 191 const struct xt_table_info *private, 192 const struct ipt_entry *e) 193{ 194 const struct ipt_entry *root; 195 const char *hookname, *chainname, *comment; 196 const struct ipt_entry *iter; 197 unsigned int rulenum = 0; 198 199 root = get_entry(private->entries, private->hook_entry[hook]); 200 201 hookname = chainname = hooknames[hook]; 202 comment = comments[NF_IP_TRACE_COMMENT_RULE]; 203 204 xt_entry_foreach(iter, root, private->size - private->hook_entry[hook]) 205 if (get_chainname_rulenum(iter, e, hookname, 206 &chainname, &comment, &rulenum) != 0) 207 break; 208 209 nf_log_trace(net, AF_INET, hook, skb, in, out, &trace_loginfo, 210 "TRACE: %s:%s:%s:%u ", 211 tablename, chainname, comment, rulenum); 212} 213#endif 214 215static inline 216struct ipt_entry *ipt_next_entry(const struct ipt_entry *entry) 217{ 218 return (void *)entry + entry->next_offset; 219} 220 221/* Returns one of the generic firewall policies, like NF_ACCEPT. */ 222unsigned int 223ipt_do_table(void *priv, 224 struct sk_buff *skb, 225 const struct nf_hook_state *state) 226{ 227 const struct xt_table *table = priv; 228 unsigned int hook = state->hook; 229 static const char nulldevname[IFNAMSIZ] __attribute__((aligned(sizeof(long)))); 230 const struct iphdr *ip; 231 /* Initializing verdict to NF_DROP keeps gcc happy. */ 232 unsigned int verdict = NF_DROP; 233 const char *indev, *outdev; 234 const void *table_base; 235 struct ipt_entry *e, **jumpstack; 236 unsigned int stackidx, cpu; 237 const struct xt_table_info *private; 238 struct xt_action_param acpar; 239 unsigned int addend; 240 241 /* Initialization */ 242 stackidx = 0; 243 ip = ip_hdr(skb); 244 indev = state->in ? state->in->name : nulldevname; 245 outdev = state->out ? state->out->name : nulldevname; 246 /* We handle fragments by dealing with the first fragment as 247 * if it was a normal packet. All other fragments are treated 248 * normally, except that they will NEVER match rules that ask 249 * things we don't know, ie. tcp syn flag or ports). If the 250 * rule is also a fragment-specific rule, non-fragments won't 251 * match it. */ 252 acpar.fragoff = ntohs(ip->frag_off) & IP_OFFSET; 253 acpar.thoff = ip_hdrlen(skb); 254 acpar.hotdrop = false; 255 acpar.state = state; 256 257 WARN_ON(!(table->valid_hooks & (1 << hook))); 258 local_bh_disable(); 259 addend = xt_write_recseq_begin(); 260 private = READ_ONCE(table->private); /* Address dependency. */ 261 cpu = smp_processor_id(); 262 table_base = private->entries; 263 jumpstack = (struct ipt_entry **)private->jumpstack[cpu]; 264 265 /* Switch to alternate jumpstack if we're being invoked via TEE. 266 * TEE issues XT_CONTINUE verdict on original skb so we must not 267 * clobber the jumpstack. 268 * 269 * For recursion via REJECT or SYNPROXY the stack will be clobbered 270 * but it is no problem since absolute verdict is issued by these. 271 */ 272 if (static_key_false(&xt_tee_enabled)) 273 jumpstack += private->stacksize * current->in_nf_duplicate; 274 275 e = get_entry(table_base, private->hook_entry[hook]); 276 277 do { 278 const struct xt_entry_target *t; 279 const struct xt_entry_match *ematch; 280 struct xt_counters *counter; 281 282 WARN_ON(!e); 283 if (!ip_packet_match(ip, indev, outdev, 284 &e->ip, acpar.fragoff)) { 285 no_match: 286 e = ipt_next_entry(e); 287 continue; 288 } 289 290 xt_ematch_foreach(ematch, e) { 291 acpar.match = ematch->u.kernel.match; 292 acpar.matchinfo = ematch->data; 293 if (!acpar.match->match(skb, &acpar)) 294 goto no_match; 295 } 296 297 counter = xt_get_this_cpu_counter(&e->counters); 298 ADD_COUNTER(*counter, skb->len, 1); 299 300 t = ipt_get_target_c(e); 301 WARN_ON(!t->u.kernel.target); 302 303#if IS_ENABLED(CONFIG_NETFILTER_XT_TARGET_TRACE) 304 /* The packet is traced: log it */ 305 if (unlikely(skb->nf_trace)) 306 trace_packet(state->net, skb, hook, state->in, 307 state->out, table->name, private, e); 308#endif 309 /* Standard target? */ 310 if (!t->u.kernel.target->target) { 311 int v; 312 313 v = ((struct xt_standard_target *)t)->verdict; 314 if (v < 0) { 315 /* Pop from stack? */ 316 if (v != XT_RETURN) { 317 verdict = (unsigned int)(-v) - 1; 318 break; 319 } 320 if (stackidx == 0) { 321 e = get_entry(table_base, 322 private->underflow[hook]); 323 } else { 324 e = jumpstack[--stackidx]; 325 e = ipt_next_entry(e); 326 } 327 continue; 328 } 329 if (table_base + v != ipt_next_entry(e) && 330 !(e->ip.flags & IPT_F_GOTO)) { 331 if (unlikely(stackidx >= private->stacksize)) { 332 verdict = NF_DROP; 333 break; 334 } 335 jumpstack[stackidx++] = e; 336 } 337 338 e = get_entry(table_base, v); 339 continue; 340 } 341 342 acpar.target = t->u.kernel.target; 343 acpar.targinfo = t->data; 344 345 verdict = t->u.kernel.target->target(skb, &acpar); 346 if (verdict == XT_CONTINUE) { 347 /* Target might have changed stuff. */ 348 ip = ip_hdr(skb); 349 e = ipt_next_entry(e); 350 } else { 351 /* Verdict */ 352 break; 353 } 354 } while (!acpar.hotdrop); 355 356 xt_write_recseq_end(addend); 357 local_bh_enable(); 358 359 if (acpar.hotdrop) 360 return NF_DROP; 361 else return verdict; 362} 363 364/* Figures out from what hook each rule can be called: returns 0 if 365 there are loops. Puts hook bitmask in comefrom. */ 366static int 367mark_source_chains(const struct xt_table_info *newinfo, 368 unsigned int valid_hooks, void *entry0, 369 unsigned int *offsets) 370{ 371 unsigned int hook; 372 373 /* No recursion; use packet counter to save back ptrs (reset 374 to 0 as we leave), and comefrom to save source hook bitmask */ 375 for (hook = 0; hook < NF_INET_NUMHOOKS; hook++) { 376 unsigned int pos = newinfo->hook_entry[hook]; 377 struct ipt_entry *e = entry0 + pos; 378 379 if (!(valid_hooks & (1 << hook))) 380 continue; 381 382 /* Set initial back pointer. */ 383 e->counters.pcnt = pos; 384 385 for (;;) { 386 const struct xt_standard_target *t 387 = (void *)ipt_get_target_c(e); 388 int visited = e->comefrom & (1 << hook); 389 390 if (e->comefrom & (1 << NF_INET_NUMHOOKS)) 391 return 0; 392 393 e->comefrom |= ((1 << hook) | (1 << NF_INET_NUMHOOKS)); 394 395 /* Unconditional return/END. */ 396 if ((unconditional(e) && 397 (strcmp(t->target.u.user.name, 398 XT_STANDARD_TARGET) == 0) && 399 t->verdict < 0) || visited) { 400 unsigned int oldpos, size; 401 402 /* Return: backtrack through the last 403 big jump. */ 404 do { 405 e->comefrom ^= (1<<NF_INET_NUMHOOKS); 406 oldpos = pos; 407 pos = e->counters.pcnt; 408 e->counters.pcnt = 0; 409 410 /* We're at the start. */ 411 if (pos == oldpos) 412 goto next; 413 414 e = entry0 + pos; 415 } while (oldpos == pos + e->next_offset); 416 417 /* Move along one */ 418 size = e->next_offset; 419 e = entry0 + pos + size; 420 if (pos + size >= newinfo->size) 421 return 0; 422 e->counters.pcnt = pos; 423 pos += size; 424 } else { 425 int newpos = t->verdict; 426 427 if (strcmp(t->target.u.user.name, 428 XT_STANDARD_TARGET) == 0 && 429 newpos >= 0) { 430 /* This a jump; chase it. */ 431 if (!xt_find_jump_offset(offsets, newpos, 432 newinfo->number)) 433 return 0; 434 } else { 435 /* ... this is a fallthru */ 436 newpos = pos + e->next_offset; 437 if (newpos >= newinfo->size) 438 return 0; 439 } 440 e = entry0 + newpos; 441 e->counters.pcnt = pos; 442 pos = newpos; 443 } 444 } 445next: ; 446 } 447 return 1; 448} 449 450static void cleanup_match(struct xt_entry_match *m, struct net *net) 451{ 452 struct xt_mtdtor_param par; 453 454 par.net = net; 455 par.match = m->u.kernel.match; 456 par.matchinfo = m->data; 457 par.family = NFPROTO_IPV4; 458 if (par.match->destroy != NULL) 459 par.match->destroy(&par); 460 module_put(par.match->me); 461} 462 463static int 464check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 465{ 466 const struct ipt_ip *ip = par->entryinfo; 467 468 par->match = m->u.kernel.match; 469 par->matchinfo = m->data; 470 471 return xt_check_match(par, m->u.match_size - sizeof(*m), 472 ip->proto, ip->invflags & IPT_INV_PROTO); 473} 474 475static int 476find_check_match(struct xt_entry_match *m, struct xt_mtchk_param *par) 477{ 478 struct xt_match *match; 479 int ret; 480 481 match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name, 482 m->u.user.revision); 483 if (IS_ERR(match)) 484 return PTR_ERR(match); 485 m->u.kernel.match = match; 486 487 ret = check_match(m, par); 488 if (ret) 489 goto err; 490 491 return 0; 492err: 493 module_put(m->u.kernel.match->me); 494 return ret; 495} 496 497static int check_target(struct ipt_entry *e, struct net *net, const char *name) 498{ 499 struct xt_entry_target *t = ipt_get_target(e); 500 struct xt_tgchk_param par = { 501 .net = net, 502 .table = name, 503 .entryinfo = e, 504 .target = t->u.kernel.target, 505 .targinfo = t->data, 506 .hook_mask = e->comefrom, 507 .family = NFPROTO_IPV4, 508 }; 509 510 return xt_check_target(&par, t->u.target_size - sizeof(*t), 511 e->ip.proto, e->ip.invflags & IPT_INV_PROTO); 512} 513 514static int 515find_check_entry(struct ipt_entry *e, struct net *net, const char *name, 516 unsigned int size, 517 struct xt_percpu_counter_alloc_state *alloc_state) 518{ 519 struct xt_entry_target *t; 520 struct xt_target *target; 521 int ret; 522 unsigned int j; 523 struct xt_mtchk_param mtpar; 524 struct xt_entry_match *ematch; 525 526 if (!xt_percpu_counter_alloc(alloc_state, &e->counters)) 527 return -ENOMEM; 528 529 j = 0; 530 memset(&mtpar, 0, sizeof(mtpar)); 531 mtpar.net = net; 532 mtpar.table = name; 533 mtpar.entryinfo = &e->ip; 534 mtpar.hook_mask = e->comefrom; 535 mtpar.family = NFPROTO_IPV4; 536 xt_ematch_foreach(ematch, e) { 537 ret = find_check_match(ematch, &mtpar); 538 if (ret != 0) 539 goto cleanup_matches; 540 ++j; 541 } 542 543 t = ipt_get_target(e); 544 target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name, 545 t->u.user.revision); 546 if (IS_ERR(target)) { 547 ret = PTR_ERR(target); 548 goto cleanup_matches; 549 } 550 t->u.kernel.target = target; 551 552 ret = check_target(e, net, name); 553 if (ret) 554 goto err; 555 556 return 0; 557 err: 558 module_put(t->u.kernel.target->me); 559 cleanup_matches: 560 xt_ematch_foreach(ematch, e) { 561 if (j-- == 0) 562 break; 563 cleanup_match(ematch, net); 564 } 565 566 xt_percpu_counter_free(&e->counters); 567 568 return ret; 569} 570 571static bool check_underflow(const struct ipt_entry *e) 572{ 573 const struct xt_entry_target *t; 574 unsigned int verdict; 575 576 if (!unconditional(e)) 577 return false; 578 t = ipt_get_target_c(e); 579 if (strcmp(t->u.user.name, XT_STANDARD_TARGET) != 0) 580 return false; 581 verdict = ((struct xt_standard_target *)t)->verdict; 582 verdict = -verdict - 1; 583 return verdict == NF_DROP || verdict == NF_ACCEPT; 584} 585 586static int 587check_entry_size_and_hooks(struct ipt_entry *e, 588 struct xt_table_info *newinfo, 589 const unsigned char *base, 590 const unsigned char *limit, 591 const unsigned int *hook_entries, 592 const unsigned int *underflows, 593 unsigned int valid_hooks) 594{ 595 unsigned int h; 596 int err; 597 598 if ((unsigned long)e % __alignof__(struct ipt_entry) != 0 || 599 (unsigned char *)e + sizeof(struct ipt_entry) >= limit || 600 (unsigned char *)e + e->next_offset > limit) 601 return -EINVAL; 602 603 if (e->next_offset 604 < sizeof(struct ipt_entry) + sizeof(struct xt_entry_target)) 605 return -EINVAL; 606 607 if (!ip_checkentry(&e->ip)) 608 return -EINVAL; 609 610 err = xt_check_entry_offsets(e, e->elems, e->target_offset, 611 e->next_offset); 612 if (err) 613 return err; 614 615 /* Check hooks & underflows */ 616 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 617 if (!(valid_hooks & (1 << h))) 618 continue; 619 if ((unsigned char *)e - base == hook_entries[h]) 620 newinfo->hook_entry[h] = hook_entries[h]; 621 if ((unsigned char *)e - base == underflows[h]) { 622 if (!check_underflow(e)) 623 return -EINVAL; 624 625 newinfo->underflow[h] = underflows[h]; 626 } 627 } 628 629 /* Clear counters and comefrom */ 630 e->counters = ((struct xt_counters) { 0, 0 }); 631 e->comefrom = 0; 632 return 0; 633} 634 635static void 636cleanup_entry(struct ipt_entry *e, struct net *net) 637{ 638 struct xt_tgdtor_param par; 639 struct xt_entry_target *t; 640 struct xt_entry_match *ematch; 641 642 /* Cleanup all matches */ 643 xt_ematch_foreach(ematch, e) 644 cleanup_match(ematch, net); 645 t = ipt_get_target(e); 646 647 par.net = net; 648 par.target = t->u.kernel.target; 649 par.targinfo = t->data; 650 par.family = NFPROTO_IPV4; 651 if (par.target->destroy != NULL) 652 par.target->destroy(&par); 653 module_put(par.target->me); 654 xt_percpu_counter_free(&e->counters); 655} 656 657/* Checks and translates the user-supplied table segment (held in 658 newinfo) */ 659static int 660translate_table(struct net *net, struct xt_table_info *newinfo, void *entry0, 661 const struct ipt_replace *repl) 662{ 663 struct xt_percpu_counter_alloc_state alloc_state = { 0 }; 664 struct ipt_entry *iter; 665 unsigned int *offsets; 666 unsigned int i; 667 int ret = 0; 668 669 newinfo->size = repl->size; 670 newinfo->number = repl->num_entries; 671 672 /* Init all hooks to impossible value. */ 673 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 674 newinfo->hook_entry[i] = 0xFFFFFFFF; 675 newinfo->underflow[i] = 0xFFFFFFFF; 676 } 677 678 offsets = xt_alloc_entry_offsets(newinfo->number); 679 if (!offsets) 680 return -ENOMEM; 681 i = 0; 682 /* Walk through entries, checking offsets. */ 683 xt_entry_foreach(iter, entry0, newinfo->size) { 684 ret = check_entry_size_and_hooks(iter, newinfo, entry0, 685 entry0 + repl->size, 686 repl->hook_entry, 687 repl->underflow, 688 repl->valid_hooks); 689 if (ret != 0) 690 goto out_free; 691 if (i < repl->num_entries) 692 offsets[i] = (void *)iter - entry0; 693 ++i; 694 if (strcmp(ipt_get_target(iter)->u.user.name, 695 XT_ERROR_TARGET) == 0) 696 ++newinfo->stacksize; 697 } 698 699 ret = -EINVAL; 700 if (i != repl->num_entries) 701 goto out_free; 702 703 ret = xt_check_table_hooks(newinfo, repl->valid_hooks); 704 if (ret) 705 goto out_free; 706 707 if (!mark_source_chains(newinfo, repl->valid_hooks, entry0, offsets)) { 708 ret = -ELOOP; 709 goto out_free; 710 } 711 kvfree(offsets); 712 713 /* Finally, each sanity check must pass */ 714 i = 0; 715 xt_entry_foreach(iter, entry0, newinfo->size) { 716 ret = find_check_entry(iter, net, repl->name, repl->size, 717 &alloc_state); 718 if (ret != 0) 719 break; 720 ++i; 721 } 722 723 if (ret != 0) { 724 xt_entry_foreach(iter, entry0, newinfo->size) { 725 if (i-- == 0) 726 break; 727 cleanup_entry(iter, net); 728 } 729 return ret; 730 } 731 732 return ret; 733 out_free: 734 kvfree(offsets); 735 return ret; 736} 737 738static void 739get_counters(const struct xt_table_info *t, 740 struct xt_counters counters[]) 741{ 742 struct ipt_entry *iter; 743 unsigned int cpu; 744 unsigned int i; 745 746 for_each_possible_cpu(cpu) { 747 seqcount_t *s = &per_cpu(xt_recseq, cpu); 748 749 i = 0; 750 xt_entry_foreach(iter, t->entries, t->size) { 751 struct xt_counters *tmp; 752 u64 bcnt, pcnt; 753 unsigned int start; 754 755 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 756 do { 757 start = read_seqcount_begin(s); 758 bcnt = tmp->bcnt; 759 pcnt = tmp->pcnt; 760 } while (read_seqcount_retry(s, start)); 761 762 ADD_COUNTER(counters[i], bcnt, pcnt); 763 ++i; /* macro does multi eval of i */ 764 cond_resched(); 765 } 766 } 767} 768 769static void get_old_counters(const struct xt_table_info *t, 770 struct xt_counters counters[]) 771{ 772 struct ipt_entry *iter; 773 unsigned int cpu, i; 774 775 for_each_possible_cpu(cpu) { 776 i = 0; 777 xt_entry_foreach(iter, t->entries, t->size) { 778 const struct xt_counters *tmp; 779 780 tmp = xt_get_per_cpu_counter(&iter->counters, cpu); 781 ADD_COUNTER(counters[i], tmp->bcnt, tmp->pcnt); 782 ++i; /* macro does multi eval of i */ 783 } 784 785 cond_resched(); 786 } 787} 788 789static struct xt_counters *alloc_counters(const struct xt_table *table) 790{ 791 unsigned int countersize; 792 struct xt_counters *counters; 793 const struct xt_table_info *private = table->private; 794 795 /* We need atomic snapshot of counters: rest doesn't change 796 (other than comefrom, which userspace doesn't care 797 about). */ 798 countersize = sizeof(struct xt_counters) * private->number; 799 counters = vzalloc(countersize); 800 801 if (counters == NULL) 802 return ERR_PTR(-ENOMEM); 803 804 get_counters(private, counters); 805 806 return counters; 807} 808 809static int 810copy_entries_to_user(unsigned int total_size, 811 const struct xt_table *table, 812 void __user *userptr) 813{ 814 unsigned int off, num; 815 const struct ipt_entry *e; 816 struct xt_counters *counters; 817 const struct xt_table_info *private = table->private; 818 int ret = 0; 819 const void *loc_cpu_entry; 820 821 counters = alloc_counters(table); 822 if (IS_ERR(counters)) 823 return PTR_ERR(counters); 824 825 loc_cpu_entry = private->entries; 826 827 /* FIXME: use iterator macros --RR */ 828 /* ... then go back and fix counters and names */ 829 for (off = 0, num = 0; off < total_size; off += e->next_offset, num++){ 830 unsigned int i; 831 const struct xt_entry_match *m; 832 const struct xt_entry_target *t; 833 834 e = loc_cpu_entry + off; 835 if (copy_to_user(userptr + off, e, sizeof(*e))) { 836 ret = -EFAULT; 837 goto free_counters; 838 } 839 if (copy_to_user(userptr + off 840 + offsetof(struct ipt_entry, counters), 841 &counters[num], 842 sizeof(counters[num])) != 0) { 843 ret = -EFAULT; 844 goto free_counters; 845 } 846 847 for (i = sizeof(struct ipt_entry); 848 i < e->target_offset; 849 i += m->u.match_size) { 850 m = (void *)e + i; 851 852 if (xt_match_to_user(m, userptr + off + i)) { 853 ret = -EFAULT; 854 goto free_counters; 855 } 856 } 857 858 t = ipt_get_target_c(e); 859 if (xt_target_to_user(t, userptr + off + e->target_offset)) { 860 ret = -EFAULT; 861 goto free_counters; 862 } 863 } 864 865 free_counters: 866 vfree(counters); 867 return ret; 868} 869 870#ifdef CONFIG_NETFILTER_XTABLES_COMPAT 871static void compat_standard_from_user(void *dst, const void *src) 872{ 873 int v = *(compat_int_t *)src; 874 875 if (v > 0) 876 v += xt_compat_calc_jump(AF_INET, v); 877 memcpy(dst, &v, sizeof(v)); 878} 879 880static int compat_standard_to_user(void __user *dst, const void *src) 881{ 882 compat_int_t cv = *(int *)src; 883 884 if (cv > 0) 885 cv -= xt_compat_calc_jump(AF_INET, cv); 886 return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; 887} 888 889static int compat_calc_entry(const struct ipt_entry *e, 890 const struct xt_table_info *info, 891 const void *base, struct xt_table_info *newinfo) 892{ 893 const struct xt_entry_match *ematch; 894 const struct xt_entry_target *t; 895 unsigned int entry_offset; 896 int off, i, ret; 897 898 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); 899 entry_offset = (void *)e - base; 900 xt_ematch_foreach(ematch, e) 901 off += xt_compat_match_offset(ematch->u.kernel.match); 902 t = ipt_get_target_c(e); 903 off += xt_compat_target_offset(t->u.kernel.target); 904 newinfo->size -= off; 905 ret = xt_compat_add_offset(AF_INET, entry_offset, off); 906 if (ret) 907 return ret; 908 909 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 910 if (info->hook_entry[i] && 911 (e < (struct ipt_entry *)(base + info->hook_entry[i]))) 912 newinfo->hook_entry[i] -= off; 913 if (info->underflow[i] && 914 (e < (struct ipt_entry *)(base + info->underflow[i]))) 915 newinfo->underflow[i] -= off; 916 } 917 return 0; 918} 919 920static int compat_table_info(const struct xt_table_info *info, 921 struct xt_table_info *newinfo) 922{ 923 struct ipt_entry *iter; 924 const void *loc_cpu_entry; 925 int ret; 926 927 if (!newinfo || !info) 928 return -EINVAL; 929 930 /* we dont care about newinfo->entries */ 931 memcpy(newinfo, info, offsetof(struct xt_table_info, entries)); 932 newinfo->initial_entries = 0; 933 loc_cpu_entry = info->entries; 934 ret = xt_compat_init_offsets(AF_INET, info->number); 935 if (ret) 936 return ret; 937 xt_entry_foreach(iter, loc_cpu_entry, info->size) { 938 ret = compat_calc_entry(iter, info, loc_cpu_entry, newinfo); 939 if (ret != 0) 940 return ret; 941 } 942 return 0; 943} 944#endif 945 946static int get_info(struct net *net, void __user *user, const int *len) 947{ 948 char name[XT_TABLE_MAXNAMELEN]; 949 struct xt_table *t; 950 int ret; 951 952 if (*len != sizeof(struct ipt_getinfo)) 953 return -EINVAL; 954 955 if (copy_from_user(name, user, sizeof(name)) != 0) 956 return -EFAULT; 957 958 name[XT_TABLE_MAXNAMELEN-1] = '\0'; 959#ifdef CONFIG_NETFILTER_XTABLES_COMPAT 960 if (in_compat_syscall()) 961 xt_compat_lock(AF_INET); 962#endif 963 t = xt_request_find_table_lock(net, AF_INET, name); 964 if (!IS_ERR(t)) { 965 struct ipt_getinfo info; 966 const struct xt_table_info *private = t->private; 967#ifdef CONFIG_NETFILTER_XTABLES_COMPAT 968 struct xt_table_info tmp; 969 970 if (in_compat_syscall()) { 971 ret = compat_table_info(private, &tmp); 972 xt_compat_flush_offsets(AF_INET); 973 private = &tmp; 974 } 975#endif 976 memset(&info, 0, sizeof(info)); 977 info.valid_hooks = t->valid_hooks; 978 memcpy(info.hook_entry, private->hook_entry, 979 sizeof(info.hook_entry)); 980 memcpy(info.underflow, private->underflow, 981 sizeof(info.underflow)); 982 info.num_entries = private->number; 983 info.size = private->size; 984 strscpy(info.name, name); 985 986 if (copy_to_user(user, &info, *len) != 0) 987 ret = -EFAULT; 988 else 989 ret = 0; 990 991 xt_table_unlock(t); 992 module_put(t->me); 993 } else 994 ret = PTR_ERR(t); 995#ifdef CONFIG_NETFILTER_XTABLES_COMPAT 996 if (in_compat_syscall()) 997 xt_compat_unlock(AF_INET); 998#endif 999 return ret; 1000} 1001 1002static int 1003get_entries(struct net *net, struct ipt_get_entries __user *uptr, 1004 const int *len) 1005{ 1006 int ret; 1007 struct ipt_get_entries get; 1008 struct xt_table *t; 1009 1010 if (*len < sizeof(get)) 1011 return -EINVAL; 1012 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1013 return -EFAULT; 1014 if (*len != sizeof(struct ipt_get_entries) + get.size) 1015 return -EINVAL; 1016 get.name[sizeof(get.name) - 1] = '\0'; 1017 1018 t = xt_find_table_lock(net, AF_INET, get.name); 1019 if (!IS_ERR(t)) { 1020 const struct xt_table_info *private = t->private; 1021 if (get.size == private->size) 1022 ret = copy_entries_to_user(private->size, 1023 t, uptr->entrytable); 1024 else 1025 ret = -EAGAIN; 1026 1027 module_put(t->me); 1028 xt_table_unlock(t); 1029 } else 1030 ret = PTR_ERR(t); 1031 1032 return ret; 1033} 1034 1035static int 1036__do_replace(struct net *net, const char *name, unsigned int valid_hooks, 1037 struct xt_table_info *newinfo, unsigned int num_counters, 1038 void __user *counters_ptr) 1039{ 1040 int ret; 1041 struct xt_table *t; 1042 struct xt_table_info *oldinfo; 1043 struct xt_counters *counters; 1044 struct ipt_entry *iter; 1045 1046 counters = xt_counters_alloc(num_counters); 1047 if (!counters) { 1048 ret = -ENOMEM; 1049 goto out; 1050 } 1051 1052 t = xt_request_find_table_lock(net, AF_INET, name); 1053 if (IS_ERR(t)) { 1054 ret = PTR_ERR(t); 1055 goto free_newinfo_counters_untrans; 1056 } 1057 1058 /* You lied! */ 1059 if (valid_hooks != t->valid_hooks) { 1060 ret = -EINVAL; 1061 goto put_module; 1062 } 1063 1064 oldinfo = xt_replace_table(t, num_counters, newinfo, &ret); 1065 if (!oldinfo) 1066 goto put_module; 1067 1068 /* Update module usage count based on number of rules */ 1069 if ((oldinfo->number > oldinfo->initial_entries) || 1070 (newinfo->number <= oldinfo->initial_entries)) 1071 module_put(t->me); 1072 if ((oldinfo->number > oldinfo->initial_entries) && 1073 (newinfo->number <= oldinfo->initial_entries)) 1074 module_put(t->me); 1075 1076 xt_table_unlock(t); 1077 1078 get_old_counters(oldinfo, counters); 1079 1080 /* Decrease module usage counts and free resource */ 1081 xt_entry_foreach(iter, oldinfo->entries, oldinfo->size) 1082 cleanup_entry(iter, net); 1083 1084 xt_free_table_info(oldinfo); 1085 if (copy_to_user(counters_ptr, counters, 1086 sizeof(struct xt_counters) * num_counters) != 0) { 1087 /* Silent error, can't fail, new table is already in place */ 1088 net_warn_ratelimited("iptables: counters copy to user failed while replacing table\n"); 1089 } 1090 vfree(counters); 1091 return 0; 1092 1093 put_module: 1094 module_put(t->me); 1095 xt_table_unlock(t); 1096 free_newinfo_counters_untrans: 1097 vfree(counters); 1098 out: 1099 return ret; 1100} 1101 1102static int 1103do_replace(struct net *net, sockptr_t arg, unsigned int len) 1104{ 1105 int ret; 1106 struct ipt_replace tmp; 1107 struct xt_table_info *newinfo; 1108 void *loc_cpu_entry; 1109 struct ipt_entry *iter; 1110 1111 if (len < sizeof(tmp)) 1112 return -EINVAL; 1113 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1114 return -EFAULT; 1115 1116 /* overflow check */ 1117 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1118 return -ENOMEM; 1119 if (tmp.num_counters == 0) 1120 return -EINVAL; 1121 if ((u64)len < (u64)tmp.size + sizeof(tmp)) 1122 return -EINVAL; 1123 1124 tmp.name[sizeof(tmp.name)-1] = 0; 1125 1126 newinfo = xt_alloc_table_info(tmp.size); 1127 if (!newinfo) 1128 return -ENOMEM; 1129 1130 loc_cpu_entry = newinfo->entries; 1131 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1132 tmp.size) != 0) { 1133 ret = -EFAULT; 1134 goto free_newinfo; 1135 } 1136 1137 ret = translate_table(net, newinfo, loc_cpu_entry, &tmp); 1138 if (ret != 0) 1139 goto free_newinfo; 1140 1141 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1142 tmp.num_counters, tmp.counters); 1143 if (ret) 1144 goto free_newinfo_untrans; 1145 return 0; 1146 1147 free_newinfo_untrans: 1148 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1149 cleanup_entry(iter, net); 1150 free_newinfo: 1151 xt_free_table_info(newinfo); 1152 return ret; 1153} 1154 1155static int 1156do_add_counters(struct net *net, sockptr_t arg, unsigned int len) 1157{ 1158 unsigned int i; 1159 struct xt_counters_info tmp; 1160 struct xt_counters *paddc; 1161 struct xt_table *t; 1162 const struct xt_table_info *private; 1163 int ret = 0; 1164 struct ipt_entry *iter; 1165 unsigned int addend; 1166 1167 paddc = xt_copy_counters(arg, len, &tmp); 1168 if (IS_ERR(paddc)) 1169 return PTR_ERR(paddc); 1170 1171 t = xt_find_table_lock(net, AF_INET, tmp.name); 1172 if (IS_ERR(t)) { 1173 ret = PTR_ERR(t); 1174 goto free; 1175 } 1176 1177 local_bh_disable(); 1178 private = t->private; 1179 if (private->number != tmp.num_counters) { 1180 ret = -EINVAL; 1181 goto unlock_up_free; 1182 } 1183 1184 i = 0; 1185 addend = xt_write_recseq_begin(); 1186 xt_entry_foreach(iter, private->entries, private->size) { 1187 struct xt_counters *tmp; 1188 1189 tmp = xt_get_this_cpu_counter(&iter->counters); 1190 ADD_COUNTER(*tmp, paddc[i].bcnt, paddc[i].pcnt); 1191 ++i; 1192 } 1193 xt_write_recseq_end(addend); 1194 unlock_up_free: 1195 local_bh_enable(); 1196 xt_table_unlock(t); 1197 module_put(t->me); 1198 free: 1199 vfree(paddc); 1200 1201 return ret; 1202} 1203 1204#ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1205struct compat_ipt_replace { 1206 char name[XT_TABLE_MAXNAMELEN]; 1207 u32 valid_hooks; 1208 u32 num_entries; 1209 u32 size; 1210 u32 hook_entry[NF_INET_NUMHOOKS]; 1211 u32 underflow[NF_INET_NUMHOOKS]; 1212 u32 num_counters; 1213 compat_uptr_t counters; /* struct xt_counters * */ 1214 struct compat_ipt_entry entries[]; 1215}; 1216 1217static int 1218compat_copy_entry_to_user(struct ipt_entry *e, void __user **dstptr, 1219 unsigned int *size, struct xt_counters *counters, 1220 unsigned int i) 1221{ 1222 struct xt_entry_target *t; 1223 struct compat_ipt_entry __user *ce; 1224 u_int16_t target_offset, next_offset; 1225 compat_uint_t origsize; 1226 const struct xt_entry_match *ematch; 1227 int ret = 0; 1228 1229 origsize = *size; 1230 ce = *dstptr; 1231 if (copy_to_user(ce, e, sizeof(struct ipt_entry)) != 0 || 1232 copy_to_user(&ce->counters, &counters[i], 1233 sizeof(counters[i])) != 0) 1234 return -EFAULT; 1235 1236 *dstptr += sizeof(struct compat_ipt_entry); 1237 *size -= sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); 1238 1239 xt_ematch_foreach(ematch, e) { 1240 ret = xt_compat_match_to_user(ematch, dstptr, size); 1241 if (ret != 0) 1242 return ret; 1243 } 1244 target_offset = e->target_offset - (origsize - *size); 1245 t = ipt_get_target(e); 1246 ret = xt_compat_target_to_user(t, dstptr, size); 1247 if (ret) 1248 return ret; 1249 next_offset = e->next_offset - (origsize - *size); 1250 if (put_user(target_offset, &ce->target_offset) != 0 || 1251 put_user(next_offset, &ce->next_offset) != 0) 1252 return -EFAULT; 1253 return 0; 1254} 1255 1256static int 1257compat_find_calc_match(struct xt_entry_match *m, 1258 const struct ipt_ip *ip, 1259 int *size) 1260{ 1261 struct xt_match *match; 1262 1263 match = xt_request_find_match(NFPROTO_IPV4, m->u.user.name, 1264 m->u.user.revision); 1265 if (IS_ERR(match)) 1266 return PTR_ERR(match); 1267 1268 m->u.kernel.match = match; 1269 *size += xt_compat_match_offset(match); 1270 return 0; 1271} 1272 1273static void compat_release_entry(struct compat_ipt_entry *e) 1274{ 1275 struct xt_entry_target *t; 1276 struct xt_entry_match *ematch; 1277 1278 /* Cleanup all matches */ 1279 xt_ematch_foreach(ematch, e) 1280 module_put(ematch->u.kernel.match->me); 1281 t = compat_ipt_get_target(e); 1282 module_put(t->u.kernel.target->me); 1283} 1284 1285static int 1286check_compat_entry_size_and_hooks(struct compat_ipt_entry *e, 1287 struct xt_table_info *newinfo, 1288 unsigned int *size, 1289 const unsigned char *base, 1290 const unsigned char *limit) 1291{ 1292 struct xt_entry_match *ematch; 1293 struct xt_entry_target *t; 1294 struct xt_target *target; 1295 unsigned int entry_offset; 1296 unsigned int j; 1297 int ret, off; 1298 1299 if ((unsigned long)e % __alignof__(struct compat_ipt_entry) != 0 || 1300 (unsigned char *)e + sizeof(struct compat_ipt_entry) >= limit || 1301 (unsigned char *)e + e->next_offset > limit) 1302 return -EINVAL; 1303 1304 if (e->next_offset < sizeof(struct compat_ipt_entry) + 1305 sizeof(struct compat_xt_entry_target)) 1306 return -EINVAL; 1307 1308 if (!ip_checkentry(&e->ip)) 1309 return -EINVAL; 1310 1311 ret = xt_compat_check_entry_offsets(e, e->elems, 1312 e->target_offset, e->next_offset); 1313 if (ret) 1314 return ret; 1315 1316 off = sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); 1317 entry_offset = (void *)e - (void *)base; 1318 j = 0; 1319 xt_ematch_foreach(ematch, e) { 1320 ret = compat_find_calc_match(ematch, &e->ip, &off); 1321 if (ret != 0) 1322 goto release_matches; 1323 ++j; 1324 } 1325 1326 t = compat_ipt_get_target(e); 1327 target = xt_request_find_target(NFPROTO_IPV4, t->u.user.name, 1328 t->u.user.revision); 1329 if (IS_ERR(target)) { 1330 ret = PTR_ERR(target); 1331 goto release_matches; 1332 } 1333 t->u.kernel.target = target; 1334 1335 off += xt_compat_target_offset(target); 1336 *size += off; 1337 ret = xt_compat_add_offset(AF_INET, entry_offset, off); 1338 if (ret) 1339 goto out; 1340 1341 return 0; 1342 1343out: 1344 module_put(t->u.kernel.target->me); 1345release_matches: 1346 xt_ematch_foreach(ematch, e) { 1347 if (j-- == 0) 1348 break; 1349 module_put(ematch->u.kernel.match->me); 1350 } 1351 return ret; 1352} 1353 1354static void 1355compat_copy_entry_from_user(struct compat_ipt_entry *e, void **dstptr, 1356 unsigned int *size, 1357 struct xt_table_info *newinfo, unsigned char *base) 1358{ 1359 struct xt_entry_target *t; 1360 struct ipt_entry *de; 1361 unsigned int origsize; 1362 int h; 1363 struct xt_entry_match *ematch; 1364 1365 origsize = *size; 1366 de = *dstptr; 1367 memcpy(de, e, sizeof(struct ipt_entry)); 1368 memcpy(&de->counters, &e->counters, sizeof(e->counters)); 1369 1370 *dstptr += sizeof(struct ipt_entry); 1371 *size += sizeof(struct ipt_entry) - sizeof(struct compat_ipt_entry); 1372 1373 xt_ematch_foreach(ematch, e) 1374 xt_compat_match_from_user(ematch, dstptr, size); 1375 1376 de->target_offset = e->target_offset - (origsize - *size); 1377 t = compat_ipt_get_target(e); 1378 xt_compat_target_from_user(t, dstptr, size); 1379 1380 de->next_offset = e->next_offset - (origsize - *size); 1381 1382 for (h = 0; h < NF_INET_NUMHOOKS; h++) { 1383 if ((unsigned char *)de - base < newinfo->hook_entry[h]) 1384 newinfo->hook_entry[h] -= origsize - *size; 1385 if ((unsigned char *)de - base < newinfo->underflow[h]) 1386 newinfo->underflow[h] -= origsize - *size; 1387 } 1388} 1389 1390static int 1391translate_compat_table(struct net *net, 1392 struct xt_table_info **pinfo, 1393 void **pentry0, 1394 const struct compat_ipt_replace *compatr) 1395{ 1396 unsigned int i, j; 1397 struct xt_table_info *newinfo, *info; 1398 void *pos, *entry0, *entry1; 1399 struct compat_ipt_entry *iter0; 1400 struct ipt_replace repl; 1401 unsigned int size; 1402 int ret; 1403 1404 info = *pinfo; 1405 entry0 = *pentry0; 1406 size = compatr->size; 1407 info->number = compatr->num_entries; 1408 1409 j = 0; 1410 xt_compat_lock(AF_INET); 1411 ret = xt_compat_init_offsets(AF_INET, compatr->num_entries); 1412 if (ret) 1413 goto out_unlock; 1414 /* Walk through entries, checking offsets. */ 1415 xt_entry_foreach(iter0, entry0, compatr->size) { 1416 ret = check_compat_entry_size_and_hooks(iter0, info, &size, 1417 entry0, 1418 entry0 + compatr->size); 1419 if (ret != 0) 1420 goto out_unlock; 1421 ++j; 1422 } 1423 1424 ret = -EINVAL; 1425 if (j != compatr->num_entries) 1426 goto out_unlock; 1427 1428 ret = -ENOMEM; 1429 newinfo = xt_alloc_table_info(size); 1430 if (!newinfo) 1431 goto out_unlock; 1432 1433 memset(newinfo->entries, 0, size); 1434 1435 newinfo->number = compatr->num_entries; 1436 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1437 newinfo->hook_entry[i] = compatr->hook_entry[i]; 1438 newinfo->underflow[i] = compatr->underflow[i]; 1439 } 1440 entry1 = newinfo->entries; 1441 pos = entry1; 1442 size = compatr->size; 1443 xt_entry_foreach(iter0, entry0, compatr->size) 1444 compat_copy_entry_from_user(iter0, &pos, &size, 1445 newinfo, entry1); 1446 1447 /* all module references in entry0 are now gone. 1448 * entry1/newinfo contains a 64bit ruleset that looks exactly as 1449 * generated by 64bit userspace. 1450 * 1451 * Call standard translate_table() to validate all hook_entrys, 1452 * underflows, check for loops, etc. 1453 */ 1454 xt_compat_flush_offsets(AF_INET); 1455 xt_compat_unlock(AF_INET); 1456 1457 memcpy(&repl, compatr, sizeof(*compatr)); 1458 1459 for (i = 0; i < NF_INET_NUMHOOKS; i++) { 1460 repl.hook_entry[i] = newinfo->hook_entry[i]; 1461 repl.underflow[i] = newinfo->underflow[i]; 1462 } 1463 1464 repl.num_counters = 0; 1465 repl.counters = NULL; 1466 repl.size = newinfo->size; 1467 ret = translate_table(net, newinfo, entry1, &repl); 1468 if (ret) 1469 goto free_newinfo; 1470 1471 *pinfo = newinfo; 1472 *pentry0 = entry1; 1473 xt_free_table_info(info); 1474 return 0; 1475 1476free_newinfo: 1477 xt_free_table_info(newinfo); 1478 return ret; 1479out_unlock: 1480 xt_compat_flush_offsets(AF_INET); 1481 xt_compat_unlock(AF_INET); 1482 xt_entry_foreach(iter0, entry0, compatr->size) { 1483 if (j-- == 0) 1484 break; 1485 compat_release_entry(iter0); 1486 } 1487 return ret; 1488} 1489 1490static int 1491compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) 1492{ 1493 int ret; 1494 struct compat_ipt_replace tmp; 1495 struct xt_table_info *newinfo; 1496 void *loc_cpu_entry; 1497 struct ipt_entry *iter; 1498 1499 if (len < sizeof(tmp)) 1500 return -EINVAL; 1501 if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) 1502 return -EFAULT; 1503 1504 /* overflow check */ 1505 if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) 1506 return -ENOMEM; 1507 if (tmp.num_counters == 0) 1508 return -EINVAL; 1509 if ((u64)len < (u64)tmp.size + sizeof(tmp)) 1510 return -EINVAL; 1511 1512 tmp.name[sizeof(tmp.name)-1] = 0; 1513 1514 newinfo = xt_alloc_table_info(tmp.size); 1515 if (!newinfo) 1516 return -ENOMEM; 1517 1518 loc_cpu_entry = newinfo->entries; 1519 if (copy_from_sockptr_offset(loc_cpu_entry, arg, sizeof(tmp), 1520 tmp.size) != 0) { 1521 ret = -EFAULT; 1522 goto free_newinfo; 1523 } 1524 1525 ret = translate_compat_table(net, &newinfo, &loc_cpu_entry, &tmp); 1526 if (ret != 0) 1527 goto free_newinfo; 1528 1529 ret = __do_replace(net, tmp.name, tmp.valid_hooks, newinfo, 1530 tmp.num_counters, compat_ptr(tmp.counters)); 1531 if (ret) 1532 goto free_newinfo_untrans; 1533 return 0; 1534 1535 free_newinfo_untrans: 1536 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1537 cleanup_entry(iter, net); 1538 free_newinfo: 1539 xt_free_table_info(newinfo); 1540 return ret; 1541} 1542 1543struct compat_ipt_get_entries { 1544 char name[XT_TABLE_MAXNAMELEN]; 1545 compat_uint_t size; 1546 struct compat_ipt_entry entrytable[]; 1547}; 1548 1549static int 1550compat_copy_entries_to_user(unsigned int total_size, struct xt_table *table, 1551 void __user *userptr) 1552{ 1553 struct xt_counters *counters; 1554 const struct xt_table_info *private = table->private; 1555 void __user *pos; 1556 unsigned int size; 1557 int ret = 0; 1558 unsigned int i = 0; 1559 struct ipt_entry *iter; 1560 1561 counters = alloc_counters(table); 1562 if (IS_ERR(counters)) 1563 return PTR_ERR(counters); 1564 1565 pos = userptr; 1566 size = total_size; 1567 xt_entry_foreach(iter, private->entries, total_size) { 1568 ret = compat_copy_entry_to_user(iter, &pos, 1569 &size, counters, i++); 1570 if (ret != 0) 1571 break; 1572 } 1573 1574 vfree(counters); 1575 return ret; 1576} 1577 1578static int 1579compat_get_entries(struct net *net, struct compat_ipt_get_entries __user *uptr, 1580 int *len) 1581{ 1582 int ret; 1583 struct compat_ipt_get_entries get; 1584 struct xt_table *t; 1585 1586 if (*len < sizeof(get)) 1587 return -EINVAL; 1588 1589 if (copy_from_user(&get, uptr, sizeof(get)) != 0) 1590 return -EFAULT; 1591 1592 if (*len != sizeof(struct compat_ipt_get_entries) + get.size) 1593 return -EINVAL; 1594 1595 get.name[sizeof(get.name) - 1] = '\0'; 1596 1597 xt_compat_lock(AF_INET); 1598 t = xt_find_table_lock(net, AF_INET, get.name); 1599 if (!IS_ERR(t)) { 1600 const struct xt_table_info *private = t->private; 1601 struct xt_table_info info; 1602 ret = compat_table_info(private, &info); 1603 if (!ret && get.size == info.size) 1604 ret = compat_copy_entries_to_user(private->size, 1605 t, uptr->entrytable); 1606 else if (!ret) 1607 ret = -EAGAIN; 1608 1609 xt_compat_flush_offsets(AF_INET); 1610 module_put(t->me); 1611 xt_table_unlock(t); 1612 } else 1613 ret = PTR_ERR(t); 1614 1615 xt_compat_unlock(AF_INET); 1616 return ret; 1617} 1618#endif 1619 1620static int 1621do_ipt_set_ctl(struct sock *sk, int cmd, sockptr_t arg, unsigned int len) 1622{ 1623 int ret; 1624 1625 if (!ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN)) 1626 return -EPERM; 1627 1628 switch (cmd) { 1629 case IPT_SO_SET_REPLACE: 1630#ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1631 if (in_compat_syscall()) 1632 ret = compat_do_replace(sock_net(sk), arg, len); 1633 else 1634#endif 1635 ret = do_replace(sock_net(sk), arg, len); 1636 break; 1637 1638 case IPT_SO_SET_ADD_COUNTERS: 1639 ret = do_add_counters(sock_net(sk), arg, len); 1640 break; 1641 1642 default: 1643 ret = -EINVAL; 1644 } 1645 1646 return ret; 1647} 1648 1649static int 1650do_ipt_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 IPT_SO_GET_INFO: 1659 ret = get_info(sock_net(sk), user, len); 1660 break; 1661 1662 case IPT_SO_GET_ENTRIES: 1663#ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1664 if (in_compat_syscall()) 1665 ret = compat_get_entries(sock_net(sk), user, len); 1666 else 1667#endif 1668 ret = get_entries(sock_net(sk), user, len); 1669 break; 1670 1671 case IPT_SO_GET_REVISION_MATCH: 1672 case IPT_SO_GET_REVISION_TARGET: { 1673 struct xt_get_revision rev; 1674 int target; 1675 1676 if (*len != sizeof(rev)) { 1677 ret = -EINVAL; 1678 break; 1679 } 1680 if (copy_from_user(&rev, user, sizeof(rev)) != 0) { 1681 ret = -EFAULT; 1682 break; 1683 } 1684 rev.name[sizeof(rev.name)-1] = 0; 1685 1686 if (cmd == IPT_SO_GET_REVISION_TARGET) 1687 target = 1; 1688 else 1689 target = 0; 1690 1691 try_then_request_module(xt_find_revision(AF_INET, rev.name, 1692 rev.revision, 1693 target, &ret), 1694 "ipt_%s", rev.name); 1695 break; 1696 } 1697 1698 default: 1699 ret = -EINVAL; 1700 } 1701 1702 return ret; 1703} 1704 1705static void __ipt_unregister_table(struct net *net, struct xt_table *table) 1706{ 1707 struct xt_table_info *private; 1708 void *loc_cpu_entry; 1709 struct module *table_owner = table->me; 1710 struct ipt_entry *iter; 1711 1712 private = xt_unregister_table(table); 1713 1714 /* Decrease module usage counts and free resources */ 1715 loc_cpu_entry = private->entries; 1716 xt_entry_foreach(iter, loc_cpu_entry, private->size) 1717 cleanup_entry(iter, net); 1718 if (private->number > private->initial_entries) 1719 module_put(table_owner); 1720 xt_free_table_info(private); 1721} 1722 1723int ipt_register_table(struct net *net, const struct xt_table *table, 1724 const struct ipt_replace *repl, 1725 const struct nf_hook_ops *template_ops) 1726{ 1727 struct nf_hook_ops *ops; 1728 unsigned int num_ops; 1729 int ret, i; 1730 struct xt_table_info *newinfo; 1731 struct xt_table_info bootstrap = {0}; 1732 void *loc_cpu_entry; 1733 struct xt_table *new_table; 1734 1735 newinfo = xt_alloc_table_info(repl->size); 1736 if (!newinfo) 1737 return -ENOMEM; 1738 1739 loc_cpu_entry = newinfo->entries; 1740 memcpy(loc_cpu_entry, repl->entries, repl->size); 1741 1742 ret = translate_table(net, newinfo, loc_cpu_entry, repl); 1743 if (ret != 0) { 1744 xt_free_table_info(newinfo); 1745 return ret; 1746 } 1747 1748 new_table = xt_register_table(net, table, &bootstrap, newinfo); 1749 if (IS_ERR(new_table)) { 1750 struct ipt_entry *iter; 1751 1752 xt_entry_foreach(iter, loc_cpu_entry, newinfo->size) 1753 cleanup_entry(iter, net); 1754 xt_free_table_info(newinfo); 1755 return PTR_ERR(new_table); 1756 } 1757 1758 /* No template? No need to do anything. This is used by 'nat' table, it registers 1759 * with the nat core instead of the netfilter core. 1760 */ 1761 if (!template_ops) 1762 return 0; 1763 1764 num_ops = hweight32(table->valid_hooks); 1765 if (num_ops == 0) { 1766 ret = -EINVAL; 1767 goto out_free; 1768 } 1769 1770 ops = kmemdup_array(template_ops, num_ops, sizeof(*ops), GFP_KERNEL); 1771 if (!ops) { 1772 ret = -ENOMEM; 1773 goto out_free; 1774 } 1775 1776 for (i = 0; i < num_ops; i++) 1777 ops[i].priv = new_table; 1778 1779 new_table->ops = ops; 1780 1781 ret = nf_register_net_hooks(net, ops, num_ops); 1782 if (ret != 0) 1783 goto out_free; 1784 1785 return ret; 1786 1787out_free: 1788 __ipt_unregister_table(net, new_table); 1789 return ret; 1790} 1791 1792void ipt_unregister_table_pre_exit(struct net *net, const char *name) 1793{ 1794 struct xt_table *table = xt_find_table(net, NFPROTO_IPV4, name); 1795 1796 if (table) 1797 nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks)); 1798} 1799 1800void ipt_unregister_table_exit(struct net *net, const char *name) 1801{ 1802 struct xt_table *table = xt_find_table(net, NFPROTO_IPV4, name); 1803 1804 if (table) 1805 __ipt_unregister_table(net, table); 1806} 1807 1808static struct xt_target ipt_builtin_tg[] __read_mostly = { 1809 { 1810 .name = XT_STANDARD_TARGET, 1811 .targetsize = sizeof(int), 1812 .family = NFPROTO_IPV4, 1813#ifdef CONFIG_NETFILTER_XTABLES_COMPAT 1814 .compatsize = sizeof(compat_int_t), 1815 .compat_from_user = compat_standard_from_user, 1816 .compat_to_user = compat_standard_to_user, 1817#endif 1818 }, 1819 { 1820 .name = XT_ERROR_TARGET, 1821 .target = ipt_error, 1822 .targetsize = XT_FUNCTION_MAXNAMELEN, 1823 .family = NFPROTO_IPV4, 1824 }, 1825}; 1826 1827static struct nf_sockopt_ops ipt_sockopts = { 1828 .pf = PF_INET, 1829 .set_optmin = IPT_BASE_CTL, 1830 .set_optmax = IPT_SO_SET_MAX+1, 1831 .set = do_ipt_set_ctl, 1832 .get_optmin = IPT_BASE_CTL, 1833 .get_optmax = IPT_SO_GET_MAX+1, 1834 .get = do_ipt_get_ctl, 1835 .owner = THIS_MODULE, 1836}; 1837 1838static int __net_init ip_tables_net_init(struct net *net) 1839{ 1840 return xt_proto_init(net, NFPROTO_IPV4); 1841} 1842 1843static void __net_exit ip_tables_net_exit(struct net *net) 1844{ 1845 xt_proto_fini(net, NFPROTO_IPV4); 1846} 1847 1848static struct pernet_operations ip_tables_net_ops = { 1849 .init = ip_tables_net_init, 1850 .exit = ip_tables_net_exit, 1851}; 1852 1853static int __init ip_tables_init(void) 1854{ 1855 int ret; 1856 1857 ret = register_pernet_subsys(&ip_tables_net_ops); 1858 if (ret < 0) 1859 goto err1; 1860 1861 /* No one else will be downing sem now, so we won't sleep */ 1862 ret = xt_register_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); 1863 if (ret < 0) 1864 goto err2; 1865 1866 /* Register setsockopt */ 1867 ret = nf_register_sockopt(&ipt_sockopts); 1868 if (ret < 0) 1869 goto err4; 1870 1871 return 0; 1872 1873err4: 1874 xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); 1875err2: 1876 unregister_pernet_subsys(&ip_tables_net_ops); 1877err1: 1878 return ret; 1879} 1880 1881static void __exit ip_tables_fini(void) 1882{ 1883 nf_unregister_sockopt(&ipt_sockopts); 1884 1885 xt_unregister_targets(ipt_builtin_tg, ARRAY_SIZE(ipt_builtin_tg)); 1886 unregister_pernet_subsys(&ip_tables_net_ops); 1887} 1888 1889EXPORT_SYMBOL(ipt_register_table); 1890EXPORT_SYMBOL(ipt_unregister_table_pre_exit); 1891EXPORT_SYMBOL(ipt_unregister_table_exit); 1892EXPORT_SYMBOL(ipt_do_table); 1893module_init(ip_tables_init); 1894module_exit(ip_tables_fini);
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