1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * (C) 2012-2013 by Pablo Neira Ayuso <pablo@netfilter.org> 4 * 5 * This software has been sponsored by Sophos Astaro <http://www.sophos.com> 6 */ 7 8#include <linux/kernel.h> 9#include <linux/init.h> 10#include <linux/module.h> 11#include <linux/netlink.h> 12#include <linux/netfilter.h> 13#include <linux/netfilter/nfnetlink.h> 14#include <linux/netfilter/nf_tables.h> 15#include <linux/netfilter/nf_tables_compat.h> 16#include <linux/netfilter/x_tables.h> 17#include <linux/netfilter_ipv4/ip_tables.h> 18#include <linux/netfilter_ipv6/ip6_tables.h> 19#include <linux/netfilter_bridge/ebtables.h> 20#include <linux/netfilter_arp/arp_tables.h> 21#include <net/netfilter/nf_tables.h> 22#include <net/netfilter/nf_log.h> 23 24/* Used for matches where *info is larger than X byte */ 25#define NFT_MATCH_LARGE_THRESH 192 26 27struct nft_xt_match_priv { 28 void *info; 29}; 30 31static int nft_compat_chain_validate_dependency(const struct nft_ctx *ctx, 32 const char *tablename) 33{ 34 enum nft_chain_types type = NFT_CHAIN_T_DEFAULT; 35 const struct nft_chain *chain = ctx->chain; 36 const struct nft_base_chain *basechain; 37 38 if (!tablename || 39 !nft_is_base_chain(chain)) 40 return 0; 41 42 basechain = nft_base_chain(chain); 43 if (strcmp(tablename, "nat") == 0) { 44 if (ctx->family != NFPROTO_BRIDGE) 45 type = NFT_CHAIN_T_NAT; 46 if (basechain->type->type != type) 47 return -EINVAL; 48 } 49 50 return 0; 51} 52 53union nft_entry { 54 struct ipt_entry e4; 55 struct ip6t_entry e6; 56 struct ebt_entry ebt; 57 struct arpt_entry arp; 58}; 59 60static inline void 61nft_compat_set_par(struct xt_action_param *par, 62 const struct nft_pktinfo *pkt, 63 const void *xt, const void *xt_info) 64{ 65 par->state = pkt->state; 66 par->thoff = nft_thoff(pkt); 67 par->fragoff = pkt->fragoff; 68 par->target = xt; 69 par->targinfo = xt_info; 70 par->hotdrop = false; 71} 72 73static void nft_target_eval_xt(const struct nft_expr *expr, 74 struct nft_regs *regs, 75 const struct nft_pktinfo *pkt) 76{ 77 void *info = nft_expr_priv(expr); 78 struct xt_target *target = expr->ops->data; 79 struct sk_buff *skb = pkt->skb; 80 struct xt_action_param xt; 81 int ret; 82 83 nft_compat_set_par(&xt, pkt, target, info); 84 85 ret = target->target(skb, &xt); 86 87 if (xt.hotdrop) 88 ret = NF_DROP; 89 90 switch (ret) { 91 case XT_CONTINUE: 92 regs->verdict.code = NFT_CONTINUE; 93 break; 94 default: 95 regs->verdict.code = ret; 96 break; 97 } 98} 99 100static void nft_target_eval_bridge(const struct nft_expr *expr, 101 struct nft_regs *regs, 102 const struct nft_pktinfo *pkt) 103{ 104 void *info = nft_expr_priv(expr); 105 struct xt_target *target = expr->ops->data; 106 struct sk_buff *skb = pkt->skb; 107 struct xt_action_param xt; 108 int ret; 109 110 nft_compat_set_par(&xt, pkt, target, info); 111 112 ret = target->target(skb, &xt); 113 114 if (xt.hotdrop) 115 ret = NF_DROP; 116 117 switch (ret) { 118 case EBT_ACCEPT: 119 regs->verdict.code = NF_ACCEPT; 120 break; 121 case EBT_DROP: 122 regs->verdict.code = NF_DROP; 123 break; 124 case EBT_CONTINUE: 125 regs->verdict.code = NFT_CONTINUE; 126 break; 127 case EBT_RETURN: 128 regs->verdict.code = NFT_RETURN; 129 break; 130 default: 131 regs->verdict.code = ret; 132 break; 133 } 134} 135 136static const struct nla_policy nft_target_policy[NFTA_TARGET_MAX + 1] = { 137 [NFTA_TARGET_NAME] = { .type = NLA_NUL_STRING }, 138 [NFTA_TARGET_REV] = NLA_POLICY_MAX(NLA_BE32, 255), 139 [NFTA_TARGET_INFO] = { .type = NLA_BINARY }, 140}; 141 142static void 143nft_target_set_tgchk_param(struct xt_tgchk_param *par, 144 const struct nft_ctx *ctx, 145 struct xt_target *target, void *info, 146 union nft_entry *entry, u16 proto, bool inv) 147{ 148 par->net = ctx->net; 149 par->table = ctx->table->name; 150 switch (ctx->family) { 151 case AF_INET: 152 entry->e4.ip.proto = proto; 153 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; 154 break; 155 case AF_INET6: 156 if (proto) 157 entry->e6.ipv6.flags |= IP6T_F_PROTO; 158 159 entry->e6.ipv6.proto = proto; 160 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; 161 break; 162 case NFPROTO_BRIDGE: 163 entry->ebt.ethproto = (__force __be16)proto; 164 entry->ebt.invflags = inv ? EBT_IPROTO : 0; 165 break; 166 case NFPROTO_ARP: 167 break; 168 } 169 par->entryinfo = entry; 170 par->target = target; 171 par->targinfo = info; 172 if (nft_is_base_chain(ctx->chain)) { 173 const struct nft_base_chain *basechain = 174 nft_base_chain(ctx->chain); 175 const struct nf_hook_ops *ops = &basechain->ops; 176 177 par->hook_mask = 1 << ops->hooknum; 178 } else { 179 par->hook_mask = 0; 180 } 181 par->family = ctx->family; 182 par->nft_compat = true; 183} 184 185static void target_compat_from_user(struct xt_target *t, void *in, void *out) 186{ 187 int pad; 188 189 memcpy(out, in, t->targetsize); 190 pad = XT_ALIGN(t->targetsize) - t->targetsize; 191 if (pad > 0) 192 memset(out + t->targetsize, 0, pad); 193} 194 195static const struct nla_policy nft_rule_compat_policy[NFTA_RULE_COMPAT_MAX + 1] = { 196 [NFTA_RULE_COMPAT_PROTO] = { .type = NLA_U32 }, 197 [NFTA_RULE_COMPAT_FLAGS] = { .type = NLA_U32 }, 198}; 199 200static int nft_parse_compat(const struct nlattr *attr, u16 *proto, bool *inv) 201{ 202 struct nlattr *tb[NFTA_RULE_COMPAT_MAX+1]; 203 u32 l4proto; 204 u32 flags; 205 int err; 206 207 err = nla_parse_nested_deprecated(tb, NFTA_RULE_COMPAT_MAX, attr, 208 nft_rule_compat_policy, NULL); 209 if (err < 0) 210 return err; 211 212 if (!tb[NFTA_RULE_COMPAT_PROTO] || !tb[NFTA_RULE_COMPAT_FLAGS]) 213 return -EINVAL; 214 215 flags = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_FLAGS])); 216 if (flags & NFT_RULE_COMPAT_F_UNUSED || 217 flags & ~NFT_RULE_COMPAT_F_MASK) 218 return -EINVAL; 219 if (flags & NFT_RULE_COMPAT_F_INV) 220 *inv = true; 221 222 l4proto = ntohl(nla_get_be32(tb[NFTA_RULE_COMPAT_PROTO])); 223 if (l4proto > U16_MAX) 224 return -EINVAL; 225 226 *proto = l4proto; 227 228 return 0; 229} 230 231static void nft_compat_wait_for_destructors(void) 232{ 233 /* xtables matches or targets can have side effects, e.g. 234 * creation/destruction of /proc files. 235 * The xt ->destroy functions are run asynchronously from 236 * work queue. If we have pending invocations we thus 237 * need to wait for those to finish. 238 */ 239 nf_tables_trans_destroy_flush_work(); 240} 241 242static int 243nft_target_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 244 const struct nlattr * const tb[]) 245{ 246 void *info = nft_expr_priv(expr); 247 struct xt_target *target = expr->ops->data; 248 struct xt_tgchk_param par; 249 size_t size = XT_ALIGN(nla_len(tb[NFTA_TARGET_INFO])); 250 u16 proto = 0; 251 bool inv = false; 252 union nft_entry e = {}; 253 int ret; 254 255 target_compat_from_user(target, nla_data(tb[NFTA_TARGET_INFO]), info); 256 257 if (ctx->nla[NFTA_RULE_COMPAT]) { 258 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv); 259 if (ret < 0) 260 return ret; 261 } 262 263 nft_target_set_tgchk_param(&par, ctx, target, info, &e, proto, inv); 264 265 nft_compat_wait_for_destructors(); 266 267 ret = xt_check_target(&par, size, proto, inv); 268 if (ret < 0) { 269 if (ret == -ENOENT) { 270 const char *modname = NULL; 271 272 if (strcmp(target->name, "LOG") == 0) 273 modname = "nf_log_syslog"; 274 else if (strcmp(target->name, "NFLOG") == 0) 275 modname = "nfnetlink_log"; 276 277 if (modname && 278 nft_request_module(ctx->net, "%s", modname) == -EAGAIN) 279 return -EAGAIN; 280 } 281 282 return ret; 283 } 284 285 /* The standard target cannot be used */ 286 if (!target->target) 287 return -EINVAL; 288 289 return 0; 290} 291 292static void __nft_mt_tg_destroy(struct module *me, const struct nft_expr *expr) 293{ 294 module_put(me); 295 kfree(expr->ops); 296} 297 298static void 299nft_target_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) 300{ 301 struct xt_target *target = expr->ops->data; 302 void *info = nft_expr_priv(expr); 303 struct module *me = target->me; 304 struct xt_tgdtor_param par; 305 306 par.net = ctx->net; 307 par.target = target; 308 par.targinfo = info; 309 par.family = ctx->family; 310 if (par.target->destroy != NULL) 311 par.target->destroy(&par); 312 313 __nft_mt_tg_destroy(me, expr); 314} 315 316static int nft_extension_dump_info(struct sk_buff *skb, int attr, 317 const void *info, 318 unsigned int size, unsigned int user_size) 319{ 320 unsigned int info_size, aligned_size = XT_ALIGN(size); 321 struct nlattr *nla; 322 323 nla = nla_reserve(skb, attr, aligned_size); 324 if (!nla) 325 return -1; 326 327 info_size = user_size ? : size; 328 memcpy(nla_data(nla), info, info_size); 329 memset(nla_data(nla) + info_size, 0, aligned_size - info_size); 330 331 return 0; 332} 333 334static int nft_target_dump(struct sk_buff *skb, 335 const struct nft_expr *expr, bool reset) 336{ 337 const struct xt_target *target = expr->ops->data; 338 void *info = nft_expr_priv(expr); 339 340 if (nla_put_string(skb, NFTA_TARGET_NAME, target->name) || 341 nla_put_be32(skb, NFTA_TARGET_REV, htonl(target->revision)) || 342 nft_extension_dump_info(skb, NFTA_TARGET_INFO, info, 343 target->targetsize, target->usersize)) 344 goto nla_put_failure; 345 346 return 0; 347 348nla_put_failure: 349 return -1; 350} 351 352static int nft_target_validate(const struct nft_ctx *ctx, 353 const struct nft_expr *expr, 354 const struct nft_data **data) 355{ 356 struct xt_target *target = expr->ops->data; 357 unsigned int hook_mask = 0; 358 int ret; 359 360 if (ctx->family != NFPROTO_IPV4 && 361 ctx->family != NFPROTO_IPV6 && 362 ctx->family != NFPROTO_INET && 363 ctx->family != NFPROTO_BRIDGE && 364 ctx->family != NFPROTO_ARP) 365 return -EOPNOTSUPP; 366 367 ret = nft_chain_validate_hooks(ctx->chain, 368 (1 << NF_INET_PRE_ROUTING) | 369 (1 << NF_INET_LOCAL_IN) | 370 (1 << NF_INET_FORWARD) | 371 (1 << NF_INET_LOCAL_OUT) | 372 (1 << NF_INET_POST_ROUTING)); 373 if (ret) 374 return ret; 375 376 if (nft_is_base_chain(ctx->chain)) { 377 const struct nft_base_chain *basechain = 378 nft_base_chain(ctx->chain); 379 const struct nf_hook_ops *ops = &basechain->ops; 380 381 hook_mask = 1 << ops->hooknum; 382 if (target->hooks && !(hook_mask & target->hooks)) 383 return -EINVAL; 384 385 ret = nft_compat_chain_validate_dependency(ctx, target->table); 386 if (ret < 0) 387 return ret; 388 } 389 return 0; 390} 391 392static void __nft_match_eval(const struct nft_expr *expr, 393 struct nft_regs *regs, 394 const struct nft_pktinfo *pkt, 395 void *info) 396{ 397 struct xt_match *match = expr->ops->data; 398 struct sk_buff *skb = pkt->skb; 399 struct xt_action_param xt; 400 bool ret; 401 402 nft_compat_set_par(&xt, pkt, match, info); 403 404 ret = match->match(skb, &xt); 405 406 if (xt.hotdrop) { 407 regs->verdict.code = NF_DROP; 408 return; 409 } 410 411 switch (ret ? 1 : 0) { 412 case 1: 413 regs->verdict.code = NFT_CONTINUE; 414 break; 415 case 0: 416 regs->verdict.code = NFT_BREAK; 417 break; 418 } 419} 420 421static void nft_match_large_eval(const struct nft_expr *expr, 422 struct nft_regs *regs, 423 const struct nft_pktinfo *pkt) 424{ 425 struct nft_xt_match_priv *priv = nft_expr_priv(expr); 426 427 __nft_match_eval(expr, regs, pkt, priv->info); 428} 429 430static void nft_match_eval(const struct nft_expr *expr, 431 struct nft_regs *regs, 432 const struct nft_pktinfo *pkt) 433{ 434 __nft_match_eval(expr, regs, pkt, nft_expr_priv(expr)); 435} 436 437static const struct nla_policy nft_match_policy[NFTA_MATCH_MAX + 1] = { 438 [NFTA_MATCH_NAME] = { .type = NLA_NUL_STRING }, 439 [NFTA_MATCH_REV] = NLA_POLICY_MAX(NLA_BE32, 255), 440 [NFTA_MATCH_INFO] = { .type = NLA_BINARY }, 441}; 442 443/* struct xt_mtchk_param and xt_tgchk_param look very similar */ 444static void 445nft_match_set_mtchk_param(struct xt_mtchk_param *par, const struct nft_ctx *ctx, 446 struct xt_match *match, void *info, 447 union nft_entry *entry, u16 proto, bool inv) 448{ 449 par->net = ctx->net; 450 par->table = ctx->table->name; 451 switch (ctx->family) { 452 case AF_INET: 453 entry->e4.ip.proto = proto; 454 entry->e4.ip.invflags = inv ? IPT_INV_PROTO : 0; 455 break; 456 case AF_INET6: 457 if (proto) 458 entry->e6.ipv6.flags |= IP6T_F_PROTO; 459 460 entry->e6.ipv6.proto = proto; 461 entry->e6.ipv6.invflags = inv ? IP6T_INV_PROTO : 0; 462 break; 463 case NFPROTO_BRIDGE: 464 entry->ebt.ethproto = (__force __be16)proto; 465 entry->ebt.invflags = inv ? EBT_IPROTO : 0; 466 break; 467 case NFPROTO_ARP: 468 break; 469 } 470 par->entryinfo = entry; 471 par->match = match; 472 par->matchinfo = info; 473 if (nft_is_base_chain(ctx->chain)) { 474 const struct nft_base_chain *basechain = 475 nft_base_chain(ctx->chain); 476 const struct nf_hook_ops *ops = &basechain->ops; 477 478 par->hook_mask = 1 << ops->hooknum; 479 } else { 480 par->hook_mask = 0; 481 } 482 par->family = ctx->family; 483 par->nft_compat = true; 484} 485 486static void match_compat_from_user(struct xt_match *m, void *in, void *out) 487{ 488 int pad; 489 490 memcpy(out, in, m->matchsize); 491 pad = XT_ALIGN(m->matchsize) - m->matchsize; 492 if (pad > 0) 493 memset(out + m->matchsize, 0, pad); 494} 495 496static int 497__nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 498 const struct nlattr * const tb[], 499 void *info) 500{ 501 struct xt_match *match = expr->ops->data; 502 struct xt_mtchk_param par; 503 size_t size = XT_ALIGN(nla_len(tb[NFTA_MATCH_INFO])); 504 u16 proto = 0; 505 bool inv = false; 506 union nft_entry e = {}; 507 int ret; 508 509 match_compat_from_user(match, nla_data(tb[NFTA_MATCH_INFO]), info); 510 511 if (ctx->nla[NFTA_RULE_COMPAT]) { 512 ret = nft_parse_compat(ctx->nla[NFTA_RULE_COMPAT], &proto, &inv); 513 if (ret < 0) 514 return ret; 515 } 516 517 nft_match_set_mtchk_param(&par, ctx, match, info, &e, proto, inv); 518 519 nft_compat_wait_for_destructors(); 520 521 return xt_check_match(&par, size, proto, inv); 522} 523 524static int 525nft_match_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 526 const struct nlattr * const tb[]) 527{ 528 return __nft_match_init(ctx, expr, tb, nft_expr_priv(expr)); 529} 530 531static int 532nft_match_large_init(const struct nft_ctx *ctx, const struct nft_expr *expr, 533 const struct nlattr * const tb[]) 534{ 535 struct nft_xt_match_priv *priv = nft_expr_priv(expr); 536 struct xt_match *m = expr->ops->data; 537 int ret; 538 539 priv->info = kmalloc(XT_ALIGN(m->matchsize), GFP_KERNEL); 540 if (!priv->info) 541 return -ENOMEM; 542 543 ret = __nft_match_init(ctx, expr, tb, priv->info); 544 if (ret) 545 kfree(priv->info); 546 return ret; 547} 548 549static void 550__nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr, 551 void *info) 552{ 553 struct xt_match *match = expr->ops->data; 554 struct module *me = match->me; 555 struct xt_mtdtor_param par; 556 557 par.net = ctx->net; 558 par.match = match; 559 par.matchinfo = info; 560 par.family = ctx->family; 561 if (par.match->destroy != NULL) 562 par.match->destroy(&par); 563 564 __nft_mt_tg_destroy(me, expr); 565} 566 567static void 568nft_match_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) 569{ 570 __nft_match_destroy(ctx, expr, nft_expr_priv(expr)); 571} 572 573static void 574nft_match_large_destroy(const struct nft_ctx *ctx, const struct nft_expr *expr) 575{ 576 struct nft_xt_match_priv *priv = nft_expr_priv(expr); 577 578 __nft_match_destroy(ctx, expr, priv->info); 579 kfree(priv->info); 580} 581 582static int __nft_match_dump(struct sk_buff *skb, const struct nft_expr *expr, 583 void *info) 584{ 585 struct xt_match *match = expr->ops->data; 586 587 if (nla_put_string(skb, NFTA_MATCH_NAME, match->name) || 588 nla_put_be32(skb, NFTA_MATCH_REV, htonl(match->revision)) || 589 nft_extension_dump_info(skb, NFTA_MATCH_INFO, info, 590 match->matchsize, match->usersize)) 591 goto nla_put_failure; 592 593 return 0; 594 595nla_put_failure: 596 return -1; 597} 598 599static int nft_match_dump(struct sk_buff *skb, 600 const struct nft_expr *expr, bool reset) 601{ 602 return __nft_match_dump(skb, expr, nft_expr_priv(expr)); 603} 604 605static int nft_match_large_dump(struct sk_buff *skb, 606 const struct nft_expr *e, bool reset) 607{ 608 struct nft_xt_match_priv *priv = nft_expr_priv(e); 609 610 return __nft_match_dump(skb, e, priv->info); 611} 612 613static int nft_match_validate(const struct nft_ctx *ctx, 614 const struct nft_expr *expr, 615 const struct nft_data **data) 616{ 617 struct xt_match *match = expr->ops->data; 618 unsigned int hook_mask = 0; 619 int ret; 620 621 if (ctx->family != NFPROTO_IPV4 && 622 ctx->family != NFPROTO_IPV6 && 623 ctx->family != NFPROTO_INET && 624 ctx->family != NFPROTO_BRIDGE && 625 ctx->family != NFPROTO_ARP) 626 return -EOPNOTSUPP; 627 628 ret = nft_chain_validate_hooks(ctx->chain, 629 (1 << NF_INET_PRE_ROUTING) | 630 (1 << NF_INET_LOCAL_IN) | 631 (1 << NF_INET_FORWARD) | 632 (1 << NF_INET_LOCAL_OUT) | 633 (1 << NF_INET_POST_ROUTING)); 634 if (ret) 635 return ret; 636 637 if (nft_is_base_chain(ctx->chain)) { 638 const struct nft_base_chain *basechain = 639 nft_base_chain(ctx->chain); 640 const struct nf_hook_ops *ops = &basechain->ops; 641 642 hook_mask = 1 << ops->hooknum; 643 if (match->hooks && !(hook_mask & match->hooks)) 644 return -EINVAL; 645 646 ret = nft_compat_chain_validate_dependency(ctx, match->table); 647 if (ret < 0) 648 return ret; 649 } 650 return 0; 651} 652 653static int 654nfnl_compat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type, 655 int event, u16 family, const char *name, 656 int rev, int target) 657{ 658 struct nlmsghdr *nlh; 659 unsigned int flags = portid ? NLM_F_MULTI : 0; 660 661 event = nfnl_msg_type(NFNL_SUBSYS_NFT_COMPAT, event); 662 nlh = nfnl_msg_put(skb, portid, seq, event, flags, family, 663 NFNETLINK_V0, 0); 664 if (!nlh) 665 goto nlmsg_failure; 666 667 if (nla_put_string(skb, NFTA_COMPAT_NAME, name) || 668 nla_put_be32(skb, NFTA_COMPAT_REV, htonl(rev)) || 669 nla_put_be32(skb, NFTA_COMPAT_TYPE, htonl(target))) 670 goto nla_put_failure; 671 672 nlmsg_end(skb, nlh); 673 return skb->len; 674 675nlmsg_failure: 676nla_put_failure: 677 nlmsg_cancel(skb, nlh); 678 return -1; 679} 680 681static int nfnl_compat_get_rcu(struct sk_buff *skb, 682 const struct nfnl_info *info, 683 const struct nlattr * const tb[]) 684{ 685 u8 family = info->nfmsg->nfgen_family; 686 const char *name, *fmt; 687 struct sk_buff *skb2; 688 int ret = 0, target; 689 u32 rev; 690 691 if (tb[NFTA_COMPAT_NAME] == NULL || 692 tb[NFTA_COMPAT_REV] == NULL || 693 tb[NFTA_COMPAT_TYPE] == NULL) 694 return -EINVAL; 695 696 name = nla_data(tb[NFTA_COMPAT_NAME]); 697 rev = ntohl(nla_get_be32(tb[NFTA_COMPAT_REV])); 698 target = ntohl(nla_get_be32(tb[NFTA_COMPAT_TYPE])); 699 700 switch(family) { 701 case AF_INET: 702 fmt = "ipt_%s"; 703 break; 704 case AF_INET6: 705 fmt = "ip6t_%s"; 706 break; 707 case NFPROTO_BRIDGE: 708 fmt = "ebt_%s"; 709 break; 710 case NFPROTO_ARP: 711 fmt = "arpt_%s"; 712 break; 713 default: 714 pr_err("nft_compat: unsupported protocol %d\n", family); 715 return -EINVAL; 716 } 717 718 if (!try_module_get(THIS_MODULE)) 719 return -EINVAL; 720 721 rcu_read_unlock(); 722 try_then_request_module(xt_find_revision(family, name, rev, target, &ret), 723 fmt, name); 724 if (ret < 0) 725 goto out_put; 726 727 skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 728 if (skb2 == NULL) { 729 ret = -ENOMEM; 730 goto out_put; 731 } 732 733 /* include the best revision for this extension in the message */ 734 if (nfnl_compat_fill_info(skb2, NETLINK_CB(skb).portid, 735 info->nlh->nlmsg_seq, 736 NFNL_MSG_TYPE(info->nlh->nlmsg_type), 737 NFNL_MSG_COMPAT_GET, 738 family, name, ret, target) <= 0) { 739 kfree_skb(skb2); 740 goto out_put; 741 } 742 743 ret = nfnetlink_unicast(skb2, info->net, NETLINK_CB(skb).portid); 744out_put: 745 rcu_read_lock(); 746 module_put(THIS_MODULE); 747 748 return ret; 749} 750 751static const struct nla_policy nfnl_compat_policy_get[NFTA_COMPAT_MAX+1] = { 752 [NFTA_COMPAT_NAME] = { .type = NLA_NUL_STRING, 753 .len = NFT_COMPAT_NAME_MAX-1 }, 754 [NFTA_COMPAT_REV] = NLA_POLICY_MAX(NLA_BE32, 255), 755 [NFTA_COMPAT_TYPE] = { .type = NLA_U32 }, 756}; 757 758static const struct nfnl_callback nfnl_nft_compat_cb[NFNL_MSG_COMPAT_MAX] = { 759 [NFNL_MSG_COMPAT_GET] = { 760 .call = nfnl_compat_get_rcu, 761 .type = NFNL_CB_RCU, 762 .attr_count = NFTA_COMPAT_MAX, 763 .policy = nfnl_compat_policy_get 764 }, 765}; 766 767static const struct nfnetlink_subsystem nfnl_compat_subsys = { 768 .name = "nft-compat", 769 .subsys_id = NFNL_SUBSYS_NFT_COMPAT, 770 .cb_count = NFNL_MSG_COMPAT_MAX, 771 .cb = nfnl_nft_compat_cb, 772}; 773 774static struct nft_expr_type nft_match_type; 775 776static bool nft_match_reduce(struct nft_regs_track *track, 777 const struct nft_expr *expr) 778{ 779 const struct xt_match *match = expr->ops->data; 780 781 return strcmp(match->name, "comment") == 0; 782} 783 784static const struct nft_expr_ops * 785nft_match_select_ops(const struct nft_ctx *ctx, 786 const struct nlattr * const tb[]) 787{ 788 struct nft_expr_ops *ops; 789 struct xt_match *match; 790 unsigned int matchsize; 791 char *mt_name; 792 u32 rev, family; 793 int err; 794 795 if (tb[NFTA_MATCH_NAME] == NULL || 796 tb[NFTA_MATCH_REV] == NULL || 797 tb[NFTA_MATCH_INFO] == NULL) 798 return ERR_PTR(-EINVAL); 799 800 mt_name = nla_data(tb[NFTA_MATCH_NAME]); 801 rev = ntohl(nla_get_be32(tb[NFTA_MATCH_REV])); 802 family = ctx->family; 803 804 match = xt_request_find_match(family, mt_name, rev); 805 if (IS_ERR(match)) 806 return ERR_PTR(-ENOENT); 807 808 if (match->matchsize > nla_len(tb[NFTA_MATCH_INFO])) { 809 err = -EINVAL; 810 goto err; 811 } 812 813 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL); 814 if (!ops) { 815 err = -ENOMEM; 816 goto err; 817 } 818 819 ops->type = &nft_match_type; 820 ops->eval = nft_match_eval; 821 ops->init = nft_match_init; 822 ops->destroy = nft_match_destroy; 823 ops->dump = nft_match_dump; 824 ops->validate = nft_match_validate; 825 ops->data = match; 826 ops->reduce = nft_match_reduce; 827 828 matchsize = NFT_EXPR_SIZE(XT_ALIGN(match->matchsize)); 829 if (matchsize > NFT_MATCH_LARGE_THRESH) { 830 matchsize = NFT_EXPR_SIZE(sizeof(struct nft_xt_match_priv)); 831 832 ops->eval = nft_match_large_eval; 833 ops->init = nft_match_large_init; 834 ops->destroy = nft_match_large_destroy; 835 ops->dump = nft_match_large_dump; 836 } 837 838 ops->size = matchsize; 839 840 return ops; 841err: 842 module_put(match->me); 843 return ERR_PTR(err); 844} 845 846static void nft_match_release_ops(const struct nft_expr_ops *ops) 847{ 848 struct xt_match *match = ops->data; 849 850 module_put(match->me); 851 kfree(ops); 852} 853 854static struct nft_expr_type nft_match_type __read_mostly = { 855 .name = "match", 856 .select_ops = nft_match_select_ops, 857 .release_ops = nft_match_release_ops, 858 .policy = nft_match_policy, 859 .maxattr = NFTA_MATCH_MAX, 860 .owner = THIS_MODULE, 861}; 862 863static struct nft_expr_type nft_target_type; 864 865static const struct nft_expr_ops * 866nft_target_select_ops(const struct nft_ctx *ctx, 867 const struct nlattr * const tb[]) 868{ 869 struct nft_expr_ops *ops; 870 struct xt_target *target; 871 char *tg_name; 872 u32 rev, family; 873 int err; 874 875 if (tb[NFTA_TARGET_NAME] == NULL || 876 tb[NFTA_TARGET_REV] == NULL || 877 tb[NFTA_TARGET_INFO] == NULL) 878 return ERR_PTR(-EINVAL); 879 880 tg_name = nla_data(tb[NFTA_TARGET_NAME]); 881 rev = ntohl(nla_get_be32(tb[NFTA_TARGET_REV])); 882 family = ctx->family; 883 884 if (strcmp(tg_name, XT_ERROR_TARGET) == 0 || 885 strcmp(tg_name, XT_STANDARD_TARGET) == 0 || 886 strcmp(tg_name, "standard") == 0) 887 return ERR_PTR(-EINVAL); 888 889 target = xt_request_find_target(family, tg_name, rev); 890 if (IS_ERR(target)) 891 return ERR_PTR(-ENOENT); 892 893 if (!target->target) { 894 err = -EINVAL; 895 goto err; 896 } 897 898 if (target->targetsize > nla_len(tb[NFTA_TARGET_INFO])) { 899 err = -EINVAL; 900 goto err; 901 } 902 903 ops = kzalloc(sizeof(struct nft_expr_ops), GFP_KERNEL); 904 if (!ops) { 905 err = -ENOMEM; 906 goto err; 907 } 908 909 ops->type = &nft_target_type; 910 ops->size = NFT_EXPR_SIZE(XT_ALIGN(target->targetsize)); 911 ops->init = nft_target_init; 912 ops->destroy = nft_target_destroy; 913 ops->dump = nft_target_dump; 914 ops->validate = nft_target_validate; 915 ops->data = target; 916 ops->reduce = NFT_REDUCE_READONLY; 917 918 if (family == NFPROTO_BRIDGE) 919 ops->eval = nft_target_eval_bridge; 920 else 921 ops->eval = nft_target_eval_xt; 922 923 return ops; 924err: 925 module_put(target->me); 926 return ERR_PTR(err); 927} 928 929static void nft_target_release_ops(const struct nft_expr_ops *ops) 930{ 931 struct xt_target *target = ops->data; 932 933 module_put(target->me); 934 kfree(ops); 935} 936 937static struct nft_expr_type nft_target_type __read_mostly = { 938 .name = "target", 939 .select_ops = nft_target_select_ops, 940 .release_ops = nft_target_release_ops, 941 .policy = nft_target_policy, 942 .maxattr = NFTA_TARGET_MAX, 943 .owner = THIS_MODULE, 944}; 945 946static int __init nft_compat_module_init(void) 947{ 948 int ret; 949 950 ret = nft_register_expr(&nft_match_type); 951 if (ret < 0) 952 return ret; 953 954 ret = nft_register_expr(&nft_target_type); 955 if (ret < 0) 956 goto err_match; 957 958 ret = nfnetlink_subsys_register(&nfnl_compat_subsys); 959 if (ret < 0) { 960 pr_err("nft_compat: cannot register with nfnetlink.\n"); 961 goto err_target; 962 } 963 964 return ret; 965err_target: 966 nft_unregister_expr(&nft_target_type); 967err_match: 968 nft_unregister_expr(&nft_match_type); 969 return ret; 970} 971 972static void __exit nft_compat_module_exit(void) 973{ 974 nfnetlink_subsys_unregister(&nfnl_compat_subsys); 975 nft_unregister_expr(&nft_target_type); 976 nft_unregister_expr(&nft_match_type); 977} 978 979MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_NFT_COMPAT); 980 981module_init(nft_compat_module_init); 982module_exit(nft_compat_module_exit); 983 984MODULE_LICENSE("GPL"); 985MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); 986MODULE_ALIAS_NFT_EXPR("match"); 987MODULE_ALIAS_NFT_EXPR("target"); 988MODULE_DESCRIPTION("x_tables over nftables support"); 989